2,576 research outputs found
Pheromone mating disruption: novel, non-toxic control of the European corn borer
The European corn borer is one of the most damaging insects in Iowa cornfields, causing more than $100 million in crop losses each year. In this project, the sex attractant pheromone of the European corn borer was used to obstruct the ability of the adult male moths to locate females for mating. In the first year, efforts focused on mating disruption in a small area, while in the second year dispensers were deployed on a larger scale and evaluated for efficacy
Estimating oil concentration and flow rate with calibrated vessel-mounted acoustic echo sounders
As part of a larger program aimed at evaluating acoustic techniques for mapping the distribution of subsurface oil and gas associated with the Deepwater Horizon-Macondo oil spill, observations were made on June 24 and 25, 2010 using vessel-mounted calibrated single-beam echo sounders on the National Oceanic and Atmospheric Administration ship Thomas Jefferson. Coincident with visual observations of oil at the sea surface, the 200-kHz echo sounder showed anomalously high-volume scattering strength in the upper 200 m on the western side of the wellhead, more than 100 times higher than the surrounding waters at 1,800-m distance from the wellhead, and weakening with increasing distance out to 5,000 m. Similar high-volume scattering anomalies were not observed at 12 or 38 kHz, although observations of anomalously low-volume scattering strength were made in the deep scattering layer at these frequencies at approximately the same locations. Together with observations of ocean currents, the acoustic observations are consistent with a rising plume of small (\u3c 1-mm radius) oil droplets. Using simplistic but reasonable assumptions about the properties of the oil droplets, an estimate of the flow rate was made that is remarkably consistent with those made at the wellhead by other means. The uncertainty in this acoustically derived estimate is high due to lack of knowledge of the size distribution and rise speed of the oil droplets. If properly constrained, these types of acoustic measurements can be used to rapidly estimate the flow rate of oil reaching the surface over large temporal and spatial scales
Influence network linkages across implementation strategy conditions in a randomized controlled trial of two strategies for scaling up evidence-based practices in public youth-serving systems.
BackgroundGiven the importance of influence networks in the implementation of evidence-based practices and interventions, it is unclear whether such networks continue to operate as sources of information and advice when they are segmented and disrupted by randomization to different implementation strategy conditions. The present study examines the linkages across implementation strategy conditions of social influence networks of leaders of youth-serving systems in 12 California counties participating in a randomized controlled trial of community development teams (CDTs) to scale up use of an evidence-based practice.MethodsSemi-structured interviews were conducted with 38 directors, assistant directors, and program managers of county probation, mental health, and child welfare departments. A web-based survey collected additional quantitative data on information and advice networks of study participants. A mixed-methods approach to data analysis was used to create a sociometric data set (n = 176) to examine linkages between treatment and standard conditions.ResultsOf those network members who were affiliated with a county (n = 137), only 6 (4.4%) were directly connected to a member of the opposite implementation strategy condition; 19 (13.9%) were connected by two steps or fewer to a member of the opposite implementation strategy condition; 64 (46.7%) were connected by three or fewer steps to a member of the opposite implementation strategy condition. Most of the indirect steps between individuals who were in different implementation strategy conditions were connections involving a third non-county organizational entity that had an important role in the trial in keeping the implementation strategy conditions separate. When these entities were excluded, the CDT network exhibited fewer components and significantly higher betweenness centralization than did the standard condition network.ConclusionAlthough the integrity of the RCT in this instance was not compromised by study participant influence networks, RCT designs should consider how influence networks may extend beyond boundaries established by the randomization process in implementation studies.Trial registrationNCT00880126
Methods for Collecting and Using Backscatter Field Calibration Information for the Reson 7000 Series Multibeams
In support of Integrated Ocean and Coastal Mapping, the National Oceanic and Atmospheric Administration’s (NOAA) Office of Coast Survey collects meaningful acoustic backscatter as a ancillary product of its navigational charting mission. Many of NOAA’s field units have Reson 7000 series multibeam echosounders which have been shown to have decidedly non-linear response characteristics under certain high signal conditions. This non-linear behavior significantly increases the complexity of the radiometric corrections required to make use of backscatter under a variety of processing paradigms. Avoiding operating these systems in the non-linear operational domain is a simpler approach. However, the onset of non-linear behavior is not a simple function of the output signal level but instead depends on a number of tunable settings. Here we present a method for both determining the onset of non-linear behavior in any installed Reson 7000 series sonar and monitoring the system during real-time acquisition to ensure the system is operating in a linear fashion. In general this information improves the operator’s understanding of the system status and can lead to additional post processing advantages
Neuronal activation for semantically reversible sentences
Semantically reversible sentences are prone to misinterpretation and take longer for typically developing children and adults to comprehend; they are also particularly problematic for those with language difficulties such as aphasia or Specific Language Impairment. In our study, we used fMRI to compare the processing of semantically reversible and nonreversible sentences in 41 healthy participants to identify how semantic reversibility influences neuronal activation. By including several linguistic and nonlinguistic conditions within our paradigm, we were also able to test whether the processing of semantically reversible sentences places additional load on sentence-specific processing, such as syntactic processing and syntactic-semantic integration, or on phonological working memory. Our results identified increased activation for reversible sentences in a region on the left temporal–parietal boundary, which was also activated when the same group of participants carried out an articulation task which involved saying “one, three” repeatedly. We conclude that the processing of semantically reversible sentences places additional demands on the subarticulation component of phonological working memory
Mitochondrial DNA Copy Numbers in Pyramidal Neurons are Decreased and Mitochondrial Biogenesis Transcriptome Signaling is Disrupted in Alzheimer’s Disease Hippocampi
Alzheimer\u27s disease (AD) is the major cause of adult-onset dementia and is characterized in its pre-diagnostic stage by reduced cerebral cortical glucose metabolism and in later stages by reduced cortical oxygen uptake, implying reduced mitochondrial respiration. Using quantitative PCR we determined the mitochondrial DNA (mtDNA) gene copy numbers from multiple groups of 15 or 20 pyramidal neurons, GFAP(+) astrocytes and dentate granule neurons isolated using laser capture microdissection, and the relative expression of mitochondrial biogenesis (mitobiogenesis) genes in hippocampi from 10 AD and 9 control (CTL) cases. AD pyramidal but not dentate granule neurons had significantly reduced mtDNA copy numbers compared to CTL neurons. Pyramidal neuron mtDNA copy numbers in CTL, but not AD, positively correlated with cDNA levels of multiple mitobiogenesis genes. In CTL, but not in AD, hippocampal cDNA levels of PGC1α were positively correlated with multiple downstream mitobiogenesis factors. Mitochondrial DNA copy numbers in pyramidal neurons did not correlate with hippocampal Aβ1-42 levels. After 48 h exposure of H9 human neural stem cells to the neurotoxic fragment Aβ25-35, mtDNA copy numbers were not significantly altered. In summary, AD postmortem hippocampal pyramidal neurons have reduced mtDNA copy numbers. Mitochondrial biogenesis pathway signaling relationships are disrupted in AD, but are mostly preserved in CTL. Our findings implicate complex alterations of mitochondria-host cell relationships in AD
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Observation and analysis of in situ carbonaceous matter in Nakhla: Part I
New analyses of indigenous secondary material in the martian meteorite Nakhla reveal amorphous carbon-rich veins and dendrites. The texture and chemistry of this material resembles that of biogenically altered sub-ocean basaltic glasses
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