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HP’s LaserJet 1320: A lung’s worst nightmare?
Laser printers get raked over the coals in an Australian air quality study

The laser printer has become a common staple in businesses and homes across America. The printers often have a higher initial cost then the throw-away inkjet printers available today, but the cost-per page for B&W printing is unmatched with laser technology.

An Australian researcher, however, has found that our fondness for laser printers comes at a risk. Research Queensland University of Technology physics Professor Lidia Morawska and her team — comprised of members from the Queensland Department of Public Works and The Cooperative Research Centre for Construction Innovation — have found that some printers can emit a high number of unhealthy toner particles into the air.

The particles, which can be inhaled into the lungs and cause respiratory problems, are potentially carcinogenic and could be as unhealthy as cigarette smoke.

According to the study, “The highest printer particle number emission rate found in the chamber study was 1.6 * 1011 particle min-1, which is close to the median value of submicrometer particle number emission rates for activities, such as cigarette smoking (1.91 * 1011 particle min-1), occurring in residential houses.”

“The high standard deviation of the average emission rates estimated in this study also indicates that the particle emission process and the behavior of individual printers are complex and that they are still far from being completely understood,” the study continues. “Many factors, such as printer model, printer age, cartridge model, and cartridge age may affect the particle emission process and all of these factors require further study.”

The research team tested 62 laser printer models from Canon, Hewlett-Packard, Ricoh and Toshiba. Of the laser printers tested 17 were shown to be “high particle emitters.”

Of the printers tested, HP’s LaserJet 1320 and 4250 models were shown to be serious offenders, while HP’s LaserJet 5 barely made a blip on the radar screen.

Hewlett-Packard issued a statement earlier in regards to the study’s findings. “Vigorous tests under standardized operating conditions are an integral part of HP’s research and development, and its strict quality-control procedures,” said the company in a statement to CNET News. “As part of these quality controls, HP assesses its LaserJet printing systems, original HP print cartridges and papers for dust release and possible material emissions to ensure compliance with applicable international health and safety requirements.”

Morawaska’s study will be published in the American Chemical Society’s Environmental Science & Technology (ES&T) journal.

Link | www.dailytech.com

This explains a lot of things …

Science Daily — Multitasking seems to come easier for some and is virtually impossible for others, however new research shows that it is difficult for all in the late night and early morning. Previous studies have shown that the time of day greatly affects human’s reaction time.*

This performance decrement is constantly found during the night with its’ lowest point in the early morning. This leads to the assumption that the time of day directly affects the speed of cognitive processing.

Daniel Bratzke at the University of Tuebingen wished to take these studies a bit further and figure out what makes our reaction time so slow during the wee hours. While many researchers have studied this, Bratzke focused on one of the three stages of human processing because he argues that measuring overall reaction time does not allow researchers to separate the effects of three different processing stages. Bratzke describes, for example, that the stage models of human performance assume at least three distinct processing stages: early perceptual, central decisional and late motor. He writes, “Given this widely accepted view, the question arises whether time of day affects all processing stages in general or one or more stages selectively.”

There is evidence that the circadian variations in reaction time are at least partly due to changes in two of the processing stages; in the early perceptual stage for example, it takes longer to detect and identify a visual stimulus if you are tired. Likewise, manual dexterity, grip strength, and tapping, which assess motor ability, are susceptible to our circadian rhythm, with a low point in the morning and peak in the late evening.

Bratzke wished to localize the time-of-day effects on processes that occur during the central decisional stage, such as decision-making. Along with his colleagues, he hypothesized that reaction time performance decrements during the night might be associated with slowing of this central processing stage. They refer to this as the central-slowing hypothesis.

Bratzke observed six subjects during 28 hours of constant wakefulness. During this time, the subjects performed various cognitive tasks every two hours. Bratzke used a dual-task performance test (psychological refractory period paradigm) to assess the duration of the central processing stage with two stimuli introduced at different times. The results provided evidence for a circadian modulation on reaction time with a constant decrement in the late evening while reaching it’s lowest point in the early morning. Importantly, dual-task interference increased in the night and early morning as well. Thus, central processing slowed down during the night, a result that supports the central-slowing hypothesis.

It is important to note that Bratzke monitored circadian phases through salivary melatonin concentration and body temperature. These biological markers of circadian phases corresponded with the decrement in reaction time, telling us that sleep deprivation was not the only moderator in the performance decrement.

These results build upon a recent study showing that even the well-practiced simple task of vehicle braking is subject to dual-task slowing. When watching the car brake in front of you while processing another stimulus concurrently the braking response can be markedly slowed down. The present results suggest that dual-task slowing as e.g. in this driving situation is influenced by the time of day with the most pronounced slowing in the early morning. Bratzke writes, “in addition to sleepiness, a combination of slowed reactions and impaired central efficiency might contribute to impaired driving performance and a higher risk for traffic accidents in the early morning.”

Bratzke completed this research with within the interdisciplinary network “ClockWORK” which is funded by the Gottlieb Daimler- und Karl Benz-Stiftung.

Link | www.sciencedaily.com

Years ago when Seinfeld was a new television show, Jerry Seinfeld was still a touring comic. At the time, I was hanging around clubs doing open mic nights and trying to learn the ropes. One night I was in the club where Seinfeld was working, and before he went on stage, I saw my chance. I had to ask Seinfeld if he had any tips for a young comic. What he told me was something that would benefit me a lifetime…
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Entrenar el cerebro con un programa de ‘brain-training’ específico puede ser mejor que hacerlo con los juegos clásicos de ordenador de cara a tratar de evitar el declive mental relacionado con la edad, informaron los científicos.

Pese a que las tiendas informáticas y de videojuegos han sido habitualmente bastión de adolescentes, .

Los juegos, de compañías como Nintendo y Mattel, están basados en estudios que muestran que con un poco de entrenamiento, los mayores pueden mejorar su potencial cerebral.

Un grupo de investigadores de Israel ha comprado cómo un programa de ‘brain-training’, MindFit, superaba a otro con muestras de juegos clásicos como el Tetris.

El estudio, financiado con una beca del fabricante de juegos CogniFit, contó con 121 voluntarios de más de 50 años que usaron el programa de entrenamiento MindFit o una muestra de juegos informáticos durante tres meses.

Los voluntarios se dividieron en dos grupos y se les dijo que iban a jugar con un programa informático y otro que era un proyecto piloto.

Ambos grupos se beneficiaron, pero el grupo que usó el MindFit mostró una mejora estadísticamente significativa en la memoria espacial a corto plazo, el aprendizaje espacial y la concentración.