Incorporating temporality and biophysical vulnerability to quantify the human spatial footprint on ecosystems

Land use is a pervasive influence on most terrestrial ecosystems. Humans are converting natural ecosystems and appropriating an increasingly large portion of the net primary productivity of the Earth’s ecosystems, leaving a rapidly expanding footprint on the environment and threatening the functioning of ecosystems and the ecological services they provide. Understanding the impacts of human activities on the environment from a local to a global scale requires an adequate representation of human modified landscapes and an explanation of the relationships between socioeconomic and biophysical factors. A first step towards this objective is the development of a quantitative measure of the spatial footprint of humans on landscapes, which can then be used as an analytical and monitoring tool for global change, biodiversity and ecosystem studies. Existing approaches have been based mainly on geographic proxies of human influence such as population density, land transformation, accessibility and infrastructure. In this paper, we developed a more comprehensive and spatially-explicit footprint index based on three dimensions: land use intensity, intervention time, and biophysical vulnerability, which we then applied to Colombia as a case study. We found the inclusion of the vulnerability index provided an effective means to address regional variability in biophysical responses to land use impacts. Accounting for the duration of human intervention provided new insights into the relative capacity of ecosystems to recover or be restored. From this knowledge, more appropriate land use policies can be developed.     

The prevalence and risk factors of oesophageal and nonglandular gastric lesions in Thoroughbred racehorses in Saskatchewan

The objective of this study was to investigate the prevalence, severity and risk factors associated with oesophageal and nonglandular gastric lesions in Thoroughbred racehorses in active training in Saskatoon. Mature Thoroughbred horses (n = 94), stabled at Marquis Downs racetrack in Saskatoon, Saskatchewan, Canada, and trained by different trainers (n = 14) for a minimum of one month were included in the study. Horses were examined by gastroscopy and a lesion grade was assigned for each individual horse. Of the 94 horses, 79 (84%) had nonglandular gastric lesions, 70 (74.5%) had gastric ulcers, giving a prevalence of 74.5%, and 9 out of 94 horses (9.6%) had hyperkeratosis and/or hyperaemia. None of the horses had oesophageal lesions. Gender, age, number of races raced, place obtained in those races, history of lameness, history of medical conditions, and history of medications in a 2 month period prior to the gastroscopic examination were not statistically significant as potential risk factors for the prevalence and severity of nonglandular gastric lesions.     

Comparison of three preoperative skin preparation techniques in ponies

The purpose of this study was to evaluate the efficacy of 3 preoperative skin preparations (povidone‐iodine [PI] removed with 70% isopropanol, and 4% chlorhexidine gluconate [CG] removed with either 70% isopropanol [CA] or sterile saline solution [CS]) in ponies. Eighteen ponies were randomly assigned to one of the 3 preoperative skin preparation groups. The skin of ponies was aseptically prepared with PI removed with alcohol, or 4% CG removed with either alcohol or sterile saline solution. The antimicrobial efficacy of each skin preparation technique was assessed quantitatively by culturing for surface bacteria with replicating organism detection and counting plates. The percentage of negative cultures, the percentage of cultures with >5 colony forming units (CFU) and the percentage bacterial reduction after the cleansing scrub, the sterile scrub, and the surgical procedures were compared. There was a significant difference between CG and PI in percentage bacterial reduction after the cleansing scrub, but no significant difference at any other time (sterile scrub, post operative skin sampling). In a comparison of the number of negative microbial cultures at each sampling point, there were no significant differences among the 3 skin preparation techniques. There were no significant differences among the treatment groups comparing the number of cultures with a high colony count (>5 CFU) after the cleansing scrub. Skin preparation with CS and PI resulted in significantly fewer cultures with >5 CFU after the sterile scrub than CA. Post operatively, CA had a higher number of samples with >5 CFU than CS and PI. PI removed with alcohol and 4% CS are equally effective in the reduction of skin bacteria after a sterile skin scrub in the operating room; however, CG was more effective in reducing bacterial numbers after the cleansing scrub. The number of cultures with high bacterial counts was greater post operatively, when alcohol was used as a rinse with chlorhexidine. In cases where a sterile scrub is not performed following a cleansing scrub, CG may be a better choice than PI. CA should not be used as a presurgical skin preparation method in ponies.     

Leptospirosis in farmed deer in New Zealand : a review

Current knowledge of leptospirosis in farmed deer in New Zealand is reviewed. Over the past 25 years, leptospirosis has been reported to occur in individual cases as well as in herd outbreaks in farmed deer and in human cases linked to farmed deer. Serological studies and evidence from bacterial culture suggest infection is widespread. Mixing of young stock from several sources appears to be a significant risk factor for outbreaks. The culture of Leptospira interrogans serovars Hardjobovis, Pomona and Copenhageni has been reported. Infection with serovar Hardjobovis had the highest prevalence, either individually or mixed with serovar Pomona. Infection with serovar Copenhageni appears uncommon and its pathogenicity in deer is unproven. Titres to serovars Australis, Ballum, Balcanica and Tarassovi have been reported. Deer appear to be maintenance hosts for serovar Hardjobovis, incidental or accidental hosts and probably a maintenance population for serovar Pomona, since some infections persist for several months, and accidental hosts for serovar Copenhageni. Serovar Pomona appears to produce clinical and probably subclinical disease, whereas serovar Hardjobovis appears to cause only subclinical disease, although the relative risk of disease causation has not been determined. Clinical disease is usually manifested by haemolysis, jaundice, renal lesions, haemoglobinuria and often by sudden death. Renal lesions are commonly observed at slaughter and many are associated with leptospiral infections. Occupationally, slaughterhouse workers appear to be at greatest risk of contracting the disease from deer. Vaccination produces serological responses, but its effectiveness in protecting against disease, and prevention or reduction of shedding in urine, has not yet been confirmed in deer. More robust knowledge of the epidemiology of leptospiral infections in deer, and the effectiveness of vaccines and vaccination regimes, is needed to assist the deer industry to develop a strategy to manage this disease.