2,975 research outputs found

    Indolylarylsulfones, a fascinating story of highly potent human immunodeficiency virus type 1 non-nucleoside reverse transcriptase inhibitors

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    Indolylarylsulfones are a potent class of human immunodeficiency virus type 1 non-nucleoside reverse transcriptase inhibitors. In this review, the structure activity relationship (SAR) studies to improve the profile of sulfone L-737,126 discovered by Merck AG have been analysed with focus on introduction of the 3',5'-dimethyl groups at the 3-phenylsulfonyl moiety, the 2-hydroxyethyl tail at the indole-2-carboxamide nitrogen, coupling of the carboxamide nitrogen with one or two glycinamide and alaninamide units, a fluorine atom at position 4 of the indole ring and correlation between configuration of the asymmetric centre and linker length. IAS derivatives look like promising drug candidates for the treatment of AIDS and related infections in combination with other antiretroviral agents

    A practical approach to cosmological perturbations in modified gravity

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    The next generation of large scale surveys will not only measure cosmological parameters within the framework of General Relativity, but will also allow for precision tests of the framework itself. At the order of linear perturbations, departures from the growth in the LCDM model can be quantified in terms of two functions of time and Fourier number k. We argue that in local theories of gravity, in the quasi-static approximation, these functions must be ratios of polynomials in k, with the numerator of one function being equal to the denominator of the other. Moreover, the polynomials are even and of second degree in practically all viable models considered today. This means that, without significant loss of generality, one can use data to constraint only five functions of a single variable, instead of two functions of two variables. Furthermore, since the five functions are expected to be slowly varying, one can fit them to data in a non-parametric way with the aid of an explicit smoothness prior. We discuss practical application of this parametrization to forecasts and fits.Comment: 9 pages, v2: matching the published versio

    Fishing Across the Centuries: What Prospects for the Venice Lagoon?

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    Fishing has always been an important activity for those Venetians who live near the Lagoon, and it still enjoys an important economic and social role in the region. Over the last few years, however, the fishing industry has been subject to a profound transformation both in the reduction of the variety and the abundance of the species found in the lagoon, and in the change from a complex and well-structured type of activity to one which has become monospecialist, that is based principally on the fishing of the bivalve Tapes philippinarum (Adam & Reeve). The widespread diffusion of this bivalve and its considerable commercial value have resulted in an increased harvest, initially carried out by hand but now by more sophisticated methods which are capable of obtaining much higher yields. The social, economic and environmental problems resulting from this automated fishing have stimulated research into alternative strategies to manage the alieutic resources of the lagoon which will allow fishing to become a sustainable activity without inflicting long-term environmental damage. This present work will try and prepare the foundations for a system of eco-compatible management, based on an analysis of the functioning of the lagoon’s eco-system, defined as a paralic model, the observation of the traditional forms of fishing practiced over the centuries, a technical analysis of the present typology of lagoon fishing (fishing with fyke nets, “vallicoltura” and fishing of fish fry for rearing, clam fishing (Tapes philippinarum), mussel culture) with particular reference to the species fished, the distribution of the activity throughout the year and the technology employed, to the productivity of the various fishing methods.Venice Lagoon, Fyke nets, Clam Fishing management, Fish Farming

    Internal DLA on cylinder graphs: fluctuations and mixing

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    We use coupling ideas introduced in [13] to show that an IDLA process on a cylinder graph G × Z forgets a typical initial profile in O(N√τN (logN)2) steps for large N, where N is the size of the base graph G, and τN is the total variation mixing time of a simple random walk on G. The main new ingredient is a maximal fluctuations bound for IDLA on G × Z which only relies on the mixing properties of the base graph G and the Abelian property

    Effect of Cover Crops on Nitrogen Uptake, Soil Water Content and Biomass Production in a Short Rotation Poplar Plantation

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    The agricultural production of biomass for energy-giving uses is attracting increasing interest particularly in relation to the possibility of reducing the use of fossil fuels and thereby limiting the emission of greenhouse gases. However one of the barriers to wider development of biomass energy sources is the lack of information about the environmental impacts on the landscape of increasing production of biomass crops. In the first growth phases as in the subsequent harvesting stages, the risks of erosion can become considerable due to the absence of any sort of protective canopy. In this case resorting to the use of cover crops can represent a useful agronomic measure since it provides and maintains a suitable ground covering, above all in the winter months when leaf fall exposes the soil to rain action. The aim of the present work was to evaluate some of the agronomic effects of the planting of two different species of cover crops, the legume Trifolium subterraneum L. and the grass Lolium perenne L. in a closely spaced forestry plantation

    Enabling technology for maintenance in a smart factory: A literature review

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    Industry 4.0 technologies are transforming the factory in an "intelligent" or "smart" factory. In a such context, a greater efficiency and innovative relationship is basically demanded within the whole production chain, including suppliers, producers, and customers. To be more competitive, companies are becoming increasingly aware that maintenance plays a key role during the digital transformation from the perspective of both technology and management. In this work, we perform a literature review of published cases to investigate how maintenance is changing through technologies of Industry 4.0 currently used in maintenance. We found 34 papers in literature involved in analyzing relations between maintenance and Industry 4.0 technology. The analysis of such studies let us to establish the current technology state-of-art and identify the most suited technology that today is employed in maintenance tasks. In particular Industrial Internet of Things and Cloud Computing are more common in the analyzed studies, confirming how these concepts and technologies are at the basis of Industry 4.0

    Near real-time routine for volcano monitoring using infrared satellite data

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    An Advanced Very-High-Resolution Radiometer (AVHRR) routine for hotspot detection and effusion rate estimation (AVHotRR) using AVHRR infrared space-borne images is presented here for the monitoring of active lava flow. AVHotRR uses directly broadcast National Oceanic and Atmospheric Administration (NOAA)-AVHRR remotely sensed data. The 2006 summit eruption of Mount Etna provided the opportunity to test the products generated by AVHotRR for monitoring purposes. Low spatial and high temporal resolution products can also be used as inputs of flow models to drive numerical simulations of lava-flow paths and thus to provide quantitative hazard assessment and volcanic risk mitigation

    Stroke in Patients with Schistosomiasis: Review of Cases in Literature

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    Introduction. Cerebral vascular comorbidities may occur in patients with schistosomiasis, as described in case reports. Aim and Methods. We have summarized general clinical and neurological features in patients with stroke associated with schistosomiasis, through a review of case reports in the literature. Investigation Outcomes. A total of eight case reports were retrieved. The mean age of patients was 36.42 +/- 16.7 (19 to 56 years), four females, three males, and one anonymous sex. Eosinophilia was the most frequent feature at presentation, followed by cardiac abnormalities, confusion, fever, ataxia, hemiplegia, headache, urticaria, dysphasia, and memory impairment. Patients usually present with watershed infarction or intracranial vasculitis. In one case, extracranial carotid arteries presented with inflammation and stenosis. The patient's serology was positive on admission in five cases. Full neurological recovery was reported in three cases, and partial improvement in another three. In two cases, information on neurological outcomes was incomplete. Stroke in schistosomiasis can be caused by haemodynamic impairment, direct lesion to the arterial wall, vasa vasorum obliterative endarteritis, contiguity with a focus of inflamed tissue, or inflammatory intimal damage. Schistosomiasis needs to be included in the differential diagnosis of stroke in people living or coming back from endemic areas. Conclusions. Further studies addressing the noncommunicable comorbidity issues related to this condition are needed

    Un modello semplificato per la previsione dell'incremento di pressione interstiziale indotto da carichi ciclici

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    Le procedure che consentono la valutazione dell’incremento di pressione interstiziale indotto da azioni sismiche in terreni sabbiosi saturi si basano, tipicamente, sui risultati di prove cicliche di laboratorio a tensione o deformazione controllata. In tali procedure la storia di carico irregolare a cui ù sottoposto in terreno in sito deve essere semplificata con una azione equivalente tale che produca, su provini di terreno sottoposti a prove cicliche di laboratorio, lo stesso incremento delle pressioni interstiziali atteso nel sito. In alternativa, nel caso di propagazione monodimensionale, ù possibile utilizzare un unico parametro, detto ‘parametro di danno’, per modellare gli incrementi di pressione interstiziale misurati in laboratorio. Questo parametro consente di applicare direttamente i risultati di laboratorio per predire l’incremento di pressione interstiziale generato in sito da storie irregolari di tensione o deformazione dovute all’azione sismica. Tale procedura, per la sua semplicità di applicazione, consente di effettuare analisi della risposta dinamica di depositi sabbiosi saturi senza adottare sofisticati modelli costitutivi del terreno e pertanto si presta all’implementazione in codici di calcolo che operano nel dominio del tempo
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