bluuebunny/crossref_metadata_2025 huggingface dataset:
Factor Analysis of the KeyMath—Revised Normative Update Form A
Authors: Williams Thomas O. , Fall Anna-Maria , Eaves Ronald C. , Darch Craig , Woods-Groves Suzanne
Published: May 2008

The factor structure of the KeyMath—Revised Normative Update (KMR-NU) Form A was analyzed using data from a sample of 130 students. The KMR-NU is composed of 13 subtests that are purported to measure three important aspects of math ability: Basic Concepts, Operations, and Applications. A confirmatory factor analysis employing scaled scores from the 13 subtests was used to evaluate the model fit of the hypothesized three-factor model. The results of the analysis did not support the three-factor model. Follow-up exploratory factor analyses were conducted to determine if other models might provide a better model fit for the data. The results were consistent with the only factor-analytic study conducted with a previous version of the KMR-NU (Walker & Arnault, 1991), which suggested that the Total Score was the only score that should be used.
Concurrent Criterion-Related Validity of Early Literacy Indicators for Middle of First Grade
Authors: Burke Mack D. , Hagan-Burke Shanna
Published: May 2008

The purpose of this study was to examine the concurrent criterion-related (or convergent) validity of first grade measures from the Dynamic Indicators of Basic Early Literacy Skills (DIBELS; Good & Kaminski, 2002). The DIBELS subtests of Phoneme Segmentation Fluency, Nonsense Word Fluency, Oral Reading Fluency, Retell Fluency, and Word Use Fluency were administered to 213 first graders in the middle of the school year, along with the Test of Word Reading Efficiency (TOWRE; Torgesen, Wagner, & Rashotte, 1997), a norm-referenced test with documented technical adequacy. Results from correlation, regression, and factor analyses indicated that the DIBELS subtests of Oral Reading Fluency and of Nonsense Word Fluency had the strongest associations with the TOWRE subtests.
Using Math and Reading Curriculum-Based Measurements to Predict State Mathematics Test Performance
Authors: Jiban Cynthia L. , Deno Stanley L.
Published: May 2008

This study investigated the technical adequacy of 3 simple, 1-min curriculum-based measurements (CBM) for predicting third (n = 35) and fifth (n = 49) graders' performance on a state standards test of mathematics. Measures included 2 numeric CBMs: a traditional basic facts measure and a new “cloze” math facts measure, designed to require deeper understanding of fact families. A silent reading measure served as third predictor CBM. Results indicated that reliability and criterion validity of 1-min administrations were insufficient. When scores from 2 administrations were aggregated, moderate correlations were achieved. Results of aggression analysis showed that reading and cloze math measures each made significant unique contributions to explaining performance on the state math test and together explained 52% of variance at fifth grade and 27% at third grade.
An Evaluation of Curriculum-Based Measurement of Mathematics Word Problem—Solving Measures for Monitoring Third-Grade Students' Mathematics Competence
Authors: Leh Jayne M. , Jitendra Asha K. , Caskie Grace I. L. , Griffin Cynthia C.
Published: May 2008

The purpose of this study was to examine the tenability of a curriculum-based mathematical word problem-solving (WPS) measure as a progress-monitoring tool to index students' rate of growth or slope of achievement over time. Participants consisted of 58 third-grade students, who were assessed repeatedly over 16 school weeks. Students were measured once every 2 weeks on WPS and once each week on mathematics computation. Results provided corroborating data across the two measures and support the adequacy of the WPS measure for monitoring student progress. Findings of slope data are also discussed in terms of mathematical grade-level status (low-performing, LO; average-performing, AV).
How to Complete a Summary of Performance for Students Exiting to Postsecondary Education
Authors: Dukes Lyman L. , Shaw Stan F. , Madaus Joseph W.
Published: May 2008

The Individuals with Disabilities Education Improvement Act of 2004 mandates that students with disabilities graduating or aging out of the P—12 school system be provided with a summary of academic achievement and functional performance (SOP). The SOP should provide the student with one document that summarizes available formal and informal assessment data. This article presents an overview of the SOP, as well as an example SOP for a hypothetical student. The SOP form used in this article is based on the template developed by the National Transition Assessment Summit, which has been ratified by seven national and international professional disability organizations.
The Summary of Performance as Transition “Passport” to Employment and Independent Living
Authors: Kochhar-Bryant Carol A.
Published: May 2008

Individuals with moderate to significant disabilities experience the most serious challenges in accessing employment and independent living when they exit high school. Therefore, the process of transition assessment conducted in school should be structured to provide relevant information for adult service providers and employers. For individuals with employment and independent living as their postsecondary goals, the Summary of [academic and functional] Performance (SOP) required by the Individuals with Disabilities Education Improvement Act of 2004 (IDEIA) can serve as a powerful “passport” that promotes access, accommodation, and self-determination upon exit from school. This article discusses the value and structure of the SOP for individuals with employment and independent postsecondary goals. It provides an example SOP for a student that demonstrates the relevance of formal and informal data as the student makes the transition from high school to employment.
High-Stakes Test Accommodations
Authors: Banerjee Manju , Shaw Stan F.
Published: May 2008

Given the latest reauthorization of the Individuals with Disabilities Education Act (IDEA) and evolving views on the identification of cognitive disabilities in special education, many high school graduates with learning disabilities and/or attention-deficit/hyperactivity disorder will have a Summary of Performance (SOP) in lieu of a recent psychoeducational evaluation as their primary documentation of disability from high school. This article discusses potential challenges faced by high school students in establishing eligibility for high-stakes test accommodations for college. There is skepticism regarding the SOP document in terms of satisfying established disability documentation requirements and documentation review criteria of testing agencies that administer college admission exams such as the SAT and the Graduate Record Examination. Recommendations for documentation of disability by high school personnel, as well as disability documentation review policies for high-stakes testing agencies, are proposed.
Self-Determination in Secondary Transition Assessment
Authors: Field Sharon , Hoffman Alan
Published: May 2008

Self-determination knowledge and skills are important life skills for success throughout one's life. Therefore, it is important to assess the component skills that lead to self-determination so that appropriate instructional programs, supports, and accommodations to increase student self-determination can be provided. By involving students and families as important team members in the assessment process, valuable information can be gathered, student and family ownership of assessment results is increased, and support for student self-determination is demonstrated. A self-determination approach to assessment can help transition teams gather information about students' needs, strengths, interests, and preferences so that appropriate transition goals can be established. A self-determination focus in assessment can also help ensure that pertinent information is included in students' summaries of performance. Suggestions for practical strategies to promote and assess student self-determination through transition assessment are provided.
Assessment for Eligibility Under IDEIA and the 2006 Regulations
Authors: Yell Mitchell L. , Drasgow Erik
Published: May 2008

In this article, the authors briefly examine the legal requirements for assessing students' eligibility for special education services. They then analyze the major changes regarding assessment for eligibility determination in the Individuals with Disabilities Education Improvement Act (IDEIA) passed in 2004 and the regulations implementing the law, published in August 2006. (See the appendix for a description of the changes in IDEIA regarding eligibility determination; these changes are significant and will alter the ways in which school-based teams conduct the eligibility determination process.) Finally, they analyze school districts' obligations under IDEIA and provide suggestions for ensuring that the eligibility process is both educationally appropriate and legally correct. Because individual states will need to align their special education rules and regulations to those of IDEIA, readers will need to monitor developments in their respective states to determine how the new provisions will affect local school districts.
Item-Level Effects of the Read-Aloud Accommodation for Students With Reading Disabilities
Authors: Bolt Sara E. , Thurlow Martha L.
Published: May 2008

Research support for providing a read-aloud accommodation (i.e., having an individual read test items and directions aloud) to students with disabilities has been somewhat limited, particularly when merely examining effects of the accommodation on overall test scores for general groups of students with disabilities. We examined data on accommodated and nonaccommodated performances of students with specific reading disabilities on math test items anticipated to be highly sensitive to accommodation effects due to their level of reading and math difficulty. We conducted analyses across 3 consecutive years of data from an elementary and middle school statewide assessment program. Within the elementary data set we identified a significant Accommodation Group × Reading Difficulty interaction effect, such that the accommodation appeared to more positively impact student performance on items that were classified as difficult to read. We describe other identified effects and discuss limitations of the study, as well as implications.
Measuring the Enacted Curriculum for Students With Significant Cognitive Disabilities
Authors: Karvonen Meagan , Wakeman Shawnee Y. , Flowers Claudia , Browder Diane M.
Published: May 2008

Based on recent federal legislation, alternate assessments for students with disabilities may now be based on alternate achievement standards, modified achievement standards, or grade-level achievement standards. Although all students with disabilities must access the general curriculum, those with significant cognitive disabilities often do so through extensions of grade-level content standards. Because curriculum is individualized for students with disabilities, experts cannot immediately apply to this population the methods for examining the taught curriculum in general education. The purpose of this article is to describe the development and use of a method for examining the enacted curriculum for students who take alternate assessments. We present initial item development, survey blueprint, expert review, and pilot test findings. Experts can use this tool to investigate the alignment of curriculum with alternate assessments and state standards and to design professional development for educators learning to access the general curriculum.
Investigation of the Psychometric Attributes of the Test of Silent Contextual Reading Fluency
Authors: Sherry Mee Bell  , McCallum R. Steve , Kirk Emily R. , Fuller Emily J. , McCane-Bowling Sara
Published: May 2008

The purpose of this study was to examine the psychometric integrity of the Test of Silent Contextual Reading Fluency (TOSCRF) by D. D. Hammill, J. L. Wiederholt, and E. A. Allen (2006). The TOSCRF is a recently published assessment of reading fluency for ages 7 years 0 months to 18 years 11 months that can be administered individually or in a group. The TOSCRF has 4 alternate forms and is brief; administration time is approximately 10 min. Because of its brevity, availability of alternate forms, and the possibility of group administration, the TOSCRF holds promise as an efficient screening and progress-monitoring tool. The authors report evidence of reliability and validity but further, independently obtained validity evidence is needed.
Martensitic transformation and magnetic properties of Fe–24·5%Ni–4·5%Si alloy
Authors: Gungunes H. , Yasar E. , Kilic A. , Durlu T. N.
Published: May 2008

The effect of austenitising temperature and cooling rate on the morphology and magnetic properties of martensite in Fe–24·5%Ni–4·5%Si alloy has been studied by means of scanning electron microscopy, Mössbauer spectroscopy and AC susceptibility. Martensite morphology was found to be closely dependent on the austenitising temperature and cooling rate. The changes in volume fraction of martensite and austenite phases, the internal magnetic field of martensite phase and the isomery shift values have been determined by Mössbauer spectroscopy. The Mössbauer study revealed that the martensite volume fractions increased with increasing austenitising temperature and cooling rate. Also internal magnetic field of martensite was decreased by increasing the martensite volume fractions. AC magnetic susceptibility measurements showed that the Neel temperatures TN and the magnetic susceptibility χ increase with increasing austenitising temperatures.
Erosive–corrosive wear behaviour of Fe–TiC and cobalt based layers separately deposited on En31 steel
Authors: Modi O. P. , Prasad B. K. , Chrysanthou A. , Deshmukh V. P. , Shah A. K.
Published: May 2008

Observations pertaining to the erosive–corrosive wear behaviour of samples of En31 steel hardfaced separately with Fe–TiC and a commercial cobalt based material are reported in the present investigation. Erosion–corrosion tests were carried out by the sample rotation technique in 3·5%NaCl solution for varying test durations of 8–32 h (corresponding traversal distances 136–544 km) at a fixed traversal speed of 4·71 m s−1. The effect of the hardfaced layer on the wear behaviour was assessed through testing one set of each of the hardfaced and substrate steel samples under identical test conditions. The wear rate increased initially with traversal distance, attained the maximum and decreased thereafter. In the case of the steel substrate, the wear rate increased once again towards the final stage of testing. Hardfaced layers exhibited substantially decreasing wear rate compared with the substrate. Moreover, the performance of the Fe–TiC composite layer was intermediate between those of the cobalt based hardfacing material and the substrate. The observed response of the samples has been substantiated through their affected surface and subsurface characteristics.
Stochastic modelling of the small disc creep test
Authors: Evans M. , Wang D.
Published: May 2008

Obtaining accurate estimates of remanent creep life is currently of great importance to the power generating industry. The small disc creep test promises to be a useful way forward in this respect and this paper develops a stochastic finite element model of the small creep disc test. The model can be considered as a stochastic version of that used by the author, which is based on realistic creep deformations laws, including strain hardening, thermal softening and damage accumulation for 0·5Cr–0·5Mo–0·25V steel. This extension was necessary to validate the models predictions in the presence of the substantial experimental scatter that is present in existing minidisc test data. It is shown that the models predictions are capable of replicating the available experimental data to be within the approximate 99% confidence intervals for the model.
Influence of nodule count on fatigue properties of ferritic thin wall ductile iron
Authors: Caldera M. , Chapetti M. , Massone J. M. , Sikora J. A.
Published: May 2008

The present work focuses on the study of the influence of nodule count on the fatigue resistance of ductile iron. Fatigue tests were carried out on specimens taken from thin wall ductile iron plates of 2 and 4 mm thickness and standard Y blocks of 12·7 mm thickness, showing nodule counts ranging between 1800 and 300 nod mm−2. All samples were ferritised before testing to obtain a homogeneous ferritic matrix. The results showed a large dispersion of fatigue strength values. Nevertheless, careful examination of the fracture surfaces showed the presence of very small casting defects on many test samples. When only the results measured on sound test samples were accounted for, a significant increase in fatigue strength was found as the nodule count increases. Casting defects, particularly microshrinkage, revealed by scanning electron microscopy on the fracture surfaces, were responsible for the premature failure, due to shortening of the crack initiation stage. The fatigue lives measured experimentally were compared with estimations based on the fracture mechanics theory.
Effect of prestrain on aging behaviour of directly air cooled copper added titanium–boron microalloyed steels
Authors: Ghosh S. K. , Haldar A. , Chattopadhyay P. P.
Published: May 2008

The present investigation concerns effect of prestrain on the precipitation of Cu during aging of directly air cooled Ti–B microalloyed steels. The differential scanning calorimetry studies allow to identify that precipitation of Cu is most prominent between 350 and 500°C. Prestraining of the directly air cooled samples has broadened the temperature range for Cu precipitation with perceptible overlapping with the peaks due to other low temperature reactions like recovery and/or tempering. Fifty per cent prestraining of 1·5 wt-%Cu added steel before aging triggered the precipitation reaction at a temperature ∼320°C with pronounced decrease in the activation energy values from 172 to 116 kJ mol−1. Microstructural changes due to prestraining are evident in the micrographs obtained from transmission electron microscope as deformed ferrite laths and formation of cell structures therein. While 15–50% prestraining has increased the strength without much deterioration in ductility; aging of the prestrained samples has improved the strength and ductility concomitantly.
Influences of microstructure on service properties of 5Cr21Mn9Ni4N heat resistant alloy
Authors: Xu X. L. , Yu Z. W. , Wang J.
Published: May 2008

The plates of four diesel engine exhaust valves used in a truck failed when servicing for 2000 h, which are made of 5Cr21Mn9Ni4N (21-4N) heat resistant alloy. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction were performed on the plate material of the failed valves and a new valve. The results show that the plate material before service is composed of first carbides (Cr23C6) and γ austenite matrix. However, appearance of the lamellar structure and plate-like precipitates within the grain is the general metallurgical features of the plate material of the failed valves, which indicates that the austenite matrix decomposed in service. XRD and electron diffraction results demonstrate that the lamellar structure is mainly composed of Cr23C6 and γ austenite, coexisting CrN phase, which formed by the discontinuous precipitation mechanism. Electron diffraction shows that the convex lens-like CrN phases precipitate within the grain, which formed by the continuous precipitation mechanism. Fractographic studies indicate that the fatigue is the dominant failure mechanism of the three valves and burning-through occurred on the plate of another failed valve. Formation of the lamellar structure and plate-like precipitations within the grain is mainly responsible for the failure of the valves. Isothermal aging tests were conducted on the plate material from the new valve to study the material stability at high temperatures. The microstructure development during aging was observed by SEM and optical microscopy. The influence of the microstructure on the service properties was discussed and possible failure causes of the valves were assessed.
Effects of nitrogen partial pressure on microstructure, morphology and N/Ti ratio of TiN films deposited by reactive magnetron sputtering
Authors: Yang K. , Jiang J. Q. , Gu M. Y.
Published: May 2008

TiN films were deposited on Si(111) substrates at different nitrogen partial pressures with reactive magnetron sputtering. The crystal structure and preferred growth orientation of the films were determined using X-ray diffraction (XRD) analysis. Their morphology and composition were analysed using field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS). It is found that with the increase in nitrogen partial pressure, the growth of TiN films varies from the {111} preferred orientation to the {100} preferred orientation and the deposition rate of TiN films decreases. When the {111} preferred orientation is presented, TiN films reveal a kind of surface morphology of triangular pyramid with right angles; while the {100} orientation is dominant, TiN films characterise another kind of domelike surface morphology. Furthermore, the N/Ti ratio of the TiN films first increases, then decreases and increases again as nitrogen partial pressure enlarges.
Friction and wear properties of permanent mould cast AZ91D magnesium alloy
Authors: Chen T. J. , Ma Y. , Li B. , Li Y. D. , Hao Y.
Published: May 2008

The friction and wear properties of permanent mould cast AZ91D magnesium alloy were investigated under dry reciprocating sliding conditions by using a ball-on-disk machine. The results indicated that the wear resistance of the alloy was relatively poorer than those of the other commercial alloys. The wear rate per sliding distance continuously decreased while the wear rate per testing time linearly increased with the increase in reciprocating frequency. The friction coefficient slowly decreased with the frequency. As the load increased, both the wear rates increased while the friction coefficient first decreased, then increased and finally decreased again. Under low frequency or load, oxidation wear or micromachining wear dominated. As the frequency or load increased, the dominative mechanism changed in turn to plastic deformation induced wear, severe deformation accompanied by severe adhesion wear and smear wear. The work hardening and thermal oxidation of the contact surfaces played an important role for the wear behaviour.
Optimal parameters for low and high voltage electron beam welding of AZ series magnesium alloys and mechanism of weld shape and pore formation
Authors: Chi C.-T. , Chao C.-G. , Liu T.-F. , Wang C.-C.
Published: May 2008

The dependence of ultimate tensile strength (UTS) on the parameters of low voltage and high voltage electron beam welding (LV- and HVEBW) has been analyed by changing one factor at a time (COFAAT) and by Taguchi's method for AZ series magnesium alloys. COFAAT is a conventional method for trend analysis of each parameter. However, its cost is high and a long time is needed, and interactions between parameters are ignored. On the other hand, Taguchi's method cannot only reduce the number of experiments, but also provide precise optimum parameters and predicted UTS even when a few data points are lost. According to the results of analysis of variance, the strength of a weldment is affected by oscillation of the beam, the focal position, the welding speed, the accelerating voltage, the beam current and stress relief, in order of impact. The general trend is for the optimum parameters to include a non-oscillating beam, focus at the bottom and no stress relief. With regard to welding speed, accelerating voltage and beam current, there are no specific trends. Finally, the differences in welds between LV- and HVEBW for AZ series forged alloys have been examined to study the mechanism of pore formation, which results from the dissolution of precipitates to reform molecular oxygen. It is also emphasised that the area and shape of the weld cross-section are related to the input power and welding speed.
Signature image stability and metal transfer in gas metal arc welding
Authors: Simpson S. W.
Published: May 2008

This work presents a method for determining a stability index during welding by comparing signature images calculated successively from the welding voltage and current data. It is shown that, with a reasonable choice for the signature image window scaling, the stability index agrees with welding experience in the common gas metal arc welding transfer modes of short circuiting and spray transfer and reflects the decrease in stability inherent in the globular transfer mode. The effect of changing welding consumables, wire and shielding gas, is illustrated. The connection between the stability index and metal transfer phenomena is investigated, and it is shown that very detailed aspects of metal transfer are reflected in the stability index. It is concluded that the signature image stability index not only provides valuable data on the operating regions of welding processes, but also gives information which otherwise would only be available from cumbersome optical diagnostics.
Coactivator function of RIP140 for NFκB/RelA-dependent cytokine gene expression
Authors: Zschiedrich Inka , Hardeland Ulrike , Krones-Herzig Anja , Berriel Diaz Mauricio , Vegiopoulos Alexandros , Müggenburg Johannes , Sombroek Dirk , Hofmann Thomas G. , Zawatzky Rainer , Yu Xiaolei , Gretz Norbert , Christian Mark , White Roger , Parker Malcolm G. , Herzig Stephan
Published: May 2008

Inflammatory responses represent a hallmark of numerous pathologies including sepsis, bacterial infection, insulin resistance, and malign obesity. Here we describe an unexpected coactivator function for the nuclear receptor interacting protein 140 (RIP140) for nuclear factor κB (NFκB), a master transcriptional regulator of inflammation in multiple tissues. Previous work has shown that RIP140 suppresses the expression of metabolic gene networks, but we have found that genetic as well as acute deficiency of RIP140 leads to the inhibition of the proinflammatory program in macrophages. The ability of RIP140 to function as a coactivator for cytokine gene promoter activity relies on direct protein-protein interactions with the NFκB subunit RelA and histone acetylase cAMP-responsive element binding protein (CREB)-binding protein (CBP). RIP140-dependent control of proinflammatory gene expression via RelA/CBP may, therefore, represent a molecular rational for the cellular integration of metabolic and inflammatory pathways.
Dynamics of factor VIII interactions determine its immunologic fate in hemophilia A
Authors: Lacroix-Desmazes Sébastien , Navarrete Ana-Maria , André Sébastien , Bayry Jagadeesh , Kaveri Srinivas V. , Dasgupta Suryasarathi
Published: May 2008

Procoagulant factor VIII (FVIII) is either produced endogenously under physiologic conditions, or administered exogenously as a therapeutic hemostatic drug in patients with hemophilia A. In the circulation, FVIII interacts with a multitude of glycoproteins, and may be used for coagulation at the sites of bleeding, eliminated by scavenger cells, or processed by the immune system, either as a self-constituent or as a foreign antigen. The fate of FVIII is dictated by the immune status of the individual, the location of FVIII in the body at a given time point, and the inflammatory microenvironment. It also depends on the local concentration of FVIII and of each interacting partner, and on the affinity of the respective interactions. FVIII, by virtue of its promiscuity, thus constitutes the core of a dynamic network that links the coagulation cascade, cells of the immune system, and, presumably, the inflammatory compartment. We describe the different interactions that FVIII is prone to establish during its life cycle, with a special focus on players of the innate and adaptive immune response. Lessons can be learned from understanding the dynamics of FVIII interactions—lessons that should pave the way to the conception of long-lasting hemostatic drugs devoid of iatrogenic immunogenicity.
Phylogenetic placement of the enigmatic parasite, Polypodium hydriforme, within the Phylum Cnidaria
Authors: Evans Nathaniel M , Lindner Alberto , Raikova Ekaterina V , Collins Allen G , Cartwright Paulyn
Published: May 2008

Background

Polypodium hydriforme is a parasite with an unusual life cycle and peculiar morphology, both of which have made its systematic position uncertain. Polypodium has traditionally been considered a cnidarian because it possesses nematocysts, the stinging structures characteristic of this phylum. However, recent molecular phylogenetic studies using 18S rDNA sequence data have challenged this interpretation, and have shown that Polypodium is a close relative to myxozoans and together they share a closer affinity to bilaterians than cnidarians. Due to the variable rates of 18S rDNA sequences, these results have been suggested to be an artifact of long-branch attraction (LBA). A recent study, using multiple protein coding markers, shows that the myxozoan Buddenbrockia, is nested within cnidarians. Polypodium was not included in this study. To further investigate the phylogenetic placement of Polypodium, we have performed phylogenetic analyses of metazoans with 18S and partial 28S rDNA sequences in a large dataset that includes Polypodium and a comprehensive sampling of cnidarian taxa.

Results

Analyses of a combined dataset of 18S and partial 28S sequences, and partial 28S alone, support the placement of Polypodium within Cnidaria. Removal of the long-branched myxozoans from the 18S dataset also results in Polypodium being nested within Cnidaria. These results suggest that previous reports showing that Polypodium and Myxozoa form a sister group to Bilateria were an artifact of long-branch attraction.

Conclusion

By including 28S rDNA sequences and a comprehensive sampling of cnidarian taxa, we demonstrate that previously conflicting hypotheses concerning the phylogenetic placement of Polypodium can be reconciled. Specifically, the data presented provide evidence that Polypodium is indeed a cnidarian and is either the sister taxon to Hydrozoa, or part of the hydrozoan clade, Leptothecata. The former hypothesis is consistent with the traditional view that Polypodium should be placed in its own cnidarian class, Polypodiozoa.
Genomic and bioinformatics analysis of human adenovirus type 37: New insights into corneal tropism
Authors: Robinson Christopher M , Shariati Fatemeh , Gillaspy Allison F , Dyer David W , Chodosh James
Published: May 2008

Background

Human adenovirus type 37 (HAdV-37) is a major etiologic agent of epidemic keratoconjunctivitis, a common and severe eye infection associated with long-term visual morbidity due to persistent corneal inflammation. While HAdV-37 has been known for over 20 years as an important cause, the complete genome sequence of this serotype has yet to be reported. A detailed bioinformatics analysis of the genome sequence of HAdV-37 is extremely important to understanding its unique pathogenicity in the eye.

Results

We sequenced and annotated the complete genome of HAdV-37, and performed genomic and bioinformatics comparisons with other HAdVs to identify differences that might underlie the unique corneal tropism of HAdV-37. Global pairwise genome alignment with HAdV-9, a human species D adenovirus not associated with corneal infection, revealed areas of non-conserved sequence principally in genes for the virus fiber (site of host cell binding), penton (host cell internalization signal), hexon (principal viral capsid structural protein), and E3 (site of several genes that mediate evasion of the host immune system). Phylogenetic analysis revealed close similarities between predicted proteins from HAdV-37 of species D and HAdVs from species B and E. However, virtual 2D gel analyses of predicted viral proteins uncovered unexpected differences in pI and/or size of specific proteins thought to be highly similar by phylogenetics.

Conclusion

This genomic and bioinformatics analysis of the HAdV-37 genome provides a valuable tool for understanding the corneal tropism of this clinically important virus. Although disparities between HAdV-37 and other HAdV within species D in genes encoding structural and host receptor-binding proteins were to some extent expected, differences in the E3 region suggest as yet unknown roles for this area of the genome. The whole genome comparisons and virtual 2D gel analyses reported herein suggest potent areas for future studies.
An analysis of 13 patients with perforated gastric carcinoma: A surgeon's nightmare?
Authors: Kotan Cetin , Sumer Aziz , Baser Murat , Kızıltan Remzi , Carparlar M Ali
Published: May 2008

Background and Objectives

Perforation is a rare complication of gastric carcinoma and generally not diagnosed preoperatively. To clarify the clinicopathologic characteristics of patients with this condition we reviewed 13 cases of gastric cancer perforation who required emergency surgery.

Methods

A total of 13 patients with gastric cancer perforation were retrospectively reviewed. The clinicopathological features including tumor stage and survival and also the type of treatment were analyzed and compared to literature data.

Results

There were 13 patients (10 males and 3 females) with a mean age of 59.0 ± 9.56 years. The incidence of perforated gastric cancer was 9.6% among gastric carcinoma and 4.2% of all gastric perforation cases. The perforation was more frequently in stage III–IV (2–10), but one case of stage II (T3N0M0) gastric cancer was also observed. None of the patients had curative resection or radical lymph-node dissection. Six (46%) patients were treated by palliative, local surgery. Emergency gastrectomy were performed in 7 (54%) patients. Overall 30-day mortality rate was % 46. The overall survival time was 128.2 ± 184.8 days for all patients, it was 52.8 ± 52.9 days for locally treated group, and 192.9 ± 235.4 days for patients who underwent resectional surgery. The difference between the treatment groups was not significant

Conclusion

Perforation usually occurs in advanced stages of gastric cancer. These patients had a poor prognosis because of the presence of advanced cancer.
Disruption of the homeostatic balance between autoaggressive (CD4+CD40+) and regulatory (CD4+CD25+FoxP3+) T cells promotes diabetes
Authors: Waid Dan M , Vaitaitis Gisela M , Pennock Nathan D , Wagner David H
Published: May 2008

Although regulatory T cells (Tregs) are well described, identifying autoaggressive effector T cells has proven more difficult. However, we identified CD4loCD40+ (Th40) cells as being necessary and sufficient for diabetes in the NOD mouse model. Importantly, these cells are present in pancreata of prediabetic and diabetic NOD mice, and Th40 cells but not CD4+CD40– T cells transfer progressive insulitis and diabetes to NOD.scid recipients. Nonobese-resistant (NOR) mice have the identical T cell developmental background as NOD mice, yet they are diabetes-resistant. The seminal issue is how NOR mice remain tolerant to diabetogenic self-antigens. We show here that autoaggressive T cells develop in NOR mice and are confined to the Th40 subset. However, NOR mice maintain Treg numbers equivalent to their Th40 numbers. NOD mice have statistically equal numbers of CD4+CD25+forkhead box P3+intrinsic Tregs compared with NOR or nonautoimmune BALB/c mice, and NOD Tregs are equally as suppressive as NOR Tregs. A critical difference is that NOD mice develop expanded numbers of Th40 cells. We suggest that a determinant factor for autoimmunity includes the Th40:Treg ratio. Mechanistically, NOD Th40 cells have low susceptibility to Fas-induced cell death and unlike cells from NOR and BALB/c mice, have predominantly low Fas expression. CD40 engagement of Th40 cells induces Fas expression but further confers resistance to Fas-mediated cell death in NOD mice. A second fundamental difference is that NOD Th40 cells undergo much more rapid homeostatic expansion than Th40 cells from NOR mice.
Pricing an Option on Revenue from an Innovation: An Application to Movie Box Office Revenue
Authors: Chance Don M. , Hillebrand Eric , Hilliard Jimmy E.
Published: May 2008

We develop a model for valuing revenue streams from innovations. The stochastic properties of revenue from innovations create a more difficult environment in which to value options than when the underlying is a security. There is no initial revenue, and cumulative revenue cannot decrease. Revenues from innovations are characterized by different lives and different rates of the resolution of uncertainty. A common deterministic model for predicting revenue from an innovation is known as the Bass model. We embed the Bass model in a gamma process, resulting in a stochastic process with moments proportional to the mean of the Bass model. To illustrate this model we choose the valuation of options on movie box office revenue. These options enable film distributors to manage the risk of a movie, and they offer diversification opportunities for investors. We develop the econometric methodology for ex ante parameter estimation and a Bayesian updating scheme using Markov chain Monte Carlo simulation as data after release become available. Call prices obtained using the maximum likelihood (ML) parameter estimates from the full data set closely approximate the average discounted value of ex post call payouts that would have occurred at option maturity.
A Theoretical Framework for Managing the New Product Development Portfolio: When and How to Use Strategic Buckets
Authors: Chao Raul O. , Kavadias Stylianos
Published: May 2008

Developing the “right” new products is critical to firm success and is often cited as a key competitive dimension. This paper explores new product development (NPD) portfolio strategy and the balance between incremental and radical innovation. We characterize innovative effort through a normative theoretical framework that addresses a popular practice in NPD portfolio management: the use of strategic buckets. Strategic buckets encourage the division of the overall NPD resource budget into smaller, more focused budgets that are defined by the type of innovative effort (incremental or radical). We show that time commitment determines the balance between incremental and radical innovation. When managers execute this balance, they are often confounded by (i) environmental complexity, defined as the number of unknown interdependencies among technology and market parameters that determine product performance; and (ii) environmental instability, the probability of changes to the underlying performance functions. Although both of these factors confound managers, we find that they have completely opposite effects on the NPD portfolio balance. Environmental complexity shifts the balance toward radical innovation. Conversely, environmental instability shifts the balance toward incremental innovation. Risk considerations and implications for theory and practice are also discussed.
Fragmented Property Rights and Incentives for R&D
Authors: Clark Derek J. , Konrad Kai A.
Published: May 2008

Where product innovation requires several complementary patents, fragmented property rights can limit firms' willingness to invest in R&D. We consider the research intensity in multiple simultaneous R&D contests and how it depends on whether firms already hold relevant patents as well as the availability of an option to invent around. A measure of technological uncertainty is also analyzed. The multiple patent product involves an important hold-up problem that can reduce the overall R&D effort. Invent-around options moderate this problem. We also analyze targeted equilibria in which the aim of R&D can be to hold up a rival.
Long-term exercise training decreases interleukin-6 (IL-6) serum levels in subjects with impaired glucose tolerance: effect of the −174G/C variant in IL-6 gene
Authors: Oberbach Andreas , Lehmann Stefanie , Kirsch Katharina , Krist Joanna , Sonnabend Melanie , Linke Axel , Tönjes Anke , Stumvoll Michael , Blüher Matthias , Kovacs Peter
Published: May 2008

Objective

Exercise training has been shown to have anti-inflammatory effects in patients with type 2 diabetes. Changes in interleukin-6 (IL-6) serum concentrations in response to training could contribute to these beneficial effects. However, there are heterogeneous data on whether circulating IL-6 is altered by exercise training. We therefore hypothesize that genetic factors modify the individual changes in IL-6 levels after long-term training.

Research design and methods

The −174G/C variant in the IL-6 gene was genotyped in 60 subjects with impaired glucose tolerance. For a 12-month interventional study, patients were randomized into three groups: a control group (n=16) was compared with one group, which underwent a standardized training program (n=24) and another group, which was treated with 4 mg rosiglitazone once daily (n=20). At baseline, after 1, 6, and 12 months, we measured anthropometric parameters and serum concentration of IL-6 and, at baseline and after 12 months, we determined glucose tolerance and fitness level.

Results

Only in subjects carrying the SNP −174C allele did long-term exercise training result in significantly reduced IL-6 serum concentrations. Multivariate linear regression analysis identified the IL-6 genotype as a significant predictor of changes in IL-6 serum concentrations independent of age, gender and improvement in body mass index, hemoglobin (Hb)A1c, and fitness level in response to training.

Conclusions

Genetic variants in the IL-6 gene significantly modify changes in IL-6 serum concentrations in response to long-term exercise training programs. Our data suggest that genetic factors are important determinants for the individual response to anti-inflammatory effects of exercise training.
Short-term maternal psychological stress in the post-conception period in ewes affects fetal growth and gestation length
Authors: Smith Jennifer , Ferguson Drewe , Jauregui Guillermo , Panarace Martín , Medina Mariano , Lehnert Sigrid , Hill Jonathan R
Published: May 2008

Fetal development can be influenced by maternal environment in the peri-conceptional period. This study investigated the effect of maternal feed intake and psychological stress within the first 6 days after conception on embryo development and fetal growth. Superovulated ewes (n=40) were artificially inseminated with semen from one ram. Ewes were then divided into four groups (n=10): group 1 (control) was fed at maintenance level, group 2 (high) at 2× maintenance, and group 3 (low) at 0.5× maintenance on days 2–6 after conception. Group 4 (stress) was fed at maintenance level and then an intense physical and psychological stress challenge was applied for 1 h only on days 2 and 3 after conception. Embryos were recovered at day 6. A total of 113 transferable grade embryos were transferred singly into synchronized untreated recipients, while the remaining embryos (n=165) were fixed and stained for cell counts. Post-conception maternal stress or feed intake did not alter the cell count or grade of day 6 embryos. Fetuses from the stress group had longer crown-rump lengths at day 30 and longer femur length at day 58. Fetuses from the stressed and high feed groups had greater abdominal circumferences at day 85. Subsequent birth weights were not significantly different. Ewes carrying lambs from the stress treatment had shorter gestation lengths. These results show that short-term perturbations of the post-conception maternal environment have measurable effects on fetal development and gestation length.
β-Microseminoprotein in human spermatozoa and its potential role in male fertility
Authors: Anahí Franchi N , Avendaño Conrado , Molina Rosa I , Tissera Andrea D , Maldonado Cristina A , Oehninger Sergio , Coronel Carlos E
Published: May 2008

β-Microseminoprotein (MSMB) is one of the most abundant proteins in human seminal plasma. The objectives of this study were: (1) to purify MSMB from seminal plasma (SP) and generate antibodies against the pure protein; (2) to investigate the interaction of MSMB with ejaculated spermatozoa and its possible effect on the spontaneous acrosome reaction (AR); and (3) to quantify MSMB content in SP and examine its relationship with the clinical sperm parameters. MSMB was purified from SP and its presence on the sperm surface was examined by indirect immunofluorescence using a specific polyclonal antibody. The effect of MSMB on the AR was evaluated using guinea pig epididymal spermatozoa as a model. MSMB quantification assay was performed with a two-site binding ELISA using two polyclonal antibodies against MSMB. MSMB was assessed in semen samples from fertile donors (controls) and subfertile patients according to World Health Organization criteria. MSMB was detected on the sperm surface and mainly localized to the acrosomal region of the head and neck. A significant spontaneous AR inhibition was observed when guinea pig epididymal spermatozoa were preincubated with MSMB. Finally, MSMB was significantly increased in subfertile patients when compared with fertile controls (P<0.02). The association of MSMB to the sperm surface, the inhibitor effect on the spontaneous AR and the increased MSMB levels found in SP in subfertile men suggests a relationship between this protein and semen quality and a possible role in the process of fertilization.
Functional characterization and expression analysis of the androgen receptor in zebrafish (Danio rerio) testis
Authors: de Waal P P , Wang D S , Nijenhuis W A , Schulz R W , Bogerd J
Published: May 2008

The biological activity of androgens, important for male sexual differentiation and development, is mediated by the androgen receptor (AR) that binds to specific DNA recognition sites regulating the transcription of androgen target genes. We investigated androgen production by adult zebrafish testis tissue, and identified 11β-hydroxyandrostenedione, 11-ketoandrostenedione (OA), and 11-ketotestosterone (11-KT) as main products, and hence potential ligands, for the zebrafish Ar. These androgens were then included in the pharmacological characterization of the zebrafish Ar. The zebrafish Ar responded well in terms of binding and transactivation to synthetic androgens as well as to testosterone and 11-KT, and reasonably well to OA and androstenedione. In situ hybridization analysis of zebrafish testis revealed that ar mRNA expression was detected in the subpopulation of Sertoli cells contacting early spermatogonia.
HE6/GPR64 adhesion receptor co-localizes with apical and subapical F-actin scaffold in male excurrent duct epithelia
Authors: Kirchhoff Christiane , Osterhoff Caroline , Samalecos Annemarie
Published: May 2008

A role for HE6/GPR64 in male excurrent ducts in the regulation of water balance was suggested from targeted gene mutation in the mouse. Results of the present immunolocalization study strengthen this hypothesis. Employing monospecific antibodies and laser confocal microscopy, we studied the localization of the receptor protein in the human and wild-type mouse ductuli efferentes and epididymis. We show that HE6/GPR64 is specifically associated with cell types and subcellular domains involved in the process of fluid reabsorption. In the mouse, dual labelling with anti-tubulin antibodies revealed that HE6/GPR64 was absent from the (kino-) cilia of ciliated cells. Instead, the receptor protein accumulated in the non-ciliated principal cells. Specifically, strong immunofluorescence was observed in the apical compartment of these cells. Dual labelling with phalloidin and anti-ezrin antibodies revealed that in the mouse the bulk amount of HE6/GPR64 protein co-localized with the F-actin–ezrin scaffold in brush border-like microvilli of ductuli efferentes and long stereocilia of the epididymis proper. In the ductuli efferentes, HE6/GPR64 also co-localized with the subapical F-actin network immediately below the microvilli. Comparable immunostaining patterns were observed in human and mouse; however, a specific feature of the human ductuli efferentes was an intense HE6/GPR64-related labelling of crypt-like grooves or furrows of hitherto unknown function.