Effects of continuous administration of 1,25-dihydroxyvitamin D3 on plasma minerals and unoccupied colon mucosal 1,25-dihydroxyvitamin D3 receptor concentrations

Six mature nonlactating, nonpregnant Jersey cows were implanted with Alzet mini-osmotic pumps, which delivered 50 micrograms of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] each day for 7 d in an effort to mimic plasma concentrations of 1,25-dihydroxyvitamin D [1,25-(OH)2D] observed in cows at parturition. Plasma samples were obtained daily beginning 6 d prior to implantation and ending 8 d after removal of the implants. Six biopsies of the descending colon mucosa were obtained per rectum before and after implantation and assayed for unoccupied 1,25-(OH)2D3 receptor concentration. Plasma concentration of 1,25-(OH)2D increased from 37 pg/ml pretreatment to 294 pg/ml with the pumps implanted. Plasma Ca concentration increased within 2 d after implantation and remained elevated for 7 d after the pumps were removed. Unoccupied colon mucosa 1,25-(OH)2D3 receptor mean concentration prior to treatment was 14.6 fmol/mg protein and increased within 2 d following implantation to 30.5 fmol/mg protein. These data suggest that 1,25-(OH)2D3 upregulates its own receptor in the intestine of the cow.     

Mumford-Shah model for one-to-one edge matching.

This paper presents a new algorithm based on the Mumford-Shah model for simultaneously detecting the edge features of two images and jointly estimating a consistent set of transformations to match them. Compared to the current asymmetric methods in the literature, this fully symmetric method allows one to determine one-to-one correspondences between the edge features of two images. The entire variational model is realized in a multiscale framework of the finite element approximation. The optimization process is guided by an estimation minimization-type algorithm and an adaptive generalized gradient flow to guarantee a fast and smooth relaxation. The algorithm is tested on T1 and T2 magnetic resonance image data to study the parameter setting. We also present promising results of four applications of the proposed algorithm: interobject monomodal registration, retinal image registration, matching digital photographs of neurosurgery with its volume data, and motion estimation for frame interpolation.     

A distributed delay-constrained dynamic multicast routing algorithm

Many new distributed multimedia applications involve dynamic multiple participants, have stringent end-to-end delay requirement and consume large amount of network resources. In this paper, we propose a distributed delay-constrained dynamic multicast routing algorithm (DCDMR) to support these applications. DCDMR scales well because the source of the multicast tree needs only limited computation or may even not be involved in the route computation. When group membership changes, the existing multicast tree is perturbed as little as possible and the resulting tree cost performance is very satisfactory.     

Modified Wilkinson Power Dividers for Millimeter-Wave Integrated Circuits

A modification of the Wilkinson power divider is presented that eases planar implementation while maintaining performance. By adding transmission lines between the resistor and the quarter-wave transformers of the traditional design, a range of valid solutions exists that meet the conditions of being reciprocal, isolated between the output ports, and matched at all ports. The proposed design is particularly useful at millimeter-wave frequencies where reduced physical dimensions make a circuit configuration suitable for low-cost package-level implementation difficult using traditional methods. Two frequency bands are demonstrated. At V-band, the circuit gives 0.3-dB excess insertion loss, 19-dB isolation, and 50% bandwidth. At the W-band, the circuit gives 0.75-dB excess insertion loss, 24-dB isolation, and 39% bandwidth.     

Evidence for Glass–glass Interfaces in a Columnar Cu–Zr Nanoglass

Comprehensive analyses of the atomic structure using advanced analytical transmission electron microscopy-based methods combined with atom probe tomography confirm the presence of distinct glass–glass interfaces in a columnar Cu-Zr nanoglass synthesized by magnetron sputtering. These analyses provide first-time in-depth characterization of sputtered film nanoglasses and indicate that glass–glass interfaces indeed present an amorphous phase with reduced mass density as compared to the neighboring amorphous regions. Moreover, dedicated analyses of the diffusion kinetics by time-of-flight secondary ion mass spectroscopy (ToF SIMS) prove significantly enhanced diffusivity, suggesting fast transport along the low density glass–glass interfaces. The present results further indicate that sputter deposition is a feasible technique for reliable production of nanoglasses and that some of the concepts proposed for this new class of glassy materials are applicable.     

Amplitude-modulation detection in single-stage negative-feedback amplifiers due to interfering out-of-band signals

The electromagnetic-interference effects of out-of-band signals on negative-feedback amplifiers are investigated. It is assumed that the interfering signals picked up at the input of the amplifier are dominant. Due to the nonlinear behavior of the active devices in the amplifier, unwanted dc shifts and amplitude-modulation (AM) detection may occur. Describing these effects is usually done by using the Volterra series. Although providing good results when used for analysis, methods to use the Volterra series for the design process are not yet mature enough. A simple procedure for calculating AM detection is presented. An equivalent source at the input of the amplifier is introduced that accounts for the nonlinear effects. Because the characteristics of this source are computed as a function of design parameters, this procedure facilitates a synthesis approach for designing amplifiers with a lower susceptibility to AM detection. It is shown that the root locus of the amplifier transfer function has a large influence on the amount of AM detection and, therefore, on the electromagnetic compatibility. Measurements made on a single-stage negative-feedback amplifier support the presented procedure.     

Dynamic Control Over Electronic Transport in 3D Bulk Nanographene via Interfacial Charging

Electrochemical surface charge‐induced variation of physical properties in interface‐dominated bulk materials is a rapidly emerging field in material science. The recently developed three‐dimensional bulk nanographene (3D‐BNG) macro‐assemblies with ultra‐high surface area and chemical inertness offer new opportunities in this area. Here, the electronic transport in centimeter‐sized 3D‐BNG monoliths can be dynamically controlled via electrochemically induced surface charge density. Specifically, a fully reversible variation in macroscopic conductance up to several hundred percent is observed with ≤1 V applied gate potential. The observed conductivity change can be explained in the light of the electrochemically‐induced accumulation or depletion of charge carriers in combination with a large variation in the carrier mobility; the latter, being highly affected by the defect density modulations resulting from the interfacial charge injection, sharply decreases with an increase in defect concentrations. The phenomenon presented in this study is believed to open the door to novel applications of bulk graphene materials such as, for example, low voltage and high power tunable resistors.     

Capacitively coupled transmission line pulsing cc-TLP––a traceable and reproducible stress method in the CDM-domain

This paper describes a new test method called capacitively coupled transmission line pulsing cc-TLP. It is applied to different test circuits which were mounted on specially designed package emulators with a defined background capacitance. The test results are compared with the ESD thresholds obtained by CDM tests. The cc-TLP results correlate well with the CDM data.     

High-yield flip-chip bonding and packaging of low-threshold VCSEL arrays on sapphire substrates

Oxide-confined top-emitting 850 nm and bottom-emitting 980 nm vertical-cavity surface-emitting laser (VCSEL) 8/spl times/8 arrays were designed and fabricated for applications of optical interconnects. The arrays were flip-chip bonded onto sapphire substrates that contain complimentary metal-oxide-semiconductor (CMOS) driver and fan-out circuitries. The off-sited bonding contacts and minimized bonding force produced very high yield of the hybridization process without causing damage to the VCSEL mesas. The hybridized devices were further mounted either on printed circuit board (PCB) or in 68-pin pin-grid-array (PGA) packages. The transparent sapphire substrate allowed optical outputs from the top-emitting VCSEL arrays to transmit directly through without additional substrate removal procedure. Lasing thresholds below 250 /spl mu/A for 850 nm VCSELs and 800 /spl mu/A for 980 nm VCSEL were found at room temperature. The oxide confinement apertures of VCSELs were measured to be around 6 /spl mu/m in diameter. High-speed data transmission demonstrated a bandwidth of up to 1 Gbits/s per channel for these hybridized VCSEL transmitters.     

Measurement and Calculation of the Absolute Thermoelectric Power of Rhodium and Iridium

The thermoelectric power of Rh and Ir was redetermined between 100 K and 1400 K. It varies almost linearly from +1.7 μV K⁻¹ to −3.8 μV K⁻¹ for Rh and from +1.5 μV K⁻¹ to −2.2 μV K⁻¹ for Ir. The diffusive part of the thermopower could be calculated from the density of states. It is approximately equal to the temperature dependence of the electrochemical potential of the electrons divided by the electronic charge. This is attributed to the approximate establishment of local equilibrium between electrons and lattice atoms above 400 K—a condition not fulfilled in the phonon-drag regime below 300 K.