919 research outputs found
Nonpoint pollution of surface waters with phosphorus and nitrogen
Agriculture and urban activities are major sources of phosphorus and nitrogen to aquatic ecosystems. Atmospheric deposition further contributes as a source of N. These nonpoint inputs of nutrients are difficult to measure and regulate because they derive from activities dispersed over wide areas of land and are variable in time due to effects of weather. In aquatic ecosystems, these nutrients cause diverse problems such as toxic algal blooms, loss of oxygen, fish kills, loss of biodiversity (including species important for commerce and recreation), loss of aquatic plant beds and coral reefs, and other problems. Nutrient enrichment seriously degrades aquatic ecosystems and impairs the use of water for drinking, industry, agriculture, recreation, and other purposes.
Based on our review of the scientific literature, we are certain that (1) eutrophication is a widespread problem in rivers, lakes, estuaries, and coastal oceans, caused by overenrichment with P and N; (2) nonpoint pollution, a major source of P and N to surface waters of the United States, results primarily from agriculture and urban activity, including industry; (3) inputs of P and N to agriculture in the form of fertilizers exceed outputs in produce in the United States and many other nations; (4) nutrient flows to aquatic ecosystems are directly related to animal stocking densities, and under high livestock densities, manure production exceeds the needs of crops to which the manure is applied; (5) excess fertilization and manure production cause a P surplus to accumulate in soil, some of which is transported to aquatic ecosystems; and (6) excess fertilization and manure production on agricultural lands create surplus N, which is mobile in many soils and often leaches to downstream aquatic ecosystems, and which can also volatilize to the atmosphere, redepositing elsewhere and eventually reaching aquatic ecosystems.
If current practices continue, nonpoint pollution of surface waters is virtually certain to increase in the future. Such an outcome is not inevitable, however, because a number of technologies, land use practices, and conservation measures are capable of decreasing the flow of nonpoint P and N into surface waters.
From our review of the available scientific information, we are confident that: (1) nonpoint pollution of surface waters with P and N could be reduced by reducing surplus nutrient flows in agricultural systems and processes, reducing agricultural and urban runoff by diverse methods, and reducing N emissions from fossil fuel burning; and (2) eutrophication can be reversed by decreasing input rates of P and N to aquatic ecosystems, but rates of recovery are highly variable among water bodies. Often, the eutrophic state is persistent, and recovery is slow
Efficacy and safety of blonanserin transdermal patch in patients with schizophrenia: A 6-week randomized, double-blind, placebo-controlled, multicenter study
© 2019 The Authors Background: Blonanserin is a second-generation antipsychotic used for the treatment of schizophrenia. This study determined the efficacy, safety and pharmacokinetics of a blonanserin transdermal patch in patients with acutely exacerbated schizophrenia. Methods: This double-blind, multicenter, phase 3 study consisted of a 1-week observation period during which patients were treated with two patches of placebo, followed by a 6-week double-blind period where patients were randomized (1:1:1) to receive once-daily blonanserin 40 mg, blonanserin 80 mg, or placebo patches. The primary endpoint was the change from baseline in the total Positive and Negative Symptom Scale (PANSS) score. Safety assessments included treatment-emergent adverse events (TEAEs). Results: Between December 2014 and October 2018, patients were recruited and randomly assigned to blonanserin 40 mg (n = 196), blonanserin 80 mg (n = 194), or placebo (n = 190); of these, 77.2% completed the study. Compared with placebo, blonanserin significantly improved PANSS total scores at 6 weeks (least square mean [LSM] difference vs placebo: −5.6 with blonanserin 40 mg; 95% confidence interval [CI] −9.6, −1.6; adjusted p = 0.007, and − 10.4 with blonanserin 80 mg; 95% CI −14.4, −6.4; adjusted p \u3c 0.001). Blonanserin was well tolerated; the most common TEAEs reported were application-site erythema and pruritus, akathisia, tremor, and insomnia. Conclusions: Blonanserin transdermal patch improved the symptoms of acute schizophrenia with acceptable tolerability
Digital Trajectories to Care in First-Episode Psychosis.
OBJECTIVE::The emphasis on reducing the duration of untreated psychosis (DUP) has highlighted complex barriers to accessing appropriate services. Internet and social media use by individuals with first-episode psychosis (FEP) was examined to explore how these platforms might be used to facilitate treatment initiation. METHODS::Participants ages 15-35 were interviewed with the Pathways to Care for Psychosis Questionnaire, an 81-item instrument designed to explore online activity during symptom emergence. RESULTS::Of 112 participants, 90% used the Internet and social media daily. The Internet was listed as the most used resource (62%) for information while symptoms were emerging. A minority (19%) shared concerns via social media, and 76% responded favorably to the possibility of receiving online mental health support. CONCLUSIONS::The Internet and social media were part of daily life for participants with FEP. Activity continued throughout the DUP, offering the prospect of earlier intervention. Participants expressed positive attitudes toward Internet-based outreach and engagement efforts
Epigenetic patterns newly established after interspecific hybridization in natural populations of Solanum
Interspecific hybridization is known for triggering genetic and epigenetic changes, such as modifications on DNA methylation patterns and impact on phenotypic plasticity and ecological adaptation. Wild potatoes (Solanum, section Petota) are adapted to multiple habitats along the Andes, and natural hybridizations have proven to be a common feature among species of this group. Solanum × rechei, a recently formed hybrid that grows sympatrically with the parental species S. kurtzianum and S. microdontum, represents an ideal model for studying the ecologically and evolutionary importance of hybridization in generating of epigenetic variability. Genetic and epigenetic variability and their correlation with morphological variation were investigated in wild and ex situ conserved populations of these three wild potato species using amplified fragment length polymorphism (AFLP) and methylation‐sensitive amplified polymorphism (MSAP) techniques. We observed that novel methylation patterns doubled the number of novel genetic patterns in the hybrid and that the morphological variability measured on 30 characters had a higher correlation with the epigenetic than with the genetic variability. Statistical comparison of methylation levels suggested that the interspecific hybridization induces genome demethylation in the hybrids. A Bayesian analysis of the genetic data reveled the hybrid nature of S. × rechei, with genotypes displaying high levels of admixture with the parental species, while the epigenetic information assigned S. × rechei to its own cluster with low admixture. These findings suggested that after the hybridization event, a novel epigenetic pattern was rapidly established, which might influence the phenotypic plasticity and adaptation of the hybrid to new environments.EEA La ConsultaFil: Cara, Nicolás. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Mendoza. Instituto de Biologia Agricola de Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biologia Agricola de Mendoza; ArgentinaFil: Marfil, Carlos Federico. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Mendoza. Instituto de Biologia Agricola de Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biologia Agricola de Mendoza; ArgentinaFil: Masuelli, Ricardo Williams. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentin
Academic self-concept, gender and single-sex schooling
This paper assesses gender differences in academic self-concept for a cohort of children born in 1958 (the National Child Development Study). We address the question of whether attending single-sex or co-educational schools affected students’ perceptions of their own academic abilities (academic self-concept). Academic selfconcept was found to be highly gendered, even controlling for prior test scores. Boys had higher self-concepts in maths and science, and girls in English. Single-sex schooling reduced the gender gap in self-concept, while selective schooling was linked to lower academic self-concept overall
Stable characteristic evolution of generic 3-dimensional single-black-hole spacetimes
We report new results which establish that the accurate 3-dimensional
numerical simulation of generic single-black-hole spacetimes has been achieved
by characteristic evolution with unlimited long term stability. Our results
cover a selection of distorted, moving and spinning single black holes, with
evolution times up to 60,000M.Comment: 4 pages, 3 figure
Boosted three-dimensional black-hole evolutions with singularity excision
Binary black hole interactions provide potentially the strongest source of
gravitational radiation for detectors currently under development. We present
some results from the Binary Black Hole Grand Challenge Alliance three-
dimensional Cauchy evolution module. These constitute essential steps towards
modeling such interactions and predicting gravitational radiation waveforms. We
report on single black hole evolutions and the first successful demonstration
of a black hole moving freely through a three-dimensional computational grid
via a Cauchy evolution: a hole moving ~6M at 0.1c during a total evolution of
duration ~60M
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