bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequency of parafunctional oral habits in patients with cerebral palsy
Authors: ORTEGA A. O. L. , GUIMARÃES A. S. , CIAMPONI A. L. , MARIE S. K. N.
Published: March 2007

Summary  Cerebral palsy (CP) is one of the most frequent conditions encountered in the daily practice of dentists who treat special‐needs patients and it seems that parafunctional oral habits are often present in such individuals. The aim of this study was to investigate the frequency of occurrence of parafunctional habits in individuals with CP. Sixty‐five patients with CP were evaluated through a questionnaire and clinical observation, regarding the following habits: pacifier‐sucking, finger‐sucking, biting objects, tongue interposition, and bruxism. The results showed that nine (13·8%) patients presented with pacifier‐sucking, four (6·1%) showed finger‐sucking, 12 (18·4%) had the habit of biting objects, 27 (41·5%) presented with tongue interposition, and 24 (36·9%) had eccentric bruxism. The significance of the presence of oral parafunctional habits in individuals with CP, revealed in this study, justifies the need to establish protocols for adequate prevention and clinical intervention in order to minimize the deleterious consequences that may result from such habits.
Clinical diagnoses and MRI findings in patients with TMD pain
Authors: LIMCHAICHANA N. , NILSSON H. , EKBERG EC. , NILNER M. , PETERSSON A.
Published: March 2007

Summary  The aim of this study was to compare the findings on magnetic resonance imaging (MRI) in temporomandibular disorders (TMD) pain patients with clinical diagnoses of myofascial pain or arthralgia/osteoarthritis in combination with myofascial pain according to the Research Diagnostic Criteria for TMD. The temporomandibular joints of 60 consecutive patients, 19 with myofascial pain and 41 patients with arthralgia/osteoarthritis in combination with myofascial pain were examined clinically and with MRI. Overall the most common MRI findings were different kinds of disc displacements and structural bone changes, which were found in both pain groups. However, disc displacements were found significantly (P = 0·002) more often in the group arthralgia/osteoarthritis in combination with myofascial pain. One hundred and four joints were found to have no clinical diagnosis of disc displacements, but 64 of these joints had findings of disc displacements on MRI. Joint fluid was found in both pain groups. Patients having a combination of disc displacement and joint fluid were significantly (P = 0·047) more common in the pain group arthralgia/osteoarthritis in combination with myofascial pain. In conclusion, the MRI findings of different kinds of disc displacement and structural bone changes were common in TMD patients. The clinical diagnoses for subdivision into myogenous only or combined arthrogenous and myogenous pain groups were not confirmed by MRI.
Behaviours of three‐dimensional compressive and tensile forces exerted on a tooth during function
Authors: KAWATA T. , YODA N. , KAWAGUCHI T. , KURIYAGAWA T. , SASAKI K.
Published: March 2007

Summary  The 3‐D tensile and compressive forces exerted on a tooth were measured in vivo during function using a force‐measuring device including a piezoelectric transducer. The device was mounted on the maxillary left second molar of a healthy male subject; the subject tooth had been endodontically treated and prepared for metal abutment and a crown. The 3‐D forces were expressed as a vector of the coordinates based on the Frankfort horizontal (x–y) and sagittal (y–z) planes. The device captured the sequential changes in the forces. The directions of the forces changed during not only chewing a caramel or a peanut but also maximum voluntary clenching (MVC). As the magnitudes of the force increased during both MVC and caramel chewing (CaC), the force vector tended to correspond to the direction of the palatal root, medially and posteriorly. The compressive forces during MVC and caramel and peanut chewing were 173·29 ± 15·32, 146·3 ± 14·7 and 57·7 ± 35·7 N, respectively. The force vector during MVC was directed from the crown to the root medially at an angle of 10·27 ± 1·00° from the y–z plane and posteriorly at an angle of 3·18 ± 0·85° from the x–z plane to the perpendicular line of the F‐H plane. There were significant differences in the behaviour of the compressive forces between clenching and chewing. The tensile force was recorded during CaC, not peanut chewing.
A new individual‐based spatial approach for identifying genetic discontinuities in natural populations
Authors: MANEL S. , BERTHOUD F. , BELLEMAIN E. , GAUDEUL M. , LUIKART G. , SWENSON J. E. , WAITS L. P. , TABERLET P. , CONSORTIUM INTRABIODIV
Published: March 2007

The population concept is central in evolutionary and conservation biology, but identifying the boundaries of natural populations is often challenging. Here, we present a new approach for assessing spatial genetic structure without thea prioriassumptions on the locations of populations made by adopting an individual‐centred approach. Our method is based on assignment tests applied in a moving window over an extensively sampled study area. For each individual, a spatially explicit probability surface is constructed, showing the estimated probability of finding its multilocus genotype across the landscape, and identifying putative migrants. Population boundaries are localized by estimating the mean slope of these probability surfaces over all individuals to identify areas with genetic discontinuities. The significance of the genetic discontinuities is assessed by permutation tests. This new approach has the potential to reveal cryptic population structure and to improve our ability to understand gene flow dynamics across landscapes. We illustrate our approach by simulations and by analysing two empirical datasets: microsatellite data ofUrsus arctosin Scandinavia, and amplified fragment length polymorphism (AFLP) data ofRhododendron ferrugineumin the Alps.
Host–parasite kinship in a female‐philopatric bird population: evidence from relatedness trend analysis
Authors: ANDERSSON MALTE , WALDECK PETER
Published: March 2007

Conspecific brood parasitism (CBP), an alternative reproductive tactic where some females lay eggs in the nests of other females of the same species, occurs in many animals with egg care. It is particularly common in waterfowl, for reasons that are debated. Many waterfowl females nest near their birthplace, making it likely that some local females are relatives. We analyse brood parasitism in a Hudson Bay population of common eiders, testing predictions from two alternative hypotheses on the role of relatedness in CBP. Some models predict host–parasite relatedness, others predict that parasites avoid close relatives as hosts. To distinguish between the alternatives, we use a novel approach, where the relatedness of host–parasite pairs is tested against the spatial population trend in pairwise relatedness. We estimate parasitism, nest take‐over and relatedness with protein fingerprinting and bandsharing analysis of egg albumen, nondestructively sampled from each new egg in the nest throughout the laying period. The results refute the hypothesis that parasites avoid laying eggs in the nests of related hosts, and corroborate the alternative of host–parasite relatedness. With an estimated r of 0.12–0.14, females laying eggs in the same nest are on average closer kin than nesting neighbour females. Absence of a population trend in female pairwise relatedness vs. distance implies that host–parasite relatedness is not only an effect of strong natal philopatry: some additional form of kin bias is also involved.
Trade‐off between root porosity and mechanical strength in species with different types of aerenchyma
Authors: STRIKER G. G. , INSAUSTI P. , GRIMOLDI A. A. , VEGA A. S.
Published: March 2007

The objective of this work was to study the existence of a trade‐off between aerenchyma formation and root mechanical strength. To this end, relationships among root anatomical traits and mechanical properties were analysed in plant species with contrasting root structural types: Paspalidium geminatum (graminaceous type), Cyperus eragrostis (cyperaceous type), Rumex crispus (Rumex type) and Plantago lanceolata (Apium type). Variations in anatomical traits and mechanical strength were assessed as a function of root diameter by exposing plants to 0, 7, 15 and 30 d of control and flooded conditions. For each species, the proportion of root cortex was positively associated with the increment of root diameter, contributing to the increase in root porosity under both control and flooded conditions. Moreover, cell lysis produced an additional increase in root porosity in most species under flooded conditions (except R. crispus). Both structural types that presented a uniseriate layer (epidermis) to cope with compression (Rumex and Apium types) were progressively weakened as root porosity increased. This effect was significant even when the increment of root porosity was solely because of increased root diameter (R. crispus), as when both processes (root diameter and cell lysis) added porosity to the roots (P. lanceolata). Conversely, structural types that presented a multiseriate ring of cells in the outer cortex (graminaceous and cyperaceous types) maintained mechanical strength over the whole range of porosity, in spite of lysogenic processes registered in the inner cortex. In conclusion, our study demonstrates a strong trade‐off between aerenchyma formation and mechanical strength in root structural types that lacked a multiseriate ring of tissue for mechanical protection in the outer cortex. The results suggest that this ring of tissue plays a significant role in maintaining the mechanical strength of roots when flooding induces the generation of additional aerenchyma tissue in the root cortex.
Isoprene synthase expression and protein levels are reduced under elevated O3 but not under elevated CO2 (FACE) in field‐grown aspen trees
Authors: CALFAPIETRA CARLO , WIBERLEY AMY E. , FALBEL TANYA G. , LINSKEY AUTUMN R. , MUGNOZZA GIUSEPPE SCARASCIA , KARNOSKY DAVID F. , LORETO FRANCESCO , SHARKEY THOMAS D.
Published: March 2007

Emission of hydrocarbons by trees has a crucial role in the oxidizing potential of the atmosphere. In particular, isoprene oxidation leads to the formation of tropospheric ozone and other secondary pollutants. It is expected that changes in the composition of the atmosphere will influence the emission rate of isoprene, which may in turn feedback on the accumulation of pollutants and greenhouse gases. We investigated the isoprene synthase (ISPS) gene expression and the ISPS protein levels in aspen trees exposed to elevated ozone (O3) and/or elevated carbon dioxide (CO2) in field‐grown trees at the Aspen Free‐Air Carbon Dioxide Enrichment (FACE) experimental site. Elevated O3 reduced ISPS mRNA and the amount of ISPS protein in aspen leaves, whereas elevated CO2 had no significant effect. Aspen clones with different O3 sensitivity showed different levels of inhibition under elevated O3 conditions. The drop in ISPS protein levels induced a drop in the isoprene emission rate under elevated O3. However, the data indicated that other mechanisms also contributed to the observed strong inhibition of isoprene emission under elevated O3.
Characterization and expression analysis of genes encoding α and β carbonic anhydrases in Arabidopsis
Authors: FABRE NICOLAS , REITER ILJA M , BECUWE‐LINKA NOELLE , GENTY BERNARD , RUMEAU DOMINIQUE
Published: March 2007

Carbonic anhydrases (CAs) are Zn‐containing metalloenzymes that catalyse the reversible hydration of CO2. We investigated the αCA and βCA families in Arabidopsis, which contain eight αCA (AtαCA1‐8) and six βCA genes (AtβCA1‐6). Analyses of expressed sequence tags (ESTs) from The Arabidopsis Information Resource (TAIR) database indicate that all the βCA encoding sequences, but only three of the AtαCA, are expressed. Using semi‐quantitative PCR experiments, functional CA genes were more strongly expressed in green tissue, but strong expression was also found in roots for βCA3, βCA6 and αCA2. Two αCA genes were shown to respond to the CO2 environment, while the others were unresponsive. Using the green fluorescent reporter protein gene fused with cDNA sequences coding for βCAs, we provided evidence that βCAs were targeted to specific subcellular compartments: βCA1 and βCA5 were targeted to the chloroplast, βCA2 and βCA3 to the cytosol, βCA4 to the plasma membrane and βCA6 to the mitochondria. The targeting and the pattern of gene expression suggest that CA isoforms play specific roles in subcellular compartments, tissues and organs. The data indicate that other CA isoforms than the well‐characterized βCA1 may contribute to the CO2 transfer in the cell to the catalytic site of ribulose 1·5‐bisphosphate carboxylase/oxygenase (Rubisco).
Peripheral Blood CD161+ T Cells from Asthmatic Patients are Activated During Asthma Attack and Predominantly Produce IFN‐γ
Authors: González‐Hernández Y. , Pedraza‐Sánchez S. , Blandón‐Vijil V. , Del Río‐Navarro B. E. , Vaughan G. , Moreno‐Lafont M. , Escobar‐Gutiérrez A.
Published: March 2007

In humans, T cells expressing the CD161 molecule NKR‐P1A constitute around 20% of the circulating CD3+ cells and are potentially immunoregulatory in several diseases. Their role in asthma is not well known, but they could participate in asthma attacks. To determinate whether activation of CD161+ T cells and their cytokine production correlate with clinical status of asthma, we analysed blood samples from asthma attack patients (AAP) and stable asthma patients (SAP) in comparison with healthy non‐atopic controls (HC). There was a significant higher baseline expression of CD69 on T cells from AAP and the difference was more notorious on CD161+ T cells; upregulation of CD69 was observed on both CD161− and CD161+ T cells driven by Dermatophagoides pteronyssinus crude extract, whereas polyclonal stimulation with phorbol 12‐myristate 13‐acetate plus ionomycin predominantly induced IFN‐γ but no IL‐4, IL‐5 and IL‐13 by CD161+ T cells in all groups; upon polyclonal stimulation, there were more CD161+ T cells producing IFN‐γ and less CD161− T cells producing this cytokine, contrasting with the opposite results observed in SAP and HC groups. Our results indicate that, during asthma attack, CD161+ T cells are activated and are able to produce predominantly IFN‐γ but no Th2 cytokines. We hypothesize that during an asthma attack, IFN‐γ produced by CD161+ T cells could help to reestablish the Th1/Th2 equilibrium. These observations may contribute to the understanding of the immune mechanisms involved in asthma attacks.
Antisense oligonucleotide targeting fibroblast growth factor receptor (FGFR)‐1 stimulates cellular activity of hair follicles in an in vitro organ culture system
Authors: Tsuboi R. , Yamazaki M. , Matsuda Y. , Uchida K. , Ueki R. , Ogawa H.
Published: March 2007

Background  The hair cycle is regulated by various molecules, among which FGF‐5 has been shown to promote the transition from anagen to catagen. The FGFR‐1, a trans‐membrane receptor of FGF‐5 with tyrosine kinase activity, is localized in the follicular papilla of hair follicles.

Objectives  In order to apply the antisense oligonucleotides targeting FGFR‐1 as a treatment for baldness, we examined the effect of the oligonucleotides on hair follicle growth in a serum‐free organ culture system.

Methods  Vibrissal hair follicles from C3H/He mice were cultured in the presence of a reagent at 31 °C in 95% O2−5% CO2 for 72 h. A 20‐mer antisense nucleotide and its randomly arranged counterpart were prepared by predicting the effective target site of FGFR‐1 mRNA. Cellular activity in the hair bulb was estimated by measuring the fluorescence intensity (FI) of the medium after incubation with AlamarBlue™ dye.

Results  The addition of 30 µM of the phosphorothioate form of antisense oligonucleotide (A1561TS) to the media increased the FI by 30%, whereas the control produced no detectable change. This effect was reproducible dose‐dependent with maximal stimulation at 30 µM. Incorporation of the oligonucleotide into the follicular papilla was histologically confirmed by incubation with FITC‐labeled phosphorothioate oligonucleotides, and the intact morphological structure of the hair bulb was maintained intact after a 72‐h incubation.

Conclusions  These results suggest the clinical utility of antisense nucleotide targeting FGFR‐1 as a treatment for baldness.
Pressure ulcers: A pilot study for treatment with collagen polyvinylpyrrolidone
Authors: Zerón Hugo Mendieta , Gómez Fernando Edgar Krötzsch , Muñoz Rolando Efraín Hernández
Published: March 2007

Background   Chronic ulcers owing to pressure cause complications with respect to immobilization and develop through limited blood circulation. There are different treatments for these ulcers; nonetheless, the search for an efficient and economical option continues. One choice could be collagen‐polyvinylpyrrolidone (clg‐pvp). Presence of pressure ulcers in hospitalized patients constitutes a frequent medical problem which is difficult to manage and can be an entry route for infection. Also, restoring the dermic continuity offers a means of improving a patient's quality‐of‐life.

Objective   The aim of the study was to analyze whether cicatrization on pressure ulcers presents more rapidly with local cleaning with soap, application of zinc oxide paste and clg‐pvp compared with local cleaning with soap, application of zinc oxide paste and placebo (saline solution with polyvinylpyrrolidone).

Methodology   From July 2002 to April 2003 the authors conducted a clinical, comparative, prospective, longitudinal, randomized study. Coded flasks containing either clg‐pvp or placebo were designated for patients according to a table of random numbers.

The clg‐pvp or placebo was applied to each patient's ulcers at a rate of 1.5 ml intradermically at the four equi‐spaced points around the ulcer. The nominal diameter of each ulcer was measured at the start of the study and then weekly over a 3‐week period. Statistical analysis was carried out using the SPSS (version 10; SPSS Inc., Chicago, IL) software program.

Results   The group treated with clg‐pvp experienced a reduction in mean ulcer size from 3.4 to 1.41 cm in diameter, whereas in the placebo group the reduction was from 2.9 to 1.58 cm in diameter. Despite the greater diameter reduction in the first group, the lack of a statistically significant difference could have resulted from the short follow‐up period and small sample size.
Gaegurin 4, a peptide antibiotic of frog skin, forms voltage‐dependent channels in planar lipid bilayers
Authors: Kim H. J. , Han S. K. , Park J. B. , Ryu P. D. , Baek H. J. , Lee B. J.
Published: March 2007

Gaegurin 4 (GGN4) is a cationic peptide of 37 amino acids (MW 3748) isolated from the skin of Rana rugosa. It has shown a broad spectrum antimicrobial activity in vitro against Gram‐negative and ‐positive bacteria, fungi and protozoa. To understand its mechanism of antimicrobial action, we examined the effect of GGN4 on the membrane conductance and the electrical properties of GGN4‐induced pores in planar lipid bilayers under voltage clamp. Natural and synthetic GGN4 (0.01–1 μg/mL) increased the membrane conductance in a concentration‐dependent manner, but GGN4 (1–23), an N‐terminal fragment of the peptide with little antimicrobial activity, faiied to increase the conductance. At symmetrical 100 mM KCl, unitary conductances of about 120 pS were frequently observed. Their current‐voltage relations were linear and open state probabilities were close to 1, but longer closing events were seen more frequently at negative voltages. In addition, GGN4‐induced pores were selective for cation over anion, the permeability ratio of K+ to Cl‐ being 6: 1 in neutral and 7: 1 in acidic lipid bilayers. In conclusion, our results indicate that GGN4 forms voltage‐dependent and cation‐selective pores in planar lipid bilayers. The ionophoric property of GGN4 is likely to contribute to its antimicrobial activity.
Conformational study of Ac‐Xaa‐Pro‐NHMe dipeptides: proline puckering and trans/cis imide bond
Authors: Kang Y. K. , Jhon J. S. , Han S. J.
Published: March 2007

The conformational study on 20 Ac‐Xaa‐Pro‐NHMe dipeptides has been carried out using an empirical potential function ECEPP/3 in order to investigate the factors responsible for the preference of proline puckering of the peptides with the trans or cis imide bond preceding the proline. The general conformational preference for down‐ and up‐puckered dipeptides is calculated as trans‐down > trans‐up > cis‐down > cis‐up, which is reasonably in accord with that estimated by analyzing X‐ray structures of proteins and the result for the single proline residue. The overestimated occurrence of trans‐down conformations of proline seems to be caused by excluding long‐range interactions that short dipeptides cannot have. The average computed occurrence of dipeptides with cis imide bonds is about 3%, somewhat lower than the value calculated for Ac‐Pro‐NHMe, which is close to experimental estimates obtained from X‐ray structures of proteins. In particular, the interaction of the aromatic side chain of Xaa residue with the proline ring appears not to be strong enough to stabilize the stacked conformations of small dipeptides with cis imide bonds. The propensity to adopt trans or cis imide bond and to form secondary structures of Xaa‐Pro sequences is discussed and compared with results obtained from X‐ray structures of proteins.
Structure‐activity relationship study: short antimicrobial peptides
Authors: Oh J.E. , Hong S.Y. , Lee K.‐H.
Published: March 2007

Many short antimicrobial peptides (< 18mer) have been identified for the development of therapeutic agents. However, Structure‐activity relationship (SAR) studies about short antimicrobial peptides have not been extensively performed. To investigate the relationship between activity and structural parameters such as an α‐helical structure, a net positive charge and a hydrophobicity, we synthesized and characterized diastereomers, scramble peptides and substituted peptides of the short antimicrobial peptide identified by combinatorial libraries. Circular dichroism (CD) spectra and in vitro activity indicated that an α‐helical structure correlated with the antimicrobial activity and a β‐sheet structure also satisfied a structural requirement for antimicrobial activity. Most peptides consisting of l‐amino acids lost antifungal activity in the presence of heat‐inactivated serum, while active diastereomers and a scramble peptide with the β‐sheet structure retained antifungal activity in the same condition.
Conformational changes of polyomavirus major capsid protein VP1 in sodium dodecyl sulfate solution
Authors: Yang Y.‐W. , Teng C.‐C.
Published: March 2007

Conformations of polyomavirus (Py) major capsid protein VP1 were analyzed by circular dichroism (CD) and fluorescence spectroscopy in the presence of sodium dodecyl sulfate (SDS). Binding of PyVP1 to SDS induced marked conformational changes of PyVP1, which were reflected on the CD and fluorescence spectra. Abrupt changes in both optical properties occurred within the narrow ranges of SDS concentrations with the transition midpoints closely related to SDS micelle formation. Analysis of circular dichroism spectra showed that the contents of α‐helices, β‐sheets, β‐turns and random coils in PyVP1 varied upon addition of SDS, demonstrating the exquisite sensitivity of the conformations of the protein to the environment. The interactions of PyVP1 with SDS were shown to be dependent on the ionic strength of the protein solution, suggesting that both hydrophobic and electrostatic forces contribute to the PyVP1‐SDS complex formation. The SDS‐induced conformational changes of PyVP1 appeared to be a two‐stage process.
Structure‐antibacterial, antitumor and hemolytic activity relationships of cecropin A‐magainin 2 and cecropin A‐melittin hybrid peptides
Authors: Shin S. Y. , Kang J. H. , Hahm K.‐S.
Published: March 2007

In order to elucidate the structure‐antibiotic activity relationship of cecropin A‐magainin 2 and cecropin A‐melittin hybrid peptides, several truncated peptides and the analogues with amino acid substitutions were synthesized and their antibacterial, antitumor and hemolytic activities of were examined. Cecropin A‐magainin 2 hybrid analog, L16‐CA(1–8)‐MA(1–12) (termed as L‐CA‐MA in this study: KWKLFKKIGIGKFLHLAKKF‐NH2), is known to have potent antibacterial and antitumor activity with less hemolytic activity. We found that the C‐terminal region of L‐CA‐MA is more involved in the α‐helical structure on cell membrane‐like environment than N‐terminal one by circular dichroism analysis. Deletion of the Gly‐lle‐Gly sequence, the central hinge region of L‐CA‐MA, produced a considerable reduction in antitumor and hemolytic activity rather than an antibacterial one. The insertion of Pro, Gly‐lle or Gly‐Pro in this hinge region of L‐CA‐MA caused retention of both antibacterial and antitumor activity while causing a significant decrease in hemolytic activity. However, the substitution with Gly‐Pro‐Gly instead of the Gly‐lle‐Gly in CA(1–8)‐MA(1–12), CA(1–8)‐ME(1–12), CA(1–13)‐MA(1–13) and CA(1–13)‐ME(1–13) hybrids resulted in a drastic decrease in antibacterial, antitumor and hemolytic activity. The increase of hydrophobicity at position 16 in CA(1–8)‐MA(1–12) by substituting Trp or Phe induced a significant increase in hemolytic activity without a considerable change in either antibacterial or antitumor activity. Therefore, these results suggested that the appropriate flexibility in the hinge region of CA‐MA and CA‐ME hybrid peptides and the appropriate hydrophobicity at position 16 in the hydrophobic region of CA (1–8)‐MA(1–12) are important in potent antibacterial and antitumor activity with no hemolytic effect.
Toward a mechanistic understanding of larval dispersal: insights from genomic fingerprinting of the deep‐sea hydrothermal vent tubeworm Riftia pachyptila
Authors: Shank Timothy M. , Halanych Kenneth M.
Published: March 2007

Larval dispersal is critical for the maintenance of species populations in patchy and ephemeral hydrothermal vent habitats. On fast‐spreading ridges, such as the East Pacific Rise, rates of habitat turnover are comparable to estimated lifespans of many of the inhabiting species. Traditionally, dispersal questions have been addressed with two very different approaches, larval studies and population genetics. Population genetic studies of vent‐endemic species have been informative for determining whether patterns of dispersal are suggestive of stepping stone or island models and estimating rates of gene flow (effective migrants per generation) over broad geographic ranges. However, these studies leave fundamental questions unanswered about the specific mechanisms by which larvae disperse and species maintain their populations and biogeographic ranges. With the goal of examining genetic structure and elucidating alternative larval dispersal mechanisms, we employed a genomic DNA fingerprinting technique, amplified fragment length polymorphisms (AFLPs). To assess the potential utility of AFLPs, and genetic structure of the hydrothermal vent tubeworm Riftia pachyptila, genomic ‘fingerprints’ were recovered from 29 individuals from five vent fields spanning a distance of up to c. 5000 km along the East Pacific Rise. In contrast to previous population genetic studies that found little to no genetic structure using allozymes and mitochondrial DNA, genetic analyses of 630 polymorphic AFLP loci identified distinct subclades within R. pachyptila populations. Significant levels of differentiation were observed among populations from all vent regions as well as within each region. Discrete assemblages of tubeworms separated by as little as c. 400 m within a given vent region were genetically distinguishable and cohorts (based on size‐frequency distribution) within an aggregation were found to be most closely related. These results suggest that mechanisms of larval dispersal act to retain cohort fidelity in R. pachyptila.
Spatial and temporal evolution of arc volcanism in the northeast Honshu and Izu‐Bonin Arcs: Evidence of small‐scale convection under the island arc?
Authors: Honda Satoru , Yoshida Takeyoshi , Aoike Kan
Published: March 2007

Abstract  Arc volcanism of the past 10 my in the northeast Honshu and Izu‐Bonin Arcs shows several notable features. In the northeast Honshu Arc, the spatial distribution of volcanism exhibits several clusters elongated nearly perpendicular to the arc and the possible migration of volcanism from the back‐arc side to the volcanic front side, at least, during the past 5 my. The pattern of clusters seems to have flip‐flopped around 5 Ma. In the Izu‐Bonin Arc, there are a series of across‐arc seamount chains, in which volcanic activity occurred from ca 17 Ma to ca 3 Ma, similar to the clusters of the northeast Honshu Arc, although the recent active rifting occurs almost parallel to the arc. On the basis of studies of numerical modeling, these features might be explained, at least qualitatively, by the small‐scale convection under the island arc. Several inferences can be made from our modeling results for the tectonics of the Izu‐Bonin Arc. The angle of dip of subducting plate in the Izu‐Bonin Arc might have increased. This can explain the disappearance of volcanism along the seamount chains and the recent along‐arc volcanism with narrow rifting. The trend of seamount chains, which is oblique to the arc, might not be their intrinsic feature but rather a result of the lateral movement of the back‐arc region after their formation. These inferences can be tested by the future detailed morphological and chronological studies of the Izu‐Bonin Arc.
New weed management strategy using subterranean clover reseeding under different tillage systems: Numerical experiments with the subterranean clover‐tillage dynamics model
Authors: KOMATSUZAKI MASAKAZU
Published: March 2007

Subterranean clover (Trifolium subterraneum L.) appears to be a suitable winter legume cover crop for Japan because the subterranean clover stands maintain themselves by reseeding in autumn and the large seeds facilitate establishment and enable early fall production. However, there is little information on the relationship between reseeding and tillage systems for subterranean clover under Japanese climatic conditions. A weed‐tillage population dynamics model was developed to investigate the effects of the tillage method and timing on the reseeding of subterranean clover. The field experiments were conducted in a silage corn and subterranean clover rotation system. The life cycle of subterranean clover was modeled to describe the seed production competing with weed growth, seasonal changes in the buried seeds’ viability, and the movement of seeds by tillage treatments. In the numerical simulation, the effect of the tillage method on the seedling population of reseeded subterranean clover was investigated and the simulation results showed good agreement with the experimental results. Rotary tilling immediately after subterranean clover seed maturation successfully produced a good subterranean clover stand the following spring. However, rotary tillage conducted 2 months after seed maturation killed the emerging subterranean clover seedlings and the field was dominated by winter weeds. These simulation results suggest that a suitable tillage system can maintain successful subterranean clover re‐establishment from year to year.
Plant classification for weed detection using hyperspectral imaging with wavelet analysis
Authors: OKAMOTO HIROSHI , MURATA TETSURO , KATAOKA TAKASHI , HATA SHUN‐ICHI
Published: March 2007

The goal of this study is to develop a new weed detection method that can be applied for automatic mechanical weed control. For successful weed detection, plants must be classified into crops and weeds according to their species. In this study, we employed a portable hyperspectral imaging system. The hyperspectral camera can capture landscape images that include crops, weeds, and the soil surface, and can provide more extensive information than conventional red, green, and blue (RGB) images. Although RGB images consist of red, green, and blue wavebands, the obtained hyperspectral images consist of 240 wavebands of spectral information. Hyperspectral imaging is expected to provide powerful technology for agricultural sensing. In the initial step of this study, the image pixels of the plants (crop or weeds) were segmented from the background soil surface using Euclidean distance as the discriminant function. In the next step, the image pixels of the crop (sugarbeet) and weeds (four species) were classified using the difference in the spectral characteristics of the plant species. In this process, classification variables were generated using wavelet transformation for data compression, noise reduction, and feature extraction, and then stepwise linear discriminant analysis was applied. The validation results indicate that the developed classification method has potential for practical use.
Targeting hyperglycaemia with either metformin or repaglinide in non‐obese patients with type 2 diabetes: results from a randomized crossover trial
Authors: Lund S. S. , Tarnow L. , Stehouwer C. D. A. , Schalkwijk C. G. , Frandsen M. , Smidt U. M. , Pedersen O. , Parving H.‐H. , Vaag A.
Published: March 2007

Aim:  Metformin is the ‘drug‐of‐first‐choice’ in obese patients with type 2 diabetes mellitus (T2DM) due to its antihyperglycaemic and cardiovascular protective potentials. In non‐obese patients with T2DM, insulin secretagogues are empirically used as first choice. In this investigator‐initiated trial, we evaluated the effect of metformin vs. an insulin secretagogue, repaglinide on glycaemic regulation and markers of inflammation and insulin sensitivity in non‐obese patients with T2DM.

Methods:  A single‐centre, double‐masked, double‐dummy, crossover study during 2 × 4 months involved 96 non‐obese (body mass index ≤ 27 kg/m2) insulin‐naïve patients with T2DM. At enrolment, previous oral hypoglycaemic agents (OHA) were stopped and patients entered a 1‐month run‐in on diet‐only treatment. Hereafter, patients were randomized to either repaglinide 2 mg thrice daily followed by metformin 1 g twice daily or vice versa each during 4 months with 1‐month washout between interventions.

Results:  End‐of‐treatment levels of haemoglobin A1c (HbA1c), fasting plasma glucose, mean of seven‐point home‐monitored plasma glucose and fasting levels of high‐sensitivity C‐reactive protein and adiponectin were not significantly different between treatments. However, body weight, waist circumference, fasting serum levels of insulin and C‐peptide were lower and less number of patients experienced hypoglycaemia during treatment with metformin vs. repaglinide. Both drugs were well tolerated.

Conclusions:  In non‐obese patients with T2DM, overall glycaemic regulation was equivalent with less hypoglycaemia during metformin vs. repaglinide treatment for 2 × 4 months. Metformin was more effective targeting non‐glycaemic cardiovascular risk markers related to total and abdominal body fat stores as well as fasting insulinaemia. These findings may suggest the use of metformin as the preferred OHA also in non‐obese patients with T2DM.
Conflict, camps and coercion: the ongoing livelihoods crisis in Darfur
Authors: Buchanan‐Smith Margie , Jaspars Susanne
Published: March 2007

This paper presents the findings of a study commissioned by World Food Programme (WFP) in early 2006 to enhance understanding of how the conflict in Darfur has affected livelihoods and markets, and of the effects of food aid. The livelihoods of many in Darfur were devastated early on in the conflict, principally through the widespread looting or destruction of assets and highly restricted population movements, which struck at the heart of pre‐conflict livelihoods. Livelihood strategies for most people are now restricted, poorly remunerated and often associated with high risk of attack. Patterns of coercion and exploitation have also become entrenched; and markets and trade, the lifeblood of Da fur's economy pre‐conflict, severely disrupted. Against this backdrop the impact of food aid on livelihoods in Darfur has been overwhelmingly positive. The paper proposes a number of preconditions for investment in recovery in Darfur, and recommends ways in which livelihoods can be supported in the current context of ongoing conflict.
From food aid to livelihoods support: rethinking the role of WFP in eastern Sudan
Authors: Pantuliano Sara
Published: March 2007

Despite more than 20 years of distribution of free emergency food in eastern Sudan (38 years in the case of refugees) Global Acute Malnutrition rates are currently the highest in the country. There has been no real improvement in the chronic livelihoods vulnerability that affects people in the region—particularly pastoralists. Food security must be seen from an informed livelihoods perspective. While food aid may still be required as part of transition, WFP must rethink its assistance strategy and advocate for complementarity in the efforts by development actors working across a range of sectors. Alternative models and interventions focused on the rehabilitation of markets and the development of’ cargo nets’ for the destitute, including cash transfers, must be developed and tested. Land tenure issues should be given particular attention. Food aid will probably remain an important element in the overall response, but its significance relative to other less developed forms of interventions should be reassessed.
Personal Political Salience: The Role of Personality in Collective Identity and Action
Authors: Duncan Lauren E. , Stewart Abigail J.
Published: March 2007

Personal political salience(PPS) is proposed as a personality characteristic that assesses individuals' linkage of political events with their personal identities. Its role in facilitating the development of politicized collective identity and action is examined. In four samples of midlife and activist women, we show that PPS was consistently related both to politicized gender identity and political participation. Further analyses show similar results for PPS, politicizedracialidentity, and political participation. Politicized gender identity mediated the relationship between PPS and women's rights activism, and politicized racial identity mediated the relationship between PPS and civil rights activism. PPS is demonstrated to independently predict political action and also to provide a personality link between group memberships, politicized collective identity, and political participation.
Social Influence on Political Judgments: The Case of Presidential Debates
Authors: Fein Steven , Goethals George R. , Kugler Matthew B.
Published: March 2007

Four experiments investigated the extent to which judgments of candidate performance in presidential debates could be influenced by the mere knowledge of others’ reactions. In Experiments 1 and 2 participants watched an intact version of a debate or an edited version in which either “soundbite” one‐liners or the audience reaction to those soundbites were removed. In Experiment 3 participants saw what was supposedly the reaction of their fellow participants on screen during the debate. Participants in Experiment 4 were exposed to the reactions of live confederates as they watched the last debate of an active presidential campaign. In all studies, audience reactions produced large shifts in participants’ judgments of performance. The results illustrate the power of social context to strongly influence individuals’ judgments of even large amounts of relevant, important information, and they support the categorization of presidential debates as ambiguous stimuli, fertile ground for informational social influence.
Integrative Complexity of 41 U.S. Presidents
Authors: Thoemmes Felix J. , Conway Lucian Gideon
Published: March 2007

Although U.S. presidents are one of the most studied groups of political figures and integrative complexity is one of the most widely used constructs in political psychology, no study to date has fully examined the integrative complexity of all U.S. presidents. The present study helps fill in that gap by scoring 41 U.S. presidents' first four State of the Union speeches for integrative complexity and then comparing these scores with a large range of available situational and personality variables. Results suggest a tendency for presidents' integrative complexity to be higher at the beginning of their first term and drop at the end. This pattern was pronounced for presidents who eventually won reelection to a second term and was markedly different for presidents who tried to gain reelection but lost. Additional analyses suggested that presidents' overall integrative complexity scores were in part accounted for by chronic differences between presidents' complexity levels. Further analyses revealed that this overall integrative complexity score was positively correlated to a set of interpersonal traits (friendliness, affiliation motive, extraversion, and wittiness) and negatively correlated with inflexibility. Discussion centers upon the causes and consequences of presidential complexity.
After Number Ten: What Do Former Prime Ministers Do?
Authors: THEAKSTON KEVIN
Published: March 2007

The article reviews the experience of former British prime ministers in the twentieth century. There is no fixed or predetermined role for former prime ministers. What they do after they leave office depends on personal choices and on circumstances. Some have largely disappeared from the political stage. Others have become active international ‘elder statesmen’. A couple‐Heath and Thatcher‐were embittered ‘models to avoid’. A quarter of the former prime ministers since 1900 have served in other government posts in their successors’ Cabinets, while a handful have turned down such appointments. Most have gone to the Lords, which offers a political platform, but sometimes they do not think much of the quality of the second chamber. The retirements of some former prime ministers have been clouded by money worries, but they nowadays get substantial pensions and can make money from business directorships, international lectures and writing memoirs. The article concludes with speculation about what Tony Blair's post‐premiership might hold.
Specifying the transformations within and between geographic data models
Authors: GAHEGAN MARK
Published: March 2007

Geographic information is acquired according to several different underlying models of geographic space. Any meaning inherent within a dataset is intrinsically connected to the model by which it was captured. A design is presented for an integrated geographic information system offering a number of distinct views onto geographic space, of varying degrees of abstraction, to support the needs of an expanded user base. An architecture for such a system is developed by an extension of the traditional three layer architecture used in database design. The movement of data from one level of abstraction to another is formalized by a series of dataset and model transformations operating between four different geographic data models. From this formalism, a functional taxonomy of GIS operations is developed.
Consistency among parts and aggregates: A computational model
Authors: TRYFONA NECTARIA , EGENHOFER MAX J
Published: March 2007

Heterogeneous geographic databases contain multiple views of the same geographic objects at different levels of spatial resolution. When users perceive geographic objects as one spatial unit, although they are physically separated into multiple parts, appropriate methods are needed to assess the consistency among the aggregate and the parts. The critical aspect is that the overall spatial relationships with respect to other geographic objects must be preserved throughout the aggregation process. We developed a systematic model for the constraints that must hold with respect to other spatial objects when two parts of an object are aggregated. We found three sets of configurations that require increasingly more information in order to make a precise statement about their consistency: (1) configurations that are satisfied by the topological relations between the two parts and the object of interest; (2) configurations that need further information about the topological relation between the object of concern and the connector in order to be resolved unambiguously; and (3) configurations that require additional information about the topological relation between the aggregate's boundary and the boundary or interior of the object of interest to be uniquely described. The formalism extends immediately to relations between two regions with disconnected parts as well as to relations between a region and an arbitrary number of separations.
Using GIS to enhance agricultural planning: The example of inter‐seasonal rainfall variability in Zimbabwe
Authors: CORBETT JOHN D , CARTER SIMON E
Published: March 2007

Inter‐seasonal rainfall variability is evaluated as a potential source of much needed information for agroecological or agroclimatological classifications. For some food crop production areas, inter‐seasonal rainfall variability appears to dominate decisions in the crop‐production strategy. We constructed 31 years worth of seasonal rainfall surfaces for Zimbabwe using techniques as described by Hutchinson (1995) and his software ANUSPLIN. We evaluated these surfaces in an effort to describe the main rainfall period (October to March) for Zimbabwe in terms of rainfall variability. Our results were then put into the context of an agroecological study which produced a Natural Regions map for Zimbabwe. GIS technology enables the synthesis and integration of many more data than was possible in a pre‐computer era and robust rainfall variability surfaces contribute towards improved agroecological and agroclimatological classifications for planning (natural resource management and agricultural) purposes. GIS technology also enables a shift in the design of such agroecological or agroclimatological studies: dynamic characterization can readily produce objective specific classifications, classifications which use the wealth of data readily accessible in a GIS to produce maps and databases reflecting specific boundary conditions.
The visualization of socio‐economic GIS data using virtual reality tools
Authors: MARTIN DAVID , HIGGS GARY
Published: March 2007

This paper addresses two issues: the use of ‘realistic’ environments for the visualization of socio‐economic data, and the use of virtual reality tools for the exploration of data from existing GIS databases. ‘Realistic’ is here used in a narrow sense to imply the reconstruction of real‐world scenes in which major components of the physical environment are reconstructed to facilitate geographical visualization. A review of visualization techniques for geographically‐referenced 3‐D data is presented, and the translation of an existing urban GIS database into virtual reality modelling language (VRML) demonstrated for a study area in Cardiff, UK. This work shows that the export of conventional 2‐D GIS data into virtual reality toolkits can be relatively straightforward, and offers exciting new avenues for visualization and exploration. We argue that some of the parameters of the true scene such as colour, building shape, and texture may be directly modified in order to represent otherwise unobservable socio‐economic characteristics, in the spirit of exploratory data analysis. These issues are of particular importance in the context of current advances towards the dynamic linkage of GIS and virtual reality modelling.