8,713 research outputs found
Evaluating the success of seed sowing in a New England grassland
Grassland habitat is declining in the northeastern United States, leading to a decline in associated native species. Consequently, there is considerable interest by land managers in conserving and restoring grassland habitats in the Northeast. However, unlike the Great Plains and Europe, quantitative monitoring of restoration sites is uncommon, making it difficult to improve new restoration projects. Here we evaluate a grassland restoration in Waterford, Connecticut to determine if mechanical clearing of woody vegetation combined with sowing 23 native grasses and forbs led to successful establishment of these species. We also compared cover, diversity, and colonization by exotic and woody species in planted and unplanted areas over time. In the third and fifth growing seasons after planting in 2006, we sampled the vegetation in the planted site, an unplanted zone within the planted grassland, and an adjacent unplanted grassland. Twenty of the 23 sown species established by 2010, and sown species dominated the planted area (70% of total cover). Despite the successful establishment of most sown species, species richness and diversity were no higher in the sown grassland than in adjacent unseeded areas. However, the sown grassland contained lower cover of non-native and invasive species. Big bluestem (Andropogon gerardii Vitman) established aggressively, potentially reducing both exotic colonization and native diversity. This study shows that sowing native grassland species can lead to the successful development of native-dominated grasslands. Results can inform future grassland restoration efforts in the Northeast and show that seeding with aggressive grass species may greatly impact restored plant communities
SOCIAL PROBLEMS, BIOMEDICAL ANSWERS? HOW CAUSES OF SOCIAL PROBLEMS AFFECT CHOICE OF SOLUTIONS
With rapid advances in behavioural genetics, scientists are identifying an increasing array of genetic influences on human behaviour. Public misconceptions about the function of genes often lead to the oversimplification of the role of genes in behaviour (Dar-Nimrod & Heine, 2011). To date, no study has systematically investigated whether simply learning about genetic causes of behaviour affects people’s preferred solutions to problematic behaviours. The present research program includes three studies that were designed to examine the psychological effects of exposure to genetic etiology for problematic behaviour, in particular aggression, and investigated how this information influences endorsement of solutions, rating of effectiveness, and support for research funding. It was predicted that compared to a psycho-social etiological emphasis, a genetic etiological emphasis would increase preference for biomedical approaches.
Participants read an article outlining the multi-determined nature of aggression, either emphasizing a newly-discovered genetic or an environmental cause of aggression which accounted for behavioural aggression in 30% of those with the predisposition. Across all three studies, the genetic emphasis increased preference for biomedicine compared to a psycho-social emphasis of aggression. In Studies 2 and 3 the psycho-social emphasis also increased preference for socio-behavioural approaches to aggression. These results underscore the importance of considering how media reports of genetic influences on behaviour can meaningfully affect people’s beliefs about treatments and solutions to social issues. In Study 1 and 3, assigning responsibility to genetic or environmental factors for aggression mediates solution preferences and preliminary evidence from Study 3 suggests that coherence of arguments, perceptions about personal responsibility and predispositions increases the effects of the emphasis condition. The effect of emphasis was also discussed in relation to additional variables. Findings from this program of research contribute to best practices for professionals and journalists when conveying genetic research to the public
Automated mass spectrometer/analysis system: A concept
System performs rapid multiple analyses of entire compound classes or individual compounds on small amounts of sample and reagent. Method will allow screening of large populations for metabolic disorders and establishment of effective-but-safe levels of therapeutic drugs in body fluids and tissues
Behavior of the Dripping Faucet over a Wide Range of the Flow Rate
The time interval of successive water-drips from a faucet was examined over a
wide range of the flow rate. The dripping interval alternately exhibits a
stable state and a chaotic state as the flow rate increases. In the stable
state, the volume of the drip is kept constant at fixed flow rates, and the
constant volume increases with the flow rate. In the chaotic state, in addition
to a mechanics that the drip is torn by its own weight, the vibration of the
drip on the faucet takes part in the strange behavior of the interval.Comment: 7 pages, 7 figures, to be published in J. Phys. Soc. Jpn vol
68-2(1999
The effect of stellar limb darkening values on the accuracy of the planet radii derived from photometric transit observations
We study how the precision of the exoplanet radius determination is affected
by our present knowledge of limb darkening in two cases: when we fix the limb
darkening coefficients and when we adjust them. We also investigate the effects
of spots in one-colour photometry. We study the effect of limb darkening on the
planetary radius determination both via analytical expressions and by numerical
experiments. We also compare some of the existing limb darkening tables. When
stellar spots affect the fit, we replace the limb darkening coefficients,
calculated for the unspotted cases, with effective limb darkening coefficients
to describe the effect of the spots. There are two important cases. (1) When
one fixes the limb darkening values according to some theoretical predictions,
the inconsistencies of the tables do not allow us to reach accuracy in the
planetary radius of better than 1-10% (depending on the impact parameter) if
the host star's surface effective temperature is higher than 5000 K. Below 5000
K the radius ratio determination may contain even 20% error. (2) When one
allows adjustment of the limb darkening coefficients, the a/Rs ratio, the
planet-to-stellar radius ratio, and the impact parameter can be determined with
sufficient accuracy (<1%), if the signal-to-noise ratio is high enough.
However, the presence of stellar spots and faculae can destroy the agreement
between the limb darkening tables and the fitted limb darkening coefficients,
but this does not affect the precision of the planet radius determination. We
also find that it is necessary to fit the contamination factor, too. We
conclude that the present inconsistencies of theoretical stellar limb darkening
tables suggests one should not fix the limb darkening coefficients. When one
allows them to be adjusted, then the planet radius, impact parameter, and the
a/Rs can be obtained with the required precision.Comment: Astronomy & Astrophysics Vol. 549, A9 (2013) - 11 page
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