207 research outputs found

    Does timing of decisions in a mixed duopoly matter?

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    We determine the endogenous order of moves in a mixed pricesetting duopoly. In contrast to the existing literature on mixed oligopolies we establish the payo equivalence of the games with an exogenously given order of moves if the most plausible equilibrium is realized in the market. Hence, in this case it does not matter whether one becomes a leader or a follower. We also establish that replacing a private firm by a public firm in the standard Bertrand-Edgeworth game with capacity constraints increases social welfare and that a pure-strategy equilibrium always exists

    Secular evolution versus hierarchical merging: galaxy evolution along the Hubble sequence, in the field and rich environments

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    In the current galaxy formation scenarios, two physical phenomena are invoked to build disk galaxies: hierarchical mergers and more quiescent external gas accretion, coming from intergalactic filaments. Although both are thought to play a role, their relative importance is not known precisely. Here we consider the constraints on these scenarios brought by the observation-deduced star formation history on the one hand, and observed dynamics of galaxies on the other hand: the high frequency of bars and spirals, the high frequency of perturbations such as lopsidedness, warps, or polar rings. All these observations are not easily reproduced in simulations without important gas accretion. N-body simulations taking into account the mass exchange between stars and gas through star formation and feedback, can reproduce the data, only if galaxies double their mass in about 10 Gyr through gas accretion. Warped and polar ring systems are good tracers of this accretion, which occurs from cold gas which has not been virialised in the system's potential. The relative importance of these phenomena are compared between the field and rich clusters. The respective role of mergers and gas accretion vary considerably with environment.Comment: 18 pages, 8 figures, review paper to "Penetrating Bars through Masks of Cosmic Dust: the Hubble Tuning Fork Strikes a New Note", Pilanesberg, ed. D. Block et al., Kluwe

    Optical Magnetometry

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    Some of the most sensitive methods of measuring magnetic fields utilize interactions of resonant light with atomic vapor. Recent developments in this vibrant field are improving magnetometers in many traditional areas such as measurement of geomagnetic anomalies and magnetic fields in space, and are opening the door to new ones, including, dynamical measurements of bio-magnetic fields, detection of nuclear magnetic resonance (NMR), magnetic-resonance imaging (MRI), inertial-rotation sensing, magnetic microscopy with cold atoms, and tests of fundamental symmetries of Nature.Comment: 11 pages; 4 figures; submitted to Nature Physic

    Bacteriological and physico-chemical assessment of wastewater in different region of Tunisia: impact on human health

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    <p>Abstract</p> <p>Background</p> <p>In many parts of the world, health problems and diseases have often been caused by discharging untreated or inadequately treated wastewater. In this study, we aimed to control physico-chemical parameters in wastewater samples. Also, microbiological analyses were done to reveal <it>Salmonella </it>strains and each <it>Escherichia coli </it>(<it>E.coli</it>) pathotype.</p> <p>Findings</p> <p>Sixty wastewater samples were collected from fifteen different regions of Tunisia. All physico-chemical parameters (pH, residual free chlorine, total suspended solids, biological oxygen demand, and chemical oxygen demand) were evaluated.</p> <p>For microbiological analyses, samples were filtered to concentrate bacteria. DNA was extracted by boiling and subjected to polymerase chain reaction (PCR) using different pairs of primers.</p> <p>The mean pH values recorded for the sampling point were above the WHO pH tolerance limit. The total suspended solids (TSS) concentrations varied between 240 mg/L and 733 mg/L in entrance points and between 13 mg/L and 76 mg/L in exit points. In entrance points, the studied wastewater has an average COD concentration that varied between 795 mg/mL to 1420 mg/mL. Whereas, BOD concentration of the wastewater ranged between 270 mg/L to 610 mg/L. In exit points, COD concentration varied between 59 mg/L and 141 mg/L, whereas BOD concentration ranged from 15 mg/L to 87 mg/L.</p> <p>The bacteriological control of wastewaters showed that, in entrance points, <it>Escherichia coli </it>(<it>E.coli</it>) was detected at the rate of 76.6%. Three <it>E.coli </it>pathotypes were found: ETEC (53.3%), EAEC (16.6%) and EIEC (6.6%).</p> <p>Concerning the ETEC isolated strains, 8 of 16 (50%) have only the heat-labile toxin gene, 5 of 16 (31.2%) present only the heat-stable toxin gene and 3 of 16 (18.7%) of strains possess both heat-labile toxin gene and heat-stable toxin gene. In exist point, the same pathotypes were found but all detected ETEC strains present only the "est" gene.</p> <p>Concerning <it>Salmonella </it>isolated strains; percentages of 66.6% and 20% were found in entrance and exit points respectively.</p> <p>Conclusions</p> <p>Wastewaters contain a large amount of pathogenic bacteria that present a real impact on human health. Assessment wastewater treatment stations have to consider in account enterobacterial pathogens as potential pathogens that should be correctly controlled.</p

    Direct intra-abdominal pressure monitoring via piezoresistive pressure measurement: a technical note

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    <p>Abstract</p> <p>Background</p> <p>Piezoresistive pressure measurement technique (PRM) has previously been applied for direct IAP measurement in a porcine model using two different devices. Aim of this clinical study was to assess both devices regarding complications, reliability and agreement with IVP in patients undergoing elective abdominal surgery.</p> <p>Methods</p> <p>A prospective cohort study was performed in 20 patients randomly scheduled to receive PRM either by a Coach<sup>®</sup>-probe or an Accurate++<sup>®</sup>-probe (both MIPM, Mammendorf, Germany). Probes were placed on the greater omentum and passed through the abdominal wall paralleling routine drainages. PRM was compared with IVP measurement by t-testing and by calculating mean difference as well as limits of agreement (LA).</p> <p>Results</p> <p>There were no probe related complications. Due to technical limitations, data could be collected in 3/10 patients with Coach<sup>® </sup>and in 7/10 patients with Accurate++<sup>®</sup>. Analysis was carried out only for Accurate++<sup>®</sup>. Mean values did not differ to mean IVP values. Mean difference to IVP was 0.1 ± 2.8 mmHg (LA: -5.5 to 5.6 mmHg).</p> <p>Conclusion</p> <p>Direct IAP measurement was clinically uneventful. Although results of Accurate++<sup>® </sup>were comparable to IVP, the device might be too fragile for IAP measurements in the clinical setting. Local ethical committee trial registration: EK2024</p

    Comparative efficacy and safety of biosimilar infliximab and other biological treatments in ankylosing spondylitis: systematic literature review and meta-analysis.

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    OBJECTIVES: To compare the efficacy and safety of infliximab-biosimilar with other biological drugs for the treatment of active ankylosing spondylitis (AS). METHODS: Systematic literature review for randomized controlled trials (RCTs) with adalimumab, etanercept, golimumab, infliximab and infliximab-biosimilar in AS was performed and indirect meta-analysis (Bayesian mixed treatment comparison) was carried out. The proportion of patients reaching 20 % improvement by the assessment of Spondyloarthritis International Society response criteria (ASAS20) at weeks 12 and 24 was used as efficacy endpoints, and the occurrence of serious adverse events at week 24 was applied to compare the safety of the biologicals. RESULTS: Altogether, 13 RCTs, identified by the systematic literature search, were included in the analysis. Results on the ASAS20 efficacy endpoint were reported for week 12 in 12 RCTs involving 2,395 patients, and for week 24 in 5 RCTs comprising 1,337 patients. All the five biological agents proved to be significantly superior to placebo. Infliximab showed the highest odds ratio (OR) of 7.2 (95 % CI 3.68-13.19) compared to placebo, followed by infliximab-biosimilar with OR 6.25 (95 % CI 2.55-13.14), both assessed at week 24. No significant difference was found between infliximab-biosimilar and other biological treatments regarding their efficacy and safety. CONCLUSIONS: This is the first study which includes a biosimilar drug in the meta-analysis of biological treatments in AS. The results have proven the similar efficacy and safety profile of infliximab-biosimilar treatment compared to other biologicals

    Prodigious submarine landslides during the inception and early growth of volcanic islands

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    Volcanic island inception applies large stresses as the ocean crust domes in response to magma ascension and is loaded by eruption of lavas. There is currently limited information on when volcanic islands are initiated on the seafloor, and no information regarding the seafloor instabilities island inception may cause. The deep sea Madeira Abyssal Plain contains a 43 million year history of turbidites among which many originate from mass movements in the Canary Islands. Here, we investigate the composition and timing of a distinctive group of turbidites that we suggest represent a new unique record of large-volume submarine landslides triggered during the inception, submarine shield growth, and final subaerial emergence of the Canary Islands. These slides are predominantly multi-stage and yet represent among the largest mass movements on the Earth’s surface up to three or more-times larger than subaerial Canary Islands flank collapses. Thus whilst these deposits provide invaluable information on ocean island geodynamics they also represent a significant, and as yet unaccounted, marine geohazard

    Paramedics' perceptions and experiences of pelvic injuries in prehospital situations

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    In recent years there has been an increase in pelvic injuries due to an increase in road traffic collisions (RTCs) (Chesters 2017). Two thirds of pelvic injuries are due to RTCs and the remainder are made up of pedestrian collisions, motorcycle accidents and falls from heights. Patients with fatal pelvic injuries more than likely die of exsanguinations and/or associated severe injuries (ibid.). Lee & Porter (2007) undertook a literature review to analyse the current practice of assessing and managing pelvic injuries in pre-hospital situations. They write that the mortality rates of patients with pelvic fractures are estimated between 7% and 19%, upon their arrival at hospital. The mortality rates of patients with ‘open book’ fractures can be as high as 50%. An ‘open book’ fracture can be defined as any serious fracture that causes the pelvic ring to open like a book. This is commonly seen in anterior injuries to the pelvis widening the pubic symphysis (Gerecht, Larrimore & Steuerwald 2014). Lee and Porter (2007) argue that paramedics can help reduce the retroperitoneal space that a patient can haemorrhage into, and therefore lower the mortality rates for patients with ‘open-book’ pelvic fractures. Given the high mortality rates associated with pelvic injuries and the role paramedics can play in reducing these outcomes, the aim of this narrative review is to synthesize existing literature about pelvic injury recognition, assessment and management in pre-hospital situations. The authors will also conclude upon any new insights or recommendations found following the review

    A cross-sectional study of different patterns of oral contraceptive use among premenopausal women and circulating IGF-1: implications for disease risk

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    <p>Abstract</p> <p>Background</p> <p>Insulin-like growth factor-1 (IGF-1) is important in normal growth, development, and homeostasis. Current use of oral contraceptives (OC) decreases IGF-1 concentrations; however, the effect of past use, age/timing of use, and type of OC used on IGF-1 levels is unknown. OC are the most commonly used form of birth control worldwide. Both IGF-1 and OC use have been linked to premenopausal breast and colorectal cancers, osteoporosis and cardiovascular disease (CVD). Understanding the effects of different patterns of OC use on IGF-1 levels may offer insight into its influence on disease risk in young women.</p> <p>Methods</p> <p>In a cross-sectional study of 328 premenopausal women ages 18 to 21 and 31 to 40 we examined the relationship between different patterns of OC use and circulating IGF-1 using adjusted linear regression analysis. Information on OC use was obtained through an interviewer administered questionnaire. Plasma IGF-1 was assessed with enzyme linked immunosorbent assay (ELISA).</p> <p>Results</p> <p>Among women aged 18 to 21, ever OC use was significantly associated with decreased IGF-1 levels compared to never use (β = -57.2 ng/ml, 95% confidence interval (CI): -88.7, -25.8). Among women aged 31 to 40, past users who first used OC at 25 years of age or older (β = 43.8 ng/ml, 95% CI: 8.8, 78.8), in the last 15 years (β = 35.1 ng/ml, 95% CI: 9.3, 61.0) or after 1995 (β = 46.6 ng/ml, 95% CI: 13.4, 79.8) had significantly higher IGF-1 levels compared to never users.</p> <p>Conclusion</p> <p>This is the first study to highlight the long term effects of OC use after cessation on IGF-1 levels among premenopausal women, which previously were thought to be transitory. Future studies of past use and IGF-1 levels are required and must consider age/timing of use and type/generation of OC used. Additional studies are needed to confirm the potential mediation of IGF-1 levels in the links between OC use and health outcomes.</p
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