631 research outputs found
JPL Ephemeris Tapes E9510, E9511, and E9512
The first issue of JPL Ephemeris Tapes is described. These tapes carry the positions and velocities of the planets and of the Moon, plus nutations and nutation rates in longitude and obliquity, together with second and fourth modified differences, for the interval December 30, 1949, to January 5, 2000
University Identity Change Through a Psychological Sense of Community Framework: A Case Study of the ELIMAR Model
Leading through identity change is a highly emotive experience. When leadership is understood as an emotional community development process, the benefits for repurposing identity are greatly enhanced. This article introduces a change model that embeds emotional awareness throughout a four-phased process, adapting concepts originally presented in McMillan and Chavis’s (1986) psychological sense of community (PSOC) theory and Scott and Jaffee’s (1989) change curve model. In this case study, we focus on a four-year multi-campus northeastern United States public university as a model to investigate how individuals in leadership positions consider the role of affect in creating positive identity change to the university’s psychological sense of community
Sexual differentiation of the zebra finch song system: potential roles for sex chromosome genes
Abstract
Background
Recent evidence suggests that some sex differences in brain and behavior might result from direct genetic effects, and not solely the result of the organizational effects of steroid hormones. The present study examined the potential role for sex-biased gene expression during development of sexually dimorphic singing behavior and associated song nuclei in juvenile zebra finches.
Results
A microarray screen revealed more than 2400 putative genes (with a false discovery rate less than 0.05) exhibiting sex differences in the telencephalon of developing zebra finches. Increased expression in males was confirmed in 12 of 20 by qPCR using cDNA from the whole telencephalon; all of these appeared to be located on the Z sex chromosome. Six of the genes also showed increased expression in one or more of the song control nuclei of males at post-hatching day 25. Although the function of half of the genes is presently unknown, we have identified three as: 17-beta-hydroxysteroid dehydrogenase type IV, methylcrotonyl-CoA carboxylase, and sorting nexin 2.
Conclusion
The data suggest potential influences of these genes in song learning and/or masculinization of song system morphology, both of which are occurring at this developmental stage
Multifaceted contributions : health workers and smallpox eradication in India
Smallpox eradication in South Asia was a result of the efforts of many grades of health-workers. Working from within the confines of international organisations and government structures, the role of the field officials, who were of various nationalities and also drawn from the cities and rural enclaves of the countries in these regions, was crucial to the development and deployment of policies. However, the role of these personnel is often downplayed in official histories and academic histories, which highlight instead the roles played by a handful of senior officials within the World Health Organization and the federal governments in the sub-continent. This article attempts to provide a more rounded assessment of the complex situation in the field. In this regard, an effort is made to underline the great usefulness of the operational flexibility displayed by field officers, wherein lessons learnt in the field were made an integral part of deploying local campaigns; careful engagement with the communities being targeted, as well as the employment of short term workers from amongst them, was an important feature of this work
A proof-of-concept study for the design of a VLP-based combinatorial HPV and placental malaria vaccine
Abstract In Africa, cervical cancer and placental malaria (PM) are a major public health concern. There is currently no available PM vaccine and the marketed Human Papillomavirus (HPV) vaccines are prohibitively expensive. The idea of a combinatorial HPV and PM vaccine is attractive because the target population for vaccination against both diseases, adolescent girls, would be overlapping in Sub-Saharan Africa. Here we demonstrate proof-of-concept for a combinatorial vaccine utilizing the AP205 capsid-based virus-like particle (VLP) designed to simultaneously display two clinically relevant antigens (the HPV RG1 epitope and the VAR2CSA PM antigen). Three distinct combinatorial VLPs were produced displaying one, two or five concatenated RG1 epitopes without obstructing the VLP’s capacity to form. Co-display of VAR2CSA was achieved through a split-protein Tag/Catcher interaction without hampering the vaccine stability. Vaccination with the combinatorial vaccine(s) was able to reduce HPV infection in vivo and induce anti-VAR2CSA IgG antibodies, which inhibited binding between native VAR2CSA expressed on infected red blood cells and chondroitin sulfate A in an in vitro binding-inhibition assay. These results show that the Tag/Catcher AP205 VLP system can be exploited to make a combinatorial vaccine capable of eliciting antibodies with dual specificity
The Design, Construction, and Some Uses of an Automatic Recording Balance
Many chemical and physical reactions are accompanied by changes in weight of the reactants due to evaporation of liquids, evolution of gases, or adsorption of gases. Studies are made using data which show the manner in which the weight changes with time. Kinetic studies are made from a knowledge of the rate of loss or gain of a component. The drying of a precipitate to constant weight involves a loss in weight. Rates of evaporation of liquids from different types of surfaces involve changes of weight as a function of time. Several instruments and methods are used to follow weight changes. Gas buret systems are used to measure the volume of a gaseous component which is adding to or subtracting from the weight of a reactant. The ordinary analytical balance is used to follow weight changes by making intermittent weighings. This latter method involves tedious operations and interruptions of the treatment of the reactants. Effort has been put forth to devise instruments which will automatically weigh substances and record these weighings on some type of graph. Gregg and Wintle (1) devised a glass automatic electrical sorption balance. Gregg (2) later described a recording system for this type balance. Eyrand (3) reported a glass sorption balance of a somewhat different type. Duval (4) described a thermal balance that automatically records changes in weight on film. Described in this paper is an instrument attached to a modified ordinary analytical balance which automatically records on graph paper changes in weight as a function of time
Increases in sampling support the southern Gondwanan hypothesis for the origin of dinosaurs
Dinosaurs were ubiquitous in terrestrial ecosystems through most of the Mesozoic and are still diversely represented in the modern fauna in the form of birds. Recent efforts to better understand the origins of the group have resulted in the discovery of many new species of early dinosaurs and their closest relatives (dinosauromorphs). In addition, recent re-examinations of early dinosaur phylogeny have highlighted uncertainties regarding the interrelationships of the main dinosaur lineages (Sauropodomorpha, Theropoda and Ornithischia), and questioned the traditional hypothesis that the group originated in South Gondwana and gradually dispersed over Pangaea. Here, we use a historical approach to examine the impact of new fossil discoveries and changing phylogenetic hypotheses on biogeographic scenarios for dinosaur origins over 20 years of research time, and analyse the results in the light of different fossil record sampling regimes. Our results consistently optimize South Gondwana as the ancestral area for Dinosauria, as well as for more inclusive clades including Dinosauromorpha, and show that this hypothesis is robust to increased taxonomic and geographic sampling and divergent phylogenetic results. Our results do not find any support for the recently proposed Laurasian origin of dinosaurs and suggest that a southern Gondwanan origin is by far the most plausible given our current knowledge of the diversity of early dinosaurs and non-dinosaurian dinosauromorphs
Performance-based financing as a health system reform : mapping the key dimensions for monitoring and evaluation
Peer reviewedPublisher PD
Use of the Behavior Assessment Tool in 18 Pilot Residency Programs
Background: The purpose of this study was to determine the feasibility and evaluate the effectiveness of the American Board of Orthopaedic Surgery Behavior Tool (ABOSBT) for measuring professionalism.
Methods: Through collaboration between the American Board of Orthopaedic Surgery and American Orthopaedic Association\u27s Council of Residency Directors, 18 residency programs piloted the use of the ABOSBT. Residents requested assessments from faculty at the end of their clinical rotations, and a 360° request was performed near the end of the academic year. Program Directors (PDs) rated individual resident professionalism (based on historical observation) at the outset of the study, for comparison to the ABOSBT results.
Results: Nine thousand eight hundred ninety-two evaluations were completed using the ABOSBT for 449 different residents by 1,012 evaluators. 97.6% of all evaluations were scored level 4 or 5 (high levels of professional behavior) across all of the 5 domains. In total, 2.4% of all evaluations scored level 3 or below reflecting poorer performance. Of 431 residents, the ABOSBT identified 26 of 32 residents who were low performers (2 or more \u3c level 3 scores in a domain) and who also scored below expectations by the PD at the start of the pilot project (81% sensitivity and 57% specificity), including 13 of these residents scoring poorly in all 5 domains. Evaluators found the ABOSBT was easy to use (96%) and that it was an effective tool to assess resident professional behavior (81%).
Conclusions: The ABOSBT was able to identify 2.4% low score evaluations (
Level of Evidence: Level II
Stringency of start codon selection modulates autoregulation of translation initiation factor eIF5
An AUG in an optimal nucleotide context is the preferred translation initiation site in eukaryotic cells. Interactions among translation initiation factors, including eIF1 and eIF5, govern start codon selection. Experiments described here showed that high intracellular eIF5 levels reduced the stringency of start codon selection in human cells. In contrast, high intracellular eIF1 levels increased stringency. High levels of eIF5 induced translation of inhibitory upstream open reading frames (uORFs) in eIF5 mRNA that initiate with AUG codons in conserved poor contexts. This resulted in reduced translation from the downstream eIF5 start codon, indicating that eIF5 autoregulates its own synthesis. As with eIF1, which is also autoregulated through translation initiation, features contributing to eIF5 autoregulation show deep evolutionary conservation. The results obtained provide the basis for a model in which auto- and cross-regulation of eIF5 and eIF1 translation establish a regulatory feedback loop that would stabilize the stringency of start codon selection
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