Locating farmer-based knowledge and vested interests in natural resource management: the interface of ethnopedology, land tenure and gender in soil erosion management in the Manupali watershed, Philippines

This paper examines local soil knowledge and management in the Manupali watershed in the Philippines

Necessity of Hippocampal Neurogenesis for the Therapeutic Action of Antidepressants in Adult Nonhuman Primates

Rodent studies show that neurogenesis is necessary for mediating the salutary effects of antidepressants. Nonhuman primate (NHP) studies may bridge important rodent findings to the clinical realm since NHP-depression shares significant homology with human depression and kinetics of primate neurogenesis differ from those in rodents. After demonstrating that antidepressants can stimulate neurogenesis in NHPs, our present study examines whether neurogenesis is required for antidepressant efficacy in NHPs. MATERIALS/METHODOLOGY: Adult female bonnets were randomized to three social pens (N = 6 each). Pen-1 subjects were exposed to control-conditions for 15 weeks with half receiving the antidepressant fluoxetine and the rest receiving saline-placebo. Pen-2 subjects were exposed to 15 weeks of separation-stress with half receiving fluoxetine and half receiving placebo. Pen-3 subjects 2 weeks of irradiation (N = 4) or sham-irradiation (N = 2) and then exposed to 15 weeks of stress and fluoxetine. Dependent measures were weekly behavioral observations and postmortem neurogenesis levels.Exposing NHPs to repeated separation stress resulted in depression-like behaviors (anhedonia and subordinance) accompanied by reduced hippocampal neurogenesis. Treatment with fluoxetine stimulated neurogenesis and prevented the emergence of depression-like behaviors. Ablation of neurogenesis with irradiation abolished the therapeutic effects of fluoxetine. Non-stressed controls had normative behaviors although the fluoxetine-treated controls had higher neurogenesis rates. Across all groups, depression-like behaviors were associated with decreased rates of neurogenesis but this inverse correlation was only significant for new neurons in the anterior dentate gyrus that were at the threshold of completing maturation.We provide evidence that induction of neurogenesis is integral to the therapeutic effects of fluoxetine in NHPs. Given the similarity between monkeys and humans, hippocampal neurogenesis likely plays a similar role in the treatment of clinical depression. Future studies will examine several outstanding questions such as whether neuro-suppression is sufficient for producing depression and whether therapeutic neuroplastic effects of fluoxetine are specific to antidepressants

Assessing the Microbial Community and Functional Genes in a Vertical Soil Profile with Long-Term Arsenic Contamination

Conceived and designed the experiments: GW. Performed the experiments: JX GL. Analyzed the data: JX JZ GW. Contributed reagents/materials/analysis tools: ST JZ GW. Wrote the paper: JX ZH JDVN JZ GW.Arsenic (As) contamination in soil and groundwater has become a serious problem to public health. To examine how microbial communities and functional genes respond to long-term arsenic contamination in vertical soil profile, soil samples were collected from the surface to the depth of 4 m (with an interval of 1 m) after 16-year arsenic downward infiltration. Integrating BioLog and functional gene microarray (GeoChip 3.0) technologies, we showed that microbial metabolic potential and diversity substantially decreased, and community structure was markedly distinct along the depth. Variations in microbial community functional genes, including genes responsible for As resistance, carbon and nitrogen cycling, phosphorus utilization and cytochrome c oxidases were detected. In particular, changes in community structures and activities were correlated with the biogeochemical features along the vertical soil profile when using the rbcL and nifH genes as biomarkers, evident for a gradual transition from aerobic to anaerobic lifestyles. The C/N showed marginally significant correlations with arsenic resistance (p = 0.069) and carbon cycling genes (p = 0.073), and significant correlation with nitrogen fixation genes (p = 0.024). The combination of C/N, NO3− and P showed the highest correlation (r = 0.779, p = 0.062) with the microbial community structure. Contradict to our hypotheses, a long-term arsenic downward infiltration was not the primary factor, while the spatial isolation and nutrient availability were the key forces in shaping the community structure. This study provides new insights about the heterogeneity of microbial community metabolic potential and future biodiversity preservation for arsenic bioremediation management.Yeshttp://www.plosone.org/static/editorial#pee

Adipose Tissue Density, a Novel Biomarker Predicting Mortality Risk in Older Adults

BACKGROUND. Knowledge of adipose composition in relation to mortality may help delineate inconsistent relationships between obesity and mortality in old age. We evaluated relationships between abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) density, mortality, biomarkers, and characteristics. METHODS. VAT and SAT density were determined from computed tomography scans in persons aged 65 and older, Health ABC (n = 2,735) and AGES-Reykjavik (n = 5,131), and 24 nonhuman primates (NHPs). Associations between adipose density and mortality (4–13 years follow-up) were assessed with Cox proportional hazards models. In NHPs, adipose density was related to serum markers and tissue characteristics. RESULTS. Higher density adipose tissue was associated with mortality in both studies with adjustment for risk factors including adipose area, total fat, and body mass index. In women, hazard ratio and 95% CI for the densest quintile (Q5) versus least dense (Q1) for VAT density were 1.95 (1.36–2.80; Health ABC) and 1.88 (1.31–2.69; AGES-Reykjavik) and for SAT density, 1.76 (1.35–2.28; Health ABC) and 1.56 (1.15–2.11; AGES-Reykjavik). In men, VAT density was associated with mortality in Health ABC, 1.52 (1.12–2.08), whereas SAT density was associated with mortality in both Health ABC, 1.58 (1.21–2.07), and AGES-Reykjavik, 1.43 (1.07–1.91). Higher density adipose tissue was associated with smaller adipocytes in NHPs. There were no consistent associations with inflammation in any group. Higher density adipose tissue was associated with lower serum leptin in Health ABC and NHPs, lower leptin mRNA expression in NHPs, and higher serum adiponectin in Health ABC and NHPs. CONCLUSION. VAT and SAT density provide a unique marker of mortality risk that does not appear to be inflammation related