Protecting the health of the athlete is a goal of the International Olympic Committee (IOC). The IOC convened an expert panel to update the 2005 IOC Consensus Statement on the Female Athlete Triad. This Consensus Statement replaces the previous and provides guidelines to guide risk assessment, treatment and return-to-play decisions. The IOC expert working group introduces a broader, more comprehensive term for the condition previously known as ‘Female Athlete Triad’. The term ‘Relative Energy Deficiency in Sport’ (RED-S), points to the complexity involved and the fact that male athletes are also affected. The syndrome of RED-S refers to impaired physiological function including, but not limited to, metabolic rate, menstrual function, bone health, immunity, protein synthesis, cardiovascular health caused by relative energy deficiency. The cause of this syndrome is energy deficiency relative to the balance between dietary energy intake and energy expenditure required for health and activities of daily living, growth and sporting activities. Psychological consequences can either precede RED-S or be the result of RED-S. The clinical phenomenon is not a ‘triad’ of the three entities of energy availability, menstrual function and bone health, but rather a syndrome that affects many aspects of physiological function, health and athletic performance. This Consensus Statement also recommends practical clinical models for the management of affected athletes. The ‘Sport Risk Assessment and Return to Play Model’ categorises the syndrome into three groups and translates these classifications into clinical recommendations.
Sex allocation in animals is predicted to be skewed from a 1:1 ratio if sons and daughters yield different marginal fitness returns per unit maternal investment. We tested this prediction using the gall‐forming aphid Tetraneura sorini , in which lethal fighting is common among females, whereas male–male competition is moderate. Mothers (autumnal winged females) parthenogenetically produce females and males in their abdomen and can control their sizes and numbers. The females and males do not feed after birth. After mating, females produce single eggs, from which only females (foundresses) hatch and fight intensely with one another during the galling process. Larger‐sized foundresses have overwhelming advantages in fighting. If mothers invest more in individual females, they can produce larger foundresses (granddaughters), which yields greater fitness returns. This situation is contrary to the original Trivers–Willard hypothesis. Thus, we predicted that more fecund mothers in this species would invest more in females. The cost of producing one female was found to be 3.0–3.2 times the cost of producing one male. Population sex ratios were male‐biased (54.8%–58.2% male), but population sex allocation was highly female biased (68%–72% females). Larger mothers biased their progeny sex ratios more towards females and produced larger females, thus supporting our prediction. Mothers produced two types of brood: all‐female broods and mixed‐sex broods. Mothers with an all‐female brood produced larger females than those with a mixed‐sex brood, thereby offering their granddaughters (foundresses) an advantage in fighting. Local mate competition has been postulated to explain female‐biased population sex allocation in gall‐forming aphids. However, we concluded that competition among foundresses has led to the evolution of female‐biased sex allocation at the population level and dimorphism in brood sex composition. 如果母亲可以自由决定后代的性别, 她会做怎样的决定？进化生态学中一个著名的理论（特里弗斯‐威拉徳假说）预测：动物中如红鹿, 雄性间存在争夺配偶的争斗时, 营养状态良好的母亲会将后代性别分配比更偏向于雄性。营养状态良好的母亲可以为她的儿子提供更充足的奶水, 所以儿子可以逐渐发育成体型较大且善于斗争的成年雄鹿。因此, 哺养儿子至一个较大的体型意味着母亲可以通过儿子的繁殖优势获得更大的遗传回报。然而这个理论较难去验证且已有的凭证案例不够充足。这里我们用一个雌性间争斗的造瘿蚜虫为例子来验证这个假说。与一般的哺乳动物不同的是, 在这种造瘿蚜虫中：一龄的雌性幼虫会因虫瘿而展开争斗, 且体型较大的雌性在争斗中具有压倒性的优势；儿子和女儿在母亲腹中发育至最终体型；之后参与争斗的雌性仅拥有母亲提供的营养来发育。以上提到的这些条件非常适合验证这个理论. 实验结果表明, 体型较大的母亲会将后代性别分配比更偏向于雌性, 并生产体型较大的女儿。这个结果明确地验证了特里弗斯‐威拉徳假说。然而, 依旧存在一个问题：就是在种群水平上性别分配比是非常偏向雌性的. 这种非常偏向雌性的性别分配比的现象可以通过考虑蚜虫独特的有性无性世代交替的生命周期来解释。一般来说, 在动物种群中,后代雌雄性别分配比为一比一。然而, 在同时存在有性无性世代的动物中, 如果在无性世代中雌性间存在争斗, 理论预测在有性世代时, 性别分配比会更偏向雌性。所以, 这个研究不仅验证了进化生态学中的一个重要理论, 还开启了一个新的假说的可能。 【图片说明】 主图为宗林四脉绵蚜 ( Tetraneura sorini ) 的虫瘿。右上方为玻片封固标本中的有性雌虫与雄虫。右下方为一龄干母幼虫, 其会诱导产生虫瘿并频繁与其他一龄幼虫进行争斗。 A plain language summary is available for this article. Plain Language Summary
According to socioecological theory, ecological pressures acting on females play an important role in shaping social organization, dispersal patterns and the nature of female–female relationships. However, there has been relatively little consideration of how females' relationships with males may influence the nature of females' relationships to other females. Here, we show that female olive baboons form well-differentiated relationships with adult males and these ties influence their relationships with other females. As in other species of savanna baboons, female olive baboons show pronounced preferences for close kin, but related females do not often share the same top-ranked male partners. Shared associations with males bring females into more frequent contact with distant kin and nonkin. The combined effects of bringing distantly related and unrelated females together and separating close kin reduced the extent of nepotistic biases among females in the study groups compared to female yellow baboons, , and chacma baboons, . These data suggest that selective pressures acting on both females and males may influence the nature and function of female–female relationships.
Female pattern hair loss (FPHL) is a common non-scarring alopecia characterized by widening of the midline hair part at the crown (vertex). In 1977, Ludwig developed a scale that graded the degree of visible vertex hair thinning from I (least severe) to III (most severe). However, by the time patients exhibit the full manifestations of 'Ludwig I', they have already lost a significant volume of hair. Although current therapies may realistically halt progression of hair loss, improvements in hair density is often more limited. Identification and grading of FPHL at an earlier stage is desirable to institute appropriate therapy before significant hair loss has occurred and to enable monitoring over time. To generate consensus guidance for the recognition and quantification of FPHL that can be used in the clinic. Nine clinicians from Europe, North America and Australia experienced in the management of FPHL developed this scale by consensus. We propose a three-point severity scale (termed the FPHL Severity Index (FPHL-SI)) that combines validated measures of hair shedding, midline hair density and scalp trichoscopy criteria to produce a total FPHL-SI score (maximum score = 20). The score is designed to grade FPHL severity over time, while being sufficiently sensitive to identify early disease. A score of 0-4 makes FPHL unlikely; a score of 5-9 would indicate early-stage FPHL, with higher scores indicating greater disease severity. As a starting point for further public debate, we employ criteria already used in clinical practice to generate a pragmatic FPHL grading system (FPHL-SI) of sufficient sensitivity to identify and monitor early FPHL changes. This may have to be further optimized after systematic validation in clinical practice.
In a range of taxa, the relatedness between mates influences both pre- and post-mating processes of sexual selection. However, relatively little is known about the genetic loci facilitating such a bias, with the exception of the major histocompatibility complex. Here, we performed tightly controlled replicated in vitro fertilization trials to explore the impact of relatedness on two possible mechanisms of cryptic female choice (CFC) in Chinook salmon (Oncorhynchus tshawytscha). We tested (i) whether relatedness of mates, assessed using 682 single nucleotide polymorphisms (SNPs) on 29 SNP-linkage groups (LGs), biases a male's sperm velocity in ovarian fluid (a parameter previously shown to predict male fertilization success), and (ii) whether relatedness of mates governs fertilization success via other mechanisms, probably via sperm-egg interactions. We found that relatedness on three LGs explained the variation in sperm velocity, and relatedness on two LGs explained fertilization success, which might indicate the presence of genes important in sperm-ovarian fluid and sperm-egg interactions in these genomic regions. Mapping of the SNPs on these LGs to the rainbow trout genome revealed two genes that affect fertility in humans and represent candidate genes for further studies. Our results thereby provide a novel contribution to the understanding of the mechanism of CFC.
Intimate Partner Abuse (IPA), a major social problem, can lead to mental health conditions and is implicated in 30 % of female and 5 % of male homicide deaths. We hypothesized that due to distinct relationship structures and power dynamics which are immersed in varying sociocultural contexts, victims of male-male, female-female and female-male dyads experience different patterns of IPA. Our objectives were: (1) To examine the demographic and clinical characteristics of victims of male victim-male abuser (M-M), female victim-male abuser (F-M), male victim-female abuser (M-F), and female victim-female abuser (F-F) dyads. (2) To compare patterns of IPA reported by the victims in these groups. Out of 397 subjects in the general population that attempted this Internet-based study, 214 English-speaking subjects were older than 18 years, had experienced IPA, and provided complete information for the analysis. Victims of IPA were screened and specific methods of abuse were evaluated. M-Ms were significantly more educated (70 %) than other groups. F-Fs experienced more abuse before age 18 by a parent or relative. F-Fs experienced the most physical abuse while M-Ms the least (p = 0.004). Physical abuse or threats of abuse in front of children was reported more in F-Fs (p < 0.01) and least in M-Ms. IPA patterns differ significantly with F-Fs presenting the most physical profile and M-Ms presenting the least.
Abstract Dopamine D2/D3 receptor availability at rest and its association with individual pain perception was investigated using the [11 C] raclopride PET-method in 24 female Fibromyalgia (FMS) participants with (FMS+, N =11) and without (FMS−, N =13) comorbid depression and in 17 healthy women. Thermal pain thresholds (TPT) and pain responses were assessed outside the scanner. We compared the discriminative capacity, i.e. the individual׳s capacity to discriminate between lower and higher pain intensities and the response criterion, i.e. the subject׳s tendency to report pain during noxious stimulation due to psychological factors. [11 C] raclopride binding potential (BP), defined as the ratio of specifically bound non-displaceable radioligand at equilibrium (BPND ) was used as measure of D2/D3 receptor availability. We found significant group effects of BPND in striatal regions (left ventral striatum, left caudate nucleus and left nucleus accumbens) between FMS+ and FMS− compared to healthy subjects. Correlational analysis showed negative associations between TPT and D2/D3 receptor availability in the left caudate nucleus in FMS-, between TPT and D2/D3 receptor availability in the right caudate nucleus in FMS + and positive associations between TPT and D2/D3 receptor availability in the left putamen and right caudate nucleus in healthy controls. The response criterion was positively associated with D2/D3 receptor availability in the right nucleus accumbens in FMS − and negatively with D2/D3 receptor availability in the left caudate nucleus in healthy controls. Finally, no significant associations between D2/D3 receptor availability and discriminative capacity in any of the groups or regions were determined. These findings provide further support for a disruption of dopaminergic neurotransmission in FMS and implicate DA as important neurochemical moderator of differences in pain perception in FMS patients with and without co-morbid depression.
Social and intrasexual competition for access to food, territory and reproduction is a major selection force acting on male phenotypes. In contrast, its evolutionary consequences for female phenotypes, especially female ornamentation, have been overlooked. Because fighting is costly for individuals, physical indicators of status that are correlated with aggressiveness or fighting ability are predicted to evolve. Under the badge of status hypothesis, individuals are predicted to attack unknown rivals that present signals of similar size or intensity more vigorously than dissimilar rivals. We used blue tits, , to test whether UV/blue and yellow coloration mediates female aggression. We exposed territorial birds to two female blue tit decoys during nest building: one had a UV/blue crown with an enhanced UV signal (UV+) and the other had a reduced UV signal (UV−). We found that resident females with higher UV signal more often landed on the cage containing the UV+ decoys whereas females with a lower UV signal more often landed on the cage containing the UV− decoys. This result suggests that UV/blue crown coloration is a badge of status and supports the hypothesis that female–female competition can generate or maintain female ornamentation. Resident females with darker yellow chests also attacked the decoys with greater intensity. Previous studies suggest that brighter yellow females invest more in reproduction and consequently could be more sexually attractive. So, this last result may be explained by a higher motivation of darker yellow females or a trade-off between aggressiveness and female investment in reproduction.
Female–female aggression and its functions are poorly understood compared with male–male aggression. Here, we examined the role of female–female aggression in mate defence in an Asian agamid lizard, , in which male neighbours are valuable to females in both mating success and resource defence. We provided three social contexts by pairing a resident female with either a neighbour male, unfamiliar male or unfamiliar female, then introduced a tethered unknown female (intruder). We carried out our experiments during and outside the mating season to test the links between female–female aggression and mate defence. The aggressive responses of resident females in these different social contexts were compared by quantifying variation in their territorial displays. Resident females were faster to display to the intruder in the presence of a neighbour male compared with both the unfamiliar male and female. We also found that female lizards signalled faster in the presence of the neighbour male than the other contexts, but only during the mating season. To separate the effects of familiarity from those of sex, we carried out a second experiment in which we paired a resident female with a neighbour male or neighbour female, before introducing a tethered unfamiliar female. In this experiment, resident females responded sooner to intruder females when paired with the neighbour male, although signalling speeds were equivalent. Taken together, our results suggest female–female aggression is used for both resource and mate defence, and so might be under direct selection. Our study highlights that female aggression more broadly requires further work.
Male primates living in multimale groups tend to direct mate and mate-guarding choices toward females of high reproductive value, i.e., high-ranking, parous females, or females with which they share strong bonds. Little is known, however, about the constraints that may limit male mate-guarding choices (the costs of this behavior) and the influence of the females’ quality on male investment in mate-guarding. We aimed to study the effects of female rank, parity status, and male–female social bond strength on the costs of and investment in mate-guarding by males. We carried out our study during two reproductive seasons on three groups of wild long-tailed macaques in Indonesia. We combined behavioral observations on male locomotion and activity with noninvasive measurements of fecal glucocorticoids (fGC). Males spent less time feeding when mate-guarding nulliparous females than when mate-guarding parous females and tended to have higher fGC levels when mate-guarding low-ranking nulliparous females than when mate-guarding high-ranking nulliparous ones. Evolution should thus favor male choice for high-ranking parous females because such a decision brings benefits at proximate (reduced costs of mate-guarding) and ultimate (higher reproductive value) levels. Further, male investment in mate-guarding was flexible and contingent on female reproductive and social value. Males were more vigilant and more aggressive toward other males when mate-guarding females to which they were strongly bonded and/or high-ranking ones than when mate-guarding other females. Our findings bring a new dimension to the study of mate choice by showing that males not only mate preferentially with high-quality females but may also aim to secure paternity with these females through optimized monopolization.