The Burden of Cognitive Impairment in Patients With End-Stage Renal Disease and Impact on Dialysis Modality Choice

IntroductionKidney disease is associated with significant cognitive dysfunction. Subjective reports of cognitive ability have not been studied extensively in chronic kidney disease. We investigated the association between objective and subjective cognitive functions in predialysis patients and their association with self-care dialysis modality choice.MethodsCross-sectional data from the Barriers to Successful Implementation of Care in Home Haemodialysis study were used for the study of cognition in 220 predialysis patients. The data were used to ascertain the demographics, clinical, laboratory, and neuropsychometric variables. The latter includes Trail Making Tests (TMT) parts A and B, Modified Mini Mental State Examination, and metacognition questionnaire for subjective assessment of one’s cognitive ability. The outcome variable was fully assisted and self-care dialysis modality choice.ResultsWithin the study cohort, 90 patients chose fully assisted hemodialysis and 114 patients chose self-care dialysis. The median Modified Mini Mental State Examination, TMT part A, and TMT part B scores were greater for the assisted versus the self-care group. Metamemory was not significantly different between groups, but the metaconcentration score was significantly worse in the group choosing assisted dialysis. Higher (i.e., better) metaconcentration scores were significantly associated with the self-care modality choice in the univariate and hierarchical regression analyses. Adjusted and unadjusted analyses showed a significant association between perceived concentration and TMT part B scores (P < 0.01). With every 1.6-minute increase in TMT part B score, there was a 1-unit reduction in metaconcentration score, and the latter was associated with 20% lower odds of choosing self-care dialysis over a fully assisted dialysis modality.DiscussionPatients’ self-perception of cognitive ability is a significant predictor of self-care dialysis modality choice. Subjective report of “metaconcentration” is also strongly associated with poorer outcome on the TMT part B

Diagnosis of asthma in symptomatic children based on measures of lung function: an analysis of data from a population-based birth cohort study.

BACKGROUND: Concerns have been expressed about asthma overdiagnosis. The UK National Institute of Health and Care Excellence (NICE) proposed a new diagnostic algorithm applying four lung function measures sequentially (ratio of forced expiratory volume in 1 s [FEV1] to forced vital capacity [FVC] 20%). We aimed to assess the diagnostic value of three of the tests individually, and then test the proposed algorithm in symptomatic children. METHODS: We used follow-up data at age 13-16 years from the Manchester Asthma and Allergy Study, a prospective, population-based, birth cohort study. We initially present results for the whole population, then by subgroup of disease. To simulate the situation in primary care, we included participants reporting symptoms of wheeze, cough, or breathlessness in the previous 12 months and who were not on regular inhaled corticosteroids. We used an epidemiological definition of current asthma, defined as all three of physician-diagnosed asthma, current wheeze, and current use of asthma treatment, reported by parents in a validated questionnaire. We assigned children with negative answers to all three questions as non-asthmatic controls. We also measured spirometry, bronchodilator reversibility, and FeNO at follow-up; data for peak expiratory flow variability were not available. We calculated the proportion of participants with a current positive lung function test at each step of the algorithm, and recorded the number of participants that met our definition of asthma. FINDINGS: Of 1184 children born into the cohort, 772 attended follow-up at age 13-16 years between July 22, 2011, and Nov 11, 2014. Among 630 children who completed spirometry, FEV1:FVC was less than 70% in ten (2%) children, of whom only two (20%) had current asthma. Bronchodilator reversibility was positive in 54 (9%) of 624 children, of whom only 12 (22%) had current asthma. FeNO was 35 or more parts per billion in 115 (24%) of 485 children, of whom 29 (25%) had current asthma. Only four of 56 children with current asthma had positive results for all three tests (spirometry, bronchodilator reversibility, and FeNO). Conversely, 24 (43%) of the 56 children with current asthma were negative on all three tests. FEV1:fvc (p=0·0075) and FeNO (p<0·0001), but not bronchodilator reversibility (p=0·97), were independently associated with asthma in multivariable logistic regression models. Among children who reported recent symptoms, the diagnostic accuracy of the algorithm was poor. INTERPRETATION: Our findings challenge the proposed cutoff values for spirometry, the order in which the lung function tests are done, and the position of bronchodilator reversibility within the algorithm sequence. Until better evidence is available, the proposed NICE algorithm on asthma diagnosis should not be implemented in children. FUNDING: UK Medical Research Council

Suitability versus fidelity for rating single-photon guns

The creation of specified quantum states is important for most, if not all, applications in quantum computation and communication. The quality of the state preparation is therefore an essential ingredient in any assessment of a quantum-state gun. We show that the fidelity, under the standard definitions is not sufficient to assess quantum sources, and we propose a new measure of suitability that necessarily depends on the application for the source. We consider the performance of single-photon guns in the context of quantum key distribution (QKD) and linear optical quantum computation. Single-photon sources for QKD need radically different properties than sources for quantum computing. Furthermore, the suitability for single-photon guns is discussed explicitly in terms of experimentally accessible criteria.Comment: 4 pages, 2 figures Revised per referee suggestion

Single-electron transport driven by surface acoustic waves: moving quantum dots versus short barriers

We have investigated the response of the acoustoelectric current driven by a surface-acoustic wave through a quantum point contact in the closed-channel regime. Under proper conditions, the current develops plateaus at integer multiples of ef when the frequency f of the surface-acoustic wave or the gate voltage Vg of the point contact is varied. A pronounced 1.1 MHz beat period of the current indicates that the interference of the surface-acoustic wave with reflected waves matters. This is supported by the results obtained after a second independent beam of surface-acoustic wave was added, traveling in opposite direction. We have found that two sub-intervals can be distinguished within the 1.1 MHz modulation period, where two different sets of plateaus dominate the acoustoelectric-current versus gate-voltage characteristics. In some cases, both types of quantized steps appeared simultaneously, though at different current values, as if they were superposed on each other. Their presence could result from two independent quantization mechanisms for the acoustoelectric current. We point out that short potential barriers determining the properties of our nominally long constrictions could lead to an additional quantization mechanism, independent from those described in the standard model of 'moving quantum dots'.Comment: 25 pages, 12 figures, to be published in a special issue of J. Low Temp. Phys. in honour of Prof. F. Pobel

Relationships between speed, change of direction and jump performance with cricket specific speed tests in male academy cricketers

Objectives: The aim of this study was to investigate the relationships between general speed and change of direction speed and‘cricket specific’ speed tests and the relationships between jump performance and speed and change of direction ability in male academy cricketers. Design and Methods: Sixteen academy male cricketers (age: 17 ± 0.7 years; height: 176.9 ± 6.2 cm; mass: 72.2 ± 13.2 kg) performed tests of 20 m sprint, 505 change of direction (COD) on both left and right legs, “quick single” with bat (WB) (17.68m), running-a-two WB, running-a-three WB, countermovement jump (CMJ), and drop jump (DJ). Results: Intra-class correlation coefficients (ICC’s) revealed high within-session reliability for all tests (ICC ≥ 0.92; p ≤ 0.001),except 0-5 m (ICC = 0.642; p ≤ 0.001) and 0-10 m (ICC = 0.708; p ≤ 0.001) tests. General speed tests showed strong relationships to ‘cricket specific’ speed tests (20 m sprint - running-a-two; r = 0.951; p ≤ 0.01; 20 m sprint - running-a-three; r = 0.937; p ≤ 0.01; ‘quick single’; r = 0.951; p ≤ 0.01). Strong relationships were also observed between the 505 right foot COD times and all cricket specific tests (r = 0.909- 0.934; p ≤ 0.01). CMJ height showed the strongest correlations with: 20 m (r = -0.668;p ≤ 0.01); 505 left (r = -0.789; p ≤ 0.01); 505 right (r = -0.807; p ≤ 0.01); “quick single” WB (r = -0.739; p ≤ 0.01); running-a two WB (r = -0.742; p ≤ 0.01); running-a-three (WB) (r = -0.733; p ≤ 0.01). Conclusions: The findings suggest that general speed and COD tests are highly appropriate to assess cricket specific qualities in youth cricketers