178 research outputs found
Student Teacher Interaction While Learning Computer Science: Early Results from an Experiment on Undergraduates
The scope of this paper was to find out how the students in Computer Science
perceive different teaching styles and how the teaching style impacts the
learning desire and interest in the course. To find out, we designed and
implemented an experiment in which the same groups of students (86 students)
were exposed to different teaching styles (presented by the same teacher at a
difference of two weeks between lectures). We tried to minimize external
factors' impact by carefully selecting the dates (close ones), having the
courses in the same classroom and on the same day of the week, at the same
hour, and checking the number and the complexity of the introduced items to be
comparable. We asked for students' feedback and we define a set of countable
body signs for their involvement in the course. The results were comparable by
both metrics (body language) and text analysis results, students prefer a more
interactive course, with a relaxing atmosphere, and are keener to learn in
these conditions.Comment: CSEDU 2023, 15th International Conference on Computer Supported
Educatio
Terra Incognita 4-The European Adventure: a collaborative, affective-aware, SMS and web-based learning system
In this paper we present a hybrid SMS and web-based game-like learning system. We designed and practically proofed the SMS and web-based four tier system. Our main goal was to provide a community information service that implies the ability to work with PCs and mobile phones, proactive attitude in searching for information, knowledge acquisition and sharing about the European Union, in a pleasant learning environment. The three-month project hosted around 2000 gamers that had a minimum 10 days virtual journey in the European cities. The results are good and are detailed in the article. Almost all participants that responded to the questionnaire are willing to continue to play a similar kind of game.Technical University of Cluj-Napoca (only the first author), AltArt Foundatio
Training the Behaviour Preferences on Context Changes
Personalized ambient intelligent systems should meet changes in user’s needs, which evolve over time. Our objective is to create an adaptive system that learns the user behaviour preferences. We propose *BAM – * Behaviour Adaptation Mechanism, a neural-network based control system that is trained, supervised by user’s (affective) feedback in real-time. The system deduces the preferred behaviour, based on the detection of affective state’s valence (negative, neutral and positive) from facial features analysis. The neural network is retrained periodically with the updated training set, obtained from the interpretation of the user’s reaction to the system’s decisions. We investigated how many training examples, rendered from user’s behaviour, are required in order to train the neural network so that it reaches an accuracy of at least 75%. We present the evolution of behaviour preference learning parameters when the number of context elements increases
Use of silicoater procedure in dentistry
Od 1936. godine kada su prvi puta upotrebljeni PMMA sintetske tvari
u stomatologiji, zbivale su se do danas na ovom području bitne promjene. Tim razvojem mogli su se mnogi nedostaci koje ove tvari posjeduju poboljšati, kao na pr. nedovoljna otpornost na trošenje, bubrenje radi upijanja vode i stvaranje pukotine na granici metala i sintetske fasete, čime je omogućen ulazak bakterija, tako da se već nakon dvije godine smanjuje odnosno gubi estetika. Ti se nedostaci međutim nisu mogli ukloniti. Spoznaja da je stvaranje pukotine na granici metala i sintetske tvari ključni problem gubitka estetike faseta, dovela je do poboljšanja adhezivnih svojstava na površini metala.
Musil i Tiller razvili su specijalni sistem slojeva koji ima i prema površini metala, kao i prema sintetskoj tvari kemijski spoj. Spoj metala i sintetske tvari bez pukotine u Silicoater postupku otvara sintetskim tvarima nove i bolje mogućnosti primjene. Prednosti su:
1. u tehnici teleskopskih krunica, 2. pri lijevanim protezama, 3. kod ljepljenih mostova (Maryland mostovi), 4. u ortodonciji.
Mi smo uspjeli u eksperimentalnoj studiji dokazati bitno poboljšanje čvrstoće veze ako se površina pripremi silikoterskim postupkom. Pri tome smo međusobno slijepili kompozitnim sintetskim tvarima tri neplemenite i dvije plemenite slitine s različitom površinskom pripremom.Since 1936, when the PMMA synthetic substances were first used in dentistry, some substantial changes have taken place in this branch. These advances have led to an improvement in the management of defects of these substances such as inadequate resistance to wear by use, swelling due to absorption of water and formation on the border between the metal and a syntehtic facet, allowing bacteria in and resulting in a decrease or even loss of the esthetic aspect already after two years. These defects, though, could not be eliminated. Recognition of the formation of fissures on the border between the metal and a synthetic substance as the key problem leading to loss of
the esthetic quality of facets has resulted in a improvement of adhesive characteristics on the metal surface. Musil and Tiller have devolped a special system of layers, chemically linked to both the metal surface and the synthetic substance. A fissure-free junction between the metal and a synthetic substance in the Silicoater procedure provides new and better possibilities for use synthetic substances in dentistry. The following advantages have been observed: (1) use of a technique of telescopic crowns; (2) in cast prostheses; (3) in cemented glued bridgs (Maryland bridges); and (4) in orthodontics. A substantial improvement in the junction firmness, achieved by treating the surface by the Silicoater procedure, was ascertained in this study. Three base and two noble alloys with different surface preparation were mutually cemented glued together using composite synthetic substances
Complex Evolutionary History With Extensive Ancestral Gene Flow in an African Primate Radiation
Understanding the drivers of speciation is fundamental in evolutionary biology, and recent studies highlight hybridization as an important evolutionary force. Using whole-genome sequencing data from 22 species of guenons (tribe Cercopithecini), one of the world's largest primate radiations, we show that rampant gene flow characterizes their evolutionary history and identify ancient hybridization across deeply divergent lineages that differ in ecology, morphology, and karyotypes. Some hybridization events resulted in mitochondrial introgression between distant lineages, likely facilitated by cointrogression of coadapted nuclear variants. Although the genomic landscapes of introgression were largely lineage specific, we found that genes with immune functions were overrepresented in introgressing regions, in line with adaptive introgression, whereas genes involved in pigmentation and morphology may contribute to reproductive isolation. In line with reports from other systems that hybridization might facilitate diversification, we find that some of the most species-rich guenon clades are of admixed origin. This study provides important insights into the prevalence, role, and outcomes of ancestral hybridization in a large mammalian radiation
Ancient DNA of the pygmy marmoset type specimen Cebuella pygmaea (Spix, 1823) resolves a taxonomic conundrum
The pygmy marmoset, the smallest of the anthropoid primates, has a broad distribution in Western Amazonia. Recent studies using molecular and morphological data have identified two distinct species separated by the Napo and Solimões-Amazonas rivers. However, reconciling this new biological evidence with current taxonomy, i.e., two subspecies, Cebuella pygmaea pygmaea (Spix, 1823) and Cebuella pygmaea niveiventris (Lönnberg, 1940), was problematic given the uncertainty as to whether Spix's pygmy marmoset (Cebuella pygmaea pygmaea) was collected north or south of the Napo and Solimões-Amazonas rivers, making it unclear to which of the two newly revealed species the name pygmaea would apply. Here, we present the first molecular data from Spix's type specimen of Cebuella pygmaea, as well as novel mitochondrial genomes from modern pygmy marmosets sampled near the type locality (Tabatinga) on both sides of the river. With these data, we can confirm the correct names of the two species identified, i.e., C. pygmaea for animals north of the Napo and Solimões-Amazonas rivers and C. niveiventris for animals south of these two rivers. Phylogenetic analyses of the novel genetic data placed into the context of cytochrome b gene sequences from across the range of pygmy marmosets further led us to reevaluate the geographical distribution for the two Cebuella species. We dated the split of these two species to 2.54 million years ago. We discuss additional, more recent, subdivisions within each lineage, as well as potential contact zones between the two species in the headwaters of these rivers
The humidity level matters during the desiccation of Norway spruce somatic embryos
In Norway spruce, as in many other conifers, the germination capacity of somatic embryos is strongly influenced by the desiccation phase inserted after maturation. The intensity of drying during desiccation eminently affected the formation of emblings (i.e., seedlings developed from somatic embryos). Compared to non-desiccated embryos, the germination capacity of embryos desiccated at 100% relative humidity was about three times higher, but the reduction of relative humidity to 95 and 90% had a negative effect on the subsequent embryo development. The water loss observed in these embryos did not lead to an increase in lipid peroxidation, as shown by malondialdehyde levels. Another metabolic pathway in plants that mediates a response to abiotic stresses is directed toward the biosynthesis of polyamines (PAs). The activities of PA biosynthetic enzymes increased steadily in embryos during desiccation at 100% relative humidity, whereas they decreased at lower humidity. The total content of free PAs in the embryos gradually decreased throughout desiccation. The increase in free putrescine (Put) and perchloric acid-insoluble Put conjugates was observed in embryos desiccated at lower humidity. These changes were accompanied to some extent by the transcription of the genes for the PA biosynthesis enzymes. Desiccation at 100% relative humidity increased the activity of the cell wall-modifying enzymes β-1,3-glucanases and chitinases; the activities of these enzymes were also significantly suppressed at reduced humidity. The same pattern was observed in the transcription of some β-1,3-glucanase and chitinase genes. Desiccation treatments triggered metabolic processes that responded to water availability, suggesting an active response of the embryo to the reduction in humidity. A positive effect was demonstrated only for desiccation at high relative humidity. Some of the physiological characteristics described can be used as markers of inappropriate relative humidity during somatic embryo desiccation
Ancient DNA of the Pygmy Marmoset Type Specimen \u3cem\u3eCebuella pygmaea\u3c/em\u3e (Spix, 1823) Resolves a Taxonomic Conundrum
The pygmy marmoset, the smallest of the anthropoid primates, has a broad distribution in Western Amazonia. Recent studies using molecular and morphological data have identified two distinct species separated by the Napo and Solimões-Amazonas rivers. However, reconciling this new biological evidence with current taxonomy, i.e., two subspecies, Cebuella pygmaea pygmaea (Spix, 1823) and Cebuella pygmaea niveiventris (Lönnberg, 1940), was problematic given the uncertainty as to whether Spix’s pygmy marmoset (Cebuella pygmaea pygmaea) was collected north or south of the Napo and Solimões-Amazonas rivers, making it unclear to which of the two newly revealed species the name pygmaea would apply. Here, we present the first molecular data from Spix’s type specimen of Cebuella pygmaea, as well as novel mitochondrial genomes from modern pygmy marmosets sampled near the type locality (Tabatinga) on both sides of the river. With these data, we can confirm the correct names of the two species identified, i.e., C. pygmaea for animals north of the Napo and Solimões-Amazonas rivers and C. niveiventris for animals south of these two rivers. Phylogenetic analyses of the novel genetic data placed into the context of cytochrome b gene sequences from across the range of pygmy marmosets further led us to re-evaluate the geographical distribution for the two Cebuella species. We dated the split of these two species to 2.54 million years ago. We discuss additional, more recent, subdivisions within each lineage, as well as potential contact zones between the two species in the headwaters of these rivers
Study of the human African genome landscape through the analysis of complete genomes
Trabajo presentado en la Annual Meeting of the Society for Molecular Biology and Evolution (SMBE 2015), celebrada en Viena del 12 al 16 de julio de 2015.Understanding the genetic diversity in humans within the African continent is pivotal to
have a full picture of the demographic history of the human species. Here, we study
complete genome sequeces of a diverse panel of African individuals in terms of
geographical location, linguistic context and lifestyle.
Most African diversity studies have mainly
focused on uniparental markers or selected
autosomal markers, which introduce
an ascertainment bias in the analysis.
The analysis of complete genomes
has been poorly developed in the
study of African human genomics
and internal population diversity.
The main goals of this study are:
1. Characterisation of the internal
human diversity in Africa overcoming
ascertainment bias-related problems
by using complete genomes.
2. Characterization of the deepest
splits in the human lineage and
the processes (such as migrations
and admixtures) that have shaped
the current genetic map.Funded by: MINECO CGL 2013-44351-P.N
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