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111.
In this paper we present a novel expansion of the problem of optimal reserve site selection over time. We explore a case where areas with valuable biodiversity cannot all be protected immediately due to budget restrictions and there is a probability of species extinction on reserved as well as non-reserved sites. Add to this the risk of land-use conversion facing all non-reserved areas. We furthermore introduce a new type of control by making the planning authorities have the option to sell reserved land on which biodiversity value has decreased. We formulate and solve this problem through stochastic dynamic integer-programming. The current study shows that, due to the dynamic and stochastic nature of biodiversity evolution, the inclusion of a swapping option may increase overall efficiency. Finally, we test a number of decision criteria (heuristics) to investigate alternatives to the cumbersome task of determining the true optimum. 相似文献
112.
Alexandra F. Belotta Monique N. Mayer Cheryl L. Waldner Kate Robinson Narinder Sidhu James Carmalt Chris D. Bell Niels K. Koehncke 《The Canadian veterinary journal. La revue veterinaire canadienne》2021,62(4):349
The objective of this study was to report observed radiation safety practices among equine workers using portable X-ray units at 3 veterinary practices in Canada. Practice 1 was comprised of equine field service workers from an academic institution, whereas Practices 2 and 3 were comprised of workers from private equine referral practices. Out of 2969 exposure-worker observations, protective aprons were worn for > 99% (2968/2969), thyroid shields for 87% (2584/2969), and eyeglasses for 10% (310/2969). The cassette was held by hand for 97% (1078/1114) of observations, and the X-ray unit was held by hand for 100% (1293/1293) of observations. Gloves were used for 54% (606/1114) and < 1% (5/1293) of observations involving cassette holders and X-ray tube operators, respectively. Use of gloves was more frequent among technologists than DVMs (P = 0.004), and among workers in Practices 1 and 3 than in Practice 2 (P < 0.001). In conclusion, given that workers commonly hold cassettes and X-ray tubes by hand, improvement in shielding use is needed. Consideration should be given to specific behavior recommendations in radiation regulations. 相似文献
113.
Janet E. Foley Jean-Martin Lapointe Philip Koblik Amy Poland Niels C. Pedersen 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1998,12(6):415-423
Feline infectious peritonitis (FIP) is a fatal Arthus-type immune response of cats to infection with FIP virus, a mutant of the ubiquitous feline enteric coronavirus (FECV). The disease may occur systemically or in any single organ system, and primary neurologic disease is a common subset of such manifestations. We examined 16 domestic cats with clinical neurologic FIP and 8 control cats with nonneurologic FIP, with the intention of identifying the ante-and postmortem diagnostic tests that most contribute to accurate diagnosis. Of the 16 cats with neurologic FIP, 15 were less than 2 years of age and all 16 originated from large multiplecat households. The most useful antemortem indicators of disease were positive anti-coronavirus IgG titer in cerebrospinal fluid, high serum total protein concentration, and findings on magnetic resonance imaging suggesting periventricular contrast enhancement, ventricular dilatation, and hydrocephalus. Postmortem diagnosis was facilitated by FIP monoclonal antibody staining of affected tissue and coronavirus-specific polymerase chain reaction. Most cats with neurologic and ocular forms of FIP had patchy, focal lesions, suggesting that recently developed technologies described in this report may be useful for evaluation of cats with suspected FIP. 相似文献
114.
In 2004,five veterinarians examined 283 dairy cows from four Danish dairy herds and independently assigned scores for the clinical signs lameness, hock lesions and other cutaneous lesions to each cow using a clinical protocol. We evaluated the inter-observer and the intra-observer agreement using prevalence-adjusted, bias-adjusted kappa (PABAK). We chose two different cut-offs between the ordinal scores for classifying cows as healthy or diseased for each of the clinical signs, and we compared the ability of the observers to discriminate between healthy and diseased cows for the two cut-offs. Without any formal training of the observers we found PABAK in the range 0.36-0.88 and we concluded that the choice of cut-off had an effect on the observed agreement among the observers. 相似文献
115.
Niels Strange Ida Theilade So Thea Arvid Sloth Finn Helles 《Biological conservation》2007,137(2):223-236
Cambodia forms part of the Indo-Burma hotspot. Its extent of biodiversity, however, is subject to considerable uncertainty, as there has been little systematic collection of flora and fauna. During the Khmer Rouge regime institutions were banned, academics were prosecuted and written documentation systematically destroyed. Compared with neighbouring countries Cambodia has a low population density and relatively large natural areas that are still intact. However, deforestation is expanding rapidly and a significant but un-estimated area of forest has been degraded by development of agro-industries, encroachment, illegal logging, over-harvesting and forest fire as well as the use of chemicals during war. The purpose of the paper is to: (i) apply reserve selection methods to design more robust conservation networks when knowledge of species occurrence is incomplete and habitat is threatened, and (ii) evaluate the usefulness of systematic conservation planning in a developing country where data are limited and institutions for implementation are weak. This study investigates the performance of four non-probabilistic strategies: (i) a so-called ‘rule of thumb’, (ii) hotspot, (iii) minimum cost representation, and (iv) maximum coverage; and one probabilistic design strategy, i.e. maximum expected coverage. The maximum expected coverage approach is between 15% and 24% more efficient than the non-probabilistic strategies. Finally, the relevance of such tools to real-world conservation planning in Cambodia is investigated. By incorporating experts in the generation of data, running the models and setting up premises, they acknowledge that it is possible to contribute to more systematic conservation planning in developing countries. 相似文献
116.
Lucas M. Hart Niels Lorenzen Katja Einer-Jensen Maureen K. Purcell Paul K. Hershberger 《Journal of aquatic animal health》2013,25(3):121-128
AbstractHomologous and heterologous (genogroup Ia) DNA vaccines against viral hemorrhagic septicemia virus (genogroup IVa) conferred partial protection in Pacific Herring Clupea pallasii. Early protection at 2 weeks postvaccination (PV) was low and occurred only at an elevated temperature (12.6°C, 189 degree days), where the relative percent survival following viral exposure was similar for the two vaccines (IVa and Ia) and higher than that of negative controls at the same temperature. Late protection at 10 weeks PV was induced by both vaccines but was higher with the homologous vaccine at both 9.0°C and 12.6°C. Virus neutralization titers were detected among 55% of all vaccinated fish at 10 weeks PV. The results suggest that the immune response profile triggered by DNA vaccination of herring was similar to that reported for Rainbow Trout Oncorhynchus mykiss by Lorenzen and LaPatra in 2005, who found interferon responses in the early days PV and the transition to adaptive response later. However, the protective effect was far less prominent in herring, possibly reflecting different physiologies or adaptations of the two fish species.Received August 1, 2016; accepted March 10, 2017 Published online July 11, 2017 相似文献
117.
George Matusick Katinka X. Ruthrof Niels C. Brouwers Bernard Dell Giles St. J. Hardy 《European Journal of Forest Research》2013,132(3):497-510
Drought and heat-induced forest dieback and mortality are emerging global concerns. Although Mediterranean-type forest (MTF) ecosystems are considered to be resilient to drought and other disturbances, we observed a sudden and unprecedented forest collapse in a MTF in Western Australia corresponding with record dry and heat conditions in 2010/2011. An aerial survey and subsequent field investigation were undertaken to examine: the incidence and severity of canopy dieback and stem mortality, associations between canopy health and stand-related factors as well as tree species response. Canopy mortality was found to be concentrated in distinct patches, representing 1.5 % of the aerial sample (1,350 ha). Within these patches, 74 % of all measured stems (>1 cm DBHOB) had dying or recently killed crowns, leading to 26 % stem mortality six months following the collapse. Patches of canopy collapse were more densely stocked with the dominant species, Eucalyptus marginata, and lacked the prominent midstorey species Banksia grandis, compared to the surrounding forest. A differential response to the disturbance was observed among co-occurring tree species, which suggests contrasting strategies for coping with extreme water stress. These results suggest that MTFs, once thought to be resilient to climate change, are susceptible to sudden and severe forest collapse when key thresholds have been reached. 相似文献
118.
Teresa Pires-dos-Santos Magne Bisgaard Niels Kyvsgaard Henrik Christensen 《Veterinary microbiology》2014
A collection of 46 avian pathogenic Escherichia coli (APEC) isolates was examined for the presence of mutators by determining the rate of mutation to rifampicin resistance. The collection included 34 E. coli isolates obtained in pure culture from chronic lesions of salpingitis and peritonitis in 34 broiler breeders, of which 12 were associated with the development of secondary septicemia. Twelve additional isolates were obtained from a clonal outbreak (ST95) of E. coli peritonitis syndrome (EPS), the lesions of which changed gradually over time into a subacute/chronic form. The hypothesis of the present study was that mutation rates would be higher for chronic infection isolates than for isolates from acute infections/exacerbations. The distribution of mutation rates followed a pattern similar to that found for other clinical isolates of E. coli, with a modal/median value of 1.47 × 10−8. Of the 46 isolates, 24% (n = 11) were weakly hypermutable (2.00 × 10−8 ≤ μ < 2.00 × 10−7), however, no strong mutators were detected (μ ≥ 2.00 × 10−7). Chronic salpingitis isolates had the highest proportion (45%, P = 0.001) of weak mutators and also, significantly higher mutation rates (P = 0.003) compared to isolates that caused septicemia (4%). In addition, mutation rates were significantly lower among ST95 isolates (P < 0.0005), and among isolates from the same clonal group as ST95 (P = 0.027), when compared to isolates from other groups. Although a clear association with the time phase of infection (as lesions of EPS became more chronic) could not be observed (ρ = 0.523, P = 0.081), a higher frequency of weak mutators among chronic infection isolates suggests that increased mutation rates play a role in adaptation of APEC to long-term persistence in an infected host environment. 相似文献
119.
J. D. Keyyu A. A. Kassuku N. C. Kyvsgaard J. Monrad 《Veterinary research communications》2009,33(6):555-565
A longitudinal demonstration project was carried out in 2005/2006 for thirteen months to determine the effectiveness of a
strategic community-based worm control (CBWC) programme in the control of gastrointestinal (GI) nematodes and Fasciola gigantica in cattle. Two villages namely, a CBWC village (Ilula-Masukanzi) and a village without CBWC (Kilolo-Luganga) were randomly
selected in Kilolo district, Iringa region of Tanzania. Animals in both villages were under the traditional management system
and used the village communal grazing area. At the village with CBWC, 60 zebu cattle (6–18 months old) from 10 farms in the
village were selected and ear tagged for monthly sampling and weghing. A strategic CBWC programme was instituted whereby all
animals in the village (tagged and non-tagged) were treated with albendazole 10% drench at 10 mg/kg four times a year e.g.
middle of the rainy season (February), end of the rainy season (May), middle of the dry season (September) and late dry/early
rainy season (December). In the village without CBWC, 68 zebu cattle (6–18 months old) from 11 farms in the village were selected
and tagged for monthly sampling and weighing. Farmers in the village without CBWC were allowed to continue with their normal
management practices including anthelmintic treatments. Faecal and blood samples from tagged animals and pasture samples from
communal grazing areas were collected on monthly basis for 13 months. Results showed that strategic CBWC programme was highly
effective in reducing faecal egg counts (FEC) and the proportion of animals passing Fasciola eggs in faeces. The strategic CBWC significantly reduced FEC of animals by an average of 60% compared to animals at the village
without CBWC (P < 0.01). Four strategic CBWC treatments per year significantly reduced the proportion of animals passing Fasciola eggs in faeces by an average of 82.5% compared to animals at the village without CBWC (P < 0.05). From commencement to the
end of the trial, animals at the village with CBWC significantly outgained animals at the village without CBWC by an average
of 13.9 kg per year (P < .05). It is concluded that strategic CBWC programme was highly effective in reducing FEC, reducing
the proportion of animals passing Fasciola eggs in faeces and improved weight gain in animals. 相似文献
120.
Sahithya Phani Babu Vemulapalli Juan Carlos Fuentes-Monteverde Niels Karschin Tatsuo Oji Christian Griesinger Klaus Wolkenstein 《Marine drugs》2021,19(8)
Two new water-soluble phenanthroperylene quinones, gymnochrome H (2) and monosulfated gymnochrome A (3), as well as the known compounds gymnochrome A (4) and monosulfated gymnochrome D (5) were isolated from the deep-sea crinoid Hypalocrinus naresianus, which had been collected in the deep sea of Japan. The structures of the compounds were elucidated by spectroscopic analysis including HRMS, 1D 1H and 13C NMR, and 2D NMR. The absolute configuration was determined by ECD spectroscopy, analysis of J-couplings and ROE contacts, and DFT calculations. The configuration of the axial chirality of all isolated phenanthroperylene quinones (2–5) was determined to be (P). For gymnochrome H (2) and monosulfated gymnochrome A (3), a (2′S,2″R) configuration was determined, whereas for monosulfated gymnochrome D (5) a (2′R,2″R), configuration was determined. Acetylated quinones are unusual among natural products from an echinoderm and gymnochrome H (2) together with the recently reported gymnochrome G (1) represent the first isolated acetylated phenanthroperylene quinones. 相似文献