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We investigate the insulating phase that forms in a titanium nitride film in a close vicinity of the disorder-driven superconductor-insulator transition. In zero magnetic field the temperature dependence of the resistance reveals a sequence of distinct regimes upon decreasing temperature crossing over from logarithmic to activated behavior with the variable-range hopping squeezing in between. In perpendicular magnetic fields below 2 T, the thermally activated regime retains at intermediate temperatures, whereas at ultralow temperatures, the resistance increases faster than that of the thermally activated type. This indicates a change of the mechanism of the conductivity. We find that at higher magnetic fields the thermally activated behavior disappears and the magnetoresistive isotherms saturate towards the value close to quantum resistance h/ e2. [ABSTRACT FROM AUTHOR]

Planning and implementing a successful immunization program at the worksite requires a committed, interdepartmental effort and a dedicated occupational health staff. Planning should start well in advance of influenza season with adherence to strict timelines.Key strategies for campaign success include generating a sense of enthusiasm about the campaign; creating an employee- and family-friendly atmosphere to diffuse possible uneasiness about receiving vaccinations; assuring easy access to vaccines; and providing employees with evidence-based information related to influenza and immunization using a variety of media.Using the proven best practices of its on-site employee health vendor and adapting other strategies, the vaccine manufacturer succeeded in raising employee influenza immunization rates from 34% in 2002 to 66% by the end of November 2003, well beyond the program's goal of 50%. By the end of December, after extra clinics were added in response to intense media coverage, the employee immunization rate increased to 76%. [ABSTRACT FROM AUTHOR]

A soy-protein isolate diet that was deficient in methionine (Met), zinc (Zn), riboflavin, vitamin B-6 and choline for chick growth (Assay 1) was used to study individual or multiple deficiencies of several of these nutrients. In all cases, adding all three deficient nutrients together resulted in growth responses that were superior to those resulting from supplementation with any pairs of deficient nutrients. In Assay 2, single addition of Zn but not of methionine or riboflavin produced a growth response, but the combination of either Zn and Met or Zn and riboflavin resulted in growth responses that were greater than the response elicited by Zn alone. Assay 3 involved individual or multiple deficiencies of choline, riboflavin and vitamin B-6, and individual additions suggested that choline was first limiting. Choline + riboflavin supplementation, however, produced marked growth and gain:food responses that were far greater than those resulting from supplemental choline or riboflavin alone. Moreover, the growth response to a combination of choline + pyridoxine (PN) was also greater than that obtained from any of the three nutrients fed alone; even PN + riboflavin (in the absence of choline) produced responses greater than those observed with the unsupplemented negative-control diet. In Assay 4, chicks responded to individual additions of riboflavin, PN or Met, and in Assay 5, to either riboflavin or PN; all two-way combinations resulted in growth rates that were far greater than those occurring with any single addition. The data from these experiments show that unlike the situation with three deficient amino acids, the expected responses to first-, second- and third-limiting B-vitamins or deficient vitamins combined with deficient levels of Zn or Met do not follow the expected pattern of response to first-, further response to first- and second- and an even further response to first-, second- and third-limiting nutrients. [ABSTRACT FROM AUTHOR]

On the back cover, a single wall carbon nanotube is displayed (thin black line in the sketch) that is grown across a trench and contact electrodes (green), cooled to milli‐Kelvin temperatures, and then characterized in electronic transport measurements. A quantum dot forms within the suspended segment at these temperatures. The typical Coulomb “diamond” pattern of differential conductance displays distinct signatures of electromechanical feedback and self‐excitation (background measurement, yellow arrows). Using a radio‐frequency cw source, driven mechanical resonances of the nanotube can be detected in dc transport ‐ as exemplified by the red line, a measurement of time‐averaged dc current as a function of the driving frequency. Stiller et al. (pp. 2518–2522) find higher harmonic resonances at integer multiples of the fundamental frequency, indicating that the nanotube is a string under tension. Applying a finite gate voltage to the highly doped chip substrate (light blue), the mechanical resonance strongly shifts to lower frequencies. This can be explained by electrostatic softening of the vibration mode. [ABSTRACT FROM AUTHOR]

Low-temperature electronic transport measurements with high energy resolution require both effective low-pass filtering of high-frequency input noise and an optimized thermalization of the electronic system of the experiment. In recent years, elaborate filter designs have been developed for cryogenic low-level measurements, driven by the growing interest in fundamental quantum-physical phenomena at energy scales corresponding to temperatures in the few millikelvin regime. However, a single filter concept is often insufficient to thermalize the electronic system to the cryogenic bath and eliminate spurious high frequency noise. Moreover, the available concepts often provide inadequate filtering to operate at temperatures below 10 mK, which are routinely available now in dilution cryogenic systems. Herein we provide a comprehensive analysis of commonly used filter types, introduce a novel compact filter type based on ferrite compounds optimized for the frequency range above 20 GHz, and develop an improved filtering scheme providing adaptable broad-band low-pass characteristic for cryogenic low-level and quantum measurement applications at temperatures down to few millikelvin. [ABSTRACT FROM AUTHOR]