1,412 research outputs found

    Local Loop Unbundling in Europe: Experience, Prospects and Policy Challenges

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    This paper discusses the development of local loop unbundling in telecommunications markets throughout the European Union. It elaborates on the regulatory framework in Europe and provides an overview of recent experiences in Europe. Different types of unbundling, allowing for different types of entry and services provided by entrants, are discussed. This paper also explores the challenges for policy and regulation that arise because of unbundling and recent, related technological developments in the markets for fixed voice telephony and broadband internet access, particularly the emergence of packet-switched telephony such as VoIP.local-loop unbundling; VoIP; telecommunications; regulation

    Competition, Innovation and Intellectual Property Rights in Software Markets

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    This paper analyzes when it may be desirable for the government to stimulate open source software as a response to market failures in software markets. Our most important finding is that directly stimulating open source software, e.g. by acting as a lead customer, can improve dynamic efficiency if (i) there is a serious customer lock-in problem, while (ii) to develop the software, there is no need to purchase specific, complementary inputs at a substantial cost, and (iii) follow-on innovations are socially valuable but there are impediments to contractual agreements between developers that aim at realizing such innovations.software markets, intellectual property rights, open source software, public policy.

    Оценка деятельности профессиональных участников туристического рынка

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    Цель данной работы заключается в теоретическом обобщении и разработке сбалансированной системы показателей деятельности профессиональных участников туристического рынка и их оценке

    Implementation of an On-Demand Routing Protocol for Wireless Sensor Networks

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    We present our experiences in implementing and validating the on-demand EYES Source Routing protocol (ESR) in a real wireless sensor network (WSN) environment. ESR has a fast recovery mechanism relying on MAC layer feedback to overcome frequent network topology changes resulting from node mobility and unreliability. A geographically restricted directional flooding scheme reduces energy consumption in the route re-establishment. ESR is implemented in our WSN environment consisting of EYES sensor node prototypes using the Lightweight Medium Access Control protocol (LMAC) on top of the AmbientRT operating system. We describe the key design and implementation features of our protocol and report experiment results of ESR and Ad hoc On-demand Distance Vector protocol (AODV), a conventional routing protocol for ad hoc networks

    Cardiovascular disease biomarkers are associated with declining renal function in type 2 diabetes

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    Aims/hypothesis: We investigated whether biochemical cardiovascular risk factors and/or markers of subclinical cardiovascular disease were associated with the development of reduced renal function in people with type 2 diabetes. Methods: A cohort of 1066 Scottish men and women aged 60–74 years with type 2 diabetes from the Edinburgh Type 2 Diabetes Study were followed up for a median of 6.7 years. New-onset reduced renal function was defined as two eGFRs <60 ml−1 min−1 (1.73 m)−2 at least 3 months apart with a > 25% decline from baseline eGFR. Ankle brachial pressure index (ABI), N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity troponin T (hsTnT) were measured at baseline. Pulse wave velocity (PWV) and carotid intima media thickness were measured 1 year into follow-up. Data were analysed using Cox proportional hazards models. Results: A total of 119 participants developed reduced renal function during follow-up. ABI, PWV, NT-proBNP and hsTnT were all associated with onset of decline in renal function following adjustment for age and sex. These associations were attenuated after adjustment for additional diabetes renal disease risk factors (systolic BP, baseline eGFR, albumin:creatinine ratio and smoking pack-years), with the exception of hsTnT which remained independently associated (HR 1.51 [95% CI 1.22, 1.87]). Inclusion of hsTnT in a predictive model improved the continuous net reclassification index by 0.165 (0.008, 0.286). Conclusions/interpretation: Our findings demonstrate an association between hsTnT, a marker of subclinical cardiac ischaemia, and subsequent renal function decline. Further research is required to establish the predictive value of hsTnT and response to intervention

    Stapled coronary anastomosis with minimal intraluminal artifact: The S2 Anastomotic System in the off-pump porcine model

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    AbstractObjectiveA reliable, easy-to-use, 1-shot anastomotic device will significantly push the barrier for less invasive coronary bypass surgery. The current study was designed to test the safety, efficacy, and early patency of a novel distal anastomotic device.MethodsThe S2 Anastomotic System (iiTech BV, Amsterdam, The Netherlands) was used in 10 consecutive pigs (73 kg) on a mild antiplatelet regimen. In each animal, the device was used to create an internal thoracic artery to left anterior descending bypass on the beating heart. The anastomoses were evaluated intraoperatively (n = 10), at 2 days (n = 2), and at 5 weeks (n = 8) by functional flow measurements, postmortem angiography, and histomorphologic examination.ResultsIn all pigs, the S2Anastomic System rapidly created successful anastomoses at the first attempt (graft loading and coronary ischemia time: 1.2 ± 0.3 minutes and 3.0 ± 0.6 minutes) on target vessels of 1.6 to 2 mm inner diameter. There were no technical failures or anastomotic leaks requiring additional sutures. Both intraoperatively and at the time of death, ischemically induced peak hyperemic flow responses demonstrated widely patent bypasses, which were confirmed by postmortem angiography (FitzGibbon grade A, n = 10) and macroscopic evaluation (anastomotic orifice: 2 mm). Histomorphologic evaluation showed a normal healing response with negligible neointima covering the connector and limited streamlining repair tissue formation between the staple-like elements of the connector.ConclusionsThe S2 Anastomotic System consistently created automated, fast, and reliable internal thoracic to coronary artery anastomoses on the porcine beating heart with excellent graft patency and healing characteristics at the 5-week follow-up

    Significance of thromboxane A2 and prostaglandin I2 in acute necrotizing pancreatitis in rats

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    Plasma thromboxane concentrations were found to be significantly elevated in acute necrotizing pancreatitis in rats, whereas prostaglandin I2 levels were not. The significance of these alterations was investigated. Pancreatitis was induced by injecting 5% sodium taurocholate into the pancreatic duct. Iloprost (ZK 36374, a stable analog of prostaglandin I2, 25 ng/kg body weight) decreased the mortality rate from 100% to 50%. When treatment with iloprost was combined with simultaneous administration of either Sibelium (flunarizine R 14 950, 0.2 mg/kg body weight) or dazmegrel (UK 38 485, 50 mg/kg body weight) an additional decrease in the mortality rate was recorded. Dazmegrel is a selective thromboxane A2 synthetase inhibitor and flunarizine (a calcium entry blocker) also inhibits the effects of elevated thromboxane A2 levels. With flunarizine and iloprost the mortality rate was 40% (P<0.05); with dazmegrel and iloprost it was 10% (P<0.01). The results of the present study suggest that thromboxane A2 and prostaglandin I2 play a role in the course of acute necrotizing pancreatitis

    Least-cost seed potato production in Ethiopia

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    Improved potato varieties can increase potato yields of smallholders, and thus contribute to food security improvement in Ethiopia. However, the uptake of these varieties by farmers is very limited so far and this is one of the causes of insufficient seed quality in the seed potato system in Ethiopia. The low uptake may be related to the high costs of recommended production methods for these varieties. The objective of this study was to formulate least-cost seed potato production methods for farmers in Ethiopia. The paper used integer linear programming to determine these least-cost seed potato production methods, using published data on the perceived contributions to seed tuber yield and quality of different cultivation and post-harvest management options, and calculated seed potato production cost data for the different options. For the potato-growing districts Jeldu and Welmera, several seed potato production methods were formulated from which farmers can choose an affordable method that will enable them to produce seed potato with reasonable yield and quality levels. Results showed that yield and quality levels could be simultaneously improved at relatively low extra costs, for example, by applying recommended fertilizer rate combined with two fungicide applications. In both districts, most methods were robust to 50% increases in the rental values of land, prices of seed, wage rates, and prices of agrochemicals. Findings can be used by potato development practitioners to advise farmers on the adoption of seed potato technologies that are compatible with their financial resources

    Local Loop Unbundling in Europe: Experience, Prospects and Policy Challenges

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    This paper discusses the development of local loop unbundling in telecommunications markets throughout the European Union. It elaborates on the regulatory framework in Europe and provides an overview of recent experiences in Europe. Different types of unbundling, allowing for different types of entry and services provided by entrants, are discussed. This paper also explores the challenges for policy and regulation that arise because of unbundling and recent, related technological developments in the markets for fixed voice telephony and broadband internet access, particularly the emergence of packet-switched telephony such as VoIP

    Improving seed potato quality in Ethiopia: a value chain perspective

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    In Ethiopia, use of low-quality seed potatoes by the majority of potato growers is associated with underdevelopment of the seed potato value chains. Three seed potato systems are present in Ethiopia: the informal seed system, the alternative seed system and the formal seed system. This chapter analyses the performance of seed potato value chains with respect to their ability to supply quality seed tubers to seed potato systems, by using the chain performance drivers enabling environment, technology, market structure, chain coordination, farm management, and inputs. Information obtained from literature review, secondary data and key informants’ interviews were used for the analysis. In the informal seed system, seed potato value chains suffered from a poor enabling environment such as a low quality technical support and lack of a seed quality control system; use of sub-optimal storage and transportation technologies, sub-optimal farm management practices; and little use of inputs. In the alternative seed system, main constraints were the lack of a seed potato quality control system, poor farm management practices, little use of inputs by seed potato growers, and a distorted seed potato market that resulted from involvement of institutional buyers. Chains in the formal seed potato system were characterised by little involvement of the private and public sectors in the production and supply of seed potatoes. Based on the analysis, improvement options for the three seed systems were identified
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