Spectrally Engineering Photonic Entanglement with a Time Lens.

A time lens, which can be used to reshape the spectral and temporal properties of light, requires the ultrafast manipulation of optical signals and presents a significant challenge for single-photon application. In this work, we construct a time lens based on dispersion and sum-frequency generation to spectrally engineer single photons from an entangled pair. The strong frequency anticorrelations between photons produced from spontaneous parametric down-conversion are converted to positive correlations after the time lens, consistent with a negative-magnification system. The temporal imaging of single photons enables new techniques for time-frequency quantum state engineering.

Comprehensive study on the light shielding potential of thermotropic layers for the development of new materials.

In recent years thermotropic overheating protection glazings have been the focus for both solar thermal collector technology and architecture. A thermotropic glazing changes its light transmittance from highly transparent to light diffusing upon reaching a certain threshold temperature autonomously and reversibly. In thermotropic systems with fixed domains (TSFD) the scattering domains are embedded in a polymer matrix, which exhibits a sudden change of the refractive index upon reaching a threshold temperature. The aim of the present study was to comprehensively investigate the light shielding characteristics and potential of TSFD materials by applying simulation of light scattering in particle-filled layers. In random walk simulations a variety of parameters were varied systematically, and the effect on the light transmission behavior of TSFD was studied. The calculation steps of the simulation process are shown in detail. The simulations demonstrate that there is great potential for the production of functional materials with high overheating protection efficiency.

Quantum computing on encrypted data.

The ability to perform computations on encrypted data is a powerful tool for protecting privacy. Recently, protocols to achieve this on classical computing systems have been found. Here, we present an efficient solution to the quantum analogue of this problem that enables arbitrary quantum computations to be carried out on encrypted quantum data. We prove that an untrusted server can implement a universal set of quantum gates on encrypted quantum bits (qubits) without learning any information about the inputs, while the client, knowing the decryption key, can easily decrypt the results of the computation. We experimentally demonstrate, using single photons and linear optics, the encryption and decryption scheme on a set of gates sufficient for arbitrary quantum computations. As our protocol requires few extra resources compared with other schemes it can be easily incorporated into the design of future quantum servers. These results will play a key role in enabling the development of secure distributed quantum systems.

Dispersion-cancelled biological imaging with quantum-inspired interferometry.

Quantum information science promises transformative impact over a range of key technologies in computing, communication, and sensing. A prominent example uses entangled photons to overcome the resolution-degrading effects of dispersion in the medical-imaging technology, optical coherence tomography. The quantum solution introduces new challenges: inherently low signal and artifacts, additional unwanted signal features. It has recently been shown that entanglement is not a requirement for automatic dispersion cancellation. Such classical techniques could solve the low-signal problem, however they all still suffer from artifacts. Here, we introduce a method of chirped-pulse interferometry based on shaped laser pulses, and use it to produce artifact-free, high-resolution, dispersion-cancelled images of the internal structure of a biological sample. Our work fulfills one of the promises of quantum technologies: automatic-dispersion-cancellation interferometry in biomedical imaging. It also shows how subtle differences between a quantum technique and its classical analogue may have unforeseen, yet beneficial, consequences.

[Long-term effects of osteopathic treatment of chronic prostatitis with chronic pelvic pain syndrome: a 5-year follow-up of a randomized controlled trial and considerations on the pathophysiological context]. / Langzeiteffekte osteopathischer Behandlungen bei chronischer Prostatitis/chronischem Beckenschmerzsyndrom : 5-Jahres-Follow-up einer randomisiert kontrollierten Studie und Überlegungen zum pathophysiologischen Kontext.

BACKGROUND: The etiology of chronic prostatitis chronic pelvic pain syndrome (CP/CPPS) is still unclear. As no pathological findings exist the diagnosis of CP/CPPS is essentially a diagnosis by exclusion and functional disorders, so-called somatoform disorders play a more important role. Osteopathy treats functional disorders of the musculoskeletal system including all associated internal organs but little attention has so far been paid to this treatment method. Therefore, the 5-year follow-up period was intended to show that this is a sustainable form of therapy using exclusively manual and gentle techniques and simple treatment procedures resulting in manageable costs. MATERIALS AND METHODS: The aim of this study was to investigate whether sustainability of osteopathic treatment could be demonstrated even after 5 years. This was a randomized controlled study initially involving 5 treatment sessions, a follow-up without treatment after 6 weeks and further follow-up after 1.5 and 5 years. Of the 20 patients 19 in the test group participated in the 5-year follow-up. The control group were not asked because it would have been unacceptable to expect the patients to refrain from having treatment for as long as 5 years. The men were aged between 29 and 70 years. The patients were asked to complete the international prostate symptom score (IPSS), the National Institutes of Health chronic prostatitis symptom index (NIH-CPSI) and the quality of life (QOL) questionnaires once again and in particular to state whether they had received osteopathic treatment specifically for the prostate problem and how often they had been treated. RESULTS: The follow-up assessment of the symptoms of chronic prostatitis (NIH-CPSI) showed that they had further improved after 1.5 years (intragroup difference -1.8 points, 95 % confidence interval CI=-3.8 to 0.3) and also after 5 years (intragroup difference -1.3 points 95 % CI=-3.4 to 0.8). The urinary tract symptoms (IPSS) showed a statistically significant improvement (intergroup difference 8.9 points, 95 % CI=4.7-13.1, p<0.0005). At the second follow-up after 1.5 years there was a further improvement (intragroup difference -2.2 points, 95% CI=-3.9 to -0.4, p=0.02) which was found to remain constant after 5 years (intragroup difference 0.2 points). The quality of life (QOL) with respect to the symptoms showed a statistically significant improvement in comparing both groups during the study phase (intergroup difference χ 2: p<0.005). At follow-up after 5 years out of 19 patients 15 answered the question"how would you feel if the symptoms currently present would not change in the future?" with excellent or satisfactory and 11 patients would not have wanted further osteopathic treatment. Of the patients 8 reported that since the second follow-up (within 3.5 years) they had received osteopathic treatment one to eight times; however, this was partially more prophylactic than due to pain. CONCLUSIONS: Due to the sustainability of osteopathic treatment and the low amount of time involved, osteopathy should be taken seriously as a treatment for patients with CP/CPPS. Furthermore, due to the osteopathic treatment the patients learnt to alleviate or even eliminate their own symptoms in treating themselves. In order to help many other affected persons out of their dilemma it would be desirable if more urologists and internists would become acquainted with osteopathy in order to be able to offer this to patients at an early stage. Further studies with larger numbers of patients should be carried out to confirm these results.

Entanglement-enhanced classical communication over a noisy classical channel.

We present and experimentally demonstrate a communication protocol that employs shared entanglement to reduce errors when sending a bit over a particular noisy classical channel. Specifically, it is shown that given a single use of this channel, one can transmit a bit with higher success probability when the sender and receiver share entanglement compared to the best possible strategy when they do not. The experiment is realized using polarization-entangled photon pairs, whose quantum correlations play a critical role in both the encoding and decoding of the classical message. Experimentally, we find that a bit can be successfully transmitted with probability 0.891±0.002, which is close to the theoretical maximum of (2+2(-1/2))/3≈0.902 and is significantly above the optimal classical strategy, which yields 5/6≈0.833.

Experimental feedback control of quantum systems using weak measurements.

A goal of the emerging field of quantum control is to develop methods for quantum technologies to function robustly in the presence of noise. Central issues are the fundamental limitations on the available information about quantum systems and the disturbance they suffer in the process of measurement. In the context of a simple quantum control scenario-the stabilization of nonorthogonal states of a qubit against dephasing-we experimentally explore the use of weak measurements in feedback control. We find that, despite the intrinsic difficultly of implementing them, weak measurements allow us to control the qubit better in practice than is even theoretically possible without them. Our work shows that these more general quantum measurements can play an important role for feedback control of quantum systems.

[Chronic prostatitis/chronic pelvic pain syndrome. Influence of osteopathic treatment - a randomized controlled study]. / Chronische Prostatitis/chronisches Beckenschmerzsyndrom. Einfluss osteopathischer Behandlungen - eine randomisiert kontrollierte Studie.

BACKGROUND: Prostatitis is the most common urological disease in males under [corrected] the age of 50 years old. As bacteria are detected in only <5% of cases the disease can mostly be classified as chronic nonbacterial prostatitis. The symptoms of this problem complex, often described as chronic prostatitis and chronic pelvic pain syndrome (CP-CPPS), seem to be multifactorial so that an improvement can only rarely be achieved with conventional forms of therapy. MATERIALS AND METHODS: The aim of this study was to investigate whether osteopathic treatment can influence the symptoms of CP-CPPS (randomized controlled study, 5 sessions, follow-up after 6 weeks and 1.5 years without treatment). The study was carried out in a practice for osteopathy. Patients were recruited by referral from urologists, newspaper articles and lectures on the topic. A total of 35 males with medically diagnosed CP-CPPS aged 29-70 years old took part in the study. Of the patients 20 were allocated to the treatment group and 15 to the placebo group whereby 2 patients had to retire from the study prematurely. Patients in the treatment group received 5 osteopathic treatment sessions separated by 1 week at the beginning and by up to 3 weeks at the end (total period 8 weeks). The osteopathic dysfunctions of the patients were treated according to the principles of osteopathy. The placebo treatment in the control group consisted of a training program with simple gymnastic and physiotherapeutic exercises. Improvements of the complaints by urination (LUTS), chronic pelvic pain (CPPS) and quality of life (QOL) were measured using the questionnaires for international prostate symptom score (IPSS), the National Institutes of Health chronic prostatitis symptom index (NIH-CPSI) and the quality of life index (QOL). RESULTS: Comparison of the results from the osteopathy and placebo groups revealed statistically significant differences in favor of the osteopathy group (p<0.0005). During the study period the average IPSS in the osteopathy group improved from 19.7 to 10.3 points (48%, p<0.0005), the NIH from 26.0 to 12.0 (54%; p<0.0005) and the QOL from 4.4 to 1.9 points (58%, p<0.0005). In contrast the corresponding values in the placebo group remained relatively constant. At the follow-up 6 weeks after the last session the improvements in the osteopathy group were found to be stabile and remained so at least up to the second follow-up after 1.5 years. CONCLUSIONS: The positive results of this study indicate that osteopathic treatment can be considered a genuine alternative to the conventional treatment of CP-CPPS and a closer cooperation between urologists/internists and osteopaths would be desirable. Further studies with larger numbers of patients should be carried out to substantiate these results.

Classical analogues of two-photon quantum interference.

Chirped-pulse interferometry (CPI) captures the metrological advantages of quantum Hong-Ou-Mandel (HOM) interferometry in a completely classical system. Modified HOM interferometers are the basis for a number of seminal quantum-interference effects. Here, the corresponding modifications to CPI allow for the first observation of classical analogues to the HOM peak and quantum beating. They also allow a new classical technique for generating phase super-resolution exhibiting a coherence length dramatically longer than that of the laser light, analogous to increased two-photon coherence lengths in entangled states.

[Development of the Saxon Health Target "Active aging - aging in health, autonomy, and participation"]. / Entwicklung des Sächsischen Gesundheitsziels "Aktives Altern - Altern in Gesundheit, Autonomie und Mitverantwortlichkeit."

In Saxony, the consequences of demographic aging are observable already today. To manage the implications on the health sector, the Saxon Health Targets Steering Committee decided in March 2008 to develop a health target "Active Aging - Aging in Health, Autonomy, and Participation". Target development was based on a 7-level approach (fields of action, main goals, target areas, targets, strategies, intervention measures, indicators for evaluation). A quantitative content analysis was used to reveal 10 potential relevant fields of action, three of which were selected for target development. Targets were developed by 53 stakeholders in multiprofessional working groups. Criteria-based analyses were performed to assure appropriate scientific evidence and feasibility of targets and intervention measures. Over a period of 9 months, 24 targets were defined referring to the main goals "needs-based health care structures", "multiprofessional qualification", "self-rated health" and "intergenerational solidarity". Thirteen targets were developed into recommendations for specific intervention measures. Most of the proposed interventions aim to modify health-related structures or psychosocial determinants of health in the elderly. The best recommendations for intervention measures shall be implemented in cooperation with interested decision-makers.

Quantum-optical coherence tomography with classical light.

Quantum-optical coherence tomography (Q-OCT) is an interferometric technique for axial imaging offering several advantages over conventional methods. Chirped-pulse interferometry (CPI) was recently demonstrated to exhibit all of the benefits of the quantum interferometer upon which Q-OCT is based. Here we use CPI to measure axial interferograms to profile a sample accruing the important benefits of Q-OCT, including automatic dispersion cancellation, but with 10 million times higher signal. Our technique solves the artifact problem in Q-OCT and highlights the power of classical correlation in optical imaging.

Cluster-state quantum computing enhanced by high-fidelity generalized measurements.

We introduce and implement a technique to extend the quantum computational power of cluster states by replacing some projective measurements with generalized quantum measurements (POVMs). As an experimental demonstration we fully realize an arbitrary three-qubit cluster computation by implementing a tunable linear-optical POVM, as well as fast active feedforward, on a two-qubit photonic cluster state. Over 206 different computations, the average output fidelity is 0.9832+/-0.0002; furthermore the error contribution from our POVM device and feedforward is only of O(10(-3)), less than some recent thresholds for fault-tolerant cluster computing.

Manipulating biphotonic qutrits.

Quantum information carriers with higher dimension than the canonical qubit offer significant advantages. However, manipulating such systems is extremely difficult. We show how measurement-induced nonlinearities can dramatically extend the range of possible transforms on biphotonic qutrits-three-level quantum systems formed by the polarization of two photons in the same spatiotemporal mode. We fully characterize the biphoton-photon entanglement that underpins our technique, thereby realizing the first instance of qubit-qutrit entanglement. We discuss an extension of our technique to generate qutrit-qutrit entanglement and to manipulate any bosonic encoding of quantum information.

Entanglement generation by Fock-state filtration.

We demonstrate a Fock-state filter which is capable of preferentially blocking single photons over photon pairs. The large conditional nonlinearities are based on higher-order quantum interference, using linear optics, an ancilla photon, and measurement. We demonstrate that the filter acts coherently by using it to convert unentangled photon pairs to a path-entangled state. We quantify the degree of entanglement by transforming the path information to polarization information; applying quantum state tomography we measure a tangle of T=(20+/-9)%.

Time-reversal and super-resolving phase measurements.

We demonstrate phase super-resolution in the absence of entangled states. The key insight is to use the inherent time-reversal symmetry of quantum mechanics: our theory shows that it is possible to measure, as opposed to prepare, entangled states. Our approach is robust, requiring only photons that exhibit classical interference: we experimentally demonstrate high-visibility phase super-resolution with three, four, and six photons using a standard laser and photon counters. Our six-photon experiment demonstrates the best phase super-resolution yet reported with high visibility and resolution.

A pragmatic randomized controlled trial on the effectiveness of low concentrated saline spa water baths followed by ultraviolet B (UVB) compared to UVB only in moderate to severe psoriasis.

OBJECTIVE: To evaluate whether low concentrated saline spa water baths followed by ultraviolet B (LC-SSW-UVB) are superior to UVB alone in moderate to severe psoriasis. BACKGROUND: There is a lack of sufficiently large randomized controlled clinical trial evaluating the additional benefit of saltwater baths followed by UVB compared to UVB only in psoriasis. STUDY DESIGN: Partly evaluator blind, multicentre, pragmatic, randomized controlled trial. SETTING: Five German spa centres. SUBJECTS: One hundred and forty-three adults with stable psoriasis during the last month and a Psoriasis Area and Severity Index (PASI) of > 10 and/or an affected body surface area of > 15%. INTERVENTIONS: LC-SSW-UVB or UVB thrice a week until remission (PASI < 5) or for a maximum of 6 weeks. Sodium chloride concentrations of natural springs varied between 4.5% and 12%. Conventional UVB (broadband UVB or selective UVB phototherapy) was used as irradiation source. MAIN OUTCOME: Reduction of PASI and/or affected body surface area of 50% at the end of the intervention period (PASI-50). Only participants receiving at least one intervention were included in the primary analysis. RESULTS: Patients allocated to LC-SSP-UVB attained a statistically significantly higher rate of PASI-50 at the end of the intervention period than patients allocated to UVB [58/79 (73%) vs. 32/64 (50%); P = 0.01; NNT, 4.3, 95% CI, 2.4-18.1]. Benefit persisted until 3 months only for one of two secondary outcomes considered. CONCLUSIONS: In routine clinical practice balneophototherapy using conventional UVB is superior to conventional UVB only at the end of a 6-week treatment course.

Classical dispersion-cancellation interferometry.

Even-order dispersion cancellation, an effect previously identified with frequency-entangled photons, is demonstrated experimentally for the first time with a linear, classical interferometer. A combination of a broad bandwidth laser and a high resolution spectrometer was used to measure the intensity correlations between anti-correlated optical frequencies. Only 14% broadening of the correlation signal is observed when significant material dispersion, enough to broaden the regular interferogram by 4250%, is introduced into one arm of the interferometer.

Exercise for women receiving adjuvant therapy for breast cancer.

BACKGROUND: A huge clinical research database on adjuvant cancer treatment has verified improvements in breast cancer outcomes such as recurrence and mortality rates. On the other hand, adjuvant therapy with agents such as hormone therapy, chemotherapy and radiotherapy impacts on quality of life due to substantial short- and long-term side effects. OBJECTIVES: To assess the effect of aerobic or resistance exercise interventions during adjuvant treatment for breast cancer on treatment-related side effects such as physical deterioration, fatigue, psychosocial distress and physiological, morphological and biological changes. SEARCH STRATEGY: We searched the Cochrane Breast Cancer Specialised Register (16 July 2004) and the following electronic databases: MEDLINE (1966 to 2006), EMBASE (1988 to 2004), CINAHL (1982 to 2004), SPORTDiscus (1975 to 2004), PsycINFO (1872 to 2003), SIGLE (1880 to 2004), ProQuest Digital Dissertations (1861 to 2004) and Conference Papers Index (1973 to 2004). Furthermore, we screened references in relevant reviews and clinical trials and handsearched relevant journals. SELECTION CRITERIA: We included randomised and non-randomised controlled trials that examined aerobic or resistance exercise, or both, in women undergoing adjuvant treatment for breast cancer. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data and assessed methodological quality and adequacy of the training stimulus following a set of standardised criteria. Meta-analyses were performed for physical fitness, fatigue and weight gain using a random-effects model. MAIN RESULTS: Nine trials involving 452 women met the inclusion criteria. Meta-analysis for cardiorespiratory fitness (involving 207 participants) suggested that exercise improves cardiorespiratory fitness (SMD 0.66, 95% CI 0.20 to 1.12). Meta-analysis for fatigue (317 participants) found statistically non-significant improvements for participants in the exercise intervention groups compared to control (non-exercising) groups (SMD -0.12, 95% CI -0.37 to 0.13); the same applied for the meta-analysis of weight gain (147 participants) (SMD -1.11, 95% CI -2.44 to 0.22). Evidence for other outcomes remains limited. Adverse effects (lymphedema and shoulder tendonitis) were observed in two trials. The results from non-randomised controlled trials are similar to those of randomised controlled trials and do not appear to produce any bias. This review is based on a small number of trials with a considerable degree of clinical heterogeneity regarding adjuvant cancer treatments and exercise interventions. AUTHORS' CONCLUSIONS: Exercise during adjuvant treatment for breast cancer can be regarded as a supportive self-care intervention which results in improved physical fitness and thus the capacity for performing activities of daily life, which may otherwise be impaired due to inactivity during treatment. Improvements in fatigue were ambiguous and there was a lack of evidence for improvement with exercise for other treatment-related side effects. Since exercise interventions (for sedentary participants) require behaviour change, strategies for behaviour change should underpin these interventions. Furthermore, long-term evaluation is required due to possible long-term side effects.

Analyzing the content of outcome measures in clinical trials on irritable bowel syndrome using the international classification of functioning, disability and health as a reference.

BACKGROUND: Patients with irritable bowel syndrome (IBS) report a significant impact of their symptoms on functional health. In outcome assessment of clinical studies on IBS, however, functional aspects other than gastrointestinal symptoms seem to be disregarded to a great extent. AIM: To analyze the content of outcome measures used in clinical IBS trials. METHODS: A systematic review was performed in terms of a quantitative content analysis using the International Classification of Functioning, Disability and Health (ICF) as a coding scheme. Outcome measures were selected from all randomized controlled trials on IBS published in PubMed from the beginning to April 2002. From the outcome measures pre-specified text passages, so-called coding units, were extracted and linked to the ICF. A coding unit had to describe a single health aspect or an internal or external factor with an impact on health. If the outcome measure was a test the goal of the test was semantically implicated. Only second-level ICF categories contained in the outcome assessment of at least 10 % of the studies were considered. All steps of the review were performed by three independent raters. RESULTS: 99 studies were included. Single items were used as outcome measures in 88, clinical and paraclinical tests in 42 and questionnaires in 24 studies. Ninety percent of the coding units (n = 2271) could be linked to the ICF. ICF categories describing gastrointestinal symptoms were considered in the outcome assessment of 37 to 85 studies depending on the type of content compared to extra-gastrointestinal symptoms in 10 to 22 studies. Health information of ICF components other than "body functions" was scarcely included. Clear secular trends for individual ICF categories could not be found. Only a single IBS-specific questionnaire considered health information other than gastrointestinal symptoms. DISCUSSION AND CONCLUSION: Outcome assessment of clinical IBS studies is mainly based on gastrointestinal symptoms. The assessment of other health aspects like comorbid psychological symptoms or social consequences of the disease seems to be similarly important and should be considered in future trials. This would also facilitate the understanding of IBS as a biopsychosocial health condition, both in matters of aetiology and consequences.