bluuebunny/crossref_metadata_2025 huggingface dataset:
Children's Ability to Demonstrate Music Concept Discriminations in Listening and Singing
Authors: Sims Wendy L.
Published: June 2006

This study examined the relationship of grade level to children s ability to make musical discriminations when elements are presented simultaneously. Children enrolled in first through fifth grade were subjects for this study (N = 669). A listening test designed to assess the subjects' ability to discriminate and label contrasting musical characteristics related to tempo and articulation within single- and double-discrimination contexts was administered following a brief instructional period. A smaller sample of children (n = 60) then completed a singing task in which they were required to perform a familiar song to demonstrate varied combinations of the two musical elements. Results of the listening test indicated significant main effects for grade, characteristic, and type of discrimination, with significant interactions. Subjects were significantly more successful with single discriminations than double discriminations, and mean scores for tempo were significantly higher than for articulation, particularly under the double discrimination condition. When singing subjects demonstrated contrasting tempi and smooth articulation but had difficulty with choppy articulation, both in single-element as well as combined-element examples.
The Effect of Accuracy of Instruction, Teacher Delivery, and Student Attentiveness on Musicians' Evaluation of Teacher Effectiveness
Authors: Madsen Katia
Published: June 2006

This study is an examination of whether accuracy and delivery of teacher instruction and student attentiveness would affect evaluative perceptions of teacher effectiveness. Participants were 168 musicians and were grouped according to experience level: (a) Grades 6–8, (b) Grades 9–12, (c) undergraduate, and (d) experienced teacher. Participants viewed and evaluated a videotape of eight teaching segments for teaching effectiveness. A two-way ANOVA with repeated measures indicated significant differences due to experience level and teaching segments. Results indicated that the secondary students rated a teacher giving inaccurate instruction relatively high when the teacher demonstrated high delivery and the class was attentive. Analysis of the descriptive data suggested that the four groups attended to the delivery of the teacher more than any other variable. Experienced teachers attended to accuracy of instruction more than did any other group, and middle schoolers attended to student attentiveness, or perceived classroom management skills of the teacher, more than did any other group.
Transforming Music Teaching via Technology: The Role of Professional Development
Authors: Bauer William I. , Reese Sam , McAllister Peter A.
Published: June 2006

The purpose of this study was to determine if 1-week technology workshops can be an effective means for the professional development of music teachers in using technology for instruction. The results indicate that three indicators of effectiveness—teacher knowledge, teacher comfort, and frequency of teacher use—can he significantly improved in these settings. Participants ( N = 63) were music teachers enrolled in summer music technology workshops. At the beginning of the workshops, participants completed a questionnaire designed to provide demographic information and assess their knowledge of music technology, degree of comfort with music technology, and the frequency with which they used music technology in their teaching. Following an intensive weeklong workshop dealing with strategies for teaching music to K—12 students using music technology, participants completed a second questionnaire that was parallel to the first. Participants completed another similar questionnaire 9 to 10 months after the workshop. Significant differences were found between the pre-and. postworkshop questionnaires, between the preworkshop and follow-up questionnaires, and, between the postworkshop and follow-up questionnaires in all three areas. There was also a moderate correlation ( r = .43, p = .00) between participants' frequency of technological use and the degree to which they reported their access to technological resources.
Effect of Tempo on Music Preferences of Children in Elementary and Middle School
Authors: Montgomery Amanda P.
Published: June 2006

This study was designed to examine the effect of tempo on preference responses of kindergarten to Grade 8 children. Listener age and gender were additional variables under consideration. In total, 996 subjects indicated preference opinions on pictographic Likert written response forms while listening to 15 excerpts of orchestral music from early Romantic opera. Two moderate and three fast musical examples were given the highest mean ratings. Spearman rank correlation indicated a positive significant relationship between tempo and preference (p < .01). Friedman analyses of variance revealed significant differences in mean preference ratings for music of differing tempos within Grades 3-8 (p < .01). Listener age was also indicated as a strong influence on overall preference ratings, with youngest children generally giving highest ratings. Results provide further support for the role of tempo and listener age in musical preference.
The Status of Undergraduate String Teacher Education in American Colleges and Universities
Authors: Smith Camille M.
Published: June 2006

This study is an examination of undergraduate string teacher education in American colleges and universities. A random sample of 180 NASM-accredited teacher training institutions was selected from the six MENC divisions, each of which represents a large geographical region of the United States. Specific research questions posed were (a) What types of string education courses are required for undergraduate music education majors? (b) What content is included in these courses? (c) How does string teacher education vary in different regions of the country? and (d) How well are undergraduate students being prepared to function as future public school string teachers? Statistically significant findings were obtained for the different regions of the country, with institutions in the North Central Division requiring the greatest number of separate string techniques and string methods courses for all music education majors. Institutions in this region also require the most contact hours per week per course, have the largest number of string education specialists teaching the courses, and taken as a group, do a significantly better job of preparing students to meet specific string teacher competencies than do institutions in other regions of the country.
The Effects of Knowledge of Instructional Goals on Observations of Teaching and Learning
Authors: Henninger Jacqueline C.
Published: June 2006

The purpose of this study was to determine whether the perceptions of observers who are informed of the proximal goals of instruction differ from those who are not so informed. Music education majors (N = 120) viewed one of three randomly assigned stimulus tapes. Each stimulus tape contained seven teaching episodes. Subjects wrote brief statements about their observations and rated the quality of the teaching while they watched each of the episodes. Half the subjects (n = 60) were informed of the instructional goals addressed in each of the episodes; the remaining subjects (n = 60) were not so informed. Observers' written statements were classified according to topic, depth, and evaluative quality. Subjects not informed of the instructional goals wrote significantly more teacher-directed, inferential, and positive statements than did the subjects who were informed of the instructional goals. In both observation conditions, 80% of the written observations pertained to the teachers, and only 14% pertained to the students. Subjects' mean ratings of teaching quality did not differ significantly between the observation conditions.
Instrumentalists' Assessment of Solo Performances with Compact Disc, Piano, or No Accompaniment
Authors: Brittin Ruth V.
Published: June 2006

Middle school and high school instrumentalists listened to 12 instrumental performances: four with no accompaniment, four with piano accompaniment, and four with compact disc accompaniment. Listeners (N = 188) judged the soloist's performance quality and indicated the performance's best feature and aspect needing most improvement. Listeners also rated their preference for each accompaniment. Materials were taken from popular beginning band method books. Results showed that accompaniment condition significantly affected performance quality ratings, with CD accompaniments rated highest and piano accompaniments lowest. Significant interactions revealed that younger students were swayed most by the accompaniment condition; certain popular music styles appeared most influential. There was a significant but modest relationship between greater preference for the accompaniment style and higher performance quality ratings. For preference, girls and boys responded significantly differently to the accompaniment styles. Overall, students consistently assigned the best feature and aspect needing most practice across accompaniment conditions.
Music Courses for Elementary Education Majors: An Investigation of Course Content and Purpose
Authors: Gauthier Delores , McCrary Jan
Published: June 2006

We prepared a survey instrument to determine the purpose, format, and content of courses available to undergraduate elementary education majors at institutions accredited by the National Association of Schools of Music (NASM). We examined the types of music courses offered to elementary classroom teachers, the content of the courses, the instructor's purpose for each course, and factors that influenced curricular decisions. We mailed the questionnaire to 530 schools listed in the NASM directory. An initial and two follow-up mailings yielded 316 responses (60%). The Kruskal-Wallis test for independent samples revealed statistical significance beyond the .01 level for the fundamentals course, F (2, 27) = 17.17. The study's results show there was stronger agreement among respondents who taught fundamentals courses than among respondents who taught methods or combined courses.
The Development of an Instrument to Grade the Difficulty of Vocal Solo Repertoire
Authors: Ralston Janette
Published: June 2006

The purpose of this study was to design a valid and reliable instrument—the Ralston Repertoire Difficulty Index (RRDI)—to measure the difficulty of solo vocal repertoire. Another aspect of this study was to determine the RRDI's ability to be used by voice teachers of all experience levels and to discriminate songs' difficulty into levels. Seven criteria—range, tessitura, rhythm, phrases, melodic line, harmonic foundations, and pronunciation—were incorporated in the instrument. The RRDI was tested by 34 postsecondary voice teachers. Results of the study showed that each criterion was significantly related to one overall rating established by Boytim (1982). The results also indicated high validity and reliability, and analyses revealed that the RRDI discriminated across difficulty levels and was used similarly by teachers of all experience levels.
Field Dependence-Independence and College Nonmusic Majors' Description and Identification of Music Excerpts
Authors: Ellis Mark C.
Published: June 2006

In this investigation of the effects of field dependence-independence (FDI), general mental ability, previous music experience, and gender on music listening, 148 students enrolled in a college introductory music class recorded observations about eight music excerpts. After 1 week and again after 2 weeks, subjects used their observations to identify the excerpts. A series of multiple-regression analyses was used to examine the unique contributions of the four subject variable sets to the explanation of variance in excerpt identification (EI) scores. The regression of all sets accounted for 30.9% of the variance in EI scores. FDI, as measured by the Group Embedded Figures Test (GEFT), uniquely accounted for 9.1% of the variance in EI scores. General mental ability, as measured by the ACT, uniquely accounted for 6.3% of the variance in EI scores. Experience and gender each explained less than 1 % of the unique variance.
University Music Educators' Perceptions of the Importance of Public-School-Related Off-Campus Activities
Authors: Hamann Donald L. , Lawrence Joy E.
Published: June 2006

The purpose of this study was to determine: (a) whether any significant differences existed within university music educators' responses to each of 16 activities, identified previously to be “recognized” off campus activities, in the categories of frequency of performance, effectiveness in helping keep them up-to-date with public school settings, and perceived importance of each activity in tenure/promotion decisions, (b) whether any significant differences existed between university music educators' responses in these evaluation categories (frequency, effectiveness, and importance) according to the perceived role and expectation of the different institutions, (c) how often university music educators performed each of 16 activities, (d) how effective university music educators thought each of the 16 activities would be in keeping them up-to-date with public school settings, (e) the university music educators' perception of the importance of each activity in tenure/promotion decisions, and (f) whether university music educators' responses to the perceived effectiveness of the 16 activities differed from previously obtained responses of public school music educators. From analyses, it was found that significant differences existed within and between university music educators' responses by category, between university music educators' responses by institutional role and expectation, and between effectiveness rankings of public school and university music educators.
String Teachers' Diagnostic Skills and Their Students' Performance Competencies
Authors: Gillespie Robert
Published: June 2006

In this study, I investigated the relationship between the diagnostic skills of string teachers and the performance competencies of their students in simple detaché violin bowing. Twenty-two string teachers took a video violin-bowing diagnostic skills test. Three students of each teacher were randomly selected and their violin bowing skills were rated. Data revealed no significant correlation between the diagnostic test scores of the teachers and the performance ratings of their students. In addition, teachers rated the influence of 22 different factors on the development of the performance competencies of their students.
Effects of Instruction and Task Format on Preschool Children's Music Concept Discrimination
Authors: Sims Wendy L.
Published: June 2006

Two studies were completed to investigate young children's ability to identify single and combined musical elements in response to listening, movement, and singing activities. Study 1 was an examination of the effects of short-term instruction on preschool children's ability to apply decentration to musical tasks. Subjects ( N = 30) were divided into (a) an experimental group, which participated in four small-group instruction sessions designed to teach the discriminations fast/slow and smooth/choppy as well as these elements' four possible combinations and (b) a posttest-only control group. Results indicated that instruction was significantly related to subjects' ability to identify and label musical characteristics, and that subjects were significantly more accurate with single versus double discrimination responses. Study 2 was designed to replicate aspects of the previous study, with the addition of singing as a response mode and age as a variable. All the preschool-age subjects ( N = 42) received the instruction component of Study 1. Results of the listening test again indicated that subjects were significantly more successful with the single discrimination task and that older children scored significantly higher than younger children. The subjects were better able to label simultaneous musical characteristics in their own singing than in recorded listening examples. Conclusions drawn, based on both studies, include: (1) preschool-age children can easily learn to make and label single discriminations; (2) most young children may not be ready for music listening tasks requiring attention to more than one element at a time; (3) children's ability to make discriminations based on their own performance may develop earlier than their ability to make discriminations in listening situations; and (4) initial indications of discrimination may be demonstrated through singing in simultaneous imitation with a model.
Listeners' Response to Music as a Function of Personality Type
Authors: Lewis Barbara E.
Published: June 2006

The purpose of this study was to examine listener response to music as a function of the personality variables measured by the Myers-Briggs Type Indicator (MBTI). Undergraduate nonmusic majors ( N = 328) who were enrolled in music appreciation courses indicated characteristic responses to music on the Music Listener Response Scale (MLRS) (after Hedden, 1973). The MLRS contained statements that focused on responses to music that were classified as associative, cognitive, physical involvement, or enjoyment. Subjects responded to statements on a scale that ranged from “all of the time” to “none of the time.” Pearson product-moment correlations were determined between the MIMS and the Myers-Briggs variables. Significant ( p < .001) correlations were found between the MLRS and sensing-intuition for the entire sample and subgroups of male and female subjects. A significant ( p < .01) correlation was found between judgment-perception and the MLRS for female subjects. MBTI scores were used to identify 16 subgroups according to the 16 possible combinations among the variables. A one-way analysis of variance (ANOVA) was performed for the MLRS composite with Myers-Briggs type as the independent variable having 16 levels. The overall F test was significant [ F(15, 312) =3.06, p < .05] and accounted for 13% of the variance in the MLRS.
Talking about Music: Interviews with Disabled and Nondisabled Children
Authors: Jellison Judith A. , Flowers Patricia J.
Published: June 2006

The purpose of this study was to describe, categorize, and compare data concerning music preferences, experiences, and skills obtained from interviews with 228 students labeled “disabled” ( n = 73) or “nondisabled” ( n = 155). A structured assessment interview was used by university student proctors to collect information from the students in four age-groups. Students identified by their respective schools as eligible for special education services constituted the group labeled “disabled.” Questions developed for the interview focused on listening preferences and experiences, musical instrument preferences and performance, and singing and clapping (steady beat) performance. Following procedures consistent with naturalistic inquiry, audiotapes and transcriptions of the interviews were content-analyzed, and categories were developed from the responses. Perhaps the most notable outcome of this study is the similarity of responses between students with disabilities and their nondisabled peers. Results are discussed specific to music curriculum development, the integrated music classroom, and peer/teacher acceptance.
Approaches to Children's Song Acquisition: Immersion and Phrase-by-Phrase
Authors: Klinger Rita , Campbell Patricia Shehan , Goolsby Thomas
Published: June 2006

This study is an examination of the effect of two instructional procedures for teaching songs to children: (a) immersion, in which the teacher presents the song in its entirety repeatedly, always from the beginning of the song to its conclusion, and (b) phrase-by-phrase, a method whereby the teacher fragments and then gradually connects song phrases toward the creation of a meaningful whole. Thirty-nine second-grade children from two classes were taught two traditional children's songs using both methods in a counterbalanced design. Results showed that children taught through the immersion method performed the songs with fewer errors than did those taught through the phrase-by-phrase process. A discussion of children's need for musical and textual continuity (which the immersion process provides) is followed by recommendations for future research.
Causal Beliefs of Public School Students about Success and Failure in Music
Authors: Legette Roy M.
Published: June 2006

Student motivation and achievement in relation to Attribution Theory were examined in this study. Public school students (N = 1,114) were asked to respond to items on Asmus's Music Attribution Orientation Scale, indicating those causes that they attributed most to succeeding or failing in music. Results showed that, collectively, students placed more importance on ability and effort as causal attributions. Gender, school level, and school system were found to have significant effects on student response. Implications for teaching and future research are discussed.
An Examination of the Intonation Tendencies of Wind Instrumentalists Based on Their Performance of Selected Harmonic Musical Intervals
Authors: Karrick Brant
Published: June 2006

This study is an examination of intonation trends of experienced wind instrumentalists with regard to harmonic intervals. Factors of interest were tuning system, location, interval type, direction of deviation from equal temperament, and group. Subjects (N = 16) were experienced wind instrumentalists (8 professionals, 8 advanced students). Subjects recorded a duet, first playing the melody with a synthesized harmony line, and then vice versa. Target intervals were analyzed, converted to cent distance, and compared. Results indicated that deviation was greatest when compared to just tuning and least when compared to equal tempered tuning. For cent deviation from equal temperament, thirds and sixths were performed slightly less in-tune than fourths, fifths, unisons, and octaves. Location affected direction of deviation as subjects played sharp and less in tune when performing below the stimulus. The student group performed less sharp than the professional group when performing below the stimulus and less in tune when performing above.
Spacing, Formation, and Choral Sound: Preferences and Perceptions of Auditors and Choristers
Authors: Daugherty James F.
Published: June 2006

The purpose of this study was to assess preferences of auditors ( N = 160) and choristers ( N = 46) relative to choral sound of an SATB high school choir in two choral formations (block sectional and mixed) and three spacings (close, lateral, and circumambient). Six conditions of a 30-second homophonic choral excerpt were sung and recorded digitally. Auditors listened to 10 pairs of randomly ordered excerpts, expressing preference for most pleasing choral sound. Choristers completed the Singer Evaluation Form. Auditor results indicated consistently significant preference for excerpts sung with spread spacing and no consistent preference for formation per se. Choristers (95.60%) thought spacing influenced their choral sound. Singers consistently and significantly preferred spread spacing and attributed to it improved vocal production and ability to better hear both self and ensemble. Results suggested that choir spacing made a greater contribution to choral sound preferences of both auditors and choristers than did choral formation.
Effect of Teaching Setting and Self-Evaluation on Teacher Intensity Behaviors
Authors: Colwell Cynthia M.
Published: June 2006

The purpose of this study was to examine the effect of teaching setting [peer versus practicum] and self-evaluation tools [Continuous Response Digital Interface (general) versus behavioral checklist (specific)] on the development of teacher intensity behaviors among preservice elementary education majors enrolled in a music methods course. Subjects were divided into four treatment groups and completed a pretest and posttest and four treatment lessons. Analyses indicated that teaching setting and self-evaluation did not have a differential effect on teacher intensity. All subjects made significant gains from pretest to posttest, with differences among lessons. Comparative analyses indicated subjects rated themselves higher than did experts. An attitude survey indicated that subjects who taught children rated the course higher than subjects who taught their peers, whereas subjects who completed general self-evaluations rated the course higher than did subjects who completed specific self-evaluations.
Little Red Songbooks: Songs for the Labor Force of America
Authors: Volk Terese M.
Published: June 2006

Since the early part of the twentieth century, there have been selected colleges in the United States dedicated to the training of future leaders for labor unions. Four of the most prominent are Work Peoples' College, Duluth, Minnesota; Brookwood College, Katonah, New York; Commonwealth College, Mena, Arkansas; and Highlander College, Monteagle, Tennessee. Education at these colleges, including music education, ran counter to the educational establishment of their time. Issues of labor versus management, traditional versus nontraditional education, and structured (formal) curricula versus practical (informal) curricula are all in evidence. All four institutions had songbooks. An examination of archival copies of these songbooks, within the context of the curricula of the schools and the labor movement in the United States, shows that nearly all the songs were parodies set to the folk and popular tunes of the day. These songs provided a means through which to teach union solidarity and labor concepts. Music education at these colleges was generally done on an informal basis. Students developed their skills as lyricists, song leaders, and performers through sing-alongs and the use of music in drama. Nontraditional though this was, the practical music training the students experienced in these labor colleges produced powerful results in their unions.
Predicting Music Appreciation with Past Emotional Responses to Music
Authors: Woody Robert H. , Burns Kimberly J.
Published: June 2006

This study is an exploration of the musical backgrounds and beliefs of nonmusicians and the relationship of these variables to music appreciation factors. Subjects were 533 college students enrolled in 17 sections of courses in Music Appreciation and Music for Classroom Teachers. Subjects completed a questionnaire regarding their musical backgrounds, preferences, and beliefs and then heard and responded to four highly expressive classical music excerpts. Data analyses indicated significant relationships between certain musical background factors and responsiveness to classical music. More specifically, past emotional experience with classical music was a reliable predictor of music appreciation, as measured by appropriate recognition of expression and willingness to listen to classical music on one's own time. Implications are drawn regarding approaches for teaching classical music to nonmusicians, including increased focus on expressive qualities in music listening experiences.
Effects of Melodic Pattern Difficulty and Performance Experience on Ability to Play by Ear
Authors: Delzell Judith K. , Rohwer Debbie A. , Ballard Diane E.
Published: June 2006

The primary purpose of this study was to determine the relative difficulty of playing selected types of melodic patterns by ear. Ancillary purposes were to study the effects of performance experience and instrument family on the ability to play by ear, and to investigate the relationship between tonal aptitude and ability to play by ear. Results indicated that (a) descending patterns are more challenging than ascending; (b) patterns in minor tonality are more difficult to play by ear than are those in major; (c) students tend to continue using a familiar (though incorrect) fingering pattern on the repetition of a melodic pattern in a less familiar key, even when it seems that the students realize it is incorrect; and (d) shifting the last pitch of a pattern is easier than shifting the middle pitch. Results showed there was no difference in the ability to play by ear when considering performance experience, instrument family, or the interaction between performance experience and instrument family. There was a moderate positive relationship between tonal aptitude and ability to play by ear for 7th-grade students in this investigation.
The Effects of Learning Procedure, Tempo, and Performance Condition on Transfer of Rhythm Skills in Instrumental Music
Authors: Pierce Michael A.
Published: June 2006

In this study, I examined the effects of learning procedure and performance tempo on the ability of middle-school-level instrumentalists to perform previously learned rhythmic passages in novel test melodies. Sixty-four advanced- and intermediate-level middle school band students practiced four three-measure rhythmic passages, using one of four learning procedures for each rhythmic passage, until achieving a specified performance criterion, and subsequently performed lest melodies that included the same rhythms. The learning procedures represented verbal and manual techniques that are common in rhythm instruction in instrumental classes and that had been used regularly in daily lessons in which all subjects participated. Performances were evaluated on the basis of tempo accuracy, rhythm accuracy, and pitch accuracy. Results indicate no significant multivariate effect attributable to learning procedure; however, significant differences were found among performance tempi, p < .02. Subjects' tempo accuracy was adversely affected by differences between the tempo at which specific passages were originally learned and the tempi at which they were subsequently performed.
Faculty Interjudge Reliability of Music Performance Evaluation
Authors: Bergee Martin J.
Published: June 2006

Assessment of music performance in authentic contexts remains an underinvestigated area of research. This study is an examination of one such context, the inter-judge reliability of faculty evaluation of end-of-semester applied music performances. Brass (n = 4), percussion (n = 2), woodwind (n = 5), voice (n = 5), piano (n = 3), and string (n = 5) instructors evaluating a recent semester's applied music juries at a large university participated in the study. Each evaluator completed a criterion-specific rating scale for each performer and assigned each performance a global letter grade not shared with other evaluators or with the performer. Interjudge reliability was determined for each group's rating scale total scores, subscale scores, and the letter-grade assessment. All possible permutations of two, three, and four were examined for interjudge reliability, and averaged correlations, standard deviations, and ranges were determined. Full-panel interjudge reliability was consistently good regardless of panel size. All total score reliability coefficients were statistically significant, as were all coefficients for the global letter-grade assessment. All subscale reliabilities for all groups except Percussion (which, with an n of 2, had a stringent significance criterion) were statistically significant, with the exception of the Suitability subscale in Voice. For larger panels (ns of 4 and 5), rating scale total score reliability was consistently but not greatly higher than reliability for the letter-grade assessment. There was no decrease of average reliability as group size incrementally decreased. Permutations of two and three evaluators, however, tended on average to exhibit more variability, greater range, and less uniformity than did groups of four and five. No differences in reliability were noted among levels of experience or between teaching assistants and faculty members. Use of a minimum of five adjudicators for performance evaluation in this context was recommended.
Effects of Modeling and Tempo Patterns as Practice Techniques on the Performance of High School Instrumentalists
Authors: Henley Paul T.
Published: June 2006

The purpose of this study was to examine the effect of modeling conditions and tempo patterns on the performance of high school instrumentalists. The independent variables of this study were (a) model versus no model and (b) steady increase of tempo versus performance speed tempo versus alternating (slower and faster) tempos. Subjects (N = 60) were high school wind instrumentalists from the American Midwest and South. Subjects sight-read an étude and then practiced the same étude six times using one of six practice conditions that combined the two independent variables. Subjects then performed a posttest on the same étude. Dependent measures were pretest-posttest gain score comparisons (as percentages) of correct pitches and rhythms as well as overall percentages of tempo gains. Results demonstrated the with-model condition to be superior to the no-model condition in rhythm percentage gain and tempo percentage gain. Tempo patterns had no significant effect on results.
Family composition and menarcheal age: Anti‐inbreeding strategies
Authors: Matchock Robert L. , Susman Elizabeth J.
Published: June 2006

Family composition (e.g., the absence of a father) is associated with pubertal timing in women, although the socioendocrinology of the human primate is poorly understood. To better understand social influences on sexual maturation, retrospective data were collected on menarcheal age and family composition from a sample of approximately 1,938 participants from a college population. Absence of a biological father, the presence of half‐ and step‐brothers, and living in an urban environment were associated with earlier menarche. The presence of sisters in the household while growing up, especially older sisters, was associated with delayed menarche. Menarcheal age was not affected by number of brothers in the household, nor was there an effect of birth order. Body weight and race were also associated with menarche. The present findings advance the literature as they are suggestive of putative human pheromones that modulate sexual maturation to promote gene survival and prevent inbreeding, as occurs in rodents and nonhuman primates. Am. J. Hum. Biol. 18:481–491, 2006. © 2006 Wiley‐Liss, Inc.
Genetic structure of Algerian populations
Authors: Lefevre‐Witier Philippe , Aireche Hadi , Benabadji Mohamed , Darlu Pierre , Melvin Kristin , Sevin Andre , Crawford Michael H.
Published: June 2006

Blood samples were collected in Algeria from 4,444 army recruits and tested for 10 genetic polymorphic systems. These samples were collected from territorial Wilayas (administrative units of Algeria) from which the young soldiers had originated. Based on similar geography and economic and political history, these Wilayas were clustered into 10 regions. These regions, not part of the governmental administrative units, were characterized by allelic frequencies, and analyzed using R‐matrix principal components, Wright's FST, spatial autocorrelation, and Mantel tests. Hierarchical relationships between the culturally defined regions were examined using two different analytical methods of phylogenetic tree constructions: neighbor‐joining, and unweighted pair group average arithmetic (UPGMA). These results indicated the predominance of genetic homogeneity due to the gene flow between regions, but with some migration emanating from sub‐Saharan Africa and Mediterranean Europe. Wright's FST value of 0.0063, based on 16 alleles, suggested a relatively small genetic microdifferentiation of the regions. In Algeria, gene flow apparently swamped most of the effects of stochastic processes and disrupted the relationship between geography and genetics, as characterized by the isolation‐by‐distance model. Some genetic differences and similarities were observed between regions or clusters of regions. The resulting genetic structure of the Algerian populations is best explained by a combination of gene flow, ecology, and history. Am. J. Hum. Biol. 18:492–501, 2006. © 2006 Wiley‐Liss, Inc.
Asian and non‐Asian origins of Mon‐Khmer‐ and Mundari‐speaking Austro‐Asiatic populations of India
Authors: Kumar Vikrant , Langsiteh Banrida T. , Biswas Silpak , Babu J. Pradeep , Rao T. Nageswara , Thangaraj K. , Reddy A.G. , Singh L. , Reddy B. Mohan
Published: June 2006

In the present study, we analyzed 1,686 samples from 31 tribal populations of India for the mitochondrial DNA 9‐base‐pair deletion/insertion polymorphism, and characterized them based on the relevant mitochondrial DNA coding‐region single nucleotide polymorphisms and hypervariable region I motifs, to test the genetic origins of the ethnically and linguistically heterogeneous Austro‐Asiatic tribes of India. A comparative analysis of our results with the existing data suggests multiple origins of Austro‐Asiatic tribes in India, and particularly the Asian and non‐Asian origins of the Mon‐Khmer and the Mundari populations. We also identified a novel subclade of haplogroup B in the Mon‐Khmer Khasi tribes that distinguishes them from the Nicobarese, indicating two different waves of migration of the Mon‐Khmer tribes in India. Am. J. Hum. Biol. 18:461–469, 2006. © 2006 Wiley‐Liss, Inc.
p.Q223R leptin receptor polymorphism associated with obesity in Brazilian multiethnic subjects
Authors: Duarte Stenio Fernando Pimentel , Francischetti Emílio Antonio , Genelhu‐Abreu Virgínia , Barroso Sergio Girão , Braga José Uéleres , Cabello Pedro Hernan , Pimentel Márcia Mattos Gonçalves
Published: June 2006

Several genes play a major role in obese phenotypes, and studies suggest that genetic variations among individuals, as well as their lifestyles, may bring about different body compositions. Among these genes, LEP, which codifies leptin, and the LEPR gene encoding its receptor were extensively studied for variants that could explain the obese phenotype. The LEPR p.Q223R gene polymorphism was analyzed in a sample of obese and nonobese individuals from Brazil to evaluate the role of this polymorphism in the obese phenotype in the population. Two hundred obese patients (60 males, 140 females, body mass index (BMI) >30 kg/m2) were screened, together with 150 lean or normal healthy individuals (63 males, 87 females, BMI <24 kg/m2). Genomic DNA was extracted and amplified by polymerase chain reaction (PCR). PCR products were digested with the restriction of endonuclease MspI, and separated by electrophoresis through an 8% polyacrilamide gel stained with silver nitrate. There was a significant difference in LEPR p.Q223R polymorphism frequency when comparing obese and lean subjects, with an odds ratio of 1.92 and a 95% confidence interval of 1.15–3.22 (P = 0.013). There is a strong association of the LEPR p.Q223R gene polymorphism with obesity in Brazil. Am. J. Hum. Biol. 18:448–453, 2006. © 2006 Wiley‐Liss, Inc.
Functions of corticotropin‐releasing hormone in anthropoid primates: From brain to placenta
Authors: Power Michael L. , Schulkin Jay
Published: June 2006

Corticotropin‐releasing hormone (CRH) is an ancient regulatory molecule. The CRH hormone family has at least four ligands, two receptors, and a binding protein. Its well‐known role in the hypothalamic‐pituitary‐adrenal (HPA) axis is only one of many. The expression of CRH and its related peptides is widespread in peripheral tissue, with important functions in the immune system, energy metabolism, and female reproduction. For example, CRH is involved in the implantation of fertilized ova and in maternal tolerance to the fetus. An apparently unique adaptation has evolved in anthropoid primates: placental expression of CRH. Placental CRH stimulates the fetal adrenal zone, an adrenal structure unique to primates, to produce dehydroepiandrosterone sulfate (DHEAS), which is converted to estrogen by the placenta. Cortisol induced from the fetal and maternal adrenal glands by placental CRH induces further placental CRH expression, forming a positive feedback system that results in increasing placental production of estrogen. In humans, abnormally high placental expression of CRH is associated with pregnancy complications (e.g., preterm labor, intrauterine growth restriction (IUGR), and preeclampsia). Within anthropoid primates, there are at least two patterns of placental CRH expression over gestation: monkeys differ from great apes (and humans) by having a midgestational peak in CRH expression. The functional significance of these differences between monkeys and apes is not yet understood, but it supports the hypothesis that placental CRH performs multiple roles during gestation. A clearer understanding of the diversity of patterns of placental CRH expression among anthropoid primates would aid our understanding of its role in human pregnancy. Am. J. Hum. Biol. 18:431–447, 2006. © 2006 Wiley‐Liss, Inc.
Explaining sex differences in dental caries prevalence: Saliva, hormones, and “life‐history” etiologies
Authors: Lukacs John R. , Largaespada Leah L.
Published: June 2006

When dental caries rates are reported by sex, females are typically found to exhibit higher prevalence rates than males. This finding is generally true for diverse cultures with different subsistence systems and for a wide range of chronological periods. Exceptions exist, but are not common. In this paper, we present new data for sex differences in dental caries rates among the Guanches (Tenerife, Canary Islands), summarize results of meta‐analyses of dental caries prevalence, and emphasize new research that stresses the critical role of female hormones and life‐history events in the etiology of dental caries. Among the Guanches, corrected tooth‐count caries rates for females (8.8%, 158/1,790) are approximately twice the frequency of caries among males (4.5%, 68/1,498). Higher caries prevalence among females is often explained by one of three factors: 1) earlier eruption of teeth in girls, hence longer exposure of girls' teeth to the cariogenic oral environment, 2) easier access to food supplies by women and frequent snacking during food preparation, and 3) pregnancy. Anthropologists tend to favor explanations involving behavior, including sexual division of labor and women's domestic role in food production. By contrast, the causal pathways through which pregnancy contributes to poorer oral health and higher caries rates are deemphasized or discounted. This paper presents recent research on physiological changes associated with fluctuating hormone levels during individual life histories, and the impact these changes have on the oral health of women. The biochemical composition of saliva and overall saliva flow rate are modified in several important ways by hormonal fluctuations during events such as puberty, menstruation, and pregnancy, making the oral environment significantly more cariogenic for women than for men. These results suggest that hormonal fluctuations can have a dramatic effect on the oral health of women, and constitute an important causal factor in explaining sex differences in caries rates. Am. J. Hum. Biol. 18:540–555, 2006. © 2006 Wiley‐Liss, Inc.
The mean‐field approximation in quantum electrodynamics: The no‐photon case
Authors: Hainzl Christian , Lewin Mathieu , Solovej Jan Philip
Published: June 2006

We study the mean‐field approximation of quantum electrodynamics (QED) by means of a thermodynamic limit. The QED Hamiltonian is written in Coulomb gauge and does not contain any normal ordering or choice of bare electron/positron subspaces. Neglecting photons, we properly define this Hamiltonian in a finite box [−L/2; L/2)3, with periodic boundary conditions and an ultraviolet cutoff λ. We then study the limit of the ground state (i.e., the vacuum) energy and of the minimizers as L goes to infinity, in the Hartree‐Fock approximation.

In the case with no external field, we prove that the energy per volume converges and obtain in the limit a translation‐invariant projector describing the free Hartree‐Fock vacuum. We also define the energy per unit volume of translation‐invariant states and prove that the free vacuum is the unique minimizer of this energy.

In the presence of an external field, we prove that the difference between the minimum energy and the energy of the free vacuum converges as L goes to infinity. We obtain in the limit the so‐called Bogoliubov‐Dirac‐Fock functional. The Hartree‐Fock (polarized) vacuum is a Hilbert‐Schmidt perturbation of the free vacuum and it minimizes the Bogoliubov‐Dirac‐Fock energy. © 2006 Wiley Periodicals, Inc.
Branch to colony trajectory in a modular organism: Pattern formation in the Indo‐Pacific coral Stylophora pistillata
Authors: Shaish Lee , Abelson Avigdor , Rinkevich Baruch
Published: June 2006

The architecture of the colony in a branching coral is an iterative process in which new layers of calcium carbonate compile atop existing structures that remain unchanged. Colony growth and development, known as astogeny, is believed to be a continuous process, characterized by replication of lower rank unites, polyps, and branches. This study seeks to explore the genetic blueprint of branch‐to‐colony developmental trajectory in the branching coral Stylophora pistillata, within an astogeny period of 1 year. One hundred small branches (initially 2–4 cm long) were sampled from 10 colonies. A year later, 63 remaining colonies were analyzed for their architectural rules by using 15 morphometric parameters. Multivariate statistical tests were preformed. Cluster and two‐dimensional nonmetric Multi‐Dimensional Scaling analyses revealed that the 10 genotypes could be divided into two major morphometric groups and two intermediate groups, whereas SIMPER analyses (a similarity percentage test) on within‐genet similarities showed high similarity between the ramets developed from each of the 10 genotypes. Although, at first, it seemed that different colonies exhibited variable and different architectural designs (each characterized by specific morphometric parameters), a comprehensive analysis revealed that all 10 coral genotypes exhibited a single common developmental plan that was characterized by a continuum of architectural design with several distinct stages. Each stage is marked by its own characteristic morphometric parameters. Changing of developmental rules during the trajectory from branch to coral colony may help the colony to cope better with environmental constraints. Developmental Dynamics 235:2111–2121, 2006. © 2006 Wiley‐Liss, Inc.
The biocompatibility and osteoconductivity of a cement containing β–TCP for use in vertebroplasty
Authors: Goto K. , Shinzato S. , Fujibayashi S. , Tamura J. , Kawanabe K. , Hasegawa S. , Kowalski R. , Nakamura T.
Published: June 2006

A new composite bone cement designated “G2B1” was developed for percutaneous transpedicular vertebroplasty. G2B1 contains beta tricalcium phosphate particles and methylmethacrylate–methylacrylate copolymer as the powder components, and methylmethacrylate, urethane dimethacrylate, and tetrahydrofurfuryl methacrylate as the liquid components. Biocompatibility and osteoconductivity were evaluated using scanning electron microscopy, contact microradiography, and Giemsa surface staining 4, 8, 12, 26, and 52 weeks after implantation into rat tibiae. To evaluate osteoconductivity, affinity indices (%) were calculated. Scanning electron microscopy and contact microradiography revealed that bone contact with G2B1 was attained within 4 weeks (affinity index: 50.2 ± 11.8 at 4 weeks) and at most of the margin within 26 weeks (affinity index: 87.4 ± 7.2 at 26 weeks). Specifically, G2B1 contacted bone via a wide calcium–phosphate‐rich layer, and its degradation started within 8 weeks, mainly in the marginal area. Giemsa surface staining showed that there was almost no inflammatory reaction around the G2B1. These results indicate that G2B1 is a biocompatible and osteoconductive bone cement. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006