511 research outputs found

    Patterning molecular scale paramagnets at Au Surface: A root to Magneto-Molecular-Electronics

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    Few examples of the exploitation of molecular magnetic properties in molecular electronics are known to date. Here we propose the realization of Self assembled monolayers (SAM) of a particular stable organic radical. This radical is meant to be used as a standard molecule on which to prove the validity of a single spin reading procedure known as ESR-STM. We also discuss a range of possible applications, further than ESR-STM, of magnetic monolayers of simple purely organic magnetic molecule.Comment: This preprint is currently partially under revisio

    The Role of Common Agricultural Policy in the Landscape Evolution: the Case Study of Val d'Orcia (Siena, Italy)

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    In the last years there is growing debate between agricultural economists on the role of agriculture to product positive ad negative externalities. The externalities are defined as pubblic goods or no-commodity outputs (Marangon, 2006; Daugstad et al., 2006; OECD, 2001; Brunori et al., 2006) and they need of specific regulation. In rural areas landscape is a typical example of externality because it is the result of agricultural activity and it changes with the agricultural change. At same time, landscape in specific territorial contexts can assume historic, cultural, social and economic value, so that it could become a strategic resource for local development politics (Brunori et al, 2006). The decupling and cross-compliance introduced by the new Common Agricultural Policy (CAP) and the increasing demand of environmental goods by citizen/consumers are elements of novelty that will modify farms in next years. In particular, CAP reform could lead to farm externalisation of activity or suspension of business in many rural areas with important socio-economic and environmental impacts as, for example, on landscape. In Val d’Orcia, as in other Tuscany rural areas, landscape assumes the role of economic resource because it attracts tourists and is utilised to promote the territory (landscape as a “business card”). This is in connection with the rural configuration of the landscape and the high concentration of architectonic and artistic goods. To remember, for example, the UNESCO recognition in 2004 as “Val d’Orcia cultural landscape”. At same time, if this landscape is an important points of strength of the local economy, it shows also environmental fragility (biodiversity reduction, soli erosion, etc.) that they need specific actions. In agreement with art.1 of European Landscape Convention (European Council, 2000) where is affirmed that “Landscape means an area, as perceived by people, whose character is the result of the action and interaction of natural and/or human factors”, this work shows the results of a survey developed in Val d’Orcia with this objectives: ‱ to identify the driving forces that have leaded to the current landscape in Val d’Orcia to start to 1970th; ‱ to try to define the possible landscape evolution in relationship with the novelty introduced by the CAP reform; ‱ to suggest specific actions to drive the landscape evolution in the direction of a “sustainable rural landscape” where landscape is an element to strengthen the identity of local rural community, to promote local sustainable development and to safeguard environmental resources in their complex (European Council, 2000)

    Do Akiskal & Mallya's affective temperaments belong to the domain of pathology or to that of normality?

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    BACKGROUND: Kraepelin and Kretschmer hypothesized a continuum between full-blown affective pathology and premorbid temperaments. More recently Akiskal proposed a putative adaptive role for the four fundamental temperaments: the hyperthymic one characterized by emotional intensity, the cyclothymic one by emotional instability, the depressive one by a low energy level, and the irritable one by an excessive response to stimuli. Today it is widely debated whether affective temperaments belong to the domain of pathology or to that of normality. PURPOSE: To make clear, by applying an integrated model, the position of affective temperaments within the continuum between normality and pathology. METHODS: We reviewed several papers that explore the distribution of affective temperaments among the general population, and their involvement both in pathological conditions (somatic and psychiatric) and in human activities (professions and other occupations). RESULTS: Far from being intrinsically pathological conditions, affective temperaments seem to represent adaptive dispositions whose dysregulation can lead to full-blown affective pathology. All the temperamental types display some impact on people's lives by influencing personal skills and professional choices over a wide field of human activities. CONCLUSIONS: Affective temperaments are not problematic when they appear in a mild form, but when they occur in extreme form we have observed a gap between the hyperthymic temperament, which represents the most functional and desirable, and the cyclothymic, depressive, irritable and phobic anxious ones, which are closer to mood, anxiety, and substance use disorders, and imply a component of somatic diseases and life stressors

    Social presence in the 21st Century: an adjustment to the Community of Inquiry framework

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    The Community of Inquiry framework, originally proposed by Garrison, Anderson and Archer (2000) identifies teaching, social and cognitive presences as central to a successful online educational experience. This article presents the findings of a study conducted in Uruguay between 2007 and 2010. The research aimed to establish the role of cognitive, social and teaching presences in the professional development of 40 English language teachers on Continuous Professional Development (CPD) programmes delivered in blended learning settings. The findings suggest that teaching presence and cognitive presence have themselves 'become social'. The research points to social presence as a major lever for engagement, sense-making and peer support. Based on the patterns identified in the study, this article puts forward an adjustment to the Community of Inquiry framework, which shows social presence as more prominent within the teaching and cognitive constructs than the original version of the framework suggests

    Unpacking the concept of influencers: the moderating role of Social Media Influencers in service failure recovery strategies

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    Prior research has advanced several explanations for social media influencers’ (SMIs’) success in the burgeoning computer-mediated marketing environments but leaves one key topic unexplored: the moderating role of SMIs in service failure recovery strategies. This study adds to the literature by analysing the nature of influencer marketing from the credibility of source perspective to the congruence effects between SMIs’ and consumers’ perceptions, particularly on the mediating role of influencers on failure recovery processes. Building on actor–network theory, this study conceptualises four distinct pathways unifying SMIs’ efforts in the service failure recovery process. The emergent dual funnel model illustrates how the effortful processing of social media content, source credibility and message content moderate service failure severity and speed of recovery. The insights gained from our model contribute to research on the pivotal uniqueness of SMIs in service failure recovery processes and offer practical explanations of variations in the implementation of influencer marketing

    Sensitivity of mangrove range limits to climate variability

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    Aim: Correlative distribution models have been used to identify potential climatic controls of mangrove range limits, but there is still uncertainty about the relative importance of these factors across different regions. To provide insights into the strength of climatic control of different mangrove range limits, we tested whether temporal variability in mangrove abundance increases near range limits and whether this variability is correlated with climatic factors thought to control large scale mangrove distributions. Location: North and South America. Time period: 1984–2011. Major taxa studied: Avicennia germinans, Avicennia schuaeriana, Rhizophora mangle, Laguncularia racemosa. Methods: We characterized temporal variability in the enhanced vegetation index (EVI) at mangrove range limits using Landsat satellite imagery collected between 1984–2011. We characterized greening trends at each range limit, examined variability in EVI along latitudinal gradients near each range limit, and assessed correlations between changes in EVI and temperature and precipitation. Results: Spatial variability in mean EVI was generally correlated with temperature and precipitation, but the relationships were region specific. Greening trends were most pronounced at range limits in eastern North America. In these regions variability in EVI increased toward the range limit and was sensitive to climatic factors. In contrast, EVI at range limits on the Pacific coast of North America and both coasts of South America was relatively stable and less sensitive to climatic variability. Main conclusions: Our results suggest that range limits in eastern North America are strongly controlled by climate factors. Mangrove expansion in response to future warming is expected to be rapid in regions that are highly sensitive to climate variability (e.g. eastern North America), but the response in other range limits (e.g. South America) is likely to be more complex and modulated by additional factors such as dispersal limitation, habitat constraints, and/or changing climatic means rather than just extremes

    Structural abnormalities of the coronary arterial wall - in addition to luminal narrowing - Affect myocardial blood flow reserve

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    Multislice CT provides information on coronary luminal narrowing and on the structural abnormalities of the coronary arterial wall using densitometric analysis. We sought to investigate the effects of coronary luminal narrowing, structural abnormalities of the coronary arterial wall, and cardiovascular risk factors on regional and global myocardial blood flow (MBF) reserve. Methods: We studied 68 patients (mean age ± SD, 61 ± 10 y; 41 men, 27 women) with an intermediate probability of coronary artery disease. We measured the severity of coronary stenoses and the fibroadipose, fibromuscular, and calcium components of the coronary arterial wall by 64-row multislice CT coronary angiography. We also measured regional and global MBF reserve by PET using 13N-ammonia as a flow tracer at rest and after dipyridamole. Results: One or more significant coronary stenoses (≄50% luminal narrowing) was present in 32 patients (47%), and nonsignificant stenoses were present in 15 patients (22%). Regional MBF reserve was significantly different in the territories perfused by normal coronary arteries, nonsignificant coronary stenoses, and significant coronary stenoses (P < 0.001). Calcium content was higher in the coronary arteries with significant or nonsignificant stenoses (0.95% ± 1.08% and 0.73% ± 0.93%, respectively) than in those without stenoses (0.11% ± 0.38%, P < 0.001). Significant coronary stenosis (P = 0.047) and calcium content (P = 0.017) were the only independent determinants of impaired regional MBF reserve using multivariate analysis. At multiple logistic regression analysis, the Framingham risk score, an index of global cardiovascular risk burden, was the only significant determinant of global MBF reserve (P = 0.028). Conclusion: Coronary stenoses and coronary calcium content independently affect regional MBF reserve. Framingham risk score is the only significant determinant of global MBF reserve. Copyright © 2011 by the Society of Nuclear Medicine, Inc

    Do rebreathing manoeuvres for non-invasive measurement of cardiac output during maximum exercise test alter the main cardiopulmonary parameters?

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    Background: Inert gas rebreathing has been recently described as an emergent reliable non-invasive method for cardiac output determination during exercise, allowing a relevant improvement of cardiopulmonary exercise test clinical relevance. For cardiac output measurements by inert gas rebreathing, specific respiratory manoeuvres are needed which might affect pivotal cardiopulmonary exercise test parameters, such as exercise tolerance, oxygen uptake and ventilation vs carbon dioxide output (VE/VCO2) relationship slope. Method: We retrospectively analysed cardiopulmonary exercise testing of 181 heart failure patients who underwent both cardiopulmonary exercise testing and cardiopulmonary exercise test+cardiac output within two months (average 16 \ub1 15 days). All patients were in stable clinical conditions (New York Heart Association I\u2013III) and on optimal medical therapy. Results: The majority of patients were in New York Heart Association Class I and II (78.8%), with a mean left ventricular ejection fraction of 31 \ub1 10%. No difference was found between the two tests in oxygen uptake at peak exercise (1101 (interquartile range 870\u20131418) ml/min at cardiopulmonary exercise test vs 1103 (844\u20131389) at cardiopulmonary exercise test-cardiac output) and at anaerobic threshold. However, anaerobic threshold and peak heart rate, peak workload (75 (58\u2013101) watts and 64 (42\u201390), p < 0.01) and carbon dioxide output were significantly higher at cardiopulmonary exercise testing than at cardiopulmonary exercise test+cardiac output, whereas VE/VCO2 slope was higher at cardiopulmonary exercise test+cardiac output (30 (27\u201335) vs 33 (28\u201337), p < 0.01). Conclusion: The similar anaerobic threshold and peak oxygen uptake in the two tests with a lower peak workload and higher VE/VCO2 slope at cardiopulmonary exercise test+cardiac output suggest a higher respiratory work and consequent demand for respiratory muscle blood flow secondary to the ventilatory manoeuvres. Accordingly, VE/VCO2 slope and peak workload must be evaluated with caution during cardiopulmonary exercise test+cardiac output

    Student Satisfaction and Performance in an Online Teacher Certification Program

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    The article presents a study which demonstrates the effectiveness of an online post baccalaureate teacher certification program developed by a Wisconsin university. The case method approach employing multiple methods and multiple data sources were used to investigate the degree to which pre-service teachers were prepared to teach. It was concluded that the study supports online delivery as an effective means of teacher preparation, but it was limited in the number of students followed into their first year of teaching

    Dog skin parasite load, TLR-2, IL-10 and TNF-α expression and infectiousness

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    Visceral leishmaniosis is a zoonotic disease that is transmitted by Lutzomyia longipalpis sandflies. Dogs are the main peri-urban reservoir of the disease, and progression of canine leishmaniosis is dependent on the type of immune response elaborated against the parasite. Type 1 immunity is characterized by effective cellular response, with production of pro-inflammatory cytokines such as tumour necrosis factor alpha (TNF-α). In contrast, Type 2 immunity is predominantly humoral, associated with progression of the disease and mediated by anti-inflammatory cytokines such as interleukin 10 (IL-10). Although seemly important in the dynamics of leishmaniosis, other gene products such as toll-like receptor 2 (TRL-2) and inducible nitric oxide synthase (iNOS) exert unclear roles in the determination of the type of immune response. Given that the dog skin serves as a micro-environment for the multiplication of Leishmania spp., we investigated the parasite load and the expression of TLR-2, iNOS, IL-10 and TNF-α in the skin of 29 infected and 8 control dogs. We found that increased parasite load leads to upregulation of TLR-2, IL-10 and TNF-α, indicating that abundance of these transcripts is associated with infection. We also performed a xenodiagnosis to demonstrate that increased parasitism is a risk factor for infectiousness to sandflies
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