bluuebunny/crossref_metadata_2025 huggingface dataset:
Properties of chemically and mechanically isolated fibres of spruce (Picea abies[L.] Karst.). Part 2: Twisting phenomena
Authors: Burgert Ingo , Frühmann Klaus , Keckes Jozef , Fratzl Peter , Stanzl-Tschegg Stefanie
Published: February 2005

The twisting behaviour of chemically and mechanically isolated fibres of spruce (Picea abies[L.] Karst.) was examined. Mechanical isolation was carried out using very fine tweezers to obtain fibres with an unmodified cell wall assembly. Chemical isolation was achieved using hydrogen peroxide and glacial acetic acid, leading to partial degradation of lignin and hemicelluloses. Besides normal adult wood, compression wood and opposite wood fibres were investigated. Fibre twisting while drying increased with higher microfibril angles in the S2 layer, and was significantly less pronounced for mechanically isolated compared to chemically macerated fibres. A simple model is introduced that takes into account the interdependency between lateral cell-wall shrinkage and the microfibril angle in the S2 cell wall.
Radiometric method for the study of the corrosion reactions of steel samples in strongly acidic media
Authors: Cecal Alexandru , Popa Karin , Draghici Camelia L.
Published: February 2005

This study investigates the corrosion of OL–37, OL–60 and 316L type steel samples immersed in acidic media (HCl, HClO4, H2SO4 and HNO3), based on a new radioactive tracer method. This procedure, used for the determination of the global rate constant of metal corrosion reaction, is based on the screening of β
--rays emitted by 204Tl+ radionuclides, present in the aggressive medium of the iron ions which are formed during the process. The global rate constants of corrosion reaction decrease, for a certain metallic sample, in the series HCl > HClO4 > H2SO4 > HNO3, and increase with the concentration of the used acid. For a given aggressive solution, the corrosion process decreased with the decreasing of the carbon amount in each steel sample.
Eu(III), Sm(III), Np(V), Pu(V), and Pu(IV) sorption to calcite
Authors: Zavarin Mavrik , Roberts S. K. , Hakem N. , Sawvel A. M. , Kersting A. B.
Published: February 2005

The sorption behavior of Eu(III), Sm(III), Np(V), Pu(V), and Pu(IV) in the presence of calcite and as a function of pH and carbonate alkalinity was measured by batch sorption experiments. Eu(III) and Sm(III) sorption is similar, consistent with their observed aqueous speciation and precipitation behavior. For both rare earth elements, sorption decreases at the highest and lowest measured pHs. This is likely the result of speciation changes both of the calcite surface and the sorber. An increase in the equilibrium CO2(g) fugacity results in a shift in the sorption behavior to lower pH, consistent with a predicted aqueous speciation shift. Np(V) and Pu(V) sorption exhibited a strong pH dependence. For Np(V), K
ds range from 0 to 217 mL/g suggesting that carbonate aqueous speciation as well as changes in the calcite surface speciation greatly affect Np(V) sorption to the calcite surface. Similar behavior was found for Pu(V). Pu(IV) sorption is also strongly pH dependent. Sorption decreases significantly at high pH as a result of Pu-carbonate complexation in solution. A surface complexation model of Sm(III), Eu(III), Np(V), Pu(V), and Pu(IV) sorption to the calcite surface was developed based on the calcite surface speciation model of Pokrovsky and Schott [1]. Sorption data were fit using one or two surface species for each sorber and could account for the effect of pH and CO2(g) fugacity on sorption. A relatively poor model fit to Pu(IV) sorption data at high pH may result from our poor understanding of Pu(IV)-carbonate aqueous speciation. While our surface complexation model may not represent a unique solution to the sorption data, it illustrates that a surface complexation modeling approach may adequately describe the sorption behavior of a number of radionuclides at the calcite surface over a range of solution conditions.
The Red, Shaking Fool: Dramaturgical Dilemmas in Shyness
Authors: Scott Susie
Published: February 2005

Shyness has previously been conceptualized as an object of psychological study, but a symbolic interactionist approach relocates the condition in its social context. Using data from in‐depth interviews and an e‐mail distribution list, this article considers the ways in which the shy role is defined and negotiated in everyday interaction. It examines the myriad dramaturgical strategies through which shy actors attempt to conceal their lack of poise and competence, as well as how shyness itself can be a discrediting performance. Managing this identity therefore requires complex skills of self‐presentation and paradoxically reveals a strong commitment to the interaction order.
Identification of a Novel Point Mutation of Mouse Proto-Oncogene c-kit Through N-Ethyl-N-nitrosourea MutagenesisSequence data from this article have been deposited with the EMBL/GenBank Data Libraries under accession nos. AY536430 and AY536431.
Authors: Ruan Hai-Bin , Zhang Nian , Gao Xiang
Published: February 2005

Manipulation of the mouse genome has emerged as an important approach for studying gene function and establishing human disease models. In this study, the mouse mutants were generated through N-ethyl-N-nitrosourea (ENU)-induced mutagenesis in C57BL/6J mice. The screening for dominant mutations yielded several mice with fur color abnormalities. One of them causes a phenotype similar to that shown by dominant-white spotting (W) allele mutants. This strain was named Wads because the homozygous mutant mice are white color, anemic, deaf, and sterile. The new mutation was mapped to 42 cM on chromosome five, where proto-oncogene c-kit resides. Sequence analysis of c-kit cDNA from Wadsm/m revealed a unique T-to-C transition mutation that resulted in Phe-to-Ser substitution at amino acid 856 within a highly conserved tyrosine kinase domain. Compared with other c-kit mutants, Wads may present a novel loss-of-function or hypomorphic mutation. In addition to the examination of adult phenotypes in hearing loss, anemia, and mast cell deficiency, we also detected some early developmental defects during germ cell differentiation in the testis and ovary of neonatal Wadsm/m mice. Therefore, the Wads mutant may serve as a new disease model of human piebaldism, anemia, deafness, sterility, and mast cell diseases.
The First Steps of Transposable Elements Invasion
Authors: Le Rouzic Arnaud , Capy Pierre
Published: February 2005

Transposable elements are often considered as selfish DNA sequences able to invade the genome of their host species. Their evolutive dynamics are complex, due to the interaction between their intrinsic amplification capacity, selection at the host level, transposition regulation, and genetic drift. Here, we propose modeling the first steps of TE invasion, i.e., just after a horizontal transfer, when a single copy is present in the genome of one individual. If the element has a constant transposition rate, it will disappear in most cases: the elements with low-transposition rate are frequently lost through genetic drift, while those with high-transposition rate may amplify, leading to the sterility of their host. Elements whose transposition rate is regulated are able to successfully invade the populations, thanks to an initial transposition burst followed by a strong limitation of their activity. Self-regulation or hybrid dysgenesis may thus represent some genome-invasion parasitic strategies.
Agenesis of tibia with bifid femur, congenital heart disease, and cleft lip with cleft palate or tracheoesophageal fistula: Possible variants of Gollop‐Wolfgang complex
Authors: Erickson Robert P.
Published: February 2005

Two patients with bifurcation of one femur, ipsilateral absence of tibia and one partially formed tibia, or bilateral absent tibiae, club feet with normal or nearly normal digits, congenital heart disease and, in one case, tracheoesophageal fistula; in the second, cleft lip and cleft palate and enlarged head with increased fluid and lissencephaly, are described. These appear to be unique combinations of defects but overlap with the Gollop‐Wolfgang complex is present, particularly with the case of possible Gollop‐Wolfgang described by Raas‐Rothschild et al. (1999); Am J Med Genet 84:361–364. © 2005 Wiley‐Liss, Inc.
Radiation‐induced grafting of glycidyl methacrylate onto high‐density polyethylene (HDPE) and radiation lamination of HDPE
Authors: Li Zhirong , Wang Huiliang
Published: February 2005

Radiation‐induced grafting of glycidyl meth‐acrylate (GMA) onto high‐density polyethylene (HDPE) and the radiation lamination of HDPE by bulk grafting of GMA were reported. The effects of irradiation dose, monomer concentration, and atmosphere on grafting were investigated. The extent of grafting initially increased with irradiation dose and then remained almost constant. The extent of grafting was higher in 2M GMA than in 1M GMA at the same irradiation dose. The extent of grafting in nitrogen was higher than that in air. The grafted samples were characterized with FTIR spectrometry and thermogravimetric (TG) analysis. A carbonyl group was found on grafted HDPE samples, and the carbonyl index increased with the extent of grafting. TG analyses proved the existence of grafted materials on HDPE and the grafted GMA thermally decomposes at a temperature lower than that of HDPE. Strong adhesion could be obtained with radiation lamination of HDPE by bulk grafting of GMA. Benzophenone facilitates the grafting in a proper concentration range. The adhesion mechanism of the laminated samples was the entanglement of the grafted chains. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 772–779, 2005
Effect of “glutaraldehyde” functionality on network formation in poly(vinyl alcohol) membranes
Authors: Purss Helen K. , Qiao Greg G. , Solomon David H.
Published: February 2005

The use of higher‐functionality oligomers of glutaraldehyde on network formation was investigated and compared with glutaraldehyde monomer in step‐growth reactions. The effect of using such oligomers in network formation depends on the stoichiometry, which alters either the branching or both the branching and crosslinking of the network. This was demonstrated in the properties of poly(vinyl alcohol) (PVA) networks crosslinked with glutaraldehyde using cryogenic scanning electron microscopy, water swelling studies, and protein transfer across membranes. General guidelines were given for the proper use of glutaraldehyde solutions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 780–792, 2005
Chemosetting resins containing fillers. I. Unsaturated polyester resin compositions containing modified smectites
Authors: Oleksy Mariusz , Heneczkowski Maciej , Galina Henryk
Published: February 2005

Smectic clays with quaternary ammonium salts (QAS) were subjected to hydrophobization, whereupon we applied the products in attempts to modify various polymers. The clays were of natural origin and contained a large proportion of montmorillonite and an original method of modification was applied. A significant improvement of the stability of unsaturated polyester (UP) resins, modified with clays modified with QAS, was observed with essentially no change in the reactivity of resins. The compositions of polyester resins containing 2 wt % of modified smectites had excellent thixotropy. The presence of modified bentonites in a cured commercial UP resin (2–4 wt %) improved its tensile strength (by 21–62%), Brinell hardness (23–70%), and unnotched impact strength (23–100%), depending on the type of bentonite used. The compositions of UP resins with modified clays had certain properties typical for nanocomposites: improved stiffness, strength, transparency, and fine‐lamellar morphology of the fracture as found by electron scanning microscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 793–801, 2005
Synthesis and characterization of water‐soluble conducting polyaniline by enzyme catalysis
Authors: Shen Yuping , Sun Jianzhong , Wu Jiangang , Zhou Qiyun
Published: February 2005

Enzymatic synthesis of a water‐soluble, conducting polyaniline (PANI) was studied, using horseradish peroxidase as the biocatalyst and H2O2 as the initiator, in the presence of a poly(vinylsulfonic acid, sodium salt) (PVS) polyanion template. The effects of the buffer, concentration of H2O2, and the molar ratio of aniline to PVS on the polymerization were particularly investigated. The products were characterized by UV–vis/near‐IR and FTIR spectroscopy, thermogravimetric analysis, and four‐point probe conductivity measurement. The results showed that PVS could be chosen as a new template in the synthesis of PANI. The proper conditions of polymerization were obtained as follows: pH of the buffer was pH 4.0–5.0, the concentration of H2O2 was around 20 mM, and the molar ratio of PVS to aniline was 1–1.5. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 814–817, 2005
Characterization of mannosyl transferases during the pupal instar of Stomoxys calcitrans (L)
Authors: Mayer RicharD. T. , Chen A. C. , Deloach J. R.
Published: February 2005

Particulate fractions (10,000g) from pupae of Stomoxys calcitrans transfer [14C]‐mannose from GDP‐[14C]‐mannose to dolichol monophosphate and proteins. Production of the mannosyl lipid was inhibited by Mn2+, UDP, GMP, GDP, and EDTA. The insect growth regulator diflubenzuron had no effect on mannosyl transferase activity. Dolichol monophosphate and Mg2+ stimulated mannosyl transferase activity. The mannosyl lipid product was identified as mannosyl‐phosphoryl‐dolichol (Man‐P‐Dol). The apparent Km and Vmax values for the formation of Man‐P‐Dol using GDP‐[14C]‐Man while holding dolichol phosphate constant were 2.4 ± 0.9 μM and 9.4 ± 2.3 pmol Man‐P‐Dol·min−1·mg−1 protein, respectively. The apparent Km and Vmax values using dólichol phosphate while holding GDP‐Man constant were 2.2 ± 1.2 μM and 18.5 ± 1.7 pmol Man‐P‐Dol·min−1·mg−1 protein.
Juvadecene: Discovery of a juvenile hormone mimic in the plant, Macropiper excelsum
Authors: Nishida R. , Bowers W. S. , Evans P. H.
Published: February 2005

A compound with significant insect juvenile hormone activity was isolated from the plant, Macropiper excelsum. The chemical structure was determined by spectral methods to be 1‐(3,4‐methylenedioxyphenyl)‐trans‐3‐decene(l), and confirmed by synthesis. The hormonally active substance applied topically to last (fifth)‐instar nymphs of the milkweed bug (Oncopeltus fasciatus) induced a supernumerary metamorphosis at 30 μg. Higher doses were toxic.
Induction of cytochrome P‐450‐dependent drug metabolism by juvenile hormone mimics in mammalian cell culture
Authors: Agosin Moises , Repetto Yolanda
Published: February 2005

The monooxygenase activity of fetal hepatocytes in culture shows a differential response toward juvenile hormone I and analogs. Juvenile hormone I, R‐20458, and Methoprene increase the deethyiation of 7‐ethoxyresorufin while not affecting or even inhibiting the N‐demethylation of p‐chloro‐N‐methylaniline. RO‐203600, a 1,3‐benzodioxole‐containing analog, increases both the deethylase and the N‐demethylase, whereas Hydroprene does not affect either activity. The inductive effect with juvenile hormone I is obtained with exposure periods of at least 30 min and is maximum when the concentration of the hormone is 14 μM in the medium. This amount results in the covalent binding to cellular macromolecules of 1.3 × 19−18 moles/cell. The induction requires continuous protein synthesis but RNA synthesis only for a short initial period. It is concluded that juvenile hormone and mimics induce specific cytochrome P‐450 species in fetal liver cells even if the culture conditions are not optimal. The toxicological implications of these results are briefly discussed.
On the relationship between the electroantennogram and simultaneously recorded single sensillum response of the european corn borer, Ostrinia nubilalis
Authors: Nagai Toshio
Published: February 2005

Electrical responses of the whole antenna (electroantennogram) and that of the single sensillum trichodeum (electrosensillogram) of male moth of the European corn borer, Ostrinia nubilalis, to their two pheromone components, (Z)‐ and (E)‐11‐tetradecenyl acetates, were recorded simultaneously. The configuration characteristics of both responses resemble each other, and demonstrate an interaction between sensilla trichodea. The typical difference in the response pattern between London (Ontario) and New York strains of this moth seems to be a property of the sensillum trichodeum.
Spontaneous and neurally evoked contractions of visceral muscles in the oviduct of Locusta migratoria
Authors: Lange Angela B. , Orchard Ian , Loughton Barry G.
Published: February 2005

The oviducts of Locusta migratoria are innervated by a pair of nerves which arise from, the seventh abdominal ganglion. A distinctive network of striated muscle fibres occurs in the oviducts. The lateral oviducts and common oviduct consist of an inner circular layer of muscle and an outer longitudinal layer of muscle. At the junction of the lateral and common oviduct an additional thin longitudinal layer is found adjacent to the basement epithelium.

The oviducts contracted spontaneously when isolated from the central nervous system. These myogenic contractions took the form of peristaltic contractions in the lateral oviduct, and intermittent phasic‐like contractions of the posterior regions of the lateral oviduct and the common oviduct. These phasic‐like contractions were associated with individual complex potentials recorded extracellularly from the muscle fibres.

In locusts that had been interrupted in the process of egg laying, there were large‐amplitude action potentials, firing in a bursting pattern, in the oviducal nerves. These large action potentials were absent in locusts that had not been egg‐laying. These action potentials were associated with both bioelectric potentials and mechanical events in the posterior region of the lateral oviduct and the common oviduct.

Electrical stimulation of the oviducal nerve mimicked the effects of spontaneous action potentials, resulting in the appearance of monophasic potentials and contractions. The contractions were graded and dependent upon both frequency and duration of stimulation.

It is concluded that the oviducts of Locusta are both myogenic and neurogenic. The role of these contractions in oviposition is discussed.
Evidence for chitin synthesis in an insect cell line
Authors: Marks Edwin P. , Balke Jeffrey , Klosterman Harold
Published: February 2005

Cells from the continuous MRRL‐CH line derived from embryos of the tobacco hornworm synthesized chitin. Digestion of the washed pellet from [14C]‐N‐acetylglucosamine‐labeled cells by chitinase yielded a water‐soluble labeled compound. The lyophilized residue from the supernatant of the chitin digestion was analyzed by gas‐liquid chromatography as its trimethylsilyl derivative. The major component cochromatographed with derivitized chitobiose. The presence of chitobiose was confirmed by gas chro‐matography‐mass spectrometry. The synthesis of chitin by this cell line is inhibited by diflubenzuron.
Ten generations of Drosophila melanogaster reared axenically on a fatty acid‐free holidic diet
Authors: Rapport E. W. , Stanley‐Samuelson D. , Dadd R. H.
Published: February 2005

Wild‐type Drosophila melanogaster were axenically raised on a completely synthetic fatty acid‐free diet for at least ten consecutive generations, confirming that these insects do not require dietary polyunsaturated fatty acids. Capillary column gas‐chromatographic analysis of lipids extracted from adults reared on yeast medium showed a peak which cochromatographed with linoleic acid, representing about 1.2% and 0.15% of all fatty acids in phospholipids and triacylglycerols, respectively. In flies reared on the synthetic diet for one generation or for five or more generations, the linoleic acid peak was still present but in about tenfold lower proportions of total fatty acids. This was true of both phospholipid and triglyceride fractions.
Effects of 20‐hydroxyecdysone and tunicamycin on glycoprotein synthesis in an insect cell line
Authors: Jang Eric B. , Klosterman Harold J. , Marks Edwin P.
Published: February 2005

Treatment of CH‐MRRL cells with either 20‐hydroxyecdysone or tunicamycin resulted in a decrease in the incorporation of labeled sugars into glycoproteins. This change appears to be largely quantitative, as few qualitative changes in protein bands were apparent as determined by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. Tunicamycin caused a greater change in the amount of labeled sugar incorporated into specific glycoproteins than did 20‐hydroxyecdysone. This was more apparent in [14C]‐mannose‐labeled than in [14C]‐N‐acetylglucosamine‐labeled glycoproteins. Both compounds caused changes in cell surface glycoproteins. These changes are discussed in relation to previous work on binding of lectins to the cell surface and on the mode of action of tunicamycin.
Effects of the venom of Philanthus triangulum F. (Hym. sphecidae) and β‐ and δ‐philanthotoxin on axonal excitability and synaptic transmission in the cockroach CNS
Authors: Piek Tom , Hue Bernard , Pelhate Marcel , David Jonathan A. , Spanjer Willem , Veldsema‐Currie Robin D.
Published: February 2005

This paper provides answers to the questions which of the toxins present in the venom of the wasp Philanthus triangulum may be responsible for the previously reported blockage of transmission through the sixth abdominal ganglion of the cockroach, and whether this may occur by block of synaptic transmission or by affecting axonal exitability. In current clamp experiments the crude venom induces a slight depolarization of the membrane of the giant axon from the sixth abdominal ganglion of the cockroach and a small and irreversible decrease in the amplitude of the action potential. These marginal effects are not seen with relatively high concentrations of the philanthotoxins β‐PTX and δ‐PTX. It appears that neither the crude venom nor the toxins significantly affect the excitability of the cockroach giant axon. At a concentration of 20 μg ml−1 δ‐PTX causes a slowly reversible block of synaptic transmission from the cercal nerve XI to a giant interneuron without any change in resting membrane potential, whereas β‐PTX is inactive. Iontophoretically evoked acetylcholine potentials of the giant neuron are more sensitive to δ‐PTX than excitatory postsynaptic potentials. This suggests that the toxin acts on the postsynaptic membrane.
Metabolism of [3H]‐ecdysone in Schistocerca gregaria; formation of ecdysteroid acids together with free and phosphorylated ecdysteroid acetates
Authors: Gibson J. M. , Isaac R. E. , Dinan L. N. , Rees H. H.
Published: February 2005

The metabolism of [3H]‐ecdysone has been investigated at times of low and high endogenous ecdysteroid tit re, in early and late fifth‐instar Schistocerca gregaria larvae, respectively. Ecdysone‐3‐acetate, 20‐hydroxyecdysone, and 20,26‐dihydroxyecdysone were identified as metabolites in both the free form and as polar conjugates. Comparison of the intact polar conjugates of the ecdysteroid acetates on two HPLC systems with the corresponding authentic compounds indicated that they were 3‐acetylecdysone‐2‐phosphate and 3‐acetyl‐20‐hydroxyecdysone‐2‐phosphate. Other major polar metabolites were identified as ecdysonoic acid and 20‐hydroxyecdysonoic acid. Ecdysone metabolism in fifth‐instar S. gregaria is apparently an age‐dependent process. Early in the instar, excretion of both free and conjugated ecdysteroids, as well as ecdysteroid 26‐acids, occurs. At this stage the level of ecdysteroid acetates in the conjugated (phosphate) form is high, in contrast to the free ecdysteroids, where ecdysone predominates. When the endogenous hormone titre is high, the formation of ecdysteroid acetates is less, the major excreted matabolites at that stage being conjugated 20‐hydroxyecdysone together with ecdysteroid‐26‐acids, but little free ecdysteroids. Acetylation of ecdysone occurs primarily in the gastric caecae. Ecdysone‐3‐acetate (mainly as polar conjugate) is also a major product of ingested ecdysone in early fifth‐instar Locusta migratoria.
Biosynthesis of Drosophila yolk polypeptides
Authors: Minoo Parviz , Postlethwait John
Published: February 2005

The three yolk polypeptides (YPs) of Drosophila are synthesized and secreted by female fat body and ovarian follicle cells, sequestered by pinocytosis into oocytes, and finally deposited into yolk granules. The biosynthesis of the YPs was studied using two‐dimensional gels. Labeling the YPs with [35S]‐cysteine, an amino acid found only near the amino terminus of YP1 and YP2, showed that an amino terminal peptide is removed from YP1 and YP2 shortly after or during translation.

Intermediates in YP biosynthesis corresponding in electrophoretic mobility to pancreatic membrane‐processed primary translation products were also detected in a 5‐min pulse label with [35S]‐methionine. Genetic variants that alter YP structure were used to identify which YP precursor comes from which Yp gene. Pulse labeling with [35S]‐methionine revealed that all three YPs becomes more negatively charged, that YP1 and YP2 become heterogeneously charged, and that YP1 gains in apparent molecular weight within 15 min after translation.

Injecting female flies with radioiabeled sugars or orthophosphate revealed that the YPs are glycosylated and phosphorylated. Treating hemolymph proteins with phosphatase showed that phosphorylation is responsible for much of the change in charge and increase in molecular weight of the maturing YPs. These experiments with wild‐type flies provide a basis for the analysis of mutations at the Yp genes which alter the structure of individual YPs.
Host‐plant resistance of sorghum: Differential hydrolysis of sorghum pectic substances by polysaccharases of greenbug biotypes (Schizaphis graminum, homoptera: Aphididae)
Authors: Campbell Bruce C. , Dreyer David L.
Published: February 2005

Pectic substances extracted from different varieties of sorghum are hydrolyzed at differing rates by unfractionated polysaccharases isolated from two biotypes (C, GBC; and E, GBE) of the sorghum pest, Schizaphis graminum (the greenbug). A higher degree of susceptibility of a sorghum variety is associated with a greater rate of hydrolysis of sorghum pectic substances by a greenbug biotype. Increases in the specific activity of polysaccharases on the pectic substances from a resistant sorghum variety are dependent on the duration that a biotype is maintained as a colony on that variety. Polysaccharase activity of GBE on arabinogalactan was significantly greater than GBC. However, there were no differences between the biotypes on the depolymerization of a variety of other plant matrix polysaccharides and a synthetic polysaccharide. The sequence of substrates of increasing refractoriness to hydrolysis are: arabinogalactan < microcrystalline cellulose < xylan < pectin < 2,3‐diacetyl pectin < α‐1,4‐galacturonan. Pectic substances from sorghum varieties resistant to GBC but susceptible to GBE are relatively lower in arabinogalactan with elevated levels of uronic acid (UA) compared to varieties susceptible to both biotypes. A sorghum variety resistant to both GBC and GBE was lowest in levels of arabinogalactan, highest in UA, and highest in fructan content, which in the other varieties occurred only in trace amounts. Pectic composition of rhamnose, xylose, and glucose showed no relationship to resistance. Bound phenolics (potential inhibitors of enzyme activity) were not detected in any of the sorghum pectic substances. The relationship of plant matrix polysaccharides to host‐plant aphid biotype compatibility is discussed.
Sublethal effects of permethrin on the chemical communication system of the pink bollworm moth, Pectinophora gossypiella
Authors: Haynes K. F. , Baker T. C.
Published: February 2005

Topically applied sublethal doses of permethrin can interrupt chemical communication between the sexes of Pectinophora gossypiella by affecting both the signaler and the responder. The probability of calling by females is reduced when they are treated with doses of permethrin which are much less than the LD50. Similarly, key stages in the behavioral response of males to sex pheromone are effectively blocked at these low doses. Males recover from these effects 4 days after treatment, but calling by females is still significantly reduced at this time. Chemical control of P. gossypiella populations with permethrin may not be limited to mortality, and potentially includes effective control of behavioral aspects of chemical communication.
Ecdysteroid receptors in a tumorous blood cell line of Drosophila melanogaster
Authors: Dinan Laurence
Published: February 2005

The tumorous Drosophila melanogaster blood cell line BII has been studied for evidence for the presence of ecdysteroid receptors. The [3H]ponasterone A (pon A)* used in this study has been extensively purified, and the location of the tritium in the molecule has been partially determined. BII cells do not metabolise ecdysteroids. Intact cells demonstrate a considerable specific uptake of [3H]pon A which is saturable, apparently showing two specific components: a very high affinity component (KD = 0.3 nM) and a high affinity component (KD = 2 nM). The specific binding of [3H]pon A to whole cells is compatible with unlabelled ecdysteroids, but not with mammalian steroid hormones. The association rate constant (ka) for [3H]pon A was determined to be 3 × 107M−1min−1 at 21 °C, while the dissociation rate constant (kd) for the specifically bound [3H]pon A was found to be 4.4 × 10−3/min. Together, the kinetic rate constants yield a value of 0.15 nM for the KD.

The receptors have been partially characterised in a cell‐free extract prepared by sonification of the cells. The optimum pH for extraction and hormone binding is 8.2. Scatchard plots of binding data indicate that the cell‐free extract also contains two high affinity specific binding components (kD = 0.1 nM and KD = 1 nM). The hgih affinity binders are macromolecular, as shown by chromatography on Sephadex G‐25, and are susceptible to protease digestion, heat, and treatment with N‐ethylmaleimide. Sucrose density centrifugation of the labelled receptor shows one peak at approximately 6S. The stability of the receptor preparation has been studied and conditions have been empirically determined (10% w/v sucrose, 25 mM dithioerthreitol, and 10 mM citrate), whereby the binding capacity of the unlabelled receptor is stable for at least 8 weeks if frozen at −20°C.
Physiological investigation on the role of the innervation in the regulation of the prothoracic gland in Periplaneta americana
Authors: Richter Klaus
Published: February 2005

Under in vitro conditions the prothoracic gland nerve of the last larval instar of Periplaneta americana shows the same efferent nervous activity as under in situ conditions–ie, low activity at the 9th day and high activity at the 20th day of the molting interval. Isolation of the prothoracic ganglion from the subesophageal ganglion provokes an increase in this nerve activity, suggesting an inhibitory effect of the subesophageal ganglion on prothoracic gland nerve activity in vivo. Only in 20‐day‐old larvae does electrical stimulation of isolated prothoracic glands in vitro via the gland nerve result in a slightly increased release of ecdysteroids from the gland. This effect could not be influenced by different lengths of stimulation periods. Denervation of the prothoracic gland by transection of the gland nerve on the 13th day of the molting interval results in a complete abolition of the first peak of ecdysteroid production in the gland but has no influence on the occurrence and the amount of the main ecdysteroid peak just before the molt. The results suggest the participation of nervous activity in special periods of prothoracic gland regulation in the cockroach.
Isolation and characterization of highly purified mosquito oostatic hormone
Authors: Borovsky Dov
Published: February 2005

Oostatic hormone, the hormone that inhibits vitellogenesis in mosquitoes, was purified 7,000‐fold with a recovery of 70% from the ovaries of the mosquito Aedes aegypti. The purification procedure included heat treatment and chromatography on ion exchange and gel filtration columns. The hormone is a small peptidelike molecule of molecular weight 2,200 at pH 4.5, which aggregates into larger molecular species of trimer and octamer at pH 7.0 as determined by gel filtration. The hormone is positively charged at pH 7.8 and has a low Rf at pH 9.4 on disc gel electrophoresis.

Injection of purified oostatic hormone (9 ng) into female mosquitoes inhibited yolk deposition and vitellogenin synthesis. Activity of the oostatic hormone in the mosquito ovary increased rapidly following blood feeding and reached a maximum after 48 h. Oostatic hormone of A. aegypti injected into autogenous Aedes taeniorhynchus inhibited egg development. Repeated injections of dilute oostatic hormone at 24 h intervals partially arrested egg development, resulting in 60% reduction in the number of eggs laid. This hormone does not block release of egg development neurosecretory hormone (EDNH) from the mosquito brain but rather appears to act on the ovary.
Characterization of juvenile hormone‐binding proteins of hemolymph of Locusta migratoria
Authors: Roberts P. Elaine
Published: February 2005

The binding of juvenile hormone (JH) by components from hemolymph of adult female Locusta migratoria was characterized to establish whether hemolymph JH‐binding proteins could be distinguished from a protein of fat body (BP‐1) that may be a JH receptor. Hemolymph was analyzed by the hydroxyapatite assay, gel separation chromatography, polyacrylamide gel electrophoresis, and density gradient centrifugation. Three fractions that bound JH were separated from whole hemolymph by DEAE cellulose column chromatography, and these differed from all three cytosol‐binding components. The major hemolymph component (H‐A) showed relatively stable binding of JH, a slight loss of binding capacity after delipidation, and a Kd for JH‐I of 16 nM. The Kds for JH‐l and JH‐lll with unfractionated hemolymph were 26 and 42 nM respectively. The order of effectiveness of competitors for binding of [3H]JH‐l was JH‐lll > JH‐l ≫ methoprene > hydroprene ≫ acids of methoprene and hydroprene. The data indicated that unlabeled JH‐lll was bound more effectively than its radioactive counterpart. The sedimentation values determined by sucrose density gradient ultracentrifugation were 13‐14 S for hemolymph, and the sedimentation value was not altered by the inclusion of 0.4 M KCl throughout the gradient. The data indicated that H‐A resembled the specific JH carriers and differed from the putative receptor of fat body cytosol by several criteria.
Critical roles for juvenile hormone and its esterase+ in the prepupa of Trichoplusia ni
Authors: Jones Grace , Hammock Bruce D.
Published: February 2005

In the caterpillar Trichoplusia ni (Lepidoptera: Noctuidae) it has been demonstrated by allatectomy that the appearance of juvenile hormone during the prepupal stage is crucial for the successful larval‐pupal ecdysis of most larvae. Application of juvenile hormone or juvenile hormone esterase inhibitors at key times disrupted normal development as well. Thus the subsequent disappearance of juvenile hormone is regulated by degradation by juvenile hormone esterase in addition to a hypothetical reduction in biosynthesis. This reduction in juvenile hormone titer in the prepupa is just as critical for normal development as was its previous appearance. These observations on the critical role of juvenile hormone in the prepupa are in contrast to observations in some other species. For instance, in the case of Manduca sexta (Lepidoptera: Sphingidae), juvenile hormone is considered only supplementary to the action of prothoracicotropic hormone in the postwandering stage and primarily is required for normal pupal development. It thus appears that even within the Lepidoptera the role of juvenile hormone in prepupal development can vary dramatically.
The role of the male accessory gland fluid in stimulating vitellogenesis in Aedes taeniorhynchus
Authors: Borovsky Dov
Published: February 2005

Injection of 20‐hydroxyecdysone (20‐OH‐ecdysone) at high concentrations (5.0 μg) into intact or decapitated female Aedes taeniorhynchus induced vitellogenin synthesis, whereas low concentrations (5.0 ng) were ineffective. Injections of male accessory gland fluid (MAGF), however, at a concentration that was equivalent to 0.25 of the content of a pair of accessory glands, into intact or decapitated A. taeniorhynchus induced viteliogenin synthesis only in intact females. Ovariectomized mosquitoes did not synthesize vitellogenin after MAGF injection or blood feeding. Females that were first injected with MAGF and decapitated 12 h later synthesized viteliogenin at a rate that was 80% of intact controls.

Egg development neurosecretory hormone (EDNH) activity in the heads of ovariectomized or intact females injected with MAGF was 9.0 pmol/min/head and 2.5 pmol/min/head, respectively, indicating that MAGF does not stimulate the corpus cardiacum (CC) to release EDNH.

Incubation of MAGF and EDNH with fat bodies failed to induce vitellogenin synthesis. These results indicate that in A. taeniorhynchus the MAGF induces the ovary to release corpus cardiacum stimulating factor, which then signals CC to release stored EDNH.
Properties of the Δ11‐desaturase enzyme used in cabbage looper moth sex pheromone biosynthesis
Authors: Wolf Walter A. , Roelofs Wendell L.
Published: February 2005

The biosynthesis of a large number of sex pheromone components of various moth species can be explained by invoking a Δ 11‐desaturation of common fatty acids. A Δ11‐desaturase system from Trichoplusia ni, the cabbage looper moth, is identified and partially purified. Some of its properties are defined and compared with those of the ubiquitous Δ‐9 desaturase enzyme. Similarities between the two systems include subcellular location (microsomal), substrate specificity (16‐ and 18‐carbon acids), and lack of sensitivity to carbon monoxide, while differences include cofactor preference (NADH rather than NADPH), sensitivity to cyanide ion, pH optimum (7.4‐7.8 vs 6.8‐7.2), and location in the organism (in the pheromone gland compared to generally distributed). The effects of insect age were also investigated.
Comparison of some properties of the high‐affinity juvenile hormone binding protein from the larval hemolymph of pyralid moths
Authors: Lenz C. J. , Dillwith J. W. , Chippendale G. M.
Published: February 2005

The properties of the high‐affinity low molecular weight juvenile hormone (JH) binding protein present in the hemolymph of larvae of five species of pyralid moths, a noctuid moth, and a sphingid moth were compared. The pyralid moths exhibit a facultative diapause as last‐instar larvae. The species employed were the southwestern corn borer, Diatraea grandiosella, the southern cornstalk borer, Diatraea crambidoides, the sugarcane borer, Diatraea saccharalis, the European corn borer, Ostrinia nubilalis, the sunflower moth, Homoeosoma electellum, the cabbage looper, Trichoplusia ni, and the tobacco hornworm, Manduca sexta. The binding characteristics of the proteins were determined using saturation binding assays and competitive binding assays. The dissociation constants of JH I, JH II, and JH III for the binding protein of all the species varied from 0.8 x 10−7 M to 2.8 x 10−7 M. Calibrated gel filtration showed that the binding protein of all the species had apparent molecular weights ranging from 29,000 to 31,000. Electrophoresis in 7% acrylamide gels revealed that the relative mobilities of the binding proteins ranged from 0.33 to 0.43. Isoelectric focusing showed that the binding proteins had isoelectric points between 4.4 and 5.0.
In vitro ecdysteroid conjugation by enzymes of Manduca sexta midgut cytosol
Authors: Weirich Gunter F. , Thompson Malcolm J. , Svoboda James A.
Published: February 2005

In incubations with 80,000g supernatant of Manduca sexta midgut homogenates, [3H]ecdysone was converted to 3‐[3H]epiecdysone and tritiumlabeled highly polar metabolites. C18 SEP‐PAK cartridges were found suitable for the separation and purification of the free ecdysteroids and of the highly polar metabolites. Eighty to ninety percent of the metabolites were hydrolyzed by enzyme mixtures (mainly β‐glucuronidase, sulphatase, and acid phosphatase) from molluscs, even when β‐glucuronidase activity was completely inhibited by D‐saccharic acid 1,4‐lactone, or various human acid phosphatases (free of sulphatase activity). In each experiment, the hydrolysate contained a much higher proportion of 3‐epiecydsone than the free (unconjugated) ecdysteroid fraction. [3H]ecdysone was not metabolized in anaerobic incubations of midgut supernatant that had been filtered through Sephadex G‐25. Addition of 5 mM ATP and 5 mM Mg2+ restored the conjugate formation in incubations of Sephadex‐filtered supernatant. Four ecdysone conjugates and two 3‐epiecdysone conjugates were resolved by reversedphase ion‐pair high‐performance liquid chromatography. It is concluded that the midgut cytosol contains several ATP:ecdysteriod phosphotransferases. This is the first demonstration of the formation of ecdysteroid phosphoconjugates in a cell‐free system.
Modulatory effects of octopamine and serotonin on male sensitivity and periodicity of response to sex pheromone in the cabbage looper moth, Trichoplusia ni
Authors: Linn C. E. , Roelofs W. L.
Published: February 2005

The pheromone‐mediated flight behavior of male cabbage looper moths in a sustained‐flight tunnel and random activity exhibited during scotophase were observed after males were treated with octopamine or serotonin (5 hydroxytryptamine). Octopamine induced a hypersensitivity to the olfactory signal, resulting in a significant lowering of the pheromone dose that elicited peak levels of response. Octopamine, however, did not affect the circadian rhythmicity of response to pheromone. In contrast, serotonin disrupted the circadian rhythmicity of response, resulting in a high percentage of males exhibiting random activity and response to pheromone throughout the entire 8 h scotophase instead of during the normal peak period during the latter part of the scotophase. Serotonin did not effect a decrease in the dose of pheromone eliciting peak response. In addition, at the highest dosages tested octopamine and serotonin induced opposite postures associated with a paralysis that occurred when males attempted to take flight to the pheromone.
Possible inactivation of ingested ecdysteroids by conjugation with long‐chain fatty acids in the female tick Ornithodoros moubata (acarina:argasidae)
Authors: Connat J.‐L. , Diehl P. A. , Thompson M. J.
Published: February 2005

Ornithodoros moubata females proved to be extremely sensitive to ingested 22,25‐dideoxyecdysone; 15‐20 ng provoked molting in all females and temporarily inhibited vitellogenesis. In contrast, this tick was very resistant to ingested ecdysteroids containing 22‐OH groups, such as ecdysone, 20‐hydroxyecdysone, ponasterone A, and makisterone A. Dosages about 500 times greater were necessary to produce supermolting and reduce fecundity [Connat et al: Z Ang Ent 96, 520 (1983)]. Ingested tritiated ecdysone, 20‐hydroxyecdysone, 2‐deoxyecdysone, and ponasterone A were rapidly converted to apolar esterase‐labile metabolites having approximately the same retention time as the AP2 identified as esters of ecdysteroids at C‐22 with long‐chain fatty acids (C16:0, C18:0, C18:1, C18:2) [Diehl et al: Int J Invert Reprod Dev 8, 1 (1985)]. These products were then gradually transformed to the more polar apolar conjugates, AP1. A more detailed study with ingestion of large quantities of 20‐hydroxyecdysone (10 μ/ml blood) demonstrated that only small amounts of free hormone were present in the hemolymph during the first day after the blood meal. The hormone was rapidly metabolized to AP2, then to AP1, in the intestinal cells and to a lesser extent in the peripheral tissues. Finally, AP1 accumulated in the intestinal cells and midgut content, probably because excretion outside the animal is impossible in this tick species.

In contrast, ingested 22,25‐dideoxyecdysone was not metabolized to apolar products. This could account for its high biological activity. This compound was converted to unidentified more polar products. Two of them comigrated with ecdysone and 20‐hydroxyecdysone on RP‐18 HPLC column, but not on silica column, and therefore cannot correspond to these compounds.

We hypothesize that esterification of ecdysteroids at the C‐22 position with fatty acids represents a detoxification mechanism for ingested ecdysteroids that might be present in blood from herbivorous or parasite‐infected hosts.
Change in corpus allatum function during metamorphosis of the tobacco hornworm Manduca sexta: Regulation at the terminal step in juvenile hormone biosynthesis
Authors: Bhaskaran Govindan , Sparagana Steven P. , Barrera Punnee , Dahm Karl H.
Published: February 2005

Changes in activity of the corpora allata (CA) during larval‐pupal‐adult development of the tobacco hornworm Manduca sexta were studied by transplantation assays, measurements of in vitro juvenile hormone (JH) and JH acid synthesis, and determination of JH acid methyltransferase (JHAMT) and 3‐hydroxy‐3‐methylglutaryl coenzyme A (HMG‐CoA) reductase activities. The data from these assays demonstrate that the CA cease to secrete JH by day 4 of the last larval instar (wandering stage). With regard to JH synthesis, they remain inactive throughout the prepupal, pupal, and most of the pharate adult periods. CA of females, but not of males, resume JH synthesis shortly before eclosion. The biochemical basis of the inactivation process is the loss of JHAMT activity. However, prepupal CA produce JH acids, as shown by enzyme and in vitro assays. Pupal and pharate adult CA do not synthesize JH acids although levels of HMG‐CoA reductase activity seem to remain relatively high. Radiolabeled JH was recovered from hemolymph of allatectomized prepupae that had been injected with radiolabeled JH acid. These results provide further evidence that certain peripheral tissues (eg, imaginal discs) convert JH acid secreted by the prepupal CA to JH and, thus, that JH acid is a prohormone in the prepupal period. The CA change from hormone secretion to prohormone secretion during larval‐prepupal transformation, a unique functional alteration in an endocrine gland.
Mitochondrial biogenesis during spermatogenesis in Heliothis virescens, H. subflexa, and their male‐sterile backcross hybrids
Authors: Miller Stephen G. , Huettel Milton D.
Published: February 2005

The mitochondrial proteins synthesized by spermatogenic cells from Heliothis virescens, H. subflexa, and their male‐sterile backcross progeny were analyzed by using two‐dimensional gel electrophoresis. This subset of total cellular proteins was defined by using a combination of cellular fractionation techniques and pulse‐labeling in the presence of antibiotics. Mitochondrial morphology was also evaluated in cells from fertile and sterile testes by using the laser dye rhodamine 123. These studies revealed that while abnormal mitochondrial structures are apparent in sperm from backcross moths, neither protein synthesis nor import into the organelle was affected in these individuals. Two mitochondrial proteins exhibiting charge variation between the two parental hybridizing species have been identified, and these results are discussed within the context of a hypothesis developed to account for the sterility phenomenon.