15 research outputs found
A detective story: emphatics in Mehri
Until 1970, Ethio-Semitic was believed to be the only Semitic language sub-family in which the main correlate of “emphasis” is
glottalization, a feature said at the time to be due to Cushitic influence. Since the work of T.M. Johnstone, however, it has been
argued that glottalization is a South Semitic feature, attested not only in Ethio-Semitic, but also in the Modern South Arabian
languages. Two statements in the literature on Modern South Arabian, however, suggested to us that the original evidence needed
to be re-investigated: first, some of the “ejectives” are described as at least partially voiced, not a phonetic impossibility, but so
far unheard of in the phonological system of any language; and secondly, the degree of glottalization is frequently described
as dependent on the phonological environment, although details of the environment in which emphatics are always realized as
ejectives are not given. In this paper, we consider acoustic data from Mahriyōt (a Mehri dialect spoken in the easternmost province
of Yemen), we examine descriptions of emphatics in other dialects of Mehri and other Modern South Arabian languages, we look at
phonological environments in which emphatics are realized as ejectives and those in which they are not, and we conclude that the
file on emphasis in these languages needs to be re-opened to fresh judgement
Quantum dynamics of a single, mobile spin impurity
Quantum magnetism describes the properties of many materials such as transition metal oxides and cuprate superconductors. One of its elementary processes is the propagation of spin excitations. Here we study the quantum dynamics of a deterministically created spin-impurity atom, as it propagates in a one-dimensional lattice system. We probe the full spatial probability distribution of the impurity at different times using single-site-resolved imaging of bosonic atoms in an optical lattice. In the Mott-insulating regime, a post-selection of the data allows to reduce the effect of temperature, giving access to a space- and time-resolved measurement of the quantum-coherent propagation of a magnetic excitation in the Heisenberg model. Extending the study to the bath's superfluid regime, we determine quantitatively how the bath strongly affects the motion of the impurity. The experimental data shows a remarkable agreement with theoretical predictions allowing us to determine the effect of temperature on the coherence and velocity of impurity motion. Our results pave the way for a new approach to study quantum magnetism, mobile impurities in quantum fluids, and polarons in lattice systems
Alcohol consumption, endogenous estrogen and mammographic density among premenopausal women
Introduction: Alcohol consumption may promote aromatization of androgens to estrogens, which may partly explain the observations linking alcohol consumption to higher breast cancer risk. Whether alcohol consumption is associated with endogenous estrogen levels, and mammographic density phenotypes in premenopausal women remains unclear. Methods: Alcohol consumption was collected by self-report and interview, using semi quantitative food frequency questionnaires, and a food diary during seven days of a menstrual cycle among 202 premenopausal women, participating in the Energy Balance and Breast Cancer Aspects (EBBA) study I. Estrogen was assessed in serum and daily in saliva across an entire menstrual cycle. Computer-assisted mammographic density (Madena) was obtained from digitized mammograms taken between days 7–12 of the menstrual cycle. Multivariable regression models were used to investigate the associations between alcohol consumption, endogenous estrogen and mammographic density phenotypes. Results: Current alcohol consumption was positively associated with endogenous estrogen, and absolute mammographic density. We observed 18 % higher mean salivary 17β-estradiol levels throughout the menstrual cycle, among women who consumed more than 10 g of alcohol per day compared to women who consumed less than 10 g of alcohol per day (p = 0.034). Long-term and past-year alcohol consumption was positively associated with mammographic density. We observed a positive association between alcohol consumption (past year) and absolute mammographic density; high alcohol consumers (≥7 drinks/week) had a mean absolute mammographic density of 46.17 cm2 (95 % confidence interval (CI) 39.39, 52.95), while low alcohol consumers (32.4 cm2), compared to low (<1 drink/week) alcohol consumers. Conclusion: Alcohol consumption was positively associated with daily endogenous estrogen levels and mammographic density in premenopausal women. These associations could point to an important area of breast cancer prevention. Electronic supplementary material The online version of this article (doi:10.1186/s13058-015-0620-1) contains supplementary material, which is available to authorized users
Reproductive endocrinology of zoo-housed aardwolves
Knowledge regarding the relationship between endocrine parameters and reproductive activity
can offer important insights into how social and environmental factors influence the
reproductive success of mammals. Although components of both the physical and social
environment affect endocrine regulation of reproduction, less is understood about the
potential role of interactions between different endocrine axes on reproductive activity. We
evaluated temporal patterns of reproductive and adrenocortical steroids in two male and three
female aardwolves (Proteles cristata) housed in captivity at Brookfield Zoo, Chicago, USA.
We found seasonal variation in faecal androgens, estrogens, and progestagens, which provide
support for previous observations of the aardwolf as a seasonal breeder. However, the timing
of peak endocrine activity did not correspond to observations from wild populations. Our
interpretation is that this discrepancy is caused by photoperiodic regulation of reproductive
activity. We found a positive relationship between faecal androgens and faecal glucocorticoid
metabolites in males and a positive relationship between faecal estrogens and faecal
glucocorticoid metabolites in females when housed with conspecifics but not when housed
alone. We also found a positive but asymptotic relationship between faecal progestagens and
faecal glucocorticoid metabolites. We argue that these observations indicate a potential effect
of reproductive endocrine activity on the hypothalamic-pituitary adrenal axis, which could
result in interesting physiological trade-offs in male reproductive tactics and female prepartum
maternal investment because of the negative effects of long-term glucocorticoid
elevation on reproductive performance. Finally, our results suggest that social and
environmental factors interact in regulating many aspects of endocrine fluctuations in this
mostly solitary species.D. Marneweck, F. Dalerum and A. Ganswindt were supported by the National Research Foundation of South Africa, and F. Dalerum and A. Ganswindt were further supported by research fellowships from University of Pretoria.http://acta.zbs.bialowieza.pl/hb2013ab201