bluuebunny/crossref_metadata_2025_split huggingface dataset:
Why add anything to nothing? The arcsine difference as a measure of treatment effect in meta‐analysis with zero cells
Authors: Rücker Gerta , Schwarzer Guido , Carpenter James , Olkin Ingram 
Published: December 2008

AbstractFor clinical trials with binary endpoints there are a variety of effect measures, for example risk difference, risk ratio and odds ratio (OR). The choice of metric is not always straightforward and should reflect the clinical question. Additional issues arise if the event of interest is rare. In systematic reviews, trials with zero events in both arms are encountered and often excluded from the meta‐analysis.The arcsine difference (AS) is a measure which is rarely considered in the medical literature. It appears to have considerable promise, because it handles zeros naturally, and its asymptotic variance does not depend on the event probability.This paper investigates the pros and cons of using the AS as a measure of intervention effect. We give a pictorial representation of its meaning and explore its properties in relation to other measures. Based on analytical calculation of the variance of the arcsine transformation, a more conservative variance estimate for the rare event setting is proposed. Motivated by a published meta‐analysis in cardiac surgery, we examine the statistical properties of the various metrics in the rare event setting.We find the variance estimate of the AS to be more stable than that of the log‐OR, even if events are rare. However, parameter estimation is biased if the groups are markedly unbalanced. Though, from a theoretical viewpoint, the AS is a natural choice, its practical use is likely to continue to be limited by its less direct interpretation. Copyright © 2008 John Wiley & Sons, Ltd.
Extending the skill test for disease diagnosis
Authors: Lin Shu‐Chuan , Kvam Paul H. , Lu Jye‐Chyi 
Published: December 2008

AbstractFor diagnostic tests, we present an extension to the skill plot introduced by Briggs and Zaretski (Biometrics2008;64:250–261). The method is motivated by diagnostic measures for osteopetrosis in a study summarized by Hanset al.(The Lancet1996;348:511–514). Diagnostic test accuracy is typically defined using the area (or partial area) under the receiver operator characteristic (ROC) curve. If partial area is used, the resulting statistic can be highly subjective because the focus region of the ROC curve corresponds to a set of low false‐positive rates that are chosen by the experimenter. This paper introduces a more objective diagnostic test for which the focus region depends on a skill score, which in turn depends on the loss functions associated with misdiagnosis. More specifically, the skill‐based diagnostic test serves as a more objective version of the nonparametric test introduced by Dodd and Pepe (Biometrics2003;59:614–623). Copyright © 2008 John Wiley & Sons, Ltd.
Aspect‐oriented component assembly—a case study in parallel software design
Authors: Dangelmayr C. , Blochinger W. 
Published: December 2008

AbstractIn this paper we deal with building parallel programs based on sequential application code and generic components providing specific functionality for parallelization, like load balancing or fault tolerance. We describe an architectural approach employing aspect‐oriented programming to assemble arbitrary object‐oriented components. Several non‐trivial crosscutting concerns arising from parallelization are addressed in the light of different applications, which are representative of the most common types of parallelism. In particular, we demonstrate how aspect‐oriented techniques allow us to leave all existing code untouched. We evaluate and compare our approach with its counterparts in conventional object‐oriented programming. Copyright © 2008 John Wiley & Sons, Ltd.
A study on aggregation of group decisions
Authors: Huang Yeu‐Shiang , Liao Jing‐Tai , Lin Zu‐Liang 
Published: December 2008

AbstractThe analytic hierarchy process (AHP), proposed by Saaty in 1971, has already become a common decision technique in the field of decision science. In attempting to deal with group decision problems, a vast amount of literature has adopted geometric means or arithmetic means to aggregate the multiple opinions of group decision makers with AHP. However, geometric means and arithmetic means are usually subject to the influence of extreme values, and make use of only simple average types of manipulation to combine the judgments of decision makers which may not practically capture the group preferences among alternatives. In this paper, two aspects of consideration are probed into the construction of a group AHP decision model, which are ‘preferential differences’ to denote the differences of preferential weights among alternatives for each decision maker, and ‘preferential ranks’ to denote the ranks of the alternatives for each decision maker. A comparative analysis is performed to investigate the effectiveness of the proposed model, and a ‘satisfaction index’ is suggested to indicate the satisfactory level of the final obtained group decision. Finally, a feedback interview is carried out to collect the post‐model opinions of decision makers in order to understand their acceptance about the proposed model. Copyright © 2008 John Wiley & Sons, Ltd.
Amyloid β‐protein fragments 25–35 and 31–35 potentiate long‐term depression in hippocampal CA1 region of rats in vivo
Authors: Cheng Li , Yin Wen‐Juan , Zhang Jun‐Fang , Qi Jin‐Shun 
Published: December 2008

AbstractAmyloid β‐protein (Aβ) is thought to be responsible for the deficit of learning and memory in Alzheimer's disease (AD), possibly through interfering with synaptic plasticity in the brain. It has been reported that Aβ fragments suppress the long‐term potentiation (LTP) of synaptic transmission. However, it is unclear whether Aβ fragments can regulate long‐term depression (LTD), an equally important form of synaptic plasticity in the brain. The present study investigates the effects of Aβ fragments on LTD induced by low frequency stimulation (LFS) in the hippocampus in vivo. Our results showed that (1) prolonged 1–10 Hz of LFS all effectively elicited LTD, which could persist for at least 2 h and be reversed by high frequency stimulation (HFS); (2) the effectiveness of LTD induction depended mainly on the number of pulses but not the frequency of LFS; (3) pretreatment with Aβ fragment 25–35 (Aβ25–35, 12.5 and 25 nmol) did not change baseline field excitatory postsynaptic potentials but dose‐dependently potentiated LTD; (4) Aβ fragment 31–35 (Aβ31–35), a shorter Aβ fragment than Aβ25–35, also dose‐dependently strengthened LFS‐induced hippocampal LTD. Thus, the present study demonstrates the enhancement of hippocampal LTD by Aβ in in vivo condition. We propose that Aβ‐induced potentiation of LTD, together with the suppression of LTP, will result in the impairment of cognitive function of the brain. Synapse 63:206–214, 2009. © 2008 Wiley‐Liss, Inc.
Facilitation of glutamate release from rat cerebrocortical glutamatergic nerve terminals (synaptosomes) by phosphatidylserine and phosphatidylcholine
Authors: Yang Tsung‐Tsair , Wang Su‐Jane 
Published: December 2008

AbstractPhosphatidylserine (PS) and phosphatidylcholine (PC) have been shown to enhance cognitive function. Considering that brain glutamatergic system is thought to participate in cognitive processing, our objective was to determine the effect of PS and PC on glutamate release from the nerve terminal (synaptosome) freshly isolated from rat cerebral cortex. Data showed that both PS and PC potently facilitate 4‐aminopyridine (4‐AP)‐evoked Ca2+‐dependent and Ca2+‐independent glutamate release. Facilitation of glutamate release by PS or PC was associated with an increase of 4‐AP‐evoked depolarization and downstream elevation of cytoplasmic free calcium concentration ([Ca2+]c). In addition, glutamate release elicited by direct Ca2+‐entry with Ca2+‐ionophore (ionomycin) was also facilitated by PS or PC. Furthermore, PS‐ or PC‐mediated facilitation of 4‐AP‐evoked glutamate release was superseded or suppressed by protein kinase C (PKC) activator and inhibitor, respectively. Together, these results suggest that PS or PC effects a facilitation of glutamate exocytosis by increasing nerve terminal excitability and Ca2+influx into cerebrocortical nerve terminals through a signaling cascade involving PKC. Synapse 63:215–223, 2009. © 2008 Wiley‐Liss, Inc.
Changes in the thiamine and riboflavin contents of rice during artisanal parboiling in Ghana
Authors: Manful JT , Swetman AA , Coker RD , Drunis A 
Published: December 2008

AbstractRice samples mildly parboiled at various combinations of soaking temperatures and steaming times were analysed for their thiamine and riboflavin contents. The relative parboiling index was calculated and this provided a reliable measure of the overall effects of different conditions on the degree of parboiling. The thiamine content of parboiled rice samples increased gradually as parboiling intensity was increased from initial soaking temperature at 30°C and steaming for 4 min to soaking at 70°C and steaming for 12 min. There was a sharper rise in thiamine when the soaking temperature was increased to 90°C, and the sample that was steamed for 12 min after soaking at 90°C had a thiamine content of 0.612 µg g−1. The level of riboflavin also initially increased with parboiling, but it peaked at 0.278 µg g−1 in the sample that was soaked at 70°C and steamed for 12 min, and then decreased as parboiling intensity was increased further. The commercially parboiled rice sample had a riboflavin content of 0.206 µg g−1. This pattern of change in riboflavin levels with parboiling was probably due to thermal breakdown of the vitamin at higher soaking temperature. Copyright © 2008 John Wiley & Sons, Ltd
Timing of mid‐trimester cervical length shortening in high‐risk women
Authors: Szychowski J. M. , Owen J. , Hankins G. , Iams J. , Sheffield J. , Perez‐Delboy A. , Berghella V. , Wing D. A. , Guzman E. R. 
Published: December 2008

AbstractObjectiveTo examine the natural history of cervical length shortening in women who had experienced at least one prior spontaneous preterm birth at between 17 + 0 and 33 + 6 weeks' gestation.MethodsThis was an analysis of prerandomization data from the multicenter Vaginal Ultrasound Cerclage Trial. Serial cervical length was measured by transvaginal sonography in 1014 high‐risk women at 16 + 0 to 22 + 6 weeks. We performed survival analyses in which the outcome was cervical length shortening < 25 mm and data were censored if this did not occur before 22 + 6 weeks' gestation. The incidence of cervical length shortening and the time to shortening were compared for women whose earliest prior preterm birth was in the mid‐trimester, defined as < 24 weeks, vs. those at weeks 24–33. Similar comparisons were performed based on each patient's most recent birth history.ResultsTime to cervical length shortening by survival analysis was significantly shorter (hazard ratio (HR) = 2.2, P < 0.0001) and the relative risk (RR) of shortening significantly higher (RR = 1.8, P < 0.0001) for women whose earliest prior spontaneous preterm birth was at < 24 weeks. A larger effect was observed for women whose most recent birth was at < 24 weeks (HR = 2.8, P < 0.0001; RR = 2.1, P < 0.0001). The observed hazard ratios remained significant after adjusting for confounders in a multivariable Cox proportional hazards model.ConclusionWomen with a prior spontaneous preterm birth at < 24 weeks are at a higher risk of cervical shortening, and do so at a higher rate and at an earlier gestational age, than do women with a later preterm birth history. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Sonographic features of primary ovarian fibrosarcoma: a report of two cases
Authors: Testa A. C. , Gaurilcikas A. , Licameli A. , Mancari R. , Di Legge A. , Malaggese M. , Mascilini F. , Zannoni G. F. , Scambia G. , Ferrandina G. 
Published: December 2008

AbstractTwo cases of primary cellular fibroblastic tumor of the ovary are described, which presented a challenging clinical and histopathological differential diagnosis of primary ovarian fibrosarcoma and mitotically active cellular fibroma. On sonographic evaluation they both appeared as solid lesions with irregular margins, and on histological analysis both showed a count of 5–7 mitotic figures per 10 high‐power fields. Histopathological examination of the first case was characterized by the presence of hemorrhage, necrosis and severe nuclear atypia, with a metastatic peritoneal lesion, and the eventual diagnosis was primary ovarian fibrosarcoma. The second case, however, was diagnosed as a ‘mitotically active cellular fibroma’ owing to the lack of substantial severe cellular atypia, hemorrhage or necrosis. We speculate that ovarian fibrosarcoma at the preoperative examination might be considered in the differential diagnosis whenever a unilateral, heterogeneous, largely round solid ovarian lesion is detected. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
A novel task scheduling algorithm based on dynamic critical path and effective duplication for pervasive computing environment
Authors: Luo Junzhou , Dong Fang , Cao Jiuxin , Song Aibo 
Published: December 2008

AbstractIn order to effectively utilize massive heterogeneous resources and provide transparent computing capability to upper applications, task scheduling as the key issue of pervasive computing system becomes significantly important. Previous proposed priority and duplication based task scheduling algorithms, which can be applied in pervasive computing environment, usually have following limitations: critical path cannot be calculated accurately while neglecting the effect of resource availability in scheduling; in duplication based resource allocation stage, duplications without restriction would lead to some negative effects on final schedule length (SL). For the purpose of solving these problems, a novel task scheduling algorithm based on dynamic critical path (DCP) and effective duplication, called DCPED, is presented in this paper. In DCPED, a more accurate DCP calculation method which takes resource availability into account is introduced. Meanwhile an effective task duplication strategy is proposed to eliminate ineffective duplications and make an optimized schedule result by using space compression technique and dynamic critical path length (DCPL) based evaluation technique respectively. Finally, simulation results show that DCPED can outperform previous algorithms significantly in NSL and speedup rate metrics. Especially, it is very effective for utilizing computing resources and scheduling the fine‐grain and large‐scale workflow applications in pervasive computing system. Copyright © 2008 John Wiley & Sons, Ltd.
Channel estimation joint DOAs and time delay correlation in TD‐SCDMA mobile radio systems
Authors: Luo Zhinian , Zhang Wenjun , Xu Youyun 
Published: December 2008

AbstractAn improved channel estimation technique based on the Steiner low‐cost channel estimator is proposed, which is widely used in TD‐SCDMA (Time Division‐Synchronous Code Division Multiple Access) cellular mobile radio systems. TD‐SCDMA is also known as third‐generation mobile systems where adaptive antennas are employed. As additive noise has a great adverse effect on the performance of the Steiner estimator, the proposed method employs time‐correlated post‐processing with a threshold filter to reduce channel noise and compensate channel variations. Furthermore, channel estimation combining direction‐of‐arrivals (DOAs) is performed, which can reduce channel interferences without adding computational complexity, for the information of DOAs has been obtained by the inherent adaptive antenna system. The performance of the improved channel estimator is compared with conventional channel estimation approaches, and numerical results show that the new approach can lead to considerable performance enhancement even in high‐speed vehicle propagation environments. Copyright © 2008 John Wiley & Sons, Ltd.
Joint optimization of power scheduling and rate‐distortion performance inone‐helperproblem
Authors: Behroozi Hamid , Soleymani M. Reza 
Published: December 2008

AbstractWe consider themany‐help‐oneproblem, also calledm‐helperproblem, for the special case ofm = 1 where one source provides partial side information to the fusion center (FC) to help reconstruction of the other correlated source. Both correlated sources communicate information about their observations to the FC through an orthogonal multiple access channel (MAC) without cooperating with each other. First, we characterize the optimal tradeoff between the transmission cost, that is, power, and the distortion D. Then, we consider a joint optimization of source coding and power scheduling from an information theory perspective, where the power scheduling is verified using Shannon capacity formula and the source‐coding problem is analyzed using rate‐distortion theory. We show that the joint optimization in the Gaussianone‐helperproblem can be solved analytically. We provide closed‐form expressions for the optimal distortion and the optimal power scheduling in terms of the cost weights. Copyright © 2008 John Wiley & Sons, Ltd.
A New Transition Metal Tetracyanidoborate: Synthesis, Structure and Properties of Co[B(CN)4]2·2H2O
Authors: Nitschke Christian , Köckerling Martin 
Published: December 2008

AbstractThe reaction of tetracyanidoboronic acid, H[B(CN)4], with CoCO3 or Co(OH)2 in aqueous solution leads after slow evaporation of water to single crystals of Co[B(CN)4]2·2H2O. The compound has been characterized by single crystal X‐ray diffraction ($I {\bar 4} \mathit{2}d$, a = 12.2922(9), c = 9.2235(7) Å, Z = 4). The Co2+ ion is octahedrally coordinated by four nitrogen atoms of four different tetracyanidoborate CN groups occupying the four equatorial positions and two molecules of water occupying the remaining corners of the octahedron. The single crystal X‐ray structure, the vibrational spectra, and the thermal properties are compared with other known tetracyanidoborates with divalent cations.
Synthesis and X‐ray Crystal Structure of Bis[oxamide dioximato‐κ2N,N′](oxamide dioxime‐κ2N,N′)cobalt(III) Perchlorate Hexahydrate
Authors: Bélombé Michel M. , Nenwa Justin , Lönnecke Peter , Hey‐Hawkins Evamarie 
Published: December 2008

AbstractCo(OAc)2 reacts with oxamide dioxime (H2oxado) in water in the presence of ClO4– ions to produce [Co(Hoxado)2(H2oxado)]ClO4·6H2O (1), where Hoxado– is the anion of H2oxado, derived from the deprotonation of one of the two hydroximinic groups, and in which oxidation of CoII to CoIII (in air) had occurred. 1 is the first example of a salt in which the cation, [Co(H2oxado)3]3+, is doubly deprotonated to generate the chiral cation, [Co(Hoxado)2(H2oxado)]+. The central cobalt cation is pseudo‐octahedrally coordinated by six nitrogen atoms. In the solid state, the complex cations form centro‐symmetric dimers via O–H···O bridges. The bulk structure is consolidated by an extended three‐dimensional network of O–H···O and N–H···O bridges that interconnect the ionic constituents and the water molecules.
Structural Variety in the Pseudo‐ternary System M/Ge/I:;alpha;‐[NMe(nBu)3](GeI4)I, β‐[NMe(nBu)3](GeI4)I and [ImMe(nBu)][N(nBu)4](GeI4)3I2
Authors: Wolff Michael , Feldmann Claus 
Published: December 2008

AbstractBy reaction of GeI4, [N(nBu)4]I as iodide donor, and [NMe(nBu)3][N(Tf)2] as ionic liquid, reddish‐black, plate‐like shaped crystals are obtained. X‐ray diffraction analysis of single crystals resulted in the compositions ;alpha;‐[NMe(nBu)3](GeI4)I (Pbca; a = 1495.4(3) pm; b = 1940.6(4) pm; c = 3643.2(7) pm; Z = 16) and β‐[NMe(nBu)3](GeI4)I (Pn; a = 1141.5(2) pm; b = 953.6(2) pm; c = 1208.9(2) pm; β = 100.8(1)°; Z = 2). Depending on the reaction temperature, the one or other compound is formed selectively. In addition, the reaction of GeI4 and [N(nBu)4]I, using [ImMe(nBu)][BF4] (Im = imidazole) as ionic liquid, resulted in the crystallization of [ImMe(nBu)][N(nBu)4](GeI4)3I2 (P21/c; a = 1641.2(3) pm; b = 1903.0(4) pm; c = 1867.7(4) pm; β = 92.0(1)°; Z = 4). The anionic network of all three compounds is established by molecular germanium(IV)iodide, which is bridged by iodide anions. The different connectivity of (GeI4–I–) networks is attributed to the flexibility of I– regarding its coordination and bond length. Here, a [3+1]‐, 4‐ and 5‐fold coordination is first observed in the pseudo‐ternary system M/Ge/I (M: cation).
Pb5I2P28, $^{1}_{\infty}\rm [PbP_{14}]{\rm ^{2-}}$ Strands Coordinated to a Unique [Pb3I2]4+ Unit
Authors: Bawohl Melanie , Nilges Tom 
Published: December 2008

AbstractPb5I2P28 is the first compound containing a former unseen [P3I2]4+ unit, connecting two crystallographically independent adjacent [PbP14]2− polyphosphide strands. The polyanion substructure is closely related to the one realized in the HgPbP14 structure type, with a homo‐nuclear coordination of the cations to the polyanions. It has been prepared by using the mineralizator concept for polyphosphides from the elements and PbI2 as the mineralizator species. The new polyphosphide has a pronounced tendency to form easy cleavable, needle shaped crystals featuring massive stacking vaults. Nevertheless, a single crystal structure determination was possible from inter‐grown crystals. Pb5I2P28 crystallizes monoclinically in the space group P21/n (No. 14) with lattice parameters of a = 9.792(2), b = 17.717(2), c = 19.191(3) Å, β = 96.39(1)°, V = 3308.6(8) Å3. Depending on the preparation route, the aspect ratio of the needle shaped crystals can be varied.
Functionalised Tris(pyrazolyl)methane Ligands and Re(CO)3 Complexes Thereof
Authors: Kunz Peter C. , Berghahn Michael , Brückmann Nadine E. , Dickmeis Marcus , Kettel Markus , Spingler Bernhard 
Published: December 2008

AbstractThe synthesis of new tripodal nitrogen ligands derived from tris(pyrazolyl)methane (TpmR, R = H, tBu, Ph in 3‐position) is described. After deprotonation of the parent tris(pyrazolyl)methane TpmR, the carbanion reacts readily with ethylene oxide to yield the 3,3,3‐tris(3′‐substituted pyrazolyl)propanol ligands[(3‐Rpz)3CCH2CH2OH, R = H, tBu, Ph, 1a–c]. These ligands can be easily derivatised at the alcohol function. Microwave‐assisted reactions of these ligands and [Re(CO)5Br] yields the complex [(1a)Re(CO)3]Br (4) in the case of ligand 1a, whereas in the case of the substituted ligands 1b and 1c degradation was observed. The degradation products are identified as [(HpzR)2Re(CO)3Br] [R = tBu (7b), Ph (7c)]. These complexes were also prepared directly from [Re(CO)5Br] and the corresponding pyrazoles by microwave‐assisted synthesis. The Re(CO)3 complexes 4 and [(1a)Re(CO)3]OTf (5) are water‐soluble. The structures of 5·H2O and [{(pz)3CCH2CH3}Re(CO)3]OTf·1.5H2O·1/2CH3CN (6·1.5H2O·1/2CH3CN) as well as the structure of 7b have been elucidated by X‐ray crystallography.
Crystal Structure and Magnetic Properties of Copper(II) and Nickel(II) Binuclear Complexes with Bisacylhydrazones Based on 2,6‐Diformyl‐4‐methylphenol
Authors: Tupolova Yuliya P. , Popov Leonid D. , Lukov Vladimir V. , Shcherbakov Igor N. , Levchenkov Sergey I. , Kogan Victor A. , Maevskiy Oleg V. , Vlasenko Valeriy G. , Zubenko Alexander A. 
Published: December 2008

AbstractThe series of binuclear Cu(II) and Ni(II) complexes with an asymmetrical exchange fragment based on 2,6‐diformyl‐4‐methylphenol bishydrazone has been synthesized for the first time. The compositions and structures of both ligands and its complexes have been established with the data of IR, 1H NMR, and extended X‐ray absorption fine structure (EXAFS) spectroscopical studies as well as magnetic measurements. The structure of [Ni2L3(μ‐Pz)]·2CH3OH (L = triply deprotonated form of bishydrazone, Pz = pyrazol) was confirmed by X‐ray crystallographic analysis. In this complex, the coordination environment of two nickel ions is quite different, one nickel atom is square‐planar and the other is distorted octahedral coordinated. The values of exchange parameter calculated in terms of HDVV theory have been compared with the features of an asymmetrical exchange fragment's electronic and geometrical structure.