Laser Microirradiation of Chinese Hamster Cells at Wavelength 365 nm

Cells of a V79 subline of the Chinese hamster were microirradiated at wavelength 365 nm in the presence of the psoralen derivative, trioxsalen. Microirradiation was accomplished by a pulsed argon laser microbeam either in anaphase or in interphase 3 hr after mitosis. Inhibition of clonal growth and formation of micronuclei at the first postirradiation mitosis were observed after microirradiation of anaphase chromosomes and of small parts of the interphase nucleus. Microirradiation of the cytoplasm beside the interphase nucleus or between the sets of chromosomes moving apart from each other in anaphase did not produce these effects. Anaphase experiments showed that only the daughter cell which received microirradiated chromatin exhibited an abnormal growth pattern. Most interestingly, shattering of the whole chromosome complement could be induced by microirradiation of small parts of the interphase nucleus and post-treatment with caffeine. Since microirradiation of chromatin in the absence of psoralen was not effective, we consider formation of psoralen photoadducts to nucleic acids in microirradiated chromatin to be the specific cause of the effects. We suggest that DNA photolesions in chromosome segments present in the microirradiated part of the nucleus can induce shattering of all the chromosomes in the microirradiated nucleus. Several possibilities are discussed to explain this unexpected finding

A Novel Approach to Understanding Functional Gait and Variable Walking Strategies in an Asymptomatic Low Back Pain Population

Meaningful gait assessment in individuals with low back pain (LBP) should involve prolonged, dynamic walking conditions with directional changes that resemble functional gait. However, previous studies have investigated less ecologically valid, short, steady-state walking paradigms. The purpose of this study was to compare spatiotemporal variables during figure eight walking between asymptomatic young adults with a history of LBP and back-healthy (BH) individuals. Fifty-nine young adults participated (age 22.4 ± 0.5 years, 36 with a history of LBP, asymptomatic at the time of data collection but reporting at least a one-year history of functionally limiting episodes of pain). Participants were instrumented with inertial sensors on the sternum, wrists, lumbar spine, and feet. Participants walked at self-selected speed for five minutes in a ten-meter figure eight pattern. Spatiotemporal gait characteristics across stride cycles were calculated using Mobility Lab software (APDM Inc). Group comparisons were conducted with independent samples t-tests/Mann-Whitney U tests. Effect sizes were calculated using Cohen’s d. Groups did not differ based on age, height, weight, body mass index (BMI), and typical physical activity (p \u3e 0.05 for all comparisons). Walking speed for the LBP group was less than the BH group (LBP = 1.13 m/s, BH = 1.24 m/s, p \u3c 0.001, d = 1.01). LBP individuals exhibited reduced cadence (LBP = 110.15, BH = 113.94, p = 0.026, d = 0.61) and longer duration of gait cycle (LBP = 1.10 s, BH = 1.06 s, p = 0.027, d = 0.62) than BH individuals. Additionally, LBP participants spent a greater percentage of their gait cycle in stance phase (LBP = 59.93%, BH = 58.72%, p = 0.003, d = 0.84) and in double support (LBP = 19.90%, BH = 17.50%, p = 0.002, d = 0.86). Despite being asymptomatic at the time of data collection, young adults with a history of LBP displayed conservative spatiotemporal gait characteristics during prolonged figure-eight walking in comparison to BH individuals. Ongoing research will determine if this gait strategy is more favorable for limiting the progression of LBP over time

Governamentalidade algorítmica e perspectivas de emancipação: o díspar como condição de individuação pela relação?

As novas possibilidades de modelização do real, a partir de algoritmos autodidatas, reordenam as práticas estatísticas modernas e participam da emergência de novas formas de controle. O desenvolvimento de uma governamentalidade algorítmica suscitaria a esperança de libertar-se da subjetividade e pensar os indivíduos pela relação, que se torna o objeto principal de rastreamento e determinação de algoritmos autodidatas. A centralidade da relação para esses modelos faz retornar propostas de filósofos como Simondon e Deleuze e Guattari, para quem a relação levaria a arranjos transindividuais e rizomáticos emancipadores. Apesar das possíveis aproximações, permanecem diferenças fundamentais, que dizem respeito ao papel da “diferença”, da disparidade e da “falha” na criação de novos mundos relacionais

Improving color reproduction accuracy of an OLED-based mobile display

For improving color reproduction accuracy of mobile displays, we recently developed a generic model for device-specific display characterization model that also accounts for the influence of illuminance from ambient light. In the present article, this MDCIM model (Mobile Display Characterization and Illumination Model) is applied to a Samsung Galaxy S4 display, representing OLED displays. The performance of the model was tested by determining the values of all model parameters using publicly available technical data only. We organized visual tests under various ambient illuminance levels from 600 to 3000 lux. Seven observers compared the color of displayed images with the color of physical samples. With the MDCIM method, the quality of the color match was shown to improve considerably as compared to using only device-independent encoding color space. On a five-point scale to quantify color reproduction accuracy, the MDCIM resulted in more than 1 unit improvement at 1000 lux illuminance. At lower and higher illuminance, the improvement was even larger. Color reproduction accuracy was found to be at least reasonable, according to the subjective assessment of visual observers, for more than 75% of the samples when using the MDCIM method, but only 20% or less when using the common device-independent encoding color space