374 research outputs found
Polarity patterns of stress fibers
Stress fibers are contractile actomyosin bundles commonly observed in the
cytoskeleton of metazoan cells. The spatial profile of the polarity of actin
filaments inside contractile actomyosin bundles is either monotonic (graded) or
periodic (alternating). In the framework of linear irreversible thermodynamics,
we write the constitutive equations for a polar, active, elastic
one-dimensional medium. An analysis of the resulting equations for the dynamics
of polarity shows that the transition from graded to alternating polarity
patterns is a nonequilibrium Lifshitz point. Active contractility is a
necessary condition for the emergence of sarcomeric, alternating polarity
patterns.Comment: 5 pages, 3 figure
Escape configuration lattice near the nematic-isotropic transition: Tilt analogue of blue phases
We predict the possible existence of a new phase of liquid crystals near the
nematic-isotropic () transition. This phase is an achiral, tilt-analogue
of the blue phase and is composed of a lattice of {\em double-tilt},
escape-configuration cylinders. We discuss the structure and the stability of
this phase and provide an estimate of the lattice parameter.Comment: 5 pages, 6 figures (major revision, typos corrected, references
added
Sexually dimorphic role for vasopressin in the development of social play
Despite the well-established role of vasopressin (AVP) in adult social behavior, its role in social development is relatively unexplored. In this paper, we focus on the most prominent social behavior of juvenile rats, social play. Previous pharmacological experiments in our laboratory suggested that AVP regulates play in a sex- and brain region-specific manner in juvenile rats. Here we investigate the role of specific AVP systems in the emergence of social play. We first characterize the development of play in male and female Wistar rats and then ask whether the development of AVP mRNA expression correlates with the emergence of play. Unexpectedly, play emerged more rapidly in weanling-aged females than in males, resulting in a sex difference opposite of that typically reported for older, juvenile rats. AVP mRNA and play were correlated in males only, with a negative correlation in the bed nucleus of the stria terminalis and a positive correlation in the paraventricular nucleus of the hypothalamus. These findings support the hypothesis that AVP acts differentially on multiple systems in a sex-specific manner to regulate social play and suggest a role for PVN and BNST AVP systems in the development of play. Differential neuropeptide regulation of male and female social development may underlie well-documented sex differences in incidence, progression, and symptom severity of behavioral disorders during development
Community mobilisation to prevent violence against women and girls in eastern India through participatory learning and action with women's groups facilitated by accredited social health activists: a before-and-after pilot study
BACKGROUND: Almost one in three married Indian women have ever experienced physical, sexual, or emotional violence from husbands in their lifetime. We aimed to investigate the preliminary effects of community mobilisation through participatory learning and action groups facilitated by Accredited Social Health Activists (ASHAs), coupled with access to counselling, to prevent violence against women and girls in Jharkhand, eastern India. METHODS: We piloted a cycle of 16 participatory learning and action meetings with women's groups facilitated by ASHAs in rural Jharkhand. Participants identified common forms of violence against women and girls, prioritised the ones they wanted to address, developed locally feasible strategies to address them, implemented the strategies, and evaluated the process. We also trained two counsellors and two ASHA supervisors to support survivors, and gave ASHAs information about legal, health, and police services. We did a before-and-after pilot study involving baseline and endline surveys with group members to estimate preliminary effects of these activities on the acceptability of violence, prevalence of past year emotional and physical violence, and help-seeking. RESULTS: ASHAs successfully conducted monthly participatory learning and action meetings with 39 women's groups in 22 villages of West Singhbhum district, Jharkhand, between June 2016 and September 2017. We interviewed 59% (679/1149) of women registered with groups at baseline, and 63% (861/1371) at endline. More women reported that violence was unacceptable in all seven scenarios presented to them at endline compared to baseline (adjusted Odds Ratio [aOR]: 1.87, 95%: 1.39-2.52). Fewer women reported experiencing emotional violence from their husbands in the last 12âmonths (aOR: 0.55, 95% CI: 0.43-0.71), and more sought help if it occurred (aOR: 2.19, 95% CI: 1.51-3.17). In addition, fewer women reported experiencing emotional or physical violence from family members other than their husbands in the last 12âmonths (aOR: 0.41, 95% CI: 0.32-0.53, and aOR: 0.36, 95% CI: 0.26-0.50, respectively). CONCLUSION: Combining participatory learning and action meetings facilitated by ASHAs with access to counselling was an acceptable strategy to address violence against women and girls in rural communities of Jharkhand. The approach warrants further implementation and evaluation as part of a comprehensive response to violence
Tissue factor in antiphospholipid antibody-induced pregnancy loss:a pro-inflammatory molecule
Fetal loss in patients with antiphospholipid antibodies (aPL) has been ascribed to thrombosis of placental vessels. However, we have shown that inflammation, specifically complement activation with generation of the anaphylotoxin C5a, is an essential mediator of fetal injury. We have analysed the role of tissue factor (TF) in a mouse model of aPL-induced pregnancy loss. TF is the major cellular activator of the coagulation cascade but also has cell signaling activity. Mice that received aPL-IgG showed strong TF staining throughout the decidua and on embryonic debris. This TF staining was not associated with either fibrin staining or thrombi in deciduas. The absence of fibrin deposition and thrombi suggests that TF-dependent activation of coagulation does not mediate aPL-induced pregnancy loss. We found that either blockade of TF with a monoclonal antibody in wild type mice or a genetic reduction of TF prevented aPL-induced inflammation and pregnancy loss indicated a pathogenic role for TF in aPL-induced pregnancy complications. In response to aPL-generated C5a, neutrophils express TF potentiating inflammation in the deciduas and leading to miscarriages. Importantly, we showed that TF in myeloid cells, but not fetal-derived cells (trophoblasts), was associated with fetal injury, suggesting that the site for pathologic TF expression is neutrophils. We found that TF expression in neutrophils contributes to respiratory burst and subsequent trophoblast injury and pregnancy loss induced by aPL. The identification of TF, acting as an important pro-inflammatory mediator in aPL-induced fetal injury, provides a new target for therapy to prevent pregnancy loss in the aPL syndrome
Polydispersity and ordered phases in solutions of rodlike macromolecules
We apply density functional theory to study the influence of polydispersity
on the stability of columnar, smectic and solid ordering in the solutions of
rodlike macromolecules. For sufficiently large length polydispersity (standard
deviation ) a direct first-order nematic-columnar transition is
found, while for smaller there is a continuous nematic-smectic and
first-order smectic-columnar transition. For increasing polydispersity the
columnar structure is stabilized with respect to solid perturbations. The
length distribution of macromolecules changes neither at the nematic-smectic
nor at the nematic-columnar transition, but it does change at the
smectic-columnar phase transition. We also study the phase behaviour of binary
mixtures, in which the nematic-smectic transition is again found to be
continuous. Demixing according to rod length in the smectic phase is always
preempted by transitions to solid or columnar ordering.Comment: 13 pages (TeX), 2 Postscript figures uuencode
International Consensus Conference on Atopic Dermatitis II (ICCAD II * ): clinical update and current treatment strategies
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74915/1/j.1365-2133.148.s63.1.x.pd
Integrated multisectoral strategy to improve girls' and women's nutrition before conception, during pregnancy and after birth in India (Swabhimaan): protocol for a prospective, non-randomised controlled evaluation
INTRODUCTION: Swabhimaan is a community-based programme to improve adolescent girlsâ and womenâs nutrition in the rural areas of three Indian statesâBihar, Chhattisgarh and Odisha with high prevalence of undernutrition.
METHODS AND ANALYSIS: Swabhimaan has a nested prospective, non-randomised controlled evaluation. Since 2017, five intervention sites receive community-led interventions through national governmentâs livelihood mission supported womenâs self-help group federations and five control sites will initiate these activities 36 months later, in 2020. Community-led activities aim to improve coverage of 18 interventions including adequacy of food consumed, prevention of micronutrient deficiencies, access to basic health services and special care of nutritionally âat riskâ girls and women, improving hygiene and access to water and sanitation services and access to family planning services. The evaluation includes baseline (2016â2017), midline (2018â2019) and endline (2020â2021) surveys covering 6638 adolescent girls, 2992 pregnant women and 8755 mothers of children under 2. The final impact analysis will be by intention to treat, comparing primary and secondary outcomes in five intervention areas and five control areas. The primary outcomes are: (1) a 15% reduction in the proportion of adolescent girls with a body mass index (BMI) <18.5âkg/m2; (2) a 15% reduction in the proportion of mothers of children under two with a BMI <18.5âkg/m2 and (3) and a 0.4âcm improvement in mean mid-upper arm circumference among pregnant women.
ETHICS AND DISSEMINATION: All procedures involving human subjects were approved by the Institutional Ethics Committee of the All India Institute of Medical Sciences, Bihar, Chhattisgarh and Odisha and in compliance with guidelines laid down in the Declaration of Helsinki. Evidence will inform maternal and preconception nutrition policy at national and state level.
TRIAL REGISTRATION NUMBER: 58261b2f46876 and CTRI/2016/11/007482; Pre-results
Structured reporting of computed tomography in the staging of colon cancer: a Delphi consensus proposal
Background: Structured reporting (SR) in radiology is becoming increasingly necessary and has been recognized recently by major scientific societies. This study aims to build structured CT-based reports in colon cancer during the staging phase in order to improve communication between the radiologist, members of multidisciplinary teams and patients. Materials and methods: A panel of expert radiologists, members of the Italian Society of Medical and Interventional Radiology, was established. A modified Delphi process was used to develop the SR and to assess a level of agreement for all report sections. Cronbachâs alpha (Cα) correlation coefficient was used to assess internal consistency for each section and to measure quality analysis according to the average inter-item correlation. Results: The final SR version was built by including n = 18 items in the âPatient Clinical Dataâ section, n = 7 items in the âClinical Evaluationâ section, n = 9 items in the âImaging Protocolâ section and n = 29 items in the âReportâ section. Overall, 63 items were included in the final version of the SR. Both in the first and second round, all sections received a higher than good rating: a mean value of 4.6 and range 3.6â4.9 in the first round; a mean value of 5.0 and range 4.9â5 in the second round. In the first round, Cronbachâs alpha (Cα) correlation coefficient was a questionable 0.61. In the first round, the overall mean score of the experts and the sum of scores for the structured report were 4.6 (range 1â5) and 1111 (mean value 74.07, STD 4.85), respectively. In the second round, Cronbachâs alpha (Cα) correlation coefficient was an acceptable 0.70. In the second round, the overall mean score of the experts and the sum of score for structured report were 4.9 (range 4â5) and 1108 (mean value 79.14, STD 1.83), respectively. The overall mean score obtained by the experts in the second round was higher than the overall mean score of the first round, with a lower standard deviation value to underline greater agreement among the experts for the structured report reached in this round. Conclusions: A wide implementation of SR is of critical importance in order to offer referring physicians and patients optimum quality of service and to provide researchers with the best quality data in the context of big data exploitation of available clinical data. Implementation is a complex procedure, requiring mature technology to successfully address the multiple challenges of user-friendliness, organization and interoperability
Quantum dynamics in strong fluctuating fields
A large number of multifaceted quantum transport processes in molecular
systems and physical nanosystems can be treated in terms of quantum relaxation
processes which couple to one or several fluctuating environments. A thermal
equilibrium environment can conveniently be modelled by a thermal bath of
harmonic oscillators. An archetype situation provides a two-state dissipative
quantum dynamics, commonly known under the label of a spin-boson dynamics. An
interesting and nontrivial physical situation emerges, however, when the
quantum dynamics evolves far away from thermal equilibrium. This occurs, for
example, when a charge transferring medium possesses nonequilibrium degrees of
freedom, or when a strong time-dependent control field is applied externally.
Accordingly, certain parameters of underlying quantum subsystem acquire
stochastic character. Herein, we review the general theoretical framework which
is based on the method of projector operators, yielding the quantum master
equations for systems that are exposed to strong external fields. This allows
one to investigate on a common basis the influence of nonequilibrium
fluctuations and periodic electrical fields on quantum transport processes.
Most importantly, such strong fluctuating fields induce a whole variety of
nonlinear and nonequilibrium phenomena. A characteristic feature of such
dynamics is the absence of thermal (quantum) detailed balance.Comment: review article, Advances in Physics (2005), in pres
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