DNA‐analysis to monitor fisheries and aquaculture: Too costly?

Evidence from DNA‐analysis is commonplace in human criminal investigations, and while it is increasingly being used in wildlife crime, to date, its application to control and enforcement activities in fisheries and aquaculture has only been sporadic. Contemporary DNA‐analysis tools are capable of addressing a broad range of compliance issues, species identification, mislabelling of fish products, determining the origin of catches and the farm of origin of aquaculture escapees. Such applications have the potential to ensure traceability along the fish product supply chain and to combat consumer fraud and Illegal, Unreported and Unregulated fishing. Nevertheless, DNA‐analysis is not yet used routinely in investigations into compliance with fisheries and aquaculture legislation. One potential reason for this is that DNA‐analysis techniques may have been regarded as too expensive. However, costs have plummeted over the past decade prompting us to objectively assess whether the costs associated with routine use of DNA‐analysis techniques for fisheries and aquaculture control and enforcement activities do constitute an impediment. Based on a number of recent fisheries and aquaculture compliance investigations that incorporated DNA‐analysis, our results indicate that the use of genetic analysis was justified and worthwhile in all cases examined. We therefore conclude that the costs associated with DNA‐analysis do not represent a barrier to the routine adoption of DNA‐analysis techniques in fisheries and aquaculture compliance investigations. Thus, control and enforcement agencies should be encouraged to use such techniques routinely.     

Cytokine mRNA profiles in pigs exposed prenatally and postnatally to Schistosoma japonicum

The pig is a natural host for Schistosoma japonicum and a useful animal model of human infection. The aim of the present study was to assess the differences between the cytokine profiles in prenatally or postnatally S. japonicum exposed pigs. Seven prenatally exposed pigs, 7 postnatally exposed pigs and 4 uninfected control pigs were compared 27 weeks post exposure. Variables included worm burdens, tissue egg counts, liver pathology and mRNA levels of IL-2, IL-4, IL-10, IL-12, TNF-alpha, TGF-beta1 and IFN-gamma in the liver and the caecum, assessed by RT-PCR. Infection intensity and level of septal fibrosis were significantly higher in the postnatal group compared to the prenatal group (P < 0.05). A significant increase of IL-4 (P < 0.01), IL-10 (P < 0.01), IL-12 (P < 0.01) and TNF-alpha (P < 0.05) mRNA level was also observed in the caecum of prenatally infected animals compared to the control group (P < 0.01). The prenatal group showed higher levels of TGF-beta1 in the liver compared with the postnatally infected group (P< 0.05) and the control group (P< 0.01). This suppressive immune response correlated with previously reported low hepatic pathogenesis in prenatally exposed pigs.     

Impact of plant cell wall network on biodegradation in soil: Role of lignin composition and phenolic acids in roots from 16 maize genotypes

Residue quality is a key factor governing biodegradation and the fate of C in soil. Most investigations of relationships existing between crop residue quality and soil decomposition have been based on determining the relative proportions of soluble, cellulose, hemicellulose and lignin components. However, cell wall cohesion is increased by tight interconnections between polysaccharides and lignin that involve cross-linking agents (phenolic acids). The aim of this study was to determine the role of lignin composition and phenolic acids on short- to medium-term decomposition of maize roots in soil. Sixteen maize genotypes, presenting a range of chemical characteristics related to root lignin and phenolic acids, were used. The main components were characterized by Van Soest (VS) extraction and cell wall acid hydrolysis, and the non-condensed Syringyl and Guaicyl lignin monomers, esterified phenolic acids and etherified phenolic acids were determined. Maize roots were then incubated in soil under controlled conditions (15 °C, −80 kPa moisture) for 796 days. Results showed that VS extraction over-estimated the structural hemicellulose content and that VS lignin was more recalcitrant than Klason lignin. The tremendous effect of cell wall chemical characteristics was shown by marked variations (almost two-fold differences in C mineralization), between the 16 maize roots. Decomposition was controlled by soluble residue components in the short term whereas lignin and the interconnections between cell wall polymers were important in the long-term. Notably the cell wall domain rich in non-condensed lignin and esterified phenolic acids was prone to decomposition whereas the presence of etherified ferulic acids seemed to hamper cell wall decomposition.     

Evaluating evaporation from field crops using airborne radiometry and ground-based meteorological data

Summary Airborne measurements of reflected solar and emitted thermal radiation were combined with ground-based measurements of incoming solar radiation, air temperature, windspeed, and vapor pressure to calculate instantaneous evaporation (LE) rates using a form of the Penman equation. Estimates of evaporation over cotton, wheat, and alfalfa fields were obtained on 5 days during a one-year period. A Bowen ratio apparatus, employed simultaneously, provided ground-based measurements of evaporation. Comparison of the airborne and ground techniques showed good agreement, with the greatest difference being about 12% for the instantaneous values. Estimates of daily (24 h) evaporation were made from the instantaneous data. On three of the five days, the difference between the two techniques was less than 8%, with the greatest difference being 25%. The results demonstrate that airborne remote sensing techniques can be used to obtain spatially distributed values of evaporation over agricultural fields.     

Live Transport of Striped Bass and Rainbow Trout Using a Hidrostal Pump

Immediate and delayed (96 h) mortality, descaling, and injury rates of striped bass Morone sax-atilis and rainbow trout Oncorhynchus mykiss that were inserted into the entrance (suction side) of a Hidrostal pump were compared to those of control fish that were inserted at the exit (pressure side). Comparisons were made in 158-paired trials of striped bass and 86 trials with rainbow trout. The Hidrostal pump had no significant effect on immediate or delayed (96 h) mortality. Immediate mortality for striped bass and rainbow trout averaged 0.1 and 0%, respectively, and delayed mortality averaged 2.9 and 0.1%, respectively. Mean scale loss after passage for striped bass and rainbow trout was low (0.2 and 1.0%, respectively). Frequency of injury to the head, eyes, skin, and tins of pumped striped bass averaged 1.9, 2.8, 1.9, and 18.7%, respectively, and those of rainbow trout averaged 2.3, 0, 2.4, and 3.1%. No significant relationships were detected between fish mortality and pump speed, injected fish density, and debris load. Results suggest that large Hidrostal pumps have the capacity to transport live striped bass and rainbow trout at high density (1-6 fish/L) with little mortality and body injury.     

Green tea polyphenol extract regulates the expression of genes involved in glucose uptake and insulin signaling in rats fed a high fructose diet

Green tea has antidiabetic, antiobesity, and anti-inflammatory activities in animal models, but the molecular mechanisms of these effects have not been fully understood. Quantitative real-time polymerase chain reaction (PCR) was used to investigate the relative expression levels and the effects of green tea (1 and 2 g solid extract/kg diet) on the expression of glucose transporter family genes (Glut1/Slc2a1, Glut2/Slc2a2, Glut3/Slc2a3, and Glut4/Slc2a4) and insulin signaling pathway genes (Ins1, Ins2, Insr, Irs1, Irs2, Akt1, Grb2, Igf1, Igf2, Igf1r, Igf2r, Gsk3b, Gys1, Pik3cb, Pik3r1, Shc1, and Sos1) in liver and muscle of rats fed a high-fructose diet known to induce insulin resistance and oxidative stress. Glut2 and Glut4 were the major Glut mRNAs in rat liver and muscle, respectively. Green tea extract (1 g) increased Glut1, Glut4, Gsk3b, and Irs2 mRNA levels by 110, 160, 30, and 60% in the liver, respectively, and increased Irs1 by 80% in the muscle. Green tea extract (2 g) increased Glut4, Gsk3b, and Pik3cb mRNA levels by 90, 30, and 30% but decreased Shc1 by 60% in the liver and increased Glut2, Glut4, Shc1, and Sos1 by 80, 40, 60, and 50% in the muscle. This study shows that green tea extract at 1 or 2 g/kg diet regulates gene expression in the glucose uptake and insulin signaling pathway in rats fed a fructose-rich diet.     

Induction of glucokinase mRNA by dietary phenolic compounds in rat liver cells in vitro

Diabetes and its complications, including oxidative stress, are major reasons for medical intervention and one of the most frequent causes of death in developed countries. Several lines of data suggest that the use of certain dietary polyphenolic compounds may alter glucose metabolism, thus decreasing the risk for type 2 diabetes. In this paper, we present the effect of phenolic acids (caffeic, chlorogenic, rosmarinic, and ferulic) and extracts from Smallanthus sonchifolius and Prunella vulgaris on glucose production in rat hepatocytes and on glucokinase, glucose-6-phosphatase, and phosphoenol-pyruvate carboxykinase mRNA expression in rat hepatoma Fao cells. The phenolics at 500 microM and after 1 h incubation lowered glucose production via both gluconeogenesis (10 mM alanine or dihydroxyacetone as precursors) and glycogenolysis compared with metformin. Most of the phenolics increased the level of glucokinase mRNA after 24 h in the same way as insulin (10(-7) M).