Journal articles on the topic 'Surface measurable features'
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1
Podgorny, Igor, Dan Lubin, and Donald K. Perovich. "Monte Carlo Study of UAV-Measurable Albedo over Arctic Sea Ice." Journal of Atmospheric and Oceanic Technology 35, no. 1 (January 2018): 57–66. http://dx.doi.org/10.1175/jtech-d-17-0066.1.
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AbstractIn anticipation that unmanned aerial vehicles (UAVs) will have a useful role in atmospheric energy budget studies over sea ice, a Monte Carlo model is used to investigate three-dimensional radiative transfer over a highly inhomogeneous surface albedo involving open water, sea ice, and melt ponds. The model simulates the spatial variability in 550-nm downwelling irradiance and albedo that a UAV would measure above this surface and underneath an optically thick, horizontally homogeneous cloud. At flight altitudes higher than 100 m above the surface, an airborne radiometer will sample irradiances that are greatly smoothed horizontally as a result of photon multiple reflection. If one is interested in sampling the local energy budget contrasts between specific surface types, then the UAV must fly at a low altitude, typically within 20 m of the surface. Spatial upwelling irradiance variability in larger open water features, on the order of 1000 m wide, will remain apparent as high as 500 m above the surface. To fully investigate the impact of surface feature variability on the energy budget of the lower troposphere ice–ocean system, a UAV needs to fly at a variety of altitudes to determine how individual features contribute to the area-average albedo.
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Matt, S., A. Fujimura, A. Soloviev, S. H. Rhee, and R. Romeiser. "Fine-scale features on the sea surface in SAR satellite imagery – Part 2: Numerical modeling." Ocean Science 10, no. 3 (June 2, 2014): 427–38. http://dx.doi.org/10.5194/os-10-427-2014.
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Abstract. With the advent of the new generation of synthetic aperture radar (SAR) satellites, it has become possible to resolve fine-scale features on the sea surface on the scale of meters. The proper identification of sea surface signatures in SAR imagery can be challenging, since some features may be due to atmospheric distortions (gravity waves, squall lines) or anthropogenic influences (slicks), and may not be related to dynamic processes in the upper ocean. In order to improve our understanding of the nature of fine-scale features on the sea surface and their signature in SAR, we have conducted high-resolution numerical simulations combining a three-dimensional non-hydrostatic computational fluid dynamics model with a radar imaging model. The surface velocity field from the hydrodynamic model is used as input to the radar imaging model. The combined approach reproduces the sea surface signatures in SAR of ship wakes, low-density plumes, and internal waves in a stratified environment. The numerical results are consistent with observations reported in a companion paper on in situ measurements during SAR satellite overpasses. Ocean surface and internal waves are also known to produce a measurable signal in the ocean magnetic field. This paper explores the use of computational fluid dynamics to investigate the magnetic signatures of oceanic processes. This potentially provides a link between SAR signatures of transient ocean dynamics and magnetic field fluctuations in the ocean. We suggest that combining SAR imagery with data from ocean magnetometers may be useful as an additional maritime sensing method. The new approach presented in this work can be extended to other dynamic processes in the upper ocean, including fronts and eddies, and can be a valuable tool for the interpretation of SAR images of the ocean surface.
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Matt, S., A. Fujimura, A. Soloviev, S. H. Rhee, and R. Romeiser. "Fine-scale features on the sea surface in SAR satellite imagery – Part 2: Numerical modeling." Ocean Science Discussions 9, no. 5 (September 17, 2012): 2915–50. http://dx.doi.org/10.5194/osd-9-2915-2012.
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Abstract. With the advent of the new generation of SAR satellites, it has become possible to resolve fine-scale features on the sea surface on the scale of meters. The proper identification of sea surface signatures in SAR imagery can be challenging, since some features may be due to atmospheric distortions (gravity waves, squall lines) or anthropogenic influences (slicks), and may not be related to dynamic processes in the upper ocean. In order to improve our understanding of the nature of fine-scale features on the sea surface and their signature in SAR, we have conducted high-resolution numerical simulations combining a three-dimensional non-hydrostatic computational fluid dynamics model with a radar imaging model. The surface velocity field from the hydrodynamic model is used as input to the radar imaging model. The combined approach reproduces the sea surface signatures in SAR of ship wakes, low density plumes, and internal waves in a stratified environment. The numerical results are consistent with observations reported in a companion paper of in-situ measurements during SAR satellite overpasses. Ocean surface and internal waves are also known to produce a measurable signal in the ocean magnetic field. This paper explores the use of computational fluid dynamics to investigate the magnetic signatures of oceanic processes. This potentially provides a link between SAR signatures of transient ocean dynamics and magnetic field fluctuations in the ocean. We suggest that combining SAR imagery with data from ocean magnetometers may be useful as an additional maritime sensing method. The new approach presented in this work can be extended to other dynamic processes in the upper ocean, including fronts and eddies, and can be a valuable tool for the interpretation of SAR images of the ocean surface.
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Domino, Małgorzata, Marta Borowska, Anna Trojakowska, Natalia Kozłowska, Łukasz Zdrojkowski, Tomasz Jasiński, Graham Smyth, and Małgorzata Maśko. "The Effect of Rider:Horse Bodyweight Ratio on the Superficial Body Temperature of Horse’s Thoracolumbar Region Evaluated by Advanced Thermal Image Processing." Animals 12, no. 2 (January 13, 2022): 195. http://dx.doi.org/10.3390/ani12020195.
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Appropriate matching of rider–horse sizes is becoming an increasingly important issue of riding horses’ care, as the human population becomes heavier. Recently, infrared thermography (IRT) was considered to be effective in differing the effect of 10.6% and 21.3% of the rider:horse bodyweight ratio, but not 10.1% and 15.3%. As IRT images contain many pixels reflecting the complexity of the body’s surface, the pixel relations were assessed by image texture analysis using histogram statistics (HS), gray-level run-length matrix (GLRLM), and gray level co-occurrence matrix (GLCM) approaches. The study aimed to determine differences in texture features of thermal images under the impact of 10–12%, >12 ≤15%, >15 <18% rider:horse bodyweight ratios, respectively. Twelve horses were ridden by each of six riders assigned to light (L), moderate (M), and heavy (H) groups. Thermal images were taken pre- and post-standard exercise and underwent conventional and texture analysis. Texture analysis required image decomposition into red, green, and blue components. Among 372 returned features, 95 HS features, 48 GLRLM features, and 96 GLCH features differed dependent on exercise; whereas 29 HS features, 16 GLRLM features, and 30 GLCH features differed dependent on bodyweight ratio. Contrary to conventional thermal features, the texture heterogeneity measures, InvDefMom, SumEntrp, Entropy, DifVarnc, and DifEntrp, expressed consistent measurable differences when the red component was considered.
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Bechtel, S. E., M. G. Forest, N. T. Youssef, and H. Zhou. "The Effect of Dynamic Surface Tension on the Oscillation of Slender Elliptical Newtonian Jets." Journal of Applied Mechanics 65, no. 3 (September 1, 1998): 694–704. http://dx.doi.org/10.1115/1.2789113.
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We investigate free-surface oscillating jets with elliptical cross section, focusing on behavior associated with decaying surface tension. Previous one-dimensional equations for an oscillating jet are extended to allow variable surface tension on short space and time scales relevant for surfactant mixtures. We presume the decay of surface tension as a function of surface age, and derive the resulting jet behavior. Three plausible forms of decay are studied: an exponential decay, a diffusion model derived in Brazee et al. (1994), and an algebraic form due to Hua and Rosen (1991). Our simulations suggest both experimental regimes, and measurable jet features in these regimes, which may be exploited in an inverse formulation to deduce the unknown rapid surface tension decay of a given surfactant mixture. In particular, we establish numerical relationships between the amplitude and the wavelength of either a sustained far-field oscillation or oscillation at a fixed downstream location and the entire history of surface tension decay. These numerical relationships are ideal for the inverse formulation, in that the complete surface tension evolution may be deduced solely from far-field or downstream jet measurements, away from the confined part of the jet where the surface tension is rapidly changing.
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Berzaghi, Rodrigo, Muhammad Asad Ahktar, Ashraful Islam, Brede D. Pedersen, Turid Hellevik, and Inigo Martinez-Zubiaurre. "Fibroblast-Mediated Immunoregulation of Macrophage Function Is Maintained after Irradiation." Cancers 11, no. 5 (May 17, 2019): 689. http://dx.doi.org/10.3390/cancers11050689.
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The abilities of cancer-associated fibroblasts (CAFs) to regulate immune responses in the context of radiotherapy remain largely unknown. This study was undertaken to determine whether ionizing radiation alters the CAF-mediated immunoregulatory effects on macrophages. CAFs were isolated from freshly-resected non-small cell lung cancer tumors, while monocyte-derived macrophages were prepared from peripheral blood of healthy donors. Experimental settings included both (CAF-macrophage) co-cultures and incubations of M0 and M1-macrophages in the presence of CAF-conditioned medium (CAF-CM). Functional assays to study macrophage polarization/activation included the expression of cell surface markers, production of nitric oxide, secretion of inflammatory cytokines and migratory capacity. We show that CAFs promote changes in M0-macrophages that harmonize with both M1-and M2-phenotypes. Additionally, CAFs inhibit pro-inflammatory features of M1-macrophages by reducing nitric oxide production, pro-inflammatory cytokines, migration, and M1-surface markers expression. Radiation delivered as single-high dose or in fractioned regimens did not modify the immunoregulatory features exerted by CAFs over macrophages in vitro. Protein expression analyses of CAF supernatants showed that irradiated and non-irradiated CAFs produce approximately the same protein levels of immunoregulators. Thus, CAF-derived soluble factors mediate measurable changes on uncommitted macrophages and down-regulate pro-inflammatory features of M1-polarized macrophages. Notably, ionizing radiation does not curtail the CAF-mediated immunosuppressive effects.
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Rutherford, A. C., D. J. Inman, G. Park, and F. M. Hemez. "Use of Response Surface Metamodels for Identification of Stiffness and Damping Coefficients in a Simple Dynamic System." Shock and Vibration 12, no. 5 (2005): 317–31. http://dx.doi.org/10.1155/2005/484283.
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Metamodels have been used with success in many areas of engineering for decades but only recently in the field of structural dynamics. A metamodel is a fast running surrogate that is typically used to aid an analyst or test engineer in the fast and efficient exploration of the design space. Response surface metamodels are used in this work to perform parameter identification of a simple five degree of freedom system, motivated by their low training requirements and ease of use. In structural dynamics applications, response surface metamodels have been utilized in a forward sense, for activities such as sensitivity analysis or uncertainty quantification. In this study a polynomial response surface model is developed, relating system parameters to measurable output features. Once this relationship is established, the response surface is used in an inverse sense to identify system parameters from measured output features.A design of experiments is utilized to choose points, representing a fraction of the full design space of interest, for fitting the response surface metamodel. Two parameters commonly used to characterize damage in a structural system, stiffness and damping, are identified. First changes are identified and located with success in a linear 5DOF system. Then parameter identification is attempted with a nonlinear 5DOF system and limited success is achieved. This work will demonstrate that use of response surface metamodels in an inverse sense shows promise for use in system parameter identification for both linear and weakly nonlinear systems and that the method has potential for use in damage identification applications.
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Jerison, Harry J. "Digitized Fossil Brains: Neocorticalization." Biolinguistics 6, no. 3-4 (November 28, 2012): 383–92. http://dx.doi.org/10.5964/bioling.8929.
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This report is based on 3D digital scans of endocasts of 110 species of fossil mammals and 35 species of living mammals. It presents direct evidence of the last 60 million years of brain evolution. Endocasts are casts of the cranial cavity. They are brainlike in size and shape, and their surface features can be named as if they were brain structures. Although endocast data are restricted to outer surfaces of brains, a few inferences about inner structure are possible. Neocortex in the forebrain, for example, is identifiable and measurable as cerebral forebrain on the endocast dorsal to the rhinal fissure. An important result in this report is that surface area of neocortex as identified on endocasts appears to have reached a maximum of about 80% of the total endocast surface area in anthropoid primates including humans. This may be a fundamental limitation in brain size. The average neocorticalization percentage for mammals as a whole rose from about 20% to about 50% of the surface area during the 60 million years covered by this analysis. Neocorticalization is associated with the evolution of higher mental processes, including the evolution of language as a hominin specialization. The limitation of the increase in relative amount of neocortex is similar in all anthropoids. Neocortex is greater in absolute area in living humans because the total size of the hominin brain is so much larger than in other primates.
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Hurst, Martin D., Simon M. Mudd, Mikael Attal, and George Hilley. "Hillslopes Record the Growth and Decay of Landscapes." Science 341, no. 6148 (August 22, 2013): 868–71. http://dx.doi.org/10.1126/science.1241791.
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Earth's surface archives the combined history of tectonics and erosion, which tend to roughen landscapes, and sediment transport and deposition, which smooth them. We analyzed hillslope morphology in the tectonically active Dragon’s Back Pressure Ridge in California, United States, to assess whether tectonic uplift history can be reconstructed using measurable attributes of hillslope features within landscapes. Hilltop curvature and hillslope relief mirror measured rates of vertical displacement caused by tectonic forcing, and their relationships are consistent with those expected when idealizing hillslope transport as a nonlinear diffusion process. Hilltop curvature lags behind relief in its response to changing erosion rates, allowing growing landscapes to be distinguished from decaying landscapes. Numerical modeling demonstrates that hillslope morphology may be used to infer changes in tectonic rates.
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Huang, Zhiwen, Jianmin Zhu, Jingtao Lei, Xiaoru Li, and Fengqing Tian. "Tool Wear Monitoring with Vibration Signals Based on Short-Time Fourier Transform and Deep Convolutional Neural Network in Milling." Mathematical Problems in Engineering 2021 (June 30, 2021): 1–14. http://dx.doi.org/10.1155/2021/9976939.
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Tool wear monitoring is essential in precision manufacturing to improve surface quality, increase machining efficiency, and reduce manufacturing cost. Although tool wear can be reflected by measurable signals in automatic machining operations, with the increase of collected data, features are manually extracted and optimized, which lowers monitoring efficiency and increases prediction error. For addressing the aforementioned problems, this paper proposes a tool wear monitoring method using vibration signal based on short-time Fourier transform (STFT) and deep convolutional neural network (DCNN) in milling operations. First, the image representation of acquired vibration signals is obtained based on STFT, and then the DCNN model is designed to establish the relationship between obtained time-frequency maps and tool wear, which performs adaptive feature extraction and automatic tool wear prediction. Moreover, this method is demonstrated by employing three tool wear experimental datasets collected from three-flute ball nose tungsten carbide cutter of a high-speed CNC machine under dry milling. Finally, the experimental results prove that the proposed method is more accurate and relatively reliable than other compared methods.
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Wakefield, Ewan D., Richard A. Phillips, and Mark Belchier. "Foraging black-browed albatrosses target waters overlaying moraine banks - a consequence of upward benthic-pelagic coupling?" Antarctic Science 24, no. 3 (March 6, 2012): 269–80. http://dx.doi.org/10.1017/s0954102012000132.
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AbstractWide-ranging, surface-feeding pelagic seabirds are the most numerous functional group of birds in the Southern Ocean. The mesoscale habitat use of these birds is increasingly being quantified by relating their movements to remotely sensed, near surface properties of the ocean. However, prey availability at the sea surface may also be determined by habitat characteristics not measurable from space. For instance, benthic-pelagic coupling, which occurs when seabed processes affect productivity in the epipelagic zone, can link benthic habitat type to availability of surface prey. We combined acoustically derived maps of the substrate of the South Georgia shelf with GPS tracking to quantify the sub-mesoscale habitat use of breeding black-browed albatrosses. We show that albatrosses preferentially used waters overlaying glacial moraine banks near the shelf edge and that this was unrelated to the presence of trawlers targeting mackerel icefish, which are also associated with these features. Stomach temperature profiles suggest that albatrosses primarily caught krill and fish over the banks. We hypothesize that black-browed albatrosses target waters overlaying moraine banks due to upward benthic-pelagic coupling, mediated by an increase in abundance of zooplankton such as Antarctic krill. Our findings suggest that the potential effects of such processes on pelagic seabird distribution warrant wider investigation.
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Kurtev, R. G., V. D. Ivanov, R. Jayawardhana, and J. H. Borissova. "Ultra cool dwarfs with companions." Proceedings of the International Astronomical Union 5, H15 (November 2009): 546. http://dx.doi.org/10.1017/s1743921310010653.
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The binary fraction in the sub-stellar regime is a topic of discussion. The lower masses of ultra cool dwarfs (UCDs) with respect to the other stars make them even more important because a measurable effect on their radial velocity (RV) or luminosities can be caused by extremely low mass companions. Some UCDs in young star forming regions are bright enough to be studied with existing high resolution instrumentation. The UCDs are intrinsically faint in the optical and the optical RV measurements are affected by “rotationally modulated inhomogeneous surface features” that can mimic a companion, while the near-infrared (NIR) RVs are less prone to them. Therefore, we decided to monitor the RV of six UCDs in the NIR. Blake et al. (2007) demonstrated RV measurement accuracy of 300-600 m s−1 in the NIR using telluric calibration.
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Kolachalama, Srikanth, and Hafiz Malik. "A NARX Model to Predict Cabin Air Temperature to Ameliorate HVAC Functionality." Vehicles 3, no. 4 (December 3, 2021): 872–89. http://dx.doi.org/10.3390/vehicles3040052.
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Vehicular technology has integrated many features in the system, which enhances the safety and comfort of the user. Among these features, heating, ventilation, and air conditioning (HVAC) is the only feature that maintains the set cabin air temperature (CAT). The user’s command drives the set CAT, and the thermostat provides feedback to the HVAC to maintain the set CAT. The CAT is increased by extracting the heat from the engine surface produced by the fuel combustion, whereas the CAT is reduced by the known processes of the air conditioning system (ACS). Therefore, the CAT driven by the user’s command may not be optimal, and estimating the optimal CAT is still unsolved. In this work, we propose a new process where the user can input a range for CAT instead of a single value. Optimal HVAC criteria were defined, and the CAT was estimated by performing iterative analysis in the user-selected range satisfying the criteria. The HVAC criteria were defined based on two measurable parameters: air conditioning refrigerant fluid pressure (ACRFP) and engine surface temperature (EST) empirically defined as the vector CATOP. In this article, a NARX DL model was used by mapping the vehicle-level vectors (VLV) to predict the CATOP in real-time using field data obtained from a 2020 Cadillac CT5 test vehicle. Utilising the DL model, CATOP for future time steps was predicted by varying the CAT in the definite range and applying HVAC criteria. Thus, an optimal set CAT was estimated, corresponding to the optimal CATOP defined by the HVAC criteria. We performed the validation of the DL model for multiple datasets using traditional statistical techniques, namely, signal-to-noise ratio (SNR) values, first-order derivatives (FOD), and root-mean-square error (RMSE).
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Weiss, W. W., H. E. Fröhlich, T. Kallinger, R. Kuschnig, A. Popowicz, D. Baade, D. Buzasi, et al. "New BRITE-Constellation observations of the roAp star α Cir." Astronomy & Astrophysics 642 (October 2020): A64. http://dx.doi.org/10.1051/0004-6361/202038345.
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Context. Chemically peculiar (CP) stars with a measurable magnetic field comprise the group of mCP stars. The pulsating members define the subgroup of rapidly oscillating Ap (roAp) stars, of which α Cir is the brightest member. Hence, α Cir allows the application of challenging techniques, such as interferometry, very high temporal and spectral resolution photometry, and spectroscopy in a wide wavelength range, that have the potential to provide unique information about the structure and evolution of a star. Aims. Based on new photometry from BRITE-Constellation, obtained with blue and red filters, and on photometry from WIRE, SMEI, and TESS we attempt to determine the surface spot structure of α Cir and investigate pulsation frequencies. Methods. We used photometric surface imaging and frequency analyses and Bayesian techniques in order to quantitatively compare the probability of different models. Results. BRITE-Constellation photometry obtained from 2014 to 2016 is put in the context of space photometry obtained by WIRE, SMEI, and TESS. This provides improvements in the determination of the rotation period and surface features (three spots detected and a fourth one indicated). The main pulsation frequencies indicate two consecutive radial modes and one intermediate dipolar mode. Advantages and problems of the applied Bayesian technique are discussed.
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Yin, Qing, Jörg Kolbe, Marco Haupt, and A. Erman Tekkaya. "Achieving High Strains in Sheet Metal Characterization Using the In-Plane Torsion Test." Key Engineering Materials 554-557 (June 2013): 77–85. http://dx.doi.org/10.4028/www.scientific.net/kem.554-557.77.
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The in-plane torsion test is used to determine plastic flow curves for sheet metals. Very high strains of up to an equivalent strain of 1.0 can be measured since there are no edge effects in a plane torsion specimen. In combination with optical strain measurement, an efficient evaluation method for this test was developed. However, the achievable strain varies for each material. The slippage between the inner clamps and the specimen was found to be one main limiting effect. In order to improve the clamping capability, different surface corrugations are applied at the inner clamping tool. Four sheet materials, DC06, DP600, AA6016, and AA5182 are selected for testing this new clamping setup. While the flow curve of DC06 is determined until a strain of 1.0 and above, such high values cannot be achieved for the other materials. It can be shown that the measurable strain can be increased by the choice of the surface corrugation features at the inner clamping. For the DP steel and the aluminum alloys, the flow curve can be determined until equivalent plastic strains of 0.5 to 0.6, which is also a significant improvement compared to many other sheet metal testing methods.
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Zhang, Wen Zheng, and Zhang Zhi Shi. "Description of Crystallographic Morphologies of Product Phases with Singularity and Δg Distribution." Solid State Phenomena 172-174 (June 2011): 1096–105. http://dx.doi.org/10.4028/www.scientific.net/ssp.172-174.1096.
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Product phases from various phase transformations often exhibit fascinating morphologies. Facets of unique crystallographic orientations are characteristic of the morphologies. Based on a comparison of facets in the surfaces and interfaces of crystals, this paper proposes to use singularity as the common features of facets on a crystal. While association of facets with energy singularity has been established from the Wulff construction, we defined singularity in structure with an absence of one or more types of defects common to a vicinal surface or interface. Singularity in an interfacial structure is described in terms of both ledges and dislocations. When dislocations are involved, the candidates of the singular interfaces derive mainly from the principal O-lattice planes. The orientations of these planes are defined by Δg’s, which are measurable in diffraction patterns. Singularity with respect to the orientation relationship results from further eliminating defects, which is permitted by a special arrangement of Δg’s. The candidates of singular interface confined by the arrangement of discrete Δg’s are helpful for understanding the crystallographic morphology. One example from an Mg alloy is provided to show the association of the singular interfaces with Δg’s. The effect of the potential presence of a long-range strain and kinetic effects are briefly discussed.
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Herman, Frédéric, Brian Anderson, and Sébastien Leprince. "Mountain glacier velocity variation during a retreat/advance cycle quantified using sub-pixel analysis of ASTER images." Journal of Glaciology 57, no. 202 (2011): 197–207. http://dx.doi.org/10.3189/002214311796405942.
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AbstractCoverage of ice velocities in the central part of the Southern Alps, New Zealand, is obtained from feature tracking using repeat optical imagery in 2002 and 2006. Precise orthorectification, co-registration and correlation is carried out using the freely available software COSI-Corr. This analysis, combined with short times between image acquisitions, has enabled velocities to be captured even in the accumulation areas, where velocities are lowest and surface features ephemeral. The results indicate large velocities for mountain glaciers (i.e. up to ∼5 m d−1) as well as dynamic changes in some glaciers that have occurred between 2002 and 2006. For the steep and more responsive Fox and Franz Josef Glaciers the speed increased at the glacier snout during the advance period, while the low-angled and debris-covered Tasman Glacier showed no measurable velocity change. Velocity increases on the steeper glaciers are the result of an observed thickening and steepening of the glacier tongues as they moved from a retreat phase in 2002 to an advance phase in 2006. This contrasting behaviour is consistent with historic terminus position changes. The steeper glaciers have undergone several advance/retreat cycles during the observation period (1894 to present), while the low-angled glacier showed little terminus response until retreat resulting from the accelerating growth of a proglacial lake commenced in 1983.
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Alley, Richard B. "Concerning the Deposition and Diagenesis of Strata in Polar Firn." Journal of Glaciology 34, no. 118 (1988): 283–90. http://dx.doi.org/10.1017/s0022143000007024.
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Abstract Depth hoar in polar firn forms when large temperature gradients act on low-density firn, but high-density firn does not develop into depth hoar. Low densities in firn may be depositional (burial of surface hoar or still-air snowfall) or diagenetic (mass loss to the free atmosphere, typically in autumn); however, diagenesis is sufficiently strong to cause significant mass loss only in the top 50–100 mm of firn. Between about 50–100 mm and 2 m depth, grain growth and densification are accelerated strongly by temperature-gradient effects; from 2 to 5 m, temperature gradients have a small but measurable effect on rates of processes in firn, and below 5 m rates essentially have isothermal values. Diagenetic depth-hoar layers typically develop in the autumn, are relatively thick, and have smooth bases. Depositional depth-hoar layers may develop at any season, are relatively thin, and have irregular bases. In low-accumulation regions, visual stratification may preserve only an annual signal, but in high-accumulation regions individual storms or other features may be recognizable.
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Alley, Richard B. "Concerning the Deposition and Diagenesis of Strata in Polar Firn." Journal of Glaciology 34, no. 118 (1988): 283–90. http://dx.doi.org/10.3189/s0022143000007024.
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AbstractDepth hoar in polar firn forms when large temperature gradients act on low-density firn, but high-density firn does not develop into depth hoar. Low densities in firn may be depositional (burial of surface hoar or still-air snowfall) or diagenetic (mass loss to the free atmosphere, typically in autumn); however, diagenesis is sufficiently strong to cause significant mass loss only in the top 50–100 mm of firn. Between about 50–100 mm and 2 m depth, grain growth and densification are accelerated strongly by temperature-gradient effects; from 2 to 5 m, temperature gradients have a small but measurable effect on rates of processes in firn, and below 5 m rates essentially have isothermal values.Diagenetic depth-hoar layers typically develop in the autumn, are relatively thick, and have smooth bases. Depositional depth-hoar layers may develop at any season, are relatively thin, and have irregular bases. In low-accumulation regions, visual stratification may preserve only an annual signal, but in high-accumulation regions individual storms or other features may be recognizable.
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Malinowski, Pawel, Tomasz Wandowski, and Wieslaw Ostachowicz. "Guided Waves for Aircraft Panel Monitoring." Key Engineering Materials 558 (June 2013): 107–15. http://dx.doi.org/10.4028/www.scientific.net/kem.558.107.
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The reported research concerns experimental investigation toward the monitoring of an aircraft panel. Guided wave propagation phenomena were used to obtain information about the state of the monitored structure. A curved aluminium panel with rivets was investigated. Piezoelectric transducer was used to excite guided waves in chosen structural element. The generated signal was amplified before applying it to the transducer in order to ensure measurable amplitude of excited guided waves. Measurement of the wave field was realized using laser scanning vibrometer that registered the velocity responses at a points belonging to a defined mesh. This contactless measurement technique allowed to investigate phenomena related to wave propagation in the aircraft panel. In the first stage, due to high complexity of the element, baseline measurements were taken. Next, a discontinuity (additional mass) was introduced on the panel surface and the measurements were repeated. Signal processing methods for features extraction from signals were proposed. These features were applied in order to detect and localize the presence anomalies in the investigated panel. The signal processing was conducted in MATLAB with the procedures developed by the authors. The used measurement technology (vibrometer) allowed to register whole wavefield of the propagating guided waves. This allowed to visualize the interaction of the waves with rivets. After introducing the discontinuity on the panel surface wave interaction with it was investigated. Two positions of the additional mass were considered. One just before the riveted stiffener and second after the stiffener. Because of this the influence of the stiffener on the damage detection abilities could be investigated. It can be concluded that the guided wave can be used for monitoring of such complex structures. The vibrometer measurements allowed learn about the guided wave propagation phenomena and perform successful damage localization.
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Holbrook, Sally J., Andrew J. Brooks, and Russell J. Schmitt. "Variation in structural attributes of patch-forming corals and in patterns of abundance of associated fishes." Marine and Freshwater Research 53, no. 7 (2002): 1045. http://dx.doi.org/10.1071/mf02063.
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There is increasing evidence that some of the spatial variation in characteristics of local assemblages of reef fish can be explained by variation in measurable features of the habitat. At Moorea, French Polynesia, several species of the coral genus Porites form patch reefs and provide an important source of habitat structure within the lagoons. One species, Porites rus, forms structurally complex patch reefs with surface branches and numerous holes and interior cavities. In contrast, reefs composed of colonies of Porites lobata-like species are less complex; they always lack branches and interior cavities and frequently lack holes. Surveys of these reefs revealed that, as expected, abundance and species richness of fish scaled with the size of the patch reef. However, for a given size, P. rus reefs had significantly higher species richness and overall abundance than P. lobata reefs. Further, abundances of fish, at the family level, varied among sets of reefs that had different combinations of key shelter microhabitats (i.e. holes, cavities, branches). This variation in relative abundances of fish families was predictable based on the microhabitat-use patterns of the fish; the greater the utilization of a microhabitat when available, the greater the difference in abundance between those reefs and others that lacked that microhabitat. Thus, spatial variation in the structure of the fish assemblages was strongly associated with variation among the types of patch-forming corals in the variety of microhabitat features each provided.
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Gjønnes, J., N. Bøe, and K. Gjønnes. "Structure Information From Electron Diffraction Intensities." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 2 (August 12, 1990): 516–17. http://dx.doi.org/10.1017/s0424820100136180.
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Structure information of high precision can be extracted from intentsity details in convergent beam patterns like the one reproduced in Fig 1. From low order reflections for small unit cell crystals,bonding charges, ionicities and atomic parameters can be derived, (Zuo, Spence and O’Keefe, 1988; Zuo, Spence and Høier 1989; Gjønnes, Matsuhata and Taftø, 1989) , but extension to larger unit cell ma seem difficult. The disks must then be reduced in order to avoid overlap calculations will become more complex and intensity features often less distinct Several avenues may be then explored: increased computational effort in order to handle the necessary many-parameter dynamical calculations; use of zone axis intensities at symmetry positions within the CBED disks, as in Figure 2 measurement of integrated intensity across K-line segments. In the last case measurable quantities which are well defined also from a theoretical viewpoint can be related to a two-beam like expression for the intensity profile:With as an effective Fourier potential equated to a gap at the dispersion surface, this intensity can be integrated across the line, with kinematical and dynamical limits proportional to and at low and high thickness respctively (Blackman, 1939).
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Fox, Peter A., and Sabatino Sofia. "Convection and Irradiance Variations." International Astronomical Union Colloquium 143 (1994): 280–90. http://dx.doi.org/10.1017/s0252921100024787.
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In the outer layers of the Sun (≈ 30% by radius), energy is transported by convection. The nature of the highly stratified and compressible convective flow is determined from the components of the energy flux (internal, kinetic, viscous, magnetic and radiative). Local suppressions or enhancements of any of these components may give rise to measurable changes in the emergent radiation.On the solar surface there is direct evidence for modulation of the emerging heat flux covering a large range in spatial and temporal scales, particularly associated with concentrated magnetic fields (e.g. sunspots, plages). Associated with these surface features is the observation that the characteristics of convective motions are also modified. In the deeper layers, the interaction of convection and magnetic fields will play an important role in readjusting the local emerging heat flux and thus should contribute to the modulation of the total solar irradiance.The task of calculating the response of the convection zone structure to developing active regions, and the solar activity cycle in general is difficult and complex due to the highly non-linear nature of the interaction of convection and magnetic fields. Theoretical work has ranged from empirical and global structure models, all the way to fine scale compressible convection simulations. This paper will highlight some recent theoretical advances that may have a direct bearing on the understanding of solar luminosity and irradiance variations and outline the important problems that must be addressed and what observational constraints may be used.
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Pesacreta, Thomas C., Leslie H. Groom, and Timothy G. Rials. "Atomic Force Microscopy of the Intervessel Pit Membrane in the Stem of Sapium Sebiferum (Euphorbiaceae)." IAWA Journal 26, no. 4 (2005): 397–426. http://dx.doi.org/10.1163/22941932-90000124.
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Sapwood and juvenile wood of Sapium sebiferum (Euphorbiaceae) was collected during 2000 –2002. In air-dried vessel elements, the surface of pit membranes (PMs) in the outermost growth ring was coated with plaque-like or interstitial material that was 2–5 nm thick. This coating was phase dark and overlaid a phase bright layer of globules and reticulately arranged microfibrils (MFs) that was 25–50 nm thick. Beneath the reticulate layer there was another surface exposed during sectioning/fracturing. It had parallel MFs which appeared to be continuous with the middle lamella, and were also coated. The total thickness of the dried PM appeared to be in the range of 50–100 nm. Overwintering and heartwood PMs were encrusted with a non-microfibrillar layer that differed from the above mentioned coating. Prior to chemical treatment, specific dried, untreated PMs were located and then the sample was dismounted, treated with acidic H2O2, and observed after treatment so that before and after images could be compared. Treatment with acidic H2O2 removed some of the coating and greatly modified the fibrillar nature of the surface layer, but did not reduce its overall thickness. The native structure of sapwood PMs was observed in water. Non-dried PMs displayed two layers, each with a different type of surface. The outer layer was non-microfibrillar and covered the entire surface of the PM. The non-microfibrillar layer was extremely sensitive to mechanical perturbation by the AFM tip, and had phase characteristics similar to the coating of dried PMs. The underlying layer was thick and microfibrillar. The MFs in non-dried PMs were, like the dried MFs, phase bright but they were much more loosely intermeshed compared with those seen in dried materials. The measurable thickness (which does not represent the total thickness) of non-dried PMs frequently ranged from 90–225 nm, although a few 500 nm vertical features were measured.
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Kanevsky, Nataly, and Nathan Dascal. "Regulation of Maximal Open Probability Is a Separable Function of Cavβ Subunit in L-type Ca2+ Channel, Dependent on NH2 Terminus of α1C (Cav1.2α)." Journal of General Physiology 128, no. 1 (June 26, 2006): 15–36. http://dx.doi.org/10.1085/jgp.200609485.
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β subunits (Cavβ) increase macroscopic currents of voltage-dependent Ca2+ channels (VDCC) by increasing surface expression and modulating their gating, causing a leftward shift in conductance–voltage (G-V) curve and increasing the maximal open probability, Po,max. In L-type Cav1.2 channels, the Cavβ-induced increase in macroscopic current crucially depends on the initial segment of the cytosolic NH2 terminus (NT) of the Cav1.2α (α1C) subunit. This segment, which we term the “NT inhibitory (NTI) module,” potently inhibits long-NT (cardiac) isoform of α1C that features an initial segment of 46 amino acid residues (aa); removal of NTI module greatly increases macroscopic currents. It is not known whether an NTI module exists in the short-NT (smooth muscle/brain type) α1C isoform with a 16-aa initial segment. We addressed this question, and the molecular mechanism of NTI module action, by expressing subunits of Cav1.2 in Xenopus oocytes. NT deletions and chimeras identified aa 1–20 of the long-NT as necessary and sufficient to perform NTI module functions. Coexpression of β2b subunit reproducibly modulated function and surface expression of α1C, despite the presence of measurable amounts of an endogenous Cavβ in Xenopus oocytes. Coexpressed β2b increased surface expression of α1C approximately twofold (as demonstrated by two independent immunohistochemical methods), shifted the G-V curve by ∼14 mV, and increased Po,max 2.8–3.8-fold. Neither the surface expression of the channel without Cavβ nor β2b-induced increase in surface expression or the shift in G-V curve depended on the presence of the NTI module. In contrast, the increase in Po,max was completely absent in the short-NT isoform and in mutants of long-NT α1C lacking the NTI module. We conclude that regulation of Po,max is a discrete, separable function of Cavβ. In Cav1.2, this action of Cavβ depends on NT of α1C and is α1C isoform specific.
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Concli, Franco, Ludovico Pierri, and Claudio Sbarufatti. "A Model-Based SHM Strategy for Gears—Development of a Hybrid FEM-Analytical Approach to Investigate the Effects of Surface Fatigue on the Vibrational Spectra of a Back-to-Back Test Rig." Applied Sciences 11, no. 5 (February 25, 2021): 2026. http://dx.doi.org/10.3390/app11052026.
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Transmissions are extensively employed in mechanical gearboxes when power conversion is required. Being able to provide specific maintenance is a crucial factor for both economics and reliability. However, although periodic transmission maintenance increases the systems’ longevity, it cannot prevent or predict sporadic major failures. In this context, structural health monitoring (SHM) represents a possible solution. Identifying variations of a specific measurable signal and correlating them with the type of damage or its location and severity may help assess the component condition and establish the need for maintenance operation. However, the collection of sufficient experimental examples for damage identification may be not convenient for big gearboxes, for which destructive experiments are too expensive, thus paving the way to model-based approaches, based on a numerical estimation of damage-related features. In this work, an SHM approach was developed based on signals from numerical simulations. To validate the approach with experimental measurements, a back-to-back test rig was used as a reference. Several types and severities of damages were simulated with an innovative hybrid analytical–numerical approach that allowed a significant reduction of the computational effort. The vibrational spectra that characterized the different damage conditions were processed through artificial neural networks (ANN) trained with numerical data and used to predict the presence, location, and severity of the damage.
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Matias, Kleber, Ana Dulce Freire, Carolina Matias, Maria Amélia Neves, and Cintia Machado. "CD38 Expression in B-Cell Chronic Lymphocytic Leukemia: Association with Clinical Presentation and Laboratory Features in 64 Newly Diagnosed Patients." Blood 106, no. 11 (November 16, 2005): 4492. http://dx.doi.org/10.1182/blood.v106.11.4492.4492.
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Abstract Background: B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the progressive accumulation of a neoplastic clone consisting of CD5/CD19/CD23/surface immunoglobulin cells. Despite this homogeneity in phenotype, B-CLL can follow either an indolent or a progressive course. CD38 is a transmembrane glycoprotein expressed on the surface of leukemic cells in a significant percentage of patients with B-CLL. Recent studies suggest that CD38 expression in CLL is a reliable prognostic marker, leading to an unfavorable clinical course with a more advanced stage of disease, poor responsiveness to chemotherapy and a shorter survival rate, along with others markers like ZAP-70 that reflect more accurately the mutagenic status of VH gene region, unfortunately not yet available in clinical practice routinely. Objectives: To assess the association of CD38+ expression with clinical and laboratory parameters at diagnosis in patients with B-CLL. Patients and Methods: CD38 expression was analyzed in 64 unselected newly diagnosed B-CLL patients from January 2003 to May 2005 seen at the Hematology Center of Pernambuco-Brazil (HEMOPE). According to Damle et al. patients with 30% or more B cells expressing CD38 were considered positive(CD38+), and those with less than 30% were considered negative(CD38−). Various patient characteristics were studied including age, sex, Binet stage, hemoglobin, ß2 microglobulin and lactate dehydrogenase levels in the serum. Statistical differences between each group (CD38+ vs CD38−) were analyzed using χ2 tests for categorical variables and Student’s t-tests for continuous variables. Results: Thirty-six patients (56.25%) were CD38+ and 28 (43.75%) were CD38-. Their median age at diagnosis was 64 years (range, 39–83) and the male to female ratio was 1.46:1. There were no differences between age, sex, hemoglobin and ß2 microglobulin levels in the CD38+ and CD38- groups. ß2 microglobulin level, however, was not available for assessment in all patients. Lactate dehydrogenase level was significantly higher in the CD38+ group (p=0.007). It was observed a trend toward a higher Binet stage (B or C) in the CD38+ compared with CD38- group (63.4 vs. 36.6% respectively), although not statistically significant (p=0.09) possibly because of the small number of patients studied. Conclusion: CD38 expression was associated with a higher lactate dehydrogenase level and a tendency for more aggressive clinical stage. CD38 evaluation is a measurable biological parameter that is not as subjective as the evaluation of some clinical parameters and should be considered a stantard clinical test for newly diagnosed B-CLL patients.
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Gour, Chandra Prakash, Priyanka Dhurvey, and Nagaraju Shaik. "Optimization and Prediction of Concrete with Recycled Coarse Aggregate and Bone China Fine Aggregate Using Response Surface Methodology." Journal of Nanomaterials 2022 (October 7, 2022): 1–11. http://dx.doi.org/10.1155/2022/2264457.
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Construction recycled material is crucial for protecting natural resources and promoting sustainable human development in a rapidly industrializing world. Many administrations worldwide accepted that it is beneficial to use demolition waste in the concrete building industry to reduce manufacturing costs and minimize the use of virgin aggregates. However, control measures should be done as their mechanical properties are poorer than traditional aggregates. To overcome this problem, pozzolanic materials like bone chine can be incorporated, providing extra CSH gel, which improves mechanical strength. Therefore, this research is aimed at producing eco-friendly concrete, which can be used for medium-grade strength, using recycled construction waste (RCA) as coarse and bone china fine aggregate (BCA) as fine aggregate. Workability, density, compressive, split tensile, and flexural strength are used to compare the fresh and hardened properties of the concrete. Experimental and statistical research is employed in the current study to evaluate the impact of RCA and BCA on the performance of concrete. To simulate all measurable responses, including workability, density, compressive, flexural, and split strength, RSM (response surface methodology) was utilized. The CCD (Central Composite Design) approach in RSM was used to create and analyze mixes in an experiment. Based on the experiment’s results, mathematical models were designed and assessed using the analysis of variance test (ANOVA). The analysis of variance results demonstrated the statistical significance of each constructed model. Three-dimensional response surface plots created using established regression models were used to investigate the interaction between the respective variables and to optimize the mixing ratio. The results indicate that the optimum utilization of RCA is up to 40% and BCA up to 60% as coarse and fine aggregate replacement in concrete, respectively, which not only helps to reduce costs but also offers sustainability. Finally, it was concluded that the generated models might be employed by obtaining the maximum tested features of concrete to assure a quick mix design approach. To conduct the microstructure study, thin section techniques were used to observe a strong aggregate-matrix interaction.
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Chen, CS, and J. Hawiger. "Reactivity of synthetic peptide analogs of adhesive proteins in regard to the interaction of human endothelial cells with extracellular matrix." Blood 77, no. 10 (May 15, 1991): 2200–2206. http://dx.doi.org/10.1182/blood.v77.10.2200.2200.
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Abstract Vascular endothelial cells, providing a nonthrombogenic surface to the lumenal aspect of blood vessels, are anchored to matrix adhesion molecules in the subendothelium through their respective receptors belonging to a superfamily of integrins. We analyzed the reactivity of synthetic peptide analogs of adhesive proteins toward human umbilical vein endothelial cells (HUVEC), assaying their detachment from extracellular matrix and attachment to extracellular matrix components in vitro. Synthetic peptide analogs Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP), Arg-Gly-Asp-Val (RGDV), Arg-Gly-Asp-Ser (RGDS), and Arg-Gly-Asp-Phe (RGDF), which are analogous to “cell adhesion site” of fibronectin, vitronectin, von Willebrand factor, and alpha-chain of human fibrinogen, respectively, caused significant detachment of HUVEC from the extracellular matrix in vitro at the concentrations ranging from 0.5 to 1.5 mmol/L. They also interfered with attachment of HUVEC to surfaces coated with subendothelial extracellular matrix or its components. The synthetic peptide analog of HHLGGAKQAGDV, which is homologous to the gamma-chain of human fibrinogen sequence 400–411, did not cause any measurable effect on the integrity of HUVEC monolayers (detachment and attachment). “Hybrid” peptides bearing salient features of both sequences, ie, Ala-Lys-Gln-Arg-Gly-Asp-Phe (AKQRGDF) and Lys- Gln-Arg-Gly-Asp-Phe (KQRGDF), had an attenuated effect on the detachment of HUVEC from extracellular matrix. Thus, the integrity of the human endothelial cell monolayer anchored to the extracellular matrix, as measured in detachment and attachment assays, is disturbed by peptides containing RGD sequence whereas the synthetic peptide His- His-Leu-Gly-Gly-Ala-Lys-Gln-Ala-Gly-Asp-Val (HHLGGAKQAGDV) is nonreactive.
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Chen, CS, and J. Hawiger. "Reactivity of synthetic peptide analogs of adhesive proteins in regard to the interaction of human endothelial cells with extracellular matrix." Blood 77, no. 10 (May 15, 1991): 2200–2206. http://dx.doi.org/10.1182/blood.v77.10.2200.bloodjournal77102200.
Full textAbstract:
Vascular endothelial cells, providing a nonthrombogenic surface to the lumenal aspect of blood vessels, are anchored to matrix adhesion molecules in the subendothelium through their respective receptors belonging to a superfamily of integrins. We analyzed the reactivity of synthetic peptide analogs of adhesive proteins toward human umbilical vein endothelial cells (HUVEC), assaying their detachment from extracellular matrix and attachment to extracellular matrix components in vitro. Synthetic peptide analogs Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP), Arg-Gly-Asp-Val (RGDV), Arg-Gly-Asp-Ser (RGDS), and Arg-Gly-Asp-Phe (RGDF), which are analogous to “cell adhesion site” of fibronectin, vitronectin, von Willebrand factor, and alpha-chain of human fibrinogen, respectively, caused significant detachment of HUVEC from the extracellular matrix in vitro at the concentrations ranging from 0.5 to 1.5 mmol/L. They also interfered with attachment of HUVEC to surfaces coated with subendothelial extracellular matrix or its components. The synthetic peptide analog of HHLGGAKQAGDV, which is homologous to the gamma-chain of human fibrinogen sequence 400–411, did not cause any measurable effect on the integrity of HUVEC monolayers (detachment and attachment). “Hybrid” peptides bearing salient features of both sequences, ie, Ala-Lys-Gln-Arg-Gly-Asp-Phe (AKQRGDF) and Lys- Gln-Arg-Gly-Asp-Phe (KQRGDF), had an attenuated effect on the detachment of HUVEC from extracellular matrix. Thus, the integrity of the human endothelial cell monolayer anchored to the extracellular matrix, as measured in detachment and attachment assays, is disturbed by peptides containing RGD sequence whereas the synthetic peptide His- His-Leu-Gly-Gly-Ala-Lys-Gln-Ala-Gly-Asp-Val (HHLGGAKQAGDV) is nonreactive.
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Hörstmann, Cora, Eric J. Raes, Pier Luigi Buttigieg, Claire Lo Monaco, Uwe John, and Anya M. Waite. "Hydrographic fronts shape productivity, nitrogen fixation, and microbial community composition in the southern Indian Ocean and the Southern Ocean." Biogeosciences 18, no. 12 (June 22, 2021): 3733–49. http://dx.doi.org/10.5194/bg-18-3733-2021.
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Abstract. Biogeochemical cycling of carbon (C) and nitrogen (N) in the ocean depends on both the composition and activity of underlying biological communities and on abiotic factors. The Southern Ocean is encircled by a series of strong currents and fronts, providing a barrier to microbial dispersion into adjacent oligotrophic gyres. Our study region straddles the boundary between the nutrient-rich Southern Ocean and the adjacent oligotrophic gyre of the southern Indian Ocean, providing an ideal region to study changes in microbial productivity. Here, we measured the impact of C and N uptake on microbial community diversity, contextualized by hydrographic factors and local physico-chemical conditions across the Southern Ocean and southern Indian Ocean. We observed that contrasting physico-chemical characteristics led to unique microbial diversity patterns, with significant correlations between microbial alpha diversity and primary productivity (PP). However, we detected no link between specific PP (PP normalized by chlorophyll-a concentration) and microbial alpha and beta diversity. Prokaryotic alpha and beta diversity were correlated with biological N2 fixation, which is itself a prokaryotic process, and we detected measurable N2 fixation to 60∘ S. While regional water masses have distinct microbial genetic fingerprints in both the eukaryotic and prokaryotic fractions, PP and N2 fixation vary more gradually and regionally. This suggests that microbial phylogenetic diversity is more strongly bounded by physical oceanographic features, while microbial activity responds more to chemical factors. We conclude that concomitant assessments of microbial diversity and activity are central to understanding the dynamics and complex responses of microorganisms to a changing ocean environment.
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Battaglia, Alessandra, Alessia Piermattei, Alexia Buzzonetti, Tina Pasciuto, Nicole Zampetti, Marco Fossati, Giuseppe Angelico, et al. "PD-L1 Expression on Circulating Tumour-Derived Microvesicles as a Complementary Tool for Stratification of High-Grade Serous Ovarian Cancer Patients." Cancers 13, no. 20 (October 16, 2021): 5200. http://dx.doi.org/10.3390/cancers13205200.
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Background: Ovarian cancer (OC) has recently attracted attention for the use of PD-1/PD-L1 axis blocking agents, with durable activity reported only in a subset of patients. The most used biomarker for sensitivity to the PD-1/PD-L1 axis blockade is tumour PD-L1 status by immunohistochemistry. However, patient stratification using this method suffers from intrinsic heterogeneity of OC, likely contributing to the unsatisfactory results obtained so far. Cells communicate with each other by releasing microvesicles (MVs) that carry parental cell surface features. Thus, we hypothesised that PD-L1+ tumour cells (TC) and infiltrating PD-L1+ leukocytes should shed MVs carrying surface PD-L1 that may serve as a proxy for the whole tumour PD-L1 status. Results: We showed for the first time the presence of measurable amounts of TC- and leukocyte-derived PD-L1+ MVs (range: 1.4–178.8 MVs/μL and 6.2–504.8 MVs/μL, respectively) in the plasma of high-grade serous OC (HGSOC) patients (n = 63), using a sensitive flow cytometry platform. The concentration of PD-L1+ MVs of either origin did not associate with the PD-L1 status of TCs and leukocytes in the tumour biopsies, suggesting that the circulating PD-L1+ MVs also included ones from locations not selected for immunohistochemistry analysis and represented the PD-L1 status of the whole tumour mass. In this study, we also describe the serendipitous discovery of circulating PD-L1+ MVs of platelet origin (10.3–2409.6 MVs/μL). Conclusions: The enumeration of circulating PD-L1+ MVs in HGSOC patients may provide a novel direction for assessing the tumour PD-L1 status and contribute to HGSOC patient stratification for immunotherapy interventions. The presence of circulating PD-L1+ MVs of platelet origin, a finding not yet reported in HGSOC patients, warrants further studies.
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Weiss, Chester J. "Finite-element analysis for model parameters distributed on a hierarchy of geometric simplices." GEOPHYSICS 82, no. 4 (July 1, 2017): E155—E167. http://dx.doi.org/10.1190/geo2017-0058.1.
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A resurgence of interest in the problem of electrical or electromagnetic scattering from thin conductors, either on a line or in a plane, has been motivated in recent years by time-lapse fracture monitoring in the near surface, enhanced geothermal reservoirs, and unconventional hydrocarbon plays. However, finite-element modeling of small electrical features in large computational domains results in a disproportionately large number of elements concentrated in a volumetrically insignificant fraction of the mesh, and it focuses computational resources away from areas of interest elsewhere, such as receiver locations. We have developed a novel hierarchical electrical model is proposed for unstructured tetrahedral finite-element meshes, in which the usual volume-based conductivity on tetrahedra is augmented by facet- and edge-based conductivity on the infinitesimally thin regions between elements. Doing so allows a slender borehole casing of arbitrary shape to be coarsely approximated by set of connected edges on which a conductivity-area product is explicitly defined. Similarly, conductive fractures are approximated by a small number of connected facets that, together, may warp and bend with the mesh topology at no added cost of localized mesh refinement. Benchmarking tests of the direct current (DC) resistivity problem indicate excellent agreement between the facet/edge representations and independent analytic solutions. Consistency tests are also favorable between the facet/edge and volume representations. Building on prior work in DC modeling of a single horizontal well, a multilateral well casing and fracture set is simulated, yielding estimates of borehole casing voltage and surface electric fields measurable with existing sensor technology. Finally, the implications on broadband electromagnetic simulation with the proposed hierarchical conductivity model are discussed — in particular, its utility for describing variations in the magnetic permeability and electrical conductivity.
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Loken, Michael R., Andrew P. Voigt, Robert B. Gerbing, Lisa Eidenschink Brodersen, Andrew J. Menssen, Laura Pardo, Alan S. Gamis, Todd A. Alonzo, and Soheil Meshinchi. "Heirarchical Clustering of Immunophenotypic Cell Surface Antigen Expression Identifies Clinically Meaningful Cohorts in Childhood AML: A Report from the Children's Oncology Group Protocol AAML0531." Blood 126, no. 23 (December 3, 2015): 561. http://dx.doi.org/10.1182/blood.v126.23.561.561.
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Abstract Background: Acute myeloid leukemia (AML) is a heterogeneous disease with diverse cell surface antigen expression. Multidimensional flow cytometry (MDF) quantifies the expression of such surface antigens on neoplastic cells, permitting an objective means for sub-classification of this disorder. Objective: To investigate the relationship between the presenting immunophenotype and response to therapy in a large, controlled study of pediatric AML patients. Methods: Of 1022 newly diagnosed pediatric patients with de novo AML enrolled on protocol AAML0531, 769 satisfied three criteria for this study: (1) submission of a blood or bone marrow sample for MDF at diagnosis, (2) proper consent for specimen testing and (3) leukemia comprising >10% of non-erythroid cells by MDF. The diagnostic AML tumor population was identified by gating on CD45 vs log-SSC. A fifteen-dimensional immunophenotypic expression profile (IEP) was defined by computing mean fluorescent intensities, antigen intensity coefficient of variations, and light scatter characteristics of each leukemia without analyst imposed cut-offs. Unsupervised hierarchical clustering analysis was performed to mathematically define groups of patients with similar diagnostic IEPs. Selection of the appropriate number of clusters was accomplished by minimizing within-cluster variation while maximizing between-cluster variation. The rate of measurable residual disease (MRD) by MDF at the end of initial induction therapy (EOI1) and event free survival (EFS) was determined for each group and compared to the mean MRD rate and EFS for the entire cohort. Of the 769 total patients, 643 (84%) had bone marrow specimens submitted for MRD by MDF at EOI1. Results: Of the 643 patients with bone marrows submitted for MRD by MDF at EOI1, 223 (35%) were positive. The 5 year EFS rate was 49% for the study (N=769). Hierarchical clustering analysis of the IEPs defined 11 groups of patients (A-K) with similar quantitative diagnostic immunophenotypes. Five immunophenotypic groups of patients were associated with comparableEOI1 MRD rates (15%-36%) and EFS (50%-69%) to the study average. These 5 groups (A-E) consisted of immunophenotypes close to the normal counterpart of myeloid progenitor cells (Groups A, B, C; N=266, 77 and 106) or normal monocytes (Groups D and E; N=41 and 68). Two immunophenotypic groups (Group F and G) of patients were associated with significantly higher rates of MRD (Group F: 54%, p<0.001; Group G: 88%, p<0.001) and lower EFS (Group F: 28%, p<0.001; Group G: 19%, p=0.006) than average for the study. The defining different-from-normal immunophenotypic features of Group F (N=81) were expression of CD34 with a lack of HLA-DR. The defining immunophenotypic features of Group G (N=16) were high intensity CD56 expression, a lack of HLA-DR, dim-to-negative CD38 expression and dim-to-negative CD45 expression. The majority of patients in both groups were stratified as low or standard risk (86% and 100%). Three immunophenotypic groups (H-J) had low rates of MRD (20%-24%) but poor EFS (27%-39%). The defining different-from-normal immunophenotypic features of Group H (N=52) were expression of CD56 and CD13 with a lack of CD34. The defining different-from-normal immunophenotypic features of Group I (N=11) were CD34 positive expression with a lack of CD117. The defining different-from-normal features of Group J (N=28) were bright CD11b expression with a lack of CD34 and CD117. The majority of patients in these groups were stratified as standard risk (94%, 100%, and 75% respectively). One immunophenotypic group (K) had a high rate of MRD (50%) and comparable EFS (52%) to the study average. The defining different-from-normal features of Group K (N=23) were expression of CD56 with a lack of CD34 and CD13. Conclusions: IEPs can provide a powerful tool to discriminate patient cohorts that have a high probability of relapse and subsequently elucidate when MRD by MDF at EOI1 is predictive of patient outcome. Notably 2 IEP groups (97 patients, 13% of total) had significantly higher MRD rates and were associated with a high probability of disease relapse. IEPs can identify these 2 groups of patients otherwise stratified as good or standard risk, which can provide clinicians with an additional analytical method to more appropriately stratify patients. Disclosures Loken: Hematologics Inc.: Equity Ownership. Voigt:Hematologics Inc.: Employment. Brodersen:Hematologics Inc.: Employment. Menssen:Hematologics Inc.: Employment. Pardo:Hematologics Inc.: Employment.
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Morelli, L., V. D. Ivanov, A. Pizzella, D. Gasparri, L. Coccato, E. M. Corsini, E. Dalla Bontà, P. François, and M. Cesetti. "The Infrared Telescope Facility (IRTF) spectral library." Astronomy & Astrophysics 641 (September 2020): A44. http://dx.doi.org/10.1051/0004-6361/202037505.
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Context. Stellar population studies in the infrared (IR) wavelength range have two main advantages with respect to the optical regime: they probe different populations, because most of the light in the IR comes from redder and generally older stars, and they allow us to see through dust because IR light is less affected by extinction. Unfortunately, IR modeling work was halted by the lack of adequate stellar libraries, but this has changed in the recent years. Aims. Our project investigates the sensitivity of various spectral features in the 1−5 μm wavelength range to the physical properties of stars (Teff, [Fe/H], log g) and aims to objectively define spectral indices that can characterize the age and metallicity of unresolved stellar populations. Methods. We implemented a method that uses derivatives of the indices as functions of Teff, [Fe/H] or log g across the entire available wavelength range to reveal the most sensitive indices to these parameters and the ranges in which these indices work. Results. Here, we complement the previous work in the I and K bands, reporting a new system of 14, 12, 22, and 12 indices for Y, J, H, and L atmospheric windows, respectively, and describe their behavior. We list the equivalent widths of these indices for the Infrared Telescope Facility (IRTF) spectral library stars. Conclusions. Our analysis indicates that features sensitive to the effective temperature are present and measurable in all the investigated atmospheric windows at the spectral resolution and in the metallicity range of the IRTF library for a signal-to-noise ratio greater than 20−30. The surface gravity is more challenging and only indices in the H and J windows are best suited for this. The metallicity range of the stars with available spectra is too narrow to search for suitable diagnostics. For the spectra of unresolved galaxies, the defined indices are valuable tools in tracing the properties of the stars in the IR-dominant stellar populations.
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Wheatley, Dustan M., David J. Stensrud, David C. Dowell, and Nusrat Yussouf. "Application of a WRF Mesoscale Data Assimilation System to Springtime Severe Weather Events 2007–09." Monthly Weather Review 140, no. 5 (May 1, 2012): 1539–57. http://dx.doi.org/10.1175/mwr-d-11-00106.1.
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Abstract An ensemble-based data assimilation system using the Weather Research and Forecasting Model (WRF) has been used to initialize forecasts of prolific severe weather events from springs 2007 to 2009. These experiments build on previous work that has shown the ability of ensemble Kalman filter (EnKF) data assimilation to produce realistic mesoscale features, such as drylines and convectively driven cold pools, which often play an important role in future convective development. For each event in this study, severe weather parameters are calculated from an experimental ensemble forecast started from EnKF analyses, and then compared to a control ensemble forecast in which no ensemble-based data assimilation is performed. Root-mean-square errors for surface observations averaged across all events are generally smaller for the experimental ensemble over the 0–6-h forecast period. At model grid points nearest to tornado reports, the ensemble-mean significant tornado parameter (STP) and the probability that STP > 1 are often greater in the experimental 0–6-h ensemble forecasts than in the control forecasts. Likewise, the probability of mesoscale convective system (MCS) maintenance probability (MMP) is often greater with the experimental ensemble at model grid points nearest to wind reports. Severe weather forecasts can be sharpened by coupling the respective severe weather parameter with the probability of measurable rainfall at model grid points. The differences between the two ensembles are found to be significant at the 95% level, suggesting that even a short period of ensemble data assimilation can yield improved forecast guidance for severe weather events.
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Anand, M., S. S. Russell, R. L. Blackhurst, and M. M. Grady. "Searching for signatures of life on Mars: an Fe-isotope perspective." Philosophical Transactions of the Royal Society B: Biological Sciences 361, no. 1474 (September 7, 2006): 1715–20. http://dx.doi.org/10.1098/rstb.2006.1899.
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Recent spacecraft and lander missions to Mars have reinforced previous interpretations that Mars was a wet and warm planet in the geological past. The role of liquid water in shaping many of the surface features on Mars has long been recognized. Since the presence of liquid water is essential for survival of life, conditions on early Mars might have been more favourable for the emergence and evolution of life. Until a sample return mission to Mars, one of the ways of studying the past environmental conditions on Mars is through chemical and isotopic studies of Martian meteorites. Over 35 individual meteorite samples, believed to have originated on Mars, are now available for lab-based studies. Fe is a key element that is present in both primary and secondary minerals in the Martian meteorites. Fe-isotope ratios can be fractionated by low-temperature processes which includes biological activity. Experimental investigations of Fe reduction and oxidation by bacteria have produced large fractionation in Fe-isotope ratios. Hence, it is considered likely that if there is/were any form of life present on Mars then it might be possible to detect its signature by Fe-isotope studies of Martian meteorites. In the present study, we have analysed a number of Martian meteorites for their bulk-Fe-isotope composition. In addition, a set of terrestrial analogue material has also been analysed to compare the results and draw inferences. So far, our studies have not found any measurable Fe-isotopic fractionation in bulk Martian meteorites that can be ascribed to any low-temperature process operative on Mars.
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Watanabe, Mari, Kazuya Matsuzaki, Osamu Sato, Yoshiya Fukuhara, and Masato Terasawa. "Feasibility Study of Performance Assessment Gauge for Freeform Measurement." International Journal of Automation Technology 15, no. 6 (November 5, 2021): 824–30. http://dx.doi.org/10.20965/ijat.2021.p0824.
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Recent product components have been designed as a combination of complex forms for advanced functionality. Such high degree-of-freedom forms are shaped by various manufacturing processes. In the industrial supply chain, the deviation of a manufactured form from its designed form must be verified to ensure product quality. Three-dimensional (3D) measuring systems are typically used for verification. To validate the product manufacturing performance accurately, a measurement procedure that can derive the measurands of forms with small measurement uncertainty is necessitated. For simple geometries such as flats, spheres, and cylinders, precise measurement and uncertainty evaluation methods have been established; however, those for complex forms are still being developed. In this study, measurement uncertainty is assessed by measuring a calibrated gauge and comparing the measured with calibrated values. Several gauges configured with basic geometric elements have been proposed as a reference for complex form measurements, and some issues remain. Some of the gauges do not sufficiently simulate the forms of actual product components, whereas other gauges are difficult to calibrate with small uncertainties. Herein, we discuss a possible approach for solving these problems in the metrology of complex forms using 3D measuring systems. First, a new gauge concept is proposed. The gauge is designed by extracting the complex features of the actual product form and segmenting the gauge’s form into various circular arc curvatures. The geometric parameters are well calibrated, and the measurable angular range of the curvature is not limited. A representative gauge based on this concept is described. Next, a robust and small-uncertainty calibration method for complex-form objects is described. The area encompassing the target cross-section is measured, and an envelope is generated on the probe tip mechanical surface from the probe tip centers to determine the measured surface. Finally, the calibration and measurement uncertainty evaluation for the geometric parameters of the new gauge are quantitatively presented. It is verified that the proposed calibration procedure is applicable to freeform measurements, and that both simple and complex forms can be measured within a 1.5 μm uncertainty.
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van der Wal, Wouter, and Thijs IJpelaar. "The effect of sediment loading in Fennoscandia and the Barents Sea during the last glacial cycle on glacial isostatic adjustment observations." Solid Earth 8, no. 5 (September 21, 2017): 955–68. http://dx.doi.org/10.5194/se-8-955-2017.
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Abstract. Models for glacial isostatic adjustment (GIA) routinely include the effects of meltwater redistribution and changes in topography and coastlines. Since the sediment transport related to the dynamics of ice sheets may be comparable to that of sea level rise in terms of surface pressure, the loading effect of sediment deposition could cause measurable ongoing viscous readjustment. Here, we study the loading effect of glacially induced sediment redistribution (GISR) related to the Weichselian ice sheet in Fennoscandia and the Barents Sea. The surface loading effect and its effect on the gravitational potential is modeled by including changes in sediment thickness in the sea level equation following the method of Dalca et al. (2013). Sediment displacement estimates are estimated in two different ways: (i) from a compilation of studies on local features (trough mouth fans, large-scale failures, and basin flux) and (ii) from output of a coupled ice–sediment model. To account for uncertainty in Earth's rheology, three viscosity profiles are used. It is found that sediment transport can lead to changes in relative sea level of up to 2 m in the last 6000 years and larger effects occurring earlier in the deglaciation. This magnitude is below the error level of most of the relative sea level data because those data are sparse and errors increase with length of time before present. The effect on present-day uplift rates reaches a few tenths of millimeters per year in large parts of Norway and Sweden, which is around the measurement error of long-term GNSS (global navigation satellite system) monitoring networks. The maximum effect on present-day gravity rates as measured by the GRACE (Gravity Recovery and Climate Experiment) satellite mission is up to tenths of microgal per year, which is larger than the measurement error but below other error sources. Since GISR causes systematic uplift in most of mainland Scandinavia, including GISR in GIA models would improve the interpretation of GNSS and GRACE observations there.
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Conte, Claudia, Giovanni Dal Poggetto, Benjamin J. Swartzwelter, Diletta Esposito, Francesca Ungaro, Paola Laurienzo, Diana Boraschi, and Fabiana Quaglia. "Surface Exposure of PEG and Amines on Biodegradable Nanoparticles as a Strategy to Tune Their Interaction with Protein-Rich Biological Media." Nanomaterials 9, no. 10 (September 20, 2019): 1354. http://dx.doi.org/10.3390/nano9101354.
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Nanoparticles (NPs) based on amphiphilic block copolymers of polyethylene glycol (PEG) and biodegradable polyesters are of particular current interest in drug nanodelivery due to their easily manipulated properties. The interaction of these NPs with biological environments is highly influenced by shell features, which drive biological identity after administration. To widen the strategies available for tuning particle surface chemistry, here we developed a panel of amine-bearing PEGylated NPs with a poly(ε-caprolactone) (PCL) core for the delivery of lipophilic drugs, and investigated the impact of NP modifications on their interaction with abundant circulating proteins (human serum albumin—HSA—and mucin), as well as their transport through biological barriers (artificial mucus—AM, extracellular matrix—ECM). We prepared NPs based on a diamino-terminated PCL (amine-NPs) and its mixture with PEG-PCL copolymers (amine/PEG-NPs) at different PEG molecular weights by nanoprecipitation, as well as corresponding NPs of PEG-PCL (PEG-NPs). The presence of an amine-bearing polymer resulted in NPs with a net positive charge and a zeta potential dependent on the length of PEG in the copolymer. Amine/PEG-NPs had a larger fixed aqueous layer thickness as compared to PEG-NPs, suggesting that PEG conformation is affected by the presence of positive charges. In general, amine-bearing NPs promptly interacted with the dysopsonic protein HSA, due to electrostatic interactions, and lose stability, thereby undergoing time-related aggregation. On the other hand, amine/PEG-NPs interaction with mucin induced switching to a negative surface charge but did not alter the quality of the dispersion. The transport kinetics of NPs through a layer of artificial mucus and tumor extracellular matrix was studied by means of fluorescent NPs based upon FRET. Amine/PEG-NPs did not cross the ECM, but they were promptly transported through the AM, with swifter transport noted at increasing MWs of PEG in the copolymer. Finally, we demonstrated that all the different NP types developed in this study are internalized by human monocytes and, despite the positive charge, they did not induce a measurable inflammatory effect. In conclusion, we showed that the concurrent presence of both PEG and amine groups on NP surface is a promising strategy for directing their interaction with body compartments. While PEG-NPs are confirmed for their capacity to cross ECM-like compartments, amine/PEG-NPs are revealed as a powerful platform to widen the arsenal of nanotools available for overcoming mucus-covered epithelia.
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Venanzi, Rachele, Rodolfo Picchio, Stefano Grigolato, and Raffaele Spinelli. "Soil Disturbance Induced by Silvicultural Treatment in Chestnut (Castanea sativa Mill.) Coppice and Post-Disturbance Recovery." Forests 11, no. 10 (September 29, 2020): 1053. http://dx.doi.org/10.3390/f11101053.
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Chestnut forests represent an important environmental and landscape element in Europe, especially in the hill regions of southern Europe. In Italy, the total surface amount of chestnut forests is slightly expanded with 788,408 hectares, but orchards show a dramatic reduction (147,586 hectares or 20% of the total) and timber-producing stands a comparable expansion (605,888 hectares or 80%). The coppice management actually applied is considered one of the oldest forms of sustainable forest management. Over the years, coppice highlighted its versatility, resilience and multifunctionality. In this management system, in consideration of the “frequent” cutting cycles, special attention must be paid to forestry operations, because tree damage and soil compaction can trigger fungal disease and soil erosion. Frequent and repeated machine traffic increases the risk for soil degradation derived from compaction, topsoil removal and general disturbance. This study covered different forest areas and mechanization levels, in order to evaluate if the extent, type and severity of soil disturbance changed with site characteristics and logging technique. Furthermore, the study sought to obtain a better knowledge about the recovery time required for restoring the original soil properties after a disturbance has occurred. The findings showed that physical, chemical, and biological soil features were only partially disturbed by the coppicing and again that a high level of specialized mechanization does not generate heavier soil impact compared with the smaller and lighter machines deployed under the traditional and intermediate mechanization scenarios. Soil recovery in the impacted areas is already measurable one year after harvest and may be complete within the eight year—that is halfway through the standard rotation applied in the region to chestnut coppice.
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Vuillemin, A., D. Ariztegui, P. R. Leavitt, and L. Bunting. "Recording of climate and diagenesis through fossil pigments and sedimentary DNA at Laguna Potrok Aike, Argentina." Biogeosciences Discussions 12, no. 22 (November 16, 2015): 18345–88. http://dx.doi.org/10.5194/bgd-12-18345-2015.
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Abstract. Aquatic sediments record past climatic conditions while providing a wide range of ecological niches for microorganisms. Although marine sedimentary microbial assemblages are often defined by their surrounding geochemical conditions, the influence of environmental features upon microbial development and post-depositional survival remains largely unknown in the lacustrine realm. Due to long-term microbial activity, the composition of environmental DNA can be expected to evolve with sediment depth and over time and therefore should reflect both ancient and extant microbial populations, but this hypothesis has rarely been tested using a multiproxy approach. Here geomicrobiological and phylogenetic analyses of a Patagonian maar lake were used to indicate that the different sedimentary microbial assemblages derive from specific lacustrine regimes during defined climatic periods. Two well defined climatic intervals whose sediments harboured active microbial populations and measurable ATP were sampled for a comparative environmental study based on fossil pigments and 16S rRNA gene sequences. Bacterial and archaeal 16S rRNA gene sequences recovered from the Holocene record revealed a microbial community adapted to subsaline conditions actively producing methane during organic matter degradation. These characteristics were associated with sediments resulting from endorheic lake conditions with high evaporative stress and concomitant high algal productivity. Moreover, archaeal clone libraries established throughout the Holocene record indicate an age-related stratification of these populations, consistent with a gradual use of organic substrates after deposition. In contrast, sulphate-reducing bacteria and lithotrophic Archaea were predominant in sediments dated from the Last Glacial Maximum, in which pelagic clays alternated with fine volcanic material characteristic of a lake level highstand and freshwater conditions, but reduced water column productivity. These patterns reveal that microbial assemblages identified from environmental DNA stemmed from a variety of sedimentary niches associated with climate-dependent factors (catchment inflows, water column conditions, productivity), but that initial assemblages underwent structural changes and selective preservation during early diagenesis to result in the final composition entombed in the sediments. We conclude that environmental DNA obtained from lacustrine sediments provides essential genetic information to complement paleoenvironmental indicators and trace climate change and post-depositional diagenetic processes over tens of millennia.
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BESHENSKY, ANN M., JEFFREY A. WESSON, ELAINE M. WORCESTER, ELENA J. SOROKINA, CARL J. SNYDER, and JACK G. KLEINMAN. "Effects of Urinary Macromolecules on Hydroxyapatite Crystal Formation." Journal of the American Society of Nephrology 12, no. 10 (October 2001): 2108–16. http://dx.doi.org/10.1681/asn.v12102108.
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Abstract. Particle size analysis was combined with titration data obtained in constant-composition, hydroxyapatite (HA)-seeded, crystal growth assays. With addition of large amounts of HA (250 μg), titration rates were linear, new crystal formation was minimal, and aggregation effects could be detected. With addition of small amounts of HA (62.5 μg), nucleation of new HA was observed. The effects of urinary macromolecules, i.e., osteopontin (OPN), recombinant glutathione-S-transferase-OPN (G-OPN), Tamm-Horsfall protein, chondroitin sulfate, human serum albumin, mixed urinary macromolecules from a stone-former (SFU1), mixed urinary macromolecules from a normal individual (NU1), and polyaspartic acid (PA), were examined in this system. Crystal growth inhibition, as measured by the slope of linear titration curves in this system, was observed with PA, G-OPN, OPN, SFU1, and NU1. All of the macromolecules tested inhibited aggregation, including Tamm-Horsfall protein, which did not inhibit growth. As reflected by the ratio of the final number of particles to the initial number in the 62.5-μg seed addition, the macromolecules that were most effective in inhibiting growth, i.e., OPN, G-OPN, PA, SFU1, and NU1, actually increased secondary nucleation. Recombinant G-OPN demonstrated less inhibitory activity than did OPN isolated from cell culture. Chondroitin sulfate and human serum albumin exhibited no significant effects on the various components of HA crystallization under these conditions. SFU1 and NU1 slowed growth and increased secondary nucleation to similar degrees, and neither exhibited any measurable effect on aggregation. Therefore, crystal surface sites that participate in nucleation, growth, and aggregation processes are affected independently by macromolecules, presumably because of differences in their structural features. These results illustrate the utility of combining these techniques to provide a much greater understanding of crystallization behavior than that possible with either analysis alone.
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Kuswandi, Bambang, Mochammad Amrun Hidayat, and Eka Noviana. "Paper-Based Electrochemical Biosensors for Food Safety Analysis." Biosensors 12, no. 12 (November 28, 2022): 1088. http://dx.doi.org/10.3390/bios12121088.
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Nowadays, foodborne pathogens and other food contaminants are among the major contributors to human illnesses and even deaths worldwide. There is a growing need for improvements in food safety globally. However, it is a challenge to detect and identify these harmful analytes in a rapid, sensitive, portable, and user-friendly manner. Recently, researchers have paid attention to the development of paper-based electrochemical biosensors due to their features and promising potential for food safety analysis. The use of paper in electrochemical biosensors offers several advantages such as device miniaturization, low sample consumption, inexpensive mass production, capillary force-driven fluid flow, and capability to store reagents within the pores of the paper substrate. Various paper-based electrochemical biosensors have been developed to enable the detection of foodborne pathogens and other contaminants that pose health hazards to humans. In this review, we discussed several aspects of the biosensors including different device designs (e.g., 2D and 3D devices), fabrication techniques, and electrode modification approaches that are often optimized to generate measurable signals for sensitive detection of analytes. The utilization of different nanomaterials for the modification of electrode surface to improve the detection of analytes via enzyme-, antigen/antibody-, DNA-, aptamer-, and cell-based bioassays is also described. Next, we discussed the current applications of the sensors to detect food contaminants such as foodborne pathogens, pesticides, veterinary drug residues, allergens, and heavy metals. Most of the electrochemical paper analytical devices (e-PADs) reviewed are small and portable, and therefore are suitable for field applications. Lastly, e-PADs are an excellent platform for food safety analysis owing to their user-friendliness, low cost, sensitivity, and a high potential for customization to meet certain analytical needs
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Niekurzak, Mariusz, and Ewa Kubińska-Jabcoń. "Assessment of the Impact of Wear of the Working Surface of Rolls on the Reduction of Energy and Environmental Demand for the Production of Flat Products: Methodological Approach." Materials 15, no. 6 (March 21, 2022): 2334. http://dx.doi.org/10.3390/ma15062334.
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An important element in the correct operation of the rolling mill is appropriate planning of the condition of the rolls because this factor constitutes a limiting element in the production process. In this work, with the aim of indicating the method of proper use of production tools–metallurgical rollers during their operation in a Polish rolling mill, the wear and tear of particular kinds of rollers built in the whole rolling set was determined. For this purpose, data were collected at the strip mill from grinding processes, production reports and roll files, while our statistical analysis, laboratory calculations and measurements were used. These data were used to perform computer calculations on the service life of metallurgical rollers installed in the rolling line. Wear mechanisms were identified in industrial practice. The characteristic features of roller wear were investigated using non-destructive tests, including eddy currents. The laboratory tests reproduced the wear mechanisms in very hot rolling rolls. The statistical method for determining the service life of working rolls indicated that their reconstruction is determined both by natural physical phenomena and inappropriate use in about 30% of cases, mainly in the F5 and F6 cages of the finishing unit. Calculations indicated the possibility of replacing the working rolls made of high chromium cast iron Hi-Cr with those made of HSS in the F5 and F6 cages, which will contribute to an increase in the durability of the rolls, a reduction in production costs and a decrease in the number of roll rebuildings. The service life of HSS rolls is 14,000–20,000 Mg of rolled material per 1 mm of wear on its surface in the radial direction, compared to 2000 Mg for rolls made of high chromium cast iron Hi-Cr. The constructed model may be a source of information for further analyses and decision-making processes supporting the management of metallurgical enterprises. On the basis of the constructed model, it was shown that the analyzed projects, depending on their type and technical specification, will bring measurable economic benefits in the form of reduced annual energy consumption and environmental benefits in the form of reduced carbon dioxide emissions into the atmosphere. The constructed model of the roll consumption, verified in the real conditions of the rolling mills, will contribute to the fulfillment of energy and emission obligations with the EU.
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Ulbrich, Carlton W., and David Atlas. "Microphysics of Raindrop Size Spectra: Tropical Continental and Maritime Storms." Journal of Applied Meteorology and Climatology 46, no. 11 (November 1, 2007): 1777–91. http://dx.doi.org/10.1175/2007jamc1649.1.
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Abstract This work uses raindrop size spectra measured at the surface in tropical continental storms to determine the associated parameters of the best-fit gamma distributions. The physical processes responsible for those parameters and their relations to the measurable radar reflectivity Z and differential reflectivity ZDR are then explored. So too are their relations to quantitative measurements of rain. Comparison is then made with corresponding features previously reported in tropical maritime regimes. The storms observed in Brazil and Arecibo, Puerto Rico, have been divided into convective (C), transition (T), and stratiform (S) segments. The raindrop size distribution (DSD) parameters are clearly defined on a gamma parameter diagram (GPD) that shows 1) how median volume drop size D0 increases from S to T to C segments of the rain while 2) the range of the spectrum breadth parameter μ increases, and the range of the slope parameter Λ decreases in the same sequence of S to C. Drop growth occurs predominantly below the 0°C level by collision, coalescence, and breakup in the C rains. The median volume diameter D0 grows as more of the water is concentrated near that size and so the DSD narrows; that is, both μ and Λ increase. In both maritime and continental storms the DSD in the convective portion of the storm approaches equilibrium. The coefficient A in the Z = ARb relation increases with D0 while the exponent b approaches unity. The D0 and A pair increase with, and appear to be determined largely by, the updraft strength, thus providing a possible means of determining the appropriate algorithms for rainfall measurement. Although the small drop number samples measured by the surface disdrometer relative to the large volumes sampled by a radar tend to truncate the DSD at both small and large drop sizes, narrow distributions with μ = 5 to 12 cannot be attributed to such an effect. Such narrow DSDs accord with common experience of monodispersed large drops at the beginning of a convective storm. There is also remarkable agreement of the surface-based observations of ZDR–Z–D0 with the time–space variations from C to T to S rain types observed by radar in England and elsewhere. Because the C region of a storm often accounts for a major share of the rain accumulation despite its shorter duration, it is particularly important to measure that region more accurately. There are distinctive clusters of the generalized number parameter NW versus D0 between maritime and continental storms. Methods for remote sensing and parameterization must partition the rainstorms into convective, transition, and stratiform segments.
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Foster, Matthew C., Yuri Fedoriw, Will Pulley, Joshua Zeidner, Catherine C. Coombs, Emily Mirkin, Maryam Zomorrodi, et al. "Detection of Measurable Residual Disease (MRD) in Peripheral Blood: First Report of a Novel Microfluidic Platform in Patients with Acute Myeloid Leukemia (AML)." Blood 134, Supplement_1 (November 13, 2019): 1417. http://dx.doi.org/10.1182/blood-2019-127434.
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Background: Despite therapeutic advances, AML remains a disease in which the majority of patients relapse after attaining remission. The presence of bone marrow MRD is associated with impending AML relapse. Prediction and prevention of relapse could improve outcomes, but most current MRD tests either require bone marrow aspirate or detect individualized molecular genetic features present in a minority of AML. Furthermore, bone marrow MRD assessments are impractical if performed frequently enough to detect most early relapses. We developed and tested a novel microfluidic chip device (MCD) that can quantitate cell numbers using automated methods and explored its ability to detect low levels of peripheral blood leukemic cells with aberrant immunophenotypes. Methods: The MCD contains sinusoidal capture channels that were coated with antibodies with specificity towards one of the commonly expressed markers found on immature myeloid cells--CD33, CD34 and CD117 (capture antigens). Initial spiking experiments used fluorescently labeled leukemia cell lines HL60 (CD33+), KG1 (CD34+), Kasumi1 (CD117+) spiked into a 5000 cell/mL suspension. Cell suspensions were passed through MCDs coated with a capture antigen known to be expressed on the tested cell line. These experiments established an efficient capture using a flow rate of 1mL/sec. Then, AML patients with an aberrant immunophenotype were enrolled in a pilot study either at the start of induction chemotherapy or prior to allogeneic stem cell transplant (SCT). For patients receiving induction chemotherapy, whole blood samples were obtained monthly starting at the time of remission assessment, or monthly starting prior to SCT. Buffered whole blood was passed through MCDs coated with a capture antigen known to be expressed on patient myeloblasts. The captured cells were then released, eluted, centrifuged and plated on a glass slide. Plated cell pellets were then labeled with fluorescent antibodies targeting surface proteins known to be aberrantly (either by lineage infidelity or asynchronous expression) expressed on the patients' AML blasts. Automated fluorescence microscopy was used to identify and quantify captured cells with the known aberrant immunophenotype of the AML blasts. Descriptive statistics described serial cell counts in patients maintaining remission and relapsing patients. Results: Of 31 patients who have been enrolled in the study to date, 13 had at least 3 post-remission MCD analyses. Of these patients, 6 had either morphologic relapse or persistent/rising marrow MRD. In these patients, there was a trend towards higher initial aberrant immunophenotype cell counts, with mean initial count = 59 (95% CI 1, 108), compared to other patients with mean initial count = 15 (95% CI 5, 25). Of 5 patients who relapsed with MCD data within 1 month prior to relapse, the mean absolute rise prior to relapse above minimum MCD cell count was 54 (95% CI 2, 105), in comparison to non-relapsing patients with mean rise of 9 (95% CI 3, 15). From the initial 16 patients, 10 underwent induction therapy (the other 6 were enrolled prior to SCT). In these 10 patients there was a non-significant association between peripheral blood aberrant immunophenotype cells and remission status following induction. A total of 8 patients underwent allogeneic SCT. Two of these patients had known bone marrow MRD at the time of SCT and had a statistically significant greater number of aberrant immunophenotypic cells pre-SCT (48 and 60) compared to the 6 MRD negative patients (median = 12, range 9, 42). Conclusions: A novel MCD assay can reliably capture and detect low numbers of AML blasts from peripheral blood using immunofluorescent imaging and automated cell counts to quantify leukemia cells with aberrant immunophenotypes. Because this method uses peripheral blood, frequent sampling is feasible and of minimal risk to patients. An ongoing clinical trial will further explore the associations between MCD-based cell enumeration and clinical endpoints in AML patients that were suggested in the pilot phase of this study. Because the MCD releases trace populations of viable cells, additional experiments, such as primary cell culturing and single cell sequencing, are possible. Figure Disclosures Foster: Bellicum Pharmaceuticals, Inc: Research Funding; Daiichi Sankyo: Consultancy; MacroGenics: Research Funding; Celgene: Research Funding. Fedoriw:Alexion Pharmaceuticals: Consultancy, Speakers Bureau. Zeidner:Celgene: Consultancy, Honoraria, Research Funding; AsystBio Laboratories: Consultancy; Merck: Research Funding; Covance: Consultancy; Pfizer: Honoraria; Agios: Honoraria; Daiichi Sankyo: Honoraria; Tolero: Honoraria, Research Funding. Coombs:Covance: Consultancy; Octopharma: Honoraria; Medscape: Honoraria; Cowen & Co.: Consultancy; Loxo: Honoraria; H3 Biomedicine: Honoraria; Dedham Group: Consultancy; Pharmacyclics: Honoraria; Abbvie: Consultancy. Mirkin:BioFluidica: Employment. Zomorrodi:BioFluidica: Employment. Toughiri:BioFluidica: Employment. Bartakova:BioFluidica: Employment. Carson:BioFluidica: Employment. Muller:BioFluidica: Employment.
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Boxhammer, Elke, Bernhard Scharinger, Reinhard Kaufmann, Herwig Brandtner, Lukas Schmidbauer, Jürgen Kammler, Jörg Kellermair, et al. "Comparability between Computed Tomography Morphological Vascular Parameters and Echocardiography for the Assessment of Pulmonary Hypertension in Patients with Severe Aortic Valve Stenosis—Results of a Multi-Center Study." Diagnostics 12, no. 10 (September 29, 2022): 2363. http://dx.doi.org/10.3390/diagnostics12102363.
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Background: Computed tomography (CT) of the aorta and cardiac vessels, which is performed in patients with severe aortic valve stenosis (AS) before transcatheter aortic valve replacement (TAVR), offers the possibility of non-invasive detection of pulmonary hypertension (PH), for example, by determining the diameter of the main pulmonary artery (PA), the right pulmonary artery (RPA) or the left pulmonary artery (LPA). An improvement of the significance of these radiological parameters is often achieved by indexing to the body surface area (BSA). The aim of this study was to compare different echocardiographic systolic pulmonary artery pressure (sPAP) values with radiological data in order to define potential clinical cut-off values for the presence or absence of PH. Methods: A total of 138 patients with severe AS undergoing TAVR underwent pre-interventional transthoracic echocardiography with determination of sPAP values and performance of CT angiography (CTA) of the aorta and femoral arteries. Radiologically, the PA, RPA, LPA, and ascending aorta (AA) diameters were obtained. Vascular diameters were not only indexed to BSA but also ratios were created with AA diameter (for example PA/AA-ratio). From these CT-derived vascular parameters, AUROC curves were obtained regarding the prediction of different sPAP values (sPAP 40–45–50 mmHg) and finally correlation analyses were calculated. Results: The best AUROC and correlation analyses were generally obtained at an sPAP ≥ 40 mmHg. When considering diameters alone, the PA diameter was superior to the RPA and LPA. Indexing to BSA generally increased the diagnostic quality of the parameters, and finally, in a synopsis of all results, PA/BSA had the best AUC 0.741 (95% CI 0.646–0. 836; p < 0.001; YI 0.39; sensitivity 0.87; specificity 0.52) and Spearman’s correlation coefficient (r = 0.408; p < 0.001) at an sPAP of ≥40 mmHg. Conclusions: Features related to pulmonary hypertension are fast and easily measurable on pre-TAVR CT and offer great potential regarding non-invasive detection of pulmonary hypertension in patients with severe AS and can support the echocardiographic diagnosis. In this study, the diameter of the main pulmonary artery with the additionally determined ratios were superior to the values of the right and left pulmonary artery. Additional indexing to body surface area and thus further individualization of the parameters with respect to height and weight can further improve the diagnostic quality.
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Zhigarev, Dmitry, Alexander W. MacFarlane, Christina Diane Drenberg, Reza Nejati, Asya Varshavsky, and Kerry S. Campbell. "NK Cells of Acute Myeloid Leukemia Patients Exhibit Exhausted Phenotype with Impaired Functional Activity." Blood 138, Supplement 1 (November 5, 2021): 4466. http://dx.doi.org/10.1182/blood-2021-151550.
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Abstract Acute myeloid leukemia (AML) accounts for about one third of all leukemias, with half of all leukemia deaths. The low 5-year survival rate and manifestation of this deadly disease in old age reinforce the need for new safe and effective AML therapies. Considering the exceptional role of immune cells in the recognition and elimination of tumor cells, one of these methods is immunotherapy. However, for the development of immunotherapeutic approaches, it is necessary to clearly understand the role of certain effector cells in the pathogenesis of the disease, as well as to have the knowledge about the phenotypic characteristics of these cells. Natural killer (NK) cells play important roles in innate cancer immunosurveillance, and some published data indicate that the antitumor function of NK cells is reduced in AML patients. To expand upon previous work, we performed a comprehensive analysis of the phenotypic and functional characteristics of NK cells in previously untreated AML patients that took into account a wide variety of biomarkers. The goals of this study were to define the phenotypic and functional differences in NK cells from AML patients and healthy donors and determine how these parameters affect outcome of the disease. We used 14-color flow cytometry to assess more than 30 measurable markers on NK cells from the peripheral blood of 33 untreated AML patients and age-matched healthy controls. In addition, NK cells were tested for interferon-γ responses under antibody-dependent cellular cytotoxicity conditions. Results in AML patients were then compared to healthy donors. We found that the NK cells of patients with AML have a significantly lower capacity to secrete IFN-γ and showed numerous signs of an exhausted phenotype, as compared to healthy controls. These included increased surface expression of CD39, PD-1, and LILRB1 on NK cells from AML patients. Interestingly, surface expression of the TIGIT checkpoint receptor did not differ between AML patients and healthy donors, but surface expression of the activating receptor DNAM-1, which shares the same ligands on tumor cells, was decreased. All of these data confirm that the NK cells of AML patients are functionally impaired. We also noted that the frequency of CD57 + NKG2C + KIR + memory-like "adaptive" NK cells was greater in the blood of AML patients. The proportion of adaptive NK cells did not correlate with the age of donors. Phenotypic features of this cell subpopulation from the AML patients included significantly increased expression levels of CD56 and significantly lower expression of the activating receptor DNAM-1. Disclosures Zhigarev: Janssen R&D: Research Funding; Immunitas Therapeutics: Consultancy; Tavotek Biotherapeutics: Consultancy. Drenberg: Janssen R&D: Current Employment. Campbell: Janssen R&D: Research Funding.
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Kocharyan, G. G., and I. V. Batukhtin. "Laboratory studies of slip along faults as a physical basis for a new approach to short-term earthquake prediction." Geodynamics & Tectonophysics 9, no. 3 (October 9, 2018): 671–91. http://dx.doi.org/10.5800/gt-2018-9-3-0367.
Full textAbstract:
The physical effects that may prove useful for developing a new approach to short-term earthquake prediction have been studied in laboratory conditions. In seismology and earthquake foci mechanics, one of the major challenges is searching for indicators of an upcoming seismic event and attempting to reliably record such indicators by available instruments. In this regard, the best result of the laboratory studies of dynamic slip along faults would be the identification of specific macroscopic parameters controlling the deformation process, which are measurable in field. Dynamic stiffness of a fault zone seems to be an appropriate parameter. The recent laboratory experiments have shown that the value of this parameter predetermines the slip mode along the fault (unstable slip, creep, tremor, etc.), and a radical decrease in shear stiffness takes place as the fault zone reaches the metastable state. The effect discovered in the laboratory conditions gives grounds to suggest that changes in the stress-strain state of the fault zone at the final stage of earthquake preparation are detectable from the parameters of microseismic noise in the low-frequency range. Apparently, the noise records during and after the arrival of surface waves from distant earthquakes can provide the best opportunity for determining the parameters characterizing the study area. The wave oscillations with a period of a few dozen seconds have significant amplitudes and duration, which contributes to the excitation of resonance oscillations of the blocks. There are problems requiring additional laboratory experiments: estimating the size of a fault, which predetermines regularities in decreasing of the own frequency of the block-fault system; determining the ratio of the mechanical parameters of the fault in the nucleation zone and on the periphery of the future rupture, etc. Having analyzed the results of experimental studies carried out by other researchers, we conclude that laboratory experiments under normal conditions and low pressures can successfully address a number of fundamental issues on the way to creating a new approach to short-term earthquake prediction. Increasing pressure and temperature to values characteristic of seismogenic depths does not lead to the occurrence of any fundamentally new features in the behavior of the block-fault system at the stage when dynamic slip is being prepared. During slip, friction reduces due to melting, physical and chemical transformations at the micro- and nanoscales and other processes on the slipping surface, but these effects play no role at the stage when dynamic rock failure and the onset of slip are being prepared.