Search results for "35"
showing 10 items of 2413 documents
Prenatal exposure to organochlorine compounds and lung function during childhood
2019
Introduction: Prenatal exposure to organochlorine compounds (OCs) can increase the risk of reported respiratory symptoms in children. It remains unclear whether these compounds can also impact on lung function. We assessed the association between prenatal exposure to OCs and lung function during childhood. Methods: We included 1308 mother-child pairs enrolled in a prospective cohort study. Prenatal concentrations of p,p′-dichlorodiphenyltrichloroethane [p,p′-DDT], p,p′-dichlorodiphenyldichloroethylene [p,p′-DDE], hexachlorobenzene [HCB], and seven polychlorinated biphenyls [PCBs] were measured in cord blood. Spirometry was performed in the offspring at ages 4 (n = 636) and 7 years (n = 1192…
Treatment algorithm for spontaneous spinal infections: A review of the literature
2019
Background: Primary spinal infections are rare pathologies with an estimated incidence of 5% of all osteomyelitis. The diagnosis can be challenging and this might result in a late identification. The etiological diagnosis is the primary concern to determine the most appropriate treatment. The aim of this review article was to identify the importance of a methodological attitude toward accurate and prompt diagnosis using an algorithm to aid on spinal infection management. Methods: A search was done on spinal infection in some databases including PubMed, ISI Web of Knowledge, Google Scholar, Ebsco, Embasco, and Scopus. Results: Literature reveals that on the basis of a clinical suspicion, the…
Impact of COVID-19 on Sustainable University Sports: Analysis of Physical Activity and Positive and Negative Affects in Athletes
2021
The suspension of university activities due to the pandemic affected training and sports competitions. However, some universities adapted online education, allowing students to carry out their activities without being infected by the virus. The aim of this study was to find out the impact of the pandemic on physical activity levels and the positive and negative effects on Chilean university athletes. The information was obtained by applying the PANAS scale and demographic and physical activity variables were also measured. The sample of Chilean university athletes (n = 254) were aged between 18 and 31 years (M = 22.17
Technology standard diffusion and negative network externalities: a lesson from the third Browser War
2009
This paper presents a new model for technology standard diffusion that highlights the importance of negative network externalities in some fields of technology product such as web browsers. Again, as often happened in this research field, motivation and suggestion for such a research has been acquired from the evolution of the web browser war. So, in the paper, the main literature concerning standard diffusion has been reviewed in conjunction with web browser evolution, and the necessity of a new development of technology standard diffusion models is highlighted and supported by empirical evidences.
Problem zdrady w dobie bezkrólewia po smierci Augusta II i polskiej wojny sukcesyjnej 1733-1735
2013
Ziemie Prus w trakcie polskiej wojny sukcesyjnej i wojny siedmioletniej
2021
W trakcie licznych konfliktów zbrojnych rozegranych w osiemnastowiecznej Europie Prusy Wschodnie tylko raz były teatrem działań wojennych: latem 1757 r. – zimą 1758 r. Dwukrotnie jednak działania zbrojne toczyły się nad jej granicami, a w latach 1734-1735 przez prowincje pruską przechodziły transporty i oddziały walczących wojsk. Taka postawa nie przyniosła wówczas królowi pruskiemu żadnych korzyści, ale też uchroniła Prusy Wschodnie oraz jego mieszkańców przed ewentualnymi negatywnymi skutkami wojny na terytorium Rzeczpospolitej. Jednak ponad dwadzieścia lat później Prusy Wschodnie nie uniknęły już okrucieństw wojny. Król Fryderyk II atakiem w sierpniu 1756 r. na Saksonię chciał uprzedzić …
One-dimensional random walks with self-blocking immigration
2017
We consider a system of independent one-dimensional random walkers where new particles are added at the origin at fixed rate whenever there is no older particle present at the origin. A Poisson ansatz leads to a semi-linear lattice heat equation and predicts that starting from the empty configuration the total number of particles grows as $c \sqrt{t} \log t$. We confirm this prediction and also describe the asymptotic macroscopic profile of the particle configuration.
Disorder relevance for the random walk pinning model in dimension 3
2011
We study the continuous time version of the random walk pinning model, where conditioned on a continuous time random walk Y on Z^d with jump rate \rho>0, which plays the role of disorder, the law up to time t of a second independent random walk X with jump rate 1 is Gibbs transformed with weight e^{\beta L_t(X,Y)}, where L_t(X,Y) is the collision local time between X and Y up to time t. As the inverse temperature \beta varies, the model undergoes a localization-delocalization transition at some critical \beta_c>=0. A natural question is whether or not there is disorder relevance, namely whether or not \beta_c differs from the critical point \beta_c^{ann} for the annealed model. In Birkner a…
Random walks in dynamic random environments and ancestry under local population regulation
2015
We consider random walks in dynamic random environments, with an environment generated by the time-reversal of a Markov process from the oriented percolation universality class. If the influence of the random medium on the walk is small in space-time regions where the medium is typical, we obtain a law of large numbers and an averaged central limit theorem for the walk via a regeneration construction under suitable coarse-graining. Such random walks occur naturally as spatial embeddings of ancestral lineages in spatial population models with local regulation. We verify that our assumptions hold for logistic branching random walks when the population density is sufficiently high.
Time-dependent weak rate of convergence for functions of generalized bounded variation
2016
Let $W$ denote the Brownian motion. For any exponentially bounded Borel function $g$ the function $u$ defined by $u(t,x)= \mathbb{E}[g(x{+}\sigma W_{T-t})]$ is the stochastic solution of the backward heat equation with terminal condition $g$. Let $u^n(t,x)$ denote the corresponding approximation generated by a simple symmetric random walk with time steps $2T/n$ and space steps $\pm \sigma \sqrt{T/n}$ where $\sigma > 0$. For quite irregular terminal conditions $g$ (bounded variation on compact intervals, locally H\"older continuous) the rate of convergence of $u^n(t,x)$ to $u(t,x)$ is considered, and also the behavior of the error $u^n(t,x)-u(t,x)$ as $t$ tends to $T$