Search results for "Dwarf"

Estimating the dwarfing rate of an extinct Sicilian elephant.

2021

Summary Evolution on islands, together with the often extreme phenotypic changes associated with it, has attracted much interest from evolutionary biologists. However, measuring the rate of change of phenotypic traits of extinct animals can be challenging, in part due to the incompleteness of the fossil record. Here, we use combined molecular and fossil evidence to define the minimum and maximum rate of dwarfing in an extinct Mediterranean dwarf elephant from Puntali Cave (Sicily). 1 Despite the challenges associated with recovering ancient DNA from warm climates, 2 we successfully retrieved a mitogenome from a sample with an estimated age between 175,500 and 50,000 years. Our results sugge…

H-He collision-induced satellite in the Lyman alpha profile of DBA white dwarf stars

2020

The spectra of helium-dominated white dwarf stars with hydrogen in their atmosphere present a distinctive broad feature centered around 1160~\AA\/ in the blue wing of the Lyman-$\alpha$ line. It is extremely apparent in WD 1425+540 recently observed with HST COS. With new theoretical line profiles based on ab initio atomic interaction potentials we show that this feature is a signature of a collision-induced satellite due to an asymptotically forbidden transition. This quasi-molecular spectral satellite is crucial to understanding the asymmetrical shape of Lyman-$\alpha$ seen in this and other white dwarf spectra. Our previous work predicting this absorption feature was limited by molecular…

X-shooter spectroscopy of young stars with disks. The TW Hydrae association as a probe of the final stages of disk accretion

2019

We investigate ongoing accretion activity in young stars in the TW Hydrae association (TWA, ~8-10 Myr), an ideal target to probe the final stages of disk accretion down to brown dwarf masses. Our sample comprises eleven TWA members with infrared excess, amounting to 85% of the total TWA population with disks, with spectral types between M0 and M9, and masses between 0.58 and 0.02 Msol. We employed homogeneous spectroscopic data from 300 to 2500 nm, obtained with X-shooter, to derive individual extinction, stellar parameters, and accretion parameters simultaneously. We then examined Balmer lines and forbidden emission lines to probe the physics of the star-disk interaction environment. We de…

The visceral adiposity index is associated with insulin sensitivity and IGF-I levels in adults with growth hormone deficiency

2016

The visceral adiposity index, based on anthropometric and metabolic parameters, has been shown to be related to adipose tissue function and insulin sensitivity. We aimed to evaluate the performance of the visceral adiposity index in adult patients with growth hormone deficiency. We enrolled 52 patients(mean age 51 ± 13 years) with newly diagnosed growth hormone deficiency and 50 matched healthy subjects as controls at baseline. At baseline and after 12 and 24 months of treatment we evaluated anthropometric measures, lipid profile, glucose and insulin during an oral glucose tolerance test, hemoglobin A1c, homeostasis model assessment estimate of insulin resistance, quantitative insulin sensi…

HETEROGENEITY OF METATROPIC DYSPLASIA

1983

Metatropic dysplasia is a neonatally manifest entity that is characterized clinically by a rapidly progressing kyphoscoliosis leading to severe shortening of the originally long trunk ("metatropism"). Major radiographic features include flattening and defective ossification of the vertebral bodies, a narrow thorax and a marked hypoplasia of the basilar portions of the ilia with crescent-shaped iliac crests. There is some evidence of genetic heterogeneity. From five personal observations and from a review of the literature we conclude that metatropic dysplasia comprises at least three genetic entities: (1) a nonlethal type with autosomal recessive transmission; (2) a nonlethal dominant type …

Gender-, age- and time-dependent dosing of growth hormone in adults - real-world data from a decade of clinical practice in Germany.

2017

We evaluated treatment patterns and gender-dependent dosing of growth hormone (GH) substitution in adults with GH deficiency (AGHD). Data on GH dose were collected (2003-2013) from 509 GH-treated patients (mean age: 48.9 years; 47% female) enroled in the observational German NordiWin study (NCT01543880). The impact of gender, age, treatment duration and calendar year on GH treatment patterns was evaluated by multiple regression analysis. Mean (SD) baseline GH dose (mg/day) was similar between females (0.25 [0.19] and males (0.24 [0.15]), but increased with treatment duration (at year 10, 0.55 [0.48] and 0.31 [0.09] in females and males, respectively), reflecting patient dose titration. GH d…

Electrophoretic study on two morphologically distinguishable populations of Paracentrotus lividus (Echinodermata) from distinct areas of the mediterr…

1998

Heterochronic differentiation of sexual dimorphs among Jurassic ammonite species

1997

Ontogenetic and then heterochronic approaches are used here to analyze sexual differentiation within two well-known Jurassic dimorphic species. This analysis compares two ways of determining the relative biological age of ammonites, one using size (diameter) and the other the number of septa as a proxy of age. The shape standard is established from factor analysis of morphological and growth parameters. Size-age-shape relationships are analyzed on the basis of a new heterochronic representation. When diameter is used as a proxy of age, microconch morphs are globally considered to be progenetic compared with macroconch morphs. When size and age are determined separately and shape is included…

Astrophysics with the Laser Interferometer Space Antenna

2023

Full list of authors: Amaro-Seoane, Pau; Andrews, Jeff; Sedda, Manuel Arca; Askar, Abbas.; Baghi, Quentin; Balasov, Razvan; Bartos, Imre; Bavera, Simone S.; Bellovary, Jillian; Berry, Christopher P. L.; Berti, Emanuele; Bianchi, Stefano; Blecha, Laura; Blondin, Stephane; Bogdanovic, Tamara; Boissier, Samuel; Bonetti, Matteo; Bonoli, Silvia; Bortolas, Elisa; Breivik, Katelyn; Capelo, Pedro R.; Caramete, Laurentiu; Cattorini, Federico; Charisi, Maria; Chaty, Sylvain; Chen, Xian; Chruslinska, Martyna; Chua, Alvin J. K.; Church, Ross; Colpi, Monica; D'Orazio, Daniel; Danielski, Camilla; Davies, Melvyn B.; Dayal, Pratika; De Rosa, Alessandra; Derdzinski, Andrea; Destounis, Kyriakos; Dotti, Massi…

A White Paper on keV sterile neutrino Dark Matter

2017

We present a comprehensive review of keV-scale sterile neutrino Dark Matter, collecting views and insights from all disciplines involved - cosmology, astrophysics, nuclear, and particle physics - in each case viewed from both theoretical and experimental/observational perspectives. After reviewing the role of active neutrinos in particle physics, astrophysics, and cosmology, we focus on sterile neutrinos in the context of the Dark Matter puzzle. Here, we first review the physics motivation for sterile neutrino Dark Matter, based on challenges and tensions in purely cold Dark Matter scenarios. We then round out the discussion by critically summarizing all known constraints on sterile neutrin…