North Carolina State University

About: North Carolina State University is a education organization based out in Raleigh, North Carolina, United States. It is known for research contribution in the topics: Population & Thin film. The organization has 44161 authors who have published 101744 publications receiving 3456774 citations. The organization is also known as: NCSU & North Carolina State University at Raleigh.

Psychiatric genome-wide association study analyses implicate neuronal, immune and histone pathways

Abstract: Genome-wide association studies (GWAS) of psychiatric disorders have identified multiple genetic associations with such disorders, but better methods are needed to derive the underlying biological mechanisms that these signals indicate. We sought to identify biological pathways in GWAS data from over 60,000 participants from the Psychiatric Genomics Consortium. We developed an analysis framework to rank pathways that requires only summary statistics. We combined this score across disorders to find common pathways across three adult psychiatric disorders: schizophrenia, major depression and bipolar disorder. Histone methylation processes showed the strongest association, and we also found statistically significant evidence for associations with multiple immune and neuronal signaling pathways and with the postsynaptic density. Our study indicates that risk variants for psychiatric disorders aggregate in particular biological pathways and that these pathways are frequently shared between disorders. Our results confirm known mechanisms and suggest several novel insights into the etiology of psychiatric disorders.

The Contribution of Commercial Fertilizer Nutrients to Food Production

Abstract: technology and intensified production often involve a greater need for commercial fertilizer nutrients to avoid Nutrient inputs in crop production systems have come under innutrient depletion and ensure soil quality and crop procreased scrutiny in recent years because of the potential for environductivity. The need for increased inputs correctly raises mental impact from inputs such as N and P. The benefits of nutrient inputsareoftenminimizedindiscussionsofpotentialrisk.Thepurpose questions about associated risks. Potential risks are ofof this article is to examine existing data and approximate the effects ten widely publicized while the associated benefits of of nutrient inputs, specifically from commercial fertilizers, on crop an abundant, affordable, and healthful food supply can yield. Several long-term studies in the USA, England, and the tropics, be overlooked or understated. To judge any such pracalong with the results from an agricultural chemical use study and ticeorsystem,therisksmustbeevaluatedincomparison nutrient budget information, were evaluated. A total of 362 seasons with the benefits. While misuses of agricultural fertilizof crop production were included in the long-term study evaluations. ers have undoubtedly occurred and concerns about how Crops utilized in these studies included corn (Zea mays L.), wheat fertilizers affect the environment have sometimes been (Triticum aestivum L.), soybean [Glycine max (L.) Merr.], rice (Oroverstated, the purpose of this article is not to address yza sativa L.), and cowpea [Vigna unguiculata (L.) Walp.]. The these issues but to provide evidence of the impact comaverage percentage of yield attributable to fertilizer generally ranged from about 40 to 60% in the USA and England and tended to be mercial fertilizers have had on agricultural production. much higher in the tropics. Recently calculated budgets for N, P, and Several attempts have previously been made to estiKindicatethatcommercialfertilizer makesupthemajorityofnutrient mate how much of the crop production in the USA is inputs necessary to sustain current crop yields in the USA. The results attributable to commercial nutrient inputs. These estiof this investigation indicate that the commonly cited generalization mates usually range from about 30 to 50% for major that at least 30 to 50% of crop yield is attributable to commercial grain crops (Nelson, 1990). Determining these estimates fertilizer nutrient inputs is a reasonable, if not conservative estimate. presents significant challenges, and assumptions are always required regardless of the approach taken. One difficulty that arises is that crops respond differently to M

Ecological thresholds at the savanna-forest boundary: how plant traits, resources and fire govern the distribution of tropical biomes

Abstract: Fire shapes the distribution of savanna and forest through complex interactions involving climate, resources and species traits. Based on data from central Brazil, we propose that these interactions are governed by two critical thresholds. The fire-resistance threshold is reached when individual trees have accumulated sufficient bark to avoid stem death, whereas the fire-suppression threshold is reached when an ecosystem has sufficient canopy cover to suppress fire by excluding grasses. Surpassing either threshold is dependent upon long fire-free intervals, which are rare in mesic savanna. On high-resource sites, the thresholds are reached quickly, increasing the probability that savanna switches to forest, whereas low-resource sites are likely to remain as savanna even if fire is infrequent. Species traits influence both thresholds; saplings of savanna trees accumulate bark thickness more quickly than forest trees, and are more likely to become fire resistant during fire-free intervals. Forest trees accumulate leaf area more rapidly than savanna trees, thereby accelerating the transition to forest. Thus, multiple factors interact with fire to determine the distribution of savanna and forest by influencing the time needed to reach these thresholds. Future work should decipher multiple environmental controls over the rates of tree growth and canopy closure in savanna.