3,054 research outputs found
Development, Survival and Phenology of the Sweetclover Weevil Parasitoid, \u3ci\u3ePygostolus Falcatus\u3c/i\u3e (Hymenoptera: Braconidae)
Biennial sweetclovers were widely used for soil improvement and as for- ages in the first half of the 1900s. The introduction of the sweetclover weevil, Sitona cylindricollis, caused a drastic decline in sweetclover acreage. In North Dakota, yellow sweetclover, Melilotus officinalis, is still the legume of choice on organic farms. In an effort to control the weevil, the thelyotokous parasitoid Pygostolus falcatus was imported. Parasitoids were studied for temperature-dependent development, and adult longevity as influenced by temperature and availability of provisions. Development from egg to adult at 15, 20, 25 and 30°C was 58, 28, 22 and 21 d, respectively. No parasitoids were reared out at 10°C, although diapausing first instars were present. Longevity of adult parasitoids provided honey, water, sweetclover and sweet- clover weevils at 15, 20, 25 and 30°C was 29, 22, 12 and 6 d, respectively. Adults provided the following combinations of provisions at 25°C survived for: nothing-2 d; water-2 d; honey-4 d; honey and water - 6 d; honey, water and sweetclover - 11 d; honey, water, sweetclover and hosts - 12 d. Field cage releases and a degree-day model developed for the parasitoid demonstrated that poor synchrony between P. falcatus and the sweetclover weevil hinders its usefulness as a biological control agent
A Long-Term Analysis of Changes in Farm Size and Financial Performance
This paper examined the changing structure of farms in Kansas. Specifically, changes in farm size, farm type, financial performance, and economies of size were examined using five-year moving averages from 1973 to 2007. Convergence analysis was used to determine whether small farms are catching up to larger farms or whether the difference in performance between these two groups of farms was widening. Results suggested that the gaps between the small farms and large farms have widened.Economies of Size, Financial Performance, Farm Management, Production Economics, D21,
Marginal Propensity to Consume for a Sample of Kansas Farms
This paper examined the marginal propensity to consume (MPC) for a sample of Kansas farms. Sensitivity of estimated MPCs to the use of accrual net farm income, net cash farm income, and the inclusion of off-farm income was also examined. Results yielded a range of short-run MPCs from 0.011 to 0.015. Statistical tests suggested that the income coefficients used to compute short-run MPCs were not statistically different.Farm Consumption, Habit Persistence, Agricultural Finance, Farm Management, E21,
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Hazards to golden-mantled ground squirrels and associated secondary hazard potential from strychnine baiting for forest pocket gophers
Radio telemetry and capture-recapture techniques were used to evaluate the hazards to golden-mantled ground squirrels (Spermophilus lateralis) from hand baiting with 0.5% strychnine-treated oats for western pocket gophers (Thomomys mazama) on conifer plantations in eastern Oregon. Toxicology data were collected on field-killed and caged ground squirrels and on caged mink (Mustela vison), great horned owls (Bubo virginianus), and red-tailed hawks (Buteo jamaicensis). Ground squirrel populations were reduced 50 to 75% following underground baiting for pocket gophers. Maximum amount of strychnine alkaloid found in cheek pouches and carcass of a field-killed golden-mantled ground squirrel was 2.88 mg. Mean amount of strychnine in carcasses was 0.35 mg; almost all occurred in the gut. The estimated LD50 for mink was 0.6 mg/kg. The lowest lethal dose for great horned owls and red-tailed hawks was 7.7 mg/kg and 10.2 mg/kg, respectively. The LD50 for owls and hawks was not determined. Long-term effects on golden-mantled ground squirrel populations and secondary hazard potential to owls and hawks were judged to be minimal. Wild mustelids as large as mink could be adversely affected by consuming the gut content of strychnine-killed golden-mantled ground squirrels
Development, Survival and Phenology of the Sweetclover Weevil Parasitoid, \u3ci\u3ePygostolus Falcatus\u3c/i\u3e (Hymenoptera: Braconidae)
Biennial sweetclovers were widely used for soil improvement and as for- ages in the first half of the 1900s. The introduction of the sweetclover weevil, Sitona cylindricollis, caused a drastic decline in sweetclover acreage. In North Dakota, yellow sweetclover, Melilotus officinalis, is still the legume of choice on organic farms. In an effort to control the weevil, the thelyotokous parasitoid Pygostolus falcatus was imported. Parasitoids were studied for temperature-dependent development, and adult longevity as influenced by temperature and availability of provisions. Development from egg to adult at 15, 20, 25 and 30°C was 58, 28, 22 and 21 d, respectively. No parasitoids were reared out at 10°C, although diapausing first instars were present. Longevity of adult parasitoids provided honey, water, sweetclover and sweet- clover weevils at 15, 20, 25 and 30°C was 29, 22, 12 and 6 d, respectively. Adults provided the following combinations of provisions at 25°C survived for: nothing-2 d; water-2 d; honey-4 d; honey and water - 6 d; honey, water and sweetclover - 11 d; honey, water, sweetclover and hosts - 12 d. Field cage releases and a degree-day model developed for the parasitoid demonstrated that poor synchrony between P. falcatus and the sweetclover weevil hinders its usefulness as a biological control agent
Nested Gausslet Basis Sets
We introduce nested gausslet (NG) bases, an improvement on previous gausslet
bases which can treat systems containing atoms with much larger atomic number.
We also introduce pure Gaussian distorted gausslet bases, which allow the
Hamiltonian integrals to be performed analytically, as well as hybrid bases in
which the gausslets are combined with standard Gaussian-type bases. All these
bases feature the diagonal approximation for the electron-electron
interactions, so that the Hamiltonian is completely defined by two matrices, where is small enough to permit fast
calculations at the Hartree-Fock level. In constructing these bases we have
gained new mathematical insight into the construction of one-dimensional
diagonal bases. In particular we have proved an important theorem relating four
key basis set properties: completeness, orthogonality, zero-moment conditions,
and diagonalization of the coordinate operator matrix. We test our basis sets
on small systems with a focus on high accuracy, obtaining, for example, an
accuracy of Ha for the total Hartree-Fock energy of the neon
atom in the complete basis set limit.Comment: 14 pages, 12 figure
Potential flow theory and operation guide for the panel code PMARC
The theoretical basis for PMARC, a low-order potential-flow panel code for modeling complex three-dimensional geometries, is outlined. Several of the advanced features currently included in the code, such as internal flow modeling, a simple jet model, and a time-stepping wake model, are discussed in some detail. The code is written using adjustable size arrays so that it can be easily redimensioned for the size problem being solved and the computer hardware being used. An overview of the program input is presented, with a detailed description of the input available in the appendices. Finally, PMARC results for a generic wing/body configuration are compared with experimental data to demonstrate the accuracy of the code. The input file for this test case is given in the appendices
Transcriptional networks specifying homeostatic and inflammatory programs of gene expression in human aortic endothelial cells.
Endothelial cells (ECs) are critical determinants of vascular homeostasis and inflammation, but transcriptional mechanisms specifying their identities and functional states remain poorly understood. Here, we report a genome-wide assessment of regulatory landscapes of primary human aortic endothelial cells (HAECs) under basal and activated conditions, enabling inference of transcription factor networks that direct homeostatic and pro-inflammatory programs. We demonstrate that 43% of detected enhancers are EC-specific and contain SNPs associated to cardiovascular disease and hypertension. We provide evidence that AP1, ETS, and GATA transcription factors play key roles in HAEC transcription by co-binding enhancers associated with EC-specific genes. We further demonstrate that exposure of HAECs to oxidized phospholipids or pro-inflammatory cytokines results in signal-specific alterations in enhancer landscapes and associate with coordinated binding of CEBPD, IRF1, and NFκB. Collectively, these findings identify cis-regulatory elements and corresponding trans-acting factors that contribute to EC identity and their specific responses to pro-inflammatory stimuli
A Multiple Classifier System Identifies Novel Cannabinoid CB2 Receptor Ligands
open access articleDrugs have become an essential part of our lives due to their ability to improve people’s
health and quality of life. However, for many diseases, approved drugs are not yet available
or existing drugs have undesirable side effects, making the pharmaceutical industry strive to
discover new drugs and active compounds. The development of drugs is an expensive
process, which typically starts with the detection of candidate molecules (screening) for an
identified protein target. To this end, the use of high-performance screening techniques has
become a critical issue in order to palliate the high costs. Therefore, the popularity of
computer-based screening (often called virtual screening or in-silico screening) has rapidly
increased during the last decade. A wide variety of Machine Learning (ML) techniques has
been used in conjunction with chemical structure and physicochemical properties for
screening purposes including (i) simple classifiers, (ii) ensemble methods, and more recently
(iii) Multiple Classifier Systems (MCS). In this work, we apply an MCS for virtual screening
(D2-MCS) using circular fingerprints. We applied our technique to a dataset of cannabinoid
CB2 ligands obtained from the ChEMBL database. The HTS collection of Enamine
(1.834.362 compounds), was virtually screened to identify 48.432 potential active molecules
using D2-MCS. This list was subsequently clustered based on circular fingerprints and from
each cluster, the most active compound was maintained. From these, the top 60 were kept,
and 21 novel compounds were purchased. Experimental validation confirmed six highly
active hits (>50% displacement at 10 μM and subsequent Ki determination) and an
additional five medium active hits (>25% displacement at 10 μM). D2-MCS hence provided a
hit rate of 29% for highly active compounds and an overall hit rate of 52%
Characterization of Hypertension Risk Factors at the Committee on Temporary Shelter
Introduction: The health of homeless populations is at risk due to a high prevalence of undiagnosed hypertension (HTN) and cardiovascular disease (CVD). The interaction of housing and socioeconomic status with the risk factors for HTN and CVD remains unclear. Prevention of HTN through a healthy diet, exercise, adequate sleep, and avoidance of tobacco has been well described, but financial limitations and competing priorities for shelter and food make blood pressure (BP) control difficult for this population. By characterizing the risk factors and awareness of hypertension within the homeless population at the Committee on Temporary Shelter Daystation (COTS) in Burlington, Vermont, we may be able to identify promising avenues for therapeutic intervention.https://scholarworks.uvm.edu/comphp_gallery/1226/thumbnail.jp
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