Ultracompact monolithic integration of balanced, polarization diversity photodetectors for coherent lightwave receivers

The authors have monolithically integrated an optical front-end on InP for balanced, polarization-diversity coherent lightwave reception which is only 1.3-mm long. Low on-chip insertion loss (<4.5 dB) and balanced photoresponse (1.05:1 or better) are achieved at 1.5-μm wavelength using straightforward, regrowth-free fabrication. Low-capacitance photodetectors (≤0.15 pF) are employed for high bandwidth operation

Socio-demographic and fertility related characteristics and motivations of oocyte donors in eleven European countries

Do the socio-demographic and fertility-related characteristics and motivations of oocyte donors differ in European countries? The socio-demographic and fertility-related characteristics and motivations of oocyte donors differ considerably across countries. There have been no other international studies comparing the characteristics of oocyte donors. Regarding their motivations, most studies indicate mixed motives. The proposed study was a transversal epidemiological study. Data were collected from 63 voluntarily participating assisted reproduction technology centres practising oocyte donation in 11 European countries (Belgium, Czech Republic, Finland, France, Greece, Poland, Portugal, Russia, Spain, UK and Ukraine). The survey was conducted between September 2011 and June 2012 and ran for 16 calendar months depending on the number of cycles of oocyte donation performed at the centre. The sample size was computed in order to allow an estimate of the percentage of a relatively rare characteristic (2) with a precision (95 confidence interval) of 1. The calculation gave 1118 donors. In total, 1423 forms were obtained from oocyte donors. All consecutive donors in these centres filled out an anonymous questionnaire when they started their hormonal stimulation, asking for their socio-demographic and fertility-related characteristics, their motivations and compensation. Population characteristics were described and compared by country of donation. Motives for donation and mean amount of money were compared between countries and according to the donors characteristics. The socio-demographic and fertility-related characteristics and motivations of oocyte donors varied enormously across European countries. The number of received forms corresponded with a participation rate of 61.9 of the cycles performed by the participating centres. Mean age was 27.4 years. About 49 of donors were fully employed, 16 unemployed and 15 student. The motivation in the total group of donors was 47.8 pure altruism, 33.9 altruism and financial, 10.8 pure financial, 5.9 altruism and own treatment and finally 2 own treatment only. About 15 of the donors were egg sharers (patient donors), mainly from the UK and Poland. Women were donating for the first time in 55.4 of cases, for the second time in 20.3 and for the third time in 12.8. The motivation to donate was significantly related to being of foreign origin (P 0.01), age (P 0.001), living in couple or not (P 0.01), level of education (P 0.001) and number of donations (P 0.001). The amount of compensation differed considerably between centres and/or countries. The general donor profile in this study was a well-educated, 27-year-old woman living with her partner and child who mainly donated to help others. The selection of clinics in some countries and the limited participation rate may have led to a bias in donor characteristics. A possible effect of social desirability in the answers by the donors should be taken into account. The diversity of the donor population reflects the differences in European legislation (for example, on anonymity and payment) and economic circumstances. The differences in systems of reimbursement/payment demonstrate the need to have a thorough discussion on the specific meaning of these terms. The study was funded by the European Society for Human Reproduction and Embryology. The authors declare no conflicting interests

The Influence of a Fibrin-Coating Inside a Biodegradable Poly(DL-Lactide-ε-Caprolactone) Nerve Guide on Peripheral Nerve Regeneration

The aim of this study was to evaluate the effect of a fibrin-coating on the inner surface of a biodegradable poly(DL-lactide-E-caprolactone) nerve guide on the speed and quality of the nerve regeneration. The nerve regeneration and orientation of the nerve fibers, as well as the fibrous tissue formation were evaluated. On the short term, nerve regeneration was slightly faster in the non-coated nerve guide. After longer implantation periods (≥ 4 weeks), nerve regeneration in the fibrin-coated nerve guides was characterized by a severe inflammatory response with large numbers of macrophages and polymorphonuclear cells (PMN\u27s). This study clearly demonstrates that nerve regeneration in a fibrin-coated nerve guide is not faster when compared with a non-coated nerve guide, and that nerve regeneration in the fibrin-coated nerve guide is even worse after longer implantation periods

Ultracompact, low-loss directional couplers on InP based on self-imaging by multimode interference

We report extremely compact (494-µm-long 3 dB splitters, including input/output bends), polarization-insensitive, zero-gap directional couplers on InP with a highly multimode interference region that are based on the self-imaging effect. We measured cross-state extinctions better than 28 dB and on-chip insertion losses of 0.5 dB/coupler plus 1 dB/cm guide propagation loss at 1523 nm wavelength

The influence of a fibrin-coating inside a biodegradable poly(DL-lactide-e-caprolactone) nerve guide on peripheral nerve regeneration

The aim of this study was to evaluate the effect of a fibrin-coating on the inner surface of a biodegradable poly(DL-lactide-ε-caprolactone) nerve guide on the speed and quality of the nerve regeneration. The nerve regeneration and orientation of the nerve fibers, as well as the fibrous tissue formation were evaluated. On the short term, nerve regeneration was slightly faster in the non-coated nerve guide. After longer implantation periods (≥ 4 weeks), nerve regeneration in the fibrin-coated nerve guides was characterized by a severe inflammatory response with large numbers of macrophages and polymorphonuclear cells (PMN's). This study clearly demonstrates that nerve regeneration in a fibrin-coated nerve guide is not faster when compared with a non-coated nerve guide, and that nerve regeneration in the fibrin-coated nerve guide is even worse after longer implantation periods.</p

Polymer reptation and nucleosome repositioning

We consider how beads can diffuse along a chain that wraps them, without becoming displaced from the chain; our proposed mechanism is analogous to the reptation of "stored length" in more familiar situations of polymer dynamics. The problem arises in the case of globular aggregates of proteins (histones) that are wound by DNA in the chromosomes of plants and animals; these beads (nucleosomes) are multiply wrapped and yet are able to reposition themselves over long distances, while remaining bound by the DNA chain.Comment: 9 pages, including 2 figures, to be published in Phys. Rev. Let

‘What are you going to do, confiscate their passports?’ Professional perspectives on cross-border reproductive travel

Objective: This article reports findings from a UK-based study which explored the phenomenon of overseas travel for fertility treatment. The first phase of this project aimed to explore how infertility clinicians and others professionally involved in fertility treatment understand the nature and consequences of cross-border reproductive travel. Background: There are indications that, for a variety of reasons, people from the UK are increasingly travelling across national borders to access assisted reproductive technologies. While research with patients is growing, little is known about how ‘fertility tourism’ is perceived by health professionals and others with a close association with infertility patients. Methods: Using an interpretivist approach, this exploratory research included focussed discussions with 20 people professionally knowledgeable about patients who had either been abroad or were considering having treatment outside the UK. Semi-structured interviews were recorded, transcribed verbatim and subjected to a thematic analysis. Results: Three conceptual categories are developed from the data: ‘the autonomous patient’; ‘cross-border travel as risk’, and ‘professional responsibilities in harm minimisation’. Professionals construct nuanced, complex and sometimes contradictory narratives of the ‘fertility traveller’, as vulnerable and knowledgeable; as engaged in risky behaviour and in its active minimisation. Conclusions: There is little support for the suggestion that states should seek to prevent cross-border treatment. Rather, an argument is made for less direct strategies to safeguard patient interests. Further research is required to assess the impact of professional views and actions on patient choices and patient experiences of treatment, before, during and after travelling abroad

Картографический метод в изучении территориального рекреационного неравенства

This article investigates the link between teachers' appraisal of specific interpersonal situations in classrooms and their more general interpersonal identity standard, which together form their interpersonal role identity. Using semi-structured and video-stimulated interviews, data on teachers' appraisals and interpersonal identity standards were collected and analyzed using appraisal and interpersonal circumplex theory. Results show a variety of interpersonal identity standards, although the majority of the teachers mentions standards focusing on the codes steering and being friendly. The situation “reacting to student positive behavior” evoked most appraisals that confirmed identity standards. For 13 of the 29 teachers, their identity standard matched with their appraisals. In most cases, however, this match was only to some extent (10 teachers) and sometimes not at all (six teachers). The results suggest that teachers can enhance their relationship with students by becoming more aware of the meanings teachers attach to this relationship in specific situations

Clinical and Radiologic Predictors of Parastomal Hernia Development After End Colostomy

OBJECTIVE. Parastomal hernia (PSH) is a common complication that can occur after end colostomy and may result in considerable morbidity. To select the best candidates for prophylactic measures, knowledge of preoperative PSH predictors is important. This study aimed to determine the value of clinical parameters, preoperative CT-based body metrics, and size of the abdominal wall defect created during end colostomy and measured at postoperative CT for predicting PSH development. MATERIALS AND METHODS. Sixty-five patients who underwent permanent end colostomy with at least 1 year of follow-up were included. On preoperative CT, waist circumference, abdominal wall and psoas muscle indexes, rectus abdominis muscle diameter and diastasis, intra- and extraabdominal fat mass, and presence of other hernias were assessed. On postoperative CT, size of the abdominal wall defect and the presence of PSH were determined. To identify independent predictors of PSH development, univariate analysis with the Kaplan-Meier method and multivariate Cox regression analysis were performed. RESULTS. PSH developed after surgery in 30 patients (46%). Three independent risk factors were identified: chronic obstructive pulmonary disease (COPD) as a comorbidity (hazard ratio [HR], 6.4; 95% CI, 1.9-22.0; p = 0.003), operation time longer than 395 minutes (HR, 3.9; 95% CI, 1.5-10.0; p = 0.005), and maximum aperture diameter of more than 34 mm (HR, 5.2; 95% CI, 2.1-12.7; p <0.001). PSH developed in all nine patients with a maximum abdominal wall defect diameter of more than 50 mm at the ostomy site. CONCLUSION. COPD, longer operation time, and larger abdominal wall defect at the colostomy site can predict PSH development. Intraoperative creation of an abdominal wall ostomy opening that is more than 34 mm in diameter should be avoided