bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fitting ACE structural equation models to case‐control family data
Authors: Javaras K. N. , Hudson J. I. , Laird N. M. 
Published: November 2009

AbstractInvestigators interested in whether a disease aggregates in families often collect case‐control family data, which consist of disease status and covariate information for members of families selected via case or control probands. Here, we focus on the use of case‐control family data to investigate the relative contributions to the disease of additive genetic effects (A), shared family environment (C), and unique environment (E). We describe an ACE model for binary family data; this structural equation model, which has been described previously, combines a general‐family extension of the classic ACE twin model with a (possibly covariate‐specific) liability‐threshold model for binary outcomes. We then introduce our contribution, a likelihood‐based approach to fitting the model to singly ascertained case‐control family data. The approach, which involves conditioning on the proband's disease status and also setting prevalence equal to a prespecified value that can be estimated from the data, makes it possible to obtain valid estimates of the A, C, and E variance components from case‐control (rather than only from population‐based) family data. In fact, simulation experiments suggest that our approach to fitting yields approximately unbiased estimates of the A, C, and E variance components, provided that certain commonly made assumptions hold. Further, when our approach is used to fit the ACE model to Austrian case‐control family data on depression, the resulting estimate of heritability is very similar to those from previous analyses of twin data. Genet. Epidemiol. 34: 238–245, 2010.   © 2009 Wiley‐Liss, Inc.
Comparing apples and oranges: equating the power of case‐control and quantitative trait association studies
Authors: Yang Jian , Wray Naomi R. , Visscher Peter M. 
Published: November 2009

AbstractGenome‐wide association studies have achieved unprecedented success in the identification of novel genes and pathways implicated in complex traits. Typically, studies for disease use a case‐control (CC) design and studies for quantitative traits (QT) are population based. The question that we address is what is the equivalence between CC and QT association studies in terms of detection power and sample size? We compare the binary and continuous traits by assuming a threshold model for disease and assuming that the effect size on disease liability has similar feature as on QT. We derive the approximate ratio of the non‐centrality parameter (NCP) between CC and QT association studies, which is determined by sample size, disease prevalence (K) and the proportion of cases (v) in the CC study. For disease with prevalence <0.1, CC association study with equal numbers of cases and controls (v=0.5) needs smaller sample size than QT association study to achieve equivalent power, e.g. a CC association study of schizophrenia (K=0.01) needs only ∼55% sample size required for association study of height. So a planned meta‐analysis for height on ∼120,000 individuals has power equivalent to a CC study on 33,100 schizophrenia cases and 33,100 controls, a size not yet achievable for this disease. With equal sample size, when v=K, the power of CC association study is much less than that of QT association study because of the information lost by transforming a quantitative continuous trait to a binary trait. Genet. Epidemiol. 34: 254–257, 2010.   © 2009 Wiley‐Liss, Inc.
Comparison of different irrigation methods based on the parametric evaluation approach in the plain West of Shush, Iran
Authors: Albaji Mohammad , Nasab Saeed Boroomand , Kashkoli Hydar Ali , Naseri Abdali 
Published: November 2009

AbstractThe main objective of this research was to compare the suitability of land for surface and drip irrigation methods according to a parametric evaluation system in the plains west of the city of Shush, in south‐west Iran. After analysing and evaluating soil properties, suitability maps were generated for both methods by means of remote sensing (RS) and a geographic information system (GIS). The results showed that 9031 ha (21.5%) of the studied area was highly suitable for surface irrigation methods, whereas 32 500 ha (77.5%) of the study area was highly suitable for drip irrigation methods. Also some land units covering an area of 2111 ha (5.0%) were not suitable to be used for surface irrigation systems. One land unit with an area of 724 ha (1.7%) was classified as not suitable for drip irrigation systems. Moreover, the results indicated that a larger amount of the land (30 100 ha – 71.8%) can be classified as more suitable for drip than surface irrigation. Ultimately, the application of a drip irrigation system was suggested as the best method to be applied to the study area. The main limiting factors in using surface irrigation methods in this area were sandy soil texture and slope; moreover, for drip irrigation methods, the main limiting factor was soil calcium carbonate. Copyright © 2009 John Wiley & Sons, Ltd.
Predicting water allocations and trading prices to assist water markets
Authors: Khan Shahbaz , Dassanayake Dharma , Mushtaq Shahbaz , Hanjra Munir A 
Published: November 2009

AbstractUncertain water allocations and water trading prices are a key constraint to efficient irrigated cropping and water trading decisions. This study shows that neural network models can reasonably forecast seasonal allocations and trading prices in water markets. These models can complement other forecasting techniques such as regression analysis and time series models as the former can better capture the non‐linearities in the water trading system. Using a 50% probability risk factor for water variability, the water allocation model showed minor estimation error; however, in one instance the model underestimated the water allocation by 21%. This may be due to exceptionally low initial water allocations and borrowing of water from future years which was outside the training data sets. Similarly, the water trading price forecast model showed modest estimation error of about 11% during 2004/05 probably due to drought. Overall the models have good water allocation and price forecasting accuracy, and the determinants of water trading prices identified by the neural network models are those expected of the econometric models/economic theory. Copyright © 2009 John Wiley & Sons, Ltd.
Dual role of parathyroid hormone in endothelial progenitor cells and marrow stromal mesenchymal stem cells
Authors: Di Bernardo Giovanni , Galderisi Umberto , Fiorito Carmela , Squillaro Tiziana , Cito Letizia , Cipollaro Marilena , Giordano Antonio , Napoli Claudio 
Published: November 2009

AbstractHematopoietic stem cells derive regulatory information also from parathyroid hormone (PTH). To explore the possibility that PTH may have a role in regulation of other stem cells residing in bone marrow, such as mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) we assessed the effect of this hormone on the in vitro behavior of MSCs and EPCs. We evidenced that MSCs were much more responsive to PTH than EPCs. PTH increased the proliferation rate of MSCs with a diminution of senescence and apoptosis. Taken together, our results may suggest a protective effect of PTH on MSCs that reduces stress phenomena and preserve genome integrity. At the opposite, PTH did not modify the fate of EPCs in culture. J. Cell. Physiol. 222: 474–480, 2010. © 2009 Wiley‐Liss, Inc.
Paclitaxel and beta‐lapachone synergistically induce apoptosis in human retinoblastoma Y79 cells by downregulating the levels of phospho‐Akt
Authors: D'Anneo Antonella , Augello Giuseppa , Santulli Andrea , Giuliano Michela , di Fiore Riccardo , Messina Concetta , Tesoriere Giovanni , Vento Renza 
Published: November 2009

AbstractPaclitaxel (PTX) and beta‐lapachone (LPC) are naturally occurring compounds that have shown a large spectrum of anticancer activity. In this article we show for the first time that PTX/LPC combination induces potent synergistic apoptotic effects in human retinoblastoma Y79 cells. Combination of suboptimal doses of PTX (0.3 nM) and LPC (1.5 µM) caused biochemical and morphological signs of apoptosis at 48 h of treatment. These effects were accompanied by potent lowering in inhibitor of apoptosis proteins and by activation of Bid and caspases 3 and 6 with lamin B and PARP breakdown. PTX/LPC combination acted by favoring p53 stabilization through a lowering in p‐Akt levels and in ps166‐MDM2, the phosphorylated‐MDM2 form that enters the nucleus and induces p53 export and degradation. Treatment with wortmannin or transfection with a dominant negative form of Akt anticipated at 24 h the effects induced by PTX/LPC, suggesting a protective role against apoptosis played by Akt in Y79 cells. In line with these results, we demonstrated that Y79 cells contain constitutively active Akt, which forms a cytosolic complex with p53 and MDM2 driving p53 degradation. PTX/LPC treatment induced a weakness of Akt–MDM2–p53 complex and increased nuclear p53 levels. Our results suggest that phospho‐Akt lowering is at the root of the apoptotic action exerted by PTX/LPC combination and provide strong validation for a treatment approach that targets survival signals represented by phospho‐Akt and inhibitor of apoptosis proteins. J. Cell. Physiol. 222: 433–443, 2010. © 2009 Wiley‐Liss, Inc.
Altered lumbar spine structure, biochemistry, and biomechanical properties in a canine model of mucopolysaccharidosis type VII
Authors: Smith Lachlan J. , Martin John T. , Szczesny Spencer E. , Ponder Katherine P. , Haskins Mark E. , Elliott Dawn M. 
Published: November 2009

AbstractMucopolysaccharidosis VII (MPS VII) is a lysosomal storage disorder characterized by a deficiency in β‐glucuronidase activity, leading to systemic accumulation of poorly degraded glycosaminoglycans (GAG). Along with other morbidities, MPS VII is associated with pediatric spinal deformity. The objective of this study was to examine potential associations between abnormal lumbar spine matrix structure and composition in MPS VII, and spine segment and tissue‐level mechanical properties, using a naturally occurring canine model with a similar clinical phenotype to the human form of the disorder. Segments from juvenile MPS VII and unaffected dogs were allocated to: radiography, gross morphology, histology, biochemistry, and mechanical testing. MPS VII spines had radiolucent lesions in the vertebral body epiphyses. Histologically, this corresponded to a GAG‐rich cartilaginous region in place of bone and elevated GAG staining was seen in the annulus fibrosus. Biochemically, MPS VII samples had elevated GAG in the outer annulus fibrosus and epiphyses, low calcium in the epiphyses, and high water content in all regions except the nucleus pulposus. MPS VII spine segments had higher range of motion and lower stiffness than controls. Endplate indentation stiffness and failure loads were significantly lower in MPS VII samples, while annulus fibrosus tensile mechanical properties were normal. Vertebral body lesions in MPS VII spines suggest a failure to convert cartilage to bone during development. Low stiffness in these regions likely contributes to mechanical weakness in motion segments and is a potential factor in the progression of spinal deformity. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:616–622, 2010
Comparative study of carpal tunnel compliance in the human, dog, rabbit, and rat
Authors: Tung Wen‐Lin , Zhao Chunfeng , Yoshii Yuichi , Su Fong‐Chin , An Kin‐Nan , Amadio Peter C. 
Published: November 2009

AbstractThe purpose of this study was to measure the compliance of the carpal tunnel in candidate animal models of carpal tunnel syndrome (CTS), by measuring the resistance when passing a tapered metal rod through the carpal tunnel. Forepaws from 10 dogs, 10 rabbits, and 10 rats with intact carpal tunnels, and 10 fresh frozen human wrist cadavers were used. The slopes of the linear part of the force‐displacement curve (a measure of stiffness), normal force, and increasing area ratio (InAR) were significantly different among the four species (p < 0.05). Post hoc analysis indicated that the mean slopes for the human carpal tunnel were the largest, indicating the least compliance, whereas those of the rat were the least (p < 0.05). The features of the compliance for the dog carpal tunnel were closest to the human. The development of animal models of CTS should consider the compliance of the carpal tunnel, as it will be more difficult to increase pressure in a more compliant tunnel. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:652–656, 2010
Vibrational spectroscopic study of Sr2ZnTeO6 double perovskites
Authors: Dias Anderson , Subodh Ganesanpotti , Sebastian Mailadil T. , Moreira Roberto L. 
Published: November 2009

AbstractSr2ZnTeO6 ceramics were prepared by the solid‐state route and their vibrational phonon modes were investigated using optical spectroscopic techniques, for the first time. X‐ray diffraction (XRD) and Raman and infrared spectroscopies were employed to investigate the structures of these perovskite materials and the results analysed together with group‐theoretical predictions. The number and behaviour of the first‐order modes observed in both spectroscopic techniques are in agreement with the calculations for a tetragonal I4/m space group. The complete set of the optical phonon modes was determined, and the intrinsic dielectric properties of the materials were evaluated, allowing us to discuss their potential application in microwave (MW) circuitry. Copyright © 2009 John Wiley & Sons, Ltd.
FT‐IR and FT‐Raman investigations of the chemosensing material para‐hexafluoroisopropanol aniline
Authors: Kong Lingtao , Wang Jin , Jia Yong , Guo Zheng , Liu Jinhuai 
Published: November 2009

AbstractAs an important chemosensing material involving hexafluoroisopropanol (HFIP) for detecting nerve agents, para‐HFIP aniline (p‐HFIPA) has been firstly synthesized through a new reaction approach and then characterized by nuclear magnetic resonance and mass spectrometry experiments. Fourier transform infrared absorption spectroscopy (FT‐IR) and FT‐Raman spectra of p‐HFIPA have been obtained in the regions of 4000–500 and 4000–200 cm−1, respectively. Detailed identifications of its fundamental vibrational bands have been given for the first time. Moreover, p‐HFIPA has been optimized and vibrational wavenumber analysis can be subsequently performed via density functional theory (DFT) approach in order to assist these identifications in the experimental FT‐IR and FT‐Raman spectra. The present experimental FT‐IR and FT‐Raman spectra of p‐HFIPA are in good agreement with theoretical FT‐IR and FT‐Raman spectra. Copyright © 2009 John Wiley & Sons, Ltd.
Angel finance: the other venture capital
Authors: Wong Andrew , Bhatia Mihir , Freeman Zachary 
Published: November 2009

Abstract

The procurement of capital is an important consideration for an entity transforming from an entrepreneurial idea to a revenue generating company.

Angel financing is one of the most common, but least studied methods, to finance new ventures.

The term “Angel Investor” generally refers to a high net‐worth individual who typically invests in small, private firms on his or her own account.

Using a unique dataset of firms financed by angels between 1994 and 2001, our research provides some insight into the role of angels in funding, monitoring and guiding their investments.

Although exposed to greater uncertainty by investing earlier in the life of a firm compared to venture capital investors, angel investors do not rely on traditional control mechanisms such as board control, staging, or contractual provisions to protect against expropriation.

Angels may use more informal methods of control such as investing in close geographic proximity and syndicating investments with other angels to mitigate risks.

The results of the study indicate that angels have a complementary role to venture capital in the financing of new ventures.

Copyright © 2009 John Wiley & Sons, Ltd.
Price setting and market structure: an empirical analysis of micro data in Slovakia
Authors: Coricelli Fabrizio , Horváth Roman 
Published: November 2009

AbstractMost empirical studies on price setting that use micro data focus on advanced industrial countries. In this paper we analyze the experience of an emerging economy, Slovakia, using a large micro‐level dataset that accounts for a substantial part of the consumer price index (about 5 million observations). We find that market structure is an important determinant of pricing behavior. The effect of market structure on persistence of inflation results from two conflicting forces. Increased competition may reduce persistence by increasing the frequency of price changes. On the contrary, higher competition may increase persistence through inertial behaviour induced by the strategic complementarity among price setters. In our case study, we find that the latter effects dominate. Indeed, the dispersion of prices is higher while persistence is lower in the non‐tradable sectors, suggesting that higher competition is not conducive to lower persistence. Furthermore, we find that the frequency of price changes depends negatively on the price dispersion and positively on the product‐specific inflation. These results seem consistent with predictions of Calvo's staggered price model. Copyright © 2009 John Wiley & Sons, Ltd.
Structural determination of prunusins A and B, new C‐alkylated flavonoids from Prunus domestica, by 1D and 2D NMR spectroscopy
Authors: Mahmood Azhar , Fatima Itrat , Kosar Shaheen , Ahmed Rehana , Malik Abdul 
Published: November 2009

AbstractPrunusins A (1) and B (2), the new C‐alkylated flavonoids, have been isolated from the seed kernels of Prunus domestica. Their structures were assigned from 1H and 13C nuclear magnetic resonating spectra, DEPT and by correlation spectroscopy, HMQC and HMBC experiments. 3, 5, 7, 4′‐Tetrahydroxyflavone (3) and 3, 5, 7‐trihydroxy‐8, 4′‐dimethoxyflavone (4) have also been reported from this species. Both compounds (1) and (2) showed significant antifungal activity against pathogenic fungus Trichophyton simmi. Copyright © 2009 John Wiley & Sons, Ltd.
T2 relaxation time abnormalities in bipolar disorder and schizophrenia
Authors: Öngür Dost , Prescot Andrew P. , Jensen J. Eric , Rouse Elizabeth D. , Cohen Bruce M. , Renshaw Perry F. , Olson David P. 
Published: November 2009

AbstractThere are substantial abnormalities in the number, density, and size of cortical neurons and glial cells in bipolar disorder and schizophrenia. Because molecule‐microenvironment interactions modulate metabolite signals characteristics, these cellular abnormalities may impact transverse (T2) relaxation times. We measured T2 relaxation times for three intracellular metabolites (N‐acetylaspartate + N‐acetylaspartylglutamate, creatine + phosphocreatine, and choline‐containing compounds) in the anterior cingulate cortex and parieto‐occipital cortex from 20 healthy subjects, 15 patients with bipolar disorder, and 15 patients with schizophrenia at 4 T. Spectra used in T2 quantification were collected from 8‐cc voxels with varying echo times (30 to 500 ms, in 10‐ms steps). Both bipolar disorder and schizophrenia groups had numerically shorter T2 relaxation times than the healthy subjects group in both regions; these differences reached statistical significance for creatine + phosphocreatine and choline‐containing compounds in bipolar disorder and for choline‐containing compounds in schizophrenia. Metabolite T2 relaxation time shortening is consistent with reduced cell volumes and altered macromolecule structures, and with prolonged water T2 relaxation times reported in bipolar disorder and schizophrenia. These findings suggest that metabolite concentrations reported in magnetic resonance spectroscopy studies of psychiatric conditions may be confounded by T2 relaxation and highlight the importance of measuring and correcting for this variable. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
A short‐breath‐hold technique for lung pO2 mapping with 3He MRI
Authors: Miller G. Wilson , Mugler John P. , Altes Talissa A. , Cai Jing , Mata Jaime F. , de Lange Eduard E. , Tobias William A. , Cates Gordon D. , Brookeman James R. 
Published: November 2009

AbstractA pulse‐sequence strategy was developed for generating regional maps of alveolar oxygen partial pressure (pO2) in a single 6‐sec breath hold, for use in human subjects with impaired lung function. Like previously described methods, pO2 values are obtained by measuring the oxygen‐induced T1 relaxation of inhaled hyperpolarized 3He. Unlike other methods, only two 3He images are acquired: one with reverse‐centric and the other with centric phase‐encoding order. This phase‐encoding arrangement minimizes the effects of regional flip‐angle variations, so that an accurate map of instantaneous pO2 can be calculated from two images acquired a few seconds apart. By combining this phase‐encoding strategy with variable flip angles, the vast majority of the hyperpolarized magnetization goes directly into the T1 measurement, minimizing noise in the resulting pO2 map. The short‐breath‐hold pulse sequence was tested in phantoms containing known O2 concentrations. The mean difference between measured and prepared pO2 values was 1 mm Hg. The method was also tested in four healthy volunteers and three lung‐transplant patients. Maps of healthy subjects were largely uniform, whereas focal regions of abnormal pO2 were observed in diseased subjects. Mean pO2 values varied with inhaled O2 concentration. Mean pO2 was consistent with normal steady‐state values in subjects who inhaled 3He diluted only with room air. Magn Reson Med 63:127–136, 2010. © 2009 Wiley‐Liss, Inc.
RF shimming for spectroscopic localization in the human brain at 7 T
Authors: Hetherington Hoby P. , Avdievich Nikolai I. , Kuznetsov Andrey M. , Pan Jullie W. 
Published: November 2009

AbstractSpectroscopic imaging of the human head at short echo times (≤15 ms) typically requires suppression of signals from extracerebral tissues. However, at 7 T, decreasing efficiency in B generation (hertz/watt) and increasing spectral bandwidth result in dramatic increases in power deposition and increased chemical shift registration artifacts for conventional gradient‐based in‐plane localization. In this work, we describe a novel method using radiofrequency shimming and an eight‐element transceiver array to generate a B field distribution that excites a ring about the periphery of the head and leaves central brain regions largely unaffected. We have used this novel B distribution to provide in‐plane outer volume suppression (>98% suppression of extracerebral lipids) without the use of gradients. This novel B distribution is used in conjunction with a double inversion recovery method to provide suppression of extracerebral resonances with T1s greater than 400 ms, while having negligible effect on metabolite ratios of cerebral resonances with T1s > 1000 ms. Despite the use of two adiabatic pulses, the high efficiency of the ring distribution allows radiofrequency power deposition to be limited to 3‐4 W for a pulse repetition time of 1.5 sec. The short echo time enabled the acquisition of images of the human brain, displaying glutamate, glutamine, macromolecules, and other major cerebral metabolites. Magn Reson Med, 2010. © 2009 Wiley‐Liss, Inc.