Toward the sustainable use of groundwater springs: A case study from Namibia

-The water supply in drylands mainly relies on groundwater, making it a crucial resource. Springs in southern Africa are often underutilized, and are neither protected nor monitored. Thus, the aim of this study was to evaluate their quality in a sample area in northwestern Namibia and to propose solutions for the sustainable use of springs. In total, 35 springs and hot springs were evaluated in the study area located in the drier part of Namibia (Pmean = 150–400 mm/year), an area highly impacted by ongoing climate change with longer and more frequent drought seasons. The springs there are mostly uncaptured and the discharge is in the form of surface runoff, which is mainly lost to the atmosphere by evaporation. Most of the studied springs were perennial, despite a severe drought period. Local communities rely on the springs mainly for livestock and human consumption, as well as for irrigation. However, 71% of the springs do not have any protective measures. The temperature, pH, conductivity and alkalinity were tested in situ. In total, 20 samples were collected and analyzed for major ions (boron, fluoride, silica and strontium) and total dissolved solids (TDS). The physical and inorganic results mostly indicated good and excellent quality water for human consumption, while the hot springs tended to have poor water quality in terms of Namibian standards, indicating that the water was not fit for human consumption

Towards a Rigorous Network of Protein-Protein Interactions of the Model Sulfate Reducer Desulfovibrio vulgaris Hildenborough

Protein–protein interactions offer an insight into cellular processes beyond what may be obtained by the quantitative functional genomics tools of proteomics and transcriptomics. The aforementioned tools have been extensively applied to study Escherichia coli and other aerobes and more recently to study the stress response behavior of Desulfovibrio vulgaris Hildenborough, a model obligate anaerobe and sulfate reducer and the subject of this study. Here we carried out affinity purification followed by mass spectrometry to reconstruct an interaction network among 12 chromosomally encoded bait and 90 prey proteins based on 134 bait-prey interactions identified to be of high confidence. Protein-protein interaction data are often plagued by the lack of adequate controls and replication analyses necessary to assess confidence in the results, including identification of potential false positives. We addressed these issues through the use of biological replication, exponentially modified protein abundance indices, results from an experimental negative control, and a statistical test to assign confidence to each putative interacting pair applicable to small interaction data studies. We discuss the biological significance of metabolic features of D. vulgaris revealed by these protein-protein interaction data and the observed protein modifications. These include the distinct role of the putative carbon monoxide-induced hydrogenase, unique electron transfer routes associated with different oxidoreductases, and the possible role of methylation in regulating sulfate reduction

Exploring the vertebrate fauna of the Bird’s Head Peninsula (Indonesia, West Papua) through DNA barcodes

Biodiversity knowledge is widely heterogeneous across the Earth's biomes. Some areas, due to their remoteness and difficult access, present large taxonomic knowledge gaps. Mostly located in the tropics, these areas have frequently experienced a fast development of anthropogenic activities during the last decades and are therefore of high conservation concerns. The biodiversity hotspots of Southeast Asia exemplify the stakes faced by tropical countries. While the hotspots of Sundaland (Java, Sumatra, Borneo) and Wallacea (Sulawesi, Moluccas) have long attracted the attention of biologists and conservationists alike, extensive parts of the Sahul area, in particular the island of New Guinea, have been much less explored biologically. Here, we describe the results of a DNA-based inventory of aquatic and terrestrial vertebratecommunities, which was the objective of a multidisciplinary expedition to the Bird's Head Peninsula (West Papua, Indonesia) conducted between 17 October and 20 November 2014. This expedition resulted in the assembly of 1005 vertebrate DNA barcodes. Based on the use of multiple species-delimitation methods (GMYC, PTP, RESL, ABGD), 264 molecular operational taxonomic units (MOTUs) were delineated, among which 75 were unidentified and an additional 48 were considered cryptic. This study suggests that the diversity of vertebrates of the Bird's Head is severely underestimated and considerations on the evolutionary origin and taxonomic knowledge of these biotas are discussed.Fieldwork and laboratory activities were supported by the Lengguru 2014 Project (www.lengguru.org), conducted by the French National Research Institute for Sustainable Development (IRD), the Indonesian Institute of Sciences (LIPI) with the Research Centre for Biology (RCB), and the Politeknik KP Sorong, with the help of the Institut Français in Indonesia (IFI) and the French embassy in Jakarta, with corporate sponsorship from COLAS SA Company (Environment Department), Total Foundation, ABS, Wasco, Veolia Eau, SDV-Bolloré,Peer reviewe

Are there "local hotspots?" When concepts of cognitive psychology do not fit with physiological results.

International audienceMather and colleagues' arguments require rethinking at the mechanistic level. The arguments on the physiological effects of norepinephrine at the cortical level are inconsistent with large parts of the literature. There is no evidence that norepinephrine induces local "hotspots": Norepinephrine mainly decreases evoked responses; facilitating effects are rare and not localized. More generally, the idea that perception benefits from "local hotspots" is hardly compatible with the fact that neural representations involve largely distributed activation of cortical and subcortical networks

Rôle des inhibitions corticales dans la dynamique temporelle des réponses neuronales dans le cortex auditif aux signaux de communication acoustiques

Depuis quelques années, l étude du code neuronal impliqué dans la perception des signaux de communication acoustique est devenue un domaine de recherche considérable. La littérature récente de ce domaine suggère que la discrimination entre ces signaux reposerait plutôt sur une organisation des décharges neuronales en motifs temporels que sur des variations globales de taux de décharge. Ma thèse a eu pour objectif de déterminer dans quelle mesure une régulation des inhibitions corticales peut (i) changer les motifs temporels déclenchés par des vocalisations conspécifiques et hétérospécifiques et (ii) modifier l information portée par ces motifs sur l identité des vocalisations. Nous avons enregistré l activité neuronale dans le cortex auditif de cobayes anesthésiés en 16 sites corticaux lors de la présentation d un jeu de vocalisations, et avons partiellement bloqué les inhibitions corticales par des applications de Gabazine (4minutes, 10 m). Dans ces conditions, les réponses évoquées sont plus fortes et les motifs temporels plus marqués. L information mutuelle quantifiée au niveau de chaque site cortical est augmentée mais l information populationnelle au niveau de l ensemble des 16 sites enregistrés n est pas modifiée, un effet qui peut s expliquer par le fait que la redondance entre les sites corticaux est augmentée. Nous avons ensuite évalué dans quelle mesure une modulation noradrénergique était susceptible de mimer les effets d un blocage partiel des inhibitions. Bien que les agonistes utilisés (a1, a2 et ) aient tous induit des modifications des réponses évoquées et de la reproductibilité des motifs temporels, aucun d entre eux n a induit de changements importants de l information portée par les réponses neuronales aux vocalisations. En revanche, les effets induits par la phenylephrine, un agoniste a1, sont vraisemblablement sous-tendus par une action sur les inhibitions intra-corticales, ce qui rend plausible l hypothèse d une modulation noradrénergique des inhibitions corticales. Il est donc envisageable que l action coordonnée de plusieurs systèmes neuromodulateurs puisse moduler les inhibitions corticales et ainsi changer la quantité d information portée par les neurones corticaux sur l identité des stimuli à discriminer.Over the last 10 years, the neural code involved in the perception of acoustic communication signals has become a large area of researches. The recent literature suggests that the discrimination between these signals relies more on the temporal organization of neuronal discharges rather than on global changes of firing rate. My PhD thesis aimed at determining to what extent the regulation of cortical inhibition may (i) change the temporal patterns triggered by conspecific and heterospecific vocalizations and (ii) modify the information carried by these patterns on the vocalization identity. Neuronal activity was recorded in the auditory cortex of anesthetized guinea pigs in 16 cortical sites during presentation of a set of vocalizations, and a partial blockage of intra-cortical inhibition was performed by Gabazine application (4 minutes, 10 m). Under these conditions, evoked responses were stronger and the temporal patterns were reinforced. Mutual information quantified at each cortical site was increased but the information computed at the populationnal level did not change, an effect that could be explained by the fact that the redundancy between cortical sites was increased. We then assessed to which extent the noradrenergic modulation can mimic the effects of a partial blockage of inhibitions. Although all the tested drugs modulated both the evoked responses and the spike-timing reliability, none of the noradrenergic agonists used here (a1, a2 and ) induced significant changes in the information carried by neuronal responses. However, the effects induced by phenylephrine, an a1 agonist, seemed to involve an action on the intra-cortical inhibition, which suggests that a noradrenergic modulation of cortical inhibition can operate in the auditory cortex. It is therefore possible to envision that the coordinated action of several neuromodulatory systems modulates cortical inhibition and thus changes the information carried by cortical neurons on the stimuli identity.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

How different are the local feld potentials and spiking activities ? Insights from multielectrodes arrays.

International audienceSimultaneous recording of multiple neurons, or neuron groups, offers new promise for investigating fundamental questions about the neural code. We used arrays of 16 electrodes in the tonotopic, primary, auditory cortex of guinea pigs and we extracted LFP- and spike-based spectro-temporal receptive fields (STRFs). We confirm here that LFP signals provide broadly tuned activity which lacks frequency resolution compared to multiunit signals and, therefore, lead to large redundancy in neural responses even between recording sites far apart. Thanks to the use of multi-electrode arrays which allows simultaneous recordings, we also focused on functional relationships between neuronal discharges (through cross-correlations) and between LFPs (through coherence). Since the LFP is composed of distinct brain rhythms, the LFP results were split into three frequency bands from the slowest to the fastest components of LFPs. For driven as well as spontaneous activity, we show that components >70 Hz in LFPs are much less coherent between recording sites than slower components. In general, coherence between LFPs from two recordings sites is positively correlated with the degree of frequency overlap between the two corresponding STRFs, similar to cross-correlation between multiunit activities. However, coherence is only weakly correlated with cross-correlation in all frequency ranges. Altogether, these results suggest that LFPs reflect global functional connectivity in the thalamocortical auditory system whereas spiking activities reflect more independent local processing

Social representation of social work in the Canadian healthcare setting: negotiating a professional identity

Our article concerns the social representation of social work held by professional social workers in a Canadian healthcare setting. While there have been extensive theoretical debates on the professional identity of social workers, little is known about the representation of social work held by practitioners themselves. To better understand the viewpoints of practitioners, we performed an integrated content analysis of 30 semi-directed interviews focussing on the question of professional identity with clinical social workers practicing in three Canadian cities. The analysis identified four elements organising the social representation of social work: “counselling for support”, “empowerment and respect”, “social justice” and “compassionate vocation”. Each element has implications for the daily practice of the profession, the cultivation of resilience and the core values of social work. This paper further discusses the respondents’ perception of outside views of the profession and explores the tensions between the values of social work and its implementation in an institutional setting. This research seeks to open new lines of inquiry about social work based on the experiences and points of view of front-line practitioners. In proposing our representational analysis of the professional identity of social workers, we hope to further the understanding of social work in general