590 research outputs found
Calibration of Pasture Forage Mass to Plate Meter Compressed Height is a Second-order Response with a Zero Intercept
Discusses how plant canopy structure effects the calibration between plate meter compressed height (CHt) and pasture forage mas
Impact of Powder Variability on the Microstructure and Mechanical Behavior of Selective Laser Melted (SLM) Alloy 718
Nickel Alloy 718 has found wide use in high-temperature aerospace applications (up to 700C), due to a combination of good mechanical properties, environmental resistance, and workability at moderate cost. These properties have led Alloy 718 to early adoption by selective laser melting (SLM) additive manufacturing. This presentation will share results from a comprehensive industry survey of 718 powder feedstock for SLM. The survey focuses on the impact of variability in powder characteristics on build quality, microstructure, tensile and high cycle fatigue in the as-fabricated and machined surface conditions. The investigation includes sixteen powder lots from eight suppliers that are produced by gas atomization or rotary atomization in argon or nitrogen. This research was previously presented and published at the 9th International Symposium on Superalloy 718 & Derivatives and was funded by NASA Space Launch System Liquid Engine Office with the Human Exploration Operations Mission Directorate
Ovine reference materials and assays for prion genetic testing
<p>Abstract</p> <p>Background</p> <p>Genetic predisposition to scrapie in sheep is associated with several variations in the peptide sequence of the prion protein gene (<it>PRNP</it>). DNA-based tests for scoring <it>PRNP </it>codons are essential tools for eradicating scrapie and for evaluating rare alleles for increased resistance to disease. In addition to those associated with scrapie, there are dozens more <it>PRNP </it>polymorphisms that may occur in various flocks. If not accounted for, these sites may cause base-pair mismatching with oligonucleotides used in DNA testing. Thus, the fidelity of scrapie genetic testing is enhanced by knowing the position and frequency of <it>PRNP </it>polymorphisms in targeted flocks.</p> <p>Results</p> <p>An adaptive DNA sequencing strategy was developed to determine the 771 bp <it>PRNP </it>coding sequence for any sheep and thereby produce a consensus sequence for targeted flocks. The strategy initially accounted for 43 known polymorphisms and facilitates the detection of unknown polymorphisms through an overlapping amplicon design. The strategy was applied to 953 sheep DNAs from multiple breeds in U.S. populations. The samples included two sets of reference sheep: one set for standardizing <it>PRNP </it>genetic testing and another set for discovering polymorphisms, estimating allele frequencies, and determining haplotype phase. DNA sequencing revealed 16 previously unreported polymorphisms, including a L237P variant on the F<sub>141 </sub>haplotype. Two mass spectrometry multiplex assays were developed to score five codons of interest in U.S. sheep: 112, 136, 141, 154, and 171. Reference tissues, DNA, trace files, and genotypes from this project are publicly available for use without restriction.</p> <p>Conclusion</p> <p>Identifying ovine <it>PRNP </it>polymorphisms in targeted flocks is critical for designing efficient scrapie genetic testing systems. Together with reference DNA panels, this information facilitates training, certification, and development of new tests and knowledge that may expedite the eradication of sheep scrapie.</p
Controlled formation of metastable germanium polymorphs
The nucleation of metastable germanium polymorphs on decompression is studied using in situ synchrotron x-ray diffraction. We show that the transition pathway is critically dependent on the hydrostaticity. Quasihydrostatic conditions result in the nucleation of the rhombohedral r8 phase, followed by the cubic bc8 and hexagonal diamond phases. In contrast, the presence of shear yields the tetragonal st12 phase. Thus, targeted nucleation of a metastable polymorph is now possible. This observation has implications for the technological exploitation of Ge, but also for other tetrahedral systems
2-Mercaptomethyl-thiazolidines use conserved aromatic-S interactions to achieve broad-range inhibition of metallo-ÎČ-lactamases
Infections caused by multidrug resistant (MDR) bacteria are a major public health threat. Carbapenems are among the most potent antimicrobial agents that are commercially available to treat MDR bacteria. Bacterial production of carbapenem-hydrolysing metallo-b-lactamases (MBLs) challenges their safety and efficacy, with subclass B1 MBLs hydrolysing almost all b-lactam antibiotics. MBL inhibitors would fulfil an urgent clinical need by prolonging the lifetime of these life-saving drugs. Here we report the synthesis and activity of a series of 2-mercaptomethyl-thiazolidines (MMTZs), designed to replicate MBL interactions with reaction intermediates or hydrolysis products. MMTZs are potent competitive inhibitors of B1 MBLs in vitro (e.g., Ki ÂŒ 0.44 mM vs. NDM-1). Crystal structures of MMTZ complexes reveal similar binding patterns to the most clinically important B1 MBLs (NDM-1, VIM-2 and IMP-1), contrasting with previously studied thiol-based MBL inhibitors, such as bisthiazolidines (BTZs) or captopril stereoisomers, which exhibit lower, more variable potencies and multiple binding modes. MMTZ binding involves thiol coordination to the Zn(II) site and extensive hydrophobic interactions, burying the inhibitor more deeply within the active site than D/L-captopril. Unexpectedly, MMTZ binding features a thioetherâp interaction with a conserved active-site aromatic residue, consistent with their equipotent inhibition and similar binding to multiple MBLs. MMTZs penetrate multiple Enterobacterales, inhibit NDM-1 in situ, and restore carbapenem potency against clinical isolates expressing B1 MBLs. Based on their inhibitory profile and lack of eukaryotic cell toxicity, MMTZs represent a promising scaffold for MBL inhibitor development. These results also suggest sulphurâp interactions can be exploited for general ligand design in medicinal chemistry
The Vehicle, Spring 1990
Table of Contents
Poetry & Photos
SpellsAmy Sparkspage 5
Rooting inAmy Sparkspage 6
Perfect NightDerrick Hoguepage 7
Virginia DareShane Taylorpage 8-9
Farmer\u27s Wife and DogShane Taylorpage 10
PovertyNancy Holschuhpage 11
A Strong ManBrad Johnsonpage 12-13
PhotoAiman Humaidehpage 13
Stupid Camp Song, Cartoon LifeEdward Schellpage 14
Into midnight, aloneDenise Santorpage 15
Love of the mindDenise Santorpage 16
Sweet LoveKaren Savagepage 17
Fantastic YellowKaren Savagepage 18
Tea-time in WisconsinTom Caldwellpage 19
PhotoTania Sanchezpage 20, 21
Any ThursdayTom Caldwellpage 22
WesteringTom Caldwellpage 23
Watch PocketAnthony Smithpage 24
Voluntary ResolveMatt Mansfieldpage 25-26
Essays
A Return from FaithPeter J. Scalespage 27-28
Fiction
Eye SieveTara L. Affolterpage 29-31
Persephone and the Worm Rancherpage 32-37
Authors
Biographiespage 38-39https://thekeep.eiu.edu/vehicle/1055/thumbnail.jp
Perspectives on Astrophysics Based on Atomic, Molecular, and Optical (AMO) Techniques
About two generations ago, a large part of AMO science was dominated by
experimental high energy collision studies and perturbative theoretical
methods. Since then, AMO science has undergone a transition and is now
dominated by quantum, ultracold, and ultrafast studies. But in the process, the
field has passed over the complexity that lies between these two extremes. Most
of the Universe resides in this intermediate region. We put forward that the
next frontier for AMO science is to explore the AMO complexity that describes
most of the Cosmos.Comment: White paper submission to the Decadal Assessment and Outlook Report
on Atomic, Molecular, and Optical (AMO) Science (AMO 2020
Adoption and use of social media among public health departments
<p>Abstract</p> <p>Background</p> <p>Effective communication is a critical function within any public health system. Social media has enhanced communication between individuals and organizations and has the potential to augment public health communication. However, there is a lack of reported data on social media adoption within public health settings. The purposes of this study were to assess: 1) the extent to which state public health departments (SHDs) are using social media; 2) which social media applications are used most often; and 3) how often social media is used interactively to engage audiences.</p> <p>Methods</p> <p>This was a non-experimental, cross sectional study of SHD social media sites. Screen capture software Snag-It<sup>Âź </sup>was used to obtain screenshots of SHD social media sites across five applications. These sites were coded for social media presence, interactivity, reach, and topic.</p> <p>Results</p> <p>Sixty percent of SHDs reported using at least one social media application. Of these, 86.7% had a Twitter account, 56% a Facebook account, and 43% a YouTube channel. There was a statistically significant difference between average population density and use of social media (p = .01). On average, SHDs made one post per day on social media sites, and this was primarily to distribute information; there was very little interaction with audiences. SHDs have few followers or friends on their social media sites. The most common topics for posts and tweets related to staying healthy and diseases and conditions. Limitations include the absence of a standard by which social media metrics measure presence, reach, or interactivity; SHDs were only included if they had an institutionally maintained account; and the study was cross sectional.</p> <p>Conclusions</p> <p>Social media use by public health agencies is in the early adoption stage. However, the reach of social media is limited. SHDs are using social media as a channel to distribute information rather than capitalizing on the interactivity available to create conversations and engage with the audience. If public health agencies are to effectively use social media then they must develop a strategic communication plan that incorporates best practices for expanding reach and fostering interactivity and engagement.</p
An HI survey of six Local Group analogs: I. Survey description and the search for high-velocity clouds
We have conducted an HI 21 cm emission-line survey using the Parkes 20cm
multibeam instrument and the Australia Telescope Compact Array (ATCA) of six
loose groups of galaxies chosen to be analogs to the Local Group. The goal of
this survey is to make a census of the HI-rich galaxies and high-velocity
clouds (HVCs) within these groups and compare these populations with those in
the Local Group. The Parkes observations covered the entire volume of each
group with a rms M(HI) sensitivity of 4-10x10^5 M(sun) per 3.3 km/s channel.
All potential sources detected in the Parkes data were confirmed with ATCA
observations at ~2' resolution and the same M(sun) sensitivity. All the
confirmed sources have associated stellar counterparts; no starless HI
clouds--HVC analogs--were found in the six groups. In this paper, we present a
description of the survey parameters, its sensitivity and completeness. Using
the population of compact HVCs (CHVCs) around the Milky Way as a template
coupled with the detailed knowledge of our survey parameters, we infer that our
non-detection of CHVC analogs implies that, if similar populations exist in the
six groups studied, the CHVCs must be clustered within 90 kpc of group
galaxies, with average M(HI) < 4x10^5 M(sun) at the 95% confidence level. The
corollary is that the same must apply to Milky Way CHVCs. This is consistent
with our previous results from a smaller sample of groups, and in accordance
with recent observational and theoretical constraints from other authors. These
results confirm that there is very little neutral matter around galaxies, and
that any substantial reservoir of baryons must be in other phases.Comment: 10 pages, ApJ accepte
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