962 research outputs found

    Estimations of free fatty acids (FFA) as a reliable proxy for larval performance in Mediterranean octocoral species

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    The survival, behavior, and competence period of lecithotrophic larvae depends not only on the energy allocation transferred by maternal colonies, but also on the amount of energy consumed to sustain embryonic, larval, and post-larval development. The objective of the present work is to understand the effect of energy consumption on the performance of lecithotrophic larvae. To this aim, we analysed free fatty acid (FFA) content and composition of the larvae of three Mediterranean octocorals (Corallium rubrum, Eunicella singularis, and Paramuricea clavata) as a proxy for energy consumption. Results showed that C. rubrum larvae consume more FFA than P. clavata, whereas the energy consumed by E. singularis larvae is high but highly variable. These results are in accordance with the larval behavior of these three species, since C. rubrum larvae are characterized by their high swimming activity frequency, P. clavata larvae are almost inactive, and the swimming activity frequency of E. singularis larvae is high, although variable. The differences in FFA composition of the larvae suggest contrasting energetic strategies that could explain the differences in survival and recruitment rates. In fact, high dispersal and recruitment capacities for E. singularis larvae can be inferred from the FFA composition, whereas the high spatial and temporal variability of recruitment observed in C. rubrum may be related to the non-selective transfer of fatty acid (FA) from maternal colonies. Finally, the high recovery rates after mass mortality events observed in P. clavata could be favored by the presence of a specific FA [22:6(n-3)] related to adaptation mechanisms under environmental stresses during the first developmental stages

    Presence and geodynamic significance of Cambro-Ordovician series of SE Karakaram (N. Pakistan)

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    New geological, geochemical and geochronological data from the Southern Karakoram (NE Pakistan) indicate the presence of several unexpectedly old and well preserved units along the Asian margin: (1) a Precambrian basement, displaying a minimum amphibole Ar-Ar age of 651 Ma; (2) a thick Cambro-Ordovician platform-type sedimentary unit overlying the Precam-brian basement. These series are dated by graptolite and crinoid faunas, and are confirmed by concordant 87Sr/86Sr and 13C “ages” of the marbles; (3) a dismembered ophiolitic series formed by slices of metagabbros and metabasalts separated by ultramafic lenses (the Masherbrum Greenstone Complex). The occurrence of such Cambro-Ordovician series overlying a Precambrian basement in south-eastern Karakoram similar to the south-western Karakoram shows that the Karakoram constitutes a continuous tectonic block. The petrology and geochemistry of the Masherbrum Greenstone Complex (mineral chemistry, major and trace element and Sr-Nd isotopic data) are indicative of a supra-subductive environment. The presence of LREE-enriched calc-alkaline rocks [(La/Yb)N = 4.45.6; (Nb/La)N = 0.2-0.3; eNd565 = 5.1-7.1] and LREE-depleted tholeiitic rocks [(La/Yb)N =0.5-1.3; (Nb/La)N = 0.6-0.9; eNd565 = 5.6-7.8] are consistent with arc and back-arc settings, respectively. A high-Mg andesitic dolerite and an OIB-type metabasalt, with lower eNd ratios (eNd565 = 0.5 and 4.5) are in accordance with source heterogeneity beneath the arc. The Masherbrum Greenstone Complex, along with other Cambro-Ordovician central-eastern volcanic series give evidence of a tectonic situation governed by micro-plate convergent-divergent systems with occurrence of arc - back-arc settings during the Lower Palaeozoic, comparable to that of the current SW Pacific area

    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

    Effectiveness of early intervention programs for parents of preterm infants: a meta-review of systematic reviews

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    Background: Various intervention programs exist for parents of preterm babies and some systematic reviews (SRs) have synthesised the evidence of their effectiveness. These reviews are, however, limited to specific interventions, components, or outcomes, and a comprehensive evidence base is lacking. The aim of this meta-review was to appraise and meta-synthesise the evidence from existing SRs to provide a comprehensive evidence base on the effectiveness of interventions for parents of preterm infants on parental and infant outcomes. Methods: We conducted a comprehensive search of the following databases to identify relevant SRs: Cochrane library, Web of science, EMBASE, CINAHL, British Nursing Index, PsycINFO, Medline, ScienceDirect, Scopus, IBSS, DOAJ, ERIC, EPPI-Centre, PROSPERO, WHO Library. Additional searches were conducted using authors’ institutional libraries, Google Scholar, and the reference lists of identified reviews. Identified articles were screened in two stages against an inclusion criteria with titles and abstracts screened first followed by full-text screening. Selected SRs were appraised using the AMSTAR tool. Extracted data using a predesigned tool were synthesised narratively examining the direction of impact on outcomes. Results: We found 11 SRs eligible for inclusion that synthesised a total of 343 quantitative primary studies. The average quality of the SRs was ‘medium’. Thirty four interventions were reported across the SRs with considerable heterogeneity in the structural framework and the targeted outcomes that included maternal-infant dyadic, maternal/parental, and infant outcomes. Among all interventions, Kangaroo Care (KC) showed the most frequent positive impact across outcomes (n = 19) followed by Mother Infant Transaction Program (MITP) (n = 14). Other interventions with most consistent positive impact on infant outcomes were Modified-Mother Infant Transaction Program (M-MITP) (n = 6), Infant Health and Development Program (IHDP) (n = 5) and Creating Opportunities for Parent Empowerment (COPE) (n = 5). Overall, interventions with both home and facility based components showed the most frequent positive impact across outcomes. Conclusions: Neonatal care policy and planning for preterm babies should consider the implementation of interventions with most positive impact on outcomes. The heterogeneity in interventions and outcomes calls for the development and implementation of an integrated program for parents of preterm infants with a clearly defined global set of parental and infant outcomes

    A numerical modelling investigation of the role of diabatic heating and cooling in the development of a mid-level vortex prior to tropical cyclogenesis – Part 1: The response to stratiform components of diabatic forcing

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    Mid-tropospheric mesoscale convective vortices have been often observed to precede tropical cyclogenesis. Moreover, recent cloud-resolving numerical modelling studies that are initialized with a weak cyclonic mid-tropospheric vortex sometimes show a considerable intensification of the mid-level circulation prior to the development of the strong cyclonic surface winds that characterize tropical cyclogenesis. The objective of this two-part study is to determine the processes that lead to the development of a prominent mid-level vortex during a simulation of the transformation of a tropical disturbance into a tropical depression, in particular the role of diabatic heating and cooling. For simplicity simulations are initialized from a quiescent environment. In this first part, results of the numerical simulation are described and the response to stratiform components of the diabatic forcing is investigated. In the second part, the contribution of diabatic heating in convective cells to the development of the mid-level vortex is examined.Results show that after a period of intense convective activity, merging of anvils from numerous cells creates an expansive stratiform ice region in the upper troposphere, and at its base a mid-level inflow starts to develop. Subsequently conservation of angular momentum leads to strengthening of the mid-level circulation. A 12&thinsp;h period of mid-level vortex intensification is examined during which the mid-level tangential winds become stronger than those at the surface. The main method employed to determine the role of diabatic forcing in causing the mid-level inflow is to diagnose it from the full physics simulation and then impose it in a simulation with hydrometeors removed and the microphysics scheme turned off. Removal of hydrometeors is achieved primarily through artificially increasing their fall speeds 3&thinsp;h prior to the 12&thinsp;h period. This results in a state that is in approximate gradient wind balance, with only a weak secondary circulation. Then, estimates of various components of the diabatic forcing are imposed as source terms in the thermodynamic equation in order to examine the circulations that they independently induce. Sublimation cooling at the base of the stratiform ice region is shown to be the main factor responsible for causing the strong mid-level vortex to develop, with smaller contributions from stratiform heating aloft and low-level melting and evaporation. This contrasts with the findings of previous studies of mid-latitude vortices that indicate sublimation plays a relatively minor role. An unanticipated result is that the central cool region that develops near the melting level is to a large degree due to compensating adiabatic ascent in response to descent driven by diabatic cooling adjacent to the central region, rather than in situ diabatic cooling. The mid-level inflow estimated from stratiform processes is notably weaker than for the full physics simulation, suggesting a moderate contribution from diabatic forcing in convective cells.</p

    International Nuclear Medicine Consensus on the Clinical Use of Amyloid Positron Emission Tomography in Alzheimer's Disease.

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    Alzheimer's disease (AD) is the main cause of dementia, with its diagnosis and management remaining challenging. Amyloid positron emission tomography (PET) has become increasingly important in medical practice for patients with AD. To integrate and update previous guidelines in the field, a task group of experts of several disciplines from multiple countries was assembled, and they revised and approved the content related to the application of amyloid PET in the medical settings of cognitively impaired individuals, focusing on clinical scenarios, patient preparation, administered activities, as well as image acquisition, processing, interpretation and reporting. In addition, expert opinions, practices, and protocols of prominent research institutions performing research on amyloid PET of dementia are integrated. With the increasing availability of amyloid PET imaging, a complete and standard pipeline for the entire examination process is essential for clinical practice. This international consensus and practice guideline will help to promote proper clinical use of amyloid PET imaging in patients with AD

    Effects of diet on the outcomes of rheumatic and musculoskeletal diseases (RMDs): systematic review and meta-analyses informing the 2021 EULAR recommendations for lifestyle improvements in people with RMDs

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    BackgroundA EULAR taskforce was convened to develop recommendations for lifestyle behaviours in rheumatic and musculoskeletal diseases (RMDs). In this paper, the literature on the effect of diet on the progression of RMDs is reviewed.MethodsSystematic reviews and meta-analyses were performed of studies related to diet and disease outcomes in seven RMDs: osteoarthritis (OA), rheumatoid arthritis (RA), systemic lupus erythematosus, axial spondyloarthritis, psoriatic arthritis, systemic sclerosis and gout. In the first phase, existing relevant systematic reviews and meta-analyses, published from 2013 to 2018, were identified. In the second phase, the review was expanded to include published original studies on diet in RMDs, with no restriction on publication date. Systematic reviews or original studies were included if they assessed a dietary exposure in one of the above RMDs, and reported results regarding progression of disease (eg, pain, function, joint damage).ResultsIn total, 24 systematic reviews and 150 original articles were included. Many dietary exposures have been studied (n=83), although the majority of studies addressed people with OA and RA. Most dietary exposures were assessed by relatively few studies. Exposures that have been assessed by multiple, well conducted studies (eg, OA: vitamin D, chondroitin, glucosamine; RA: omega-3) were classified as moderate evidence of small effects on disease progression.ConclusionThe current literature suggests that there is moderate evidence for a small benefit for certain dietary components. High-level evidence of clinically meaningful effect sizes from individual dietary exposures on outcomes in RMDs is missing
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