1,976 research outputs found
The Internet Usage among Students: A Uses and Gratifications Perspective
Uses and gratifications research helps in finding out how audience makes use of mass media to gratify their needs. Media research can help both the industry and the academia to map audience behaviour which is very much connected to various factors such as geography, culture, education and socio-economic circumstances. This research conducted among students reveals that students make use of the Internet primarily with an entertainment motive, and only secondarily for education and current affairs knowledge. The study also reveals that digital divide is widely prevalent and it is an important issue to be looked at especially in terms of gender, though the digital divide has been narrowing among students in terms of geography
Bearing My Heart: The Role of Extracellular Matrix on Cardiac Development, Homeostasis, and Injury Response
The extracellular matrix (ECM) is an essential component of the heart that imparts fundamental cellular processes during organ development and homeostasis. Most cardiovascular diseases involve severe remodeling of the ECM, culminating in the formation of fibrotic tissue that is deleterious to organ function. Treatment schemes effective at managing fibrosis and promoting physiological ECM repair are not yet in reach. Of note, the composition of the cardiac ECM changes significantly in a short period after birth, concurrent with the loss of the regenerative capacity of the heart. This highlights the importance of understanding ECM composition and function headed for the development of more efficient therapies. In this review, we explore the impact of ECM alterations, throughout heart ontogeny and disease, on cardiac cells and debate available approaches to deeper insights on cell–ECM interactions, toward the design of new regenerative therapies.This work was funded by the European Regional Development Fund (ERDF) through COMPETE 2020, Portugal 2020, and by the FCT (Fundação para a Ciência e Tecnologia) (POCI-01-0145-FEDER-030985) and by the FCT/Ministério da Ciência, Tecnologia e Inovação in the framework of individual funding (CEECINST/00091/2018) to DN
Cyclin D 1‐induced proliferation is independent of beta‐catenin in H ead and N eck C ancer
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106775/1/odi12124.pd
Choice biases in no-sample and delay testing in pigeons (Columba livia)
In experimental tasks that involve stimuli that vary along a quantitative continuum, some choice biases are commonly found. Take, for instance, a matching-to-sample task where animals must, following the presentation of sample stimuli (that differ in duration), choose between two or more comparison stimuli. In tests where no sample is presented there is usually a bias towards the comparison that is correct following the shortest sample. To examine some aspects of these choice biases, pigeons were trained in a symbolic matching-to-sample task with two durations of keylight as samples, where key pecking had to be maintained during sample presentation. Firstly, even though animals were required to attend to the sample, a preference for the "short" comparison in no-sample testing was found. This result disproves an account where this effect was hypothesized to happen due to non-programmed learning resulting from the animals failing to attend to some trials. Secondly, even though a bias for "short" was found in both no-sample and delay testing, the extent of the biases differed between tasks, thus suggesting that forgetting the sample presented during a delay does not necessarily land the animal in a state similar to presenting no sample at all to begin with.The present study was supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and Higher Education through national funds. It was also co-financed by the European Regional Development Fund (FEDER)-through COMPETE2020-under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653)
Establishing a link between endothelial cell metabolism and vascular behaviour in a type 1 diabetes mouse model
Background/Aims: Vascular complications contribute significantly to the extensive morbidity and mortality rates observed in people with diabetes. Despite well known that the diabetic kidney and heart exhibit imbalanced angiogenesis, the mechanisms implicated in this angiogenic paradox remain unknown. In this study, we examined the angiogenic and metabolic gene expression profile (GEP) of endothelial cells (ECs) isolated from a mouse model with type1 diabetes mellitus (T1DM). Methods: ECs were isolated from kidneys and hearts of healthy and streptozocin (STZ)-treated mice. RNA was then extracted for molecular studies. GEP of 84 angiogenic and 84 AMP-activated Protein Kinase (AMPK)-dependent genes were examined by microarrays. Real time PCR confirmed the changes observed in significantly altered genes. Microvessel density (MVD) was analysed by immunohistochemistry, fibrosis was assessed by the Sirius red histological staining and connective tissue growth factor (CTGF) was quantified by ELISA. Results: The relative percentage of ECs and MVD were increased in the kidneys of T1DM animals whereas the opposite trend was observed in the hearts of diabetic mice. Accordingly, the majority of AMPK-associated genes were upregulated in kidneys and downregulated in hearts of these animals. Angiogenic GEP revealed significant differences in Tgfß, Notch signaling and Timp2 in both diabetic organs. These findings were in agreement with the angiogenesis histological assays. Fibrosis was augmented in both organs in diabetic as compared to healthy animals. Conclusion: Altogether, our findings indicate, for the first time, that T1DM heart and kidney ECs present opposite metabolic cues, which are accompanied by distinct angiogenic patterns. These findings enable the development of innovative organ-specific therapeutic strategies targeting diabetic-associated vascular disorders.This work was supported by CAPES (Sciences without Borders - Full Doctorate Fellowship – Process 10010-13-0); FEDER funds by COMPETE: [POCI-01-0145-FEDER-007440, POCI-01-0145-FEDER-016385]; NORTE2020 [NORTE-01-0145FEDER-000012]; HealthyAging2020 [CENTRO-01-0145-FEDER-000012-N2323]; FCT - Fundação para a Ciência e a Tecnologia [UID/BIM/04293/2013, EXPL/BIM-MED/0492/2012, SFRH/BPD/88745/2012, SFRH/BD/111799/2015]; Claude Pepper Older Americans Independence Center; grant: P30 AG028718, NIGMS Award P20GM109096; European Structural and Investment Funds (ESIF). AUTHOR CONTRIBUTION: CS and RS participated in the design and conception of the study; CS performed the whole laboratory and statistical analyses and drafted the manuscript; VSP, PPO, DSN carried out the FACS assay design and data acquisition, as well as the interpretation of FACS data; SA advised and performed microarray and RT-PCR assays; IR headed the parafin embedded tissue and histologial staining; SG, EC were responsible for the animal studies and immunohistochemistry analyses; RC advised the methodological laboratorial analysis and animal studies; RS and EC critically revised the manuscript for important intellectual content. All authors were involved in drafting and revising the article. All authors read and approved the final version of the manuscript
Consistent Long-Term Therapeutic Efficacy of Human Umbilical Cord Matrix-Derived Mesenchymal Stromal Cells After Myocardial Infarction Despite Individual Differences and Transient Engraftment
Human mesenchymal stem cells gather special interest as a universal and feasible add-on therapy for myocardial infarction (MI). In particular, human umbilical cord matrix-derived mesenchymal stromal cells (UCM-MSC) are advantageous since can be easily obtained and display high expansion potential. Using isolation protocols compliant with cell therapy, we previously showed UCM-MSC preserved cardiac function and attenuated remodeling 2 weeks after MI. In this study, UCM-MSC from two umbilical cords, UC-A and UC-B, were transplanted in a murine MI model to investigate consistency and durability of the therapeutic benefits. Both cellular products improved cardiac function and limited adverse cardiac remodeling 12 weeks post-ischemic injury, supporting sustained and long-term beneficial therapeutic effect. Donor associated variability was found in the modulation of cardiac remodeling and activation of the Akt-mTOR-GSK3ß survival pathway. In vitro, the two cell products displayed similar ability to induce the formation of vessel-like structures and comparable transcriptome in normoxia and hypoxia, apart from UCM-MSCs proliferation and expression differences in a small subset of genes associated with MHC Class I. These findings support that UCM-MSC are strong candidates to assist the treatment of MI whilst calling for the discussion on methodologies to characterize and select best performing UCM-MSC before clinical application.This work was funded by European Structural and Investment Funds (ESIF), under Lisbon Portugal Regional Operational Programme and National Funds through Fundação para a Ciência e Tecnologia (FCT) ([POCI-01-0145-FEDER-030985], [POCI-01-0145-FEDER-016385]); by FCT/Ministério da Ciência, Tecnologia e Inovação in the framework of individual funding [CEECINST/00091/2018] to DN and by QREN funds through the project ClinUCX (QREN 30196) and individual fellowships: [PD/BD/127997/2016] to TL, [SFRH/BD/144490/2019] to RG and [SFRH/BD/111799/2015] to VS-P. The funding bodies other than ECBio had no role in design, in the collection, analysis, and interpretation of data; in the writing of the manuscript; or in the decision to submit the manuscript for publication
Robust gap repair in the contractile ring ensures timely completion of cytokinesis.
Cytokinesis in animal cells requires the constriction of an actomyosin contractile ring, whose architecture and mechanism remain poorly understood. We use laser microsurgery to explore the biophysical properties of constricting rings in Caenorhabditis elegans embryos. Laser cutting causes rings to snap open. However, instead of disintegrating, ring topology recovers and constriction proceeds. In response to severing, a finite gap forms and is repaired by recruitment of new material in an actin polymerization-dependent manner. An open ring is able to constrict, and rings repair from successive cuts. After gap repair, an increase in constriction velocity allows cytokinesis to complete at the same time as controls. Our analysis demonstrates that tension in the ring increases while net cortical tension at the site of ingression decreases throughout constriction and suggests that cytokinesis is accomplished by contractile modules that assemble and contract autonomously, enabling local repair of the actomyosin network. Consequently, cytokinesis is a highly robust process impervious to discontinuities in contractile ring structure.This project has received funding from the European Research Council
(grants 640553, 260892, and 338410), Fundo Europeu de
Desenvolvimento Regional (FED ER) funds through the Operational
Competitiveness Program (COM PETE), national funds through
Fundação para a Ciência e a Tecnologia (FCT) under the project
FCO MP-01-0124-FED ER-028255 (PTDC/BEX-BCM/0654/2012),
Fundação Luso-Americana para o Desenvolvimento Life Science
2020, and the Louis-Jeantet Young Investigator Award to H. Maiato.
A.X. Carvalho, R. Gassmann, and I.A. Telley have FCT Investigator
positions funded by FCT and cofunded by the European Social Fund
through Programa Operacional Temático Potencial Type 4.2 promotion
of scientific employment. A.M. Silva holds an FCT fellowship
(SFRH/BPD/95707/2013). D.S. Osório was cofunded by the Programa
Operacional Regional do Norte under the Quadro de
Downloaded from jcb.rupress.org on February 27, 2018
Laser microsurgery in the contractile ring • Silva et al. 799
Referência Estratégico Nacional through FED ER and by FCT grant
NOR TE-07-0124-FED ER-000003 (Cell Homeostasis Tissue Organization
and Organism Biology)
Evaluation of Jackknife and Bootstrap for Defining Confidence Intervals for Pairwise Agreement Measures
Several research fields frequently deal with the analysis of diverse classification results of the same entities. This should imply an objective detection of overlaps and divergences between the formed clusters. The congruence between classifications can be quantified by clustering agreement measures, including pairwise agreement measures. Several measures have been proposed and the importance of obtaining confidence intervals for the point estimate in the comparison of these measures has been highlighted. A broad range of methods can be used for the estimation of confidence intervals. However, evidence is lacking about what are the appropriate methods for the calculation of confidence intervals for most clustering agreement measures. Here we evaluate the resampling techniques of bootstrap and jackknife for the calculation of the confidence intervals for clustering agreement measures. Contrary to what has been shown for some statistics, simulations showed that the jackknife performs better than the bootstrap at accurately estimating confidence intervals for pairwise agreement measures, especially when the agreement between partitions is low. The coverage of the jackknife confidence interval is robust to changes in cluster number and cluster size distribution
Diversidade genética em Trichechus manatus manatus mantidos em cativeiro na ilha de Itamaracá-PE
Este trabalho investigou a variabilidade genética de animais da espécie T. manatus manatus, provenientesdo programa de conservação de peixes-boi do Centro Mamíferos Aquáticos (CMA). Foramestudados 8 microssatélites, em todos os animais re-introduzidos pelo CMA nos últimos dois anos,n=11. Os baixos níveis de diversidade genética observados não parecem específicos desta população,mas característicos da espécie, como um todo. O conhecido decréscimo populacional sofrido por essesanimais não parece ter aumentado a endogamia, já que a heterozigose esperada foi superior à observada,na maioria dos sistemas polimórficos.Palavras-chave: diversidade genética, Trichechus manatus manatus, microssatélites
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