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61.
Hunter J. Piegols Brittany E. Abrams Janis M. Lapsley Megan T. Cray Josephine A. Dornbusch Christina Murphy Brandan G. Wustefeld-Janssens Carlos H. Souza Marine Traverson Pierre Amsellem Elroy Williams Owen T. Skinner Julius M. Liptak Julie A. Stephens Laura E. Selmic 《Veterinary and comparative oncology》2023,21(4):673-684
Adrenalectomies for canine adrenal tumours are associated with peri-operative morbidity and mortality. Objectives of this study included assessing the prognostic value of tumour- or surgery-related variables in predicting peri-operative mortality and overall survival in dogs undergoing adrenalectomies for primary adrenal tumours as well as pre-treatment with phenoxybenzamine on survival to discharge with pheochromocytomas specifically. A multi-institutional retrospective cohort study was performed across nine institutions. Electronic medical record searches identified 302 dogs which met the inclusion criteria. Data collected included dog-related, tumour-related, treatment-related, surgery-related, and outcome variables. Univariate and multivariable logistic regression and cox proportional hazards models were used to identify variables associated with death prior to discharge and tumour-related survival. Overall, 87% of dogs survived to discharge with a tumour-related survival time of 3.96 years. Post-operative complications were reported in 25%. Increased surgical time (p = 0.002) and pre-surgical medical treatment other than phenoxybenzamine (p = 0.024) were significantly associated with increased peri-operative mortality while ureteronephrectomy (p = 0.021), post-operative pancreatitis (p = 0.025), and post-operative aspiration pneumonia (p < 0.001) were significantly associated with decreased overall survival. Phenoxybenzamine pretreatment had no effect on peri-operative mortality. Thirty-seven of 45 (82%) dogs with pheochromocytomas not pretreated survived to discharge, and 50 of 59 (85%) dogs with pheochromocytomas pretreated with phenoxybenzamine survived to discharge (p = 0.730). This study provides information on risk factors for death prior to discharge and tumour-related survival that may help guide clinical management and owner expectations. In addition, the study findings challenge the previously reported benefit of phenoxybenzamine for pretreatment of dogs undergoing adrenalectomies for pheochromocytomas. 相似文献
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64.
The organization of two farmer-managed irrigation systems in the western hills of Nepal is described by examining the ways in which the activities of water allocation, water distribution, maintenance, and resource mobilization are performed. Due to the topography and environment, these two organizations are structured primarily to mobilize the large amount of labor required for maintenance of the intake and canal. Both organizations precisely define each member's water allocation. In one system, water is allocated in proportion to the area of an individual's land holding, while in the other water allocation is by purchased shares. These two cases were used to analyze the importance of the principle of water allocation for expansion of area irrigated and equity of access to irrigation. Evidence from the two systems shows that in this hill environment water allocation by purchased shares provides the individual incentive and an organizational mechanism for efficient development of irrigation resources. Expansion of area irrigated and equity of access to irrigation were found to be greater in the system which allocates water by purchased shares than where water was allocated in proportion to area irrigated. 相似文献
65.
The impact of increasing farm size and mechanization on rural income and rice production in Zhejiang province,China 总被引:1,自引:0,他引:1
M. Marrit Van den Berg Huib Hengsdijk Joost Wolf Martin K. Van Ittersum Wang Guanghuo Reimund P. Roetter 《Agricultural Systems》2007
Economic growth in China’s agricultural sector lags behind growth in industry and services, creating an ever widening rural–urban income gap. Development of the non-agricultural sectors offers new opportunities for farmers in China’s more advanced provinces such as Zhejiang. Increased income in the urban sector creates markets for new products, and migrating farmers rent their land to those staying. Until now, the prevailing rice-based systems have been managed mainly using manual labour and animal traction, but the larger farms resulting from migration may facilitate, or even require mechanization. In this study, we use a simulation model of the farm household to analyse the effects of increasing farm size and the transition from rice to vegetable production, while also studying the effects of mechanization. 相似文献
66.
Can carbon sequestration markets benefit low-income producers in semi-arid Africa? Potentials and challenges 总被引:1,自引:0,他引:1
The Clean Development Mechanism (CDM) of the Kyoto Protocol of the United Nations Framework Convention on Climate Change allows a country that emits C above agreed-upon limits to purchase C offsets from an entity that uses biological means to absorb or reduce greenhouse emissions. The CDM is currently offered for afforestation and reforestation projects, but may apply subsequently to sequestration in agricultural soils. Additionally, markets outside of the Protocol are developing for soil C sequestration. 相似文献
67.
Lázaro-Lobo Adrián Ramirez-Reyes Carlos Lucardi Rima D. Ervin Gary N. 《Landscape Ecology》2021,36(12):3539-3555
Landscape Ecology - Invasive plants cause significant impacts in forested areas throughout the world. However, little is known about the relative importance of environmental drivers on the... 相似文献
68.
Miriam S Martin Michael D Kleinhenz Lily N Edwards-Callaway Terry E Engle Octavio Guimaraes David W Schafer Shawnee R Montgomery Andrew K Curtis Mikaela M Weeder Devin R Jacobs Johann F Coetzee 《Journal of animal science》2022,100(3)
Hot-iron branding uses thermal injury to permanently identify cattle causing painful tissue damage. The primary objective was to examine the physiological and behavioral effects of oral meloxicam (MEL), compared to a control, administered at the time of hot-iron branding in Angus and Hereford steers and heifers. The secondary objectives were to investigate breed and sex effects on pain biomarkers. A total of 70 yearlings, consisting of 35 heifers and 35 steers (Angus, Hereford, or Angus × Hereford), were enrolled in the study. Animals were blocked by sex, randomized across weight, and assigned to receive MEL (1 mg/kg) or a placebo (CON). Biomarkers were assessed for 48 h after branding and included infrared thermography (IRT), mechanical nociceptive threshold (MNT), accelerometry and a visual analog scale (VAS), and serum cortisol and prostaglandin E2 metabolites (PGEM). Wound healing was assessed for 12 wk. Hair samples to quantify cortisol levels were taken prior to and 30 d post-branding. Responses were analyzed using repeated measures with calf nested in treatment as a random effect, and treatment, time, treatment by time interaction, breed, and sex as fixed effects. There was a treatment by time interaction for PGEM (P < 0.01) with MEL having lower values than CON at 6, 24, and 48 h (MEL: 18.34 ± 3.52, 19.61 ± 3.48, and 22.24 ± 3.48 pg/mL, respectively; CON: 32.57 ± 3.58, 37.00 ± 3.52, and 33.07 ± 3.48 pg/mL; P < 0.01). MEL showed less of a difference in maximum IRT values between the branded (2.27 ± 0.29 °C) and control site (3.15 ± 0.29 °C; P < 0.01). MEL took fewer lying bouts at 0–12 h (4.91 bouts ± 0.56) compared with CON (6.87 bouts ± 0.55; P < 0.01). Compared with Hereford calves, Angus calves exhibited greater serum but lower hair cortisol, greater PGEM, more lying bouts, and less healed wound scores at 3, 4, and 5 wk. Compared with heifers, steers exhibited lower PGEM, lower branding site and ocular IRT, higher MNT, and lower plasma meloxicam levels. Steers spent more time lying, took more lying bouts and had greater VAS pain, and more healed wound scores at 5 wk than heifers. Meloxicam administration at branding reduced branding and control site temperature differences and reduced lying bouts for the first 12 h. Breed and sex effects were observed across many biomarkers. Changes from baseline values for IRT, MNT, lying time, step count, VAS pain, and wound scoring all support that branding cattle is painful. 相似文献
69.
Sediment production from unpaved roads in a sub-tropical dry setting — Southwestern Puerto Rico 总被引:1,自引:0,他引:1
The threat imposed by increased sediment loading rates ranks among the most important stressors affecting coral reef ecosystems worldwide. This study represents an effort to quantify the effects of unpaved roads on erosion rates in a dry sub-tropical area of Puerto Rico and is intended to aid in developing scientifically-based erosion mitigation strategies. Hence, the specific objectives of this study were to: (1) measure sediment production rates from unpaved roads; (2) evaluate the effect of precipitation, rainfall erosivity, slope, plot length, and vegetation cover on sediment production rates; and (3) compare measured sediment production rates to published surface erosion data from roaded and natural sites in the Eastern Caribbean. Sediment production from nine abandoned road segments with varying slopes and plot lengths were measured with sediment traps in southwestern Puerto Rico from August 2003 to September 2005. 相似文献
70.
Martin Wiesmeier Olivia Kreyling Markus Steffens Philipp Schoenbach Hongwei Wan Martin Gierus Friedhelm Taube Angelika Kölbl Ingrid Kögel‐Knabner 《植物养料与土壤学杂志》2012,175(3):434-442
The assessment of grassland degradation due to overgrazing is a global challenge in semiarid environments. In particular, investigations of beginning steppe degradation after a change or intensification of the land use are needed in order to detect and adjust detrimental land‐use management rapidly and thus prevent severe damages in these sensitive ecosystems. A controlled‐grazing experiment was established in Inner Mongolia (China) in 2005 that included ungrazed (UG) and heavily grazed plots with grazing intensities of 4.5 (HG4.5) and 7.5 (HG7.5) sheep per hectare. Several soil and vegetation parameters were investigated at all sites before the start of the experiment. Topsoil samples were analyzed for soil organic C (SOC), total N (Ntot), total S (Stot), and bulk density (BD). As vegetation parameters, aboveground net primary productivity (ANPP), tiller density (TD), and leaf‐area index (LAI) were determined. After 3 y of the grazing experiment, BD increased and SOC, Ntot, Stot, ANPP, and LAI significantly decreased with increasing grazing intensity. These sensitive parameters can be regarded as early‐warning indicators for degradation of semiarid grasslands. Vegetation parameters were, however, more sensitive not only to grazing but also to temporal variation of precipitation between 2006 and 2008. Contrary, soil parameters were primarily affected by grazing and resistant against climatic variations. The assessment of starting conditions in the study area and the application of defined grazing intensities is essential for the investigation of short‐term degradation in semiarid environments. 相似文献