775 research outputs found
Effects of Administering Progesterone and GnRH Before Puberty on Age at Puberty and Reproductive Response in Crossbred Beef Heifers
One hundred six crossbred heifers were utilized to determine prepubertal treatment of progesterone or progesterone plus Gonadotropin Releasing Hormone (GnRH) on age at puberty, conception to a synchronized estrus and conception during the breeding season. Days to puberty were 369.5 ± 6.2, 363.1 ± 9.9 and 360.4 ± 7.8 or control, progesterone primed and progesterone plus Gonadotropin Releasing Hormone (GnRH), respectively. There was no difference (P\u3e.05) in age of puberty, number cycling before synchronization or conception rate during a 35-day breeding season. The percentage of heifers conceiving to synchronized estrus was lower (P\u3c.10) for control compared to progesterone or progesterone plus GnRH treated heifers. Injecting GnRH at breeding had little (P\u3e.05) effect on increasing conception rates to the synchronized estrus or during the breeding season
Economic Analysis of Using Mixing Equipment for Growing Heifers
Seventy-two Simmental cross and Charolais cross heifers (475 lb.) were utilized in a growing study to estimate the economic value of using a mixer wagon and feed scale to feed light cattle a high roughage diet. Cattle fed the mixed diet gained an additional 22.6 lb. on 61.2 lb. less dry matter over the 133-day trial than did cattle fed the unmixed diet. Annual ownership and repair costs were assumed to equal 8O/cwt and if corn, hay and corn silage were worth 80 and $25 per ton, respectively, it would take a minimum of 114 head on feed for 133 days each year to pay annual costs for the wagon. The economic analysis of the data from this trial suggests that even relatively small cattle feeding operations should strongly consider investing in a mixer wagon with a scale
Working Memory, but Not IQ, Predicts Subsequent Learning in Children with Learning Difficulties
The purpose of the present study was to compare the predictive power of working memory and IQ in children identified as having learning difficulties. The term ‘working memory’ refers to the capacity to store and manipulate information in mind for brief periods of time. Working memory capacity is strongly related to learning abilities and academic progress, predicting current and subsequent scholastic attainments of children across the school years in both literacy and numeracy. Children aged between 7 and 11 years were tested at Time 1 on measures of working memory, IQ, and learning. They were then retested two years later on the learning measures. The findings indicated that working memory capacity and domain-specific knowledge at Time 1, but not IQ, were significant predictors of learning at Time 2. The implications for screening and intervention are discussed
The in-plane paraconductivity in La_{2-x}Sr_xCuO_4 thin film superconductors at high reduced-temperatures: Independence of the normal-state pseudogap
The in-plane resistivity has been measured in (LSxCO)
superconducting thin films of underdoped (), optimally-doped
() and overdoped () compositions. These films were grown
on (100)SrTiO substrates, and have about 150 nm thickness. The in-plane
conductivity induced by superconducting fluctuations above the superconducting
transition (the so-called in-plane paraconductivity, ) was
extracted from these data in the reduced-temperature range
10^{-2}\lsim\epsilon\equiv\ln(T/\Tc)\lsim1. Such a
was then analyzed in terms of the
mean-field--like Gaussian-Ginzburg-Landau (GGL) approach extended to the
high- region by means of the introduction of a total-energy cutoff,
which takes into account both the kinetic energy and the quantum localization
energy of each fluctuating mode. Our results strongly suggest that at all
temperatures above Tc, including the high reduced-temperature region, the
doping mainly affects in LSxCO thin films the normal-state properties and that
its influence on the superconducting fluctuations is relatively moderate: Even
in the high- region, the in-plane paraconductivity is found to be
independent of the opening of a pseudogap in the normal state of the underdoped
films.Comment: 35 pages including 10 figures and 1 tabl
Characterisation of a major phytoplankton bloom in the River Thames (UK) using flow cytometry and high performance liquid chromatography
Recent river studies have observed rapid phytoplankton dynamics, driven by diurnal cycling and short-term responses to storm events, highlighting the need to adopt new high-frequency characterisation methods to understand these complex ecological systems. This study utilised two such analytical methods; pigment analysis by high performance liquid chromatography (HPLC) and cell counting by flow cytometry (FCM), alongside traditional chlorophyll spectrophotometry and light microscopy screening, to characterise the major phytoplankton bloom of 2015 in the River Thames, UK. All analytical techniques observed a rapid increase in chlorophyll a concentration and cell abundances from March to early June, caused primarily by a diatom bloom. Light microscopy identified a shift from pennate to centric diatoms during this period. The initial diatom bloom coincided with increased HPLC peridinin concentrations, indicating the presence of dinoflagellates which were likely to be consuming the diatom population. The diatom bloom declined rapidly in early June, coinciding with a storm event. There were low chlorophyll a concentrations (by both HPLC and spectrophotometric methods) throughout July and August, implying low biomass and phytoplankton activity.However, FCM revealed high abundances
of pico-chlorophytes and cyanobacteria through July and August, showing that phytoplankton communities remain active and abundant throughout the summer period. In combination, these techniques are able to simultaneously characterise a wider range of phytoplankton groups, with greater certainty, and provide improved understanding of phytoplankton functioning (e.g. production of UV inhibiting pigments by cyanobacteria in response to high light levels) and ecological status (through examination of pigment degradation products). Combined HPLC and FCM analyses offer rapid and cost-effective characterisation of phytoplankton communities at appropriate timescales. This will allow a more-targeted use of light microscopy to capture phytoplankton peaks or to investigate periods of rapid community succession. This will lead to greater system understanding of phytoplankton succession in response to biogeochemical drivers
Top-squark searches at the Tevatron in models of low-energy supersymmetry breaking
We study the production and decays of top squarks (stops) at the Tevatron
collider in models of low-energy supersymmetry breaking. We consider the case
where the lightest Standard Model (SM) superpartner is a light neutralino that
predominantly decays into a photon and a light gravitino. Considering the
lighter stop to be the next-to-lightest Standard Model superpartner, we analyze
stop signatures associated with jets, photons and missing energy, which lead to
signals naturally larger than the associated SM backgrounds. We consider both
2-body and 3-body decays of the top squarks and show that the reach of the
Tevatron can be significantly larger than that expected within either the
standard supergravity models or models of low-energy supersymmetry breaking in
which the stop is the lightest SM superpartner. For a modest projection of the
final Tevatron luminosity, L = 4 fb-1, stop masses of order 300 GeV are
accessible at the Tevatron collider in both 2-body and 3-body decay modes. We
also consider the production and decay of ten degenerate squarks that are the
supersymmetric partners of the five light quarks. In this case we find that
common squark masses up to 360 GeV are easily accessible at the Tevatron
collider, and that the reach increases further if the gluino is light.Comment: 32 pages, 9 figures; references adde
Chemical composition and fatty acid contents in farmed freshwater prawns
The objective of this work was to evaluate the chemical composition and fatty acid contents of Amazonian and giant river prawns. After four-month farming, with the same diet for both species, palmitic and stearic acids were the main saturated fatty acids. Oleic acid was the main monounsatured fatty acid, and the eicosapentaenoic and docosahexaenoic acids were the most abundant polyunsaturated acids. Amazonian prawn has higher levels of protein and polyunsaturated fatty acids than those of the giant river prawn, which shows its potential for aquaculture
Active Galactic Nuclei at the Crossroads of Astrophysics
Over the last five decades, AGN studies have produced a number of spectacular
examples of synergies and multifaceted approaches in astrophysics. The field of
AGN research now spans the entire spectral range and covers more than twelve
orders of magnitude in the spatial and temporal domains. The next generation of
astrophysical facilities will open up new possibilities for AGN studies,
especially in the areas of high-resolution and high-fidelity imaging and
spectroscopy of nuclear regions in the X-ray, optical, and radio bands. These
studies will address in detail a number of critical issues in AGN research such
as processes in the immediate vicinity of supermassive black holes, physical
conditions of broad-line and narrow-line regions, formation and evolution of
accretion disks and relativistic outflows, and the connection between nuclear
activity and galaxy evolution.Comment: 16 pages, 5 figures; review contribution; "Exploring the Cosmic
Frontier: Astrophysical Instruments for the 21st Century", ESO Astrophysical
Symposia Serie
A type 2 diabetes subtype responsive to ACCORD intensive glycemia treatment
OBJECTIVE Current type 2 diabetes (T2D) management contraindicates intensive glycemia treatment in patients with high cardiovascular disease (CVD) risk and is partially motivated by evidence of harms in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial. Heterogeneity in response to intensive glycemia treatment has been observed, suggesting potential benefit for some individuals. RESEARCH DESIGN AND METHODS ACCORD was a randomized controlled trial that investigated whether intensively treating glycemia in individuals with T2D would reduce CVD outcomes. Using a novel approach to cluster HbA1c trajectories, we identified groups in the intensive glycemia arm with modified CVD risk. Genome-wide analysis and polygenic score (PS) were developed to predict group membership. Mendelian randomization was performed to infer causality. RESULTS We identified four clinical groupings in the intensive glycemia arm, and clinical group 4 (C4) displayed fewer CVD (hazard ratio [HR] 0.34; P 5 2.01 × 10-3) and microvascular outcomes (HR 0.86; P 5 0.015) than those receiving standard treatment. A singlenucleotide polymorphism, rs220721, in MAS1 reached suggestive significance in C4 (P 5 4.343 10-7). PS predicted C4 with high accuracy (area under the receiver operating characteristic curve 0.98), and this predicted C4 displayed reduced CVD risk with intensive versus standard glycemia treatment (HR 0.53; P 5 4.02 × 10-6), but not reduced risk of microvascular outcomes (P < 0.05). Mendelian randomization indicated causality between PS, on-trial HbA1c, and reduction in CVD outcomes (P < 0.05). CONCLUSIONS We found evidence of a T2D clinical group in ACCORD that benefited from intensive glycemia treatment, and membership in this group could be predicted using genetic variants. This study generates new hypotheses with implications for precision medicine in T2D and represents an important development in this landmark clinical trial warranting further investigation
Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays
Average charged multiplicities have been measured separately in , and
light quark () events from decays measured in the SLD experiment.
Impact parameters of charged tracks were used to select enriched samples of
and light quark events, and reconstructed charmed mesons were used to select
quark events. We measured the charged multiplicities:
,
, from
which we derived the differences between the total average charged
multiplicities of or quark events and light quark events: and . We compared
these measurements with those at lower center-of-mass energies and with
perturbative QCD predictions. These combined results are in agreement with the
QCD expectations and disfavor the hypothesis of flavor-independent
fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters
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