Quantification of Heavy Metals from A.M.D. Discharged into a Public Water Supply Dam in the Iberian Pyrite Belt (SW Spain) Using Centered Moving Average

In this work, the determination of moving averages is proposed as a method for quantifying metal, arsenic, and sulfate discharges into a water course undergoing acid mine drainage processes which flows into a public water supply dam in the Iberian Pyrite Belt. The analysis of the results obtained by applying moving averages shows that the highest metal and sulfate concentrations occur in October, coinciding with the first rainfall and the sponging of mine dumps, with November and December being the months when the highest contributions to the Andevalo Dam take place. The discharge of acid mine waters with its corresponding metal load into the Andevalo Dam means, for a single hydrological year, more than 6,000 t of sulfates, almost 600 t of iron, and 1 t of As, of special relevance for the hydrochemical quality of the stored waters. When they arrive at the dam, these metals precipitate, since the water pH is near 7, and remain latent in the bottom sediment as long as the chemical makeup of the dam water does not change.     

Ripened dairy products differentially affect hepatic lipid content and adipose tissue oxidative stress markers in obese and type 2 diabetic mice

Growing evidence suggests that the consumption of dairy products may contribute to a reduced incidence of cardiovascular risk factors, such as obesity, dyslipidemia, and type 2 diabetes. The fatty acid composition in milk fat, the duration of ripening, and the complexity of the food matrices are important factors that may interfere with the physiological impact. In this study, we treated genetic obese and type 2 diabetic mice (db/db) for 4 weeks with different dairy (cheese-based) products, differing by the duration of ripening (0, 15, or 35 days). We found that 35 days ripened product significantly improved glucose tolerance, an effect associated with a decreased adipose tissue lipid peroxide markers (TBARS and NAPDH-oxidase mRNA expression), without affecting body weight, food intake, and fat mass. Both fermented matrices significantly decreased the hepatic lipid content, without modifying plasma triglycerides or plasma total cholesterol. These data suggest that dairy products issued from longer ripening positively impact glucose tolerance, hepatic steatosis, and adipose tissue oxidative stress. Further investigations are warranted to decipher the interactions between milk products fermentation, lipids, and host metabolism.     

Patterns of harvesting foliage and bark from the multipurpose tree Khaya senegalensis in Benin: Variation across ecological regions and its impacts on population structure

Non-timber forest products (NTFPs) represent important resources for millions of communities worldwide. Concerns over NTFP overexploitation has led to a growing number of studies on the ecological impacts of harvest. Few studies however, have addressed species harvested for multiple parts or investigated how spatial variation affects harvest patterns and their impacts. We documented rates and patterns of pruning and debarking and their impacts on density and population structure, for 12 populations of the multiuse tree, Khaya senegalensis (Meliaceae) in two ecological regions (Sudano-Guinean versus Sudanian) of Benin, West Africa. Half of the populations had low or no harvest and half were highly harvested. Patterns of pruning and debarking were size-specific, with harvesters tending to prefer larger trees. Foliage harvest pressures were very high across both regions, with >70% of trees harvested for 100% of their crowns. A significantly greater proportion of trees were harvested for foliage in the wetter Sudano-Guinean region than in Sudanian region. The reverse was true for the proportion of foliage and bark-harvested per tree. In the Sudano-Guinean region, high harvest populations had significantly lower densities of seedlings and saplings than low harvest populations. The size-class distribution coefficient of skewness was significantly correlated with rainfall, habitat, and soil type. Variation in harvesting patterns and their ecological impacts can be explained in large part by differences in water availability between the two regions. Effective conservation plans for K. senegalensis require close consideration of the environmental and land-use context in which populations occur.     

Chronic toxicity of unresolved complex mixtures (UCM) of hydrocarbons in marine sediments

Background, Aim and Scope  Unresolved complex mixtures (UCM) of hydrocarbons, containing many thousands of compounds which cannot be resolved by conventional gas chromatography (GC), are common contaminants of sediments but little is known of their potential to affect sediment-dwelling organisms. Evidence exists for reduced health status in mussels, arising from aqueous exposure to aromatic UCM components acting through a narcotic mode of action. However, UCM contaminants in sediments may not be sufficiently bioavailable to elicit toxic effects. The aim of our study was therefore to measure the sublethal effects of chronic exposure to model UCM-dominated oils at environmentally realistic concentrations and compare this to effects produced by a UCM containing weathered crude oil. A further aim was to determine which, if any, fractions of the oils were responsible for any observed toxicity. Materials and Methods  Whole oils were spiked into estuarine sediment to give nominal concentrations of 500 μg g⁻¹ dry weight. Juveniles of the estuarine amphipod Corophium volutator were exposed to the contaminated sediment for 35 days and their survival, growth rate and reproductive success quantified. Using an effect-directed fractionation approach, the oils were fractionated into aliphatic and two aromatic fractions by open column chromatography and their toxicity assessed by further chronic exposures using juvenile C. volutator. Results  The growth rates of amphipods were reduced following exposure to the oils although this was only statistically significant for the weathered oil; reproductive success was reduced by all oil exposures. Sediment spiked with UCM fractions also caused reduced growth and reproduction but no particular fraction was found to be responsible for the observed toxicity. Survivorship was not affected by any oil or fraction. Discussion  The study showed that chronic exposure to sediments contaminated by UCM-dominated oils could have population level effects on amphipods. The observed effects could not be explained by hydrocarbons resolved by conventional GC and effects were similar for both UCM-dominated and weathered oils. All of the fractions appeared to contribute to the observed effects; this is in contrast to previous research which had shown that an aliphatic UCM did not cause adverse effects in mussels. Conclusions  To our knowledge, this is the first study to demonstrate population-level effects arising from exposure to sediments contaminated by realistic environmental concentrations of UCM hydrocarbons. The results are consistent with many compounds, at very low individual concentrations, contributing towards the overall observed toxicity. Recommendations  Risk assessments of contaminated sediments should take into account the contribution towards the potential for toxic effects from UCM hydrocarbons. Studies into sediment contamination should report both aliphatic and aromatic UCM concentrations to aid risk assessments. ESS-Submission Editor: Henner Hollert (hollert@uni-heidelberg.de) This paper has been developed from a presentation at SETAC Europe 16^th Annual Meeting 2006 held at the The Hague, The Netherlands.     

Resistance of Organic Horizon to Acidification from Snowmelt in Podzolic Soil of the Kola Peninsula (6 pp)

Background  

The Kola Peninsula (the most northern region of the European fringe of Russia) is covered with podzolic soil and is considered the most sensitive area to acidification in Europe because of the low input rate of base cations by weathering. About 300 thousand tons of SO2 are annually emitted from stationary sources in this region. Acidic precipitation accumulates in the snow during winter, and acidic water suddenly flushes into the soil during spring snowmelt (so-called acid shock). It is therefore important to assess how the acid-sensitive podzol responds to an intensive increase in acid load. The main purpose of this paper is to show the observed data rather than to provide an analytical interpretation of the observed phenomenon.     

Systemic coccidioidomycosis in a llama cria native to Missouri

A 3-mo-old male llama was examined because of a 4-wk history of lethargy and ill thrift. Clinical examination revealed subcutaneous masses in the left prescapular and right inguinal regions, mild ataxia, a slight head tilt to the right, and right ear droop. The cria died before clinical workup was complete. At autopsy, there was generalized lymphadenomegaly, a hepatic nodule, a midbrain mass causing rostral compression of the cerebellum, and internal hydrocephalus. Microscopic findings included pyogranulomatous lymphadenitis, meningoencephalitis, hepatitis, and bronchopneumonia. Intralesional fungal spherules, most consistent with Coccidioides spp., were identified in the lymph nodes, lung, and brain. Fungal culture, single-nucleotide variation genotyping real-time PCR, and DNA sequencing confirmed Coccidioides posadasii. The dam of the cria was native to Arizona and had been moved to Missouri ~2.5 y previously. Agar gel immunodiffusion assay of the herd revealed that only the dam was positive for Coccidioides spp.; 6 herdmates were negative. Computed tomography of the dam revealed multiple nodules within the lungs and liver, which were presumed to be an active coccidioidomycosis infection. This case of systemic coccidioidomycosis in a llama native to Missouri was presumably acquired by vertical transmission from the dam.     

Viability of equine articular chondrocytes in alginate beads exposed to different oxygen tensions

Ischaemia and reperfusion are suspected to alter chondrocyte metabolism. Here, we studied the effects of three oxygen (O2) tensions on the viability of equine articular chondrocytes isolated from the cartilage of the distal interphalangeal joint of horses. Chondrocytes were cultured in alginate beads under 1%, 5% or 21% gas phase O2 concentration for 14 days, cellular growth kinetics were measured (n=6), and the cells were observed by light microscopy after staining for necrotic and apoptotic cell detection. For information about the metabolic status, the intracellular adenosine triphosphate (ATP) content was measured. The number of chondrocytes remained stable for the first eight days, then decreased especially at 1% and 21% O2. At 21% O2, normal cells decreased and necrotic cells increased at the end of the 14 day-period. No significant variations were found at 5% O2 except for a decrease in necrotic cells at day 14. Most apoptotic cells were found at 1% O2 from days 5 to 11, and normal cells decreased during the same period. But an unexpected increase in normal cells and decrease in apoptotic cells were observed at day 14. The intracellular ATP content remained stable. It was concluded that, in a three-dimensional culture model of equine articular chondrocytes, O2 tension affected the viability of the cells after an 11-day period, with the most important effects observed at 21% and 1% O2 conditions.     

Ileal impaction in 22 cows

The clinical signs, diagnosis, treatment and outcome of 22 cows with ileal impaction were investigated using the medical records of bovine patients referred to the Department of Farm Animals, Vetsuisse Faculty, University of Zurich from 1993 to 2003. Only 15 of the cows had signs of colic, which were subtle but slowly increased in severity in some patients. The results of haematological and biochemical analyses were mildly abnormal in only few animals. There was no correlation between the duration of the disorder before admission, the severity of symptoms and the results of the haematological and biochemical analyses. Dilated loops of small intestine in the right dorsal quadrant of the abdomen could be palpated transrectally and imaged via ultrasonography. A definitive diagnosis of ileal impaction was made during exploratory laparotomy by finding the impaction and ruling out other abnormalities. In 19 cows, the obstructing food mass was easily massaged into the caecum, and in three animals an enterotomy was carried out. All cows had an uneventful recovery with no recurrence of the disorder. It is concluded that the cause of the impaction was most likely due to seasonal influences and winter-feeding with a hay based ration. The short and long-term prognosis after surgical intervention was good.     

Plasma Concentration of Insulin-like Growth Factor I (IGF-I) in Growing Ardenner Horses Suffering from Juvenile Digital Degenerative Osteoarthropathy

Degenerative osteoarthropathy resulting in a reduced active lifespan was observed in Ardenner horses. In the context of joint biology, insulin-like growth factor I (IGF-I) is a potential candidate to affect the anabolism of cartilage matrix molecules. A group of 30 Ardenner horses reared under standardized conditions from weaning were evaluated periodically from 15 to 28 months of age to detect the early manifestations of the disease. At the end of this period, horses were classified in two pathological groups related to the degree of interphalangeal degenerative osteoarthropathy based on clinical and radiographic evaluations: healthy (46.7%) and pathological (53.3%) horses. Seven sequential blood samples were taken from each horse (during the evaluation period) to study the variation of IGF-I plasma concentration. We tested the variations of the IGF-I plasma concentration during growth, and the effect of sex and of pathological classes. Significant variations were observed during the research period, with a maximum value corresponding to spring and a minimum in autumn. A significant reduction of the IGF-I plasma concentration was also observed in the pathological horses (433.5 +/- 19.5 ng/ml) compared to the healthy horses (493.9 +/- 18.2 ng/ml). An alteration in the level of this growth factor could induce a disregulation of the mechanisms involved in the local control of joint and bone tissue development.