Field Studies of the Co-Occlusion Strategy with a Genetically Altered Isolate of the Autographa californica Nuclear Polyhedrosis Virus

The first field study of a genetically altered virus in the United States was performed with an isolate of the Autographa californica nuclear polyhedrosis virus (AcMNPV), which lacks a polyhedrin gene. In the first year of the study, three applications of 7.4 × 1011 AcMNPV polyhedra containing 48% genetically altered and 52% wild-type virus particles (co-occluded) were made on a O.1-ha circular plot of cabbage plants. The application area was surrounded by a 0.7-ha circular buffer zone. Before each application, the plants in the application area were infested with 4,500 third-ins tar Trichoplusia ni (Hübner) larvae. After each application, 100% of the T. ni test larvae sampled 5 d after infection were infected with AcMNPV and produced progeny polyhedra containing an average of 42 ± 17.6% genetically altered virus particles. At the end of the 1st yr, the progeny polyhedra population in the application area was estimated at 1.6 × 1013 polyhedra. In the 2nd yr, the application and buffer sites were replanted with cabbage plants. At four times during the growing season, the plants were seeded with T. ni larvae or eggs. Less than 2% of the test larvae became infected with AcMNPV. Polyhedra were extracted from soil samples collected in the application and buffer areas. Using neonate larval bioassays with the soil extracts, it was estimated that the soil in the application and buffer areas contained an average of 1,652 ± 3,370 and 832 ± 2,539 biologically active polyhedra per gram dry weight, respectively. Seventy-five larvae infected with polyhedra extracted from application area soil samples produced progeny polyhedra containing a mean of 9 ± 19% genetically altered virus particles. In the 3rd yr, the application area soil samples contained an average of 1,671 ± 3,274 biologically active polyhedra per gram dry weight. Eighty-four progeny polyhedral samples contained a mean of 6 ± 14% genetically altered virus particles. The co-occlusion strategy did not alter the environmental persistence of the polyhedra containing both wild-type and polyhedrin-minus virus particles. However, the data show a decline in the percent of polyhedrin-minus particles in the polyhedra and demonstrate that the persistence of a polyhedrin-minus virus in a cycling virus population is limited by the co-occlusion process. The environmentally desirable attributes of using the co-occlusion process for genetically enhanced baculovirus pesticides and possible problems are discusse

Enduring Effects on Knowledge

The domain of knowledge we have been able to examine by secondary analysis contained 250 discrete items of information requested in American national surveys between 1949 and 1971. Since the influence of education on each item (with a few exceptions) is examined separately for each of four age cohorts, our fundamental findings involve about a thousand sets of comparisons of knowledge among several educational levels. How to present such massive evidence creates a severe problem. Compression and condensation are essential if the reader is not to become submerged and finally drown in the ocean of data. In a letter to the New York Times, one poor soul who had waded through the Coleman report, survived then to read Jencks\u27s work, only finally to confront the recent multi-volume report of the International Association for the Evaluation of Educational Achievement, put the problem poignantly: The voice of reason is overwhelmed by the vast array of codified data (9 June, 1973, p. 32)

Physical Electronics

Contains reports on three research projects

Physical Electronics

Contains reports on four research projects

Coulomb Blockade Regime of a Single-Wall Nanotube

A model of carbon nanotube at half filling is studied. The Coulomb interaction is assumed to be unscreened. It is shown that this allows to develop the adiabatic approximation which leads to considerable simplifications in calculations of the excitation spectrum. We give a detailed analysis of the spectrum and the phase diagram at half filling and discuss effects of small doping. At small doping several phases develop strong superconducting fluctuations corresponding to various types of pairing

Rates of Urinary Toxin Excretion in Unprotected Steers Fed \u3cem\u3eLeucaena leucocephala\u3c/em\u3e

Leucaena (Leucaena leucocephala) is a productive, nutritious, leguminous forage tree with high capacity for ruminant live weight gain. The plant does however contain the non-protein amino acid mimosine which is degraded within the rumen to 3-hydroxy-4(1H)-pyridone (3,4-DHP) with potential to cause adverse effects on animal health and production. Stock can be protected via rumen inoculation with the bacterium Synergistes jonesii, which is capable of degrading the toxin. However surveys have demonstrated sub-clinical toxicity is persisting in Queensland herds (Dalzell et al. 2012). Currently, testing for toxicity involves analysis of urine samples using high performance liquid chromatography (HPLC). A colorimetric urine test protocol has also been developed with the aim of providing a robust and reliable means for routinely testing herds (Graham et al. 2013). A significant problem affecting interpretation of the results from either method is the high variation in the concentrations of toxins excreted among animals on similar diets and by individual animals over time (Dalzell et al. 2012). Factors such as feed intake, water consumption, urine volume, as well as timing of sampling may be the cause of this variation. This research investigated the effect of sample timing by measuring the time taken for mimosine and its breakdown products, to present in the urine following the introduction of leucaena to the ration of cattle naïve to the plant

System for the measurement of ultra-low stray light levels

An apparatus is described for measuring the effectiveness of stray light suppression light shields and baffle arrangements used in optical space experiments and large space telescopes. The light shield and baffle arrangement and a telescope model are contained in a vacuum chamber. A source of short, high-powered light energy illuminates portions of the light shield and baffle arrangement and reflects a portion of same to a photomultiplier tube by virtue of multipath scattering. The resulting signal is transferred to time-channel electronics timed by the firing of the high energy light source allowing time discrimination of the signal thereby enabling the light scattered and suppressed by the model to be distinguished from the walls and holders around the apparatus

Detection of Toxicity in Ruminants Consuming Leucaena (\u3cem\u3eLeucaena leucocephala\u3c/em\u3e) Using a Urine Colorimetric Test

Leucaena (Leucaena leucocephala), a productive leguminous shrub for feeding ruminant livestock, contains the toxic amino acid, mimosine which post- ingestion is converted to 3,4-DHP and 2,3-DHP, isomers of dihydroxy-pyridone. While DHP generally does not exhibit acute toxic symptoms, it has been suggested that it is an appetite suppressant that reduces animal live weight gain (Jones 1994). With no observable symptoms, subclinical toxicity is difficult to detect (Phaikaew et al. 2012). In 1982 the DHP-degrading rumen bacterium named Synergistes jonesii was introduced into Australia as a potential solution to DHP toxicity as it spreads easily throughout cattle herds grazing leucaena (Jones 1994). However, toxicity events reported since the 2003 drought suggest that the toxicity status of herds, previously understood as being protected, may have changed. This may be the result of loss of effective S. jonesii bacteria from the rumen. Widespread subclinical leucaena toxicity has since been confirmed representing a significant economic threat to the beef industry (Dalzell et al. 2012). At present the testing for toxicity requires a sophisticated chemical analysis of urine samples using high performance liquid chromatography (HPLC). Producers, however, require a robust and reliable means to routinely test for toxicity in their herds. A colorimetric urine test protocol is available based on the colour reaction of mimosine and DHP with FeCl3 solution (Jones 1997). When this simpler colorimetric test has been used under a wide range of conditions false negatives have been reported. The aim of this study was to improve the reliability of the FeCL3 urine colour test

Gene editing restores dystrophin expression in a canine model of Duchenne muscular dystrophy

Mutations in the gene encoding dystrophin, a protein that maintains muscle integrity and function, cause Duchenne muscular dystrophy (DMD). The deltaE50-MD dog model of DMD harbors a mutation corresponding to a mutational “hotspot” in the human DMD gene. We used adeno-associated viruses to deliver CRISPR gene editing components to four dogs and examined dystrophin protein expression 6 weeks after intramuscular delivery (n = 2) or 8 weeks after systemic delivery (n = 2). After systemic delivery in skeletal muscle, dystrophin was restored to levels ranging from 3 to 90% of normal, depending on muscle type. In cardiac muscle, dystrophin levels in the dog receiving the highest dose reached 92% of normal. The treated dogs also showed improved muscle histology. These large-animal data support the concept that, with further development, gene editing approaches may prove clinically useful for the treatment of DMD