The Life History and Population Dynamics of Southern Flounder

Southern Flounder, Paralichthys lethostigma, are a coastal, estuarine-dependent flatfish species that inhabits the Southeastern US Atlantic Ocean and Gulf of Mexico. Throughout their range, Southern Flounder are exploited by both commercial and recreational fisheries. Recently, numerous sources have expressed concerns about Southern Flounder populations, with stock assessments indicating declines in spawning stock biomass and recruitment. To estimate life history traits needed for informed management, such as age, growth, and maturity, I collected 327 Southern Flounder from Louisiana and obtained 14,184 historical records from the Louisiana Department of Wildlife and Fisheries. Using a von Bertalanffy growth equation in a Bayesian hierarchical framework, I found local-scale differences in growth between estuaries and parameter differences from previous studies. Logistic regression estimated an L50 of 353mm, which is over 100mm larger than a previous estimate for Louisiana. Finally, I evaluated the variability in life history estimates from historical studies throughout the range. I then used generalized additive models to quantify age-0 relative abundance trends in Texas, Louisiana, Alabama, Florida, South Carolina, and North Carolina. Of 31 estuaries modeled, a significant decline was found to be occurring in 19, indicating a range-wide population decline. Environmental covariates including growing degree days (GDD), wind, and winter severity were tested to explain the trends. GDD and winter severity appeared to have localized effects on Southern Flounder abundance, while wind was a significant explanatory factor in all 21 estuaries with available wind data. Additionally, I show that Southern Flounder are being exposed to warmer temperatures as they develop, which could cause sex ratios to masculinize. This research addresses fishery management needs and seeks to explain the population dynamics of Southern Flounder in the Gulf of Mexico and US Southeastern Atlantic

THE STRUCTURE, PERFORMANCE, AND SUSTAINABILITY OF AGRICULTURE IN THE MOUNTAIN REGION

Farmers in the Mountain Region-in both metro and nonmetro areas-face growth in population and nonfarm employment that affects land use and how farmers operate their businesses. Even in remote locations, people moving to amenity areas may result in farmers changing their operations. Sustainable agriculture, already practiced by Mountain Region farmers to some extent, may help farming to continue. Nonfarm people also have an interest in the continuation of agriculture and the adaptation of sustainable practices, in order to help preserve the amenities that make the region attractive to migrants. Growth in the region does provide some benefits to farmers, however. Growth can help keep the value of farmland up through nonfarm demand for land. In addition, the greater availability of jobs means that off-farm work is available to households operating farms. Off-farm work is particularly important, given the concentrated distribution of farm income.Production Economics,

Rating the Financial Health of U.S. Production Agriculture using Synthetic Credit Rating

Agribusiness, Agricultural and Food Policy, Production Economics,

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

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

West Nile Virus Viremia in Eastern Chipmunks (Tamias striatus) Sufficient for Infecting Different Mosquitoes

Chipmunks might play a role in enzootic WNV cycles and be an amplifying host for mosquitoes that infect humans

Pdl1 Is a Putative Lipase that Enhances Photorhabdus Toxin Complex Secretion

The Toxin Complex (TC) is a large multi-subunit toxin first characterized in the insect pathogens Photorhabdus and Xenorhabdus, but now seen in a range of pathogens, including those of humans. These complexes comprise three protein subunits, A, B and C which in the Xenorhabdus toxin are found in a 4∶1∶1 stoichiometry. Some TCs have been demonstrated to exhibit oral toxicity to insects and have the potential to be developed as a pest control technology. The lack of recognisable signal sequences in the three large component proteins hinders an understanding of their mode of secretion. Nevertheless, we have shown the Photorhabdus luminescens (Pl) Tcd complex has been shown to associate with the bacteria's surface, although some strains can also release it into the surrounding milieu. The large number of tc gene homologues in Pl make study of the export process difficult and as such we have developed and validated a heterologous Escherichia coli expression model to study the release of these important toxins. In addition to this model, we have used comparative genomics between a strain that releases high levels of Tcd into the supernatant and one that retains the toxin on its surface, to identify a protein responsible for enhancing secretion and release of these toxins. This protein is a putative lipase (Pdl1) which is regulated by a small tightly linked antagonist protein (Orf53). The identification of homologues of these in other bacteria, linked to other virulence factor operons, such as type VI secretion systems, suggests that these genes represent a general and widespread mechanism for enhancing toxin release in Gram negative pathogens

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

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

Software Development Standard Processes (SDSP)

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