Kinetic disposition of an aqueous formulation of alphacypermethrin applied to the dorsal mid-line of sheep with long wool and its effect on lice

A group of 5 adult Merino sheep with fleeces about 70 mm long (7-months growth of wool) was treated with a topical formulation of the synthetic pyrethroid insecticide, alphacypermethrin, applied to the dorsal mid-line. Insecticide concentrations at the tip, middle and base of wool staples collected from meridians along the back, upper and lower flanks were measured at intervals from 1 to 98 days after treatment. Some movement of the alphacypermethrin from the back to the lower body occurred within 24h after treatment, but despite careful application of the insecticide there was wide variation in the concentration between and within meridians. The majority of the alphacypermethrin remained close to the dorsal mid-line and near the tip of the staple. There were significant differences in the concentration between the tip, middle and base segments of the staples in the back and lower flank meridians (P < 0.05). Despite exposure of the sheep to normal weathering, there was no significant difference in the concentration of alphacypermethrin between samples collected at day 1 or day 98 after treatment (P > 0.05). Numbers of pyrethroid-susceptible lice surviving exposure in vitro for 20 h differed significantly between samples collected at different times after treatment (P < 0.05). The numbers of lice surviving in samples collected within 28 days after treatment tended to be lower than in those collected from 28 to 98 days but, in some samples, regardless of time after treatment, lice survived for 20 h in wool taken from parts of the fleece that contained high concentrations of alphacypermethrin.     

β-structure from the microfibillar proteins of Merino wool

The β-structure of S-caboxymethyl derivatives of microfibrillar proteins isolated from Merino wool was investigated by X-ray diffraction for comparison with the structur of β-keratin. The S-carboxymethylated microfibrillar proteins(SCMKA) w well-oriented β-films of SCMKA weer obtained by stretching the SCMKA cast films in steam up to about 300% extesnsion. It was found that the reflections in β-pattern of SCMKA may be indexed on a pseudo-orthorhombic unit cell with a =0.94 nm, b = 0.66 nm and c = nm, where the ab, and c axes are in the direction of the interchain hydrogen bonding, the main chain(fibre axis) and the side chain, respectively. The unit cell dimesnions evaluated for SCMKA were almost the same as those for β-keratin, suggeting that few peptide sequences containing S-carboxymethyl cystine may be involved in the formation of β-structure from SCMKA.     

The segregation of lambs into ‘responders’ and ‘non-responders’: Response to vaccination with irradiated Trichostrongylus colubriformis larvae before weaning

Random bred Merino ram and ewe lambs were vaccinated at 1, 2 and/or 3 months of age with irradiated T. colubriformis larvae. An exponentially increasing challenge of normal larvae was given to all groups including unvaccinated controls commencing at 1 month of age. The results, based on faecal egg counts, showed a dissociation into animals which responded to vaccination (geometric mean egg count 441) and those which did not (geometric mean egg count 1567). The proportion of responders was greatest in groups first vaccinated at the earliest age (1 month). Wool growth and liveweight gains showed severe depression corresponding to peak egg counts, however, responders were less affected than non-responders. There was no correlation between haemoglobin type and resistance to challenge. Faecal egg counts after impulse challenge with 10,000 normal larvae given at about 6$\text{1}\text{2}$ months of age showed a significant ranked correlation with those obtained during the primary exponential challenge. These results confirm that a proportion of young lambs respond to vaccination with irradiated larvae, and that genetically-determined factors are implicated in the ability of animals to respond to vaccination at an early age.     

不同材质微芯片内细胞生长状态分析

微系统技术在细胞生物学方面的研究中已得到广泛应用。了解细胞在微系统芯片内的生长状态,对于利用微系统技术进行细胞研究有重要的指导意义。玻璃和聚二甲基硅氧烷（polydimethylsiloxane,PDMS）是目前制作细胞培养微芯片的主要材料。通过向以二者为基底材料制作的细胞培养微芯片内导入内皮细胞进行培养,利用实验室构建的细胞成像分析系统观察和分析细胞在不同基底材料的芯片内5天的增殖情况,同时研究了基底材料的预处理方法以及培养基对细胞增殖的影响。     

角蛋白HGTP及其对羊毛发育的影响

羊毛的主要成分是角蛋白,其组分高甘氨酸-酪氨酸蛋白(HGTP)家族成员KAP6、KAP7和KAP8基因表达对羊毛细度和弯曲等特性具有重要影响。本文从羊毛的组成、角蛋白的生物学特征以及HGTP基因定位和表达对细度的影响等方面进行了综述,旨在为羊毛发育调控研究提供理论参考。     

Concentration of Virus from Water by Electro-Osmosis and Forced-Flow Electrophoresis. II. Improvement of Methodology and Application to Tap Water

The ability of the Canalco Model CF-3 electro-osmosis (EO) apparatus to concentrate viruses from artificially seeded distilled water was improved. Modification of the physical arrangement of the equipment allowed for a 10–25 fold increase in concentration efficiency and a concomitant decrease in the process time. The major improvements involved modifications of the cell arrangement (which increased the membrane transport area), a change in the salt replenishing solution and the use of different membranes of higher flux. Viruses concentrated by E0 from seeded tap water resulted in lower recoveries when compared to distilled water. The lower yields were probably due to instability or aggregation of the agents in the menstruum and not directly related to the physical apparatus. Under the conditions used, one could detect virus at levels as low as 0.01 plaque forming units (PFU) per ml of initial input. The efficacy of a modification of the Canalco forced-flow electrophoretic (FFE) system was also evaluated. The maximum potential was applied with a constant value for pump rates. A 6-fold concentration of virus and a 12-fold decrease in water volume was obtained.     

Coarser wool is not a necessary consequence of sheep aging: allometric relationship between fibre diameter and fleece-free liveweight of Saxon Merino sheep

The mean fibre diameter (MFD) of wool is the primary determinant of price, processing performance and textile quality. This study determines the primary influences on MFD as Saxon Merino sheep age, by allometrically relating MFD to fleece-free liveweight (FFLwt). In total, 79 sheep were grazed in combinations of three stocking rates and two grazing systems (GS: sheep only; mixed with Angora goats) and studied over 3 years. Measurements were made over 14 consecutive periods (Segments), including segments of FFLwt gain or FFLwt loss. Using shearing and liveweight records and dye-bands on wool, the FFLwt and average daily gain (ADG) of each sheep were determined for each segment. The mean and range in key measurements were as follows: FFLwt, 40.1 (23.1 to 64.1) kg; MFD, 18.8 (12.7 to 25.8) μm. A random coefficient restricted maximum likelihood (REML) regression mixed model was developed to relate the logarithm of MFD to the logarithm of FFLwt and other effects. The model can be written in the form of β(A) is a random animal effect, γ(Segment.Plot) a random effect associated with Segment.plot combinations, and κ a constant that depends on GS, random animal effects, random Segment.plot combination effects, Segment and ADG. Thus, MFD was allometrically related to the cube root of FFLwt over seasons and years for sheep, but to the square root of FFLwt for sheep grazed with goats. The result for sheep grazed alone accords with a primary response being that the allocation of nutrients towards the cross-sectional growth of wool follicles is proportional to the changes in the skin surface area arising from changes in the size of the sheep. The proportionality constant varied systematically with ADG, and in sheep only grazing, was about 5 when sheep lost 100 g/day and about 6 when sheep gained 100 g/day. The proportionality constant did not systematically change with chronological age. The variation in the allometric coefficient between individual sheep indicates that some sheep were more sensitive to changes in FFLwt than other sheep. Key practical implications include the following: (a) the reporting of systematic increases in MFD with age is likely to be a consequence of allowing sheep to increase in size during shearing intervals as they age; (b) comparisons of MFD between sheep are more likely to have a biological basis when standardised to a common FFLwt and not just to a common age; (c) wool quality (MFD, staple strength) are most likely to be optimised in management systems that maintain constant FFLwt of adult sheep within and between years.     

Functionalization of poly(amidoamine) dendrimer‐based nano‐architectures using a naphthalimide derivative and their fluorescent,dyeing and antimicrobial properties on wool fibers

Novel naphthalimide–poly(amidoamine) dendrimer fluorescent dyes were synthesized, and their structures were identified and confirmed using different characterization methods such as Fourier transform infrared, ¹H NMR, ¹³C NMR, differential scanning calorimetry, elemental analysis and UV–vis spectroscopy. The spectrophotometric studies demonstrated absorption maxima (λ_max) and extinction coefficient (ε_max) values in the ranges of 429–438 nm and 25,635–88,618 L/mol/cm, respectively. The dyeing, fastness and antimicrobial properties of dyed wool fibers were examined. Colorimetric measurements demonstrated a greenish‐yellow hue with remarkable fluorescence intensity on dyed wool. Although the fastness properties of naphthalimide dye on wool fibers were poor/moderate, color fastness was appreciably improved through modification of the dye using dendrimers. The results revealed that the newly synthesized dyes are potent antimicrobial agents on wool fibers. Overall, it was deduced that poly(amidoamine) (PAMAM) dendrimers could be exploited as a promising tool in tailoring the different properties of naphthalimide dyes, being suitable for dyeing and antimicrobial finishing agents for wool fibers. Copyright © 2015 John Wiley & Sons, Ltd.     

Effect of Water Content on Glass Transition and Protein Aggregation of Whey Protein Powders During Short-Term Storage

The objectives of this study were to investigate the moisture-induced protein aggregation of whey protein powders and to elucidate the relationship of protein stability with respect to water content and glass transition. Three whey protein powder types were studied: whey protein isolate (WPI), whey protein hydrolysates (WPH), and beta-lactoglobulin (BLG). The water sorption isotherms were determined at 23 and 45°C, and they fit the Guggenheim–Andersson–DeBoer (GAB) model well. Glass transition was determined by differential scanning calorimeter (DSC). The heat capacity changes of WPI and BLG during glass transition were small (0.1 to 0.2 Jg⁻¹ °C⁻¹), and the glass transition temperature (T _g) could not be detected for all samples. An increase in water content in the range of 7 to 16% caused a decrease in T _g from 119 down to 75°C for WPI, and a decrease from 93 to 47°C for WPH. Protein aggregation after 2 weeks’ storage was measured by the increase in insoluble aggregates and change in soluble protein fractions. For WPI and BLG, no protein aggregation was observed over the range of 0 to 85% RH, whereas for WPH, ∼50% of proteins became insoluble after storage at 23°C and 85% RH or at 45°C and ≥73% RH, caused mainly by the formation of intermolecular disulfide bonds. This suggests that, at increased water content, a decrease in the T _g of whey protein powders results in a dramatic increase in the mobility of protein molecules, leading to protein aggregation in short-term storage.