bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensory, clinical and physiological factors in sensitive skin: a review
Authors: Farage Miranda A. , Katsarou Alexandra , Maibach Howard I.
Published: June 2006

Certain individuals experience more intense and frequent adverse sensory effects than the normal population after topical use of personal care products, a phenomenon known in popular usage as sensitive skin. Consumer reports of sensitive skin are self‐diagnosed and often not verifiable by objective signs of physical irritation. Companies who manufacture cosmetic and personal care products are challenged to provide safe products to an audience with tremendous differences in skin type, culture and habits. This review examines the still incomplete understanding of this phenomenon with respect to aetiology, diagnosis, appropriate testing methods, possible contributing host factors such as, sex, ethnicity, age, anatomical site, cultural and environmental factors, and the future directions needed for research.
In vivo mutagenicity and initiation following oxidative DNA lesion in the kidneys of rats given potassium bromate
Authors: Umemura Takashi , Kanki Keita , Kuroiwa Yuichi , Ishii Yuji , Okano Keita , Nohmi Takehiko , Nishikawa Akiyoshi , Hirose Masao
Published: June 2006

To clarify the role of 8‐OHdG formation as a starting point for carcinogenesis, we examined the dose‐dependence and time‐course of changes of OGG1 mRNA expression, 8‐OHdG levels and in vivo mutations in the kidneys of gpt delta rats given KBrO3 in their drinking water for 13 weeks. There were no remarkable changes in OGG1 mRNA in spite of some increments being statistically significant. Increases of 8‐OHdG occurred after 1 week at 500 p.p.m. and after 13 weeks at 250 p.p.m. Elevation of Spi− mutant frequency, suggestive of deletion mutations, occurred after 9 weeks at 500 p.p.m. In a two‐stage experiment, F344 rats were given KBrO3 for 13 weeks then, after a 2‐week recovery, treated with 1% NTA in the diet for 39 weeks. The incidence and multiplicity of renal preneoplastic lesions in rats given KBrO3 at 500 p.p.m. followed by NTA treatment were significantly higher than in rats treated with NTA alone. Results suggest that a certain period of time might be required for 8‐OHdG to cause permanent mutations. The two‐step experiment shows that cells exposed to the alteration of the intranuclear status by oxidative stress including 8‐OHdG formation might be able to form tumors with appropriate promotion. (Cancer Sci 2006; 97: 829–835)
Phase II study of the CPT‐11, mitoxantrone and dexamethasone regimen in combination with rituximab in elderly patients with relapsed diffuse large B‐cell lymphoma
Authors: Niitsu Nozomi , Kohuri Mika , Higashihara Masaaki , Bessho Masami
Published: June 2006

Standard treatment for elderly patients with relapsed or refractory DLBCL has not been established. CPT‐11 has a broad spectrum of anticancer activities including a cytotoxic effect in a variety of malignant tumors. The results of combined treatment with CPT‐11 and rituximab have not been reported. The R‐CMD regimen was given to elderly patients with relapsed or refractory DLBCL. The safety and efficacy of this regimen were studied. In addition, the serum nm23‐H1 level was determined to study whether or not it can serve as a prognostic factor. Thirty elderly patients with DLBCL were studied. The main non‐hematological toxicities were infusion‐related adverse events. Grade 3/4 hematological toxicity was seen in 19 patients. Following R‐CMD treatment, the BNP and troponin T levels did not increase. The CR rate was 57%, PR rate was 17%, 2‐year survival rate was 45.2%, and PFS rate was 37.2%. Patients with serum nm23‐H1 levels of higher than 80 ng/mL before the treatment showed significantly poorer prognosis. The serum nm23‐H1 level of the 30 subjects before the treatment was elevated at 39.4 ± 41.3 ng/mL, but it significantly decreased only in the subset of patients who achieved CR. The R‐CMD regimen was safe in elderly patients with DLBCL. No new signs of cardiotoxicity were observed with this regimen. It was also effective in patients with relapsed or refractory DLBCL who had previously used DXR. (Cancer Sci 2006; 97: 933–937)
Involvement of a novel ADP‐ribosylation factor GTPase‐activating protein, SMAP, in membrane trafficking: Implications in cancer cell biology
Authors: Tanabe Kenji , Kon Shunsuke , Natsume Waka , Torii Tetsuo , Watanabe Toshio , Satake Masanobu
Published: June 2006

The endocytosis of cell membrane proteins is initiated by the binding of activated Arf6, a member of Ras‐related GTPases, to the PM. A GAP specific for Arf6 triggers the budding of endocytotic vesicles from the PM by inactivating GTP‐bound Arf6. We recently identified the SMAP gene that encodes an ArfGAP and is involved in the endocytosis of TfnR and possibly E‐cadherin. In this review, we summarize the process of intracellular membrane trafficking, highlighting the roles played by the SMAP gene. Progression of cancer to malignancy occurs in parallel with the disappearance of E‐cadherin, a central component of the adherens junction in epithelial cells. Therefore, elucidation of the molecular mechanism of E‐cadherin endocytosis should be one of the key elements in tumor cell biology. (Cancer Sci 2006; 97: 801–806)
Complementary activation of peripheral natural killer cell immunity in nasopharyngeal carcinoma
Authors: Zheng Ying , Cao Kai‐Yuan , Ng Sze Park , Chua Daniel T.T. , Sham Jonathan S.T. , Kwong Dora L.W. , Ng Mun Hon , Lu Liwei , Zheng Bo‐Jian
Published: June 2006

NK cells and αβ‐ and γδ‐CTL play important roles in cellular immunity against tumors. We previously demonstrated that NPC patients have a quantitative and qualitative deficit in γδ‐CTL and EBV‐specific αβ‐CTL when compared to normal subjects and NPC long‐term survivors. In this study we report further observations of a complementary activation of peripheral NK cells in NPC patients. The NK cells in these patients, compared to those of healthy subjects and NPC survivors, were preferentially activated in response to the stimulation of myeloma cell line XG‐7 and expanded in the presence of exogenous IL‐2. The production of IFN‐γ was lowest in the patient group, whereas IL‐12, IL‐15 and TNF‐α were produced in higher levels in patients than in the donors and survivors. The cytolytic effect of the NK cells against NPC cells in the patient group was also higher than that of the donors and survivors. Furthermore, the patients at later stages of NPC had lower γδ‐CTL activity but higher NK cytotoxicity towards NPC targets, with higher production of IL‐12, IL‐15 and TNF‐α but lower production of IFN‐γ than in patients at earlier stages. This might be part of a triggered compensatory re‐activation of the innate immunity, believed to be mediated through various cytokines and chemokines when adaptive T cell immunity is breached. Together, these data suggest complementary roles of innate and adaptive immune response in tumor immunity where NK cells, γδ‐ and αβ‐CTL compensate for the deficits of one another at different stages of tumor invasion. (Cancer Sci 2006; 97: 912–919)
Synergic antiproliferative effect of DNA methyltransferase inhibitor in combination with anticancer drugs in gastric carcinoma
Authors: Zhang Xiaotian , Yashiro Masakazu , Ohira Masaichi , Ren Jun , Hirakawa Kosei
Published: June 2006

Epigenetic alterations of DNA methylation play an important role in the regulation of gene expression associated with chemosensitivity of gastric carcinomas. With the aim of improving the chemotherapeutic efficacy of gastric carcinoma, the effect of DNA methyltransferase inhibitor, 5‐aza‐CdR, on the chemosensitivity of five anticancer drugs was investigated. Human gastric cancer cell lines, OCUM‐2M and MKN‐74, and five anticancer drugs, 5‐FU, PTX, OXA, SN38, and GEM, were used. In both gastric cancer cell lines, a synergistic antiproliferative effect by a combination of 5‐aza‐CdR at 5 µM was found in SN38 and GEM. 5‐Aza‐CdR at 5 µM increased apoptosis induced by SN38 and GEM in both cell lines. 5‐Aza‐CdR increases the expression of DAPK‐2 and DAPK‐3, RASSF1, and THBS1 genes in both OCUM‐2M and MKN‐74 cells, but not that of hMLH1, p16, MGMT, E‐cadherin, and p53 genes. These findings suggest that 5‐aza‐CdR is a promising chemotherapeutical agent for gastric carcinomas, in combination with the anticancer drugs SN38 and GEM, in apoptosis signaling. The upregulation of DAPK‐2 and DAPK‐3, RASSF1, and THBS1 genes by 5‐aza‐CdR might be associated with the synergistic effect. (Cancer Sci 2006; 97: 938–944)
Melanosis and squamous cell neoplasms of the upper aerodigestive tract in Japanese alcoholic men
Authors: Yokoyama Akira , Mizukami Takeshi , Omori Tai , Yokoyama Tetsuji , Hirota Teruyuki , Matsushita Sachio , Higuchi Susumu , Maruyama Katsuya , Ishii Hiromasa , Hibi Toshifumi
Published: June 2006

Melanosis is frequently observed in the upper aerodigestive tract of Japanese alcoholic men, and the prevalences of squamous cell dysplasia and SCC in the upper aerodigestive tract of Japanese alcoholic men are high. This study evaluated associations between melanosis and both neoplasms of the upper aerodigestive tract and factors contributing to the development of melanosis in Japanese alcoholic men. Endoscopic screening of 643 Japanese alcoholic men (aged 50–79 years) was combined with oropharyngolaryngeal inspection and esophageal iodine staining, and ALDH2 genotyping was carried out in 425 of them. Melanosis was frequently (20.8%) observed in the upper aerodigestive tract. The palate was the most common site of melanosis (11.2%), followed by the pharynx (9.5%), and by the esophagus (7.0%). The incidence of melanosis was higher in those with esophageal dysplasia (31/126, 24.6%), esophageal SCC (19/42, 45.2%), and oropharyngolaryngeal SCC (8/14, 54.1%) than in cancer‐ and dysplasia‐free controls (69/437, 15.8%). The presence of melanosis was associated with a higher risk of esophageal dysplasia, esophageal SCC, and oropharyngolaryngeal SCC (OR 1.69, 4.03, and 6.61, respectively). Multivariate analysis showed that older age, heavier smoking, and heterozygosity for inactive ALDH2 were positively associated with the presence of melanosis. The presence of melanosis indicates a high risk for neoplasms in the upper aerodigestive tract of Japanese alcoholic men. Melanosis and neoplasms have the same causes, including older age, heavy smoking, and high acetaldehyde exposure. (Cancer Sci 2006; 97: 905–911)
Modification by curcumin of mutagenic activation of carcinogenic N‐nitrosamines by extrahepatic cytochromes P‐450 2B1 and 2E1 in rats
Authors: Mori Yukio , Tatematsu Kenjiro , Koide Akihiro , Sugie Shigeyuki , Tanaka Takuji , Mori Hideki
Published: June 2006

To elucidate the mechanism underlying suppression by curcumin of esophageal carcinogenesis induced by NMBA, we evaluated the CYP level and mutagenic activation of environmental carcinogens, by immunoblot analyses and Ames preincubation test, respectively, and bilirubin, 4‐nitrophenol and testosterone UDPGT activities in F344 rats treated with curcumin and/or NMBA. No significant alterations in the hepatic levels of constitutive CYP proteins, mutagenic activation by liver S9 or hepatic UDPGT activities were produced by subcutaneous treatment with 0.5 mg/kg NMBA for 5 weeks and/or feeding of 0.05% and 0.2% curcumin for 6 weeks. In contrast, gavage of 0.2% curcumin decreased esophageal CYP2B1 and 2E1 by up to 60%, compared with vehicle control. Similarly, intragastric treatment with 270 mg/kg curcumin decreased esophageal and gastric CYP2B1 and CYP2E1, but not in lung, kidney or intestine. Conversely, large intestinal CYP2B1 was 2.8‐fold higher in the treated rats than in control rats. Mutagenic activities of NOC, including NMBA, in the presence of esophagus and stomach S9 were markedly decreased in the treated rats, whereas those in the presence of large intestine S9 were 2.2–3.0‐fold above control. These results show that modifying effects of curcumin on esophageal carcinogenesis can be attributed to a decrease in metabolic activation of NMBA by esophageal CYP2B1 during the initiation phase, without the contribution of metabolic activation and inactivation by liver. Further, the present findings suggest the potential of curcumin for modification of gastric and intestinal carcinogenesis initiated with NOC. (Cancer Sci 2006; 97: 896–904)
The energetic equivalence of changing salinity and temperature to juvenile salmon
Authors: WEBSTER S. J. , DILL L. M.
Published: June 2006

The influence of salinity, temperature and physiological development on habitat choice by juvenile salmon is poorly understood. We measured differences in the net energetic cost of habitats that differed in salinity or temperature using behavioural titration of juvenile salmon and correlated these costs with body size and osmoregulatory enzyme activity to quantify how costs change with physiological development.

Juvenile salmon showed a strong preference for saline water (27 or 15 vs 0) and for cold water (9 °C vs 14 °C). It was estimated to be 0·15 W and 0·11 W more costly for salmon to forage in fresh water than in 15 and 27 salt water, respectively, and 0·09 W more costly to forage in warm than in cold water.

We expected fish to prefer 15 salt water to fresh water regardless of enzyme activity because they are iso‐osmotic with this salt concentration. In contrast, preference for higher salt concentrations should increase with enzyme activity. Consistent with our expectations, enzyme activity was not correlated with preference for 15 salt water, but was positively correlated with preference for 27 salt water.

The cost of changing salinity vs changing temperature were very similar, indicating that knowledge of both of these costs are necessary to understand juvenile salmon habitat choice.
Renal morphology, phylogenetic history and desert adaptation of South American hystricognath rodents
Authors: DIAZ G. B. , OJEDA R. A. , REZENDE E. L.
Published: June 2006

To determine whether variation in kidney morphology is associated with environmental aridity in South American hystricognaths, we used conventional and phylogenetic analysis (independent contrasts) to correlate mass‐independent renal variables (kidney size; relative medullar thickness, RMT; medulla/cortex ratio, MC; inner medulla/cortex ratio, MIC; relative medullar area, RMA) with environmental variables such as precipitation, temperature and a measure of primary productivity (NDVI).

Body mass and most renal indexes showed significant phylogenetic signal (the tendency of closely related species to resemble each other), as well as latitude, one index of minimum daily temperature (Tmin) and NDVI, indicating that correcting for phylogenetic effects is necessary, hence results from independent contrasts are more reliable for these traits.

All renal indexes except RMA and MIC were significantly correlated with body mass. After correcting for size effects, inclusion of precipitation or NDVI improved significantly the regression model for kidney size and MIC regardless of the analyses employed, whereas Tmin was also a significant predictor of both indices according to independent contrasts. Precipitation was the best predictor of kidney size, with animals from dryer environments having larger kidneys. RMT was not correlated with any of the environmental indexes employed here.

Our results suggest that hystricognaths from environments with lower rainfall have evolved larger kidneys, probably to cope with aridity. Additional renal indices (RMT, MC and RMA) were not correlated with any environmental variable, and their relative importance as predictors of urine concentration ability for this group of rodents remains unclear.
Does female nuptial coloration reflect egg carotenoids and clutch quality in the Two‐Spotted Goby (Gobiusculus flavescens, Gobiidae)?
Authors: SVENSSON P. A. , PÉLABON C. , BLOUNT J. D. , SURAI P. F. , AMUNDSEN T.
Published: June 2006

Carotenoid‐based ornamentation has often been suggested to signal mate quality, and species with such ornaments have frequently been used in studies of sexual selection.

Female Gobiusculus flavescens (Two‐Spotted Goby) develop colourful orange bellies during the breeding season. Belly coloration varies among mature females, and previous work has shown that nest‐holding males prefer females with more colourful bellies. Because males invest heavily in offspring during incubation, the evolution of this preference can be explained if colourful females provide males with eggs of higher quality.

We tested this hypothesis by allowing males to spawn with ‘colourful’ and ‘drab’ females and comparing parameters including egg carotenoid concentration, clutch size, hatchability and larval viability between groups. We also investigated relationships between egg carotenoid concentration and clutch quality parameters.

Eggs from colourful females had significantly higher concentrations of total carotenoids than drab females, and photographically quantified belly coloration was a good predictor of egg carotenoid concentration.

Colourful females produced slightly larger clutches, but female belly coloration was not related to any measure of clutch quality. In addition, there were no significant relationships between egg carotenoids and clutch quality. Females with high levels of egg carotenoids spawned slightly earlier, however, possibly because they were more ready to spawn or because of male mate choice.

Our results call into question the generality of a causal link between egg carotenoids and offspring quality.
Divergent roles for multiple sexual signals in a polygynous lizard
Authors: MEYERS J. J. , IRSCHICK D. J. , VANHOOYDONCK B. , HERREL A.
Published: June 2006

An unresolved issue in sexual selection concerns the utility of multiple sexual signals that are used simultaneously during displays. We examined male lizards (Urosaurus ornatus) that exhibit two colourful ornaments (throat patch and belly patch) during territorial displays. Populations of Urosaurus ornatus can be polymorphic in throat coloration, and previous studies have shown that the morphs differ in behavioural aggression. We assume that throat coloration correlates with behavioural aggression in our population, as for other populations of U. ornatus.

We show that these different morphs do not differ significantly in morphological shape or bite force, a key aspect of fighting capacity. However, by contrast, the size of the belly patch is a significant predictor of maximum bite force, which is a predictor of dominance in other lizards.

We suggest that belly patch size and throat patch coloration are largely exclusive in that dominant individuals can exhibit small belly patches and low bite forces, whereas subordinate individuals can have large belly patches and high bite forces. Thus, embedded within the same male lizard display are divergent sexual structures that signal different traits, implying that the possession of multiple sexual signals within animals may be favoured by selection.
Flowers adaptively face down‐slope in 10 forest‐floor herbs
Authors: USHIMARU A. , KAWASE D. , IMAMURA A.
Published: June 2006

An animal‐pollinated plant living on a slope should orientate its flowers down‐slope towards the more open space if by doing so it receives more pollinator visits and thereby achieves increased reproductive success.

We measured flower orientation relative to slope direction on individuals of 10 species of forest‐floor herbs in cool temperate forests in Japan. For one of these species, Erythronium japonicum, we also manipulated flower orientation to test experimentally for its effects on both male and female reproductive function.

In all 10 species, flowers were preferentially orientated down‐slope. This pattern was more pronounced in plants growing on steeper slopes.

Our manipulative field experiment in Erythronium japonicum demonstrated that pollen dispatch was highest in flowers orientated down‐slope. Additionally, flowers orientated up‐slope may have achieved a lower seed set on steep slopes.

We conclude that down‐slope orientation of flowers was a general phenomenon among the species that we studied, and that this behaviour was adaptive in enhancing plant fitness through pollination.
Population‐scale drivers of individual arrival times in migratory birds
Authors: GUNNARSSON TÓMAS G. , GILL JENNIFER A. , ATKINSON PHILIP W. , GÉLINAUD GUILLAUME , POTTS PETER M. , CROGER RUTH E. , GUDMUNDSSON GUDMUNDUR A. , APPLETON GRAHAM F. , SUTHERLAND WILLIAM J.
Published: June 2006

In migratory species, early arrival on the breeding grounds can often enhance breeding success. Timing of spring migration is therefore a key process that is likely to be influenced both by factors specific to individuals, such as the quality of winter and breeding locations and the distance between them, and by annual variation in weather conditions before and during migration.

The Icelandic black‐tailed godwit Limosa limosa islandica population is currently increasing and, throughout Iceland, is expanding into poorer quality breeding areas. Using a unique data set of arrival times in Iceland in different years for individuals of known breeding and wintering locations, we show that individuals breeding in lower quality, recently occupied and colder areas arrive later than those from traditionally occupied areas. The population is also expanding into new wintering areas, and males from traditionally occupied winter sites also arrive earlier than those occupying novel sites.

Annual variation in timing of migration of individuals is influenced by large‐scale weather systems (the North Atlantic Oscillation), but between‐individual variation is a stronger predictor of arrival time than the NAO. Distance between winter and breeding sites does not influence arrival times.

Annual variation in timing of migration is therefore influenced by climatic factors, but the pattern of individual arrival is primarily related to breeding and winter habitat quality. These habitat effects on arrival patterns are likely to operate through variation in individual condition and local‐scale density‐dependent processes. Timing of migration thus appears to be a key component of the intricate relationship between wintering and breeding grounds in this migratory system.
Plant size and resprouting ability: trading tolerance and avoidance of damage?
Authors: VESK PETER A.
Published: June 2006

Resprouting has been much studied in mature plants and seedlings, but with little attention to how resprouting ability may change with ontogeny in cross‐species datasets. Because damage exposure and avoidance through large size may differ between growth forms, size‐stage, growth form and disturbance type may interact.

A Bayesian mixed‐effects model was used to analyse a wide‐ranging literature dataset of resprouting responses following clipping or burning. There were distinct ontogenetic patterns of resprouting ability between growth forms. In ground‐dwelling plants, seedling resprouting ability was high and was maintained as plants grew. In trees, survivorship increased with size‐stage. However, for disturbances resulting in stem‐kill, resprouting ability of trees declined with increasing size.

The finding of distinct ontogenetic patterns of sprouting ability between growth forms demonstrates how species trade‐off damage avoidance with resprouting ability to achieve persistence, and provides an example of the life‐history trade‐off of avoidance and tolerance of damage.

Large random effects associated with between‐species variation indicated that although such ontogenetic patterns can be detected, each growth form contains species employing diverse strategies. Bayesian modelling enables flexible and powerful analyses of literature datasets, to reveal diverse strategies often obscured by classical analyses exploring only main effects.
Detecting introgressive hybridization between free‐ranging domestic dogs and wild wolves (Canis lupus) by admixture linkage disequilibrium analysis
Authors: VERARDI A. , LUCCHINI V. , RANDI E.
Published: June 2006

Occasional crossbreeding between free‐ranging domestic dogs and wild wolves (Canis lupus) has been detected in some European countries by mitochondrial DNA sequencing and genotyping unlinked microsatellite loci. Maternal and unlinked genomic markers, however, might underestimate the extent of introgressive hybridization, and their impacts on the preservation of wild wolf gene pools. In this study, we genotyped 220 presumed Italian wolves, 85 dogs and 7 known hybrids at 16 microsatellites belonging to four different linkage groups (plus four unlinked microsatellites). Population clustering and individual assignments were performed using a Bayesian procedure implemented in structure 2.1, which models the gametic disequilibrium arising between linked loci during admixtures, aiming to trace hybridization events further back in time and infer the population of origin of chromosomal blocks. Results indicate that (i) linkage disequilibrium was higher in wolves than in dogs; (ii) 11 out of 220 wolves (5.0%) were likely admixed, a proportion that is significantly higher than one admixed genotype in 107 wolves found previously in a study using unlinked markers; (iii) posterior maximum‐likelihood estimates of the recombination parameter r revealed that introgression in Italian wolves is not recent, but could have continued for the last 70 (± 20) generations, corresponding to approximately 140–210 years. Bayesian clustering showed that, despite some admixture, wolf and dog gene pools remain sharply distinct (the average proportions of membership to wolf and dog clusters were Qw = 0.95 and Qd = 0.98, respectively), suggesting that hybridization was not frequent, and that introgression in nature is counteracted by behavioural or selective constraints.
Tracking factors modulating cytoplasmic incompatibilities in the mosquito Culex pipiens
Authors: DURON OLIVIER , BERNARD CLOTILDE , UNAL SANDRA , BERTHOMIEU ARNAUD , BERTICAT CLAIRE , WEILL MYLÈNE
Published: June 2006

Wolbachia are maternally inherited endosymbiotic bacteria that infect many arthropod species and may induce cytoplasmic incompatibility (CI), resulting in abortive embryonic development. One Wolbachia host, Culex pipiens complex mosquitoes, displays high levels of variability in both CI crossing types (cytotypes) and DNA markers. We report here an analysis of 14 mosquito strains, containing 13 Wolbachia variants, and with 13 different cytotypes. Cytotypes were Wolbachia‐dependent, as antibiotic treatment rendered all strains tested compatible. Cytotype distributions were independent of geographical distance between sampling sites and host subspecies, suggesting that Wolbachia does not promote a reproductive isolation depending on these parameters. Backcross analysis demonstrated a mild restoring effect of the nuclear genome, indicating that CI is mostly cytoplasmically determined for some crosses. No correlation was found between the phenotypic and genotypic variability of 16 WO prophage and transposon markers, except for the WO prophage Gp15 gene, which encodes a protein similar to a bacterial virulence factor. However, Gp15 is partially correlated with CI expression, suggesting that it could be just linked to a CI gene.
Additive effect of teratocyte and calyx fluid from Cotesia plutellae on immunosuppression of Plutella xylostella
Authors: ANDREW NEIL , BASIO M. , KIM YONGGYUN
Published: June 2006

Abstract Teratocytes are cells that originate from the extra‐embryonic tissues of some hymenopteran parasitoids, typically dissociate upon hatching, and develop in the host haemolymph. They are considered to be involved in parasitoid larval nutrient uptake, host immunosuppression and/or repression of competing parasitoid development. Teratocytes of the parasitoid, Cotesia plutellae (Kurdjumov) (Hymenoptera: Braconidae) are found in its natural host, Plutella xylostella (Linnaeus) (Lepidoptera: Yponomeutidae) and can be cultured in vitro. The present study demonstrates that teratocytes of C. plutellae possess a significantly depressive effect on host cellular immunity. When the hosts are preinjected with 200 cultured teratocytes (corresponding to the normal number of teratocytes released during wasp hatching), haemocyte nodulation is inhibited by approximately 40%, with younger teratocytes being more potent than older ones. Similarly, the medium in which teratocytes are cultured has similar immunosuppressive properties. In comparison, calyx fluid extracted from the C. plutellae ovary also has an immunosuppressive effect on P. xylostella. These two maternal (calyx fluid) and embryonic (teratocytes) factors are additive and result in a reduced level of nodule formation equivalent to that induced by natural parasitization. However, the immunosuppression of the parasitized P. xylostella does not appear to be due to inhibition of phospholipase A2, an immune mediator, because injection of arachidonic acid failed to restore haemocyte nodulation capability.
Jasmonic acid signalling and herbivore resistance traits constrain regrowth after herbivore attack in Nicotiana attenuata
Authors: ZAVALA JORGE A. , BALDWIN IAN T.
Published: June 2006

Because traits conferring resistance on herbivores can reduce fitness‐associated traits, trade‐offs may occur between tolerance and resistance responses. We examined these trade‐offs in genotypes of Nicotiana attenuata that were transformed to silence trypsin proteinase inhibitor (TPI) production (AS‐Natpi), an antiherbivore defense associated with (14%) reductions in seed production, and the jasmonate signal cascade that elicits these defenses (AS‐Nalox3), by measuring stalk and axillary branch growth and seed production after two defoliation regimes and Manduca sexta larval attack to bottom or middle and top stalk leaves. Larval attack and defoliation at middle and top leaves depressed seed production and increased axillary branching more than at bottom leaves. AS‐Nalox3 and AS‐Natpi plants produced significantly longer (two‐ to fourfold) branches than did wild‐type (WT) plants, results that are consistent with resource‐based trade‐offs between resistance and regrowth. Methyl jasmonate (MeJA) treatment of AS‐Nalox3 plants restored WT branch growth, suggesting that jasmonic acid (JA) signalling suppresses regrowth and contributes to apical dominance. These results are consistent with the existence of JA‐ and resource‐mediated trade‐offs between regrowth and herbivore resistance traits.
A whole‐tree chamber system for examining tree‐level physiological responses of field‐grown trees to environmental variation and climate change
Authors: MEDHURST JANE , PARSBY JAN , LINDER SUNE , WALLIN GÖRAN , CESCHIA ERIC , SLANEY MICHELLE
Published: June 2006

A whole‐tree chamber (WTC) system was installed at Flakaliden in northern Sweden to examine the long‐term physiological responses of field‐grown 40‐year‐old Norway spruce trees [Picea abies (L.) Karst.] to climate change. The WTCs were designed as large cuvettes to allow the net tree‐level CO2 and water fluxes to be measured on a continuous basis. A total of 12 WTCs were used to impose combinations of atmospheric carbon dioxide concentration, [CO2], and air temperature treatments. The air inside the ambient and elevated [CO2] WTCs was maintained at 365 and 700 µmol mol−1, respectively. The air temperature inside the ambient temperature WTCs tracked air temperature outside the WTCs. Elevated temperatures were altered on a monthly time‐step and ranged between +2.8 and +5.6 °C above ambient temperature. The system allowed continuous, long‐term measurement of whole‐tree photosynthesis, night‐time respiration and transpiration. The performance of the WTCs was assessed using winter and spring data sets. The ability of the WTC system to measure tree‐level physiological responses is demonstrated. All WTCs displayed a high level of control over tracking of air temperatures. The set target of 365 µmol mol−1 in the ambient [CO2] chambers was too low to be maintained during winter because of tree dormancy and the high natural increase in [CO2] over winter at high latitudes such as the Flakaliden site. Accurate control over [CO2] in the ambient [CO2] chambers was restored during the spring and the system maintained the elevated [CO2] target of 700 µmol mol−1 for both measurement periods. Air water vapour deficit (VPD) was accurately tracked in ambient temperature WTCs. However, as water vapour pressure in all 12 WTCs was maintained at the level of non‐chambered (reference) air, VPD of elevated temperature WTCs was increased.
Are ABA, ethylene or their interaction involved in the response of leaf growth to soil water deficit? An analysis using naturally occurring variation or genetic transformation of ABA production in maize
Authors: VOISIN ANNE‐SOPHIE , REIDY BEAT , PARENT BORIS , ROLLAND GAËLLE , REDONDO ELISE , GERENTES DENISE , TARDIEU FRANÇOIS , MULLER BERTRAND
Published: June 2006

The role of abscisic acid (ABA) and its possible interaction with ethylene in mediating leaf elongation response to soil water deficit are a matter of controversy. To address this question, we used a set of maize genotypes with various levels of ABA either due to natural variability or to genetic transformation targeted on NCED/VP14, a key enzyme of ABA synthesis. The transgenic lines yielded less strong phenotypes than available mutants, making it possible to use them under normal growing conditions. We focused on leaf elongation during night periods in order to avoid the confounding effect of ABA on leaf water status. Our results suggest that over a wide range, internal ABA level (measured in both leaf extracts or xylem sap) has no clear effect on leaf elongation response to soil water deficit, except in the case of an antisense line presenting the strongest reduction in ABA accumulation that showed a slight maintenance of leaf elongation during water deficit. Leaf ethylene production rate was variable and not related to water deficit except in the ABA‐deficient transgenic lines where it was increased by water deficit on average but not systematically. Moreover, variability in ethylene production rate was not linked to variability in elongation rate. Our results thus suggest that neither ABA nor ethylene seems to play a major role in the control of leaf elongation response to soil water deficit.
Contrasting patterns of body shape and neutral genetic divergence in marine and lake populations of threespine sticklebacks
Authors: Leinonen T. , Cano J. M. , Mäkinen H. , Merilä J.
Published: June 2006

Comparisons of neutral marker and quantitative trait divergence can provide important insights into the relative roles of natural selection and neutral genetic drift in population differentiation. We investigated phenotypic and genetic differentiation among Fennoscandian threespine stickleback (Gasterosteus aculeatus) populations, and found that the highest degree of differentiation occurred between sea and freshwater habitats. Within habitats, morphological divergence was highest among the different freshwater populations. Pairwise phenotypic and neutral genetic distances among populations were positively correlated, suggesting that genetic drift may have contributed to the morphological differentiation among habitats. On the other hand, the degree of phenotypic differentiation (PST) clearly surpassed the neutral expectation set by FST, suggesting a predominant role for natural selection over genetic drift as an explanation for the observed differentiation. However, separate PST/FST comparisons by habitats revealed that body shape divergence between lake and marine populations, and even among marine populations, can be strongly influenced by natural selection. On the other hand, genetic drift can play an important role in the differentiation among lake populations.
Effects of acute and chronic restraint stress on visceral sensitivity and neuroendocrine hormones in rats
Authors: SUN Yan , LIU Feng Ling , SONG Geng Qing , QIAN Wei , HOU Xiao Hua
Published: June 2006

OBJECTIVE:  To investigate the effects of acute and chronic partial restraint stress (PRS) on visceral sensi‐tivity to colorectal distention and the neuroendocrine response in rats.

METHODS:  Male Sprague–Dawley rats were used in this study. The abdominal withdrawal reflex score was assessed before stress, immediately after acute or chronic PRS, and 7 days after the first stress. The plasma levels of corticosterone (CORT) and adrenocorticotropic hormone (ACTH) were detected by radioimmunoassay at different time points.

RESULTS:  The abdominal withdrawal reflex scores of the rats with acute or chronic PRS were significantly higher immediately after stress than those before and 7 days after the stress (P < 0.05). The levels of CORT (25.35 ±  6.03 ng/mL) and ACTH (312.47 ± 50.76 pg/mL) in rats with acute PRS showed a significant elevation immediately after stress compared to rats without PRS (7.24 ± 2.97 ng/mL, 97.00 ± 23.33 pg/mL, P < 0.05). However, these hormones returned to the baseline value 7 days after acute PRS. The levels of CORT (20.84 ± 2.19 ng/mL) and ACTH (200.41 ± 78.10 pg/mL) in rats with chronic PRS were significantly higher after stress than in rats without PRS (P < 0.05), and these hormones remained elevated 7 days after chronic PRS.

CONCLUSIONS:  Both acute and chronic PRS induce reversible visceral hypersensitivity. Acute PRS transiently elevates the plasma levels of CORT and ACTH, whereas chronic PRS has a longer term effect.
Novel lipids in Myxococcus xanthus and their role in chemotaxis
Authors: Curtis Patrick D. , Geyer Roland , White David C. , Shimkets Lawrence J.
Published: June 2006

Organisms that colonize solid surfaces, like Myxococcus xanthus, use novel signalling systems to organize multicellular behaviour. Phosphatidylethanolamine (PE) containing the fatty acid 16:1ω5 (Δ11) elicits a chemotactic response. The phenomenon was examined by observing the effects of PE species with varying fatty acid pairings. Wild‐type M. xanthus contains 17 different PE species under vegetative conditions and 19 at the midpoint of development; 13 of the 17 have an unsaturated fatty acid at the sn‐1 position, a novelty among Proteobacteria. Myxococcus xanthus has two glycerol‐3‐phosphate acyltransferase (PlsB) homologues which add the sn‐1 fatty acid. Each produces PE with 16:1 at the sn‐1 position and supports growth and fruiting body development. Deletion of plsB1 (MXAN3288) results in more dramatic changes in PE species distribution than deletion of plsB2 (MXAN1675). PlsB2 has a putative N‐terminal eukaryotic fatty acid reductase domain and may support both ether lipid synthesis and PE synthesis. Disruption of a single sn‐2 acyltransferase homologue (PlsC, of which M. xanthus contains five) results in minor changes in membrane PE. Derivatization of purified PE extracts with dimethyldisulfide was used to determine the position of the double bonds in unsaturated fatty acids. The results suggest that Δ5 and Δ11 desaturases may create the double bonds after synthesis of the fatty acid. Phosphatidylethanolamine enriched for 16:1 at the sn‐1 position stimulates chemotaxis more strongly than PE with 16:1 enriched at the sn‐2 position. It appears that the deployment of a rare fatty acid (16:1ω5) at an unusual position (sn‐1) has facilitated the evolution of a novel cell signal.
APPLICATION OF LAPLACE'S BOUNDARY‐MODE APPROXIMATIONS TO ESTIMATE SPECIES AND SHARED SPECIES RICHNESS
Authors: Chao Anne , Shen Tsung‐Jen , Hwang Wen‐Han
Published: June 2006

The Laplace method for approximating integrals is a useful technique in a number of research fields. This paper shows that it also has interesting applications in biological and ecological statistical inferences. When sample abundance or replicated incidence (i.e., presence or absence) records of each species are available, the expected low‐order frequency counts in heterogeneous communities can be approximated by the Laplace method when the species discovery or detection probabilities are bounded from below by a constant. The approximation formulae as applied to one community can then be used to derive estimators of species richness and to examine their performance. The approach is also extended to obtain simple and new estimators for the number of shared species in two communities. The replicated species incidence data recorded by competing teams of the Hong Kong Big Bird Race for the years 1999 and 2000 are used to estimate the number of resident birds in Hong Kong and to illustrate the method of estimation.
BOOTSTRAP TESTS FOR THE ERROR DISTRIBUTION IN LINEAR AND NONPARAMETRIC REGRESSION MODELS
Authors: Neumeyer Natalie , Dette Holger , Nagel Eva‐Renate
Published: June 2006

In this paper we investigate several tests for the hypothesis of a parametric form of the error distribution in the common linear and non‐parametric regression model, which are based on empirical processes of residuals. It is well known that tests in this context are not asymptotically distribution‐free and the parametric bootstrap is applied to deal with this problem. The performance of the resulting bootstrap test is investigated from an asymptotic point of view and by means of a simulation study. The results demonstrate that even for moderate sample sizes the parametric bootstrap provides a reliable and easy accessible solution to the problem of goodness‐of‐fit testing of assumptions regarding the error distribution in linear and non‐parametric regression models.
A BAYESIAN HIERARCHICAL MODEL FOR POISSON RATE AND REPORTING‐PROBABILITY INFERENCE USING DOUBLE SAMPLING
Authors: Stamey James D. , Young Dean M. , Boese Doyle
Published: June 2006

We analyse a combination of errant count data subject to under‐reported counts and inerrant count data to estimate multiple Poisson rates and reporting probabilities of cervical cancer for four European countries. Our analysis uses a Bayesian hierarchical model. Using a simulation study, we demonstrate the efficacy of our new simultaneous inference method and compare the utility of our method with an empirical Bayes approach developed by Fader and Hardie (J. Appl. Statist., 2000).
BAYESIAN SUBSET SELECTION AND MODEL AVERAGING USING A CENTRED AND DISPERSED PRIOR FOR THE ERROR VARIANCE
Authors: Cripps Edward , Kohn Robert , Nott David
Published: June 2006

This article proposes a new data‐based prior distribution for the error variance in a Gaussian linear regression model, when the model is used for Bayesian variable selection and model averaging. For a given subset of variables in the model, this prior has a mode that is an unbiased estimator of the error variance but is suitably dispersed to make it uninformative relative to the marginal likelihood. The advantage of this empirical Bayes prior for the error variance is that it is centred and dispersed sensibly and avoids the arbitrary specification of hyperparameters. The performance of the new prior is compared to that of a prior proposed previously in the literature using several simulated examples and two loss functions. For each example our paper also reports results for the model that orthogonalizes the predictor variables before performing subset selection. A real example is also investigated. The empirical results suggest that for both the simulated and real data, the performance of the estimators based on the prior proposed in our article compares favourably with that of a prior used previously in the literature.
SECOND ORDER ASYMPTOTIC COMPARISON OF ESTIMATORS UNDER UNIVERSAL DOMINATION CRITERION
Authors: Takagi Yoshiji
Published: June 2006

The main purpose of this paper is to formulate theories of universal optimality, in the sense that some criteria for performances of estimators are considered over a class of loss functions. It is shown that the difference of the second order terms between two estimators in any risk functions is expressed as a form which is characterized by a peculiar value associated with the loss functions, which is referred to as the loss coefficient. This means that the second order optimal problem is completely characterized by the value of the loss coefficient. Furthermore, from the viewpoint of change of the loss coefficient, the relationship between two estimators is classified into six types. On the basis of this classification, the concept of universal second order admissibility is introduced. Some sufficient conditions are given to determine whether any estimators are universally admissible or not.
What's to Fear from Immigrants? Creating an Assimilationist Threat Scale
Authors: Paxton Pamela , Mughan Anthony
Published: June 2006

We argue that cultural threat, stressed in recent studies of anti‐immigrant sentiment, is properly measured in the U.S. case as “assimilationist threat”: a resentful perception that immigrants are failing to adopt the cultural norms and lifestyle of their new homeland. We explore the meaning and form of assimilationist threat in the minds of Americans through an analysis of four focus groups, two in Los Angeles, CA, and two in Columbus, OH. Using information from the focus groups, we develop and test a set of survey questions covering three dimensions of immigrants’ commitment to their new country: language, productivity, and citizenship. We produce a summary scale of assimilationist threat that can be used by other researchers seeking to understand the causes and consequences of anti‐immigrant sentiment.
Geographical Frame of Reference and Dangerous Intergroup Attitudes: A Double‐Minority Study in Sri Lanka
Authors: Schaller Mark , Abeysinghe A. M. N. D.
Published: June 2006

An ethnic group can comprise a local majority, but be a minority within a broader geographic region or vice‐versa. This situation has interesting psychological implications that may contribute to intergroup conflict. To test some of these implications, an experiment was conducted in Sri Lanka, during a ceasefire in the conflict between the government and Tamil rebellion forces. Participants were 100 Sinhalese students. An experimental manipulation was introduced to make one of two geographical regions salient: either just Sri Lanka (within which Sinhalese outnumber Tamils) or a broader region of south Asia (within which Sinhalese are outnumbered by Tamils). Following the manipulation, stereotypes and conflict‐relevant attitudes were assessed. Results revealed that when Sinhalese participants were inclined to think of their group as the outnumbered minority, stereotypic perceptions of Tamils were more demonizing (i.e., depicting Tamils as more malevolent and also more competent), and their conflict‐relevant attitudes were less conciliatory. These results have conceptual implications as well as implications for understanding conflict and conflict resolution.
Conflict, Identity, and Tolerance: Israel in the Al‐Aqsa Intifada
Authors: Shamir Michal , Sagiv‐Schifter Tammy
Published: June 2006

This paper explores the impact of the Al‐Aqsa Intifada on tolerance orientations of the Israeli Jewish public. We rely upon five surveys carried out between January 2000 and June 2002 to study in a real‐life setting the amount and nature of change in political tolerance due to the conflict and the mechanisms behind it. Building on theory and research on intergroup relations in social psychology and political tolerance in political science, we focus upon threat and ingroup identification as the two primary factors in the social psychological processes resulting from conflict and leading to intolerance. We set the trends and explore mediation and interaction processes in the impact of this round of conflict on political tolerance.
Media Freedom and Political Debate in the Digital Era
Authors: Rowbottom Jacob
Published: June 2006

This article examines the impact of online expression on theories of media freedom. While media freedom has generally been justified instrumentally, the opportunities for expression via the Internet may require greater emphasis on the interests of the individual speaker. Despite this development, this article shows how a small number of speakers will still command a much wider audience and have greater influence over political debate. For such speakers the approach to media freedom devised in the mass media era will remain applicable.