62 research outputs found
Scintillation in the Circinus Galaxy water megamasers
We present observations of the 22 GHz water vapor megamasers in the Circinus
galaxy made with the Tidbinbilla 70m telescope. These observations confirm the
rapid variability seen earlier by Greenhill et al (1997). We show that this
rapid variability can be explained by interstellar scintillation, based on what
is now known of the interstellar scintillation seen in a significant number of
flat spectrum AGN. The observed variability cannot be fully described by a
simple model of either weak or diffractive scintillation.Comment: 10 pages, 5 figures. AJ accepte
Assessment of Pharmacist Attitudes Regarding Introductory Pharmacy Practice Experience Hours
Introductory pharmacy practice experience (IPPE) hours are a means of integrating experiential education as a key role early on in pharmacy education. The Accreditation Council for Pharmacy Education (ACPE) has offered little guidance on mandatory and specific objectives to accomplish during IPPE hours, thus it is possible that preceptors do not feel adequately prepared, nor do they have a full understanding of what is required of them when they agree to precept an IPPE student. Given the lack of previous research conducted, the objective of this study was to obtain an understanding of the general attitude that preceptors have toward IPPE hours. A self-administered Internet-based questionnaire was completed by 100 respondents. The survey included multiple choice, Likert-type scale (1 =strongly disagree to 7 =strongly agree), sliding scale, and open-ended questions assessing preceptor\u27s knowledge of academic IPPE hour requirements, college of pharmacy expectations, time commitment and work site issues, expectations of the student, formality of IPPE hours, personal experience as a preceptor, an open-ended response and demographic information. Upon analyzing the data, researchers found that respondents presented with a generally positive attitude regarding IPPE hours (5.79 ± 1.03). Respondents expressed a desire to receive a zero to two hour online preceptor training (5.17 ± 1.25). In general, pharmacists indicated sufficient staffing to accommodate IPPE students (3.92 ± 1.38) and were undecided regarding monetary reimbursement (4.39 ± 1.53). Survey participants preferred receiving a guided checklist of activities for completion (S.45 ± 1.27), student resume (5.19 ± 1.30) and previous didactic course work (S.33 ± 1.41); however, survey participants expressed a desire for flexibility in determining the specifics of the experience (5.41 ± 1.11) while having students complete hours in a more concentrated time frame (5.19 ± 1.44). This exploratory research project was conducted to serve as baseline data to stimulate further investigation regarding IPPE hours
Motion analysis of match-play in elite U12 to U16 age-group soccer players
The aim of this study was to quantify the motion demands of match-play in elite U12 to U16 age-group soccer players. Altogether, 112 players from two professional soccer clubs at five age-group levels (U12–U16) were monitored during competitive matches (n=14) using a 5 Hz non-differential global positioning system (NdGPS). Velocity thresholds were normalized for each age-group using the mean squad times for a flying 10 m sprint test as a reference point. Match performance was reported as total distance, high-intensity distance, very high-intensity distance, and sprint distance. Data were reported both in absolute (m) and relative (m min-1) terms due to a rolling substitute policy. The U15 (1.35±0.09 s) and U16 (1.31±0.06 s) players were significantly quicker than the U12 (1.58±0.10 s), U13 (1.52±0.07 s), and U14 (1.51±0.08 s) players in the flying 10 m sprint test (P U12, U13, U14), high-intensity distance (U16 > U12, U13, U14, U15), very high-intensity distance (U16 4 U12, U13), and sprint distance (U16 > U12, U13) than their younger counterparts (P<0.05). When the data are considered relative to match exposure, few differences are apparent. Training prescription for youth soccer players should consider the specific demands of competitive match-play in each age-group
Natural micropolymorphism in human leukocyte antigens provides a basis for genetic control of antigen recognition
Human leukocyte antigen (HLA) gene polymorphism plays a critical role in protective immunity, disease susceptibility, autoimmunity, and drug hypersensitivity, yet the basis of how HLA polymorphism influences T cell receptor (TCR) recognition is unclear. We examined how a natural micropolymorphism in HLA-B44, an important and large HLA allelic family, affected antigen recognition. T cell–mediated immunity to an Epstein-Barr virus determinant (EENLLDFVRF) is enhanced when HLA-B*4405 was the presenting allotype compared with HLA-B*4402 or HLA-B*4403, each of which differ by just one amino acid. The micropolymorphism in these HLA-B44 allotypes altered the mode of binding and dynamics of the bound viral epitope. The structure of the TCR–HLA-B*4405EENLLDFVRF complex revealed that peptide flexibility was a critical parameter in enabling preferential engagement with HLA-B*4405 in comparison to HLA-B*4402/03. Accordingly, major histocompatibility complex (MHC) polymorphism can alter the dynamics of the peptide-MHC landscape, resulting in fine-tuning of T cell responses between closely related allotypes
Gene expression profiling reveals differential effects of sodium selenite, selenomethionine, and yeast-derived selenium in the mouse
The essential trace mineral selenium is an important determinant of oxidative stress susceptibility, with several studies showing an inverse relationship between selenium intake and cancer. Because different chemical forms of selenium have been reported to have varying bioactivity, there is a need for nutrigenomic studies that can comprehensively assess whether there are divergent effects at the molecular level. We examined the gene expression profiles associated with selenomethionine (SM), sodium selenite (SS), and yeast-derived selenium (YS) in the intestine, gastrocnemius, cerebral cortex, and liver of mice. Weanling mice were fed either a selenium-deficient (SD) diet (<0.01 mg/kg diet) or a diet supplemented with one of three selenium sources (1 mg/kg diet, as either SM, SS or YS) for 100 days. All forms of selenium were equally effective in activating standard measures of selenium status, including tissue selenium levels, expression of genes encoding selenoproteins (Gpx1 and Txnrd2), and increasing GPX1 enzyme activity. However, gene expression profiling revealed that SS and YS were similar (and distinct from SM) in both the expression pattern of individual genes and gene functional categories. Furthermore, only YS significantly reduced the expression of Gadd45b in all four tissues and also reduced GADD45B protein levels in liver. Taken together, these results show that gene expression profiling is a powerful technique capable of elucidating differences in the bioactivity of different forms of selenium
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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