513 research outputs found
A History of the Pokomo by Mikael Samson (Continued) with an introduction and notes
Volume: XVI
DETERMINANTS OF THE MAIZE BOARD-MILLER MARKETING MARGIN IN SOUTH AFRICA : 1977-1993
Determinants of the Maize Board - Miller (MBM) marketing margin for the period 1977-1993 (period defined by data limitations) are identified for a mark-up model using Three-Stage Least Squares Regression (3SLS) and Principal Component Analysis. The MBM margin was positively related to the real miller white maize meal selling price, real variable processing costs, and a change in Maize Board pricing policy after 1987
Commercial golf glove effects on golf performance and forearm muscle activity
The study aimed to determine whether or not commercial golf gloves influence performance variables and forearm muscle activity during golf play. Fifteen golfers participated in the laboratory based study, each performing 8 golf swings with a Driver and 7-iron whilst wearing a glove and 8 without wearing the glove. Club head speed, ball speed and absolute carry distance performance variables were calculated. Surface electromyography was recorded from the flexor digitorum superficialis and extensor carpi radialis brevis on both forearm muscles. Club head speed, ball speed and absolute carry distance was significantly higher when using the Driver with the glove in comparison to the Driver without the glove (p < 0.05). No significant differences were evident when using the 7-iron and no significant differences were displayed in muscle activity in either of the conditions. Findings from this study suggest that driving performance is improved when wearing a glove
Factors influencing adoption and intensity of adoption of orange flesh sweet potato varieties: Evidence from an extension intervention in Nyanza and Western provinces, Kenya.
The Effect of Substituting High Oil Corn as a Replacement for Normal Corn in Nursery Pig Diets
The objective of this study was to determine the production and monetary effects of using High Oil Corn (HOC) in a nursery phase feeding program and monitor growth performance differences through marketing. Two groups of weaned crossbred pigs (n = 293 trial 1; n = 265 trial 2) were segregated by sex and weight into small, medium and heavy groups and allotted to 12 nursery pens. Pigs received one of two dietary treatments which included; a transitional phase I diet for 7 days; a commercial corn soy based phase II diet (NCII) for 14 days and a phase III diet (NCIII) for 7 days; a HOC soy based phase II diet for 21 days and the NCIII diet for 7 days. Body weight, Average daily feed intake and Gain/Feed (G/F) ratios were measured weekly during the nursery period. Pigs were transferred to a grow/finish barn on d 28 post-weaning. Body weight, Backfat (BF) and Longissimus Muscle Area (LMA) at the 10th and last ribs were ultrasonically evaluated 4 times prior to market. Average daily gain of nursery pigs on the three-phase NC diet was greater than pigs fed the HOC two-phase diet at d 21 post-weaning (p = .0034) and 28 post-weaning (p = .0128). ADG for heavy pigs was greater (p = .0001) than that of medium and lightweight pigs and no treatment�weight group interactions were observed (p = .2043). Pigs fed the three-phase diet had greater G/F ratios than pigs fed the HOC two-phase diet at d 21 (p = .0137) and 28 (p = .0134). LEA for pigs fed the three-phase diet was greater than pigs fed the HOC two-phase diet when measured on d 28 at the 10th (p = .0565) and last rib (p = .0370). Even though pigs were fed alike in the grow-finish period, ADG of pigs fed the three-phase nursery diet was greater (p = .0106) than that of pigs fed the HOC two-phase nursery diet. There were no differences in the predicted 114 kg weight (p = .2658). However, economic differences were noted for the two treatments with the HOC two-phase diet lowering the cost of production of marketed animals. There were no treatment differences for average daily lean growth per day (p = .8611) or percentage lean of carcasses (p = .2865). The results did not support removal of the transitional phase I diet and the substitution of HOC for NC in a phase II diet fed to nursery pigs for maximal nursery growth, nor was carcass composition of pigs at marketing adversely affected
Palliative treatment of malignant esophageal-cardiac stricture in the ederly
The aging of the population and longer life expectancy
entails an increased number of elderly patients with esophageal
cancer and benign pathologies referred for surgical
treatment. Esophageal cancer is a pathology that
mainly involves elderly patients. The aim of this study is
to assess the effects of age on the outcome of surgery
for esophageal cancer and benign pathologies in patients
treated in our department
Answering two biological questions with a latent class model via MCMC applied to capture-recapture data.
Pre-anthesis ovary development determines genotypic differences in potential kernel weight in sorghum
Kernel weight is an important factor determining grain yield and nutritional quality in sorghum, yet the developmental processes underlying the genotypic differences in potential kernel weight remain unclear. The aim of this study was to determine the stage in development at which genetic effects on potential kernel weight were realized, and to investigate the developmental mechanisms by which potential kernel weight is controlled in sorghum. Kernel development was studied in two field experiments with five genotypes known to differ in kernel weight at maturity. Pre-fertilization floret and ovary development was examined and post-fertilization kernel-filling characteristics were analysed. Large kernels had a higher rate of kernel filling and contained more endosperm cells and starch granules than normal-sized kernels. Genotypic differences in kernel development appeared before stamen primordia initiation in the developing florets, with sessile spikelets of large-seeded genotypes having larger floret apical meristems than normal-seeded genotypes. At anthesis, the ovaries for large-sized kernels were larger in volume, with more cells per layer and more vascular bundles in the ovary wall. Across experiments and genotypes, there was a significant positive correlation between kernel dry weight at maturity and ovary volume at anthesis. Genotypic effects on meristem size, ovary volume, and kernel weight were all consistent with additive genetic control, suggesting that they were causally related. The pre-fertilization genetic control of kernel weight probably operated through the developing pericarp, which is derived from the ovary wall and potentially constrains kernel expansion
Pre-anthesis ovary development determines genotypic differences in potential kernel weight in sorghum
Kernel weight is an important factor determining grain yield and nutritional quality in sorghum, yet the developmental processes underlying the genotypic differences in potential kernel weight remain unclear. The aim of this study was to determine the stage in development at which genetic effects on potential kernel weight were realized, and to investigate the developmental mechanisms by which potential kernel weight is controlled in sorghum. Kernel development was studied in two field experiments with five genotypes known to differ in kernel weight at maturity. Pre-fertilization floret and ovary development was examined and post-fertilization kernel-filling characteristics were analysed. Large kernels had a higher rate of kernel filling and contained more endosperm cells and starch granules than normal-sized kernels. Genotypic differences in kernel development appeared before stamen primordia initiation in the developing florets, with sessile spikelets of large-seeded genotypes having larger floret apical meristems than normal-seeded genotypes. At anthesis, the ovaries for large-sized kernels were larger in volume, with more cells per layer and more vascular bundles in the ovary wall. Across experiments and genotypes, there was a significant positive correlation between kernel dry weight at maturity and ovary volume at anthesis. Genotypic effects on meristem size, ovary volume, and kernel weight were all consistent with additive genetic control, suggesting that they were causally related. The pre-fertilization genetic control of kernel weight probably operated through the developing pericarp, which is derived from the ovary wall and potentially constrains kernel expansion
Weak pairwise correlations imply strongly correlated network states in a neural population
Biological networks have so many possible states that exhaustive sampling is
impossible. Successful analysis thus depends on simplifying hypotheses, but
experiments on many systems hint that complicated, higher order interactions
among large groups of elements play an important role. In the vertebrate
retina, we show that weak correlations between pairs of neurons coexist with
strongly collective behavior in the responses of ten or more neurons.
Surprisingly, we find that this collective behavior is described quantitatively
by models that capture the observed pairwise correlations but assume no higher
order interactions. These maximum entropy models are equivalent to Ising
models, and predict that larger networks are completely dominated by
correlation effects. This suggests that the neural code has associative or
error-correcting properties, and we provide preliminary evidence for such
behavior. As a first test for the generality of these ideas, we show that
similar results are obtained from networks of cultured cortical neurons.Comment: Full account of work presented at the conference on Computational and
Systems Neuroscience (COSYNE), 17-20 March 2005, in Salt Lake City, Utah
(http://cosyne.org
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