89 research outputs found
Kentucky Pride Hay Growers Association — After One Year
High quality forages have been the frontline for successful horse and cattle operations for years. In Kentucky, we have grown, harvested and stored hay on the farm for as long as we have farmed. It is one of our principal forms of overwinter feed and has been grown primarily as an on-the-farm feed source
A Prediction for the 4-Loop \beta Function
We predict that the four-loop contribution \beta_3 to the QCD \beta function
in the MS-bar prescription is given by
\beta_3\simeq 23,600(900) - 6,400(200) N_f + 350(70) N_f^2 + 1.5 N_f^3, where
N_f is the number of flavours and the coefficient of N_f^3 is an exact result
from large-N_f expansion. In the phenomenologically-interesting case N_f=3, we
estimate \beta_3 = (7.6 \pm 0.1) x 10^3. We discuss our estimates of the errors
in these QCD predictions, basing them on the demonstrated accuracy of our
method in test applications to the O(N) \Phi^4 theory, and on variations in the
details of our estimation method, which goes beyond conventional Pade
approximants by estimating and correcting for subasymptotic deviations from
exact results.Comment: 11 pages, LaTeX, including 2 figures in 3 ps files; requires
epsfig.sty; added comparison with recent exact result
Spontaneous Lorentz Violation and the Long-Range Gravitational Preferred-Frame Effect
Lorentz-violating operators involving Standard Model fields are tightly
constrained by experimental data. However, bounds are more model-independent
for Lorentz violation appearing in purely gravitational couplings. The
spontaneous breaking of Lorentz invariance by the vacuum expectation value of a
vector field selects a universal rest frame. This affects the propagation of
the graviton, leading to a modification of Newton's law of gravity. We compute
the size of the long-range preferred-frame effect in terms of the coefficients
of the two-derivative operators in the low-energy effective theory that
involves only the graviton and the Goldstone bosons.Comment: 11 pages, no figures, revtex4. v4: Replaced to match version to
appear in Phys. Lett. B (minor corrections of form
Mediator recruits the cohesin loader Scc2 to RNA Pol II-transcribed genes and promotes sister chromatid cohesion.
[EN]The ring-like cohesin complex plays an essential role in chromosome segregation, organization, and double-strand break repair through its ability to bring two DNA double helices together. Scc2 (NIPBL in humans) together with Scc4 functions as the loader of cohesin onto chromosomes. Chromatin adapters such as the RSC complex facilitate the localization of the Scc2-Scc4 cohesin loader. Here, we identify a broad range of Scc2-chromatin protein interactions that are evolutionarily conserved and reveal a role for one complex, Mediator, in the recruitment of the cohesin loader. We identified budding yeast Med14, a subunit of the Mediator complex, as a high copy suppressor of poor growth in Scc2 mutant strains. Physical and genetic interactions between Scc2 and Mediator are functionally substantiated in direct recruitment and cohesion assays. Depletion of Med14 results in defective sister chromatid cohesion and the decreased binding of Scc2 at RNA Pol II-transcribed genes. Previous work has suggested that Mediator, Nipbl, and cohesin connect enhancers and promoters of active mammalian genes. Our studies suggest an evolutionarily conserved fundamental role for Mediator in the direct recruitment of Scc2 to RNA Pol II-transcribed genes
Preparation, imaging, and quantification of bacterial surface motility assays.
Publication fees for this article were partially sponsored by Bruker Corporation.International audienceBacterial surface motility, such as swarming, is commonly examined in the laboratory using plate assays that necessitate specific concentrations of agar and sometimes inclusion of specific nutrients in the growth medium. The preparation of such explicit media and surface growth conditions serves to provide the favorable conditions that allow not just bacterial growth but coordinated motility of bacteria over these surfaces within thin liquid films. Reproducibility of swarm plate and other surface motility plate assays can be a major challenge. Especially for more "temperate swarmers" that exhibit motility only within agar ranges of 0.4%-0.8% (wt/vol), minor changes in protocol or laboratory environment can greatly influence swarm assay results. "Wettability", or water content at the liquid-solid-air interface of these plate assays, is often a key variable to be controlled. An additional challenge in assessing swarming is how to quantify observed differences between any two (or more) experiments. Here we detail a versatile two-phase protocol to prepare and image swarm assays. We include guidelines to circumvent the challenges commonly associated with swarm assay media preparation and quantification of data from these assays. We specifically demonstrate our method using bacteria that express fluorescent or bioluminescent genetic reporters like green fluorescent protein (GFP), luciferase (lux operon), or cellular stains to enable time-lapse optical imaging. We further demonstrate the ability of our method to track competing swarming species in the same experiment
Gas emissions, minerals, and tars associated with three coal fires, Powder River Basin, USA.
Ground-based surveys of three coal fires and airborne surveys of two of the fires were conducted near Sheridan, Wyoming. The fires occur in natural outcrops and in abandoned mines, all containing Paleocene-age subbituminous coals. Diffuse (carbon dioxide (CO(2)) only) and vent (CO(2), carbon monoxide (CO), methane, hydrogen sulfide (H(2)S), and elemental mercury) emission estimates were made for each of the fires. Additionally, gas samples were collected for volatile organic compound (VOC) analysis and showed a large range in variation between vents. The fires produce locally dangerous levels of CO, CO(2), H(2)S, and benzene, among other gases. At one fire in an abandoned coal mine, trends in gas and tar composition followed a change in topography. Total CO(2) fluxes for the fires from airborne, ground-based, and rate of fire advancement estimates ranged from 0.9 to 780mg/s/m(2) and are comparable to other coal fires worldwide. Samples of tar and coal-fire minerals collected from the mouth of vents provided insight into the behavior and formation of the coal fires
Space-based research in fundamental physics and quantum technologies
Space-based experiments today can uniquely address important questions
related to the fundamental laws of Nature. In particular, high-accuracy physics
experiments in space can test relativistic gravity and probe the physics beyond
the Standard Model; they can perform direct detection of gravitational waves
and are naturally suited for precision investigations in cosmology and
astroparticle physics. In addition, atomic physics has recently shown
substantial progress in the development of optical clocks and atom
interferometers. If placed in space, these instruments could turn into powerful
high-resolution quantum sensors greatly benefiting fundamental physics.
We discuss the current status of space-based research in fundamental physics,
its discovery potential, and its importance for modern science. We offer a set
of recommendations to be considered by the upcoming National Academy of
Sciences' Decadal Survey in Astronomy and Astrophysics. In our opinion, the
Decadal Survey should include space-based research in fundamental physics as
one of its focus areas. We recommend establishing an Astronomy and Astrophysics
Advisory Committee's interagency ``Fundamental Physics Task Force'' to assess
the status of both ground- and space-based efforts in the field, to identify
the most important objectives, and to suggest the best ways to organize the
work of several federal agencies involved. We also recommend establishing a new
NASA-led interagency program in fundamental physics that will consolidate new
technologies, prepare key instruments for future space missions, and build a
strong scientific and engineering community. Our goal is to expand NASA's
science objectives in space by including ``laboratory research in fundamental
physics'' as an element in agency's ongoing space research efforts.Comment: a white paper, revtex, 27 pages, updated bibliograph
Epidemiology and Outcomes of Hospitalized Adults with SARS-CoV-2 Community-Acquired Pneumonia in Louisville, Kentucky
Background: During the ongoing pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), SARS-CoV-2 community-acquired pneumonia (CAP) has been the primary cause of hospitalization. The objective of this study was to evaluate the clinical characteristics and outcomes of 1,013 patients hospitalized with SARS-CoV-2 CAP from September 2020 through March 2021 in Louisville, Kentucky.
Methods: This was a retrospective observational study of 1,013 patients hospitalized with SARS-CoV-2 CAP at eight of the adult hospitals in the city of Louisville from September 2020 through March 2021. Patients with 1) a positive reverse transcriptase-polymerase chain reaction (RT-PCR) for SARS-CoV-2, 2) fever, cough, or shortness of breath, and 3) an infiltrate on chest imaging were defined as having SARS-CoV-2 CAP. Data were abstracted from each hospital’s electronic health record. Descriptive statistics were performed on clinical and epidemiological characteristics of hospitalized patients with SARS-CoV-2 CAP. Demographic characteristics of the study population were compared with census data from the city of Louisville. Data were analyzed by descriptive and inferential statistics using R version 3.4.0.
Results: Of the 1,013 patients hospitalized with SARS-CoV-2 CAP, the median age was 65 years, 53% were males, 24% reported their race as African American or Black, and 6% identified as Hispanic. The most frequent comorbidities were hypertension (73%), obesity (56%), and diabetes (43%). At the time of admission, 60% required supplemental oxygen. The mortality rate was 19% for the total population and 45% for the 359 patients admitted to the intensive care unit (ICU). For each comorbidity, the proportion of hospitalized patients with SARS-CoV-2 CAP was significantly different from the Louisville population (P
Conclusions: The elderly, males, and patients with a history of coronary artery disease, cerebrovascular disease, chronic obstructive pulmonary disease, hypertension, diabetes, renal disease, or obesity are overrepresented among hospitalized patients with SARS-CoV-2 CAP compared to the Louisville population. These patients are also more likely to require ICU care and experience worse clinical outcomes, with death occurring in approximately one in every five hospitalizations
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