454 research outputs found
First-Year Seminar Delivery Method Effect on Student Success at an Appalachian Open-Enrollment Institution
First-year seminars (FYS) have been identified as one of the most effective high impact practices in supporting student success as measured in this study by GPA, semester-to-semester persistence, and second semester student course load. However, those students who would most need this support, students at public open-enrollment institutions in the Appalachian region, have often either not been required to participate or have not been given the chance to do so due to limits on academic program length or a perceived lack of resources at such institutions. This research measured the effectiveness of an FYS program in the above defined environment where the institution studied gave programs the option of a standalone FYS course, or a pre-professional, discipline linked (PPDL) course where FYS content was delivered within preexisting 100-level content specific introductory courses. The course was mandated for all first-time freshmen or transfers with 30 or fewer transferable credit hours. The data demonstrated that the less resource intense PPDL method was just as effective as the standalone course
Neutralino-hadron scattering in the NMSSM
We provide a scan of the parameter space for neutralino-hadron scattering in
the next-to-minimal supersymmetric standard model using an updated value for
the strange quark sigma commutator. These results also take into account
constraints from WMAP data on the relic density and new constraints from the
Large Hadron Collider. We find that the resultant spin-independent cross
sections are smaller in magnitude than those found in recent results obtained
within the constrained minimal supersymmetric standard model, yet still great
enough to feasibly allow for detection in the case of bino-like neutralinos.Comment: 4 pages 5 figure
Atmospheric circulation patterns, cloud-to-ground lightning, and locally intense convective rainfall associated with debris flow initiation in the Dolomite Alps of northeastern Italy
The Dolomite Alps of northeastern Italy experience debris flows with great
frequency during the summer months. An ample supply of unconsolidated
material on steep slopes and a summer season climate regime characterized by
recurrent thunderstorms combine to produce an abundance of these destructive
hydro-geologic events. In the past, debris flow events have been studied
primarily in the context of their geologic and geomorphic characteristics.
The atmospheric contribution to these mass-wasting events has been limited
to recording rainfall and developing intensity thresholds for debris
mobilization. This study aims to expand the examination of atmospheric
processes that preceded both locally intense convective rainfall (LICR) and
debris flows in the Dolomite region. 500âŻhPa pressure level plots of
geopotential heights were constructed for a period of 3Â days prior to
debris flow events to gain insight into the synoptic-scale processes which
provide an environment conducive to LICR in the Dolomites. Cloud-to-ground (CG)
lightning flash data recorded at the meso-scale were incorporated to
assess the convective environment proximal to debris flow source regions.
Twelve events were analyzed and from this analysis three common synoptic-scale circulation patterns were identified. Evaluation of CG flashes at
smaller spatial and temporal scales illustrated that convective processes
vary in their production of CF flashes (total number) and the spatial
distribution of flashes can also be quite different between events over
longer periods. During the 60âŻmin interval immediately preceding debris
flow a majority of cases exhibited spatial and temporal colocation of LICR
and CG flashes. Also a number of CG flash parameters were found to be
significantly correlated to rainfall intensity prior to debris flow initiation
Genomic determination of minimum multi-locus sequence typing schemas to represent the genomic phylogeny of Mycoplasma hominis.
Background: Mycoplasma hominis is an opportunistic human pathogen, associated with clinically diverse disease. Currently, there is no standardised method for typing M. homins, which would aid in understanding pathogen epidemiology and transmission. Due to availability and costs of whole genome sequencing and the challenges in obtaining adequate M. hominis DNA, the use of whole genome sequence analysis to provide clinical guidance is unpractical for this bacterial species as well as other fastidious organisms. Results: This study identified pan-genome set of 700 genes found to be present in four published reference genomes. A subset of 417 genes was identified to be core genome for 18 isolates and 1 reference. Leave-one-out analysis of the core genes highlighted set of 48 genes that are required to recapture the original phylogenetic relationships observed using whole genome SNP analysis. Three 7-locus MLST schemas with high diversity index (97%) and low dN/dS ratios (0.1, 0.13, and 0.11) were derived that could be used to confer good discrimination between strains and could be of practical use in future studies direct on clinical specimens. Conclusions: The genes proposed in this study could be utilised to design a costeffective and rapid PCR-based MLST assay that could be applied directly to clinical isolates, without prior isolation. This study includes additional genomic analysis revealing high levels of genetic heterogeneity among this species. This provides a novel and evidence based approach for the development of MLST schema that accurately represent genomic phylogeny for use in epidemiology and transmission studies
VNTRDB: a bacterial variable number tandem repeat locus database
Variable number tandem repeat-PCR (VNTR-PCR) is a novel method developed for molecular typing of microorganisms. This method has proven useful in epidemiological studies in medical microbiology. Although hundreds of bacterial genomes have been sequenced, variable number tandem repeats (TRs) derived from comparative genome analyses are scarce. This may hamper their application to the surveillance of bacteria in molecular epidemiology. Here, we present a freely accessible variable number tandem repeat database (VNTRDB) that is intended to be a resource for helping in the discovery of putatively polymorphic tandem repeat loci and to aid with assay design by providing the flanking sequences that can be used in subsequent PCR primer design. In order to reveal possible polymorphism, each TR locus was obtained by comparing the sequences between different sets of bacterial genera, species or strains. Through this comparison, TRs which are unique to a genus can also be identified. Moreover, a visualization tool is provided to ensure that the copy number and locus length of repeats are correct. The VNTRDB is available at
Active-matrix GaN micro light-emitting diode display with unprecedented brightness
Displays based on microsized gallium nitride light-emitting diodes possess extraordinary brightness. It is demonstrated here both theoretically and experimentally that the layout of the n-contact in these devices is important for the best device performance. We highlight, in particular, the significance of a nonthermal increase of differential resistance upon multipixel operation. These findings underpin the realization of a blue microdisplay with a luminance of 10ⶠcd/mÂČ
Whole-genome sequencing for national surveillance of Shiga toxinâproducing Escherichia coli O157
Background. National surveillance of gastrointestinal pathogens, such as Shiga toxinâproducing Escherichia coli O157 (STEC O157), is key to rapidly identifying linked cases in the distributed food network to facilitate public health interventions. In this study, we used whole-genome sequencing (WGS) as a tool to inform national surveillance of STEC O157 in terms of identifying linked cases and clusters and guiding epidemiological investigation. Methods. We retrospectively analyzed 334 isolates randomly sampled from 1002 strains of STEC O157 received by the Gastrointestinal Bacteria Reference Unit at Public Health England, Colindale, in 2012. The genetic distance between each isolate, as estimated by WGS, was calculated and phylogenetic methods were used to place strains in an evolutionary context. Results. Estimates of linked clusters representing STEC O157 outbreaks in England and Wales increased by 2-fold when WGS was used instead of traditional typing techniques. The previously unidentified clusters were often widely geographically distributed and small in size. Phylogenetic analysis facilitated identification of temporally distinct cases sharing common exposures and delineating those that shared epidemiological and temporal links. Comparison with multi locus variable number tandem repeat analysis (MLVA) showed that although MLVA is as sensitive as WGS, WGS provides a more timely resolution to outbreak clustering. Conclusions. WGS has come of age as a molecular typing tool to inform national surveillance of STEC O157; it can be used in real time to provide the highest strain-level resolution for outbreak investigation. WGS allows linked cases to be identified with unprecedented specificity and sensitivity that will facilitate targeted and appropriate public health investigations
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