The Histone Chaperone HIRA Is a Positive Regulator of Seed Germination

Histone chaperones regulate the flow and dynamics of histone variants and ensure their assembly into nucleosomal structures, thereby contributing to the repertoire of histone variants in specialized cells or tissues. To date, not much is known on the distribution of histone variants and their modifications in the dry seed embryo. Here, we bring evidence that genes encoding the replacement histone variant H3.3 are expressed in Arabidopsis dry seeds and that embryo chromatin is characterized by a low H3.1/H3.3 ratio. Loss of HISTONE REGULATOR A (HIRA), a histone chaperone responsible for H3.3 deposition, reduces cellular H3 levels and increases chromatin accessibility in dry seeds. These molecular differences are accompanied by increased seed dormancy in hira-1 mutant seeds. The loss of HIRA negatively affects seed germination even in the absence of HISTONE MONOUBIQUITINATION 1 or TRANSCRIPTION ELONGATION FACTOR II S, known to be required for seed dormancy. Finally, hira-1 mutant seeds show lower germination efficiency when aged under controlled deterioration conditions or when facing unfavorable environmental conditions such as high salinity. Altogether, our results reveal a dependency of dry seed chromatin organization on the replication-independent histone deposition pathway and show that HIRA contributes to modulating seed dormancy and vigor.     

Telecommunications standardization for the new millennium: ITU-T'sstrategies

After reviewing the environmental changes in telecommunications and the market trend toward global convergence, this article examines the evolution of the standards-making process, especially from an ITU's perspective. Projects on IP-based networks and their interworking with the telecommunication networks and MEDIA-COM 2004 are then treated from the viewpoint of the final convergence toward a worldwide global information infrastructure     

Effects of smoking bans on passive smoking exposure at work and at home. The European Community respiratory health survey

This longitudinal study investigated whether smoking bans influence passive smoking at work and/or at home in the same subjects. Passive smoking at work and/or at home was investigated in random population samples (European Community Respiratory Health Survey) in 1990‐1995, with follow‐up interviews in 1998‐2003 and 2010‐2014. National smoking bans were classified as partial (restricted to public workplaces) or global (extended to private workplaces). Multivariable analysis was accomplished by three‐level logistic regression models, where level‐1, level‐2, and level‐3 units were, respectively, questionnaire responses, subjects, and centers. Passive smoking at work was reported by 31.9% in 1990‐1995, 17.5% in 1998‐2003, and 2.5% in 2010‐2014. Concurrently, passive smoking at home decreased from 28.9% to 18.2% and 8.8%. When controlling for sex, age, education, smoking status, and ECHRS wave, the odds of passive smoking at work was markedly reduced after global smoking bans (OR = 0.45, 95% CI 0.25‐0.81), particularly among non‐smokers, while the protective effect of global smoking bans on passive smoking at home was only detected in non‐smokers. Smoking bans both in public and private workplaces were effective in reducing passive smoking at work in Europe. However, given the inefficacy of smoking bans in current smokers’ dwellings, better strategies are needed to avoid smoking indoors.     

Predictors for Reporting of Dietary Assessment Methods in Food-based Randomized Controlled Trials over a Ten-year Period

The importance of monitoring dietary intake within a randomized controlled trial becomes vital to justification of the study outcomes when the study is food-based. A systematic literature review was conducted to determine how dietary assessment methods used to monitor dietary intake are reported and whether assisted technologies are used in conducting such assessments. OVID and ScienceDirect databases 2000–2010 were searched for food-based, parallel, randomized controlled trials conducted with humans using the search terms “clinical trial,” “diet$ intervention” AND “diet$ assessment,” “diet$ method$,” “intake,” “diet history,” “food record,” “food frequency questionnaire,” “FFQ,” “food diary,” “24-hour recall.” A total of 1364 abstracts were reviewed and 243 studies identified. The size of the study and country of origin appear to be the two most common predictors of reporting both the dietary assessment method and details of the form of assessment. The journal in which the study is published has no impact. Information technology use may increase in the future allowing other methods and forms of dietary assessment to be used efficiently.     

Superconducting YBa2Cu3O7?δ Thin Film Detectors for Picosecond THz Pulses

Ultra-fast THz detectors from superconducting YBa₂Cu₃O_7?δ (YBCO) thin films were developed to monitor picosecond THz pulses. YBCO thin films were optimized by the introduction of CeO₂ and PrBaCuO buffer layers. The transition temperature of 10 nm thick films reaches 79 K. A 15 nm thick YBCO microbridge (transition temperature—83 K, critical current density at 77 K—2.4 MA/cm²) embedded in a planar log-spiral antenna was used to detect pulsed THz radiation of the ANKA storage ring. First time resolved measurements of the multi-bunch filling pattern are presented.     

The effects of job insecurity on employee safety outcomes: Cross-sectional and longitudinal explorations.

Job insecurity research has focused primarily on attitudinal (e.g., job satisfaction), behavioral (e.g., employee turnover), and health outcomes. Moreover, research in the area of workplace safety has largely focused on ergonomic factors and personnel selection and training as primary antecedents of safety. Two cross-sectional structural equational modeling analyses and 1 longitudinal regression analysis of 237 food-processing plant employees unite these 2 disparate areas of research by exploring the relatively uncharted relationship between job insecurity and safety outcomes. Results indicate that employees who report high perceptions of job insecurity exhibit decreased safety motivation and compliance, which in turn are related to higher levels of workplace injuries and accidents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modulation of protein kinase C by taurolithocholic acid in isolated rat hepatocytes

Misalignment of repeated sequences during DNA replication can lead to deletions or duplications in genomic DNA. In Escherichia coli, such genetic rearrangements can occur at high frequencies, independent of the RecA-homologous recombination protein, and are sometimes associated with sister chromosome exchange (SCE). Two mechanisms for RecA-independent genetic rearrangements have been proposed: simple replication misalignment of the nascent strand and its template and SCE-associated misalignment involving both nascent strands. We examined the influence of the 3' exonuclease of DNA polymerase III and exonuclease I on deletion via these mechanisms in vivo. Because mutations in these exonucleases stimulate tandem repeat deletion, we conclude that displaced 3' ends are a common intermediate in both mechanisms of slipped misalignments. Our results also confirm the notion that two distinct mechanisms contribute to slipped misalignments: simple replication misalignment events are sensitive to DNA polymerase III exonuclease, whereas SCE-associated events are sensitive to exonuclease I. If heterologies are present between repeated sequences, the mismatch repair system dependent on MutS and MutH aborts potential deletion events via both mechanisms. Our results suggest that simple slipped misalignment and SCE-associated misalignment intermediates are similarly susceptible to destruction by the mismatch repair system.     

Epilepsia partialis continua: a new manifestation of anti-Hu-associated paraneoplastic encephalomyelitis

We report on 3 anti-Hu-positive patients who presented with clinical and electroencephalographic (EEG) features of epilepsia partialis continua (EPC). Two of the patients had an associated small cell carcinoma. Magnetic resonance imaging (MRI) disclosed a hyperintense nonenhancing focal lesion in T2-weighted images in the sensorimotor area in 2 patients. Histopathological analysis of the lesion revealed inflammatory infiltrates and neuronal cell loss. In the patient who had a postmortem study, these neuropathological changes were not observed in other areas of the nervous system. This study emphasizes that the possibility of an anti-Hu-associated paraneoplastic disorder must be considered in patients with cortical encephalitis presenting with EPC when a brain tumor can be excluded.     

Application of Ni:SiO2 nanocomposite to control the carbon deposition on the carbon dioxide reforming of methane

Stable Ni nanoparticles embedded in a mesoporous silica material were used as catalysts for the conversion of methane into synthesis gas. This catalyst has the singular properties of controlling the carbon deposition and deactivation of active sites. A comparative study of our nanocomposites with conventional catalysts showed that impregnation material presented a preferential encapsulation and growth of carbon nanotubes on the metal surface. The impregnated catalyst showed a higher tendency for carbon nanotube and whiskers formation.