QUANTITATIVE MAGNETIC RESONANCE IMAGING OF THE NORMAL FELINE CRANIAL ABDOMEN

Magnetic resonance images of the cranial abdomen were acquired from 15 clinically normal cats. All cats had T1-weighted images, 8 cats had T2-images made and 7 cats had T1-weighted post Gd-DTPA images acquired. Signal intensity measurements for T1, T2, and T1 post contrast sequences were calculated for liver, spleen, gallbladder, renal cortex, renal medulla, pancreas, epaxial muscles, and peritoneal fat. On T1-weighted images the epaxial muscle had the lowest signal intensity, followed by renal medulla, spleen, renal cortex, pancreas, liver and fat, respectively. On T2-weighted images, epaxial muscle had the lowest signal intensity followed by liver, spleen, fat, and gallbladder lumen. Calculations of specific organ percent enhancement following contrast medium administration were made and compared with that reported in humans. A brief review of the potential clinical uses of MR in cats is presented.     

Emergence of Culicoides obsoletus from indoor and outdoor breeding sites

Culicoides obsoletus (Diptera: Ceratopogondae) is considered as the probable main vector of Bluetongue virus (BTV) in northern Europe. Its breeding sites are poorly documented at the present time. We report numerous emergences of C. obsoletus s. str. from soil samples collected in two holdings between August and September 2010. Specimens were collected regularly in the laboratory during 80 days. In one holding, 1584 C. obsoletus midges emerged from used litter collected inside a dairy cow building and 211 C. obsoletus midges emerged from manure left outside the farm buildings. In the second holding, the number of emergences observed was much lower, especially for indoor samples. We discuss the impact of the farming practices on the abundance of emergence between both holdings on one side and between indoor and outdoor breeding sites on the other side. The observation of a peak in emergence and high emergence rates recorded in the laboratory for indoor samples let us assume that these breeding sites are of great importance, especially when it comes to understand the biology of this widespread species and its role in the transmission of BTV.     

The viscoelastic properties of processed cheeses depend on their thermal history and fat polymorphism

Both the composition and the thermal kinetics that are applied to processed cheeses can affect their texture. This study investigated the effect of the storage conditions and thermal history on the viscoelastic properties of processed cheese and the physical properties of the fat phase. The microstructure of processed cheese has been characterized. Using a combination of physical techniques such as rheometry, differential scanning calorimetry, and X-ray diffraction, the partial crystallization of fat and the polymorphism of triacylglycerols (TG; main constituents of milk fat) were related to changes in the elastic modulus and tan δ as a function of temperature. In the small emulsion droplets (<1 μm) dispersed in processed cheeses, the solid fat phase was studied at a molecular level and showed differences as a function of the thermal history. Storage of processed cheese at 4 °C and its equilibration at 25 °C lead to partial crystallization of the fat phase, with the formation of a β' 2 L (40.9 ?) structure; on cooling at 2 °C min(-1), the formation of an α 3 L (65.8 ?) structure was characterized. The cooling of processed cheese from 60 to -10 °C leads to the formation of a single type of crystal: α 3 L (72 ?). Structural reorganizations of the solid fat phase characterized on heating allowed the interpretation of the elastic modulus evolution of processed cheese. This study evidenced polymorphism of TG in a complex food product such as processed cheese and allowed a better understanding of the viscoelastic properties as a function of the thermal history.     

A field evaluation of the Hasl wet-dry deposition collector

Samples of precipitation, dry deposition and total deposition have been obtained from Tutuila Island, American Samoa, since April 1976. These collections are part of a study of global levels of pollutants. The volume of rain water collected by a HASL wet/dry collector has averaged within 4% of the volume expected based on data obtained using a standard rain gauge. The deposition of Cl^?, SO ₄ ^?2 , NA⁺. Mg^?2 and K⁺ in the total collector, which is exposed continuously to the atmosphere, is about 10% greater than the deposition in the wet plus dry sides of the HASL collector.     

The rural crisis in Minnesota: Identifying social and economic vulnerability and new directions for the future

The rural crisis of the 1980s is described in terms of the economic and social vulnerability of rural farm areas. The crisis is shown spreading from farms through families to rural communities, schools, churches, counties and beyond. Rural communities are shown to be undergoing dramatic and non-cyclical change. Criteria are defined to identify rural counties vulnerable to further economic losses and include: dependence on agriculture for jobs, inadequate off farm income, population losses, declines in residential and commercial property value, and county fiscal crises due to loss of the tax base, delinquincies, and additional federal and state program changes and cutbacks. Social and economic distress are so extensive as to overwhelm conventional emergency intervention efforts to provide food, shelter, access to health care, and professional counseling. Peer support programs have been found to be effective at reaching farm families and helping them seek out the assistance of farm financial advisors, counselors, food shelves, and public assistance. Emerging attempts to link politically contending parties are discussed, specifically the Reinvest in Minnesota Coalition and the Rural Strategy Task Force consisting of major farm, church, and lending organizations. A strategy process and stakeholder analysis for local communities are presented together with recommendations for action that include creating a rural trend watch capability.     

Models to distinguish effects of landscape patterns and human population pressures associated with species loss in Canadian national parks

It is widely accepted that large protected areas are required to effectively conserve historical species composition. However, recent analyses of mammal species loss in Canadian and African national parks contradict earlier conclusions that extent of local extinctions (i.e., extirpations) is strongly inversely related to park size, suggesting that park size alone is inadequate to predict reserve designs that may sustain biodiversity. To plan protected areas that will meet conservation goals, reserve-design models that incorporate other landscape-scale factors in addition to reserve area are needed; potential factors include the types and intensity of land use and habitat change, together with land cover types, in and around parks. Additionally, human population size around parks, and visitor density in parks may affect species loss. We quantified land use, land cover, and human population in and around 24 Canadian national parks to model effects of human disturbance and changes in natural habitats on known mammal extirpations.Multiple regression models were compared using the Akaike Information Criterion (AIC_c). The most parsimonious model (AIC_c weighting w _i = 0.5391) emphasized effective habitat area in and around parks and not visitor numbers nor human population size around parks. Our model suggests that parks with as little as 3140 km² of effective habitat area inside may be large enough to conserve historical mammal species composition if they are also surrounded by at least 18 000 km² of effective habitat within 50 km of park boundaries.     

Cytauxzoon felis infections are present in bobcats (Lynx rufus) in a region where cytauxzoonosis is not recognized in domestic cats

This study was performed to determine the prevalence of Cytauxzoon felis (C. felis) infections in bobcats (Lynx rufus) from a region where C. felis is recognized in domestic cats, North Carolina (NC), and a region where C. felis is not recognized in domestic cats, Pennsylvania (PA). Samples from NC (n=32) were obtained post-mortem via cardiac puncture from legally trapped bobcats. Samples from PA (n=70) were collected post-mortem onto Nobuto blood collecting strips by the PA Game Commission. Each sample was tested using a C. felis specific PCR assay as well as a PCR assay targeting host DNA to rule out the presence of PCR inhibitors. Three samples were excluded due to the presence of PCR inhibitors. Thirty-three percent (10/30) of the samples from NC and 7% (5/69) of the samples from PA tested positive for the presence of C. felis. The proportion of C. felis positive bobcats from NC was significantly different than that from PA (P<0.005). Despite the lower prevalence of C. felis infections in bobcats from PA this finding is unique and indicates the potential for C. felis infections in domestic cats in the northeastern USA if the appropriate tick vectors are present. Veterinary practitioners in PA should be on alert for cytauxzoonosis in domestic cats. Further studies about the epidemiology and transmission of C. felis infections among both domestic cats and bobcats are needed.     

Modeling fire and landform influences on the distribution of old-growth pinyon-juniper woodland

Expansion of Pinus and Juniperus species into shrub steppe in semi-arid regions of the western United States has been widely documented and attributed in part to fire exclusion. If decreased fire frequency has been an important cause of woodland expansion, one would expect to find age structures dominated by younger trees on more fire-prone sites, with old-growth pinyon-juniper woodland limited to sites with lower fire risk. We compared current old-growth distribution with spatial models for fire risk in a 19-km² watershed in central Nevada, USA. Multiple GIS models were developed to represent fire susceptibility, according to abiotic factors representing fuels and topographic barriers to fire spread. We also developed cellular automata models to generate fire susceptibility surfaces that additionally account for neighborhood effects. Rule-based GIS models failed to predict old-growth distribution better than random models. Cellular automata models incorporating spatial heterogeneity of site productivity predicted old-growth distribution better than random models but with low accuracy, ranging from 58% agreement at the single-pixel (0.09-ha) scale to 80% agreement for 20-pixel neighborhoods. The best statistical model for predicting old-growth occurrence included the negative effect of topographic convergence index (local wetness), and the positive effects of solar insolation and proximity to rock outcrops. Results support the hypothesis that old-growth woodlands in the Great Basin are more likely to occur on sites with low fire risk. However, weak relationships suggest that old-growth woodlands have not been confined to fire-safe sites. Conservation efforts should consider the landscape context of old-growth woodlands across a broad landscape, with an emphasis on conserving landscape variability in tree age structure.     

Degradation of carbetamide and its chief metabolites in alkaline soil

The degradation kinetics of carbetamide D-(?)-N-ethyl-2(phenylcarbamoyloxy) propionamide and its potential metabolites have been measured at different temperatures in both unsterilized and sterilized alkaline soil. A very large difference in both rates and processes of degradation between compounds was found. The kinetic studies were conducted by quantitative and qualitative analysis of the transformed product using [¹⁴C]-labelled compounds. Good radioactivity recovery was obtained and the existence of an important non-extractable fraction was detected in all cases. This soil-bound fraction is attributed to either conjugation of aniline with soil organic matter or aromatic ring cleavage to give amino acid precursors.     

Glanzmann thrombasthenia in an Oldenbourg filly

An 18-month-old Oldenbourg filly was presented with a bleeding diathesis. Laboratory testing included platelet count, gingival bleeding time, prothrombin time (PT), activated partial thromboplastin time (aPTT), von Willebrand factor (vWf) antigen, clottable fibrinogen, clot retraction time, PFA-100 closure time, platelet aggregometry (on platelet-rich plasma), and thrombelastography (TEG). TEG was performed by using kaolin and tissue factor as coagulation activators. Expression of the platelet receptor for fibrinogen was assessed by flow cytometry by using anti CD41 (alpha(IIb) or glycoprotein IIb)/CD61 (beta(III) or glycoprotein IIIa) and anti-CD41 antibodies. Abnormal laboratory findings included prolonged oral mucosal bleeding time (>12 hours), prolonged closure time with collagen/ADP (>300 seconds), and absence of clot retraction after 60 minutes. TEG reaction times were similar with kaolin and tissue factor in the patient and a control horse. However, maximum amplitudes in the patient were decreased with both kaolin (43.7 mm; control, 63.9 mm) and tissue factor (37.7 mm; control, 57.8 mm). Platelet aggregation responses to ADP and collagen were profoundly reduced in the affected horse compared with a control. Flow cytometry showed an absence of CD41 and decreased expression of CD41/CD61-reacting antigen on the patient's platelets compared with those from a control horse. The laboratory findings supported a diagnosis of Glanzmann thrombasthenia, likely caused by a mutation in the gene encoding the GPIIb subunit.