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Krystyna M. Saunders Andrew Mcminn Donna Roberts Dominic A. Hodgson Henk Heijnis 《水产资源保护:海洋与淡水生态系统》2007,17(1):51-70
- 1. Many coastal lagoons in eastern Australia have changed as a result of recent human activities. However, it is often difficult to determine the extent of change and the ecological implications. A palaeoecological approach allows a quantitative assessment of how an aquatic ecosystem changes and responds to human impacts beyond what is possible with historical data or monitoring programmes.
- 2. Orielton Lagoon (south‐east Tasmania, Australia) is a Ramsar‐listed coastal wetland of international importance for conservation. This study was undertaken at the site to determine whether recent anthropogenic hydrological modifications to the lagoon had influenced its ecology, particularly salinity, and compromised its Ramsar status.
- 3. A diatom–salinity transfer function was constructed from a training data set of 96 diatom taxa from 34 sampling sites in 19 lagoons along the east coast of Tasmania.
- 4. The salinity of Orielton Lagoon has changed in response to a causeway constructed across its mouth, which has transformed the lagoon from an open marine environment to an enclosed, virtually stagnant, brackish water body.
- 5. These changes have compromised the protected coastal wetland status of Orielton Lagoon. Environmental remediation attempts have since partially restored the natural hydrology of the lagoon and it is now returning towards the state it was in prior to causeway construction.
- 6. A palaeoecological approach using diatoms was found to be successful in reconstructing recent salinity changes and investigating human impacts on Orielton Lagoon over the last 50–55 years.
4.
Sugar concentration in nectar: a quantitative metric of crop attractiveness for refined pollinator risk assessments
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Loren D Knopper Tereza Dan Dominic D Reisig Josephine D Johnson Lisa M Bowers 《Pest management science》2016,72(10):1807-1812
Those involved with pollinator risk assessment know that agricultural crops vary in attractiveness to bees. Intuitively, this means that exposure to agricultural pesticides is likely greatest for attractive plants and lowest for unattractive plants. While crop attractiveness in the risk assessment process has been qualitatively remarked on by some authorities, absent is direction on how to refine the process with quantitative metrics of attractiveness. At a high level, attractiveness of crops to bees appears to depend on several key variables, including but not limited to: floral, olfactory, visual and tactile cues; seasonal availability; physical and behavioral characteristics of the bee; plant and nectar rewards. Notwithstanding the complexities and interactions among these variables, sugar content in nectar stands out as a suitable quantitative metric by which to refine pollinator risk assessments for attractiveness. Provided herein is a proposed way to use sugar nectar concentration to adjust the exposure parameter (with what is called a crop attractiveness factor) in the calculation of risk quotients in order to derive crop‐specific tier I assessments. This Perspective is meant to invite discussion on incorporating such changes in the risk assessment process. © 2016 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. 相似文献
5.
Roundworms and flatworms that affect donkeys can cause disease. All common helminth parasites that affect horses also infect donkeys, so animals that co‐graze can act as a source of infection for either species. Of the gastrointestinal nematodes, those belonging to the cyathostomin (small strongyle) group are the most problematic in UK donkeys. Most grazing animals are exposed to these parasites and some animals will be infected all of their lives. Control is threatened by anthelmintic resistance: resistance to all 3 available anthelmintic classes has now been recorded in UK donkeys. The lungworm, Dictyocaulus arnfieldi, is also problematical, particularly when donkeys co‐graze with horses. Mature horses are not permissive hosts to the full life cycle of this parasite, but develop clinical signs on infection. In contrast, donkeys are permissive hosts without displaying overt clinical signs and act as a source of infection to co‐grazing horses. Donkeys are also susceptible to the fluke, Fasciola hepatica. This flatworm can be transmitted, via snails and the environment, from ruminants. As with cyathostomins, anthelmintic resistance is increasing in fluke populations in the UK. A number of the anthelmintic products available for horses do not have a licence for use in donkeys, and this complicates the design of parasite control programmes. As no new equine anthelmintic classes appear to be near market, it is important that the efficacy of currently effective drugs is maintained. It is important that strategies are used that attempt to preserve anthelmintic efficacy. These strategies should be based on the concept that the proportion of worms in a population not exposed to anthelmintic at each treatment act as a source of ‘refugia’. The latter is an important factor in the rate at which resistance develops. Thus, it is imperative that parasite control programmes take into account the need to balance therapy to control helminth‐associated disease with the requirement to preserve anthelmintic effectiveness. 相似文献
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The number of donkeys and mules throughout the world is stable, and awareness of their use and concern for welfare, pain recognition and treatment are receiving increasing veterinary interest. Therefore, accurate information about anaesthesia and analgesia in donkeys and mules is important to ever more equine practitioners. Since donkeys are physiologically and pharmacologically different from horses, knowledge on species specific aspects of anaesthesia and analgesia are very important. Mules combine elements from both donkey and horse backgrounds, leading to great diversity in size, temperament and body type. Physiologically, they seem to resemble horses more than donkeys. This review highlights the current knowledge on various anaesthetic and analgesic approaches in donkeys and mules. There is still much information that is not available about donkeys; in many circumstances, the clinician must use available equine information to treat the patient, while monitoring carefully to observe for differences in response to therapy compared to the horse. 相似文献
7.
Nielsen L Toft N Eckersall PD Mellor DJ Morris JS 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2007,21(6):1231-1236
BACKGROUND: The acute-phase protein C-reactive protein (CRP) is used as a diagnostic and prognostic marker in humans with various neoplasias, including non-Hodgkin's lymphoma. OBJECTIVE: To evaluate if CRP could be used to detect different remission states in dogs with lymphoma. ANIMALS: Twenty-two dogs with untreated multicentric lymphoma. METHODS: Prospective observational study. Blood samples were collected at the time of diagnosis, before each chemotherapy session, and at follow-up visits, resulting in 287 serum samples. RESULTS: Before therapy, a statistically significant majority of the dogs (P = .0019) had CRP concentrations above the reference range (68%, 15/22). After achieving complete remission 90% (18/20) of the dogs had CRP concentrations within the reference range, and the difference in values before and after treatment was statistically significant (P < .001). CRP concentrations of dogs in complete remission (median, 1.91; range, 0.2-103) were significantly different (P = .031) from those of dogs with partial remission (median, 2.48; range, 0-89), stable disease (median, 1.77; range, 1.03-42.65), or progressive disease (median, 8.7; range, 0-82.5). There was profound variation of CRP measurements within each dog. CONCLUSIONS: CRP is useful in determining complete remission status after treatment with cytotoxic drugs. However, the individual variation between dogs means CRP concentration is not sufficiently different in other remission states to permit its use in monitoring progression of the disease. Greater reliability in determining remission status might be achieved by combining CRP concentration with other serum markers. 相似文献
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This paper reports the outcomes of a deliberative workshop comparing land-use plans proposed by land-manager or domain experts with those derived using a computer-based decision support system (DSS). The DSS integrates four main components, a geographic information system, land-use systems simulation models, impact assessments and land-use planning tools. The land-use planning tools draw on the other components to generate and evaluate alternative patterns of land use and management. Since the land-use planning tools are based on multi-objective genetic algorithms (mGAs) it is possible to generate a range of alternative plans that define the structure of the trade-off between the objectives. The workshop tasked the delegates with specifying land-use plans that achieved the best compromise between two objectives known to be non-commensurable and conflicting. The nature of the best compromise was dependent on their individual perspectives. The delegates proposed allocations both as individuals and in researcher-facilitated sub-groups. The mGA allocations were then compared with those derived by delegates and were found to be broadly similar in performance. Differences in the range of allocations considered feasible were explained by the hard and soft constraints on allocations agreed between the delegates and articulated within the workshop process. The hypothesis that part of the difference in performance between the mGA and delegate allocations was due to the delegates blocking together fields with the same land use for convenience of management was proved. The analysis of the group allocations revealed that the decision-making process had failed to improve on the individual allocations. From these results it was concluded that there was a potential role for mGA based land-use planning tools in researching into, and deliberating on, the possible impacts of policy or other factors affecting land-use systems. It was further concluded that the tools should not be used in isolation since there was the need for stake-holder inputs to adequately define the range of feasible and practical land-use plans. 相似文献
9.
This paper presents a scenario-based analysis of the impacts of Common Agricultural Policy (CAP) reform for upland agriculture using a Welsh case-study. Specifically the paper examines the impacts of the introduction of the single-farm payment (SFP), the modulation of direct payments under Pillar I of the CAP and the increase in agri-environment payments under Pillar II. Three enterprises are examined, upland sheep rearing with lamb finishing, spring- and autumn-calving suckler-cattle with calf rearing. These enterprises are modelled under conditions in 2002/3, 2004/5 and for the reformed CAP in 2005/6. To support this analysis a livestock system model (LSM) was implemented. The model assesses alternative management regimen using a flexible state-transition approach. This simplifies the realisation and parameterisation of potentially complex management regimen. The model tracks fodder requirements to achieve targets based on defined diets. The LSM underpins whole-farm analyses of stocking-rates, labour and other resource requirements and net-farm income. From the case study the paper concludes that the impacts of the introduction of the CAP reform on the financial performance of the systems are small but negative (a net reduction of around 5% in support). The larger reduction in direct payments (15–18%) is partially offset by agri-environment measures. The paper concludes that while SFP encourages a more market-oriented outlook, the adaptive capacity within systems as they stand is very limited. There are a range of possible adaptation strategies, but for the uplands the extensification of cattle systems by reducing stock numbers and cutting back on labour seems most probable. 相似文献
10.
Aqueous and ethanol extracts of Acacia pennata (bark), Catunaregam uliginosa (fruit), Diospyros lenceofolia (fruit), and Sapindus mukorossi (fruit) were evaluated as piscicides on the freshwater fish Danio dangila, Danio rerio, and Puntius shalynius, and the air-breathing Heteropneustes fossilis. Catunaregam uliginosa (fruit) possessed relatively higher piscicidal potency followed by Sapindus mukorossi (fruit), Acacia pennata (bark), and lastly Diospyros lanceofolia (fruit). Catunaregam uliginosa can thus be used for eradicating unwanted wild fishes in a short time span at low concentrations so that the health of aquatic environment is maintained. 相似文献