bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling direct effects of neural current on MRI
Authors: Heller Leon , Barrowes Benjamin E. , George John S. 
Published: November 2007

AbstractWe investigate the effect of the magnetic field generated by neural activity on the magnitude and phase of the MRI signal in terms of a phenomenological parameter with the dimensions of length; it involves the product of the strength and duration of these currents. We obtain an analytic approximation to the MRI signal when the neuromagnetically induced phase is small inside the MRI voxel. The phase shift is the average of the MRI phase over the voxel, and therefore first order in that phase; and the reduction in the signal magnitude is one half the square of the standard deviation of the MRI phase, which is second order. The analytic approximation is compared with numerical simulations. For weak currents the agreement is excellent, and the magnitude change is generally much smaller than the phase shift. Using MEG data as a weak constraint on the current strength we find that for a net dipole moment of 10 nAm, a typical value for an evoked response, the reduction in the magnitude of the MRI signal is two parts in 105, and the maximum value of the overall phase shift is $ \approx 4 \cdot 10^{-3} $, obtained when the MRI voxel is displaced 2/3 the size of the neuronal activity. We also show signal changes over a large range of values of the net dipole moment. We compare these results with others in the literature. Our model overestimates the effect on the MRI signal. Hum Brain Mapp 2009. © 2007 Wiley‐Liss, Inc.
Precise discrimination of object position in the human pulvinar
Authors: Fischer Jason , Whitney David 
Published: November 2007

AbstractVery little is known about the human pulvinar; suggestions for its function include relaying input from cortical areas, allocating visual attention, supporting feature binding, and other integrative processes. The diversity of hypotheses about pulvinar function highlights our lack of understanding of its basic role. A conspicuously missing piece of information is whether the human pulvinar encodes visual information topographically. The answer to this question is crucial, as it dramatically constrains the sorts of computational and cognitive processes that the pulvinar might carry out. Here we used fMRI to test for position‐sensitive encoding in the human pulvinar. Subjects passively viewed flickering Gabor stimuli, and as the spatial separation between Gabors increased, the correlation between patterns of activity across voxels within the right pulvinar decreased significantly. The results demonstrate the existence of precise topographic coding in the human pulvinar lateralized to the right hemisphere, and provide a means of functionally localizing this topographic region. Hum Brain Mapp 2009. © 2007 Wiley‐Liss, Inc.
Preferences for ‘life‐saving’ programmes: Small for all or gambling for the prize?
Authors: Gyrd‐Hansen Dorte , Kristiansen Ivar Sønbø 
Published: November 2007

AbstractMuch of the literature on the value of life is based on the valuation of small reductions in mortality risk with many remaining life years if the fatal outcome is avoided. In contrast, this paper explores valuations of interventions which with varying probability levels offer smaller or moderate life year health gains. We interviewed 2900 respondents about hypothetical therapies that involved life year gains in the range of 1–180 months with a probability of 1 to 1/180, presented both in individual and societal perspectives. The results of the study indicate that the value of the hypothetical treatments is not a simple function of probability and gain. Rather, respondents seem to adopt thresholds when they value treatment offers. This results in kinked utility functions where the expected individual utility is significantly decreased when the gain in life expectancy is 6 months or less, and markedly increased if the probability of gains exceeds 1/12. There were only small differences in valuations across the individual and societal perspectives, suggesting that preferences for dispersion of health gains are not only a reflection of equity considerations. If the results of this study reflect widespread preferences, the standard methods in cost‐effectiveness/cost‐utility analysis may misinform decision makers. Copyright © 2007 John Wiley & Sons, Ltd.
The effect of information in the utilization of preventive health‐care strategies: An application to breast cancer
Authors: Witt Julia 
Published: November 2007

AbstractThis paper investigates the net benefit of mammography. A theoretical expected utility (EU) model shows that increases in breast cancer risk, decreases in false‐negative and false‐positive rates, decreases in cost and increases/decreases in quality of life with early/late‐stage breast cancer increase the net benefit of mammography. The theoretical findings are tested in an empirical analysis using Canadian data. The empirical results are broadly consistent with the EU hypothesis. Results suggest that women at higher risk are more likely to obtain a mammogram. In particular, individuals are significantly more likely to have had a time‐appropriate mammogram if the mother's cause of death was breast cancer, and if the sister had breast cancer. The results also show that older age (related to higher risk and more accurate mammograms) increases mammography use, and that decreases in time and opportunity costs, and better health behaviours generally have the same effect. Copyright © 2007 John Wiley & Sons, Ltd.
Anthropometric factors and risk of melanoma in women: A pooled analysis
Authors: Olsen Catherine M. , Green Adèle C. , Zens Michael S. , Stukel Therese A. , Bataille Veronique , Berwick Marianne , Elwood J. Mark , Gallagher Richard , Holly Elizabeth A. , Kirkpatrick Connie , Mack Thomas , Østerlind Anne , Rosso Stefano , Swerdlow Anthony J. , Karagas Margaret R. 
Published: November 2007

AbstractAnthropometric factors such as height, weight and body mass index are related to the occurrence of certain malignancies in women including cancers of the breast, ovary and endometrium. Several studies have investigated the relation between height and weight or body mass and the risk of cutaneous melanoma in women, but results have been inconsistent. We conducted a collaborative analysis of these factors using the original data from 8 case–control studies of melanoma in women (2,083 cases and 2,782 controls), with assessment of the potential confounding effects of socioeconomic, pigmentary and sun exposure‐related factors. Women in the highest quartile of height had an increased risk of melanoma [pooled odds ratio (pOR) 1.3, 95% confidence interval (CI) 1.1–1.6]. We also found an elevated risk associated with weight gain in adult life of 2 kg or more (pOR 1.5, 95% CI 1.1–2.0). Stratifying by age at melanoma diagnosis (<50, ≥50 yr), we found this risk greater among women <50 yr of age. Associations were unaffected by adjustment for other known risk factors for melanoma. There was no evidence that the effects varied for different histologic subtypes of cutaneous melanoma. There was no association with body weight per se, body mass index, or body surface area, either recent or in young adulthood. In aggregate, data from these studies suggest that greater height and weight gain may be risk factors for cutaneous melanoma in women. © 2007 Wiley‐Liss, Inc.
Gene expression profiling related to the enhanced erythropoiesis in mouse bone marrow cells
Authors: Yang Hee‐Young , Jeong Dong Kee , Kim Seok‐Ho , Chung Kyoung‐Jin , Cho Eun‐Jin , Jin Cheng Hao , Yang Ung , Lee Sang Ryeul , Lee Dong‐Seok , Lee Tae‐Hoon 
Published: November 2007

AbstractPeroxiredoxin II knockout (Prdx II−/−) mice had a spontaneous phenotype of hemolytic anemia. In this study, we found that Ter‐119+CD71+ cells increased in Prdx II−/− mice bone marrow (BM) at 8 weeks of age. We examined the differential expression profiles to bone marrow cells (BMCs) between Prdx II+/+ and Prdx II−/− mice using a cDNA microarray. We identified the 136 candidates were differentially expressed a greater twofold increase or decrease than EPO receptor. In this study, we focused on the up‐regulated NBPs during erythropoietic differentiation. According to cDNA microarray results, six NBPs except zfp‐127 were up‐regulated during erythropoiesis in Prdx II−/− mice. Among the six candidates, eIF3‐p44, hnRNPH1, G3bp, and Zfpm‐1 were dramatically increased at day 7 of the in vitro erythropoietic differentiation of human CD34+ cells. However, DJ‐1 and Rbm3 were slightly increased only at day 12. Our results suggest that up‐regulated NBPs might be involved during erythropoietic differentiation. J. Cell. Biochem. 104: 295–303, 2008. © 2007 Wiley‐Liss, Inc.
PTH/cAMP/PKA signaling facilitates canonical Wnt signaling via inactivation of glycogen synthase kinase‐3β in osteoblastic Saos‐2 cells
Authors: Suzuki Akira , Ozono Keiichi , Kubota Takuo , Kondou Hiroki , Tachikawa Kanako , Michigami Toshimi 
Published: November 2007

AbstractAlthough the intermittent administration of PTH is known to stimulate the bone formation, the underlying mechanisms are not fully understood. Here we investigated the crosstalk between PTH/cAMP signaling and canonical Wnt signaling using the human osteoblastic cell line Saos‐2. Treatment with PTH or forskolin, an activator of adenylate cyclase, facilitated T‐cell factor (TCF)‐dependent transactivation in a dose‐dependent manner, which was abolished by pre‐treatment with a PKA inhibitor, H89. Wnt3a and forskolin synergistically increased the TCF‐dependent transactivation. Interestingly, intermittent treatment with PTH enhanced the TCF‐dependent transactivation more profoundly than continuous treatment. In addition to the effects on TCF‐dependent reporter activity, treatment with PTH or forskolin resulted in the increased expression of endogenous targets of Wnts, Wnt‐induced secreted protein 2 (WISP2) and naked cuticle 2 (NKD2). We then investigated the convergence point of PTH/cAMP signaling and the canonical Wnt pathway. Western blotting demonstrated that GSK‐3β was rapidly phosphorylated at Ser9 on treatment with PTH or forskolin, leading to its inactivation. Moreover, overexpression of a constitutively active mutant of GSK‐3β abolished the TCF‐dependent transactivation induced by forskolin. On the other hand, overexpression of the Wnt antagonist Dickkopf‐1 (DKK1) failed to cancel the effects of forskolin on the canonical Wnt pathway. Interestingly, treatment with Wnt3a markedly reduced the forskolin‐induced expression of receptor activator of NF‐κB ligand (RANKL), a target gene of PTH/cAMP/PKA. These results suggest that cAMP/PKA signaling activates the canonical Wnt pathway through the inactivation of GSK‐3β, whereas Wnt signaling might inhibit bone resorption through a negative impact on RANKL expression in osteoblasts. J. Cell. Biochem. 104: 304–317, 2008. © 2007 Wiley‐Liss, Inc.
Partitioning or bundling? Perceived fairness of the surcharge makes a difference
Authors: Sheng Shibin , Bao Yeqing , Pan Yue 
Published: November 2007

AbstractPartitioned pricing charges a base price and a surcharge instead of an equivalent all‐inclusive price. In contrast, a bundling strategy offers a bundled price instead of separate prices for products in one package. Which pricing practice is more profitable? Previous research has shown conflicting results. This research identifies the boundary conditions which circumscribe the profitability of partitioned and bundled pricing. Results of three experiments indicate that the relative significance of the surcharge to the base price influences consumers' perception of the fairness of the surcharge, which in turn influences consumer purchase intentions. Furthermore, given the same level of surcharge, consumers' perceptions of the fairness of the surcharge moderates the effect of the pricing strategies. Thus, perceived fairness of the surcharge appears to be the key in determining whether or not the partitioning strategy is more profitable than the bundling strategy. © 2007 Wiley Periodicals, Inc.
An empirical analysis of the effect of volunteer labor on public library employment
Authors: Stine William F. 
Published: November 2007

AbstractThis study is an empirical investigation of the effect of library volunteers on public library demand for paid workers. Unlike previous studies, it estimates the impacts on different types of paid labor. The main purpose is to test whether volunteer labor replaced or complemented paid employees. A translog cost function is used to derive cost shares and elasticities of substitution for Pennsylvania public libraries. Cross‐elasticity estimates of substitution and input demand suggest a strong complementary relation between volunteers and professional workers. Most of the other Allen cross elasticities were not statistically significant. None of the estimates indicate that paid labor was being replaced by volunteers. Copyright © 2007 John Wiley & Sons, Ltd.
Carbon isotopic ratio analysis by gas chromatography/combustion/isotope ratio mass spectrometry for the detection of gamma‐hydroxybutyric acid (GHB) administration to humans
Authors: Saudan Christophe , Augsburger Marc , Mangin Patrice , Saugy Martial 
Published: November 2007

AbstractSince GHB (gamma‐hydroxybutyric acid) is naturally produced in the human body, clinical and forensic toxicologists must be able to discriminate between endogenous levels and a concentration resulting from exposure. To suggest an alternative to the use of interpretative concentration cut‐offs, the detection of exogenous GHB in urine specimens was investigated by means of gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). GHB was isolated from urinary matrix by successive purification on Oasis MCX and Bond Elute SAX solid‐phase extraction (SPE) cartridges prior to high‐performance liquid chromatography (HPLC) fractioning using an Atlantis dC18 column eluted with a mixture of formic acid and methanol. Subsequent intramolecular esterification of GHB leading to the formation of γ‐butyrolactone (GBL) was carried out to avoid introduction of additional carbon atoms for carbon isotopic ratio analysis. A precision of 0.3‰ was determined using this IRMS method for samples at GHB concentrations of 10 mg/L. The 13C/12C ratios of GHB in samples of subjects exposed to the drug ranged from −32.1 to −42.1‰, whereas the results obtained for samples containing GHB of endogenous origin at concentration levels less than 10 mg/L were in the range −23.5 to −27.0‰. Therefore, these preliminary results show that a possible discrimination between endogenous and exogenous GHB can be made using carbon isotopic ratio analyses. Copyright © 2007 John Wiley & Sons, Ltd.
Evaluating macrolichens and environmental variables as predictors of the diversity of epiphytic microlichens
Authors: BERGAMINI Ariel , STOFER Silvia , BOLLIGER Janine , SCHEIDEGGER Christoph 
Published: November 2007

Abstract:In contrast to the frequently assessed macrolichens, microlichens are rarely considered in biodiversity assessments despite their high species richness. Microlichens require generally a higher species identification effort than macrolichens. Thus, microlichens are more expensive to assess. Here we evaluate if macrolichen richness can be used as an indicator of total and threatened microlichen richness. Furthermore, we tested if different sets of environmental variables (modelled climatic variables, forest structure, altitude, etc.) improve the regression models based on macrolichens only or even replace the macrolichens as predictors. Multiple linear regressions were used to model species richness of microlichens, and Poisson regressions for threatened microlichens.On 237 forest plots (200 m2) distributed randomly across Switzerland, 77 macrolichens and 219 microlichens occurred. Macrolichen richness was positively related to the richness of microlichens (=0·27) and, in combination with threatened macrolichens as an additional predictor, also to the number of threatened microlichens (=0·14). Environmental variables alone and in different combinations explained between 0·20 and 0·41 () of the total variation of microlichen richness, and between 0·09 and 0·29 () of the total variation of threatened microlichen richness. All models based on environmental variables were considerably improved when macrolichens were included. Furthermore, macrolichen richness turned out to be the most important variable in explaining species richness of all, as well as threatened microlichens. The best models for total microlichen richness reached a of 0·56. Threatened microlichens were more difficult to model with the best model reaching a of 0·29.We conclude that in biodiversity assessments with scarce resources, lichen sampling could be focused on the better known macrolichens, at least in many temperate lowland and mountain forests. In combination with environmental variables, reliable predictions of microlichen richness can be expected. If the focus is on threatened microlichens, however, models were not reliable and specialized taxonomists are necessary to assess these species in the field.
Law, liberty, and Christian morality
Authors: SWAN KYLE 
Published: November 2007

AbstractThere is a long liberal political tradition of marshalling arguments aimed at convincing Christians that distinctively Christian reasons for issuing coercive laws are not sufficient to justify those laws. In the first part of this paper I argue that the two most popular of these arguments, attributable to Locke, will not reliably convince committed biblical Christians, nor, probably, should they. In the second part I argue that even if the Lockean arguments fail, committed biblical Christians should think that God has authorized the state only to fill the same general role that political liberals have identified for it.
A reply to Schlesinger's theodicy
Authors: GWIAZDA JEREMY 
Published: November 2007

AbstractIn Religion and Scientific Method, George Schlesinger presented a strikingly original theodicy. In this paper, I explain the strategy underlying Schlesinger's argument. I then present a parallel argument to indicate the weakness of Schlesinger's theodicy. Finally, I show that Schlesinger's theodicy assumes a false principle, and therefore fails.
Modified Newton's method applied to potential field based navigation for nonholonomic robots in dynamic environments
Authors: Ren Jing , McIsaac Kenneth A. , Patel Rajni V. 
Published: November 2007

SUMMARYThis paper is to investigate inherent oscillations problems of Potential Field Methods (PFMs) for nonholonomic robots in dynamic environments. In prior work, we proposed a modification of Newton's method to eliminate oscillations for omnidirectional robots in static environment. In this paper, we develop control laws for nonholonomic robots in dynamic environment using modifications of Newton's method. We have validated this technique in a multirobot search-and-forage task. We found that the use of the modifications of Newton's method, which applies anywhereC2continuous navigation functions are defined, can greatly reduce oscillations and speed up robot's movement, when compared to the standard gradient approaches.
CgNa, a type I toxin from the giant Caribbean sea anemoneCondylactis giganteashows structural similarities to both type I and II toxins, as well as distinctive structural and functional properties
Authors: Salceda Emilio , Pérez-Castells Javier , López-Méndez Blanca , Garateix Anoland , Salazar Hector , López Omar , Aneiros Abel , Ständker Ludger , Béress Lászlo , Forssmann Wolf-Georg , Soto Enrique , Jiménez-Barbero Jesús , Giménez-Gallego Guillermo 
Published: November 2007

CgNa (Condylactis gigantea neurotoxin) is a 47-amino-acid- residue toxin from the giant Caribbean sea anemone Condylactis gigantea. The structure of CgNa, which was solved by 1H-NMR spectroscopy, is somewhat atypical and displays significant homology with both type I and II anemone toxins. CgNa also displays a considerable number of exceptions to the canonical structural elements that are thought to be essential for the activity of this group of toxins. Furthermore, unique residues in CgNa define a characteristic structure with strong negatively charged surface patches. These patches disrupt a surface-exposed cluster of hydrophobic residues present in all anemone-derived toxins described to date. A thorough characterization by patch–clamp analysis using rat DRG (dorsal root ganglion) neurons indicated that CgNa preferentially binds to TTX-S (tetrodotoxin-sensitive) voltage-gated sodium channels in the resting state. This association increased the inactivation time constant and the rate of recovery from inactivation, inducing a significant shift in the steady state of inactivation curve to the left. The specific structural features of CgNa may explain its weaker inhibitory capacity when compared with the other type I and II anemone toxins.
Succinate modulation of H2O2 release at NADH:ubiquinone oxidoreductase (Complex I) in brain mitochondria
Authors: Zoccarato Franco , Cavallini Lucia , Bortolami Silvia , Alexandre Adolfo 
Published: November 2007

Complex I (NADH:ubiquinone oxidoreductase) is responsible for most of the mitochondrial H2O2 release, both during the oxidation of NAD-linked substrates and during succinate oxidation. The much faster succinate-dependent H2O2 production is ascribed to Complex I, being rotenone-sensitive. In the present paper, we report high-affinity succinate-supported H2O2 generation in the absence as well as in the presence of GM (glutamate/malate) (1 or 2 mM of each). In brain mitochondria, their only effect was to increase from 0.35 to 0.5 or to 0.65 mM the succinate concentration evoking the semi-maximal H2O2 release. GM are still oxidized in the presence of succinate, as indicated by the oxygen-consumption rates, which are intermediate between those of GM and of succinate alone when all substrates are present together. This effect is removed by rotenone, showing that it is not due to inhibition of succinate influx. Moreover, α-oxoglutarate production from GM, a measure of the activity of Complex I, is decreased, but not stopped, by succinate. It is concluded that succinate-induced H2O2 production occurs under conditions of regular downward electron flow in Complex I. Succinate concentration appears to modulate the rate of H2O2 release, probably by controlling the hydroquinone/quinone ratio.