Adaptación al consumo de alimento inerte a alevines de “Doncella” Pseudoplatystoma punctifer (Siluriformes: Pimelodidae)

Publicación a texto completo no autorizada por el autorDetermina el efecto de dos tiempos de inicio y cuatros tratamientos de alimentación sobre el crecimiento, supervivencia y canibalismo en la adaptación al consumo de dietas secas de alevines de doncella Pseudoplatystoma punctifer. Las larvas fueron alimentadas inicialmente con nauplios de Artemia desde los tres días post fertilización (dpf). Se planteó cuatro tratamientos de alimentación: tres alimentos húmedos (T1= flan balanceado, T2= flan balanceado + péptidos, T4= hígado de res) y un alimento seco (T3= alimento seco). Los cuatro tratamientos fueron sustituyendo gradualmente los nauplios de Artemia (primer proceso de adaptación) y posteriormente fueron sustituidos en el caso de las dietas húmedas (T1, T2 y T4) por un alimento seco comercial (segundo proceso de adaptación). Este proceso de sustitución se realizó a dos tiempos de inicio de adaptación I1 (21,2 mm; 20 dpf) y I2 (28,8 mm; 25 dpf). Se realizó con ANOVA y ANOVA factorial. Los resultados muestran las más altas supervivencias para los tratamientos FB (45,2 ± 5%), FBP (42.4 ± 5,4%) y HG (42,9 ± 3,1%) al segundo tiempo de inicio, y la más baja para la dieta AS al primer tiempo de inicio (3.9 ± 1.4%), así como la mayor ocurrencia de canibalismo tipo II. La adaptación se logra en todos los tratamientos de alimentación, siendo más eficiente FB, FBP y HG (húmedas) a nivel de supervivencia en el segundo tiempo de adaptación, pero con la desventaja del incremento del canibalismo.Tesi

Monitoring under ice phyto- and zooplankton blooms with the Nereid Under Ice remotely operated vehicle

The perennially ice-covered Central Arctic is changing rapidly due to extensive sea-ice retreat and the loss of multiyear ice. The thinning of the ice allows more light to reach the water column enhancing productivity. These changes in the under ice ecosystem can lead to under-ice phytoplankton blooms which may increase grazing and carbon export. However, our knowledge of the interactions between sea ice, sub-ice and under-ice communities is still poor, especially in high latitudes. A key limitation is observations of the undisturbed under-ice flora and fauna. To address this gap in observations, the Nereid Under Ice remotely operated vehicle (NUI) was developed, equipped with thin optical fibre and acoustic navigation to explore under-ice environments at distances up to 20 km away from research vessels from which it is deployed. This vehicle can accommodate various interdisciplinary payloads including HD video cameras, CTD and biological sensor packages including chlorophyll fluorometers, CDOM optical sensors and optical nitrate sensors. Research capabilities of NUI were tested during the RV Polarstern PS86 expedition to the Aurora Vent field, at 83ºN 6°W north-east of Greenland. From 12 to 30 July 2014 the evolution of a phytoplankton bloom below 2m thick multiyear ice was followed. Video footage obtained with NUI directly below the ice showed the development of algal mats at the bottom of the ice floe and a succession of zooplankton blooms presumably causing a decline of the phytoplankton bloom. Polar copepods, ctenophores and appendicularia could be identified forming dense biomasses underneath the ice. From NUI’s chlorophyll, CDOM and nitrate profiles, steep gradients of high biogeochemical activity were detected in the mixed layer (upper 6-15 m), which could not be observed by the ship-deployed CTD. These structures were identified as layers of sinking particles with different optical characteristics. This poster summarizes the advantages of robotic observations over classical ship-based sampling for the study of under ice communities. In vivo observations of phyto- and zooplankton communities are needed to better assess the impacts of changing sea-ice conditions on under ice organisms

Caracterización hematológica de Astronotus ocellatus (Cichliformes: Cichlidae)

The aim of this study was to characterize the hematological parameters of Astronotus ocellatus and to determine possible correlations between variables. Blood samples were collected from 15 specimens (weight: 109.43 ± 22.9 g, total length: 15.43 ± 1.28 cm), kept in concrete tanks and fed with a commercial diet extruded at 42% crude protein. Blood samples were collected by puncture of the caudal vessel using syringes with EDTA (10%). The erythrocytic values were: haematocrit 24.5 ± 1.2%, haemoglobin 8.8 ± 2.4 g/dl; erythrocytes 1.10 ± 0.10 x 106/μl, MCV 222.1 ± 41.0 fl, MCHC 36.7 ± 10.4 g/dl. Leukocyte parameters were total leukocytes 7.3 ± 2.6 x103/μl, lymphocytes 67.3 ± 7.6%, monocytes 4.13 ± 1.4%, eosinophils 27.5 ± 8.9%, neutrophils 1.08 ± 1.3%. In serum biochemistry: total protein 3.44 ± 1.1 g/dl, glucose 64.39 ± 28.8 mg/dl, cholesterol 253.4 ± 91.2 mg/dl. Positive correlation was observed between haemoglobin and MCHC. Also, negative correlation between bodyweight and body length with the number of erythrocytes. The values found are within the range reported for this fish species.El estudio tuvo como objetivo caracterizar los parámetros hematológicos de Astronotus ocellatus y determinar posibles correlaciones entre variables. Se colectaron muestras de sangre de 15 especímenes (peso: 109.43 ± 22.9 g; longitud total: 15.43 ± 1.28 cm), mantenidos en tanques de concreto. Los peces recibieron una alimentación con dieta comercial extruida, que contenía 42% de proteína bruta. La extracción de sangre se realizó mediante punción del vaso caudal usando jeringas con EDTA (10%). Los valores obtenidos de la serie eritrocítica fueron: hematocrito 24.5 ± 1.2%, hemoglobina 8.8 ± 2.4 g/dl, eritrocitos totales 1.10 ± 0.10 x106/µl, VCM 222.1 ± 41.0 fl, y CHCM 36.7 ± 10.4 g/dl. En la serie leucocítica se identificaron: leucocitos totales 7.3 ± 2.6 x103/µl, linfocitos 67.3 ± 7.6%, monocitos 4.13 ± 1.4%, eosinófilos 27.5 ± 8.9% y neutrófilos 1.08 ± 1.3%. Para bioquímica sérica fueron: proteína total 3.44 ± 1.1 g/dl, glucosa 64.39 ± 28.8 mg/dl y colesterol 253.4 ± 91.2 mg/dl. Se registró correlación positiva entre hemoglobina-CHCM y correlación negativa entre peso y longitud con número de eritrocitos totales. La mayoría de los valores encontrados están dentro del rango reportado para esta especie

VALORES HEMATOLÓGICOS Y BIOQUÍMICOS DE JUVENILES DE PAICHE Arapaima gigas EN CULTIVO INTENSIVO

El objetivo de este estudio fue determinar los valores hematológicos y bioquímicos de juveniles de paiche Arapaima gigas criados en cultivo intensivo. Los juveniles (peso inicial 71,72 ± 23,89 g y longitud inicial 20,45 ± 1,42 cm) fueron estabulados en cuatro tanques de 900 Lcon recirculación de agua (temperatura 25,90 -1 -1 ± 0,44 °C; oxígeno disuelto 1,43 ± 1,12 mg L ; pH 6,74 ± 0,2; nitrito 0,41 ± 0,62 mg L y amonio 16,17 ± 9,03 -1 mg L ) por un periodo de 154 días. Durante los primeros 40 días, se mantuvieron a una densidad inicial de 200 -3 -3 peces m y posteriormente a 150 peces m . La alimentación se realizó tres veces al día con un alimento ® balanceado (Aquatech , Naltech, Lima, Perú; composición proximal: 42% proteína, 10% lípidos, 12% cenizas; tamaño de partícula: 2,5 y 4 mm). Las muestras de sangre se obtuvieron en cinco muestreos (124, 137, 138, 142 y 143 días) con jeringas descartables conteniendo EDTA al 10% para la determinación de los valores hematológicos y bioquímicos. Al final del experimento, los peces alcanzaron un peso promedio de 832,6 ± 173,1 g y 47,4 ± 2,4 cm de longitud total con una supervivencia de 91,9%. Los valores hematológicos 3 -1 y bioquímicos promedio fueron: hematocrito (Hto) 32,2 ± 1,4%; leucocitos (Leu) 5,2 ± 2,42 x10 µL ; 6 -1 -1 eritrocitos (Er) 1,3 ± 0,21 x10 µL ; hemoglobina (Hb) 10,4 ± 0,90 g dL ; volumen corpuscular medio (VCM) -1 249,9 ± 40,2 fL; concentración de hemoglobina corpuscular media (CHCM) 32,3 ± 2,5 g dL ; hemoglobina -1 -1 -1 corpuscular media (HCM) 80,6 ± 13,8 g dL ; albúmina 2,26 ± 0,82 g dL ; glucosa 54,83 ± 43,09 mg dL y -1 colesterol 104,63 ± 43,89 mg dL . Los valores hematológicos y bioquímicos se encontraron dentro de los rangos reportados para esta especie, mostrando condiciones fisiológicas normales al estar sometidos a condiciones intensivas de cultivo

Ontogeny of the digestive enzyme activity of the Amazonian pimelodid catfish Pseudoplatystoma punctifer (Castelnau, 1855)

The aim of the study was to evaluate the functional ontogeny of the digestive system of Pseudoplatystoma punctifer through the analysis of the activity of the main intestinal (alkaline phosphatase, aminopeptidase N, maltase and leucine-alanine peptidase), pancreatic (trypsin, chymotrypsin, total alkaline proteases, bile-salt activated lipase and amylase) and gastric (pepsin) enzymes. Larvae were raised in triplicate in a recirculation system from 4 to 27 days post fertilization (dpf) at an initial density of 90 larvae L−1, 27.8 ± 0.7 °C and 0 L: 24D photoperiod. Larvae were fed from 4 to 17 dpf with Artemia nauplii and weaned onto an experimentally formulated feed (crude protein content ~ 45%; crude fat content ~ 10%; crude carbohydrate ~ 8%) within 3 days, then continued with the same diet until the end of the trial. P. punctifer showed an exponential growth pattern with two different growth rates: a slower one from hatching to 12 dpf followed by a faster one from 12 to 27 dpf. The specific and total activities of the pancreatic and intestinal enzymes were detected from hatching. The digestive system was functional at 12 dpf, indicating the transition from the larval to the juvenile stage (alkaline to acid digestion). Therefore individuals could be weaned from that day onwards. The variations observed in the enzymatic activity from 17 dpf reflected the adaptation of the enzymatic machinery to the new diet supplied. P. punctifer larvae showed a fast digestive system development with an enzymatic profile typical of a tropical and carnivorous species.info:eu-repo/semantics/acceptedVersio

INFLUENCIA DE MICROALGAS EN EL CRECIMIENTO DEL ROTÍFERO DE AGUA DULCE Brachionus calyciflorus (PALLAS,1766), LORETO, PERÚ

The objective of the present study was to evaluate the influence of chlorophytes on the population growth of the rotifer Brachionus calyciflorus. The experimental culture was carried out in nine 4 L polyethylene containers with a useful volume of 800 mL of filtered water where ten Brachionus calyciflorus rotifers were planted per container and fed with microalgae at a concentration of 6 x 106 cel mL-1: Chlorella sp. (Ch), Scenedesmus sp. (Sc) and Chlorella sp. + Scenedesmus sp. (Ch + Sc), during 15 days of culture. Rotifers were counted daily and population growth parameters were evaluated. The mean values of: temperature were 27,7 ± 0,31 o C, dissolved oxygen 4,9 ± 0,05 mg L-1 and pH 6,6 ± 0,22. The highest population values were with the mixture of Chlorella sp + Scenedesmus sp (yield of 1250 ± 523 ind mL-1, growth rate of 1.0 ±, 0,1 day, doubling time of 0,7 ± 0,1 day and the maximum density of organisms of 8142,9 ind mL-1). The feeding of the rotifers in the present study shows better population growth parameters with the mixture of Chlorella sp. and Scenedesmus sp.El objetivo del presente estudio fue evaluar la influencia de las clorofitas en el crecimiento poblacional del rotífero Brachionus calyciflorus. El cultivo experimental se realizó en nueve recipientes de polietileno de 4 L con volumen útil de 800 mL de agua filtrada donde se sembraron diez rotíferos Brachionus calyciflorus por recipiente y fueron alimentados con microalgas a una concentración de 6 x 106 cel mL-1: Chlorella sp. (Ch), Scenedesmus sp. (Sc) y Chlorella sp. + Scenedesmus sp. (Ch + Sc), durante 15 días de cultivo. Diariamente se realizó el conteo de los rotíferos y se evaluaron los parámetros de crecimiento poblacional. Los valores medios de: temperatura fueron de 27,7 ± 0,31 oC, oxígeno disuelto de 4,9 ± 0,05 mg L-1 y pH de 6,6 ± 0,22. Los valores poblacionales más elevados en los rotíferos se obtuvieron alimentando con la mezcla de Chlorella sp. + Scenedesmus sp. (rendimiento de 1250 ± 523 ind mL-1, velocidad de crecimiento de 1,0 ± 0,1 día, tiempo de duplicación de 0,7 ± 0,1 día y la densidad máxima de organismos de 8142,9 ind. mL-1). La alimentación de los rotíferos en el presente estudio muestra mejores parámetros de crecimiento poblacional con la mezcla de Chlorella sp. y Scenedesmus sp

Epstein’s TARGET framework and motivational climate in sport: effects of a field-based, long-term intervention program

The aim of this study was to assess the long-term effects that the manipulation of the motivational climate can produce on social factors, psychological mediators, motivation and behavioural consequences. 283 student-athletes with ages ranging from 14 to 18 years (M = 13,54 ± 1,31) completed a questionnaire that included the BPNES, the PLOC, the subscales cooperative learning and improvement of the PMCSQ-2, as well as persistence, effort and boredom subscales. Epstein's TARGET strategies were applied to the experimental group during 12 weeks by specially trained coaches. The repeated measures MANOVA showed significant changes in all variables in the experimental group in post-test 1. Furthermore, these changes were maintained in most variables six months after the intervention (post-test 2). No significant changes were observed in the control group. Finally, the results are discussed and future lines of intervention are propose

Carbon export fluxes and export efficiency in the central Arctic during the record sea-ice minimum in 2012. A joint 234Th/238U and 210Po/210Pb study

The Arctic sea-ice extent amounted to its record minimum to date in September 2012. Sea-ice decline increases the absorption of solar energy in the Arctic Ocean, affecting primary production and plankton community. How this will modulate the sinking of POC from the ocean surface remains a key question. In this study we use the 234Th/238U and 210Po/210Pb radionuclide pairs to estimate the magnitude of the POC export fluxes in the upper ocean of the central Arctic in summer 2012, covering time scales from weeks to months, respectively. The 234Th/238U proxy reveals that POC fluxes at the base of the euphotic zone were very low (2 ± 2 mmol C m-2 d-1) in August and September. Relationships obtained between the 234Th export fluxes and the phytoplankton community suggest that prasinophytes would have contributed significantly to downward fluxes in late summer, likely via incorporation into sea-ice algal aggregates and zooplankton-derived material. In turn, the magnitude of the depletion of 210Po in the upper water column over the entire study area indicates that particle export fluxes were more relevant before July/August than later in the season. 210Po fluxes and 210Po-derived POC fluxes correlated positively with sea-ice concentration, showing that particle sinking was more important under heavy sea-ice conditions than under partially ice covered regions. Although the POC fluxes were low, a large fraction of primary production (>30%) was exported at the base of the euphotic zone in most of the study area during summer 2012, indicating a high export efficiency of the biological pump in the central Arctic

Floating Ice-Algal Aggregates below Melting Arctic Sea Ice

During two consecutive cruises to the Eastern Central Arctic in late summer 2012, we observed floating algal aggregates in the melt-water layer below and between melting ice floes of first-year pack ice. The macroscopic (1-15 cm in diameter) aggregates had a mucous consistency and were dominated by typical ice-associated pennate diatoms embedded within the mucous matrix. Aggregates maintained buoyancy and accumulated just above a strong pycnocline that separated meltwater and seawater layers. We were able, for the first time, to obtain quantitative abundance and biomass estimates of these aggregates. Although their biomass and production on a square metre basis was small compared to ice-algal blooms, the floating ice-algal aggregates supported high levels of biological activity on the scale of the individual aggregate. In addition they constituted a food source for the ice-associated fauna as revealed by pigments indicative of zooplankton grazing, high abundance of naked ciliates, and ice amphipods associated with them. During the Arctic melt season, these floating aggregates likely play an important ecological role in an otherwise impoverished near-surface sea ice environment. Our findings provide important observations and measurements of a unique aggregate-based habitat during the 2012 record sea ice minimum yea

Bone Marrow Mesenchymal Stem Cells Support Acute Myeloid Leukemia Bioenergetics and Enhance Antioxidant Defense and Escape from Chemotherapy.

Like normal hematopoietic stem cells, leukemic stem cells depend on their bone marrow (BM) microenvironment for survival, but the underlying mechanisms remain largely unknown. We have studied the contribution of nestin+ BM mesenchymal stem cells (BMSCs) to MLL-AF9-driven acute myeloid leukemia (AML) development and chemoresistance in vivo. Unlike bulk stroma, nestin+ BMSC numbers are not reduced in AML, but their function changes to support AML cells, at the expense of non-mutated hematopoietic stem cells (HSCs). Nestin+ cell depletion delays leukemogenesis in primary AML mice and selectively decreases AML, but not normal, cells in chimeric mice. Nestin+ BMSCs support survival and chemotherapy relapse of AML through increased oxidative phosphorylation, tricarboxylic acid (TCA) cycle activity, and glutathione (GSH)-mediated antioxidant defense. Therefore, AML cells co-opt energy sources and antioxidant defense mechanisms from BMSCs to survive chemotherapy.D.F. was supported by Associazione Italiana Ricerca sul Cancro (AIRCFellowship 20930 for Abroad) and scholarships from Società Italiana di Ematologia (SIE) and Associazione "Amici di Beat Leukemia Dr. Alessandro Cevenini ONLUS" and AIL Bologna ODV. A.S.-A. was supported by a European Hematology Association Research Fellowship and C.L.F-C. by a fellowship from Boehringer Foundation. This work was supported by core support grants from the Wellcome Trust (203151/Z/16/Z) and the MRC to the Cambridge Stem Cell Institute, and the Instituto de Salud Carlos III (ISCIII), Ministerio de Ciencia, Innovación y Universidades (MCNU) and Pro CNIC Foundation to CNIC, which is a Severo Ochoa Center of Excellence (SEV-2015-0505). This work was supported by MCNU (Plan Nacional grant SAF-2011-30308 to S.M.-F.; Ramón y Cajal Program grants RYC-2011-09726 to A.S.-A. and RYC-2009-04703 to S.M.-F.); Marie Curie Career Integration Program grants (FP7-PEOPLE-2011-RG-294262/294096) to A.S.-A. and S.M.-F.; Spanish Ministry of Science, Innovation and Universities (BIO2015-67580-P and PGC2018- 097019-B-I00), Carlos III Institute of Health-Fondo de Investigación Sanitaria grant PRB3(IPT17/0019 - ISCIII-SGEFI / ERDF, ProteoRed), Fundació MaratóTV3 (grant 122/C/2015) and “la Caixa” Banking Foundation (project code HR17-00247) to J.V.; the Medical Research Council grant MRC_MC_UU_12022/6 to C.F; an ERC award (COMAL: 647685) and a CRUK Programme Award to B.J.H; the Swiss National Science Foundation (SNF, 31003A_173224/1 & 31003A_173224/1) and the Gertrude von Meissner Foundation (Basel, Switzerland) to J.S.; ISCIII Spanish Cell Therapy Network TerCel, ConSEPOC-Comunidad de Madrid grant (S2010/BMD-2542), National Health Service Blood and Transplant (United Kingdom), European Union’s Horizon 2020 research (ERC- 2014-CoG-648765) and a Programme Foundation Award (C61367/A26670) from Cancer Research UK to S.M.-F., who was also supported in part by an International Early Career Scientist grant of the Howard Hughes Medical Institute