Visualization of the effect of a surfactant on the uptake of xenobiotics into plant foliage by confocal laser scanning microscopy

A radiolabelling method is generally used to determine the foliar uptake of xenobiotics. This technique cannot provide any information on the localization of chemicals inside leaf tissues. The influence of an alcohol ethoxylate surfactant on the uptake of three fluorescent dyes, difluorofluorescein (hydrophilic), rhodamine B (moderately lipophilic) and a naphthalimide dye (lipophilic), into the leaves of three contrasting species, bean (Vicia faba), wheat (Triticum aestivum) and cabbage (Brassica oleracea), at 16 h after treatment was measured using a conventional wash‐off method and also visualized in vivo by confocal laser scanning microscopy (CLSM). Whereas the lipophilic dyes showed greater intrinsic uptake than the hydrophilic one, the enhancing effect of the surfactant on uptake was more pronounced for the latter. CLSM revealed that the presence of the surfactant increased the transport of difluorofluorescein into the epidermal cells of bean and wheat leaves, but not cabbage leaves. Rhodamine B showed greatest transcuticular diffusion in all three species, but most of the dye moved into the vacuole of the epidermal cells. The naphthalimide dye was strongly retained by the wax–cuticle layer of all species, even in the presence of the surfactant. CLSM has proven to be an attractive tool for studying xenobiotic diffusion. The results obtained using fluorescent dyes are believed to be applicable to the foliar uptake of herbicides.     

Effect of dietary Schizochytrium microalga oil and fish oil on plasma cholesterol level in rats

The purpose of the study was to test the hypothesis that the dietary oils with different content of n‐3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) affect plasma lipid level in rats in a different degree. The diets with 6% of fish oil (FO) and Schizochytrium microalga oil (SchO; EPA+DHA content in the diets 9.5 + 12.3 and 2.6 + 29.5% of the sum of total fatty acids, respectively) were used; the diet with 6% of safflower oil (high content of n‐6 PUFA linoleic acid, 65.5%; EPA+DHA content 0.7 + 0.9%) was used as a control. The difference between FO and SchO was established only in the case of plasma triacylglycerol (TAG) level: plasma TAG of the FO‐fed rats did not differ from the control rats (p > 0.05), while SchO decreased (p < 0.05) plasma TAG to 46% of the control. On the other hand, FO and SchO decreased (p < 0.05) total plasma cholesterol (TC) in rats in the same extent, to 73% of the control. Regarding the underlying mechanisms for the TC decrease, both SchO and FO up‐regulated hepatic Insig‐1 gene (181 and 133% of the control; p < 0.05), which tended (p = 0.15 and p = 0.19 respectively) to decrease the amount of hepatic nSREBP‐2 protein (61 and 66% of the control). However, neither SchO nor FO influenced hepatic 3‐hydroxy‐3‐methyl‐glutaryl‐CoA reductase gene expression (p > 0.05); SchO (but not FO) increased (p < 0.05) low‐density lipoprotein receptor mRNA in the liver. It was concluded that the decrease of total plasma cholesterol might be caused by an increased cholesterol uptake from plasma into the cells (in the case of SchO), but also by other (in the present study not tested) mechanisms.     

Congenital ocular anomalies and ventricular septal defect in a dromedary camel (Camelus dromedarius).

A 5-wk-old female dromedary camel (Camelus dromedarius) was clinically diagnosed with bilateral corneal dermoids, incomplete congenital cataracts, a left persistent hyaloid artery (PHA), and a ventricular septal defect (VSD). The corneal dermoids were removed by lamellar keratectomy, and vision improved in the left eye. Thirteen months after dermoid surgery, the calf was presented for enlargement of the right eye. Glaucoma was confirmed in the right eye, and corneal fibrosis and cataract were noted in the left eye. Persistence of the VSD was confirmed by cardiac ultrasonography. The calf was euthanized, and necropsy findings confirmed VSD. Histopathologic examination revealed bilateral corneal thinning and fibrosis, cataracts with retrolental fibroplasia, and retinal dysplasia. Additional changes in the right globe were anterior segment dysgenesis, ruptured lens capsule, chronic phacoclastic uveitis, and retinal separation. The PHA was confirmed in the left eye.     

Technical note: utilization of sainfoin by grazing steers and a method for predicting daily gain from small-plot grazing data.

Sainfoin (Onobrychis viciaefolia Scop.) is adapted to the calcareous soils of the southern Great Plains and can provide early season forage that does not induce bloating; however, little is known about performance by ruminants grazing sainfoin. Our objective was to determine the effect of plant growth stage and grazing pressures on potential animal production from sainfoin as predicted from energy intake as a multiple of maintenance. Nitrogen-fertilized (100 kg of N/ha) Renumex sainfoin was grown under irrigation on a Pullman clay loam (fine, mixed, thermic Torretic Paleustoll) near Lubbock, TX. Light (L), medium (M), and heavy (H) grazing pressures were applied with steers grazing sainfoin that was at the bud (B), flower (F), and seed shatter (S) stages of growth. The L, M, and H pressures were grazed to remove 50, 75, and 90% of the standing plant height. Across growth stages, L, M, and H grazing pressures averaged 52, 69, and 87% removal of pregrazed herbage mass. Dry matter intake as a percentage of BW of steers averaged 3.9, 2.8, and 1.7 for L, M, and H grazing pressures. Across growth stages, predicted live weight gain for L, M, and H grazing pressures averaged .86, .67, and .03 kg/d. Our findings indicate that the multiple of maintenance method may be useful for evaluating treatments from small-plot grazing experiments.     

Is the winter period a severe bottleneck of anadromous riverine Arctic charr parr?

Abstract –  Winter growth and survival of wild individually tagged juvenile Arctic charr (1+ age) from a riverine anadromous stock, were studied in a small ice-covered (∼6 months) ground water brook (temperature ∼1 °C) connected to Skibotnelva in subarctic northern Norway. The overall winter survival was estimated to be 68% from late October 2005 to early May 2006. The recaptured charr were not significantly different in initial length or weight compared with the nonrecaptured fish suggesting low size-dependent mortality. The majority (98%) of the recaptured charr showed significant increase in size, with a mean increment of 62% from their initial bodyweight and 12% of the charr parr had more than doubled their weight. The mean specific growth rate was calculated to be slightly lower (0.27) than estimated values from a growth model (∼0.35). In addition, the condition factor increased significantly during the field experiment. These results are the first individual growth data on riverine anadromous Arctic charr parr under natural winter conditions, and indicate that charr can grow relatively fast during periods with low temperature and also that ground water brooks can be good over-wintering habitat for juvenile Arctic charr. These results suggest that the winter period is perhaps a less severe bottleneck than previously recognised for the cold-adapted Arctic charr.     

Diversity of the coat protein-coding region among Ilarvirus isolates infecting hop in Australia

Coat protein (CP) sequences of 17 Ilarvirus isolates were obtained from hops at three farms in Tasmania, Australia. Phylogenetic analysis of these sequences and additional database sequences indicated several Apple mosaic virus (ApMV) isolate clusters distinct from Prunus necrotic ringspot virus (PNRSV): one containing isolates from apple; one containing a single isolate from almond; a third containing Australian hop isolates of the 'apple' serotype and a German isolate of unknown origin; and a fourth containing Australian hop isolates of the 'intermediate' serotype. Isolates from hop, pear and prune from the Czech Republic either formed a fifth grouping, or were divergent members of the 'intermediate' serotype group. Deduced amino acid (aa) residue differences between the coat proteins of the two hop isolate serotype groups were highlighted as possible regions of serological differentiation. No evidence for coinfection of plants with both serotypes was found. Tests of ApMV-infected hop buds using the Shirofugen flowering cherry assay revealed a possible differentiation of the two strains based on hypersensitivity. Because of serological similarities to PNRSV, these viruses have commonly been reported as strains of PNRSV. However, this study shows ilarviruses from Australian hops are strains of ApMV, but distinct from those infecting Malus spp.     

日本金龟子幼虫寄生蜂春黑小土蜂人工繁殖技术研究

以日本金龟子幼虫为繁殖寄主，对春黑小土蜂的人工繁殖技术进行了研究。试验结果表明：土蜂幼虫的发育历期，寄生三龄蛴螬的比二龄蛴螬的平均短3．76d；成茧率高1．87倍。二龄蛴螬繁殖的土蜂80％以上是雄性，三龄蛴螬繁殖的雌性蜂占60％以上。5％蜂蜜水和蔗糖水是成蜂较为理想的营养补充饲料。寄生作用率随接蜂数量的增加而减少。在土蜂产卵高峰期，种内干扰系数最高。单雌平均获卵量和获茧数随更换寄主频次的增加而增加，以每8h更换一次寄主最为适合。