Risk-appropriate regulations for gene-editing technologies

This paper explores the scope for the newly emerging technologies, based on gene editing (GE) contributing to addressing the global challenges that we face. These challenges relate to food security, climate change and biodiversity depletion. In particular, it examines the science and evidence behind the most appropriate forms of agricultural production to meet these challenges, the targets set in the Global Biodiversity Framework (GBF) agreed to at the end of 2022 and the possible role of GE technologies in contributing to meeting these targets. It then examines the most risk-appropriate regulatory environment required to best facilitate the adoption of GE technology, drawing on the experiences of the impact of regulatory systems for other innovations used in agricultural and food production systems such as genetically modified organisms (GMOs).

Genetically Modified (GM) Crop Use 1996-2020: Impacts on Carbon Emissions

This paper assesses how the use of genetically modified seed (GM) crop seed technology has impacted on greenhouse gas emissions at a global level. The main technologies of relevance are crops modified to be tolerant to specific herbicides so as to facilitate improved weed control and crops resistant to a range of crop insect pests that otherwise damage crops or typically require the application of insecticides to control them. Over the 24 year period examined to 2020, the widespread use of GM insect resistant and herbicide tolerant seed technology has led to important cuts in on-farm fuel use and facilitated farmers moving from plow-based systems to reduced and no tillage systems that they have continued to operate for a number of years. This has led to a significant reduction in the release of greenhouse gas emissions from the GM cropping area, which in 2020 was equal to a saving of 23,631 million kg of carbon dioxide, equivalent to taking 15.6 million cars off the road for a year (equal to 49% of registered cars in the UK).

Genetically Modified (GM) Crop Use 1996-2020: Environmental Impacts Associated with Pesticide Use CHANGE

This paper assesses the environmental impacts associated with changes in pesticide use with GM crops at a global level. The main technologies impacting on pesticide use have been crops modified to be tolerant to specific herbicides so as to facilitate improved weed control and crops resistant to a range of crop insect pests that otherwise damage crops or typically require the application of insecticides to control them. Over the 24 year period examined to 2020, the widespread use of GM insect resistant and herbicide tolerant seed technology has reduced pesticide application by 748.6 million kg (-7.2%) of active ingredient and, as a result, decreased the environmental impact associated with insecticide and herbicide use on these crops (as measured by the indicator, the Environmental Impact Quotient (EIQ)) by a larger 17.3% between 1996 and 2020. The technology that has delivered the largest change in pesticide use has been insect resistant cotton, where a 339 million kg of active ingredient saving has occurred and the associated environmental impact (as measured by the EIQ indicator) has fallen by about a third.

The impact of using genetically modified (GM) corn/maize in Vietnam: Results of the first farm-level survey

This study assessed the farm-level economic and environmental impacts from the use of genetically modified (GM) corn in Vietnam (resistant to Lepidopteran pests of corn and tolerant to the herbicide glyphosate). It was largely based on a farmer survey conducted in 2018-19. The GM varieties out-performed conventional varieties in terms of yield by +30.4% (+15.2% if the yield comparison is with only the nearest performing equivalent conventional varieties) and reduced the cost of production by between US $26.47 per ha and US $31.30 per ha. For every extra US $1 spent on GM seed relative to conventional seed, farmers gained between an additional US $6.84 and US $12.55 in extra income. The GM maize technology also reduced insecticide and herbicide use. The average amount of herbicide active ingredient applied to the GM crop area was 26% lower (1.66 kg per ha) than the average value for the conventional corn area (2.26 kg/ai per ha) and in terms of the associated environmental impact of the herbicide use, as measured by the Environmental Impact Quotient (EIQ) indicator, it was lower by 36% than the average value applicable to the conventional corn area. Insecticides were used on a significantly lower GM crop area and, when used, in smaller amounts. The average amount of insecticide applied to the GM corn crop was significantly lower by 78% (0.08 kg/ai per ha) than the average value for the conventional corn area (0.36 kg/ai per ha) and in terms of the associated environmental impact of the insecticide use, as measured by the EIQ indicator, it was also lower by 77% than the average value for conventional corn (14.06 per ha).

Environmental impacts of genetically modified (GM) crop use 1996-2018: impacts on pesticide use and carbon emissions

This paper updates previous assessments of the environmental impacts associated with using crop biotechnology (specifically genetically modified crops) in global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops since their first widespread commercial use 22 years ago. The adoption of GM insect resistant and herbicide tolerant technology has reduced pesticide spraying by 775.4 million kg (8.3%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator, the Environmental Impact Quotient (EIQ)) by 18.5%. The technology has also facilitated important cuts in fuel use and tillage changes, resulting in a significant reduction in the release of greenhouse gas emissions from the GM cropping area. In 2018, this was equivalent to removing 15.27 million cars from the roads.

GM crop technology use 1996-2018: farm income and production impacts

This paper estimates the global value of using genetically modified (GM) crop technology in agriculture at the farm level. It follows and updates earlier studies which examined impacts on yields, key variable costs of production, direct farm (gross) income, and impacts on the production base of the four main crops of soybeans, corn, cotton, and canola. This updated analysis shows that there continues to be very significant net economic benefits at the farm level amounting to $18.9 billion in 2018 and $225.1 billion for the period 1996-2018 (in nominal terms). These gains have been divided 52% to farmers in developing countries and 48% to farmers in developed countries. Seventy-two per cent of the gains have derived from yield and production gains with the remaining 28% coming from cost savings. The technology has also made important contributions to increasing global production levels of the four main crops, having, for example, added 278 million tonnes and 498 million tonnes, respectively, to the global production of soybeans and maize since the introduction of the technology in the mid-1990 s. In terms of investment, for each extra dollar invested in GM crop seeds (relative to the cost of conventional seed), farmers gained an average US $3.75 in extra income. In developing countries, the average return was $4.41 for each extra dollar invested in GM crop seed and in developed countries the average return was $3.24.

Impact of Bt Brinjal Cultivation in the Market Value Chain in Five Districts of Bangladesh

Eggplant (brinjal) is a popular vegetable that provides an important source of income for small, resource-poor Bangladeshi farmers. The biggest constraint to brinjal production is the eggplant fruit and shoot borer (EFSB). This study was conducted in 2019 in five districts in Bangladesh and examined the impacts of using genetically engineered, insect-resistant brinjal (Bt brinjal) on its value and marketing. Based on a survey of Bt and non-Bt farmers, results indicate that Bt brinjal provided an average of 19.6% higher yield and 21.7% higher revenue compared to non-Bt varieties. On a per tonne basis, the revenue benefit of using Bt brinjal was 1.7%, reflecting different levels of acceptability among trade buyers and consumers. Some were prepared to pay higher prices for Bt brinjal compared to non-Bt brinjal because the fruit was less damaged, while others paid a price discount because the Bt brinjal was not available in preferred local varieties. Labor use, expressed in 8-h days, for harvesting, grading, and packaging of Bt brinjal was 14% higher for Bt brinjal, reflecting the increased yields of Bt brinjal. 83.1% of Bt brinjal growers were satisfied with the yields obtained, and 80.6% were satisfied with the quality of fruit. This contrasts with non-Bt brinjal growers where 58.7% were satisfied with their yields and 28% indicated that a large portion of their fruit was infested, not a concern for Bt brinjal. Three-quarters of Bt brinjal growers planned to plant Bt brinjal next season because of the apparent benefits achieved of higher yields, revenue and fruit quality. Many also highlighted the benefits of reduced insecticides. Of the non-Bt growers, 39.6% had not heard of Bt brinjal. However, after hearing more about the impact of the technology, 71.4% of them indicated they planned to grow Bt brinjal next season. These findings suggest there are significant benefits of Bt brinjal and highlight the importance of making the technology available in more varieties that are suitable to local conditions and consumer preferences. Additional studies are warranted to corroborate these findings and explore in more detail the factors influencing decisions made by farmers and consumers regarding Bt brinjal.

Genetically modified (GM) crop use in Colombia: farm level economic and environmental contributions

This study assesses the economic and environmental impacts that have arisen from the adoption and use of genetically modified (GM) cotton and maize in Colombia in the fifteen years since GM cotton was first planted in Colombia in 2003. A total of 1.07 million hectares have been planted to cotton and maize containing GM traits since 2003, with farmers benefiting from an increase in income of US $301.7 million. For every extra US $1 spent on this seed relative to conventional seed, farmers have gained an additional US $3.09 in extra income from growing GM cotton and an extra US $5.25 in extra income from growing GM maize. These income gains have mostly arisen from higher yields (+30.2% from using stacked (herbicide tolerant and insect resistant cotton and +17.4% from using stacked maize). The cotton and maize seed technology have reduced insecticide and herbicide spraying by 779,400 kg of active ingredient (−19%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator, the Environmental Impact Quotient (EIQ)) by 26%. The technology has also facilitated cuts in fuel use, resulting in a reduction in the release of greenhouse gas emissions from the GM cotton and maize cropping area and contributed to saving scarce land resources.

Identity Preservation of Genetically Modified Organisms in the Food Chain: Requirements, Methods, and Costs

The use of the technology of genetic modification (GM) in European agriculture and the food supply chain is currently controversial. Because of strong anti-GM technology sentiments, the use of ingredients derived from plants containing GM have largely been eliminated from foods manufactured for direct human consumption by the food supply chain in much of the European Union (EU). During the past year, the attention of those opposed to the technology has turned to the use of GM ingredients in livestock production systems by incorporation of GM soy and maize in animal feed. A discussion is presented of the key issues relating to this subject, focusing on how supplies of GM or non-GM products are segregated or how their identities are preserved. The discussion is centered on GM maize and soybeans into which agronomic traits, such as herbicide tolerance and/or insect resistance, have been incorporated. These are currently the only crops into which some varieties containing GM have been approved for use in the EU.

Twenty-one years of using insect resistant (GM) maize in Spain and Portugal: farm-level economic and environmental contributions

This study assesses the economic and environmental impacts that have arisen from the adoption and use of genetically modified (GM) insect resistant (IR) maize in Spain and Portugal in the 21 years since first planted in Spain in 1998. A total of 1.65 million hectares have been planted to maize containing these traits since 1998, with farmers benefiting from an increase in income of €285.4 million. For every extra €1 spent on this seed relative to conventional seed, farmers have gained an additional €4.95 in extra income. These income gains have mostly arisen from higher yields (+11.5% across the two countries using the technology). The seed technology has reduced insecticide spraying by 678,000 kg of active ingredient (−37%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator, the Environmental Impact Quotient (EIQ)) by 21%. The technology has also facilitated cuts in fuel use, resulting in a reduction in the release of greenhouse gas emissions from the GM IR maize cropping area and contributed to saving scarce water resources.

Environmental impacts of genetically modified (GM) crop use 1996-2016: Impacts on pesticide use and carbon emissions

This paper updates previous assessments of the environmental impacts associated with using crop biotechnology in global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops since their first widespread commercial use over 20 years ago. The adoption of GM insect resistant and herbicide tolerant technology has reduced pesticide spraying by 671.4 million kg (8.2%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator, the Environmental Impact Quotient (EIQ)) by 18.4%. The technology has also facilitated important cuts in fuel use and tillage changes, resulting in a significant reduction in the release of greenhouse gas emissions from the GM cropping area. In 2016, this was equivalent to removing 16.7 million cars from the roads.

The farm level economic and environmental contribution of Intacta soybeans in South America: the first five years

This study assesses the economic and environmental impacts that have arisen from the adoption and use of genetically modified (GM) herbicide tolerant (HT) and insect resistant (IR) soybeans in South America in the five years since first planted in 2013/14. A total of 73.6 million hectares have been planted to soybeans containing these traits since 2013/14, with farmers benefiting from an increase in income of $7.64 billion. For every extra $1 spent on this seed relative to conventional seed, farmers have gained an additional $3.88 in extra income. These income gains have arisen from a combination of higher yields (+ 9.2% across the four countries using the technology) and lower costs of weed and pest control. The seed technology has reduced pesticide spraying by 10.44 million kg (-15.1%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator, the Environmental Impact Quotient (EIQ)) by 30.6%. The technology has also facilitated important cuts in fuel use and tillage changes, resulting in a significant reduction in the release of greenhouse gas emissions from the GM cropping area. In 2017/18, this was equivalent to removing 3.3 million cars from the roads.

Farm income and production impacts of using GM crop technology 1996-2016

This paper estimates the value of using genetically modified (GM) crop technology in agriculture at the farm level. It follows and updates earlier annual studies which examined impacts on yields, key variable costs of production, direct farm (gross) income and impacts on the production base of the four main crops of soybeans, corn, cotton and canola. The commercialisation of GM crops has occurred at a rapid rate since the mid 1990s, with important changes in both the overall level of adoption and impact occurring in 2016. This annual updated analysis shows that there continues to be very significant net economic benefits at the farm level amounting to $18.2 billion in 2016 and $186.1 billion for the period 1996-2016 (in nominal terms). These gains have been divided 48% to farmers in developed countries and 52% to farmers in developing countries. About 65% of the gains have derived from yield and production gains with the remaining 35% coming from cost savings. The technology has also made important contributions to increasing global production levels of the four main crops, having, for example, added 213 million tonnes and 405 million tonnes respectively, to the global production of soybeans and maize since the introduction of the technology in the mid 1990s.

The contribution of glyphosate to agriculture and potential impact of restrictions on use at the global level

This study assesses the potential economic and environmental impacts that would arise if restrictions on glyphosate use resulted in the world no longer planting genetically modified herbicide tolerant (GM HT) crops. 'First round' impacts are the loss of farm level and aggregate impacts associated with the widespread use of GM HT crops (tolerant to glyphosate). There would be an annual loss of global farm income gains of $6.76 billion and lower levels of global soybean, corn and canola production equal to 18.6 million tonnes, 3.1 million tonnes and 1.44 million tonnes respectively. There would be an annual environmental loss associated with a net increase in the use of herbicides of 8.2 million kg of herbicide active ingredient (+1.7%), and a larger net negative environmental impact, as measured by the environmental impact quotient (EIQ 11 Kovach J et al1. ) indicator of a 12.4%. Also, there would be additional carbon emissions arising from increased fuel usage and decreased soil carbon sequestration, equal to the equivalent of adding 11.77 million cars to the roads. Global welfare impacts based on these farm level impacts (identified through use of the Computable General Equilibrium (CGE) model GTAP-BIO) point to global production of soybeans and rapeseed falling by 3.7% and 0.7% respectively, partially offset by increases in other oilseeds (notably palm oil).  World prices of all grains, oilseeds and sugar are expected to rise, especially soybeans (+5.4%) and rapeseed (+2%). The welfare impacts are mostly negative, with global welfare falling by $7,408 million per year. Land use changes will arise, with an additional cropping area of 762,000 ha, of which 53% derives from new land brought into cropping agriculture, including 167,000 of deforestation. These land use changes are likely to induce the generation of an additional 234,000 million kg of carbon dioxide emissions.

Farm income and production impacts of using GM crop technology 1996-2015

This paper provides an assessment of the value of using genetically modified (GM) crop technology in agriculture at the farm level. It follows and updates earlier annual studies which examined impacts on yields, key variable costs of production, direct farm (gross) income and impacts on the production base of the 4 main crops of soybeans, corn, cotton and canola. The commercialisation of GM crops has occurred at a rapid rate since the mid 1990s, with important changes in both the overall level of adoption and impact occurring in 2015. This annual updated analysis shows that there continues to be very significant net economic benefits at the farm level amounting to $15.4 billion in 2015 and $167.8 billion for the 20 year period 1996-2015 (in nominal terms). These gains have been divided 49% to farmers in developed countries and 51% to farmers in developing countries. About 72% of the gains have derived from yield and production gains with the remaining 28% coming from cost savings. The technology has also made important contributions to increasing global production levels of the 4 main crops, having, for example, added 180 million tonnes and 358 million tonnes respectively, to the global production of soybeans and maize since the introduction of the technology in the mid 1990s.

Environmental impacts of genetically modified (GM) crop use 1996-2015: Impacts on pesticide use and carbon emissions

This paper updates previous assessments of important environmental impacts associated with using crop biotechnology in global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops since their first widespread commercial use in the mid-1990s. The adoption of GM insect resistant and herbicide tolerant technology has reduced pesticide spraying by 618.7 million kg (-8.1%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator, the Environmental Impact Quotient (EIQ)) by18.6%. The technology has also facilitated important cuts in fuel use and tillage changes, resulting in a significant reduction in the release of greenhouse gas emissions from the GM cropping area. In 2015, this was equivalent to removing 11.9 million cars from the roads.

Environmental impacts of genetically modified (GM) crop use 1996-2014: Impacts on pesticide use and carbon emissions

This paper updates previous assessments of important environmental impacts associated with using crop biotechnology in global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops since their first widespread commercial use in the mid 1990s. The adoption of GM insect resistant and herbicide tolerant technology has reduced pesticide spraying by 581.4 million kg (-8.2%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator, the Environmental Impact Quotient [EIQ]) by18.5%. The technology has also facilitated important cuts in fuel use and tillage changes, resulting in a significant reduction in the release of greenhouse gas emissions from the GM cropping area. In 2014, this was equivalent to removing nearly 10 million cars from the roads.

Global income and production impacts of using GM crop technology 1996-2014

This paper provides an economic assessment of the value of using genetically modified (GM) crop technology in agriculture at the farm level. It follows and updates earlier annual studies which examined economic impacts on yields, key costs of production, direct farm income and effects, and impacts on the production base of the 4 main crops of soybeans, corn, cotton and canola. The commercialisation of GM crops has continued to occur at a rapid rate since the mid 1990s, with important changes in both the overall level of adoption and impact occurring in 2014. This annual updated analysis shows that there continues to be very significant net economic benefits at the farm level amounting to $17.7 billion in 2014 and $150.3 billion for the 19-year period 1996-2014 (in nominal terms). These economic gains have been divided roughly 50% each to farmers in developed and developing countries. About 65% of the gains have derived from yield and production gains with the remaining 35% coming from cost savings. The technology has also made important contributions to increasing global production levels of the 4 main crops, having, for example, added 158 million tonnes and 322 million tonnes respectively, to the global production of soybeans and maize since the introduction of the technology in the mid 1990s.

Weed control changes and genetically modified herbicide tolerant crops in the USA 1996-2012

Crops that have been genetically modified (GM) to be tolerant to herbicides have been widely grown in the USA since 1996. The rapid and widespread adoption of this technology reflects the important economic and environmental benefits that farmers have derived from its use (equal to $21.7 billion additional farm income and a 225 million kg reduction in herbicide active ingredient use 1996–2012). During this time, weed control practices in these crops relative to the ‘conventional alternative’ have evolved to reflect experience of using the technology, the challenges that have arisen and the increasing focus in recent years on developing sustainable production systems. This paper examines the evidence on the changing nature of herbicides used with these crops and in particular how farmers addressed the challenge of weed resistance. The evidence shows that use of the technology has resulted in a net reduction in both the amount of herbicide used and the associated environmental impact, as measured by the EIQ indicator when compared to what can reasonably be expected if the area planted to GM HT crops reverted to conventional production methods. It also facilitated many farmers being able to derive the economic and environmental benefits associated with switching from a plough-based to a no tillage or conservation tillage production system. In terms of herbicide use, the technology has also contributed to a change the profile of herbicides used. A broad range of, mostly selective herbicides has been replaced by one or 2 broad-spectrum herbicides (mostly glyphosate) used in conjunction with one or 2 other (complementary) herbicides. Since the mid-2000s, the average amount of herbicide applied and the associated environmental load, as measured by the EIQ indicator, have increased on both GM HT and conventional crops. A primary reason for these changes has been increasing incidence of weed species developing populations resistant to herbicides and increased awareness of the consequences of relying on a single or very limited number of herbicides for weed control. As a result, growers of GM HT crops have become much more proactive and diversified in their weed management programs in line with weed scientist recommendations and now include other herbicides (with different and complementary modes of action) in combination with glyphosate, even where instances of weed resistance to glyphosate have not been found. The willingness to proactively diversity weed management systems in the GM HT crops is also influenced by a desire to maintain effective weed control and hence continue to enjoy the benefits of no tillage and conservation tillage. Nevertheless, despite the increase in herbicide use in recent years, the use of GM HT technology continues to deliver significant economic and environmental gains to US farmers.

A ‘Genetically Engineered’ Label: Way More Expensive Than You Think

Pseudo-controversy continues to rage over whether foods from plants and animals genetically engineered with the newest molecular techniques should have to be labeled as such. The battles, fought in the media, state legislatures, referendum issues, and in federal courts, have been largely fomented and funded by the organic agriculture and food industries. All but one of the proposals to require labeling in the United States have failed, and that exception is being challenged in a federal court . In spite of these failures and the fact that mandatory labeling fails every test –scientific, economic, legal and common-sense–the true believers soldier on.

Environmental impacts of genetically modified (GM) crop use 1996-2013: Impacts on pesticide use and carbon emissions

This paper updates previous assessments of how crop biotechnology has changed the environmental impact of global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops since their first widespread commercial use in the mid 1990s. The adoption of GM insect resistant and herbicide tolerant technology has reduced pesticide spraying by 553 million kg (-8.6%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator the Environmental Impact Quotient (EIQ)) by 19.1%. The technology has also facilitated important cuts in fuel use and tillage changes, resulting in a significant reduction in the release of greenhouse gas emissions from the GM cropping area. In 2013, this was equivalent to removing 12.4 million cars from the roads.

Global income and production impacts of using GM crop technology 1996-2013

This paper provides an economic assessment of the value of using genetically modified (GM) crop technology in agriculture at the farm level. It follows and updates earlier annual studies which examined economic impacts on yields, key costs of production, direct farm income and effects, and impacts on the production base of the 4 main crops of soybeans, corn, cotton and canola. The commercialisation of GM crops has continued to occur at a rapid rate since the mid 1990s, with important changes in both the overall level of adoption and impact occurring in 2013. This annual updated analysis shows that there continues to be very significant net economic benefits at the farm level amounting to $20.5 billion in 2013 and $133.4 billion for the 18 years period (in nominal terms). These economic gains have been divided roughly 50% each to farmers in developed and developing countries. About 70% of the gains have derived from yield and production gains with the remaining 30% coming from cost savings. The technology have also made important contributions to increasing global production levels of the 4 main crops, having added 138 million tonnes and 273 million tonnes respectively, to the global production of soybeans and maize since the introduction of the technology in the mid 1990s.

Key global environmental impacts of genetically modified (GM) crop use 1996-2012

Against the background of increasing awareness and appreciation of issues such as global warming and the impact of mankind's activities such as agriculture on the global environment, this paper updates previous assessments of some key environmental impacts that crop biotechnology has had on global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops. The adoption of the technology has reduced pesticide spraying by 503 million kg (-8.8%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator the Environmental Impact Quotient [EIQ]) by 18.7%. The technology has also facilitated a significant reduction in the release of greenhouse gas emissions from this cropping area, which, in 2012, was equivalent to removing 11.88 million cars from the roads.

Economic impact of GM crops: the global income and production effects 1996-2012

A key part of any assessment of the global value of crop biotechnology in agriculture is an examination of its economic impact at the farm level. This paper follows earlier annual studies which examined economic impacts on yields, key costs of production, direct farm income and effects, and impacts on the production base of the four main crops of soybeans, corn, cotton and canola. The commercialization of genetically modified (GM) crops has continued to occur at a rapid rate, with important changes in both the overall level of adoption and impact occurring in 2012. This annual updated analysis shows that there have been very significant net economic benefits at the farm level amounting to $18.8 billion in 2012 and $116.6 billion for the 17-year period (in nominal terms). These economic gains have been divided roughly 50% each to farmers in developed and developing countries. GM technology have also made important contributions to increasing global production levels of the four main crops, having added 122 million tonnes and 230 million tonnes respectively, to the global production of soybeans and maize since the introduction of the technology in the mid-1990s.

Key environmental impacts of global genetically modified (GM) crop use 1996-2011

Given the increasing awareness and appreciation of issues such as global warming and the impact of mankind's activities such as agriculture on the global environment, this paper updates previous assessments of the environmental impact of an important and relatively new technology, crop biotechnology has had on global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops. The adoption of the technology has reduced pesticide spraying by 474 million kg (-8.9%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops [as measured by the indicator the Environmental Impact Quotient (EIQ)] by 18.1%. The technology has also facilitated a significant reduction in the release of greenhouse gas emissions from this cropping area, which, in 2011, was equivalent to removing 10.22 million cars from the roads.

The global income and production effects of genetically modified (GM) crops 1996-2011

A key part of any assessment of the global value of crop biotechnology in agriculture is an examination of its economic impact at the farm level. This paper follows earlier annual studies which examined economic impacts on yields, key costs of production, direct farm income and effects and impacts on the production base of the four main crops of soybeans, corn, cotton and canola. The commercialization of genetically modified (GM) crops has continued to occur at a rapid rate, with important changes in both the overall level of adoption and impact occurring in 2011. This annual updated analysis shows that there have been very significant net economic benefits at the farm level amounting to $19.8 billion in 2011 and $98.2 billion for the 16 year period (in nominal terms). The majority (51.2%) of these gains went to farmers in developing countries. GM technology have also made important contributions to increasing global production levels of the four main crops, having added 110 million tonnes and 195 million tonnes respectively, to the global production of soybeans and maize since the introduction of the technology in the mid-1990s.

Sleep-related breathing disorders in the Shy-Drager syndrome. Observations on investigation and management

We report on 18 patients with the Shy-Drager syndrome who were referred for assessment of a sleep-related breathing disorder. The main symptoms of snoring, apnoea, stridor and daytime hypersomnolence were detailed and vocal cord movement graded by laryngoscopy as normal, mild weakness of abduction or near paralysis of vocal cord movement Sleep studies involving oximetry and observations were performed. Obstructive and central apnoeas were detected in six patients. Many patients with near paralysis of vocal cord abduction had normal sleep studies. Successful management strategies of obstructive cases included CPAP, nasal surgery and tracheostomy or arytenoidectomy alone or in combination. Sleep-related breathing disorders in the Shy-Drager syndrome may involve significant nocturnal desaturation; investigation with suitable medical or surgical treatment should be employed in these patients.

The income and production effects of biotech crops globally 1996-2010

A critical feature in evaluating the global value of crop biotechnology in agriculture must include an assessment of its economic impact at the farm level. This paper follows earlier studies which examined economic impacts on yields, key costs of production, direct farm income, indirect (non-pecuniary) farm level income effects and impacts on the production base of the four main crops of soybeans, corn, cotton and canola. The commercialization of biotech crops is continuing to proceed rapidly, with significant changes in the overall level of adoption and impact taking place in 2010. This updated analysis shows that there have been substantial net economic benefits at the farm level amounting to $14 billion in 2010 and $78.4 billion for the 15-year period (in nominal terms). The non-pecuniary benefits associated with the use of the technology have also had a positive impact on adoption (in the US accounting for the equivalent of 22% of the total US direct farm income benefit). Biotech crops are, moreover, making important contributions to increasing global production levels of the four main crops. They have, for example, now added 97.5 million tons and 159 million tons respectively, to the global production of soybeans and corn since the introduction of the technology in the mid-1990s.

Global impact of biotech crops: environmental effects, 1996-2010

This paper updates the assessment of the impact commercialized agricultural biotechnology is having on global agriculture, from some important environmental perspectives. It focuses on the impact of changes in pesticide use and greenhouse gas emissions arising from the use of biotech crops. The technology has reduced pesticide spraying by 443 million kg (-9.1%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops [as measured by the indicator the Environmental Impact Quotient (EIQ)] by 17.9%. The technology has also significantly reduced the release of greenhouse gas emissions from this cropping area, which, in 2010, was equivalent to removing 8.6 million cars from the roads.

Does an encouraging letter encourage attendance at psychiatric out-patient clinics? The Leeds PROMPTS randomized study

BACKGROUND

The aim was to reduce non-attendance for first-time consultations at psychiatric out-patient clinics.

METHOD

The study was a pragmatic randomized controlled trial; the setting was seven inner-city UK out-patient clinics in Leeds. The participants were 764 subjects of working age with an appointment to attend a psychiatric out-patient clinic for the first time. The intervention was an 'orientation statement' letter delivered 24-48 h before the first appointment compared with standard care. The primary outcome measure was attendance at the first appointment; secondary outcomes included hospitalization, transfer of care, continuing attendance, discharge, presentation at accident and emergency and death by 1 year.

RESULTS

Follow-up was for 763 out of 764 subjects (>99%) for primary and for 755 out of 764 subjects (98.8%) of secondary outcome data. The orientation statement significantly reduced the numbers of people failing to attend [79 out of 388 v. 101 out of 376 subjects, relative risk 0.76, 95% confidence interval (CI) 0.59-0.98, number needed to treat 16, 95% CI 10-187].

CONCLUSIONS

Prompting people to go to psychiatric out-patient clinics for the first time encourages them to attend. Pragmatic trials within a busy working environment are possible and informative.

Pharmacological treatments for psychosis-related polydipsia

BACKGROUND

Polydipsia is the intake of more than three litres of fluids per day. Primary polydipsia occurs when excessive drinking cannot be explained by an identified medical condition, and is not secondary to polyuria. The prevalence of this problem in psychiatric inpatients has been estimated at between 6 and 17%. It can hinder standard care and be a highly disabling, even life-threatening condition.

OBJECTIVES

To review the effect of pharmacological interventions for the treatment of psychosis-related polydipsia.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group's Register (January 2002 and February 2005) which is compiled by up-to-date methodical searches of BIOSIS, The Cochrane Library, CINAHL, Dissertation abstracts, EMBASE, LILACS, MEDLINE, PSYNDEX, PsycINFO, RUSSMED and Sociofile and is supplemented with hand searching of relevant journals and numerous conference proceedings. References of all identified studies were also searched for further trials.

SELECTION CRITERIA

We included all randomised controlled trials involving people with a psychotic illness and secondary polydipsia, which evaluated drug treatments, and measured clinically meaningful outcomes.

DATA COLLECTION AND ANALYSIS

Working independently, we inspected citations, ordered papers, and then re-inspected and quality assessed the studies and extracted data. For homogeneous dichotomous data, we calculated the relative risk (RR), 95% confidence interval (CI), and, where appropriate, the number needed to treat (NNT) and the number needed to harm (NNH), on an intention-to-treat basis. We assumed that people who left the study early or who were lost to follow-up had no improvement. We calculated weighted mean differences (WMD) for continuous data. We excluded data if loss to follow-up was greater than 50%.

MAIN RESULTS

We identified two small trials (Alexander 1991 and Nishikawa 1996) which fulfilled the inclusion criteria, (total n=17, duration 3-6 weeks). Few data were reported and, because of inappropriate use of crossover methodology, we could not include all of the data in this review. For the few chronically ill people in these trials, neither the 'active' tetracycline bacteriostatic agent, oral demeclocycline, nor the opiate antagonist naloxone, nor placebo, gave any suggestion of serious adverse effects for a period of up to six weeks. The studies did not report any useful data on measures of polydipsia, physical symptoms secondary to increased fluid intake, mental state, general functioning or economic outcomes.

AUTHORS' CONCLUSIONS

The trials offer little useful data to the clinician hoping to treat psychosis-related polydipsia with drugs, except that further evaluative studies need to be conducted in this area. Treatment of any sort for psychosis related polydipsia might only be informative within a well designed, conducted and reported randomised study. The two pioneering studies suggest that larger trials, though difficult, would not be impossible with adequate support and co-ordination.

Identity preservation of genetically modified organisms in the food chain: requirements, methods, and costs

The use of the technology of genetic modification (GM) in European agriculture and the food supply chain is currently controversial. Because of strong anti-GM technology sentiments, the use of ingredients derived from plants containing GM have largely been eliminated from foods manufactured for direct human consumption by the food supply chain in much of the European Union (EU). During the past year, the attention of those opposed to the technology has turned to the use of GM ingredients in livestock production systems by incorporation of GM soy and maize in animal feed. A discussion is presented of the key issues relating to this subject, focusing on how supplies of GM or non-GM products are segregated or how their identities are preserved. The discussion is centered on GM maize and soybeans into which agronomic traits, such as herbicide tolerance and/or insect resistance, have been incorporated. These are currently the only crops into which some varieties containing GM have been approved for use in the EU.

Pharmacological treatments for psychosis-related polydipsia

BACKGROUND

Polydipsia is the intake of more than three litres of fluids per day. Primary polydipsia occurs when excessive drinking cannot be explained by an identified medical condition, and is not secondary to polyuria. The prevalence of this problem in psychiatric inpatients has been estimated at between 6 and 17%. It can hinder standard care and be a highly disabling, even life-threatening condition.

OBJECTIVES

To review the effect of pharmacological interventions for the treatment of psychosis-related polydipsia.

SEARCH STRATEGY

The reviewers searched the Cochrane Schizophrenia Group's Register (January 2002) which is compiled by up-to-date methodical searches of BIOSIS, The Cochrane Library, CINAHL, Dissertation abstracts, EMBASE, LILACS, MEDLINE, PSYNDEX, PsycINFO, RUSSMED and Sociofile and is supplemented with hand searching of relevant journals and numerous conference proceedings. References of all identified studies were also searched for further trials.

SELECTION CRITERIA

All randomised controlled trials involving people with a psychotic illness and secondary polydipsia, which evaluated drug treatments, and measured clinically meaningful outcomes.

DATA COLLECTION AND ANALYSIS

Reviewers, working independently, inspected citations, ordered papers, and then re-inspected and quality assessed the studies. They also worked independently to extract data. For homogeneous dichotomous data, the relative risk (RR), 95% confidence interval (CI), and, where appropriate, the number needed to treat (NNT) and the number needed to harm (NNH), were calculated on an intention-to-treat basis. Reviewers assumed that people who left the study early or were lost to follow-up had no improvement. Weighted mean differences (WMD) were calculated for continuous data. Data was excluded if loss to follow-up was greater than 50%.

MAIN RESULTS

The reviewers identified two trials which fulfilled the inclusion criteria, (total n=17, duration 3-6 weeks). Few data were reported and, because of inappropriate use of crossover methodology, it could not all be used in this review. For the few chronically ill people in these trials, neither the 'active' tetracycline bacteriostatic agent, oral demeclocycline, nor the opiate antagonist naloxone, nor placebo, gave any suggestion of serious adverse effects for a period of up to six weeks. The two small studies did not report any useful data on measures of polydipsia, physical symptoms secondary to increased fluid intake, mental state, general functioning or economic outcomes.

REVIEWER'S CONCLUSIONS

The trials offer little to the clinician hoping to treat psychosis-related polydipsia with drugs, except that further evaluative studies need to be conducted in this area. Treatment of any sort for psychosis related polydipsia might only be informative within a well designed, conducted and reported randomised study. The two pioneering studies suggest that larger trials, though difficult, would not be impossible with adequate support and co-ordination.

Primary malignant melanoma of the cerebellopontine angle

BACKGROUND

Malignant tumors of the cerebellopontine angle are very rare, accounting for less than 1% of lesions at this site. These may be primary or secondary tumors of the temporal bone, central nervous system (CNS), or leptomeninges. Malignant melanoma is uncommon, accounting for 1.5% of all types of malignant tumors. Metastatic melanoma is a frequent cause of CNS metastasis, often with leptomeningeal spread. Primary leptomeningeal melanoma is, however, rare and even more so at the cerebellopontine angle. The prognosis for CNS malignant melanoma is generally very poor.

PATIENT

The authors describe the case of a 29-year-old woman with unilateral hearing loss and facial paresis. Magnetic resonance imaging (MRI) demonstrated a mass that was thought to be an acoustic neuroma but was seen to involve the cochlea as well as the internal auditory meatus and cerebellopontine angle. The lesion was subsequently excised completely by a trans-labyrinthine approach, with facial nerve preservation, and was shown on histologic examination to be a malignant melanoma. Further comprehensive investigation did not reveal a primary extracranial site or any sign of CNS spread. The clinical features of this case, including the radiologic and histologic findings, are described, and literature concerning management is reviewed.

The magnetless Clarion cochlear implant in a patient with neurofibromatosis 2

We present our experience using the Clarion magnetless multichannel cochlear implant with a woman profoundly deafened following bilateral acoustic neuromata as a consequence of neurofibromatosis 2 (NF2). The right neuroma had been previously removed without an attempt at neural preservation. On the left, however, a posterior fossa approach had been taken with the aim of preserving hearing. Although the left cochlear nerve appeared to be undamaged at the end of the operation, no hearing thresholds could be elicited on post-operative audiometry, because of damage either to the cochlear nerve or to the blood supply to the cochlea. Round window electrical stimulation subsequently produced a perception of sound, confirming that the cochlear nerve was capable of functioning and that a cochlear implant would be effective. Because she would need regular magnetic resonance imaging (MRI) to monitor existing and future NF2 lesions, it was decided to use a magnetless Clarion implant, which has been shown to be MRI compatible. We report our experience of using the device in this case and discuss some of the issues related to the provision of cochlear implants to patients with NF2.

Horizontal otolith-ocular responses in humans after unilateral vestibular deafferentation

We studied horizontal eye movements evoked by lateral whole body translation in nine patients who underwent vestibular nerve section. Preoperatively, all had preserved caloric function on both sides. Testing was performed before, 1 week and 6-10 weeks after surgery. Patients were seated upright in an electrically powered car running on a linear track. The car executed acceleration steps of 0.24 g, randomly to the left and right in the dark. The normal response consisted of a bidirectionally symmetrical nystagmus with compensatory slow phases. Response asymmetry of the slow-phase velocity of the desaccaded and averaged eye position signal was less than 13% in normals (n = 21). Before surgery, patients' responses were mostly symmetrical. Postoperatively, responses were diminished or absent with head acceleration towards the operated ear in all patients, causing a marked asymmetry which averaged 56% after correction for spontaneous nystagmus. On follow-up, responses regained symmetry. Thus, early after vestibular nerve section, a single utricle produces a normal LVOR only with ipsilateral head translation. Therefore, afferents for the LVOR seem to originate from the mid-lateral area of the macula, where hair cells are stimulated in their on-direction during ipsilateral head translation. Compensation may depend on recovery of the off-directional responses from lateral hair cells of the remaining utricle.

Deafness and vertigo

This review follows closely on the publication of significant handbooks and symposia concerned with neuro-otology, pharmacology of emesis, imaging, cochlear prostheses and aspects of vertigo which reflect the considerable advances that have been made in clinical and basic neuroscience in these areas in recent years. The value of the cochlear prosthesis has been demonstrated convincingly and may well be a model for the future of brain implantations in diverse disorders of the central nervous system. Imaging of the inner ear has made spectacular advances to provide invaluable aids to diagnosis. Neuro-otologists are becoming aware of the diversity of diseases, particularly those related to hormonal regulation, which may cause or exacerbate symptoms in patients with vertigo. Fortunately for the sufferer, a clearly focussed view is emerging of the pharmacology of overlapping and interrelated problems of emesis, vertigo and migraine which promises an early solution to their integrated management.

Transaural linear vestibulo-ocular reflexes from a single utricle

To clarify the directional sensitivity of a single utricle with respect to the transaural linear vestibulo-ocular reflex (L-VOR) we studied seven patients before and after vestibular neurectomy. Patients were seated upright in an electrically powered car running on a linear track. Transaural acceleration steps of 0.24 g were applied randomly to the left and right in the dark. The slow phase velocity of the L-VOR was measured from the average of the induced compensatory eye movements. L-VOR asymmetry was calculated as (R-L/R + L x 100) and is < 13% in normals. Before surgery, responses were mostly symmetrical. One week after surgery, however, all patients had diminished or absent responses with medial acceleration of the remaining utricle. Asymmetries averaged 65% after correction for spontaneous nystagmus. Our findings indicate that afferents for the L-VOR originate from the lateral region of the macula where hair cells with ipsilateral on-directions are located.

The use of botulinum toxin in the treatment of adductor spasmodic dysphonia

Botulinum toxin injections have been used to treat 31 patients with adductor spasmodic dysphonia. Injections of 3.00-3.75 units of botulinum toxin were performed bilaterally into the thyroarytenoid muscle. This treatment significantly decreased the standard deviation of the fundamental frequency of the speech sample, indicating a reduction in the variability of pitch amongst patients. A total of 96% of patients' subjective diary reports showed an improvement with a median of 7 days to peak effect and a 5 week duration of peak effect.

Immunoblotting of transferrin in the identification of cerebrospinal fluid otorrhoea and rhinorrhoea

Cerebrospinal rhinorrhoea is potentially serious due to the risk from infection. In patients presenting with a nasal discharge of clear fluid it is important to identify the nature of the fluid. Cerebrospinal fluid is readily identified by the presence of asialo-transferrin (tau protein). A method is presented for the identification of tau protein based upon agarose electrophoresis, followed by transfer onto cellulose nitrate membrane and immunochemical detection of transferrin. The method is reliable, sensitive and simple, and requires only basic electrophoresis apparatus.