Effect of vascular burden as measured by vascular indexes upon vascular dementia: a matched case-control study

Paul Y Takahashi, Casey R Caldwell, Paul V TargonskiPrimary Care Internal Medicine, Mayo Clinic, Rochester MN, USABackground: Vascular dementia (VaD) is a challenging illness that affects the lives of older adults and caregivers. It is unclear how multiple vascular risk factor exposures (polyvascular disease) affect VaD.Purpose: To determine the relationship between multiple vascular risk exposures, as counted on an index in cases with VaD, compared with healthy age-/gender-matched controls.Methods: This was a matched case-control study of subjects living in Olmsted County, MN with documented VaD. Controls were selected by gender and age within 3 years from those who did not have dementia. The exposures included a total index (eleven exposure factors) added together, along with indexes for cerebrovascular disease (two exposures), cardiovascular disease (four exposures), vascular disease (three exposures), and lifestyle (two exposures). Analysis used matched conditional univariable logistic regression for each index.Results: A total of 1736 potential subjects were identified, and 205 subjects were diagnosed with VaD. There was a significant association of the total score index with an odds ratio of 1.45 (95% confidence interval 1.21–1.74). The cerebrovascular index was also associated with VaD with an odds ratio of 12.18 (95% confidence interval 6.29–23.61). The cardiovascular and vascular indexes were also associated with VaD status. The lifestyle index was not associated with VaD.Conclusion: The cumulative role of multiple vascular risk factors or diseases increased the risk of VaD, as noted by the total vascular index. The lifestyle index did not reveal any significant differences. Further work is required for evaluation of these indexes.Keywords: polyvascular disease, elderly, vascular dementi

Effect of alcohol and tobacco use on vascular dementia: a matched case control study

Paul Y Takahashi, Casey R Caldwell, Paul V TargonskiPrimary Care Internal Medicine, Mayo Clinic, Rochester, MN, USABackground: Vascular dementia is the second most common type of dementia in the United States. The underlying association of tobacco and alcohol with vascular dementia is not completely understood.Purpose: Determine the relationship of tobacco and alcohol use with the development of vascular dementia (VaD).Methods: This was a matched case-control study of subjects living in Olmsted County, MN. Cases of VaD were identified through medical record abstraction using conventionally accepted definitions of VaD, using the National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et l'Ensignement en Neurosicences (NINDS-AIRENS) criteria and were matched to controls by gender and age within 3 years among persons free of dementia on the index date. Exposure data for alcohol and tobacco use were abstracted by trained nurses, along with demographic, lifestyle, cerebrovascular, cardiovascular, and vascular comorbid disease characteristics. Matched conditional logistic regression for univariate and multivariate evaluation of the association of tobacco and alcohol use with VaD was utilized.Results: Current alcohol exposure was associated with a decreased risk of VaD with an odds ratio of 0.48 (95% confidence interval: 0.31–0.74). This protective effect of alcohol was seen in men, women, and subjects under 80 years of age. Tobacco use was not associated with VaD in univariate and multivariate analysis, and stratified analysis did not reveal any subgroup-specific associations between tobacco use and VaD in the study population.Conclusion: Current alcohol use appears to have protective effects against the development of vascular dementia. The effects are more pronounced in subjects under age 80. This may reflect the direct vascular effects of alcohol on the vascular system or may represent a surrogate for better social or functional status. Previous alcohol use was not protective. Tobacco use was not a risk factor for VaD status, which was possibly an indication of survivorship bias in the cohort.Keywords: vascular dementia, elderly, alcohol, tobacc

Two-color photoassociation spectroscopy of ytterbium atoms and the precise determinations of s-wave scattering lengths

By performing high-resolution two-color photoassociation spectroscopy, we have successfully determined the binding energies of several of the last bound states of the homonuclear dimers of six different isotopes of ytterbium. These spectroscopic data are in excellent agreement with theoretical calculations based on a simple model potential, which very precisely predicts the s-wave scattering lengths of all 28 pairs of the seven stable isotopes. The s-wave scattering lengths for collision of two atoms of the same isotopic species are 13.33(18) nm for ^{168}Yb, 3.38(11) nm for ^{170}Yb, -0.15(19) nm for ^{171}Yb, -31.7(3.4) nm for ^{172}Yb, 10.55(11) nm for ^{173}Yb, 5.55(8) nm for ^{174}Yb, and -1.28(23) nm for ^{176}Yb. The coefficient of the lead term of the long-range van der Waals potential of the Yb_2 molecule is C_6=1932(30) atomic units $(E_h a_0^6 \approx 9.573\times 10^{-26}$ J nm^6).Comment: 9 pages, 7 figure

Association between vitamin D and pressure ulcers in older ambulatory adults: results of a matched case–control study

Usha R Kalava1, Stephen S Cha2, Paul Y Takahashi1,31Department of Internal Medicine, Division of Primary Care Internal Medicine, 2Department of Biostatistics, 3Kogod Center of Aging, Mayo Clinic, Rochester, MN, USABackground: Pressure ulcers are common among older adults, but knowledge about nutritional risk factors is still developing. Vitamin D deficiency is common in the elderly population and is required for normal skin proliferation. The role of vitamin D in pressure ulceration and wound healing is not known. The purpose of this case–control study was to determine the association between vitamin D levels and pressure ulceration in an older community-dwelling cohort.Methods: All cases and controls were community-dwelling elderly older than 60 years in a primary care panel in Olmsted County, MN. Pressure ulcer cases were defined clinically. The controls were age-matched and gender-matched to controls without pressure ulceration. The main exposure variable was 25-hydroxyvitamin D levels in both groups. The other exposure variable was the Charlson Comorbidity Index used to measure medical comorbidity. The analysis included univariate and conditional logistic regression for 25-hydroxyvitamin D levels.Results: The average (standard deviation) age of the study participants with a pressure ulcer was 80.46 years (±8.67), and the average vitamin D level was 30.92 ng/mL (±12.46). In univariate analysis, Vitamin D deficiency (levels < 25 ng/mL) was associated with pressure ulcers (odds ratio: 1.871, P = 0.0154). Comorbidities of the subjects calculated using the Charlson Comorbidity Index were also associated with pressure ulcers (odds ratio: 1.136, P < 0.001). In the final conditional logistical regression model, the association of Vitamin D and pressure ulcers became nonsignificant after adjustment for comorbid illness.Conclusion: Medical comorbidities increased the risk of pressure ulceration. Vitamin D deficiency was not an independent risk factor for pressure ulceration, and may be a marker of comorbid illness.Keywords: pressure ulcer, vitamin D, case–control study, aging, geriatric

A standardisation proof for algebraic pattern calculi

This work gives some insights and results on standardisation for call-by-name pattern calculi. More precisely, we define standard reductions for a pattern calculus with constructor-based data terms and patterns. This notion is based on reduction steps that are needed to match an argument with respect to a given pattern. We prove the Standardisation Theorem by using the technique developed by Takahashi and Crary for lambda-calculus. The proof is based on the fact that any development can be specified as a sequence of head steps followed by internal reductions, i.e. reductions in which no head steps are involved.Comment: In Proceedings HOR 2010, arXiv:1102.346

Reduced LRRK2 in association with retromer dysfunction in post-mortem brain tissue from LRRK2 mutation carriers

Missense mutations in leucine-rich repeat kinase 2 (LRRK2) are pathogenic for familial Parkinson's disease. However, it is unknown whether levels of LRRK2 protein in the brain are altered in patients with LRRK2-associated Parkinson's disease. Because LRRK2 mutations are relatively rare, accounting for approximately 1% of all Parkinson's disease, we accessioned cases from five international brain banks to investigate levels of the LRRK2 protein, and other genetically associated Parkinson's disease proteins. Brain tissue was obtained from 17 LRRK2 mutation carriers (12 with the G2019S mutation and five with the I2020T mutation) and assayed by immunoblot. Compared to matched controls and idiopathic Parkinson's disease cases, we found levels of LRRK2 protein were reduced in the LRRK2 mutation cases. We also measured a decrease in two other proteins genetically implicated in Parkinson's disease, the core retromer component, vacuolar protein sorting associated protein 35 (VPS35), and the lysosomal hydrolase, glucocerebrosidase (GBA). Moreover, the classical retromer cargo protein, cation-independent mannose-6-phosphate receptor (MPR300, encoded by IGF2R), was also reduced in the LRRK2 mutation cohort and protein levels of the receptor were correlated to levels of LRRK2. These results provide new data on LRRK2 protein expression in brain tissue from LRRK2 mutation carriers and support a relationship between LRRK2 and retromer dysfunction in LRRK2-associated Parkinson's disease brain

Radio-Frequency Measurements of Coherent Transition and Cherenkov Radiation: Implications for High-Energy Neutrino Detection

We report on measurements of 11-18 cm wavelength radio emission from interactions of 15.2 MeV pulsed electron bunches at the Argonne Wakefield Accelerator. The electrons were observed both in a configuration where they produced primarily transition radiation from an aluminum foil, and in a configuration designed for the electrons to produce Cherenkov radiation in a silica sand target. Our aim was to emulate the large electron excess expected to develop during an electromagnetic cascade initiated by an ultra high-energy particle. Such charge asymmetries are predicted to produce strong coherent radio pulses, which are the basis for several experiments to detect high-energy neutrinos from the showers they induce in Antarctic ice and in the lunar regolith. We detected coherent emission which we attribute both to transition and possibly Cherenkov radiation at different levels depending on the experimental conditions. We discuss implications for experiments relying on radio emission for detection of electromagnetic cascades produced by ultra high-energy neutrinos.Comment: updated figure 10; fixed typo in equation 2.2; accepted by PR

Lattice fermion models with supersymmetry

We investigate a family of lattice models with manifest N=2 supersymmetry. The models describe fermions on a 1D lattice, subject to the constraint that no more than k consecutive lattice sites may be occupied. We discuss the special properties arising from the supersymmetry, and present Bethe ansatz solutions of the simplest models. We display the connections of the k=1 model with the spin-1/2 antiferromagnetic XXZ chain at \Delta=-1/2, and the k=2 model with both the su(2|1)-symmetric tJ model in the ferromagnetic regime and the integrable spin-1 XXZ chain at \Delta=-1/\sqrt{2}. We argue that these models include critical points described by the superconformal minimal models.Comment: 28 pages. v2: added new result on mapping to XXZ chai