Donor life stage influences juvenile American eel Anguilla rostrata attraction to conspecific chemical cues.

The present study investigated the potential role of conspecific chemical cues in inland juvenile American eel Anguilla rostrata migrations by assessing glass eel and 1 year old elver affinities to elver washings, and elver affinity to adult yellow eel washings. In two-choice maze assays, glass eels were attracted to elver washings, but elvers were neither attracted to nor repulsed by multiple concentrations of elver washings or to yellow eel washings. These results suggest that A. rostrata responses to chemical cues may be life-stage dependent and that glass eels moving inland may use the odour of the previous year class as information to guide migration. The role of chemical cues and olfaction in eel migrations warrants further investigation as a potential restoration tool.

Effects of supplementing pregnant heifers with methionine or melatonin on the anatomy and other characteristics of their lateral hind claws.

Three groups of four primiparous Holstein-Friesian heifers were fed throughout pregnancy either a control diet or that diet supplemented with either 5 to 6 g per day of rumen-protected intestinally available methionine or 25 mg melatonin. They were euthanased three days after calving. The dietary supplements had no effect on the impression hardness or the concentrations of cysteine and methionine in samples of claw horn collected from a range of sites, or on the areas of erosion in the sole and heel. Significant differences were recorded for the hardness of the horn in the order wall >sole >heel. These differences were associated with higher concentrations of cysteine and lower concentrations of methionine in samples of horn from the dorsal wall than in samples from the prebulbar region of the sole. There were no significant differences attributable to the dietary supplements in the soft tissue anatomy of the solear dermis and epidermis.

The action of trenbolone acetate, a synthetic anabolic steroid, on ovarian function in the guinea pig.

The action of trenbolone acetate, a synthetic anabolic steroid, on ovarian function was investigated in the guinea pig. Certain comparisons were made with testosterone, the naturally occurring androgen, administered as the phenylpropionate ester. Two milligrams trenbolone acetate per kg given subcutaneously on alternate days for 20 days blocked oestrous cyclicity and ovulation in 9 of 10 animals. A similar effect was shown by 2.2 mg of testosterone phenylpropionate. Treatment of trenbolone acetate-treated animals with exogenous gonadotrophins suggested that the production of follicle-stimulating hormone had been suppressed. Signs of abnormality were seen in the livers of animals receiving 2 mg trenbolone acetate and 2.2 mg testosterone phenylpropionate.

Effect of hexoestrol on the response of finishing steers to treatment with trenbolone acetate.

The relative effectiveness of implanting 300 mg trenbolone acetate alone or in combination with either 15, 30 or 45 mg hexoestrol was studied in three 90-day experiments using 64 Friesian steers. In experiment 1 hexoestrol was shown to improve live-weight gain and efficiency of feed conversion in steers implanted with trenbolone acetate. In experiments 2 and 3 trenbolone acetate in combination with 30 mg hexoestrol gave a better growth response than when combined with either 15 or 45 mg. However, in experiment 3 trenbolone acetate plus 15 mg hexoestrol was shown to improve live-weight gain by about 36 per cent compared with untreated controls. In experiment 2 small differences between treated groups in mean values for plasma urea, serum albumin, plasma glucose and free fatty acids were recorded.

Performance, blood and carcase characteristics of finishing steers treated with trenbolone acetate and hexoestrol.

Twenty British Friesian steers were divided into four uniform groups and either not treated or implanted with hexoestrol, trenbolone acetate, or hexoestrol plus trenbolone acetate. Hexoestrol was given 90 days and trenbolone acetate 70 days, before slaughter. Animals in the treatment groups grew significantly faster, converted food to live-weight gain more effciently faster, converted food to live-weight gain more efficiently and had lower levels of plasma urea and to a lesser extent serum albumin than untreated controls for the final 70 days before slaughter. The combined treatment of hexoestrol plus trenbolone acetate produced more pronounced effects than either compound given alone. Steers treated with hexoestrol had significantly greater levels of serum growth hormone than steers implanted with trenbolone acetate alone or untreated controls, but the treatments had no significant effect on levels of plasma glucose, free fatty acids or serum insulin. Carcase conformation and fat cover assessed subjectively did not differ between treated and control animals but killing out percentage was generally higher in all treatment groups.

In vitro methodology, hormonal and nutritional effects and fibre production in isolated ovine and caprine anagen hair follicles.

Mammalian hair follicles are complex multicellular structures in the skin, which produce hair fibre under the influence of locally produced and systemic signalling systems. Investigation to determine mechanisms of regulation, follicular responses and the importance of nutritional supply have utilised a number of in vivo and in vitro approaches. Included in these are studies on isolated intact anagen secondary follicles singly or in groups with incubation in culture medium. These utilise techniques developed for investigation of follicles from human skin. Results from selected studies reviewed here demonstrate differences in capacity for hair growth and protein synthesis between secondary follicles from Angora and cashmere-bearing goats. Mohair follicles were shown to exhibit faster hair shaft elongation both in vivo and in vitro, to have greater DNA content per follicle and to deposit significantly more protein per follicle and per unit of DNA. Incubation of anagen mohair and cashmere follicles in the presence of melatonin or prolactin showed positive responses in hair shaft growth and protein synthesis to both signalling molecules. This result indicated directly acting effects on the follicle in addition to any indirect effects arising at a whole animal level in response to, for example, variation in photoperiod. Similarly, epidermal growth factor was shown to alter elongation and protein synthesis in mohair follicles and to produce, at higher concentration, club hair structures similar to effects observed in other species. The vitamin biotin was shown to be important in maintaining viability of isolated sheep secondary hair follicles where supplementation increased the proportion continuing to grow. Effects on growth and apparent protein synthesis suggested comparatively lesser effects on follicles, which remained viable. Histology on follicles indicated effects of biotin deficiency in reducing proliferation of basal keratinocytes. The final study, included in this review, demonstrated that supply of the essential sulphur-containing amino acid l-methionine was necessary to maintain the viability and growth of mohair follicles. l-cysteine was not required in the presence of l-methionine, although there was evidence of an optimisation when both amino acids were present in adequate concentrations. Consideration is given to the importance of transport mechanisms and capacity to utilise absorbed nutrients when considering optimising nutritional supply to individual follicles. These may then provide targets for attainment in applied nutrition of animals in vivo.

Fundamental hair follicle biology and fine fibre production in animals.

Hair 'fine' fibre is an important commercial product of farmed and certain wild animal species. The fibre is produced in follicles embedded in skin. These have properties in common with other tissues of the integument and have importance in determining yield and quality of fibre. Means of understanding and improving these characteristics are informed by knowledge of integumental and follicle biology. This paper reviews contemporary information that identifies the major fibre-producing species and their production characteristic. It surveys knowledge describing fundamental biology of the integument and considers information derived for the hair follicle from studies on a number of species including genetically modified mice. It identifies the composition of the follicle and describes components and interrelationships between epidermal hair-fibre producing epidermis and fibroblast- and connective tissue-containing dermis. The structure of different primary and secondary follicle types, and associated structures, are described. Focus is given to the alterations in anatomy and in behaviour from active to inactive state, which occurs during the hair follicle cycle. Information is provided on the anatomical substructures (hair medulla, cortex, cuticles and supporting sheaths and dermal papilla), cellular and extracellular composition, and adhesion and chemical signalling systems, which regulate development from the early embryo to post-natal state and subsequent cycling. Such signalling involves the dermis and its specialist fibroblasts, which secrete signalling molecules, which along with those from local epidermis and systemic sources, largely determine structure and function of epidermal cells. Such chemical signalling typically includes endocrine-, paracrine-, autocrine- and juxtacrine-acting molecules and interactions with their receptors located on cell membranes or intracellularly with transduction of message mediated by transcription factors at gene level. Important hormones and growth factors and inhibitors regulating morphogenic and/or mitogenic activity are identified. These mediate mechanisms associated with presence or absence in skin and development of patterning for primary or secondary follicles. Reference is made to deposition of individual keratins and keratin-associated proteins in follicle sub-structures and to fibre properties such as length, diameter, medullation, crimp and lustre. Pre- and post-natal regulation of pigmentation by melanocytes is reviewed. Brief attention is given to genomic and non-genomic variation and impact on the phenotypes expressed and the role of regulatory gene products as potential molecular markers for selection of superior animals. The importance of nutrients in providing substrates for follicular structures and enzymes and in molecules facilitating gene expression is also considered.

Biomechanical comparison of the track start and the modified one-handed track start in competitive swimming: an intervention study.

This study compared the conventional track and a new one-handed track start in elite age group swimmers to determine if the new technique had biomechanical implications on dive performance. Five male and seven female GB national qualifiers participated (mean +/- SD: age 16.7 +/- 1.9 years, stretched stature 1.76 +/- 0.8 m, body mass 67.4 +/- 7.9 kg) and were assigned to a control group (n = 6) or an intervention group (n = 6) that learned the new one handed dive technique. All swimmers underwent a 4-week intervention comprising 12 +/- 3 thirty-minute training sessions. Video cameras synchronized with an audible signal and timing suite captured temporal and kinematic data. A portable force plate and load cell handrail mounted to a swim starting block collected force data over 3 trials of each technique. A MANCOVA identified Block Time (BT), Flight Time (FT), Peak Horizontal Force of the lower limbs (PHF) and Horizontal Velocity at Take-off (Vx) as covariates. During the 10-m swim trial, significant differences were found in Time to 10 m (TT10m), Total Time (TT), Peak Vertical Force (PVF), Flight Distance (FD), and Horizontal Velocity at Take-off (Vx) (p < .05). Results indicated that the conventional track start method was faster over 10 m, and therefore may be seen as a superior start after a short intervention. During training, swimmers and coaches should focus on the most statistically significant dive performance variables: peak horizontal force and velocity at take-off, block and flight time.

Single-photon transition moments in excited states of spherical-top molecules.

Single-photon transition moments for overtone states of triply degenerate modes of spherical-top molecules applicable to multiple-photon dynamics calculations are derived for zeroth- and first-order theories. In each case the total transition strength for excitation out of a given angular momentum state is in agreement with well-known results for the triply degenerate oscillator. In contrast with recently published results, this work shows that all strongly allowed multiple-photon pathways do occur.

Comparison of multiple-photon excitation models.

Two recent detailed models of multiple-photon excitation in SF(6) are compared. By performing equivalent vibration-rotation calculations using the two different basis sets, we have found that the results are in complete agreement. Rotational effects in both cases completely overshadow the vibrational structure, making a triply degenerate anharmonic oscillator model sufficient for describing multiple-photon excitation in SF(6).

Growth and viability of secondary hair follicles of the Angora goat cultured in vitro.

The viability of isolated secondary anagen hair follicles from Angora goats was studied in an in vitro tissue culture system. Intact hair follicles were isolated from the dermal layer singly or in groups using watchmakers' forceps under a dissecting microscope following removal of both the epidermis at the basal layer and subcutaneous fat layers using a scalpel blade. The connective tissue sheath surrounding the follicle and the dermal papilla in the bulb were left intact. The isolated follicles were maintained floating in supplemented Williams E medium and showed significant increases in hair shaft length over 96 h. The viability of the cultured hair follicles was verified by the findings that (1) the rate of hair shaft elongation was similar to that occurring in vivo; (2) the pattern of DNA synthesis observed by autoradiography of [methyl-3H]thymidine uptake was maintained in the isolated follicles throughout culture; (3) the ATP content was significantly higher in growing follicles compared with that observed in freshly isolated follicles; and (4) Feulgen-stained preparations of fresh and maintained hair follicles confirmed the retention of mitotic activity in the matrix cells of the bulb for a maximum of 120 h of maintenance.

Growth of secondary hair follicles of the Cashmere goat in vitro and their response to prolactin and melatonin.

The isolation and viability in vitro of anagen secondary hair follicles of the Cashmere goat were studied. Isolated hair follicles were used to determine the effects on hair shaft elongation, of prolactin and melatonin, hormones considered to influence hair follicle growth and activity in vivo. Intact hair follicles were isolated from the dermal layer of the skin singly or in groups using watchmakers' forceps under a dissecting microscope. The isolated follicles were maintained floating in Williams E medium. The medium was supplemented with 1 of 6 concentrations of ovine prolactin (0, 50, 200, 400, 800 and 4000 micrograms/l) for the culture of hair follicles isolated during July and August, and with 1 of 5 concentrations of melatonin (0, 50, 150, 300, 600 ng/l) for the culture of hair follicles isolated during September and October. There was clear evidence of DNA synthesis, observed by autoradiography, in matrix cells of freshly isolated follicles incubated for 6 h in the presence of [methyl-3H]-thymidine. Similar measurements after 96 h of maintenance indicated a marked reduction in the incorporation of [methyl-3H]-thymidine in matrix cells of the follicles studied. Prolactin and melatonin were shown to have a stimulating effect on hair shaft elongation of secondary follicles during 24 h periods of measurement and cumulatively over 120 h. Maximum hair follicle growth was observed in follicles exposed to 400 micrograms/l of prolactin and follicles exposed to 300 ng/l of melatonin. The number of follicles remaining viable during each 24 h measuring period was not affected by prolactin, but was significantly reduced by melatonin treatment after 96 h of maintenance.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer processing of spectrograms for absolute intensities.

A computer program was developed to process photographically recorded spectra for absolute intensity. Test and calibration films are subjected to densitometric scans that provide digitally recorded densities on magnetic tapes. The nonlinear calibration data are fitted by least-squares cubic polynomials to yield a good approximation to the monochromatic H&D curves for commonly used emulsions (2475 recording film, Royal-X, Tri-X, 4-X). Several test cases were made. Results of these cases show that the machine processed absolute intensities are accurate to within 15%o. Arbitrarily raising the sensitivity threshold by 0.1 density units above gross fog yields cubic polynomial fits to the H&D curves that are radiometrically accurate within 10%. In addition, curves of gamma vs wavelength for 2475, Tri-X, and 4-X emulsions were made. These data show slight evidence of the photographic Purkinje effect in the 2475 emulsion.

Effects of metals and arsenic on riparian communities in southwest Montana.

: Concentrations of metals and arsenic in floodplain soils of Silver Bow Creek and the upper Clark Fork River in southwest Montana were related to phytotoxic responses by individual plants in laboratory experiments, vegetative community structure and composition in the field and wildlife habitat. Samples collected from barren or very sparsely vegetated mixed mine tailings and alluvium deposits (slickens) in the floodplains along Silver Bow Creek and the Clark Fork River had concentrations of As, Cd, Cu, Pb and Zn that were significantly elevated relative to reference sites. Laboratory phytotoxicity tests demonstrated severe and rapid effects of the elevated concentrations of metals and As on hybrid poplar and standard test species (alfalfa, lettuce and wheat): growth inhibition of hybrid poplars was nearly 100% and of standard test species ≥75%. Vegetation community measurements revealed that slickens have replaced riparian forest, shrub, hay fields and pasture land; in doing so, the slickens have reduced both the compositional and structural heterogeneity of the riparian habitat. This reduction in habitat complexity has reduced the capacity of the area to provide a diversity of suitable wildlife habitat.

Improvement of the nutritive value of soybean meal by protease and alpha-galactosidase treatment in broiler cockerels and broiler chicks.

1. Tube-fed broiler cockerels were used in three experiments to measure the effect of different enzyme treatments on true metabolisable energy (TME) and true nitrogen digestibility (TND) of commercial solvent-extracted, heat-treated soybean meal (SBM). 2. In experiment 1, proteases P2 and P3 (from Aspergillus niger) and alpha-galactosidase (from A. oryzae) improved TME and TND while protease P1 (from Bacillus subtilis) had little effect. The effects of enzyme treatment were similar whether treatment was applied by pre-incubation of enzymes (proteases P1, P2 and P3, 1.0 g/kg; alpha-galactosidase, 0.1 g/kg) with SBM for 2 h at 50 degrees C or by simple mixing of enzymes (proteases P1, P2 and P3, 0.25 g/kg; alpha-galactosidase, 0.1 g/kg) with SBM prior to feeding. 3. In experiment 2, the effects of mixing SBM with each of protease P1 (0 or 0.25 g/kg), protease P3 (0 or 0.25 g/kg) or alpha-galactosidase (0 or 0.1 g/kg) alone or in all possible combinations were studied. Effects of protease P1 were limited, but protease P3 and alpha-galactosidase improved TME and TND. There were significant interactions between protease P3 and alpha-galactosidase for both TME and TND; the response when enzymes were applied together was less than that expected from application of the enzyme preparations individually. 4. In experiment 3, the effect of varying the concentration of protease P3 (0, 0.1, 0.25 and 1.0 g/kg SBM dry matter) and alpha-galactosidase (0, 0.025, 0.0625 and 0.25 g/kg SBM dry matter) mixed with SBM alone or in all possible combinations of protease P3 and alpha-galactosidase were assessed. Increases in TME and TND for both enzymes were non-linear with the greatest response occurring at the lowest concentration of each enzyme. There were also interactions between the two enzyme preparations. 5. Finally, either protease P3 (0, 0.1 and 1.0 g/kg SBM dry matter) or alpha-galactosidase (0, 0.025 and 0.25 g/kg SBM dry matter) were mixed with SBM alone or in all possible combinations and treated SBMs incorporated into semi-purified diets containing 450 g SBM/kg as the sole source of dietary N and offered to growing broiler chicks for 21 d. Similar patterns of increases in chick growth rate and diet digestibility to those recorded in experiment 3 were obtained when protease P3 and alpha-galactosidase where included in the diets. 6. It is concluded that responses measured by tube-feeding SBM treated with protease P3 and alpha-galactosidase were similar to responses obtained with growing broiler chicks. Further, these responses were obtained by simple addition of enzymes to diets and nutritive value of SBM was improved by both protease and alpha-galactosidase treatment.

Paget's disease of bone--a clinical and genetic study.

An unselected series of 285 patients with Paget's disease of bone has been studied, of whom 54% were male and 46% female. The youngest was aged 25 years at diagnosis and the oldest 95. Of the patients 109 (38-2%) had never suffered serious symptoms. These diagnosed cases certainly represent only a small proportion, perhaps 10-15%, of all those with Paget's disease in the community from which they came. Few of the undiagnosed cases are likely to be suffering from serious symptoms or complications so it is apparent that the majority (probably over 80 or 90%) of those with the pathological state are relatively untroubled by their disease. The most common complication (8-8%) was pathological fracture. The fracture involved the shaft of the femur in 62% occurring in this section of the bone almost seven times more frequently in the patients with Paget's disease than in the general population. Because of the large number of undiagnosed cases in the community, the true incidence of pathological fracture and of sarcoma of bone in all patients with Paget's disease is probably only 1% and 0-1% respectively. Simultaneous estimates of the serum alkaline phosphatase and ESR were made in 128 of the patients. It was shown that the ESR is valueless as a measure of activity or extent of the disease. In many patients the level of the serum alkaline phosphatase changed very little over periods of several years. A history of the disease in one or more close relatives was found in three families, a lower incidence than was expected from previously recorded studies. The ABO blood groups were determined in 215 of the patients; 50% were of group A compared with 46% in a control group. The difference in distribution of blood groups in the two series of subjects is small and well within chance limits. The secretor status of 138 patients was investigated; 77% were secretors. This is similar to the proportion in control series. There is evidence to suggest that the degree of severity of Paget's disease does not vary, once it has developed in any particular individual, and that the more severe and extensive forms may have a stronger genetic basis.