bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental dietary manipulations for determining the relative importance of allochthonous and autochthonous food resources in tropical streams
Authors: LAU DANNY C. P. , LEUNG KENNETH M. Y. , DUDGEON DAVID 
Published: October 2007

Summary1. Autochthonous sources of organic matter appear to make a minor contribution to food webs in temperate forest streams, but their roles in supporting consumer biomass in tropical lotic environments have received little attention. We investigated the importance of autochthonous and allochthonous food sources to Brotia hainanensis (Pachychilidae), a detritivorous and algivorous snail common in Hong Kong hillstreams, using experimental dietary manipulations and assimilation‐based analyses, including stoichiometry, carbon (C) and nitrogen (N) stable isotopes and fatty acid (FA) profiles.2. Juvenile B. hainanensis collected in Pak Ngau Shek Stream were cultured under controlled laboratory conditions and fed for 2 months with either conditioned Liquidambar formosana (Hamamelidaceae) leaf litter or periphyton. Samples of B. hainanensis were also collected from the stream at the end of the experiment for comparison with snails reared in the laboratory.3. Periphyton and leaf litter exhibited marked differences in C/N ratios, δ13C and δ15N values and FA profiles. Stable isotope analysis and FA profiling of laboratory‐reared and field‐collected B. hainanensis both confirmed that snails relied primarily on autochthonous foods, especially periphytic diatoms and cyanobacteria. Stoichiometry results indicated that periphyton was a more nutritious food (with lower C/N ratio) than leaf litter.4. This is the first study demonstrating that the combined use of stable isotopes and FA profiles is an effective diagnostic tool to trace the basal food sources of consumers in natural stream habitats. Our findings further support the hypothesis that primary production in tropical streams is generally more important to aquatic consumers than inputs of terrestrial detritus.
Do distributional shifts of northern and southern species of algae match the warming pattern?
Authors: LIMA FERNANDO P. , RIBEIRO PEDRO A. , QUEIROZ NUNO , HAWKINS STEPHEN J. , SANTOS ANTÓNIO M. 
Published: October 2007

AbstractWell‐documented changes in species abundances and distributions coinciding with global warming have been increasing during recent years. A trend of raising sea‐surface temperature has also been observed along the Portuguese coast which could affect intertidal species' ranges. The present study aimed at evaluating the direction and intensity of distribution changes of macroalgae in the area. The last 50‐year trend of coastal air and sea temperature was reassessed, providing an accurate estimate of the warming process. Information on species' range shifts was obtained by comparing data from recent resurveys with historical records of algal distributions collected during the 1950s and 1960s. Although a prevalence of northward migrations was anticipated, this work showed a marked difference in the average direction of changes between cold‐ and warm‐water species. Cold‐water species, when considered together, showed no particular shifting trend, because the number of species that shifted north or south was the same. Contrarily, all shifting warm‐water species expanded their range northwards. Therefore, generalizations about poleward range shifts due to increasing temperature should be made with caution.
Simulated global changes alter phosphorus demand in annual grassland
Authors: MENGE DUNCAN N. L. , FIELD CHRISTOPHER B. 
Published: October 2007

AbstractIn the Jasper Ridge Global Change Experiment – an annual grassland with elevated carbon dioxide (CO2), nitrate deposition, temperature, and precipitation – we used six indices of phosphorus (P) limitation to test the hypothesis that global changes that increase net primary production (NPP) increase P demand or limitation. All indices indicated that nitrate deposition, the only factor that stimulated NPP, increased P demand or limitation: (1) soil phosphatase activity increased by 14%; (2) P concentration in green and (3) senescent leaves of the dominant grass genus, Avena, dropped by 40% and 44%, respectively; (4) N : P ratios in green and (5) senescent Avena widened by 99% and 161%, respectively; and (6) total aboveground plant P decreased by 17% with elevated nitrate deposition. The other three factors, which did not stimulate NPP, did not increase P demand: based on two indices, enhanced precipitation decreased P demand (11% decrease in phosphatase activity, 19% increase in total aboveground P), and there was no evidence that elevated CO2 or temperature altered P demand. In a meta‐analysis to assess the generality of P constraints on growth increases from global change factors, we found that six of 11 N‐limited ecosystems responded to N deposition with enhanced P limitation or demand, but did not detect significant effects of elevated CO2 or warming.
Toxicity evaluation of root canal sealers in vitro
Authors: Lodienė G. , Morisbak E. , Bruzell E. , Ørstavik D. 
Published: October 2007

AbstractAim  To compare the toxicity of methacrylate resin‐based root canal sealers with sealers based on epoxy resin and silicone by two‐well established cell culture methods.Methodology  Specimens of AH Plus, EndoREZ, RoekoSeal and Epiphany were prepared for direct contact in the Millipore filter diffusion test and as extracts in the MTT assay. Mouse fibroblasts (L929) were used as toxicity targets. Differences in cytotoxicity between fresh and set specimens and between the extracts of root canal sealers were determined by t‐test (P < 0.05).Results  In the filter diffusion test, freshly mixed Epiphany and AH Plus were rated severely toxic and RoekoSeal and EndoREZ nontoxic. When set, Epiphany was moderately toxic, whereas AH Plus, RoekoSeal and EndoREZ were nontoxic. Epiphany was significantly more toxic than RoekoSeal and EndoREZ (P < 0.05). In the MTT assay with set specimens, Epiphany was rated severely toxic; AH Plus and RoekoSeal slightly toxic; and EndoREZ nontoxic. Epiphany was significantly more toxic than the other three materials in this test (P < 0.001).Conclusion  The multi‐methacrylate resin‐based (Epiphany) root canal sealer was significantly more toxic to L‐929 cells than the silicone‐based Roeko Seal and the single methacrylate‐based EndoREZ root canal sealers. AH Plus showed intermediate toxicity.
The physical properties of accelerated Portland cement for endodontic use
Authors: Camilleri J. 
Published: October 2007

AbstractAim  To investigate the physical properties of a novel accelerated Portland cement.Methodology  The setting time, compressive strength, pH and solubility of white Portland cement (Lafarge Asland; CEM 1, 52.5 N) and accelerated Portland cement (Proto A) produced by excluding gypsum from the manufacturing process (Aalborg White) and a modified version with 4 : 1 addition of bismuth oxide (Proto B) were evaluated.Results  Proto A set in 8 min. The compressive strength of Proto A was comparable with that of Portland cement at all testing periods (P > 0.05). Additions of bismuth oxide extended the setting time and reduced the compressive strength (P < 0.05). Both cements and storage solution were alkaline. All cements tested increased by >12% of their original weight after immersion in water for 1 day with no further absorption after 28 days. Addition of bismuth oxide increased the water uptake of the novel cement (P < 0.05).Conclusions  The setting time of Portland cement can be reduced by excluding the gypsum during the last stage of the manufacturing process without affecting its other properties. Addition of bismuth oxide affected the properties of the novel cement. Further investigation on the effect that bismuth oxide has on the properties of mineral trioxide aggregate is thus warranted.
Dental fear, communication, and behavioural management problems in children referred for dental problems
Authors: KLAASSEN MARLEEN ANTOINETTE , VEERKAMP JACOBUS SIMON JOHANNES , HOOGSTRATEN JOHAN 
Published: October 2007

Background.  Knowledge about the influence of the interaction between child, parent, and dentist and the referral pattern is very limited.Aim.  This study intended to assess to what extent the pathways of Rachman could clarify why a child is being referred to a specialist in paediatric dentistry and if other aspects in the interaction between child, parent, and dentist play a role in the referral.Design.  The referral letters of 500 children referred to a Special Dental Care Centre in Amsterdam were examined. All parents filled out the Children's Fear Survey Schedule–Dental Subscale, on behalf of the child. Information about interaction and the referral was collected from the referral letter and a semistructured interview with the parent and dentist separately.Results.  Eighty pairs of parents and dentists of referred children participated in a semistructured interview. Child factors seem to contribute the most to the referral. For the cause of referral the pathways of Rachman and communication were often combined.Conclusions.  Apart from fear acquisition, as implied in Rachman's pathways, the interaction between child, dentist, and parent also contributes to the referral of a child to a specialist clinic in paediatric dentistry.
Dental fear/anxiety and dental behaviour management problems in children and adolescents: a review of prevalence and concomitant psychological factors
Authors: KLINGBERG GUNILLA , BROBERG ANDERS G. 
Published: October 2007

Objectives.  The objectives of this article were to examine the literature published from 1982 to 2006 and to evaluate prevalence of dental fear and anxiety (DFA) and dental behaviour management problems (DBMP) in children and adolescents, and their relationships to age, sex, general anxiety, temperament, and general behavioural problems.Methods.  A broad search of the PubMed database was performed using three combinations of search terms.Results.  A large proportion of the identified articles could not be used for the review owing to inadequate endpoints, measures or poor study design. Thirty‐two papers of acceptable quality were identified and reviewed. The prevalence of both DFA and DBMP were estimated to 9%, with a decrease in prevalence with age. DFA/DBMP were more frequent in girls. DFA/DBMP were related to general fear and both internalizing and externalizing behavioural problems, although these relationships were not clear‐cut. Temperament was related to both DFA and DBMP but with different temperamental characteristics, while general behavioural problems mainly correlated with DBMP.Conclusions.  DFA/DBMP are common, and several psychological factors are associated with the development of these problems. In order to better understand these relationships, a number of issues concerning design of research and measurement of DFA/DBMP have to be dealt with.
Translation and evaluation of a Chinese version of the Child Oral Health‐related Quality of Life measure
Authors: McGRATH COLMAN , PANG HARRY N. , LO EDWARD C. M. , KING NIGEL M. , HÄGG URBAN , SAMMAN NABIL 
Published: October 2007

Objective.  This study aims to translate and evaluate the performance of a Chinese version of the Child Oral Health‐related Quality of Life (COHQoL©) measure composed of the Child Perception Questionnaire (CPQ), Parental Perception Questionnaire (PPQ), and Family Impact Scale (FIS).Basic research design.  Chinese versions of the measures were derived through a forward–backward translation. A consecutive sample of 168 children attending paediatric dental and orthodontic clinics in Hong Kong were recruited along with their attending primary caregiver. Children self‐completed the 37‐item CPQ and their attending primary caregiver self‐completed the 31‐item PPQ and 14‐item FIS consecutively and independently. Reassessments were conducted prior to their next appointment.Results.  CPQ, PPQ, and FIS scores were associated with children's global rating of oral health (P < 0.05) and oral well‐being (P < 0.05) supporting their construct validity. In addition, variations in CPQ, PPQ, and FIS were apparent with respect to patient group (P < 0.05) supporting their ability to distinguish between patient groups. Cronbach alpha values (internal reliability) and intraclass correlation coefficient values (test–retest reliability) for the three measures were > 0.80.Conclusion.  A Chinese version of the three components of the COHQoL measure was developed with minor modifications. In psychometric testing, the validity of the three components was supported and they demonstrated acceptable reliability.
Hygiene theory and allergy and asthma prevention
Authors: Liu Andrew H. 
Published: October 2007

SummaryEpidemiological trends of allergic diseases and asthma in children reveal a global rise in their prevalence over the past 50 years. Their rapid rise, especially in metropolitan locales, suggests that recent changes in modern environments and/or life styles underlie these trends. One environmental/life style factor that may be contributing to this trend is called the hygiene hypothesis: that naturally occurring microbial exposures in early life may have prompted early immune maturation and prevented allergic diseases and asthma from developing. Subsequently, children raised in modern metropolitan life styles, relatively devoid of this natural microbial burden, may have under‐stimulated immune systems in infancy, thereby allowing for the ‘allergic march’– a pattern of pro‐allergic immune development and disorders that occurs in early life. Over the past 15 years, hygiene theorising has evolved in shape and substance, in part due to a growing and strengthening burden of evidence from epidemiological, translational and basic research. What was speculation may be key clues to allergy and asthma prevention. The objectives of this article are to summarise the epidemiological trends and allergic march of childhood that may be explained by hygiene theory, to overview current hygiene theory paradigms and to exemplify the strengthening epidemiological evidence in support of the hygiene theory, using bacterial endotoxin exposure as a prototypical example.
Prenatal maternal stress and early caregiving experiences: implications for childhood asthma risk
Authors: Wright Rosalind J. 
Published: October 2007

SummaryThere is still much debate as to the pathways through which some children develop asthma and others do not. One possible mechanism outlined here concerns the way in which stress may influence the neuroendocrine system and thence the immune system. Supporting evidence from animal experiments suggests that maternal prenatal stress may be of importance, resulting in programming of the infant's HPA axis. In addition, social stressors during the early part of a child's life may also affect the HPA axis and thence dysregulation of immune system functioning with implications for the development of asthma.
Exceptional paternal inheritance of plastids in Arabidopsis suggests that low‐frequency leakage of plastids via pollen may be universal in plants
Authors: Azhagiri Arun K. , Maliga Pal 
Published: October 2007

SummaryPlastid DNA is absent in pollen or sperm cells of Arabidopsis thaliana. Accordingly, plastids and mitochondria, in a standard genetic cross, are transmitted to the seed progeny by the maternal parent only. Our objective was to test whether paternal plastids are transmitted by pollen as an exception. The maternal parent in our cross was a nuclear male sterile (ms1‐1/ms1‐1), spectinomycin‐sensitive Ler plant. It was fertilized with pollen of a male fertile RLD‐Spc1 plant carrying a plastid‐encoded spectinomycin resistance mutation. Seedlings with paternal plastids were selected by spectinomycin resistance encoded in the paternal plastid DNA. Our data, in general, support maternal inheritance of plastids in A. thaliana. However, we report that paternal plastids are transmitted to the seed progeny in Arabidopsis at a low (3.9 × 10−5) frequency. This observation extends previous reports in Antirrhinum majus, Epilobium hirsutum, Nicotiana tabacum, Petunia hybrida, and the cereal crop Setaria italica to a cruciferous species suggesting that low‐frequency paternal leakage of plastids via pollen may be universal in plants previously thought to exhibit strict maternal plastid inheritance. The genetic tools employed here will facilitate testing the effect of Arabidopsis nuclear mutations on plastid inheritance and allow for the design of mutant screens to identify nuclear genes controlling plastid inheritance.
Transgene‐induced silencing of Arabidopsis phytochrome A gene via exonic methylation
Authors: Chawla Rekha , Nicholson Scott J. , Folta Kevin M. , Srivastava Vibha 
Published: October 2007

SummaryTransgene‐induced promoter or enhancer methylation clearly retards gene activity. While exonic methylation of genes is frequently observed in the RNAi process, only sporadic evidence has demonstrated its definitive role in gene suppression. Here, we report the isolation of a transcriptionally suppressed epi‐allele of the Arabidopsis thaliana phytochrome A gene (PHYA) termed phyA′ that shows methylation only in symmetric CG sites resident in exonic regions. These exonic modifications confer a strong phyA mutant phenotype, characterized by elongated hypocotyls in seedlings grown under continuous far‐red light. De‐methylation of phyA′ in the DNA methyl transferase I (met1) mutant background increased PHYA expression and restored the wild‐type phenotype, confirming the pivotal role of exonic CG methylation in maintaining the altered epigenetic state. PHYA epimutation was apparently induced by a transgene locus; however, it is stably maintained following segregation. Chromatin immunoprecipitation assays revealed association with dimethyl histone H3 lysine 9 (H3K9me2), a heterochromatic marker, within the phyA′ coding region. Therefore, transgene‐induced exonic methylation can lead to chromatin alteration that affects gene expression, most likely through reduction in the transcription rate.
The lithium tolerance of the Arabidopsis cat2 mutant reveals a cross‐talk between oxidative stress and ethylene
Authors: Bueso Eduardo , Alejandro Santiago , Carbonell Pablo , Perez‐Amador Miguel A. , Fayos Joaquín , Bellés Jose M. , Rodriguez Pedro L. , Serrano Ramón 
Published: October 2007

SummaryIn order to investigate the effects of a permanent increase in cellular H2O2 on cation homeostasis we have studied a T‐DNA insertion mutant of the Arabidopsis CATALASE 2 gene. This mutant (cat2‐1) exhibits 20% of wild‐type leaf catalase activity and accumulates more H2O2 than the wild type under normal growth conditions. In addition to reduced size, a pale green color and great reduction in secondary roots, the cat2‐1 mutant exhibited increased sensitivity to H2O2, NaCl, norspermidine, high light and cold stress. On the other hand, the germination of the cat2‐1 mutant is more tolerant to lithium than the wild type. This novel phenotype cannot be explained by changes in lithium transport. Actually, the uptake of lithium (and of other toxic cations such as sodium and norspermidine) is increased in the cat2‐1 mutant while K+ levels were decreased. The lithium tolerance of this mutant seems to result both from insensitivity to the inhibitory ethylene induced by this cation and a reduced capability for ethylene production. Accordingly, induction by ethylene of responsive genes such as PR4 and EBP/ERF72 is decreased in cat2‐1. Mutants insensitive to ethylene such as etr1‐1 and ein3‐3 are lithium tolerant, and inhibition of ethylene biosynthesis with 2‐aminoisobutyrate protects against lithium toxicity. Microarray analysis of gene expression indicates that the expression of genes related to cation transport and ethylene synthesis and perception was not altered in the cat2‐1 mutant, suggesting that H2O2 modulates these processes at the protein level. These results uncover a cross‐talk between oxidative stress, cation homeostasis and ethylene.
Histology of ferret skin: preweaning to adulthood
Authors: Martin A. L , Irizarry‐Rovira A. R , Bevier D. E , Glickman L. G , Glickman N. W , Hullinger R. L 
Published: October 2007

AbstractFerrets are important companion animals that incur a multitude of cutaneous diseases requiring diagnostic dermatohistopathology. This study provides a description of the histology of normal ferret skin, emphasizing changes in the interval from preweaning to adulthood, an essential basis for identification of pathological situations. Skin samples obtained post‐mortem from 29 topographical sites on 41 ferrets, revealed in the haired, general body surface skin an epidermis consisting of strata basale, spinosum, granulosum, and corneum and a dermis consisting of strata papillare and reticulare. Adult skin contained compound hair follicles composed of one primary hair and a collection of secondary hairs with a primary to secondary ratio of 1/5–1/15. All hairs emerged through the same follicle outlet of the skin surface. There was associated with each primary follicle, an arrector pili muscle, a multilobular sebaceous gland, and a coiled tubular sweat gland, but secondary hairs lacked these features. Compound follicles, grouped mainly as triads across the body surface, were already fully formed in the youngest group studied (3 to 6 weeks). The secondary hairs all developed from one specific region of the primary follicles and smaller ones were formed with increasing age. The differences found in specialized body regions are described.Demodexsp. mites were found in follicles and sebaceous glands in nine of 25 individuals in the perianal, vulvar, preputial, facial, and caudal abdominal skin.
Efficacy of selamectin in the treatment of cheyletiellosis in pet rabbits
Authors: Kim Sang‐Hun , Lee Jung‐Youn , Jun Hyung‐Kyou , Song Kun‐Ho , Park Bae‐Kun , Kim Duck‐Hwan 
Published: October 2007

AbstractCheyletiellosis is a very common parasitic skin disorder of pet rabbits typically associated with pruritus and scaling. In this study, a total 23 rabbits with cheyletiellosis were treated with a single topical application of selamectin at a dose of 12 mg kg−1. All rabbits were examined at 3 and 5 weeks after treatment. Five weeks after selamectin application, the scaling and pruritus had resolved in all 23 rabbits, and microscopic examination of epidermal debris collected by acetate tape and flea combing was all negative for mites and eggs. No side‐effects were observed in any of the rabbits. This indicates that selamectin is an effective treatment for cheyletiellosis in rabbits.
Allergen challenge decreases mRNA expression of regulatory cytokines in whole blood of high‐IgE beagles
Authors: Maeda Sadatoshi , Tsuchida Hiromi , Marsella Rosanna 
Published: October 2007

AbstractThe kinetics of cytokine expression was evaluated in whole blood from high‐IgE beagles previously sensitized to house dust mites (HDM) and known to develop clinical signs compatible with atopic dermatitis (AD) upon allergen exposure. Six high‐IgE beagles were environmentally challenged daily for 3 h on three consecutive days with a HDM solution. Clinical signs were evaluated before, during, and after the conclusion of the challenge (days 0, 2, 4 and 17) and expression analyses of Th2 (IL‐4 and IL‐13) and regulatory (IL‐10 and TGF‐β) cytokine mRNA were undertaken on blood samples at each time point using real‐time polymerase chain reaction. Multiple comparison used to detect significant differences in clinical scores and expression levels of cytokine mRNA revealed that the clinical scores on days 2 and 4 were higher than those on days 0 and 17 (P < 0.05) but no temporal differences in the expression levels of IL‐4 and IL‐13 mRNA. Expression of TGF‐β mRNA was, however, significantly lower on day 4 (P < 0.05) and the expression of IL‐10 mRNA on days 4 and 17 was significantly lower than those on days 0 and 2 (P < 0.05). The results indicate that allergen challenge decreases mRNA expression of regulatory cytokines in whole blood without enhanced mRNA expression of Th2 cytokines and suggest aberrant regulatory T‐cell function in the immunopathogenesis of AD in high‐IgE beagles.