Canopy penetration and deposition of barrier sprays from electrostatic and conventional sprayers

An experimental study was conducted to investigate the usefulness of electrostatic and conventional sprayers for barrier applications. Two conventional and three electrostatic sprayers were used in the study. Usefulness of the sprayers was rated based on penetration of spray into and deposition onto 2 sides of leaves on natural vegetation. Bifenthrin (Talstar adulticide) was applied at labeled rate, fluorescent dye was added to the tank mix as tracer, and all sprayers applied the dye and insecticide at the same rate. The results indicated that sprayers producing larger droplets produced significantly higher deposition on vegetation in barrier applications than the sprayers producing smaller droplets. Sprayers with higher air velocity at the nozzle discharge proved significantly better for barrier sprays than the sprayers with lower air velocity. Electrostatic sprayers did not show any improvement in deposition on vegetation or in penetration into vegetation over the conventional sprayers. There was no difference in deposition between truck-mounted and backpack sprayers.

Attention Deficit Hyperactivity Disorder in Children: Comparative Efficacy of Traditional Chinese Medicine and Methylphenidate

Traditional Chinese medicine (TCM) is frequently used to treat attention deficit hyperactivity disorders (ADHD) in children in China. However, until now there has been no strong evidence to prove that TCM has better efficacy than western medicine. In this systematic study of 34 studies published in the Chinese literature, the effectiveness of TCM in treating ADHD in children was examined and compared with methylphenidate (MPH), which is widely used to treat ADHD. It was found that TCM may have equal or better effectiveness than MPH. However, the lack of high-quality clinical trials to support this conclusion means that it is not currently possible to recommend any particular kind of TCM preparation for treating ADHD in children.

Spray characterization of thermal fogging equipment typically used in vector control

Droplet size spectra from different sprayers used to generate insecticide-laden fogs for controlling flying insects were measured by a laser diffraction instrument and Teflon-coated slides. The objectives of this work were to present not only information on spray-system droplet size generated by different sprayers, but to compare methodologies by which other similar systems can be evaluated and give applicators sprayer-system performance data. Data from 45 replicated spray tests, comprising 11 sprayers and 5 pesticides, showed a wide range in the droplet size spectra produced. The volume median diameter measurements ranged from 2.6 to 75.5 microm for diesel-diluted sprays and from 27.9 to 59.9 microm for water-diluted sprays. Similarly, the percent volume <20 microm ranged between 12.0-100% and 8.5-30.7%, for diesel- and water-diluted sprays, respectively. The droplet sizes measured by the swinging slide and laser diffraction methods were not consistent. The information presented aids users in sprayer selection and operation to produce the specific droplet size spectra required for a particular application.

Influence of complex reagents on removal of chromium(VI) by zero-valent iron

The removal of Cr(VI) by zero-valent iron (Fe(0)) and the effect of three complex reagents, ethylenediaminetetraacetic acid (EDTA), NaF and 1,10-phenanthroline, on this reaction were investigated using batch reactors at pH values of 4, 5 and 6. The results indicate that the removal of Cr(VI) by Fe(0) is slow at pH 5.0 and that three complex reagents play different roles in the reaction. EDTA and NaF significantly enhance the reaction rate. The zero-order rate constants at pH 5.0 were 5.44 microM min(-1) in the presence of 4mM EDTA and 0.99 micrM min(-1) in the presence of 8 mM NaF, respectively, whereas that of control was only 0.33 micrM min(-1), even at pH=4.0. This enhancement is attributed to the formation of complex compounds between EDTA/NaF and reaction products, such as Cr(III) and Fe(III), which eliminate the precipitates of Cr(III), Fe(III) hydroxides and Cr(x)Fe(1-)(x)(OH)(3) and thus reduce surface passivation of Fe(0). In contrast, 1,10-phenanthroline, a complex reagent for Fe(II), dramatically decreases Cr(VI) reduction by Fe(0). At pH=4.0, the zero-order rate constant in the presence of 1mM of 1,10-phenanthroline was 0.02 micrM min(-1), decreasing by 99.7% and 93.9%, respectively, compared with the results in the presence and absence of EDTA. The results suggest that a pathway of the reduction of Cr(VI) to Cr(III) by Fe(0) may involve dissolution of Fe(0) to produce Fe(II), followed by reduction of Cr(VI) by Fe(II), rather than the direct reaction between Cr(VI) and Fe(0), in which Fe(0) transfers electrons to Cr(VI).

Different effects of electroacupuncture on esophageal motility and serum hormones in cats with esophagitis

We aim to investigate the effects of different electroacupuncture (EA) frequencies at ST-36 on esophageal motility, and to compare the effect of EA on serum gastrin (GAS), motilin (MTL), and vasoactive intestinal peptide (VIP). Thirty-two cats were divided into four equal groups. All animals underwent a Heller myotomy. After esophagitis developed two frequencies (2/15 Hz or 2/100 Hz) of EA were delivered into ST-36 (LEA group [low EA], HEA group [high EA]). Animals submitted to EA on a non-point region (EANP) were used as controls (LEANP group, HEANP group), respectively. Esophageal motility was continuously monitored. The lower esophageal sphincter pressure (LESP) decreased significantly after myotomy. The LESP decreased in both LEA and LEANP cats, and in LEA cats the pressure decrease was greater. The LESP increased in the HEA group, which was higher than that in the HEANP group (P < 0.05). High-frequency EA significantly increased the peak amplitude in esophageal peristalsis. There was a decrease in serum GAS and MTL in LEA cats compared with LEANP cats (both P < 0.01). GAS and MTL were higher in the HEA group than in the HEANP group (both P < 0.01). Serum VIP decreased in the HEA group (P < 0.05), while it increased in the LEA group (P < 0.05), compared with EANP groups, respectively. EA with a high frequency at ST-36 enhances LESP as well as esophageal motility, while EA with a low frequency decreases LESP. The effect of EA is acupoint-specific, and this effect appears to be mediated through GAS, MTL and VIP.

Characterization of truck-mounted atomization equipment typically used in vector control

The control of medically important arthropod vectors of human and animal disease is a high priority for both public health and military officials. Because droplet size of pesticide spray material is a critical factor affecting vector control applications, the droplet-size spectra produced by 11 sprayers and 3 spray formulations were evaluated. Droplet-size spectra were measured by a laser diffraction instrument, a hot-wire system, and rotating slides. There were considerable differences in the droplet-size spectra produced by the different sprayers tested. The volume median diameter (Dv0.5) for the water-based sprays ranged from 4.7 to 211 microm, depending on the sprayer, and the percent of spray volume contained in droplets less than 20 microm (%vol <20 microm) ranged between 0.5% and 98.9%. The Dv0.5 measurements for the oil-based sprays ranged from 9.4 to 125.3 microm and the %vol <20 microm ranged between 2.4% and 97.9%. The correlations between the Dv0.5 measured by the laser system (Dv0.5-laser) and the mass median diameter, Sauter diameter, and Dv0.5 measured by the AIMS probe were all significant. Generally, the slide Dv0.5s were numerically similar to the Dv0.5 from the laser system and the Sauter diameter from the Army Insecticide Measuring System probe. There was less consistent agreement between the % <32 microm values obtained from the slides and those from the other 2 samplers. The information presented can be used by applicators to select the sprayer that produces the droplet-size spectra needed for their particular application situation.

Newton's descent method for the determination of invariant tori

We formulate a fictitious-time-flow equation which drives an initial guess torus to a torus invariant under a given dynamics, provided such a torus exists. The method is general and applies in principle to continuous time flows and discrete time maps in arbitrary dimension and to both Hamiltonian and dissipative systems.

Transcriptional profile of shrimp white spot syndrome virus (WSSV) genes with DNA microarray

In an attempt to obtain the transcriptional profile of shrimp white spot syndrome virus (WSSV) genes, DNA microarray analysis was performed using amplified DNA fragments of the WSSV genome that covered most of the presumptive open reading frames (ORFs). Total RNAs were extracted from WSSV-infected crayfish (Cambarus clarkii) and reverse transcribed into cDNA and labeled with 32P-dATP. The DNA microarray detected 81.1% of the ORFs, and 47 of these were transcribed at 6 h post infection, suggesting they may be early genes. Some early genes were further confirmed by temporal analyses of gene transcription. Results in this study indicated the effectiveness of DNA microarray for discovering early viral genes.

Phase transition between nanostructures of titanate and titanium dioxides via simple wet-chemical reactions

Titanate nanofibers of various sizes and layered structure were prepared from inorganic titanium compounds by hydrothermal reactions. These fibers are different from "refractory" mineral substances because of their dimension, morphology, and significant large ratio of surface to volume, and, surprisingly, they are highly reactive. We found, for the first time, that phase transitions from the titanate nanostructures to TiO(2) polymorphs take place readily in simple wet-chemical processes at temperatures close to ambient temperature. In acidic aqueous dispersions, the fibers transform to anatase and rutile nanoparticles, respectively, but via different mechanisms. The titanate fibers prepared at lower hydrothermal temperatures transform to TiO(2) polymorphs at correspondingly lower temperatures because they are thinner, possess a larger surface area and more defects, and possess a less rigid crystal structure, resulting in lower stability. The transformations are reversible: in this case, the obtained TiO(2) nanocrystals reacted with concentrate NaOH solution, yielding hollow titanate nanotubes. Consequently, there are reversible transformation pathways for transitions between the titanates and the titanium dioxide polymorphs, via wet-chemical reactions at moderate temperatures. The significance of these findings arises because such transitions can be engineered to produce numerous delicate nanostructures under moderate conditions. To demonstrate the commercial application potential of these processes, we also report titanate and TiO(2) nanostructures synthesized directly from rutile minerals and industrial-grade rutiles by a new scheme of hydrometallurgical reactions.

Phase transition between nanostructures of titanate and titanium dioxides via simple wet-chemical reactions

Titanate nanofibers of various sizes and layered structure were prepared from inorganic titanium compounds by hydrothermal reactions. These fibers are different from "refractory" mineral substances because of their dimension, morphology, and significant large ratio of surface to volume, and, surprisingly, they are highly reactive. We found, for the first time, that phase transitions from the titanate nanostructures to TiO(2) polymorphs take place readily in simple wet-chemical processes at temperatures close to ambient temperature. In acidic aqueous dispersions, the fibers transform to anatase and rutile nanoparticles, respectively, but via different mechanisms. The titanate fibers prepared at lower hydrothermal temperatures transform to TiO(2) polymorphs at correspondingly lower temperatures because they are thinner, possess a larger surface area and more defects, and possess a less rigid crystal structure, resulting in lower stability. The transformations are reversible: in this case, the obtained TiO(2) nanocrystals reacted with concentrate NaOH solution, yielding hollow titanate nanotubes. Consequently, there are reversible transformation pathways for transitions between the titanates and the titanium dioxide polymorphs, via wet-chemical reactions at moderate temperatures. The significance of these findings arises because such transitions can be engineered to produce numerous delicate nanostructures under moderate conditions. To demonstrate the commercial application potential of these processes, we also report titanate and TiO(2) nanostructures synthesized directly from rutile minerals and industrial-grade rutiles by a new scheme of hydrometallurgical reactions.

Real-time PCR detection of lactic acid bacteria in cecal contents of eimeria tenella-lnfected broilers fed soybean oligosaccharides and soluble soybean polysaccharides

This experiment was conducted to test whether dietary soybean meal oligosaccharides (SMO) and water-soluble polysaccharides (SMP) can assist broiler chickens in resisting Eimeria tenella, and to determine the survival of lactic acid bacteria in cecal contents postinfection. All birds received a soybean meal-free diet. The 6 experimental treatments were as follows: positive (COR) and negative (COW) control groups, 2 groups fed diets containing either 1% SMO or 0.5% SMP from 1 to 11 d of age; a vaccinated group (VAC), and an anticoccidial medicated group (ANT). Chickens of all treatments except COW were orally infected with 1000 sporulated oocysts of E. tenella on d 15. Fecal oocyst shedding was monitored per treatment group between d 5 and 13 postinfection. Lactic acid bacteria (LAB) in cecal contents were evaluated by a real-time PCR technique on d 7 postinfection. The results showed that the SMO and SMP groups had a lower number of oocysts per gram of feces during the monitoring period than the COR group. Threshold cycles were 22.21, 27.68, 13.99, 14.92, 12.97, and 14.85, for COW, COR, SMO, SMP, VAC, and ANT groups, respectively; specific PCR products were confirmed by the results of melting curve analysis and agarose gel electrophoresis. The results suggest that these LAB communities were promoted by SMO and SMP and have a competitive exclusion function when broiler chickens are infected with E. tenella.

Analyzing intramolecular dynamics by fast Lyapunov indicators

We report an analysis of intramolecular dynamics of the highly excited planar carbonyl sulfide below and at the dissociation threshold by the fast Lyapunov indicator method. By mapping out the variety of dynamical regimes in the phase space of this molecule, we obtain the degree of regularity of the system versus its energy. We combine this stability analysis with a periodic orbit search, which yields a family of elliptic periodic orbits in the regular part of phase space and a family of in-phase collinear hyperbolic orbits associated with the chaotic regime.

Suppression of pyrite oxidation by iron 8-hydroxyquinoline

One of the important approaches to prevent pyrite (FeS(2)) oxidation and subsequent formation of acid mine drainage (AMD) is to create a surface coating on pyrite. In this study, a coating of iron 8-hydroxyquinoline was formed by leaching pyrite with a 0.10 M H(2)O(2)/0.0034 M 8-hydroxyquinoline solution; stability of the coated pyrite was tested under various pH and temperature conditions. The results showed that iron 8-hydroxyquinoline coating could significantly suppress further pyrite oxidation by both chemical (H(2)O(2)) and biological ( e.g., Thiobacillus ferrooxidans) processes. At pH from 3.0 to 5.0 and temperature from 10-40 degrees C, the amount of SO(4)(2-) leached out by 0.10 M H(2)O(2) from the coated pyrite samples was 54.8-70.1% less than that from the uncoated controls. The oxidation of pyrite followed a pseudo-zero-order kinetics under the constant concentration of H(2)O(2). In the presence of microorganisms, sulfate leached out of the uncoated pyrite in 1 year accounted for 5.32% of the total pyrite in the system, with a concurrent pH drop to 2.35 under the ambient room temperatures. In contrast, the amount leached out from the coated samples was only 0.15% of the total pyrite and the final pH was 5.48. Thus, the coating decreased the leachability of pyrite by 97% in the inoculated systems. In comparison to the more widely studied iron phosphate coating, the advantage of iron 8-hydroxyquinoline coating was that it inhibited both chemical and biological pyrite oxidation, whereas iron phosphate coating could only inhibit chemical pyrite oxidation.

The mouse snail gene encodes a key regulator of the epithelial-mesenchymal transition

Snail family genes encode DNA binding zinc finger proteins that act as transcriptional repressors. Mouse embryos deficient for the Snail (Sna) gene exhibit defects in the formation of the mesoderm germ layer. In Sna(-/-) mutant embryos, a mesoderm layer forms and mesodermal marker genes are induced but the mutant mesoderm is morphologically abnormal. Lacunae form within the mesoderm layer of the mutant embryos, and cells lining these lacunae retain epithelial characteristics. These cells resemble a columnar epithelium and have apical-basal polarity, with microvilli along the apical surface and intercellular electron-dense adhesive junctions that resemble adherens junctions. E-cadherin expression is retained in the mesoderm of the Sna(-/-) embryos. These defects are strikingly similar to the gastrulation defects observed in snail-deficient Drosophila embryos, suggesting that the mechanism of repression of E-cadherin transcription by Snail family proteins may have been present in the metazoan ancestor of the arthropod and mammalian lineages.

[A study on the resources coping with occupational stress in teachers]

OBJECTIVE

To explore the status of the resources coping with occupational stress in teachers.

METHODS

Occupational stress inventory revised edition (OSI-R) was used to measure their occupational stress, strain and psychological coping resources for 1,460 teachers in primary and secondary schools and 319 non-teacher intellectuals. Analyses were focused on coping resources of teachers.

RESULTS

The higher the level of coping resource of teachers, the lower the personal strain in them, with an inverse correlationship. Coping resource in the teacher group was significantly higher than that in the non-teacher group, with scores of (130.4 +/- 18.2) and (126.9 +/- 19.1), respectively. Coping resource in teachers decreased with the increase of age, with the scores from (134.1 +/- 18.1) in the group aged less than 30 to (128.5 +/- 17.5) in the group aged 50. Coping resource in the female teachers was significantly higher than that in the male teachers, with scores of (131.4 +/- 18.3) and (129.4 +/- 18.1), respectively. Coping resource in the primary school teachers was significantly higher than that in the secondary school teachers, with scores of (132.7 +/- 18.1) and (128.5 +/- 18.1), respectively.

CONCLUSION

It is important to enhance teacher's coping resource, especially for the male teachers in the secondary schools, for improving their teaching efficiency.