Production of planting stock from wildings of four Shorea species

Seedling production from wildlings and early field performance of planted wildlings of four ecologically and commercially important Shorea species were studied in rainforest conditions of South Kalimantan (Indonesian Borneo). We report results from eight trials on Shorea johorensis, S. leprosula, S. faguetiana and S. parvifolia. Five trials were conducted in the nursery and three in the field. Growth medium, container type, wildling size or duration of shading period did not have significant effects on survival or growth of wildlings in the nursery. Keeping the potted wildlings in the greenhouse resulted in significantly higher survival than keeping them under shading net. Duration of greenhouse period had a significant effect on the survival of wildlings, with three weeks being the minimum period resulting in acceptable survival. Early field performance of hardened wildlings was better than that of seedlings raised from seed. Wildlings of 10–40 cm can be grown successfully in the nursery in several growth media and container types. A greenhouse period of 3–5 weeks is necessary for rooting and high survival. Use of wildlings is recommended as a supplementary method for producing dipterocarp planting stock. The techniques tested in the study are simple and appropriate for seedling production in conditions where skilled labor and advanced technology are not available.     

Transfer of the Kosena Rfk1 gene,required in hybrid seed production,from oilseed rape to turnip rape

Radiant frost is a major abiotic stress, and one of the principal limiting factors for agricultural production worldwide, including Australia. Legumes, including field pea, faba bean, lentil and chickpea, are very sensitive to chilling and freezing temperatures, particularly at the flowering, early pod formation and seed filling stages. Radiant frost events occur when plants and soil absorb the sunlight during the day time and radiate heat during the night when the sky is clear and the air is still. Dense chilled air settles into the lowest areas of the canopy, where the most serious frost damage occurs. The cold air causes nucleation of the intracellular fluid in plant tissues and the subsequent rupturing of the plasma membrane. Among the cool season grain legume crops, chickpea, lentil and faba bean and field pea are the most susceptible to radiant frost injury during the reproductive stages. The more sensitive stages are flowering and podding. Frost at the reproductive stage results in flower abortion, poor pod set and impaired pod filling, leading to a drastic reduction in yield and quality. In contrast, in the UK and European countries, frost stress is related to the vegetative stages and, in particular, the effects of frost have been studied on cotyledon, uni/tri-foliolate leaf and seedling stages during the first few weeks of growth. Few winter genotypes have been identified as frost tolerant at vegetative stages. Vegetative frost tolerance is not related to reproductive frost tolerance, and hybrids from the vegetative frost-tolerant genotypes may not necessarily be tolerant at the reproductive stage. Tolerance to radiant frost has an inverse relationship with plant age. In the field, frost tolerance decreases from the vegetative stage to reproductive stage. Unlike wheat and barley, it is difficult to analyse and score frost damage in grain legume crops due to the presence of various phenophases on one plant at the reproductive stage. The extent of frost damage depends on the specific phenophases on a particular plant. However, current studies on genetic transformation of cold tolerant gene(s), membrane modifications, anti-freeze substances and ice nucleating or inhibiting agents provide useful information to improve our current understanding on frost damage and related mechanisms. The effects of frost damage on yield and grain quality illustrate the significance of this area of research. This review discusses the problem of radiant frost damage to cool season legumes in Australia and the associated research that has been carried out to combat this problem locally and worldwide. The available literature varies between species, specific climatic conditions and origin.     

Simultaneous drying and densification of silver birch (Betula pendula L.) veneers: analysis of morphology,thickness swelling,and density profile

In this study, birch (Betula pendula L.) veneers were simultaneously densified and dried using a contact drying method at pressures of 1.5 and 3 MPa at 130 °C and compared with veneer dried in a laboratory-scale convective type dryer. Compression rate, thickness swelling, and the density profiles of the veneers were investigated. Furthermore, the microstructure of densified veneers was studied by scanning electron microscopy (SEM). A maximum veneer compression rate of 9 % was achieved at a pressure of 3 MPa. Under these conditions, the veneers were, on average, densified from 504 to 574 kg m^?3 (approximately 14 %). After water soaking, full set-recovery—recovery to the initial thickness—occurred. However, the swelling rate was lower for the densified veneer. Density profiles measurements showed that densification occurs throughout the veneers. The SEM images showed that the surface of the densified veneers were smoother, whilst no cracks were detected due to densification. Densification seemed to occur in vessels. Typically, rays were bent when there was a vessel nearby.     

Pituitary adenoma predisposition caused by germline mutations in the AIP gene

Pituitary adenomas are common in the general population, and understanding their molecular basis is of great interest. Combining chip-based technologies with genealogy data, we identified germline mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene in individuals with pituitary adenoma predisposition (PAP). AIP acts in cytoplasmic retention of the latent form of the aryl hydrocarbon receptor and also has other functions. In a population-based series from Northern Finland, two AIP mutations account for 16% of all patients diagnosed with pituitary adenomas secreting growth hormone and for 40% of the subset of patients who were diagnosed when they were younger than 35 years of age. Typically, PAP patients do not display a strong family history of pituitary adenoma; thus, AIP is an example of a low-penetrance tumor susceptibility gene.     

Phototoxic activity of a thiophene polyacetylene from Leuzea carthamoides

The thiophene polyacetylene (E)-1-[5-(hept-5-en-1,3-diynyl)-2-thienyl]ethan-1,2-diol, isolated from the roots of Leuzea carthamoides, showed phototoxic activity in the assay systems of histidine photo-oxidation, Artemia and Tubifex assays. The effects were compared with the standard photosensitizer xanthotoxin.     

Influence of thaxtomins in different combinations and concentrations on growth of micropropagated potato shoot cultures

Plant-pathogenic Streptomyces species produce a variety of different phytotoxic 4-nitroindol-3-yl-containing 2,5-dioxopiperazines (thaxtomins) that induce scab symptoms on potato tubers (Solanum tuberosum). The possible mutual synergistic or antagonistic effects of thaxtomins are unknown. Modified methodology using column chromatography allowed the purification of thaxtomin A in large quantities (27 mg, HPLC purity of 97%). Thaxtomin A ortho isomer, thaxtomin B, and C-14 deoxythaxtomin B (thaxtomin D) were also purified. All four compounds induced similar symptoms of reduced root and shoot growth, root swelling (10-200 ppb), or necrosis (200-1000 ppb) on micropropagated in vitro cultures of potato. The scab-resistant potato cvs. Sabina and Nicola were more tolerant to thaxtomins than was the scab-susceptible cv. Matilda. Thaxtomins applied in combinations showed additive effects but no synergism, whereas thaxtomins A and B displayed antagonism with thaxtomin A ortho isomer.     

Inhibition of linoleic acid oxidation by interaction with a protein-rich oat fraction

A protein-rich fraction from oat was found to protect linoleic acid against oxidation in an aqueous suspension containing soybean lipoxygenase-1 and micellar linoleic acid. In this system the oat fraction reduced the initial oxidation rate of linoleic acid by 50% when the oat fraction/linoleic acid ratio was 5:1 (w/w). The oat fraction did not act on the lipoxygenase enzyme but reduced the concentration of linoleic acid that serves as a substrate for lipoxygenase-1. To achieve the reduction in the oxidation rate a contact between linoleic acid and the oat fraction was required. The efficiency of the protection was dependent on the duration of this contact: the maximum protection was reached after a 5-min incubation period. However, total cessation of oxidation was not reached with any concentration of the oat fraction, indicating that the oxidizible and non-oxidizible forms of linoleic acid are in equilibrium. Because lipoxygenase-1 prefers the monomeric form of the substrate, the present findings agree with the hypothesis that the oat fraction reduces the concentration of monomolecular form of substrate. In most food systems monomolecular free linoleic acid is liberated slowly and at relatively low concentrations, therefore, even a small amount of the oat fraction would guard the system from oxidative deterioration.     

Aerosol particles in the developing world; a comparison between New Delhi in India and Beijing in China

In developing countries, aerosol particles damage the health of hundreds of millions of people. Migration from the country side to megacities increases emissions and exposure to particles. Some countries have started to limit emissions based on particulate mass, but this may increase particle number concentrations. In this study we discuss some earlier measurements carried out in the developing world and compare results from one-week measurement campaigns concerning the particle number size distribution and PM₁₀ mass concentrations in New Delhi, India and Beijing, China. Our results show that submicron particle concentrations are high in both places. The average PM₁₀ concentration was 360 μg/m³ in New Delhi and 120 μg/m³ in Beijing. The corresponding total particle number concentrations in the size range 3–800 nm were 63 000 cm^?3 and 35 000 cm^?3. Number and mass concentrations and their characteristics showed significantly different behaviour between these two locations, which stresses the importance of long-term simultaneous measurements of both quantities in different types of megacities.     

Density profile relation to hardness of viscoelastic thermal compressed (VTC) wood composite

Density profile relation to hardness of VTC wood composites was evaluated using X-ray densitometry and modified Brinell hardness method using different applied forces. Moreover, surface elasticity was evaluated. Prior to lamination, the low-density hybrid poplar (Populus deltoides × Populus trichocarpa L.) and Douglas-fir (Pseudotsuga menziesii L.) thin boards were compressed to 1.22 or 1.14 g/cm³, respectively. Two different kinds of laminations were made, either single layer of 1.5 mm thickness or two 1.5-mm layers bonded to unmodified wood. The results show that thicker laminate has a great positive influence on Brinell hardness. This study suggests that results from the existing method for Brinell hardness are not comparable, and if applied force is chosen without restraint, the effect on the hardness value is significant for inhomogeneous wood composites.     

Myosin I can act as a molecular force sensor

The ability to sense molecular tension is crucial for a wide array of cellular processes, including the detection of auditory stimuli, control of cell shape, and internalization and transport of membranes. We show that myosin I, a motor protein that has been implicated in powering key steps in these processes, dramatically alters its motile properties in response to tension. We measured the displacement generated by single myosin I molecules, and we determined the actin-attachment kinetics with varying tensions using an optical trap. The rate of myosin I detachment from actin decreases >75-fold under tension of 2 piconewtons or less, resulting in myosin I transitioning from a low (<0.2) to a high (>0.9) duty-ratio motor. This impressive tension sensitivity supports a role for myosin I as a molecular force sensor.