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11.
12.
A passage line of a spontaneous hamster fibrosarcoma is contaminated by the virus. of lymphocytic choriomeningitis. Tumors from animals receiving implants when newborn contain high titers of infectious lymphocytic-choriomeningitis virus and complement-fixing antigen, and hamsters receiving implants when weanlings develop high titers of complement-fixing antibody against lymphocytic-choriomeningitis virus. In contrast with the specific reactions of tumorous hamsters to the initiating virus in virus-induced tumors, the development of complement-fixing antibody to lymphocytic-choriomeningitis virus does not depend on the development of tumors. Infant hamsters bearing the tumor have a generalized subclinical infection and seem able to spread virus to other hamsters and to humans. 相似文献
13.
Sandra A. Loftus BA Jill M. Montplaisir BS Jing-wen Kuo MS Dale P. DeVore PhD 《Journal of Equine Veterinary Science》1988,8(2)
A standardized investigation was conducted to compare the biophysical properties of hyaluronate products used in the treatment of joint dysfunction in horses. Results showed that two of the five products, Hyvisc® and Hylartin®V, contained higher-weight molecular hyaluronate (greater than 1.5×106). Other investigations have shown that higher molecular weight hyaluronate is effective in providing physical resistance to shear, in stimulating endogenous hyaluronate synthesis, and in inhibiting excess cell proliferation which may be associated with synovial pannus formation. It is suggested that the therapeutic benefits of hyaluronate products may be dependent on the molecular size of the hyaluronate molecules. Higher molecular weight hyaluronate products would be expected to be more effective than lower molecular hyaluronate products in providing therapeutic benefits. 相似文献
14.
Nearly 30 years ago, Whitehead and Jarvis and Whitehead et al. postulated an elegant mechanistic explanation for the observed relationship between tree hydraulic structure and function, hypothesizing that structural adjustments promote physiological homeostasis. To date, this framework has been nearly completely overlooked with regard to varying atmospheric carbon dioxide ([CO(2)]). Here, we evaluated Whitehead's hypothesis of leaf water potential (Ψ(l)) homeostasis in faster-growing (Eucalyptus saligna) and slower-growing (Eucalyptus sideroxylon) tree saplings grown under three [CO(2)] (pre-industrial, current and future) and two temperature (ambient and ambient + 4°C) treatments. We tested for relationships between physiological (stomatal conductance and Ψ(l)) and structural (leaf and sapwood areas (A(l), A(s)), height (h), xylem conductivity (k(s))) plant variables as a function of the [CO(2)] and temperature treatments to assess whether structural variables adjusted to maintain physiological homeostasis. Structural components (A(l), A(s), h) generally increased with [CO(2)] or temperature, while g(s) was negatively correlated with [CO(2)]. Contrary to Whitehead's hypothesis, Ψ(l) did not exhibit homeostasis in either species; elevated temperatures were associated with more negative Ψ(l) in faster-growing E. saligna, and less negative Ψ(l) in slower-growing E. sideroxylon. Moreover, individual structural variables were generally uncorrelated with Ψ(l). However, across both species, the integrated hydraulic property of leaf specific hydraulic conductance (K(l)) was positively correlated with an independent calculation of K(l) determined exclusively from leaf physiological variables. These results suggest that physiological homeostasis may not apply to saplings exposed to global change drivers including [CO(2)] and temperature. Nevertheless, Whitehead et al.'s formulation identified K(l) as a sensitive measure of plant structural-physiological co-variation across species. 相似文献
15.
Cristina de Miguel Garcia Luis Campoy Stephen Parry Julia E. Miller Manuel Martin-Flores Robin D. Gleed 《Veterinary anaesthesia and analgesia》2021,48(2):223-229
ObjectiveTo collect data about the current practice of recovering horses from general anesthesia and recovery personnel safety.Study designOnline survey.MethodsAn online questionnaire, including questions on general demographic data, recovery drugs, modality and characteristics of equine recovery and morbidity and mortality, was designed and distributed via e-mail to equine practitioners worldwide.ResultsPractitioners from 22 countries completed 373 questionnaires; 53% of the participants were board-certified equine surgeons, and the remainder were board-certified anesthesiologists (18%), large animal residents (8%), general practitioners (7%), large animal interns (6%), anesthesia residents (4.5%) and veterinary technicians (1.6%). Respondents were employed by academia (58%) or private practice (42%). Of the respondents employed at a university, 93% had a board-certified anesthesiologist on staff compared with 7% of respondents employed at a private practice. Most of the respondents assist horses during recovery, with 23% assisting every recovery and 44% assisting recovery in the majority of cases. Reasons for choosing to assist horses during recovery were: orthopedic procedures (57%), neurological deficits (49%), bad health (47%), history of poor recovery (44%), foals (42%), draft breeds (30%), magnetic resonance imaging (17%) and computed tomography (16%). Unacceptable recoveries were reported by 77% of participants. Commonly reported complications during recovery with any method were: orthopedic injury (66%), myopathy (54%), skin abrasion (53%) and airway obstruction (37%). The incidences of unacceptable quality of recovery (p = 0.09) or personnel injury (p = 0.56) were not different between assisted and nonassisted recoveries; however, more equine fatalities were reported for assisted recoveries (p < 0.006). Practitioners in academia reported more unacceptable recoveries (p < 0.0007) and personnel injuries (p < 0.002) compared with those in private practice.ConclusionsThe method of recovery differs among hospitals. Recovery personnel injuries associated with assisting horses during recovery are an important and previously unreported finding. 相似文献
16.
KENNETH E. BARTELS dvm MS ROGER C. PENWICK VMD LYN J. FREEMAN dvm RICHARD L. LOWERY PhD TOM ALEXANDER BS KENT APPLEMAN BS CATHRYN BLOUNT BS 《Veterinary surgery : VS》1985,14(4):310-318
Eight synthetic casting materials were evaluated with respect to tensile and fatigue strengths, exothermicity (evolution of heat during polymerization), permeability (porosity), radiolucency, and cost. Strength determination for a five-layer sample included measurement of the ultimate load at which a material failed, the ability to absorb energy, and the stiffness a material possessed after application of a cyclic stress. Results indicated that Vet Cast was superior with respect to tensile and fatigue strengths. The exothermic reaction associated with the "curing" or polymerization process was evaluated and not considered excessive although Ultra Cast attained a temperature of 48.0°C and was uncomfortable to handle during application. Permeability was determined. Delta Lite and Hexcelite NS were the most permeable materials and dried more rapidly and thoroughly after immersion than the other casting materials. Hexcelite NS was considered the least radiolucent material and was the most expensive material studied. Each of the synthetic casting materials demonstrated superiority in one or more of the categories tested. No one product demonstrated consistent superiority in criteria appropriate for clinical application. 相似文献
17.
Vincent S. Balilla Julia Anwar-McHenry Mark P. McHenry Riva Marris Parkinson Danilo T. Banal 《Journal of Sustainable Forestry》2013,32(7):687-709
The Aeta Magbukún of Mariveles are one of the least known and researched Indigenous peoples remaining on the fringe of the bay, and within the remaining forests in Bataan province on Luzon Island in the Philippines. This work describes the unique cultural systems and language of the Aeta Magbukún tribe in Biaan, Mariveles, and both the traditional forest resource use and the evolving new subsistence practices developed to adapt to the encroachment of non-Indigenous peoples onto ancestral lands. The Aeta's forest resource use practices are discussed from a sustainable Indigenous development context within unique socioeconomic, cultural, and environmental circumstances in Bataan. 相似文献
18.
We argue that thematic resolution, i.e., the level of categorical detail of a thematic map expressed by the number of classes
included in the map legend, is an inherent component of the scale at which a landscape is analyzed. Changing the number of
classes can change the configuration of the patch mosaic as much as changing the grain does. We address recent calls in this
and other journals to deepen research in this topic. In particular, we report how thematic resolution affects the patchiness
of mosaics representing natural landscapes, which have seldom been studied in this respect. We selected seven 50 × 50 km landscapes
within national parks, each representative of a world biome. We applied an object-based unsupervised classification to Landsat
TM imagery of these landscapes using increasing numbers of classes, between 2 and 50, and derived curves of mean patch size
and patch density for each site. Our results are consistent with previous findings in that the patchiness of output mosaics
increases monotonically with increasing thematic resolution, with a higher rate of increase up to eight classes that declines
until it becomes roughly constant for more than 16 classes. However, this constant rate of increase is still considerable,
meaning that, at least for natural landscapes, there is no threshold beyond which the patch-mosaic model is independent of
the conceptual filter applied. This dependence on human fiat calls for re-thinking the patch-mosaic paradigm. 相似文献
19.
20.
Alternate technologies of compost manufactured from poultry litter (manure) were studied as a means of producing a value-added product for the landscape and nursery industry. Static pile and turned windrow technologies were investigated on a commercial scale with the composting of nearly 300 tons of material. The major difference between the technologies is the amount of energy and labor required. Static pile systems require less energy but more time than windrow turned systems. There was no process advantage found for passively aerated static piles over static piles but costs of passive aeration for pipes and labor were higher than for static piles. Machine turned windrows completed active temperature production within 100 days while portions of both the static and passively aerated piles continued to actively compost past 300 days. Process operational costs and compost quality were similar among the compost methods studied. Production operational cost is driven by the cost of compost ingredients and accounted for 60 to 70% of the cost in the pilot study. Ingredients were poultry litter, wood chips and sawdust. Screened compost was produced at an operational cost of $30 while unscreened compost could be produced for $20 per ton of compost. A production scheme where poultry litter is static pile composted on farms for later transport to regional processing centers appears feasible. This two-part composting procedure will eliminate the transport of raw litter and improve poultry biosecurity. Most likely, a private compost business would provide the expertise, on-farm compost procedures and operate the regional facility. 相似文献