1,002 research outputs found

    Shifts in marine invertebrate bacterial assemblages associated with tissue necrosis during a heat wave

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    Marine heat waves (MHWs) are periods of extremely high seawater temperature that affect marine ecosystems in several ways. Anthozoans (corals and gorgonians) and Porifera (sponges) are usually among the taxa most affected by MHWs. Both are holobiont entities that form complex interactions with a wide range of microbes, which are an essential part of these organisms and play key roles in their health status. Here, we determine microbial community changes suffered in two corals (Cladocora caespitosa and Oculina patagonica), one gorgonian (Leptogorgia sarmentosa) and one sponge (Sarcotragus fasciculatus) during the 2015 MHW. The microbial communities were different among hosts and displayed shifts related to host health status, with a higher abundance in necrosed tissues of Ruegeria species or of potential pathogens like Vibrio. We also carry out a meta-analysis using 93 publicly accessible 16S rRNA gene libraries from O. patagonica, C. caespitosa and L. sarmentosa to establish a Mediterranean core microbiome in these species. We have identified one Ruegeria OTU that maintained a stable and consistent association with these species, which was also related to tissue necrosis in their hosts. Therefore, Ruegeria sp. could play an important and still underexplored role in the health status of its hosts.This work has been carried out within the CIESM project “Tropical Signals” and it was funded by the European Union’s framework program Horizon 2020 (LEIT-BIO-2015-685474, Metafluidics, to JA)

    Formability of the 5754-aluminum alloy deformed by a modified repetitive corrugation and straightening process

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    Sheets of 5754-aluminum alloy processed by a modified repetitive corrugation and straightening (RCS) process were tested in order to measure their formability. For this purpose, forming limit curves were derived. They showed that the material forming capacity decreased after being processed by RCS. However, they kept good formability in the initial stages of the RCS process. The formability study was complemented with microstructural analysis (derivation of texture) and mechanical tests to obtain the strain-rate sensitivity. The texture analysis was done by employing X-ray diffraction, obtaining pole figures, and the orientation distribution function. It was noticed that the initial texture was conserved after successive RCS passes, but the intensity dropped. RCS process did not induce ß-fiber, contrary to common deformation process. The strain-rate sensitivity coefficient was measured through tensile tests at different temperatures and strain rates; the coefficient of the samples processed after one and two passes were still relatively high, indicating the capacity to delay necking, in agreement with the good formability observed in the initial passes of the RCS processPeer ReviewedPostprint (published version

    Tri-leafl et mitral valves – when lightning strikes thrice

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    Mitral valves are well known to be bi-leaflet structures with attachments from both leaflets (anterior and posterior) to both papillary muscles (anterolateral and posteromedial). Congenital abnormalities of the mitral valve, although well described, are quite rare. These abnormalities can involve either the leaflet (cleft mitral valve) or the subvalvular apparatus (parachute mitral valve) or even occur as accessory mitral valve tissue (accessory mitral valve leaflet). These can occur in isolation, or in association with other congenital abnormalities. A tri-leaflet mitral valve is a novel echocardiographic finding that has only been described in 6 patients in 4 different case reports.(1-4) Wereport on 3 patients recently found to have trileaflet mitral valves in the setting of atrioventricular concordance and normal offset of the AV valves at our out-patient clinic

    COVID-19 and cardiovascular imaging: a guide for the practising clinician

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    In the ongoing COVID-19 pandemic, patients with cardiac disease have been the worst afflicted with a high mortality. Cardiac imaging forms an integral part of the armamentarium in the management of these patients. This review focuses on providing a general guide to cardiac imaging in the COVID-19 context for the practising clinician in Africa. These recommendations are likely to be modified as further data emerge on the effect of the SARS-CoV-2 virus on the cardiovascular system

    Interobserver and Intertest Agreement in Telemedicine Glaucoma Screening with Optic Disk Photos and Optical Coherence Tomography

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    Glaucoma; Retinògrafs; TelemedicinaGlaucoma; Retinógrafos; TelemedicinaGlaucoma; Retinographs; TelemedicinePurpose: To evaluate interobserver and intertest agreement between optical coherence tomography (OCT) and retinography in the detection of glaucoma through a telemedicine program. Methods: A stratified sample of 4113 individuals was randomly selected, and those who accepted underwent examination including visual acuity, intraocular pressure (IOP), non-mydriatic retinography, and imaging using a portable OCT device. Participants’ data and images were uploaded and assessed by 16 ophthalmologists on a deferred basis. Two independent evaluations were performed for all participants. Agreement between methods was assessed using the kappa coefficient and the prevalence-adjusted bias-adjusted kappa (PABAK). We analyzed potential factors possibly influencing the level of agreement. Results: The final sample comprised 1006 participants. Of all suspected glaucoma cases (n = 201), 20.4% were identified in retinographs only, 11.9% in OCT images only, 46.3% in both, and 21.4% were diagnosed based on other data. Overall interobserver agreement outcomes were moderate to good with a kappa coefficient of 0.37 and a PABAK index of 0.58. Higher values were obtained by experienced evaluators (kappa = 0.61; PABAK = 0.82). Kappa and PABAK values between OCT and photographs were 0.52 and 0.82 for the first evaluation. Conclusion: In a telemedicine screening setting, interobserver agreement on diagnosis was moderate but improved with greater evaluator expertise.The study has been funded by the Fondo de InvestigacionesSanitarias of the Spanish Ministry of Health (PI15/00412)

    Sessile Biofouling on Electrolytic Carbonated Structures: Stages of Colonization and Succession

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    The ecological succession has been widely studied by means of biofouling assemblages among different substrates, and mainly targeted in early stages on artificial ones. The present study focuses on biofouling that colonizes carbonated structures, a material similar to the natural substrate produced by the electrolysis of seawater, which is relatively very little studied. We have observed the colonization of sessile macrofouling of the port of Alicante (SE Spain, Western Mediterranean) on two types of substrates (electrolytic carbonated and steel) over 12 months of succession. The assemblages of both substrates have been analyzed by means of diversity indexes and multivariate analysis (PERMANOVA and SIMPER) in order to see the differences over time. The carbonated substrate has presented a community with higher values of biological diversity, structure and complexity, although the differences in species composition between substrates are not evident during all immersion periods. Thus, these results seem to indicate that, even after 12 months of immersion, communities are still in a dynamic successional stage.This research forms part of the ThinkInAzul program and was funded by Ministerio de Ciencia e Innovación with funding from European Union NextGenerationEU (PRTR-C17.I1) and by Generalitat Valenciana (THINKINAZUL/2021/014)

    Optimización superficial de alambres de ortodoncia de Ni-Ti superelástico mediante nitruración gaseosa. Parte II: Cuantificación de la mejora de la nanodureza y el coeficiente de fricción

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    La mejora del deslizamiento entre el alambre de ortodoncia y el bracket es uno de los principales problemas en la terapia ortodoncica. Este estudio presenta la nitruración gaseosa como un eficaz método de mejora del deslizamiento de los alambres ortodóncicos de Ni-Ti superelástico (composiciones cercanas a la equiatómica) respecto al bracket, principal inconveniente de estas aleaciones en la aplicación ortodóncica. Mediante microscopía óptica y electrónica de barrido se comprobó la existencia de una capa superficial nitrurada, así como la morfología de las fases presentes. Asimismo, se realizaron microanálisis químicos de las capas exteriores mediante técnica de energía dispersiva de rayos X. En todas las muestras nitruradas la dureza aumentó con la severidad del tratamiento y se alcanzaron valores de hasta 1111HV en comparación con los valores de 323 HV del alambre sin tratar. Se diseñaron ensayos de tipo pin on disk adaptados a las peculiaridades de los alambres, que mostraron un descenso del coeficiente de fricción. El endurecimiento y mejora de la fricción en la superficie del material se justifican por la formación de las capas nitruradas.Peer Reviewe

    Early colonization of sessile megabenthos on electrolytic carbonated structures (Alicante's harbor, Western Mediterranean)

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    Biofouling in different artificial substrata was done to determine the differences in biofouling assemblages among different substrates. However, studies on biofouling on natural substrates like electrolytic carbonated ones are lacking. These substrates have a great potential for coral reef restoration in tropical areas and for biofilter construction. Thus, this study was done to examine the colonization of sessile macrofouling in the port of Alicante (SE Spain, Western Mediterranean) on two types of substrata: electrolytic carbonated and bare steel (as control) over three months of immersion (October 2019–January 2020). The community diversity was studied through different biotic parameters and abundance of assemblages, and preference of organisms according to their status and functional group (active filter feeders). Univariate and multivariate analyses (PERMANOVA and SIMPER) were also done to examine the differences between carbonate and control substrata. The carbonated substrate had a more structured community and higher abundance, recruitment, and diversity indexes than the bare steel. Moreover, filter feeders (Porifera, Bivalvia, and Ascidiacea) were more abundant, and most of them only appeared in the carbonated substrate. These results show the potential of carbonated structures as biofilters.This study forms part of the ThinkInAzul program and was supported by Ministerio de Ciencia e Innovación with funding from European Union NextGenerationEU (PRTRC17.I1) and by Generalitat Valenciana (THINKINAZUL/2021/014)

    Double atrial heart sound in a patient with 2:1 atrioventricular block

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    CITATION: Pecoraro, A. J., Doubell, A. F. & Herbst, P. G. 2017. Double atrial heart sound in a patient with 2:1 atrioventricular block, SA Heart, 14(1):44-45, doi:10.24170/14-1-1879.The original publication is available at http://www.journals.ac.za/index.php/SAHJNo abstract availablehttp://www.journals.ac.za/index.php/SAHJ/article/view/1879Publisher's versio
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