Muon decay in a linearly polarized laser field

In a previous paper, we showed that the decay rate of a muon is only slightly affected by the presence of a circularly polarized laser and we gave an analytic expression for the correction. In this paper, we present the analytical result for the case of a linearly polarized laser. Again the effect of the laser is small.Comment: 6 pages, no figure

In vitro effects of salinity and algae genera on the Rotifer (Brachionus plicatilis Muller 1786)

The marine rotifer Brachionus plicatilis is extensively used as a major live food in fish larvae culture all over the world. In the present study an attempt was made to find out the optimum salinity and feeding conditions for growth of the rotifer B. plicatilis. The rotifer was cultured using Batch culture method at four salinities ranges (20, 25, 30 and 35ppt) and was fed with 3 species of microalgae including, Nannochloropsis oculata, Isochrysis galbana and Chlorella sp. The difference between salinity was not significant (P>0.05) but there was a significant difference between the food types (P<0.05). In all of the experiments, the combined effect of salinity and algal type on rotifer growth were significant (P<0.05). The best result was observed in the experiment conducted at 35ppt salinity using N. oculata as the main food (378 ind/ml)

New advancements in charge-coupled device technology: sub-electron noise and 4096x4096 pixel CCDs

This paper reports on two new advancements in CCD technology. The first area of development has produced a special purpose CCD designed for ultra low-signal level imaging and spectroscopy applications that require sub-electron read noise floors. A nondestructive output circuit operating near its 1/f noise regime is clocked in a special manner to read a single pixel multiple times. Off-chip electronics average the multiple values, reducing the random noise by the square-root of the number of samples taken. Noise floors below 0.5 electrons rms are reported. The second development involves the design and performance of a high resolution imager of 4096 x 4096 pixels, the largest CCD manufactured in terms of pixel count. The device utilizes a 7.5-micron pixel fabricated with three-level poly-silicon to achieve high yield

Mars Science Laboratory Engineering Cameras

NASA's Mars Science Laboratory (MSL) Rover, which launched to Mars in 2011, is equipped with a set of 12 engineering cameras. These cameras are build-to-print copies of the Mars Exploration Rover (MER) cameras, which were sent to Mars in 2003. The engineering cameras weigh less than 300 grams each and use less than 3 W of power. Images returned from the engineering cameras are used to navigate the rover on the Martian surface, deploy the rover robotic arm, and ingest samples into the rover sample processing system. The navigation cameras (Navcams) are mounted to a pan/tilt mast and have a 45-degree square field of view (FOV) with a pixel scale of 0.82 mrad/pixel. The hazard avoidance cameras (Haz - cams) are body-mounted to the rover chassis in the front and rear of the vehicle and have a 124-degree square FOV with a pixel scale of 2.1 mrad/pixel. All of the cameras utilize a frame-transfer CCD (charge-coupled device) with a 1024x1024 imaging region and red/near IR bandpass filters centered at 650 nm. The MSL engineering cameras are grouped into two sets of six: one set of cameras is connected to rover computer A and the other set is connected to rover computer B. The MSL rover carries 8 Hazcams and 4 Navcams

Low-Resolution Imaging Spectrometer for the Keck Telescope

The Low Resolution Imaging Spectrometer is designed for use at the Cassegrain focus of the Keck 10-m telescope. It provides the capability of acquiring low resolution (R equals 1000 to 5000) digital spectra, as well as 6 X 8 arc-minute moderately high spatial resolution (4.65 pixels/arc-second) direct images. Spectroscopy can be carried out with single slits which are 3 arc-minutes long. In addition punched multi-slits can also be employed which allow for the acquisition of at least forty spectra simultaneously. Since the instrument is designed to be as efficient as possible, it is a double spectrograph, with a dichroic splitting the blue and red light into separate optical paths after the collimator. Only the red side has been constructed thus far. With a 2048 by 2048 thinned Tektronix CCD as the detector the total efficiency of the red side at the peak of the grating blaze is predicted to be nearly 40%. Results of the commissioning observing runs will be described

The role of chemical structure on the magnetic and electronic properties of Co2FeAl0.5Si0.5/Si(111) interface

We show that Co2FeAl0.5Si0.5 film deposited on Si(111) has a single crystal structure and twin related epitaxial relationship with the substrate. Sub-nanometer electron energy loss spectroscopy shows that in a narrow interface region there is a mutual inter-diffusion dominated by Si and Co. Atomic resolution aberration-corrected scanning transmission electron microscopy reveals that the film has B2 ordering. The film lattice structure is unaltered even at the interface due to the substitu- tional nature of the intermixing. First-principles calculations performed using structural models based on the aberration corrected electron microscopy show that the increased Si incorporation in the film leads to a gradual decrease of the magnetic moment as well as significant spin-polarization reduction. These effects can have significant detrimental role on the spin injection from the Co2FeAl0.5Si0.5 film into the Si substrate, besides the structural integrity of this junction

Magnetic and structural depth profiles of Heusler alloy Co2FeAl0.5Si0.5 epitaxial films on Si(1 1 1)

The depth-resolved chemical structure and magnetic moment of Co2FeAl0.5Si0.5, thin films grown on Si(1 1 1) have been determined using x-ray and polarized neutron reflectometry. Bulk-like magnetization is retained across the majority of the film, but reduced moments are observed within 45˚A of the surface and in a 25˚A substrate-interface region. The reduced moment is related to compositional changes due to oxidation and diffusion, which are further quantified by elemental profiling using electron microscopy with electron energy loss spectroscopy. The accuracy of structural and magnetic depth-profiles obtained from simultaneous modeling is discussed using different approaches with different degree of constraints on the parameters. Our approach illustrates the challenges in fitting reflectometry data from these multi-component quaternary Heusler alloy thin films

Immunohistochemical analysis of the mechanistic target of rapamycin and hypoxia signalling pathways in basal cell carcinoma and trichoepithelioma

Background: Basal cell carcinoma (BCC) is the most common cancer in Caucasians. Trichoepithelioma (TE) is a benign neoplasm that strongly resembles BCC. Both are hair follicle (HF) tumours. HFs are hypoxic microenvironments, therefore we hypothesized that hypoxia-induced signalling pathways could be involved in BCC and TE as they are in other human malignancies. Hypoxia-inducible factor 1 (HIF1) and mechanistic/mammalian target of rapamycin (mTOR) are key players in these pathways. Objectives: To determine whether HIF1/mTOR signalling is involved in BCC and TE. Methods: We used immunohistochemical staining of formalin-fixed paraffin-embedded BCC (n = 45) and TE (n = 35) samples to assess activity of HIF1, mTORC1 and their most important target genes. The percentage positive tumour cells was assessed manually in a semi-quantitative manner and categorized (0%, 80%). Results: Among 45 BCC and 35 TE examined, expression levels were respectively 81% and 57% (BNIP3), 73% and 75% (CAIX), 79% and 86% (GLUT1), 50% and 19% (HIF1 alpha), 89% and 88% (pAKT), 55% and 61% (pS6), 15% and 25% (pMTOR), 44% and 63% (PHD2) and 44% and 49% (VEGF-A). CAIX, Glut1 and PHD2 expression levels were significantly higher in TE when only samples with at least 80% expression were included. Conclusions: HIF and mTORC1 signalling seems active in both BCC and TE. There are no appreciable differences between the two with respect to pathway activity. At this moment immunohistochemical analyses of HIF, mTORC1 and their target genes does not provide a reliable diagnostic tool for the discrimination of BCC and TE

The Influence of Maternal Body Mass Index and Physical Activity on Select Cardiovascular Risk Factors of Preadolescent Hispanic Children

Background. Maternal obesity and physical inactivity have been identified as correlates of overweight and obesity and physical inactivity in older preadolescents; however, no study has explored this relationship in Hispanic preadolescents. Furthermore, the relation between maternal physical activity (PA) and blood pressure (BP) in Hispanic preadolescents has not been examined. Purpose. This study aimed to assess the associations between Hispanic mothers’ PA and body mass index (BMI) and their preadolescents’ PA, screen time, BP, and BMI. Methods. Data of 118 mother-child (aged 2–10 years) dyads enrolled in a crosssectional study of metabolic syndrome in Hispanic preadolescents at a community health center in Johnson City, TN were used. Parent and child questionnaires were used to ascertain mothers’ BMI and PA and preadolescents’ PA and screen time