3,834 research outputs found
Yukawa force spectroscopy to search for violations of Newtonâs law of gravity below 1 ÎŒm distances
Gravity is well tested on several length scales, but some unified theories predict
deviations in the region below 1 mm. In this thesis I will present a method
to search for such deviations in the sub-micrometre length scale. Below 1 ÎŒm,
the electrostatic and the Casimir force are stronger than the gravitational
force by some magnitudes. To distinguish these forces, I have designed a new
force measurement setup based on the frequency modulation AFM technique.
Utilizing a quartz based parallelogram cantilever, it is feasible to measure
these forces with sufficient accuracy for us to set new constraints for possible
deviations of gravity. In this thesis I will present a new method of measuring
such deviations of gravity, and show the initial results I have obtained using it.
This will show that the measurement concept works, but that improvements
are necessary before we can achieve optimum measurement uncertainty
Genetics of subcortical vascular dementia
AbstractSubcortical vascular dementia or cerebral small vessel disease is a common cause of disability in the elderly. On magnetic resonance imaging the disease is manifested as white matter lesions, lacunes and microbleeds. Its etiology is complex, with age and hypertension as established risk factors. The heritability of white matter lesions is constantly high over different populations. Linkage studies identified several loci for these lesions however no genes responsible for the linkage signals had been identified so far. Results from genetic association studies using the candidate gene approach support the role of APOE, the reninâangiotensin system, as well as the Notch3 signaling pathway in the development of subcortical vascular dementia. The recent genomegenome wide association study on white matter lesions identified a novel locus on chromosome 17q25 harboring several genes such as TRIM65 and TRIM47 which pinpoints to possible novel mechanisms leading to these lesions
The Optimal H\"older Exponent in Massari's Regularity Theorem
We determine the optimal H\"older exponent in Massari's regularity theorem
for sets with variational mean curvature in . In fact, we obtain
regularity with improved exponents and at the same time provide sharp
counterexamples
Multi-stage Biomarker Models for Progression Estimation in Alzheimerâs Disease
The estimation of disease progression in Alzheimerâs disease
(AD) based on a vector of quantitative biomarkers is of high interest
to clinicians, patients, and biomedical researchers alike. In this work,
quantile regression is employed to learn statistical models describing the
evolution of such biomarkers. Two separate models are constructed using
(1) subjects that progress from a cognitively normal (CN) stage to mild
cognitive impairment (MCI) and (2) subjects that progress from MCI
to AD during the observation window of a longitudinal study. These
models are then automatically combined to develop a multi-stage disease
progression model for the whole disease course. A probabilistic approach
is derived to estimate the current disease progress (DP) and the disease
progression rate (DPR) of a given individual by fitting any acquired
biomarkers to these models. A particular strength of this method is that
it is applicable even if individual biomarker measurements are missing
for the subject. Employing cognitive scores and image-based biomarkers,
the presented method is used to estimate DP and DPR for subjects from
the Alzheimerâs Disease Neuroimaging Initiative (ADNI). Further, the
potential use of these values as features for different classification tasks
is demonstrated. For example, accuracy of 64% is reached for CN vs.
MCI vs. AD classification
Investigation of Proliferative Kidney Disease in Brown Trout and Habitat Characteristics Associated with a Swiss Wastewater Treatment Plant
Wastewater treatment plants (WWTP) play a critical role in mitigating adverse environmental
impacts of urban and industrial wastewater by removing pollutants and reducing the risk
of contamination. Discharges of treated effluents from WWTPs can still have significant effects on
freshwater ecosystems, particularly on sensitive species like brown trout. We analyzed the effects
of a modern WWTP on a freshwater ecosystem, studying fish biodiversity and biomass, the occurrence
of the parasitic disease Proliferative Kidney Disease (PKD) on brown trout, river water
temperatures throughout the year and fish habitat and diversity. No major differences between upand
downstream of the WWTP were observed in habitat structure and attractiveness, fish biomass
and species diversity, nor in PKD prevalence or intermediate host presence. However, immediately
at the WWTPâs effluent and continuing downstream, the water temperature rose by almost 1 °C.
While WWTPs are crucial for reducing the environmental impact of urban and industrial wastewater,
their effluents can still have important consequences for freshwater ecosystems. Brown trout are
particularly susceptible to increases in water temperature, especially regarding PKD severity and
consequent mortality. To ensure the long-term health and sustainability of freshwater ecosystems, it
is imperative to improve measures to minimize water temperature rises and mitigate downstream
cascade effects on sensitive organisms like brown trout
Excitonâpolaritons in a ZnO-based microcavity: polarization dependence and nonlinear occupation
We report on the occupation of the lower excitonâpolariton branch
in a ZnO-based microcavity as a function of the detuning between the exciton
and the uncoupled cavity-photon mode and on the optical excitation density.
We emphasize the difference in the dispersion and occupation of the lower
polariton branch as a function of the linear polarization of the emitted light.
For the negative detuning regime, we found an energy splitting between the
transverse electric (TE)- and transverse magnetic (TM)-polarized states at inplane
wave vectors between 0.4Ă107 mâ1 and 1.2Ă107 mâ1, which is caused
by the polarization dependence of the dispersion of the uncoupled cavity-photon
mode. The maximum energy splitting of about 6 meV was observed for a
detuning of about 1 = â70 meV. From the integrated photoluminescence peak,
we deduce the occupation of the lower polariton branch as well as the scattering
rates of excitonâpolaritons into the lower polariton branch. We found that the
energy splitting causes an enhanced scattering of excitonâpolaritons into
the lower polariton branch for the TM-polarized light compared with that of the
TE-polarized light. By varying the excitation density, we observe a superlinear
growth of the lower polariton branch occupation for negative and intermediate
detuning regimes. For an accumulation of excitonâpolaritons in the ground state
at low temperatures (T = 10 K), we found an intermediate detuning regime
(â20 meV < 1 < +20 meV) as the optimum. With increasing temperature, this
optimum detuning range shifts to larger negative values
Overview of the incorporation of legumes into new food options : an approach on versatility, nutritional, technological, and sensory quality
Consumers are more aware and demanding of healthy food options, besides being concerned with environment-friendly consumption. This paper aims to evaluate nutritional, technological, and sensory characteristics of legumes and their productsâ quality and versatility, considering potential applications in new food options. Legumes are foods that have a recognized nutritional group since they have high protein and fiber content. However, their consumption is still somehow limited for some reasons: in some countries it is not easy to find all the species or cultivars, they need an organization and planning before preparation since they need soaking, and there is the presence of antinutritional factors. Due to the different functionalities of legume proteins, they can be applied to a variety of foods and for different purposes, as grains themselves, aquafaba, extracts, flours, brans, and textured proteins and sprouts. These products have been inserted as ingredients in infant food formulations, gluten-free foods, vegetarian diets, and in hybrid products to reduce food costs as well. Foods such as bread, cakes, cookies, meat analogues, and other baked or cooked products have been elaborated with nutritional, technological and sensory quality. Further development of formulations focused on improving the quality of legume-based products is necessary because of their potential and protein quality
PHYSICOCHEMICAL PROFILE AND SENSORY EVALUATION OF CAKES WITH FLAXSEED AND YACON FLOUR ASSOCIATED TO SWEETENERS
The objective of this study was to evaluate the chemical, physical and sensory characteristics of cakes made with yacon and flaxseed flour as an alternative for patients with Diabetes. Four cakes were prepared: standard cake (CS) â yacon flour, flaxseed flour and sugar; cake A (CA) â yacon flour and flaxseed flour; cake B (CB) â yacon flour, flaxseed flour and sucralose and acesulfame-k; cake C (CC) â yacon flour, flaxseed flour and stevia. Moisture, carbohydrates, proteins, lipids, dietary fiber, ash and energy value of the products were evaluated. For the physical analysis were determined before and after cooking weight and height, and thermal factor. For sensory analysis, 40 untrained people evaluated appearance, color, texture, flavor, overall acceptability and purchase intention. All the cakes had great fibers intake. The cake with more calories and carbohydrate content was CS. This cake also had a higher weight before and after cooking. In sensory evaluation, the cakes did not showed significant differences in appearance and color. In flavor attributes, overall acceptance and in intention to purchase, CS and CB were better accepted. Thus, it can be concluded that the cake with yacon and flaxseed associated to sucralose and acesulfame-k is a good alternative for patients with Diabetes mellitus due to functional properties and good fiber content
Angiotensinogen gene promoter haplotype and microangiopathy-related cerebral damage: results of the Austrian Stroke Prevention Study
BACKGROUND AND PURPOSE: Microangiopathy-related cerebral damage (MARCD) is a common finding in the elderly. It may lead to cognitive impairment and gait disturbances. Arterial hypertension and age are the most important risk factors. We assessed the association between MARCD and sequence alterations in the promoter region of the angiotensinogen (AGT) gene. METHODS: We studied 410 randomly selected community-dwelling individuals aged 50 to 75 years. MARCD was defined as early confluent or confluent white matter hyperintensities or lacunes on a 1.5-T MRI. The AGT promoter was analyzed by temporal temperature gradient gel electrophoresis and automated sequencing. RESULTS: We detected 4 polymorphic sites, at positions -6, -20, -153, and -218. They created 5 haplotypes, which we coded as A (-6:g, -20:a, -153:g, -218g), B (-6:a, -20:c, -153:g, -218:g), C (-6:a, -20:c, -153:a, -218:g), D (-6:a, -20:a, -153:g, -218:g), and E (-6:a, -20:a, -153:g, -218:a). MARCD was seen in 7 subjects (63.6%) carrying 2 copies of the B haplotype (B/B), in 12 subjects (38.7%) carrying 1 copy of the B haplotype in the absence of the A haplotype (B+/A-), but in only 70 subjects (19.0%) in the remaining cohort (P:<0.001). The odds ratios for the B/B and the B+/A- genotypes were 8.0 (95% CI, 2.1 to 31.1; P:=0.003) and 1.8 (95% CI, 0.8 to 4.2; P:=0.14) after adjustment for possible confounders. CONCLUSIONS: The B haplotype of the AGT promoter in the absence of the wild-type A haplotype might represent a genetic susceptibility factor for MARCD
Genetic Determinants of Cerebral Small Vessel Disease
The study demonstrates the firstevidence of a significant association between the T/T148 genotype at the .-fibrinogen gene and carotid atherosclerosis.
The results should be interpreted with caution, given the small number of T/T homozygotes. A larger cohort will ultimately be required to confirm whether or not this association is real
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