Chaos in Symmetric Phase Oscillator Networks

Phase-coupled oscillators serve as paradigmatic models of networks of weakly interacting oscillatory units in physics and biology. The order parameter which quantifies synchronization was so far found to be chaotic only in systems with inhomogeneities. Here we show that even symmetric systems of identical oscillators may not only exhibit chaotic dynamics, but also chaotically fluctuating order parameters. Our findings imply that neither inhomogeneities nor amplitude variations are necessary to obtain chaos, i.e., nonlinear interactions of phases give rise to the necessary instabilities.Comment: 4 pages; Accepted by Physical Review Letter

Temperature dependence of antiferromagnetic order in the Hubbard model

We suggest a method for an approximative solution of the two dimensional Hubbard model close to half filling. It is based on partial bosonisation, supplemented by an investigation of the functional renormalisation group flow. The inclusion of both the fermionic and bosonic fluctuations leads in lowest order to agreement with the Hartree-Fock result or Schwinger-Dyson equation and cures the ambiguity of mean field theory . We compute the temperature dependence of the antiferromagnetic order parameter and the gap below the critical temperature. We argue that the Mermin-Wagner theorem is not practically applicable for the spontaneous breaking of the continuous spin symmetry in the antiferromagnetic state of the Hubbard model. The long distance behavior close to and below the critical temperature is governed by the renormalisation flow for the effective interactions of composite Goldstone bosons and deviates strongly from the Hartree-Fock result.Comment: New section on critical behavior 31 pages,17 figure

Влияние неоднородностей температуры поверхности на теплообмен воздуха с Землей

В работе проведено моделирование процесса натекания воздуха с холодной поверхности воды на теплую поверхность суши и сравнение расчетов с результатами измерений. Из расчетов следует, что потоки тепла в прибрежной зоне могут более чем на 20% превышать значения потоков тепла, вычисленных из предположения о горизонтальной однородности приземного слоя. Таким образом, горизонтальную неоднородность атмосферы следует учитывать при расчетах охлаждения водоемов, горизонтальный размер которых имеет масштаб ~100 м.В роботі проведено моделювання процесу натікання повітря з холодної поверхні води на теплу поверхню суші та порівняння розрахунків із вимірюваннями. З розрахунків видно, що потоки тепла в прибережній зоні можуть більш ніж на 20% перевищувати значення потоків тепла, обчислених з припущення про горизонтальну однорідність приземного шару. Таким чином, горизонтальну неоднорідність атмосфери слід враховувати при розрахунках охолодження водойм, горизонтальний розмір яких має масштаб ~100 м.In the paper, the air flow process from the cold water surface onto the warm land surface was simulated. The comparisons of calculations with measurements were performed as well. The calculations show that the heat flux in the narrow coastal zone may be more than 20% higher than the values of heat fluxes calculated from the assumption of horizontal homogeneity of the surface layer. Thus, the horizontal inhomogeneity of the atmosphere must be taken into account in the calculation of the cooling water, the horizontal size of which has a scale of ~100 m

Human gene copy number spectra analysis in congenital heart malformations

The clinical significance of copy number variants (CNVs) in congenital heart disease (CHD) continues to be a challenge. Although CNVs including genes can confer disease risk, relationships between gene dosage and phenotype are still being defined. Our goal was to perform a quantitative analysis of CNVs involving 100 well-defined CHD risk genes identified through previously published human association studies in subjects with anatomically defined cardiac malformations. A novel analytical approach permitting CNV gene frequency “spectra” to be computed over prespecified regions to determine phenotype-gene dosage relationships was employed. CNVs in subjects with CHD (n = 945), subphenotyped into 40 groups and verified in accordance with the European Paediatric Cardiac Code, were compared with two control groups, a disease-free cohort (n = 2,026) and a population with coronary artery disease (n = 880). Gains (≥200 kb) and losses (≥100 kb) were determined over 100 CHD risk genes and compared using a Barnard exact test. Six subphenotypes showed significant enrichment (P ≤ 0.05), including aortic stenosis (valvar), atrioventricular canal (partial), atrioventricular septal defect with tetralogy of Fallot, subaortic stenosis, tetralogy of Fallot, and truncus arteriosus. Furthermore, CNV gene frequency spectra were enriched (P ≤ 0.05) for losses at: FKBP6, ELN, GTF2IRD1, GATA4, CRKL, TBX1, ATRX, GPC3, BCOR, ZIC3, FLNA and MID1; and gains at: PRKAB2, FMO5, CHD1L, BCL9, ACP6, GJA5, HRAS, GATA6 and RUNX1. Of CHD subjects, 14% had causal chromosomal abnormalities, and 4.3% had likely causal (significantly enriched), large, rare CNVs. CNV frequency spectra combined with precision phenotyping may lead to increased molecular understanding of etiologic pathways

Improving inpatient postnatal services: midwives views and perspectives of engagement in a quality improvement initiative

Background: despite major policy initiatives in the United Kingdom to enhance women's experiences of maternity care, improving in-patient postnatal care remains a low priority, although it is an aspect of care consistently rated as poor by women. As part of a systems and process approach to improving care at one maternity unit in the South of England, the views and perspectives of midwives responsible for implementing change were sought. Methods: a Continuous Quality Improvement (CQI) approach was adopted to support a systems and process change to in-patient care and care on transfer home in a large district general hospital with around 6000 births a year. The CQI approach included an initial assessment to identify where revisions to routine systems and processes were required, developing, implementing and evaluating revisions to the content and documentation of care in hospital and on transfer home, and training workshops for midwives and other maternity staff responsible for implementing changes. To assess midwifery views of the quality improvement process and their engagement with this, questionnaires were sent to those who had participated at the outset. Results: questionnaires were received from 68 (46%) of the estimated 149 midwives eligible to complete the questionnaire. All midwives were aware of the revisions introduced, and two-thirds felt these were more appropriate to meet the women's physical and emotional health, information and support needs. Some midwives considered that the introduction of new maternal postnatal records increased their workload, mainly as a consequence of colleagues not completing documentation as required. Conclusions: this was the first UK study to undertake a review of in-patient postnatal services. Involvement of midwives at the outset was essential to the success of the initiative. Midwives play a lead role in the planning and organisation of in-patient postnatal care and it was important to obtain their feedback on whether revisions were pragmatic and achieved anticipated improvements in care quality. Their initial involvement ensured priority areas for change were identified and implemented. Their subsequent feedback highlighted further important areas to address as part of CQI to ensure best quality care continues to be implemented. Our findings could support other maternity service organisations to optimise in-patient postnatal services

Upright Versus Lying Down Position in Second Stage of Labour in Nulliparous Women With Low Dose Epidural: BUMPES Randomised Controlled Trial

INTERVENTIONS Women were allocated to an upright or lying down position, using a secure web based randomisation service, stratified by centre, with no masking of participants or clinicians to the trial interventions. MAIN OUTCOME MEASURES The primary outcome was spontaneous vaginal birth. Women were analysed in the groups into which they were randomly allocated, regardless of position recorded at any time during the second stage of labour (excluding women with no valid consent, who withdrew, or who did not reach second stage before delivery). Secondary outcomes included mode of birth, perineal trauma, infant Apgar, delivery (adjusted risk ratio 1.08, 99% confidence interval 0.99 to 1.18), obstetric anal sphincter injury (1.27, 0.88 to 1.84), infant Apgar score <4 at five minutes (0.66, 0.06 to 6.88), and maternal faecal incontinence at one year (1.18, 0.61 to 2.28). CONCLUSIONS Evidence shows that lying down in the second stage of labour results in more spontaneous vaginal births in nulliparous women with epidural analgesia, with no apparent disadvantages in relation to short or longer term outcomes for mother or baby

A qualitative study of the experiences and expectations of women receiving in-patient postnatal care in one English maternity unit

Background Studies consistently highlight in-patient postnatal care as the area of maternity care women are least satisfied with. As part of a quality improvement study to promote a continuum of care from the birthing room to discharge home from hospital, we explored women’s expectations and experiences of current inpatient care. Methods For this part of the study, qualitative data from semi-structured interviews were transcribed and analysed using content analyses to identify issues and concepts. Women were recruited from two postnatal wards in one large maternity unit in the South of England, with around 6,000 births a year. Results Twenty women, who had a vaginal or caesarean birth, were interviewed on the postnatal ward. Identified themes included; the impact of the ward environment; the impact of the attitude of staff; quality and level of support for breastfeeding; unmet information needs; and women’s low expectations of hospital based postnatal care. Findings informed revision to the content and planning of in-patient postnatal care, results of which will be reported elsewhere. Conclusions Women’s responses highlighted several areas where changes could be implemented. Staff should be aware that how they inter-act with women could make a difference to care as a positive or negative experience. The lack of support and inconsistent advice on breastfeeding highlights that units need to consider how individual staff communicate information to women. Units need to address how and when information on practical aspects of infant care is provided if women and their partners are to feel confident on the woman’s transfer home from hospital

A psychoanalytic concept illustrated: Will, must, may, can — revisiting the survival function of primitive omnipotence

The author explores the linear thread connecting the theory of Freud and Klein, in terms of the central significance of the duality of the life and death instinct and the capacity of the ego to tolerate contact with internal and external reality. Theoretical questions raised by later authors, informed by clinical work with children who have suffered deprivation and trauma in infancy, are then considered. Theoretical ideas are illustrated with reference to observational material of a little boy who suffered deprivation and trauma in infancy. He was first observed in the middle of his first year of life while he was living in foster care, and then later at the age of two years and three months, when he had been living with his adoptive parents for more than a year

The effect of corporate governance on the performance of US investment banks

This paper focuses on the impact of the corporate governance, using a plethora of measures, on the performance of the US investment banks over the 2000-2012 period. This time period offers a unique set of information, related to the credit crunch, that we model using a dynamic panel threshold analysis to reveal new insights into the relationship between corporate governance and bank performance. Results show that the board size asserts a negative effect on performance consistent with the ‘agency cost’ hypothesis, particularly for banks with board size higher than ten members. Threshold analysis reveals that in the post-crisis period most of investment banks opt for boards with less than ten members, aiming to decrease agency conflicts that large boards suffer from. We also find a negative association between the operational complexity and performance. Moreover, the CEO power asserts a positive effect on performance consistent with the ‘stewardship’ hypothesis. In addition, an increase in the bank ownership held by the board has a negative impact on performance for banks below a certain threshold. On the other hand, for banks with board ownership above the threshold value this effect turns positive, indicating an alignment between shareholders’ and managers’ incentives

Search for Solar Axions Produced in p(d,3He)Ap(d,\rm{^3He})A Reaction with Borexino Detector

A search for 5.5-MeV solar axions produced in the $p+d\rightarrow\rm{^3He}+A (5.5 \rm{MeV})$ reaction was performed using the Borexino detector. The Compton conversion of axions to photons, ${\rm A}+e\rightarrow e+\gamma$; the axio-electric effect, ${\rm A}+e+Z\rightarrow e+Z$; the decay of axions into two photons, ${\rm A}\rightarrow2\gamma$; and inverse Primakoff conversion on nuclei, ${\rm A}+Z\rightarrow\gamma+Z$, are considered. Model independent limits on axion-electron ($g_{Ae}$), axion-photon ($g_{A\gamma}$), and isovector axion-nucleon ($g_{3AN}$) couplings are obtained: $|g_{Ae}\times g_{3AN}| \leq 5.5\times 10^{-13}$ and $|g_{A\gamma}\times g_{3AN}| \leq 4.6\times 10^{-11} \rm{GeV}^{-1}$ at $m_A <$ 1 MeV (90% c.l.). These limits are 2-4 orders of magnitude stronger than those obtained in previous laboratory-based experiments using nuclear reactors and accelerators.Comment: 11 pages, 7 figures, submitted to Phys.Rev.