bluuebunny/crossref_metadata_2025 huggingface dataset:
DETERMINATION OF MOISTURE CONTENT WITH A GAMMA BACKSCATTER DENSITY GAUGE
Authors: CIFTCIOGLU O. , BYATT D. A. , TAYLOR D.
Published: August 2006

Gamma‐radiation, backscatter gauges, as normally employed for the determina‐tion of the bulk density of soils, use integral mode counting. They are relatively insensitive to the presence of soil moisture and hence not generally suitable for monitoring soil moisture content, particularly, if the soil type effect is minimized by counting only gamma‐photons of energy > 0.400 MeV for a 137Cs source. However, using differential mode counting with the window set at about 0.08 MeV, the phenomenon is one of multiple instead of single scattering. With a source‐detector Separation of the order of 20 cm, about eight Compton in‐teractions are obtained and, as a multiplying factor of ZjA is involved at each interaction, the increased response with hydrogen‐containing material is easily observable. The value of Z/A for hydrogen is 1.0, and for materials not containing hydrogen about 0.5; therefore for water it is 5/9. Hence under these conditions, the response for water compared with non‐hydrogen‐containing materials is [(s/9)/(1/2)]8= 2.32 times, an increase of 132 per cent. This method can therefore be exploited to measure the moisture content of soils. The sensitivity is high, and the accuracy is better than ± 5 per cent, which is not as good as can be achieved with a separate thermal neutron detector, but is useful for many purposes and, of course, only one instrument is required.
Studies on the rate of decomposition of plant residues in soil by following the changes in sugar components
Authors: CHESHIRE M. V. , INKSON R. H. E. , MUNDIE C. M. , SPARLING G. P.
Published: August 2006

Uniformly 14C labelled straw and ryegrass leaf were incubated in soil in the proportions 0.5 and 1% w/w, respectively at 12°C for various periods up to 5 years.

Samples were hydrolysed with 2.5 m H2SO4 under reflux for 20 min to release non‐cellulosic sugars and subsequently with 12 M/0.5 m H2SO4 to release glucose from cellulose‐like polymers. Total radioactivity was determined in whole soil and hydrolysates and in individual sugars.

Fitting the data to simple exponential equations, total and 2.5 m H2SO4 hydrolysate radioactivity were best expressed by three part exponential functions, whereas radioactivity in 12M/0.5M H2SO4 hydrolysates and sugars were best expressed by two part functions, except for arabinose from the straw, for which a three‐part function was better.

A comparison of the fit was made with that using the single‐term exponential expressions devised by Janssen, 1984 and Weibull, 1951 and with a modification of the two part exponential expression by the substitution of one term by the Weibull expression. Apart from the Weibull expression on its own, there was no significant difference between the expressions.

It is suggested that, even for well defined carbohydrate components of the substrate, the decomposability changes with time because of their increasing inaccessibility to microorganisms, rather than that several components are present each with a different constant rate of decomposition.
One‐dimensional biophysical modelling of fish egg vertical distributions in shelf seas
Authors: PETITGAS PIERRE , MAGRI STÉPHANIE , LAZURE PASCAL
Published: August 2006

Modelling the vertical distribution of fish eggs is important when assessing fish stocks with egg production methods and for monitoring the reproductive potential of fish populations. Fish eggs are passive particles and their vertical distribution is determined by a few parameters such as egg density, egg diameter, wind‐ and tide‐induced turbulence, and vertical hydrographic structure. A one‐dimensional vertical biophysical, numerical model was developed which was adapted to the hydrography of shelf seas under the influence of tidal currents, wind‐induced circulation, and river discharges. The biological part of the model parameterized the ascent velocity of the egg as a function of egg properties (diameter, density) and water properties (density, viscosity, turbulence). The model contains a turbulence closure which makes the model dynamic. The model parameters were surface wind, tidal currents, T‐S profile, and egg diameter and density, which were kept constant in time. The model has the capacity to generate sub‐surface egg maxima in different hydrographic conditions, e.g. in areas under the influence of river plumes, and can also homogenize the egg distribution under wind and tide forcing. Sensitivity tests were carried out to study the response of the model to variations in the model parameters for a variety of hydrographic conditions. The modelled egg vertical distributions were validated by comparison of the model results with egg distributions sampled in the field. The analysis highlighted variability in fish egg density of anchovy, sardine, and sprat across years and areas, with a potential link between egg density and surface sea water density. The validated model is a tool for the analysis of shelf seas fish egg vertical distributions.
Robust salivary gland‐specific transgene expression in Anopheles stephensi mosquito
Authors: Yoshida S. , Watanabe H.
Published: August 2006

Malaria sporozoites invade the mosquito salivary glands and wait in the salivary duct until the next blood feeding. The mechanisms of the process and molecules involved in the salivary gland invasion remain largely unknown. To establish a robust salivary gland‐specific transgene expression in Anopheles stephensi, we obtained a salivary gland‐specific promoter for a gene encoding anopheline antiplatelet protein (AAPP). The aapp promoter is a female salivary gland‐specific and blood meal‐inducible strong promoter. Using this promoter, we generated a transgenic An. stephensi expressing abundant Discosoma sp. red fluorescent protein (DsRed) in the distal‐lateral lobes of the glands, where the sporozoites invade preferentially. These results open up the possibilities of elucidating salivary gland–parasite interactions and generating transgenic mosquitoes refractory to parasites.
Characterization of BGTG‐1, a tergal gland‐secreted alpha‐amylase, from the German cockroach, Blattella germanica (L.)
Authors: Saltzmann K. D. , Saltzmann K. A. , Neal J. J. , Scharf M. E. , Bennett G. W.
Published: August 2006

The protein fraction of the German cockroach, Blattella germanica (L.), tergal gland secretion was examined. SDS–PAGE separation of proteins present in B. germanica tergal gland secretion revealed a tergal gland‐secreted protein, BGTG‐1, at ≈ 63 kDa. BGTG‐1 first appeared in tergal gland secretion at 2 days postimaginal moult and the amount of protein observed increased through day 5. A 2051 bp cDNA sequence, bgtg‐1, was obtained by RACE polymerase chain reaction and contains a 1494 bp ORF encoding a predicted protein of 498 amino acids. In a Northern hybridization experiment using total RNA from B. germanica tergal gland tissue, a 32P‐labelled bgtg‐1 probe hybridized to an RNA ≈ 2000 bp and confirmed the 2051 bp cDNA size obtained by RACE PCR. Using the BLASTx sequence similarity search tool, the top match to the bgtg‐1 ORF was found to be an α‐amylase from Drosophila kikkawai (e‐value = 1 × 10−178). Alignment of the bgtg‐1 deduced protein sequence with α‐amylases from fruit fly, Drosophila melanogaster, honey bee, Apis mellifera (L.) and yellow mealworm, Tenebrio molitor (L.), revealed conserved residues throughout the ORF and sequence identities ranging from 58.4 to 58.2%. Using a gel‐based assay, degradation of starch by native BGTG‐1 was demonstrated in vitro and we propose that BGTG‐1 may be involved in processing phagostimulatory sugars present in B. germanica tergal gland secretion.
piggyBac‐like elements in the tobacco budworm, Heliothis virescens (Fabricius)
Authors: Wang J. , Ren X. , Miller T. A. , Park Y.
Published: August 2006

We identified two different groups of piggyBac‐like elements (PLE) in the tobacco budworm, Heliothis virescens, and named them HvPLE1 and HvPLE2. An intact copy of HvPLE1 revealed the characteristics of PLE: inverted terminal repeats, inverted subterminal repeats, and an open reading frame encoding transposase, whereas other HvPLE1 copies and all the HvPLE2 copies carried disruptive mutations in the region encoding transposase. We also identified none to two bands per genome hybridized to a probe of Trichoplusia ni piggyBac in genomic Southern blotting, which are different from HvPLE1 or HvPLE2. Analysis of the sequences of multiple copies of HvPLE1 and HvPLE2 suggests that the PLEs are closely related to the T. ni piggyBac, of relatively young age, and independently entered the H. virescens genome.
Germ‐line transformation and RNAi of the ladybird beetle, Harmonia axyridis
Authors: Kuwayama H. , Yaginuma T. , Yamashita O. , Niimi T.
Published: August 2006

To elucidate the molecular mechanisms underlying the tremendous diversity of insect wing colour patterns, it is imperative to identify and functionally characterize the genes involved in this developmental process. Here we report the first successful germ‐line transformation using the transposable element vector piggyBac in the ladybird beetle Harmonia axyridis, which demonstrates typical genetic polymorphism in its wing colour patterns. The transformation efficiency by piggyBac was 3.7% per fertile G0. We investigated the effectiveness of RNAi in Harmonia by injecting EGFP (enhanced green fluorescent protein) dsRNA into early transgenic EGFP‐expressing embryos and observed substantial reduction of EGFP fluorescence in 87.2% of hatched larvae. Application of these new genetic tools to non‐model insects such as Harmonia will facilitate the broad understanding of developmental mechanisms and evolutionary processes that are inaccessible using established model systems.
‘Suicide’ of crickets harbouring hairworms: a proteomics investigation
Authors: Biron D. G. , Ponton F. , Marché L. , Galeotti N. , Renault L. , Demey‐Thomas E. , Poncet J. , Brown S. P. , Jouin P. , Thomas F.
Published: August 2006

Despite increasing evidence of host phenotypic manipulation by parasites, the underlying mechanisms causing infected hosts to act in ways that benefit the parasite remain enigmatic in most cases. Here, we used proteomics tools to identify the biochemical alterations that occur in the head of the cricketNemobius sylvestriswhen it is driven to water by the hairwormParagordius tricuspidatus. We characterized host and parasite proteomes during the expression of the water‐seeking behaviour. We found that the parasite produces molecules from the Wnt family that may act directly on the development of the central nervous system (CNS). In the head of manipulated cricket, we found differential expression of proteins specifically linked to neurogenesis, circadian rhythm and neurotransmitter activities. We also detected proteins for which the function(s) are still unknown. This proteomics study on the biochemical pathways altered by hairworms has also allowed us to tackle questions of physiological and molecular convergence in the mechanism(s) causing the alteration of orthoptera behaviour. The two hairworm species produce effective molecules acting directly on the CNS of their orthoptera hosts.
Differences in Ichthyophonus prevalence and infection severity between upper Yukon River and Tanana River chinook salmon, Oncorhynchus tshawytscha (Walbaum), stocks
Authors: Kocan R , Hershberger P
Published: August 2006

Two genetically distinct populations of chinook salmon, Oncorhynchus tshawytscha (Walbaum), were simultaneously sampled at the confluence of the Yukon and Tanana rivers in 2003. Upper Yukon‐Canadian fish had significantly higher infection prevalence as well as more severe infections (higher parasite density in heart tissue) than the lower Yukon‐Tanana River fish. Both populations had migrated the same distance from the mouth of the Yukon River at the time of sampling but had significantly different distances remaining to swim before reaching their respective spawning grounds. Multiple working hypotheses are proposed to explain the differences between the two stocks: (1) the two genetically distinct populations have different inherent resistance to infection, (2) genetically influenced differences in feeding behaviour resulted in temporal and/or spatial differences in exposure, (3) physiological differences resulting from different degrees of sexual maturity influenced the course of disease, and (4) the most severely infected Tanana River fish either died en route or fatigued and were unable to complete their migration to the Tanana River, thus leaving a population of apparently healthier fish.
The regulation of masticatory function and food bolus formation
Authors: WODA A. , MISHELLANY A. , PEYRON M‐A.
Published: August 2006

summary  This review emphasizes the following points:

1 The values of the physiological parameters of mastication (number of cycles and total electromyographic activity in the sequence, sequence duration, cycle frequency in the sequence, kinetic characteristics of the cycles) are characteristic of each individual and vary widely from one individual to another. In a given individual their modification reflects an adaptation of mastication to the size of the food bolus, and the hardness and rheological characteristics of the food.

2 The ready‐to‐swallow food boluses produced by different individuals nevertheless display similar particle size distributions.

3 Ageing entails adaptation of the masticatory function and does not impair swallowing.

4 Observed increase in total electromyographic activity shows that more energy is expended in mastication by full denture wearers. Despite this increased muscle activity, loss of teeth, even if compensated for by complete dentures, hinders the formation of a normal bolus. The food boluses made by denture wearers thus contain many large‐size particles. The impaired mastication observed in denture wearers approaches the masticatory disabilities found in persons with neuromotor deficiencies.
Oral susceptibility of South African stock‐associated Culicoides species to bluetongue virus
Authors: VENTER G. J. , MELLOR P. S. , PAWESKA J. T.
Published: August 2006

Abstract Field‐collected South African Culicoides species (Diptera, Ceratopogonidae) were fed on sheep blood containing bluetongue virus (BTV) represented by 13 low‐passage reference serotypes: ‐1, ‐2, ‐4, ‐6, ‐7, ‐8, ‐9, ‐10, ‐11, ‐12, ‐13, ‐16 and ‐19. After 10 days of extrinsic incubation at 23.5°C, of the 13 serotypes used, seven were recovered from C. (Avaritia) imicola Kieffer and 11 from C. (A.) bolitinos Meiswinkel. Virus recovery rates and the mean titres for most serotypes were significantly higher in C. bolitinos than in C. imicola. In addition, BTV was recovered from three non‐Avaritia Culicoides species, namely C. (Remmia) enderleini Cornet & Brunhes (BTV‐9), C. (Hoffmania) milnei Austen (BTV‐4) and C. (H.) zuluensis de Meillon (BTV‐16). No virus could be recovered from 316 individuals representing a further 14 Culicoides species. In Culicoides species fed on blood containing similar or identical virus titres of distinct BTV serotypes, significant differences were found in virus recovery rates. The results of this study confirm the higher vector competence of C. bolitinos compared with C. imicola.
Proteomic and microarray characterization of the AggR regulon identifies a pheU pathogenicity island in enteroaggregative Escherichia coli
Authors: Dudley Edward G. , Thomson Nicholas R. , Parkhill Julian , Morin Nicholas P. , Nataro James P.
Published: August 2006

Enteroaggregative Escherichia coli (EAEC) is defined by aggregative adherence (AA) to HEp‐2 cells, where bacteria display adherence to cell surfaces and also to the intervening substratum in a stacked‐brick configuration. We previously showed that an AraC homologue designated AggR is required for the expression of plasmid‐encoded genes that mediate AA of EAEC strain 042. In this study, we hypothesized that AggR also controls the expression of other virulence determinants in EAEC 042. Using proteomic and microarray analysis, we identified for the first time that AggR activates the expression of chromosomal genes, including 25 contiguous genes (aaiA–Y), which are localized to a 117 kb pathogenicity island (PAI) inserted at pheU. Many of these genes have homologues in other Gram‐negative bacteria and were recently proposed to constitute a type VI secretion system (T6SS). AaiC was identified as a secreted protein that has no apparent homologues within GenBank. EAEC strains carrying in‐frame deletions of aaiB, aaiG, aaiO or aaiP still synthesized AaiC; however, AaiC secretion was abolished. Cloning of aai genes into E. coli HB101 suggested that aaiA–P are sufficient for AaiC secretion. A second T6SS was identified within the pheU PAI that secretes a protein unrelated by sequence identity to AaiC. Distribution studies indicated that aaiA and aaiC are commonly found in EAEC isolates worldwide, particularly in strains defined as typical EAEC. These data support the hypothesis that AggR is a global regulator of EAEC virulence determinants, and builds on the hypothesis that T6SS is an importance mediator of pathogenesis.
Lipid domains in bacterial membranes
Authors: Matsumoto Kouji , Kusaka Jin , Nishibori Ayako , Hara Hiroshi
Published: August 2006

The recent development of specific probes for lipid molecules has led to the discovery of lipid domains in bacterial membranes, that is, of membrane areas differing in lipid composition. A view of the membrane as a patchwork is replacing the assumption of lipid homogeneity inherent in the fluid mosaic model of Singer and Nicolson (Science 1972, 175: 720–731). If thus membranes have complex lipid structure, questions arise about how it is generated and maintained, and what its function might be. How do lipid domains relate to the functionally distinct regions in bacterial cells as they are identified by protein localization techniques? This review assesses the current knowledge on the existence of cardiolipin (CL) and phosphatidylethanolamine (PE) domains in bacterial cell membranes and on the specific cellular localization of certain membrane proteins, which include phospholipid synthases, and discusses possible mechanisms, both chemical and physiological, for the formation of the lipid domains. We propose that bacterial membranes contain a mosaic of microdomains of CL and PE, which are to a significant extent self‐assembled according to their respective intrinsic chemical characteristics. We extend the discussion to the possible relevance of the domains to specific cellular processes, including cell division and sporulation.
Accumulation of genome‐specific transcripts, transcription factors and phytohormonal regulators during early stages of fiber cell development in allotetraploid cotton
Authors: Samuel Yang S. , Cheung Foo , Lee Jinsuk J. , Ha Misook , Wei Ning E. , Sze Sing‐Hoi , Stelly David M. , Thaxton Peggy , Triplett Barbara , Town Christopher D. , Jeffrey Chen Z.
Published: August 2006

Gene expression during the early stages of fiber cell development and in allopolyploid crops is poorly understood. Here we report computational and expression analyses of 32 789 high‐quality ESTs derived from Gossypium hirsutum L. Texas Marker‐1 (TM‐1) immature ovules (GH_TMO). The ESTs were assembled into 8540 unique sequences including 4036 tentative consensus sequences (TCs) and 4504 singletons, representing approximately 15% of the unique sequences in the cotton EST collection. Compared with approximately 178 000 existing ESTs derived from elongating fibers and non‐fiber tissues, GH_TMO ESTs showed a significant increase in the percentage of genes encoding putative transcription factors such as MYB and WRKY and genes encoding predicted proteins involved in auxin, brassinosteroid (BR), gibberellic acid (GA), abscisic acid (ABA) and ethylene signaling pathways. Cotton homologs related to MIXTA, MYB5, GL2 and eight genes in the auxin, BR, GA and ethylene pathways were induced during fiber cell initiation but repressed in the naked seed mutant (N1N1) that is impaired in fiber formation. The data agree with the known roles of MYB and WRKY transcription factors in Arabidopsis leaf trichome development and the well‐documented phytohormonal effects on fiber cell development in immature cotton ovules cultured in vitro. Moreover, the phytohormonal pathway‐related genes were induced prior to the activation of MYB‐like genes, suggesting an important role of phytohormones in cell fate determination. Significantly, AA sub‐genome ESTs of all functional classifications including cell‐cycle control and transcription factor activity were selectively enriched in G. hirsutum L., an allotetraploid derived from polyploidization between AA and DD genome species, a result consistent with the production of long lint fibers in AA genome species. These results suggest general roles for genome‐specific, phytohormonal and transcriptional gene regulation during the early stages of fiber cell development in cotton allopolyploids.
Peroxidase‐dependent apoplastic oxidative burst in Arabidopsis required for pathogen resistance
Authors: Bindschedler Laurence V. , Dewdney Julia , Blee Kris A. , Stone Julie M. , Asai Tsuneaki , Plotnikov Julia , Denoux Carine , Hayes Tezni , Gerrish Chris , Davies Dewi R. , Ausubel Frederick M. , Paul Bolwell G.
Published: August 2006

The oxidative burst is an early response to pathogen attack leading to the production of reactive oxygen species (ROS) including hydrogen peroxide. Two major mechanisms involving either NADPH oxidases or peroxidases that may exist singly or in combination in different plant species have been proposed for the generation of ROS. We identified an Arabidopsis thaliana azide‐sensitive but diphenylene iodonium‐insensitive apoplastic oxidative burst that generates H2O2 in response to a Fusarium oxysporum cell‐wall preparation. Transgenic Arabidopsis plants expressing an anti‐sense cDNA encoding a type III peroxidase, French bean peroxidase type 1 (FBP1) exhibited an impaired oxidative burst and were more susceptible than wild‐type plants to both fungal and bacterial pathogens. Transcriptional profiling and RT‐PCR analysis showed that the anti‐sense (FBP1) transgenic plants had reduced levels of specific peroxidase‐encoding mRNAs, including mRNAs corresponding to Arabidopsis genes At3g49120 (AtPCb) and At3g49110 (AtPCa) that encode two class III peroxidases with a high degree of homology to FBP1. These data indicate that peroxidases play a significant role in generating H2O2 during the Arabidopsis defense response and in conferring resistance to a wide range of pathogens.
Growth responses of soybean (Glycine max) and sorghum (Sorghum bicolor) to an increase in density of Amaranthus dubius (L.) plants at two temperatures
Authors: WULFF RENATA D.
Published: August 2006

Plants of soybean (Glycine max) and sorghum (Sorghum bicolor) were grown either alone or in combination with 1, 2, 4, 8 and 16 Amaranthus dubius plants per pot in controlled environment chambers at 31/24 and 25/18°C day/night temperatures. Above‐ground dry weights, leaf areas and heights were measured at 17 and 35 days after planting. Growth of both species increased with temperature. At the second harvest, at both temperatures, even one A. dubius plant per pot had a significant effect on growth of the crop species, and the effects of the two highest densities were equivalent. Shoot dry weights of A. dubius plants were significantly lower when grown with soybean than with sorghum at the same conditions. Linear regressions showed that the dry weights of the crop species were more highly correlated with biomass than with numbers of the interfering weeds, and suggest that soybean may be more affected by an increase in abundance of A. dubius than is sorghum.
Endocrine disrupters – potential modulators of the immune system and allergic response
Authors: Chalubinski M. , Kowalski M. L.
Published: August 2006

Endocrine disrupters (EDs) are environmental pollutants of industrial or agricultural origin (e.g. herbicides, fungicides, insecticides, industrial chemicals) that may influence health of wildlife and human. Endocrine‐disrupting effect is obtained by mimicking the action of the steroid hormones and has been associated with several reproductive disorders as well as cancerogenesis both in animals and humans. EDs can also influence synthesis of cytokines, immunoglobulins, and cell mediators as well as immune cell activation and survival. Modulation by EDs of interleukin‐4 production, Th1/Th2 balance and IgE production suggest their potential effect on allergic immune responses. The aim of this review was to summarize data indicating a potential effect of EDs exposure on the immune system and allergic responses.
The prescriptions frequencies and patterns of Chinese herbal medicine for allergic rhinitis in Taiwan
Authors: Kung Y. Y. , Chen Y. C. , Hwang S. J. , Chen T. J. , Chen F. P.
Published: August 2006

Background:  The evaluation of Chinese herbal medicines (CHM) to allergic rhinitis (AR) by large‐scale pharmaco‐epidemiological study is not ease found, although CHM had been reported to have potential effect for AR in some clinical trials.

Aims of the study:  To explore the frequency and pattern of CHM prescriptions on AR, we have the study by analysing the population‐based CHM database in Taiwan.

Methods:  The way for this study was linked and processed the complete traditional Chinese medicine database for Taiwanese recorded in the year 2002. The diagnosis of AR was extracted with the only single ICD‐9 Code of 477 to calculate the frequency and pattern of prescriptions. Association rule was applied to analyse co‐prescription of CHM for patients with AR.

Results:  In the year 2002, among the 22 520 776 valid beneficiaries of the National Health Insurance, Taiwan, 914 612 subjects (3.8% of the total valid beneficiaries) have diagnosed AR. There were 35.6% of AR patients been treated by CHM. The peak age of AR patients treated by CHM was at the first decade (0–10). For the AR patients, the most common Chinese herbal formula prescription was Shin‐yi‐qing‐fei‐tang, or Angelica dahurica (Bai‐zhi) for the single Chinese herb. While for the combination treatments the most common prescription was the two formulae, Xiao‐qing‐long‐tang and Shin‐yi‐san.

Conclusions:  Because of the high utilization rate of the CHM treatment for AR, a large‐scale randomized trial warrants further research for its efficacy and safety.
Additive partitioning of rarefaction curves and species–area relationships: unifying α‐, β‐ and γ‐diversity with sample size and habitat area
Authors: Crist Thomas O. , Veech Joseph A.
Published: August 2006

Additive partitioning of species diversity is widely applicable to different kinds of sampling regimes at multiple spatial and temporal scales. In additive partitioning, the diversity within and among samples (α and β) is expressed in the same units of species richness, thus allowing direct comparison of α and β. Despite its broad applicability, there are few demonstrated linkages between additive partitioning and other approaches to analysing diversity. Here, we establish several connections between diversity partitions and patterns of habitat occupancy, rarefaction, and species–area relationships. We show that observed partitions of species richness are equivalent to sample‐based rarefaction curves, and expected partitions from randomization tests are approximately equivalent to individual‐based rarefaction. Additive partitions can also be applied to species–area relationships to determine the relative contributions of factors influencing the β‐diversity among habitat fragments.
Mutation accumulation in space and the maintenance of sexual reproduction
Authors: Salathé Marcel , Salathé Rahel , Schmid‐Hempel Paul , Bonhoeffer Sebastian
Published: August 2006

The maintenance of sexual reproduction remains one of the major puzzles of evolutionary biology, since, all else being equal, an asexual mutant should have a twofold fitness advantage over the sexual wildtype. Most theories suggest that sex helps either to purge deleterious mutations, or to adapt to changing environments. Both mechanisms have their limitations if they act in isolation because they require either high genomic mutation rates or very virulent pathogens, and it is therefore often thought that they must act together to maintain sex. Typically, however, these theories have in common that they are not based on spatial processes. Here, we show that local dispersal and local competition can explain the maintenance of sexual reproduction as a means of purging deleterious mutations. Using a spatially explicit individual‐based model, we find that even with reasonably low genomic mutation rates and large total population sizes, asexual clones cannot invade a sexual population. Our results demonstrate how spatial processes affect mutation accumulation such that it can fully erode the twofold benefit of asexuality faster than an asexual clone can take over a sexual population. Thus, the cost of sex is generally overestimated in models that ignore the effects of space on mutation accumulation.
Expression of Bacillus thuringiensis Cry1Ac protein in cotton plants, acquisition by pests and predators: a tritrophic analysis
Authors: Torres Jorge B. , Ruberson John R. , Adang Michael J.
Published: August 2006

1. Studies have shown that Cry proteins of the bacterium Bacillus thuringiensis expressed in transgenic plants can be acquired by nontarget herbivores and predators. A series of studies under field and controlled conditions was conducted to investigate the extent to which Cry1Ac protein from Bt transgenic cotton reaches the third trophic level and to measure the amount of protein that herbivores can acquire and expose to predators.

2. Levels of Cry1Ac in Bt cotton leaves decreased over the season. Among herbivores (four species), Cry1Ac was detected in lepidopteran larvae and the amount varied between species. Among predators (seven species), Cry1Ac was detected in Podisus maculiventris and Chrysoperla rufilabris.

3. In the greenhouse, only 14% of the Cry1Ac detected in the prey (Spodoptera exigua larvae) was subsequently found in the predator P. maculiventris. Detection of Cry1Ac protein in Orius insidiosus, Geocoris punctipes and Nabis roseipennis was probably limited by the amount of prey consumed that had fed on Bt cotton.

4. Purified Cry1Ac was acquired by the small predatory bug G. punctipes but at much higher concentration than found in plants or in lepidopteran larvae.

5. Bt protein was shown to move through prey to the third trophic level. Predatory heteropterans acquired Cry1Ac from prey fed Bt cotton, but acquisition was dependent on the concentration of Cry1Ac conveyed by the prey and the amount of prey consumed. The type and availability of prey capable of acquiring the protein, coupled with the generalist feeding behaviour of the most common predators in the cotton ecosystem, probably constrain the flow of Cry1Ac through trophic levels.
Interactions among fire, insects and pathogens in coniferous forests of the interior western United States and Canada
Authors: Parker Thomas J. , Clancy Karen M. , Mathiasen Robert L.
Published: August 2006

1 Natural and recurring disturbances caused by fire, native forest insects and pathogens have interacted for millennia to create and maintain forests dominated by seral or pioneering species of conifers in the interior regions of the western United States and Canada.

2 Changes in fire suppression and other factors in the last century have altered the species composition and increased the density of trees in many western forests, leading to concomitant changes in how these three disturbance agents interact.

3 Two‐ and three‐way interactions are reviewed that involve fire, insects and pathogens in these forests, including fire‐induced pathogen infection and insect attack, the effects of tree mortality from insects and diseases on fuel accumulation, and efforts to model these interactions.

4 The emerging concern is highlighted regarding how the amount and distribution of bark beetle‐caused tree mortality will be affected by large‐scale restoration of these fire‐adapted forest ecosystems via prescribed fire.

5 The effects of fire on soil insects and pathogens, and on biodiversity of ground‐dwelling arthropods, are examined.

6 The effects of fire suppression on forest susceptibility to insects and pathogens, are discussed, as is the use of prescribed fire to control forest pests.
A new minimally invasive technique for treating radiation cystitis: the argon‐beam coagulator
Authors: WINES MICHAEL P. , LYNCH WILLIAM D.
Published: August 2006

OBJECTIVE

To assess the effectiveness of the argon‐beam coagulator used endoscopically for treating radiation cystitis, as radiotherapy is commonly used for treating pelvic tumours of urological origin, but intractable bleeding related to radiation cystitis remains a serious complication and requires a difficult long‐term follow‐up, for which cystoscopic methods of management have traditionally had limited success.

PATIENTS AND METHODS

We assessed seven patients with radiation cystitis; they were treated with argon‐beam coagulation after a cystoscopic evaluation.

RESULTS

With a mean follow‐up of 15 months, one treatment was used in six patients, with a second treatment required in one.

CONCLUSION

The argon‐beam coagulator appears to be a safe, well tolerated and minimally invasive treatment in patients with radiation cystitis.
Selective nuclear factor κ‐B inhibitors, pyrolidium dithiocarbamate and sulfasalazine, prevent the nephrotoxicity induced by gentamicin
Authors: TUGCU VOLKAN , OZBEK EMIN , TASCI ALI I. , KEMAHLI ERAY , SOMAY ADNAN , BAS MUZAFFER , KARACA CETIN , ALTUG TUNCAY , ÇEKMEN MUSTAFA B. , ÖZDOGAN HACI K.
Published: August 2006

OBJECTIVE

To investigate the effect of selective nuclear factor κ‐B (NFκ‐B) inhibitors, pyrolidium dithiocarbamate (PD) and sulfasalazine (SZ) on renal tubular necrosis and inducible nitric oxide synthase (iNOS) and NFκ‐B expression induced by gentamicin in rats.

MATERIALS AND METHODS

In all, 48 adult male Sprague‐Dawley rats were divided into six equal groups; group 1, control; group 2, injected with gentamicin for 10 days (100 mg/kg/day, intraperitoneal, i.p.); group 3, injected with gentamicin plus PD (100 mg/kg/day, i.p.); group 4, injected with gentamicin plus SZ (75 mg/kg/day, i.p.); group 5, injected with gentamicin plus distilled water (vehicle for PD); and group 6, injected with gentamicin plus ammonium hydroxide (75 mg/day, 1 m, vehicle for SZ) for 10 days. At 24 h after the last injection, rats were killed and the renal cortex separated from the medulla. A small sample was fixed in formaldehyde solution for histological and immunohistochemical examination. Blood samples were also taken to assess the serum levels of urea, creatinine, Na+, K+ and γ‐glutamyl transpeptidase (GT). Crude extracts of the cortex were used to determine reduced glutathione (GSH‐Px), NO and malondialdehyde (MDA). Immunohistochemically, iNOS and the active subunit of NFκB, P65, were evaluated using mouse monoclonal antibodies.

RESULTS

On haematoxylin and eosin staining, compared with the controls rats, gentamicin caused widespread tubular necrosis (grade 3 and 4) but in group 3 and 4 there was a marked reduction in the extent of tubular damage. Immunohistochemically there was more marked staining for iNOS and P65 expression in rats given gentamicin than in the control and group 3 and 4 (P < 0.001). In groups 3 and 4 iNOS and P65 expression were significantly less than in rats given only gentamicin. There was no significant difference in serum levels of Na+, K+, blood urea nitrogen and creatinine. Compared with control rats, gentamicin caused hyperproteinuria, a marked increase in levels of serum γ‐GT, MDA and NO, and a decrease in GSH‐Px (P < 0.001).

CONCLUSION

These results indicate that gentamicin induces iNOS expression through activation of NFκ‐B (P65). It is possible to prevent gentamicin‐induced nephrotoxicity using selective NFκ‐B inhibitors.
Lower urinary tract symptoms and related help‐seeking behaviour in South Asian men living in the UK
Authors: TAYLOR JOBY , MCGROTHER CATHERINE W. , HARRISON SIMON C.W. , ASSASSA PHILIP R. ,   THE LEICESTERSHIRE MRC INCONTINENCE STUDY TEAM
Published: August 2006

OBJECTIVE

To describe the pattern and prevalence of lower urinary tract symptoms (LUTS) and related help‐seeking behaviour in men of South Asian origin living in the UK, and to compare this to the white population.

SUBJECTS AND METHODS

Data were obtained as part of the Leicestershire MRC Incontinence Study. Community‐dwelling men aged >40 years were sent a postal questionnaire addressing urinary symptoms, bother and help‐seeking. Prevalence rates of self‐reported LUTS were compared on the basis of the Office of Population Censuses and Surveys ethnic classifications. Logistic regression was used to estimate the relative risk of symptoms between groups. Data from 7810 men were included in the analysis.

RESULTS

In all, 409 (5.3%) of the population sample described themselves as Asian; 36.5% of these men described at least one significant LUTS, vs 29.0% of white men. The overall prevalence rates for all storage symptoms were significantly higher in Asian men. Straining to void was the only voiding symptom to show a difference in prevalence between the groups. However, when controlling for age, Asian men were at greater risk for all symptoms except a weak urinary stream. Reported levels of bother and felt need were the same in both population groups, but actual help‐seeking was significantly less in the Asian group. Only 25.0% of Asian men had actively sought help, compared to 53.1% of white men.

CONCLUSION

South Asian men in the UK have a higher risk of experiencing LUTS than white men from the same population. This increase in risk is greatest for storage symptoms. Although levels of bother are the same, South Asian men are less likely to seek help for their symptoms.
Physician‐rated patient preference and patient‐ and partner‐rated preference for tadalafil or sildenafil citrate: results from the Canadian ‘Treatment of Erectile Dysfunction’ observational study
Authors: LEE JAY , POMMERVILLE PETER , BROCK GERALD , GAGNON ROBERT , MEHTA PRAVINSAGAR , KRISDAPHONGS MICHOKE , CHAN MELANIE , CHAN JOHN , DICKSON RUTH
Published: August 2006

OBJECTIVE

To determine physician‐based ratings of patient preference, patient preference, partner preference and physician‐based assessment of the reasons for patient preference for tadalafil or sildenafil citrate (sildenafil) as a treatment for erectile dysfunction (ED) in routine clinical practice. Phosphodiesterase type 5 inhibitors (PDE5i) are effective and well‐tolerated therapies for ED, but patient and partner preferences for these treatments might be determined by many factors, both medical and nonmedical.

PATIENTS AND METHODS

The Treatment of ED (TED) observational trial was a multicentre study conducted in Canada to determine patient and partner preferences for the PDE5i tadalafil or sildenafil in routine clinical practice. Patients who planned to change treatment from tadalafil or sildenafil to the alternative drug were invited to participate in the study. The study duration was 4–12 weeks. At visit 1 (baseline), patient background information was collected. At visit 2, physicians answered the physician‐rated patient‐treatment preference questionnaire, patients answered the treatment preference question (TPQ) and the global assessment question (GAQ), and partners answered the partner TPQ.

RESULTS

The TED study was conducted at 266 sites across Canada and involved 2425 patients who used the allowed study medications, and 295 sexual partners who attended clinic visits. More than 98% of patients completed the study. Responses to the preference questionnaires showed that physician‐rated patient preference, patient preference, and partner preference had a similar pattern preference, with a significantly higher proportion preferring tadalafil over sildenafil regardless of the change in treatment (i.e. sildenafil to tadalafil or tadalafil to sildenafil). Responses to the GAQ showed that nearly 90% of the patients who took either PDE5i said that the treatment had improved erections.

CONCLUSIONS

TED is the first study to assess physician‐based ratings of patient preference, patient preference, and partner preference for tadalafil or sildenafil in a routine clinical practice settings. Most participants preferred tadalafil over sildenafil. Understanding the underlying reasons influencing the preference might improve patient compliance and satisfaction with treatment.
Six‐month‐old infants use analog magnitudes to represent duration
Authors: VanMarle Kristy , Wynn Karen
Published: August 2006

While many studies have investigated duration discrimination in human adults and in nonhuman animals, few have investigated this ability in infants. Here, we report findings that 6‐month‐old infants are able to discriminate brief durations, and, as with other animal species, their discrimination function is characterized by Weber's Law: proportionate difference rather than absolute difference between stimuli determined successful discrimination. Importantly, paralleling results found with nonhuman animals, the Weber function that we found for infants’ discrimination of time is the same as that found for their discrimination of number. Infants discriminated durations of an audiovisual event differing by a 1:2 ratio, but not those differing by a 2:3 ratio, over a range of durations. This suggests that (a) in human as in nonhuman animals, the same mental mechanism may underlie the ability to measure duration as to represent number, and (b) we may share this mental mechanism with other animal species.
Apes' and children's understanding of cooperative and competitive motives in a communicative situation
Authors: Herrmann Esther , Tomasello Michael
Published: August 2006

Chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) (Study 1) and 18‐ and 24‐month‐old human children (Study 2) participated in a novel communicative task. A human experimenter (E) hid food or a toy in one of two opaque containers before gesturing towards the reward's location in one of two ways. In the Informing condition, she attempted to help the subject find the hidden object by simply pointing to the correct container. In the Prohibiting condition, E held out her arm toward the correct container (palm out) and told the subject firmly ‘Don't take this one.’ As in previous studies, the apes were at chance in the Informing condition. However, they were above chance in the new Prohibiting condition. Human 18‐month‐olds showed this same pattern of results, whereas 24‐month‐olds showed the opposite pattern: they were better in the Informing condition than in the Prohibiting condition. In our interpretation, success in the Prohibiting condition requires subjects to understand E's goal toward them and their behavior, and then to make an inference (she would only prohibit if there were something good in there). Success in the Informing condition requires subjects to understand a cooperative communicative motive – which apparently apes and young infants find difficult.
THE PHANTASM OF AESTHETIC AUTONOMY IN WHISTLER'S WORK: TITLING THE WHITE GIRL
Authors: TSUI AILEEN
Published: August 2006

This essay explores how James McNeill Whistler's design and titling of his painting The White Girl (1862) responded to the contradictions between his ideal of aesthetic autonomy and his concern to situate his work in the art markets of London and Paris. Attention to Whistler's ironic deployment of suggestive visual imagery and of titles associated with popular narratives leads to a re‐evaluation of how the painting might have signified for viewers in 1862–3. The essay argues that Whistler negotiated conflicts between aesthetic purity and commercial concerns by designing and titling this canvas to function in different ways for what he posited as distinct audiences: an aesthetically sensitive elite and the general publics in London and Paris. The investigation of Whistler's titling tactics and their implications for his art's position within modernism is extended through analysis of new evidence found in previously unnoticed titular inscriptions on wood engravings after his designs.
UK Competition Policy and Shareholder Value: The Impact of Merger Inquiries
Authors: Arnold Malcolm , Parker David
Published: August 2006

Some previous studies have suggested that competition régimes can destroy shareholder value. This study examines data on 50 mergers in the UK between 1989 and 2002. The study confirms the finding from earlier studies of greater gains to shareholders in target than bidding companies, but does not find evidence supporting overall loss of shareholder value to target company shareholders when a merger is prohibited. It finds evidence that when the regulatory régime is stable and well understood the capital market behaves efficiently in response to new information. However, for a subgroup of the mergers involving companies with a new regulatory régime, where the industry and the stock market had little or no experience with respect to mergers, the capital market operated less efficiently.
ADDITIVE‐INTERACTION MODELS OF SPATIAL AGGLOMERATION*
Authors: Fujita Masahisa , Smith Tony E.
Published: August 2006

A wide variety of existing models of spatial agglomeration postulate additive‐interaction effects among agents. In this paper, a synthesis of such models is achieved by establishing certain mathematical equivalences between them. In particular, it is shown that Rockafellar's conjugacy theory of concave functions yields a symmetric one‐to‐one correspondence between three classes of existing models, here designated as spatial‐accessibility models, endogenous‐contact models, and fixed‐contact models. These correspondences not only allow the transference of results between models, but also suggest new economic interpretations of each model in terms of its conjugate model. A series of examples are drawn from the literature to illustrate these results.
Medical and psychosocial outcome of patients with occupational contact dermatitis in Israel
Authors: Lazarov A , Rabin B , Fraidlin N , Abraham D
Published: August 2006

Background  Although the medical, financial and prognostic factors of occupational contact dermatitis (OCD) have been addressed, studies on the social outcome of OCD are sparse.

Objective  To define the medical and psychosocial outcome of patients with OCD.

Methods  Workers with OCD were interviewed by telephone using a questionnaire that included questions about the occupation, dermatological disease, sick leave, present working status and disability claims, and questions related to the subjective perceptions of OCD in all areas of psychosocial functioning and quality of life.

Results  Seventy workers (64.3% males and 35.7% females) were interviewed. Forty per cent had stopped working and one‐third had taken sick leave because of OCD. Forty‐seven (67.1%) were currently working while 23 (32.8%) were unemployed. Disability compensation was claimed by only 41.4% and was received by 24.3%. Eight workers (11.4%) had persistent postoccupational dermatitis (PPOD). Loss of employment affected the occupational area of the workers’ lives (100%), and also interpersonal relationships (45.7%), relationships within the family (18.6%), daily functioning (45.7%) and mental health (24.3%).

Conclusions  Considerable working time is lost because of unemployment or sick leave due to OCD. Only a small proportion of eligible patients with OCD apply for disability compensation and an even smaller proportion receive it. Our study demonstrates the significance of OCD to the psychosocial aspects of workers’ lives and emphasizes that the assessment of OCD outcome should relate not only to the medical but also to the psychosocial aspect of the disease.