Addressing legal and policy barriers to male circumcision for adolescent boys in South Africa

With millions of adolescents becoming infected with HIV globally, it is essential that barriers to much-needed interventions are reduced for at-risk adolescents. In this article we review the legal and policy framework in South Africa for adolescent access to male circumcision. We are of the view that the framework does confer protection for adolescent boys while enabling access to male circumcision; however, we identify ambiguities and tensions that exist between the Children’s Act, regulations and national guidelines. We recommend reform to further enable access by this vulnerable group to this prevention modality

One step forward, two steps back – requiring ministerial approval for all ‘non-therapeutic\' health research involving minors

The new National Health Act has clarified that children may take part in ‘non-therapeutic\' research (NTR) and the age at which they may provide independent consent to such research, viz. at legal majority. However, the Act will require consent from the Minister of Health for all research classed as NTR and involving minors regardless of the level of risk. This requirement is overly broad. It will require that low-risk research without direct benefits, which might be adequately reviewed by an accredited research ethics committee (REC), must also be reviewed by the Minister. As it currently stands this requirement serves no plausible ethical purpose, will cause delays and discourage essential research on the needs of children, and may inspire researchers and RECs alike to ‘foil the system\'. We argue that in the long term there should be comprehensive law reform for child research. However, in the short term, amendments should be made to the Act to narrow the scope of this provision. The amendment should require ministerial consent for research that is currently not approvable by an REC in terms of national ethical guidelines, namely, research that does not hold out direct benefit but presents more than a minor increase over minimal risk. If our law reform recommendations are rejected, we favour the delegation of this task to RECs because, if they receive appropriate training, they should be competent to conduct it. We accept the disadvantages, namely that the same body will review protocols twice from slightly different perspectives and that certain categories of research will remain unapprovable.South African Medical Journal Vol. 97 (2) 2007: pp.200-202

Relationship of Weed Control and Soil pH to No-Tillage Corn Yields

Atrazine and simazine are used for selective control of a broad spectrum of weeds in corn. Over 80% of the U.S. corn production is treated with one or the other of these two s-triazine herbicides. In Kentucky they are used annually on over 800,000 acres of corn, including over 200,000 acres of no-tillage corn. When added to the soil these compounds are ultimately degraded to non-phytotoxic compounds. The rate of degradation is dependent upon the physical, chemical, and biological properties of the soil. Although atrazine and simazine are chemically similar, simazine is considered to degrade slightly slower than atrazine after application to the soil and as a result will remain in the soil for a longer period of time

Glass-Like Heat Conduction in High-Mobility Crystalline Semiconductors

The thermal conductivity of polycrystalline semiconductors with type-I clathrate hydrate crystal structure is reported. Ge clathrates (doped with Sr and/or Eu) exhibit lattice thermal conductivities typical of amorphous materials. Remarkably, this behavior occurs in spite of the well-defined crystalline structure and relatively high electron mobility ($\sim 100 cm^2/Vs$). The dynamics of dopant ions and their interaction with the polyhedral cages of the structure are a likely source of the strong phonon scattering.Comment: 4 pages, 3 postscript figures, to be published, Phys. Rev. Let

Heat transport in model jammed solids

We calculate numerically the normal modes of vibrations in 3D jammed packings of soft spheres as a function of the packing fraction and obtain the energy diffusivity, a spectral measure of transport that controls sound propagation and thermal conductivity. The crossover frequency between weak and strong phonon scattering is controlled by the coordination and shifts to zero as the system is decompressed towards the critical packing fraction at which rigidity is lost. Below the crossover, the diffusivity displays a power-law divergence with inverse frequency, which suggests that the vibrational modes are primarily transverse waves, weakly scattered by disorder. Above it, a large number of modes appear whose diffusivity plateaus at a nearly constant value independent of the inter-particle potential, before dropping to zero above the Anderson localization frequency. The thermal conductivity of a marginally jammed solid just above the rigidity threshold is calculated and related to the one measured experimentally at room temperature for most glasses.Comment: 15 pages, 7 figure

Using the Indirect Cohort Design to Estimate the Effectiveness of the Seven Valent Pneumococcal Conjugate Vaccine in England and Wales

BACKGROUND: The 7-valent pneumococcal conjugate vaccine (PCV-7) was introduced in the United Kingdom in 2006 with a 2, 3 and 13 month schedule, and has led to large decreases in invasive pneumococcal disease (IPD) caused by the vaccine serotypes in both vaccinated and unvaccinated cohorts. We estimated the effectiveness of PCV-7 against IPD. METHODS AND FINDINGS: We used enhanced surveillance data, collated at the Health Protection Agency, on vaccine type (n = 153) and non vaccine type (n = 919) IPD cases eligible for PCV-7. The indirect cohort method, a case-control type design which uses non vaccine type cases as controls, was used to estimate effectiveness of various numbers of doses as well as for each vaccine serotype. Possible bias with this design, caused by differential serotype replacement in vaccinated and unvaccinated individuals, was estimated after deriving formulae to quantify the bias. The results showed good effectiveness, increasing from 56% (95% confidence interval (CI): -7-82) for a single dose given under one year of age to 93% (95% CI: 70-98) for two doses under one year of age plus a booster dose in the second year of life. Serotype specific estimates indicated higher effectiveness against serotypes 4, 14 and 18C and lower effectiveness against 6B. Under the assumption of complete serotype replacement by non vaccine serotypes in carriage, we estimated that effectiveness estimates may be overestimated by about 2 to 5%. CONCLUSIONS: This study shows high effectiveness of PCV-7 under the reduced schedule used in the UK. This finding agrees with the large reductions seen in vaccine type IPD in recent years in England and Wales. The formulae derived to assess the bias of the indirect cohort method for PCV-7 can also be used when using the design for other vaccines that affect carriage such as the recently introduced 13 valent pneumococcal conjugate vaccine

Heat Conduction and Magnetic Phase Behavior in Electron-Doped Ca_{1-x} La_x MnO_3(0 <= x <= 0.2)

Measurements of thermal conductivity (kappa) vs temperature are reported for a series of Ca_{1-x} La_x MnO_3(0 <= x <= 0.2) specimens. For the undoped (x=0), G-type antiferromagnetic compound a large enhancement of kappa below the Neel temperature (T_N ~ 125 K) indicates a strong coupling of heat-carrying phonons to the spin system. This enhancement exhibits a nonmonotonic behavior with increasing x and correlates remarkably well with the small ferromagnetic component of the magnetization reported previously [Neumeier and Cohn, Phys. Rev. B 61 14319 (2000).] Magnetoelastic polaron formation appears to underly the behavior of kappa and the magnetization at x <= 0.02.Comment: submitted to PRB; 4 pp., 4 Fig.'s, RevTex

Addressing legal and policy barriers to male circumcision for adolescent boys in South Africa

With millions of adolescents becoming infected with HIV globally, it is essential that barriers to much-needed interventions are reduced for at-risk adolescents. In this article we review the legal and policy framework in South Africa for adolescent access to male circumcision. We are of the view that the framework does confer protection for adolescent boys while enabling access to male circumcision; however, we identify ambiguities and tensions that exist between the Children’s Act, regulations and national guidelines. We recommend reform to further enable access by this vulnerable group to this prevention modality

Dessaisissement et décentralisation portuaires : analyse comparative Canada-France

Il s'agit d'étudier, dans le domaine du transport des marchandises, les modifications institutionnelles et réglementaires et les évolutions qu'elles provoquent dans la stratégie des acteurs, tant privés que publics, ainsi que les modifications induites sur les territoires . Le travail sur la relation entre changement de statut et évolution portuaire exige la prise en compte des différents fonctionnements portuaires. Il est nécessaire de comprendre comment les ports décentralisés répondent aujourd'hui aux besoins des clients locaux et d'évaluer le rôle joué par la communauté d'intervenants locaux dans la planification, l'exploitation et le développement des ports. Plus précisément, les objectifs consistent à : évaluer les défis et les opportunités engendrés par ces nouvelles organisations ; comprendre l'organisation des besoins d'investissements lourds nécessaires au maintien et à l'expansion des équipements ; comprendre l'impact de ces changements de statut sur l'évolution des trafics (volume, produit, marché)ADMINISTRATION (GESTION);FLUX DE MARCHANDISE;TRANSPORT MARITIME;PORT;ETUDE D'IMPACT;DECENTRALISATION;CANADA;FRANCE