154 research outputs found

    EFFICIENCY, PRODUCTIVITY AND OUTPUT GROWTH: AN INTER-REGIONAL ANALYSIS OF GREEK AGRICULTURE

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    Output growth decomposition of the Greek olive-oil sector under technical and allocative inefficiencies, economies of scale and technical change, is performed. The stochastic production frontier model is extended to panel data and FGLS estimation. Conventional inputs are main source of growth: TFP increased in slow rate during the study period.Crop Production/Industries, Industrial Organization,

    Measuring the Accountability of Advertising Expenses in the Presence of Sales Cost Inefficiency and Marketing Spillovers

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    This paper develops a tractable theoretical framework for analyzing the substitutability between different advertising media, the extent of marketing spillovers in the market, the allocative efficiency of advertising spending, and the sources of total advertising productivity and sales growth. Maintaining the separability assumption between sales and production technology, the proposed methodology relies on cost-function decomposition of total factor productivity and the duality between input distance and cost functions. Utilizing a flexible Translog advertising distance function, the methodology is applied to the advertising activity of meat processing firms in Greece during the period 1983-1997. Scale economies in advertising expenses turn out to be an important source of total advertising productivity changes in the Greek meat processing sector. Advertising spillovers are significant contributing to total advertising productivity observed. Our analysis also indicates that improvements in (technical and allocative) advertising efficiency are more important means of enhancing firm returns than improvements in advertising techniques.Advertising productivity, advertising direct distance function, media substitutability, processed meats industry, Greece

    Measuring the Accountability of Advertising Expenses in the Presence of Sales Cost Inefficiency and Marketing Spillovers

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    This paper develops a tractable theoretical framework for analyzing the substitutability between different advertising media, the extent of marketing spillovers in the market, the allocative efficiency of advertising spending, and the sources of total advertising productivity and sales growth. Maintaining the separability assumption between sales and production technology, the proposed methodology relies on cost-function decomposition of total factor productivity and the duality between input distance and cost functions. Utilizing a flexible Translog advertising distance function, the methodology is applied to the advertising activity of meat processing firms in Greece during the period 1983-1997. Scale economies in advertising expenses turn out to be an important source of total advertising productivity changes in the Greek meat processing sector. Advertising spillovers are significant contributing to total advertising productivity observed. Our analysis also indicates that improvements in (technical and allocative) advertising efficiency are more important means of enhancing firm returns than improvements in advertising techniques

    Spectrophotometric analysis of crown discoloration induced by MTA- and ZnOE-based sealers

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    Crown discoloration can be induced by root canal sealer remnants following root canal treatment. Objective: The aim of this study was to evaluate chromatic alterations in human tooth crowns induced by a Mineral Trioxide Aggregate-based sealer (MTA Fillapex®) and a commonly used ZnOE-based sealer (Roth-811). The tested null hypothesis was that the application of the materials did not induce clinically perceptible crown discoloration (Ho: CIE color difference Δ

    Dyslipidaemia of Obesity, Metabolic Syndrome and Type 2 Diabetes Mellitus: the Case for Residual Risk Reduction After Statin Treatment

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    Dyslipidaemia is frequently present in obesity, metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM). The predominant features of dyslipidaemia in these disorders include increased flux of free fatty acids (FFA), raised triglyceride (TG) and low high density lipoprotein cholesterol (HDL-C) levels, a predominance of small, dense (atherogenic) low density lipoprotein cholesterol (LDL) particles and raised apolipoprotein (apo) B values Posprandial hyperlipidaemia may also be present. Insulin resistance (IR) appears to play an important role in the pathogenesis of dyslipidaemia in obesity, MetS and T2DM. The cornerstone of treatment of this IR-related dyslipidaemia is lifestyle changes and in diabetic patients, tight glycaemic control. In addition to these measures, recent clinical trials showed benefit with statin treatment. Nevertheless, a substantial percentage of patients treated with statins still experience vascular events. This residual vascular risk needs to be addressed. This review summarizes the effects of hypolipidaemic drug combinations (including statins with cholesterol ester protein inhibitors, niacin, fibrates or fish oil, as well as fibrate-ezetimibe combination) on the residual vascular risk in patients with obesity, MetS or T2DM

    Dyslipidemia Induced by Drugs Used for the Prevention and Treatment of Vascular Diseases

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    Dyslipidemia is a major vascular risk factor. Interestingly, several agents used for the prevention and treatment of vascular diseases have an adverse effect on the lipid profile. In addition, agents belonging to the same class (e.g. beta blockers) can have significantly different actions on lipid levels. We summarize the effects of drugs used for the prevention and treatment of vascular diseases on the lipid profile. These effects should be considered when selecting a specific agent, particularly in high-risk patients

    Analysis of HIV-1 quasispecies sequences generated by High Throughput Sequencing (HTS) using HIVE

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    The high level of genetic variability of Human Immunodeficiency Virus type 1 (HIV-1) is caused by the low fidelity of its replication machinery. This leads to evolution of swarm-like viral populations often described as quasispecies. High throughput sequencing (HTS) technology provides higher resolution over Sanger sequencing, enabling detection of low frequency variant genomes. However, quasispecies analysis is still a challenge due to the systematic noise, introduced by HTS technology. This leads to the increase in type I errors (also known as false positives) and the underlying genetic diversity, which can lead to mathematically insolvable type II errors (also known as false negatives). We have developed a pipeline using the tools in the High-performance Integrated Virtual Environment (HIVE), an HTS platform designed for big data analysis and management, to analyze viral populations within each sample and identify their subtype classification and recombination patterns of recombinants. RNA was extracted from 70 plasma samples of chronic HIV-1 infected patients. The 3’ half genomes of HIV-1 were amplified using RT-PCR and PCR products were sequenced using Illumina MiSeq. The paired end reads for each sample were assembled using Geneious software and analyzed for presence of HIV-1 quasispecies using HIVE tools. Subtype analysis of 70 samples using Geneious software identified 17 A1s, 4 Bs, 30 Cs, 1 D, 6 CRF02_AG, and 12 unique recombinant forms (URFs). Additionally, we found up to 178 ambiguous bases in the consensus sequences from 41 viral samples (58.6%), suggesting the presence of viral subpopulations. However, Geneious could not determine the major viral populations in each sample. We analyzed the same HTS reads using the HIV-1 quasispecies analysis pipeline and found one predominant population in 11 samples (15.7 %), two to ten distinct populations in 45 samples (64.3%), 11-20 in 13 samples (18.16%), and 26 in one sample (1.4 %). Interestingly, two equally major viral populations that were not detected by Geneious were identified in five samples (7.1%) by HIVE. The HIV-1 quasispecies analysis pipeline is reliable and more sensitive in its ability to identify distinct viral populations and the recombination patterns not identified by the Geneious software

    The effect of antihypertensive drugs on arterial stiffness and central hemodynamics: Not all fingers are made the same

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    Arterial stiffness and central hemodynamics attract increasing scientific interest within the hypertensive community during the last decade. Accumulating evidence indicates that aortic stiffness is a strong and independent predictor of cardiovascular events and all-cause mortality in hypertensive patients, and its predictive value extends beyond traditional risk factors. The role of central hemodynamics and augmentation index (a marker of reflected waves), remains less established and requires further investigation. Several lines of evidence indicate that antihypertensive therapy results in significant reductions of pulse wave velocity and central hemodynamics. However, beta-blockers seem to be the only exception with significant within-class differences. Conventional beta-blockers, although equally effective in reducing pulse wave velocity, seem to be less beneficial on central hemodynamics and augmentation index than the other antihypertensive drug categories, whereas the newer vasodilating beta-blockers seem to share the benefits of the other antihypertensive drugs. In conclusion, aortic stiffness seems ready for ‘prime-time’ in the management of essential hypertension, while further research is needed for central hemodynamics and augmentation index
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