The evolution of free wave packets

We discuss four general features of force-free evolution: (1) The spatial spread of any packet changes with time in a very simple way. (2) Over sufficiently short periods of time (whose duration is related to the spread in momentum of the packet) the probability distribution moves but there is little change in shape. (3) After a sufficiently long period (related to the initial spatial spread) the packet settles into a simple form simply related to the momentum distribution in the packet. In this asymptotic regime, the shape of the probability distribution no longer changes except for its scale, which increases linearly with the time. (4) There is an infinite denumerable set of simple wave packets (the Hermite-Gauss packets) that do not change shape as they evolve.Comment: 6 pages, 4 figures, didactic pape

Recent innovations in UHPLC columns and instrumentation

AbstractTen years after the introduction of the first commercial ultra-high-performance liquid chromatography (UHPLC) system, the pace of progress has not slowed. We describe recent innovations in UHPLC columns and instruments, focusing on those intended primarily for reversed-phase separations of analytes with molecular weights less than about 5000 Daltons, using columns with internal diameters of 2.1 mm. New columns packed with sub-2-µm solid-core particles have produced efficiencies greater than 400,000 plates/m, more than 40% higher than those of columns packed with sub-2-µm fully porous particles. In addition, columns containing charged surface particles give higher peak capacities for separations of positively charged analytes when using the low ionic strength, acidic mobile phases preferred for electrospray mass spectrometric detection. The narrow peaks produced by these columns require instruments having extremely low dispersion. We review recent progress in measuring and reducing system dispersion

A statistic for measuring the balance of a sample

Consider a finite population which has many auxiliary variables. A statistic, which is a function of the moments of the auxiliary variables, is proposed to measure the balance of a sample. The mean and variance of this statistic are derived.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26328/1/0000415.pd

Analytic Tableaux for Simple Type Theory and its First-Order Fragment

We study simple type theory with primitive equality (STT) and its first-order fragment EFO, which restricts equality and quantification to base types but retains lambda abstraction and higher-order variables. As deductive system we employ a cut-free tableau calculus. We consider completeness, compactness, and existence of countable models. We prove these properties for STT with respect to Henkin models and for EFO with respect to standard models. We also show that the tableau system yields a decision procedure for three EFO fragments

Effects of capsinoid ingestion on energy expenditure and lipid oxidation at rest and during exercise

<p>Abstract</p> <p>Background</p> <p>The thermogenic and metabolic properties of capsinoids appear to mimic those of the more pungent sister compound capsaicin. However, few data exist on how capsinoid ingestion affects energy expenditure in humans and no data exist on its interaction with exercise. We aimed to determine how ingestion of capsinoids affected energy expenditure, lipid oxidation and blood metabolites at rest and during moderate intensity exercise.</p> <p>Methods</p> <p>Twelve healthy young men (age = 24.3 ± 3 yr, BMI = 25.5 ± 1.7 kg·m^-2) were studied on two occasions in a double-blind design following ingestion of either placebo or 10 mg of purified capsinoids at rest, after 90 min of cycling at 55% VO₂peak, and for 30 min into recovery. Subjects ingested the capsules 30 min prior to exercise.</p> <p>Results</p> <p>At rest, following ingestion of capsinoids, we observed increases in VO₂and plasma norepinephrine levels, and decreases in concentrations of serum free fatty acids, plasma glycerol and the respiratory exchange ratio (all P < 0.05). At exercise onset, we observed a blunted accumulation of blood lactate with capsinoid ingestion vs. placebo (P < 0.05). There were no other significant differences between the conditions during or post-exercise.</p> <p>Conclusion</p> <p>The ingestion of 10 mg of capsinoids increased adrenergic activity, energy expenditure, and resulted in a shift in substrate utilization toward lipid at rest but had little effect during exercise or recovery. The changes we observed confirm previous data on the thermogenic and metabolic effects of capsinoids at rest and further promote its potential role as an adjunct weight loss aid, in addition to diet and exercise.</p

Dynamic stimuli demonstrate a categorical representation of facial expression in the amygdala

Face-selective regions in the amygdala and posterior superior temporal sulcus (pSTS) are strongly implicated in the processing of transient facial signals, such as expression. Here, we measured neural responses in participants while they viewed dynamic changes in facial expression. Our aim was to explore how facial expression is represented in different face-selective regions. Short movies were generated by morphing between faces posing a neutral expression and a prototypical expression of a basic emotion (either anger, disgust, fear, happiness or sadness). These dynamic stimuli were presented in block design in the following four stimulus conditions: (1) same-expression change, same-identity, (2) same-expression change, different-identity, (3) different-expression change, same-identity, and (4) different-expression change, different-identity. So, within a same-expression change condition the movies would show the same change in expression whereas in the different-expression change conditions each movie would have a different change in expression. Facial identity remained constant during each movie but in the different identity conditions the facial identity varied between each movie in a block. The amygdala, but not the posterior STS, demonstrated a greater response to blocks in which each movie morphed from neutral to a different emotion category compared to blocks in which each movie morphed to the same emotion category. Neural adaptation in the amygdala was not affected by changes in facial identity. These results are consistent with a role of the amygdala in category-based representation of facial expressions of emotion

Factors associated with long-term impact on informal caregivers during Alzheimer's disease dementia progression: 36-month results from GERAS

OBJECTIVE: To identify, in caregivers of patients with Alzheimer's disease (AD) dementia, factors associated with subjective (personal, physical, emotional, and social) and objective (informal caregiver time and costs) caregiver burden. DESIGN: Prospective longitudinal European observational study: post-hoc analysis. SETTING: Clinic. PARTICIPANTS: Community-dwelling patients in France and Germany aged ≥ 55 years (n = 969) with probable AD and their informal caregivers. MEASUREMENTS: Mini-Mental State Examination (MMSE), Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL), 12-item Neuropsychiatric Inventory (NPI-12), Zarit Burden Interview (ZBI), informal caregiver basic and instrumental ADL hours (Resource Utilization in Dementia instrument), and informal caregiver costs. Mixed-effect models of repeated measures (MMRM) were run, including baseline and time-dependent covariates (change from baseline [CFB] to 18 months in MMSE, ADCS-ADL, and NPI-12 scores) associated with CFB in ZBI score/informal caregiver time over 36 months (analyzed using linear regression models) and informal caregiver costs over 36 months (analyzed using generalized linear models). RESULTS: Greater decline in patient function (ADCS-ADL) over 18 months was associated with increased subjective caregiver burden (ZBI), hours, and costs over 36 months. Increased behavioral problems (NPI-12) over 18 months also negatively impacted ZBI. Cognitive decline (MMSE) over 18 months did not affect change in caregiver burden. CONCLUSIONS: Long-term informal caregiver burden was driven by worsening functional abilities and behavioral symptoms but not cognitive decline, over 18 months in community-dwelling patients with AD dementia. Identifying the drivers of caregiver burden could highlight areas in which interventions may benefit both caregivers and patients