bluuebunny/crossref_metadata_2025_split huggingface dataset:
Freeze tolerance, supercooling points and ice formation: comparative studies on the subzero temperature survival of limno-terrestrial tardigrades
Authors: Hengherr S. , Worland M. R. , Reuner A. , Brümmer F. , Schill R. O. 
Published: February 2009

SUMMARY
Many limno-terrestrial tardigrades live in unstable habitats where they experience extreme environmental conditions such as drought, heat and subzero temperatures. Although their stress tolerance is often related only to the anhydrobiotic state, tardigrades can also be exposed to great daily temperature fluctuations without dehydration. Survival of subzero temperatures in an active state requires either the ability to tolerate the freezing of body water or mechanisms to decrease the freezing point. Considering freeze tolerance in tardigrades as a general feature, we studied the survival rate of nine tardigrade species originating from polar, temperate and tropical regions by cooling them at rates of 9, 7, 5, 3 and 1°C h–1 down to –30°C then returning them to room temperature at 10°C h–1. The resulting moderate survival after fast and slow cooling rates and low survival after intermediate cooling rates may indicate the influence of a physical effect during fast cooling and the possibility that they are able to synthesize cryoprotectants during slow cooling. Differential scanning calorimetry of starved, fed and cold acclimatized individuals showed no intraspecific significant differences in supercooling points and ice formation. Although this might suggest that metabolic and biochemical preparation are non-essential prior to subzero temperature exposure, the increased survival rate with slower cooling rates gives evidence that tardigrades still use some kind of mechanism to protect their cellular structure from freezing injury without influencing the freezing temperature. These results expand our current understanding of freeze tolerance in tardigrades and will lead to a better understanding of their ability to survive subzero temperature conditions.
Hemoglobin enhances oxygen uptake in larval zebrafish (Danio rerio) but only under conditions of extreme hypoxia
Authors: Rombough Peter , Drader Holly 
Published: February 2009

SUMMARYThe role of hemoglobin (Hb) in O2 uptake by zebrafish larvae ranging in age from 5 to 42 days postfertilization was assessed under conditions of normoxia, moderate hypoxia and extreme hypoxia. This was achieved by exposing larvae with and without functional Hb to continuously declining oxygen levels (PO2) in closed-system respirometers. Exposure to 5% CO for 2–4 h was used to render Hb effectively non-functional in terms of its ability to transport O2. Routine metabolic rate(rṀO2), critical dissolved oxygen level (Pc) and residual oxygen level(Pr) were determined and used, respectively, as indicators of response in normoxia, moderate hypoxia and extreme hypoxia. rṀO2 was defined as the average rate of O2 uptake before O2 became limiting (i.e. at high PO2s). Pc is the PO2 at which rṀO2 first becomes O2-limited and Pr is the PO2 below which larvae are no longer able to extract O2 from the ambient medium. CO poisoning had no significant impact on rṀO2 or Pc at any age, indicating that the lack of functional Hb does not impair routine O2 usage in normoxia or at moderate levels of hypoxia [down to at least 25–50 torr (1 torr≈0.133 kPa), depending on age]. Pr, however, was significantly lower overall for control larvae (6.7±1.1 torr; mean ± 95%CI) than for CO-poisoned larvae (11.2±2.1 torr). It would appear that the presence of functional Hb allows zebrafish larvae to extract O2 from water down to lower PO2s under conditions of extreme hypoxia. This is the first documented (as opposed to inferred) benefit of Hb in developing zebrafish. However, given the relatively small magnitude of the effect it is unclear if this benefit on its own is sufficient to balance the costs associated with Hb production and maintenance.
Water Vapour Adsorption of Microporous Carbon Films Prepared from Fluorinated Aromatic Polyimides
Authors: Ohta Naoto , Nishi Yoko , Morishita Takahiro , Tojo Tetsuro , Inagaki Michio 
Published: February 2009

The adsorption of water vapour onto microporous carbon films derived from fluorinated aromatic polyimides was studied at 25°C over the relative pressure range 0–0.95. The carbon films prepared were microporous with a high micropore volume ranging up to 0.44 ml/g and a sharp pore-width distribution at ca. 0.6 nm. The adsorption/desorption isotherm of water vapour onto the carbon films was of type V with slight hysteresis. The carbon films derived from fluorinated polyimides were found to exhibit a much higher water vapour adsorption at low relative pressure regions relative to commercially available activated carbon fibres, with their saturated adsorption capacities being dependent on their micropore volumes. The microporous carbon derived from the polyimide with the highest fluorine content (31.3 mass%) showed the highest saturated adsorption capacity of ca. 465 mg/g, with 90 mass% of the water vapour being adsorbed at a relative pressure below 0.46. Both the high micropore volume and the high water vapour adsorption were maintained even after heat treatment at 1300°C, although the steep uptake of water vapour was shifted to higher relative pressures to some extent.
Removal of Aniline from Waste Streams Using a Combined Adsorption and Catalytic Oxidation Approach
Authors: O'Brien J. , Curtin T. , O'Dwyer T.F. 
Published: February 2009

The focus of the work described was the development of a solid catalytic adsorbent material capable of being regenerated, with the ability of adsorbing aniline from aqueous solution and the subsequent catalytic oxidation of the adsorbed aniline. Initially, an H-ZSM-5 zeolite was loaded with copper via an ion-exchange process to enhance its catalytic activity. Experimental results indicated an aniline adsorption level of ca. 37–42 mg/g for each of the unmodified H-ZSM-5, the 0.5 w/w% Cu–ZSM-5 or the 1.4 w/w% Cu–ZSM-5 zeolites. The Langmuir adsorption model was applicable to all aniline-on-zeolite adsorption processes, with the level of aniline adsorbed being largely unaffected by a change in temperature. The kinetics of the adsorption processes, indicated that the maximum uptake of aniline occurred within 50 min of contact. Assessment of the aqueous stability of the exchanged copper on the ZSM-5 zeolites indicated minimum copper leaching within the pH range 5–11, thus providing a stable working pH range for both the 0.5 w/w% and 1.4 w/w% Cu–ZSM-5 adsorbent materials. Catalytic oxidation studies on the adsorbed aniline indicated that the presence of copper in the zeolites significantly enhanced the degradation of aniline to predominantly carbon dioxide, water and nitrogen, with the production of significantly smaller levels of nitrogen oxide, benzene and nitrogen dioxide.
Typical intellectual engagement, Big Five personality traits, approaches to learning and cognitive ability predictors of academic performance
Authors: Furnham Adrian , Monsen Jeremy , Ahmetoglu Gorkan 
Published: February 2009

Background Both ability (measured by power tests) and non‐ability (measured by preference tests) individual difference measures predict academic school outcomes. These include fluid as well as crystalized intelligence, personality traits, and learning styles. This paper examines the incremental validity of five psychometric tests and the sex and age of pupils to predict their General Certificate in Secondary Education (GCSE) test results.Aims The aim was to determine how much variance ability and non‐ability tests can account for in predicting specific GCSE exam scores.Sample The sample comprised 212 British schoolchildren. Of these, 123 were females. Their mean age was 15.8 years (SD 0.98 years).Method Pupils completed three self‐report tests: the Neuroticism–Extroversion–Openness‐Five‐Factor Inventory (NEO‐FFI) which measures the ‘Big Five’ personality traits, (Costa & McCrae, 1992); the Typical Intellectual Engagement Scale (Goff & Ackerman, 1992) and a measure of learning style, the Study Process Questionnaire (SPQ; Biggs, 1987). They also completed two ability tests: the Wonderlic Personnel Test (Wonderlic, 1992) a short measure of general intelligence and the General Knowledge Test (Irving, Cammock, & Lynn, 2001) a measure of crystallized intelligence. Six months later they took their (10th grade) GCSE exams comprising four ‘core’ compulsory exams as well as a number of specific elective subjects.Results Correlational analysis suggested that intelligence was the best predictors of school results. Preference test measures accounted for relatively little variance. Regressions indicated that over 50% of the variance in school exams for English (Literature and Language) and Maths and Science combined could be accounted for by these individual difference factors.Conclusions Data from less than an hour's worth of testing pupils could predict school exam results 6 months later. These tests could, therefore, be used to reliably inform important decisions about how pupils are taught.
Management of Gene Promoter Mutations in Molecular Diagnostics
Authors: de Vooght Karen M K , van Wijk Richard , van Solinge Wouter W 
Published: February 2009

AbstractBackground: Although promoter mutations are known to cause functionally important consequences for gene expression, promoter analysis is not a regular part of DNA diagnostics.Content: This review covers different important aspects of promoter mutation analysis and includes a proposed model procedure for studying promoter mutations. Characterization of a promoter sequence variation includes a comprehensive study of the literature and databases of human mutations and transcription factors. Phylogenetic footprinting is also used to evaluate the putative importance of the promoter region of interest. This in silico analysis is, in general, followed by in vitro functional assays, of which transient and stable transfection assays are considered the gold-standard methods. Electrophoretic mobility shift and supershift assays are used to identify trans-acting proteins that putatively interact with the promoter region of interest. Finally, chromatin immunoprecipitation assays are essential to confirm in vivo binding of these proteins to the promoter.Summary: Although promoter mutation analysis is complex, often laborious, and difficult to perform, it is an essential part of the diagnosis of disease-causing promoter mutations and improves our understanding of the role of transcriptional regulation in human disease. We recommend that routine laboratories and research groups specialized in gene promoter research cooperate to expand general knowledge and diagnosis of gene-promoter defects.
Social Welfare in Singapore and Sweden: Differences in Organisational Systems of Health Care, Social Security and Rehabilitation
Authors: Olsson Inger , Millet Patrick , Vinberg Stig , Olsson Göran , Bergroth Alf , Landstad Bodil J. 
Published: February 2009

AbstractThe aim of the study is to describe and compare the health care, social security and rehabilitation systems in Singapore and Sweden. Two fundamental differences can be identified. First, the system in Singapore are strongly oriented towards a free market system, while Sweden's demonstrates strong public control. Second, following from how the systems are oriented, Singaporeans are expected to have a higher degree of independence and control over their health care, social security and rehabilitation. It appears that Singapore has had greater success in attaining and maintaining a system of health promotion, which influences the three systems. However, the Swedish welfare system provides greater security to those who are in need of health care, social security and rehabilitation.
A Physics-Based Predictive Model for Fracture Toughness Behavior
Authors: Natishan ME , Wagenhofer M , Rosinski ST 
Published: February 2009

AbstractUsing the Zerilli-Armstrong (ZA) constitutive model for BCC materials and a combined strength-strain model of fracture, a physics model suitable for predicting the fracture toughness transition behavior of ferritic steels has been developed. The model predicts an exponential dependence of the plastic work on temperature and thus is comparable to the exponential dependence of plastic work predicted by Wallin et al. for the Master Curve. Exploring the limits of applicability of the ZA equation used as the basis for this model provides the information required to firmly establish the limits of material condition applicability of the Master Curve. Calculations based on limited data provide validation of the proposed model. The models' ability to predict shifts in transition temperature with irradiation and its application to RP vessel integrity assessment will also be discussed.
Transferability Properties of Local Approach Modeling in the Ductile to Brittle Transition Region
Authors: Laukkanen A , Wallin K , Nevasmaa P , Tähtinen S 
Published: February 2009

Abstract
Qualitative descriptive potential of local approach models for upper shelf and transition region has been well established. Models such as the Gurson-Tvergaard-Needleman and the Beremin model have been demonstrated to enable characterization of fracture phenomena over the entire transition regime. The foundation for consistent local approach characterization of material failure has been set, but quantitative application is still at developing stages. Current work addresses properties of a modified Beremin model in terms of material parameter consistency and transferability, which are taken as measures of performance with respect to quantitative applicability. Three-point bend specimen fracture toughness data of sizes 3×4×27 mm, 5×5×27 mm, 5×10×55 mm and 10×10×55 mm are simulated in the ductile to brittle transition region using finite element methods and inference of local approach parameters is performed using pointwise collocation and stochastic methods. The suitability of the calibration methods and overall model performance are evaluated and demonstrated.
Image-Based Characterization and Finite Element Analysis of Porous SMA Behavior
Authors: Qidwai MA , DeGiorgi VG , Everett RK 
Published: February 2009

Abstract
Porous shape memory alloys (SMAs) are a relatively new group of materials that are of interest because of their potential use in the design of damping and shock mitigation systems. Benefits of the material include reduced weight, high level of energy absorption through phase transformation and possible increased energy absorption through wave scattering due to porosity. Essential to the use of these materials is an understanding of the structural and shock absorbing response of the material. Constitutive models that accurately represent these characteristics are necessary. The emphasis of this research is to develop a computational methodology that will bridge the mesostructural and macrostructural features of porous SMAs. The first step in the process involves the detailed characterization of the relevant mesostructure, i.e., information about pore shape, size, volume fraction and distribution. This representative characterization can be used to produce realistic image-based finite element models. Because the resultant models have large degrees of freedom they cannot be employed to analyze large-scale structural problems. However, simply designed boundary value problems such as the dynamic uniaxial compressive loading of a bar can be used as benchmarks for the verification of phenomenological macro-constitutive models, or models that are derived using averaging methods such as the Mori-Tanaka method or the self-consistent method. In this study, an attempt is made to analyze numerically porous SMA behavior under dynamic conditions based on the representative mesostructural features. Preliminary results are obtained for selected pore volume fractions and distinct trends in material behavior are observed.
Generalized Size and Shape Description of UHMWPE Wear Debris — A Comparison of Cross-Linked, Enhanced Fused, and Standard Polyethylene Particles
Authors: Sprecher CM , Schneider E , Wimmer MA 
Published: February 2009

Abstract
Released wear debris of implants causes local inflammation of the host tissue if it is in a phagocytosable size. The purpose of this study was to compare particle size, shape, and number of three different types of UHMWPE. After wear testing, particles were isolated from the serum and analyzed using SEM. The parameters ‘equivalent circle diameter’ (ECD) and ‘equivalent shape ratio’ (ESR) were determined. Most of the generated debris was sub-micron in size. Classifying the particles into size groups demonstrated a non-linear correlation between size and shape for all three types of polyethylene: small particles were more round, large particles were more elongated. Based on this relationship, the generated number of particles and their total surface area were estimated and compared with calculations based on size alone.
Development of a Model for Testing Third Body Wear of UHMWPE Acetabular Components
Authors: Bragdon CR , O'Connor D , Muratoglu OK , Harris WH 
Published: February 2009

Abstract
The purpose of this paper is to describe the development of a new wear test protocol utilizing third body particulate debris in order to assess conventional and highly cross-linked polyethylene components. A series of tests were performed using the Boston Hip Simulator to evaluate different types of particles for possible use. Modifications to the simulator are described which ensure that the third body particles can be maintained in suspension. In this series of studies, alumina particles in a concentration of 0.15mg/cc appeared to provide the most effective challenge to the wear resistance of UHMWPE while at the same time not creating unrealistic destruction to the femoral head. In all of the experiments, under all conditions, the WIAM highly crosslinked polyethylene acetabular components resisted the effects of the third body particles and the concomitant changes in the femoral heads distinctly better than the conventional UHMWPE.
The Effects of Raw Material, Irradiation Dose, and Irradiation Source on Crosslinking of UHMWPE
Authors: Greer KW , King RS , Chan FW 
Published: February 2009

Abstract
Four Ultra-High Molecular Weight Polyethylene (UHMWPE) materials were evaluated after various irradiation crosslinking processes to determine the effects of the materials and processes on their properties for orthopaedic applications. The materials and processes included two molecular weight materials (GUR 1020 and GUR 1050), two fabricated forms (ram extruded bar and compression-molded sheet), two irradiation sources (gamma and e-beam) and multiple irradiation doses ranging from 30–120 kGy. Increasing irradiation dose led to increased crosslinking, decreased wear, and decreased toughness. The molecular weight of the starting material and the irradiation source both had effects on the final properties while the fabricated form did not. Wear testing of selected groups indicated that there was a direct correlation with irradiation dose but not with the crosslink density (as calculated from the swell ratio).
Is There a Need for TEMP Standards? A Perspective from a Biomaterials Manufacturer
Authors: Dornish M , Dessen A 
Published: February 2009

Abstract
More often than not users of biopolymers obtain their starting materials from a chemical supply company. Documentation is often lacking and the user is not aware of the fact that a biopolymer's functionality in an application is inherently linked to its characteristics. As a manufacturer of ultrapure biopolymers we have often heard the comment that “your biopolymer didn't work!” More often than not, however, the functional properties of the polymer were not appropriate for the intended use. Variability in naturally occurring biopolymers can lead to failed formulations. Alginate and chitosan are biopolymers that may be used in TEMPs. Derived from natural sources, these materials are particularly complex, and thus exhibit significant variability. Consequently, in order to understand the full range of their properties there is a need for accurate characterization of these materials. The development of standards for such TEMP starting materials is necessary to ensure product uniformity, enable more complete and precise characterization and to inform both users and manufacturers of the relationships among composition, functional properties and utility. This can only lead to more successful TEMP formulations.
Biomolecules in Tissue Engineered Medical Products (TEMPs): A Case Study of Recombinant Human Bone Morphogenetic Protein-2 (rhBMP-2)
Authors: Porter TJ , Rathore S , Rouse J , Denton M 
Published: February 2009

Abstract
rhBMP-2 is an osteoinductive protein that, when administered locally, results in the induction of new bone tissue at the site of implantation. The osteoinductive properties of rhBMP-2 first were demonstrated by implantation at ectopic (nonbony) sites in rodents. BMPs are the only protein factors known to induce new, ectopic bone. rhBMP-2/Absorbable Collagen Sponge (ACS) is a TEMP that combines rhBMP-2 with a matrix for implantation. rhBMP-2/ACS is used in long bone fracture repair and spinal fusion. The development of rhBMP-2 protein as the active ingredient in the rhBMP-2/ACS product is summarized. Four aspects of rhBMP-2 development are covered: protein structural characterization, functional characterization, purity analysis and design of comparability studies to support changes in the manufacturing process. Topics discussed include rhBMP-2 as a “biologic” and as a constituent of a combination TEMP. The lessons learned during the development of rhBMP-2/ACS may allow general insight into the development of future standards for TEMPs that contain biologically active proteins.
Auger Electron Spectroscopy in the Scanning Electron Microscope
Authors: Waldrop JR , Marcus HL 
Published: February 2009

AbstractRecent work devoted to high-spatial resolution (submicron) chemical analysis of solid surfaces by using Auger electron spectroscopy (AES) in a scanning electron microscope (SEM) is reviewed. Particular attention is given to the description of a computerized AES-SEM system and its use. Examples of applications are given, with emphasis on those in the fields of metallurgy and solid-state semiconductor devices.
Residual Stress Measurement and Analysis Using Ultrasonic Techniques
Authors: Noronha PJ , Chapman JR , Wert JJ 
Published: February 2009

Abstract
A technique which utilizes ultrasonic rediation has been developed to measure residual stresses in metals. This technique makes it possible to detect and measure the magnitude of the principle stresses and also to obtain their direction. The velocities of ultrasonic waves in materials are measured as the time to travel a fixed path length, and the change in transit time is related to the applied stress. The linear relationship obtained allows a procedure based on this principle to be used for the measurement of residual stress using surface waves and shear waves. A method for plotting stress profiles through a material using surface waves uses varying frequencies for the ultrasonic wave. A limitation of the shear wave method is considered. The system used for this technique is called the Modified Time of Flight System.