100,426 research outputs found
On the identity of Amphisbaena hugoi Vanzolini, 1990 (Reptilia: Squamata: Amphisbaenidae)
No full textThe taxonomic status of Amphisbaena hugoi Vanzolini, 1990, is discussed. It is concluded that it is a new junior synonym of Amphisbaena vanzolinii Gans, 1963.
O validade taxonômica de Amphisbaena hugoi é discutida. Conclue-se que A. hugoi Vanzolini, 1990, é
um sinônimo júnior de Amphisbaena vanzolinii Gans, 1963
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
MiR-126 and MiR-146a as Melatonin-Responsive Biomarkers for Neonatal Brain Ischemia
No full textNeonatal encephalopathy (NE) resulting from hypoxia-ischemia (HI) poses significant challenges, often leading to long-term neurological deficits. Therapeutic hypothermia is currently the standard treatment but has limitations, prompting research into adjunct therapies like melatonin.Melatonin shows promise due to its neuroprotective properties. However, optimal dosing and timing post-injury are unclear. NE diagnosis relies on clinical signs and neuroimaging, but early detection remains challenging.We aim to identify early biomarkers of brain injury post-HI by examining miRNAs. miR-126 and miR-146a show potential, as alterations in their levels correlate with brain injury severity and respond to melatonin treatment in preclinical models.This research underscores the importance of finding reliable biomarkers to aid in NE management and improve outcomes for affected infants. Matherials and methods Rat cerebral Hypoxic-Ischemia and melatonin treatment This study utilized a preclinical model of Rat Cerebral Hypoxic-Ischemia (HI) to investigate the effects of melatonin treatment on microRNA (miRNA) expression. Pregnant Sprague-Dawley rats underwent surgical procedures in accordance with animal care regulations. On postnatal day 7, neonatal rats underwent unilateral carotid artery ligation followed by exposure to hypoxia. Melatonin was administered intraperitoneally post-HI induction. Serum and brain samples were collected at various time points post-HI and melatonin treatment. Bioinformatics analysis and quantitativa real-time PCR for Mature miRNA analysis A bioinformatics analysis using the miRNet tool identified miR-126 and miR-146a as potential biomarkers associated with neonatal cerebral HI. Quantitative Real-Time PCR was employed to assess miRNA expression levels in serum and cerebral cortex homogenates. Results showed significant alterations in miR-126 and miR-146a expression post-HI, with melatonin treatment attenuating these changes. Overall, the study suggests that miR-126 and miR-146a may serve as early biomarkers of brain injury following neonatal HI, and their modulation by melatonin highlights the potential therapeutic benefits of melatonin in this context. Data analysis Statistical analyses were performed by two-way ANOVA or one-way ANOVA using the Prism Computer program (GraphPad Software Inc.). Bartlett’s test was used to determine data homogeneity. The Bonferroni multiple comparison test or Newman–Keuls multiple comparison test was used to determine differences between groups. Results were considered to be significant when p ≤0.05. Results In our study, we utilized the miRNet bioinformatics tool to analyze a new NCHI pathway sensitive to melatonin, predicting miR-126 and miR-146a as the most important associated miRNA nodes. Subsequently, we performed qRT-PCR analysis on cerebral cortex and serum samples collected from animals sacrificed at 1, 6, and 24 hours post-HI and melatonin treatment. In the cerebral cortex, miR-126 expression decreased 1 hour post-HI, increased at 6 hours, and decreased again at 24 hours. Melatonin treatment significantly increased miR-126 expression at 1 and 6 hours post-injury compared to controls, but levels were equivalent to HI animals at 24 hours. Conversely, serum miR-126 levels increased post-HI and decreased after melatonin treatment. Similarly, miR-146a showed a down-regulation at 1 hour post-HI, up-regulation at 6 hours, and return to control levels at 24 hours in the cerebral cortex. Melatonin treatment increased miR-146a levels compared to controls at all time points and compared to HI animals at 1 and 24 hours. Serum miR-146a levels increased post-HI, while melatonin treatment maintained levels similar to controls at 1 and 6 hours and increased levels at 24 hours compared to controls. Overall, our results suggest that melatonin treatment modulates miR-126 and miR-146a expression in both cerebral cortex and serum, potentially contributing to its neuroprotective effects in neonatal cerebral hypoxic-ischemic injury. Discussion and conclusion Neonatal mortality, constituting 46% of under-five mortality globally, is significantly impacted by neonatal encephalopathy (NE), a condition often stemming from hypoxic-ischemic (HI) injury. Rapid and accurate diagnosis is crucial for reducing mortality and morbidity associated with NE. While biomarker research shows promise, bottlenecks hinder their integration into clinical practice. MiRNAs, particularly brain-specific ones, have emerged as potential biomarkers due to their expression in both the brain and peripheral blood. Using bioinformatics tools, we identified miR-126 and miR-146a as potential biomarkers for perinatal brain injury, suggesting their utility in diagnosis. Through a neonatal rat model of HI brain injury, we observed dysregulation of miR-126 and miR-146a expression in both brain tissue and serum. Melatonin treatment post-HI showed restoration effects on these miRNAs, indicating its neuroprotective potential. MiR-126, crucial for vascular integrity and angiogenesis, exhibited down-regulation in cerebral cortex post-HI, with contrasting upregulation in serum. Melatonin treatment restored cortical levels while maintaining serum levels similar to controls. MiR-146a, a negative regulator of inflammation, showed a similar trend, with early down-regulation and subsequent upregulation post-HI in the cortex, and higher levels in serum post-HI, reduced by melatonin. These findings suggest miR-126 and miR-146a as potential diagnostic biomarkers for neonatal HI brain injury, with their dysregulation detectable within hours post-HI insult, aligning with the therapeutic window for intervention. While further clinical validation is necessary, these results offer insights for improving bedside clinical management in neonatal NE cases
Handwritten biographical information on Paulina T. McClung Merritt
No full textA handwritten biography of Paulina T. McClung Merritt by an unknown author, 1892.
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
No full textIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Pelevin’s Trinity in the novel “t”: author – protagonist – reader
No full textThe article attempts to interpret Pelevin's artistic strategy in the novel "T" by exploring its subject organization and addressing the key problems of the author, the protagonist, and the reader as they are seen by the researcher. The article analyzes the peculiarities of constructing the narrative reality in the novel "T", and goes on to discuss Pelevin's philosophic models of the development of the humankind, and the emergence of his new anthropology
Measuring industry-science links through inventor-author relations: A profiling method
No full textIn this pilot study we examine the performance of text-based profiling in recovering a set of validated inventor-author links. In a first step we match patents and publications solely based on their similarity in content. Next, we compare inventor and author names on the highest ranked matches for the occurrence of name matches. Finally, we compare these candidate matches with the names listed in a validated set of inventor-author names. Our text-based profile methodology performs significantly better than a random matching of patents and publications, suggesting that text-based profiling is a valuable complementary tool to the name searches used in previous studies.innovation; industry-science links; text-based profiling;
Wave turbulence of a rotating array of quantized vortices in the T → 0 temperature limit
No full textThe dynamics of quantized vortices in the zero temperature limit is currently of great interest, particularly in the case of the Fermi superfluid He-B. Here we study wave turbulence, generated by the librating motion of a rotating cylindrical container filled with He-B, in the limit of vanishing viscous forces at temperatures . The polarization of the quantized vortices with respect to the axis of rotation is measured using non-invasive NMR techniques. We observe a decrease of the polarization when the librating motion is started, and a two-stage relaxation process when the modulation of the rotation velocity is stopped. The first relaxation process is associated with the dissipation of large-scale flow stored in inertial waves and the solid body rotation of the vortex array. From the decay of these energy reservoirs we determine the rate of energy dissipation of large-scale flow. The later second process is related to the relaxation of Kelvin waves on individual vortices. This process is monitored by the recovery of the polarization. The existence of a Kelvin wave cascade at the lowest temperatures is currently a central open question. We supply some evidence for the cascade
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