Long-Billed Curlew (\u3ci\u3eNumenius americanus\u3c/i\u3e) Rangewide Survey and Monitoring Guidelines

LBCUs are a species of special concern throughout much of their breeding range in North America, with both the U.S. and Canadian Shorebird Plans listing them as “Highly Imperiled” (Brown et al. 2001). LBCUs are also listed in the U.S. as a Bird of Conservation Concern, at the National level, within FWS Regions 1, 2, 4 and 6, and for many Bird Conservation Regions (U.S. Fish and Wildlife Service 2002). This level of concern is due to apparent population declines, particularly in the shortgrass and mixed-grass prairie of the western Great Plains (Brown et al. 2001). Threats include habitat loss and fragmentation due to agricultural conversion (cropland and tame pasture), encroachment of woody vegetation, and urban development. For details on LBCU ecology, management, and conservation, refer to Dugger and Dugger (2002)

The quick and the dead: when reaction beats intention

Everyday behaviour involves a trade-off between planned actions and reaction to environmental events.Evidence from neurophysiology, neurology and functional brain imaging suggests different neural bases for the control of different movement types. Here we develop a behavioural paradigm to test movement dynamics for intentional versus reaction movements and provide evidence for a ‘reactive advantage’ in movement execution, whereby the same action is executed faster in reaction to an opponent. We placed pairs of participants in competition with each other to make a series of button presses. Within subject analysis of movement times revealed a 10 per cent benefit for reactive actions. This was maintained when opponents performed dissimilar actions, and when participants competed against a computer, suggesting that the effect is not related to facilitation produced by action observation. Rather, faster ballistic movements may be a general property of reactive motor control, potentially providing a useful means of promoting survival

Impacts of climate change on aquaculture

• Aquaculture is a significant industry in UK coastal waters, with annual turnover valued at more than £1.8bn. It particularly important in western and northern Scotland. • Aquaculture is sensitive to the marine environment and changes therein. • The dominant contribution of a single species (Atlantic salmon) to production tonnage and value potentially increases vulnerability to climate change. • Temperature increase is expected to increase growth rates for most species farmed. • Increased problems associated with some diseases and parasites, notably sea lice and gill disease (which has emerged as a serious problem), are likely to increase in the short term and to get worse in the longer term. Impacts may be synergistic. • Harmful Algal Blooms (HABs) and jellyfish swarms/invasions may also get worse, however complex ecosystem interactions make responses uncertain. • The situation for shellfish is similar to finfish, although they are additionally at risk of accumulation of toxins from HABs, and recruitment failure, and, in the longer term, to sea-level rises and ocean acidification. • Technical and management changes in the rapidly evolving aquaculture industry make long-term impacts of climate change difficult to forecast

Dipolar versus multipolar dynamos: the influence of the background density stratification

Context: dynamo action in giant planets and rapidly rotating stars leads to a broad variety of magnetic field geometries including small scale multipolar and large scale dipole-dominated topologies. Previous dynamo models suggest that solutions become multipolar once inertia becomes influential. Being tailored for terrestrial planets, most of these models neglected the background density stratification. Aims: we investigate the influence of the density stratification on convection-driven dynamo models. Methods: three-dimensional nonlinear simulations of rapidly rotating spherical shells are employed using the anelastic approximation to incorporate density stratification. A systematic parametric study for various density stratifications and Rayleigh numbers allows to explore the dependence of the magnetic field topology on these parameters. Results: anelastic dynamo models tend to produce a broad range of magnetic field geometries that fall on two distinct branches with either strong dipole-dominated or weak multipolar fields. As long as inertia is weak, both branches can coexist but the dipolar branch vanishes once inertia becomes influential. The dipolar branch also vanishes for stronger density stratifications. The reason is the concentration of the convective columns in a narrow region close to the outer boundary equator, a configuration that favors non-axisymmetric solutions. In multipolar solutions, zonal flows can become significant and participate in the toroidal field generation. Parker dynamo waves may then play an important role close to onset of dynamo action leading to a cyclic magnetic field behavior. Conclusion: Our simulations also suggest that the fact that late M dwarfs have dipolar or multipolar magnetic fields can be explained in two ways. They may differ either by the relative influence of inertia or fall into the regime where both types of solutions coexist.Comment: 13 pages, 13 figures, 2 tables, accepted for publication in A&

Quantifying Stock Price Response to Demand Fluctuations

We address the question of how stock prices respond to changes in demand. We quantify the relations between price change $G$ over a time interval $\Delta t$ and two different measures of demand fluctuations: (a) $\Phi$, defined as the difference between the number of buyer-initiated and seller-initiated trades, and (b) $\Omega$, defined as the difference in number of shares traded in buyer and seller initiated trades. We find that the conditional expectations $<G >_{\Omega}$ and $_{\Phi}$ of price change for a given $\Omega$ or $\Phi$ are both concave. We find that large price fluctuations occur when demand is very small --- a fact which is reminiscent of large fluctuations that occur at critical points in spin systems, where the divergent nature of the response function leads to large fluctuations.Comment: 4 pages (multicol fomat, revtex

Precision Electron-Beam Polarimetry using Compton Scattering at 1 GeV

We report on the highest precision yet achieved in the measurement of the polarization of a low energy, $\mathcal{O}$(1 GeV), electron beam, accomplished using a new polarimeter based on electron-photon scattering, in Hall~C at Jefferson Lab. A number of technical innovations were necessary, including a novel method for precise control of the laser polarization in a cavity and a novel diamond micro-strip detector which was able to capture most of the spectrum of scattered electrons. The data analysis technique exploited track finding, the high granularity of the detector and its large acceptance. The polarization of the $180~\mu$A, $1.16$~GeV electron beam was measured with a statistical precision of $<$~1\% per hour and a systematic uncertainty of 0.59\%. This exceeds the level of precision required by the \qweak experiment, a measurement of the vector weak charge of the proton. Proposed future low-energy experiments require polarization uncertainty $<$~0.4\%, and this result represents an important demonstration of that possibility. This measurement is also the first use of diamond detectors for particle tracking in an experiment.Comment: 9 pages, 7 figures, published in PR

Multiple factors interact to produce responses resembling spectrum of human disease in Campylobacter jejuni infected C57BL/6 IL-10-/- mice

<p>Abstract</p> <p>Background</p> <p><it>Campylobacter jejuni </it>infection produces a spectrum of clinical presentations in humans – including asymptomatic carriage, watery diarrhea, and bloody diarrhea – and has been epidemiologically associated with subsequent autoimmune neuropathies. This microorganism is genetically variable and possesses genetic mechanisms that may contribute to variability in nature. However, relationships between genetic variation in the pathogen and variation in disease manifestation in the host are not understood. We took a comparative experimental approach to explore differences among different <it>C. jejuni </it>strains and studied the effect of diet on disease manifestation in an interleukin-10 deficient mouse model.</p> <p>Results</p> <p>In the comparative study, C57BL/6 interleukin-10^-/-mice were infected with seven genetically distinct <it>C. jejuni </it>strains. Four strains colonized the mice and caused disease; one colonized with no disease; two did not colonize. A DNA:DNA microarray comparison of the strain that colonized mice without disease to <it>C. jejuni </it>11168 that caused disease revealed that putative virulence determinants, including loci encoding surface structures known to be involved in <it>C. jejuni </it>pathogenesis, differed from or were absent in the strain that did not cause disease. In the experimental study, the five colonizing strains were passaged four times in mice. For three strains, serial passage produced increased incidence and degree of pathology and decreased time to develop pathology; disease shifted from watery to bloody diarrhea. Mice kept on an ~6% fat diet or switched from an ~12% fat diet to an ~6% fat diet just before infection with a non-adapted strain also exhibited increased incidence and severity of disease and decreased time to develop disease, although the effects of diet were only statistically significant in one experiment.</p> <p>Conclusion</p> <p><it>C. jejuni </it>strain genetic background and adaptation of the strain to the host by serial passage contribute to differences in disease manifestations of <it>C. jejuni </it>infection in C57BL/6 IL-10^-/-mice; differences in environmental factors such as diet may also affect disease manifestation. These results in mice reflect the spectrum of clinical presentations of <it>C. jejuni </it>gastroenteritis in humans and contribute to usefulness of the model in studying human disease.</p