Theoretical progress in understanding the dynamics of spreading processes on graphs suggests the existence of an epidemic threshold below which no epidemics form and above which epidemics spread to a significant fraction of the graph. We have observed information cascades on the social media site Digg that spread fast enough for one initial spreader to infect hundreds of people, yet end up affe...

Benchmark dose (BMD) modeling has been touted as a more accu­ rate method for conducting chemical risk assessments. In this issue of EHP, a team of researchers applied BMD modeling to hundreds of chemicals whose health effects are already known in an effort to optimize the approach. To calculate the highest safe oral dose of a noncarcinogenic chem­ ical, regulators must first estimate the point...

An expression for Fisher’s observed information matrix is given under type I censoring for any location-scale distribution under mild requirements. It is illustrated on a data set which has been analyzed by several authors.

In auditory statistical learning, children are sensitive to the transitional structure of their language environment. Variability and stability of utterances in the language environment are important properties of statistical learning but are currently understudied across laboratory and naturalistic research contexts. In this study, we quantify variability and stability in the language environm...

Introduction: Nowadays, a significant number of children with acute leukemia can be cured. Iron overload, related to blood transfusions and its long-term complications, remains problem. Elevated ferritin concentration is often observed in this group. The aim study was evaluate the prognostic value serum on outcomes treated for leukemia. Material: We studied 71 patients lymphoblastic (ALL) or my...

SETTING Standardised tuberculosis (TB) treatment through directly observed therapy (DOT) is available in South Africa, but the level of adherence to standardised TB treatment and its impact on treatment outcomes is unknown. OBJECTIVES To describe adherence to standardised TB treatment and provision of DOT, and analyse its impact on treatment outcome. METHODS We utilised data collected for a...

Matrix factorization has found incredible success and widespread application as a collaborative filtering based approach to recommendations. Unfortunately, incorporating additional sources of evidence, especially ones that are incomplete and noisy, is quite difficult to achieve in such models, however, is often crucial for obtaining further gains in accuracy. For example, additional information...

Hormesis, a dose-response relationship phenomenon characterized by low-dose stimulation and high-dose inhibition, has been frequently observed in properly designed studies and is broadly generalizable as being independent of chemical/physical agent, biological model, and endpoint measured. This under-recognized and -appreciated concept has the potential to profoundly change toxicology and its r...

BACKGROUND The U.S. National Toxicology Program (NTP) cancer bioassay database provides an opportunity to compare both existing and new approaches to determining points of departure (PoDs) for establishing reference doses (RfDs). OBJECTIVES The aims of this study were a) to investigate the risk associated with the traditional PoD used in human health risk assessment [the no observed adverse e...

BACKGROUND Directly observed therapy (DOT), as recommended by the World Health Organization, is used in many countries to deliver tuberculosis (TB) treatment. The effectiveness of community-based (CB DOT) versus clinic DOT has not been adequately assessed to date. We compared TB treatment outcomes of CB DOT (delivered by community health workers or community volunteers), with those achieved thr...