86 research outputs found
Early perceptions of an epidemic
This article surveys some descriptions of the Fore people made on early contact in the 1950s by patrol officers, social anthropologists and medical doctors. Sorcery accusations and cannibalism initially impressed these outside observers, though gradually they came to realize that a strange and fatal condition called kuru was a major affliction of the Fore, especially women and children. Fore attributed kuru to sorcery, anthropologists speculated on psychosomatic causes and medical officers began to wonder if it was a mysterious encephalitis
Impact of the intensification of beef production in Brazil on greenhouse gas emissions
The objective of this study was to investigate the impact of increasing pasture productivity using fertilizers, forage legumes, supplements and concentrates, on the emissions of greenhouse gases (GHGs) in five scenarios for beef production with Nellore
cattle in the Cerrado region of Brazil. A life cycle analysis (LCA) approach, from birth of calves to mature animals ready for slaughter at the farm gate, was utilized using both the Tier 1 and Tier 2 methodologies of the Intergovernmental Panel on Climate Change and the results were expressed in carbon dioxide equivalents per kg of carcass produced. The first four scenarios were based solely on cattle production on pasture, ranging from degraded Brachiaria pastures with minimal management, through to a mixed legume/Brachiaria pasture reformed every five years with P and K fertilizers and lime and an improved N fertilized (150 kg N/ha per year) pasture of Guinea grass (Panicum maximum). The most intensive scenario was also based on a fertilized Guinea grass pasture but with a 75 day finishing period in confinement with total mixed ration. To compare scenarios a herd based on 400 cows was utilized. Across the scenarios from 1 to 5 the increase in digestibility promoted a reduction in the forage intake for animal weight gain and a concomitant reduction in methane emissions per herd. For the estimation of nitrous oxide emissions from animal excreta using Tier 2, emission factors from a study in the Cerrado region were utilized which postulated lower emission from dung than from urine and much lower emissions in the long dry season in this region. Fossil carbon dioxide emissions from direct use of fuel and energy were also included in the LCA along with that necessary for the production of fertilizers, supplements and feeds. The greatest impact of intensification of the beef production systems was in the reduction of the area necessary for carcass production from 320 to 45 square meters per kg carcass. Carcass production increased from 43 to 65 Mg per herd across the scenarios from 1 to 5, and total emissions per kg carcass were estimated by Tier 2 methodology to be reduced from 53.7 to 27.9 kg carbon dioxide equivalents. GHG emissions per kg carcass were slightly lower for the mixed grass legume scenario (3), although this was partly due to the lack of data on emissions of nitrous oxide from legume residues. Another large source of uncertainty for the confection of such LCAs was the lack of data for enteric methane emissions from cattle grazing tropical forages
Common variants near MC4R are associated with fat mass, weight and risk of obesity.
To identify common variants influencing body mass index (BMI), we analyzed genome-wide association data from 16,876 individuals of European descent. After previously reported variants in FTO, the strongest association signal (rs17782313, P = 2.9 x 10(-6)) mapped 188 kb downstream of MC4R (melanocortin-4 receptor), mutations of which are the leading cause of monogenic severe childhood-onset obesity. We confirmed the BMI association in 60,352 adults (per-allele effect = 0.05 Z-score units; P = 2.8 x 10(-15)) and 5,988 children aged 7-11 (0.13 Z-score units; P = 1.5 x 10(-8)). In case-control analyses (n = 10,583), the odds for severe childhood obesity reached 1.30 (P = 8.0 x 10(-11)). Furthermore, we observed overtransmission of the risk allele to obese offspring in 660 families (P (pedigree disequilibrium test average; PDT-avg) = 2.4 x 10(-4)). The SNP location and patterns of phenotypic associations are consistent with effects mediated through altered MC4R function. Our findings establish that common variants near MC4R influence fat mass, weight and obesity risk at the population level and reinforce the need for large-scale data integration to identify variants influencing continuous biomedical traits
Combined use of ionophore and virginiamycin for finishing Nellore steers fed high concentrate diets
Zebu cattle fed high concentrate diets may present inconsistent performance due to the occurrence of metabolic disorders, like acidosis. The isolated use of ionophores and virginiamycin in high grain diets can improve animal performance and reduce the incidence of such disorders, but recent studies suggested that their combination may have an additive effect. Thus, 72 Nellore steers, 389 ± 15 kg initial body weight (BW), were confined and fed for 79 days to evaluate the combination of virginiamycin and salinomycin on performance and carcass traits. Animals were allocated to a randomized complete block design by BW, in a 2 × 2 factorial arrangement of treatments, with two concentrate levels (73 and 91 %) and two virginiamycin levels (0 and 15 mg kg-1), and salinomycin (13 mg kg-1) included in all diets. The interaction was not significant (p > 0.05). Dry matter intake (DMI), average daily gain (ADG), gain-to-feed ratio (G:F), starch consumed, and fecal starch content were higher (p 0.05) between treatments. Starch consumed and estimated dietary net energy for maintenance (NEm) and gain (NEg) were higher (p < 0.05) for virginiamycin-treated animals, with no substantial effects on carcass traits. The inclusion of virginiamycin in finishing diets containing salinomycin reduced DMI while maintaining ADG and improving NEm and NEg, suggesting an additive effect of virginiamycin and ionophores, but without affecting carcass quality
Associations of autozygosity with a broad range of human phenotypes
In many species, the offspring of related parents suffer reduced reproductive success, a phenomenon known as inbreeding depression. In humans, the importance of this effect has remained unclear, partly because reproduction between close relatives is both rare and frequently associated with confounding social factors. Here, using genomic inbreeding coefficients (FROH) for >1.4 million individuals, we show that FROH is significantly associated (p < 0.0005) with apparently deleterious changes in 32 out of 100 traits analysed. These changes are associated with runs of homozygosity (ROH), but not with common variant homozygosity, suggesting that genetic variants associated with inbreeding depression are predominantly rare. The effect on fertility is striking: FROH equivalent to the offspring of first cousins is associated with a 55% decrease [95% CI 44–66%] in the odds of having children. Finally, the effects of FROH are confirmed within full-sibling pairs, where the variation in FROH is independent of all environmental confounding
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