1,088 research outputs found

    Modelling trade offs between public and private conservation policies

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    To reduce global biodiversity loss, there is an urgent need to determine the most efficient allocation of conservation resources. Recently, there has been a growing trend for many governments to supplement public ownership and management of reserves with incentive programs for conservation on private land. At the same time, policies to promote conservation on private land are rarely evaluated in terms of their ecological consequences. This raises important questions, such as the extent to which private land conservation can improve conservation outcomes, and how it should be mixed with more traditional public land conservation. We address these questions, using a general framework for modelling environmental policies and a case study examining the conservation of endangered native grasslands to the west of Melbourne, Australia. Specifically, we examine three policies that involve: i) spending all resources on creating public conservation areas; ii) spending all resources on an ongoing incentive program where private landholders are paid to manage vegetation on their property with 5-year contracts; and iii) splitting resources between these two approaches. The performance of each strategy is quantified with a vegetation condition change model that predicts future changes in grassland quality. Of the policies tested, no one policy was always best and policy performance depended on the objectives of those enacting the policy. This work demonstrates a general method for evaluating environmental policies and highlights the utility of a model which combines ecological and socioeconomic processes.Comment: 20 pages, 5 figure

    Effectiveness of Short-Term Heat Acclimation on Intermittent Sprint Performance in the Heat with Moderately Trained Males

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    Purpose: Effectiveness of short-term heat acclimation (STHA), over 5-days (permissive dehydration), on intermittent heat stress test (HST) with males. Methods: Ten, moderately-trained, males (mean [SD]; age 25.6 [8.9] y; stature 180.7 [5.6] cm; body mass 83.2 [10.8] kg; and 45.3 [6.5] mL.kg-1.min-1) participated. The HST was 9 x 5min (45-min) of intermittent exercise based on professional soccer players. One week apart, HST1 vs HST (11.0°C; 50%RH), as a reliability trial and HST3 in 31.0°C; 50%RH were completed. Then 90 min dehydration, STHA (no fluid intake), for 5 consecutive days (39.5oC; 60%RH), using controlled-hyperthermia (~rectal temperature [Tre] 38.5oC). The HST4 within one week after STHA. Blood plasma constituents: percent plasma volume (%PV), aldosterone, total protein, albumin, electrolytes, cortisol and HSP70. Data analysis reported as mean differences with 95% confidence intervals (95%CI) and Cohen’s d effect size. Results: Post STHA, there was a decrease of -0.20 Tre at 45-min in the HST (95%CI -0.40 to -0.05°C; P=0.03; d =-0.56); mean skin temperature (-0.80; -1.30 to -0.30°C; P=0.007; d =-1.46) and mean body temperature (-0.30; -0.50 to -0.10°C, P=0.01; d =-0.75). Cardiac frequency reduced (-3: -5 to -1 b.min-1; P=0.01; d =-0.20) and %PV increased (7.3: 0.9 to 13.7%; P=0.03; d=0.59). Mean Peak Power (MPO) increased (Pd =0.63). Conclusions: Short-term heat acclimation (5-days) with dehydration, using controlled-hyperthermia technique, is effective for physiological adaptations during intermittent exercise in the heat, with moderately trained males

    Block-structured, equal-workload, multi-grid-nesting interface for the Boussinesq wave model FUNWAVE-TVD (Total Variation Diminishing)

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    We describe the development of a block-structured, equal-CPU-load (central processing unit), multi-grid-nesting interface for the Boussinesq wave model FUNWAVE-TVD (Fully Nonlinear Boussinesq Wave Model with Total Variation Diminishing Solver). The new model framework does not interfere with the core solver, and thus the core program, FUNWAVE-TVD, is still a standalone model used for a single grid. The nesting interface manages the time sequencing and two-way nesting processes between the parent grid and child grid with grid refinement in a hierarchical manner. Workload balance in the MPI-based (message passing interface) parallelization is handled by an equal-load scheme. A strategy of shared array allocation is applied for data management that allows for a large number of nested grids without creating additional memory allocations. Four model tests are conducted to verify the nesting algorithm with assessments of model accuracy and the robustness in the application in modeling transoceanic tsunamis and coastal effects

    Effectiveness of short-term heat acclimation on intermittent sprint performance in the heat with moderately trained males.

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    Introduction: Effectiveness of short-term heat acclimation (STHA), over 5-days (permissive dehydration), on intermittent heat stress test (HST) with males. Methods: Ten, moderately-trained, males (mean [SD]; age 25.6 [8.9] y; stature 180.7 [5.6] cm; body mass 83.2 [10.8] kg; and 45.3 [6.5] mL.kg-1.min-1) participated. The HST was 9 x 5min (45-min) of intermittent exercise based on professional soccer players. One week apart, HST1 vs HST (11.0°C; 50%RH), as a reliability trial and HST3 in 31.0°C; 50%RH were completed. Then 90 min dehydration, STHA (no fluid intake), for 5 consecutive days (39.5oC; 60%RH), using controlled-hyperthermia (~rectal temperature [Tre] 38.5oC). The HST4 within one week after STHA. Blood plasma constituents: percent plasma volume (%PV), aldosterone, total protein, albumin, electrolytes, cortisol and HSP70. Data analysis reported as mean differences with 95% confidence intervals (95%CI) and Cohen’s d effect size. Results: Post STHA, there was a decrease of -0.20 Tre at 45-min in the HST (95%CI -0.40 to -0.05°C; P=0.03; d =-0.56); mean skin temperature (-0.80; -1.30 to -0.30°C; P=0.007; d =-1.46) and mean body temperature (-0.30; -0.50 to -0.10°C, P=0.01; d =-0.75). Cardiac frequency reduced (-3: -5 to -1 b.min-1; P=0.01; d =-0.20) and %PV increased (7.3: 0.9 to 13.7%; P=0.03; d=0.59). Mean Peak Power (MPO) increased (P<0.05) across sprints 7, 8 and 9. Time to exhaustion increased (167: -15 to 350 s; P=0.06; d =0.63). Conclusions: Short-term heat acclimation (5-days) with dehydration, using controlled-hyperthermia technique, is effective for physiological adaptations during intermittent exercise in the heat, with moderately-trained males

    The Habitable-Zone Planet Finder: A Stabilized Fiber-Fed NIR Spectrograph for the Hobby-Eberly Telescope

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    We present the scientific motivation and conceptual design for the recently funded Habitable-zone Planet Finder (HPF), a stabilized fiber-fed near-infrared (NIR) spectrograph for the 10 meter class Hobby-Eberly Telescope (HET) that will be capable of discovering low mass planets around M dwarfs. The HPF will cover the NIR Y & J bands to enable precise radial velocities to be obtained on mid M dwarfs, and enable the detection of low mass planets around these stars. The conceptual design is comprised of a cryostat cooled to 200K, a dual fiber-feed with a science and calibration fiber, a gold coated mosaic echelle grating, and a Teledyne Hawaii-2RG (H2RG) NIR detector with a 1.7μ\mum cutoff. A uranium-neon hollow-cathode lamp is the baseline wavelength calibration source, and we are actively testing laser frequency combs to enable even higher radial velocity precision. We will present the overall instrument system design and integration with the HET, and discuss major system challenges, key choices, and ongoing research and development projects to mitigate risk. We also discuss the ongoing process of target selection for the HPF survey.Comment: 14 pages, 9 figures. To appear in the proceedings of the SPIE 2012 Astronomical Instrumentation and Telescopes conferenc

    A complete view of galaxy evolution: panchromatic luminosity functions and the generation of metals

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    When and how did galaxies form and their metals accumulate? Over the last decade, this has moved from an archeological question to a live investigation: there is now a broad picture of the evolution of galaxies in dark matter halos: their masses, stars, metals and supermassive blackholes. Galaxies have been found and studied in which these formation processes are taking place most vigorously, all the way back in cosmic time to when the intergalactic medium (IGM) was still largely neutral. However, the details of how and why the interstellar medium (ISM) in distant galaxies cools, is processed, recycled and enriched in metals by stars, and fuels active galactic nuclei (AGNs) remain uncertain. In particular, the cooling of gas to fuel star formation, and the chemistry and physics of the most intensely active regions is hidden from view at optical wavelengths, but can be seen and diagnosed at mid- & far-infrared (IR) wavelengths. Rest-frame IR observations are important first to identify the most luminous, interesting and important galaxies, secondly to quantify accurately their total luminosity, and finally to use spectroscopy to trace the conditions in the molecular and atomic gas out of which stars form. In order to map out these processes over the full range of environments and large-scale structures found in the universe - from the densest clusters of galaxies to the emptiest voids - we require tools for deep, large area surveys, of millions of galaxies out to z~5, and for detailed follow-up spectroscopy. The necessary tools can be realized technically. Here, we outline the requirements for gathering the crucial information to build, validate and challenge models of galaxy evolution.Comment: A whitepaper submitted on 15th February 2009 in response to the call from the Astro2010 panel: astro2010.org; uploaded as an 8-page pdf fil

    Measurement Techniques for Steady Shear Viscosity of Mozzarella-Type Cheeses at High Shear Rates and High Temperature

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    While measuring steady shear viscosity of Mozzarella-type cheeses in a rotational rheometer at 70 °C, three main difficulties were encountered; wall slip, structural failure during measurement and viscoelastic time dependent effects. Serrated plates were the most successful surface modification at eliminating wall slip. However, even with serrated plates shear banding occurred at higher shear rates. Because of the viscoelastic nature of the cheeses, a time dependent viscous response occurred at shear rates \u3c1 \u3es−1, requiring longer times to attain steady shear conditions. Prolonged continuous shearing altered the structure of the molten cheeses. The effects of structural change were greatly reduced by minimising the total accumulated strain exerted on the sample during flow curve determination. These techniques enabled successful measurement of steady shear viscosity of molten Mozzarella-type cheeses at 70 °C at shear rates up to 250 s−1

    On the Spectral Evolution of Cool, Helium-Atmosphere White Dwarfs: Detailed Spectroscopic and Photometric Analysis of DZ Stars

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    We present a detailed analysis of a large spectroscopic and photometric sample of DZ white dwarfs based on our latest model atmosphere calculations. We revise the atmospheric parameters of the trigonometric parallax sample of Bergeron, Leggett, & Ruiz (12 stars) and analyze 147 new DZ white dwarfs discovered in the Sloan Digital Sky Survey. The inclusion of metals and hydrogen in our model atmosphere calculations leads to different atmospheric parameters than those derived from pure helium models. Calcium abundances are found in the range from log (Ca/He) = -12 to -8. We also find that fits of the coolest objects show peculiarities, suggesting that our physical models may not correctly describe the conditions of high atmospheric pressure encountered in the coolest DZ stars. We find that the mean mass of the 11 DZ stars with trigonometric parallaxes, = 0.63 Mo, is significantly lower than that obtained from pure helium models, = 0.78 Mo, and in much better agreement with the mean mass of other types of white dwarfs. We determine hydrogen abundances for 27% of the DZ stars in our sample, while only upper limits are obtained for objects with low signal-to-noise ratio spectroscopic data. We confirm with a high level of confidence that the accretion rate of hydrogen is at least two orders of magnitude smaller than that of metals (and up to five in some cases) to be compatible with the observations. We find a correlation between the hydrogen abundance and the effective temperature, suggesting for the first time empirical evidence of a lower temperature boundary for the hydrogen screening mechanism. Finally, we speculate on the possibility that the DZA white dwarfs could be the result of the convective mixing of thin hydrogen-rich atmospheres with the underlying helium convection zone.Comment: 67 pages, 32 figures, accepted for publication in Ap

    A new species of Illacme from southern California (Siphonophorida, Siphonorhinidae)

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    The millipede fauna inhabiting deep soil are poorly known. They are small and threadlike, slow moving, lacking pigmentation, and rarely encountered due to their obscure underground way of life. One family, the Siphonorhinidae, encompasses four genera and 12 species in a fragmentary distribution in California, southern Africa, Madagascar, the Malay Archipelago, and Indo-Burma. The family is represented in the Western Hemisphere by a single genus, Illacme Cook &amp;amp; Loomis, 1928 from California, with its closest known relative, Nematozonium filum Verhoeff, 1939, from southern Africa. A new species of this family is documented from soil microhabitats in the Los Angeles metropolitan area, Illacme socal Marek &amp;amp; Shear, sp. nov. Based on this discovery and the recent documentation of other endogean millipede species, we show that these grossly understudied subterranean fauna represent the next frontier of discovery. However, they are threatened by encroaching human settlement and habitat loss, and conservation of this species and other subterranean fauna is of high importance
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