Compressed Sensing Performance Analysis via Replica Method using Bayesian framework

Compressive sensing (CS) is a new methodology to capture signals at lower rate than the Nyquist sampling rate when the signals are sparse or sparse in some domain. The performance of CS estimators is analyzed in this paper using tools from statistical mechanics, especially called replica method. This method has been used to analyze communication systems like Code Division Multiple Access (CDMA) and multiple input multi- ple output (MIMO) systems with large size. Replica analysis, now days rigorously proved, is an efficient tool to analyze large systems in general. Specifically, we analyze the performance of some of the estimators used in CS like LASSO (the Least Absolute Shrinkage and Selection Operator) estimator and Zero-Norm regularizing estimator as a special case of maximum a posteriori (MAP) estimator by using Bayesian framework to connect the CS estimators and replica method. We use both replica symmetric (RS) ansatz and one-step replica symmetry breaking (1RSB) ansatz, clamming the latter is efficient when the problem is not convex. This work is more analytical in its form. It is deferred for next step to focus on the numerical results.Comment: The analytical work and results were presented at the 2012 IEEE European School of Information Theory in Antalya, Turkey between the 16th and the 20th of Apri

Mesoscale mapping of sediment source hotspots for dam sediment management in data-sparse semi-arid catchments

Land degradation and water availability in semi-arid regions are interdependent challenges for management that are influenced by climatic and anthropogenic changes. Erosion and high sediment loads in rivers cause reservoir siltation and decrease storage capacity, which pose risk on water security for citizens, agriculture, and industry. In regions where resources for management are limited, identifying spatial-temporal variability of sediment sources is crucial to decrease siltation. Despite widespread availability of rigorous methods, approaches simplifying spatial and temporal variability of erosion are often inappropriately applied to very data sparse semi-arid regions. In this work, we review existing approaches for mapping erosional hotspots, and provide an example of spatial-temporal mapping approach in two case study regions. The barriers limiting data availability and their effects on erosion mapping methods, their validation, and resulting prioritization of leverage management areas are discussed.BMBF, 02WGR1421A-I, GROW - Verbundprojekt SaWaM: Saisonales Wasserressourcen-Management in Trockenregionen: Praxistransfer regionalisierter globaler Informationen, Teilprojekt 1DFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität Berli

Does the availability of a South Asian language in practices improve reports of doctor-patient communication from South Asian patients? Cross sectional analysis of a national patient survey in English general practices.

BACKGROUND: Ethnic minorities report poorer evaluations of primary health care compared to White British patients. Emerging evidence suggests that when a doctor and patient share ethnicity and/or language this is associated with more positive reports of patient experience. Whether this is true for adults in English general practices remains to be explored. METHODS: We analysed data from the 2010/2011 English General Practice Patient Survey, which were linked to data from the NHS Choices website to identify languages which were available at the practice. Our analysis was restricted to single-handed practices and included 190,582 patients across 1,068 practices. Including only single-handed practices enabled us to attribute, more accurately, reported patient experience to the languages that were listed as being available. We also carried out sensitivity analyses in multi-doctor practices. We created a composite score on a 0-100 scale from seven survey items assessing doctor-patient communication. Mixed-effect linear regression models were used to examine how differences in reported experience of doctor communication between patients of different self-reported ethnicities varied according to whether a South Asian language concordant with their ethnicity was available in their practice. Models were adjusted for patient characteristics and a random effect for practice. RESULTS: Availability of a concordant language had the largest effect on communication ratings for Bangladeshis and the least for Indian respondents (p < 0.01). Bangladeshi, Pakistani and Indian respondents on average reported poorer communication than White British respondents [-2.9 (95%CI -4.2, -1.6), -1.9 (95%CI -2.6, -1.2) and -1.9 (95%CI -2.5, -1.4), respectively]. However, in practices where a concordant language was offered, the experience reported by Pakistani patients was not substantially worse than that reported by White British patients (-0.2, 95%CI -1.5,+1.0), and in the case of Bangladeshi patients was potentially much better (+4.5, 95%CI -1.0,+10.1). This contrasts with a worse experience reported among Bangladeshi (-3.3, 95%CI -4.6, -2.0) and Pakistani (-2.7, 95%CI -3.6, -1.9) respondents when a concordant language was not offered. CONCLUSIONS: Substantial differences in reported patient experience exist between ethnic groups. Our results suggest that patient experience among Bangladeshis and Pakistanis is improved where the practice offers a language that is concordant with the patient's ethnicity

Predictive model of blood transfusion during CABG surgery in Pakistan

OBJECTIVE: To determine predictors of need for transfusion of blood and blood products and create a clinical predictive model to reduce indiscriminate use of blood products during surgery. METHOD: We conducted a retrospective chart review of 485 patients who underwent coronary artery bypass surgery from January 2004 to December 2004 at a Tertiary Care Hospital in Karachi, Pakistan. Independent predictors associated with transfusion were identified and a clinical prediction model developed. RESULTS: The transfusion rate was 37.1%. A predictive model was created based on the presence of pulmonary disease, diabetes mellitus, low ejection fraction and recent/ongoing myocardial infarction. CONCLUSION: The study identifies some predictors of need for blood transfusion in patients undergoing Coronary Artery Bypass Grafting. However, prospective studies with a larger sample of patients are needed to determine other predictors and their applicability in patient selection across institutions

Effect of temperature on superconducting nanowire single-photon detector noise

Today Superconducting Nanowire Single-Photon Detectors (SNSPDs) are commonly used in different photon-starved applications, including testing and diagnostics of VLSI circuits. Detecting very faint signals in the near-infrared wavelength range requires not only good detection efficiency, but also very low Dark Count Rate (DCR) and jitter. For example, low noise is crucial to enable ultra-low voltage optical testing of integrated circuits. The effect of detector temperature and background thermal radiation on the noise of superconducting single-photon detectors made of NbN meanders is studied in this paper. It is shown that two different regimes can be identified in the DCR vs. bias current characteristics. At high bias, the dark count rate is dominated by the intrinsic noise of the detector, while at low bias current it is dominated by the detection of stray photons that get onto the SNSPD. Changing the detector temperature changes its switching current and only affects the high bias branch of the characteristics: a reduction of the DCR can be achieved by lowering the SNSPD base temperature. On the other hand, changing the temperature of the single-photon light source (e.g. the VLSI circuit under test) only affects the low bias regime: a lower target temperature leads to a smaller DCR. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.United States. Air Force Research Laboratory. Intelligence Advanced Research Projects Activity (IARPA ) (contract number FA8650-11-C_7105

The deleted in brachydactyly B domain of ROR2 is required for receptor activation by recruitment of Src

The transmembrane receptor 'ROR2' resembles members of the receptor tyrosine kinase family of signalling receptors in sequence but its' signal transduction mechanisms remain enigmatic. This problem has particular importance because mutations in ROR2 are associated with two human skeletal dysmorphology syndromes, recessive Robinow Syndrome (RS) and dominant acting Brachydactyly type B (BDB). Here we show, using a constitutive dimerisation approach, that ROR2 exhibits dimerisation-induced tyrosine kinase activity and the ROR2 C-terminal domain, which is deleted in BDB, is required for recruitment and activation of the non-receptor tyrosine kinase Src. Native ROR2 phosphorylation is induced by the ligand Wnt5a and is blocked by pharmacological inhibition of Src kinase activity. Eight sites of Src-mediated ROR2 phosphorylation have been identified by mass spectrometry. Activation via tyrosine phosphorylation of ROR2 receptor leads to its internalisation into Rab5 positive endosomes. These findings show that BDB mutant receptors are defective in kinase activation as a result of failure to recruit Src

Large-area NbN superconducting nanowire avalanche photon detectors with saturated detection efficiency

Superconducting circuits comprising SNSPDs placed in parallel—superconducting nanowire avalanche photodetectors, or SNAPs—have previously been demonstrated to improve the output signal-to-noise ratio (SNR) by increasing the critical current. In this work, we employ a 2-SNAP superconducting circuit with narrow (40 nm) niobium nitride (NbN) nanowires to improve the system detection efficiency to near-IR photons while maintaining high SNR. Additionally, while previous 2-SNAP demonstrations have added external choke inductance to stabilize the avalanching photocurrent, we show that the external inductance can be entirely folded into the active area by cascading 2-SNAP devices in series to produce a greatly increased active area. We fabricated series-2-SNAP (s2-SNAP) circuits with a nanowire length of 20 μm with cascades of 2-SNAPs providing the choke inductance necessary for SNAP operation. We observed that (1) the detection efficiency saturated at high bias currents, and (2) the 40 nm 2-SNAP circuit critical current was approximately twice that for a 40 nm non-SNAP configuration.United States. Dept. of Defense. Assistant Secretary of Defense for Research & Engineering (United States. Air Force Contract FA8721-05-C-0002