Structural Origins of Chiral Second-Order Optical Nonlinearity in Collagen: Amide I Band

AbstractThe molecular basis of nonlinear optical (NLO) chiral effects in the amide I region of type I collagen was investigated using sum-frequency generation vibrational spectroscopy; chiral and achiral tensor elements were separated using different input/output beam polarization conditions. Spectra were obtained from native rat tail tendon (RTT) collagen and from cholesteric liquid crystal-like (LC) type I collagen films. Although RTT and LC collagen both possess long-range order, LC collagen lacks the complex hierarchical organization of RTT collagen. Their spectra were compared to assess the role of such organization in NLO chirality. No significant differences were observed between RTT and LC with respect to chiral or achiral spectra. These findings suggest that amide I NLO chiral effects in type I collagen assemblies arise predominantly from the chiral organization of amide chromophores within individual collagen molecules, rather than from supramolecular structures. The study suggests that sum-frequency generation vibrational spectroscopy may be uniquely valuable in exploring fundamental aspects of chiral nonlinearity in complex macromolecular structures

Technologies of birth and models of midwifery care

This article is based on a study of a reform in the organisation of maternity services in the United Kingdom, which aimed towards developing a more woman-centred model of care. After decades of fragmentation and depersonalisation of care, associated with the shift of birth to a hospital setting, pressure by midwives and mothers prompted government review and a relatively radical turnaround in policy. However, the emergent model of care has been profoundly influenced by concepts and technologies of monitoring. The use of such technologies as ultrasound scans, electronic foetal monitoring and oxytocic augmentation of labour, generally supported by epidural anaesthesia for pain relief, have accompanied the development of a particular ecological model of birth – often called active management –, which is oriented towards the idea of an obstetric norm. Drawing on analysis of women’s narrative accounts of labour and birth, this article discusses the impact on women’s embodiment in birth, and the sources of information they use about the status of their own bodies, their labour and that of the child. It also illustrates how the impact on women’s experiences of birth may be mediated by a relational model of support, through the provision of caseload midwifery care

Low temperature structural phase transition and incommensurate lattice modulation in the spin gap compound BaCuSi2O6

Results of high resolution x-ray diffraction experiments are presented for single crystals of the spin gap compound BaCuSi$_2$O$_6$ in the temperature range from 16 to 300 K. The data show clear evidence of a transition from the room temperature tetragonal phase into an incommensurately modulated orthorhombic structure below $\sim$100 K. This lattice modulation is characterized by a resolution limited wave vector {\bf q}$_{IC}$=(0,$\sim$0.13,0) and its 2$^{nd}$ and 3$^{rd}$ harmonics. The phase transition is first order and exhibits considerable hysteresis. This observation implies that the spin Hamiltonian representing the system is more complex than originally thought.Comment: 4 pages, 4 figure

Obstetric care models in the Southern Region of Brazil and associated factors

The study sought to identify obstetric care models for low-risk pregnancies in the Southern Region of Brazil and to estimate factors associated with these models and maternal and neonatal outcomes. This is a cross-sectional, hospital-based study using data from the Birth in Brazil survey regarding puerperae and newborns. We identified 2,668 low-risk pregnant women. We carried out an exploratory analysis using the proportion of practices per hospital, among them inducing labor, presence of a companion, cesarean section and skin-to-skin contact, in order to obtain the care models we called Best Practice, Interventionist I and Interventionist II. We then carried out an inferential analysis of the associated characteristics. Results show that access to public or private funding, cultural factors and actions taken by health professional are associated with the care models. Public care had different contexts, one based on public policies and evidence-based practices; and another, that suggests the intentionality of vaginal delivery without considering humanization principles. Private care, on the other hand, is standardized and centered on the medical professional, with higher intervention levels. We conclude there is a predominance of interventionist obstetric care models in the Southern Region of Brazil, a type of care that goes against the best evidence, and that women who receive care in public hospitals have greater chances of benefiting from good practices

Prevalence of spontaneous, induced labour or planned caesarean section and factors associated with caesarean scetion and factors associated with caesarian section in low-risk women in southern Brazil

Objective This study aimed to examine the prevalence of spontaneous labour, induced labour and planned caesarean section in low-risk women; to identify the contribution of each group to the overall caesarean section rate; and to estimate factors associated with caesarean section in low-risk women according to spontaneous labour, induced labour and planned caesarean section. Design Cross-sectional hospital-based study of postpartum women and newborns, using data from the survey Birth in Brazil, Southern region. In the sample of 2,668 low-risk women, a descriptive analysis was undertaken and a Multinomial Logistic Regression model was applied to verify associations among caesarean section and spontaneous labour, induced labour and planned caesarean section in comparison with vaginal birth. Measurements and Findings The results showed the prevalence of spontaneous labour (48.0%), induced labour (14.0%) and planned caesarean sections (38.0%); these frequencies contributed to an overall caesarean section rate of 50.5%. Obstetric characteristics like previous vaginal birth or previous caesarean section were differentially associated with caesarean section, independently of the labour. Caesarean section without labour was significantly associated with age ≥ 35 years (ORadj 5.45 95%CI 3.16-9.39), economic class A and B (ORadj 3.10 95%CI 1.92-4.99), pregnancy between 37 and 38 weeks (ORadj 1.65 95%CI 1.22-2.24), same obstetrician in prenatal and childbirth (ORadj 13.83 95%CI 8.85-21.61) and private payment source at birth (ORadj 11.50 95%CI 6.64-19.93). Key conclusion For low-risk women in Southern Brazil, the results identify high planned caesarean section rates, not associated with socioeconomic, obstetric, institutional or prenatal factors that justify these rates

AXL modulates extracellular matrix protein expression and is essential for invasion and metastasis in endometrial cancer

The receptor tyrosine kinase AXL promotes migration, invasion, and metastasis. Here, we evaluated the role of AXL in endometrial cancer. High immunohistochemical expression of AXL was found in 76% (63/83) of advanced-stage, and 77% (82/107) of high-grade specimens and correlated with worse survival in uterine serous cancer patients. In vitro, genetic silencing of AXL inhibited migration and invasion but had no effect on proliferation of ARK1 endometrial cancer cells. AXL-deficient cells showed significantly decreased expression of phospho-AKT as well as uPA, MMP-1, MMP-2, MMP-3, and MMP-9. In a xenograft model of human uterine serous carcinoma with AXL-deficient ARK1 cells, there was significantly less tumor burden than xenografts with control ARK1 cells. Together, these findings underscore the therapeutic potentials of AXL as a candidate target for treatment of metastatic endometrial cancer

Team Composition Revisited: A Team Member Attribute Alignment Approach

Research methods for studying team composition tend to employ either a variable-centered or person-centered approach. The variable-centered approach allows scholars to consider how patterns of attributes between team members influence teams, while the person-centered approach allows scholars to consider how variation in multiple attributes within team members influences subgroup formation and its effects. Team composition theory, however, is becoming increasingly sophisticated, assuming variation on multiple attributes both within and between team members—for example, in predicting how a team functions differently when its most assertive members are also optimistic rather than pessimistic. To support this new theory, we propose an attribute alignment approach, which complements the variable-centered and person-centered approaches by modeling teams as matrices of their members and their members’ attributes. We first demonstrate how to calculate attribute alignment by determining the vector norm and vector angle between team members’ attributes. Then, we demonstrate how the alignment of team member personality attributes (neuroticism and agreeableness) affects team relationship conflict. Finally, we discuss the potential of using the attribute alignment approach to enrich broader team research