23 research outputs found

    Synthesis effects on the magnetic and superconducting properties of RuSr2GdCu2O8

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    A systematic study on the synthesis of the Ru-1212 compound by preparing a series of samples that were annealed at increasing temperatures and then quenched has been performed. It results that the optimal temperature for the annealing lies around 1060-1065 C; a further temperature increase worsens the phase formation. Structural order is very important and the subsequent grinding and annealing improves it. Even if from the structural point of view the samples appear substantially similar, the physical characterization highlight great differences both in the electrical and magnetic properties related to intrinsic properties of the phase as well as to the connection between the grains as inferred from the resistive and the Curie Weiss behaviour at high temperature as well as in the visibility of ZFC anf FC magnetic signals.Comment: 17 pages, 12 figures. Proc. Int. Workshop " Ruthenate and rutheno-cuprate materials: theory and experiments", Vietri, October 2001. To be published on LNP Series, Springer Verlag, Berlin, C. Noce, A. Vecchione, M. Cuoco, A. Romano Eds, 200

    Youth representations of environmental protest

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    A necessary condition for a functioning democracy is the participation of its citizens, including its youth. This is particularly true for political participation in environmental decisions because these decisions can have intergenerational consequences. In this article we examine young people’s beliefs about one form of political participation - protest - in the context of communities affected by fracking and associated anti-fracking protest, and discuss the implications of these representations for education. Drawing on focus groups with 121 young people (age 15-19) in 5 schools and colleges near sites which have experienced anti-fracking protest in England and Northern Ireland, we find young people well-informed about avenues for formal and non-formal political participation against a background of disillusionment with formal political processes and varying levels of support for protest. We find representations of protest as disruptive, divisive, extreme, less desirable than other forms of participation, and ineffective in bringing about change but effective in awareness-raising. These representations are challenging, not least because the way protest is interpreted is critical to the way people think and act in the world. These representations of environmental protest must be challenged through formal education in order to safeguard the UN Convention on the Rights of the Child and ensure that the spirit of Article 11 of the UK Human Rights Act is protected

    Genetic analyses of diverse populations improves discovery for complex traits

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    Genome-wide association studies (GWAS) have laid the foundation for investigations into the biology of complex traits, drug development and clinical guidelines. However, the majority of discovery efforts are based on data from populations of European ancestry1–3. In light of the differential genetic architecture that is known to exist between populations, bias in representation can exacerbate existing disease and healthcare disparities. Critical variants may be missed if they have a low frequency or are completely absent in European populations, especially as the field shifts its attention towards rare variants, which are more likely to be population-specific4–10. Additionally, effect sizes and their derived risk prediction scores derived in one population may not accurately extrapolate to other populations11,12. Here we demonstrate the value of diverse, multi-ethnic participants in large-scale genomic studies. The Population Architecture using Genomics and Epidemiology (PAGE) study conducted a GWAS of 26 clinical and behavioural phenotypes in 49,839 non-European individuals. Using strategies tailored for analysis of multi-ethnic and admixed populations, we describe a framework for analysing diverse populations, identify 27 novel loci and 38 secondary signals at known loci, as well as replicate 1,444 GWAS catalogue associations across these traits. Our data show evidence of effect-size heterogeneity across ancestries for published GWAS associations, substantial benefits for fine-mapping using diverse cohorts and insights into clinical implications. In the United States—where minority populations have a disproportionately higher burden of chronic conditions13—the lack of representation of diverse populations in genetic research will result in inequitable access to precision medicine for those with the highest burden of disease. We strongly advocate for continued, large genome-wide efforts in diverse populations to maximize genetic discovery and reduce health disparities. © 2019, The Author(s), under exclusive licence to Springer Nature Limited

    Genetic and clinical characteristics of patients with HNF1A gene variations from the German-Austrian DPV database

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    OBJECTIVE: To determine prevalence, genetic and phenotype characteristics of patients with hepatocyte nuclear factor-1alpha (HNF1A) variants in the Diabetes Patienten Verlaufsdokumenation (DPV) multicentre database and to examine the influence of HNF1A mutation type, or location on clinical phenotypes. PATIENTS AND METHODS: Seventy-one DPV patients were labelled as HNF1A-MODY (MODY3). Forty-four patients carried HNF1A mutations, while 27 patients were found to have HNF1A polymorphisms only. Associations between mutation type/position and age at disease onset, HbAlc, body mass index (BMI), diagnosis, family history and treatment modality were analysed using non-parametric statistics (Wilcoxon test). RESULTS: Patients with HNF1A mutations were 36% male, aged 14.1+/-5.8 years at diagnosis, and slightly overweight (BMI-SDS: +0.8+/-1.1). Treatment was lifestyle intervention (20.5%), insulin (35.3%), oral anti-diabetic (OAD, 43%) and both insulin+OAD (15.9%). More patients with missense mutations (60%) than patients with nonsense mutations/frameshift (23.8%) did not use insulin (P=0.03). No differences were found with regard to mutation types, isoform or domain. We identified several previously undescribed mutations in the cohort including c.-158insGGGTTGG in the promoter region, G31X, E41X, Q130X, L162P, R245I, A269P, S355X, Q398X, Q473X, Q495X, E508X, P588fs-insGCCA and P588fs-delAC. Patients carrying HNF1A polymorphisms were significantly younger at diagnosis than patients with HNF1A mutations (10.9+/-4.2 vs 14.19+/-5.8 years; P=0.027), and all carried I27L, S487N and A98V (n=3). CONCLUSION: HNF1A-MODY is the second most frequent MODY diagnosis registered in the DPV database, and previously undescribed HNF1A mutations account for about one-third of HNF1A-MODY cases. Patients with HNF1A polymorphisms documented as HNF1A-MODY were misclassified. They may have autoantibody-negative type 1B or type 2 diabetes or may have other MODY types

    Tracking of metabolic control from childhood to young adulthood in type 1 diabetes

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    Objective: This prospective longitudinal survey was designed to follow patients with diabetes from disease onset in childhood over an extended period of time including puberty until young adulthood with respect to metabolic control. Study design: An electronic diabetes patient documentation system used in diabetes centers in Austria and Germany was utilized for standardized data collection. Complete documentation of metabolic control for prepuberty (=13 years), puberty (14-19 years), and adulthood (=20 years) was available in 1146 patients. Results: Median age at diabetes manifestation was 7.2 (IQR 4.7-9.4) years; 49% were male. In the prepubertal stage, median glycated hemoglobin A1c (HbA1c) was 7.5 (IQR 6.8-8.3), during puberty 8.0 (IQR 7.3-8.9), and after puberty 7.8 (IQR 7.1-9.0). A significant intra-individual correlation was found for prepuberty to puberty HbA1c levels (R = 0.55, P < .001), puberty to adulthood (R = 0.59, P < .001), as well as prepuberty to adulthood (R = 0.30, P < .001). When patients were divided into tertiles of prepubertal HbA1c, HbA1c increased in all 3 groups over time, however, significant group differences tracked into adulthood (P < .001 at all stages). A regression model identified pre-pubertal HbA1c as a significant and relevant predictor of metabolic control in young adulthood adjusted for confounders (P < .001). Conclusions: This survey provides evidence for long-term tracking of metabolic control from childhood until adulthood, suggesting an early focus on metabolic control

    Visual-Vestibular interaction in motion perception.

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    Correct perception of self motion is of vital importance for both the control of our position and posture when moving around in our environment. With the development of human controlled vehicles as bicycles, cars and aircraft motion perception became of interest for the understanding of vehicle control. For flight simulation the understanding of motion perception became even more important where the motion stimulation of the simulator pilot is influenced by the limitations of the ground based simulation process. Motion perception as performed by the central nervous system, CNS, is based on sensory inputs from the visual, vestibular and somatosensory system. These sensory systems provide the information about body orientation and self motion. Due to the different dynamic characteristics of the sensors smart processing of the sensory information is required to perceive spatial orientation and motion over a wide range of conditions. The paper describes how in the perception process flow and attitude information from the visual system, linear and rotational motion information from the vestibular system, and body orientation from the somatosensory system is combined in the motion perception process. Based on available knowledge motion perception models were developed and an overview of these models will be presented. Three perception models will be discussed to explain how the visual and vestibular systems contribute to the percept of motion. The limitations of ground based motion simulation affects pilot's motion perception in flight simulation. Differences between the output of the perception model stimulated with the visual and vestibular motion cues in the real aircraft and in the simulated aircraft will be presented for a representative aircraft maneuver. © 2011 by R.J.A.W. Hosman. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission

    Bartonella Endocarditis A Pathology Shared by Animal Reservoirs and Patients

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    National audienceBartonellae were first recognized to cause endocarditis in humans in 1993 when cases caused by Bartonella quintana, B. elizabethae, and B. henselae were reported. Since the first isolation of Bartonella vinsonii subspecies berkhoffii from a dog with endocarditis, this organism has emerged as an important pathogen in dogs and an emerging pathogen in people. Subsequently, four types of B. vinsonii subsp. berkhoffii have been described, all of which have been associated with endocarditis in dogs. A limited number of dog endocarditis cases have also been associated with B. clarridgeiae, B. washoensis, B. quintana, and B. rochalimae. The second canine B. clarridgeiae endocarditis case is presented. The clinical and pathological characteristics of Bartonella endocarditis in dogs are similar to disease observed in humans, more often affecting the aortic valve, presenting with highly vegetative lesions with accompanying calcification, and in most instances high antibody titers. Pathological features in dogs include a combination of fibrosis, mineralization, endothelial proliferation, and neovascularization with variable inflammation. Endocarditis has also been described in animal species, which are the natural reservoir of specific Bartonella species, once thought to be solely healthy carriers of these pathogens. A few Bartonella endocarditis cases, including B. henselae, have been reported in cats in the USA and Australia. The second case of B. henselae type Houston I identified in the USA is presented. Furthermore, two cases of B. bovis endocarditis were recently described in adult cows from France. Finally, on-going investigation of valvular endocarditis in free-ranging Alaskan sea otters suggests the involvement of Bartonella species

    17&beta;-Hydroxysteroid dehydrogenases (17&beta;-HSDs) as therapeutic targets: Protein structures, functions, and recent progress in inhibitor development.

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    17&beta;-Hydroxysteroid dehydrogenases (17&beta;-HSDs) are oxidoreductases, which play a key role in estrogen and androgen steroid metabolism by catalyzing final steps of the steroid biosynthesis. Up to now, 14 different subtypes have been identified in mammals, which catalyze NAD(P)H or NAD(P)(+) dependent reductions/oxidations at the 17-position of the steroid. Depending on their reductive or oxidative activities, they modulate the intracellular concentration of inactive and active steroids. As the genomic mechanism of steroid action involves binding to a steroid nuclear receptor, 17&beta;-HSDs act like pre-receptor molecular switches. 17&beta;-HSDs are thus key enzymes implicated in the different functions of the reproductive tissues in both males and females. The crucial role of estrogens and androgens in the genesis and development of hormone dependent diseases is well recognized. Considering the pivotal role of 17&beta;-HSDs in steroid hormone modulation and their substrate specificity, these proteins are promising therapeutic targets for diseases like breast cancer, endometriosis, osteoporosis, and prostate cancer. The selective inhibition of the concerned enzymes might provide an effective treatment and a good alternative to the existing endocrine therapies. Herein, we give an overview of functional and structural aspects for the different 17&beta;-HSDs. We focus on steroidal and non-steroidal inhibitors recently published for each subtype and report on existing animal models for the different 17&beta;-HSDs and the respective diseases. Article from the Special issue on Targeted Inhibitors
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