Severe community-acquired and nosocomial pneumonia - a commentary

No Abstrac

The timing and duration of the Delamerian orogeny: Correlation with the Ross Orogen and implications for Gondwana assembly

Copyright © 2006 by the University of Chicago PressThe Antarctic Ross and the Australian Delamerian orogenies are the consequence of stress transfer to the outboard trailing edge of the newly assembled Gondwana supercontinent. This tectonic reorganization occurred in the Early to Middle Cambrian on completion of Pan-African deformation and subduction along the sutures between eastern and western Gondwanan continental fragments. Before this, Neoproterozoic to Early Cambrian rocks in eastern Australia were formed in a passive margin and record dispersion of Rodinia with consequent opening of the proto-Pacific. Our new U-Pb and Rb-Sr geochronology shows that in the South Australian (Adelaide Fold Belt) domain of the Delamerian Orogen, contractional orogenesis commenced at 514 ± 3 Ma and persisted for ∼24 m.yr. until 490 ± 3 Ma, terminated by rapid uplift, cooling, and extension in association with posttectonic magmatism. Integration of new and published U-Pb and 40Ar-39Ar geochronology from the entire Ross-Delamerian belt shows that although both the Delamerian and Ross have a synchronous late magmatic and terminal cooling history, the Ross commenced its convergent orogenic history at ∼540 Ma. This was 25 m.yr. before Delamerian deformation began. During the Early Cambrian, eastern Australia was still in a state of extension (or transtension), with opening of the Kanmantoo Basin and associated anorogenic, largely mafic magmatism. This basin received sediment from the already exposed Ross Orogen to the south. The simultaneous first occurrence of strain fabrics and subduction-related magmatism (including boninite, granite, and andesite lavas) at ∼514 Ma in New Zealand, Victoria, South Australia, New South Wales, and Tasmania implies that the Delamerian Orogeny was driven by ridge-push forces transmitted on the initiation of westward-dipping subduction. Subsequent eastward slab rollback at 490 Ma may have occurred when the new slab had reached the transition zone at 650-km depth, resulting in upper plate extension and anorogenic Basin and Range–style magmatism in South Australia and Tasmania (Mount Read belt). The delayed onset of subduction in the Australian sector of the margin implies that westward motion of the Australian portion of eastern Gondwana continued to be accommodated during the late Early Cambrian by subduction or deformation along either the Mozambique Suture or at the northern end of the South Prince Charles Mountains–Prydz Bay suture.John Foden, Marlina A. Elburg, Jon Dougherty-Page, and Andrew Burt

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

Fano resonances in a three-terminal nanodevice

The electron transport through a quantum sphere with three one-dimensional wires attached to it is investigated. An explicit form for the transmission coefficient as a function of the electron energy is found from the first principles. The asymmetric Fano resonances are detected in transmission of the system. The collapse of the resonances is shown to appear under certain conditions. A two-terminal nanodevice with an additional gate lead is studied using the developed approach. Additional resonances and minima of transmission are indicated in the device.Comment: 11 pages, 5 figures, 2 equations are added, misprints in 5 equations are removed, published in Journal of Physics: Condensed Matte

Advancing characterisation with statistics from correlative electron diffraction and X-ray spectroscopy, in the scanning electron microscope.

The routine and unique determination of minor phases in microstructures is critical to materials science. In metallurgy alone, applications include alloy and process development and the understanding of degradation in service. We develop a correlative method, exploring superalloy microstructures, which are examined in the scanning electron microscope (SEM) using simultaneous energy dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD). This is performed at an appropriate length scale for characterisation of carbide phases' shape, size, location, and distribution. EDS and EBSD data are generated using two different physical processes, but each provide a signature of the material interacting with the incoming electron beam. Recent advances in post-processing, driven by 'big data' approaches, include use of principal component analysis (PCA). Components are subsequently characterised to assign labels to a mapped region. To provide physically meaningful signals, the principal components may be rotated to control the distribution of variance. In this work, we develop this method further through a weighted PCA approach. We use the EDS and EBSD signals concurrently, thereby labelling each region using both EDS (chemistry) and EBSD (crystal structure) information. This provides a new method of amplifying signal-to-noise for very small phases in mapped regions, especially where the EDS or EBSD signal is not unique enough alone for classification

Zircon geochemical and geochronological constraints on contaminated and enriched mantle sources beneath the Arabian Shield, Saudi Arabia

Arabian Shield granitic zircon geochemistry provides insight into the petrogenetic processes involved in generating one of the planet’s largest tracts of juvenile Neoproterozoic crust. New zircon geochemistry supports previous U-Pb and whole-rock data that defined four magmatic groups: (1) ∼870-675 Ma island arc and synorogenic I-type granitoids (IA1Syn), (2) ∼640-585 Ma I-and A-type granitoids from the Nabitah and Halaban Suture (NHSG), (3) ∼610-600 Ma postorogenic perthitic (hypersolvus) A-type granitoids (POPG), and (4) <600 Ma anorogenic aegirine-bearing perthitic (hypersolvus) A-type granitoids (AAPG). The low Nb (∼1-300 ppm) and intrasuite rare earth element variation in IA1Syn and NHSG zircons indicates that these suites are derivatives of contaminated mantle followed by fractionation. AAPG suites, however, have higher Nb content (∼10-400 ppm) and are derived from limited crust-enriched mantle interaction. Each of the IA, Syn, and NHSG suites have discrete granite subsuites distinguished using zircon morphology and geo-chemistry whose U-Pb ages in each case form three groups. The IA subgroups are ∼867, ∼847, and ∼829 Ma; the Syn subgroups are ∼730, 716, and 696 Ma; and the NHSG subgroups are ∼636, ∼610, and ∼594 Ma. This apparent subevent repetition suggests some form of magmatic pulsing in the Arabian Shield. It is suggested that IA1Syn suites reflect typical volcanic arc granite settings and incremental subduction/accretion of eastward-migrating oceanic fragments of the East African Orogen. The appearance of ∼636 Ma A-type magmatism within suture zones (NHSG) is possibly derived from a long-lived (∼50 m.yr.) melting, assimilation, storage, and homogenization (MASH) zone resulting from an ∼640 Ma slab tear. These A-types are distinguished from more-enriched anorogenic (<600 Ma) A-types, possibly associated with lithospheric delamination.F. A. Robinson, J. D. Foden, and A. S. Collin

Prevalence and associated features of depression in women with Rett Syndrome

Background Little is known about depression among women with Rett syndrome (RTT) despite recent advances in knowledge about RTT. In this study, we aimed to establish the prevalence of depression among women with RTT as identified by a screening telephone interview and to explore the clinical factors associated with this. Methods The study employed the cross-sectional analysis of data from telephone interviews with carers of 56 women with RTT, using validated questionnaires for assessing mental health problems, challenging behaviour and RTT severity. Results Scores on the mental health assessment reached the affective/neurotic threshold in eight cases (14.3%). No significant differences were found between those reaching the threshold and those who did not in terms of severity of RTT phenotype, health problems or social circumstances. There was a significant association between screening identified depression and higher lethargy and social withdrawal. Conclusions Screening identified depression was found among a sizeable minority of women with RTT. Further investigation is needed to establish a clinically validated prevalence of depression among this group and to identify behavioural features that would lead to prompt psychiatric assessment

Quantum M\"{u}nchhausen effect in tunneling

It is demonstrated that radiative corrections increase tunneling probability of a charged particle

Matching species traits to projected threats and opportunities from climate change

Peer reviewe