Outcomes of decompression for lumbar spinal canal stenosis based upon preoperative radiographic severity

BACKGROUND: The relationship between severity of preoperative radiographic findings and surgical outcomes following decompression for lumbar degenerative spinal canal stenosis is unclear. Our aim in this paper was to gain insight into this relationship. We determined pre-operative radiographic severity on MRI scans using strict methodological controls and correlated such severity with post-operative outcomes using prospectively collected data. METHODS: Twenty-seven consecutive patients undergoing decompression for isolated degenerative spinal canal stenosis at L4-L5 were included. We measured cross-sectional area on MRI using the technique of Hamanishi. We categorized the severity of stenosis using Laurencin and Lipson's 'Stenosis Ratio'. We determined pre-operative status (prospectively) and post-operative outcomes using Weiner and Fraser's 'Neurogenic Claudication Outcome Score'. We determined patient satisfaction using standardized questionnaires. Each of these is a validated measure. Formal statistical evaluation was undertaken. RESULTS: No patients (0 of 14) with a greater than 50% reduction in cross-sectional area on pre-operative MRI had unsatisfactory outcomes. In contrast, outcomes for patients with less than or equal to 50% reduction in cross-sectional area had unsatifactory outcomes in 6 of 13 cases, with all but one negative outcome having a cross-sectional area reduction between 32% and 47%. CONCLUSION: The findings suggest that there appears to be a relationship between severity of stenosis and outcomes of decompressive surgery such that patients with a greater than 50% reduction in cross sectional area are more likely to have a successful outcome

Rule violation errors are associated with right lateral prefrontal cortex atrophy in neurodegenerative disease

Good cognitive performance requires adherence to rules specific to the task at hand. Patients with neurological disease often make rule violation errors, but the anatomical basis for rule violation during cognitive testing remains debated. The current study examined the neuroanatomical correlates of rule violation (RV) errors made on tests of executive functioning in 166 subjects diagnosed with neurodegenerative disease or as neurologically healthy. Specifically, RV errors were voxel-wisely correlated with gray matter volume derived from high-definition MR images using voxel-based morphometry implemented in SPM2. Latent variable analysis showed that rule violation errors tapped a unitary construct separate from repetition errors. This analysis was used to generate factor scores to represent what is common among rule violation errors across tests. The extracted rule violation factor scores correlated with tissue loss in the lateral middle and inferior frontal gyri and the caudate nucleus bilaterally. When a more stringent control for global cognitive functioning was applied using Mini Mental State Exam scores, only the correlations with the right lateral prefrontal cortex remained significant. These data underscore the importance of right lateral prefrontal cortex in behavioral monitoring and highlight the potential of rule violation error assessment for identifying patients with damage to this region

The close circumstellar environment of the semi-regular S-type star Pi^1 Gruis

We study the close circumstellar environment of the nearby S-type star Pi^1 Gruis using high spatial-resolution, mid-infrared observations from the ESO/VLTI. Spectra and visibilities were obtained with the MIDI interferometer on the VLT Auxiliary Telescopes. The cool M5III giant Beta Gruis was used as bright primary calibrator, and a dedicated spectro-interferometric study was undertaken to determine its angular diameter accurately. The MIDI measurements were fitted with the 1D numerical radiative transfer code DUSTY to determine the dust shell parameters of Pi^1 Gruis. Taking into account the low spatial extension of the model in the 8-9 $\mu$m spectral band for the smallest projected baselines, we consider the possibility of a supplementary molecular shell. The MIDI visibility and phase data are mostly dominated by the spherical 21 mas (694 Rsol) central star, while the extended dusty environment is over-resolved even with the shortest baselines. No obvious departure from spherical symmetry is found on the milliarcsecond scale. The spectro-interferometric observations are well-fitted by an optically thin (tau(dust)<0.01 in the band) dust shell that is located at about 14 stellar radii with a typical temperature of 700 K and composed of 70% silicate and 30% of amorphous alumina grains. An optically thin (tau(mol)<0.1 in the N band) H2O+SiO molecular shell extending from the photosphere of the star up to 4.4 stellar radii with a typical temperature of 1000 K is added to the model to improve the fit in the 8-9 $\mu$m spectral band. We discuss the probable binary origin of asymmetries as revealed by millimetric observations

Measuring organisational readiness for patient engagement (MORE) : an international online Delphi consensus study

Date of Acceptance: 28/01/2015. © 2015 Oostendorp et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise statedWidespread implementation of patient engagement by organisations and clinical teams is not a reality yet. The aim of this study is to develop a measure of organisational readiness for patient engagement designed to monitor and facilitate a healthcare organisation’s willingness and ability to effectively implement patient engagement in healthcarePeer reviewedFinal Published versio

C-20 Cardiorespiratory Fitness Predicts Processing Speed Performance in Urban Latin Americans

Asociado a Proyecto 723-B3-339 (FUNDEVI # 2791-01). Edad, Fase 1: envejecimiento saludable en zonas urbanas y rurales. (EDAD, Phase 1: Healthy Aging in Urban and Rural Areas. EDAD "The Epidemiology and Development of Alzheimer´s Disease)". NIH –Fogarty Grant Number: 1R21TW009665 – 01. Fogarty International Center (FIC), National Institute of Health (NIH). Universidad de Kansas-Universidad de Costa RicaObjective There is evidence that cardiorespiratory fitness (CRF) protects against age-related declines in processing speed (PS), but studies investigating older adults living in low and middle-income countries are lacking. We used data from the Epidemiology and Development of Alzheimer’s Disease (EDAD) study to investigate the role of CRF on PS in older Costa Rican adults. Method 306 community dwelling older adults (mean age = 69) were recruited for a study on cognition and physical fitness. We used a regression model to test the association between CRF and a composite measure of PS (Digit Symbol, Trails A, Block Design, and Stroop Color Naming). Confirmatory factor analysis (CFA) with full information maximum likelihood was conducted in a nested multi-step process on subtest scores. We also compared the strength of the relationship between two measures of CRF: Maximal oxygen uptake (V02 peak) and a latent variable comprised of distance achieved during the 6-minute Walk Test and change in heart rate before and after walking (Modified 6-Minute Walk). Results Higher CRF was significantly associated with PS, and the association remained significant after controlling for age and sex (B = 0.21; p < .001). The strength of the relationship between two measures of CRF was very high, suggesting equivalence of these indices. Conclusions CRF and PS are clinically meaningful therapeutic targets for future prevention trials in Latin America. The modified 6-Minute Walk is an efficient approximation of the gold standard CRF measurement. The cognitive benefits of CRF should be compared to other lifestyle interventions (e.g., diet) to determine the active components of cognitive improvement.Universidad de Costa Rica/[723-B3-339]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP

Impact of social support on cognitive vascular risk factors in latino older adults

póster en conferencia en conferencia anual de National Academy of Neuropsychology 2019, San Diego, Estados Unidos. 13-16 de noviembreObjective: Central Americans have a cardiovascular disease (CVD) health advantage, as they are half as likely to carry CVD as European Americans, despite having an equivalent degree of vascular risk factors (VRFs). We examined the impact of social support on this paradox and the relationship to cognitive decrements among Costa Rican older adults. Methods: We identified predictors of the CVD health advantage (VRFs in the absence of CVD: Heart Attack, MI, Stroke). Hypertension (HTN) and CVD were coded as present or absent based on medical history. Of 315 participants, 146 (46%) had HTN but no CVD, 59 (19%) had CVD, and 110 had neither HTN nor CVD. To estimate ROC curves, we applied canonical discriminant analysis to item groups based on the discipline cluster. The discriminant analysis identified items that maximally differentiated the diagnostic groups in a step-wise fashion. Results: Social support and social engagement were stronger predictors of the health advantage than subjective memory complaints. Social Support was a reliable indicator of CVD health advantage (accuracy = 93%, sensitivity = 93%, specificity = 89%). Social Engagement was a reliable discriminator of diagnostic groups (accuracy = 84%, sensitivity = 88%, specificity =75%) versus subjective memory complaints (accuracy = 79%, sensitivity of 82%, specificity of 74%). Conclusion: Our exploratory analyses suggest that social support is an important predictor of living with VRFs but not developing CVD. Current studies are underway to examine the contribution of these risk factors to the development of dementia and cognitive impairment to maximize cost-effective interventions.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP

The limited importance of size-asymmetric light competition and growth of pioneer species in early secondary forest succession in Vietnam

It is generally believed that asymmetric competition for light plays a predominant role in determining the course of succession by increasing size inequalities between plants. Size-related growth is the product of size-related light capture and light-use efficiency (LUE). We have used a canopy model to calculate light capture and photosynthetic rates of pioneer species in sequential vegetation stages of a young secondary forest stand. Growth of the same saplings was followed in time as succession proceeded. Photosynthetic rate per unit plant mass (Pmass: mol C g−1 day−1), a proxy for plant growth, was calculated as the product of light capture efficiency [Φmass: mol photosynthetic photon flux density (PPFD) g−1 day−1] and LUE (mol C mol PPFD−1). Species showed different morphologies and photosynthetic characteristics, but their light-capturing and light-use efficiencies, and thus Pmass, did not differ much. This was also observed in the field: plant growth was not size-asymmetric. The size hierarchy that was present from the very early beginning of succession remained for at least the first 5 years. We conclude, therefore, that in slow-growing regenerating vegetation stands, the importance of asymmetric competition for light and growth can be much less than is often assumed

Applying human factors principles to alert design increases efficiency and reduces prescribing errors in a scenario-based simulation

OBJECTIVE: To apply human factors engineering principles to improve alert interface design. We hypothesized that incorporating human factors principles into alerts would improve usability, reduce workload for prescribers, and reduce prescribing errors. MATERIALS AND METHODS: We performed a scenario-based simulation study using a counterbalanced, crossover design with 20 Veterans Affairs prescribers to compare original versus redesigned alerts. We redesigned drug-allergy, drug-drug interaction, and drug-disease alerts based upon human factors principles. We assessed usability (learnability of redesign, efficiency, satisfaction, and usability errors), perceived workload, and prescribing errors. RESULTS: Although prescribers received no training on the design changes, prescribers were able to resolve redesigned alerts more efficiently (median (IQR): 56 (47) s) compared to the original alerts (85 (71) s; p=0.015). In addition, prescribers rated redesigned alerts significantly higher than original alerts across several dimensions of satisfaction. Redesigned alerts led to a modest but significant reduction in workload (p=0.042) and significantly reduced the number of prescribing errors per prescriber (median (range): 2 (1-5) compared to original alerts: 4 (1-7); p=0.024). DISCUSSION: Aspects of the redesigned alerts that likely contributed to better prescribing include design modifications that reduced usability-related errors, providing clinical data closer to the point of decision, and displaying alert text in a tabular format. Displaying alert text in a tabular format may help prescribers extract information quickly and thereby increase responsiveness to alerts. CONCLUSIONS: This simulation study provides evidence that applying human factors design principles to medication alerts can improve usability and prescribing outcomes

Collective dynamics of internal states in a Bose gas

Theory for the Rabi and internal Josephson effects in an interacting Bose gas in the cold collision regime is presented. By using microscopic transport equation for the density matrix the problem is mapped onto a problem of precession of two coupled classical spins. In the absence of an external excitation field our results agree with the theory for the density induced frequency shifts in atomic clocks. In the presence of the external field, the internal Josephson effect takes place in a condensed Bose gas as well as in a non-condensed gas. The crossover from Rabi oscillations to the Josephson oscillations as a function of interaction strength is studied in detail.Comment: 18 pages, 2 figure

A Search for Very High-Energy Gamma Rays from the Missing Link Binary Pulsar J1023+0038 with VERITAS

The binary millisecond radio pulsar PSR J1023+0038 exhibits many characteristics similar to the gamma-ray binary system PSR B1259--63/LS 2883, making it an ideal candidate for the study of high-energy non-thermal emission. It has been the subject of multi-wavelength campaigns following the disappearance of the pulsed radio emission in 2013 June, which revealed the appearance of an accretion disk around the neutron star. We present the results of very high-energy gamma-ray observations carried out by VERITAS before and after this change of state. Searches for steady and pulsed emission of both data sets yield no significant gamma-ray signal above 100 GeV, and upper limits are given for both a steady and pulsed gamma-ray flux. These upper limits are used to constrain the magnetic field strength in the shock region of the PSR J1023+0038 system. Assuming that very high-energy gamma rays are produced via an inverse-Compton mechanism in the shock region, we constrain the shock magnetic field to be greater than $\sim$2 G before the disappearance of the radio pulsar and greater than $\sim$10 G afterwards.Comment: 7 pages, 3 figures, accepted for publication in Ap