Holocene biomass burning and global dynamics of the carbon cycle.

Fire regimes have changed during the Holocene due to changes in climate, vegetation, and in human practices. Here, we hypothesise that changes in fire regime may have affected the global CO2 concentration in the atmosphere through the Holocene. Our data are based on quantitative reconstructions of biomass burning deduced from stratified charcoal records from Europe, and South-, Central- and North America, and Oceania to test the fire-carbon release hypothesis. In Europe the significant increase of fire activity is dated approximately 6000 cal. yr ago. In north-eastern North America burning activity was greatest before 7500 years ago, very low between 7500-3000 years, and has been increasing since 3000 years ago. In tropical America, the pattern is more complex and apparently latitudinally zonal. Maximum burning occurred in the southern Amazon basin and in Central America during the middle Holocene, and during the last 2000 years in the northern Amazon basin. In Oceania, biomass burning has decreased since a maximum 5000 years ago. Biomass burning has broadly increased in the Northern and Southern hemispheres throughout the second half of the Holocene associated with changes in climate and human practices. Global fire indices parallel the increase of atmospheric CO2 concentration recorded in Antarctic ice cores. Future issues on carbon dynamics relatively to biomass burning are discussed to improve the quantitative reconstructions.

Effects of lavender straw on stress and travel sickness in pigs.

OBJECTIVE: To observe pigs during road journeys in order to establish whether lavender straw was likely to decrease stress and incidence of travel sickness. SUBJECTS: Forty 70-kg Large White pigs were transported by road for 2 hours, 20 animals each day, over a 2-day period. DESIGN: On day 1, ample wheat straw was provided as bedding such that the floor of the vehicle was entirely covered (straw condition). On day 2, lavender straw was provided as bedding (lavender condition). During the journey, direct behavioral observations of the individually marked pigs were made by scanning every 10 minutes for incidence of standing and lying along with the less severe symptoms of travel sickness (foaming at the mouth and repetitive chomping). Incidences of retching and vomiting were noted as they occurred. A general activity index was also scored every 10 minutes (5 = high activity, 1 = low activity). Saliva samples were taken from each animal at different stages of the journey for analysis of cortisol. RESULTS: Pigs stood more when in the straw condition, but were more active when standing in the lavender condition. Symptoms of travel sickness appeared to be less acute in the lavender condition, with more animals exhibiting the less severe symptom, foaming and chomping (a total of 3 in straw compared with 6 in lavender), but fewer animals showing the more severe symptoms of retching and vomiting (in straw, 3 retched, 6 vomited; in lavender 0 retched, 3 vomited). A total of 6 animals retched or vomited in the straw condition but only 3 in the lavender. There was a significant difference in mean concentrations of cortisol between conditions but this was due to a difference in mean baseline concentrations between groups. CONCLUSION: Addition of lavender straw appeared to decrease incidence and severity of travel sickness but not overall levels of stress (as measured by concentrations of salivary cortisol).

Effects of simulated lairage conditions on the physiology and behaviour of pigs.

The responses of pigs to being driven and mixed together in lairage were investigated. Five groups of six and five groups of seven 70 kg pigs were transported for 40 minutes on a lorry and then subjected to one of the following treatments: two groups were driven down a passage; four groups (A to D) were mixed together for one hour (A and B together, and C and D together); and, four groups were driven down the passage and then mixed ('combined treatment'). The pigs' behaviour was recorded, skin damage was scored and saliva samples were taken for analysis of cortisol. The initial journey increased the pigs' salivary concentration of cortisol. Their behaviour while being driven was not correlated with the concentrations of cortisol after they were driven and cortisol concentrations did not increase relative to post-transport levels. The frequency and duration of fighting when they were mixed were positively correlated with their level of aggression in the home pen and with the increase in concentrations of cortisol when they were mixed. One hour after they had been mixed, the concentrations of cortisol had decreased relative to post-transport levels. After the combined treatment, the correlations observed for the mixing treatment were absent, and the concentrations of cortisol increased relative to post-transport levels. Skin damage was greatest after the groups of pigs were mixed. The responses observed indicate that the combined effects of driving and mixing, which are very common in lairage, were greater than the effects of driving or mixing alone.

Effects of transport and indomethacin on telemetered body temperature and release of cortisol and prolactin in pre-pubertal pigs.

Previous research indicates that acute physical stress (restraint) raises core temperature in growing pigs via a prostaglandin-dependent mechanism. This study investigated whether transport stress affects body temperature in pigs and whether any such changes might involve endogenous prostaglandins. Pre-pubertal boars (n = 7) were implanted with venous catheters and biotelemetry devices for the measurement of core temperature. They were transported for two hours, with and without indomethacin (IND) pre-treatment, and blood samples were taken at 15 minute intervals for the determination of plasma cortisol and prolactin concentrations. The results indicated that, contrary to predictions, body temperature tended to fall during transport and that the effect was exaggerated by IND. By contrast, cortisol concentrations increased during transport and were unaffected by IND whereas the tendency for transport to stimulate prolactin release was reversed by IND.

Welfare aspects of the transport by road of sheep and pigs.

That transport can be stressful to pigs and sheep has been inferred from behavioral and physiological measurements. Duration of journey is more likely to cause stress in pigs than in sheep, but loading and the start of travel are stressful to both. Vibration, related to vehicle design, and the jolting, shocks, and sudden impacts caused by road conditions and manner of driving, are probably of more importance than noise. Ventilation and stocking density can modulate the effects of ambient temperature, which may influence meat quality in pigs. Deprivation of food and water does not appear to stress sheep unduly, but this can become a serious welfare concern in the case of pigs. However, most journeys undertaken by pigs in the European Union are relatively short. In sheep, transport may follow soon after other stressful experiences such as weaning, shearing, handling, or marketing; the interaction of these factors in causing cumulative stress has not been studied. In pigs, fighting after the mixing of previously unacquainted animals is well known to be a welfare issue that can compromise meat quality. Considering the public interest in livestock transport and the large amounts of money involved, surprisingly little research has been done in the area, and more is urgently needed for legislation and welfare codes to be soundly based on scientific knowledge.

Slides of conspecifics as representatives of real animals in laying hens (Gallus domesticus).

Four 18-week-old Ross Brown laying hens were trained to discriminate between slides of the heads of familiar or unfamiliar conspecifics. Those individuals trained to discriminate between slides of familiar conspecifics failed to show a better discrimination ability when presented with slides of novel views of these object birds, as compared with subjects trained to discriminate between slides of unfamiliar conspecifics and presented with similar corresponding novel views. There was also no evidence that subjects learnt to discriminate slides of familiar conspecifics more quickly than slides of unfamiliar conspecifics. It was concluded that there was no evidence that the hens perceived the slides presented as representations of their group members.

Discrimination of group members by laying hens Gallus domesticus.

Two experiments were performed to test if hens could discriminate between conspecifics in learning experiments. In experiment 1, three adult hens were trained to discriminate between a member of their own social group and a member of a neighbouring group. Only one test bird showed evidence of discrimination above conventional levels of significance. In experiment 2, three hens were trained to discriminate between two members from their own social group. All test birds showed strong evidence of discrimination above conventional levels of significance indicating that laying hens are able to discriminate between members of their own social group.

A social essay on special issues facing poor women of color.

Race, gender, and socioeconomic status place poor women of color in triple jeopardy for subservience. Racism, sexism, impoverishment, and discrimination in a variety of services serve to deny poor women of color the opportunities in education, occupations, income, and health services that are afforded other groups in this country. This paper shows that the fight for civil rights is also one for preventive and quality, accessible and comprehensive care for those who suffer most: poor women of color, and that until this nation is purged of these egregious and reprehensible forces, the goal of a true democracy will continue to elude us.