Influencia de la temperatura y la salinidad sobre el crecimiento y consumo de oxígeno de la dorada ("Sparus aurata" L.)

Actualmente, la dorada es el principal producto de la acuicultura mediterránea. Para rentabilizar su cultivo, es necesario optimizar los procesos biológicos productivos que permitan una buena gestión de la explotación. La presente tesis es una aproximación a las condiciones más idóneas de temperatura, salinidad y concentración de oxigeno disuelto (OD) en el agua, para el cultivo en tierra de la dorada. Para ello, se evaluó la influencia de estas variables sobre el crecimiento de los animales y su metabolismo asociado, factores que influyen directamente en el rendimiento del cultivo. Las contribuciones más relevantes hacen referencia principalmente, al beneficio de reducir la salinidad durante el periodo de pre-engorde de los alevines y al establecimiento de los requerimientos metabólicos y los niveles críticos de OD soportables por la especie.La salinidad óptima para el cultivo de alevines de dorada durante el primer año de vida (hasta 85-90g), está comprendida entre 22 y 28 de salinidad. Alcanzado este peso se modifican estas preferencias hasta los 150g, a partir de los cuales la salinidad marina es la más idónea para obtener el mejor rendimiento en crecimiento y eficacia alimentaria. Este efecto concuerda con el ciclo biológico natural de la dorada. La salinidad óptima es edad-dependiente que soporta la teoría de que existe un modelo ontogénico de tolerancia a la salinidad.Como especie osmoreguladora que es, la dorada puede vivir dentro de un amplio rango salino, pero con un coste metabólico elevado para mantener invariable su osmolaridad plasmática. El ahorro energético de casi el 2% por cada 1 de salinidad disminuido, puede invertirse en otras funciones como el crecimiento. En consecuencia,la tasa metabólica específica de masa (mgO2/Kg/h) es función decreciente del peso y creciente de la temperatura y la salinidad. El metabolismo de rutina de una dorada estándar de 100g de peso, a 20ºC de temperatura y 36 de salinidad, requiere aproximadamente 190 mgO2/Kg/h, de los cuales el 70% corresponde al metabolismo de reposo. El efecto global de la alimentación sobre la tasa metabólica, implica más de la mitad del consumo de oxigeno (CO) total y se prolonga hasta 41 horas después del suministro de alimento.La dorada aumenta su ventilación respiratoria al descender el contenido de oxigeno del agua (hipoxia) para mantener el CO constante. El punto crítico en el cual se inicia este aumento, considerado de estrés hipóxico, se encuentra en 5.5 mgO2/l a 20-22ºC. La concentración crítica a partir de la cual la dorada empieza a perder su capacidad oxireguladora y el CO desciende gradualmente, se encuentra entre 2.0 y 4.5 mgO2/l según salinidad y peso. La concentración crítica a partir de la cual el CO es directamente proporcional al OD, se encuentra entre 1.5 y 2.8 mgO2/l según salinidad y peso. Los síntomas de anoxia se manifiestan a partir de 1.5 mgO2/l y la pérdida de equilibrio hacia 1 mgO2/l, por lo que consideramos estas concentraciones como subletal y letal, respectivamente, para la dorada. El punto crítico de oxigenación del agua es función directa del nivel metabólico del pez en el momento de iniciarse es episodio de hipoxia. Por consiguiente, la dorada será más sensible al descenso de la concentración de OD con cualquier factor que incremente la demanda de oxigeno del pez (peso, temperatura, salinidad, actividad, etc.

Optical and magneto-optical properties of highly distorted Fe 100 thin films

PACS:78.20.Ls,71.15.-m,75.50.BbTiN-capped epitaxial bcc Fe films exhibit strong changes in the out-of-plane interplanar distance depending on the growth conditions. At room temperature, the increase of the volume per Fe atom appears to be as large as 5%. The observed distortions deviate substantially from elastic behavior. We explain this effect as due to the presence of nitrogen incorporated into the Fe film during the capping layer deposition. In order to elucidate the effect that these distortions might have on the optical and magneto-optical properties, we study the diagonal and off-diagonal elements of the conductivity tensor for both distorted and undistorted structures. This is done by means of spectral ellipsometry and the Kerr effect in polar and transverse configurations in the energy range from 1.5 to 4.5 eV. Theoretical calculations using ab initio techniques for the observed structures are performed and compared with experimental data. Different possible mechanisms for the experimentally observed effects such as distortion, grain size, and orbital hybridization are studied and discussed.The work was carried out with financial support from the Spanish Commission of Science and Technology (Grant Nos. MAT98-0974-C03-01 and MAT99- 0724-C03-03) and Comunidad Auto´noma de Madrid (Grant No. 07N/0056/1999).Peer reviewe

‘Honeycrisp’ Bitter Pit Response to Rootstock and Region under Eastern New York Climatic Conditions

There are still unknown factors at play in the causation of bitter pit in ‘Honeycrisp’ as well as in other apple varieties. To investigate some of these factors, we conducted a survey of 34 ‘Honeycrisp’ orchard blocks distributed across two disparate production regions in eastern New York State, representing a variety of rootstocks, over three growing seasons. Weather, soil, horticultural traits, fruit quality traits, pick timing, leaf and peel minerals were evaluated for their impact on bitter pit (BP) incidence; factors were further evaluated for their interaction with region and rootstock. ‘Honeycrisp’ trees on B.9 rootstock were smaller but with comparable terminal shoot growth when compared to those on M.26 and M.9 rootstocks. B.9 fruits, which had similar fruit size to M.26 and M.9 and had good fruit quality at harvest and after storage, were much less likely to express bitter pit symptoms compared to M.9 and M.26 rootstocks. Not all traits evaluated individually correlated significatively with bitter pit incidence after a period in storage. Depending on rootstock and region, the correlation could be significant in one situation, with no correlation at all in another. In this study, peel Mg/Ca ratio and peel Ca correlated with BP for all three rootstocks, with the strongest correlations associated with the M.9 clones. These same traits correlated with BP for both regions. Pick timing had a significant influence on BP incidence following storage, with later picks offering better bitter pit storage performance. While excessively large fruits, those in the 48 and 56 count size categories, were found to be highly susceptible to BP regardless of rootstock, B.9 BP fruit susceptibility for smaller sizes was found to be size neutral. A PLSR prediction model for each rootstock and each region showed that different variables correlated to BP depending on the situation. Thus, the results could suggest that in addition to the variables considered in this study, there are other less studied factors that can influence the expression of BP symptoms. We strongly suggest that rootstock BP performance be considered a critical parameter when planning a commercial ‘Honeycrisp’ orchard and be evaluated in rootstock breeding and development programs prior to wide commercial release.info:eu-repo/semantics/publishedVersio

Hepatic Oxi-Inflammation and Neophobia as Potential Liver-Brain Axis Targets for Alzheimer's Disease and Aging, with Strong Sensitivity to Sex, Isolation, and Obesity

Altres ajuts: Memorial Mercedes Llort Sender, 2021/80/09241941.8; Universitat Autònoma de Barcelona, UAB-GE-260408Research on Alzheimer's disease (AD) has classically focused on alterations that occur in the brain and their intra- and extracellular neuropathological hallmarks. However, the oxiinflammation hypothesis of aging may also play a role in neuroimmunoendocrine dysregulation and the disease's pathophysiology, where the liver emerges as a target organ due to its implication in regulating metabolism and supporting the immune system. In the present work, we demonstrate organ (hepatomegaly), tissue (histopathological amyloidosis), and cellular oxidative stress (decreased glutathione peroxidase and increased glutathione reductase enzymatic activities) and inflammation (increased IL-6 and TNFα) as hallmarks of hepatic dysfunction in 16-month-old male and female 3xTgAD mice at advanced stages of the disease, and as compared to age- and sex-matched non-transgenic (NTg) counterparts. Moreover, liver-brain axis alterations were found through behavioral (increased neophobia) and HPA axis correlations that were enhanced under forced isolation. In all cases, sex (male) and isolation (naturalistic and forced) were determinants of worse hepatomegaly, oxidative stress, and inflammation progression. In addition, obesity in old male NTg mice was translated into a worse steatosis grade. Further research is underway determine whether these alterations could correlate with a worse disease prognosis and to establish potential integrative system targets for AD research

Regorafenib Alteration of the BCL-xL/MCL-1 Ratio Provides a Therapeutic Opportunity for BH3-Mimetics in Hepatocellular Carcinoma Models

Background: The multikinase inhibitor regorafenib, approved as second-line treatment for hepatocellular carcinoma (HCC) after sorafenib failure, may induce mitochondrial damage. BH3-mimetics, inhibitors of specific BCL-2 proteins, are valuable drugs in cancer therapy to amplify mitochondrial-dependent cell death. Methods: In in vitro and in vivo HCC models, we tested regorafenib's effect on the BCL-2 network and the efficacy of BH3-mimetics on HCC treatment. Results: In hepatoma cell lines and Hep3B liver spheroids, regorafenib cytotoxicity was potentiated by BCL-xL siRNA transfection or pharmacological inhibition (A-1331852), while BCL-2 antagonism had no effect. Mitochondrial outer membrane permeabilization, cytochrome c release, and caspase-3 activation mediated A-1331852/regorafenib-induced cell death. In a patient-derived xenograft (PDX) HCC model, BCL-xL inhibition stimulated regorafenib activity, drastically decreasing tumor growth. Moreover, regorafenib-resistant HepG2 cells displayed increased BCL-xL and reduced MCL-1 expression, while A-1331852 reinstated regorafenib efficacy in vitro and in a xenograft mouse model. Interestingly, BCL-xL levels, associated with poor prognosis in liver and colorectal cancer, and the BCL-xL/MCL-1 ratio were detected as being increased in HCC patients. Conclusion: Regorafenib primes tumor cells to BH3-mimetic-induced cell death, allowing BCL-xL inhibition with A-1331852 or other strategies based on BCL-xL degradation to enhance regorafenib efficacy, offering a novel approach for HCC treatment, particularly for tumors with an elevated BCL-xL/MCL-1 ratio

Information impact on consumers' perceptions towards aquaculture : Dismantling the myth about feeds for farmed fish

Altres ajuts: Acord transformatiu CRUE-CSICAquaculture products are commonplace in markets around the world. However, despite efforts to minimize the negative perceptions towards aquaculture, several misbeliefs or myths still persist, and thus globally consumers tend to value wild fish more highly than farmed fish. The lack of information has been shown to be one of the most important causes of this preference, driving buying decisions to be more emotional than rational. The aim of this study was to determine whether scientific-supported information contrasting one myth could contribute to a better perception of farmed products. To that end, consensus on a series of aquaculture-related issues among different scientists, external experts, and aquaculture societies was used to build up the scientific information. This information was provided to 300 Spanish consumers using two different communication tools (150 consumers each tool): an interactive web documentary and a written and printed document, to detect possible differences in the change of consumers' perception. Consumers were asked for their degree of agreement on a set of 14 statements before and after providing the scientific information. A variable collecting the assessment of each of the statements was calculated as the Overall-perception. Possible significant differences between the scores before and after providing the information and for the 'overall perception' were analysed separately for each communication tool as well as for the combined sample. Possible relationship between the consumers' perception with the sociodemographic factors, the consumers' knowledge and the fish consumption habits were also assessed. Results show that consumer's perception of aquaculture before the query were moderate (5.6 average in a 0 to 10 scale) but that it increased slightly but significantly and regardless of the communication tool used. Among sociodemographic factors, age and gender were the ones that most influenced consumer's perceptions, being older people those who exhibited a generally more positive opinion towards aquaculture. The effects of consumption habits and knowledge about aquaculture were also the two most explicative factors for change in perception. Importantly, the opinion of consumers with less knowledge about seafood products in general and production methods or consuming only wild fish products, improved after being exposed to the information. These results demonstrate the utility of science- and fact-based communication campaigns to improve the societal perception of aquaculture practices and products, regardless of the tool used to transmit this information

Antiapoptotic BCL-2 proteins determine Sorafenib/regorafenib resistance and BH3-mimetic efficacy in hepatocellular carcinoma

Sorafenib, systemic treatment for advanced hepatocellular carcinoma (HCC), and regorafenib, novel second line treatment after sorafenib failure, have efficacy limited by evasive mechanisms of acquired-drug resistance. BCL-2 proteins participate in the response to tyrosine kinase inhibitors; however, their role in HCC therapy with sorafenib/regorafenib remains uncertain. BH3-mimetic ABT-263 (navitoclax) enhanced sorafenib activity, inducing cell death via a mitochondrial caspase-dependent mechanism, after BCL-xL/BCL-2 inhibition. Sorafenib-resistant hepatoma cells (HepG2R and Hep3BR) exhibited altered mRNA expression of BCL-2 and other anti-apoptotic family members, such as MCL-1, priming drug-resistant cancer cells to death by BH3-mimetics. ABT-263 restored sorafenib efficacy in sorafenib-resistant cell lines and HCC mouse models. Moreover, in mice xenografts from patient-derived BCLC9 cells, better tumor response to sorafenib was associated to higher changes in the BCL-2 mRNA pattern. HCC non-treated patients displayed altered BCL-2, MCL-1 and BCL-xL mRNA levels respect to adjacent non-tumoral biopsies and an increased BCL-2/MCL-1 ratio, predictive of navitoclax efficacy. Moreover, regorafenib administration also modified the BCL-2/MCL-1 ratio and navitoclax sensitized hepatoma cells to regorafenib by a mitochondrial caspase-dependent mechanism. In conclusion, sorafenib/regorafenib response is determined by BCL-2 proteins, while increased BCL-2/MCL-1 ratio in HCC sensitizes drug resistant-tumors against ABT-263 co-administration. Thus, changes in the BCL-2 profile, altered in HCC patients, could help to follow-up sorafenib efficacy, allowing patient selection for combined therapy with BH3-mimetics or early switch them to second line therapy

Evolution of Serum Acute-Phase Glycoproteins Assessed by 1H-NMR in HIV Elite Controllers

Elite controllers (ECs) are an exceptional group of people living with HIV (PLWH) who maintain undetectable viral loads (VLs) despite not being on antiretroviral therapy (ART). However, this phenotype is heterogeneous, with some of these subjects losing virological control over time. In this longitudinal retrospective study, serum acute-phase glycoprotein profile assessed by proton nuclear magnetic resonance (1H-NMR) was determined in 11 transient controllers (TCs) who spontaneously lost virological control and 11 persistent controllers (PCs) who persistently maintained virological control over time. Both PCs and TCs showed similar acute-phase glycoprotein profiles, even when TCs lost the virological control (GlycB, p = 0.824 and GlycA, p = 0.710), and the serum acute-phase glycoprotein signature in PCs did not differ from that in HIV-negative subjects (GlycB, p = 0.151 and GlycA, p = 0.243). Differences in serum glycoproteins A and B were significant only in ECs compared to HIV-typical progressors (TPs) with < 100 CD4+ T-cells (p < 0.001). 1H-NMR acute-phase glycoprotein profile does not distinguish TCs form PCs before the loss of viral control. ECs maintain a low-grade inflammatory state compared to TPs. PCs revealed a closer serum signature to HIV-negative subjects, reaffirming this phenotype as a closer model of functional control of HIV.This research was funded by the Fondo de Investigacion Sanitaria [PI16/00503, PI19/01337 and PI20/00326]-ISCIII-FEDER (co-funded by the European Regional Development Fund/European Social Fund; “A way to make Europe”/“Investing in your future”); Programa de Suport als Grups de Recerca AGAUR (2017SGR948); the SPANISH AIDS Research Network [RD12/0017/0005, RD12/0025/0001, RD16/0025/0006]-ISCIII-FEDER (Spain) and Centro de Investigación Biomédica en Red de Enfermedades Infecciosas-ISCIII [CB21/13/00015, CB21/13/00020, CB13/21/00086], Madrid, Spain. JM is supported by the Universitat Rovira i Virgili under grant agreement “2019PMF-PIPF-18,” through the call “Martí Franquès Research Fellowship Programme”. FV is supported by grants from the Programa de Intensificación de Investigadores (INT20/00031)-ISCIII. AR is supported by a grant from IISPV through the project “2019/IISPV/05” (Boosting Young Talent), by GeSIDA through the “III Premio para Jóvenes Investigadores 2019” and by the Instituto de Salud Carlos III (ISCIII) under grant agreement “CP19/00146” through the Miguel Servet Program.S