378 research outputs found
Ab initio prediction of magnetically dead layers in freestanding -Ce(111)
It is well known that the surface of nonmagnetic -Ce is magnetically
ordered, i.e., -like. One then might conjecture, in agreement with
previous theoretical predictions, that the -Ce may also exhibit at its
surfaces even more strongly enhanced -like magnetic ordering.
Nonetheless, our result shows that the (111)-surfaces of magnetic -Ce
are neither spin nor orbitally polarized, i.e., -like. Therefore, we
predict, in contrast to the nonmagnetic -phase which tends to produce
magnetically ordered -like thin layers at its free surfaces, the
magnetic -phase has a tendency to form -like dead layers. This
study, which explains the suppressed (promoted) surface magnetic moments of
-Ce (-Ce), shows that how nanoscale can reverse physical
properties by going from bulk to the surface in isostructural - and
-phases of cerium. We predict using our freestanding surface results
that a typical unreactive and non-diffusive substrate can dramatically
influence the magnetic surface of cerium thin films in contrast to most of the
uncorrelated thin films and strongly correlated transition metals. Our result
implies that magnetic surface moments of -Ce(111) can be suddenly
disappeared by increasing lattice mismatch at the interface of a typical
unreactive and non-diffusive substrate with cerium overlayers.Comment: 6 pages, 3 figures, 1 tabl
Cerebellum and Ocular Motor Control
An intact cerebellum is a prerequisite for optimal ocular motor performance. The cerebellum fine-tunes each of the subtypes of eye movements so they work together to bring and maintain images of objects of interest on the fovea. Here we review the major aspects of the contribution of the cerebellum to ocular motor control. The approach will be based on structural–functional correlation, combining the effects of lesions and the results from physiologic studies, with the emphasis on the cerebellar regions known to be most closely related to ocular motor function: (1) the flocculus/paraflocculus for high-frequency (brief) vestibular responses, sustained pursuit eye movements, and gaze holding, (2) the nodulus/ventral uvula for low-frequency (sustained) vestibular responses, and (3) the dorsal oculomotor vermis and its target in the posterior portion of the fastigial nucleus (the fastigial oculomotor region) for saccades and pursuit initiation
VIRTUAL SIMULATION OF PMM TESTS INDEPENDENT OF TEST PARAMETERS
The dynamic planar motion mechanism (PMM) tests are simulated numerically using computational fluid dynamics for a prolate spheroid underwater vehicle (PSUV) to find the effects of test parameters: the amplitude, frequency and flow velocity, and make the simulation independent of them. An amplitude of the sinusoidal path of the pure sway and heave tests less than 0.01L and a frequency less than 0.03 Hz are necessary to find accurate results for the maneuvering hydrodynamic derivatives. A ratio of angular frequency to the flow velocity equal to one and an amplitude of less than 0.03L provide relatively accurate results for pure yaw and pitch tests. The calculated test parameters are validated using them for the simulation of the PMM tests for two SUBOFF submarine models to control and compare with the experimental results
Chromatin Structure in Cell Differentiation, Aging and Cancer
Chromatin is the structure that the eukaryotic genome is packaged into, allowing over a
metre of DNA to fit into the small volume of the nucleus. It is composed of DNA and proteins,
most of which are histones. This DNA-protein complex is the template for a number of
essential cell processes including transcription and replication. The basic structural unit of
chromatin is the nucleosome. Nucleosomes comprise around 146 base pairs of DNA wrapped
in a left-handed superhelix 1.7 times around a core histone octamer. This 11nm fibre is often
referred to as ‘beads on a string’. Chromatin assembly involves wrapping of DNA
around histone octameres producing repetitive nucleosomal array followed by folding of
chromatin fibre into solenoid-like structure and deposition of non-histone proteins
Assessing the feasibility of impregnating phase change materials in lightweight aggregate for development of thermal energy storage systems
This paper assesses the feasibility of impregnation/encasement of phase change materials (PCMs) in
lightweight aggregates (LWAs). An impregnation process was adopted to carry out the encasement study
of two different PCMs in four different LWAs. The leakage of the impregnated/encased PCMs was studied
when they were submitted to freeze/thawing and oven drying tests, separately. The results confirmed
that, the impregnation/encasement method is effective with respect to the large thermal energy storage
density, and can be suitable for applications were PCMs cannot be incorporated directly such as asphalt
road pavements.The authors acknowledge the funding given by Centre for Coordination and Regional Development Committee (CCDR-C) through the research project CENTRO-07-ST24_FEDER-002020 "Environmentally-Friendly Aeronautical Transport Systems Integrated Program (EFATRAS)", http://efatrasubi.wordpress.com. Supply of Expanded Clay materials by ARGEX - Argila Expandida, S.A and Cork materials by Sofalca - Sociedade Central de Productos de Cortica, Lda are also acknowledged
New report of Pullimosina heteroneura (Dip.: Sphaeroceridae) from Iran
During a study on the pests of button mushrooms in the city of Kermanshah, the sphaerocerid species of Pullimosina heteroneura (Haliday) was collected from mushroom culture media. This species is a new record for the Iranian insect fauna
Optimal behavior of responsive residential demand considering hybrid phase change materials
Due to communication and technology developments, residential consumers are enabled to participate in Demand Response Programs (DRPs), control their consumption and decrease their cost by using Household Energy Management (HEM) systems. On the other hand, capability of energy storage systems to improve the energy efficiency causes that employing Phase Change Materials (PCM) as thermal storage systems to be widely addressed in the building applications. In this paper, an operational model of HEM system considering the incorporation of more than one type of PCM in plastering mortars (hybrid PCM) is proposed not only to minimize the customerâ s cost in different DRPs but also to guaranty the habitantsâ  satisfaction. Moreover, the proposed model ensures the technical and economic limits of batteries and electrical appliances. Different case studies indicate that implementation of hybrid PCM in the buildings can meaningfully affect the operational pattern of HEM systems in different DRPs. The results reveal that the customerâ s electricity cost can be reduced up to 48% by utilizing the proposed model.The work of M. Shafie-khah and J.P.S. Catalão was supported by
FEDER funds through COMPETE and by Portuguese funds through FCT, under FCOMP-01-0124-FEDER-020282 (Ref. PTDC/EEA-EEL/118519/2010) and UID/CEC/50021/2013, and also by the EU 7th Framework Programme FP7/2007-2013 under Grant agreement No. 309048 (project SiNGULAR)
Comprehensive Techno-Economic Analysis of a Multi-Feedstock Biorefinery Plant in Oil-Rich Country: A Case Study of Iran
This is the final version. Available on open access from MDPI via the DOI in this recordThe high energy consumption in Iran, particularly in the transportation sector, has contaminated large cities and jeopardized the society health. Therefore, in this study technical and economic features of the production of biodiesel plant in Iran from various wastes are investigated. Based on the Analytic Hierarchy Process (AHP) method’s findings, the southern area of Iran is selected for establishing the biodiesel plant in Iran. The biorefinery, which includes three units of sewage sludge, edible waste oil and microalgae. The results of the economic evaluation show that the lowest costs of investment and production of biodiesel are related to microalgae units (0.53/kg), respectively. Also, among all units, the lowest break even prices are related to biodiesel production ($1.17/kg) and the highest ATROR rate (29.16%) belongs to the microalgae unit. This indicates that this unit is more profitable than other units and the invested cost is returned to the investor in a shorter period of time (3.43 years). On the other hand, the results of sensitivity analysis show that the highest sensitivity of changes in the selling price of biodiesel and the cost of raw materials to ATROR to the microalgae and sludge unit. Therefore, the construction of a biorefinery in Iran has an economic justification
Microcephaly with simplified gyration, epilepsy, and infantile diabetes linked to inappropriate apoptosis of neural progenitors
We describe a syndrome of primary microcephaly with simplified gyral pattern in combination with severe infantile epileptic encephalopathy and early-onset permanent diabetes in two unrelated consanguineous families with at least three affected children. Linkage analysis revealed a region on chromosome 18 with a significant LOD score of 4.3. In this area, two homozygous nonconserved missense mutations in immediate early response 3 interacting protein 1 (IER3IP1) were found in patients from both families. IER3IP1 is highly expressed in the fetal brain cortex and fetal pancreas and is thought to be involved in endoplasmic reticulum stress response. We reported one of these families previously in a paper on Wolcott-Rallison syndrome (WRS). WRS is characterized by increased apoptotic cell death as part of an uncontrolled unfolded protein response. Increased apoptosis has been shown to be a cause of microcephaly in animal models. An autopsy specimen from one patient showed increased apoptosis in the cerebral cortex and pancreas beta cells, implicating premature cell death as the pathogenetic mechanism. Both patient fibroblasts and control fibroblasts treated with siRNA specific for IER3IP1 showed an increased susceptibility to apoptotic cell death under stress conditions in comparison to controls. This directly implicates IER3IP1 in the regulation of cell survival. Identification of IER3IP1 mutations sheds light on the mechanisms of brain development and on the pathogenesis of infantile epilepsy and early-onset permanent diabetes.Facultad de Ciencias Médica
Microcephaly with simplified gyration, epilepsy, and infantile diabetes linked to inappropriate apoptosis of neural progenitors
We describe a syndrome of primary microcephaly with simplified gyral pattern in combination with severe infantile epileptic encephalopathy and early-onset permanent diabetes in two unrelated consanguineous families with at least three affected children. Linkage analysis revealed a region on chromosome 18 with a significant LOD score of 4.3. In this area, two homozygous nonconserved missense mutations in immediate early response 3 interacting protein 1 (IER3IP1) were found in patients from both families. IER3IP1 is highly expressed in the fetal brain cortex and fetal pancreas and is thought to be involved in endoplasmic reticulum stress response. We reported one of these families previously in a paper on Wolcott-Rallison syndrome (WRS). WRS is characterized by increased apoptotic cell death as part of an uncontrolled unfolded protein response. Increased apoptosis has been shown to be a cause of microcephaly in animal models. An autopsy specimen from one patient showed increased apoptosis in the cerebral cortex and pancreas beta cells, implicating premature cell death as the pathogenetic mechanism. Both patient fibroblasts and control fibroblasts treated with siRNA specific for IER3IP1 showed an increased susceptibility to apoptotic cell death under stress conditions in comparison to controls. This directly implicates IER3IP1 in the regulation of cell survival. Identification of IER3IP1 mutations sheds light on the mechanisms of brain development and on the pathogenesis of infantile epilepsy and early-onset permanent diabetes.Facultad de Ciencias Médica
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