89 research outputs found
Converting a series in \lambda to a series in \lambda^{-1}
We introduce a transformation for converting a series in a parameter,
\lambda, to a series in the inverse of the parameter \lambda^{-1}. By applying
the transform on simple examples, it becomes apparent that there exist
relations between convergent and divergent series, and also between large- and
small-coupling expansions. The method is also applied to the divergent series
expansion of Euler-Heisenberg-Schwinger result for the one-loop effective
action for constant background magnetic (or electric) field. The transform may
help us gain some insight about the nature of both divergent (Borel or
non-Borel summable series) and convergent series and their relationship, and
how both could be used for analytical and numerical calculations.Comment: 7 pages, Latex, 3 figures; Typos corrected. To appear in Journal of
Physics A: Math and Ge
Assessment of emergency medical services in the Ashanti region of Ghana
Background: We aimed to assess the structure, function and performance of Ashanti Region’s emergency medical services system in the context of the regional need for prehospital emergency care.Design: A mixed-methods approach was employed, using retrospective collection of quantitative data and prospectively gathered qualitative data. Setting – pertinent data were collected from Ghanaian and international sources; interviews and technical assessments were performed primarily in the Ashanti Region of Ghana.Participants: All stakeholders relevant to emergency medical services in the Ashanti Region of Ghana were assessed; there was a special focus on National Ambulance Service (NAS) and Ashanti Region healthcare personnel.Intervention: This was an observational study using qualitative and quantitative assessment techniques.Main outcome measures: The structure, function and performance of the Ashanti emergency medical services system, guided by a relevant technical assessment framework.Results: NAS is the premier and only true prehospital agency in the Ashanti Region. NAS has developed almost every essential aspect of an EMS system necessary to achieve its mission within a low-resource setting. NAS continues to increase its number of response units to address the overwhelming Ashanti region demand, especially primary calls. Deficient areas in need of development are governance, reliable revenue, public access, community integration, clinical care guidelines, research and quality assurance processes.Conclusions: The Ashanti Region has a growing and thriving emergency medical services system. Although many essential areas for development were identified, NAS is well poised to meet the regional demand for prehospital emergency care and transport.Keywords: EMS, prehospital, ambulance, emergency, Ghana, Afric
Multi-Year Application of Dairy Slurry on Grassland: Effects on Crop, Soil Biota, Soil Nutrients, and N\u3csub\u3e2\u3c/sub\u3eO Emission
The long-term effects of using manure as the principal nutrient source in intensive crop production systems are not well known. This paper reports on the effects of multi-year application of fertilizer or dairy slurry on a tall fescue (Festuca arundinacea Schreb.) sward. Slurry sustained greater grass yield than chemical fertilizer. Unlike fertilizer, slurry supplied 70 to 120 kg N/ha one year after application but little after one year; 4-years of manure applications built up the stable organic matter pool in the soil. Manure-N was less prone to leaching but more prone to N2O emissions than fertilizer-N. Manured soils had considerably more biological activity than fertilized soils. High rates of manure application increased soil P
Resuscitation of Severe Uncontrolled Hemorrhage 7.5% Sodium Chloride/6% Dextran 70 vs 0.9% Sodium Chloride
Objectives: Resuscitation studies of hypertonic saline using controlled and uncontrolled hemorrhage models yield conflicting results with regard to efficacy. These disparate results reflect the use of models and resuscitation regimens that are not comparable between studies. This study evaluated the effects of comparable and clinically relevant resuscitation regimens of 7.5% sodium chloride/6% dextran 70 (HSD) and 0.9% sodium chloride (NS) in a near-fatal uncontrolled hemorrhage model. Methods: Thirty-six swine (14.2 to 21.4 kg) with 4-mm aortic tears were bled to a pulse pressure of 5 mm Hg (40-45 mL/kg). The animals were resuscitated with either NS or HSD administered in volumes that provided equivalent sodium loads at similar rates. Group II (n = 12) was resuscitated with 80 mL/kg of NS at a rate of 4 mL/kg/min. Group III (n = 12) received 9.6 mL/kg of HSD at a rate of 0.48 mL/kg/min. In both groups, crystalloid resuscitation was followed by shed blood infusion (30 mL/kg) at a rate of 2 mL/kg/min. Group I (controls; n = 12) were not resuscitated. Results: One-hour mortality was significantly greater in group I (92%) as compared with group II (33%) and group III (33%) (Fisher's exact test; p = 0.004). Intraperitoneal hemorrhage was significantly greater in group II (34 ± 20 mL/kg) and group III (31 ± 13 mL/kg) as compared with group I (5 ± 2 mL/kg) (ANOVA; p < 0.05). There was no significant difference in hemodynamic parameters between groups II and III. Conclusion: In this model of severe uncontrolled hemorrhage, resuscitation with HSD or NS, administered in volumes that provided equivalent sodium loads at similar rates, had similar effects on mortality, hemodynamic parameters, and hemorrhage from the injury site.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73625/1/j.1553-2712.2000.tb02060.x.pd
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Defoliation and cold-hardiness of northern wheatgrass
Freezing temperatures in winter were hypothesized to be a major cause of mortality of tillers following defoliation of northern wheatgrass (Agropyron dasystachyum [Hook.] Scribn., syn. Elymus lanceolatus [Scribn. & Smith] Gould). Cold-hardiness of northern wheatgrass tillers was determined following a single mowing to a 5-cm stubble height in late May, June, July, or August in 1992 or 1993 in southwestern Saskatchewan. An unmowed control was also included. Cold-hardiness was determined in early and late winter immediately following mowing by: 1) exposing tillers to controlled temperatures ranging from -3 to -36 degrees C, or; 2) exposing them to -15 degrees C for 0 to 15 days. The LT50 (temperature at which 50% of tillers died) of northern wheatgrass tillers in early winter ranged from -29.5 to < -36.0 degrees C in 1992-93, and averaged -24.0 degrees C in 1993-94. In late winter LT50 ranged from -18.1 to -22.6 degrees C in 1992-1993, and it averaged -22.0 degrees C in 1993-1994. The LDur50 (duration at which 50% of tillers died) of tillers exposed to -15 degrees C for 0 to 15 days ranged from 8.0 to 13.1 days in early winter, and 2.7 to 4.7 days in late winter. Unexpectedly mowed tillers were generally more cold-hardy than those from control. In early winter LT50 was 1.5 to 10 degrees C lower for mowed than control tillers. The hypothesis that defoliation reduces cold-hardiness of northern wheatgrass was rejected. The degree or duration of cold stress in the field is generally insufficient to reduce tiller survival in northern wheatgrass. Late winter through early spring is a critical period for tiller survival of northern wheatgrass because cold-hardiness declines this time of the year. Maintaining insulating cover can moderate soil temperatures and reduce damage to plants from freezing temperatures.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202
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Regrowth and rest requirements of northern wheatgrass following defoliation
Degree-days required for standing crop and above-ground net primary production of northern wheatgrass (Agropyron dasystachyum [Hook.] Scribn., syn. Elymus lanceolatus [Scrib. &Smith] Gould) mowed to a 5-cm stubble to recover to levels similar to an unmowed control were determined in southwestern Saskatchewan. Nine, single mowing treatments and an unmowed control were established from early May through late August in 1991 and 1992 on a clayey range site at 2 locations. Green and dead phytomass and above-ground net primary production were determined for 2 to 3 years following mowing. Degree-days required for recovery of green and dead standing phytomass on mowed plots decreased linearly and were highly correlated (r2 = 0.64 to 0.99) with the number of days plots were mowed after 1 May. Regardless of mowing date, green phytomass did not recover to control levels the year of mowing. Each day mowing was delayed past 1 May reduced the number of degree-days required for total recovery of green phytomass on mowed plots by 15.7 in 1991 and 17.7 in 1992. Degree-days required for recovery of standing dead on mowed plots were reduced 17.6 in 1991 and 15.8 in 1992. Degree-days required for recovery of above-ground net primary production declined linearly (r2 = 0.67 and 0.99) as mowing was delayed after 1 May. More degree-days were required for the 1991 than 1992 plots. At least 2 and sometimes 3 growing seasons were required to accumulate enough degree-days to allow full recovery of green and standing dead phytomass and above-ground net primary production on mowed plots. For optimum sustained production, a grazing system should be used on northern wheatgrass-dominated rangeland with a 2 year rest period applied to paddocks after grazing.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202
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