1,797 research outputs found
Transcriptome of the deep-sea black scabbardfish, Aphanopus carbo (Perciformes: Trichiuridae) : tissue-specific expression patterns and candidate genes associated to depth adaptation
Deep-sea fishes provide a unique opportunity to study the physiology and evolutionary adaptation to extreme environments. We carried out a high throughput sequencing analysis on a 454 GS-FLX titanium plate using unnormalized cDNA libraries from six tissues of A. carbo. Assemblage and annotations were performed by Newbler and InterPro/Pfam analyses, respectively. The assembly of 544,491 high quality reads provided 8,319 contigs, 55.6% of which retrieved blast hits against the NCBI nonredundant database or were annotated with ESTscan. Comparison of functional genes at both the protein sequences and protein stability levels, associated with adaptations to depth, revealed similarities between A. carbo and other bathypelagic fishes. A selection of putative genes was standardized to evaluate the correlation between number of contigs and their normalized expression, as determined by qPCR amplification. The screening of the libraries contributed to the identification of new EST simple-sequence repeats (SSRs) and to the design of primer pairs suitable for population genetic studies as well as for tagging and mapping of genes. The characterization of the deep-sea fish A. carbo first transcriptome is expected to provide abundant resources for genetic, evolutionary, and ecological studies of this species and the basis for further investigation of depth-related adaptation processes in fishes.Publisher PDFPeer reviewe
Evolution of Thermotolerance and Variation in the Heat Shock Protein, Hsp70
Low to moderate levels of stress induce a class of molecular chaperones called heat shock proteins (Hsps), which protect cells, tissues and whole organisms from more severe stress. In higher Eukaryotes, Hsp70 is one of the principle heat-induced chaperones. This response is general, and how much Hsp70 an animal produces correlates with the level of stress to which it is exposed. Nonetheless, definitively linking high Hsp70 expression as an adaptation to stress tolerance is problematic, because organisms and cells respond to stress in many ways. By molecular manipulation of Hsp70 in one animal group, Drosophila, differences in hsp70 copy number are shown to directly influence heat-induced expression of Hsp70 and tolerance of heat. However, too high an expression level of Hsp70 can harm individuals during periods of rapid growth. This strong physiological relationship between Hsp70 concentration and thermotolerance, along with Hsp70\u27s remarkable degree of interspecific coding sequence conservation, suggest that hsp70 regulatory elements may evolve as an adaptation in diverse species to their thermal environments. To examine this possibility, correlative studies within species and research on phylogenetic covariation between these traits is reviewed with a focus on Drosophila species. However, the techniques and results discussed should broadly apply to other animal groups where evolutionary approaches can be used to test whether genetic variation in both thermotolerance and Hsp expression within and among species select locally on either hsp70 sequence and/or expression
Exames androlĂłgicos em bovinos de carne na regiĂŁo do Alentejo, Portugal#
É referida a importância do exame andrológico em bovinos explorados em regime extensivo e como este serviço médico-veterinário tem vindo a ser oferecido em Portugal. Descrevem-se os resultados encontrados por uma equipa médico-veterinária em contexto prático na região do Alentejo e discute-se como podem ser avaliados estes resultados com critérios o mais objectivo possiveis para selecção dos melhores touros
Interaction between vortices in models with two order parameters
The interaction energy and force between widely separated strings is analyzed
in a field theory having applications to superconducting cosmic strings, the
SO(5) model of high-temperature superconductivity, and solitons in nonlinear
optics. The field theory has two order parameters, one of which is broken in
the vacuum (giving rise to strings), the other of which is unbroken in the
vacuum but which could nonetheless be broken in the core of the string. If this
does occur, there is an effect on the energetics of widely separated strings.
This effect is important if the length scale of this second order parameter is
longer than that of the other fields in the problem.Comment: 11 pages, 3 figures. Minor changes in the text. Accepted for
publication in Phys. Rev.
Semi-automatic quantification of the epicardial fat in CT images
In this work we present a technique to automatically or semi-automatically quantify the epicardial fat in noncontrasted Computed Tomography (CT) images. In CT images, the epicardial fat is very close to the pericardial fat, distincted only by the pericardium. The pericardium appears in the image as a very thin line, very hard to discriminate. To enhance the pericardium line and to remove noise as well as higher intensities due to calcifications, some pre-processing was applied, namely region growing, thresholding and average filtering techniques. To detect the pericardium line an algorithm was developed that considerer the heart anatomy to find control points belonging to that line. From the points detected an interpolation was done based on the cubic spline method. This method was also improved to avoid incorrect interpolation that occurs when one of the coordinates of the points is repeated. After having the line delineation, the pixels bellow the line were counted, considering only the pixels in the fat window (-190 to -30 Hounsfiel Units). In 10 images tested, in 4 the system fully automatically returned the correct value for epicardial fat. In the other 6 the system needed a small correction by moving 1 or 2 points to return the correct value of epicardial fat. The values of the automatic quantification were compared to the values obtained by the manual process, having 10% as maximum error allowed. We concluded that this method is able to, automatically or with a small interaction, return the value of the epicardial fat, for the non contrast CT images tested
Winding Number Correlation Functions and Cosmic String Formation
We develop winding number correlation functions that allow us to assess the
role of field fluctuations on vortex formation in an Abelian gauge theory. We
compute the behavior of these correlation functions in simple circumstances and
show how fluctuations are important in the vicinity of the phase transition. We
further show that, in our approximation, the emerging population of
long/infinite string is produced by the classical dynamics of the fields alone,
being essentially unaffected by field fluctuations.Comment: Latex file, 27 pages. 8 figures, available in compressed form by
anonymous ftp from ftp://euclid.tp.ph.ic.ac.uk/papers/94-5_39.fig Latex and
postscript versions also available at
http://euclid.tp.ph.ic.ac.uk/Papers/index.htm
Diastolic Function Is Impaired in Patients With Prehypertension: Data From the EPIPorto Study
Introduction and objectives: Hypertension causes subclinical changes in left ventricular structure and function, namely diastolic dysfunction. Diastolic dysfunction is a predictor of heart failure, being involved in the association between hypertension and heart failure with preserved ejection fraction. We aimed to determine whether patients with prehypertension have early changes in diastolic function in a large community-based cohort of asymptomatic adults.
Methods: A cross-sectional evaluation was performed of a community-based cohort consisting of 925 adults, aged 45 years or older, without known cardiovascular disease. All participants underwent detailed clinical and echocardiographic examination. The participants were categorized according to the European guidelines for the classification of office blood pressure (BP) levels as optimal, prehypertensive (normal and high-normal categories), and hypertensive. Diastolic function was evaluated by echocardiography using e’ velocities and E/e’ ratio. Diastolic dysfunction was defined using the 2016 ASE/EACVI Joint Recommendations and a 2017 clinically-oriented algorithm.
Results: In this cohort (61.5 ± 10.5 years; 37% men), prehypertension was present in 30.4% and hypertension in 51.0%. Using optimal BP as the reference, there was a progressive decrease of e’ velocity in prehypertensive and hypertensive individuals (12.2 ± 3.5 vs 11.3 ± 3.1 vs 9.6 ± 2.9 cm/s, respectively; P for trend < .001). After multivariable adjustment, both BP categories were independent predictors of a lower e’ velocity (β = -0.56, P = .035 for prehypertension and β = –1.08, P < .001 for hypertension).
Conclusions: In this large community-based cohort, adults with prehypertension already showed impaired cardiac relaxation before the onset of hypertension
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