Bivalve δ15N isoscapes provide a baseline for urban nitrogen footprint at the edge of a World Heritage coral reef.

Eutrophication is a major threat to world's coral reefs. Here, we mapped the distribution of the anthropogenic nitrogen footprint around Nouméa, a coastal city surrounded by 15,743 km2 of UNESCO listed reefs. We measured the δ15N signature of 348 long-lived benthic bivalves from 12 species at 27 sites and interpolated these to generate a δ15N isoscape. We evaluated the influence of water residence times on nitrogen enrichment and predicted an eutrophication risk at the UNESCO core area. Nitrogen isoscapes revealed a strong spatial gradient (4.3 to 11.7‰) from the outer lagoon to three highly exposed bays of Nouméa. Several protected reefs would benefit from an improved management of wastewater outputs, while one bay in the UNESCO core area may suffer a high eutrophication risk in the future. Our study reinforces the usefulness of using benthic animals to characterize the anthropogenic N-footprint and provide a necessary baseline for both ecologists and policy makers.

Modelling the impact of a La Niña event on a South West Pacific Lagoon.

In view of increasing environmental awareness and biodiversity conservation, understanding the main forcing mechanism driving biogeochemical cycles in coral reefs and lagoon coastal areas is a priority. La Niña events cause unbalanced situations in the Equatorial Pacific and result in enhanced precipitation in South West Pacific coastal areas. We investigated the impact of heavy rainfalls during the 2008 La Niña event on the New Caledonia lagoon using a 3D coupled on-line hydrodynamic-biogeochemical model. Simulations and data showed that the whole lagoon was impacted by river inputs and stronger hydrodynamics, enhancing chlorophyll-a concentration by a factor between 1.7 and 1.9. The coupled model provided new insights into plume transport, highlighting that eastern plumes can be advected northwards or can reach the South West Lagoon, depending on the balance between regional, tide-induced, and wind-induced surface currents. It also provided a synoptic view of lagoon biogeochemical-hydrodynamic response, when remote sensing data are not available due to cloud coverage.

Biogeochemical typology and temporal variability of lagoon waters in a coral reef ecosystem subject to terrigeneous and anthropogenic inputs (New Caledonia).

Considering the growing concern about the impact of anthropogenic inputs on coral reefs and coral reef lagoons, surprisingly little attention has been given to the relationship between those inputs and the trophic status of lagoon waters. The present paper describes the distribution of biogeochemical parameters in the coral reef lagoon of New Caledonia where environmental conditions allegedly range from pristine oligotrophic to anthropogenically influenced. The study objectives were to: (i) identify terrigeneous and anthropogenic inputs and propose a typology of lagoon waters, (ii) determine temporal variability of water biogeochemical parameters at time-scales ranging from hours to seasons. Combined ACP-cluster analyses revealed that over the 2000 km(2) lagoon area around the city of Nouméa, "natural" terrigeneous versus oceanic influences affecting all stations only accounted for less than 20% of the spatial variability whereas 60% of that spatial variability could be attributed to significant eutrophication of a limited number of inshore stations. ACP analysis allowed to unambiguously discriminating between the natural trophic enrichment along the offshore-inshore gradient and anthropogenically induced eutrophication. High temporal variability in dissolved inorganic nutrients concentrations strongly hindered their use as indicators of environmental status. Due to longer turn over time, particulate organic material and more specifically chlorophyll a appeared as more reliable nonconservative tracer of trophic status. Results further provided evidence that ENSO occurrences might temporarily lower the trophic status of the New Caledonia lagoon. It is concluded that, due to such high frequency temporal variability, the use of biogeochemical parameters in environmental surveys require adapted sampling strategies, data management and environmental alert methods.

Circulation and suspended sediment transport in a coral reef lagoon: the south-west lagoon of New Caledonia.

The south-west lagoon of New Caledonia is a wide semi-open coral reef lagoon bounded by an intertidal barrier reef and bisected by numerous deep inlets. This paper synthesizes findings from the 2000-2008 French National Program EC2CO-PNEC relative to the circulation and the transport of suspended particles in this lagoon. Numerical model development (hydrodynamic, fine suspended sediment transport, wind-wave, small-scale atmospheric circulation) allowed the determination of circulation patterns in the lagoon and the charting of residence time, the later of which has been recently used in a series of ecological studies. Topical studies based on field measurements permitted the parameterisation of wave set-up induced by the swell breaking on the reef barrier and the validation of a wind-wave model in a fetch-limited environment. The analysis of spatial and temporal variability of suspended matter concentration over short and long time-scales, the measurement of grain size distribution and the density of suspended matter (1.27 kg l(-1)), and the estimation of erodibility of heterogeneous (sand/mud, terrigenous/biogenic) soft bottoms was also conducted. Aggregates were shown to be more abundant near or around reefs and a possible biological influence on this aggregation is discussed. Optical measurements enabled the quantification of suspended matter either in situ (monochromatic measurements) or remotely (surface spectral measurements and satellite observations) and provided indirect calibration and validation of a suspended sediment transport model. The processes that warrant further investigation in order to improve our knowledge of circulation and suspended sediment transport in the New Caledonia lagoon as well as in other coral reef areas are discussed, as are the relevance and reliability of the numerical models for this endeavour.

Review of solutions for 3D hydrodynamic modeling applied to aquaculture in South Pacific atoll lagoons.

A workshop organized in French Polynesia in November 2004 allowed reviewing the current methods to model the three-dimensional hydrodynamic circulation in semi-enclosed atoll lagoons for aquaculture applications. Mollusk (e.g. pearl oyster, clam) aquaculture is a major source of income for South Pacific countries such as French Polynesia or Cook Islands. This aquaculture now requires a better understanding of circulation patterns to improve the spatial use of the lagoons, especially to define the best area to set larvae collectors. The pelagic larval duration of the relevant species (<20 days) and the size of the semi-closed lagoons (few hundreds of km2) drive the specifications of the model in terms of the spatial and temporal scale. It is considered that, in contrast with fish, mollusk larvae movements are limited and that their cycle occurs completely in the lagoon, without an oceanic stage. Atolls where aquaculture is productive are generally well-bounded, or semi-closed, without significant large and deep openings to the ocean. Nevertheless part of the lagoon circulation is driven by oceanic water inputs through the rim, ocean swells, tides and winds. Therefore, boundary conditions of the lagoon system are defined by the spatial structure of a very shallow rim (exposition and number of hoas), the deep ocean swell climate, tides and wind regimes. To obtain a realistic 3D numerical model of lagoon circulation with adequate forcing, it is thus necessary to connect in an interdisciplinary way a variety of methods (models, remote sensing and in situ data collection) to accurately represent the different components of the lagoon system and its specific boundary conditions. We review here the current methods and tools used to address these different components for a hypothetical atoll of the Tuamotu Archipelago (French Polynesia), representative of the semi-closed lagoons of the South Pacific Ocean. We hope this paper will serve as a guide for similar studies elsewhere and we provide guidelines in terms of costs for all the different stages involved.

[Seasonal evolution of the biogeochemical cycle in the southwest lagoon of New Caledonia. Application of a compartmental model]. / Evolution saisonnière du cycle biogéochimique dans le lagon sud-ouest de Nouvelle-Calédonie. Application d'un modèle compartimental.

A biogeochemical box model describing the south-west lagoon of New-Caledonia was developed in order to simulate the seasonal cycle of carbon and nitrogen. We used fluxes generated by a 3D hydrodynamic model to simulate horizontal exchanges between boxes and added freshwater influxes as nitrogen sources from the land. Average residence time proved to be less than 11 days for the lagoon as a whole. Standard simulations showed baseline values of chlorophyll a between 0.2 and 0.4 microgram.L-1. Influences of freshwater influxes proved to be significant (increases up to 1 microgram.L-1) only in shallow areas protected from wind exposure and during short periods of heavy rainfall (tropical depressions). Tropical climatic events have reduced impact in space and time and long-term simulations over decades with increased nutrient inputs did not show any significant process of eutrophication. Hydrodynamics seemed to be one of the major control factors with respect to organic matter cycling in the lagoon.

Cognitive impairments induced by triazolam in healthy volunteers: antagonism by a partial inverse agonist of benzodiazepine receptor.

Pharmacological studies revealed that SR 25776 possesses marked stimulant activity characteristic of a partial inverse agonist of benzodiazepine receptor. The effects of SR 25776 500 mg alone and in combination with triazolam 0.25 mg on psychomotor performance and memory were assessed in 8 healthy consenting male volunteers in a double-blind placebo controlled trial. Treatment effects were monitored before and two and half hours following oral medication. The present study suggest that at the studied dose SR 25776 may incompletely antagonize the sedative and amnesic effects of a benzodiazepine agonist without producing marked effects of its own.

[Bladder leiomyomas and fibromas. Apropos of 8 cases]. / Léiomyomes et fibromes vésicaux. A propos de huit cas.

Eight cases of benign mesothelial tumors of the bladder are reviewed (7 leiomyomas and 1 fibroma). The authors describe the pathological and clinical features and the various possibilities of diagnosis of these uncommon tumors. The treatment is exclusively surgical and the prognosis is good in every case.

Effects of Marine Bacteria on the Culture of Axenic Oyster Crassostrea gigas (Thunberg) Larvae.

Bacteria-free oyster larvae (Crassostrea gigas) were cultured under aseptic conditions; they were fed axenic algae (Isochrysis galbana), and the medium was inoculated with isolated strains of marine bacteria. Twenty-one bacterial strains were tested, and most were detrimental to larval survival and growth. However, additions of strain CA2 consistently enhanced larval survival (21-22%) and growth (16-21%) in comparison with control cultures that were fed only algae. Size-frequency distributions of populations of larvae cultured for 10 days on axenic algae were skewed due to the poor growth of many individuals; whereas size-frequencies from populations of larvae fed axenic algae supplemented with CA2 bacteria were distributed normally. Strain CA2 may therefore make a nutritional contribution to the growth of oyster larvae. I. galbana did not grow under the light intensities used for larval culture; thus the improvement in larval growth cannot be attributed to bacterial enhancement of algal growth and, consequently, food availability. Naturally occurring microflora from Yaquina Bay, Oregon, depressed survival or growth of larvae-fed live algae.

Influence of environmental factors on suicidal behavior.

The regional distribution of completed suicide was analyzed in 19 regions of France for the years 1975 and 1983. The regional distributions of environmental variables (ambient temperature, sunlight duration, and precipitation) and of sociological factors (social cohesion, socioeconomic status, status of women, and social support) were then correlated using Pearson coefficients, stepwise regression analysis, and partial correlations. Our main finding is that environmental factors such as ambient temperature may play a role in the regional distribution of completed suicide in France. Both the stepwise regression analysis and the controlled regression analysis revealed that, among all the variables studied (environmental and sociological), the main factors affecting the regional distribution of suicide were ambient temperature and sunlight duration. To our knowledge, this is the first detailed study demonstrating a clear relationship between environmental variables and suicidal behavior. The finding may be consistent with the recent description of forms of affective disorders occurring in relationship to environmental factors.

Circadian variation of plasma homovanillic acid levels is attenuated by fluphenazine in patients with schizophrenia.

Plasma homovanillic acid (HVA) levels were measured hourly for a 24-hour period in 10 patients with schizophrenia during treatment with placebo and fluphenazine. Ten age- and sex-matched normal volunteers were similarly studied. Diet and activity were carefully controlled and monitored in both patients and controls. A circadian rhythm of the plasma HVA level was found in controls with a nadir in the afternoon and peak values in the early morning hours; when the patients were free from drugs, they showed a similar rhythm with lower amplitudes. Fluphenazine treatment significantly reduced the plasma concentrations of HVA and abolished the 24-hour rhythm. These data suggest that a 24-hour rhythm of the plasma HVA level exists in humans and that the amplitude of this rhythm may be less pronounced in patients with schizophrenia. Treatment with neuroleptic drugs reduces both the absolute levels and the normal circadian rhythm of the plasma HVA level.

Repeated naloxone administration in schizophrenia: a phase II World Health Organization Study.

In the context of a previous WHO collaborative study, six research centers reported that naloxone (0.3 mg/kg) produced significant improvement in symptomatology in neuroleptic-treated patients. In the current Phase II WHO study, repeated (4 days) naloxone (0.3 mg/kg) administration was performed in schizophrenic patients (n = 43) from five WHO collaborating centers using a double-blind, placebo-controlled design. Both naloxone and placebo administrations were associated with significant reductions in symptoms. Naloxone, however, was not superior to placebo. These data are discussed in relation to endorphin hypotheses of schizophrenia.

Median eminence dopamine and serotonin neuronal activity. Temporal relationship to preovulatory prolactin and luteinizing hormone surges.

Using a high-performance liquid chromatography (HPLC) system coupled with an electrochemical detector, the concentrations of dopamine (DA) and 5-hydroxytryptamine (5-HT) and their major specific metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindole-3-acetic acid (5-HIAA), respectively, were measured in the median eminence (ME) throughout the rat estrous cycle. The ME DA content remained fairly constant throughout the estrous cycle except on estrus when 17.00 h values were significantly lower than 10.00 h values (40% decrease, p less than 0.05). The ME 5-HT content determined at 10.00 h was higher on proestrus than on any other day of the cycle. The ME DOPAC concentrations did not differ between 10.00 and 17.00 h on diestrus I, diestrus II or estrus. On the contrary, there was an almost linear decline between 10.00 and 17.00 h on proestrus (36% decrease, p less than 0.05). The ME 5-HIAA content did not differ between 10.00 and 17.00 h on any day of the estrous cycle. Significant changes were recorded for the DOPAC/DA and 5-HIAA/5-HT ratio in the ME on proestrus. There was a progressive decrease, starting from 10.00 h in the DOPAC/DA ratio with minimal values (42% decrease, p less than 0.05) at 16.00 h followed by an increase from 16.00 to 19.00 h. On the other hand, the 5-HIAA/5-HT ratio increased between 10.00 and 17.00 h (97% increase, p less than 0.05) and subsequently declined until 19.00 h (67% decrease vs. 17.00 h, p less than 0.05).2+hese data show that a concomitant

Seasonality of suicides: environmental, sociological and biological covariations.

The monthly rates of completed suicides in France from 1978 until 1982 were analyzed. The seasonal variations of environmental (daylight and sunlight durations, mean temperature, geomagnetism), sociological (unemployment, deaths of all causes, birth and conception rates), and biological (melatonin, cortisol and serotonin circannual rhythms) factors were compared to the seasonal patterns of suicides. A clear seasonal variation (with peaks in May and September) in suicidal behavior was detected. These patterns tended to differ as a function of age (bimodal in young, unimodal in old people). The component analysis clearly pointed out that seasonal patterns of suicides may be considered as the sum of two components, unimodal and bimodal. Almost similar covariations were found between the main seasonal (unimodal) component of suicides and environmental (daylight duration and mean monthly temperature) or sociological factors whereas the secondary component was more correlated to variations in environmental factors and, to some extent, to biological parameters.

MPP+ (1-methyl-4-phenylpyridine) is a neurotoxin to dopamine-, norepinephrine- and serotonin-containing neurons.

1-Methyl-4-phenylpyridine (MPP+) is an oxidative metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydroxypyridine (MPTP). MPP+ produced local cell death when injected directly into substantia nigra compacta, locus coeruleus, or dorsal and median raphe nuclei of rats. Corresponding significant decreases in dopamine, serotonin and norepinephrine levels were observed in the terminal areas. These observations indicate that MPP+ is a non-selective neurotoxin which causes lesions not only in dopaminergic neurons but also in noradrenergic and serotonergic systems following intracranial administration. Selective lesioning of these monoaminergic systems could only be achieved by a stereotaxic injection of MPP+ into specific brain regions containing monoamine neurons.

Urinary monoamines and monoamine metabolites in subtypes of unipolar depressive disorder and normal controls.

An examination was made of urinary catecholamine and metabolite outputs in 28 unipolar depressed patients and 25 normal controls. The total group of depressed patients had significantly higher urinary outputs of norepinephrine (NE) and its metabolite normetanephrine (NM), and significantly lower urinary outputs of the dopamine metabolite dihydroxyphenylacetic acid (DOPAC), than controls. Patients who met DSM-III criteria for a major depressive episode with melancholia (N = 8) had significantly higher urinary outputs of normetanephrine than controls, whereas patients with a major depressive episode without melancholia (N = 7) and dysthymic disorder patients (N = 8) had levels comparable with controls. We postulate that the higher urinary outputs of norepinephrine and its metabolite, normetanephrine, reflect dysregulation of the sympathetic nervous system in depression.

Tardive dyskinesia: relation to computer-tomographic, endocrine, and psychopathological variables.

Severity of tardive dyskinesia (TD) and psychopathology of 36 chronic schizophrenic patients under long-term treatment with neuroleptics (NL) was rated during NL therapy and again 12 days after NL withdrawal. Both times serum levels of prolactin, norepinephrine, beta-endorphin, and cortisol were determined. In 27 of these patients ventricular-brain ratio, width of third ventricle, maximal width of anterior horns, distance between choroid plexus, and width of four largest sulci were also measured. Fifteen patients had no signs of TD; 14 had moderate, and 7 severe TD. TD was not related to age, age at onset of illness, duration of illness, dosage and type of neuroleptics, number of ECTs, or any endocrine variable. Psychopathology was barely related to TD, but after NL withdrawal, patients with TD tended to show more deterioration, particularly with regard to thought disorder and activation. With regard to computer-tomographic (CT) variables, patients without TD showed significantly less sulcal enlargement than those with TD. These results indicate that individual predisposition, which may have led to the development of TD, also seems to involve a higher risk of relapse after NL withdrawal.

[Length of hospitalization and quality of care in a department of pediatrics. Results of a prospective study (author's transl)]. / Durée de séjour hospitalier et qualité des soins en pédiatrie. Résultats d'une étude prospective.

The records of 150 patients hospitalized in a department of specialized pediatrics were analysed immediately after discharge, in order to detect the factors involved in the length of stay. Unexpected course of the disease and familial factors most often increase the length of an hospitalization programed according to technical factors. The interactions between quality of care and length of stay are discussed.