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Globally, human house types are diverse, varying in shape, size, roof type, building materials, arrangement, decoration and many other features. Here we offer the first rigorous, global evaluation of the factors that influence the construction of traditional (vernacular) houses. We apply macroecological approaches to analyse data describing house features from 1900 to 1950 across 1000 societies. Geographic, social and linguistic descriptors for each society were used to test the extent to which key architectural features may be explained by the biophysical environment, social traits, house features of neighbouring societies or cultural history. We find strong evidence that some aspects of the climate shape house architecture, including floor height, wall material and roof shape. Other features, particularly ground plan, appear to also be influenced by social attributes of societies, such as whether a society is nomadic, polygynous or politically complex. Additional variation in all house features was predicted both by the practices of neighouring societies and by a society's language family. Collectively, the findings from our analyses suggest those conditions under which traditional houses offer solutions to architects seeking to reimagine houses in light of warmer, wetter or more variable climates.
Social inequality is ubiquitous in contemporary human societies, and has deleterious social and ecological impacts. However, the factors that shape the emergence and maintenance of inequality remain widely debated. Here we conduct a global analysis of pathways to inequality by comparing 408 non-industrial societies in the anthropological record (described largely between 1860 and 1960) that vary in degree of inequality. We apply structural equation modelling to open-access environmental and ethnographic data and explore two alternative models varying in the links among factors proposed by prior literature, including environmental conditions, resource intensification, wealth transmission, population size and a well-documented form of inequality: social class hierarchies. We found support for a model in which the probability of social class hierarchies is associated directly with increases in population size, the propensity to use intensive agriculture and domesticated large mammals, unigeniture inheritance of real property and hereditary political succession. We suggest that influence of environmental variables on inequality is mediated by measures of resource intensification, which, in turn, may influence inequality directly or indirectly via effects on wealth transmission variables. Overall, we conclude that in our analysis a complex network of effects are associated with social class hierarchies.
Human color perception is widely understood to be based on a neural coding system involving signals from three distinct classes of retinal photoreceptors. This retina processing model has long served as the mainstream scientific template for human color vision research and has also proven to be useful for the practical design of display technologies, user interfaces, and medical diagnosis tools that enlist human color perception behaviors. Recent findings in the area of retinal photopigment gene sequencing have provided important updates to our understanding of the molecular basis and genetic inheritance of individual variations of human color vision. This Element focuses on new knowledge about the linkages between color vision genetics and color perception variation and the color perception consequences of inheriting alternative, nonnormative, forms of genetic sequence variation.
The Virtual Environment for Radiotherapy Training (VERT) is a high-fidelity simulation hardware and software resource that replicates the expensive and high-pressure clinical environment of a radiotherapy treatment machine. The simulation allows students to gain confidence with clinical techniques in a safe and unpressured academic environment before clinical placement. The aim of this study was to establish the current and future role of VERT and explore the potential for collaborative resource development and research.
Methods
An anonymous online survey was made available to all users of the software internationally (n=52). A mixture of fixed and open response questions gathered usage data and user feedback.
Results
The study had a 90% response rate (n=47). Most participants (78·5%) used the resource 1 day/week or less; around 8,000 hours worldwide. It was clear that most participants used the simulation resource to help student to either gain understanding of concepts and techniques or to gain practice with techniques and practical skills. There was good support for collaborative resource development, deployment and evaluation to help VERT users to fully exploit its range of pedagogical uses.
Conclusions
This audit demonstrated high levels of engagement and enthusiasm for collaborative resource development and ongoing research among the radiotherapy simulation community. Adoption of an international Academic Community of Practice for collaborative simulation resource deployment and support may be of significant value and is worthy of further discussion and consideration.
The effect of annual defoliation on leafy spurge-infested rangeland was investigated over a 5-yr period. Artificial defoliation was conducted once or twice annually at various phenological growth stages of leafy spurge to simulate grazing by herded Angora goats. Single defoliation treatments did not reduce total leafy spurge stem densities. Defoliation twice in a growing season for 4 consecutive yr reduced total leafy spurge stem densities by 55% over nondefoliated controls. Grass foliar cover and yield increased in all defoliation treatments. Despite the increased grass yield on single defoliation treatments, cattle use would likely be limited in these treatments due to the high density of leafy spurge stems. Stem densities of leafy spurge in twice-defoliated treatments should not deter cattle from grazing these sites, thereby increasing the available forage supply. The data suggest that repeated grazing of leafy spurge-infested rangeland within a growing season would be required to reduce stem densities adequately and increase cattle use and production from these sites.
In this paper, we explore the interfacial effects appearing in highly strained La0.7Ca0.3MnO3 (LCMO) ultra-thin films (10-12nm) grown on BaTiO3 (BTO) ferroelectric substrates. The strong tendency to phase separation of this optimally doped manganite contributes to the exotic phenomena observed in magnetism and transport experiments: the so-called Matteucci magnetic loops, magnetic granularity and a second metal insulator transition are observed between 50K and the LCMO Curie temperature, 180K. All these properties define the multiferroic character of these heterostructures, which in LCMO//BTO system is strongly linked to magnetoelastic coupling.
High density single nucleotide polymorphism (SNP) genotyping panels provide an alternative to microsatellite markers for genome scans. However, genotype errors have a major impact on power to detect linkage or association and are difficult to detect for SNPs. We estimated error rates with the Affymetrix GeneChip® SNP platform in samples from a family with a mixed set of monozygotic (MZ) and dizygotic (DZ) triplets using lymphocyte, buccal DNA and samples from whole genome amplification using the multiple displacement amplification (MDA) technique. The average call rate from 58,960 SNPs for five genomic samples was 99.48%. Comparison of results for the MZ twins showed only three discordant genotypes (concordance rate 99.995%). The mean concordance rate for comparisons of samples from lymphocyte and buccal DNA was 99.97%. Mendelian inconsistencies were identified in 46 SNPs with errors in one or more family members, a rate of 0.022%. Observed genotype concordance rates between parents, between parents and children, and among siblings were consistent with previously reported allele frequencies and Hardy–Weinberg equilibrium. Using the MDA technique, results for two samples had equivalent high accuracy to results with genomic samples. However, the SNP call rate for the remaining seven samples varied from 72.5% to 99.5%, with an average of 86.11%. Quality of the DNA sample following the MDA reaction appears to be the critical factor in SNP call rate for MDA samples. Our results demonstrate highly accurate and reproducible genotyping for the Affymetrix GeneChip® Human Mapping Set in lymphocyte and buccal DNA samples.
Inherited disorders of mitochondrial oxidative phosphorylation are the most common group of inborn errors of metabolism and cause a wide range of clinical presentations. Mitochondrial DNA encodes 13 protein subunits required for oxidative phosphorylation plus 22 transfer RNAs and two ribosomal RNAs, and mutations in most of these genes cause human disease. Nuclear genes encode most of the protein subunits and all other proteins required for mitochondrial biogenesis and mitochondrial DNA replication and expression. Mutations in 64 nuclear genes and 34 mitochondrial genes are now known to cause mitochondrial disease and many novel mitochondrial disease genes await discovery. The genetic complexity of oxidative phosphorylation means that maternal, autosomal recessive, autosomal dominant and X-linked modes of inheritance can occur, along with de novo mutations. This complexity presents a challenge in planning efficient molecular genetic diagnosis of patients with suspected mitochondrial disease. In some situations, clinical phenotype can be strongly predictive of the underlying genotype. However, more often this is not the case and it is usually helpful, particularly with pediatric patients, to determine whether the activity of one or more of the individual oxidative phosphorylation enzymes is deficient before proceeding with mutation analysis. In this review we will summarize the genetic bases of mitochondrial disease and discuss some approaches to integrate information from clinical presentation, laboratory findings, family history, and imaging to guide molecular investigation.
This study describes phenotypic and genotypic variations in the planktonic copepod, Centropages typicus (Copepoda: Calanoida) that indicate differentiation between geographical samples. We found consistent differences in the morphology of the chela of the sexually modified fifth pereiopod (P5) of male C. typicus between samples from the Mediterranean, western North Atlantic and eastern North Atlantic. A 560 base pairs (bp) region of the C. typicus mitochondrial cytochrome c oxidase subunit I (COI) and a 462 bp fragment of the nuclear rDNA internal transcribed spacer (ITS) tandem array were analysed to determine whether these morphological variations reflect population genetic differentiation. Mitochondrial haplotype diversity was found to be high with 100 unique COI haplotypes among 116 individuals. Analysis of mtCOI variation suggested differentiation between the Mediterranean and Atlantic populations but no separation was detected within the Atlantic. Intragenomic variation in the ITS array suggested genetic differentiation between samples from the western North Atlantic and those from the eastern North Atlantic and Mediterranean. Breeding experiments would be required to elucidate the extent of genetic isolation between C. typicus from the different population centres.
There is a growing interest in high-order finite and spectral/hp elementmethods using continuous and discontinuous Galerkin formulations. In this paper weinvestigate the effect of h- and p-type refinement onthe relationship between runtime performance and solution accuracy. The broad spectrum ofpossible domain discretisations makes establishing a performance-optimal selectionnon-trivial. Through comparing the runtime of different implementations for evaluatingoperators over the space of discretisations with a desired solution tolerance, wedemonstrate how the optimal discretisation and operator implementation may be selected fora specified problem. Furthermore, this demonstrates the need for codes to support bothlow- and high-order discretisations.
Q fever (Coxiella burnetii) is a zoonotic disease of increasing public health importance. The objective of this study was to estimate the prevalence of, and risk factors associated with, exposure to C. burnetii in cattle in the Republic of Ireland. Bulk-tank milk samples from 290 dairy herds and 1659 sera from 332 dairy and beef herds, randomly sampled, were tested by indirect ELISA to detect antibodies to C. burnetii. In total, 37·9% of bulk-milk sample herds and 1·8% of sera (from 6·9% of herds) were antibody positive. Of risk factors tested using logistic regression analysis, only large herd size (bulk-milk analysis) and dairy breed (serum analysis) significantly increased the odds of being positive for antibodies to C. burnetii. Herds with positive milk or serum samples were randomly distributed throughout the Republic of Ireland and no clustering was observed. The use of an ELISA to test bulk-milk samples collected by randomized stratified sampling is a cost-effective method by which national herd prevalence can be estimated by active surveillance.
An experiment to measure the variation in the phenological and apical development ofwinter wheat (cv. Avalon) in England and Scotland is described. Ten sites which ranged from Aberdeen (57·2° N), the most northerly, to Newton Abbot (50·6° N), the most southerly, were included in the survey, and at each site seed was hand-sown in mid-September, October and November 1983. Developmental stages and sampling procedures were precisely defined to ensure uniformity in scoring by the observers at each site. Temperatures during the growing season were in line with the long-term means, though spring was cooler at all sites and summer warmer at most. The range of monthly-mean temperatures between sites was about the same as the difference between consecutive months. The method of analysis of development rates and durations was in terms of thermal time, modified by sensitivity to photoperiod and a vernalization requirement that slowed early development until a number of days of low temperatures had been experienced. In general, crops at northern sites developed more slowly than those in the south and particularly the south-west of England. There was less variation in the timing of apical stages for later sowings. Developmental rates responded linearly to temperature and photoperiod, with the base temperature increasing for later phases of development. The effect of photoperiod in modifying the rate of development was apparent for all developmental phases from emergence to anthesis, longer days accelerating development, but there was no effect on the duration of the grain-filling period. Vernalization exerted its effect solely within the phase from emergence to double ridge, and had a major influence on the variation between sites only for the first sowing.
The initiation of leaf and spikelet primordia was studied at sites ranging in latitude from Newton Abbot (50·6°N) to Aberdeen (57·2°N) in crops sown in the middle of September, October and November 1983. The rate of primordium initiation tended to decrease from south to north but there were also marked differences between quite close sites.
The rate of leaf initiation increased with temperature but photoperiod had little effect; the rate of spikelet initiation was affected both by temperature and by photoperiod. There were differences in the total number of leaves initiated which were only partlyexplained by differences in vernalization.
Expressing leaf and spikelet initiation rates in terms of thermal and photo-thermal time respectively showed a constant rate of leaf initiation and a constant and more rapid rate of spikelet initiation.
An analysis of development of Golden Promise and Maris Mink spring barley grown in England and in Scotland was made in 1976 and 1977. In both seasons the differences between varieties at a site were small. Rates of leaf emergence and primordium production and the number of primordia formed and the number which died were almost the same at both sites in 1976. In 1977 both leaf emergence and ear initiation started later in Scotland and the rates of leaf emergence and spikelet initiation were slower. Fewer spikelet primordia were formed in Scotland than in England in 1977 but a higher proportion survived to produce potentially fertile florets. Tillers emerged at the same leaf stage of the main shoot and the frequency of tillering differed at some tiller positions between England and Scotland, but the number of tillers produced was similar at both sites.
These results show that in Scotland the effect of longer photoperiod which enhances the rate of leaf emergence and primordium production compensates for the lower temperature which slows down these processes. The lower temperature in Scotland particularly in 1977 during the period of spikelet primordium death increased the proportion of spikelets that survived.
A field and a glasshouse experiment were carried out to assess in winter wheat genotypes the interrelationships between stem and ear development, and to relate these to number of grains and yield. Capelle-Desprez (gai/rht2) and Hobbit ‘s’ (Gai/Rht2) were used together with four F4 lines from the cross between them. Two of the lines were homozygous for gai/rht2 and two lines homozygous for Gai/Rht2. Within each pair of homozygous lines there was a contrast between a tall and a short genotype.
There were no consistent differences in shoot apex morphogenesis between the genotypes, and, in general, similar numbers of spikelets and floret primordia were initiated in all genotypes. This contrasts with the hypothesis that genotypes based on Norin 10 (Gai/Rht2) have a fundamentally different pattern of ear morphogenesis. The main differences between genotypes were in dry-matter partitioning to stem and ear prior to anthesis and these were associated more consistently with the dwarfing gene than with height per se. Gai/Rht2 genotypes partitioned more dry matter to the ear during its development and less to the stem and this was reflected in greater ear weight at anthesis, more fertile florets and grains per spikelet, a higher harvest index and higher grain yield than the gai/rht2 genotypes. Although similar numbers of floret primordia were initiated in all genotypes, assimilate partitioning during development determined the proportion which developed into fertile florets at anthesis.
The spring wheat varieties Kolibri, a typical north temperate variety, Pitic 62, a Mexican variety known to respond to vernalization and two selections from the Institute's breeding programme TW 161 and TJB 155 were sown early (2–5 March), during the normal sowing period (27 March) and late (17 April). Primordium initiation was observed until the time of terminal spikelet initiation and the number of leaves and the number of spikelets were analysed in terms of rate and duration of leaf and spikelet primordium initiation. The rate of leaf initiation was affected by time of sowing but not in a systematic way and there were differences between varieties in the way in which the number of leaves changed in response to sowing time. The rate of spikelet initiation increased and the duration decreased with later sowing. There were strong variety × time of sowing interactions. For almost all characters measured, Pitic 62 responded least to time of sowing. Varieties differed in the way in which the number of spikelets per ear responded to time of sowing but in all cases the changes were only small. This waa because the change in the rate of spikelet initiation was almost exactly compensated for by a change in the duration of spikelet initiation. In each variety, the period from terminal spikelet initiation to ear emergence was similar in all sowing treatments and was of similar duration in the main shoot and in the ear-bearing tillers.
The number of leaves per shoot on the tillers was less than the number of leaves on the main shoot and the rate of spikelet primordium initiation of the tillers was faster than in the main shoot. These changes tended to synchronize the time of terminal spikelet initiation. Because of the changes in the number of leaves per shoot and the rate of spikelet initiation the number of spikelets borne on the main shoot and the tillers were similar although the growth period of the tillers was shorter than that of the main shoot.
Yields of two spring barley varieties, Golden Promise and Maris Mink, were greater at the Scottish Plant Breeding Station (SPBS) than at the Plant Breeding Institute (PBI) in both 1976 and 1977. In both seasons more ears per plant were produced and the number of grains per ear was greater at the SPBS. Weight per grain was greater at the Scottish Plant Breeding Station in both 1976 and 1977, but the distribution of grain size along the ears differed between seasons. Grain at the tip of the ears of plants grown at SPBS in 1976 was lighter than the corresponding grain on the Cambridge-grown plants. In 1977 the SPBS-grown plants had heavier grains at all the main shoot spikelet positions. At the SPBS the relative difference between main shoot and tillers 1 and 2 was smaller than at the PBI.
These results are taken to indicate that the combination of climatic factors in Scotland affects plant development in such a way that intraplant competition is reduced and more spikelet primordia survive to form grains and more tillers produce fertile ears.