70 research outputs found
Multistate APLIP and VibLIP: from molecular bond extension to atomic transport
APLIP is a method for using a STIRAP-like three-state configuration with two laser pulses for continuous extension of a molecular bond, introduced in 1998. It is based on time-dependent light-induced potential surfaces (LIP). In VibLIP one extends the idea into a method for tailoring the vibrational state while changing the electronic state, introduced in 2000. Here I discuss the extension of both methods to situations that involve more than three electronic states, and note the possibility of using the method on adiabatic transport of atoms between microtraps or equivalent structures.</p
Superparabolic level-glancing models for two-state quantum systems
Level crossing models for two-state quantum systems are applicable to a wide variety of physical problems. We address the special case of level glancing, i.e., when energy levels reach a degeneracy at a specific point of time, but never actually cross. The simplest model with such behavior is the parabolic model, and its generalizations, which we call superparabolic models. We discuss their basic characteristics, complementing the previous work on the related nonlinear crossing models [Vitanov and Suominen, Phys. Rev. A 59, 4580 (1999)]
Exact soliton-like solutions of the radial Gross-Pitaevskii equation
We construct exact ring soliton-like solutions of the cylindrically symmetric (i.e. radial) Gross-Pitaevskii equation with a potential, using the similarity transformation method. Depending on the choice of the allowed free functions, the solutions can take the form of stationary dark or bright rings whose time dependence is in the phase dynamics only, or oscillating and bouncing solutions, related to the second Painleve transcendent. In each case the potential can be chosen to be time independent.</p
Guiding and Trapping of Electron Spin Waves in Atomic Hydrogen Gas
We present a high magnetic field study of electron spin waves in atomic hydrogen gas compressed to high densities of similar to 10(18) cm(-3) at temperatures ranging from 0.26 to 0.6 K. We observed a variety of spin wave modes caused by the identical spin rotation effect with strong dependence on the spatial profile of the polarizing magnetic field. We demonstrate confinement of these modes in regions of strong magnetic field and manipulate their spatial distribution by changing the position of the field maximum
Identical spin rotation effect and electron spin waves in quantum gas of atomic hydrogen
We present an experimental study of electron spin waves in atomic hydrogen gas compressed to high densities of similar to 5 x 10(18) cm(-3) at temperatures ranging from 0.26 to 0.6 K in the strong magnet ic field of 4.6 T. Hydrogen gas is in a quantum regime when the thermal de-Broglie wavelength is much larger than the s-wave scattering length. In this regime the identical particle effects play a major role in atomic collisions and lead to the identical spin rotation effect (ISR). We observed a variety of spin wave modes caused by this effect with strong dependence on the magnetic potential caused by variations of the polarizing magnetic field. We demonstrate confinement of the ISR modes in the magnetic potential and manipulate their properties by changing the spatial profile of the magnetic field. We have found that at a high enough density of H gas the magnons accumulate in their ground state in the magnetic trap and exhibit long coherence, which has a profound effect on the electron spin resonance spectra. Such macroscopic accumulation of the ground state occurs at a certain critical density of hydrogen gas, where the chemical potential of the magnons becomes equal to the energy of their ground state in the trapping potential
Study circles improve the precision in nutritional care in special accommodations
Background: Disease-related malnutrition is a major health problem in the elderly population, but it has until recently received very little attention, especially are management issues under-explored. By identifying residents at the risk of undernutrition, appropriate nutritional care can be provided. Objectives: Do study circles and policy documents improve the precision in nutritional care and decrease the prevalence of low or high BMI? Design: Pre and post intervention study. Setting: Special accommodations (nursing homes) within six municipalities were involved. Participants: In 2005, 1726 (90.4%) out of 1910 residents agreed to participate and in 2007, 1526 (81.8%) out of 1866 residents participated. Intervention: Study circles in one municipality, having a policy document in one municipality and no intervention in four municipalities. Measurements: Risk of undernutrition was defined as involving any of: involuntary weight loss, low BMI, and/or eating difficulties. Overweight was defined as high BMI. Results: In 2005 and 2007, 64% of 1726 and 66% of 1526 residents respectively were at the risk of undernutrition. In 2007 significantly more patients in the study circle municipality were accurately provided protein and energy enriched food compared to in the no intervention municipalities. There was a decrease in the prevalence of low BMI in the study circle municipality and the prevalence of overweight increased in the policy document municipality between 2005 and 2007
Cognitive stimulation in the workplace, plasma proteins, and risk of dementia: three analyses of population cohort studies
Objectives: To examine the association between cognitively stimulating work and subsequent risk of dementia and to identify protein pathways for this association. /
Design: Multicohort study with three sets of analyses. /
Setting: United Kingdom, Europe, and the United States. /
Participants: Three associations were examined: cognitive stimulation and dementia risk in 107 896 participants from seven population based prospective cohort studies from the IPD-Work consortium (individual participant data meta-analysis in working populations); cognitive stimulation and proteins in a random sample of 2261 participants from one cohort study; and proteins and dementia risk in 13 656 participants from two cohort studies. /
Main outcome measures: Cognitive stimulation was measured at baseline using standard questionnaire instruments on active versus passive jobs and at baseline and over time using a job exposure matrix indicator. 4953 proteins in plasma samples were scanned. Follow-up of incident dementia varied between 13.7 to 30.1 years depending on the cohort. People with dementia were identified through linked electronic health records and repeated clinical examinations. /
Results: During 1.8 million person years at risk, 1143 people with dementia were recorded. The risk of dementia was found to be lower for participants with high compared with low cognitive stimulation at work (crude incidence of dementia per 10 000 person years 4.8 in the high stimulation group and 7.3 in the low stimulation group, age and sex adjusted hazard ratio 0.77, 95% confidence interval 0.65 to 0.92, heterogeneity in cohort specific estimates I2=0%, P=0.99). This association was robust to additional adjustment for education, risk factors for dementia in adulthood (smoking, heavy alcohol consumption, physical inactivity, job strain, obesity, hypertension, and prevalent diabetes at baseline), and cardiometabolic diseases (diabetes, coronary heart disease, stroke) before dementia diagnosis (fully adjusted hazard ratio 0.82, 95% confidence interval 0.68 to 0.98). The risk of dementia was also observed during the first 10 years of follow-up (hazard ratio 0.60, 95% confidence interval 0.37 to 0.95) and from year 10 onwards (0.79, 0.66 to 0.95) and replicated using a repeated job exposure matrix indicator of cognitive stimulation (hazard ratio per 1 standard deviation increase 0.77, 95% confidence interval 0.69 to 0.86). In analysis controlling for multiple testing, higher cognitive stimulation at work was associated with lower levels of proteins that inhibit central nervous system axonogenesis and synaptogenesis: slit homologue 2 (SLIT2, fully adjusted β −0.34, P<0.001), carbohydrate sulfotransferase 12 (CHSTC, fully adjusted β −0.33, P<0.001), and peptidyl-glycine α-amidating monooxygenase (AMD, fully adjusted β −0.32, P<0.001). These proteins were associated with increased dementia risk, with the fully adjusted hazard ratio per 1 SD being 1.16 (95% confidence interval 1.05 to 1.28) for SLIT2, 1.13 (1.00 to 1.27) for CHSTC, and 1.04 (0.97 to 1.13) for AMD. /
Conclusions: The risk of dementia in old age was found to be lower in people with cognitively stimulating jobs than in those with non-stimulating jobs. The findings that cognitive stimulation is associated with lower levels of plasma proteins that potentially inhibit axonogenesis and synaptogenesis and increase the risk of dementia might provide clues to underlying biological mechanisms
Gender differences in health care use among the elderly population in areas of Norway and Finland. A cross-sectional analysis based on the HUNT study and the FINRISK Senior Survey
BACKGROUND: The aim of the study was to examine gender differences in the self-reported use of health care services by the elderly in rural and metropolitan areas of two Nordic countries with slightly different health care systems: Finland and Norway. METHODS: Population based, cross-sectional surveys conducted in Nord-Tröndelag Norway (1995–97) and in rural and metropolitan areas of Finland (1997) were employed. In the Norwegian data, a total of 7,919 individuals, aged 65–74 years old were included, and the Finnish data included 1,500 individuals. The outcome variables comprised whether participants had visited a general practitioner or a specialist, or had received hospital care or physiotherapy during the past 12 months. Gender differences in the use of health care services were analysed by multiple logistic regression, controlling for health status and socio-demographic characteristics. RESULTS: In Norway, elderly women visited a specialist or were hospitalised less often than men. In Finland, elderly women used all health care services except hospital care more often than men. In Norway, less frequent use of specialist care by women was not associated with self-reported health or chronic diseases. CONCLUSION: The findings revealed differences in self-reported use of secondary care among different genders in areas of Norway and Finland
Measurements of daily energy intake and total energy expenditure in people with dementia in care homes: the use of wearable technology.
Objectives: To estimate daily total energy expenditure (TEE) using a physical activity monitor, combined
with dietary assessment of energy intake to assess the relationship between daily energy expenditure and
patterns of activity with energy intake in people with dementia living in care homes. Design and setting:
A cross-sectional study in care homes in the UK. Participants: Twenty residents with confirmed dementia
diagnosis were recruited from two care homes that specialised in dementia care. Measurements: A
physical activity monitor (Sensewear TM Armband , Body Media, Pittsburgh, PA) was employed to
objectively determine total energy expenditure, sleep duration and physical activity. The armband was
placed around the left upper triceps for up to 7 days. Energy intake was determined by weighing all food
and drink items over 4 days (3 weekdays and 1 weekend day) including measurements of food wastage.
Results: The mean age was 78.7 (SD ± 11.8) years, Body Mass Index (BMI) 23.0 (SD ± 4.2) kg/m2
; 50%
were women. Energy intake (mean 7.4; SD ± 2.6) MJ/d) was correlated with TEE (mean 7.6; SD ± 1.8 MJ/d;
r=0.49, p<0.05). Duration of sleeping ranged from 0.4-12.5 (mean 6.1) hrs/d and time spent lying down
was 1.3-16.0 (8.3) hrs/d. On average residents spent 17.9 (6.3-23.4) hrs/d undertaking sedentary activity.
TEE was correlated with BMI (r=0.52, p<0.05) and body weight (r=0.81, p<0.001) but inversely related to
sleep duration (r=-0.59, p<0.01) and time lying down (r=-0.62, p<0.01). Multiple linear regression analysis
revealed that after taking BMI, sleep duration and time spent lying down into account, TEE was no longer
correlated with energy intake. Conclusions: The results show the extent to which body mass, variable
activity and sleep patterns may be contributing to TEE and together with reduced energy intake, energy
requirements were not satisfied. Thus wearable technology has the potential to offer real-time
monitoring to provide appropriate nutrition management that is more person-centred to prevent weight
loss in dementi
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