1,205 research outputs found

    The U.S. Gulf of Mexico Pink Shrimp, Farfantepenaeus duorarum, Fishery: 50 Years of Commercial Catch Statistics

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    U.S. Gulf of Mexico, pink shrimp, Farfantepenaeus duorarum, catch statistics have been collected by NOAA’s National Marine Fisheries Service, or its predecessor agency, for over 50 years. Recent events, including hurricanes and oil spills within the ecosystem of the fishery, have shown that documentation of these catch data is of primary importance. Fishing effort for this stock has fluctuated over the 50-year period analyzed, ranging from 3,376 to 31,900 days fished, with the most recent years on record, 2008 and 2009, exhibiting declines up to 90% relative to the high levels recorded in the mid 1990’s. Our quantification of F. duorarum landings and catch rates (CPUE) indicates catch have been below the long-term average of about 12 million lb for all of the last 10 years on record. In contrast to catch and effort, catch rates have increased in recent years, with record CPUE levels measured in 2008 and 2009, of 1,340 and 1,144 lb per day fished, respectively. Our regression results revealed catch was dependent upon fishing effort (F=98.48df=1, 48, p<0.001, r2=0.67), (Catch=1,623,378 + (520) × (effort)). High CPUE’s measured indicate stocks were not in decline prior to 2009, despite the decline in catch. The decrease in catch is attributed in large part to low effort levels caused by economical and not biological or habitat related conditions. Future stock assessments using these baseline data will provide further insights and management advice concerning the Gulf of Mexi

    A Survey of the Causes for Suspensions in the Junior High Schools of the Highline School District

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    This study was undertaken to (1) relate compulsory attendance to the problem of suspension, (2) survey the frequency of and causes for suspensions of junior high school students, (3) survey the course of action taken by the school, school district and/or the parents of the suspended student, and (4) to study the number of cases in which pupils were affected by multiple suspensions

    Simulation of Tail Weight Distributions in Biological Year 1986–2006 Landings of Brown Shrimp, Farfantepenaeus aztecus, from the Northern Gulf of Mexico Fishery

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    Size distribution within re- ported landings is an important aspect of northern Gulf of Mexico penaeid shrimp stock assessments. It reflects shrimp population characteristics such as numerical abundance of various sizes, age structure, and vital rates (e.g. recruitment, growth, and mortality), as well as effects of fishing, fishing power, fishing practices, sampling, size-grading, etc. The usual measure of shrimp size in archived landings data is count (C) the number of shrimp tails (abdomen or edible portion) per pound (0.4536 kg). Shrimp are marketed and landings reported in pounds within tail count categories. Statistically, these count categories are count class intervals or bins with upper and lower limits expressed in C. Count categories vary in width, overlap, and frequency of occurrence within the landings. The upper and lower limits of most count class intervals can be transformed to lower and upper limits (respectively) of class intervals expressed in pounds per shrimp tail, w, the reciprocal of C (i.e. w = 1/C). Age based stock assessments have relied on various algorithms to estimate numbers of shrimp from pounds landed within count categories. These algorithms required un- derlying explicit or implicit assumptions about the distribution of C or w. However, no attempts were made to assess the actual distribution of C or w. Therefore, validity of the algorithms and assumptions could not be determined. When different algorithms were applied to landings within the same size categories, they produced different estimates of numbers of shrimp. This paper demonstrates a method of simulating the distribution of w in reported biological year landings of shrimp. We used, as examples, landings of brown shrimp, Farfantepenaeus aztecus, from the northern Gulf of Mexico fishery in biological years 1986–2006. Brown shrimp biological year, Ti, is defined as beginning on 1 May of the same calendar year as Ti and ending on 30 April of the next calendar year, where subscript i is the place marker for biological year. Biological year landings encompass most if not all of the brown shrimp life cycle and life span. Simulated distributions of w reflect all factors influencing sizes of brown shrimp in the landings within a given biological year. Our method does not require a priori assumptions about the parent distributions of w or C, and it takes into account the variability in width, overlap, and frequency of occurrence of count categories within the landings. Simulated biological year distributions of w can be transformed to equivalent distributions of C. Our method may be useful in future testing of previously applied algorithms and development of new estimators based on statistical estimation theory and the underlying distribution of w or C. We also examine some applications of biological year distributions of w, and additional variables derived from them

    Use of Titanium Mesh Cage in Treating a Subtrochanteric Defect: A Case Report

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    Titanium mesh cages have been used during fixation of segmental defects in long bones; however, use in the subtrochanteric region of the proximal femur is a novel application. We describe a 38-year-old, 330-lb man with a highly comminuted fracture about the right femur after a gunshot wound. Immediate treatment involved use of a cement spacer. Findings of follow-up imaging showed about 26° external rotational deformity and 2-cm limb shortening. To correct the rotational abnormality and limb length discrepancy, a cylindrical titanium mesh cage and custom-made femur locking plate with a cancellous bone autograft were used. Subsequently, successful bridging was obtained across the defect. Titanium mesh cages may be potential alternative devices to use in treating segmental femoral bone defects in the subtrochanteric region of the femur

    Sex Differences in Adult Cognitive Deficits after Adolescent Nicotine Exposure in Rats

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    This study was designed to determine whether deficits in adult serial pattern learning caused by adolescent nicotine exposure persist as impairments in asymptotic performance, whether adolescent nicotine exposure differentially retards learning about pattern elements that are inconsistent with “perfect” pattern structure, and whether there are sex differences in rats’ response to adolescent nicotine exposure as assessed by a serial multiple choice task. The current study replicated the results of our initial report (Fountain, Rowan, Kelley, Willey, & Nolley, 2008) using this task by showing that adolescent nicotine exposure (1.0 mg/kg/day nicotine for 35 days) produced a specific cognitive impairment in male rats that persisted into adulthood at least a month after adolescent nicotine exposure ended. In addition, sex differences were observed even in controls, with additional evidence that adolescent nicotine exposure significantly impaired learning relative to same-sex controls for chunk boundary elements in males and for violation elements in females. All nicotine-induced impairments were overcome by additional training so that groups did not differ at asymptote. An examination of the types of errors rats made indicated that adolescent nicotine exposure slowed learning without affecting rats’ cognitive strategy in the task. This data pattern suggests that exposure to nicotine in adolescence may have impaired different aspects of adult stimulus-response discrimination learning processes in males and females, but left abstract rule learning processes relatively spared in both sexes. These effects converge with other findings in the field and reinforce the concern that adolescent nicotine exposure poses an important threat to cognitive capacity in adulthood

    Summary of the Status of Harvest Mice, Cricetidae: Reithrodontomys, in Arkansas

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    Although four species of harvest mice, Reithrodoniomyx, are known to occur in Arkansas, the distributional status of the genus in the state is poorly understood. Recent museum specimens significantly extend the range of R. megalotix and R. fulvescens in the state. R. megalotis is shown to range south through Phillips Co. in eastern Arkansas, and R. fulvescens is shown to range throughout most of the state, now including most of the Mississippi Alluvial Plain. A new specimen of R. humulis from Delaware Co., Oklahoma, suggests that this species probably ranges throughout northwestern Arkansas. R montanus remains known only from Washington Co. in northwestern Arkansas

    Academic Budget Prioritization in a Shared Governance University

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    Academic program review and budget prioritization in a shared governance environment with transparency and results was critical for Minnesota State University-Mankato, in preparation for forecasted budget reductions. Using an interactive format, this session will review the development of program evaluation metrics, highlight the process and timeline used, present key lessons learned, and provide attendees an opportunity to consider application on their home campus

    Three decades of U.S. Gulf of Mexico white shrimp, Litopenaeus setiferus, commercial catch statistics

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    Gulf of Mexico, white shrimp, Litopenaeus setiferus, catch statistics have been collected by NOAA’s National Marine Fisheries Service for over 50 years. Recent occurrences such as natural and manmade disasters have raised awareness for the need to publish these types of data. Here we report shrimp data collected from 1984 to 2011. These 28 years of catch history are the time series used in the most recent Gulf of Mexico white shrimp stock assessment. Fishing effort for this stock has fluctuated over the period reported, ranging from 54,675 to 162,952 days fished. Catch averaged 55.7 million pounds per year, increasing significantly over the times series. In addition, catch rates have been increasing in recent years, with CPUE levels ranging from 315 lb/day fished in 2002, to 1,175 lb/ day fished in 2008. The high CPUE’s we have measured is one indication that the stock was not in decline during this time period. Consequently, we believe the decline in effort levels is due purely to economic factors. Current stock assessments are now using these baseline data to provide managers with further insights into the Gulf L. setiferus stocks

    Attractor-like dynamics in belief updating in schizophrenia

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    Subjects with a diagnosis of schizophrenia (Scz) overweight unexpected evidence in probabilistic inference: such evidence becomes 'aberrantly salient'. A neurobiological explanation for this effect is that diminished synaptic gain (e.g. hypofunction of cortical N-methyl-D-aspartate receptors) in Scz destabilizes quasi-stable neuronal network states (or 'attractors'). This attractor instability account predicts that i) Scz would overweight unexpected evidence but underweight consistent evidence, ii) belief updating would be more vulnerable to stochastic fluctuations in neural activity, and iii) these effects would correlate.Hierarchical Bayesian belief updating models were tested in two independent datasets (n=80 and n=167, male and female) comprising human subjects with schizophrenia, and both clinical and non-clinical controls (some tested when unwell and on recovery) performing the 'probability estimates' version of the beads task (a probabilistic inference task). Models with a standard learning rate, or including a parameter increasing updating to 'disconfirmatory evidence', or a parameter encoding belief instability were formally compared.The 'belief instability' model (based on the principles of attractor dynamics) had most evidence in all groups in both datasets. Two of four parameters differed between Scz and non-clinical controls in each dataset: belief instability and response stochasticity. These parameters correlated in both datasets. Furthermore, the clinical controls showed similar parameter distributions to Scz when unwell, but were no different to controls once recovered.These findings are consistent with the hypothesis that attractor network instability contributes to belief updating abnormalities in Scz, and suggest that similar changes may exist during acute illness in other psychiatric conditions.SIGNIFICANCE STATEMENTSubjects with a diagnosis of schizophrenia (Scz) make large adjustments to their beliefs following unexpected evidence, but also smaller adjustments than controls following consistent evidence. This has previously been construed as a bias towards 'disconfirmatory' information, but a more mechanistic explanation may be that in Scz, neural firing patterns ('attractor states') are less stable and hence easily altered in response to both new evidence and stochastic neural firing. We model belief updating in Scz and controls in two independent datasets using a hierarchical Bayesian model, and show that all subjects are best fit by a model containing a belief instability parameter. Both this and a response stochasticity parameter are consistently altered in Scz, as the unstable attractor hypothesis predicts
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