46 research outputs found
Anisotropic magnetoresistance in single electron transport
We study the effect of magnetic anisotropy in a single electron transistor
with ferromagnetic electrodes and a non-magnetic island. We identify the
variation of the chemical potential of the electrodes as a
function of the magnetization orientation as a key quantity that permits to
tune the electrical properties of the device. Different effects occur depending
on the relative size of and the charging energy. We provide
preliminary quantitative estimates of using a very simple toy
model for the electrodes.Comment: Conference article presented at PASPS IV, Sendai, August 200
Thermo-Electric Properties of Quantum Point Contacts
I. Introduction
II. Theoretical background (Landauer-Buttiker formalism of
thermo-electricity, Quantum point contacts as ideal electron waveguides,
Saddle-shaped potential)
III. Experiments (Thermopower, Thermal conductance, Peltier effect)
IV. ConclusionsComment: #4 of a series of 4 legacy reviews on QPC'
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WeaselBoard : zero-day exploit detection for programmable logic controllers.
Critical infrastructures, such as electrical power plants and oil refineries, rely on programmable logic controllers (PLCs) to control essential processes. State of the art security cannot detect attacks on PLCs at the hardware or firmware level. This renders critical infrastructure control systems vulnerable to costly and dangerous attacks. WeaselBoard is a PLC backplane analysis system that connects directly to the PLC backplane to capture backplane communications between modules. WeaselBoard forwards inter-module traffic to an external analysis system that detects changes to process control settings, sensor values, module configuration information, firmware updates, and process control program (logic) updates. WeaselBoard provides zero-day exploit detection for PLCs by detecting changes in the PLC and the process. This approach to PLC monitoring is protected under U.S. Patent Application 13/947,887
Concept and design of a genome-wide association genotyping array tailored for transplantation-specific studies
Background: In addition to HLA genetic incompatibility, non-HLA difference between donor and recipients of transplantation leading to allograft rejection are now becoming evident. We aimed to create a unique genome-wide platform to facilitate genomic research studies in transplant-related studies. We designed a genome-wide genotyping tool based on the most recent human genomic reference datasets, and included customization for known and potentially relevant metabolic and pharmacological loci relevant to transplantation. Methods: We describe here the design and implementation of a customized genome-wide genotyping array, the âTxArrayâ, comprising approximately 782,000 markers with tailored content for deeper capture of variants across HLA, KIR, pharmacogenomic, and metabolic loci important in transplantation. To test concordance and genotyping quality, we genotyped 85 HapMap samples on the array, including eight trios. Results: We show low Mendelian error rates and high concordance rates for HapMap samples (average parent-parent-child heritability of 0.997, and concordance of 0.996). We performed genotype imputation across autosomal regions, masking directly genotyped SNPs to assess imputation accuracy and report an accuracy of >0.962 for directly genotyped SNPs. We demonstrate much higher capture of the natural killer cell immunoglobulin-like receptor (KIR) region versus comparable platforms. Overall, we show that the genotyping quality and coverage of the TxArray is very high when compared to reference samples and to other genome-wide genotyping platforms. Conclusions: We have designed a comprehensive genome-wide genotyping tool which enables accurate association testing and imputation of ungenotyped SNPs, facilitating powerful and cost-effective large-scale genotyping of transplant-related studies. Electronic supplementary material The online version of this article (doi:10.1186/s13073-015-0211-x) contains supplementary material, which is available to authorized users
Concept and design of a genome-wide association genotyping array tailored for transplantation-specific studies
Hematemesis in an eight-year-old female as a presenting symptom of portal vein thrombosis following neonatal umbilical vein catheterization
Cardiovascular Events Among Survivors of Sepsis Hospitalization: A Retrospective Cohort Analysis
Background Sepsis is associated with an elevated risk of late cardiovascular events among hospital survivors. Methods and Results We included OptumLabs Data Warehouse patients from 2009 to 2019 who survived a medical/nonsurgical hospitalization lasting at least 2 nights. The association between sepsis during hospitalization, based on explicit and implicit discharge International Classification of Diseases, Ninth Revision (ICDâ9)/Tenth Revision (ICDâ10) diagnosis codes, with subsequent death and rehospitalization was analyzed using KaplanâMeier survival analysis and multivariable Cox proportionalâhazards models. The study population included 2â258â464 survivors of nonsurgical hospitalization (5â396â051 total patientâyears of followâup). A total of 808â673 (35.8%) patients had a sepsis hospitalization, including implicit sepsis only in 448â644, explicit sepsis only in 124â841, and both in 235â188. Patients with sepsis during hospitalization had an elevated risk of allâcause mortality (adjusted hazard ratio [HR], 1.27 [95% CI, 1.25â1.28]; P<0.001), allâcause rehospitalization (adjusted HR, 1.38 [95% CI, 1.37â1.39]; P<0.001), and cardiovascular hospitalization (adjusted HR, 1.43 [95% CI, 1.41â1.44]; P<0.001), especially heart failure hospitalization (adjusted HR, 1.51 [95% CI, 1.49â1.53]). Patients with implicit sepsis had higher risk than those with explicit sepsis. A sensitivity analysis using the first hospitalization yielded concordant results for cardiovascular hospitalization (adjusted HR, 1.78 [95% CI, 1.76â1.78]; P<0.001), as did a propensityâweighted analysis (adjusted HR, 1.52 [95% CI, 1.50â1.54]; P<0.001). Conclusions Survivors of sepsis hospitalization are at elevated risk of early and late postâdischarge death as well as cardiovascular and nonâcardiovascular rehospitalization. This hazard spans the spectrum of cardiovascular events and may suggest that sepsis is an important cardiovascular risk factor