3,294 research outputs found
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
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Efficacy and safety of pharmacotherapies for smoking cessation in anxiety disorders: Subgroup analysis of the randomized, active- and placebo-controlled EAGLES trial.
BackgroundSmoking rates are high in adults with anxiety disorders (ADs), yet little is known about the safety and efficacy of smoking-cessation pharmacotherapies in this group.MethodsPost hoc analyses in 712 smokers with AD (posttraumatic stress disorder [PTSD], n = 192; generalized anxiety disorder [GAD], n = 243; panic disorder [PD], n = 277) and in a nonpsychiatric cohort (NPC; n = 4,028). Participants were randomly assigned to varenicline, bupropion, nicotine-replacement therapy (NRT), or placebo plus weekly smoking-cessation counseling for 12 weeks, with 12 weeks follow-up. General linear models were used to test the effects of treatment group, cohort, and their interaction on neuropsychiatric adverse events (NPSAEs), and continuous abstinence weeks 9-12 (treatment) and 9-24 (follow-up).ResultsNPSAE incidence for PTSD (6.9%), GAD (5.4%), and PD (6.2%) was higher versus NPC (2.1%), regardless of treatment. Across all treatments, smokers with PTSD (odds ratio [OR] = 0.58), GAD (OR = 0.72), and PD (OR = 0.53) had lower continuous abstinence rates weeks 9-12 (CAR9-12) versus NPC. Varenicline demonstrated superior efficacy to placebo in smokers with GAD and PD, respectively (OR = 4.53; 95% confidence interval [CI] = 1.20-17.10; and OR = 8.49; 95% CI = 1.57-45.78); NRT was superior to placebo in smokers with PD (OR = 7.42; 95% CI = 1.37-40.35). While there was no statistically significant effect of any treatment on CAR9-12 for smokers with PTSD, varenicline improved 7-day point prevalence abstinence at end of treatment in this subcohort.ConclusionIndividuals with ADs were more likely than those without psychiatric illness to experience moderate to severe NPSAEs during smoking-cessation attempts, regardless of treatment. While the study was not powered to evaluate abstinence outcomes with these subgroups of smokers with ADs, varenicline provided significant benefit for cessation in those with GAD and PD, while NRT provided significant benefit for those with PD
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Coordination of Geological and Engineering Research in Support of Gulf Coast Co-Production Program
More than 150 gas fields were reviewed, and 25 fields were selected using modified specific selection criteria as outlined by Gregory and others (1983). Further evaluation of these fields is necessary to obtain a new ranking for Gregory's class A, B, and C divisions. A list of the 25 most favorable fields was sent to Eaton Operating Co., who were to approach likely companies to initiate joint ventures in co-production.
Four reservoirs containing dispersed gas were examined for their co-production potential. Reservoirs in Port Acres and Ellis fields produce from the Hackberry Member of the Oligocene Frio Formation, and two reservoirs in Esther field produce from the lower Miocene Planulina Zone. Log-pattern and lithofacies maps, together with stratigraphic position, suggest that the reservoirs are in ancient submarine-fan deposits. Dip-elongate, channel-fill sands are characteristic; reservoir sands pinch out along strike. Growth faults, common in the submarine slope setting, form updip and downdip boundaries, producing combination traps. In Ellis field, co-production accounts for 300 Mcf (8.5 x 106 m3) of gas per day. Port Acres field contains the largest remaining reserves, but other technical and economic factors limit co-production there. Recent drilling has extended primary production and delayed co-production in Esther field. The Gas Research Institute requested that further work on the selection and evaluation of potential co-production gas fields be terminated because funds were required for the Port Arthur project.Bureau of Economic Geolog
Post-traumatic stress disorder following childbirth: an update of current issues and recommendations for future research
Objective:
This paper aimed to report the current status of research in the field of post-traumatic stress disorder following childbirth (PTSD FC), and to update the findings of an earlier 2008 paper.
Background:
A group of international researchers, clinicians and service users met in 2006 to establish the state of clinical and academic knowledge relating to PTSD FC. A paper identified four key areas of research knowledge at that time.
Methods:
Fourteen clinicians and researchers met in Oxford, UK to update the previously published paper relating to PTSD FC. The first part of the meeting focused on updating the four key areas identified previously, and the second part on discussing new and emerging areas of research within the field.
Results:
A number of advances have been made in research within the area of PTSD FC. Prevalence is well established within mothers, several intervention studies have been published, and there is growing interest in new areas: staff and pathways; prevention and early intervention; impact on families and children; special populations; and post-traumatic growth.
Conclusion:
Despite progress, significant gaps remain within the PTSD FC knowledge base. Further research continues to be needed across all areas identified in 2006, and five areas were identified which can be seen as ‘new and emerging’. All of these new areas require further extensive research. Relatively little is still known about PTSD FC
American Passages: A History of the United States
American Passages places a unique emphasis on time as the defining nature of history, how events lead to other events, actions, changes, and often-unexpected outcomes. Rather than grouping facets of historical change into themes or topics, the authors offer students a complete, compelling narrative with balanced coverage of political, economic, social, cultural, military, religious, and intellectual history.https://scholarship.richmond.edu/bookshelf/1276/thumbnail.jp
Charge Transfer in Partition Theory
The recently proposed Partition Theory (PT) [J.Phys.Chem.A 111, 2229 (2007)]
is illustrated on a simple one-dimensional model of a heteronuclear diatomic
molecule. It is shown that a sharp definition for the charge of molecular
fragments emerges from PT, and that the ensuing population analysis can be used
to study how charge redistributes during dissociation and the implications of
that redistribution for the dipole moment. Interpreting small differences
between the isolated parts' ionization potentials as due to environmental
inhomogeneities, we gain insight into how electron localization takes place in
H2+ as the molecule dissociates. Furthermore, by studying the preservation of
the shapes of the parts as different parameters of the model are varied, we
address the issue of transferability of the parts. We find good transferability
within the chemically meaningful parameter regime, raising hopes that PT will
prove useful in chemical applications.Comment: 12 pages, 16 figure
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
Projected seniority-two orbital optimization of the Antisymmetric Product of one-reference orbital Geminal
We present a new, non-variational orbital-optimization scheme for the
Antisymmetric Product of one-reference orbital Geminal wave function. Our
approach is motivated by the observation that an orbital-optimized
seniority-zero configuration interaction (CI) expansion yields similar results
to an orbital-optimized seniority-zero-plus-two CI expansion [J. Chem. Phys.,
135, 044119 (2011)]. A numerical analysis is performed for the C, LiF and
CH molecules as well as for the symmetric stretching of hypothetical
(linear) hydrogen chains. For these test cases, the proposed
orbital-optimization protocol yields similar results to its variational orbital
optimization counterpart, but prevents symmetry-breaking of molecular orbitals
in most cases.Comment: 7 pages, 2 figure
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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
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