Responses of a sterile red fungus to soil types,wheat varieties and the presence of certain isolates ofStreptomyces

The biological activities of a sterile red fungus (SRF) capable of plant growth promotion and suppression of take-all disease were investigated in soils collected from Lancelin, Newdegate and Mt. Barker regions of Western Australia. Further, the effects of three wheat cultivars and the presence of two isolates ofStreptomyces on the biological activities of the SRF were tested using the Lancelin soil. The biological activities of the SRF were greatest in the Lancelin and Newdegate (wheat field) soils and with the wheat cultivar Gutha. In in vitro studies the soil streptomycetes tested showed either a significant increase in the exudate production by the SRF, which had antifungal and growth promoting properties, or an inhibition of growth of the fungus. Streptomycete A63 which stimulated the exudate production by the SRF in vitro, however, did not enhance disease protection in vivo. On the other hand, protection from root rot by the SRF in vivo was reduced in the presence of the streptomycete isolate Ax which is capable of inhibiting the growth of the SRF in vitro.     

Emergent and effective properties in ecology and evolution

Emergent properties are often discussed in arguments concerning relationships among different levels. However, the different definitions of emergent properties sometimes confuse the arguments about macro-level phenomena, since some authors regard emergent properties not only as observable global patterns but as properties that affect and cause change in ecological and evolutionary processes. Thus it is important to distinguish higher-level or larger-scale properties that can influence particular ecological and evolutionary processes from those that cannot. I call the former properties effective properties. I gave examples that show why the distinctions between effective and non-effective properties are important.

     

Histological and mechanical evaluation of antifreeze peptide (Afp1m) cryopreserved skin grafts post transplantation in a rat model

The objective of this study was to evaluate the use of Afp1m as a cryopreservative agent for skin by examining the transplanted skin histological architecture and mechanical properties following subzero cryopreservation. Thirty four (34) rats with an average weight of 208 ± 31 g (mean ± SD), were used. Twenty four (n = 24) rats were equally divided into four groups: (i) immediate non-cryopreserved skin autografts (onto same site), (ii) immediate non-cryopreserved skin autografts (onto different sites), (iii) skin autografts cryopreserved with glycerol for 72 h and (iv) skin autografts cryopreserved with Afp1m for 72 h at −4 °C. Rounded shaped full-thickness 1.5–2.5 cm in diameter skin was excised from backs of rats for the autograft transplantation. Non-cryopreserved or cryopreserved auto skin graft were positioned onto the wound defects and stitched. Non-transplanted cryopreserved and non-cryopreserved skin strips from other ten rats (n = 10) were allowed for comparative biomechanical test. All skin grafts were subjected to histological and mechanical examinations at the end of day 21. Histological results revealed that tissue architecture especially the epidermal integrity and dermal-epidermal junction of the Afp1m cryopreserved skin grafts exhibited better histological appearance, good preservation of tissue architecture and structural integrity than glycerolized skin. However, there was no significant difference among these groups in other histological criteria. There were no significant differences among the 4 groups in skin graft mechanical properties namely maximum load. In conclusion, Afp1m were found to be able to preserve the microstructure as well as the viability and function of the skin destined for skin transplantation when was kept at −4 °C for 72 h.     

Soil structural aspects of decomposition of organic matter by micro-organisms

Soil architecture is the dominant control over microbially mediated decomposition processes in terrestrial ecosystems. Organic matter is physically protected in soil so that large amounts of well-decomposable compounds can be found in the vicinity of largely starving microbial populations. Among the mechanisms proposed to explain the phenomena of physical protection in soil are adsorption of organics on inorganic clay surfaces and entrapment of materials in aggregates or in places inaccessible to microbes. Indirect evidence for the existence of physical protection in soil is provided by the occurrence of a burst of microbial activity and related increased decomposition rates following disruption of soil structures, either by natural processes such as the remoistening of a dried soil or by human activities such as ploughing. In contrast, soil compaction has only little effect on the transformation of ¹⁴C-glucose. Another mechanism of control by soil structure and texture on decomposition in terrestrial ecosystems is through their impact on microbial turnover processes. The microbial population is not only the main biological agent of decomposition in soil, it is also an important, albeit small, pool through which most of the organic matter in soil passes. Estimates on the relative importance of different mechanisms controlling decomposition in soil could be derived from results of combined tracer and modelling studies. However, suitable methodology to quantify the relation between soil structure and biological processes as a function of different types and conditions of soils is still lacking.     

Growth,radicle and root hair development ofDeschampsia flexuosa (L.) Trin. seedlings in relation to soil acidity

Deschampsia flexuosa (L.) Trin. is an abundant grass species in the ground flora of acidic beech forests in southern Sweden. Generally, the species is restricted to a limited soil pH range (pH 4–5). The main objective was to study the influence of different soil acidities on germination, initial root development and on the growth of the species. The experiments were carried out under controlled conditions and designed to simulate the physico-chemical conditions present in the field. By using forest soils within the pH range 4.0 to 8.3 and artificial variation in pH (3.2 to 7.6) of soil-water extracts, it was possible to evaluate the influence of soil reaction and the H⁺ per se. In all experiments seeds have been used. Germination was significantly delayed in the very acid soil (pH 4.0) in comparison to the germination in soils within the pH range (4.4 to 6.4). Soil substances, other than the H⁺, might be responsible for this delay in germination, whereas development of the radicle was markedly affected by increasing H⁺ concentrations. Especially the development of root hairs was sensitive to H⁺ and was significantly reduced at a pH<-3.8. By increasing soil acidity the injury symptoms, including curling and discolouring, became more intense and at the highest acidity (pH 3.2) the radicles appeared brown, stunted and the root hairs were lacking. Most favourable growth was obtained at pH 4.4 and 5.0. Soil pH levels above and below this range limited both shoot and root growth. The results showed very good correspondence with observations made in Beech forest soils in southern Sweden, where the species was growing in soils within the pH range 3.9 to 5.1 with a peak growth at pH 4.3. This study shows that in soils at pH≤3.8, the poor development of the radicle may be crucial in the establishment ofDeschampsia flexuosa. Root hair development was more sensitive to soil acidity than radicle elongation. Germination was delayed in very acid Beech forest soils but other factors than the H-ion per se may be responsible for this delay.     

Preparation and evaluation of soluble epoxide hydrolase inhibitors with improved physical properties and potencies for treating diabetic neuropathic pain

Soluble epoxide hydrolase (sEH), a novel therapeutic target for neuropathic pain, is a largely cytosolic enzyme that degrades epoxy-fatty acids (EpFAs), an important class of lipid signaling molecules. Many inhibitors of sEH have been reported, and to date, the 1,3-disubstituted urea has the highest affinity reported for the sEH among the central pharmacophores evaluated. An earlier somewhat water soluble sEH inhibitor taken to the clinic for blood pressure control had mediocre potency (both affinity and kinetics) and a short in vivo half-life. We undertook a study to overcome these difficulties, but the sEH inhibitors carrying a 1,3-disubstituted urea often suffer poor physical properties that hinder their formulation. In this report, we described new strategies to improve the physical properties of sEH inhibitors with a 1,3-disubstituted urea while maintaining their potency and drug-target residence time (a complementary in vitro parameter) against sEH. To our surprise, we identified two structural modifications that substantially improve the potency and physical properties of sEH inhibitors carrying a 1,3-disubstituted urea pharmacophore. Such improvements will greatly facilitate the movement of sEH inhibitors to the clinic.     

Endoparasites observed within invertebrates used as live food items for captive wild birds: Overview and potential risks

To monitor and evaluate potential risks to birds’ health, invertebrate species that have been used as live food items had their body contents searched for endoparasites. The contents of approximately 10,000 invertebrates were analyzed. A principal component analysis was performed to study the relationship between the presence/absence of endoparasites and the characteristics of the invertebrates. In most of them, including the species preferred by birds such as caterpillars, waxworms, mealworms, most grasshoppers, and spiders, no organism was identified. Such findings suggest a low potential for parasite transmission associated with its consumption by birds. Although they had unknown or even unlikely implications for the birds’ health, gregarines, oxyurides Leidynema sp., and digenetic trematodes Monolecithotrema sp. were found in samples from woodlice, cockroaches, and centipedes, respectively. The only avian parasites observed in this study were Heterakis gallinarum in samples from earthworms and Acuaria spiralis from woodlice. Suggestively, soil invertebrates showed a higher prevalence of endoparasites and may represent a higher potential risk in comparison to the other categories of invertebrates sampled herein. Detritivory and collected origin were also explanatory variables related to the presence of endoparasites in the current study.