bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bahnhofshallen im Osten Deutschlands
Authors: Weller Bernhard , Tasche Martin 
Published: March 2006

AbstractDie Geschichte des Eisenbaus ist eng verbunden mit der Ausprägung des Konstruktiven Ingenieurbaus im 19. Jahrhundert [1]. An der Eisenbahn läßt sich die Entstehung des Neuen der mechanisierten Zivilisation exemplarisch ablesen [2]. Die großstädtischen Bahnhöfe, insbesondere die großen Hallenbauwerke, machen einen Abschnitt der Geschichte des Konstruierens unmittelbar erfahrbar. Die Beschreibung der Bahnhofshallen in Ostdeutschland ist Auftakt einer Reihe, die in loser Folge über die Konstruktionsgeschichte ausgewählter Bauformen berichten wird.
Teaching nature of science within a controversial topic: Integrated versus nonintegrated
Authors: Khishfe Rola , Lederman Norman 
Published: March 2006

AbstractThis study investigated the influence of two different explicit instructional approaches in promoting more informed understandings of nature of science (NOS) among students. Participants, a total of 42 students, comprised two groups in two intact sections of ninth grade. Participants in the two groups were taught environmental science by their regular classroom teacher, with the difference being the context in which NOS was explicitly taught. For the “integrated” group, NOS instruction was related to the science content about global warming. For the “nonintegrated” group, NOS was taught through a set of activities that specifically addressed NOS issues and were dispersed across the content about global warming. The treatment for both groups spanned 6 weeks and addressed a unit about global warming and NOS. An open‐ended questionnaire, in conjunction with semistructured interviews, was used to assess students' views before and after instruction. Results showed improvements in participants' views of NOS regardless of whether NOS was integrated within the regular content about global warming. Comparison of differences between the two groups showed “slightly” greater improvement in the informed views of the integrated group participants. On the other hand, there was greater improvement in the transitional views of the nonintegrated group participants. Therefore, the overall results did not provide any conclusive evidence in favor of one approach over the other. Implications on the teaching and learning of NOS are discussed. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 395–418, 2006
The conservative management of cervical ectopic pregnancies
Authors: Kirk E. , Condous G. , Haider Z. , Syed A. , Ojha K. , Bourne T. 
Published: March 2006

AbstractObjectiveTo evaluate the role of conservative management in the treatment of cervical ectopic pregnancies.MethodsThis was a retrospective analysis of all cervical ectopic pregnancies diagnosed in women attending our early pregnancy unit between April 1997 and September 2004 inclusive. The diagnosis of cervical ectopic pregnancy was made using transvaginal ultrasound. Clinical and demographic data were recorded in all cases. Serum human chorionic gonadotropin levels were measured at presentation and monitored subsequently to determine the rate of successful resolution. Conservative management was in the form of medical or expectant management. Medical management involved administration of systemic or intra‐amniotic methotrexate, with or without intra‐amniotic potassium chloride. Systemic methotrexate was either a single dose of 50 mg/m2 or an alternate‐day regimen of methotrexate at 1 mg/kg (days 1,3,5) with folinic acid rescue (days 2,4,6). If intra‐amniotic treatment was required, this was either 50 mg methotrexate or 5 mmol/L potassium chloride.ResultsSeven cervical ectopic pregnancies were diagnosed during the study period. Three cases were managed successfully with a single dose of methotrexate. One case was managed successfully using a multiple‐dose methotrexate regimen. Another case failed medical management with both the single‐ and multiple‐dose regimens but was successfully treated after potassium chloride was given intra‐amniotically under ultrasound guidance. One case was successfully treated with intra‐amniotic methotrexate and another was managed expectantly. There was no associated morbidity or mortality during the study period. We also performed a review of the current literature.ConclusionThe conservative management of cervical ectopic pregnancy is effective and safe. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Adaptive polynomial predistorters for M‐QAM transmission using non‐linear power amplifiers
Authors: Vo Thai Hoa , Le‐Ngoc Tho , Besbes Hichem 
Published: March 2006

AbstractIn this paper, adaptive baseband polynomial predistortion techniques are introduced to counter‐balance the AM/AM and AM/PM non‐linear effects of the transmit power amplifier. The proposed polynomial predistortion scheme is based on polar coordinate representation. Both LMS and RLS concepts are used to derive the adaptive algorithms. An enhanced LMS‐based algorithm with fast convergence and low complexity is proposed. For very fast convergence, a cascaded RLS‐based adaptive polynomial predistorter structure is introduced. The performance of the proposed schemes in terms of intermodulation distortion, spectral regrowth, and convergence rate are examined. The obtained results show that the polynomial predistortion schemes can be used in M‐QAM transmitters with power amplifiers operating near saturation to achieve a highest power efficiency. Copyright © 2006 John Wiley & Sons, Ltd.
Adding sense of spatial locality to routing protocols for mobile ad hoc networks
Authors: Chang Ruay‐Shiung , Tsai Chang‐Zhou 
Published: March 2006

AbstractRecently, there has been an increasing interest in mobile ad hoc networks. In a mobile ad hoc network, each mobile node can freely move around and the network is dynamically constructed by collections of mobile nodes without using any existing network infrastructure. Compared to static networks, it faces many problems such as the inefficiency of routing algorithms. Also, the number of control packets in any routing algorithm increases as the mobile speed or the number of mobile nodes increases. Most of the current routing protocols in ad hoc networks broadcast the control packets to the entire network. Therefore, by reducing the number of control packets, the efficiency of the network routing will be improved. If we know where the destination is, we can beam our search toward that direction. However, without using global positioning systems, how can we do this? Define the range nodes as the 1‐hop or 2‐hop neighbors of the destination node. In this paper, we propose using the range nodes to direct our searches for the destination. It can be combined with the existing routing protocols to reduce the control overhead. We show through simulations that AODV and DSR combined with the range node method outperforms the original AODV and DSR routing protocols in terms of control packets overhead. We also show that the delay introduced in find range nodes is insignificant. Copyright © 2006 John Wiley & Sons, Ltd.
Optimal decision strategies for paging in mobile cellular networks
Authors: Koukoutsidis I. Z. , Demestichas P. P. , Papaioannou P. I. , Theologou M. E. 
Published: March 2006

AbstractA high‐level technical survey of paging in mobile cellular communication networks is presented in this paper. We view paging as an optimal decision problem and explore different strategies based on sequential decisions. The examined schemes concentrate on different perspectives of the problem, depending on the type of decisions and the amount of information available or exploitable by the system. This approach provides a useful categorization and an easy conceptual basis for their theoretical investigation, necessary for the deployment of advanced paging algorithms. Because of its suggested generality, the discussed framework is also laid as reference for further research. As modern networks evolve, more emphasis will be given towards optimization in all aspects of a network system. The schemes presented greatly reduce paging costs and can be used in cooperation with known location update strategies to make part of a real network location management system. Copyright © 2006 John Wiley & Sons, Ltd.
Attention bias to faces in Asperger Syndrome: a pictorial emotion Stroop study
Authors: ASHWIN CHRIS , WHEELWRIGHT SALLY , BARON-COHEN SIMON 
Published: March 2006

Background. Emotional Stroop tasks have shown attention biases of clinical populations towards stimuli related to their condition. Asperger Syndrome (AS) is a neuropsychiatric condition with social and communication deficits, repetitive behaviours and narrow interests. Social deficits are particularly striking, including difficulties in understanding others.Method. We investigated colour-naming latencies of adults with and without AS to name colours of pictures containing angry facial expressions, neutral expressions or non-social objects. We tested three hypotheses: whether (1) controls show longer colour-naming latencies for angry versus neutral facial expressions with male actors, (2) people with AS show differential latencies across picture types, and (3) differential response latencies persist when photographs contain females.Results. Controls had longer latencies to pictures of male faces with angry compared to neutral expressions. The AS group did not show longer latencies to angry versus neutral expressions in male faces, instead showing slower latencies to pictures containing any facial expression compared to objects. When pictures contained females, controls no longer showed longer latencies for angry versus neutral expressions. However, the AS group still showed longer latencies to all facial picture types, compared to objects, providing further evidence that faces produce interference effects for this clinical group.Conclusions. The pictorial emotional Stroop paradigm reveals normal attention biases towards threatening emotional faces. The AS group showed Stroop interference effects to all facial stimuli regardless of expression or sex, suggesting that faces cause disproportionate interference in AS.
No evidence for preferential involvement of medial temporal lobe structures in high-functioning autism
Authors: PALMEN SASKIA J. M. C. , DURSTON SARAH , NEDERVEEN HILDE , VAN ENGELAND HERMAN 
Published: March 2006

Background. Autism is a neurodevelopmental disorder associated with slight increases in brain volume. There has been some suggestion that medial temporal lobe structures may be preferentially involved in this disorder, although results have not always been consistent. Here, we investigate amygdala and hippocampus volumes in medication-naive subjects with high-functioning autism.Method. Whole-brain magnetic resonance imaging scans were acquired from 42 patients and 42 closely matched, healthy control subjects.Results. Amygdala volume did not differ significantly between patients and controls. A significant increase in hippocampal volume was proportional to an increase in overall brain volume.Conclusions. These results argue against preferential involvement of medial temporal lobe structures in autism, at least in high-functioning medication-naive individuals.
Controlling a bipedal walking robot actuated by pleated pneumatic artificial muscles
Authors: Vanderborght Bram , Verrelst Björn , Van Ham Ronald , Lefeber Dirk 
Published: March 2006

This paper reports on the control structure of the pneumatic biped Lucy. The robot is actuated with pleated pneumatic artificial muscles, which have interesting characteristics that can be exploited for legged locomotion. They have a high power to weight ratio, an adaptable compliance and they can absorb impact effects.The discussion of the control architecture focuses on the joint trajectory generator and the joint trajectory tracking controller. The trajectory generator calculates trajectories represented by polynomials based on objective locomotion parameters, which are average forward speed, step length, step height and intermediate foot lift. The joint trajectory tracking controller is divided in three parts: a computed torque module, a delta-p unit and a bang-bang pressure controller. The control design is formulated for the single support and double support phase, where specifically the trajectory generator and the computed torque differs for these two phases.The first results of the incorporation of this control architecture in the real biped Lucy are given. Several essential graphs, such as pressure courses, are discussed and the effectiveness of the proposed algorithm is shown by the small deviations between desired and actual attained objective locomotion parameters.
Cell binding, internalization and cytotoxic activity of human granzyme B expressed in the yeastPichia pastoris
Authors: Giesübel Ulrike , Dälken Benjamin , Mahmud Hayat , Wels Winfried S. 
Published: March 2006

Granzyme B (GrB) is an apoptosis-inducing protease of cytotoxic lymphocytes. We have investigated intracellular and extracellular effects of human GrB using recombinant protein expressed in the yeast Pichia pastoris. GrB was rapidly taken up by HeLa cells, and accumulated in vesicular structures in the cytoplasm. There it remained inactive and could not be liberated by the endosomolytic reagent chloroquine, indicating that the vesicular structures are distinct from late endosomes and lysosomes. Direct cytosolic delivery of GrB with a cationic lipid-based transduction reagent, however, resulted in the induction of apoptotic cell death. After prolonged incubation at or above 125 nM, GrB on its own induced pronounced morphological changes in human tumour cells, leading to partial loss of contact to the culture support. This extracellular effect was dependent on enzymatic activity and could be reversed by removal of the protein, suggesting GrB-dependent cleavage of extracellular matrix components as the underlying mechanism.
Kinetic, inhibition and structural studies on 3-oxoacyl-ACP reductase from Plasmodium falciparum, a key enzyme in fatty acid biosynthesis
Authors: Wickramasinghe Sasala R. , Inglis Kirstine A. , Urch Jonathan E. , Müller Sylke , van Aalten Daan M. F. , Fairlamb Alan H. 
Published: March 2006

Type II fatty acid biosynthesis represents an attractive target for the discovery of new antimalarial drugs. Previous studies have identified malarial ENR (enoyl acyl-carrier-protein reductase, or FabI) as the target for the antiseptic triclosan. In the present paper, we report the biochemical properties and 1.5 Å (1 Å=0.1 nm) crystal structure of OAR (3-oxoacyl acyl-carrier-protein reductase, or FabG), the second reductive step in fatty acid biosynthesis and its inhibition by hexachlorophene. Under optimal conditions of pH and ionic strength, Plasmodium falciparum OAR displays kinetic properties similar to those of OAR from bacteria or plants. Activity with NADH is &lt;3% of that with NADPH. Fluorescence enhancement studies indicate that NADPH can bind to the free enzyme, consistent with kinetic and product inhibition studies suggesting a steady-state ordered mechanism. The crystal structure reveals a tetramer with a sulphate ion bound in the cofactor-binding site such that the side chains of the catalytic triad of serine, tyrosine and lysine are aligned in an active conformation, as previously observed in the Escherichia coli OAR–NADP+ complex. A cluster of positively charged residues is positioned at the entrance to the active site, consistent with the proposed recognition site for the physiological substrate (3-oxoacyl-acyl-carrier protein) in E. coli OAR. The antibacterial and anthelminthic agent hexachlorophene is a potent inhibitor of OAR (IC50 2.05 μM) displaying non-linear competitive inhibition with respect to NADPH. Hexachlorophene (EC50 6.2 μM) and analogues such as bithionol also have antimalarial activity in vitro, suggesting they might be useful leads for further development.
Effects of N-linked glycosylation on the creatine transporter
Authors: Straumann Nadine , Wind Alexandra , Leuenberger Tina , Wallimann Theo 
Published: March 2006

The CRT (creatine transporter) is a member of the Na+- and Cl−-dependent neurotransmitter transporter family and is responsible for the import of creatine into cells, and thus is important for cellular energy metabolism. We established for CRT an expression system in HEK-293 cells that allowed biochemical, immunological and functional analysis of CRT wild-type and glycosylation-deficient mutants. Analysis of HA (haemagglutinin)-tagged CRT-NN (wild-type rat CRT with an HA-tag at the C-terminus) revealed several monomeric immunoreactive species with apparent molecular masses of 58, 48 and 43 kDa. The 58 kDa species was shown to be plasma-membrane-resident by EndoHf (endoglycosidase Hf) and PNGase F (peptide N-glycosidase F) treatments and represents fully glycosylated CRT, whereas the 48 kDa and 43 kDa species were glycosylation intermediates and non-glycosylated CRT respectively. Glycosylation-deficient mutants (Asn192Asp, Asn197Asp and Asn192Asp/Asn197Asp) showed altered electrophoretic mobility, indicating that CRT is indeed N-glycosylated. In addition, a prominent CRT band in the range of 75–91 kDa was also detected. Pharmacological inhibition of N-linked glycosylation by tunicamycin in CRT-NN-expressing cells gave a similar reduction in molecular mass, corroborating the finding that Asn192 and Asn197 are major N-glycosylation sites in CRT. Although the apparent Km was not significantly affected in glycosylation-deficient mutants compared with CRT-NN, we measured reduced Vmax values for all mutants (21–28% residual activity), and 51% residual activity after enzymatic deglycosylation of surface proteins in intact CRT-NN cells by PNGase F. Moreover, immunocytochemical analysis of CRT-NN- and CRT-DD-expressing cells (where CRT-DD represents a non-glycosylated double mutant of CRT, i.e. Asn192Asp/Asn197Asp) showed a lower abundance of CRT-DD in the plasma membrane. Taken together, our results suggest that plasma-membrane CRT is glycosylated and has an apparent monomer molecular mass of 58 kDa. Furthermore, N-linked glycosylation is neither exclusively important for the function of CRT nor for surface trafficking, but affects both processes. These findings may have relevance for closely related neurotransmitter transporter family members.
Reactivity of free thiol groups in type-I inositol trisphosphate receptors
Authors: Joseph Suresh K. , Nakao Steven K. , Sukumvanich Siam 
Published: March 2006

The IP3R (inositol 1,4,5-trisphosphate receptor) Ca2+-release channel is known to be sensitive to thiol redox state. The present study was undertaken to characterize the number and location of reactive thiol groups in the type-I IP3R. Using the fluorescent thiol-reactive compound monobromobimane we found that approx. 70% of the 60 cysteine residues in the type-I IP3R are maintained in the reduced state. The accessibility of these residues was assessed by covalently tagging the IP3R in membranes with a 5 kDa or 20 kDa MPEG [methoxypoly(ethylene glycol) maleimide]. MPEG reaction caused a shift in the mobility of IP3R on SDS/PAGE that was blocked by pretreatment of the membranes with dithiothreitol, N-ethylmaleimide, mersalyl or thimerosal, indicating that MPEG reactivity was specific to thiol groups on the IP3R. Trypsin cleavage of the type-I IP3R generates five defined domains. In cerebellum membranes, MPEG reacted over a 5 min interval with tryptic fragment I and fragment III, but not fragments II, IV or V. Fragment I appears as a doublet in cerebellum membranes, corresponding to the presence and absence of the SI splice site in this region (SI is a spliced domain corresponding to amino acids 318–332). Only the fragment I band corresponding to the SI(+) splice form shifted after reaction with MPEG. Expression of SI(+) and SI(−) spliced forms in COS cell microsomes confirmed this result. The MPEG-induced shift was not prevented when the cysteine residue present in the SI splice domain (C326A) or the remaining seven cysteine residues in fragment I were individually mutated. Of the combination mutations screened, only the mutation of C206/214/326A blocked MPEG reactivity in fragment I. We conclude that a set of highly reactive cysteine residues in fragment I are differentially accessible in the SI(+) and SI(−) splice variants of the type-I IP3R.
Quantitative mapping of oxidation-sensitive cysteine residues in SERCA in vivo and in vitro by HPLC–electrospray-tandem MS: selective protein oxidation during biological aging
Authors: Sharov Victor S. , Dremina Elena S. , Galeva Nadezhda A. , Williams Todd D. , Schöneich Christian 
Published: March 2006

The selective reversible S-glutathiolation of specific SERCA (sarcoplasmic/endoplasmic-reticulum Ca2+-ATPase) cysteine residues represents a novel physiologic pathway of NO (nitric oxide)-dependent arterial smooth muscle relaxation [Adachi, Weisbrod, Pimentel, Ying, Sharov, Schöneich and Cohen (2004) Nat. Med. 10, 1200–1207]. This mechanism may be impaired through the irreversible oxidation of functionally important cysteine residues as a consequence of oxidative stress and aging. To establish whether in vivo aging and in vitro oxidation by peroxynitrite result in the loss of such functionally important cysteine residues of SERCA, we have developed and optimized a quantitative method to monitor the oxidation state of the individual SERCA cysteine residues using a maleimide-based fluorescence dye, TG1 (ThioGlo® 1), as a label for cysteine residues that have not been altered by oxidation and are not involved in disulphide bridges. A high efficiency for TG1 labelling of such residues and the chemical structure of cysteine–TG1 adducts were validated by MS analysis of model peptides, model proteins and rat skeletal muscle SERCA1. Tryptic peptides containing 18 out of a total of 24 cysteine residues were identified by HPLC–ESI (electrospray ionization)–MS/MS (tandem MS). Two cysteine residues, at positions 344 and 349, were detected in the form of an internal disulphide bridge, and another 16 were found to be labelled with TG1. Using HPLC–ESI–MS, we quantitatively mapped peroxynitrite oxidation of eight cysteine residues (positions 364, 417, 420, 498, 525, 674, 675 and 938), some of which are involved in the control of SERCA activity. Biological aging resulted in the partial modification of cysteine residues 377, 498, 525, 561, 614, 636, 674, 675, 774 and 938. Neither peroxynitrite exposure nor biological aging affected the apparent SERCA1 ATP affinity. Our data show an age-dependent loss of cysteine residues (approx. 2.8 mol of cysteine/mol of SERCA1), which may be partially responsible for the age-dependent decrease in the specific Ca2+-ATPase activity (by 40%).