2,532 research outputs found
Association between fire-safe cigarette legislation and residential fire deaths in the United States
Abstract: Background: Cigarettes and other tobacco-related smoking products have traditionally been a major ignition source for residential fire deaths. In the United States, all 50 states and the District of Columbia have passed laws requiring that cigarettes self-extinguish if they are not being smoked (so-called fire-safe cigarette laws). The purpose of this study was to quantify the association between state-level implementation of fire-safe cigarette legislation and the rate of residential fire death. Methods: Poisson regression was used to analyze state-years data. Main intervention: Implementation dates for fire-safe cigarette legislation in each state. Outcome: Residential fire mortality rate. Results: Implementation of fire-safe cigarette legislation was associated with a 19% reduction in overall residential fire mortality rates, adjusted for demographic differences between states (rate ratio = 0.81, 95% confidence interval: 0.79, 0.84). This is approximately similar to the estimated proportion of residential fire deaths in which smoking materials are an ignition source (23%). Legislation implementation was associated with a protective effect for every age, sex, race, and ethnicity strata that we examined. State-specific residential fire mortality death rates decreased (defined as a drop of at least 5%) in 32 states after fire-safe cigarette legislation was implemented. In 12 states there was either less than a 5% decrease or an increase, and seven states had insufficient deaths to evaluate state-level changes. Conclusions: Implementation of fire-safe cigarette is associated with reductions in residential fire mortality rates
Construction of n-Lie algebras and n-ary Hom-Nambu-Lie algebras
We present a procedure to construct (n+1)-Hom-Nambu-Lie algebras from
n-Hom-Nambu-Lie algebras equipped with a generalized trace function. It turns
out that the implications of the compatibility conditions, that are necessary
for this construction, can be understood in terms of the kernel of the trace
function and the range of the twisting maps. Furthermore, we investigate the
possibility of defining (n+k)-Lie algebras from n-Lie algebras and a k-form
satisfying certain conditions
Surface Modification of Aluminium Alloy with Super Hydrophobic Characteristics using Immersion and Spray-Coating Method
Delayed presentation of symptomatic breast cancers in Hong Kong: Experience in a public cancer centre
Objective Delayed presentation is an important obstacle to improving cancer treatment outcomes. We aimed to study the magnitude of this problem in Hong Kong and the factors associated with delayed presentation of patients with symptomatic breast cancers. Design Retrospective study using self-administered questionnaires. Setting Clinical Oncology Department in a regional public hospital in Hong Kong. Patients A total of 158 Chinese women with breast cancer referred to our hospital between October 2006 and December 2007 consented to participate in this study. Among these, 59 (37%) patients were referred after having surgery in private sector. Results The mean total delay (from first symptom to treatment) was 22 weeks. The mean patient delay (from first symptom to first consultation) was 13 weeks, constituting the largest component (60%) of the total delay. After symptom onset, the delay exceeded 12 weeks for consulting a doctor in 29%, and for receipt of treatment in 52% of them. Low family income (<HK$5000 per month; P<0.001) and surgery in public hospitals (P=0.013) were both independent predictors of patient delay. Surgery in public hospitals (P=0.006) and low family income (P=0.005) were the only predictors of doctor/system delay and total delay, respectively. Conclusions Delayed presentation and treatment of symptomatic breast cancer remains an important issue in Hong Kong. Apart from socio-economic factors, limited access to public medical care was likely an important contributing factor in delays related to patients as well as to doctor/system.published_or_final_versio
Nanofluid-based Nanocarbons An Investigation of Thermal Conductivity Performance
This paper presents a study of thermal conductivity performance, using a nanofluid-based nanocarbon formulate, with three different types of nanocarbons. NC300, NC200, and commercial carbon nanotube (CNT)were used together with Sodium Dodecyl Sulphate (SDS) as a dispersant, and deionized water as a solvent. A weighted ratio of the nanocarbons (0.4 - 1.0wt%) was set-up and the thermal conductivity was measured at 6°C, 25°C, and 45°C using a KD2 Pro thermal properties analyser. The results showed that NC300 with 1wt% of nanocarbons at 45°C gave the highest improvement of almost 30%, compared to deionized water. Meanwhile, the best nanofluid, based on prepared nanocarbons (NC200) and commercial CNT, showed improvement of more than 9% and 12%, respectively, with the addition of 0.6wt% nanocarbons at 45°C. Morphology analysis using electron microscopy, revealed the structural properties of the nanocarbons. NC300 showed a loose CNT with an average diameter of 70-150nm. NC200 are supported by nanocarbons with an average diameter of 10- 30nm. Meanwhile, the commercial CNT showed a similar characteristic to that of NC300. Even though NC200 had the smallest diameter of all nanocarbons, (which should provide the highest surface area), the larger sizes of the activated carbons, as a nanocarbon support, are expected to reduce thermal conductivity performance
Non-ancient solution of the Ricci flow
For any complete noncompact Khler manifold with nonnegative and
bounded holomorphic bisectional curvature,we provide the necessary and
sufficient condition for non-ancient solution to the Ricci flow in this paper.Comment: seven pages, latex fil
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