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Kim, Kyungmin, und Minseok Song. „Energy-Saving SSD Cache Management for Video Servers with Heterogeneous HDDs“. Energies 15, Nr. 10 (16.05.2022): 3633. http://dx.doi.org/10.3390/en15103633.
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Dynamic adaptive streaming over HTTP (DASH) technique, the most popular streaming method, requires a large number of hard disk drives (HDDs) to store multiple bitrate versions of many videos, consuming significant energy. A solid-state drive (SSD) can be used to cache popular videos, thus reducing HDD energy consumption by allowing I/O requests to be handled by an SSD, but this requires effective HDD power management due to limited SSD bandwidth. We propose a new SSD cache management scheme to minimize the energy consumption of a video storage system with heterogeneous HDDs. We first present a technique that caches files with the aim of saving more HDD energy as a result of I/O processing on an SSD. Based on this, we propose a new HDD power management algorithm with the goal of increasing the number of HDDs operated in low-power mode while reflecting the heterogeneous HDD power characteristics. For this purpose, it assigns a separate parameter value to each I/O task based on the ratio of HDD energy to bandwidth and greedily selects the I/O tasks handled by the SSD within limits on its bandwidth. Simulation results show that our scheme consumes between 12% and 25% less power than alternative schemes under the same HDD configuration.
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Wang, Shucheng, Ziyi Lu, Qiang Cao, Hong Jiang, Jie Yao, Yuanyuan Dong, Puyuan Yang und Changsheng Xie. „Exploration and Exploitation for Buffer-Controlled HDD-Writes for SSD-HDD Hybrid Storage Server“. ACM Transactions on Storage 18, Nr. 1 (28.02.2022): 1–29. http://dx.doi.org/10.1145/3465410.
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Hybrid storage servers combining solid-state drives (SSDs) and hard-drive disks (HDDs) provide cost-effectiveness and μs-level responsiveness for applications. However, observations from cloud storage system Pangu manifest that HDDs are often underutilized while SSDs are overused, especially under intensive writes. It leads to fast wear-out and high tail latency to SSDs. On the other hand, our experimental study reveals that a series of sequential and continuous writes to HDDs exhibit a periodic, staircase-shaped pattern of write latency, i.e., low (e.g., 35 μs), middle (e.g., 55 μs), and high latency (e.g., 12 ms), resulting from buffered writes within HDD’s controller. It inspires us to explore and exploit the potential μs-level IO delay of HDDs to absorb excessive SSD writes without performance degradation. We first build an HDD writing model for describing the staircase behavior and design a profiling process to initialize and dynamically recalibrate the model parameters. Then, we propose a Buffer-Controlled Write approach (BCW) to proactively control buffered writes so that low- and mid-latency periods are scheduled with application data and high-latency periods are filled with padded data. Leveraging BCW, we design a mixed IO scheduler (MIOS) to adaptively steer incoming data to SSDs and HDDs. A multi-HDD scheduling is further designed to minimize HDD-write latency. We perform extensive evaluations under production workloads and benchmarks. The results show that MIOS removes up to 93% amount of data written to SSDs, reduces average and 99 th -percentile latencies of the hybrid server by 65% and 85%, respectively.
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Karagiannidis, Athanasios, Konstantinos Lagouvardos, Vassiliki Kotroni und Elisavet Galanaki. „Expected Changes in Heating and Cooling Degree Days over Greece in the near Future Based on Climate Scenarios Projections“. Atmosphere 15, Nr. 4 (22.03.2024): 393. http://dx.doi.org/10.3390/atmos15040393.
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The change in heating and cooling needs of Greece in the near future due to the climate change is assessed in the present study. Global and regional climate models and two different representative concentration pathways (RCPs) are used to simulate the expected change in temperature. A widely used methodology of computation of heating degree days (HDDs) and cooling degree days (CDDs) is employed with a base temperature of 18 °C. In agreement with the expected temperature rise in the near future, an HDD decrease and CDD increase under both RCPs is also expected. The changes under RCP8.5 are stronger compared to those under RCP4.5. Differences related to topography are noted. The HDD decrease is stronger than CDD increase but the relative increase in CDDs is higher than the relative increase in HDDs. The highest absolute decreases in HDDs are expected for February and March while the highest absolute increases in CDDs are expected during the three summer months.
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Andrade, Cristina, Sandra Mourato und João Ramos. „Heating and Cooling Degree-Days Climate Change Projections for Portugal“. Atmosphere 12, Nr. 6 (01.06.2021): 715. http://dx.doi.org/10.3390/atmos12060715.
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Climate change is expected to influence cooling and heating energy demand of residential buildings and affect overall thermal comfort. Towards this end, the heating (HDD) and cooling (CDD) degree-days along with HDD + CDD were computed from an ensemble of seven high-resolution bias-corrected simulations attained from EURO-CORDEX under two Representative Concentration Pathways (RCP4.5 and RCP8.5). These three indicators were analyzed for 1971–2000 (from E-OBS) and 2011–2040, and 2041–2070, under both RCPs. Results predict a decrease in HDDs most significant under RCP8.5. Conversely, it is projected an increase of CDD values for both scenarios. The decrease in HDDs is projected to be higher than the increase in CDDs hinting to an increase in the energy demand to cool internal environments in Portugal. Statistically significant linear CDD trends were only found for 2041–2070 under RCP4.5. Towards 2070, higher(lower) CDD (HDD and HDD + CDD) anomaly amplitudes are depicted, mainly under RCP8.5. Within the five NUTS II regions projections revealed for 2041–2070 a decrease in heating requirements for Algarve and Lisbon Area higher in Faro, Lisboa and Setúbal whereas for North and Center regions results predicts an increase in cooling energy demand mainly in Bragança, Vila Real, Braga, Viana do Castelo, Porto and Guarda, higher under RCP8.5.
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Edgell, Dennis J. „Spline Plotting Method to Visualize Climate Change of Heating and Cooling Degree-Days in North Carolina“. Journal of the North Carolina Academy of Science 138, Nr. 1 (01.01.2022): 8–18. http://dx.doi.org/10.7572/jncas-d-23-00002.1.
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Abstract Degree-days are variables utilized for the planning, estimation and assessment of heating requirements and cooling demands of building interiors. Heating Degree-Days (HDD) are the number of degrees that a day's mean temperature is below 65° Fahrenheit (18° Celsius). Cooling Degree-Days (CDD) are the number of degrees that a day's mean temperature is above 65° Fahrenheit (18° Celsius). Long and short term climate changes have the potential to change heating and cooling. Original data were NOAA Climate Division areal averages for monthly total HDD and monthly total CDD. Raw data were downloaded from a NOAA online database. Univariate statistics for all eight North Carolina climate divisions were calculated. The time series of annual total HDDs and CDDs is complete from 1895 to 2017. A spline routine was fit through the series in order to best visualize trends. Results indicate that annual total HDD and CDD have changed over time, but the time series relationships are not linear. The most recent decades show that annual CDDs are rapidly increasing, while HDDs steadily decline. Energy demands for summer cooling will not be offset by decreased energy demands in winter.
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Hredzak, B., und G. Guo. „New passive balancing algorithm for high-density hard disk drives“. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 218, Nr. 4 (01.04.2004): 401–10. http://dx.doi.org/10.1177/095440620421800405.
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One of the major sources of vibrations in hard disk drives (HDDs) is unbalance caused by an uneven distribution of the mass on the rotational part of the HDD. Vibrations are limiting the increase in the storage density of the HDDs; therefore it is of paramount importance to identify major sources of vibrations and to reduce them to the minimum level. This paper proposes a new passive balancing algorithm which can achieve significant reduction in the HDD unbalance at low cost and with a high yield rate. The unbalance reduction is achieved using a balancing ring with a large number of holes which are used for the placement of balancing masses of a given weight. The optimum number and position of the balancing masses is then found in order to reduce the residual unbalance to minimum level. Guidelines on optimum selection of the correction mass are also proposed.
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Wasala, Sahan, Yutong Xue, Lon Stevens, Ted Wiegandt und Tim Persoons. „Numerical simulations of flow induced noise from a dual rotor cooling fan used in electronic cooling systems“. INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, Nr. 5 (01.08.2021): 1308–19. http://dx.doi.org/10.3397/in-2021-1809.
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Hard Disk Drive (HDD) system enclosures in a data center require effective cooling systems to avoid HDD overheating. These systems often rely on air cooling because of their cost effciency and maintainability. Air cooling systems typically consist of an array of axial fans which push or pull the air through the system. These fans emit high level tonal noise particularly at high tip speed ratios. High-capacity HDDs, on the other hand, are sensitive to high acoustic noise, which consequently increases the risk of read/write error and deteriorates drive performance. Therefore, cooling fan noise adversely affects the function of the HDD enclosure systems which emphasizes the need to understand the noise sources and develop methods to mitigate HDD noise exposure.
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Atsumi, Takenori. „Head-Positioning Control of Hard Disk Drives Through the Integrated Design of Mechanical and Control Systems“. International Journal of Automation Technology 3, Nr. 3 (05.05.2009): 277–85. http://dx.doi.org/10.20965/ijat.2009.p0277.
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A Hard Disk Drive (HDD) is an inexpensive mass-production product, but the head-positioning control systems of HDDs require nanometer-scale positioning performance. Therefore, we have studied head-positioning control systems of HDD using designs which integrate mechanical and control systems to improve their control performance while curbing cost increases. In this paper, we introduce “disturbance suppression in high-frequency ranges through phase stable design for high-order mechanical resonances” and “high servo-bandwidth design through mode shape design of mechanical resonance” as examples of techniques that have been developed and are easily applied to products.
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Tzeng, H. „Characteristics of Particle Deposition on Disks in Disk Drives“. Journal of the IEST 37, Nr. 2 (01.03.1994): 34–39. http://dx.doi.org/10.17764/jiet.2.37.2.e80828272442j127.
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The characteristics of particle deposition on disk surfaces in hard disk drives (HDDs) was studied. The density of tracer particles deposited on the disks was measured to determine the deposition profile. The circumferentially averaged deposition density increases monotonically with radius. The number of deposited particles on the two outermost disk surfaces is more than twice that on other disk surfaces in the HDD. An obstruction to the flow unequally enhances the particle deposition on the disk: 15 percent to the two outermost surfaces, and 55 percent to the other surfaces. These features can be explained satisfactorily by the airflow characteristics in the HDD.
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Watts, Liam, Julien Walzberg, Alberta Carpenter und Garvin A. Heath. „Exploring Secondary Markets to Improve Circularity: A comparative case study of photovoltaics and hard-disk drives“. IOP Conference Series: Materials Science and Engineering 1196, Nr. 1 (01.10.2021): 012029. http://dx.doi.org/10.1088/1757-899x/1196/1/012029.
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Abstract Each year renewable energy generation increases notably with solar panel installations, but these panels have a limited lifespan and will produce between 2 and 4 million metric tons of waste by 2040. Similarly, there are currently between 20 to 70 million hard-disk drives (HDDs) reaching end-of-life (EOL) annually. The circular economy (CE) strives to recycle and reuse materials that are rare and expensive to obtain, minimizing waste. However, studying the potential circularity of photovoltaics (PV) and HDDs requires various data, for instance, on the maturity of the secondhand markets. In this context, the objective of the present study is to identify the current state of secondhand PV and HDD markets. After conducting a literature review, an automated data collection process was set up for that purpose. The analysis of the literature and collected data assess the maturity of the secondhand PV modules and HDDs markets and highlight differences between them.
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Marfatia, S. M., J. H. Morais Cabral, L. Lin, C. Hough, P. J. Bryant, L. Stolz und A. H. Chishti. „Modular organization of the PDZ domains in the human discs-large protein suggests a mechanism for coupling PDZ domain-binding proteins to ATP and the membrane cytoskeleton.“ Journal of Cell Biology 135, Nr. 3 (01.11.1996): 753–66. http://dx.doi.org/10.1083/jcb.135.3.753.
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The human homologue (hDIg) of the Drosophila discs-large tumor suppressor (DIg) is a multidomain protein consisting of a carboxyl-terminal guanylate kinase-like domain, an SH3 domain, and three slightly divergent copies of the PDZ (DHR/GLGF) domain. Here have examined the structural organization of the three PDZ domains of hDIg using a combination of protease digestion and in vitro binding measurements. Our results show that the PDZ domains are organized into two conformationally stable modules one (PDZ, consisting of PDZ domains 1 and 2, and the other (PDZ) corresponding to the third PDZ domain. Using amino acid sequencing and mass spectrometry, we determined the boundaries of the PDZ domains after digestion with endoproteinase Asp-N, trypsin, and alpha-chymotrypsin. The purified PDZ1+2, but not the PDZ3 domain, contains a high affinity binding site for the cytoplasmic domain of Shaker-type K+ channels. Similarly, we demonstrate that the PDZ1+2 domain can also specifically bind to ATP. Furthermore, we provide evidence for an in vivo interaction between hDIg and protein 4.1 and show that the hDIg protein contains a single high affinity protein 4.1-binding site that is not located within the PDZ domains. The results suggest a mechanism by which PDZ domain-binding proteins may be coupled to ATP and the membrane cytoskeleton via hDlg.
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Ibaraki, Soichi, und Masayoshi Tomizuka. „Tuning of a Hard Disk Drive Servo Controller Using Fixed-Structure H∞ Controller Optimization“. Journal of Dynamic Systems, Measurement, and Control 123, Nr. 3 (09.06.2000): 544–49. http://dx.doi.org/10.1115/1.1386391.
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As the storage capacity of hard disk drives (HDDs) increases dramatically, the demand for positioning control accuracy of a read/write head of HDD is becoming more stringent. This paper presents a tuning methodology for fixed-structure controllers using the H∞ optimization. The tuning of a PID (Proportional plus Integral plus Derivative) controller for head positioning of an HDD is presented as an application example. The H∞ optimization problem of fixed-structure controllers can be locally solved by using the transformation into an H∞ synthesis problem of static output feedback control. Simulation and experimental results show the effectiveness of the proposed approach as a fine tuning method to improve controller performance without requiring profound knowledge and experiences in manual loop-shaping.
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Rakcheep, Maneerat, Metinan Laosakun, Sorada Khaengkarn und Jiraphon Srisertpol. „Enhancing testing cell set efficiency: A machine learning approach on hard disk drive data“. Manufacturing Review 11 (2024): 11. http://dx.doi.org/10.1051/mfreview/2024008.
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Hard Disk Drive (HDD) products undergo meticulous testing procedures to ensure their functionality prior to customer distribution. Nevertheless, anomalies can arise within the testing environment due to various factors, such as an increased number of media discs, leading to heightened current consumption by the spindle motor, and the frequent insertion and removal of HDDs during testing. These factors can induce malfunctions within the testing cell, which are identified by the tester's program. This study leverages diverse data measurements collected from tester HDDs within the testing cell to predict the status of the testing cell itself. Five distinct algorithms—Linear Discriminant Analysis (LDA), Ridge Classifier CV (RCCV), Extra-Tree Classifier (ETC), Random Forest Classifier (RFC), and Extreme Gradient Boosting (XGBoost)—were assessed. The research underscores that the proposed methodology, particularly utilizing XGBoost, achieves a notable prediction accuracy of 87.9% when applied to real datasets.
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Muthukrishnan, Prathiba, und Sivanantham Sathasivam. „A Technical Survey on Delay Defects in Nanoscale Digital VLSI Circuits“. Applied Sciences 12, Nr. 18 (10.09.2022): 9103. http://dx.doi.org/10.3390/app12189103.
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As technology scales down, digital VLSI circuits are prone to many manufacturing defects. These defects may result in functional and delay-related circuit failures. The number of test escapes grows when technology is downscaled. Small delay defects (SDDs) and hidden delay defects (HDDs) are of critical importance in industries today since they are the source of most test escapes and reliability problems. Improving test quality and creating new test methods, algorithms, and test designs requires a comprehensive study of these delay defects. This article reviews the effect and impact of SDD and HDD in logic circuits. It also analyzes the relevant fault models, automatic test pattern generation (ATPG) methods, faster-than-at-speed testing (FAST), cell-aware (CA) based delay tests, test quality metrics, diagnosis of SDDs and HDDs, and commercially available Electronic Design Automation (EDA) tools. Based on the analysis, the benefits and drawbacks of several accessible approaches are addressed.
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Nebenzahl, L., R. Nagarajan, J. Wong, L. Volpe und G. Whitney. „Chemical Integration and Contamination Control In Hard Disk Drive Manufacturing“. Journal of the IEST 41, Nr. 5 (14.09.1998): 31–35. http://dx.doi.org/10.17764/jiet.41.5.b3m3376867pj0232.
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As we approach the turn of the century, the demand for storage is rapidly increasing, fueled by multimedia and its associated applications. Hard disk drive (HDD) manufacturers continue to respond by chasing the areal density curve to provide higher capacity and higher performance disk drives. The required technology changes are expected to aggravate performance and reliability problems, such as stiction, associated with organic contamination; thermal asperities, associated with particulate contamination; and corrosion, associated with ionic contamination. Anticipation and proactive resolution of chemical integration and contamination control problems are key to the successful development and manufacturing of advanced HDDs. In this paper, types and sources of contamination that can impact HDD performance are described; various contamination-related problems are reviewed; and a methodology by which successful chemical integration in the hard disk drive business can be accomplished is outlined.
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Abdelmegeed, Mohamed A. Elbadawy, und Hesham Rakha. „Heavy-Duty Diesel Truck Emissions Modeling“. Transportation Research Record: Journal of the Transportation Research Board 2627, Nr. 1 (Januar 2017): 26–35. http://dx.doi.org/10.3141/2627-04.
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Heavy-duty vehicles are the second-largest source of greenhouse gas emissions and energy use within the transportation sector even though they represent only a small portion of on-road vehicles. Heavy-duty diesel vehicles (HDDVs) emit about half of all on-road emissions of nitrogen oxide (NOx). However, because of the limited amount of HDDV emissions data, research has focused on light-duty vehicle emissions. The majority of these microscopic models suffer from two major limitations: the models result in a bang-bang control system and calibration of the model parameters is not possible with publicly available data. This paper proposes to extend the Virginia Tech Comprehensive Power-Based Fuel Consumption Model (VT-CPFM) to overcome the two shortcomings in state-of-the-practice HDDV emissions models of carbon monoxide (CO), hydrocarbons (HCs), and NOx. Heavy-duty diesel truck (HDDT) data from the University of California, Riverside, were used for the calibration and validation processes. The study’s results were satisfying, especially for NOx, which was the main concern in HDDV emissions. Model validity and performance were evaluated by comparing the correlation of measured field data and estimated emissions between the VT-CPFM model and the comprehensive modal emissions model (CMEM). The results demonstrate the efficacy of the VT-CPFM model in replicating empirical observations producing better accuracy compared with other state-of-the-practice models (e.g., CMEM). Moreover, unlike the CMEM model, which requires extensive data collection for calibration purposes, the VT-CPFM model needs only GPS and publicly accessible data for calibration.
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Min, He Qun, Xiao Yang Huang und Qi De Zhang. „Pressure Fluctuations and Flow-Induced Vibration Measurements in a Hard Disk Drive under Different Rotation Speeds“. Applied Mechanics and Materials 197 (September 2012): 292–96. http://dx.doi.org/10.4028/www.scientific.net/amm.197.292.
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Flow-induced vibration (FIV) of a head gimbals assembly (HGA) in hard disk drives (HDDs) limits the positioning accuracy of magnetic head in the HGA for higher HDD magnetic recording density. The pressure fluctuations characterize turbulent fluctuations exciting the HGA off-track vibration (HGA-OTV). In this paper, experimental studies have been carried out to investigate the spectrum characteristics correspondence between pressure fluctuations around an HGA and the simultaneous HGA-OTV under different HDD rotation speeds. A practical and effective experimental setup has been implemented to enable the simultaneous measurements on both the pressure fluctuation and HGA-OTV signals, where pressure fluctuations are measured with a pressure transducer through a small hole on the HDD top cover and the direct HGA-OTV signals are detected through a laser Doppler vibrometer. Results under conditions of three different HDD rotation speeds of 7200, 9000, 10800 rpm have been investigated and compared. It is shown that the HGA off-track vibration spectra are highly associated with those of the pressure fluctuations in terms of principal peaks in four frequency bands around 1.8 kHz, 2.5-3.5 kHz, 7-7.5 kHz and 11.5-12.5 kHz. With increasing HDD rotation speed, it is shown that the spectrum magnitudes of both the pressure fluctuation and the HGA off-track vibration increase correspondingly, while the principal peak positions in spectra of either pressure fluctuation or the HGA off-track vibration always hold the line. This study demonstrates a causal nexus from the pressure fluctuation to the HGA off-track vibration and suggests the feasibility of controlling the HGA-OTV through suppression of pressure fluctuations around the HGA.
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Skrzekut, Tomasz, Maciej Wędrychowicz und Andrzej Piotrowicz. „Recycling of Hard Disk Drive Platters via Plastic Consolidation“. Materials 16, Nr. 20 (18.10.2023): 6745. http://dx.doi.org/10.3390/ma16206745.
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The paper presents the comparison of two methods of recycling aluminum from HDD platters—the melting method and the method of plastic consolidation. The main elements of HDD memory, i.e., data carriers (platters), were examined via the percentage share of the total HDD mass and also via EDS analysis. The most common are platters made of the aluminum alloy series 5XXX, which are covered with a thin magnetic layer made of nickel. The research involved removing data carriers from about 30 HDDs and fragmenting them. The next step was to divide the platters into three groups; one was melted, the second was subjected to plastic consolidation, and the third group was fragmented into chips and also subjected to the consolidation process. Then, in the process of co-extrusion, rods were extruded from each material, and were subjected to EDS analysis, microstructure testing, Vickers hardness, and uniaxial tensile tests, and then the obtained results were compared. The obtained results of the microstructural tests in the case of gravity cast material confirmed the presence of the Al3Ni globular phase in the matrix. In the case of pressed and extruded materials, the Al3Ni phase appeared at the Ni-AlMg contact. After plastic consolidation, all the tested rods were characterized by their comparable strength properties (a tensile strength of 250 MPa and yield strength of 105 MPa).
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Wasala, Sahan, Wenguang Zhao, Oluwaseyi Ogun, Lon Stevens, Raye Sosseh, John Kennedy und Tim Persoons. „Acoustic Metamaterials for Electronics Cooling Fan Noise Reduction“. INTER-NOISE and NOISE-CON Congress and Conference Proceedings 268, Nr. 5 (30.11.2023): 3145–53. http://dx.doi.org/10.3397/in_2023_0454.
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Acoustic noise is a significant obstacle that limits the performance of data centre Hard Disk Drive (HDD) storage systems. The primary noise source of these systems has been identified as cooling fans that are used for their thermal management. New acoustic metamaterial (AM) designs can be used as a solution to this problem. AMs can be custom-designed to address specific tonal frequencies that HDD servo systems show high sensitivity to. This paper focuses on developing a 3D-printed annular AM treatment that can be easily attached to the inlet or outlet of an axial fan. Initial design optimization was conducted using the Finite Element Method (FEM). Further FEM simulations were carried out using more realistic fan sources from high-fidelity Computational Fluid Dynamics (CFD) simulations. The AM geometry was tested experimentally with a fan that is commonly used in a data centre storage system, where the fan speed was set to induce an acoustic tone that negatively affects the performance of HDDs. Then a full scale Finite Element Method simulation was ran using fan acoustic source data extracted from a high fidelity CFD simulation. Results indicate significant noise reduction at the targeted frequency.
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Lien, Yi-Han, Yen-Ting Chen, Yuan-Hao Chang, Yu-Pei Liang und Wei-Kuan Shih. „FSIMR: File-system-aware Data Management for Interlaced Magnetic Recording“. ACM Transactions on Embedded Computing Systems 22, Nr. 5s (09.09.2023): 1–18. http://dx.doi.org/10.1145/3607922.
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Interlaced Magnetic Recording (IMR) is an emerging recording technology for hard-disk drives (HDDs) that provides larger storage capacity at a lower cost. By partially overlapping (interlacing) each bottom track with two adjacent top tracks, IMR-based HDDs successfully increase the data density while incurring some hardware write constraints. To update each bottom track, the data on two adjacent top tracks must be read and rewritten to avoid losing their valid data, resulting in additional overhead for performing read-modify-write (RMW) operations. Therefore, researchers have proposed various data management schemes to mitigate such overhead in recent years, aiming at improving the write performance. However, these designs have not taken into account the data characteristics of the file system, which is a crucial layer of operating systems for storing/retrieving data into/from HDDs. Consequently, the write performance improvement is limited due to the unawareness of spatial locality and hotness of data. This paper proposes a file-system-aware data management scheme called FSIMR to improve system write performance. Noticing that data of the same directory may have higher spatial locality and are mostly updated at the same time, FSIMR logically partitions the IMR-based HDD into fixed-sized zones; data belonging to the same directory will be arranged to one zone to reduce the time of seeking to-be-updated data (seek time). Furthermore, cold data within a zone are arranged to bottom tracks and updated in an out-of-place manner to eliminate RMW operations. Our experimental results show that the proposed FSIMR could reduce the seek time by up to 14% without introducing additional RMW operations, compared to existing designs.
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Ayeche, Farid, und Adel Alti. „HDG and HDGG: an extensible feature extraction descriptor for effective face and facial expressions recognition“. Pattern Analysis and Applications 24, Nr. 3 (17.03.2021): 1095–110. http://dx.doi.org/10.1007/s10044-021-00972-2.
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Liu, Yan, und Hejun Du. „Investigation of HDD Ramp Unloading Processes with an Efficient Scheme“. Advances in Applied Mathematics and Mechanics 3, Nr. 6 (Dezember 2011): 716–28. http://dx.doi.org/10.4208/aamm.10-m1001.
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AbstractRamp load/unload (L/UL) mechanisms are widely used to rest sliders in hard disk drives (HDDs). Loading/unloading a slider swiftly and smoothly is crucial in a HDD design. A novel, efficient simulation scheme is proposed to investigate the behaviors of a head disk interface (HDI) in ramp unloading processes. A dual scale model is enabled by decoupling the nano-meter scale change of an air bearing and the micro- or milli-meter scale deformation of a suspension. A modified Reynolds equation governing the air bearing was solved numerically. The slider design was characterized with performance functions. Three stages in an unloading process were analyzed with a lumped parameter suspension model. Key parameters for the model were estimated with a comprehensive finite element suspension model. Finally, simulation results are presented for a commercial HDI design.
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Grammatico-Guillon, Leslie, Sabine Baron, Christophe Gaborit, Emmanuel Rusch und Pascal Astagneau. „Quality Assessment of Hospital Discharge Database for Routine Surveillance of Hip and Knee Arthroplasty–Related Infections“. Infection Control & Hospital Epidemiology 35, Nr. 6 (Juni 2014): 646–51. http://dx.doi.org/10.1086/676423.
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Objective.Surgical site infection (SSI) surveillance represents a key method of nosocomial infection control programs worldwide. However, most SSI surveillance systems are considered to be poorly cost effective regarding human and economic resources required for data collection and patient follow up. This study aims to assess the efficacy of using hospital discharge databases (HDDs) as a routine surveillance system for detecting hip or knee arthroplasty–related infections (HKAIs).Methods.A case-control study was conducted among patients hospitalized in the Centre region of France between 2008 and 2010. HKAI cases were extracted from the HDD with various algorithms based on the International Classification of Diseases, Tenth Revision, and procedure codes. The control subjects were patients with hip or knee arthroplasty (HKA) without infection selected at random from the HDD during the study period. The gold standard was medical chart review. Sensitivity (Se), specificity (Spe), positive predictive value (PPV), and negative predictive value (NPV) were calculated to evaluate the efficacy of the surveillance system.Results.Among 18,265 hospital stays for HKA, corresponding to 17,388 patients, medical reports were checked for 1,010 hospital stays (989 patients). We identified 530 cases in total (incidence rate, 1% [95% confidence interval (CI), 0.4%–1.6%), and 333 cases were detected by routine surveillance. As compared with 480 controls, Se was 98%, Spe was 71%, PPV was 63%, and NPV was 99%. Using a more specific case definition, based on a sample of 681 hospital stays, Se was 97%, Spe was 95%, PPV was 87%, and NPV was 98%.Conclusions.This study demonstrates the potential of HDD as a tool for routine SSI surveillance after low-risk surgery, under conditions of having an appropriate algorithm for selecting infections.Infect Control Hosp Epidemiol 2014;35(6):646–651
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Sheu, Gwo-Tarng. „Initiation of hepatitis delta virus (HDV) replication: HDV RNA encoding the large delta antigen cannot replicate“. Journal of General Virology 83, Nr. 10 (01.10.2002): 2507–13. http://dx.doi.org/10.1099/0022-1317-83-10-2507.
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The hepatitis delta virus (HDV) nucleocapsid consists of a genomic-length RNA of 1·7 kb and approximately equimolar amounts of the small and large forms of the hepatitis delta antigen (S-HDAg and L-HDAg, respectively). Since HDV RNA particles contain not only a genomic RNA species encoding S-HDAg but also an RNA species encoding L-HDAg, which is produced by an RNA-editing process, the question arises as to whether RNAs encoding either L-HDAg or S-HDAg can initiate replication. To study this, two cDNA-free transfection methods were employed: HDV RNA cotransfected with either the S-HDAg-encoding mRNA species or the ribonucleocapsid protein complex, comprising HDV RNA and recombinant S-HDAg. Results showed that the genomic-sense RNA encoding S-HDAg could promote HDV replication, whereas the L-HDAg-encoding RNA species was unable to replicate under the same conditions. The antigenomic RNA species encoding either S-HDAg or L-HDAg could not replicate by either of these procedures. In addition, L-HDAg alone could not promote replication of the genomic RNA but, by supplementing an equal amount of S-HDAg, replication occurred. These data indicate that L-HDAg-encoding RNA species are probably not involved in the initiation of HDV RNA synthesis; instead, their main function may be to serve as template for producing L-HDAg, which regulates HDV RNA synthesis and virion assembly. These results suggest that the genomic RNA species encoding S-HDAg is the only functional genome for HDV infection and explain why the presence of the edited HDV RNA encoding L-HDAg does not interfere with HDV infection.
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Alho, H. „Disulfiram, Naltrexone and Acamprosate in the Treatment of Alcohol Dependence“. European Psychiatry 24, S1 (Januar 2009): 1. http://dx.doi.org/10.1016/s0924-9338(09)70531-0.
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Acamprosate, naltrexone and disulfiram have been shown to reduce drinking and/or improve abstinence. We performed a randomized, multicenter study in two phases; first, 12-week continuous supervised medication, followed by targeted medication up to 52 weeks in addition to a 67-week follow up period. 243 voluntary treatment-seeking alcohol-dependent adult outpatients were randomized 1:1:1 to receive supervised naltrexone, acamprosate or disulfiram, 50 mg, 1998 mg or 200 mg respectively per day and brief manual-based cognitive behavioral intervention. The primary outcome measures were the time to first heavy drinking day (HDD) and time during the first 3 months to the first drinking day after medication started. All three study groups showed marked reduction in drinking from baseline to the end of the study. During the continuous medication phase, treatment with disulfiram was more effective in reducing HDDs and average weekly alcohol consumption, and increasing time to the first drink as well as the number of abstinent days. During the targeted medication period, there were no significant differences between the groups in time to first HDD and days to first drinking, but the abstinence days were significantly more frequent in the DIS group than ACA and NTX. However, naltrexone was better than acamprosate in reducing the severity of alcohol dependence indicator SADD scores. We conclude that acamprosate, naltrexone and disulfiram combined with brief manual-based cognitive behavioral intervention significantly reduce alcohol consumption and improve the quality of life. Supervised disulfiram was superior, especially during the continuous medication period, to naltrexone and acamprosate.
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O'Malley, Brendan, und David W. Lazinski. „Roles of Carboxyl-Terminal and Farnesylated Residues in the Functions of the Large Hepatitis Delta Antigen“. Journal of Virology 79, Nr. 2 (15.01.2005): 1142–53. http://dx.doi.org/10.1128/jvi.79.2.1142-1153.2005.
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ABSTRACT The large hepatitis delta antigen (HDAg-L) mediates hepatitis delta virus (HDV) assembly and inhibits HDV RNA replication. Farnesylation of the cysteine residue within the HDAg-L carboxyl terminus is required for both functions. Here, HDAg-L proteins from different HDV genotypes and genotype chimeric proteins were analyzed for their ability to incorporate into virus-like particles (VLPs). Observed differences in efficiency of VLP incorporation could be attributed to genotype-specific differences within the HDAg-L carboxyl terminus. Using a novel assay to quantify the extent of HDAg-L farnesylation, we found that genotype 3 HDAg-L was inefficiently farnesylated when expressed in the absence of the small hepatitis delta antigen (HDAg-S). However, as the intracellular ratio of HDAg-S to HDAg-L was increased, so too was the extent of HDAg-L farnesylation for all three genotypes. Single point mutations within the carboxyl terminus of HDAg-L were screened, and three mutants that severely inhibited assembly without affecting farnesylation were identified. The observed assembly defects persisted under conditions where the mutants were known to have access to the site of VLP assembly. Therefore, the corresponding residues within the wild-type protein are likely required for direct interaction with viral envelope proteins. Finally, it was observed that when HDAg-S was artificially myristoylated, it could efficiently inhibit HDV RNA replication. Hence, a general association with membranes enables HDAg to inhibit replication. In contrast, although myristoylated HDAg-S was incorporated into VLPs far more efficiently than HDAg-S or nonfarnesylated HDAg-L, it was incorporated far less efficiently than wild-type HDAg-L; thus, farnesylation was required for efficient assembly.
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Wetherill, Reagan R., Nathaniel Spilka, Kanchana Jagannathan, Paige Morris, Danielle Romer, Timothy Pond, Kevin G. Lynch, Teresa R. Franklin und Henry R. Kranzler. „Effects of topiramate on neural responses to alcohol cues in treatment-seeking individuals with alcohol use disorder: preliminary findings from a randomized, placebo-controlled trial“. Neuropsychopharmacology 46, Nr. 8 (08.02.2021): 1414–20. http://dx.doi.org/10.1038/s41386-021-00968-w.
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AbstractTopiramate, a GABA/glutamate modulator, is efficacious in reducing alcohol consumption, though the mechanisms underlying this effect are not well characterized. This study analyzed functional magnetic resonance imaging (fMRI) data from 22 heavy drinkers enrolled in a 12-week placebo-controlled, randomized clinical trial of topiramate to examine the effects of topiramate on alcohol cue-elicited brain responses, craving, and heavy drinking in individuals with DSM-5 alcohol use disorder. Patients were randomized to receive either topiramate (maximal daily dosage of 200 mg/day) or placebo and were administered an fMRI alcohol cue-reactivity task at baseline (before starting medication) and after 6 weeks of double-blind treatment. Analyses compared the topiramate (n = 12) and placebo (n = 8) groups on (1) the change in brain responses during alcohol cue exposure (vs non-alcohol cues) within five a priori regions of interest related to reward—the bilateral and medial orbitofrontal cortex (OFC) and bilateral ventral striatum (VS) and (2) change in craving and heavy drinking days (HDDs) from baseline and scan 2. Topiramate, relative to placebo, reduced alcohol cue-elicited activation of the left VS, bilateral OFC, and medial OFC, alcohol cue-elicited craving, and HDDs between baseline and 6 weeks of treatment. The reduction in alcohol cue-elicited activation in the medial OFC correlated with reductions in craving, and reduced activation in the right VS, right OFC, and medial OFC correlated with the reduction in HDD. This preliminary study provides evidence that topiramate’s attenuation of alcohol cue-elicited brain activation and craving are key elements of the drug’s neurobiological mechanism of action in reducing heavy drinking.
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Tseng, Chung-Hsin, Tai-Shan Cheng, Chiung-Yueh Shu, King-Song Jeng und Michael M. C. Lai. „Modification of Small Hepatitis Delta Virus Antigen by SUMO Protein“. Journal of Virology 84, Nr. 2 (04.11.2009): 918–27. http://dx.doi.org/10.1128/jvi.01034-09.
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ABSTRACT Hepatitis delta antigen (HDAg) is a nuclear protein that is intimately involved in hepatitis delta virus (HDV) RNA replication. HDAg consists of two protein species, the small form (S-HDAg) and the large form (L-HDAg). Previous studies have shown that posttranslational modifications of S-HDAg, such as phosphorylation, acetylation, and methylation, can modulate HDV RNA replication. In this study, we show that S-HDAg is a small ubiquitin-like modifier 1 (SUMO1) target protein. Mapping data showed that multiple lysine residues are SUMO1 acceptors within S-HDAg. Using a genetic fusion strategy, we found that conjugation of SUMO1 to S-HDAg selectively enhanced HDV genomic RNA and mRNA synthesis but not antigenomic RNA synthesis. This result supports our previous proposition that the cellular machinery involved in the synthesis of HDV antigenomic RNA is different from that for genomic RNA synthesis and mRNA transcription, requiring different modified forms of S-HDAg. Sumoylation represents a new type of modification for HDAg.
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Mokal, Vaibhav Umesh. „Hard Disk Drive Failure Detection Using Hybrid Algorithm“. International Journal for Research in Applied Science and Engineering Technology 9, Nr. 9 (30.09.2021): 1233–44. http://dx.doi.org/10.22214/ijraset.2021.37976.
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Abstract: The data is the most valuable thing in this modern world of Information Technology. As we can see the day to day the data is increasing as each and every people using the World Wide Web. This all system generated data or may be the personal or informative data will get generated in a huge amount of size. That data will get stored at the data centers or on cloud. But those will get stored on the Hard Disk Drives in data centers. So in some situation if the HDD got crashed then we will have lost our data. This work proposes to develop the failure prediction of Hard disk drive. We have chosen the accuracy and review measurements, generally important to the issue, and tried a few learning strategies, Adaboost, Naive Bayes, Logistic Regression and Voting. Our investigation shows that while we can't accomplish close to 100% forecast precision utilizing ML with the present information we have accessible for HDDs, we can improve our expectation exactness over the standard methodology Keywords: Machine learning, Adaboost, Naive Bayes, Voting, Logistic Regression
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Li, Yi-Jia, Michael R. Stallcup und Michael M. C. Lai. „Hepatitis Delta Virus Antigen Is Methylated at Arginine Residues, and Methylation Regulates Subcellular Localization and RNA Replication“. Journal of Virology 78, Nr. 23 (01.12.2004): 13325–34. http://dx.doi.org/10.1128/jvi.78.23.13325-13334.2004.
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ABSTRACT Hepatitis delta virus (HDV) contains a circular RNA which encodes a single protein, hepatitis delta antigen (HDAg). HDAg exists in two forms, a small form (S-HDAg) and a large form (L-HDAg). S-HDAg can transactivate HDV RNA replication. Recent studies have shown that posttranslational modifications, such as phosphorylation and acetylation, of S-HDAg can modulate HDV RNA replication. Here we show that S-HDAg can be methylated by protein arginine methyltransferase (PRMT1) in vitro and in vivo. The major methylation site is at arginine-13 (R13), which is in the RGGR motif of an RNA-binding domain. The methylation of S-HDAg is essential for HDV RNA replication, especially for replication of the antigenomic RNA strand to form the genomic RNA strand. An R13A mutation in S-HDAg inhibited HDV RNA replication. The presence of a methylation inhibitor, S-adenosyl-homocysteine, also inhibited HDV RNA replication. We further found that the methylation of S-HDAg affected its subcellular localization. Methylation-defective HDAg lost the ability to form a speckled structure in the nucleus and also permeated into the cytoplasm. These results thus revealed a novel posttranslational modification of HDAg and indicated its importance for HDV RNA replication. This and other results further showed that, unlike replication of the HDV genomic RNA strand, replication of the antigenomic RNA strand requires multiple types of posttranslational modification, including the phosphorylation and methylation of HDAg.
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Zhang, Yu, Yongzhe Fan, Xue Zhao, An Du, Ruina Ma, Jianjun Wu und Xiaoming Cao. „Influence of Graphite Morphology on Phase, Microstructure, and Properties of Hot Dipping and Diffusion Aluminizing Coating on Flake/Spheroidal Graphite Cast Iron“. Metals 9, Nr. 4 (17.04.2019): 450. http://dx.doi.org/10.3390/met9040450.
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The influence of graphite morphology on the phase, microstructure and properties of hot dipping and diffusion aluminizing (HDDA) coating on flake/spheroidal graphite cast iron (FC/FCD) was investigated. The microstructure and properties of the HDDA coatings on FC/FCD were determined by the graphite morphology. The outer and inner layers of the HDDA coating comprised the Fe2Al5 and FeAl phases, respectively. The outer layer of HDDA on FCD was dense and uniform; however, some pores of different sizes were found in the outer coating on FC, resulting in looser HDDA coating. Hence, the wear resistance of the HDDA coating on FC was worse than that of the coating on FCD. During oxidation, many continuous oxidation channels were formed from the coating surface to the matrix in the HDDA coating on FC, resulting in the oxidation of graphite in the HDDA coating and the matrix. However, only exposed spheroidal graphite was oxidized in the HDDA coating on FCD. Thus, the high-temperature oxidation resistance of the HDDA coating on FC was also worse than that of the coating on FCD.
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Modahl, Lucy E., und Michael M. C. Lai. „The Large Delta Antigen of Hepatitis Delta Virus Potently Inhibits Genomic but Not Antigenomic RNA Synthesis: a Mechanism Enabling Initiation of Viral Replication“. Journal of Virology 74, Nr. 16 (15.08.2000): 7375–80. http://dx.doi.org/10.1128/jvi.74.16.7375-7380.2000.
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ABSTRACT Hepatitis delta virus (HDV) contains two types of hepatitis delta antigens (HDAg) in the virion. The small form (S-HDAg) is required for HDV RNA replication, whereas the large form (L-HDAg) potently inhibits it by a dominant-negative inhibitory mechanism. The sequential appearance of these two forms in the infected cells regulates HDV RNA synthesis during the viral life cycle. However, the presence of almost equal amounts of S-HDAg and L-HDAg in the virion raised a puzzling question concerning how HDV can escape the inhibitory effects of L-HDAg and initiate RNA replication after infection. In this study, we examined the inhibitory effects of L-HDAg on the synthesis of various HDV RNA species. Using an HDV RNA-based transfection approach devoid of any artificial DNA intermediates, we showed that a small amount of L-HDAg is sufficient to inhibit HDV genomic RNA synthesis from the antigenomic RNA template. However, the synthesis of antigenomic RNA, including both the 1.7-kb HDV RNA and the 0.8-kb HDAg mRNA, from the genomic-sense RNA was surprisingly resistant to inhibition by L-HDAg. The synthesis of these RNAs was inhibited only when L-HDAg was in vast excess over S-HDAg. These results explain why HDV genomic RNA can initiate replication after infection even though the incoming viral genome is complexed with equal amounts of L-HDAg and S-HDAg. These results also suggest that the mechanisms of synthesis of genomic versus antigenomic RNA are different. This study thus resolves a puzzling question about the early events of the HDV life cycle.
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Mu, Jung-Jung, Hui-Lin Wu, Bor-Luen Chiang, Ruo-Ping Chang, Ding-Shinn Chen und Pei-Jer Chen. „Characterization of the Phosphorylated Forms and the Phosphorylated Residues of Hepatitis Delta Virus Delta Antigens“. Journal of Virology 73, Nr. 12 (01.12.1999): 10540–45. http://dx.doi.org/10.1128/jvi.73.12.10540-10545.1999.
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ABSTRACT Hepatitis delta virus (HDV) replication requires both the cellular RNA polymerase and one virus-encoded protein, small delta antigen (S-HDAg). S-HDAg has been shown to be a phosphoprotein, but its phosphorylation status is not yet clear. In this study, we employed three methods to address this question. A special two-dimensional gel electrophoresis, namely, nonequilibrium pH gradient electrophoresis, was used to separate the very basic S-HDAg. By carefully adjusting the pH of solubilization solution, the ampholyte composition, and the appropriate electrophoresis time periods, we were able to clearly resolve S-HDAg into two phosphorylated isoforms and one unphosphorylated form. In contrast, the viral large delta antigen (L-HDAg) can only be separated into one phosphorylated and one unphosphorylated form. By metabolic 32P labeling, both immunoprecipitated S-HDAg and L-HDAg were found to incorporate radioactive phosphate. The extent of S-HDAg phosphorylation was increased upon 12-O-tetradecanoylphorbol-13-acetate treatment, while that of L-HDAg was not affected. Finally, phosphoamino acid analysis identified serine and threonine as the phospho residues in the labeled S-HDAg and only serine in the L-HDAg. Therefore, HDV S- and L-HDAgs differ in their phosphorylation patterns, which may account for their distinct biological functions.
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Engerroff, Juliano Assis Baron, Frederico Orlandini Keller, Leonardo Ulian Lopes, Arthur Alvarez Mascheroni, Hidetoshi Takiishi und Paulo Antônio Pereira Wendhausen. „d-HDDR Processing of Nd-Fe-B Based Alloys to Obtain Highly Anisotropic Nanocrystalline Powders“. Materials Science Forum 899 (Juli 2017): 563–66. http://dx.doi.org/10.4028/www.scientific.net/msf.899.563.
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The HDDR (hydrogenation-disproportionation-desorption-recombination) process is an established powder metallurgy route to obtain Nd–Fe–B nanocrystalline powders for bonded magnets manufacturing. Therefore, both conventional (c-HDDR) and dynamic HDDR (d-HDDR) processes has been investigated to obtain Nd-Fe-B-based powders with different characteristics. Magnetic properties were measured by means of a hysteresisgraph and the powder obtained by d-HDDR showed strong anisotropy, allowing a Br of 1.1 T in the bonded magnet, whereas c-HDDR powder was isotropic with a Br of 0.6 T. Microstructural changes were characterized by X-ray diffraction (DRX) and scanning electron microscopy (SEM). X-ray patters of anisotropic powders made by d-HDDR showed high intensity reflection peaks indexed as (004), (105) and (006) planes in the aligning direction, due the texture inducement in c-axis of the main phase (Nd2Fe14B). However, SEM micrographs of c-HDDR powder showed a more homogeneous microstructure, with grain size of ~300 nm, when compared to d-HDDR powder that ranged from 300 nm to 500 nm. This difference is assumed to be the cause of lower intrinsic coercivity found in the c-HDDR powder.
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Namiki, Norikazu, Akihiro Komtasu, Keiji Watanabe und Naoki Kagi. „Surface Corrosion of HDD Media and Subsidiary Particle Formation Due to SO2 Gas Adsorption“. Journal of the IEST 50, Nr. 2 (01.10.2007): 38–51. http://dx.doi.org/10.17764/jiet.50.2.wh12q7h78l005042.
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The storage capacity of hard disk drives (HDDs) for personal computers has increased more than 10,000 times in the past decade. Meanwhile, the gap between the disk and the magnetic head (flying height) has decreased from sub-micrometers to a few nanometers. The lower flying height leads to more sensitive disk-to-surface contamination linked to fatal failures. Many studies have reported that disk surface contamination is related to the adsorption of volatile organic compounds (VOCs) and the corrosion of the magnetic layer of the disk. However, surface contamination derived from sulfur dioxide (SO2) gas in the surrounding area has been discussed insufficiently. In this work, to ascertain the mechanism of disk surface contamination and the subsidiary particle generation, HDD disks were intentionally exposed to SO2 gas, followed by an evaluation of disk operation performance during endurance testing. After the series of endurance tests, a large quantity of sulfate and nickel, which is a main component of the disk substrate layer, was detected on the SO2-contaminated disk surface, as well as a small quantity of cobalt, which is a main component of the magnetic layer. From these findings, the mechanism of surface contamination of HDD disks in the coexistence of SO2 and water was inferred. Nickel is supplied from the substrate layer to the top layer through holes and cracks in the films of disks because of the corrosion triggered by adsorbed water. High temperature and humidity causes the desorption of SO2 from SO2-contaminated disk surfaces to react with nickel. Eventually, the products of nickel sulfate are precipitated on the surface to be released in the form of particles by contact with the head.
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Callea, Giuditta, Maria Caterina Cavallo und Rosanna Tarricone. „PP149 Assessment Of New Medical Devices With Administrative Databases“. International Journal of Technology Assessment in Health Care 33, S1 (2017): 139–40. http://dx.doi.org/10.1017/s0266462317002926.
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INTRODUCTION:Administrative data (for example, hospital discharge databases, HDDs) can be used as a real world source of clinical and economic evidence for assessing new medical devices (MDs), provided that their use can be identified in the data. In absence of updated classification systems for procedures and diagnoses, which allow to identify the use of new technologies in the data, traceability can still be achieved thanks to authorities coding guidelines (that is, indication on how to combine the existing codes for procedures and/or diagnoses when new technologies are used).In 2009 Italy adopted version 2007 of the International Classification System of Diseases (ICD-9-CM) and version 24 of Diagnosis Related Groups (DRGs), which are still in use. The aim of this work was to investigate the capacity of the classification system currently used in Italy, which is at high risk of obsolescence, to identify innovative MDs.METHODS:To achieve our goal, we performed a systematic search of all the national and regional coding guidelines published from 2009 (that is, the year of introduction of the new classification systems) to 2015. We extracted from each document the list of technologies for which the Ministry of Health and/or the Regional Authorities provided with coding indications.RESULTS:Our results show that only a few recent technological innovations can be identified in the Italian HDDs. This reduces the possibility for decision makers to measure new technologies outcomes and costs in the real world clinical practice.CONCLUSIONS:The traceability of new MDs' can support Heath Technology Assessment (HTA). Indeed, HTA programs should use real world evidence to re-assess MDs 2–3 years after their introduction in clinical practice. The use of routinely collected data, such as HDD, would allow to measure new technologies' “real” effectiveness in “real” world, on “real” patients in “real” hospitals to complement the evidence from Randomized Controlled Trials.
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Guichardant, M., B. Chantegrel, C. Deshayes, A. Doutheau, P. Moliere und M. Lagarde. „Specific markers of lipid peroxidation issued from n−3 and n−6 fatty acids“. Biochemical Society Transactions 32, Nr. 1 (01.02.2004): 139–40. http://dx.doi.org/10.1042/bst0320139.
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Several markers of lipid peroxidation are available with different degrees of specificity, from malondialdehyde as a global marker, to F2-isoprostane, which is specifically produced from arachidonic acid. Among these, 4-hydroxynonenal is recognized as a breakdown product of fatty acid hydroperoxides, such as 15-hydroperoxy-eicosatetraenoic acid and 13-hydroperoxy-octade cadienoic acid from the n−6 fatty acids. Furthermore, 4-hydroxyhexenal (4-HHE) derives from n−3 fatty acid hydroperoxides. We have recently described the occurrence of 4-hydroxydodecadienal (4-HDDE) from the 12-lipoxygenase product of arachidonic acid 12-hydroperoxy-eicosatetraenoic acid. These three hydroxy-alkenals may be measured in human plasma by GC–MS, but they may partly be generated in the course of sampling, and the relative volatility of 4-HHE makes its measurement quite unreliable. We have successfully characterized and measured the stable oxidized carboxylic acid products from the hydroxy-alkenals 4-HNA, 4-HHA and 4-HDDA in urine. The ratio between 4-HHA and 4-HNA found in the same urinary sample might provide useful information on the location of lipid peroxidation, accounting for the high enrichment of the cerebrovascular system with docosahexaenoic acid, the main n−3 fatty acid in humans.
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Huang, Yi-Hsiang, Jaw-Ching Wu, Sheng-Chieh Hsu und Wan-Jr Syu. „VariedImmunity Generated in Mice by DNA Vaccines with Large and SmallHepatitis DeltaAntigens“. Journal of Virology 77, Nr. 24 (15.12.2003): 12980–85. http://dx.doi.org/10.1128/jvi.77.24.12980-12985.2003.
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ABSTRACT Whether the hepatitis delta virus (HDV) DNA vaccine can induce anti-HDV antibodies has been debatable. The role of the isoprenylated motif of hepatitis delta antigens (HDAg) in the generation of immune responses following DNA-based immunization has never been studied. Plasmids p2577L, encoding large HDAg (L-HDAg), p2577S, expressing small HDAg (S-HDAg), and p25L-211S, encoding a mutant form of L-HDAg with a cysteine-to-serine mutation at codon 211, were constructed in this study. Mice were intramuscularly injected with the plasmids. The anti-HDV antibody titers, T-cell proliferation responses, T-helper responses, and HDV-specific, gamma interferon (IFN-γ)-producing CD8+ T cells were analyzed. Animals immunized with p2577S showed a strong anti-HDV antibody response. Conversely, only a low titer of anti-HDV antibodies was detected in mice immunized with p2577L. Epitope mapping revealed that the anti-HDV antibodies generated by p2577L vaccination hardly reacted with epitope amino acids 174 to 194, located at the C terminus of S-HDAg. All of the HDAg-encoding plasmids could induce significant T-cell proliferation responses and generate Th1 responses and HDV-specific, IFN-γ-producing CD8+ T cells. In conclusion, HDAg-specific antibodies definitely exist following DNA vaccination. The magnitudes of the humoral immune responses generated by L-HDAg- and S-HDAg-encoding DNA vaccines are different. The isoprenylated motif can mask epitope amino acids 174 to 195 of HDAg but does not interfere with cellular immunity following DNA-based immunization. These findings are important for the choice of a candidate HDV DNA vaccine in the future.
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Zhu, Xuliang, Xin Huang, Jinbin Huang, Byron Choi und Jianliang Xu. „HDAG-explorer“. Proceedings of the VLDB Endowment 13, Nr. 12 (August 2020): 2973–76. http://dx.doi.org/10.14778/3415478.3415522.
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Hsu, Sheng-Chieh, Jaw-Ching Wu, I.-Jane Sheen und Wan-Jr Syu. „Interaction and Replication Activation of Genotype I and II Hepatitis Delta Antigens“. Journal of Virology 78, Nr. 6 (15.03.2004): 2693–700. http://dx.doi.org/10.1128/jvi.78.6.2693-2700.2004.
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ABSTRACT The nucleotide sequences of hepatitis D viruses (HDV) vary 5 to 14% among isolates of the same genotype and 23 to 34% among different genotypes. The only viral-genome-encoded antigen, hepatitis delta antigen (HDAg), has two forms that differ in size. The small HDAg (HDAg-S) trans-activates viral replication, while the large form (HDAg-L) is essential for viral assembly. Previously, it has been shown that the packaging efficiency of HDAg-L is higher for genotype I than for genotype II. In this study, the question of whether other functional properties of the HDAgs are affected by genotype differences is addressed. By coexpression of the two antigens in HuH-7 cells followed by specific antibody precipitation, it was found that HDAgs of different origins interacted without genotypic discrimination. Moreover, in the presence of hepatitis B virus surface antigen, HDAg-S was incorporated into virion-like particles through interaction with HDAg-L without genotype restriction. As to the differences in replication activation of genotype I HDV RNA, all HDAg-S clones tested had some trans-activation activity, and this activity varied greatly among isolates. As to the support of HDV genotype II replication, only clones of HDAg-S from genotype II showed trans-activation activity, and this activity also varied among isolates. In conclusion, genotype has no effect on HDAg interaction and genotype per se only partly predicts how much the HDAg-S of an HDV isolate affects the replication of a second HDV isolate.
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Singh, Sukhwinder, Nikhil Srinivasapura Venkateshmurthy, Kerry Ann Brown, Avinav Prasad Maddury, Rajesh Khatkar, Prashant Jarhyan, Dorairaj Prabhakaran und Sailesh Mohan. „Agricultural and Socioeconomic Factors Associated with Farmer Household Dietary Diversity in India: A Comparative Study of Visakhapatnam and Sonipat“. Sustainability 15, Nr. 4 (05.02.2023): 2873. http://dx.doi.org/10.3390/su15042873.
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Using primary data from 479 farmer households, this study examined the associations between agricultural and socioeconomic factors and farmer household dietary diversity in Visakhapatnam and Sonipat. Cropping intensity was positively associated with farmers’ household dietary diversity score (HDDS), suggesting that higher cropping intensity may expand the gross cropped area and improve food security among subsistence farmers. Distance to food markets was also significantly associated with farmer HDDS, which suggests that market integration with rural households can improve farmer HDDS in Visakhapatnam. In Sonipat, wealth index had a positive association with farmer HDDS, targeting the income pathway by improving farmer HDDS in this region. Considering the relative contribution of these factors, distance to food markets, cropping intensity, and crop diversity were the three most important factors affecting farmer HDDS in Visakhapatnam, whereas wealth index, cropping intensity, and distance to food markets emerged as the top three important factors contributing to farmer HDDS in Sonipat. Our study concludes that the associations between agricultural and socioeconomic factors and farmer HDDS are complex but context- and location-specific; therefore, considering the site- and context-specific circumstances, different connections to HDDS in India can be found to better support policy priorities on the ground.
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Barbier, Charlotte, Joseph A. C. Humphrey und Eric Maslen. „Experimental Study of the Flow in a Simulated Hard Disk Drive“. Journal of Fluids Engineering 128, Nr. 5 (13.03.2006): 1090–100. http://dx.doi.org/10.1115/1.2236135.
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Instantaneous circumferential and radial velocity components of the air flowing past a symmetrical pair of suspension/slider-units (SSUs) attached to an E-Block/arm were measured in a specially designed corotating disk apparatus simulating a hard disk drive (HDD) using the particle image velocimetry technique. The geometrical dimensions of the components in the apparatus test section were scaled up by a factor of two, approximately, relative to those of a nominal 312 inch HDD. Most of the measurements were obtained on the interdisk midplane for two angular orientations of the arm/SSUs: (a) One with the tip of the SSUs near the hub supporting the disks; (b) another with the tip of the SSUs near the rims of the disks. Data obtained for disk rotational speeds ranging from 250 to 3000rpm (corresponding to 1250 to 15,000rpm, approximately, in a 312 inch HDD) were post-processed to yield mean and rms values of the two velocity components and of the associated shear stress, the mean axial vorticity, and the turbulence intensity (based on the two velocity components). At the locations investigated near the arm/SSUs, and for disk rotational speeds larger than 1500rpm, the mean velocity components are found to be asymptotically independent of disk speed of rotation but their rms values appear to still be changing. At two locations 90 and 29deg, respectively, upstream of the arm/SSUs, the flow approaching this obstruction displays features that can be attributed to the three-dimensional wake generated by the obstruction. Also, between these two locations and depending on the angular orientation of the arm/SSUs, the effect of the obstruction is to induce a three-dimensional region of flow reversal adjacent to the hub. Notwithstanding, the characteristics of the flow immediately upstream and downstream of the arm/SSUs appear to be determined by local flow-structure interactions. Aside from their intrinsic fundamental value, the data serve to guide and test the development of turbulence models and numerical calculation procedures for predicting this complex class of confined rotating flows, and to inform the improved design of HDDs.
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Wang, Yun-Hsin, Shin C. Chang, Cheng Huang, Ya-Ping Li, Chia-Huei Lee und Ming-Fu Chang. „Novel Nuclear Export Signal-Interacting Protein, NESI, Critical for the Assembly of Hepatitis Delta Virus“. Journal of Virology 79, Nr. 13 (01.07.2005): 8113–20. http://dx.doi.org/10.1128/jvi.79.13.8113-8120.2005.
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ABSTRACT The process of host factor-mediated nucleocytoplasmic transport is critical for diverse cellular events in eukaryotes and the life cycle of viruses. We have previously identified a chromosome region maintenance 1-independent nuclear export signal (NES) at the C terminus of the large form of hepatitis delta antigen (HDAg), designated NES(HDAg-L) that is required for the assembly of hepatitis delta virus (HDV) (C.-H. Lee et al., J. Biol. Chem. 276:8142-8148, 2001). To look for interacting proteins of the NES(HDAg-L), yeast two-hybrid screening was applied using the GAL4-binding domain fused to the NES(HDAg-L) as bait. Among the positive clones, one encodes a protein, designated NESI [NES(HDAg-L) interacting protein] that specifically interacted with the wild-type NES(HDAg-L) but not with the export/package-defective HDAg-L mutant, NES*(HDAg-L), in which Pro-205 has been replaced by Ala. Northern blot analysis revealed NESI as the gene product of a 1.9-kb endogenous mRNA transcript that is present predominantly in human liver tissue. NESI consists of 467 amino acid residues and bears a putative actin-binding site and a bipartite nuclear localization signal. Specific interaction between HDAg-L and NESI was further confirmed by coimmunoprecipitation and immunofluorescence staining. Overexpression of antisense NESI RNAs inhibited the expression of NESI and abolished HDAg-L-mediated nuclear export and assembly of HDV genomic RNA. These data indicate a critical role of NESI in the assembly of HDV through interaction with HDAg-L.
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Macnaughton, Thomas B., und Michael M. C. Lai. „Large Hepatitis Delta Antigen Is Not a Suppressor of Hepatitis Delta Virus RNA Synthesis once RNA Replication Is Established“. Journal of Virology 76, Nr. 19 (01.10.2002): 9910–19. http://dx.doi.org/10.1128/jvi.76.19.9910-9919.2002.
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ABSTRACT Moderation of hepatitis delta virus (HDV) replication is a likely prerequisite in the establishment of chronic infections and is thought to be mediated by the intracellular accumulation of large hepatitis delta antigen (L-HDAg). The regulatory role of this protein was suggested from several studies showing that cotransfection of plasmid cDNAs expressing both L-HDAg and HDV RNA results in a potent inhibition of HDV RNA replication. However, since this approach differs significantly from natural HDV infections, where HDV RNA replication is initiated from an RNA template, and L-HDAg appears only late in the replication cycle, it remains unclear whether L-HDAg can modulate HDV RNA replication in the natural HDV replication cycle. In this study, we investigated the effect of L-HDAg, produced as a result of the natural HDV RNA editing event, on HDV RNA replication. The results showed that following cDNA-free HDV RNA transfection, a steady-state level of RNA was established at 3 to 4 days posttransfection. The same level of HDV RNA was reached when a mutant HDV genome unable to make L-HDAg was used, suggesting that L-HDAg did not play a role. The rates of HDV RNA synthesis, as measured by metabolic labeling experiments, were identical at 4 and 8 days posttransfection and in the wild type and the L-HDAg-deficient mutant. We further examined the effect of overexpression of L-HDAg at various stages of the HDV replication cycle, showing that HDV RNA synthesis was resistant to L-HDAg when it was overexpressed 3 days after HDV RNA replication had initiated. Finally, we showed that, contrary to conventional thinking, L-HDAg alone, at a certain molar ratio with HDV RNA, can initiate HDV RNA replication. Thus, L-HDAg does not inherently inhibit HDV RNA synthesis. Taken together, these results indicated that L-HDAg affects neither the rate of HDV RNA synthesis nor the final steady-state level of HDV RNA and that L-HDAg is unlikely to act as an inhibitor of HDV RNA replication in the natural HDV replication cycle.
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Yoo, Jae-Gyeong, Tae-Hoon Kim, Hee-Ryoung Cha, Yang-Do Kim und Jung-Goo Lee. „Design of High-Remanence Nd-Fe-B Hot-Pressed Magnets by Manipulating Coercivity of Hydrogenation-Disproportionation-Desorption-Recombination Treated Anisotropic Precursors“. Materials 16, Nr. 24 (11.12.2023): 7599. http://dx.doi.org/10.3390/ma16247599.
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We propose a method of manipulating the coercivity of anisotropic hydrogenation-disproportionation-desorption-recombination (HDDR) powders to fabricate high-remanence and fine-grained Nd-Fe-B magnets using only hot-pressing without a subsequent hot-deformation process. By reducing the Nd content of anisotropic HDDR precursors such that their coercivity (Hcj) is lowered, the c-axis of each HDDR particle is well-aligned parallel to the direction of the applied magnetic field during the magnetic alignment step. This is because the magnetic repulsive force between adjacent particles, determined by their remanent magnetization, decreases as a result of the low coercivity of each particle. Therefore, after hot-pressing the low-Hcj HDDR powders, a significantly higher remanence (11.2 kG) is achieved in the bulk than that achieved by hot-pressing the high-Hcj HDDR powders (8.2 kG). It is clearly confirmed by the large-scale electron backscatter diffraction (EBSD) analysis that the alignment of the c-axis of each anisotropic HDDR particle in the bulk is improved when low-Hcj HDDR powders are used to fabricate hot-pressed magnets. This coercivity manipulation of HDDR powders can be a helpful method to expand the use of HDDR powders in fabricating anisotropic Nd-Fe-B bulk magnets.
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Lin, Brian C., Dawn A. Defenbaugh und John L. Casey. „Multimerization of Hepatitis Delta Antigen Is a Critical Determinant of RNA Binding Specificity“. Journal of Virology 84, Nr. 3 (18.11.2009): 1406–13. http://dx.doi.org/10.1128/jvi.01723-09.
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ABSTRACT Hepatitis delta virus (HDV) RNA forms an unbranched rod structure that is associated with hepatitis delta antigen (HDAg) in cells replicating HDV. Previous in vitro binding experiments using bacterially expressed HDAg showed that the formation of a minimal ribonucleoprotein complex requires an HDV unbranched rod RNA of at least about 300 nucleotides (nt) and suggested that HDAg binds the RNA as a multimer of fixed size. The present study specifically examines the role of HDAg multimerization in the formation of the HDV ribonucleoprotein complex (RNP). Disruption of HDAg multimerization by site-directed mutagenesis was found to profoundly alter the nature of RNP formation. Mutant HDAg proteins defective for multimerization exhibited neither the 300-nt RNA size requirement for binding nor specificity for the unbranched rod structure. The results unambiguously demonstrate that HDAg binds HDV RNA as a multimer and that the HDAg multimer is formed prior to binding the RNA. RNP formation was found to be temperature dependent, which is consistent with conformational changes occurring on binding. Finally, analysis of RNPs constructed with unbranched rod RNAs successively longer than the minimum length indicated that multimeric binding is not limited to the first HDAg bound and that a minimum RNA length of between 604 and 714 nt is required for binding of a second multimer. The results confirm the previous proposal that HDAg binds as a large multimer and demonstrate that the multimer is a critical determinant of the structure of the HDV RNP.
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Li, Yuanzheng, Jinyuan Li, Ao Xu, Zhizhi Feng, Chanjuan Hu und Guosong Zhao. „Spatial-Temporal Changes and Associated Determinants of Global Heating Degree Days“. International Journal of Environmental Research and Public Health 18, Nr. 12 (08.06.2021): 6186. http://dx.doi.org/10.3390/ijerph18126186.
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The heating degree days (HDDs) could indicate the climate impact on energy consumption and thermal environment conditions effectively during the winter season. Nevertheless, studies on the spatial-temporal changes in global HDDs and their determinants are scarce. This study used multi-source data and several methods to explore the rules of the spatial distribution of global HDDs and their interannual changes over the past 49 years and some critical determinants. The results show that global HDDs generally became larger in regions with higher latitudes and altitudes. Most global change rates of HDDs were negative (p < 0.10) and decreased to a greater extent in areas with higher latitudes. Most global HDDs showed sustainability trends in the future. Both the HDDs and their change rates were significantly partially correlated with latitude, altitude, mean albedo, and EVI during winter, annual mean PM2.5 concentration, and nighttime light intensity (p = 0.000). The HDDs and their change rates could be simulated well by the machine learning method. Their RMSEs were 564.08 °C * days and 3.59 °C * days * year−1, respectively. Our findings could support the scientific response to climate warming, the construction of living environments, sustainable development, etc.
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Chou, Huei-Chi, Tsai-Yuan Hsieh, Gwo-Tarng Sheu und Michael M. C. Lai. „Hepatitis Delta Antigen Mediates the Nuclear Import of Hepatitis Delta Virus RNA“. Journal of Virology 72, Nr. 5 (01.05.1998): 3684–90. http://dx.doi.org/10.1128/jvi.72.5.3684-3690.1998.
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ABSTRACT Hepatitis delta virus (HDV) RNA replicates in the nuclei of virus-infected cells. The mechanism of nuclear import of HDV RNA is so far unknown. Using a fluorescein-labeled HDV RNA introduced into partially permeabilized HeLa cells, we found that HDV RNA accumulated only in the cytoplasm. However, in the presence of hepatitis delta antigen (HDAg), which is the only protein encoded by HDV RNA, the HDV RNA was translocated into the nucleus, suggesting that nuclear import of HDV RNA is mediated by HDAg. Deletion of the nuclear localization signal (NLS) or RNA-binding motifs of HDAg resulted in the failure of nuclear import of HDV RNA, indicating that both the NLS and an RNA-binding motif of HDAg are required for the RNA-transporting activity of HDAg. Surprisingly, any one of the three previously identified RNA-binding motifs was sufficient to confer the RNA-transporting activity. We have further shown that HDAg, via its NLS, interacts with karyopherin α2 in vitro, suggesting that nuclear import of the HDAg-HDV RNA complex is mediated by the karyopherin α2β heterodimer. The nuclear import of HDV RNA may be the first biological function of HDAg in the HDV life cycle.
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Cho, Sung-Hwan, Hyeong-Jung Kim und M. Zaheeruddin. „Revised heating degree days due to global warming for 15 major cities of South Korea“. Building Services Engineering Research and Technology 32, Nr. 4 (13.05.2011): 377–83. http://dx.doi.org/10.1177/0143624411404752.
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Because of the rapid rise in ambient temperatures in urban cities due to global warming, this research study was conducted to revise the heating degree days (HDDs) for main cities of South Korea. Current HDDs used in the design of heating systems were established some 30 years ago. Therefore, there is a need to revisit and revise the HDDs used in Korea. The HDDs were computed at five different indoor set-point and unloaded temperatures. The validity of the methodology used for computing HDDs was ascertained by comparing the calculated HDDs with the published values. The impact of the length of time on total annual HDDs was examined. The results show that higher temperature trends due to global warming witnessed over the past decade in general decreased the HDDs. The impact was higher for warmer climate cities than the cold regions. The revised annual HDDs for 15 major cities of South Korea are presented in this paper. Practical applications: The HDDs corrected for global warming effects for 15 major cities of South Korea presented in this article are useful for designers in estimating the impact on equipment size and energy consumption. Towards this end, several scenarios of global warming effects are presented by assuming several unloaded temperature levels. This is useful for the designers in examining the uncertainties in the estimation of energy consumption. The results published are also important for policy makers in South Korea to examine the need for revising the degree day database in light of the global warming trends.
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Mantovani, Fiamma, Paola Massimi und Lawrence Banks. „Proteasome-mediated regulation of the hDlg tumour suppressor protein“. Journal of Cell Science 114, Nr. 23 (01.12.2001): 4285–92. http://dx.doi.org/10.1242/jcs.114.23.4285.
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The Dlg tumour suppressor protein is intimately involved in the control of cell contact and polarity. Previous studies have shown that hDlg is a target for a number of viral transforming proteins. In particular, the high risk human papillomavirus (HPV) E6 proteins target hDlg for proteasome-mediated degradation, an activity that appears to contribute to HPV-induced malignancy. However, little information is available concerning the normal regulation of hDlg. In this study we have investigated the role of the proteasome in the regulation of endogenous hDlg protein levels in epithelial cell lines. We demonstrate that hDlg is, indeed, degraded via the proteasome both in the presence and absence of HPV, in a fashion that is dependent on the ability of the cells to form cell junctions. By western blot and immunofluorescence analysis we show that hDlg is efficiently degraded in isolated cells; however, upon cell-cell contact, hDlg is both hyper-phosphorylated and stabilised. Strikingly, in both transformed rodent cells and undifferentiated cervical cancer cells, this ability to stabilise Dlg upon increased cell density is lost. These results demonstrate a complex pattern of hDlg regulation by phosphorylation and proteasome degradation in response to cell contact. Loss of this regulation probably represents a significant step in the development of malignancy.