Zoo visitor effect on mammal behaviour: Does noise matter?

The zoo visitor effect is the change in animal behaviour and physiology in response to the presence of a viewing public. It is thought to result from, amongst other things, visitor generated sound (i.e., noise), but this hypothesis has never been explicitly tested. We tested this hypothesis through observations on the behaviour and enclosure use of 12 mammal species held in 12 separate enclosures at the Belo Horizonte Zoo when exposed to different sound pressure levels (i.e., noise) from the visiting public. Noise pollution levels were significantly higher with the public present and increased with increasing audience size. Species that are more popular suffered greater noise pollution from the zoo visitors. No overall effects on behaviour were found in relation to noise levels, however, analysis of behaviour at the individual level found some significant differences. Notably, half of the individuals increased their vigilance behaviour with increasing sound levels and approximately one-third of individuals increased their movements. These results show that zoo visitors have a negative welfare impact on individual zoo-housed mammals, especially groups of noisy visitors where levels were recorded outside of the recommended limits for human well-being (>70 dB(A)). Thus, zoos need to address this issue, probably, through a combination of visitor education campaigns and acoustic modification to enclosures

Microwave assisted extraction of polysaccharide

In this chapter, the use of microwave irradiation has been reviewed and dicussed for the extraction of polysaccharides as well as for combined processes involving extraction and hydrolysis of these compounds. Special attention has been paid to polysaccharides with bioactive properties. Fundamentals and instrumentation, together with a detailed discussion on the effect of the most important parameters affecting the microwave-assisted extraction (MAE) process are presented. Some of the most recent and outstanding applications of MAE for the extraction of polysaccharides, mainly from food matrices or food byproducts, are described and classified according to the type of polysaccharide extracted. The comparison in terms of speed, yield, etc. of MAE with other conventional (solid-liquid extraction) or emerging techniques (pressurized liquid extraction, ultrasound-assisted extraction) is also shown. The scale-up of MAE technique and the development of hybrid systems (e.g. ultrasound-microwave-assisted extraction, UMAE) are presented as future trends. To conclude, MAE is presented as a promising emerging technique for extraction of polysaccharides from natural sources.Peer reviewe

Microwave-assisted extraction of polysaccharides

In this chapter, the use of microwave irradiation has been reviewed and discussed for the extraction of polysaccharides as well as for combined processes involving extraction and hydrolysis of these compounds. Special attention has been paid to polysaccharides with bioactive properties. Fundamentals and instrumentation, together with a detailed discussion on the effect of the most important parameters affecting the microwave-assisted extraction (MAE) process, are presented. Some of the most recent and outstanding applications of MAE for the extraction of polysaccharides, mainly from food matrices or food by-products, are described and classified according to the type of polysaccharide extracted. The comparison in terms of speed, yield, etc. of MAE with other conventional (solid–liquid extraction) or emerging techniques (pressurized liquid extraction, ultrasound-assisted extraction) is also shown. The scale-up of MAE technique and the development of hybrid systems (e.g., ultrasonic–microwave-assisted extraction, UMAE) are shown as future trends. To conclude, MAE is shown as a promising emerging technique for extraction of polysaccharides from natural sources.This work has been funded by Ministerio de Economía y Competitividad (project CTQ2012-32957), Junta de Andalucía (project AGR-7626), and Comunidad de Madrid (project Avansecal). L. Ruiz-Aceituno is supported by a JAE-Predoc grant from CSIC and cofinanced by the European Social Fund (ESF). A.C.S. thanks Ministerio de Economía y Competitividad of Spain for a Ramón y Cajal contract.Peer reviewe