59 research outputs found
A Study into the Effect of the Presence of Moisture at the Wheel/Rail Interface during Dew and Damp Conditions
Incidents involving low levels of adhesion between the wheel and rail are a recurrent issue in the rail
industry. The problem has been mitigated using friction modifiers and traction enhancers, but a significant
number of incidents still occur throughout the year. The following work looks at the environmental
conditions that surround periods of low adhesion in order to provide an insight into why low adhesion
events occur. Network Rail Autumn data, which provided details on the time and location of low adhesion
incidents, was compared against weather data on a national and then local scale. Low adhesion incidents
have often been attributed to contamination on the rail, such as organic leaf matter, but other incidents occur
when no contamination is visible. The time, date and location of incidents were linked to local weather data
to establish any specific weather conditions that could lead to these events. The effects of precipitation,
temperature and humidity on the rail were analysed in order to further the understanding of low adhesion
in the wheel-rail contact, which will lead to better methods of mitigating this problem
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Here and now: perceptions of Indian Ocean islanders on the climate change and migration nexus
Empirical studies exploring the links between climate change and migration are increasing. Often, perceptions are not fully explored from the people most affected by the climate change and migration nexus. This article contributes to filling this gap by eliciting and analyzing perceptions regarding climate change and migration from an understudied population labelled as being amongst those most immediately and directly affected by climate change: Indian Ocean islanders. Open-ended, semi-structured interviews were conducted in two case study communities in Maldives (Kaafu Guraidhoo with 17 interviews and Raa Dhuvafaaru with 18 interviews) and two case study communities in Lakshadweep, India (Kavaratti with 35 interviews and Minicoy with 26 interviews). The results present the intervieweesā perceptions of climatic variability and change that they experience; how they perceive the causes of these changes; and links to migration decisions. The interviews demonstrate that perceptions of climate change, of migration, and of the links or lack thereof between the two are centred on the intervieweesā own experiences, their own locations, and the immediate timeframe. External information and direction has limited influence. Their perceptions are framed as being the āhere and nowā through topophilia (here) and tempophilia (now). The islandersā views do not avoid, but rather encompass, long-term livelihoods and the future. Such a future might be in another location, but the anchor is expressing future hopes and aspirations through the here and now. It is not linked to the wide-scale, long-term issue of climate change
Transformation, adaptation and development: relating concepts to practice
In recent years there has been a growing number of academic reviews discussing the theme of transformation and its association with adaptation to climate change. On the one hand this has stimulated exchange of ideas and perspectives on the parameters of transformation, but it has also given rise to confusion in terms of identifying what constitutes a non-incremental form of adaptation on the ground. What this article aims to do instead is help researchers and practitioners relate different interpretations of transformation to practice by proposing a typological framework for categorising forms of change that focuses on mechanisms and objectives. It then discusses how these categorisations link to the broader conceptions and critiques noted above, with the idea that this will enable those who seek to analyse or plan adaptation to better analyse what types of action are potentially constitutive of transformation. In doing so, it should equally assist in the identification and specification of critical questions that need to be asked of such activity in relation to issues of sustainability and equity. As the term transformation gains ground in discussions of climate change adaptation, it is necessary to take a step back, review quite what commentators mean when they use the word, and consider the implications on people, especially the most vulnerable and marginalised, of ādoingā or promoting transformation in its different forms
Fasting Induces the Expression of PGC-1Ī± and ERR Isoforms in the Outer Stripe of the Outer Medulla (OSOM) of the Mouse Kidney
Peroxisome proliferator-activated receptor-Ī³ co-activator-1Ī± (PGC-1Ī±) is a member of the transcriptional coactivator family that plays a central role in the regulation of cellular energy metabolism under various physiological stimuli. During fasting, PGC-1Ī± is induced in the liver and together with estrogen-related receptor a and Ī³ (ERRĪ± and ERRĪ³, orphan nuclear receptors with no known endogenous ligand, regulate sets of genes that participate in the energy balance program. We found that PGC-1Ī±, ERRĪ± and ERRĪ³ was highly expressed in human kidney HK2 cells and that PGC-1Ī± induced dynamic protein interactions on the ERRĪ± chromatin. However, the effect of fasting on the expression of endogenous PGC-1Ī±, ERRĪ± and ERRĪ³ in the kidney is not known.In this study, we demonstrated by qPCR that the expression of PGC-1Ī±, ERRĪ± and ERRĪ³ was increased in the mouse kidney after fasting. By using immunohistochemistry (IHC), we showed these three proteins are co-localized in the outer stripe of the outer medulla (OSOM) of the mouse kidney. We were able to collect this region from the kidney using the Laser Capture Microdissection (LCM) technique. The qPCR data showed significant increase of PGC-1Ī±, ERRĪ± and ERRĪ³ mRNA in the LCM samples after fasting for 24 hours. Furthermore, the known ERRĪ± target genes, mitochondrial oxidative phosphorylation gene COX8H and the tricarboxylic acid (TCA) cycle gene IDH3A also showed an increase. Taken together, our data suggest that fasting activates the energy balance program in the OSOM of the kidney
Chronic and structural poverty in South Africa: Challenges for action and research
Ten years after liberation, the persistence of poverty is one of the most important and urgent problems facing South Africa. This paper reflects on some of the findings based on research undertaken as part of the participation of the Programme for Land and Agrarian Studies (PLAAS) at the University of the Western Cape in the work of the Chronic Poverty Research Centre (CPRC), situates it within the broader literature on poverty in South Africa, and considers some emergent challenges. Although PLAASās survey, being only the first wave of a panel study, does not yet cast light on short term poverty dynamics, it illuminates key aspects of the structural conditions that underpin long-term poverty: the close interactions between asset poverty, employment-vulnerability and subjection to unequal social power relations. Coming to grips with these dynamics requires going beyond the limitations of conventional āsustainable livelihoodsā analyses; and functionalist analyses of South African labour markets. The paper argues for a re-engagement with the traditions of critical sociology, anthropology and the theoretical conventions that allow a closer exploration of the political economy of chronic poverty at micro and macro level
Determining Critical Soil pH for Sunflower Production
Soil acidity has become a major yield-limiting factor in cropping systems of the Southern Great Plains, in which winter wheat (Triticum aestivum L.) is the predominant crop. Sunflower (Helianthus annuus L.) is a strong rotational crop with winter wheat due to its draught and heat tolerance. However, the effects of low soil pH on sunflower productivity have not been explored. The objective of this study was to determine the critical soil pH and aluminum concentration (AlKCl) for sunflower. Sunflower was grown in a randomized complete block design with three replications of a pH gradient ranging from 4.0 to 7.0 at three locations with varying soil types. Soil pH was altered using aluminum sulfate (Al2(SO4)3) and hydrated lime (Ca(OH)2). Plant height, vigor, and survivability were all negatively affected by soil acidity. Sunflower yield was reduced by 10% at or below soil pH 4.7 to 5.3 dependent upon location and soil type. Levels of AlKCl above 6.35āmgākgā1 reduced seed yield by 10% or greater. We concluded that sunflower may serve as a better rotational crop with winter wheat under acidic conditions when compared to other adaptable crops
Abnormal strategies during visual discrimination reversal learning in ephrin-A2-/-mice
Eph receptors and ephrins are involved in establishing topographic connectivity in primary sensory brain regions, but also in higher order structures including the cortex and hippocampus. Ephrin-A2 12/ 12 mice have abnormal topography in the primary visual system but have normal visual and learning performance on a simple visual discrimination task. Here we use signal detection theory to analyse learning behaviour of these mice. Wild-type (WT) and ephrin-A2 12/ 12 (KO) mice performed equally well in a two-stimulus visual discrimination task, with similar learning rates and response latencies. However, during reversal learning, when the rewarded stimulus was switched, the two genotypes exhibited differences in response strategies: while WTs favoured a win-stay strategy, KOs remained relatively neutral. KOs also exhibited a stronger lateralization bias in the initial stages of learning, choosing the same arm of the maze with high probability. In addition, use of a Bayesian \u201coptimal observer\u201d revealed that compared to WT, KO mice adapted their decisions less rapidly to a change in stimulus-reward relationship. We suggest that the misexpression of ephrin-A2 may lead to abnormal connectivity in regions known for their involvement in reversal learning and perseverative behaviours, including thalamic\u2013prefrontal cortical\u2013striatal circuitry and particularly orbitofrontal cortex. The implication is that topographic organisation of higher order brain regions may play an important role in learning and decision making.Peer reviewed: YesNRC publication: Ye
Facial Dystonia with Facial Grimacing and Vertical Gaze Palsy with āRound the Housesā Sign in a 29-Year-Old Woman
<p>A 29-year-old woman developed progressive dysarthria and coordination problems from the age of 15. Examination showed dysarthria, facial dystonia, bibrachial dystonia, hyperreflexia, ataxia, and emotional incontinence. Downward supranuclear gaze palsy was prominent with a āRound the Housesā sign. Magnetic resonance imaging of the brain and medulla, electroneurography, and cerebrospinal fluid were normal. A computed tomography scan showed hepatosplenomegaly. This combination of progressive neurological symptoms together with hepatosplenomegaly was suggestive of inborn error of metabolism. A bone marrow biopsy showed an increased number of macrophages with foamy content, highly suggestive of lysosomal disease. Plasmatic chitotriosidase activity and CCL18 were increased. Genetic testing showed heterozygosis for the variation c.1070CāT (p.Ser357Leu) and c.1843āT (Arg615Cys), confirming the diagnosis of Niemann-Pick type C (NPC). The āRound the Housesā sign has only been described in patients with progressive supranuclear palsy (PSP). This sign is described as an inability to produce pure vertical saccades along the midline and instead moving the eyes in a lateral arc to accomplish the movement. The observation of this sign in a patient with NPC indicates that this bedside finding is not specific for PSP, but a sign of medial longitudinal fasciculus dysfunction. The presence of facial dystonia with facial grimacing together with supranuclear gaze palsy is highly characteristic and useful for the diagnosis of NPC. NPC is an important underdiagnosed condition, given the availability of treatment and a mean diagnostic delay of 6 years.</p
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