145 research outputs found

    An Error-Components Three-Stage Least-Squares Model of Investment Allocation by Farm Households

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    This paper is an assessment of patterns of investment by farm households via an econometric model adapted from a land allocation approach of Holt (1999). This analysis will shed light on the importance of different classes of assets to farm household well-being, and show the reaction of farm households to a variety of market, international and government effects.Farm Management,

    Genetic aspects of the effects of methylmercury in mice: The incidence of cleft palate and concentrations of adenosine 3β€²:5β€² cyclic monophosphate in tongue and palatal shelf

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    Concentrations of adenosine 3β€²:5β€² cyclic monophosphate (cAMP) were measured in the tongues and palates of 14.5-day-old fetuses from control and methylmercury-treated mothers of four inbred lines of mice which represent the four possible combinations of two H-2 alleles and two residual genetic backgrounds. The incidence of cleft palate in fetuses from control and methylmercury-treated mothers was also examined. The H-2 alleles significantly affected the degree of reduction of cAMP concentration in palates seen in fetuses from mothers treated with methylmercury. Neither the H-2 allele nor the residual genetic background played a role in the effect of methylmercury on cAMP concentrations in fetal tongues. The magnitude of increase in the incidence of cleft palate with methylmercury treatment was approximately the same for all lines. Thus, methylmercury-induced cleft palate may not be mediated by the reduction of cAMP. Finally, fetuses with cleft lip had increased palatal cAMP levels, whether or not they were from control or methylmercury treated mothers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38148/1/1420230315_ftp.pd

    Measuring and Analyzing Farm Financial Stress

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    The financial health of the agricultural economy has been excellent for the past few years, especially with farm income reaching record levels. However, the U.S. economy has experienced a recession and a credit crisis. Although the U.S. farm sector has been mostly shielded from the economic downturn, farm financial stress is still possible under current conditions. Are some U.S. farm businesses, especially those with term debt, poised to experience significant financial stress in 2010? We use the Agricultural Resource Management Survey (ARMS), sponsored jointly by USDA’s Economic Research Service (ERS) and National Agricultural Statistical Service, to help answer this question.Off-farm income, farm investment, double hurdle, Agricultural Finance, Financial Economics, D1, J2,

    Incorporating metapopulation Dynamics to Inform Invasive Species Management: Evaluating Bighead and Silver Carp Control Strategies in the Illinois River

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    1. Invasive species management can benefit from predictive models that incorporate spatially explicit demographics and dispersal to guide resource allocation decisions. 2. We used invasive bigheaded carps (Hypophthalmichthys spp.) in the Illinois River, USA as a case study to create a spatially explicit model to evaluate the allocation of future management efforts. Specifically, we compared additional harvest (e.g. near the invasion front vs. source populations) and enhanced movement deterrents to meet the management goal of reducing abundance at the invasion front. 3. We found additional harvest in lower river pools (i.e. targeting source populations) more effectively limited population sizes upriver at the invasion front compared to allocating the same harvest levels near the invasion front. Likewise, decreasing passage (i.e. lock and dam structures) at the farthest, feasible downriver location limited invasion front population size more than placing movement deterrents farther upriver. 4. Synthesis and applications. Our work highlights the benefits of adopting a multipronged approach for invasive species management, combining suppression of source populations with disrupting movement between source and sink populations thereby producing compounding benefits for control. Our results also demonstrate the importance of considering metapopulation dynamics for invasive species control programs when achieving long-term management goals

    The properties of proton-proton interactions between 100 and 1000 GeV from a cosmic-ray experiment

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    Proton-proton interactions above 100 GeV have been studied in an experiment using cosmic-ray protons interacting in a liquid hydrogen target. From several hundred hydrogen interactions, it has been learned that: (a) the total inelastic pp cross section is not changing significantly with energy above 30 GeV; (b) the multiplicity distributions of charged prongs agree with a Poisson distribution in charged-particle pairs; (c) the average charged prong multiplicity increases as 1 n s; (d) the angular distribution of charged particles agrees with a c.m. momentum distribution of charged particles that varies as exp exp [-8 pT2-8x2] d3p/E (where X = pL/po) and a nucleon distribution that varies as 10x exp [-3 pT2] d3p/E for 0.05 < x < 0.85. Further properties of the angular distributions, characteristics of the ionization calorimeter, the cross section in iron, and other features of the data are reported.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34084/1/0000363.pd

    Structural and Functional Profiling of the Human Histone Methyltransferase SMYD3

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    The SET and MYND Domain (SMYD) proteins comprise a unique family of multi-domain SET histone methyltransferases that are implicated in human cancer progression. Here we report an analysis of the crystal structure of the full length human SMYD3 in a complex with an analog of the S-adenosyl methionine (SAM) methyl donor cofactor. The structure revealed an overall compact architecture in which the β€œsplit-SET” domain adopts a canonical SET domain fold and closely assembles with a Zn-binding MYND domain and a C-terminal superhelical 9 Ξ±-helical bundle similar to that observed for the mouse SMYD1 structure. Together, these structurally interlocked domains impose a highly confined binding pocket for histone substrates, suggesting a regulated mechanism for its enzymatic activity. Our mutational and biochemical analyses confirm regulatory roles of the unique structural elements both inside and outside the core SET domain and establish a previously undetected preference for trimethylation of H4K20

    The DOCK Protein Sponge Binds to ELMO and Functions in Drosophila Embryonic CNS Development

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    Cell morphogenesis, which requires rearrangement of the actin cytoskeleton, is essential to coordinate the development of tissues such as the musculature and nervous system during normal embryonic development. One class of signaling proteins that regulate actin cytoskeletal rearrangement is the evolutionarily conserved CDM (C. elegans Ced-5, human DOCK180, Drosophila Myoblast city, or Mbc) family of proteins, which function as unconventional guanine nucleotide exchange factors for the small GTPase Rac. This CDM-Rac protein complex is sufficient for Rac activation, but is enhanced upon the association of CDM proteins with the ELMO/Ced-12 family of proteins. We identified and characterized the role of Drosophila Sponge (Spg), the vertebrate DOCK3/DOCK4 counterpart as an ELMO-interacting protein. Our analysis shows Spg mRNA and protein is expressed in the visceral musculature and developing nervous system, suggesting a role for Spg in later embryogenesis. As maternal null mutants of spg die early in development, we utilized genetic interaction analysis to uncover the role of Spg in central nervous system (CNS) development. Consistent with its role in ELMO-dependent pathways, we found genetic interactions with spg and elmo mutants exhibited aberrant axonal defects. In addition, our data suggests Ncad may be responsible for recruiting Spg to the membrane, possibly in CNS development. Our findings not only characterize the role of a new DOCK family member, but help to further understand the role of signaling downstream of N-cadherin in neuronal development

    Software Development Standard Processes (SDSP)

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    A JPL-created set of standard processes is to be used throughout the lifecycle of software development. These SDSPs cover a range of activities, from management and engineering activities, to assurance and support activities. These processes must be applied to software tasks per a prescribed set of procedures. JPL s Software Quality Improvement Project is currently working at the behest of the JPL Software Process Owner to ensure that all applicable software tasks follow these procedures. The SDSPs are captured as a set of 22 standards in JPL s software process domain. They were developed in-house at JPL by a number of Subject Matter Experts (SMEs) residing primarily within the Engineering and Science Directorate, but also from the Business Operations Directorate and Safety and Mission Success Directorate. These practices include not only currently performed best practices, but also JPL-desired future practices in key thrust areas like software architecting and software reuse analysis. Additionally, these SDSPs conform to many standards and requirements to which JPL projects are beholden
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