Effect of protein supplementation on reproductive and productive performance in <Emphasis Type="Italic">Bos indicus</Emphasis> × <Emphasis Type="Italic">Bos taurus</Emphasis> heifers raised in the humid tropics of Costa Rica

In order to evaluate the effect of protein supplementation on the productive and reproductive performance of heifers, 45 Bos indicus × Bos taurus heifers, 673 ± 146 days of age and weighing about 340 kg, were divided into two groups. The control group (n = 23) continued without supplementation, but the supplemented group (SG; n = 22) received concentrate at a rate of 1% BW kg per day. Animals were adapted to the concentrate over a 15-day period and then supplemented for 30 days, after which estrus was synchronized using a progesterone implant. Back fat thickness (BFT) was assessed by ultrasound. The SG had better average daily weight gain than the nonsupplemented group (0.63 ± 0.16 vs. 0.51 ± 0.13 kg/day, P < 0.05) and tended to show a better percentage ovulation (P < 0.10, 77% vs. 57%, respectively). However, this tendency was not reflected in the final pregnancy rates. No differences were observed between groups in dry matter intake and body condition scores. SG with a high BFT (>0.70 cm) showed a better ovulation percentage than those with low BFT (<0.69 cm; P < 0.01). Additionally, the pregnancy rate of supplemented heifers with high BFT tended to be better than heifers with low BFT in this same group (67% vs. 30%, respectively, P < 0.10). It is concluded that protein supplementation improved reproductive performance and that ultrasonography to measure BFT may be used to estimate reproductive performance.     

Manufacture and filtration of the PM<Subscript>2.0</Subscript> of microfiber warp-knitted mesh fabrics dealing with tourmaline

Tourmaline can enhance filtering efficiency to PM_2.0 of microfiber warp-knitted mesh fabric. In this paper, microfiber warp-knitted mesh fabrics were designed with different mesh structures and mass fraction of tourmaline solution respectively. The effect of tourmaline concentration on filtering efficiency of fabrics was investigated. After the tourmaline solution, the strength of mesh fabrics and durability of tourmaline’s conglutination to the mesh fabrics were explored at the same time. The results shown that the filtering efficiency of microfiber warp-knitted mesh fabrics dealing with tourmaline was resentful. Breaking strength of fabrics decreases with increasing mass fraction of tourmaline solution. The resistant efficiency of fabrics and tourmaline adhesive on the mesh fabrics were still stable along with the increasing mass fraction of tourmaline.     

Transcrytalline structures and crystallization kinetics of Polyarylate/Nylon6 Islands-in-a-Sea conjugate fibers for high performance thermoplastic composite applications

We report the isothermal and non-isothermal crystallization kinetics and associated transcrystalline morphological features of polyarylate(PAR)/nylon6 islands-in-a-sea fibers, where 74 PAR islands serve as reinforcing fibers and nylon6 sea component acts as a semicrystalline matrix in final thermoplastic composites. The temperature-dependent polarized optical microscopic images obtained during a cooling process exhibit that the melt-crystallization is dominated by the interfacial crystallization of nylon6 on the surface of PAR fibers, leading to developing a transcrystalline structure. From the isothermal and non-isothermal melt-crystallization analyses of the islands-in-a sea fiber by using differential scanning calorimetry and the Avrami equation, the overall crystallization rates of the nylon6 sea component in the islands-in-a-sea fiber are found to be highly accelerated by the heterogeneous nucleating effect of the PAR island fibers. In addition, it is revealed that the isothermal and non-isothermal melt-crystallization kinetics of the nylon6 in the islands-in-a-sea fibers consists of two different mechanisms of the primary crystallization owing to the interfacial crystallization and the secondary crystallization due to the bulk crystallization.     

Behavioural interactions of seabirds with suspended mussel longlines

Increased abundances of a number of seabird species have been found in areas of mussel longline aquaculture (compared to control sites) in a recent study at Bantry Bay, southwest Ireland. The aim of this study was to investigate whether this form of mussel aquaculture also affects the activity budgets and foraging behaviour of these seabirds. Scan-sampling was used to compare seabird activity budgets between three areas of mussel longline aquaculture and three control sites. Foraging activities of Great-Northern Divers Gavia immer, an Annex 1 species under the Euopean Union's Birds Directive, were also compared between sites using focal sampling. The behaviour of gulls (Larus sp.), Cormorants Phalacrocorax carbo, Shags Phalacrocorax aristotelis and Great-Northern Divers (but not auks, Alcidae) differed significantly between areas of mussel aquaculture and control sites in this study. Mussel suspension buoys were heavily utilized by gulls, cormorants and shags as safe perching platforms for preening activities. Gulls also fed extensively on epifauna attached to the buoys. Great-Northern Divers spent more time snorkelling (head submerged in search of food) in mussel sites than in the control sites, however dive duration and visible foraging success rates did not differ significantly between sites. Overall, the environmental impact of mussel suspension culture appears to be positive or neutral on marine bird species occurring at this study site.     

Five-year effects of cutting and herbicide treatments on control of <Emphasis Type="Italic">Rhododendron flavum</Emphasis> Don., and macronutrient pools in eastern beech (<Emphasis Type="Italic">Fagus orientalis</Emphasis> Lipsky) forests of Turkey

This experiment was carried out in a mature (>100-year-old) eastern beech forest in the Eastern Black Sea Region (BSR) of Turkey. The effects of experimental practices to control the woody plant Rhododendron flavum Don., including grubbing, manual cutting, and foliar and cut-stump spraying with imazapyr and triclopyr, were assessed on understory and forest floor biomass and nutrients, as well as soil bulk density and nutrient content. The cut plots had 5, 15, and 38 times greater competing vegetation biomass than did the plots treated with triclopyr, grubbing, and imazapyr, respectively. Because of the increased biomass, the amount of understory N, P, Ca, K, S, and Mg content on the cut plots was also substantially higher when compared to the grubbed, imazapyr-treated, and triclopyr-treated plots. Triclopyr and imazapyr applications brought about two- and threefold greater dead organic matter on the forest floor than did cutting and grubbing, respectively. As a result, forest floor macronutrient contents on the imazapyr- and triclopyr-treated plots were significantly greater than on the cut plots. Five years after treatments, soil bulk density at the 10–20 cm depth on the imazapyr-sprayed plots was about 14% higher than that on other treatments. Herbicides, especially imazapyr and grubbing were effective in controlling rhododendron. Macronutrients stored in the rhododendron were released to the forest floor after vegetation was controlled with herbicides.     

A rapid and miniaturized system using Alamar blue to assess fungal spore viability: implications for biosecurity

Long-lasting viable fungal spores are one of the important aspects in emergence, spread and disease development of pathogenic fungi. We developed a rapid and miniaturized system using Alamar Blue (resazurin dye; 7-hydroxy-3H-phenoxazin-3-one 10-oxide) for assessing fungal spore viability, using the ascomycete Leptosphaeria maculans (causing blackleg disease on canola) as a ‘model pathogen’. The assay is dependent on the metabolic activity of viable fungal spores to convert the dark blue of resazurin (maximum absorbance 605 nm) into the pink colour of resorufin (maximum absorbance 573 nm). The Alamar Blue assay uses an optimised micro-titre based format that was far superior for determining fungal spore viability in comparison with current conventional techniques including trypan blue staining, a TC10 cellometer cell counter, or by assessing germination of the spores under the microscope. This new assay was also more rapid and reproducible than current conventional tests to detect viable spores. Viable spores could be reliably detected within two hours. The successful application of the Alamar Blue assay to measure fungal spore viability in the current study has important benefits for biosecurity operations relating to faster and more reliable confirmation of viability of potential invasive exotic fungal pathogens and in minimising any consequent disease outbreaks. The effectiveness of the Alamar Blue assay was confirmed by successfully determining the relative retention times of viable L. maculans ascospores across a range of different potential spore-carrier materials, including steel, fabric, wood, paper, rubber and leather, over a time period of eight months. To further confirm the wide applicability of the Alamar Blue assay, it was successfully applied to detect viable spores of fungal pathogens of diverse taxonomic groups, including Kabatiella caulivora, Magnaporthe oryzae and Puccinia striiformis f.sp. tritici, and also of the yeast Saccharomyces cerevisiae.