Electro-cortical modulations and fronto-parietal activity during motor transitions in the elderly

With aging, bimanual movements are performed with increased cerebral activity in frontal and parietal areas. In contrast, motor switching is poorly documented and is expected to engage increasing resources in the elderly. In this study, spontaneous electroencephalographic activity (EEG) was recorded while 39 young participants (YP) and 37 elderly (EP) performed motor transitions from unimanual tapping to symmetric bimanual tapping (= Activation), and opposite (= Inhibition). We measured the delay of switching using the mean and standard deviation of transition time (meanTT and sdTT). Task-related power (TRPow) in alpha frequency band (8-12Hz) was used to measure electro-cortical changes, negative values corresponding to increased cerebral activity. A balance index (BI) was computed between frontal and parietal regions, values non-significantly different from "zero" representing a comparable level of cerebral activity in these regions. The results reveal higher sdTT 1) in EP compared to YP in both transitions, 2) in Activation compared to Inhibition in both groups. TRPow tends to reach greater negative values (p=0.052) in EP compared to YP in both tapping modes and both motor transitions. Furthermore, the results show more negative TRPow 1) in both motor transitions compared to the tapping movements and 2) in frontal region for YP compared to EP during Inhibition only. BI values differ significantly from "zero" for YP in Inhibition only. In conclusion, motor transitions are more variable and tend to be resource-consuming in the elderly. Moreover, the cerebral activity spreading in EP characterized by similar level of activity between frontal and parietal regions suggest reduced capacity to recruit specialized neural mechanisms during motor inhibition.

Differentiated normalization and drug transitions among rural youth in Ireland.

Prevalence surveys in Ireland indicate an increased trend of youth drug use with rural areas reporting comparable drug availability and prevalence of use in urban settings (Currie, C., Nic Gabhainn, S., Godeau, E., Roberts, C., Smith, R., & Currie, D. (Eds.). (2008). Inequalities in young people's health: HBSC international report from the 2005/2006 survey. Copenhagen: WHO Regional Office for Europe). Few studies have explored the contexts and meaning of drug use on rural youth transitions in terms of increased drug prevalence, recent influx of rural drug activity, normative tolerance of recreational drug consumption and fragmentation of traditional rural communities. Qualitative interviews were conducted with 220 young people (15–17 years), and 78 service providers in a rural area of Ireland, in order to yield contextualized narratives of their experiences of drug use and achieve a wider exploration of processes, drug transitions and realities of rural youth. The thematic analysis of the research described varied pathways, attitudes and typologies of rural youth drug use, ranging from abstinent, recreational and moderated to maturing out. The research suggests support for a ‘differentiated’ normalization theory (Shildrick, T. (2002). Young people, illicit drug use and the question of normalisation theory. Journal of Youth Studies, 5, 35–48) in terms of consumerist and normative rural youth drug use transitions in their negotiation of risk within integrating rural and urban dichotomies. In conclusion, it is recommended that drug education programmes need to situate localized rural drug taking behaviours within a wider understanding of rural community life.This resource was contributed by The National Documentation Centre on Drug Use.

Poverty and Transitions in Health

Being objectively low income leads to poor health and a shorter life. But poverty can also be a matter of subjectively feeling poor. WZB economist Maja Adena and her colleague Michal Myck (DIW Berlin and the Center for Economic Analysis, CenEA, Szczecin) have substantiated how the subjective assessment of being poor affects the health of the 50+ age group. Read more here.

Selective three-dimensional visualization of the coronary arterial lumen using arterial spin tagging.

Conventional coronary magnetic resonance angiography (MRA) techniques display the coronary blood-pool along with the surrounding structures, including the myocardium, the ventricular and atrial blood-pool, and the great vessels. This representation of the coronary lumen is not directly analogous to the information provided by x-ray coronary angiography, in which the coronary lumen displayed by iodinated contrast agent is seen. Analogous "luminographic" data may be obtained using MR arterial spin tagging (projection coronary MRA) techniques. Such an approach was implemented using a 2D selective "pencil" excitation for aortic spin tagging in concert with a 3D interleaved segmented spiral imaging sequence with free-breathing, and real-time navigator technology. This technique allows for selective 3D visualization of the coronary lumen blood-pool, while signal from the surrounding structures is suppressed.

Des pratiques d'ingénierie aux transitions sociotechniques. Retour sur la notion d'ingénierie hétérogène dans le cas des micro- et nanotechnologies

Cet article rend compte du travail d'ingénierie dans le domaine des micro- et nanotechnologies (MNT) en explorant une diversité de lieux où technologies et sociétés sont coproduites : comités internationaux où sont définies des feuilles de route (roadmap), laboratoires de recherche où sont conçus de nouveaux dispositifs, plates-formes d'exploration et de transfert des nouvelles technologies vers l'industrie, grands programmes de recherche où chercheurs et entreprises façonnent des infrastructures sociotechniques et régulent l'inscription sociétale des nouveautés techniques. Il utilise le concept d'« ingénierie hétérogène » (Law, 1989) afin d'expliquer la capacité de transformation sociale des pratiques d'ingénierie. Il montre ainsi que la théorie de l'acteur-réseau peut produire une description des mécanismes à l'oeuvre lors d'une transition sociotechnique, depuis la construction de projets de laboratoire jusqu'à leur inscription dans la société, sans pour autant renoncer à « suivre les acteurs » - notamment les ingénieurs - et leurs pratiques concrètes et situées.

Three-dimensional high-resolution fast spin-echo coronary magnetic resonance angiography.

Due to SNR constraints, current "bright-blood" 3D coronary MRA approaches still suffer from limited spatial resolution when compared to conventional x-ray coronary angiography. Recent 2D fast spin-echo black-blood techniques maximize signal for coronary MRA at no loss in image spatial resolution. This suggests that the extension of black-blood coronary MRA with a 3D imaging technique would allow for a further signal increase, which may be traded for an improved spatial resolution. Therefore, a dual-inversion 3D fast spin-echo imaging sequence and real-time navigator technology were combined for high-resolution free-breathing black-blood coronary MRA. In-plane image resolution below 400 microm was obtained. Magn Reson Med 45:206-211, 2001.

Kinematics and dynamic complexity of postural transitions in frail elderly subjects.

The aim of this study was to propose a methodology allowing a detailed characterization of body sit-to-stand/stand-to-sit postural transition. Parameters characterizing the kinematics of the trunk movement during sit-to-stand (Si-St) postural transition were calculated using one initial sensor system fixed on the trunk and a data logger. Dynamic complexity of these postural transitions was estimated by fractal dimension of acceleration-angular velocity plot. We concluded that this method provides a simple and accurate tool for monitoring frail elderly and to objectively evaluate the efficacy of a rehabilitation program.

Free-breathing renal magnetic resonance angiography with steady-state free-precession and slab-selective spin inversion combined with radial k-space sampling and water-selective excitation.

The impact of radial k-space sampling and water-selective excitation on a novel navigator-gated cardiac-triggered slab-selective inversion prepared 3D steady-state free-precession (SSFP) renal MR angiography (MRA) sequence was investigated. Renal MRA was performed on a 1.5-T MR system using three inversion prepared SSFP approaches: Cartesian (TR/TE: 5.7/2.8 ms, FA: 85 degrees), radial (TR/TE: 5.5/2.7 ms, FA: 85 degrees) SSFP, and radial SSFP combined with water-selective excitation (TR/TE: 9.9/4.9 ms, FA: 85 degrees). Radial data acquisition lead to significantly reduced motion artifacts (P < 0.05). SNR and CNR were best using Cartesian SSFP (P < 0.05). Vessel sharpness and vessel length were comparable in all sequences. The addition of a water-selective excitation could not improve image quality. In conclusion, radial k-space sampling reduces motion artifacts significantly in slab-selective inversion prepared renal MRA, while SNR and CNR are decreased. The addition of water-selective excitation could not improve the lower CNR in radial scanning.

Multi-parametric evaluation of sit-to-stand and stand-to-sit transitions in elderly people.

The aim of this study was to extract multi-parametric measures characterizing different features of sit-to-stand (Si-St) and stand-to-sit (St-Si) transitions in older persons, using a single inertial sensor attached to the chest. Investigated parameters were transition's duration, range of trunk tilt, smoothness of transition pattern assessed by its fractal dimension, and trunk movement's dynamic described by local wavelet energy. A measurement protocol with a Si-St followed by a St-Si postural transition was performed by two groups of participants: the first group (N=79) included Frail Elderly subjects admitted to a post-acute rehabilitation facility and the second group (N=27) were healthy community-dwelling elderly persons. Subjects were also evaluated with Tinetti's POMA scale. Compared to Healthy Elderly persons, frail group at baseline had significantly longer Si-St (3.85±1.04 vs. 2.60±0.32, p=0.001) and St-Si (4.08±1.21 vs. 2.81±0.36, p=0.001) transition's duration. Frail older persons also had significantly decreased smoothness of Si-St transition pattern (1.36±0.07 vs. 1.21±0.05, p=0.001) and dynamic of trunk movement. Measurements after three weeks of rehabilitation in frail older persons showed that smoothness of transition pattern had the highest improvement effect size (0.4) and discriminative performance. These results demonstrate the potential interest of such parameters to distinguish older subjects with different functional and health conditions.

Transitions familiales et brouilles conjugales : cumulation ou compensation des problèmes d'intimité à travers les phases du parcours de vie familial ?

Cette étude esquisse, sur la base d'un grand échantillon représentatif et longitudinal de couples vivant en Suisse et du point de vue des femmes ayant répondu à l'enquête, un tableau de l'évolution des problèmes conjugaux rencontrés au cours des différentes phases de la vie familiale. Le processus de dégradation de la relation est reconstitué à partir de 2 mesures faites dans un intervalle de 5 ans. La genèse des difficultés conjugales est considérée à travers le prisme des transitions familiales, en particulier la naissance des enfants, leur entrée à l'école et leur départ du domicile parental. L'analyse révèle le potentiel déstabilisateur de ces transitions pour le couple. Les bouleversements de l'équilibre relationnel évoluent, dans certains cas, vers un cumul de difficultés qui envahissent l'espace conjugal pour déboucher sur une situation rapidement inextricable.

A new all-round density functional based on spin states and SN2 barriers

We report here a new empirical density functional that is constructed based on the performance of OPBE and PBE for spin states and SN 2 reaction barriers and how these are affected by different regions of the reduced gradient expansion. In a previous study [Swart, Sol̀, and Bickelhaupt, J. Comput. Methods Sci. Eng. 9, 69 (2009)] we already reported how, by switching between OPBE and PBE, one could obtain both the good performance of OPBE for spin states and reaction barriers and that of PBE for weak interactions within one and the same (SSB-sw) functional. Here we fine tuned this functional and include a portion of the KT functional and Grimme's dispersion correction to account for π- π stacking. Our new SSB-D functional is found to be a clear improvement and functions very well for biological applications (hydrogen bonding, π -π stacking, spin-state splittings, accuracy of geometries, reaction barriers)

Transitions in partnership and parental status, gender, and political and civic participation

Participation research has documented the effect of partner and parenthood status, thereby ignoring the dynamic aspect of status changes. Based on theoretical insights on changes in political resources and interest, this study looks at partnership and parenthood as dynamic characteristics. Using data from the Swiss Household Panel (SHP), it examines to what extent important life-cycle transitions in partnership and parental status influence various forms of political and civic participation and whether they affect men and women's participation differently. Our regression analyses reveal that particularly the entry into separation or divorce is a main key point driving change in political and civic participation. Its effect is also highly gendered. Following separation, women participate less in voting, whereas men's participation rates are not affected in a negative way. Separation even increases men's level of anticipated activism. Children entering or leaving the household do not seem to represent key points of change in political and civic participation of the couple. Yet, the transition to having school-aged children significantly increases some types of participation, at least for women.