A Queueing Theoretic Approach to Decoupling Inventory

This paper investigates the performance of different hybrid push-pull systems with a decoupling inventory at the semi-finished products and reordering thresholds. Raw materials are ‘pushed’ into the semi-finished product inventory and customers ‘pull’ products by placing orders. Furthermore, production of semi-finished products starts when the inventory goes below a certain level, referred to as the threshold value and stops when the inventory attains stock capacity. As performance of the decoupling stock is critical to the overall cost and performance of manufacturing systems, this paper introduces a Markovian model for hybrid push-pull systems. In particular, we focus on a queueing model with two buffers, thereby accounting for both the decoupling stock as well as for possible backlog of orders. By means of numerical examples, we assess the impact of different reordering policies, irregular order arrivals, the set-up time distribution and the order processing time distribution on the performance of hybrid push-pull systems

Long-Term Follow-Up of Transsexual Persons Undergoing Sex Reassignment Surgery: Cohort Study in Sweden

CONTEXT: The treatment for transsexualism is sex reassignment, including hormonal treatment and surgery aimed at making the person's body as congruent with the opposite sex as possible. There is a dearth of long term, follow-up studies after sex reassignment. OBJECTIVE: To estimate mortality, morbidity, and criminal rate after surgical sex reassignment of transsexual persons. DESIGN: A population-based matched cohort study. SETTING: Sweden, 1973-2003. PARTICIPANTS: All 324 sex-reassigned persons (191 male-to-females, 133 female-to-males) in Sweden, 1973-2003. Random population controls (10:1) were matched by birth year and birth sex or reassigned (final) sex, respectively. MAIN OUTCOME MEASURES: Hazard ratios (HR) with 95% confidence intervals (CI) for mortality and psychiatric morbidity were obtained with Cox regression models, which were adjusted for immigrant status and psychiatric morbidity prior to sex reassignment (adjusted HR [aHR]). RESULTS: The overall mortality for sex-reassigned persons was higher during follow-up (aHR 2.8; 95% CI 1.8-4.3) than for controls of the same birth sex, particularly death from suicide (aHR 19.1; 95% CI 5.8-62.9). Sex-reassigned persons also had an increased risk for suicide attempts (aHR 4.9; 95% CI 2.9-8.5) and psychiatric inpatient care (aHR 2.8; 95% CI 2.0-3.9). Comparisons with controls matched on reassigned sex yielded similar results. Female-to-males, but not male-to-females, had a higher risk for criminal convictions than their respective birth sex controls. CONCLUSIONS: Persons with transsexualism, after sex reassignment, have considerably higher risks for mortality, suicidal behaviour, and psychiatric morbidity than the general population. Our findings suggest that sex reassignment, although alleviating gender dysphoria, may not suffice as treatment for transsexualism, and should inspire improved psychiatric and somatic care after sex reassignment for this patient group

Standards of Care for the Health of Transgender and Gender Diverse People, Version 8

Background: Transgender healthcare is a rapidly evolving interdisciplinary field. In the last decade, there has been an unprecedented increase in the number and visibility of transgender and gender diverse (TGD) people seeking support and gender-affirming medical treatment in parallel with a significant rise in the scientific literature in this area. The World Professional Association for Transgender Health (WPATH) is an international, multidisciplinary, professional association whose mission is to promote evidence-based care, education, research, public policy, and respect in transgender health. One of the main functions of WPATH is to promote the highest standards of health care for TGD people through the Standards of Care (SOC). The SOC was initially developed in 1979 and the last version (SOC-7) was published in 2012. In view of the increasing scientific evidence, WPATH commissioned a new version of the Standards of Care, the SOC-8. Aim: The overall goal of SOC-8 is to provide health care professionals (HCPs) with clinical guidance to assist TGD people in accessing safe and effective pathways to achieving lasting personal comfort with their gendered selves with the aim of optimizing their overall physical health, psychological well-being, and self-fulfillment. Methods: The SOC-8 is based on the best available science and expert professional consensus in transgender health. International professionals and stakeholders were selected to serve on the SOC-8 committee. Recommendation statements were developed based on data derived from independent systematic literature reviews, where available, background reviews and expert opinions. Grading of recommendations was based on the available evidence supporting interventions, a discussion of risks and harms, as well as the feasibility and acceptability within different contexts and country settings. Results: A total of 18 chapters were developed as part of the SOC-8. They contain recommendations for health care professionals who provide care and treatment for TGD people. Each of the recommendations is followed by explanatory text with relevant references. General areas related to transgender health are covered in the chapters Terminology, Global Applicability, Population Estimates, and Education. The chapters developed for the diverse population of TGD people include Assessment of Adults, Adolescents, Children, Nonbinary, Eunuchs, and Intersex Individuals, and people living in Institutional Environments. Finally, the chapters related to gender-affirming treatment are Hormone Therapy, Surgery and Postoperative Care, Voice and Communication, Primary Care, Reproductive Health, Sexual Health, and Mental Health. Conclusions: The SOC-8 guidelines are intended to be flexible to meet the diverse health care needs of TGD people globally. While adaptable, they offer standards for promoting optimal health care and guidance for the treatment of people experiencing gender incongruence. As in all previous versions of the SOC, the criteria set forth in this document for gender-affirming medical interventions are clinical guidelines; individual health care professionals and programs may modify these in consultation with the TGD person

Long-term psychosexual and anatomical outcome after vaginal dilation or vaginoplasty: a comparative study

Introduction. In patients with disorders of sex development requiring creation of a neovagina, a number of techniques are available, including surgical vaginoplasty and self-dilation therapy. Vaginal dilation therapy has been recommended as a first-line treatment because of its less invasive character and high success rate. However, no data exist on long-term psychosexual functioning after vaginal dilation as compared with that after vaginal surgery. Aims. The aim of this study is to compare the psychosexual and anatomical outcome of women with congenital vaginal hypoplasia followed in the same clinical setting after vaginoplasty with that after vaginal dilation. Methods. The sexual quality of life of 35 women at least 2 years after vaginoplasty (N = 15), vaginal dilation therapy (N = 8), or coital dilation/no treatment (N = 12) was investigated and compared with the Dutch test validation population (as control). Main Outcome Measures. Psychosexual functioning was assessed with the Female Sexual Function Index, the Female Sexual Distress Scale-Revised, and a semi-structured interview. A gynecological examination was performed to determine the anatomical outcome after both vaginal treatment regimens. Results. After either treatment, 26% of these women had a shortened vaginal length of less than 6.6 cm, i.e., more than two standard deviations below the published mean value (9.6 +/- 1.5 cm). Irrespective of the treatment, 47% of the patients had (a) sexual dysfunction(s) and experienced sexual distress. However, after vaginoplasty, patients reported significantly more problems with lubrication (P = 0.025) than after self-dilation therapy. Conclusion. Both psychological and physical factors are predisposing for sexual difficulties. To optimize psychosexual comfort, the clinical management of women with vaginal hypoplasia needs to be multidisciplinary and individually tailored. With high success rates reported, vaginal dilation should remain the cornerstone of treatment