Speciation in Golden-Plovers, Pluvialis dominica and P. fulva: Evidence from the Breeding Grounds

Two forms of golden-plover have long been considered subspecies, Pluvialisdominica dominica and P. d. fulva. Prior studies have shown differences between forms in breeding distributions, wintering distributions, plumage, morphology, molt, and maturation schedules. We report clear and consistent differences in breeding vocalizations and nesting habitat, and strict assortative mating in areas of sympatry in western Alaska. These results indicate a greater degree of differentiation between the forms than was previously appreciated. They are appropriately treated as separate species and should be referred to under the names Pluvialis dominica, for the American Golden-Plover, and Pluvialis fulva, for the Pacific Golden-Plover

Breeding Ground Fidelity and Mate Retention in the Pacific Golden-Plover

We found male-biased site fidelity in Pacific Golden-Plovers (Phviah fulva)on breeding grounds in western Alaska. Males (8 of 8) returned to the same territories annually, while few females (1 of 4) were seen in subsequent seasons. Nest sites in successive years were usually within 100 m, and the same nest cup may be used in more than one year. First-year birds of both sexes mated with older birds and also with each other, but first-year females may breed less commonly than first-year males. The numbers of nesting birds on our study sites varied sharply both within and between seasons

The Impacts of a Nonindigenous Marine Predator in a California Bay

Coastal marine ecosystems worldwide are being altered rapidly by the invasion of nonindigenous species. Unlike terrestrial and freshwater systems, the impacts of an invading species have never been quantified on multiple trophic levels for a marine food web. We measured the impact of the nonindigenous green crab, Carcinus maenas, on a coastal marine food web in central California and found that this predator exerted strong “top-down” control, significantly reducing the abundances of several of the 20 invertebrate species monitored over a 9-yr period. Densities of native clams, Nutricola tantilla and Nutricola confusa, and native shore crabs, Hemigrapsus oregonensis, showed 5-fold to 10-fold declines within 3 yr of the arrival of green crabs. Field and laboratory experiments indicated that green crab predation caused these declines. We also tested for indirect responses of invertebrates and vertebrates to green crab predation. There were significant increases in the abundances of two polychaete taxa, Lumbrineris sp. and Exogene sp., and tube-building tanaid crustaceans, Leptochelia dubia, most likely due to the removal of co-occurring green crab prey. However, we observed no changes in shorebird abundances (13 species) over a 9-yr period suggesting that green crabs have had no “bottom-up” effect on shorebirds, which subsist on benthic invertebrate prey. We predict that such bottom-up control will occur as the local effects and geographic range of green crabs increase. The 2-yr temporal scale of direct and indirect responses of the invertebrates in this low energy, soft-substrate system was also in agreement with the results of perturbation experiments by others on rocky shores, which showed that most direct and indirect responses also occur within a 2-yr time frame

The external benefits of higher education

The private market benefits of education are widely studied at the micro level, although the magnitude of their macroeconomic impact is disputed. However, there are additional benefits of education, which are less well understood. In this paper the macroeconomic effects of external benefits of higher education are estimated using the “micro-to-macro” simulation approach. Two types of externalities are explored: technology spillovers and productivity spillovers in the labour market. These links are illustrated and the results suggest they could be very large. However, this is qualified by the dearth of microeconomic evidence, for which we hope to encourage further work

Transverse-Momentum Dependence of the J/psi Nuclear Modification in d+Au Collisions at sqrt(s_NN)=200 GeV

We present measured J/psi production rates in d+Au collisions at sqrt(s_NN) = 200 GeV over a broad range of transverse momentum (p_T=0-14 GeV/c) and rapidity (-2.2<y<2.2). We construct the nuclear-modification factor R_dAu for these kinematics and as a function of collision centrality (related to impact parameter for the R_dAu collision). We find that the modification is largest for collisions with small impact parameters, and observe a suppression (R_dAu<1) for p_T<4 GeV/c at positive rapidities. At negative rapidity we observe a suppression for p_T1) for p_T>2 GeV/c. The observed enhancement at negative rapidity has implications for the observed modification in heavy-ion collisions at high p_T.Comment: 384 authors, 24 pages, 19 figures, 13 tables. Submitted to Phys. Rev. C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are publicly available at http://www.phenix.bnl.gov/phenix/WWW/info/data/ppg123_data.htm

GMAG: An open-source python package for ground-based magnetometers

Magnetometers are a key component of heliophysics research providing valuable insight into the dynamics of electromagnetic field regimes and their coupling throughout the solar system. On satellites, magnetometers provide detailed observations of the extension of the solar magnetic field into interplanetary space and of planetary environments. At Earth, magnetometers are deployed on the ground in extensive arrays spanning the polar cap, auroral and sub-auroral zone, mid- and low-latitudes and equatorial electrojet with nearly global coverage in azimuth (longitude or magnetic local time—MLT). These multipoint observations are used to diagnose both ionospheric and magnetospheric processes as well as the coupling between the solar wind and these two regimes at a fraction of the cost of in-situ instruments. Despite their utility in research, ground-based magnetometer data can be difficult to use due to a variety of file formats, multiple points of access for the data, and limited software. In this short article we review the Open-Source Python library GMAG which provides rapid access to ground-based magnetometer data from a number of arrays in a Pandas DataFrame, a common data format used throughout scientific research

Initial performance of Bicep3: a degree angular scale 95 GHz band polarimeter

Bicep3 is a 550-mm aperture telescope with cold, on-axis, refractive optics designed to observe at the 95-GHz band from the South Pole. It is the newest member of the Bicep/Keck family of inflationary probes specifically designed to measure the polarization of the cosmic microwave background (CMB) at degree angular scales. Bicep3 is designed to house 1280 dual-polarization pixels, which, when fully populated, totals to ∼9× the number of pixels in a single Keck 95-GHz receiver, thus further advancing the Bicep/Keck program’s 95 GHz mapping speed. Bicep3 was deployed during the austral summer of 2014–2015 with nine detector tiles, to be increased to its full capacity of 20 in the second season. After instrument characterization, measurements were taken, and CMB observation commenced in April 2015. Together with multi-frequency observation data from Planck, Bicep2, and the Keck Array, Bicep3 is projected to set upper limits on the tensor-to-scalar ratio to r≲0.03 at 95 % C.L

Impact of Tai Chi exercise on multiple fracture-related risk factors in post-menopausal osteopenic women: a pilot pragmatic, randomized trial

Background: Tai Chi (TC) is a mind-body exercise that shows potential as an effective and safe intervention for preventing fall-related fractures in the elderly. Few randomized trials have simultaneously evaluated TC's potential to reduce bone loss and improve fall-predictive balance parameters in osteopenic women. Methods: In a pragmatic randomized trial, 86 post-menopausal osteopenic women, aged 45-70, were recruited from community clinics. Women were assigned to either nine months of TC training plus usual care (UC) vs. UC alone. Primary outcomes were changes between baseline and nine months of bone mineral density (BMD) of the proximal femur and lumbar spine (dual-energy X-ray absorptiometry) and serum markers of bone resorption and formation. Secondary outcomes included quality of life. In a subsample (n = 16), quiet standing fall-predictive sway parameters and clinical balance tests were also assessed. Both intent-to-treat and per-protocol analyses were employed. Results: For BMD, no intent-to-treat analyses were statistically significant; however, per protocol analyses (i.e., only including TC participants who completed $\geq$ 75% training requirements) of femoral neck BMD changes were significantly different between TC and UC (+0.04 vs. -0.98%; P = 0.05). Changes in bone formation markers and physical domains of quality of life were also more favorable in per protocol TC vs. UC (P = 0.05). Changes in sway parameters were significantly improved by TC vs. UC (average sway velocity, P = 0.027; anterior-posterior sway range, P = 0.014). Clinical measures of balance and function showed non-significant trends in favor of TC. Conclusions: TC training offered through existing community-based programs is a safe, feasible, and promising intervention for reducing multiple fracture risks. Our results affirm the value of a more definitive, longer-term trial of TC for osteopenic women, adequately powered to detect clinically relevant effects of TC on attenuation of BMD loss and reduction of fall risk in this population

Tai Chi for osteopenic women: design and rationale of a pragmatic randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Post-menopausal osteopenic women are at increased risk for skeletal fractures. Current osteopenia treatment guidelines include exercise, however, optimal exercise regimens for attenuating bone mineral density (BMD) loss, or for addressing other fracture-related risk factors (e.g. poor balance, decreased muscle strength) are not well-defined. Tai Chi is an increasingly popular weight bearing mind-body exercise that has been reported to positively impact BMD dynamics and improve postural control, however, current evidence is inconclusive. This study will determine the effectiveness of Tai Chi in reducing rates of bone turnover in post-menopausal osteopenic women, compared with standard care, and will preliminarily explore biomechanical processes that might inform how Tai Chi impacts BMD and associated fracture risks.</p> <p>Methods/Design</p> <p>A total of 86 post-menopausal women, aged 45-70y, T-score of the hip and/or spine -1.0 and -2.5, have been recruited from primary care clinics of a large healthcare system based in Boston. They have been randomized to a group-based 9-month Tai Chi program plus standard care or to standard care only. A unique aspect of this trial is its pragmatic design, which allows participants randomized to Tai Chi to choose from a pre-screened list of community-based Tai Chi programs. Interviewers masked to participants' treatment group assess outcomes at baseline and 3 and 9 months after randomization. Primary outcomes are serum markers of bone resorption (C-terminal cross linking telopeptide of type I collagen), bone formation (osteocalcin), and BMD of the lumbar spine and proximal femur (dual-energy X-ray absorptiometry). Secondary outcomes include health-related quality-of-life, exercise behavior, and psychological well-being. In addition, kinetic and kinematic characterization of gait, standing, and rising from a chair are assessed in subset of participants (n = 16) to explore the feasibility of modeling skeletal mechanical loads and postural control as mediators of fracture risk.</p> <p>Discussion</p> <p>Results of this study will provide preliminary evidence regarding the value of Tai Chi as an intervention for decreasing fracture risk in osteopenic women. They will also inform the feasibility, value and potential limitations related to the use of pragmatic designs for the study of Tai Chi and related mind-body exercise. If the results are positive, this will help focus future, more in-depth, research on the most promising potential mechanisms of action identified by this study.</p> <p>Trial registration</p> <p>This trial is registered in Clinical Trials.gov, with the ID number of NCT01039012.</p