Catalysis of entanglement and other quantum resources.

In chemistry, a catalyst is a substance which enables a chemical reaction or increases its rate, while remaining unchanged in the process. Instead of chemical reactions,quantum catalysisenhances our ability to convert quantum states into each other under physical constraints. The nature of the constraints depends on the problem under study and can arise, e.g. from energy preservation. This article reviews the most recent developments in quantum catalysis and gives a historical overview of this research direction. We focus on the catalysis of quantum entanglement and coherence, and also discuss this phenomenon in quantum thermodynamics and general quantum resource theories. We review applications of quantum catalysis and also discuss the recent efforts on universal catalysis, where the quantum state of the catalyst does not depend on the states to be transformed. Catalytic embezzling is also considered, a phenomenon that occurs if the catalyst's state can change in the transition.

Is There a Finite Complete Set of Monotones in Any Quantum Resource Theory?

Entanglement quantification aims to assess the value of quantum states for quantum information processing tasks. A closely related problem is state convertibility, asking whether two remote parties can convert a shared quantum state into another one without exchanging quantum particles. Here, we explore this connection for quantum entanglement and for general quantum resource theories. For any quantum resource theory which contains resource-free pure states, we show that there does not exist a finite set of resource monotones which completely determines all state transformations. We discuss how these limitations can be surpassed, if discontinuous or infinite sets of monotones are considered, or by using quantum catalysis. We also discuss the structure of theories which are described by a single resource monotone and show equivalence with totally ordered resource theories. These are theories where a free transformation exists for any pair of quantum states. We show that totally ordered theories allow for free transformations between all pure states. For single-qubit systems, we provide a full characterization of state transformations for any totally ordered resource theory.

Sub-Rayleigh characterization of a binary source by spatially demultiplexed coherent detection.

We investigate theoretically coherent detection implemented simultaneously on a set of mutually orthogonal spatial modes in the image plane as a method to characterize properties of a composite thermal source below the Rayleigh limit. A general relation between the intensity distribution in the source plane and the covariance matrix for the complex field amplitudes measured in the image plane is derived. An algorithm to estimate parameters of a two-dimensional symmetric binary source is devised and verified using Monte Carlo simulations to provide super-resolving capability for a high ratio of signal to detection noise (SNR). Specifically, the separation between two point sources can be meaningfully determined down to SNR-1/2 in the length unit determined by the spatial spread of the transfer function of the imaging system. The presented algorithm is shown to make a nearly optimal use of the measured data in the sub-Rayleigh region.

Catalytic Transformations of Pure Entangled States.

Quantum entanglement of pure states is usually quantified via the entanglement entropy, the von Neumann entropy of the reduced state. Entanglement entropy is closely related to entanglement distillation, a process for converting quantum states into singlets, which can then be used for various quantum technological tasks. The relation between entanglement entropy and entanglement distillation has been known only for the asymptotic setting, and the meaning of entanglement entropy in the single-copy regime has so far remained open. Here we close this gap by considering entanglement catalysis. We prove that entanglement entropy completely characterizes state transformations in the presence of entangled catalysts. Our results imply that entanglement entropy quantifies the amount of entanglement available in a bipartite pure state to be used for quantum information processing, giving asymptotic results an operational meaning also in the single-copy setup.

Lounging with robots--social spaces of residents in care: A comparison trial.

AIMS: To investigate whether robots could reduce resident sleeping and stimulate activity in the lounges of an older persons' care facility. METHODS: Non-randomised controlled trial over a 12-week period. The intervention involved situating robots in low-level and high-dependency ward lounges and a comparison with similar lounges without robots. A time sampling observation method was utilised to observe resident behaviour, including sleep and activities over periods of time, to compare interactions in robot and no robot lounges. RESULTS: The use of robots was modest; overall 13% of residents in robot lounges used the robot. Utilisation was higher in the low-level care lounges; on average, 23% used the robot, whereas in high-level care lounges, the television being on was the strongest predictor of sleep. CONCLUSION: This study found that having robots in lounges was mostly a positive experience. The amount of time residents slept during the day was significantly less in low-level care lounges that had a robot.

Benefits and problems of health-care robots in aged care settings: A comparison trial.

AIM: This study investigated whether multiple health-care robots could have any benefits or cause any problems in an aged care facility. METHOD: Fifty-three residents and 53 staff participated in a non-randomised controlled trial over 12 weeks. Six robots provided entertainment, communication and health-monitoring functions in staff rooms and activity lounges. These settings were compared to control settings without robots. RESULTS: There were no significant differences between groups in resident or staff outcomes, except a significant increase in job satisfaction in the control group only. The intervention group perceived the robots had more agency and experience than the control group did. Perceived agency of the robots decreased over time in both groups. Overall, we received very mixed responses with positive, neutral and negative comments. CONCLUSIONS: The robots had no major benefits or problems. Future research could give robots stronger operational roles, use more specific outcome measures, and perform cost-benefit analyses.

Xanthogranulomatous pyelonephritis: critical analysis of 18 cases from a rural tertiary care centre of India.

Xanthogranulomatous pyelonephritis is an uncommon disorder of the kidney that is characterised by chronic inflammation and extensive destruction of the involved kidney usually associated with renal calculus and obstruction. It commonly involves the middle aged people with an increased incidence among females and diabetic population. Confirmed diagnosis can be done only after histopathological examination of the diseased nephrectomy specimen. So early suspicion and timely intervention is important to reduce the morbidity. In this retrospective study, we analysed the case records of all patients diagnosed with xanthogranulomatous pyelonephritis in our institute over a period of 11 years. A total 18 patients were treated and diagnosed with xanthogranulomatous pyelonephritis from January 2002 to December 2012. Among them 13 were female and 5 male. Most common clinical presentation was flank pain, fever, dysuria and weight loss. Left kidney was affected in 15 cases and right kidney in 3 cases. All patients were having urinary calculus causing obstruction to the pelvicalyceal system of the kidney. Only 2 patients were diabetic. Urine culture was sterile in all patients. All patients were treated with antibiotics, other supportive measures pre-operatively and ultimate nephrectomy having good recovery. Early suspicion and prompt treatment is necessary in minimising morbidity and mortality from the condition.

Genito-urinary tuberculosis in 67 cases: experience from a tertiary core centre in India.

Tuberculosis is very much prevalent in developing countries like India. Genito-urinary tuberculosis usually occurs after 5 to 15 years of the primary lung infection. After lymph node involvement,it is the second common form of extrapulmonary tuberculosis. In this retrospective study, case records of 67 patients diagnosed with genito-urinary tuberculosis in our institute were thoroughly reviewed regarding age, sex, the urogenital organ involved by tuberculosis,mode of diagnosis,and treatment given to the patients. Median age of the patients was 38.5 years, males were more commonly involved than females, kidney was the most common organ involved by tuberculosis followed by ureter and urinary bladder.HIV infection was present in a single patient who had developed tuberculous perinephric abscess. Most common mode of diagnosis was by histopathological examination of the organ involved. Hydronephrosis of the involved kidney with echogenic debris in the dilated pelvicalyceal system on ultrasonography and non-visualised kidney on intravenous urogram was the most common findings on imaging studies who underwent nephrectomy. One patient was seen with tuberculosis of the glans penis which is not much common. Surgical intervention was ablative in nature in most of the cases in the form of nephrectomy. Early diagnosis is important and can prevent the anatomical defor- mity and loss of function of the involved organ.

Contrast induced nephropathy: our experience.

Even in the light of newer and less nephrotoxic contrast media solutions, their increased use during standard and new radiological procedures has resulted in the growing incidence of contrast-induced nephropathy, an iatrogenic disorder caused by exposure to contrast media. This retrospective study was conducted among the patients admitted in North Bengal Medical College from January 2007 to December 2010 with significant rise in serum creatinine level within 48 to 72 hours of systemic administration of contrast media. The study sample constituted 14 patients with mean age being 45.2 years. Among them, 10 patients (71.4%) required haemodialysis. One patient (7.1%) expired after receiving three sessions of haemodialysis. Three patients (21.4%) became dependent on haemodialysis. Once developed, contrast induced nephropathy is associated with high morbidity, long hospital-stay and patient becomes dependent on haemodialysis. Till now, no available current treatment can reverse or ameliorate the condition once it develops. Some precautionary measures taken in the high risk patients before administration of contrast medium is essential to reduce the incidence.