Anomalously high geothermal flux near the South Pole.

Melting at the base of the Antarctic Ice Sheet influences ice dynamics and our ability to recover ancient climatic records from deep ice cores. Basal melt rates are affected by geothermal flux, one of the least constrained properties of the Antarctic continent. Estimates of Antarctic geothermal flux are typically regional in nature, derived from geological, magnetic or seismic data, or from sparse point measurements at ice core sites. We analyse ice-penetrating radar data upstream of South Pole revealing a ~100 km long and 50 km wide area where internal ice sheet layers converge with the bed. Ice sheet modelling shows that this englacial layer configuration requires basal melting of up to 6 ± 1 mm a-1 and a geothermal flux of 120 ± 20 mW m-2, more than double the values expected for this cratonic sector of East Antarctica. We suggest high heat producing Precambrian basement rocks and hydrothermal circulation along a major fault system cause this anomaly. We conclude that local geothermal flux anomalies could be more widespread in East Antarctica. Assessing their influence on subglacial hydrology and ice sheet dynamics requires new detailed geophysical observations, especially in candidate areas for deep ice core drilling and at the onset of major ice streams.

Blend chemistry and field attraction of commercial sex pheromone lures to grape berry moth (Lepidoptera: Tortricidae), and a nontarget tortricid in vineyards.

Anecdotal reports by scientists and growers suggested commercial sex pheromone lures were ineffective with monitoring field populations of grape berry moth, Paralobesia viteana (Clemens), in vineyards. This study addressed the need to evaluate commercial sex pheromone lures for chemical purity and efficacy of attracting grape berry moth and a nontarget tortricid, the sumac moth, Episumus argutanus (Clemens). The percentage of chemical components from a set of eight lures from each manufacturer was found using gas chromatography-mass spectrometry and confirmed by chemical standards. No lures adhered to the 9:1 blend of (Z)-9-dodecenyl acetate (Z9-12:Ac) to (Z)-11-tetradecenyl acetate (Z11-14:Ac), though Suterra (9.1:1), ISCA (5.7:1), and Trécé (5.4:1) lures were closest. The Trécé lures contained ≍98 µg Z9-12:Ac, which is 3-51 times more than the other lures. The Suterra and ISCA lures were loaded with ≍29 and 33 µg Z9-12:Ac, and the Alpha Scents lures only contained ≍2 µg Z9-12:Ac. An antagonistic impurity, (E)-9-tetradecenyl acetate (E9-12:Ac), was found in all manufacturer lures at concentrations from 3.2 to 4.8%. Field attraction studies were done in summer 2010, and again in 2011, to evaluate commercial lures for their potential to attract P. viteana and E. argutanus in the presence of lures from other manufacturers. Separate experiments were established in two vineyards in Augusta County, VA, one with open and the other with wooded surroundings. In field experiments, Suterra lures detected P. viteana most often, Trécé lures detected more E. argutanus, and ISCA lures detected P. viteana in the open vineyard the least, while Alpha Scents lures were least attractive to E. argutanus in both environments. Fewer P. viteana were captured in the wooded versus open vineyard, which may limit the potential for sex pheromone monitoring of P. viteana in wooded vineyards.

A technique using reusable components for hand-infesting cornstalks with European corn borer (Lepidoptera: Crambidae) larvae.

Field trials were conducted in 2005 and 2006 to evaluate the use of reusable wire nuts and nonreusable gelatin capsules for hand-infesting cornstalks with European corn borer, Ostrinia nubilalis (Hübner), (Lepidoptera: Crambidae) larvae. The reusable technique, which consists of a modified WingGard plastic wire connector (i.e., wire nut) as a containment device for larvae, was compared over three plant growth stages to a gelatin capsule technique. In 2005 and 2006, the wire nut technique resulted in significantly higher number of wire nuts still intact (i.e., undamaged, with or without a larva) on the stalk at 72 h after infestation compared with the gelatin capsule technique. In addition, the wire nut technique resulted in significantly higher number of tunnels per stalk compared with the gelatin capsule technique at all three corn growth stages during both years. In 2005, the mean +/- SEM number of tunnels per stalk was 0.53 +/- 0.03 in the wire nut technique compared with 0.13 +/- 0.03 tunnels per stalk in the gelatin capsule technique. In 2006, the mean number of tunnels per stalk was 0.45 +/- 0.03 in the wire nut technique compared with 0.08 +/- 0.02 tunnels per stalk in the gelatin capsule technique. In addition, the relative net precision in the wire-nut technique was approximately 2 times higher compared with the gelatin capsule technique.

European corn borer (Lepidoptera: Crambidae) infestation level and plant growth stage on whole-plant corn yield grown for silage in Virginia.

Field experiments were conducted in 2004 and 2005 to determine the effect of different levels of hand-infested third instar European corn borer, Ostrinia nubilalis (Hiibner) (Lepidoptera: Crambidae), on whole-plant yield and plant growth stage in corn, Zea mays L., grown for silage. In 2004 and 2005, European corn borer infestation level had a significant negative impact on whole-plant yield (grams of dry matter per plant) with increasing infestation; however, whole-plant yield was not significantly affected by plant growth stage in either year. In 2004, the six larvae per plant treatment caused the greatest percentage of reduction (23.4%) in mean (+/-SEM) whole-plant yield (258.5 +/- 21.0 g dry matter per plant) compared with the Bacillus thuringiensis (Bt) CrylAb control (337.3 +/- 11.1 g dry matter per plant). In 2005, the five larvae per plant treatment caused the greatest percentage of reduction (8.3%) in mean whole-plant yield (282.3 +/- 10.8 g dry matter per plant) compared with the Bt CrylAb control (307.8 +/- 8.3 g dry matter per plant). The relationship between mean whole-plant yield and European corn borer larvae infestation level from the pooled data of both years was described well by using an exponential decay model (r2 = 0.84, P = 0.0038). The economic injury level for silage corn was estimated to be approximately 73% higher than for corn grown for grain based on similar control costs and crop values. In addition, plant growth stage and European corn borer infestation level had no effect on percentage of acid detergent fiber, neutral detergent fiber, and crude protein values in either year of the study.

Anticipation of moving stimuli by the retina.

A flash of light evokes neural activity in the brain with a delay of 30-100 milliseconds, much of which is due to the slow process of visual transduction in photoreceptors. A moving object can cover a considerable distance in this time, and should therefore be seen noticeably behind its actual location. As this conflicts with everyday experience, it has been suggested that the visual cortex uses the delayed visual data from the eye to extrapolate the trajectory of a moving object, so that it is perceived at its actual location. Here we report that such anticipation of moving stimuli begins in the retina. A moving bar elicits a moving wave of spiking activity in the population of retinal ganglion cells. Rather than lagging behind the visual image, the population activity travels near the leading edge of the moving bar. This response is observed over a wide range of speeds and apparently compensates for the visual response latency. We show how this anticipation follows from known mechanisms of retinal processing.

Erythropoietin assay by hemagglutination-inhibition.

The immunochemical assay (HAI) for erythropoietin is accurate enough to detect small quantities and sensitive enough to demonstrate consistently and quantitatively the presence of erythropoietin in serum and urine. It will be the purpose of this report to describe in detail the procedure for the assay, the usefulness and value of erythropoietin testing in the clinical laboratory. The relationship of erythropoietin levels in serum and urine in the classification of diseases of the red blood cells are discussed. There is presently no other method available for the measurement of erythropoietin that permits the detection of extremely small differences, sensitive enough to demonstrate consistently and quantitatively the presence of small amounts of erythropoietin.