Variation in the food intake of grass carp, Ctenopharyngodon idella (Val.), fed singly or in groups

Each animal may be assumed to possess a unique combination of physiological traits (Bennett, 1987). However, there is little information on thc effects of interindividual variation in fish (Cui and Liu, 1990). Individual differences in competitive ability, aggressiveness and or size can lead to the establishment of dominance hierarchies within groups of fish (Metcalfe, 1989; Metcalfe et al., 1989). The variation in growth rates in groups of fish are rclated to dominance hierarchies and preferential access to food resources by dominant individuals (Jenkins, 1969; Fausch, 1984; Koebele, 1985). Recently, radiography has been used to measure individual consumption rates for groups of salmonids and has demonstrated considerable inter-individual variation in food intake (Jobling et al., 1989; Carter et al., 1992a; McCarthy et al., 1992). Two aims of this study were to use radiography to examine the variation in the food consumption rate of grass carp, Ctenopharyngodon idellu (Val.), held together and to assess whcther variation in growth rates could bc explained by variation in consumption rates. A final aim of this study was to compare the day to day variation in consumption rates of grass carp held in a group to thosc held individually, in terms of the individual meal share, in order to examine the cffect of endogenous influences on appetite

Metabolic rate and rates of protein turnover in food-deprived cuttlefish, Sepia officinalis (Linnaeus 1758)

To determine the metabolic response to food deprivation, cuttlefish (Sepia officinalis) juveniles were either fed, fasted (3 to 5 days food deprivation), or starved (12 days food deprivation). Fasting resulted in a decrease in triglyceride levels in the digestive gland, and after 12 days, these lipid reserves were essentially depleted. Oxygen consumption was decreased to 53% and NH4 excretion to 36% of the fed group following 3-5 days of food deprivation. Oxygen consumption remained low in the starved group, but NH4 excretion returned to the level recorded for fed animals during starvation. The fractional rate of protein synthesis of fasting animals decreased to 25% in both mantle and gill compared with fed animals and remained low in the mantle with the onset of starvation. In gill, however, protein synthesis rate increased to a level that was 45% of the fed group during starvation. In mantle, starvation led to an increase in cathepsin A-, B-, H-, and L-like enzyme activity and a 2.3-fold increase in polyubiquitin mRNA that suggested an increase in ubiquitin-proteasome activity. In gill, there was a transient increase in the polyubiquitin transcript levels in the transition from fed through fasted to the starved state and cathepsin A-, B-, H-, and L-like activity was lower in starved compared with fed animals. The response in gill appears more complex, as they better maintain rates of protein synthesis and show no evidence of enhanced protein breakdown through recognized catabolic processes

Structure and functions of the ventral tube of the clover springtail Sminthurus viridis (Collembola Sminthuridae)

YesSpringtails (Collembola) are unique in Hexapoda for bearing a ventral tube (collophore) on the first abdominal segment. Although numerous studies have been conducted on the functions of the ventral tube, its fine structure has not been thoroughly elucidated to date. In this paper, we observed the jumping behavior of the clover springtail Sminthurus viridis (Linnaeus, 1758) and dissected the ventral tube using light microscopy to elucidate the fine structure and the possible function of the ventral tube. The results show that a pair of eversible vesicles can be extended from the apical opening of the ventral tube. The eversible vesicles are furnished with numerous small papillae, and can be divided into a basal part and a distal part. The eversible vesicles have a central lumen connected to the tiny papillae and leading to the body cavity. The eversible vesicles can reach any part of the body, and may serve as following functions: (a) absorbing moisture; (b) uptaking water; (c) cleaning the body surface; and (d) fastening the body on a smooth surface

Evidence-based Kernels: Fundamental Units of Behavioral Influence

This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior

Associations between a polymorphism in the pleiotropic GCKR and Age-related phenotypes: the HALCyon programme.

Background: The glucokinase regulatory protein encoded by GCKR plays an important role in glucose metabolism and a single nucleotide polymorphism (SNP) rs1260326 (P446L) in the gene has been associated with several age-related biomarkers, including triglycerides, glucose, insulin and apolipoproteins. However, associations between SNPs in the gene and other ageing phenotypes such as cognitive and physical capability have not been reported. Methods: As part of the Healthy Ageing across the Life Course (HALCyon) collaborative research programme, men and women from five UK cohorts aged between 44 and 90+ years were genotyped for rs1260326. Meta-analysis was used to pool within-study genotypic associations between the SNP and several age-related phenotypes, including body mass index (BMI), blood lipid levels, lung function, and cognitive and physical capability. Results: We confirm the associations between the minor allele of the SNP and higher triglycerides and lower glucose levels. We also observed a triglyceride-independent association between the minor allele and lower BMI (pooled beta on zscore = 20.04, p-value = 0.0001, n = 16,251). Furthermore, there was some evidence for gene-environment interactions, including physical activity attenuating the effects on triglycerides. However, no associations were observed with measures of cognitive and physical capability. Conclusion: Findings from middle-aged to older adults confirm associations between rs1260326 GCKR and triglycerides and glucose, suggest possible gene-environment interactions, but do not provide evidence that its relevance extends to cognitive and physical capability

Protein Synthesis

Protein synthesis is fundamental to all living organisms and it has been studied . intensively and at varying levels of complexity but, as Waterlow (1995) points out, a primary motivation for early interest was to help solve important human health problems such as malnutrition in infants. Many excellent recent reviews chart theoretical and practical developments in human and animal (mammalian) protein nutrition (Fuller and Garlick, 1994; Kimball et ai., 1994; Waterlow, 1995, 1999; Millward, 1998; Lobley et al., 1999). The study of protein synthesis in ectotherms, particularly fish, has also received attention (Haschemeyer, 1973; Fauconneau, 1985; Houlihan, 1991; Houlihan et ai., 1993a, 1995a,b). A recent moti3