bluuebunny/crossref_metadata_2025 huggingface dataset:
2‐Iodomelatonin prevents apoptosis of cerebellar granule neurons via inhibition of A‐type transient outward K+ currents
Authors: Hu Chang‐Long , Liu Zheng , Gao Zhen‐Yu , Zhang Zhi‐Hong , Mei Yan‐Ai
Published: December 2004

Abstract:  Compelling evidence indicates that excessive K+ efflux and intracellular K+ depletion are key early steps in apoptosis. Previously, we reported that apoptosis of cerebellar granular neurons induced by incubation under low K+ (5 mm) conditions was associated with an increase in delayed rectifier outward K+ current (IK) amplitude and caspase‐3 activity. Moreover, the melatonin receptor antagonist 4P‐PDOT abrogated the effects of 2‐iodomelatonin on IK augmentation, caspase‐3 activity and apoptosis. Here, we show that incubation under low K+/serum‐free conditions for 6 hr led to a dramatic increase in the A‐type transient outward K+ current (IA) (a 27% increase; n = 31); in addition, fluorescence staining showed that under these conditions, cell viability decreased by 30% compared with the control. Treatment with 2‐iodomelatonin inhibited the IA amplitude recorded from control and apoptotic cells in a concentration‐dependent manner and modified the IA channel activation kinetics of cells under control conditions. Moreover, 2‐iodomelatonin increased the viability of cell undergoing apoptosis. Interestingly, 4P‐PDOT did not abrogate the effect of 2‐iodomelatonin on IA augmentation under these conditions; in the presence of 4P‐PDOT (100 μm), 2‐iodomelatonin reduced the average IA by 41 ± 4%, which was similar to the effect of 2‐iodomelatonin alone. These results suggest that the neuroprotective effects of 2‐idomelatonin are not only because of its antioxidant or receptor‐activating properties, but rather that 2‐iodomelatonin may inhibit IA channels by acting as a channel blocker.
Determination of transport stoichiometry for two cation‐coupled myo‐inositol cotransporters: SMIT2 and HMIT
Authors: Bourgeois Francis , Coady Michael J. , Lapointe Jean‐Yves
Published: December 2004

Three different mammalian myo‐inositol cotransporters are currently known; two are Na+‐coupled (SMIT1 and SMIT2) and one is proton‐coupled (HMIT). Although their transport stoichiometries have not been directly determined, significant cooperativities in the Na+ activation of SMIT1 and SMIT2 suggest that more than one Na+ ion drives the transport of each myo‐inositol. The two techniques used here to determine transport stoichiometry take advantage of the electrogenicity of both SMIT2 and HMIT expressed in Xenopus oocytes. The first method compares the measurement of charge transferred into voltage‐clamped oocytes with the simultaneous uptake of radiolabelled substrate. The second approach uses high accuracy volume measurements to determine the transport‐dependent osmolyte uptake and compares it to the amount of charge transported. This method was calibrated using a potassium channel (ROMK2) and was validated with the Na+/glucose cotransporter SGLT1, which has a known stoichiometry of 2 : 1. Volume measurements indicated a stoichiometric ratio of 1.78 ± 0.27 ion per α‐methyl‐glucose (αMG) for SGLT1 whereas the radiotracer uptake method indicated 2.14 ± 0.05. The two methods yielded a SMIT2 stoichiometry measurement of 1.75 ± 0.30 and 1.82 ± 0.10, both in agreement with a 2 Na+:1 myo‐inositol stoichiometry. For HMIT, the flux ratio was 1.02 ± 0.04 charge per myo‐inositol, but the volumetric method suggested 0.67 ± 0.05 charge per myo‐inositol molecule. This last value is presumed to be an underestimate of the true stoichiometry of one proton for one myo‐inositol molecule due to some proton exchange for osmotically active species. This hypothesis was confirmed by using SGLT1 as a proton‐driven glucose cotransporter. In conclusion, despite the inherent difficulty in estimating the osmotic effect of a proton influx, the volumetric method was found valuable as it has the unique capacity of detecting unidentified transported substrates.
GABA‐mediated control of hypocretin‐ but not melanin‐concentrating hormone‐immunoreactive neurones during sleep in rats
Authors: Alam Md. Noor , Kumar Sunil , Bashir Tariq , Suntsova Natalia , Methippara Melvi M. , Szymusiak Ronald , McGinty Dennis
Published: December 2004

The perifornical‐lateral hypothalamic area (PF‐LHA) has been implicated in the regulation of behavioural arousal. The PF‐LHA contains several cell types including neurones expressing the peptides, hypocretin (HCRT; also called orexin) and melanin‐concentrating hormone (MCH). Evidence suggests that most of the PF‐LHA neurones, including HCRT neurones, are active during waking and quiescent during non‐rapid eye movement (non‐NREM) sleep. The PF‐LHA contains local GABAergic interneurones and also receives GABAergic inputs from sleep‐promoting regions in the preoptic area of the hypothalamus. We hypothesized that increased GABA‐mediated inhibition within PF‐LHA contributes to the suppression of neuronal activity during non‐REM sleep. EEG and EMG activity of rats were monitored for 2 h during microdialytic delivery of artificial cerebrospinal fluid (aCSF) or bicuculline, a GABAA receptor antagonist, into the PF‐LHA in spontaneously sleeping rats during the lights‐on period. At the end of aCSF or bicuculline perfusion, rats were killed and c‐Fos immunoreactivity (Fos‐IR) in HCRT, MCH and other PF‐LHA neurones was quantified. In response to bicuculline perfusion into the PF‐LHA, rats exhibited a dose‐dependent decrease in non‐REM and REM sleep time and an increase in time awake. The number of HCRT, MCH and non‐HCRT/non‐MCH neurones exhibiting Fos‐IR adjacent to the microdialysis probe also increased dose‐dependently in response to bicuculline. However, significantly fewer MCH neurones exhibited Fos‐IR in response to bicuculline as compared to HCRT and other PF‐LHA neurones. These results support the hypothesis that PF‐LHA neurones, including HCRT neurones, are subject to increased endogenous GABAergic inhibition during sleep. In contrast, MCH neurones appear to be subject to weaker GABAergic control during sleep.
Effect of ammonium on the expression of osmosensitive genes in Madin–Darby canine kidney cells
Authors: Neuhofer Wolfgang , Vastag Monika , Fraek Maria‐Luisa , Beck Franz‐X.
Published: December 2004

The cells of the kidney medulla are exposed routinely to high extracellular concentrations of various solutes including NaCl, urea and ammonium (NH4+). Although it is well established that the expression of a variety of osmosensitive genes and proteins, which confer cytoprotection on renal medullary cells, is induced by high NaCl concentrations, the role of NH4+ in these cellular responses is unclear. This study thus addressed the effect of NH4+ on the expression of the betaine/GABA transporter (BGT‐1), the sodium/myo‐inositol cotransporter (SMIT), aldose reductase (AR), and heat shock protein 70 (HSP70) in Madin–Darby canine kidney (MDCK) cells, using Northern and Western blot analyses and enzyme‐linked immunosorbent assay (ELISA). The incidence of apoptosis was monitored by determining caspase‐3 activity and annexin V binding. Addition of NH4Cl (50 mm; total osmolality 400 mosmol (kg H2O)−1 to the medium was more effective than equiosmolar NaCl in increasing BGT‐1 and HSP70 mRNA abundance, but less effective in enhancing BGT‐1 and HSP70 expression at the protein level. Qualitatively similar results were obtained for SMIT and AR mRNAs. Exposure to both isotonic and hypertonic, NH4Cl‐containing medium enhanced apoptosis compared with equiosmolar, NaCl‐containing media. These results suggest that, in addition to NaCl, NH4Cl may play a role in regulating the intracellular accumulation of organic osmolytes, the abundance of HSP70 and cell turnover in the renal medulla in vivo.
Mobilization of sarcoplasmic reticulum stores by hypoxia leads to consequent activation of capacitative Ca2+ entry in isolated canine pulmonary arterial smooth muscle cells
Authors: Ng Lih Chyuan , Wilson Sean M. , Hume Joseph R.
Published: December 2004

Capacitative Ca2+ entry (CCE) has been speculated to contribute to Ca2+ influx during hypoxic pulmonary vasoconstriction (HPV). The aim of the present study was to directly test if acute hypoxia causes intracellular Ca2+ concentration ([Ca2+]i) rises through CCE in canine pulmonary artery smooth muscle cells (PASMCs). In PASMCs loaded with fura‐2, hypoxia produced a transient rise in [Ca2+]i in Ca2+‐free solution, indicating Ca2+ release from the intracellular Ca2+ stores. Subsequent addition of 2 mm Ca2+ in hypoxia elicited a sustained rise in [Ca2+]i, which was partially inhibited by 10 μm nisoldipine. The dihydropyridine‐insensitive rise in [Ca2+]i was due to increased Ca2+ influx, because it was abolished in Ca2+‐free solution and hypoxia was shown to significantly enhance the rate of Mn2+ quench of fura‐2 fluorescence. The dihyropyridine‐insensitive rise in [Ca2+]i and the increased rate of Mn2+ quench of fura‐2 fluorescence were inhibited by 50 μm SKF 96365 and 500 μm Ni2+, but not by 100 μm La3+ or 100 μm Gd3+, exhibiting pharmacological properties characteristic of CCE. In addition, predepletion of the intracellular Ca2+ stores inhibited the rise in [Ca2+]i induced by hypoxia. These results provide the first direct evidence that acute hypoxia, by causing Ca2+ release from the intracellular stores, activates CCE in isolated canine PASMCs, which may contribute to HPV.
Kinematic and Dynamic Simulation of a Dual-Beam Pumping Unit for Increasing Stroke and Reducing Force
Authors: Yi Lu , Leinonen Tatu
Published: December 2004

Based on a conventional walking-beam pumping unit, a dual-beam pumping unit for increasing stroke and reducing force is presented, and an approach involving computer kinematic and dynamic simulation of this pumping unit is introduced in this paper. First, all three-dimensional parts are constituted and assembled to create a three-dimensional virtual mechanism of the dual-beam pumping unit for increasing stroke and reducing force. Second, all necessary joints are constituted, and all prescribed loads and input rotation are exerted onto the relative joints of the virtual mechanism. Finally, some simulation curves of the displacement, velocity, acceleration of the sucker rod, the working force exerted onto some key joints, and the driving torque of the crank from the three-dimensional virtual mechanism are obtained. The simulation results prove that the stroke of the sucker rod is 4.5-fold compared to a conventional walking-beam pumping unit, while the driving torque of the crank and all working forces exerted onto the key joints are notably reduced.
Proposed Practical Methods to Estimate Rock Strength and Tooth Wear While Drilling With Roller-Cone Bits
Authors: Ohno T. , Karasawa H. , Kosugi M. , Rowley J. C.
Published: December 2004

The authors have previously developed and proposed methods to estimate the in situ rock strength and tooth wear while drilling with roller-cone bits [Karasawa et al., 2002, ASME J. Energy Resour. Technol. 124, pp. 125–132 (Pt. 1) 133–140 (Pt. 2)]. The purpose of this paper is to provide a follow-up to these two reports and to propose, for both previous methods, alternate techniques that can be more readily implemented in the field than those originally presented. The data presented in Part 1 of the previously mentioned work [1] were reanalyzed in order to find a new and simple parameter that can be used to estimate rock strength. This parameter uses only one set of data that consists of bit weight, torque, penetration rate, rotary speed, and bit diameter. It was also demonstrated that the effect of tooth wear on this new parameter is small. In addition, more practical methods, which employ two parameters, are derived and proposed to evaluate the tooth wear of roller-cone bits.
Dynamic Snap-Through of a Shallow Arch Under a Moving Point Load
Authors: Chen Jen-San , Lin Jian-San
Published: December 2004

In this paper we study the dynamic behavior of a shallow arch under a point load Q traveling at a constant speed. Emphasis is placed on finding whether snap-through buckling will occur. In the quasi-static case when the moving speed is almost zero, there exists a critical load Qcr in the sense that no static snap-through will occur as long as Q is smaller than Qcr. In the dynamic case when the point load travels with a nonzero speed, the critical load Qcrd is, in general, smaller than the static one. When Q is greater than Qcrd, there exists a finite speed zone within which the arch runs the risk of dynamic snap-through either while the point load is still on the arch or after the point load leaves the arch. The boundary of this dangerous speed zone can be determined by a more conservative criterion, which employs the concept of total energy and critical energy barrier, to guarantee the safe passage of the point load. This criterion requires the numerical integration of the equations of motion only up to the instant when the point load reaches the other end of the arch.
Analytical Solution for Stochastic Response of a Fractionally Damped Beam
Authors: Agrawal Om P.
Published: December 2004

This paper presents a general analytical technique for stochastic analysis of a continuous beam whose damping characteristic is described using a fractional derivative model. In this formulation, the normal-mode approach is used to reduce the differential equation of a fractionally damped continuous beam into a set of infinite equations, each of which describes the dynamics of a fractionally damped spring-mass-damper system. A Laplace transform technique is used to obtain the fractional Green’s function and a Duhamel integral-type expression for the system’s response. The response expression contains two parts, namely, zero state and zero input. For a stochastic analysis, the input force is treated as a random process with specified mean and correlation functions. An expectation operator is applied on a set of expressions to obtain the stochastic characteristics of the system. Closed-form stochastic response expressions are obtained for white noise for two cases, and numerical results are presented for one of the cases. The approach can be extended to all those systems for which the existence of normal modes is guaranteed.
On the Characteristics of Bifurcation and Nonlinear Dynamic Response
Authors: Yang Baozhong , Suh C. Steve
Published: December 2004

Spectral analysis has been widely applied to the detection of bifurcation and the determination of the extent to which dynamic instability and chaotic responses develop. However, because spectral analysis employs stationary sinusoids in representing time-varying signals of inherent nonlinearity, the use of Fourier domain methodologies would inexorably risk misinterpreting the true characteristics and obscuring the underlying physics of the nonlinear system being investigated. The fact that the amplitude and frequency of all the individual spectral component of a nonlinear, nonstationary dynamic response are modulated and coupled in time necessarily implies that, if the inception and transition of a bifurcated state of unstable motion is to be fully characterized, amplitude modulation and frequency modulation need to be temporally decoupled. The fundamental notion of instantaneous frequency defines frequency as the temporal gradient of phase and thus provides a powerful mechanism through which amplitude modulation and frequency modulation can be disassociated. Results of applying instantaneous frequency to the characterization of bifurcation and evolution of instability for a cracked rotor also indicate that instantaneous frequency interprets nonlinear rotary responses with sound physical bases.
Mechanotransduction by integrin is essential for IL-6 secretion from endothelial cells in response to uniaxial continuous stretch
Authors: Sasamoto Akitoshi , Nagino Masato , Kobayashi Satoshi , Naruse Keiji , Nimura Yuji , Sokabe Masahiro
Published: December 2004

We previously reported that uniaxial continuous stretch in human umbilical vein endothelial cells (HUVECs) induced interleukin-6 (IL-6) secretion via IκB kinase (IKK)/nuclear factor-κB (NF-κB) activation. The aim of the present study was to clarify the upstream signaling mechanism responsible for this phenomenon. Stretch-induced IKK activation and IL-6 secretion were inhibited by application of α5β1 integrin-inhibitory peptide (GRGDNP), phosphatidylinositol 3-kinase inhibitor (LY-294002), phospholipase C-γ inhibitor (U-73122), or protein kinase C inhibitor (H7). Although depletion of intra- or extracellular Ca2 + pool using thapsigargin (TG) or EGTA, respectively, showed little effect, a TG-EGTA mixture significantly inhibited stretch-induced IKK activation and IL-6 secretion. An increase in the intracellular Ca2 + concentration ([Ca2 +]i) upon continuous stretch was observed even in the presence of TG, EGTA, or GRGDNP, but not in a solution containing the TG-EGTA mixture, indicating that both integrin activation and [Ca2 +]i rise are crucial factors for stretch-induced IKK activation and after IL-6 secretion in HUVECs. Furthermore, while PKC activity was inhibited by the TG-EGTA mixture, GRGDNP, LY-294002, or U-73122, PLC-γ activity was retarded by GRGDNP or LY-294002. These results indicate that continuous stretch-induced IL-6 secretion in HUVECs depends on outside-in signaling via integrins followed by a PI3-K-PLC-γ-PKC-IKK-NF-κB signaling cascade. Another crucial factor, [Ca2 +]i increase, may at least be required to activate PKC needed for NF-κB activation.
Adipocytes with increased hexosamine flux exhibit insulin resistance, increased glucose uptake, and increased synthesis and storage of lipid
Authors: McClain Donald A. , Hazel Mark , Parker Glendon , Cooksey Robert C.
Published: December 2004

The hexosamine signaling pathway has been shown to serve a nutrient-sensing function. We have previously shown that overexpression of the rate-limiting enzyme for hexosamine synthesis (glutamine-fructose-6-phosphate amidotransferase) in adipose tissue of transgenic mice results in skeletal muscle insulin resistance and altered regulation of leptin and adiponectin. To dissect the pathways by which the hexosamine pathway affects fuel storage and energy homeostasis, we have examined the characteristics of adipocytes from these animals. After 3 mo of age, epididymal fat pads from adult transgenic animals are 42% heavier ( P = 0.003) and individual adipocytes are 23% larger in diameter ( P < 0.05) than those from littermate wild-type controls. Isolated adipocytes from transgenic mice are insulin resistant, with a 2.5-fold increase in the ED50for stimulation of 2-deoxy-d-glucose uptake. However, maximal insulin-stimulated glucose uptake is increased in transgenic adipocytes by 39% ( P < 0.05). This upregulation of glucose uptake was associated with a 41% increase in the expression of GLUT4 mRNA and a 28% increase in GLUT4 protein in transgenics compared with controls ( P < 0.05). GLUT1 mRNA and protein did not significantly differ between fasted control and transgenics. Total lipid synthesis was also increased in epididymal adipocytes from transgenic animals by 206% compared with controls ( P < 0.05). Fatty acid oxidation was increased 1.6-fold in the transgenic adipocytes ( P < 0.05). We conclude that the hexosamine signaling pathway upregulates fat storage in adipocytes in states of carbohydrate excess, in part by increasing GLUT4 and glucose uptake and by augmenting fatty acid synthesis.
Spinal P2X receptor modulates reflex pressor response to activation of muscle afferents
Authors: Gao Zhaohui , Kehoe Valerie , Sinoway Lawrence I. , Li Jianhua
Published: December 2004

Static contraction of skeletal muscle evokes increases in blood pressure and heart rate. Previous studies suggested that the dorsal horn of the spinal cord is the first synaptic site responsible for those cardiovascular responses. In this study, we examined the role of ATP-sensitive P2X receptors in the cardiovascular responses to contraction by microdialyzing the P2X receptor antagonist pyridoxal phosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS) into the L7 level of the dorsal horn of nine anesthetized cats. Contraction was elicited by electrical stimulation of the L7 and S1 ventral roots. Blockade of P2X receptor attenuated the contraction induced-pressor response [change in mean arterial pressure (ΔMAP): 16 ± 4 mmHg after 10 mM PPADS vs. 42 ± 8 mmHg in control; P < 0.05]. In addition, the pressor response to muscle stretch was also blunted by PPADS (ΔMAP: 27 ± 5 mmHg after PPADS vs. 49 ± 8 mmHg in control; P < 0.05). Finally, activation of P2X receptor by microdialyzing 0.5 mM α,β-methylene into the dorsal horn significantly augmented the pressor response to contraction. This effect was antagonized by prior PPADS dialysis. These data demonstrate that blockade of P2X receptors in the dorsal horn attenuates the pressor response to activation of muscle afferents and that stimulation of P2X receptors enhances the reflex response, indicating that P2X receptors play a role in mediating the muscle pressor reflex at the first synaptic site of this reflex.
Effects of isoprostane on tubuloglomerular feedback: roles of TP receptors, NOS, and salt intake
Authors: Welch William J.
Published: December 2004

A thromboxane prostanoid receptor (TP-R) agonist U-46,619 enhances tubuloglomerular feedback (TGF). Glomerular expression of TP-R and enhancement of TGF by U-46,619 increase with salt intake. We investigated the hypothesis that 8-isoprostaglandin F2α(8-Iso) activates TGF via TP-R. The maximal TGF response in rats was assessed from the fall in proximal stop flow pressure (PSF; an index of glomerular capillary pressure) during loop of Henle (LH) microperfusion of artificial tubular fluid (ATF) at 40 nl/min. Microperfusion of 8-Iso (10−4M) into the efferent arteriole (EA) enhanced TGF responses by 20 ± 3% ( P < 0.01). TGF response to 8-Iso was independent of dietary salt [ΔTGF%, low salt (LS): 21 ± 5%; normal salt (NS): 17 ± 4%; high salt (HS): 29 ± 8%, not significant (ns)], unlike the salt-dependent effect of U-46,619 (ΔTGF%, LS: 41 ± 5%; NS: 52 ± 4%; HS: 112 ± 21%). Ifetroban, the TP-R antagonist, abolished TGF responses to 8-Iso and U-46,619 at all levels of salt intake. During luminal perfusion of N-monomethyl-l-arginine (l-NMA), the effect of 8-Iso on TGF was enhanced in NS and HS but not in LS (LS: 22 ± 6 vs. LS + l-NMA: 28 ± 6%, ns; NS: 18 ± 4 vs. NS + l-NMA: 40 ± 4, P < 0.01; HS: 27 ± 3 vs. HS + l-NMA: 65 ± 6, P < 0.01). However, U-46,619 did not further increase TGF after l-NMA in all salt groups (LS: 43 ± 7 vs. LS + l-NMA: 51 ± 6, ns; NS: 52 ± 7 vs. NS + l-NMA: 48 ± 8, ns; HS: 114 ± 21 vs. HS + l-NMA: 74 ± 22, ns). In conclusion, activation of TP receptors by U-46,619 and 8-Iso-PGF2αenhances TGF. In addition, the effect of U-46,619 was salt dependent, whereas the effect of 8-Iso-PGF2αwas salt independent. However, stimulation of NO by 8-isoprostanes masks its salt-sensitive effect on TGF.
Extended Voluntary Running Inhibits Exercise-Induced Adult Hippocampal Progenitor Proliferation in the Spontaneously Hypertensive Rat
Authors: Naylor Andrew S. , Persson Anders I. , Eriksson Peter S. , Jonsdottir Ingibjörg H. , Thorlin Thorleif
Published: December 2004

Previous work has shown that voluntary running increases cell proliferation and neurogenesis in the dentate gyrus of the adult hippocampus. Here we report that long-term running for 24 days results in a down-regulation of hippocampal progenitor proliferation to one-half the level of nonrunning controls compared with a fivefold increase in progenitor proliferation seen after 9 days of voluntary running (short-term running). The negative effects seen on proliferation after 24 days of running were prevented by restricting daily running distances (by 30–50%) during 24 days. Long-term running for 24 days increases the response of the hypothalamic-pituitary-adrenal axis, with an increase in adrenal gland weight and increased plasma corticosterone levels, as well as decreased thymus weight, indicating a stress response as a possible mediator of decreased progenitor proliferation. Furthermore, the negative effects seen on the observed stress response after 24 days of running were prevented by restricting daily running distance. Short-term running did not alter these stress parameters compared with nonrunning controls. However, it increased phosphorylated cyclic AMP response element binding protein (pCREB) in the dentate gyrus, an increase that was not seen in nonrunning controls or after 24 days of running. Taken together, these data suggest that voluntary running does not always enhance proliferation and that the decrease in progenitor proliferation seen in long-term running is possibly mediated by mechanisms involving a stress response in the animal. However, a moderate level of long-term running was able to prevent the negative stress-related changes seen in unrestricted long-term running.
Validity and Reliability of a French Version of the MRF-28 Health-Related Quality of Life Questionnaire
Authors: Janssens Jean-Paul , Héritier-Praz Anne , Carone Mauro , Burdet Luc , Fitting Jean-William , Uldry Christophe , Tschopp Jean-Marie , Rochat Thierry
Published: December 2004

Background: Evaluation of health-related quality of life (HRQL) in chronic respiratory failure (CRF) is an important issue for evaluating the impact of treatment. Objectives: To elaborate a French version of the Maugeri Foundation Respiratory Failure Questionnaire (MRF-28) disease-specific HRQL questionnaire and determine its validity and reliability in patients with CRF treated by home mechanical ventilation (HMV). Methods: Forward- and back-translation of the MRF-28 questionnaire; the final version was submitted to 81 patients treated with HMV for CRF, simultaneously with the St. George’s Respiratory Questionnaire (SGRQ), the Short Form 36 (SF-36), and the Hospital Anxiety and Depression scale (HAD). Validity was determined by correlation with previously validated HRQL scores and recorded physiological parameters. Reliability was evaluated by assessing internal consistency and test-retest stability of the MRF-28 scores. Results: The French version of the MRF-28 and its subscores (‘daily activity’, ‘cognitive function’, and ‘invalidity’) were highly significantly correlated with subscores of the SGRQ, the SF-36 and the HAD. Both the MRF-28 and the SGRQ were correlated only with age and the 6-min walk test. The MRF-28 showed high test-retest reliability after 2 weeks (r2 = 0.80, p < 0.0001) and high internal consistency (Crohnbachs’ α coefficient: 0.91). Conclusion: The French version of the MRF-28 is a valid and reliable disease-specific questionnaire for assessing HRQL in patients with CRF.
Hevea brasiliensis Latex Allergens: Current Panel and Clinical Relevance
Authors: Wagner Stefan , Breiteneder Heimo
Published: December 2004

Latex allergy has been studied in detail in Europe and the US over the past two decades, resulting in specific guidelines that succeeded in reducing its incidence in high-risk populations within the medical field. How these developments have affected high-risk populations outside the health care scenario is an important unanswered question. In addition, a second wave of latex allergy may occur in nations that are striving to attain higher economic and technologic standards, including population-dense countries such as China. Therefore, the application of Hevea allergens in novel diagnostic assays and the development of specific latex immunotherapy will provide new opportunities for latex allergy research. In this review, we summarize current knowledge on the immunological properties of the 13 officially accepted Hevea brasiliensis latex allergens.
Regime Building as a Prime Mover of Technological Progress: The Energy Sector in the Central Asia-Caspian Region
Authors: Molchanov Mikhail , Yevdokimov Yuri
Published: December 2004

International political economy and global politics at large are increasingly driven by struggles over control of energy resources. The energy reserves of the Central Asia-Caspian region are fast becoming a focal point for these struggles. The exploration and development of oil and gas deposits can be realized in a variety of ways, some of which promote security and sustainability, while others open the gates for potential intrastate and interstate conflicts. Productivity growth and sustainable development can only be achieved on the basis of international cooperation that requires everyone to follow certain mutually agreeable "rules of the game." These rules, and the institutions that support them, should ideally form the backbone of an international governance structure that will promote not only peace and development, but also technological progress and social stability. This study demonstrates a connection between international politicaleconomic cooperation, on the one hand, and technological growth and social advancement of the region, on the other hand. It offers an analysis of the potential consequences of a cooperative regime for technological progress in the energy sector of the Central Asia-Caspian region. It shows that establishment of a cooperative energy regime in the region will lead to a technological breakthrough, as manifested by significant productivity growth, decreased unit cost of energy, and technological advancements in the energy sector itself and across the economy.
New Digital Technologies: Privacy/Property, Globalization, and Law
Authors: David Matthew , Kirkhope Jamieson
Published: December 2004

This paper addresses attempts to locate and dislocate music audiences in the context of global commercial, legal, and technical developments. The 2001 legal decision against Napster in the United States found the file share service company guilty of copyright infringement. This precedent appeared to support the recording industry. However, such legal frames have been bypassed by new softwares. Supporters see such global networks of sharing and distribution as undoing corporate control. The recording industry has responded with parallel claims of having encryption and surveillance technologies capable of globally reregulating property. However, as this article shows, there is no technical necessity and that total freedom and total enforcement are impossible. Just as globalization is reified into an inevitable process of deregulation in one instance and at the next moment it is reified into an indispensable regulatory regime, so new electronic media and global electronic networks promote neither regulation or deregulation, except in so far as the balance of social forces at any one time interprets and enacts them in such ways.
Cranial arterial foramen diameter in turtles: a quantitative assessment of size-independent phylogenetic signal
Authors: Jamniczky Heather , Russell Anthony
Published: December 2004

The study of turtle systematics has relied heavily on characters of the cranial circulation, particularly the internal carotid system, which is represented by canals and foramina in the bony skull. Comparison of cranial arteries and foramina has been qualitative; we undertake a quantitative reassessment of these features. We compare three methods of size removal from morphological data, and suggest methods by which size standardisation may be achieved in instances of incomplete preservation and statistically inadequate sample sizes. Further, we demonstrate that cranial arterial foramina provide a reliable estimate of vessel size, and conclude that the internal carotid system varies quantitatively, significantly and consistently among turtle clades, in a fashion which allows predictions to be made about phylogenetic relationships.
The Value of Wind Profiler Data in U.S. Weather Forecasting
Authors: Benjamin Stanley G. , Schwartz Barry E. , Szoke Edward J. , Koch Steven E.
Published: December 2004

An assessment of the value of data from the NOAA Profiler Network (NPN) on weather forecasting is presented. A series of experiments was conducted using the Rapid Update Cycle (RUC) model/assimilation system in which various data sources were denied in order to assess the relative importance of the profiler data for short-range wind forecasts. Average verification statistics from a 13-day cold-season test period indicate that the profiler data have a positive impact on short-range (3–12 h) forecasts over the RUC domain containing the lower 48 United States, which are strongest at the 3-h projection over a central U.S. subdomain that includes most of the profiler sites, as well as downwind of the profiler observations over the eastern United States. Overall, profiler data reduce wind forecast errors at all levels from 850 to 150 hPa, especially below 300 hPa where there are relatively few automated aircraft observations. At night when fewer commercial aircraft are flying, profiler data also contribute strongly to more accurate 3-h forecasts, including near-tropopause maximum wind levels. For the test period, the profiler data contributed up to 20%–30% (at 700 hPa) of the overall reduction of 3-h wind forecast error by all data sources combined. Inclusion of wind profiler data also reduced 3-h errors for height, relative humidity, and temperature by 5%-15%, averaged over different vertical levels. Time series and statistics from large-error events demonstrate that the impact of profiler data may be much larger in peak error situations.

Three data assimilation case studies from cold and warm seasons are presented that illustrate the value of the profiler observations for improving weather forecasts. The first case study indicates that inclusion of profiler data in the RUC model runs for the 3 May 1999 Oklahoma tornado outbreak improved model guidance of convective available potential energy (CAPE), 300-hPa wind, and precipitation in southwestern Oklahoma at the onset of the event. In the second case study, inclusion of profiler data led to better RUC precipitation forecasts associated with a severe snow and ice storm that occurred over the central plains of the United States in February 2001. A third case study describes the effect of profiler data for a tornado event in Oklahoma on 8 May 2003. Summaries of National Weather Service (NWS) forecaster use of profiler data in daily operations, although subjective, support the results from these case studies and the statistical forecast model impact study in the broad sense that profiler data contribute significantly to improved short-range forecasts over the central United States where these observations currently exist.
Longitudinal Invariance of the Center for Epidemiologic Studies-Depression Scale among Girls and Boys in Middle School
Authors: Motl Robert W. , Dishman Rod K. , Birnbaum Amanda S. , Lytle Leslie A.
Published: December 2004

This study tested the longitudinal factorial invariance of a theoretically consistent, higher-order model for Center for Epidemiologic Studies-Depression (CES-D) scores among adolescent girls and boys in middle school. Data were collected from 2,416 adolescents who completed a survey containing the CES-D in the fall of 1998, spring of 1999, and spring of 2000. The invariance analyses were conducted using LISREL 8.50 with maximum likelihood estimation and the Satorra-Bentler scaled chi-square statistic and standard errors. The higher-order model demonstrated longitudinal, as well as gender, invariance of the overall factor structure and first- and second-order structure coefficients, first-order factor variances, second-order factor variances and covariances, and item uniquenesses. The results demonstrate that meaningful comparisons of composite CES-D scores can be made across time among girls and boys in middle school.
Juvenile Sex Offenders: A Group on its Own?
Authors: van Wijk Anton , van Horn Joan , Bullens Ruud , Bijleveld Catrien , Doreleijers Theo
Published: December 2004

There is some debate about whether sex offenders are similar to non-sex offenders. It is known that sex and non-sex offenders are heterogeneous groups. Comparative studies must take this heterogeneity into account. Based on an aggregated database, a study was conducted among adjudicated juvenile (sex) offenders. The sample consisted of juvenile male sex and non-sex offenders who had been subjected to a psychological assessment at the request of the judge or district attorney. The central question focused on the differences between juvenile sex offenders, in particular rapists and sexual assaulters (n = 57), child molesters (n= 55), and non-sex offenders: violent (n = 85) and nonviolent offenders (n = 80). The results demonstrated that sex offenders differ from non-sex offenders with regard to demographic characteristics, problem behavior, and personality traits. Some reference is made regarding future research.
Successful treatment of severe bleeding in hemophilic target joints by selective angiographic embolization
Authors: Mauser-Bunschoten Eveline P. , Zijl Jacco A. C. , Mali Willem , van Rinsum A. Cees , van den Berg H. Marijke , Roosendaal Goris
Published: December 2004

Bleeding into the joints is common in patients with hemophilia. After total knee or elbow replacement, profuse intraarticular bleeding unresponsive to high-dose clotting factor replacement sometimes occurs. In some patients who have severely damaged elbow or knee joints the same profuse bleeding pattern can be seen. To control bleeding in these patients, selective catheterization with a microcatheter and therapeutic embolization with microcoils was performed whenever a severe blush or microaneurysm was observed on angiography. Over 12 years, in 23 cases of massive joint bleeding in 18 patients with hemophilia selective catheterization was performed. In 15 cases the bleeding was postoperative and in 8 spontaneous. Results of angiographic imaging revealed vascular blush, false aneurysm, true aneurysm, and arteriovenous shunt in combination with an aneurysm as cause of bleeding. In 2 patients, the cause of bleeding was not found. In 21 cases an embolization procedure was performed, in which the bleeding was completely controlled by a single procedure in 14 cases. Recurrence of the bleeding occurred in 7 cases and required a second embolization procedure; in one patient even a third embolization was required to stop the bleeding completely. No difference in the outcome, that is, clinical end of bleeding and joint range of motion, was observed, when comparing postoperative and spontaneous bleeding.
G2 damage checkpoints: what is the turn-on?
Authors: O'Connell Matthew J. , Cimprich Karlene A.
Published: December 2004

Cells mount a coordinated response to DNA damage, activating DNA repair pathways and cell-cycle checkpoint pathways to allow time for DNA repair to occur. In human cells, checkpoint responses can be divided into p53-dependent and p53-independent pathways, the latter being predominant in G2 phase of the cell cycle. The p53-independent pathway involves a phosphorylation cascade that activates the Chk1 effector kinase and induces G2 arrest through inhibitory tyrosine phosphorylation of Cdc2. At the top of this cascade are the ATR and ATM kinases. How ATM and ATR recognize DNA damage and activate this checkpoint pathway is only beginning to emerge. Single-stranded DNA, a result of stalled DNA replication or processing of chromosomal lesions, appears to be central to the activation of ATR. The recruitment of replication protein A to single-stranded DNA facilitates the recruitment of several complexes of checkpoint proteins. In this context, ATR is activated and then phosphorylates the C-terminus of Chk1, activating it to enforce a block to mitotic entry.
Cofilin takes the lead
Authors: DesMarais Vera , Ghosh Mousumi , Eddy Robert , Condeelis John
Published: December 2004

Cofilin has emerged as a key regulator of actin dynamics at the leading edge of motile cells. Through its actin-severing activity, it creates new actin barbed ends for polymerization and also depolymerizes old actin filaments. Its function is tightly regulated in the cell. Spatially, its activity is restricted by other actin-binding proteins, such as tropomyosin, which compete for accessibility of actin filament populations in different regions of the cell. At the molecular level, it is regulated by phosphorylation, pH and phosphatidylinositol (4,5)-bisphosphate binding downstream of signaling cascades. In addition, it also appears to be regulated by interactions with 14-3-3ζ and cyclase-associated protein. In vivo, cofilin acts synergistically with the Arp2/3 complex to amplify local actin polymerization responses upon cell stimulation, which gives it a central role in setting the direction of motility in crawling cells.
One-step Synthesis of Single-crystalline CdSe Nanorods via γ-Ray Irradiation
Authors: Zhao Qingchun , Chen Wenming , Zhu Qingren
Published: December 2004

High aspect ratio single-crystalline CdSe micrometer rods with a uniform and smooth surface texture are synthesized via γ-ray irradiation at 170 °C. The length of the rods and the diameter of the CdSe micrometer rods are about tens micron and 240–300 nm, respectively.
Alternative splicing induced by nonsense mutations in the immunoglobulin μ VDJ exon is independent of truncation of the open reading frame
Authors: BÜHLER MARC , MÜHLEMANN OLIVER
Published: December 2004

In addition to triggering nonsense-mediated mRNA decay (NMD), premature translation-termination codons (PTCs) frequently induce alternative splicing, an observation referred to as nonsense-associated alternative splicing (NAS). In many cases, NAS is induced because the nonsense mutation alters a splicing signal, such as inactivating an exonic splicing enhancer. However, for a few genes, NAS was reported to be PTC specific, implying that a translation signal could influence splicing. Here, we investigated whether production of a previously undetected alternatively spliced transcript from immunoglobulin μ (Ig-μ) depends on premature termination of the open reading frame. We show that PTCs at different positions in the VDJ exon of an Ig-μ minigene activate usage of an alternative 3′ splice site, generating an alternative transcript that lacks the initial PTC and a previously identified NMD-promoting element (NPE), but contains new PTCs because of a frame shift. Corroborating the importance of the NPE for maximal NMD response, the alternative transcript is only moderately down-regulated by NMD. We further demonstrate that NAS of Ig-μ minigene transcripts is not PTC specific. This finding, together with our results that contradict the previously reported frame dependence of TCR-β NAS, challenges the idea that cells might possess mechanisms that would allow regulation of splice site selection in response to premature termination of the ORF.
Cardiac Troponin I Concentrations, but Not Electrocardiographic Results, Predict an Extended Hospital Stay after Coronary Artery Bypass Graft Surgery
Authors: Salamonsen Robert F , Schneider Hans-Gerhard , Bailey Michael , Taylor Andrew J
Published: December 2004

Background: Cardiac damage in coronary artery graft (CABG) surgery is an important contributor to postoperative cardiac dysfunction and delayed hospital discharge. Currently, no simple method exists for its quantification.

Methods: In a prospective study of 300 patients having routine CABG surgery, we compared cardiac troponin I (cTnI) concentrations at 6 and 24 h after surgery with electrocardiographic (ECG) results as predictors of an extended postoperative stay in the intensive care unit (ICU) and in the hospital. We stratified outcome variables by tertiles of cTnI concentration and studied the significance of differences between outcome variables across tertiles.

Results: Multivariate analysis showed that 24-h cTnI is a significant predictor of increased postoperative ICU stay (P = 0.012) and postoperative hospital stay (P = 0.024). For 6-h cTnI, corresponding significance values were P = 0.29 and 0.9. ECG was of no value (P = 0.39 and 0.47). Differences in 24-h cTnI were highly significant, particularly for lowest vs highest tertiles, and allowed stratification of risk into “low” (<10 μg/L), “equivocal” (10–20 μg/L), and “high” (>20 μg/L).

Conclusions: Use of a single 24-h cTnI value to quantify perioperative myocardial damage identifies patients who are at greater risk of extended ICU and hospital stays. This strategy could assist in allocation of patients to different management streams after CABG surgery.
Hot-pressing stress graded aspen veneer for laminated veneer lumber (LVL)
Authors: Wang Brad Jianhe , Dai Chunping
Published: December 2004

Aspen (Populus tremuloides) is emerging as an important species for laminated veneer lumber (LVL) products in North America. During LVL manufacturing, both veneer stress grades and hot-pressing schedules are vital to product performance. In this study, an experimental design with four three-level variables comprising veneer moisture content (MC), veneer stress grade, platen pressure, and glue spread level was employed to investigate their effects on pressing behavior and stiffness and strength properties of LVL panels. The results show that, within the ranges studied, glue spread level and platen pressure were the two most important variables affecting the hot-pressing time needed for the innermost glueline to reach a target temperature of 105°C. The MC from the glue (mainly in the glueline) affected the rise of the innermost temperature more significantly than the MC in the veneer. Among the four variables studied, veneer stress grade and veneer MC were the two dominant variables that affect LVL stiffness and strength properties. Flat-wise and edge-wise bending stiffness (MOE) and strength (MOR) of LVL panels made from higher stress grade veneers were higher compared to those made from lower stress grade veneers, but there was no direct correlation between LVL shear strength and veneer stress grade. In addition, LVL edge-wise bending stiffness had the highest veneer MC tolerance among all LVL stiffness and strength properties. Further, LVL stiffness enhancement (the ratio of LVL MOE over veneer MOE) was lower with higher stress grade veneers than with lower stress grade veneers. These findings are useful for manufacturing high-stiffness LVL for engineered applications.
Bioactive phenolic substances in important tree species. Part 3: Knots and stemwood of Acacia crassicarpa and A. mangium
Authors: Pietarinen Suvi P. , Willför Stefan M. , Sjöholm Rainer E. , Holmbom Bjarne R.
Published: December 2004

Polyphenols in heartwood, sapwood, and knots of Acacia crassicarpa and Acacia mangium were analysed using GC, GC-MS, HPSEC, and NMR. Melacacidin and isomelacacidin dominated in A. crassicarpa and teracacidin and its ketone in A. mangium. Also, bi- and triflavonoids were tentatively identified in the samples. The amounts of polyphenols were larger in the knots than in the heartwood of both species, while the composition within the species was the same.
Aspects of Early Hominid Sociality: an Evolutionary Perspective
Authors: Clark G.A.
Published: December 2004

Despite nominal acknowledgment, archaeologists have been slow to take advantage of neo‐Darwinian evolutionary theory (NDT) in the course of their research. While perhaps understandable for those working in later prehistory, where quasi‐historical explanations for process can sometimes be invoked, archaeologists working in ‘deep time’ have also shown a marked reluctance to use it. This essay asks why this is so, and goes on to apply NDT concepts in an effort to reconstruct aspects of early hominid sociality. Local group size and composition, sex‐based dispersal at maturity, sexual selection and mating practices, kinship, enculturation, primate cognitive abilities and the social context of learning are addressed using an eclectic approach in which non‐human primate data, sociological data on modern human mating practices and human paleontology play important roles.