Effects of NCO/OH ratios and polyols during polymerization of water-based polyurethanes on polyurethane modified polylactide fabrics

Polylactides (PLAs) are a type of environmental friendly material. PLA fabrics feature excellent performance in terms of texture, comfort, curling effect, crystallinity, and transparency. However, because of its aliphatic polyester structure, PLA is relatively fragile as compared with the commercially available products like PET or Nylon. This study adopted water-based polyurethane (PU) to modify the surface of PLA fabrics, thereby enhancing the fabrics’ mechanical properties. Various polyols such as polytetrahydrofuran (PTMG), polycaprolactone diol (PCL), and polycarbonates diol (PC) were used and various NCO/OH molar ratios were designed in this study. As the PLA fabric was processed by dipping in various PU dispersions, it was found that the breaking strength of the fabric was increased, while its elongation at breakage decreased. Particularly, the breaking strength of the fabric modified by PUD50PC containing 50 weight percent of PC and two other polyols was the most prominent showing an 80 % increase in strength. Furthermore, the abrasion resistance of the PUD50PC-modified PLA fabric showed a roughly 6 times increase as compared to the plain PLA fabric. SEM images also reveal that after processing with water-based PU, the PLA fibers are bonded tightly with the water-based PU molecules to increase the breaking strength of the PLA fabrics.     

Migration and spawning behavior of the greater amberjack Seriola dumerili in eastern Taiwan

Greater amberjack (Seriola dumerili) is an important fishery resource with a circumglobal distribution from tropical to temperate waters. Here, we investigated the spawning migration and habitat utilization of S. dumerili in the East China Sea (ECS). Archival tags were attached to 22 adult fish to examine their horizontal and vertical movements and estimate the spawning ground. S. dumerili were captured and released in the coastal waters of eastern Taiwan on November of 2016 and 2017. Information from seven pop-up satellite archival tags and seven depth–temperature recorders was recovered. Almost all of the fish stayed in the Taiwanese exclusive economic zone. Most individuals moved from released site to the southern edge of the ECS and showed behavior associated with the topographic features in winter (November to December). These phenomena may be related to foraging and be driven by oceanographic features such as the seasonal monsoon and the Kuroshio. The fish then migrated to the south offshore area of Taiwan in January and February. During their southward migration, the fish experienced a slowly elevated water temperature regime (SETR), which is one of the environmental factors that induce final oocyte maturation. In the spawning season (February to April), tagged females exhibited continuous diel vertical movements (DVMs) after experiencing the SETR. These continuous DVMs were observed over a wide geographic range from north to south in the Kuroshio off eastern Taiwan. Our study demonstrated that the putative spawning ground of S. dumerili must extend further in a north–south direction than predicted in a previous study.     

Transfer of resistance to race 2 of Plasmodiophora brassicae from Brassica napus to cabbage (B. oleracea var. capitata). II. Meiosis in the interspecific hybrids between B. napus and 2x and 4x cabbage

Summary Meiosis in 14 interspecific F₁ hybrids with three chromosomal levels (triploid, tetraploid, hexaploid; 2n=28, 37 and 55) between Brassica napus L. and 2x and 4x cabbage (B. oleracea var. capitata L.) was studied. The oleracea genome from B. napus maintained close homology with the c genome of cabbage while the campestris genome of B. napus showed partial homology with the c genome contained in the hybrids. Genotypic influence on chromosome pairing was indicated. Structural chromosome differences and spontaneous chromosome breakage and reunion were suggested as causes for the abnormalities which related to the unbalance of the genotypes. The divergence of the genomes of B. napus and B. oleracea and the need for the qualification of the term secondary association were discussed.Contribution No. J. 673, Research Station, Agriculture Canada, St. Jean, Québec.     

Effects of lignin‐modified Populus tremuloides on soil organic carbon

Several genes in the aspen genome have been modified to generate stem wood with lower lignin content and an altered lignin composition. Lower lignin in wood reduces the time and energy required for pulping. Further, this modification can also increase the allocation of photosynthate to cellulose and total biomass production, potentially increasing CO₂‐sequestration capacity. However, widespread planting of trees with altered lignin content and composition could alter soil organic‐C dynamics in complex ways. To further examine the effects of altered lignin biosynthesis on plant growth and accrual of soil organic C (SOC), we conducted a repeated greenhouse study with four lines of transgenic aspen (Populus tremuloides Michx.) and one wild‐type (control) aspen. Accrual of aspen‐derived SOC was quantified by growing aspen trees (C3 plants) in C4 soil and measuring changes in the natural abundance of δ¹³C. We measured plant growth, biomass, and C content and combined these data with SOC measurements to create C budgets for the plant mesocosms. Lignin modifications resulted in differences in the accrual of aspen‐derived SOC and total mesocosm C, primarily due to differences in biomass between genetically modified lines of aspen. One genetic alteration (low lignin, line 23) was able to perform similarly or better than the wild‐type aspen (control, line 271) without altering SOC. Alterations in lignin structure (S : G ratios) had negative effects on biomass production and SOC formation. The addition of new (aspen‐derived) SOC was proportional to the loss of existing SOC, evidence for a priming effect. The pool of new SOC was related to total plant biomass, suggesting that the effects of lignin modification on SOC are driven by changes in plant growth.     

Use of murine models to detect the allergenicity of genetically modified Lactococcus lactis NZ9000/pNZPNK

By introducing aprN into Lactococcus lactis NZ9000, the genetically modified L. lactis NZ9000/pNZPNK successfully expressed the nattokinase. The safety assessment of this novel strain was based on allergenicity of pepsin digestion stability and murine model serologic identity. Subjecting to the GM strain and host to pepsin digestion, the soluble fractions and cell debris were fast degraded completely. Feeding with ovalbumin resulted in significantly higher production of IgG1 and IgE as compared to that of L. lactis NZ9000/pNZPNK or L. lactis NZ9000. Further, the serum IgG2a level increased dose-dependently at week 2 and induced immune reaction toward Th1 pathway. Secretion of cytokines IL-4 and IL-10 fed with lactococci was significantly lower than that of the OVA group. L. lactis NZ9000/pNZPNK did not increase the proliferation of type 2 helper T cells in spleen or induce allergenicity in BALB/c mice. On the basis of the results, the new GM lactic acid bacterium is regarded as safe to use.     

Direct inoculation of Mycobacterium avium subspecies Paratuberculosis into ileocecal Peyer's patches results in colonization of the intestine in a calf model

The objective of this study was to develop an intestinal model of Mycobacterium avium subspecies paratuberculosis (Map) infection in the calf for evaluation of mucosal pathology and local and systemic immunologic responses. Map was inoculated into Peyer's patches of young calves using a right flank surgical approach in standing calves to exteriorize the ileocecal junction. Inoculum doses ranging from 10(3) to 10(9) colony-forming units of strain K10 Map were injected through the serosal surface into Peyer's patches of the distal ileum near the ileocecal valve. Fecal samples were collected for culture from each calf weekly until termination of the study. Calves were necropsied at 7, 30, 60, and 90 days after infection, when inoculation sites, lymph nodes, spleen, and peripheral blood were collected for evaluation. Ileocecal lymph nodes were consistently colonized by Map in the 10(5) to 10(9) groups. The ileocecal valve was also colonized in 10(7) and 10(9) groups. This correlated with fecal culture results as infected calves intermittently shed Map in their feces throughout the study. Granulomatous lesions with giant cells and acid-fast bacilli at the ileocecal junction, ileocecal lymph nodes, and lamina propria of high-dose animals (10(7) and 10(9)) were identified from each time point. Flow cytometry was used to detect antigen-specific production of interferon-γ and interleukin-4 locally (ileocecal lymph node) and systemically (peripheral blood mononuclear cells), which defined distinct immunologic profiles in low-dose and high-dose calves. This study demonstrates intestinal Map infection via Peyer's patch inoculation, a novel model with many shared features of natural Map infection.     

Dynamics of Moraxella bovis infection and humoral immune response to bovine herpes virus type 1 during a natural outbreak of infectious bovine keratoconjunctivitis in beef calves

Infectious bovine keratoconjunctivitis (IBK) is an acute disease caused by Moraxella bovis (Mb). Several factors may predispose animals to an IBK outbreak; one commonly observed is infection with bovine herpes virus type 1 (BHV-1). The aim of this study was to investigate the dynamics of BHV-1 virus infection and its relation with clinical cases of IBK in weaned calves from a beef herd with a high prevalence of lesions caused by Mb. Sampling was carried out in six stages and included conjunctival swabs for isolating Mb as well as blood samples for identifying antibodies specific for BHV-1. A score for IBK lesions after observing each eye was determined. The findings of this study showed a high prevalence of BHV-1 virus infection (100% of animals were infected at the end of the trial); 67% of animals were culture-positive for Mb, but low rates of clinical IBK (19% of calves affected) were detected at the end of the trial. These results suggest that infection with BHV-1 did not predispose these animals to IBK, and that Mb infection produced clinical and subclinical disease in the absence of BHV-1 co-infection.     

家蚕隐性灰色卵的遗传学研究

本研究室保存的隐性灰色卵是迄今发现的唯一的隐性遗传灰色卵,是与所有灰色卵都不相同的新突变。用实验遗传学方法进行连续检索表明:该灰色卵属第二连锁群的隐性突变基因支配。定名为隐性灰卵(recessive grey egg),基因记号为g~(r-r).     

Optimum blends of different grades of surimi determined by non-linear programming

SUMMARY: The texture and color properties of surimi gels consisting of pollack surimi, golden threadfin-bream surimi, and low-grade hairtail surimi in various ratios were determined based on a mixture design. Surimi gels were produced by heating at 90°C for 20 min with the addition of 2% NaCl. The texture and color properties of blended surimi from various grades can be represented as non-linear functions. Therefore, non-linear programming was found to be appropriate for determining the optimum formulation for surimi products blended from various grades of surimi. About 3.3% to 18.8% of hairtail surimi could be used when blending with high-grade surimi to produce surimi seafood.