bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics of offset journal bearings — revisited
Authors: Boedo S , Booker J F
Published: February 2009

‘Offset’ journal bearings provide an alternate design approach for problematic applications lacking both load reversal and adequate journal angular velocity. More than a quarter century has gone by since the first publication of a dynamic analysis for offset journal bearings (and the concept of such bearings is much older still). Since then it has been found that the ‘squeeze film’ support crucial to successful operation of these bearings can be extremely sensitive to refilling rate from cavitated film regions, requiring a mass-conservative cavitation analysis that was unavailable earlier. Additionally, the earlier analyses were based on semi-analytic approximate solutions to the Reynolds equation, rather than on later numerically exact full solutions. The present work addresses these shortcomings and attempts thereby to put the design of these unique bearings on a sounder and more reliable footing. Thus, the choice of ‘revisited’ over ‘reviewed’ in the title is a deliberate one. Rather than a simple review of previous work, the article is a revisit of the design analysis of offset journal bearings using modern methods not available to previous authors. Included are dimensional sample applications and non-dimensional parametric optimization studies showing an order of magnitudeimprovement in predicted cyclic minimum film thickness and a modest reduction in cyclic maximum film pressure.
Tribological analysis of failed resurfacing hip prostheses and comparison with clinical data
Authors: Joyce T J , Langton D J , Jameson S S , Nargol A V F
Published: February 2009

Metal-on-metal resurfacing hip prostheses offer potential benefits over total hip replacement for younger and more active patients. Although some reported clinical results of resurfacing hip prostheses are excellent, other outcomes are less positive. To aid with understanding the balance of benefits related to these devices, analysis of failed resurfacing prostheses can contribute critical insights. However, because these implants are so new there are relatively few such prostheses available for independent ex vivo analysis. From a single-surgeon clinical cohort, a number of failed resurfacing hip prostheses were obtained and studied. It was found that roughness values of the articulating surfaces had increased so that the theoretical lubrication regime would shift from the fluid film to the boundary. In turn, this would likely result in increased wear from the articulating surfaces. High ion levels were seen in the patients from whom the explants were obtained, thus supporting the hypothesis that wear was linked with failure of the explanted hip resurfacing prostheses.
Physical properties of boundary layers in angular contact ball bearings lubricated with greases containing polymers
Authors: Gatzen M M , Pape F , Poll G W G
Published: February 2009

This article describes the effect of polymer additives in lithium greases on performance and boundary layers of high-speed angular contact ball bearings. High-speed test rigs were used to run grease life tests utilizing five lithium grease variants that were derivatives from the same basic grease composition. While one was used in its plain state, the other four were blended with polymer additives. The test runs showed different operating characteristics of the greases with total service lives ( L10) ranging from 139 to 1010 h. Furthermore, the operating temperatures of the greases varied by up to 11 °C. After test run completion, surface hardness was measured on the raceways using a nanoindentation system with a triangular diamond pyramid Berkovich tip and an applied force of 1.5 mN. As a reference, a ‘virgin’ bearing was studied having not yet been in contact with grease. Thereafter, measurements were performed on samples that had been in contact with the five described greases. It is shown that polymer additives indeed can influence the properties of boundary layers, thereby affecting the bearing's service life and friction.
Friction and lubricant film thickness measurements on simulated synovial fluids
Authors: Mavraki A , Cann P M
Published: February 2009

This article is part of a research programme to study fundamental aspects of synovial fluid lubrication of artificial hip joints and focuses on the role of proteins (albumin and γ-globulin) in film formation. Friction and film thickness measurements have been carried out on a series of simple protein solutions (simulating synovial fluid SF) and bovine serum (BS). Protein solutions were prepared with different buffer solutions to simulate healthy and periprosthetic SFs. Simple bench-top tests using a ball-on-disc geometry were used to simulate hip joint articulation. All measurements were made under steady-state load and speed (5—50 mm/s) conditions.

The friction results showed that BS and simple protein solutions demonstrate boundary properties by reducing friction in the slow-speed regime. The film thickness results with BS provide evidence of the formation of an adsorbed solid surface layer (<20 nm), which is augmented by a thicker hydrodynamic film. Film thickness was fairly constant over the speed range, but tended to decrease with increasing speed. The choice of buffer solution affected the lubrication properties; much thicker films were recorded for the phosphate-buffered saline compared to 2-amino- 2-(hydroxymethyl)-1,3-propanediol protein solutions. The friction and film thickness results were time and/or rubbing distance dependent, suggesting that the formation of the deposited film was pressure/friction related.
Martronics: A philosophy for marine systems design
Authors: Sutton R , Roberts G N
Published: February 2009

In this paper the authors offer a definition for martronics. Martronics is considered to be a philosophy for marine systems design which draws upon a number of discipline areas that need to be utilized in a synergetic manner in order to obtain optimum solutions. A brief historical perspective of the development of marine control systems, which are related to the martronics philosophy, is given and a suggestion for the educational curriculum requirements for a degree course in martronics is outlined. This is followed by two different case studies which illustrate the conceptual ideas of this philosophical approach.
Wave-induced sloshing pressure in a liquid tank under irregular waves
Authors: Nasar T , Sannasiraj S A , Sundar V
Published: February 2009

The sloshing pressures on the side wall and on the top cover plate of a tank partially filled with liquid and rigidly mounted on a barge in irregular waves are investigated through physical model tests. The barge was allowed to oscillate freely in the combined degrees of excitation, i.e. sway, heave, and roll. Four liquid fill levels with aspect ratios hs/ l (where hs is the static liquid depth and l is the tank length) of 0.163, 0.325, 0.488, and 0.585 are considered for the present study. The effect of peak wave excitation frequencies on the pressure variation is studied in detail, the results of which are herein reported. It is observed that the impact pressure on the top panel of the tank is about 1.6 times the pressure observed on the side wall.
True degradation estimation of industrial equipment with fuzzy sets: A case study
Authors: Kumar E V , Chaturvedi S K
Published: February 2009

Equipment is prone to degradation during usage, and this is a continuous process. Degradation can be assessed with the help of condition indicators whose levels (near threshold values) indicate the need for maintenance action. A common phenomenon observed in process plants is that, with highly varying process and/or stressor variables, the levels of condition indicators also fluctuate a great deal and may approach threshold values suddenly. Responding to such levels of condition indicators by way of maintenance actions leads to overmaintenance, as these do not represent permanent equipment deterioration, but a combination of temporary and permanent deteriorations caused by changes in the process and/or stressor levels. Thus, there is a need to estimate the permanent deterioration, i.e. true degradation, of the equipment under these situations, excluding the temporary deterioration. The level of true degradation determines the appropriate maintenance actions to be carried out. In this paper, the authors propose a new approach to modelling the degradation process by segregating it into manifested degradation and true degradation. The first component leads to temporary equipment deterioration, and the second to permanent equipment deterioration. Estimation of the true degradation is carried out using fuzzy sets and a fuzzy inference system on the observed condition indicators and process information. Quantitative data and imprecise and vague knowledge are used to fuse into the fuzzy inference process while estimating the true degradation level. A case study on steel rolling mill equipment is considered to demonstrate the applicability of the proposed approach. Additionally, a customized equipment health acceptability criterion is developed for the given equipment using the condition monitoring database.
When I equals we: Exploring the relation between social and personal identity of extreme right‐wing political party members
Authors: Baray Gamze , Postmes Tom , Jetten Jolanda
Published: February 2009

This paper introduces the concept of self‐defining groups to explain how personal and social aspects of identity relate to each other among members of an extreme right‐wing political party. Two studies were conducted. Study 1 examined how affiliation with a social group that has clear‐cut, rigid norms and values affects the personal and social self‐concept. Participants were members of a (self‐defining) Turkish nationalist organisation (N=66) and a control group of Turkish university students (N=58). Paradoxically, high levels of national identi fication were associated with stronger personal identity. Study 2 used the same participant population (N=177) and manipulated self‐focused attention by means of a mirror. Self‐aware members reported the highest levels of identification with the nationalist organisation. Results suggest that members of this groups show no signs of ‘vanishing individuality’: although boundaries between personal and social identities are blurred, extremist group members retain a distinct and strengthened sense of personal identity. This raises some interesting questions for the concept of personal identity and how it can be informed by the content of one's social identity.
Comprehension of Television Messages by Deaf Students at Various Stages of Education
Authors: Cambra Cristina , Silvestre Núria , Leal Aurora
Published: February 2009

Since television captioning first became available in Spain, advances have occurred on two fronts: a progressive increase in the number of programs with captions and improved captioning technology. The present study explores the effectiveness of captioning through analysis of deaf viewers’ comprehension, taking into account the contribution of the program’s verbal and visual information. The study participants, comprising two groups of deaf students at different educational stages, were asked to explain what they had understood after watching a film under two conditions: voice and sound but without captions; and voice, sound, and captions. Results indicate that deaf students have difficulty accessing the information even under the voice/sound/caption condition, not only due to their level of reading ability but also to the speed of caption presentation when oral content is literally transcribed on the screen in its entirety.
Families With Young Deaf Children and the Mediation of Mathematically Based Concepts Within a Naturalistic Environment
Authors: Kritzer Karen L.
Published: February 2009

A qualitative study is described that sought to examine the relationship between young deaf children’s level of mathematics ability (“more successful” and “less successful” as defined by scores on the Test of Early Mathematics Ability–3, Ginsburg & Baroody, 2003) and the opportunities available to develop early mathematics concepts during daily life with their families. Findings indicate substantial differences between the two groups of children. Children who demonstrated higher levels of mathematics ability were found to spend a larger percentage of their day interacting with the adults around them and to experience more frequent and purposeful exposure to mathematically based concepts (number/counting, quantity, time/sequence, and categorization) at home. The findings suggest the need for an early intervention program to facilitate parents’ use of early mathematics concepts within naturalistic environments with their young deaf children to promote readiness for formal schooling.
Veteran Teachers’ Use of Recommended Practices in Deaf Education
Authors: Easterbrooks Susan R. , Stephenson Brenda H. , Gale Elaine
Published: February 2009

Deaf Education teacher preparation programs face the likelihood that their graduates may not implement evidenced-based practices they were taught once they have graduated. The literature suggests that new teachers follow the school culture where they work rather than methods and strategies taught in their preparation programs. To investigate whether teachers of students who are deaf or hard of hearing (DHH) implement recommended practices, 23 teachers from three schools for the deaf were interviewed about their implementation and use of two recommended practices: independent reading and problem solving. The guiding questions were: Do teachers of students who are DHH use independent reading and problem solving after the enculturation process? If so, to what level? If not, can a review improve their level of use? Results demonstrated, at least regarding these two practices, that teachers of students who are DHH do implement evidence-based practices in their classrooms.
Modality, Individuation, and the Ontology of Art
Authors: Matheson Carl , Caplan Ben
Published: February 2009

In 1988, Michael Nyman composed the score for Peter Greenaway's film Drowning by Numbers (or did something that we would ordinarily think of as composing that score). We can think of Nyman's compositional activity as a ‘generative performance’ and of the sound structure that Nyman indicated (or of some other abstract object that is appropriately related to that sound structure) as the product generated by that performance (ix). According to one view, Nyman's score for Drowning by Numbers — the musical work — is the product generated by Nyman's compositional activity (namely, an abstract object) and, more generally, artworks are identified with the products generated by compositional or other creative activities. Let's call this view The Product Theory. By contrast, according to another view, Nyman's score for Drowning by Numbers is the generative performance itself (namely, Nyman's compositional activity) and, more generally, artworks are identified with generative performances themselves.
Content Externalism and Brute Logical Error
Authors: Collins John M.
Published: February 2009

Externalism with respect to content is the thesis that the contents of an individual's mental states are fixed, not just by the intrinsic physical characteristics of the individual, but also in part by the external circumstances of the individual. This idea can be illustrated by means of thought experiments involving pairs of ‘twins’ who are identical with respect to their intrinsic features yet who differ mentally because of differences in their environments. The thoughts of a thirsty earthling may turn to water. Suppose that an earthling has a molecule-for-molecule twin on a very distant planet, a planet identical to Earth except that wherever Earth has H2O, Twin Earth has XYZ, which is superficially indistinguishable from water. When the twin is thirsty, her thoughts will turn instead totwater, as we may call it. Externalism about content is a metaphysical thesis, but it has epistemological implications. Many have argued that externalism is incompatible with a suitably rigorous thesis about the authoritative, introspective self-knowledge we seem to have with respect to our own thought contents.
Meaning Holism andDe ReAscription
Authors: Whiting Daniel
Published: February 2009

According to inferential role semantics (IRS), for an expression to have a particular meaning or express a certain concept is for subjects to be disposed to make, or to treat as proper, certain inferential transitions involving that expression. Such a theory of meaning isholistic, since according to it the meaning or concept any given expression possesses or expresses depends on the inferential relations it stands in to other expressions.

It is widely recognised that this holism leads to twoprima facieproblems for IRS. First, since no two speakers share the same beliefs, they will inevitably be disposed to make, or treat as correct,differentinferential transitions involving an expression. Hence, according to IRS, the same word in different mouths will possess a different meaning and be understood in different ways. It seems to follow thatcommunicationis impossible.
Predicting adult health and mortality from adolescent facial characteristics in yearbook photographs
Authors: Reither Eric N. , Hauser Robert M. , Swallen Karen C.
Published: February 2009

Several important longitudinal studies in the social sciences have omitted biomarkers that are routinely recorded today, including height and weight. To account for this shortcoming in the Wisconsin Longitudinal Study (WLS), an 11-point scale was developed to code high school senior class yearbook photographs of WLS participants for relative body mass (RBM). Our analyses show that although imperfect, the RBM scale is reliable (α = .91) and meets several criteria of validity as a measure of body mass. Measured at ages 17–18, the standardized relative body mass index (SRBMI) was moderately correlated (r = .31) with body mass index (BMI) at ages 53–54 and with maximum BMI reported between ages 16 and 30 (r = .48). Overweight adolescents (≥ 90th percentile of SRBMI) were about three times more likely than healthy-weight adolescents (10th–80th percentile of SRBMI) to be obese in adulthood and, as a likely consequence, significantly more likely to report health problems such as chest pain and diabetes. Overweight adolescents also suffered a twofold risk of premature death from all nonaccidental causes as well as a fourfold risk of heart disease mortality. The RBM scale has removed a serious obstacle to obesity research and lifelong analyses of health in the WLS. We suggest that other longitudinal studies may also be able to obtain photos of participants at younger ages and thus gain a prospectively useful substitute for direct measures of body mass.
Marriage behavior response to prime-age adult mortality: evidence from malawi
Authors: Ueyama Mika , Yamauchi Futoshi
Published: February 2009

This article examines the effect of AIDS-related mortality of the prime-age adult population on marriage behavior among women in Malawi. A rise in prime-age adult mortality increases risks associated with the search for a marriage partner in the marriage market. A possible behavioral change in the marriage market in response to an increase in prime-age adult mortality is to marry earlier to avoid exposure to HIV/AIDS risks. We test this hypothesis by using micro data from Malawi, where prime-age adult mortality has drastically increased. In the analysis, we estimate the probability of prime-age adult mortality that sample women have observed during their adolescent period by utilizing retrospective information on deaths of their siblings. Empirical analysis shows that excess prime-age adult mortality in the local marriage market lowers the marriage age for females and shortens the interval between the first sex and first marriage.
The rising share of nonmarital births: is it only compositional effects?
Authors: Ermisch John
Published: February 2009

A recent article by Gray, Stockard, and Stone contended that the increase in the proportion of births to unmarried women since 1974 in the United States was not caused by any major change in underlying fertility behavior, but rather by a decrease in the proportion of women who are married, which increased both the population at risk and the birth rate of unmarried women relative to that of married women. In this comment, I argue that the statistical test of this explanation used in the article is invalid because the variables in the analysis are not stationary time series. Correct statistical tests reject the explanation. In particular, I demonstrate persistent, nonstationary deviations from the relationships predicted by the theory advanced by Gray et al. For long periods, the proportion unmarried played only a small role in the changes in the ratio of nonmarital to marital birth rates, contrary to the theory.
Bayesian estimation of hispanic fertility hazards from survey and population data*
Authors: Rendall Michael S. , Handcock Mark S. , Jonsson Stefan H.
Published: February 2009

Previous studies have demonstrated both large gains in efficiency and reductions in bias by incorporating population information in regression estimation with sample survey data. These studies, however, assumed that the population values are exact. This assumption is relaxed here through a Bayesian extension of constrained maximum likelihood estimation applied to U.S. Hispanic fertility. The Bayesian approach allows for the use of both auxiliary survey data and expert judgment in making adjustments to published Hispanic Population fertility rates, and for the estimation of uncertainty about these adjustments. Compared with estimation from sample survey data only, the Bayesian constrained estimator results in much greater precision in the age pattern of the baseline fertility hazard and therefore of the predicted values for any given combination of socioeconomic variables. The use of population data in combination with survey data may therefore be highly advantageous even when the population data are known to have significant levels of nonsampling error.
Comment: there may be compositional effects, but they do not work that way*
Authors: Martin Steven
Published: February 2009

This analysis joins the debate on how declines in marriage have shifted the composition of the unmarried and married populations in the United States, and how compositional shifts have affected nonmarital birth rates. Gray, Stockard, and Stone (2006) presented one model for compositional effects that Ermisch (2009) challenged with alternative statistical tests. I propose an alternative model for compositional shifts based not on theory but on observed marriage and fertility patterns. The results from this alternative model are consistent with Ermisch’s findings yet support Gray et al.’s general case that compositional effects have had an important infiuence on nonmarital birth rates.
Family boundary ambiguity and the measurement of family structure: the significance of cohabitation
Authors: Brown Susan L. , Manning Wendy D.
Published: February 2009

We used data from the first wave of the National Longitudinal Study of Adolescent Health to examine family boundary ambiguity in adolescent and mother reports of family structure and found that the greater the family complexity, the more likely adolescent and mother reports of family structure were discrepant. This boundary ambiguity in reporting was most pronounced for cohabiting stepfamilies. Among mothers who reported living with a cohabiting partner, only one-third of their teenage children also reported residing in a cohabiting stepfamily. Conversely, for those adolescents who reported their family structure as a cohabiting stepfamily, just two-thirds of their mothers agreed. Levels of agreement between adolescents and mothers about residing in a two-biological-parent family, single-mother family, or married stepfamily were considerably higher. Estimates of the distribution of adolescents across family structures vary according to whether adolescent, mother, or combined reports are used. Moreover, the relationship between family structure and family processes differed depending on whose reports of family structure were used, and boundary ambiguity was associated with several key family processes. Family boundary ambiguity presents an important measurement challenge for family scholars.
Composition and decomposition in nonmarital fertility
Authors: Wu Lawrence l.
Published: February 2009

Ermisch (2009) criticized Gray, Stockard, and Stone (2006), arguing that they incorrectly tested a model positing a nonlinear relationship between the nonmarital fertility ratio and the proportion of unmarried women. I identify a different problem, which is that even if this model were to hold for a particular population, it would not in general hold for subgroups of this population; likewise, were it to hold for subgroups, it would not hold for aggregations of these subgroups.
Birds of a feather, or friend of a friend? using exponential random graph models to investigate adolescent social networks
Authors: Goodreau Steven M. , Kitts James A. , Morris Martina
Published: February 2009

In this article, we use newly developed statistical methods to examine the generative processes that give rise to widespread patterns in friendship networks. The methods incorporate both traditional demographic measures on individuals (age, sex, and race) and network measures for structural processes operating on individual, dyadic, and triadic levels. We apply the methods to adolescent friendship networks in 59 U.S. schools from the National Longitudinal Survey of Adolescent Health (Add Health). We model friendship formation as a selection process constrained by individuals’ sociality (propensity to make friends), selective mixing in dyads (friendships within race, grade, or sex categories are differentially likely relative to cross-category friendships), and closure in triads (a friend’s friends are more likely to become friends), given local population composition. Blacks are generally the most cohesive racial category, although when whites are in the minority, they display stronger selective mixing than do blacks when blacks are in the minority. Hispanics exhibit disassortative selective mixing under certain circumstances; in other cases, they exhibit assortative mixing but lack the higher-order cohesion common in other groups. Grade levels are always highly cohesive, while females form triangles more than males. We conclude with a discussion of how network analysis may contribute to our understanding of sociodemographic structure and the processes that create it.
Response to Ermisch, Martin, and Wu
Authors: Gray Jo Anna , Stockard Jean , Stone Joe
Published: February 2009

Our recent paper in Demography (Gray, Stockard, and Stone 2006) has attracted the close scrutiny of several prominent academics. Three sets of formal comments, authored independently by Ermisch, Martin, and Wu (EMW), appear in this issue of Demography. In this response we argue that the analysis and evidence of our 2006 paper have withstood the scrutiny of EMW. In particular, we find that a substantial part of the rising share of nonmarital births since 1970 is due to a selection effect associated with marriage. This same selection effect also explains how birth rates could rise in both groups, even though their combined birth rate did not. In sum, though we appreciate the opportunity to expand on several key aspects of our 2006 article, we see no reason to substantially revise any of our major conclusions based on the EMW comments.
Fleeing the storm(s): an examination of evacuation behavior during florida’s 2004 hurricane season
Authors: Smith Stanley K. , McCarty Chris
Published: February 2009

The 2004 hurricane season was the worst in Florida’s history, with four hurricanes causing at least 47 deaths and some $45 billion in damages. To collect information on the demographic impact of those hurricanes, we surveyed households throughout the state and in the local areas that sustained the greatest damage. We estimate that one-quarter of Florida’s population evacuated prior to at least one hurricane; in some areas, well over one-half of the residents evacuated at least once, and many evacuated several times. Most evacuees stayed with family or friends and were away from home for only a few days. Using logistic regression analysis, we found that the strength of the hurricane and the vulnerability of the housing unit had the greatest impact on evacuation behavior; additionally, several demographic variables had significant effects on the probability of evacuating and the choice of evacuation lodging (family/friends, public shelters, or hotels/motels). With continued population growth in coastal areas and the apparent increase in hurricane activity caused by global warming, threats posed by hurricanes are rising in the United States and throughout the world. We believe the present study will help government officials plan more effectively for future hurricane evacuations.
Height and the normal distribution: evidence from italian military data
Authors: A’hearn Brian , Peracchi Franco , Vecchi Giovanni
Published: February 2009

Researchers modeling historical heights have typically relied on the restrictive assumption of a normal distribution, only the mean of which is affected by age, income, nutrition, disease, and similar influences. To avoid these restrictive assumptions, we develop a new semiparametric approach in which covariates are allowed to affect the entire distribution without imposing any parametric shape. We apply our method to a new database of height distributions for Italian provinces, drawn from conscription records, of unprecedented length and geographical disaggregation. Our method allows us to standardize distributions to a single age and calculate moments of the distribution that are comparable through time. Our method also allows us to generate counterfactual distributions for a range of ages, from which we derive age-height profiles. These profiles reveal how the adolescent growth spurt (AGS) distorts the distribution of stature, and they document the earlier and earlier onset of the AGS as living conditions improved over the second half of the nineteenth century. Our new estimates of provincial mean height also reveal a previously unnoticed “regime switch” from regional convergence to divergence in this period.
Beyond Economics: Using Social Class Life-Based Literary Narratives with Pre-Service and Practicing Social Studies and English Teachers
Authors: Parker Bruce , Howard Adam
Published: February 2009

In this article, we propose that one way of engaging pre-service and practicing high school Social Studies and English teachers in critical conversations about social class is through the use of life-based literary narratives. By expanding upon Phillion and He's (2004) work around the pedagogical and curricular potential of using life-based literary narratives in multicultural education courses with pre-service teachers, we explore the possibilities of their approach for developing critical understandings of social class among pre-service and practicing Social Studies and English teachers in undergraduate multi-cultural education courses and professional development book groups. Effective use of life-based literary narratives shows more potential for moving practicing and pre-service teachers toward an understanding of the complexities of social class than traditional approaches.
Opening Up Classroom Space: Student voice, Autobiography, & the Curriculum
Authors: Bernhardt Philip
Published: February 2009

Incorporating autobiography into the classroom has the potential to facilitate reflective and interpretative practices, through which self-understanding and transformative learning may emerge. Bridging theory, practice, and the personal, this paper explores how autobiographical narratives were incorporated into a 9 th grade social studies class to create a curricular space which values and embraces student voice, encourages a ethic of care and understanding between students, and embodies both the lived and living experiences. Through this experience students were able to explore their personal relationship to history, assimilate and accommodate new ideas and experiences, and engage in meaningful dialogue about values, beliefs, and perspectives.
This is My Crossroads
Authors: Lastica Joelle R.
Published: February 2009

In her book Borderlands/La frontera: The New Mestiza, Gloria Anzaldúa writes of a "Borderlands," which she describes as "a vague and undetermined place created by the emotional residue of an unnatural boundary....a constant state of transition" (1999, p. 25). In this paper, I explore my own borderlands, between the spaces of my classroom as a former high school chemistry teacher and my present world of graduate education in curriculum and instruction. In the three years since I left my classroom, I have had the opportunity to reflect deeply upon the multiple roles I have had as a teacher—with my students, my colleagues, and the curriculum. How did I negotiate each of these roles in my daily routine? How do I think differently about those roles now, as a graduate student in Education? In this paper, I explore the possibility that this idea of the "space between" is a worthy endeavor, and I wonder if there could be some value in the time-space continuum between classroom teacher and educational theorist. I look to postcolonialist theory to help me traverse my own border crossing from a classroom teacher to education graduate student. In this journey, I explore such concepts as hybridity, in-betweenness, and fluidity to suggest that by valuing the complexities and multiplicities of these in-between spaces, one can partake in everything both spaces offer to authentically embody transformative learning. Through this inquiry into currere, I become more self-aware and work through my intellectual and emotional struggles in my experience of both loss and gain in this borderlands. And finally, I conclude this curriculum inquiry by proposing a different conceptualization of curriculum.
The Limits of "Their Laws": Ancient Rabbinic Controversies about Jewishness (and Non-Jewishness)
Authors: Berkowitz Beth A.
Published: February 2009

Neutralization is a productive way to think about how some early rabbis attempted to build and to bound Jewish identity. A neutralization strategy of the kind Moshe Halbertal has associated with Mishnah Avodah Zarah can be found in a passage from the Sifra (a third-century rabbinic legal compilation) that interprets Leviticus 18:3's injunction against following "their laws." The logic of neutralization for the Sifra is that legal significance is denied to popular, shared practice and restricted to the traditions passed on by a male elite. This reading of the Sifra draws from Daniel Boyarin's argument in Border Lines that early rabbis and Christians created new orthodoxies grounded in a notion of apostolic transmission. The Sifra passage creates a "perverse parallel" to rabbinic orthodoxy and, in so doing, tries to naturalize it. The Sifra's emphasis on gay marriage as the substance of gentile transmission points to the significance of gender and sexual identity for the creation of rabbinic orthodoxy. This neutralization strategy can be contrasted with the construction of Jewish/gentile difference found in a section of material from the Yishma'el school inserted into the Sifra, where rabbinic voices imply that it may be impossible to neutralize pagan practice. This inserted text represents an "anti-neutralization" strategy in which potency is recognized in a wide array of elite and popular habits. This analysis of the Sifra and its inserted materials contributes to an expanding conversation about early rabbis' strategies for negotiating Jewish identity within the Roman imperial context.
European External Quality Control Study on the Competence of Laboratories to Recognize Rare Sequence Variants Resulting in Unusual Genotyping Results
Authors: Márki-Zay János , Klein Christoph L , Gancberg David , Schimmel Heinz G , Dux László
Published: February 2009

Background: Depending on the method used, rare sequence variants adjacent to the single nucleotide polymorphism (SNP) of interest may cause unusual or erroneous genotyping results. Because such rare variants are known for many genes commonly tested in diagnostic laboratories, we organized a proficiency study to assess their influence on the accuracy of reported laboratory results.

Methods: Four external quality control materials were processed and sent to 283 laboratories through 3 EQA organizers for analysis of the prothrombin 20210G>A mutation. Two of these quality control materials contained sequence variants introduced by site-directed mutagenesis.

Results: One hundred eighty-nine laboratories participated in the study. When samples gave a usual result with the method applied, the error rate was 5.1%. Detailed analysis showed that more than 70% of the failures were reported from only 9 laboratories. Allele-specific amplification-based PCR had a much higher error rate than other methods (18.3% vs 2.9%). The variants 20209C>T and [20175T>G; 20179_20180delAC] resulted in unusual genotyping results in 67 and 85 laboratories, respectively. Eighty-three (54.6%) of these unusual results were not recognized, 32 (21.1%) were attributed to technical issues, and only 37 (24.3%) were recognized as another sequence variant.

Conclusions: Our findings revealed that some of the participating laboratories were not able to recognize and correctly interpret unusual genotyping results caused by rare SNPs. Our study indicates that the majority of the failures could be avoided by improved training and careful selection and validation of the methods applied.
Analytical Ancestry: “Firsts” in Fluorescent Labeling of Nucleosides, Nucleotides, and Nucleic Acids
Authors: Kricka Larry J , Fortina Paolo
Published: February 2009

Background: The inherent fluorescent properties of nucleosides, nucleotides, and nucleic acids are limited, and thus the need has arisen for fluorescent labeling of these molecules for a variety of analytical applications.

Content: This review traces the analytical ancestry of fluorescent labeling of nucleosides, nucleotides, and nucleic acids, with an emphasis on the first to publish or patent. The scope of labeling includes (a) direct labeling by covalent labeling of nucleic acids with a fluorescent label or noncovalent binding or intercalation of a fluorescent dye to nucleic acids and (b) indirect labeling via covalent attachment of a secondary label to a nucleic acid, and then binding this to a fluorescently labeled ligand binder. An alternative indirect strategy involves binding of a nucleic acid to a nucleic acid binder molecule (e.g., antibody, antibiotic, histone, antibody, nuclease) that is labeled with a fluorophore. Fluorescent labels for nucleic acids include organic fluorescent dyes, metal chelates, carbon nanotubes, quantum dots, gold particles, and fluorescent minerals.

Summary: Fluorescently labeled nucleosides, nucleotides, and nucleic acids are important types of reagents for biological assay methods and underpin current methods of chromosome analysis, gel staining, DNA sequencing and quantitative PCR. Although these methods use predominantly organic fluorophores, new types of particulate fluorophores in the form of nanoparticles, nanorods, and nanotubes may provide the basis of a new generation of fluorescent labels and nucleic acid detection methods.
A Multiplex Assay for Detecting Genetic Variations in CYP2C9, VKORC1, and GGCX Involved in Warfarin Metabolism
Authors: Rai Alex J , Udar Nitin , Saad Rana , Fleisher Martin
Published: February 2009

Background: Patients differ in responses to warfarin, which is commonly prescribed to treat thromboembolic events. Genetic variations in the cytochrome P450, family 2, subfamily C, polypeptide 9 (CYP2C9), vitamin K epoxide reductase complex, subunit 1 (VKORC1), and gamma-glutamyl carboxylase (GGCX) genes have been shown to contribute to impaired metabolism of warfarin.

Methods: We designed a custom multiplex single-nucleotide polymorphism (SNP) panel to interrogate the CYP2C9 *2, *3, VKORC1 (–1639G→A), and GGCX (1181T→G) alleles simultaneously in a single sample by use of single-base extension and capillary electrophoresis after genomic DNA extraction and PCR amplification.

Results: Our assay successfully detected various genotypes from known controls and 24 unknown samples. It was found to be 100% concordant with sequencing results.

Conclusions: Our multiplexed SNP panel can be successfully used in genotyping of patient blood samples. Results can be combined with other clinical parameters in an algorithm for warfarin dosing. These data provide a proof-in-principle of multiplexed SNP analysis using rapid single-base extension and capillary electrophoresis, and warrant additional validation using a larger cohort of patient samples.
Interindividual and Interethnic Variation in Genomewide Gene Expression: Insights into the Biological Variation of Gene Expression and Clinical Implications
Authors: Fan Harris P Y , Di Liao Chen , Fu Brenda Yan , Lam Linda C W , Tang Nelson L S
Published: February 2009

Background: Analysis of gene expression in peripheral blood samples is increasingly being applied in biomarker studies of disease diagnosis and prognosis. Although knowledge of interindividual and interethnic variation in gene expression is required to set ethnicity-specific reference intervals and to select reference genes and preferred markers from a list of candidate genes, few studies have attempted to characterize such biological variation on a genomewide scale.

Methods: The genomewide expression profiles of 11 355 transcripts expressed among 210 multiethnic individuals of the HapMap project were obtained and analyzed; 4 replicates were included for each sample. The total biological CV in gene expression (CVb) was partitioned into interindividual (CVg), inter-ethnic group (CVe), and residual components by random-effects mixed models.

Results: CVg was the major component of CVb, and the differences among transcripts were large (up to 38%). Distinct groups of genes were characterized by CV values and expression levels. Of the genes with lowest biological variation (CVb < 1.5%), 35 genes were highly expressed, whereas 32 had intermediate or low expression. Although CVg was almost always greater than CVe, we identified 10 genes in which ethnic variation predominated (range, 8%–18%). On the other hand, 17 annotated genes were highly variable with CVg values ranging between 15% and 38%.

Conclusions: Genomewide analysis of gene expression variation demonstrated biological differences among transcripts. Transcripts with the least biological variation are better candidates for reference genes, whereas those with low interindividual variation may be good disease markers. The presence of interethnic variation suggests that ethnicity-specific reference intervals may be necessary.
Overinterpretation of Clinical Applicability in Molecular Diagnostic Research
Authors: Lumbreras Blanca , Parker Lucy A , Porta Miquel , Pollán Marina , Ioannidis John P A , Hernández-Aguado Ildefonso
Published: February 2009

Background: We evaluated whether articles on molecular diagnostic tests interpret appropriately the clinical applicability of their results.

Methods: We selected original-research articles published in 2006 that addressed the diagnostic value of a molecular test. We defined overinterpretation of clinical applicability by means of prespecified rules that evaluated study design, conclusions regarding applicability, presence of statements suggesting the need for further clinical evaluation of the test, and diagnostic accuracy. Two reviewers independently evaluated the articles; consensus was reached after discussion and arbitration by a third reviewer.

Results: Of 108 articles included in the study, 82 (76%) used a design that used healthy controls or alternative-diagnosis controls, only 15 (11%) addressed a clinically relevant population similar to that in which the test might be applied in practice, 104 articles (96%) made definitely favorable or promising statements regarding clinical applicability, and 61 (56%) of the articles apparently overinterpreted the clinical applicability of their findings. Articles published in journals with higher impact factors were more likely to overinterpret their results than those with lower impact factors (adjusted odds ratio, 1.71 per impact factor quartile; 95% CI, 1.09–2.69; P = 0.020). Overinterpretation was more common when authors were based in laboratories than in clinical settings (adjusted odds ratio, 18.7; 95% CI, 1.41–249; P = 0.036).

Conclusions: Although expectations are high for new diagnostic tests based on molecular techniques, the majority of published research has involved preclinical phases of research. Overinterpretation of the clinical applicability of findings for new molecular diagnostic tests is common.
Increased plasminogen activator inhibitor-1, decreased tissue factor pathway inhibitor, and unchanged thrombin-activatable fibrinolysis inhibitor levels in patients with primary hyperparathyroidism
Authors: Erem Cihangir , Kocak Mustafa , Nuhoglu İrfan , Yilmaz Mustafa , Ucuncu Ozge
Published: February 2009

Background and objectives

Primary hyperparathyroidism (PHPT) is associated with increased cardiovascular mortality and morbidity. Little is known about hemostatic features of patients with PHPT. To our knowledge, plasma tissue factor pathway inhibitor (TFPI) and thrombin-activatable fibrinolysis inhibitor (TAFI) levels in these patints have not been investigated. Therefore, the main purpose of this study was to evaluate the markers of endogenous coagulation/fibrinolysis, including TFPI and TAFI, and to investigate the relationships between serum calcium and PTH and these hemostatic parameters in patients with PHPT.

Design and methods

Twenty-four patients with PHPT and 20 age-, sex-, and-weight-matched healthy controls were included in the study. Tissue plasminogen activator (t-PA), tissue plasminogen activator inhibitor-1 (PAI-1), TFPI, and TAFI were measured. The relationships between serum calcium, phosphorus, and PTH and these hemostatic parameters were examinated.

Results

Compared with the control subjects, t-PA, PAI-1, and PAI-1/t-PA ratios were significantly increased in patients with PHPT (P<0.0001), whereas TFPI levels were significantly decreased (P<0.0001). Plasma TAFI Ag levels did not significantly change in patients with PHPT compared with the controls. In patients with PHPT, serum phosphorus was negatively correlated with plasma PAI-1 Ag levels and PAI-1/t-PA ratio (r: −0.453,P<0.05;r: −0.580,P<0.01 respectively). There was a positive correlation between Cl/P ratio and plasma PAI-1 levels and PAI-1/t-PA ratio (r: 0.434,P<0.05;r: 0.528,P<0.05 respectively). iPTH was positively correlated with plasma PAI-1/t-PA ratio (r: 0.429,P<0.05).

Interpretation and conclusions

In conclusion, we found some important differences in the hemostatic parameters between the patients with PHPT and healthy controls. Increased PAI-1, PAI-1/t-PA ratios and decreased TFPI levels in these patients represent a potential hypercoagulable and hypofibrinolytic state, which might augment the risk for atherosclerotic and atherothrombotic complications. This condition may contribute to the excess mortality due to cardiovascular disease seen in patients with PHPT.