Wall-Crossings in Toric Gromov-Witten Theory I: Crepant Examples

Let X be a Gorenstein orbifold and let Y be a crepant resolution of X. We state a conjecture relating the genus-zero Gromov--Witten invariants of X to those of Y, which differs in general from the Crepant Resolution Conjectures of Ruan and Bryan--Graber, and prove our conjecture when X = P(1,1,2) and X = P(1,1,1,3). As a consequence, we see that the original form of the Bryan--Graber Conjecture holds for P(1,1,2) but is probably false for P(1,1,1,3). Our methods are based on mirror symmetry for toric orbifolds.Comment: 71 pages, v2: typos corrected and references modified, v3: corrected errors in Proposition 2.9 and in Summary, v4: major revision, exposition unified from a viewpoint of VSHS, many signpostings for the logical structure; the authorship has changed, with Alessio Corti withdrawin

Assessment of perinatal mental health problems

Mental health problems in pregnancy and the postnatal period can have long-term negative effects on women and their children. A key barrier to helping women in this period is the low level of identification of mental health problems. Depression has commonly been screened for using the Whooley Questions or Edinburgh Postnatal Depression Scale (EPDS) but women may experience a broad range of symptoms of distress not captured by these measures. The research reported in this dissertation was designed to address several aims. The first strand aimed to explore women’s experiences of postnatal mental health problems and how they conceptualise their symptoms. The focus of the first qualitative study was the lived experience of 17 women who had experienced psychological distress in the first postnatal year, and used interpretative phenomenological analysis. The second qualitative study used thematic analysis with the same sample to explore different symptoms of distress and women’s experiences of being assessed for these. The second strand reviewed and evaluated currently existing measures of commonly reported affective symptoms with a view to informing future assessment. A systematic review found a lack of measures of anxiety designed for or validated sufficiently with perinatal women. Factor analyses of the EPDS then explored the structure of depression and anxiety symptoms in the perinatal period in the Avon Longitudinal Study of Parents and Children (N = 11,195 – 12,166). Results suggested symptom clusters of anhedonia, depression and anxiety. Finally, validity of the CORE-10, a short measure of psychological distress was evaluated in a sample of 366 pregnant women. The CORE-10 showed promising psychometric properties. Anxiety was the most reported symptom. Overall findings suggest that perinatal women need to be assessed for a variety of mental health problems and that further work is needed to identify the most effective assessment tool and process

Not identifying with postnatal depression: A qualitative study of womens postnatal symptoms of distress and need for support

Introduction: Diagnoses and symptoms of postnatal mental health problems are associated with adverse outcomes for women and their families. Current classification and assessment of postnatal mental health problems may not adequately address the range or combination of emotional distress experienced by mothers. This study aims to explore symptoms of mental health problems reported by new mothers and their experiences of being assessed for these.Methods: In-depth interviews with 17 women in southeast England with a baby under 1-year old who experienced a postnatal mental health problem. Data were analyzed using inductive thematic analysis.Results: Women described a lack of identification with the concept of postnatal depression and felt that other forms of emotional distress were not recognized by the healthcare system. Women felt that support seeking for postnatal mental health problems needed to be normalized and that support should be available whether or not women were diagnosed. Assessment needs to be well timed and caringly implemented.Discussion: Identification and recognition of symptoms and disorders other than postnatal depression need to be improved. Awareness of multiple types of distress needs to be raised both for women experiencing such distress, and for healthcare professionals, to enable them to support women at this time. Different approaches to assessment that include the range of symptoms reported should be piloted

A multi-method evaluation of interprofessional education for healthcare professionals caring for women during and after pregnancy

This multi-method evaluation assessed the perceived impact of interprofessional workshops targeting enhanced collaboration between healthcare professionals who care for women during and after pregnancy. Current policy recommends partnership working to improve care for women and babies, however, there is little interprofessional education in this area. Five one-day workshops were delivered to 18 healthcare professionals (47.4% of the 38 healthcare professionals registered). The workshop was evaluated through questionnaires before and after the workshop measuring attitudes and willingness towards collaboration; observations of the workshops by a researcher and follow-up interviews 2 months' post-workshop to explore changes in practice. Workshops were attended by midwives, health visitors (trained nurses specialising in community care for children 0-5 years), dietitians, nurses, a general practitioner and a breastfeeding specialist. Attitudes and willingness to participate in interprofessional collaborative practice improved after the workshop. Observations made at the workshop included engaged participants who reported numerous barriers towards collaboration. Follow-up contact with 12 participants identified several examples of collaboration in practice resulting from workshop attendance. These findings suggest that the workshops influenced attendees to change their practice towards more collaborative working. Future work needs to confirm these results with more participants

Multiple shape memory behavior of highly oriented long‐chain‐branched poly(lactic acid) and its recovery mechanism

YesThe shape memory effect of highly oriented long‐chain‐branched poly(lactic acid) (LCB‐PLA) prepared through solid‐phase die drawing technology was studied by comparison with PLA. When the recovery temperature increased from 60°C to 120°C, for PLA, only one‐step recovery at about 80°C can be observed and the recovery ratio was below 21.5%, while, for LCB‐PLA, multiple recovery behavior with high recovery ratio of 78.8% can be achieved. For oriented PLA, the recovery curve of the final sample showed the same trend with that of sample suffering just free drawing; while for oriented LCB‐PLA, the recovery curve of the final sample showed the same trend with that of sample suffering just die drawing. After shape recovery, the mechanical properties of LCB‐PLA showed a linear downward trend with the recovery temperature. Together with amorphous phase, the oriented mesomorphic phase, which formed during solid die drawing, can act as switching domains. And thus, upon heating, the chain segment of amorphous phase relaxed at first and triggered the first macroscopical shape recovery, leading to the decrease of long period (Lac) and the thickness of the amorphous layer (La). Then, with further increasing temperature, the oriented mesomorphic phase gradually relaxed resulting subsequently multi‐shape recovery, and the Lac and the La further decreased. Therefore, by regulating the recovery temperature of oriented LCB‐PLA, the shape recovery ratio and mechanical strength can be controlled effectively, and thus the self‐reinforced and self‐fastening effect can be achieved simultaneously for PLA as bone fixation material

On the Crepant Resolution Conjecture in the Local Case

In this paper we analyze four examples of birational transformations between local Calabi-Yau 3-folds: two crepant resolutions, a crepant partial resolution, and a flop. We study the effect of these transformations on genus-zero Gromov-Witten invariants, proving the Coates-Corti-Iritani-Tseng/Ruan form of the Crepant Resolution Conjecture in each case. Our results suggest that this form of the Crepant Resolution Conjecture may also hold for more general crepant birational transformations. They also suggest that Ruan's original Crepant Resolution Conjecture should be modified, by including appropriate "quantum corrections", and that there is no straightforward generalization of either Ruan's original Conjecture or the Cohomological Crepant Resolution Conjecture to the case of crepant partial resolutions. Our methods are based on mirror symmetry for toric orbifolds.Comment: 27 pages. This is a substantially revised and shortened version of my preprint "Wall-Crossings in Toric Gromov-Witten Theory II: Local Examples"; all results contained here are also proved there. To appear in Communications in Mathematical Physic

The interaction of class and gender in illness narratives

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2008 BSA Publications Ltd.Perspectives on gender and identity that emphasize variability of performance, local context and individual agency have displaced earlier paradigms.These are now perceived to have supported gender stereotypes and language ideologies by emphasizing gender difference and homogeneity within genders. In a secondary analysis of health and illness narratives we explore the interaction of class and gender in individuals' constructions of gendered identity. High social class men perform gender in particularly varied ways and we speculate that this variable repertoire, including the use of what was once termed `women's language', is linked to a capacity to maintain social distinction and authority. Men's performance of conventional masculinity is often threatened by both the experience of illness and being interviewed about personal experience. Lower social class women in particular demonstrate an intensification of a pre-existing informal family and support group culture, marking successful members by awarding them the accolade of being `lovely'.ESR

Structure and blood compatibility of highly oriented poly(l-lactic acid) chain extended by ethylene glycol diglycidyl ether

YesHighly-oriented poly(l-lactic acid) (PLLA) with fibrillar structure and micro-grooves was fabricated through solid hot drawing technology for further improving the mechanical properties and blood biocompatibility of PLLA as blood-contacting medical devices. In order to enhance the melt strength and thus obtain high orientation degree, PLLA was first chain extended with ethylene glycol diglycidyl ether (EGDE). The extending degree as high as 25.79 mol% can be obtained at 0.7 wt% EGDE content. The complex viscosity, storage and viscous modulus for chain extended PLLA were improved resulting from the enhancement of molecular entanglement, and consequently higher draw ratio can be achieved during the subsequent hot stretching. The tensile strength and modulus of PLLA were improved dramatically by stretching. The stress-induced crystallization of PLLA occurred during drawing. The interfacial tension (γs·blood) between PLLA surface and blood decreased by chain extension and molecular orientation, indicating the weakened interaction between bioactive substance in the blood and the surface of PLLA. Modification and orientation could significantly enhance the blood compatibility of PLLA by prolonging clotting time and decreasing hemolysis ratio, protein adsorption and platelet activation. The bionic character of oriented PLLA and its anti-coagulation mechanism were tried to be explored.This research was supported by National Natural Science Foundation of China (Grant No. 51303109

Structure and blood compatibility of highly oriented PLA/MWNTs composites produced by solid hot drawing

YesHighly oriented poly(lactic acid) (PLA)/multi-walled carbon nanotubes (MWNTs) composites were fabricated through solid hot drawing technology in an effort to improve the mechanical properties and blood biocompatibility of PLA as blood-contacting medical devices. It was found that proper MWNTs content and drawing orientation can improve the tensile strength and modulus of PLA dramatically. With the increase in draw ratio, the cold crystallization peak became smaller, and the glass transition and the melting peak of PLA moved to high temperature, while the crystallinity increased, and the grain size decreased, indicating the stress-induced crystallization of PLA during drawing. MWNTs showed a nucleation effect on PLA, leading to the rise in the melting temperature, increase in crystallinity and reduction of spherulite size for the composites. Moreover, the intensity of (002) diffraction of MWNTs increased with draw ratio, indicating that MWNTs were preferentially aligned and oriented during drawing. Microstructure observation demonstrated that PLA matrix had an ordered fibrillar bundle structure, and MWNTs in the composite tended to align parallel to the drawing direction. In addition, the dispersion of MWNTs in PLA was also improved by orientation. Introduction of MWNTs and drawing orientation could significantly enhance the blood compatibility of PLA by prolonging kinetic clotting time, reducing hemolysis ratio and platelet activation

Psychology students’ perception of and engagement with feedback as a function of year of study

Undergraduate students’ perception of feedback and level of engagement with the feedback they receive have gained increasing attention in the educational literature recently to identify areas which require educators’ attention. However, research in this area has generally been based on limited self-selecting samples, and has not considered how students’ relationship with feedback may alter depending on their year of study. To address this, a survey measuring students’ views and practices regarding feedback was completed at a higher education institution by 447 first-, second- and third-year psychology students, representing 77% of the cohort. Findings revealed that third years responded more negatively in both areas than their first- and second-year counterparts, whose ratings on these aspects themselves were far from optimal. These findings highlight the need for early interventions to improve students’ perception of and engagement with feedback in the earlier years, and to prevent the recorded deterioration later on in the degree course