Investigating the relationship between tax revenues and tax ratios : an empirical research for selected OECD countries

Purpose: Effective tax rates can have dual effect in the economic policy of a country by maintaining the state revenues in sustainable levels providing a safe net for the economic development. If taxation struggles the economy, there should be a turning point were the results of high tax rates do not have the expected results on the state revenue. The parabolic relation of Laffer curve is tested on a data set of different OECD countries. Design/Approach/Methodology: Three different functions have been selected to test the Laffer curve starting from the fact that the relation of revenues with taxes should have a parabolic form, with the turning point to be the peak of the parabola. Findings: The findings suggest that there exists a peak point where taxation policy is not providing the expected revenues. Results suggest that this pattern is common in several countries with different taxation regimes. The effective tax rates are different between the countries. Countries are divided into clusters with the same effective tax rates. The relation of the tax revenue and taxation rates is adjusted with the tax moral of the country. Practical Implications: The results are compared with other possible forms of the relation of revenue and taxes with considerable importance.peer-reviewe

An Analysis of Critical Variables Affecting Working Capital in Infrastructure Projects

The research aims at exploring the critical variables that affect public works contractors’ working capital in the delivery of infrastructure projects. Effective financial management has long been recognized as the ‘lifeblood’ of construction contractors, especially during economic periods of recession. The main reason for insolvency in the built environment is the lack of working capital to support contractors’ site operations. Therefore, it is vital to accurately predict the project working capital requirements at the pre-tender stage and closely monitor project cash-flow during the physical production process. The proposed methodology entails the development of a cash-flow/ working capital calculation process based on spreadsheet modelling and the Gantt chart for the derivation of project disbursements S-curves, revenue step function curves, and maximum/net cash-flow profiles. The model is implemented to a recently delivered typical infrastructure project – the construction of a new peripheral highway reinforced concrete bridge – and a sensitivity analysis is conducted to reach useful conclusions concerning the significance in infrastructure working capital of the following variables examined: the retention percentage, the ‘front-end rate loading’ by the contractor, and the premium advance incentive by the owner. The lowest maximum working capital requirement results from the provision of an advance mobilization payment by the owner to the contractor at project start-up and the selection of the latest start times site work execution program. The herein presented study is expected to assist both researchers and practitioners operating within the public construction sector in decision-making towards more effective financial management of infrastructure projects.     Keywords: infrastructure projects, public works contractors, cash-flow management, working capital, Gantt chart, S-curv

Inflammation and Atherosclerosis

AbstractPurposeThe aim of this article is to discuss the role of inflammation in atherosclerosis.SummaryAn initial chemical, mechanical or immunological insult induces endothelial dysfunction. This triggers a cascade of inflammatory reactions, in which monocytes, macrophages, T lymphocytes and vascular smooth muscle cells participate. Leukocyte adhesion molecules, cytokines, growth factors and metalloproteinases participate in all stages of atherogenesis. Almost all of the traditional risk factors for atherosclerosis are associated with and participate in the inflammatory process. Many infectious agents, mainly Chlamydia pneumoniae, have been proposed as potential triggers of the cascade. The immune system has been implicated in plaque formation, through the activation of cellular and humoral immunity against innate or microbial heat shock protein 60. Methods of detection of systemic or local plaque inflammation have been developed and research is being conducted on the potential use of anti-inflammatory and antibiotic drugs in atherosclerosis

Pseudorapidity Distribution of Charged Particles in PbarP Collisions at root(s)= 630GeV

Using a silicon vertex detector, we measure the charged particle pseudorapidity distribution over the range 1.5 to 5.5 using data collected from PbarP collisions at root s = 630 GeV. With a data sample of 3 million events, we deduce a result with an overall normalization uncertainty of 5%, and typical bin to bin errors of a few percent. We compare our result to the measurement of UA5, and the distribution generated by the Lund Monte Carlo with default settings. This is only the second measurement at this level of precision, and only the second measurement for pseudorapidity greater than 3.Comment: 9 pages, 5 figures, LaTeX format. For ps file see http://hep1.physics.wayne.edu/harr/harr.html Submitted to Physics Letters

Carotid ultrasound findings as a predictor of long-term survival after abdominal aortic aneurysm repair: a 14-year prospective study

AbstractPurposeSeveral factors have been related to long-term survival after open abdominal aortic aneurysm (AAA) repair. The effect of carotid stenosis on outcome has not yet been examined. We performed an open prospective study to evaluate the prognostic significance of carotid stenosis on long-term survival of patients who had undergone elective operative repair of AAA.MethodsTwo hundred eight patients who underwent elective open AAA repair in our department between March 1987 and December 2001 were included in the study. All patients were evaluated preoperatively with color duplex ultrasound (US) scanning of the carotid arteries, and were followed up with clinical examination and carotid duplex US scanning 1 month after the operation and every 6 months thereafter. Median duration of follow-up was 50 months (range, 5-181 months). Cardiovascular morbidity and mortality, as well as all causes of mortality, were recorded and analyzed with regard to traditional risk factors and carotid US findings.ResultsTwenty-seven fatal and 46 nonfatal cardiovascular events were recorded. Both univariate and multivariate analysis showed that carotid stenosis 50% or greater and echolucent plaque were significantly associated with cardiovascular mortality and morbidity. Carotid stenosis was a stronger predictor of cardiovascular death than was ankle/brachial index. Age, hypercholesterolemia, coronary artery disease, and diabetes mellitus were also associated with higher mortality and morbidity from cardiovascular causes.ConclusionPatients electively operated on for AAA repair and with stenosis 50% or greater and echolucent plaque at duplex US scanning are at significantly increased risk for cardiovascular mortality and morbidity. Carotid US can therefore be used to select a subgroup of patients with AAA who might benefit from medical intervention, including antiplatelet and lipid-lowering agents

ΥΔΑΤΙΚΟ ΑΠΟΤΥΠΩΜΑ ΤΩΝ ΚΑΛΛΙΕΡΓΕΙΩΝ ΤΗΣ ΠΕΔΙΑΔΑΣ ΤΟΥ ΝΕΣΤΟΥ ΣΥΜΦΩΝΑ ΜΕ ΤΗ ΜΕΘΟΔΟΛΟΓΙΑ ΤΗΣ ΕΚΤΙΜΗΣΗΣ ΚΥΚΛΟΥ ΖΩΗΣ

Η αλόγιστη χρήση των υδατικών αποθεμάτων μιας περιοχής για την άρδευση καλλιεργειών μπορεί να οδηγήσει σε εξάντληση των πόρων της περιοχής και συνεπώς σε αναποτελεσματική άρδευση. Επίσης, η εφαρμογή της καλλιέργειας μπορεί να οδηγήσει και σε υποβάθμιση των υδατικών πόρων, λόγω μεταφοράς συστατικών των λιπασμάτων στα υδατικά σώματα. Η αλληλεξάρτηση αυτή καλλιέργειας και οικοσυστήματος καλλιεργούμενης περιοχής, μπορεί να αποτυπωθεί και ποσοτικοποιηθεί μέσω του Υδατικού Αποτυπώματος της καλλιέργειας, σύμφωνα με τις αρχές της Εκτίμησης Κύκλου Ζωής. Στην παρούσα εργασία προσδιορίζεται το Υδατικό Αποτύπωμα των καλλιεργειών της πεδιάδας του ποταμού Νέστου. Τα αποτελέσματα της μελέτης στοχεύουν στην αποτελεσματική άρδευση της περιοχής, μέσω της ολοκληρωμένης και βιώσιμης διαχείρισης των υδατικών της πόρων

GALA: an international multicentre randomised trial comparing general anaesthesia versus local anaesthesia for carotid surgery

Background: Patients who have severe narrowing at or near the origin of the internal carotid artery as a result of atherosclerosis have a high risk of ischaemic stroke ipsilateral to the arterial lesion. Previous trials have shown that carotid endarterectomy improves long-term outcomes, particularly when performed soon after a prior transient ischaemic attack or mild ischaemic stroke. However, complications may occur during or soon after surgery, the most serious of which is stroke, which can be fatal. It has been suggested that performing the operation under local anaesthesia, rather than general anaesthesia, may be safer. Therefore, a prospective, randomised trial of local versus general anaesthesia for carotid endarterectomy was proposed to determine whether type of anaesthesia influences peri-operative morbidity and mortality, quality of life and longer term outcome in terms of stroke-free survival. Methods/design: A two-arm, parallel group, multicentre randomised controlled trial with a recruitment target of 5000 patients. For entry into the study, in the opinion of the responsible clinician, the patient requiring an endarterectomy must be suitable for either local or general anaesthesia, and have no clear indication for either type. All patients with symptomatic or asymptomatic internal carotid stenosis for whom open surgery is advised are eligible. There is no upper age limit. Exclusion criteria are: no informed consent; definite preference for local or general anaesthetic by the clinician or patient; patient unlikely to be able to co-operate with awake testing during local anaesthesia; patient requiring simultaneous bilateral carotid endarterectomy; carotid endarterectomy combined with another operation such as coronary bypass surgery; and, the patient has been randomised into the trial previously. Patients are randomised to local or general anaesthesia by the central trial office. The primary outcome is the proportion of patients alive, stroke free ( including retinal infarction) and without myocardial infarction 30 days post-surgery. Secondary outcomes include the proportion of patients alive and stroke free at one year; health related quality of life at 30 days; surgical adverse events, re-operation and re-admission rates; the relative cost of the two methods of anaesthesia; length of stay and intensive and high dependency bed occupancy

Procedural personas as critics for dungeon generation

This paper introduces a constrained optimization method which uses procedural personas to evaluate the playability and quality of evolved dungeon levels. Procedural personas represent archetypical player behaviors, and their controllers have been evolved to maximize a specific utility which drives their decisions. A “baseline” persona evaluates whether a level is playable by testing if it can survive in a worst-case scenario of the playthrough. On the other hand, a Monster Killer persona or a Treasure Collector persona evaluates playable levels based on how many monsters it can kill or how many treasures it can collect, respectively. Results show that the implemented two-population genetic algorithm discovers playable levels quickly and reliably, while the different personas affect the layout, difficulty level and tactical depth of the generated dungeons.The research was supported, in part, by the FP7 ICT project C2Learn (project no: 318480) and by the FP7 Marie Curie CIG project AutoGameDesign (project no: 630665).peer-reviewe