3,181 research outputs found
Revealing charge-tunneling processes between a quantum dot and a superconducting island through gate sensing
We report direct detection of charge-tunneling between a quantum dot and a
superconducting island through radio-frequency gate sensing. We are able to
resolve spin-dependent quasiparticle tunneling as well as two-particle
tunneling involving Cooper pairs. The quantum dot can act as an RF-only sensor
to characterize the superconductor addition spectrum, enabling us to access
subgap states without transport. Our results provide guidance for future
dispersive parity measurements of Majorana modes, which can be realized by
detecting the parity-dependent tunneling between dots and islands.Comment: 6 pages, 4 figures, supplemental material included as ancillary fil
Visceral Leishmaniasis in Traveler to Guyana Caused by Leishmania siamensis, London, UK.
The parasite Leishmania siamensis is a zoonotic agent of leishmaniasis; infection in animals has been documented in Europe and the United States. Reported authochthonous human infections have been limited to Thailand. We report a case of human visceral Leishmania siamensis infection acquired in Guyana, suggesting colonization in South America
Neutrino oscillations in matter of varying density
We consider two-family neutrino oscillations in a medium of
continuously-varying density as a limit of the process in a series of
constant-density layers. We construct analytic expressions for the conversion
amplitude at high energies within a medium with a density profile that is
piecewise linear. We compare some cases to understand the type of effects that
depend on the order of the material traversed by a neutrino beam.Comment: 10 page
Verifying the Kugo-Ojima Confinement Criterion in Landau Gauge Yang-Mills Theory
Expanding the Landau gauge gluon and ghost two-point functions in a power
series we investigate their infrared behavior. The corresponding powers are
constrained through the ghost Dyson-Schwinger equation by exploiting
multiplicative renormalizability. Without recourse to any specific truncation
we demonstrate that the infrared powers of the gluon and ghost propagators are
uniquely related to each other. Constraints for these powers are derived, and
the resulting infrared enhancement of the ghost propagator signals that the
Kugo-Ojima confinement criterion is fulfilled in Landau gauge Yang-Mills
theory.Comment: 4 pages, no figures; version to be published in Physical Review
Letter
Experimental Investigation of Solder Joint Defect Formation and Mitigation in Reduced-Gravity Environments
This paper documents a research effort on reduced gravity soldering of plated through hole joints which was conducted jointly by the National Center for Space Exploration Research, NASA Glenn Research Center, and NASA Johnson Space Center. Significant increases in joint porosity and changes in external geometry were observed in joints produced in reduced gravity as compared to normal gravity. Multiple techniques for mitigating the observed increase in porosity were tried, including several combinations of flux and solder application techniques, and demoisturizing the circuit board prior to soldering. Results were consistent with the hypothesis that the source of the porosity is a combination of both trapped moisture in the circuit board itself, as well as vaporized flux that is trapped in the molten solder. Other topics investigated include correlation of visual inspection results with joint porosity, pore size measurements, limited pressure effects (0.08 MPa - 0.1 MPa) on the size and number of pores, and joint cooling rate
Brief report: how adolescents with ASD process social information in complex scenes. Combining evidence from eye movements and verbal descriptions
We investigated attention, encoding and processing of social aspects of complex photographic scenes. Twenty-four high-functioning adolescents (aged 11–16) with ASD and 24 typically developing matched control participants viewed and then described a series of scenes, each containing a person. Analyses of eye movements and verbal descriptions provided converging evidence that both groups displayed general interest in the person in each scene but the salience of the person was reduced for the ASD participants. Nevertheless, the verbal descriptions revealed that participants with ASD frequently processed the observed person’s emotion or mental state without prompting. They also often mentioned eye-gaze direction, and there was evidence from eye movements and verbal descriptions that gaze was followed accurately. The combination of evidence from eye movements and verbal descriptions provides a rich insight into the way stimuli are processed overall. The merits of using these methods within the same paradigm are discussed
Incomplete renal tubular acidosis as a predisposing factor for calcium phosphate stones in neuropathic bladder: a case report
We present a male tetraplegic patient, who developed stones in neuropathic bladder six times within a span of three years. Unusual features of this case are: (1) This patient started developing stones in urinary bladder thirteen years after sustaining spinal cord injury. (2) He was performing intermittent catheterisation and did not have an indwelling catheter. (3) The presenting symptom of vesical lithiasis was abdominal spasms and not urine infection. (4) The major component of the stones was calcium phosphate; magnesium ammonium phosphate was completely absent in the calculus on four occasions. (5) Proteus species were not grown from urine at any time. (6) This patient failed to acidify urine below a pH of 5.3 after taking simultaneously furosemide (40 mg) and fludrocortrisone (1 mg), which suggested incomplete renal tubular acidosis type 1
Horizontal And Vertical Movements Of Juvenile Bluefin Tuna (Thunnus Thynnus), In Relation To Oceanographic Conditions Of The Western North Atlantic, Determined With Ultrasonic Telemetry
We employed ultrasonic transmitters to follow (for up to 48 h) the horizontal and vertical movements of five juvenile (6.8-18.7 kg estimated body mass) bluefin tuna (Thunnus thynnus) in the western North Atlantic (off the eastern shore of Virginia). Our objective was to document the fishes\u27 behavior and distribution in relation to oceanographic conditions and thus begin to address issues that currently limit population assessments based on aerial surveys. Estimation of the trends in adult and juvenile Atlantic bluefin tuna abundance by aerial surveys, and other fishery-independent measures, is considered a priority. Juvenile bluefin tuna spent the majority of their time over the continental shelf in relatively shallow water (generally less then 40 m deep). Fish used the entire water column in spite of relatively steep vertical thermal gradients (approximate to24degreesC at the surface and approximate to12degreesC at 40 m depth), but spent the majority of their time (approximate to90%) above 15 m and in water warmer then 20degreesC, Mean swimming speeds ranged from 2.8 to 3.3 knots, and total distance covered from 152 to 289 km (82-156 nmi). Because fish generally remained within relatively confined areas, net displacement was only 7.7-52.7 km (4.1-28.4 nmi). Horizontal movements were not correlated with sea surface temperature. We propose that it is unlikely that juvenile bluefin tuna in this area can detect minor horizontal temperature gradients (generally less then 0.5degreesC/km) because of the steep vertical temperature gradients (up to approximate to0.6degreesC/m) they experience during their regular vertical movements. In contrast, water clarity did appear to influence behavior because the fish remained in the intermediate water mass between the turbid and phytoplankton-rich plume exiting Chesapeake Bay (and similar coastal waters) and the clear oligotrophic water east of the continental shelf
Uniform shrinking and expansion under isotropic Brownian flows
We study some finite time transport properties of isotropic Brownian flows.
Under a certain nondegeneracy condition on the potential spectral measure, we
prove that uniform shrinking or expansion of balls under the flow over some
bounded time interval can happen with positive probability. We also provide a
control theorem for isotropic Brownian flows with drift. Finally, we apply the
above results to show that under the nondegeneracy condition the length of a
rectifiable curve evolving in an isotropic Brownian flow with strictly negative
top Lyapunov exponent converges to zero as with positive
probability
Transition from pediatric to adult renal services: a consensus statement by the International Society of Nephrology (ISN) and the International Pediatric Nephrology Association (IPNA)
The transfer of young patients from pediatric to adult renal care takes place after a transition process which involves both sides. It is important that it is individualized for each young person, focusing on self-management skills as well as assessing support structures. The consensus statement has been developed by the panel of adult and pediatric nephrologists and endorsed by the councils of both ISN and IPNA. It is hoped that the statement will provide a basis for the development of locally appropriate recommendations for clinical practice
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