Bench-to-bedside review: Erythropoietin and its derivatives as therapies in critical care

Author can archive publisher's pdf. Free via Creative Commons: CC-BENCHTOBEDSIDE-2.0. © 2012 BioMed Central Ltd

Investigating microstructural variation in the human hippocampus using non-negative matrix factorization

In this work we use non-negative matrix factorization to identify patterns of microstructural variance in the human hippocampus. We utilize high-resolution structural and diffusion magnetic resonance imaging data from the Human Connectome Project to query hippocampus microstructure on a multivariate, voxelwise basis. Application of non-negative matrix factorization identifies spatial components (clusters of voxels sharing similar covariance patterns), as well as subject weightings (individual variance across hippocampus microstructure). By assessing the stability of spatial components as well as the accuracy of factorization, we identified 4 distinct microstructural components. Furthermore, we quantified the benefit of using multiple microstructural metrics by demonstrating that using three microstructural metrics (T1-weighted/T2-weighted signal, mean diffusivity and fractional anisotropy) produced more stable spatial components than when assessing metrics individually. Finally, we related individual subject weightings to demographic and behavioural measures using a partial least squares analysis. Through this approach we identified interpretable relationships between hippocampus microstructure and demographic and behavioural measures. Taken together, our work suggests non-negative matrix factorization as a spatially specific analytical approach for neuroimaging studies and advocates for the use of multiple metrics for data-driven component analyses

Significance of foundation-soil separation in dynamic soil-structure interaction

THe dynamic response of flexible surface strip-foundations allowed to uplift is numerically obtained for externally applied forces of a transient time variation. The soil medium is represented by an isotropic, homogeneous and linear half-space. The soil is treated by a time domain boundary element method, while the flexible foundation is treated by the finite element method. It was concluded that intermediate relative stiffness leads to moderate deformations when uplift is permitted. Very flexible footings produce higher deformations in unilateral contact compared to bilateral contact, and thus should be considered in their design. Unilateral contact does not significantly increase deformations for stiff footings subjected to concentrated central loading. However, relatively large deformation differences occur when the loading is eccentric, necessitating consideration of uplift in their design

Tissue plasminogen activator dose and pulmonary artery pressure reduction in catheter directed thrombolysis of submassive pulmonary embolism.

PURPOSE:The purpose of this study is to assess the incremental effect of tissue plasminogen activator (t-PA) dose on pulmonary artery pressure (PAP) and bleeding during catheter directed thrombolysis (CDT) of submassive pulmonary embolism (PE). MATERIALS AND METHODS:Records of 46 consecutive patients (25 men, 21 women, mean age 55±14 y) who underwent CDT for submassive PE between September 2009 and February 2017 were retrospectively reviewed. Mean t-PA rate was 0.7±0.3 mg/h. PAP was measured at baseline and daily until CDT termination. Mixed-effects regression modeling was performed of repeated PAP measures in individual patients. Bleeding events were classified by Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO) and t-PA dose at onset. RESULTS:Mean t-PA dose was 43.0±30.0 mg over 61.9± 28.8 h. Mean systolic PAP decreased from 51.7±15.5 mmHg at baseline to 35.6±12.7 mmHg at CDT termination (p<0.001). Mixed-effects regression revealed a linear decrease in systolic PAP over time (β = -0.37 (SE = 0.05), p<0.001) with reduction in mean systolic PAP to 44.8±1.9 mmHg at 12 mg t-PA/20 h, 39.5±2.0 mmHg at 24 mg t-PA/40 h, and 34.9±2.1 mmHg at 36 mg/60 h. No severe, one moderate, and 8 mild bleeding events occurred; bleeding onset was more frequent at ≤24 mg t-PA (p <0.001). One patient expired from cardiopulmonary arrest after 16 h of CDT (15.4 mg t-PA); no additional intra-procedural fatalities occurred. CONCLUSION:Increased total t-PA dose and CDT duration were associated with greater PAP reduction without increased bleeding events

Are Galaxies Optically Thin to Their Own Lyman Continuum Radiation? II. NGC 6822

Halpha and UBV photometry of NGC 6822 are used to study the distribution of OB stars and HII regions in the galaxy and to determine whether individual regions of the galaxy are in a state of ionization balance. Four distinct components of the Halpha emission (bright, halo, diffuse and field) differentiated by their surface brightnesses are identified. We find that approximately 1/2 of all OB stars in NGC 6822 are located in the field while only 1/4 are found in the combined bright and halo regions, suggesting that OB stars spend roughly 3/4 of their lifetimes outside ``classical'' H II regions. Comparing the observed Halpha emission with that predicted from stellar ionizing flux models, we find that although the bright, halo and diffuse regions are probably in ionization balance, the field region is producing at least 6 times as much ionizing flux as is observed. The ionization balance results in NGC 6822 suggest that star formation rates obtained from Halpha luminosities must underestimate the true star formation rate in this galaxy by about 50%. Comparing our results for NGC 6822 with previous results for the spiral galaxy M33, we find that the inner kiloparsec of M33 is in a more serious state of ionization imbalance, perhaps due to its higher surface density of blue stars.Comment: Replaced version should now compile with standard aastex style files. 28 pages, aastex preprint format. Accepted in ApJ. Hardcopies of figures available on request to [email protected]

Measuring access: how accurate are patient-reported waiting times?

Introduction: A national audit of waiting times in England’s genitourinary medicine clinics measures patient access. Data are collected by patient questionnaires, which rely upon patients’ recollection of first contact with health services, often several days previously. The aim of this study was to assess the accuracy of patient-reported waiting times. Methods: Data on true waiting times were collected at the time of patient booking over a three-week period and compared with patient-reported data collected upon clinic attendance. Factors contributing to patient inaccuracy were explored. Results: Of 341 patients providing initial data, 255 attended; 207 as appointments and 48 ‘walk-in’. The accuracy of patient-reported waiting times overall was 52% (133/255). 85% of patients (216/255) correctly identified themselves as seen within or outside of 48 hours. 17% of patients (17/103) seen within 48 hours reported a longer waiting period, whereas 20% of patients (22/108) reporting waits under 48 hours were seen outside that period. Men were more likely to overestimate their waiting time (10.4% versus 3.1% p<0.02). The sensitivity of patient-completed questionnaires as a tool for assessing waiting times of less than 48 hours was 83.5%. The specificity and positive predictive value were 85.5% and 79.6%, respectively. Conclusion: The overall accuracy of patient reported waiting times was poor. Although nearly one in six patients misclassified themselves as being seen within or outside of 48 hours, given the under and overreporting rates observed, the overall impact on Health Protection Agency waiting time data is likely to be limited

Urban heritage conservation and rapid urbanization : insights from Surat, India

Currently, heritage is challenged in the Indian city of Surat due to diverse pressures,  including rapid urbanization, increasing housing demand, and socio‐cultural and climate changes.  Where rapid demographic growth of urban areas is happening, heritage is disappearing at an  alarming rate. Despite some efforts from the local government, urban cultural heritage is being  neglected and historic buildings keep being replaced by ordinary concrete buildings at a worryingly  rapid pace. Discussions of challenges and issues of Surat’s urban area is supported by a qualitative  dataset, including in‐depth semi‐structured interviews and focus groups with local policy makers,  planners, and heritage experts, triangulated by observation and a photo‐survey of two historic  areas. Findings from this study reveal a myriad of challenges such as: inadequacy of urban  conservation management policies and processes focused on heritage, absence of skills, training,  and resources amongst decision makers and persistent conflict and competition between heritage  conservation needs and developers’ interests. Furthermore, the values and significance of Surat’s  tangible and intangible heritage is not fully recognized by its citizens and heritage stakeholders. A  crucial opportunity exists for Surat to maximize the potential of heritage and reinforce urban  identity for its present and future generations. Surat’s context is representative of general trends  and conservation challenges and therefore recommendations developed in this study hold the  potential to offer interesting insights to the wider planners and conservationists’ international  community.  This  paper  recommends  thoughtful  integration  of  sustainable  heritage  urban  conservation into local urban development frameworks and the establishment of approaches that  recognize the plurality of heritage values