Antibiotic Prevention of Acute Exacerbations of COPD

An estimated 24 million persons in the United States have COPD on the basis of lung-function testing.1 Globally, COPD is the fourth leading cause of death,2 and in the United States it is the third most common cause of death and chronic complications.3 The average person with COPD has one to two acute exacerbations each year, with wide variation from patient to patient.4 In 2000 in the United States, 726,000 patients were hospitalized with acute exacerbations of COPD.1 During an acute exacerbation, antibiotics are generally administered for 5 to 10 days,5 creating a national burden of 120 million to 480 million antibiotic-days annually. The median hospital stay per exacerbation has been estimated at 9 days.6 In a 2007 Canadian study, the median cost of a hospital stay after an acute exacerbation of COPD was $9,557 (Canadian dollars).7 Acute exacerbations of COPD requiring hospitalization are associated with a 30-day rate of death from any cause of 4 to 30%.6 A study in Sweden showed an all-cause mortality of 26% at 30 days and of 69% at 3 years.8 Acute exacerbations also accelerate the progressive decline in lung function associated with COPD. Overall, the FEV1 falls by approximately 33 ml per year in patients with COPD.4 Each acute exacerbation increases the rate of decline by an additional 2 ml per year4 and by up to 7 ml per year in smokers.

Implementing Power-to-Gas to a bitumen upgrader

Summary Hydrogen is an important commodity in the processing of intermediate bitumen products into a finished petroleum product and for upgrading bitumen into synthetic crude. With the continued extraction of bitumen-rich material from Alberta's oil sands project, there is an opportunity to reduce the greenhouse gas emissions of upgrading and refining operations by using electrolytically produced hydrogen in place of hydrogen produced by steam methane reformation. Recently, a bitumen upgrading facility had been proposed for the city of Sarnia, Ontario because of its pre-existing petroleum processing infrastructure. Using the Ontario electrical system, which has a lower emissions factor than Alberta, the use of electrolytic hydrogen could result in a significant reduction of greenhouse gasses. In this paper, the objective is to determine an optimal system configuration for reducing greenhouse gas emissions while maintaining a low system cost. The analysis is performed with General Algebraic Modelling System tool, a mixed-integer linear optimization in addition to a simple model in Visual Basic. For each case, an economic and environmental analysis is performed including the use of cap-and-trade values for the price of carbon emissions, which are applied to determine the overall economic impact of the emissions reductions. Copyright © 2016 John Wiley & Sons, Ltd

Invariants of the Haldane-Shastry SU(N)SU(N) Chain

Using a formalism developed by Polychronakos, we explicitly construct a set of invariants of the motion for the Haldane-Shastry $SU(N)$ chain.Comment: 11 pages, UVA-92-0

Dyssynchrony Assessment with Tissue Doppler Imaging and Regional Volumetric Analysis by 3D Echocardiography Do Not Predict Long-Term Response to Cardiac Resynchronization Therapy

Background. Currently there are no reliable predictors of response to cardiac resynchronization therapy (CRT) before implantation. We compared pre-CRT left ventricular (LV) dyssynchrony by tissue Doppler imaging (TDI) and regional volumetric analysis by 3-dimensional transthoracic echocardiography (3DTTE) in predicting response to CRT. Methods. Thirty-eight patients (79% nonischemic cardiomyopathy) with symptomatic heart failure who underwent CRT were enrolled. Clinical and echocardiographic responses were defined as improvement in one NYHA class and reduction in LV end-systolic volume by ≥15% respectively. Functional status was assessed by Minnesota Living with Heart Failure questionnaire and 6-minute walk distance. Results. In 33 patients, after CRT for 7.86 ± 2.27 months, there were 24 (73%) clinical and 19 (58%) echocardiographic responders. Functional parameters, LV dimensions, volumes and synchrony by TDI and 3DTTE improved significantly in responders. There was no difference in the number of responders and nonresponders when cut-off values for dyssynchrony by different measurements validated in other trials were applied. Area under receiver-operating-characteristic curve ranged from 0.4 to 0.6. Conclusion. CRT improves clinical and echocardiographic parameters in patients with systolic heart failure. The dyssynchrony measurements by TDI and 3DTTE are not comparable and are unable to predict response to CRT

Feasibility of using the Automated Self-Administered 24-hour (ASA-24) dietary assessment tool in older adults

Background Dietary patterns can impact the trajectories of healthy aging. However, dietary assessment tools can be challenging to use. With the increased use of technology in older adults, we aimed to evaluate the feasibility of older adults completing the online, Automated Self-Administered 24-h (ASA-24) dietary assessment tool. Methods We conducted a randomized, two-period, two-sequence, crossover design of twenty community-dwelling older adults (≥65 years) comparing their preference for completing the ASA-24 alone versus with a research assistant (RA). Participants were recruited via ResearchMatch.com and randomly allocated 1:1 to a sequence of completing both an ASA-24 alone or with an RA, separated by one week. After each session, participants completed an online 11-item feasibility survey (Likert-scale range of 1–5, strongly disagree to strongly agree). Mean and standard deviations were reported for each question. Results Mean age was 69 ± 3.5 years (90% females), with no differences were observed for sex, age, race, ethnicity, education, or income. Neither group felt a need for RA assistance (p = 0.34). However, both groups felt the system was easier to follow with the help of an RA (RA: 4.4 ± 1.3, vs. SA 4.6 ± 0.5, p = 0.65), particularly when they completed the ASA-24 alone, first (p = 0.04). When conducting the ASA-24 alone, there was less confidence the system could be learned quickly (SA 4.5 ± 0.5→3.4 ± 1.0 vs RA 3.4 ± 1.0→3.4 ± 0.7, p = 0.001). The ASA-24 was thought to be less cumbersome after repeated exposure in those concluding with the RA. Conclusion While older adults were able to complete the ASA-24 independently, the use of an RA led to improved confidence. Enhancing the sample diversity in a larger number of participants could provide helpful data to improve the science of dietary assessment

Molecular genetic contribution to the developmental course of attention-deficit hyperactivity disorder

Objective: The developmental trajectory of attention-deficit hyperactivity disorder (ADHD) is variable. Utilizing a longitudinally assessed sample, we investigated the contribution of susceptibility gene variants, previously implicated through pooled or meta-analyses, to the developmental course of Attention-Deficit Hyperactivity Disorder over time. Methods: 151 children (aged 6–12) who met diagnostic criteria for ADHD were assessed using research diagnostic interviews during childhood and 5 years later in adolescence. Severity was defined as total number of ADHD symptoms at baseline and reassessment. Association with variants at DRD4, DRD5, and the dopamine transporter gene, DAT was analyzed using linear regression. Results: As expected, affected individuals showed a decline in ADHD severity over time. The DRD4 48 bp VNTR 7-repeat and DRD5 CA(n) microsatellite marker 148 bp risk alleles were associated with persistent ADHD. Those possessing the DRD4 7 repeat risk allele showed less of a decline in severity at reassessment than those without the risk allele. Conclusions: Those carrying the DRD4 7 risk allele showed greater symptom severity at follow-up and less ADHD reduction over time. These findings support the hypothesis that some susceptibility genes for ADHD also influence its developmental course

Dopamine D2 receptor function is compromised in the brain of the methionine sulfoxide reductase A knockout mouse

Previous research suggests that brain oxidative stress and altered rodent locomotor behavior are linked. We observed bio-behavioral changes in methionine sulfoxide reductase A knockout mice associated with abnormal dopamine signaling. Compromised ability of these knockout mice to reduce methionine sulfoxide enhances accumulation of sulfoxides in proteins. We examined the dopamine D2-receptor function and expression, which has an atypical arrangement and quantity of methionine residues. Indeed, protein expression levels of dopamine D2-receptor were higher in knockout mice compared with wild-type. However, the binding of dopamine D2-receptor agonist was compromised in the same fractions of knockout mice. Coupling efficiency of dopamine D2-receptors to G-proteins was also significantly reduced in knockout mice, supporting the compromised agonist binding. Furthermore, pre-synaptic dopamine release in knockout striatal sections was less responsive than control sections to dopamine D2-receptor ligands. Behaviorally, the locomotor activity of knockout mice was less responsive to the inhibitory effect of quinpirole than wild-type mice. Involvement of specific methionine residue oxidation in the dopamine D2-receptor third intracellular loop is suggested by in vitro studies. We conclude that ablation of methionine sulfoxide reductase can affect dopamine signaling through altering dopamine D2-receptor physiology and may be related to symptoms associated with neurological disorders and diseases