Early detection of viral excretion from experimentally infected goats with peste-des-petits ruminants virus

We observed 15 goats for 9 days after subcutaneous infection with 10(3) TCID(50) with isolates of peste-des-petits ruminants virus from Africa and India and five concurrent, uninfected control goats. Typical clinical signs of the infection were present in all 15 infected goats by day 8 and in most by day 6 and some signs were present by day 4. However, 6 out of 15 goats already have detectable virus shedding by day 3 and four more were shedding by day 4 and every goat had virus shedding for at least 1 day before the recognition of clinical signs. This experiment indicates that incubatory carriers therefore might play a role in the transmission of PPRV among small ruminants.     

The increasing risk of Lyme disease in Canada

There is an increasing risk of Lyme disease in Canada due to range expansion of the tick vector, Ixodes scapularis. The objectives of this article are to i) raise public awareness with the help of veterinarians on the emerging and expanding risk of Lyme disease across Canada, ii) review the key clinical features of Lyme disease in dogs, and iii) provide recommendations for veterinarians on the management of Lyme disease in dogs.     

cDNA clone of a putative peanut (Arachis hypogaea L.) trypsin inhibitor has homology with peanut allergens Ara h 3 and Ara h 4

Trypsin inhibitors are pathogenesis-related (PR) proteins, which play an important role in the plant defense mechanism against insects and pathogens. Peanut trypsin inhibitors are low molecular mass seed storage proteins. Like peanut allergens, they are stable to acid and heat, resistant to digestion, and can have a negative impact on human health. In peanut, five Bowman-Birk trypsin inhibitors (BBTI) have been isolated and amino acid sequences published. However, to date, no peanut BBTI sequence is available at both the cDNA and the genomic levels. The objectives of this investigation were (i) to synthesize degenerate oligonucleotides based on conserved regions of published amino acid sequences of BBTI, BII, and BIII; (ii) to isolate, sequence, and analyze at least one positive peanut trypsin inhibitor cDNA clone using the synthesized (32)P-labeled oligonucleotides as probes; and (iii) to determine its trypsin inhibitory activity. Thirty-two degenerate oligonucleotides DNA primers of 24 nucleotides each were synthesized based on the published amino acid sequences of peanut BBTI, and two were selected as probes to screen a peanut Lambda gt 11 cDNA library. Three putative positive clones were isolated, purified, and subcloned, and one was sequenced. Sequence analysis revealed a partial cDNA clone of 643 bp with a start codon. This clone shares 93 and 96% nucleotide sequence homology with peanut allergens Ara h 3 and Ara h 4 cDNA clones, respectively. A trypsin inhibitor assay revealed that peanut allergen Ara h 3 has a trypsin inhibitory activity of 11 238 TIA/mg protein. We concluded that peanut allergen Ara h 3 may also function as a trypsin inhibitor.     

Comparative genomics of trypanosomatid parasitic protozoa

A comparison of gene content and genome architecture of Trypanosoma brucei, Trypanosoma cruzi, and Leishmania major, three related pathogens with different life cycles and disease pathology, revealed a conserved core proteome of about 6200 genes in large syntenic polycistronic gene clusters. Many species-specific genes, especially large surface antigen families, occur at nonsyntenic chromosome-internal and subtelomeric regions. Retroelements, structural RNAs, and gene family expansion are often associated with syntenic discontinuities that-along with gene divergence, acquisition and loss, and rearrangement within the syntenic regions-have shaped the genomes of each parasite. Contrary to recent reports, our analyses reveal no evidence that these species are descended from an ancestor that contained a photosynthetic endosymbiont.     

Reuse of domestic wastewater treated in macrophyte ponds to irrigate tomato and eggplant in semi-arid West-Africa: Benefits and risks

The scarcity of freshwater resources is a critical problem in semi-arid zones and marginal quality water is increasingly being used in agriculture. This paper aimed at evaluating the physico-chemical and biological risks on irrigated soils and fruits of macrophyte treated wastewater (TWW), the nutrients supply, and the effect on tomato and eggplant production in semi-arid Burkina Faso. During three years of experiments, treated wastewater was used, with fresh water as control, in combination with or without mineral fertilizer application at recommended rate (140 kg N/ha + 180 kg P₂O₅/ha + 180 kg K₂O/ha). The study revealed that the treated wastewater provided variable nutrients supply depending on year and element. The treated wastewater without mineral fertilizer improved eggplant yield (40% in average) compared to the freshwater. Both crops responded better to mineral fertilizer (52% for tomato and 82% for eggplant) and the effects of the treated wastewater and fertilizer were additive. As the N supply of TWW was very unsteady (8-227% of crop need), and P₂O₅ supply did not satisfy in whole crop need (3-58%) during any of the three years of experiment, we recommended that moderate N and P₂O₅ fertilizers be applied when irrigating with TWW in semi-arid West-Africa. On the contrary, the K₂O supply was more steady and close to crop requirement (78-126%) over the three years of experiment and no addition of K fertilizer may be needed when irrigated with TWW. Faecal coliforms and helminth eggs were observed in treated wastewater and irrigated soils at rate over the FAO and WHO recommended limits for vegetable to be eaten uncooked. Tomato fruits were observed to be faecal coliform contaminated with the direct on-foliage irrigation with treated wastewater. Our results indicate that treated wastewater can effectively be used as both nutrients source and crop water supply in market gardening in the semi-arid Sub-Saharan West Africa (SSWA) where freshwater and farm income are limiting. Yet consumers should properly cook or disinfect treated-wastewater irrigated vegetables before eating, and market gardeners should also be careful manipulating treated wastewater to avoid direct health contamination in this environment.     

Determination of polycyclic aromatic hydrocarbons in coffee brew using solid-phase extraction

The presence of polycyclic aromatic hydrocarbons (PAHs) in coffee has been reported and is suspected to be due to the degradation of coffee compounds during the roasting step. Due to the high toxicity of these compounds, among which benzo[a]pyrene is known to be the most carcinogenic, their presence in the coffee, especially the coffee brew that is directly ingested by the consumer, is of prime importance. However, due to the low solubility of these compounds, their concentrations are expected to be rather low. As a consequence, reliable and sensitive analytical methods are required. The aim of this study was to develop a reliable and fast analytical procedure to determine these organic micropollutants in coffee brew samples. PAHs were retained on a 0.5 g polystyrene-divinylbenzene cartridge before being eluted by a mixture of methanol/tetrahydrofuran (10:90 v/v), concentrated, and directly analyzed by reversed-phase high-performance liquid chromatography coupled to a fluorescence detector. Application to the determination of PAHs in several coffee brew samples is also given, with mean estimated concentrations in the range of 0-100 ng L(-1) for suspected benzo[b]fluoranthene and benzo[a]pyrene, whereas no fluoranthene could be detected. Tentative identification was made on the basis of UV spectra. However, identification of the suspected traces of PAHs could not be achieved due to matrix effects, so that the presence of coeluting compounds may not be excluded.     

Investigation of sample treatment steps for the analysis of polycyclic aromatic hydrocarbons in ground coffee

Sample treatment procedures were tested for the determination of polycyclic aromatic hydrocarbons (PAHs) in ground coffee. Pressurized liquid extraction (PLE), under different conditions, was combined with several cleanup methods, namely in situ purification, C18-silica solid-phase extraction (SPE), silica SPE, acid digestion, and alkaline saponification. Soxhlet extraction and direct alkaline saponification were also tested. Best results were obtained using PLE with hexane/acetone 50:50 (v/v) under 150 degrees C. Alkaline saponification followed by cyclohexane extraction and silica SPE was required to eliminate interferent compounds. Finally, 11 PAHs could be quantified in ground coffee with limits of detection in the range of 0.11-0.18 microg kg(-1). Application to ground Arabica coffee lots from Colombia revealed the presence of several PAHs, giving an overall toxicity equivalence in the range of 0.16-0.87 microg kg(-1). PAH identification was performed using both high-performance liquid chromatography-diode array detection and gas chromatography coupled to mass spectrometry.     

Predicting Rice Yield Under Salinity Stress Using K/Na Ratio Variable in Plant Tissue

Estimation of yield reduction in crop caused by the salinity stress is mostly based on variations of soil electrical conductivity and the severity of water stress. Crop response curves to salinity were developed without considering ion toxicity and nutritional imbalance in the plant. The objective of this study was to explore the possibility of using the ratio of the concentration of potassium by sodium in rice leaf (leaf-K/Na) to predict yield under the salinity stress. The rice (Oryza sativa L.) yield under fresh and saline condition and the leaf-K/Na related database was created. Data were collected from consecutive three seasons of a field experiment in the Africa Rice Center experimental farm in Senegal (16° 11? N, 16° 15?W). We studied the relationship between the relative yield (Y_r), a ratio of yield under the salinity stress to the potential yield and the leaf-K/Na (x). Furthermore, we did regression analyses and F-test to determine the best fitting function. Results indicate that the exponential function [i.e. Y_r = 100 exp (-b x)] was the best fitting model with the lowest root mean square error (9.683) and the highest R² value (0.90). Example applications on independent data from published papers showed relatively good predictions, suggesting that the model can be used to predict rice yield in saline soils.     

The mobility of the trace metals copper,zinc, lead,cobalt, and nickel in tropical estuarine sediments,Ebrie Lagoon,Côte d’Ivoire

Journal of Soils and Sediments - Trace metals accumulate in the food web and can pose high risks to human health and aquatic biota. We investigated seasonal and spatial variations of Cu, Zn, Pb,...