6,048 research outputs found

    Gene-flow between populations of cotton bollworm Helicoverpa armigera (Lepidoptera: Noctuidae) is highly variable between years

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    Both large and small scale migrations of Helicoverpa armigera Hübner in Australia were investigated using AMOVA analysis and genetic assignment tests. Five microsatellite loci were screened across 3142 individuals from 16 localities in eight major cotton and grain growing regions within Australia, over a 38-month period (November 1999 to January 2003). From November 1999 to March 2001 relatively low levels of migration were characterized between growing regions. Substantially higher than average gene-flow rates and limited differentiation between cropping regions characterized the period from April 2001 to March 2002. A reduced migration rate in the year from April 2002 to March 2003 resulted in significant genetic structuring between cropping regions. This differentiation was established within two or three generations. Genetic drift alone is unlikely to drive genetic differentiation over such a small number of generations, unless it is accompanied by extreme bottlenecks and/or selection. Helicoverpa armigera in Australia demonstrated isolation by distance, so immigration into cropping regions is more likely to come from nearby regions than from afar. This effect was most pronounced in years with limited migration. However, there is evidence of long distance dispersal events in periods of high migration (April 2001–March 2002). The implications of highly variable migration patterns for resistance management are considered.K.D. Scott, K.S. Wilkinson, N. Lawrence, C.L. Lange, L.J. Scott, M.A. Merritt, A.J. Lowe and G.C Graha

    Climate Change, Water Supply, and Agriculture in the Arid Western United States: Eighty Years of Agricultural Census Observations from Idaho

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    As the population and agricultural development in the U.S. expanded west throughout the 20th century, major water infrastructure projects were initiated in order to meet irrigation demand and to reduce the risk and uncertainty associated with highly variable water supplies.2 Agriculture in the arid and semi-arid western U.S. is particularly vulnerable to variability in water supply, and has evolved to rely heavily on major water infrastructure projects.3 In 2007, of the 57 million acres of irrigated cropland and pastureland in the U.S., nearly three-quarters was in the 17 western-most contiguous states; in 2008, irrigated agriculture applied 91.2 million acre-feet of water, with over four-fifths being used in the arid west

    Housing Market Effects of Inclusionary Zoning

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    This article presents an empirical analysis of the effects of inclusionary zoning policies on housing prices and starts in California during the period from 1988 through 2005. The analysis compares cities with and without such policies and isolates the effects of inclusionary zoning programs by carefully controlling for spatial and temporal conditions, such as the neighborhood or school district within which the house is located and changing market conditions over time. The analysis found that inclusionary zoning policies had measurable effects on housing markets in jurisdictions that adopt them; specifically, the price of single-family houses increases and the size of single-family houses decreases. The analysis also found that, although the cities with such programs did not experience a significant reduction in the rate of single-family housing starts, they did experience a marginally significant increase in multifamily housing starts. The magnitude of this shift varied with the stringency of the inclusionary requirements. Finally, the analysis found that the size of market-rate houses in cities that adopted inclusionary zoning increased more slowly than in cities without such programs. The results are fully consistent with economic theory and demonstrate that inclusionary zoning policies do not come without costs

    The Determinants of Credit Allocations in a Market-Based Trading System: Evidence from the RECLAIM Program

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    This paper examines the determinants of emission credit allocations under the Regional Clean Air Incentives Market (RECLAIM) - a program aimed at reducing nitrogen oxides (NOX) and sulfur oxides (SOX) - in the greater Los Angeles area. Our results suggest that deviations in the allocation of emission credits can be systematically explained by firm-level factors and the location of the facility. Our results also indicate that deviations in the allocation of emission credits may have been made in an attempt to regulate toxics, and that certain industries were protected in the early stages of the program

    Suppression of eukaryotic initiation factor 4E prevents chemotherapy-induced alopecia

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    BACKGROUND: Chemotherapy-induced hair loss (alopecia) (CIA) is one of the most feared side effects of chemotherapy among cancer patients. There is currently no pharmacological approach to minimize CIA, although one strategy that has been proposed involves protecting normal cells from chemotherapy by transiently inducing cell cycle arrest. Proof-of-concept for this approach, known as cyclotherapy, has been demonstrated in cell culture settings. METHODS: The eukaryotic initiation factor (eIF) 4E is a cap binding protein that stimulates ribosome recruitment to mRNA templates during the initiation phase of translation. Suppression of eIF4E is known to induce cell cycle arrest. Using a novel inducible and reversible transgenic mouse model that enables RNAi-mediated suppression of eIF4E in vivo, we assessed the consequences of temporal eIF4E suppression on CIA. RESULTS: Our results demonstrate that transient inhibition of eIF4E protects against cyclophosphamide-induced alopecia at the organismal level. At the cellular level, this protection is associated with an accumulation of cells in G1, reduced apoptotic indices, and was phenocopied using small molecule inhibitors targeting the process of translation initiation. CONCLUSIONS: Our data provide a rationale for exploring suppression of translation initiation as an approach to prevent or minimize cyclophosphamide-induced alopecia.1U01 CA168409 - NCI NIH HHS; P01 CA 87497 - NCI NIH HHS; P30 CA008748 - NCI NIH HHS; MOP-106530 - Canadian Institutes of Health Research; P01 CA013106 - NCI NIH HH

    Feather development genes and associated regulatory innovation predate the origin of Dinosauria

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    The evolution of avian feathers have recently been illuminated by fossils and the identification of genes involved in feather patterning and morphogenesis. However, molecular studies have focused mainly on protein-coding genes. Using comparative genomics and more than 600,000 conserved regulatory elements, we show that patterns of genome evolution in the vicinity of feather genes are consistent with a major role for regulatory innovation in the evolution of feathers. Rates of innovation at feather regulatory elements exhibit an extended period of innovation with peaks in the ancestors of amniotes and archosaurs. We estimate that 86% of such regulatory elements were present prior to the origin of Dinosauria. On the branch leading to modern birds, we detect a strong signal of regulatory innovation near IGFBP2 and IGFBP5, which have roles in body size reduction, and may represent a genomic signature for the miniaturization of dinosaurian body size preceding the origin of flight.Organismic and Evolutionary Biolog

    FISSA: A neuropil decontamination toolbox for calcium imaging signals

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    In vivo calcium imaging has become a method of choice to image neuronal population activity throughout the nervous system. These experiments generate large sequences of images. Their analysis is computationally intensive and typically involves motion correction, image segmentation into regions of interest (ROIs), and extraction of fluorescence traces of each ROI. Out of focus fluorescence from surrounding neuropil and other cells can strongly contaminate the signal assigned to a given ROI. In this study, we introduce the FISSA toolbox (Fast Image Signal Separation Analysis) for neuropil decontamination. Given pre-defined ROIs, the FISSA toolbox automatically extracts the surrounding local neuropil and performs blind-source separation with non-negative matrix factorization. Using both simulated and in vivo data, we show that this toolbox performs similarly or better than existing published methods. FISSA requires only little RAM, allowing for fast processing of large datasets even on a standard laptop. The FISSA toolbox is available in Python, with an option for MATLAB format outputs, and can easily be integrated into existing workflows. It is available from Github and the standard Python repositories

    Quorum-sensing signal production by Agrobacterium vitis strains and their tumor-inducing and tartrate-catabolic plasmids

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    Agrobacterium vitis strains, their tumor-inducing (pTi) and tartrate utilization (pTr) plasmid transconjugants and grapevine tumors were analyzed for the presence of N-acyl-homoserine lactones (AHLs). All wild-type A. vitis strains produced long-chain signals. PCR analysis of the A. vitis long-chain AHL synthase gene, avsI, showed the predicted amplicon. Agrobacterium tumefaciens UBAPF2 harboring various A. vitis pTi plasmids produced N-(3-oxo-octanoyl)-l-homoserine lactone encoded also by pTis of A. tumefaciens. UBAPF2 transconjugants carrying pTrs except for pTrTm4 and pTrAB3, also produced an AHL. UBAPF2 transconjugants carrying pTrAT6, pTrAB4 and pTrRr4 or pTiNi1 produced two additional AHLs not observed in the corresponding wild-type strains. We also provide evidence for in situ production of AHLs in grapevine crown gall tumors of greenhouse and field origi
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