Tactical management of pasture fallows in Western Australian cropping systems     

Graeme J. Doole  Ellen Weetman 《Agricultural Systems》2009,102(1-3):24-32

Agricultural systems in the Western Australian wheatbelt are increasingly moving towards specialist crop production due to elevated cereal prices, depressed markets for livestock products, and ongoing labour scarcity. However, the profitability of crop-only farms is threatened by increasing levels of herbicide resistance and declining soil fertility. This study determines the value of ungrazed pasture fallows grown tactically between crop phases to address these agronomic constraints. A novel metaheuristic optimisation technique, compressed annealing, is used to determine profitable flexible land-use sequences in a complex simulation model. Tactical use of single-year, ungrazed pasture phases is found to be more valuable than the use of break crops in crop-only systems. In contrast to previous analysis, it is identified that rotation of short periods of crop and pasture is more profitable than extended phases of both. Effective weed control without dependence on selective herbicides is the key agronomic characteristic determining the value of intermittent pasture phases. Accordingly, the number of single-year pasture phases employed in a sequence should increase with the severity of herbicide resistance. Compressed annealing is shown to be a practical method of identifying profitable land-use sequences that respond to information that unfolds dynamically.  相似文献   

Monitoring shallow methane‐derived authigenic carbonate: Insights from a UK Marine Protected Area     

Tamsyn Noble‐James  Alan Judd  Markus Diesing  David Clare  Andrew Eggett  Briony Silburn  Graeme Duncan 《水产资源保护:海洋与淡水生态系统》2020,30(5):959-976

1. Methane‐derived authigenic carbonate (MDAC) is a biogenic rocky substrate formed by microbial assemblages below the seabed. It performs important ecosystem functions, including the provision of reef‐like habitats on soft sediments and the sequestration of carbon.
2. The protection of MDAC is limited at the global scale; however, 27 marine protected areas (MPAs) have been designated in European waters for ‘cold seep’ MDAC, mainly in shallow waters (<200 m). Few studies have been conducted on these habitats from a conservation perspective.
3. The effective management of MDAC structures requires an understanding of their ecology and physical characteristics in a healthy condition. This is best achieved using a multidisciplinary approach to provide evidence on predefined aspects of MDAC structures, termed feature attributes, which can be assessed to determine habitat condition over time.
4. This article presents the first UK effort to develop a multidisciplinary approach to monitoring shallow MDAC feature attributes, using the Croker Carbonate Slabs Special Area of Conservation (SAC) as a case study. A range of remote and physical survey methods were used to characterize the MDAC and associated relatively unimpacted and healthy biological communities.
5. The data confirm that the SAC contains the largest known area of shallow MDAC in European waters, that methane release is ongoing, and that MDAC is still likely to be forming. Specialized chemoautotrophic fauna were not recorded, possibly due to the dominance of fauna that derive carbon (ultimately) from photosynthesis. Five epifaunal taxa were found to be associated with MDAC, but not with the surrounding sediments.
6. The broad multidisciplinary survey allowed a detailed characterization of shallow MDAC but was resource intensive. We recommend a low‐resource monitoring strategy to deliver cost‐effective and robust evidence for condition assessment and suggest further studies to contextualize future interpretations of change.

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John Beaupert Smith     

Graeme H McIntosh 《Australian veterinary journal》1993,70(4):159-160

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Global biodiversity scenarios and landscape ecology   总被引：1，自引：0，他引：1  

Graeme S. Cumming 《Landscape Ecology》2007,22(5):671-685

The composition of ecological communities is both cause and consequence of landscape pattern. Predicting biodiversity change involves understanding not only ecology and evolution, but also complex changes in human societies and economies. Scenarios offer a less rigid approach to thinking about biodiversity change in a policy and management context. They shift the focus of research and management from making singular predictions and developing single ‘best’ strategies to exploring uncertainties and assessing the outcomes of alternative policies. The four Millennium Ecosystem Assessment (MA) biodiversity scenarios illustrate current approaches to biodiversity estimation in global scenarios. The MA biodiversity scenarios are built around the species–area relationship and the magnitudes of a few area-dependent processes such as nitrogen deposition and climate change. Some of the most obvious landscape-related omissions from the MA scenarios are pattern-process feedbacks, scale dependencies, and the role of landscape configuration. While the MA has set a new standard for biodiversity scenarios, future exercises would benefit from a more multi-scale and more mechanistic framework. I use examples from research on the landscape ecology and biogeography of African ticks to illustrate how a hypothesis-based approach can be used to analyse the multi-scale, multi-level drivers of change in patterns of species occurrences. Two of the most important challenges for the future development of both landscape ecology and biodiversity scenarios are to become more mechanistic (less pattern-based) and more general (applicable across different landscapes).  相似文献   

Feline pyothorax: a retrospective study of 27 cases in Australia     

Barrs VR  Allan GS  Martin P  Beatty JA  Malik R 《Journal of Feline Medicine and Surgery》2005,7(4):211-222

Pyothorax was diagnosed in 27 cats between 1983 and 2002. In 21 (78%) of the cases, pleural fluid culture and/or cytology was consistent with a mixed anaerobic bacterial infection of oropharyngeal origin. In six cases (22%), infection was caused by unusual pathogens or pathogens of non-oropharyngeal origin, including a Mycoplasma species, Cryptococcus gattii, Escherichia coli, Salmonella typhimurium and Staphylococcus aureus. The overall mortality rate was 22%. Treatment was successful in 18 of 19 cases (95%) where closed thoracostomy tubes were inserted. One case resolved only after thoracotomy. Actinomyces species were isolated in three cases and in contrast to dogs where thoracotomy is recommended, they were resolved with tube thoracostomy. Mechanical complications occurred in 58% of the cats with indwelling chest tubes. Probable mechanisms of pleural space infection were identified in 18 cats (67%) including haematogenous infection (n=1), direct inoculation of bacteria into the pleural space (n=1), intrathoracic oesophageal rupture (n=1) and parapneumonic extension of infection (n=15; 56%). Of the latter, perioperative aspiration was suspected in two cats, parasitic migration in two and antecedent upper respiratory tract infection was implicated in seven. Parapneumonic spread of infection after colonisation and invasion of lung tissue by oropharyngeal flora appears to be the most frequent cause of feline anaerobic polymicrobial pyothorax and contests the widespread belief that direct inoculation of pleural cavity by bite wounds is more common.  相似文献   

The use and assessment of ketamine-medetomidine-butorphanol combinations for field anaesthesia in wild European badgers (Meles meles)     

McLaren GW  Thornton PD  Newman C  Buesching CD  Baker SE  Mathews F  Macdonald DW 《Veterinary anaesthesia and analgesia》2005,32(6):367-372

OBJECTIVE: To evaluate the effectiveness of four ketamine-based anaesthetics in badgers using a quantitative anaesthesia assessment technique. STUDY DESIGN: Prospective randomized 'blinded' experimental trial. METHODS: The quality of induction, of anaesthesia (at 5-minute intervals) and of recovery were assessed in 93 badgers, given either one of three ketamine (K)-medetomidine (M)-butorphanol (B) combinations: group A - M K B at 20/40/80 microg kg(-1); group B - M K B at 20/40/60 microg kg(-1); and group C - M K B at 20/60/40 microg kg(-1), or ketamine (K) alone at 2 mg kg(-1) (group D). The assessor was ignorant of the combination administered. Physiological variables (heart and respiratory rates and rectal temperature) were measured at 5-minute intervals during anaesthesia. Gingival mucus membrane colour was also recorded. RESULTS: Induction to anaesthesia was most rapid with ketamine (2 mg kg(-1)) although induction quality did not differ between techniques. Ketamine used alone gave the poorest score for anaesthesia quality. Heart rate (HR) and scores for gingival mucus membrane colour were higher in animals anaesthetized with ketamine alone. Rectal temperature did not differ significantly between the techniques at any time during anaesthesia. Ketamine used alone produced the poorest quality of recovery. CONCLUSION AND CLINICAL RELEVANCE: The M-K-B combinations investigated overcame several side effects associated with ketamine anaesthesia, but at the expense of more variable induction times, lower HRs, and poorer mucus membrane coloration.  相似文献   

IMAGING DIAGNOSIS—OCCIPITOATLANTOAXIAL MALFORMATION IN A MINIATURE HORSE FOAL     

Diana S.  Rosenstein  DVM  MS  Harold C.  Schott II  DVMP hD  Russ L.  Stickle  DVM 《Veterinary radiology & ultrasound》2000,41(3):218-219

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Heat shock protein HSP90 immunoexpression in equine endometrium during oestrus,dioestrus and anoestrus     

Ana Camacho Benítez  Rossana Vasconcellos  Paula Lombide  Helen Viotti  William Pérez  Nicolás Cazales  Daniel Cavestany  Graeme B. Martin  Graciela Pedrana 《Anatomia, histologia, embryologia》2021,50(1):50-57

Heat shock proteins play a crucial role in cellular development, proliferation, differentiation and apoptosis. Heat shock protein 90 (HSP90) has been localised in the human endometrium, where its immunoexpression changes during the menstrual cycle. Similar studies have not been done for the equid species, so the present study aimed to describe endometrial HSP90 immunoexpression in mare endometrium. Endometrial biopsies were formalin-fixed and paraffin-embedded, and sections were stained with haematoxylin–eosin in preparation for HSP90 immunohistochemistry. Immunostaining and morphometric analyses were performed on the epithelial lining, endometrial glands and connective stroma during oestrus, dioestrus phase and anoestrus period (n = 7 per phase or period). Immunoexpression was localised in the basal region of the epithelial cells lining the lumen. Immunoexpression was greater during oestrus than during either dioestrus or anoestrus. During anoestrus, there was little immunostaining in the endometrium, suggesting that HSP90 is involved in the functional modulation of sex steroid receptors in cyclic mares. Indeed, the function of HSP90 as a chaperone in the folding of proteins, such as steroid receptors, might explain the greater intensity of immunostaining during the oestrus and dioestrus phases, compared the anoestrus period. We conclude that, in the mare, HSP90 plays a role in endometrial function and that further studies are needed to test whether it is important in pathological conditions as endometritis.  相似文献   

Variation in developmental patterns of wild barley (Hordeum spontaneum L.) and cultivated barley (H. vulgare L.)     

Graeme C. Kernich  Gerald M. Halloran  Raymond G. Flood 《Euphytica》1995,82(2):105-115

Summary Six wild barley (Hordeum spontaneum) accessions, from a diverse range of habitats, and two spring-cultivated barleys, were examined for variation in durations of development phases. The durations of the leaf initiation and spikelet initiation phases were longer and spikelet growth phases shorter, in wild than in cultivated barley. Across all wild and cultivated barleys the rate and duration of spikelet initiation were negatively correlated, but neither was related to the number of spikelets per spike. The number of spikelets was positively correlated with the number of leaves and the ratio of the number of spikelets to the number of leaves declined with increasing time to anthesis, indicating that each successive leaf was associated with a diminishing increase in the number of spikelets. The duration of culm elongation and final culm length were shorter in accessions of cultivated barley compared with wild barley. This paper also discusses the feasibility for increasing the number of spikelets per spike through breeding for genetic changes in lengths of pre-anthesis phases of development.Abbreviations ANOVA Analysis of variance - HV Hordeum vulgare - CE Culm elongation - DR Double ridge - HS Hordeum spontaneu - ° Cd Degree days  相似文献   

Uptake of pet insurance     

King R 《The Veterinary record》2011,168(23):624

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