volume 117 | number 3 | March 2009 • Environmental Health Perspectives Recently, Time magazine published an article titled “The Year in Medicine: From A to Z” (Park et al. 2008). The letter “B” was represented by the controversy over bisphenol A, a ubiquitous chemical used in polycarbonate and polyvinyl chloride plastics and epoxy resins and found in the urine of > 90% of Americans. The debate ...

program prior to designing and conducting toxicology studies. The purpose of the research concept document is to outline the general elements of a research program that would address the specific public health concerns that prompted the nomination of the substance or issue for study. It may also encompass substance-specific studies that address larger public health issues or topics in toxicolog...

Nowadays, due to the exponential and continuous expansion of new paradigms such as Internet Things (IoT), Vehicles (IoV) 6G, world is witnessing a tremendous sharp increase network traffic. In large-scale, heterogeneous, complex networks, volume transferred data, big considered challenge causing different networking inefficiencies. To overcome these challenges, various techniques are introduced...

Clock synchronization is an important and complex task in distributed systems. The Network Time Protocol NTP is a protocol created to build and maintain the synchronization of computer clocks with the world real time. To do so, the NTP implements a dynamic logical network, presenting characteristics of a peer-to-peer network, which keeps itself self-organized, from the initial insertion of the ...

Quantifying the effect of vital resources on transcription (TX) and translation (TL) helps to understand the degree to which the concentration of each resource must be regulated for achieving homeostasis. Utilizing the synthetic TX-TL system, we study the impact of nucleotide triphosphates (NTPs) and magnesium (Mg2þ) on gene expression. Recent observations of the counter-intuitive phenomenon of...

This paper describes the analysis, implementation and performance of a new algorithm engineered to discipline a computer clock to a source of standard time, such as a GPS receiver or another computer synchronized to such a source. The algorithm is intended for the Network Time Protocol (NTP), which is in widespread use to synchronize computer clocks in the global Internet, or with another funct...

One-way delay (OWD) between end hosts has important implications for Internet applications, protocols, and measurement-based analyses. We describe a new approach for identifying OWDs via passive measurement of Network Time Protocol (NTP) traffic. NTP traffic offers the opportunity to measure OWDs accurately and continuously from hosts throughout the Internet. Based on detailed examination of NT...

BACKGROUND Indonesia has a high tuberculosis (TB) prevalence and a large private health sector. OBJECTIVES To explore the potential of private practitioners (PP) in TB control in Jogjakarta by assessing their load of TB suspects and case-management practices. METHODS We conducted a cross-sectional telephone survey of a random sample of 164 PP, weighted to the local proportions of specialist...

There is a gap between the theory and practice of distributed systems in terms of the use of time. The theory of distributed systems shunned the notion of time, and introduced “causality tracking” as a clean abstraction to reason about concurrency. The practical systems employed physical time (NTP) information but in a best effort manner due to the difficulty of achieving tight clock synchroniz...