365 research outputs found
A criminalização das drogas como fator limitante ao acesso à maconha medicinal
A maconha Ă© uma das substĂąncias classificadas como drogas pela Portaria SVS/MS 344/1998, cuja produção, comĂ©rcio e consumo sĂŁo severamente punidos no Ăąmbito da Lei 11.343/2006. Ao mesmo tempo, ela conta com dezenas de componentes (os chamados âcanabinoidesâ) com eficĂĄcia e segurança conhecida hĂĄ dĂ©cadas para o tratamento de vĂĄrias doenças, inclusive algumas consideradas refratĂĄrias, isto Ă©, resistentes aos tratamentos convencionais. Dessa forma, questiona-se como a criminalização das drogas tolhe o direito Ă saĂșde ao obstruir o acesso Ă maconha para fins medicinais. A hipĂłtese Ă© de que muitas dessas normas antidrogas sĂŁo inconstitucionais ao afrontar a dignidade da pessoa humana e os direitos fundamentais. A pesquisa foi bibliogrĂĄfica e documental e o mĂ©todo utilizado foi o hipotĂ©tico-dedutivo
Classic and spatial shift-share analysis of state-level employment change in Brazil
This paper combines classic and spatial shift-share decompositions of 1981 to 2006 employment change across the 27 states of Brazil. The classic shift-share method shows higher employment growth rates for underdeveloped regions that are due to an advantageous industry-mix and also due to additional job creation, commonly referred to as the competitive effect. Alternative decompositions proposed in the literature do not change this broad conclusion. Further examination employing exploratory spatial data analysis (ESDA) shows spatial correlation of both the industry-mix and the competitive effects. Considering that until the 1960s economic activities were more concentrated in southern regions of Brazil than they are nowadays, these results support beta convergence theories but also find evidence of agglomeration effects. Additionally, a very simple spatial decomposition is proposed that accounts for the spatially-weighted growth of surrounding states. Favourable growth in northern and centre-western states is basically associated with those statesâ strengths in potential spatial spillover effect and in spatial competitive effect
Business experience and start-up size: buying more lottery tickets next time around?
This paper explores the determinants of start-up size by focusing on a cohort of 6247 businesses that started trading in 2004, using a unique dataset on customer records at Barclays Bank. Quantile regressions show that prior business experience is significantly related with start-up size, as are a number of other variables such as age, education and bank account activity. Quantile treatment effects (QTE) estimates show similar results, with the effect of business experience on (log) start-up size being roughly constant across the quantiles. Prior personal business experience leads to an increase in expected start-up size of about 50%. Instrumental variable QTE estimates are even higher, although there are concerns about the validity of the instrument
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The distributed p-median problem in computer networks
Many distributed services in computer networks rely on a set of active facilities that are selected among
a potentially large number of candidates. The active facilities then contribute and cooperate to deliver a
specific service to the users of the distributed system. In this scenario graph partitioning or clustering is
often adopted to determine the most efficient locations of the facilities. The identification of the optimal
set of facility locations is known as the p-median problem in networks, is NP-hard and is typically solved
by using heuristic methods. The goal is to select p locations among all candidate network nodes such that
some cost function is minimised. A typical example of such a function is the overall communication cost
to deliver the service to the users of the distributed system. Locating facilities in near-optimal locations
has been extensively studied for different application domains. Most of these studies have investigated
sequential algorithms and centralised approaches. However, centralised approaches are practically infeasible
in large-scale and dynamic networks, where the problem is inherently distributed or because of the large
communication overhead and memory requirements for gathering complete information about the network
topology and the users. In this work distributed approaches to the p-median problem are investigated.
Two solutions are proposed for addressing the facility locations problem in a fully distributed environment.
Two different iterative heuristic approaches are applied to gradually improve a random initial solution
and to converge to a final solution with a local minimum of the overall cost. While the first approach
adopts a fine granularity by identifying a single change to improve the solution at each iteration, the second
approach applies changes to every component of the solution at each iteration. An experimental comparative
analysis based on simulations has shown that the approach with a finer granularity is able to deliver a better
optimisation of the overall cost with longer convergence time. Both approaches have excellent scalability
and provide an effective tool to optimise the facility locations from within the network. No prior knowledge
of the system is required, no data needs to be gathered in a centralised server and the same process is used
to identify and to deploy the facility locations solution in the network since the process is fully decentralised
Complex Adaptations Can Drive the Evolution of the Capacitor [PSI+], Even with Realistic Rates of Yeast Sex
The [PSI+] prion may enhance evolvability by revealing previously cryptic genetic variation, but it is unclear whether such evolvability properties could be favored by natural selection. Sex inhibits the evolution of other putative evolvability mechanisms, such as mutator alleles. This paper explores whether sex also prevents natural selection from favoring modifier alleles that facilitate [PSI+] formation. Sex may permit the spread of âcheaterâ alleles that acquire the benefits of [PSI+] through mating without incurring the cost of producing [PSI+] at times when it is not adaptive. Using recent quantitative estimates of the frequency of sex in Saccharomyces paradoxus, we calculate that natural selection for evolvability can drive the evolution of the [PSI+] system, so long as yeast populations occasionally require complex adaptations involving synergistic epistasis between two loci. If adaptations are always simple and require substitution at only a single locus, then the [PSI+] system is not favored by natural selection. Obligate sex might inhibit the evolution of [PSI+]-like systems in other species
Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV
The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of âs = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pTâ„20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60â€pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2â€{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration
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