97 research outputs found

    Electron beam induced electronic transport in alkyl amine-intercalated VOx nanotubes

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    The electron beam induced electronic transport in primary alkyl amine-intercalated V2O5 nanotubes is investigated where the organic amine molecules are employed as molecular conductive wires to an aminosilanized substrate surface and contacted to Au interdigitated electrode contacts. The results demonstrate that the high conductivity of the nanotubes is related to the non-resonant tunnelling through the amine molecules and a reduced polaron hopping conduction through the vanadium oxide itself. Both nanotube networks and individual nanotubes exhibit similarly high conductivities where the minority carrier transport is bias dependent and nanotube diameter invariant

    Mathematical rainfall model for hydrographic demarcation of Manabi (Ecuador)

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    To determine the average annual rainfall at a specific site in a basin, it is necessary to count with rainfall information in the study area and topographic information. Counting with base information, is comes to the filling of them data missing with the help of any of them methods statistical existing for the effect. Thiessen polygons are built. Based on this procedure, may be elaborated isohyet or curves of equal rainfall, that are an input that can help also to estimate of precipitation in a specific geographical site. Here is a methodology that allows creating with the help of geographic information systems (GIS), a mathematical model to estimate very accurately the values of rainfall based only on the geographical coordinates. To achieve this objective, the basins of the Hydrographic Demarcation of Manabí have been chosen to develop the indicated mathematical model, which can be applied to other basins in the world.Keywords: multiple regression; mathematical model; GIS; Hydrology; rainfall

    Regulatory Framework for Renewable Energy Sources in Ecuador Case Study Province of Manabi

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    The purpose of the research is to expose the nature that, in matters of law and social policy, justifies promoting the elaboration and adoption of a regulatory framework that favors the use of renewable energy sources, for the generation of electricity through case analysis in the Province of Manabí. For the accomplishment of the research study has taken into account a brief theoretical analysis on the fundamentals of the regulatory doctrine, where it exposes the conceptual framework of the law and its necessity for the good development of the social relations that derive from the use of the Renewable sources of energy. A study was carried out of the specific regulatory work carried out at the International level, in order to promote the adequate use of renewable energies, as well as a national study presenting an initial vision for the study and establishment of a specific regulatory framework for the case study of the province of Manabí, as well as a group of policies and support measures that could be adopted to promote the integrated use of renewable energy sources and their contribution to the national energy matrix

    Towards an intelligent wearable ankle robot for assistance to foot drop

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    A wearable ankle robot prototype for assistance to foot drop is presented in this work. This device is built with soft and hard materials and employs one inertial sensor. First, the ankle robot uses a high-level method, developed with a Bayesian formulation, for recognition of walking activities and gait periods. Second, a low-level method, with a proportional-integral-derivative controller (PID), controls the wearable device to operate in assistive and transparent modes. In an assistive mode, activated by the toe-off detection, the wearable device assists the human foot in dorsiflexion orientation to reduce the effect of foot drop abnormality. In a transparent mode, activated by the heel-contact detection, the robot device follows the movements performed by the human foot. The wearable prototype is validated with experiments, in simulation and real-time modes, for recognition of walking activity and control of assistive and transparent modes during walking. Experiments achieved 99.87% and 99.20% accuracies for recognition of walking activity and gait periods. Results also show the ability of the wearable robot to operate according to the gait period recognised during walking. Overall, this work offers a wearable robot prototype with the potential to assist the human foot during walking, which is important to allow subjects to recover their confidence and quality of life

    Biogeography of parasitic nematode communities in giant Galápagos tortoise: implications for conservation management

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    The Galápagos giant tortoise is an icon of the unique, endemic biodiversity of Galápagos, but little is known of its parasitic fauna. We assessed the diversity of parasitic nematode communities and their spatial distributions within four wild tortoise populations comprising three species across three Galápagos islands, and consider their implication for Galápagos tortoise conservation programmes. Coprological examinations revealed nematode eggs to be common, with more than 80% of tortoises infected within each wild population. Faecal samples from tortoises within captive breeding centres on Santa Cruz, Isabela and San Cristobal islands also were examined. Five different nematode egg types were identified: oxyuroid, ascarid, trichurid and two types of strongyle. Sequencing of the 18S small-subunit ribosomal RNA gene from adult nematodes passed with faeces identified novel sequences indicative of rhabditid and ascaridid species. In the wild, the composition of nematode communities varied according to tortoise species, which co-varied with island, but nematode diversity and abundance were reduced or altered in captive-reared animals. Evolutionary and ecological factors are likely responsible for the variation in nematode distributions in the wild. This possible species/island-parasite co-evolution has not been considered previously for Galápagos tortoises. We recommend that conservation efforts, such as the current Galápagos tortoise captive breeding/rearing and release programme, be managed with respect to parasite biogeography and host-parasite co-evolutionary processes in addition to the biogeography of the host

    Responsible, safe, and effective prescription of opioids for chronic non-cancer pain: American society of interventional pain physicians (ASIPP) guidelines

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    Background: Opioid use, abuse, and adverse consequences, including death, have escalated at an alarming rate since the 1990s. In an attempt to control opioid abuse, numerous regulations and guidelines for responsible opioid prescribing have been developed by various organizations. However, the US opioid epidemic is continuing and drug dose deaths tripled during 1999 to 2015. Recent data show a continuing increase in deaths due to natural and semisynthetic opioids, a decline in methadone deaths, and an explosive increase in the rates of deaths involving other opioids, specifically heroin and illicit synthetic fentanyl. Contrary to scientific evidence of efficacy and negative recommendations, a significant proportion of physicians and patients (92%) believe that opioids reduce pain and a smaller proportion (57%) report better quality of life. In preparation of the current guidelines, we have focused on the means to reduce the abuse and diversion of opioids without jeopardizing access for those patients suffering from non-cancer pain who have an appropriate medical indication for opioid use. Objectives: To provide guidance for the prescription of opioids for the management of chronic non-cancer pain, to develop a consistent philosophy among the many diverse groups with an interest in opioid use as to how appropriately prescribe opioids, to improve the treatment of chronic non-cancer pain and to reduce the likelihood of drug abuse and diversion. These guidelines are intended to provide a systematic and standardized approach to this complex and difficult arena of practice, while recognizing that every clinical situation is unique. Methods: The methodology utilized included the development of objectives and key questions. The methodology also utilized trustworthy standards, appropriate disclosures of conflicts of interest, as well as a panel of experts from various specialties and groups. The literature pertaining to opioid use, abuse, effectiveness, and adverse consequences was reviewed, with a best evidence synthesis of the available literature, and utilized grading for recommendation as described by the Agency for Healthcare Research and Quality (AHRQ)

    Modeling complex metabolic reactions, ecological systems, and financial and legal networks with MIANN models based on Markov-Wiener node descriptors

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    [Abstract] The use of numerical parameters in Complex Network analysis is expanding to new fields of application. At a molecular level, we can use them to describe the molecular structure of chemical entities, protein interactions, or metabolic networks. However, the applications are not restricted to the world of molecules and can be extended to the study of macroscopic nonliving systems, organisms, or even legal or social networks. On the other hand, the development of the field of Artificial Intelligence has led to the formulation of computational algorithms whose design is based on the structure and functioning of networks of biological neurons. These algorithms, called Artificial Neural Networks (ANNs), can be useful for the study of complex networks, since the numerical parameters that encode information of the network (for example centralities/node descriptors) can be used as inputs for the ANNs. The Wiener index (W) is a graph invariant widely used in chemoinformatics to quantify the molecular structure of drugs and to study complex networks. In this work, we explore for the first time the possibility of using Markov chains to calculate analogues of node distance numbers/W to describe complex networks from the point of view of their nodes. These parameters are called Markov-Wiener node descriptors of order kth (Wk). Please, note that these descriptors are not related to Markov-Wiener stochastic processes. Here, we calculated the Wk(i) values for a very high number of nodes (>100,000) in more than 100 different complex networks using the software MI-NODES. These networks were grouped according to the field of application. Molecular networks include the Metabolic Reaction Networks (MRNs) of 40 different organisms. In addition, we analyzed other biological and legal and social networks. These include the Interaction Web Database Biological Networks (IWDBNs), with 75 food webs or ecological systems and the Spanish Financial Law Network (SFLN). The calculated Wk(i) values were used as inputs for different ANNs in order to discriminate correct node connectivity patterns from incorrect random patterns. The MIANN models obtained present good values of Sensitivity/Specificity (%): MRNs (78/78), IWDBNs (90/88), and SFLN (86/84). These preliminary results are very promising from the point of view of a first exploratory study and suggest that the use of these models could be extended to the high-throughput re-evaluation of connectivity in known complex networks (collation)
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