Controlled biomineralization of magnetite (Fe₃O₄) by <i>Magnetospirillum gryphiswaldense</i>

Results from a study of the chemical composition and micro-structural characteristics of bacterial magnetosomes extracted from the magnetotactic bacterial strain Magnetospirillum gryphiswaldense are presented here. Using high-resolution transmission electron microscopy combined with selected-area electron diffraction and energy dispersive X-ray microanalysis, biogenic magnetite particles isolated from mature cultures were analysed for variations in crystallinity and particle size, as well as chain character and length. The analysed crystals showed a narrow size range (∼14-67 nm) with an average diameter of 46±6.8 nm, cuboctahedral morphologies and typical Gamma type crystal size distributions. The magnetite particles exhibited a high chemical purity (exclusively Fe3O4) and the majority fall within the single-magnetic-domain range

Soil Survey of Iowa, Report No. 76—Hancock County Soils

Hancock County is located in north central Iowa in the second tier of counties south of the Minnesota state line and in the middle tier of counties from east to west in the state. It lies entirely in the Wisconsin drift soil area, and hence its soils are all of drift or glacial origin

Intra-tester and inter-tester reliability of the MicroFET 3 hand-held dynamometer.

Background: The reliability of the MicroFET 3 has not previously been reported in the literature. The aim of this study was to evaluate intra-tester and inter-tester reliability of the MicroFET3 hand-held dynamometer (HHD) in three lower limb muscle groups. Methods: Maximum voluntary isometric contraction (MVIC) of hip extension, knee extension and ankle plantar-flexion were measured in 38 healthy participants (males=18, females= 20) by two testers on separate days using the MicroFET3 HHD. The reliability analysis was carried out using intra-class correlation coefficients (ICCs) to measure association and Band and Altman plots to demonstrate agreement. Results: The results showed that intra-tester reliability was moderate to excellent; with associations ranging from ICC 0.56 - 0.92 and higher agreement for knee and ankle than hip measurements was shown. Inter-tester reliability was lower, with hip and knee associations ranging from ICC 0.60 - 0.66. Ankle measurements intertester associations were particularly low (ICC 0.23 and 0.15). These values would not be considered acceptable for clinical use. Bland and Altman plots used to demonstrate agreement between testers displayed a considerable lack of agreement with discrepancies of up to 150N noted in measurements. Conclusion: The results suggest that the MicroFET3 HHD displayed moderate to excellent intra-tester reliability and poor to moderate inter-tester reliability and agreement with discrepancies noted between muscle groups. While use of this instrument can be recommended when consistently used by a single tester, further reliability analysis should be carried out before this instrument could be recommended for use by different testers in the clinical setting

Diversification for climate change resilience: Participatory assessment of opportunities for diversifying agroecosystems

This guidebook presents an assessment method to identify opportunities for diversifying agroecosystems to strengthen climate change resilience. The assessment draws on participatory research approaches to describe local agrobiodiversity and support its conservation and revival. The assessment can be conducted with large or small groups of farmers to understand the effects of climate change, assess local diversity and management practices, and explore diversification options. Opportunities for diversification are identified based on an analysis of gaps in the farm portfolio and recognition of species, varieties, breeds, landscape features, and management practices that support resilience. The assessment is simple by design to be accessible to farmers and “non-experts”, who can adapt and apply the method independently or with supporting NGOs, extension agents, or development actors. In this guidebook, the diversification assessment method is presented along with results and reflections from the pilot sites. The assessment was piloted in 2017 with communities in Guatemala, India, and Mali. Examples from the pilot sites presented throughout the guidebook illustrate how each step is conducted in practice and the type of information and conclusions that can be drawn from the results. We hope that this guidebook will support community efforts to diversify their fields, farms, and landscapes for improved resilience

Value chain analysis of Chaya (Mayan Spinach) in Guatemala

Chaya is a highly nutritious perennial leafy vegetable native to Mesoamerica. This drought-resistant crop has low production and consumption levels in Guatemala, but has the potential to help agriculture and food systems be more nutritious and resilient. This study analyzed the value chain of chaya in Guatemala, and identified bottlenecks and opportunities for its use-enhancement. This research, the first of its kind applied to this crop in Guatemala, combined Rapid Market Appraisal tools. Small-scale chaya production, consumption, and marketing were observed in three focal sites (Guatemala City, Petén, and Dry Corridor). It was observed that producers are not motivated to produce chaya commercially and vendors are unwilling to sell it because of low demand and profitability. One Guatemalan company identified produces nutraceutical chaya products with few sales points in the country and occasionally abroad. Low demand is a primary bottleneck in the value chain due to lack of consumer awareness, changing eating habits, limited recipes, and availability in home-gardens. There is also a reluctance to grow, consume, or sell a crop perceived as a “food of the poor.” Low prices and profitability were other constraints registered. The findings can inform future interventions for enhancing the use of this crop to fight malnutrition

Climate change and crop diversity: farmers’ perceptions and adaptation on the Bolivian Altiplano

Crop diversity is central to traditional risk management practices on the Andean Altiplano and may find renewed importance in adapting to climate change. This study explored the role of crop diversity in farmers’ adaptation actions in eight Aymara communities on the northern Bolivian Altiplano. Using a combination of quantitative and qualitative methods, including multifactor analysis and a community resilience self-assessment, we investigated how farmers’ use of diversity in adaptation is related to their perceptions of crop and variety tolerances and other environmental, social, and economic factors. Few crops and varieties were perceived as tolerant to increasingly intense and unpredictable drought, frost, hail, and pest and disease outbreaks. Some local crops and varieties were perceived as vulnerable to emerging conditions (e.g. oca, papalisa, isaño), whereas bitter potatoes and wild relatives of quinoa and cañahua were perceived as highly stress tolerant and provide food in harsh periods. A total 19% of households surveyed (N = 193) had introduced new crops or varieties—often disease resistant or early maturing—as an adaptive action. Introduction of commercial crops was a common adaptation action, reflecting farmers’ response to warming temperatures and changing economic opportunities, but greater sensitivity of the introduced crops may cause maladaptation. Despite intensification of cropping systems, households continue to maintain a median four potato varieties with different tolerance traits, yet this risk management practice was not perceived as adaptation. Strengthening resilience will require a combination of actions, including maintaining and expanding crop portfolios and restoring soil and ecosystem health, using both traditional and innovative approaches

Issues and prospects for the sustainable use and conservation of cultivated vegetable diversity for more nutrition-sensitive agriculture

Traditional vegetables are key assets for supporting more nutrition-sensitive agriculture under climate change as many have lower water requirements, adaptation to poor quality soils, higher resistance to pests and diseases, and higher nutritional values as compared to global vegetables. The effective use of traditional vegetables can be challenged however by lack of information and poor conservation status. This study reviewed the uses, growth forms and geographic origins of cultivated vegetables worldwide and the levels of research, ex situ conservation, and documentation they have received in order to identify gaps and priorities for supporting more effective use of global vegetable diversity. A total of 1097 vegetables were identified in a review of the Mansfeld Encyclopedia of Agricultural and Horticultural Plants, including species used for leaves (n = 495), multiple vegetative parts (n = 227), roots (n = 204), fruits or seeds (n = 90), and other parts like flowers, inflorescences, and stems (n = 81). Root vegetables have received significantly less research attention than other types of vegetable. Therophytes (annuals) have received significantly more attention from research and conservation efforts than vegetables with other growth forms, while vegetables originating in Africa (n = 406) and the Asian-Pacific region (n = 165) are notably neglected. Documentation for most vegetable species is poor and the conservation of many vegetables is largely realized on farm through continued use. Supportive policies are needed to advance research, conservation, and documentation of neglected vegetable species to protect and further their role in nutrition-sensitive agriculture

Resumen de investigación: Cadena de valor y potencial de mercado de la chaya para fortalecer la resiliencia climática, seguridad nutricional e ingresos en Guatemala

El análisis de la cadena de valor de la chaya fue realizado por Nadezda Amaya como parte del programa internacional Integrando cadenas de valor agro-biodiversas, cambio climático y nutrición: empoderando a los pobres para manejar mejor el riesgo" respaldado por el Fondo Internacional de Desarrollo Agrícola (FIDA), la Unión Europea (UE) y Programas de investigación del CGIAR sobre Cambio Climático, Agricultura y Seguridad Alimentaria (CCAFS) y Agricultura para la Nutrición y la Salud (A4NH)