Changes in leisure time and occupational physical activity over 8 years: The Cornellà health Interview Survey Follow-Up Study

Aim: To describe changes in leisure time and occupational physical activity status in an urban Mediterranean population-based cohort, and to evaluate sociodemographic, health-related and lifestyle correlates of such changes. Methods: Data for this study come from the Cornellè Health Interview Survey Follow-Up Study, a prospective cohort study of a representative sample (n¿=¿2500) of the population. Participants in the analysis reported here include 1246 subjects (567 men and 679 women) who had complete data on physical activity at the 1994 baseline survey and at the 2002 follow-up. We fitted Breslow-Cox regression models to assess the association between correlates of interest and changes in physical activity. Results: Regarding leisure time physical activity, 61.6% of cohort members with ¿sedentary¿ habits in 1994 changed their status to ¿light/moderate¿ physical activity in 2002, and 70% who had ¿light/moderate¿ habits in 1994 did not change their activity level. Regarding occupational physical activity, 74.4% of cohort members who were ¿active¿ did not change their level of activity, and 64.3% of participants with ¿sedentary¿ habits in 1994 changed to ¿active¿ occupational physical activity. No clear correlates of change in physical activity were identified in multivariate analyses. Conclusion: While changes in physical activity are evident in this population-based cohort, no clear determinants of such changes were recognised. Further longitudinal studies including other potential individual and contextual determinants are needed to better understand determinants of changes in physical activity at the population level.

Regional specificity of MRI contrast parameter changes in normal ageing revealed by voxel-based quantification (VBQ).

Normal ageing is associated with characteristic changes in brain microstructure. Although in vivo neuroimaging captures spatial and temporal patterns of age-related changes of anatomy at the macroscopic scale, our knowledge of the underlying (patho)physiological processes at cellular and molecular levels is still limited. The aim of this study is to explore brain tissue properties in normal ageing using quantitative magnetic resonance imaging (MRI) alongside conventional morphological assessment. Using a whole-brain approach in a cohort of 26 adults, aged 18-85years, we performed voxel-based morphometric (VBM) analysis and voxel-based quantification (VBQ) of diffusion tensor, magnetization transfer (MT), R1, and R2* relaxation parameters. We found age-related reductions in cortical and subcortical grey matter volume paralleled by changes in fractional anisotropy (FA), mean diffusivity (MD), MT and R2*. The latter were regionally specific depending on their differential sensitivity to microscopic tissue properties. VBQ of white matter revealed distinct anatomical patterns of age-related change in microstructure. Widespread and profound reduction in MT contrasted with local FA decreases paralleled by MD increases. R1 reductions and R2* increases were observed to a smaller extent in overlapping occipito-parietal white matter regions. We interpret our findings, based on current biophysical models, as a fingerprint of age-dependent brain atrophy and underlying microstructural changes in myelin, iron deposits and water. The VBQ approach we present allows for systematic unbiased exploration of the interaction between imaging parameters and extends current methods for detection of neurodegenerative processes in the brain. The demonstrated parameter-specific distribution patterns offer insights into age-related brain structure changes in vivo and provide essential baseline data for studying disease against a background of healthy ageing.

An index of 5-HT synthesis changes during early antidepressant treatment: α-[11C]methyl-l-tryptophan PET study

The antidepressant selective serotonin transporter inhibitors (SSRIs) are clinically active after a delay of several weeks. Indeed, the rapid increase of serotonin (5-HT) caused by SSRIs, stimulates the 5-HT1A autoreceptors, which exert a negative feedback on the 5-HT neurotransmission. Only when autoreceptors are desensitized, can SSRIs exert their therapeutic activity. The 5-HT1A receptor antagonist pindolol has been used to accelerate the clinical effects of antidepressant by preventing the negative feedback. Using the a-[11C]methyl-L-tryptophan/positron emission tomography (PET), the goal of the present double-blind, randomized study was to compare the changes in a-[11C]methyl-L-tryptophan trapping, an index of serotonin synthesis, in patients suffering from unipolar depression treated with the SSRI citalopram (20 mg/day) plus placebo versus patients treated with citalopram plus pindol (7.5 mg/day). PET and Hamilton depression rating scale (HDRS-17) were performed at baseline, and after 10 and 24 days of antidepressant treatment. Results show that the combination citalopram plus pindol, compared to citalopram alone shows a more rapid and greater increase of an index of 5-HT synthesis in prefrontal cortex (BA 9). This research is the first human PET study demonstrating that, after 24 days, the combination SSRIs plus pindolol produces a greater increase of the metabolism of serotonin in the prefrontal cortex, an area associated to depressive symptoms.

Changes over time in risk factors for cardiovascular disease and use of lipid-lowering drugs in HIV-infected individuals and impact on myocardial infarction.

BACKGROUND: Because of the known relationship between exposure to combination antiretroviral therapy and cardiovascular disease (CVD), it has become increasingly important to intervene against risk of CVD in human immunodeficiency virus (HIV)-infected patients. We evaluated changes in risk factors for CVD and the use of lipid-lowering therapy in HIV-infected individuals and assessed the impact of any changes on the incidence of myocardial infarction. METHODS: The Data Collection on Adverse Events of Anti-HIV Drugs Study is a collaboration of 11 cohorts of HIV-infected patients that included follow-up for 33,389 HIV-infected patients from December 1999 through February 2006. RESULTS: The proportion of patients at high risk of CVD increased from 35.3% during 1999-2000 to 41.3% during 2005-2006. Of 28,985 patients, 2801 (9.7%) initiated lipid-lowering therapy; initiation of lipid-lowering therapy was more common for those with abnormal lipid values and those with traditional risk factors for CVD (male sex, older age, higher body mass index [calculated as the weight in kilograms divided by the square of the height in meters], family and personal history of CVD, and diabetes mellitus). After controlling for these, use of lipid-lowering drugs became relatively less common over time. The incidence of myocardial infarction (0.32 cases per 100 person-years [PY]; 95% confidence interval [CI], 0.29-0.35 cases per 100 PY) appeared to remain stable. However, after controlling for changes in risk factors for CVD, the rate decreased over time (relative rate in 2003 [compared with 1999-2000], 0.73 cases per 100 PY [95% CI, 0.50-1.05 cases per 100 PY]; in 2004, 0.64 cases per 100 PY [95% CI, 0.44-0.94 cases per 100 PY]; in 2005-2006, 0.36 cases per 100 PY [95% CI, 0.24-0.56 cases per 100 PY]). Further adjustment for lipid levels attenuated the relative rates towards unity (relative rate in 2003 [compared with 1999-2000], 1.06 cases per 100 PY [95% CI, 0.63-1.77 cases per 100 PY]; in 2004, 1.02 cases per 100 PY [95% CI, 0.61-1.71 cases per 100 PY]; in 2005-2006, 0.63 cases per 100 PY [95% CI, 0.36-1.09 cases per 100 PY]). CONCLUSIONS: Although the CVD risk profile among patients in the Data Collection on Adverse Events of Anti-HIV Drugs Study has decreased since 1999, rates have remained relatively stable, possibly as a result of a more aggressive approach towards managing the risk of CVD.

How are Spanish academics coping with changes? Responses from a life histories research.

[eng] This report is part of the research project, The effects of social changes in work and professional life of Spanish academics, partially financed by the Spanish Ministry of Science and Innovation (SEJ2006-01876), that has explored change in legislation, organisation, research schemes and so on, in the last thirty years. The main aim of this project is deepening our understanding of the impact of undergoing economic, social, cultural, technological and labour change in Spanish universities in the life and professional identity of the teaching and research staff, taking into account the national and european context. This paper gathers part of the results gained from the project, being its primary objective to contribute to an improved knowledge-base on professional knowledge and work experience in higher education institutions in Spain and, as a consequence, to understand how Spanish academics are coping with current changes.

Hometown architecture : changes in Central Iowa towns and farms,1981.

This book is a product of a two year project, the extensive surveys CIRALG and the Division of Historic Preservation undertook to identify culturally significant structures in central Iowa. It discloses the aspirations, tastes, building abilities and needs of earlier Iowans.

Learning-induced plasticity in auditory spatial representations revealed by electrical neuroimaging.

Auditory spatial representations are likely encoded at a population level within human auditory cortices. We investigated learning-induced plasticity of spatial discrimination in healthy subjects using auditory-evoked potentials (AEPs) and electrical neuroimaging analyses. Stimuli were 100 ms white-noise bursts lateralized with varying interaural time differences. In three experiments, plasticity was induced with 40 min of discrimination training. During training, accuracy significantly improved from near-chance levels to approximately 75%. Before and after training, AEPs were recorded to stimuli presented passively with a more medial sound lateralization outnumbering a more lateral one (7:1). In experiment 1, the same lateralizations were used for training and AEP sessions. Significant AEP modulations to the different lateralizations were evident only after training, indicative of a learning-induced mismatch negativity (MMN). More precisely, this MMN at 195-250 ms after stimulus onset followed from differences in the AEP topography to each stimulus position, indicative of changes in the underlying brain network. In experiment 2, mirror-symmetric locations were used for training and AEP sessions; no training-related AEP modulations or MMN were observed. In experiment 3, the discrimination of trained plus equidistant untrained separations was tested psychophysically before and 0, 6, 24, and 48 h after training. Learning-induced plasticity lasted <6 h, did not generalize to untrained lateralizations, and was not the simple result of strengthening the representation of the trained lateralizations. Thus, learning-induced plasticity of auditory spatial discrimination relies on spatial comparisons, rather than a spatial anchor or a general comparator. Furthermore, cortical auditory representations of space are dynamic and subject to rapid reorganization.

Geochemical changes at the Permian-Triassic transition in Southern Alps and adjacent area: a review

Compilation of the recent literature from the Southern Alps and adjacent area confirms the geochemical variations of unusual amplitudes during the Permian-Triassic boundary interval (PTBI). A great attention has been given to the negative δ13C anomaly within the Tesero Member close to the Permian-Triassic boundary. Very detailed geochemical works have been done on the scientific Gartnerkofel core (Gk-1) and on the Slovenian sections. Major minor and rare earth elements (REE) data are reported and show a marked enrichment in alkaline metals and REE of some levels of the boundary interval. But recent studies show that the low Iridium anomalies and the Osmium and Helium isotopes anomalies lack the characteristics of a large extraterrestrial impact.

Changes in anatomy and root cell ultrastructure of soybean genotypes under manganese stress

The deleterious effects of both Mn deficiency and excess on the development of plants have been evaluated with regard to aspects of shoot anatomy, ultrastructure and biochemistry, focusing mainly on the manifestation of visual symptoms. However, there is little information in the literature on changes in the root system in response to Mn supply. The objective of this study was to evaluate the effects of Mn doses (0.5, 2.0 and 200.0 μmol L-1) in a nutrient solution on the anatomy of leaves and roots of the Glycine max (L.) cultivars Santa Rosa, IAC-15 and IAC-Foscarin 31. Visual deficiency symptoms were first observed in Santa Rosa and IAC-15, which were also the only cultivars where Mn-toxicity symptoms were observed. Only in IAC-15, a high Mn supply led to root diameter thickening, but without alteration in cells of the bark, epidermis, exodermis and endodermis. The degree of disorganization of the xylem vessels, in particular the metaxylem, differed in the cultivars. Quantity and shape of the palisade parenchyma cells were influenced by both Mn deficiency and toxicity. A reduction in the number of chloroplasts was observed in the three Mn-deficient genotypes. The anatomical alterations in IAC-15 due to nutritional stress were greater, as expressed in extensive root cell cytoplasm disorganization and increased vacuolation at high Mn doses. The degree of changes in the anatomical and ultrastructural organization of roots and leaves of the soybean genotypes studied differed, suggesting the existence of tolerance mechanisms to different intensities of Mn deficiency or excess.

Hydrogen-induced changes in the breakdown voltage of InP HEMTs

In this work, electrical measurements show that the breakdown voltage,BVDG, of InP HEMTs increases following exposure to H2. This BVDG shift is nonrecoverable. The increase in BVDG is found to be due to a decrease in the carrier concentration in the extrinsic portion of the device.We provide evidence that H2 reacts with the exposed InAlAs surface in the extrinsic region next to the gate, changing the underlying carrier concentration. Hall measurements of capped and uncapped HEMT samples show that the decrease in sheet carrier concentration can be attributed to a modification of the exposed InAlAs surface. Consistent with this, XPS experiments on uncapped heterostructures give evidence of As loss from the InAlAs surface upon exposure to hydrogen.

Changes in the use of broad-spectrum antibiotics after withdrawal of cefepime from the market: an interrupted time series analysis

Background and objective: Cefepime was one of the most used broad-spectrum antibiotics in Swiss public acute care hospitals. The drug was withdrawn from market in January 2007, and then replaced by a generic since October 2007. The goal of the study was to evaluate changes in the use of broad-spectrum antibiotics after the withdrawal of the cefepime original product. Design: A generalized regression-based interrupted time series model incorporating autocorrelated errors assessed how much the withdrawal changed the monthly use of other broad-spectrum antibiotics (ceftazidime, imipenem/cilastin, meropenem, piperacillin/ tazobactam) in defined daily doses (DDD)/100 bed-days from January 2004 to December 2008 [1, 2]. Setting: 10 Swiss public acute care hospitals (7 with\200 beds, 3 with 200-500 beds). Nine hospitals (group A) had a shortage of cefepime and 1 hospital had no shortage thanks to importation of cefepime from abroad. Main outcome measures: Underlying trend of use before the withdrawal, and changes in the level and in the trend of use after the withdrawal. Results: Before the withdrawal, the average estimated underlying trend (coefficient b1) for cefepime was decreasing by -0.047 (95% CI -0.086, -0.009) DDD/100 bed-days per month and was significant in three hospitals (group A, P\0.01). Cefepime withdrawal was associated with a significant increase in level of use (b2) of piperacillin/tazobactam and imipenem/cilastin in, respectively, one and five hospitals from group A. After the withdrawal, the average estimated trend (b3) was greatest for piperacillin/tazobactam (+0.043 DDD/100 bed-days per month; 95% CI -0.001, 0.089) and was significant in four hospitals from group A (P\0.05). The hospital without drug shortage showed no significant change in the trend and the level of use. The hypothesis of seasonality was rejected in all hospitals. Conclusions: The decreased use of cefepime already observed before its withdrawal from the market could be explained by pre-existing difficulty in drug supply. The withdrawal of cefepime resulted in change in level for piperacillin/tazobactam and imipenem/cilastin. Moreover, an increase in trend was found for piperacillin/tazobactam thereafter. As these changes generally occur at the price of lower bacterial susceptibility, a manufacturers' commitment to avoid shortages in the supply of their products would be important. As perspectives, we will measure the impact of the changes in cost and sensitivity rates of these antibiotics.