380 research outputs found

    On the Continuity Mathematics Curriculum Between Primary and Secondary School

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    AbstractIn this paper we intend to present a review of the National Curriculum continuity in mathematics, in terms of content, from the primary to the secondary. The issues on which we have committed are related to “outputs” learning mathematics fourth class and “inputs” appropriate grade. Because a complete analysis of mathematics curricular content can not be included in an article like this, we summarize only the learning content “fraction”. As far we know, continuity issues relating to both the content of their purchases to specific skills training to students, standards and performance descriptors etc., relative to a subject or a curriculum area, in recent formulation, not be found treated in the literature, even in the didactics of discipline

    User evaluation of an interactive learning framework for single-arm and dual-arm robots

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    The final publication is available at link.springer.comSocial robots are expected to adapt to their users and, like their human counterparts, learn from the interaction. In our previous work, we proposed an interactive learning framework that enables a user to intervene and modify a segment of the robot arm trajectory. The framework uses gesture teleoperation and reinforcement learning to learn new motions. In the current work, we compared the user experience with the proposed framework implemented on the single-arm and dual-arm Barrett’s 7-DOF WAM robots equipped with a Microsoft Kinect camera for user tracking and gesture recognition. User performance and workload were measured in a series of trials with two groups of 6 participants using two robot settings in different order for counterbalancing. The experimental results showed that, for the same task, users required less time and produced shorter robot trajectories with the single-arm robot than with the dual-arm robot. The results also showed that the users who performed the task with the single-arm robot first experienced considerably less workload in performing the task with the dual-arm robot while achieving a higher task success rate in a shorter time.Peer ReviewedPostprint (author's final draft

    Molecular mechanisms of RET receptor-mediated oncogenesis in multiple endocrine neoplasia 2

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    Multiple endocrine neoplasia type 2 is an inherited cancer syndrome characterized by tumors of thyroid and adrenal tissues. Germline mutations of the REarranged during Transfection (RET) proto-oncogene, leading to its unregulated activation, are the underlying cause of this disease. Multiple endocrine neoplasia type 2 has been a model in clinical cancer genetics, demonstrating how knowledge of the genetic basis can shape the diagnosis and treatment of the disease. Here, we discuss the nature and effects of the most common recurrent mutations of RET found in multiple endocrine neoplasia type 2. Current understanding of the molecular mechanisms of RET mutations and how they alter the structure and function of the RET protein leading to its aberrant activation, and the effects on RET localization and signaling are described

    Vitamin D-Resistant Rickets and Cinacalcet—One More Favorable Experience

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    Hereditary vitamin D-resistant rickets (HVDRR) is an autosomal recessive disorder characterized by early onset of severe rickets, with a complete triad of clinical, biochemical and skeletal abnormalities. Homozygous or heterozygous mutations in the vitamin D receptor (VDR) gene leading to complete or partial target organ resistance to the action of 1α, 25-dihydroxyvitamin D3 (the active form of vitamin D) are responsible for HVDRR. Theoretically the therapeutic goal is to overcome this tissue resistance, and to normalize calcium and phosphate homeostasis. Practically, the treatment could be oriented to correct the secondary hyperparathyroidism to avoid long-term negative impact on bone health. The conventional therapeutic strategy (high-dose calcium plus active vitamin D metabolites) gives variable responses in magnitude and duration. We report a case of HVDRR with heterozygous mutation in the VDR gene, neonatal alopecia, and a severe clinical phenotype diagnosed at the age of 30 months who showed unsatisfactory response to traditional therapy. The short-term responsiveness to cinacalcet was encouraging, with adequate correction of phosphate-calcium homeostasis and significant improvement of clinical and radiological status at 6 months of treatment

    Transient Cenozoic tectonic stages in the southern margin of the Caribbean plate : U-Th/He thermochronological constraints from Eocene plutonic rocks in the Santa Marta massif and SerranĂ­a de Jarara, northern Colombia

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    We use U-Th/(He) zircon and apatite thermochronology and Al in hornblende geobarometry from Eocene granitoids of the Sierra Nevada de Santa Marta and Guajira uplifted massifs in northern Colombia to elucidate the exhumation history of the northern South America continental margin and its bearing to Cenozoic Caribbean- South American plate interactions. Aluminium in hornblende geobarometry from the Eocene Santa Marta batholith yields pressures between 4.9±0.6kbar and 6.4±0.6kbar, which indicate that at least, 14.7-19.2km of unroofing took place since 56-50Ma in the northwestern Sierra Nevada de Santa Marta. In the Guajira Peninsula, calculated pressures for the Eocene Parashi stock are 2.3±0.6kbar and 3±0.6kbar. Stratigraphic considerations pertaining to Oligocene conglomerates from the Guajira area suggest that 6.9-9km of crust was lost between 50Ma and ca. 26Ma. U-Th/He zircon and apatite thermochronology from granitoids in the Sierra Nevada de Santa Marta shows the existence of major exhumation events in the Late Eocene (ca. 45-40Ma), Late Oligocene (ca. 25Ma) and Miocene (ca. 15Ma). The Guajira region records the Late Eocene to Early Oligocene (35-25Ma) event, but it lacks evidence for the Miocene exhumation phase. These differences reflect isolation of the Guajira region from the Sierra Nevada de Santa Marta and the Andean chain due to extensive block rotation and transtensional tectonics that affected the region during post-Eocene times. The post-Eocene events correlate in time with an increased convergence rate and the frontal approach of North and South America. It is suggested that the two major tectonic mechanisms that govern exhumation in these Caribbean massifs are: 1) subduction of the Caribbean plate, and 2) post Eocene changes in plate convergence obliquity and rates that caused the South American continental margin blocks to override the Caribbean plate. Temporal correlation with other Caribbean and Northern Andean events allows to resolve the regional Cenozoic plate tectonic reorganizations experienced by the South American, Caribbean and Pacific plates at a regional scale

    Diabetes Mellitus in a Patient With Lafora Disease: Possible Links With Pancreatic ÎČ-Cell Dysfunction and Insulin Resistance

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    Lafora disease (LD) is a rare autosomal recessive disorder characterized by progressive myoclonic epilepsy followed by continuous neurological decline, culminating in death within 10 years. LD leads to accumulation of insoluble, abnormal, glycogen–like structures called Lafora bodies (LBs). It is caused by mutations in the gene encoding glycogen phosphatase (EPM2A) or the E3 ubiquitin ligase malin (EPM2B/NHLRC1). These two proteins are involved in an intricate, however, incompletely elucidated pathway governing glycogen metabolism. The formation of EPM2A and malin signaling complex promotes the ubiquitination of proteins participating in glycogen metabolism, where dysfunctional mutations lead to the formation of LBs. Herein, we describe a 13-years-old child with LD due to a NHLRC1 (c.386C > A, p.Pro129His) mutation, who has developed diabetes mellitus and was treated with metformin. We discuss how basic mechanisms of LD could be linked to ÎČ-cell dysfunction and insulin resistance

    Spin asymmetries for elastic proton scattering and the spin dependent couplings of the Pomeron

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    This paper serves as a report on the large amount of analysis done in conjunction with the polarized proton program at RHIC. This comprises elastic scattering data of protons on protons in colliding beam or fixed target mode and proton beams on carbon targets. In addition to providing a model for the energy dependence of the analyzing power of elastic scattering needed for proton polarimetry, it also provides some significant information about the spin dependence of dominant Regge poles. Most notably, the data indicates that the Pomeron has a significant spin-flip coupling. This allows the exploration of the double spin flip asymmetry A_{NN} for which some data over a wide energy range is now available, along with a concrete realization of a proposed Odderon search.Comment: final reference modife

    Potential therapeutic applications of infusions and hydroalcoholic extracts of Romanian glutinous sage (Salvia glutinosa L.)

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    Ethnopharmacological relevance: Salvia glutinosa, also known as the glutinous sage, has been used in Romanian folk medicine in the treatment of inflammation, injuries, and mild infections. However, there is no direct scientific evidence to demonstrate these activities. Aim of the Study: The present research was based on evaluating antioxidant, antiproliferative, and α-glucosidase inhibitory activity of S. glutinosa extracts, as well as the in vivo anti-inflammatory activity. Materials and Methods: Infusions and 70% (v:v) ethanol solution extracts of S. glutinosa stems and leaves, collected from two different locations in Romania, were prepared. Ten phenolic compounds were identified and quantified using the LC-DAD-ESI/MSn method, and total phenolic and flavonoid content, as well as in vitro antioxidant (DPPH, ABTS, and FRAP assays), antiproliferative, antiinflammatory and alpha-glucosidase inhibitory activities were determined. A rat model of induced inflammation with turpentine oil was used for the examination of in vivo effects of the extracts, using diclofenac as an antiinflammatory control. Results: The highest inhibitory α-glucosidase activity was determined to be IC50 = 0.546 mg/ml for the hydroalcoholic extract made with plant material collected on the road to Sighișoara. The highest cytotoxic activity against HepG2 cell line was determined to be GI50 = 131.68 ± 5.03 ÎŒg/ml, for the hydroalcoholic extract made with plant material from Sighișoara. In vivo administration of extract (200 mg lyophilized powder/ml) showed a significant reduction of NO production.Conclusion: Our findings indicate that S. glutinosa extracts exhibit antioxidant, α-glucosidase inhibitory activity, as well as a modest cytotoxic effect on HepG2 cell line. By in vivo administration, the extracts show antiinflammatory and antioxidant activity, which correlates with the traditional use of the species. The environmental conditions seemed to induce important changes in the chemical composition and the bioactivity of the herbal preparations derived from S. glutinosa.This work was supported by a grant of the Romanian Ministry of Education and Research, CNCS–UEFISCDI, project number PN-III-P2-2.1-PED-2019–5360.info:eu-repo/semantics/publishedVersio

    A Novel and More Efficient Way to Grind Punching Tools

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    ABSTRACT A simulation model of punch grinding has been developed which calculates the instantaneous material-removal rate, arc length of contact and temperature based on the kinematic relationships between wheel and workiece and determines the optimum machine parameters to reduce cycle time and achieve a constant-temperature no-burn situation. Two basic outputs of the simulation model include arc length of contact and specific material-removal rate. A thermal model is included in the simulation to calculate maximum grinding zone temperature rise. A novel method is developed to constrain this temperature rise in the simulation. The thermal model inputs a constant value of specific grinding energy and the energy partition, which represents the fraction of the grinding energy conducted as heat to the workpiece. The simulation-based optimization can lead to a drastic reduction of grinding cycle time. Moreover, the limitation of maximum grinding zone temperature rise below the transitional temperature can help to avoid generation of workpiece thermal damage, which includes thermal softening, residual tensile stress, and rehardening burn. The grindability of high speed steel (HSS) is also discussed in terms of power consumption, specific grinding energy and undeformed chip thickness
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