Unhappiness, health and cognitive ability in old age

Background To test whether scores on depression inventories on entry to a longitudinal study predict mental ability over the next 4–16 years. Method Associations between scores on the Beck Depression Inventory and on tests of intelligence, vocabulary and memory were analysed in 5070 volunteers aged 49–93 years after differences in prescribed drug consumption, death and drop-out, sex, socio-economic advantage and recruitment cohort effects had also been considered. Results On all cognitive tasks Beck scores on entry, even in the range 0–7 indicating differences in above average contentment, affected overall levels of cognitive performance but not rates of age-related cognitive decline suggesting effects of differences in life satisfaction rather than in depression. Conclusions A new finding is that, in old age, increments in life satisfaction are associated with better cognitive performance. Implications for interpreting associations between depression inventory scores and cognitive performance in elderly samples are discussed

The Supplemental Nutrition Assistance Program and Food Insecurity

This chapter reviews recent theory and empirical evidence regarding the effect of SNAP on food insecurity and replicates the modelling strategies used in the empirical literature. The authors find that recent evidence suggesting an ameliorative effect of SNAP on food insecurity may not be robust to specification choice or data. Most specifications mirror the existing literature in finding a positive association of food insecurity with SNAP participation. Two-stage least squares and control function methods do show that SNAP reduces food insecurity, but effects are not consistent across sub-populations and are not always statistically significant

Child Injuries and the Timing of SNAP Benefits Receipt

The Supplemental Nutrition Assistance Program (SNAP) is an important federal resource that provides nutritional assistance to low-income families. Timing of SNAP benefits can reduce childhood injuries

Ensemble of Hankel Matrices for Face Emotion Recognition

In this paper, a face emotion is considered as the result of the composition of multiple concurrent signals, each corresponding to the movements of a specific facial muscle. These concurrent signals are represented by means of a set of multi-scale appearance features that might be correlated with one or more concurrent signals. The extraction of these appearance features from a sequence of face images yields to a set of time series. This paper proposes to use the dynamics regulating each appearance feature time series to recognize among different face emotions. To this purpose, an ensemble of Hankel matrices corresponding to the extracted time series is used for emotion classification within a framework that combines nearest neighbor and a majority vote schema. Experimental results on a public available dataset shows that the adopted representation is promising and yields state-of-the-art accuracy in emotion classification.Comment: Paper to appear in Proc. of ICIAP 2015. arXiv admin note: text overlap with arXiv:1506.0500

Three essays in health and nutrition economics

This dissertation focuses on aspects of behavior and public policy related to vulnerable populations. The first essay, coauthored with Christian Gregory and David C. Ribar, reviews recent theory and empirical evidence regarding the effect of Supplemental Nutrition Assistance Program (SNAP) participation on food insecurity and replicates the modelling strategies used in the empirical literature. We find that recent evidence suggesting the ameliorative effect of SNAP on food insecurity may not be robust to specification choice or data. Most specifications mirror the existing literature in finding a positive association of food insecurity with SNAP participation. Two-stage least squares and control function methods do show that SNAP reduces food insecurity, but effects are not consistent across sub-populations and are not always statistically significant. In the second essay, I examine the relationship between SNAP participation and food insecurity using data from the 2001-2008 Current Population Survey (CPS-FSS). A behavioral Rasch selection model is proposed and estimated using four subsamples of low-income households: unmarried parent households, married parent households, all-elderly households, and other adult-only households. The behavioral Rasch selection model assumes responses to multiple food hardship questions may be modelled as indicators of a single underlying index of food hardships, and concurrently, controls for the endogeneity of program participation. Simultaneously modelling the outcomes this way leads to more efficient estimation. The models are identified using exogenous changes in state-level polices related to SNAP. The results suggest that SNAP has a strong ameliorative effect on food insecurity for married parent households, all-elderly households, and other adult-only households, while SNAP continues to be associated with greater food hardships for unmarried parent households. Participating in SNAP reduces the probability of food insecurity by 22.4% for other adult-only households, 18% for all-elderly households, and 17% for married parent households. The third and final essay examines the relationship between underage college drinking and the initial occupational choices of male college graduates using data from the National Longitudinal Survey of Youth 1997 (NLSY97). Focusing on recent college graduates and their initial occupational choices allows me to address important timing issues not considered by the existing literature. For the multivariate analyses, I estimate multinomial logistic models of occupational choice, where the occupational choice set is specified as employed full-time in white collar occupations, other occupations, enrolled in school, and neither in school nor employed full-time. In addition, I estimate multinomial logistic selection models that control for the potential endogeneity of underage drinking. The results suggest underage college drinking is not associated with young men's initial occupational choices, with the exception of the decision to be enrolled in school. Young men with any underage college days where they drank two or more drinks are 28.9% less likely to be enrolled in school after completing a bachelor's degree

Cognitive tests used in chronic adult human randomised controlled trial micronutrient and phytochemical intervention studies

In recent years there has been a rapid growth of interest in exploring the relationship between nutritional therapies and the maintenance of cognitive function in adulthood. Emerging evidence reveals an increasingly complex picture with respect to the benefits of various food constituents on learning, memory and psychomotor function in adults. However, to date, there has been little consensus in human studies on the range of cognitive domains to be tested or the particular tests to be employed. To illustrate the potential difficulties that this poses, we conducted a systematic review of existing human adult randomised controlled trial (RCT) studies that have investigated the effects of 24 d to 36 months of supplementation with flavonoids and micronutrients on cognitive performance. There were thirty-nine studies employing a total of 121 different cognitive tasks that met the criteria for inclusion. Results showed that less than half of these studies reported positive effects of treatment, with some important cognitive domains either under-represented or not explored at all. Although there was some evidence of sensitivity to nutritional supplementation in a number of domains (for example, executive function, spatial working memory), interpretation is currently difficult given the prevailing 'scattergun approach' for selecting cognitive tests. Specifically, the practice means that it is often difficult to distinguish between a boundary condition for a particular nutrient and a lack of task sensitivity. We argue that for significant future progress to be made, researchers need to pay much closer attention to existing human RCT and animal data, as well as to more basic issues surrounding task sensitivity, statistical power and type I error

Local and systemic glucocorticoid metabolism in inflammatory arthritis

Background: Isolated, primary synovial fibroblasts generate active glucocorticoids through expression of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). This enzyme produces cortisol from inactive cortisone (and prednisolone from prednisone). Objective: To determine how intact synovial tissue metabolises glucocorticoids and to identify the local and systemic consequences of this activity by examination of glucocorticoid metabolism in patients with rheumatoid arthritis (RA). Methods: Synovial tissue was taken from patients with RA during joint replacement surgery. Glucocorticoid metabolism in explants was assessed by thin-layer chromatography and specific enzyme inhibitors. RT-PCR and immunohistochemistry were used to determine expression and distribution of 11β-HSD enzymes. Systemic glucocorticoid metabolism was examined in patients with RA using gas chromatography/mass spectrometry. Results: Synovial tissue synthesised cortisol from cortisone, confirming functional 11β-HSD1 expression. In patients with RA, enzyme activity correlated with donor erythrocyte sedimentation rate (ESR). Synovial tissues could also convert cortisol back to cortisone. Inhibitor studies and immunohistochemistry suggested this was owing to 11β-HSD2 expression in synovial macrophages, whereas 11β-HSD1 expression occurred primarily in fibroblasts. Synovial fluids exhibited lower cortisone levels than matched serum samples, indicating net local steroid activation. Urinary analyses indicated high 11β-HSD1 activity in untreated patients with RA compared with controls and a significant correlation between total body 11β-HSD1 activity and ESR. Conclusions: Synovial tissue metabolises glucocorticoids, the predominant effect being glucocorticoid activation, and this increases with inflammation. Endogenous glucocorticoid production in the joint is likely to have an impact on local inflammation and bone integrity

Dynamic displacement of normal and detached semicircular canal cupula

© 2009 The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in JARO - Journal of the Association for Research in Otolaryngology 10 (2009): 497-509, doi:10.1007/s10162-009-0174-y.The dynamic displacement of the semicircular canal cupula and modulation of afferent nerve discharge were measured simultaneously in response to physiological stimuli in vivo. The adaptation time constant(s) of normal cupulae in response to step stimuli averaged 36 s, corresponding to a mechanical lower corner frequency for sinusoidal stimuli of 0.0044 Hz. For stimuli equivalent to 40–200 deg/s of angular head velocity, the displacement gain of the central region of the cupula averaged 53 nm per deg/s. Afferents adapted more rapidly than the cupula, demonstrating the presence of a relaxation process that contributes significantly to the neural representation of angular head motions by the discharge patterns of canal afferent neurons. We also investigated changes in time constants of the cupula and afferents following detachment of the cupula at its apex—mechanical detachment that occurs in response to excessive transcupular endolymph pressure. Detached cupulae exhibited sharply reduced adaptation time constants (300 ms–3 s, n = 3) and can be explained by endolymph flowing rapidly over the apex of the cupula. Partially detached cupulae reattached and normal afferent discharge patterns were recovered 5–7 h following detachment. This regeneration process may have relevance to the recovery of semicircular canal function following head trauma.Financial support was provided by the NIDCD R01 DC06685 (Rabbitt) and NASA GSRP 56000135 & NSF IGERT DGE- 9987616 (Breneman)

Specific and general autobiographical knowledge in adults with autism spectrum disorders: The role of personal goals

Autobiographical knowledge is stored hierarchically, at both specific and general levels of representation. It has also been proposed that the self is the structure around which autobiographical memories are organised. The current series of studies assessed whether the autobiographical memory difficulties observed in adults with autism spectrum disorders (ASD) could be due to problems in using the self as an effective memory cue. A series of cueing paradigms were used to assess the accessibility of both specific and general autobiographical knowledge relating to (i) currently pursued goals (either high or low in self-concordance) and (ii) goals that participants were not currently pursuing. Results demonstrated that while event-specific knowledge was impaired in the ASD group, general event knowledge appeared relatively intact. Moreover, while both event-specific and general event knowledge were organised around goals of the self in control participants, a corresponding relationship was only observed for general event knowledge in the ASD group

Synergistic induction of local glucocorticoid generation by inflammatory cytokines and glucocorticoids: implications for inflammation associated bone loss

Objectives: Synovial fibroblasts and osteoblasts generate active glucocorticoids by means of the 11aβ-hydroxysteroid dehydrogenase type 1 (11aβ-HSD1) enzyme. This activity increases in response to proinflammatory cytokines or glucocorticoids. During inflammatory arthritis synovium and bone are exposed to both these factors. This study hypothesised that glucocorticoids magnify the effects of inflammatory cytokines on local glucocorticoid production in both synovium and bone. Methods: The effects of inflammatory cytokines (IL-1aβ/tumour necrosis factor alpha; TNFα) and glucocorticoids, alone or combined, were assessed on the expression and activity of 11β-HSD1 in primary synovial fibroblasts, primary human osteoblasts and MG-63 osteosarcoma cells. A range of other target genes and cell types were used to examine the specificity of effects. Functional consequences were assessed using IL-6 ELISA. Results: In synovial fibroblasts and osteoblasts, treatment with cytokines or glucocorticoids in isolation induced 11β-HSD1 expression and activity. However, in combination, 11β-HSD1 expression, activity and functional consequences were induced synergistically to a level not seen with isolated treatments. This effect was seen in normal skin fibroblasts but not foreskin fibroblasts or adipocytes and was only seen for the 11β-HSD1 gene. Synergistic induction had functional consequences on IL-6 production. Conclusions: Combined treatment with inflammatory cytokines and glucocorticoids synergistically induces 11aβ-HSD1 expression and activity in synovial fibroblasts and osteoblasts, providing a mechanism by which synovium and bone can interact to enhance anti-inflammatory responses by increasing localised glucocorticoid levels. However, the synergistic induction of 11β-HSD1 might also cause detrimental glucocorticoid accumulation in bone or surrounding tissues