Anaerobic degradation of papermill sludge in a two-phase digester containing rumen microorganisms and colonized polyurethane foam

Summary The use of reticulated polyurethane foam as a support material for the immobilization of methanogenic associations and its application to the anaerobic treatment of fine particulate solid wastes was investigated. The colonization of polyurethane support particles in a continuous upflow reactor fed on a mixture of acetate, propionate and butyrate, was both rapid and dense. The combination of rumen microorganisms and colonized support particles in a two-phase digester resulted in an efficient anaerobic decomposition of papermill sludge.     

Eavesdropping on heterospecific alarm calls: from mechanisms to consequences

Animals often gather information from other species by eavesdropping on signals intended for others. We review the extent, benefits, mechanisms, and ecological and evolutionary consequences of eavesdropping on other species' alarm calls. Eavesdropping has been shown experimentally in about 70 vertebrate species, and can entail closely or distantly related species. The benefits of eavesdropping include prompting immediate anti‐predator responses, indirect enhancement of foraging or changed habitat use, and learning about predators. Eavesdropping on heterospecifics can provide more eyes looking for danger, complementary information to that from conspecifics, and potentially information at reduced cost. The response to heterospecific calls can be unlearned or learned. Unlearned responses occur when heterospecific calls have acoustic features similar to that used to recognize conspecific calls, or acoustic properties such as harsh sounds that prompt attention and may allow recognition or facilitate learning. Learning to recognize heterospecific alarm calls is probably essential to allow recognition of the diversity of alarm calls, but the evidence is largely indirect. The value of eavesdropping on different species is affected by problems of signal interception and the relevance of heterospecific alarm calls to the listener. These constraints on eavesdropping will affect how information flows among species and thus affect community function. Some species are ‘keystone’ information producers, while others largely seek information, and these differences probably affect the formation and function of mixed‐species groups. Eavesdroppers might also integrate alarm calls from multiple species to extract relevant and reliable information. Eavesdropping appears to set the stage for the evolution of interspecific deception and communication, and potentially affects communication within species. Overall, we now know that eavesdropping on heterospecific alarm calls is an important source of information for many species across the globe, and there are ample opportunities for research on mechanisms, fitness consequences and implications for community function and signalling evolution.     

Airway cellularity, lipid laden macrophages and microbiology of gastric juice and airways in children with reflux oesophagitis

Background and methods

Human metapneumovirus (hMPV) is a recently discovered respiratory virus associated with bronchiolitis, pneumonia, croup and exacerbations of asthma. Since respiratory viruses are frequently detected in patients with acute exacerbations of COPD (AE-COPD) it was our aim to investigate the frequency of hMPV detection in a prospective cohort of hospitalized patients with AE-COPD compared to patients with stable COPD and to smokers without by means of quantitative real-time RT-PCR.

Results

We analysed nasal lavage and induced sputum of 130 patients with AE-COPD, 65 patients with stable COPD and 34 smokers without COPD. HMPV was detected in 3/130 (2.3%) AE-COPD patients with a mean of 6.5 × 10⁵ viral copies/ml in nasal lavage and 1.88 × 10⁵ viral copies/ml in induced sputum. It was not found in patients with stable COPD or smokers without COPD.

Conclusion

HMPV is only found in a very small number of patients with AE-COPD. However it should be considered as a further possible viral trigger of AE-COPD because asymptomatic carriage is unlikely.     

Olfactory contribution to Fos expression during mating in inexperienced male hamsters

Male hamsters are very dependent on chemosensory cues for normal mating behavior. We have previously reported that central, vomeronasal pathways are intensely and selectively activated during mating or pheromonal stimulation. The contribution of main olfactory sensory input to the patterns of c-fos activation was investigated in this study. Sexually inexperienced male hamsters were either made anosmic by intranasal infusion of zinc sulfate or remained intact. Fos protein immunoreactivity was analyzed in main olfactory and vomeronasal pathways of the zinc sulfate-treated, anosmic animals after mating with receptive females for 45 min, and compared with Fos patterns seen in intact mating animals, some of which have been described in a previous publication. The zinc sulfate-treated anosmic males described here all mated when given access to receptive females. Whether mated or unstimulated, anosmic males had little or no Fos expression in main olfactory pathways; significantly less even than in unstimulated intact animals. Mating did not increase Fos expression in main olfactory pathways of intact animals over that of unstimulated intact controls. However, Fos expression in central vomeronasal pathways was significantly higher in mating anosmic males, as in intact males, compared with appropriate non-mating controls. Fos expression was significantly different between intact and zinc sulfate-treated anosmic mating males in only one area studied. The rostral anterior medial amygdala, known to receive a small olfactory terminal field, had significantly lower Fos expression in zinc sulfate-treated anosmic males that mated when compared with intact-mating animals. Thus, functional main olfactory input to the rostral vomeronasal amygdala can be demonstrated but does not appear to be critical for mating behavior in previously inexperienced male hamsters with intact vomeronasal organs. Other main olfactory input appears to have a negligible contribution to Fos-patterns in such animals.      

Intermediate filaments in nervous tissues

Intermediate filaments have been isolated from rabbit intradural spinal nerve roots by the axonal flotation method. This method was modified to avoid exposure of axons to low ionic strength medium. The purified filaments are morphologically 75-80 percent pure. The gel electrophoretogram shows four major bands migrating at 200,000, 145,000, 68,000, and 60,000 daltons, respectively. A similar preparation from rabbit brain shows four major polypeptides with mol wt of 200,000 145,000, 68,000, and 51,000 daltons. These results indicate that the neurofilament is composed of a triplet of polypepetides with mol wt of 200,000, 145,000, and 68,000 daltons. The 51,000-dalton band that appears in brain filament preparations as the major polypeptide seems to be of glial origin. The significance of the 60,000- dalton band in the nerve root filament preparation is unclear at this time. Antibodies raised against two of the triplet proteins isolated from calf brain localize by immunofluorescence to neurons in central and peripheral nerve. On the other hand, an antibody to the 51,000-dalton polypeptide gives only glial staining in the brain, and very weak peripheral nerve staining. Prolonged exposure of axons to low ionic strength medium solubilizes almost all of the triplet polypeptides, leaving behind only the 51,000- dalton component. This would indicate that the neurofilament is soluble at low ionic strength, whereas the glial filament is not. These results indicate that neurofilaments and glial filaments are composed of different polypeptides and have different solubility characteristics.     

The prevalence,type and severity of cardiovascular disease in diabetic and non-diabetic patients: A matched-paired retrospective analysis using coronary angiography as the diagnostic tool

People with diabetes mellitus have a 2–8-fold excess in cardiovascular mortality than people without diabetes. This study compared angiographically determined cardiovascular disease in 79 patients with diabetes mellitus and an equal number of matched controls without diabetes under the age of 55 years. Seventy-nine diabetic patients coming to coronary angiography during a 12-month period were reviewed retrospectively along with 79 control patients matched for age (±3 years), sex, ethnic origin and risk factors (hyperlipidemia, body mass index and smoking history). The angiographic features of a consecutive series of 62 European and 17 Asian patients and their matched-paired controls were assessed. In all study subjects had undergone elective coronary angiography and ventriculography. Angiographic findings were graded to describe severity and extent of coronary atherosclerosis. Left ventricular systolic function was assessed by ejection fraction. The diabetic group had a significantly higher arterial systolic pressure than the non-diabetic group (p < 0.008) and they were clinically obese with a body mass index of >30. Detailed analysis of the angiograms showed that prevalence and severity of coronary artery disease in diabetic patients was greater. The mean severity score was 11.66 for the diabetic group against 8.49 for the non-diabetic group (p < 0.037). Multivessel disease was more common in diabetic patients than in the controls, with three-vessel disease being the most common. Furthermore, 38 of 79 diabetic patients had three-vessel disease compared to 29 of 79 controls. Diabetic patients were also more likely to have more segments diseased in one vessel. Systolic function was reduced in the diabetic group, with a significantly lower (p < 0.05) mean ejection fraction. The present study supports the evidence that diabetic patients have more extensive coronary artery disease than non-diabetic patients and a poorer prognosis, and that the coronary arteries of the Asian patients were affected more adversely than those of the European group irrespective of the diabetic state. (Mol Cell Biochem 261: 263–269, 2004)     

The prevalence, type and severity of cardiovascular disease in diabetic and non-diabetic patients: a matched-paired retrospective analysis using coronary angiography as the diagnostic tool

People with diabetes mellitus have a 2-8-fold excess in cardiovascular mortality than people without diabetes. This study compared angiographically determined cardiovascular disease in 79 patients with diabetes mellitus and an equal number of matched controls without diabetes under the age of 55 years. Seventy-nine diabetic patients coming to coronary angiography during a 12-month period were reviewed retrospectively along with 79 control patients matched for age (+/- 3 years), sex, ethnic origin and risk factors (hyperlipidemia, body mass index and smoking history). The angiographic features of a consecutive series of 62 European and 17 Asian patients and their matched-paired controls were assessed. In all study subjects had undergone elective coronary angiography and ventriculography. Angiographic findings were graded to describe severity and extent of coronary atherosclerosis. Left ventricular systolic function was assessed by ejection fraction. The diabetic group had a significantly higher arterial systolic pressure than the non-diabetic group (p < 0.008) and they were clinically obese with a body mass index of >30. Detailed analysis of the angiograms showed that prevalence and severity of coronary artery disease in diabetic patients was greater. The mean 'severity score' was 11.66 for the diabetic group against 8.49 for the non-diabetic group (p < 0.037). Multivessel disease was more common in diabetic patients than in the controls, with three-vessel disease being the most common. Furthermore, 38 of 79 diabetic patients had three-vessel disease compared to 29 of 79 controls. Diabetic patients were also more likely to have more segments diseased in one vessel. Systolic function was reduced in the diabetic group, with a significantly lower (p < 0.05) mean ejection fraction. The present study supports the evidence that diabetic patients have more extensive coronary artery disease than non-diabetic patients and a poorer prognosis, and that the coronary arteries of the Asian patients were affected more adversely than those of the European group irrespective of the diabetic state.     

Intraspecific DNA divergence in Drosophila: a study on parthenogenetic D. mercatorum

Drosophila mercatorum is a species that can give rise to totally homozygous parthenogenetic strains. Using the technique of DNA-DNA hybridization, we have assessed the overall single-copy DNA differences among three independently derived strains that represent three independent genomes. Among strains, the average difference between homoduplex and heteroduplex median melting temperatures is 1.3 degrees C. This represents greater than or equal to 1.3% base-pair mismatch. Normalized percent of reassociation indicates further genetic differences, probably reflecting insertion/deletion differences and/or regions of the genome that are highly variable. This overall intraspecific genetic variation is higher than generally is thought to exist but is consistent with growing evidence of extensive DNA diversity within species of invertebrates. High intraspecific DNA variation may be correlated with rapid phyletic rates of evolution. Because of this high level of variation, the technique of DNA-DNA hybridization may be used to study intraspecific variation in invertebrates but is limited in its usefulness for higher systematic studies.