8,829 research outputs found

    Mean first passage time analysis reveals rate-limiting steps, parallel pathways and dead ends in a simple model of protein folding

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    We have analyzed dynamics on the complex free energy landscape of protein folding in the FOLD-X model, by calculating for each state of the system the mean first passage time to the folded state. The resulting kinetic map of the folding process shows that it proceeds in jumps between well-defined, local free energy minima. Closer analysis of the different local minima allows us to reveal secondary, parallel pathways as well as dead ends.Comment: 7 page

    Human subjective response to steering wheel vibration caused by diesel engine idle

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    This study investigated the human subjective response to steering wheel vibration of the type caused by a four-cylinder diesel engine idle in passenger cars. Vibrotactile perception was assessed using sinusoidal amplitude-modulated vibratory stimuli of constant energy level (r.m.s. acceleration, 0.41 m/s(2)) having a carrier frequency of 26 Hz (i.e. engine firing frequency) and modulation frequency of 6.5 Hz (half-order engine harmonic). Evaluations of seven levels of modulation depth parameter m (0.0, 0.1, 0.2, 0.4, 0.6, 0.8, and 1.0) were performed in order to define the growth function of human perceived disturbance as a function of amplitude modulation depth. Two semantic descriptors were used (unpleasantness and roughness) and two test methods (the Thurstone paired-comparison method and the Borg CR-10 direct evaluation scale) for a total of four tests. Each test was performed using an independent group of 25 individuals. The results suggest that there is a critical value of modulation depth m = 0.2 below which human subjects do not perceive differences in amplitude modulation and above which the stimulus-response relationship increases monotonically with a power function. The Stevens power exponents suggest that the perceived unpleasantness is non-linearly dependent on modulation depth m with an exponent greater than 1 and that the perceived roughness is dependent with an exponent close to unity

    A Lotus japonicus cDNA Encoding an [alpha] Subunit of a Heterotrimeric G-Protein

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    Lifelong learning and schools as community learning centres : key aspects of a national curriculum draft policy framework for Malta

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    The island of Malta has been engaged in policy document formulations for curriculum renewal in the country’s educational system (4-16 years of age) since 1988 when the first National Minimum Curriculum (henceforth NMC) was launched (Wain, 1991; Borg et al, 1995). In 1999 a revamped NMC (Ministry of Education, 1999) was developed following a long process of consultation involving various stages and stakeholders. It was a compromise document (Borg & Mayo, 2006) which emerged as a result of reactions to a more radical and coherent draft document produced in 1988. Both curricular documents were subject to debates and critiques (Wain, 1991; Darmanin, 1993; Borg et al, 1995; Giordmaina, 2000; Borg and Mayo, 2006). More recently a series of volumes providing guidelines, key principles and aims for a national curriculum framework (henceforth NCF) have been produced (MEEF, 2011a,b,c,d) and are currently the target of debate and the focus of reactions by various stakeholders in education including teachers who were asked to read the volumes and provide reactions in the form of answers to a set questionnaire. In this paper, I will focus on one aspect of the documents, the first of its three aims: ‘Learners who are capable of successfully developing their full potential as lifelong learners.’ It is that aspect of the framework documents that falls within the purview of the title for this special issue. The use of this notion attests to the influence of the EU’s policy communications on member states, Malta having joined the Union in 2004 (Mayo, 2007).peer-reviewe

    A study of semantic memory after brain injury: Learning newly coined French words

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    AbstractObjectiveTo investigate semantic memory in brain-injured patients.MethodsWe used the new word questionnaire (QMN) to assess the ability of 12 brain-injured patients and 12 healthy controls to define French words, which had been admitted to the dictionary in 1996 to 1997 or in 2006 to 2007.ResultsDespite amnesia or severe executive disorders, the brain-injured patients were able to learn new words and remember those that they already learnt. They successfully selected the relevant phrase in which the new word was placed and were reasonably good at recognizing the right definition from among decoys. In contrast, they had trouble defining the words and compensated for this by giving examples. These problems were correlated with their vocabulary and executive function scores in a battery of neuropsychological tests.ConclusionOur results suggest that frontal injury leads to an impairment in accurate word selection and the scheduling abilities required to generate word definitions

    Hymn to the heroes of Malta

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    Ġabra ta’ poeżiji u proża li tinkludi: Alla fil-ħolqien ta’ Ġużè Agius Bonello – Is-sena u l-bniedem ta’ Ġużè Ellul-Mercer – Li tiżra’ taħsad ta’ Vic. Apap – Huwa ta’ Gino Muscat-Azzopardi – Żewġ friefet ta’ Vincent Caruana – Iċ-ċagħka ta’ Ġużè Borg – Warda midbiela ta’ C. Gauci – It-tfajla tas-sulfarini ta’ Albert M. Cassola – L-aħħar traduzzjoni ta’ May Butcher qabel ma mietet – Hymn to the heroes of Malta.N/

    My heart is racing! Psychophysiological dynamics of skilled racecar drivers

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    Our purpose was to test the multi-action plan (MAP) model assumptions in which athletes’ psychophysiological patterns differ among optimal and suboptimal performance experiences. Nine professional drivers competing in premier race categories (e.g., Formula 3, Porsche GT3 Cup Challenge) completed the study. Data collection involved monitoring the drivers’ perceived hedonic tone, accuracy on core components of action, posture, skin temperature, respiration rate, and heart rate responses during a 40-lap simulated race. Time marks, gathered at three standardized sectors, served as the performance variable. The A1GP racing simulator (Allinsport, Modena) established a realistic race platform. Specifically, the Barcelona track was chosen due to its inherently difficult nature characterized by intermittent deceleration points. Idiosyncratic analyses showed large individual differences in the drivers’ psychophysiological profile, as well as distinct patterns in regards to optimal and suboptimal performance experiences. Limitations and future research avenues are discussed. Action (e.g., attentional control) and emotion (e.g., biofeedback training) centered applied sport psychology implications are advanced

    Social difference, cultural arbitrary and identity : an analysis of a new national curriculum document in a non-secular environment

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    This article focuses on the idea of the Curriculum as a 'selection from the cultures of society' and as a site of contestation for legitimacy and identity affirmation. The purpose is to shed some light on the nature of curricular reform being advocated in a specific context - Malta. Throughout the past four years, there has been a revamping of the National Minimum Curriculum (NMC) document in Malta, established in 1988. The 'old' National Minimum Curriculum was subject to criticism focusing on a variety of issues (echoing criticisms levelled at similar National Curricula elsewhere), including issues concerning difference and identity. The first part of the article deals briefly with the issues concerning difference raised in this criticism, focusing on the issues of class, race/ethnicity, gender and disability. The second part focuses on the long and gradual build up towards the development of the new National Curriculum document. The process centres around two documents, the preliminary Tomorrow's Schoolsdocument and the draft NMC document. The issues of equity and the affirmation of social difference, as well as the move towards de-streaming, are discussed. It is argued that this process of reform benefited from the criticism of the earlier NMC document. The process of reform involved an attempt at widespread participation by various stakeholders - parents, teachers, students, unions, women's organisations, disabled person's organisations etc. The final section focuses on the final new NMC document. In this section, the authors explore the compromises, which have been made in reaction to the draft document, indicating the interests at play. Whose cultural arbitrary is reflected in the final document? The article concludes with a discussion centring around lessons to be drawn from a process of curricular reform, involving issues related to identity and difference, carried out in a country characterised by a non-secular environment.peer-reviewe

    Interrelation of structural and electronic properties of InGaN/GaN quantum dots using an eight-band k.p model

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    We present an eight-band k.p model for the calculation of the electronic structure of wurtzite semiconductor quantum dots (QDs) and its application to indium gallium nitride (InGaN) QDs formed by composition fluctuations in InGaN layers. The eight-band k.p model accounts for strain effects, piezoelectric and pyroelectricity, spin-orbit and crystal field splitting. Exciton binding energies are calculated using the self-consistent Hartree method. Using this model, we studied the electronic properties of InGaN QDs and their dependence on structural properties, i.e., their chemical composition, height, and lateral diameter. We found a dominant influence of the built-in piezoelectric and pyroelectric fields, causing a spatial separation of the bound electron and hole states and a redshift of the exciton transition energies. The single-particle energies as well as the exciton energies depend heavily on the composition and geometry of the QDs

    Comparison of the peripheral blood eosinophil count using near-patient testing and standard automated laboratory measurement in healthy, asthmatic and COPD subjects

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    Near-patient testing (NPT) allows clinical decisions to be made in a rapid and convenient manner and is often cost effective. In COPD the peripheral blood eosinophil count has been demonstrated to have utility in providing prognostic information and predicting response to treatment during an acute exacerbation. For this potential to be achieved having a reliable NPT of blood eosinophil count would be extremely useful. Therefore, we investigated the use of the HemoCue® WBC Diff System and evaluated its sensitivity and specificity in healthy, asthmatic and COPD subjects. This method requires a simple skin prick of blood and was compared to standard venepuncture laboratory analysis. The HemoCue® WBC Diff System measured the peripheral blood eosinophil count in healthy, asthma and COPD subjects with very close correlation to the eosinophil count as measured by standard venepuncture. The correlations were unaffected by disease status. This method for the measurement of the peripheral blood eosinophil count has the potential to provide rapid near-patient results and thus influence the speed of management decisions in the treatment of airway diseases
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