Characterization and sorption ability of wool powder

This work focused on the characterisation of wool powders and their sorption capacity for dyes and metal ions. It provides new information to the field of wool and the potential use of wool to sorb contaminants from wastewater. It also suggests a new use for inferior and waste wool.

Fabricating and characterising silk powder for biomedical and sorption applications

This research developed a milling technology for ultrafine silk particles and designed novel biocompatible and biodegradable silk composites for repairing hard tissue defects. It also demonstrated high and rapid reversible ion binding properties of silk particles and thereby opened up their application opportunities as advanced green sorbents.

Maternal effects in the Zebra Finch : a model mother reviewed

Birds are a particularly good group with which to examine the importance of maternal effects, as parental contributions can be relatively easily quantified compared with other groups. There have undoubtedly been more studies on maternal effects in the Zebra Finch than any other single bird species. Studies of this species have examined the importance of maternal effects mediated through sex allocation, size, nutrients and hormones of of eggs, incubation behaviour and provisioning levels. A synthesis of all of this work illustrates some contrasting results (e.g. many high-profile results have failed to be replicated), some very common patterns (e.g. investment shifts through the laying sequence), and potentially interesting and complex interactions between traits (e.g. between sex of offspring and hormonal profiles of eggs). This extensive collection of work on the Zebra Finch provides useful general insight into the patterns of maternal investment in birds and the effects on offspring phenotype. However, we caution that the literature is probably littered with studies that have overemphasised the importance of some maternal effects and recent studies have highlighted analytical and logical flaws that have probably led to misplaced confidence in some of the findings reported to date. Finally, it is worth considering that the bulk of the literature is based on studies of captive domesticated birds and ecological and physiological data from individuals in the wild is currently lacking. The biological relevance of maternal effects documented in this model species is therefore unclear.

Study on the antibacterial properties of superfine wool powder part I : experiment

The superfine wool-powder was prepared by ball and jet milling. According to FZ/T 01021-92 method the bacteriostatic property of the wool-powder was tested. The results showed that wool-powder had excellent antibacterial activity against Escherichia coli (E. coli) and Staphylococcus (MRSA), and the antibacterial rate of E. coli could reach 85% and the MRSA could exceed 70%. The IR spectroscopy and X-ray diffraction analysis were used to discuss the antibacterial properties of superfine wool-powder.

Stimulatory effects of egg-laying hormone and gonadotropin-releasing hormone on reproduction of the tropical abalone, Haliotis asinina linnaeus

Egg-laying hormone (ELH) is a neuropeptide hormone that stimulates ovulation of gastropods, including Aplysia californica and Lymnaea stagnalis. Other neuropeptides, gonadotropin releasing hormones (GnRHs), also play important roles in controlling reproduction in both vertebrates and invertebrates. In the current study, the effects of abalone ELH (aELH) and several GnRHs on somatic growth, sex differentiation, gonad maturation, and spawning of Haliotis asinina were investigated in 3 experiments. In experiment 1, groups of 4-mo-old juveniles (11.8 ±  0.03 mm shell length (SL) and 0.33 ± 0.04 g body weight (BW)) were injected with aELH and GnRHs, including buserelin (mammalian GnRH analogue), octopus GnRH (octGnRH), and tunicate GnRH-I (tGnRH-I), at doses of 20 ng/g BW and 200 ng/g BW. The aELH induced early sex differentiation with a bias toward females, but with normal somatic growth, whereas the different isoforms of GnRH had no effect on sexual differentiation or somatic growth. In experiment 2, groups of 1-y-old-abalone (SL, 4.04 ± 0.02 cm; BW, 20.15 ± 0.25 g) were injected with aELH and the 3 isoforms of GnRH including buserelin, octGnRH, and lamprey GnRH (1GnRH-I) at doses of 500 ng/g BW and 1,000 ng/g BW, and all produced stimulatory effects. For each peptide treatment, the gonads reached full maturation within 5- 6 wk and spawning occurred, whereas control groups took 8 wk to reach maturity. In experiment 3, injections of ripe abalone with aELH stimulated spawning of both sexes in a dose-dependent manner. Buserelin had a lesser effect on inducing spawning, and octGnRH had no apparent effect. The gametes released from induced spawnings by aELH and GnRH showed normal fertilization and development of larvae. Altogether, these findings provide further knowledge on manipulating abalone reproduction, which is important in improving abalone aquaculture.

Dyeing properties of PVA/superfine wool powder blend filaments

Polyvinyl alcohol/superfine wool powder blend filaments were prepared to improve teh dyeing properties of polyvinyl alcohol (PVA) filaments. The average size of superfine wool powder was 2.01 um. SEM microphotgraphs showed good compatibility between superfine wool powder and PVA matrix. The PVA/superfine wool powder blend solution showed good spinningability. With the incerease in superfine wool powder content, the dye uptake, a* value and K/S value of PVA/superfine wool powder blend filaments increased steadily. It was worth noting that the dyeing properties of blend filaments were almost similar with that of superfine wool powder when powder content was 33.3%

Protein fibre powder

Soft viscoelastic fibres, which are very difficult to grind, can be processed to produce ultrafine particles. This work has created knowledge about new applications of these natural structural proteins. The high reactivity generated through creation of large surface area has been used to design advanced devices and applications. For example particles have been studied for separation of harmful ions from waste water and applied to develop porous composite materials to grow bones to repair critical bone defects.

Chromatic interaction between egg pigmentation and skin chromatophores in the nuptial coloration of female two-spotted gobies

In two-spotted gobies (Gobiusculus flavescens Fabricius 1779), females develop an orange belly as they approach sexual maturity. Bright belly coloration is preferred by males and has been suggested to act as a female ornament. This coloration is unusual in that it originates partly from pigmentation of the abdominal skin but also from strongly pigmented gonads directly visible through the skin. In addition, females have been observed to temporarily become more colourful during courtship and competition. To understand how gonad and skin pigmentation interact in this nuptial coloration, the potential for colour modification via regulation of skin chromatophores was investigated. Noradrenaline caused aggregation of chromatophore pigment and was used to experimentally reduce the contribution of skin chromatophores to the nuptial coloration. Chromatophore pigment aggregation caused bellies to become less colourful and abdominal skin biopsies to become less colourful and more transparent. There was a strong positive relationship between belly coloration and the coloration of the underlying gonads. This shows that belly coloration honestly reflects egg pigmentation, mainly because the transparency of the abdominal skin allows other fish to see the gonads directly. Interestingly, when noradrenaline caused pigment to aggregate and thereby increased the transparency of the skin, the relationship between belly and gonad coloration weakened. We conclude that female G. flavescens have a potential to use skin chromatophores to rapidly alter their nuptial coloration, thereby affecting the efficacy with which information about gonad coloration is conveyed.

Does female nuptial coloration reflect egg carotenoids and clutch quality in the Two-Spotted Goby (Gobiusculus flavescens, Gobiidae)?

Summary

1 - Carotenoid-based ornamentation has often been suggested to signal mate quality, and species with such ornaments have frequently been used in studies of sexual selection.

2 - Female Gobiusculus flavescens (Two-Spotted Goby) develop colourful orange bellies during the breeding season. Belly coloration varies among mature females, and previous work has shown that nest-holding males prefer females with more colourful bellies. Because males invest heavily in offspring during incubation, the evolution of this preference can be explained if colourful females provide males with eggs of higher quality.

3 - We tested this hypothesis by allowing males to spawn with ‘colourful’ and ‘drab’ females and comparing parameters including egg carotenoid concentration, clutch size, hatchability and larval viability between groups. We also investigated relationships between egg carotenoid concentration and clutch quality parameters.

4 - Eggs from colourful females had significantly higher concentrations of total carotenoids than drab females, and photographically quantified belly coloration was a good predictor of egg carotenoid concentration.

5 - Colourful females produced slightly larger clutches, but female belly coloration was not related to any measure of clutch quality. In addition, there were no significant relationships between egg carotenoids and clutch quality. Females with high levels of egg carotenoids spawned slightly earlier, however, possibly because they were more ready to spawn or because of male mate choice.

6 - Our results call into question the generality of a causal link between egg carotenoids and offspring quality.

Formation and dissolution of hen egg white lysozyme amyloid fibrils in protic ionic liquids

The formation of amyloid fibrils from non-disease-related proteins demonstrates that any protein can adopt this “rogue” form; we show that it is possible to use protic ionic liquids to fibrilize hen egg white lysozyme, and then subsequently to dissolve the fibrils with up to 72% restoration of enzymatic activity.

Structure–energy relations in hen egg white lysozyme observed during refolding from a quenched unfolded state

We use infrared spectroscopy to study the evolution of protein folding intermediate structures on arbitrarily slow time scales by rapidly quenching thermally unfolded hen egg white lysozyme in a glassy matrix, followed by reheating of the protein to refold; upon comparison with differential scanning calorimetric experiments, low-temperature structural changes that precede the formation of energetic native contacts are revealed.

Protein fibre powder and new applications

Protein fibers such as silk and wool have been used as textile fibers for centuries. It is only in recent years that these fibers have been converted into fine powder forms for non-textile applications. This presentation will cover our recent research in protein fiber powders. Ultra-fine powders from different protein fibers have been produced using a combination of media and non media milling techniques. New application examples of these fine powders are discussed. These applications include hybrid fibers combining the advantages of natural and synthetic polymer fibers, tissue engineering composite scaffolds with enhanced biomechanical properties, and metal ion absorption.

From food to offspring down : tissue-specific discrimination and turn-over of stable isotopes in herbivorous waterbirds and other avian foraging guilds

Isotopic discrimination and turn-over are fundamental to the application of stable isotope ecology in animals. However, detailed information for specific tissues and species are widely lacking, notably for herbivorous species. We provide details on tissue-specific carbon and nitrogen discrimination and turn-over times from food to blood, feathers, claws, egg tissues and offspring down feathers in four species of herbivorous waterbirds. Source-to-tissue discrimination factors for carbon (δ¹³C) and nitrogen stable isotope ratios (δ¹⁵N) showed little variation across species but varied between tissues. Apparent discrimination factors ranged between −0.5 to 2.5‰ for δ¹³C and 2.8 to 5.2‰ for δ¹⁵N, and were more similar between blood components than between keratinous tissues or egg tissue. Comparing these results with published data from other species we found no effect of foraging guild on discrimination factors for carbon but a significant foraging-guild effect for nitrogen discrimination factors.

Turn-over of δ¹³C in tissues was most rapid in blood plasma, with a half-life of 4.3 d, whereas δ¹³C in blood cells had a half-life of approximately 32 d. Turn-over times for albumen and yolk in laying females were similar to those of blood plasma, at 3.2 and 6.0 d respectively. Within yolk, we found decreasing half-life times of δ¹³C from inner yolk (13.3 d) to outer yolk (3.1 d), related to the temporal pattern of tissue formation.

We found similarities in tissue-specific turn-over times across all avian species studied to date. Yet, while generalities regarding discrimination factors and tissue turn-over times can be made, a large amount of variation remains unexplained.