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Poultry production is an important way of enhancing the livelihoods of rural populations, especially in low- and middle-income countries (LMICs). As poultry production in LMICs remains dominated by backyard systems with low inputs and low outputs, considerable yield gaps exist. Intensification can increase poultry productivity, production and income. This process is relatively recent in LMICs compared to high-income countries. The management practices and the constraints faced by smallholders trying to scale-up their production, in the early stages of intensification, are poorly understood and described. We thus investigated the features of the small-scale commercial chicken sector in a rural area distant from major production centres. We surveyed 111 commercial chicken farms in Kenya in 2016. We targeted farms that sell the majority of their production, owning at least 50 chickens, partly or wholly confined and provided with feeds. We developed a typology of semi-intensive farms. Farms were found mainly to raise dual-purpose chickens of local and improved breeds, in association with crops and were not specialized in any single product or market. We identified four types of semi-intensive farms that were characterized based on two groups of variables related to intensification and accessibility: (i) remote, small-scale old farms, with small flocks, growing a lot of their own feed; (ii) medium-scale, old farms with a larger flock and well located in relation to markets and (iii) large-scale recently established farms, with large flocks, (iii-a) well located and buying chicks from third-party providers and (iii-b) remotely located and hatching their own chicks. The semi-intensive farms we surveyed were highly heterogeneous in terms of size, age, accessibility, management, opportunities and challenges. Farm location affects market access and influences the opportunities available to farmers, resulting in further diversity in farm profiles. The future of these semi-intensive farms could be compromised by several factors, including the competition with large-scale intensive farmers and with importations. Our study suggests that intensification trajectories in rural areas of LMICs are potentially complex, diverse and non-linear. A better understanding of intensification trajectories should, however, be based on longitudinal data. This could, in turn, help designing interventions to support small-scale farmers.
Scanning tunneling microscopy and spectroscopy (STM/STS) are used to electronically switch atomically-thin memristors, referred to as “atomristors”, based on a graphene/molybdenum disulfide (MoS2)/Au heterostructure. A gold-assisted exfoliation method was used to produce near-millimeter (mm) scale MoS2 on Au thin-film substrates, followed by transfer of a separately exfoliated graphene top layer. Our results reveal that it is possible to switch the conductivity of a graphene/MoS2/Au memristor stack using an STM tip. These results provide a path to further studies of atomically-thin memristors fabricated from heterostructures of two-dimensional materials such as graphene and transition metal dichalcogenides (TMDs).
The Foodborne Diseases Active Surveillance Network (FoodNet) conducts population-based surveillance for Campylobacter infection. For 2010 through 2015, we compared patients with Campylobacter jejuni with patients with infections caused by other Campylobacter species. Campylobacter coli patients were more often >40 years of age (OR = 1·4), Asian (OR = 2·3), or Black (OR = 1·7), and more likely to live in an urban area (OR = 1·2), report international travel (OR = 1·5), and have infection in autumn or winter (OR = 1·2). Campylobacter upsaliensis patients were more likely female (OR = 1·6), Hispanic (OR = 1·6), have a blood isolate (OR = 2·8), and have an infection in autumn or winter (OR = 1·7). Campylobacter lari patients were more likely to be >40 years of age (OR = 2·9) and have an infection in autumn or winter (OR = 1·7). Campylobacter fetus patients were more likely male (OR = 3·1), hospitalized (OR = 3·5), and have a blood isolate (OR = 44·1). International travel was associated with antimicrobial-resistant C. jejuni (OR = 12·5) and C. coli (OR = 12) infections. Species-level data are useful in understanding epidemiology, sources, and resistance of infections.
Control of glyphosate-resistant (GR) horseweed in soybean with glyphosate (900 g ai ha−1) plus saflufenacil (25 gaiha−1) has been variable. The objective of this research was to determine the effect of GR horseweed height, density, and time of day (TOD) at application on saflufenacil plus glyphosate efficacy in soybean. All experiments were completed six times during a 2 yr period (2014, 2015) in fields previously confirmed with GR horseweed. Applications from 0900 to 2100 hours provided optimal control of GR horseweed 8 WAA. Soybean yield paralleled GR horseweed control with the highest yield of 3000kgha−1 at 1500 hours, and the lowest yield of 2400kgha−1 at 0600 hours. The height and density of GR horseweed at application had minimal effect on saflufenacil efficacy. Saflufenacil provided>99% control of GR horseweed when applied to small plants and low densities; however, control decreased to 95% when>25 cm tall, and to 96% in densities>800 plants m−2 at 6 WAA due to some plant regrowth. TOD of application had a greater influence on GR horseweed control with saflufenacil than height or density. To optimize control of GR horseweed, saflufenacil should be applied during daytime hours to small plants at low densities. Optimizing GR horseweed control minimizes weed seed return and weed interference.
The control of glyphosate-resistant (GR) horseweed (Conyza canadensis) in soybean has been variable with glyphosate plus saflufenacil. The objective of this research was to determine the biologically effective rate (BER) of saflufenacil, saflufenacil mixed with glyphosate, and metribuzin mixed with saflufenacil and glyphosate applied preplant (PP) for the control of GR horseweed in no-till soybean; a study was conducted to determine each of the three treatments. For each study, seven field sites infested with GR horseweed were used over a 2-yr period (2014, 2015). Saflufenacil alone at 25 and 36 g ai ha–1 provided 90 and 95% control of GR Horseweed 8 wk after application, while the BER to achieve 98% control was outside of the treatment range tested. The saflufenacil plus glyphosate (900 g ai ha–1) BER experiment found less saflufenacil was required as 25, 34, and 47 g ha–1 provided 90, 95, and 98% control of GR horseweed respectively. The metribuzin BER experiment found 61, 261, and 572 g ha–1 was required to provide 90, 95 and 98% control of GR horseweed, respectively, mixed with saflufenacil (25 g ha–1) and glyphosate (900 g ha–1). The addition of metribuzin with the recommended rate of saflufenacil (25 g ha–1) plus glyphosate improved control and a second effective herbicide mode of action for the control of GR horseweed. The use of a threeway herbicide mixture can be an effective weed management strategy to control GR horseweed in soybean.
We present an overview of the survey for radio emission from active stars that has been in progress for the last six years using the observatories at Fleurs, Molonglo, Parkes and Tidbinbilla. The role of complementary optical observations at the Anglo-Australian Observatory, Mount Burnett, Mount Stromlo and Siding Spring Observatories and Mount Tamborine are also outlined. We describe the different types of star that have been included in our survey and discuss some of the problems in making the radio observations.