scholarly journals Progress Report on the Binary Pulsar 1913+16

1979 ◽  
Vol 32 (2) ◽  
pp. 35 ◽  
Author(s):  
LA Fowler ◽  
JM Cordes ◽  
JH Taylor

We report on the current status of observations of the binary pulsar PSRI913+16. The average pulse shape, polarization and spectrum have been found to be similar to those of other pulsars. We find no evidence for irregularities in the rotational frequency of the pulsar. With present measurement uncertainties, timing measurements after a few more years will yield estimates of the individual masses of the pulsar and its companion. the orbital inclination and the derivative of the orbital period. Upper limits on the last parameter are already inconsistent with theories that predict dipole gravitational waves; its measurement will test a specific prediction of general relativity theory and will indirectly demonstrate the existence of gravitational waves.

1989 ◽  
Vol 04 (09) ◽  
pp. 799-806 ◽  
Author(s):  
M. SIGNORE ◽  
N. SÁNCHEZ

We discuss the constraints on the stronger sources of the cosmological gravitational waves background detectable by millisecond pulsars—upper bounds on the cosmic string parameter Gµ, on the anisotropy Δ of the QCD transition phase and, on the dimensionless gravity wave energy. We derive also upper limits on the string parameter from the future binary pulsar timings and confront them with those imposed by current elementary particle phenomenology. We wait for future observations and for new experiments which either detect or place significant constraints on the existence of strings and long wavelength gravity waves—millisecond pulsar plus binary pulsar and the COBE cosmic 3 K anisotropy experiment.


2015 ◽  
Vol 39 ◽  
pp. 1560100
Author(s):  
Mario Vormstein

The NA48/2 and NA62 collaborations report on recent results, current status, and prospects of kaon physics at the CERN-SPS. The NA62 collaborations aims to measure the decay [Formula: see text] with an uncertainty of 10% or better. The NA62 detector and preliminary results from a pilot run in 2014 are presented. In addition, recent results of the NA48/2 collaboration are reported. A search for Dark Photons has been performed in [Formula: see text] decays via the kaon decays [Formula: see text] and [Formula: see text]. No dark photon signal was observed and new upper limits on the mixing parameter [Formula: see text] and the dark photon mass were computed. We also report the first observation of the kaon decay [Formula: see text].


Vision ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 38 ◽  
Author(s):  
Prasad ◽  
Mishra

Attentional selection in humans is mostly determined by what is important to them or by the saliency of the objects around them. How our visual and attentional system manage these various sources of attentional capture is one of the most intensely debated issues in cognitive psychology. Along with the traditional dichotomy of goal-driven and stimulus-driven theories, newer frameworks such as reward learning and selection history have been proposed as well to understand how a stimulus captures attention. However, surprisingly little is known about the different forms of attentional control by information that is not consciously accessible to us. In this article, we will review several studies that have examined attentional capture by subliminal cues. We will specifically focus on spatial cuing studies that have shown through response times and eye movements that subliminal cues can affect attentional selection. A majority of these studies have argued that attentional capture by subliminal cues is entirely automatic and stimulus-driven. We will evaluate their claims of automaticity and contrast them with a few other studies that have suggested that orienting to unconscious cues proceeds in a manner that is contingent with the top-down goals of the individual. Resolving this debate has consequences for understanding the depths and the limits of unconscious processing. It has implications for general theories of attentional selection as well. In this review, we aim to provide the current status of research in this domain and point out open questions and future directions.


1997 ◽  
Vol 9 ◽  
pp. 69-74 ◽  
Author(s):  
Robin Taylor

AbstractThere is a lack of experimental support for Linguistic Relativity Theory (LRT), which has not been tested in a South Pacific context. Fifty-two bilingual male (n = 26) and female Fijians read, and answered survey questions on the family dilemma, “An Unwanted Child?” - one group functioning in English and the other in Fijian. The group reading and answering in Fijian tended to place more emphasis on the rights of the extended family, whereas the group reading and responding in English placed more emphasis on the rights of the individual. These preliminary findings are consistent with LRT theory, and form the basis for more extended study, including perhaps a wider range of dilemmas and linguistic abilities (e.g., Fijians living in Australia).


Author(s):  
Linda Venis

This chapter presents a case study of how the UCLA Extension Writers’ Program, which is America’s largest continuing education provider of online creative writing and screenwriting courses and services, offers individualized feedback and mentoring to 1,000’s of aspiring and practicing writers worldwide. Writing creatively is singularly private and can be isolating; the Writers’ Program’s 220 annually-offered online courses in fiction writing, memoir, personal essay, children’s literature, playwriting, poetry, publishing, feature film writing, and television writing provide access to in-depth instructor/student, student/student, and student/advisor relationships designed to help meet individual writing goals. Writing education is particularly well-suited for online delivery because writers write: students submit their work in writing; the teacher and fellow students give their feedback in writing. For students, the act of learning to write online reinforces their accountability to create in a disciplined way and allows time to absorb and respond to critiques with reflection. For teachers, e-mentoring requires unusual rigor and preciseness in order to give thoughtful feedback on each piece of creative work, and the 80 professional writers who teach the Writers’ Program online courses employ a range of pedagogical strategies to do so. In addition, the Writers’ Program provides personalized guidance and advice on writing online through its student advisors as well as an array of services, including one-on-one manuscript and script consultations; feature film mentorships for which students sign up monthly and receive “on demand” guidance on their projects; and a first-of-its-kind course limited to six advanced students in which they hold virtual internships at production companies and studios as script readers. The chapter begins with an overview of UCLA Extension and the Writers’ Program’s history, mission, products, services, and managerial structure, and then describes the origins and current status of the Writers’ Program’s online curriculum and educational services. The ways in which writing education comprises a near-perfect match for a virtual delivery system are explored, followed by a discussion of what makes Writers’ Program’s products and services uniquely suited to deliver e-mentoring for a global, mostly post-baccalaureate student body who puts a high premium on results and quality of interaction. The chapter next outlines how clear expectations, course design, lectures and critiquing guidelines ensure successful response to creative work (instructor/student and student/peers), and then focuses on “best practices” techniques and strategies that online Writers’ Program instructors use to shape and deliver critiques, including a common critiquing vocabulary and methodology, use of technological tools to provide sustained, personalized feedback, and ways to cultivate the individual writer’s sense of place in the global literary and entertainment communities. The chapter concludes by addressing technological, pedagogical, and economic challenges and future directions of e-mentoring aspiring creative writers and screenwriters.


2005 ◽  
Vol 95 (22) ◽  
Author(s):  
B. Abbott ◽  
R. Abbott ◽  
R. Adhikari ◽  
J. Agresti ◽  
P. Ajith ◽  
...  

2017 ◽  
Vol 17 (20) ◽  
pp. 12341-12360 ◽  
Author(s):  
Mikhail Sofiev ◽  
Olga Ritenberga ◽  
Roberto Albertini ◽  
Joaquim Arteta ◽  
Jordina Belmonte ◽  
...  

Abstract. The paper presents the first modelling experiment of the European-scale olive pollen dispersion, analyses the quality of the predictions, and outlines the research needs. A 6-model strong ensemble of Copernicus Atmospheric Monitoring Service (CAMS) was run throughout the olive season of 2014, computing the olive pollen distribution. The simulations have been compared with observations in eight countries, which are members of the European Aeroallergen Network (EAN). Analysis was performed for individual models, the ensemble mean and median, and for a dynamically optimised combination of the ensemble members obtained via fusion of the model predictions with observations. The models, generally reproducing the olive season of 2014, showed noticeable deviations from both observations and each other. In particular, the season was reported to start too early by 8 days, but for some models the error mounted to almost 2 weeks. For the end of the season, the disagreement between the models and the observations varied from a nearly perfect match up to 2 weeks too late. A series of sensitivity studies carried out to understand the origin of the disagreements revealed the crucial role of ambient temperature and consistency of its representation by the meteorological models and heat-sum-based phenological model. In particular, a simple correction to the heat-sum threshold eliminated the shift of the start of the season but its validity in other years remains to be checked. The short-term features of the concentration time series were reproduced better, suggesting that the precipitation events and cold/warm spells, as well as the large-scale transport, were represented rather well. Ensemble averaging led to more robust results. The best skill scores were obtained with data fusion, which used the previous days' observations to identify the optimal weighting coefficients of the individual model forecasts. Such combinations were tested for the forecasting period up to 4 days and shown to remain nearly optimal throughout the whole period.


2020 ◽  
Author(s):  
Philippe de Reffye ◽  
Baogang Hu ◽  
Mengzhen Kang ◽  
Véronique Letort ◽  
Marc Jaeger

Abstract Background With up to 200 published contributions, the GreenLab mathematical model of plant growth, developed since 2000 under Sino-French co-operation for agronomic applications, is descended from the structural models developed in the AMAP unit that characterize the development of plants and encompass them in a conceptual mathematical framework. The model also incorporates widely recognized crop model concepts (thermal time, light use efficiency and light interception), adapting them to the level of the individual plant. Scope Such long-term research work calls for an overview at some point. That is the objective of this review paper, which retraces the main history of the model’s development and its current status, highlighting three aspects. (1) What are the key features of the GreenLab model? (2) How can the model be a guide for defining relevant measurement strategies and experimental protocols? (3) What kind of applications can such a model address? This last question is answered using case studies as illustrations, and through the Discussion. Conclusions The results obtained over several decades illustrate a key feature of the GreenLab model: owing to its concise mathematical formulation based on the factorization of plant structure, it comes along with dedicated methods and experimental protocols for its parameter estimation, in the deterministic or stochastic cases, at single-plant or population levels. Besides providing a reliable statistical framework, this intense and long-term research effort has provided new insights into the internal trophic regulations of many plant species and new guidelines for genetic improvement or optimization of crop systems.


1986 ◽  
Vol 7 ◽  
pp. 307-319
Author(s):  
R. B. Partridge

AbstractCrucial cosmological information is provided by the observed angular distribution (isotropy) of the cosmic microwave background radiation. This report treats the current status of searches for anisotroples in this radiation on all angular scales from 180° (the dipole component) to 6″. With the exception of the dipole component, only upper limits (at ~ 10-4 in ΔT/T) are available, yet these upper limits have played an important role in refining models of the early Universe and of the origin of structure within it.


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