115 research outputs found

    Unexpected appetitive events promote positive affective state in juvenile European sea bass

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    Some animal species exhibit considerable physiological and behavioural alterations in response to captivity. It has been hypothesized, but rarely tested, that such changes reflect a negative affective state that is associated to this specific context. In the last years, judgement bias measures have emerged as reliable indicators of animal affective state, under the assumption that individuals in a negative affective state are more likely to evaluate ambiguous stimuli as negative and display therefore pessimistic behaviours. Here, we have developed a judgement bias task for juvenile European sea bass (Dicentrarchus labrax) aiming to measure optimism/pessimism in this marine species, which have previously been reported to show important dysregulations in captive settings. Our results show that juvenile sea bass exhibit a considerable bias towards pessimistic behaviours in laboratory settings. Furthermore, juveniles that received an unexpected positive event during the judgement bias test displayed more optimistic responses toward ambiguous stimuli as compared to control fish, indicating a positive change in their affective state induced by the appetitive experience. These results reveal a direct interaction of the internal affective state with decision-making processing under ambiguity in juvenile European sea bass, highlighting therefore the potential of judgement bias tests as a tool for the advancement and improvement of our understanding of welfare in finfish aquaculture.Fundação para a Ciência e Tecnologia - FCT; Ministry of Science and Innovation (MCIN)info:eu-repo/semantics/publishedVersio

    Short telomeres drive pessimistic judgement bias in zebrafish.

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    The role of telomerase reverse transcriptase has been widely investigated in the contexts of ageing and age-related diseases. Interestingly, decreased telomerase activities (and accelerated telomere shortening) have also been reported in patients with emotion-related disorders, opening the possibility for subjective appraisal of stressful stimuli playing a key role in stress-driven telomere shortening. In fact, patients showing a pessimistic judgement bias have shorter telomeres. However, in humans the evidence for this is correlational and the causal directionality between pessimism and telomere shortening has not been established experimentally yet. We have developed and validated a judgement bias experimental paradigm to measure subjective evaluations of ambiguous stimuli in zebrafish. This behavioural assay allows classification of individuals in an optimistic-pessimistic dimension (i.e. from individuals that consistently evaluate ambiguous stimuli as negative to others that perceive them as positive). Using this behavioural paradigm we found that telomerase-deficient zebrafish (tert - / - ) were more pessimistic in response to ambiguous stimuli than wild-type zebrafish. The fact that individuals with constitutive shorter telomeres have pessimistic behaviours demonstrates for the first time in a vertebrate model a genetic basis of judgement bias.info:eu-repo/semantics/publishedVersio

    Resiliencia en profesionales de la intervención social

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    La resiliencia es un concepto con un enorme potencial para todas aquellas profesiones que reconocen en su objeto de intervención la prevención basada en las fortalezas y recursos propios de las personas y del entorno con el que se relacionan. En base a ello, existen numerosas investigaciones que analizan el papel de la intervención social y de sus profesionales en la construcción de la resiliencia de los individuos, grupos y comunidades hacia los que dirigen su actuación. Sin embargo, son menos frecuentes los trabajos de teorización e investigación centrados en el desarrollo y construcción de esta misma capacidad resiliente en los propios profesionales y en las implicaciones que de ello se deriva para su práctica profesional y para las organizaciones en las que se encuentran. Con el objetivo principal de analizar la presencia de la resiliencia en los profesionales de la intervención social frente a la de otros profesionales no relacionados con la ayuda social, se lleva a cabo una investigación de corte transversal en la que participan 366 sujetos, trabajadores sociales y otros profesionales – informáticos, ingenieros, trabajadores manuales y de servicios- todos ellos de la provincia de Málaga. Se analizan los diferentes los componentes de la resiliencia, siguiendo el modelo de Grotberg (1995). Los resultados apuntan hacia el colectivo de trabajadores sociales como más resilientes que el resto de profesionales.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Structural and functional control of surface-patch to hillslope runoff and sediment connectivity in Mediterranean dry reclaimed slope systems

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    Connectivity has emerged as a useful concept for exploring the movement of water and sediments between landscape locations and across spatial scales. In this study, we examine the structural and functional controls of surfacepatch to hillslope runoff and sediment connectivity in three Mediterranean dry reclaimed mining slope systems that have different long-term development levels of vegetation and rill networks. Structural connectivity was assessed using flow path analysis of coupled vegetation distribution and surface topography, providing field indicators of the extent to which surface patches that facilitate runoff and sediment production are physically linked to one another in the studied hillslopes. Functional connectivity was calculated using the ratio of patch-scale to hillslope-scale observations of runoff and sediment yield for 21 monitored hydrologically active rainfall events. The impact of the dynamic interactions between rainfall conditions and structural connectivity on functional connectivity were further analysed using general linear models with a backward model structure selection approach. Functional runoff connectivity during precipitation events was found to be dynamically controlled by antecedent precipitation conditions and rainfall intensity and strongly modulated by the structural connectivity of the slopes. On slopes without rills, both runoff and sediments for all events were largely redistributed within the analysed hillslopes, resulting in low functional connectivity. Sediment connectivity increased with rainfall intensity, particularly in the presence of rill networks where active incision under high-intensity storm conditions led to large non-linear increases in sediment yield from the surface-patch to the hillslope scales. Overall, our results demonstrate the usefulness of applying structuraland functional-connectivity metrics for practical applications and for assessing the complex links and controlling factors that regulate the transference of both surface water and sediments across different landscape scales

    Gonadotropin actions in European sea bass: endocrine roles and biotechnological applications

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    Comunicación presentada en el 10th International Symposium on Reproductive Physiology of Fish, celebrado en Olhao, Portugal, del 25 al 30 de mayo de 2014The follicle stimulating hormone (Fsh) and the luteinizing hormone (Lh) are central endocrine regulators of gonad function in vertebrates. These gonadotropins act by binding and activating their specific receptors that are located in certain cell types of the gonads. In fish, the differential roles of these hormones are being progressively elucidated with the development of different tools for their study. In the case of European sea bass Dicentrarchus labrax, the isolation of the genes coding for the gonadotropin subunits and receptors allowed in first instance for expression studies. Later, to overcome the limitation of native hormones, recombinant dimeric gonadotropins have been generated, which show different functional characteristics depending on the cell system and DNA construct. In addition, single gonadotropin beta-subunits have been produced and used as antigens for antibody production. This last approach has allowed the development of detection methods for native gonadotropins being the European sea bass one of the few species where both gonadotropins can be detected in their native form. The generation of antibodies has also allowed for their cellular localization and co-localization with other factors, helping to a better understanding of their function. By administration of the recombinant gonadotropins to gonad tissues cultured in vitro we have studied their effects on steroidogenesis, the activated intracellular pathways and their target genes. Their administration in vivo has also been tested both for basic studies and as a biotechnological approach. In this frame, it is known from different studies in mammals that exogenous administration of native hormones in cases of deficiency, including assisted reproduction, can be unsatisfactory due to their rapid clearance from circulation or limited availability. Other than the production of recombinant hormones gene-based therapies by using somatic gene transfer are offered as an alternative. Such an approach has been tested in sea bass for gonadotropin delivery in vivo. The hormones produced by the injected genes were functional and have allowed for different studies on gonadotropin action in spermatogenesis. All together, the use of gene therapy for hormone replacement in fish is a real alternative to the production of recombinant gonadotropins for in vivo use, due to the low cost of production and the high persistence of the injected DNA, and has a broad range of potential applications such as its use in out-of-season breeding programs or reproductive dysfunctions in fish species.Supported by MINECO (AGL2011-28890) and GV (ACOMP/2013/085).Peer Reviewe

    Molecular evolution of aphids and their primary (buchnera sp.) and secondary endosymbionts: implications for the role of symbiosis in insect evolution

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    Aphids maintain an obligate, endosymbiotic association with Buchnera sp., a bacterium closely related to Escherichia coli. Bacteria are housed in specialized cells of organ-like structures called bacteriomes in the hemocoel of the aphid and are maternally transmitted. Phylogenetic studies have shown that the association had a single origin, dated about 200-250 million years ago, and that host and endosymbiont lineages have evolved in parallel since then. However, the pattern of deepest branching within the aphid family remains unsolved, which thereby hampers an appraisal of, for example, the role played by horizontal gene transfer in the early evolution of Buchnera. The main role of Buchnera in this association is the biosynthesis and provisioning of essential amino acids to its aphid host. Physiological and metabolic studies have recently substantiated such nutritional role. In addition, genetic studies of Buchnera from several aphids have shown additional modifications, such as strong genome reduction, high A+T content compared to free-living bacteria, differential evolutionary rates, a relative increase in the number of non-synonymous substitutions, and gene amplification mediated by plasmids. Symbiosis is an active process in insect evolution as revealed by the intermediate values of the previous characteristics showed by secondary symbionts compared to free-living bacteria and Buchnera.The authors thank the Servicio Central de Soporte a la Investigación Científica (Universitat de València) for bioinformatics and sequencing facilities. The work has been supported by grants GV-3216/95 from Generalitat Valenciana (Spain), BFM2000-1383 from MEC (Spain) and FEDER 2FD1997-1006 (Spain).Peer reviewe

    Conditioned stochastic particle systems and integrable quantum spin systems

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    We consider from a microscopic perspective large deviation properties of several stochastic interacting particle systems, using their mapping to integrable quantum spin systems. A brief review of recent work is given and several new results are presented: (i) For the general disordered symmectric exclusion process (SEP) on some finite lattice conditioned on no jumps into some absorbing sublattice and with initial Bernoulli product measure with density ρ\rho we prove that the probability Sρ(t)S_\rho(t) of no absorption event up to microscopic time tt can be expressed in terms of the generating function for the particle number of a SEP with particle injection and empty initial lattice. Specifically, for the symmetric simple exclusion process on Z\mathbb Z conditioned on no jumps into the origin we obtain the explicit first and second order expansion in ρ\rho of Sρ(t)S_\rho(t) and also to first order in ρ\rho the optimal microscopic density profile under this conditioning. For the disordered ASEP on the finite torus conditioned on a very large current we show that the effective dynamics that optimally realizes this rare event does not depend on the disorder, except for the time scale. For annihilating and coalescing random walkers we obtain the generating function of the number of annihilated particles up to time tt, which turns out to exhibit some universal features.Comment: 25 page

    Weeds, aphids, and specialist parasitoids and predators benefeit differently from organic and conventional cropping of winter cereals

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    The aphid–natural enemy interaction in winter wheat fields constitutes a complex system that has been frequently studied because of its implication for biological control. However, not all of the aphids living in cereal fields are crop pests, as there are also aphids living on weeds that may serve as alternative hosts or prey for aphid parasitoids or predators. In this context, a concomitant survey of the plant and insect communities was conducted to understand how different plant communities affect the abundance and richness of aphids and the interactions with their natural enemies. The plant community was split into functional groups (grasses, legumes and forbs), and the aphid community was divided into feeding groups according to their host preferences (specialists in grasses or forbs). The grass aphids, which dominated the total aphid catches, responded positively to grass cover, which was particularly enhanced in the conventional fields. Conversely, the forb aphids, which mainly conditioned the total species richness of the aphids, were closely correlated with the local abundance of legumes. The system of cereal aphid-parasitoids was enhanced in the conventional fields, where the abundance of grasses was higher, whereas the legumes of the organic fields indirectly played a key role in enhancing the richness of the parasitoids and the abundance of predators. Our findings indicate that a bottom-up effect exists throughout the plant community, aphids, and aphidophagous insects and that plant community characteristics shouldPeer ReviewedPostprint (published version

    Cost effectiveness of total knee arthroplasty from a health care providers' perspective before and after introduction of an interdisciplinary clinical pathway - is investment always improvement?

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    <p>Abstract</p> <p>Background</p> <p>Total knee arthroplasty (TKA) is an effective, but also cost-intensive health care intervention for end stage osteoarthritis. This investigation was designed to evaluate the cost-effectiveness of TKA before versus after introduction of an interdisciplinary clinical pathway from a University Orthopedic Surgery Department's cost perspective as an interdisciplinary full service health care provider.</p> <p>Methods</p> <p>A prospective trial recruited two sequential cohorts of 132 and 128 consecutive patients, who were interviewed by means of the WOMAC questionnaire. Direct process costs from the health care providers' perspective were estimated according to the German DRG calculation framework. The health economic evaluation was based on margiual cost-effectveness ratios (MCERs); an individual marginal cost effectiveness relation ≤ 100 € per % WOMAC index increase was considered as primary endpoint of the confirmatory cohort comparison. The interdisciplinary clinical pathway under consideration primarily consisted of a voluntary preoperative personal briefing of patients concerning postoperatively expectable progess in health status and optimum use of walking aids after surgery. All patients were supplied with written information on these topics, attendance of the personal briefing also included preoperative training for postoperative mobilisation by the Department's physiotherapeutic staff.</p> <p>Results</p> <p>An individual marginal cost effectiveness relation ≤ 100 €/% WOMAC index increase was found in 38% of the patients in the pre pathway implementation cohort versus in 30% of the post pathway implementation cohort (Fisher p = 0.278). Both cohorts showed substantial improvement in WOMAC scores (39 versus 35% in median), whereas the cohort did not differ significantly in the median WOMAC score before surgery (41% for the pre pathway cohort versus 44% for the post pathway cohort). Despite a locally significant decrease in costs (4303 versus 4194 € in median), the individual cost/benefit relation became worse after introduction of the pathway: for the first cohort the MCER was estimated 108 € per gained % WOMAC index increase (86 - 150 €/%) versus 118 €/% WOMAC gain (93 - 173 €/%) in the second cohort after pathway implementation. In summary, the proposed critical pathway for TKA could be shown to be significantly cost efficient, but not cost effective concerning functional outcome, when the above individual marginal cost effectiveness criterion was concentrated on.</p> <p>Conclusions</p> <p>The introduction of an interdisciplinary clinical pathway does not necessarily improve patient related outcomes. On the contrary, cost effectiveness from the health care providers' perspective may even turn out remarkably reduced in the setting considered here (functional outcome assessment after treatment by a full service health care provider).</p
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