2,372 research outputs found

    A transient Markov chain with finitely many cutpoints

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    We give an example of a transient reversible Markov chain that almost surely has only a finite number of cutpoints. We explain how this is relevant to a conjecture of Diaconis and Freedman and a question of Kaimanovich. We also answer Kaimanovich's question when the Markov chain is a nearest-neighbor random walk on a tree.Comment: Published in at http://dx.doi.org/10.1214/193940307000000365 the IMS Collections (http://www.imstat.org/publications/imscollections.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

    Sequential primed kinases create a damage-responsive phosphodegron on Eco1.

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    Sister-chromatid cohesion is established during S phase when Eco1 acetylates cohesin. In budding yeast, Eco1 activity falls after S phase due to Cdk1-dependent phosphorylation, which triggers ubiquitination by SCF(Cdc4). We show here that Eco1 degradation requires the sequential actions of Cdk1 and two additional kinases, Cdc7-Dbf4 and the GSK-3 homolog Mck1. These kinases recognize motifs primed by previous phosphorylation, resulting in an ordered sequence of three phosphorylation events on Eco1. Only the latter two phosphorylation sites are spaced correctly to bind Cdc4, resulting in strict discrimination between phosphates added by Cdk1 and by Cdc7. Inhibition of Cdc7 by the DNA damage response prevents Eco1 destruction, allowing establishment of cohesion after S phase. This elaborate regulatory system, involving three independent kinases and stringent substrate selection by a ubiquitin ligase, enables robust control of cohesion establishment during normal growth and after stress

    Proactive Planning to Address Budgetary Shortfalls: The Rutgers Cooperative Extension Experience

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    The Cooperative Extension System has experienced significant fiscal challenges during the past three decades, necessitating proactive responses to enhance revenue received from federal, state, and local funding sources. This article presents an overview of Extension budgetary challenges and the work of the Rutgers Cooperative Extension (RCE) Revenue Enhancement Task Force (RETF). The RETF was charged with developing guiding principles and recommendations with respect to cost recovery and revenue enhancement and tools to help RCE employees think and act like intrapreneurs. The article concludes with lessons learned and recommendations for Cooperative Extension organizations planning similar revenue enhancement initiatives

    Lesser mealworm (Alphitobius diaperinus) association with Enterococcus cecorum and pest management considerations for this pest in broiler houses

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    The lesser mealworm Alphitobius diaperinus is a worldwide pest of poultry. Lesser mealworms transmit various viral and bacterial pathogens. The economic impact of the beetle is a problem for broiler growers. Consumption of the beetle by young birds leads to reduced weight gain and gastrointestinal issues. The boring out of insulation by the larvae to prepare a pupation site reduces the insulating abilities and increases energy costs. This study indicates that the lesser mealworm is a mechanical vector for the causative agent of enterococcus spondylitis (ES) disease in poultry. With 30 min of exposure to Enterococcus cecorum inoculated agar, the lesser mealworm was able to transfer bacteria phenotypically similar to E. cecorum to sterile agar plates within 30 min of exposure. Future research should expand beyond mechanical transmission to determine the vector competency of this pest to E. cecorum. A new set of primers was developed for detection of E. cecorum by use of PCR. A Knowledge, Attitudes, and Practices (KAP) survey was conducted on broiler growers in one county of Oklahoma. Eighty-three percent of growers observed A. diaperinus present in their broiler houses. Ninety-two percent of growers monitor their houses for pests. Fifty-eight percent of the growers targeted beetles for their insecticide treatments, mostly targeting under feeders and along the walls. Our study reveals that 67% of growers windrowed their litter. Beetles were exposed for a sublethal amount of time (LT20) to various insecticide formulations. The fecundity and hatched larvae were counted over 30 d beginning 3 wk after sublethal insecticide exposure. Mean number of eggs by treatment was highest in the first 6 d of the experiment. No insecticide treatment had less eggs or larvae than the control in this experiment, and some treatments had significantly greater numbers of eggs and larvae. On days 0-6, Onslaught (Esfenvelerate) had the greatest mean of 31.75 eggs per mating pair and control had the least with a mean of 6.94 eggs per mating pair. More research is needed to determine if the increase in fecundity observed will result in an increase in population rate

    Insecticide Resistance of Alphitobius diaperinus (Coleoptera: Tenebrionidae) to β-Cyfluthrin And Associated Heat Tolerance

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    The lesser mealworm Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) is an important economic pest to poultry producers globally that cause structural damage and spread pathogens to poultry. Adult lesser mealworms were collected from three farms in Mt. Pleasant, TX, USA (A-C) and three farms in Franklin, TX, USA (D-F) in order to assess insecticide resistance across populations, as well its relationship to heat tolerance. Filter papers were treated with a range of doses of the active ingredient (AI) β-Cyfluthrin. Farms B and E displayed much higher LD_(50) of 0.320 mg/mL and 0.627 mg/mL respectively compared to the remaining four farms, which ranged from 0.048-0.161mg/mL. In addition, a field bioassay was conducted to determine adult beetle susceptibility to label rates of formulated permethrin, Vector Ban Plus™ and a pyrethroid, Tempo SC Ultra™. These insecticides were applied to commonly found surfaces in poultry operations (concrete, wood chip particle board, and pressure treated wood). Adult beetles were exposed to the treated surfaces for 2 h and then placed in untreated sterile petri dishes. “Mortality” refers to mortality and morbidity recorded together at 2, 24, and 48 h post-exposure for both bioassays. Insecticide resistance varied greatly based on observation period and compound. The range of mean mortalities measured at 2 h regardless of surface type for Tempo SC Ultra™ was 58-100% and for Vector Ban Plus™ 17-100%. The mean mortality range at 24 h regardless of surface for Tempo SC Ultra™ (91-100%) had less than 10% variation, while Vector Ban Plus™ (0.00-49.73%) displayed almost 50% variation. The mean mortality range at 48 h regardless of surface for Tempo SC Ultra™ (72-100%) showed high knockdown and increased in variation by 30%, and Vector Ban Plus™ (0-29%) had a similar variation, but with low knockdown. Mortality was similar for Tempo SC Ultra™ for each substrate. β-Cyfluthrin (AI) had varying effectiveness depending on the population’s resistance levels, however all the farms tested had LD_(50) well above the equivalent formulation dosage of 0.02mg/mL. The β-Cyfluthrin formulation had high mortality on all the surfaces tested highlighting the importance of the other ingredients in a formulation. Heat tolerance experiments were conducted on the F_(1) progeny of populations B, D, and E (n=14). The heat shock results were inconclusive. Modification to the experimental design may be needed to yield comparable results

    Using competency-based education to equip the primary health care workforce to manage chronic disease

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    The research reported in this paper is a project of the Australian Primary Health Care Research Institute, which is supported by a grant from the Australian Government Department of Health and Ageing under the Primary Health Care Research, Evaluation and Development Strategy

    Mineral Acquisition from Clay by Budongo Forest Chimpanzees

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    Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consumed indicates that it takes the form of kaolinite. We discuss the contribution of clay geophagy to the mineral intake of the Sonso chimpanzees and show that clay eaten using leaf sponges is particularly rich in minerals. We show that termite mound soil, also regularly consumed, is rich in minerals. We discuss the frequency of clay and termite soil geophagy in the context of the disappearance from Budongo Forest of a formerly rich source of minerals, the decaying pith of Raphia farinifera palms
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