Microelectrophoresis of selected mineral particles

Particle mobilities of ilmenite, labradorite plagioclase, enstatite pyroxene, and olivine were measured with a Rank microelectrophoresis system to evaluate indicated mineral separability. Sodium bicarbonate buffer suspension media with and without additives (0.0001 M DTAB and 5 percent v/v ethylene glycol) were used to determine differential adsorption by mineral particles and modification of relative mobilities. Good separability between some minerals was indicated; additives did not enhance separability

Response of silicon solar cell to pulsed laser illumination

The response of silicon solar cell(s) to pulsed laser illumination is discussed. The motivation was due to the interest of Earth to space/Moon power beaming applications. When this work began, it was not known if solar cells would respond to laser light with pulse lengths in the nanosecond range and a repetition frequency in the kHz range. This is because the laser pulse would be shorter than the minority carrier lifetime of silicon. A 20-nanosecond (ns) full width half max (FWHM) pulse from an aluminum-gallium/arsenide (Al-Ga-As) diode laser was used to illuminate silicon solar cells at a wavelength of 885 nanometers (nm). Using a high-speed digital oscilloscope, the response of the solar cells to individual pulses across various resistive loads was observed and recorded

Vacuum Strength of Two Candidate Glasses for a Space Observatory

The strengths of two candidate glass types for use in a space observatory were measured. Samples of ultra-low expansion glass (ULE) and borosilicate (Pyrex) were tested in air and in vacuum at room temperature (20 C) and in vacuum after being heated to 200 C. Both glasses tested in vacuum showed an increase in strength over those tested in air. However, there was no statistical difference between the strength of samples tested in vacuum at room temperature and those tested in vacuum after heating to 200 C

Integration of AI-2 Based Cell-Cell Signaling with Metabolic Cues in Escherichia coli

Citation: Mitra, A., Herren, C. D., Patel, I. R., Coleman, A., & Mukhopadhyay, S. (2016). Integration of AI-2 Based Cell-Cell Signaling with Metabolic Cues in Escherichia coli. Plos One, 11(6), 19. doi:10.1371/journal.pone.0157532The quorum sensing molecule Autoinducer-2 (AI-2) is generated as a byproduct of activated methyl cycle by the action of LuxS in Escherichia coli. AI-2 is synthesized, released and later internalized in a cell-density dependent manner. Here, by mutational analysis of the genes, uvrY and csrA, we describe a regulatory circuit of accumulation and uptake of AI-2. We constructed a single-copy chromosomal luxS-lacZ fusion in a luxS (+) merodiploid strain and evaluated its relative expression in uvrY and csrA mutants. At the entry of stationary phase, the expression of the fusion and AI-2 accumulation was positively regulated by uvrY and negatively regulated by csrA respectively. A deletion of csrA altered message stability of the luxS transcript and CsrA protein exhibited weak binding to 5' luxS regulatory region. DNA protein interaction and chromatin immunoprecipitation analysis confirmed direct interaction of UvrY with the luxS promoter. Additionally, reduced expression of the fusion in hfq deletion mutant suggested involvement of small RNA interactions in luxS regulation. In contrast, the expression of lsrA operon involved in AI-2 uptake, is negatively regulated by uvrY and positively by csrA in a cell-density dependent manner. The dual role of csrA in AI-2 synthesis and uptake suggested a regulatory crosstalk of cell signaling with carbon regulation in Escherichia coli. We found that the cAMP-CRP mediated catabolite repression of luxS expression was uvrY dependent. This study suggests that luxS expression is complex and regulated at the level of transcription and translation. The multifactorial regulation supports the notion that cell-cell communication requires interaction and integration of multiple metabolic signals

Muon spin relaxation study of the magnetism in unilluminated Prussian Blue analogue photomagnets

We present longitudinal field muon spin relaxation ($\mu$SR) measurements in the unilluminated state of the photo-sensitive molecular magnetic Co-Fe Prussian blue analogues M$_{1-2x}$Co$_{1+x}$[Fe(CN)$_6$]$\cdot z$ H$_2$O, where M=K and Rb with $x=0.4$ and $\simeq 0.17$, respectively. These results are compared to those obtained in the $x=0.5$ stoichiometric limit, Co$_{1.5}$[Fe(CN)$_6$]$\cdot 6$ H$_2$O, which is not photo-sensitive. We find evidence for correlation between the range of magnetic ordering and the value of $x$ in the unilluminated state which can be explained using a site percolation model.Comment: 7 pages, 12 figure

Age- and Gender-Specific Normative Data of Grip and Pinch Strength in a Healthy Adult Swiss Population

Assessment of hand strength is used in a wide range of clinical settings especially during treatment of diseases affecting the function of the hand. This investigation aimed to determine age- and gender-specific reference values for grip and pinch strength in a normal Swiss population with special regard to old and very old subjects as well as to different levels of occupational demand. Hand strength data were collected using a Jamar dynamometer and a pinch gauge with standard testing position, protocol and instructions. Analysis of the data from 1023 tested subjects between 18 and 96 years revealed a curvilinear relationship of grip and pinch strength to age, a correlation to height, weight and significant differences between occupational groups. Hand strength values differed significantly from those of other populations, confirming the thesis that applying normative data internationally is questionable. Age- and gender-specific reference values for grip and pinch strength are presented

Skilling up for training : a feasibility study investigating acute effects of stochastic resonance whole-body vibration on postural control of older adults

The present pilot study investigated the feasibility of applying a single bout stochastic resonance whole-body vibration in deconditioned elderly individuals and the effects on static and dynamic balance and reaction time. We report the results of a non-blinded randomized control trial with a pre-test/post-test design. Twenty elderly individuals were randomized into either single bout stochastic resonance whole-body vibration (SR-WBV) (n=10, frequency 5 Hz, Noise 4) or control (n=10). SR-WBV received 5 sets of 1 min stochastic whole-body vibration (5 Hz, Noise 4: vibration with a randomly varying frequency, 1=low, 4=high) with 1 min rest in between. The control group rested for 10 min without any intervention. Functional reach test (FRT), semi-tandem stand (STS), Expanded Timed Get Up-and-Go Test (ETGUG), single task- (ST) and dual task walking time (DT), chair rising (CR), and foot (RTF) and hand reaction time (RTH) were measured before and after the intervention. Within- and between group differences were analyzed using repeated measures. In order to assess the meaningfulness of pre-training to post-training changes, the effect size (ES) was calculated according to Cohen’s d. All participants in the study accepted and adhered to the WBV session and performed scheduled follow-up measurements. There were no adverse events. Change values for dynamic balance showed a strong trend towards improvement for FRT of about 4.5% (ES=0.52, P=0.161). Change values for RTF (5.9%; ES=0.55; P =0.169) showed a trend towards improvement in the SR-WBV only. The results suggest that stochastic resonance WBV is both safe and well accepted by elderly individuals in assisted living institutions, and might have beneficial effects on balance in these adults. Further research is warranted to determine whether this device might be of use in the skilling-up phase of an exercise program when training is initiated in strongly deconditioned and/or frail elderly. The new training protocol is expected to allow for safe skilling-up training of deconditioned older adults in assisted living institutions

Multidimensional Performance of Farming Approaches

Fil: Garibaldi, Lucas Alejandro. Universidad Nacional de Río Negro. Sede Andina; Argentina.Fil: Gemmill Herren, Barbara. World Agroforestry Centre; Kenya.Fil: D’Annolfo, Raffaele. Università Cattolica del Sacro Cuore; Italia.Fil: Graeub, Benjamin E. Biovision Foundation for Ecological Development y Ricolab; Suiza.Fil: Cunningham, Saul A. Australian National University; Australia.Fil: Breeze, Thomas D. University of Reading; UK.Fil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.The letter by Mehrabi et al. [1] provides interesting insights regarding the scientific framework and attitudes needed to support farming approaches for greater biodiversity, livelihoods, and food security. In general, we do not see a dichotomy between our point of view [2] and that put forward by Mehrabi et al. [1]. We share their view that the different farming systems we have described do not form distinct, non-overlapping categories. We do not seek to promote a binary choice between conventional and alternative farming

Investigation Into Radiation-Induced Compaction of Zerodur (trademark)

Zerodur is a low coefficient of thermal expansion glass-ceramic material. This property makes Zerodur an excellent material for high precision optical substrates. Functioning as a high precision optical substrate, a material must be dimensionally stable in the system operating environment. Published data indicate that Zerodur is dimensionally unstable when exposed to large doses of ionizing radiation. The dimensional instability is discussed as an increase in Zerodur density. This increase in density is described as a compaction. Experimental data showing proton-induced compaction of Zerodur is presented. The dependence of compaction on proton dose was determined to be a power law relationship