Journal articles on the topic 'Basal linear deposit'
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1
Loffler, K. U., and W. R. Lee. "Basal linear deposit in the human macula." Graefe's Archive for Clinical and Experimental Ophthalmology 224, no. 6 (November 1986): 493–501. http://dx.doi.org/10.1007/bf02154735.
2
Chen, Ling, Jeffrey D. Messinger, Deepayan Kar, Jacque L. Duncan, and Christine A. Curcio. "Biometrics, Impact, and Significance of Basal Linear Deposit and Subretinal Drusenoid Deposit in Age-Related Macular Degeneration." Investigative Opthalmology & Visual Science 62, no. 1 (January 29, 2021): 33. http://dx.doi.org/10.1167/iovs.62.1.33.
3
Curcio, Christine A. "Basal Linear Deposit and Large Drusen Are Specific for Early Age-Related Maculopathy." Archives of Ophthalmology 117, no. 3 (March 1, 1999): 329. http://dx.doi.org/10.1001/archopht.117.3.329.
4
Marshall, G. E., A. G. Konstas, G. G. Reid, J. G. Edwards, and W. R. Lee. "Type IV collagen and laminin in Bruch's membrane and basal linear deposit in the human macula." British Journal of Ophthalmology 76, no. 10 (October 1, 1992): 607–14. http://dx.doi.org/10.1136/bjo.76.10.607.
5
Moore, James A., David A. Hamilton Jr., Yu Xiao, and John Byrne. "Bedrock type significantly affects individual tree mortality for various conifers in the inland Northwest, U.S.A." Canadian Journal of Forest Research 34, no. 1 (January 1, 2004): 31–42. http://dx.doi.org/10.1139/x03-196.
Abstract:
Individual tree mortality models for western white pine (Pinus monticola Dougl. ex D. Don), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), western redcedar (Thuja plicata Donn ex. D. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western larch (Larix occidentalis Nutt.) were developed using data from permanent research plots located throughout the inland Northwest. The proposed linear logistic models included the following independent variables: diameter at breast height, basal area in larger trees, basal area per hectare, individual tree diameter increment, and a set of dummy variables for the six bedrock types, which were granite, basalt, metasedimentary, sedimentary, mixed glacial till, and deep deposit. The results show that rock type significantly affects individual tree mortality for western white pine, Douglas-fir, and western redcedar, while grand fir, western hemlock, and western larch were not affected. Western white pine and Douglas-fir growing on meta sedimentary rocks exhibited greater mortality probabilities than on other rocks. Mortality probabilities for western hemlock were low across all rock types, including "nutrient-poor" rocks like metasedimentary types.
6
Yu, Dan, Xinghui Huang, and Zhengyuan Li. "Variation patterns of landslide basal friction revealed from long-period seismic waveform inversion." Natural Hazards 100, no. 1 (October 23, 2019): 313–27. http://dx.doi.org/10.1007/s11069-019-03813-y.
Abstract:
Abstract A catastrophic landslide struck the Xiaoba village in Fuquan, Guizhou, southwestern China at about 8:30 p.m. (Beijing Time, UTC + 8) on August 27, 2014. The landslide and induced impulse water waves destroyed two villages and killed 23 persons. By reprocessing seismic signals from a seismic network deployed in the surrounding area of the landslide, we recognized the event from low-frequency seismic signals and subsequently performed a long-period seismic waveform inversion to obtain its force–time history. The inversion results reveal that the maximum force for the landslide is 5 × 109 N, and the duration of the landslide is 38.4 s. The landslide reached its maximum velocity of 12.4 m/s at 13.2 s after its initiation, and the mass center plugged into the quarry at 24.2 s. Based on the inversion results, we estimated basal friction of the landslide. We found the friction coefficient rapidly reduces to a relatively steady-state value of ~ 0.4 at a steady-state distance of 35 m and subsequently reduces in a near-linear manner that satisfies the empirical formula $$ \mu = - 1.4d + 0.44 $$μ=-1.4d+0.44, where $$ d $$d is sliding distance in km. The reduction in friction revealed by the formula is compatible with the finding of previous studies for landslides of similar volume in landslide acceleration stage. However, our result does not make it possible for the friction coefficient to increase again in landslide deceleration stage that a velocity-dependent friction law would allow. The friction variation patterns can be used to constrain input parameters in numerical landslide simulation, which can predicate runout distance and deposit areas for massive landslides to carry out landslide hazard assessment.
7
GRAY, J. M. N. T., and B. P. KOKELAAR. "Large particle segregation, transport and accumulation in granular free-surface flows." Journal of Fluid Mechanics 652 (May 19, 2010): 105–37. http://dx.doi.org/10.1017/s002211201000011x.
Abstract:
Particle size segregation can have a significant feedback on the motion of many hazardous geophysical mass flows such as debris flows, dense pyroclastic flows and snow avalanches. This paper develops a new depth-averaged theory for segregation that can easily be incorporated into the existing depth-averaged structure of typical models of geophysical mass flows. The theory is derived by depth-averaging the segregation-remixing equation for a bi-disperse mixture of large and small particles and assuming that (i) the avalanche is always inversely graded and (ii) there is a linear downslope velocity profile through the avalanche depth. Remarkably, the resulting ‘large particle transport equation’ is very closely related to the segregation equation from which it is derived. Large particles are preferentially transported towards the avalanche front and then accumulate there. This is important, because when this is combined with mobility feedback effects, the larger less mobile particles at the front can be continuously shouldered aside to spontaneously form lateral levees that channelize the flow and enhance run-out. The theory provides a general framework that will enable segregation-mobility feedback effects to be studied in detail for the first time. While the large particle transport equation has a very simple representation of the particle size distribution, it does a surprisingly good job of capturing solutions to the full theory once the grains have segregated into inversely graded layers. In particular, we show that provided the inversely graded interface does not break it has precisely the same solution as the full theory. When the interface does break, a concentration shock forms instead of a breaking size segregation wave, but the net transport of large particles towards the flow front is exactly the same. The theory can also model more complex effects in small-scale stratification experiments, where particles may either be brought to rest by basal deposition or by the upslope propagation of a granular bore. In the former case the resulting deposit is normally graded, while in the latter case it is inversely graded. These completely opposite gradings in the deposit arise from a parent flow that is inversely graded, which raises many questions about how to interpret geological deposits.
8
Zarbin, M. A. "Age-Related Macular Degeneration: Review of Pathogenesis." European Journal of Ophthalmology 8, no. 4 (October 1998): 199–206. http://dx.doi.org/10.1177/112067219800800401.
Abstract:
Age-related macular degeneration is a condition (a) characterized by accumulation of membranous debris on both sides of the retinal pigment epithelium (RPE) basement membrane. Clinical manifestations of drusen, atrophy of the RPE/choriocapillaris, RPE detachment, and choroidal new vessel (CNV) formation occur after age 50 years. A hypothetical pathogenic sequence of events consistent with known data is: 1) RPE dysfunction (e.g., precipitated by an inherited susceptibility and/or environmental exposure); 2) accumulation of intracellular material in the RPE (e.g., accumulation of normal substrate material that is not enzymatically degraded properly vs. abnormal substrate material); 3) abnormal accumulation of extracellular material (basal laminar and basal linear deposit); 4) change in Bruch's membrane composition (e.g., increased lipid deposition and protein crosslinking); 5) change in Bruch's membrane parmeability to nutrients (e.g., impaired diffusion of water soluble plasma constituents across Bruch's membrane); and 6) response of the RPE to metabolic distress (i.e., atrophy vs. CNV growth). Histopathological and clinical studies indicate that areas of choroidal ischemia often are seen near CNVs in AMD patients. In response to decreased oxygen delivery/metabolic “distress”, the RPE may elaborate substances leading to CNV growth. Perhaps RPE atrophy, followed by choriocapillaris and photoreceptor atrophy, is a response to decreased nutrients/increasing metabolic abnormalities in areas of excessive accumulation of extracellular debris. Unanswered questions regarding AMD include: 1) is AMD an ocular manifestation of a systemic disease or purely an ocular disease?; 2) what determines whether CNVs vs.atrophy of the RPE-choriocapillaris-photoreceptors develops?; and 3) what induces the maturation of CNVs into an inactive scar, and what limits the growth of most CNVs to the area centralis?
9
Pudasaini, S. P., Y. Wang, and K. Hutter. "Modelling debris flows down general channels." Natural Hazards and Earth System Sciences 5, no. 6 (October 26, 2005): 799–819. http://dx.doi.org/10.5194/nhess-5-799-2005.
Abstract:
Abstract. This paper is an extension of the single-phase cohesionless dry granular avalanche model over curved and twisted channels proposed by Pudasaini and Hutter (2003). It is a generalisation of the Savage and Hutter (1989, 1991) equations based on simple channel topography to a two-phase fluid-solid mixture of debris material. Important terms emerging from the correct treatment of the kinematic and dynamic boundary condition, and the variable basal topography are systematically taken into account. For vanishing fluid contribution and torsion-free channel topography our new model equations exactly degenerate to the previous Savage-Hutter model equations while such a degeneration was not possible by the Iverson and Denlinger (2001) model, which, in fact, also aimed to extend the Savage and Hutter model. The model equations of this paper have been rigorously derived; they include the effects of the curvature and torsion of the topography, generally for arbitrarily curved and twisted channels of variable channel width. The equations are put into a standard conservative form of partial differential equations. From these one can easily infer the importance and influence of the pore-fluid-pressure distribution in debris flow dynamics. The solid-phase is modelled by applying a Coulomb dry friction law whereas the fluid phase is assumed to be an incompressible Newtonian fluid. Input parameters of the equations are the internal and bed friction angles of the solid particles, the viscosity and volume fraction of the fluid, the total mixture density and the pore pressure distribution of the fluid at the bed. Given the bed topography and initial geometry and the initial velocity profile of the debris mixture, the model equations are able to describe the dynamics of the depth profile and bed parallel depth-averaged velocity distribution from the initial position to the final deposit. A shock capturing, total variation diminishing numerical scheme is implemented to solve the highly non-linear equations. Simulation results present the combined effects of curvature, torsion and pore pressure on the dynamics of the flow over a general basal topography. These simulation results reveal new physical insight of debris flows over such non-trivial topography. Model equations are applied to laboratory avalanche and debris-flow-flume tests. Very good agreement between the theory and experiments is established.
10
Wei, Chen, Lin Ye, Zhilong Huang, Wei Gao, Yusi Hu, Zhenli Li, and Jiawei Zhang. "Ore Genesis and Geodynamic Setting of Laochang Ag-Pb-Zn-Cu Deposit, Southern Sanjiang Tethys Metallogenic Belt, China: Constraints from Whole Rock Geochemistry, Trace Elements in Sphalerite, Zircon U-Pb Dating and Pb Isotopes." Minerals 8, no. 11 (November 8, 2018): 516. http://dx.doi.org/10.3390/min8110516.
Abstract:
The Laochang Ag-Pb-Zn-Cu deposit, located in the southern margin of the Sanjiang Tethys Metallogenic Belt (STMB), is the typical Ag-Pb-Zn-Cu deposit in this region. Its orebodies are hosted in the Carboniferous Yiliu Formation volcanic-sedimentary cycle and occur as stratiform, stratoid and lenticular. Whether or not the stratabound ore belong to the volcanogenic massive sulfide (VMS) deposit remains unclear and controversial. In this paper, the whole rock geochemistry, trace elements in sphalerite, U-Pb zircon chronology and Pb isotopes were investigated, aiming to provide significant insights into the genesis and geodynamic setting of the Laochang deposit. Lead isotope ratios of pyrite and sphalerite from the stratabound ore are 18.341 to 18.915 for 206Pb/204Pb; 15.376 to 15.770 for 207Pb/204Pb; and 38.159 to 39.200 for 208Pb/204Pb—which display a steep linear trend on Pb-Pb diagrams. This indicates a binary mixing of lead components derived from leaching between the host volcanic rock and mantle reservoir. Sphalerite from stratabound ores is relatively enriched in Fe, Mn, In, Sn, and Ga—similar to typical VMS deposits. Moreover, the Carboniferous volcanic rock hosting the stratabound Ag-Pb-Zn-Cu ores has a zircon U-Pb age of 312 ± 4 Ma; together with previous geochronological and geological evidences, thus, we consider that the stratabound mineralization occur in the Late Paleozoic (~323–308 Ma). Collectively, these geologic, geochemical, and isotopic data confirm that the stratabound ores should be assigned to Carboniferous VMS mineralization. In addition, volcanic rocks hosting the stratabound ore exhibit elevated high field strength elements (HFSEs, Nb, Ta, Zr and Hf) abundance, slight enrichment of light rare earth element (LREE), and depletion of Ba and Sr with obvious Nb-Ta anomalies. Such characteristics suggest that their magma is similar to typical oceanic island basalt. In addition, the oceanic island basalt (OIB)-like volcanic rocks were formed at Late Paleozoic, which could be approximately synchronous with the VMS mineralization at Laochang. Thus, it is suggested that the Laochang VMS mineralization was generated in the oceanic island setting prior to the initial subduction of the Changning-Menglian Paleo-Tethys Ocean.
11
Cannon, Aubrey. "Settlement and Sea-Levels on the Central Coast of British Columbia: Evidence from Shell Midden Cores." American Antiquity 65, no. 1 (January 2000): 67–77. http://dx.doi.org/10.2307/2694808.
Abstract:
AbstractCoring of shell-midden sites provides a regional chronology of site settlement in the Namu vicinity on the central coast of British Columbia. Coring proved an accurate and cost-effective alternative to traditional test-excavation, and its application in only two short field seasons doubled the number of sites tested in this region. The dating of basal cultural deposits from the cores shows initial occupation of sites ranging from 10,000 to 800 B.P. These dates exhibit a strong linear relationship with the current elevation of deposits above average high tide, suggesting that the settlement history of known shell-midden sites in this region is strongly linked to gradual long-term decline in relative sea levels.
12
Salieva, M., and Y. Tashpolotov. "Composites With Ceramic Matrix Reinforced With Inorganic and Organic Fillers." Bulletin of Science and Practice, no. 2 (February 15, 2023): 209–18. http://dx.doi.org/10.33619/2414-2948/87/25.
Abstract:
The subject of this article is the development of composite materials using ceramic matrices (CM) to increase their strength and reduce the density and brittleness of ceramics. The purpose of this work is to reveal the effect of the content, size, and shape of the introduced fillers on the CM structure, which determines the behavior of CMs. The methods and materials of the study, the analysis of literary sources, as well as the results of the obtained data are considered. For the development of composite materials, we used the loams of the Tyuleikenskoye deposit of the Southern Kyrgyzstan and finely ground basalt powder with organic humate. In addition, we added basalt fibers as an additive. When adding 3-10% of basalt powder to the composition of the clay mass, fire shrinkage decreases slightly. In this limit of additives, the mineralizing effect of the chemical elements of basalt powder and humate on the formation of shards is most effective. With a further increase for additives to 15%, there is an insignificant linear thermal expansion of the samples, which is caused by the phase composition of the shard. At the same time, the optimal firing temperature of raw materials with a content of 3-15% of its additive is 950-1050 °C, within which the main processes of structure formation take place. According to the results of the experiment, the maximum strength of the samples at 1000°C was 15.8-18.8 MPa with the addition of 5% additive, and with an increase in basalt powder and fiber to 15%, the strength was 16.3 MPa. Based on the results obtained, it is possible to use basalt powder and basalt fiber with the addition of humate as the main component in the production of composite ceramic products.
13
Baghdad, Abdelmalek, Rekia Bouazi, Youcef Bouftouha, Frédéric Hatert, and Nathalie Fagel. "Characteristics and firing behaviour of the under-Numidian clay deposits from the Jijel region (northeast Algeria): potential use in the ceramics industry." Clay Minerals 54, no. 4 (November 15, 2019): 325–37. http://dx.doi.org/10.1180/clm.2019.51.
Abstract:
AbstractThe Numidian Aquitano-Burdigalian nappe from the Jijel region (northeast Algeria) shows an important clay-rich basal series. In this study, seven representative clay samples were collected from the Djimla and El-Milia areas of this region in order to analyse their mineralogy using X-ray diffraction and Fourier-transform infrared spectroscopy, chemical composition by X-ray fluorescence, particle size, plasticity, morphology by scanning electron microscopy and their ceramic properties. Samples were prepared by pressing the clays and firing them at 800–1100°C, and bulk density, water absorption, linear firing shrinkage, weight loss and bending strength values were determined on the fired samples. The clays are mainly composed of kaolinite and illite, with a small amount of 10–14 Å interstratified clay minerals and chlorite, associated with quartz and feldspars. The main oxides in the samples were SiO2, Al2O3 and Fe2O3. The clays may be classified as moderately plastic according to their Atterberg limits. Ceramic tiles have been produced by dry pressing. At all tested firing temperatures, the clays present the required standard values for linear firing shrinkage, weight loss, bulk density, water absorption and bending strength, and they are defect-free. The main transformations were observed at 1000°C with the appearance of new crystalline phases. The measured technological properties of the investigated deposits confirm that the Numidian clays from the Djimla and El-Milia regions are suitable materials for the production of high-quality structural ceramics.
14
Jovicich, Elio, and Daniel J. Cantliffe. "Salts Deposited on the Lower Stem of Bell Pepper Contribute to a Basal Stem Disorder in Soilless, Greenhouse-grown Plants." HortScience 39, no. 1 (February 2004): 36–39. http://dx.doi.org/10.21273/hortsci.39.1.36.
Abstract:
A physiological disorder in greenhouse-grown pepper (Capsicum annuum L.) plants was observed in Florida, wherein the base of the main stem becomes swollen below the cotyledonary node level and crack-like wounds develop at the base of the stem's epidermis. The disorder may predispose the plant to a localized rot and result in a sudden plant wilt. The effects of soilless media type, transplant depth, and amount of nutrient solution applied per day were studied to evaluate the development of what was termed “Elephant's Foot” disorder, on a greenhouse-grown bell pepper crop in Gainesville, Fla. The percentage of plants with epidermal wounds at the base of the stem was highest (83%) on plants transplanted at half of the cell height (3.8 cm), compared to plants transplanted to the cotyledonary node level (6%) and the second leaf node (0%). Salts were washed from the surface of basal stem epidermis and electrical conductivity measured in the washing solution was expressed per unit area of epidermal sample (ECA). The ECA in the solutions from plants transplanted at half of the cell height was higher than that from plants transplanted to the cotyledonary node level and to the second leaf node. There was a positive linear relationship (r = 0.81) between the percentage of plants with epidermal wounds and the ECA of the solution obtained from washing the epidermal tissues. Salts deposited on the epidermis beneath the cotyledonary node provoked a tissue injury that may predispose the plant to a Fusarium infection. Simple management practices, such as transplanting deep, using cultivars with lower susceptibility to salt damage, and gradually moving back the emitter from the base of the plant after transplanting (to reduce humid conditions near the base of the stem) would help reduce the appearance of this basal stem disorder in soilless-grown peppers.
15
Nigai, E. V. "ON THE GOLD MINERALIZATION IN WEATHERING CRUSTS OF THE RYBACHY SITE (WESTERN SIKHOTE-ALIN)." REGIONAL PROBLEM 24, no. 1 (2021): 26–33. http://dx.doi.org/10.31433/2618-9593-2021-24-1-26-33.
Abstract:
The author addresses an issue of gold presence in pre-Quaternary crusts of weathering that are widespread in sub-mountain areas of the doming-block geomorphological structures of the Amur Region, the Khabarovsk and Primorsky Territories along the periphery of large- and medium-sized Cenozoic basins and depressions. For a more detailed mining and geological study and assessment of the gold content of the weathering crusts, we recommended the Rybachy site as one of these objects (insufficiently studied), and the entire Mukhenskaya area as a promising one. These sites are located in the zone of articulation of the eastern side of the Middle Amur Depression with the folded structures of the West Sikhote-Alinsky volcanic belt. The author gives examples of large gold deposits, related to weathering crusts with their brief description (Olympiada, Kuranakh), as well as a brief description of alluvial deposits of weathering crust (sub-basalt cl.Paskhalny, an eluvial-alluvial placer of the Bolotisty Stream). The search work of the DVIMS (Far Eastern Institute of Mineral Raw Materials) in 2002 indicated the potential of weathering crusts within the Rybachy prospect for gold mineralization. This is supported by elevated gold in heavy mineral concentrates from the linear weathering crusts and residual blankets, as well as from non-commercial placers (from 0.01 to 4.0 g/t and higher); the occurrence of fracture zones, brecciation, secondary silicification close by fractures, and abundant Late Cretaceous silicic and intermediate dikes. Zones of hydrothermally altered rocks (silicification, chloritization, sericitization, argillization) are widespread here.
16
Sullivan, B. J., G. S. Baxter, and A. T. Lisle. "Low-density koala (Phascolarctos cinereus) populations in the mulgalands of south-west Queensland. I. Faecal pellet sampling protocol." Wildlife Research 29, no. 5 (2002): 455. http://dx.doi.org/10.1071/wr00110.
Abstract:
Koala (Phascolarctos cinereus) populations in eastern Australia are threatened by land clearing for agricultural and urban development. At the same time, conservation efforts are hindered by a dearth of information about inland populations. Faecal deposits offer a source of information that is readily available and easily collected non-invasively. We detail a faecal pellet sampling protocol that was developed for use in a large rangeland biogeographic region. The method samples trees in belt transects, uses a thorough search at the tree base to quickly identify trees with koala pellets under them, then estimates the abundance of faecal pellets under those trees using 1-m2 quadrats. There was a strong linear relationship between these estimates and a complete enumeration of pellet abundance under the same trees. We evaluated the accuracy of our method in detecting trees where pellets were present by means of a misclassification index that was weighed more heavily for missed trees that had high numbers of pellets under them. This showed acceptable accuracy in all landforms except riverine, where some trees with large numbers of pellets were missed. Here, accuracy in detecting pellet presence was improved by sampling with quadrats, rather than basal searches. Finally, we developed a method to reliably age pellets and demonstrate how this protocol could be used with the faecal-standing-crop method to derive a regional estimate of absolute koala abundance.
17
Abu Samah, Mohamad Ezanie, Che Aziz Ali, and Kamal Roslan Mohamed. "Sedimentological And Stratigraphical Analysis Of Kaki Bukit Formation (Lower Setul Member) At Teluk Ewa, Pulau Langkawi." Bulletin Of The Geological Society Of Malaysia 72 (November 15, 2021): 25–35. http://dx.doi.org/10.7186/bgsm72202103.
Abstract:
The identification of new units on the carbonate sequence of Teluk Ewa (from Tg. Mendidih to Teluk Ewa) has given an idea for the review of stratigraphic succession of Kaki Bukit Formation (Lower Setul Member). The analysis is related to a sedimentology study, where the sedimentary sequences formed as a mixed siliciclastic–carbonate shallow marine system that combines the carbonate and silisiclastic deposits. Eight facies have been recognised such as (1) argillite facies, (2) interlayer of mudstone and limestone facies, (3) wavy stromatolites limestone facies, (4) linear stromatolites limestone facies, (5) heterolithic of mudstone-limestone facies, (6) shale facies, (7) massive limestone facies and (8) thrombolites limestone facies. Each facies are divided into four litostratigraphic units based on the evaluation from Malaysian Stratigraphic Nomenclature Committee (1997) and North American Stratigraphic Code 2005. (1) The clastic unit referring to the uppertmost part of Machinchang Formation maintains it's name. Meanwhile, the suggested nomenclature for the new units such as (2) The Sabung Member is referring to the basal carbonate unit comprising microbial facies and mixed silisiclastic-carbonate sediment. (3) The Pesak Seluar Member in the middle is a silisiclastic unit that consists of shale facies and (4) The Ewa Member at the top representing the upper limestone unit. All units show a similar litostratigraphic characteristics that are found in Tarutao Group, Pante Malaka Formation, Rung Nok Formation and Lae Tong Formation in Thailand as described by Wongwanich et al. (1990; 2002) and Imsamut & Abdul Rahman (2017).
18
Priddy, Charlotte, Amy Regis, Stuart Clarke, A. Leslie, and Thomas Dodd. "Localized bank collapse or regional event?" Geology of the Intermountain West 8 (December 17, 2021): 27–44. http://dx.doi.org/10.31711/giw.v8.pp27-44.
Abstract:
This study presents a detailed synopsis of the sedimentological and structural features displayed within an underdescribed enigmatic facies observed in the basal Lower Jurassic Kayenta Formation of the Colorado Plateau. The facies comprises pebble to cobble-sized clasts of fine to medium-grained crossbedded sandstone with mud-draped and deformed foresets, as well as clasts of parallel-laminated but highly contorted siltstone and mudstone, supported in a silty to sandy matrix. The deposits are internally deformed and show both ductile and brittle structures in close spatial proximity, with a consistent and pervasive westdirected sense of shear. The facies occurs consistently within the same approximate stratigraphic interval, at or near the base of the Kayenta Formation. It is, however, observed only at four localities, distributed in a crudely linear arrangement parallel to the Utah-Idaho trough, despite extensive studies of outcrops of the same stratigraphic interval widely distributed across both Utah and Arizona. This study interprets the depositional processes as that of a partially subaerial debris flow with depositional events perhaps taking place during the waning period after ephemeral stream activity. The clast morphology and composition suggests a local source for the sediment entrained within the flow, and a limited transport distance. All of these observations are difficult to reconcile with the consistency of the stratigraphic interval in which the facies occur, or with the regional distribution of preserved examples. Consequently, this study discusses the potential for a common and time-equivalent triggering mechanism across all examples, which may have regional significance in the Jurassic evolution of the region.
19
Kamayeva, О. I., and V. V. Sura. "On the contribution of immune 42 mechanisms to the pathogenesis of diabetic nephropathy." Problems of Endocrinology 42, no. 5 (October 15, 1996): 42–47. http://dx.doi.org/10.14341/probl12092.
Abstract:
Diabetic nephropathy (NF) came first among all the specified causes of end-stage renal failure. Patients with type 1 diabetes mellitus (DM) make up more than half of all patients treated with chronic hemodialysis in the United States and Western Europe. Among patients with diabetes with terminal renal failure, 60% are people over 50 years old, so hemodialysis is not always prescribed. However, hemodialysis is increasingly used in elderly and senile patients; therefore, the proportion of patients with diabetes, especially type II diabetes, in hemodialysis centers will increase, significantly increasing the cost of treating diabetes. Currently, along with metabolic, hemodynamic and genetic theories, the role of immune disorders in the formation and progression of DNs is being discussed. The prerequisites for the formation of a hypothesis about the immune genesis of DNs were the frequent detection of increased levels of circulating immune complexes (CICs) and immunoglobulins in the blood, as well as deposits of immunoglobulins and complement in the kidney structures of patients with diabetes. However, among researchers there is no unanimity in the explanation of these facts. Many consider indisputably existing immune abnormalities inherent in DN as non-specific epiphenomes. The immune hypothesis of the pathogenesis of DN was formulated back in the 70s. The currently accumulated data suggest the participation of the immunocomplex mechanism in the development of DN. Immunofluorescence examination of the kidney tissue of patients with diabetes almost always reveals a luminescence of IgG, IgM, less often IgA, SZ and other complement fractions along the basal membranes of the glomeruli (BMC) and tubules of focal granular and linear in nature.
20
Sabatier, P., J. L. Reyss, J. M. Hall-Spencer, C. Colin, N. Frank, N. Tisnérat-Laborde, L. Bordier, and E. Douville. "<sup>210</sup>Pb-<sup>226</sup>Ra chronology reveals rapid growth rate of <i>Madrepora oculata</I> and <i>Lophelia pertusa</i> on world's largest cold-water coral reef." Biogeosciences Discussions 8, no. 6 (December 21, 2011): 12247–83. http://dx.doi.org/10.5194/bgd-8-12247-2011.
Abstract:
Abstract. Here we show the use of the 210Pb-226Ra excess method to determine the growth rate of corals from one of the world's largest known cold-water coral reef, the Røst Reef off Norway. Two large branching framework-forming cold-water coral specimens, one Lophelia pertusa and one Madrepora oculata were collected alive at 350 m water depth from the Røst Reef at ~67° N and ~9° E. Pb and Ra isotopes were measured along the major growth axis of both specimens using low level alpha and gamma spectrometry and the corals trace element compositions were studied using ICP-QMS. Due to the different chemical behaviors of Pb and Ra in the marine environment, 210Pb and 226Ra were not incorporated the same way into the aragonite skeleton of those two cold-water corals. Thus to assess of the growth rates of both specimens we have here taken in consideration the exponential decrease of initially incorporated 210Pb as well as the ingrowth of 210Pb from the decay of 226Ra. Moreover a~post-depositional 210Pb incorporation is found in relation to the Mn-Fe coatings that could not be entirely removed from the oldest parts of the skeletons. The 226Ra activities in both corals were fairly constant, then assuming constant uptake of 210Pb through time the 210Pb-226Ra chronology can be applied to calculate linear growth rate. The 45.5 cm long branch of M. oculata reveals an age of 31 yr and a~linear growth rate of 14.4 ± 1.1 mm yr−1, i.e. 2.6 polyps per year. However, a correction regarding a remaining post-depositional Mn-Fe oxide coating is needed for the base of the specimen. The corrected age tend to confirm the radiocarbon derived basal age of 40 yr (using 14C bomb peak) with a mean growth rate of 2 polyps yr−1. This rate is similar to the one obtained in Aquaria experiments under optimal growth conditions. For the 80 cm-long specimen of L. pertusa a remaining contamination of metal-oxides is observed for the middle and basal part of the coral skeleton, inhibiting similar accurate age and growth rate estimates. However, the youngest branch was free of Mn enrichment and this 15 cm section reveals a growth rate of 8 mm yr−1 (~1 polyp every two to three years). However, the 210Pb growth rate estimate is within the lowermost ranges of previous growth rate estimates and may thus reflect that the coral was not developing at optimal growth conditions. Overall, 210Pb-226Ra dating can be successfully applied to determine the age and growth rate of framework-forming cold-water corals, however, removal of post-depositional Mn-Fe oxide deposits is a prerequisite. If successful, large branching M. oculata and L. pertusa coral skeletons provide unique oceanographic archive for studies of intermediate water environmentals with an up to annual time resolution and spanning over many decades.
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Xu, Luyuan, and Le Qiao. "Formation age of the Rima Sharp sinuous rill on the Moon, source of the returned Chang’e-5 samples." Astronomy & Astrophysics 657 (January 2022): A42. http://dx.doi.org/10.1051/0004-6361/202142092.
Abstract:
Context. In December 2020, China’s Chang’e-5 spacecraft successfully returned 1731 g of lunar samples to Earth. Rima Sharp, one of the longest sinuous rilles on the Moon, lies very near (<20 km) to the Chang’e-5 sampling site and is very likely to be the source of the returned samples. Constraining its formation age would provide key references for the ongoing sample analyses. Aims. Our intent is to obtain the accurate formation ages of Rima Sharp and related lunar rilles through crater population studies and to assess their implications for the Chang’e-5 sample analyses and interpretations. Methods. We utilized two separate techniques to measure and analyze craters that were formed after the formation of the studied sinuous rilles: the conventional crater statistics for the rille floors and the buffered crater statistics that are specialized in the dating of narrow linear features. We were able to carefully compare the results derived from the two methods and estimate the formation ages of these rilles. Results. We suggest that the buffered crater statistic method produces more reliable ages for the studies rilles than the conventional method. The formation sequence of sinuous rilles around the Chang’e-5 site is proposed as follows, in chronological order: Rimae Harpalus, Louville, Sharp, and Mairan. The basalt samples returned by Chang’e-5 are likely to have mainly been sourced from Rima Sharp, with an estimated age of ~1.7 Ga based on the crater N(1) value (spatial density of craters ±1 km in diameter) of (2.10 ± 0.20) × 10−3 km−2 and the new crater chronology function (CF). The other, younger rille, Rima Mairan, which was formed ~1.0 Ga (N(1) = (1.17 ± 0.20) × 10−3 km−2 and with the same CF), may also contribute to the basaltic deposits at the landing site. These crater count statistics and dating results can be coordinated with the radio-isotopic age of Chang’e-5 samples for a recalibration of lunar impact flux and the crater population dating method.
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Wells, Ray E., Richard J. Blakely, and Sean Bemis. "Northward migration of the Oregon forearc on the Gales Creek fault." Geosphere 16, no. 2 (February 6, 2020): 660–84. http://dx.doi.org/10.1130/ges02177.1.
Abstract:
Abstract The Gales Creek fault (GCF) is a 60-km-long, northwest-striking dextral fault system (west of Portland, Oregon) that accommodates northward motion and uplift of the Oregon Coast Range. New geologic mapping and geophysical models confirm inferred offsets from earlier geophysical surveys and document ∼12 km of right-lateral offset of a basement high in Eocene Siletz River Volcanics since ca. 35 Ma and ∼8.8 km of right-lateral separation of Miocene Columbia River Basalt at Newberg, Oregon, since 15 Ma (∼0.62 ± 0.12 mm/yr, average long-term rate). Relative uplift of Eocene Coast Range basalt basement west of the fault zone is at least 5 km based on depth to basement under the Tualatin Basin from a recent inversion of gravity data. West of the city of Forest Grove, the fault consists of two subparallel strands ∼7 km apart. The westernmost, Parsons Creek strand, forms a linear valley southward to Henry Hagg Lake, where it continues southward to Newberg as a series of en echelon strands forming both extensional and compressive step-overs. Compressive step-overs in the GCF occur at intersections with ESE-striking sinistral faults crossing the Coast Range, suggesting the GCF is the eastern boundary of an R′ Riedel shear domain that could accommodate up to half of the ∼45° of post–40 Ma clockwise rotation of the Coast Range documented by paleomagnetic studies. Gravity and magnetic anomalies suggest the western strands of the GCF extend southward beneath Newberg into the Northern Willamette Valley, where colinear magnetic anomalies have been correlated with the Mount Angel fault, the proposed source of the 1993 M 5.7 Scotts Mills earthquake. The potential-field data and water-well data also indicate the eastern, Gales Creek strand of the fault may link to the NNW-striking Canby fault through the E-W Beaverton fault to form a 30-km-wide compressive step-over along the south side of the Tualatin Basin. LiDAR data reveal right-lateral stream offsets of as much as 1.5 km, shutter ridges, and other youthful geomorphic features for 60 km along the geophysical and geologic trace of the GCF north of Newberg, Oregon. Paleoseismic trenches document Eocene bedrock thrust over 250 ka surficial deposits along a reverse splay of the fault system near Yamhill, Oregon, and Holocene motion has been recently documented on the GCF along Scoggins Creek and Parsons Creek. The GCF could produce earthquakes in excess of Mw 7, if the entire 60 km segment ruptured in one earthquake. The apparent subsurface links of the GCF to other faults in the Northern Willamette Valley suggest that other faults in the system may also be active.
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Sabatier, P., J. L. Reyss, J. M. Hall-Spencer, C. Colin, N. Frank, N. Tisnérat-Laborde, L. Bordier, and E. Douville. "<sup>210</sup>Pb-<sup>226</sup>Ra chronology reveals rapid growth rate of <i>Madrepora oculata</i> and <i>Lophelia pertusa</i> on world's largest cold-water coral reef." Biogeosciences 9, no. 3 (March 30, 2012): 1253–65. http://dx.doi.org/10.5194/bg-9-1253-2012.
Abstract:
Abstract. Here we show the use of the 210Pb-226Ra excess method to determine the growth rate of two corals from the world's largest known cold-water coral reef, Røst Reef, north of the Arctic circle off Norway. Colonies of each of the two species that build the reef, Lophelia pertusa and Madrepora oculata, were collected alive at 350 m depth using a submersible. Pb and Ra isotopes were measured along the major growth axis of both specimens using low level alpha and gamma spectrometry and trace element compositions were studied. 210Pb and 226Ra differ in the way they are incorporated into coral skeletons. Hence, to assess growth rates, we considered the exponential decrease of initially incorporated 210Pb, as well as the increase in 210Pb from the decay of 226Ra and contamination with 210Pb associated with Mn-Fe coatings that we were unable to remove completely from the oldest parts of the skeletons. 226Ra activity was similar in both coral species, so, assuming constant uptake of 210Pb through time, we used the 210Pb-226Ra chronology to calculate growth rates. The 45.5 cm long branch of M. oculata was 31 yr with an average linear growth rate of 14.4 ± 1.1 mm yr−1 (2.6 polyps per year). Despite cleaning, a correction for Mn-Fe oxide contamination was required for the oldest part of the colony; this correction corroborated our radiocarbon date of 40 yr and a mean growth rate of 2 polyps yr−1. This rate is similar to the one obtained in aquarium experiments under optimal growth conditions. For the 80 cm-long L. pertusa colony, metal-oxide contamination remained in both the middle and basal part of the coral skeleton despite cleaning, inhibiting similar age and growth rate estimates. The youngest part of the colony was free of metal oxides and this 15 cm section had an estimated a growth rate of 8 mm yr−1, with high uncertainty (~1 polyp every two to three years). We are less certain of this 210Pb growth rate estimate which is within the lowermost ranges of previous growth rate estimates. We show that 210Pb-226Ra dating can be successfully applied to determine the age and growth rate of framework-forming cold-water corals if Mn-Fe oxide deposits can be removed. Where metal oxides can be removed, large M. oculata and L. pertusa skeletons provide archives for studies of intermediate water masses with an up to annual time resolution and spanning over many decades.
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Fuentes-Porto, Alba, Carlos García-Ávila, and Efraín Marrero-Salas. "Casa del Samarín, una estación de grabados rupestres en deterioro. Documentación, análisis y diagnóstico en Los Llanos de Ifara, Granadilla, Tenerife." Virtual Archaeology Review 12, no. 24 (January 19, 2021): 99. http://dx.doi.org/10.4995/var.2021.13810.
Abstract:
<p class="VARAbstract"><strong>Extended Abstract:</strong></p><p class="VARAbstract">In the archaeology of the Canary Islands (Spain), there are many studies based on the usage of new technologies to contribute to the identification and description of rock art engravings through high-resolution digital models (<a href="file:///L:/PC%20Port%C3%A1til%20Poli/Mis%20documentos/VAR/En%20Curso/Revisi%C3%B3n/13810/13810-60985-2-CE_jll.docx#Mart%C3%ADn_2005">Martín, 2005</a>; <a href="file:///L:/PC%20Port%C3%A1til%20Poli/Mis%20documentos/VAR/En%20Curso/Revisi%C3%B3n/13810/13810-60985-2-CE_jll.docx#Mart%C3%ADn_2007">Martín, Velasco, González & Ramírez, 2007;</a> <a href="file:///L:/PC%20Port%C3%A1til%20Poli/Mis%20documentos/VAR/En%20Curso/Revisi%C3%B3n/13810/13810-60985-2-CE_jll.docx#Senen_2016">Senén & Cuenca, 2016</a>; <a href="file:///L:/PC%20Port%C3%A1til%20Poli/Mis%20documentos/VAR/En%20Curso/Revisi%C3%B3n/13810/13810-60985-2-CE_jll.docx#Navarro_2019">Navarro & Cancel, 2019</a>). This paper is supported by these documentation techniques and digital analysis in order to deepen into the characterization of the damaged rock art station Casa del Samarín (House of Samarín), or Tagoro del Rey, in Los Llanos de Ifara, south of the island of Tenerife (Figs. 1). Twenty-one panels conserved in situ were documented (Fig. 6). Geometric-linear, geometric with an oval and rectangular trend and figurative ones can be distinguished. The blocks <a title="" href="file:///L:/PC%20Port%C3%A1til%20Poli/Mis%20documentos/VAR/En%20Curso/Revisi%C3%B3n/13810/13810-60985-2-CE_jll.docx#_ftn1">[1]</a> that compose the engravings station belong to a rocky basalt outcrop, to which other free-standing blocks are attached, forming a circle. The shape that describes this set of blocks is defined as a "cabin" or circular-shaped structure.</p><p class="VARAbstract">This set of engravings, made on a basalt rocky outcrop with a planar factory, show a tendency to suffer from exfoliation and are affected by internal stresses. The intrinsic characteristics of this stone support, together with their exposure to anthropic actions and strong insolation, condition its fragility, with the risk of losing part of the representations that it houses. Given the threat posed by its gradual deterioration, we seek to ensure its digital preservation through precision three-dimensional (3D) records, the engravings inventory, the record of their conservation state and the understanding of the degradation processes that are affecting the outcrop. What has been explained will be addressed quarterly, to observe the evolution of any material changes every three months.</p><p class="VARAbstract">The registration work consisted of taking four photogrammetric surveys in eight months; the surveys were georeferenced by means of a centimetric Global Navigation Satellite System (GNSS) and a total station. Structure from Motion (SfM) technology enabled the researchers to generate high-precision 3D models in an affordable way, not only in terms of cost but also ease of use. Digital copies with Geographic Information System GIS technology were extracted from them, being exportable in shapefile format (Fig. 7).</p><p class="VARAbstract">As regards the documentation of existing pathologies, assuming standardized lexicon and classification criteria (<a href="file:///L:/PC%20Port%C3%A1til%20Poli/Mis%20documentos/VAR/En%20Curso/Revisi%C3%B3n/13810/13810-60985-2-CE_jll.docx#IPCE_2013">IPCE, 2013</a>), together with a rigorous information systematization, was key for achieving agile handling of the data collected and for facilitating monitoring tasks (Fig. 8). Damage maps were created for collecting the location and scope of the alterations. The complex volumetry of the outcrop and the varied orientation of the panels marked the need to resort to 3D editing so that all their faces could be properly registered (Fig. 10). This project was performed with a 3D design program, Blender®. </p><p class="VARAbstract">Thanks to an imaging analysis process, internal textures of 3D models also provided relevant graphic support for the pictographic content and the conservation state (Figs. 11 & 14). DStretch® (<a href="file:///L:/PC%20Port%C3%A1til%20Poli/Mis%20documentos/VAR/En%20Curso/Revisi%C3%B3n/13810/13810-60985-2-CE_jll.docx#Harman_2008">Harman, 2008</a>), a plugin implemented in the scientific image processing software ImageJTM, was used for this purpose. To conclude, researchers relied on CloudCompare (<a href="file:///L:/PC%20Port%C3%A1til%20Poli/Mis%20documentos/VAR/En%20Curso/Revisi%C3%B3n/13810/13810-60985-2-CE_jll.docx#Girardeau_2015">Girardeau-Montaut, 2015</a>), an advanced 3D data processing software, to tackle a morphometric analysis that allowed us to detect the appearance of formal changes along with the recorded sequences (Figs. 12 & 15). In this process, the distances between two records, taken after six months, were computed with the Cloud to Mesh (C2M) tool, based on the Chamfer distance algorithm (<a href="file:///L:/PC%20Port%C3%A1til%20Poli/Mis%20documentos/VAR/En%20Curso/Revisi%C3%B3n/13810/13810-60985-2-CE_jll.docx#Ruiz_2016">Ruiz et al., 2016: 120</a>).</p><p>Registration file cards and damage maps clearly highlighted the main conditions: material losses (shown in orange) and breaks (in green) have affected the outcrop in a generalized way. Furthermore, sedimentary deposits (blue) are concentrated in interstices; while lichen colonies (idem) do so in the least sun-exposed areas. The use of DStretch® highlighted modern excoriations of anthropogenic origin and contributed to distinguishing recent material losses from the older ones, already affected by an incipient patina. Finally, thanks to morphological analysis, a new detachment (Fig. 15b) and a generalized displacement of exempt elements (Figs. 12 & 15) were detected. These displacements indicate outstanding manipulation, which could lead to decontextualizations or new fragmentations.</p><p>Regarding the archaeological interpretation, macroscopic observation of exempt blocks located in the vicinity of the station and the zenith representation of the immediate environment from photogrammetry, have shown that they are forming a set of attached structures (Fig. 13). The site redefinition and the diagnosis of its very weakened defensive system show the need to intensify the archaeological study of this area, so emblematic for the archaeology of the south of Tenerife, in addition to establishing preventive conservation measures that can contribute to its stabilization.</p><p class="VARAbstract"> </p><div><hr align="left" size="1" width="33%" /><div><p><a title="" href="file:///L:/PC%20Port%C3%A1til%20Poli/Mis%20documentos/VAR/En%20Curso/Revisi%C3%B3n/13810/13810-60985-2-CE_jll.docx#_ftnref1">[1]</a> Geological unit of size greater than 300 mm, term standardized by the USCS (Unified Soil Classification System).</p></div></div>
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Miralles, Manuel, Manel Arrebola, Emma Plana, and Ignacio Sanchez-Nevarez. "Abstract 503: Osteoporosis and Aterial Calcification: Are These Processes Related?" Arteriosclerosis, Thrombosis, and Vascular Biology 35, suppl_1 (May 2015). http://dx.doi.org/10.1161/atvb.35.suppl_1.503.
Abstract:
The relationship between arterial calcification and osteoporosis has been referred to in several studies. However, its temporal relationship has scarcely been analyzed. Hypothesis: We assessed the hypothesis that temporal evolution of Ca content in the carotid bifurcation is related with densitometric variation in bone calcium mass, in order to assess the possible connection of both processes through the Ca/P metabolism. Patients and methods: Design: Prospective cohort study. Population : 32 asymptomatic patients with stenosis of the internal carotid artery (ICA)>50% (duplex scanningr). Determinations: Ca content (quantitative Angio-CT) in 3D reconstruction of the carotid bifurcation, basal and at 12+/-2 months. Bone densitometry of spine and femur, basal and 12+/-2 months, biochemistry and Ca-P metabolism (Ca, P, vit.D, PTH, OPG, OPG). Statistical analysis: Descriptive statistics, comparison of means (t-test), uni-and multivariate linear regression (Intraplaque Ca/ bone densitometry, Ca-P metabolism). Results: An increase of intraplaque Ca respect to baseline values (79.2 (55) vs 64.58 (49.2) mm 3 .xU.H., p = 0.12) and a significant decrease in bone mass respect to baseline determination (2.08 (0.22) vs 2.06 (0.23) g/cm 2 , p = 0.013) were observed. However, a positive correlation was identified between the relative variation of the Ca content and bone mass (r= 0.574, p= 0.003). In other words, a greater tendency to osteoporosis was associated with a reduced tendency to intraplaque calcium progression. In Addition, an inverse relationship between plasma levels of Vit D and basal densitometry (r= -0.459; p=0.036) were found. Only P concentration in urine showed a moderate positive correlation with increased intraplaque Ca (r = 0.488, p = 0.015). No other variable, was related to arterial calcification. Conclusions: As in other published series, an independent tendency to progressive arterialcalcification and bone decalcification was found in this study. However, these results suggest a direct temporal relation in calcium deposit evolution of both localizations, so it is not possible to rule out that their modulation is governed by similar activation and regulation mechanisms.
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Sandru, Florica, Mihai Dumitrascu, Daniel-Vasile Balaban, Razvan-Cosmin Petca, Adelina Popa, Elis Curtmola, and Raluca Gabriela Miulescu. "LINEAR IG A BULLOUS DERMATOSIS – CASE REPORT." Romanian Journal of Clinical Research 2, no. 2 (December 31, 2019). http://dx.doi.org/10.33695/rjcr.v2i2.30.
Abstract:
Linear IgA bullous dermatosis (LABD) is a rare, immune-mediated cutaneous pathology, characterized by IgA deposits along the basal membrane. Clinically, it manifests as an eruption, consisting of vesicles and bullae, with herpetiform distribution, on erythematous and/or normal skin. The lesions are located symmetrically, at the level of the trunk and extremities. Clinically, diagnosis can be difficult because it can be easily mistaken with dermatitis herpetiformis or bullous pemphigoid. We present the case of a 79-years-old woman, without significant comorbidities, who developed a vasculo-bullous eruption, intensely itchy, located symmetrically on trunk and extremities, evolving for 4 years. We performed a skin biopsy, with histopathological examination and direct immunofluorescence, which revealed: sub epidermal vesicular-bullous lesion and dermal infiltrate with numerous neutrophils and eosinophils; IgA - continuous linear positivity at the dermal-epidermal junction. Thus, the diagnosis of LABD was established. The treatment consisted of systemic corticosteroids, colchicine, and antihistamines, with favorable evolution. The management of these patients can be challenging, as LABD can be induced by certain drugs, and may also be associated with lymphoid malignancies.
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Alafaleq, Munirah, Juliette Knoeri, Sandrine Boutboul, and Vincent Borderie. "Contact lens induced bacterial keratitis in LCD II: Management and multimodal imaging: a case report and review of literature." European Journal of Ophthalmology, October 30, 2020, 112067212096872. http://dx.doi.org/10.1177/1120672120968724.
Abstract:
Purpose: To describe the management and multimodal imaging of lattice corneal dystrophy type II (LCD-II) complicated by an infectious keratitis due to a bandage contact lens and to review current literature. Observation: A 50-year-old female was diagnosed with Meretoja’s Syndrome by the triad of facial palsy, loose skin (cutix laxa), and stromal corneal dystrophy. At slit lamp, bilateral lattice corneal dystrophy (LCD) was characterized by multiple linear refractile lines and subepithelial fibrosis along with Neurotrophic keratitis Mackie grade I. Findings of anterior segment optical coherence tomography (AS-OCT) were epithelial irregularity, subepithelial fibrosis, hyperreflectivity on anterior stromal layer, lobulated stromal surface. In vivo confocal microscopy (IVCM) showed hyperreflected deposits on the basal and Bowman layers, visible keratocytes; fine lines and streaks between corneal lamella. The sub-basal nerve plexus and the stromal nerves were no longer visible. She presented in emergency with a left red eye. A severe bacterial keratitis was diagnosed as a complication of a bandage contact lens used to treat recurrent epithelial erosion. Corneal anesthesia was complete. Corneal neovascularization was evident 10 weeks later and topical bevacizumab (5 mg/ml) was introduced twice daily. Partial regression of deep stromal vessels was noticed at 3 months. Conclusion: In Meretoja’s syndrome, neurotrophic keratopathy secondary to polyneuropathy due to systemic amyloid deposits is present in the advanced stages, promotes recurrent corneal erosions. Corneal sensitivity test, AS-OCT and IVCM are crucial in the diagnosis behind any recurrent corneal erosion. The use of bandage contact lens should be avoided in Meretoja’s syndrome to prevent a possible infectious keratitis.
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Cai, Jiyang, Christopher Litwin, Rui Cheng, Jian-Xing Ma, and Yan Chen. "DARPP32, a target of hyperactive mTORC1 in the retinal pigment epithelium." Proceedings of the National Academy of Sciences 119, no. 33 (August 8, 2022). http://dx.doi.org/10.1073/pnas.2207489119.
Abstract:
The mechanistic target of rapamycin (mTOR) is assembled into signaling complexes of mTORC1 or mTORC2, and plays key roles in cell metabolism, stress response, and nutrient and growth factor sensing. Accumulating evidence from human and animal model studies has demonstrated a pathogenic role of hyperactive mTORC1 in age-related macular degeneration (AMD). The retinal pigment epithelium (RPE) is a primary injury site in AMD. In mouse models of RPE-specific deletion of Tuberous sclerosis 1 ( Tsc1 ), which encodes an upstream suppressor of mTORC1, the hyperactivated mTORC1 metabolically reprogrammed the RPE and led to the degeneration of the outer retina and choroid (CH). In the current study, we use single-cell RNA sequencing (scRNA-seq) to identify an RPE mTORC1 downstream protein, dopamine- and cyclic AMP-regulated phosphoprotein of molecular weight 32,000 (DARPP-32). DARPP-32 was not found in healthy RPE but localized to drusen and basal linear deposits in human AMD eyes. In animal models, overexpressing DARPP-32 by adeno-associated virus (AAV) led to abnormal RPE structure and function. The data indicate that DARPP-32 is a previously unidentified signaling protein subjected to mTORC1 regulation and may contribute to RPE degeneration in AMD.