5,021 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,
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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
Diurnal pattern of QTc interval: How long is prolonged? Possible relation to circadian triggers of cardiovascular events
Objectives.This study sought to evaluate the range and variability of the QT and corrected QT (QTc) intervals over 24 h and to assess their pattern and relation to heart rate variability.Background.Recent Holter monitoring data have revealed a high degree of daily variability in the QTc interval. The pattern of this variability and its relation to heart rate variability remain poorly characterized.Methods.We developed and validated a new method for continuous measurement of QT intervals from three-channel, 24-h Holter recordings. Average RR, QT, QTc and heart rate variability were measured from 5-min segments of data from 21 healthy subjects.Results.Measurement of 6,048 segments showed mean (±SD) RR, QT and QTc intervals of 830 ± 100, 407 ± 23 and 445 ± 16 ms, respectively (mean QTc interval for men 434 ± 12 ms, 457 ± 10 ms for women, p < 0.0001). The average maximal QTc interval was 495 ± 21 ms and the average QTc range 95 ± 20 ms. The maximal QTc interval was ≥500 ms in 6 subjects and ≥490 ms in 13. The 95% upper confidence limit for the mean 24-h QTc interval was 452 ms (men 439 ms, women 461 ms). The RR, QT and QTc intervals and the high frequency component of heart rate variability were greater during sleep. Both the QTc interval and the variability between hourly minimal and maximal QTc intervals reached their circadian peak shortly after awakening, before declining to daytime levels.Conclusions.The maximal QTc interval over 24 h in normal subjects is longer than heretofore thought. Both QT and QTc intervals are longer during sleep. The QTc interval and QTc variability reach a peak shortly after awakening, which may reflect increased autonomic instability during early waking hours, and the time of the peak value corresponds in time to the period of reported increased vulnerability to ventricular tachycardia and sudden cardiac death. These findings have implications regarding the definition of QT prolongation and its use in predicting arrhythmias and sudden death
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A Comparative Study of the ReCell® Device and Autologous Spit-Thickness Meshed Skin Graft in the Treatment of Acute Burn Injuries.
Early excision and autografting are standard care for deeper burns. However, donor sites are a source of significant morbidity. To address this, the ReCell® Autologous Cell Harvesting Device (ReCell) was designed for use at the point-of-care to prepare a noncultured, autologous skin cell suspension (ASCS) capable of epidermal regeneration using minimal donor skin. A prospective study was conducted to evaluate the clinical performance of ReCell vs meshed split-thickness skin grafts (STSG, Control) for the treatment of deep partial-thickness burns. Effectiveness measures were assessed to 1 year for both ASCS and Control treatment sites and donor sites, including the incidence of healing, scarring, and pain. At 4 weeks, 98% of the ASCS-treated sites were healed compared with 100% of the Controls. Pain and assessments of scarring at the treatment sites were reported to be similar between groups. Significant differences were observed between ReCell and Control donor sites. The mean ReCell donor area was approximately 40 times smaller than that of the Control (P < .0001), and after 1 week, significantly more ReCell donor sites were healed than Controls (P = .04). Over the first 16 weeks, patients reported significantly less pain at the ReCell donor sites compared with Controls (P ≤ .05 at each time point). Long-term patients reported higher satisfaction with ReCell donor site outcomes compared with the Controls. This study provides evidence that the treatment of deep partial-thickness burns with ASCS results in comparable healing, with significantly reduced donor site size and pain and improved appearance relative to STSG
Genome-scale hypomethylation in the cord blood DNAs associated with early onset preeclampsia
Background: Preeclampsia is one of the leading causes of fetal and maternal morbidity and mortality worldwide.
Preterm babies of mothers with early onset preeclampsia (EOPE) are at higher risks for various diseases later on in life,
including cardiovascular diseases. We hypothesized that genome-wide epigenetic alterations occur in cord blood DNAs
in association with EOPE and conducted a case control study to compare the genome-scale methylome differences in
cord blood DNAs between 12 EOPE-associated and 8 normal births.
Results: Bioinformatics analysis of methylation data from the Infinium HumanMethylation450 BeadChip shows a
genome-scale hypomethylation pattern in EOPE, with 51,486 hypomethylated CpG sites and 12,563 hypermethylated sites
(adjusted P <0.05). A similar trend also exists in the proximal promoters (TSS200) associated with protein-coding genes.
Using summary statistics on the CpG sites in TSS200 regions, promoters of 643 and 389 genes are hypomethylated and
hypermethylated, respectively. Promoter-based differential methylation (DM) analysis reveals that genes in the farnesoid X
receptor and liver X receptor (FXR/LXR) pathway are enriched, indicating dysfunction of lipid metabolism in cord blood
cells. Additional biological functional alterations involve inflammation, cell growth, and hematological system
development. A two-way ANOVA analysis among coupled cord blood and amniotic membrane samples shows
that a group of genes involved in inflammation, lipid metabolism, and proliferation are persistently differentially
methylated in both tissues, including IL12B, FAS, PIK31, and IGF1.
Conclusions: These findings provide, for the first time, evidence of prominent genome-scale DNA methylation
modifications in cord blood DNAs associated with EOPE. They may suggest a connection between inflammation and
lipid dysregulation in EOPE-associated newborns and a higher risk of cardiovascular diseases later in adulthood
A New Target for Amyloid Beta Toxicity Validated by Standard and High-Throughput Electrophysiology
Soluble oligomers of amyloid beta (Abeta) are considered to be one of the major contributing factors to the development of Alzheimer's disease. Most therapeutic development studies have focused on toxicity directly at the synapse.Patch clamp studies detailed here have demonstrated that soluble Abeta can also cause functional toxicity, namely it inhibits spontaneous firing of hippocampal neurons without significant cell death at low concentrations. This toxicity will eventually lead to the loss of the synapse as well, but may precede this loss by a considerable amount of time. In a key technological advance we have reproduced these results utilizing a fast and simple method based on extracellular electrophysiological recording of the temporal electrical activity of cultured hippocampal neurons using multielectrode arrays (MEAs) at low concentrations of Abeta (1-42). We have also shown that this functional deficit can be reversed through use of curcumin, an inhibitor of Abeta oligomerization, using both analysis methods.The MEA recording method utilized here is non-invasive, thus long term chronic measurements are possible and it does not require precise positioning of electrodes, thus it is ideal for functional screens. Even more significantly, we believe we have now identified a new target for drug development for AD based on functional toxicity of hippocampal neurons that could treat neurodegenerative diseases prior to the development of mild cognitive impairment
Opacity effects and shock-in-jet modelling of low-level activity in Cygnus X-3
We present simultaneous dual-frequency radio observations of Cygnus X-3
during a phase of low-level activity. We constrain the minimum variability
timescale to be 20 minutes at 43 GHz and 30 minutes at 15 GHz, implying source
sizes of 2 to 4 AU. We detect polarized emission at a level of a few per cent
at 43 GHz which varies with the total intensity. The delay of approximately 10
minutes between the peaks of the flares at the two frequencies is seen to
decrease with time, and we find that synchrotron self-absorption and free-free
absorption by entrained thermal material play a larger role in determining the
opacity than absorption in the stellar wind of the companion. A shock-in-jet
model gives a good fit to the lightcurves at all frequencies, demonstrating
that this mechanism, which has previously been used to explain the brighter,
longer-lived giant outbursts in this source, is also applicable to these
low-level flaring events. Assembling the data from outbursts spanning over two
orders of magnitude in flux density shows evidence for a strong correlation
between the peak brightness of an event, and the timescale and frequency at
which this is attained. Brighter flares evolve on longer timescales and peak at
lower frequencies. Analysis of the fitted model parameters suggests that
brighter outbursts are due to shocks forming further downstream in the jet,
with an increased electron normalisation and magnetic field strength both
playing a role in setting the strength of the outburst.Comment: Accepted for publication in MNRAS. 15 pages, 9 figure
A Multi-wavelength Study of the Sunyaev-Zel'dovich Effect in the Triple-Merger Cluster MACS J0717.5+3745 with MUSTANG and Bolocam
We present 90, 140, and 268GHz sub-arcminute resolution imaging of the
Sunyaev-Zel'dovich effect (SZE) in MACSJ0717.5+3745. Our 90GHz SZE data result
in a sensitive, 34uJy/bm map at 13" resolution using MUSTANG. Our 140 and
268GHz SZE imaging, with resolutions of 58" and 31" and sensitivities of 1.8
and 3.3mJy/beam respectively, was obtained using Bolocam. We compare these maps
to a 2-dimensional pressure map derived from Chandra X-ray observations. Our
MUSTANG data confirm previous indications from Chandra of a pressure
enhancement due to shock-heated, >20keV gas immediately adjacent to extended
radio emission seen in low-frequency radio maps. The MUSTANG data also detect
pressure substructure that is not well-constrained by the X-ray data in the
remnant core of a merging subcluster. We find that the small-scale pressure
enhancements in the MUSTANG data amount to ~2% of the total pressure measured
in the 140GHz Bolocam observations. The X-ray template also fails on larger
scales to accurately describe the Bolocam data, particularly at the location of
a subcluster known to have a high line of sight optical velocity (~3200km/s).
Our Bolocam data are adequately described when we add an additional component -
not described by a thermal SZE spectrum - coincident with this subcluster.
Using flux densities extracted from our model fits, and marginalizing over the
temperature constraints for the region, we fit a thermal+kinetic SZE spectrum
to our data and find the subcluster has a best-fit line of sight proper
velocity of 3600+3440/-2160km/s. This agrees with the optical velocity
estimates for the subcluster. The probability of velocity<0 given our
measurements is 2.1%. Repeating this analysis using flux densities measured
non-parametrically results in a 3.4% probability of a velocity<=0. We note that
this tantalizing result for the kinetic SZE is on resolved, subcluster scales.Comment: 10 Figures, 18 pages. this version corrects issues with the previous
arXiv versio
Middle to Late Miocene Contractional Deformation in Costa Rica Triggered by Plate Geodynamics
Contractional deformation in Costa Rica is usually attributed to the subduction of the aseismic Cocos Ridge. In this work, we review the evidences for contraction in the middle to late Miocene, prior to the arrival of the Cocos Ridge at the Middle America Trench. We find that the Miocene phase of contractional deformation is found in all of Costa Rica, probably extending to Nicaragua as well. The widespread distribution of this event requires a regional or plate geodynamic trigger. We analyze the possible mechanisms that could produce the onset of contractional deformation, using the better known case of subduction orogeny, the Andes, as an analog. We propose that a change in the direction of the Cocos plate since ∼19 Ma led to a change from oblique to orthogonal convergence, producing contractional deformation of the upper plate.Fil: Mescua, Jose Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Porras, Hernan. Observatorio Vulcanológico y Sismológico de Costa Rica; Costa RicaFil: Duran, Patrick. Universidad de Costa Rica; Costa RicaFil: Giambiagi, Laura Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: de Moor, Maerten. Observatorio Vulcanológico y Sismológico de Costa Rica; Costa RicaFil: Cascante, Monserrat. Observatorio Vulcanológico y Sismológico de Costa Rica; Costa RicaFil: Salazar, Esteban. Servicio Nacional de Geología y Minería; ChileFil: Protti, Marino. Observatorio Vulcanológico y Sismológico de Costa Rica; Costa RicaFil: Poblete, Fernando. Universidad de O’Higgins; Chil
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