Golden Rice and technology adoption theory: A study of seed choice dynamics among rice growers in the Philippines

Golden Rice (GR) is a much-debated transgenic crop. Many commentaries and economic analyses have assumed that, if and when the new GR varieties are released, the grains will automatically find their way onto the plates of children in especially poor families who are at risk of vitamin A deficiency (VAD). But many of these families are not rice growers or are unlikely to adopt the varieties into which the transgenic trait has been bred. This raises the neglected question addressed in this paper: How likely is it that commercial rice growers will choose to plant GR varieties? To examine this question, we draw upon and contribute to a wider literature on what drives farmers’ seed selection practices. Seed choice has been a frequent case in the elaboration of technology adoption theory. We apply a recently proposed tripartite model of learning, and present new survey data to shed light on the dynamics of seed choice and variety replacement rates among rice farmers in two sites in Nueva Ecija, Luzon, the Philippines. We compare our findings with previous research on the seed choices of Indian cotton and rice farmers in Warangal, Telangana, India. Seed choices in Nueva Ecija show a moderate degree of faddishness and herding behaviour, and the varieties in which the GR trait are expected to be available have declined in popularity. Farmers here show a modest and variable susceptibility to persuasion by external parties that seek to promote specific rice varieties. Our study suggests that commercial rice farmers may not choose to plant GR varieties unless they are offered specific inducements to do so.     

Impact of scale on the effectiveness of disease control strategies for epidemics with cryptic infection in a dynamical landscape: an example for a crop disease.

We use a spatially explicit, stochastic model to analyse the effectiveness of different scales of local control strategies in containing the long-term, multi-seasonal spread of a crop disease through a dynamically changing population of susceptible crops in which there is cryptic infection. The model distinguishes between susceptible, infested and symptomatic fields. It is motivated by rhizomania disease on sugar beet in the UK as an exemplar of a spatially structured and partially asymptomatic epidemic. Our results show the importance of matching the scales of local control strategies to prevent intensification and regional spread of disease with the inherent temporal and spatial scales of an epidemic. A simple field-scale containment strategy, whereby the susceptible crop is no longer grown on fields showing symptoms, fails for this system with cryptic infection because the locally applied control lags behind the epidemic. A farm-scale strategy, whereby growers respond to the disease status of neighbouring farms by transferring their quota for sugar beet to farmers in regions of reduced risk, succeeds. We conclude that a soil-borne pathogen such as rhizomania could be managed by movement of susceptible crops in the landscape using a strategy that matches the temporal and spatial scales of the epidemic and which take account of risk aversion among growers. We show some parallels and differences in effectiveness between a 'culling' strategy involving crop removal around emerging foci and the local deployment of partially resistant varieties that reduce amplification and transmission of inoculum. Some relationships between the control of plant and livestock diseases are briefly discussed.     

GOOD SUBJECTS,BAD OBJECTS

This article discusses the material culture of the commercial photography studio in nineteenth-century America, examining a succession of objects that made portrait photographs work: technologically, by controlling and shaping bodily movement in order to meet the shifting demands of photographic apparatuses, but also socially, by helping to construct and display bodies in culturally appropriate and putatively revealing ways. It focuses on three varieties of photographic objects, which appeared in studios in roughly chronological order: first, the ubiquitous and much-discussed head rest; second, purpose-built photographic furniture; and third, supplementary accessories intended to produce photogenic states of absorption. Taken together, these materials — and contemporaries’ responses to them — demonstrate how early commercial portrait photographers and their subjects understood photography’s capacity to represent the body and to mediate social identity. They also demonstrate how, through bodily expression aided by industrially produced objects and calibrated to anticipated spectators, contemporaries negotiated and normalized rapid changes in imaging technologies in modernity, and exploited the possibilities that modern visual media offered for the presentation of the self.     

Simultaneous monitoring of organic acids and sugars in fresh and processed apple juice by Fourier transform infrared-attenuated total reflection spectroscopy

A combination of Fourier transform infrared spectroscopy (FT-IR) and chemometrics was used as a screening tool for the determination of sugars and organic acids such as sucrose, glucose, fructose, sorbitol, citric acid, and malic acid in processed commercial and extracted fresh apple juices. Prepared samples of synthetic apple juice in different constituent concentration ranges were scanned by attenuated total reflectance (ATR) accessory and the spectral region in the range between 950 and 1500 cm(-1) was selected for calibration model development using partial least squares (PLS) regression and principal component regression (PCR). The calibration models were successfully validated by high-performance liquid chromatography (HPLC) measurements against several commercial juice varieties as well as juice extracted from different apple varieties to provide an overall R2 correlation of 0.998. The present study demonstrates that Fourier transform infrared spectroscopy could be used for rapid and nondestructive determination of multiple constituents in commercial and fresh apple juices. Results indicate this approach to be a rapid and cost-effective tool for routine monitoring of multiple constituents in a fruit juice production facility.     

我国农作物病虫害防治服务质量技术规范研究

本研究针对我国农作物病虫害专业化防治服务行业的客观需求,提出了农作物病虫害防治服务质量技术规范的制定原则、技术框架、内容要素及技术要求,为提升我国农作物病虫害防治专业服务组织的服务质量、服务能力和服务水平提供了参考依据.     

Exploitation of poor Greek kaolins: Durability of metakaolin concrete

In this paper the effect of metakaolin on concrete durability is investigated. A Greek kaolin of low kaolinite content was thermally treated at defined conditions and the produced metakaolin was finely ground. In addition, a commercial metakaolin of high purity was used. Eight mixture proportions were used to produce high performance concrete, where metakaolin replaced either cement or sand in percentages 10% or 20% by weight of the control cement content. Durability of metakaolin concrete was evaluated by means of resistance to chloride penetration, air permeability, sorptivity, porosity and pore size distribution. Metakaolin concrete exhibits significantly lower chloride permeability, gas permeability and sorptivity. The addition of metakaolin refines the pore system of concrete, leading to a decreased mean pore size and improved uniformity of the pore size distribution. The produced metakaolin, derived from the poor Greek kaolin, imparts similar behavior to that of the commercial metakaolin, with respect to the concrete durability.     

Dissemination strategies and the adoption of improved agricultural technologies: The case of improved cassava varieties in Ghana

Cassava (Manihot esculanta Crantz) is an important tropical root crop for food security and national economies in Africa. In Ghana, it is the most important staple food also used in breweries, bakery and confectionery industries. Several high-yielding and disease resistant improved cassava varieties (ICVs) have been released and are being promoted through diverse dissemination channels. Past studies investigate the role of information in the adoption of agricultural technologies without accounting for the diversity in the dissemination strategies. The paper explores the diversity of dissemination strategies in examining the adoption of improved cassava varieties using a sequential mixed-method approach which combines exploratory interviews and focus group discussions with a questionnaire-based quantitative survey and the Cragg's two-part model. The paper uses data collected from 608 farmers randomly selected from major cassava producing communities in the Ashanti and Brong-Ahafo regions in Ghana, West Africa. The results show statistically significant and identical impact of information through demonstrations, distribution of planting materials, farmer-to-farmer and media on the probability of ICV adoption. Other drivers of adoption are the membership of farmers based organizations (FBO), planting of two or more varieties and having large livestock size. However, ICV adoption and intensity was hampered by household size, distances to the nearest tarred road and market, and grey-skin color. These attributes need to be integral of dissemination campaigns for cassava variety adoption.     

Characteristics of the publishing infrastructure of peripheral countries: A comparison of periodical publications from Latin America with periodicals from the US and the UK

Bibliometric research can provide science policy makers with indicators of the capacity of a country's national scientific system to produce printed information. The capacity of the local publishing industry to produce scientific and technical periodical publications reflects the availability of outlets for the dissemination of scientific findings. The present research attempts to evaluate the role of the publishing industry in the level of bibliographic control, and the level of peer review of periodical publications from Latin America. A random search was performed on the 1990 Cd-Rom version ofThe Serials Directory, a commercially produced international reference source on periodical publications. A sample of 311 periodicals from Latin America was downloaded to a local database. A similar search was performed on publications from the United States and the United Kingdom for comparison purposes. A random search of 235 publications was downloaded into a local database. Publishers were classified for both samples according to three types: academic, governmental, and commercial. Publications were sorted thematically and indicators of bibliographic control, and of peer review were recorded for both samples. Publications from Latin America showed a very low level of bibliographic control, particularly in the case of the assignment of ISSN numbers, where 58% of the sample studied was published without this element of bibliographic control. This contrasted sharply with the periodicals from the US and UK, where 83% (195) journals had an ISSN number assigned. The involvement of editorial boards in the academic quality of Latin American publications amounted only to 21% of the sample studied. Periodicals from the US and UK reported an editor as responsible for the journal in 40% (93) of the cases. This amount constitutes about double the number of editors reported by Latin American publications. Latin American academic publishers are the most numerous publishers in the sample studied accounting for 37% (114) of the journals studied however, 68% (77) of those editors printed periodicals without a named editor. Governmental publishers are the second largest publisher type. They produced 29% (89) of the journals in the sample. Commercial publishers are responsible for 26% (82) of the journals studied. Publications from the US and UK show a clear predominance of commercial publishers, accounting for 47% (111) of the journals. Academic publishers only produced 29% (68) of the 235 journals in the sample. This clear dominance of the commercial publisher sector shows that publishing in at least the two countries studied is clearly practised as a business enterprise. This is in sharp comparison to the publishing patterns exhibited in Latin America where the academic sector is the most prominent one.     

微商车的垂直振动不舒适度模型和实验研究

微商车因为突出的装载能力在国内中小城市和乡镇地区非常受欢迎。随着人们对车辆乘坐舒适性要求的提高,有必要研究微商车行驶时车内振动产生的不舒适度,建立振动不舒适度的预测模型,有助于更好地对车辆的振动控制进行指导。针对中小城市和乡镇地区较为复杂的路况,研究了微商车在沥青、水泥、砂石和颠簸四种路面行驶时车内垂直振动加速度和人体不舒适度值之间的关系。每个路况下选取6个振动样本,振动加速度采用Wb计权,范围为0.531-2.991m/s2,总共24个振动样本。30位评价人员采用绝对幅值评价法给出每个振动样本作用下的不舒适值。采用线性回归方法分析加速度和振动不舒适度的关系,建立了微商车在不同路况下行驶时车内垂直振动产生的不舒适度预测模型。     

Switchgrass (Panicum virgatumL.) as a reinforcing fibre in polypropylene composites

In this study the switchgrass (Panicum virgatumL.), a biomass crop being developed in North America and Europe, was tested as a stiffening and reinforcing agent in polypropylene (PP) composites with and without maleic anhydride grafted PP (MAPP) as a compatibiliser and to evaluate the effect of pulping and different sources of switchgrass on composite characteristics. The refiner pulping yield for two switchgrass varieties was estimated between 70–80%. The addition of 30% (by weight) switchgrass pulp resulted in an increase of the flexural modulus by a factor of about 2.5 compared to pure polypropylene. Which was only slightly lower than values found for jute and flax. The flexural strength of PP composites reinforced with pulped switchgrass and MAPP was almost doubled compared to pure PP and approached values found for jute and flax. The compatibilising effect of MAPP has been visualised by micrographs. The good mechanical properties are achieved despite the severe fibre length reduction as a result of thermoplastic compounding which is shown by fibre length analysis. The impact strength of switchgrass/PP composites was much lower than for pure PP. The use of different switchgrass varieties and harvesting time had a minor to no effect on the mechanical performance of the respective composites. The chemical composition of different varieties was fairly constant. The low price and the relatively good mechanical characteristics should make switchgrass an attractive fibre for filling and stiffening in thermoplastic composites. Further improvement of composite mechanical properties should be possible.     

Determination of the adsorption capacity of activated carbon made from coffee grounds by chemical activation with ZnCl2 and H3PO4

In order to evaluate the adsorptive capacities of granular activated carbon produced from coffee grounds by chemical activation, the adsorption of different phenols and acid and basic dyes, has been carried out. The comparison with a commercial activated carbon has been made. Adsorption isotherms of phenols and dyes (acid and basic) onto produced and commercial granular activated carbons were experimentally determined by batch tests. Both Freundlich and Langmuir models are well suited to fit the adsorption isotherm data. As a result, the coffee grounds based activated carbon may be promising for phenol and dye removal from aqueous streams.     

Modelling the perennial energy crop market: the role of spatial diffusion

Biomass produced from energy crops, such as Miscanthus and short rotation coppice is expected to contribute to renewable energy targets, but the slower than anticipated development of the UK market implies the need for greater understanding of the factors that govern adoption. Here, we apply an agent-based model of the UK perennial energy crop market, including the contingent interaction of supply and demand, to understand the spatial and temporal dynamics of energy crop adoption. Results indicate that perennial energy crop supply will be between six and nine times lower than previously published, because of time lags in adoption arising from a spatial diffusion process. The model simulates time lags of at least 20 years, which is supported empirically by the analogue of oilseed rape adoption in the UK from the 1970s. This implies the need to account for time lags arising from spatial diffusion in evaluating land-use change, climate change (mitigation or adaptation) or the adoption of novel technologies.     

智能空调控制农业温室生产温湿度的现状分析与设计构想

智能空调应用于农业温室作物生产中，能提供最适宜的生长环境，相比其他设计应用更易于控制，操作简便。基于此设想。我们将对现阶段空调对作物生产所需环境——尤其温湿度联合控制的不足作分析与探究，使其更具应用价值，实现空调智能化调节。     

Suppressive effect of magnesium oxide materials on cadmium accumulation in winter wheat grain cultivated in a cadmium-contaminated paddy field under annual rice–wheat rotational cultivation

The effectiveness of two kinds of magnesium oxide (MgO) materials, commercial MgO (2250 kg ha⁻¹) and a material derived from MgO and magnesium silicate minerals named ‘MgO-SH-A’ (2250 and 4500 kg ha⁻¹1), in suppression of uptake and accumulation of cadmium (Cd) into grain of winter wheat (Triticum aestivum L. cv. Ayahikari) was examined in a Cd-contaminated alluvial paddy field under annual rice–wheat rotational system. The MgO materials were mixed into the plough-layer soil only once prior to the preceding rice cultivation. Cadmium concentration in wheat grain produced from the non-amendment control exceeded the maximum limit of Cd in wheat grain adopted by FAO/WHO (0.2 mg kg⁻¹). All of the treatments with the MgO materials significantly lowered plant available Cd fraction in the plough-layer soil. However, only the treatment with the commercial MgO at 2250 kg ha⁻¹ produced wheat grain whose Cd concentration was not only significantly lower than that from the control but also less than 0.2 mg kg⁻¹. It is suggested that the significant suppressive effect of the commercial MgO on Cd accumulation in wheat grain would be mainly attributed to its high soil neutralizing capacity as compared to that of MgO-SH-A.     

Agriculture and food systems in sub-Saharan Africa in a 4°C+ world

Agricultural development in sub-Saharan Africa faces daunting challenges, which climate change and increasing climate variability will compound in vulnerable areas. The impacts of a changing climate on agricultural production in a world that warms by 4°C or more are likely to be severe in places. The livelihoods of many croppers and livestock keepers in Africa are associated with diversity of options. The changes in crop and livestock production that are likely to result in a 4°C+ world will diminish the options available to most smallholders. In such a world, current crop and livestock varieties and agricultural practices will often be inadequate, and food security will be more difficult to achieve because of commodity price increases and local production shortfalls. While adaptation strategies exist, considerable institutional and policy support will be needed to implement them successfully on the scale required. Even in the 2°C+ world that appears inevitable, planning for and implementing successful adaptation strategies are critical if agricultural growth in the region is to occur, food security be achieved and household livelihoods be enhanced. As part of this effort, better understanding of the critical thresholds in global and African food systems requires urgent research.     

商品混凝土在生产和浇筑过程中常见问题的处理方法

在商品混凝土的生产、交付和凝结硬化过程中，常常会遇到混凝土坍落度过小或过大、和易性差、缓凝、裂缝、强度不足、亏方等问题，有些问题处理不当，将会造成较大的经济损失，并且降低了企业的信誉。为了避免上述问题的发生，提高商品混凝土企业的信誉，特编写了此文作为借鉴或参考。     

Influence of architecture on the Raman spectra of acid-treated carbon nanostructures

Raman spectroscopy was used to characterise 11 varieties of carbon nanostructures (CNSs) consisting on seven varieties of commercial multi-walled carbon nanotubes, two types of carbon nanofibres and two types of lab-synthesised single-walled carbon nanotubes. The Raman spectra of these CNSs provided information on the structural ordering of the as-received (or as-synthesised) material. Additionally, the CNSs were chemically treated by two mixtures of nitric and sulphuric acids at markedly different concentrations and then characterised by Raman spectroscopy. The features of the G and D Raman bands of the CNSs were used to assess structural modifications and generation of defects induced by the acid treatments. Changes in the Raman spectra before and after acidic treatment depend strongly on the initial intensity ratio of the G to D bands and the architecture (number of layers or diameter) of the CNSs.     

Investigation of fatigue cracks in aluminium alloys 2024 and 6013 in laboratory air and corrosive environment

Fatigue cracks have been generated in the commercial aluminium alloys AA2024 and AA6013 and analysed with a positron microprobe. This instrument provides laterally resolved positron annihilation measurements, which are sensitive to lattice defects like vacancies and dislocations. These commercial alloys have undergone a solution heat treatment and quenching prior to fatigue testing. Subsequently, they have been aged at room temperature and 190°C for AA2024 and AA6013, respectively. We performed the fatigue crack generation both in air and under the influence of a chemically aggressive environment (artificial seawater). Due to the corrosive environment hydrogen is probably produced at the fresh fractured surface in the vicinity of the crack tip. We discuss the possible implications of in-diffused hydrogen on the produced lattice defects, especially when there is a delayed migration of vacancies in the lattice, due to a reduced mobility.     

Sustainable development of China's commercial vehicles

Automobiles are the major contributor to fuel consumption and emission of pollutants.The growth of the vehicle fleet has also placed enormous pressure on China's energy supply and environment.Thus sustainable development of the Chinese automotive industry must pay significant attention to fuel-saving and emission-reduction of vehicles.Although commercial vehicles make up only about 20%of the entire automobile fleet,their contribution to energy-consumption and emission of pollutants is significant.Thus,priority should be given to fuel-saving and emission-reduction of commercial vehicles.As a result of concerted efforts by Chinese government,industry and enterprises,great progress has been made in technologies concerning new-energy,intelligent and lightweight automobiles.However,compared with developed countries,the level of lightweighting of commercial vehicles produced in China remains comparably low.This means that great potential for development of lightweight commercial vehicles in China exists and it will be an efficient path towards fuel-saving and emission-reduction.