Natural background radiation in the proposed Illinois SSC siting area

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White matter microstructure associations with episodic memory in adults with Down syndrome: a tract-based spatial statistics study.

BACKGROUND: Nearly all persons with Down syndrome will show pathology of Alzheimer's disease in their 40s. There is a critical need for studies to identify early biomarkers of these various pathological changes of Alzheimer's disease in the Down syndrome population and understand the relationship of these biomarkers to cognitive symptoms in order to inform clinical trials. Although Alzheimer's disease is often considered a disease of gray matter, white matter degeneration has been documented during the preclinical stage of Alzheimer's disease. The current study examined the association between diffusion tensor imaging (DTI) measures of white matter microstructure and episodic memory performance in 52 adults with Down syndrome. METHODS: Seventy (N = 70) participants (M = 40.13, SD = 7.77 years) received baseline scans as part of the Neurodegeneration in Aging Down Syndrome (NiAD) study at two imaging facilities (36 at the University of Wisconsin-Madison [UW-Madison] and 34 at the University of Pittsburgh Medical Center [UPMC]). All participants had genetically confirmed trisomy 21. Fifty-two (N = 52) participants remained after QC. The DTI measures, fractional anisotropy (FA) and mean diffusivity (MD), were calculated for each participant. A combined measure of episodic memory was generated by summing the z-scores of (1) Free and Cued Recall test and (2) Rivermead Behavioural Memory Test for Children Picture Recognition. The DTI data were projected onto a population-derived FA skeleton and tract-based spatial statistics analysis was conducted using the FSL tool PALM to calculate Pearson's r values between FA and MD with episodic memory. RESULTS: A positive correlation of episodic memory with FA and a negative correlation of episodic memory and MD in the major association white matter tracts were observed. Results were significant (p < 0.05) after correction for chronological age, imaging site, and premorbid cognitive ability. CONCLUSION: These findings suggest that white matter degeneration may be implicated in early episodic memory declines prior to the onset of dementia in adults with Down syndrome. Further, our findings suggest a coupling of episodic memory and white matter microstructure independent of chronological age

White matter microstructure associations to amyloid burden in adults with Down syndrome.

INTRODUCTION: Individuals with Down syndrome (DS) are at an increased risk of developing Alzheimer's Disease (AD). One of the early underlying mechanisms in AD pathology is the accumulation of amyloid protein plaques, which are deposited in extracellular gray matter and signify the first stage in the cascade of neurodegenerative events. AD-related neurodegeneration is also evidenced as microstructural changes in white matter. In this work, we explored the correlation of white matter microstructure with amyloid load to assess amyloid-related neurodegeneration in a cohort of adults with DS. METHODS: In this study of 96 adults with DS, the relation of white matter microstructure using diffusion tensor imaging (DTI) and amyloid plaque burden using [11C]PiB PET were examined. The amyloid load (AβL) derived from [11C]PiB was used as a global measure of amyloid burden. AβL and DTI measures were compared using tract-based spatial statistics (TBSS) and corrected for imaging site and chronological age. RESULTS: TBSS of the DTI maps showed widespread age-by-amyloid interaction with both fractional anisotropy (FA) and mean diffusivity (MD). Further, diffuse negative association of FA and positive association of MD with amyloid were observed. DISCUSSION: These findings are consistent with the white matter microstructural changes associated with AD disease progression in late onset AD in non-DS populations

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Geophysical study of Cenozoic rocks from the McMurdo Sound region, Antarctica

Bibliography: pages [53]-57.Magnetic profiles across three volcanic cones are modeled. These are located in Taylor Valley near Sollas Glacier, near the mouth of Wright valley, and in Wright Valley near Meserve Glacier. The Sollas Glacier profile shows a polarity reversal, with a negative anomaly of about 1400 gammas. The profile near Meserve Glacier has both normal and reverse polarizations. The Meserve model also suggests the location of feeders of both events. Polarization direction is determined for four oriented samples of the McMurdo volcanics. One sample from the Meserve site shows a probable reversal, and two samples from Taylor Valley area show normal orientation. The fourth sample, taken from the Meserve site, gives inconclusive results. Magnetic susceptibility, density and compressional wave velocities are determined for 47 hand samples from the McMurdo Sound region. The samples consist of McMurdo Volcanics, of Cenozoic sediments, and of lower crustal xenoliths found in the volcanics. For 38 more samples of the McMurdo Volcanics, only the magnetic susceptibility is measured. The volcanic samples were all taken from the vicinity of Wright and Taylor Valleys. The densities of the volcanic samples range from 1.86 to 3.02 g/cc, the velocity values range from 1940 to 4840 m/sec, and the susceptibility values range from .0002 to .008 c.g.s. units. The Cenozoic sediment samples were taken from the mouth of Taylor Valley, from the Strand Moraine, from Mt. Discovery, and from Brown Peninsula, where they occur as glacial erratics. The densities range from 1.98 to 2.79 g/cc. The velocities vary from 1024 to 4866 m/sec and the susceptibilities vary from .000008 to .0025 in c.g.s. units. The xenoliths were obtained from volcanic cones found on Ross Island and in the Dry Valleys region. The densities of the xenoliths range from 2.52 to 3.05 g/cm. The velocities for the xenoliths are very low, probably due to the presence of microfractures. The susceptibilities range from .00003 to .00018 c.g.s. units.M.S. (Master of Science