8,060 research outputs found
Economics of Fish Marketing in Central Uganda: A Preliminary Analysis
The paper examines profitability and market performance of small-scale fish traders selected randomly from a cross-section of nine fish markets in four districts in Central Uganda. Data were collected through a structured questionnaire which was designed to solicit information on traders’ socio-economic characteristics, marketing characteristics, operating costs and returns, and problems associated with fish marketing in the study area. Percentages were used to describe the socio-economic characteristics, market characteristic and problems associated with fish marketing while gross profit and marketing performance models were used to determine profitability, marketing margin and operational efficiency, respectively. The results suggest that fish trade is carried out by both men and women. More men are involved in the trade of fresh fish while more women are involved in the processed (sundried/smoked) fish trade. Some traders dealt in more than one species of fish although a majority sold exclusively in one species. Gross profit was estimated at USh358.40/kg and USh234.73/kg for wholesalers and retailers, respectively, with marketing margins of 19.32% and 16.67% for wholesalers and retailers, respectively. The market operational efficiency was 279.27 percent, implying high efficiency in fish marketing in the study area. The major pressing concerns which included high supply cost, low prices, low fish supply and increased arrests for selling immature fish were common to both retail and wholesale marketing channels.Fish marketing, survey data, gross profit, market margin, operational efficiency, Uganda, Agribusiness, International Development, International Relations/Trade, Marketing, Research Methods/ Statistical Methods,
Consumer Purchasing Behaviors and Attitudes toward Shopping at Public Markets
This paper identifies and empirically evaluates factors that explain the variations in consumers’ attitudes toward shopping at farmers markets in general and public markets in particular. The analysis draws on data from a telephone survey conducted in Jefferson County, Alabama. Logit model results point to several factors that seem to be strongly correlated with consumer purchasing behaviors and attitudes toward shopping at public markets, including income, education, age of household head, household size, and price and quality of produce. The insights gained from the study should help farmers increase the profitability of their operations and improve the likelihood that they will continue farming.Consumer/Household Economics,
Development of relativistic shock waves in viscous gluon matter
To investigate the formation and the propagation of relativistic shock waves
in viscous gluon matter we solve the relativistic Riemann problem using a
microscopic parton cascade. We demonstrate the transition from ideal to viscous
shock waves by varying the shear viscosity to entropy density ratio .
We show that an ratio larger than 0.2 prevents the development of
well-defined shock waves on time scales typical for ultrarelativistic heavy-ion
collisions. These findings are confirmed by viscous hydrodynamic calculations.Comment: 4 pages, 3 figures - To appear in the conference proceedings for
Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse
Risk factors for unplanned and crash dialysis starts: a protocol for a systematic review and meta-analysis
BACKGROUND: Many patients with kidney failure “crash” onto dialysis or initiate dialysis in an unplanned fashion. There are varying definitions, but essentially, a patient is labeled as having a crash dialysis start if he or she has little to no care by a nephrologist prior to starting dialysis. A patient is labeled as having an unplanned dialysis start when he or she starts dialysis with a catheter or during a hospitalization. Given the high prevalence and poor outcomes associated with crash and unplanned dialysis starts, it is important to establish a better understanding of patient risk factors. METHODS: We will conduct a systematic review and meta-analysis with a focus on both crash and unplanned dialysis starts. The first objective will be to determine patient risk factors for crash and unplanned dialysis starts. Secondary objectives will be to determine the most common criteria used to define both crash and unplanned dialysis starts and to determine outcomes associated with crash and unplanned dialysis starts. We will search MEDLINE, EMBASE and Cochrane Library from inception to the present date for all studies that report the characteristics and outcomes of patients who have crash vs. non-crash dialysis starts or unplanned vs. planned dialysis starts. We will also extract from included studies the criteria used to define crash and unplanned dialysis starts. If there are any eligible randomized controlled trials, quality assessment will be performed using the Cochrane Risk of Bias Assessment Tool. Observational studies will be evaluated using the Newcastle-Ottawa Scale. Data will be pooled in meta-analysis if deemed appropriate. DISCUSSION: The results of this review will inform the design of strategies to help reduce the incidence of crash and unplanned dialysis starts. SYSTEMATIC REVIEW REGISTRATION: Prospero CRD42016032916 ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13643-016-0297-2) contains supplementary material, which is available to authorized users
Mach Cones in Viscous Matter
Employing a microscopic transport model we investigate the evolution of high
energetic jets moving through a viscous medium. For the scenario of an
unstoppable jet we observe a clearly strong collective behavior for a low
dissipative system , leading to the observation of
cone-like structures. Increasing the dissipation of the system to the Mach Cone structure vanishes. Furthermore, we investigate
jet-associated particle correlations. A double-peak structure, as observed in
experimental data, is even for low-dissipative systems not supported, because
of the large influence of the head shock.Comment: 4 pages, 3 figures, to appear in the conference proceedings of Hot
Quarks 201
A statistical model for isolated convective precipitation events
To study the diurnal evolution of the convective cloud field, we develop a
precipitation cell tracking algorithm which records the merging and
fragmentation of convective cells during their life cycles, and apply it on
large eddy simulation (LES) data. Conditioning on the area covered by each
cell, our algorithm is capable of analyzing an arbitrary number of auxiliary
fields, such as the anomalies of temperature and moisture, convective available
potential energy (CAPE) and convective inhibition (CIN). For tracks that do not
merge or split (termed "solitary"), many of these quantities show generic,
often nearly linear relations that hardly depend on the forcing conditions of
the simulations, such as surface temperature. This finding allows us to propose
a highly idealized model of rain events, where the surface precipitation area
is circular and a cell's precipitation intensity falls off linearly with the
distance from the respective cell center. The drop-off gradient is nearly
independent of track duration and cell size, which allows for a generic
description of such solitary tracks, with the only remaining parameter the peak
intensity. In contrast to the simple and robust behavior of solitary tracks,
tracks that result from merging of two or more cells show a much more
complicated behavior. The most intense, long lasting and largest tracks indeed
stem from multi-mergers - tracks involved in repeated merging. Another
interesting finding is that the precipitation intensity of tracks does not
strongly depend on the absolute amount of local initial CAPE, which is only
partially consumed by most rain events. Rather, our results speak to boundary
layer cooling, induced by rain re-evaporation, as the cause for CAPE reduction,
CIN increase and shutdown of precipitation cells.Comment: Manuscript under review in Journal of Advances in Modeling Earth
System
Which game narratives do adolescents of different gameplay and sociodemographic backgrounds prefer? a mixed-methods analysis
OBJECTIVE: The aim of this study was to investigate which narrative elements of digital game narratives are preferred by the general adolescent population, and to examine associations with gender, socioeconomic status (SES), and gameplay frequency. Further, the study aims to discuss how results can be translated to serious digital games.
MATERIALS AND METHODS: Adolescents were recruited through school to complete a survey on narrative preferences in digital games. The survey included questions on sociodemographic information, frequency of gameplay, and an open-ended question on what could be an appealing narrative for them. Data were analyzed in a mixed-methods approach, using thematic analysis and chi-square analyses to determine narrative preferences and the associations between game narrative elements and player characteristics (gender, SES, and frequency of gameplay).
RESULTS: The sample consisted of 446 adolescents (12-15 years old) who described 30 narrative subthemes. Preferences included human characters as protagonists; nonhuman characters only as antagonists; realistic settings, such as public places or cities; and a strong conflict surrounding crime, catastrophe, or war. Girls more often than boys defined characters by their age, included avatars, located the narrative in private places, developed profession-related skills, and included a positive atmosphere. Adolescents of nonacademic education more often than adolescents of academic education defined characters by criminal actions. Infrequent players more often included human characters defined by their age than frequent players. After performing a Bonferroni correction, narrative preferences for several gender differences remained.
CONCLUSION: Different narrative elements related to subgroups of adolescents by gender, SES, and frequency of gameplay. Customization of narratives in serious digital health games should be warranted for boys and girls; yet, further research is needed to specify how to address girls in particular
The Genome of the Chicken DT40 Bursal Lymphoma Cell Line
The chicken DT40 cell line is a widely used model system in the study of multiple cellular processes due to the efficiency of homologous gene targeting. The cell line was derived from a bursal lymphoma induced by avian leukosis virus infection. In this study we characterized the genome of the cell line using whole genome shotgun sequencing and single nucleotide polymorphism array hybridization. The results indicate that wild type DT40 has a relatively normal karyotype except for whole chromosome copy number gains, and no karyotype variability within stocks. In a comparison to two domestic chicken genomes and the Gallus gallus reference genome we found no unique mutational processes shaping the DT40 genome except for a mild increase in insertion and deletion events, particularly deletions at tandem repeats. We mapped coding sequence mutations that are unique to the DT40 genome; mutations inactivating the PIK3R1 and ATRX genes likely contributed to the oncogenic transformation. In addition to a known avian leukosis virus integration in the MYC gene we detected further integration sites that are likely to de-regulate gene expression. The new findings support the hypothesis that DT40 is a typical transformed cell line with a relatively intact genome, therefore it is well suited to the role of a model system for DNA repair and related processes. The sequence data generated by this study, including a searchable de novo genome assembly and annotated lists of mutated genes, will support future research using this cell line
Characterization of SU(1,1) coherent states in terms of affine group wavelets
The Perelomov coherent states of SU(1,1) are labeled by elements of the
quotient of SU(1,1) by the compact subgroup. Taking advantage of the fact that
this quotient is isomorphic to the affine group of the real line, we are able
to parameterize the coherent states by elements of that group or equivalently
by points in the half-plane. Such a formulation permits to find new properties
of the SU(1,1) coherent states and to relate them to affine wavelets.Comment: 11 pages, latex, to be published in J. Phys. A : Math. Ge
Anaphe - OO Libraries and Tools for Data Analysis
The Anaphe project is an ongoing effort to provide an Object Oriented software environment for data analysis in HENP experiments. A range of commercial and public domain libraries is used to cover basic functionalities; on top of these libraries a set of HENP-specific C++ class libraries for histogram management, fitting, plotting and ntuple-like data analysis has been developed. In order to comply with the user requirements for a command-line driven tool, we have chosen to use a scripting language (Python) as the front-end for a data analysis tool. The loose coupling provided by the consequent use of (AIDA compliant) Abstract Interfaces for each component in combination with the use of shared libraries for their implementation provides an easy integration of existing libraries into modern scripting languages thus allowing for rapid application development. This integration is simplified even further using a specialised toolkit (SWIG) to create "shadow classes" for the Python language, which map the definitions of the Abstract Interfaces almost at a one-to-one level. This paper will give an overview of the architecture and design choices and will present the current status and future developments of the project
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