407 research outputs found
The Effects of Child-Bearing on Married Women's Labor Supply and Earnings: Using Twin Births as a Natural Experiment
Married women's decisions about child-bearing and market work are importantly interrelated. Although there are many estimates of the effects of fertility on female labor supply few of them have adequately addressed the problems of simultaneity inherent in these choices. In this paper, we use exogenous variations in fertility due to twin births to measure the impact of an unanticipated child on married women's labor supply and earnings. We find that the short-run effects of an unanticipated birth on labor supply are appreciable and have increased in magnitude as more mothers enter the labor market. It also appears that the impact of unanticipated births on earnings and wages has changed from 1980 to 1990. In 1980 reduced labor supply caused a temporary drop in earnings, but in 1990 earnings and wages remained depressed well after the labor supply effects of a twin birth had disappeared.
Targeted treatment of advanced ovarian cancer: spotlight on rucaparib.
The last 2 years have ushered in a new era in ovarian cancer therapy with the US Food and Drug Administration\u27s (FDA) approval of poly-ADP ribose polymerase (PARP) inhibitors (PARPi). One of the deadliest cancers that women experience, ovarian cancer, is most often diagnosed in advanced stages. Although cytoreductive surgery and (platinum/taxane-based) chemotherapy can place the majority of patients into remission, most will experience a relapse of their disease in their lifetime. This has led to studies exploring the benefits and efficacy of maintenance treatment. This review will briefly discuss the history of maintenance therapy as well as focus on the FDA\u27s approval of rucaparib and its companion tumor profiling test, in the US. It will describe how women with deleterious mutations in th
Fast Micron-Scale 3D Printing with a Resonant-Scanning Two-Photon Microscope
3D printing allows rapid fabrication of complex objects from digital designs.
One 3D-printing process, direct laser writing, polymerises a light-sensitive
material by steering a focused laser beam through the shape of the object to be
created. The highest-resolution direct laser writing systems use a femtosecond
laser to effect two-photon polymerisation. The focal (polymerisation) point is
steered over the shape of the desired object with mechanised stages or
galvanometer-controlled mirrors. Here we report a new high-resolution direct
laser writing system that employs a resonant mirror scanner to achieve a
significant increase in printing speed over galvanometer- or piezo-based
methods while maintaining resolution on the order of a micron. This printer is
based on a software modification to a commerically available resonant-scanning
two-photon microscope. We demonstrate the complete process chain from hardware
configuration and control software to the printing of objects of approximately
m, and validate performance with objective
benchmarks. Released under an open-source license, this work makes micro-scale
3D printing available the large community of two-photon microscope users, and
paves the way toward widespread availability of precision-printed devices.Comment: Corresponding author: BWP ([email protected]). TJG and TMO contributed
equally to this work. TJG is an employee of Neuralink In
Vertical migration, feeding and colouration in the mesopelagic shrimp Sergestes arcticus
Intraspecific variation in vertical distribution, timing of vertical migration, and colouration of the mesopelagic shrimp Sergestes arcticus were studied in the >400 m deep part of Masfjorden, Norway. Very few individuals were caught in the upper strata during daytime, and larger individuals occurred deeper during the day than smaller ones. Vertical migration was prominent and no overall trend of increasing length with depth was found at night. Small individuals arrived in the upper layers earlier than larger ones. Animal colouration assessed by digital photography revealed significant variance in individual redness. Depth of capture was the most important factor explaining colouration, with increasing degree of redness with depth. Assessing the gut fullness of the transparent shrimps provided a rapid way of estimating feeding activity and showed that feeding took place mainly at night
Potential Alternatives to the Disputes in the South China Sea:An Analysis
*高世明,博士,台湾海洋大学海洋事务与资源管理研究所助理研究员。电子邮箱:[email protected]。**NathanielS.Pearre,特拉华大学地球、海洋和环境学院海洋科学和政策系。[文摘]本文的目的是分析和提出解决南(中国)海主权争端僵局的潜在替代方案。该地区的背景和现状表明,主权争端不太可能在可预见的未来得到解决。基于国际法的传统争端解决机制,包括外交谈判和第三方仲裁,尽管被许多外交官和学者所推荐,但至少在不久的将来不太会在南(中国)海起到作用。由于在贯彻实施这些机制方面可能存在的困难,油气储备“共同开发冶以及海洋环境和共享资源“区域合作冶被提了出来,作为规避这些主权争端的备选方案。然而,本文认为,油气储备的共同开发在不久的将来同样不太可能起到作用,因为它也有与传统机制同样的弱点,任何解决方案都可能受到主权的影响。另一方面,合作已被公认为国际法和国际关系中的一个必要和基本原则,加之周边各方根据《联合国海洋法公约》和许多其他国际环境公约做出了许多“公域冶合作的法律承诺,该地区有关公域的一些合作活动通常都是在双边或多边的基础上
开展的。尽管在最终解决主权争端上没有进展,但对所有相关国家而言,在不久的将来,南(中国)海的区域合作也许是一种可行的替代方案。一如既往,所有各方的政治意愿对这种努力的成功是至关重要的。[Abstract]The purpose of this article is to analyze and propose potential alternatives to the stalemate of sovereignty disputes in the South China Sea.The background
and status quo in the region suggest that sovereignty disputes are not likely to be settled in the foreseeable future.Although recommended by many diplomats and scholars,traditional dispute settlement mechanisms under international law,including diplomatic negotiation and third-party arbitration,will not likely work in the South China Sea,at least in the near future.Due to the probable difficulties in implementing either of the mechanisms,“joint development”of oil and gas reserves and“regional cooperation”on the marine environment and shared resources have been recommended as alternatives to circumvent these sovereignty disputes.Nevertheless,this article finds that joint development of oil and gas reserves is similarly unlikely to work in the near future because it suffers the same weakness as traditional mechanisms,in that any resolution may have sovereignty implications.On the other hand,cooperation has been recognized as a necessary and fundamental principle in international law and international relations.In addition,there are many legal commitments by bordering States/regions to cooperate on the commons under United Nations Convention on the Law of the Sea and many other international environmental conventions.Some cooperative activities related to the commons are regularly carried out on bilateral or multilateral bases in the region.Notwithstanding the lack of progress toward final settlement of sovereignty disputes,regional cooperation in the South China Sea may be a workable alternative for all States concerned in the near future.As always,the political will of all parties is paramount to the success of such an endeavor
Electric Vehicles as a Mobile Storage Device
International audienceElectricity is a quite recent energy (150 years old) that has developed very much as it allows a flexible use through converters (electrical machines and power electronics). At the beginning, the main use was for lighting and metro. Now, electricity is a major energy for developed countries: 17.7% of the world final energy consumption and 22% for the ECD countries (IEA, 2013a; b, Figure 1), and an economic growth is always linked to an electric consumption growth. Electricity has improved our daily life: washer, dryer, dishwasher, microwaves, internet, TV, air-conditioning, and so on. Humans have become very dependent on electricity consumptions. Nevertheless, electricity is a specific product in the sense that it is a nonmaterial energy, and thus it can only be stored through a costly transformation. Electricity can be classified as a tertiary or secondary energy produced from thermal, potential, hydro (see Volume 5, Chapter XX), wind hces137, or solar energy. For a thermal plant, the primary energy (coal, gas, or uranium) is converted into mechanical energy (secondary energy) by a turbine and is transmitted to the generator to be converted into electricity (tertiary energy). As electricity is difficult to store, it needs an infrastructure to be delivered to consumers: the electrical grid that makes the link between power plants and the consumers through transformers and overhead or cabled lines. At the beginning of the twentieth century, all countries made the choice of the alternating current technology as it allowed—thanks to a key device (the transformer) transmission of high power at high voltages to reduce losses. In the context of emissions reduction (CO2, NOx, etc.), objectives have been given for cleaner energies and the use of more efficient ones. In Europe, there are the “20–20–20” targets: 20% reduction for CO2 emissions, 20% reduction in energy consumption, and 20% increase in efficiency by 2020 (see Volume 6, Chapter XX). To reach these policy goals, electricity is an appropriate vector: it is a flexible energy that can be produced from renewable or CO2-free sources, electrical converters have high efficiency (80–90% for an electric motor) and are bidirectional what makes energy recovery possible for applications such as breaking (trains, vehicles, etc.). Transportation (cars, autobuses, and trucks) is often considered a major contributor to local pollution. Then, constraints for CO2 emissions reduction are more and more severe, especially in Europe. Automakers and their suppliers have optimized their engines with innovations such as start&stop starter/generator, kinetic energy recovery ystems, hybrid systems, and full battery electric vehicles (EVs) and plugin hybrid vehicles. For the two last cases, the energy stored in the batteries will totally or partially come from the electric grid
Analyzing battery electric vehicle feasibility from taxi travel patterns: The case study of New York City, USA
Electric taxis have the potential to improve urban air quality and save driver’s energy expenditure. Although battery electric vehicles (BEVs) have drawbacks such as the limited range and charging inconvenience, technological progress has been presenting promising potential for electric taxis. Many cities around the world including New York City, USA are taking initiatives to replace gasoline taxis with plug-in electric vehicles. This paper extracts ten variables from the trip data of the New York City yellow taxis to represent their spatial-temporal travel patterns in terms of driver-shift, travel demand and dwell, and examines the implications of these driving patterns on the BEV taxi feasibility. The BEV feasibility of a taxi is quantified as the percentage of occupied trips that can be completed by BEVs of a given driving range during a year. It is found that the currently deployed 280 public charging stations in New York City are far from sufficient to support a large BEV taxi fleet. However, adding merely 372 new charging stations at various locations where taxis frequently dwell can potentially make BEVs with 200- and 300-mile ranges feasible for more than half of the taxi fleet. The results also show that taxis with certain characteristics are more suitable for switching to BEV-200 or BEV-300, such as fewer daily shifts, fewer drivers assigned to the taxi, shorter daily driving distance, fewer daily dwells but longer dwelling time, and higher likelihood to dwell at the borough of Manhattan
Battery capacity design for electric vehicles considering the diversity of daily vehicles miles traveled
In this paper, we study battery capacity design for battery electric vehicles (BEVs). The core of such design problems is to find a good tradeoff between minimizing the capacity to reduce financial costs of drivers and increasing the capacity to satisfy daily travel demands. The major difficulty of such design problems lies in modeling the diversity of daily travel demands. Based on massive trip records of taxi drivers in Beijing, we find that the daily vehicle miles traveled (DVMT) of a driver (e.g., a taxi driver) may change significantly in different days. This investigation triggers us to propose a mixture distribution model to describe the diversity in DVMT for various driver in different days, rather than the widely employed single distribution model. To demonstrate the merit of this new model, we consider value-at-risk and mean-variance battery capacity design problems for BEV, with respect to conventional single and new mixture distribution models of DVMT. Testing results indicate that the mixture distribution model better leads to better solutions to satisfy various drivers
Fear and loathing of electric vehicles: the reactionary rhetoric of range anxiety
“Range anxiety,” defined as the psychological anxiety a consumer experiences in response to the limited range of an electric vehicle, continues to be labelled and presented as one of the most pressing barriers to their mainstream diffusion. As a result, academia, policymakers and even industry have focused on addressing the range anxiety barrier in order to accelerate adoption. Much literature recognizes that range anxiety is increasingly psychological, rather than technical, in its nature. However, we argue in this paper that even psychological and technical explanations are incomplete. We examine range anxiety through Hirschman’s Rhetoric of Reaction, which supposes that conservative forces may oppose change by propagating theses related to jeopardy, perversity, and futility. To do so, we use three qualitative methods to understand the role of range anxiety triangulated via a variety of perspectives: 227 semi-structured interviews with experts at 201 institutions, a survey with nearly 5,000 respondents, and 8 focus groups, all across 17 cities in the five Nordic countries. We find evidence where consumers and experts use and perpetuate the rhetoric of reaction, particularly the jeopardy thesis. We conclude with a reexamination of the policies geared to assuage range-based barriers, which a construction of range anxiety as a rhetorical excuse would render as ineffective or inefficient, as well as future implications for diffusion theory
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