15 research outputs found

    Mesozooplankton distribution, production and respiration in the global ocean.

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    Mesozooplankton biomass, abundance and mass-specific physiological rates as well as community production and respiration in the upper 2000 m were assessed from samples collected during the Malaspina circumnavigation expedition (~35ºN-40ºS) using an image-based analysis system (IBS). Equations relating metabolic rates, temperature, and body weight, were developed according to temperature ranges found at the different ocean regions and depth layers. High abundance and biomass were observed in the epipelagic zone and decreasing with depth as expected. However, high biomass was also found beyond 1000 m related to the colder and productive waters of the eastern regions of the Indian and Pacific Oceans. Specific growth and respiration rates followed a similar pattern and were highly correlated with temperature (r2=0.835 and 0.806 , respectively). Therefore, higher values were observed in the tropical and subtropical zones as the effect of higher temperature. Community production and respiration were considerably higher in the epipelagic layer, matching the distribution of biomass, with high values below 1000 m in the eastern Pacific/Indian Oceans. Global metabolism assessed through the IBS was similar to previous results based on data review.MALASPINA (CSD2008-00077

    Diel vertical migrants and the ocean carbon pump: is there a ladder of migration?

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    Active flux performed by migrant biota is still a gap in the knowledge of the biological pump in the ocean. These organisms mainly feed upon epipelagic zooplankton and transport this carbon due to their feeding at the shallower layers and their defecation, respiration, excretion and mortality at depth. The recent finding that mesopelagic fish biomass in the ocean is one order of magnitude higher indicates that the active flux should be thoroughly evaluated. Here, we show enhanced plankton biomass, ranging from bacteria to zooplankton, reaching down to 4,000 m depth below the Atlantic and Pacific equatorial upwelling systems. We also found a striking close relationship between the zooplankton backscatter enhancement in the epi-, meso- and bathypelagic zones. Backscatter increased in a similar proportion along the subtropical, tropical, and equatorial areas in the three zones. Literature, recent data in subtropical waters, and these results suggest an intense active carbon transport from the epipelagic layer to the deep sea driven by zooplankton and micronekton, enhancing the efficiency of the biological pump and promoting true carbon sequestration beyond 1000 m depth.MALASPINA (CSD2008 00077) MAFIA (CTM2012-39587-C04

    Trends and outcome of neoadjuvant treatment for rectal cancer: A retrospective analysis and critical assessment of a 10-year prospective national registry on behalf of the Spanish Rectal Cancer Project

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    Introduction: Preoperative treatment and adequate surgery increase local control in rectal cancer. However, modalities and indications for neoadjuvant treatment may be controversial. Aim of this study was to assess the trends of preoperative treatment and outcomes in patients with rectal cancer included in the Rectal Cancer Registry of the Spanish Associations of Surgeons. Method: This is a STROBE-compliant retrospective analysis of a prospective database. All patients operated on with curative intention included in the Rectal Cancer Registry were included. Analyses were performed to compare the use of neoadjuvant/adjuvant treatment in three timeframes: I)2006–2009; II)2010–2013; III)2014–2017. Survival analyses were run for 3-year survival in timeframes I-II. Results: Out of 14, 391 patients, 8871 (61.6%) received neoadjuvant treatment. Long-course chemo/radiotherapy was the most used approach (79.9%), followed by short-course radiotherapy ± chemotherapy (7.6%). The use of neoadjuvant treatment for cancer of the upper third (15-11 cm) increased over time (31.5%vs 34.5%vs 38.6%, p = 0.0018). The complete regression rate slightly increased over time (15.6% vs 16% vs 18.5%; p = 0.0093); the proportion of patients with involved circumferential resection margins (CRM) went down from 8.2% to 7.3%and 5.5% (p = 0.0004). Neoadjuvant treatment significantly decreased positive CRM in lower third tumors (OR 0.71, 0.59–0.87, Cochrane-Mantel-Haenszel P = 0.0008). Most ypN0 patients also received adjuvant therapy. In MR-defined stage III patients, preoperative treatment was associated with significantly longer local-recurrence-free survival (p < 0.0001), and cancer-specific survival (p < 0.0001). The survival benefit was smaller in upper third cancers. Conclusion: There was an increasing trend and a potential overuse of neoadjuvant treatment in cancer of the upper rectum. Most ypN0 patients received postoperative treatment. Involvement of CRM in lower third tumors was reduced after neoadjuvant treatment. Stage III and MRcN + benefited the most

    The genetic architecture of the human cerebral cortex

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    INTRODUCTION The cerebral cortex underlies our complex cognitive capabilities. Variations in human cortical surface area and thickness are associated with neurological, psychological, and behavioral traits and can be measured in vivo by magnetic resonance imaging (MRI). Studies in model organisms have identified genes that influence cortical structure, but little is known about common genetic variants that affect human cortical structure. RATIONALE To identify genetic variants associated with human cortical structure at both global and regional levels, we conducted a genome-wide association meta-analysis of brain MRI data from 51,665 individuals across 60 cohorts. We analyzed the surface area and average thickness of the whole cortex and 34 cortical regions with known functional specializations. RESULTS We identified 306 nominally genome-wide significant loci (P < 5 × 10−8) associated with cortical structure in a discovery sample of 33,992 participants of European ancestry. Of the 299 loci for which replication data were available, 241 loci influencing surface area and 14 influencing thickness remained significant after replication, with 199 loci passing multiple testing correction (P < 8.3 × 10−10; 187 influencing surface area and 12 influencing thickness). Common genetic variants explained 34% (SE = 3%) of the variation in total surface area and 26% (SE = 2%) in average thickness; surface area and thickness showed a negative genetic correlation (rG = −0.32, SE = 0.05, P = 6.5 × 10−12), which suggests that genetic influences have opposing effects on surface area and thickness. Bioinformatic analyses showed that total surface area is influenced by genetic variants that alter gene regulatory activity in neural progenitor cells during fetal development. By contrast, average thickness is influenced by active regulatory elements in adult brain samples, which may reflect processes that occur after mid-fetal development, such as myelination, branching, or pruning. When considered together, these results support the radial unit hypothesis that different developmental mechanisms promote surface area expansion and increases in thickness. To identify specific genetic influences on individual cortical regions, we controlled for global measures (total surface area or average thickness) in the regional analyses. After multiple testing correction, we identified 175 loci that influence regional surface area and 10 that influence regional thickness. Loci that affect regional surface area cluster near genes involved in the Wnt signaling pathway, which is known to influence areal identity. We observed significant positive genetic correlations and evidence of bidirectional causation of total surface area with both general cognitive functioning and educational attainment. We found additional positive genetic correlations between total surface area and Parkinson’s disease but did not find evidence of causation. Negative genetic correlations were evident between total surface area and insomnia, attention deficit hyperactivity disorder, depressive symptoms, major depressive disorder, and neuroticism. CONCLUSION This large-scale collaborative work enhances our understanding of the genetic architecture of the human cerebral cortex and its regional patterning. The highly polygenic architecture of the cortex suggests that distinct genes are involved in the development of specific cortical areas. Moreover, we find evidence that brain structure is a key phenotype along the causal pathway that leads from genetic variation to differences in general cognitive function

    Diel vertical migrants and the ocean carbon pump: is there a ladder of migration?

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    Aquatic Sciences Meeting, Aquatic Sciences: Global And Regional Perspectives - North Meets South, 22-27 February 2015, Granada, SpainActive flux performed by migrant biota is still a gap in the knowledge of the biological pump in the ocean. These organisms mainly feed upon epipelagic zooplankton and transport this carbon due to their feeding at the shallower layers and their defecation, respiration, excretion and mortality at depth. The recent finding that mesopelagic fish biomass in the ocean is one order of magnitude higher indicates that the active flux should be thoroughly evaluated. Here, we show enhanced plankton biomass, ranging from bacteria to zooplankton, reaching down to 4,000 m depth below the Atlantic and Pacific equatorial upwelling systems. We also found a striking close relationship between the zooplankton backscatter enhancement in the epi-, meso- and bathypelagic zones. Backscatter increased in a similar proportion along the subtropical, tropical, and equatorial areas in the three zones. Literature, recent data in subtropical waters, and these results suggest an intense active carbon transport from the epipelagic layer to the deep sea driven by zooplankton and micronekton, enhancing the efficiency of the biological pump and promoting true carbon sequestration beyond 1000 m depth.Peer Reviewe
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