1,772 research outputs found
PM2.5 Pollution and Temperature Inversions: A Case Study in St. Louis, MO
Wintertime temperature inversions are partially responsible for some of the worst historical air pollution events as cold air pools are favorable for prolonged poor air quality episodes. The St. Louis metropolitan area in Missouri-Illinois has relevant problems with particulate pollution yet is under-studied. This case study examines the characteristics of an inversion layer along with additional meteorological parameters and their effects on PM2.5 air quality in St. Louis from November 22 to December 3, 2015. During the selected period, November 26 to December 1 PM2.5 Air Quality Index (AQI) daily values often exceeded levels the Environmental Protection Agency classifies as unhealthy for sensitive groups. Shallow surface temperature inversions were most common on less polluted days while strong temperature inversions with a base height around 950 mb persisted on more heavily polluted days. Variability in surface wind speed, wind direction, and relative humidity occurred mostly on less polluted days while values were consistent on more heavily polluted days. Precipitation only happened on the most heavily polluted days but showed no great impact of reducing pollution. Winds from the south on November 26 suggested transport of excess particulate pollutant was the cause of unhealthy PM2.5 levels that day, not temperature inversions. Strong temperature inversions contained these pollutants in St. Louis on November 27 to November 30. A surface pressure minimum north of St. Louis on December 1 produced a substantial change in wind direction on November 30, influencing eventual dispersion of pollutants. Further research is necessary to help fill in the knowledge gaps about air quality in the Midwest
Inferences on Criminality Based on Appearance
In our research study, we tested whether people can tell if someone is a criminal or not based on a photograph of their face. The importance of the subject lies in the fact that many people are unfairly judged as criminals based on stereotypes such as race. In this study, we wished to eliminate race and see if any purely facial characteristics are stereotypically defined as criminal or if a personās initial judgment is an accurate predictor of someoneās character. Extensive research has been dedicated to finding if people have facial features that portray some characteristic about them and this study will focus on criminality. Through the use of a face modulating program, neutral faced photographs were shown to participants with a question that asked if the person in the photograph is a criminal or not. The data gathered will be beneficial in either identifying facial features that are associated with criminals or that show the interesting phenomena of gut instinct
Exploring the effects of various growth conditions on gene expression of mechanosensitive ion channels in Escherichia coli
In rapidly changing environmental conditions, bacterial mechanosensitive ion channels are responsible for ensuring cell survival. Bacterial mechanosensitive channels gate in response to membrane tension in order to relieve intracellular pressure, prior to cell lysis. The most well-studied bacterial mechanosensitive channels include the mechanosensitive channel of large (MscL) and small (MscS) conductance from Escherichia coli (E. coli), both of which gate in response to tension. In E. coli, there are seven mechanosensitive ion channel genes: MscL, MscS, and five additional genes that are members of the MscS superfamily. Of these seven genes, six have been shown to gate directly in response to tension applied to the cellular membrane. We determine each channelās expression in varying growth conditions like salt concentration, pH, and temperature. To determine each geneās contribution to survival, we utilized qPCR and compared mRNA levels of each individual channel to a standard ribosomal gene, RpoB, within each growth condition. The relative expression of each channel provides insight into the specific roles that each of these channels fulfills during the survival response of the cell. Throughout our data, we see that MscL plays an active role in cell survival across various conditions. We rarely see any indication of YnaI expression, with the exception of cells cultured at lower temperatures. Apart from these channels, we observe similarities in expression levels between MscS, MscM, and YbdG as well as between MscK and YbiO across various conditions. This research shows that the expression of mechanosensitive channels fluctuates based on the growth environment
Further generalization of symmetric multiplicity theory to the geometric case over a field
0751964. Further, this work was carried out within the activities of CMA/FCT/UNL and it was partially supported by the Fundacao para a Ciencia e a Tecnologia (Portuguese Foundation for Science and Technology) through the project UIDB/00297/2020.Using the recent geometric Parter-Wiener, etc. theorem and related results, it is shown that much of the multiplicity theory developed for real symmetric matrices associated with paths and generalized stars remains valid for combinatorially symmetric matrices over a field. A characterization of generalized stars in the case of combinatorially symmetric matrices is given.publishersversionpublishe
A Thermodynamic-Based Interpretation of Protein Expression Heterogeneity in Different Glioblastoma Multiforme Tumors Identifies Tumor-Specific Unbalanced Processes
We describe a thermodynamic-motivated, information theoretic analysis of proteomic data collected from a series of 8 glioblastoma multiforme (GBM) tumors. GBMs are considered here as prototypes of heterogeneous cancers. That heterogeneity is viewed here as manifesting in different unbalanced biological processes that are associated with thermodynamic-like constraints. The analysis yields a molecular description of a stable steady state that is common across all tumors. It also resolves molecular descriptions of unbalanced processes that are shared by several tumors, such as hyperactivated phosphoprotein signaling networks. Further, it resolves unbalanced processes that provide unique classifiers of tumor subgroups. The results of the theoretical interpretation are compared against those of statistical multivariate methods and are shown to provide a superior level of resolution for identifying unbalanced processes in GBM tumors. The identification of specific constraints for each GBM tumor suggests tumor-specific combination therapies that may reverse this imbalance
Identification of a novel transport system in Borrelia burgdorferi that links the inner and outer membranes
Borrelia burgdorferi, the spirochete that causes Lyme disease, is a diderm organism that is similar to Gram-negative organisms in that it contains both an inner and outer membrane. Unlike typical Gram-negative organisms, however, B. burgdorferi lacks lipopolysaccharide (LPS). Using computational genome analyses and structural modeling, we identified a transport system containing six proteins in B. burgdorferi that are all orthologs to proteins found in the lipopolysaccharide transport (LPT) system that links the inner and outer membranes of Gram-negative organisms and is responsible for placing LPS on the surface of these organisms. While B. burgdorferi does not contain LPS, it does encode over 100 different surface-exposed lipoproteins and several major glycolipids, which like LPS are also highly amphiphilic molecules, though no system to transport these molecules to the borrelial surface is known. Accordingly, experiments supplemented by molecular modeling were undertaken to determine whether the orthologous LPT system identified in B. burgdorferi could transport lipoproteins and/or glycolipids to the borrelial outer membrane. Our combined observations strongly suggest that the LPT transport system does not transport lipoproteins to the surface. Molecular dynamic modeling, however, suggests that the borrelial LPT system could transport borrelial glycolipids to the outer membrane
Locomotor muscle fatigue is not critically regulated after prior upper body exercise
This study examined the effects of prior upper body exercise on subsequent high-intensity cycling exercise tolerance and associated changes in neuromuscular function and perceptual responses. Eight men performed three fixed work-rate (85% peak power) cycling tests: 1) to the limit of tolerance (CYC); 2) to the limit of tolerance after prior high-intensity arm-cranking exercise (ARM-CYC); and 3) without prior exercise and for an equal duration as ARM-CYC (ISOTIME). Peripheral fatigue was assessed via changes in potentiated quadriceps twitch force during supramaximal electrical femoral nerve stimulation. Voluntary activation was assessed using twitch interpolation during maximal voluntary contractions. Cycling time during ARM-CYC and ISOTIME (4.33 Ā± 1.10 min) was 38% shorter than during CYC (7.46 Ā± 2.79 min) (P < 0.001). Twitch force decreased more after CYC (ā38 Ā± 13%) than ARM-CYC (ā26 Ā± 10%) (P = 0.004) and ISOTIME (ā24 Ā± 10%) (P = 0.003). Voluntary activation was 94 Ā± 5% at rest and decreased after CYC (89 Ā± 9%, P = 0.012) and ARM-CYC (91 Ā± 8%, P = 0.047). Rating of perceived exertion for limb discomfort increased more quickly during cycling in ARM-CYC [1.83 Ā± 0.46 arbitrary units (AU)/min] than CYC (1.10 Ā± 0.38 AU/min, P = 0.003) and ISOTIME (1.05 Ā± 0.43 AU/min, P = 0.002), and this was correlated with the reduced cycling time in ARM-CYC (r = ā0.72, P = 0.045). In conclusion, cycling exercise tolerance after prior upper body exercise is potentially mediated by central fatigue and intolerable levels of sensory perception rather than a critical peripheral fatigue limit
Association between purchase of over-the-counter medications and ovarian cancer diagnosis in the Cancer Loyalty Card Study (CLOCS):observational case-control study
BACKGROUND: Over-the-counter (OTC) medications are frequently used to self-care for nonspecific ovarian cancer symptoms prior to diagnosis. Monitoring such purchases may provide an opportunity for earlier diagnosis. OBJECTIVE: The aim of the Cancer Loyalty Card Study (CLOCS) was to investigate purchases of OTC pain and indigestion medications prior to ovarian cancer diagnosis in women with and without ovarian cancer in the United Kingdom using loyalty card data. METHODS: An observational case-control study was performed comparing purchases of OTC pain and indigestion medications prior to diagnosis in women with (n=153) and without (n=120) ovarian cancer using loyalty card data from two UK-based high street retailers. Monthly purchases of pain and indigestion medications for cases and controls were compared using the Fisher exact test, conditional logistic regression, and receiver operating characteristic (ROC) curve analysis. RESULTS: Pain and indigestion medication purchases were increased among cases 8 months before diagnosis, with maximum discrimination between cases and controls 8 months before diagnosis (Fisher exact odds ratio [OR] 2.9, 95% CI 2.1-4.1). An increase in indigestion medication purchases was detected up to 9 months before diagnosis (adjusted conditional logistic regression OR 1.38, 95% CI 1.04-1.83). The ROC analysis for indigestion medication purchases showed a maximum area under the curve (AUC) at 13 months before diagnosis (AUC=0.65, 95% CI 0.57-0.73), which further improved when stratified to late-stage ovarian cancer (AUC=0.68, 95% CI 0.59-0.78). CONCLUSIONS: There is a difference in purchases of pain and indigestion medications among women with and without ovarian cancer up to 8 months before diagnosis. Facilitating earlier presentation among those who self-care for symptoms using this novel data source could improve ovarian cancer patients' options for treatment and improve survival. TRIAL REGISTRATION: ClinicalTrials.gov NCT03994653; https://clinicaltrials.gov/ct2/show/NCT03994653
Drug-resistant Escherichia coli, Rural Idaho
Stool carriage of drug-resistant Escherichia coli in home-living residents of a rural community was examined. Carriage of nalidixic acidāresistant E. coli was associated with recent use of antimicrobial agents in the household. Household clustering of drug-resistant E. coli was observed. Most carriers of drug-resistant E. coli lacked conventional risk factors
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