64 research outputs found
Application of mutation breeding to the improvement of the under-studied crop tef (Eragrostis tef (Zucc.) Trotter).
No full textInduced mutation has been playing a significant role in the improvement of diverse crop types. This led to the release of over 3200 crop varieties in over 70 countries. We implemented induced mutation on tef (Eragrostis tef (Zucc.) Trotter), one of the most important cereal crops in the Horn of Africa, especially in Ethiopia, where it is annually cultivated on over 3 million hectares of land, equivalent to 30% of the total area allocated to cereals. Although tef is extensively cultivated in Ethiopia due to its resilience to diverse environmental stresses, the productivity of the crop is very low. The Tef Improvement Project based at the University of Bern in Switzerland employs mutation breeding to tackle major constraints in tef in order to enhance crop productivity. About 12,000 EMS (ethyl methanesulfonate) mutagenized M2 families were generated from four improved tef varieties, namely ‘Tsedey’, ‘Dukem’, ‘Kora’ and ‘Dagim’. Screening for major traits of importance helped us to obtain several candidate lines, including semi-dwarf and lodging-tolerant, drought-tolerant and acid-soil-tolerant lines. Among these, the most promising ones were introgressed to locally adapted improved varieties followed by several years of testing at representative locations for traits of interest. As a result, a new variety called ‘Tesfa’ with a novel and desirable combination of traits was approved for release to the farming community. This shows that the project has been actively involved in all three phases of induced mutation: mutation induction, mutation detection and mutation breeding
Seed-Business Oriented Demonstration Trials: An Efficient Option to Promote Tef (Eragrostis tef ) Varieties
No full textአህፅሮት
ኢትዮጵያ ውስጥ ጤፍ (Eragrostis tef) ከ6.5 ሚሊዮን በሚበልጡ አነስተኛ አርሶ አደሮች ይመረታል፡፡ ሆኖም ግን የተሻሻሉ ቴክኖሎጂዎችና የምርጥ ዘር ተጠቃሚነት ውስን በመሆኑ የሰብሉ ምርታማነት ዝቅተኛ እንደሆነ ቀጥሏል፡፡ ስለሆነም አነስተኛ አርሶ አደሮች ጥራቱን ለጠበቀ የጤፍ አራቢ ዘር ያላቸውን ተደራሽነት ለመጨመር ዓላማ ያደረገ ጥናት በ254 መሪ አርሶ አደሮች ማሳ ላይ ተካሂዷል፡፡ በጥናቱም በቅርብ ጊዜ የተለቀቁ ሦስት አዳዲስ ዝርያዎች እና አንድ ቀደም ብሎ የተለቀቀ ዝርያ (ቦሰት) ተካተው ተገምግመዋል፡፡ ለእያንዳንዱ መሪ-አርሶ አደር የአራቱም ዝርያዎች ማለትም የኮራ፣ የተስፋ፣ የዳግም እና የቦሰት አራቢ ዘር ተሰጥቷል፡፡ የአራቱ ዝርያዎች የዘር ምርት ተቀራራቢ (ኮራ = 1.94፣ ተስፋ = 2.31፣ ዳግም = 2.24 እና ቦሰት = 2.36 ቶን በሄክታር) ነበር፡፡ ጥናቱ በተካሄደባቸው ወረዳዎች ያለውን የግብዓት ዋጋ እና የምርት ዋጋ እሳቤ ውስጥ ሲገባ የተገኘው አማካይ ያልተጣራ ገቢ 65,355.90 ብር በሄክታር ሲሆን አማካይ የማምረቻ ወጪው ደግሞ 26,355.52 ብር በሄክታር ነበር፡፡ ከማምረቻ ወጪዎች መካከል ለጉልበት የወጣው ወጪ ትልቁን ድርሻ ሲይዝ ከጠቅላላው ወጪ 58 በመቶ ድርሻ ነበረው፡፡ በአጠቃላይ የገቢ-ወጪ ምጣኔ 1.5 በመሆኑ የተሻሻለ የጤፍ ዝርያ ቴክኖሎጂ መጠቀም በጣም ትርፋማ እንደሆነ ጥናቱ ያመልክታል፡፡ ይህም በመሆኑ አዳዲስ የሚወጡ የጤፍ ዝርያዎችን ዘር አባዝቶ ለገብያ ማቅረብን ትኩረት ያደረገ የሰርቶ ማሳያ ስራ ቢሰራ ለአርሶ አደሮች ሳቢና አዋጭ ሆኖ ተገኝትዋል፡፡
ጠቋሚ ቃላት፡ መሪ አርሶ አደሮች፤ የጤፍ ዝርያዎች፤ የምርጥ ዘር ምርት፤ የጤፍ ጭድ፤ የምርት ዋጋ
Abstract
Tef (Eragrostis tef) is extensively cultivated by over 6.5 million smallholder farmers in Ethiopia. However, the productivity of the crop remains low mainly due to the limited use of improved technologies including seeds. In this study, three recently released and one old (as a check) tef varieties were evaluated on 254 lead farmers’ fields with the main aim of increasing farmers’ access to quality breed seeds.Each lead farmer was provided with breeder seeds of four improved tef varieties, namely Kora, Tesfa, Dagim, and Boset.The seed yield from the four tef varieties were comparable (Kora = 1.94, Tesfa = 2.31, Dagim =2.24 and Boset = 2.36 t ha-1). Given the input and output prices that prevail in the selected districts, the mean revenue was 65,355.90 Birr ha-1 while the mean production cost was 26,355.52 Birr ha-1. Among production costs, labor took for the lion’s share as it contributed to 58% of the total cost. In general, with a benefit-cost ratio of 1.5, our technology is highly profitable and attractive to farmers if newly released tef varieties are disseminated in the seed-business-oriented method.
 
Drug-screening and genomic analyses of HER2-positive breast cancer cell lines reveal predictors for treatment response
No full textSandra Jernström,1,2 Vesa Hongisto,3 Suvi-Katri Leivonen,1,2 Eldri Undlien Due,1 Dagim Shiferaw Tadele,1 Henrik Edgren,4,5 Olli Kallioniemi,4 Merja Perälä,6 Gunhild Mari Mælandsmo,2,7,8 Kristine Kleivi Sahlberg,1,9 1Department of Cancer Genetics, Institute for Cancer Research, Oslo University Hospital, 2KG Jebsen Centre for Breast Cancer Research, Institute for Clinical Medicine, University of Oslo, Oslo, Norway; 3Misvik Biology Oy, Turku, 4Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, 5Medisapiens, Helsinki, Finland, 6VTT Technical Research Centre of Finland, Turku, Finland; 7Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway; 8Institute of Pharmacy, Faculty of Health Sciences, University of Tromsø, Tromsø, 9Department of Research, Vestre Viken Hospital Trust, Drammen, Norway Background: Approximately 15%–20% of all diagnosed breast cancers are characterized by amplified and overexpressed HER2 (= ErbB2). These breast cancers are aggressive and have a poor prognosis. Although improvements in treatment have been achieved after the introduction of trastuzumab and lapatinib, many patients do not benefit from these drugs. Therefore, in-depth understanding of the mechanisms behind the treatment responses is essential to find alternative therapeutic strategies. Materials and methods: Thirteen HER2 positive breast cancer cell lines were screened with 22 commercially available compounds, mainly targeting proteins in the ErbB2-signaling pathway, and molecular mechanisms related to treatment sensitivity were sought. Cell viability was measured, and treatment responses between the cell lines were compared. To search for response predictors and genomic and transcriptomic profiling, PIK3CA mutations and PTEN status were explored and molecular features associated with drug sensitivity sought. Results: The cell lines were divided into three groups according to the growth-retarding effect induced by trastuzumab and lapatinib. Interestingly, two cell lines insensitive to trastuzumab (KPL4 and SUM190PT) showed sensitivity to an Akt1/2 kinase inhibitor. These cell lines had mutation in PIK3CA and loss of PTEN, suggesting an activated and druggable Akt-signaling pathway. Expression levels of five genes (CDC42, MAPK8, PLCG1, PTK6, and PAK6) were suggested as predictors for the Akt1/2 kinase-inhibitor response. Conclusion: Targeting the Akt-signaling pathway shows promise in cell lines that do not respond to trastuzumab. In addition, our results indicate that several molecular features determine the growth-retarding effects induced by the drugs, suggesting that parameters other than HER2 amplification/expression should be included as markers for therapy decisions. Keywords: ErbB2, drug screening, gene expression, pharmacogenomics, predictor
Factors associated with medication adherence among patients with schizophrenia in Mekelle, Northern Ethiopia.
No full textBackgroundNon-adherence to antipsychotic medication has a negative impact on the course of illness resulting in increased risk of relapse, rehospitalization and suicide, and increased costs to healthcare systems. The objective of this study was to investigate factors associated with medication adherence among patients with schizophrenia at Ayder Referral Hospital and Mekelle Hospital in Mekelle, Tigray region, Northern Ethiopia.MethodsThe study was a cross-sectional survey in which sociodemographic characteristics, drug attitudes, insight and side effects were measured and explored in terms of their relationship with medication adherence. A structured questionnaire as a data collection tool was used. Data were analyzed with the help of SPSS Version 20.0.ResultsA total of 393 patients participated, 26.5% were non-adherent to their antipsychotic medication. The factors significantly associated with better adherence were positive treatment attitudes (AOR = 1.40, 95% CI: 1.26, 1.55), fewer side effects (AOR = 0.97, 95% CI: 0.94, 0.99), awareness of illness (AOR = 1.44, 95% CI: 1.12, 1.85) and the ability to relabel symptoms (AOR = 1.57, 95% CI: 1.19, 2.07). However, khat chewers (AOR = 0.24, 95% CI: 0.09, 0.68), being illiterate (AOR = 0.13, 95% CI: 0.03, 0.47) and older age group (AOR = 0.03, 95% CI: 0.01, 0.16) were associated with less medication adherence.ConclusionsA high prevalence of medication non-adherence was found among patients with schizophrenia. Intervention strategies focused on educating the patients to better understand the illness, medications and their potential side effects might be useful in improving adherence to antipsychotic medication treatment
Association of sociodemographic factors with antipsychotic medication adherence among patients with schizophrenia.
No full text<p>Association of sociodemographic factors with antipsychotic medication adherence among patients with schizophrenia.</p
CD4 cell count trends after commencement of antiretroviral therapy among HIV-infected patients in Tigray, Northern Ethiopia: a retrospective cross-sectional study.
No full textThe rate and extent of CD4 cell recovery varies widely among HIV-infected patients with different baseline CD4 cell count strata. The objective of the study was to assess trends in CD4 cell counts in HIV-infected patients after initiation of antiretroviral therapy in Tigray, Northern Ethiopia.A retrospective cross-sectional study was conducted by reviewing medical records of HIV patients who received antiretroviral treatment at twenty health centers in Tigray region during 2008-2012. Multi-stage cluster sampling technique was employed to collect data, and the data were analyzed using SPSS version 20.0 software.The median change from baseline to the most recent CD4 cell count was +292 cells/μl. By 5 years, the overall median (inter-quartile range, IQR) CD4 cell count was 444(263-557) cells/μl while the median (IQR) CD4 cell count was 342(246-580) cells/μl among patients with baseline CD4 cell counts ≤200 cells/μl, 500(241-557) cells/μl among those with baseline CD4 cell counts of 201-350 cells/μl, and 652(537-767) cells/μl among those with baseline CD4 cell counts >350 cells/μl. Higher baseline CD4 cell counts and being male were independently associated with the risk of immunological non-response at 12 months. Furthermore, it was also investigated that these factors were significant predictors of subsequent CD4 cell recovery.Patients with higher baseline CD4 cell stratum returned to normal CD4 Cell counts though they had an increased risk of immunological non-response at 12 months compared to those with the least baseline CD4 cell stratum. The findings suggest that consideration be given to initiation of HAART at a CD4 cell count >350 cells/μl to achieve better immune recovery, and to HIV-infected male patients to improve their health seeking behavior
Results of multivariate logistic regression of independent variables and antipsychotic medication adherence.
No full text<p><sup>1</sup>Adjusted for age, marital status, education status, residence, employment status, alcohol consumption, cigarette smoking, khat chewing, treatment attitudes, medication side effects, satisfaction with medication, relabel symptoms and awareness of illness.</p><p>Results of multivariate logistic regression of independent variables and antipsychotic medication adherence.</p
Socio-demographic characteristics of study participants.
No full text<p>Exchange rate: 1 USD = 19.82 Ethiopian Birr (ETB).</p><p>Socio-demographic characteristics of study participants.</p
Attitudes, medication side effects, satisfaction with medication, and insight.
No full text<p>Higher score indicates a</p><p><sup>1</sup>more positive attitude towards treatment but negative value indicates negative attitude towards treatment,</p><p><sup>2</sup>more severe side effect,</p><p><sup>3</sup>more satisfaction with medication, and</p><p><sup>4</sup>greater insight.</p><p>Attitudes, medication side effects, satisfaction with medication, and insight.</p
Illustrations of fitness seascapes and mutant selection windows.
No full text(A) Example fitness seascape parameterized with random dose-response data. Genotypes are modeled with binary strings, where ‘0’ represent the absence of a point mutation at a specific position and ‘1’ represents the presence of said mutation. Corresponding rank-order fitness landscapes are annotated at 10−2 and 102 μg/mL. (B) Example patient serum drug concentration profile over time for a single drug dose. The mutant selection window range is annotated in gray, while the time the serum drug concentration resides within the mutant selection window, tMSW, is shown in blue.</p
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