A Worldwide Internet Study Based on Implicit Association Test Revealed a Higher Prevalence of Adult Males' Androphilia than Ever Reported Before.

BACKGROUND: Social constrictions or the lack of a clear awareness about one's sexual orientation may influence the ability of individuals to explicitly declare their sexual preferences. Thus, the actual prevalence of males' sexual attraction toward adult males, which is estimated by studies relying only on explicit questionnaires, may be biased. Conversely, the implicit measurement of androphilia may be a promising method to obtain more reliable data. AIM: In the present work, explicit and implicit methods have been used to investigate the rates of explicit nonheterosexuality and implicit androphilia in a large sample of adult males from all around the world. For implicit androphilia, a rate consistent across the continents and close to that predicted by recent genetic models (about 15%) was expected. In contrast, for self-declared homosexuality, a lower and more variable rate was expected. METHODS: A sample of 1,050 participants was recruited through an online platform. All participants completed a short biographical questionnaire, an Autobiographical-Implicit Association Test, the Sexual Preference-Implicit Association Test, and an explicit measure of sexual orientation. The answers to these measures were used to explore explicit sexual orientation and implicit androphilia across six main geographical areas (Middle East and Africa, South America, North America, Asia, Europe, and Oceania). OUTCOMES: The main outcome measures were the D score at the Sexual Preference-Implicit Association Test and the scores at the explicit measure of sexual orientation. RESULTS: The rate of nonheterosexuality, which can be found using explicit measures, is rather low, variable (from 6.3% to 11.4%), and influenced by cultural factors. In contrast, the prevalence of androphilia resulting from implicit methods is higher and consistent across geographical areas (from 14.4% to 17.6%). CLINICAL IMPLICATIONS: Studying the diffusion of adult males' androphilia may be useful to better understand sexual behaviors and preferences and to develop effective health promotion programs among males who have sex with males. STRENGTHS & LIMITATIONS: The large and cross-cultural sample and the use of both implicit and explicit measures allowed for obtaining a detailed picture of adult males' sexual orientation and androphilia. The main limitations were the Web-based characteristics of the protocol and the lack of an investigation of actual sexual behaviors. CONCLUSION: Compared with the explicit measurement of nonheterosexuality, the implicit measurement of sexual preferences showed a prevalence of androphilia among adult males that is higher, more stable across continents, and more consistent with the predictions of recent genetic models. Colledani D,A. Camperio Ciani Worldwide Internet Study Based on Implicit Association Test Revealed a Higher Prevalence of Adult Males' Androphilia than Ever Reported Before. J Sex Med 2021;18:4-16.

Selective reaching in macaques: evidence for action-centred attention.

When a monkey selects a piece of food lying on the ground from among other viable objects in the near vicinity, only the desired item governs the particular pattern and direction of the animal's reaching action. It would seem then that selection is an important component controlling the animal's action. But, we may ask, is the selection process in such cases impervious to the presence of other objects that could constitute potential obstacles to or constraints on movement execution? And if it is, in fact, pervious to other objects, do they have a direct influence on the organization of the response? The kinematics of macaques' reaching movements were examined by the current study that analysed some exemplars as they selectively reached to grasp a food item in the absence as well as in the presence of potential obstacles (i.e., stones) that could affect the arm trajectory. Changes in movement parameterization were noted in temporal measures, such as movement time, as well as in spatial ones, such as paths of trajectory. Generally speaking, the presence of stones in the vicinity of the acting hand stalled the reaching movement and affected the arm trajectory as the hand veered away from the stone even when it was not a physical obstacle. We concluded that nearby objects evoke a motor response in macaques, and the attentional mechanisms that allow for a successful action selection are revealed in the reaching path. The data outlined here concur with human studies indicating that potential obstacles are internally represented, a finding implying basic cognitive operations allowing for action selection in macaques.

Implicit measurements of sexual preference in self-declared heterosexual men: a pilot study on the rate of androphilia in Italy.

INTRODUCTION: An unambiguous measurement of the rate of nonheterosexuality in the male population (male bisexuality and homosexuality) is essential to estimate the health risks associated with same-sex sexual behavior and to scale social and health programs for these citizens. However, self-reported questionnaires on explicit measures of sexual orientation yield significant underestimations of nonheterosexuality. A necessary prerequisite for nonheterosexual preference is androphilia (sexual-erotic attraction to males), which can be explored through psychological tests. AIMS: This study, using a pilot sample, investigates the possibility to inventory the frequency of male androphilia in the general population through a sexual preference implicit association test (sp-IAT). This test is a classical IAT that is based on an association of pictures and words and is easily portable. METHODS: First we conducted a preliminary validation of the specific IAT protocol on 24 control subjects; then, we examined a sample of 150 adult males in Italy as a pilot study. The subjects responded to the sp-IAT and completed the explicit Kinsey scale questionnaire. MAIN OUTCOME MEASURES: Kinsey scale scores and D value of sp-IAT for both preliminary and pilot sample. RESULTS: On the explicit Kinsey scale, 2.7% of the sample declared themselves to be sexually attracted to men, corresponding to previous explicit samplings of the Italian homosexual male population. However, the sp-IAT identified that 11.3% of self-declared gynephilic heterosexuals showed a moderate to strong androphilia with a significant effect size (D) always below -0.2, and another 5.6% of the heterosexual sample showed no preference for females (D between -0.2 and 0). CONCLUSION: The Kinsey questionnaire strongly dichotomized the responses as either attracted to females or attracted to men, whereas the sp-IAT showed a wider distribution of responses from gynephilia to androphilia. In conclusion, the sp-IAT could be a novel and unambiguous instrument useful to ascertain androphilia population prevalence as a proxy for possible male nonheterosexuality. Camperio Ciani A and Battaglia U. Implicit measurements of sexual preference in self-declared heterosexual men: A pilot study on the rate of androphilia in Italy. J Sex Med 2014;11:2207-2217.

How posture affects macaques' reach-to-grasp movements.

Although there is a wealth of behavioral data regarding grasping movements in non-human primates, how posture influences the kinematics of prehensile behavior is not yet clearly understood. The purpose of this study was to examine and compare kinematic descriptions of grip behaviors while primates (macaque monkeys) were in a sitting posture or when stopping after quadrupedal locomotion (i.e., tripedal stance). Video footage taken while macaques grasped objects was analyzed frame-by-frame using digitalization techniques. Each of the two grip types considered (power and precision grips) was found to be characterized by specific, distinct kinematic signatures for both the reaching and the grasping components when those actions were performed in a sitting position. The grasping component did not differentiate in relation to the type of grip that was needed when, instead, the prehensile action took place in a tripedal stance. Quadrupedal locomotion affected the concomitant organization of prehensile activities determining in fact a similar kinematic patterning for the two grips regardless of the size of the object to be grasped. It is suggested that using a single kinematic grip patterning for all prehensile activities might be both the by-product of planning a grasping action while walking and a way to simplify motor programming during unstable tripedal stance.

Reaching and grasping behavior in Macaca fascicularis: a kinematic study.

The prehensile hand is one of the major traits distinguishing primates from other mammal species. All primates, in fact, are able to grasp an object and hold it in part or entirely using a single hand. Although there is a wealth of behavioral data regarding grasping movements in humans and apes, there is relatively little material on macaques, the animal model often used to investigate neuronal mechanisms responsible for grip control in humans. To date, evidence regarding free-ranging macaques is confined to observational data, while quantitative reports describe studies carried out in laboratory settings or in captivity. The purpose of the present study was to provide the first kinematic descriptions of basic grip behavior with regard to precision and power grips in free-ranging macaque monkeys. Video footage of those animals grasping objects was analyzed frame-by-frame using digitalization techniques. The results revealed that the two types of grips considered are each characterized by specific kinematic signatures. It was also found that hand kinematics was scaled depending on the type of grasp needing to be adopted and the intrinsic properties of the object to be grasped. In accordance with data concerning humans, these findings indicate that the intrinsic features of an object affect the planning and control of reach-to-grasp movements even in free-ranging macaques. The data presented here take research in the field of comparative reach-to-grasp kinematics in human and non-human primates another step forward as they are based on precise measurements of spontaneous grasping movements by animals living/acting in their natural environment.

Sexual offenses and the brain.

Sexual offenses are a great concern worldwide due to the devastating physical and psychological consequences the victims of such crimes often experience. It is an important task to investigate potential mechanisms that may underlie sexual offending and predispose an individual for such antisocial behavior. Advanced techniques in neuroscience are increasingly used to uncover biomarkers in psychiatric disorders and organic brain disease. As this type of research is flourishing, preliminary studies with the aim to explore the neural basis of sex offenders have started to appear. To this purpose, researchers began to study the brain's structural and functional changes and the neurocognitive profiles of sex offenders, in comparison to nonoffenders and nonsex offenders, or among different subtypes of sex offenders. Most of the research to date has focused on pedophilia, with some inconsistent findings, which hampers the translation of the results into the forensic and clinical context. Any attempt to increase convergent evidence may profit from the harmonization of data analysis and avoidance of methodological inconsistencies, which can account for the different results across studies. Today, uncovering the neural basis of sex offences has to become a priority, not only for clinical interventions, but might also be important knowledge for crime prevention.

Acquired Pedophilia: international Delphi-method-based consensus guidelines.

Idiopathic and acquired pedophilia are two different disorders with two different etiologies. However, the differential diagnosis is still very difficult, as the behavioral indicators used to discriminate the two forms of pedophilia are underexplored, and clinicians are still devoid of clear guidelines describing the clinical and neuroscientific investigations suggested to help them with this difficult task. Furthermore, the consequences of misdiagnosis are not known, and a consensus regarding the legal consequences for the two kinds of offenders is still lacking. The present study used the Delphi method to reach a global consensus on the following six topics: behavioral indicators/red flags helpful for differential diagnosis; neurological conditions potentially leading to acquired pedophilia; neuroscientific investigations important for a correct understanding of the case; consequences of misdiagnosis; legal consequences; and issues and future perspectives. An international and multidisciplinary board of scientists and clinicians took part in the consensus statements as Delphi members. The Delphi panel comprised 52 raters with interdisciplinary competencies, including neurologists, psychiatrists, neuropsychologists, forensic psychologists, expert in ethics, etc. The final recommendations consisted of 63 statements covering the six different topics. The current study is the first expert consensus on a delicate topic such as pedophilia. Important exploitable consensual recommendations that can ultimately be of immediate use by clinicians to help with differential diagnosis and plan and guide therapeutic interventions are described, as well as future perspectives for researchers.

Factors associated with higher fecundity in female maternal relatives of homosexual men.

INTRODUCTION: Recent evidence suggests that sexually antagonistic genetic factors in the maternal line promote homosexuality in men and fecundity in female relatives. However, it is not clear if and how these genetic factors are phenotypically expressed to simultaneously induce homosexuality in men and increased fecundity in their mothers and maternal aunts. AIMS: The aim of the present study was to investigate the phenotypic expression of genetic factors that could explain increased fecundity in the putative female carriers. METHODS: Using a questionnaire-based approach, which included also the Big Five Questionnaire personality inventory based on the Big Five theory, we investigated fecundity in 161 female European subjects and scrutinized possible influences, including physiological, behavioral, and personality factors. We compared 61 female probands who were either mothers or maternal aunts of homosexual men. One hundred females who were mothers or aunts of heterosexual men were used as controls. MAIN OUTCOME MEASURES: Personality traits, retrospective physiological and clinical data, behavior and opinions on fecundity-related issues were assessed and analyzed to illustrate possible effects on fecundity between probands and control females. RESULTS: Our analysis showed that both mothers and maternal aunts of homosexual men show increased fecundity compared with corresponding maternal female relatives of heterosexual men. A two-step statistical analysis, which was based on t-tests and multiple logistic regression analysis, showed that mothers and maternal aunts of homosexual men (i) had fewer gynecological disorders; (ii) had fewer complicated pregnancies; (iii) had less interest in having children; (iv) placed less emphasis on romantic love within couples; (v) placed less importance on their social life; (vi) showed reduced family stability; (vii) were more extraverted; and (viii) had divorced or separated from their spouses more frequently. CONCLUSIONS: Our findings are based on a small sample and would benefit from a larger replication, however they suggest that if sexually antagonistic genetic factors that induce homosexuality in males exist, the factors might be maintained in the population by contributing to increased fecundity greater reproductive health, extraversion, and a generally relaxed attitude toward family and social values in females of the maternal line of homosexual men.

Attitudes towards urban howler monkeys (Alouatta caraya) in Paraguay.

Increasing urbanisation is encroaching into natural habitats and sometimes forcing wildlife into urban centres. Whether or not wildlife can thrive in an urban environment is dependent on many factors, one of which is how the species is perceived by local people. This study focuses on the city of Pilar in south-west Paraguay, which is home to a population of urban-dwelling black and gold howler monkeys (Alouatta caraya). Using semi-structured interviews, we assessed peoples' attitudes towards the presence of howlers, whether they perceived the monkeys to cause problems in the city, what they believed were the biggest threats to the monkeys, and whether they felt that the presence of monkeys in the city was compatible with their way of life in the long term. Overall, we found that the majority of interviewees had positive attitudes towards the monkeys, believing that they brought benefits to the city and that they should be protected from potential risks in the urban environment. Our results provide the basis for collaborative, community-based development of management strategies for the long-term survival of these urban monkeys.

Idiopathic and acquired pedophilia as two distinct disorders: an insight from neuroimaging.

Pedophilia is a disorder of public concern because of its association with child sexual offense and recidivism. Previous neuroimaging studies of potential brain abnormalities underlying pedophilic behavior, either in idiopathic or acquired (i.e., emerging following brain damages) pedophilia, led to inconsistent results. This study sought to explore the neural underpinnings of pedophilic behavior and to determine the extent to which brain alterations may be related to distinct psychopathological features in pedophilia. To this aim, we run a coordinate based meta-analysis on previously published papers reporting whole brain analysis and a lesion network analysis, using brain lesions as seeds in a resting state connectivity analysis. The behavioral profiling approach was applied to link identified regions with the corresponding psychological processes. While no consistent neuroanatomical alterations were identified in idiopathic pedophilia, the current results support that all the lesions causing acquired pedophilia are localized within a shared resting state network that included posterior midlines structures, right inferior temporal gyrus and bilateral orbitofrontal cortex. These regions are associated with action inhibition and social cognition, abilities that are consistently and severely impaired in acquired pedophiles. This study suggests that idiopathic and acquired pedophilia may be two distinct disorders, in line with their distinctive clinical features, including age of onset, reversibility and modus operandi. Understanding the neurobiological underpinnings of pedophilic behavior may contribute to a more comprehensive characterization of these individuals on a clinical ground, a pivotal step forward for the development of more efficient therapeutic rehabilitation strategies.

Male homosexuality: nature or culture?

INTRODUCTION: Debate continues on whether or not male homosexuality (MH) is a result of biological or cultural factors. The debate persists despite the fact that these two sides have different abilities to create a scientific environment to support their cause. Biological theorists produced evidence, however, that these are not always robust. On the other hand, social theorists, without direct evidence confirming their positions, criticize, with good argument, methods and results of the other side. The aim of this Controversy is to understand the reasons of both perspectives. METHODS: Two scientists (R.B. and A.C.C.) with expertise in the area of biology of MH were asked to contribute their opinions. The nurture position is discussed by a third expert in sexology (J.B.). MAIN OUTCOME MEASURE: Expert opinion supported by the critical review of the currently available literature. RESULT: The role of the Controversy's editor (E.A.J.) is to highlight the strengths and weaknesses of both sides. The two experts of the biological issue answer with their data to the questions: "Is male homosexuality partly explainable by immunology?" and "How is male homosexuality a Darwinian paradox?", respectively. Genetic and immunological factors, birth order, and fertility of relatives are largely discussed. Finally, the expert sustaining the idea that culture and experiences are important determining factors in sexual orientation used a psychosocial and holistic perspective to explain his position. CONCLUSIONS: The JSM's readers should recognize that there are several biological factors in MH. However, these findings do not seem to be able to explain all cases of homosexuality. Some others may be due to particular environmental factors. The issue is complicated and multifactorial, suggesting that further research should be undertaken to produce the final answer to the question raised in this Controversy section.

New evidence of genetic factors influencing sexual orientation in men: female fecundity increase in the maternal line.

There is a long-standing debate on the role of genetic factors influencing homosexuality because the presence of these factors contradicts the Darwinian prediction according to which natural selection should progressively eliminate the factors that reduce individual fecundity and fitness. Recently, however, Camperio Ciani, Corna, and Capiluppi (Proceedings of the Royal Society of London, Series B: Biological Sciences, 271, 2217-2221, 2004), comparing the family trees of homosexuals with heterosexuals, reported a significant increase in fecundity in the females related to the homosexual probands from the maternal line but not in those related from the paternal one. This suggested that genetic factors that are partly linked to the X-chromosome and that influence homosexual orientation in males are not selected against because they increase fecundity in female carriers, thus offering a solution to the Darwinian paradox and an explanation of why natural selection does not progressively eliminate homosexuals. Since then, new data have emerged suggesting not only an increase in maternal fecundity but also larger paternal family sizes for homosexuals. These results are partly conflicting and indicate the need for a replication on a wider sample with a larger geographic distribution. This study examined the family trees of 250 male probands, of which 152 were homosexuals. The results confirmed the study of Camperio Ciani et al. (2004). We observed a significant fecundity increase even in primiparous mothers, which was not evident in the previous study. No evidence of increased paternal fecundity was found; thus, our data confirmed a sexually antagonistic inheritance partly linked to the X-chromosome that promotes fecundity in females and a homosexual sexual orientation in males.

Profiling acquired pedophilic behavior: Retrospective analysis of 66 Italian forensic cases of pedophilia.

Neurological disorders can be mis-diagnosed as psychiatric ones. This might happen to pedophilia emerging as a symptom of brain insult (i.e. acquired pedophilic behavior). This paper aims to delineate a behavioral profile that might help to identify defendants whose pedophilic behavior is likely to be the consequence of a neurological disorder. Through a systematic review of the literature, seventeen clinical and behavioral variables of the modus operandi and victimology that can distinguish between acquired and developmental pedophilic behavior have been collected. Seven of these were found to be consistent behavioral indicators (i.e. red flags) for acquired pedophilia. Cluster hierarchical analysis on the seventeen variables collected through the systematic review of the literature on cases of acquired pedophilic behavior was applied to a new dataset including 66 Italian closed cases of pedophilia. Stepwise regression and correlation analyses were carried out to further examine the differences between the clusters identified in the cluster analysis. Results revealed that the new sample was partitioned into two clusters. Individuals with ascertained acquired pedophilia were grouped together. The clusters widely differed for the prevalence of red flags (mean number of red flags in each cluster: 2.14 ±â€¯0.79 vs 4.96 ±â€¯0.93, p < 0.001), while no between cluster difference emerged for the other clinical and behavioral variables. Regression analysis provided a robust model that included the three most significant red flags that explain over 64.5% of the variance (absence of masking, spontaneous confession and offenders older age). An organic origin of pedophilic behavior should be suspected if red flags are present in a defendant charged with pedophilia. In those cases, an in depth trans-disciplinary neuroscientific investigation is advocated. The behavioral profile identified might help to provide a proper assessment of defendants.

Possible Balancing Selection in Human Female Homosexuality.

A growing number of researchers suggest that female homosexuality is at least in part influenced by genetic factors. Unlike for male homosexuality, few familial studies have attempted to explore maintenance of this apparently fitness-detrimental trait in the population. Using multiple recruitment methods, we explored fecundity and sexual orientation within the pedigrees of 1,458 adult female respondents. We compared 487 homosexual and 163 bisexual with 808 heterosexual females and 30,203 of their relatives. Our data suggest that the direct fitness of homosexual females is four times lower than the direct fitness of heterosexual females of corresponding ages. The prevalence of nonheterosexuality within the homosexual female respondents' families (2.83%) appear to be more than four times higher than the basal prevalence in the Italian population (0.63%). Pedigree size and relative fecundity in both the paternal and maternal sides of the homosexual women's families were significantly higher than in the heterosexuals' families. If confirmed, the relative average fecundity increase within the family seems to offset the loss in fitness due to the low direct fitness of homosexual females. Therefore, the balanced fecundity in the homosexual females' families may allow the trait to be maintained at a low-frequency equilibrium in the population.

Response: Avuncularity and Kin Selection in Homosexuals: A Problematic Test or a Problematic Hypothesis?

Here we respond to Vasey et al.'s critical comments regarding our article, "Societal norms rather than sexual orientation influence kin altruism and avuncularity in tribal Urak-Lawoi, Italian, and Spanish adult males" (Camperio Ciani, Battaglia, & Liotta, 2015 , JSR doi:10.1080/00224499.2014.993748). The first regards the selection of the Urak-Lawoi population of Ko Lipeh, which is considered too modern and touristic to be adequate to test the kin selection and avuncular hypothesis for homosexuality. We provide historical evidence of the contrary, and show that the population at the inception of our 10 years research was indeed primitive and tribal, and probands actually grew and lived in such a society. Only a few years after the 2004 tsunami, the island was developed and invaded by mass tourism. The second comment regarded the statistical analysis and interpretation of data. We show that we consistently and conservatively considered the effects of all confounding variables, both with comparative tests, and by a series of multivariate regression analyses. This was the orthodox procedure approved by all other reviewers. In conclusion, even addressing these comments, we maintain that the kin selection and avuncularity hypothesis for homosexuality is not supported by empirical data even in this primitive and tribal society.

Societal Norms Rather Than Sexual Orientation Influence Kin Altruism and Avuncularity in Tribal Urak-Lawoi, Italian, and Spanish Adult Males.

Homosexual males could balance their low fitness by increasing benefits to relatives either through kin-directed altruism or by avuncularity (altruistic behavior toward the children of siblings). Evidence in support of kin selection and avuncularity includes the fact that homosexuals seem to be more empathic and altruistic than heterosexuals. Other studies have not confirmed behaviors that increase kin altruism in homosexuals. We explored altruistic behavior and avuncularity in a sample of 278 subjects, either homosexual or heterosexual, from three populations: Italian, Spanish, and Urak-Lawoi, a Southeast Asian tribal population. Among the Urak-Lawoi, the kathoeys, androphilic men who dress and behave as women, were compared with heterosexuals. All populations were rated for societal norms on the expression of affiliative behavior. No greater kin altruism or avuncularity among the kathoeys or in homosexuals in either Mediterranean population was found. Greater avuncularity and kin-directed altruism, independent of sexual orientation, were found among the Urak-Lawoi, and these traits were the least prevalent among the Italians, corresponding to different societal norms. The increase in kin altruism and avuncularity was associated in all males with societal differences and norms on general altruism toward nonkin children, suggesting it is not an adaptive design to maintain homosexuality in humans.

Human homosexuality: a paradigmatic arena for sexually antagonistic selection?

Sexual conflict likely plays a crucial role in the origin and maintenance of homosexuality in our species. Although environmental factors are known to affect human homosexual (HS) preference, sibling concordances and population patterns related to HS indicate that genetic components are also influencing this trait in humans. We argue that multilocus, partially X-linked genetic factors undergoing sexually antagonistic selection that promote maternal female fecundity at the cost of occasional male offspring homosexuality are the best candidates capable of explaining the frequency, familial clustering, and pedigree asymmetries observed in HS male proband families. This establishes male HS as a paradigmatic example of sexual conflict in human biology. HS in females, on the other hand, is currently a more elusive phenomenon from both the empirical and theoretical standpoints because of its fluidity and marked environmental influence. Genetic and epigenetic mechanisms, the latter involving sexually antagonistic components, have been hypothesized for the propagation and maintenance of female HS in the population. However, further data are needed to truly clarify the evolutionary dynamics of this trait.

Intersegmental Coordination in the Kinematics of Prehension Movements of Macaques.

The most popular model to explain how prehensile movements are organized assumes that they comprise two "components", the reaching component encoding information regarding the object's spatial location and the grasping component encoding information on the object's intrinsic properties such as size and shape. Comparative kinematic studies on grasping behavior in the humans and in macaques have been carried out to investigate the similarities and differences existing across the two species. Although these studies seem to favor the hypothesis that macaques and humans share a number of kinematic features it remains unclear how the reaching and grasping components are coordinated during prehension movements in free-ranging macaque monkeys. Twelve hours of video footage was filmed of the monkeys as they snatched food items from one another (i.e., snatching) or collect them in the absence of competitors (i.e., unconstrained). The video samples were analyzed frame-by-frame using digitization techniques developed to perform two-dimensional post-hoc kinematic analyses of the two types of actions. The results indicate that only for the snatching condition when the reaching variability increased there was an increase in the amplitude of maximum grip aperture. Besides, the start of a break-point along the deceleration phase of the velocity profile correlated with the time at which maximum grip aperture occurred. These findings suggest that macaques can spatially and temporally couple the reaching and the grasping components when there is pressure to act quickly. They offer a substantial contribution to the debate about the nature of how prehensile actions are programmed.