230 research outputs found

    Impact of Pavement Surface Condition on Roadway Departure Crash Risk in Iowa

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    Safety performance is a crucial component of highway network performance evaluation. Besides their devastating impact on roadway users, traffic crashes lead to substantial economic losses on both personal and societal levels. Due to the complexity of crash events and the unique conditions in each country and state, empirical local calibration for the correlation between attributes of interest and the safety performance is always recommended. Limited studies have established a procedure to analyze the impact of pavement condition on traffic safety in a risk analysis scheme. This study presents a thorough analysis of some roadway departure crashes which occurred in Iowa between 2006 and 2016. All crash records were mapped onto one-mile segments with known traffic volume (i.e., AADT), posted speed limits (SL), skid numbers (SN), ride qualities (IRI), and rut depths (RD) in a geographic information system (GIS) database. The crash records were correlated to the pavement surface condition (i.e., SN, IRI, and RD) using negative binomial regression models. Moreover, a novel risk analysis framework is introduced to perform crash risk assessment and evaluate the possible consequences for a given combination of events. The analysis shows a significant impact of pavement skid resistance on roadway-departure crashes under all accident conditions and severities. Risk analysis will facilitate coordination between the pavement management system and safety management system in the future, which will help with optimizing the overall highway network performance

    Towards Wind Energy-based Charging Stations: A Review of Optimization Methods

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    Due to the growing importance of renewable sources in sustainable energy systems, the strategic deployment of robust optimization techniques plays a crucial role in the design of Electric Vehicle Charging Stations (EVCSs). These stations need to smoothly incorporate renewable sources, ensuring optimal energy utilization. This study provides a comprehensive overview of the methodologies and approaches employed in the enhancement of wind energy based EVCSs. The aim is to discern the most efficacious techniques for optimizing charging stations. Researchers engage diverse strategies and methodologies in the realm of sizing and optimization, encompassing a spectrum of algorithmic implementations and software solutions. Evidently, each algorithm or software application bears distinctive merits and demerits. Singular reliance on a solitary algorithm or software for charging utility optimization is discerned to be potentially limiting. The investigation reveals that achieving better results in Electric Vehicle Charging Station (EVCS) optimization is facilitated by the collaborative use of multiple algorithms like GA, PSO, and ACO, among others, or software tools like Homer or RETScreen

    Genotypic detection of extended spectrum beta lactamases from selected bacterial isolates in the Specialist Hospital Sokoto, Nigeria

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    There are numerous reported cases of extended spectrum beta lactamases (ESBLs) producing Enterobacteriaceae in Nigeria, with little effort done on the molecular detection. Epidemiological studies around the world have investigated the prevalence of ESBL-producing enterobacteriaceae and they have seen multiple mechanisms of drug-resistance. Our study was designed to detect ESBLs genes such as CTX-M, SHV, and TEM using PCR from clinical isolates in a tertiary hospital in Sokoto metropolis. Clinical isolates from the Microbiology laboratory of the tertiary hospital was collected for 3 months. These isolates were identified using standard microbiological methods. They were tested against 8 antibiotics using the modified Kirby Bauer disc diffusion method. Multidrug resistant isolates were screened for ESBL production, and further confirmed by the Double Disc Synergy Test (DDST). Genotypic confirmation was carried out using multiplex Polymerase Chain Reaction (PCR). A total of 47 isolates made up of 21 E. coli (44.6%), 13 Klebsiella spp (27.6%), 7 Salmonella spp (14.9%), 5 Proteus mirabilis (10.6%), and 1 Enterobacter spp (2.1%) were obtained from urine, stool, and wound swab. Out of the 47 isolates, (45) 95.7% were multidrug resistant. Twenty-five (53.2%) were potential ESBL producers, while only 5 (20.0%) were confirmed phenotypically using a DDST. PCR results revealed 4 out of 5 of the isolates were possessing ESBL genes. It also revealed that 3 isolates co-produce TEM and SHV at 403bp and 293bp respectively. Only 1 isolate produced CTX-M gene at 569bp. The prevalence of ESBL production in the Gram negative enterobacteriaceae in our study did not indicate a high prevalence as reported by some studies in Sokoto and Northwest Nigeria.Keywords: Molecular detection, ESBLs, Clinical isolates, PC

    HIV envelope protein gp120-induced apoptosis in lung microvascular endothelial cells by concerted upregulation of EMAP II and its receptor, CXCR3

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    Chronic lung diseases, such as pulmonary emphysema, are increasingly recognized complications of infection with the human immunodeficiency virus (HIV). Emphysema in HIV may occur independent of cigarette smoking, via mechanisms that are poorly understood but may involve lung endothelial cell apoptosis induced by the HIV envelope protein gp120. Recently, we have demonstrated that lung endothelial apoptosis is an important contributor to the development of experimental emphysema, via upregulation of the proinflammatory cytokine endothelial monocyte-activating polypeptide II (EMAP II) in the lung. Here we investigated the role of EMAP II and its receptor, CXCR3, in gp120-induced lung endothelial cell apoptosis. We could demonstrate that gp120 induces a rapid and robust increase in cell surface expression of EMAP II and its receptor CXCR3. This surface expression occurred via a mechanism involving gp120 signaling through its CXCR4 receptor and p38 MAPK activation. Both EMAP II and CXCR3 were essentially required for gp120-induced apoptosis and exposures to low gp120 concentrations enhanced the susceptibility of endothelial cells to undergo apoptosis when exposed to soluble cigarette smoke extract. These data indicate a novel mechanism by which HIV infection causes endothelial cell loss involved in lung emphysema formation, independent but potentially synergistic with smoking, and suggest therapeutic targets for emphysema prevention and/or treatment

    Inhibitory Immune Checkpoint Receptors and Ligands as Prognostic Biomarkers in COVID-19 Patients.

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    Coronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2. During T-cell activation, the immune system uses different checkpoint pathways to maintain co-inhibitory and co-stimulatory signals. In COVID-19, expression of immune checkpoints (ICs) is one of the most important manifestations, in addition to lymphopenia and inflammatory cytokines, contributing to worse clinical outcomes. There is a controversy whether upregulation of ICs in COVID-19 patients might lead to T-cell exhaustion or activation. This review summarizes the available studies that investigated IC receptors and ligands in COVID-19 patients, as well as their effect on T-cell function. Several IC receptors and ligands, including CTLA-4, BTLA, TIM-3, VISTA, LAG-3, TIGIT, PD-1, CD160, 2B4, NKG2A, Galectin-9, Galectin-3, PD-L1, PD-L2, LSECtin, and CD112, were upregulated in COVID-19 patients. Based on the available studies, there is a possible relationship between disease severity and increased expression of IC receptors and ligands. Overall, the upregulation of some ICs could be used as a prognostic biomarker for disease severity. [Abstract copyright: Copyright © 2022 Al-Mterin, Alsalman and Elkord.

    In Vitro Antimicrobial Activity of The Filtrate Crude Extract Produced by Aspergillus niger

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    Introduction: Aspergillus niger represents one of the fungi that can produce the secondary metabolites, including antimicrobial agents, industrial and biotechnological products. Methodology: A. niger was tested against Candida albicans on the same petri dish of potato dextrose agar at room temperature. A. niger was cultured in potato dextrose broth at 2

    In Vitro Antimicrobial Activity of The Filtrate Crude Extract Produced by Aspergillus niger

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    Introduction: Aspergillus niger represents one of the fungi that can produce the secondary metabolites, including antimicrobial agents, industrial and biotechnological products. Methodology: A. niger was tested against Candida albicans on the same petri dish of potato dextrose agar at room temperature. A. niger was cultured in potato dextrose broth at 27 °C for 7 days. The fungal filtrate was separated from mycelia, and the filtrate was extracted for getting a crude blackish-brown extract. The GC-MS analysis used to identify the constituents of the extract. Results: The filtrate crude extract of A. niger exhibited the antimicrobial effects against Staphylococcus aureus, Streptococcus mutans, Escherichia coli, and Candida albicans.GC-MS analysis revealed that the extract contains [(5-methyl-2-phenylindolizine), (thiocarbamic acid, N,N-dimethyl, S-1,3-diphenyl-2-butenyl ester) and (22-beta.-acetoxy-3.beta.,16.alpha.-dihydroxy-13,28epoxyolean-2)].The extract had the toxic effect on a solution of the human red blood cells by using 300 µL of 10 mg/ml after 5 minutes while 100 µL and 200 µL of the same concentration did not appear the toxic effects during 1 hour of the testing time period. Conclusions: The extract of A. niger has the ability to produce the antimicrobial activity, so it very needs to separate its constituents into pure compounds for elucidating their chemical structure by using techniques of spectrometry. Then, the compounds can be separately testing against microbial pathogens, human normal cell to determine half lethal concentration (LC50)), and application of other biological tests such as test of LD50. Finally, the identified and purified compounds will be tested by volunteers in order to identify the side effects and toxicity of these compounds to be implemented as drugs for treating diseases in the hospitals
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