Defining the interaction of HIV-1 with the mucosal barriers of the female reproductive tract

Worldwide, HIV-1 infects millions of people annually, the majority of whom are women. To establish infection in the female reproductive tract (FRT), HIV-1 in male ejaculate must overcome numerous innate and adaptive immune factors, traverse the genital epithelium, and establish infection in underlying CD4(+) target cells. How the virus achieves this remains poorly defined. By utilizing a new technique, we define how HIV-1 interacts with different tissues of the FRT using human cervical explants and in vivo exposure in the rhesus macaque vaginal transmission model. Despite previous claims of the squamous epithelium being an efficient barrier to virus entry, we reveal that HIV-1 can penetrate both intact columnar and squamous epithelial barriers to depths where the virus can encounter potential target cells. In the squamous epithelium, we identify virus entry occurring through diffusive percolation, penetrating areas where cell junctions are absent. In the columnar epithelium, we illustrate that virus does not transverse barriers as well as previously thought due to mucus impediment. We also show a statistically significant correlation between the viral load of inocula and the ability of HIV-1 to pervade the squamous barrier. Overall, our results suggest a diffusive percolation mechanism for the initial events of HIV-1 entry. With these data, we also mathematically extrapolate the number of HIV-1 particles that penetrate the mucosa per coital act, providing a biological description of the mechanism for HIV-1 transmission during the acute and chronic stages of infection.

Blocking HIV-1 transmission in the female reproductive tract: from microbicide development to exploring local antiviral responses

The majority of new HIV-1 infections are transmitted sexually by penetrating the mucosal barrier to infect target cells. The development of microbicides to restrain heterosexual HIV-1 transmission in the past two decades has proven to be a challenging endeavor. Therefore, better understanding of the tissue environment in the female reproductive tract may assist in the development of the next generation of microbicides to prevent HIV-1 transmission. In this review, we highlight the important factors involved in the heterosexual transmission of HIV-1, provide an update on microbicides' clinical trials, and discuss how different delivery platforms and local immunity may empower the development of next generation of microbicide to block HIV-1 transmission in the female reproductive tract.

Microscopic modifications of the female reproductive tissues of Mustelus antarcticus

The ovarian follicles and oviducal glands have structural organisations similar to other chondrichthyans. Sperm are stored in the oviducal gland of all maturing and mature animals throughout the year and throughout pregnancy. Microscopic features of the uterine epithelium suggest nutrients are supplied to developing embryos without placenta formation.

Mating effort and female receptivity : how do male guppies decide when to invest in sex?

Males vary in the degree to which they invest in mating. Several factors can explain this variation, including differences in males’ individual condition and the fact that males allocate their energy depending on the context they face in each mating attempt. Particularly, female quality affects male reproductive success. Here, we studied whether male guppies (Poecilia reticulata) strategically allocated more mating effort, in terms of mating behaviour and male–male competition, when they were matched with a receptive (R) female than a non-receptive one. In accordance with our prediction, we found that males increased their mating behaviour when they were with a receptive female. Even though male guppies can inseminate non-receptive females, we only found high levels of courtship between males that were with a receptive female rather than a non-receptive one. Although there was little affect of female receptivity on male–male competition, we found that males chased and interrupted courtships more with receptive females than with non-receptive females regardless of odour. Finally, we also studied whether the sexual pheromone produced by receptive female guppies is a cue that males use in order to increase their mating effort. We found that males were more attracted to a female when they perceived the sexual pheromone, but only increased their mating and aggressive behaviours when females showed receptive behaviour. This strategic increase in mating effort could result in higher male reproductive success because mating attempts towards receptive females are likely to be less costly and males could have a greater probability of fertilisation.

Biennial reproductive cycle in an extensive matrotrophic viviparous batoid : the sandyback stingaree Urolophus bucculentus from south-eastern Australia

Urolophus bucculentus, the largest urolophid species found in southern Australia, exhibits a biennial reproductive cycle. Ovulation occurs during October to January followed by a 15–19 month period of gestation followed by parturition during April to May and a short rest period while the ovarian follicles continue to develop for subsequent ovulation. Male breeding condition peaks during April to June to coincide with the period of parturition. Urolophus bucculentus has the highest matrotrophic contribution reported for any urolophid species, with a mean wet mass gain from egg in utero (4 g) to full-term embryo in utero (250 g) of c. 6250% (maximum c. 7200%), and perhaps explains the biennial female reproductive cycle where 50% of females contribute to each year's recruitment. Litter size (one to five) increases with total length (L_T). Females reach a longer maximum L_T (L_Tmax) than do males (885 v. 660 mm). The L_T at maturity for males and females at 50% mature (L_T50) is c. 414 mm (63% of L_Tmax) for males and c. 502 mm (57% of L_Tmax) for females, length at maternity indicates that recruitment production occurs later in life at c. 632 mm L_T (71% of L_Tmax).

The value of eutherian-marsupial comparisons for understanding the function of glucocorticoids in female mammal reproduction.

This article is part of a Special Issue "SBN 2014". Chronic stress is known to inhibit female reproductive function. Consequently, it is often assumed that glucocorticoid (GC) concentrations should be negatively correlated with reproductive success because of the role they play in stress physiology. In contrast, a growing body of evidence indicates that GCs play an active role in promoting reproductive function. It is precisely because GCs are so integral to the entire process that disruptions to adrenal activity have negative consequences for reproduction. The goal of this paper is to draw attention to the increasing evidence showing that increases in adrenal activity are important for healthy female reproduction. Furthermore, we outline several hypotheses about the functional role(s) that GCs may play in mediating reproduction and argue that comparative studies between eutherian and marsupial mammals, which exhibit some pronounced differences in reproductive physiology, may be particularly useful for testing different hypotheses about the functional role of GCs in reproduction. Much of our current thinking about GCs and reproduction comes from research involving stress-induced levels of GCs and has led to broad assumptions about the effects of GCs on reproduction. Unfortunately, this has left a gaping hole in our knowledge about basal GC levels and how they may influence reproductive function, thereby preventing a broader understanding of adrenal physiology and obscuring potential solutions for reproductive dysfunction.

How to address the ethics of reproductive travel to developing countries: a comparison of national self-sufficiency and regulated market approaches

One of the areas of concern raised by cross-border reproductive travelregards the treatment of women who are solicited to provide their ova orsurrogacy services to foreign consumers. This is particularly troublesome inthe context of developing countries where endemic poverty and low standardsfor both medical care and informed consent may place these womenat risk of exploitation and harm. We explore two contrasting proposals forpolicy development regarding the industry, both of which seek to promoteethical outcomes and social justice: While one proposal advocates efforts tominimize cross-border demand for female reproductive resources throughthe pursuit of national self-sufficiency, the other defends cross-border tradeas a means for meeting the needs of vulnerable groups. Despite theconflicting objectives of the proposed strategies, the paper identifiescommon values and points of agreement between the two, including theimportance of regulations to safeguard those providing ova or surrogacyservices.

Changing bodies, changing discourses : women's experiences of early menopause

Early menopause has been constructed by discourses of biological determinism as an untimely, but natural, failure of the female body. Medical discourses in particular have interpreted early menopause as a congenital irregularity and a rare anomaly of menopause at midlife. In this thesis I challenge the notion that early menopause is an innate imperfection related only to women’s age. I propose that early menopause is dependent upon the cultural interpretations of individual women and is constituted through the mercurial and multiple discourses of women who have this embodied experience. Moreover, I reveal that early menopause is a contemporary condition and that its location in history is inextricably bound to discourses of risk, naturalism and the self. Further I make the assumption that having an early menopause both affects and is an effect of women’s fertility, sexuality and subjectivity. I have drawn upon a broad range of sources to provide a sociological analysis of early menopause. Literature on early menopause is dominated by positivist discourses, yet many alternate discourses negotiate these influential constructions. I suggest here that the perception of early menopause as a natural fault is merely a construction by medical discourses and does not incorporate the dynamic discourses of early-menopausal women. Moreover, the restriction of early menopause to a genetic female failure excludes the majority of women who have an early menopause through iatrogenisis. This omission occurs through the failure of positivist discourses to accommodate diversity in discourses. Recent sociological and feminist studies have vindicated menopausal women. They have reconstructed menopause through notions of embodiment and have removed the veil of negativity used by the medical sciences to contain menopausal women (Komesaroff, Rothfield and Daly 1997). The visibility of menopausal women, however, remains connected to age. Menopause has been created as a predictable consequence of aging and as such has come to be synonymous with middle age. Nowadays, even men are said to experience menopause at midlife (Carruthers 1996). But early menopause is constituted within the discourses of women who have this experience. Medico-scientific discourses, based upon theories of genetic inevitability, disregard this perspective. Consequently early menopause is subsumed by naturalistic discourses that relate menopause to midlife. Such restraint reflects the unease created by menopause that does not coincide with prescribed life stages. Women's experiences of their changing bodies are largely unheard. Thus, women who have an early menopause are faced with a chasm of ‘cultural non-recognition’ (Fraser 1997). Conjointly with this discursive repression early-menopausal women face social imbalances that are transacted as both cause and consequence of early menopause. In particular the contemporary creation of early menopause is bound to the social and historical location of women as a group. Women are exploited by the institution of medicine, ‘exposure to environmental toxicity’ (Fraser 1997: 11) and commercialization as causes of early menopause. Yet the corporeal effects of practices of risk avoidance (Beck 1993), social practices (Shilling 1993) and Western consumerism (Lupton 1994) fail to be recognized. I address these problematics through a poststructural and feminist critique that assumes moments of commonality among women, while at the same time recognizes shifting and multiple differences (Nicholson 1999). I suggest here that early menopause falls into cultural misrecognition in Fraser's (1997) terms and argue that it is united concurrently with the gender injustice of androcentrism (Fraser 1997: 21). Fraser (1997: 16) suggests that it is only by relating these dual problematics that we are able to make sense of current dilemmas. Thus I have critiqued early menopause through a connection between individual embodied experiences of early menopause and early menopause as a modern phenomenon that is specific to women. I have attempted to unravel these arguments that simultaneously call to ‘... abolish gender differentiation and to valorize gender specificity’ (Fraser 1997: 21) while at the same time acknowledging their interconnectedness. An approach of merely combining women’s discourses with overarching social issues would be inadequate as not only do these problematics intersect but they also can be opposed. As Fraser (1997: 25) notes with her theory, redressing one aspect of cultural or social analysis can further imbalance another. For instance making visible the diversity and uniqueness of individual experiences of early menopause could detract from acknowledging the contemporary construction of early menopause through social inequality. Crucial to this understanding is a destabilizing of the binary construction of differences between the sexes that makes way for a reconstruction of early menopause through ‘sexual slippage’ (Matus 1995). In this thesis I look for a subtlety between the particular and the collective that views early menopause as concurrently a singular and changeable experience as well as imbedded in social practice. I suggest that these concepts are entwined as interactive effects of early menopause. Thus I have analyzed the bivalent problematics of the embodiment and social location of early menopause as imbricated, dynamic and unending discourses. From this perspective I reviewed the literature that was available on early menopause. In Chapter One I look to descriptions of early menopause and note that it has disappeared into a conglomeration of disparate, mostly medical, discourses that are contradictory. Nevertheless medical discourses offer ‘conclusive’ definitions of early menopause that are based on naturalistic views of the body (Shilling 1994). The determinants used are inconsistent and do not include women's discourses of early menopause. Thus, dominant medical discourses obscure women’s embodied experiences of early menopause and ignore the contemporary causes of early menopause. In Chapter Two I examine the causes of early menopause as a way of explaining the disparity between medical discourses and my anecdotal observations of early menopause as a fairly common contemporary occurrence. The relatively recent escalation in gynaecological surgery, especially hysterectomy, appears to account almost single-handedly for early menopause as a current phenomenon. Moreover, the extraordinary number of women who have their uterus removed at hysterectomy can be interpreted as a modern implementation of ancient anxieties. Women's sexuality has been constructed throughout history as problematic and this unease has been translated through women's bodies as dangerous and in need of control (Greer 1992). Thus social concerns which have evolved historically have emerged through the representation of a woman's uterus as an unseen, dark and mysterious risk (Beck 1993). Medical discourses define this risk and are able to negate the so-called dangers of women's sexuality through the surgical removal of their organs. Widespread negotiation of medical discourses is apparent, as hysterectomy in the modern Western world is the most common of all surgical operations (Hufnagel 1989). It is overwhelmingly the most common cause of early menopause as well. I examine also the historical condemnation of infertile women and how this anxiety has been transposed to the modern world through the commercialization of reproduction. Transactions of this social unease can cause early menopause. For instance the medical technology of in-vitro fertilization (I.V.F.) has been offered as a panacea for the infertility of early menopause but, paradoxically, can cause early menopause as well. Conception through technology has been normalized as a viable option for women who are unable to conceive and understandings of I.V.F. have moved into everyday discourse. Medical discourses have constructed fertility as a saleable item and infertile women expect that they can purchase this merchandise. Human eggs have become lucrative commodities that now are available in the market place. Egg ‘donation’ for I.V.F. programs can hasten the attrition rate of eggs and can cause early menopause in some pre-menopausal women (Rowland 1992: 24). Even the recycling of a woman’s uterus supposedly has become a possibility through the transferring of this ‘used’ organ at hysterectomy to a recipient woman who can use the other woman’s uterus as a ‘gestational garage’ (Rogers 1998). In this way women have been disembodied as mechanical systems with inter-changeable body parts and the potentially detrimental consequences of these commercial transactions are ignored. In addition I show how early menopause can be caused by the connection between the self and the social structure. Women's subjectivity is constituted through the cultural discourses available to them and these discourses affect social behaviour (Lupton 1995). For instance smoking and dieting have been identified as causes of early menopause. These activities have been related to the creation of women’s bodies as hetero-sexually desirable and are endemic to young women (Evans-Young 1995). This suggests that cultural causes of early menopause are transactions of sexual politics. Yet there is a paucity of literature that acknowledges the relationship between women’s subjectivity and early menopause. Thus the second chapter exposes a link between sexual politics and causes of early menopause through women's relationships with risk, naturalism and the self. In Chapter Three I deconstruct early menopause through theoretical considerations. I rely on an overarching poststructuralism that embraces the concept of fragmented plural discourses and the subjectivity of menopausal women as a continuous process (Komesaroff 1997: 61). I have woven these variables through broad feminist critiques (Leonard 1997). Through this eclectic approach I hoped to find some loose alignment between the corporeal, ontological and embodied dimensions of early menopause. The recurring themes of sexuality, fertility and subjectivity emerge through deconstructing discourses of sexual difference as immutable and non-negotiable; exposing ‘premature ovarian failure’ as a discursive construction that censures early-menopausal women; and acknowledging the discourses of individual women as unique, diverse and dynamic. I looked to a method of exposing some of these individual discourses and in Chapter Four I describe a critical research process aimed at understanding early menopause as a lived experience. In the remaining chapters I align these ontological arguments with an analysis of the discourses of women who had experienced or were experiencing an early menopause. This section partly relieves the ‘cultural non-recognition’ of the discourses of early-menopausal women. I recorded the narratives of fifty early-menopausal women through in-depth interviews and used this empirical data to direct the study. This data provides the opportunity to understand early menopause as an assortment of embodied experiences. For instance women’s experiences of age at commencement of menopause spanned over three and half decades. They did not reflect the age specifications prescribed by medical discourses. Rather women interpreted their experiences within their own discourses and determined their menopause as early based upon the expectations of their cultural context. Many of the women experienced changes attributed to menopause at midlife. It was not these changes that were significant to early-menopausal women it was how each woman translated these changes that provided meanings of early menopause. In Chapter Five I introduce the women through a table that connects the varying experiences of each woman. This profile shows that, in the main, the women’s experiences of early menopause were unexpected. I suggest that this is due to the disparity between early-menopausal women’s experiences and the current age and social norms of menopause. By bracketing the women into cohorts patterns emerged displaying differences between women who had menopause in their teens, twenties, thirties and forties. Adolescent women had intense feelings of abnormality and despair. Women who were in their twenties were less devastated by menopause than the younger women but described their sexuality and self-identity as changing. And although some women in their thirties were shocked or dismayed to have an early menopause others were ambivalent or happy. These women also described their sexuality and self-identity through changing discourses. A number of the women who were in their forties said that they were ‘too young for the menopause’ but were far less despondent than the younger women. It seemed that the greater the distance between age norms and social norms the more negatively women responded. Age norms that determine the social norms of women's lives through a ‘biological clock’ are constructed to reflect social values. But age is a social construction that changes over time. Thus it would appear that women’s changing bodies and changing discourses of early menopause are in the process of recreating age and social norms around menopause. In Chapter Six I draw upon women’s narratives that describe a connection between early menopause and sexuality. Yet the respondents were not unified in their constructions of sexuality. For instance a number of the women rejected the containment of their sexuality as absolute and defined in terms of bi-lateral hetero-sexual opposition. The discourses of these women constructed their sexuality as continuously flexible. Some early-menopausal women described this sexual mobility as an equivocal relationship between their sexuality, reproductive capacity and female organs. Other women articulated their sexuality as vacillating, ambiguous and unrepresentative of the so-called ‘true woman’. Several felt that they were not meant to have female reproductive organs at all. Nearly one third of the women had had their uterus removed at hysterectomy and the reproductive organs of two women were rudimentary. Women’s narratives showed that the social value of fertility influences constructions of early menopause. In Chapter Seven I record the contrast between the poignant responses of women who wished to have a baby of their own and other women who resisted discourses that entwine reproductivity with being a woman. For instance some women negotiated fertility through economic discourses of consumerism with the expectation that they could purchase conception as a commodity. Other women welcomed their early menopause as freedom from contraceptive concerns and others had no interest in reproduction at all. Thus discord arose through discourses that problematize early-menopausal women as non-reproductive and discourses that value variability. In addition many of the women’s accounts constructed their subjectivity as mobile, challenging the notion that discourses of the self are immutable. Chapter Eight presents narratives which suggest that the subjectivity of many women was altered continuously by early menopause. Yet some of the women rejected the construction of their subjectivity as unfluctuating. These contradictions reflect the uncertainties of the contemporary world. Nevertheless most respondents found that the tethering of menopause to constructions of midlife was incongruous with their own experiences. Many women refused to accept the label of social redundancy attached to middle-aged women. They moved their subjectivity beyond the reproductive body to a shifting and tractable identity of the self. This thesis demonstrates that the medical construction of early menopause as a rare and natural female flaw varies from women's experiences which suggest that early menopause is common and discursively constructed. This disparity has occurred through the privilege placed upon the construction of bodies as immutable and sexually static. This privileging has obscured the multi-dimensional causes of early menopause and given preference to a mono-causal theory. By exposing the variety of causes of early menopause the medical construction of women through a universal and unalterable body of reproduction is challenged. Moreover, women's discourses of early menopause demonstrate that the medical reduction of early menopause to a spontaneous bio-chemical malfunction has ignored the volatility of women’s embodied experiences. Women experience early menopause variously and through mercurial discourses. I suggest here that women's discourses of their experiences of early menopause reflect recurring and restructuring philosophical quandaries of fertility, sexuality and subjectivity. While there can be no representative claims made from this thesis it contributes to an understanding of the embodied experiences of early menopause. It provides an understanding of the creation of early menopause through social practices and goes part way to redressing the problematics of what Fraser terms ‘cultural non-recognition’. But, more importantly, it acknowledges early menopause as a variety of experiences where women interpret their changing bodies through changing discourses.

Molting and reproduction in portunus pelagicus

This investigation describes ovarian maturation stages in the female reproductive system, evidence for histones in sperm nuclei and novel morphological changes that occur during spermiogenesis in the male blue swimming crab, portunus pelagicus. It also identifies dual functionality of the molt inhibiting hromone on molting and vitellogenesis through RNA inteference.

Do male guppies distinguish virgin females from recently mated ones?

In some mating systems males should benefit from mating with virgin females because of their higher reproductive value. We determined experimentally whether and how males distinguish between virgin and recently mated females in the guppy, Poecilia reticulata, a promiscuous livebearer. In a free-swimming experiment, males showed flexible mating behaviour by adjusting their tactics according to the mating status of the female they encountered, virgin or mated. Males followed, nipped and copulated with virgins more than with mated females, but they performed more sneaky copulations with mated females, possibly because the latter were more reluctant to mate than virgin females. When, in another set of experiments, males received only the visual cues of both virgins and mated females they showed no preference for either, but when they were exposed only to the female olfactory cues, they associated considerably more with the smell of virgin females. These results suggest that male guppies assess female behavioural and olfactory cues to determine female virginity and then use different mating tactics depending on the female's status. It is possible that the changes in male mating behaviour increase male reproductive success.

Biological vulnerability of two exploited sharks of the genus Deania (Centrophoridae)

Life-history parameters of Deania calcea and Deania quadrispinosa suggested that their productivity was very low. Maturity (L_T50) occurs at c. 80% of maximum observed total lengths (L_T) for both species and sexes. A large proportion of mature females were neither pre-ovulatory nor pregnant, and the reproductive cycle included a distinct resting phase after pregnancy. For D. calcea, mean ovarian fecundity was 12 and maximum observed litter size was 10 (average of six); D. quadrispinosa averaged 17 pups per litter. Birth L_T was 28-33 cm for D. calcea and 23-25 cm for D. quadrispinosa. The male and female reproductive cycles were aseasonal, and consequently, the length of the reproductive cycle could not be determined. Preliminary ageing data from dorsal-spine growth bands suggested that female D. calcea lived to 31-36 years and males to 24-32 years. The L_T-at-age data using external bands on the spines showed maturity occurring at 15·5 years (males) and 21·5 years (females), whereas banding on the internal dentine indicated maturity at 10·5 and 17·5 years for males and females. Thus, a female lifetime of 31-36 years allowed for a maximum of 7 litters if a 2 year cycle is assumed or only five litters with a 3 year cycle, resulting in a lifetime fecundity of only 42 pups (2 year cycle) or even lower (3 year cycle).

Acceleration data reveal the energy management strategy of a marine ectotherm during reproduction

1. Maintaining a high and stable body temperature is often critical for female ectotherms during reproduction. Yet this strategy may be energetically costly, and therefore challenging, during this period of already high-energy demand. 2. Here, the 6-week deployment of tri-axial accelerometers (n = 6) on a marine ectotherm, the loggerhead turtle (Caretta caretta), reproducing at the northern limit of the species’ breeding range (i.e. in a thermally dynamic environment) revealed the behavioural mechanisms underlying its energy management strategy during the breeding season. 3. The estimated activity levels of female loggerheads using overall dynamic body acceleration (ODBA) were high during the breeding season, suggesting that marine turtles may not be able to remain inactive for long periods in the same manner as terrestrial ectotherms, because of the thermally dynamic nature of their environment. 4. However, activity levels were not constant throughout the season, being impacted by both ambient water temperature and female reproductive status. In cold water at the beginning of the nesting season, high levels of activity suggested that females behaviourally thermoregulated by seeking out warm water patches along the shoreline. Interactions with male turtles (courtship and/or avoidance) may also explain this high level of activity. As sea temperatures warmed up and the amount of energy devoted to reproduction probably increased, the turtles spent more time resting during long sequential flat-bottomed dives, and reduced any unnecessary locomotory activity. 5. Turtles may therefore adjust their activity patterns in response to seasonal variations in abiotic (i.e. ambient temperature) and biotic (i.e. reproductive status) factors. This may help minimize activity-linked metabolic rate and maximize reproductive output over a season while breeding in thermally dynamic environments. 6. A mechanistic model gave support to these empirical results. The model revealed that actively maintaining high and stable body temperature is of clear benefit to female turtles at temperate breeding sites. While energetically costly, such active thermoregulatory behaviour may speed up egg maturation, allowing turtles to initiate nesting earlier in the season, and hence maximize reproductive output.

Study protocol: the childhood to adolescence transition study (CATS)

Background
Puberty is a multifaceted developmental process that begins in late-childhood with a cascade of endocrine changes that ultimately lead to sexual maturation and reproductive capability. The transition through puberty is marked by an increased risk for the onset of a range of health problems, particularly those related to the control of behaviour and emotion. Early onset puberty is associated with a greater risk of cancers of the reproductive tract and cardiovascular disease. Previous studies have had methodological limitations and have tended to view puberty as a unitary process, with little distinction between adrenarche, gonadarche and linear growth. The Childhood to Adolescence Transition Study (CATS) aims to prospectively examine associations between the timing and stage of the different hormonally-mediated changes, as well as the onset and course of common health and behavioural problems that emerge in the transition from childhood to adolescence. The initial focus of CATS is on adrenarche, the first hormonal process in the pubertal cascade, which begins for most children at around 8 years of age.

Methods/Design
CATS is a longitudinal population-based cohort study. All Grade 3 students (8–9 years of age) from a stratified cluster sample of schools in Melbourne, Australia were invited to take part. In total, 1239 students and a parent/guardian were recruited to participate in the study. Measures are repeated annually and comprise student, parent and teacher questionnaires, and student anthropometric measurements. A saliva sample was collected from students at baseline and will be repeated at later waves, with the primary purpose of measuring hormonal indices of adrenarche and gonadarche.

Discussion
CATS is uniquely placed to capture biological and phenotypic indices of the pubertal process from its earliest manifestations, together with anthropometric measures and assessment of child health and development. The cohort will provide rich detail of the development, lifestyle, external circumstances and health of children during the transition from childhood through to adolescence. Baseline associations between the hormonal measures and measures of mental health and behaviour will initially be examined cross-sectionally, and then in later waves longitudinally. CATS will make a unique contribution to the understanding of adrenarche and puberty in children’s health and development.