bluuebunny/crossref_metadata_2025 huggingface dataset:
Counterion and Diluent Effects on the Response of Ionic Polymer Transducers
Authors: Farinholt Kevin M. , Leo Donald J.
Published: March 2007

A parametric study is presented which investigates the effect that counterion and diluent have on the electrical and electromechanical response of the ionic polymer transducers (IPT). This series of experiments expands upon existing studies by incorporating the sensing and impedance characteristics of the ionic polymer in response to changes in the counterion species and the viscous and dielectric properties of the diluent. The counterions considered in this study include the monovalent and divalent metals Li+, Na +, Cs+, and Ca2+, as well as the larger organic cations tetraethylammonium (TEA+) and tetrabutylammonium (TBA +). Viscosity studies incorporate various water—glycerol mixtures which are tailored to yield viscosities from 1 cP (100% water) to 1500 cP (100% glycerol). Dielectric properties of the diluent are also considered in a study which compares the response of samples in water (78.4), acetonitrile (37.5), and butyl acetate (5.4). The results of these studies demonstrate the importance of the transducer's electrical response in regards to the electromechanical performance of the transducer in both actuation and sensing applications.
Bracing Systems for Installation of MR Dampers in a Building Structure
Authors: Lee Sang-Hyun , Min Kyung-Won , Chung Lan , Lee Sung-Kyung , Lee Myoung-Kyu , Hwang Jae-Seung , Choi Seung-Bok , Lee Ho-Guen
Published: March 2007

In this study, the effects of bracing systems for installing a magnetorheological (MR) damper in a building structure on seismic response control are analytically and experimentally investigated. The performance of the toggle brace system which enables the installed damper to generate larger effective control force due to its response amplification mechanism than a conventional brace system is evaluated. In addition, the nonlinear velocity amplification factor for the toggle brace—MR damper system and the effect of toggle configuration are considered. Analytical and experimental results show that control performance can be enhanced using the toggle brace system especially for the case in which the MR damper installed using non-amplifying brace system cannot provide sufficient response reduction.
Grain Orientation Scattering in Nonlinear Constitutive Modeling of Piezoelectric-ferroelectric Materials
Authors: Kushnir Uri , Rabinovitch Oded
Published: March 2007

The ability to enhance and to improve the efficiency of micromechanical models for the coupled electromechanical constitutive behavior of piezoelectric materials in the nonlinear regime is investigated. Motivated by the limited strain actuation capabilities of the existing piezoelectric materials and structures, it is recognized that the nonlinear regime has to be explored. However, due to the complex, strongly coupled, and hysteretic behavior of the material, the quantitative prediction of its nonlinear response requires complex and time-consuming algorithms. In this study, the ability to improve the efficiency of the micromechanical algorithm by using a deterministic set of directions as a representative of the scattering of grain's orientation within the piezoelectric polycrystal is investigated. Various types of deterministic grain sets that include an equal area, a spiral, and Fekete grain sets are examined. The constitutive micromechanical model for the piezoelectric material and the algorithms for the generation of the various grain sets are presented and discussed. Numerical results that compare the capabilities of the model that uses the deterministic scattering approach and those that adopt a random scattering, which is commonly used today, are presented and discussed. Emphasis is placed on the ability to predict the complex nonlinear material response and on the computational efficiency. The article closes with a summary and conclusions.
A New Piezoelectric Actuator using a Feed-screw for Quasi-static Motion Accumulation — Part I: Experimental Development
Authors: Loverich J.J. , Koopmann G.H. , Lesieutre G.A. , Frank J.E. , Chen W.
Published: March 2007

Piezoelectric materials' excellent dynamic performance, high energy density, and incremental positioning capability have motivated their use for solid-state actuation. However, harnessing a piezoelectric material's low-displacement and high-force electric field-induced mechanical output to perform large-displacement actuation is a significant challenge. Despite recent advances toward addressing this challenge, issues including long term reliability, high fabrication cost, and large power electronics remain obstacles for widespread application of piezoelectric actuators. This study proposes a new piezoelectric actuator design that achieves high performance actuation while making strides toward addressing the drawbacks of existing piezoelectric actuators. The new actuator's operation involves intermittent rotation of two nuts on a feed-screw to achieve quasi-static piezoelectric motion accumulation. Merits of the feed-screw concept include its reversible, robust, and high force actuation; simple power electronics; insensitivity to wear; and a rigid power-off self-locking state. The significance of this design is experimentally demonstrated by the fabrication of three prototype actuators, the best of which exhibited a 1235lb blocked force, 29 W peak power output, and 6.1 W/kg specific power.
Boundary Objects as Rhetorical Exigence: Knowledge Mapping and Interdisciplinary Cooperation at the Los Alamos National Laboratory
Authors: Wilson Greg , Herndl Carl G.
Published: March 2007

This article uses qualitative material gathered at the Los Alamos National Laboratory (LANL) to construct a model of the rhetorical activity that occurs at the boundaries between diverse communities of practice working on complex sociotechnical systems. The authors reinterpret the notion of the boundary object current in science studies as a rhetorical construct that can foster cooperation and communication among the diverse members of heterogeneous working groups. The knowledge maps constructed by team members at LANL in their work on technical systems are boundary objects that can replace the demarcation exigence that so often leads to agonistic rhetorical boundary work with an integrative exigence. The integrative exigence realized by the boundary object of the knowledge map can help create a temporary trading zone characterized by rhetorical relations of symmetry and mutual understanding. In such cases, boundary work can become an effort involving integration and understanding rather than contest, controversy, and demarcation.
Imaging the Organization: Language Use in Organizational Identity Claims
Authors: Ran Bing , Duimering P. Robert
Published: March 2007

This article investigates the cognitive linguistic processes involved in organizational identity construction through language-based identity claims. The organizational imaging process constructs an organization’s identity in relation to a system of positively and negatively valued conceptual categories. It involves using language to establish a classification scheme and to define the organization within this scheme. The authors develop a framework for identifying these cognitive linguistic processes based on a grounded-theory study of language use in corporate mission statements. Their findings contribute to a deeper understanding of language’s role in organizational identity construction.
Commentary: Reflections on Field Research and Professional Practice
Authors: Herndl Carl G. , Wilson Greg
Published: March 2007

Borrowing from the ethnographic genre that Van Maanen (1988) called the confessional tale, this commentary reflects on the political, ethical, and professional concerns that arise when critical intellectuals work in a government installation that maintains the nation’s nuclear stockpile. The authors suggest that the future is, as Haraway (1997) argued, ineluctably technological and that the best way to engage this cultural formation is from within, eschewing the easy politics of the science wars and articulating critical projects with the hard work of science. The modernist ideal of unconflicted ideological positions and research—stories of good guys and bad guys—is a disabling illusion. Practicing rhetoricians face a kind of “worldliness” that Hall (1989) described as a necessary counterpart to the “clean air” of theory. The authors invite their colleagues to join them in grappling with political and ethical analyses in a world of impure identity in which knowledge and power circulate promiscuously.
Risking It: Young Heterosexual Femininities in South African Context of HIV/AIDS
Authors: Reddy Shakila , Dunne Máiréad
Published: March 2007

This article explores gender power relations and the contradictions and confusions associated with sexual identity and normative (hetero-)sexual practices. Theories of ‘identity’ and ‘performativity’ are used to understand the relationships between young women's sexual identity constructions and sexual practices within the context of HIV/AIDS in South Africa. The discussion focuses on young women's accounts of their feminine identities with respect to issues of intimacy and romantic love; pregnancy, virginity and respect; desire, danger and disease; future marriage and family. It highlights the fragility and ambiguity in the processes of identity construction and performance of heterosexual femininity in an HIV/AIDS environment. Significantly, the dominant discourses of femininity through which these young women made sense of their sexual selves, stood in direct contradiction to their sexual safety. Given this, greater understanding of these identity processes would appear vital to successful strategies in the protection against HIV/AIDS in South Africa.
Behind the Bars of Masculinity: Male Rape and Homophobia in and about South African Men's Prisons
Authors: Gear Sasha
Published: March 2007

This article explores the dynamics and layers of discourse surrounding sex, sexual violence and coercion in South Africa's men's prisons. Violence in prison - most of which goes unrecorded - is ritualized and is fundamental in establishing inmate identities and hierarchies. Male rape, perhaps the most severely under-reported, is one of many forms of assault occurring (predominantly) between prisoners. Drawing on interviews with (ex-)prisoners, together with related media coverage, I show how in dominant discourses on prison sex and sexual violence a blurring occurs between ‘homosexuality’ and ‘male rape’. Consequently, inclusive understandings of diverse sexualities are negated and sexual violence in prison is denied. I trace how powerful discourses on gender and sexuality make invisible the violence of male rape, and simultaneously demonize same-sex desire behind bars. Moreover, I consider the embryonic discourses that challenge hegemonic understandings, arguing that they have not yet adequately succeeded in producing more accepting understandings of male sexuality or male victimization.
Too Weak for the Job
Authors: Wells Don
Published: March 2007

The shift of economic production from higher labour standard regimes in the global North to lower standard regimes in the South is undermining enforcement of global labour standards. Responding to criticisms from the ‘anti-sweatshop’ movement, consumers and governments, many transnational corporations (TNCs) have adopted codes of conduct to regulate labour standards in their supplier factories. Non-governmental organizations (NGOs) are increasingly used to monitor compliance with these codes. This article analyses the monitoring effectiveness of three kinds of such ‘third party’ NGOs. It concludes that major monitoring deficiencies reflect, first, significant organizational weaknesses of the NGOs and their dependence on TNCs for whom they monitor; second, powerful limits imposed on NGO effectiveness by corporate restructuring and market competitiveness; and third, inadequate pressures from anti-sweatshop movements, consumers and governments. These constraints suggest that this NGO-centred, ‘soft law’ policy approach is ‘too weak for the job’.
Analysis of Rail Transit Project Selection Bias With an Incentive Approach
Authors: Chen Wenling
Published: March 2007

Rail transit investments have been widely supported by the local planning agencies and government financing resources for their perceived environmental and social benefits, as well as the compact development patterns rail corridors support. Despite the widespread expectations, the sustainability of rail transit projects is often found questionable, as are the actual benefits rail investments can bring about in practice. One of the reasons for rail investments' tendency to perform less well than expected has been identified as a prevailing bias of local officials toward high-capital rail transit investments that are underwritten by the transit financing mechanism (Johnston et al., 1988; Kain, 1990; Pickrell, 1992; Richmond, 1999; Flyvbjerg et al., 2003, 2004, 2005). This article examines the funding mechanism problem underlying the rail transit project selection bias and hypothesizes this problem to be a principal–agent problem. Incentive theory is introduced as an analytical tool to model the problem, to better understand the nature and causes of the problem, and to suggest solutions to it. By applying incentive theory to analyze the project development process of the US New Starts program, it is suggested that the funding mechanism problem associated with the bias toward capital-intensive rail investments can be viewed as a principal–agent problem between the Federal Transit Administration (FTA) (the principal) and local project sponsors (the agent). The incentive approach proposed in this article provides insights for analyzing the relation between central government and local agencies in the planning and decision-making process of rail transit investment, and for addressing political problems, primarily rent-seeking behaviors, associated with central government earmark funding.
Sentencing in the Children’s Court: An Ethnographic Perspective
Authors: Travers Max
Published: March 2007

This paper presents findings from an ethnographic study, based on observing hearings and interviewing practitioners in the Youth Justice Division of the Magistrates’ Court in Hobart, Tasmania. Although there is a large academic literature by jurists on the philosophical principles, and social scientists on the attitudinal and institutional factors shaping court decisions, there have been few studies that examine what actually happens in the courtroom. This paper argues that much can be learnt about the collaborative nature of judicial work, the administrative side of decision-making (neglected by most studies) and the welfare values informing work in this court, through examining sentencing hearings.
Daring to Dream: Towards an Understanding of Young Black People’s Reflections Post-custody
Authors: Hill Jane
Published: March 2007

This article presents the findings of a post-custody study undertaken on behalf of the Children’s Society (a major NGO in England) which was part of the larger Just Justice programme that charted the experiences of young black people in the youth justice system in England and Wales (Wilson and Rees, 2006). It attempts to link the participants’ law-breaking behaviour to the structures of inequality within which they live their lives. Whilst the findings evidence the inappropriateness of penal custody for these young people, the data also offer the prospect of more positive outcomes in the future
The macrophage CD163 surface glycoprotein is an erythroblast adhesion receptor
Authors: Fabriek Babs O. , Polfliet Machteld M. J. , Vloet Rianka P. M. , van der Schors Roel C. , Ligtenberg Antoon J. M. , Weaver Lehn K. , Geest Christiaan , Matsuno Kenjiro , Moestrup Søren K. , Dijkstra Christien D. , van den Berg Timo K.
Published: March 2007

Erythropoiesis occurs in erythroblastic islands, where developing erythroblasts closely interact with macrophages. The adhesion molecules that govern macrophage-erythroblast contact have only been partially defined. Our previous work has implicated the rat ED2 antigen, which is highly expressed on the surface of macrophages in erythroblastic islands, in erythroblast binding. In particular, the monoclonal antibody ED2 was found to inhibit erythroblast binding to bone marrow macrophages. Here, we identify the ED2 antigen as the rat CD163 surface glycoprotein, a member of the group B scavenger receptor cysteine-rich (SRCR) family that has previously been shown to function as a receptor for hemoglobin-haptoglobin (Hb-Hp) complexes and is believed to contribute to the clearance of free hemoglobin. CD163 transfectants and recombinant protein containing the extracellular domain of CD163 supported the adhesion of erythroblastic cells. Furthermore, we identified a 13–amino acid motif (CD163p2) corresponding to a putative interaction site within the second scavenger receptor domain of CD163 that could mediate erythroblast binding. Finally, CD163p2 promoted erythroid expansion in vitro, suggesting that it enhanced erythroid proliferation and/or survival, but did not affect differentiation. These findings identify CD163 on macrophages as an adhesion receptor for erythroblasts in erythroblastic islands, and suggest a regulatory role for CD163 during erythropoiesis.
Human tissue mast cells are an inducible reservoir of persistent HIV infection
Authors: Sundstrom J. Bruce , Ellis Jane E. , Hair Gregory A. , Kirshenbaum Arnold S. , Metcalfe Dean D. , Yi Hong , Cardona Adriana C. , Lindsay Michael K. , Ansari Aftab A.
Published: March 2007

We have proposed that, unlike other HIV-vulnerable cell lineages, progenitor mast cells (prMCs), cultured in vitro from undifferentiated bone marrow–derived CD34+ pluripotent progenitors (PPPs), are susceptible to infection during a limited period of their ontogeny. As infected prMCs mature in culture, they lose expression of viral chemokine coreceptors necessary for viral entry and develop into long-lived, latently infected mature tissue mast cells (MCs), resistant to new infection. In vivo recruitment of prMCs to different tissue compartments occurs in response to tissue injury, growth, and remodeling or allergic inflammation, allowing populations of circulating and potentially HIV-susceptible prMCs to spread persistent infection to diverse tissue compartments. In this report, we provide in vivo evidence to confirm this model by demonstrating that HIV-infected women have both circulating prMCs and placental tissue MCs (PLMCs) that harbor inducible infectious HIV even after highly active antiretroviral therapy (HAART) during pregnancy. Furthermore, infectious virus, capable of infecting alloactivated fetal cord blood mononuclear cells (CBMCs), could be induced in isolated latently infected PLMCs after weeks in culture in vitro. These data provide the first in vivo evidence that tissue MCs, developed from infected circulating prMCs, comprise a long-lived inducible reservoir of persistent HIV in infected persons during HAART.
Abnormal microRNA-16 locus with synteny to human 13q14 linked to CLL in NZB mice
Authors: Raveche Elizabeth S. , Salerno Erica , Scaglione Brian J. , Manohar Vijaya , Abbasi Fatima , Lin Yi-Chu , Fredrickson Torgny , Landgraf Pablo , Ramachandra Sumant , Huppi Konrad , Toro Jorge R. , Zenger Vincent E. , Metcalf Robert A. , Marti Gerald E.
Published: March 2007

New Zealand black (NZB) mice with autoimmune and B lymphoproliferative disease (B-LPD) are a model for human chronic lymphocytic leukemia (CLL). A genomewide linkage scan of the NZB loci associated with lymphoma was conducted in F1 backcrosses of NZB and a control strain, DBA/2. Of 202 mice phenotyped for the presence or absence of LPD, surface maker expression, DNA content, and microsatellite polymorphisms, 74 had disease. The CD5+, IgM+, B220dim, hyperdiploid LPD was linked to 3 loci on chromosomes 14, 18, and 19 that are distinct from previously identified autoimmunity-associated loci. The region of synteny with mouse D14mit160 is the human 13q14 region, associated with human CLL, containing microRNAs mir-15a16-1. DNA sequencing of multiple NZB tissues identified a point mutation in the 3′ flanking sequence of the identical microRNA, mir-16-1, and this mutation was not present in other strains, including the nearest neighbor, NZW. Levels of miR-16 were decreased in NZB lymphoid tissue. Exogenous miR-16 delivered to an NZB malignant B-1 cell line resulted in cell-cycle alterations and increased apoptosis. Linkage of the mir-15a/16-1 complex and the development of B-LPD in this spontaneous mouse model suggest that the altered expression of the mir-15a/16-1 is the molecular lesion in CLL.
Resolution of LPS-induced airway inflammation and goblet cell hyperplasia is independent of IL-18
Authors: Harris J Foster , Aden Jay , Lyons C Rick , Tesfaigzi Yohannes
Published: March 2007

Background

The resolution of inflammatory responses in the lung has not been described in detail and the role of specific cytokines influencing the resolution process is largely unknown.

Methods

The present study was designed to describe the resolution of inflammation from 3 h through 90 d following an acute injury by a single intratracheal instillation of F344/N rats with LPS. We documented the inflammatory cell types and cytokines found in the bronchoalveolar lavage fluid (BALF), and epithelial changes in the axial airway and investigated whether IL-18 may play a role in the resolution process by reducing its levels with anti-IL-18 antibodies.

Results

Three major stages of inflammation and resolution were observed in the BALF during the resolution. The first stage was characterized by PMNs that increased over 3 h to 1 d and decreased to background levels by d 6–8. The second stage of inflammation was characterized by macrophage influx reaching maximum numbers at d 6 and decreasing to background levels by d 40. A third stage of inflammation was observed for lymphocytes which were elevated over d 3–6. Interestingly, IL-18 and IL-9 levels in the BALF showed a cyclic pattern with peak levels at d 4, 8, and 16 while decreasing to background levels at d 1–2, 6, and 12. Depletion of IL-18 caused decreased PMN numbers at d 2, but no changes in inflammatory cell number or type at later time points.

Conclusion

These data suggest that IL-18 plays a role in enhancing the LPS-induced neutrophilic inflammation of the lung, but does not affect the resolution of inflammation.
Biomechanical effects of polyaxial pedicle screw fixation on the lumbosacral segments with an anterior interbody cage support
Authors: Chen Shih-Hao , Mo Lin Ruey , Chen Hsiang-Ho , Tsai Kai-Jow
Published: March 2007

Background

Lumbosacral fusion is a relatively common procedure that is used in the management of an unstable spine. The anterior interbody cage has been involved to enhance the stability of a pedicle screw construct used at the lumbosacral junction. Biomechanical differences between polyaxial and monoaxial pedicle screws linked with various rod contours were investigated to analyze the respective effects on overall construct stiffness, cage strain, rod strain, and contact ratios at the vertebra-cage junction.

Methods

A synthetic model composed of two ultrahigh molecular weight polyethylene blocks was used with four titanium pedicle screws (two in each block) and two rods fixation to build the spinal construct along with an anterior interbody cage support. For each pair of the construct fixed with polyaxial or monoaxial screws, the linked rods were set at four configurations to simulate 0°, 7°, 14°, and 21° lordosis on the sagittal plane, and a compressive load of 300 N was applied. Strain gauges were attached to the posterior surface of the cage and to the central area of the left connecting rod. Also, the contact area between the block and the cage was measured using prescale Fuji super low pressure film for compression, flexion, lateral bending and torsion tests.

Results

Our main findings in the experiments with an anterior interbody cage support are as follows: 1) large segmental lordosis can decrease the stiffness of monoaxial pedicle screws constructs; 2) polyaxial screws rather than monoaxial screws combined with the cage fixation provide higher compression and flexion stiffness in 21° segmental lordosis; 3) polyaxial screws enhance the contact surface of the cage in 21° segmental lordosis.

Conclusion

Polyaxial screws system used in conjunction with anterior cage support yields higher contact ratio, compression and flexion stiffness of spinal constructs than monoaxial screws system does in the same model when the spinal segment is set at large lordotic angles. Polyaxial pedicle screw fixation performs nearly equal percentages of vertebra-cage contact among all constructs with different sagittal alignments, therefore enhances the stabilization effect of interbody cages in the lumbosacral area.
Transcriptional activation of the human papillomavirus type 5 and 16 long control region in cells from cutaneous and mucosal origin
Authors: Mistry Nitesh , Simonsson Monika , Evander Magnus
Published: March 2007

Human papillomavirus type-16 (HPV-16) infects mucosal epithelium and is the most common type found in cervical cancer. HPV-5 infects cornified epithelium and is the most common type found on normal skin and belongs to the types frequently associated with skin cancers ofEpidermodysplasia verruciformispatients. One factor by which this anatomical tropism could be determined is the regulation of HPV gene expression in the host cell. The HPV long control region (LCR) contains cis-responsive elements that regulate HPV transcription and the epithelial tropism of HPV is determined by epithelial specific constitutive enhancers in the LCR. Since HPV-16 and other types infecting the mucosa differ in host cell from HPV types infecting skin, it has been hypothesized that it is the combination of ubiquitous transcription factors working in concert in the host cell that determines the cell-type-specific expression. To study if HPV tropism could be determined by differences in transcriptional regulation we have cloned the transcriptional regulating region, LCR, from HPV-16 and HPV-5 and studied the activation of a reporter gene in cell lines with different origin. To analyse promoter activity we transfected the plasmids into four different cell lines; HaCaT, C33A, NIKS and W12E and the efficiency of HPV-5 and HPV-16 LCR in the different cell lines was compared. In HaCaT cells, with a skin origin, the HPV-5 LCR was two-fold more efficient in transcriptional activation compared to the HPV-16 LCR. In cervical W12E cells the HPV-16 LCR was almost 2-fold more effective in activating transcription compared to the HPV-5 LCR. The ability to initiate transcription in the other cell lines was independent on cell origin and HPV-type.
Developmental stage related patterns of codon usage and genomic GC content: searching for evolutionary fingerprints with models of stem cell differentiation
Authors: Ren Lichen , Gao Ge , Zhao Dongxin , Ding Mingxiao , Luo Jingchu , Deng Hongkui
Published: March 2007

Background

The usage of synonymous codons shows considerable variation among mammalian genes. How and why this usage is non-random are fundamental biological questions and remain controversial. It is also important to explore whether mammalian genes that are selectively expressed at different developmental stages bear different molecular features.

Results

In two models of mouse stem cell differentiation, we established correlations between codon usage and the patterns of gene expression. We found that the optimal codons exhibited variation (AT- or GC-ending codons) in different cell types within the developmental hierarchy. We also found that genes that were enriched (developmental-pivotal genes) or specifically expressed (developmental-specific genes) at different developmental stages had different patterns of codon usage and local genomic GC (GCg) content. Moreover, at the same developmental stage, developmental-specific genes generally used more GC-ending codons and had higher GCg content compared with developmental-pivotal genes. Further analyses suggest that the model of translational selection might be consistent with the developmental stage-related patterns of codon usage, especially for the AT-ending optimal codons. In addition, our data show that after human-mouse divergence, the influence of selective constraints is still detectable.

Conclusion

Our findings suggest that developmental stage-related patterns of gene expression are correlated with codon usage (GC3) and GCg content in stem cell hierarchies. Moreover, this paper provides evidence for the influence of natural selection at synonymous sites in the mouse genome and novel clues for linking the molecular features of genes to their patterns of expression during mammalian ontogenesis.
Self-Reported Cognitive Impairment in Patients With Cancer
Authors: Kohli Sadhna , Griggs Jennifer J. , Roscoe Joseph A. , Jean-Pierre Pascal , Bole Christopher , Mustian Karen M. , Hill Renae , Smith Kelly , Gross Howard , Morrow Gary R.
Published: March 2007

Purpose

Cancer patients often report cognitive impairment, manifested as problems with concentration and memory, following cancer therapy. As part of a large multicenter survey of cancer patients undergoing treatment, we investigated the frequency and severity of self-reported problems with memory and concentration over time.

Methods

A total of 595 patients undergoing treatment for solid tumors self-rated problems with memory and concentration, using an 11-point Likert scale (0 = “not present” to 10 = “as bad as you can imagine”) at baseline before treatment began (T1), at their worst during treatment (T2), and at 6 months following treatment (T3). Any symptom level ≥ 7 was classified as “severe.” Paired or independent t tests (as appropriate) with a Bonferroni correction were used to examine differences in symptoms over time and between patients treated with chemotherapy, radiation therapy, or both.

Results

Concentration problems were reported by 48% of the 595 participants at T1 (5% severe), 67% at T2 (18% severe), and 58% (8% severe) at T3. Problems with memory were reported by 53% at T1 (4% severe), 67% (18% severe) at T2, and 68% (11% severe) at T3. The average frequency and severity of both symptoms in patients receiving chemotherapy, with or without radiation, increased significantly between T1 and T2 (P < .001). Both symptoms were less severe in patients receiving radiation alone at all three measurements than in either of the chemotherapy groups (all P values < .001). Symptoms at T3 were significantly higher than T1 for all groups (P < .001).

Conclusion

A significant proportion of patients undergoing cancer therapy self-report problems with memory and concentration. Cognitive problems get worse during treatment and are still in evidence 6 months following the conclusion of treatments.
The clinical significance of immunoglobulin A deficiency
Authors: Latiff Amir H Abdul , Kerr Michael A
Published: March 2007

IgA deficiency is the most common primary immunoglobulin deficiency. The prevalence in Caucasians is around one in 500, whereas in some Asian populations it is very uncommon. Most individuals with IgA deficiency are clinically asymptomatic. Those with symptoms of immunodeficiency have predominantly sinopulmonary or gastrointestinal infections, which are more severe when associated with IgG2, IgG4 or specific antibody deficiency. IgA deficiency is believed to be one end of a spectrum of immunodeficiency with common variable immunodeficiency at the most severe end. Although primary IgA deficiency is the most commonly encountered form, secondary deficiencies due to drugs or viral infections are recognized. IgA deficiencies can be partial or transient

Primary IgA deficiency is caused by a defect of terminal lymphocyte differentiation, which leads to underproduction of serum and mucosal IgA; affected individuals have normal IgA genes. A number of non-immunoglobulin genes have been implicated in IgA deficiency. There have been many diseases reported in association with IgA deficiency, particularly autoimmune diseases. The most common association is with coeliac disease (CD), which has special significance since CD is usually diagnosed by detection of specific IgA antibodies that are obviously lacking in IgA deficiency. There is no specific treatment for patients with symptomatic IgA deficiency. Antibiotics are prescribed in those with acute infections. A significant proportion of IgA-deficient individuals are reported to have anti-IgA antibodies in their serum. Although blood or blood products given to IgA-deficient individuals can lead to severe, even fatal, transfusion reactions, such reactions are rare.
Haemolysis in neonatal blood samples: a survey of practice
Authors: Joshi S , Vaitkute R , Jeffery J , Ayling R M
Published: March 2007

Objective: To survey how laboratories report, and neonatologists perceive them to report, the presence of haemolysis in neonatal blood samples.

Methods: A questionnaire was sent to clinical biochemists and neonatologists in 88 hospitals believed to be using Roche methodology.

Results: A 49% response rate was obtained. Seventeen hospitals were excluded from analysis owing to incomplete questionnaires or altered methodology. Of the remaining 71 hospitals, 30 (42%) laboratories and 18 (25%) neonatologists responded - where both responded, none gave identical replies. Eighteen laboratories admitted the use of serum indices to make decisions on haemolysed samples. Although recommended interference limits are available from Roche, there was little consensus between laboratories.

Conclusions: Laboratories should have clear guidelines on the processing of haemolysed samples from neonates and these should be adequately communicated to those responsible for their direct care.
Dinitrophenyl derivatization of imino acids, spectral characteristics and HPLC analysis: application in urinary peptide-derived hydroxyproline and proline assay
Authors: Badadani Mallikarjun , Suresh Babu S V , Shetty K Taranath
Published: March 2007

Background: Assay of urinary imino acids, in particular peptide derived, is of immense utility in diagnosis of collagen-related disorders. The often-used methods for hydrolysis of urinary peptides need a long time and are cumbersome, hence the need for relatively simpler, but effective methods.

Methods: The method described, based on alkaline hydrolysis by autoclaving for 60 min followed by pre-column dinitrophenyl (DNP) derivatization and high-performance liquid chromatography (HPLC) analysis, demonstrates the complete hydrolysis and stability of urinary peptide derived imino acids.

Results: DNP derivatives of both imino acids had identical λ max (380 nm) with molar ε of 28.224 x 103 and 17.036 x 103, respectively, for hydroxyproline (Hyp) and proline (Pro). HPLC run, extending up to 18 min, resolved major components of collagen products, namely Hyp, Hyl, Gly, Pro and Lys, with retention times of 6.5, 9.8, 10.5, 11.2 and 12.55 min, respectively. The assay method conformed to linear response for individual amino acid concentrations of 0.5-4.0 nmol per injection, with goodness of fit ( r2 value) 0.99 for both Hyp and Pro, and detection limit of 0.05-4.0 nmol of DNP derivatives. The recovery of Pro and Hyp, when spiked with urine prior to hydrolysis, were found to be 95% and 92%, respectively.

Conclusion: Alkaline hydrolysis by autoclaving and DNP derivatization of imino acids followed by HPLC provides a method for the analysis of peptide-derived Hyp and Pro in urine. Hence, it is of utility to study collagen disorders.
Axial Loading Behavior of CFRP Strengthened Concrete-Filled Steel Tubular Stub Columns
Authors: Tao Zhong , Han Lin-Hai , Zhuang Jin-Ping
Published: March 2007

This paper presents the axial compression test results of concrete-filled steel tubular (CFST) stub columns strengthened with carbon fiber reinforced polymer (CFRP) composites. Both circular and rectangular specimens were tested to investigate the retrofitting effects of CFRP composites on them. The test results showed that the CFRP jackets enhanced the load bearing capacity of the circular columns effectively, whereas the enhancement was not so significant for rectangular columns. However, ductility was enhanced to some extent for those rectangular columns. A simple model is proposed to calculate the ultimate strength of circular CFST stub columns wrapped with CFRP. The predicted results are generally in good agreement with the experimental ones obtained in this study and in the literature.
Investigations on the Performance of Concrete Made with Blended Finely Milled Waste Glass
Authors: Metwally Ibrahim M.
Published: March 2007

Non-recyclable waste glass, which is produced from fluorescent lamps factories, constitutes a problem for solid waste disposal in various countries worldwide. Thereby, the accumulation of waste glass in the plants, not being used, represents not only a significant loss of money and energy by occupying a big area from plants but also a negative impact on the environment. This study is considered of significant interest in the development of environmentally friendly concrete containing waste glass.

Using waste glass as a construction material is a good way to help the environment following grinding and its use in concrete as a partial replacement for cement by weight. Five different concrete mixes with various percentages of finely milled waste glass (FMWG) were prepared. The test results showed that the FMWG has pozzolanic characteristics and using it as a mineral admixture in concrete, had a bad effect on workability, but improved considerably the mechanical properties of concrete at later ages. The optimum percentage of FMWG that gives the maximum values of compressive, splitting tensile and bond strengths is 10%. Results also showed that expansion due to alkali-silica reaction was minimized obviously by increase in the FMWG content.
Effects of Ordinary Tension Reinforcement on the Response of Beams with Unbonded Tendons
Authors: Lou T.J. , Xiang Y.Q.
Published: March 2007

This paper describes an analytical investigation of the flexural response of unbonded prestressed beams and the ultimate stress increase in unbonded tendons, with particular emphasis on the effects of bonded ordinary tension reinforcement. A numerical model, based on the finite element method incorporating an arc-length solution technique, is developed to predict the entire nonlinear response of concrete beams prestressed with unbonded tendons. The reliability of the proposed analysis is verified by comparing the analytical predictions with the experimental results. Two parameters relating to bonded ordinary tension reinforcement are analytically investigated. The analytical results show that an unbonded prestressed concrete beam without any ordinary tension reinforcement exhibits very poor behaviour. However, with the minimum amount of ordinary tension reinforcement provided, the flexural behaviour of the beam is greatly improved. The variable yield strength of ordinary reinforcement in combined reinforcing index is inappropriate in its current form since the calculated prediction is inconsistent with the actual trend of the variation of ultimate stress increase in tendons.
Measurement and Analysis of Wind-Induced Response of Tall Building Based on GPS Technology
Authors: Li Hong-Nan , Yi Ting-Hua , Yi Xiao-Dong , Wang Guo-Xin
Published: March 2007

The Global Positioning System (GPS) has been used in the health monitoring of large structures in recent years since it is weather independent, capable of autonomous operation, and does not require a line-of-sight between target points. In this paper, a structural health monitoring system based on the GPS is devised for a high-rise building. The field data, such as wind speed, wind direction and displacement responses were simultaneously and continuously measured under strong wind conditions. The relation between velocity components of the atmospheric wind and pressure fluctuations on the roof of the building are analyzed using the wavelet scalogram and wavelet coherence method, and a statistical significance level estimation method based on Monte Carlo simulation is presented to isolate the meaningful coherence from the spurious noise map. Finally, the responses of the high-rise building are investigated using the Periodogram method to conclude that the identified results agree well with the results computed by the Finite Element Method (FEM).
Probabilistic Response Analysis of Cracked Prestressed Concrete Beams
Authors: Cheng Jin , Cai C. S. , Xiao Ru-Cheng
Published: March 2007

In the response analysis of cracked prestressed concrete beams deterministic procedure is insufficient to provide complete information. Probabilistic analysis is a holistic approach to predicting structural responses considering uncertainties in structural and load parameters. This paper proposes an efficient and accurate algorithm to predict responses of cracked prestressed concrete beams with parameter uncertainties. The proposed algorithm integrates the advantages of the response surface method, section curvature method and Monte Carlo simulation. Uncertainties in the structure and load parameters can be taken into account in this algorithm. The algorithm is verified using the Monte Carlo simulation. The proposed algorithm is then used to predict the response of a simply supported prestressed beam with parameter uncertainties. The results show that neglecting the effect of uncertainty in the prestressing force results in a significant underestimation of response statistics of cracked prestressed concrete beams. Finally, the most influential random variables on the response statistics of cracked prestressed concrete beams are identified by using a sensitivity analysis.
Direct Computation of an Annular Liquid Jet
Authors: Jiang Xi , Siamas George A.
Published: March 2007

An Eulerian approach with mixed-fluid treatment has been used to study the flow field of an annular liquid jet in a compressible gas medium. A mathematical formulation is developed which is capable of representing the two-phase flow system with the gas phase treated as compressible and liquid as incompressible, where the volume of fluid method has been adapted to take into account the gas compressibility. The mathematical formulation is then applied to the computational analysis of an annular liquid jet, in order to achieve a better understanding on the flow physics by providing detailed information on the flow field. The gas-liquid two-phase flow system has been examined by direct solution of the governing equations using highly accurate numerical schemes. The numerical simulation shows that the dispersion of the annular liquid jet is characterised by a recirculation zone adjacent to the nozzle exit. Without applying perturbation at the domain inlet, vortical structures develop at the downstream locations of the flow field due to the Kelvin-Helmholtz instability. The flow becomes more energetic at progressive downstream locations with the dominating frequencies becoming smaller.
Finite Difference Approximation for Two-Dimensional Time Fractional Diffusion Equation
Authors: Zhuang P. , Liu F.
Published: March 2007

Fractional diffusion equations have recently been used to model problems in physics, hydrology, biology and other areas of application. In this paper, we consider a two-dimensional time fractional diffusion equation (2D-TFDE) on a finite domain. An implicit difference approximation for the 2D-TFDE is presented. Stability and convergence of the method are discussed using mathematical induction. Finally, a numerical example is given. The numerical result is in excellent agreement with our theoretical analysis.
Digitizing the Sedimentary Record: Efficient Data Structures for Dynamic Stratigraphy
Authors: Wolinsky Matthew A.
Published: March 2007

As the surface of the Earth evolves over geologic time sediment is transported from high mountains to low lying sedimentary basins, accumulating stratigraphy which stores a sedimentary record of past environments. Understanding the structure of this stratigraphy is essential for exploiting sub-surface resources such as oil and water, and for deciphering the sedimentary record. Sophisticated computational models of Earth-surface dynamics can be used to predict formation of stratigraphy, but require stratigraphy in a discrete form. Here I present a discrete stratigraphic data structure which enables simulation of dynamic stratigraphic evolution. The data structure is robust and efficient, but can be easily coupled to existing Earth-surface dynamics models with minimal effort due to a simple interface. This represents a significant advance which will allow widespread use of dynamic models to predict and invert stratigraphy for application in a variety of fields.
Subtrochanteric insufficiency fractures in patients on alendronate therapy
Authors: Goh S.-K. , Yang K. Y. , Koh J. S. B. , Wong M. K. , Chua S. Y. , Chua D. T. C. , Howe T. S.
Published: March 2007

We carried out a retrospective review over ten months of patients who had presented with a low-energy subtrochanteric fracture. We identified 13 women of whom nine were on long-term alendronate therapy and four were not. The patients treated with alendronate were younger, with a mean age of 66.9 years (55 to 82) vs 80.3 years (64 to 92) and were more socially active. The fractures sustained by the patients in the alendronate group were mainly at the femoral metaphyseal-diaphyseal junction and many had occurred after minimal trauma. Five of these patients had prodromal pain in the affected hip in the months preceding the fall, and three demonstrated a stress reaction in the cortex in the contralateral femur.

Our study suggests that prolonged suppression of bone remodelling with alendronate may be associated with a new form of insufficiency fracture of the femur. We believe that this finding is important and indicates the need for caution in the long-term use of alendronate in the treatment of osteoporosis.
Feelings and the need for information and counselling of expectant parents of twins
Authors: Nys Kristien , Colpin Hilde , Munter Agnes De , Vandemeulebroecke Lieve
Published: March 2007

In this study, expectant parents of twins were questioned about their feelings and need for information and counselling on the parenting of twins. Data were obtained from self-rating questionnaires and an interview with the expectant mother. From the results it is argued that expectant parents of twins need specific information and counselling about the medical, emotional and parenting issues of having twins. Guidelines for organising this counselling are proposed.
Genetic risk factors in tumours of the testis: lessons from twin studies
Authors: Lambalk Cornelis B , Boomsma Dorret I
Published: March 2007

A threefold increase for testicular carcinoma has been reported in male dizygotic twins. In this comment we suggest the hypothesis that over-exposure to endogenously hypersecreted Follicle Stimulating Hormone (FSH) may underlie the pathogenesis. This is supported by several findings. 1) FSH hypersecretion in mothers of dizygotic twins is most likely an autosomal trait implicating the possibility of male offspring with the same hormone characteristic. 2) In testicular carcinoma higher levels of cyclin D2 are found. This is an FSH dependent stimulatory regulator of mitosis. 3) There is a marked similarity between geographical distribution in occurence of dizygotic twinning and testicular carcinoma. 4) Men undergoing surgery for testicular carcinoma have higher FSH concentrations and males with Down syndrome have higher FSH levels and are more at risk to develop testicular carcinoma. We suggest to study FSH secretion in males of familial dizygotic twins and furthermore the risk of developing testicular carcinoma in males with elevated FSH. These men with one testicle and/or with dysfunctioning Sertoli/Leydig cells.