Consumer awareness and attitudes toward GM foods in Kenya

A survey of 604 consumers was conducted in Nairobi, Kenya, in November and December 2003, at three points of sale (supermarkets, kiosks, and posho mills) to determine consumer awareness and attitudes towards genetically modified (GM) foods. Above a third (38%) of the respondents were aware of GM crops, mostly from newspapers, television and radio. Others had learned about GM crops at school. Newspapers and television were more important to higher-income and more educated consumers. Consumers acknowledged the technology’s potential positive impacts, with more than 80% agreeing that it increases productivity. Sixty-eight percent said they would buy GM maize meal at the same price as their favorite brands, although many had concerns; half of the respondents feared that GM technology could lead to a loss of biodiversity and affect non-target insects; while more than one- third (37%) had concerns about the effects of GM food on human health. We conclude that GM technology has a role to play in food security in Kenya. However, consumers need more information about the technology, which can be provided through established sources of information. Finally, consumer attitudes should be studied regularly, and the survey population broadened to include rural consumers

Developing Bt maize for resource-poor farmers – Recent advances in the IRMA project

This paper presents an overview of the advances in the IRMA project, which develops insect resistant maize varieties for resource-poor farmers, using both conventional breeding and genetic engineering. The project started in 1999 and is active in product development, impact assessment, andcommunication, all within the Kenya regulatory framework. So far, four application for introduction of tissue or commencement of field research were made to and approved by the National Biosafety Committee (NBC), and Bt maize leaves or seeds genes imported for testing against different stem borer species in bioassays on cut leaves in a biosafety laboratory, in potted plants in a Biosafety Greenhouse, and as whole plants in confined field trials in the Open Quarantine Station (OQS) at KARI Kiboko. All these biosafety facilities were specially built by the project for these evaluations. So far, good control has been realized against four of the five major stem borer species: Chilo partellus, Chilo orichalcociliellus, Eldana saccharina and Sesamia calamistis. Economic  impact assessment demonstrated that stem borers are major constraints and cause substantial losses. Resistant maizevarieties are likely to be adopted and to provide major returns to the investment if resistance against the economically most important species, Busseola fusca, can be found. Otherwise, returns would still be positive but small. Environmental impact research indicate that build-up of resistance against the Bt genes has not developed after that sufficient natural refugia exist in most areas, but suitable strategies acceptable to farmers need to be developed for some. Surveys, stakeholders meetings and other communications indicate that farmers, consumers and other stakeholders are cautiously optimistic about technology. Frequent interaction with the stakeholders and regulatory agencies assures a participative decision-making process and compliance with the strictest scientific and regulatorystandards

The two electron artificial molecule

Exact results for the classical and quantum system of two vertically coupled two-dimensional single electron quantum dots are obtained as a function of the interatomic distance (d) and with perpendicular magnetic field. The classical system exhibits a second order structural transition as a function of d which is smeared out and shifted to lower d values in the quantum case. The spin-singlet - spin-triplet oscillations are shifted to larger magnetic fields with increasing d and are quenched for a sufficiently large interatomic distance.Comment: 4 pages, 4 ps figure

A theory of normed simulations

In existing simulation proof techniques, a single step in a lower-level specification may be simulated by an extended execution fragment in a higher-level one. As a result, it is cumbersome to mechanize these techniques using general purpose theorem provers. Moreover, it is undecidable whether a given relation is a simulation, even if tautology checking is decidable for the underlying specification logic. This paper introduces various types of normed simulations. In a normed simulation, each step in a lower-level specification can be simulated by at most one step in the higher-level one, for any related pair of states. In earlier work we demonstrated that normed simulations are quite useful as a vehicle for the formalization of refinement proofs via theorem provers. Here we show that normed simulations also have pleasant theoretical properties: (1) under some reasonable assumptions, it is decidable whether a given relation is a normed forward simulation, provided tautology checking is decidable for the underlying logic; (2) at the semantic level, normed forward and backward simulations together form a complete proof method for establishing behavior inclusion, provided that the higher-level specification has finite invisible nondeterminism.Comment: 31 pages, 10figure

Decay-assisted collinear resonance ionization spectroscopy: Application to neutron-deficient francium

This paper reports on the hyperfine-structure and radioactive-decay studies of the neutron-deficient francium isotopes $^{202-206}$Fr performed with the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at the ISOLDE facility, CERN. The high resolution innate to collinear laser spectroscopy is combined with the high efficiency of ion detection to provide a highly-sensitive technique to probe the hyperfine structure of exotic isotopes. The technique of decay-assisted laser spectroscopy is presented, whereby the isomeric ion beam is deflected to a decay spectroscopy station for alpha-decay tagging of the hyperfine components. Here, we present the first hyperfine-structure measurements of the neutron-deficient francium isotopes $^{202-206}$Fr, in addition to the identification of the low-lying states of $^{202,204}$Fr performed at the CRIS experiment.Comment: Accepted for publication with Physical Review

Laser spectroscopy of francium isotopes at the borders of the region of reflection asymmetry

The magnetic dipole moments and changes in mean-square charge radii of the neutron-rich $^{218m,219,229,231}\text{Fr}$ isotopes were measured with the newly-installed Collinear Resonance Ionization Spectroscopy (CRIS) beam line at ISOLDE, CERN, probing the $7s~^{2}S_{1/2}$ to $8p~^{2}P_{3/2}$ atomic transition. The $\delta\langle r^{2}\rangle^{A,221}$ values for $^{218m,219}\text{Fr}$ and $^{229,231}\text{Fr}$ follow the observed increasing slope of the charge radii beyond $N~=~126$. The charge radii odd-even staggering in this neutron-rich region is discussed, showing that $^{220}\text{Fr}$ has a weakly inverted odd-even staggering while $^{228}\text{Fr}$ has normal staggering. This suggests that both isotopes reside at the borders of a region of inverted staggering, which has been associated with reflection-asymmetric shapes. The $g(^{219}\text{Fr}) = +0.69(1)$ value supports a $\pi 1h_{9/2}$ shell model configuration for the ground state. The $g(^{229,231}\text{Fr})$ values support the tentative $I^{\pi}(^{229,231}\text{Fr}) = (1/2^{+})$ spin, and point to a $\pi s_{1/2}^{-1}$ intruder ground state configuration.Comment: Accepted for publication with Physical Review

Mutated CTSF in adult-onset neuronal ceroid lipofuscinosis and FTD

OBJECTIVE: To investigate the molecular basis of a Belgian family with autosomal recessive adult-onset neuronal ceroid lipofuscinosis (ANCL or Kufs disease [KD]) with pronounced frontal lobe involvement and to expand the findings to a cohort of unrelated Belgian patients with frontotemporal dementia (FTD). METHODS: Genetic screening in the ANCL family and FTD cohort (n = 461) was performed using exome sequencing and targeted massive parallel resequencing. RESULTS: We identified a homozygous mutation (p.Ile404Thr) in the Cathepsin F (CTSF) gene cosegregating in the ANCL family. No other mutations were found that could explain the disease in this family. All 4 affected sibs developed motor symptoms and early-onset dementia with prominent frontal features. Two of them evolved to akinetic mutism. Disease presentation showed marked phenotypic variation with the onset ranging from 26 to 50 years. Myoclonic epilepsy in one of the sibs was suggestive for KD type A, while epilepsy was not present in the other sibs who presented with clinical features of KD type B. In a Belgian cohort of unrelated patients with FTD, the same heterozygous p.Arg245His mutation was identified in 2 patients who shared a common haplotype. CONCLUSIONS: A homozygous CTSF mutation was identified in a recessive ANCL pedigree. In contrast to the previous associations of CTSF with KD type B, our findings suggest that CTSF genetic testing should also be considered in patients with KD type A as well as in early-onset dementia with prominent frontal lobe and motor symptoms

Objective assessment of intraoperative skills for robot-assisted radical prostatectomy (RARP): results from the ERUS Scientific and Educational Working Groups Metrics Initiative

Objective: To develop and seek consensus from procedure experts on the metrics that best characterise a reference robot-assisted radical prostatectomy (RARP) and determine if the metrics distinguished between the objectively assessed RARP performance of experienced and novice urologists, as identifying objective performance metrics for surgical training in robotic surgery is imperative for patient safety. Materials and methods: In Study 1, the metrics, i.e. 12 phases of the procedure, 81 steps, 245 errors and 110 critical errors for a reference RARP were developed and then presented to an international Delphi panel of 19 experienced urologists. In Study 2, 12 very experienced surgeons (VES) who had performed >500 RARPs and 12 novice urology surgeons performed a RARP, which was video recorded and assessed by two experienced urologists blinded as to subject and group. Percentage agreement between experienced urologists for the Delphi meeting and Mann–Whitney U- and Kruskal–Wallis tests were used for construct validation of the newly identified RARP metrics. Results: At the Delphi panel, consensus was reached on the appropriateness of the metrics for a reference RARP. In Study 2, the results showed that the VES performed ~4% more procedure steps and made 72% fewer procedure errors than the novices (P = 0.027). Phases VIIa and VIIb (i.e. neurovascular bundle dissection) best discriminated between the VES and novices. Limitations: VES whose performance was in the bottom half of their group demonstrated considerable error variability and made five-times as many errors as the other half of the group (P = 0.006). Conclusions: The international Delphi panel reached high-level consensus on the RARP metrics that reliably distinguished between the objectively scored procedure performance of VES and novices. Reliable and valid performance metrics of RARP are imperative for effective and quality assured surgical training