83 research outputs found

    Do Larval Supply and Recruitment Vary among Chemosynthetic Environments of the Deep Sea?

    Get PDF
    BACKGROUND: The biological communities that inhabit chemosynthetic environments exist in an ephemeral and patchily distributed habitat with unique physicochemical properties that lead to high endemicity. Consequently, the maintenance and recovery from perturbation of the populations in these habitats is, arguably, mainly regulated by larval supply and recruitment. METHODOLOGY/PRINCIPAL FINDINGS: WE USE DATA FROM THE PUBLISHED SCIENTIFIC LITERATURE TO: (1) compare the magnitudes of and variability in larval supply and settlement and recruitment at hydrothermal vents, seeps, and whale, wood and kelp falls; (2) explore factors that affect these life history processes, when information is available; and (3) explore taxonomic affinities in the recruit assemblages of the different chemosynthetic habitats, using multivariate statistical techniques. Larval supply at vents can vary across segments by several orders of magnitude for gastropods; for bivalves, supply is similar at vents on different segments, and at cold seeps. The limited information on larval development suggests that dispersal potential may be highest for molluscs from cold seeps, intermediate for siboglinids at vents and lowest for the whale-bone siboglinid Osedax. Settlement is poorly studied and only at vents and seeps, but tends to be highest near an active source of emanating fluid in both habitats. Rate of recruitment at vents is more variable among studies within a segment than among segments. Across different chemosynthetic habitats, recruitment rate of bivalves is much more variable than that of gastropods and polychaetes. Total recruitment rate ranges only between 0.1 and 1 ind dm(-2) d(-1) across all chemosynthetic habitats, falling above rates in the non-reducing deep sea. The recruit assemblages at vents, seeps and kelp falls have lower taxonomic breadth, and include more families and genera that have many species more closely related to each other than those at whale and wood falls. Vents also have the most uneven taxonomic structure, with fewer recruits represented by higher taxonomic levels (phyla, orders, classes) compared to seeps and wood and kelp falls, whereas the opposite is true at whale falls. CONCLUSIONS/SIGNIFICANCE: Based on our evaluation of the literature, the patterns and regulatory factors of the early history processes in chemosynthetic environments in the deep sea remain poorly understood. More research focused on these early life history stages will allow us to make inferences about the ecological and biogeographic linkages among the reducing habitats in the deep sea

    Is There an Economical Running Technique? A Review of Modifiable Biomechanical Factors Affecting Running Economy

    Get PDF

    Behavioral and Cognitive Improvement Induced by Novel Imidazoline I2 Receptor Ligands in Female SAMP8 Mice

    Full text link
    As populations increase their life expectancy, age-related neurodegenerative disorders such as Alzheimer's disease have become more common. I2-Imidazoline receptors (I2-IR) are widely distributed in the central nervous system, and dysregulation of I2-IR in patients with neurodegenerative diseases has been reported, suggesting their implication in cognitive impairment. This evidence indicates that high-affinity selective I2-IR ligands potentially contribute to the delay of neurodegeneration. In vivo studies in the female senescence accelerated mouse-prone 8 mice have shown that treatment with I2-IR ligands, MCR5 and MCR9, produce beneficial effects in behavior and cognition. Changes in molecular pathways implicated in oxidative stress, inflammation, synaptic plasticity, and apoptotic cell death were also studied. Furthermore, treatments with these I2-IR ligands diminished the amyloid precursor protein processing pathway and increased Aβ degrading enzymes in the hippocampus of SAMP8 mice. These results collectively demonstrate the neuroprotective role of these new I2-IR ligands in a mouse model of brain aging through specific pathways and suggest their potential as therapeutic agents in brain disorders and age-related neurodegenerative diseases. Keywords Imidazoline I2 receptors (2-imidazolin-4-yl)phosphonates Behavior Cognition Neurodegeneration Neuroprotection Agin

    Direct characterization of commercial lecithins by easy ambient sonic-spray ionization mass spectrometry

    No full text
    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Commercial lecithins are composed mainly of phospholipids and triacylglycerols. The analysis of the commercial lecithins, including their fraction of phospholipids, normally involves laborious and expensive protocols. Easy ambient sonic-spray ionization mass spectrometry (EASI-MS) is shown to be an efficient technique for the analysis of lipids. Samples of commercial lecithins including standards, refined, deoiled and modified soy lecithin were tested. Characteristic profiles of phosphatidylcholines and triacylglycerols are detected by EASI(+)-MS, whereas EASI(-)-MS provided phosphatidylethanolamines, glycophospholipids and free fatty acids profiles. Acetylated lecithins also displayed characteristic acetylated derivatives. EASI-MS data was also compared to MALDI-MS, and found to display richer compositional information. The industrial process applied to lecithin fabrication was also characterised via typical EASI-MS profiles. EASI-MS both in its positive and negative ion modes offers a direct, fast and efficient technique able to characterise commercial lecithin. (C) 2012 Elsevier Ltd. All rights reserved.135318551860Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Financing Agency of StudiesFINEPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Proyecto de desarrollo para la realización de la reingenieria administrativa financiera y operativa de comercial marcelito & piladora los bosques

    Get PDF
    El desarrollo del presente trabajo, tiene como objetivo fundamental, la reingeniería de Comercial Marcelito, el cual se dedica a la comercialización de productos agrícolas, la cual propone un rediseño radical de sus procesos para minimizar y solucionar los problemas en los aspectos: administrativo, operativo y financiero y conseguir mejoras inmensas en medidas de valor como son costos, calidad y servicio. Para la consecución de los objetivos se recogió toda la información necesaria de la empresa para el estudio, se aplico las técnicas de análisis financiero y de Mercado para posteriormente hacer las recomendaciones de aplicación necesarias para que la empresa pueda mejorar su situación en los aspectos ya mencionados. La reingeniería administrativa propone cambios en la forma de organización, en las metas a alcanzar. La reingeniería operativa implica un ajuste en los procesos de recolección para eliminar mermas como es la implementación de maquinaria recolectora, la clasificación de las bodegas y la implementación de sistemas de información. La reingeniería financiera hace énfasis en la estructura financiera de la empresa antes y después de la reingeniería demostrando la factibilidad del proyecto.ESPO

    Assessing the effect of patient navigator assistance for psychosocial support services on health‐related quality of life in a randomized clinical trial in Latino breast, prostate, and colorectal cancer survivors

    No full text
    Background After a diagnosis of prostate, breast, or colorectal cancer, Latinos experience higher mortality rates and lower health‐related quality of life (HRQOL) in comparison with other ethnic/racial groups. Patient navigation (PN) and lay community health workers or promotores are effective in increasing cancer screening and early‐stage diagnosis among Latinos. However, little is known about the effect of PN on HRQOL among Latino cancer survivors. Methods Latinos previously diagnosed with breast, prostate, or colorectal cancer (n = 288) were randomized to 1 of 2 conditions: 1) the Patient Navigator LIVESTRONG Cancer Navigation Services (PN‐LCNS) survivor care program or 2) PN only. HRQOL was measured with the Functional Assessment of Cancer Therapy–General, and cancer‐specific HRQOL was measured with the Functional Assessment of Cancer Therapy–Breast, the Functional Assessment of Cancer Therapy–Prostate, and the Functional Assessment of Cancer Therapy–Colorectal for breast, prostate, and colorectal cancer survivors, respectively, at the baseline and at 3 follow‐up time points. Generalized estimating equation analyses were conducted to estimate the effect of condition on HRQOL with adjustments for covariates and baseline HRQOL. Results PN‐LCNS demonstrated a significant improvement in HRQOL in comparison with PN only for colorectal cancer survivors but not for breast and prostate cancer survivors. Conclusions Enhanced PN improves HRQOL among Latino colorectal cancer survivors. Future research should identify the best strategies for engaging Latino survivors in PN programs. PN programs should also be adapted to address HRQOL concerns among Latina breast cancer survivors. An enhanced patient navigation program demonstrates an improvement in health‐related quality of life among Latino survivors of prostate and colorectal cancer when the service is actively used. Future research should be aimed at identifying the best strategies for engaging Latino survivors in patient navigation programs
    corecore