1,209 research outputs found
Izloženost ambijentalnomu duhanskomu dimu na radnome mjestu u Makedoniji: kako sada stojimo?
To assess the prevalence and the level of exposure to environmental tobacco smoke (ETS) in the workplace after the enactment of the law restricting indoor smoking in Macedonia, we performed a cross-sectional, self-administered questionnaire study including 372 never-smoking workers recruited from six workplaces. We found a high prevalence of workers exposed to ETS in the workplace (27.4 %) with no significant difference between particular occupation groups. We found no significant difference in the prevalence of passive smokers in the workplace between this study and our study conducted before the law was enacted (31.5 % vs. 27.4 %, P=0.324). The prevalence of workers exposed to ETS for less than three hours a day was significantly lower than of passive smokers with longer exposure (28.4 % vs. 71.6 %, P=0.038). The prevalence of workers exposed to ETS from less than 10 cigarettes smoked by coworkers per day was lower than the prevalence of workers with higher exposure, but statistical significance was not reached (37.9 % vs. 62.1 %, P=0.087). Our findings indicate a high prevalence and a high level of exposure to ETS in the workplace, which calls for stricter adherence to smoking-free legislation or even the total ban of smoking in the workplace.Ovo je ispitivanje obuhvatilo 372 radnika na šest različitih radnih mjesta koji nikad nisu pušili kako bi se procijenila zastupljenost osoba izloženih duhanskomu dimu na radnome mjestu i razina njihove izloženosti nakon zakonskih ograničenja pušenja u zatvorenim prostorijama u Makedoniji. Ispitivanje je provedeno s pomoću upitnika koji su radnici ispunjavali sami. Utvrdili smo visoku zastupljenost radnika izloženih ambijentalnomu duhanskomu dimu na radnome mjestu (27,4 %) te nisu zamijećene statistički značajne razlike među zanimanjima. Nisu uočene značajne razlike između zastupljenosti pasivnih pušača na radnome mjestu u ovome ispitivanju i u našem ranijem ispitivanju, kada još nije na snagu stupio zakon o ograničenju pušenja (31,5 % naprema 27,4 %, P=0,324). Zastupljenost radnika izloženih ambijentalnomu duhanskomu dimu ne dulje od tri sata na dan bila je statistički značajno niža negoli onih čija je izloženost trajala duže (28,4 % naprema 71,6 %, P=0,038). Zastupljenost radnika koji su bili izloženi dimu kolega koji su pušili manje od 10 cigareta na dan bila je niža negoli onih s većom izloženosti, ali razlika nije bila statistički značajna (37,9 % naprema 62,1 %, P=0,087). Naši rezultati potvrđuju da i dalje postoje visoka zastupljenost izloženih radnika i visoke razine izloženosti ambijentalnomu duhanskomu dimu na radnome mjestu, što upućuje na potrebu uvođenja strožih zakona o zabrani pušenja
The Gaussian approximation for multi-color generalized Friedman's urn model
The Friedman's urn model is a popular urn model which is widely used in many
disciplines. In particular, it is extensively used in treatment allocation
schemes in clinical trials. In this paper, we prove that both the urn
composition process and the allocation proportion process can be approximated
by a multi-dimensional Gaussian process almost surely for a multi-color
generalized Friedman's urn model with non-homogeneous generating matrices. The
Gaussian process is a solution of a stochastic differential equation. This
Gaussian approximation together with the properties of the Gaussian process is
important for the understanding of the behavior of the urn process and is also
useful for statistical inferences. As an application, we obtain the asymptotic
properties including the asymptotic normality and the law of the iterated
logarithm for a multi-color generalized Friedman's urn model as well as the
randomized-play-the-winner rule as a special case
Companions of Stars: From Other Stars to Brown Dwarfs to Planets: The Discovery of the First Methane Brown Dwarf
The discovery of the first methane brown dwarf provides a framework for
describing the important advances in both fundamental physics and astrophysics
that are due to the study of companions of stars. I present a few highlights of
the history of this subject along with details of the discovery of the brown
dwarf Gliese 229B. The nature of companions of stars is discussed with an
attempt to avoid biases induced by anthropocentric nomenclature. With the newer
types of remote reconnaissance of nearby stars and their systems of companions,
an exciting and perhaps even more profound set of contributions to science is
within reach in the near future. This includes an exploration of the diversity
of planets in the universe and perhaps soon the first solid evidence for
biological activity outside our Solar System.Comment: 31 pages, 13 figure
A Non-Lévy Random Walk in Chacma Baboons: What Does It Mean?
The Lévy walk is found from amoebas to humans and has been described as the optimal strategy for food research. Recent results, however, have generated controversy about this conclusion since animals also display alternatives to the Lévy walk such as the Brownian walk or mental maps and because movement patterns found in some species only seem to depend on food patches distribution. Here I show that movement patterns of chacma baboons do not follow a Lévy walk but a Brownian process. Moreover this Brownian walk is not the main process responsible for movement patterns of baboons. Findings about their speed and trajectories show that baboons use metal maps and memory to find resources. Thus the Brownian process found in this species appears to be more dependent on the environment or might be an alternative when known food patches are depleted and when animals have to find new resources
Quantifying the real life risk profile of inhaled corticosteroids in COPD by record linkage analysis
BACKGROUND: Inhaled corticosteroids (ICS), especially when prescribed in combination with long-acting β(2) agonists have been shown to improve COPD outcomes. Although there is consistent evidence linking ICS with adverse effects such as pneumonia, the complete risk profile is unclear with conflicting evidence on any association between ICS and the incidence or worsening of existing diabetes, cataracts and fractures. We investigated this using record linkage in a Dundee COPD population. METHODS: A record linkage study linking COPD and diabetes datasets with prescription, hospitalisation and mortality data via a unique Community Health Index (CHI) number. A Cox regression model was used to determine the association between ICS use and new diabetes or worsening of existing diabetes and hospitalisations for pneumonia, fractures or cataracts after adjusting for potential confounders. A time dependent analysis of exposure comparing time on versus off ICS was used to take into account patients changing their exposure status during follow-up and to prevent immortal time bias. RESULTS: 4305 subjects (3243 exposed to ICS, total of 17,229 person-years of exposure and 1062 non exposed, with a follow-up of 4,508 patient-years) were eligible for the study. There were 239 cases of new diabetes (DM) and 265 cases of worsening DM, 550 admissions for pneumonia, 288 hospitalisations for fracture and 505 cataract related admissions. The hazard ratio for the association between cumulative ICS and outcomes were 0.70 (0.43-1.12), 0.57 (0.24-1.37), 1.38 (1.09-1.74), 1.08 (0.73-1.59) and 1.42 (1.07-1.88) after multivariate analysis respectively. CONCLUSION: The use of ICS in our cohort was not associated with new onset of diabetes, worsening of existing diabetes or fracture hospitalisation. There was however an association with increased cataracts and pneumonia hospitalisations
Cu-II materials - From crystal chemistry to magnetic model compounds
Based on electronic structure calculations within the density functional theory, we report a systematic approach for the modelling of low-dimensional Cu-II materials. Combining concepts of crystal chemistry with ab initio-based magnetic models, we present a systematic study of recently discovered compounds. Our calculation results are in good agreement with thermodynamic and magnetic measurements, suggesting the presented approach as a well-directed route to explore the magnetic phase diagram of low-dimensional Cu-II systems. (c) 2007 NIMS and Elsevier Ltd. All rights reserved
Ensemble approach for generalized network dismantling
Finding a set of nodes in a network, whose removal fragments the network
below some target size at minimal cost is called network dismantling problem
and it belongs to the NP-hard computational class. In this paper, we explore
the (generalized) network dismantling problem by exploring the spectral
approximation with the variant of the power-iteration method. In particular, we
explore the network dismantling solution landscape by creating the ensemble of
possible solutions from different initial conditions and a different number of
iterations of the spectral approximation.Comment: 11 Pages, 4 Figures, 4 Table
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