Inhibition of DNA replication with hydroxyurea during thymine starvation of Escherichia coli shows that active DNA synthesis is not required for thymineless death (TLD). Hydroxyurea experiments and thymine starvation of lexA3 and uvrA DNA repair mutants rule out unbalanced growth, the SOS response, and nucleotide excision repair as explanations for TLD.

BACKGROUND Parasympathetic pulmonary nerves release acetylcholine that induces smooth muscle constriction. Disruption of parasympathetic pulmonary nerves improves lung function and COPD symptoms. AIMS To evaluate 'targeted lung denervation' (TLD), a novel bronchoscopic therapy based on ablation of parasympathetic pulmonary nerves surrounding the main bronchi, as a potential therapy for COPD. ...

Context: Test-Driven development (TDD) is a software development approach where test cases are written before actual development of the code in iterative cycles. TDD has gained attention of many software practitioners during the last decade since it has suggested several benefits in the software development process. However, empirical evidence of its dominance in terms of internal code quality,...

INTRODUCTION The angular dependency of response for TLD cards may cause deviation from its true value on the results of environmental dosimetry, since TLDs may be exposed to radiation at different angles of incidence from the surrounding area. OBJECTIVE A 3D setting of TLD cards has been calibrated isotropically in a standard radiation field to evaluate the improvement of the accuracy of meas...

Several national and international organizations have developed various types and levels of external audits for radiotherapy dosimetry, either based on on-site review visits or using mailed dosimetry systems. Three major TLD (thermoluminescent dosimetry) networks make available postal dose audits to a large number of radiotherapy centres on a regular basis. These are the IAEA/WHO TLD postal dos...

In 1954, Cohen and Barner discovered that a thymine auxotrophic (thyA) mutant of Escherichia coli undergoes cell death in response to thymine starvation. This phenomenon, called thymineless death (TLD), has also been found in many other organisms, including prokaryotes and eukaryotes. Though TLD has been studied intensively, its molecular mechanism has not yet been explained. Previously we repo...

During early Drosophila embryogenesis, several zygotic gene products act to establish a posttranscriptional activity gradient of the morphogen DPP. Among these molecules, Tolloid, a putative metalloprotease related to BMP-1, enhances DPP function, while SOG, an ortholog of the Xenopus organizer Chordin, inhibits DPP function. Using epistasis tests and a Xenopus secondary axis induction assay, w...

The lack of privacy in DNS and DNSSEC is a problem that has only recently begun to see widespread attention by the Internet and research communities, and the solutions proposed so far only look at a narrow slice of the design space. In this paper we investigate a new approach for a privacy-preserving DNS mechanism that hides query information from root name servers and TLD registries. Our archi...