165 research outputs found
The Effect of Retinoids on the Regenerating Axolotl Spinal Cord
In order to further elucidate the mechanics of the retinoid pathway on Urodele spinal cord regeneration, we employed Antibody/Horseradish Peroxidase Staining of both intact and regenerating Axolotl spinal cord tissues obtained from adult and juvenile animals to determine expression of two retinoid pathway components: Cellular Retinoic Acid Binding Protein II (CRABP II) and Cellular Retinol Binding Protein I (CRBP I). Current results demonstrate that CRABP II is heavily expressed in the arachnoid mater meningeal layer; CRPB I, however, is expressed in the following locations: the pia mater meningeal layer, the nuclei and cytoplasm of gray matter neuroblasts, as well as processes derived from neuroblasts and ependyma. Moreover, the morphogenic nature of the retinoids may possess a significant role in the regeneration-permissive interaction of the meninges and ependyma of the Axolotl spinal cord
Cardiovascular abnormalities in patients with oral cleft: a clinical-electrocardiographic-echocardiographic study
OBJECTIVES: The present study aims to describe the clinical, electrocardiographic, and echocardiographic cardiological findings in a group of patients with oral clefts. METHODS: This is a prospective cross-sectional study on 70 children (age range from 13 days to 19 years) with oral clefts who attended the multidisciplinary program of a university hospital from March 2013 to September 2014. The patients were evaluated by a pediatric cardiologist and underwent detailed anamnesis, physical examination, electrocardiogram, and echocardiogram. RESULTS: Sixty percent of the patients were male; 55.7% presented with cleft lip and palate, and 40.0% presented with health complaints. Comorbidities were found in 44.3%. Relevant pregnancy, neonatal, family and personal antecedents were present in 55.7%, 27.1%, 67.2%, and 24.3% of the patients, respectively. Regarding the antecedents, 15.2% of the patients presented with a cardiac murmur, 49.0% with a familial risk of developing plurimetabolic syndrome, and 6% with family antecedents of rheumatic fever. Electrocardiographic evaluation showed one case of atrioventricular block. Echocardiograms were abnormal in 35.7% of the exams, including 5 cases of mitral valve prolapse — one of which was diagnosed with rheumatic heart disease. CONCLUSION: The finding of a family risk of developing plurimetabolic syndrome and a diagnosis of rheumatic heart disease indicates that patients with oral clefts may be more prone to developing acquired heart disease. Thus, our findings highlight the importance of anamnesis and methodological triangulation (clinical-electrocardiographic-echocardiographic) in the investigation of patients with oral clefts and emphasize that cardiological follow-up to evaluate acquired and/or rhythm heart diseases is necessary. This strategy permits comorbidity prevention and individualized planned treatment
Technological level and epidemiological aspects of sheep husbandry in Minas Gerais, southeastern Brazil
Interactions between an arbuscular mycorrhizal fungus (Scutellospora heterogama) and the root-knot nematode (Meloidogyne incognita) on sweet passion fruit (Passiflora alata)
Temporal evolution of solar energetic particle spectra
During solar flares and coronal mass ejections, solar energetic par- ticles (SEPs) may be released into the interplanetary medium and near-Earth locations. The energy spectra of SEP events at 1 AU are typically averaged over the entire event or studied in a few snapshots. In this paper we analyze the time evolution of the energy spectra of four large selected SEP events using a large number of snapshots. We use a multi-spacecraft and multi-instrument approach for the observations, obtained over a wide SEP energy range. We find large differences in the spectra at the beginning of the events as measured by different instruments. We show that over time, a wave-like structure is observed traveling through the spectra from the highest energies to the lowest energies, creating an “arch” shape which then straightens into a power law later in the event, after times of the order of 10 hours. We discuss the processes that determine SEP intensities and their role in shaping the spectral time evolution
Bianchi {VI} in Scalar and Scalar-Tensor Cosmologies
We study several cosmological models with Bianchi \textrm{VI}
symmetries under the self-similar approach. In order to study how the
\textquotedblleft constants\textquotedblright\ and may vary, we
propose three scenarios where such constants are considered as time functions.
The first model is a perfect fluid. We find that the behavior of and
are related. If behaves as a growing time function then
is a positive decreasing time function but if is decreasing then
is negative. For this model we have found a new solution. The second model is a
scalar field, where in a phenomenological way, we consider a modification of
the Klein-Gordon equation in order to take into account the variation of .
Our third scenario is a scalar-tensor model. We find three solutions for this
models where is growing, constant or decreasing and is a positive
decreasing function or vanishes. We put special emphasis on calculating the
curvature invariants in order to see if the solutions isotropize.Comment: Typos corrected. References added, minor corrections. arXiv admin
note: text overlap with arXiv:0905.247
DES15E2mlf: a spectroscopically confirmed superluminous supernova that exploded 3.5 Gyr after the big bang
We present the Dark Energy Survey (DES) discovery of DES15E2mlf, the most distant superluminous supernova (SLSN) spectroscopically confirmed to date. The light curves and Gemini spectroscopy of DES15E2mlf indicate that it is a Type I superluminous supernova (SLSN-I) at z = 1.861 (a lookback time of ∼10 Gyr) and peaking at MAB = −22.3 ± 0.1 mag. Given the high redshift, our data probe the rest-frame ultraviolet (1400–3500 Å) properties of the SN, finding velocity of the C III feature changes by ∼5600 km s−1 over 14 d around maximum light. We find the host galaxy of DES15E2mlf has a stellar mass of 3.5+3.6 −2.4 × 109 M, which is more massive than the typical SLSN-I host galaxy
Técnica de valoração econômica de ações de requalificação do meio ambiente: aplicação em área degradada
Superluminous supernovae from the Dark Energy Survey
We present a sample of 21 hydrogen-free superluminous supernovae (SLSNe-I) and one hydrogen-rich SLSN (SLSN-II) detected during the five-year Dark Energy Survey (DES). These SNe, located in the redshift range 0.220 < z < 1.998, represent the largest homogeneously selected sample of SLSN events at high redshift. We present the observed g, r, i, z light curves for these SNe, which we interpolate using Gaussian processes. The resulting light curves are analysed to determine the luminosity function of SLSNe-I, and their evolutionary timescales. The DES SLSN-I sample significantly broadens the distribution of SLSN-I light-curve properties when combined with existing samples from the literature. We fit a magnetar model to our SLSNe, and find that this model alone is unable to replicate the behaviour of many of the bolometric light curves. We search the DES SLSN-I light curves for the presence of initial peaks prior to the main light-curve peak. Using a shock breakout model, our Monte Carlo search finds that 3 of our 14 events with pre-max data display such initial peaks. However, 10 events show no evidence for such peaks, in some cases down to an absolute magnitude of<−16, suggesting that such features are not ubiquitous to all SLSN-I events. We also identify a red pre-peak feature within the light curve of one SLSN, which is comparable to that observed within SN2018bsz
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