RECIPROCAL RECURRENT SELECTION FOR 21-DAY LITTER WEIGHT OF CROSSBRED GILTS. I. SELECTION APPLIED AND GENETIC CHANGE IN REPRODUCTION OF CROSSBRED GILTS

Six cycles of reciprocal recurrent selection (RRS) between Line 8 (Duroc) and Line 9 (Beltsville No. 1) were completed at the Fort Reno Livestock Research Center, E1 Reno, Oklahoma. A randomly mated control line was maintained. Each cycle of selection required three seasons. Selection of purebred pigs (born in the second season) was based on the mean 21-d litter weight of their maternal and paternal half-sib crossbred gilts that were born in the first season and farrowed in the third season (XB21DLWT). On the average, 5.8 maternal and paternal half-sib gilts contributed to the mean XB21DLWT for each purebred individual. The average potential selection differential for XB21DLWT was 5.64 kg, but only 70.2% of this value was realized in the initial selection (3.95 kg). Disease problems and unsoundness were the primary reasons for this discrepancy. The potential, initial, final and weighted final standardized selection differentials for females averaged 61, 60, 55 and 47%, respectively, of the corresponding differentials for males. Standardized selection differentials were similar for Line 8 and Line 9. The estimate of realized heritability for XB21DLWT was .076 ± .319 for the average of 8 x 9 and 9 x 8 gilts. Environmental trends, estimated from control data, were not significant for any of the traits evaluated. The genetic change in reproductive ability of 8 x 9, 9 x 8 and their unweighted average was estimated by regressing the deviation of the line mean from the control mean on generation number. In general, estimates of genetic change for litter size, litter weight and average pig weight/litter at 0, 21 and 42 d of age were not significant, but all estimates were favorable. The estimated genetic change for 21-d litter weight was 1.04 ± 1.25 kg/cycle of selection. Based on these results and considering the complexity of RRS, the increase in generation interval and the expected decline in purebred performance that theoretically should accompany successful RRS, it seems doubtful that RRS can be more beneficial than selection based on purebred performance as a method to improve productivity of crossbred gilts

RECIPROCAL RECURRENT SELECTION FOR 21-DAY LITTER WEIGHT OF CROSSBRED GILTS. II. REPRODUCTIVE PERFORMANCE OF PUREBRED FEMALES PRODUCING PUREBRED AND TWO-WAY CROSS LITTERS AND PERFORMANCE OF PUREBRED AND CROSSBRED PIGS

This paper reports estimates of correlated genetic change in reproductive performance of purebred gilts producing two-way cross litters and purebred sows producing purebred litters as well as postweaning performance of two-way cross and purebred pigs produced during reciprocal recurrent selection (RRS) between Line 8 (Duroc) and Line 9 (Beltsville No. 1) for 21-d litter weight production of crossbred gilts. A randomly mated control line developed from a crossbred foundation was maintained to monitor environmental change. Data were adjusted for age of dam, inbreeding of dam, inbreeding of litter (or pig) and linear and quadratic effects of day born within season. The traits evaluated were: litter size, litter weight and average pig weight/litter at birth and weaning (42 d); postweaning average daily gain; age at 90.7 kg and backfat thickness at 90.7 kg. Two data sets were analyzed; the first set included seven seasons of data with purebred gilts producing two-way cross litters, and the second set included seven seasons of data with purebred sows producing purebred litters. No estimates of environmental trend were significant in either set of data. In the first data set, only the estimate of genetic change in backfat thickness of two-way cross pigs was significant and it was in the desired direction. All other estimates were small and did not approach significance. In the second data set, estimates of genetic trend were greater in Line 9 than in Line 8. Estimates of genetic trend in Line 9 were significant for average pig weight at birth, age at 90.7 kg and backfat probe at 90.7 kg, and approached significance for litter size at weaning and average daily gain. The estimates were undesirable for preweaning traits and desirable for postweaning traits. The estimates of genetic trend in Line 8 were of the same sign as those in Line 9, but only the estimate for backfat thickness was significant. The decrease in size of purebred litters in Line 9, and to some degree Line 8, suggests an accelerated accumulation of homozygosity beyond that accounted for by adjustment for pedigree inbreeding. The fact that Line 9 showed a greater decrease than Line 8 suggests that most of the increase in level of reproduction of crossbred gilts may have resulted from genetic change in Line 9 rather than Line 8, or that favorable alleles were being fixed in Line 8 and unfavorable alleles in Line 9

UK experience of liver transplantation for erythropoietic protoporphyria

Erythropoietic protoporphyria (EPP) is characterised by excess production of free protoporphyrin from the bone marrow, most commonly due to deficiency of the enzyme ferrochelatase. Excess protoporphyrin gives rise to the cutaneous photosensitivity characteristic of the disease, and in a minority of patients leads to end-stage liver disease necessitating liver transplantation (LT). There is limited information regarding the timing, impact and long-term outcome of LT in such patients, thus we aimed to identify the indications and outcomes of all transplants performed for EPP in the UK using data from the UK Transplant Registry. Between 1987 and 2009, five patients underwent LT for EPP liver disease. Median follow-up was 60 months, and there were two deaths at 44 and 95 months from causes unrelated to liver disease. The remaining recipients are alive at 22.4 years, 61 months and 55 months after transplant. A high rate of postoperative biliary stricturing requiring multiple biliary interventions was observed. Recurrent EPP-liver disease occurred in 4/5 (80%) of patients but graft failure has not been observed. Given the role of biliary obstruction in inducing EPP-mediated liver damage, we suggest that consideration should be given for construction of a Roux loop at the time of transplant. Thus we demonstrate that although EPP liver transplant recipients have a good long-term survival, comparable to patients undergoing LT for other indications, biliary complications and disease recurrence are almost universal, and bone marrow transplantation should be considered where possible

Mann and gender in Old English prose : a pilot study

It has long been known that OE mann was used in gender-neutral as well as gender-specific contexts. Because of the enormous volume of its attestations in Old English prose, the more precise usage patterns of mann remain, however, largely uncharted, and existing lexicographical tools provide only a basic picture. This article aims to present a preliminary study of the various uses of mann as attested in Old English prose, particularly in its surprisingly consistent use by an individual author, namely that of the ninth-century Old English Martyrology. Patterns emerging from this text are then tested against other prose material. Particular attention is paid to gender-specific usage, examples of which are shown to be exceptional for a word which largely occurs in gender-neutral contexts.Publisher PDFPeer reviewe

The “conscious pilot”—dendritic synchrony moves through the brain to mediate consciousness

Cognitive brain functions including sensory processing and control of behavior are understood as “neurocomputation” in axonal–dendritic synaptic networks of “integrate-and-fire” neurons. Cognitive neurocomputation with consciousness is accompanied by 30- to 90-Hz gamma synchrony electroencephalography (EEG), and non-conscious neurocomputation is not. Gamma synchrony EEG derives largely from neuronal groups linked by dendritic–dendritic gap junctions, forming transient syncytia (“dendritic webs”) in input/integration layers oriented sideways to axonal–dendritic neurocomputational flow. As gap junctions open and close, a gamma-synchronized dendritic web can rapidly change topology and move through the brain as a spatiotemporal envelope performing collective integration and volitional choices correlating with consciousness. The “conscious pilot” is a metaphorical description for a mobile gamma-synchronized dendritic web as vehicle for a conscious agent/pilot which experiences and assumes control of otherwise non-conscious auto-pilot neurocomputation

Efeito do genótipo e da idade de ovinos na reatividade medida em pista de venda

Objetivou-se avaliar o comportamento de ovinos e relacionar aspectos comportamentais com a raça e idade dos animais. Foram observados 5.971 animais divididos em 181 lotes quanto às raças – Corriedale (n = 2.731), Ideal (n = 1.574), Merino (n = 168), Texel (n = 717), Suffolk (n = 247) e 6 mestiços (n = 534) – e quanto à idade – cordeiras (1,5 ano, n = 3.021), ovelhas (acima de 1,5 ano, n = 2457) e cordeiras dente-de-leite (média de 6 meses de idade, n = 493). O comportamento médio dos lotes foi avaliado pela atribuição de escores de movimentação e resistência à condução na entrada, permanência e saída da pista de comercialização. Os animais das raças mais especializadas para produção de carne (Suffolk e Texel) e os animais jovens foram os mais agitados e apresentaram maior resistência à condução pelo homem em comparação àqueles das raças produtoras de lã e aos mais velhos. Os escores comportamentais foram positivamente relacionados entre si, o que permite a escolha de qualquer um deles para medir o comportamento dos ovinos. O comportamento de ovinos em pista de venda é influenciado pela idade e raça.The objective of this work was to evaluate behavior of sheep and to relate behavioral aspects with breed and age of animals. It was observed 5,971 animals distributed in 181 plots regarded to: breed - Corriedale (n=2,731), Ideal (n=1,574), Merino (n=168), Texel (n=717), Suffolk (n=247) and six crossbreds (n=534); age - yearlings (1.5 year, n=3,021), ewes (above 1.5 year, n =2,457) and lambs (average 6 months of age, n=493). Average behavior of plots was evaluated by attributing scores of movement and resistance to conduction at entrance, permanence and exit from the market auction. Animals from more specialized breeds for meat production (Sulfock and Texel) and young animals were the most agitated and they showed more resistance to human conduction compared to those wool producer breeds and to the older ones. Behavior scores positively correlated among each other, allowing to choose any of them to measure sheep behavior. Sheep on market auction behavior is influenced by age and breed

International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist

The topographic evolution of the Tibetan Region as revealed by palaeontology

The Tibetan Plateau was built through a succession of Gondwanan terranes colliding with Asia during the Mesozoic. These accretions produced a complex Paleogene topography of several predominantly east–west trending mountain ranges separated by deep valleys. Despite this piecemeal assembly and resultant complex relief, Tibet has traditionally been thought of as a coherent entity rising as one unit. This has led to the widely used phrase ‘the uplift of the Tibetan Plateau’, which is a false concept borne of simplistic modelling and confounds understanding the complex interactions between topography climate and biodiversity. Here, using the rich palaeontological record of the Tibetan region, we review what is known about the past topography of the Tibetan region using a combination of quantitative isotope and fossil palaeoaltimetric proxies, and present a new synthesis of the orography of Tibet throughout the Paleogene. We show why ‘the uplift of the Tibetan Plateau’ never occurred, and quantify a new pattern of topographic and landscape evolution that contributed to the development of today’s extraordinary Asian biodiversity