bluuebunny/crossref_metadata_2025_split huggingface dataset:
Body‐sway characteristics during a static upright posture in the elderly
Authors: Demura Shin‐ichi , Kitabayashi Tamotsu , Aoki Hiroki 
Published: September 2008

Aim:  This study aimed to determine the reliability and sex and age‐level differences of body‐sway parameters, based on center of pressure (COP) measurements, during a static upright posture in the elderly and to clarify their body‐sway characteristics in comparison with those of young adults.Methods:  The subjects were 50 healthy elderly and 50 healthy young adults. They had no evidence or known history of disorder. The data sampling frequency was 20 Hz. Thirty‐six highly reliable parameters were selected from the following seven domains: distance; position; distribution of amplitude; area; velocity; power spectrum; and vector. In addition, four body‐sway factors (unit time sway, front‐back sway and a left‐right sway and the high‐frequency band power) were also measured.Results:  In the elderly, most body‐sway parameters had very high reliability and did not show significant sex or age‐level differences. The degree of body sway was greater in the elderly than in young adults, and marked differences were found, especially in sway velocity and periodicity. The four body‐sway factors showed almost the same tendency as the 32 sway parameters.Conclusion:  We judged that the body sway in the elderly showed large individual differences. Approximately 10% of the elderly subjects may be outside the standard range as compared to young adults, mainly in parameters relating to velocity and spectrum. Because the body‐sway characteristics of the elderly are considerably different from those of young adults, we may need unique criteria to evaluate their body sway.
Empathic neural reactivity to noxious stimuli delivered to body parts and non‐corporeal objects
Authors: Costantini Marcello , Galati Gaspare , Romani Gian Luca , Aglioti Salvatore M. 
Published: September 2008

AbstractNeuroimaging studies report that the experience of observing or imagining the pain of others is mapped on a set of neural structures that largely overlap those called into play during the personal experience of pain (the so‐called pain matrix). Empathy for pain is a multifaceted process that may be triggered by higher‐order variables (such as imagination of others’ suffering) or by the direct vision of painful situations. Most functional magnetic resonance imaging studies indicate that the empathic mapping of others’ pain may rely on the affective and not on the sensorimotor division of the pain matrix. However, as empathy for pain is a complex, multifarious process, it is possible that different brain regions, even beyond the classic pain matrix, may be called into action in different circumstances. By using functional magnetic resonance imaging we explored the neural activity induced by needles deeply penetrating a hand or a non‐corporeal object. We found that observation of pain in others brought about activation in the middle cingulate, left premotor and left and right supramarginal regions. This pattern of neural activity indicates that the direct vision of strong painful stimuli delivered to others activates neural regions in the onlooker’s brain specifically concerned with the resonant, interindividual sharing of basic sensorimotor reactivity to pain. We also found that bilateral posterior parietal and temporo‐occipital regions were activated during observation of painful stimuli delivered to the body of others as well as to non‐body stimuli. Therefore, our study expands current knowledge on the neural reactivity to potentially dangerous stimuli delivered in the peripersonal space.
Postinhibitory rebound spikes are modulated by the history of membrane hyperpolarization in the SCN
Authors: Tremere Liisa A. , Pinaud Raphael , Irwin Robert P. , Allen Charles N. 
Published: September 2008

AbstractThe suprachiasmatic nucleus (SCN) of the hypothalamus regulates biological circadian time thereby directly impacting numerous physiological processes. The SCN is composed almost exclusively of γ‐aminobutyric acid (GABA)ergic neurons, many of which synapse with other GABAergic cells in the SCN to exert an inhibitory influence on their postsynaptic targets for most, if not all, phases of the circadian cycle. The overwhelmingly GABAergic nature of the SCN, along with its internal connectivity properties, provide a strong model to examine how inhibitory neurotransmission generates output signals. In the present work we show that hyperpolarizations that range from 5 to 1000 ms elicit rebound spikes in 63% of all SCN neurons tested in voltage‐clamp in the SCN of adult rats and hamsters. In current‐clamp recordings, hyperpolarizations led to rebound spike formation in all cells; however, low‐amplitude or short‐duration current injections failed to consistently activate rebound spikes. Increasing the duration of hyperpolarization from 5 to 1000 ms is strongly and positively correlated with enhanced spike probability. Additionally, the magnitude of hyperpolarization exerts a strong influence on both the amplitude of the spike, as revealed by voltage‐clamp recordings, and the latency to peak current obtained in either voltage‐ or current‐clamp mode. Our results suggest that SCN neurons may use rebound spikes as one means of producing output signals from a largely interconnected network of GABAergic neurons.
Electrical properties of interneurons found within the trigeminal motor nucleus
Authors: McDavid Sarah , Verdier Dorly , Lund James P. , Kolta Arlette 
Published: September 2008

AbstractThe trigeminal motor nucleus contains the somata of motoneurons innervating the jaw muscles, but also those of interneurons that we have characterized morphologically and immunohistochemically previously. Here we compare their basic physiological characteristics and synaptic inputs from the peri‐trigeminal area (PeriV) to those of motoneurons using whole‐cell recordings made with pipettes containing biocytin in brainstem slices of rats that had a tracer injected into their masseters. Values for input resistance, spike duration and overall duration of afterhyperpolarization (AHP) were greater for interneurons than for motoneurons. Some interneurons (44%) and motoneurons (33%) had an outward rectification during depolarization. Hyperpolarization‐induced inward rectification was seen predominantly in interneurons (85% vs. 31% for motoneurons). Few interneurons (15%) showed depolarization and time‐dependent firing frequency accommodation, while half (52%) of the motoneurons did. Rebound excitation at the offset of hyperpolarization was more common in interneurons than in motoneurons (62% vs. 34%). Both populations received synaptic inputs from PeriV. These inputs were predominantly excitatory and were mediated by non‐N‐methyl‐d‐aspartate glutamatergic receptors. Response latencies and rise times of the evoked potentials were longer in interneurons than in motoneurons, suggesting that some of the inputs to interneurons could be polysynaptic and/or occurring at distal dendritic locations. Miniature synaptic events could be seen in about half of the neurons in both populations. These results suggest that interneurons can be clearly distinguished from motoneurons on the basis of some electrophysiological properties like the input resistance and spike and AHP durations, and the kinetics of their synaptic inputs from adjacent areas.
Repetitive transcranial magnetic stimulation over the primary motor cortex disrupts early boost but not delayed gains in performance in motor sequence learning
Authors: Hotermans Christophe , Peigneux Philippe , De Noordhout Alain Maertens , Moonen Gustave , Maquet Pierre 
Published: September 2008

AbstractIn humans the consolidation of recently learned motor skills is a multi‐step process. We previously showed that performance on the finger‐tapping task (FTT; i.e. a sequential motor skill) temporarily improves early on, 5–30 min after practice has ended, but not 4 h later. In the absence of any further practice to the task, this early boost in performance was predictive of the performance levels eventually achieved 48 h later, suggesting its functional relevance for long‐term memory consolidation [Hotermans, Peigneux, Maertens de Noordhout, Moonen, and Maquet (2006) Early boost and slow consolidation in motor skill learning. Learn. Mem., 13, 580–583]. Here, we focused on the role of the primary motor cortex (M1) in consolidation using repetitive transcranial magnetic stimulation (rTMS) applied immediately before testing at 30 min, 4 or 24 h after practice of the FTT. Immediately after learning, rTMS over M1 depressed the early boost in performance, but did not affect the delayed improvement observed 48 h later. Four and 24 h after practice, rTMS did not disrupt performance anymore. These results suggest that M1 supports performance during the early post‐training phase of motor skill consolidation, but is no longer mandatory in the subsequent, delayed stages of consolidation.
Effects of hypocretin (orexin) neuronal loss on sleep and extracellular adenosine levels in the rat basal forebrain
Authors: Murillo‐Rodriguez Eric , Liu Meng , Blanco‐Centurion Carlos , Shiromani Priyattam J. 
Published: September 2008

AbstractNeurons containing the neuropeptide hypocretin (HCRT, orexin) are localized only in the lateral hypothalamus, from where they innervate multiple regions implicated in arousal, including the basal forebrain. HCRT activation of downstream arousal neurons is likely to stimulate release of endogenous factors. One such factor is adenosine, which in the basal forebrain increases in level with wakefulness and decreases with sleep, and is hypothesized to regulate the waxing and waning of sleep drive. Does loss of HCRT neurons affect adenosine levels in the basal forebrain? Is the increased sleep that accompanies HCRT loss a consequence of higher adenosine levels in the basal forebrain? In the present study, we investigated these questions by lesioning the HCRT neurons with HCRT‐2–saporin (HCRT‐2–SAP) and measuring sleep and extracellular levels of adenosine in the basal forebrain. In separate groups of rats, the neurotoxin HCRT‐2–SAP or saline was administered locally to the lateral hypothalamus, and 80 days later adenosine and sleep were assessed. Rats given the neurotoxin had a 94% loss of HCRT neurons. These rats woke less at night, and had more rapid eye movement sleep, which is consistent with HCRT hypofunction. These rats also had more sleep after brief periods of sleep deprivation. However, in the lesioned rats, adenosine levels did not increase with 6 h of sleep deprivation, whereas an increase in adenosine levels occurred in rats without lesion of the HCRT neurons. These findings indicate that adenosine levels do not increase with wakefulness in rats with a HCRT lesion, and that the increased sleep in these rats occurs independently of adenosine levels in the basal forebrain.
The WldS gene delays axonal but not somatic degeneration in a rat glaucoma model
Authors: Beirowski Bogdan , Babetto Elisabetta , Coleman Michael P. , Martin Keith R. 
Published: September 2008

AbstractGlaucoma is a leading cause of blindness caused by progressive degeneration of retinal ganglion cells (RGCs) and their axons. The pathogenesis of glaucoma remains incompletely understood, but optic nerve (ON) axonal injury appears to be an important trigger of RGC axonal and cell body degeneration. Rat models are widely used in glaucoma research to explore pathogenic mechanisms and to test novel neuroprotective approaches. Here we investigated the mechanism of axon loss in glaucoma, studying axon degeneration in slow Wallerian degeneration (WldS) rats after increasing intraocular pressure. WldS delays degeneration of experimentally transected axons for several weeks, so it can provide genetic evidence for Wallerian‐like degeneration in disease. As apoptosis is unaffected, WldS also provides information on whether cell death results from axon degeneration or arises independently, an important question yet to be resolved in glaucoma. Having confirmed expression of WldS protein, we found that WldS delayed ON axonal degeneration in experimental rat glaucoma for at least 2 weeks, especially in proximal ON where wild‐type axons are most severely affected. The duration of axonal protection is similar to that after ON transection and crush, suggesting that axonal degeneration in glaucoma follows a Wallerian‐like mechanism. Axonal degeneration must be prevented for RGCs to remain functional, so pharmacologically mimicking and enhancing the protective mechanism of WldS could offer an important route towards therapy. However, WldS did not protect RGC bodies in glaucoma or after ON lesion, suggesting that combination treatments protecting both axons and cell bodies offer the best therapeutic prospects.
Specific properties of sodium currents in multipotent striatal progenitor cells
Authors: Wasner Ulrike , Geist Beate , Battefeld Arne , Bauer Peter , Müller Jana , Rolfs Arndt , Strauss Ulf 
Published: September 2008

AbstractThis study investigates the impact of intrinsic currents on early neural development. A rat striatal ST14A cell line immortalized by SV40 large T antigen was employed as a model system because these cells act as multipotent neural progenitors when maintained at a permissive temperature of 33°C. The whole‐cell patch‐clamp, molecular and immunocytochemical experiments point to a unique role of sodium currents in the multipotential stage of neural development. In initial experiments, action potential‐like responses were only present when multipotential ST14A cells were substantially hyperpolarized. This led us to presume that sodium channels were only recruited during deep hyperpolarization. Subsequent voltage‐clamp studies confirmed a remarkably hyperpolarized steady‐state inactivation of the sodium currents and also showed that the underlying channels were tetrodotoxin resistant. Direct comparison with cells whose neuronal fate was already determined, i.e. short‐term cultured striatal cells isolated at embryonic day 14 and after birth (post‐natal day 0), showed that both traits are unique to ST14A cells. However, sodium currents in all three groups had a fast time‐ and voltage‐dependent activation, as well as full inactivation with roughly similar kinetics. The peculiarity in ST14A might be explained by a relative excess of heart‐type NaV1.5 and particularly its splice variant NaV1.5a, as suggested by reverse transcription‐polymerase chain reaction results. We conclude that multipotent neural progenitor cells express Na+ channels in their membrane irrespective of their fate but these channels have little effect due to their subunit composition, which is regulated by alternative splicing.
The Commodity Terms of Trade, Unit Roots, and Nonlinear Alternatives: A Smooth Transition Approach
Authors: Balagtas Joseph V. , Holt Matthew T. 
Published: September 2008

AbstractThis article extends the recent literature on the Prebisch‐Singer hypothesis of a long‐run decline in the relative prices of primary commodities. Our main innovation is testing for and estimating nonlinear alternatives to a secular deterioration. Specifically, we use bootstrap procedures to test the linear unit root model against models belonging to the family of smooth transition autoregressions (STARs) for twenty‐four commodities, 1900–2003. In nineteen cases we reject the linear null at usual significance levels. In sixteen cases we are able to successfully fit STAR‐type models. Simulation results show there is little support for the Prebisch‐Singer hypothesis.
Crop Yield Skewness Under Law of the Minimum Technology
Authors: Hennessy David A. 
Published: September 2008

AbstractNo satisfactory motivation has been forwarded in favor of any crop yield distribution, including the normal. This article explores the foundations of yield distributions for the Law of the Minimum resource constraint technology at the plot level of analysis. With independent, identical, uniform resource availability distributions the yield skew is positive, whereas it is negative whenever the distributions are normal. Simulations show how asymmetries in resource availabilities determine skewness. It is suggested that a negative yield skew occurs whenever production is tightly controlled so that the left tails of some resources availabilities distributions are thin. Irrigation may increase yield skewness.
Valuing Water Quality as a Function of Water Quality Measures
Authors: Egan Kevin J. , Herriges Joseph A. , Kling Catherine L. , Downing John A. 
Published: September 2008

AbstractEmploying a unique and rich data set of water quality attributes in conjunction with detailed household characteristics and trip information, we develop a mixed logit model of recreational lake usage and undertake thorough model specification and fitting procedures to identify the best set of explanatory variables, and their functional form for the estimated model. Our empirical analysis shows that individuals are responsive to the full set of water quality measures used by biologists to identify the impaired status of lakes. Thus, changes in these quality measures are not simply a scientific exercise, but they also translate into changes in the recreational usage patterns and well‐being of individual households. Willingness‐to‐pay (WTP) estimates are reported based on improvements in these physical measures.
Conservation Payments, Liquidity Constraints, and Off‐Farm Labor: Impact of the Grain‐for‐Green Program on Rural Households in China
Authors: Uchida Emi , Rozelle Scott , Xu Jintao 
Published: September 2008

AbstractThis study evaluates the labor response of rural households participating in the Grain‐for‐Green program in China, the largest payments for ecosystem services program in the developing world. Using a panel data set that we designed and implemented, we find that the participating households are increasingly shifting their labor endowment from on‐farm work to the off‐farm labor market. However, the effects vary depending on the initial level of human and physical capital. The results support the view that one reason why the participants are more likely to find off‐farm employment is because the program is relaxing households' liquidity constraints.
On the Consumer Value of Complementarity: A Benefit Function Approach
Authors: Baggio Michele , Chavas Jean‐Paul 
Published: September 2008

AbstractThe article develops a conceptual model of the consumer value of complementarity and illustrates its usefulness in an application to fisheries. Complementarity arises when some goods have a positive effect on the marginal value of other goods. We propose a measurement of the value of complementarity based on the benefit function. Our econometric analysis of fish consumption in Italy examines these issues, with special attention given to dynamics. Our results show that, while short‐run fish demand is characterized by substitution relationships, complementarity does develop in the intermediate run and in the long run.
Highgrading in Quota‐Regulated Fisheries: Evidence from the Icelandic Cod Fishery
Authors: Kristofersson Dadi , Rickertsen Kyrre 
Published: September 2008

AbstractA model with nonlinear discarding costs is developed for a fishery with an individual transferable quota (ITQ) program. The model shows that limited hold capacity and ITQs provide incentives to discard fish. The model is applied to the Icelandic ITQ‐regulated cod fishery to test for highgrading and to predict the discarded quantities of different grades of fish. The results indicate that vessels are involved in highgrading, but there is no evidence of quota price‐induced highgrading. The predicted total discarded quantities are 4.7% and 2.7% of total landings for gillnet and longline vessels, respectively. These correspond well with official biometric estimates.
The Welfare Economics of a Biofuel Tax Credit and the Interaction Effects with Price Contingent Farm Subsidies
Authors: de Gorter Harry , Just David R. 
Published: September 2008

AbstractA framework is developed to analyze the effects of a biofuel consumer tax exemption and the interaction effects with a price contingent farm subsidy. Ethanol prices rise above the gasoline price by the amount of the tax credit. Corn farmers gain directly while gasoline consumers only gain from any reduction in world oil prices due to the extra ethanol production. Domestic oil producers lose. Historically, the intercept of the ethanol supply curve is above the gasoline price. Hence, part of the tax credit is redundant and represents “rectangular” deadweight costs that dwarf triangular deadweight cost measures of traditional farm subsidies.
Valuation of New Products in Attribute Space
Authors: Pofahl Geoffrey M. , Richards Timothy J. 
Published: September 2008

AbstractWe contribute to the literature on new product valuation by presenting a model of new product introduction based on the distance metric (DM) approach of Pinkse, Slade, and Brett (2002). Models based on the DM approach are capable of dealing with highly differentiated food categories that are often responsible for the lion's share of new product activity. Furthermore, since new products are typically characterized by differences in observable attributes, the DM approach is appropriate in that it directly accounts for such differences. Our findings reveal that consumers benefit from new products even when the number of alternatives is already high.
Classical vs. Modern Managerial CSR Perspectives: Insights from Lebanese Context and Cross‐Cultural Implications
Authors: JAMALI DIMA , SIDANI YUSUF 
Published: September 2008

ABSTRACTCorporate social responsibility (CSR) is a concept that has acquired a new resonance in the global economy. With the advent of globalization, managers in different contexts have been exposed to the notion of CSR and are being pressured to adopt CSR initiatives. Yet in view of vastly differing national cultures and institutional realities, mixed orientations to CSR continue to be salient in different contexts, oscillating between the classical perspective which considers CSR as a burden on competitiveness and the modern perspective that views CSR as instrumental for business success. Capitalizing on the two‐dimensional CSR model developed by Quazi and O’Brien, Journal of Business Ethics, 25, 33–51 (2000), this article attempts to gauge managerial perspectives toward CSR in Lebanon. An empirical study of 119 Lebanese managers reveals that the majority of respondents (83 percent) are favorably inclined toward CSR with about 20 percent adhering to the modern paradigm, more than 50 percent adhering to a philanthropic view and 18 percent fitting into the classical camp. The findings are discussed and cross‐cultural implications drawn accordingly.
Banks, Insurance Companies, and Discrimination1
Authors: BLOCK WALTER , SNOW NICHOLAS , STRINGHAM EDWARD 
Published: September 2008

ABSTRACTThis article examines some of the reasons why banks and insurance companies have been accused of discrimination, and shows that this is by and large a false accusation. Economic analysis demonstrates that racial discrimination is not a profit‐maximizing strategy. Actually, unwise public policies are actually precluding many consumers from the market.