Utrecht University

About: Utrecht University is a education organization based out in Utrecht, Utrecht, Netherlands. It is known for research contribution in the topics: Population & Context (language use). The organization has 58176 authors who have published 139351 publications receiving 6214282 citations. The organization is also known as: UU & Universiteit Utrecht.

High-cost, high-capacity backbone for global brain communication

Abstract: Network studies of human brain structural connectivity have identified a specific set of brain regions that are both highly connected and highly central. Recent analyses have shown that these putative hub regions are mutually and densely interconnected, forming a “rich club” within the human brain. Here we show that the set of pathways linking rich club regions forms a central high-cost, high-capacity backbone for global brain communication. Diffusion tensor imaging (DTI) data of two sets of 40 healthy subjects were used to map structural brain networks. The contributions to network cost and communication capacity of global cortico-cortical connections were assessed through measures of their topology and spatial embedding. Rich club connections were found to be more costly than predicted by their density alone and accounted for 40% of the total communication cost. Furthermore, 69% of all minimally short paths between node pairs were found to travel through the rich club and a large proportion of these communication paths consisted of ordered sequences of edges (“path motifs”) that first fed into, then traversed, and finally exited the rich club, while passing through nodes of increasing and then decreasing degree. The prevalence of short paths that follow such ordered degree sequences suggests that neural communication might take advantage of strategies for dynamic routing of information between brain regions, with an important role for a highly central rich club. Taken together, our results show that rich club connections make an important contribution to interregional signal traffic, forming a central high-cost, high-capacity backbone for global brain communication.

Teacher Wellbeing: The Importance of Teacher–Student Relationships

Abstract: Many studies have examined the importance of teacher–student relationships for the development of children. Much less is known, however, about how these relationships impact the professional and personal lives of teachers. This review considers the importance of teacher–student relationships for the wellbeing of teachers starting from the Transactional Model of Stress and Coping of Lazarus (1991). Based on theories on interpersonal relationships, it is postulated that teachers have a basic need for relatedness with the students in their class. It is discussed that teachers internalize experiences with students in representational models of relationships that guide emotional responses in daily interactions with students and change teacher wellbeing in the long run. In addition, the notion of mental representations of relationships at different levels of generalization could offer a window to understand how individual teacher–student relationships may affect the professional and personal self-esteem of teachers. Lastly, it is argued that the influence of student misbehavior on teacher stress may be more fully understood from a relationship perspective. The review shows that few studies have directly tested these propositions and offers suggestions for future research.

A meta-analysis of pregnancy outcomes in women with polycystic ovary syndrome

Abstract: Polycystic ovary syndrome (PCOS) is a common reproductive disorder associated with many characteristic features, including hyperandrogenaemia, insulin resistance and obesity which may have significant implications for pregnancy outcomes and long-term health of the woman. This meta-analysis was conducted to evaluate the risk of pregnancy and neonatal complications in women with PCOS. Electronic databases were searched for the following MeSH headings: PCOS, hyperandrogenism, pregnancy outcome, pregnancy complications, diabetes mellitus, type II. A handsearch of human reproduction and fertility and sterility was also conducted. Studies in which pregnancy outcomes in women with PCOS were compared with controls were considered for inclusion in this meta-analysis. Fifteen of 525 identified studies were included, involving 720 women presenting with PCOS and 4505 controls. Women with PCOS demonstrated a significantly higher risk of developing gestational diabetes [odds ratio (OR) 2.94; 95% confidence interval (CI): 1.70-5.08], pregnancy-induced hypertension (OR 3.67; 95% CI: 1.98-6.81), pre-eclampsia (OR 3.47; 95% CI: 1.95-6.17) and preterm birth (OR 1.75; 95% CI: 1.16-2.62). Their babies had a significantly higher risk of admission to a neonatal intensive care unit (OR 2.31; 95% CI: 1.25-4.26) and a higher perinatal mortality (OR 3.07; 95% CI: 1.03-9.21), unrelated to multiple births. In conclusion, women with PCOS are at increased risk of pregnancy and neonatal complications. Pre-pregnancy, antenatal and intrapartum care should be aimed at reducing these risks.

Diffusion-Weighted Whole-Body Imaging with Background Body Signal Suppression (DWIBS)

Abstract: In applying diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) technique, DW-MR images are acquired during free breathing, which results in images with high signal-to-noise ratio using relatively thin image sections (4–5 mm). Image acquisition during free breathing is possible because bulk tissue motion, including respiratory motion, may be considered as types of coherent motion, which do not result in significant signal loss unlike intravoxel incoherent motion, which reflects random water motion at a cellular level. The concept of DWIBS allows handling of the acquired images as a volumetric dataset and it exploits both prolonged T2 relaxation time and impeded diffusion that the majority of solid lesions (both benign and malignant) exhibit as mechanisms for image contrast, which is used for clinical evaluation of diseases.

Induced resistance in plants and the role of pathogenesis-related proteins

Abstract: The nature of induced resistance Resistance, according to Agrios (1988) is the ability of an organism to exclude or overcome, completely or in some degree, the effect of a pathogen or other damaging factor Disease resistance in plants is manifested by limited symptoms, reflecting the inability of the pathogen to grow or multiply and spread, and often takes the form of a hypersensitive reaction (HR), in which the pathogen remains confined to necrotic lesions near the site of infection Induced resistance is the phenomenonthat a plant, once appropriately stimulated, exhibits an enhanced resistance upon 'challenge' inoculation with a pathogen Although induced resistance has been attracting attention recently (Ryals et al, 1994; Hammerschmidt and Kuc, 1995), the first systematic enquiry into induced resistance was made by Ross (1961a,b) He observed that the inducible resistance response to tobacco mosaic virus (TMV) in N gene-containing, hypersensitively reacting tobacco was not confined to the immediate vicinity of the resulting local necrotic lesions, but extended to other plant parts A ring of tissue around the developing lesions became fully refractory to subsequent infection (localized acquired resistance; Ross, 1961a), whereas challenge inoculation of distant tissues resulted in much smaller, and occasionally fewer, lesions (systemic acquired resistance (SAR); Ross, 1961b) than in non-induced plants Even leaves thatweremere initials at the time of the primary inoculation became induced, suggesting that as a result of the initial infection, a signal was generated, transported and propagated, that primed the plant to respond more effectively to subsequent infection (Bozarth and Ross, 1964) Treatments that influenced lesion size after primary infection had similar effects on lesions developing upon challenge inoculation (Ross, 1966), leading to the conclusion that the mechanisms responsible for resistance expression were the same under both conditions Only upon challenge inoculation, defense mechanisms appeared to be expressed earlier and to a greater extent (De Laat and Van Loon, 1983; Dean and Kuc, 1987)