The large-scale axisymmetric magnetic topology of a very-low-mass fully convective star     

Donati JF  Forveille T  Cameron AC  Barnes JR  Delfosse X  Jardine MM  Valenti JA 《Science (New York, N.Y.)》2006,311(5761):633-635

Understanding how cool stars produce magnetic fields within their interiors is crucial for predicting the impact of such fields, such as the activity cycle of the Sun. In this respect, studying fully convective stars enables us to investigate the role of convective zones in magnetic field generation. We produced a magnetic map of a rapidly rotating, very-low-mass, fully convective dwarf through tomographic imaging from time series of spectropolarimetric data. Our results, which demonstrate that fully convective stars are able to trigger axisymmetric large-scale poloidal fields without differential rotation, challenge existing theoretical models of field generation in cool stars.  相似文献   

Feline Seizures: What's New?     

Heidi Barnes Heller 《Advances in Small Animal Medicine and Surgery》2017,30(6):1-3

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Canine Inflammatory Brain Disease: The Past,Present, and Future     

Heidi L. Barnes Heller 《Advances in Small Animal Medicine and Surgery》2017,30(9):1-2

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Surgical management of primary,metastatic and recurrent anal sac adenocarcinoma in the dog: 52 cases          下载免费PDF全文

D. C. Barnes  J. L. Demetriou 《The Journal of small animal practice》2017,58(5):263-268

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Importance of forest buffers for preserving soil carbon and nutrient stocks in farmed landscapes along two river sites in the savannas of the Volta basin,Ghana     

Emmanuel Amoah Boakye  Dibi N’da Hyppolite  Victor Rex Barnes  Stefan Porembski 《Arid Land Research and Management》2017,31(2):219-233

Understanding the impacts of agricultural land use is desired for proper management of riparian forests buffers (RFs) in savannas. In this light, we analyzed the relationship between woody plant diversity and soil properties of RFs in farmlands (FAs) and protected areas (PAs) along Afram (Guinean zone) and Tankwidi (Sudanian zone) Rivers located within the Volta sub-basin of Ghana. ALOS-AVNIR imageries were used to map RFs to facilitate sampling of soil and woody vegetation (dbh ≥5?cm) using stratified randomized design (72 plots; size: 500?m² each) for the analysis of soil physical and chemical properties and Shannon-Wiener plant species diversity. Although the fractions of sand, silt, and clay varied between the PAs and FAs, they were predominantly categorized as sandy loam. Along the Afram River, there were no significant differences in the concentrations and nutrient stocks of soil C, N, P, and K as well as the pH, moisture content, and bulk density between PA and FA. For the Tankwidi River, the concentrations and nutrient stocks of C and K significantly decreased from PA to FA while N, P, pH, bulk density, and moisture content were not different. Of the soil attributes measured C, N, P, pH, ground slope, and soil moisture had significant relationships with the diversity and density of the riparian woody plants. Controlling agricultural activities in riparian forests could preserve soil properties similar to that found in protected areas.  相似文献   

Modeling impact of nitrogen carrier and concentration on root substrate pH     

Jared Barnes  Paul V. Nelson  Dean Hesterberg  Wei Shi  Brian E. Whipker 《Journal of plant nutrition》2017,40(15):2101-2108

We conducted an experiment to quantify the effects on substrate pH from nitrogen (N) carrier and concentration. We used four concentrations of N (3.5–14 mM) and five fractions of ammonium (NH₄⁺) (0–80% NH₄⁺ of total N) that are found in commercially available fertilizers. Fertilizers were applied to fallow 14-cm-diameter pots (1.29 L) filled with a 3 peat:1 perlite (v/v) substrate amended with non-residual powdered calcium carbonate to raise the substrate pH to approximately 6.0. Harvests occurred at 20 and 42 days. Significant effects in the model included main effects of N carrier and N concentration, their squared terms, an interaction effect, and a time × N carrier. The fraction of NH₄⁺ accounted for 45.0% of variation in substrate pH, and N concentration accounted for 1.5% of the total R² of 76.7%. Substrate acidification was likely due to the physiological fertilizer effect and nitrification.  相似文献   

Utility of high-density plantings in bay scallop, Argopecten irradians irradians, restoration     

Stephen T. Tettelbach  Debra Barnes  John Aldred  Gregg Rivara  Dennis Bonal  Andrew Weinstock  Chelsea Fitzsimons-Diaz  Josh Thiel  M. Chase Cammarota  Adam Stark  Katherine Wejnert  Richard Ames  John Carroll 《Aquaculture International》2011,19(4):715-739

Two different methods of establishing high-density spawner sanctuaries for bay scallop (Argopecten irradians irradians) restoration were evaluated over 2 years at a site in Northwest Harbor, East Hampton, New York, USA. Hatchery-reared scallops, which had been overwintered at nearby sites, were free-planted directly to the bottom in late March/early April at an initial target density of 94?C128 scallops/m². In addition, scallops were stocked in off-bottom culture units consisting of three vertically stacked 15-mm mesh ADPI^® bags at densities of 50, 100, or 200 scallops/bag (=117, 234, or 468 scallops/m²), respectively. Survival of scallops differed significantly by year, planting method, and scallop source. Survival of free-planted scallops was generally lower than caged scallops. Better survival of free-planted scallops in 2005 versus 2006 likely reflected the presence of luxuriant eelgrass beds in 2005, which were absent in 2006. Survival of scallops in ADPI bags was not appreciably related to stocking density. Shell growth was highest for free-planted scallops; in cages, growth was somewhat better at 50 versus 200 scallops/bag. Wet weights of epibionts were significantly higher in caged versus free-planted scallops. Reproductive condition of scallops stocked at 50/bag was usually higher than at 200/bag. Both free-planting and off-bottom systems yielded high densities of adult bay scallops at the time of spawning, which ensures a higher probability of successful fertilization of spawned eggs and thus a greater potential for success of restoration efforts.  相似文献