5,832 research outputs found
Simulation of Tail Weight Distributions in Biological Year 1986–2006 Landings of Brown Shrimp, Farfantepenaeus aztecus, from the Northern Gulf of Mexico Fishery
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
Enacting heavy sessional drinking: a multi-sited ethnographic study of young adults’ drinking events and related epidemiology, policy and treatment
Taking cues from science and technology studies, this thesis explores how problems associated with the heavy sessional drinking of young adults are currently enacted in significant sites of research, policy and service provision. It demonstrates that alcohol epidemiology, policy initiatives to change ‘drinking culture’, and the clinical science associated with alcohol and other drug treatment erase the effects of socioeconomic disadvantage. With reference to ethnographic data, it proposes a range of alternate formulations
Interpreting the Heightened Pleading of the Scienter Requirement in Private Securities Fraud Litigation: The Tenth Circuit Takes the Middle Ground
Children's conceptions of masculinity : The mask : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Media Studies at Massey University
Television's potential influence on its viewers is frequently the topic of heated debate, both in academia and wider society. This research uses media representations of masculinity embodied in the cartoon programme "The Mask" as a basis for the study of the social construction of masculinity. The research has two foci. Firstly, the observation of how children's talk about television, in particular, their understandings of masculinity, actively constructs subject position for them; and secondly, participant use of modality judgements. This thesis holds that modality judgements are a vehicle through which potentially conflicting information (in the form of internal and external modality markers) is actively synthesized. Particular attention is given to how the participants' understandings of masculinity are actively negotiated with the representations of masculinity as depicted by the cartoon. The influential work of Buckingham (1993), Morley (1980) and Hall (1980) provides the theoretical framework in which this thesis is structured. The overall results from the focus group research indicated that participants tended to use traditional understandings of the nature of masculinity to conceptualise how 'most men ought' to be. This research has potential implications for the ongoing societal debates regarding the censorship of children's viewing material
Piscataquis County Micro-Enterprise Survey
The study comprised the development and implementation of a survey of microenterprise owners in Piscataquis County. The survey was designed to collect information about home-based businesses and micro-enterprises in Piscataquis County to determine their characteristics, their economic impact, and to identify their business needs
The Mackenzie Inuit Winter House
The Inuit of the Mackenzie Delta area who called themselves "Siglit", built winter homes not out of snow, but of driftwood, and in villages which they occupied annually. This article discusses the earliest historical record of Siglit architecture and building techniques including ventilation and insulation
Topologically stable ergodicity breaking from emergent higher-form symmetries in generalized quantum loop models
We present a set of generalized quantum loop models which provably exhibit
topologically stable ergodicity breaking. These results hold for both periodic
and open boundary conditions, and derive from a one-form symmetry (notably not
being restricted to sectors of extremal one-form charge). We identify simple
models in which this one-form symmetry can be emergent, giving rise to the
aforementioned ergodicity breaking as an exponentially long-lived prethermal
phenomenon. We unveil a web of dualities that connects these models, in certain
limits, to models that have previously been discussed in the literature. We
also identify nonlocal conserved quantities in such models that correspond to a
pattern of system-spanning domain walls, and which are robust to the addition
of arbitrary -local perturbations.Comment: 22+8 pages, 8 figure
Geographical Information System Coverage For Characterization of the Pecos River Basin
To develop a successful watershed protection plan for the Pecos River, it is very important to
correctly characterize the river basin including vegetation coverage, river channel and others.
The objective of subtask 1.1 was to delineate the Pecos River and its various characterizations
using aerial photography. The aerial photography was high resolution and was acquired for the
main channel of the Pecos River. The aerial photos were also taken to help differentiate invasive
and non invasive vegetation (i.e. saltcedar and mesquite and other native species). Remote
sensing was used to identify the various characteristics of stream channel locations, saltcedar
overgrowth and treatment areas, and land use. GIS (Geographical Information Systems) was
used to develop a baseline assessment of the Pecos River Basin’s characteristics (Stream channel
morphology, riparian vegetation aerial photography, etc.). GIS will be the platform to create,
view, and utilize data that was created or downloaded via the internet for the study region of the
Pecos River Watershed. This report discusses procedures for data processing and mapping, and
presented images produced
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