10,580 research outputs found
Some theoretical and methodological comments on the impact of policies on fertility
Theoretically, and for reasons that I will shortly summarise in this presentation, there are strong reasons to expect policies to have a positive impact on fertility. Empirically, however, the evidence regarding the potential impact of policies of fertility is less clear cut. While numerous studies do indeed show a positive impact of policies, there is no consensus regarding the actual magnitude of the impact, nor about its short- or medium-term nature (Gauthier 2007). What I want to do in this presentation is consequently to reflect on the results from empirical studies by raising a number of theoretical and methodological issues.
Nouvelles estimations du coĂ»t de lâenfant au Canada
Afin de pouvoir Ă©valuer le degrĂ© auquel les politiques gouvernementales dâaide et de soutien aux familles compensent les coĂ»ts Ă©conomiques reliĂ©s Ă la prise en charge dâun enfant, il importe de disposer dâune estimation du coĂ»t de lâenfant. Dans cet article, lâauteur prĂ©sente un nouveau modĂšle dâestimation de ce coĂ»t, et lâapplique aux donnĂ©es de lâenquĂȘte de Statistique Canada sur les dĂ©penses des familles en 1982. La premiĂšre partie dĂ©crit les dĂ©veloppements mĂ©thodologiques et thĂ©oriques ayant permis lâobtention de ce modĂšle, et la deuxiĂšme analyse les estimations du coĂ»t de lâenfant selon son Ăąge et son rang, pour des familles de niveaux de vie diffĂ©rents.In order to be able to appraise to what extent policy measures compensate for the cost of rearing a child, one needs an estimate of this cost. In this paper, the author presents a new model which is applied to data obtained from the survey of family expenditures, made in 1982 by Statistics Canada. The first part is devoted to the methodological and theoretical considerations on which the model is based, and the second part analyses the estimates of the cost of a child, according to age and rank of the child, and standard of living of the family.A fin de poder evaluar el grado en el cual las polĂticas governementales de ayuda y sostĂ©n a las familias compensan los costos econĂłmicos relacionados a la toma en cargo de un niño es importante disponer de una estimaciĂłn de su costo. En este artĂculo, el autor presenta un nuevo modelo de estimaciĂłn del costo y lo aplica a los datos de la encuesta de EstadĂsticas Canada sobre los gastos de las familias en 1982. La primera parte describe los desarrollos metodolĂłgicos y teĂłricos que han permitido el logro de este modelo y la segunda analiza las estimaciones del costo del niño segun su edad y su rango para las familias de distintos niveles de vida
A Kaluza-Klein Model with Spontaneous Symmetry Breaking: Light-Particle Effective Action and its Compactification Scale Dependence
We investigate decoupling of heavy Kaluza-Klein modes in an Abelian Higgs
model with space-time topologies and
. After integrating out heavy KK
modes we find the effective action for the zero mode fields. We find that in
the topology the heavy modes do not decouple in
the effective action, due to the zero mode of the 5-th component of the 5-d
gauge field . Because is a scalar under 4-d Lorentz
transformations, there is no gauge symmetry protecting it from getting mass and
interaction terms after loop corrections. In addition, after
symmetry breaking, we find new divergences in the mass that did not
appear in the symmetric phase. The new divergences are traced back to the
gauge-goldstone mixing that occurs after symmetry breaking. The relevance of
these new divergences to Symanzik's theorem is discussed. In order to get a
more sensible theory we investigate the
compactification. With this kind of compact topology, the zero mode
disappears. With no , there are no new divergences and the heavy modes
decouple. We also discuss the dependence of the couplings and masses on the
compactification scale. We derive a set of RG-like equations for the running of
the effective couplings with respect to the compactification scale. It is found
that magnitudes of both couplings decrease as the scale increases. The
effective masses are also shown to decrease with increasing compactification
scale. All of this opens up the possibility of placing constraints on the size
of extra dimensions.Comment: 35 pages, 6 figure
Supersymmetric free-damped oscillators: Adaptive observer estimation of the Riccati parameter
A supersymmetric class of free damped oscillators with three parameters has
been obtained in 1998 by Rosu and Reyes through the factorization of the Newton
equation. The supplementary parameter is the integration constant of the
general Riccati solution. The estimation of the latter parameter is performed
here by employing the recent adaptive observer scheme of Besancon et al., but
applied in a nonstandard form in which a time-varying quantity containing the
unknown Riccati parameter is estimated first. Results of computer simulations
are presented to illustrate the good feasibility of this approach for a case in
which the estimation is not easily accomplished by other meansComment: 8 pages, 6 figure
Direct imaging of a digital-micromirror device for configurable microscopic optical potentials
Programable spatial light modulators (SLMs) have significantly advanced the
configurable optical trapping of particles. Typically, these devices are
utilized in the Fourier plane of an optical system, but direct imaging of an
amplitude pattern can potentially result in increased simplicity and
computational speed. Here we demonstrate high-resolution direct imaging of a
digital micromirror device (DMD) at high numerical apertures (NA), which we
apply to the optical trapping of a Bose-Einstein condensate (BEC). We utilise a
(1200 x 1920) pixel DMD and commercially available 0.45 NA microscope
objectives, finding that atoms confined in a hybrid optical/magnetic or
all-optical potential can be patterned using repulsive blue-detuned (532 nm)
light with 630(10) nm full-width at half-maximum (FWHM) resolution, within 5%
of the diffraction limit. The result is near arbitrary control of the density
the BEC without the need for expensive custom optics. We also introduce the
technique of time-averaged DMD potentials, demonstrating the ability to produce
multiple grayscale levels with minimal heating of the atomic cloud, by
utilising the high switching speed (20 kHz maximum) of the DMD. These
techniques will enable the realization and control of diverse optical
potentials for superfluid dynamics and atomtronics applications with quantum
gases. The performance of this system in a direct imaging configuration has
wider application for optical trapping at non-trivial NAs.Comment: 9 page
Strongly correlated photons generated by coupling a three- or four-level system to a waveguide
We study the generation of strongly correlated photons by coupling an atom to
photonic quantum fields in a one-dimensional waveguide. Specifically, we
consider a three-level or four-level system for the atom. Photon-photon bound
states emerge as a manifestation of the strong photon-photon correlation
mediated by the atom. Effective repulsive or attractive interaction between
photons can be produced, causing either suppressed multiphoton transmission
(photon blockade) or enhanced multiphoton transmission (photon-induced
tunneling). As a result, nonclassical light sources can be generated on demand
by sending coherent states into the proposed system. We calculate the
second-order correlation function of the transmitted field and observe bunching
and antibunching caused by the bound states. Furthermore, we demonstrate that
the proposed system can produce photon pairs with a high degree of spectral
entanglement, which have a large capacity for carrying information and are
important for large-alphabet quantum communication.Comment: 13+ pages, 7 figure
Hypothermia associated with clobazam use in adult epilepsy
AbstractClobazam, a 1,5-benzodiazepine FDA-approved in 2011, is commonly used to treat anxiety and epilepsy. It has not been associated with hypothermia until very recently, in a case report involving two pediatric patients. Here, we report the first case of hypothermia development in an adult patient with epilepsy associated with clobazam use. A couple months after starting clobazam, the patient started developing episodes of hypothermia every several weeks, with temperatures ranging from 90°Fâ95°F. Normothermia was achieved with Bair Hugger therapy. Thyroid-stimulating hormone and cortisol levels were normal, and there was no evidence of infection in most instances. After 11 total episodes of hypothermia over a year of clobazam use, the drug was discontinued. It has now been 7months after discontinuation, and the patient has not experienced any more episodes of hypothermia. Early recognition of the link between clobazam and hypothermia may prevent avoidable Emergency Department visits and hospitalizations
All-Optical Switching with Transverse Optical Patterns
We demonstrate an all-optical switch that operates at ultra-low-light levels
and exhibits several features necessary for use in optical switching networks.
An input switching beam, wavelength , with an energy density of
photons per optical cross section [] changes
the orientation of a two-spot pattern generated via parametric instability in
warm rubidium vapor. The instability is induced with less than 1 mW of total
pump power and generates several Ws of output light. The switch is
cascadable: the device output is capable of driving multiple inputs, and
exhibits transistor-like signal-level restoration with both saturated and
intermediate response regimes. Additionally, the system requires an input power
proportional to the inverse of the response time, which suggests thermal
dissipation does not necessarily limit the practicality of optical logic
devices
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