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Before the 2015 implementation of "Test and Start," the initiation of combination antiretroviral therapy (ART) was guided by specific CD4 cell count thresholds. As scale-up efforts progress, the prevalence of advanced HIV disease at ART initiation is expected to decline. We analyzed the temporal trends in the median CD4 cell counts among adults initiating ART and described factors associated with initiating ART with severe immunodeficiency in Zambézia Province, Mozambique. We included all HIV-positive, treatment-naive adults (age ≥ 15 years) who initiated ART at a Friends in Global Health (FGH)-supported health facility between September 2012 and September 2017. Quantile regression and multivariable logistic regression models were applied to ascertain the median change in CD4 cell count and odds of initiating ART with severe immunodeficiency, respectively. A total of 68,332 patients were included in the analyses. The median change in CD4 cell count under "Test and Start" was higher at +68 cells/mm3 (95% CI: 57.5–78.4) compared with older policies. Younger age and female sex (particularly those pregnant/lactating) were associated with higher median CD4 cell counts at ART initiation. Male sex, advanced age, WHO Stage 4 disease, and referrals to the health facility through inpatient provider-initiated testing and counseling (PITC) were associated with higher odds of initiating ART with severe immunodeficiency. Although there were reassuring trends in increasing median CD4 cell counts with ART initiation, ongoing efforts are needed that target universal HIV testing to ensure the early initiation of ART in men and older patients. [ABSTRACT FROM AUTHOR]

δ 15 N of annual ( Ulva sp., Porphyra sp.) and perennial intertidal seaweed species ( Chondrus crispus , Fucus sp.) collected on 17 sampling points along the French coast of the English Channel in 2012 and 2013 were assessed on their suitability as bioindicators of N pollution in coastal areas. A sine function applied for δ 15 N time series data showed for all the species the same seasonal trend with lowest δ 15 N values in April and highest in summer but with no significant interspecific differences of amplitude (α) and phase angle (ϕ). This model provides a useful tool for monitoring the inter-annual changes of N pollution. An interspecific variability of δ 15 N values was observed, probably due to their tolerance to emersion. An in vitro study for comparing the kinetic acquisition of the isotopic signal and N uptake mechanisms of each species underlined the influence of algal physiology on the δ 15 N interspecific variability. [ABSTRACT FROM AUTHOR]

The English Channel hosts a high density of human activities, which result in strong pressures and impacts on its marine ecosystem. The European Union's INTERREG programme funds projects to promote sustainable development through ecosystem-based management and the development of socio-economic services in the Channel region. An analysis of the themes studied during INTERREG IVA projects to date reveals both gaps that should be addressed in the future, as well as good practices that should be maintained and promoted. This analysis was used to provide advice and recommendations on knowledge gaps which may form the foundation of future projects for European programmes such as those in the next INTERREG project call (2015–2020). [ABSTRACT FROM AUTHOR]

A fine-scale survey of δ 15 N, δ 13 C, tissue-N in seaweeds was conducted using samples from 17 sampling points at two sites (Grandcamp-Maisy (GM), Courseulles/Mer (COU)) along the French coast of the English Channel in 2012 and 2013. Partial triadic analysis was performed on the parameter data sets and revealed the functioning of three areas: one estuary (EstA) and two rocky areas (GM ∗ , COU ∗ ). In contrast to oceanic and anthropogenic reference points similar temporal dynamics characterized δ 15 N signatures and N contents at GM ∗ and COU ∗ . Nutrient dynamics were similar: the N-concentrations in seawater originated from the River Seine and local coastal rivers while P-concentrations mainly from these local rivers. δ 15 N at GM ∗ were linked to turbidity suggesting inputs of autochthonous organic matter from large-scale summer seaweed beachings made up of a mixture of Rhodophyta, Phaeophyta and Chlorophyta species. This study highlights the coupling between seaweed beachings and nitrogen sources of intertidal macroalgae. [ABSTRACT FROM AUTHOR]

As one of the busiest marine ecosystems in the world, the English Channel is subjected to strong pressures due to the human activities occurring within it. Effective governance is required to improve the combined management of different activities and so secure the benefits provided by the Channel ecosystem. In July 2014, a Cross-Channel Forum, entitled “Science and Governance of the Channel Marine Ecosystem”, was held in Caen (France) as part of the INTERREG project “Promoting Effective Governance of the Channel Ecosystem” (PEGASEAS). Here we use outputs from the Forum as a framework for providing Channel-specific advice and recommendations on marine governance themes, including the identification of knowledge gaps, which may form the foundation of future projects for the next INTERREG project call (2015–2020). [ABSTRACT FROM AUTHOR]

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Abstract: Atoll lagoons display a high diversity of trophic states due mainly to their specific geomorphology, and probably to their level and mode of human exploitation. We investigated the functioning of the Ahe atoll lagoon, utilized for pearl oyster farming, through estimations of photosynthetic parameters (pulse amplitude modulation fluorometry) and primary production (13C incorporation) measurements of the size structured phytoplankton biomass (<2μm and >2μm). Spatial and temporal scales of variability were surveyed during four seasons, over 16months, at four sites within the lagoon. While primary production (P) was dominated by the picophytoplankton, its biomass specific primary productivity (P B) was lower than in other atoll lagoons. The variables size fraction of the phytoplankton, water temperature, season, the interaction term station*fraction and site, explained significantly the variance of the data set using redundancy analysis. No significant trends over depth were observed in the range of 0–20m. A clear spatial pattern was found which was persistent over the seasons: south and north sites were different from the two central stations for most of the measured variables. This pattern could possibly be explained by the existence of water cells showing different water residence time within the lagoon. Photoacclimation strategies of the two size fractions differed through their light saturation coefficient (higher for picophytoplankton), but not through their maximum photosynthetic capacity (ETRmax). Positive linear relationships between photosynthetic parameters indicated that their dynamic was independent of light availability in this ecosystem, but most probably dependent on nutrient availability and/or rapid changes in the community structure. Spatial and temporal patterns of the measured processes are then further discussed in the context of nutrient availability and the possible role of cultured oysters in nutrient recycling. [Copyright &y& Elsevier]

Interactions between carbon and silica in the diatom frustule play an important role in carbon export through their impact on diatom remineralization (carbon degradation and biogenic silica dissolution). To ameliorate model prediction of the fate of Si and organic matter during sedimentation, there is a need to first understand the origin and nature of Si-OC interactions, their impact on diatom remineralization and their variability with environmental conditions. In this study we focus on the impact of nutrient starvations on the formation and nature of these interactions in an ubiquitous diatom, Thalassiosira weissflogii. Fluorescence reveals the strong impact of all starvations on diatom metabolism while Fourier transformed infrared (FTIR) spectroscopy clearly showed that starvations altered the composition of the different diatom fractions. The relative compositions of whole cells were almost not impacted by starvations except Si(OH)4 starvation that slightly increased proteins relative contribution while decreasing carbohydrate. Starvation impacts became obvious looking at the composition of the different part of the diatom. The relative biochemical composition of the organic coating, protecting the frustule from the environment, was strongly affected by starvation. Under nitrate starvation, carbohydrate contribution increased while protein contribution decreased. Inversely, phosphate starvation increased the proportion of proteins and decreased carbohydrates contribution. Starvations also modified the different frustule phases. bSiO2 contribution decreased in the less reactive phase under silicate and phosphate starvation whereas nitrate starvation rather increased carbohydrate and protein pools. Phosphate starvation also led to an important shift of dominance among protein groups between amide I and amide II which compounds are suspected to play a key role in the frustule synthesis and architecture. Nutrient starvations affected the relative biochemical composition of diatom frustule fractions and organic coating which could imply a strong impact on frustule structure and architecture but also on frustule mechanical and chemical resistance. [ABSTRACT FROM AUTHOR]

The article presents a study which aims to quantify the nitrate and ammonium uptake by intertidal microphytobenthos (MPB). It also seeks to determine the association of nutrient concentration, light availability, and migration in the assimilation of dissolved inorganic nitrogen (DIN) by MPB. To assess the nitrate and ammonium uptake kinetics by MPB, 15N stable isotopes technique on cell extracted from the sediment at the Nakdong River Estuary in Korea was employed. Results show that the uptake of ammonium by MPB under darkened conditions was lower than during light periods. Based on the findings, it proposes that the affinity of MPB for DIN may be associated to the environmental conditions to which they are exposed.

Silicon and carbon uptake rates were studied over a 24 h light/dark cycle in a synchronised culture of the marine diatomCylindrotheca fusiformis(Reimann et Lewin) using32Si and14C. The silicic acid uptake rate per cell (?cSi) varied between 1.2 and 20.0 fmol Si cell-1 h-1 and was closely correlated to the G2+M phase of the cell cycle. A linear and significant relationship was determined between the percentage of cells present in G2+M and?cSi. Evolution of the soluble free-silicon pool was studied simultaneously. The concentration of the total soluble free pool of silicon (QPSi) varied from 1% to 7% of the total silicon content. A significant difference of 1.5 fmol Si cell-1 betweenQPSi and the labelled free pool (QnpSi) was measured, indicating the presence of an unlabelled fraction of the pool. The concentration ofQnpSi was around 1.0 fmol Si cell-1 prior to cell division and did not change as a function of?cSi, which indicated a feedback mechanism coupling uptake into the free pool and incorporation into the frustule. In parallel,14C uptake variation (?cC) was measured during the division of the population. The value of?cC varied between 0.44 and 0.78 pmol C cell-1 h-1 and appeared to be maximal when cells were in the G1 phase. This variation of?cC marginally affected the total carbon content of the cells (QTC) in comparison with the light/dark cycle. The variations in the Si/C ratio, from 0.021 to 0.046, demonstrated the different control mechanisms of Si and C metabolisms during the course of the cell- and photocycle. [ABSTRACT FROM AUTHOR]