3,699 research outputs found
Spatiotemporal Analysis of COVID-19 Infection and Air Quality in India
COVID-19 infects the respiratory tract leading to lung damage. Air pollutants such as PM 2.5 is one of the main causes and aggravating factors of many respiratory diseases. A known COVID-19 and air pollution âhotspotâ is India. India reported a devastating number of COVID-19 cases in early 2020. As the country went into lockdown, the air quality improved significantly, providing a rare opportunity to study correlation between COVID-19 cases and air quality. The spatial autocorrelation analysis between the regions for air quality and COVID-19 cases revealed no significant clustering within the regions. Cross-correlation in time series and regression analysis established a positive correlation between PM2.5 emissions and COVID-19 deaths with a time lag of 20-60 days. Spatiotemporal correlation reveals that there is a positive correlation of PM 2.5 and COVID-19 deaths with time lag of 30-50 days and 300 kilometers
Identity, Language, and Education â A Case Study in Taiwan
The concept of identity as well as its construction process is a complex one. In order to better understand this concept of identity, the objective of this study was to look at the life history of one Taiwanese woman who has lived through three educational systems in Taiwan. Her life story, collected through multiple interviews, is examined for moments and experiences which depict her views on her identity, and later analyzed with particular attention to the relationship between identity, language and education. Her narratives show that her identities are fluid, context-dependent and multi-faceted; characteristics of identity which have been proposed by other researchers in their studies. Following analysis of the stories she tells, I
have identified three main identities that she holds and have attempted to show how education and language pertain to this identity. It appears that the role of education and language is important and definitely has influence on
an individualâs identity and also an individualâs ability to become a member of selected groups. However, it would be careless to disregard other factors,such as family and socio-political situations because often these factors can
be linked to language and education as well and have emerged from this study as also being influential factors
IN VITRO INTERACTION OF AMINOGLYCOSIDES AND BETA-LACTAM PENICILLINS
The aminoglycoside antibiotics are often used in combination with a f3-lactam antibiotic, to provide either a wider spectrum of activity against gram-negative bacilli or a synergistic antimicrobial effect against Pseudomonas aeruginosa and various enterobacteria.
In 1971, MacLaughlin & Reeves found that the combined use of gentamicin and carbenicillin resulted in an interaction and loss of activity of both antibiotics. Since then more studies, in vitro and in vivo, have been performed to study the effect of medium, temperature, concentration, time, pH
and different penicillin-aminoglycoside combinations on the interaction.
The purpose of this study was to investigate the kinetics of the interaction in vitro. Four different
concentrations of aminoglycosides (A) (5, 10, 15 & 20 pg/mL of gentamicin or tobramycin) and penicillins (P) (100, 200, 400 & 600 pg/mL of carbenicillin or ticarcillin) were incubated in plasma at 37°C for 3 days. Samples taken at 12 h intervals were analyzed for both aminoglycoside and
penicillin by radioimmunoassay and high pressure liquid chromatography, respectively.
Degradation of all four antibiotics in controls were first order reactions. The degradation of penicillins was faster than the aminoglycosides, with only 50% of the original concentration remaining at 24 h. In incubation mixtures, the rate of loss of penicillins was not significantly different from the controls and still appeared as a first order reaction. The interaction did not contribute significantly to the loss of penicillin. However, the rate of loss of aminoglycosides was greater than in controls and appeared as a second order reaction dependent on the concentration of both penicillin and aminoglycoside. The loss of aminoglycoside was due to its degradation in plasma and its interaction with penicillin.
The degradation constants of penicillins (Kp) were calculated as dP/dt = -K PP and averaged 1.8 x 10
-2 h -1 for carbenicillin and 2.6 x 10 -2 h -1 for ticarcillin in controls and averaged 2.2 x 10 -2 h -1
for carbenicillin and 3.0 x 10 -2 h -1 for ticarcillin in antibiotic mixtures. In both controls and mixtures, the time required for loss of 50% of initial analyzed concentration (t50) was 30 & 55% larger, for carbenicillin and ticarcillin respectively, at higher penicillin concentrations of 400 & 600 ”g/mL compared to lower penicillin concentrations of 100 & 200 ”g/mL.
The degradation constants of aminoglycosides (KA) in controls were calculated as dA/dt = -K A A and averaged 0.9 x 10 -3 h -1 for gentamicin and 1.2 x 10 -3 h -1 for tobramycin. The degradation constants of aminoglycosides in antibiotic mixtures and the interaction rate constants (K.) were determined by computer fitting of the aminoglycoside concentrations in incubation mixtures to a model incorporating a second order loss of aminoglycoside and a first order loss of penicillin from the mixtures. The degradation constants of aminoglycosides in antibiotic mixture were less than 1 x 10 -8 h -1 . The t 50 values of aminoglycosides in antibiotic mixtures were shorter than in controls (> 25 days) and were related to the concentration of penicillin. The t50 values of aminoglycosides were longer than 72 h at a penicillin concentration of 100 ”g/mL. As the concentration of penicillin
became higher, the t50 values became shorter and were less than 10 h for a penicillin concentration of 600 ”g/mL.
The interaction rate constants averaged 2.2 x 10-4 mL/”gxh and 1.6 x 10 -4 mL/”gxh for both carbenicillin and ticarcillin interactions with gentamicin and tobramycin, respectively. The "effective" interaction rate constants (K. x P) were larger for the higher penicillin concentrations. Examination of both the t 50 values of aminoglycosides and the K. indicated that there was no significant difference
between the interaction rate produced by carbenicillin and ticarcillin and gentamicin was inactivated more by carbenicillin and ticarcillin than tobramycin.
The effect of the interaction in vivo was examined by computer simulation using the kinetic parameters determined in vitro. The interaction of penicillin and aminoglycoside would be significant in patients with impaired renal function and might be significant in patients with normal renal function
when the concentration of penicillin is very high
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An Extended Culture System that Supports Human Primordial Germ Cell-like Cell Survival and Initiation of DNA Methylation Erasure.
The development of an in vitro system in which human primordial germ cell-like cells (hPGCLCs) are generated from human pluripotent stem cells (hPSCs) has been invaluable to further our understanding of human primordial germ cell (hPGC) specification. However, the means to evaluate the next fundamental steps in germ cell development have not been well established. In this study we describe a two dimensional extended culture system that promotes proliferation of specified hPGCLCs, without reversion to a pluripotent state. We demonstrate that hPGCLCs in extended culture undergo partial epigenetic reprogramming, mirroring events described in hPGCs in vivo, including a genome-wide reduction in DNA methylation and maintenance of depleted H3K9me2. This extended culture system provides a new approach for expanding the number of hPGCLCs for downstream technologies, including transplantation, molecular screening, or possibly the differentiation of hPGCLCs into gametes by in vitro gametogenesis
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Prediction of progression in idiopathic pulmonary fibrosis using CT scans atbaseline: A quantum particle swarm optimization - Random forest approach
Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease characterized by an unpredictable progressive declinein lung function. Natural history of IPF is unknown and the prediction of disease progression at the time ofdiagnosis is notoriously difficult. High resolution computed tomography (HRCT) has been used for the diagnosisof IPF, but not generally for monitoring purpose. The objective of this work is to develop a novel predictivemodel for the radiological progression pattern at voxel-wise level using only baseline HRCT scans. Mainly, thereare two challenges: (a) obtaining a data set of features for region of interest (ROI) on baseline HRCT scans andtheir follow-up status; and (b) simultaneously selecting important features from high-dimensional space, andoptimizing the prediction performance. We resolved the first challenge by implementing a study design andhaving an expert radiologist contour ROIs at baseline scans, depending on its progression status in follow-upvisits. For the second challenge, we integrated the feature selection with prediction by developing an algorithmusing a wrapper method that combines quantum particle swarm optimization to select a small number of featureswith random forest to classify early patterns of progression. We applied our proposed algorithm to analyzeanonymized HRCT images from 50 IPF subjects from a multi-center clinical trial. We showed that it yields aparsimonious model with 81.8% sensitivity, 82.2% specificity and an overall accuracy rate of 82.1% at the ROIlevel. These results are superior to other popular feature selections and classification methods, in that ourmethod produces higher accuracy in prediction of progression and more balanced sensitivity and specificity witha smaller number of selected features. Our work is the first approach to show that it is possible to use onlybaseline HRCT scans to predict progressive ROIs at 6 months to 1year follow-ups using artificial intelligence
Chromatin Laser Imaging Reveals Abnormal Nuclear Changes for Early Cancer Detection
We developed and applied rapid scanning laser-emission microscopy to detect
abnormal changes in cell nuclei for early diagnosis of cancer and cancer
precursors. Regulation of chromatins is essential for genetic development and
normal cell functions, while abnormal nuclear changes may lead to many
diseases, in particular, cancer. The capability to detect abnormal changes in
apparently normal tissues at a stage earlier than tumor development is critical
for cancer prevention. Here we report using LEM to analyze colonic tissues from
mice at-risk for colon cancer by detecting prepolyp nuclear abnormality. By
imaging the lasing emissions from chromatins, we discovered that, despite the
absence of observable lesions, polyps, or tumors under stereoscope, high-fat
mice exhibited significantly lower lasing thresholds than low-fat mice. The low
lasing threshold is, in fact, very similar to that of adenomas and is caused by
abnormal cell proliferation and chromatin deregulation that can potentially
lead to cancer. Our findings suggest that conventional methods, such as
colonoscopy, may be insufficient to reveal hidden or early tumors under
development. We envision that this work will provide new insights into LEM for
early tumor detection in clinical diagnosis and fundamental biological and
biomedical research of chromatin changes at the biomolecular level of cancer
development
Perception of voice use and problems in female singers and broadcasters an impairment, activity limitation and participation restriction perspective
Also available in print."A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, May 4, 2001."Thesis (B.Sc)--University of Hong Kong, 2001published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science
Maine Distributed Solar Valuation Study
During its 2014 session, the Maine Legislature enacted an Act to Support Solar Energy Development in Maine. P.L Chapter 562 (April 24, 2014) (codified at 35âA M.R.S. §§ 3471â3473) (âActâ). Section 1 of the Act contains the Legislative finding that it is in the public interest is to develop renewable energy resources, including solar energy, in a manner that protects and improves the health and wellâbeing of the citizens and natural environment of the State while also providing economic benefits to communities, ratepayers and the overall economy of the State.
Section 2 of the Act requires the Public Utilities Commission (Commission) to determine the value of distributed solar energy generation in the State, evaluate implementation options, and to deliver a report to the Legislature. To support this work, the Commission engaged a project team comprising Clean Power Research (Napa, California), Sustainable Energy Advantage (Framingham, Massachusetts), Pace Energy and Climate Center at the Pace Law School (White Plains, New York), and Dr. Richard Perez (Albany, New York).
Under the project, the team developed the methodology under a Commissionârun stakeholder review process, conducted a valuation on distributed solar for three utility territories, and developed a summary of implementation options for increasing deployment of distributed solar generation in the State.
The report includes three volumes which accompany this Executive Summary: Volume I Methodology; Volume II Valuation Results; Volume III Implementation Options
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