The use of herders’ accounts to map livestock activities across agropastoral landscapes in Semi-Arid Africa     

Turner  Matthew D.  Hiernaux  Pierre 《Landscape Ecology》2002,17(5):367-385

Improved understandings of the agricultural and range ecologies ofsemi-arid Africa require better information on the spatiotemporal distributionof domestic livestock across agropastoral landscapes. An empirical GIS-basedapproach was developed for estimating distributions of herded livestock acrossthree agropastoral territories (around 100 km² each)over a two-year period. Algorithms developed from regression analyses of herdtracking data (with R²s 0.67) are used to transform a morecomprehensive but incomplete set of data generated from herders accounts oftheir herds grazing itineraries (400 herds following 6500 itineraries). Theresulting characterization registers 40 000 days of livestock activitiesacross694 land units (averaging 70 ha) over the study period. This studydemonstrates that rural producers knowledge of their daily extractionpracticescan be translated to fine-grained characterizations of extraction densitiesacross mixed landscapes. The spatiotemporal distribution of livestock that isrevealed by this approach diverges strongly from that predicted bycommonly-usedpoint-diffusion estimation procedures. Instead, the distribution reflects localpatterns of land use, topography, vegetation, settlements, and water points.Grazing and nongrazing times spent in land units are not spatially correlatedand the seasonality of grazing pressure is spatially variable. Therefore, theecological impacts of livestock grazing are spatially variable at fine scalesand there is a significant potential for livestock-mediated nutrient transfersacross agropastoral landscapes. The georeferenced data produced by thisapproachnot only will help evaluate the impact and sustainability of differentmanagement practices but also provides a strong empirical base for improvedspatial modeling of herded livestock.This revised version was published online in May 2005 with corrections to the Cover Date.  相似文献   

Angiographic classification of patent ductus arteriosus morphology in the dog   总被引：1，自引：1，他引：1  

Matthew W. Miller DVM  Dipl ACVIM  Sonya G. Gordon DVM  Dipl ACVIM  Ashley B. Saunders DVM  Dipl ACVIM  Wendy G. Arsenault DVM  Dipl ACVIM  Kathryn M. Meurs DVM  Dipl ACVIM  Linda B. Lehmkuhl DVM  Dipl ACVIM  John D. Bonagura DVM  Dipl ACVIM  Philip R. Fox DVM  Dipl ACVIM  Dipl ECVIM 《Journal of Veterinary Cardiology》2006,8(2):109-114

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Amanita muscaria toxicosis in two dogs     

John H. Rossmeisl  Jr.  DVM  MS  DACVIM      Michael A. Higgins  DVM    Dennis J. Blodgett  DVM  PhD  DABVT    Matthew Ellis  DVM    Delbert E. Jones  MS 《Journal of Veterinary Emergency and Critical Care》2006,16(3):208-214

Objective: To report the manifestations, history, and pathophysiologic basis of disease in 2 dogs with Amanita muscaria toxicosis. Case summaries: Two dogs were evaluated for an acute onset of gastroenteritis and seizures. A. muscaria toxicosis was suspected in each dog after confirmation of environmental exposure and visualization of ingested mushrooms in vomitus. The diagnosis was confirmed following identification of toxic Amanita metabolites in the urine and serum of each dog. Administration of supportive and symptomatic therapies resulted in the complete recovery of each animal. Unique information provided: Ingestion of the mushroom, A. muscaria, by dogs can result in acute gastrointestinal distress that precedes a potentially life‐threatening central neurologic syndrome characterized by seizures, tremors, and somnolence. Central nervous system dysfunction results primarily from the actions of ibotenic acid and its decarboxylation product, muscimol, which are analogues of the neurotransmitters glutamate and γ‐aminobutyric acid (GABA), respectively. Identification of these toxins in the urine and serum of affected dogs using high‐performance liquid chromatography (HPLC) provides a definitive diagnosis.  相似文献   

Christos Gallis (ed.): Green care for human therapy,social innovation,rural economy,and education     

Matthew DelSesto 《Agriculture and Human Values》2017,34(1):239-240

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Variations in dark respiration and mitochondrial numbers within needles of Pinus radiata grown in ambient or elevated CO2 partial pressure     

Griffin KL  Anderson OR  Tissue DT  Turnbull MH  Whitehead D 《Tree physiology》2004,24(3):347-353

Within-leaf variations in cell size, mitochondrial numbers and dark respiration rates were compared in the most recently expanded tip, the mid-section and base of needles of Pinus radiata D. Don trees grown for 4 years in open-top chambers at ambient (36 Pa) or elevated (65 Pa) carbon dioxide partial pressure (p(CO2)a). Mitochondrial numbers and respiratory activity varied along the length of the needle, with the highest number of mitochondria per unit cytoplasm and the highest rate of respiration per unit leaf area at the base of the needle. Regardless of the location of the cells (tip, middle or basal sections), needles collected from trees grown in elevated p(CO2)a had nearly twice the number of mitochondria per unit cytoplasm as those grown in ambient p(CO2)a. This stimulation of mitochondrial density by growth at elevated p(CO2)a was greater at the tip of the needle (2.7 times more mitochondria than in needles grown in ambient CO2) than at the base of the needle (1.7 times). The mean size of individual mitochondria was unaffected either by growth at elevated p(CO2)a or by position along the needle. Tree growth at elevated p(CO2)a had a variable effect on respiration per unit leaf area, significantly increasing respiration in the tip of the needles (+25%) and decreasing respiration at the mid-section and base of the needles (-14% and -25%, respectively). Although a simple relationship between respiration per unit leaf area and mitochondrial number per unit cytoplasm was found within each CO2 treatment, the variable effect of growth at elevated p(CO2)a on respiration along the length of the needles indicates that a more complex relationship must determine the association between structure and function in these needles.  相似文献   

Stomatal and non-stomatal limitations to photosynthesis in four tree species in a temperate rainforest dominated by Dacrydium cupressinum in New Zealand     

Tissue DT  Griffin KL  Turnbull MH  Whitehead D 《Tree physiology》2005,25(4):447-456

We assessed the relative limitations to photosynthesis imposed by stomatal and non-stomatal processes in Dacrydium cupressinum Lamb. (Podocarpaceae), which is the dominant species in a native, mixed conifer-broad-leaved rainforest in New Zealand. For comparison, we included three co-occurring broad-leaved tree species (Meterosideros umbellata Cav. (Myrtaceae), Weinmannia racemosa L.f. (Cunoniaceae) and Quintinia acutifolia Kirk (Escalloniaceae)) that differ in phylogeny and in leaf morphology from D. cupressinum. We found that low foliage phosphorus content on an area basis (P(a)) limited light-saturated photosynthesis on an area basis (A(sat)) in Q. acutifolia. Depth in the canopy did not generally affect A(sat) or the relative limitations to A(sat) because of stomatal and non-stomatal constraints, despite reductions in the ratio of foliage mass to area, foliar nitrogen on an area basis (N(a)) and P(a) with depth in the canopy. In the canopy-dominant conifer D. cupressinum, A(sat) was low, consistent with low values of the maximum rate of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation (V(cmax)). In comparison, the A(sat) response of the three broad-leaved tree species was quite variable. Although A(sat) was high in the canopy-dominant M. umbellata, it was low in the sub-canopy trees W. racemosa and Q. acutifolia. Relative stomatal limitation to photosynthesis was more pronounced in W. racemosa (40%) than in the other three species (28-33%). Despite differences in degree, non-stomatal limitation to A(sat) predominated in all tree species.  相似文献   

Effect of sorbitol,single, and multidose activated charcoal administration on carprofen absorption following experimental overdose in dogs          下载免费PDF全文

Amy M. Koenigshof DVM  MS  DACVECC  Matthew W. Beal DVM  DACVECC  Robert H. Poppenga DVM  PhD  DABVT  L. Ari Jutkowitz VMD  DACVECC 《Journal of Veterinary Emergency and Critical Care》2015,25(5):606-610

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Seasonal parasitism of native egg parasitoids of brown marmorated stink bug (Halyomorpha halys) in Japan     

Kamiyama  Matthew T.  Matsuura  Kenji  Hata  Toshimitsu  Yoshimura  Tsuyoshi  Yang  Chin-Cheng Scotty 《Journal of pest science》2022,95(3):1067-1079

Journal of Pest Science - The invasive, Halyomorpha halys (Hemiptera: Pentatomidae), is a severe economic insect pest native to East Asia. A strong effort has been made to identify natural egg...  相似文献   

Correction to: Efficacy and safety of Eradicat® feral cat baits in eastern Australia: population impacts of baiting programmes on feral cats and non-target mammals and birds     

Fancourt  Bronwyn A.  Harry  Glen  Speed  James  Gentle  Matthew N. 《Journal of pest science》2022,95(1):523-524

Journal of Pest Science -  相似文献   

Optimal vision-based guidance row locating for autonomous agricultural machines     

Ruangurai  Piyanun  Dailey  Matthew N.  Ekpanyapong  Mongkol  Soni  Peeyush 《Precision Agriculture》2022,23(4):1205-1225

Precision Agriculture - With the rapid advances in precision agriculture technology, machine vision is emerging as a means to obtain accurate spatial information for a control system at relatively...  相似文献