8,663 research outputs found

    Motivations for high performance teams of information systems projects

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    As equipas de elevado desempenho apresentam características únicas que as diferenciam das restantes, sendo um dos aspetos fundamentais a motivação dos seus elementos. Neste trabalho são apresentados os resultados parciais de um estudo de caso focado no elevado desempenho das equipas de projetos de sistemas de informação. Muito concretamente, identifica-se um conjunto de aspetos que contribuem para a motivação dos elementos de uma equipa, de acordo com a sua própria perspetiva. Este trabalho visa proporcionar uma melhor compreensão dos aspetos que influenciam a motivação dos elementos das equipas de elevado desempenho e, assim, contribuir para o estudo e prática da gestão de projetos de sistemas de informação.High performance teams present unique characteristics that make them distinct from the others, being one of the fundamental aspects the motivation of its elements. In this paper are presented the partial results of a case study focused on high performance teams of information systems projects. Specifically, it is identified a set of aspects that contribute to the motivation of the team’s elements, according to their own perspective. This work aims to provide a better understanding of the aspects that influence the motivation of the elements for high performance teams and thus contribute to the study and practice of information systems project management.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio

    Proteins involved in mitochondrial metabolic functions and fertilization predominate in stallions with better motility

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    Even in stallions with sperm quality within normal reference ranges at ejaculation, subtle differences in sperm quality exist that in many cases lead to reduced time frames for conservation of the ejaculate and/or reduced fertility. The spermatozoon is a cell highly suitable for proteomics studies, and the use of this technique is allowing rapid advances in the understanding of sperm biology. The aim of the present study was to investigate differences among stallions of variable sperm quality (based on motility and sperm velocities), although all horses had sperm characteristics within normal ranges. The proteome was studied using UHPLC/MS/MS and posterior bioinformatic and enrichment analysis; data are available via ProteomeXchange with identifier PXD025807. Sperm motility, linear motility and circular, straight line and average velocities (VCL, VSL, VAP) were measured using computer assisted sperm analysis (CASA). In stallions showing better percentages of motility, circular and average velocity predominated mitochondrial proteins with roles in the Citric acid cycle, pyruvate metabolism and oxidative phosphorylation. Interestingly, in stallions with better percentages of total motility, sperm proteins were also enriched in proteins within the gene ontology (G0) terms, single fertilization (G0: 0007338), fertilization (G0: 0009566), and zona pellucida receptor complex (GO:0002199). The enrichment of this proteins in samples with better percentages of total motility may offer a molecular explanation for the link between this parameter and fertility. Significance: Proteomic analysis identified a high degree of specificity of stallion sperm proteins with discriminant power for motility, linear motility, and sperm velocities (VCL, VAP and VSL). These findings may represent an interesting outcome in relation to the molecular biology regulating the movement of the spermatozoa, and the biological meaning of the measurements that computer assisted sperm analysis (CASA) provide. Of a total of 903 proteins identified in stallion spermatozoa, 24 were related to the percentage of total motility in the sample; interestingly, gene ontology (G0) analysis revealed that these proteins were enriched in terms like single fertilization and fertilization, providing a molecular link between motility and fertility. Field studies indicate that the percentage of total motility is the CASA derived parameter with the best correlation with fertility in stallions

    Microsatellite alterations and TP53 mutations in plasma DNA of small-cell lung cancer patients: Follow-up study and prognostic significance

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    Background: Small-cell lung cancer (SCLC), one of the major types of lung cancer, is associated with many different somatic molecular genetic changes. These alterations, observed in tumor DNA, have also been identified in the plasma DNA of patients. We undertook the present study to make a prospective investigation into the correlation between abnormal plasma DNA and patient survival. Patients and methods: Thirty-five patients with SCLC were selected after histological diagnosis. Polymorphic markers (ACTBP2, UT762 and AR) were chosen for their reported high rate of alterations in SCLC and analyzed in tumor tissue, normal blood cells and plasma DNA. Furthermore, we looked for mutations of the TP53 gene in tumor and plasma DNA. Results: In 25 patients (71%) at least one molecular change precisely matching that of the primary tumor was detected in the plasma DNA. No difference in survival was observed between patients with aberrant plasma DNA and patients without plasma DNA alterations. However, patients with microsatellite modifications and TP53 mutations concomitantly, showed a significant difference (P = 0.02) in survival compared with patients bearing only one of these molecular changes. In 15 cases it was possible to find a correlation either between tumor response and disappearance of abnormal plasma DNA, or tumor progression and persistence of plasma DNA alterations. Conclusions: Free plasma DNA with molecular alterations is present to a high degree in plasma DNA of SCLC patients and may have a role as a prognostic facto

    The dust content of high-z submillimeter galaxies revealed by Herschel

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    We use deep observations taken with the Photodetector Array Camera and Spectrometer (PACS), on board the Herschel satellite as part of the PACS evolutionary probe (PEP) guaranteed project along with submm ground-based observations to measure the dust mass of a sample of high-z submillimeter galaxies (SMGs). We investigate their dust content relative to their stellar and gas masses, and compare them with local star-forming galaxies. High-z SMGs are dust rich, i.e. they have higher dust-to-stellar mass ratios compared to local spiral galaxies (by a factor of 30) and also compared to local ultraluminous infrared galaxies (ULIRGs, by a factor of 6). This indicates that the large masses of gas typically hosted in SMGs have already been highly enriched with metals and dust. Indeed, for those SMGs whose gas mass is measured, we infer dust-to-gas ratios similar or higher than local spirals and ULIRGs. However, similarly to other strongly star-forming galaxies in the local Universe and at high-z, SMGs are characterized by gas metalicities lower (by a factor of a few) than local spirals, as inferred from their optical nebular lines, which are generally ascribed to infall of metal-poor gas. This is in contrast with the large dust content inferred from the far-IR and submm data. In short, the metalicity inferred from the dust mass is much higher (by more than an order of magnitude) than that inferred from the optical nebular lines. We discuss the possible explanations of this discrepancy and the possible implications for the investigation of the metalicity evolution at high-z.Comment: Accepted for publication in Astronomy & Astrophysics Letters. One reference update

    Benthic O-2 uptake by coral gardens at the Condor seamount (Azores)

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    Using the non-invasive aquatic eddy covariance technique, we provide the first oxygen (O-2) uptake rates from within coral gardens at the Condor seamount (Azores). To explore some of the key drivers of the benthic O-2 demand, we obtained benthic images, quantified local hydrodynamics, and estimated phototrophic biomass and deposition dynamics with a long-term moored sediment trap. The coral gardens were dominated by the octocorals Viminella flagellum and Dentomuricea aff. meteor. Daily rates of O-2 uptake within 3 targeted coral garden sites (203 to 206 m depth) ranged from 10.0 t 0.88 to 18.8 +/- 2.0 mmol m(-2) d(-1) (mean +/- SE) and were up to 10 times higher than 2 local sandy reference sites within the seamount summit area. The overall mean O-2 uptake rate for the garden (13.4 mmol m(-2) d(-1)) was twice the global mean for sedimentary habitats at comparable depths. Combined with parallel ex situ incubations, the results suggest that the octocorals might contribute just -similar to 5% of the observed O-2 uptake rates. Deposition of particulate organic matter (POM) assessed by the sediment trap accounted for less than 10% of the O-2 demand of the coral garden, implying a substantial POM supply circumventing the deployed traps. Our results expand the database for carbon turnover rates in cold-water coral habitats by including the first estimates from these largely understudied coral gardens.Peer reviewe

    Proteomic profiling of stallion spermatozoa suggests changes in sperm metabolism and compromised redox regulation after cryopreservation

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    Proteomic technologies allow the detection of thousands of proteins at the same time, being a powerful technique to reveal molecular regulatory mechanisms in spermatozoa and also sperm damage linked to low fertility or specific biotechnologies. Modifications induced by the cryopreservation in the stallion sperm proteome were studied using UHPLC/MS/MS. Ejaculates from fertile stallions were collected and split in two subsamples, one was investigated as fresh (control) samples, and the other aliquot frozen and thawed using standard procedures and investigated as frozen thawed subsamples. UHPLC/MS/MS was used to study the sperm proteome under these two distinct conditions and bioinformatic enrichment analysis conducted. Gene Ontology (GO) and pathway enrichment analysis were performed revealing dramatic changes as consequence of cryopreservation. The terms oxidative phosphorylation, mitochondrial ATP synthesis coupled electron transport and electron transport chain were significantly enriched in fresh samples (P = 5.50 × 10−12, 4.26 × 10−8 and 7.26 × 10–8, respectively), while were not significantly enriched in frozen thawed samples (P = 1). The GO terms oxidation reduction process and oxidoreductase activity were enriched in fresh samples and the enrichment was reduced in frozen thawed samples (1.40 × 10−8, 1.69 × 10−6 versus 1.13 × 10−2 and 2-86 × 10−2 respectively). Reactome pathways (using human orthologs) significantly enriched in fresh sperm were TCA cycle and respiratory electron transport (P = 1.867 × 10−8), Respiratory electron transport ATP synthesis by chemiosmosis coupling (P = 2.124 × 10−5), Citric acid cycle (TCA cycle)(P = 8.395 × 10−4) Pyruvate metabolism and TCA cycle (P = 3.380 × 10−3), Respiratory electron transport (P = 2.764 × 10−2) and Beta oxidation of laurolyl-CoA to decanoyl CoA-CoA (P = 1.854 × 10−2) none of these pathways were enriched in thawed samples (P = 1). We have provided the first detailed study on how the cryopreservation process impacts the stallion sperm proteome. Our findings identify the metabolic proteome and redoxome as the two key groups of proteins affected by the procedure. Significance: In the present manuscript we investigated how the cryopreservation of stallion spermatozoa impacts the proteome of these cells. This procedure is routinely used in horse breeding and has a major impact in the industry, facilitating the trade of genetic material. This is still a suboptimal biotechnology, with numerous unresolved problems. The limited knowledge of the molecular insults occurring during cryopreservation is behind these problems. The application and development of proteomics to the spermatozoa, allow to obtain valuable information of the specific mechanisms affected by the procedure. In this paper, we report that cryopreservation impacts numerous proteins involved in metabolism regulation (mainly mitochondrial proteins involved in the TCA cycle, and oxidative phosphorylation) and also affects proteins with oxidoreductase activity. Moreover, specific proteins involved in the sperm-oocyte interaction are also affected by the procedure. The information gathered in this study, opens interesting questions and offer new lines of research for the improvement of the technology focusing the targets here identified, and the specific steps in the procedure (cooling, toxicity of antioxidants etc.) to be modified to reduce the damage
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