Effects of elevated seawater pCO2 on gene expression patterns in the gills of the green crab, Carcinus maenas

Background: The green crab Carcinus maenas is known for its high acclimation potential to varying environmental abiotic conditions. A high ability for ion and acid-base regulation is mainly based on an efficient regulation apparatus located in gill epithelia. However, at present it is neither known which ion transport proteins play a key role in the acid-base compensation response nor how gill epithelia respond to elevated seawater pCO2 as predicted for the future. In order to promote our understanding of the responses of green crab acid-base regulatory epithelia to high pCO2, Baltic Sea green crabs were exposed to a pCO2 of 400 Pa. Gills were screened for differentially expressed gene transcripts using a 4,462-feature microarray and quantitative real-time PCR. Results: Crabs responded mainly through fine scale adjustment of gene expression to elevated pCO2. However, 2% of all investigated transcripts were significantly regulated 1.3 to 2.2-fold upon one-week exposure to CO2 stress. Most of the genes known to code for proteins involved in osmo- and acid-base regulation, as well as cellular stress response, were were not impacted by elevated pCO2. However, after one week of exposure, significant changes were detected in a calcium-activated chloride channel, a hyperpolarization activated nucleotide-gated potassium channel, a tetraspanin, and an integrin. Furthermore, a putative syntaxin-binding protein, a protein of the transmembrane 9 superfamily, and a Cl-/HCO3 - exchanger of the SLC 4 family were differentially regulated. These genes were also affected in a previously published hypoosmotic acclimation response study. Conclusions: The moderate, but specific response of C. maenas gill gene expression indicates that (1) seawater acidification does not act as a strong stressor on the cellular level in gill epithelia; (2) the response to hypercapnia is to some degree comparable to a hypoosmotic acclimation response; (3) the specialization of each of the posterior gill arches might go beyond what has been demonstrated up to date; and (4) a re-configuration of gill epithelia might occur in response to hypercapnia

Increased hippocampal CA1 density of serotonergic terminals in a triple transgenic mouse model of Alzheimer's disease: an ultrastructural study

Alzheimer's disease (AD) is a neurodegenerative pathology that deteriorates mnesic functions and associated brain regions including the hippocampus. Serotonin (5-HT) has an important role in cognition. We recently demonstrated an increase in 5-HT transporter (SERT) fibre density in the hippocampal CA1 in an AD triple transgenic mouse model (3xTg-AD). Here, we analyse the ultrastructural localisation, distribution and numerical density (Nv) of hippocampal SERT axons (SERT-Ax) and terminals (SERT-Te) and their relationship with SERT fibre sprouting and altered synaptic Nv in 3xTg-AD compared with non-transgenic control mice. 3xTg-AD animals showed a significant increase in SERT-Te Nv in CA1 at both, 3 (95%) and 18 months of age (144%), being restricted to the CA1 stratum moleculare (S. Mol; 227% at 3 and 180% at 18 months). 3xTg-AD animals also exhibit reduced Nv of perforated axospinous synapses (PS) in CA1 S. Mol (56% at 3 and 52% at 18 months). No changes were observed in the Nv of symmetric and asymmetrical synapses or SERT-Ax. Our results suggest that concomitant SERT-Te Nv increase and PS reduction in 3xTg-AD mice may act as a compensatory mechanism maintaining synaptic efficacy as a response to the AD cognitive impairment

Burnout in Organizational Life

Burnout is a psychological response to work stress that is characterized by emotional exhaustion, depersonalization, and reduced feelings of personal accomplishment. In this paper, we review the burnout literature from 1993 to present, identifying important trends that have characterized the literature. We focus our attention on theoretical models that explain the process of burnout, the measurement of burnout, means of reducing burnout, and directions for the future of burnout research.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Time domains of the hypoxic ventilatory response in ectothermic vertebrates

Over a decade has passed since Powell et al. (Respir Physiol 112:123–134, 1998) described and defined the time domains of the hypoxic ventilatory response (HVR) in adult mammals. These time domains, however, have yet to receive much attention in other vertebrate groups. The initial, acute HVR of fish, amphibians and reptiles serves to minimize the imbalance between oxygen supply and demand. If the hypoxia is sustained, a suite of secondary adjustments occur giving rise to a more long-term balance (acclimatization) that allows the behaviors of normal life. These secondary responses can change over time as a function of the nature of the stimulus (the pattern and intensity of the hypoxic exposure). To add to the complexity of this process, hypoxia can also lead to metabolic suppression (the hypoxic metabolic response) and the magnitude of this is also time dependent. Unlike the original review of Powell et al. (Respir Physiol 112:123–134, 1998) that only considered the HVR in adult animals, we also consider relevant developmental time points where information is available. Finally, in amphibians and reptiles with incompletely divided hearts the magnitude of the ventilatory response will be modulated by hypoxia-induced changes in intra-cardiac shunting that also improve the match between O2 supply and demand, and these too change in a time-dependent fashion. While the current literature on this topic is reviewed here, it is noted that this area has received little attention. We attempt to redefine time domains in a more ‘holistic’ fashion that better accommodates research on ectotherms. If we are to distinguish between the genetic, developmental and environmental influences underlying the various ventilatory responses to hypoxia, however, we must design future experiments with time domains in mind

Review of the projected impacts of climate change on coastal fishes in southern Africa

The coastal zone represents one of the most economically and ecologically important ecosystems on the planet, none more so than in southern Africa. This manuscript examines the potential impacts of climate change on the coastal fishes in southern Africa and provides some of the first information for the Southern Hemisphere, outside of Australasia. It begins by describing the coastal zone in terms of its physical characteristics, climate, fish biodiversity and fisheries. The region is divided into seven biogeographical zones based on previous descriptions and interpretations by the authors. A global review of the impacts of climate change on coastal zones is then applied to make qualitative predictions on the likely impacts of climate change on migratory, resident, estuarine-dependent and catadromous fishes in each of these biogeographical zones. In many respects the southern African region represents a microcosm of climate change variability and of coastal habitats. Based on the broad range of climate change impacts and life history styles of coastal fishes, the predicted impacts on fishes will be diverse. If anything, this review reveals our lack of fundamental knowledge in this field, in particular in southern Africa. Several research priorities, including the need for process-based fundamental research programs are highlighted

Evolution of gastric dysplasia in a non-cancerous population

Soixante quatorze malades non cancéreux porteurs de dysplasies gastriques ont été extraits d'un fichier de 2000 endoscopies digestives. Tous les examens endoscopiques et histologiques ont été pratiqués par les mêmes opérateurs respectifs. Cette enquête rétrospective permet d'établir une épidémiologie des dysplasies, puis, en ré-examinant les porteurs de lésion, d'apprécier les modalités évolutives de la muqueuse. La fréquence générale de l'affection est de 10,06 % dans la population étudiée et survient avec une nette prédominance masculine (3 hommes pour 1 femme). Elle s'associe dans 12,6 % des cas à une gastrite atrophique, dans 10,7 % à l'ulcère gastrique bénin, dans 7,1 % à des tumeurs bénignes et dans 1,6 % des cas à des cancers débutants. Les formes bénignes sont les plus fréquentes (84 %) et les plus graves les plus rares. Sur les 74 patients, 44 ont eu une évolution contrôlée: 13 sont décédés et 31 survivants ont pu être surveillés sur une période allant de 1 à 71 mois. On observe la guérison et/ou la régression des lésions dans la moitié des cas, un quart restant stable et le dernier quart seulement s'aggravant. Les dysplasies les plus bénignes sont les plus régressives et surviennent dans la population la plus jeune, alors que les formes sévères marquent leur tendance à l'aggravation dans la population nettement plus âgée. Enfin lorsqu'on examine la vitesse de transformation des dysplasies, on constate que les guérisons-régressions évoluent de façon sensiblement homogène, perdant en moyenne un degré de gravité tous les 20 mois. A partir de ces constatations, les auteurs tentent de dégager l'attitude pratique à adopter devant un malade porteur de dysplasie gastrique

Rapport V.7. Qualité des eaux et activités de loisirs

The first part of the article covers physico-chemical and biological water quality factors in their relationship to leisure activities ; the former factors include temperature, oxygen and nutritive salt contents, etc. and the latter bacteria, algae and plant life, invertebrata and fish. The second part deals with the effects of such leisure activités as bathing, fishing and motor-boating on water quality and the compatibility of such activities among themselves and with other uses made of water areas. The third part discusses the main equipment and maintenance requirements for leisure sites, which include such items as water supply protection and treatment, local drainage, keeping dangerous and prolific forms of life under control, and the provision of adequate depths of water.Le rapport examine d’abord sur le plan des activités de loisirs les divers paramètres physicochimiques (température, oxygène, sels nutritifs...) et biologiques (bactéries, algues et plantes, invertébrés, poissons) de la qualité des eaux. La deuxième partie traite de l’influence des diverses activités récréatives (baignade, pêche, motonautisme) sur la qualité des eaux et de la compatibilité de ces activités entre elles et avec les autres utilisations des plans d’eau. La troisième partie examine schématiquement les équipements et travaux d’entretien des bases de loisirs (protection et traitement des eaux d’alimentation, assainissement local, contrôle des espèces dangereuses ou envahissantes, aménagement des fonds).Leynaud G., Truchot Claude Maurice, Coin L., Labonde Josette-Lily. Rapport V.7. Qualité des eaux et activités de loisirs. In: Utilisation des ressources en eau d'un bassin dans le cadre de l'aménagement du territoire. Compte-rendu des onzièmes journées de l'hydraulique; Paris, 22-24 septembre 1970. Tome 2, 1971