110 research outputs found
Farm Modelling for Interactive Multidisciplinary Planning of Small Grain Production Systems in the Western Cape, South Africa
Subject matter research has made many contributions to small grain production in the Western Cape province of South Africa, but much of this focuses on single commodities and is undertaken within conventional disciplinary boundaries (e.g. soil science, genetics, economics). The result is that the solutions offered often have knock-on effects that are not properly accounted for by researchers. Expert group discussions, as a research method, are suitable, firstly, for gathering information in a meaningful manner and, secondly, to stimulate individual creativity by presenting alternative perspectives provided by various participating experts. In support of expert group discussions, multi-period wholefarm simulation models were developed. This type of modelling supports the accurate financial simulation of farms, while the user-friendliness and adaptability thereof can accurately accommodate typical farm interrelationships, and quickly measure the financial impact of suggested changes to parameters. Suggestions made by experts during the group discussions can thus be quickly introduced into the model. The financial implications are instantly available to prevent further exploration of nonviable plans and to fine-tune the viable plans. In this study, for each relatively homogeneous production area of the Western Cape, a typical farm budget model was developed, which served as the basis for the group discussions. The budget models measure profitability in terms of IRR (internal rate of return on capital investment) and affordability in terms of expected cash flow. The homogeneous areas identified were Koeberg/Wellington, the Middle Swartland and the Rooi Karoo, the Goue Rûens, Middle Rûens and Heidelberg Vlakte. For each area, the expected impact of climate change, fluctuating product and input prices, and the possible impact of partial conversion to bio-fuel production were evaluated in terms of expected impact on profitability. Various area-specific strategies were identified that could enhance the profitability of grain production: most of the strategies focused on optimising machinery usage and expanding or intensifying the livestock enterprise.whole-farm modelling, expert group discussions, Farm Management,
Farm Modelling for Interactive Multidisciplinary Planning of Small Grain Production Systems in the Western Cape, South Africa
Subject matter research has made many contributions to small grain production in the Western Cape
province of South Africa, but much of this focuses on single commodities and is undertaken within
conventional disciplinary boundaries (e.g. soil science, genetics, economics). The result is that the
solutions offered often have knock-on effects that are not properly accounted for by researchers.
Expert group discussions, as a research method, are suitable, firstly, for gathering information in a
meaningful manner and, secondly, to stimulate individual creativity by presenting alternative perspectives
provided by various participating experts. In support of expert group discussions, multi-period wholefarm
simulation models were developed. This type of modelling supports the accurate financial
simulation of farms, while the user-friendliness and adaptability thereof can accurately accommodate
typical farm interrelationships, and quickly measure the financial impact of suggested changes to
parameters. Suggestions made by experts during the group discussions can thus be quickly introduced
into the model. The financial implications are instantly available to prevent further exploration of nonviable
plans and to fine-tune the viable plans.
In this study, for each relatively homogeneous production area of the Western Cape, a typical farm budget
model was developed, which served as the basis for the group discussions. The budget models measure
profitability in terms of IRR (internal rate of return on capital investment) and affordability in terms of
expected cash flow. The homogeneous areas identified were Koeberg/Wellington, the Middle Swartland
and the Rooi Karoo, the Goue Rûens, Middle Rûens and Heidelberg Vlakte. For each area, the expected
impact of climate change, fluctuating product and input prices, and the possible impact of partial
conversion to bio-fuel production were evaluated in terms of expected impact on profitability. Various
area-specific strategies were identified that could enhance the profitability of grain production: most of
the strategies focused on optimising machinery usage and expanding or intensifying the livestock
enterprise
The effects of production system and sex on the sensory quality characteristics of dorperb lamb
The effect of production systems on the sensory quality characteristics of Dorper lambs was
investigated. Sixty lambs (ewes, rams, castrates) were allocated into two production groups (feedlot
or free-range) at weaning with equal numbers of each sex represented in each group. The lambs
were fed for five (slaughter group 1) or six (slaughter group 2) weeks. Feedlot lambs were fed a
commercial pelleted diet while free-range lambs utilized natural shrub pastures. Samples of the
Longissimus thoracis muscle were used for sensory evaluation. Feedlot lambs produced meat that was
juicier and more tender than meat from free-range lambs
Puddle formation, persistent gaps, and non-mean-field breakdown of superconductivity in overdoped (Pb,Bi)2Sr2CuO6+{\delta}
The cuprate high-temperature superconductors exhibit many unexplained
electronic phases, but it was often thought that the superconductivity at
sufficiently high doping is governed by conventional mean-field
Bardeen-Cooper-Schrieffer (BCS) theory[1]. However, recent measurements show
that the number of paired electrons (the superfluid density) vanishes when the
transition temperature Tc goes to zero[2], in contradiction to expectation from
BCS theory. The origin of this anomalous vanishing is unknown. Our scanning
tunneling spectroscopy measurements in the overdoped regime of the
(Pb,Bi)2Sr2CuO6+{\delta} high-temperature superconductor show that it is due to
the emergence of puddled superconductivity, featuring nanoscale superconducting
islands in a metallic matrix[3,4]. Our measurements further reveal that this
puddling is driven by gap filling, while the gap itself persists beyond the
breakdown of superconductivity. The important implication is that it is not a
diminishing pairing interaction that causes the breakdown of superconductivity.
Unexpectedly, the measured gap-to-filling correlation also reveals that
pair-breaking by disorder does not play a dominant role and that the mechanism
of superconductivity in overdoped cuprate superconductors is qualitatively
different from conventional mean-field theory
Clinopyroxene megacrysts from Marion Island, Antarctic Ocean: evidence for a late stage shallow origin
Clinopyroxene megacrysts (up to 5 cm) from a scoria cone on Marion Island, Antarctic Ocean are zoned, with compositionally distinct low (Al + Ti) and high (Al + Ti) patches arranged haphazardly throughout crystals. Inclusions of olivine, pyrrhotite, oxides, sulphides, and rounded inclusions with euhedral micro-crystals interpreted as former melt inclusions are observed. Olivine inclusions have variable compositions, ranging from primary Ti-poor crystals to Ti-rich crystals hosting secondary haematite crystals formed by hydrogenation. The crystals contain voids that are concentrated in the middle of each crystal indicating that the initial crystal growth was skeletal. Subsequent crystallisation filled in the skeletal framework creating the patchy zoning in the crystals. The Marion Island megacrysts are not homogenous, but the combination of crustal clinopyroxene compositions, primary and hydrogenated olivine, and the mode of eruption in scoria eruptions indicates that these crystals most likely formed in a shallow magma chamber. Primary olivines crystallised from a mafic magma and secondary altered olivines were incorporated into a rapidly growing megacryst in a super-saturated, fluid-rich environment, prior to being ejected onto surface in a scoria eruption.http://link.springer.com/journal/710hj2020Geolog
Different paths to the modern state in Europe: the interaction between domestic political economy and interstate competition
Theoretical work on state formation and capacity has focused mostly on early modern Europe and on the experience of western European states during this period. While a number of European states monopolized domestic tax collection and achieved gains in state capacity during the early modern era, for others revenues stagnated or even declined, and these variations motivated alternative hypotheses for determinants of fiscal and state capacity. In this study we test the basic hypotheses in the existing literature making use of the large date set we have compiled for all of the leading states across the continent. We find strong empirical support for two prevailing threads in the literature, arguing respectively that interstate wars and changes in economic structure towards an urbanized economy had positive fiscal impact. Regarding the main point of contention in the theoretical literature, whether it was representative or authoritarian political regimes that facilitated the gains in fiscal capacity, we do not find conclusive evidence that one performed better than the other. Instead, the empirical evidence we have gathered lends supports to the hypothesis that when under pressure of war, the fiscal performance of representative regimes was better in the more urbanized-commercial economies and the fiscal performance of authoritarian regimes was better in rural-agrarian economie
Neonatal factors predictive for respiratory and gastro-intestinal morbidity after esophageal atresia repair
Background: Esophageal atresia is a major congenital foregut anomaly. Affected patients often
suffer from respiratory and gastro-intestinal morbidity. The objective of this study is to identify possible neonatal predictive factors contributing to a long-term complicated clinical
course in patients after repair of esophageal atresia.
Methods: A total of 93 patients born between 1993 and 2013, with esophageal atresia and surviving the neonatal period were included in this retrospective study. A complicated clinical
course was defined as the occurrence of 1 of these complications: severe gastroesophageal reflux, esophageal stricture requiring dilatations, need for tube feeding for >100
days, severe tracheomalacia, severe chronic respiratory disease and death. We used linear
models with a binomial distribution to determine risk factors for gastro-intestinal or respiratory complicated evolution and a backward stepwise elimination procedure to reduce models until only significant variables remained in the model. Multinomial logistic regression was used
to assess risk factors for different evolutions of complication. Model parameter estimates were
used to calculate odds ratios for significant risk factors.
Results: Fifty-seven patients (61%) had a complicated clinical course in the first year of life and
47 (51%) had a complicated evolution during years 1e6. In the first year, prematurity was a significant factor for complicated gastro-intestinal (OR 2.84) and respiratory evolution (OR 2.93).
After 1 year, gastro-intestinal morbidity in childhood was associated with VACTERL association
(OR 12.2) and a complicated first year (OR 36.1). Respiratory morbidity was associated with
congenital heart disease (OR 12.9) and a complicated first year (OR 86.9). Multinomial logistic
regression showed that premat
Biosensor immunoassay for traces of hazelnut protein in olive oil
The fraudulent addition of hazelnut oil to more expensive olive oil not only causes economical loss but may also result in problems for allergic individuals as they may inadvertently be exposed to potentially allergenic hazelnut proteins. To improve consumer safety, a rapid and sensitive direct biosensor immunoassay, based on a highly specific monoclonal antibody, was developed to detect the presence of hazelnut proteins in olive oils. The sample preparation was easy (extraction with buffer); the assay time was fast (4.5 min only) and the limit of detection was low (0.08 μg/g of hazelnut proteins in olive oil). Recoveries obtained with an olive oil mixed with different amounts of a hazelnut protein containing hazelnut oil varied between 93% and 109%
The Astropy Problem
The Astropy Project (http://astropy.org) is, in its own words, "a community
effort to develop a single core package for Astronomy in Python and foster
interoperability between Python astronomy packages." For five years this
project has been managed, written, and operated as a grassroots,
self-organized, almost entirely volunteer effort while the software is used by
the majority of the astronomical community. Despite this, the project has
always been and remains to this day effectively unfunded. Further, contributors
receive little or no formal recognition for creating and supporting what is now
critical software. This paper explores the problem in detail, outlines possible
solutions to correct this, and presents a few suggestions on how to address the
sustainability of general purpose astronomical software
Hundreds of variants clustered in genomic loci and biological pathways affect human height
Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P < 0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.
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