bluuebunny/crossref_metadata_2025 huggingface dataset:
A Fracture Mechanics Approach to the Prediction of Tool Wear in Dry High Speed Machining of Aluminum Cast Alloys—Part 2: Model Calibration and Verification
Authors: Bardetsky Alexander , Attia Helmi , Elbestawi Mohamed
Published: January 2007

Background. Aluminum alloys are extensively used in the automotive industry and their utilization continues to rise because of the environmental, safety and driving performance advantages. Experimental study has been carried out in this work to establish the effect of cutting conditions (speed, feed, and depth of cut) on the cutting forces and time variation of carbide tool wear data in high-speed machining (face milling) of Al–Si cast alloys that are commonly used in the automotive industry. Method and Approach. The experimental setup and force measurement system are described. The cutting test results are used to calibrate and validate the fracture mechanics-based tool wear model developed in part 1 of this work. The model calibration is conducted for two combinations of cutting speed and a feed rate, which represent a lower and upper limit of the range of cutting conditions. The calibrated model is then validated for a wide range of cutting conditions. This validation is performed by comparing the experimental tool wear data with the tool wear predicted by calibrated cutting tool wear model. Results and Conclusions. The maximum prediction error was found to be 14.5%, demonstrating the accuracy of the object oriented finite element (OOFE) modeling of the crack propagation process in the cobalt binder. It also demonstrates its capability in capturing the physics of the wear process. This is attributed to the fact that the OOF model incorporates the real microstructure of the tool material. The model can be readily extended to any microstructure of Al–Si workpiece and carbide cutting tool material.
Wear and Surface Characterization of Boronized Pure Iron
Authors: Asthana Pranay , Liang Hong , Usta Metin , Ucisik A. H.
Published: January 2007

This research investigates the morphological nature and tribological behavior of boronized pure iron using experiments combined with theoretical analysis. Samples studied were 99.97% purity iron boronized for 4h at 800°C, 875°C and 950°C, respectively. Diffusion of the borided layer was analyzed by measuring the extent of penetration of the boride to sublayers as a function of boriding time and temperature. The distribution of alloying elements from surface to interior was determined by using rf-glow discharge optical emission spectrometry. It was found that boron concentrated in the layer and the diffusion of B atoms was deeper than the layer itself. In tribological tests, friction and wear behavior under dry rolling with sliding (pseudo-rolling) and dry pure sliding conditions was investigated. The wear experiments were conducted using a modified linear reciprocating tribometer. A scanning electron microscope and atomic force microscope were used for worn surface characterization. It was found that boronizing at 875°C exhibited the best wear resistance among the samples tested. Higher wear resistance was correlated with growth of boride crystals along stronger (002) orientation. Surface grain size distribution after the boriding process was identified as an important factor for wear resistance. Different fracture and wear modes were investigated. Analysis of the wear debris gave an insight into the operative wear mechanisms. This research is beneficial in optimizing the parameters of the boronizing process to achieve better wear resistance under different contact modes.
Dosimetric prerequisites for routine clinical use of photon emitting brachytherapy sources with average energy higher than 50 keva)
Authors: Li Zuofeng , Das Rupak K. , DeWerd Larry A. , Ibbott Geoffrey S. , Meigooni Ali S. , Pérez‐Calatayud José , Rivard Mark J. , Sloboda Ronald S. , Williamson Jeffrey F.
Published: January 2007

This paper presents the recommendations of the American Association of Physicists in Medicine (AAPM) and the European Society for Therapeutic Radiology and Oncology (ESTRO) on the dosimetric parameters to be characterized, and dosimetric studies to be performed to obtain them, for brachytherapy sources with average energy higher than 50 keV that are intended for routine clinical use. In addition, this document makes recommendations on procedures to be used to maintain vendor source strength calibration accuracy. These recommendations reflect the guidance of the AAPM and the ESTRO for its members, and may also be used as guidance to vendors and regulatory agencies in developing good manufacturing practices for sources used in routine clinical treatments.
Evaluation of information‐theoretic similarity measures for content‐based retrieval and detection of masses in mammograms
Authors: Tourassi Georgia D. , Harrawood Brian , Singh Swatee , Lo Joseph Y. , Floyd Carey E.
Published: January 2007

The purpose of this study was to evaluate image similarity measures employed in an information‐theoretic computer‐assisted detection (IT‐CAD) scheme. The scheme was developed for content‐based retrieval and detection of masses in screening mammograms. The study is aimed toward an interactive clinical paradigm where physicians query the proposed IT‐CAD scheme on mammographic locations that are either visually suspicious or indicated as suspicious by other cuing CAD systems. The IT‐CAD scheme provides an evidence‐based, second opinion for query mammographic locations using a knowledge database of mass and normal cases. In this study, eight entropy‐based similarity measures were compared with respect to retrieval precision and detection accuracy using a database of 1820 mammographic regions of interest. The IT‐CAD scheme was then validated on a separate database for false positive reduction of progressively more challenging visual cues generated by an existing, in‐house mass detection system. The study showed that the image similarity measures fall into one of two categories; one category is better suited to the retrieval of semantically similar cases while the second is more effective with knowledge‐based decisions regarding the presence of a true mass in the query location. In addition, the IT‐CAD scheme yielded a substantial reduction in false‐positive detections while maintaining high detection rate for malignant masses.
Immunogenicity and Safety of Three Doses of a Bivalent (B:4:P1.19,15 and B:4:P1.7-2,4) Meningococcal Outer Membrane Vesicle Vaccine in Healthy Adolescents
Authors: Boutriau Dominique , Poolman Jan , Borrow Ray , Findlow Jamie , Domingo Javier Diez , Puig-Barbera Joan , Baldó José María , Planelles Victoria , Jubert Angels , Colomer Julia , Gil Angel , Levie Karin , Kervyn Anne-Diane , Weynants Vincent , Dominguez Francisco , Barberá Ramon , Sotolongo Franklin
Published: January 2007

An experimental bivalent meningococcal outer membrane vesicle (OMV) vaccine (B:4:P1.19,15 and B:4:P1.7-2,4) has been developed to provide wide vaccine coverage particularly of the circulating strains in Europe. A randomized, controlled phase II study (study identification number, 710158/002; ClinicalTrials.gov identifier number, NCT00137917) to evaluate the immunogenicity and safety of three doses of the OMV vaccine when given to healthy 12- to 18-year-olds on a 0-2-4 month (
n
= 162) or 0-1-6 month schedule (
n
= 159). A control group received two doses of hepatitis A and one of conjugated meningococcal serogroup C vaccine on a 0-1-6 month schedule (
n
= 157). Immune response, defined as a fourfold increase in serum bactericidal titer using a range of vaccine-homologous or PorA-related and heterologous strains, was determined for samples taken before and 1 month after vaccination; assays were performed at two laboratories. As measured at the GlaxoSmithKline (GSK) laboratory, the OMV vaccine induced an immune response against homologous or PorA-related strains (in at least 51% of subjects against strains of serosubtype P1.19,15 and at least 66% against strains of serosubtype P1.7-2,4) and against a set of three heterologous strains (in 28% to 46% of subjects). Both laboratories showed consistent results for immune response rates. The OMV vaccine had a similar reactogenicity profile for each schedule. Pain preventing normal activities occurred in approximately one-fifth of the subjects; this was significantly higher than in the control group. The immune responses induced by the bivalent OMV vaccine demonstrated the induction of bactericidal antibodies against the vaccine-homologous/PorA-related strains but also against heterologous strains, indicating the presence of protective antigens in OMVs and confirming the potential of clinical cross-protection.
Use of MAG1 Recombinant Antigen for Diagnosis ofToxoplasma gondiiInfection in Humans
Authors: Holec Lucyna , Hiszczyńska-Sawicka Elżbieta , Gąsior Artur , Brillowska-Dąbrowska Anna , Kur Józef
Published: January 2007

This paper describes the cloning, purification, and serological applications of matrix antigen MAG1 ofToxoplasma gondii. The expression system used allows the production of a large amount ofT. gondiirecombinant protein, which was assessed for its potential use in an enzyme-linked immunosorbent assay (ELISA) for detection ofT. gondiiinfection in humans. Serum samples from 117 patients with different stages of infection, along with 10 serum samples from seronegative patients obtained for routine diagnostic tests, were used. The results were compared with those of an ELISA that uses a nativeT. gondiiantigen extract. The MAG1 antigen detected antibodies more frequently from the acute stage (97.3%) than from the chronic stage (7.5%) of toxoplasmosis. Hence, this antigen may be used as a tool for detection ofT. gondiiimmunoglobulin G antibodies in persons with acute toxoplasmosis.
Age- and Serogroup-Related Differences in Observed Durations of Nasopharyngeal Carriage of Penicillin-Resistant Pneumococci
Authors: Högberg Liselotte , Geli Patricia , Ringberg Håkan , Melander Eva , Lipsitch Marc , Ekdahl Karl
Published: January 2007

Using data from an ongoing Swedish intervention project, the observed durations of nasopharyngeal carriage of penicillin-nonsusceptibleStreptococcus pneumoniae(PNSP) (MIC of penicillin G of ≥0.5 μg/ml) stratified by both pneumococcal serogroup and age of the carrier were compared. The means and 95% confidence intervals (CIs) were estimated by fitting a gamma distribution to the observed duration of carriage for each age and serogroup stratum. The mean observed duration of carriage for all cases was 37 days (95% CI, 35 to 38 days). Children below the age of 5 years carried PNSP for significantly longer periods (43 days; 95% CI, 41 to 45 days) compared with older individuals (25 days; 95% CI, 24 to 27 days). There were also differences within the group of cases below the age of 5 years, as the duration of carriage became significantly shorter for each increasing age step: <1, 1 to 2, and 3 to 4 years. In addition, patients <5 years of age carried serogroups 9 and 14 for significantly shorter periods than groups 6 and 23. Serogroup 9 was also carried for significantly shorter periods than group 19. For patients aged 5 years or older, no significant difference in carriage duration for different ages or serogroups could be noted. As young children have the longest duration of PNSP carriage, interventions aiming to reduce the prevalence in this group are of great importance. The results highlight the importance of taking both serogroup and age of the carriers into account when studying the dynamics of pneumococcal transmission in young children.
Cytotoxic T-Lymphocyte Responses to Human Papillomavirus Type 16 E5 and E7 Proteins and HLA-A*0201-Restricted T-Cell Peptides in Cervical Cancer Patients
Authors: Liu Dai-Wei , Yang Yuh-Cheng , Lin Ho-Fan , Lin Mei-Fang , Cheng Ya-Wen , Chu Chen-Chung , Tsao Yeou-Ping , Chen Show-Li
Published: January 2007

Previously, we found that human papillomavirus type 16 (HPV-16) E5 protein is a tumor rejection antigen and can induce cytotoxic T-lymphocyte (CTL) activity. Therefore, in this study, human leukocyte antigen A*0201 (HLA-A*0201)-restricted human CTL epitopes of HPV-16 E5 protein were identified using a bioinformatics approach, and the abilities of these predicted peptides to induce an immune response in HLA-A*0201 transgenic mice were confirmed by assaying E5-specific CTLs and in vitro-generated CTLs from normal peripheral blood T lymphocytes of HLA-A2-positive human donors. Second, the CTL responses to HLA-A*0201 CTL epitopes (E5 63-71 and E7 11-20) were examined in HPV-16-infected patients with HLA-A2. Third, the effect of HLA-A-type alleles on CTL activities in response to the entire E5 and E7 proteins was examined in cervical cancer patients. E5 and E7 peptides (but not the whole proteins) stimulated E5- and E7-specific CTL recall responses in HPV-16- and HLA-A2-positive cervical cancer patients, and HPV-16 E5 and E7 proteins stimulated naïve T cells in HPV-16-negative cervical cancer patients with HLA-A11 and -A24 haplotypes. In summary, this is the first demonstration that E5 63-71 is an HLA-A*0201-restricted T-cell epitope of HPV-16 E5.
Initiation at the Third In-Frame AUG Codon of Open Reading Frame 3 of the Hepatitis E Virus Is Essential for Viral Infectivity In Vivo
Authors: Huang Y. W. , Opriessnig T. , Halbur P. G. , Meng X. J.
Published: January 2007

To determine the initiation strategy of the hepatitis E virus (HEV) open reading frame 3 (ORF3), we constructed five HEV mutants with desired mutations in the ORF1 and ORF2 junction region and tested their levels of in vivo infectivity in pigs. A mutant with a C-terminally truncated ORF3 is noninfectious in pigs, indicating that an intact ORF3 is required for in vivo infectivity. Mutations with substitutions in the first in-frame AUG in the junction region or with the same T insertion at the corresponding position of HEV genotype 4 did not affect the virus infectivity or rescue, although mutations with combinations of the two affected virus recovery efficiency, and a single mutation at the third in-frame AUG completely abolished virus infectivity in vivo, indicating that the third in-frame AUG in the junction region is required for virus infection and is likely the authentic initiation site for ORF3. A conserved double stem-loop RNA structure, which may be important for HEV replication, was identified in the junction region. This represents the first report of using a unique homologous pig model system to study the molecular mechanism of HEV replication and to systematically and definitively identify the authentic ORF3 initiation site.
SPHERICAL FUNCTIONS, THE COMPLEX HYPERBOLIC PLANE AND THE HYPERGEOMETRIC OPERATOR
Authors: ROMÁN P. , TIRAO J.
Published: January 2007

In this paper, we determine all irreducible spherical functions Φ of any K-type associated to the dual Hermitian symmetric pairs (G, K) = ( SU (3), U (2)) and ( SU (2,1), U (2)). This is accomplished by associating to Φ a vector valued function H = H(u) of a real variable u, analytic at u = 0, which is a simultaneous eigenfunction of two second order differential operators with matrix coefficients. One of them comes from the Casimir operator of G and we prove that it is conjugated to a hypergeometric operator, allowing us to express the function H in terms of a matrix valued hypergeometric function. For the compact pair ( SU (3), U (2)), this project was started in [4].
A Forecasting Methodology Using Support Vector Regression and Dynamic Feature Selection
Authors: Guajardo José , Weber Richard , Miranda Jaime
Published: January 2007

Various techniques have been proposed to forecast a given time series. Models from the ARIMA family have been successfully used, as well as regression approaches based on e.g. linear, non-linear regression, neural networks, and Support Vector Regression. What makes the difference in many real-world applications, however, is not the technique but an appropriate forecasting methodology. Here, we propose such a methodology for the regression-based forecasting approach. A hybrid system is presented that iteratively selects the most relevant features and constructs the regression model optimizing its parameters dynamically. We develop a particular technique for feature selection as well as for model construction. The methodology, however, is a generic one providing the opportunity to employ alternative approaches within our framework. The application to several time series underlines its usefulness.
BOLD Coherence Reveals Segregated Functional Neural Interactions When Adapting to Distinct Torque Perturbations
Authors: Tunik Eugene , Schmitt Paul J. , Grafton Scott T.
Published: January 2007

In the natural world, we experience and adapt to multiple extrinsic perturbations. This poses a challenge to neural circuits in discriminating between different context-appropriate responses. Using event-related fMRI, we characterized the neural dynamics involved in this process by randomly delivering a position- or velocity-dependent torque perturbation to subjects’ arms during a target-capture task. Each perturbation was color-cued during movement preparation to provide contextual information. Although trajectories differed between perturbations, subjects significantly reduced error under both conditions. This was paralleled by reduced BOLD signal in the right dentate nucleus, the left sensorimotor cortex, and the left intraparietal sulcus. Trials included “NoGo” conditions to dissociate activity related to preparation from execution and adaptation. Subsequent analysis identified perturbation-specific neural processes underlying preparation (“NoGo”) and adaptation (“Go”) early and late into learning. Between-perturbation comparisons of BOLD magnitude revealed negligible differences for both preparation and adaptation trials. However, a network-level analysis of BOLD coherence revealed that by late learning, response preparation (“NoGo”) was attributed to a relative focusing of coherence within cortical and basal ganglia networks in both perturbation conditions, demonstrating a common network interaction for establishing arbitrary visuomotor associations. Conversely, late-learning adaptation (“Go”) was attributed to a focusing of BOLD coherence between a cortical–basal ganglia network in the viscous condition and between a cortical–cerebellar network in the positional condition. Our findings demonstrate that trial-to-trial acquisition of two distinct adaptive responses is attributed not to anatomically segregated regions, but to differential functional interactions within common sensorimotor circuits.
Temporal Properties of Posterior Parietal Neuron Discharges During Working Memory and Passive Viewing
Authors: Joelving Frederik C. , Compte Albert , Constantinidis Christos
Published: January 2007

Working memory is mediated by the discharges of neurons in a distributed network of brain areas. It was recently suggested that enhanced rhythmicity in neuronal activity may be critical for sustaining remembered information. To test whether working memory is characterized by unique temporal discharge patterns, we analyzed the autocorrelograms and power spectra of spike trains recorded from the posterior parietal cortex of monkeys performing a visuospatial working-memory task. We compared the intervals of active memory maintenance and fixation and repeated the same analysis in spike trains from monkeys never trained to perform any kind of memory task. The most salient effect we observed was a decrease of power in the 5- to 10-Hz frequency range during the presentation of visual stimuli. This pattern was observed both in the working-memory condition and the control condition, although it was more prominent in the former, where it persisted after cue presentation when the monkeys actively remembered the spatial location of the stimulus. Low-frequency power suppression resulted from relative refractory periods that were significantly longer in the working-memory condition and presumably emerged from local-circuit inhibition. We also detected a spectral peak in the 15- to 20-Hz range, although this was more prominent during fixation than during the stimulus and working-memory periods. Our results are in line with previous reports in prefrontal cortex and indicate that unique temporal patterns of single-neuron firing characterize persistent delay activity, although these do not involve the appearance of enhanced oscillations.
Activity-Dependent Peptidergic Modulation of the Plateau-Generating Neuron B64 in the Feeding Network of Aplysia
Authors: Koh Hae-Young , Weiss Klaudiusz R.
Published: January 2007

Many behaviors display various forms of activity-dependent plasticity. An example of such plasticity is the progressive shortening of the duration of protraction phase of feeding responses of Aplysia that occurs when feeding responses are repeatedly elicited. A similar protraction-duration shortening is observed in isolated ganglia of Aplysia when feeding-like motor programs are elicited through a prolonged stimulation of the command-like neuron CBI-2. Here, we investigate a cellular mechanism that may underlie this activity-dependent shortening of protraction duration of feeding motor programs. CBI-2 contains two neuropeptides, CP2 and FCAP. Previous work showed that CP2 shortens protraction duration of CBI-2 elicited programs. We show here that the same is true for FCAP. We also show that both CP2 and FCAP modulated the biophysical properties of a plateau-generating neuron, B64, that plays an important role in terminating the protraction phase of feeding motor programs. We find that prestimulation of CBI-2, as well as superfusion of CP2 and FCAP, lowered the threshold for activation of the plateau potential in B64. The threshold-lowering actions of CBI-2 prestimulation were occluded by superfusion of FCAP and CP2. Furthermore, at elevated temperature, conditions under which peptide release is prevented in Aplysia, prestimulation of CBI-2 does not lower the plateau-potential threshold, whereas superfusion of CP2 and FCAP does. Our findings are consistent with the hypothesis that peptides released from CBI-2 lower the threshold for activation of plateau potential in B64, thereby contributing to the shortening of protraction duration when CBI-2 is repeatedly activated.
Parameterization of the Urban Energy Budget with the Submesoscale Soil Model
Authors: Dupont Sylvain , Mestayer Patrice G.
Published: January 2007

The thermal component of the Soil Model for Submesoscales, Urbanized Version (SM2-U), is described. SM2-U is an extension on a physical basis of the rural Interactions between Soil, Biosphere, and Atmosphere (ISBA) soil model to urban areas. It evaluates the turbulent energy, moisture, and radiative fluxes at the urban canopy–atmosphere interface to provide lower boundary conditions of high-resolution mesoscale models. Unlike previous urban canopy schemes, SM2-U integrates in a simple way the physical processes inside the urban canopy: the building wall influence is integrated in the pavement temperature equation, allowing the model to compute directly the energy budget of street canyons. The SM2-U model is evaluated on the Marseille, France, city-center energy-budget components measured during the field experiments to constrain models of atmospheric pollution and transport of emissions [Expérience sur Site pour Contraindre les Modèles de Pollution Atmosphérique et de Transport d’Emissions (ESCOMPTE)] urban boundary layer (UBL) campaign (June–July 2001). The observed behavior of net radiation and heat fluxes is reproduced by SM2-U with a high level of quality, demonstrating that the influence of building walls may be well modeled by modifying the pavement temperature equation. A sensitivity analysis shows that the accurate account of wall area and the parameterization of both the fast response of artificial materials to environmental forcing variations and their heat storage capacity are essential for mesoscale simulations of the urban boundary layer; they are probably more important than accurate but complex computation of radiative trapping (effective albedo and emissivity)
Gene expression profiles of primary colorectal carcinomas, liver metastases, and carcinomatoses
Authors: Kleivi Kristine , Lind Guro E , Diep Chieu B , Meling Gunn I , Brandal Lin T , Nesland Jahn M , Myklebost Ola , Rognum Torleiv O , Giercksky Karl-Erik , Skotheim Rolf I , Lothe Ragnhild A
Published: January 2007

Background

Despite the fact that metastases are the leading cause of colorectal cancer deaths, little is known about the underlying molecular changes in these advanced disease stages. Few have studied the overall gene expression levels in metastases from colorectal carcinomas, and so far, none has investigated the peritoneal carcinomatoses by use of DNA microarrays. Therefore, the aim of the present study is to investigate and compare the gene expression patterns of primary carcinomas (n = 18), liver metastases (n = 4), and carcinomatoses (n = 4), relative to normal samples from the large bowel.

Results

Transcriptome profiles of colorectal cancer metastases independent of tumor site, as well as separate profiles associated with primary carcinomas, liver metastases, or peritoneal carcinomatoses, were assessed by use of Bayesian statistics. Gains of chromosome arm 5p are common in peritoneal carcinomatoses and several candidate genes (including PTGER4, SKP2, and ZNF622) mapping to this region were overexpressed in the tumors. Expression signatures stratified on TP53 mutation status were identified across all tumors regardless of stage. Furthermore, the gene expression levels for the in vivo tumors were compared with an in vitro model consisting of cell lines representing all three tumor stages established from one patient.

Conclusion

By statistical analysis of gene expression data from primary colorectal carcinomas, liver metastases, and carcinomatoses, we are able to identify genetic patterns associated with the different stages of tumorigenesis.
SirT1 modulates the estrogen–insulin-like growth factor-1 signaling for postnatal development of mammary gland in mice
Authors: Li Hongzhe , Rajendran Grace K , Liu Ninning , Ware Carol , Rubin Brian P , Gu Yansong
Published: January 2007

Introduction

Estrogen and insulin-like growth factor-1 (IGF-1) play important roles in mammary gland development and breast cancer. SirT1 is a highly conserved protein deacetylase that can regulate the insulin/IGF-1 signaling in lower organisms, as well as a growing number of transcription factors, including NF-κB, in mammalian cells. Whether SirT1 regulates the IGF-1 signaling for mammary gland development and function, however, is not clear. In the present study, this role of SirT1 was examined by studying SirT1-deficient mice.

Methods

SirT1-deficient (SirT1ko/ko) mice were generated by crossing a new strain of mice harboring a conditional targeted mutation in the SirT1 gene (SirT1co/co) with CMV-Cre transgenic mice. Whole mount and histology analyses, immunofluorescence staining, immunohistochemistry, and western blotting were used to characterize mammary gland development in virgin and pregnant mice. The effect of exogenous estrogen was also examined by subcutaneous implantation of a slow-releasing pellet in the subscapular region.

Results

Both male and female SirT1ko/ko mice can be fertile despite the growth retardation phenotype. Virgin SirT1ko/ko mice displayed impeded ductal morphogenesis, whereas pregnant SirT1ko/ko mice manifested lactation failure due to an underdeveloped lobuloalveolar network. Estrogen implantation was sufficient to rescue ductal morphogenesis. Exogenous estrogen reversed the increased basal level of IGF-1 binding protein-1 expression in SirT1ko/ko mammary tissues, but not that of IκBα expression, suggesting that increased levels of estrogen enhanced the production of local IGF-1 and rescued ductal morphogenesis. Additionally, TNFα treatment enhanced the level of the newly synthesized IκBα in SirT1ko/ko cells. SirT1 deficiency therefore affects the cellular response to multiple extrinsic signals.

Conclusion

SirT1 modulates the IGF-1 signaling critical for both growth regulation and mammary gland development in mice. SirT1 deficiency deregulates the expression of IGF-1 binding protein-1 and attenuates the effect of IGF-1 signals, including estrogen-stimulated local IGF-1 signaling for the onset of ductal morphogenesis. These findings suggest that the enzymatic activity of SirT1 may influence both normal growth and malignant growth of mammary epithelial cells.
Pebbles in the Mainstream: How Do We Find Them?
Authors: Cawthon Stephanie W
Published: January 2007

Significant numbers of students who are deaf and hard of hearing are educated in regular education settings, often outside the structure of established programs. Locating participants for research on deaf education has therefore become increasingly difficult. This article describes two approaches used to recruit participants in the recent online study, the National Survey of Assessment and Accommodations for Deaf and Hard of Hearing Students. The first approach is to collaborate with the professional and social networks of those who work with deaf and hard of hearing students. This involves both direct and indirect communication with organizations and individuals who can refer potential participants. Second, potential participants may also be reached via a random sample of schools nationwide. Both of these approaches are taken within the context of action research within a professional community. The article will discuss the strengths and weaknesses of these methods and make recommendations for future use in nationwide online research. Finally, the importance of sustained, active participation by deaf education practitioners is discussed in light of survey techniques and goals.
Master Teachers' Responses to Twenty Literacy and Science/Mathematics Practices in Deaf Education
Authors: Easterbrooks Susan R , Stephenson Brenda , Mertens Donna M
Published: January 2007

Under a grant to improve outcomes for students who are deaf or hard of hearing awarded to the Association of College Educators—Deaf/Hard of Hearing, a team identified content that all teachers of students who are deaf and hard of hearing must understand and be able to teach. Also identified were 20 practices associated with content standards (10 each, literacy and science/mathematics). Thirty-seven master teachers identified by grant agents rated the practices on a Likert-type scale indicating the maximum benefit of each practice and maximum likelihood that they would use the practice, yielding a likelihood-impact analysis. The teachers showed strong agreement on the benefits and likelihood of use of the rated practices. Concerns about implementation of many of the practices related to time constraints and mixed-ability classrooms were themes of the reviews. Actions for teacher preparation programs were recommended.
Sign Language Web Pages
Authors: Fels Deborah I , Richards Jan , Hardman Jim , Lee Daniel G
Published: January 2007

The World Wide Web has changed the way people interact. It has also become an important equalizer of information access for many social sectors. However, for many people, including some sign language users, Web accessing can be difficult. For some, it not only presents another barrier to overcome but has left them without cultural equality. The present article describes a system that allows sign languageâonly Web pages to be created and linked through a video-based technique called signlinking. In two studies, 14 Deaf participants examined two iterations of signlinked Web pages to gauge the usability and learnability of a signing Web page interface. The first study indicated that signing Web pages were usable by sign language users but that some interface features required improvement. The second study showed increased usability for those features; users consequently could navigate sign language information with ease and pleasure.
Assessment Practices of Professionals Serving Students Who Are Deaf or Hard of Hearing: An Initial Investigation
Authors: Luckner John L , Bowen Sandy
Published: January 2007

Assessment currently plays a critical role in American schools and society, in tasks ranging from ranking schools' effectiveness, to determining individual placement, to planning instruction. The purpose of the study was to gather data about the formal and informal assessment instruments and processes used by professionals in deaf education. Respondents indicated that statewide annual assessments are the most frequently used measures, followed by the Stanford Achievement Test series and the Woodcock-Johnson III Test of Achievement. Commonly used assessment instruments and procedures for each academic area are reported in rank order. Issues about current practices are raised, and suggestions for additional research related to assessment practices in deaf education are provided.
Buying an Income: The Market for Civil Service Positions in Indonesia
Authors: Kristiansen Stein , Ramli Muhid
Published: January 2007

In Indonesia, positions in the Civil Service are subject to hidden market transactions. The demand for stable sources of income is high, and lack of transparency makes sales possible by government officers in core positions. The recent decentralization reforms have blurred borders of responsibility and lines of reporting in the bureaucracy and facilitated increasing rent-seeking at local levels. The article reports from a study of payment for government positions in an urban and a rural district in a province in Indonesia, Nusa Tenggara Barat. The survey reveals that prices for positions are rising and vary among departments in accordance with available opportunities to boost their income. Prices are higher where many projects are available and the compensation is good. The article concludes that current practices are unethical and hurt the society and that increased transparency in employment procedures must be in place before things can get any better.
Variation in life expectancy during the twentieth century in the United States
Authors: Smith David W. , Bradshaw Benjamin S.
Published: January 2007

The National Center for Health Statistics (NCHS) reports life expectancy at birth (LE) for each year in the United States. Censal year estimates of LE use complete life tables. From 1900 through 1947, LEs for intercensal years were interpolated from decennial life tables and annual crude death rates. Since 1948, estimates have been computed from annual life tables. A substantial drop in variation in LE occurred in the 1940s. To evaluate these methods and examine variation without artifacts of different methods, we estimated a consistent series of both annual abridged life tables and LEs from official NCHS age-specific death rates and also LEs using the interpolation method for 1900–1998. Interpolated LEs are several times as variable as life table estimates, about 2 times as variable before 1940 and about 6.5 times as variable after 1950. Estimates of LE from annual life tables are better measures than those based on the mixed methods detailed in NCHS reports. Estimates from life tables show that the impact of the 1918 influenza pandemic on LE was much smaller than indicated by official statistics. We conclude that NCHS should report official estimates of intercensal LE for 1900–1948 computed from life tables in place of the existing LEs that were computed by interpolation.
The Professionalization of a Calling: Mission and Method at the New York Library Club, 1885-1901
Authors: Glynn Tom
Published: January 2007

Melvil Dewey founded the New York Library Club in 1885. It became an influential forum for exchanging ideas and debating methods and principles among practitioners of an emerging profession. Members were inspired by the mission of the public library, by an evangelical zeal to uplift the masses by bringing fine literature into their homes. At the same time, they had to develop methods of gaining intellectual control over the increasing number of titles issued by American publishers each year as well as methods of attracting readers of cheap fiction to more uplifting works. This article explores tensions between mission and methods during the early history of the club.
"Let us hasten to redeem the time that is lost": J. G. M. Ramsey's Role in the Collection and Promotion of Tennessee History
Authors: Lawrimore Erin R
Published: January 2007

The son of an early East Tennessee settler, James Gettys McGready Ramsey saw it as his patriotic and filial duty to collect, preserve, and disseminate his knowledge and grand vision of the pioneer generation to scholars, whom he believed had overlooked the region's important contributions to American history. Although an 1863 fire destroyed his collections, Ramsey's work with state and local historical societies, his correspondence with historian and fellow collector Lyman C. Draper, and the 1853 publication of his Annals of Tennessee continue to influence the compilation and interpretation of the region's historical record.
Social Capital, Urban Settings and Demographic Behavior in Latin America
Authors: Rosero Bixby Luis
Published: January 2007

Based on probabilistic samples of 12,000 adults in eight Latin American countries, this article studies two dimensions of social capital—(1) community participation and (2) trust in neighbors— and their relation with urbanization, fertility, out-migration, and crime. Its purpose is to determine whether social capital explains some of the differential demographic behavior of urban populations. The data show that social capital clearly declines with urbanization, although the urban-poor show a bit higher community participation. There is a clear gradient of increased crime and reduced social capital related to urbanization. The relationship between social capital and fertility and migration is less clear and often restricted to certain sub-populations. The urban-poor do not exhibit demographic behavior significantly different than the expected given its compositional and spatial characteristics. Basándose en muestras probabilísticas de 12.000 adultos de ocho países latinoamericanos, se estudian dos dimensiones del capital social â(1) participación comunitaria y (2) confianza en los vecinosâ y su relación con urbanización, fecundidad, emigración y crimen. El objetivo es determinar el grado en que el capital social explica el comportamiento demográfico diferenciado que presentan las poblaciones urbanas. Los datos muestran que capital social claramente disminuye con la urbanización, aunque los pobres de las ciudades exhiben una participación comunitaria algo mayor. Se observa una clara gradiente de mayor crimen y menor capital social asociados a urbanización. La relación de capital social con fecundidad y emigración es menos clara y con frecuencia restringida a ciertas subpoblaciones. Los pobres de las ciudades no muestran un comportamiento demográfico significativamente distinto de lo esperado dadas sus características composicionales y espaciales.
The Ca2+-Activated K+ChannelKCNN4/KCa3.1 Contributes to Microglia Activation and Nitric Oxide-Dependent Neurodegeneration
Authors: Kaushal Vikas , Koeberle Paulo D. , Wang Yimin , Schlichter Lyanne C.
Published: January 2007

Brain damage and disease involve activation of microglia and production of potentially neurotoxic molecules, but there are no treatments that effectively target their harmful properties. We present evidence that the small-conductance Ca2+/calmodulin-activated K+channelKCNN4/KCa3.1/SK4/IK1 is highly expressed in rat microglia and is a potential therapeutic target for acute brain damage. Using a Transwell cell-culture system that allows separate treatment of the microglia or neurons, we show that activated microglia killed neurons, and this was markedly reduced by treating only the microglia with a selective inhibitor of KCa3.1 channels, triarylmethane-34 (TRAM-34). To assess the role of KCa3.1 channels in microglia activation and key signaling pathways involved, we exploited several fluorescence plate-reader-based assays. KCa3.1 channels contributed to microglia activation, inducible nitric oxide synthase upregulation, production of nitric oxide and peroxynitrite, and to consequent neurotoxicity, protein tyrosine nitration, and caspase 3 activation in the target neurons. Microglia activation involved the signaling pathways p38 mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB), which are important for upregulation of numerous proinflammatory molecules, and the KCa3.1 channels were functionally linked to activation of p38 MAPK but not NF-κB. Thesein vitrofindings translated intoin vivoneuroprotection, because we found that degeneration of retinal ganglion cells after optic nerve transection was reduced by intraocular injection of TRAM-34. This study provides evidence that KCa3.1 channels constitute a therapeutic target in the CNS and that inhibiting this K+channel might benefit acute and chronic neurodegenerative disorders that are caused by or exacerbated by inflammation.
Cortical Modulation of Spatial and Angular Tuning Maps in the Rat Thalamus
Authors: Li Lu , Ebner Ford F.
Published: January 2007

The massive feedback projections from cortex to the thalamus modulate sensory information transmission in many ways. We investigated the role of corticothalamic feedback projections on the directional selectivity (angular tuning) of neurons in the rat ventral posterior medial (VPM) nucleus to stimulation of their principal whisker. The angular tuning properties of single VPM neurons were compared before and after epochs of electrical stimulation of layer VI feedback neurons in the ipsilateral cortex under urethane anesthesia. Microstimulation of layer VI in “matched” (homologous) barrel columns sharpens the angular tuning curves of single VPM neurons that are tuned to the same direction as the stimulation site in the cortex. Further, microstimulation rotates the angular preference of VPM neurons initially tuned to a different direction toward the direction that cortical neurons prefer. Stimulation in “mismatched” (nonhomologous) barrel columns suppresses responses without consistent effects on angular tuning. We conclude that the primary sensory cortex exerts a significant influence on both spatial and angular tuning maps in the relay nuclei that project to it. The results suggest that the tuning properties of VPM cells in the behaving animal are continually modified to optimize perception of the most salient incoming messages.
In Vitro Effects of Enamel Matrix Derivative on Microvascular Cells
Authors: Schlueter Scott R. , Carnes David L. , Cochran David L.
Published: January 2007

Background: Periodontal regeneration requires a coordinated series of events that includes not only the recruitment of periodontal ligament (PDL)‐specific cells, but vascular cells as well. The mechanisms of action of enamel matrix derivative (EMD) are poorly understood, and its effects on vascular cells are unknown. The objective of this study was to examine the extent to which EMD affects angiogenesis and PDL cell recruitment.

Methods: The effects of EMD on human microvascular endothelial cells (HMVECs) were determined by examining proliferation, chemotaxis, angiogenesis, and migration. Proliferation was determined using water‐soluble tetrazolium salt (WST)‐1 reagent. Chemotaxis was determined using microporous‐culture well inserts. Angiogenesis was assessed on plates containing matrigel. The effects of HMVECs on the migration of PDL cells were assessed by evaluating PDL cell outgrowth from collagen gels cultured in the presence of HMVECs on fibrin matrix and surrounded by fibronectin‐containing fibrin clots at 24 hours. Effects of EMD on PDL expression of vascular endothelial cell (VEGF) types (A, B, C, and D) and isoforms were determined using reverse transcription‐polymerase chain reaction (RT‐PCR). Production of VEGF, platelet‐derived growth factor (PDGF)‐AA, PDGF‐BB, PDGF‐AB, and transforming growth factor (TGF)‐β1 by EMD‐stimulated PDL cells was assessed quantitatively in conditioned media using specific enzyme‐linked immunosorbent assays (ELISAs).

Results: EMD at concentrations <‐0 μg/ml resulted in significant (P <0.05) stimulation of HMVEC proliferation. Compared to baseline, EMD also stimulated a 100% increase in HMVEC chemotaxis when PDL cells were present (P <0.05). All doses of EMD tested (25, 50, and 100 μg/ml) increased angiogenesis in vitro. HMVECs, in combination with EMD at a concentration of 100 μg/ml, stimulated a 750% increase in migration of PDL cells from collagen gels into fibrin clots compared to controls when neither was present. RT‐PCR results indicated that PDL cells expressed VEGF‐A, ‐B, and ‐C and multiple isoforms of VEGF‐A, including VEGF121, VEGF165, and VEGF189, whether or not EMD was present in the culture media. ELISAs determined a 400% increase in VEGF concentration by PDL C cells in EMD‐stimulated conditioned media and a similar increase in TGF‐β1–stimulated media.

Conclusions: It is likely that EMD stimulates angiogenesis directly by stimulating endothelial cells and indirectly by stimulating the production of angiogenic factors (VEGF) by PDL cells. Importantly, the data are consistent with the concept that EMD enhances bidirectional communication between HMVEC and PDL cells during angiogenesis associated with healing.
Calculus Removal With Diamond‐Coated Ultrasonic Inserts In Vitro
Authors: Yukna Raymond A. , Vastardis Sotirios , Mayer Elizabeth T.
Published: January 2007

Background: Efficient calculus removal is a primary goal in periodontal therapy. Diamond‐coated ultrasonic inserts (DIs) offer promise for improved scaling and were evaluated in vitro.

Methods: Extracted human teeth with moderate to severe calculus had areas of calculus (∼5 × 5 mm) delineated with small burs. Each calculus area was treated under 2.5× magnification to the point of visible root cleanliness with sharp Gracey curets (hand instruments [HIs]), plain ultrasonic inserts (PIs), or ultrasonic inserts with fine‐grit diamond coating; the latter two were used in a magnetostrictive ultrasonic instrument at a medium power setting. Each curet or insert was used for four teeth and then replaced by a new instrument. The time needed to clean each tooth/surface was recorded. The total area treated and the area of the residual calculus were calculated using an imaging analysis program.

Results: The mean time required for clinical calculus removal was 29.7 seconds for DIs, 91.9 seconds for PIs, and 49.8 seconds for HIs (all P <0.0001 from each other). Overall, the mean percentage of residual calculus was 6.3% for DIs, 5.4% for PIs, and 3.1% for HIs (significant differences between HIs and the other treatments).

Conclusions: In vitro calculus removal was faster with DIs, followed by HIs and PIs. More residual calculus was found with the DIs; however, the 1% to 3% difference (93.7% clean versus 94.6% clean versus 96.9% clean with DIs, PIs, and HIs, respectively) does not seem to be clinically significant.