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Background: Central neuropathic pain syndromes are a result of central nervous system injury, most commonly related to stroke, traumatic spinal cord injury, or multiple sclerosis. These syndromes are distinctly less common than peripheral neuropathic pain, and less is known regarding the underlying pathophysiology, appropriate pharmacotherapy, and long-term outcomes. The objective of this study was to determine the long-term clinical effectiveness of the management of central neuropathic pain relative to peripheral neuropathic pain at tertiary pain centers. Methods: Patients diagnosed with central (n=79) and peripheral (n=710) neuropathic pain were identified for analysis from a prospective observational cohort study of patients with chronic neuropathic pain recruited from seven Canadian tertiary pain centers. Data regarding patient characteristics, analgesic use, and patient-reported outcomes were collected at baseline and 12-month follow-up. The primary outcome measure was the composite of a reduction in average pain intensity and pain interference. Secondary outcome measures included assessments of function, mood, quality of life, catastrophizing, and patient satisfaction. Results: At 12-month follow-up, 13.5% (95% confidence interval [CI], 5.6-25.8) of patients with central neuropathic pain and complete data sets (n=52) achieved a ≥30% reduction in pain, whereas 38.5% (95% CI, 25.3-53.0) achieved a reduction of at least 1 point on the Pain Interference Scale. The proportion of patients with central neuropathic pain achieving both these measures, and thus the primary outcome, was 9.6% (95% CI, 3.2-21.0). Patients with peripheral neuropathic pain and complete data sets (n=463) were more likely to achieve this primary outcome at 12 months (25.3% of patients; 95% CI, 21.4-29.5) (p=0.012). Conclusion: Patients with central neuropathic pain syndromes managed in tertiary care centers were less likely to achieve a meaningful improvement in pain and function compared with patients with peripheral neuropathic pain at 12-month follow-up.
Increased mass losses from the Greenland ice sheet and inferred contributions to sea-level rise have heightened the need for hydrologic observations of meltwater exiting the ice sheet. We explore whether temporal variations in ice-sheet surface hydrology can be linked to the development of a downstream sediment plume in Kangerlussuaq Fjord by comparing: (1) plume area and suspended sediment concentration from Moderate Resolution Imaging Spectroradiometer (MODIS) imagery and field data; (2) ice-sheet melt extent from Special Sensor Microwave/Imager (SSM/I) passive microwave data; and (3) supraglacial lake drainage events from MODIS. Results confirm that the origin of the sediment plume is meltwater release from the ice sheet. Interannual variations in plume area reflect interannual variations in surface melting. Plumes appear almost immediately with seasonal surface-melt onset, provided the estuary is free of landfast sea ice. A seasonal hysteresis between melt extent and plume area suggests late-season exhaustion in sediment supply. Analysis of plume sensitivity to supraglacial events is less conclusive, with 69% of melt pulses and 38% of lake drainage events triggering an increase in plume area. We conclude that remote sensing of sediment plume behavior offers a novel tool for detecting the presence, timing and interannual variability of meltwater release from the ice sheet.
A pulse is a type of unstable glacier flow intermediate between normal flow and surging. Using Landsat MSS, TM and ETM+ imagery and feature-tracking software, a time series of mostly annual velocity maps from 1973 to 2012 was produced that reveals five pulses of Ruth Glacier, Alaska. Peaks in ice velocity were found in 1981, 1989, 1997, 2003 and 2010, approximately every 7 years. During these peak years the ice velocity increased 300%, from approximately 40 m a–1 to 160 m a–1. Based on the spatio-temporal behavior of Ruth Glacier during the pulse cycles, we suggest the pulses are due to enhanced basal motion via deformation of a subglacial till. The cyclical nature of the pulses is interpreted to be due to a thin till, with low permeability, that causes incomplete drainage of the till between the pulses, followed by eventual recharge and dilation of the till. These findings suggest care is needed when attempting to correlate changes in regional climate with decadal-scale changes in velocity, because in some instances basal conditions may have a greater influence on ice dynamics than climate.
Electroconvulsive therapy (ECT) is one of the most effective treatments for severe depression. However, little is known regarding brain functional processes mediating ECT effects.
In a non-randomized prospective study, functional magnetic resonance imaging data during the automatic processing of subliminally presented emotional faces were obtained twice, about 6 weeks apart, in patients with major depressive disorder (MDD) before and after treatment with ECT (ECT, n = 24). Additionally, a control sample of MDD patients treated solely with pharmacotherapy (MED, n = 23) and a healthy control sample (HC, n = 22) were obtained.
Before therapy, both patient groups equally showed elevated amygdala reactivity to sad faces compared with HC. After treatment, a decrease in amygdala activity to negative stimuli was discerned in both patient samples indicating a normalization of amygdala function, suggesting mechanisms potentially unspecific for ECT. Moreover, a decrease in amygdala activity to sad faces was associated with symptomatic improvements in the ECT sample (rspearman = −0.48, p = 0.044), and by tendency also for the MED sample (rspearman = −0.38, p = 0.098). However, we did not find any significant association between pre-treatment amygdala function to emotional stimuli and individual symptom improvement, neither for the ECT sample, nor for the MED sample.
In sum, the present study provides first results regarding functional changes in emotion processing due to ECT treatment using a longitudinal design, thus validating and extending our knowledge gained from previous treatment studies. A limitation was that ECT patients received concurrent medication treatment.
An X-band FM-CW radar was used to determine the feasibility of observing annual snow-accumulation layers in Antarctica with a high-resolution inexpensive radar system. The formation of layering boundaries, their resultant electromagnetic discontinuity and their detection by reflected energy are presented. Large returns from depths corresponding to reasonable positions for annual layers were found. The average accumulation rates calculated from the radar returns agree with those measured in a previous pit study done in the same area. The detection of the annual accumulation layers with this system implies a simple, inexpensive mobile radar could be used to profile large areas allowing the distorting effects of local topography to be removed.This type of system with a concurrent pit study could provide insight into the effect of sub-surface strata on spaceborne or airborne microwave remote sensing.
The evolution of four dynamic radar glacier zones at the surface of an alpine icefield in British Columbia is monitored using a time series of 35 First European Remote Sensing Satellite (ERS-1) synthetic aperture radar (SAR) images acquired from 1992 to 1994. These zones result from changing wetness and textural properties, and appear to represent: (1) cold snow with no liquid water present; (2) an initial melt front with an upper boundary near the elevation of the 0° isotherm; (3) metamorphosed, rapidly melting first-year snow with a rough or pitted surface; and (4) bare ice. This interpretation is aided by temperature and runoff data, air photographs and field measurements of snowpack properties acquired with two ERS-1 SAR scenes, ice-surface elevations derived from 1:50 000 topographic maps and simulations of radar backscatter from a geometric optics model of surface scattering. Meltwater production is affected by the development of zones (2), (3) and (4), which form, migrate up-elevation and disappear each year between April and September.
Background: Painful diabetic neuropathy (PDN) is a frequent complication of diabetes mellitus. Current treatment recommendations are based on short-term trials, generally of ≤3 months’ duration. Limited data are available on the long-term outcomes of this chronic disease. The objective of this study was to determine the long-term clinical effectiveness of the management of chronic PDN at tertiary pain centres. Methods: From a prospective observational cohort study of patients with chronic neuropathic non-cancer pain recruited from seven Canadian tertiary pain centres, 60 patients diagnosed with PDN were identified for analysis. Data were collected according to Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials guidelines including the Brief Pain Inventory. Results: At 12-month follow-up, 37.2% (95% confidence interval [CI], 23.0-53.3) of 43 patients with complete data achieved pain reduction of ≥30%, 51.2% (95% CI, 35.5-66.7) achieved functional improvement with a reduction of ≥1 on the Pain Interference Scale (0-10, Brief Pain Inventory) and 30.2% (95% CI, 17.2-46.1) had achieved both these measures. Symptom management included at least two medication classes in 55.3% and three medication classes in 25.5% (opioids, antidepressants, anticonvulsants). Conclusions: Almost one-third of patients being managed for PDN in a tertiary care setting achieve meaningful improvements in pain and function in the long term. Polypharmacy including analgesic antidepressants and anticonvulsants were the mainstays of effective symptom management.
A new maser receiver, operating between 20 and 24 GHz and constructed by the radiometer group at the CSIRO Division of Radiophysics, was first scheduled for astronomical observations in December 1981. In good observing conditions the system temperature was as low as 60 K. In conjunction with the versatility of the 1024-channel correlator and the large collecting area of the Parkes telescope (the central 37 m illuminated at 22 GHz yields a ratio of flux density to antenna temperature of 9∼ Jy K-1) the total system is a very powerful new tool. Here we report some observations of naturally occuring celestial H2O masers which we have studied with this system.
To assess the clinical effectiveness of a universal screening program compared with a risk factor–based program in reducing the rates of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) among admitted patients at the Ottawa Hospital.
Ottawa Hospital, a multicenter tertiary care facility with 3 main campuses, approximately 47,000 admissions per year, and 1,200 beds.
From January 1, 2006 through December 31, 2007 (24 months), admitted patients underwent risk factor–based MRSA screening. From January 1, 2008 through August 31, 2009 (20 months), all patients admitted underwent universal MRSA screening. To measure the effectiveness of this intervention, segmented regression modeling was used to examine monthly nosocomial MRSA incidence rates per 100,000 patient-days before and during the intervention period. To assess secular trends, nosocomial Clostridium difficile infection, mupirocin prescriptions, and regional MRSA rates were investigated as controls.
The nosocomial MRSA incidence rate was 46.79 cases per 100,000 patient-days, with no significant differences before and after intervention. The MRSA detection rate per 1,000 admissions increased from 9.8 during risk factor–based screening to 26.2 during universal screening. A total of 644 new nosocomial MRSA cases were observed in 1,448,488 patient-days, 323 during risk factor–based screening and 321 during universal screening. Secular trends in C. difficile infection rates and mupirocin prescriptions remained stable after the intervention whereas population-level MRSA rates decreased.
At Ottawa Hospital, the introduction of universal MRSA admission screening did not significantly affect the rates of nosocomial MRSA compared with risk factor–based screening.
The effects of surface treatment, particle size, and concentration of titanium dioxide (TiO2) and its dispersion on the photodegradation of two resin systems, epoxy and acrylic urethane, were examined. A suite of techniques, including laser scanning confocal microscopy (LSCM) and attenuated total reflectance -Fourier transform infrared spectroscopy (ATR-FTIR), was used to follow the degradation process of TiO2/polymer films as a function UV exposure. LSCM was used to show that both pigment dispersion and durability of the polymer matrix influenced the generation of pits/holes in pigmented polymer film. The type of pigment had a greater influence on the more durable polymer matrix, the acrylic urethane system. The epoxy system showed the greatest extent of degradation regardless of the TiO2 choice. The LCSM results were supported by the ATR-FTIR data.
Background. In a recent longitudinal study of first-episode schizophrenia patients, we found that while dysfunction of the right dorsolateral prefrontal cortex (DLPFC), right thalamus, left cerebellum and cingulate gyrus normalized with antipsychotic treatment and significant reduction in symptomatology, the left DLPFC, left thalamus, and right cerebellum remained disturbed. In the present study we investigated whether these abnormalities are also present in clinically stable, relatively well-functioning schizophrenia patients in comparison to control subjects during performance of the N-back working-memory task.
Method. Twelve schizophrenia and 12 control subjects completed the study. The functional images collected during scanning were analyzed using a random-effects model in a restricted set of six regions of interest (ROIs). In addition, the exploratory search in the entire brain volume was performed.
Results. The ROI analyses revealed relative underactivation in the region of the left DLPFC and the right cerebellum, as well as overactivation in the left cerebellum. The exploratory whole-brain search exposed additional overactivation in the medial frontal, anterior cingulate, and left parietal cortices.
Conclusions. The present study provides evidence of significant underactivations in stable schizophrenia patients in regions that we have previously observed to be dysfunctional in acutely psychotic and partially remitted patients, together with extensive overactivations in several regions that potentially reflect some compensatory mechanism or increased effort on the working-memory task.
Tarski  showed that for any set X, its set ω(X) of well-orderable subsets has cardinality strictly greater than that of X, even in the absence of the axiom of choice. We construct a Fraenkel-Mostowski model in which there is an infinite strictly descending sequence under the relation ∣ω(X)∣ = ∣Y∣. This contrasts with the corresponding situation for power sets, where use of Hartogs' ℵ-function easily establishes that there can be no infinite descending sequence under the relation .
Relatively small-scale laser-driven sources of short
wavelength radiation covering a range from the extreme
ultraviolet to the hard X-ray regime are now available.
Because the duration of the X-ray pulses is comparable
to, or shorter than the laser pulse width, it is possible
to carry out X-ray measurements with picosecond or femtosecond
Information on survival and cause of death in pre-senile dementia is scarce and the organisation of services controversial.
To study survival, place of death and death certification in pre-senile dementia.
Patients aged 45–64 were identified from hospital and community sources in the Northern health region (1985–89) and classified as having pre-senile dementia of Alzheimer type (PDAT) or pre-senile vascular dementia (PVD) by applying an algorithm to case notes. Deaths were ascertained from the National Health Service Central Registry (NHSCR) to 31 December 1998. Survival analysis was performed using the SPSS/PC program, and expected survival calculated from life tables.
Median survival time from diagnosis was 6.08 years and did not differ significantly in PDAT and PVD, or by age or gender; 19.3% of deaths occurred at home, 24.5% in nursing or residential homes and 56.3% in hospital; 72.4% of the death certificates mentioned dementia or Alzheimer's disease; 15.4% were still alive.
Pre-senile dementia has a variable but usually chronic course, requiring appropriate planning and services.
Intense continua of electromagnetic radiation of very
brief duration are formed in the interaction of focused
ultra-short terawatt laser pulses with matter. Two different
kinds of experiments, which have been performed utilizing
the Lund 10 Hz titanium-doped sapphire terawatt laser system
are being described, where visible radiation and X-rays,
respectively, have been generated. Focusing into water
leads to the generation of a light continuum through self-phase
modulation. The propagation of the light through tissue
was studied addressing questions related to optical mammography
and specific chromophore absorption. When terawatt laser
pulses are focused onto a solid target with high nuclear
charge Z, intense X-ray radiation of few ps duration
and with energies exceeding hundreds of keV is emitted.
Biomedical applications of this radiation are described,
including differential absorption and gated-viewing imaging.
The precise measurements of the spectral line profiles
near the short-wavelength limit of the Lyman series of
Al are reported. The spatially resolved narrow-band spectra
were attributed to macroscopic plasma parameters by using
the results of 1D and 2D hydrodynamic plasma modeling.
The gradual merging and broadening of the spectral lines
Al Lyε–θ was compared to the
synthetic spectra produced by atomic physics codes. The
discrepancies between the experimental and theoretical data
indicate the limits for applicability of standard theoretical