The Mexican tortilla crisis of 2007: the impacts of grain-price increases on food-production chains
This article examines the case of the Mexican ‘tortilla crisis’ of 2007. Drawing on reviews of literature and the media, key-informant interviews, and secondary databases, the authors explore the response of the Mexican maize–tortilla chain to a price shock. Price increases should theoretically be passed on to the consumer as a progressively less significant percentage of the overall price of value-added food products. However, in Mexico, price increases were magnified along the maize–tortilla production chain. This was due largely to asymmetries among segments of the chain, which conditioned the responses of industrial-scale corporations and small-scale family businesses. This case study suggests that, in order to understand the impacts of price-shocks on poor consumers, more detailed, country-level analyses of market chains and price-transmission structures are needed.
Threats of Tar Spot Complex disease of maize in the United States of America and its global consequences
The emergence and spread of new crop diseases threatens the global food security situation. Phyllachora maydis, one of the three fungal pathogens involved in Tar Spot Complex (TSC) of maize, a disease native to Latin American countries, was detected for the first time in the United States of America (USA) in 2015. Although TSC has been previously reported to cause up to 50% of yield losses in maize in Latin America, the impact of P. maydis alone on maize yield is not known yet. However, there is a possibility that Monographella maydis, the second most important pathogen involved in TSC, would be introduced to the USA and would become associated with P. maydis and both pathogens could form the devastating complex disease in the country. The first objective of this study was to identify the TSC-vulnerable maize-producing regions across the USA by applying a climate homologue modeling procedure. The second objective was to quantify the potential economic impact of the disease on the maize industry in the USA. This study showed that even a 1% loss in maize production caused by the disease could potentially lead to a reduction in maize production by 1.5 million metric tons of grain worth US$231.6 million. Such production losses will affect not only the maize-related industries in the USA but also the food security in a number of low-income countries that are heavily dependent on US maize imports. This, in turn, may lead to increased poverty and starvation and, in some cases, to social unrest due to increased prices of maize-based staple foods. The study is intended to raise public awareness regarding potential TSC outbreaks and to develop strategies and action plans for such scenarios.
Mechanism of the depressor response to dopamine in the rat treated with phenoxybenzamine.
Alterations of hypotensive responses to dopamine by antagonists were characterized in alpha-blocked, anaesthetized rats. Responses were not affected by d-propranolol (0.1 mg/kg) whereas d,1-propranolol (0.1 mg/kg) or haloperidol (1.0 mg/kg) attenuated them; higher doses of inhibitors (1.0 mg/kg; 5.0 mg/kg, respectively) failed to produce a higher inhibition, but combinations of low doses abolished the depressor responses. In adrenalectomized rats, hypotensive responses decreased; haloperidol always attenuated the responses while d,1-propranolol became ineffective. Dopamine produced an enhancement of plasma adrenaline and noradrenaline levels, which was decreased by d,1-propranolol and increased by haloperidol. The data suggest that in rats the depressor component of dopamine is due to activation of both dopaminergic and beta-adrenoceptors. The beta component appears to be due to the release of adrenaline. The results also support the concept of the existence in sympathetic nerve endings and adrenal glands of stimulatory beta-adrenergic and inhibitory dopaminergic prejunctional receptors.