22 research outputs found

    HRFlexToT: A High Dynamic Range ASIC for Time-of-Flight Positron Emission Tomography

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    Abstract: Time-of-Flight positron emission tomography scanners demand fast and efficient photo sensors and scintillators coupled to fast readout electronics. This article presents the high resolution flexible Time-over-Threshold (HRFlexToT), a 16-channel application-specific-integrated circuit for silicon photomultipliers (SiPM) anode readout manufactured using XFAB 0.18- μm CMOS technology. The main features of the HRFlexToT are a linear Time-over-Threshold with an extended dynamic range (10 bits) for energy measurement, low power consumption (≈ 3.5 mW/ch), and an excellent timing response. The experimental measurements show an energy linearity error of ≈ 3% and an energy resolution of about 12% at 511 keV. Single-photon time resolution measurements performed using an Fondazione Bruno Kessler (FBK) SiPM NUV-HD ( 4×4 mm2 pixel, 40- μm cell) and a Hamamatsu SiPM S13360-3050CS are around 142 and 167 ps full width at half maximum (FWHM), respectively. Coincidence time resolution (CTR) measurements with small cross-section pixelated crystals (LSO:Ce,Ca 0.4%, 2×2×5 mm3) coupled to the same Hamamatsu S13360-3050CS and FBK NUV-HD sensors yield a CTR of 117 ps and 119 ps, respectively. Measurements performed with a large cross-section monolithic crystal (LFS crystal measuring 25×25×20 mm3) and a Hamamatsu SiPM array S13361-6050NE-04 show a CTR of 324 ps FWHM after time-walk and time-skew correction

    HRFlexToT: A High Dynamic Range ASIC for Time-of-Flight Positron Emission Tomography

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    Time-of-Flight positron emission tomography scanners demand fast and efficient photo sensors and scintillators coupled to fast readout electronics. This article presents the high resolution flexible Time-over-Threshold (HRFlexToT), a 16-channel application-specific-integrated circuit for silicon photomultipliers (SiPM) anode readout manufactured using XFAB 0.18- \mu \text{m} CMOS technology. The main features of the HRFlexToT are a linear Time-over-Threshold with an extended dynamic range (10 bits) for energy measurement, low power consumption (≈ 3.5 mW/ch), and an excellent timing response. The experimental measurements show an energy linearity error of ≈ 3% and an energy resolution of about 12% at 511 keV. Single-photon time resolution measurements performed using an Fondazione Bruno Kessler (FBK) SiPM NUV-HD ( 4 \times 4 mm2 pixel, 40- \mu \text{m} cell) and a Hamamatsu SiPM S13360-3050CS are around 142 and 167 ps full width at half maximum (FWHM), respectively. Coincidence time resolution (CTR) measurements with small cross-section pixelated crystals (LSO:Ce,Ca 0.4%, 2 \times 2 \times 5 mm3) coupled to the same Hamamatsu S13360-3050CS and FBK NUV-HD sensors yield a CTR of 117 ps and 119 ps, respectively. Measurements performed with a large cross-section monolithic crystal (LFS crystal measuring 25 \times 25 \times 20 mm3) and a Hamamatsu SiPM array S13361-6050NE-04 show a CTR of 324 ps FWHM after time-walk and time-skew correction

    ¿Mastozoología por desconocer o mastozoología por conocer?

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    As a scientific discipline, mastozoology is our best approach to the methodical and systematic study of all aspects that are associated with mammals. Although, as a result of more than three centuries of history, enormous advances have been made in their knowledge, there are still innumerable questions, unresolved issues and problems to be solved. This means a huge opportunity for the exercise of the discipline itself, and, in addition, a call for attention to all generations of mastozoologists to fill these gaps.Como disciplina científica, la mastozoología es nuestra mejor aproximación al estudio metódico y sistemático de todos los aspectos que se asocian con los mamíferos. Aunque como resultado de más de tres siglos de historia se han hecho enormes avances en su conocimiento, aún quedan innumerables preguntas, temas sin resolver y problemas por solucionar. Esto significa una enorme oportunidad para el ejercicio mismo de la disciplina, y, además, un llamado de atención a todas las generaciones de mastozoólogos para llenar estos vacíos

    A High Dynamic Range ASIC for Time of Flight PET with monolithic crystals

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    The HRFlexToT is a 16-channel ASIC for SiPM anode readout designed for Positron Emission Tomography (PET) applications that features high dynamic range (>8 bits), low input impedance, common cathode connection, high speed and low power (~3.5 mW/ch). The ASIC has been manufactured using XFAB 0.18 mm CMOS technology. The main characteristics of the HRFlexToT, compared to its predecessor, are a new energy measurement readout providing a linear Time Over Threshold (ToT) with an extended dynamic range, lower power consumption and better timing response. Initial measurements show a linearity error below 3%. Single Photon Time Resolution (SPTR) measurements performed using a Hamamatsu MPPC S13360-3050CS (3x3 mm2 pixel, 50 umm cell) shows 30% improvement with respect to the previous version of the ASIC, setting this specification in the order of 141 ps FWHM and reducing 3 times power consumption. It is important to highlight that an SPTR of 141 ps FWHM is, according to the best of our knowledge, the best resolution achieved so far for this sensor. Coincidence Time Resolution (CTR) measurements are expected to be performed during 2018

    Ciudades biodiversas: mamíferos medianos de la Reserva Forestal Protectora Bosque Oriental de Bogotá D. C., Colombia

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    In this contribution, we present an updated list of medium-sized mammals present in the Bosque Oriental Protective Forest Reserve of Bogotá. The study area includes the Bogotá Bosque Oriental Protective Forest Reserve that is located east of the city of Bogotá D.C., and commonly known as Eastern Hills.En esta contribución, presentamos un listado actualizado de los mamíferos medianos presentes en la Reserva Forestal Protectora Bosque Oriental de Bogotá. El área de estudio comprende la Reserva Forestal Protectora Bosque Oriental de Bogotá que se localiza al oriente de la ciudad de Bogotá D.C., y comúnmente conocida como Cerros Orientales

    Tocilizumab in refractory Caucasian Takayasu's arteritis: a multicenter study of 54 patients and literature review

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    Objective: To assess the efficacy and safety of tocilizumab (TCZ) in Caucasian patients with refractory Takayasu's arteritis (TAK) in clinical practice. Methods: A multicenter study of Caucasian patients with refractory TAK who received TCZ. The outcome variables were remission, glucocorticoid-sparing effect, improvement in imaging techniques, and adverse events. A comparative study between patients who received TCZ as monotherapy (TCZMONO) and combined with conventional disease modifying anti-rheumatic drugs (cDMARDs) (TCZCOMBO) was performed. Results: The study comprised 54 patients (46 women/8 men) with a median [interquartile range (IQR)] age of 42.0 (32.5-50.5) years. TCZ was started after a median (IQR) of 12.0 (3.0-31.5) months since TAK diagnosis. Remission was achieved in 12/54 (22.2%), 19/49 (38.8%), 23/44 (52.3%), and 27/36 (75%) patients at 1, 3, 6, and 12 months, respectively. The prednisone dose was reduced from 30.0 mg/day (12.5-50.0) to 5.0 (0.0-5.6) mg/day at 12 months. An improvement in imaging findings was reported in 28 (73.7%) patients after a median (IQR) of 9.0 (6.0-14.0) months. Twenty-three (42.6%) patients were on TCZMONO and 31 (57.4%) on TCZCOMBO: MTX (n = 28), cyclosporine A (n = 2), azathioprine (n = 1). Patients on TCZCOMBO were younger [38.0 (27.0-46.0) versus 45.0 (38.0-57.0)] years; difference (diff) [95% confidence interval (CI) = -7.0 (-17.9, -0.56] with a trend to longer TAK duration [21.0 (6.0-38.0) versus 6.0 (1.0-23.0)] months; diff 95% CI = 15 (-8.9, 35.5), and higher c-reactive protein [2.4 (0.7-5.6) versus 1.3 (0.3-3.3)] mg/dl; diff 95% CI = 1.1 (-0.26, 2.99). Despite these differences, similar outcomes were observed in both groups (log rank p = 0.862). Relevant adverse events were reported in six (11.1%) patients, but only three developed severe events that required TCZ withdrawal. Conclusion: TCZ in monotherapy, or combined with cDMARDs, is effective and safe in patients with refractory TAK of Caucasian origin.Funding: This work was partially supported by RETICS Programs, RD08/0075 (RIER), RD12/0009/0013 and RD16/0012 from “Instituto de Salud Carlos III” (ISCIII) (Spain)

    A Service of zbw Leibniz-Informationszentrum Wirtschaft Leibniz Information Centre for Economics Are Environmentally Related Taxes Effective? Are Environmentally Related Taxes Effective? Are environmentally related taxes effective?

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    Standard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of the Inter-American Development Bank, its Board of Directors, or the countries they represent. Terms of use: Documents in The unauthorized commercial use of Bank documents is prohibited and may be punishable under the Bank's policies and/or applicable laws. Copyright © Inter-American Development Bank. This working paper may be reproduced for any non-commercial purpose. It may also be reproduced in any academic journal indexed by the American Economic Association's EconLit, with previous consent by the Inter-American Development Bank (IDB), provided that the IDB is credited and that the author(s) receive no income from the publication. Cataloging-in-Publication Abstract This paper focuses on the question of whether the magnitude of long-established environmentally related taxes (ERT) is related to countries environmental performance. While environmental taxes efficiencies have previously been discussed, those taxes contribution to reducing pollution and improving environmental quality has not been fully explored. This paper therefore analyzes the effectiveness of environmental taxes by examining the environmental performance of 50 countries from all regions in association with the amount of revenues from environmentally related taxes each country collects. Using a cross-section regression and a panel dynamic regression, the paper finds that countries with higher revenues from these types of taxes also exhibit higher reductions in CO2 emission, PM10 emissions, and energy consumption and production from fossil sources. JEL classification: H23, Q58, Q530

    Are Environmentally Related Taxes Effective?

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    This paper focuses on the question of whether the magnitude of long-established environmentally related taxes (ERT) is related to countries environmental performance. While environmental taxes efficiencies have previously been discussed, those taxes contribution to reducing pollution and improving environmental quality has not been fully explored. This paper therefore analyzes the effectiveness of environmental taxes by examining the environmental performance of 50 countries from all regions in association with the amount of revenues from environmentally related taxes each country collects. Using a cross-section regression and a panel dynamic regression, the paper finds that countries with higher revenues from these types of taxes also exhibit higher reductions in CO2 emission, PM10 emissions, and energy consumption and production from fossil sources.

    Is Disaster Risk Reduction Spending Driven by the Occurrence of Natural Disasters? Evidence from Peru

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    This paper studies the allocation of total disaster risk reduction public spending among regions in Peru. The main objective of this work is to identify the main determinants of the distribution of these resources, and for this purpose an index of historical physical impacts of natural disasters, social vulnerability, and institutional capacity was created. It is found that historical impacts of climatological disasters are positively correlated with the per capita amount received by region in order to prevent future natural disasters. Impacts of geological disaster, on the other hand, affect the amount of executed and budgeted resources used to cope with the effects of past disasters. The prevention expenditure is mainly driven by climatological effects on the agriculture sector. Additionally, results confirm that higher social vulnerability is a main determinant of the distribution of prevention spending but conditioned on being affected by climatological disasters. Institutional capacity seems to define only the amount of recovery expenditure, positively for regions more seriously affected by geological disasters and negatively for regions devastated by climatological disasters.
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