A critical role for the short intracellular C terminus in receptor activity-modifying protein function

Receptor activity-modifying proteins (RAMPs) interact with and modify the behavior of the calcitonin receptor (CTR) and calcitonin receptor-like receptor (CLR). We have examined the contribution of the short intracellular C terminus, using constructs that delete the last eight amino acids of each RAMP. C-Terminal deletion of individual RAMPs had little effect on the signaling profile induced when complexed with CLR in COS-7 or human embryonic kidney (HEK)293 cells. Likewise, confocal microscopy revealed each of the mutant RAMPs translocated hemagglutinin-tagged CLR to the cell surface. In contrast, a pronounced effect of RAMP C-terminal truncation was seen for RAMP/CTRa complexes, studied in COS-7 cells, with significant attenuation of amylin receptor phenotype induction that was stronger for RAMP1 and -2 than RAMP3. The loss of amylin binding upon C-terminal deletion could be partially recovered with overexpression of Gαs, suggesting an impact of the RAMP C terminus on coupling of G proteins to the receptor complex. In HEK293 cells the c-Myc-RAMP1 C-terminal deletion mutant showed high receptor-independent cell surface expression; however, this construct showed low cell surface expression when expressed alone in COS-7 cells, indicating interaction of RAMPs with other cellular components via the C terminus. This mutant also had reduced cell surface expression when coexpressed with CTR. Thus, this study reveals important functionality of the RAMP C-terminal domain and identifies key differences in the role of the RAMP C terminus for CTR versus CLR-based receptors.

The Little Con takes on Deakin Uni

An intimate format of solos and duets, aiming to spotlight the emergence of Deakin University's dance students.

Childhood sexual abuse and adolescent eating disorder : findings from the Victorian Adolescent Health Cohort study

Objective: To examine the relationship between childhood sexual abuse (CSA) before the age of 16 years and later onset of bulimia and anorexia nervosa symptoms in females.

Design: A longitudinal cohort study of adolescents observed from August 1992 to March 2003. The cohort was defined in a 2-stage cluster sample using 44 Australian schools in Victoria.

Setting: Population based.

Participants: A total of 1936 persons participated at least once and survived to the age of 24 years, including 999 females. The mean (SD) age of females at the start of follow- up was 14.91 (0.39) years; and at completion, 24.03 (0.55) years.

Main Exposure: Self-reported CSA before the age of 16 years was ascertained retrospectively at the age of 24 years.

Outcome Measures: Incident Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition)–defined partial syndromes of anorexia and bulimia nervosa were identified between waves 4 (mean age, 16.3 years) and 6 (mean age, 17.4 years) using the Branched Eating Disorder Test.

Results: The incidence of bulimic syndrome during adolescence was 2.5 (95% confidence interval, 0.80-8.0) times higher among those who reported 1 episode of CSA and 4.9 (95% confidence interval, 1.9-12.7) times higher among those who reported 2 or more episodes of CSA, compared with females reporting no episodes, adjusted for age and background factors. The association persisted after adjusting for possible confounders or mediators measured 6 months earlier, including psychiatric morbidity and dieting behavior. There was little evidence of an association between CSA and partial syndromes of incident anorexia nervosa.

Conclusion: Childhood sexual abuse seems to be a risk factor for the development of bulimic syndromes, not necessarily mediated by psychiatric morbidity or severe dieting.

Early age alcohol use and later alcohol problems in adolescents : individual and peer mediators in a bi-national study

This paper examines whether there is cross-national similarity in the longitudinal relationship between early age alcohol use and adolescent alcohol problems. Potential mechanisms underlying this relationship also are examined, testing adolescent alcohol use, low self-regulation, and peer deviance as possible mediators. Students (N = 1,945) participating in the International Youth Development Study, a longitudinal panel survey study, responded to questions on alcohol use and influencing factors, and were followed annually over a 3-year period from 2002 to 2004 (98% retention rate). State-representative, community student samples were recruited in grade 7 in Washington State, United States (US, n = 961, 78% of those eligible; Mage = 13.09, SD = .44) and Victoria, Australia (n = 984, 76% of those eligible; Mage = 12.93, SD = .41). Analyses were conducted using multiple-group structural equation modeling. In both states, early age alcohol use (age 13) had a small but statistically significant association with subsequent alcohol problems (age 15). Overall, there was little evidence for mediation of early alcohol effects. Low self-regulation prospectively predicted peer deviance, alcohol use, and alcohol problems in both states. Peer deviance was more positively related to alcohol use and low self-regulation among students in Victoria compared to students in Washington State. The small but persistent association of early age alcohol use with alcohol problems across both samples is consistent with efforts to delay alcohol initiation to help prevent problematic alcohol use. Self-regulation was an important influence, supporting the need to further investigate the developmental contribution of neurobehavioral disinhibition.

Little Ravens 'Corvus mellori' hunt, kill and eat individuals of two species of shorebird

The Little Raven Corvus mellori is an omnivore that occasionally eats small birds. Most birds taken are thought to be eaten as carrion, though several records exist of ravens hunting and killing Budgerigars Melopsittacus undulates and a Spotted Turtle-Dove Streptopelia chinensis (Higgins et al. 2006). Both cases of bird depredation record Little Ravens attacking from above and stabbing prey to death with their beaks. Here, we report a pair of Little Ravens hunting, killing and eating a lone Sharp-tailed Sandpiper Calidris acuminita at Cheetham Wetlands, near Melbourne, Victoria (37° 53' 56"S, 144° 47' 33"E; 420 ha; see Antos et al. 2007 for a description). We also report an event which strongly implies they hunted and ate an adult Red-capped Plover Charadrius ruficapillus, and observations of hunting and eating eggs and chicks.

The foraging range of Little Penguins (Eudyptula minor) during winter

Although the movements of seabirds at sea during various stages of breeding in spring and summer have been the focus of many studies in recent years, there is still little known about the non-breeding period for most species. Satellite telemetry was used to determine the at-sea movements and foraging range of 47 Little Penguins (Eudyptula minor) from Phillip Island, south-eastern Australia, during the winter non-breeding period. Individuals conducting single-day trips (72% of individuals) typically foraged 8–14 km from the colony, whereas individuals conducting longer trips (28%; 2–49 days) foraged either within Port Phillip Bay or in the coastal waters of western Bass Strait at maximum distances of 62–147 km from the colony. Although there was no difference between sexes in duration of foraging trips, the overall foraging range of males (841 km2) was substantially smaller than that of females (1983 km2) across all months, and showed an overlap of only 34%. Our results show that the foraging range of Little Penguins in the non-breeding period is greater than that observed during the summer breeding period, which suggest a reduction in local food abundance in winter and highlights the importance of foraging areas distant to the colony during a time of increased energetic costs and higher mortality.

Stage of perinatal development regulates skeletal muscle mitochondrial biogenesis and myogenic regulatory factor genes with little impact of growth restriction or cross-fostering

Foetal growth restriction impairs skeletal muscle development and adult muscle mitochondrial biogenesis. We hypothesized that key genes involved in muscle development and mitochondrial biogenesis would be altered following uteroplacental insufficiency in rat pups, and improving postnatal nutrition by cross-fostering would ameliorate these deficits. Bilateral uterine vessel ligation (Restricted) or sham (Control) surgery was performed on day 18 of gestation. Males and females were investigated at day 20 of gestation (E20), 1 (PN1), 7 (PN7) and 35 (PN35) days postnatally. A separate cohort of Control and Restricted pups were cross-fostered onto a different Control or Restricted mother and examined at PN7. In both sexes, peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1α (PGC-1α), cytochrome c oxidase subunits 3 and 4 (COX III and IV) and myogenic regulatory factor 4 expression increased from late gestation to postnatal life, whereas mitochondrial transcription factor A, myogenic differentiation 1 (MyoD), myogenin and insulin-like growth factor I (IGF-I) decreased. Foetal growth restriction increased MyoD mRNA in females at PN7, whereas in males IGF-I mRNA was higher at E20 and PN1. Cross-fostering Restricted pups onto a Control mother significantly increased COX III mRNA in males and COX IV mRNA in both sexes above controls with little effect on other genes. Developmental age appears to be a major factor regulating skeletal muscle mitochondrial and developmental genes, with growth restriction and cross-fostering having only subtle effects. It therefore appears that reductions in adult mitochondrial biogenesis markers likely develop after weaning.

Brains and bravery: little evidence of a relationship between brain size and flightiness in shorebirds

The ability of birds to perceive, assess and appropriately respond to the presence of relatively novel threats is important to their survival. We hypothesized that the cognitive capacity of birds will influence their ability for accurate response to novelty. We used brain volume as a surrogate for cognitive capacity and postulated that larger brained birds would moderate their responses when presented with a benign, frequently occurring stimulus, such as a person, because they would habituate more readily. We conducted phylogenetic generalized least square regression to investigate the relationship between brain volume and flight initiation distance (FID; the distance to which a bird can be approached before initiating escape behaviour), while controlling for confounding factors including body size (body mass and wing length) and migration status. We compared seven different models using combinations of these parameters using Akaike's information criterion to determine the best approximating model(s) explaining FID. The two best-supported models included only wing length and only body mass with Akaike weights of 0.396 and 0.311 respectively. No model including brain volume had an Akaike weight greater than 0.083 and brain volume was poorly correlated with FID in models after controlling for body mass. Thus, brain volume does not appear to strongly relate to bravery among these shorebirds.

Defending friends : Robert Codrington, George Sarawia and Edward Wogale

Friendship between nineteenth century missionary anthropologists and their converted cultural mentors was central to the gathering of cultural and linguistic information. This chapter traces the friendship between Anglican missionary/anthropologist, Robert Codrington, and brothers George Sarawia - first Melanesian priest - and Edward Wogale - deacon. Codrington's theological perspective on Melanesians and his close friendships with the pupils of the Melanesian Mission School at Norfolk Island allowed him to resist the increasing racialism of Atlantic science in the late nineteenth century and to challenge the evolutionist anthropology of the 1870s and 1880s. The chapter is based, in part, on a cache of letters from Wogale and Sarawia to Codrington written in Mota, the lingua franca of the Anglican Mission.

Little evidence that condition, stress indicators, sex ratio, or homozygosity are related to landscape or habitat attributes in declining woodland birds

Habitat loss, fragmentation and degradation are drivers of major declines in biodiversity and species extinctions. The actual causes of species population declines following habitat change are more difficult to discern and there is typically high covariation among the measures used to infer the causes of decline. The causes of decline may act directly on individual fitness and survival, or through disruption of population processes. We examined the relationships among configuration, extent and status of native vegetation and three commonly used indicators of individual body condition and chronic stress (haemoglobin level, haematocrit, residual body mass condition index) in 13 species of woodland-dependent birds in south-eastern Australia. We also examined two measures of changes to population processes (sex ratio and individual homozygosity) in ten species and alleic richness in five species. We found little support for relationships between site or landscape characteristics and individual or population response variables, notwithstanding that our simulations showed we had sufficient power to detect relatively small effects. We discuss possible causes of the absence of detectable habitat effects in this system and the implications for the usefulness of individual body condition and easily measured haematological indices as indicators of the response of avian populations to habitat change. © 2012 The Authors.