bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fracture resistance of thin‐walled roots restored with different post systems
Authors: Kıvanç B. H. , Alaçam T. , Ulusoy Ö. İ. A. , Genç Ö. , Görgül G. 
Published: September 2009

AbstractAim  To compare the fracture resistance of thin‐walled roots after restoration with different types of post systems.Methodology  One hundred and sixty‐five decoronated maxillary central incisors were root filled and randomly assigned to three groups with respect to the remaining dentine thickness of root (1.0 mm, 1.5 mm, 2.0 mm). Each group was randomly divided into five equal subgroups. The subgroups were restored with one of the following post systems: polyethylene woven fibre (R), composite resin cured by light‐transmitting post + glass fibre post (L), electrical glass fibre post (E), composite corono‐radicular restoration (C) and cast metal post (M). Standard cores were constructed using composite resin in the first four groups. The samples were subjected to a gradually increasing force (1 mm min−1). The force required to fracture was recorded. The data was analysed with anova and Tukey test (P = 0.05).Results  The cast metal post group had the highest fracture strength (P < 0.001). There was no significant difference in fracture resistance between the other four groups. Fracture resistance was affected largely by the remaining dentine thickness in fibre post groups; however, the difference was not significant. On the contrary in the cast metal post group load failure was inversely influenced by axio‐proximal dimension of dentine walls.Conclusion  The cast post group had a higher fracture strength than resin groups. The force required to fracture the roots was similar for all fibre post systems and for all dentine thicknesses.
Effect of acid‐etching procedure on selected physical properties of mineral trioxide aggregate
Authors: Kayahan M. B. , Nekoofar M. H. , Kazandağ M. , Canpolat C. , Malkondu O. , Kaptan F. , Dummer P. M. H. 
Published: September 2009

AbstractAim  To evaluate the effect of acid‐etch procedures on the compressive strength and surface microhardness of tooth‐coloured mineral trioxide aggregate (MTA).Methodology  White ProRoot MTA (Dentsply Tulsa Dental) was mixed and packed into cylindrical tubes of 4 mm in diameter and 6 mm in height. Three groups, each of 15 specimens were subjected to an acid‐etch procedure either 4, 24 or 96 h after mixing. The compressive strength was measured and compared with unetched control groups. Differences between groups were analysed using the Kruskall–Wallis test. A further batch of cylindrical specimens of 6 mm in diameter and 12 mm in height were prepared for testing surface microhardness. Three groups of 15 specimens were subjected to the acid‐etch procedure at either 4, 24 or 96 h following mixing. Data were subjected to one‐way anova. Changes in the surface microstructure before and after the acid‐etch procedures were analysed using a scanning electron microscope (SEM).Results  There was a general trend for the compressive strength and surface microhardness of specimens to increase with time. In terms of compressive strength, the increase was significant between 4 h and the other time periods for both experimental and control groups (P < 0.0001); however, there was no significant difference between 24 and 96 h. The increase in surface microhardness was significant between 4, 24 and 96 h (P < 0.0001). In addition, there was a significant difference between experimental and control groups at all time periods (P < 0.0001). SEM examination revealed morphological differences between the intact and the etched MTA surfaces.Conclusions  Acid‐etch procedures affected the compressive strength and surface microhardness of ProRoot MTA. This indicates that it may be better to postpone restorative procedures for at least 96 h after mixing MTA. Etching created surface changes that might have the potential to enhance bonding of resinous materials.
Considering ecological dynamics in resource selection functions
Authors: McLoughlin Philip D. , Morris Douglas W. , Fortin Daniel , Vander Wal Eric , Contasti Adrienne L. 
Published: September 2009

Summary 1. Describing distribution and abundance is requisite to exploring interactions between organisms and their environment. Recently, the resource selection function (RSF) has emerged to replace many of the statistical procedures used to quantify resource selection by animals. 2. A RSF is defined by characteristics measured on resource units such that its value for a unit is proportional to the probability of that unit being used by an organism. It is solved using a variety of techniques, particularly the binomial generalized linear model. 3. Observing dynamics in a RSF – obtaining substantially different functions at different times or places for the same species – alerts us to the varying ecological processes that underlie resource selection. 4. We believe that there is a need for us to reacquaint ourselves with ecological theory when interpreting RSF models. We outline a suite of factors likely to govern ecologically based variation in a RSF. In particular, we draw attention to competition and density‐dependent habitat selection, the role of predation, longitudinal changes in resource availability and functional responses in resource use. 5. How best to incorporate governing factors in a RSF is currently in a state of development; however, we see promise in the inclusion of random as well as fixed effects in resource selection models, and matched case–control logistic regression. 6. Investigating the basis of ecological dynamics in a RSF will allow us to develop more robust models when applied to forecasting the spatial distribution of animals. It may also further our understanding of the relative importance of ecological interactions on the distribution and abundance of species.
Model based precision structural measurements on barely resolved objects
Authors: BADDELEY D. , WEILAND Y. , BATRAM C. , BIRK U. , CREMER C. 
Published: September 2009

SummaryA model based method for the accurate quantification of the 3D structure of fluorescently labelled cellular objects similar in size to the optical resolution limit is presented. This method is applied to both simulated confocal images of chromatin structures and to real confocal data obtained on a Fluorescence in situ Hybridization (FISH) labelled gene domain. The model assumes that the object is composed of a small number of discrete points which are convolved with the microscope point spread function to give the image. Fitting this model to image data results in a method to assess object structure which is accurate, shows a low bias, and does not require user intervention or the potentially subjective setting of a threshold.
Genomic reaction norms: using integrative biology to understand molecular mechanisms of phenotypic plasticity
Authors: AUBIN‐HORTH NADIA , RENN SUSAN C. P. 
Published: September 2009

AbstractPhenotypic plasticity is the development of different phenotypes from a single genotype, depending on the environment. Such plasticity is a pervasive feature of life, is observed for various traits and is often argued to be the result of natural selection. A thorough study of phenotypic plasticity should thus include an ecological and an evolutionary perspective. Recent advances in large‐scale gene expression technology make it possible to also study plasticity from a molecular perspective, and the addition of these data will help answer long‐standing questions about this widespread phenomenon. In this review, we present examples of integrative studies that illustrate the molecular and cellular mechanisms underlying plastic traits, and show how new techniques will grow in importance in the study of these plastic molecular processes. These techniques include: (i) heterologous hybridization to DNA microarrays; (ii) next generation sequencing technologies applied to transcriptomics; (iii) techniques for studying the function of noncoding small RNAs; and (iv) proteomic tools. We also present recent studies on genetic model systems that uncover how environmental cues triggering different plastic responses are sensed and integrated by the organism. Finally, we describe recent work on changes in gene expression in response to an environmental cue that persist after the cue is removed. Such long‐term responses are made possible by epigenetic molecular mechanisms, including DNA methylation. The results of these current studies help us outline future avenues for the study of plasticity.
How do reproductive skew and founder group size affect genetic diversity in reintroduced populations?
Authors: MILLER K. A. , NELSON N. J. , SMITH H. G. , MOORE J. A. 
Published: September 2009

AbstractReduced genetic diversity can result in short‐term decreases in fitness and reduced adaptive potential, which may lead to an increased extinction risk. Therefore, maintaining genetic variation is important for the short‐ and long‐term success of reintroduced populations. Here, we evaluate how founder group size and variance in male reproductive success influence the long‐term maintenance of genetic diversity after reintroduction. We used microsatellite data to quantify the loss of heterozygosity and allelic diversity in the founder groups from three reintroductions of tuatara (Sphenodon), the sole living representatives of the reptilian order Rhynchocephalia. We then estimated the maintenance of genetic diversity over 400 years (∼10 generations) using population viability analyses. Reproduction of tuatara is highly skewed, with as few as 30% of males mating across years. Predicted losses of heterozygosity over 10 generations were low (1–14%), and populations founded with more animals retained a greater proportion of the heterozygosity and allelic diversity of their source populations and founder groups. Greater male reproductive skew led to greater predicted losses of genetic diversity over 10 generations, but only accelerated the loss of genetic diversity at small population size (<250 animals). A reduction in reproductive skew at low density may facilitate the maintenance of genetic diversity in small reintroduced populations. If reproductive skew is high and density‐independent, larger founder groups could be released to achieve genetic goals for management.
HiddenWolbachiadiversity in field populations of the European cherry fruit fly,Rhagoletis cerasi(Diptera, Tephritidae)
Authors: ARTHOFER WOLFGANG , RIEGLER MARKUS , SCHNEIDER DANIELA , KRAMMER MARTIN , MILLER WOLFGANG J. , STAUFFER CHRISTIAN 
Published: September 2009

AbstractThe European cherry fruit flyRhagoletis cerasihas been a field model for cytoplasmic incompatibility since the mid 1970s. TwoWolbachiastrains were detected in this tephritid species andwCer2 was described as the CI inducing agent dividing European populations into two unidirectional incompatible groups, i.e. southern females produce viable offspring with northern males, whereas the reciprocal cross results in incompatibility. We detected three newWolbachiastrains by sequencing a multitude of plasmids derived fromWolbachiasurface protein gene (wsp) polymerase chain reaction (PCR) products. Strain‐specific primers were developed allowing individual diagnosis without need for cloning. Hybridization of specific PCR products with awspoligonucleotide enhanced the detection limit significantly and revealed the presence of low‐titre infections in some strains, in different ontogenetic stages and in adults of different age. We then performed a survey of strain prevalence and infection frequency in eight European regions.wCer1 was fixed in all populations, whereaswCer2 was detected only in the South.wCer3 frequency was the lowest without a clear distribution pattern. The abundance ofwCer4 was homogenous across Europe. LikewCer2,wCer5 showed significant differences in spatial distribution. Our new findings of previously undetected and recombinantWolbachiastrains inR. cerasireveal a major caveat to the research community not to overlook hiddenWolbachiadiversity in field populations. Low‐titres and geographical variability inWolbachiadiversity are expected to influence the outcome ofWolbachiapopulation dynamics andWolbachia‐based insect population control and may create invasion barriers for expanding and artificially introducedWolbachiastrains.
Molecular road ecology: exploring the potential of genetics for investigating transportation impacts on wildlife
Authors: BALKENHOL NIKO , WAITS LISETTE P. 
Published: September 2009

AbstractTransportation infrastructures such as roads, railroads and canals can have major environmental impacts. Ecological road effects include the destruction and fragmentation of habitat, the interruption of ecological processes and increased erosion and pollution. Growing concern about these ecological road effects has led to the emergence of a new scientific discipline called road ecology. The goal of road ecology is to provide planners with scientific advice on how to avoid, minimize or mitigate negative environmental impacts of transportation. In this review, we explore the potential of molecular genetics to contribute to road ecology. First, we summarize general findings from road ecology and review studies that investigate road effects using genetic data. These studies generally focus only on barrier effects of roads on local genetic diversity and structure and only use a fraction of available molecular approaches. Thus, we propose additional molecular applications that can be used to evaluate road effects across multiple scales and dimensions of the biodiversity hierarchy. Finally, we make recommendations for future research questions and study designs that would advance molecular road ecology. Our review demonstrates that molecular approaches can substantially contribute to road ecology research and that interdisciplinary, long‐term collaborations will be particularly important for realizing the full potential of molecular road ecology.
To see in different seas: spatial variation in the rhodopsin gene of the sand goby (Pomatoschistus minutus)
Authors: LARMUSEAU MAARTEN H. D. , RAEYMAEKERS JOOST A. M. , RUDDICK KEVIN G. , VAN HOUDT JEROEN K. J. , VOLCKAERT FILIP A. M. 
Published: September 2009

AbstractAquatic organisms living in a range of photic environments require specific mechanisms to tune their visual pigments. Maximum absorbance (λmax) of retinal rods in populations of the marine demersal sand goby, (Pomatoschistus minutus; Gobiidae, Teleostei) correlates with the local optic environment. It has been shown that this is not regulated through a physiological response by exchanging the rhodopsin chromophore. To test for evolutionary adaptation, the sequence of the rhodopsin (RH1) gene was analysed in 165 Pomatoschistus minutus individuals from seven populations across its distribution range. Analysis showed a high level of intraspecific polymorphism at the RH1 gene, including nonsynonymous mutations on amino acids, known as spectral tuning sites. Population differentiation at these sites was in agreement with the observed differentiation in λmax values. Analyses of dN/dS substitution rate ratios and likelihood ratio tests under site‐specific models detected a significant signal of positive Darwinian selection on the RH1 gene. A strong discrepancy in differentiation was noticed between RH1 gene variation and the presumably neutral microsatellites and mitochondrial data. Samples did not cluster according to geographical or historical proximity with regards to RH1, but according to the general photic conditions of the habitat environment of the sand goby. This study highlights the usefulness of sensory genes, like rhodopsin, for studying the characteristics of local adaptation in marine nonmodel organisms.
Do arms races punctuate evolutionary stasis? Unified insights from phylogeny, phylogeography and microevolutionary processes
Authors: TOJU HIROKAZU , SOTA TEIJI 
Published: September 2009

AbstractOne of the major controversies in evolutionary biology concerns the processes underlying macroevolutionary patterns in which prolonged stasis is disrupted by rapid, short‐term evolution that leads species to new adaptive zones. Recent advances in the understanding of contemporary evolution have suggested that such rapid evolution can occur in the wild as a result of environmental changes. Here, we examined a novel hypothesis that evolutionary stasis is punctuated by co‐evolutionary arms races, which continuously alter adaptive peaks and landscapes. Based on the phylogeny of long‐mouthed weevils in the genus Curculio, likelihood ratio tests showed that the macroevolutionary pattern of the weevils coincides with the punctuational evolution model. A coalescent analysis of a species, Curculio camelliae, the mouthpart of which has diverged considerably among populations because of an arms race with its host plant, further suggested that major evolutionary shifts had occurred within 7000 generations. Through a microevolutionary analysis of the species, we also found that natural selection acting through co‐evolutionary interactions is potentially strong enough to drive rapid evolutionary shifts between adaptive zones. Overall, we posit that co‐evolution is an important factor driving the history of organismal evolution.
Leaf hydraulics and drought stress: response, recovery and survivorship in four woody temperate plant species
Authors: BLACKMAN CHRISTOPHER J. , BRODRIBB TIMOTHY J. , JORDAN GREGORY J. 
Published: September 2009

ABSTRACTEfficient conduction of water inside leaves is essential for leaf function, yet the hydraulic‐mediated impact of drought on gas exchange remains poorly understood. Here we examine the decline and subsequent recovery of leaf water potential (Ψleaf), leaf hydraulic conductance (Kleaf), and midday transpiration (E) in four temperate woody species exposed to controlled drought conditions ranging from mild to lethal. During drought the vulnerability of Kleaf to declining Ψleaf varied greatly among the species sampled. Following drought, plants were rewatered and the rate of E and Kleaf recovery was found to be strongly dependent on the severity of the drought imposed. Gas exchange recovery was strongly correlated with the relatively slow recovery of Kleaf for three of the four species, indicating conformity to a hydraulic‐stomatal limitation model of plant recovery. However, there was also a shift in the sensitivity of stomata to Ψleaf suggesting that the plant hormone abscisic acid may be involved in limiting the rate of stomatal reopening. The level of drought tolerance varied among the four species and was correlated with leaf hydraulic vulnerability. These results suggest that species‐specific variation in hydraulic properties plays a fundamental role in steering the dynamic response of plants during recovery.
Quality of life after radical prostatectomy in elderly men
Authors: Namiki Shunichi , Ishidoya Shigeto , Tochigi Tatsuo , Ito Akihiro , Arai Yoichi 
Published: September 2009

Objectives:  To evaluate the impact of radical prostatectomy (RP) on health‐related quality of life (HRQOL) in elderly men with prostate cancer.Methods:  Between January 2002 and December 2006, a total of 205 elderly men (≥70 years) undergoing RP participated in our longitudinal outcome study. Patients completed general (Short Form 36) and disease‐specific (University of California, Los Angeles Prostate Cancer Index) HRQOL questionnaires. A t‐test was used to compare each HRQOL score after RP with the baseline scores and Cox proportional hazard models to characterize the recovery trends.Results:  Patients undergoing RP showed physical problems, which diminished over time. Several emotional domains significantly improved during the follow‐up period. By 2 years postoperatively, 57% and 81% of subjects had fully returned to baseline urinary function and bother, respectively. Mean recovery time to baseline urinary function and bother was 8.3 months and 4.7 months, respectively. When incontinence was defined as ‘no pad’, 82% of patients reported continence. Whereas only 25% of patients returned to the baseline sexual function level, 83% had reached baseline sexual bother. Among those returning to their own baseline scores, the mean recovery time was 10.9 months for sexual function and 5.3 months for sexual bother.Conclusions:  Selected elderly patients can achieve satisfactory functional outcomes after RP. These outcomes should be considered when decisions about treatment are made.
Adiponectin and testosterone in patients with symptoms of late‐onset hypogonadism: Is there a link?
Authors: Tsujimura Akira , Takada Shingo , Matsuoka Yasuhiro , Nakayama Jiro , Takao Tetsuya , Miyagawa Yasushi , Sonoda Mina , Nishizawa Hitoshi , Iwahashi Hiromi , Funahashi Tohru , Nonomura Norio , Okuyama Akihiko 
Published: September 2009

Objectives:  To examine the correlation between testosterone and adiponectin in symptomatic late‐onset hypogonadism (LOH) patients.Methods:  The study included 174 patients (>40 years old) with at least one LOH symptom and an Aging Male Symptoms score >26. The correlation between serum adiponectin levels and various factors was investigated by simple and multiple regression analyses. Serum adiponectin levels before and after testosterone replacement therapy (TRT) in 43 patients with serum free testosterone <11.8 pg/mL were also compared.Results:  Serum adiponectin levels increased with increased age (P < 0.01), decreased with increased body mass index (P < 0.01), and increased with increased sex hormone‐binding globulin (P < 0.01). Multiple regression analysis revealed that body mass index and sex hormone‐binding globulin were factors with an influence on serum adiponectin levels. However, no association between testosterone and adiponectin was found. In the 43 patients receiving TRT, serum adiponectin levels before and after TRT did not differ significantly.Conclusions:  Serum adiponectin is not related to serum testosterone in symptomatic LOH patients, suggesting that TRT in these subjects does not pose a higher risk of inducing a metabolic syndrome.
Motion opponency and transparency in the human middle temporal area
Authors: Garcia Javier O. , Grossman Emily D. 
Published: September 2009

AbstractMotion transparency is the perception of multiple, moving surfaces within the same retinal location (for example, a ripple on the surface of a drifting stream), and is an interesting challenge to motion models because multiple velocities must be represented within the same region of space. When these motion vectors are in opposite directions, brief in duration and spatially constrained within a very local region, the result is little or no perceived motion (motion opponency). Both motion transparency and motion opponency inhibit the firing rate of single middle temporal area (MT) neurons as compared with the preferred direction alone, but neither generally influences the firing rate of primary visual cortex neurons. Surprisingly, neuroimaging studies of human middle temporal area (hMT+) have found less activation due only to motion opponency and an increase in neural responses for motion transparency. Here we parametrically manipulate the local balance between competing motion vectors and find an interaction between motion opponency and transparency in the population blood oxygen level‐dependent (BOLD) response. We find reduced BOLD amplitude for motion opponency throughout visual cortex, but weakened responses due to perceptual transparency that is most apparent only within the hMT+. We interpret our results as evidence for two distinct mechanisms mediating opponency and transparency.