Limits on the validity of infinite length assumptions for modelling shallow landslides

The infinite slope method is widely used as the geotechnical component of geomorphic and landscape evolution models. Its assumption that shallow landslides are infinitely long (in a downslope direction) is usually considered valid for natural landslides on the basis that they are generally long relative to their depth. However, this is rarely justified, because the critical length/depth (L/H) ratio below which edge effects become important is unknown. We establish this critical L/H ratio by benchmarking infinite slope stability predictions against finite element predictions for a set of synthetic two-dimensional slopes, assuming that the difference between the predictions is due to error in the infinite slope method. We test the infinite slope method for six different L/H ratios to find the critical ratio at which its predictions fall within 5% of those from the finite element method. We repeat these tests for 5000 synthetic slopes with a range of failure plane depths, pore water pressures, friction angles, soil cohesions, soil unit weights and slope angles characteristic of natural slopes. We find that: (1) infinite slope stability predictions are consistently too conservative for small L/H ratios; (2) the predictions always converge to within 5% of the finite element benchmarks by a L/H ratio of 25 (i.e. the infinite slope assumption is reasonable for landslides 25 times longer than they are deep); but (3) they can converge at much lower ratios depending on slope properties, particularly for low cohesion soils. The implication for catchment scale stability models is that the infinite length assumption is reasonable if their grid resolution is coarse (e.g. >25?m). However, it may also be valid even at much finer grid resolutions (e.g. 1?m), because spatial organization in the predicted pore water pressure field reduces the probability of short landslides and minimizes the risk that predicted landslides will have L/H ratios less than 25. Copyright (c) 2012 John Wiley & Sons, Ltd.

Homeostasis limits the development of mature CD8+ but not CD4+ thymocytes.

The involvement of a variety of clonal selection processes during the development of T lymphocytes in the thymus has been well established. Less information, however, is available on how homeostatic mechanisms may regulate the generation and maturation of thymocytes. To investigate this question, mixed radiation bone marrow chimeras were established in which wild-type T cell precursors capable of full maturation were diluted with precursors deficient in maturation potential because of targeted mutations of the RAG1 or TCR-alpha genes. In chimeras in which the majority of thymocytes are blocked at the CD4- CD8- CD25+ stage (RAG1 deficient), and only a small proportion of T cell precursors are of wild-type origin, we observed no difference in the maturation of wild-type CD4- CD8- CD25+ cells to the CD4+ CD8+ stage as compared with control chimeras. Therefore, the number of cell divisions occurring during this transition is fixed and not subject to homeostatic regulation. In contrast, in mixed chimeras in which the majority of thymocytes are blocked at the CD4+ CD8+ stage (TCR-alpha deficient), an increased efficiency of development of wild-type mature CD8+ cells was observed. Surprisingly, the rate of generation of mature CD4+ thymocytes was not affected in these chimeras. Thus, the number of selectable CD8 lineage thymocytes apparently saturates the selection mechanism in normal mice while the development of CD4 lineage cells seems to be limited only by the expression of a suitable TCR. These data may open the way to the identification of homeostatic mechanisms regulating thymic output and CD4/CD8 lineage commitment, and the development of means to modulate it.

A Dethroned King? The Limits of State Infrastructural Power in France

Since the 1980s in Western Europe, centralized states' control over subnational territories has been deeply affected by processes of Europeanization and regionalization. These changes have raised the issue of state territorial restructuring in a particular fashion: what capacity have formerly centralized states retained to steer and control subnational territories? The article draws on Mann's concept of infrastructural power, which refers to the state's capacity to exercise control and implement political decisions over the national territory. The article applies the two main operationalizations of the concept, namely the capability of the state to exercise control and the weight of the state in the subnational territories. Empirically, the article focuses on the French state in two policy sectors (education and housing). Although France is a most likely case, this article challenges this expectation, and shows the limits of the French state's infrastructural power over the subnational territories since the late 1980s.

Does Health Information Matter for Modifying Consumption?, October 2006

A field experiment was conducted in France to evaluate the impact of health information on fish consumption. A warning given to the treatment group revealed the risks of methylmercury contamination in fish and also gave consumption recommendations. Using difference-indifferences estimation, we show that this warning led to a significant but relatively weak decrease in fish consumption. However, consumption of the most contaminated fish did not decrease despite advice to avoid consumption of these types of fish. Accompanying questionnaires show that consumers imperfectly memorize the fish species quoted in the warning. The results point to the relatively poor efficacy of a complex health message, despite its use by health agencies around the world.

Limits and possibilities experienced by nurses in the treatment of women with chronic venous ulcers

Objective To understand the experiences and expectations of nurses in the treatment of women with chronic venous ulcers. Method Phenomenological research was based on Alfred Schütz, whose statements were obtained in January, 2012, through semi-structured interviews with seven nurses. Results The nurse reveals the difficulties presented by the woman in performing self-care, the perceived limitations in the treatment anchored in motivation, and the values and beliefs of women. It showed professional frustration because venous leg ulcer recurrence, lack of inputs, interdisciplinary work and training of nursing staff. There was an expected adherence to the treatment of women, and it emphasized the need for ongoing care, supported self-care and standard practices in treatment. Conclusion That treatment of chronic venous leg ulcers constitutes a challenge that requires collective investment, involving women, professionals, managers and health institutions.

COMPETENCY-BASED TRAINING IN NURSING: LIMITS AND POSSIBILITIES

Objective To analyze the possibilities and limits of competency-based training in nursing. Method An integrative review of the literature on the subject was carried out, and an analysis was made of the results of a survey evaluating a nursing course based on areas of competency. A dialog was then established between the review and the results of the research. Results On the question of which theoretical type of competency the articles from the literature relate to, there is a predominance of the constructivist perspective, followed by the functionalist approach and the dialog-based approach. In the dialog between the literature and the research, limits and possibilities were observed in the development of a training by areas of competency. Conclusion The dialog-based approach to competency is the proposition that most approximates to the profile defined by the National Curriculum Guidelines for training in nursing, and this was also identified in the evaluation survey that was studied. However, it is found that there are aspects on better work is needed, such as: partnership between school and the workplace, the role of the teacher, the role of the student, and the process of evaluation.

Cellular distribution of glucose and monocarboxylate transporters in human brain white matter and multiple sclerosis lesions.

To ensure efficient energy supply to the high demanding brain, nutrients are transported into brain cells via specific glucose (GLUT) and monocarboxylate transporters (MCT). Mitochondrial dysfunction and altered glucose metabolism are thought to play an important role in the progression of neurodegenerative diseases, including multiple sclerosis (MS). Here, we investigated the cellular localization of key GLUT and MCT proteins in human brain tissue of non-neurological controls and MS patients. We show that in control brain tissue GLUT and MCT proteins were abundantly expressed in a variety of central nervous system cells, particularly in microglia and endothelial cells. In active MS lesions, GLUTs and MCTs were highly expressed in infiltrating leukocytes and reactive astrocytes. Astrocytes manifest increased MCT1 staining and maintain GLUT expression in inactive lesions, whereas demyelinated axons exhibit significantly reduced GLUT3 and MCT2 immunoreactivity in inactive lesions. Finally, we demonstrated that the co-transcription factor peroxisome proliferator-activated receptor gamma co-activator 1-alpha (PGC-1α), an important protein involved in energy metabolism, is highly expressed in reactive astrocytes in active MS lesions. Overexpression of PGC-1α in astrocyte-like cells resulted in increased production of several GLUT and MCT proteins. In conclusion, we provide for the first time a comprehensive overview of key nutrient transporters in white matter brain samples. Moreover, our data demonstrate an altered expression of these nutrient transporters in MS brain tissue, including a marked reduction of axonal GLUT3 and MCT2 expression in chronic lesions, which may impede efficient nutrient supply to the hypoxic demyelinated axons thereby contributing to the ongoing neurodegeneration in MS. GLIA 2014;62:1125-1141.

Physical activity modulates heat shock protein-72 expression and limits oxidative damage accumulation in a healthy elderly population aged 60 90 years

BACKGROUND: Reactive oxygen species production increases during aging, whereas protective mechanisms such as heat shock proteins (HSPs) or antioxidant capacity are depressed. Physical activity has been hypothesized to provide protection against oxidative damage during aging, but results remain controversial. This study aimed to investigate the effect of different levels of physical activity during aging on Hsp72 expression and systemic oxidative stress at rest and in response to maximal exercise. METHODS: Plasma antioxidant capacity (Trolox equivalent antioxidant capacity, TEAC), thiobarbituric acid-reactive species (TBARS), advanced oxidized proteins products (AOPP), and Hsp72 expression in leukocytes were measured before and after maximal exercise testing in 32 elderly persons (aged 73.2 years), who were assigned to two different groups depending on their level of physical activity during the past 12 months (OLow = moderate to low level; OHigh = higher level). RESULTS: The OHigh group showed higher aerobic fitness and TEAC (both representing 120% of OLow values) as well as lower oxidative damage (50% of OLow values) and Hsp72 expression. Exercise led to a lower increase in oxidative damage in the OHigh group. Aerobic fitness was positively correlated with TEAC and negatively with lipid peroxidation (TBARS). Hsp72 expression was negatively correlated with TEAC but positively correlated with TBARS levels. CONCLUSIONS: The key finding of this study is that, in people aged 60 to 90 years, long-term high level of physical activity preserved antioxidant capacity and limited oxidative damage accumulation. It also downregulated Hsp72 expression, an adaptation potentially resulting from lower levels of oxidative damage.

First impressions matter: Signalling as a source of policy dynamics

We first establish that policymakers on the Bank of England's Monetary PolicyCommittee choose lower interest rates with experience. We then reject increasingconfidence in private information or learning about the structure of the macroeconomy as explanations for this shift. Instead, a model in which voters signal theirhawkishness to observers better fits the data. The motivation for signalling is consistent with wanting to control inflation expectations, but not career concerns orpleasing colleagues. There is also no evidence of capture by industry. The papersuggests that policy-motivated reputation building may be important for explainingdynamics in experts' policy choices.

Do institutions and culture matter for business cycles?

We examine the relationship between institutions, culture and cyclical fluctuations for a sampleof 45 European, Middle Eastern and North African countries. Better governance is associated withshorter and less severe contractions and milder expansions. Certain cultural traits, such as lack ofacceptance of power distance and individualism, are also linked business cycle features. Businesscycle synchronization is tightly related to similarities in the institutional environment. Mediterraneancountries conform to these general tendencies.

Individual Classification of Mild Cognitive Impairment Subtypes by Support Vector Machine Analysis of White Matter DTI.

BACKGROUND AND PURPOSE: MCI was recently subdivided into sd-aMCI, sd-fMCI, and md-aMCI. The current investigation aimed to discriminate between MCI subtypes by using DTI. MATERIALS AND METHODS: Sixty-six prospective participants were included: 18 with sd-aMCI, 13 with sd-fMCI, and 35 with md-aMCI. Statistics included group comparisons using TBSS and individual classification using SVMs. RESULTS: The group-level analysis revealed a decrease in FA in md-aMCI versus sd-aMCI in an extensive bilateral, right-dominant network, and a more pronounced reduction of FA in md-aMCI compared with sd-fMCI in right inferior fronto-occipital fasciculus and inferior longitudinal fasciculus. The comparison between sd-fMCI and sd-aMCI, as well as the analysis of the other diffusion parameters, yielded no significant group differences. The individual-level SVM analysis provided discrimination between the MCI subtypes with accuracies around 97%. The major limitation is the relatively small number of cases of MCI. CONCLUSIONS: Our data show that, at the group level, the md-aMCI subgroup has the most pronounced damage in white matter integrity. Individually, SVM analysis of white matter FA provided highly accurate classification of MCI subtypes.

The male of Mischocyttarus nomurae Richards, with a re-examination of the limits and contents of the M. cerberus species group (Hymenoptera, Vespidae, Polistinae, Mischocyttarini)

The male of Mischocyttarus nomurae Richards, 1978 is described for the first time, and relationships between this and other similar species are discussed in a context of redefining the limits of the M. cerberus species group.

Combined analysis of grey matter voxel-based morphometry and white matter tract-based spatial statistics in late-life bipolar disorder.

Background: Previous magnetic resonance imaging (MRI) studies in young patients with bipolar disorder indicated the presence of grey matter concentration changes as well as microstructural alterations in white matter in various neocortical areas and the corpus callosum. Whether these structural changes are also present in elderly patients with bipolar disorder with long-lasting clinical evolution remains unclear. Methods: We performed a prospective MRI study of consecutive elderly, euthymic patients with bipolar disorder and healthy, elderly controls. We conducted a voxel-based morphometry (VBM) analysis and a tract-based spatial statistics (TBSS) analysis to assess fractional anisotropy and longitudinal, radial and mean diffusivity derived by diffusion tensor imaging (DTI). Results: We included 19 patients with bipolar disorder and 47 controls in our study. Fractional anisotropy was the most sensitive DTI marker and decreased significantly in the ventral part of the corpus callosum in patients with bipolar disorder. Longitudinal, radial and mean diffusivity showed no significant between-group differences. Grey matter concentration was reduced in patients with bipolar disorder in the right anterior insula, head of the caudate nucleus, nucleus accumbens, ventral putamen and frontal orbital cortex. Conversely, there was no grey matter concentration or fractional anisotropy increase in any brain region in patients with bipolar disorder compared with controls. Limitations: The major limitation of our study is the small number of patients with bipolar disorder. Conclusion: Our data document the concomitant presence of grey matter concentration decreases in the anterior limbic areas and the reduced fibre tract coherence in the corpus callosum of elderly patients with long-lasting bipolar disorder.

Beyond the glass ceiling: Does gender matter?

The representation of women in top corporate officer positions is steadily increasing. However, little is known about the impact this will have. A large literature documents that women are different from men in their choices and in their preferences, but most of this literature relies on samples of college students or workers at lower levels in the corporate hierarchy. If women must be like men to break the glass ceiling, we might expect gender differences to disappear among top executives. In contrast, using a large survey of all directors of publicly-traded corporations in Sweden, we show that female and male directors differ systematically in their core values and risk attitudes. While certain population gender differences disappear at the director level, others do not. Consistent with the findings for the Swedish population, female directors are more benevolent and universally concerned, but less power-oriented than men. However, they are less traditional and security-oriented than their male counterparts. Furthermore, female directors are slightly more risk-loving than male directors. This suggests that having a women on the board need not lead to more risk-averse decision-making.