51 research outputs found
The Evolution of Compact Binary Star Systems
We review the formation and evolution of compact binary stars consisting of
white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and
BHs are thought to be the primary astrophysical sources of gravitational waves
(GWs) within the frequency band of ground-based detectors, while compact
binaries of WDs are important sources of GWs at lower frequencies to be covered
by space interferometers (LISA). Major uncertainties in the current
understanding of properties of NSs and BHs most relevant to the GW studies are
discussed, including the treatment of the natal kicks which compact stellar
remnants acquire during the core collapse of massive stars and the common
envelope phase of binary evolution. We discuss the coalescence rates of binary
NSs and BHs and prospects for their detections, the formation and evolution of
binary WDs and their observational manifestations. Special attention is given
to AM CVn-stars -- compact binaries in which the Roche lobe is filled by
another WD or a low-mass partially degenerate helium-star, as these stars are
thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure
Sex doll ownership: an agenda for research
Purpose of review: The topic of sex doll ownership is becoming an increasingly discussed issue from both a social and legal perspective. This review aims to examine the veracity of the existing psychological, sexological, and legal literature in relation to doll ownership.
Recent findings: Strong views exist across the spectrum of potential socio-legal positions on sex doll ownership. However, there is an almost total lack of empirical analyses of the psychological characteristics or behavioral implications of doll ownership. As such, existing arguments appear to represent the philosophical positions of those scholars expressing them, rather than being rooted in any objective evidence base.
Summary: Despite an absence of empirical data on the characteristics and subsequent effects of doll ownership, discussions about the ethical and legal status of doll ownership continue. This highlights a real and urgent need for a coherent research agenda to be advanced in this area of work
Pyruvate: immunonutritional effects on neutrophil intracellular amino or alpha-keto acid profiles and reactive oxygen species production
For the first time the immunonutritional role of pyruvate on neutrophils (PMN), free α-keto and amino acid profiles, important reactive oxygen species (ROS) produced [superoxide anion (O2−), hydrogen peroxide (H2O2)] as well as released myeloperoxidase (MPO) acitivity has been investigated. Exogenous pyruvate significantly increased PMN pyruvate, α-ketoglutarate, asparagine, glutamine, aspartate, glutamate, arginine, citrulline, alanine, glycine and serine in a dose as well as duration of exposure dependent manner. Moreover, increases in O2− formation, H2O2-generation and MPO acitivity in parallel with intracellular pyruvate changes have also been detected. Regarding the interesting findings presented here we believe, that pyruvate fulfils considerably the criteria for a potent immunonutritional molecule in the regulation of the PMN dynamic α-keto and amino acid pools. Moreover it also plays an important role in parallel modulation of the granulocyte-dependent innate immune regulation. Although further research is necessary to clarify pyruvate’s sole therapeutical role in critically ill patients’ immunonutrition, the first scientific successes seem to be very promising
The First Molecular Phylogeny of Strepsiptera (Insecta) Reveals an Early Burst of Molecular Evolution Correlated with the Transition to Endoparasitism
A comprehensive model of evolution requires an understanding of the relationship between selection at the molecular and phenotypic level. We investigate this in Strepsiptera, an order of endoparasitic insects whose evolutionary biology is poorly studied. We present the first molecular phylogeny of Strepsiptera, and use this as a framework to investigate the association between parasitism and molecular evolution. We find evidence of a significant burst in the rate of molecular evolution in the early history of Strepsiptera. The evolution of morphological traits linked to parasitism is significantly correlated with the pattern in molecular rate. The correlated burst in genotypic-phenotypic evolution precedes the main phase of strepsipteran diversification, which is characterised by the return to a low and even molecular rate, and a period of relative morphological stability. These findings suggest that the transition to endoparasitism led to relaxation of selective constraint in the strepsipteran genome. Our results indicate that a parasitic lifestyle can affect the rate of molecular evolution, although other causal life-history traits correlated with parasitism may also play an important role
Bacterial communities in termite fungus combs are comprised of consistent gut deposits and contributions from the environment
Defective DNA repair and chromatin organization in patients with quiescent systemic lupus erythematosus
Right ventricular outflow tract assessment by cross-sectional echocardiography in tetralogy of Fallot.
Structure and conservation of Sri Lankan land-snail assemblages in fragmented lowland rainforest and village home gardens
1.
Modified habitats have a profound impact on the biota of fragmented tropical forests. We
investigated the structure of land-snail assemblages in Sri Lankan lowland rainforest and village
home gardens, a habitat of the surrounding matrix of modified habitats. We focused on four questions,
(i) How do the land-snail faunas of lowland rainforest and home gardens differ and can forest
species persist in gardens? (ii) Can environmental variables such as altitude, canopy density and soil
pH explain significant variation in species composition independent of the effects of habitat type?
(iii) What is the extent of geographical species turnover? (iv) How valuable are the two habitats for
the conservation of native land snails?
2.
Sixty-nine standardized belt transects were sampled in 21 rainforest fragments and 12 gardens.
Data were analysed using canonical and partial canonical correspondence analysis.
3.
Land-snail species composition varied significantly between gardens and forest. Lowland rainforest
was dominated by native snails, many of which were restricted to forest. Gardens contained a
distinct component of exotic and native synanthropic snails, as well as many native forest species.
Altitude, canopy density and soil pH explained significant variation in species composition independent
of the effects of habitat type but were closely correlated with variation in species composition
between gardens and forest. Longitude and latitude explained significant variation in species
composition across both gardens and forest.
4.
Synthesis and applications
. Most rainforest snails were restricted to forest. This, together with
the high level of geographical turnover and the scale of forest fragmentation, emphasizes the need
to conserve all remaining rainforest cover. A substantial number of widespread and localized forest
land-snail species can survive in gardens. Home gardens therefore offer great potential for restoring
and increasing forest cover and connectivity
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