Evaluation of Current Tarnished Plant Bug (Hemiptera: Miridae) Thresholds in Transgenic MON 88702 Cotton Expressing the Bt Cry51Aa2.834_16 Trait.

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is an important pest of cotton in many areas of the southern United States. An experiment was conducted at two locations in Mississippi during 2016 and 2017 to evaluate action thresholds for tarnished plant bug on a novel Bacillus thuringiensis cotton that expresses the Cry51Aa2.834_16 toxin. Treatments included the current action threshold, a 2× threshold, and treatments where insecticides were only applied during the early season (preflower) or only during late season (during flowering) based on the current action thresholds. These were compared to an untreated control and a weekly insecticide use regime that received weekly insecticide sprays. All treatments were imposed on both Bt Cry1Aa2.834_16 cotton and a nontraited cotton. The Bt Cry1Aa2.834_16 trait reduced the number of tarnished plant bugs and injury, and improved yields compared to nontraited cotton. For all spray treatments except the weekly insecticide use regime, yields were greater for the Bt Cry51Aa2.834_16 cotton than the nontraited cotton. In terms of thresholds, Bt Cry1Aa2.834_16 cotton sprayed based on current action thresholds resulted in similar yields to the weekly insecticide use regime of both cotton types. In contrast, the 2× threshold resulted in lower yields than the current threshold for both cotton types. Though thresholds intermediate to the currently recommended action threshold and the 2× threshold were not tested, these data suggest that currently recommended action thresholds appear appropriate for Bt Cry51Aa2.834_16 cotton. These results suggest that this trait will be an important component of current IPM programs in cotton where tarnished plant bug is an important pest.

Trace Metals in Soot and PM2.5 from Heavy-Fuel-Oil Combustion in a Marine Engine.

Heavy fuel oil (HFO) particulate matter (PM) emitted by marine engines is known to contain toxic heavy metals, including vanadium (V) and nickel (Ni). The toxicity of such metals will depend on the their chemical state, size distribution, and mixing state. Using online soot-particle aerosol mass spectrometry (SP-AMS), we quantified the mass of five metals (V, Ni, Fe, Na, and Ba) in HFO-PM soot particles produced by a marine diesel research engine. The in-soot metal concentrations were compared to in-PM2.5 measurements by inductively coupled plasma-optical emission spectroscopy (ICP-OES). We found that <3% of total PM2.5 metals was associated with soot particles, which may still be sufficient to influence in-cylinder soot burnout rates. Since these metals were most likely present as oxides, whereas studies on lower-temperature boilers report a predominance of sulfates, this result implies that the toxicity of HFO PM depends on its combustion conditions. Finally, we observed a 4-to-25-fold enhancement in the ratio V:Ni in soot particles versus PM2.5, indicating an enrichment of V in soot due to its lower nucleation/condensation temperature. As this enrichment mechanism is not dependent on soot formation, V is expected to be generally enriched within smaller HFO-PM particles from marine engines, enhancing its toxicity.

Revising the hygroscopicity of inorganic sea salt particles.

Sea spray is one of the largest natural aerosol sources and plays an important role in the Earth's radiative budget. These particles are inherently hygroscopic, that is, they take-up moisture from the air, which affects the extent to which they interact with solar radiation. We demonstrate that the hygroscopic growth of inorganic sea salt is 8-15% lower than pure sodium chloride, most likely due to the presence of hydrates. We observe an increase in hygroscopic growth with decreasing particle size (for particle diameters <150 nm) that is independent of the particle generation method. We vary the hygroscopic growth of the inorganic sea salt within a general circulation model and show that a reduced hygroscopicity leads to a reduction in aerosol-radiation interactions, manifested by a latitudinal-dependent reduction of the aerosol optical depth by up to 15%, while cloud-related parameters are unaffected. We propose that a value of κs=1.1 (at RH=90%) is used to represent the hygroscopicity of inorganic sea salt particles in numerical models.

[Tamponade and total parenteral nutrition by central venous catheter]. / Tamponnade et alimentation parentérale totale sur cathéter veineux central.

Various complications are associated with the use of central venous catheters for total parenteral nutrition; cardiac tamponade is one of the most severe. Four cases are reported of cardiac tamponade during total parenteral nutrition: three of them were related to cardiac perforation by the tip of the catheter, placed in the right atrium; the fourth case may have been due to cardiac perforation or to an extraintestinal complication of inflammatory bowel disease. Hydropericardium may manifest itself soon after the catheter is inserted or, more usually, some days or weeks later. Immediate diagnosis is mandatory: a sudden and unexpected deterioration in a patient receiving total parenteral nutrition through a central venous catheter, with shock, heart failure, cyanosis, congestion of neck veins should arouse suspicion of hydropericardium. Long term undernutrition, a small atrophic heart, steroid treatment may also contribute to cardiac perforation. Immediate aspiration of the hydropericardium may be life-saving: if possible, the fluid is evacuated through the catheter while still in place; otherwise, pericardiocentesis must be immediately performed. Such complications can be prevented by: the use of flexible silicone or polyurethane catheters instead of rigid polyethylene catheters, especially for long term use; a correct positioning of the catheter tip in the superior vena cava in its extrapericardial sector, as it can be checked by chest X-ray. This examination, with opacification of the catheter with contrast medium, must be repeated because of the possibility of secondary displacement of the catheter.

[Voluntary chloralose poisoning]. / Intoxication volontaire par le chloralose.

The authors report 114 cases of acute poisoning by rodenticides (chloralose). The clinical symptoms associate coma, myoclonic jerks and bronchorrhea. Metabolic acidosis is a common finding. Despite the initial gravity, the prognosis of chloralose intoxication is excellent, provided that a symptomatic treatment is instituted early.