Informal “Seed” Systems and the Management of Gene Flow in Traditional Agroecosystems: The Case of Cassava in Cauca, Colombia

Our ability to manage gene flow within traditional agroecosystems and their repercussions requires understanding the biology of crops, including farming practices' role in crop ecology. That these practices' effects on crop population genetics have not been quantified bespeaks lack of an appropriate analytical framework. We use a model that construes seed-management practices as part of a crop's demography to describe the dynamics of cassava (Manihot esculenta Crantz) in Cauca, Colombia. We quantify several management practices for cassava—the first estimates of their kind for a vegetatively-propagated crop—describe their demographic repercussions, and compare them to those of maize, a sexually-reproduced grain crop. We discuss the implications for gene flow, the conservation of cassava diversity, and the biosafety of vegetatively-propagated crops in centers of diversity. Cassava populations are surprisingly open and dynamic: farmers exchange germplasm across localities, particularly improved varieties, and distribute it among neighbors at extremely high rates vis-à-vis maize. This implies that a large portion of cassava populations consists of non-local germplasm, often grown in mixed stands with local varieties. Gene flow from this germplasm into local seed banks and gene pools via pollen has been documented, but its extent remains uncertain. In sum, cassava's biology and vegetative propagation might facilitate pre-release confinement of genetically-modified varieties, as expected, but simultaneously contribute to their diffusion across traditional agroecosystems if released. Genetically-modified cassava is unlikely to displace landraces or compromise their diversity; but rapid diffusion of improved germplasm and subsequent incorporation into cassava landraces, seed banks or wild populations could obstruct the tracking and eradication of deleterious transgenes. Attempts to regulate traditional farming practices to reduce the risks could compromise cassava populations' adaptive potential and ultimately prove ineffectual

Self-medication of migraine and tension-type headache: summary of the evidence-based recommendations of the Deutsche Migräne und Kopfschmerzgesellschaft (DMKG), the Deutsche Gesellschaft für Neurologie (DGN), the Österreichische Kopfschmerzgesellschaft (ÖKSG) and the Schweizerische Kopfwehgesellschaft (SKG)

The current evidence-based guideline on self-medication in migraine and tension-type headache of the German, Austrian and Swiss headache societies and the German Society of Neurology is addressed to physicians engaged in primary care as well as pharmacists and patients. The guideline is especially concerned with the description of the methodology used, the selection process of the literature used and which evidence the recommendations are based upon. The following recommendations about self-medication in migraine attacks can be made: The efficacy of the fixed-dose combination of acetaminophen, acetylsalicylic acid and caffeine and the monotherapies with ibuprofen or naratriptan or acetaminophen or phenazone are scientifically proven and recommended as first-line therapy. None of the substances used in self-medication in migraine prophylaxis can be seen as effective. Concerning the self-medication in tension-type headache, the following therapies can be recommended as first-line therapy: the fixed-dose combination of acetaminophen, acetylsalicylic acid and caffeine as well as the fixed combination of acetaminophen and caffeine as well as the monotherapies with ibuprofen or acetylsalicylic acid or diclofenac. The four scientific societies hope that this guideline will help to improve the treatment of headaches which largely is initiated by the patients themselves without any consultation with their physicians

Cross-linking of initiation factor IF-2 to Escherichia coli 30 S ribosomal proteins with dimethylsuberimidate.

International audienceThe 30 S ribosomal proteins near the binding site for initiation factor IF-2 in Escherichia coli were identified by allowing complexes of 30 S subunits, [32P]phosphoryl initiation factor IF-2 and nonradioactive initiation factors IF-1 and IF-3, to react with the protein cross-linking reagent dimethylsuberimidate. Noncross-linked initiation factors were removed by centrifugation of the complexes in buffer containing a high salt concentration; the protein was extracted from the pelleted particles; and cross-linked species containing initiation factor IF-2 and ribosomal proteins were partially purified by column chromatography on Sephadex G-75. The mixture of cross-linked products was analyzed by radioimmunodiffusion with antisera prepared against 20 individual 30 S ribosomal proteins S1, S2, S11, S12, S13, S14, and S19 was interpreted to mean that initiation factor IF-2 was present in covalent cross-linked complexes containing those proteins. The results imply that these 30 S ribosomal proteins are near the binding site for initiation factor IF-2.The 30 S ribosomal proteins near the binding site for initiation factor IF-2 in Escherichia coli were identified by allowing complexes of 30 S subunits, [32P]phosphoryl initiation factor IF-2 and nonradioactive initiation factors IF-1 and IF-3, to react with the protein cross-linking reagent dimethylsuberimidate. Noncross-linked initiation factors were removed by centrifugation of the complexes in buffer containing a high salt concentration; the protein was extracted from the pelleted particles; and cross-linked species containing initiation factor IF-2 and ribosomal proteins were partially purified by column chromatography on Sephadex G-75. The mixture of cross-linked products was analyzed by radioimmunodiffusion with antisera prepared against 20 individual 30 S ribosomal proteins S1, S2, S11, S12, S13, S14, and S19 was interpreted to mean that initiation factor IF-2 was present in covalent cross-linked complexes containing those proteins. The results imply that these 30 S ribosomal proteins are near the binding site for initiation factor IF-2

Reducing Medication Regimen Complexity: A Controlled Trial

OBJECTIVE: To determine if a visual intervention (medication grid) delivered to physicians can reduce medication regimen complexity. DESIGN: Nonrandomized, controlled trial. SETTING: Veterans Affairs medical center. PATIENTS/PARTICIPANTS: Eight hundred thirty-six patients taking at least 5 medications at the time of admission and the 48 teams of physicians and students on the general medicine inpatient service. INTERVENTION: For intervention patients, a medication grid was created that displayed all of the patients' medicines and the times of administration for 1 week. This grid was delivered to the admitting resident soon after admission. MEASUREMENTS AND MAIN RESULTS: For the patients of each team of physicians, we calculated the change in the average number of medications and doses from admission to discharge. The number of medications in the intervention group decreased by 0.92 per patient, and increased by 1.65 in the control group (P < .001). The mean number of doses per day in the intervention group decreased by 2.47 per patient and increased by 3.83 in the control group (P < .001). CONCLUSIONS: This simple intervention had a significant impact on medication regimen complexity in this population. Apparently, physicians were able to address polypharmacy when the issue was brought to their attention