bluuebunny/crossref_metadata_2025 huggingface dataset:
A convenient room temperature polycondensation toward hyperbranched AB2‐type all‐aromatic polyesters with phenol terminal groups
Authors: Erber Michael , Boye Susanne , Hartmann Tobias , Voit Brigitte I. , Lederer Albena
Published: August 2009

As a convenient alternative to the classical melt polycondensation the one‐pot solution polycondensation of suitable AB2 monomers under mild conditions has been successfully adapted to hyperbranched all‐aromatic polyester with phenol terminal groups. The polymerization was performed in solution at room temperature directly using commercially available 3,5‐dihydroxybenzoic acid as monomer and 4‐(dimethylamino) pyridinium 4‐tosylate as catalyst to suppress the formation of N‐acylurea. Different carbodiimides as coupling agents were investigated to find the optimal esterification conditions. The polymers have been characterized extensively and were compared with their well‐known analogs synthesized in melt. The characterization was carried out by NMR spectroscopy, size exclusion chromatography, and asymmetric flow‐field flow fractionation as an alternative separation technique for multifunctional polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5158–5168, 2009
Airway reactivity in children before and after stem cell transplantation
Authors: Bentur Lea , Lapidot Moshe , Livnat Galit , Hakim Fahed , Lidroneta‐Katz Claudia , Porat Iris , Vilozni Daphna , Elhasid Ronit
Published: August 2009

Stem cell transplantation (SCT) is associated with pulmonary complications. We encountered several children post‐SCT with a clinical picture suggestive of airway hyper‐reactivity (AHR) and evidence of reversible airway obstruction that was not reported pre‐transplant.

We evaluated the possibility of increased AHR as assessed by methacholine challenge test (MCT) following the course of SCT, and assessed a possible correlation between AHR and pulmonary complications.

This was a prospective study evaluating consecutive patients referred for SCT to the Department of Pediatric Hemato‐Oncology. Evaluation included pulmonary function test and MCT before and after SCT, and assessment of pulmonary complications.

Twenty‐one of 33 patients completed the study. The mean PC20 was 14.3 ± 4.1 mg/ml prior to SCT; afterward the mean PC20 decreased to 11.2 ± 5.6 mg/ml (P = 0.018). The number of patients with airway reactivity (PC20 ≤ 8 mg/ml) increased from 2/21 patients before SCT to 8/21 patients after SCT (P = 0.043; McNemar test with Yates correction). Pulmonary complications and hospitalization were recorded in 33.3% of the patients (7/21 patients): 62.5% of the patients (5 patients) with AHR compared to 15.4% (2 patients) in the group without AHR (P = 0.041; Fisher exact test). There were 10 hospitalizations among the 8 patients with positive MCT compared to 2 hospitalizations in 13 patients with negative MCT (median 1 vs. 0, P = 0.045; Mann–Whitney U‐test).

Increased airway reactivity was observed in our study following the course of SCT. Positive MCT after SCT may be associated with increased risk of pulmonary complications. Larger prospective studies are needed to evaluate the possible mechanisms responsible for increased AHR and the clinical importance of these findings. Pediatr Pulmonol. 2009; 44:845–850. © 2009 Wiley‐Liss, Inc.
Designed zinc finger protein interacting with the HIV‐1 integrase recognition sequence at 2‐LTR‐circle junctions
Authors: Sakkhachornphop Supachai , Jiranusornkul Supat , Kodchakorn Kanchanok , Nangola Sawitree , Sirisanthana Thira , Tayapiwatana Chatchai
Published: August 2009

Integration of HIV‐1 cDNA into the host genome is a crucial step for viral propagation. Two nucleotides, cytosine and adenine (CA), conserved at the 3′ end of the viral cDNA genome, are cleaved by the viral integrase (IN) enzyme. As IN plays a crucial role in the early stages of the HIV‐1 life cycle, substrate blockage of IN is an attractive strategy for therapeutic interference. In this study, we used the 2‐LTR‐circle junctions of HIV‐1 DNA as a model to design zinc finger protein (ZFP) targeting at the end terminal portion of HIV‐1 LTR. A six‐contiguous ZFP, namely 2LTRZFP was designed using zinc finger tools. The designed motif was expressed and purified from E. coli to determine its binding properties. Surface plasmon resonance (SPR) was used to determine the binding affinity of 2LTRZFP to its target DNA. The level of dissociation constant (Kd) was 12.0 nM. The competitive SPR confirmed that 2LTRZFP specifically interacted with its target DNA. The qualitative binding activity was subsequently determined by EMSA and demonstrated the aforementioned correlation. In addition, molecular modeling and binding energy analyses were carried out to provide structural insight into the binding of 2LTRZFP to the specific and nonspecific DNA target. It is suggested that hydrogen‐bonding interactions play a key role in the DNA recognition mechanisms of the designed ZFP. Our study suggested an alternative HIV therapeutic strategy using ZFP interference of the HIV integration process.
A note on open‐chain transfer matrices from q‐deformed su(2|2)S‐matrices
Authors: Murgan R.
Published: August 2009

In this note, we perform Sklyanin's construction of commuting open‐chain/boundary transfer matrices to the q‐deformed SU(2|2) bulk S‐matrix of Beisert and Koroteev and a corresponding boundary S‐matrix. This also includes a corresponding commuting transfer matrix using the graded version of the q‐deformed bulk S‐matrix. Utilizing the crossing property for the bulk S‐matrix, we argue that the transfer matrix for both graded and non‐graded versions contains a crucial factor which is essential for commutativity.
Sequence fingerprint and structural analysis of the SCOR enzyme A3DFK9 from Clostridium thermocellum
Authors: Huether Robert , Liu Zhi‐Jie , Xu Hao , Wang Bi‐Cheng , Pletnev Vladimir Z. , Mao Qilong , Duax William L. , Umland Timothy C.
Published: August 2009

We have identified a highly conserved fingerprint of 40 residues in the TGYK subfamily of the short‐chain oxidoreductase enzymes. The TGYK subfamily is defined by the presence of an N‐terminal TGxxxGxG motif and a catalytic YxxxK motif. This subfamily contains more than 12,000 members, with individual members displaying unique substrate specificities. The 40 fingerprint residues are critical to catalysis, cofactor binding, protein folding, and oligomerization but are substrate independent. Their conservation provides critical insight into evolution of the folding and function of TGYK enzymes. Substrate specificity is determined by distinct combinations of residues in three flexible loops that make up the substrate‐binding pocket. Here, we report the structure determinations of the TGYK enzyme A3DFK9 from Clostridium thermocellum in its apo form and with bound NAD+ cofactor. The function of this protein is unknown, but our analysis of the substrate‐binding loops putatively identifies A3DFK9 as a carbohydrate or polyalcohol metabolizing enzyme. C. thermocellum has potential commercial applications because of its ability to convert biomaterial into ethanol. A3DFK9 contains 31 of the 40 TGYK subfamily fingerprint residues. The most significant variations are the substitution of a cysteine (Cys84) for a highly conserved glycine within a characteristic VNNAG motif, and the substitution of a glycine (Gly106) for a highly conserved asparagine residue at a helical kink. Both of these variations occur at positions typically participating in the formation of a catalytically important proton transfer network. An alternate means of stabilizing this proton wire was observed in the A3DFK9 crystal structures. Proteins 2010. © 2009 Wiley‐Liss, Inc.
Substrate uptake and protein stability relationship in mammalian histidine decarboxylase
Authors: Pino‐Ángeles A. , Morreale A. , Negri A. , Sánchez‐Jiménez F. , Moya‐García A. A.
Published: August 2009

There is some evidence linking the substrate entrance in the active site of mammalian histidine decarboxylase and an increased stability against proteolytic degradation. In this work, we study the basis of this relationship by means of protein structure network analysis and molecular dynamics simulations. We find that the substrate binding to the active site influences the conformation of a flexible region sensible to proteolytic degradation and observe how formation of the Michaelis–Menten complex increases stability in the conformation of this region. Proteins 2010. © 2009 Wiley‐Liss, Inc.
I‐TASSER: Fully automated protein structure prediction in CASP8
Authors: Zhang Yang
Published: August 2009

The I‐TASSER algorithm for 3D protein structure prediction was tested in CASP8, with the procedure fully automated in both the Server and Human sections. The quality of the server models is close to that of human ones but the human predictions incorporate more diverse templates from other servers which improve the human predictions in some of the distant homology targets. For the first time, the sequence‐based contact predictions from machine learning techniques are found helpful for both template‐based modeling (TBM) and template‐free modeling (FM). In TBM, although the accuracy of the sequence based contact predictions is on average lower than that from template‐based ones, the novel contacts in the sequence‐based predictions, which are complementary to the threading templates in the weakly or unaligned regions, are important to improve the global and local packing in these regions. Moreover, the newly developed atomic structural refinement algorithm was tested in CASP8 and found to improve the hydrogen‐bonding networks and the overall TM‐score, which is mainly due to its ability of removing steric clashes so that the models can be generated from cluster centroids. Nevertheless, one of the major issues of the I‐TASSER pipeline is the model selection where the best models could not be appropriately recognized when the correct templates are detected only by the minority of the threading algorithms. There are also problems related with domain‐splitting and mirror image recognition which mainly influences the performance of I‐TASSER modeling in the FM‐based structure predictions. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Assessment of CASP8 structure predictions for template free targets
Authors: Ben‐David Moshe , Noivirt‐Brik Orly , Paz Aviv , Prilusky Jaime , Sussman Joel L. , Levy Yaakov
Published: August 2009

The biennial CASP experiment is a crucial way to evaluate, in an unbiased way, the progress in predicting novel 3D protein structures. In this article, we assess the quality of prediction of template free models, that is, ab initio prediction of 3D structures of proteins based solely on the amino acid sequences, that is, proteins that did not have significant sequence identity to any protein in the Protein Data Bank. There were 13 targets in this category and 102 groups submitted predictions. Analysis was based on the GDT_TS analysis, which has been used in previous CASP experiments, together with a newly developed method, the OK_Rank, as well as by visual inspection. There is no doubt that in recent years many obstacles have been removed on the long and elusive way to deciphering the protein‐folding problem. Out of the 13 targets, six were predicted well by a number of groups. On the other hand, it must be stressed that for four targets, none of the models were judged to be satisfactory. Thus, for template free model prediction, as evaluated in this CASP, successes have been achieved for most targets; however, a great deal of research is still required, both in improving the existing methods and in development of new approaches. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Silicon nanocluster aggregation in SiO2:Si layers
Authors: Fitting H.‐J. , Kourkoutis L. Fitting , Salh Roushdey , Zamoryanskaya M. V. , Schmidt B.
Published: August 2009

Energy‐filtered transmission electron microscopy (EFTEM) in combination with electron energy loss spectroscopy (EELS) and cathodoluminescence (CL) have been used to investigate Si+‐implanted amorphous silicon dioxide layers and the formation of Si nanoclusters. Therefore, amorphous, thermally grown SiO2 layers on Si substrate were implanted by Si+ ions with an energy of 150 keV and a dose of 5 × 1016 ions/cm2 leading to an atomic dopant fraction of about 4 at%. Afterwards a post‐implantation thermal annealing has been performed at temperatures Ta = 700–1300 °C, for 60 min in vacuum. This thermal annealing leads to Si cluster formation and a change of the SiOx matrix from about x = 1.923 to 1.929 connected with additional visible luminescence bands in the green‐yellow region. CL spectra in the near infrared (NIR) region indicate such Si aggregation by appearance of an additional band in extension of the common NBOHC band at 1.9 eV towards the NIR region. This band shifts with increasing annealing temperatures of the implanted sample to lower energies, probably, due to cluster growth and quantum confinement effects.
Influence of hydrogen on nanocrystalline diamond surfaces investigated with HREELS and XPS
Authors: Haensel Thomas , Uhlig Jens , Koch Roland J. , Ahmed Syed Imad‐Uddin , Garrido José A. , Steinmüller‐Nethl Doris , Stutzmann Martin , Schaefer Juergen A.
Published: August 2009

Nanocrystalline diamond (NCD) films are of great importance for many applications. They can be implemented as transparent protective coatings or for the use in electronic devices, sensor systems, and bioelectronic systems. In many applications the surface properties dictate the eventual performance of the device and, therefore, need to be thoroughly understood. This paper is devoted to investigating the changes occurring in the vibrational structure and surface chemical composition of hydrogen‐containing NCD films as a function of annealing treatments as well as exposure to atomic hydrogen. High resolution electron energy loss spectroscopy (HREELS) as a surface sensitive method was utilized to analyze the temperature‐correlated desorption of hydrogen and graphitization of the surface. These measurements were correlated with X‐ray‐induced photoelectron spectroscopy (XPS) measurements to study the chemical composition. Results indicate that water and graphitic‐like contaminations are removed from the sample surface after annealing up to about 350 °C. Annealing the sample up to 950 °C decreases the hydrogen content drastically. At temperatures up to 1050 °C the CH stretching and bending modes are not detectable, indicating that the hydrogen is totally removed from the surface. Analysis of the C 1s XPS spectra revealed that a graphitic‐like phase is formed. An atomic hydrogen treatment was applied to get further information about the surface composition. Additionally, from our HREELS and XPS data we are able to determine the sp2/sp3 ratio for the different surface treatments.
Dynamic fatigue studies of ZnO nanowires by in‐situ transmission electron microscopy
Authors: Gao Zhiyuan , Ding Yong , Lin Shisheng , Hao Yue , Wang Zhong Lin
Published: August 2009

The fatigue behavior of ceramic ZnO nanowires (NWs) has been investigated under resonance cyclic loading conditions using in‐situ transmission electron microscopy (TEM). After mechanical deformation at the resonance frequency at a vibration angle of 5.2° for 35 billion cycles, no failure or any defect generations have been found. We believe that the dislocation‐free nature of NWs and the large surface‐to‐volume ratio contribute to the NWs' ability to undergo deformation without fatigue or fracture, proving their durability and toughness for nanogenerators and nanopiezotronics.

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(© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identification of plant extracts with potential antidiabetic properties: effect on human peroxisome proliferator‐activated receptor (PPAR), adipocyte differentiation and insulin‐stimulated glucose uptake
Authors: Christensen Kathrine B. , Minet Ariane , Svenstrup Henrik , Grevsen Kai , Zhang Hongbin , Schrader Eva , Rimbach Gerald , Wein Silvia , Wolffram Siegfried , Kristiansen Karsten , Christensen Lars P.
Published: August 2009

Thiazolidinediones (TZDs) are insulin sensitizing drugs used to treat type 2 diabetes. The primary target of the TZDs is the peroxisome proliferator‐activated receptor (PPAR) γ, a key regulator of adipogenesis and glucose homeostasis. Currently prescribed TZDs are full PPARγ agonists, and their use is associated with several side effects. Partial PPARγ agonists appear to be associated with fewer side effects but may still confer the desired insulin sensitizing action. Extracts from common medicinal/food plants were tested in a screening platform comprising a series of bioassays, including tests for PPARγ, α and δ transactivation, adipocyte differentiation and insulin‐stimulated glucose uptake, allowing identification of plants containing potentially interesting PPAR agonists. Twenty‐two plant extracts out of 133 were found to increase insulin‐stimulated glucose uptake and 18 extracts were found to activate PPARγ, 3 to activate PPARα and γ, 6 to activate PPARδ and γ, and 9 to activate PPARγ, α and δ. Among the 24 different plant species tested in the platform, 50% were shown to contain compounds capable of activating PPARγ and stimulating insulin‐dependent glucose uptake with no or little effect on adipocyte differentiation warranting further studies and characterization. Copyright © 2009 John Wiley & Sons, Ltd.
A theoretical study on the LaF3 molecule embedded in argon matrix
Authors: Lanza Giuseppe
Published: August 2009

The LaF3·Arn (n = 1–21) clusters have been proposed as models to account for the matrix effects on the molecular properties of the LaF3 molecule isolated in argon solid matrix at cryogenic temperature. Because of the strong Lewis acid character of the LaF3 molecule, there is a substantial electron‐density transfer from the argon atoms to the molecule that induces important geometrical changes in the structure and vibrational frequencies. The present bottom‐up approach reveals the formation of two sets of structures close in energy having the D3h‐LaF3 and the C3v‐LaF3. The D3h‐LaF3 structures are more compact with respect to the C3v series. The largest investigated cluster of the D3h series, the LaF3·Ar21 resembles an hcp structure with the LaF3 occupying the central substitutional site that it is expected to be energetically preferred. The C3v‐LaF3 structures are more stable for lighter clusters and their high formation rates in the gas‐phase, immediately before matrix incorporation, could explain experimental IR/Raman results that point to a pyramidal shape for the molecule in argon matrix. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Multi‐residue analysis of eight thioamphetamine designer drugs in human urine by liquid chromatography/tandem mass spectrometry
Authors: Nieddu Maria , Boatto Gianpiero , Pirisi Maria Antonietta , Baralla Elena
Published: August 2009

An analytical procedure for the simultaneous determination in human urine of several thioamphetamine designer drugs (2C‐T and ALEPH series) is reported. The quantitative analysis was performed by liquid chromatography/tandem mass spectrometry and has been fully validated. The mass spectrometer was operated in positive‐ion, selected reaction monitoring (SRM) mode. In order to minimize interferences with matrix components and to preconcentrate target analytes, solid‐phase extraction was introduced in the method as a clean‐up step. The entire method was validated for selectivity, linearity, precision and accuracy. The method turned out to be specific, sensitive, and reliable for the analysis of amphetamine derivatives in urine samples. The calibration curves were linear over the concentration range of 1 to 100 ng mL−1 for all drugs with correlation coefficients that exceeded 0.996. The lower limits of detection (LODs) and quantification (LOQs) ranged from 1.2 to 4.9 ng mL−1 and from 3.2 to 9.6 ng mL−1, respectively. Copyright © 2009 John Wiley & Sons, Ltd.
In search of a mental model‐like concept for group‐level modeling
Authors: Kim Hyunjung
Published: August 2009

In system dynamics, we care about mental models, because it is what we attempt to describe, understand, and improve using qualitative maps and computer simulation models. But if we are developing maps and models from a group of individuals, can we still call what we are trying to study a mental model? The main difference between individual and group‐level phenomena is that in a group setting interaction and communication among individuals shape what is represented in maps and models. This paper attempts to clarify the object of our group‐level modeling by surveying existing literature searching for concepts similar to “mental model” at the group level. The survey leads to an insight that what we attempt to represent with our maps and models varies widely by our selection of modeling methods, and how we define our object will draw attention to a different set of theoretical literature. Copyright © 2009 John Wiley & Sons, Ltd.
Sustainable green catalysis by supported metal nanoparticles
Authors: Fukuoka Atsushi , Dhepe Paresh L.
Published: August 2009

The recent progress of sustainable green catalysis by supported metal nanoparticles is described. The template synthesis of metal nanoparticles in ordered porous materials is studied for the rational design of heterogeneous catalysts capable of high activity and selectivity. The application of these materials in green catalytic processes results in a unique activity and selectivity arising from the concerted effect of metal nanoparticles and supports. The high catalytic performances of Pt nanoparticles in mesoporous silica is reported. Supported metal catalysts have also been applied to biomass conversion by heterogeneous catalysis. Additionally, the degradation of cellulose by supported metal catalysts, in which bifunctional catalysis of acid and metal plays the key role for the hydrolysis and reduction of cellulose, is also reported. © 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 224–235; 2009: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.200900004
Early intervention in management of very preterm growth‐restricted fetuses: 2‐year outcome of infants delivered on fetal indication before 30 gestational weeks
Authors: Brodszki J. , Morsing E. , Malcus P. , Thuring A. , Ley D. , Maršál K.
Published: August 2009

Objectives

To describe the outcome of growth‐restricted fetuses with absent or reversed end‐diastolic flow (ARED) in the umbilical artery delivered on fetal indication before 30 gestational weeks.

Methods

Between 1998 and 2004, 42 fetuses with intrauterine growth restriction (IUGR) and ARED in the umbilical artery were delivered liveborn by Cesarean section on fetal indication before 30 gestational weeks. The median gestational age at delivery was 27 + 1 (range, 24 + 4 to 29 + 5) weeks. An additional four fetuses died in utero at a median gestational age of 24 + 2 (range, 23 + 5 to 25 + 4) weeks. Neonatal morbidity, infant mortality and major neurological morbidity of liveborn infants were compared with those in two control groups: all 371 liveborn infants delivered at < 30 weeks during the corresponding time period (Group A) and a subset of these, 42 matched infants without IUGR (Group B).

Results

Thirty‐two fetuses (7%) were delivered within 48 h of the occurrence of ARED (25 absent, seven reversed end‐diastolic flow). The remaining 10 fetuses (five absent, five reversed end‐diastolic flow) were monitored for a median of 6.5 (range, 3–18) days before delivery. One infant died in the neonatal period and three during the first year of postnatal life (2‐year survival 90%). The incidence of chronic lung disease was higher in the ARED Group than in Control Groups A and B (P = 0.001 and P = 0.03, respectively). There were no differences between the groups in the occurrence of necrotizing enterocolitis, cerebral hemorrhage or retinopathy of prematurity. Cerebral palsy was diagnosed in 14% of the index group compared with 11% and 17% of Control Groups A and B (P > 0.05).

Conclusions

Very preterm growth‐restricted fetuses with umbilical artery ARED delivered on fetal indication, in most cases before the occurrence of severe changes in the ductus venosus velocity waveforms and/or fetal heart rate tracings, showed high 2‐year survival and low morbidity. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Assessment of intracranial translucency (IT) in the detection of spina bifida at the 11–13‐week scan
Authors: Chaoui R. , Benoit B. , Mitkowska‐Wozniak H. , Heling K. S. , Nicolaides K. H.
Published: August 2009

Objective

Prenatal diagnosis of open spina bifida is carried out by ultrasound examination in the second trimester of pregnancy. The diagnosis is suspected by the presence of a ‘lemon‐shaped’ head and a ‘banana‐shaped’ cerebellum, thought to be consequences of caudal displacement of the hindbrain. The aim of the study was to determine whether in fetuses with spina bifida this displacement of the brain is evident from the first trimester of pregnancy.

Methods

In women undergoing routine ultrasound examination at 11–13 weeks' gestation as part of screening for chromosomal abnormalities, a mid‐sagittal view of the fetal face was obtained to measure nuchal translucency thickness and assess the nasal bone. In this view the fourth ventricle, which presents as an intracranial translucency (IT) between the brain stem and choroid plexus, is easily visible. We measured the anteroposterior diameter of the fourth ventricle in 200 normal fetuses and in four fetuses with spina bifida.

Results

In the normal fetuses the fourth ventricle was always visible and the median anteroposterior diameter increased from 1.5 mm at a crown–rump length (CRL) of 45 mm to 2.5 mm at a CRL of 84 mm. In the four fetuses with spina bifida the ventricle was compressed by the caudally displaced hindbrain and no IT could be seen.

Conclusion

The mid‐sagittal view of the face as routinely used in screening for chromosomal defects can also be used for early detection of open spina bifida. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Performance analysis of DSRC priority mechanism for road safety applications in vehicular networks
Authors: He Jianhua , Tang Zuoyin , O'Farrell Tim , Chen Thomas M.
Published: August 2009

Dedicated short range communications (DSRC) has been regarded as one of the most promising technologies to provide robust communications for large scale vehicle networks. It is designed to support both road safety and commercial applications. Road safety applications will require reliable and timely wireless communications. However, as the medium access control (MAC) layer of DSRC is based on the IEEE 802.11 distributed coordination function (DCF), it is well known that the random channel access based MAC cannot provide guaranteed quality of services (QoS). It is very important to understand the quantitative performance of DSRC, in order to make better decisions on its adoption, control, adaptation, and improvement. In this paper, we propose an analytic model to evaluate the DSRC‐based inter‐vehicle communication. We investigate the impacts of the channel access parameters associated with the different services including arbitration inter‐frame space (AIFS) and contention window (CW). Based on the proposed model, we analyze the successful message delivery ratio and channel service delay for broadcast messages. The proposed analytical model can provide a convenient tool to evaluate the inter‐vehicle safety applications and analyze the suitability of DSRC for road safety applications. Copyright © 2009 John Wiley & Sons, Ltd.
Load balancing and its performance evaluation for layer 3 and IEEE 802.21 frameworks in PMIPv6‐based wireless networks
Authors: Kim Mun‐Suk , Lee SuKyoung
Published: August 2009

Mobile IP (MIP) requires mobile nodes (MNs) to register with the home agents (HAs) whenever the MNs change their point of attachment (PoA: access point (AP) or base station (BS)) in different subnets. Thus, such registrations cause excessive signaling overhead and long service delay. To solve this problem, proxy mobile IPv6 (PMIPv6) has been proposed by the IETF NETLMM working group. In PMIPv6, a new entity called mobile access gateway (MAG) performs the mobility‐related signaling with the local mobility anchor (LMA) on behalf of the MN and establishes a tunnel with the LMA. However, a number of MNs must be associated with an MAG, which means that the MAG can be easily overloaded. Therefore, in this paper, we propose a load balancing mechanism among the MAGs in the PMIPv6 network. The PMIPv6 handover signaling procedure is extended to support the proposed load balancing mechanism. We also discuss using IEEE 802.21 Media Independent Handover (MIH) protocol for load balancing to determine the load status at the candidate PoAs, in addition to the load status at the candidate MAGs. To evaluate the performance, we analyze the average waiting time in the queue at the MAG. Through simulations and numerical analysis, we show that the proposed load balancing mechanism can produce less queueing delay at the MAG and a higher data transmission rate at the PoA than when a load balancing operation is not performed in the PMIPv6 network. Copyright © 2009 John Wiley & Sons, Ltd.
Uplink carrier frequency offset estimation for WiMAX OFDMA‐based ranging
Authors: Lin Yonghua , Fan Da , Wang Qing , Chen Jianwen
Published: August 2009

Ranging is one of the most important processes in the mobile worldwide interoperability for microwave access (WiMAX) standard, for resolving the uplink synchronization and near/far problems. In this paper, we focus on the multi‐user carrier frequency offset (CFO) estimation in both initial ranging and periodic ranging. After the analysis of some existing ranging methods, we propose two algorithms based on the correlation properties of pseudo noise (PN) sequences in time domain and frequency domain respectively. The root mean square error (RMSE) performance is evaluated in both additive white Gaussian noise (AWGN) channel and multi‐path fading channel. Simulation results show that the proposed frequency‐domain cross‐correlation method performs better than the proposed time‐domain cross‐correlation method, and is more robust to multi‐user interference and residual timing offset. Copyright © 2009 John Wiley & Sons, Ltd.
Adaptive reference code‐based MAI cancellation for DS‐CDMA
Authors: Won Jong Mook , Kim Jung Soo , Kim W. M.
Published: August 2009

A computationally efficient and practically deployable adaptive reference code‐based multiple access interference (MAI) cancellation scheme, in which the conventional transmitter/receiver architecture is minimally modified only at the receiver (and/or transmitter) end, is proposed for direct sequence code division multiple access (DS‐CDMA) communication. Upon numerical and theoretical analyses, the proposed communications system is seen to always outperform the existing conventional communications system. The theoretical analyses and results as presented are generally useful and applicable to any situation wherein IS95 pseudo noise (PN) codes are employed towards multiple access. Copyright © 2009 John Wiley & Sons, Ltd.
Resource allocation in OFDMA networks based on interior point methods
Authors: Mehrjoo Mehri , Moazeni Somayeh , Shen Xuemin (Sherman)
Published: August 2009

This paper studies a joint optimization problem of sub‐carrier assignment and power allocation in orthogonal frequency division multiple access (OFDMA) wireless networks. A major challenge in solving the optimization problem is non‐convexity caused by the combinatorial nature of sub‐carrier assignment problem and/or non‐convex objective functions. To address the combinatorial complexity, we formulate the resource allocation problem as an optimization problem with continuous variables. We propose a novel approach based on a penalty function method and an interior point method (PM/IPM) to solve the problem. In specific, using a two‐step implementation, the penalty method is applied first to convert the non‐convex feasible region to a convex one. Then, the interior point method is deployed to solve the problem which is non‐convex only in the objective function. To evaluate the performance of PM/IPM, we apply a genetic algorithm (GA) that achieves near optimal solutions of the problem by iterative searching. Copyright © 2009 John Wiley & Sons, Ltd.
Estimation of Impact of Surgical Disease Through Economic Modeling of Cleft Lip and Palate Care
Authors: Corlew D. Scott
Published: August 2009

Background

Assessing burden of disease encompasses the prevalence of disease entities, but it is the impact that affects the populace. Similarly, optimal evaluation of intervention programs shows impact rather than simply an enumeration of services. Economic effects are a fungible measure but are difficult to assess. Modeling of economic effects was used to evaluate a cleft program in Nepal and to demonstrate impact of alleviating this subset of the surgical burden of disease.

Methods

The database of patients who underwent care at a cleft center in Katmandu in 2005 was used. Disability adjusted life years averted were calculated. Using both GNI per capita and Value of a Statistical Life, the economic value to the individuals and to society was calculated.

Results

The two methods yielded a conservative and a generous estimate of economic impact of treating cleft lip and palate. Using GNI per capita, cleft lip repair added between $856 and $6,598 to lifetime individual income. For cleft palate, this ranged from $2,293 to $17,278. Using Value of a Statistical Life, cleft lip repair added between $56,919 and $143,363, and cleft palate between $152,372 and $375,412.

Conclusions

The immense economic gain realized by an intervention addressing a small proportion of the surgical burden of disease indicates the importance of these conditions to public health and well‐being. This methodology also lends itself to broader use and to further refinement as a means of evaluation of interventions. This has implications for health policy and for funding and resource allocation for surgical conditions in the developing world.
The Implications of Fraud in Medical and Scientific Research
Authors: Slesser Alistair A. P. , Qureshi Yassar A.
Published: August 2009

Fraud is an important issue that affects research of both scientific and clinical fields because of its potential to adversely affect patient care. Fraud can take many forms, each with varying prevalence and implications. A number of ethical institutions have been created to investigate and regulate this malpractice. Using case examples, we describe the various forms of fraud and their potential implications. The increasing importance of editorial responsibility is highlighted and discussed. Finally, we suggest solutions for how to effectively regulate and eradicate this practise.
A Novel Route for Preparation of Hollow Carbon Nanospheres Without Introducing Template
Authors: Li Minmin , Wu Qingsheng , Wen Ming , Shi Jianlin
Published: August 2009

A newly developed route for the synthesis of hollow carbon nanospheres without introducing template under hydrothermal conditions was reported. Hollow carbon nanospheres with the diameter of about 100 nm were synthesized using alginate as reagent only. Many instruments were applied to characterize the morphologies and structures of carbon hollow nanospheres, such as XRD, TEM, and Raman spectroscopy. The possible formation and growth mechanism of carbon hollow spheres were discussed on the basis of the investigation of reaction influence factors, such as temperature, time, and content. The findings would be useful for the synthesis of more materials with hollow structure and for the potential use in many aspects. The loading of SnO2on the surface of carbon hollow spheres was processed, and its PL property was also characterized.
Interfacial Properties of Extended‐Surfactant‐Based Microemulsions and Related Macroemulsions
Authors: Witthayapanyanon Anuradee , Phan Tri Thanh , Heitmann Todd C. , Harwell Jeffrey H. , Sabatini David A.
Published: August 2009

Extended surfactants containing an intermediate‐polarity spacer, such as polypropylene oxide, in between the hydrophilic head and the hydrocarbon tail are known to result in superior solubilization and low interfacial tension, though they exhibit slow kinetics. The present work seeks to evaluate both equilibrium and kinetic aspects of extended‐surfactant‐based micro‐ and macroemulsions. The interfacial morphology of the extended surfactant membrane, i.e., characteristic length (ξ) and interfacial rigidity (Er) at optimum middle‐phase microemulsion conditions, was characterized using the net‐average curvature model. The results showed that extended surfactants resulted in a relatively rigid interfacial membrane compared with conventional surfactants having similar hydrocarbon chain length. In addition, both ξ and Er parameters increased with the length of the polypropylene oxide spacer. Increasing Er values correlated to the slow coalescence rates of extended surfactant emulsified systems. Two alternative approaches (the addition of combined linkers and co‐surfactant) are shown to overcome the slow kinetics of coalescence while maintaining desirable high solubilization and low interfacial tension.
Frying Stability of Purified Mid‐Oleic Sunflower Oil Triacylglycerols with Added Pure Tocopherols and Tocopherol Mixtures
Authors: Warner Kathleen , Moser Jill
Published: August 2009

To determine the effects of the addition of pure tocopherols to triacylglycerols, α, γ, and δ tocopherols were added singly and in various combinations to stripped mid‐oleic sunflower oil (SMOSUN). Tortilla chips were fried in the treated oils and then aged at ambient temperature to determine storage stability of the fried food. Frying oils were evaluated for total polar compounds (TPC) as an indicator of oil deterioration, and they were also analyzed for retention of tocopherols. To determine effects of tocopherols on fried‐food stability, chips were evaluated for hexanal as an indicator of oxidative stability and for odor characteristics by a trained, experienced analytical sensory panel. Oils extracted from the tortilla chips were also analyzed for residual tocopherols. TPC were highest in the SMOSUN control with no additives followed by the SMOSUN containing only α tocopherol. The SMOSUN oil containing γ tocopherol had the best fry life as indicated by the lowest TPC. Hexanal content and rancid odor intensity were highest in the chips fried in the SMOSUN control and in the SMOSUN containing only α tocopherol. The most stable tortilla chips were fried in SMOSUN containing all three (α, γ, and δ) tocopherols; however, the lowest hexanal levels were measured when γ and δ tocopherols were added at their highest concentrations.
Claw toes after tibial fracture in children
Authors: Fitoussi Frank , Ilharreborde Brice , Guerin Florent , Souchet Philippe , Penneçot Georges F. , Mazda Keyvan
Published: August 2009

Purpose

The development of claw toe deformity following fracture of the tibia in children has not been described in our review of the literature. We report on the management of the acquired claw toe deformity after tibia fracture in five children.

Methods

We report on five patients, between 5 and 15 years of age, who developed clawing of the hallux following a fracture of the tibia. In two patients, the lesser toes were involved. On examination, when the ankle was passively plantar flexed, a flexion contracture of the interphalangeal joint of the hallux became fully flexible. When the ankle was dorsiflexed, the clawing became more obvious and fixed. A magnetic resonance imaging (MRI) study in two cases demonstrated fibrosis under or just proximal to the tarsal tunnel.

Results

The contractures were relieved by performing a tenolysis proximal to the medial malleolus. The operative findings demonstrated that the etiology could be possibly associated with a localized subclinical compartment syndrome.

Conclusions

We described five patients with a claw toe deformity following a tibia fracture associated with adhesions of the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) muscles to the surrounding structures under or just proximal to the flexor retinaculum. It is the authors’ opinion that this condition may be related to a subclinical compartment syndrome localized in the distal part of the deep posterior compartment. Soft-tissue release without tendon lengthening allowed recovery in all patients.
Women's Rights, Nationalist Anxiety, and the “Moral” Agenda in the Early Weimar Republic: Revisiting the “Black Horror” Campaign against France's African Occupation Troops
Authors: Roos Julia
Published: August 2009

In the months and years following ratification of the Versailles Treaty, the Allied occupation of the Rhineland became a focal point of German nationalist propaganda. The campaign against the so-called “black shame on the Rhine” (schwarze Schmach am Rhein), a racist slogan referring to the stationing of soldiers from northern Africa, Senegal, and Madagascar in the French zone of occupation, was one of the ugliest outgrowths of German opposition to the peace treaty. Support for the movement against France's African troops was disquietingly broad. An interpellation to the Reich government of May 1920 launched by the Majority Social Democrats (SPD) and endorsed by all parties in the national assembly except the Independent Socialists (USPD) is illustrative of the racist fears motivating “black horror” protests: “Even after the armistice, the French and Belgians continue to use colored troops in the occupied territories. … For German women and children, men and boys, these savages pose a horrifying danger. Their honor, health and life, purity and innocence are being destroyed. … This situation is disgraceful, humiliating, and insufferable!”
Billy Graham's America
Authors: Wacker Grant
Published: August 2009

Billy and I hit New York City at the same time, the summer of 1957. He was 38 and about to clinch his reputation as the premier evangelist in twentieth-century America. I was twelve and about to taste freedom. But not quite yet. Without my permission, my parents packed themselves and me into a steamy subway to go down to Madison Square Garden to hear the Great Man preach. I remember that he was witty and charismatic and at the end of the sermon thousands surged forward to give or recommit their lives to Christ. Beyond that, nothing stuck. Soon our first family vacation to the Big Apple was finished, and we headed back to the quiet of a small town in southwest Missouri. As a kid, I never could figure out what the big whoop over Graham was all about. I soon realized, however, that Graham's core constituents—the millions of preponderantly white, middle-class, moderately conservative Protestants we might call “Heartland Americans”—did not share my puzzlement. They knew exactly what the big whoop was all about.
“Family Values” and the Formation of a Christian Right Agenda
Authors: Dowland Seth
Published: August 2009

During his 1976 presidential campaign, Jimmy Carter promised social conservatives that, if elected, he would convene a conference examining how the federal government could support American families. That promise—alongside Carter's description of being “born again” and his well-documented Christian devotion—thrilled American evangelicals. They provided him with a crucial bloc of support in the 1976 election. Four years later, Carter finally made good on his campaign pledge when he convened the White House Conference on Families. Carter declared that the conference would “examine the strengths of American families, the difficulties they face, and the ways in which family life is affected by public policies.” He recruited a panel of organizers and asked them to focus on how government policy might better support family life.
The Limited Partnership in New York, 1822–1858: Partnerships Without Kinship
Authors: Hilt Eric , O'Banion Katharine
Published: August 2009

In 1822 New York became the first of many common law states to authorize the formation of limited partnerships. Little is known about the effects of these statutes. This article analyzes the use of the limited partnership in nineteenth-century New York City. We find that the form was adopted by a surprising number of firms, and that limited partnerships had more capital, failed at lower rates, and had fewer members with kinship ties, compared to ordinary partnerships. The results suggest that the introduction of the limited partnership facilitated investments that would not have occurred in the absence of the form.
Bonds and Brands: Foundations of Sovereign Debt Markets, 1820–1830
Authors: Flandreau Marc , Flores Juan H.
Published: August 2009

How does sovereign debt emerge? In the early nineteenth century, intermediaries' market power and prestige served to overcome information asymmetries. Relying on insights from finance theory, we argue that capitalists turned to intermediaries' reputations to guide their investment strategies. Intermediaries could in turn commit or else they would lose market share. This sustained the development of sovereign debt. This new perspective is backed by archival evidence and empirical data, and it suggests why strong but undemocratic states could borrow.

“A good name is worth more than a gem.”

Yiddish proverb
Towards an Objective Account of Nutrition and Health in Colonial Kenya: A Study of Stature in African Army Recruits and Civilians, 1880–1980
Authors: Moradi Alexander
Published: August 2009

This study presents fresh evidence on nutrition and health in colonial Kenya by using a new and comprehensive data set of African army recruits and civilians and applying a powerful measure of nutritional status: mean population height. Findings demonstrate huge regional inequalities, but only minor changes in the mean height of cohorts born 20 years before and after colonization. From 1920 onwards secular improvements took place, which continued after independence. I conclude that however bad colonial policies and devastating short-term crises were, the net outcome of colonial times was a significant progress in nutrition and health.
Fiscal Crisis and Institutional Change in the Ottoman Empire and France
Authors: Balla Eliana , Johnson Noel D.
Published: August 2009

Why is it that some countries adopted growth enhancing institutions earlier than others during the early modern period? We address this question through a comparative study of the evolution of French and Ottoman fiscal institutions. During the sixteenth century, both countries made extensive use of tax farming to collect revenue, however, uncertain property rights caused by fiscal pressure led to different paths of institutional change in each state. In France, tax collectors successfully overcame the collective action costs of imposing constraint on the king. In the Ottoman Empire, tax collectors faced prohibitive transaction costs to organizing in a similar manner.
Was Germany Ever United? Evidence from Intra- and International Trade, 1885–1933
Authors: Wolf Nikolaus
Published: August 2009

When did Germany become economically integrated? Based on a large new data set on trade flows within and across the borders of Germany, I explore the geography of trade costs across Central Europe, 1885–1933. The key finding is that the German Empire before 1914 was a poorly integrated economy. This internal fragmentation resulted from cultural heterogeneity, from administrative borders, and from natural geography that divided Germany into eastern and western parts. After World War I and again with the Great Depression, internal integration improved, while external integration worsened in part because of border changes along the lines of ethnolinguistic heterogeneity. By the end of the Weimar Republic in 1933, Germany was reasonably well integrated.