Parasites affect song complexity and neural development in a songbird

There is now considerable evidence that female choice drives the evolution of song complexity in many songbird species. However, the underlying basis for such choice remains controversial. The developmental stress hypothesis suggests that early developmental conditions can mediate adult song complexity by perturbing investment in the underlying brain nuclei during their initial growth. Here, we show that adult male canaries (Serinus canaria), infected with malaria (Plasmodium relictum) as juveniles, develop simpler songs as adults compared to uninfected individuals, and exhibit reduced development of the high vocal centre (HVC) song nucleus in the brain. Our results show how developmental stress not only affects the expression of a sexually selected male trait, but also the structure of the underlying song control pathway in the brain, providing a direct link between brain and behaviour. This novel experimental evidence tests both proximate and ultimate reasons for the evolution of complex songs and supports the Hamilton–Zuk hypothesis of parasite-mediated sexual selection. Together, these results propose how developmental costs may help to explain the evolution of honest advertising in the complex songs of birds.

The assessment and management of common male sexual difficulties in family practice

Sexual problems are distressing for patients, and their doctors need to feel comfortable giving advice about and treating the more common conditions. Treatment of sexual problems can prevent much anxiety and the development of depression. This article outlines approaches useful in managing the more common male sexual difficulties encountered in family practice.

Control of ovarian development in the yabby (Cherax destructor)

A study under controlled conditions of ovarian development and rematuration in the yabby (Cherax destructot) was undertaken. The purpose of the study was to improve fundamental understanding of the reproductive biology of the species and provide a basis for application to hatchery management in culture. A review was made of the current status of yabby culture in Australia and the present understanding of reproductive biology of decapod Crustacea. The review emphasised factors controlling several aspects of ovarian development, in particular the processes of vitellogenesis. The subsequent study was designed within the context of current hatchery practice and was based on existing knowledge of decapod reproduction, The sexual differentiation of the yabby after hatching was investigated by serial histological sections, and experiments were carried out to investigate the possibility of sex reversal of males. Most of this Investigation was concerned with removing the influence of the androgenic gland in directing male development, with the intent of observing the development of the elementary gonadal tissue into ovary. It was found that in contrast to other crustacean species, the sex of the yabby becomes fixed before the development of external secondary sexual characteristics, and before the androgenic gland can be discerned. Ovarian tissue developed in females at less than 8 weeks after hatching. A preliminary examination was undertaken for feminising parasites in gonadal tissue of a hermaphrodite yabby. Investigation of the ovary after spawning demonstrated that whilst the female was held under constant conditions of temperature and photoperiod, little rematuration occurred. Except for generation of previtellogenic oocytes during the first two days, the gonaciosomatic index remained low for up to 5 months after spawning. If the temperature of the female was reduced to 10°C and maintained constant, the previtellogenic oocytes were partially resorbed over a three week period. Rematuration then commenced, albeit at a low rate because of the reduced temperature, A method for standardising gonadosomatic indices was developed which took into account differences in hepatopancreatic nutrient reserves of individuals and loss of one or more appendages. This part of the study also considered constraints to rematuration and developed a method of accounting for differences in the ability of females to remature after spawning. Experiments were carried out to investigate the effect of crowding and temperature manipulation on initiating ovarian rematuration and to determine the rate of rematuration at 22°C once initiated. The duration of low temperature had no effect on rematuration; an overnight cooling was sufficient to initiate the process, Rematuration to the end of stage 2 vltellogenesis was substantially complete within 10 days. Crowding of females suppressed rematuration, but less than ideal water quality was not found to have any effect. The presence of a male initiated rematuration at a similar rate, but also led to stage 3 vitetlogenesis and spawning. A study was made of the pheromonal influence of the male through water borne factors without success. Rematuration could not be induced in ovigerous females. The literature review indicated that ovarian rematuration was under the control of an ovary stimulating hormone produced by the thoracic nerve ganglia. Attempts were therefore made to stimulate ovarian rematuration by incorporating the thoracic nerve into the diet of females. Attempts were also made to induce the release of ovary stimulating hormone from the thoracic nerve with 5-hydroxytryptamine, and also with octopamine. No effects were found, but a significant difference between the neurophysiology of the yabby and northern hemisphere crayfish was observed, and the implications of this finding are discussed. The study did not produce any conclusive evidence of an ovary stimulating hormone for the yabby. A model of ovarian rematuration which collects the findings of the experimental investigations was developed, and was used to suggest a hatchery broodstock management protocol. This model differs from existing models in that rematuration triggers and nutritional status are considered.

Female sexual dysfunction

This thesis examined the aetiology of female sexual dysfunction (FSD) and a model to represent sexual function. Relationship factors were the main predictor of sexual function for women with FSD. A circular model of sexual response represented women's sexual experience for those with FSD and those who did not have FSD. In order to illustrate the role of family emotional involvement in children's development of psychological disorders the portfolio presents and explores four case studies.

Silence and silenced : implications for the spirituality of survivors of sexual abuse

Survivors of sexual abuse are frequently met with cultures of silence which make it difficult for their experiences to be acknowledged. Furthermore, many have been subjected to threats and intimidation in efforts to ensure that they remain silent about what has happened to them. One response to such experiences is to keep oneself busy and avoid ever being quiet enough to experience a sense of silence within. However, many spiritual traditions promote the embracing of silence as essential for those seeking spiritual development. This paper explores these diverse experiences of silence for survivors of sexual abuse and considers why spiritualities which promote silence can be problematic.

Pathways to female sexual offending : approach or avoidance?

This study forms the second part of a larger investigation into the offence process characteristics of female sexual offenders (FSOs). In the first part - documented in Gannon, Rose, and Ward (Sexual Abuse: A Journal of Research and Treatment, 20, 352-374, 2008) - we described the development of the Descriptive Model of Female Sexual Offending (DMFSO); an offence process model developed using Grounded Theory methodology to describe the sequence of cognitive, affective, behavioural and contextual factors generating female-perpetrated sexual abuse. The second study described here examines the prevalence of specific pathways characterizing the 22 FSOs originally used to develop the DMFSO. Four individuals could not be assigned to a pathway due to lack of information (18% of the overall sample). However, for the remaining 18 participants, three stable pathways to female sexual offending were identified: Explicit Approach offenders (50%, n=9), who intended to offend, and explicitly planned their offence behaviours accordingly; Directed Avoidant offenders (28%, n=5), who did not intend to offend, but did so under the direction and coercion of a male accomplice; and Implicit Disorganized offenders (22%, n=4), who did not intend to offend (i.e. they engaged in minimal planning), but offended impulsively following severe self-regulatory failure. In this paper, we present the core characteristics defining each pathway, their associated demographic features, and discuss potential treatment implications.

The structural properties of sexual fantasies for sexual offenders : a preliminary model

While the phenomenon of sexual fantasy has been researched extensively, little contemporary inquiry has investigated the structural properties of sexual fantasy within the context of sexual offending. In this study, a qualitative analysis was used to develop a descriptive model of the phenomena of sexual fantasy during the offence process. Twenty-four adult males convicted of sexual offences provided detailed retrospective descriptions of their thoughts, emotions and behaviours—before, during and after their offences. A data-driven approach to model development, known as Grounded Theory, was undertaken to analyse the interview transcripts. A model was developed to elucidate the structural properties of sexual fantasy in the process of sexual offending, as well as the physiological and psychological variables associated with it. The Sexual Fantasy Structural Properties Model (SFSPM) comprises eight categories that describe various properties of sexual fantasy across the offence process. These categories are: origin, context, trigger, perceptual modality, clarity, motion, intensity and emotion. The strengths of the SFSPM are discussed and its clinical implications are reviewed. Finally, the limitations of the study are presented and future research directions discussed.

The role of culture in understanding child sexual offending : examining feminist perspectives

Psychological theories on child sexual abuse continue to dominate etiological and rehabilitative approaches to understanding and treating sexually abusive behavior. However, even though psychological researchers are motivated toward development of comprehensive and highly integrated theories, there has been continued neglect of the cultural dimensions of child sexual abuse. Feminist theories of child sexual abuse have been particularly helpful in filling this explanatory gap, as they have persisted in locating sexually abusive behavior within a cultural context. In this paper we review and critique selected feminist theories on child sexual abuse with the aim of establishing their explanatory scope and utility. Overall, we found that feminist perspectives were useful in justifying and establishing social policies aimed at preventing the sexual abuse of children from ever commencing. However, despite this strength, they offer little guidance in the treatment of individual offenders.

Empathy and adolescent sexual offenders : a review of the literature

A significant proportion of sexual offenses has been found to be committed by adolescent offenders. Although there is overlap in the backgrounds of adolescent sexual offenders and juvenile delinquents, in recent times there has been an increased effort to identify and treat adolescent sexual offenders as a distinct population. Adolescent sexual offenders are thought to be empathy deficient, with empathy development a commonly defined treatment goal. There is confusion, however, as to whether such empathy deficits are general in nature, are towards certain groups of people, or are own victim-specific. This article provides a review of the literature concerning empathy and adolescent sexual offenders and, based on this assessment, recommendations are made for future research.

An integrated theory of sexual offending

This paper represents a first attempt to provide an integrated framework to explain the onset, development, and maintenance of sexual offending. According to the Integrated Theory of Sexual Offending (ITSO), sexual abuse occurs as a consequence of a number of interacting causal variables. We examine the factors that affect brain development (evolution, genetic variations and neurobiology) and ecological factors (social and cultural environment, personal circumstances, physical environment) and discuss how they impact upon core neuropsychological functions underpinning human action. The ITSO then explains how clinical symptoms arise from the interaction between these neurological systems and ecological factors. The capacity of the ITSO to incorporate competing theories of sexual offending is considered, and we end the paper by critically evaluating its usefulness in stimulating research and further theory development.

The developmental stress hypothesis: A special case of the evolution of condition-dependent sexual traits

The idea that sexually selected traits might be condition dependent is far from novel (Zahavi 1975); however, the developmental stress hypothesis was proposed as a special case because of a highly plausible mechanism: the development of the neural circuits controlling song output coincides with a period of time during which developing birds are likely to be susceptible to stress. The elegant aspect of the hypothesis is that the mechanism is defined and effects can be readily tested (Nowicki et al. 1998; Buchanan et al. 2003). Compared with more general hypotheses about the evolution of condition-dependent sexual traits (Buchanan 2000), the second particularly interesting aspect of the developmental stress hypothesis is that, in some species, individuals may suffer historical markers of stress. This is because in species with a fixed period for neural growth and song learning, there is no possibility for compensation in later life for stress experienced during early development. Females using such a marker of stress may benefit by obtaining a partner whose other cognitive functions have not been impaired by stress.

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.

Conditionally sexual : men and teenage boys with moderate to profound intellectual disability

This article presents qualitative research data about the sexuality of men and teenage boys with moderate to profound intellectual disability. Research findings pointed to a conditional construct of sexuality based within a biopsychosocial framework. The notion Conditionally Sexual represents the perceived limitations, within a rights-based discourse, of these men and teenage boys’ sexuality. The limitations to person-centred service delivery from a policy vacuum in the area of sexuality and intellectual disability represents a major challenge for paid staff. We suggest that a move toward better understanding how to support such a conditional sexual construct will assist the development of a healthy masculine sexuality for men and boys with intellectual disability.

Development of twenty-three novel microsatellite markers for the seagrass, Zostera muelleri from Australia

Seagrasses are one of the most productive and economically important habitats in the coastal zone, but they are disappearing at an alarming rate, with more than half the world’s seagrass area lost since the 1990s. They now face serious threat from climate change, and there is much current speculation over whether they will survive the coming decades. The future of seagrasses depends on their ability to recover and adapt to environmental change—i.e. their ‘resilience’. Key to this, is understanding the role that genetic diversity plays in the resilience of this highly clonal group of species. To investigate population structure, genetic diversity, mating system (sexual versus asexual reproduction) and patterns of connectivity, we isolated and characterised 23 microsatellite loci using next generation sequencing for the Australian seagrass species, Zostera muelleri (syn. Z. capricorni), which is regarded as a globally significant congeneric species. Loci were tested for levels of variation based on eight individuals sampled from Lake Macquarie, New South Wales, Australia. We detected high to moderate levels of genetic variation across most loci with a mean allelic richness of 3.64 and unbiased expected hetrozygosity of 0.562. We found no evidence for linkage disequilibrium between any loci and only three loci (ZosNSW25, ZosNSW2, and ZosNSW47) showed significant deviations from Hardy–Weinberg expectations. All individuals displayed a unique multi-locus genotype and the combined probability of identity across all loci was low (P _ID = 1.87 × 10⁻¹²) indicating a high level of power in detecting unique genotypes. These 23 markers will provide an important tool for future population genetic assessments in this important keystone species.

The business of sexuality education : changing practice : the need for professional development

This paper reports on data collected from practicing sexuality education teachers following their participation in professional learning intervention in sexuality education. It explores whether the provision of effective professional development and classroom resources enables teachers to effectively address the sensitive issues of sexual diversity, gender and power.