12,253 research outputs found
New species of New World Tambiniini from palms: (Hemiptera: Fulgoroidea, Tropiduchidae)
Eine neue Gattung und Art, Diambon remanei nov. gen. nov. spec. aus Trinidad sowie zwei neue Arten der Gattung Athestia Melichar, 1914, A. excelsa nov. spec. aus Mexico und A. aschei nov. spec. aus Argentinien werden beschrieben. Biruga Fennah, 1944 wird mit ihrer Typusart B. chapada wieder errichtet. Die Gattung Athestia wird wiederbeschrieben. Ein Schlüssel der Tambiniini der Neuen Welt wird präsentiert. Alle neu beschriebenen Arten wurden von Palmen gesammelt.One new genus and species, Diambon remanei nov gen. nov. spec. from Trinidad and two new species of Athestia Melichar, 1914, A. excelsa nov. spec. from Mexico and A. aschei nov. spec. from Argentina, are described and illustrated. Biruga Fennah, 1944 is resurrected with its type-species B. chapadae. The genus Athestia is redescribed, and the genera and species of New World Tambiniini are keyed. All of the new species were collected from palms
Reasonable responses versus proportionality in employee dismissal cases: A comparison between the Employment Rights Act 1996, s 98(4) and the Equality Act 2010, s 13(2), s 15(1)(b), and s 19(2)(d).
What, if any, are the differences between a dismissal that is reasonable and one that is a proportionate means of achieving a legitimate aim? That is the question at the centre of this dissertation. To answer it we start by placing both legal tests within the overall context of statute, then assess and analyse both separately. From that point the two can be fully compared. The structure of this dissertation is thus as follows: Chapter one outlines statutory provisions regulating dismissal from employment in both the Employment Rights Act 1996 (ERA) and Equality Act 2010 (EqA). It identifies the key role of section 98(4) of the ERA in deciding unfair dismissal claims; and the likewise key roles of sections 13(2), 15(1)(b), and 19(2)(d) of the EqA in deciding some categories of discrimination claim. Chapter two examines the application of ERA s 98(4) in depth to identify its interpretation, its impact on claimants and employers, and the likelihood of future legal developments in this area. Chapter three carries out a similar exercise for sections 13(2), 15(1)(b), and 19(2)(d) of the EqA. Having identified the central concepts of reasonable responses and proportionality, chapter four compares them directly. It focuses particularly on dual claim situations where both tests are necessarily applied side by side to the same facts. Overall conclusions are made about both differences and similarities found. It is argued that the relationship between reasonableness and proportionality in cases of employee dismissal is not fully settled within case law, and further clarification will likely be necessary in the future. Such clarification could go to the heart of distinctions between unfair dismissal and discrimination in UK law
Outer zone electrons
Spatial and temporal behavior of high energy trapped electrons in outer zone of magnetospher
Dynamics of the Lyman alpha and C IV emitting gas in 3C 273
In this paper we study the variability properties of the Lyman alpha and C IV
emission lines in 3C273 using archival IUE observations. Our data show for the
first time the existence of variability on time scales of several years. We
study the spatial distribution and the velocity field of the emitting gas by
performing detailed analyses on the line variability using correlations, 1D and
2D response functions, and principal component analysis. In both lines we find
evidence for two components, one which has the dynamic properties of gas in
Keplerian motion around a black hole with a mass of the order of 10^9 Mo, and
one which is characterized by high, blue-shifted velocities at large lag. There
is no indication of the presence of optically thick emission medium neither in
the Lya, nor in the Civ response functions. The component characterized by
blue-shifted velocities, which is comparatively much stronger in Civ than in
Lya, is more or less compatible with being the result of gas falling towards
the central black hole with free-fall acceleration. We propose however that the
line emission at high, blue-shifted velocities is better explained in terms of
entrainment of gas clouds by the jet. This gas is therefore probably
collisionally excited as a result of heating due to the intense infrared
radiation from the jet, which would explain the strength of this component in
Civ relative to Lya. This phenomenon might be a signature of disk-jet
interaction.Comment: 16 pages, 10 figures. Accepted for publication in ApJ. Uses aaste
Spectral Properties From Lyman-alpha to H-alpha For An Essentially Complete Sample of Quasars I: Data
We have obtained quasi-simultaneous ultraviolet-optical spectra for 22 out of
23 quasars in the complete PG-X-ray sample with redshift, z<0.4, and M_B<-23.
The spectra cover rest-frame wavelengths from at least Lyman-alpha to H-alpha.
Here we provide a detailed description of the data, including careful
spectrophotometry and redshift determination. We also present direct
measurements of the continua, strong emission lines and features, including
Lyman-alpha, SiIV+OIV], CIV, CIII], SiIII], MgII, H-beta, [OIII],
He5876+NaI5890,5896, H-alpha, and blended iron emission in the UV and optical.
The widths, asymmetries and velocity shifts of profiles of strong emission
lines show that CIV and Lyman-alpha are very different from H-beta and H-alpha.
This suggests that the motion of the broad line region is related to the
ionization structure, but the data appears not agree with the radially
stratified ionization structure supported by reverberation mapping studies, and
therefore suggest that outflows contribute additional velocity components to
the broad emission line profiles.Comment: 42 pages, 10 figures, 13 tables. Accepted by AJ. Supplemental figures
not included. Full version available at
http://physics.uwyo.edu/~shang/pgxpaper/ShangPaper.pd
Exact zero-point energy shift in the , many modes dynamic Jahn-Teller systems at strong coupling
We find the exact semiclassical (strong coupling) zero-point energy shifts
applicable to the and dynamic Jahn-Teller
problems, for an arbitrary number of discrete vibrational modes
simultaneously coupled to one single electronic level. We also obtain an
analytical formula for the frequency of the resulting normal modes, which has
an attractive and apparently general Slater-Koster form. The limits of validity
of this approach are assessed by comparison with O'Brien's previous
effective-mode approach, and with accurate numerical diagonalizations.
Numerical values obtained for with and coupling
constants appropriate to C are used for this purpose, and are
discussed in the context of fullerene.Comment: 20 pages, 4 ps figure
Unsolicited written narratives as a methodological genre in terminal illness: challenges and limitations
Stories about illness have proven invaluable in helping health professionals understand illness experiences. Such narratives have traditionally been solicited by researchers through interviews and the collection of personal writings, including diaries. These approaches are, however, researcher driven; the impetus for the creation of the story comes from the researcher and not the narrator. In recent years there has been exponential growth in illness narratives created by individuals, of their own volition, and made available for others to read in print or as Internet accounts. We sought to determine whether it was possible to identify such material for use as research data to explore the subject of living with the terminal illness amyotrophic lateral sclerosis/motor neuron disease—the contention being that these accounts are narrator driven and therefore focus on issues of greatest importance to the affected person. We encountered and sought to overcome a number of methodological and ethical challenges, which is our focus here
The Extent and Cause of the Pre-White Dwarf Instability Strip
One of the least understood aspects of white dwarf evolution is the process
by which they are formed. We are aided, however, by the fact that many H- and
He-deficient pre-white dwarfs (PWDs) are multiperiodic g-mode pulsators.
Pulsations in PWDs provide a unique opportunity to probe their interiors, which
are otherwise inaccesible to direct observation. Until now, however, the nature
of the pulsation mechanism, the precise boundaries of the instability strip,
and the mass distribution of the PWDs were complete mysteries. These problems
must be addressed before we can apply knowledge of pulsating PWDs to improve
understanding of white dwarf formation. This paper lays the groundwork for
future theoretical investigations of these stars. In recent years, Whole Earth
Telescope observations led to determination of mass and luminosity for the
majority of the (non-central star) PWD pulsators. With these observations, we
identify the common properties and trends PWDs exhibit as a class. We find that
pulsators of low mass have higher luminosity, suggesting the range of
instability is highly mass-dependent. The observed trend of decreasing periods
with decreasing luminosity matches a decrease in the maximum (standing-wave)
g-mode period across the instability strip. We show that the red edge can be
caused by the lengthening of the driving timescale beyond the maximum
sustainable period. This result is general for ionization-based driving
mechanisms, and it explains the mass-dependence of the red edge. The observed
form of the mass-dependence provides a vital starting point for future
theoretical investigations of the driving mechanism. We also show that the blue
edge probably remains undetected because of selection effects arising from
rapid evolution.Comment: 40 pages, 6 figures, accepted by ApJ Oct 27, 199
Soft OR and practice : the contribution of the founders of Operation Research
This paper explores the work of some 43 founders of operations research. In particular, it considers the links between soft operations research (OR) and these founders. Several of the founders were direct influencers of the soft OR proponents, whereas others related to the context, process, and content of soft OR. Coupled with the deductive and inductive reasoning approaches of soft OR, it is argued that soft OR is a legitimate branch of OR. The paper also focuses on the embeddedness of the founders, and the soft OR proponents, in practice and argues that, for academics, engagement with practice has been and will continue to be an important driver for the health and development of operations research
Optimal search strategies for hidden targets
What is the fastest way of finding a randomly hidden target? This question of
general relevance is of vital importance for foraging animals. Experimental
observations reveal that the search behaviour of foragers is generally
intermittent: active search phases randomly alternate with phases of fast
ballistic motion. In this letter, we study the efficiency of this type of two
states search strategies, by calculating analytically the mean first passage
time at the target. We model the perception mecanism involved in the active
search phase by a diffusive process. In this framework, we show that the search
strategy is optimal when the average duration of "motion phases" varies like
the power either 3/5 or 2/3 of the average duration of "search phases",
depending on the regime. This scaling accounts for experimental data over a
wide range of species, which suggests that the kinetics of search trajectories
is a determining factor optimized by foragers and that the perception activity
is adequately described by a diffusion process.Comment: 4 pages, 5 figures. to appear in Phys. Rev. Let
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