The nature of 1WGA J1958.2+3232: a new intermediate polar

We present low and intermediate resolution spectroscopy of the optical counterpart to the recently discovered pulsating X-ray source 1WGA J1958.2+3232. The presence of strong HI , HeI and HeII emission lines together with the absence of absorption features rules out the possibility that the object is a massive star, as had recently been suggested. The observed X-ray and optical characteristics are consistent with the object being an intermediate polar. The double-peaked structure of the emission lines indicates that an accretion disc is present

Glycosylation pattern of brush border-associated glycoproteins in enterocyte-like cells: involvement of complex-type N-glycans in apical trafficking

We have previously reported that galectin-4, a tandem repeat-type galectin, regulates the raft-dependent delivery of glycoproteins to the apical brush border membrane of enterocyte-like HT-29 cells. N-Acetyllactosamine-containing glycans, known as galectin ligands, were found enriched in detergent-resistant membranes. Here, we analyzed the potential contribution of N-and/ or O-glycans in this mechanism. Structural studies were carried out on the brush border membrane-enriched fraction using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and nano-ESI-QTOF-MS/MS. The pattern of N-glycans was very heterogeneous, with the presence of high mannose- and hybrid-type glycans as well as a multitude of complex-type glycans. In contrast, the pattern of O-glycans was very simple with the presence of two major core type 1 O-glycans, sialylated and bisialylated T-antigen structures {[}Neu5Ac alpha 2-3Gal beta 1-3GalNAc-ol and Neu5Ac alpha 2-3Gal beta 1 -3(Neu5Ac alpha 2-6)GalNAc-ol]. Thus, N-glycans rather than O-glycans contain the N-acetyllactosamine recognition signals for the lipid raft-based galectin-4-dependent apical delivery. In the presence of 1-deoxymannojirimycin, a drug which inhibits the generation of hybrid-type or complex type N-glycans, the extensively O-glycosylated mucin-like MUC1 glycoprotein was not delivered to the apical brush border but accumulated inside the cells. Altogether, our data demonstrate the crucial role of complex N-glycans in the galectin-4-dependent delivery of glycoproteins to the apical brush border membrane of enterocytic HT-29 cells

Compact and explicit physical model for lateral metal-oxide-semiconductor field-effect transistor with nanoelectromechanical system based resonant gate

We propose a simple analytical model of a metal-oxide-semiconductor field-effect transistor with a lateral resonant gate based on the coupled electromechanical equations, which are self-consistently solved in time. All charge densities according to the mechanical oscillations are evaluated. The only input parameters are the physical characteristics of the device. No extra mathematical parameters are used to fit the experimental results. Theoretical results are in good agreement with the experimental data in static and dynamic operation. Our model is comprehensive and may be suitable for any electromechanical device based on the field-effect transduction

Monolithic integration of Giant Magnetoresistance (GMR) devices onto standard processed CMOS dies

Giant Magnetoresistance (GMR) based technology is nowadays the preferred option for low magnetic fields sensing in disciplines such as biotechnology or microelectronics. Their compatibility with standard CMOS processes is currently investigated as a key point for the development of novel applications, requiring compact electronic readout. In this paper, such compatibility has been experimentally studied with two particular non-dedicated CMOS standards: 0.35 μm from AMS (Austria MicroSystems) and 2.5 μm from CNM (Centre Nacional de Microelectrònica, Barcelona) as representative examples. GMR test devices have been designed and fabricated onto processed chips from both technologies. In order to evaluate so obtained devices, an extended characterization has been carried out including DC magnetic measurements and noise analysis. Moreover, a 2D-FEM (Finite Element Method) model, including the dependence of the GMR device resistance with the magnetic field, has been also developed and simulated. Its potential use as electric current sensors at the integrated circuit level has also been demonstrated

Correlated Timing and Spectral Variations of the Soft X-ray Transient Aquila X-1: Evidence for an Atoll classification

Based on Rossi X-ray Timing Explorer data, we discuss the classification of the soft X-ray transient Aquila X-1 in the Z/atoll scheme, and the relation of its kilohertz quasi-periodic oscillations (kHz QPO) properties to the X-ray colors. The color-color diagram shows one elongated ("banana") structure and several "islands" of data points. The power spectra of the island are best represented by a broken power-law, whereas those of the banana by a power-law below ~ 1 Hz plus an exponentially cut-off component at intermediate frequencies (30-60 Hz). The parameters of these two components change in correlation with the position of the source in the color-color diagram. Based on the pattern that the source shows in the color-color diagram and its aperiodic variability we conclude that Aquila X-1 is an atoll source. We have also investigated the possible correlation between the frequency of the kHz QPO and the position of the source in the color-color diagram. The complexity seen in the frequency versus count rate diagram is reduced to a single track when the frequency is plotted against hard or soft color.Comment: 9 pages, 5 figures. Accepted for publication in Ap

Optical and X-ray Outbursts of Be/X-ray binary system SAX J2103.5+4545

We present the relations between Halpha equivalent width, optical brightness and X-ray flux of Be/X-ray binary system SAX J2103.5+4545, by analyzing the optical photometric and spectroscopic observations together with the X-ray observations. In the photometric observations PSF photometry were applied using MIDAS and its DAOPHOT package. The reduction and analysis of spectra were done by using MIDAS and its suitable packages. The X-ray outburst of the system occurred just after the optical outburst. The nearly symmetric Halpha emission line profiles observed during the beginning of optical outburst turn into asymmetric profiles with increased EW values during the dissipation of Be disc. Halpha lines changed from emission to absorption during the observation period. The observed double peaked HeI emission lines might come from the accretion disc of neutron star which is temporarily formed at the time of X-ray outburst.Comment: to be pubished at Astronomy and Astrophysics on June 200

Optical variabilities in Be/X-ray binary system:GRO J2058+42

We present an analysis of long-term optical monitoring observations and optical spectroscopic observations of the counterpart to CXOU J205847.5+414637 (high mass X-ray binary system). We search for a variability in the light curve of Be star. We used differential magnitudes in the time series analysis. The variability search in the optical light curve was made by using different algorithms. The reduction and analysis of spectra were done by using MIDAS and its suitable packages. We have performed a frequency search which gave us the value 2.404 1/day. This value is attributed to the non-radial pulsation of Be star. H alpha emission line profiles always show double-peaked emissions with a mean equivalent width of 2.31 \pm 0.19 \AA ~and a peak separation of 516 \pm 45 km/s. This suggests that Be star disk is still present. CXOU J205847.5+414637 is in X-ray quiescent state.Comment: 8 pages, 9 figures. To appear at Astronomy and Astrophysic

Broadband Observations of the Be/X-ray Binary Pulsar RX J0440.9+4431: Discovery of a Cyclotron Absorption Line

We report the results of an analysis of data obtained with the INTEGRAL, Swift and RXTE observatories during the 2010 April and September outbursts of the X-ray pulsar RX J0440.9+4431. The temporal and spectral properties of the pulsar in a wide energy band (0.6-120 keV) were studied for the first time. We discovered a ~32 keV cyclotron resonant scattering feature in the source spectrum, that allowed us to estimate the magnetic field strength of the neutron star as B~3.2 x 10^12 G. The estimate of the magnetic field strength was confirmed by a comprehensive analysis of the noise power spectrum of the source. Based on the recurrence time between Type I outbursts the orbital period of the binary system can be estimated as ~155 days. We have shown that the pulse profile has a sinusoidal-like single-peaked shape and has practically no dependence on the source luminosity or energy band.Comment: 8 pages, 6 figures, accepted for publication in MNRA