Understanding interaction effects of climate change and fire management on bird distributions through combined process and habitat models

Avian conservation efforts must account for changes in vegetation composition and structure associated with climate change. We modeled vegetation change and the probability of occurrence of birds to project changes in winter bird distributions associated with climate change and fire management in the northern Chihuahuan Desert (southwestern U.S.A.). We simulated vegetation change in a process-based model (Landscape and Fire Simulator) in which anticipated climate change was associated with doubling of current atmospheric carbon dioxide over the next 50 years. We estimated the relative probability of bird occurrence on the basis of statistical models derived from field observations of birds and data on vegetation type, topography, and roads. We selected 3 focal species, Scaled Quail (Callipepla squamata), Loggerhead Shrike (Lanius ludovicianus), and Rock Wren (Salpinctes obsoletus), that had a range of probabilities of occurrence for our study area. Our simulations projected increases in relative probability of bird occurrence in shrubland and decreases in grassland and Yucca spp. and ocotillo (Fouquieria splendens) vegetation. Generally, the relative probability of occurrence of all 3 species was highest in shrubland because leaf-area index values were lower in shrubland. This high probability of occurrence likely is related to the species' use of open vegetation for foraging. Fire suppression had little effect on projected vegetation composition because as climate changed there was less fuel and burned area. Our results show that if future water limits on plant type are considered, models that incorporate spatial data may suggest how and where different species of birds may respond to vegetation changes.

Leukemia inhibitory factor-dependent increase in myoblast cell number is associated with phosphotidylinositol 3-kinase-mediated inhibition of apoptosis and not mitosis

Leukemia inhibitory factor (LIF) is an important regulator of skeletal muscle regeneration and has been suggested to be mitogenic for myogenic cells because it has been shown to increase the quantity of myoblast cells grown in culture over extended periods of time. Using the established C2C12 murine myoblast cell line, we observed that LIF treatment did not significantly increase the rate at which myoblasts synthesise DNA under conditions which increased cell quantity by 73% above control, whilst the known mitogen fibroblast growth factor-2 significantly increased DNA synthesis under these conditions. Consequently, we examined the capacity of LIF to prevent apoptotic cell death. LIF treatment significantly reduced staurosporine-induced apoptotic DNA fragmentation by 37% compared to control and also reduced the proteolytic activation of caspase-3 by 40% compared to control. This effect of LIF was completely abolished by addition of the phosphatidylinositol 3-kinase inhibitor wortmannin, indicating that the phosphatidylinositol 3-kinase signalling pathway, previously shown to be linked to LIF-dependent increases in cell number, is necessary in mediating the anti-apoptotic effects of LIF. LIF treatment was also associated with increased levels of Bcl-xL and XIAP transcripts compared to control. Therefore, we suggest that the role of LIF in skeletal muscle regeneration and myogenesis is that of a survival factor rather than a mitogen.

Coherent 455 nm beam production in a cesium vapor

We observe coherent, cw, 455 nm blue-beam production via frequency upconversion in cesium vapor. Two IR lasers induce strong double excitation in a heated cesium vapor cell, allowing the atoms to undergo a double cascade and produce a coherent, collimated, blue beam copropagating with the two IR pump lasers.

Consistency of Response to Sumatriptan/Naproxen Sodium in a Placebo-Controlled, Crossover Study

Two identical randomized, placebo-controlled, crossover studies were conducted to evaluate consistency of response to sumatriptan/naproxen sodium 85/500 mg (S/NS) over four attacks in adults with migraine. Patients were instructed to treat within 1 h of pain onset while pain was mild. Co-primary end-points were pain-free response at 2 h (2hPF) and 24-h sustained pain-free response (24hSPF) calculated as percentages of all attacks. In Study 1, 570 patients treated 1693 attacks with S/NS and 424 with placebo. In Study 2, 565 patients treated 1678 attacks with S/NS and 422 with placebo. Compared with placebo, S/NS conferred higher 2hPF rates (Study 1: S/NS 52%, placebo 25%; Study 2: S/NS 50%, placebo 20%; both P < 0.001) and higher 24hSPF rates (Study 1: S/NS 37%, placebo 17%; Study 2: S/NS 34%, placebo 12%; both P < 0.001). 2hPF was reported in at least two of the first three S/NS-treated attacks in 55.0% of patients in Study 1 and 52.1% of patients in Study 2. 24hSPF was reported in at least two of the first three S/NS-treated attacks in 35.7% of patients in Study 1 and 32.6% of patients in Study 2. The incidences of any adverse event and of specific adverse events were low and generally similar between S/NS and placebo.

Does fever or myalgia indicate reduced physical performance capacity in viral infections?

To study prospectively the effects of a brief febrile viral infection on parameters of muscle and circulatory function, seven volunteers were inoculated with sandfly fever virus and two control subjects with sterile saline. During but not after fever, decreased isometric and dynamic strength and endurance were recorded in various muscles. Impairment could not be explained by altered activities of relevant muscle enzymes in serum or muscle tissue or by altered muscle ultrastructure, but correlated with the severity of perceived symptoms, including myalgia, as rated by each subject. Compared to baseline, cardiac stroke volume was lower during and after fever. During fever, an increased heart rate maintained cardiac output at pre-inoculation values, whereas cardiac output fell in early convalescence. This decrease in cardiac output correlated significantly with the severity of fever. Thus, in brief viral infections a transient impairment of muscle performance capacity is correlated to subjective symptoms such as myalgia, rather than to fever, whereas a decreased cardiac output following such infections seems to be associated with the fever reaction.

Are watershed and lacustrine controls on planktonic N2 fixation hierarchically structured?

N2 fixation can be an important source of N to limnetic ecosystems and can influence the structure of phytoplankton communities. However, watershed-scale conditions that favor N2 fixation in lakes and reservoirs have not been well studied. We measured N2 fixation and lacustrine variables monthly over a 19-month period in Waco Reservoir, Texas, USA, and linked these data with nutrient-loading estimates from a physically based watershed model. Readily available topographic, soil, land cover, effluent discharge, and climate data were used in the Soil and Water Assessment Tool (SWAT) to derive watershed nutrient-loading estimates. Categorical and regression tree (CART) analysis revealed that lacustrine and watershed correlates of N2 fixation were hierarchically structured. Lacustrine conditions showed greater predictive capability temporally. For instance, low NO3(-) concentration (<25 microg N/L) and high water temperatures (>27 degrees C) in the reservoir were correlated with the initiation of N2 fixation seasonally. When lacustrine conditions were favorable for N2 fixation, watershed conditions appeared to influence spatial patterns of N2 fixation within the reservoir. For example, spatially explicit patterns of N2 fixation were correlated with the ratio of N:P in nutrient loadings and the N loading rate, which were driven by anthropogenic activity in the watershed and periods of low stream flow, respectively. Although N2 fixation contributed <5% of the annual N load to the reservoir, 37% of the N load was derived from atmospheric N2 fixation during summertime when stream flow in the watershed was low. This study provides evidence that watershed anthropogenic activity can exert control on planktonic N2 fixation, but that temporality is controlled by lacustrine conditions. Furthermore, this study also supports suggestions that reduced inflows may increase the propensity of N2-fixing cyanobacterial blooms in receiving waters of anthropogenically modified landscapes.

Microreactors as New Tools for Drug Discovery and Development

In common with other producers of fine chemicals, the pharmaceutical industry can deploy flow microreactors to provide a more flexible production regime than is achievable with large-scale batch reactors. With monitoring of output flow, microreactors can be adjusted exquisitely to give enhanced and inherently safer protocols. Bulk production can be achieved through long run times or parallel reactors. However, microreactors can also be used advantageously in pharmaceutical R&D in other ways. This paper describes their use in the creation of a tool for rapid discovery and optimisation of leads to new drugs. Here microreactors are used to create an integrated micro-scaled chemical synthesis and bioassay system able to conduct fast-cycling iterative searches of diverse chemical space as an enhanced method for identifying and optimising novel lead chemotypes. The use of a microreactor to provide point-of-use access to PET ligands is also described. This significant down-scaling and acceleration of the synthesis of potent but short-lived biomarkers of disease could provide a means of significantly shortening the time and resources required to achieve a drug approval.

Naturally-occurring chronic renal disease in Australian cats: a prospective study of 184 cases

OBJECTIVE

To describe cases of naturally occurring feline chronic renal disease (CRD) in a defined population of Sydney.

DESIGN

Prospective case series.

METHODS

The inclusion criteria were the presence of a serum creatinine concentration above the reference range with either inadequately concentrated urine (urine specific gravity < or = 1.035), necropsy findings consistent with CRD, renal proteinuria or persistent azotaemia despite rehydration. Cats were excluded if a specific aetiology was identified ante or post mortem. Patients were divided into two categories (renal insufficiency or renal failure) on the basis of history, physical findings and serum creatinine concentration. The gender and age of cats with CRD was compared to an estimated Australian urban pet cat population. The breeds of cats with CRD were compared to the breeds of cats visiting the respective veterinary hospital where possible. Breed and gender comparisons were made using Fisher's exact tests. Age comparisons were made using Mann-Whitney U tests. The age at which cats were diagnosed with CRD was compared between veterinary hospitals using a Kruskal-Wallis test.

RESULTS

One hundred and eighty-four (99 female; 85 male) cats fulfilled the inclusion criteria. Amongst cats with CRD, males (median 12 years) were significantly younger than females (median 15 years; p = 0.001). The overall proportion of male and female cats with CRD was similar to that of the reference urban cat population (p = 0.41), however, between the ages of 9 and 11 years, male cats with CRD were over-represented (p = 0.038). Patients diagnosed with renal insufficiency (123 cats; median age 15 years) were significantly older than patients diagnosed with renal failure (61 cats; median age 11 years; p = 0.0001). The age at diagnosis of cats with CRD differed significantly between veterinary hospitals (p = 0.002).

CONCLUSION

Male cats with CRD were significantly younger than female cats with CRD. Younger cats were more likely to be diagnosed at an advanced stage of disease than older cats. The age at which cats were diagnosed with CRD was influenced by the clinic the cats attended. Whether these differences reflect differences in the aetiology of CRD or in the rate of disease progression warrants further investigation. Breed did not appear to play a significant role in the development of CRD in this survey.

Nocardia infections in cats: a retrospective multi-institutional study of 17 cases

OBJECTIVE

To record 17 cases of nocardiosis in cats from eastern Australia and to compare this series with cases previously reported.

DESIGN

Retrospective/prospective study.

RESULTS

Nocardia spp infections were diagnosed in 17 cats over 14 years from the three eastern states of Australia. There were no isolates from dogs during this period, but one isolate from a koala and two from dairy cows. The majority of cats presented with spreading lesions of the subcutis and skin associated with draining sinus tract(s). Early cutaneous lesions consisted of circumscribed abscesses. Infections spread at a variable rate, generally by extension to adjacent tissues. Lesions were generally located in regions subjected to cat bite or scratch injuries, including limbs, body wall, inguinal panniculus and nasal bridge. In some other cases, lesions were situated on distal extremities. The clinical course was variable, from chronic, indolent, initially localised infections to acute fulminating disease. Of the 17 cats, 14 were domestic crossbreds and three were purebreds. There was a preponderance of male cats (12 castrated, 1 entire young adult, 1 entire kitten). Nine of 17 cats were 10 years or older. Interestingly, the majority of infections were attributable to N nova. Immediate and/or predisposing causes could be identified in all cases, and included: renal transplantation [one cat]; chronic corticosteroid administration [three cats]; catabolic state following chylothorax surgery [one cat]; fight injuries [seven cats]; FIV infections [three of seven cats tested]. Of the 17 cats, three were apparently cured. Four were thought to be cured, but infection recurred after several months. Three cats responded partially but were euthanased, while another was improving when it died of unrelated complications. Two died despite treatment and two were euthanased without an attempt at therapy. For two cats there were either insufficient records or the patient was lost to follow up.

CONCLUSION

Nocardiosis is a rare, serious disease. Currently it is more common in cats than dogs. Nocardial panniculitis may be clinically indistinguishable from the syndrome caused by rapidly growing mycobacteria. Although the prognosis is guarded, patients with localised infections caused by N nova often respond to appropriate therapy. If definitive treatment is delayed because of misdiagnosis, the disease tends to become chronic, extensive and refractory. Insufficient duration of therapy leads to disease recurrence.

Rskalpha-actin/hIGF-1 transgenic mice with increased IGF-I in skeletal muscle and blood: impact on regeneration, denervation and muscular dystrophy

Human IGF-I was over-expressed in skeletal muscles of C57/BL6xCBA mice under the control of the rat skeletal alpha-actin gene promoter. RT-PCR verified expression of the transgene in skeletal muscle but not in the liver of 1- and 21-day old heterozygote transgenic mice. The concentration of endogenous mouse IGF-I, measured by an immunoassay which does not detect human IGF-I, was not significantly different between transgenic mice and wild-type littermates (9.5 +/- 0.8 and 13.3 +/- 1.9 ng/g in muscle; 158.3 +/- 18.6 and 132.9 +/- 33.1 ng/ml in plasma, respectively). In contrast, quantitation with antibodies to human IGF-I showed an increase in IGF-I of about 100 ng/ml in plasma and 150 ng/g in muscle of transgenic mice at 6 months of age. Transgenic males, compared to their age matched wild-type littermates, had a significantly higher body weight (38.6 +/- 0.53 g vs. 35.8 +/- 0.64 g at 6 months of age; P < 0.001), dry fat-free carcass mass (5.51 +/- 0.085 vs. 5.08 +/- 0.092 g; P < 0.001) and myofibrillar protein mass (1.62 +/- 0.045 vs. 1.49 +/- 0.048 g; P < 0.05), although the fractional content of fat in the carcass was lower (167 +/- 7.0 vs. 197 +/- 7.7 g/kg wet weight) in transgenic animals. There was no evidence of muscle hypertrophy and no change in the proportion of slow type I myofibres in the limb muscles of Rskalpha-actin/hIGF-I transgenic mice at 3 or 6 months of age. Phenotypic changes in Rskalpha-actin/hIGF-I mice are likely to be due to systemic as well as autocrine/paracrine effects of overproduction of IGF-I due to expression of the human IGF-I transgene. The effect of muscle specific over-expression of Rskalpha-actin/hIGF-I transgene was tested on: (i) muscle regeneration in auto-transplanted whole muscle grafts; (ii) myofibre atrophy following sciatic nerve transection; and (iii) sarolemmal damage and myofibre necrosis in dystrophic mdx muscle. No beneficial effect of muscle specific over-expression of Rskalpha-actin/hIGF-I transgene was seen in these three experimental models.

LIVE TULAREMIA VACCINE I. : Host-Parasite Relationship in Monkeys Vaccinated Intracutaneously or Aerogenically

Eigelsbach, H. T. (Fort Detrick, Frederick, Md.), J. J. Tulis, M. H. McGavran and J. D. White. Live tularemia vaccine. I. Host-parasite relationship in monkeys vaccinated intracutaneously or aerogenically. J. Bacteriol. 84:1020-1027. 1962.-Bacteriological, histological, immunohistochemical, and serological studies were made on monkeys administered live tularemia vaccine strain LVS by either of two routes. Comparative data are presented on nonvaccinated monkeys exposed via the respiratory route to a highly virulent strain of Pasteurella tularensis. Tissue changes resulting from either aerogenic or intracutaneous vaccination were mild, and consisted primarily of the proliferation of histiocytes without the formation of granulomas. The vaccine strain was isolated from the site of vaccination of animals inoculated dermally, from the lungs of animals vaccinated aerogenically, and from the regional lymph nodes, liver, and spleen of both groups; it was not isolated from the blood or bone marrow. Proliferation of the vaccine strain at the site of dermal inoculation and in the lungs of animals exposed aerogenically was observed within 24 hr; in both groups, the maximal viable population was reached within 3 days and maintained through the 10th day. A reduction in the number of viable vaccine organisms had begun by the 14th day; isolations were obtained only from the regional lymph nodes on the 28th day, and the vaccine strain was not isolated from any of the tissues cultured on the 90th day. Because the monkey is less resistant to tularemia than is man, the benign response of this animal to live tularemia vaccine indicates that the vaccine might also be safe for man when administered by either the dermal or respiratory route.

Blue five-level frequency-upconversion system in rubidium

We demonstrate production of continuous coherent blue laser light by using a five-level system in rubidium vapor. Two low-power lasers, at 780 and 776 nm, induce strong atomic coherence in the 5S-5P-5D states. The atoms decay to the 6P excited state, from which stimulated emission produces a coherent blue (420 nm) beam. We have coupled both ground-state hyperfine levels, effecting coherence between four levels. The coherent blue output is enhanced by several mechanisms, including stronger coupling to a larger fraction of the atomic population, operation at a detuning such that the vapor is nominally transparent to the 780 nm pump field, reduced losses owing to optical pumping, and optimal phase matching. We report experimental findings and compare them with results from a semiclassical Maxwell-Bloch model.

Seroprevalence study of feline coronavirus in owned and feral cats in Sydney, Australia

OBJECTIVES

i) To establish the seroprevalence of Feline Coronavirus (FCoV) infection in two defined groups of cats in Sydney: owned and feral cats; ii) to identify factors associated with an increased risk of infection with FCoV; and iii) to establish the seroprevalence and FCoV antibody titres of owned cats with immunohistochemically confirmed feline infectious peritonitis (FIP).

DESIGN

Prospective multi-institutional cross sectional study. Procedure Serum samples from owned cats presented to three inner city veterinary clinics in Sydney and feral cats from a colony in South Western Sydney over an 11-month period were tested for FCoV antibodies using the Immunocomb test kit. The relationship between serological score and six major factors (breed, age, gender, number of cats per household, living environment and health status) in the owned cat sample population was analysed and compared to cats with FIR RESULTS: The seroprevalence of FCoV infection in the sample population of owned and feral cats was 34% and 0%, respectively. The median Immunocomb scores of DSH, Persian, Siamese and Devon Rex cats were significantly lower than that of Burmese, BSH, Abyssinian, Birman, Ragdoll and Russian Blue. The median lmmunocomb score of pedigree cats less than 2 years-of-age was significantly higher than for pedigree cats greater than 2 years-of-age. This distinction was not evident in DSH cats in these age groups. The number of cats per household at the time of blood collection had a strong positive association with Immunocomb score. The median Immunocomb score of cats with immunohistochemically confirmed FIP was significantly higher than cats in the sample population of owned cats but there was sufficient overlap between these two groups to make definitive diagnosis of FIP by serology impossible.

CONCLUSION

This represents the first seroprevalence study of FCoV in Australia. The major determinants of antibody score of owned cats identified in this study were breed, age and the number of cats per household. The significant relationship between the breed of the cat and the FCoV antibody titre further supports the notion, proposed previously by the authors, that breed related differences exist in the immunological response to FCoV infection.

Clinicopathological findings associated with feline infectious peritonitis in Sydney, Australia: 42 cases (1990-2002)

OBJECTIVES

To review the clinicopathological findings in naturally-occurring, histopathologically confirmed cases of feline infectious peritonitis in client-owned cats in Sydney, Australia, with the purpose of identifying factors assisting in the diagnosis of this complex disease syndrome and to characterise the disease as it occurs in this region.

DESIGN

Retrospective clinical study: the clinical records of all cats with histopathologically confirmed feline infectious peritonitis at the University Veterinary Centre Sydney and a private cat hospital in Sydney between 1990 and 2002 were reviewed for signalment, history, physical findings, diagnostic test results and the distribution of histological lesions throughout the body at necropsy.

RESULTS

Forty-two cats met the inclusion criteria. Significant features of this study that unique to the contemporary literature are i) the over-representation of certain breeds (Burmese, Australian Mist, British Shorthaired, and Cornish Rex) and the under-representation of other breeds (Domestic Shorthaired, Persian); ii) the overrepresentation of males; iii) the tendency for effusive disease in Australian Mist cats and non-effusive disease in Burmese; iv) the even age distribution of disease seen in cats older than 2 years-of-age; and v) the presence of fulminant immune-mediated haemolytic anaemia in two cats in this study.

CONCLUSION

The study highlights the diverse range of clinical manifestations and the complexities experienced by clinicians in diagnosing this fatal disease. Some aspects of the epidemiology and clinical manifestations of feline infectious peritonitis appear different to the disease encountered in Europe and North America, most notably the over-representation of specific breeds and the presence of immune-mediated haemolytic anaemia.

New technique for in-situ measurement of backscattered and secondary electron yields for the calculation of signal-to-noise ratio in a SEM

The quality of an image generated by a scanning electron microscope is dependent on secondary emission, which is a strong function of surface condition. Thus, empirical formulae and available databases are unable to take into account actual metrology conditions. This paper introduces a simple and reliable measurement technique to measure secondary electron yield (delta) and backscattered electron yield (eta) that is suitable for in-situ measurements on a specimen immediately prior to imaging. The reliability of this technique is validated on a number of homogenous surfaces. The measured electron yields are shown to be within the range of published data and the calculated signal-to-noise ratio compares favourably with that estimated from the image.

The prevalence of feline A/B blood types in the Sydney region

OBJECTIVE

To determine the distribution of A/B blood types in pedigree and crossbred cats in the Sydney region, and to estimate the associated risk of administering incompatible blood in an unmatched random transfusion.

DESIGN

A prospective/retrospective study of blood specimens collected from both sick and healthy cats.

MATERIALS AND METHODS

Blood was collected from 355 cats from the Sydney region over a 12-year period from 1992 to 2003. Specimens were obtained from 187 domestic crossbred cats (short and long-haired) and 168 pedigree cats. The blood type of each cat was determined by one of three different laboratories using standard methods that varied over the duration of the survey.

RESULTS

The distributions of blood types obtained by the three laboratories were not significantly different. The prevalence of type-A, type-B and type-AB blood types in crossbred cats was 62%, 36% and 1.6%, respectively. This is the highest percentage of type-B cats so far reported for an outbred population of domestic cats, and is significantly higher than the 26% reported previously for cats in the Brisbane region. The calculated frequency for the type-B allele assuming Hardy-Weinberg equilibrium for this feline population is 0.60; the corresponding frequency of the type-A allele is thus approximately 0.40. The calculated proportion of random transfusions from this population giving rise to an incompatible blood transfusion is 46%, with half of these being life-threatening events. The calculated proportion of random matings from this population at risk for developing neonatal isoerythrolysis is 23%. The distribution of A and B blood types for pedigree cats was in general agreement with data reported previously for cats in North America and Europe, suggesting that the distribution of blood types in these purebred populations is relatively consistent throughout the world.

CONCLUSIONS

The prevalence of type B cats in the owned domestic and pedigree cat population is so high that blood typing or cross matching prior to transfusion should be mandatory, except in Siamese/Oriental cats.

Primary amyloidosis of the breast associated with invasive breast cancer

Amyloidosis is usually a systemic disorder. A localised form can involve the breast and may mimic breast cancer. We report a case of primary amyloid deposit confirmed by immunohistochemistry, occurring in a patient with early breast cancer and review other cases of breast involvement with various types of amyloid.