150 research outputs found
Population differences in allele frequencies at the OLR1 locus may suggest geographic disparities in cardiovascular risk events.
Abstract
Background: Several studies have demonstrated a link between cardiovascular disease (CVD) susceptibility
and the genetic background of populations.
Endothelial activation and dysfunction induced by oxidized low-density lipoprotein (ox-LDL) is one of
the key steps in the initiation of atherosclerosis. The oxidized low density lipoprotein (lectin-like)
receptor 1 (OLR1) gene is the main receptor of ox-LDL. We have previously characterized two
polymorphisms (rs3736235 and rs11053646) associated with the risk for coronary artery disease
(CAD) and acute myocardial infarction (AMI).
Aim: Given their clinical significance, it is of interest to know the distribution of these variants in
populations from different continents.
Subjects and methods: A total of 1229 individuals from 17 different African, Asian and European
populations was genotyped for the two considered markers.
Results: The high frequencies of ancestral alleles in South-Saharan populations is concordant with the
African origin of our species. The results highlight that African populations are closer to Asians, and
clearly separated from the Europeans.
Conclusion: The results confirm significant genetic structuring among populations and suggest a
possible basis for varying susceptibility to CVD among groups correlated with the geographical
location of populations linked with the migrations out of Africa, or with different lifestyle
Application of microbial fuel cell technology for vinasse treatment and bioelectricity generation
Our study evaluated the performance of different two-chambered microbial fuel cell (MFC) prototypes, operated with variable distance between electrodes and Nafion membrane and specific inoculum concentration, applied for vinasse treatment.Instituto de Pesquisa Tecnológica do Estado de São Paulo/Programa Novos Talentos, through individual Research Grant attributed to Cristiane Angélica Ottoni.info:eu-repo/semantics/publishedVersio
Implicit Regularization and Renormalization of QCD
We apply the Implicit Regularization Technique (IR) in a non-abelian gauge
theory. We show that IR preserves gauge symmetry as encoded in relations
between the renormalizations constants required by the Slavnov-Taylor
identities at the one loop level of QCD. Moreover, we show that the technique
handles divergencies in massive and massless QFT on equal footing.Comment: (11 pages, 2 figures
Uniparental Genetic Heritage of Belarusians: Encounter of Rare Middle Eastern Matrilineages with a Central European Mitochondrial DNA Pool
Ethnic Belarusians make up more than 80% of the nine and half million people inhabiting the Republic of Belarus. Belarusians together with Ukrainians and Russians represent the East Slavic linguistic group, largest both in numbers and territory, inhabiting East Europe alongside Baltic-, Finno-Permic- and Turkic-speaking people. Till date, only a limited number of low resolution genetic studies have been performed on this population. Therefore, with the phylogeographic analysis of 565 Y-chromosomes and 267 mitochondrial DNAs from six well covered geographic sub-regions of Belarus we strove to complement the existing genetic profile of eastern Europeans. Our results reveal that around 80% of the paternal Belarusian gene pool is composed of R1a, I2a and N1c Y-chromosome haplogroups â a profile which is very similar to the two other eastern European populations â Ukrainians and Russians. The maternal Belarusian gene pool encompasses a full range of West Eurasian haplogroups and agrees well with the genetic structure of central-east European populations. Our data attest that latitudinal gradients characterize the variation of the uniparentally transmitted gene pools of modern Belarusians. In particular, the Y-chromosome reflects movements of people in central-east Europe, starting probably as early as the beginning of the Holocene. Furthermore, the matrilineal legacy of Belarusians retains two rare mitochondrial DNA haplogroups, N1a3 and N3, whose phylogeographies were explored in detail after de novo sequencing of 20 and 13 complete mitogenomes, respectively, from all over Eurasia. Our phylogeographic analyses reveal that two mitochondrial DNA lineages, N3 and N1a3, both of Middle Eastern origin, might mark distinct events of matrilineal gene flow to Europe: during the mid-Holocene period and around the Pleistocene-Holocene transition, respectively
Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) VIII. Nondetection of sodium in the atmosphere of the aligned planet KELT-10b
We searched for potential atmospheric species in KELT-10b, focusing on sodium
doublet lines (Na i; 589 nm) and the Balmer alpha line (H ; 656 nm) in
the transmission spectrum. Furthermore, we measured the planet-orbital
alignment with the spin of its host star. We used the Rossiter-McLaughlin
Revolutions technique to analyze the local stellar lines occulted by the planet
during its transit. We used the standard transmission spectroscopy method to
probe the planetary atmosphere, including the correction for telluric lines and
the Rossiter-McLaughlin effect on the spectra. We analyzed two new light curves
jointly with the public photometry observations. We do not detect signals in
the Na i and H lines within the uncertainty of our measurements. We
derive the 3-sigma upper limit of excess absorption due to the planetary
atmosphere corresponding to equivalent height Rp to 1.8Rp (Na i) and 1.9Rp (H
). The analysis of the Rossiter-McLaughlin effect yields the
sky-projected spin-orbit angle of the system = -5.2 3.4 and the
stellar projected equatorial velocity = 2.58 0.12
km/s. Photometry results are compatible within 1 -sigma with previous studies.
We found no evidence of Na i and H , within the precision of our data,
in the atmosphere of KELT-10b. Our detection limits allow us to rule out the
presence of neutral sodium or excited hydrogen in an escaping extended
atmosphere around KELT-10b. We cannot confirm the previous detection of Na i at
lower altitudes with VLT/UVES. We note, however, that the Rossiter-McLaughlin
effect impacts the transmission spectrum on a smaller scale than the previous
detection with UVES. Analysis of the planet-occulted stellar lines shows the
sky-projected alignment of the system, which is likely truly aligned due to
tidal interactions of the planet with its cool (Teff < 6250 K) host star.Comment: Accepted in A&
TOI-858 B b: A hot Jupiter on a polar orbit in a loose binary
We report the discovery of a hot Jupiter on a 3.28-day orbit around a 1.08
M G0 star that is the secondary component in a loose binary system.
Based on follow-up radial velocity observations of TOI-858 B with CORALIE on
the Swiss 1.2 m telescope and CHIRON on the 1.5 m telescope at the Cerro Tololo
Inter-American Observatory (CTIO), we measured the planet mass to be M . Two transits were further observed with CORALIE to determine
the alignment of TOI-858 B b with respect to its host star. Analysis of the
Rossiter-McLaughlin signal from the planet shows that the sky-projected
obliquity is . Numerical simulations show that the
neighbour star TOI-858 A is too distant to have trapped the planet in a
Kozai-Lidov resonance, suggesting a different dynamical evolution or a
primordial origin to explain this misalignment. The 1.15 Msun primary F9 star
of the system (TYC 8501-01597-1, at ~11") was also observed with CORALIE
in order to provide upper limits for the presence of a planetary companion
orbiting that star.Comment: Accepted for publication in A&
Sail or sink: novel behavioural adaptations on water in aerially dispersing species
Background
Long-distance dispersal events have the potential to shape species distributions and ecosystem diversity over large spatial scales, and to influence processes such as population persistence and the pace and scale of invasion. How such dispersal strategies have evolved and are maintained within species is, however, often unclear. We have studied long-distance dispersal in a range of pest-controlling terrestrial spiders that are important predators within agricultural ecosystems. These species persist in heterogeneous environments through their ability to re-colonise vacant habitat by repeated long-distance aerial dispersal (âballooningâ) using spun silk lines. Individuals are strictly terrestrial, are not thought to tolerate landing on water, and have no control over where they land once airborne. Their tendency to spread via aerial dispersal has thus been thought to be limited by the costs of encountering water, which is a frequent hazard in the landscape.
Results
In our study we find that ballooning in a subset of individuals from two groups of widely-distributed and phylogenetically distinct terrestrial spiders (linyphiids and one tetragnathid) is associated with a hitherto undescribed ability of those same individuals to survive encounters with both fresh and marine water. Individuals that showed a high tendency to adopt âballooningâ behaviour adopted elaborate postures to seemingly take advantage of the wind current whilst on the water surface.
Conclusions
The ability of individuals capable of long-distance aerial dispersal to survive encounters with water allows them to disperse repeatedly, thereby increasing the pace and spatial scale over which they can spread and subsequently exert an influence on the ecosystems into which they migrate. The potential for genetic connectivity between populations, which can influence the rate of localized adaptation, thus exists over much larger geographic scales than previously thought. Newly available habitat may be particularly influenced given the degree of ecosystem disturbance that is known to follow new predator introductions
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