614 research outputs found
Optimizing an Adaptive Neuro-Fuzzy Inference System for Spatial Prediction of Landslide Susceptibility Using Four State-of-the-art Metaheuristic Techniques.
Four state-of-the-art metaheuristic algorithms including the genetic algorithm (GA), particle swarm optimization (PSO), differential evolutionary (DE), and ant colony optimization (ACO) are applied to an adaptive neuro-fuzzy inference system (ANFIS) for spatial prediction of landslide susceptibility in Qazvin Province (Iran). To this end, the landslide inventory map, composed of 199 identified landslides, is divided into training and testing landslides with a 70:30 ratio. To create the spatial database, thirteen landslide conditioning factors are considered within the geographic information system (GIS). Notably, the spatial interaction between the landslides and mentioned conditioning factors is analyzed by means of frequency ratio (FR) theory. After the optimization process, it was shown that the DE-based model reaches the best response more quickly than other ensembles. The landslide susceptibility maps were developed, and the accuracy of the models was evaluated by a ranking system, based on the calculated area under the receiving operating characteristic curve (AUROC), mean absolute error, and mean square error (MSE) accuracy indices. According to the results, the GA-ANFIS with a total ranking score (TRS) = 24 presented the most accurate prediction, followed by PSO-ANFIS (TRS = 17), DE-ANFIS (TRS = 13), and ACO-ANFIS (TRS = 6). Due to the excellent results of this research, the developed landslide susceptibility maps can be applied for future planning and decision making of the related area
Effects of temperature on hematological and histopathological changes and survival rate of juvenile Fenneropenaeus vannamei experimentally challenged to White Spot Virus
Many shrimp farmers were suffering from White Spot Disease (WSD) onset in last decades. Oscillation of environmental factors could lead mortality in susceptible hosts. Our study was aimed to investigate the effect of different temperatures on juvenile Fenneropenaeus vannamei experimentally exposed to White Spot Virus (WSV). Five hundred and forty juveniles were distributed among 3 treatments in triplicates, 22, 25 and 30°C and experimentally WSV were injected in the shrimps. Our results showed mortality started at 36 h post inoculation (hpi) in the treatment at 25°C (T25), meanwhile the mean value of mortality percent at 54 hpi in T25 (71.10±17.35) showed the significant difference (p=.045) with T22 (3.33±3.33) and T30 (Not Observed, NO.). Our results suggest that in site selection, in primary stage of farm designing, water temperature at more than 29°C, should be considered as key environmental factor. This finding can lead us that why the White Spot Disease occurred with high mortality in some area when the days of shrimp culture were prolonged until mid autumn
Effects of aflatoxin B1 on growth performance, health indices, phagocytic activity and histopathological alteration in Fenneropenaeus indicus
Mycotoxins contamination of feedstuff for aquatic animals is common in regions with humid tropical conditions. In this study Indian white shrimp, Fenneropenaeus indicus, (11.79 ± 1.76 g) were fed with diets containing 0, 20, 50, 100, 200, 400, 800 and 1600 ppb levels of aflatoxin B1 (AFLB1) for 8 weeks. Final weight, aflatoxin B1 residue (2-week intervals), Total Hemocyte Count (THC), Total Plasma Protein (TPP), Phagocytic Activity (PA), Survival rate (4-week intervals) were determined. Histopathological alterations in hepatopancreas, midgut and muscle tissues were studied at the end of 4 and 8 weeks. Shrimps fed with the 1600, 800 and 400 ppb concentrations of AFLB1 exhibited slow growth, and more reddish discoloration disseminated over the body at 4th week. Growth parameters, survival rate and health indices (THC, TPP) of F. indicus, are affected by the different doses of AFLB1 in diets. At the end of 8th week, doses of AFLB1 in the diets showed negative correlation to final weight, survival rate, THC and TPP (r = - 0.312, -0.603, -0.237 and - 0.649 at P<0.001, respectively). Moreover, significant histopathological alterations in the hepatopancreas, midgut and muscle tissues of exposed shrimps to different levels of AFLB1 were observed and these alterations are obviously indicated by changes in the health indexes (THC and TPP)
Effect of hot-water extract of brown seaweed Sargassum glaucescens via immersion route on immune responses of Fenneropenaeus indicus
The development of shrimp aquaculture, in spite of its global necessity, is largely at stake as significant ecological and pathological problems are increasing in the vast majority of the shrimp producing countries. Shrimp immunology is a key element in establishing strategies for controlling diseases in shrimp aquaculture. The total haemocyte count (THC), differential haemocyte count (DHC), total plasma protein (TPP), Phagocytic activity (PA), bacterial clearance efficiency (BCE) and bactericidal activity (BE) were examined when the F. indicus shrimps (11.32±1.20 g) were immersed in seawater (39 ppt and 25 ± 1 ºC) containing hot-water extracts of brown alga Sargassum glaucescens at 100, 300 and 500 mg/l. These parameters increased significantly (p < 0.05) when the shrimp were immersed in seawater containing hot-water extracts at 100 mg/l after 3h and 300 and 500 mg/l after 2 h. F. indicus shrimps that were immersed in hot-water extracts at 300 and 500 mg/l had increased phagocytic activity and clearance efficiency to Vibrio spp. after 2 hours. But bactericidal activity increased significantly after 1 hour in the same concentrations
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Deamidation of the human eye lens protein γS-crystallin accelerates oxidative aging
Cataract, a clouding of the eye lens from protein precipitation, affects millions of people every year. The lens proteins, the crystallins, show extensive post-translational modifications (PTMs) in cataractous lenses. The most common PTMs, deamidation and oxidation, promote crystallin aggregation; however, it is not clear precisely how these PTMs contribute to crystallin insolubilization. Here, we report six crystal structures of the lens protein γS-crystallin (γS): one of the wild-type and five of deamidated γS variants, from three to nine deamidation sites, after sample aging. The deamidation mutations do not change the overall fold of γS; however, increasing deamidation leads to accelerated disulfide-bond formation. Addition of deamidated sites progressively destabilized protein structure, and the deamidated variants display an increased propensity for aggregation. These results suggest that the deamidated variants are useful as models for accelerated aging; the structural changes observed provide support for redox activity of γS-crystallin in the lens
Epidemiologic characteristics of orthopedic surgical site infections and under-reporting estimation of registries using capture-recapture analysis
Background: Surgical Site Infections (SSIs) are among the leading causes of the postoperative complications. This study aimed at investigating the epidemiologic characteristics of orthopedic SSIs and estimating the under-reporting of registries using the capture-recapture method. Methods: This study, which was a registry-based, cross-sectional one, was conducted in six educational hospitals in Tehran during a one-year period, from March, 2017 to March, 2018. The data were collected from two hospital registries (National Nosocomial Infection Surveillance System (NNIS) and Health Information Management database (HIM)). First, all orthopedic SSIs registered in these sources were used to perform capture-recapture (N = 503). Second, 202 samples were randomly selected to assess patients` characteristics. Results: Totally, 76.24 of SSIs were detected post-discharge. Staphylococcus aureus (11.38) was the most frequently detected bacterium in orthopedic SSIs. The median time between the detection of a SSI and the discharge was 17 days. The results of a study done on 503 SSIs showed that the coverage of NNIS and HIM was 59.95 and 65.17, respectively. After capture-recapture estimation, it was found that about 221 of orthopedic SSIs were not detected by two sources among six hospitals and the real number of SSIs were estimated to be 623 ± 36.58 (95 CI, 552�695) and under-reporting percentage was 63.32. Conclusion: To recognize the trends of SSIs mortality and morbidity in national level, it is significant to have access to a registry with minimum underestimated data. Therefore, according to the weak coverage of NNIS and HIM among Iranian hospitals, a plan for promoting the national Infection Prevention and Control (IPC) programs and providing updated protocols is recommended. © 2021, The Author(s)
A simple vapor-diffusion method enables protein crystallization inside the HARE serial crystallography chip
Fixed-target serial crystallography has become an important method for the study of protein structure and dynamics at synchrotrons and X-ray free-electron lasers. However, sample homogeneity, consumption and the physical stress on samples remain major challenges for these high-throughput experiments, which depend on high-quality protein microcrystals. The batch crystallization procedures that are typically applied require time- and sample-intensive screening and optimization. Here, a simple protein crystallization method inside the features of the HARE serial crystallography chips is reported that circumvents batch crystallization and allows the direct transfer of canonical vapor-diffusion conditions to in-chip crystallization. Based on conventional hanging-drop vapor-diffusion experiments, the crystallization solution is distributed into the wells of the HARE chip and equilibrated against a reservoir with mother liquor. Using this simple method, high-quality microcrystals were generated with sufficient density for the structure determination of four different proteins. A new protein variant was crystallized using the protein concentrations encountered during canonical crystallization experiments, enabling structure determination from ∼55 µg of protein. Additionally, structure determination from intracellular crystals grown in insect cells cultured directly in the features of the HARE chips is demonstrated. In cellulo crystallization represents a comparatively unexplored space in crystallization, especially for proteins that are resistant to crystallization using conventional techniques, and eliminates any need for laborious protein purification. This in-chip technique avoids harvesting the sensitive crystals or any further physical handling of the crystal-containing cells. These proof-of-principle experiments indicate the potential of this method to become a simple alternative to batch crystallization approaches and also as a convenient extension to canonical crystallization screens
The national rate of intensive care units-acquired infections, one-year retrospective study in Iran
Background: Hospital-acquired infections (HAIs) in intensive care units (ICUs) are among the avoidable morbidity and mortality causes. This study aimed at investigating the rate of ICU-acquired infections (ICU-AIs) in Iran. Methods: For the purpose of this multi-center study, the rate of ICU-AIs calculated based on the data collected through Iranian nosocomial infections surveillance system and hospital information system. The data expanded based on 12 months of the year (13,632 records in terms of �hospital-ward-month�), and then, the last observation carried forward method was used to replace the missing data. Results: The mean (standard deviation) age of 52,276 patients with HAIs in the ICUs was 47.37 (30.78) years. The overall rate of ICU-AIs was 96.61 per 1000 patients and 16.82 per 1000 patient-days in Iran�s hospitals. The three main HAIs in the general ICUs were ventilator-associated events (VAE), urinary tract infection (UTI), and pneumonia events & lower respiratory tract infection (PNEU & LRI) infections. The three main HAIs in the internal and surgical ICUs were VAE, UTI, and bloodstream infections/surgical site infections (BSI/SSI). The most prevalent HAIs were BSI, PNEU & LRI and eye, ear, nose, throat, or mouth (EENT) infections in the neonatal ICU and PNEU & LRI, VAE, and BSI in the PICU. Device, catheter, and ventilator-associated infections accounted for 60.96, 18.56, and 39.83 of ICU-AIs, respectively. The ventilator-associated infection rate was 26.29 per 1000 ventilator-days. Based on the Pabon Lasso model, the lowest rates of ICU-AIs (66.95 per 1000 patients and 15.19 patient-days) observed in zone III, the efficient area. Conclusions: HAIs are common in the internal ICU wards. In fact, VAE and ventilator-related infections are more prevalent in Iran. HAIs in the ICUs leads to an increased risk of ICU-related mortality. Therefore, to reduce ICU-AIs, the specific and trained personnel must be responsible for the use of the devices (catheter use and ventilators), avoid over use of catheterization when possible, and remove catheters earlier. © 2021, The Author(s)
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