2,132 research outputs found
Mules or Couriers: The Role of Nigerian Drug Couriers in the International Drug Trade
Nigerian drug couriers - their recrutiment, integration with the drugs market and the impact of arrest and incarceration
Drug Policy and the HIV Pandemic in Russia and Ukraine
Over the past three years Russia and Ukraine have experienced one of the fastest growing HIV pandemics in Europe. In contrast to other parts of the world, the main driver behind the rate of infection is injecting drug use. Recent government policies have placed a heavy emphasis on reducing availability and on harsh punishments for drug users. This approach has not succeeded in significantly reducing the level of drug use. It has pushed the drug scene underground and increased risky behaviours among vulnerable groups. In the absence of measures to reduce infections and reverse the rate of transmission,
the long-term impact of HIV/AIDS on population growth and economic development is likely to be grave
Regulating khat - Dilemmas and opportunities for the international drug control system
Background: The regulation of khat, one of the most recent psychoactive drugs to become a globally traded commodity, remains hotly contested within different producer and consumer countries. As regimes vary, it has been possible to compare khat policies in Africa, Europe and North America from different disciplinary perspectives.
Methods: Field research was conducted in East Africa and Europe, using a combination of semistructured interviews, participant observation and the analysis of trade statistics.
Results: The research established the significance of khat for rural producers, regional economies, as a tax base and source of foreign exchange. At the same time, khat as a psychoactive substance is associated with health and public safety problems that in turn are met with often ill-informed legislative responses. Bans have in turn lead to the criminalisation of users and sellers and illegal drug markets.
Conclusion: The empirical work from Africa provides a strong argument for promoting evidence-based approaches to khat regulation, harnessing the positive aspects of the khat economy to develop a control model that incorporates the voices and respects the needs of rural producers. Ultimately, the framework for khat may provide both a model and an opportunity for revising the international treaties governing the control of other plant psychoactive-based substances
Probing the dynamical and X-ray mass proxies of the cluster of galaxies Abell S1101
Context: The galaxy cluster Abell S1101 (S1101 hereafter) deviates
significantly from the X-ray luminosity versus velocity dispersion relation
(L-sigma) of galaxy clusters in our previous study. Given reliable X-ray
luminosity measurement combining XMM-Newton and ROSAT, this could most likely
be caused by the bias in the velocity dispersion due to interlopers and low
member statistic in the previous sample of member galaxies, which was solely
based on 20 galaxy redshifts drawn from the literature. Aims: We intend to
increase the galaxy member statistic to perform a precision measurement of the
velocity dispersion and dynamical mass of S1101. We aim for a detailed
substructure and dynamical state characterization of this cluster, and a
comparison of mass estimates derived from (i) the velocity dispersion (M_vir),
(ii) the caustic mass computation (M_caustic), and (iii) mass proxies from
X-ray observations and the Sunyaev-Zeldovich (SZ) effect. Methods: We carried
out new optical spectroscopic observations of the galaxies in this cluster
field with VIMOS, obtaining a sample of ~60 member galaxies for S1101. We
revised the cluster redshift and velocity dispersion measurements based on this
sample and also applied the Dressler-Shectman substructure test. Results: The
completeness of cluster members within r200 was significantly improved for this
cluster. Tests for dynamical substructure did not show evidence for major
disturbances or merging activities in S1101. We find good agreement between the
dynamical cluster mass measurements and X-ray mass estimates which confirms the
relaxed state of the cluster displayed in the 2D substructure test. The SZ mass
proxy is slightly higher than the other estimates. The updated measurement of
the velocity dispersion erased the deviation of S1101 in the L-sigma relation.Comment: 17 pages, 7 figures, 5 table
Reaching out and reaching up - developing a low cost drug treatment system in Cambodia
Cambodia, confronted by the spread of drug misuse among young people, requested support from international agencies to develop a drug treatment programme in 2000. The initial plan developed by the United Nations Office on Drugs and Crime was to set up a number of conventional drug treatment centres in urban areas. During the planning phase, however, the project was redesigned as a community based outreach programme. Ten Community Counselling Teams have been formed and trained in pilot areas, and within the first year of operation 462 drug and alcohol users contacted. Comprising former drug users, family members affected by drug use and health care staff, they have drug scene credibility, local knowledge and connectivity, and a rudimentary level of medical competence. Crucially, they enjoy the support of village elders, who are involved in the planning and reporting stages. While the Community Counselling Teams with their basic training in addiction counselling are in no position as yet to either provide or refer clients to treatment, they can provide brief interventions, organise self help groups, and most importantly provide an alternative to law enforcement. By taking a development centred approach, with emphasis on community, empowerment and inclusion, it provides a constructive and inclusive alternative to medical approaches and the compulsory drug treatment centres. The paper is based on an evaluation involving interviews with a range of stakeholders and a review of project documents
Designing Lectures as a Team and Teaching in Pairs
[EN] A technique that is frequently used in modern software development is the so-called pair programming. The proven idea behind this technique is that innovative work in a highly complex environment can benefit from the synergy between two persons working together with well-defined roles. The transfer of this technique as a metaphor for teaching has repeatedly been reported as a successful teaching strategy called pair teaching. In this paper, we describe our experiences with designing and teaching a complete lecture on software development as a pair. Our contribution is the definition of patterns for role-assignments to both persons. These include patterns for the design of the lecture as well as patterns for the teaching in class itself. Our experience shows that there also exists a couple of anti-patterns namely role distributions that should be avoided. First evaluation results are promising in the sense that the reception of structure and content as well as students' satisfaction increased significantly with the introduction of pair design and pair teaching. http://ocs.editorial.upv.es/index.php/HEAD/HEAD18Zehetmeier, D.; BÜttcher, A.; Brßggemann-Klein, A. (2018). Designing Lectures as a Team and Teaching in Pairs. Editorial Universitat Politècnica de València. 873-880. https://doi.org/10.4995/HEAD18.2018.8103OCS87388
Delta-Sigma signal processing in control engineering
In modernen Anwendungen werden Ăźberabtastende Analog-zu-Digital Umsetzer eingesetzt. Eine besondere Klasse sind die Delta-Sigma-Analog-zu-Digital Umsetzer (ADU). Sie werden bei sehr hohen Abtastfrequenzen betrieben, in der Regel bei dem 64- bis 1024-fachen der Signalfrequenz, dafĂźr besitzen sie eine sehr geringe Quantisierung, bis zu einem Bit. Mit entsprechenden digitalen Filtern lassen sich mit dem Verfahren Wortbreiten von 12 bis 16 Bit erreichen. Allerdings begrenzt dabei das Filter die erzielbare Kleinsignalbandbreite. Mit der weiterentwickelten und vorgestellten ÎÎŁ Signalverarbeitung (ÎÎŁSV) kann auf die Filterung verzichtet werden.
In dieser Arbeit werden unterschiedliche Verfahren zur ÎÎŁSV evaluiert. Das Ergebnis stellen sowohl Klassen fĂźr lineare, als auch eine Klasse fĂźr nichtlineare Operationen dar, die eine gute Abbildungsqualität besitzen und alle Funktionen aus der jeweiligen Klasse abbilden kĂśnnen.
Basierend auf diesen Operationen wird die Strom- und Spannungsregelung einer dreiphasigen Last vorgestellt. Zur Umsetzung der hochfrequenten BitstrĂśme in leistungshalbleitertaugliche Schaltfrequenzen wird ein hysteresebasierter Modulator, der echte Raumzeigermodulation mit beiden Nullvektoren beherrscht, eingesetzt. FĂźr diesen wird ein Schaltfrequenzregler vorgestellt und unterschiedliche Stromregler erprobt.
AbschlieĂend wird eine drehgeberlose Geschwindigkeitsregelung in ÎÎŁSV vorgestellt.In modern applications oversampling analog-to-digital converters (ADC) are used. A special class are the Delta-Sigma-ADCs. They operate at very high sampling frequencies, usually at 64 up to 1024 times the signal frequency, but have a very low quantization, down to one bit. With corresponding digital filters, word sizes from 12 to 16 Bit can be achieved. However, the filters limit the achievable small signal bandwidth. In order to ommit these, the ÎÎŁ signal processing (ÎÎŁSP) has been developed.
In this thesis different methods for ÎÎŁSP are evaluated. As a result, a class for linear as well as a class for nonlinear operations is presented, which have a good projection quality and can map all functions of the respective class.
Based on these operations, the current and voltage regulation of a threephase load is presented. To convert the high-frequency bitstreams into switching frequencies suitable for power semiconductors, a hysteresis-based modulator is presented which outputs true space vector modulation with both zero vectors. For this modulator a switching frequency controller is presented and diferent current controllers are evaluated.
Concluding, an encoderless speed control is presented in ÎÎŁSP
Drug problem or medicrime? Distribution and use of falsified Tramadol medication in Egypt and West Africa
Tramadol is a synthetic opioid that is widely used as an analgesic for alleviating pain of moderate to medium intensity. With potency estimated to be about one-tenth that of morphine, tramadol is considered as relatively safe with regard to poisonings or dependency. Yet there are increasing reports of widespread non-medical consumption of tramadol in North and West Africa. The Egyptian government has requested the UN Commission of Narcotic Drugs to put tramadol under international control. This will have profound implications for the treatment of acute and chronic pain across developing countries where tramadol is often the only available analgesic, because controlled substances are impossible to obtain for health care practitioners. The tramadol sold outside of medical establishments is often adulterated and substandard, part of the massive trade in falsified medicines that is possibly far more devastating than the hedonic use of psychoactive substances. Yet the international machinery in place to control medical products is feeble and the penalties for medicrime are modest next to drug trafficking offences. The article suggests that international controls need to re-assess their priorities to focus on human and patient well-being. A further shift is needed away from repressive measures against consumers, to tighter regulation in the production and distribution of medications and pharmaceutical substances. This must involve a wide range of stakeholders, including health care practitioners, the pharmaceutical industry, pharmacists, patients associations, and the public at large
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