1,206 research outputs found
Genetic Stratigraphy of Key Demographic Events in Arabia
The issue of admixture in human populations is normally addressed by genome-wide (GW) studies, and several approaches have been developed to date admixture events [1,2,3,4,5]. Admixed populations bear chromosomes with segments of DNA from all contributing source groups, the size of which decreases over successive generations until recombination renders them undetectably short. Several algorithms attempt to date admixture events by inferring the size of the nuclear ancestry segments, and these can work well when dating recent episodes in human history, such as the sub-Saharan African input into the New World [6], but they fail to detect several known episodes that took place at earlier times, such as the African input into Iberia [1] and genetic exchanges across the Red Sea [7]. Simulations with the suite of methods available at the ADMIXTOOLS package indicated that these methods could detect admixture events as early as 500 generation ago, but real data did not allow the tracing of such old events [8]. A recent improved algorithm, called GLOBETROTTER, has been used to tackle the detection of the co-occurrence of several mixture events by decomposing each chromosome into a series of haplotypic chunks and then analysing each chunk independently [3], but the problem of detecting ancient events remains. Its application to the systematic screening of worldwide admixture events was able to reveal around 100 events, but all occurring over only the past 4,000 years [3
Galaxy cluster mergers as triggers for the formation of jellyfish galaxies: case study of the A901/2 system
The A901/2 system is a rare case of galaxy cluster interaction, in which two
galaxy clusters and two smaller groups are seen in route of collision with each
other simultaneously. Within each of the four substructures, several galaxies
with features indicative of jellyfish morphologies have been observed. In this
paper, we propose a hydrodynamic model for the merger as a whole, compatible
with its diffuse X-ray emission, and correlate the gas properties in this model
with the locations of the jellyfish galaxy candidates in the real system. We
find that jellyfish galaxies seem to be preferentially located near a boundary
inside each subcluster where diffuse gas moving along with the subcluster and
diffuse gas from the remainder of the system meet. The velocity change in those
boundaries is such that a factor of up to 1000 increase in the ram
pressure takes place within a few hundred kpc, which could trigger the high
rate of gas loss necessary for a jellyfish morphology to emerge. A theoretical
treatment of ram pressure stripping in the environment of galaxy cluster
mergers has not been presented in the literature so far; we propose that this
could be a common scenario for the formation of jellyfish morphologies in such
systems.Comment: Accepted for publication in MNRAS. 10 pages, 9 figure
Insuficiência renal aguda secundária à sÃndrome compartimental abdominal: relato de quatro casos e revisão da literatura
We report on 4 cases of abdominal compartment syndrome complicated by acute renal failure that were promptly reversed by different abdominal decompression methods. Case 1: A 57-year-old obese woman in the post-operative period after giant incisional hernia correction with an intra-abdominal pressure of 24 mm Hg. She was sedated and curarized, and the intra-abdominal pressure fell to 15 mm Hg. Case 2: A 73-year-old woman with acute inflammatory abdomen was undergoing exploratory laparotomy when a hypertensive pneumoperitoneum was noticed. During the surgery, enhancement of urinary output was observed. Case 3: An 18-year-old man who underwent hepatectomy and developed coagulopathy and hepatic bleeding that required abdominal packing, developed oliguria with a transvesical intra-abdominal pressure of 22 mm Hg. During reoperation, the compresses were removed with a prompt improvement in urinary flow. Case 4: A 46-year-old man with hepatic cirrhosis was admitted after incisional hernia repair with intra-abdominal pressure of 16 mm Hg. After paracentesis, the intra-abdominal pressure fell to 11 mm Hg.Descrevemos quatro casos de sÃndrome compartimental abdominal complicadas por insuficiência renal aguda e prontamente revertidas por diferentes métodos de descompressão abdominal. Caso 1: paciente obesa de 57 anos no pós-operatório de correção de hérnia incisional gigante com pressão intra-abdominal de 24 mm Hg. Após sedação e curarização, a PIA caiu para 15 mm Hg. Caso 2: paciente de 73 anos com abdômem agudo inflamatório submetida à laparotomia exploradora quando foi diagnosticado pneumoperitôneo hipertensivo. Durante a cirurgia houve melhora da diurese. Caso 3: paciente de 18 anos submetido a hepactetomia apresentou coagulopatia e sangramento hepático necessitando tamponamento com compressas, evoluindo com oligúria e PIA de 22 mm Hg. Na reoperação, após remoção das compressas houve melhora importante do fluxo urinário. Caso 4: paciente de 46 anos com cirrose hepática foi admitido após correção de hérnia incisional com pressão intra-abdominal de 16 mm Hg. Após paracentese, a pressão intra-abdominal caiu para 11 mm Hg
Complex Network Tools to Understand the Behavior of Criminality in Urban Areas
Complex networks are nowadays employed in several applications. Modeling
urban street networks is one of them, and in particular to analyze criminal
aspects of a city. Several research groups have focused on such application,
but until now, there is a lack of a well-defined methodology for employing
complex networks in a whole crime analysis process, i.e. from data preparation
to a deep analysis of criminal communities. Furthermore, the "toolset"
available for those works is not complete enough, also lacking techniques to
maintain up-to-date, complete crime datasets and proper assessment measures. In
this sense, we propose a threefold methodology for employing complex networks
in the detection of highly criminal areas within a city. Our methodology
comprises three tasks: (i) Mapping of Urban Crimes; (ii) Criminal Community
Identification; and (iii) Crime Analysis. Moreover, it provides a proper set of
assessment measures for analyzing intrinsic criminality of communities,
especially when considering different crime types. We show our methodology by
applying it to a real crime dataset from the city of San Francisco - CA, USA.
The results confirm its effectiveness to identify and analyze high criminality
areas within a city. Hence, our contributions provide a basis for further
developments on complex networks applied to crime analysis.Comment: 7 pages, 2 figures, 14th International Conference on Information
Technology : New Generation
Relações hospedeiro-parasita
Num ecossistema, é possÃvel encontrar diversas relações entre os seres vivos aà presentes, incluindo relações em que um organismo é beneficiado à s custas de outro. No caso das relações hospedeiro-parasita, verifica-se uma associação muito forte entre os dois organismos, sendo que os parasitas desempenham um papel ecológico e evolutivo muito relevante.Este trabalho foi financiado por fundos nacionais (através da Fundação para a Ciência e a Tecnologia) e
pelo Fundo Europeu de Desenvolvimento Regional (através dos programas COMPETE2020 e PT2020)
através do projeto de investigação FunG-Eye (POCI-01-0145-FEDER-029505)
A via receptor NMDA-óxido nÃtrico-GMP cÃclico como alvo para o desenvolvimento de medicações antipsicóticas não-dopaminérgicas para a esquizofrenia
Simulation Mechanism with 2 Degrees of Freedom
This article discusses the historical analysis of the development of simulators applied to aviation. From the development with the application of the first necessity, at the beginning of the 20th century, to the nowadays technology. Today the technology is used in several fields, justifying the increasing business investment destined to the sector, such as training, recycling, development and entertainment. Its advantage, compared to the real model, is the lower cost and greater security. Some simulator mechanisms were studied in order to select one that meets practical USAge demands, and, in the end, a mechanism design is presented, aiming at the future construction and study of the different systems of a simulator in practice
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