Eosinophilic meningitis: a case series and review of literature of Angiostrongylus cantonensis and Gnathostoma spinigerum.

Eosinophilic meningitis is defined as the presence of >10 eosinophils/µL in cerebrospinal fluid (CSF) or at least 10% eosinophils in the total CSF leukocyte count. Eosinophilic meningitis has been reported in two case series and two case reports in India till date and has not been reported in children below 15 years of age. We present two children with eosinophilic meningitis with peripheral eosinophilia and the proposed etiologic agents based on the clinical setting and their response to antihelminthic agents.

Making the case for multipurpose prevention technologies: the socio-epidemiological rationale.

This paper summarises the public health rationale for multipurpose prevention technologies (MPTs) by examining recent epidemiological data and trends in sexual and reproductive health indicators. MPTs are products that combine protection against unintended pregnancy, HIV and other sexually transmitted infections. The successful introduction of new woman-controlled MPTs provides a compelling response to the multiple sexual and reproductive health risks that women face worldwide.

Dynamic cystocolpoproctography is superior to functional pelvic MRI in the diagnosis of posterior pelvic floor disorders: results of a prospective study.

AIM: The accuracy of dynamic cystocolpoproctography (DCP) and dynamic MRI were compared in diagnosing posterior pelvic floor disorders. METHOD: Fifty consecutive female patients (mean age 51 years) complaining of posterior compartment pelvic floor disorder and referred to a tertiary centre entered the prospective study. The Institutional Review Board stated that informed consent from the patients was not necessary for this study. Patients underwent a DCP and a supine functional MRI by two different radiologists. Assessment of radiological examinations was prospective and blind. All patients underwent surgery that led to the final diagnosis. Agreement between the operative diagnosis and the diagnoses following DCP and MRI was assessed using the weighted kappa statistic. A matched-pairs McNemar's test was applied to demonstrate whether or not one radiological method was superior to the other. RESULTS: Full-thickness rectal prolapse was best diagnosed by clinical examination. Internal rectal prolapse and peritoneocele were best diagnosed by DCP. A better agreement with the operative diagnosis, which is not true superiority, was observed for DCP compared with functional pelvic MRI for full-thickness rectal prolapse, internal rectal prolapse and peritoneocele. There was no significant difference between DCP and functional pelvic MRI in the diagnosis of internal rectal prolapse (P = 0.125) or peritoneocele (P = 0.10). CONCLUSION: As full-thickness rectal prolapse, internal rectal prolapse and peritoneocele might be missed by functional pelvic MRI, there should still be a place for DCP in particular cases where the clinical diagnosis is not clear in women with symptomatic posterior pelvic floor disorders.

Plant preference for ammonium versus nitrate: a neglected determinant of ecosystem functioning?

Although nitrogen (N) availability is a major determinant of ecosystem properties, little is known about the ecological importance of plants' preference for ammonium versus nitrate (ß) for ecosystem functioning and the structure of communities. We modeled this preference for two contrasting ecosystems and showed that ß significantly affects ecosystem properties such as biomass, productivity, and N losses. A particular intermediate value of ß maximizes the primary productivity and minimizes mineral N losses. In addition, contrasting ß values between two plant types allow their coexistence, and the ability of one type to control nitrification modifies the patterns of coexistence with the other. We also show that species replacement dynamics do not lead to the minimization of the total mineral N pool nor the maximization of plant productivity, and consequently do not respect Tilman's R* rule. Our results strongly suggest in the two contrasted ecosystems that ß has important consequences for ecosystem functioning and plant community structure.

Amplifying the benefits of agroecology by using the right cultivars.

Tropical soils are particularly vulnerable to fertility losses due to their low capacity to retain organic matter and mineral nutrients. This urges the development of new agricultural practices to manage mineral nutrients and organic matter in a more sustainable way while relying less on fertilizer inputs. Two methods pertaining to ecological engineering and agroecology have been tested with some success: (1) the addition of biochar to the soil, and (2) the maintenance of higher earthworm densities. However, modern crop varieties have been selected to be adapted to agricultural practices and to the soil conditions they lead to and common cultivars might not be adapted to new practices. Using rice as a model plant, we compared the responsiveness to biochar and earthworms of five rice cultivars with contrasted selection histories. These cultivars had contrasted responsivenesses to earthworms, biochar, and the combination of both. The mean relative increase in grain biomass, among all treatments and cultivars, was 94% and 32%, respectively, with and without fertilization. Choosing the best combination of cultivar and treatment led to a more than fourfold increase in this mean benefit (a 437% and a 353% relative increase in grain biomass, respectively, with and without fertilization). Besides, the more rustic cultivar, a local landrace adapted to diverse and difficult conditions, responded the best to earthworms in terms of total biomass, while a modern common cultivar responded the best in term of grain biomass. This suggests that cultivars could be selected to amplify the benefit of biochar- and earthworm-based practices. Overall, selecting new cultivars interacting more closely with soil organisms and soil heterogeneity could increase agriculture sustainability, fostering the positive feedback loop between soils and plants that has evolved in natural ecosystems.

Evolution of nutrient acquisition: when adaptation fills the gap between contrasting ecological theories.

Although plant strategies for acquiring nutrients have been widely studied from a functional point of view, their evolution is still not well understood. In this study, we investigate the evolutionary dynamics of these strategies and determine how they influence ecosystem properties. To do so, we use a simple nutrient-limited ecosystem model in which plant ability to take up nutrients is subject to adaptive dynamics. We postulate the existence of a trade-off between this ability and mortality. We show that contrasting strategies are possible as evolutionary outcomes, depending on the shape of the trade-off and, when nitrogen is considered as the limiting nutrient, on the intensity of symbiotic fixation. Our model enables us to bridge these evolutionary outcomes to classical ecological theories such as Hardin's tragedy of the commons and Tilman's rule of R*. Evolution does not systematically maximize plant biomass or primary productivity. On the other hand, each evolutionary outcome leads to a decrease in the availability of the limiting mineral nutrient, supporting the work of Tilman on competition between plants for a single resource. Our model shows that evolution can be used to link different classical ecological results and that adaptation may influence ecosystem properties in contrasted ways.

Comparing the performances of Diggle's tests of spatial randomness for small samples with and without edge-effect correction: application to ecological data.

Diggle's tests of spatial randomness based on empirical distributions of interpoint distances can be performed with and without edge-effect correction. We present here numerical results illustrating that tests without the edge-effect correction proposed by Diggle (1979, Biometrics 35, 87-101) have a higher power for small sample sizes than those with correction. Ignoring the correction enables detection of departure from spatial randomness with smaller samples (down to 10 points vs. 30 points for the tests with correction). These results are confirmed by an example with ecological data consisting of maps of two species of trees in a West African savanna. Tree numbers per species per map were often less than 20. For one of the species, for which maps strongly suggest an aggregated pattern, tests without edge-effect correction enabled rejection of the null hypothesis on three plots out of five vs. on only one for the tests with correction.

Stoichiometry of a recombinant GABAA receptor.

GABA is the main inhibitory neurotransmitter in the mammalian brain. The postsynaptic GABAA receptor/pore complex is presumed to be a pentamer typically composed of a combination of alpha, beta, and gamma subunits, although the stoichiometry remains controversial. We probed the stoichiometry of the GABAA receptor by site-directed mutagenesis of a conserved leucine (to serine) in the putative second membrane-spanning domain of the rat alpha 1(alpha L263S), beta 2(alpha L259S), and gamma 2(alpha L274S) subunit isoforms. Coexpression of wild-type and mutant subunits of each class (e.g., alpha and alpha L263S), along with their wild-type counter-parts (e.g., beta and gamma), in Xenopus laevis oocytes resulted in mixed populations of receptors with distinct GABA sensitivities. This is consistent with the interpretation that the leucine mutation increased the GABA sensitivity in proportion to the number of incorporated mutant subunits. The apparent number of incorporated subunits for each class (alpha, beta, and gamma) could then be determined from the number of components comprising the compound GABA dose-response relationships. Using this approach, we conclude that the recombinant alpha 1 beta 2 gamma 2 GABAA receptor is a pentamer composed of two alpha subunits, two beta subunits, and one gamma subunit.