265 research outputs found
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Waste tank ventilation system waste material accumulations
This paper calculates the amount of material that accumulates in the ventilation systems of various Tank Waste Remediation System facilities and estimates the amount of material that could be released due to a rapid pressurization
A Profile of Community Health Center Patients: Implications for Policy
Community health centers are a key source of comprehensive primary care in medically underserved communities across the country, and their role is expected to grow as health coverage expands under the Affordable Care Act (ACA). To sharpen understanding of the health center patient population, this brief compares it to the overall low-income population, using data from the Health Center Patient Survey and the National Health Interview Survey,respectively. The pre-ACA profile of health center patients that emerges sets the stage for measuring change following implementation of the reform law and can inform health center policy, planning, and assessment moving forward
Direct, biomimetic synthesis of (+)-artemone via a stereoselective, organocatalytic cyclization
We present a four-step synthesis of (+)-artemone from (â)- linalool, featuring iminium organocatalysis of a doubly diastereoselective conjugate addition reaction. The strategy follows a proposed biosynthetic pathway, rapidly generates stereochemical complexity, uses no protecting groups, and minimizes redox manipulations
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A Pest and Beneficial Insect Short Course Program for the Pacific Northwest: Train-the-trainer
Beyond Born-Mayer: Improved Models for Short-Range Repulsion in ab Initio Force Fields
Short-range repulsion
within intermolecular force fields is conventionally
described by either Lennard-Jones (<i>A</i>/<i>r</i><sup>12</sup>) or BornâMayer (<i>A</i> expÂ(â<i>Br</i>)) forms. Despite their widespread use, these simple functional
forms are often unable to describe the interaction energy accurately
over a broad range of intermolecular distances, thus creating challenges in the development of ab initio
force fields and potentially leading to decreased accuracy and transferability.
Herein, we derive a novel short-range functional form based on a simple
Slater-like model of overlapping atomic densities and an iterated
stockholder atom (ISA) partitioning of the molecular electron density.
We demonstrate that this SlaterâISA methodology yields a more
accurate, transferable, and robust description of the short-range
interactions at minimal additional computational cost compared to
standard Lennard-Jones or BornâMayer approaches. Finally, we
show how this methodology can be adapted to yield the standard BornâMayer
functional form while still retaining many of the advantages of the
Slater-ISA approach
New Angles on Standard Force Fields: Toward a General Approach for Treating Atomic-Level Anisotropy
Nearly all standard force fields
employ the âsum-of-spheresâ
approximation, which models intermolecular interactions purely in
terms of interatomic distances. Nonetheless, atoms in molecules can
have significantly nonspherical shapes, leading to interatomic interaction
energies with strong orientation dependencies. Neglecting this âatomic-level
anisotropyâ can lead to significant errors in predicting interaction
energies. Herein, we propose a simple, transferable, and computationally
efficient model (MASTIFF) whereby atomic-level orientation dependence
can be incorporated into ab initio intermolecular force fields. MASTIFF
includes anisotropic exchange-repulsion, charge penetration, and dispersion
effects, in conjunction with a standard treatment of anisotropic long-range
(multipolar) electrostatics. To validate our approach, we benchmark
MASTIFF against various sum-of-spheres models over a large library
of intermolecular interactions between small organic molecules. MASTIFF
achieves quantitative accuracy, with respect to both high-level electronic
structure theory and experiment, thus showing promise as a basis for
ânext-generationâ force field development
"Now he walks and walks, as if he didn't have a home where he could eat": food, healing, and hunger in Quechua narratives of madness
In the Quechua-speaking peasant communities of southern Peru, mental disorder is understood less as individualized pathology and more as a disturbance in family and social relationships. For many Andeans, food and feeding are ontologically fundamental to such relationships. This paper uses data from interviews and participant observation in a rural province of Cuzco to explore the significance of food and hunger in local discussions of madness. Carersâ narratives, explanatory models, and theories of healing all draw heavily from idioms of food sharing and consumption in making sense of affliction, and these concepts structure understandings of madness that differ significantly from those assumed by formal mental health services. Greater awareness of the salience of these themes could strengthen the input of psychiatric and psychological care with this population and enhance knowledge of the alternative treatments that they use. Moreover, this case provides lessons for the global mental health movement on the importance of openness to the ways in which indigenous cultures may construct health, madness, and sociality. Such local meanings should be considered by mental health workers delivering services in order to provide care that can adjust to the alternative ontologies of sufferers and carers
Comparison of RNA-Seq and Microarray Gene Expression Platforms for the Toxicogenomic Evaluation of Liver From Short-Term Rat Toxicity Studies
Gene expression profiling is a useful tool to predict and interrogate mechanisms of toxicity. RNA-Seq technology has emerged as an attractive alternative to traditional microarray platforms for conducting transcriptional profiling. The objective of this work was to compare both transcriptomic platforms to determine whether RNA-Seq offered significant advantages over microarrays for toxicogenomic studies. RNA samples from the livers of rats treated for 5 days with five tool hepatotoxicants (α-naphthylisothiocyanate/ANIT, carbon tetrachloride/CCl4, methylenedianiline/MDA, acetaminophen/APAP, and diclofenac/DCLF) were analyzed with both gene expression platforms (RNA-Seq and microarray). Data were compared to determine any potential added scientific (i.e., better biological or toxicological insight) value offered by RNA-Seq compared to microarrays. RNA-Seq identified more differentially expressed protein-coding genes and provided a wider quantitative range of expression level changes when compared to microarrays. Both platforms identified a larger number of differentially expressed genes (DEGs) in livers of rats treated with ANIT, MDA, and CCl4 compared to APAP and DCLF, in agreement with the severity of histopathological findings. Approximately 78% of DEGs identified with microarrays overlapped with RNA-Seq data, with a Spearmanâs correlation of 0.7 to 0.83. Consistent with the mechanisms of toxicity of ANIT, APAP, MDA and CCl4, both platforms identified dysregulation of liver relevant pathways such as Nrf2, cholesterol biosynthesis, eiF2, hepatic cholestasis, glutathione and LPS/IL-1 mediated RXR inhibition. RNA-Seq data showed additional DEGs that not only significantly enriched these pathways, but also suggested modulation of additional liver relevant pathways. In addition, RNA-Seq enabled the identification of non-coding DEGs that offer a potential for improved mechanistic clarity. Overall, these results indicate that RNA-Seq is an acceptable alternative platform to microarrays for rat toxicogenomic studies with several advantages. Because of its wider dynamic range as well as its ability to identify a larger number of DEGs, RNA-Seq may generate more insight into mechanisms of toxicity. However, more extensive reference data will be necessary to fully leverage these additional RNA-Seq data, especially for non-coding sequences
Mutual exclusivity of hyaluronan and hyaluronidase in invasive group A Streptococcus
A recent analysis of group A Streptococcus (GAS) invasive infections in Australia has shown a predominance of M4 GAS, a serotype recently reported to lack the antiphagocytic hyaluronic acid (HA) capsule. Here, we use molecular genetics and bioinformatics techniques to characterize 17 clinical M4 isolates associated with invasive disease in children during this recent epidemiology. All M4 isolates lacked HA capsule, and whole genome sequence analysis of two isolates revealed the complete absence of the hasABC capsule biosynthesis operon. Conversely, M4 isolates possess a functional HA-degrading hyaluronate lyase (HylA) enzyme that is rendered nonfunctional in other GAS through a point mutation. Transformation with a plasmid expressing hasABC restored partial encapsulation in wild-type (WT) M4 GAS, and full encapsulation in an isogenic M4 mutant lacking HylA. However, partial encapsulation reduced binding to human complement regulatory protein C4BP, did not enhance survival in whole human blood, and did not increase virulence of WT M4 GAS in a mouse model of systemic infection. Bioinformatics analysis found no hasABC homologs in closely related species, suggesting that this operon was a recent acquisition. These data showcase a mutually exclusive interaction of HA capsule and active HylA among strains of this leading human pathogen
Preclinical species gene expression database: Development and meta-analysis
The evaluation of toxicity in preclinical species is important for identifying potential safety liabilities of experimental medicines. Toxicology studies provide translational insight into potential adverse clinical findings, but data interpretation may be limited due to our understanding of cross-species biological differences. With the recent technological advances in sequencing and analyzing omics data, gene expression data can be used to predict cross species biological differences and improve experimental design and toxicology data interpretation. However, interpreting the translational significance of toxicogenomics analyses can pose a challenge due to the lack of comprehensive preclinical gene expression datasets. In this work, we performed RNA-sequencing across four preclinical species/strains widely used for safety assessment (CD1 mouse, Sprague Dawley rat, Beagle dog, and Cynomolgus monkey) in âŒ50 relevant tissues/organs to establish a comprehensive preclinical gene expression body atlas for both males and females. In addition, we performed a meta-analysis across the large dataset to highlight species and tissue differences that may be relevant for drug safety analyses. Further, we made these databases available to the scientific community. This multi-species, tissue-, and sex-specific transcriptomic database should serve as a valuable resource to enable informed safety decision-making not only during drug development, but also in a variety of disciplines that use these preclinical species
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