bluuebunny/crossref_metadata_2025 huggingface dataset:
Copolymerization of Ethylene and 10‐Undecen‐1‐ol using a Montmorillonite‐Intercalated Metallocene Catalyst: Synthesis of Polyethylene/Montmorillonite Nanocomposites with Enhanced Structural Stability
Authors: Huang Yingjuan , Yang Kefang , Dong Jin‐Yong
Published: July 2006

Summary: Ethylene and 10‐undecen‐1‐ol have been successfully copolymerized by an organically modified montmorillonite (OMMT)‐intercalated metallocene catalyst, Et[Ind]2ZrCl2, activated by methylaluminoxane (MAO). The obtained hydroxy‐functionalized polyethylene (PE‐OH)/OMMT nanocomposites exhibit enhanced structural stability as compared with the neat PE‐based ones, with no significant collapse of the nanocomposite structure being detected by WAXD examination after high‐temperature processing. The simultaneous polyolefin functionalization provides an effective and convenient solution to stabilize the PE/MMT nanocomposite structure formed by in‐situ polymerization.

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An Extremely Narrow‐Band‐Gap Conjugated Polymer with Heterocyclic Backbone and its Use in Optoelectronic Devices
Authors: Xia Yangjun , Deng Xianyu , Wang Li , Li Xianzhen , Zhu Xuhui , Cao Yong
Published: July 2006

Summary: A novel narrow‐band‐gap conjugated polymer with heterocyclic backbone, poly[4,7‐bis(4‐decanyl‐2‐thienyl)‐2′,1′,3′‐benzothiadiazole‐thiophene‐2,5‐] (PDDBT, Eg = 1.38 eV) was synthesized by a Stille coupling reaction. Prototype bulk heterojunction photovoltaic cells from PDDBT and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) with a ITO/PEDOT:PSS/PDDBT:PCBM(1:3)/Ba/Al device architecture showed power conversion efficiencies up to 0.13% under AM1.5 solar simulator (100 mW · cm−2) with an open‐circuit voltage Voc of 0.65 V, a short‐circuit current density Jsc of 0.6 mA · cm−2, and a photocurrent response up to 880 nm. The electroluminescent device from PDDBT showed a near‐infrared light emission peak at around 830 nm with maximal external quantum efficiency of 0.08% and a turn‐on voltage at 3.5 V.

Normalized PL and EL spectra of PDDBT and photosensitivity of PVCs based on PDDBT/PCBM (1:3) blend. The scheme shows the chemical structure of PDDBT.

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Normalized PL and EL spectra of PDDBT and photosensitivity of PVCs based on PDDBT/PCBM (1:3) blend. The scheme shows the chemical structure of PDDBT.
Preparation of Functionalized Polysilsesquioxane and Polysilsesquioxane‐Metal Nanoparticle Composite Spheres
Authors: Kim Young Baek , Kim Young‐A. , Yoon Kyung‐Sup
Published: July 2006

Summary: Network polysilsesquioxane spheres made solely of poly(vinylsilsesquioxane) (PVSQ) and poly(3‐mercaptopropylsilsesquioxane) (PMPSQ) were prepared from heterogeneous mixtures of triethylamine (TEA), water, and either vinyltrimethoxysilane (VTMS), or 3‐mercaptopropyltrimethoxysilane (MPTMS). The microscopic, macroscopic observations, and the relationship between the diameters of spheres and the amount of each ingredient in the reaction system, showed that spheres formed via a mechanism similar to emulsion polymerization and suspension polymerization, depending on the reaction conditions. Diameters of spheres could be controlled from tens of nanometers to a few micrometers by adjusting the amounts of TEA, water, and a surfactant. Heating aqueous solutions of metal ions with these spheres produced polysilsesquioxanes (PSQ)‐metal nanoparticle composite spheres. The spheres prepared in this study were characterized by scanning electron microscopy, transmission electron microscopy, solid state NMR spectroscopy, IR spectroscopy, elemental analysis, and differential thermal analysis. These spheres would be useful in recovering metals from their ionic solutions and probes after chemical modifications.

An image of the spheres of poly(vinylsilsesquioxane)‐gold nanoparticle composite.

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An image of the spheres of poly(vinylsilsesquioxane)‐gold nanoparticle composite.
Generation of Hierarchical Topologies from Photocrosslinkable, Particle‐Stabilized Emulsions
Authors: Benkoski Jason J. , Hu Hua , Karim Alamgir
Published: July 2006

Summary: We describe a way to obtain biomimetic, hierarchical surface morphologies. In order to mimic natural surfaces more accurately such as lotus leaves and gecko feet, we employ a strategy that bears many of the attractive characteristics of natural materials synthesis. The system in question consists of a photocurable monomer and water. To this quasi‐two‐component system we add polymer latex spheres. The monomer–water interface is then manipulated according to the well‐established science of complex fluids. Drawing from the rich phase behavior of particle‐stabilized emulsions, we demonstrate the creation of complex biomimetic morphologies over many length scales. The resulting structures are then solidified by crosslinking the monomer with UV light.

Comparison of an AFM image of a PMMA colloidosome assembly with that of the textured surface of a superhydrophobic Hygoryza aristata leaf (inset).

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Comparison of an AFM image of a PMMA colloidosome assembly with that of the textured surface of a superhydrophobic Hygoryza aristata leaf (inset).
Preparation of Robust Poly(ε‐caprolactone) Hollow Spheres with Controlled Biodegradability
Authors: Shi Zengqian , Zhou Yongfeng , Yan Deyue
Published: July 2006

Summary: This work reports a new type of poly(ε‐caprolactone) (PCL) robust hollow sphere with controllable biodegradability, produced by grafting PCL shells from the surface of silica sphere cores and removing the template cores. Bis(ε‐caprolactone‐4‐yl) (BCY) composed of two ε‐caprolactone molecules was used as the crosslinker, which not only greatly strengthened the PCL hollow spheres but also brought hardly any non‐biodegradable component into the system. Solubility experiments and biodegradation tests show that the crosslinked PCL hollow spheres were robust both in water and acetone, and were completely biodegradable with characteristics of controllable biodegradability according to the content of the BCY. The Rhodamine release test indicated that the release rate of encapsulated drugs in the PCL hollow spheres was controlled by diffusion and the biodegradability of the PCL molecules, and the latter mechanism will dominate when more enzymes are involved.

Reaction scheme for synthesis of linear and crosslinked hollow poly(ε‐caprolactone) spheres.

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Reaction scheme for synthesis of linear and crosslinked hollow poly(ε‐caprolactone) spheres.
Cover Picture: Macromol. Theory Simul. 6/2006
Authors: Carbone Paola , Rapallo Arnaldo , Ragazzi Massimo , Tritto Incoronata , Ferro Dino R.
Published: July 2006

Cover: Molecular models accurately reflecting the microstructure of real samples of ethylene‐norbornene copolymers are built up following the assignments, at tetrad level, of their 13C NMR spectra. By means of molecular dynamics simulations the relation among microstructure and thermal properties has been investigated. Further details can be found in the article by P. Carbone,* A. Rapallo, M. Ragazzi, I. Tritto, and D. R. Ferro on page 457.
Association between ulcerative growth and hypoxia inducible factor‐1α polymorphisms in colorectal cancer patients
Authors: Fransén Karin , Fenech Matthew , Fredrikson Mats , Dabrosin Charlotta , Söderkvist Peter
Published: July 2006

The hypoxia inducible factor‐1α (HIF‐1α) has been found to be involved in several different physiological mechanisms, such as blood‐vessel formation, apoptosis, and erythropoiesis. HIF‐1α is hydroxylated at normoxia and rapidly degraded via the von Hippel–Lindau (VHL)/ubiquitin‐proteasome degradation system to prevent angiogenesis. In a previous study, the C1772T (P582S) and the G1790A (A588T) polymorphisms were identified in the human HIF‐1α gene, which was shown to have a higher transactivating capability in vitro compared to the wild type allele. However, the role for these polymorphisms in vivo is still unclear. In the present investigation, we have therefore studied the role of the two polymorphic variants in the development of colorectal cancer (CRC) with PCR/RFLP (restriction fragment length polymorphism), single strand conformation analysis (SSCA), and immunohistochemistry (IHC). A significant higher‐risk was identified between patients heterozygous for the C1772T polymorphism and the more severe ulcerative growth pattern compared to homozygous C1772C wild type tumors (RR = 5.2; 95% CI 1.26–21.6; P = 0.006). This was also verified on the allelic level (RR = 6.5; 95% CI 1.58–26.8; P = 0.001). In addition, patients carrying one or more polymorphic alleles in either the HIF‐1α C1772T or the G1790A polymorphisms display significant higher risk for the development of ulcerative CRCs (RR = 4.17; 95% CI = 1.33–13.08; P = 0.004). These results suggest that the HIF‐1α polymorpisms are an important factor for development of a subset of ulcerative intestinal tumors. Future screening of the polymorphic HIF‐1α allele may therefore be of importance in the selection of treatment strategies of CRC. © 2006 Wiley‐Liss, Inc.
Diversity of contactin mRNA in human brain tumors
Authors: Rome Claire , Loiseau Hugues , Arsaut Josette , Roullot Valérie , Couillaud Franck
Published: July 2006

In order to address the molecular signature of human glioma, we investigated the polymorphism of 5′UTR of the mRNA of Contactin, an adhesion molecule which plays a role in the invasive behavior of these tumors. Contactin mRNA is identified by RT‐PCR and a strategy based on rapid amplification of cDNA ends (RACE) reveals different 5′UTRs resulting from both an alternative use of two types of leader exons and a splicing mechanism within the 5′UTR. The spliced exon is an Alu‐containing element specific to the primate lineage, thus indicating a recent evolution of regulatory processes specific to the simian line that occurs on this gene. Each 5′UTR exhibits different transcription/translation efficiencies and contains features that allow translation to occur independently of the classic cap‐dependent mechanism. These data illustrate the complex regulation of Contactin expression in human brain tumors occurring at both transcriptional and translation levels. The different 5′UTRs are differentially expressed in diverse types of human tumors. Thus, the polymorphism occurring within the non‐coding part of the contactin mRNA reveals new opportunities to explore deregulation that occurs during the oncogenic process. © 2006 Wiley‐Liss, Inc.
The impact of oocyte maturation media on early bovine embryonic development
Authors: Russell D. Fischer , Baqir S. , Bordignon J. , Betts D.H.
Published: July 2006

Successful production of high quality blastocysts in vitro depends on the use of a culture system that ensures the acquisition of developmental competence by the maturing oocyte. It is now clear that the in vitro maturation environment has a major influence on the oocyte's ability to acquire the potential to develop into blastocysts. In this work we examine the impact of oocyte culture media on the quality of blastocysts by comparing developmental rates, cell number and their allocation to embryonic cell lineages, apoptosis, and expression of developmentally important genes. Higher total cell count and ICM:TCN ratio, which are indicative of embryo viability, were observed in embryos derived from oocyte maturation in TCM‐199 supplemented with serum when compared to blastocysts derived from oocyte maturation in SOF BSA. Moreover, oocyte maturation in TCM‐199 supplemented with serum‐generated embryos of higher morphological quality and producing higher levels of Interferon Tau transcripts when compared to embryos derived from oocyte maturation in SOF BSA. In conclusion, the oocyte maturation regimen affected the morphological feature of blastocysts, including total cell count and allocation of cells to trophectoderm (TE) and inner cell mass (ICM) lineages and the expression profiles of genes involved in various embryo functions such as early embryonic growth, regulation of gene transcription, trophoblast differentiation and function, embryo‐maternal communication, and stress response. Our results show that the oocyte culture media have strong impact on the quality of embryos produced in vitro and emphasize the need for more in depth evaluation of oocyte maturation protocols. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Remodeling of extracellular matrix at ovulation of the bovine ovarian follicle
Authors: Irving‐Rodgers H.F. , Catanzariti K.D. , Aspden W.J. , D'Occhio M.J. , Rodgers R.J.
Published: July 2006

Using immunohistochemistry and RNA analyses we examined the fate of components of a newly identified matrix that develops between granulosa cells (focimatrix, abbreviated from focal intraepithelial matrix) and of the follicular basal lamina in ovulating bovine ovarian follicles. Pre‐ and postovulatory follicles were generated by treatment with estradiol (Day 1), progesterone (Days 1–10), and prostaglandin analogue (Day 9) with either no further treatment (Group 1, n = 6) and or with 25 mg porcine LH (Day 11, Group 2, n = 8 or Day 10, Group 3, n = 8) and ovariectomy on Day 12 (12–14 hr post LH in Group 2, 38–40.5 hr in Group 3). In the time frame examined no loss of follicular basal lamina laminin chains β2 and γ1 or nidogen 1 was observed. In the follicular basal lamina collagen type IV α1 and perlecan were present prior to ovulation; after ovulation collagen type IV α1 was discontinuously distributed and perlecan was absent. Versican in the theca interna adjacent to the follicular basal lamina in preovulatory follicles was not observed post ovulation, however, the granulosa cells then showed strong cytoplasmic staining for versican. Expression of versican isoforms V0, V1, and V3 was detected at all stages. Focimatrix was observed in preovulatory follicles. It contained collagen type IV α1, laminins β2 and γ1, nidogen 1 and perlecan and underwent changes in composition similar to that of the follicular basal lamina. In conclusion focimatrix and the follicular basal lamina are degraded at ovulation. Individual components are lost at different times. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Public policy management councils in Brazil: how far does institutionalised participation reach?
Authors: Barth J.
Published: July 2006

During the past two decades, Brazil has experienced a wide range of new participatory management instruments. One of the most important are the so called public policy management councils, composed of governmental and non‐governmental members, which have been implemented mainly in social sectors in order to discuss and develop public policies as well as to decide on the allocation of public funds. The practice shows that several structural factors still limit the potential of such a form of institutionalised participation. The most innovative result is without doubt the contribution towards transforming political culture, a prerequisite for the success of the ongoing democratisation process in most of the Latin American countries. Copyright © 2006 John Wiley & Sons, Ltd.
A perspective on road sector restructuring in developing and transitional countries
Authors: Robinson Richard
Published: July 2006

A model derived within the World Bank sought to characterise how road administrations had evolved over time from large public works organisations to lean network administrators, working at arms‐length from government and making extensive use of contracts. The paper shows how two other pieces of work in this area help to explain why the evolution tends to happen in the manner identified. The first study concluded that a hierarchy of factors had to be addressed if organisational reform is to be successful: external factors need to be addressed to ensure that the context for restructuring is appropriate before attempting managerial and then technical changes within an organisation. The second study identified that, to achieve organisational effectiveness and efficiency, there is a need to increase the ‘specificity’ of the organisation and to subject it to competition. These factors explain the evolutionary model, with the initial stages of evolution tending to increase the specificity of the organisation, with the later stages subjecting more activities to competition. The evolutionary model was developed by observing how the restructuring process had progressed in countries such as New Zealand and the United Kingdom. However, the experience of restructuring in Romania is also summarised, confirming that the model also applies to countries making the transition to a market economy. The impact of administrative decentralisation on road sector performance is considered, and the types of decentralisation are identified offering the most promise in terms of sector restructuring. The combination of the results from these pieces of work provide a simple framework for understanding transition and restructuring in the road sector that can be used as the basis for developing restructuring plans. The approach is entirely consistent with the principles of the New Public Management, and there appears to be no reason why it should not be applied in other sectors wishing to restructure. Copyright © 2006 John Wiley & Sons, Ltd.
Long‐term telephone therapy outcomes for breast cancer patients
Authors: Sandgren Ann K. , McCaul Kevin D.
Published: July 2006

We present the results of a breast cancer clinical trial that tested two therapy interventions delivered by telephone. Women (N=218) with Stages I, II, or III breast cancer were randomly assigned to breast cancer health education or emotional expression interventions, or to a standard care control condition. Outcome and process measures were obtained at baseline, 6‐month and 13‐month follow‐ups. Oncology certified nurses conducted the therapies in six, 30‐minute individual phone sessions. Women in the health education condition reported significantly better knowledge and less perceived stress compared to women in the emotional expression and control conditions. No treatment effects, however, were obtained for quality of life or mood, and all women generally improved on these measures over time. Secondary analyses showed that younger women and women with a more advanced stage of breast cancer reported significantly greater avoidant coping. The data show that telephone therapy is a viable delivery modality and that distress improves with time for most women. Overall, this study showed that neither of the two telephone interventions tested had a meaningful effect on quality of life or mood. Copyright © 2006 John Wiley & Sons, Ltd.
Comparison of Predictivities of Log P Calculation Models Based on Experimental Data for 134 Simple Organic Compounds
Authors: Sakuratani Yuki , Kasai Kenji , Noguchi Yoshiyuki , Yamada Jun
Published: July 2006

Predictivities of six log P calculation models (CLOGP, KOWWIN, ACD/LOGP, SLOGP, VLOGP and COSMO thermo) are compared using a common experimental dataset, which does not contain any of the compounds used in the training set for the six models. The former three models, which are based on fragment methods, showed better accuracy (r=0.87–0.91) than SLOGP, which is based on the atom contribution method and VLOGP and COSMO thermo, which are property‐based models. The trends of prediction by each model are described based on chemical structure and molecular weight. For all six models, several compounds had a significantly greater calculated log P value than the experimental log P value. It is interesting to note that most of these compounds had ionic moieties.
Recurrence relations for fully correlated Gaussians with odd powers of interparticle coordinates
Authors: Harris Frank E. , Monkhorst Hendrik J.
Published: July 2006

It is shown that the recurrence relations previously derived by the present authors, connecting fully correlated Gaussians to which even powers of the interparticle distances have been appended, are also applicable when these distances appear as odd powers. Implications of this demonstration for the description of electron correlation in few‐body systems are also reviewed. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
CCSD(T), W1, and other model chemistry predictions for gas‐phase deprotonation reactions
Authors: Pickard Frank C. , Griffith Daniel R. , Ferrara Skylar J. , Liptak Matthew D. , Kirschner Karl N. , Shields George C.
Published: July 2006

A series of CCSD(T) single‐point calculations on MP4(SDQ) geometries and the W1 model chemistry method have been used to calculate ΔH° and ΔG° values for the deprotonation of 17 gas‐phase reactions where the experimental values have reported accuracies within 1 kcal/mol. These values have been compared with previous calculations using the G3 and CBS model chemistries and two DFT methods. The most accurate CCSD(T) method uses the aug‐cc‐pVQZ basis set. Extrapolation of the aug‐cc‐pVTZ and aug‐cc‐pVQZ results yields the most accurate agreement with experiment, with a standard deviation of 0.58 kcal/mol for ΔG° and 0.70 kcal/mol for ΔH°. Standard deviations from experiment for ΔG° and ΔH° for the W1 method are 0.95 and 0.83 kcal/mol, respectively. The G3 and CBS‐APNO results are competitive with W1 and are much less expensive. Any of the model chemistry methods or the CCSD(T)/aug‐cc‐pVQZ method can serve as a valuable check on the accuracy of experimental data reported in the National Institutes of Standards and Technology (NIST) database. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Correlated, relativistic, and basis set limit molecular polarizability calculations to evaluate an augmented effective core potential basis set
Authors: Labello Nicholas P. , Ferreira Antonio M. , Kurtz Henry A.
Published: July 2006

Initial investigations have demonstrated that an augmented ECP basis set can be used to calculate valence electronic properties with deviations of less than 1% from all‐electron basis sets. Past work has largely focused on molecules with relatively light atoms (Z<18) examined with time‐dependent Hartree–Fock (TDHF) theory. In this work, the dipole moment and polarizability of a number of well‐studied molecules are examined with HF, MP2, CCSD, and CCSD(T) correlated wave functions. Additionally, systems not as thoroughly studied due to the difficulty of all‐electron calculations when Z=50–85 are included. The SBK ECP basis set, augmented with optimized valence functions, performs well across a broad range of methods, less than 3% different from all electron relativistic and correlated wave functions. Orders of magnitude time savings (101–104) are exchanged for a minimal difference from all‐electron basis sets. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
In vacuo isotope coded alkylation technique (IVICAT); an N‐terminal stable isotopic label for quantitative liquid chromatography/mass spectrometry proteomics
Authors: Simons Brigitte L. , Wang Guanghui , Shen Rong‐Fong , Knepper Mark A.
Published: July 2006

We present a new isotopic labeling strategy to modify the N‐terminal amino group of peptides in a quantifiable reaction without the use of expensive reagents or solvents. The In Vacuo Isotope Coded Alkylation Technique (IVICAT) is a methylation reaction, carried out at low pressure (<100 mTorr), that results in a stable quaternary trimethylammonium group, thus adding a permanent positive charge at the N‐terminus of peptides without modifying the ε‐amino groups of lysine. The methylation reaction increases the signal intensity of modified peptides in matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) and liquid chromatography (LC)/MS and the isotopic peak pair differs by 9 mass units which can be easily resolved by either instrument. N‐terminally trimethylated peptides exhibit collision‐induced dissociation (CID) mass spectra that differ from their unmodified analogues by an enhanced b‐ion series in MS2 spectra due to the fixed positive charge. Using LC/MS/MS with an LTQ mass analyzer for quantification, the experimentally determined ratios of H9‐ to D9‐trimethyl‐labeled peptides of β‐casein provided accurate estimates of the actual ratios with low % error. IVICAT labeling also accurately quantified proteins in rat kidney inner medullary collecting duct cell types, as judged by comparison with relative quantification by subsequent immunoblotting experiments. IVICAT labeling, when used in conjunction with the new proteomics software QUIL, can accurately report relative protein abundances and increase the sequence coverage of proteins of tissue proteomes. Published in 2006 by John Wiley & Sons, Ltd.
Three‐dimensional evaluation of mid‐facial hypoplasia in fetuses with trisomy 21 at 11 + 0 to 13 + 6 weeks of gestation
Authors: Dagklis T. , Borenstein M. , Peralta C. F. A. , Faro C. , Nicolaides K. H.
Published: July 2006

Objective

To investigate the mid‐facial hypoplasia of fetuses with trisomy 21 at 11 + 0 to 13 + 6 weeks of gestation, by three‐dimensional (3D) evaluation of the maxilla and the nasal bones.

Methods

A 3D volume of the fetal head was obtained before fetal karyotyping at 11 + 0 to 13 + 6 (median 12) weeks of gestation in 80 fetuses that were subsequently found to have trisomy 21 and in 862 fetuses subsequently found to be chromosomally normal. The multiplanar mode was used to obtain a sequence of transverse views of the fetal face and to demonstrate the maxilla, the adjacent rami of the mandible and the nasal bones. The maxillary depth, defined as the distance between the alveolus of the maxilla in the midline anteriorly and the midpoint of the line joining the rami posteriorly, was measured. Ossification of the nasal bones was considered to be normal if both bones were more echogenic than the overlying skin.

Results

In the chromosomally normal group the maxillary depth increased linearly with crown–rump length (CRL) from 3.1 mm at a CRL of 45 mm to 4.8 mm at a CRL of 84 mm, and in the trisomy 21 fetuses the depth was significantly smaller than normal (mean difference = − 0.3 mm, P < 0.001). There was no significant association between the delta maxillary depth and delta nuchal translucency thickness in either the trisomy 21 or the chromosomally normal fetuses. Impaired ossification of the nasal bones was observed in 3.1% of the chromosomally normal fetuses and in 60.0% of those with trisomy 21. The mean maxillary depth was significantly smaller in fetuses demonstrating impaired ossification than in those with normal ossification of the nasal bones (mean difference = −0.2 mm; 95% CI, −0.3 to −0.1, P = 0.001).

Conclusions

In a high proportion of fetuses with trisomy 21 there is sonographic evidence of mid‐facial hypoplasia at 11 + 0 to 13 + 6 weeks of gestation. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Radio frequency identification: technologies, applications, and research issues
Authors: Xiao Yang , Yu Senhua , Wu Kui , Ni Qiang , Janecek Christopher , Nordstad Julia
Published: July 2006

A radio frequency identification (RFID) system is a special kind of sensor network to identify an object or a person using radio frequency transmission. A typical RFID system includes transponders (tags) and interrogators (readers): tags are attached to objects/persons, and readers communicate with the tags in their transmission ranges via radio signals. RFID systems have been gaining more and more popularity in areas such as supply chain management, automated identification systems, and any place requiring identifications of products or people. RFID technology is better than barcode in many ways, and may totally replace barcode in the future if certain technologies can be achieved such as low cost and protection of personal privacy. This paper provides a technology survey of RFID systems and various RFID applications. We also discuss five critical research issues: cost control, energy efficiency, privacy issue, multiple readers' interference, and security issue. Copyright © 2006 John Wiley & Sons, Ltd.
A client‐side design and implementation for push to talk over cellular service
Authors: Wu Lin‐Yi , Tsai Meng‐Hsun , Lin Yi‐Bing , Yang Jen‐Shun
Published: July 2006

This paper proposes a client architecture for the push to talk over cellular (PoC) service based on the open mobile alliance (OMA) PoC specifications v1.0 release. We show that most standard VoIP modules can be reused for the PoC client, and the VoIP software can be easily extended to support PoC service. Then we present the detailed message flows between the PoC client and other network entities in the PoC system. A PoC client prototype has been implemented in the Industrial Technology Research Institute (ITRI) and National Chiao‐Tung University (NCTU) Joint Research Center. Copyright © 2006 John Wiley & Sons, Ltd.
Shielding TCP from last hop wireless losses
Authors: Vangala Sarma , Labrador Miguel A.
Published: July 2006

The pervasiveness of the transport control protocol (TCP) and the proliferation of wireless local area networks (WLAN) of the 802.11 type make the topic of TCP performance over last hop wireless networks very relevant. The Snoop protocol, a link layer solution introduced several years ago to improve the performance of TCP in this scenario, has been shown to neglect its benefits to the most widely used TCP version, TCP SACK. In this paper, we introduce the TCP SACK‐Aware Snoop protocol to address this problem. Our results indicate that the TCP SACK‐Aware Snoop protocol improves the performance of TCP SACK by around 30% compared with the original Snoop protocol and by about 8% in an environment where no TCP enhancing mechanism is in place. In addition, we introduce further modifications to the proposed protocol to make its advantages available to any TCP sender. We also show that the mechanism does not introduce unfairness among TCP sources and somewhat protects TCP against UDP traffic. Our results show important throughput improvements to all TCP versions and demonstrate that the TCP SACK‐Aware Snoop protocol shields TCP from last hop wireless losses providing throughtput values very close to the maximum possible. Copyright © 2006 John Wiley & Sons, Ltd.
Polyamine deficiency leads to accumulation of reactive oxygen species in a spe2Δ mutant of Saccharomyces cerevisiae
Authors: Chattopadhyay Manas K. , Tabor Celia White , Tabor Herbert
Published: July 2006

We have previously shown that polyamine‐deficient Saccharomyces cerevisiae are very sensitive to incubation in oxygen. The current studies show that, even under more physiological conditions (i.e. growth in air), polyamine‐deficient cells accumulate reactive oxygen species (ROS). These cells develop an apoptotic phenotype and, after incubation in polyamine‐deficient medium, die. To show a specific effect of polyamines on ROS accumulation, uncomplicated by any effects on growth, spermine was added to spermidine‐deficient spe2Δ fms1Δ cells, since spermine does not affect the growth of this strain. In this strain, spermine addition caused a marked, but not complete, decrease in the accumulation of ROS and a moderate protection against cell death. In other experiments with polyamine‐deficient cells containing plasmids that overexpress superoxide dismutases (SOD1, SOD2), ROS decreased but with only a partial protection against cell death. Polyamine‐deficient cells incubated anaerobically show markedly less cell death. These data show that part of the function of polyamines is protection of the cells from accumulation of ROS. Copyright © 2006 John Wiley & Sons, Ltd.
Risk Reduction Behaviors and Provider Communication Following Genetic Counseling and BRCA1 Mutation Testing in an African American Kindred
Authors: Kinney Anita Yeomans , Simonsen Sara Ellis , Baty Bonnie Jeanne , Mandal Diptasri , Neuhausen Susan L. , Seggar Kate , Holubkov Richard , Bloor Lindsey , Smith Ken
Published: July 2006

Little is known about the impact of cancer genetic counseling and testing on health behaviors in racial and ethnic subgroups. This prospective observational study examined use of risk reduction strategies following BRCA1 counseling and testing. Participants were female members of an African American kindred who received genetic education, counseling and testing (n = 40) and completed a 1‐year follow‐up interview. Mutation carriers were more likely to opt for breast (100%, 7/7) and ovarian (25%; 1 of 4) cancer surveillance than prophylactic surgery. Following genetic counseling, 71% (5/7) of the BRCA1 carriers who opted for surveillance reported having a mammogram within the year following receipt of their genetic test results. Ovarian cancer screening among mutation carriers increased from 0% at baseline to 25% (one of four) at 1 year. Compared to noncarriers (23%, 7/30), carriers (70%, 7/10) were more likely to discuss their BRCA1 test results with their primary health care providers. Surveillance for breast cancer was preferred to prophylactic surgery and chemoprevention as a way to reduce risk for these cancers. Our data indicate that patient‐provider communication about BRCA1 test results is suboptimal.
Predictive Testing of Eighteen Year Olds: Counseling Challenges
Authors: Gaff Clara L. , Lynch Elly , Spencer Lesley
Published: July 2006

Genetic counseling of teenagers is challenging and complex. The ability to think abstractly, a sense of self and independence from family all develop during adolescence. Predictive genetic testing counseling protocols presuppose that these qualities exist, requiring the at‐risk individual to consider the short and long term consequences of testing as well as their motivations. Eighteen year olds are in transition from adolescence to adulthood; eligible for predictive genetic testing, they may not yet be independent of their family or able to articulate their feelings. This paper presents case studies from the authors’ clinical practice to illustrate some of the difficulties faced by genetic counselors when 18 year olds request predictive testing for Hereditary Non‐Polyposis Colorectal Cancer. By reflecting upon their experiences with these young adults and their families, the authors’ intention is to generate discussion about genetic counseling strategies, particularly for predictive genetic testing, that are both age‐appropriate and family‐sensitive.
Self-organization of quantum-dot pairs by high-temperature droplet epitaxy
Authors: Wang Zhiming M. , Holmes Kyland , Mazur Yuriy I. , Ramsey Kimberly A. , Salamo Gregory J.
Published: July 2006

The spontaneously formation of epitaxial GaAs quantum-dot pairs was demonstrated on an AlGaAs surface using Ga droplets as a Ga nano-source. The dot pair formation was attributed to the anisotropy of surface diffusion during high-temperature droplet epitaxy.
Relations between alcohol, violence and victimization in adolescence
Authors: Shepherd J.P. , Sutherland I. , Newcombe R.G.
Published: July 2006

Background

Compared to links between alcohol and aggression, links between alcohol and vulnerability are poorly understood.

Objectives

To determine whether there is a significant relationship between vulnerability to physical violence and alcohol consumption in adolescence independent of a relationship between alcohol consumption and violent behaviour.

Design, setting, participants

Cross‐sectional study of 4187 adolescents aged 11–16 in a stratified sample of 13 English schools.

Results

Fighting decreased with age whereas hitting others and being hit increased. Relationships between fighting, hitting others and vulnerability to being hit and frequency of drinking and drunkenness were all highly significant (), and were evident at all ages. The outcome most strongly related to frequency of drunkenness was hitting others (odds ratio (OR) 6.62), followed by being hit (OR 4.01) and fighting (OR 2.10). Alcohol consumption and drunkenness remained significantly and independently associated with vulnerability to being hit after adjusting for violent behaviour as well as age and sex.

Conclusions

These findings indicate an association between alcohol and victimization independent of associations of both with physical aggression. Reducing intoxication may reduce victimisation without necessarily affecting violent behaviour. Violence reduction should focus as much on preventing alcohol misuse among victims or potential victims as among offenders.
A quartet of lateral sinus thrombosis, extradural abscess, subdural abscess and occipital abscess: complications of acute mastoiditis in a pre-adolescent child
Authors: Charlett S D , Moor J W , Jenkins C N , Coatesworth A P
Published: July 2006

Neurological complications of acute mastoiditis are rare but can be life threatening. Their presentation may be masked by the use of antibiotics. We present a unique case of acute otitis media progressing to occipital, extradural and subdural abscess formation and lateral sinus thrombosis in a child. The clinical course and management of a pre-adolescent male is presented and discussed. We review the incidence, presentation and treatment of occipital abscesses and lateral sinus thrombosis with acute mastoiditis. Following extended cortical mastoidectomy, neck exploration and broad spectrum intravenous antibiotics, the patient made a full recovery. This is the first reported case of acute mastoiditis associated with occipital abscess in a child. Early, aggressive treatment is required for a successful outcome. The rarity of neurological complications, in addition to the insidious onset and subtle symptoms associated with antibiotic therapy, can make diagnosis extremely difficult. Patients with acute otitis media who fail to respond fully to treatment should be referred early for a specialist otology opinion.
Transport barriers with magnetic shear in a tokamak
Authors: EL MOUDEN M. , SAIFAOUI D. , DEZAIRI A. , ZINE B. , EDDAHBY M.
Published: July 2006

The reversed magnetic shear is the most important factor in the study of the plasmas of a tokamak. In this paper we focus our research, as a first stage, on the control of the improved confinement regimes by studying the influence of the reversed shear on its quality in the plasma of a tokamak and especially in reducing the anomalous transport in ITER. Then we study the influence of the perturbation modes on the particle diffusion. At the end, a comparison between simulation results obtained using ITER and TEXT parameters is carried out.
Dispersion in a relativistic degenerate electron gas
Authors: McORIST J. , MELROSE D. B. , WEISE J. I.
Published: July 2006

Relativistic effects on dispersion in a degenerate electron gas are discussed by comparing known response functions derived relativistically and non-relativistically. The main distinguishing feature is one-photon pair creation, which leads to logarithmic singularities in the response functions. Dispersion curves for longitudinal waves have a similar tongue-like appearance in the relativistic and non-relativistic case, with the main relativistic effects being on the Fermi speed and the cutoff frequency. For transverse waves the non-relativistic treatment has a non-physical feature near the cutoff frequency for large Fermi momenta, and this is attributed to an incorrect treatment of the electron spin. We find (with two important provisos) that one-photon pair creation is allowed in superdense plasmas, implying relatively strong coupling between transverse waves and pair creation.
Targeted Oxygen Delivery within Hepatic Hollow Fiber Bioreactors via Supplementation of Hemoglobin‐Based Oxygen Carriers
Authors: Sullivan Jesse P. , Palmer Andre F.
Published: July 2006

Hepatic hollow fiber bioreactors are considered a promising class of bioartificial liver assist device (BLAD). Unfortunately, limited oxygen (O2) transport to hepatocytes within this device hinders further development. Hepatocytes in vivo (in the liver sinusoid) experience a wide range of oxygen tensions (pO2 = 25–70 mmHg), which is important for development of proper differentiated function (zonation). Previously, we observed that bovine red blood cell (bRBC) supplementation of the circulating media stream enhanced oxygenation of cultured C3A hepatoma cells compared to a culture with no O2 carrier (Gordon, J.; Palmer, A. F. Artif. Cells, BloodSubstitutes, Biotechnol. 2006, 33 (3), 297–306). Despite this success, the cells were not exposed to the desired in vivo O2 spectrum (Sullivan, J.; Gordon, J.; Palmer, A. Biotechnol. Bioeng. 2006, 93 (2) 306–317). We hypothesize that altering the kinetics of O2 binding/release to/from hemoglobin‐based O2 carriers (HBOCs) could potentially target O2 delivery to cell cultures. High P50 (low O2 affinity) HBOCs preferentially targeted O2 delivery at high inlet pO2 values. Conversely, low P50 (high O2 affinity) HBOCs targeted O2 delivery at low inlet pO2 values. Additionally, inlet pO2, flow rate, and HBOC concentration were varied to find optimal bioreactor operating conditions. Our results demonstrate that HBOCs can enhance O2 delivery to cultured hepatocytes, while exposing them to in vivo‐like O2 tensions, which is critical to create a fully functional BLAD.
Distinguishing Preterminal and Terminal Cognitive Decline
Authors: Sliwinski Martin J. , Stawski Robert S. , Hall Charles B. , Katz Mindy , Verghese Joe , Lipton Richard
Published: July 2006

This paper reviews different methodological approaches taken to examine terminal decline in cognitive function, and presents new findings from the Bronx Aging Study (BAS). Numerous approaches have been taken to assess mortality effects on cognition: comparing survivors and decedents level and rate of change in cognition, and identifying individual differences in cognition associated with time-to-death. However, few studies have actually modeled within-person change in cognition as a function of time-to-death. Using linear mixed models with a change point, intraindividual change in episodic memory was modeled as a function of both age and time-to-death. A dramatic increase in the rate of decline was identified at 8.4 years prior to death, providing clear evidence of a terminal-decline phase that is much longer than previously estimated. These results emphasize the importance of modeling the time course and effects of terminal cognitive decline for understanding cognitive change in aging adults.
Aging and Late-Life Terminal Decline in Perceptual Speed
Authors: Thorvaldsson Valgeir , Hofer Scott M. , Johansson Boo
Published: July 2006

Individual changes in perceptual speed were modeled as a conditional function of age and time-to-death. Alternative time-structured models were evaluated in a Swedish population-based, age-homogeneous sample (Gothenburg H70; N = 764) of individuals assessed at ages 70, 75, 79, 85, 88, 90, 92, 95, 97, and 99. Modeling time as proximity to death accounted better for the heterogeneity of individual changes than an age-based time structure. Time-to-death was a significant predictor of individual differences in rates of change in the age-based model but age did not significantly predict individual differences in rates of change in the model structured by proximity to death. In both the age-based and death-based time-structured models, accelerated changes prior to time of death were observed and provide support for the terminal-decline hypothesis. Identification of health-related factors and other sources of causal heterogeneity of aging-related change can make productive use of alternative time specifications that emphasize congruency between within-person change processes and aggregate population change.
Depth‐dependent rheology and the horizontal length scale of mantle convection
Authors: Lenardic A. , Richards M. A. , Busse F. H.
Published: July 2006

Numerical simulations show that depth‐dependent viscosity can increase the wavelength of mantle convection. The physical mechanism behind this phenomenon and its robustness with respect to model parameters remain to be fully elucidated. Toward this end, we develop theoretical heat flow scalings for a convecting fluid layer with depth‐dependent viscosity. Bottom and internally heated end‐members are considered. For the former, the viscosity structure consists of a high‐viscosity central region bounded from above and below by horizontal low‐viscosity channels. For internally heated cases, only a surface low‐viscosity channel is present. Theoretical scalings derived from boundary layer theory show that depth‐dependent rheology lowers the lateral dissipation associated with steady state convective rolls, allowing longer aspect ratio cells to form as the viscosity contrast between the channels and the central region is increased. The maximum cell aspect ratio is estimated from the condition that the pressure gradients that drive lateral flow in the channels do not become so large as to inhibit vertical flow into the channels. Scaling predictions compare favorably to results of numerical simulations for steady state cells. As the Rayleigh number driving convection is increased, small‐scale boundary layer instabilities begin to form. This increases lateral dissipation within the channels and the preferred cell aspect ratio decreases as a result. Internally heated simulations show that a near‐surface high‐viscosity layer, an analog to tectonic plates, can suppress these small‐scale instabilities. This allows a low‐viscosity channel to maintain large aspect ratio cells for Rayleigh numbers approaching that of the present‐day Earth.
Aftershock decay, productivity, and stress rates in Hawaii: Indicators of temperature and stress from magma sources
Authors: Klein Fred W. , Wright Tom , Nakata Jennifer
Published: July 2006

We examined dozens of aftershock sequences in Hawaii in terms of Gutenberg‐Richter and modified Omori law parameters. We studied p, the rate of aftershock decay; Ap, the aftershock productivity, defined as the observed divided by the expected number of aftershocks; and c, the time delay when aftershock rates begin to fall. We found that for earthquakes shallower than 20 km, p values >1.2 are near active magma centers. We associate this high decay rate with higher temperatures and faster stress relaxation near magma reservoirs. Deep earthquakes near Kilauea's inferred magma transport path show a range of p values, suggesting the absence of a large, deep magma reservoir. Aftershock productivity is >4.0 for flank earthquakes known to be triggered by intrusions but is normal (0.25 to 4.0) for isolated main shocks. We infer that continuing, post‐main shock stress from the intrusion adds to the main shock's stress step and causes higher Ap. High Ap in other zones suggests less obvious intrusions and pulsing magma pressure near Kilauea's feeding conduit. We calculate stress rates and stress rate changes from pre‐main shock and aftershock rates. Stress rate increased after many intrusions but decreased after large M7–8 earthquakes. Stress rates are highest in the seismically active volcano flanks and lowest in areas far from volcanic centers. We found sequences triggered by intrusions tend to have high Ap, high (>0.10 day) c values, a stress rate increase, and sometimes a peak in aftershock rate hours after the main shock. We interpret these values as indicating continuing intrusive stress after the main shock.