146,684 research outputs found
The impact of time and repeated exposure on famous person knowledge in amnestic Mild cognitive impairment and Alzheimer’s disease
Objective: Famous people knowledge has been shown to be impaired early in Alzheimer’s disease (AD) and amnestic mild cognitive impairment (aMCI). However, the question of whether recently acquired knowledge is more impaired than remotely acquired knowledge remains a matter of debate. The aim of this study was to investigate the patterns of semantic memory impairment in aMCI and AD by investigating two factors that may influence the retrieval of such knowledge, namely remoteness and frequency of repetition of information over time. Method: Three groups (19 controls, 20 aMCI and 20 AD patients) were compared on a test assessing general and specific biographical knowledge about famous people, where the period of acquired fame (remote vs recent) and the type of fame (enduring vs transient) were controlled for. Results: Global performance of aMCI and AD patients was significantly poorer than that of controls. However, different patterns of recall were observed as a function of time and type of fame. A temporal gradient was found in both patient groups for enduring names but not for transient ones, whereby knowledge about remote enduring famous persons was better recalled. Patients were more impaired at questions assessing specific biographical knowledge (unique to an individual) than more general knowledge. Conclusions: Tests of famous people knowledge offer a unique opportunity to investigate semantic deficits in aMCI and AD, because they make it possible to estimate the time at which memories were acquired, as well as the type of fame. Results are discussed in light of memory consolidation models.
Keywords
Effects of a falls exercise intervention on strength, power, functional ability and bone in older frequent fallers: FaME (Falls Management Exercise) RCT secondary analysis
OBJECTIVES: Falls Management Exercise (FaME) has been shown to reduce falls in frequent fallers and in lower risk sedentary older people. The effects of FaME on the strength, power, physical function and bone health of frequently falling older women are yet to be established. METHODS: This paper reports secondary analysis of data from the original randomised controlled trial of FaME in 100 community dwelling women aged ≥65 years with a history of ≥3 falls in the previous year. Intervention was group delivered, weekly one hour tailored dynamic balance and strength exercise classes and home exercise for nine months. OUTCOME MEASURES INCLUDED: strength (handgrip, quadriceps, hamstrings, hip abductors, ankles), lower limb explosive power and functional tests (timed up and go, functional reach, timed floor rise and balance), analysed using Linear Mixed Model analysis. Bone Mineral Density (BMD) at hip and spine was measured in a smaller sub-group and analysed using t-tests. RESULTS: Significant time*group interactions in all measures of strength, except isometric ankle dorsiflexion, concentric hamstring and eccentric quadriceps strength. These improvements in strength equated to average improvements of 7-45%. There were also significant improvements in explosive power (W/kg) (18%, p=0.000), timed up and go (16%, p=0.000), functional reach (17%, p=0.000), floor rise (10%, p=0.002) and eyes closed static balance (56%, p=0.000). There was a significant loss of hip BMD in the control group (neck of femur p<0.05; ward's triangle p<0.02). CONCLUSION: The FaME intervention improves lower limb strength, power and clinically relevant functional outcomes in frequently falling older women
The quantitative measure and statistical distribution of fame
Fame and celebrity play an ever-increasing role in our culture. However,
despite the cultural and economic importance of fame and its gradations, there
exists no consensus method for quantifying the fame of an individual, or of
comparing that of two individuals. We argue that, even if fame is difficult to
measure with precision, one may develop useful metrics for fame that correlate
well with intuition and that remain reasonably stable over time. Using datasets
of recently deceased individuals who were highly renowned, we have evaluated
several internet-based methods for quantifying fame. We find that some
widely-used internet-derived metrics, such as search engine results, correlate
poorly with human subject judgments of fame. However other metrics exist that
agree well with human judgments and appear to offer workable, easily accessible
measures of fame. Using such a metric we perform a preliminary investigation of
the statistical distribution of fame, which has some of the power law character
seen in other natural and social phenomena such as landslides and market
crashes. In order to demonstrate how such findings can generate quantitative
insight into celebrity culture, we assess some folk ideas regarding the
frequency distribution and apparent clustering of celebrity deaths.Comment: 17 pages, 6 figure
On the Google-Fame of Scientists and Other Populations
We study the fame distribution of scientists and other social groups as
measured by the number of Google hits garnered by individuals in the
population. Past studies have found that the fame distribution decays either in
power-law [arXiv:cond-mat/0310049] or exponential [Europhys. Lett., 67, (4)
511-516 (2004)] fashion, depending on whether individuals in the social group
in question enjoy true fame or not. In our present study we examine critically
Google counts as well as the methods of data analysis. While the previous
findings are corroborated in our present study, we find that, in most
situations, the data available does not allow for sharp conclusions.Comment: 6 pages, 1 figure, to appear in the proceedings of the 8th Granada
seminar on Computational Physic
Fatty Acid Methyl Esters as Biosolvents of Epoxy Resins: A Physicochemical Study
The C8 to C18 fatty acid methyl esters (FAME) have been compared as solvents for two epoxy resin pre-polymers, bisphenol A diglycidyl ether (DGEBA) and triglycidyl paminophenol ether (TGPA). It was found that the solubilization limits vary according to the ester and that methyl caprylate is the best solvent of both resins. To explain these solubility performances, physical and chemical properties of FAME were studied, such as the Hansen parameters, viscosity, binary diffusion coefficient and vaporization enthalpy. Determination of the physicochemical parameters of FAME was carried out by laboratory experimentations and by calculation from bibliographic data. The Hansen parameters of FAME and epoxy resins pre-polymers were theoretically and experimentally determined. The FAME chain length showed a long dependence on the binary diffusion parameters and kinematic viscosity, which are mass and momentum transport properties. Moreover, the vaporization enthalpy of these compounds was directly correlated with the solubilization limits
Mapping the substructure in the Galactic halo with the next generation of astrometric satellites
We run numerical simulations of the disruption of satellite galaxies in a
Galactic potential to build up the entire stellar halo, in order to investigate
what the next generation of astrometric satellites will reveal by observing the
halo of the Milky Way. We generate artificial DIVA, FAME and GAIA halo
catalogues, in which we look for the signatures left by the accreted
satellites. We develop a method based on the standard Friends-of-Friends
algorithm applied to the space of integrals of motion. We find this simple
method can recover about 50% of the different accretion events, when the
observational uncertainties expected for GAIA are taken into account, even when
the exact form of the Galactic potential is unknown. The recovery rate for DIVA
and FAME is much smaller, but these missions, like GAIA, should be able to test
the hierarchical formation paradigm on our Galaxy by measuring the amount of
halo substructure in the form of nearby kinematically cold streams with for
example, a two-point correlation function in velocity space.Comment: 10 pages, 9 figures, submitted to MNRAS. High resolution color
figures available from http://www.strw.leidenuniv.nl/~ahelmi/astrom.htm
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