Polynomial Time Algorithms for Branching Markov Decision Processes and Probabilistic Min(Max) Polynomial Bellman Equations

We show that one can approximate the least fixed point solution for a multivariate system of monotone probabilistic max(min) polynomial equations, referred to as maxPPSs (and minPPSs, respectively), in time polynomial in both the encoding size of the system of equations and in log(1/epsilon), where epsilon > 0 is the desired additive error bound of the solution. (The model of computation is the standard Turing machine model.) We establish this result using a generalization of Newton's method which applies to maxPPSs and minPPSs, even though the underlying functions are only piecewise-differentiable. This generalizes our recent work which provided a P-time algorithm for purely probabilistic PPSs. These equations form the Bellman optimality equations for several important classes of infinite-state Markov Decision Processes (MDPs). Thus, as a corollary, we obtain the first polynomial time algorithms for computing to within arbitrary desired precision the optimal value vector for several classes of infinite-state MDPs which arise as extensions of classic, and heavily studied, purely stochastic processes. These include both the problem of maximizing and mininizing the termination (extinction) probability of multi-type branching MDPs, stochastic context-free MDPs, and 1-exit Recursive MDPs. Furthermore, we also show that we can compute in P-time an epsilon-optimal policy for both maximizing and minimizing branching, context-free, and 1-exit-Recursive MDPs, for any given desired epsilon > 0. This is despite the fact that actually computing optimal strategies is Sqrt-Sum-hard and PosSLP-hard in this setting. We also derive, as an easy consequence of these results, an FNP upper bound on the complexity of computing the value (within arbitrary desired precision) of branching simple stochastic games (BSSGs)

Book Review: The N Word: Who Can Say It. Who Shouldn’t. And Why

Review of The N Word: Who Can Say It. Who Shouldn’t. And Why by Jabari Asi

Sexual Orientation and Gender Identity Among Donor-Conceived Offspring in the U.S. National Longitudinal Lesbian Family Study from Adolescence to Adulthood

introduction concerns about parents with minoritized sexual identities often focus on the belief that their children will be confused about their gender and report a non-heterosexual orientation compared to children reared by heterosexual parents. yet, few longitudinal studies exist. methods gender identity, gender expression, sexual orientation, and sexual experiences were examined in 75 U.S. donor-conceived offspring (39 assigned females at birth (AFAB) and 36 assigned males at birth (AMAB)) of lesbian parents, when the offspring had reached adulthood (ages 30-33). Additionally, 72 of these offspring (38 AFAB and 34 AMAB) had also completed surveys in adolescence (age 17, data collected 2004-2009) and emerging adulthood (age 25, data collected 2012-2017), which enabled us to examine the developmental pathways of their sexuality. results All AMAB offspring and 94.7% of AFAB offspring who identified as cisgender during adolescence continued to do so during emerging adulthood and adulthood. over time, sexual orientation was more fluid than gender identity, and AFAB offspring were more fluid than AMAB offspring. specifically, considering those who reported the same (heterosexual/straight; lesbian, gay/homosexual; or bisexual+) sexual orientation from adolescence through emerging adulthood to adulthood, 63.9% were AFAB and 82.4% were AMAB. More than half of AFAB offspring and 80.6% of AMAB offspring identified as heterosexual in adulthood, and the vast majority had had sex with a non-transgender man (86.5%) and a non-transgender woman (93.6%), respectively, in the last 5 years.conclusions this is the only study that has followed the biological offspring of lesbian parents from birth to adulthood, prospectively and longitudinally. the results indicate that offspring of lesbian parents are less likely to identify as transgender than the general public, but more likely to identify as LGB or queer. policy Implications As gender and sexual identity development significantly impacts well-being, creating supportive environments for offspring of lesbian parents and increasing public awareness of the connections among developmental milestones, health, and thriving are vital

Greatest Fixed Points of Probabilistic Min/Max Polynomial Equations, and Reachability for Branching Markov Decision Processes?

We give polynomial time algorithms for quantitative (and qualitative) reachability analysis for Branching Markov Decision Processes (BMDPs). Specifically, given a BMDP, and given an initial population, where the objective of the controller is to maximize (or minimize) the probability of eventually reaching a population that contains an object of a desired (or undesired) type, we give algorithms for approximating the supremum (infimum) reachability probability, within desired precision epsilon > 0, in time polynomial in the encoding size of the BMDP and in log(1/epsilon). We furthermore give P-time algorithms for computing epsilon-optimal strategies for both maximization and minimization of reachability probabilities. We also give P-time algorithms for all associated qualitative analysis problems, namely: deciding whether the optimal (supremum or infimum) reachability probabilities are 0 or 1. Prior to this paper, approximation of optimal reachability probabilities for BMDPs was not even known to be decidable. Our algorithms exploit the following basic fact: we show that for any BMDP, its maximum (minimum) non-reachability probabilities are given by the greatest fixed point (GFP) solution g* in [0,1]^n of a corresponding monotone max (min) Probabilistic Polynomial System of equations (max/min-PPS), x=P(x), which are the Bellman optimality equations for a BMDP with non-reachability objectives. We show how to compute the GFP of max/min PPSs to desired precision in P-time. We also study more general Branching Simple Stochastic Games (BSSGs) with (non-)reachability objectives. We show that: (1) the value of these games is captured by the GFP of a corresponding max-minPPS; (2) the quantitative problem of approximating the value is in TFNP; and (3) the qualitative problems associated with the value are all solvable in P-time

Eating Christmas Cookies, Whole-wheat Bread and Frozen Chicken in the Kindergarten: Doing Pedagogy by Other Means

The study presented here explores eating as a pedagogical practice by paying attention to arrangements of things such as Christmas cookies, whole-wheat and white bread, frozen chicken, plates, chairs, tables, and freezers. Through a series of ethnographic research examples from German and Brazilian preschools, it investigates how eating in the kindergarten can be a sensual pleasure, a health risk, an ethnic custom, or a civil right within different local histories. Through specific arrangements of foods and other things, young children are educated to eat with moderation, to change their ethnic dietary habits, or to be "modern citizens". Pedagogy can thus consist of doing public health, doing ethnic identity, or doing citizenship. Eating is an important way of doing pedagogy in early childhood education and care settings. © 2013 Springer Fachmedien Wiesbaden

Asexuality: Classification and characterization

This is a post-print version of the article. The official published version can be obtaineed at the link below.The term “asexual” has been defined in many different ways and asexuality has received very little research attention. In a small qualitative study (N = 4), individuals who self-identified as asexual were interviewed to help formulate hypotheses for a larger study. The second larger study was an online survey drawn from a convenience sample designed to better characterize asexuality and to test predictors of asexual identity. A convenience sample of 1,146 individuals (N = 41 self-identified asexual) completed online questionnaires assessing sexual history, sexual inhibition and excitation, sexual desire, and an open-response questionnaire concerning asexual identity. Asexuals reported significantly less desire for sex with a partner, lower sexual arousability, and lower sexual excitation but did not differ consistently from non-asexuals in their sexual inhibition scores or their desire to masturbate. Content analyses supported the idea that low sexual desire is the primary feature predicting asexual identity

Fat, Queer, Dead: ‘Obesity’ and the Death Drive

That contemporary discourses of the ‘obesity epidemic’ are engaged in the construction of fatness as pathological, immoral and socially undesirable has been the subject much recent critical inquiry within Fat Studies. This paper contributes to that literature with a re-reading of obesity discourse via what queer theorist Lee Edelman (2004) has called ‘reproductive futurism’. Edelman contends that queerness figures the social order's death drive, and is thus abjected in order to assure the reproduction of that social order. This paper argues that, like the queer, fatness is increasingly being figured as anti-social and as that which must be eliminated in the name of a viable future. Framing obesity in this way makes possible an analysis of the presumed ‘threat’ of obesity, frequently referred to, but seldom unpacked, in the existing literature. A comparative analysis of the UK government's Change 4 Life (2009) public health campaign and nineteenth century theories of degeneracy is used to illustrate the cultural anxieties about immorality, disease, civilization and death that undergird both discourses. This analysis suggests the centrality of rationality and self-control, understood as moral, to the reproduction of the social order. Furthermore, reading the ‘obesity epidemic’ as couched in the logic of reproductive futurism opens up potential alternative approaches to fat politics. In the light of Samantha Murray's (2008) critique of the liberal humanist underpinnings of fat activist discourse, this paper considers whether Edelman's advocacy of ‘future-negating’ for queers, offers a productive trajectory for fat politics

Demographic, Psychological, and Social Characteristics of Self-Identified Lesbian, Gay, and Bisexual Adults in a US Probability Sample

Using data from a US national probability sample of self-identified lesbian, gay, and bisexual adults (N = 662), this article reports population parameter estimates for a variety of demographic, psychological, and social variables. Special emphasis is given to information with relevance to public policy and law. Compared with the US adult population, respondents were younger, more highly educated, and less likely to be non-Hispanic White, but differences were observed between gender and sexual orientation groups on all of these variables. Overall, respondents tended to be politically liberal, not highly religious, and supportive of marriage equality for same-sex couples. Women were more likely than men to be in a committed relationship. Virtually all coupled gay men and lesbians had a same-sex partner, whereas the vast majority of coupled bisexuals were in a heterosexual relationship. Compared with bisexuals, gay men and lesbians reported stronger commitment to a sexual-minority identity, greater community identification and involvement, and more extensive disclosure of their sexual orientation to others. Most respondents reported experiencing little or no choice about their sexual orientation. The importance of distinguishing among lesbians, gay men, bisexual women, and bisexual men in behavioral and social research is discussed

Who reports absence of sexual attraction in Britain? Evidence from national probability surveys

There is little evidence about the prevalence of absence of sexual attraction, or the characteristics of people reporting this, often labelled asexuals. We examine this using data from two probability surveys of the British general population, conducted in 1990–1991 and 2000–2001. Interviewers administered face-to-face and self-completion questionnaires to people aged 16–44 years (N = 13,765 in 1990–1991; N = 12,110 in 2000–2001). The proportion that had never experienced sexual attraction was 0.4% (95% CI: 0.3–0.5%) in 2000–2001, with no significant variation by gender or age, versus 0.9% (95% CI: 0.7–1.1%) in 1990–1991; p < 0.0001. Among these 79 respondents in 2000–2001, 28 (40.3% men; 33.9% women) had had sex, 19 (33.5% men; 20.9% women) had child(ren), and 17 (30.1% men; 19.2% women) were married. Three-quarters of asexual men and two-thirds of asexual women considered their frequency of sex ‘about right’, while 24.7% and 19.4%, respectively, ‘always enjoyed having sex’. As well as providing evidence on the distribution of asexuality in Britain, our data suggest that it cannot be assumed that those reporting no sexual attraction are sexually inexperienced or without intimate relationships. We recognise the possibility of social desirability bias given our reliance on self-reported data, but suggest that its effect is not easily predicted regarding absence of sexual attraction

Single parenting: Interventions in the transitional stage

Following divorce or separation, many mother-headed families need to mourn losses, including reduced economic resources. They need to reestablish family rituals, confront such issues as time management and structural changes that can result in scapegoating or over-reliance on a parental child. Normalizing difficulties associated with parenting is important because single parents tend to internalize societal attribution of family difficulties to inadequate family structure rather than developmental stages, limited economic resources, and negative expectations about the capacity of women to head families.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44289/1/10591_2004_Article_BF00891869.pd