1,035 research outputs found
Detection of qubit-oscillator entanglement in nanoelectromechanical systems
Experiments over the past years have demonstrated that it is possible to
bring nanomechanical resonators and superconducting qubits close to the quantum
regime and to measure their properties with an accuracy close to the Heisenberg
uncertainty limit. Therefore, it is just a question of time before we will
routinely see true quantum effects in nanomechanical systems. One of the
hallmarks of quantum mechanics is the existence of entangled states. We propose
a realistic scenario making it possible to detect entanglement of a mechanical
resonator and a qubit in a nanoelectromechanical setup. The detection scheme
involves only standard current and noise measurements of an atomic point
contact coupled to an oscillator and a qubit. This setup could allow for the
first observation of entanglement between a continuous and a discrete quantum
system in the solid state.Comment: 9 pages, 3 figure
DEFINING, MEASURING, AND ANALYZING DEFENSIBILITY IN THE DEFENSIVE CYBER OPERATIONS CONTEXT
When talking about cyber systems, both researchers and decision makers have used the term "defensibility" widely, but there is no universal definition for it and no method to observe and measure it. This study examines how defensibility can be defined in a defensive cyber operations context, what critical factors constitute it, and how those factors could be measured. This is done by first examining doctrine and research to create a framework of meaning for defensibility. Second, the study proposes seven fundamental capabilities that a defender needs to be able to perform in defensive cyber operations and a set of system attributes that affect those capabilities. Finally, a set of measures for those attributes is proposed to allow defensibility to be observed and measured. The results of this study are a definition of defensibility for the defensive cyber operations context, a list of system attributes that constitute its defensibility, and a set of associated measurements for these attributes. Using these, it is possible to analyze the defensibility of a system to indicate what restrictions a defender might have when conducting operations in the system and the areas where the system needs to improve. This work is the first step in building defensibility into a useful tool that highlights the needs of a defensive actor who conducts dynamic defensive operations in a system, versus the needs of an actor who implements static measures to increase cyber security.Löjtnant, Swedish NavyApproved for public release. Distribution is unlimited
An advanced microcomputer design for processing of semiconductor materials
In the Get Away Special 330 payload two germanium samples doped with gallium will be processed. The aim of the experiments is to create a planar solid/liquid interface, and to study the breakdown of this interface as the crystal growth rate increases. For the experiments a gradient furnace was designed which is heated by resistive heaters. Cooling is provided by circulating gas from the atmosphere in the cannister through cooling channels in the furnace. The temperature along the sample are measured by platinum/rhodium thermocouples. The furnace is controlled by a microcomputer system, based upon the processor 80C88. A data acquisition system is integrated into the system. In order to synchronize the different actions in time, a multitask manager is used
Self-Renormalization of the Classical Quasilocal Energy
Pointlike objects cause many of the divergences that afflict physical
theories. For instance, the gravitational binding energy of a point particle in
Newtonian mechanics is infinite. In general relativity, the analog of a point
particle is a black hole and the notion of binding energy must be replaced by
quasilocal energy. The quasilocal energy (QLE) derived by York, and elaborated
by Brown and York, is finite outside the horizon but it was not considered how
to evaluate it inside the horizon. We present a prescription for finding the
QLE inside a horizon, and show that it is finite at the singularity for a
variety of types of black hole. The energy is typically concentrated just
inside the horizon, not at the central singularity.Comment: 7 pages, 4 figure
Strigolactone biosynthesis is evolutionarily conserved, regulated by phosphate starvation and contributes to resistance against phytopathogenic fungi in a moss, Physcomitrella patens
In seed plants, strigolactones (SLs) regulate architecture and induce mycorrhizal symbiosis in response to environmental cues. SLs are formed by combined activity of the carotenoid cleavage dioxygenases (CCDs) 7 and 8 from 9-cis-β-carotene, leading to carlactone that is converted by cytochromes P450 (clade 711; MAX1 in Arabidopsis) into various SLs. As Physcomitrella patens possesses CCD7 and CCD8 homologs but lacks MAX1, we investigated if PpCCD7 together with PpCCD8 form carlactone and how deletion of these enzymes influences growth and interactions with the environment. We investigated the enzymatic activity of PpCCD7 and PpCCD8 in vitro, identified the formed products by high performance liquid chromatography (HPLC) and LC-MS, and generated and analysed ΔCCD7 and ΔCCD8 mutants. We defined enzymatic activity of PpCCD7 as a stereospecific 9-cis-CCD and PpCCD8 as a carlactone synthase. ΔCCD7 and ΔCCD8 lines showed enhanced caulonema growth, which was revertible by adding the SL analogue GR24 or carlactone. Wild-type (WT) exudates induced seed germination in Orobanche ramosa. This activity was increased upon phosphate starvation and abolished in exudates of both mutants. Furthermore, both mutants showed increased susceptibility to phytopathogenic fungi. Our study reveals the deep evolutionary conservation of SL biosynthesis, SL function, and its regulation by biotic and abiotic cues.Deutsche Forschungsgemeinschaft AL892/1-4Academy of Finland 125312
Scintigraphic features of Morquio's syndrome: a case report
<p>Abstract</p> <p>Introduction</p> <p>To the best of our knowledge, we present for the first time the bone scintigraphy findings of a patient with Morquio's syndrome.</p> <p>Case presentation</p> <p>A 46-year-old Caucasian man with Morquio's syndrome presented with lower back pain six weeks after a left total hip replacement. A whole body bone scan demonstrated an anthropomorphic skeletal pattern consistent with a mucopolysaccharide storage disease, thereby showing the cause of the patient's pain.</p> <p>Conclusions</p> <p>To the best of our knowledge, the bone scintigraphy findings of a case of Morquio's syndrome have never before been published. We present our case report to add to the knowledge we have of this rare disease.</p
IMMUNOCAT—A Data Management System for Epitope Mapping Studies
To enable rationale vaccine design, studies of molecular and cellular mechanisms of immune recognition need to be linked with clinical studies in humans. A major challenge in conducting such translational research studies lies in the management and integration of large amounts and various types of data collected from multiple sources. For this purpose, we have established “IMMUNOCAT”, an interactive data management system for the epitope discovery research projects conducted by our group. The system provides functions to store, query, and analyze clinical and experimental data, enabling efficient, systematic, and integrative data management. We demonstrate how IMMUNOCAT is utilized in a large-scale research contract that aims to identify epitopes in common allergens recognized by T cells from human donors, in order to facilitate the rational design of allergy vaccines. At clinical sites, demographic information and disease history of each enrolled donor are captured, followed by results of an allergen skin test and blood draw. At the laboratory site, T cells derived from blood samples are tested for reactivity against a panel of peptides derived from common human allergens. IMMUNOCAT stores results from these T cell assays along with MHC:peptide binding data, results from RAST tests for antibody titers in donor serum, and the respective donor HLA typing results. Through this system, we are able to perform queries and integrated analyses of the various types of data. This provides a case study for the use of bioinformatics and information management techniques to track and analyze data produced in a translational research study aimed at epitope identification
An ontology for immune epitopes: application to the design of a broad scope database of immune reactivities
BACKGROUND: Epitopes can be defined as the molecular structures bound by specific receptors, which are recognized during immune responses. The Immune Epitope Database and Analysis Resource (IEDB) project will catalog and organize information regarding antibody and T cell epitopes from infectious pathogens, experimental antigens and self-antigens, with a priority on NIAID Category A-C pathogens () and emerging/re-emerging infectious diseases. Both intrinsic structural and phylogenetic features, as well as information relating to the interactions of the epitopes with the host's immune system will be catalogued. DESCRIPTION: To effectively represent and communicate the information related to immune epitopes, a formal ontology was developed. The semantics of the epitope domain and related concepts were captured as a hierarchy of classes, which represent the general and specialized relationships between the various concepts. A complete listing of classes and their properties can be found at . CONCLUSION: The IEDB's ontology is the first ontology specifically designed to capture both intrinsic chemical and biochemical information relating to immune epitopes with information relating to the interaction of these structures with molecules derived from the host immune system. We anticipate that the development of this type of ontology and associated databases will facilitate rigorous description of data related to immune epitopes, and might ultimately lead to completely new methods for describing and modeling immune responses
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