La política antidrogas: nuevos horizontes de cambio en el control de la oferta y la demanda

96 p.De acuerdo con la Organización Mundial de la Salud (OMS, 1994) una sustancia o droga psicoactiva es aquella que, al ingerirse, afecta procesos mentales, como la cognición o la memoria. El término es asemejado generalmente con el de psicotrópico y ambas expresiones refieren al grupo de sustancias, legales e ilegales, de interés para la política en materia de drogas. En general, la literatura refiere con el término psicotrópico, a medicamentos utilizados principalmente en el tratamiento de los trastornos mentales, como los ansiolíticos, sedantes, antidepresivos, anti maníacos y neurolépticos. Bajo la categoría de sustancias psicotrópicas se encuentran los estupefacientes, acepción utilizada para referirse a sustancias cuya acción sedante, analgésica, narcótica y euforizante puede conducir al acostumbramiento y a la toxicomanía, por lo cual tienen un elevado potencial de abuso y / o dependencia psíquica/física. Entre ellos, se cuentan los estimulantes -cocaína, cafeína, nicotina-, los alucinógenos -Peyote y Psilocybes, los opiáceos -morfina, heroína-, y los sedantes/hipnóticos -alcohol- (OMS, 1994).Prólogo Introducción Capítulo 1. El panorama global: evolución reciente del fenómeno del consumo de sustancias psicoactivas Capítulo 2. La junta internacional de fiscalización de estupefacientes y la eficacia de la política antidrogas: el caso colombiano Capítulo 3. Hacia nuevos horizontes del análisis de política antidrogas Conclusiones Bibliografí

The "lessons" of the Australian "heroin shortage"

Heroin use causes considerable harm to individual users including dependence, fatal and nonfatal overdose, mental health problems, and blood borne virus transmission. It also adversely affects the community through drug dealing, property crime and reduced public amenity. During the mid to late 1990s in Australia the prevalence of heroin use increased as reflected in steeply rising overdose deaths. In January 2001, there were reports of an unpredicted and unprecedented reduction in heroin supply with an abrupt onset in all Australian jurisdictions. The shortage was most marked in New South Wales, the State with the largest heroin market, which saw increases in price, dramatic decreases in purity at the street level, and reductions in the ease with which injecting drug users reported being able to obtain the drug. The abrupt onset of the shortage and a subsequent dramatic reduction in overdose deaths prompted national debate about the causes of the shortage and later international debate about the policy significance of what has come to be called the "Australian heroin shortage". In this paper we summarise insights from four years' research into the causes, consequences and policy implications of the "heroin shortage"

A dynamical model for the penumbral fine structure and the Evershed effect in sunspots

Relying on the assumption that the interchange convection of magnetic flux tubes is the physical cause for the existence of sunspot penumbrae, we propose a model in which the dynamical evolution of a thin magnetic flux tube reproduces the Evershed effect and the penumbral fine structure such as bright and dark filaments and penumbral grains. According to our model, penumbral grains are the manifestation of the footpoints of magnetic flux tubes, along which hot subphotospheric plasma flows upwards with a few km/s. Above the photosphere the hot plasma inside the tube is cooled by radiative losses as it flows horizontally outwards. As long as the flowing plasma is hotter than the surroundings, it constitutes a bright radial filament. The flow confined to a thin elevated channel reaches the temperature equilibrium with the surrounding atmosphere and becomes optically thin near the outer edge of the penumbra. Here, the tube has a height of approximately 100 km above the continuum and the flow velocity reaches up to 14 km/s. Such a flow channel can reproduce the observed signatures of the Evershed effect.Comment: 5 pages, 2 figures, accepted for publication in ApJ letter

Unsung heroes: who supports social work students on placement?

Since the introduction of the three year degree programme in 2003, social work education has undergone a number of significant changes. The time students spend on placement has been increased to two hundred days, and the range of placement opportunities and the way in which these placements have been configured has significantly diversified. A consistent feature over the years, however, has been the presence of a Practice Educator (PE) who has guided, assessed and taught the student whilst on placement. Unsurprisingly, the role of the PE and the pivotal relationship they have with the student has been explored in the past and features in social work literature. This paper, however, concentrates on a range of other relationships which are of significance in providing support to students on placement. In particular it draws on research to discuss the role of the university contact tutor, the place of the wider team in which the student is sited, and the support offered by family, friends and others. Placements and the work undertaken by PE’s will continue to be integral to the delivery of social work education. It is, however, essential to recognise and value the often over looked role of others in providing support to students on placement

Identificação e clonagem de promotores raiz-específicos de eucalipto.

A utilização de promotores tecido - específicos é uma das principais estratégias para direcionar a expres são de transgenes a determinados órgãos ou tipos celulares . Por isso, o objetivo deste trabalho foi a clonagem de promotores raiz - específicos , a partir de dados de RNA - Seq obtidos de bibliotecas de raiz, xilema e folha de eucalipto. Dois genes com padrão d e expressão preferencial em raiz foram inicialmente selecionados para isolamento da região promotora. Fragmentos de 1kb foram clonados em vetor binário pCAMBIA2301, fusionados ao gene repórter da beta - glucuronidase (GUS) , para transformação de Populus trem ula x Populus alba via Agrobacterium tumefaciens .Edição dos anais do 3º Simpósio de Bioquímica e Biotecnologia, 2013. Londrina

Disintegration of Magnetic Flux in Decaying Sunspots as Observed with the Hinode SOT

Continuous observations of sunspot penumbrae with the Solar Optical Telescope aboard \textit{Hinode} clearly show that the outer boundary of the penumbra fluctuates around its averaged position. The penumbral outer boundary moves inward when granules appear in the outer penumbra. We discover that such granules appear one after another while moving magnetic features (MMFs) are separating from the penumbral ``spines'' (penumbral features that have stronger and more vertical fields than those of their surroundings). These granules that appear in the outer penumbra often merge with bright features inside the penumbra that move with the spines as they elongate toward the moat region. This suggests that convective motions around the penumbral outer boundary are related to the disintegration of magnetic flux in the sunspot. We also find that dark penumbral filaments frequently elongate into the moat region in the vicinity of MMFs that detach from penumbral spines. Such elongating dark penumbral filaments correspond to nearly horizontal fields extending from the penumbra. Pairs of MMFs with positive and negative polarities are sometimes observed along the elongating dark penumbral filaments. This strongly supports the notion that such elongating dark penumbral filaments have magnetic fields with a ``sea serpent''-like structure. Evershed flows, which are associated with the penumbral horizontal fields, may be related to the detachment of the MMFs from the penumbral spines, as well as to the formation of the MMFs along the dark penumbral filaments that elongate into the moat region.Comment: Accepted for publication in Ap

Ultrafast Electric Field-induced Phase Transition in Bulk Bi0.5Na0.5TiO3 under High Intensity Terahertz Irradiation

“This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Photonics, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acsphotonics.0c01559”Ultrafast polarization switching is being considered for the next generation of ferroelectric based devices. Recently, the dynamics of the field-induced transitions associated with this switching have been difficult to explore, due to technological limitations. The advent of terahertz (THz) technology has now allowed for the study of these dynamic processes on the picosecond (ps) scale. In this paper, intense terahertz (THz) pulses were used as a high-frequency electric field to investigate ultrafast switching in the relaxor ferroelectric, Bi0.5Na0.5TiO3. Transient atomic-scale responses, which were evident as changes in reflectivity, were captured by THz probing. The high energy THz pulses induce an increase in reflectivity, associated with an ultrafast field-induced phase transition from a weakly polar phase (Cc) to a strongly polar phase (R3c) within 20 ps at 200 K. This phase transition was confirmed using X-ray powder diffraction and by electrical measurements which showed a decrease in the frequency dispersion of relative permittivity at low frequencies