Haze in the Klang Valley of Malaysia

Continuous measurements of dry aerosol light scattering (Bsp) were made at two sites in the Klang Valley of Malaysia between December 1998 and December 2000. In addition 24-h PM2.5 samples were collected on a one-day-in-six cycle and the chemical composition of the aerosol was determined. Periods of excessive haze were defined as 24-h average Bsp values greater than 150 Mm-1 and these occurred on a number of occasions, between May and September 1999, during May 2000, and between July and September 2000. The evidence for smoke being a significant contributor to aerosol during periods of excessive haze is discussed and includes features of the aerosol chemistry, the diurnal cycle of Bsp, and the coincidence of forest fires on Sumatra during the southwest (SW) monsoon period, as well as transport modelling for one week of the southwest Monsoon of 2000. The study highlights that whilst transboundary smoke is a major contributor to poor visibility in the Klang Valley, smoke from fires on Peninsular Malaysia is also a contributor, and at all times, the domestic source of secondary particle production is present

The unique chemistry of Eastern Mediterranean water masses selects for distinct microbial communities by depth

Peer reviewedPublisher PD

Factors associated with postpartum depressive symptomatology in Brazil: The Birth in Brazil National Research Study, 2011/2012

Background: Depression is one of the most common postpartum mental disorders. Many sociodemographic and individuals risk factors are associated with maternal depression but the impact of high levels of birth intervention is unclear. The Brazilian context is characterized by excessive intervention and frequent non-compliance with recommended obstetric protocols. This study therefore examined the impact of sociodemographic, individual, and obstetric risk factors in postpartum depression. Methods: The Birth in Brazil research study is a national study of 23,894 postpartum women. Information about depression was obtained by telephone interview at 6 to 18 months after birth and was measured using the Edinburgh Postnatal Depression Scale. Results: The prevalence of probable cases of depression was 26.3%. A multivariate model identified significant sociodemographic and individual risk factors as: brown skin color (OR = 1.15 CI 1.01-1.31), lower economic class (OR=1.70 CI 1.41-2.06), alcohol use (OR= 1.41 CI 1.09-1.84) and a history of mental disorders (OR= 3.13 CI 1.80-5.44). Significant obstetric factors were unplanned pregnancy (OR=1.22 CI 1.05-1.43 for wanted later and OR= 1.38 CI 1.20-1.60 for never wanted), multiparity (OR=1.97 CI 1.58-2.47 for 3 or more children), and poor care during birth (OR= 2.02 CI 1.28-3.20) or of the newborn (OR=2.16 CI 1.51-3.10). Obstetric interventions and complications were not associated with maternal depression. Limitations: Depression was measured only once so we are not able to examine the course over time. The associational and reverse causality cannot be ruled out for some variables. Conclusions: The prevalence of postpartum depression is high in Brazilian women six months after birth. Poor care of women and babies during birth is more important in postpartum depression than physical obstetric or neonatal intervention and complications

Quasiparticle properties in a density functional framework

We propose a framework to construct the ground-state energy and density matrix of an N-electron system by solving selfconsistently a set of single-particle equations. The method can be viewed as a non-trivial extension of the Kohn-Sham scheme (which is embedded as a special case). It is based on separating the Green's function into a quasi-particle part and a background part, and expressing only the background part as a functional of the density matrix. The calculated single-particle energies and wave functions have a clear physical interpretation as quasiparticle energies and orbitals.Comment: 12 pages, 1 figure, to be published in Phys. Rev.

Decision-making regarding place of birth in high-risk pregnancy: a qualitative study

Introduction: Women consider factors including safety and the psychological impact of their chosen location when deciding whether to give birth in hospital or at home. The same is true for women with high-risk pregnancies who may plan homebirths against medical advice. This study investigated women’s decision-making during high-risk pregnancies. Half the participants were planning hospital births and half were planning homebirths. Methods: A qualitative study using semi-structured interviews set in a hospital maternity department in the UK. Twenty-six participants with high-risk pregnancies, at least 32 weeks pregnant. Results were analysed using systematic thematic analysis. Results: Three themes emerged: perceptions of birth at home and hospital; beliefs about how birth should be; and the decision process. Both groups were concerned about safety but they expressed different concerns. Women drew psychological comfort from their chosen birth location. Women planning homebirths displayed faith in the natural birth process and stressed the quality of the birth experience. Women planning hospital births believed the access to medical care outweighed their misgivings about the physical environment. Discussion: Although women from both groups expressed similar concerns about safety they reached different decisions about how these should be addressed regarding birth location. These differences may be related to beliefs about the birth process. Commitment to their decisions may have helped reduce cognitive stress

Modeling Supply Networks and Business Cycles as Unstable Transport Phenomena

Physical concepts developed to describe instabilities in traffic flows can be generalized in a way that allows one to understand the well-known instability of supply chains (the so-called ``bullwhip effect''). That is, small variations in the consumption rate can cause large variations in the production rate of companies generating the requested product. Interestingly, the resulting oscillations have characteristic frequencies which are considerably lower than the variations in the consumption rate. This suggests that instabilities of supply chains may be the reason for the existence of business cycles. At the same time, we establish some link to queuing theory and between micro- and macroeconomics.Comment: For related work see http://www.helbing.or

Avatars of Eurocentrism in the critique of the liberal peace

Recent scholarly critiques of the so-called liberal peace raise important political and ethical challenges to practices of postwar intervention in the global South. However, their conceptual and analytic approaches have tended to reproduce rather than challenge the intellectual Eurocentrism underpinning the liberal peace. Eurocentric features of the critiques include the methodological bypassing of target subjects in research, the analytic bypassing of subjects through frameworks of governmentality, the assumed ontological split between the ‘liberal’ and the ‘local’, and a nostalgia for the liberal subject and the liberal social contract as alternative bases for politics. These collectively produce a ‘paradox of liberalism’ that sees the liberal peace as oppressive but also the only true source of emancipation. However, the article suggests that a repoliticization of colonial difference offers an alternative ‘decolonizing’ approach to critical analysis through repositioning the analytic gaze. Three alternative research strategies for critical analysis are briefly developed

Providing immediate neonatal care and resuscitation at birth beside the mother: parents' views, a qualitative study

Objectives: The aims of this study were to assess parents’ views of immediate neonatal care and resuscitation at birth being provided beside the mother, and their experiences of a mobile trolley designed to facilitate this bedside care. Design: Qualitative study with semistructured interviews. Results were analysed using thematic analysis. Setting: Large UK maternity hospital. Participants: Mothers whose baby received initial neonatal care in the first few minutes of life at the bedside, and their birth partners, were eligible. 30 participants were interviewed (19 mothers, 10 partners and 1 grandmother). 5 babies required advanced neonatal resuscitation. Results: 5 themes were identified: (1) Reassurance, which included ‘Baby is OK’, ‘Having baby close’, ‘Confidence in care’, ‘Knowing what's going on’ and ‘Dad as informant’; (2) Involvement of the family, which included ‘Opportunity for contact’, ‘Family involvement’ and ‘Normality’; (3) Staff communication, which included ‘Communication’ and ‘Experience’; (4) Reservations, which included ‘Reservations about witnessing resuscitation’, ‘Negative emotions’ and ‘Worries about the impact on staff’ and (5) Experiences of the trolley, which included ‘Practical issues’ and ‘Comparisons with standard resuscitation equipment’. Conclusions: Families were positive about neonatal care being provided at the bedside, and felt it gave reassurance about their baby's health and care. They also reported feeling involved as a family. Some parents reported experiencing negative emotions as a result of witnessing resuscitation of their baby. Parents were positive about the trolley

The Physicist's Guide to the Orchestra

An experimental study of strings, woodwinds (organ pipe, flute, clarinet, saxophone and recorder), and the voice was undertaken to illustrate the basic principles of sound production in music instruments. The setup used is simple and consists of common laboratory equipment. Although the canonical examples (standing wave on a string, in an open and closed pipe) are easily reproduced, they fail to explain the majority of the measurements. The reasons for these deviations are outlined and discussed.Comment: 11 pages, 10 figures (jpg files). Submitted to European Journal of Physic

Performance of Shannon-entropy compacted N-electron wave functions for configuration interaction methods

The coefficients of full configuration interaction wave functions (FCI) for N-electron systems expanded in N-electron Slater determinants depend on the orthonormal one-particle basis chosen although the total energy remains invariant. Some bases result in more compact wave functions, i.e. result in fewer determinants with significant expansion coefficients. In this work, the Shannon entropy, as a measure of information content, is evaluated for such wave functions to examine whether there is a relationship between the FCI Shannon entropy of a given basis and the performance of that basis in truncated CI approaches. The results obtained for a set of randomly picked bases are compared to those obtained using the traditional canonical molecular orbitals, natural orbitals, seniority minimising orbitals and a basis that derives from direct minimisation of the Shannon entropy. FCI calculations for selected atomic and molecular systems clearly reflect the influence of the chosen basis. However, it is found that there is no direct relationship between the entropy computed for each basis and truncated CI energies.Fil: Alcoba, Diego Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Torre, Alicia. Universidad de Buenos Aires; Argentina. Universidad de Buenos Aires; ArgentinaFil: Lain, Luis. Universidad del País Vasco; España. Universidad del País Vasco; EspañaFil: Massaccesi, Gustavo Ernesto. Universidad del País Vasco; España. Universidad del País Vasco; EspañaFil: Oña, Ofelia Beatriz. Universidad de Buenos Aires; Argentina. Universidad de Buenos Aires; ArgentinaFil: Ayers, P. W.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Van Raemdonck, M.. Mcmaster University; Canadá. Mcmaster University; CanadáFil: Bultinck, P.. University of Ghent; Bélgica. University of Ghent; BélgicaFil: Van Neck, D.. University of Ghent; Bélgica. University of Ghent; Bélgic