bluuebunny/crossref_metadata_2025 huggingface dataset:
Automated Spectral Smoothing with Spatially Adaptive Penalized Least Squares
Authors: Urbas Aaron A. , Choquette Steven J.
Published: May 2011

A variety of data smoothing techniques exist to address the issue of noise in spectroscopic data. The vast majority, however, require parameter specification by a knowledgeable user, which is typically accomplished by trial and error. In most situations, optimized parameters represent a compromise between noise reduction and signal preservation. In this work, we demonstrate a nonparametric regression approach to spectral smoothing using a spatially adaptive penalized least squares (SAPLS) approach. An iterative optimization procedure is employed that permits gradual flexibility in the smooth fit when statistically significant trends based on multiscale statistics assuming white Gaussian noise are detected. With an estimate of the noise level in the spectrum the procedure is fully automatic with a specified confidence level for the statistics. Potential application to the heteroscedastic noise case is also demonstrated. Performance was assessed in simulations conducted on several synthetic spectra using traditional error measures as well as comparisons of local extrema in the resulting smoothed signals to those in the true spectra. For the simulated spectra, a best case comparison with the Savitzky–Golay smoothing via an exhaustive parameter search was performed while the SAPLS method was assessed for automated application. The application to several dissimilar experimentally obtained Raman spectra is also presented.
Detection of Copper in Water Using On-Line Plasma-Excited Atomic Absorption Spectroscopy (AAS)
Authors: Porento Mika , Sutinen Veijo , Julku Timo , Oikari Risto
Published: May 2011

A measurement method and apparatus was developed to measure continuously toxic metal compounds in industrial water samples. The method was demonstrated by using copper as a sample metal. Water was injected into the sample line and subsequently into a nitrogen plasma jet, in which the samples comprising the metal compound dissolved in water were decomposed. The transmitted monochromatic light was detected and the absorbance caused by copper atoms was measured. The absorbance and metal concentration were used to calculate sensitivity and detection limits for the studied metal. The sensitivity, limit of detection, and quantification for copper were 0.45 ± 0.02, 0.25 ± 0.01, and 0.85 ± 0.04 ppm, respectively.
Multimodal Spectral Imaging of Cells Using a Transmission Diffraction Grating on a Light Microscope
Authors: Isailovic Dragan , Xu Yang , Copus Tyler , Saraswat Suraj , Nauli Surya M.
Published: May 2011

A multimodal methodology for spectral imaging of cells is presented. The spectral imaging setup uses a transmission diffraction grating on a light microscope to concurrently record spectral images of cells and cellular organelles by fluorescence, darkfield, brightfield, and differential interference contrast (DIC) spectral microscopy. Initially, the setup was applied for fluorescence spectral imaging of yeast and mammalian cells labeled with multiple fluorophores. Fluorescence signals originating from fluorescently labeled biomolecules in cells were collected through triple or single filter cubes, separated by the grating, and imaged using a charge-coupled device (CCD) camera. Cellular components such as nuclei, cytoskeleton, and mitochondria were spatially separated by the fluorescence spectra of the fluorophores present in them, providing detailed multi-colored spectral images of cells. Additionally, the grating-based spectral microscope enabled measurement of scattering and absorption spectra of unlabeled cells and stained tissue sections using darkfield and brightfield or DIC spectral microscopy, respectively. The presented spectral imaging methodology provides a readily affordable approach for multimodal spectral characterization of biological cells and other specimens.
Sodium and Potassium Released from Burning Particles of Brown Coal and Pine Wood in a Laminar Premixed Methane Flame Using Quantitative Laser-Induced Breakdown Spectroscopy
Authors: Hsu Li-Jen , Alwahabi Zeyad T. , Nathan Graham J. , Li Yu , Li Z. S. , Aldén Marcus
Published: May 2011

A quantitative point measurement of total sodium ([Na]total) and potassium ([K]total) in the plume of a burning particle of Australian Loy Yang brown coal (23 ± 3 mg) and of pine wood pellets (63 ± 3 mg) was performed using laser-induced breakdown spectroscopy (LIBS) in a laminar premixed methane flame at equivalence ratios (Φ) of 1.149 and 1.336. Calibration was performed using atomic sodium or potassium generated by evaporation of droplets of sodium sulfite (Na2SO3) or potassium sulfate (K2SO4) solutions seeded into the flame. The calibration compensated for the absorption by atomic alkalis in the seeded flame, which is significant at high concentrations of solution. This allowed quantitative measurements of sodium (Na) and potassium (K) released into the flame during the three phases of combustion, namely devolatilization, char, and ash cooking. The [Na]total in the plume released from the combustion of pine wood pellets during the devolatilization was found to reach up to 13 ppm. The maximum concentration of total sodium ([Na]maxtotal) and potassium ([K]maxtotal) released during the char phase of burning coal particles for Φ = 1.149 was found to be 9.27 and 5.90 ppm, respectively. The [Na]maxtotal and [K]maxtotal released during the char phase of burning wood particles for Φ = 1.149 was found to be 15.1 and 45.3 ppm, respectively. For the case of Φ = 1.336, the [Na]maxtotal and [K]maxtotal were found to be 13.9 and 6.67 ppm during the char phase from burning coal particles, respectively, and 21.1 and 39.7 ppm, respectively, from burning wood particles. The concentration of alkali species was higher during the ash phase. The limit of detection (LOD) of sodium and potassium with LIBS in the present arrangement was estimated to be 29 and 72 ppb, respectively.
Determination of Volume Fractions in Multicomponent Mixtures Using Ultrasound Frequency Analysis
Authors: Dion Jonathan R. , Burns David H.
Published: May 2011

Controlling the composition of mixtures is critical for quality control in a wide variety of applications. There is a need for rapid, on-site measurements to optimize processes in real time. Ultrasound easily penetrates opaque samples and containers, yet currently provides minimal chemical information. We have developed a general approach to determine the volume fraction of a liquid in mixtures with multiple components. Ultrasound waves propagating through a medium undergo distortion processes that are characteristic of the chemical bonding composition. The distortion of the waveform can be measured in the ultrasound frequency profile. An ultrasound pulse-through configuration with matching 5 MHz transducers was used to analyze mixtures of water, methanol, and ethanol. Multilinear regression analysis was used to determine the volume fraction of all components in a series of mixtures. Using this technique, volume fractions were determined simultaneously with correlation coefficients ( r2) greater than 0.98 in two-component mixtures. Determination of volume fractions in three-component mixtures ranging from 65–100% water also showed correlation coefficients of 0.91 for methanol and 0.94 for ethanol. This technique is attractive for process monitoring due to the short measurement time and the simple methodology that excludes sample pretreatment.
An Advanced Digital Filter for One-Dimensional Spectroscopic Data: Minimizing Distortion in Band Shapes and Band Intensities
Authors: Guo Liangfeng , Garland Marc
Published: May 2011

A wide variety of digital filters exist for processing one-dimensional (1D) signals; however, the application of some filters results in pronounced systematic distortions in band shapes and band intensities. In the present contribution, filtering is achieved by optimization in which a general objective function is constructed that possesses a number of desirable qualities, such as (1) smoothness of the resulting spectrum as well as (2) statistical constraints on the residual. Since the residual is explicitly used in the optimization, one can control systematic distortions and therefore avoid over-filtering. In tests using a variety of synthetic as well as real 1D spectroscopic data, the filter adequately preserves both band shapes and band intensities. In addition, the filter appears to accommodate homoscedastic, heteroscedastic, and frequency-dependent noise. Examples of its application and usefulness to powder X-ray diffraction (PXRD), Raman, and Fourier transform infrared (FT-IR) emission data are provided. Tests with synthetic data indicate that considerable noise reduction can be achieved in many applications. Finally, an iterative form of the filter is presented. This iterative form further minimizes distortions in band shapes and band intensities when very high levels of denoising are desired. The present filtering approach is an alternative to existing filters, particular when the quality of the residual is important to the user.
Synthesis and Characterization of Gold Nanoparticles Coated with Ultrathin and Chemically Inert Dielectric Shells for SHINERS Applications
Authors: Li Jian-Feng , Li Song-Bo , Anema Jason R. , Yang Zhi-Lin , Huang Yi-Fan , Ding Yong , Wu Yuan-Fei , Zhou Xiao-Shun , Wu De-Yin , Ren Bin , Wang Zhong-Lin , Tian Zhong-Qun
Published: May 2011

We very recently reported a new spectroscopic application for expanding the versatility of surface Raman called “shell-isolated nanoparticle-enhanced Raman spectroscopy” or “SHINERS”. The most important and most difficult part of the SHINERS experiment is the effective transfer of the strong electromagnetic field from a gold core through the isolating silica or alumina shell to the probed surface. For this it is essential that the chemically inert dielectric shell be ultrathin (2–5 nm) yet pinhole-free. Herein we describe experimental and theoretical aspects of our SHINERS method in more detail. We provide a protocol for the synthesis and characterization of optimized shell-isolated nanoparticles (SHINs), and we examine the advantages of SHINERS nanoparticles over bare gold nanoparticles. We also present high-quality Raman spectra obtained from gold and platinum single-crystal surfaces in an electrochemical environment by our SHINERS technique. SHINERS is a simple and cost-effective approach that expands the flexibility of surface-enhanced Raman scattering (SERS) for an unprecedented diversity of applications in materials and surface sciences.
Time Dependence of Cellular Chemical Changes Induced in Prostate PC-3 Cancer Cells by Two Structurally Related Cardenolides Monitored by Fourier Transform Infrared (FT-IR) Spectroscopy
Authors: Gasper Régis , Mijatovic Tatjana , Kiss Robert , Goormaghtigh Erik
Published: May 2011

Human PC-3 prostate cancer cells were incubated in the presence of two cardenolides, i.e., ouabain and 19-hydroxy-2“-oxovoruscharin. Their effects were monitored by infrared spectroscopy of the cells after different exposure times to the cardenolides. Analysis of changes in absorbance intensities indicated that, for both compounds, the absorbance at one wavenumber with a minor contribution of a second wavenumber is sufficient to build a linear model accurate enough to assign more than 97% of the spectra to their correct time slot. Student t-tests and two-dimensional correlation analysis (2D-COS) indicated that both drugs have very similar effects on PC-3 cells. However, asynchronous 2D maps revealed significant differences and allowed the sequence of the spectral changes to be determined: 1395 → 1695 cm−1 for ouabain, and 1400 → 1655 → 1100 → 1250 → 1020 cm−1” for 19-hydroxy-2“-oxovoruscharin. 2D correlation map subtraction allowed the identification of very specific differences in the impact of both compounds on PC-3 cells, in particular the ability of 19-hydroxy-2”-oxovoruscharin to affect nucleic acid of PC-3 cells.
Self-Aggregation Processes of 1,6-Diphenyl-1,3,5-Hexatriene in Water/Ethanol Mixtures with High Water Percentages
Authors: Gracetto Augusto C. , Tessaro André L. , De Souza Vagner R. , Caetano Wilker , Pontes Rodrigo M. , Batistela Vagner R. , De Oliveira Hueder P. M. , Hioka Noboru
Published: May 2011

This work describes the behavior of 1,6-diphenyl-1,3,5-hexatriene (DPH) in ethanol/water mixtures. The dependence of DPH photophysical properties (absorption and fluorescence emission) on the water percentage in ethanol indicates that DPH undergoes self-aggregation processes in solvent conditions above a critical water content. Evidence such as an additional absorption band, Beer's law deviation, kinetic behavior, and other experimental results obtained from temperature variation and surfactant addition demonstrated the presence of several types of DPH aggregates. Resonance light scattering measurements proved that the aggregate grew in water-rich media by a self-catalyzed process.
Comparison between Infrared and Raman Spectroscopic Analysis of Maturing Rabbit Cortical Bone
Authors: Turunen Mikael J. , Saarakkala Simo , Rieppo Lassi , Helminen Heikki J. , Jurvelin Jukka S. , Isaksson Hanna
Published: May 2011

The molecular composition of the organic and inorganic matrices of bone undergoes alterations during maturation. The aim of this study was to compare Fourier transform infrared (FT-IR) and near-infrared (NIR) Raman microspectroscopy techniques for characterization of the composition of growing and developing bone from young to skeletally mature rabbits. Moreover, the specificity and differences of the techniques for determining bone composition were clarified. The humeri of female New Zealand White rabbits, with age range from young to skeletally mature animals (four age groups, n = 7 per group), were studied. Spectral peak areas, intensities, and ratios related to organic and inorganic matrices of bone were analyzed and compared between the age groups and between FT-IR and Raman microspectroscopic techniques. Specifically, the degree of mineralization, type-B carbonate substitution, crystallinity of hydroxyapatite (HA), mineral content, and collagen maturity were examined. Significant changes during maturation were observed in various compositional parameters with one or both techniques. Overall, the compositional parameters calculated from the Raman spectra correlated with analogous parameters calculated from the IR spectra. Collagen cross-linking (XLR), as determined through peak fitting and directly from the IR spectra, were highly correlated. The mineral/matrix ratio in the Raman spectra was evaluated with multiple different peaks representing the organic matrix. The results showed high correlation with each other. After comparison with the bone mineral density (BMD) values from micro-computed tomography (micro-CT) imaging measurements and crystal size from XRD measurements, it is suggested that Raman microspectroscopy is more sensitive than FT-IR microspectroscopy for the inorganic matrix of the bone. In the literature, similar spectroscopic parameters obtained with FT-IR and NIR Raman microspectroscopic techniques are often compared. According to the present results, however, caution is required when performing this kind of comparison.
In-situ Monitoring of the Structure of a Goethite-Based Catalyst during Methane Oxidation by X-Ray Absorption Near-Edge Structure (XANES) Spectroscopy Assisted by Chemometric Methods
Authors: Nunes Cleiton A. , Resende Eliane C. , Guimarães Iara R. , Anastácio Alexandre S. , Guerreiro Mário C.
Published: May 2011

A goethite-based catalyst was evaluated using in-situ X-ray absorption near-edge structure (XANES) spectroscopy during methane oxidation under increasing reaction temperature. Determination of rank by median absolute deviation (DRMAD), evolving factor analysis (EFA), and multivariate curve resolution (MCR) were used to detect the species present in the catalyst during the reaction and determine their concentration profiles and their pure spectra. The reactants and reaction products were monitored on-line by mass spectrometer. The goethite-based catalyst was active for methane oxidation, with CO2 and H2O as the main products. DRMAD and EFA were useful to determine the number of chemical species present in the catalyst structure during reactions. The catalyst presented phase transition during the reaction from goethite to maghemite according to XANES spectra determined by MCR. On the other hand, it was verified that the catalyst presented phase transition from goethite to wüstite in the process in the absence of the oxidant (O2).
Semi-Automated Detection of Trace Explosives in Fingerprints on Strongly Interfering Surfaces with Raman Chemical Imaging
Authors: Tripathi Ashish , Emmons Erik D. , Wilcox Phillip G. , Guicheteau Jason A. , Emge Darren K. , Christesen Steven D. , Fountain Augustus W.
Published: May 2011

We have previously demonstrated the use of wide-field Raman chemical imaging (RCI) to detect and identify the presence of trace explosives in contaminated fingerprints. In this current work we demonstrate the detection of trace explosives in contaminated fingerprints on strongly Raman scattering surfaces such as plastics and painted metals using an automated background subtraction routine. We demonstrate the use of partial least squares subtraction to minimize the interfering surface spectral signatures, allowing the detection and identification of explosive materials in the corrected Raman images. The resulting analyses are then visually superimposed on the corresponding bright field images to physically locate traces of explosives. Additionally, we attempt to address the question of whether a complete RCI of a fingerprint is required for trace explosive detection or whether a simple non-imaging Raman spectrum is sufficient. This investigation further demonstrates the ability to nondestructively identify explosives on fingerprints present on commonly found surfaces such that the fingerprint remains intact for further biometric analysis.
Design and Optimization of the Calibration Procedure for a Miniaturized Fourier Transform Spectrometer
Authors: Saggin Bortolino , Scaccabarozzi Diego
Published: May 2011

This paper presents a Fourier transform infrared (FT-IR) spectrometer calibration procedure based on an unusual source made from a spectrally selective surface. An alternative solution to the usual calibrators has been developed to cope with the tight mass budget of an instrument devoted to Mars surface exploration. The designed system has proved effective, in terms of achievable radiometric accuracy, despite the drawbacks due to the significant reflectivity of the sources. The proposed procedure is a standard “two-source” approach in which both cold and hot sources are thermally controlled surfaces, similar to an optical solar reflector, associated to a filament lamp. Such a system allows the required signal to be achieved in the 2–25 μm instrument wavelength range. Source optimization was performed using, as a cost function, the computed radiometric uncertainty, while the required absolute accuracy of the instrument was imposed as the optimization constraint.
The Detection of Palladium Particles in Proton Exchange Membrane Fuel-Cell Water by Laser-Induced Breakdown Spectroscopy (LIBS)
Authors: Snyder Stuart C. , Wickun William G. , Mode Jeremy M. , Gurney Brian D. , Michels Fred G.
Published: May 2011

Laser-induced breakdown spectroscopy (LIBS) using conditional data analysis was applied to aqueous suspensions of palladium particles in the reformate water of palladium-based proton exchange membrane fuel cells. A significant amount of palladium was found in the water, indicating degradation of the fuel-cell cathode catalytic layers. The palladium particle-size detection limit was found to be about 400 nm. Calibration procedures to quantify the palladium concentration are discussed.
Back-Surface Gold Mirrors for Vibrationally Resonant Sum-Frequency (VR-SFG) Spectroscopy Using 3-Mercaptopropyltrimethoxysilane as an Adhesion Promoter
Authors: Quast Arthur D. , Zhang Feng , Linford Matthew R. , Patterson James E.
Published: May 2011

Back-surface mirrors are needed as reference materials for vibrationally resonant sum-frequency generation (VR-SFG) probing of liquid-solid interfaces. Conventional noble metal mirrors are not suitable for back-surface applications due to the presence of a metal adhesion layer (chromium or titanium) between the window substrate and the reflective metal surface. Using vapor deposited 3-mercaptopropyltrimethoxysilane (MPTMS) as a bi-functional adhesion promoter, gold mirrors were fabricated on fused silica substrates. These mirrors exhibit excellent gold adhesion as determined by the Scotch® tape test. They also produce minimal spectroscopic interference in the C–H stretching region (2800–3000 cm−1), as characterized by VR-SFG. These mirrors are thus robust and can be used as back-surface mirrors for a variety of applications, including reference mirrors for VR-SFG.
Advanced Spectral Imaging for Noninvasive Microanalysis of Cultural Heritage Materials: Review of Application to Documents in the U.S. Library of Congress
Authors: France Fenella G.
Published: May 2011

Hyperspectral imaging was originally developed for remote sensing and astronomical applications, but adaptations of this technology have been of great benefit to the preservation of cultural heritage. Developments in noninvasive analytical techniques have advanced the preservation of cultural heritage materials by enabling the identification and analysis of a range of materials, utilizing their unique spectral response to nondestructively determine chemical composition, and determining states of deterioration and change due to environmental conditions. When used as a tool for noninvasive characterization of cultural heritage, these spectral imaging systems allow the collection of chemical identification information about materials without sampling, which is a critical factor for cultural heritage materials. The United States Library of Congress has been developing the application of hyperspectral imaging to the preservation and analysis of cultural heritage materials as a powerful noncontact technique. It allows noninvasive characterization of materials, by identifying and characterizing colorants, inks, and substrates with narrow-band illumination to protect the object while also monitoring deterioration or changes due to exhibit and other environmental conditions. Contiguous illumination from the ultraviolet, visible, and infrared spectral regions allows the capture of lost, obscured, and deteriorated information. The resulting image cube allows greater capabilities for mapping and coordinating a range of complementary chemical and spectral analyses. The capabilities of this technique are illustrated by a review of results from analysis of the Waldseemüller World Map, the L'Enfant plan for Washington, D.C., and the first draft of the U.S. Declaration of Independence.
FRIENDS Parent Project: Effectiveness of Parent Training in Reducing Parent Anxiety in a Universal Prevention Program for Anxiety Symptoms in School Children
Authors: Fukushima-Flores Marnie , Miller Lynn
Published: May 2011

Anxiety is the most pervasive childhood mental health disorder today. This study examined the parent component of a school-based universal prevention and early intervention program. Participating parents (N= 122) completed four measures on anxiety, the Anxiety Sensitivity Index, the Center for Epidemiological Studies-Depression, the Penn State Worry Questionnaire, and the Screen for Child Anxiety Related Emotional Disorders, before and after the parent program. The effectiveness of the program was investigated by analysing mean scores of the parent self-reported anxiety symptoms and parent reports of child anxiety symptoms. The main analyses conducted were 2 × 2 between-within ANOVAs for each measure. The hypothesis that parents who participated in the program (n= 20) would report reduced anxiety symptoms for themselves and for their children when compared to parents who did not attend (n= 120) was not confirmed. The parent's satisfaction level with the program was also studied, with high acceptability ratings providing strong social validity for this program. Implications of the findings, strengths, limitations and suggestions for further research are discussed.
Lifetime Exposure to Adverse Events and Reinforcement Sensitivity in Obsessive–Compulsive Prone Individuals
Authors: Ceschi Grazia , Hearn Melissa , Billieux Joël , Linden Martial Van der
Published: May 2011

A diathesis-stress perspective of obsessive–compulsive symptoms (OCS) predicts that exposure to adverse events and personality dispositions jointly influence OCS. Gray and McNaughton's (2000) model of personality posits that, faced with challenging circumstances, individuals with a high sensitivity to punishment (SP) will be more prone to OCS because they cannot avoid the downward spiral into anxiety. The current study investigates OCS severity in relation to lifetime exposure to adverse events (AE), SP, and sensitivity to reward (SR) in 122 nonclinical adults. The results indicate that OCS severity is predicted by AE, SP and SR. Interestingly, the impact of adverse experiences is moderated by SR and not SP. These findings suggest that: (1) exposure to adverse events and SP are independent OCS risk factors, and (2) exposure to adverse events is more critical for reward dependent people. This is discussed in light of responsibility and ‘not just right experiences’ in OCS, along with the role of impulsivity in the obsessive-compulsive disorder spectrum.
Skills Training and Self-Esteem: Educational and Clinical Perspectives on Giving Feedback to Clinical Trainees
Authors: Green Heather J.
Published: May 2011

Some education scholars view student self-esteem as very important to the learning process. However, in relation to clinical supervision, it has also been noted that supervisor overconcern about student self-esteem can lead to avoidance of negative feedback or giving feedback that is too vague to be useful. This article examines the role of self-esteem in relation to assessment and feedback practices in clinical training. A review of educational and clinical literature on self-esteem was undertaken, and suggested that differentiation between self-esteem and self-efficacy provides a more useful framework for supervisors than focus on self-esteem alone. Feedback about specific skills, and developing better coherence between supervisor and student assessment of the student's skills, are important components of clinical training. Suggestions are provided for guiding innovation in supervision and clinical training.
Self-Monitoring in the Treatment of Overweight Adolescents
Authors: Sandilands Mary , Brennan Leah , Walkley Jeff , Fraser Steve F. , Greenway Kate
Published: May 2011

The aim of this study was to explore the relationship between the quantity and quality of self-monitoring and per cent fat loss in overweight and obese adolescents participating in a weight-loss intervention. Participants were 55 (33F) over-weight and obese adolescents taking part in a 20-week cognitive–behavioural intervention aimed at improving eating and physical activity behaviours. Food and physical activity self-monitoring from the first 9 weeks of the intervention was coded using 24 components assessing the quantity (20) and quality (4) of self-monitoring. Those who completed treatment (n= 42) were split into groups: Losers (n= 30) and Gainers (n= 12) of per cent body fat as measured by DXA. Group analyses showed that Losers and Gainers could be differentiated by both quantitative and qualitative measures of self-monitoring. The strongest associations were with the classifications of food and drink items into food groups. The number of days monitored and the average number of items recorded did not differentiate the groups. Quantity and quality measures of self-monitoring completed early in treatment could also differentiate those who completed treatment and those who did not complete treatment (n= 13), and the strongest associations were with the amounts of food and drink items recorded, an association not found with treatment outcome. The results indicate that both quantity and quality of self-monitoring may be important predictors of both treatment completion and outcome. Based on these findings a framework of self-monitoring requirements is offered to reduce homework burden while maximising treatment efficacy.
The Influence of Informant Characteristics on the Reliability of Family History Interviews
Authors: Verweij Kim H. W. , Derks Eske M. , Hendriks Eva J. E. , Cahn Wiepke
Published: May 2011

Family history interviews are widely used in psychiatric research, as well as in genetic and twin studies, and provide a way to collect family history information quickly and economically. To obtain a valid assessment of family history, it is important to investigate which family member will be able to provide accurate information. Previous research shows that the validity of family history reporting can be influenced by characteristics of the informant, such as age, gender and personal history of psychiatric disorder. The aim of this study was to investigate the role of a subject's position in a pedigree on the validity of data collection. Family history data on diabetes and psychiatric disorders were collected in three generations of 33 families by interviewing both an index subject (3rd generation) and his or her mother (2nd generation). Mothers were shown to report higher rates of diabetes and psychiatric disorder in the family compared to the index subjects. There was no significant difference in the disease rate reported by male and female index subject. Mothers who experienced a depressive episode indicated significantly more family members as having a psychiatric disorder than mothers who never experienced such an episode. This could be explained by the presence of informant bias, but may also result from the fact that depression is a heritable disorder and is therefore actually more prevalent in these families. Our findings suggest that family interview data should be collected by interviewing subjects who have a central position in the pedigree and can therefore provide information on his/her own generation, the previous and the next. In addition, psychiatric status of the informant should be carefully addressed.
Statistical Approach to Prenatal Zygosity Assessment Following a Decade of Molecular Aneuploidy Screening
Authors: Pires Sílvia , Nogueira António J. A. , Pinho Odília , Delgado Tiago , Sousa Mário , Santos Rosário , Jorge Paula
Published: May 2011

In twin pregnancy studies, molecular genetic techniques have rarely been used to determine zygosity, despite their known precision and accuracy. The present work aimed to assess the power of discrimination in zygosity assessment, using a set of microsatellite markers that were routinely used for aneuploidy screening by multiplex-PCR in a prenatal context. Rapid aneuploidy screening using a group of 20 microsatellite markers (STRs) located on chromosomes 13, 18, 21 and X has been performed in our lab for over 10 years, with a total of approximately 1,500 samples studied to date. A retrospective analysis of the 257 prenatal samples from multiple pregnancies was carried out. A subset of 14 cases presenting theoretical monozygosity were re-evaluated by the use of biostatistics tools accessed via the ZygProb website. Further monozygosity determination relative to dizygosity was calculated, given an estimated overall error value of 0.093%. The results show that monozygosity had been correctly determined in all our previously studied twins. This work demonstrates that accurate zygosity assessment can be achieved with the same STRs applied in aneuploidy screening with a high power of discrimination and a matching probability of over 99.999999%.
SNP Sets and Reading Ability: Testing Confirmation of a 10-SNP Set in a Population Sample
Authors: Luciano Michelle , Montgomery Grant W. , Martin Nicholas G. , Wright Margaret J. , Bates Timothy C.
Published: May 2011

A set of 10 SNPs associated with reading ability in 7-year-olds was reported based on initial pooled analyses of 100K SNP chip data, with follow-up testing stages using pooling and individual testing. Here we examine this association in an adolescent population sample of Australian twins and siblings (N= 1177) aged 12 to 25 years. One (rs1842129) of the 10 SNPs approached significance (P= .05) but no support was found for the remaining 9 SNPs or the SNP set itself. Results indicate that these SNPs are not associated with reading ability in an Australian population. The results are interpreted as supporting use of much larger SNP sets in common disorders where effects are small.
A Behavior Genetic Study of the Connection Between Social Values and Personality
Authors: Schermer Julie Aitken , Vernon Philip A. , Maio Gregory R. , Jang Kerry L.
Published: May 2011

The present research examined the extent to which relations between social values and personality are due to shared genetic or environmental factors. Using the Rokeach (1973) Value Survey and a scoring key from Schwartz and Bilsky (1990), seven value scores (enjoyment, achievement, self-direction, maturity, prosocial, security, and restrictive conformity) were derived in a sample of twins. As expected, all of the value scales were found to have a significant genetic component, with values ranging from 36% for enjoyment to 63% for prosocial, and there were numerous significant phenotypic correlations found between the value scales and personality scores. Most important, bivariate genetic analyses revealed that some of these phenotypic correlations could be attributed to common genetic or environmental factors.
An Epidemiological Survey of Post-Coital Psychological Symptoms in a UK Population Sample of Female Twins
Authors: Burri Andrea V. , Spector Tim D.
Published: May 2011

Postcoital psychological symptoms (PPS) is a virtually unexplored phenomenon in the female population even though women frequently complain about irritability and motiveless crying after intercourse and/or orgasm. The aim of this study was to explore the epidemiology and genetic influences of PPS in a UK population sample of women. 1,489 unselected female twins aged 18–85 completed questions on recent and persistent PPS and potential risk factors. Standard methods of quantitative genetic analysis were used to model latent genetic and environmental factors influencing variation in PPS. For identification of potential risk factors, regression analyses were conducted. Phenotypic variation in PPS was explored using a genetic variance component analysis (VCA) approach. We found 3.7% of women reported suffering from recent PPS and 7.7% from persistent PPS. Relationship satisfaction and experience of abuse were found to be independently associated with recent (OR 4.5, 95% CI 4.13–4.87 and OR 1.3, 95% CI 1.02–1.34, respectively) and persistent PPS (OR 2.53, 95% CI 2.17–2.81 and OR 1.16, 95% CI 1.09–1.26, respectively). VCA revealed that phenotypic variance was best explained by an additive genetic (AE) model, ascribing 28% (for recent PPS) and 26% (for persistent PPS) of phenotypic variance to additive genetic effects, with the rest being a result of individual experiences and random measurement error. To our knowledge, this is the first and largest study investigating the epidemiology of PPS. It seems that the most important targets for intervention and prevention occur outside of the family, such as relationship quality and satisfaction, and history of abuse.
Subjective Wellbeing and Longevity: A Co-Twin Control Study
Authors: Sadler Michael E. , Miller Christopher J. , Christensen Kaare , McGue Matt
Published: May 2011

Mental health is increasingly defined not only by the absence of illness but by the presence of subjective well-being (SWB). Previous cohort studies have consistently shown that indicators of SWB predict favorable life outcomes, including better mental and somatic health, and longevity. The favorable effects associated with SWB have prompted new research aimed at raising happiness and wellbeing through individual interventions and public health initiatives. Standard observational studies of individual-level associations, however, are subject to potential confounding of exposure and outcome by shared genes and environment. The present study explored the association between SWB and increased longevity, using twin pair analyses to determine whether the association is consistent with causality or is due to genetic or environmental confounding. The study sample of 3,966 twins aged 70 or older, followed for a median time period of 9 years, was drawn from the population-based Longitudinal Study of Aging Danish Twins (LSADT). The association between SWB, operationalized as affect and life satisfaction, and all-cause mortality risk was examined using between-individual and within-pair survival analyses. As expected, at the individual level, SWB predicted increased longevity. Exposure effects were also present in unadjusted and adjusted within-pair analyses of 400 dizygotic (DZ) pairs and 274 monozygotic (MZ) pairs, indicating that SWB is associated with increased longevity independent of familial factors of genes and shared environment.
Genome-Wide Linkage Analysis of Hemodynamic Parameters Under Mental and Physical Stress in Extended Omani Arab Pedigrees: The Oman Family Study
Authors: Hassan Mohammed O. , Jaju Deepali , Voruganti V. Saroja , Bayoumi Riad A. , Albarwani Sulayma , Al-Yahyaee Saeed , Aslani Afshin , Snieder Harold , Lopez-Alvarenga Juan C. , Al-Anqoudi Zahir M. , Alizadeh Behrooz Z. , Comuzzie Anthony G.
Published: May 2011

Background:We performed a genome-wide scan in a homogeneous Arab population to identify genomic regions linked to blood pressure (BP) and its intermediate phenotypes during mental and physical stress tests.Methods:The Oman Family Study subjects (N= 1277) were recruited from five extended families of ~10 generations. Hemodynamic phenotypes were computed from beat-to-beat BP, electrocardiography and impedance cardiography. Multi-point linkage was performed for resting, mental (word conflict test, WCT) and cold pressor (CPT) stress and their reactivity scores (s), using variance components decomposition-based methods implemented in SOLAR.Results:Genome-wide scans for BP phenotypes identified quantitative trait loci (QTLs) with significant evidence of linkage on chromosomes 1 and 12 for WCT-linked cardiac output (LOD = 3.1) and systolic BP (LOD = 3.5). Evidence for suggestive linkage for WCT was found on chromosomes 3, 17 and 1 for heart rate (LOD = 2.3), DBP (LOD = 2.4) and left ventricular ejection time (LVET), respectively. For △WCT, suggestive QTLs were detected for CO on chr11 (LOD = 2.5), LVET on chr3 (LOD = 2.0) and EDI on chr9 (LOD = 2.1). For CPT, suggestive QTLs for HR and LVET shared the same region on chr22 (LOD 2.3 and 2.8, respectively) and on chr9 (LOD = 2.3) for SBP, chr7 (LOD = 2.4) for SV and chr19 (LOD = 2.6) for CO. For △CPT, CO and TPR top signals were detected on chr15 and 10 (LOD; 2.40, 2.08) respectively. Conclusion: Mental stress revealed the largest number of significant and suggestive loci for normal BP reported to date. The study of BP and its intermediate phenotypes under mental and physical stress may help reveal the genes involved in the pathogenesis of essential hypertension.
Twin-Singleton Differences in Neonatal Brain Structure
Authors: Knickmeyer Rebecca C. , Kang Chaeryon , Woolson Sandra , Smith J. Keith , Hamer Robert M. , Lin Weili , Gerig Guido , Styner Martin , Gilmore John H.
Published: May 2011

Twin studies suggest that global and regional brain volumes are highly heritable. However, estimates of heritability vary across development. Given that all twin studies are open to the potential criticism of non-generalizability due to differences in intrauterine environment between twins and singletons, these age effects may reflect the influence of perinatal environmental factors, which are unique to twins and which may be especially evident early in life. To address this question, we compared brain volumes and the relationship of brain volumes to gestational age in 136 singletons (67 male, 69 female) and 154 twins (75 male, 79 female; 82 DZ, 72 MZ) who had received high resolution MRI scans of the brain in the first month of life. Intracranial volume, total white matter, and ventricle volumes did not differ between twins and singletons. However, cerebrospinal fluid and frontal white matter volume was greater in twins compared to singletons. While gray matter volumes at MRI did not differ between groups, the slope of the relationship between total and cortical gray matter and gestational age at the MRI scan was steeper in MZ twins compared to DZ twins. Post-hoc analyses suggested that gray matter development is delayed in MZ twins in utero and that they experience ‘catch-up’ growth in the first month of life. These differences should be taken into account when interpreting and designing studies in the early postnatal period.
Resemblance of Tongue Anatomy in Twins
Authors: Spielman Andrew I. , Brand Joseph G. , Buischi Yvonne , Bretz Walter A.
Published: May 2011

This study compared the anatomical features of the tongue in nine pairs of twins — six monozygotic and three dizygotic. The aim of the project was to determine if tongues, like any other anatomical structure, could be used to reliably predict relatedness given that tongue shape, presentation and surface can be influenced by environment. Using the method of forced choice, 30 subjects were asked to match the photographs of tongues from twins. Our data indicate that, based on visual assessment, monozygotic twins have highly similar tongues (60% matches); similarly, dizygotic twins were matched 31% of the time, which is a higher probability than would be expected from random selection. This study should help identify baseline and control data in future behavioral studies of taste, which has a genetic basis.
Expectant Management in Twin Pregnancies With Discordant Structural Fetal Anomalies
Authors: Linskens Ingeborg H. , Elburg Ruurd M. van , Oepkes Dick , Vugt John M. G. van , Haak Monique C.
Published: May 2011

Objective:Routine obstetric ultrasound increasingly leads to the detection of structural fetal anomalies. In twin pregnancies with one anomalous twin, counseling on management strategies is complicated. Patients and methods: Twin pregnancies (n= 212) were referred to a tertiary center between January 2007 and July 2009. In a retrospective analysis, twins discordant for a structural fetal anomaly were compared to twins without anomalies in the prenatal ultrasound. Outcome parameters were survival and gestational age at birth.Results:Anomalies were seen in at least one fetus of 30 twin pairs. The two pregnancies in which the anomalies were concordant were terminated. Selective feticide was performed in three cases of major but non-lethal anomalies in dichorionic twins. The remaining 25 cases were managed expectantly. In three of these cases, spontaneous fetal demise of the affected fetus was observed. In five cases with major (lethal) anomalies, the pregnant women and their partners opted for non-intervention comfort care after birth for the affected fetus. Median gestational age at delivery was 257 days for twins without structural anomalies and was 254 days (n= 22) for twins with one anomalous fetus. This was not significantly different (Mann Whitney U,p= .69). Again, no difference was found for median gestational age at delivery in normal vs. discordant anomalous dichorionic twins if subdivided for chorionicity (Mann Whitney U,p= .68).Conclusion:In this cohort we describe the request for expectant management by pregnant women and their partners of those twins discordant for major (lethal) anomalies. Expectant management was not associated with increased risk of premature delivery. Fetocide was only opted for in a small number of cases with severe but non-lethal anomalies in dichorionic twins.
Reunited Twins: Spouse Relations / Twin Research Reports / Timely Topics
Authors: Segal Nancy L.
Published: May 2011

The present article explores the social attraction that may evolve on the part of reared apart twins' spouses toward their brothers- and sisters-in-law, that is, their spouses' newly found co-twin. This topic was inspired by the fascinating story of monozygotic reared apart (MZA) twins who were reunited in Perth, Australia in 2008, at age 50. It is followed by brief reviews of twin research articles concerning divorce rates among mothers of multiples and X-chromosome inactivation in MZ female twin pairs. The final section presents informative human interest stories involving twins.
Disintegration and dissolution kinetics of wood chips in ionic liquids
Authors: Viell Jörn , Marquardt Wolfgang
Published: May 2011

Ionic liquids are able to dissolve polysaccharides and lignin, but there is only scarce knowledge about the dissolution of native wood. In the present paper, wood was dissolved by the ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIMAc). A quantitative balance of the dissolved compounds is presented and the investigations are complemented byin situmicroscopy of native wood in EMIMAc. The resulting dissolution kinetics in EMIMAc reveals distinct differences between spruce and beech. While particles of 0.1–0.5 mm of spruce dissolve slowly (up to 40% after 24 h), beech is dissolved more efficiently (75% after 24 h and 90% after 72 h). Wood chips of 10 mm length show similar dissolution kinetics and lignin yields of up to 10%. Microscopic studies reveal a disintegration of wood in EMIMAc into cells with large specific surface area, and differences in dissolution between spruce and beech were observed. These findings explain the size-independent dissolution of wood in EMIMAc and may open up new opportunities for the pretreatment of wood in ionic liquids.
Radical scavenging characteristics of condensed tannins from barks of various tree species compared with quebracho wood tannin
Authors: Makino Rei , Ohara Seiji , Hashida Koh
Published: May 2011

The object of this study was to elucidate the relationship between the chemical structure of purified condensed tannin polymers from tree species and their radical scavenging characteristics. By means of 13C-NMR spectrometry and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), four kinds of proanthocyanidins were identified: prorobinetinidins, profisetinidins, procyanidins, and prodelphinidins. The tannins were submitted to radical scavenging assays with DPPH and galvinoxyl radicals and from the time-course of the reactions was concluded: 1) Tannins with pyrogallol type B-ring scavenge radicals in the beginning faster than those with catechol type B-ring. 2) Tannins with catechol type B-ring needs more time to scavenge the same amount of radicals as those with pyrogallol type B-ring. 3) The IC50 values of tannins with catechol type B-ring decrease after longer reaction times with the galvinoxyl radical. 4) Radical scavenging with DPPH radical proceeds faster than that for the galvinoxyl radical.