The Family Name as Socio-Cultural Feature and Genetic Metaphor: From Concepts to Methods

A recent workshop entitled The Family Name as Socio-Cultural Feature and Genetic Metaphor: From Concepts to Methods was held in Paris in December 2010, sponsored by the French National Centre for Scientific Research (CNRS) and by the journal Human Biology. This workshop was intended to foster a debate on questions related to the family names and to compare different multidisciplinary approaches involving geneticists, historians, geographers, sociologists and social anthropologists. This collective paper presents a collection of selected communications

Effects of nitrogen and sulfur fertilization on free amino acids, sugars, and acrylamide-forming potential in potato

Nitrogen (N) fertilizer is used routinely in potato (Solanum tuberosum) cultivation to maximize yield. However, it also affects sugar and free amino acid concentrations in potato tubers, and this has potential implications for food quality and safety because free amino acids and reducing sugars participate in the Maillard reaction during high-temperature cooking and processing. This results in the formation of color, aroma, and flavor compounds, but also some undesirable contaminants, including acrylamide, which forms when the amino acid that participates in the final stages of the reaction is asparagine. Another mineral, sulfur (S), also has profound effects on tuber composition. In this study, 13 varieties of potato were grown in a field trial in 2010 and treated with different combinations of N and S. Potatoes were analyzed immediately after harvest to show the effect of N and S fertilization on concentrations of free asparagine, other free amino acids, sugars, and acrylamide-forming potential. The study showed that N application can affect acrylamide-forming potential in potatoes but that the effect is type- (French fry, chipping, and boiling) and variety-dependent, with most varieties showing an increase in acrylamide formation in response to increased N but two showing a decrease. S application reduced glucose concentrations and mitigated the effect of high N application on the acrylamide-forming potential of some of the French fry-type potatoes

Convergent evolution between insect and mammalian audition

In mammals, hearing is dependent on three canonical processing stages: (i) an eardrum collecting sound, (ii) a middle ear impedance converter, and (iii) a cochlear frequency analyzer. Here, we show that some insects, such as rainforest katydids, possess equivalent biophysical mechanisms for auditory processing. Although katydid ears are among the smallest in all organisms, these ears perform the crucial stage of air-to-liquid impedance conversion and signal amplification, with the use of a distinct tympanal lever system. Further along the chain of hearing, spectral sound analysis is achieved through dispersive wave propagation across a fluid substrate, as in the mammalian cochlea. Thus, two phylogenetically remote organisms, katydids and mammals, have evolved a series of convergent solutions to common biophysical problems, despite their reliance on very different morphological substrates

Acrylamide: new European risk management measures and prospects for reducing the acrylamide-forming potential of wheat

Acrylamide (C3H5NO) is a processing contaminant formed from free asparagine and reducing sugars during high-temperature cooking and processing. It is a Group 2A carcinogen, and the European Food Safety Authority (EFSA) Panel on Contaminants in the Food Chain (CONTAM Panel) has expressed concern for the potential tumor-inducing effects of dietary exposure. Potato, coffee, and cereal products are the major contributors to dietary acrylamide intake. The European Commission recently introduced strengthened risk management regulations for acrylamide in food, including compulsory mitigation measures and new benchmark levels. Measures adopted to reduce acrylamide formation in potato chips in Europe resulted in a 53% decrease from 2002 to 2011. However, since 2011 there has been a leveling off, suggesting that the easy gains have already been made. Acrylamide levels in chips are influenced by seasonal and geographical factors, making regulatory compliance more difficult. In cereals, acrylamide formation is determined by free asparagine concentration, and this differs substantially between varieties. We would support the inclusion of information on grain asparagine concentration in variety descriptions. However, crop management, including ensuring good disease control and sulfur sufficiency, is also important. A key enzyme in asparagine synthesis is asparagine synthetase. Wheat has four asparagine synthetase genes, TaASN1–4. Gene expression and biochemical data have identified TaASN2 as a prime target for genetic interventions to reduce wheat’s acrylamide-forming potential

Reducing the acrylamide-forming potential of crop plants

Acrylamide is a food processing contaminant formed from free asparagine and reducing sugars during high-temperature cooking and processing. It is a Group 2A carcinogen, and EFSA’s CONTAM Panel has expressed concern for the potential tumour-inducing effects of dietary exposure. Fried, baked, roasted and toasted potato, coffee and cereal products are the major contributors to dietary acrylamide intake. The European Commission has recently introduced strengthened risk management regulations for acrylamide in food, including compulsory mitigation measures and new Benchmark Levels. Steps taken by manufacturers to reduce acrylamide formation in potato chips in Europe resulted in a 53 % decrease from 2002 to 2011. However, since 2011 there has been a levelling off, suggesting that the easy gains have already been made and further large reductions are unlikely. The acrylamide-forming potential of potatoes is influenced by seasonal and geographical factors, making regulatory compliance for potato products more difficult. In cereals, acrylamide formation is determined by free asparagine concentration: this differs substantially between varieties but is also very responsive to environmental factors and crop management. Ensuring good disease control and sulfur sufficiency are particularly important. The relationship between precursor concentration and acrylamide formation is more complex in potato, with the concentration of reducing sugars the more important parameter in most datasets but free asparagine concentration contributing to the variance. Storage is a key issue for potatoes due to the phenomena of cold and senescent sweetening. Investigations into the genetic control of acrylamide formation in wheat have focussed on asparagine metabolism, in particular asparagine synthetase, while biotech potatoes with reduced expression of asparagine synthetase and vacuolar invertase are already on the market in the USA