Noninvasive monitoring of radiotherapy-induced microvascular changes using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in a colorectal tumor model

To examine dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with a macromolecular contrast agent (P792) to visualize effects of radiotherapy (RT) on microvascular leakage in a colorectal cancer model.Journal Articleinfo:eu-repo/semantics/publishe

Future perspectives on the role of extended producer responsibility within a circular economy: A Delphi study using the case of the Netherlands

Extended producer responsibility (EPR) is a proposed policy approach to promoting the circular economy (CE) within the European Union. This research used a policy Delphi to explore perspectives on improving EPR policies to further contribute to the CE goals of the Netherlands. Both the potential improvement and critical reflections discussed by CE and EPR experts and practitioners from this study contribute to a more detailed understanding of the future governance of CE practices. We present various activities to improve EPR and insights from Delphi participants that emerged from the study. This paper shows that whilst actors agree, in essence, that there is a need for modifying EPR, what the specific changes to the form are and to whom the new responsibilities apply is contested

Episodic memory encoding in middle age: effects of ageing and cognitive fatigue on brain activation

Klaassen, E., Evers, E., De Groot, R. H. M., Veltman, D., & Jolles, J. (2011, September). Episodic memory encoding in middle age: effects of ageing and cognitive fatigue on brain activation. Poster presented at the Annual meeting for the international society for neuroimaging in psychiatry, Heidelberg, Germany.Healthy cognitive aging is thought to impact most heavily on episodic memory [1]. However, changes in episodic memory prior to the age of 60 are more controversial than changes in older adults [2]. Furthermore, cognitive decline already present in middle age may not yet manifest in behavior due to the action of neural compensation processes that preserve performance at the behavioral level. Therefore, fMRI can provide valuable insights into age-related changes present in middle age [3]. It is also important to determine the extent to which middle-aged adults must compensate for the effects of cognitive aging in order to maintain performance not just in the short-term, but following sustained, fatigue inducing task performance likely, for example, to be commonly encountered during the workday. Therefore, in the current study, each participant was tested twice: once following a fatiguing condition involving the sustained performance of cognitively demanding tasks and once following a less demanding baseline condition.At baseline, activation was greater, primarily in PFC regions, in middle-aged compared to young adults. This suggests increased exertion of top-down cognitive control in middle-aged adults during successful encoding. In the fatigue condition, activation differences between the two age groups were no longer apparent. Activation in both age groups, but particularly the middle-aged group, decreased in comparison to baseline activation. Therefore, in a state of induced fatigue, middle-aged adults no longer showed greater exertion of cognitive control than young adults, and instead showed activation changes suggestive of an exhaustion of cognitive resources

Age differences in brain activation associated with verbal learning and fatigue

Learning abilities have already started to decline in middle age3. However, middle-aged adults are commonly required to continue to maintain performance in fulltime employment. We investigated whether the ability of middle-aged adults to maintain performance despite the effects of cognitive aging comes at the cost of increased cognitive fatigue. Functional MRI studies in patients with disorders characterised by fatigue, such as Multiple Sclerosis3 and Chronic Fatigue Syndrome4, have shown that, although patients could maintain task performance comparable to healthy participants, their performance was associated with increased and more dispersed brain activation. This finding has been attributed to the exertion of greater cognitive effort by patients which, consequentially, has been suggested to underlie their experience of increased cognitive fatigue. Behavioural studies have shown that cognitive fatigue symptoms can be induced in healthy participants by the prolonged performance of cognitively demanding tasks5. In the present study we used fMRI to examine verbal learning related brain activation in young and middle- aged adults following a control intervention and following a fatigue inducing intervention. Conclusions: 1. Middle-aged maintained comparable verbal learning performance to young, and did not indicate greater feelings of subjective fatigue. 2. Middle-aged showed greater activation than young in areas associated with cognitive control and attentional effort following the fatigue intervention during encoding, but not during recognition. 3. Greater subjective fatigue was associated with decreased activation in the left DLPFC in both age groups during encoding, but in young participants only during recognition. 4. It is suggested that middle-aged responded to the increased demands of verbal recognition by switching to more automatic processing

Jogos eletrônicos: uma análise sobre as percepções de alunos e professores do Colégio de Aplicação

Os jogos eletrônicos estão cada vez mais comuns devido à popularização da internet nos últimos anos e vêm gerando diversas dúvidas sobre as suas aproximações com os temas violência, educação e lazer. Esta é uma pesquisa que teve como objetivo principal analisar as percepções de alunos e professores de uma escola de ensino básico e perceber os diferentes modos de interpretação de questões sobre jogos eletrônicos. Para atingir os objetivos propostos, foi realizado um questionário virtual distribuído para os alunos de francês do oitavo ano do Colégio de Aplicação da UFRGS (n=16) e para os professores do Projeto Pixel, etapa referente ao 8º e 9º anos escolares. Os resultados obtidos com a pesquisa indicaram que as diferenças entre as percepções de alunos e professores foram poucas. Verificou-se que os jogos eletrônicos estão cada vez sendo mais presentes e bem aceitos, inclusive por professores, podendo ser considerados instrumentos de educação

‘Born to Shop’: Malls, Dream-Worlds and Capitalism

It has been twenty years since the fall of the Berlin Wall, and a new generation, untouched by the previous communist regimes, has come to adulthood throughout the post-communist world. The Iulius Group’s logo – ‘Born to shop!’ – suggests that these are born shoppers: the capitalist babies of Central and Eastern Europe who are sustaining the largest growth in retail and shopping malls in Europe. With no living memory of shortages, queuing, or government restrictions, they know only the limit of their own – or their parents’ – pocket/credit. Their world could not be more different from the one that their parents and grandparents experienced: both the abundance of goods and services, as well as the opulent settings under which they are now sold, offer striking visual contrasts to the not-so-distant past. In addition, the very experience of consumption is directly connected to the way in which the current social fabric – and new social divisions within it – is interwoven with the physical and architectural changes taking place in the urban setting

Comparison of magnetic resonance with computed tomography angiography for preoperative localization of the Adamkiewicz artery in thoracoabdominal aortic aneurysm patients

ObjectivePreoperative localization of the Adamkiewicz artery and its segmental supplier in advance of thoracic aortic aneurysm (TAA) and thoracoabdominal aortic aneurysm (TAAA) repair is proposed to be useful to prevent postoperative paraplegia. The diagnostic potential of magnetic resonance angiography (MRA) and computed tomography angiography (CTA) was evaluated for the preoperative localization of the Adamkiewicz artery in white TAAA patients.MethodsThirty-nine consecutive patients with a TAA(A) scheduled for elective open surgical aortic repair preoperatively underwent MRA and CTA. Objective image quality was assessed by measuring the signal-to-noise ratio and contrast-to-noise ratio of the Adamkiewicz artery and was related to patient thickness. Two independent observers scored the location of the Adamkiewicz artery and the subjective image quality of vessel-background contrast of the Adamkiewicz artery, image noise, spinal cord tissue enhancement, epidural venous enhancement, and overall image quality.ResultsAverage detection rate for Adamkiewicz artery localization was 71% (67% to 74%) for CTA and 97% (94% to 100%) for MRA. Interobserver agreement was 82% for CTA and 94% for MRA. Signal-to-noise ratio was significantly higher (P < .001) and contrast-to-noise ratio was significantly (P < .001) lower for CTA than for MRA. Contrast of the Adamkiewicz artery (P < .001) and overall image quality (P < .004) were judged to be significantly better for MRA. Spinal cord tissue enhancement was judged stronger at CTA (P < .03), with significantly less epidural venous enhancement (P < .001). No significant difference was found in image noise. Signal-to-noise and contrast-to-noise decreased significantly (P < .001) with increasing patient thickness for CTA but not for MRA.ConclusionsLocalization of the Adamkiewicz artery in white TAAA patients is possible with both CTA and MRA. Compared with CTA, MRA is more favorable because of the higher Adamkiewicz artery detection rate, the higher contrast-to-noise ratio, and its independence of patient thickness

Sexual behaviour and less frequent bathing are associated with higher human papillomavirus incidence in a cohort study of uncircumcised Kenyan men

Objectives—Data on the acquisition of human papillomavirus (HPV) infection in men are limited, especially from developing regions including Africa. The objective of this study was to characterise and determine the risk factors of HPV acquisition among a cohort of uncircumcised men participating in a randomised controlled trial (RCT) of male circumcision in Kisumu, Kenya. Methods—Penile exfoliated cell specimens were collected at baseline, 6- and 12-month followup visits from the glans/coronal sulcus and shaft of men enrolled in the control arm of the RCT between 2002 and 2005. All participants were HIV seronegative, aged 17–24 years at baseline and remained uncircumcised over follow-up. Specimens were tested with GP5+/6+ PCR to detect 44 HPV types. Parametric frailty models were used to assess risk factors of HPV incidence. Results—The median age of 966 participants was 20 years. The median follow-up time was 12.1 months. The incidence rate (IR) of any HPV infection was 49.3/1000 person-months with HPV16 having the highest IR (10.9/1000 person-months). The strongest risk factors for overall HPV incidence were bathing less frequently than daily (adjusted HR=2.6; 95% CI 1.0 to 6.5) and having ≥2 female sexual partners in the past year (adjusted HR=1.6; 95% CI 1.2 to 2.1). Conclusions—HPV IRs were notably high in this cohort of high-risk, uncircumcised men from Kisumu, Kenya, with the number of sexual partners and bathing frequency being the strongest risk factors