Improving stress coping ability: comparison between the CYP17 genotype Of Ovis Aries and Capra Hircus

The ability of animals to adapt to stress is not only an animal health and welfare concern, but also influences reproduction potential and robustness. An important pathway involved in the stress response is the hypothalamic-pituitary-adrenal axis (HPAA) that results in the release of cortisol from the adrenal gland. In this study the cortisol responses of South African Merinos were measured to assess HPAA responsiveness to stress and relate it to behavioural stress responses to flock-isolation. The experiment was structured according to a 2×2 statistical design, with CYP17 genotype (WT1/WT1 vs. WT1/WT2) and selection line (H-line vs. L-line) as factors. Selection line criteria was based on divergent selection for (H-line) or against (L-line) maternal multiple rearing ability, where the H-line generally outperformed the L-line in terms of reproduction, animal welfare and resistance to certain pathogens. The CYP17 genotype is involved in the biosynthesis pathway of cortisol. In the present study the CYP17 genotype showed a significant influence on behavioural stress responses, where three parameters of the flock-isolation test were affected (P<0.05), namely the number of bleats uttered, the urinating frequency and the average distance from a human operator. It is suggested that the CYP17 genotype affects behavioural responses via its effects on cortisol production, and that the SNPs located within the CYP17 genotype may have application in marker-assisted selection of sheep

The role of Cytochrome P450 17-alpha-Hydroxylase/ 17,20-Lyase (CYP17) in the stress coping ability in a divergently selected Merino sheep population

South African Merino sheep were selected divergently from the same base population for their ability to rear multiples. Two distinct populations were formed over a period of more than 20 years of selection. Reproduction (and therefore presumably fitness) in the line selected in the upward direction (H-line) was substantially improved compared to the line selected in the downward direction (L-line). In the present study, it was demonstrated that the H-line was more stresstolerant than the L-line in terms of their glucose and cortisol response when challenged with insulin. Sheep from the breeding program were genotyped according to one of two cytochrome P450 17α-hydroxylase/17-20 lyase (CYP17) alleles, as these genotypes were previously linked to the ability of Angora goats to cope with external stressors. However, no association was found between CYP17 genotype and selection line. The difference in insulin induced stress response between the H- and the L-line can therefore not be attributed to CYP17 genotype

Robust zero-energy modes in an electronic higher-order topological insulator: the dimerized Kagome lattice

Quantum simulators are an essential tool for understanding complex quantum materials. Platforms based on ultracold atoms in optical lattices and photonic devices led the field so far, but electronic quantum simulators are proving to be equally relevant. Simulating topological states of matter is one of the holy grails in the field. Here, we experimentally realize a higher-order electronic topological insulator (HOTI). Specifically, we create a dimerized Kagome lattice by manipulating carbon-monoxide (CO) molecules on a Cu(111) surface using a scanning tunneling microscope (STM). We engineer alternating weak and strong bonds to show that a topological state emerges at the corner of the non-trivial configuration, while it is absent in the trivial one. Contrarily to conventional topological insulators (TIs), the topological state has two dimensions less than the bulk, denoting a HOTI. The corner mode is protected by a generalized chiral symmetry, which leads to a particular robustness against perturbations. Our versatile approach to quantum simulation with artificial lattices holds promises of revealing unexpected quantum phases of matter

Maximum and minimum toughness of graphs of small genus

AbstractA new lower bound on the toughness t(G) of a graph G in terms of its connectivity ϰ(G) and genus γ(G) is obtained. For γ > 0, the bound is sharp via an infinite class of extremal graphs all of girth 4. For planar graphs, the bound is t(G) > ϰ(G)/2 − 1. For ϰ = 1 this bound is not sharp, but for each ϰ = 3, 4, 5 and any ϵ > 0, infinite families of graphs {G(ϰ, ϵ)} are provided with ϰ(G(ϰ, ϵ)) = ϰ, but t(G(ϰ, ϵ)) < ϰ/2 − 1 + ϵ.Analogous investigations on the torus are carried out, and finally the question of upper bounds is discussed. Several unanswered questions are posed

Age of diagnosis of congenital hearing loss: Private v. public healthcare sector

Background. The age of diagnosis of congenital hearing loss is one of the most important determinants of communication outcome. A previous study by the lead author had evaluated the performance of the public health services in Bloemfontein, South Africa (SA), in this regard. This study aimed to examine whether the private health services in the same city were any better.Objective. To determine whether the age of diagnosis of congenital hearing loss (CHL) in children seen in the private healthcare sector in Bloemfontein, Free State Province, SA, was lower than that in the public healthcare system in the same city.Methods. A comparative study design was utilised and a retrospective database review conducted. Data obtained from this study in the private healthcare sector were compared with data from a previous study in the public healthcare sector using the same study design.Results. Forty-eight children aged &lt;6 years with disabling hearing impairment (DHI) were identified in the private healthcare sector during the study period; 33/47 (70.2%) did not undergo hearing screening at birth. The median age of diagnosis of DHI in the private healthcare sector was 2.24 years, and this was statistically significantly lower than the median age of diagnosis of 3.71 years in the public healthcare sector (p&lt;0.0001; 95% confidence interval (CI) 0.99 - 2.0). The median age of diagnosis of CHL in the private healthcare sector was 3.01 years in children who were not screened at birth, and 1.25 years in those who were screened at birth. This difference was statistically significant (p&lt;0.01; 95% CI 0.72 - 2.47). We also compared the median age of diagnosis of CHL in children from the private healthcare sector who were not screened at birth (median 3.01 years) with that in children in the public healthcare sector (median 3.71 years). This difference was statistically significant (p&lt;0.01; 95% CI 0.41 - 1.56).Conclusions. Children in the Free State are diagnosed with CHL at a younger age in the private healthcare sector than in the public healthcare sector. With the social and economic benefits of early intervention in cases of DHI well established internationally, SA healthcare providers in both the public and private sectors need to develop screening, diagnostic and (re)habilitation services for children with hearing impairment

Improving stress coping ability: comparison between the CYP17 genotype Of Ovis Aries and Capra Hircus

The ability of animals to adapt to stress is not only an animal health and welfare concern, but also influences reproduction potential and robustness. An important pathway involved in the stress response is the hypothalamic-pituitary-adrenal axis (HPAA) that results in the release of cortisol from the adrenal gland. In this study the cortisol responses of South African Merinos were measured to assess HPAA responsiveness to stress and relate it to behavioural stress responses to flock-isolation. The experiment was structured according to a 2×2 statistical design, with CYP17 genotype (WT1/WT1 vs. WT1/WT2) and selection line (H-line vs. L-line) as factors. Selection line criteria was based on divergent selection for (H-line) or against (L-line) maternal multiple rearing ability, where the H-line generally outperformed the L-line in terms of reproduction, animal welfare and resistance to certain pathogens. The CYP17 genotype is involved in the biosynthesis pathway of cortisol. In the present study the CYP17 genotype showed a significant influence on behavioural stress responses, where three parameters of the flock-isolation test were affected (P&#60;0.05), namely the number of bleats uttered, the urinating frequency and the average distance from a human operator. It is suggested that the CYP17 genotype affects behavioural responses via its effects on cortisol production, and that the SNPs located within the CYP17 genotype may have application in marker-assisted selection of sheep

Influence of territorial aggressiveness of ostrich males on egg production of companion female ostriches

(South African J of Animal Science, 2000, 30, Supplement 1: 68-69