98 research outputs found

    The Genomic Signature of Crop-Wild Introgression in Maize

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    The evolutionary significance of hybridization and subsequent introgression has long been appreciated, but evaluation of the genome-wide effects of these phenomena has only recently become possible. Crop-wild study systems represent ideal opportunities to examine evolution through hybridization. For example, maize and the conspecific wild teosinte Zea mays ssp. mexicana, (hereafter, mexicana) are known to hybridize in the fields of highland Mexico. Despite widespread evidence of gene flow, maize and mexicana maintain distinct morphologies and have done so in sympatry for thousands of years. Neither the genomic extent nor the evolutionary importance of introgression between these taxa is understood. In this study we assessed patterns of genome-wide introgression based on 39,029 single nucleotide polymorphisms genotyped in 189 individuals from nine sympatric maize-mexicana populations and reference allopatric populations. While portions of the maize and mexicana genomes were particularly resistant to introgression (notably near known cross-incompatibility and domestication loci), we detected widespread evidence for introgression in both directions of gene flow. Through further characterization of these regions and preliminary growth chamber experiments, we found evidence suggestive of the incorporation of adaptive mexicana alleles into maize during its expansion to the highlands of central Mexico. In contrast, very little evidence was found for adaptive introgression from maize to mexicana. The methods we have applied here can be replicated widely, and such analyses have the potential to greatly informing our understanding of evolution through introgressive hybridization. Crop species, due to their exceptional genomic resources and frequent histories of spread into sympatry with relatives, should be particularly influential in these studies

    Eribulin treatment for patients with metastatic breast cancer:The United Kingdom experience - a multicenter retrospective study

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    Introduction: This study examined real-world data from patients who received eribulin for metastatic breast cancer (MBC) collected from 14 hospitals across the UK. Methods: Anonymized data were collected retrospectively from patients with MBC who had received eribulin. The data included the hormone-receptor status, histological diagnosis, age, prior chemotherapy, response to eribulin, progression-free survival (PFS), and overall survival (OS). Results: Among 577 patients analyzed, the median age was 56 years, and most patients (73%) were estrogen-receptor positive. The median OS was 288 days (95% confidence interval [CI]: 261–315), and the PFS was 117 days (95% CI: 105–129). The median OS was higher among older patients (≥65 vs. p = 0.028). The median OS was also higher in patients who received eribulin after fewer prior lines of chemotherapy (≤2 vs. >2 prior: 328 days [95% CI: 264–385] vs. 264 days [95% CI: 229–298]; p = 0.042). Discussion/Conclusion: These retrospective data suggest that eribulin can be successfully used in older patients with MBC. Eribulin treatment was more effective in earlier-line settings, which, while predictable, supports consideration of eribulin as a second-line treatment option. </p

    Quality of life after postmastectomy radiotherapy in patients with intermediate-risk breast cancer (SUPREMO): 2-year follow-up results of a randomised controlled trial

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    Background Postmastectomy radiotherapy in patients with four or more positive axillary nodes reduces breast cancer mortality, but its role in patients with one to three involved nodes is controversial. We assessed the effects of postmastectomy radiotherapy on quality of life (QOL) in women with intermediate-risk breast cancer. Methods SUPREMO is an open-label, international, parallel-group, randomised, controlled trial. Women aged 18 years or older with intermediate-risk breast cancer (defined as pT1–2N1; pT3N0; or pT2N0 if also grade III or with lymphovascular invasion) who had undergone mastectomy and, if node positive, axillary surgery, were randomly assigned (1:1) to receive chest wall radiotherapy (50 Gy in 25 fractions or a radiobiologically equivalent dose of 45 Gy in 20 fractions or 40 Gy in 15 fractions) or no radiotherapy. Randomisation was done with permuted blocks of varying block length, and stratified by centre, without masking of patients or investigators. The primary endpoint is 10-year overall survival. Here, we present 2-year results of QOL (a prespecified secondary endpoint). The QOL substudy, open to all UK patients, consists of questionnaires (European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-BR23, Body Image Scale, Hospital Anxiety and Depression Scale [HADS], and EQ-5D-3L) completed before randomisation, and at 1, 2, 5, and 10 years. The prespecified primary outcomes within this QOL substudy were global QOL, fatigue, physical function, chest wall symptoms, shoulder and arm symptoms, body image, and anxiety and depression. Data were analysed by intention to treat, using repeated mixed-effects methods. This trial is registered with the ISRCTN registry, number ISRCTN61145589. Findings Between Aug 4, 2006, and April 29, 2013, 1688 patients were enrolled internationally and randomly assigned to receive chest wall radiotherapy (n=853) or not (n=835). 989 (79%) of 1258 patients from 111 UK centres consented to participate in the QOL substudy (487 in the radiotherapy group and 502 in the no radiotherapy group), of whom 947 (96%) returned the baseline questionnaires and were included in the analysis (radiotherapy, n=471; no radiotherapy, n=476). At up to 2 years, chest wall symptoms were worse in the radiotherapy group than in the no radiotherapy group (mean score 14·1 [SD 15·8] in the radiotherapy group vs 11·6 [14·6] in the no radiotherapy group; effect estimate 2·17, 95% CI 0·40–3·94; p=0·016); however, there was an improvement in both groups between years 1 and 2 (visit effect −1·34, 95% CI −2·36 to −0·31; p=0·010). No differences were seen between treatment groups in arm and shoulder symptoms, body image, fatigue, overall QOL, physical function, or anxiety or depression scores. Interpretation Postmastectomy radiotherapy led to more local (chest wall) symptoms up to 2 years postrandomisation compared with no radiotherapy, but the difference between groups was small. These data will inform shared decision making while we await survival (trial primary endpoint) results. Funding Medical Research Council, European Organisation for Research and Treatment of Cancer, Cancer Australia, Dutch Cancer Society, Trustees of Hong Kong and Shanghai Banking Corporation

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    Not AvailableThe mango fruits remain biologically active even after harvest as they continue respiration, transpiration and other bio-chemical processes. Being highly perishable, the fruit quality deteriorates fast under ambient conditions (30 ± 5 C and 50 ± 5% RH), rendering them unmarketable within 5–6 days. In order to extend the shelf-life of ‘Amrapali’ mango fruits, we have treated them with three different concentrations (500, 750 and 1000 ppb) of 1-Methylcyclopropene (1-MCP) @ 20 C and stored at ambient conditions. Among all the treatments, 1000 ppbwas found to be an effective in extending shelf-life till twelfth day with minimum physiological loss in weight (19.24%), maximum firmness (10.43 N), highest retention of quality parameters such as soluble solid concentrates (27.88 B), ascorbic acid (28.49 mg 100 g-1 FW) and total antioxidant activity (675.41 lmol Trolox g-1 FW) compared to untreated mango fruits (21.79%, 5.45 N, 23.17 B, 19.55 mg 100 g-1 FW and 265.41 lmol Trolox g-1 FW, respectively). Gene expression studies have revealed that the texture related gene expansin was significantly repressed till fifth day of storage with increasing concentrations of 1-MCP.Not Availabl

    CYTOLOGICAL EFFECTS OF MICROWAVE RADIATION IN CHINESE HAMSTER CELLS <i>IN VITRO</i>

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    Cytological effects were investigated in the Chinese hamster cell line (CHO-K1) exposed to microwave radiation of 2450 MHz frequency and incident power of 25 to 200 W for a period of 30 min. Nuclear vacuoles, pycnotic and decondensed chromosomes were observed in cells exposed to 25 W under elevated temperature conditions (uncontrolled temp). In addition a significant increase in chromosomal breakages/cell was observed. Cells exposed to relatively higher power, 75-200 W, under hypothermic conditions (29 °C) revealed no significant increase in either nuclear vacuoles or other chromosomal anomalies over control cells. Radiation-induced temperature elevation appears to be an essential factor in the cytological effects of microwave. </jats:p

    Quiz gaming competitions for undergraduate medical students: Questioning the MediQuiz

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    Many medical schools worldwide incorporate a quiz competition centered around medical subjects as part of their extracurricular activities. This ‘MediQuiz’ is distinct from scheduled formal curricular quiz assessments, and is usually characterized by festive informality, as a quizmaster conducts it on stage before an audience Studies have shown that such quiz games promote active learning, and provide motivational impetus. They also enhance meaningful knowledge retention by igniting interest and placing theoretical subjects in a real-world perspective. Questions about medical subjects can be either ‘interesting’ (general knowledge or ‘trivia’), or ‘useful’ (suitable for a viva voce assessment). For the purposes of this study (and to avoid cognitive bias) these have been classed as extracurricular and curricular questions. This study polled students at five such quizzes and attempts to find out the optimal balance of education and entertainment that quizmasters should aim for. It also assessed students’ perceptions of stress, bias, equity, usefulness and relevance of such ‘edutainment’ exercises. That game-styled quiz competitions based on curricular subjects can be an effective tool to increase interest and motivation and enhance learning is established beyond doubt. Students overall preferred a predominance of questions from outside their textbooks over examination-type questions. This preference for extracurricular questions was slightly stronger among the audience, in students with prior quiz experience, and among foreign students and male students. Participants reported that stress levels were very high on stage, but felt it to be character building as they also learnt to deal with anxiety, to work as a team and to develop a healthy competitive spirit. Most of the audience felt that the mediquiz showed that learning could be fun.Key words: Mediquiz; Medical school; Mauritius; Questionnaire; Medical quiz game; Extracurricular questio
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