1,078 research outputs found
Optimal universal and state-dependent quantum cloning
We establish the best possible approximation to a perfect quantum cloning machine that produces two clones out of a single input. We analyze both universal and state-dependent cloners. The maximal fidelity of cloning is shown to be 5/6 for universal cloners. It can be achieved either by a special unitary evolution or by a teleportation scheme. We construct the optimal state-dependent cloners operating on any prescribed two nonorthogonal states and discuss their fidelities and the use of auxiliary physical resources in the process of cloning. The optimal universal cloners permit us to derive an upper bound on the quantum capacity of the depolarizing quantum channel
Optimal eavesdropping in quantum cryptography with six states
A generalization of the quantum cryptographic protocol by Bennett and
Brassard is discussed, using three conjugate bases, i.e. six states. By
calculating the optimal mutual information between sender and eavesdropper it
is shown that this scheme is safer against eavesdropping on single qubits than
the one based on two conjugate bases. We also address the question for a
connection between the maximal classical correlation in a generalized Bell
inequality and the intersection of mutual informations between sender/receiver
and sender/eavesdropper.Comment: 4 pages, 1 figur
Kontrolle bodenbürtiger Krankheiten des Fußkrankheits-komplexes an Erbsen mit Komposten
Soil borne diseases are highly important in organic grain legumes. Suppressive composts are an important measure to control soil borne pathogens in different crops. So far, reports on the foot rot causing pathogens in peas such as Fusarium spp., Phoma medicaginis, Mycospherella pinodes are rare. In our study Phoma medicaginis, Pythium ultimum and Fusarium avenaceum were significantly controlled with yard waste composts demonstrating the principal potential of composts to suppress these diseases. However, the main challenge for organic farmers are to transfer these results to the practise in organic farms. In a field trial with peas 5 and 18 t/ha of compost were applied as broadcast or as strip application while sowing peas with a new developed sowing machine with special tools for strip application of composts. It was shown that the strip application supplying high amounts of composts suppressed the foot rot complex of peas significantly in comparison to the broadcast or the un-amended control plots. Strip application of composts were superior over the broadcast application throughout the season
Optimal Universal and State-Dependent Quantum Cloning
We establish the best possible approximation to a perfect quantum cloning
machine which produces two clones out of a single input. We analyze both
universal and state-dependent cloners. The maximal fidelity of cloning is shown
to be 5/6 for universal cloners. It can be achieved either by a special unitary
evolution or by a novel teleportation scheme. We construct the optimal
state-dependent cloners operating on any prescribed two non-orthogonal states,
discuss their fidelities and the use of auxiliary physical resources in the
process of cloning. The optimal universal cloners permit us to derive a new
upper bound on the quantum capacity of the depolarizing quantum channel.Comment: 30 pages (RevTeX), 2 figures (epsf), further results and further
authors added, to appear in Physical Review
Phase covariant quantum cloning
We consider an N -> M quantum cloning transformation acting on pure two-level
states lying on the equator of the Bloch sphere. An upper bound for its
fidelity is presented, by establishing a connection between optimal phase
covariant cloning and phase estimation. We give the explicit form of a cloning
transformation that achieves the bound for the case N=1, M=2, and find a link
between this case and optimal eavesdropping in the quantum cryptographic scheme
BB84.Comment: 9 pages, 1 figur
Effects of black tea on body composition and metabolic outcomes related to cardiovascular disease risk: a randomized controlled trial
This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (http://creativecommons.org/licenses/by/3.0/)There is increasing evidence that tea and its non-caffeine components (primarily flavonoids) contribute to
cardiovascular health. Randomized controlled trials have shown that tea can improve cardiovascular
disease risk factors. We have previously reported a non-caffeine associated beneficial effect of regular
black tea consumption on blood pressure and its variation. Objective: To explore the non-caffeine
associated effects of black tea on body weight and body fat distribution, and cardiovascular disease related
metabolic outcomes. Design: regular tea-drinking men and women (n ¼ 111; BMI 20–35 kg m 2) were
recruited to a randomized controlled double-blind 6 month parallel-designed trial. Participants consumed
3 cups per day of either powdered black tea solids (tea) or a flavonoid-free flavour- and caffeine-matched
placebo (control). Body weight, waist- and hip-circumference, endothelial function and plasma biomarkers
were assessed at baseline, 3 months and 6 months. Results: Compared to control, regular ingestion of
black tea over 3 months inhibited weight gain ( 0.64 kg, p ¼ 0.047) and reduced waist circumference
( 1.88 cm, P ¼ 0.035) and waist-to-hip ratio ( 0.03, P ¼ 0.005). These effects were no longer significant
at 6 months. There were no significant effects observed on fasting glucose, insulin, plasma lipids or
endothelial function. Conclusion: Our study suggests that short-term regular ingestion of black tea over 3
months can improve body weight and body fat distribution, compared to a caffeine-matched control
beverage. However, there was no evidence that these effects were sustained beyond 3 months
Mechanisms governing the pioneering and redistribution capabilities of the non-classical pioneer PU.1
Establishing gene regulatory networks during differentiation or reprogramming requires master or pioneer transcription factors (TFs) such as PU.1, a prototype master TF of hematopoietic lineage differentiation. To systematically determine molecular features that control its activity, here we analyze DNA-binding in vitro and genome-wide in vivo across different cell types with native or ectopic PU.1 expression. Although PU.1, in contrast to classical pioneer factors, is unable to access nucleosomal target sites in vitro, ectopic induction of PU.1 leads to the extensive remodeling of chromatin and redistribution of partner TFs. De novo chromatin access, stable binding, and redistribution of partner TFs both require PU.1's N-terminal acidic activation domain and its ability to recruit SWI/SNF remodeling complexes, suggesting that the latter may collect and distribute co-associated TFs in conjunction with the non-classical pioneer TF PU.1
Körnerleguminosen und Bodenfruchtbarkeit - Strategien für einen erfolgreichen Anbau
Der Boden ist eine der wichtigsten Grundlagen unseres Lebens, das erkannte bereits der Bodenkundler und Jurist Friedrich Albert Fallou. Um der großen Bedeutung des Bodens gerecht zu werden, schrieb das „Bundesprogramm Ökologischer Landbau und andere Formen nachhaltiger Landwirtschaft“ (BÖLN*) eine interdisziplinäre Bekanntmachung aus, um praxisnahe Anbaustrategien zu entwickeln, um die Bodenfruchtbarkeit und Pflanzenernährung im Körnerleguminosenanbau zu verbessern. So wurde das interdisziplinäre Bodenfruchtbarkeitsprojekt ins Leben gerufen, in dem Wissenschaft, Beratung und Praxis eng verzahnt waren.
Im Laufe des fünfjährigen Projektes kristallisierten sich viele praxisrelevante Erkenntnisse heraus, die nun in der Praxisbroschüre "Körnerleguminosen und Bodenfruchtbarkeit - Strategien für einen erfolgreichen Anbau" nachgelesen werden können
Prevalence of pain and its associated factors among the oldest-olds in different care settings – results of the AgeQualiDe study
Background; The prevalence of pain is very common in the oldest age group. Managing pain successfully is a key topic in primary care, especially within the ageing population. Different care settings might have an impact on the prevalence of pain and everyday life.
Methods: Participants from the German longitudinal cohort study on Needs, Health Service Use, Costs and Health-related Quality of Life in a large Sample of Oldest-old Primary Care Patients (85+) (AgeQualiDe) were asked to rate their severity of pain as well as the impairment with daily activities. Besides gender, age, education, BMI and use of analgesics we focused on the current housing situation and on cognitive state. Associations of the dependent measures were tested using four ordinal logistic regression models. Model 1 and 4 consisted of the overall sample, model 2 and 3 were divided according to no cognitive impairment (NCI) and mild cognitive impairment (MCI).
Results: Results show a decline in pain at very old age but nonetheless a high prevalence among the 85+ year olds. Sixty-three per cent of the participants report mild to severe pain and 69% of the participants mild to extreme impairment due to pain with daily activities. Use of analgesics, depression and living at home with care support are significantly associated with higher and male gender with lower pain ratings.
Conclusions: Sufficient pain management among the oldest age group is inevitable. Outpatient care settings are at risk of overlooking pain. Therefore focus should be set on pain management in these settings
Changes in Social Network Size Are Associated With Cognitive Changes in the Oldest-Old
Objectives:Social isolation is increasing in aging societies and several studies have shown a relation with worse cognition in old age. However, less is known about the association in the oldest-old (85+); the group that is at highest risk for both social isolation and dementia. Methods:Analyses were based on follow-up 5 to 9 of the longitudinal German study on aging, cognition, and dementia in primary care patients (AgeCoDe) and the study on needs, health service use, costs, and health-related quality of life in a large sample of oldest-old primary care patients (AgeQualiDe), a multi-center population-based prospective cohort study. Measurements included the Lubben Social Network Scale (LSNS-6), with a score below 12 indicating social isolation, as well as the Mini-Mental Status Examination (MMSE) as an indicator of cognitive function. Results:Dementia-free study participants (n = 942) were M = 86.4 (SD = 3.0) years old at observation onset, 68.2% were women. One third (32.3%) of them were socially isolated. Adjusted linear hybrid mixed effects models revealed significantly lower cognitive function in individuals with smaller social networks (β = 0.5, 95% CI = 0.3-0.7, p < .001). Moreover, changes in an individual's social network size were significantly associated with cognitive changes over time (β = 0.2, 95% CI = 0.1-0.4, p = .003), indicating worse cognitive function with shrinking social networks. Conclusion:Social isolation is highly prevalent among oldest-old individuals, being a risk factor for decreases in cognitive function. Consequently, it is important to maintain a socially active lifestyle into very old age. Likewise, this calls for effective ways to prevent social isolation
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