Chemical weathering and CO2 consumption in the upper Nyong Basin rivers (Central Africa): Insights on climatic and anthropogenic forcing in humid tropical environments.

A hydrological and hydrochemical database (produced by the M-TROPICS critical zone observatory) in the upper Nyong Basin from 1998 to 2017 was used to evaluate the river's response to climatic and anthropogenic forcing and examine chemical weathering processes. SiO2 and HCO3- constitute about 85 % of the Total dissolved solids (TDS) load, equivalent to 0.12 × 109 kg. y-1. Electrical conductivity (EC), Total dissolved solids (TDS), major cations, major anions (except F- and NO3-) and alkalinity (Alk) vary seasonally and follow a predictable model with discharge. Atlantic Meridional Mode oscillation controls the long-term water chemistry. Atmospheric input and silicate weathering are the main factors influencing the Nyong rivers chemistry. However, several indices supported the progressive water quality deterioration by human activities, namely: the excess of Cl- and SO42- after the substraction of atmospheric inputs, the basic pH observed for specific samples, long-term increase in the values of pH, EC, TDS, EC, Mg2+, Ca2+, F-, NO3-, HCO3-, Alk, SiO2 and Dissolved Organic Carbon. Runoff and physical erosion have an important control on chemical erosion in the upper Nyong Basin rivers. The chemical erosion rate (3.3 t.km-2.y-1) equals the silicate weathering rate. The CO2 consumption rate, in the Nyong rivers, is lower than the global average (98× 103 for silicate weathering and 246 × 103 mol.km-2.y-1 for chemical erosion) and estimated at 52.3 × 103 for silicate weathering and 54.1 × 103 mol.km-2.y-1 for chemical erosion. At Olama, the most downstream location of the monitoring setup, the Nyong River Basin consumed 1 × 109 mol.y-1 of CO2 by chemical erosion.

Socio-Ecological Approach to a Forest-Swamp-Savannah Mosaic Landscape Using Remote Sensing and Local Knowledge: a Case Study in the Bas-Ogooué Ramsar Site, Gabon.

Studies of landscape dynamics in protected areas often rely exclusively on remotely-sensed data, leading to bias by neglecting how local inhabitants, who often have a long history of interaction with their environment, perceive and structure the landscape over time. Using a socio-ecological system (SES) approach in a forest-swamp-savannah mosaic within the Bas-Ogooué Ramsar site in Gabon, we assess how human populations participate in landscape dynamics over time. We first conducted a remote sensing analysis to produce a land-cover map representing the biophysical dimension of the SES. This map is based on pixel-oriented classifications, using a 2017 Sentinel-2 satellite image and 610 GPS points, that categorized the landscape in 11 ecological classes. To study the landscape's social dimension, we collected data on local knowledge to understand how local people perceive and use the landscape. These data were collected through 19 semi-structured individual interviews, three focus groups and 3 months of participant observation during an immersive field mission. We developed a systemic approach by combining data on biophysical and social dimensions of the landscape. Our analysis shows that in the absence of continued anthropic interventions, both savannahs and swamps dominated by herbaceous vegetation will experience closure by encroaching woody vegetation, leading to eventual biodiversity loss. Our methodology based on an SES approach to landscapes could improve the conservation programs developed by Ramsar site managers. Designing actions at the local scale, rather than applying one set of actions to the entire protected area, allows the integration of human perceptions, practices and expectations, a challenge that is more than essential in the context of global change.

Ecological plasticity to ions concentration determines genetic response and dominance of Anopheles coluzzii larvae in urban coastal habitats of Central Africa.

In Central Africa, the malaria vector Anopheles coluzzii is predominant in urban and coastal habitats. However, little is known about the environmental factors that may be involved in this process. Here, we performed an analysis of 28 physicochemical characteristics of 59 breeding sites across 5 urban and rural sites in coastal areas of Central Africa. We then modelled the relative frequency of An. coluzzii larvae to these physicochemical parameters in order to investigate environmental patterns. Then, we assessed the expression variation of 10 candidate genes in An. coluzzii, previously incriminated with insecticide resistance and osmoregulation in urban settings. Our results confirmed the ecological plasticity of An. coluzzii larvae to breed in a large range of aquatic conditions and its predominance in breeding sites rich in ions. Gene expression patterns were comparable between urban and rural habitats, suggesting a broad response to ions concentrations of whatever origin. Altogether, An. coluzzii exhibits a plastic response to occupy both coastal and urban habitats. This entails important consequences for malaria control in the context of the rapid urban expansion in Africa in the coming years.

Reproduction Function in Male Patients With Bardet Biedl Syndrome.

PURPOSE: Bardet-Biedl syndrome (BBS) is a ciliopathy with a wide spectrum of symptoms due to primary cilia dysfunction, including genitourinary developmental anomalies as well as impaired reproduction, particularly in males. Primary cilia are known to be required at the following steps of reproduction function: (i) genitourinary organogenesis, (ii) in fetal firing of hypothalamo-pituitary axe, (iii) sperm flagellum structure, and (iv) first zygotic mitosis conducted by proximal sperm centriole. BBS phenotype is not fully understood. METHODS: This study explored all steps of reproduction in 11 French male patients with identified BBS mutations. RESULTS: BBS patients frequently presented with genitourinary malformations, such as cryptorchidism (5/11), short scrotum (5/8), and micropenis (5/8), but unexpectedly, with normal testis size (7/8). Ultrasonography highlighted epididymal cysts or agenesis of one seminal vesicle in some cases. Sexual hormones levels were normal in all patients except one. Sperm numeration was normal in 8 out of the 10 obtained samples. Five to 45% of sperm presented a progressive motility. Electron microscopy analysis of spermatozoa did not reveal any homogeneous abnormality. Moreover, a psychological approach pointed to a decreased self-confidence linked to blindness and obesity explaining why so few BBS patients express a child wish. CONCLUSIONS: Primary cilia dysfunction in BBS impacts the embryology of the male genital tract, especially epididymis, penis, and scrotum through an insufficient fetal androgen production. However, in adults, sperm structure does not seem to be impacted. These results should be confirmed in a greater BBS patient cohort, focusing on fertility.

Polar pesticide contamination of an urban and peri-urban tropical watershed affected by agricultural activities (Yaoundé, Center Region, Cameroon).

Urban agriculture is crucial to local populations, but the risk of it contaminating water has rarely been documented. The aim of this study was to assess pesticide contamination of surface waters from the Méfou watershed (Yaoundé, Cameroon) by 32 selected herbicides, fungicides, and insecticides (mainly polar) according to their local application, using both grab sampling and polar organic compounds integrative samplers (POCIS). Three sampling campaigns were conducted in the March/April and October/November 2015 and June/July 2016 rainy seasons in urban and peri-urban areas. The majority of the targeted compounds were detected. The quantification frequencies of eight pesticides were more than 20% with both POCIS and grab sampling, and that of diuron and atrazine reached 100%. Spatial differences in contamination were evidenced with higher contamination in urban than peri-urban rivers. In particular, diuron was identified as an urban contaminant of concern because its concentrations frequently exceeded the European water quality guideline of 0.200 µg/L in freshwater and may thus represent an ecological risk due to a risk quotient > 1 for algae observed in 94% of grab samples. This study raises concerns about the impacts of urban agriculture on the quality of water resources and to a larger extent on the health of the inhabitants of cities in developing countries. Graphical abstract ᅟ.

Groundwater resource vulnerability and spatial variability of nitrate contamination: Insights from high density tubewell monitoring in a hard rock aquifer.

Agriculture has been increasingly relying on groundwater irrigation for the last decades, leading to severe groundwater depletion and/or nitrate contamination. Understanding the links between nitrate concentration and groundwater resource is a prerequisite for assessing the sustainability of irrigated systems. The Berambadi catchment (ORE-BVET/Kabini Critical Zone Observatory) in Southern India is a typical example of intensive irrigated agriculture and then an ideal site to study the relative influences of land use, management practices and aquifer properties on NO3 spatial distribution in groundwater. The monitoring of >200 tube wells revealed nitrate concentrations from 1 to 360mg/L. Three configurations of groundwater level and elevation gradient were identified: i) NO3 hot spots associated to deep groundwater levels (30-60m) and low groundwater elevation gradient suggest small groundwater reserve with absence of lateral flow, then degradation of groundwater quality due to recycling through pumping and return flow; ii) high groundwater elevation gradient, moderate NO3 concentrations suggest that significant lateral flow prevented NO3 enrichment; iii) low NO3 concentrations, low groundwater elevation gradient and shallow groundwater indicate a large reserve. We propose that mapping groundwater level and gradient could be used to delineate zones vulnerable to agriculture intensification in catchments where groundwater from low-yielding aquifers is the only source of irrigation. Then, wells located in low groundwater elevation gradient zones are likely to be suitable for assessing the impacts of local agricultural systems, while wells located in zones with high elevation gradient would reflect the average groundwater quality of the catchment, and hence should be used for regional mapping of groundwater quality. Irrigation with NO3 concentrated groundwater induces a "hidden" input of nitrogen to the crop which can reach 200kgN/ha/yr in hotspot areas, enhancing groundwater contamination. Such fluxes, once taken into account in fertilizer management, would allow optimizing fertilizer consumption and mitigate high nitrate concentrations in groundwater.

A new, faster, and safe nasal provocation test method for diagnosing mite allergic rhinitis.

BACKGROUND: Diagnosing house dust mite (HDM) allergic rhinitis is difficult. The nasal provocation test (NPT) has been shown to be the most pertinent, but several methods are available. According to guidelines, the NPT requires a skin end-point titration and an objective measurement of nasal patency. Hence, NPT is time consuming and its use is limited. OBJECTIVE: To evaluate the sensitivity, specificity, and safety of a new, more rapid, and simple alternative NPT (NPT-R) to HDM. METHODS: Eighty-eight patients with from rhinitis (49 allergic to HDM and 39 controls with and without atopy) were included. Allergic rhinitis to HDM was confirmed by a "classic" NPT based on the Lebel score and rhinomanometry. After a period of 4 weeks, NPT-R was performed and only the clinical score was measured. RESULTS: The study population was young (mean ± SD, 27.7 ± 8.5 years old), composed mostly of women (61 vs 27 men), and 24% reported asthma. The sensitivity and specificity of NPT-R were 83.7% and 100%, respectively. The correlation between the NPTs was statistically significant (0.833, P < .0001, n = 88) and the 2 NPTs were completely safe. Performing NPT-R was more rapid (mean ± SD, 22 ± 8 minutes) than the classic NPT (97 ± 20 minutes). CONCLUSION: The NPT-R is safe and easier and faster than the classic NPT. This new method appears to be a very useful tool in the diagnosis of HDM allergic rhinitis when the diagnosis is uncertain or before initiating immunotherapy. TRIAL REGISTRATION: ClinicalTrials.gov, identifier NCT01485523.

Assessment of disease control in allergic rhinitis.

The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative has had a significant impact, by raising awareness of allergic rhinitis (AR) and improving the diagnosis and treatment of AR sufferers. ARIA classifies the severity of AR as "mild" or "moderate/severe" on the basis of "yes"/"no" answers to four questions. This two-point classification has been criticized as providing little guidance on patient management; patients with "mild" AR are unlikely to consult a physician, whereas the group of patients with "moderate/severe" seen by specialists is heterogeneous. These perceived shortcomings have prompted attempts to improve the ARIA classification or, by analogy with the Global Initiative for Asthma (GINA), adopt approaches based on "disease control" in AR. Even though "disease severity", "disease control" and "responsiveness to treatment" are different (albeit related) metrics, they are not mutually exclusive. Currently, there is no single, accepted definition, but we propose that "disease control" in AR can combine (i) measurements of the severity and/or frequency of daily or nocturnal symptoms, (ii) impairments in social, physical, professional and educational activities, (iii) respiratory function monitoring and (iv) exacerbations (e.g. unscheduled medical consultations and rescue medication use). Although control-based classifications have a number of limitations (e.g. their dependence on treatment compliance and the patient's psychological status), these instruments could be used as an adjunct to the ARIA severity classification and regional practice parameters. Here, we assess the strengths and weaknesses of the current two-level ARIA classification, analyze published proposals for its modification and review the literature on instruments that measure AR control. We conclude that there is a need for research in which severity is compared with control in terms of their effects on patient management.

MRI in respiratory epithelial adenomatoid hamartoma of nasal cavities.

This is a report of six cases of respiratory epithelial adenomatoid hamartoma of the nasal cavities that were characterized by: symptoms of nasal obstruction and dysosmia; endoscopic appearances of bilateral nasal polyposis affecting the olfactory clefts; CT imaging showing enlargement of the olfactory clefts; MRI (rarely reported in the literature) revealing clearly delineated cerebriform tissue filling in the olfactory clefts; histological confirmation in all cases; and recovery after surgical endoscopic resection without the need for associated sinus surgery.

18F-FDG PET/CT in sarcoidosis management: review and report of 20 cases.

PURPOSE: To evaluate the interest of (18)F-fluoro-2-deoxy-D: -glucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) for diagnosis and therapeutic follow-up of patients with sarcoidosis. METHODS: Twenty consecutive patients with biopsy-proven sarcoidosis were retrospectively included, in particular, 13 and seven cases of thoracic and extra-thoracic sarcoidosis, respectively. All patients underwent (18)F-FDG PET/CT, and 12 of them also (67)Ga scintigraphy. Five patients were re-examined by (18)F-FDG PET/CT to assess response to corticosteroid (CS) treatment. RESULTS: Sensitivity of (18)F-FDG PET/CT in detecting active sarcoidosis localizations was determined considering only biopsy-proven sites. For thoracic, sinonasal, and pharyngo-laryngeal localizations, (18)F-FDG PET/CT sensitivity was 100%, 100%, and 80%, respectively. Overall sensitivity for all 36 biopsy-proven localizations improved from 78% to 87% after excluding skin involvement. Considering only the 12 patients who underwent both scintigraphic examinations, overall sensitivity of (67)Ga scintigraphy and (18)F-FDG PET/CT was 58% and 79%, respectively and improved to 67% and 86% after excluding all sites of skin involvement. To evaluate the efficacy of CS treatment, five enrolled patients underwent second (18)F-FDG PET/CT. Complete regression of all foci of pathological tracer uptake was showed in two cases, permitting CS withdrawal after 2 and 6 months. Improvement but incomplete regression of mediastino-pulmonary disease occurred in two patients treated with CS for 19 and 21 months. Disease progression was assessed in one patient treated with decreasing doses of CS during 16 months. CONCLUSION: (18)F-FDG PET/CT allows to obtain a complete morpho-functional cartography of inflammatory active localizations and to follow treatment efficacy in patients with sarcoidosis, particularly in atypical, complex, and multisystemic forms.

Allergic fungal sinusitis associated with allergic bronchopulmonary aspergillosis: an uncommon sinobronchial allergic mycosis.

BACKGROUND: The identification of allergic fungal sinusitis (AFS) is still controversial and much more recent than that of allergic bronchopulmonary aspergillosis (ABPA). Their association has been reported very rarely in the literature. METHODS: The aim of this study was to present a review of 6 cases of AFS associated with ABPA from a series of 12 cases of AFS and to compare AFS associated with ABPA and isolated AFS. RESULTS: All cases of AFS presented with chronic rhinosinusitis. The six cases with AFS and ABPA were atopic, asthmatic, with pulmonary infiltrates (five cases), central bronchiectasis (four cases), and both (three cases). The mycological and immunoallergological features of isolated AFS and AFS associated with ABPA were similar: eosinophilic allergic mucin with noninvasive fungi hyphae, high levels of blood eosinophils, total IgE, specific IgE, IgG, and positive skin tests to Aspergillus. The association of AFS and ABPA was concomitant (two cases) or remote in time (four cases). The treatment with oral corticosteroids and sinus surgery (six cases) associated with antifungal drugs (four cases) led to resolution in three cases, considerable improvement in one case, and therapeutic failure in two cases (follow-up longer than 5 years in all cases). CONCLUSION: Independently of the signs linked to the organs involved (sinuses and bronchi) the mycological and immunoallergological features were similar for AFS and AFS associated with ABPA. AFS and ABPA can be isolated or associated in a sinobronchial allergic

Resolution of MRS applied to the characterization of hard-rock aquifers.

The performance of the Magnetic Resonance Sounding (MRS) method applied to the investigation of heterogeneous hard-rock aquifers was studied. It was shown using both numerical modeling and field measurements that MRS could be applied to the investigation of the weathered part of hard-rock aquifers when the product of the free water content multiplied by the thickness of the aquifer is >0.2 (for example, 10-m-thick layer with a 2% water content). Using a currently available one-dimensional MRS system, the method allows the characterization of two-dimensional subsurface structures with acceptable accuracy when the size of the subsurface anomaly is equal to or greater than the MRS loop. However, the fractured part of hard-rock aquifers characterized by low effective porosity (<0.5%) cannot be resolved using currently available MRS equipment. It was found that shallow water in the weathered part of the aquifer may screen MRS signals from deeper water-saturated layers, thus further reducing the possibility of investigating deeper fractured aquifers. A field study using the NUMIS(plus) MRS system developed by IRIS Instruments was carried out on an experimental watershed in southern India. A heterogeneous unconfined aquifer in a gneissic formation was successfully localized, and MRS results were confirmed by drilling shortly after the geophysical study. The top of the aquifer revealed by MRS was found to be in a good agreement with observed static water level measurements in boreholes.

Sinonasal sarcoidosis: review and report of fifteen cases.

OBJECTIVES: Sinonasal sarcoidosis remains a poorly understood and uncommon chronic granulomatous disease of unclear origin. We have attempted to characterize the main clinical and radiologic criteria for diagnosis and to discuss the treatment. METHODS: A retrospective study of 15 cases of chronic, symptomatic, and biopsy-proven sinonasal sarcoidosis and a review of the literature are realized. RESULTS: Among the 15 patients, there were 8 women and 7 men with a mean age of 44 years. The most frequent presentation was a chronic, often crusty, rarely destructive inflammatory rhinosinusitis with nodules on the septum and/or the turbinates. Pulmonary sarcoidosis was associated in 12 cases. Involvement of the nasopharynx, the pharyngolarynx, the skin, the lachrymal and salivary glands, and the liver was associated in some cases. Levels of angiotensin-converting enzyme were elevated in 10 cases and normal in 3 cases. Gallium scan performed in three cases was positive. Radiologic studies showed nodules on the septum and/or the turbinates in 14 cases, complete or subtotal opacification of the sinuses and/or the nasal cavities in 13 cases, and nasopharyngeal or pharyngolaryngeal lesions in 4 cases. Treatment with corticosteroids, methotrexate, azathioprine, and surgery appear globally disappointing in view of the side effects and the relapses during a long follow-up (3-15 yr; mean, 6 yr). CONCLUSION: On the basis of this study, we propose the following diagnostic criteria: 1) histopathologic confirmation of noncaseating granuloma; 2) chronic rhinosinusitis poorly responsive to conventional treatment and radiologic evidence of rhinosinusitis, often with nodules on the septum and/or the turbinates; 3) elevated level of angiotensin-converting enzyme; 4) positive gallium scan (if performed); 5) frequent evidence of systemic, especially pulmonary, sarcoidosis; 6) no evidence of other granulomatous diseases, such as Wegener granulomatosis.