622 research outputs found

    Wolbachia, doxycycline and macrocyclic lactones: New prospects in the treatment of canine heartworm disease

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    Abstract Melarsomine dihydrochloride (ImmiticideÂź, Merial) is the only approved adulticidal drug for the treatment of canine heartworm disease (HWD). However, in cases where arsenical therapy is not possible or is contraindicated, a monthly heartworm preventive along with doxycycline for a 4-week period, which targets the bacterial endosymbiont Wolbachia, might be considered. There are published reports on the efficacy of ivermectin and doxycycline in both experimentally and naturally infected dogs, but no data on the use of other macrocyclic lactones (MLs) with a similar treatment regime. Preliminary results of studies in dogs show that a topical formulation of moxidectin, the only ML currently registered as a microfilaricide, is also adulticidal when combined with doxycycline. It is not yet known if the efficacy of these combination therapies is due to pharmacokinetic synergism. A recent study showed that serum levels of doxycycline in dogs treated with the combination protocol were not statistically different compared to dogs treated with doxycycline alone. However, lungs from dogs treated with the combination therapy showed a marked reduction in T regulatory cells, indicating that treatment efficacy may be due to a heightened immune response against the parasite. Further studies are necessary to evaluate the long-term clinical outcome of combination protocols and to establish the most efficient treatment for HWD in dogs

    Novel TCAD Approach for the Investigation of Charge Transport in Thick Amorphous SiO2 Insulators

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    A TCAD approach for the investigation of charge transport in thick amorphous silicon dioxide is presented for the first time. Thick oxides are investigated representing the best candidates for integrated galvanic insulators in future power applications. The large electric fields, such devices experience and the preexisting defects in the amorphous material, give rise to a leakage current, which leads to degradation and failure. Hence, it is crucial to have a complete understanding of the main physical mechanisms responsible for the charge transport in amorphous silicon oxide. For this reason, metal-insulator-metal structures have been experimentally characterized at different high-field stress conditions and a TCAD approach has been implemented in order to gain insight into the microscopic physical mechanisms responsible for the leakage current. In particular, the role of charge injection at contacts and charge build-up due to trapping-detrapping mechanisms in the bulk of the oxide layer has been investigated and modeled to the purpose of understanding the oxide behavior under dc- and ac-stress conditions. Numerical simulations have been compared against experiments to quantitatively validate the proposed approach

    A gated oscillator clock and data recovery circuit for nanowatt wake-up and data receivers

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    This article presents a data-startable baseband logic featuring a gated oscillator clock and data recovery (GO-CDR) circuit for nanowatt wake-up and data receivers (WuRxs). At each data transition, the phase misalignment between the data coming from the analog front-end (AFE) and the clock is cleared by the GO-CDR circuit, thus allowing the reception of long data streams. Any free-running frequency mismatch between the GO and the bitrate does not limit the number of receivable bits, but only the maximum number of equal consecutive bits (Nm). To overcome this limitation, the proposed system includes a frequency calibration circuit, which reduces the frequency mismatch to ±0.5%, thus enabling the WuRx to be used with different encoding techniques up to Nm = 100. A full WuRx prototype, including an always-on clockless AFE operating in subthreshold, was fabricated with STMicroelectronics 90 nm BCD technology. The WuRx is supplied with 0.6 V, and the power consumption, excluding the calibration circuit, is 12.8 nW during the rest state and 17 nW at a 1 kbps data rate. With a 1 kbps On-Off Keying (OOK) modulated input and −35 dBm of input RF power after the input matching network (IMN), a 10^(−3) missed detection rate with a 0 bit error tolerance is measured, transmitting 63 bit packets with the Nm ranging from 1 to 63. The total sensitivity, including the estimated IMN gain at 100 MHz and 433 MHz, is −59.8 dBm and −52.3 dBm, respectively. In comparison with an ideal CDR, the degradation of the sensitivity due to the GO-CDR is 1.25 dBm. False alarm rate measurements lasting 24 h revealed zero overall false wake-ups

    Evaluating the effects of environmental regulations on a closed-loop supply chain network: a variational inequality approach

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    © 2017 Springer Science+Business Media, LLC Global climate change has encouraged international and regional adoption of pollution taxes and carbon emission reduction policies. Europe has taken the leadership in environmental regulations by introducing the European Union Emissions Trading System (EU-ETS) in 2005 and by promoting a set of policies destined to lower carbon emissions from energy, industrial, and transport sectors. These environmental policies have significantly affected the production choices of these European sectors. Considering this framework, the objective of this paper is to evaluate the effects of the application of environmental policies in a multitiered closed-loop supply chain network where raw material suppliers, manufacturers, consumers, and recovery centers operate. In particular, we assume that manufacturers are subject to the EU-ETS and a carbon tax is imposed on truck transport. In this way, the developed model captures carbon emission regulations, recycling, transportation and technological factors within a unified framework. In particular, it allows for evaluating the impacts of the considered environmental regulations on carbon emissions, product flows, and prices. The proposed model is optimized and solved by using the theory of variational inequalities. Our analysis shows that the combined application of the EU-ETS at the manufacturers’ tier and the carbon tax on truck transport implies additional costs for producers that reduce their good provisions. On the other side, this has a positive outcome for the environment since (Formula presented.) emissions reduce. Moreover, an increase of the efficiency level of the recycling process increments the availability of reusable raw material in the reverse supply chain. Finally, the distance between a couple of CLSC tiers plays a very important role. The lower is the distance covered by vehicles, the higher is the production of goods and the lower is the amount of (Formula presented.) emitted

    Dynamic Spatial Auction Market Models with General Cost Mappings

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    © 2016, Springer Science+Business Media New York. The deregulation of electricity markets in Europe has deeply changed the organization of this sector. Vertically integrated generating companies have been unbundled to create competition and to increase the competitiveness of electricity markets. Directive 96/92/EC was issued by the European Commission to liberalize electricity markets and to pave the way for the creation of the Internal Electricity Market. In particular, this Directive aimed at promoting the competition in the activities of electricity generation and wholesale through the creation of a “marketplace” and the maximization of transparency and efficiency. Competition in European day-ahead electricity markets has been established through auction markets where electricity producers and consumers offer/bid prices and volumes. This paper suggests a dynamic equilibrium model for a system of auction markets linked by transmission lines and subject to energy balance and transmission constraints, such as those characterizing restructured electricity markets. This model is treated as a system of variational inequalities with arbitrary monotone mappings. An inexact splitting type method is proposed to find its solution. Numerical experiments are conducted on the Italian day-ahead electricity market

    Dynamic Spatial Auction Market Models with General Cost Mappings

    Get PDF
    © 2016 Springer Science+Business Media New YorkThe deregulation of electricity markets in Europe has deeply changed the organization of this sector. Vertically integrated generating companies have been unbundled to create competition and to increase the competitiveness of electricity markets. Directive 96/92/EC was issued by the European Commission to liberalize electricity markets and to pave the way for the creation of the Internal Electricity Market. In particular, this Directive aimed at promoting the competition in the activities of electricity generation and wholesale through the creation of a “marketplace” and the maximization of transparency and efficiency. Competition in European day-ahead electricity markets has been established through auction markets where electricity producers and consumers offer/bid prices and volumes. This paper suggests a dynamic equilibrium model for a system of auction markets linked by transmission lines and subject to energy balance and transmission constraints, such as those characterizing restructured electricity markets. This model is treated as a system of variational inequalities with arbitrary monotone mappings. An inexact splitting type method is proposed to find its solution. Numerical experiments are conducted on the Italian day-ahead electricity market

    Decomposition method for oligopolistic competitive models with common environmental regulation

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    © 2017 Springer Science+Business Media New YorkGlobal climate change has encouraged international and regional adoption of environmental policies aiming at reducing the generation of greenhouse gas emissions. Europe has taken the leadership in environmental regulations by introducing the European-Union Emissions Trading System (EU-ETS) in 2005 and other policies to mitigate carbon emissions and increase the efficiency of production processes. These environmental policies have significantly affected the production choices of the European energy and industrial sectors. In this paper, we consider a market where a set of players (firms) produce different commodities under a common environmental regulation that limits their emissions. Due to these environmental restrictions, the problem is treated as a generalized non-cooperative game where players have joint (environmental) constraints caused by the common and compulsory emission regulation. The problem is to find a natural mechanism for attaining the corresponding generalized equilibrium state. We suggest a share allocation method, which yields a suitable decomposition type procedure and replaces the initial problem with a sequence of non-cooperative games on Cartesian product sets. We also show that its implementation can be simplified essentially after the application of a regularized penalty method. In the case study, we take inspiration from the EU-ETS and we introduce an environmental regulation that restricts the carbon emissions of firms representing the energy, cement, and steel sectors respectively in Germany, France, Italy, and Spain. Our results confirm the important role played by energy sector in reducing carbon emissions
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