18,868 research outputs found
Series of broad resonances in atomic three-body systems
We re-examine the series of resonances found earlier in atomic three-body
systems by solving the Faddeev-Merkuriev integral equations. These resonances
are rather broad and line-up at each threshold with gradually increasing gaps,
the same way for all thresholds and irrespective of the spatial symmetry. We
relate these resonances to the Gailitis mechanism, which is a consequence of
the polarization potential.Comment: 14 pages, 7 figures. arXiv admin note: text overlap with
arXiv:0810.303
Recommended from our members
Teacher perception of the instructional evaluation process : an exploratory study.
This study is motivated by the fact that pedagogy has become a major political issue in this decade. State and Federal Governments, Boards of Education, School Systems, and Educators at all levels are trying to come up with strategies to put education on the right track and to recapture the interest of young people. Financial problems, drugs, lack of interest from parents and students, and poorly motivated personnel, may be some of the factors affecting the teaching process in school environment resulting in the lowering of the quality of instruction. Among the factors that might be affecting the teaching process in the schools are poorly motivated instructional personnel, who play so important a role in creating a successful school environment. If a teacher is not well motivated, student achievement will be negatively affected and the schools can still fail. Even if one works in a new building with modern facilities, with the best instructional materials, selected students, flexible schedules, is fairly well paid, and has competent colleagues, there are no guarantees of success if teacher motivation is low. If a supervisor detects that the staff is not well motivated for whatever reason, a solution must be found. Through this study, I reviewed various styles of supervision that instructional supervisors can use as models for assessing classroom teachers. The study focused on five of the most common models used in different school districts within the state. (1) Cooperative Supervision; (2) Self-directed Supervision; (3) Clinical Supervision; (4) Oriented Monitoring; (5) Differentiated Supervision. The study was conducted among teachers in a Western Massachusetts Public School System. A questionnaire was administered to collect the data. The collected data answered the following questions: (1) Is the teacher evaluation process contributing to the teaching-learning process in the classroom? (2) Are supervisors providing information about the options that teachers have to be evaluated? A theoretical model based on Clinical Supervision and Administrative Monitoring was prepared by the researcher as an instrument that supervisors can use to evaluate teacher effectiveness
Social Marketing in Action
This book was written for those interested in creating social change for the greater good.
In this book, we provide a wide selection of social marketing cases from which we can
learn and teach. The book is intended for both academic and practitioner use. Part I of
this book offers a brief yet comprehensive review of social marketing. This provides the
reader with the background in social change and marketing necessary to read and
analyze the subsequent cases. Parts II, III, IV, and V of this book offer a total of 24
social marketing cases, from a variety of countries, addressing many different issues.
For classroom use, this book is written to serve as a stand-alone tool, with Part I
providing a concise introduction to social marketing principles and theory. Chapter
appendices provide links to further readings on social marketing principles for those
wishing to delve deeper. If still further detail on social marketing principles and
theory are desired, this book can easily be paired with another social marketing
textbook as well. We have aimed the book to be accessible to undergraduate students
but also offer sufficient material to challenge students at the graduate level. Advanced
students should be encouraged to further explore the references and links provided, to
critique the case approaches, and to offer alternative strategies for the cases provided.
A separate teaching guide collection is available for the book as well. This collection
contains answers to the discussion questions in the cases, as well as suggested
activities for inside and outside of the classroom. Additionally, the teaching guides
for many cases offer suggestions for further reading and other helpful resources.
For practitioner use, Part I offers a refresher on basic social marketing principles. In
addition, a variety of references are offered, allowing for further personal study. Parts II
through V offer detailed information about a wide variety of actual social marketing
programs. You can compare and contrast these cases with your own situation, hopefully
gaining insights that will be helpful in your own social marketing efforts
Non-conventional digital signatures and their implementations – A review
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-19713-5_36The current technological scenario determines a profileration
of trust domains, which are usually defined by validating the digital
identity linked to each user. This validation entails critical assumptions
about the way users’ privacy is handled, and this calls for new methods
to construct and treat digital identities. Considering cryptography,
identity management has been constructed and managed through conventional
digital signatures. Nowadays, new types of digital signatures
are required, and this transition should be guided by rigorous evaluation
of the theoretical basis, but also by the selection of properly verified software
means. This latter point is the core of this paper. We analyse the
main non-conventional digital signatures that could endorse an adequate
tradeoff betweeen security and privacy. This discussion is focused on
practical software solutions that are already implemented and available
online. The goal is to help security system designers to discern identity
management functionalities through standard cryptographic software libraries.This work was supported by Comunidad de Madrid (Spain) under the project S2013/ICE-3095-CM (CIBERDINE) and the Spanish Government project TIN2010-19607
Extreme Galactic-Winds and Starburst in IR Mergers and IR QSOs
We report -as a part of a long-term study of mergers and IR QSOs- detailed
spectroscopic evidences for outflow (OF) and/or Wolf Rayet features in: (i) low
velocity OF in the ongoing mergers NGC 4038/39 and IRAS 23128-5919; (ii)
extreme velocity OF (EVOF) in the QSOs IRAS 01003-2238 and IRAS 13218+0552;
(iii) OF and EVOF in a complete sample of ultra-luminous IR galaxies/QSOs ("The
IRAS 1 Jy MKO-KPNO Survey", of 118 objects). We found EVOF in IRAS 11119+3257,
14394+5332, 15130+1958 and 15462-0450. The OF components detected in these
objects were mainly associated to starburst processes: i.e., to galactic-winds
generated in multiple type II SN explosions and massive stars. The EVOF were
detected in objects with strong starburst plus obscured IR QSOs; which suggest
that interaction of both processes could generate EVOF. In addition, we analyze
the presence of Wolf Rayet features in the large sample of Bright PG-QSOs
(Boroson and Green 1992), and nearby mergers and galactic-wind galaxies. We
found clear WR features in the Fe II QSOs (type I): PG 1244+026, 1444+407,
1448+273, 1535+547; and in the IR merger Arp 220. HST archive images of IR+BAL
QSOs show in practically all of these objects "arc or shell" features probably
associated to galactic-winds (i.e., to multiple type II SN explosions) and/or
merger processes. Finally, we discuss the presence of extreme starburst and
galactic wind as a possible evolutive link between IR merger and IR QSOs; where
the relation between mergers and extreme starburst (with powerful
galactic-winds) plays in important role, in the evolution of galaxies.Comment: 14 pages, 6 figure
The critical current of YBa2Cu3O7-d Low Angle Grain Boundaries
Transport critical current measurements have been performed on 5 degree
[001]-tilt thin film YBa2Cu3O7-delta single grain boundaries with magnetic
field rotated in the plane of the film, phi. The variation of the critical
current has been determined as a function of the angle between the magnetic
field and the grain boundary plane. In applied fields above 1 T the critical
current, j_c, is found to be strongly suppressed only when the magnetic field
is within an angle phi_k of the grain boundary. Outside this angular range the
behavior of the artificial grain boundary is dominated by the critical current
of the grains. We show that the phi dependence of j_c in the suppressed region
is well described by a flux cutting model.Comment: To be published in PRL, new version with minor changes following
referees report
Sleep Apnea – Recent Updates
Sleep apnea is highly prevalent and underdiagnosed. It is associated with multiple medical conditions including cardiac dysrhythmia, stroke, hypertension, diabetes and congestive heart failure. In the last few decades, advances in diagnosis and treatment of sleep apnea have been robust. In this review, we will emphasize primarily developments in the area of sleep apnea that occurred in the past 5 years. These include changes in the nomenclature of sleep apnea in the International Classification in Sleep Disorders (ICSD)-3, physiologic approach of treating sleep apnea, eligibility for CPAP (continuous positive airway pressure) treatment, home sleep testing (HST), sleep apnea in pregnancy, updates in oral device treatment and other emerging concepts on sleep apnea
- …