Response of colour and hygroscopic properties of Scots pine wood to thermal treatment

The effect of heat treatment on the surface colour and hygroscopic properties of pine wood were investigated in this study. Boards of Scots pine wood (Pinus sylvestris L.) were subjected to thermal treatment at 200°C, for 4, 6, and 8 h. The change of equilibrium moisture content and density values of the specimens in order to facilitate the understanding of the treated material behavior. The colour parameters L*, a* and b*, used to depict the total colour change (Δ E) of wood surface, were shown to change proportionally to the treatment intensity. Moreover, swelling in the tangential and radial directions and absorption of the specimens appeared to be enhanced in great extent by the thermal treatment process. The mean value of swelling percentage in the tangential direction decreased 10.26%, 17.22%, and 19.60% for specimens treated for 4, 6, and 8 h, respectively, referring to the final measurement after 72 h of immersion. In radial direction, mean value of swelling percentage decreased 19.56%, 32.75%, and 34.65% for treated for 4, 6 and 8 h, respectively, after 72 h immersion, which attests the decrease in swelling and improvement in the hygroscopic behavior of Scots pine wood.     

Density effects on environmental variance and expected response to selection in maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.)

The study aimed to address the optimal plant population density in maize that maximizes phenotypic expression and differentiation, and lessens environmental effects on genotypic expression in terms of the response to selection. A set of seven short-season hybrids (Rom set) was tested under rainfed conditions (2006, 2007) in Romania, and a set of seven long-season hybrids (Gr set) was tested with irrigation (2007) in Greece. Experimentation was conducted under ultra-low (ULD), low (LD), middle (MD), and high (HD) densities (0.74, 2.51, 4.20, 8.40 plants/m² for the Rom set, and 0.74, 3.13, 6.25, 8.33 plants/m² for the Gr set). Phenotypic expression and differentiation for grain yield were highest at the ULD. Coefficient of variation (CV) for grain yield, ear length and kernel row number decreased as density decreased. Environmental conditions and hybrid plant-yield potential (i.e., maximum yield per plant) were crucial for the optimal density that achieved the lowest environmental variance. For the Rom set the lowest CV for grain yield was obtained at the LD in the unfavourable season and at the ULD in the favourable season. The less acquired variance was achieved at the ULD for the highest yielding hybrids and at the LD for the lowest yielding hybrids, revealing a negative association between plant-yield potential and optimal density. Concluding, a density proximal to the ULD approximates absence of competition in maize, and optimizes three determinant parameters for successful selection: selection intensity, heritability and phenotypic differentiation.     

Effect of alleviating products with different mode of action on physiology and yield of olive under drought

Two years old self-rooted Koroneiki olive trees (Olea europaea L.) were subjected to two irrigation regimes, i.e. the fully irrigated and the severely water stressed trees, while they were treated with three alleviating products of different mode of action. The products used were the osmolyte glycine betaine, the antioxidant Ambiol and the heat and irradiance reflecting kaolin clay particles. The effects of product application and water regime on leaf characteristics, shoot and root growth, photosynthesis, leaf compatible solids (carbohydrates) concentration and yield were evaluated. All products applied, exhibited significant alleviating action, based on the relative alleviation index. Irrigated trees exhibited greater growth than drought stressed ones, while the ameliorating products maintained the water content of the leaves under drought conditions and resulted in lower leaf tissue density. On the other hand carbon assimilation rate, stomatal conductance and intrinsic water use efficiency were significantly reduced under drought stress, while the opposite stood for intercellular CO₂. Drought stress resulted in elevated sucrose leaf concentration, while the application of Ambiol increased stachyose concentration and that of glycine betaine did the same with the mannitol concentration. Among the alleviating products tested in this experiment Ambiol and glycine betaine had a significant positive effect on leaf water content, photosynthesis and yield under both drought and well irrigated conditions.     

Comparison of absorbable and nonabsorbable sutures for intradermal skin closure in cats

Paired skin incisions were made in 6 cats and closed intradermally with the copolymer of glycolide, ɛ-caprolacton, and trimethylene-carbonate, or polypropylene suture. The macroscopic and histologic appearance of the incisions was compared. Polypropylene suture compared favorably to glycolide, ɛ-caprolacton, and trimethylene-carbonate suture for closure of skin incisions in cats.     

Characterization and detection of a novel idaeovirus infecting blackcurrant

A novel virus was discovered in a blackcurrant accession (Ribes nigrum L.) at the USDA genebank in Oregon, USA. The genome consists of two positive-sense, single-stranded RNAs with the first encoding a 197 kDa multifunctional protein with methyl transferase, helicase and RNA-dependent RNA polymerase enzymatic motifs. The second molecule encodes two putative proteins; the 39 kDa movement and 30 kDa coat proteins. Both RNAs have conserved sequences and structures at the 5′ and 3′ termini. The genome organization, sequence and phylogenetic analyses indicate that the virus is a putative new member of the genus Idaeovirus, as it consistently groups with privet leaf blotch-associated virus and raspberry bushy dwarf virus. A duplex RT-PCR assay was developed for rapid detection of both genomic RNAs simultaneously. The work presented in this communication will assure the health status of blackcurrant plants in mother blocks, nurseries and production fields alike.     

Evaluation of porous medium hydraulic properties using experimental methods and RETC code

Two experimental procedures were used to determine both hydraulic properties, soil water retention θ(h) curve and unsaturated hydraulic conductivity K(θ), of a sand sample. Knowledge of hydraulic properties is essential, since they generally control soil water dynamics. A steady-state laboratory method was used for the simultaneous determination of θ(h) and K(θ). A one-step outflow method was used for the determination of diffusivity D(θ) and subsequently K(θ) from soil water retention data which were measured independently on the same sample and using the same apparatus. The comparison of K(θ) measured values from the above-mentioned methods showed very good agreement of the results. Also, the comparison between the experimental K(θ) and θ(h) functions and the predictions obtained using retention curve (RETC) code by simultaneous fit of experimental soil water retention and hydraulic conductivity data from outflow data, assuming the Mualem-van Genuchten model, showed very good agreement. It is noted that the main disadvantage of the one-step outflow method is the weakness to predict K(θ) values near saturation. This disadvantage could be overcome using RETC code with the above procedures, since the K(θ) values between the predictive approach and the steady-state method were similar.     

Carbon Disulphide (CS<Subscript>2</Subscript>) Promotes Sprouting and Affects the Metabolism of Harvested Minitubers Grown from True Potato Seed

Chemical agents may be used to overcome dormancy in potato tubers so as to permit early planting. In this paper, the effect of carbon disulphide on sprouting and related metabolic processes in potato tubers grown from true potato seed (TPS) was investigated. Carbon disulphide was applied to potato tubers derived from TPS, at a rate of 20 ml m^?3 container volume for 72 h. It accelerated tuber sprouting and increased tuber weight loss. It also caused an increase in the respiration rate, as well as ethylene emission from the tubers during the first 6 days after treatment. The respiration rate of carbon disulphide-treated tubers remained at a higher level than that of untreated controls for 35 days after treatment. In addition, carbon disulphide increased the concentrations of the soluble sugars sucrose and fructose, but not glucose, in the tuber tissues (buds, parenchyma). These findings suggest that carbon disulphide releases potato minitubers from dormancy and that dormancy breakage is associated with changes in tuber metabolism prior to the visible sprouting.     

Anesthesia and perioperative management of a pneumonectomized dog

Although left- or right-sided pneumonectomy is tolerated by normal dogs, complications impacting the respiratory, cardiovascular, and gastrointestinal systems are not uncommon. Pneumonectomy in dogs results in secondary changes in the remaining lung, which include: decreased compliance and vital capacity; and increased pulmonary vascular resistance potentially leading to right ventricular hypertrophy. Such alterations make the anesthetic management of an animal with one lung particularly challenging. This report describes a dog with a history of left pneumonectomy due to Aspergillus fumigatus pneumonia 3 yr before presentation. The dog presented with a vaginal wall prolapse, and surgical resection of the protruding vaginal wall, ovariectomy, and prophylactic gastropexy were performed. Anesthesia was induced with midazolam, fentanyl, and propofol and was maintained with isoflurane using intermittent positive pressure ventilation and a constant rate infusion of fentanyl. Epidural anesthesia was also used. Recovery and postoperative management were uncomplicated. Intensive hemodynamic and respiratory monitoring and appropriate response and treatment of any detected abnormalities, taking into consideration the pathophysiologic alterations occurring in a pneumonectomized animal, are required for successful perianesthetic management.     

Simulated Summertime Regional Ground-Level Ozone Concentrations over Greece

Ground-level ozone concentrations were estimated for Greece during a summer period of the year 2000 using the regional air quality model UAM-V off-line coupled with the mesoscale meteorological model MM5. An anthropogenic NOx, NMVOCs and CO emission inventory and biogenic NMVOCs emission data were used to support model simulations. The evaluation analysis indicates a quite satisfactory model performance in reproducing ozone levels. The simulated mean ozone concentrations are above the 32-ppb EU phytotoxicity limit over almost all continental and maritime areas of Greece. Over the greater part of the country, the background mean ozone levels range from 40 to 55 ppb. Ozone values higher than the 55-ppb EU human health protection limit reaching 60 ppb dominate part of the southern Aegean Sea that is influenced by the Athens urban plume. In the areas where anthropogenic emission densities are high, the mean ozone levels vary between 20 and 40 ppb. Over the greater part of Greece, the simulated mean daily maximum ozone concentrations range from 50 to 65 ppb. More enhanced maximum ozone concentrations up to 95 ppb mainly dominate over the greater areas of the two largest Greek urban centres (Athens and Thessaloniki) and over the continental and maritime areas south of Athens which are under the influence of the urban plume.     

Hybridization between cotton and Malvaceae species as a tool for production of partial interspecific aneuploid cotton plants

Cotton although is an autogamous species could be cross pollinated under favorable climate conditions and/or in the presence of pollinators. The coexistence of cotton with Malvaceae species raises questions on the possibility pollen to be exchanged among Malvaceae species and on the resulted consequences. The present work was undertaken to evaluate the in situ response of cotton flowers (G.hirsutum L, G. barbadense L.) and their F₁ interspecific hybrids when are artificially pollinated with Malva sylvestris L., Hibiscus syriacus L. and Abelmoschus esculentus Moench. Furthermore, an in vitro protocol was attempted to support embryos’ growth in order to produce viable progenies originating from crosses between cotton and the aforementioned Malvaceae species. The obtained results gave evidence that pollen from the above Malvaceae species stimulated cotton ovaries without successful hybridization. The interaction between pollen and cotton’s stigmas was higher at early stages when M. sylvestris was used as pollinator but in crosses with H. syriacus and A. esculentus more ovules were activated as revealed by the percentage of carpodesis and life-time of bolls onto maternal plants. Only crosses between cotton with okra produced cotton seeds under in situ conditions. The in vitro embryo-ovule culture protocol, used, increased the number of regenerated cotton plants, especially in crosses among F₁ interspecific cotton hybrids and A. esculentus. In this case, regenerated plants were recombinant aneuploids, combining traits from both cotton species. This novel cotton germplasm possessing unique chromosome rearrangements, at aneuploid level could be proved useful after cytogenetic, molecular or QTL genetic analysis referring to important agronomic traits.