36 research outputs found
Hybrid code development for the numerical simulation of instationary magnetoplasmadynamic thrusters
Angular emission distribution of O 1s photoelectrons of uniaxially oriented methanol
The angular distribution of O 1s photoelectrons emitted from uniaxially oriented methanol is studied experimentally and theoretically. We employed circularly polarized photons of an energy of hÎœ = 550 eV for our investigations. We measured the three-dimensional photoelectron angular distributions of methanol, with the CH3âOH axis oriented in the polarization plane, by means of cold target recoil ion momentum spectroscopy. The experimental results are interpreted by single active electron calculations performed with the single center method. A comparative theoretical study of the respective molecular-frame angular distributions of O 1s photoelectrons of CO, performed for the same photoelectron kinetic energy and for a set of different internuclear distances, allows for disentangling the role of internuclear distance and the hydrogen atoms of methanol as compared to carbon monoxide
A case of severe hyperaldosteronism caused by a de novo mutation affecting a critical salt bridge kir3.4 residue.
Sex Differences in Sand Lizard Telomere Inheritance: Paternal Epigenetic Effects Increases Telomere Heritability and Offspring Survival
To date, the only estimate of the heritability of telomere length in wild populations comes from humans. Thus, there is a need for analysis of natural populations with respect to how telomeres evolve.Here, we show that telomere length is heritable in free-ranging sand lizards, Lacerta agilis. More importantly, heritability estimates analysed within, and contrasted between, the sexes are markedly different; son-sire heritability is much higher relative to daughter-dam heritability. We assess the effect of paternal age on Telomere Length (TL) and show that in this species, paternal age at conception is the best predictor of TL in sons. Neither paternal age per se at blood sampling for telomere screening, nor corresponding age in sons impact TL in sons. Processes maintaining telomere length are also associated with negative fitness effects, most notably by increasing the risk of cancer and show variation across different categories of individuals (e.g. males vs. females). We therefore tested whether TL influences offspring survival in their first year of life. Indeed such effects were present and independent of sex-biased offspring mortality and offspring malformations.TL show differences in sex-specific heritability with implications for differences between the sexes with respect to ongoing telomere selection. Paternal age influences the length of telomeres in sons and longer telomeres enhance offspring survival
Bovine telomere dynamics and the association between telomere length and productive lifespan
Average telomere length (TL) in blood cells has been shown to decline with age in a range of vertebrate species, and there is evidence that TL is a heritable trait associated with late-life health and mortality in humans. In non-human mammals, few studies to date have examined lifelong telomere dynamics and no study has estimated the heritability of TL, despite these being important steps towards assessing the potential of TL as a biomarker of productive lifespan and health in livestock species. Here we measured relative leukocyte TL (RLTL) in 1,328 samples from 308 Holstein Friesian dairy cows and in 284 samples from 38 female calves. We found that RLTL declines after birth but remains relatively stable in adult life. We also calculated the first heritability estimates of RLTL in a livestock species which were 0.38 (SEâ=â0.03) and 0.32 (SEâ=â0.08) for the cow and the calf dataset, respectively. RLTL measured at the ages of one and five years were positively correlated with productive lifespan (pâ<â0.05). We conclude that bovine RLTL is a heritable trait, and its association with productive lifespan may be used in breeding programmes aiming to enhance cow longevity
Karyotypic evolutions of cancer species in rats during the long latent periods after injection of nitrosourea
Transgenerational telomere erosion in the monogametic sex: human telomeres progressively erode in the female germline and do not lengthen in aged testes
Cellular Pathophysiology of an Adrenal Adenoma-Associated Mutant of the Plasma Membrane Ca2+-ATPase ATP2B3
Adrenal aldosterone-producing adenomas (APAs) are a main cause for primary aldosteronism leading to arterial hypertension. Physiologically, aldosterone production in the adrenal gland is stimulated by angiotensin II and high extracellular potassium. These stimuli lead to a depolarization of the plasma membrane and, as a consequence, an increase of intracellular Ca2+. Mutations of the plasma membrane Ca2+-ATPase ATP2B3 have been found in APAs with a prevalence of 0.6%-3.1%. Here, we investigated the effects of the APA-associated ATP2B3(Leu425_Val426del) mutation in adrenocortical NCI-H295R and human embryonic kidney (HEK-293) cells. Ca2+ measurements revealed a higher basal Ca2+ level in cells expressing the mutant ATP2B3. This rise in intracellular Ca2+ was even more pronounced under conditions with high extracellular Ca2+ pointing to an increased Ca2+ influx associated with the mutated protein. Furthermore, cells with the mutant ATP2B3 appeared to have a reduced capacity to export Ca2+ suggesting a loss of the physiological pump function. Surprisingly, expression of the mutant ATP2B3 caused a Na+-dependent inward current that strongly depolarized the plasma membrane and compromised the cytosolic cation composition. In parallel to these findings, mRNA expression of the cytochrome P450, family 11, subfamily B, polypeptide 2 (aldosterone synthase) was substantially increased and aldosterone production was enhanced in cells overexpressing mutant ATP2B3. In summary, the APA-associated ATP2B3(Leu425_Val426del) mutant promotes aldosterone production by at least 2 different mechanisms: 1) a reduced Ca2+ export due to the loss of the physiological pump function; and 2) an increased Ca2+ influx due to opening of depolarization-activated Ca2+ channels as well as a possible Ca2+ leak through the mutated pump