Resource limitations to nitric oxide emissions from a sagebrush-steppe ecosystem

We monitored soil emissions of NO, NO₂, N₂O, and CO₂ throughout the summer dry season at a remote North American sagebrush-steppe ecosystem following application of several resources, including water, NH ₄ ⁺ , NO ₃ ^– and sucrose. Despite low levels of soil NH ₄ ^– (5.60±0.95 mg NH ₄ ^– -N per kg soil, mean ± S.E.), and NO ₃ ^– -N (1.34±0.20 mg NO ₃ ^– -N per kg soil), NO emissions ranged from about 0.2 to 2.8 ng NO-N m^–2 s^–1, comparable to rates measured from many agricultural, tropical, and other undisturbed ecosystems. Soil wetting increased NO emissions as much as 400-fold when initial gravimetric soil moisture contents were less than about 50 mg kg _soil ^–1 and soil temperature was greater than or equal to 20 °C. Wetting treatments with 20 mg NH ₄ ⁺ -N kg _soil ^–1 raised NO emission rates to a level that was nearly an order of magnitude higher than that observed after water addition alone. Wetting treatments with 20 mg NO ₃ ^– -N kg _soil ^–1 , 240 mg sucrose-C kg _soil ^–1 , or NO ₃ ^– plus sucrose had no statistically significant effect upon NO emissions. Soil denitrifying enzyme activity was low at this site, and N₂O emissions in the field were below detection limits. Soil nitrifying enzyme activity was extremely high at this site, indicating that the NH ₄ ⁺ released by ammonification would be consumed at least once every 1.7 days. These observations indicate that NO emissions from this undisturbed ecosystem were likely a consequence of high nitrification activity, and that sagebrush-steppe ecosystems may be a more important NO source than has been previously assumed.     

Conserved fMRI and LFP signals during new associative learning in the human and macaque monkey medial temporal lobe

We measured local field potential (LFP) and blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) in the medial temporal lobes of monkeys and humans, respectively, as they performed the same conditional motor associative learning task. Parallel analyses were used to examine both data sets. Despite significantly faster learning in humans relative to monkeys, we found equivalent neural signals differentiating new versus highly familiar stimuli, first stimulus presentation, trial outcome, and learning strength in the entorhinal cortex and hippocampus of both species. Thus, the use of parallel behavioral tasks and analyses in monkeys and humans revealed conserved patterns of neural activity across the medial temporal lobe during an associative learning task.     

Sensitive and Specific Immunohistochemical Diagnosis of Human Alveolar Echinococcosis with the Monoclonal Antibody Em2G11

Background

Alveolar echinococcosis (AE) is caused by the metacestode stage of Echinococcus multilocularis. Differential diagnosis with cystic echinococcosis (CE) caused by E. granulosus and AE is challenging. We aimed at improving diagnosis of AE on paraffin sections of infected human tissue by immunohistochemical testing of a specific antibody.

Methodology/Principal Findings

We have analysed 96 paraffin archived specimens, including 6 cutting needle biopsies and 3 fine needle aspirates, from patients with suspected AE or CE with the monoclonal antibody (mAb) Em2G11 specific for the Em2 antigen of E. multilocularis metacestodes. In human tissue, staining with mAb Em2G11 is highly specific for E. multilocularis metacestodes while no staining is detected in CE lesions. In addition, the antibody detects small particles of E. multilocularis (spems) of less than 1 µm outside the main lesion in necrotic tissue, liver sinusoids and lymphatic tissue most probably caused by shedding of parasitic material. The conventional histological diagnosis based on haematoxylin and eosin and PAS stainings were in accordance with the immunohistological diagnosis using mAb Em2G11 in 90 of 96 samples. In 6 samples conventional subtype diagnosis of echinococcosis had to be adjusted when revised by immunohistology with mAb Em2G11.

Conclusions/Significance

Immunohistochemistry with the mAb Em2G11 is a new, highly specific and sensitive diagnostic tool for AE. The staining of small particles of E. multilocularis (spems) outside the main lesion including immunocompetent tissue, such as lymph nodes, suggests a systemic effect on the host.     

Analysis of the biosynthetic gene cluster for the polyether antibiotic monensin in Streptomyces cinnamonensis and evidence for the role of monB and monC genes in oxidative cyclization

The analysis of a candidate biosynthetic gene cluster (97 kbp) for the polyether ionophore monensin from Streptomyces cinnamonensis has revealed a modular polyketide synthase composed of eight separate multienzyme subunits housing a total of 12 extension modules, and flanked by numerous other genes for which a plausible function in monensin biosynthesis can be ascribed. Deletion of essentially all these clustered genes specifically abolished monensin production, while overexpression in S. cinnamonensis of the putative pathway-specific regulatory gene monR led to a fivefold increase in monensin production. Experimental support is presented for a recently-proposed mechanism, for oxidative cyclization of a linear polyketide intermediate, involving four enzymes, the products of monBI, monBII, monCI and monCII. In frame deletion of either of the individual genes monCII (encoding a putative cyclase) or monBII (encoding a putative novel isomerase) specifically abolished monensin production. Also, heterologous expression of monCI, encoding a flavin-linked epoxidase, in S. coelicolor was shown to significantly increase the ability of S. coelicolor to epoxidize linalool, a model substrate for the presumed linear polyketide intermediate in monensin biosynthesis.     

Mapping of Schistosomiasis and Soil-Transmitted Helminths in Namibia: The First Large-Scale Protocol to Formally Include Rapid Diagnostic Tests

Background

Namibia is now ready to begin mass drug administration of praziquantel and albendazole against schistosomiasis and soil-transmitted helminths, respectively. Although historical data identifies areas of transmission of these neglected tropical diseases (NTDs), there is a need to update epidemiological data. For this reason, Namibia adopted a new protocol for mapping of schistosomiasis and geohelminths, formally integrating rapid diagnostic tests (RDTs) for infections and morbidity. In this article, we explain the protocol in detail, and introduce the concept of ‘mapping resolution’, as well as present results and treatment recommendations for northern Namibia.

Methods/Findings/Interpretation

This new protocol allowed a large sample to be surveyed (N = 17 896 children from 299 schools) at relatively low cost (7 USD per person mapped) and very quickly (28 working days). All children were analysed by RDTs, but only a sub-sample was also diagnosed by light microscopy. Overall prevalence of schistosomiasis in the surveyed areas was 9.0%, highly associated with poorer access to potable water (OR = 1.5, P<0.001) and defective (OR = 1.2, P<0.001) or absent sanitation infrastructure (OR = 2.0, P<0.001). Overall prevalence of geohelminths, more particularly hookworm infection, was 12.2%, highly associated with presence of faecal occult blood (OR = 1.9, P<0.001). Prevalence maps were produced and hot spots identified to better guide the national programme in drug administration, as well as targeted improvements in water, sanitation and hygiene. The RDTs employed (circulating cathodic antigen and microhaematuria for Schistosoma mansoni and S. haematobium, respectively) performed well, with sensitivities above 80% and specificities above 95%.

Conclusion/Significance

This protocol is cost-effective and sensitive to budget limitations and the potential economic and logistical strains placed on the national Ministries of Health. Here we present a high resolution map of disease prevalence levels, and treatment regimens are recommended.     

Cholecystokinin (CCK)-induced desensitization of pancreatic enzyme secretion is mediated by low affinity CCK receptors

CCK-8-induced desensitization of carbachol-stimulated amylase secretion occurred over a range of concentrations of CCK-8 that occupy low affinity CCK receptors. CCK-JMV-180 [BOC-Tyr(SO3)-Nle-Gly-Trp-Nle-Asp-2-phenylethylester] at concentrations up to 1 microM did not cause desensitization of enzyme secretion; however, the peptide was able to inhibit CCK-8-induced desensitization. Analysis of the relationship between receptor occupation and CCK-8-induced desensitization caused by CCK-8 and CCK-JMV-180 in combination also indicated that CCK-8-induced desensitization of carbachol-stimulated amylase secretion is caused by occupation of low affinity CCK receptors.     

Moth Outbreaks Reduce Decomposition in Subarctic Forest Soils

Ecosystems - Tree mortality from insect infestations can significantly reduce carbon storage in forest soils. In subarctic birch forests (Betula pubescens), ecosystem C cycling is largely affected...     

Gender-equitable caregiver attitudes and education and safety of adolescent girls in South Kivu,DRC: A secondary analysis from a randomized controlled trial

BackgroundAdolescent girls face myriad threats to their well-being and safety as a result of gender-inequitable attitudes and norms, and these risks are often exacerbated during humanitarian emergencies. While humanitarian actors have begun to address caregivers’ behaviors and gender attitudes as an approach to support and meet the needs of adolescent girls, best practices for working with caregivers to improve adolescent girls’ well-being in these settings have yet to be identified.Methods and findingsThis study uses panel data from a program evaluation to analyze associations between changes in gender-equitable attitudes among caregivers and changes in schooling and violence victimization for girls ages 10 to 14 years old in the Democratic Republic of the Congo (DRC). Participants were recruited in May 2015 for baseline (May to July 2015) and endline (August to October 2016) data collection. Baseline and endline data for both caregivers and girls were available for 732 girls. The average ages of adolescents and caregivers were 12 and 40.7, respectively, and 92% of caregivers were female. The predictor of interest was the change in caregivers’ gender-equitable attitudes between the 2 points in time, where attitudes were measured using 10 underlying survey questions. The primary outcomes of interest were dichotomous and included improvement in schooling participation and declines in physical, sexual, and emotional violence and feeling uncared for. Logistic regression was used to estimate the association between changes in caregivers’ attitudes and 5 outcomes of interest and revealed that an increase in a caregiver’s gender-equitable attitude score was associated with significantly greater odds of a girl experiencing an improvement in schooling participation (aOR = 1.08, CI [1.005, 1.154], p = 0.036) and of a girl experiencing a marginal decline in physical violence victimization (aOR = 1.07, CI [0.989, 1.158], p = 0.092). Analyses also revealed that older girls had lower odds of experiencing an improvement in schooling participation (aOR = 0.77, CI [0.686, 0.861], p < 0.001), physical violence (aOR = 0.86, CI [0.757, 0.984], p = 0.028), sexual violence (aOR = 0.86, CI [0.743, 1.003], p = 0.055), or emotional violence (aOR = 0.98, CI [0.849, 1.105], p = 0.005). Important limitations in this study include the self-reported nature of outcomes, use of single questionnaire items to construct the outcome variables, and potential self-selection bias.ConclusionsResults suggest that supporting caregivers to increase gender equitable attitudes may be associated with benefits in dual outcomes of education and safety for adolescent girls in eastern DRC. Further research is needed to better understand how to induce a shift in these attitudes in multisectoral programming.Trial registration{"type":"clinical-trial","attrs":{"text":"NCT02384642","term_id":"NCT02384642"}}NCT02384642.

In an additional analysis of COMPASS intervention trial findings, Ilana Seff and colleagues study the associations between changes in gender attitudes among caregivers and violence victimization and schooling of adolescent girls in South Kivu, Democratic Republic of Congo.