935 research outputs found

    Effect of drive row ground covers on hop (Rosales: Cannabaceae) yard arthropod pests in Vermont, USA

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    Alternatives to pesticides are necessary for the management of hop (Humulus lupulus L.) arthropod pests. The three major arthropod pests in northeastern US hop production include two-spotted spider mite, Tetranychus urticae Koch, hop aphid Phorodon humuli (Schrank), and potato leafhopper, Empoasca fabae Harris. This 3-yr study (2012-2014) in Vermont investigated the effect of flowering ground covers on arthropod pest abundance. Hop cultivars \u27Nugget\u27 and \u27Cascade\u27 were evaluated under a strip-split plot experimental design. Ground cover treatments included 1) Control: mowed red clover (Trifolium pratense) and resident weeds, 2) Clover: red clover, and 3) Diverse: common yarrow (Achillea millefolium), beebalm (Monarda fistulosa), red clover, and annual sunflower (Helianthus annuus). Natural enemies were grouped by associated pest and indicated by our mixed model to be strong predictors of the number of hop aphid and potato leafhopper on hop plants. In year two, ground cover treatment had a significant effect on two-spotted spider mite abundance where fewer two-spotted spider mite were observed on hop plants in Diverse plots. The established, un-mowed Clover treatment was preferred by potato leafhopper over Diverse ground cover and hop plants. This revealed the potential for clover ground cover to serve as a trap crop for potato leafhopper management in northeastern hop yards. Our findings are evidence that ground covers implemented for conservation biological control may serve more specific pest management functions instead of or in addition to boosting top-down pest pressure

    Weather Information and Decision-Support Tool Needs Assessment

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    University of Maine researchers developed three commodity-specific grower focus groups (lowbush blueberry, apple, mixed vegetable) to discuss and survey 1) current access to weather information, and 2) interest in weather-based decision support tools. NOAA National Weather Service (30%) (n=47) was most commonly cited as a weather information source. Growers ranked greater forecast accuracy (31%) and localization (19%) (n=48) as highest priorities. Only 34% of growers reported current use of weather-based decision support tools, but 86% expressed interest in future use (n=134). The project team is using grower input to improve weather data access and decision-support tools for Maine farmers

    The Jolt-Pack Fabrication of Special Ceramic Ware

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    The jolt-pack method for fabrication of refractory crucibles and other shapes is described. The particle size distribution of the material to be packed has been found to be an important consideration in this method. Data are presented on packing densities of various graded fractions of beryllia and the development of a dense-packing mixture is described

    Collecting biomedical and social data in a longitudinal survey: A comparison of two approaches

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    The inclusion of the collection of biomeasures within social surveys, and longitudinal surveys in particular, is becoming ever more common. Combining objective measurements of health with detailed information about lifestyles and behaviour collected over long periods of time offers enormous research potential. Studies that combine an interview with the collection of biomeasures can be conducted in various ways. One model is that field interviewers make initial contact with participants, conduct the interviews and arrange follow-up visits for a nurse to collect the biomeasures. Alternatively, field interviewers can be trained to collect biomeasures, but there remain questions about whether the quality of data collected is comparable to that collected by a nurse. Other studies invite participants to visit clinics, but this can be very costly in a large-scale national study. There is no consensus on the optimal strategy for combining a social survey with the collection of biomeasures. The 1970 British Cohort Study (BCS70) is a longitudinal birth cohort study which began in 1970. The 11th sweep of the study began in 2016, when study members were aged 46, and included an interview component alongside the collection of a range of biomeasures. The first phase of fieldwork was conducted using a new approach where nurses conducted all of the data collection. Midway through fieldwork BCS70 switched to a two-stage approach where interviews were conducted by interviewers followed by a separate nurse visit. This presented a unique opportunity to evaluate the success of the two approaches

    Rap1 binding and a lipid-dependent helix in talin F1 domain promote integrin activation in tandem.

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    Rap1 GTPases bind effectors, such as RIAM, to enable talin1 to induce integrin activation. In addition, Rap1 binds directly to the talin1 F0 domain (F0); however, this interaction makes a limited contribution to integrin activation in CHO cells or platelets. Here, we show that talin1 F1 domain (F1) contains a previously undetected Rap1-binding site of similar affinity to that in F0. A structure-guided point mutant (R118E) in F1, which blocks Rap1 binding, abolishes the capacity of Rap1 to potentiate talin1-induced integrin activation. The capacity of F1 to mediate Rap1-dependent integrin activation depends on a unique loop in F1 that has a propensity to form a helix upon binding to membrane lipids. Basic membrane-facing residues of this helix are critical, as charge-reversal mutations led to dramatic suppression of talin1-dependent activation. Thus, a novel Rap1-binding site and a transient lipid-dependent helix in F1 work in tandem to enable a direct Rap1-talin1 interaction to cause integrin activation

    March1-dependent modulation of donor MHC II on CD103+ dendritic cells mitigates alloimmunity.

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    In transplantation, donor dendritic cells (do-DCs) initiate the alloimmune response either by direct interaction with host T cells or by transferring intact donor MHC to host DCs. However, how do-DCs can be targeted for improving allograft survival is still unclear. Here we show CD103+ DCs are the major do-DC subset involved in the acute rejection of murine skin transplants. In the absence of CD103+ do-DCs, less donor MHC-II is carried to host lymph nodes, fewer allogenic T cells are primed and allograft survival is prolonged. Incubation of skin grafts with the anti-inflammatory mycobacterial protein DnaK reduces donor MHC-II on CD103+DCs and prolongs graft survival. This effect is mediated through IL-10-induced March1, which ubiquitinates and decreases MHC-II levels. Importantly, in vitro pre-treatment of human DCs with DnaK reduces their ability to prime alloreactive T cells. Our findings demonstrate a novel therapeutic approach to dampen alloimmunity by targeting donor MHC-II on CD103+DCs
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