161 research outputs found
Adsorption of Hydrocarbons Using Natural Adsorbents of Plant Origin
The paper investigates adsorption activity of natural sorbents to be used to clean up water surface from hydrocarbons under various temperatures. The natural adsorbents were compared by their oil capacity, buoyancy, and water absorption. It was revealed that Nature sorb (Canada) and Sphagnum Dill (Russia) natural sorbents demonstrate good buoyancy (up to 700 hours) and great oil capacity, and better sorption properties in comparison with the sawdust. The natural sorbents introduced can increase the efficiency of water surface cleaning-up until the water is almost clean and the residual oil content in water is less than 0.03 g/l
Exhaled nitric oxide in a population-based study of Southern California Schoolchildren
<p>Abstract</p> <p>Background</p> <p>Determinants of exhaled nitric oxide (FeNO) need to be understood better to maximize the value of FeNO measurement in clinical practice and research. Our aim was to identify significant predictors of FeNO in an initial cross-sectional survey of southern California schoolchildren, part of a larger longitudinal study of asthma incidence.</p> <p>Methods</p> <p>During one school year, we measured FeNO at 100 ml/sec flow, using a validated offline technique, in 2568 children of age 7–10 yr. We estimated online (50 ml/sec flow) FeNO using a prediction equation from a separate smaller study with adjustment for offline measurement artifacts, and analyzed its relationship to clinical and demographic characteristics.</p> <p>Results</p> <p>FeNO was lognormally distributed with geometric means ranging from 11 ppb in children without atopy or asthma to 16 ppb in children with allergic asthma. Although effects of atopy and asthma were highly significant, ranges of FeNO for children with and without those conditions overlapped substantially. FeNO was significantly higher in subjects aged > 9, compared to younger subjects. Asian-American boys showed significantly higher FeNO than children of all other sex/ethnic groups; Hispanics and African-Americans of both sexes averaged slightly higher than non-Hispanic whites. Increasing height-for-age had no significant effect, but increasing weight-for-height was associated with decreasing FeNO.</p> <p>Conclusion</p> <p>FeNO measured offline is a useful biomarker for airway inflammation in large population-based studies. Further investigation of age, ethnicity, body-size, and genetic influences is needed, since they may contribute to substantial variation in FeNO.</p
Age-related delay in information accrual for faces: Evidence from a parametric, single-trial EEG approach
Background: In this study, we quantified age-related changes in the time-course of face processing
by means of an innovative single-trial ERP approach. Unlike analyses used in previous studies, our
approach does not rely on peak measurements and can provide a more sensitive measure of
processing delays. Young and old adults (mean ages 22 and 70 years) performed a non-speeded
discrimination task between two faces. The phase spectrum of these faces was manipulated
parametrically to create pictures that ranged between pure noise (0% phase information) and the
undistorted signal (100% phase information), with five intermediate steps.
Results: Behavioural 75% correct thresholds were on average lower, and maximum accuracy was
higher, in younger than older observers. ERPs from each subject were entered into a single-trial
general linear regression model to identify variations in neural activity statistically associated with
changes in image structure. The earliest age-related ERP differences occurred in the time window
of the N170. Older observers had a significantly stronger N170 in response to noise, but this age
difference decreased with increasing phase information. Overall, manipulating image phase
information had a greater effect on ERPs from younger observers, which was quantified using a
hierarchical modelling approach. Importantly, visual activity was modulated by the same stimulus
parameters in younger and older subjects. The fit of the model, indexed by R2, was computed at
multiple post-stimulus time points. The time-course of the R2 function showed a significantly slower
processing in older observers starting around 120 ms after stimulus onset. This age-related delay
increased over time to reach a maximum around 190 ms, at which latency younger observers had
around 50 ms time lead over older observers.
Conclusion: Using a component-free ERP analysis that provides a precise timing of the visual
system sensitivity to image structure, the current study demonstrates that older observers
accumulate face information more slowly than younger subjects. Additionally, the N170 appears to
be less face-sensitive in older observers
Asthma
Asthma is the most common respiratory disorder in Canada. Despite significant improvement in the diagnosis and management of this disorder, the majority of Canadians with asthma remain poorly controlled. In most patients, however, control can be achieved through the use of avoidance measures and appropriate pharmacological interventions. Inhaled corticosteroids (ICSs) represent the standard of care for the majority of patients. Combination ICS/long-acting beta2-agonists (LABA) inhalers are preferred for most adults who fail to achieve control with ICS therapy. Allergen-specific immunotherapy represents a potentially disease-modifying therapy for many patients with asthma, but should only be prescribed by physicians with appropriate training in allergy. Regular monitoring of asthma control, adherence to therapy and inhaler technique are also essential components of asthma management. This article provides a review of current literature and guidelines for the appropriate diagnosis and management of asthma
Role of the Subunits Interactions in the Conformational Transitions in Adult Human Hemoglobin: an Explicit Solvent Molecular Dynamics Study
Hemoglobin exhibits allosteric structural changes upon ligand binding due to
the dynamic interactions between the ligand binding sites, the amino acids
residues and some other solutes present under physiological conditions. In the
present study, the dynamical and quaternary structural changes occurring in two
unligated (deoxy-) T structures, and two fully ligated (oxy-) R, R2 structures
of adult human hemoglobin were investigated with molecular dynamics. It is
shown that, in the sub-microsecond time scale, there is no marked difference in
the global dynamics of the amino acids residues in both the oxy- and the deoxy-
forms of the individual structures. In addition, the R, R2 are relatively
stable and do not present quaternary conformational changes within the time
scale of our simulations while the T structure is dynamically more flexible and
exhibited the T\rightarrow R quaternary conformational transition, which is
propagated by the relative rotation of the residues at the {\alpha}1{\beta}2
and {\alpha}2{\beta}1 interface.Comment: Reprinted (adapted) with permission from J. Phys. Chem. B
DOI:10.1021/jp3022908. Copyright (2012) American Chemical Societ
Prevalence of asthma symptoms based on the European Community Respiratory Health Survey questionnaire and FENO in university students: gender differences in symptoms and FENO
<p>Abstract</p> <p>Background</p> <p>The fractional concentration of nitric oxide in exhaled air (F<smcaps>E</smcaps>NO) is used as a biomarker of eosinophilic airway inflammation. F<smcaps>E</smcaps>NO is increased in patients with asthma. The relationship between subjective asthma symptoms and airway inflammation is an important issue. We expected that the subjective asthma symptoms in women might be different from those in men. Therefore, we investigated the gender differences of asthma symptoms and F<smcaps>E</smcaps>NO in a survey of asthma prevalence in university students.</p> <p>Methods</p> <p>The information about asthma symptoms was obtained from answers to the European Community Respiratory Health Survey (ECRHS) questionnaire, and F<smcaps>E</smcaps>NO was measured by an offline method in 640 students who were informed of this study and consented to participate.</p> <p>Results</p> <p>The prevalence of asthma symptoms on the basis of data obtained from 584 students (266 men and 318 women), ranging in age from 18 to 24 years, was analyzed. Wheeze, chest tightness, an attack of shortness of breath, or an attack of cough within the last year was observed in 13.2% of 584 students. When 38.0 ppb was used as the cut-off value of F<smcaps>E</smcaps>NO to make the diagnosis of asthma, the sensitivity was 86.8% and the specificity was 74.0%. F<smcaps>E</smcaps>NO was ≥ 38.0 ppb in 32.7% of students. F<smcaps>E</smcaps>NO was higher in men than in women. The prevalence of asthma symptoms estimated by considering F<smcaps>E</smcaps>NO was 7.2%; the prevalence was greater in men (9.4%) than women (5.3%). A F<smcaps>E</smcaps>NO ≥ 38.0 ppb was common in students who reported wheeze, but not in students, especially women, who reported cough attacks.</p> <p>Conclusions</p> <p>The prevalence of asthma symptoms in university students age 18 to 24 years in Japan was estimated to be 7.2% on the basis of F<smcaps>E</smcaps>NO levels as well as subjective symptoms. Gender differences were observed in both F<smcaps>E</smcaps>NO levels and asthma symptoms reflecting the presence of eosinophilic airway inflammation.</p> <p>Trial registration number</p> <p>UMIN000003244</p
Novel adaptive muting technique for packet loss concealment of ITU-T G.722 using optimized parametric shaping functions
Strongly Interacting Neutrinos and the Highest Energy Cosmic Rays
Cosmic rays of energies larger than the Greisen-Zatsepin-Kuzmin (GZK) cutoff
may be neutrinos if they acquire strong interactions due to a ``precocious
unification'' of forces. A scenario for this to happen is outlined. There is no
contradiction with precision measurements carried out at LEP and SLAC.
Observable consequences at LHC and future neutrino detectors are discussed.Comment: 9 pages, LaTeX2e, no macros, 2 eps. figures. Uses epsf.te
Long-term complications of congenital esophageal atresia–single institution experience
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