227 research outputs found

    Tall Fescue (\u3cem\u3eFestuca arundinacea\u3c/em\u3e) Stockpiling Response to N Fertilizer in Southern Virginia as Affected by Biological Soil Quality

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    Cattlemen in the eastern USA profitably utilize endophyte-infected tall fescue (Festuca arundinacea) for fall-stockpiled winter grazing. Ergot alkaloid concentration in fescue tends to decline in winter. This improves the quality of fescue for grazing when the supply of other forage becomes limited on most farms. Tall fescue dry matter yields generally respond favorably to nitrogen (N) inputs, but response can be limited with summer application due to accumulation of biologically available N in soil. Research is needed to characterize a diversity of pastures for response to N fertilizer during fall stockpiling. Biological soil quality can be estimated with a simple measure of soil respiration following rewetting of dried soil (Franzluebbers et al., 2000). The flush of CO2 following rewetting of dried soil has been related to the quantity of N mineralized during longer term incubations (Franzluebbers and Haney, 2006) and to N uptake in field studies of forage growth (Haney et al., 2001). Soil was collected from a set of pastures in southern Virginia to characterize biological soil quality and determine dry matter yield response to fertilizer N inputs

    Effects of acute and chronic interval sprint exercise performed on a manually propelled treadmill on upper limb vascular mechanics in healthy young men

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    © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society. Interval sprint exercise performed on a manually propelled treadmill, where the hands grip the handle bars, engages lower and upper limb skeletal muscle, but little is known regarding the effects of this exercise modality on the upper limb vasculature. We tested the hypotheses that an acute bout of sprint exercise and 6 weeks of training induces brachial artery (BA) and forearm vascular remodeling, favoring a more compliant system. Before and following a single bout of exercise as well as 6 weeks of training three types of vascular properties/methodologies were examined in healthy men: (1) stiffness of the entire upper limb vascular system (pulse wave velocity (PWV); (2) local stiffness of the BA; and (3) properties of the entire forearm vascular bed (determined by a modified lumped parameter Windkessel model). Following sprint exercise, PWV declined (P \u3c 0.01), indices of BA stiffness did not change (P ≥ 0.10), and forearm vascular bed compliance increased and inertance and viscoelasticity decreased (P ≤ 0.03). Following manually propelled treadmill training, PWV remained unchanged (P = 0.31), indices of BA stiffness increased (P ≤ 0.05) and forearm vascular bed viscoelasticity declined (P = 0.02), but resistance, compliance, and inertance remained unchanged (P ≥ 0.10) compared with pretraining values. Sprint exercise induced a more compliant forearm vascular bed, without altering indices of BA stiffness. These effects were transient, as following training the forearm vascular bed was not more compliant and indices of BA stiffness increased. On the basis of these data, we conclude that adaptations to acute and chronic sprint exercise on a manually propelled treadmill are not uniform along the arterial tree in upper limb

    Toward Early-Warning Detection of Gravitational Waves from Compact Binary Coalescence

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    Rapid detection of compact binary coalescence (CBC) with a network of advanced gravitational-wave detectors will offer a unique opportunity for multi-messenger astronomy. Prompt detection alerts for the astronomical community might make it possible to observe the onset of electromagnetic emission from (CBC). We demonstrate a computationally practical filtering strategy that could produce early-warning triggers before gravitational radiation from the final merger has arrived at the detectors.Comment: 16 pages, 7 figures, published in ApJ. Reformatted preprint with emulateap

    Complex interactions of HIV-1 nucleocapsid protein with oligonucleotides

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    The HIV-1 nucleocapsid (NC) protein is a small, basic protein containing two retroviral zinc fingers. It is a highly active nucleic acid chaperone; because of this activity, it plays a crucial role in virus replication as a cofactor during reverse transcription, and is probably important in other steps of the replication cycle as well. We previously reported that NC binds with high-affinity to the repeating sequence d(TG)(n). We have now analyzed the interaction between NC and d(TG)(4) in considerable detail, using surface plasmon resonance (SPR), tryptophan fluorescence quenching (TFQ), fluorescence anisotropy (FA), isothermal titration calorimetry (ITC) and electrospray ionization Fourier transform mass spectrometry (ESI-FTMS). Our results show that the interactions between these two molecules are surprisngly complex: while the K(d) for binding of a single d(TG)(4) molecule to NC is only ∼5 nM in 150 mM NaCl, a single NC molecule is capable of interacting with more than one d(TG)(4) molecule, and conversely, more than one NC molecule can bind to a single d(TG)(4) molecule. The strengths of these additional binding reactions are quantitated. The implications of this multivalency for the functions of NC in virus replication are discussed

    The Combination of BH3-Mimetic ABT-737 with the Alkylating Agent Temozolomide Induces Strong Synergistic Killing of Melanoma Cells Independent of p53

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    Metastatic melanoma has poor prognosis and is refractory to most conventional chemotherapies. The alkylating agent temozolomide (TMZ) is commonly used in treating melanoma but has a disappointing response rate. Agents that can act cooperatively with TMZ and improve its efficacy are thus highly sought after. The BH3 mimetic ABT-737, which can induce apoptosis by targeting pro-survival Bcl-2 family members, has been found to enhance the efficacy of many conventional chemotherapeutic agents in multiple cancers. We found that combining TMZ and ABT-737 induced strong synergistic apoptosis in multiple human melanoma cell lines. When the drugs were used in combination in a mouse xenograft model, they drastically reduced tumor growth at concentrations where each individual drug had no significant effect. We found that TMZ treatment elevated p53 levels, and that the pro-apoptotic protein Noxa was elevated in TMZ/ABT-737 treated cells. Experiments with shRNA demonstrated that the synergistic effect of TMZ and ABT-737 was largely dependent on Noxa. Experiments with nutlin-3, a p53 inducer, demonstrated that p53 induction was sufficient for synergistic cell death with ABT-737 in a Noxa-dependent fashion. However, p53 was not necessary for TMZ/ABT-737 synergy as demonstrated by a p53-null line, indicating that TMZ and ABT-737 together induce Noxa in a p53-independent fashion. These results demonstrate that targeting anti-apoptotic Bcl-2 members is a promising method for treating metastatic melanoma, and that clinical trials with TMZ and Bcl-2 inhibitors are warranted

    Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A

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    On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anti-Coincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory. The probability of the near-simultaneous temporal and spatial observation of GRB 170817A and GW170817 occurring by chance is 5.0 × 10 -8 . We therefore confirm binary neutron star mergers as a progenitor of short GRBs. The association of GW170817 and GRB 170817A provides new insight into fundamental physics and the origin of short GRBs. We use the observed time delay of (+1.74±0.05)between GRB 170817A and GW170817 to: (i) constrain the difference between the speed of gravity and the speed of light to be between -3 × 10 -15 and +7 × 10 -16 times the speed of light, (ii) place new bounds on the violation of Lorentz invariance, (iii) present a new test of the equivalence principle by constraining the Shapiro delay between gravitational and electromagnetic radiation. We also use the time delay to constrain the size and bulk Lorentz factor of the region emitting the gamma-rays. GRB 170817A is the closest short GRB with a known distance, but is between 2 and 6 orders of magnitude less energetic than other bursts with measured redshift. A new generation of gamma-ray detectors, and subthreshold searches in existing detectors, will be essential to detect similar short bursts at greater distances. Finally, we predict a joint detection rate for the Fermi Gamma-ray Burst Monitor and the Advanced LIGO and Virgo detectors of 0.1-1.4 per year during the 2018-2019 observing run and 0.3-1.7 per year at design sensitivity

    Pennsylvania Folklife Vol. 12, No. 3

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    • Antiques in Dutchland • Antique or Folk Art: Which? • Pennsylvania Dutch • Amish Barn Raisings • Building a Pennsylvania Barn • Water Witching • Amish Family Life: A Sociologist\u27s Analysis • Straw Hat Making Among the Old Order Amish • Bread and Apple-Butter Day • Schnitz in the Pennsylvania Folk-Culture • Dutch Country Scarecrows • The Man Who Was Buried Standing Up • Living Occult Practices in Dutch Pennsylvania • Farewell to Olliehttps://digitalcommons.ursinus.edu/pafolklifemag/1011/thumbnail.jp

    Pennsylvania Folklife Vol. 12, No. 2

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    • The Township Weavers of Pennsylvania • Amish Funerals • The Bush-Meeting Dutch • Steep Roofs and Red Tiles • Carpet Rag Parties • Fences in Rural Pennsylvania • Folk Festival Program • A Study of the Dialect Terminology of the Plain Sects of Montgomery County, Pa. • Henry Chapman Mercer, Pennsylvania Folklife Pioneer • The Glingelsock • Sauerkraut in the Pennsylvania Folk-Culture • Collectaneahttps://digitalcommons.ursinus.edu/pafolklifemag/1010/thumbnail.jp
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