153 research outputs found
Indistinguishable Encoding for Bidirectional Quantum Key Distribution: Theory to Experiment
We present for the first time, a bidirectional Quantum Key Distribution
protocol with minimal encoding operations derived from the use of two
`nonorthogonal' unitary transformations selected from two mutually unbiased
unitary bases; which are indistinguishable in principle for a single use. Along
with its decoding procedure, it is a stark contrast to its `orthogonal
encoding' predecessors. Defining a more relevant notion of security threshold
for such protocols, the current protocol outperforms its predecessor in terms
of security as the maximal amount of information an eavesdropper can glean is
essentially limited by the indistinguishability of the transformations. We
further propose adaptations for a practical scenario and report on a proof of
concept experimental scheme based on polarised photons from an attenuated
pulsed laser for qubits, demonstrating the feasibility of such a protocol.Comment: 9 pages, 3 figure
Blind encoding into qudits
We consider the problem of encoding classical information into unknown qudit
states belonging to any basis, of a maximal set of mutually unbiased bases, by
one party and then decoding by another party who has perfect knowledge of the
basis. Working with qudits of prime dimensions, we point out a no-go theorem
that forbids shift operations on arbitrary unknown states. We then provide the
necessary conditions for reliable encoding/decoding.Comment: To appear in Physics Letters
Entropic bounds as uncertainty measure of unitary operators
We reformulate the notion of uncertainty of pairs of unitary operators within the context of guessing games and derive an entropic uncertainty relation for a pair of such operators. We show how distinguishable operators are compatible while maximal incompatibility of unitary operators can be connected to bases for some subspace of operators which are mutually unbiased
Magnetoresistive and magnetic properties of La0.67A0.33MnO3 (A= Ba, Ca, and Sr) prepared by co-precipitation method.
We have prepared perovskite structured La0.67A0.33MnO3 manganite (A = Ba, Ca and Sr) using co-precipitation method. The samples were characterized using x-ray
diffraction (XRD) and scanning electron microscope (SEM) to identify the structure and microstructure. The magnetic and magnetoresistance properties were measured by vibrations sample magnetometer (VSM) and four point probe methods. From the XRD spectrum, samples are in single phase pervoskite structure where LBMO and LCMO showed orthorhombic whereas LSMO has rhombohedral phase. LSMO has average grain size range of 0.5μm -2.5μm. However, for LBMO and LCMO, the grain boundaries are not well define and connected. The difference in the microstructure image might be due to the different activation energy and variance A-site cation that differs in grain growth. The Curie temperature of LBMO and LSMO are 343K and 371K, respectively. LCMO system gives the highest CMR value (-10.1% at 1 tesla) at room temperature. A significantly low field magnetoresistance effect (LFMR) which is
-13.9% (at 0.1T, 90K) has been observed in LBMO and this LFMR effect is believed to be due to the disorder layers at the grain boundaries in the samples
Investigating the Association between Physical Health Comorbidities and Disability in Individuals with Severe Mental Illness
BACKGROUND: Research suggests that an increased risk of physical comorbidities might have a key role in the association between severe mental illness (SMI) and disability. We examined the association between physical multimorbidity and disability in individuals with SMI. METHODS: Data were extracted from the clinical record interactive search system at South London and Maudsley Biomedical Research Centre. Our sample (n = 13,933) consisted of individuals who had received a primary or secondary SMI diagnosis between 2007 and 2018 and had available data for Health of Nations Outcome Scale (HoNOS) as disability measure. Physical comorbidities were defined using Chapters II–XIV of the International Classification of Diagnoses (ICD-10). RESULTS: More than 60 % of the sample had complex multimorbidity. The most common organ system affected were neurological (34.7%), dermatological (15.4%), and circulatory (14.8%). All specific comorbidities (ICD-10 Chapters) were associated with higher levels of disability, HoNOS total scores. Individuals with musculoskeletal, skin/dermatological, respiratory, endocrine, neurological, hematological, or circulatory disorders were found to be associated with significant difficulties associated with more than five HoNOS domains while others had a lower number of domains affected. CONCLUSIONS: Individuals with SMI and musculoskeletal, skin/dermatological, respiratory, endocrine, neurological, hematological, or circulatory disorders are at higher risk of disability compared to those who do not have those comorbidities. Individuals with SMI and physical comorbidities are at greater risk of reporting difficulties associated with activities of daily living, hallucinations, and cognitive functioning. Therefore, these should be targeted for prevention and intervention programs
Low-field magnetoresistive and magnetic properties in (La1-xErx)0.67Sr0.33MnO3 manganites perovskite.
Polycrystalline manganites of (La1-xErx)0.67Sr0.33MnO3 (x=0.00, 0.05 and 0.10) had been prepared by conventional solid-state reaction method. X-ray diffraction analysis
confirms that all samples are in single phase with distorted perovskite rhombohedral structure. Scanning electron microscope shows that small amount of Er substitution in La site affect the grain formation and this might affect the grain boundaries layer which resulting the reduction of Tc. All sample shows quite similar Low-field
magnetoresistance (MR) effect with a large negative MR at low field (0-0.1T) region followed by a slower varying MR at high field (0.1-1T) region. The highest low-field
MR value of -3% (at 0.1T, 300K) and high-field MR value of -8.3% (at 1T, 300K) are observed for sample X=0.10
Minimally invasive application of botulinum toxin A in patients with idiopathic rhinitis
<p>Abstract</p> <p>Background</p> <p>Nasal hypersecretion due to idiopathic rhinitis can often not be treated sufficiently by conventional medication. Botulinum toxin A (BTA) has been injected into the nasal mucosa in patients with nasal hypersecretion with a reduction of rhinorrhea lasting for about 4 to 8 weeks. Since the nasal mucosa is well supplied with glands and vessels, the aim of this study was to find out if the distribution of BTA in the nasal mucosa and a reduction of nasal hypersecretion can also be reached by a minimally invasive application by sponges without an injection.</p> <p>Methods</p> <p>Patients were randomly divided into two groups. The effect of BTA (group A, C, D) or saline as placebo (group B) was investigated in 20 patients with idiopathic rhinitis by applying it with a sponge soaked with BTA (40 units each nostril) or saline. Subgroups C and D contained these patients of group A and B who did not improve in symptoms one week after the original treatment (either BTA or saline) who then received the alternative medication. Changes of symptoms (rhinorrhea, nasal obstruction) were scored by the patients in a four point scale and counted (consumption of tissues, sneezing) in a diary. The patients were followed up weeks 1, 2, 4, 8 and 12.</p> <p>Results</p> <p>There was a clear reduction of the amount of secretion in group A compared to group B, C and D. This did not correlate with the tissue consumption, which was comparably reduced in group A and B, but reduced less in group C and D. Sneezing was clearly reduced in group A but comparably unchanged in group B and C and increased in group D. Nasal congestion remained unchanged.</p> <p>Conclusion</p> <p>In some patients with therapy-resistant idiopathic rhinitis BTA applied with a sponge is a long-lasting and minimal invasive therapy to reduce nasal hypersecretion.</p
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