Localized defects in a cellular automaton model for traffic flow with phase separation

We study the impact of a localized defect in a cellular automaton model for traffic flow which exhibits metastable states and phase separation. The defect is implemented by locally limiting the maximal possible flow through an increase of the deceleration probability. Depending on the magnitude of the defect three phases can be identified in the system. One of these phases shows the characteristics of stop-and-go traffic which can not be found in the model without lattice defect. Thus our results provide evidence that even in a model with strong phase separation stop-and-go traffic can occur if local defects exist. From a physical point of view the model describes the competition between two mechanisms of phase separation.Comment: 14 pages, 7 figure

Histone Deacetylase Inhibitors in Malignant Pleural Mesothelioma: Preclinical Rationale and Clinical Trials

AbstractMalignant pleural mesothelioma (MPM) is a rare and aggressive cancer of the mesothelium with only a limited range of treatment options that are largely ineffective in improving survival. Recent efforts have turned toward the analysis of specific, dysregulated biologic pathways for insight into new treatment targets. Epigenetic regulation of tumor suppressor genes through chromatin condensation and decondensation has emerged as an important mechanism that leads to tumorogenesis. A family of histone acetyltransferases and deacetylases regulates this balance, with the latter facilitating chromatin condensation, thus preventing gene transcription, resulting in the loss of heterozygosity of tumor suppressors. Inhibition of this process, coupled with a similar inhibition of nonhistone protein deacetylation, ultimately leads to the promotion of apoptosis, cell cycle arrest, and inhibition of angiogenesis. An increasing amount of preclinical data highlighting the effectiveness of histone deacetylase inhibition in MPM cell lines and mouse xenograft models has led to a number of early phase clinical trials in patients with MPM. The results of these efforts have led to a multicenter, randomized, placebo-controlled phase III study of the histone deacetylase inhibitor vorinostat in patients with advanced MPM, offering hope for a new and effective therapy in patients with this disease

An analysis of the impact of tax changes between 1996 and 2012 on the tax burden of individuals in South Africa

The objective of the research was to determine whether the changes made to the Income Tax Act, 58 of 1962 between 1996 and 2012, in respect of fringe benefits, allowances, deductions, tax tables and rebates, where these changes apply to individuals, have resulted in relieving the tax burden placed on individuals in South Africa. The research was conducted by means of a critical analysis of documentary data with specific reference to the Income Tax Act, annual amendments to the Income Tax Act, statistics relating to tax collections, the National Budget and the Annual Budget Speeches as tabled by the Minister of Finance. These sources were utilised to analyse the amendments to the Act that have taken place over the last sixteen years, where they impact on the tax liability of an individual. A hypothetical example incorporating all the variables identified in the analysis of the tax amendments was used to provide a detailed analysis of the tax payable by an individual on an inflation-adjusted year-on-year basis. The research found that, whilst personal income tax is still the largest contributor to the national budget of South Africa, its contribution has decreased from 40.2 percent in 1996 to 34.3 percent in 2010. This decrease is partly attributable to the extensive tax reforms undertaken by Government with respect to the tax tables, resulting in a reduction in the marginal tax rates and increased tax rebates which had the effect that the individual taxpayer (as illustrated in the hypothetical example) experienced a decrease in the average rate of tax. In contrast to this, the increase in the taxable income of the hypothetical taxpayer exceeded the average rate of inflation over the period. Furthermore, the actual revenue collected by the government from personal income tax has increased by approximately eleven percent per annum, which far exceeds the average inflation rate of 6.23 percent. The research indicated that this could be the result of the increase in the taxable value of fringe benefits, specifically medical aid contributions and company cars, as well as the inclusion of the full amount of allowances in taxable income and the limits placed on the deductions an individual may claim. The result is a broadening of the tax base of the individual taxpayer. Therefore, although the government may have achieved its goal of a fairer tax system, the amendments made to fringe benefits, allowances and deductions have resulted in an increase in the average taxable income of individuals

The Antitrust Duty to Deal and Intellectual Property Rights

This Article discusses how courts have addressed so-called ‘ duty-to-deal antitrust claims involving intellectual property, and what they should do in those circumstances to ensure appropriate deference to the competition goals of intellectual property doctrine. Part II discusses duty-to-deal principles in the general case, where intellectual property rights are not at issue, noting that hard and fast rules have yet to emerge. Part III discusses the approaches courts have taken in the intellectual property context and contends that, although many courts have conducted their analyses with a view to the objectives of patent law, at least two have not, with potentially detrimental consequences for the preservation of patent rights. Part IV discusses two recent cases involving significant antitrust and intellectual property issues—In re Intel Corp. and United States v. Microsoft. Each of the cases highlights a different facet that courts must consider as they confront an increasing number of cases with intellectual property and antitrust implications. The Article concludes by suggesting that any doctrine endeavoring to navigate the waters of intellectual property/antitrust cases must devote considerable attention to patent law and its objectives. When that attention is given, there are only a few circumstances (involving intellectual property rights) in which a duty to deal should be imposed

Superroughening by linear growth equations with spatiotemporally correlated noise

[[abstract]]We give an extensive study on a class of interfacial superroughening processes with finite lateral system size in 1+1 dimensions described by linear growth equations with spatiotemporally power-law decaying correlated noise. Since some of these processes have an extremely long relaxation time, we first develop a very efficient method capable of simulating the interface morphology of these growth processes even in very late time. We numerically observe that this class of superrough growth processes indeed gradually develops macroscopic structures with the lateral size comparable to the lateral system size. Through the rigorous analytical study of the equal-time height difference correlation function, the different-time height difference correlation function, and the local width, we explicitly evaluate not only the leading anomalous dynamic scaling term but also all the subleading anomalous dynamic scaling terms which dominate over the ordinary dynamic scaling term. Moreover, the relation between the macroscopic structure formation and anomalous interfacial roughening of the superrough growth processes is analytically investigated in detail.[[incitationindex]]SCI[[booktype]]紙

Why We Read Wikipedia

Wikipedia is one of the most popular sites on the Web, with millions of users relying on it to satisfy a broad range of information needs every day. Although it is crucial to understand what exactly these needs are in order to be able to meet them, little is currently known about why users visit Wikipedia. The goal of this paper is to fill this gap by combining a survey of Wikipedia readers with a log-based analysis of user activity. Based on an initial series of user surveys, we build a taxonomy of Wikipedia use cases along several dimensions, capturing users' motivations to visit Wikipedia, the depth of knowledge they are seeking, and their knowledge of the topic of interest prior to visiting Wikipedia. Then, we quantify the prevalence of these use cases via a large-scale user survey conducted on live Wikipedia with almost 30,000 responses. Our analyses highlight the variety of factors driving users to Wikipedia, such as current events, media coverage of a topic, personal curiosity, work or school assignments, or boredom. Finally, we match survey responses to the respondents' digital traces in Wikipedia's server logs, enabling the discovery of behavioral patterns associated with specific use cases. For instance, we observe long and fast-paced page sequences across topics for users who are bored or exploring randomly, whereas those using Wikipedia for work or school spend more time on individual articles focused on topics such as science. Our findings advance our understanding of reader motivations and behavior on Wikipedia and can have implications for developers aiming to improve Wikipedia's user experience, editors striving to cater to their readers' needs, third-party services (such as search engines) providing access to Wikipedia content, and researchers aiming to build tools such as recommendation engines.Comment: Published in WWW'17; v2 fixes caption of Table

Sliding Objects with Random Friction

We study the motion of elastic networks driven over a random substrate. Our model which includes local friction forces leads to complex dynamical behavior. We find a transition to a sliding state which belongs to a new universality class. The phase diagram comprises of a pinned state, a stick-slip motion phase, and a free motion phase.Comment: proceedings of Conference "Percolation and Disordered Systems: *Theory and Applications*", Giessen (Germany) 1998, see http://ory.ph.biu.ac.il/PERCOLATION98/ , 12 pages, 5 figures, in press, will be published in Physica

Diffusive persistence and the `sign-time' distribution

We present a new method for extracting the persistence exponent theta for the diffusion equation, based on the distribution P of `sign-times'. With the aid of a numerically verified Ansatz for P we derive an exact formula for theta in arbitrary spatial dimension d. Our results are in excellent agreement with previous numerical studies. Furthermore, our results indicate a qualitative change in P above d ~ 36, signalling the existence of a sharp change in the ergodic properties of the diffusion field.Comment: 5 pages, 2 tar gzip figures (Latex), subm. to PRE (Rapid Comm), new reference adde

Clinical Characteristics of Patients with Malignant Pleural Mesothelioma Harboring Somatic BAP1 Mutations

IntroductionGenomic studies of malignant pleural mesothelioma (MPM) have recently identified frequent mutations in the BRCA-associated protein 1(BAP1) gene. In uveal melanoma and clear cell renal cell carcinoma, BAP1 mutations are associated with poor outcomes but their clinical significance in MPM is unknown. We therefore undertook this study to define the characteristics of patients whose MPM tumors harbor somatic BAP1 mutation and to examine the relationship between BAP1 mutation and survival.MethodsWe reviewed the charts of 121 patients with MPM tumors diagnosed between 1991 and 2009 tested for BAP1 mutation, and extracted the following information: age at diagnosis, sex, histology, stage, smoking status, asbestos exposure, family or personal history of malignancy, and treatment including surgery, chemotherapy, and radiation as well as survival status.ResultsTwenty-four of the 121 tumors (20%) harbored somatic BAP1 mutations. The percentage of current or former smokers among cases with BAP1 mutations was significantly higher than in BAP1 wild-type cases, (75% versus 42%; p = 0.006). However, the types of nucleotide substitutions in BAP1 did not suggest that this association was because of a causative role of smoking in BAP1 mutations. No other clinical feature was significantly different among those with and without BAP1 mutations in their MPM. There was also no difference in survival according to somatic BAP1 mutation status.ConclusionThere is no apparent distinct clinical phenotype for MPM with somatic BAP1 mutation. The significance of the more frequent history of smoking among patients with BAP1-mutated MPM warrants further study