2,796 research outputs found
Marijuana on Main Streets? The Story Continues in Colombia: An Endogenous Three-part Model
Cannabis is the most common illicit drug, and understanding its demand is
relevant to analyze the potential implications of its legalization. This paper
proposes an endogenous three-part model taking into account incidental
truncation and access restrictions to study demand for marijuana in Colombia,
and analyze the potential effects of its legalization. Our application suggests
that modeling simultaneously access, intensive and extensive margin is
relevant, and that selection into access is important for the intensive margin.
We find that younger men that have consumed alcohol and cigarettes, living in a
neighborhood with drug suppliers, and friends that consume marijuana face
higher probability of having access and using this drug. In addition, we find
that marijuana is an inelastic good (-0.45 elasticity). Our results are robust
to different specifications and definitions. If marijuana were legalized,
younger individuals with a medium or low risk perception about marijuana use
would increase the probability of use in 3.8 percentage points, from 13.6% to
17.4%. Overall, legalization would increase the probability of consumption in
0.7 p.p. (2.3% to 3.0%). Different price settings suggest that annual tax
revenues fluctuate between USD 11.0 million and USD 54.2 million, a potential
benchmark is USD 32 million
Perturbations in the relaxation mechanism for a large cosmological constant
Recently, a mechanism for relaxing a large cosmological constant (CC) has
been proposed [arxiv:0902.2215], which permits solutions with low Hubble rates
at late times without fine-tuning. The setup is implemented in the LXCDM
framework, and we found a reasonable cosmological background evolution similar
to the LCDM model with a fine-tuned CC. In this work we analyse analytically
the perturbations in this relaxation model, and we show that their evolution is
also similar to the LCDM model, especially in the matter era. Some tracking
properties of the vacuum energy are discussed, too.Comment: 18 pages, LaTeX; discussion improved, accepted by CQ
High-density Au nanorod optical field-emitter arrays
We demonstrate the design, fabrication, characterization, and operation of high-density arrays of Au nanorod electron emitters, fabricated by high-resolution electron beam lithography, and excited by ultrafast femtosecond near-infrared radiation. Electron emission characteristic of multiphoton absorption has been observed at low laser fluence, as indicated by the power-law scaling of emission current with applied optical power. The onset of space-charge-limited current and strong optical field emission has been investigated so as to determine the mechanism of electron emission at high incident laser fluence. Laser-induced structural damage has been observed at applied optical fields above 5 GV m[superscript −1], and energy spectra of emitted electrons have been measured using an electron time-of-flight spectrometer.United States. Defense Advanced Research Projects Agency (Contract N66001-11-1-4192)Gordon and Betty Moore Foundatio
Effect of oat β-glucan on glycemic index and glycemic load of a nutritional supplement sweetened with sucralose in healthy adults: A randomized clinical trial
Indexación: Scopus; RedalycLas propiedades hipoglicemiantes del β-glucano de avena
son de interés para la industria alimentaria y el área clínica,
por sus potenciales beneficios sobre la salud al disminuir la
respuesta glicémica, el nivel sérico de lipoproteínas de baja
densidad y el índice glicémico de los alimentos. Existen suplementos
nutricionales específicos para diabéticos edulcorados
con sucralosa cuyo índice glicémico y carga glicémica
aún no han sido establecidos. El efecto del β-glucano de
avena sobre el índice glicémico y carga glicémica de un suplemento
nutricional edulcorado con sucralosa, fue determinado
en 13 adultos sanos (6 hombres y 7 mujeres), quienes
consumieron aleatoriamente 4 alimentos en días distintos, de
50 g de carbohidratos cada uno: suplemento nutricional para
diabéticos (FN), suplemento nutricional con β-glucano (FN-
β), y como productos de referencia: solución glucosada (SG)
y pan blanco (PB). Se midió glicemia en ayunas y post- prandial
a los tiempos 15, 30, 45, 60, 90 y 120 min. El área bajo
la curva de glicemia resultó más baja para ambas fórmulas
(FN) 12697±993, (FN-β) 11584 ±1171, que para los productos
de referencia:(SG) 13900±1245, y (PB) 13267 ± 1557.
Los valores de índice glicémico (FN) 67,02 ± 5,69, así como
la carga glicémica resultaron intermedios y más bajos para el
suplemento con β-glucano incorporado (FN –β) 59,8 ± 6,2;
sin diferencias en la concentración de insulina, sugiriendo
que la adición del β-glucano derivado de la avena reduce la
velocidad de absorción intestinal de la glucosa, efecto que
podría estudiarse en diabéticos.The hypoglycemic properties of oat β-glucan is of interest
for the food industry and clinical area, for potencial health
benefits by reducing glycemic response, serum low-density
lipoprotein cholesterol, and glycemic index of meals. There
are specific nutritional supplements for diabetics sweetened
with sucralose whose glycemic index and glycemic load has
not been established. Effect of oat β-glucan on glycemic
index and glycemic load of a nutritional supplement sweetened
with sucralose in healthy adults was determined in 13
healthy subjects (6 men and 7 women) old that consumed
randomly 4 meals of 50 g of carbohydrates each in different
days: a nutritional supplement for diabetics (FN), the nutritional
supplement with β-glucan incorporated (FN-β) and two
reference food, glucose solution (SG) and white bread (PB).
Fasting and postprandial glycemia was measured at times
15, 30, 45, 60, 90 and 120 min. The area under the glycemia
curve was lower for both formulas (FN) 12697±993, (FN-β)
11584 ±1171 than for reference products (SG) 13900±1245,
y (PB) 13267 ± 1557. The values of glycemic index (GI) (FN)
67, 02 ± 5,69 and glycemic load were intermediate and more
lower for the supplement with β-glucan incorporated (FN –β)
59, 8 ± 6,2, with no difference of insulin concentration . Suggesting
that the addition of oat-derived β-glucan reduces the
rate of intestinal absorption of glucose. This effect should be
studied in diabetic.http://www.redalyc.org/articulo.oa?id=5594990800
Pregnant women's responses to a tailored smoking cessation intervention: turning hopelessness into competence
Background: Cognitive behavioral interventions consisting of brief counseling and the provision of self-help material designed for pregnancy have been documented as effective smoking cessation interventions for pregnant women. However, there is a need to understand how such interventions are perceived by the targeted group. Aim: To understand the cognitive, emotional, and behavioral responses of pregnant women to a clinic-based smoking cessation intervention. Methods: In-depth interviews with women attending four antenatal clinics in Cape Town, South Africa, who were exposed to a smoking intervention delivered by midwives and peer counselors. Women were purposively selected to represent a variation in smoking behavior. Thirteen women were interviewed at their first antenatal visit and 10 were followed up and reinterviewed later in their pregnancies. A content analysis approach was used, which resulted in categories and themes describing women's experiences, thoughts, and feelings about the intervention. Results: Five women quit, five had cut down, and three could not be traced for follow-up. All informants perceived the intervention positively. Four main themes captured the intervention's role in influencing women's smoking behavior. The process started with ‘understanding their reality,’ which led to ‘embracing change’ and ‘deciding to hold nothing back,’ which created a basis for ‘turning hopelessness into a feeling of competence.’Conclusion: The intervention succeeded in shifting women from feeling pessimistic about ever quitting to feeling encouraged to try and quit. Informants rated the social support they received very highly and expressed the need for the intervention to become a routine component of clinic services
Transverse sphericity of primary charged particles in minimum bias proton-proton collisions at , 2.76 and 7 TeV
Measurements of the sphericity of primary charged particles in minimum bias
proton--proton collisions at , 2.76 and 7 TeV with the ALICE
detector at the LHC are presented. The observable is linearized to be collinear
safe and is measured in the plane perpendicular to the beam direction using
primary charged tracks with GeV/c in . The
mean sphericity as a function of the charged particle multiplicity at
mid-rapidity () is reported for events with different
scales ("soft" and "hard") defined by the transverse momentum of the leading
particle. In addition, the mean charged particle transverse momentum versus
multiplicity is presented for the different event classes, and the sphericity
distributions in bins of multiplicity are presented. The data are compared with
calculations of standard Monte Carlo event generators. The transverse
sphericity is found to grow with multiplicity at all collision energies, with a
steeper rise at low , whereas the event generators show the
opposite tendency. The combined study of the sphericity and the mean with multiplicity indicates that most of the tested event generators
produce events with higher multiplicity by generating more back-to-back jets
resulting in decreased sphericity (and isotropy). The PYTHIA6 generator with
tune PERUGIA-2011 exhibits a noticeable improvement in describing the data,
compared to the other tested generators.Comment: 21 pages, 9 captioned figures, 3 tables, authors from page 16,
published version, figures from
http://aliceinfo.cern.ch/ArtSubmission/node/308
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
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