Spatial and temporal variation in crop diversity in agroforestry homegardens of southern Ethiopia

A key assumption in many homegarden studies is that homegardens are ecologically and socio-economically sustainable due to their species diversity. The precise relation between diversity and sustainability is still heavily debated, however. A basic question is how diversity in homegardens can best be characterized in view of the various dimensions of species diversity and their variation in time and space. This paper assesses different types of species diversity in the homegardens of Sidama region of southern Ethiopia. In a survey of crop species in 144 homegardens a total of 78 cultivated crop species (excluding trees) belonging to 10 functional groups were recorded; there were on average 16 crop species and 8 functional groups per farm. Within homegardens, plots differ in species composition and crop diversity. Four types of homegarden systems are distinguished differing in both type and area-share of dominant species, relative orientation at subsistence or cash production and overall crop diversity. The gradual replacement of enset by maize and of coffee by more financially attractive cash crops khat and pineapple causes a decrease in overall crop diversity. Our data demonstrate that it is incorrect to consider homegardens as generic systems with a uniform distribution of species diversity: important within and between homegarden variation exists. Ecological and socio-economic sustainability is not just related to species diversity per se, but rather to more specific features such as presence of keystone species and diversity in functional species groups. Socio-economic sustainability in terms of adjustment to socio-economic change implies dynamics in species diversit

Variation in the use of definitive treatment options in the management of Graves' disease: a UK clinician survey

Background: Graves’ disease can be treated with antithyroid drugs (ATDs), radioiodine or surgery. Use of definitive treatments (radioiodine or surgery) varies widely across centres. Specific clinical circumstances, local facilities, patient and clinician preferences and perceptions will affect choice of treatment. Detailed understanding of UK clinicians’ views and their rationale for different treatments is lacking. Aims: To study the preferences and perceptions of UK clinicians on the role of surgery and radioiodine in the management of Graves’ disease. Methods: British Thyroid Association’ (BTA), ‘Society for Endocrinology’ (SFE) and ‘British Association of Endocrine and Thyroid Surgeons’ (BAETS) members were invited to complete an online survey examining their management decisions in Graves’ disease and factors that influenced their decisions. Results: 158 responses from UK consultants were included. The ratio of physicians to surgeons was 11:5 and males to females was 12:4. Most clinicians would commence ATDs in uncomplicated first presentation of Graves’ disease. A wide range of risk estimates on the effectiveness and risks of treatment was given by clinicians. Radioiodine was used most frequently in relapsed Graves’ disease. However severe eye disease and pregnancy strongly influenced choice in favour of surgery. Surgeons underestimated the success of radioiodine (P<0.01) and were more likely to recommend thyroidectomy than physicians. Conclusions: This survey demonstrates significant variation in clinicians’ perceptions of risks of treatment and their choice of management options for relapsed Graves’ disease. The variation appeared to be dependent on patient and disease specific factors as well as physician experience, gender and speciality

Impact of month of birth on the development of autoimmune thyroid disease in the United Kingdom and Europe

CONTEXT: Viral/bacterial infection is proposed as a trigger for the autoimmune thyroid diseases (AITD): Graves' disease (GD) and Hashimoto's thyroiditis (HT). Previous studies in European Caucasian AITD subjects found higher birth rates in the autumn/winter, suggesting those born in the autumn/winter experience increased viral/bacterial exposure after birth, impacting upon immune system development and predisposing to AITD later in life. OBJECTIVE: Month of birth effects were investigated in three independent European Caucasian AITD datasets. DESIGN: Variation in GD and HT onset was compared across months and seasons, with fluctuations across all 12 months analyzed using a Walter-Elwood test. SETTING: The study was conducted at a research laboratory. PATIENTS: National UK Caucasian AITD Case Control Collection (2746 GD and 502 HT compared with 1 423 716 UK births), National UK Caucasian GD Family Collection (239 GD and 227 unaffected siblings), and OXAGEN AITD Caucasian Family Collection (885 GD, 717 HT, and 794 unaffected siblings of European Caucasian decent). MAIN OUTCOME MEASURES: Case-control and family-based association studies were measured. RESULTS: No consistent month of birth effects were detected in GD females or males across all three collections. In HT females from the OXAGEN AITD Caucasian Family Collection, slightly higher birth rates were detected in autumn (Walter's test statistic = 7.47, P = .024) however, this was not seen in the HT females from the case-control cohort. CONCLUSION: Our results suggest in UK/Northern European Caucasian GD subjects, month of birth does not impact on AITD development. Although some month of birth effects for HT females in one collection cannot be excluded, only further work in larger European Caucasian AITD collections can confirm these effects