Farmers, seeds and varieties : supporting informal seed supply in Ethiopia

Ethiopia is characterized by an enormous diversity in agro-ecosystems, crops and varieties, with the informal seed systems dominant in seed supply for almost all crops. The book addresses strategies and approaches through which professionals can support informal seed supply, and links these with the conservation and use of the huge genetic resource base of crops and local varieties. The book looks at informal seed supply from a number of different angles, introduces key concepts and strategies, and presents case studies from Ethiopia and other countries. It deals with the technical aspects of, quality and availability of, and access to seed, and of supporting informal supply. It also deals with the role of farmers in the conservation and management of local crops and varieties, and the participation of farmers and communities in plant breeding and research. It takes a particular interest in the role of farmer organizations in seed supply, and how this role can be strengthened by developing community and small-scale seed enterprises. The aim of all the strategies, case studies and reflections on experiences presented in this book is to improve the availability of and access to quality seeds and varieties, thereby improving the livelihoods of small-scale farmers in Ethiopia and beyond

Risk and Marketing Behavior: Pricing Fed Cattle on a Grid

A seven year comparative study of grid pricing versus average pricing of slaughter cattle was conducted to evaluate carcass quality market signals. The primary objective of the study is to determine if market signals sent through the grid pricing system are encouraging producers to market on a grid and discouraging them to market by the pen. Two secondary objectives investigate: 1) if price risk associated with carcass quality uncertainty affects marketing decisions, and 2) if a change in price risk (volatility) affects producer marketing decisions. An EARCH-ln-Mean modeling procedure was adopted. Empirical results suggest that the grid premium and discount structure is slowly adjusting carcass quality market signals to encourage marketing on a grid and discourage marketing by the pen. The inclusion of the conditional variance in the empirical model indicates that risk associated with carcass quality uncertainty is a potential barrier to adoption of the grid pricing system by producers

Culture-adapted Plasmodium falciparum isolates from UK travellers: in vitro drug sensitivity, clonality and drug resistance markers.

BACKGROUND: The screening of lead compounds against in vitro parasite cultures is an essential step in the development of novel anti-malarial drugs, but currently relies on laboratory parasite lines established in vitro during the last century. This study sought to establish in continuous culture a series of recent Plasmodium falciparum isolates to represent the current parasite populations in Africa, all of which are now exposed to artemisinin combination therapy. METHODS: Pre-treatment P. falciparum isolates were obtained in EDTA, and placed into continuous culture after sampling of DNA. One post-treatment blood sample was also collected for each donor to monitor parasite clonality during clearance in vivo. IC₅₀ estimates were obtained for 11 anti-malarial compounds for each established parasite line, clonal multiplicity measured in vivo and in vitro, and polymorphic sites implicated in parasite sensitivity to drugs were investigated at the pfmdr1, pfcrt, pfdhfr, pfdhps and pfap2mu loci before and after treatment, and in the cultured lines. RESULTS: Plasmodium falciparum isolates from seven malaria patients with recent travel to three West African and two East African countries were successfully established in long-term culture. One of these, HL1211, was from a patient with recrudescent parasitaemia 14 days after a full course of artemether-lumefantrine. All established culture lines were shown to be polyclonal, reflecting the in vivo isolates from which they were derived, and at least two lines reliably produce gametocytes in vitro. Two lines displayed high chloroquine IC₅₀ estimates, and carried the CVIET haplotype at codons 72-76, whereas the remaining five lines carried the CVMNK haplotype and were sensitive in vitro. All were sensitive to the endoperoxides dihydroartemisinin and OZ277, but IC₅₀ estimates for lumefantrine varied, with the least sensitive parasites carrying pfmdr1 alleles encoding Asn at codon 86. CONCLUSIONS: This study describes the establishment in continuous culture, in vitro drug sensitivity testing and molecular characterization of a series of multiclonal P. falciparum isolates taken directly from UK malaria patients following recent travel to various malaria-endemic countries in Africa. These "HL" isolates are available as an open resource for studies of drug response, antigenic diversity and other aspects of parasite biology

Epidemiological Characteristics and Survival Studies of Rhabdomyosarcoma in East Egypt: A Five-Year Multicenter Study

Background. Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children, it represents 5–8% of childhood malignancies. Aim of the Work. To evaluate the epidemiological characteristics and treatment outcome in two pediatric oncology centers. Patients and Method. A retrospective analysis was performed on 41 medical records of children with RMS during 6 years period. Results. The median age of patients was 6 years with 80.4% below 10 years. Head and neck was the most common primary site. Embryonal RMS was the most frequent histopathologic subtype. Stage IV was the most frequent stage. According to IRS postsurgical grouping classification, group 4 was the most frequent group. There was a significant relationship between histopathologic subtypes of tumor and metastasis, primary site of tumor and histopathologic subtype, age, metastasis, IRS presurgical stage and IRS postsurgical group and outcome. The overall survival rate was 56.9% ± 8.4 and the failure free survival rate was 68.3% ± 7.6. Conclusion. The epidemiological characteristics of our patients are quite near to the worldwide data, apart from the higher prevalence of stage IV and group 4 with most of the primary tumor site in the extremities. CWS2002 protocol of therapy had led to improvement in the curability of the disease

Plasmodium falciparum isolate with histidine-rich protein 2 gene deletion from Nyala City, Western Sudan.

In remote areas of malaria-endemic countries, rapid diagnostic tests (RDTs) have dramatically improved parasitological confirmation of suspected malaria cases, especially when skilled microscopists are not available. This study was designed to determine the frequency of Plasmodium falciparum isolates with histidine-rich protein 2 (pfhrp2) gene deletion as one of the possible factors contributing to the failure of PfHRP2-based RDTs in detecting malaria. A total of 300 blood samples were collected from several health centres in Nyala City, Western Sudan. The performance of PfHRP2-based RDTs in relation to microscopy was examined and the PCR-confirmed samples were investigated for the presence of pfhrp2 gene. A total of 113 out of 300 patients were P. falciparum positive by microscopy. Among them, 93.81% (106 out of 113) were positives by the PfHRP2 RDTs. Seven isolates were identified as false negative on the basis of the RDTs results. Only one isolate (0.9%; 1/113) potentially has pfhrp2 gene deletion. The sensitivity and specificity of PfHRP2-based RDTs were 93.81% and 100%, respectively. The results provide insights into the pfhrp2 gene deletion amongst P. falciparum population from Sudan. However, further studies with a large and systematic collection from different geographical settings across the country are needed

Radial artery ultrasound predicts the success of transradial coronary angiography

Background: The transradial approach has become the preferred vascular access during conventional coronary angiography (CCA). Hereby, we evaluated the impact of pre-procedural radial artery diameter (RAD), the cross-sectional area (CSA), and the perimeter on vascular complications (VACs). Methods: We conducted a single-center prospective analysis of 513 patients who underwent CCA. Radial artery ultrasonography was performed before and after CCA to measure the RAD, CSA, and perimeter. Results: The average RAD, CSA, and perimeter were 2.60 ± 0.48 mm, 6.2 ± 3.0 mm2, and 8.9 ± 1.7 mm, respectively. Vascular complications were reported in 56 (11%) patients. The RAD, CSA, and perimeter were significantly smaller in patients in whom procedure-related VACs were observed than in those with no complications: 2.3 ± 0.5 vs. 2.70 ± 0.54 mm (p = 0.0001), 4.9 ± 2.1 vs. 6.4 ± 3 mm2 (p = 0.001), and 7.6 ± 2.1 vs. 9.2 ± 1.6 mm (p = 0.0001), respectively. Univariate logistic regression showed that RAD, CSA and perimeter can independently predict VACs (OR 0.833, 95% CI 0.777–0.894, p < 0.0001; OR 0.647, 95% CI 0.541–0.773, p < 0.0001; OR 0.545, 95% CI 0.446–0.665, p < 0.0001, respectively). Conclusions: Ultrasonographic study of the radial artery before CCA can provide valuable information regarding vascular access.  

Low-Cost Methods for Molecular Characterization of Mutant Plants: Tissue Desiccation, DNA Extraction and Mutation Discovery: Protocols

Plant Breeding/Biotechnology; Biological Techniques; Nucleic Acid Chemistr

Low-Cost Methods for Molecular Characterization of Mutant Plants: Tissue Desiccation, DNA Extraction and Mutation Discovery: Protocols

Plant Breeding/Biotechnology; Biological Techniques; Nucleic Acid Chemistr

Effects of the Switching Frequency of Random Modulated Power Converter on the G3 Power Line Communication System

Power Line Communication (PLC) technologies utilize existing power cables for both power and data transmission which minimizes cost and complexity. However, recent studies show that alternative modulation schemes such as Random Pulse Width Modulation (RPWM), applied to power converter to minimize conducted emissions, have possible side effects on the PLC system. In this work, the effects of the switching frequency of randomly modulated power converter on the G3-PLC system is investigated. To this end, a range of switching frequencies from 10 kHz-100 kHz is applied to a randomly modulated DC-DC converter and its potential effect on the G3-PLC is studied. Experimental results confirmed that switching frequencies near the bandwidth of the G3-PLC caused significant disturbance and possible coexistence issue compared to the frequencies out of this range. Moreover, there is a tradeoff between Electromagnetic Interference (EMI) reduction and coexistence issue that is Random Frequency Modulation, which is very effective for EMI reduction, is found to be very disruptive for G3-PLC, compared to alternative random modulation techniques like Random Pulse Position Modulation