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

Complete Atrioventricular Heart Block From an Epilepsy Treatment

Atrioventricular (AV) heart block without adequate escape rhythm can result in sudden cardiac arrest and death. We report complete (third degree) AV block in a 16 year-old boy as a late effect of vagus nerve stimulation (VNS). He experienced brief, daily, complex partial seizures, treated with lamotrigine, levetiracetam, and the placement of Model 102 VNS at age 4. Electroencephalography (EEG) showed generalized slow spike-and-wave discharges consistent with Lennox-Gastaut syndrome. At age 12, his VNS was changed to Model 303 PereniaDURA/Model 103 Demipulse generator, set at an output current of 2.25 mA on a standard 30 seconds on, 5 minutes off paradigm. At age 16, he experienced episodes of sudden collapse followed by unconsciousness. Holter monitor showed 15 second symptomatic complete AV block without escape (Figure 1). The patient was taking psychotropic medication with potential cardiac side effects: methylphenidate (tachycardia), guanfacine (first degree AV block), and haloperidol (prolonged QT interval, Torsades de Pointes). Haloperidol, methylphenidate, and VNS were stopped without further symptoms. Off these medications, the VNS was resumed at reduced current (1.25 mA), with re-occurrence of symptomatic AV block. Again, the VNS was stopped and symptoms/heart block ceased. Psychotropic medication was resumed without any side effects

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.

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

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

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

Vancomycin-bearing Synthetic Bone Graft Delivers rhBMP-2 and Promotes Healing of Critical Rat Femoral Segmental Defects

For graft-assisted repair of large volumetric bone loss resulting from traumatic orthopedic injuries, strategies that simultaneously promote osteointegration/graft healing and mitigate risks for infections are highly desired. Previously, we developed a poly(2-hydroxyethyl methacrylate)-nanocrystalline hydroxyapatite (pHEMA-nHA) composite as a synthetic bone graft. The composite, when loaded with a single dose of 400-ng rhBMP-2/7 and press-fit into a 5-mm rat femoral segmental defect, led to bony callus fully bridging over the defect and substantial restoration of the torsional rigidity by 12 weeks. More recently, we showed that 4.8 wt% vancomycin can be encapsulated within the composite without compromising the structural and mechanical integrity. Additionally, FDA-approved rhBMP-2 can be absorbed onto the graft and both the vancomycin and rhBMP-2 can be released in a localized and sustained manner. Here we examine the efficacy of pHEMA-nHA-vancomycin grafts pre-absorbed with rhBMP-2 in repairing 5-mm rat femoral segmental defects, and determine if vancomycin hinders the repair. pHEMA-nHA-vancomycin or pHEMA-nHA with/without 3-µg rhBMP-2 were press-fit in 5-mm femoral defects in male rats. Histology, microcomputed tomography, and torsion testing were performed on 12-week explants to evaluate the extent and quality of repair. Partial bridging of the defect with bony callus by 12 weeks was observed with pHEMA-nHA-vancomycin without rhBMP-2 while full bridging with substantially mineralized callus and partial restoration of torsional strength was achieved with 3-µg rhBMP-2. The presence of vancomycin did not significantly compromise graft healing. The pHEMA-nHA-vancomycin graft, with the ability to deliver safe doses of osteogenic recombinant proteins and to simultaneously release the encapsulated antibiotics in a sustained manner holds promise in improving the clinical outcome of graft-assisted repair of traumatic bone injuries

Effects of Microgravity on the Formation of Aerogels

This paper describes research to investigate fundamental aspects of the effects of microgravity on the formation of the microstructure of metal oxide alcogels and aerogels. We are studying the role of gravity on pore structure and gel uniformity in collaboration with Marshall Space Flight Center (MSFC) on gelling systems under microgravity conditions. While this project was just initiated in May 1998, related research performed earlier is described along with the plans and rationale for the current microgravity investigation to provide background and describe newly developing techniques that should be useful for the current gellation studies. The role of gravity in materials processing must be investigated through the study of well-mastered systems. Sol-gel processed materials are near-perfect candidates to determine the effect of gravity on the formation and growth of random clusters from hierarchies of aggregated units. The processes of hydrolysis, condensation, aggregation and gellation in the formation of alcogels are affected by gravity and therefore provide a rich system to study under microgravity conditions. Supercritical drying of the otherwise unstable wet alcogel preserves the alcogel structure produced during sol-gel processing as aerogel. Supercritically dried aerogel provides for the study of material microstructures without interference from the effects of surface tension, evaporation, and solvent flow. Aerogels are microstructured, low density open-pore solids. They have many unusual properties including: transparency, excellent thermal resistance, high surface area, very low refractive index, a dielectric constant approaching that of air, and extremely low sound velocity. Aerogels are synthesized using sol-gel processing followed by supercritical solvent extraction that leaves the original gel structure virtually intact. These studies will elucidate the effects of microgravity on the homogeneity of the microstructure and porosity of aerogel. The presence of poorly controlled microporosity in aerogel leads to material non-uniformity that gives rise to increased light scattering. Investigation of the effect of gravity driven solute flows within microclusters and their effect on condensation and agglomeration reactions will enable us to improve the preparation and properties of aerogel. Increased clarity of images viewed through aerogel and decreased scattering from the pores of aerogel will significantly improve the prospects for large-scale adoption of aerogel in such applications as transparent insulating windows, high performance thermal insulation, and Cherenkov detectors