Trophic ecology of three echinoderms in deep waters of the Weddell Sea (Antarctica)

Unidad de excelencia María de Maeztu MdM-2015-0552In the Southern Ocean, the trophic ecology of deep-sea communities is probably one of the most neglected fields in the discipline. In the present study, the trophic position and energy storage-mobilization of 3 different deep-sea echinoderms living in the Weddell Sea (around 1500 m depth) were investigated with indirect tools (i.e. stable isotopes, carbohydrate-lipid-protein balance, and free fatty acid [FFA] contents). The stalked crinoid Dumetocrinus antarcticus, the holothurian Rhipidothuria racovitzai, and the ophiuroid Ophiura carinifera were sampled in spring 2003 during a Polarstern cruise. We found that stable isotopes were in line with previous results of other species (δ¹³C ranging from -24.3‰ to -26.5‰; δ¹⁵N ranging from 6.8‰ to 7.9‰), showing similarities in the trophic position of the 3 echinoderms. The capability to store energy by these 3 organisms is conspicuous and different, e.g. from 18 to 45% of the organic matter (OM) consists of lipids. The capability to mobilize energy in the form of carbohydrates and FFAs among species was also very different (e.g. biomolecules ranging from 9 to 22 µg carbohydrates mgOM⁻¹ and from 4 to 39 µg FFA mgOM⁻¹). It is suggested that even if the trophic level is similar in the 3 echinoderms, the strategies to invest the energy inputs in these deep-sea organisms in polar environments may be quite different

The effect of flow speed and food size on the capture efficiency and feeding behaviour of the cold-water coral Lophelia pertusa

The capture efficiency and feeding behaviour of the cold-water coral (CWC) Lophelia pertusa (Linnaeus, 1758) were investigated considering: (1) different food types, (2) different food sizes and (3) different current speeds and temperatures. This study used two different multifactorial experimental approaches: (1) Corals were subjected to three different flow speeds (2, 5 and 10 cm s− 1) in 5 l volume tanks, and three different food types (alive zooplankton, alive algae, and dry particulate organic carbon) were offered to the corals under each current regime, analysing the capture rates of the corals under these different flow velocities. (2) In a flume, the feeding behaviour of the coral polyps was studied under different current speed regimes (1, 7, 15 and 27 cm s− 1) and a temperature change over a range of 8–12 °C. The obtained results confirm that low flow speeds (below 7 cm s− 1) appear optimal for a successful prey capture, and temperature did not have an effect on polyp expansion behaviour for L. pertusa. In conclusion, flow speeds clearly impact food capture efficiency in L. pertusa, with zooplankton predominantly captured prey at low flow velocities (2 cm s− 1) and phytoplankton captured at higher flow velocities of 5 cm s− 1. This split in capture efficiency may allow corals to exploit different food sources under different tidal and flow conditionsVersión del editor2,263

Low in‑hospital mortality rate in patients with COVID‑19 receiving thromboprophylaxis: data from the multicentre observational START‑COVID Register

Abstract COVID-19 infection causes respiratory pathology with severe interstitial pneumonia and extra-pulmonary complications; in particular, it may predispose to thromboembolic disease. The current guidelines recommend the use of thromboprophylaxis in patients with COVID-19, however, the optimal heparin dosage treatment is not well-established. We conducted a multicentre, Italian, retrospective, observational study on COVID-19 patients admitted to ordinary wards, to describe clinical characteristic of patients at admission, bleeding and thrombotic events occurring during hospital stay. The strategies used for thromboprophylaxis and its role on patient outcome were, also, described. 1091 patients hospitalized were included in the START-COVID-19 Register. During hospital stay, 769 (70.7%) patients were treated with antithrombotic drugs: low molecular weight heparin (the great majority enoxaparin), fondaparinux, or unfractioned heparin. These patients were more frequently affected by comorbidities, such as hypertension, atrial fibrillation, previous thromboembolism, neurological disease,and cancer with respect to patients who did not receive thromboprophylaxis. During hospital stay, 1.2% patients had a major bleeding event. All patients were treated with antithrombotic drugs; 5.4%, had venous thromboembolism [30.5% deep vein thrombosis (DVT), 66.1% pulmonary embolism (PE), and 3.4% patients had DVT + PE]. In our cohort the mortality rate was 18.3%. Heparin use was independently associated with survival in patients aged ≥ 59 years at multivariable analysis. We confirmed the high mortality rate of COVID-19 in hospitalized patients in ordinary wards. Treatment with antithrombotic drugs is significantly associated with a reduction of mortality rates especially in patients older than 59 years

Measurement ultrasonographic of renal corticomedullary correlation in dogs

Através do ultra-som, um método de diagnóstico seguro e preciso, podemos estabelecer a relação córtico-medular (RCM) renal avaliando o volume da cortical e da medular acrescentando uma avaliação quantitativa ao método usado nas interpretações ultra-sonográficas, que ainda são de caráter qualitativa (subjetiva) e dependem da habilidade, do equipamento e da experiência do médico veterinário que estará fazendo o exame. Utilizamos 30 animais de diferentes raças, com idades entre 1 e 9 anos, machos e fêmeas, com pesos na faixa de 9 até 40 Kg, provenientes de clínicas veterinárias particulares. Todos passaram por exames clínico e físico, mostrando-se sadios e sem histórico de doença ou problemas renais, o que foi confirmado através de exames laboratoriais. Após as aferições por ultra-som as medidas foram colocadas em fórmulas, que deram os volumes de córtex e medula, seguindo então para uma relação mais precisa córtex/medula. Os resultados mostraram que os valores de RCM vão de 2,26 a 3,33 independentemente do volume renal, sexo, peso e idade, sendo estas variantes de baixa significância com a relação córtico-medularThrough the ultrasound, a insurance and exact diagnostic, we can establish renal corticomedullary correlation (RCM) evaluating the volume of the cortical and medullary adding a quantitative evaluation to the used method in the interpretations ultrasonographics, that still are of qualitative character (subjective) and depend on the ability, the equipment and the experience of the medical veterinarian who will be making the examination. We use 30 animals of different races, with ages between 1 and 9 years, males and females, with weights in the band of 9 up to 40 kg, proceeding from clinical particular veterinarians. All had passed for examinations clinical and physical, revealing healthy and without description of illness or renais problems, what it was confirmed through laboratoriais examinations. After the gaugings for ultrasound the measures had been placed in formulas, which had given to the volumes of cortex and medullary, following then for a more necessary corticomedullary correlation. The results had shown that the values of RCM independently go of 2,26 the 3,33 of the renal volume, sex, weight and age, being these variants of low significance with the corticomedullary correlation

Measurement ultrasonographic of renal corticomedullary correlation in dogs

Através do ultra-som, um método de diagnóstico seguro e preciso, podemos estabelecer a relação córtico-medular (RCM) renal avaliando o volume da cortical e da medular acrescentando uma avaliação quantitativa ao método usado nas interpretações ultra-sonográficas, que ainda são de caráter qualitativa (subjetiva) e dependem da habilidade, do equipamento e da experiência do médico veterinário que estará fazendo o exame. Utilizamos 30 animais de diferentes raças, com idades entre 1 e 9 anos, machos e fêmeas, com pesos na faixa de 9 até 40 Kg, provenientes de clínicas veterinárias particulares. Todos passaram por exames clínico e físico, mostrando-se sadios e sem histórico de doença ou problemas renais, o que foi confirmado através de exames laboratoriais. Após as aferições por ultra-som as medidas foram colocadas em fórmulas, que deram os volumes de córtex e medula, seguindo então para uma relação mais precisa córtex/medula. Os resultados mostraram que os valores de RCM vão de 2,26 a 3,33 independentemente do volume renal, sexo, peso e idade, sendo estas variantes de baixa significância com a relação córtico-medularThrough the ultrasound, a insurance and exact diagnostic, we can establish renal corticomedullary correlation (RCM) evaluating the volume of the cortical and medullary adding a quantitative evaluation to the used method in the interpretations ultrasonographics, that still are of qualitative character (subjective) and depend on the ability, the equipment and the experience of the medical veterinarian who will be making the examination. We use 30 animals of different races, with ages between 1 and 9 years, males and females, with weights in the band of 9 up to 40 kg, proceeding from clinical particular veterinarians. All had passed for examinations clinical and physical, revealing healthy and without description of illness or renais problems, what it was confirmed through laboratoriais examinations. After the gaugings for ultrasound the measures had been placed in formulas, which had given to the volumes of cortex and medullary, following then for a more necessary corticomedullary correlation. The results had shown that the values of RCM independently go of 2,26 the 3,33 of the renal volume, sex, weight and age, being these variants of low significance with the corticomedullary correlation

Biomarkers of bentho-pelagic coupling in antarctica: a spatio-temporal comparison in the weddell sea

La Antártida es una masa de tierra y hielo rodeada por un mar con una plataforma continental profunda, caracterizado por temperaturas bajas y bastante constantes. La estacionalidad de luz y la capa de hielo son los responsables del aumento de la producción primaria de fitoplancton en primavera-verano y del flujo vertical de materia orgánica particulada (MOP), compuesto por fitoplancton fresco, excrementos del zooplancton y detritus. Los suspensivoros, así como otros organismos sésiles y vágiles, adaptaron sus estrategias de alimentación a estos pulsos de MOP. Estos organismos componen una comunidad bentónica muy diversa, aun siendo su fuente de alimento similar. Las condiciones ambientales más constantes y la alta productividad en las temporadas de primavera y verano provocan diferentes morfologías, tipos de alimentación, almacenamiento de energía y estrategias reproductivas, expresadas en una gran diversidad presente en la comunidad macrobentónica. La relación de estos organismos bentónicos y la dinámica de los alimentos son muy complejos y en gran parte desconocidos, teniendo múltiples variantes. Junto a los ecosistemas de aguas profundas, los ecosistemas bentónicos polares de la Antártida y del Ártico son difíciles de muestrear y observar. Sin embargo, el estudio del acoplamiento bento-pelágico es necesario para entender cómo los ecosistemas de la Antártida van a tolerar la transformación en curso debido principalmente al rápido cambio climático detectado en algunas zonas. Es de vital importancia entender las relaciones tróficas, cuales son las fuentes de materia orgánica que contribuyen a la dieta y cómo los organismos bentónicos adquieren e invierten la energía en función de su nivel trófico. El principal objetivo de este trabajo ha sido estudiar las variaciones de la respuesta espacio-temporal del bentos, ocasionada debido a los cambios de la disponibilidad de la materia orgánica, examinando las características ambientales y sus efectos sobre las comunidades bentónicas en el mar de Weddell (lado este del Mar de Weddell - Austassen-Kapp Norvegia y Península Antártica - estrecho de Bransfield y Larsen A, B y C). Una combinación de marcadores tróficos (isótopos estables, ácidos grasos, y el balance bioquímico (proteína-carbohidrato-lípido)) se utilizó a tal fin. Estos marcadores integran señales tróficas, lo que permite una comparación espacial y temporal de la acumulación de materia orgánica y de almacenamiento de energía en suspensivoros bentónicos. La ecología trófica de dieciséis representativas especies de invertebrados bentónicos fue estudiada y produjo una mejor interpretación del acoplamiento bento-pelágico en este desconocido ambiente. Las siete especies de gorgonias (Primnoisis sp., Fannyella nodosa, Ainigmaptilon antarcticum, Notisis sp., Primnoella sp., Dasystenella sp. y Thouarella sp.) recolectadas en el otoño de 2000 en Austasen, mostraron casi los mismos valores de isótopos estables del fitodetritus presente en las llamadas “green carpets" (acumulaciones de fitoplancton provenientes de la parte superficial de la columna de agua) y del microzooplancton. La dieta está por tanto basada en material sedimentado y re-suspendido, apoyando en parte la hipótesis de que algunos suspensivoros afrontan con éxito el invierno antártico, gracias a esta fuente de alimentos de larga duración. El balance bioquímico indicó un almacenamiento de energía diferente dependiendo de la especie y, posiblemente, de su estrategia reproductora. Para entender el papel de la estacionalidad en las comunidades bentónicas, se estudió la ecología trófica del alcionario Anthomastus bathyproctus a finales del otoño de 2000 y finales del verano de 2011 en la Península Antártica. La presa principal (el tunicado Salpa thompsoni) también se estudió en ambas épocas del año para entender su papel en el balance de energía y la contribución a la dieta del suspensivoro pasivo. Las principales presas del alcionario eran diferentes cuando se compararon ambas temporadas. Aunque no se detectó estacionalidad en los marcadores tróficos de S. thompsoni, A. bathyproctus mostró una dieta predominantemente carnívora a finales de verano en comparación con finales de otoño, más basada en el omnivorismo. Los valores de los lípidos en S. thompsoni fueron más de tres veces mayores en otoño respecto al verano, mientras que los de A. bathyproctus eran prácticamente los mismos. Se sugiere que este cnidario tiene una estrategia trófica ligada a la llegada a pulsos (intermitente) de alimentos, detectándose un claro patrón trófico estacional. La última pregunta propuesta en la presente Tesis es el efecto potencial del cambio climático en la ecología trófica de varios organismos bentónicos (detritívoros y alimentadores de suspensión) en el área de Larsen, un sitio recién abierto al ciclo estacional de la productividad primaria en la Península Antártica, debido al colapso de la barrera de hielo permanente. El estudio de nueve organismos bentónicos (Ophiura carinifera, Ophioperla koehleri, Ophionotus victoriae, Pyura bouvetensis, Cnemidocarpa verrucosa, Primnoisis sp., Protelpidia murrayi, Bathyplotes fuscivinculum y Molpadia musculus), mostró un gradiente en el origen de los alimentos potencialmente disponibles. Cuando comparamos la zona de Larsen (donde recientemente ocurrió la desintegración de la capa de hielo) y la Península Antártica (que nunca tuvo la plataforma de hielo) en verano de 2011, el material sedimentado tiene diferentes valores relacionados con la caída más o menos reciente de la producción primaria (y su abundancia). El material sedimentado es potencialmente parte de la dieta, pero no se encontró una relación directa cuando se analizaron los isótopos estables o los ácidos grasos del sedimento y de los organismos que se alimentan directa o indirectamente de él. Los organismos muestran una dieta omnívora y algunos de ellos incluso una típica dieta carnívora, basada en material reciclado en las zonas Larsen estudiadas, lo que indica que el sistema está en un claro proceso de sucesión y transformación. Dependiendo de la estrategia alimentaria, hubo considerables diferencias en la capacidad de almacenar reservas en forma de lípidos, siendo las especies vágiles las que acumulan menos reservas (lípidos). Se deduce gracias al presente estudio que estas herramientas pueden ser muy útiles para entender cómo la sucesión de las diferentes etapas de una zona transformada por el cambio en la cubierta de hielo afectará a la ecología trófica de los organismos epibentónicos. Todos los resultados han contribuido a una mejor comprensión de la ecología trófica de la comunidad bentónica, y sus estrategias para sobrevivir en un panorama de cambio climático que modifica rápidamente las comunidades, especialmente en las zonas más afectadas, como la Península Antártica.Antarctica is a frozen continent surrounded by the sea with a deep continental platform characterized by constantly low temperatures. The seasonality of light and ice cover is responsible for the increase of the primary production of phytoplankton in spring-summer and the vertical flux of particulate organic matter (POM), composed by living fresh phytoplankton, faecal pellets and detritus. Suspension feeders and other sessile and vagile organisms have adapted their feeding strategies to these POM pulses. These organisms compose a highly diverse benthic community, regardless their original food source is either similar or not. The rather constant environmental conditions and the high productivity in the spring and summer seasons allow different morphological, feeding, energy storage and reproductive strategies, expressed in a highly diverse macrobenthic assemblages. The relationship of these benthic organisms and food dynamics is very complex and largely unknown, having multiple variants. Together with the deep-sea ecosystems, Antarctic and Arctic polar benthic ecosystems are difficult to reach, but the study of benthic-pelagic coupling is necessary to understand how Antarctic ecosystems will tolerate the ongoing transformation due mainly to the rapid climate change detected in some areas. It is vital to understand the trophic relationships, what are the sources of organic matter to the diet of the benthos and how the organisms acquire and invest the energy as a function of their trophic level. The main objective of this work was studying the variations of the spatial-temporal response of benthos to the availability of organic matter changes, examining the environmental characteristics and their effects on the benthic communities in the Weddell Sea (Eastern Weddell Sea - Austassen-Kapp Norvegia and Antarctic Peninsula - the Bransfield Strait and Larsen A, B and C). In order to hypostatize this study, a combination of trophic markers was used, such as: stable isotopes, fatty acids, and biochemical balance (protein-carbohydrate-lipid). These markers integrate trophic signals, allowing a spatial and temporal comparison of organic matter accumulation and energy storage in benthic suspension feeders. The trophic ecology of sixteen representative species of benthic invertebrates was studied and producing a better interpretation of benthic-pelagic coupling of the still poorly known ecosystem. The seven species of gorgonians (Primnoisis sp, Fannyella nodosa, Ainigmaptilon antarcticum, Notisis sp., Primnoella sp., Dasystenella sp. and Thouarella sp.) collected in the autumn of 2000 in Austasen, showed almost the same values of stable isotopes derived from the phytodetritus in the so called "green carpets" and the microzooplankton. The diet seemed to be based on sunk and re-suspended material, supporting the hypothesis that some suspension feeders deal successfully with the Antarctic winter thanks to this long-lasting food source. The biochemical balance indicated a different energy storage depending on the species and possibly its reproductive traits. To understand the role of seasonality in benthic communities, the trophic ecology of the Alcyonarian Anthomastus bathyproctus in the late autumn 2000 and late summer 2011 in the Antarctic Peninsula was investigated. The main prey (the tunicate Salpa thompsoni) was considered in both seasons to understand its role in the energy budget and preferences of this passive suspension feeder. The main preys of the Alcyonarian were different when both seasons were compared. Although no seasonality was detected for S. thompsoni trophic markers, A. bathyproctus showed a predominantly carnivorous diet in late summer compared to late autumn, in which the signals belonged to a more omnivorous diet. The lipid values in S. thompsoni were more than three times higher in autumn than in summer, whilst those of A. bathyproctus were practically the same. A food pulse trophic strategy is suggested for this cnidarian, detecting a trophic seasonal pattern. The last question proposed in the present Thesis is the potential effect of climate change in the trophic ecology of several benthic organisms (detritivores and suspension feeders) in the Larsen area, a recently opened to the considered normal cycle of the primary productivity in the Antarctic Peninsula due to the permanent ice shelf collapse. The study of nine benthic organisms (Ophiura carinifera, Ophioperla koehleri, Ophionotus victoriae, Pyura bouvetensis, Cnemidocarpa verrucosa, Primnoisis sp., Protelpidia murrayi, Bathyplotes fuscivinculum and Molpadia musculus), showed a gradient of food sources comparing the area of Larsen (where recent disintegration of the ice cover occur) and the Antarctic Peninsula (which never had ice shelf) in summer of 2011. The sedimented material was potentially part of the diet, but not a direct relationship between the sediment and the organisms on stable isotopes or fatty acids markers was found. The organisms show an omnivore diet and some of them even present a typical carnivorous diet, based on non-fresh or reworked material in the Larsen areas studied, indicating that the system is in a clear successional process. On the other hand, depending on the feeding and life style strategy, there were considerable differences in the ability to store reserves in the lipids form, being the vagile species those that apparently accumulate less energy storage reserves (lipids). The present study indicates that these tools may be very useful to understand how the different succession stages of a transformed area due to the change in ice cover will affect the trophic ecology of the epibenthic organisms in the White Continent. All the results contributed to a better understanding of the trophic ecology of the benthic community and their strategies to survive in a climate change panorama that has been rapidly and significantly changing those communities in the last decades, especially in the most affected areas like the Antarctic Peninsula