345 research outputs found

    Influence of various redox conditions on the degradation of microalgal triacylglycerols and fatty acids in marine sediments

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    Sediment cakes, supplemented with microalgal cells (Nannochloropsis salina), were incubated for 35 days under permanently oxic, oscillating (5d:5d changeover oxic/anoxic) and strictly anoxic conditions of oxygenation in diffusively ‘‘open’’ sedimentary systems. Total lipids (TLip) and triacylglycerols (TG) concentrations were monitored by thin layer chromatography-flame ionisation detection, whereas the concentrations of the main extractable (free+ester-bound) individual fatty acids (C16:0, C16:1, C18:1) were followed using gas chromatography-mass spectrometry. Under the three conditions of oxygenation, TOC, TLip and TG showed a sharp decrease in concentration during the early days of incubation and seemed to stabilise thereafter, defining an apparent non degradable fraction (GNR). The GNR content was systematically higher in the anoxic incubation than under the oxic and oscillating conditions. The ratio of the main hydrolysis products of TG versus TG [(Free fatty acids+Monoacylglycerols+1,2-Diacylglycerols)/TG], used as an indicator of the hydrolysis of TG, showed that the presence of oxygen in the sediments (oxic and oscillating conditions) stimulates the hydrolysis of TG and the subsequent degradation of their metabolites. Unlike TOC, TLip and TG, individual fatty acids (FA) showed a continuous concentration decrease until the end of the experiment, which was fitted with a simple first order model [G(t)=G0e_kt] to yield apparent degradation rate constants. The values observed under oscillating conditions (kFA=0.019 +/- 0.001 d_1) were intermediate to those observed during oxic (kFA=0.029 +/- 0.003 d_1) and anoxic (kFA=0.011 +/- 0.001 d_1) incubations, and no significant difference between individual FA could be observed. The production of saturated and monounsaturated C16 (and to a lesser extent C18) alkanols under oscillating and anoxic redox conditions suggested that (a part of) the dominant FA were reduced to the corresponding alcohols under anoxic conditions, following their release from acylglycerols

    Urinary excretion of prostaglandins and electrolytes in developing children

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    Urinary excretion of prostaglandins and electrolytes in developing children. A longitudinal study of the urinary excretion of prostaglandins (PG's) E and Fα was performed in 55 healthy children aged from 1 to 114 months. In addition, the urinary PG's and electrolytes were studied in 6 children with Bartier's syndrome before and after an oral treatment with indomethacin. In normal children, both urinary PGE and PGFα increased with age, more markedly before 24 months of age. During this period, a positive and significant correlation was found with the urinary osmolality (r = 0.61, N = 16, P < 0.05 for PGE; r = 0.82, N = 16, P < 0.001 for PGFα). At every age, the urinary PG's were related to the potassium excretion (r = 0.68, N = 55, P < 0.001 for PGE; r = 0.65, N = 55, P < 0.001 for PGFα) but not to the natriuresis. In children with Bartter's syndrome, the increased urinary excretion of PGE, PGFα and potassium was found to be consistently reduced after indomethacin treatment when the natriuresis was either decreased or increased after treatment. These results suggest that the renal PG's might play a role in the control of potassium excretion by the kidney. In addition, the determination of normal values in different age groups appears necessary for an accurate interpretation of the urinary PG's.Excrétion des prostaglandines urinaires et des électrolytes au cours du développement de l'enfant. L'élimination urinaire des prostaglandines (PG's) E et Fα a été étudiée chez 55 enfants normaux âgés de 1 à 114 mois ainsi que chez 6 enfants présentant un syndrome de Bartter, avant et après traitement par l'indométacine. Chez l'enfant normal, l'excrétion urinaire des PGE et PGFα augmente progressivement avec l'âge, surtout durant les 24 premiers mois de la vie où elle apparaît significativement corrélée à l'osmolalité urinaire (r = 0,61, N = 16, P < 0.05 pour PGE; r = 0.82, N = 16, P < 0.001 pour PGFα. Chez l'ensemble des 55 enfants normaux, elle n'apparaît pas liée à la natriurèse alors qu'elle est significativement corrélée à la kaliurèse (r = 0.68, N = 55, P < 0.001 pour PGE; r = 0.65, N = 55, P < 0.001 pour PGFα). Chez les enfants présentant un syndrome de Bartter, l'élimination urinaire des PGE et PGFα ainsi que la kaliurèse diminuent toujours sous indometacine alors que la natriurèse est soit diminuée, soit augmentée. Ces résultats suggèrent que les PG's rénales pourraient participer au contrôle de l'excrétion du potassium par le rein. Par ailleurs, il apparaît indispensable de se référer à des valeurs normales déterminées chez des sujets correctement appariés quant à l'age pour pouvoir interpréter d'une manière correcte les dosages urinaires

    Discovering Patient Phenotypes Using Generalized Low Rank Models

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    The practice of medicine is predicated on discovering commonalities or distinguishing characteristics among patients to inform corresponding treatment. Given a patient grouping (hereafter referred to as a p henotype ), clinicians can implement a treatment pathway accounting for the underlying cause of disease in that phenotype. Traditionally, phenotypes have been discovered by intuition, experience in practice, and advancements in basic science, but these approaches are often heuristic, labor intensive, and can take decades to produce actionable knowledge. Although our understanding of disease has progressed substantially in the past century, there are still important domains in which our phenotypes are murky, such as in behavioral health or in hospital settings. To accelerate phenotype discovery, researchers have used machine learning to find patterns in electronic health records, but have often been thwarted by missing data, sparsity, and data heterogeneity. In this study, we use a flexible framework called Generalized Low Rank Modeling (GLRM) to overcome these barriers and discover phenotypes in two sources of patient data. First, we analyze data from the 2010 Healthcare Cost and Utilization Project National Inpatient Sample (NIS), which contains upwards of 8 million hospitalization records consisting of administrative codes and demographic information. Second, we analyze a small (N=1746), local dataset documenting the clinical progression of autism spectrum disorder patients using granular features from the electronic health record, including text from physician notes. We demonstrate that low rank modeling successfully captures known and putative phenotypes in these vastly different datasets

    Locked-In Syndrome after Traumatic Basilar Artery Entrapment within a Clivus Fracture:A Case Report and Review of the Literature

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    We report the case of a 58-year-old male with a rare vascular complication after traumatic head injury: entrapment of the basilar artery into a fracture of the clivus, ultimately leading to a locked-in syndrome due to brainstem infarction. Review of the literature revealed 19 earlier published cases of basilar artery entrapment within traumatic longitudinal clival fractures. In the majority of these patients there is an unfavorable neurological outcome

    Paleocene–Eocene age glendonites from the Mid-Norwegian Margin – indicators of cold snaps in the hothouse?

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    The International Ocean Discovery Program (IODP) Expedition 396 to the mid-Norwegian margin recovered > 1300 m of pristinely preserved, volcanic-ash-rich sediments deposited during the late Paleocene and early Eocene from close to the centre of the North Atlantic Igneous Province (NAIP). Remarkably, many of these cores contain glendonites, pseudomorphs after the purported cold-water mineral ikaite, from sediments dated to the late Paleocene and early Eocene. These time intervals span some of the hottest climates of the Cenozoic, including the Paleocene–Eocene Thermal Maximum (PETM). Global deep-ocean temperatures are not thought to have dropped below 10 ∘C at any point during this time, making the occurrence of supposedly cold-water (near-freezing temperature) glendonite pseudomorphs seemingly paradoxical. This study presents a detailed sedimentological, geochemical, and microscopic study of the IODP Exp. 396 glendonites and presents an updated model for the ikaite-to-calcite transformation for these glendonites. Specifically, we show that early diagenesis of basaltic ashes of the NAIP appear to have chemically promoted ikaite growth in the sediments in this region. Together with existing knowledge of late Paleocene and early Eocene glendonites from Svalbard to the north and early Eocene glendonites from Denmark to the south, these new glendonite finds possibly imply episodic, short-duration, and likely localized cooling in the Nordic Seas region, which may have been directly or indirectly linked to the emplacement of the NAIP

    DataSHIELD:An Ethically Robust Solution to Multiple-Site Individual-Level Data Analysis

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    &lt;b&gt;&lt;i&gt;Background:&lt;/i&gt;&lt;/b&gt; DataSHIELD (Data Aggregation Through Anonymous Summary-statistics from Harmonised Individual levEL Databases) has been proposed to facilitate the co-analysis of individual-level data from multiple studies without physically sharing the data. In a previous paper, we investigated whether DataSHIELD could protect participant confidentiality in accordance with UK law. In this follow-up paper, we investigate whether DataSHIELD addresses a broader range of ethics-related data-sharing concerns. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; Ethics-related data-sharing concerns of Institutional Review Boards, ethics experts, international research consortia and research participants were identified through a literature search and systematically examined at a multidisciplinary workshop to determine whether DataSHIELD proposes mechanisms which can address these concerns. &lt;b&gt;&lt;i&gt;Results:&lt;/i&gt;&lt;/b&gt; DataSHIELD addresses several ethics-related data-sharing concerns related to privacy, confidentiality, and the protection of the research participant's rights while sharing data and after the data have been shared. The data remain entirely under the direct management of the study that collected them. Data processing commands are strictly supervised, and the data are queried in a protected environment. Issues related to the return of individual research results when data are shared are eliminated; the responsibility for return remains at the study of origin. &lt;b&gt;&lt;i&gt;Conclusion:&lt;/i&gt;&lt;/b&gt; DataSHIELD can provide an innovative and robust solution for addressing commonly encountered ethics-related data-sharing concerns.</jats:p

    The 2019 Philippine UHC Act, Pandemic Management and Implementation Implications in a Post-COVID-19 World: A Content Analysis

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    The 2019 Philippine Universal Health Care Act (Republic Act 11223) was set for implementation in January 2020 when disruptions brought on by the pandemic occurred. Will the provisions of the new UHC Act for an improved health system enable agile responses to forthcoming shocks, such as this COVID-19 pandemic? A content analysis of the 2019 Philippine UHC Act can identify neglected and leverage areas for systems’ improvement in a post-pandemic world. While content or document analysis is commonly undertaken as part of scoping or systematic reviews of a qualitative nature, quantitative analyses using a two-way mixed effects, consistency, multiple raters type of intraclass correlation coefficient (ICC) were applied to check for reliability and consistency of agreement among the study participants in the manual tagging of UHC components in the legislation. The intraclass correlation reflected the individuals’ consistency of agreement with significant reliability (0.939, p \u3c 0.001). The assessment highlighted a centralized approach to implementation, which can set aside the crucial collaborations and partnerships demonstrated and developed during the pandemic. The financing for local governments was strengthened with a new ruling that could alter UHC integration tendencies. A smarter allocation of tax-based financing sources, along with strengthened information and communications systems, can confront issues of trust and accountability, amidst the varying capacities of agents and systems

    Instances and connectors : issues for a second generation process language

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    This work is supported by UK EPSRC grants GR/L34433 and GR/L32699Over the past decade a variety of process languages have been defined, used and evaluated. It is now possible to consider second generation languages based on this experience. Rather than develop a second generation wish list this position paper explores two issues: instances and connectors. Instances relate to the relationship between a process model as a description and the, possibly multiple, enacting instances which are created from it. Connectors refers to the issue of concurrency control and achieving a higher level of abstraction in how parts of a model interact. We believe that these issues are key to developing systems which can effectively support business processes, and that they have not received sufficient attention within the process modelling community. Through exploring these issues we also illustrate our approach to designing a second generation process language.Postprin
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