Electron spin manipulation and resonator readout in a double quantum dot nano-electromechanical system

Magnetically coupling a nano-mechanical resonator to a double quantum dot confining two electrons can enable the manipulation of a single electron spin and the readout of the resonator's natural frequency. When the Larmor frequency matches the resonator frequency, the electron spin in one of the dots can be selectively flipped by the magnetised resonator. By simultaneously measuring the charge state of the two-electron double quantum dots, this transition can be detected thus enabling the natural frequency of the mechanical resonator to be determined.Comment: 7 pages, fixed typos, updated figures 4 and

Probing a spin transfer controlled magnetic nanowire with a single nitrogen-vacancy spin in bulk diamond

The point-like nature and exquisite magnetic field sensitivity of the nitrogen vacancy (NV) center in diamond can provide information about the inner workings of magnetic nanocircuits in complement with traditional transport techniques. Here we use a single NV in bulk diamond to probe the stray field of a ferromagnetic nanowire controlled by spin transfer (ST) torques. We first report an unambiguous measurement of ST tuned, parametrically driven, large-amplitude magnetic oscillations. At the same time, we demonstrate that such magnetic oscillations alone can directly drive NV spin transitions, providing a potential new means of control. Finally, we use the NV as a local noise thermometer, observing strong ST damping of the stray field noise, consistent with magnetic cooling from room temperature to $\sim$150 K.Comment: 6 pages, 5 figures, plus supplementary informatio

Spin filling of a quantum dot derived from excited-state spectroscopy

We study the spin filling of a semiconductor quantum dot using excited-state spectroscopy in a strong magnetic field. The field is oriented in the plane of the two-dimensional electron gas in which the dot is electrostatically defined. By combining the observation of Zeeman splitting with our knowledge of the absolute number of electrons, we are able to determine the ground state spin configuration for one to five electrons occupying the dot. For four electrons, we find a ground state spin configuration with total spin S=1, in agreement with Hund's first rule. The electron g-factor is observed to be independent of magnetic field and electron number.Comment: 11 pages, 7 figures, submitted to New Journal of Physics, focus issue on Solid State Quantum Informatio

Nonphysician providers in hospital medicine: Not so fast

No abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/64916/1/584_ftp.pd

Main conceptual provisions of the creation of an electronic state register of immovable cultural heritage of Ukraine. Part 1

Annotation. To organize the creation of a new modern electronic State Register of Immovable Cultural Heritage (CH) of Ukraine, it is proposed to use a methodology based on the so-called Solutions Frameworks (SoFr) "something" = X, where X denotes both the specified system (subsystem) and class of such systems (subsystems). The application of SoFr to X entirely is called the main conceptual position 0 in the article, but despite its obviousness, the epigraph is applicable to the construction of X SoFr: “The hardest thing is to see what is right in front of you. - Goethe» [1; Preface]. X in the X SoFr record takes the meaning of a hierarchically structured Atlas Geoinformation System (AGIS), consisting of four strata (bottom-up ­): Operational (w), Application (a), Conceptual (b) and General (g). X SoFr in the article takes three meanings: SoFr AGIS1 (defines the activity of creating the first stage of AGIS - AGIS1 = X), aSoFr AGIS1 (defines the activity "between" subsystems AGIS1 Application and Operational strata top-down ¯), bSoFr AGIS1 determines the activity "between" the subsystems of AGIS1 Conceptual and Application strata from top to bottom ¯).  X SoFr is determined by the packages and the relation between them, the so-called "petrad" of Publication-Products-Processes-Basics-Services. Packages Products-Processes-Basics and the relation between them are called the main triad of SoFr. This triad is the basis of the main conceptual provisions 1-3. They are formulated as follows: SoFr.Products - provision 1, SoFr.Processes - provision 2, SoFr.Basics - provision 3. Part 1 describes the introduction to the problem and provisions 0 and 1. Provisions 2, 3 are described in Part 2. The methodology, based on the Solutions Frameworks, implements a specific systematic approach to creating a new modern electronic State Register of Immovable Cultural Heritage of Ukraine

Supercritical water-cooled nuclear reactors: thermodynamic-cycles options

Paper presented at the 6th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 30 June - 2 July, 2008.Currently there are a number of Generation IV SuperCritical Water-cooled nuclear Reactor (SCWR) concepts under development worldwide. The main objectives for developing and utilizing SCWRs are: 1) Increase gross thermal efficiency of current Nuclear Power Plants (NPPs) from 33 – 35% to approximately 45 – 50%, and 2) Decrease the capital and operational costs and, in doing so, decrease electrical-energy costs (~$1000 US/kW or even less). SCW NPPs will have much higher operating parameters compared to current NPPs (i.e., pressures of about 25 MPa and outlet temperatures up to 625°C). Additionally, SCWRs will have a simplified flow circuit in which steam generators, steam dryers, steam separators, etc. will be eliminated. Furthermore, SCWRs operating at higher temperatures can facilitate an economical co-generation of hydrogen through thermo-chemical cycles (particularly, the copper-chlorine cycle) or direct high-temperature electrolysis. To decrease significantly the development costs of a SCW NPP, to increase its reliability, and to achieve similar high thermal efficiencies as the advanced fossil steam cycles it should be determined whether SCW NPPs can be designed with a steam-cycle arrangement that closely matches that of mature SuperCritical (SC) fossil power plants (including their SC turbine technology). The state-of-the-art SC steam cycles in fossil power plants are designed with a single-steam reheat and regenerative feedwater heating and reach thermal steamcycle efficiencies up to 54% (i.e., net plant efficiencies of up to 43% on a Higher Heating Value (HHV) Basis). Therefore, simplified no-reheat, single-reheat, and double-reheat cycles without heat regeneration and a singlereheat cycle with heat regeneration based on the expected steam parameters of future SCW NPPs were analyzed in terms of their thermal efficiencies. On this basis, several conceptual steam-cycle arrangements of pressure-tube SCWRs, their corresponding T–s diagrams and steam-cycle thermal efficiencies (based on constant isentropic turbine and polytropic pump efficiencies) are presented in this paper.vk201

A two-stage genome-wide association study of sporadic amyotrophic lateral sclerosis

The cause of sporadic amyotrophic lateral sclerosis (ALS) is largely unknown, but genetic factors are thought to play a significant role in determining susceptibility to motor neuron degeneration. To identify genetic variants altering risk of ALS, we undertook a two-stage genome-wide association study (GWAS): we followed our initial GWAS of 545 066 SNPs in 553 individuals with ALS and 2338 controls by testing the 7600 most associated SNPs from the first stage in three independent cohorts consisting of 2160 cases and 3008 controls. None of the SNPs selected for replication exceeded the Bonferroni threshold for significance. The two most significantly associated SNPs, rs2708909 and rs2708851 [odds ratio (OR) = 1.17 and 1.18, and P-values = 6.98 x 10–7 and 1.16 x 10–6], were located on chromosome 7p13.3 within a 175 kb linkage disequilibrium block containing the SUNC1, HUS1 and C7orf57 genes. These associations did not achieve genome-wide significance in the original cohort and failed to replicate in an additional independent cohort of 989 US cases and 327 controls (OR = 1.18 and 1.19, P-values = 0.08 and 0.06, respectively). Thus, we chose to cautiously interpret our data as hypothesis-generating requiring additional confirmation, especially as all previously reported loci for ALS have failed to replicate successfully. Indeed, the three loci (FGGY, ITPR2 and DPP6) identified in previous GWAS of sporadic ALS were not significantly associated with disease in our study. Our findings suggest that ALS is more genetically and clinically heterogeneous than previously recognized. Genotype data from our study have been made available online to facilitate such future endeavors

Motor neuronopathy with dropped hands and downbeat nystagmus: A distinctive disorder? A case report

BACKGROUND: Eye movements are clinically normal in most patients with motor neuron disorders until late in the disease course. Rare patients are reported to show slow vertical saccades, impaired smooth pursuit, and gaze-evoked nystagmus. We report clinical and oculomotor findings in three patients with motor neuronopathy and downbeat nystagmus, a classic sign of vestibulocerebellar disease. CASE PRESENTATION: All patients had clinical and electrodiagnostic features of anterior horn cell disease. Involvement of finger and wrist extensors predominated, causing finger and wrist drop. Bulbar or respiratory dysfunction did not occur. All three had clinically evident downbeat nystagmus worse on lateral and downgaze, confirmed on eye movement recordings using the magnetic search coil technique in two patients. Additional oculomotor findings included alternating skew deviation and intermittent horizontal saccadic oscillations, in one patient each. One patient had mild cerebellar atrophy, while the other two had no cerebellar or brainstem abnormality on neuroimaging. The disorder is slowly progressive, with survival up to 30 years from the time of onset. CONCLUSION: The combination of motor neuronopathy, characterized by early and prominent wrist and finger extensor weakness, and downbeat nystagmus with or without other cerebellar eye movement abnormalities may represent a novel motor neuron syndrome

Performance issues in optical burst/packet switching

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-01524-3_8This chapter summarises the activities on optical packet switching (OPS) and optical burst switching (OBS) carried out by the COST 291 partners in the last 4 years. It consists of an introduction, five sections with contributions on five different specific topics, and a final section dedicated to the conclusions. Each section contains an introductive state-of-the-art description of the specific topic and at least one contribution on that topic. The conclusions give some points on the current situation of the OPS/OBS paradigms