RETROSPECTIVE ASSESSMENT OF COMPUTED TOMOGRAPHIC IMAGING OF FELINE SINONASAL DISEASE IN 62 CATS     

William C.  Schoenborn  DVM  Erik R.  Wisner  DVM  Philip P.  Kass  DVM  PhD  Margaret  Dale 《Veterinary radiology & ultrasound》2003,44(2):185-195

Sixty-two cats with sinonasal disease were evaluated with computed tomography. Findings that may lead to a computed tomographic diagnosis of nasal neoplasia versus rhinitis included osteolysis of the paranasal bones, moderate to severe turbinate destruction, lysis of the nasal septum, the presence of a homogenous space occupying mass, and extension of the disease process into the orbit or facial soft tissues. These findings were not pathognomonic for neoplasia and may be associated with severe rhinitis; therefore, nasal biopsy was recommended. When compared with parallel radiographic studies, computed tomography was not more sensitive than radiographs at detecting the presence of nasal cavity abnormalities in cats with referable clinical signs but was more sensitive at localizing these changes and determining the extent of disease.  相似文献   

Quantifying scale-dependent effects of animal movement with simple percolation models   总被引：4，自引：0，他引：4  

R. H. Gardner  R. V. O'Neill  M. G. Turner  V. H. Dale 《Landscape Ecology》1989,3(3-4):217-227

A simple model of animal movement on random and patterned landscapes was used to explore the problems of extrapolating information across a range of spatial scales. Simulation results indicate that simple relation- ships between pattern and process will produce a variety of scale-dependent effects. These theoretical studies can be used to design experiments for determining the nature of scale-dependent processes and to estimate parameters for extrapolating information across scales.  相似文献   

Toxicological pathology of cockleburs (Xanthium spp.) for broiler chickens.     

M A Goodwin  E T Mallinson  J Brown  E C Player  K S Latimer  N Dale  W V Shaff  T G Dickson 《Avian diseases》1992,36(2):444-446

Spiking mortality syndrome (SMS) in chickens resembles cocklebur toxicity in cattle, sheep, pigs, and rats. In order to determine if cockleburs are toxic to broiler chicks, crushed burs were fed (25% wt:wt) to broilers for 21 days. Ingestion of cockleburs resulted in significant failure to properly gain body weight. Otherwise, chicks did not develop clinical signs of illness or gross or microscopic lesions. Although there were some significant differences in serum chemistry values among chick groups, there were no consistent patterns. Severe hypoglycemia is said to be a characteristic finding in chicks that die with SMS. Because glucose levels were not low in chicks that were fed cockleburs, we feel certain that cockleburs do not cause SMS.  相似文献   

Imidazolinone inhibition of acetohydroxyacid synthase in vitro and in vivo     

Mark A. Stidham  Dale L. Shaner 《Pest management science》1990,29(3):335-340

Imidazolinone herbicides inhibit the first enzyme of branched-chain amino acid biosynthesis, acetohydroxyacid synthase. The inhibition of the enzyme in vitro by these herbicides increases with incubation time, but is not irreversible, as deduced by reaction progress curves. In contrast to this result is the apparent irreversible inhibition of the enzyme by these imidazolinones that occurs when the herbicide is applied to intact corn plants. Plants treated with imidazolinone herbicide and then extracted showed dramatically reduced enzyme activity. This effect on extractable enzyme level occurred with several different imidazolinone herbicides in either foliar or soil application. The decrease in extractable enzyme activity could be observed within four hours after treatment. Herbicides other than imidazolinones did not reduce the extractable enzyme level. These findings suggest that the enzyme- imidazolinone interaction in vivo may be different from the interaction observed in vitro.  相似文献   

Experience with patterns of change in soil carbon resulting from forest plantation establishment in eastern Australia     

John Turner  Marcia J. Lambert  Dale W. Johnson 《Forest Ecology and Management》2005,220(1-3):259-269

Forest plantations are extensively established in eastern Australia for production of timber products and more recently, potentially for sequestration of carbon. Intensive management of these plantations involves clearing of existing vegetation, often using fire, ripping and/or mounding of the soil and weed control, followed by planting, use of fertilizers, and subsequent tending. The plantations are managed on a 10–30-year rotation and often have high growth rates and accumulation of carbon. However, after establishment, there are reduced inputs of carbon into the soil from prior vegetation or rapidly growing weeds, together with accelerated decomposition of soil organic matter as a result of disturbance, and this leads to a net loss of soil organic carbon. In some systems this loss of soil organic carbon is not balanced by carbon biomass sequestration until 5–10 years after establishment and on some sites, a reduction in soil organic carbon may remain until the end of the rotation. The patterns of accumulation and loss of carbon vary according to location, soil type and plantation management system. The effects of intensive forest establishment on soil organic carbon were evaluated in a number of studies in eastern Australia using time sequence and chronosequence studies and comparisons of plantation soils with those from adjacent undisturbed sites. There was a general pattern of reduced carbon in surface soil immediately after plantation establishment and with time this extended deeper into the soil profile. The actual quantities varied greatly depending on the soil type. The decline was primarily a result of losses of labile carbon and was greater when the previous land use had essentially been native vegetation or highly improved pastures as opposed to regrowth woodland, or native pasture, or degraded land. In the absence of further disturbance, soil organic carbon can accumulate to pre-establishment levels but many short rotation plantations are terminated prior to this being attained. The potential upper level of accumulation of soil carbon can be increased by alteration of the soil nutritional status using fertilizer application.  相似文献   

What is leadership?     

Klingborg DJ  Moore DA  Varea-Hammond S 《Journal of veterinary medical education》2006,33(2):280-283

The demand for more effective leadership is heard throughout the health professions. Modern concepts of leadership differ from the traditional definition of a charismatic individual leader. Historically, leadership has been vested in positions, while today leadership is seen as a role one moves continuously into and out of, depending on the circumstance. Leadership ideas have evolved so that newer characteristics of leaders include being a team builder; possessing creative and strategic thinking skills; demonstrating honesty and integrity; and having the ability to motivate others to action. This article discusses some of the history of leadership, current thoughts on attributes of effective leaders, and the differences and similarities between leaders and managers; identifies selected teachable leadership tools; and describes various styles and purposes of existing leadership programs.  相似文献   

Evaluation and implementation of a potential diagnostic molecular marker for H1‐conferred potato cyst nematode resistance in potato (Solanum tuberosum L.)     

Lee Schultz  Noel O. I. Cogan  Karen McLean  M. Finlay B. Dale  Glenn J. Bryan  John W. Forster  Anthony T. Slater 《Plant Breeding》2012,131(2):315-321

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Ecophysiological responses of a young blue gum (Eucalyptus globulus) plantation to weed control     

A Eyles  D Worledge  P Sands  ML Ottenschlaeger  SC Paterson  D Mendham  AP O'Grady 《Tree physiology》2012,32(8):1008-1020

Early weed control may improve the growth of forest plantations by influencing soil water and nutrient availability. To understand eucalypt growth responses to weed control, we examined the temporal responses of leaf gas-exchange, leaf nitrogen concentration (N) and water status of 7-month-old Eucalyptus globulus L. trees in a paired-plot field trial. In addition, we monitored the growth, leaf N and water status of the competing vegetation in the weed treatment. By the end of the 11-month experiment, complete weed control (WF treatment) of largely woody competitors increased the basal diameter of E. globulus by 14%. As indicated by pre-dawn water potentials of >?-?0.05 MPa, interspecies competition for water resources was minimal at this site. In contrast, competition for N appeared to be the major factor limiting growth. Estimations of total plot leaf N (g m(-2) ground) showed that competing vegetation accounted for up to 70% of the total leaf N at the start of the trial. This value fell to 15% by the end of the trial. Despite increased leaf N(area) in WF trees 5 months after imposition of weed control, the photosynthetic capacity (A(1500)) of E. globulus was unaffected by treatment suggesting that the growth gains from weed control were largely unrelated to changes in leaf-level photosynthesis. Increased nutrient availability brought about by weed control enabled trees to increase investment into leaf-area production. Estimates of whole-tree carbon budget based on direct measurements of dark respiration and A(1500) allowed us to clearly demonstrate the importance of leaf area driving greater productivity following early weed control in a nutrient-limited site.  相似文献   

Species Comparison of the Role of p38 MAP Kinase in the Female Reproductive System     

Radi ZA  Marusak RA  Morris DL 《Journal of toxicologic pathology》2009,22(2):109-124

The p38 mitogen-activated protein kinases (MAPKs) are members of discrete signal transduction pathways that have significant regulatory roles in a variety of biological processes, depending on the cell, tissue and organ type. p38 MAPKs are involved in inflammation, cell growth and differentiation and cell cycle. In the female reproductive system, p38 MAPKs are known to regulate various aspects of the reproductive process such as mammalian estrous and menstrual cycles as well as early pregnancy and parturition. p38 MAPKs have also been implicated in alterations and pathologies observed in the female reproductive system. Therefore, pharmacologic modulation of p38 MAPKs, and inter-connected signaling pathways (e.g., estrogen receptor signaling, c-fos, c-jun), may influence reproductive physiology and function. This article provides a critical, comparative review of available data on the roles of p38 MAPKs in the mammalian female reproductive system and in reproductive pathophysiology in humans and preclinical species. We first introduce fundamental differences and similarities of the mammalian female reproductive system that should be considered by toxicologists and toxicologic pathologists when assessing the effects of new pharmacologic agents on the female reproductive system. We then explore in detail the known roles for p38 MAPKs and related molecules in female reproduction. This foundation is then extended to pathological conditions in which p38 MAPKs are thought to play an integral role.  相似文献   

Comparison of physiological and antioxidant responses of Anoda cristata and cotton to progressive drought     

HH RATNAYAKA  WT MOLIN  TM STERLING 《Weed Research》2012,52(4):358-366

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