3,229 research outputs found
Empirical radius formulas for canonical neutron stars from bidirectionally selecting EOS features in extended Bayesian analyses of observational data
Given the significant advancement in Bayesian inference of nuclear Equation
of State (EOS) from gravitational wave and X-ray observations of neutron stars
(NSs), especially since GW170817, is there a data-driven and robust empirical
formula for the radius of canonical NSs in terms of the
characteristic EOS parameters (features)? What is the single most important but
currently poorly known EOS parameter for determining the ? We study
these questions by extending the traditional Bayesian analysis which normally
ends at presenting the marginalized posterior probability distribution
functions (PDFs) of individual EOS parameters and their correlations (or
sometimes only the Pearson correlation coefficients which are only reliably
useful when the variables are linearly correlated while they are actually often
not). Using three regression model-building methodologies: bidirectional
step-wise feature selection, Least Absolute Shrinkage Selection Operator
(LASSO) regression, and neural network regression on a large set of posterior
EOSs and the corresponding values inferred from earlier comprehensive
Bayesian analyses of NS observational data, we systematically and rigorously
develop the most probable formulas with varying statistical accuracy
and technical complexity. The most important EOS parameters for determining
are found consistently in each of the feature/model selection
processes to be (in order of decreasing importance): curvature , slope
, skewness of nuclear symmetry energy, skewness ,
incompressibility of symmetric nuclear matter, and the magnitude
of symmetry energy at the saturation density of
nuclear matter.Comment: Phys. Rev. C (2023) in pres
Rats with physically disconnected hypothalamo-pituitary tracts no longer contain vasopressin-oxytocin gene transcripts in the posterior pituitary lobe
AbstractIn rats, vasopressin- and oxytocin-encoding mRNAs are present in the posterior but absent in the anterior lobe of the pituitary gland. RNase protection experiments indicate that in the posterior pituitary and hypothalamus identical transcriptional start points are used. Furthermore, the two transcripts from posterior pituitary and hypothalamus show identical nucleotide sequences. Animals operated by paired electrical lesions in such a way that connections between the supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus and the posterior pituitary lobeare destroyed continue to express the vasopressin and oxytocin gene in the hypothalamus but not in the posterior pituitary. Operated animals subjected to chronic intermittent salt loading for 6 days similarly contain vasopressin and oxytocin encoding transcripts in the hypothalamus but not in the posterior pituitary
Twenty Thousand-Year-Old Huts at a Hunter-Gatherer Settlement in Eastern Jordan
Ten thousand years before Neolithic farmers settled in permanent villages, hunter-gatherer groups of the Epipalaeolithic period (c. 22â11,600 cal BP) inhabited much of southwest Asia. The latest Epipalaeolithic phase (Natufian) is well-known for the appearance of stone-built houses, complex site organization, a sedentary lifestyle and social complexityâprecursors for a Neolithic way of life. In contrast, pre-Natufian sites are much less well known and generally considered as campsites for small groups of seasonally-mobile hunter-gatherers. Work at the Early and Middle Epipalaeolithic aggregation site of Kharaneh IV in eastern Jordan highlights that some of these earlier sites were large aggregation base camps not unlike those of the Natufian and contributes to ongoing debates on their duration of occupation. Here we discuss the excavation of two 20,000-year-old hut structures at Kharaneh IV that pre-date the renowned stone houses of the Natufian. Exceptionally dense and extensive occupational deposits exhibit repeated habitation over prolonged periods, and contain structural remains associated with exotic and potentially symbolic caches of objects (shell, red ochre, and burnt horn cores) that indicate substantial settlement of the site pre-dating the Natufian and outside of the Natufian homeland as currently understood
In Vitro Model for Hepatotoxicity Studies Based on Primary Human Hepatocyte Cultivation in a Perfused 3D Bioreactor System
Accurate prediction of the potential hepatotoxic nature of new pharmaceuticals
remains highly challenging. Therefore, novel in vitro models with improved
external validity are needed to investigate hepatic metabolism and timely
identify any toxicity of drugs in humans. In this study, we examined the
effects of diclofenac, as a model substance with a known risk of
hepatotoxicity in vivo, in a dynamic multi-compartment bioreactor using
primary human liver cells. Biotransformation pathways of the drug and possible
effects on metabolic activities, morphology and cell transcriptome were
evaluated. Formation rates of diclofenac metabolites were relatively stable
over the application period of seven days in bioreactors exposed to 300 ”M
diclofenac (300 ”M bioreactors (300 ”M BR)), while in bioreactors exposed to
1000 ”M diclofenac (1000 ”M BR) metabolite concentrations declined
drastically. The biochemical data showed a significant decrease in lactate
production and for the higher dose a significant increase in ammonia
secretion, indicating a dose-dependent effect of diclofenac application. The
microarray analyses performed revealed a stable hepatic phenotype of the cells
over time and the observed transcriptional changes were in line with
functional readouts of the system. In conclusion, the data highlight the
suitability of the bioreactor technology for studying the hepatotoxicity of
drugs in vitro
Preoperative Voice Parameters Affect the Postoperative Speech Intelligibility in Patients with Cochlear Implantation
ObjectivesVerbal communication depends on a good function of voice and speech organs. Some of the voice characteristics of deaf people differ considerably from those of speakers with normal hearing. After cochlear implantation (CI), auditory control of voice production is possible and the quality of the voice is improved. CI improves quality of voice, speech and hearing with deafness. The aim of our study was to investigate the relationship between acoustic analysis before CI and the speech intelligibility before and after CI.MethodsTwelve prelingually deafened children implanted unilaterally at the age of 3.4-9 years were included in the study. For all of the children an acoustic analysis of the Slovene vowel 'a' was performed before CI. The fundamental frequency (F0), jitter, shimmer and noise-to-harmonic ratio (NHR) were studied before the implantation. For all of the children the speech intelligibility was performed before and 12 months after CI. Preoperative hearing was divided on existing residual hearing. The results of the acoustic analyses and speech intelligibility before and after CI were compared for preoperative hearing. The results of the speech intelligibility were compared for the age of operation and preoperative acoustic analysis (F0, jitter, shimmer, NHR).ResultsPreoperative hearing had no influence on preoperative voice analysis. The children with residual hearing had a high grade of speech intelligibility before and after CI. The preoperative shimmer had positive correlation with postoperative 12 month speech intelligibility (r=0.618, P=0.032). The preoperative jitter had positive correlation with postoperative 12 month speech intelligibility, but was not statistically significant (r=0.479, P=0.116).ConclusionShimmer on preoperative voice analyses had influence on speech intelligibility after CI
Arbitrary-order lensless ghost imaging with thermal light
Arbitrary Nth-order () lensless ghost imaging with thermal light has
been performed for the first time by only recording the intensities in two
optical paths. It is shown that the image visibility can be dramatically
enhanced as the order N increases. It is also found that longer integration
times are required for higher-order correlation measurements as N increases,
due to the increased fluctuations of higher-order intensity correlation
functions.Comment: Updated version; some more detailed explanations provide
A Unique Human-Fox Burial from a Pre-Natufian Cemetery in the Levant (Jordan)
New human burials from northern Jordan provide important insights into the appearance of cemeteries and the nature of human-animal relationships within mortuary contexts during the Epipalaeolithic period (c. 23,000â11,600 cal BP) in the Levant, reinforcing a socio-ideological relationship that goes beyond predator-prey. Previous work suggests that archaeological features indicative of social complexity occur suddenly during the latest Epipalaeolithic phase, the Natufian (c. 14,500â11,600 cal BP). These features include sedentism, cemeteries, architecture, food production, including animal domestication, and burials with elaborate mortuary treatments. Our findings from the pre-Natufian (Middle Epipalaeolithic) cemetery of âUyun al-Hammam demonstrate that joint human-animal mortuary practices appear earlier in the Epipalaeolithic. We describe the earliest human-fox burial in the Near East, where the remains of dogs have been found associated with human burials at a number of Natufian sites. This is the first time that a fox has been documented in association with human interments pre-dating the Natufian and with a particular suite of grave goods. Analysis of the human and animal bones and their associated artefacts provides critical data on the nature and timing of these newly-developing relationships between people and animals prior to the appearance of domesticated dogs in the Natufian
Socio-demographic and behavioural correlates of oral hygiene status and oral health related quality of life, the Limpopo - Arusha school health project (LASH): A cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Promoting oral health of adolescents is important for improvement of oral health globally. This study used baseline-data from LASH-project targeting secondary students to; 1) assess frequency of poor oral hygiene status and oral impacts on daily performances, OIDP, by socio-demographic and behavioural characteristics, 2) examine whether socio-economic and behavioural correlates of oral hygiene status and OIDP differed by gender and 3) examine whether socio-demographic disparity in oral health was explained by oral health-related behaviours.</p> <p>Methods</p> <p>Cross-sectional study was conducted in 2009 using one-stage cluster sampling design. Total of 2412 students (mean age 15.2 yr) completed self-administered questionnaires, whereas 1077 (mean age 14.9 yr) underwent dental-examination. Bivariate analyses were conducted using cross-tabulations and chi-square statistics. Multiple variable analyses were conducted using stepwise standardized logistic regression (SLR) with odds ratios and 95% Confidence intervals (CI).</p> <p>Results</p> <p>44.8% presented with fair to poor OHIS and 48.2% reported any OIDP. Older students, those from low socio-economic status families, had parents who couldn't afford dental care and had low educational-level reported oral impacts, poor oral hygiene, irregular toothbrushing, less dental attendance and fewer intakes of sugar-sweetened drinks more frequently than their counterparts. Stepwise logistic regression revealed that reporting any OIDP was independently associated with; older age-groups, parents do not afford dental care, smoking experience, no dental visits and fewer intakes of sugar-sweetened soft drinks. Behavioural factors accounted partly for association between low family SES and OIDP. Low family SES, no dental attendance and smoking experience were most important in males. Low family SES and fewer intakes of sugar-sweetened soft drinks were the most important correlates in females.</p> <p>Socio-behavioural factors associated with higher odds ratios for poor OHIS were; older age, belonging to the poorest household category and having parents who did not afford dental care across both genders.</p> <p>Conclusion</p> <p>Disparities in oral hygiene status and OIDP existed in relation to age, affording dental care, smoking and intake of sugar sweetened soft drinks. Gender differences should be considered in intervention studies, and modifiable behaviours have some relevance in reducing social disparity in oral health.</p
The Anthropocene is functionally and stratigraphically distinct from the Holocene
Human activity is leaving a pervasive and persistent signature on Earth. Vigorous debate continues about whether this warrants recognition as a new geologic time unit known as the Anthropocene. We review anthropogenic markers of functional changes in the Earth system through the stratigraphic record. The appearance of manufactured materials in sediments â including aluminum, plastics and concrete â coincides with global spikes in fallout radionuclides and particulates from fossil-fuel combustion. Carbon, nitrogen, and phosphorus cycles have been substantially modified over the last century. Rates of sea-level rise, and the extent of human perturbation of the climate system, exceed Late Holocene changes. Biotic changes include species invasions worldwide and accelerating rates of extinction. These combined signals render the Anthropocene stratigraphically distinct from the Holocene and earlier epochs
- âŠ