88 research outputs found
Ultralong Raman Fiber Lasers as Virtually Lossless Optical Media
By transforming the optical fiber span into an ultralong cavity laser, we experimentally demonstrate quasilossless transmission over long (up to 75 km) distances and virtually zero signal power variation over shorter (up to 20 km) spans, opening the way for the practical implementation of integrable nonlinear systems in optical fiber. As a by-product of our technique, the longest ever laser (to the best of our knowledge) has been implemented, with a cavity length of 75 km. A simple theory of the lossless fiber span, in excellent agreement with the observed results, is presented
Initial Public Offerings and the Firm Location
The firm geographic location matters in IPOs because investors have a strong preference for newly issued local stocks and provide abnormal demand in local offerings. Using equity holdings data for more than 53,000 households, we show the probability to participate to the stock market and the proportion of the equity wealth is abnormally increasing with the volume of the IPOs inside the investor region. Upon nearly the universe of the 167,515 going public and private domestic manufacturing firms, we provide consistent evidence that the isolated private firms have higher probability to go public, larger IPO underpricing cross-sectional average and volatility, and less pronounced long-run under-performance. Similar but opposite evidence holds for the local concentration of the investor wealth. These effects are economically relevant and robust to local delistings, IPO market timing, agglomeration economies, firm location endogeneity, self-selection bias, and information asymmetries, among others. Findings suggest IPO waves have a strong geographic component, highlight that underwriters significantly under-estimate the local demand component thus leaving unexpected money on the table, and support state-contingent but constant investor propensity for risk
25th annual computational neuroscience meeting: CNS-2016
The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong
26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15–20 July 2017
This work was produced as part of the activities of FAPESP Research,\ud
Disseminations and Innovation Center for Neuromathematics (grant\ud
2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud
FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud
supported by a CNPq fellowship (grant 306251/2014-0)
The Monetary Value of Good College Presidents: Interims, new presidents, and long term presidents’ effect on giving to private universities and colleges
Successful fundraising is essential to the financial health of private colleges and universities in the United States. Using OLS, one year lagged, fixed effects regression analysis I examine institutions’ presidents’ impact on fundraising. Merging two well-known higher education data sets with a presidential dataset I create, I study 231 schools during 2001-2010. The results suggest that long term presidents are great fundraisers beginning the first day they step into office. Interim presidents, in contrast, inhibit donations. Strangely, I find that presidents do not improve at fundraising throughout their tenure
Eptifibatide: A Pharmacoeconomic Review of its Use in Percutaneous Coronary Intervention and Acute Coronary Syndromes
Eptifibatide (Integrilin(R)) is a selective inhibitor of platelet glycoprotein (GP) IIb/IIIa receptors used as adjunctive therapy for patients undergoing percutaneous coronary intervention (PCI) and for patients with acute coronary syndromes (ACS), particularly those requiring PCI. Most economic analyses of eptifibatide have incorporated clinical and healthcare resource use data from either the ESPRIT (Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin(R) Therapy) study in low- to moderate-risk patients undergoing selective PCI with stent implantation or the PURSUIT (Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin(R) Therapy) trial in patients with ACS. Eptifibatide achieved statistically significant reductions in combined endpoints of death and ischaemic complications in both of these large multicentre clinical trials, in which patients were randomised to receive intravenous eptifibatide or placebo as adjunctive therapy to heparin and aspirin (plus a thienopyridine in ESPRIT). In US economic analyses using ESPRIT trial data, approximately 40% and 70% of the acquisition cost of eptifibatide was offset by reduced medical resource consumption during the initial hospitalisation period and over a 1-year period, respectively. Eptifibatide was associated with a favourable cost-effectiveness ratio of US3761-$US18 Conclusion: Significant clinical benefits have been demonstrated with eptifibatide as adjunctive therapy in patients undergoing selective PCI with stent implantation in the ESPRIT trial and in patients with ACS in the PURSUIT trial. Pharmacoeconomic analyses using data from either ESPRIT or PURSUIT have demonstrated favourable cost-effectiveness ratios for both indications in various countries. ESPRIT-based results from the limited number of available economic analyses are particularly favourable. The cost-effectiveness of eptifibatide in ACS (i.e. PURSUIT-based results) may be further improved by targeting the drug for patients in whom catheterisation and PCI are planned, although further analyses are required to confirm this.Acute-coronary-syndromes, Adis-Drug-Evaluations, Antiplatelets, Coronary-interventions, Eptifibatide, GPIIb-IIIa-antagonists
Spotlight on Eptifibatide in Percutaneous Coronary Intervention and Acute Coronary Syndromes
Eptifibatide (Integrilin(R)) is a selective inhibitor of platelet glycoprotein IIb/IIIa receptors used as adjunctive therapy for patients undergoing percutaneous coronary intervention (PCI) and for patients with acute coronary syndromes (ACS), particularly those requiring PCI. Most economic analyses of eptifibatide have incorporated clinical and healthcare resource use data from either the ESPRIT (Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin(R) Therapy) study in low- to moderate-risk patients undergoing selective PCI with stent implantation or the PURSUIT (Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin(R) Therapy) trial in patients with ACS. Eptifibatide achieved statistically significant reductions in combined endpoints of death and ischemic complications in both of these large multicenter clinical trials, in which patients were randomized to receive intravenous eptifibatide or placebo as adjunctive therapy to heparin and aspirin (plus a thienopyridine in ESPRIT). In US economic analyses using ESPRIT trial data, approximately 40% and 70% of the acquisition cost of eptifibatide was offset by reduced medical resource consumption during the initial hospitalization period and over a 1-year period, respectively. Eptifibatide was associated with a favorable cost-effectiveness ratio of US3761-$US18 In conclusion, significant clinical benefits have been demonstrated with eptifibatide as adjunctive therapy in patients undergoing selective PCI with stent implantation in the ESPRIT trial and in patients with ACS in the PURSUIT trial. Pharmacoeconomic analyses using data from either ESPRIT or PURSUIT have demonstrated favorable cost-effectiveness ratios for both indications in various countries. ESPRIT-based results from the limited number of available economic analyses are particularly favorable. The cost-effectiveness of eptifibatide in ACS (i.e. PURSUIT-based results) may be further improved by targeting the drug for patients in whom catheterisation and PCI are planned, although further analyses are required to confirm this.Acute-coronary-syndromes, Adis-Spotlights, Angioplasty, Eptifibatide
Management of Alzheimer's Disease: Defining the Role of Donepezil
Alzheimer's disease affects 15 million people worldwide. As the elderly population grows, the incidence of Alzheimer's disease will also increase. It is estimated that by 2010, 40 million US citizens will be over the age of 65 years and by 2040, it is predicted that 14 million US citizens will have Alzheimer's disease. There is currently no treatment which stops or delays the progression of this condition; however, anticholinesterase therapy provides some symptomatic relief. The cognitive impairment experienced by patients with Alzheimer's disease is partially due to degeneration of cholinergic pathways within the CNS and therefore symptomatic treatments have focused on restoring cholinergic inputs. Donepezil is a second generation anticholinesterase drug which reduces cortical acetylcholinesterase activity and improves, or at least slows the decline in, cognitive functioning in patients with Alzheimer's disease. In patients with mild to moderate Alzheimer's disease, treatment with donepezil (5 to 10 mg/day) for 1 year extended the median time to a clinically evident functional decline by 5 months compared with treatment with placebo. In addition, patients receiving donepezil have also shown significant improvement in ratings of global function, cognition, activities of daily living and disease severity over a 1-year period (pAcetylcholinesterase inhibitors, Alzheimer's disease, Antioxidants, Cholinesterase inhibitors, Donepezil, Galantamine, Rivastigmine
Management of Rheumatoid Arthritis: Defining the Role of Leflunomide
Rheumatoid arthritis is a progressive, disabling disease which can lead to long-term deformity and disability. Leflunomide is a disease-modifying antirheumatic drug (DMARD) approved to reduce signs and symptoms, inhibit structural damage and improve physical function in adults with active rheumatoid arthritis. In clinical trials in patients with active rheumatoid arthritis, leflunomide had a more rapid onset of action than methotrexate, sulfasalazine and placebo. In trials of 24 months' duration, leflunomide was more effective than sulfasalazine and placebo and at least as effective as methotrexate in reducing rheumatoid arthritis disease activity (assessed using the American College of Rheumatology [ACR] criteria). In addition, leflunomide was as effective as sulfasalazine or methotrexate in decreasing the rate of radiological progression over 24 months. Over 12 months leflunomide was more effective than methotrexate and placebo in reducing the rate of structural damage. Data from a nonblind extension study suggests that the efficacy of leflunomide may be maintained when administered for periods up to 5 years. Leflunomide was significantly more effective than methotrexate, sulfasalazine and placebo in improving physical function measures among patients with active rheumatoid arthritis, and improved physical function was maintained after 2 years of treatment. Few well designed pharmacoeconomic analyses of leflunomide treatment in patients with rheumatoid arthritis exist. Economic studies to date show leflunomide to be either less cost effective or cost neutral compared to methotrexate. In addition, leflunomide has been shown to be a cost effective option compared with etanercept, infliximab and infliximab plus methotrexate. Leflunomide was generally well tolerated in clinical trials. Common adverse events associated with leflunomide treatment include diarrhea, respiratory infections, nausea and headache. Hematological and hepatotoxic adverse events are a concern, particularly in a setting of multiple risk factors such as concomitant hepatotoxins. Liver function monitoring should be adhered to in all patients receiving leflunomide and ACR guidelines should be followed in those receiving concomitant methotrexate. In conclusion, leflunomide is a DMARD which produces a rapid and sustained reduction in disease activity in patients with active rheumatoid arthritis. Leflunomide has a more rapid onset of action than sulfasalazine or methotrexate. Leflunomide is at least as effective as methotrexate and more effective than sulfasalazine in reducing disease activity after 24 months' treatment. In addition, leflunomide is more effective than both of these agents in improving physical function and health-related quality of life. Thus it is predicted that leflunomide therapy may improve the long-term outcome of patients with rheumatoid arthritis and reduce the substantial burden imposed by the disease for patient, healthcare provider and payers. Consequently, leflunomide should be considered as an important treatment option for those patients with active rheumatoid arthritis including those intolerant to methotrexate.Adis-Drug-Evaluations, Leflunomide, Pharmacoeconomics, Quality-of-life, Rheumatoid-arthritis
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