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.     

POLLINATION BIOLOGY,SELF-INCOMPATIBILITY,AND STERILITY IN IPOMOEA PANDURATA (L.) G. F. W. MEYER (CONVOLVULACEAE)

Ipomoea pandurata rarely produces seed. Sporophytic self-incompatibility is a secondary factor contributing to the reduced seed production because the principal pollinators, Bombus pennsylvanicus (Apidae) and Melitoma taurea (Anthophoridae), effect cross-pollination in most populations. Sterility, expressed as pollen tube failure in the style and as a sterility mechanism in the ovary, is the primary factor accounting for reduced seed production. It is difficult to reconcile the extensive geographical distribution of I. pandurata with this sterility.     

DNA CONTENT OF SEVEN SPECIES OF ASTEREAE AND ITS SIGNIFICANCE TO THEORIES OF CHROMOSOME EVOLUTION IN THE TRIBE

Relative amounts of nuclear DNA were determined in root tip cells of seven species of Astereae: Aster hydrophilus Greene, A. oblongifolius Nutt., A. riparius H.B.K., Machaeranthera boltoniae (Greene) Turner and Home, M. brevilingulata (Sch-Bip.) Turner and Home, M. parviflora Gray, and M. tenuis (S. Wats.) Turner and Home. The results show that A. hydrophilus and M. brevilingulata, with a chromosome number of n = 9, have less nuclear DNA than other closely related species which are either n = 4 or n = 5. Cytological analyses of meiosis in the intergeneric hybrid M. parviflora X A. hydrophilus showed cells with two or more small chromosomes of the latter species pairing with single large chromosomes of the former. Pachytene cells of the hybrids M. parviflora X A. hydrophilus, M. parviflora X A. riparius, and M. boltoniae X M. tenuis showed some unpaired chromosome segments. The significance of these results to chromosome evolution in the tribe Astereae is discussed.     

The interstitial crystal-nucleating sheet in molluscan Haliotis rufescens shell: A bio-polymeric composite

The interstitial green sheets in abalone shell nacre are shown to be bifacially differentiated trilaminate polymeric complexes, with glycoprotein layers sandwiching a central core containing chitin. They share some common feature with the organic matrix layers between the aragonite tablets in the nacre and the periostracum, and show similarities to the myostracum. Thus, although the green sheet is reported to be unique to the abalone shell, it represents an interesting model for the study of molluscan shell biomineralization processes. Indeed, during shell formation, prismatic and spherulitic aragonite precedes and follows the deposition of the interstitial green polymeric composite sheets, and there is evidence to suggest that these sheets demark the interruption of nacre synthesis and serve to nucleate the resumption of calcium carbonate crystal growth. The green polymeric interstitial sheet purified from the abalone shell was investigated by spectroscopic and imaging techniques: FTIR, confocal microscopy, scanning and transmission electron microscopy, and by pyrolysis combined with GC–MS. Structural and compositional differences are observed between the surfaces of the two sides of the interstitial polymeric composite sheets. Moreover, comparative crystallization experiments on the green sheet sides also reveal asymmetry with respect to the nucleation of calcium carbonate. These findings suggest that these bifacially differentiated interstitial composites may play an active role in the mineral assembly processes, with one of the surfaces acting as a crystal nucleator.     

FORAGER ATTRACTION BY SYMPATRIC IPOMOEA HEDERACEA AND I. PURPUREA (CONVOLVULACEAE) AND CORRESPONDING FORAGER BEHAVIOR AND ENERGETICS

Flowers of Ipomoea purpurea are larger, more colorful, more numerous per plant, and more conspicuous than those of I. hederacea. Because the nectar supply per flower is less variable i: I. purpurea and because the flowers of this species are visually more attractive, Bombus pennsylvanicus demonstrated a foraging preference and greater constancy for I. purpurea than for I. hederacea in experimental and natural sympatric populations in accordance with expectations derived from optimal foraging theory.     

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.     

Cannabinoid receptor agonists inhibit depolarization-induced calcium influx in cerebellar granule neurons.

Neuronal cannabinoid receptors (CB(1)) are coupled to inhibition of voltage-sensitive Ca(2+) channels (VSCCs) in several cell types. The purpose of these studies was to characterize the interaction between endogenous CB(1) receptors and VSCCs in cerebellar granule neurons (CGN). Ca(2+) transients were evoked by KCl-induced depolarization and imaged using fura-2. The CB(1) receptor agonists CP55940, Win 55212-2 and N-arachidonylethanolamine (anandamide) produced concentration-related decreases in peak amplitude of the Ca(2+) response and total Ca(2+) influx. Pre-treatment of CGN with pertussis toxin abolished agonist-mediated inhibition. The inhibitory effect of Win 55212-2 on Ca(2+) influx was additive with inhibition produced by omega-agatoxin IVA and nifedipine but not with omega-conotoxin GVIA, indicating that N-type VSCCs are the primary effector. Paradoxically, the CB(1) receptor antagonist, SR141716, also inhibited KCl-induced Ca(2+) influx into CGN in a concentration-related manner. SR141716 inhibition was pertussis toxin-insensitive and was not additive with the inhibition produced by Win 55212-2. Confocal imaging of CGN in primary culture demonstrate a high density of CB(1) receptor expression on CGN plasma membranes, including the neuritic processes. These data demonstrate that the CB(1) receptor is highly expressed by CGN and agonists serve as potent and efficacious inhibitory modulators of Ca(2+) influx through N-type VSCC.