The Influence of Lobster Trap Escape Gaps on Capture and Behavior of the Spiny Lobster, Panulirus argus (Latreille)

Interest in the potential usefulness of lobster trap escape gaps in the Florida spiny lobster fishery prompted an independent examination of their influence on capture and behavior of the spiny lobster, Panulirus argus. A trapping study was conducted off Southeastern Florida during 1984/1985 using control traps, and traps with escape gap openings of 51, 54, and 57 mm. The 51 mm escape gap caught significantly more legal lobsters than any other trap, while the 54 and 57 mm escape gap caught significantly fewer sublegal lobsters. Carapace lengths of lobsters increased as escape gap width increased. The impact of escape gaps on behavior of Panulirus argus was examined through field and laboratory observations. Lobsters with a carapace length of 75 mm or less were observed entering and exiting through a 51 mm escape gap. Legal lobsters (≥76 mm CL) were unable to escape from the trap. Dominance interaction or agonistic behavior were postulated to affect catch rates in escape gap traps. Direct observations indicate they do not appear to be a factor influencing catch rates of lobsters in traps with escape gaps. It is hypothesized that the escape gap acts as an auxiliary opening, enhancing the potential of capturing a sublegal lobster

Deliberate Response Falsification on Corresponding Subtests of Two Tests of Intelligence: Indicators for Simulating Mental Retardation

Among concerns inherent in psychological testing is the possibility that examinees might perform less than accurately or honestly when responding to test items (Lezak, 1983). In context of some legal proceedings, individuals may stand to gain by performing poorly on physiological tests (Anastasti, 1988). For example, defendants could attempt to falsify their answers to impersonate an individual with mental retardation for the purpose of raising issues of incompetence to stand trial, nonresponsibility, or mitigation. In some states, a finding of mental retardation may mean the difference between a life sentence and execution for a defendant convicted of a capital crime. The validity and reliability of intelligence testing instruments are of vital importance in determining the existence of mental retardation. The purpose of this study was to examine the possibility that subjects could deliberately and successfully falsify responses on corresponding subtests of two major intelligence tests, the Wechsler Adult Intelligence Scalre-Revised (WAIS-R) (Whechsler, 1981) and the Stanford-Binet Intelligence Scale-Fourth Edition (SB:FE) (Thorndike, Hagen, and Sattler, 1986a) to simulate the existence of mental retardation. Subjects were administered and Comprehension subtests from both the WAIS-R and the SB:FE and instructed to perform less accurately and less honestly than their capabilities naturally provide. A control procedure was also administered. Corresponding standardized scores (Normal Curve Equivalency [NCE]) were compared for significant differences using a one-factor, repeated measure ANOVA. Latency periods recorded and analyzed using descriptive statistics an an ANOVA, and qualitative data obtained in debriefing sessions were also reported. Statistical analyses indicated that subjects were unable to score similarly on both tests when simulating mental retardation (

Aspects of Phytoplankton Chlorophyll A Carbon-Specific Growth Rates, and the Distributions of Chlorophyll A and Primary Productivity in Relation to Water Column Structure in the Eastern North Atlantic Ocean

This dissertation consists of three chapters, two of which are presented in manuscript form. Chapter One is an introduction and review of the measurement of phytoplankton chlorophyll a carbon-specific growth rates. Chapter Two consists of the manuscript ASPECTS OF CHLOROPHYLL a CARBONSPECIFIC GROWTH RATE IN THE EASTERN NORTH ATLANTIC OCEAN. It has been formatted in accordance with the specifications of the oceanographic journal Marine Ecology Progress Series. In Chapter Two, an evaluation of the short-term kinetics of the labeling time of natural phytoplankton populations in different oceanic regions showed that chI a labeling varied in relation to both environmental conditions and latitude. At subtropical stations rapid short-term increases in the activity of chI a were coincident with large (\u3e 38%) increases in total photosynthetically available radiation. The rapid short-term increases resulted in overestimates of the growth rate. Overall though, a strong correlation between chI a carbon-specific growth rates and independently-derived assimilation numbers was evident. This strong correlation, particularly with end-of-day samples suggests that the chI a labeling technique for phytoplankton carbon-specific growth rate determination is applicable in different oceanic regions under broadly varying environmental conditions. Chapter Three consists of the manuscript DISTRIBUTIONS OF CHLOROPHYLL AND PRIMARY PRODUCTIVITY IN RELATION TO WATER COLUMN STRUCTURE IN THE EASTERN NORTH ATLANTIC OCEAN. Chapter Three has been formatted in accordance with specifications of the Journal of Global Biogeochemical Cycles. Chapter Three has been submitted under the co-authorship of G. Berberian for review by the Journal of Biogeochemical Cycles. In Chapter Three latitudinal variations in the megascale (103 km) distribution of biological properties were observed in relation to the water column structure between 60°N and 7°N in the Eastern Atlantic Ocean. High chI a concentrations in the northern latitudes were associated with a shoaling of the pycnocline. A secondary region of high chI a at 7°N was associated with a lens of low salinity Amazon River water. Productivity maxima were located south of Iceland, in the vicinity of the Azores Front, and at the Amazon River water feature. The research described in Chapters Two and Three was performed during the Eastern North Atlantic section of the 1988 National Oceanic and Atmospheric Administration (NOAA) Global Change Expedition. Two appendices are included in the dissertation which contain pertinent Global Change Expedition data used in the manuscripts. Appendix One contains data relevant to Chapter Two, while Appendix Two contains data relevant to Chapter Three. A NOAA Data Report (Frazel, Berberian and Hitchcock 1989) containing complete data for the Global Change Cruise is also available. Reference lists are included at the end of Chapters Two and Three, while a master reference list is given at the end of the dissertation. Chapter Three has been formatted in accordance with specifications of the Journal of Global Biogeochemical Cycles. Chapter Three has been submitted under the co-authorship of G. Berberian for review by the Journal of Biogeochemical Cycles. In Chapter Three latitudinal variations in the macroscale (103 km) distribution of biological properties were observed in relation to the water column structure between 60°N and 7°N in the Eastern Atlantic Ocean. High chl a concentrations in the northern latitudes were associated with a shoaling of the pycnocline. A secondary region of high chI a at 7°N was associated with a lens of low salinity Amazon River water. Productivity maxima were located south of Iceland, in the vicinity of the Azores Front, and at the Amazon River water feature. The research described in Chapters Two and Three was performed during the Eastern North Atlantic section of the 1988 National Oceanic and Atmospheric Administration (NOAA) Global Change Expedition. Two appendices are included in the dissertation which contain pertinent Global Change Expedition data used in the manuscripts. Appendix One contains data relevant to Chapter Two, while Appendix Two contains data relevant to Chapter Three. A NOAA Data Report (Frazel, Berberian and Hitchcock 1989) containing complete data for the Global Change Cruise is also available. Reference lists are included at the end of Chapters Two and Three, while a Master Reference List is given at the end of the dissertation

Sensitivity analysis and parameter estimation for distributed hydrological modeling: potential of variational methods

Variational methods are widely used for the analysis and control of computationally intensive spatially distributed systems. In particular, the adjoint state method enables a very efficient calculation of the derivatives of an objective function (response function to be analysed or cost function to be optimised) with respect to model inputs. In this contribution, it is shown that the potential of variational methods for distributed catchment scale hydrology should be considered. A distributed flash flood model, coupling kinematic wave overland flow and Green Ampt infiltration, is applied to a small catchment of the Thoré basin and used as a relatively simple (synthetic observations) but didactic application case. It is shown that forward and adjoint sensitivity analysis provide a local but extensive insight on the relation between the assigned model parameters and the simulated hydrological response. Spatially distributed parameter sensitivities can be obtained for a very modest calculation effort (~6 times the computing time of a single model run) and the singular value decomposition (SVD) of the Jacobian matrix provides an interesting perspective for the analysis of the rainfall-runoff relation. For the estimation of model parameters, adjoint-based derivatives were found exceedingly efficient in driving a bound-constrained quasi-Newton algorithm. The reference parameter set is retrieved independently from the optimization initial condition when the very common dimension reduction strategy (i.e. scalar multipliers) is adopted. Furthermore, the sensitivity analysis results suggest that most of the variability in this high-dimensional parameter space can be captured with a few orthogonal directions. A parametrization based on the SVD leading singular vectors was found very promising but should be combined with another regularization strategy in order to prevent overfitting

Characterization of process-oriented hydrologic model behavior with temporal sensitivity analysis for flash floods in Mediterranean catchments

This paper presents a detailed analysis of 10 flash flood events in the Mediterranean region using the distributed hydrological model MARINE. Characterizing catchment response during flash flood events may provide new and valuable insight into the dynamics involved for extreme catchment response and their dependency on physiographic properties and flood severity. The main objective of this study is to analyze flash-flood-dedicated hydrologic model sensitivity with a new approach in hydrology, allowing model outputs variance decomposition for temporal patterns of parameter sensitivity analysis. Such approaches enable ranking of uncertainty sources for nonlinear and nonmonotonic mappings with a low computational cost. Hydrologic model and sensitivity analysis are used as learning tools on a large flash flood dataset. With Nash performances above 0.73 on average for this extended set of 10 validation events, the five sensitive parameters of MARINE process-oriented distributed model are analyzed. This contribution shows that soil depth explains more than 80% of model output variance when most hydrographs are peaking. Moreover, the lateral subsurface transfer is responsible for 80% of model variance for some catchment-flood events’ hydrographs during slow-declining limbs. The unexplained variance of model output representing interactions between parameters reveals to be very low during modeled flood peaks and informs that model parsimonious parameterization is appropriate to tackle the problem of flash floods. Interactions observed after model initialization or rainfall intensity peaks incite to improve water partition representation between flow components and initialization itself. This paper gives a practical framework for application of this method to other models, landscapes and climatic conditions, potentially helping to improve processes understanding and representation

Radiation Transport Modeling Using Parallel Computational Techniques

The second year of this project involved modeling several aspects of the LANCSE beam experiments: Modeling targets of varying diameter in air, in a vacuum, and in the presence of humid air; Modeling various proton beam profiles; Modeling the effects of off-axis proton beam impingement on the target; Modeling the asymmetry introduced by the steel table below the target; Modeling the effect of varying ratios of Pb to Bi and the effect of impurities; and Modeling the system, including other structures within the test room. With the experience gained through modeling these systems, the UNLV researchers plan, with the assistance of their national laboratory collaborators, to develop a benchmark program for the neutron leakage tests and other tests related to transmuter development. A comprehensive three-dimensional computer-aided design (CAD) image of the LANSCE experiments was prepared using ProEngineer to help benchmark the experiments and provide accurate geometric data for MCNPX modeling

Nuclear Criticality, Shielding, and Thermal Analyses of Separations Processes for the Transmutation Fuel Cycle

The first step in any transmutation strategy is the separation of radionuclides in used nuclear fuel. The current separation strategy supporting the Advanced Fuel Cycle Initiative (AFCI) program is based on the use of a solvent extraction separation process to separate the actinides, fission products, and uranium from used commercial nuclear fuel, and on the use of pyrochemical separation technologies to process used transmuter fuels. To separate the fission products and transuranic elements from the uranium in used fuel, the national program is developing a new solvent extraction process, the Uranium Extraction Plus, or UREX+, process based on the traditional solvent extraction reprocessing technologies. Preparing fuel for possible burn up in light water reactors, fast reactors, or accelerator-driven systems involves various chemical processes to partition the transuranics (neptunium, americium, plutonium, and curium) from the fission products. This results in waste streams that are highly radioactive and require radiation shielding for safety. These transuranic elements pose varied criticality, thermal, and radiation risks during storage and handling. Additionally, the radioactive decay of strontium and cesium waste products of the UREX+ technique produce roughly half of the thermal products and gamma radiation emissions in spent fuel. These radioisotopes require storage for approximately 300 years before heat and radiation hazards decrease to a safe level. As the volume of waste requiring treatment increases, a higher probability exists that fissionable isotopes of plutonium, neptunium, and curium can accumulate and form a critical mass. Criticality concerns warrant an assessment of the effective neutron multiplication factor, or keff, to prevent a possible sustained fission reaction. Maintaining keff below a safe level (\u3c0.95) prevents criticality events. This parameter can be computed for any combination of fuel and geometry using Monte Carlo neutron transport codes. Monte Carlo simulations establish the best means of examining the criticality safety of the proposed separation processes, and allow engineers to develop proper safety measures for the reprocessing and fabrication of actinide fuels. Candidate storage containers also require analysis to assess the need for radiation shielding. Since minor actinides generate significant amounts of heat through radioactive decay, proposed containment measures must be designed to avoid excessive temperatures. Radioactive decay also generates heat that can lead to melting of the fuel during storage and handling