bluuebunny/crossref_metadata_2025 huggingface dataset:
Villagers' Representative Assemblies: Towards Democracy or Centralism?
Authors: Chan Sylvia
Published: September 2005

Villagers' Representative Assemblies are playing an increasingly important role in village self-governance. In many villages, they are gradually superseding the Villagers' Assemblies and wielding powers that are supposed to be the latter's prerogatives. The creation of these assemblies is said to strengthen the supervision of power-holders by villagers through their representatives. This article argues that, contrary to their supporters' belief, these assemblies are mostly undemocratically constituted and subservient to village Party branches and Villagers' Committees. They are thus unable to check and balance the power of the Party and executive bodies in villages. The article also suggests ways to reform these assemblies.
The Quest for Good Governance: Hong Kong's Principal Officials Accountability System
Authors: Cheung Chor-yung
Published: September 2005

The second Tung Chee-hwa Administration in Hong Kong introduced the Principal Officials Accountability System (POAS) in July 2002 to enhance the quality of governance and accountability of its principal officials. A team of politically appointed principal officials replaced senior career civil servants as final decision-makers in the government. The co-option of two political party chairmen into the cabinet heralds the beginning of coalition politics, whereby the executive branch attempts to forge an alliance with some political parties in the legislature. However, owing to the undemocratic nature of the POAS, in which principal officials are responsible to the Chief Executive, not the public, it is doubtful if the POAS will improve the quality of governance in Hong Kong's open and pluralistic society.
Household Decisions and Gender Inequality in Education in Rural China
Authors: Li Danke , Tsang Mun C
Published: September 2005

This study employs a multidisciplinary approach to understand household education decisions and their implications for gender inequality in education in rural China. Based on a household survey of poor rural counties in Gansu and Hebei and local accounts, the study finds that parents have higher educational expectations for boys than for girls. Household education spending is a heavy economic burden for poor rural households, and school non-attendance rates are higher for girls than for boys in the majority of the counties. School attendance is related to economic burden, gender and other factors, but the relationship differs across the counties.
Parasites or Civilisers: The Legitimacy of the Chinese Communist Party in Rural Areas
Authors: Thogersen Stig
Published: September 2005

The Communist Party of China is fighting hard to redefine its basis of legitimacy and give village and township cadres and ordinary Party members a sense of purpose and direction. It is trying to redefine itself as an elite party whose cadres are better educated, more cultured and civilised, and have better organisational abilities than the rest of the rural population; but these views are being seriously challenged by the peasants. This paper is based on a study of Xuanwei County, Yunnan Province.
China's Outward Direct Investment: Expanding Worldwide
Authors: Wong John , Chan Sarah
Published: September 2005

China has become a capital-surplus economy and its overseas investment has grown apace. Although its outward investment is still small in absolute terms, especially compared to the huge inward flow, China's overseas enterprises have been quietly gaining importance as new sources of international capital. They are now globally diversified and involved in a wide variety of sectors, including banking, manufacturing and natural resource exploitation. In the coming years, Chinese outward investment is expected to accelerate. The free trade agreement signed between ASEAN and China will no doubt intensify Chinese outward investment to the region.
Problems of Knowledge and Authority in the Pseudo-Clementine Romance of Recognitions
Authors: Kelley Nicole
Published: September 2005

The Pseudo-Clementines are important texts in their own right, not mere repositories of earlier Christian sources. Analysis of one layer of the Recognitions, known as the "romance of recognitions," reveals that it is part of a narrative argument about knowledge and authority related to the Recognitions' larger polemical agenda: along with other parts of the story line, it shows that the Apostle Peter has supreme authority because of his knowledge of human and divine things. This insistence on Peter's authority makes sense in light of the Recognitions' fourth-century Syrian context, where Christians devoted to Peter's memory competed with other religious groups.
Porphyry on Christians and Others: "Barbarian Wisdom," Identity Politics, and Anti-Christian Polemics on the Eve of the Great Persecution
Authors: Schott Jeremy M.
Published: September 2005

This paper argues that we can better appreciate the motivations behind Porphyry of Tyre's anti-Christian polemics if they are placed in the context of his larger philosophical project. Porphyry's investigations of "foreign" religions and philosophies were based on asymmetrical distinctions between Greeks and barbarians that paralleled, and in many cases dovetailed with, the division of the Roman Empire into metropolitan center and provincial periphery. Christian intellectuals, however, imitated Porphyry's project in ways that disrupted these distinctions. Porphyry's polemics were motivated by a need to contain the threat that this disruption posed to the social and material privilege he enjoyed as a Greek philosopher in the Roman Empire. By situating Porphyry's polemics in the contexts of imperial power and subjugation, this paper challenges the divisions between "philosophical" and "political" fields of knowledge and action that underlie many discussions of political and religious change in late antiquity.
Pictures in Dialogue: A Viewer-Centered Approach to the Hypogeum on Via Dino Compagni
Authors: Snyder H. Gregory
Published: September 2005

This essay shifts the locus of meaning-making from painter and painting toward the viewer, specifically with reference to paintings in the Hypogeum on Via Dino Compagni. I argue that a viewer seeing paintings simultaneously or in series would sense conversations between pictures, in part because the process of linking pictures is analogous to the linking of disparate scriptural texts in homiletic practice. Approaching the closely juxtaposed paintings of Hercules, Moses, and Christ from this dialogical perspective allows us to characterize their relationship more richly than describing it as either syncretistic or conflictual.
Temperature-Dependent Raman Spectroscopic Study of the Nematic Liquid Crystal 4-n-Pentyl-4′-Cyanobiphenyl
Authors: Kang Dae Seung , Kwon Ki-Sun , Kim Sung Il , Gong Myoung-Seon , Seo Sung Seok A. , Noh Tae Won , Joo Sang-Woo
Published: September 2005

The spectral behaviors of 4- n-pentyl-4′-cyanobiphenyl (5CB) have been studied by means of temperature-dependent Raman spectroscopy in the range between −70 and 70 °C. The v(C≡N) bands in the Raman spectra were found splitting below the transition temperature from the solid to the nematic liquid crystalline phase at ∼24 °C, suggesting the existence of solid crystalline polymorphism. The interfacial structures of 5CB on metal plate surfaces have been reexamined by surface-enhanced Raman scattering (SERS) at different temperatures. On Ag and Au, the asymmetric shapes of the v(C≡N) bands suggest that there should exist different binding schemes for 5CB on metal surfaces. These asymmetric bands in the v(C≡N) stretching region were found to vary in changing temperature.
Stress-Induced Crystal-to-Crystal Transformations in High-Density Polyethylene-Layered Silicate Nanocomposites: A Spectroscopic Study
Authors: Tzavalas Spiros , Gregoriou Vasilis G.
Published: September 2005

High-density polyethylene (HDPE)–clay nanocomposites have been prepared using the melt intercalation technique. Organically modified montmorillonite at various loadings (0.5–7%) was used as a nanoadditive. Fourier transform infrared spectroscopy (FT-IR) was utilized for the first time to monitor the stress-induced crystal-to-crystal transformations of the polyethylene matrix with respect to the clay loading as well as to the degree of mechanical strain. In addition, polarized infrared measurements revealed information on both the orientation and the stress-induced distortion of the crystals. It was concluded that the crystal-to-crystal transformations are hindered by the presence of the clay, which also prevented the crystals from orienting even at low clay loadings (1%). Finally, X-ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements confirmed the presence of the stress-induced crystalline structures in agreement with the infrared measurements.
Determination of Carbon in Steel by Laser-Induced Breakdown Spectroscopy Using a Microchip Laser and Miniature Spectrometer
Authors: Wormhoudt J. , Iannarilli F. J. , Jones S. , Annen K. D. , Freedman A.
Published: September 2005

Laser-induced breakdown spectroscopy using a microchip laser and a miniature spectrometer has been applied to the determination of carbon in steel. The goal was to investigate the capability of an apparatus, made up of commercial components, that could form the basis of a handheld device. The typical precision obtained in the range of C/Fe weight ratios of 0.001 to 0.01 was 4.3%, and the limit of detection was a C/Fe ratio of 400 ppm. This is higher than values reported for conventional systems and is primarily determined by systematic variations in the spectra and not by signal intensity levels. These systematic variations are ascribed to two causes: the use of an ungated detector and the spatial variability of the emission plume.
Calcium Fluoride Micro Cells for Synchrotron Radiation Circular Dichroism Spectroscopy
Authors: Wien F. , Wallace B. A.
Published: September 2005

Demountable calcium fluoride micro cells have been developed for use in synchrotron radiation circular dichroism (SRCD) spectroscopy. They have the advantages that they require only very small sample volumes (as low as 1 microliter) and have short path lengths (as small as 2 micrometers). Highly reproducible spectra can be obtained in consecutive loadings with these spacer-free, fixed path length cells, which enable low wavelength data collection.
Transflectance Spectra of Faceted Diamonds Acquired by Infrared Microscopy
Authors: Ekgasit Sanong , Thongnopkun Pimthong
Published: September 2005

A novel transflectance technique using an infrared microscope was employed for spectral acquisition of loose and mounted faceted diamonds. The observed transflectance spectrum shows the same spectral features as those of the well-accepted diffuse reflectance spectrum. Unlike the diffuse reflectance spectrum, the transflectance spectrum was not affected by the diamond arrangements. The technique can be employed for direct spectra acquisition of mounted diamonds without taking the diamonds out of the jewelry bodies. Moreover, an individual diamond on a complex jewelry setting can be selectively measured. Infrared absorption bands unique to the chemical compositions, impurities, and treatment processes of the diamonds are discussed. The observed transflectance spectra can be exploited for diamond classification.
Enantiomeric Excess Determination by Fourier Transform Near-Infrared Vibrational Circular Dichroism Spectroscopy: Simulation of Real-Time Process Monitoring
Authors: Guo Changning , Shah Rekha D. , Dukor Rina K. , Cao Xiaolin , Freedman Teresa B. , Nafie Laurence A.
Published: September 2005

The first use of near-infrared (NIR) Fourier transform vibrational circular dichroism (FT-VCD) to follow changes in the enantiomeric excess (EE) of chiral sample molecules in time using a flow-cell sampling apparatus is reported. Simultaneous changes in the fractional composition and the EE of a mixture of two different chiral molecules were monitored as a function of time. This simulates the progress of the chemical reaction from a chiral reactant to a chiral product where the mole fractions and EE values of both species may change with time. For the molecules studied, α-pinene, camphor, and borneol, the accuracy of following EE changes for one species alone is approximately 2%, while for simultaneously following EE changes in two species it is approximately 3% for 30 min sampling periods at 16 cm−1 spectral resolution. These findings demonstrate the potential for VCD to be used in the NIR region for real-time monitoring of the composition and %EE of chemical reactions involving the synthesis of chiral molecules.
Detection of the Molecular Changes Associated with Oral Cancer Using a Molecular-Specific Fluorescent Contrast Agent and Single-Wavelength Spectroscopy
Authors: Hsu Elizabeth R. , Gillenwater Ann M. , Richards-Kortum Rebecca R.
Published: September 2005

There is currently no standard screening technique for oral cancer and its precursors other than visual identification and biopsy of suspicious lesions. To aid noninvasive early detection of oral neoplasia in vivo, we previously developed a molecular-specific contrast agent targeted against epidermal growth factor receptor. Here, we present a simple fluorescence spectroscopy system to detect the presence of this contrast agent in biological models representative of living tissues in order to demonstrate the feasibility of using a spectroscopy system in conjunction with a contrast agent as a screening technique for oral cancer. The spectroscopy system was tested for the ability to detect the contrast agent in four in vitro models: multilayer tissue phantoms made of cells pre-labeled with the contrast agent, multilayer tissue phantoms labeled with the contrast agent from the surface in conjunction with a permeability-enhancing agent, fresh tissue slices from normal and abnormal oral cavity biopsies, and whole normal and abnormal oral cavity biopsies. The optical signal from samples labeled with the contrast agent was 3–32 times stronger compared to controls and was detected with a signal-to-noise ratio greater than 10. These results demonstrate that an inexpensive and simple spectroscopy system can be used in biological models of living systems to detect the optical signal from a contrast agent targeted toward a cancer-related biomarker with good signal-to-noise ratios. Coupling inexpensive fluorescence spectrometers with molecular-specific contrast agents has the potential to improve the early detection of oral neoplasia by providing a low-cost screening tool.
Transmittance Fourier Transform Infrared Spectra of Liquid Water in the Whole Mid-Infrared Region: Temperature Dependence and Structural Analysis
Authors: Freda M. , Piluso A. , Santucci A. , Sassi P.
Published: September 2005

Transmittance Fourier transform infrared (FT-IR) spectra of liquid water in the 4–80 °C temperature range are reported in the whole mid-infrared (MIR) region (4000–360 cm−1). The spectra were recorded by using a newly developed, home-made transmittance cell, working in light vacuum conditions (pressures of the order of 3–4 millibar). This permits the elimination of the aqueous vapor bands from the liquid spectra, particularly in the bending region, and the rapid collection of data without fluxing large amounts of nitrogen through the interferometer sample chamber. The temperature evolution of the OH stretching and HOH deformation bands is discussed in terms of Gaussian components analysis and a two-state model describing the equilibrium between different H-bond structures of liquid water. From this picture, structural and thermodynamic information about the hydrogen-bonding network of water is obtained.
Experimental Aspects of Asynchronous Rapid-Scan Fourier Transform Infrared Imaging
Authors: Snively Christopher M. , Lauterbach Jochen
Published: September 2005

In the asynchronous, rapid-scan approach to Fourier transform infrared (FT-IR) imaging, data sampling is not correlated with the zero crossings of the interference fringes of the HeNe reference laser. The success of this data collection scheme depends on the reproducibility of the clock signals driving the interferometer mirror and focal plane array data collection. In previous studies, it was shown that this implementation provides for markedly faster data acquisition without sacrificing data quality, as compared with step-scan imaging. This approach to data collection introduces some unique peculiarities to the acquisition and processing of imaging data. The purpose of this paper is to address a few of these concerns in terms of their effect on final data quality. Also, the practical aspects of implementing such an acquisition scheme are described in detail.
Identification of Recently Handled Materials by Analysis of Latent Human Fingerprints Using Infrared Spectromicroscopy
Authors: Grant Ashleigh , Wilkinson T. J. , Holman Derek R. , Martin Michael C.
Published: September 2005

Analysis of fingerprints has predominantly focused on matching the pattern of ridges to a specific person as a form of identification. The present work focuses on identifying extrinsic materials that are left within a person's fingerprint after recent handling of such materials. Specifically, we employed infrared spectromicroscopy to locate and positively identify microscopic particles from a mixture of common materials in the latent human fingerprints of volunteer subjects. We were able to find and correctly identify all test substances based on their unique infrared spectral signatures. Spectral imaging is demonstrated as a method for automating recognition of specific substances in a fingerprint. We also demonstrate the use of attenuated total reflectance (ATR) and synchrotron-based infrared spectromicroscopy for obtaining high-quality spectra from particles that were too thick or too small, respectively, for reflection/absorption measurements. We believe the application of this rapid, nondestructive analytical technique to the forensic study of latent human fingerprints has the potential to add a new layer of information available to investigators. Using fingerprints to not only identify who was present at a crime scene, but also to link who was handling key materials, will be a powerful investigative tool.
Updating Multivariate Calibrations with the Delaunay Triangulation Method
Authors: Jin L. , Xu Q. S. , Smeyers-Verbeke J. , Massart D. L.
Published: September 2005

Multivariate calibrations must be updated when new samples show different spectral characteristics. In this paper, we discuss how to do this when the calibration is performed with a topological multivariate calibration method based on Delaunay triangulation (DT). The updating leads either to the expansion of the original calibration set or to the creation of a new local model. Outliers in the new samples with respect to the original calibration set are first detected and divided in two groups, namely, marginal outliers, which are considered to be extensions of the calibration set and are used for updating the calibration set, and true outliers. If a sufficient number of true outliers are found to be situated close enough to each other, they can form the basis for a new local model. Several updating simulations performed on a real data set show that the updating procedure performs well. The results for prediction with the DT method after updating are comparable to or better than those after updating with partial least squares (PLS) and it is concluded that, in many cases, the DT method is a valuable alternative for multivariate calibration.
Continuous-Wave-Laser versus Pulsed-Laser Excitation for Crossed-Beam Photothermal Detection in Small Volume Applications: Comparative Features
Authors: Georges Joseph
Published: September 2005

Crossed-beam thermal lens spectrometry can be implemented using continuous-wave- (cw) laser or pulsed-laser excitation. In both cases, the signal depends on the position of the sample with respect to the probe beam waist, the size of the excitation beam, the beam-size ratio into the sample, and the power or energy of the excitation beam. However, due to differences in the rate of formation and relaxation of the thermal lens, both methods exhibit distinct key features. Optimization of the experimental setup and understanding the thermal lens signal are more complicated under cw-laser excitation than with pulsed-laser excitation. Unlike that observed under pulsed excitation, the effect of the excitation beam waist, of the sample size, and of the flow rate are closely related to the effective size of the thermal element and depend on the chopping frequency. Although the intrinsic sensitivities are almost the same, the performance can significantly differ depending on the chopping frequency or pulse repetition rate, which should be high enough to allow fast data collection and efficient signal averaging.
Fluorescence Lifetime Imaging and Fourier Transform Infrared Spectroscopy of Michelangelo's David
Authors: Comelli Daniela , Valentini Gianluca , Cubeddu Rinaldo , Toniolo Lucia
Published: September 2005

We developed a combined procedure for the analysis of works of art based on a portable system for fluorescence imaging integrated with analytical measurements on microsamples. The method allows us to localize and identify organic and inorganic compounds present on the surface of artworks. The fluorescence apparatus measures the temporal and spectral features of the fluorescence emission, excited by ultraviolet (UV) laser pulses. The kinetic of the emission is studied through a fluorescence lifetime imaging system, while an optical multichannel analyzer measures the fluorescence spectra of selected points. The chemical characterization of the compounds present on the artistic surfaces is then performed by means of analytical measurements on microsamples collected with the assistance of the fluorescence maps. The previous concepts have been successfully applied to study the contaminants on the surface of Michelangelo's David. The fluorescence analysis combined with Fourier transform infrared (FT-IR) measurements revealed the presence of beeswax, which permeates most of the statue surface, and calcium oxalate deposits mainly arranged in vertical patterns and related to rain washing.
Laser-Induced Breakdown Spectroscopy Analysis of Solids Using a Long-Pulse (150 ns) Q-Switched Nd:YAG Laser
Authors: Yamamoto Karen Y. , Cremers David A. , Foster Leeann E. , Davies Mathew P. , Harris Ronny D.
Published: September 2005

Laser-induced breakdown spectroscopy (LIBS) measurements are typically carried out using pulses (<20 ns, >50 mJ) from a flash-lamp-pumped electro-optically Q-switched Nd:YAG laser (EO-laser) or excimer laser. Here we report LIBS analyses of solids using an acousto-optically Q-switched Nd:YAG laser (AO-laser) producing 150 ns pulses of lower energy (10 mJ) at repetition rates up to 6 kHz. The high repetition rate allows increased spatial or depth sampling over a given time period compared to the EO-laser. Results of AO-laser based LIBS analysis of (1) steels, (2) soils, and (3) surface stains and dusts are described. Detection limits for Cr, Cu, Mn, Ni, and Si in steel ranged from 0.11 to 0.24% using a commercial polychromator-based detection system with limits 4–30 times lower achieved using a laboratory-based detection system. The minimum detectable masses of Ba, Cr, Mn, and Sr on a metal surface were estimated with 1.2 pg/shot achieved for Sr. Detection limits for Ba and Sr in soil were 296 and 52 ppm, respectively. The temperatures, spectra, and emission decay curves from plasmas generated by the AO- and EO-lasers are compared and some characteristics of particles ablated by the AO-laser are described.
Estimation of Crystallinity in Isotropic Isotactic Polypropylene with Raman Spectroscopy
Authors: Minogianni Chrysa , Gatos Konstantinos G. , Galiotis Costas
Published: September 2005

The Raman spectrum of isotactic polypropylene (iPP) has been found to exhibit vibrational peaks in the region of 750 to 880 cm−1 that are sensitive to the degree of crystallinity. These features are broadly assigned to various modes of methyl group rocking, ρ(CH2), and there have been various attempts to assess crystallinity based on the integrated intensities of these bands. Various vibrational analyses performed in the past in combination with experimental studies have concluded that the presence of crystalline order with trans-gauche conformation gives rise to a peak at 809 cm−1, which is assigned to a ρ(CH2) mode coupled with the skeletal stretching mode. However, the presence of additional peaks at 830 cm−1, 841 cm−1, and 854 cm−1, within the same envelope, have been the subject of controversy. In this work isotropic films of iPP derived from the same precursor of identical tacticity have been subjected to various degrees of annealing and the integrated intensities of the Raman bands were measured. The results showed that true 3d crystallinity in isotropic iPP can only be expressed by the 809 cm−1 band whereas the band at 841 cm−1 corresponds to an uncoupled ρ(CH2) fundamental mode and thus is a measure of the amorphous content. The less intense satellite bands at 830 cm−1 and 854 cm−1 of solid iPP cannot be distinguished from the 841 cm−1 band in the melt and are generally considered as intermediate phases possibly related to non-crystalline components with 31-helical conformations. Independent differential scanning calorimetry (DSC) crystallinity measurements were in broad agreement with the Raman measurements based on the normalized intensity of the 809 cm−1 Raman band. By comparing the Raman with the DSC data a new value for the theoretical heat of fusion for the 100% crystalline iPP has been proposed.
Improvement of Mapping Accuracy by Unifying Linkage and Association Analysis
Authors: Lou Xiang-Yang , Ma Jennie Z , Yang Mark C K , Zhu Jun , Liu Peng-Yuan , Deng Hong-Wen , Elston Robert C , Li Ming D
Published: September 2005

It is well known that pedigree/family data record information on the coexistence in founder haplotypes of alleles at nearby loci and the cotransmission from parent to offspring that reveal different, but complementary, profiles of the genetic architecture. Either conventional linkage analysis that assumes linkage equilibrium or family-based association tests (FBATs) capture only partial information, leading to inefficiency. For example, FBATs will fail to detect even very tight linkage in the case where no allelic association exists, while a violation of the assumption of linkage equilibrium will result in biased estimation and reduced efficiency in linkage mapping. In this article, by using a data augmentation technique and the EM algorithm, we propose a likelihood-based approach that embeds both linkage and association analyses into a unified framework for general pedigree data. Relative to either linkage or association analysis, the proposed approach is expected to have greater estimation accuracy and power. Monte Carlo simulations support our theoretical expectations and demonstrate that our new methodology: (1) is more powerful than either FBATs or classic linkage analysis; (2) can unbiasedly estimate genetic parameters regardless of whether association exists, thus remedying the bias and less precision of traditional linkage analysis in the presence of association; and (3) is capable of identifying tight linkage alone. The new approach also holds the theoretical advantage that it can extract statistical information to the maximum extent and thereby improve mapping accuracy and power because it integrates multilocus population-based association study and pedigree-based linkage analysis into a coherent framework. Furthermore, our method is numerically stable and computationally efficient, as compared to existing parametric methods that use the simplex algorithm or Newton-type methods to maximize high-order multidimensional likelihood functions, and also offers the computation of Fisher's information matrix. Finally, we apply our methodology to a genetic study on bone mineral density (BMD) for the vitamin D receptor (VDR) gene and find that VDR is significantly linked to BMD at the one-third region of the wrist.
Fine Mapping and Physical Characterization of Two Linked Quantitative Trait Loci Affecting Milk Fat Yield in Dairy Cattle on BTA26
Authors: Gautier Mathieu , Barcelona Rosa Roy , Fritz Sébastien , Grohs Cécile , Druet Tom , Boichard Didier , Eggen André , Meuwissen Theo H E
Published: September 2005

Previously, a highly significant QTL affecting fat yield and protein yield and mapped to the bovine BTA26 chromosome has been reported to segregate in the French Holstein cattle population. To confirm and refine the location of this QTL, the original detection experiment was extended by adding 12 new families and genotyping 25 additional microsatellite markers (including 11 newly developed markers). Data were then analyzed by an approach combining both linkage and linkage disequilibrium information, making it possible to identify two linked QTL separated by 20 cM corresponding to ∼29 Mb. The presence of a QTL affecting protein yield was confirmed but its position was found to be more telomeric than the two QTLunderlying fat yield. Each identified QTL affecting milk fat yield was physically mapped within a segment estimated to be <500 kb. Two strong functional candidate genes involved, respectively, in fatty acid metabolism and membrane permeability were found to be localized within this segment while other functional candidate genes were discarded. A haplotype comprising the favorable allele at each QTL position appears to be overrepresented in the artificial insemination bull population.
High-Resolution Association Mapping of Quantitative Trait Loci: A Population-Based Approach
Authors: Fan Ruzong , Jung Jeesun , Jin Lei
Published: September 2005

In this article, population-based regression models are proposed for high-resolution linkage disequilibrium mapping of quantitative trait loci (QTL). Two regression models, the “genotype effect model” and the “additive effect model,” are proposed to model the association between the markers and the trait locus. The marker can be either diallelic or multiallelic. If only one marker is used, the method is similar to a classical setting by Nielsen and Weir, and the additive effect model is equivalent to the haplotype trend regression (HTR) method by Zaykin et al. If two/multiple marker data with phase ambiguity are used in the analysis, the proposed models can be used to analyze the data directly. By analytical formulas, we show that the genotype effect model can be used to model the additive and dominance effects simultaneously; the additive effect model takes care of the additive effect only. On the basis of the two models, F-test statistics are proposed to test association between the QTL and markers. By a simulation study, we show that the two models have reasonable type I error rates for a data set of moderate sample size. The noncentrality parameter approximations of F-test statistics are derived to make power calculation and comparison. By a simulation study, it is found that the noncentrality parameter approximations of F-test statistics work very well. Using the noncentrality parameter approximations, we compare the power of the two models with that of the HTR. In addition, a simulation study is performed to make a comparison on the basis of the haplotype frequencies of 10 SNPs of angiotensin-1 converting enzyme (ACE) genes.
The Genetic Architecture of Sucrose Responsiveness in the Honeybee (Apis mellifera L.)
Authors: Rueppell Olav , Chandra Sathees B C , Pankiw Tanya , Fondrk M Kim , Beye Martin , Hunt Greg , Page Robert E
Published: September 2005

One of the best examples of a natural behavioral syndrome is the pollen-hoarding syndrome in honeybees that ties together multiple behavioral phenotypes, ranging from foraging behavior to behavioral ontogeny and learning performance. A central behavioral factor is the bees' responsiveness to sucrose, measured as their proboscis extension reflex. This study examines the genetics of this trait in diploid worker and haploid male honeybees (drones) to learn more about the genetic architecture of the overall behavioral syndrome, using original strains selected for pollen-hoarding behavior. We show that a significant proportion of the phenotypic variability is determined by genotype in males and workers. Second, our data present overwhelming evidence for pleiotropic effects of previously identified quantitative trait loci for foraging behavior (pln-QTL) and epistatic interactions among them. Furthermore, we report on three genomic QTL scans (two reciprocal worker backcrosses and one drone hybrid population) derived from our selection strains. We present at least one significant and two putative new QTL directly affecting the sucrose response of honeybees. Thus, this study demonstrates the modular genetic architecture of behavioral syndromes in general, and elucidates the genetic architecture of the pollen-hoarding behavioral syndrome in particular. Understanding this behavioral syndrome is important for understanding the division of labor in social insects and social evolution itself.
Genomewide Nonadditive Gene Regulation in Arabidopsis Allotetraploids
Authors: Wang Jianlin , Tian Lu , Lee Hyeon-Se , Wei Ning E , Jiang Hongmei , Watson Brian , Madlung Andreas , Osborn Thomas C , Doerge R W , Comai Luca , Chen Z Jeffrey
Published: September 2005

Polyploidy has occurred throughout the evolutionary history of all eukaryotes and is extremely common in plants. Reunification of the evolutionarily divergent genomes in allopolyploids creates regulatory incompatibilities that must be reconciled. Here we report genomewide gene expression analysis of Arabidopsis synthetic allotetraploids, using spotted 70-mer oligo-gene microarrays. We detected >15% transcriptome divergence between the progenitors, and 2105 and 1818 genes were highly expressed in Arabidopsis thaliana and A. arenosa, respectively. Approximately 5.2% (1362) and 5.6% (1469) genes displayed expression divergence from the midparent value (MPV) in two independently derived synthetic allotetraploids, suggesting nonadditive gene regulation following interspecific hybridization. Remarkably, the majority of nonadditively expressed genes in the allotetraploids also display expression changes between the parents, indicating that transcriptome divergence is reconciled during allopolyploid formation. Moreover, >65% of the nonadditively expressed genes in the allotetraploids are repressed, and >94% of the repressed genes in the allotetraploids match the genes that are expressed at higher levels in A. thaliana than in A. arenosa, consistent with the silencing of A. thaliana rRNA genes subjected to nucleolar dominance and with overall suppression of the A. thaliana phenotype in the synthetic allotetraploids and natural A. suecica. The nonadditive gene regulation is involved in various biological pathways, and the changes in gene expression are developmentally regulated. In contrast to the small effects of genome doubling on gene regulation in autotetraploids, the combination of two divergent genomes in allotetraploids by interspecific hybridization induces genomewide nonadditive gene regulation, providing a molecular basis for de novo variation and allopolyploid evolution.
The Influence of Loss of Bone Mass on Induced Periodontal Disease: A Radiographic and Densitometric Study of Female Rats
Authors: Orrico Silvana Regina Perez , Gonçalves Daniela , Galeazzi Solange Teresinha , Giro Gabriela , Takayama Lilian , Pereira Rosa Maria Rodrigues
Published: September 2005

Background: Changes in mineral density in the mandibular and femoral bones (BMD) after estrogen deficiency caused by ovariectomy (OVX) and the influence of these changes on induced periodontal disease were evaluated in female rats.

Methods: Forty‐eight female Holtzman rats (90 days old) were randomly divided into five groups: 0: control (N = 9); 1: SHAM without induced periodontal disease (N = 11); 2: SHAM with induced disease (N = 10); 3: OVX without induced disease (N = 9); and 4: OVX with induced disease (N = 9). In groups 2 and 4, the first lower molars were tied with ligatures for 30 days 120 days after surgery. After 5 months the animals were sacri‐ ficed to measure global mineral density (BMD) and that of the sub‐regions of the mandible and femur by dual energy x‐ray absorptiometry (DXA). The extent of vertical bone loss was evaluated with digital radiography by measuring the distance from the bone crest to the cemento‐enamel junction at the mesial of the first lower molar.

Results: Results of the femur (Kruskal‐Wallis test) showed a significant difference (P <0.001) between the groups SHAM and OVX in bone density values for all regions. Comparison between the groups in relation to the BMD of the mandible, both in the sub‐regions and global revealed no differences (P >0.05). The vertical bone loss measured for the groups with induced disease was similar (P = 0.713).

Conclusions: Differences between the groups were found in the bone mineral density BMD of the femur but not of the mandible. OVX had no influence on induced periodontal disease. J Periodontol 2005;76:1436‐1442.
A Laboratory Model Biofilm Fermenter: Design and Initial Trial on a Single Species Biofilm
Authors: Wirthlin M. Robert , Chen Pengjen Kevin , Hoover Charles I.
Published: September 2005

Background: The minimum inhibitory concentration (MIC) does not provide information on the efficacy of antimicrobial agents against infections involving biofilms, which are many times more resistant than planktonic forms of bacteria. This report is on the design and initial trial of a device for growing standard biofilms and testing antimicrobial agents.

Methods: We constructed a durable, autoclaveable laboratory model biofilm fermenter (LMBF) that holds hydroxyapatite discs 300 µm below a surface onto which an artificial saliva medium drips at a rate comparable to human salivary flow. Inoculated with Streptococcus sanguinis, the device formed biofilms that were swept with a Teflon wiper under aerobic conditions. Five‐day‐old biofilm‐coated discs were aseptically removed and placed in 3 ml of sterile saline, 0.12% chlorhexidine gluconate, or 0.1% phosphatebuffered chlorine dioxide mouthwash for 1 minute. The discs and test agent were immediately diluted with saline to 10 ml, vortexed for 30 seconds, serially diluted, plated on blood agar, and incubated anaerobically 2 days. Bacterial counts were done, and the MIC of each mouthwash was determined.

Results: In tests with sterile water and sterile medium, the device maintained a closed system. After inoculation with S. sanguinis, a steady state was reached at day 5. Chlorhexidine at stock concentration achieved about a 2 log10 reduction (P = 0.002), but never achieved complete killing. Chlorine dioxide had no significant effect. The MIC against planktonic S. sanguinis was 112.8 µg/ml for chlorhexidine and 9.0 µg/ml for chlorine dioxide.

Conclusions: The LMBF generates and maintains a singlespecies oral model biofilm to a steady state and enables in vitro tests of disinfectant mouthwashes in simulated clinical use. It should be useable for more advanced tests of multiple species biofilms. J Periodontol 2005;76:1443‐1449.
Prevalence of Clinical Attachment Loss in Adolescents in Santo Domingo, Dominican Republic
Authors: Collins James , Carpio Ana Maria , Bobadilla Mónica , Reyes Raysa , Gúzman Isabel , Martínez Benjamín , Gamonal Jorge
Published: September 2005

Background: Data on periodontal conditions in adolescents in the Dominican Republic are scarce. The aim of the present crosssectional study was to estimate the prevalence of periodontal attachment loss among Dominican adolescents. This study did not attempt to classify the disease into aggressive and chronic periodontitis.

Methods: A random sample of 2,007 Dominican adolescents was obtained. A probability, weighted sample was selected using a complex, multi‐stage probability sampling design. The study was clustered in 26 schools and 106 classes. The study subjects were clinically examined under field conditions by a single calibrated examiner who measured gingival recession and probing depth at six sites per tooth, with subsequent calculation of clinical periodontal attachment level for each site.

Results: The prevalence of clinical attachment loss ≥1 mm was 49.5%, with the prevalence ranging between 48.7% and 50.2%, depending on age and gender. Clinical attachment loss ≥2 mm was found in 15% of the students and attachment loss ≥3 mm in 4.0% of the students. Logistic regression model revealed that only age significantly increased the probability of having clinical attachment loss.

Conclusion: We conclude that clinical attachment loss is common in adolescents in Santo Domingo, Dominican Republic, suggesting the necessity for improved standards of prevention, diagnosis, and treatment of these lesions. J Periodontol 2005;76: 1450‐1454.
The Relationship Between Interleukin‐10 Gene Polymorphism at Position –1082 and Susceptibility to Gingivitis in Children
Authors: Dashash M. , Blinkhorn A.S. , Hutchinson I.V. , Pravica V. , Drucker D.B.
Published: September 2005

Background: Interleukin (IL)‐10 is an anti‐inflammatory cytokine. The protective role of this cytokine against different diseases has been demonstrated in several studies. However, no such study has been carried out on gingivitis. The objective of this study was to determine whether differences exist between Caucasian children with and without gingivitis in the distribution of IL‐10 alleles at position –1082.

Methods: A total of 260 Caucasian children (86 controls, 174 patients), aged 8 to 12 years, from the University Dental Hospital of Manchester, U.K., were examined. Plaque (PI), calculus (CI), gingival (GI), and bleeding on probing (BOP) indices were used to assess gingival health. DNA was obtained from buccal epithelial cells. Amplification refractory mutation system polymerase chain reaction (ARMS‐PCR) was used for genotyping IL‐10 polymorphism. Chi square tests were carried out to test the association between allele and genotype frequencies and the severity of gingivitis. Multiple logistic regression was used to determine the role of IL‐10 gene polymorphism at position –1082 while adjusting for potential confounders such as plaque, age, and gender.

Results: Gingivitis was present in 67% of the children examined. Frequencies of alleles –1082*A and –1082*G were 45% and 55%, respectively. An increased risk of having gingivitis was found in allele A positive children (G/A, A/A); 75% versus 25% in allele A negative children (G/G); (P = 0.01). The –1082*A allele was significantly more common in children with gingivitis; 49% versus 37% in controls (P = 0.01). Multivariate logistic regression analysis showed that allele A remained a risk factor for gingivitis in children (P = 0.03) regardless of plaque or age. Also, allele A positive children were at increased odds of having gingivitis of 1.8 (95% con‐ fidence interval [CI]: 1.05 to 3.06) compared to allele A negative children after adjusting for plaque, age, and gender.

Conclusion: These data suggest that the –1082*A allele could be a risk factor for gingivitis. J Periodontol 2005;76:1455‐1462.
Real‐Time Polymerase Chain Reaction for Detection and Quantification of Bacteria in Periodontal Patients
Authors: Nonnenmacher Claudia , Dalpke Alexander , Rochon Justine , Flores‐de‐Jacoby Lavin , Mutters Reinier , Heeg Klaus
Published: September 2005

Background: Accurate laboratory tests for the detection and quantification of periodontopathogens in subgingival plaque samples of periodontal disease patients are becoming essential to study the pathogenesis of this polymicrobial condition. We used a real‐time polymerase chain reaction (PCR) assay for the quantification of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Dialister pneumosintes, Campylobacter rectus, and Micromonas micros as well as total eubacteria in subgingival plaque samples from individuals with periodontitis.

Methods: Eighty‐three subgingival samples from periodontally diseased patients and 43 samples from periodontally healthy subjects were tested and the results of bacterial quantification were correlated to clinical parameters. Quantification was performed with specific 16S rRNA target sequences with double fluorescence labeled probes and serial dilutions of plasmid standards by real‐time PCR.

Results: Results showed that patients as well as healthy subjects were positive for the presence of target periodontopathogens; however, median values were higher in samples from periodontitis subjects. In addition, a positive association was observed between colonization at high levels by P. gingivalis and M. micros and the presence of deep periodontal pockets.

Conclusion: Real‐time PCR provides a reliable high‐throughput method for quantification of periodontopathogens and may be useful for understanding the complex etiology observed in periodontal diseases. J Periodontol 2005;76:1542‐1549.
Treatment of Gingival Fibromatosis Associated With Zimmermann‐Laband Syndrome
Authors: Holzhausen Marinella , Ribeiro Fernando Salimon , Gonçalves Daniela , Corrêa Fernanda Oliveira Bello , Spolidorio Luís Carlos , Perez Orrico Silvana Regina
Published: September 2005

Background: Gingival fibromatosis is a rare condition characterized by a generalized enlargement of the buccal and lingual aspects of the attached and marginal gingiva.

Methods: This case report describes the periodontal management of a 13‐year‐old female patient with gingival fibromatosis associated with Zimmermann‐Laband syndrome. The patient presented with gingival enlargement involving the maxillary and the mandibular arches, anterior open bite, and non‐erupted teeth. Periodontal treatment included gingivectomy in all four quadrants.

Results: Histopathologic evaluation of the excised tissue supported the diagnosis of gingival fibromatosis. A significant improvement in esthetic appearance and eruption of the non‐erupted teeth were obtained. The patient was referred for appropriate orthodontic treatment and has been closely followed for the earliest signs of recurrence of gingival enlargement.

Conclusions: The successful therapy for gingival fibromatosis depends on correctly identifying the etiological factors and improving the impaired function and esthetic appearance through surgical intervention and adjunctive orthodontics. Maintaining treatment results depends on preservation of periodontal health. J Periodontol 2005;76:1559‐1562.