Bacteria for the nineties

Staphylococcus aureus and Enterococci have gained prominence as the causes of wound infections during this decade. Methicillin-resistant Staphylococcus aureus (MRSA) became commonplace in the United States during the 1980s. In Canada, infections with MRSA have been increasing in frequency since 1995. MRSA develops resistance by producing an altered penicillin-binding protein, PBP 2a, coded for by the mecA gene. Vancomycin is the usual drug of choice. Recently, strains with intermediate resistance to vancomycin (VISA) have been isolated from patients in Japan and the United States. Interim guidelines for their control have been developed by the Centers for Disease Control. Enterococci have developed a resistance to a variety of antimicrobials during the past three decades, including beta-lactams and aminoglycosides. Recently, strains resistant to vancomycin (VRE) have been found in the United States and Canada. They are particularly difficult to treat, although some success has been achieved with experimental drugs. These microorganisms have the ability to escape control by antimicrobials almost as soon as they are developed. Thus, we must practice good infection control and reserve antimicrobials only for clear cases of infection if we are to prevent or delay the emergence of resistance.     

Phytochromes and cryptochromes in the entrainment of the Arabidopsis circadian clock

Circadian clocks are synchronized by environmental cues such as light. Photoreceptor-deficient Arabidopsis thaliana mutants were used to measure the effect of light fluence rate on circadian period in plants. Phytochrome B is the primary high-intensity red light photoreceptor for circadian control, and phytochrome A acts under low-intensity red light. Cryptochrome 1 and phytochrome A both act to transmit low-fluence blue light to the clock. Cryptochrome 1 mediates high-intensity blue light signals for period length control. The presence of cryptochromes in both plants and animals suggests that circadian input pathways have been conserved throughout evolution.     

Need for recovery from work: evaluating short-term effects of working hours,patterns and schedules

In this paper working hours, patterns and work schedules of employees were evaluated in terms of need for recovery from work. Self-administered questionnaire data from employees of the Maastricht Cohort Study on Fatigue at Work (n = 12,095) were used. Poisson regression analyses and multivariate logistic regression analyses revealed that higher working hours a day and working hours a week generally went together with more need for recovery from work. Overtime work was particularly associated with higher need for recovery from work in both genders. Both male and female three-shift or irregular shift workers had higher odds of elevated need for recovery compared to day workers. When additionally controlling for work-related factors, need for recovery levels among shift workers substantially lowered. This study clearly showed that working hours and schedules are associated with need for recovery from work, with different associations for men and women. Especially the associations between work schedules and need for recovery from work were very interrelated with other work-related factors. Future studies could further investigate the possibility that shift work might function as a proxy of other work-related factors that explain the different levels in need for recovery from work, or that job demands are perceived higher among shift workers and may therefore lead to more need for recovery from work.     

Resonance and nonresonant laser ionization of sputtered uranium atoms from thin films and single microparticles: evaluation of a combined system for particle trace analysis

The resonance and nonresonant laser ionization of uranium atoms sputtered from thin metal films and individual micrometer-size uranium oxide particles, respectively, was studied to evaluate a new setup for the analysis of actinide-containing micrometer-size particles. Experiments using nonresonant (193-nm) ionization of atoms and molecules sputtered from micrometer-size uranium oxide particles have shown that the uranium detection efficiencies for sputtered neutral atoms are approximately 2 orders of magnitude higher than for secondary ions. In uranium particles of 0.5-microm diameter, 6 x 10(6) atoms of 235U were easily detected and the isotopic ratio of 235U/238U = 0.0048 +/- 4.6% is in excellent agreement with the certified value. The use of two-color, two-step resonance ionization of the sputtered neutral uranium atoms from thin films was investigated. Several excitation schemes were tested, and a significant population of several low-lying metastable states after ion sputtering was observed. Autoionizing states for double-resonant ionization were determined, and the high selectivity of ionization schemes involving these autoionizing states was illustrated by comparing the flight-time distributions of different sputtered species obtained both by resonance and nonresonant multiphoton (355-nm) laser postionization. Ideally, the options for resonance as well as nonresonant ionization would be combined in a single setup, to obtain a large gain in sensitivity and selectivity. Thus, information about the main components as well as specific isotopic information of a trace element could be obtained from the same single particle.     

Gender differences in mediated communication: Women connect more than do men

Past research in gender differences in the overall Internet use has been contradictory. Some asserted men used it more than women, while others asserted there were no gender difference. Both camps concluded that men and women differed in their motivation and utilization of time spent online. The purpose of the present research was to take a contemporary look at these gender differences. Using an online survey, we asked participants about their experiences with multiple forms of mediated communication: social networking sites, e-mail, video calls, instant messaging, texting, and phone calls. Our results indicated that women, compared to men, are generally more frequent mediated communication users. Compared to men, women prefer and more frequently use text messaging, social media, and online video calls. These results suggest that the nature of mediated social interaction is changing.     

A 3-degree of freedom binary search pose estimation technique

This paper describes a novel, binary search pose estimation (BSPE) technique for poses constrained to 3 degrees of freedom (DOF). The technique requires three fiduciary marker points and operates by minimising the angular DOF through a binary search driven algorithm. The technique is less computationally intensive than the standard closed form solutions and quickly converges to a solution which can be verified if additional fiduciary points are available. Evaluation for the technique is presented through a comparison to pose from orthography and scaling with iterations (POSIT) using synthetic data and a real-world application, where the technique is used for pose estimation of a mobile robot with respect to a motor vehicle for inspection purposes.