2,379 research outputs found
Quantifying water quality improvements through use of precision herbicide application technologies in a dry-tropical, furrow-irrigated cropping system
This study compared water quality effects of using precision herbicide application technologies and traditional spraying approaches across several regulated 'priority' and alternative preand post-emergent herbicides in a northern Australian cane farming system. Use of herbicide banding spray technologies resulted in pre-emergent herbicide load reductions, extending substantially beyond simple proportionate decreases in the amount of herbicide ingredient applied to paddocks. Aquatic risk assessment from resultant chemical mixtures leaving paddocks, and upscaled to local catchment concentrations, highlighted that precision application technologies could markedly reduce the ecological risk of pre-emergent herbicides. These risk reductions were, however, often complicated by the additional toxicity of post-emergent herbicides in mixtures, some associated with the adoption of band-spraying weed treatments. While the currently regulated priority herbicide, diuron, posed the greatest risk to the environment, alternative herbicides could still pose significant environmental risks, although these relative risks were lower at more ecologically relevant concentrations, typically found in the local freshwater ecosystems. Results underline the need for a carefully considered approach to integrating alternative herbicides and precision application technologies into improved weed management by irrigating cane farmers. Recent government changes to the appraisal of water quality improvement progress, from load-based to ecosystem-based targets, involving a much broader suite of herbicides, also appear likely to complicate assessment of the environmental impacts of practice change adoption for the industry
Vertical Distribution of Planktic Foraminifera through an Oxygen Minimum Zone: How Assemblages and Shell Morphology Reflect Oxygen Concentrations
Oxygen-depleted regions of the global ocean are rapidly expanding, with important implications for global biogeochemical cycles. However, our ability to make projections of a future deoxygenated ocean is limited by a lack of empirical data with which to test and constrain the behavior of global climatic and oceanographic models. We use depth-stratified plankton tows to demonstrate that some species of planktic foraminifera are adapted to life in the heart of the pelagic Oxygen Minimum Zone (OMZ). In particular, we identify two species, Globorotaloides hexagonus and Hastigerina parapelagica, living within the Eastern Tropical North Pacific OMZ. The shells of the former are preserved in marine sediments and could be used to trace the extent and intensity of low-oxygen pelagic habitats in the fossil record. Additional morphometric analyses of G. hexagonus show that shells found in the lowest oxygen environments are larger, more porous, less dense, and have more chambers in the final whorl. The association of this species with the OMZ and the apparent plasticity of its shell in response to ambient oxygenation invites the use of G. hexagonus shells in sediment cores as potential proxies for both the presence and intensity of overlying OMZs
Secondary structural characterization of oligonucleotide strands using electrospray ionization mass spectrometry
Differences in charge state distributions of hairpin versus linear strands of oligonucleotides are analyzed using electrospray ionization mass spectrometry (ESI-MS) in the negative ion detection mode. It is observed that the linear structures show lower charge state distribution than the hairpin strands of the same composition. The concentration of ammonium acetate and the cone voltage are major factors that cause the shift of the negative ions in the charge states. The ESI data presented here are supported by UV spectra of strands acquired at 260 nm wavelength in aqueous ammonium acetate solution. We will show that the strands that demonstrate a higher charge state distribution in the gas phase also have a higher melting temperature in solution
Localized Translation of gurken/TGF-α mRNA during Axis Specification Is Controlled by Access to Orb/CPEB on Processing Bodies.
In Drosophila oocytes, gurken/TGF-α mRNA is essential for establishing the future embryonic axes. gurken remains translationally silent during transport from its point of synthesis in nurse cells to its final destination in the oocyte, where it associates with the edge of processing bodies. Here we show that, in nurse cells, gurken is kept translationally silent by the lack of sufficient Orb/CPEB, its translational activator. Processing bodies in nurse cells have a similar protein complement and ultrastructure to those in the oocyte, but they markedly less Orb and do not associate with gurken mRNA. Ectopic expression of Orb in nurse cells at levels similar to the wild-type oocyte dorso-anterior corner at mid-oogenesis is sufficient to cause gurken mRNA to associate with processing bodies and translate prematurely. We propose that controlling the spatial distribution of translational activators is a fundamental mechanism for regulating localized translation.This work was supported by a studentship from the Wellcome Trust (grant 097304 to A.D.), a Wellcome Trust Senior Research Fellowship (grant 096144 to I.D and supporting R.M.P), the University of Cambridge, ISSF (grant 097814 to T.T.W), and Wellcome Trust Strategic Awards 091911 and 107457 supporting advanced microscopy at Micron Oxford (http://micronoxford.com).This is the author accepted manuscript. The final version is available from Cell Press via http://dx.doi.org/10.1016/j.celrep.2016.02.03
Evidence against pain specificity in the dorsal posterior insula
The search for a pain centre in the brain has long eluded neuroscientists. Although many regions of the brain have been shown to respond to painful stimuli, all of these regions also respond to other types of salient stimuli. In a recent paper, Segerdahl et al. (Nature Neuroscience, 2015) claims that the dorsal posterior insula (dpIns) is a pain-specific region based on the observation that the magnitude of regional cerebral blood flow (rCBF) fluctuations in the dpIns correlated with the magnitude of evoked pain. However, such a conclusion is, simply, not justified by the experimental evidence provided. Here we discuss three major factors that seriously question this claim
Site-selection model for optimal transplantation of eelgrass Zostera marina in the northeastern US
A site-selection model for eelgrass Zostera marina L. ecosystem restoration was developed in the northeastern US to select optimal areas for transplanting eelgrass. The site-selection model synthesizes available historic and literature-based information, reference data, and simple field measurements to identify and prioritize locations for large-scale eelgrass transplantation. Model development was based on the physical and biological characteristics associated with the most successful transplant sites in a mitigation project for the New Hampshire Port Authority. The site-selection process is divided into 3 phases: (1) the first phase uses available environmental information to formulate a preliminary transplant suitability index (PTSI) for pre-screening and eliminating unsuitable sites; (2) the second phase involves field measurements of light availability and bioturbation as well as survival and growth of test transplants at priority sites identified by the PTSI; (3) a transplant suitability index (TSI) score is calculated for each site based on the PTSI and the results of field assessments. The TSI is a multiplicative index that eliminates sites which receive ratings of zero and gives high scores to those sites with the greatest potential for successful transplantation. We applied the TSI post hoc to the New Hampshire Port Project¹s eelgrass transplant sites, and subsequently the site-selection model was used in an eelgrass restoration project in New Bedford Harbor, Massachusetts. After 2 yr of transplanting, the New Bedford Harbor effort has resulted in success at 62% of the sites planted using the site-selection model
Evaluation of naturalistic driving behavior using in-vehicle monitoring technology in preclinical and early Alzheimer\u27s disease
Cognitive impairment is a significant risk factor for hazardous driving among older drivers with Alzheimer\u27s dementia, but little is known about how the driving behavior of mildly symptomatic compares with those in the preclinical, asymptomatic phase of Alzheimer\u27s disease (AD). This study utilized two in-car technologies to characterize driving behavior in symptomatic and preclinical AD. The goals of this pilot study were to (1) describe unsafe driving behaviors in individuals with symptomatic early AD using G-force triggered video capture and (2) compare the driving habits of these symptomatic AD drivers to two groups of cognitively normal drivers, those with and those without evidence of cerebral amyloidosis (CN/A+ and CN/A-) using a global positioning system (GPS) datalogger. Thirty-three drivers (aged 60+ years) were studied over 3 months. G-force triggered video events captured instances of near-misses/collisions, traffic violations, risky driver conduct, and driving fundamentals. GPS data were sampled every 30 s and all instances of speeding, hard braking, and sudden acceleration were recorded. For the early AD participants, video capture identified driving unbelted, late response, driving too fast for conditions, traffic violations, poor judgment, and not scanning intersections as the most frequently occurring safety errors. When evaluating driving using the GPS datalogger, hard breaking events occurred most frequently on a per trip basis across all three groups. The CN/A+ group had the lowest event rate across all three event types with lower instances of speeding. Slower psychomotor speed (Trail Making Part A) was associated with fewer speeding events, more hard acceleration events, and more overall events. GPS tracked instances of speeding were correlated with total number of video-captured near-collisions/collisions and driving fundamentals. Results demonstrate the utility of electronic monitoring to identify potentially unsafe driving events in symptomatic and preclinical AD. Results suggest that drivers with preclinical AD may compensate for early, subtle cognitive changes by driving more slowly and cautiously than healthy older drivers or those with cognitive impairment. Self-regulatory changes in driving behavior appear to occur in the preclinical phase of AD, but safety concerns may not arise until symptoms of cognitive impairment emerge and the ability to self-monitor declines
Micronutrient Dietary Intake in Latina Pregnant Adolescents and Its Association with Level of Depression, Stress, and Social Support
Adolescent pregnant women are at greater risk for nutritional deficits, stress, and depression than their adult counterparts, and these risk factors for adverse pregnancy outcomes are likely interrelated. This study evaluated the prevalence of nutritional deficits in pregnant teenagers and assessed the associations among micronutrient dietary intake, stress, and depression. One hundred and eight pregnant Latina adolescents completed an Automated Self-Administered 24-hour dietary recall (ASA24) in the 2nd trimester. Stress was measured using the Perceived Stress Scale and the Prenatal Distress Questionnaire. Depressive symptoms were evaluated with the Reynolds Adolescent Depression Scale. Social support satisfaction was measured using the Social Support Questionnaire. More than 50% of pregnant teenagers had an inadequate intake (excluding dietary supplement) of folate, vitamin A, vitamin E, iron, zinc, calcium, magnesium, and phosphorous. Additionally, >20% of participants had an inadequate intake of thiamin, riboflavin, niacin, vitamin B6, vitamin B12, vitamin C, copper, and selenium. Prenatal supplement inclusion improved dietary intake for most micronutrients except for calcium, magnesium, and phosphorous, (>50% below the Estimated Average Requirement (EAR)) and for copper and selenium (>20% below the EAR). Higher depressive symptoms were associated with higher energy, carbohydrates, and fats, and lower magnesium intake. Higher social support satisfaction was positively associated with dietary intake of thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, vitamin C, vitamin E, iron, and zinc. The findings suggest that mood and dietary factors are associated and should be considered together for health interventions during adolescent pregnancy for the young woman and her future child
A single and rapid calcium wave at egg activation in Drosophila.
Activation is an essential process that accompanies fertilisation in all animals and heralds major cellular changes, most notably, resumption of the cell cycle. While activation involves wave-like oscillations in intracellular Ca(2+) concentration in mammals, ascidians and polychaete worms and a single Ca(2+) peak in fish and frogs, in insects, such as Drosophila, to date, it has not been shown what changes in intracellular Ca(2+) levels occur. Here, we utilise ratiometric imaging of Ca(2+) indicator dyes and genetically encoded Ca(2+) indicator proteins to identify and characterise a single, rapid, transient wave of Ca(2+) in the Drosophila egg at activation. Using genetic tools, physical manipulation and pharmacological treatments we demonstrate that the propagation of the Ca(2+) wave requires an intact actin cytoskeleton and an increase in intracellular Ca(2+) can be uncoupled from egg swelling, but not from progression of the cell cycle. We further show that mechanical pressure alone is not sufficient to initiate a Ca(2+) wave. We also find that processing bodies, sites of mRNA decay and translational regulation, become dispersed following the Ca(2+) transient. Based on this data we propose the following model for egg activation in Drosophila: exposure to lateral oviduct fluid initiates an increase in intracellular Ca(2+) at the egg posterior via osmotic swelling, possibly through mechano-sensitive Ca(2+) channels; a single Ca(2+) wave then propagates in an actin dependent manner; this Ca(2+) wave co-ordinates key developmental events including resumption of the cell cycle and initiation of translation of mRNAs such as bicoid.This work was supported by the University of Cambridge, ISSF to T.T.W. [grant number 097814]; and Wellcome Trust Senior Research Fellowship to I.D. [grant number 096144].This is the final version of the article. It first appeared from the Company of Biologists via http://dx.doi.org/10.1242/bio.20141129
An Evaluation of MacArthur's Window of Opportunity: Preserving Affordable Rental Housing Initiative
In this report, we describe the seven strategies by which the MacArthur Foundation sought ambitious changes in the preservation of affordable rental housing. In brief, these strategies were to* support a cadre of large nonprofit owners of affordable rental housing to both preserve rental housing and act as spokespersons for preservation* increase capital for preservation by investing in special-purpose vehicles, such as preservation-themed loan funds* invest in regional interagency partnerships to retain affordable rental housing* develop business practices, tools, and research for or about preservation* provide loans and grants directly to state and local government agencies that themselves fund preservation transactions* promote low-income tenants' rights to remain in and advocate for affordable rental housing* improve the funding, regulatory, and legislative context for preservation through the foundation's combined investments in nonprofit owners, networks of nonprofit owners, special-purpose vehicles, state and local government agencies, and advocates
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