bluuebunny/crossref_metadata_2025_split huggingface dataset:
Discordant Outcomes following Failure of Antiretroviral Therapy Are Associated with Substantial Differences in Human Immunodeficiency Virus-Specific Cellular Immunity
Authors: Price David A. , Scullard George , Oxenius Annette , Braganza Ruth , Beddows Simon A. , Kazmi Shamim , Clarke John R. , Johnson Gabriele E. , Weber Jonathan N. , Phillips Rodney E. 
Published: April 2003

ABSTRACT

Many individuals chronically infected with human immunodeficiency virus type 1 (HIV-1) experience a recrudescence of plasma virus during continuous combination antiretroviral therapy (ART) due either to the emergence of drug-resistant viruses or to poor compliance. In most cases, virologic failure on ART is associated with a coincident decline in CD4
+
T lymphocyte levels. However, a proportion of discordant individuals retain a stable or even increasing CD4
+
T lymphocyte count despite virological failure. In order to address the nature of these different outcomes, we evaluated virologic and immunologic variables in a prospective, single-blinded, nonrandomized cohort of 53 subjects with chronic HIV-1 infection who had been treated with continuous ART and monitored intensively over a period of 19 months. In all individuals with detectable viremia on ART, multiple drug resistance mutations with similar impacts on viral growth kinetics were detected in the
pol
gene of circulating plasma virus. Further, C2V3
env
gene analysis demonstrated sequences indicative of CCR5 coreceptor usage in the majority of those with detectable plasma viremia. In contrast to this homogeneous virologic pattern, comprehensive screening with a range of antigens derived from HIV-1 revealed substantial immunologic differences. Discordant subjects with stable CD4
+
T lymphocyte counts in the presence of recrudescent virus demonstrated potent virus-specific CD4
+
and CD8
+
T lymphocyte responses. In contrast, subjects with virologic failure associated with declining CD4
+
T lymphocyte counts had substantially weaker HIV-specific CD4
+
T lymphocyte responses and exhibited a trend towards weaker HIV-specific CD8
+
T lymphocyte responses. Importantly the CD4
+
response was sustained over periods as long as 11 months, confirming the stability of the phenomenon. These correlative data lead to the testable hypothesis that the consequences of viral recrudescence during continuous ART are modulated by the HIV-specific cellular immune response.
The NB Protein of Influenza B Virus Is Not Necessary for Virus Replication In Vitro
Authors: Hatta Masato , Kawaoka Yoshihiro 
Published: April 2003

ABSTRACT
The NB protein of influenza B virus is thought to function as an ion channel and therefore would be expected to have an essential function in viral replication. Because direct evidence for its absolute requirement in the viral life cycle is lacking, we generated NB knockout viruses by reverse genetics and tested their growth properties both in vitro and in vivo. Mutants not expressing NB replicated as efficiently as the wild-type virus in cell culture, whereas in mice they showed restricted growth compared with findings for the wild-type virus. Thus, the NB protein is not essential for influenza B virus replication in cell culture but promotes efficient growth in mice.
In Situ Characterization of
Cymbidium Ringspot Tombusvirus
Infection-Induced Posttranscriptional Gene Silencing in
Nicotiana benthamiana
Authors: Havelda Zoltán , Hornyik Csaba , Crescenzi Aniello , Burgyán József 
Published: April 2003

ABSTRACT

In plants, posttranscriptional gene silencing (PTGS) is an ancient and effective defense mechanism against viral infection. A number of viruses encode proteins that suppress virus-activated PTGS. The p19 protein of tombusviruses is a potent PTGS suppressor which interferes with the onset of PTGS-generated systemic signaling and is not required for viral replication or for viral movement in
Nicotiana benthamiana.
This unique feature of p19 suppressor allowed us to analyze the mechanism of PTGS-based host defense and its viral suppression without interfering with other viral functions. In contrast to the necrotic symptoms caused by wild-type tombusvirus, the infection of p19-defective mutant virus results in the development of a typical PTGS-associated recovery phenotype in
N. benthamiana
. In this report we show the effect of PTGS on the viral infection process for
N. benthamiana
infected with either wild-type
Cymbidium Ringspot Tombusvirus
(CymRSV) or a p19-defective mutant (Cym19stop). In situ analyses of different virus-derived products revealed that PTGS is not able to reduce accumulation of virus in primary infected cells regardless of the presence of p19 PTGS suppressor. We also showed that both CymRSV and Cym19stop viruses move systemically in the vasculature, with similar efficiencies. However, in contrast to the uniform accumulation of CymRSV throughout systemically infected leaves, the presence of Cym19stop virus was confined to and around the vascular bundles. These results suggest that the role of p19 is to prevent the onset of mobile signal-induced systemic PTGS ahead of the viral infection front, leading to generalized infection.
EFFICIENT RECONSTRUCTION OF HAPLOTYPE STRUCTURE VIA PERFECT PHYLOGENY
Authors: ESKIN ELEAZAR , HALPERIN ERAN , KARP RICHARD M. 
Published: April 2003

Each person's genome contains two copies of each chromosome, one inherited from the father and the other from the mother. A person's genotype specifies the pair of bases at each site, but does not specify which base occurs on which chromosome. The sequence of each chromosome separately is called a haplotype. The determination of the haplotypes within a population is essential for understanding genetic variation and the inheritance of complex diseases. The haplotype mapping project, a successor to the human genome project, seeks to determine the common haplotypes in the human population. Since experimental determination of a person's genotype is less expensive than determining its component haplotypes, algorithms are required for computing haplotypes from genotypes. Two observations aid in this process: first, the human genome contains short blocks within which only a few different haplotypes occur; second, as suggested by Gusfield, it is reasonable to assume that the haplotypes observed within a block have evolved according to a perfect phylogeny, in which at most one mutation event has occurred at any site, and no recombination occurred at the given region. We present a simple and efficient polynomial-time algorithm for inferring haplotypes from the genotypes of a set of individuals assuming a perfect phylogeny. Using a reduction to 2-SAT we extend this algorithm to handle constraints that apply when we have genotypes from both parents and child. We also present a hardness result for the problem of removing the minimum number of individuals from a population to ensure that the genotypes of the remaining individuals are consistent with a perfect phylogeny. Our algorithms have been tested on real data and give biologically meaningful results. Our webserver () is publicly available for predicting haplotypes from genotype data and partitioning genotype data into blocks.
Puppy Pregnancy in Humans: A Culture-Bound Disorder in Rural West Bengal, India
Authors: Chowdhury A. N. , Mukherjee Himadri , Ghosh Kumar Kanti , Chowdhury Shyamali 
Published: April 2003

Background: Delusion of pregnancy in males, though uncommon, has been reported in the literature. Delusion of animal pregnancy in humans is unreported until now, and we are reporting here cases of puppy pregnancy in human beings from a part of rural West Bengal, India. Material: Studies of six male cases and one female case of delusion of puppy pregnancy after an alleged touch or bite of a dog are presented. Discussion: Detailed phenomenological analysis revealed that there exists a strong cultural belief that dog bite may evolve into a puppy pregnancy even in the human male. Psychiatric status showed that there was a clear association of obsessive-compulsive disorder in two cases, anxiety-phobic locus in one and three showed no other mental symptom except this solitary false belief and preoccupation about the puppy pregnancy. All the cases were from rural areas and their communities endorse this pathogenic event of puppy pregnancy in humans. One case (11-year-old child) exemplified how the social imposition of this cultural belief made him a case that allegedly vomited out an embryo of a dog foetus. Conclusion: Although the belief in puppy pregnancy is culturally shared, the cases presented a mix of somatic and psychological complaints and their help-seeking behaviour was marked. These features prompted us to identify this phenomena as a culture-bound disorder which needs proper cultural understanding for its effective management.
Fatigue and Reliability Analysis of Unidirectional GFRP Composites under Rotating Bending Loads
Authors: Khashaba U. A. 
Published: April 2003

Rotating bending fatigue tests have been conducted on unidirectional glass fiber reinforced polyester (GFRP) composites. Standard test specimens were manufactured in form of circular rods with various fiber volume fraction ( Vf) ratios. Failure modes of the composite rods have been examined using scanning electron microscope. The two-parameter Weibull distribution function was used to investigate the statistical analysis of the experimental fatigue life results. Safe design life based on time to first failure (TTFF) concept was calculated at high confidence level γ=0.99 and at two values of reliability, R=0.368 and 0.99. S–N diagrams of mean life, 50% survival life, lower bound life and safe design fatigue life have been constructed for GFRP rods with various values of Vf ratios. These diagrams are of considerable value to the designer specially when the structure contains a critical component where any failure is catastrophic. No rigorous fatigue limit was observed within 107 cycles in these S–N diagrams. The fiber volume fractions have insignificant effect on the slope of the power function that fits the mean fatigue life. At the same number of cycles the stress amplitude required to fracture the specimens with Vf=44.7% was increased by an order equal to 1.58 and1.25 than specimens with Vf=15.8 and 31.8% respectively. The widest scatter was observed at the life range of 105 and 106 cycles for GFRP rode with different Vf ratios. This tendency in the dispersion of fatigue life at varying stress levels is extremely important and deserves much attention for the design and application of GFRP composites.
Complete Path Planning for Closed Kinematic Chains with Spherical Joints
Authors: Trinkle J.C. , Milgram R. James 
Published: April 2003

We study the path planning problem, without obstacles, for closed kinematic chains with n links connected by spherical joints in space or revolute joints in the plane. The configuration space of such systems is a real algebraic variety whose structure is fully determined using techniques from algebraic geometry and differential topology. This structure is then exploited to design a complete path planning algorithm that produces a sequence of compliant moves, each of which monotonically increases the number of links in their goal configurations. The average running time of this algorithm is proportional to n3 . While less efficient than the O (n ) algorithm of Lenhart and Whitesides, our algorithm produces paths that are considerably smoother. More importantly, our analysis serves as a demonstration of how to apply advanced mathematical techniques to path planning problems. Theoretically, our results can be extended to produce collision-free paths, paths avoiding both link—obstacle and link—link collisions. An approach to such an extension is sketched in Section 4.5, but the details are beyond the scope of this paper. Practically, link— obstacle collision avoidance will impact the complexity of our algorithm, forcing us to allow only small numbers of obstacles with “nice” geometry, such as spheres. Link—link collision avoidance appears to be considerably more complex. Despite these concerns, the global structural information obtained in this paper is fundamental to closed kinematic chains with spherical joints and can easily be incorporated into probabilistic planning algorithms that plan collision-free motions. This is also described in Section 4.5.
Dermatoglyphics and the Persistence of `Mongolism'
Authors: Miller Fiona Alice 
Published: April 2003

In 1961, a prestigious group of medical researchers called on their colleagues to stop using the language of `Mongolism' to describe people with what we now call `Down's syndrome' (or Trisomy 21). This call responded to new knowledge about the biological basis of Down's syndrome: rather than the product of racial degeneration, as had been hypothesized in the 19th century, the condition was the result of an extra chromosome, dubbed `21'. Yet, despite this plea, the terms `Mongol' and `Mongolism' continued in scientific use through the 1960s. Drawing on published and archival materials, I argue that the new knowledge about chromosomes did not rupture older patterns of scientific practice or interpretation, and with them, older terminological habits. The persistence of the language of Mongolism reflects the continuity of a network of older approaches to interpreting the condition within the community of human and medical geneticists, including an enduring diagnostic and interpretive technology, dermatoglyphics. Old networks were not supplanted; they were re-aligned.
Forward to Better Understanding of Optical Characterization and Development of Colored Polyamides for the Infra-Red/Laser Welding, Part II - Family of Colored Polyamides
Authors: Kagan Val , Chambers Al , Bray Robert 
Published: April 2003

Recent developments were oriented towards optical characterization (laser transmission, absorption, etc.) at a wide range of the infrared wavelengths and optimized mechanical performance of polyamides (PA) for the infrared/laser through-transmission welding technology (TTLW). The influence of coloring technology and type of pigments being used was also analyzed. During this study, recommendations were developed for optimizing the non carbon black pigment loading in various non-reinforced and fiber-glass-reinforced PA 6 grades. Additionally, we will discuss the efficiency of an advanced method of J - color technology (structural methods of coloring effects) for TTLW of the colored PA based plastic.
Axial Loading and Buckling Response Characteristics of Pultruded Hybrid Glass-Graphite/Epoxy Composite Beams
Authors: Ranganathan Swaminathan , Mantena P. Raju 
Published: April 2003

The effects of hybridization on the buckling characteristics of flat pultruded glass-graphite/epoxy composite beams has been investigated. Theoretical buckling loads were obtained based on Euler’s formulation. Finite element models were constructed with different beam dimensions and end constraint conditions to simulate buckling. Experiments were conducted to verify and validate the theoretical and finite element results. The experimental results were found to be consistent with the theoretical and finite element models. The buckling characteristics of composites showed that buckling strengths improve with increase in graphite fiber content. The improvements were more pronounced when glass fibers were replaced with graphite fibers located in the outer layers of the composite. The effectiveness of hybridization for improving the buckling performance of composite beams is highlighted.
Synthesis, Physical Properties and Preliminary Investigation of Hemocompatibility of Polyurethanes from Aliphatic Resources with Castor Oil Participation
Authors: Szelest-Lewandowska A. , Masiulanis B. , Klocke A. , Glasmacher B. 
Published: April 2003

The synthesis of polyurethanes (PURs) from oligoetherdiol, two low molecular diols, castor oil and 4,4′-Methylenebis(cyclohexylisocyanate) is described. These polymers are characterized by measurements of the mechanical bulk and surface properties, preliminary investigation of compatibility with human blood and calcification in static conditions. The critical surface energy of synthesized PURs is similar to the critical surface energy of natural surfaces. Material-induced hemolysis and the changes of platelet counts in blood samples after contact with PURs are very low. Static seven-weeks-calcification testing in a synthetic calcification fluid did not indicate calcification by optical density measurements and by visual inspection and computer image processing of the X-ray films for PURs with and without castor oil.
Adhesion of Thermoplastic Matrices to Carbon Fibers: Effect of Polymer Molecular Weight and Fiber Surface Chemistry
Authors: Drzal L. T. , Raghavendran V. K. 
Published: April 2003

A structure property study between the interfacial adhesion and the polymer molecular weight, fiber chemistry and processing temperature in thermoplastic composites was undertaken. In the first phase of the study, four different molecular weight grades of pure bisphenol A polycarbonate (BPA-PC) and three different consolidation temperatures were used. Molecular weight and processing temperatures were found to have significant effect on interfacial adhesion, with a major increase in adhesion between the low molecular weight grade, which is below the critical molecular weight and the next higher molecular weight grade and a monotonous increase, but to a lesser degree above the critical limit. Further, the study shows that the interface might affect the segregation of polymer chains by their molecular weight resulting in a higher concentration of low molecular weight chains at the interface and consequent loss in mechanical properties [1]. In the second phase of the study, Hercules IM7 carbon fiber with four different levels of proprietary oxidative surface treatment and subsequent hydrogen passivation were employed to determine the effects of fiber chemistry on the interfacial adhesion. It was observed that, differing amount of surface oxygen functionalities have no effect on the level of adhesion, indicating insignificant polar or hydrogen bonding interactions between the fiber and the matrix. The level of adhesion was also found to be very weakly dependent on mechanical interlocking between the fiber and the matrix. In the third phase of the study, BPA-PC and polymethyl methacrylate (PMMA) were grafted on the surface of carbon fiber to study the effect of grafted chain length and entanglement on improvement in adhesion over ungrafted fiber composites. Grafting polymer chains to the fiber surface produced a penetrable interface, which improved adhesion levels by 25-100% over the ungrafted composites. The improvement in adhesion was independent of molecular weight of the grafted chains.
Carbon-Fiber Reinforced Thermoplastic Materials for Rigidizable Space Systems
Authors: Paesano A. , Cohee D. , Palmese G. R. 
Published: April 2003

This paper describes the results obtained from a research program performed to develop thermoplastic-based composites specifically designed for deployment in low Earth orbit through inflation of compact structures followed by rigidization. For the past few years, ILC has been developing lightweight, low bulk, inflatable, rigidizable strut systems for erecting large structures in space. The composite system currently used in the development programs is a thermoset matrix (low offgassing epoxy) with carbon reinforcement. Such systems have high power requirements for erection and curing, have limited shelf life before deployment, and contain low-molecular-weight species that can result in significant offgassing. Thermoplastic systems eliminate shelf-life constraints, can potentially reduce energy requirements, and should reduce offgassing. Such systems, however, must provide equivalent mechanical performance and energy requirements if they are to be a viable alternative to the currently used material system. In the research described in this paper, a number of thermoplastic systems were evaluated in conjunction with 1 k tow T300 plain-weave carbon fabric as reinforcement. Three thermoplastic resin candidates were selected: polypropylene (PP), high-density polyethylene (HDPE), and glycol-modified polyester terephthalate (PETG). This selection was based on the physical, mechanical, and thermal properties of the systems as well as the commercial availability of these systems in thin sheets.
Interaction between a Screw Dislocation and a Three-Phase Circular Inhomogeneity with Imperfect Interface
Authors: Sudak L. J. 
Published: April 2003

Analytical expressions are obtained for the elastic stress fields due to the presence an exterior screw dislocation interacting with a three-phase circular inhomogeneity. In addition, the force on the dislocation is also derived. The bonding at the inhomogeneity—interphase interface is considered to be imperfect with the assumption that the interface imperfections are constant. On the remaining boundary, that being the interphase—matrix interface, the bonding is assumed to be perfect. The equilibrium position of the dislocation is discussed in detail for various imperfect interface conditions, interphase layer thicknesses and material property combinations. The results demonstrate that the relative thickness of the interphase layer, the influence of the imperfect bonding condition and the material property combinations are manifested by their effects on the equilibrium position and subsequent stability of the dislocation.
Failure Mechanisms and Modelling of Impact Damage in Sandwich Beams - A 2D Approach: Part I - Experimental Investigation
Authors: Shipsha Andrey , Hallström Stefan , Zenkert Dan 
Published: April 2003

This paper addresses the effect of low velocity impact damage on post-impact failure mechanisms and structural integrity of foam core sandwich beams subjected to edgewise compression, shear and bending load cases. The study deals with a 2D configuration, where a sandwich beam is impacted by a steel cylinder across the whole width of the specimen. The impact damage is characterised as indentation of the core with sub-interface damage seen as a cavity while the GFRP faces remain virtually unaffected by the impact. Digital speckle photography (DSP) analysis is employed for in situ monitoring of crushing behaviour in the foam core during static indentation of sandwich specimens. The static shear strength of impact-damaged sandwich beams is compared with specimens with fabricated sub-interface cracks of the same length. DSP analysis reveals that the face-core interface in the peripheral regions of 2D impact damage is not entirely separated. The crack analogy is thus not fully representable since the surfaces remain bridged resulting in higher strength, when compared with fabricated cracks. The post-impact resistance to compressive loads is lower than for the specimens with fabricated cracks due to the presence of the cavity and the crushed core with reduced foundation stiffness support. The properties of crushed foam core are experimentally determined as they appear to be important for accurate modelling and analysis of the residual strength of sandwich beams. Modelling and post-impact analysis of the specimens with impact damage is elaborated in detail in part II of this study.