139 research outputs found

    Fluctuations of work in nearly adiabatically driven open quantum systems

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    We extend the quantum jump method to nearly adiabatically driven open quantum systems in a way that allows for an accurate account of the external driving in the system-environment interaction. Using this framework, we construct the corresponding trajectory-dependent work performed on the system and derive the integral fluctuation theorem and the Jarzynski equality for nearly adiabatic driving. We show that such identities hold as long as the stochastic dynamics and work variable are consistently defined. We numerically study the emerging work statistics for a two-level quantum system and find that the conventional diabatic approximation is unable to capture some prominent features arising from driving such as the continuity of the probability density of work. Our results reveal the necessity of using accurate expressions for the drive-dressed heat exchange in future experiments probing jump time distributions.Comment: 15 pages, 5 figure

    Quantifying non-Markovianity due to driving and a finite-size environment in an open quantum system

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    We study non-Markovian effects present in a driven qubit coupled to a finite environment using a recently proposed model developed in the context of calorimetric measurements of open quantum systems. To quantify the degree of non-Markovianity we use the Breuer-Laine-Piilo (BLP) measure [H.-P. Breuer, Phys. Rev. Lett. 103, 210401 (2009)]. We show that information backflow only occurs in the case of driving, in which case we investigate the dependence of memory effects on the environment size, driving amplitude, and coupling to the environment. We show that the degree of non-Markovianity strongly depends on the ratio between the driving amplitude and the coupling strength. We also show that the degree of non-Markovianity does not decrease monotonically as a function of the environment size

    How Many Cooks Spoil the Soup?

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    In this work, we study the following basic question: "How much parallelism does a distributed task permit?" Our definition of parallelism (or symmetry) here is not in terms of speed, but in terms of identical roles that processes have at the same time in the execution. We initiate this study in population protocols, a very simple model that not only allows for a straightforward definition of what a role is, but also encloses the challenge of isolating the properties that are due to the protocol from those that are due to the adversary scheduler, who controls the interactions between the processes. We (i) give a partial characterization of the set of predicates on input assignments that can be stably computed with maximum symmetry, i.e., Θ(Nmin)\Theta(N_{min}), where NminN_{min} is the minimum multiplicity of a state in the initial configuration, and (ii) we turn our attention to the remaining predicates and prove a strong impossibility result for the parity predicate: the inherent symmetry of any protocol that stably computes it is upper bounded by a constant that depends on the size of the protocol.Comment: 19 page

    Eläinavusteinen terapia : Katsaus tutkimuskirjallisuuteen ja toimintaan Suomessa

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    Eläinavusteiset menetelmät ovat ihmisen terveyttä, hyvinvointia ja elämänlaatua edistävää toimintaa, jossa eläimellä on avustava tehtävä. Eläinavusteisessa terapiassa eläin toimii osana tavanomaista terapiaa, jonka tavoitteena on parantaa ihmisen fyysistä, kognitiivista ja sosiaalista toimintakykyä sekä tunnetaitoja. Tässä katsauksessa tavoitteena on tuottaa tietoa eläinavusteisten menetelmien käytöstä Suomessa sekä tarjota kootusti tutkimustietoa eläinavusteisten menetelmien toimivuudesta osana erilaisia terapioita ja kuntoutusprosesseja. Katsauksessa tarkastellaan eläinavusteisen terapian toimivuutta ja hyötyä ja tarpeenmukaisuutta osana kuntoutusprosessia etenkin psykoterapian, puheterapian, fysioterapian ja toimintaterapian näkökulmista. Katsauksen menetelmänä on kartoittava kirjallisuuskatsaus. Tutkimuskirjallisuutta käydään läpi vuosilta 2010–2017 ja kotimaista toimintaa kartoitetaan ammattilaisten ja kuntoutujien haastatteluiden sekä taustoittavien keskustelujen avulla. Lisäksi katsauksen yhteydessä toteutettiin Kelan verkkosivuilla kysely eläinavusteisten menetelmien käytöstä. Katsauksessa esitellään eläinavusteisen terapian hyötyjä ja haittoja sekä tutkimusnäytön että ammattilaisten ja kuntoutujien kokemusten perusteella. Lisäksi esitellään eläinavusteisista menetelmistä hyötyviä kuntoutuksen kohderyhmiä ja kuvaillaan eläimen kanssa työskentelyn toteutustapoja osana erilaisia kuntoutusprosesseja. Katsauksessa käsitellään myös työskentelyyn osallistuvan eläimen edellytyksiä toimia osana terapiaa ja terapeutilta itseltään vaadittavaa täydennyskoulutusta

    The Psoriasis Risk Allele HLA-C*06 : 02 Shows Evidence of Association with Chronic or Recurrent Streptococcal Tonsillitis

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    Pharyngeal tonsillitis is one of the most common upper respiratory tract infections, and group A streptococcus is the most important bacterial pathogen causing it. While most patients experience tonsillitis only rarely, a subset of patients suffers from recurrent or chronic tonsillitis or pharyngitis. The predisposing factors for recurring or chronic forms of this disease are not yet fully understood, but genetic predisposition has been suggested. A genetic association study using Illumina's Immunochip single-nucleotide polymorphism (SNP) array was performed to search for new genetic biomarkers in pharyngeal tonsillitis. More than 100,000 SNPs relevant to immune-mediated diseases were analyzed in a cohort of 95 patients subjected to tonsillectomy due to recurrent/chronic tonsillitis and 504 controls. Genetic association between the cases and controls showed strongest association with two peaks in the HLA locus (odds ratio [OR], 3.7 to 4.7; P = 4.9 x 10(-6) to 5.7 x 10(-6)). Further analysis with imputed classical HLA alleles suggested the known psoriasis risk allele HLA-C*06:02 as a risk factor for tonsillitis (P = 4.8 x 10(-4); OR, 2.3). In addition, the imputed HLA haplotype HLA-C*06:02/HLA-B*57:01, a reported risk haplotype in psoriasis, had the strongest risk for tonsillitis (P = 3.2 x 10(-4); OR, 6.5). These findings further support the previously reported link between streptococcal throat infections and psoriasis.Peer reviewe

    Current knowledge on biomarkers for contact sensitization and allergic contact dermatitis.

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    Contact sensitization is common and affects up to 20% of the general population. The clinical manifestation of contact sensitization is allergic contact dermatitis. This is a clinical expression that is sometimes difficult to distinguish from other types of dermatitis, for example irritant and atopic dermatitis. Several studies have examined the pathogenesis and severity of allergic contact dermatitis by measuring the absence or presence of various biomarkers. In this review, we provide a non-systematic overview of biomarkers that have been studied in allergic contact dermatitis. These include genetic variations and mutations, inflammatory mediators, alarmins, proteases, immunoproteomics, lipids, natural moisturizing factors, tight junctions, and antimicrobial peptides. We conclude that, despite the enormous amount of data, convincing specific biomarkers for allergic contact dermatitis are yet to be described

    Metabolic profiling of fatty liver in young and middle-aged adults : Cross-sectional and prospective analyses of the Young Finns Study

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    Nonalcoholic fatty liver is associated with obesity-related metabolic disturbances, but little is known about the metabolic perturbations preceding fatty liver disease. We performed comprehensive metabolic profiling to assess how circulating metabolites, such as lipoprotein lipids, fatty acids, amino acids, and glycolysis-related metabolites, reflect the presence of and future risk for fatty liver in young adults. Sixty-eight lipids and metabolites were quantified by nuclear magnetic resonance metabolomics in the population-based Young Finns Study from serum collected in 2001 (n = 1,575), 2007 (n = 1,509), and 2011 (n = 2,002). Fatty liver was diagnosed by ultrasound in 2011 when participants were aged 34-49 years (19% prevalence). Cross-sectional associations as well as 4-year and 10-year risks for fatty liver were assessed by logistic regression. Metabolites across multiple pathways were strongly associated with the presence of fatty liver (P <0.0007 for 60 measures in age-adjusted and sex-adjusted cross-sectional analyses). The strongest direct associations were observed for extremely large very-low-density lipoprotein triglycerides (odds ratio [OR] = 4.86 per 1 standard deviation, 95% confidence interval 3.48-6.78), other very-low-density lipoprotein measures, and branched-chain amino acids (e.g., leucine OR = 2.94, 2.51-3.44). Strong inverse associations were observed for high-density lipoprotein measures, e.g., high-density lipoprotein size (OR = 0.36, 0.30-0.42) and several fatty acids including omega-6 (OR = 0.37, 0.32-0.42). The metabolic associations were attenuated but remained significant after adjusting for waist, physical activity, alcohol consumption, and smoking (P <0.0007). Similar aberrations in the metabolic profile were observed already 10 years before fatty liver diagnosis. Conclusion: Circulating lipids, fatty acids, and amino acids reflect fatty liver independently of routine metabolic risk factors; these metabolic aberrations appear to precede the development of fatty liver in young adults. (Hepatology 2017;65:491-500).Peer reviewe
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