79 research outputs found

    An Economic Model of International Gas Pipeline Routings to the Turkish Market: Numerical Results for an Uncertain Future

    Get PDF
    This paper presents a dynamic investment model of the international gas pipeline routings to the Turkish market. The model was developed by IIASA's Dynamic Systems Project (DYN) and Environmentally Compatible Energy Strategies Project (ECS) in 2000. To allow for user-friendly modeling, a professional software package "Investments in Gas Pipelines Optimization of Returns" (IGOR) was developed which can also be used as a basis for models for related problems. Input data originated from various sources, in particular IIASA's MESSAGE model. The paper analyzes model results under a wide range of future outcomes and includes comprehensive sensitivity analyses. The returns for five potential gas pipeline projects were analyzed for a wide range of values for the price elasticity of gas demand, GDP elasticity of gas demand and discount rates. The numerical results allow conclusions about gas price developments and optimal gas supply policies relative to the market parameters

    A Game-Dynamic Model of Gas Transportation Routes and Its Application to the Turkish Gas Market [Updated November 2003]

    Get PDF
    The purpose of this paper is to study an optimal structure of a system of international gas pipelines competing for a gas market. We develop a game-dynamic model of the operation of several interacting gas pipeline projects with project owners acting as players in the game. The model treats the projects' commercialization times major players' controls. Current quantities of gas supply are modeled as approximations of Nash equilibrium points in instantaneous "gas supply games", in which each player maximizes his/her current net profit due to the sales of gas. We use the model to analyze the Turkish gas market, on which gas routes originating from Russia, Turkmenistan and Iran are competing. The analysis is carried out in three steps. At step 1, we model the operation of the pipelines as planned and estimate the associated profits. At step 2, we optimize individual projects, with respect to their profits, assuming that the other pipelines operate as planned. At step 3, we find numerical Nash equilibrium commercialization policies for the entire group of the pipelines. The simulations show the degrees to which the planned regimes are not optimal compared to the Nash equilibrium ones. Another observation is that in equilibrium regimes the pipelines are not always being run at their full capacities, which implies that the proposed pipeline capacities might not be optimal. The simulation results turn out to be moderately sensitive to changes in the discount rate and highly sensitive to changes in the price elasticity of gas demand

    Sharp inequalities of Bienaymé–Chebyshev and Gauß type for possibly asymmetric intervals around the mean

    Get PDF
    Sharp upper bounds are proved for the probability that a standardized random variable takes on a value outside a possibly asymmetric interval around 0. Six classes of distributions for the random variable are considered, namely the general class of ‘distributions’, the class of ‘symmetric distributions’, of ‘concave distributions’, of ‘unimodal distributions’, of ‘unimodal distributions with coinciding mode and mean’, and of ‘symmetric unimodal distributions’. In this way, results by Gauß (Commentationes Societatis Regiae Scientiarum Gottingensis Recentiores 5:1–58, 1823), Bienaymé (C R Hebd Séance Acad Sci Paris 37:309–24, 1853), Bienaymé (C R Hebd Séance Acad Sci Paris 37:309–24, 1853), Chebyshev (Journal de mathématiques pures et appliqués (2) 12:177–184, 1867), and Cantelli (Atti del Congresso Internazionale dei Matematici 6:47–59, 1928) are generalized. For some of the known inequalities, such as the Gauß inequality, an alternative proof is given

    Treatment of extra-articular proximal and middle phalangeal fractures of the hand: a systematic review

    Get PDF
    The aim of the study was to systematically review the patient reported and functional outcomes of treatment for extra-articular proximal or middle phalangeal fractures of the hand in order to determine the best treatment options. The review methodology was registered with PROSPERO. A systematic literature search was conducted in electronic bibliographic databases. Two independent reviewers performed screening and data extraction. The evaluation of quality of the included studies was performed using the Structured Effectiveness Quality Evaluation scale. The initial search yielded 2354 studies. The full text manuscripts of 79 studies were evaluated of which 16 studies met the inclusion criteria. In total, 513 extra-articular proximal and middle phalangeal fractures of the hand were included of which 118 (23%) were treated non-operatively, 188 (37%) were treated by closed reduction internal fixation (CRIF) and 207 (40%) by open reduction internal fixation. It can be recommended that closed displaced extra-articular phalangeal fractures can be treated non-operatively, even fractures with an oblique or complex pattern, provided that closed reduction is possible and maintained. Conservative treatment is preferably performed with a cast/brace allowing free mobilization of the wrist. No definite conclusion could be drawn upon whether closed reduction with extra-articular K-wire pinning or transarticular pinning is superior; however, it might be suggested that extra-articular K-wire pinning is favoured. When open reduction is necessary for oblique or spiral extra-articular fractures, lag screw fixation is preferable to plate and screw fixation. But, similar recovery and functional results are achieved with transversally inserted K-wires compared to lag screw fixation. Type of study/level of evidence: therapeutic III

    Improvement of Cardiac Function After Roux-en-Y Gastric Bypass in Morbidly Obese Patients Without Cardiac History Measured by Cardiac MRI

    Get PDF
    Purpose: Metabolic syndrome in patients with morbid obesity causes a higher cardiovascular morbidity, eventually leading to left ventricular hypertrophy and decreased left ventricular ejection fraction (LVEF). Roux-en-Y gastric bypass (RYGB) is considered the gold standard modality for treatment of morbid obesity and might even lead to improved cardiac function. Our objective is to investigate whether cardiac function in patients with morbid obesity improves after RYGB. Materials and Methods: In this single center pilot study, 15 patients with an uneventful cardiac history who underwent RYGB were included from May 2015 to March 2016. Cardiac function was measured by cardiac magnetic resonance imaging (CMRI), performed preoperatively and 3, 6, and 12 months postoperative. LVEF and myocardial mass and cardiac output were measured. Results: A total of 13 patients without decreased LVEF preoperative completed follow-up (mean age 37, 48.0 ± 8.8). There was a significant decrease of cardiac output 12 months postoperative (8.3 ± 1.8 preoperative vs. 6.8 ± 1.8 after 12 months, P = 0.001). Average myocardial mass declined by 15.2% (P < 0.001). After correction for body surface area (BSA), this appeared to be non-significant (P = 0.36). There was a significant improvement of LVEF/BSA at 6 and 12 months postoperative (26.2 ± 4.1 preoperative vs. 28.4 ± 3.4 and 29.2 ± 3.6 respectively, both P = 0.002). Additionally, there was a significant improvement of stroke volume/BSA 12 months after surgery (45.8 ± 8.0 vs. 51.9 ± 10.7, P = 0.033). Conclusion: RYGB in patients with morbid obesity with uneventful history of cardiac disease leads to improvement of cardiac function

    Identification and nomenclature of the genus Penicillium

    Get PDF
    AbstractPenicillium is a diverse genus occurring worldwide and its species play important roles as decomposers of organic materials and cause destructive rots in the food industry where they produce a wide range of mycotoxins. Other species are considered enzyme factories or are common indoor air allergens. Although DNA sequences are essential for robust identification of Penicillium species, there is currently no comprehensive, verified reference database for the genus. To coincide with the move to one fungus one name in the International Code of Nomenclature for algae, fungi and plants, the generic concept of Penicillium was re-defined to accommodate species from other genera, such as Chromocleista, Eladia, Eupenicillium, Torulomyces and Thysanophora, which together comprise a large monophyletic clade. As a result of this, and the many new species described in recent years, it was necessary to update the list of accepted species in Penicillium. The genus currently contains 354 accepted species, including new combinations for Aspergillus crystallinus, A. malodoratus and A. paradoxus, which belong to Penicillium section Paradoxa. To add to the taxonomic value of the list, we also provide information on each accepted species MycoBank number, living ex-type strains and provide GenBank accession numbers to ITS, β-tubulin, calmodulin and RPB2 sequences, thereby supplying a verified set of sequences for each species of the genus. In addition to the nomenclatural list, we recommend a standard working method for species descriptions and identifications to be adopted by laboratories working on this genus

    Phylogeny, identification and nomenclature of the genus Aspergillus

    Get PDF
    AbstractAspergillus comprises a diverse group of species based on morphological, physiological and phylogenetic characters, which significantly impact biotechnology, food production, indoor environments and human health. Aspergillus was traditionally associated with nine teleomorph genera, but phylogenetic data suggest that together with genera such as Polypaecilum, Phialosimplex, Dichotomomyces and Cristaspora, Aspergillus forms a monophyletic clade closely related to Penicillium. Changes in the International Code of Nomenclature for algae, fungi and plants resulted in the move to one name per species, meaning that a decision had to be made whether to keep Aspergillus as one big genus or to split it into several smaller genera. The International Commission of Penicillium and Aspergillus decided to keep Aspergillus instead of using smaller genera. In this paper, we present the arguments for this decision. We introduce new combinations for accepted species presently lacking an Aspergillus name and provide an updated accepted species list for the genus, now containing 339 species. To add to the scientific value of the list, we include information about living ex-type culture collection numbers and GenBank accession numbers for available representative ITS, calmodulin, β-tubulin and RPB2 sequences. In addition, we recommend a standard working technique for Aspergillus and propose calmodulin as a secondary identification marker

    Subclinical cardiac dysfunction in obesity patients is linked to autonomic dysfunction: findings from the CARDIOBESE study

    Get PDF
    Aims: Obesity doubles the lifetime risk of developing heart failure. Current knowledge on the role of obesity in causing cardiac dysfunction is insufficient for optimal risk stratification. The aim of this study was first to estimate the prevalence of subclinical cardiac dysfunction in obesity patients and second to investigate the underlying pathophysiology. Methods and results: The CARDIOBESE study is a cross-sectional multicentre study of 100 obesity patients [body mass index (BMI) ≥ 35 kg/m2] without known cardiovascular disease and 50 age-matched and gender-matched non-obese controls (BMI ≤ 30 kg/m2). Echocardiography was performed, blood samples were collected, and a Holter monitor was affixed. Fifty-nine obesity patients [48 (42–50) years, 70% female] showed subclinical cardiac dysfunction: 57 patients had decreased global longitudinal strain (GLS), and two patients with normal GLS had either diastolic dysfunction or increased brain natriuretic peptide (BNP). Only one non-obese control had diastolic dysfunction, and none had another sign of cardiac dysfunction. Multivariable logistic analysis identified male gender and standard deviation of all NN intervals (SDNN) index, which is a measure of autonomic dysfunction, as independent significant risk factors for subclinical cardiac dysfunction in obesity patients. Conclusions: There was a high prevalence (61%) of subclinical cardiac dysfunction in obesity patients without known cardiovascular disease, which appeared to be best identified by GLS. Subclinical cardiac dysfunction in obesity was linked to autonomic dysfunction and male gender, and not to the presence of traditional cardiac risk factors, increased C-reactive protein, increased BNP, increased high-sensitivity troponin I, or increased left ventricular mass

    Treatment of extra-articular proximal and middle phalangeal fractures of the hand: a systematic review

    Get PDF
    The aim of the study was to systematically review the patient reported and functional outcomes of treatment for extra-articular proximal or middle phalangeal fractures of the hand in order to determine the best treatment options. The review methodology was registered with PROSPERO. A systematic literature search was conducted in electronic bibliographic databases. Two independent reviewers performed screening and data extraction. The evaluation of quality of the included studies was performed using the Structured Effectiveness Quality Evaluation scale. The initial search yielded 2354 studies. The full text manuscripts of 79 studies were evaluated of which 16 studies met the inclusion criteria. In total, 513 extra-articular proximal and middle phalangeal fractures of the hand were included of which 118 (23%) were treated non-operatively, 188 (37%) were treated by closed reduction internal fixation (CRIF) and 207 (40%) by open reduction internal fixation. It can be recommended that closed displaced extra-articular phalangeal fractures can be treated non-operatively, even fractures with an oblique or complex pattern, provided that closed reduction is possible and maintained. Conservative treatment is preferably performed with a cast/brace allowing free mobilization of the wrist. No definite conclusion could be drawn upon whether closed reduction with extra-articular K-wire pinning or transarticular pinning is superior; however, it might be suggested that extra-articular K-wire pinning is favoured. When open reduction is necessary for oblique or spiral extra-articular fractures, lag screw fixation is preferable to plate and screw fixation. But, similar recovery and functional results are achieved with transversally inserted K-wires compared to lag screw fixation. Type of study/level of evidence: therapeutic III
    • …
    corecore