1,359 research outputs found

    Logic and the axiom of choice

    Get PDF

    A method for reducing theatre contamination by exhaled anesthetic drugs

    Get PDF
    Over the past few years it has been shown by different investigators that gaseous anesthetics in the atmosphere of operating theatres are a potential danger to theatre personnel. For instance, these dangers include a greater incidence of fetal fatality in the wives of anesthetists, a higher incidence of lymphoid malignancies in anesthetists and hepatitis. Besides these harmful effects, there is the discomfort, reduced alertness and performance associated with prolonged periods of breathing in small concentrations of volatile anesthetics. A method or reducing gaseous contamination is described, mainly consisting in the venting of exhaled gases. The contamination was reduced remarkably so that even when ether was used nobody in the theatre noticed.peer-reviewe

    Intubation with polyvinyl chloride tubes in young children

    Get PDF
    A case report of a 2.5 year old girl is presented. The girl was admitted to Victoria General Hospital, Gozo, suffering from laryngotracheitis. When her situation got worse, as she started having repeated bouts of laryngeal obstruction with deep cyanosis, restoration of the airway was imperative and it was decided to intubate. The child was quieted down with Fluothane using a Schimmelbusch mask, oxygen being administered throughout. A polyvinyl chloride tube, size 00, was passed nasally and was guided through the glottis with ease; the whole procedure (i.e. anesthesia, intubation) taking less than 90 seconds. The child quickly regained consciousness, did not become restless and soon went into a restful sleep with good normal pulse. In this case study, intubation was meant as a life-saving effort, a technique which has proved remarkably effective and complication-free.peer-reviewe

    The Impact of Search Cost Reduction on Seasonality

    Get PDF
    This study explores how online booking affects seasonality, measured as the variation in hotel bed-places net occupancy rate between peak and off-peak periods. We first develop a formal model illustrating that, as a result of the reduction in search costs brought about by the internet, competitive pressure strengthens. This effect is stronger in the peak period than off-peak, thus leading to an increase in seasonality associated to online booking. We then test our finding in a sample of 18 countries over the 1997\u20132007 span; the empirical results support the notion that the use of the internet causes an increase in seasonality. A set of policy implications conclude the work

    Kleene Algebra with Converse

    Get PDF
    International audienceThe equational theory generated by all algebras of binary relations with operations of union, composition, converse and reflexive transitive closure was studied by Bernátsky, Bloom, Ésik, and Stefanescu in 1995. We reformulate some of their proofs in syntactic and elementary terms, and we provide a new algorithm to decide the corresponding theory. This algorithm is both simpler and more efficient; it relies on an alternative automata construction, that allows us to prove that the considered equational theory lies in the complexity class PSPACE. Specific regular languages appear at various places in the proofs. Those proofs were made tractable by considering appropriate automata recognising those languages, and exploiting symmetries in those automata

    Cleaved surface of i-AlPdMn quasicrystals: Influence of the local temperature elevation at the crack tip on the fracture surface roughness

    Get PDF
    Roughness of i-AlPdMn cleaved surfaces are presently analysed. From the atomic scale to 2-3 nm, they are shown to exhibit scaling properties hiding the cluster (0.45 nm) aperiodic structure. These properties are quantitatively similar to those observed on various disordered materials, albeit on other ranges of length scales. These properties are interpreted as the signature of damage mechanisms occurring within a 2-3 nm wide zone at the crack tip. The size of this process zone finds its origin in the local temperature elevation at the crack tip. For the very first time, this effect is reported to be responsible for a transition from a perfectly brittle behavior to a nanoductile one.Comment: 8 page

    On the Design of Constructively Aligned Educational Unit

    Get PDF
    Modern pedagogy is moving away from traditional transmissive approaches, and it is extensively embracing constructive theory of learning. A prominent practical embodiment of this paradigm shift is a method called Constructive Alignment (CA). This approach focuses on learners’ actions and starts from a clear communication of the Intended Learning Outcomes (ILOs) of the focal unit. ILOs are made of content, a context, and an Educational Goal Verb (EGV). According to the Bloom Taxonomy, the EGV is the core of an ILO and refers to the action the learners are expected to be able to master after completing the educational unit. The ILO is then aligned to the course activity using the EGV (i.e., EGVs are enacted through Teaching and Learning Activities (TLAs) and verified through Assessment Tasks (ATs)). Despite the ILO definition being extensively investigated and described, the extant literature has poorly explored how to devise suitable TLAs and ATs, lacking comprehensive contributions that identify and describe the different kinds of TLAs and ATs available to course designers. In view of the above gap, the authors searched and reviewed the literature (scientific papers (i.e., top-down, deductive approach)) and practices in higher education (university websites and blogs (i.e., bottom-up, inductive approach)) to identify all the possible sources of TLA and AT descriptions available. The results propose standardized templates that support the course design process, providing extensive descriptions of TLA and AT based on the best practices identified. The proposed templates include the core dimensions that proved to be suitable for designing traditional and remote-learning activities. Finally, the examples provided in the paper show how to use these templates on a few kinds of selected on-campus and digital TLAs and ATs from the educational units identified in the Erasmus+ MAESTRO project, which is based on Industry 4.0 technological enablers and their application in support of manufacturing sustainability

    Natural compounds for pediatric cancer treatment

    Get PDF
    There is a tremendous need in clinics to impair cancer progression through noninvasive therapeutic approaches. The use of natural compounds to achieve this is of importance to improve the quality of life of young patients during their treatments. This review will address the "status of the art" related to the potential of natural compounds that are undergoing investigation in combination with standard therapeutic protocols in preclinical and clinical studies and their importance for pediatric cancer treatment. The early studies of drug discovery of these natural compounds discussed here include the main targets, the cellular signaling pathways involved, and the potential modes of action. We also focus on some promising natural compounds that have shown excellent results in vitro and in vivo: Chebulagic acid, Apigenin, Norcantharidin, Saffron/Crocin, Parthenolide, Longikaurin E, Lupeol, Spongistatin 1, and Deoxy-variolin B. Additionally, we introduce the effects of several compounds from nutraceutical and functional foods, to underline their potential use as adjuvant therapies to improve therapeutic benefits. For this purpose, we have selected several compounds: Agaritine, Ganoderma and GL6 peptide, Diallyl trisulfide and Ajoene from garlic, Epigallocatechin gallate from green tea, Curcumin, Resveratrol, and Quercetin

    Vegetation outlines of two active rock glaciers with contrasting lithology

    Get PDF
    Rock glaciers are periglacial landforms consisting of coarse debris with interstitial ice or ice core, characterized by creeping due to ice deformation. These landforms are drawing the attention of plant ecologist as harsh habitats and potential refugia in the global change context. Our aim was to describe the vegetation outlines of two active rock glaciers of the Ortles-Cevedale Massif (Central Italian Alps) on different substrates (silicate and carbonate) and compare them with the neighboring stable slopes and scree slopes. Two hypotheses were tested: 1) rock glaciers differ from the surrounding landforms for the presence of cold-adapted plant communities; 2) rock glacier plant communities indicate similar microclimatic conditions in spite of the contrasting lithology. Data were collected by phytosociological method performing 80 relev\ue9s of 25 m\ub2. Plant communities were compared by a cluster analysis based on the presence/absence species matrix and species relative frequencies for each landform were calculated. The cluster analysis separated first for all the two sites; afterwards, the landforms were differently discerned each other depending on the site. Despite the remarkable floristic differences due to the substrate, the vegetation of both rock glaciers suggest a general adjustment to cold-moist microclimate and long-lasting snow cover, differentiating more or less evidently from the adjacent scree slopes and enhancing the survival of nival entities at the elevation of alpine grasslands
    • …
    corecore