Effects of a kaolin-based particle film on oviposition and feeding of gypsy moth (Lep., Lymantriidae) and forest tent caterpillar (Lep., Lasiocampidae) in the laboratory

Abstract:  In the laboratory we investigated a kaolin-based crop protectant, Surround^® WP, that was mixed in a spray carrier (94% water, 2% methanol, 4% Triton X100) and applied as particle film against gypsy moth Lymantria dispar (L.) and forest tent caterpillar Malacosoma disstria Hubner. Paired-choice feeding tests showed that gypsy moth larvae were significantly (P < 0.05) less disposed to feed on red oak Quercus rubrus L. treated with high concentrations (60 and 120 g/l carrier) of kaolin than on untreated foliage. There was no significant difference (P > 0.05) between gypsy moth's consumption of kaolin-treated and untreated red oak when given a single food choice, but the adults were less inclined to oviposit on the kaolin-treated surfaces than on controls. However, no kaolin treatment completely deterred gypsy moth feeding or oviposition. Kaolin particle film did not influence forest tent caterpillar feeding and there were insufficient data to evaluate the effect of kaolin on the species' oviposition. The spray carrier did not increase the efficacy of the kaolin, but as an independent, albeit impractical treatment it constrained feeding by both insect species but did not affect gypsy moth oviposition. These initial laboratory findings suggest that applying kaolin-based particle film to forests would present significant challenges; but if these could be surmounted, the technique might assist in the management of gypsy moth but not likely in that of forest tent caterpillar.     

Making Forest of Bliss: The Film, the Book, the DVD, and the Breakthrough

Robert Gardner's and Àkos Östör's Making of Forest of Bliss (2002) is a combination book and DVD that contains eight teaching tools for better understanding Gardner's celebrated film Forest of Bliss. After the film was shot in 1985, filmmaker Gardner and anthropologist Östör recorded a conversation about each image and sound of the film while they screened it again in 1987, and remembered their filmmaking process on location in Benares, India. The feature length (89 minute) documentary about death ritual, reincarnation, the sacred Ganges River, and the very atmosphere of Benares is included as DVD, as are teaching tools such as frame grabs (still images from the film), a mathematically precise shot list, bibliography, important criticism and essays about the film, and the featured in-depth conversation between filmmaker Gardner and anthropological advisor Östör. This essay articulates the unique breakthroughs in pedagogy, cross-cultural studies, and multidisciplinary analysis such hybrid technology provides.     

生物降解地膜应用与地膜残留污染防控

地膜是农业生产中重要的生产资料之一,过去30多年,地膜用量和农作物覆膜面积一直稳定增长,2014年地膜用量达到了144万t,覆膜面积超过1 800万hm~2,该技术对保障我国农产品安全供给作出了重大贡献。与此同时,地膜残留污染问题越来越严重,一些农田的地膜残留量超过250 kg/hm~2,在我国西北的局部区域,地膜残留已经对农田土壤、作物生长发育、农事作业等造成严重影响和危害。生物降解地膜成为替代普通PE地膜、解决地膜残留污染的一种有效措施和手段,目前生物降解地膜正处于产品研发和评价试验的关键阶段,部分生物降解地膜产品在马铃薯、花生、烟草生产上显示出良好的效果,但总体上还面临巨大挑战,主要包括需要进一步提高地膜产品质量,提高地膜产品破裂和降解可控性,改善地膜的增温保墒能力,实现满足农作物对地膜覆盖功能的要求;此外,需要降低生物降解地膜综合成本,促进生物降解地膜规模化应用。总体上,随着技术进步和农业生产环境的变化,生物降解地膜应用将具有良好的前景。     

Immobilization of glucose oxidase on thin-film gold electrodes produced by magnetron sputtering and their application in an electrochemical biosensor

An electrochemical biosensor is described consisting of a thin-layer gold film electrode prepared by cathodic sputtering using a poly(vinyl chloride) sheet as substrate, with voltammetric behaviour comparable to that of conventional polycrystalline gold electrodes, coated with the hydrolysed copolymer hydroxyethyl methacrylate-co-methyl methacrylate onto which glucose oxidase was immobilized. The mechanical properties of the plastic foil substrate permit easy construction of circular-shaped electrodes which were employed as working electrodes for batch injection analysis. The electrochemical biosensor fabrication is inexpensive and can be used as disposable enzyme sensor for the detection of hydrogen peroxide. The biosensor was tested for the determination of glucose in serum and a good correlation was obtained with the measurement using the electrochemical and the spectrophotometric methods.     

A single-use luciferase-based mercury biosensor using Escherichia coli HB101 immobilized in a latex copolymer film

A single-use Hg(II) patch biosensor has been developed consisting of 1.25-cm diameter patches of two acrylic vinyl acetate copolymer layers coated on polyester. The top layer copolymer was 47 μm thick whereas the bottom layer of copolymer plus E. coli cells was 30 μm thick. The immobilized E. coli HB101 cells harbored a mer-lux plasmid construct and produced a detectable light signal when exposed to Hg(II). The immobilized-cell Hg(II) biosensor had a sensitivity similar to that of suspended cells but a significantly larger detection range. The levels of mercury detected by the patches ranged from 0.1 nM to 10 000 nM HgCl₂ in pyruvate buffer, and luciferase induction as a function of Hg(II) concentration was sigmoidal. Luciferase activity was detected in immobilized cells for more than 78 h after exposure of the cells to HgCl₂. Addition of 1 mM D-cysteine to the pyruvate buffer increased luciferase induction more than 100-fold in the immobilized cell patches and 3.5-fold in a comparable suspension culture. The copolymer patches with immobilized cells were stable at −20°C for at least 3 months, and the Hg(II)-induced luciferase activity after storage was similar to that of samples assayed immediately after coating. Patches stored desiccated at room temperature for 2 weeks showed lower mercury-induced luciferase activity when compared to freshly prepared patches, but they still had a considerable detection range of 1 to 10 000 nM HgCl₂. Received 05 November 1998/ Accepted in revised form 08 April 1999     

New structural–optical effect in LiF–Li2B4O7 thin-film structures in the crystallization

The effect of optical radiation during the phase transition from the amorphous to the crystalline state of matter was investigated for the first time. The results were obtained on nanoscale films of (LiF)_x(Li₂B₄O₇)_1-x compositions by sputtering on cold Ni substrates. The starting materials for films were chosen due to their wide use for tissue-equivalent ionizing radiation dosimetry. It is shown that the detected thermoluminescence effect is sensitive to the thickness of the films. The paper compares the results of these studies with the study of the thermoluminescence characteristics of films irradiated by an M-30 microtron with bremsstrahlung radiation with a maximum energy of 6 MeV. The absorbed radiation dose was 1 kGy. Differences in the luminescence characteristics of irradiated and nonirradiated films were revealed. The nature of the demonstrated structural–optical effect is discussed.     

IR investigation on dehydrophenylalanine containing model peptides in helical conformation deposited on a crystal surface

Fourier transform ir spectra have been recorded for three 3₁₀‐helical and one α‐helical pentapeptides containing dehydrophenylalanine, in a thin solid film, in order to find marker bands for various secondary structures encountered in peptides containing dehydroaminoacids. The peptide solutions were deposited and dried as thin film on zinc selenide crystal surface. This convenient sampling method has provided reliable estimates of peptide secondary structure in solid state. Detailed vibrational assignments in the spectral region between 1200–1700 cm⁻¹ are reported. In this region, peptide amide I, II, and III vibrations occur. Spectra–structure correlation has been presented based on the amide modes. Comparison of the ir spectra with available crystal structure data provides qualitative support for assignments of ir bands to 3₁₀‐helical structure and α‐helical structure in dehydrophenylalanine containing pentapeptides. Band frequency assignments for 3₁₀‐helical conformation are consistent for all three peptides. All the assignments agree closely with the theoretical predictions. The spectral differences between 3₁₀‐helical peptides and the α‐helical peptide have been highlighted. These findings demonstrate that a method based on ir spectroscopy can be developed for a useful approximation of three‐dimensional structure of dehydropeptides in solid state. © 1999 John Wiley & Sons, Inc. Biopoly 50: 595–601, 1999     

The effects of grooming on a copper ablative coating: a six year study

More than 90% of US Navy Ships are coated with copper ablative paint. These ships may spend long periods of time pier-side, which makes them vulnerable to fouling. Hull grooming has been proposed as a means of maintaining the coatings in an operational condition. This study investigated the effect of grooming on a copper ablative coating exposed statically for six years. Grooming was performed weekly or monthly with controls left ungroomed. The fouling community was visually assessed, dry film thickness measurements were taken to monitor coating loss, and the copper leaching rates were measured. It was found that weekly and monthly groomed surfaces reduced fouling, and the ungroomed surfaces became fully fouled. Coating loss was similar for weekly, monthly and ungroomed surfaces. The results suggest that grooming is a viable method for maintaining copper ablative coatings in a fouling-free condition without adverse increases in the total copper output.     

Thiophene Rings Improve the Device Performance of Conjugated Polymers in Polymer Solar Cells with Thick Active Layers

Developing novel materials that tolerate thickness variations of the active layer is critical to further enhance the efficiency of polymer solar cells and enable large‐scale manufacturing. Presently, only a few polymers afford high efficiencies at active layer thickness exceeding 200 nm and molecular design guidelines for developing successful materials are lacking. It is thus highly desirable to identify structural factors that determine the performance of semiconducting conjugated polymers in thick‐film polymer solar cells. Here, it is demonstrated that thiophene rings, introduced in the backbone of alternating donor–acceptor type conjugated polymers, enhance the fill factor and overall efficiency for thick (>200 nm) solar cells. For a series of fluorinated semiconducting polymers derived from electron‐rich benzo[1,2‐b:4,5‐b′]dithiophene units and electron‐deficient 5,6‐difluorobenzo[2,1,3]thiazole units a steady increase of the fill factor and power conversion efficiency is found when introducing thiophene rings between the donor and acceptor units. The increased performance is a synergistic result of an enhanced hole mobility and a suppressed bimolecular charge recombination, which is attributed to more favorable polymer chain packing and finer phase separation.