Physiological and Serological Comparisons Among Strains of Mycoplasma granularum and Mycoplasma laidlawii

Mycoplasma granularum strains grew on a medium devoid of animal serum or of serum fractions containing sterols; all strains possessed properties, including carotenoid biosynthesis, similar to those described for M. laidlawii. Some common antigenic components were noted among M. granularum and M. laidlawii strains by indirect fluorescent-antibody tests. The growth of M. granularum strains was slightly inhibited by antiserum to M. laidlawii PG-8, and the electrophoretic patterns of cell proteins of the M. granularum strains showed a close resemblance to that of M. laidlawii. However, direct fluorescent-antibody procedures performed on colonies grown on a serum-free medium clearly distinguished M. granularum from M. laidlawii. The occurrence of nonsterol-requiring mycoplasmas, in addition to M. laidlawii, raises questions as to the taxonomy of M. granularum and of the saprophytic mycoplasmas in general.     

Co-managing soil and plant pathogens: effects of organic amendments on soil fertility and fungal pathogen survival

Backgrounds and aims

Interactions between plants can be both positive and negative, denoting facilitation and competition. Although facilitative effects of having legume neighbours (focus on yield productivity) are well studied, a better mechanistic understanding of how legumes interact with non-legumes in terms of root distribution is needed. We tested the effects of neighbour identity, its spatial location, as well as the effects of plant order of arrival on above and belowground traits and root distribution.

Methods

We performed a rhizotron experiment (4 weeks duration) in which we grew maize alone, with only a legume, only another grass, or with both species and tracked roots of the plant species using green and red fluorescent markers.

Results

Maize grew differently when it had a neighbour, with reduced development when growing with wheat compared to alone. Growing with a legume generally equated to the same outcome as not having a neighbour. Roots grew towards the legume species and away from the wheat. Order of arrival affected aboveground traits to a certain extent, but its effects on maize roots were dependent on spatial location.

Conclusions

Our study provides evidence of facilitation, showing the importance of the identity of the neighbours, together with their spatial location, and how order of arrival can modulate the outcome of these initial interactions.

     

Pharyngeal dilation associated with cricothyroid muscle contraction in dogs.

The mechanical function of phasic respiratory-related activity of the cricothyroid muscle of the larynx is poorly understood. We studied five adult cross-bred dogs (weight 14-20 kg) deeply anesthetized with pentobarbitone sodium, mechanically ventilated via a tracheostomy, and placed prone with the mouth open. Bilateral cricothyroid muscle contraction was induced by supramaximal electrical stimulation of the external branches of the superior laryngeal nerve. Computerized axial tomography was used to assess effects of cricothyroid muscle contraction. During cricothyroid muscle contraction, oropharyngeal (tip of epiglottis) cross-sectional area increased by 18.0 +/- 3.0% (SE) (P = 0.008), whereas combined left and right piriform recess cross-sectional area increased by 85 +/- 25% (n = 4; P = 0.02) at the midepiglottic level and by 152 +/- 37% (P = 0.01) at the base of the epiglottis. Furthermore, at the base of the epiglottis the maximum horizontal distance between the alae of the thyroid cartilage increased by 21 +/- 8% (P = 0.05). In contrast, lateral glottic diameter decreased by 52 +/- 2% (n = 4; P = 0.01), whereas dorsoventral glottic diameter increased by 18 +/- 5% (n = 4; P less than 0.02). The cricothyroid muscle, therefore, has the capacity to act simultaneously as a pharyngeal dilator and a glottic constrictor and thus may play a role in the control of oropharyngeal as well as laryngeal patency.     

Synthesis of Exopolysaccharide by Bradyrhizobium japonicum during Growth on Hydroaromatic Substrates

The hydroaromatic acids shikimate and quinate, which may be available as carbon sources in the soil, supported production of only low levels of acidic exopolysaccharide by Bradyrhizobium japonicum. Exopolysaccharide production (micrograms per 10 cells) was 4.9 on quinate and 4.5 on shikimate; in comparison, it was 128 on adipate, 18 on l-arabinose, and 39 on d-glucose.     

Behaviour-genetic analysis of Phormia regina II. Detection of a single,major-gene effect from behavioural variation for Central Excitatory State (CES) using hybrid crosses

Converging evidence from replicated hybrid analyses (and from selection and single-pair mating; Tully & Hirsch 1982) points to a single, major-gene correlate of the central excitatory state (CES) in pure breeding lines of the black blow-fly, Phormia regina. Analysis of reciprocal F₁s reveals no X-chromosome or cytoplasmic effects. Biometrical analysis indicates significant additive and environmental phenotypic variance components. No net dominance deviation or dominance variance is detectable (which is consistent with absence of intralocular dominance). An estimate of the number of segregating loci is near 1. A more general non-parametric method fails to reject the one-gene model.     

Saltwater intrusion affects nitrogen,phosphorus and iron transformations under oxic and anoxic conditions: an incubation experiment

Biogeochemistry - Low-lying coastal ecosystems are rapidly salinizing due to sea level rise and associated saltwater intrusion (SWI). In agricultural soils, SWI can alter biogeochemical cycling of...     

First fungus gnats of genus Manota Williston (Diptera: Mycetophilidae) from Japan

The genus Manota is recorded from Japan for the first time. Three new species, Manota satoyamanis, Manota indahae and Manota tunoae spp. nov., are described, based on specimens collected in an ecological sampling program of arthropods in the “satoyama” landscape of Ishikawa Prefecture. “Satoyama” represents the traditional rural landscape of Japan, which is characterized by a mosaic of secondary forests, plantations, ponds and rice paddy fields. The new species raise the number of Palearctic Manota species from five to eight.     

The retinoic acid binding protein CRABP2 is increased in murine models of degenerative joint disease

Introduction  

Osteoarthritis (OA) is a debilitating disease with poorly defined aetiology. Multiple signals are involved in directing the formation of cartilage during development and the vitamin A derivatives, the retinoids, figure prominently in embryonic cartilage formation. In the present study, we examined the expression of a retinoid-regulated gene in murine models of OA.