2,810 research outputs found

    A simulation model for the demographic transition in the OECD: Data requirements, model structure and calibration

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    The developed world stands at the fore of a phenomenal demographic transition. Over the next 30 years the number of elderly in the OECD countries will more than double. At the same time, the number of workers available to pay the elderly their government-guaranteed pension and health care benefits will rise by less than 10 percent. These two demographic trends are expected to put enormous pressure on social security systems and government expenses. To address the consequences of the aging process, this paper develops a dynamic, intergenerational, and interregional demographic life-cycle model. The model has three regions - the U.S., the EU and Japan - which exchange goods and capital. The model features immigration, age-specific fertility, life span extension, life span uncertainty, bequests arising from incomplete annuitization, and intra-cohort heterogeneity. After introducing the theoretical model, we simulate the transition path for the three considered regions keeping current immigration constant, assuming the projected increase in life expectancy and the continuation of current social security and health care policies. --Demographic transition,overlapping generations (OLG),computable general equilibrium models (CGE)

    Photon-bunching measurement after 2x25km of standard optical fibers

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    To show the feasibility of a long distance partial Bell-State measurement, a Hong-Ou-Mandel experiment with coherent photons is reported. Pairs of degenerate photons at telecom wavelength are created by parametric down conversion in a periodically poled lithium niobate waveguide. The photon pairs are separated in a beam-splitter and transmitted via two fibers of 25km. The wave-packets are relatively delayed and recombined on a second beam-splitter, forming a large Mach-Zehnder interferometer. Coincidence counts between the photons at the two output modes are registered. The main challenge consists in the trade-off between low count rates due to narrow filtering and length fluctuations of the 25km long arms during the measurement. For balanced paths a Hong-Ou-Mandel dip with a visibility of 47.3% is observed, which is close to the maximal theoretical value of 50% developed here. This proves the practicability of a long distance Bell state measurement with two independent sources, as e.g. required in an entanglement swapping configuration in the scale of tens of km.Comment: 6 pages, 5 figure

    Waveguide-based OPO source of entangled photon pairs

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    In this paper we present a compact source of narrow-band energy-time entangled photon pairs in the telecom regime based on a Ti-indiffused Periodically Poled Lithium Niobate (PPLN) waveguide resonator, i.e. a waveguide with end-face dielectric multi-layer mirrors. This is a monolithic doubly resonant Optical Parametric Oscillator (OPO) far below threshold, which generates photon pairs by Spontaneous Parametric Down Conversion (SPDC) at around 1560nm with a 117MHz (0.91 pm)- bandwidth. A coherence time of 2.7 ns is estimated by a time correlation measurement and a high quality of the entangled states is confirmed by a Bell-type experiment. Since highly coherent energy-time entangled photon pairs in the telecom regime are suitable for long distance transmission and manipulation, this source is well suited to the requirements of quantum communication.Comment: 13 page

    Economic analysis of pandemic influenza mitigation strategies for five pandemic severity categories

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    BACKGROUND: The threat of emergence of a human-to-human transmissible strain of highly pathogenic influenza A(H5N1) is very real, and is reinforced by recent results showing that genetically modified A(H5N1) may be readily transmitted between ferrets. Public health authorities are hesitant in introducing social distancing interventions due to societal disruption and productivity losses. This study estimates the effectiveness and total cost (from a societal perspective, with a lifespan time horizon) of a comprehensive range of social distancing and antiviral drug strategies, under a range of pandemic severity categories. METHODS: An economic analysis was conducted using a simulation model of a community of ~30,000 in Australia. Data from the 2009 pandemic was used to derive relationships between the Case Fatality Rate (CFR) and hospitalization rates for each of five pandemic severity categories, with CFR ranging from 0.1% to 2.5%. RESULTS: For a pandemic with basic reproduction number R(0) = 1.8, adopting no interventions resulted in total costs ranging from 441perpersonforapandemicatcategory1(CFR0.1441 per person for a pandemic at category 1 (CFR 0.1%) to 8,550 per person at category 5 (CFR 2.5%). For severe pandemics of category 3 (CFR 0.75%) and greater, a strategy combining antiviral treatment and prophylaxis, extended school closure and community contact reduction resulted in the lowest total cost of any strategy, costing $1,584 per person at category 5. This strategy was highly effective, reducing the attack rate to 5%. With low severity pandemics costs are dominated by productivity losses due to illness and social distancing interventions, whereas higher severity pandemic costs are dominated by healthcare costs and costs arising from productivity losses due to death. CONCLUSIONS: For pandemics in high severity categories the strategies with the lowest total cost to society involve rigorous, sustained social distancing, which are considered unacceptable for low severity pandemics due to societal disruption and cost

    Efficacy and safety of bimatoprost 0.01% formulated in tight junction modulation technology compared to marketed benzalkonium chloride preserved bimatoprost 0.01% ophthalmic solution in healthy beagle dogs

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    Background: This study was undertaken to compare the efficacy and safety of the new technology tight junction modulation (TJM) bimatoprost 0.01% (TJM-bimatoprost), containing polyhexamethylene biguanide hydrochloride as a preservative, and marketed bimatoprost 0.01% (BKC-bimatoprost) in healthy beagle dogs.Methods: This was a cross-over study and all animals in the study were assigned to one of two treatment arms to receive either TJM-bimatoprost (n=6) or BKC-bimatoprost (n=6) ophthalmic solution. Dosing for period 1 was started on day 3 (8 am everyday) and it continued till day 12. Assessments were carried out every day at 8 am, 9 am, 2 pm and 8 pm throughout the study period till day 17.Results: For the pooled analysis (n=12 in each group) of period 1 and 2, there was a significant decrease (p<0.001) in mean intra-ocular (IOP) 1 hour post administration as compared to the baseline and this trend continued all throughout the study in both treatment arms. Twenty fours after last dose, on day 12, IOP measurements were 14.20±1.59 mmHg and 13.89±1.5 mmHg in the TJM-bimatoprost and the BKC-bimatoprost group respectively. The analysis of the primary end point revealed that 95% confidence interval for the between group differences in mean IOP values were well within the pre-defined equivalence margin of ±1.5 mmHg. In terms of safety, there was no difference in mean pupillary diameter in the TJM-bimatoprost and BKC-bimatoprost group.Conclusions: The results of this study enhance our understanding of the proprietary TJM technology by establishing efficacy and safety of TJM-bimatoprost in animal models.

    Gastric Follicular Dendritic Cell Sarcoma: A Case Report of a Rare Entity

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    Follicular Dendritic cell sarcoma arises from the follicular dendritic cells present in the lymphnode.Though are commonly seen in head and neck area but are extremely rare in the abdomen. Less than eighty cases are reported in the indexed literature. We herein describe a case of follicular dendritic cell sarcoma arising from the stomach wall with infiltration into pancreas in an 85 year old patient
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