1,988 research outputs found
GRAIN EXPORTS AS A SOURCE OF AGRICULTURAL INSTABILITY
International Relations/Trade,
Public Opinion and Knowledge of Marine Biodiversity in a Coastal Community - Horry County, South Carolina
There is very little research that explores the public attitude toward marine biodiversity loss as an environmental issue. This study aims to provide insight into the disparities in marine conservation education in order to better provide meaningful education opportunities for coastal communities. The data for this research was collected using a series of semi-structured interviews that were conducted as focus groups of participants from Horry County, South Carolina. Residents from North Myrtle Beach, Myrtle Beach, Loris, and Bucksport were recruited to three focus groups based on their geographical residency. Horry County retirees and students attending Coastal Carolina University were also recruited to two additional focus groups for a total of 5 groups. The results revealed several themes that highlighted general opinions and knowledge levels of the participants. Knowledge of both marine biodiversity as a general topic, as well as its causes and effects, was limited throughout each of the groups. The participants also expressed opinions that attributed the importance of marine biodiversity to its visual beauty. Opinions about the relative importance of economic development and marine biodiversity conservation differed across the groups. Although the consequences of under communication and ineffective education were apparent, the study was enlightening in presenting the possible improvement of scientific communication through relationship building and conversational education
Design of a horizontal neutron reflectometer for the European Spallation Source
A design study of a horizontal neutron reflectometer adapted to the general
baseline of the long pulse European Spallation Source (ESS) is presented. The
instrument layout comprises solutions for the neutron guide, high-resolution
pulse shaping and beam bending onto a sample surface being so far unique in the
field of reflectometry. The length of this instrument is roughly 55 m, enabling
resolutions from 0.5% to 10%. The incident beam is
focussed in horizontal plane to boost measurements of sample sizes of 1*1
cm{^2} and smaller with potential beam deflection in both downward and upward
direction. The range of neutron wavelengths untilized by the instrument is 2 to
7.1 (12.2, ...) {\AA}, if every (second, ...) neutron source ulse is used.
Angles of incidence can be set between 0{\deg} and 9{\deg} with a total
accessible q-range from 4*10^{-3} {\AA}^{-1} up to 1 {\AA}^{-1}. The instrument
operates both in {\theta}/{\theta} (free liquid surfaces) and
{\theta}/2{\theta} (solid/liquid, air/solid interfaces) geometry. The
experimental setup will in particular enable direct studies on ultrathin films
(d ~ 10 {\AA}) and buried monolayers to multilayered structures of up to 3000
{\AA} total thickness. The horizontal reflectometer will further foster
investigations of hierarchical systems from nanometer to micrometer length
scale, as well as their kinetics and dynamical properties, in particular under
load (shear, pressure, external fields). Polarization and polarization analysis
as well as the GISANS option are designed as potential modules to be
implemented separately in the generic instrument layout. The instrument is
highly flexible and offers a variety of different measurement modes. With
respect to its mechanical components the instrument is exclusively based on
current technology. Risks of failure for the chosen setup are minimum.Comment: Matched to the version submitted to Nuclear Instruments and Methods
A Flexible Analytic Model of Cosmic Variance in the First Billion Years
Cosmic variance is the intrinsic scatter in the number density of galaxies
due to fluctuations in the large-scale dark matter density field. In this work,
we present a simple analytic model of cosmic variance in the high redshift
Universe (). We assume that galaxies grow according to the evolution
of the halo mass function, which we allow to vary with large-scale environment.
Our model produces a reasonable match to the observed ultraviolet luminosity
functions in this era by regulating star formation through stellar feedback and
assuming that the UV luminosity function is dominated by recent star formation.
We find that cosmic variance in the UVLF is dominated by the variance in the
underlying dark matter halo population, and not by differences in halo
accretion or the specifics of our stellar feedback model. We also find that
cosmic variance dominates over Poisson noise for future high- surveys except
for the brightest sources or at very high redshifts (). We
provide a linear approximation of cosmic variance for a variety of redshifts,
magnitudes, and survey areas through the public Python package galcv. Finally,
we introduce a new method for incorporating priors on cosmic variance into
estimates of the galaxy luminosity function and demonstrate that it
significantly improves constraints on that important observable
Modular Palladium Bipyrazoles for the Isomerization of Allylbenzenes - Mechanistic Considerations and Insights into Catalyst Design and Activity, Role of Solvent, and Additive Effects
The catalytic activity of novel bidentate N,N-chelated palladium complexes derived from electron excessive, backbone fused 3,3′-bipyrazoles in the selective isomerization of terminal arylpropenoids and 1-alkenes is described. The catalysts are easily modified by appropriate wing tip substitution, while maintaining the same bulky, rigid unreactive aliphatic backbone. Eleven novel palladium complexes with different electronic and steric properties were investigated. Their performance in the palladium(II)-catalyzed isomerization of a series of substituted allylbenzenes was evaluated in terms of electronic as well as steric effects. Besides the clear finding of a general trend towards higher catalyst activity with more electron-donating properties of the coordinated N,N-bidentate ligands, we found that the catalytic process strongly depends on the choice of solvents and additives. Extensive solvent screening revealed that reactions run best in a 2:1 toluene-methanol mixture, with the alcohol employed being a crucial factor in terms of electronic and steric factors. A reaction mechanism involving a hydride addition–elimination mechanism starting with a palladium hydride species generated in situ in alcoholic solutions, as corroborated by experiments using deuterium labeled allylbenzene, seems to be most likely. The proposed mechanism is also supported by the observed reaction rate orders of κobs[cat.]≈1 (0.94), κobs [substrate]=0.20→1.0 (t→∞) and κobs [methanol]=−0.51 for the isomerization of allylbenzene. Furthermore, the influence of acid and base, as well as the role of the halide coordinated to the catalyst, are discussed. The system catalyzes the isomerization of allylbenzenes very efficiently yielding high E:Z selectivities under very mild conditions (room temperature) and at low catalyst loadings of 1 mol% palladium even in unpurified solvents. The integrity and stability of the catalyst system were confirmed by multiple addition reaction cycles, successive filtration and isolation experiments, and the lack of palladium black formation
Grapevine breeding under climate change: Applicability of a molecular marker linked to véraison
Viticulture is of high economic value. Traditional grapevine cultivars (Vitis vinifera L.) are used in adaptation to the climatic conditions from Northern to Southern European growing areas. However, the recent trend of global warming causes quality deficits due to a shift of the plant's development to earlier times in the year. As a consequence, premature ripening happens under warm temperatures and interferes with the balanced accumulation of sugars, acids, aroma profiles and berry coloration. Modern grapevine breeding is challenged to include the ripening behavior as an important trait (besides pathogen resistance and other characteristics) into the development of novel cultivars well suited for sustainable viticulture. Breeders nowadays apply molecular markers to follow the introgression of desired traits on the genetic level. Previous work has identified a molecular tag on grapevine chromosome 16 strongly linked to the time of véraison, the start of the second phase of berry ripening, in a segregating cross population. In this study we analyzed the transferability of this marker to a set of 36 grapevine cultivars commonly used in German viticulture. Association analysis verified the predictive character of the time point of véraison for maturation time and confirmed the diagnostic potential of the véraison-linked marker in this extended set of cultivars
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