First report of naturally acquired clinical sarcocystosis in a pig breeding stock

A two-year-old Large White boar from a pig breeding stock in an indoor farm in Switzerland presented anorexia, reduced general condition and fever. Despite antibiotic and anti-inflammatory treatment, the boar developed severe dyspnoea and cyanosis, and died after 4 days. At necropsy, no gross lesions were observed. Histopathologically, multifocal degeneration and necrosis of myocardial fibers with interstitial edema, severe multifocal non-suppurative myocarditis and hepatitis, and non-suppurative interstitial nephritis were observed. In heart samples, groups of organisms resembling apicomplexan tachyzoites were seen associated with the lesions. A PCR using the primers COC1-COC2 that target a conserved region of the small-subunit rRNA gene of Apicomplexa was performed with DNA from paraffin-embedded tissues. An amplification product of about 350 bp was obtained from heart samples. A sequence analysis showed 100% identities with GenBank sequences reported for Sarcocystis miescheriana. The histopathological observations and molecular findings in combination with the clinical signs, and absence of other pathologic agents highly suggested that an acute infection with S. miescheriana was the cause of death in this boar. To our knowledge, this the first report of fatal acute sarcocystosis after natural infection in a pig breeding herd.     

First report of the Q biotype of <Emphasis Type="Italic">Bemisia tabaci</Emphasis> in Argentina and Uruguay

Bemisia tabaci adults were collected from pepper and melon at different commercial production greenhouses in Argentina and Uruguay. The biotype status of adults was then established using cytochrome oxidase I gene (mtCOI) as molecular marker. Only the Q biotype was found on all plants sampled. This is the first report of the Q biotype in Argentina and Uruguay.     

The use of biomarkers to assess the health of aquatic ecosystems in Brazil: a review

Organisms in polluted environments are typically exposed to a complex mixture of chemical contaminants. The great concern about the health of aquatic ecosystems has led to the increased use of biomarkers over the past years. The aim of this work was to review the papers published from 2000 to 2015, which used biomarkers to assess the health of aquatic ecosystems in Brazil. A research resulted in 99 eligible papers. More than 80% of studies were conducted in the states of São Paulo and Rio Grande do Sul. Approximately 63% of studies used fish as bioindicator, whereas the micronucleus test and biochemical analyses were the most used biomarkers. A multibiomarker approach was used by 60.6% of studies, while 39.4% used one single biomarker. Furthermore, 68% were field studies and more than 75% of these used control animals sampled at reference sites. A relationship between the biomarker responses and pollution was reported by 87% of studies; however, 43.4% of studies analyzed only one sampling period, limiting comparisons and comprehension about possible seasonal variations. This review evidenced some weak points in studies using biomarkers in Brazil, especially related to the lack of studies in two important biomes (the Pantanal and the Amazon Rainforest) and experimental designs (small sample size, sampling in one single period, use of one single biomarker). Thus, future studies should consider mainly the use of multiple biomarkers, greater sample size, seasonal sampling and water physicochemical parameters to better diagnose the health of aquatic ecosystems.     

Physiological and pharmacokinetic responses in neotropical Piaractus mesopotamicus to the essential oil from Lippia sidoides (Verbenaceae) as an anesthetic

International Aquatic Research - The goal of the study was to evaluate Lippia sidoides essential oil as an anesthetic for the tropical fish pacu Piaractus mesopotamicus. The physiological and...     

The contribution of maize cropping in the Midwest USA to global warming: A regional estimate

Agricultural soils emit about 50% of the global flux of N₂O attributable to human influence, mostly in response to nitrogen fertilizer use. Recent evidence that the relationship between N₂O fluxes and N-fertilizer additions to cereal maize are non-linear provides an opportunity to estimate regional N₂O fluxes based on estimates of N application rates rather than as a simple percentage of N inputs as used by the Intergovernmental Panel on Climate Change (IPCC). We combined a simple empirical model of N₂O production with the SOCRATES soil carbon dynamics model to estimate N₂O and other sources of Global Warming Potential (GWP) from cereal maize across 19,000 cropland polygons in the North Central Region (NCR) of the US over the period 1964-2005. Results indicate that the loading of greenhouse gases to the atmosphere from cereal maize production in the NCR was 1.7 Gt CO₂e, with an average 268 t CO₂e produced per tonne of grain. From 1970 until 2005, GHG emissions per unit product declined on average by 2.8 t CO₂e ha⁻¹ annum⁻¹, coinciding with a stabilisation in N application rate and consistent increases in grain yield from the mid-1970’s. Nitrous oxide production from N fertilizer inputs represented 59% of these emissions, soil C decline (0-30 cm) represented 11% of total emissions, with the remaining 30% (517 Mt) from the combustion of fuel associated with farm operations. Of the 126 Mt of N fertilizer applied to cereal maize from 1964 to 2005, we estimate that 2.2 Mt N was emitted as N₂O when using a non-linear response model, equivalent to 1.75% of the applied N.     

Subfield crop yields and temporal stability in thousands of US Midwest fields

Understanding subfield crop yields and temporal stability is critical to better manage crops. Several algorithms have proposed to study within-field temporal variability but they were mostly limited to few fields. In this study, a large dataset composed of 5520 yield maps from 768 fields provided by farmers was used to investigate the influence of subfield yield distribution skewness on temporal variability. The data are used to test two intuitive algorithms for mapping stability: one based on standard deviation and the second based on pixel ranking and percentiles. The analysis of yield monitor data indicates that yield distribution is asymmetric, and it tends to be negatively skewed (p?<?0.05) for all of the four crops analyzed, meaning that low yielding areas are lower in frequency but cover a larger range of low values. The mean yield difference between the pixels classified as high-and-stable and the pixels classified as low-and-stable was 1.04 Mg ha^?1 for maize, 0.39 Mg ha^?1 for cotton, 0.34 Mg ha^?1 for soybean, and 0.59 Mg ha^?1 for wheat. The yield of the unstable zones was similar to the pixels classified as low-and-stable by the standard deviation algorithm, whereas the two-way outlier algorithm did not exhibit this bias. Furthermore, the increase in the number years of yield maps available induced a modest but significant increase in the certainty of stability classifications, and the proportion of unstable pixels increased with the precipitation heterogeneity between the years comprising the yield maps.

     

Tissue-Specific Variations of Esterase Activities in the Tadpoles and Adults of Pseudis paradoxa (Anura: Hylidae)

Water, Air, &; Soil Pollution - We determined basal levels of cholinesterase (ChE) and carboxylesterase (CbEs; two substrates: α-naphthyl acetate and 4-nitrophenylvalerate) in different...