bluuebunny/crossref_metadata_2025 huggingface dataset:
Brain Correlates of Stuttering and Syllable Production
Authors: Ingham Roger J. , Fox Peter T. , Ingham Janis C. , Xiong Jinhu , Zamarripa Frank , Hardies L. Jean , Lancaster Jack L.
Published: April 2006

This article reports a gender replication study of the P. T. Fox et al. (2000) performance correlation analysis of neural systems that distinguish between normal and stuttered speech in adult males. Positron-emission tomographic (PET) images of cerebral blood flow (CBF) were correlated with speech behavior scores obtained during PET imaging for 10 dextral female stuttering speakers and 10 dextral, age- and sex-matched normally fluent controls. Gender comparisons were made between the total number of voxels per region significantly correlated with speech performance (as in P. T. Fox et al., 2000) plus total voxels per region that were significantly correlated with stutter rate and not with syllable rate.

Stutter-rate regional correlates were generally right-sided in males, but bilateral in the females. For both sexes the positive regional correlates for stuttering were in right (R) anterior insula and the negative correlates were in R Brodmann area 21/22 and an area within left (L) inferior frontal gyrus. The female stuttering speakers displayed additional positive correlates in L anterior insula and in basal ganglia (L globus pallidus, R caudate), plus extensive right hemisphere negative correlates in the prefrontal area and the limbic and parietal lobes. The male stuttering speakers were distinguished by positive correlates in L medial occipital lobe and R medial cerebellum. Regions that positively correlated with syllable rate (essentially stutter-free speech) in stuttering speakers and controls were very similar for both sexes.

The findings strengthen claims that chronic developmental stuttering is functionally related to abnormal speech-motor and auditory region interactions. The gender differences may be related to differences between the genders with respect to susceptibility (males predominate) and recovery from chronic stuttering (females show higher recovery rates during childhood).
The Development of Early Literacy Skills Among Children With Speech Difficulties
Authors: Nathan Liz , Stackhouse Joy , Goulandris Nata , Snowling Margaret J.
Published: April 2006

This article presents a longitudinal study of the early literacy development of 47 children with speech difficulties from ages 4 to 7 years. Of these children, 19 with specific speech difficulties were compared with 19 children with speech and language difficulties and 19 normally developing controls. The risk of literacy difficulties was greater in the group with speech and language difficulties, and these children displayed deficits in phoneme awareness at 6 years. In contrast, the literacy development of children with isolated speech problems was not significantly different from that of controls. A path analysis relating early speech, language, and literacy skills indicated that preschool language ability was a unique predictor of phoneme awareness at 5;8 (years; months), which, together with early reading skill, predicted literacy outcome at 6;9. Once the effects of phoneme awareness were controlled, neither speech perception nor speech production processes predicted variation in literacy skills. However, it is noteworthy that children with persisting speech difficulties at 6;9 were particularly vulnerable to deficits in reading-related processes.
Examining Multiple Sources of Influence on the Reading Comprehension Skills of Children Who Use Cochlear Implants
Authors: Connor Carol McDonald , Zwolan Teresa A.
Published: April 2006

Children with profound deafness are at risk for serious reading difficulties. Multiple factors affect their development of reading skills, including use of cochlear implants. Further, multiple factors influence the overall success that children experience with their cochlear implants. These factors include the age at which they receive an implant, method of communication, vocabulary skills, preoperative residual hearing, and socioeconomic status. Ninety-one children with prelingual and profound hearing impairments who received cochlear implants at varying ages participated in the study. Structural equation modeling confirmed that multiple factors affected young cochlear implant users' reading comprehension skills and that there were significant associations between the predictors of reading comprehension. Pre-implant vocabulary had an indirect positive effect on reading through postimplant vocabulary, which had a direct positive effect on reading. Overall, children with stronger language skills demonstrated stronger reading outcomes. Age at implantation both directly and indirectly, through postimplant vocabulary, affected reading outcomes, and the total effect was large. Children who were younger when they received their implants tended to have higher reading comprehension scores. Socioeconomic status negatively affected reading. Children who used total communication prior to implantation tended to have stronger pre-implant vocabulary scores, but the total effect of pre-implant communication method on children's reading skills was negligible. Research and educational implications are discussed.
Voice Disorders in Teachers and the General Population
Authors: Roy Nelson , Merrill Ray M. , Thibeault Susan , Gray Steven D. , Smith Elaine M.
Published: April 2006

To examine the frequency and adverse effects of voice disorders on job performance and attendance in teachers and the general population, 2,401 participants from Iowa and Utah (
n
1
=1,243 teachers and
n
2
=1,279 nonteachers) were randomly selected and were interviewed by telephone using a voice disorder questionnaire. Teachers were significantly more likely than nonteachers to have experienced multiple voice symptoms and signs including hoarseness, discomfort, and increased effort while using their voice, tiring or experiencing a change in voice quality after short use, difficulty projecting their voice, trouble speaking or singing softly, and a loss of their singing range (all odds ratios [ORs]
p
<.05). Furthermore, teachers consistently attributed these voice symptoms to their occupation and were significantly more likely to indicate that their voice limited their ability to perform certain tasks at work, and had reduced activities or interactions as a result. Teachers, as compared with nonteachers, had missed more workdays over the preceding year because of voice problems and were more likely to consider changing occupations because of their voice (all comparisons
p
<.05). These findings strongly suggest that occupationally related voice dysfunction in teachers can have significant adverse effects on job performance, attendance, and future career choices.
The Relationship of Language and Emotion Regulation Skills to Reticence in Children With Specific Language Impairment
Authors: Fujiki Martin , Spackman Matthew P. , Brinton Bonnie , Hall Andrea
Published: April 2006

This study examined the relationship between emotion regulation, language ability, and reticent behavior in children with specific language impairment (SLI) and their typical peers. Participants included 43 children with SLI and 43 typically developing children, for a total sample of 86 participants. Children were selected from 2 age ranges: 5–8 years and 9–12 years. The Emotion Regulation Checklist (ERC; A. Shields & D. Cicchetti, 1997, 1998) and the Teacher Behavior Rating Scale (TBRS; C. H. Hart & C. C. Robinson, 1996) were completed by each child’s teacher to provide measures of emotion regulation and reticence, respectively. The Comprehensive Assessment of Spoken Language (CASL; E. Carrow-Woodfolk, 1999) was administered to provide a measure of language ability. A regression analysis including all participants indicated that the emotion regulation scores and the CASL scores were significant predictors of the reticence scores, accounting for 43% of the variance. Group-specific analyses were then conducted to determine whether the 2 predictor scales differentially predicted reticence based on language and age groups. None of the tests exceeded the.05 level, indicating that there was no significant difference in predictive power on the 2 factors in question.

KEY WORDS: emotion regulation, language impairment, reticence, withdrawal, socioemotional
The Relationship Between Social Behavior and Severity of Language Impairment
Authors: Hart Kerstine I. , Fujiki Martin , Brinton Bonnie , Hart Craig H.
Published: April 2006

The Teacher Behavior Rating Scale (C. H. Hart & C. C. Robinson, 1996) was used to compare the withdrawn and sociable behaviors of 41 children with specific language impairment (SLI) and 41 typically developing peers. Three subtypes of withdrawal (reticence, solitary-active, solitary-passive) and 2 subtypes of sociable behavior (prosocial, impulse control/likeability) were examined. Teachers rated children with SLI as exhibiting higher levels of reticence and solitary-passive withdrawal than typical children. Teachers also rated the children with SLI as demonstrating lower levels of both types of sociable behavior than typical children. The group with SLI was then separated into subgroups of children having more severe and less severe language impairment. These groupings did not differ on comparisons involving withdrawn behavior, except that girls with more severe receptive problems demonstrated higher levels of solitary-passive withdrawal than did girls with less severe language problems. Children with less severe receptive language impairment demonstrated higher levels of proficiency on both types of sociable behavior than their peers with more severe impairment. Children with more severe expressive problems also demonstrated poorer prosocial behavior—but not poorer impulse control/likeability—than children with less severe expressive problems.

KEY WORDS
: social skills, language impairment, socioemotional, withdrawal, social competence
Effects of Speech and Print Feedback on Spelling by Children With Autism
Authors: Schlosser Ralf W. , Blischak Doreen M.
Published: April 2006

In this systematic replication of a previous study (R. W. Schlosser, D. M. Blischak, P. J. Belfiore, C. Bartley, & N. Barnett, 1998), the effects of speech and print feedback on spelling performance were evaluated. Four children with autism and no functional speech were taught to spell words with a speech-generating device under 3 feedback conditions. In the auditory-visual condition, children received both speech and print feedback, whereas in the auditory and visual conditions, only 1 type of feedback was provided. An adapted alternating treatments design was used. All 4 children reached criterion across conditions. Although 3 children reached criterion first with print or speech-print feedback, 1 child was most efficient with speech-print followed by speech feedback. Based on the findings of both studies, 2 distinct profiles of feedback efficiency are proposed. Children that exemplify the primarily visual profile spell words most efficiently when feedback involves print. Children that fit the auditory profile spell words most efficiently when feedback involves speech. The implications for understanding the learning characteristics of children with autism, as well as those for practice and further research are derived.
Genetic, Environmental, and Gender Effects on Individual Differences in Toddler Expressive Language
Authors: Hulle Carol A. Van , Goldsmith H. H. , Lemery Kathryn S.
Published: April 2006

In this article, the authors examined the genetic and environmental factors influencing expressive language development in a sample of 386 toddler twin pairs participating in the Wisconsin Twin Project. Expressive language was assessed using 2 measures from the MacArthur Communicative Development Inventories-Short Form: Total Vocabulary and Two-Word Combination Use (L. Fenson et al., 2000). A sex-limitation structural equation model estimated the contribution of genetics, shared environment, and nonshared environment to individual variation. For vocabulary, heritability was higher for boys than for girls (20% vs. 8%). For word combination use, heritability was higher for girls (28% vs. 10%). However, the majority of individual variation in both boys and girls could be attributed to shared environment (54%–78%).

KEY WORDS: twins, language, toddlerhood, gender differences
Nonword Repetition by Children With Cochlear Implants
Authors: Dillon Caitlin M. , Burkholder Rose A. , Cleary Miranda , Pisoni David B.
Published: April 2006

Seventy-six children with cochlear implants completed a nonword repetition task. The children were presented with 20 nonword auditory patterns over a loud-speaker and were asked to repeat them aloud to the experimenter. The children's responses were recorded on digital audiotape and then played back to normal-hearing adult listeners to obtain accuracy ratings on a 7-point scale. The children's nonword repetition performance, as measured by these perceptual accuracy ratings, could be predicted in large part by their performance on independently collected measures of speech perception, verbal rehearsal speed, and speech production. The strongest contributing variable was speaking rate, which is widely argued to reflect verbal rehearsal speed in phonological working memory. Children who had become deaf at older ages received higher perceptual ratings. Children whose early linguistic experience and educational environments emphasized oral communication methods received higher perceptual ratings than children enrolled in total communication programs. The present findings suggest that individual differences in performance on nonword repetition are strongly related to variability observed in the component processes involved in language imitation tasks, including measures of speech perception, speech production, and especially verbal rehearsal speed in phonological working memory. In addition, onset of deafness at a later age and an educational environment emphasizing oral communication may be beneficial to the children's ability to develop the robust phonological processing skills necessary to accurately repeat novel, nonword sound patterns.
Relationships Between Nonword Repetition Accuracy and Other Measures of Linguistic Development in Children With Phonological Disorders
Authors: Munson Benjamin , Edwards Jan , Beckman Mary E.
Published: April 2006

A growing body of research has documented effects of phonotactic probability on young children's nonword repetition. This study extends this research in 2 ways. First, it compares nonword repetitions by 40 young children with phonological disorders with those by 40 same-age peers with typical phonological development on a nonword repetition task in which the frequency of embedded diphone sequences was varied. Second, it examines the relationship between the frequency effect in the nonword repetition task and other measures of linguistic ability in these children. Children in both groups repeated low-frequency sequences less accurately than high-frequency sequences. The children with phonological disorders were less accurate overall but showed no larger disadvantage for the low-frequency sequences than their age peers. Across the group, the size of the frequency effect was correlated with vocabulary size, but it was independent of measures of speech perception and articulatory ability. These results support the hypothesis that the production difficulty associated with low/frequency sequences is related primarily to vocabulary growth rather than to developments in articulatory or perceptual ability. By contrast, production problems experienced by children with phonological disorders do not appear to result from difficulties in making abstractions over known lexical items. Instead, they may be associated with difficulties in building representations in the primary sensory and motor domains.
The Role of Home Literacy Practices in Preschool Children's Language and Emergent Literacy Skills
Authors: Roberts Joanne , Jergens Julia , Burchinal Margaret
Published: April 2006

This study examined how 4 specific measures of home literacy practices (i.e., shared book reading frequency, maternal book reading strategies, child's enjoyment of reading, and maternal sensitivity) and a global measure of the quality and responsiveness of the home environment during the preschool years predicted children's language and emergent literacy skills between the ages of 3 and 5 years. Study participants were 72 African American children and their mothers or primary guardians primarily from low-income families whose home literacy environment and development have been followed since infancy. Annually, between 18 months and 5 years of age, the children's mothers were interviewed about the frequency they read to their child and how much their child enjoyed being read to, and the overall quality and responsiveness of the home environment were observed. Mothers also were observed reading to their child once a year at 2, 3, and 4 years of age, and maternal sensitivity and types of maternal book reading strategies were coded. Children's receptive and expressive language and vocabulary were assessed annually between 3 years of age and kindergarten entry, and emergent literacy skills were assessed at 4 years and kindergarten entry. The specific home literacy practices showed moderate to large correlations with each other, and only a few significant associations with the language and literacy outcomes, after controlling for maternal education, maternal reading skills, and the child's gender. The global measure of overall responsiveness and support of the home environment was the strongest predictor of children's language and early literacy skills and contributed over and above the specific literacy practice measures in predicting children's early language and literacy development.
Measurement of Vocal Fold Collision Forces During Phonation
Authors: Gunter Heather E. , Howe Robert D. , Zeitels Steven M. , Kobler James B. , Hillman Robert E.
Published: April 2006

Forces applied to vocal fold tissue as the vocal folds collide may cause tissue injury that manifests as benign organic lesions. A novel method for measuring this quantity in humans in vivo uses a low-profile force sensor that extends along the length and depth of the glottis. Sensor design facilitates its placement and stabilization so that phonation can be initiated and maintained while it is in place, with minimal interference in vocal fold vibration. In 2 individuals with 1 vibrating vocal fold and 1 nonvibrating vocal fold, peak collision force correlates more strongly with voice intensity than pitch. Vocal fold collision forces in 1 individual with 2 vibrating vocal folds are of the same order of magnitude as in previous studies. Correlations among peak collision force, voice intensity, and pitch were indeterminate in this participant because of the small number of data points. Sensor modifications are proposed so that it can be used to reliably estimate collision force in individuals with 2 vibrating vocal folds and with changing vocal tract conformations.
Frequency Discrimination and Literacy Skills in Children With Mild to Moderate Sensorineural Hearing Loss
Authors: Halliday L. F. , Bishop D. V. M.
Published: April 2006

It has been suggested that specific reading disability (SRD) may be attributable to an impaired ability to perceive spectral differences between sounds that leads to a deficit in frequency discrimination and subsequent problems with language and literacy. The objective of the present study was threefold. We aimed to (a) determine whether children with mild to moderate sensorineural hearing loss were impaired in their ability to discriminate frequency, (b) assess the extent to which any such deficits may be due to an inability to use information derived from phase locking, and (c) examine whether frequency discrimination abilities were predictive of measures of word and nonword reading and nonword repetition. Difference limens for frequency (DLFs) were obtained for 22 children with mild to moderate hearing loss (SNH group) and 22 age-matched controls (CA group) at central frequencies of 1 kHz, where phase-locking information is available, and 6 kHz, where it is not. A battery of standardized tests of language and literacy was also administered. The SNH group exhibited significantly elevated DLFs at both 1 and 6 kHz relative to controls, despite considerable variability of thresholds in both groups. Although no group differences were found for receptive and expressive vocabulary, receptive grammar, and nonword reading, the SNH group performed worse than controls on word reading and nonword repetition, even though word reading acores were age-appropriate. Frequency discrimination abilities were associated with reading and nonword repetition across groups, but these correlations largely disappeared when the two groups were analyzed separately. Together, these results provide evidence for a dissociation between impaired frequency discrimination and relatively "spared" language and literacy in children with mild to moderate sensorineural hearing loss. These results cast doubt on the assertion that a deficit in frequency discrimination necessarily leads to marked deficits in the development of language and literacy.
Breath-Group Intelligibility in Dysarthria
Authors: Yunusova Yana , Weismer Gary , Kent Ray D. , Rusche Nicole M.
Published: April 2006

Purpose:
This study was designed to determine whether within-speaker fluctuations in speech intelligibility occurred among speakers with dysarthria who produced a reading passage, and, if they did, whether selected linguistic and acoustic variables predicted the variations in speech intelligibility.

Method:
Participants with dysarthria included a total of 10 persons with Parkinson's disease and amyotrophic lateral sclerosis; a control group of 10 neurologically normal speakers was also studied. Each participant read a passage that was subsequently separated into consecutive breath groups for estimates of individual breath group intelligibility. Sixty listeners participated in 2 perceptual experiments, generating intelligibility scores across speakers and for each breath group produced by speakers with dysarthria.

Results:
Individual participants with dysarthria had fluctuations in intelligibility across breath groups. Breath groups of participants with dysarthria had fewer average words and reduced interquartile ranges for the 2nd formant, the latter a global measure of articulatory mobility. Regression analyses with intelligibility measures as the criterion variable and linguistic and acoustic measures as predictor variables produced significant functions both within and across speakers, but the solutions were not the same.

Conclusions:
Linguistic or acoustic variables that predict across-speaker variations in speech intelligibility may not function in the sameway when within-speaker variations in intelligibility are considered.
The Effect of Semantic Representation on Toddlers' Word Retrieval
Authors: Capone Nina C. , McGregor Karla K.
Published: April 2006

Purpose:
This study tested the hypothesis that depth of semantic representation influences toddlers' word retrieval.

Method:
Nineteen toddlers participated under 3 word learning conditions in this longitudinal study. Gestures cued attention to object shape (SHP) or function (FNC) in the experimental conditions. No semantic cue was provided under a control condition (CTL). Word learning conditions occurred on each of 3 days. On the 4th day, word retrieval was assessed across 3 levels of scaffolding (uncued picture naming, cued picture naming, picture recognition). Evidence of semantic representation was provided at fast and slow mapping intervals.

Results:
Less scaffolding was necessary for word retrieval (uncued and cued naming) under experimental conditions than under the CTL condition. However, more SHP than FNC condition targets were retrieved for uncued picture naming. This latter difference may be related to the superior fast mapping of targets under the SHP condition. Toddlers stated object functions (slow mapping) comparably in the experimental conditions, but this was superior to CTL condition performance.

Conclusions:
Word retrieval is a continuous behavior that is positively influenced by semantic representation. Semantic knowledge of objects can be enriched by shape or function gestures, thereby improving toddlers' object word productions. Shape cues appear to be more effective for this purpose.
Selectivity principle of the ligand escape process from a two-gate tunnel in myoglobin: Molecular dynamics simulation
Authors: Sheu Sheh-Yi
Published: April 2006

We proposed a selectivity principle for the ligand escape process from two fluctuating bottlenecks in a cavity with a multigate inside a myoglobin pocket. Our previous analytical theory proposed a fluctuating bottleneck model for a Brownian particle passing through two gates on a cavity surface of an enzyme protein and has determined the escape rate in terms of the time-dependent gate function and the competition effect. It illustrated that with two (or more than two) gates on a cavity surface the gate modulation, which is controlled by protein fluctuation, dominates the ligand escape pathway. We have performed a molecular dynamics simulation to investigate the selectivity principle of the ligand escape process from two-gate tunnel in myoglobin. The simulation results confirm our theoretical conjecture. It indicates that the escape process is actually entropy driven, and the ligand escape pathway is chosen via the gate modulation. This suggests an interesting intrinsic property, that is, the oxymyoglobin tertiary structure is favorable to the departure of the ligand from one direction rather than through a biased random walk.
A quantum mechanical scheme to reduce radiation damage in electron microscopy
Authors: Okamoto Hiroshi , Latychevskaia Tatiana , Fink Hans-Werner
Published: April 2006

We show that radiation damage to unstained biological specimens is not an intractable problem in electron microscopy. When a structural hypothesis of a specimen is available, quantum mechanical principles allow us to verify the hypothesis with a very low electron dose. Realization of such a concept requires precise control of the electron wave front. Based on a diffractive electron optical implementation, we demonstrate the feasibility of this new method by both experimental and numerical investigations.
Effects of hydroxyl groups in polymeric dielectrics on organic transistor performance
Authors: Lee Sangyun , Koo Bonwon , Shin Joonghan , Lee Eunkyong , Park Hyunjeong , Kim Hyoungsub
Published: April 2006

Polymeric dielectrics having different ratios of hydroxyl groups were intentionally synthesized to investigate the effect of hydroxyl groups on the electrical properties of pentacene-based organic thin film transistors (OTFTs). Large hysteresis usually observed in OTFT devices was confirmed to be strongly related to the hydroxyl bonds existing inside of polymeric dielectrics and could be reduced by substituting with cinnamoyl groups. Although the hydroxyl groups deteriorate the capacitance-voltage characteristics and gate leakage current densities, exceptionally high hole mobility (5.5cm2V−1s−1) could be obtained by increasing the number of hydroxyl groups, which was not caused by the improvement of pentacene crystallinity but related to the interface characteristics.
Light amplification at 501nm and large nanosecond optical gain in organic dye-doped polymeric waveguides
Authors: Jordan Grace , Flämmich Michael , Rüther Manuel , Kobayashi Takeyuki , Blau Werner J. , Suzuki Yasuhiro , Kaino Toshikuni
Published: April 2006

We report on the results of a gain measurement on a substituted stilbene-dye-doped polymer waveguide operating in the blue-green spectral region. By monitoring amplified spontaneous emission from the waveguides under nanosecond photopumping, we deduced net modal gain as large as 84±6cm−1 at 501nm, the peak of the gain spectrum, when pumped with a fluence of 1.1mJ∕cm2. Moreover, the effective stimulated emission cross section of 2.7×10−16cm2 and the loss coefficient of 0.3cm−1 at 501nm are extracted. The transparency pump fluence and the corresponding excited state population density are found to be 17μJ∕cm2 and 8.8×1015cm−3 which is approximately 0.1% of total population, respectively. Comparison is made with other organic and inorganic gain media operating in the short wavelength (violet-green) region of the spectrum. We demonstrate that small-molecule-doped polymers show large gain, comparable with those in conjugated polymers and dendrimers.
Development of bat flight: Morphologic and molecular evolution of bat wing digits
Authors: Sears Karen E. , Behringer Richard R. , Rasweiler John J. , Niswander Lee A.
Published: April 2006

The earliest fossil bats resemble their modern counterparts in possessing greatly elongated digits to support the wing membrane, which is an anatomical hallmark of powered flight. To quantitatively confirm these similarities, we performed a morphometric analysis of wing bones from fossil and modern bats. We found that the lengths of the third, fourth, and fifth digits (the primary supportive elements of the wing) have remained constant relative to body size over the last 50 million years. This absence of transitional forms in the fossil record led us to look elsewhere to understand bat wing evolution. Investigating embryonic development, we found that the digits in bats (
Carollia perspicillata
) are initially similar in size to those of mice (
Mus musculus
) but that, subsequently, bat digits greatly lengthen. The developmental timing of the change in wing digit length points to a change in longitudinal cartilage growth, a process that depends on the relative proliferation and differentiation of chondrocytes. We found that bat forelimb digits exhibit relatively high rates of chondrocyte proliferation and differentiation. We show that bone morphogenetic protein 2 (Bmp2) can stimulate cartilage proliferation and differentiation and increase digit length in the bat embryonic forelimb. Also, we show that
Bmp2
expression and Bmp signaling are increased in bat forelimb embryonic digits relative to mouse or bat hind limb digits. Together, our results suggest that an up-regulation of the Bmp pathway is one of the major factors in the developmental elongation of bat forelimb digits, and it is potentially a key mechanism in their evolutionary elongation as well.
Arf
gene loss enhances oncogenicity and limits imatinib response in mouse models of Bcr-Abl-induced acute lymphoblastic leukemia
Authors: Williams Richard T. , Roussel Martine F. , Sherr Charles J.
Published: April 2006

Mouse bone marrow cells transduced with retroviral vectors encoding either of two oncogenic Bcr-Abl isoforms (p210
Bcr-Abl
and p185
Bcr-Abl
) induce B cell lympholeukemias when transplanted into lethally irradiated mice. If the activity of the
Arf
tumor suppressor is compromised, these donor cells initiate a much more highly aggressive and rapidly fatal disease. When mouse bone marrow cells expressing Bcr-Abl are placed in short-term cultures selectively designed to support the outgrowth of pre-B cells, only those lacking one or two
Arf
alleles can initiate lympholeukemias when inoculated into immunocompetent, syngeneic recipient mice. Although the ABL kinase inhibitor imatinib mesylate (Gleevec) provides highly effective treatment for BCR-ABL-positive chronic myelogenous leukemia, it has proven far less efficacious in the treatment of BCR-ABL-positive acute lymphoblastic leukemias (ALLs), many of which sustain deletions of the
INK4A-ARF
(
CDKN2A
) tumor suppressor locus. Mice receiving
Arf
−/−
or
Arf
+/−
p210
Bcr-Abl
-positive pre-B cells do not achieve remission when maintained on high doses of oral imatinib therapy and rapidly succumb to lympholeukemia. Although cells expressing the Bcr-Abl kinase can proliferate in the absence of IL-7, they remain responsive to this cytokine, which can reduce their sensitivity to imatinib. Treatment of
Arf
−/−
, p210
Bcr-Abl
-positive pre-B cells with imatinib together with an inhibitor of JAK kinases abrogates this resistance, suggesting that this combination may prove beneficial in the treatment of BCR-ABL-positive acute lymphoblastic leukemia.
Cholesterol deficiency in a mouse model of Smith-Lemli-Opitz syndrome reveals increased mast cell responsiveness
Authors: Kovarova Martina , Wassif Christopher A. , Odom Sandra , Liao Katherine , Porter Forbes D. , Rivera Juan
Published: April 2006

Mutation of the 3β-hydroxysterol Δ7-reductase gene (Dhcr7−/−) results in Smith-Lemli-Opitz syndrome (SLOS). Patients, and genetically altered mice, are unable to produce cholesterol and accumulate 7-dehydrocholesterol (DHC) in serum and tissue. This causes multiple growth and developmental abnormalities as well as immune system anomalies including allergy. Because cholesterol is a key component of liquid-ordered membranes (lipid rafts) and these domains have been implicated in regulating mast cell activation, we examined whether mast cell responsiveness is altered in this model. Mast cells derived from Dhcr7−/− mice (DHCR KO) showed constitutive cytokine production and hyper-degranulation after stimulation of the high affinity IgE receptor (FcεRI). DHCR KO mast cells, but not wild-type mast cells, accumulated DHC in lipid rafts. DHC partially disrupted lipid raft stability and displaced Lyn kinase protein and activity from lipid rafts. This led to down-regulation of some Lyn-dependent signaling events but increased Fyn kinase activity and Akt phosphorylation. The Lyn-dependent phosphorylation of Csk-binding protein, which negatively regulates Fyn activity, was decreased. This phenotype reproduces some of the characteristics of Lyn-null mast cells, which also demonstrate hyper-degranulation. These findings provide the first evidence of lipid raft dysfunction in SLOS and may explain the observed association of allergy with SLOS.
Exploratory factor analysis of the research and development culture index among qualified nurses
Authors: Watson Bill , Clarke Charlotte , Swallow Vera , Forster Stewart
Published: April 2006

Aims and objectives.  This paper presents the exploratory factor analysis of a rating instrument for assessing the strength of organizational Research and Development (R&D) culture.

Background.  Despite nursing's limited research capacity, the discipline is capitalising upon opportunities to become involved in research and is making strong progress. Within the context of the debate on nursing research capacity, the R&D Culture Index was developed as a means of appraising R&D culture within health care organizations.

Design.  Factor analysis was carried out on data collected from 485 nursing staff. The method of extraction was Principal Components Analysis with oblique rotation.

Methods.  The Index was developed from the findings of qualitative research conducted with NHS staff. Eighteen items, encompassing the main themes from the data, were initially included in the Index. This pilot instrument was distributed to nursing staff within three different types of NHS Trust. Factor analysis resulted in rejection of two items and the analysis was repeated using the remaining 16 items.

Results.  Three latent factors were extracted accounting for 58·0% of the variance in the data. The factors were: R&D Support, describing the perceived support within the working environment for R&D activity; Personal R&D Skills and Aptitude, describing an individual's perception of their ability towards R&D activity; and Personal R&D Intention, describing an individual's willingness to engage in R&D activity. Each factor had good internal reliability, as did the overall index.

Conclusion.  The R&D Culture Index provides an efficient means of assessing the strength of an organization's R&D culture in a way that captures the role of the individual practitioner and the organizational environment.

Relevance to practice.  These findings suggest that the continuing promotion of R&D within health care organizations is dependent upon a multi‐faceted approach that addresses the learning needs of the organization as well as those of the individual practitioners.
Do trait anxiety and age predict state anxiety of school‐age children?
Authors: William Li Ho Cheung , Lopez Violeta
Published: April 2006

Aim.  The aim of this study was to determine whether the trait anxiety scores and age of children could predict their state anxiety scores under stressful and relaxing situations.

Background.  Surgery can cause considerable stress and anxiety that can have a profound effect on children. It is crucial for nurses to differentiate preoperative anxiety levels in children and to identify those children who are most likely to exhibit high levels of anxiety when undergoing surgery before any intervention can be appropriately planned, provided and evaluated.

Methods.  A test‐retest within subjects design was used. Five hundred and nineteen primary school‐age children were invited to participate in the study. Participants were asked to respond to the Chinese version of the State‐Trait Anxiety Inventory for Children under stressful (pre‐academic examination) and relaxing (post‐academic examination) situations.

Result.  Multiple regression analysis showed that the trait anxiety of children was a strong predictor of their state anxiety in a stressful situation but not in a relaxed one. Compared to trait anxiety, age was found to be a weak predictor of the state anxiety of children in either situation.

Conclusion.  This study confirmed that trait anxiety of children could be predicted from their state anxiety under a stressful situation.

Relevance to clinical practice.  The trait anxiety scale could be a useful screening tool for nurses to identify those children who are most likely to exhibit high levels of anxiety when undergoing surgery. Understanding the trait anxiety of children in advance could help nurses implement appropriate preoperative psychological intervention that can meet the individual needs of the child and thus promote better recovery.
IL‐6 and IL‐8 response to erythropoietin therapy in radical hysterectomy
Authors: Hyllner M. , Åvall A. , Bengtson J.‐P. , Bengtsson A.
Published: April 2006

Background:  The use of recombinant human erythropoietin (rHuEPO) improves autologous blood donation before elective surgery. However, there are other studies indicating that rHuEPO may suppress postoperative endogenous production of erythropoietin and stimulate inflammatory mediator release. Weekly donations generate only a moderate increase in endogenous erythropoietin production. We scheduled patients with cancer to predeposit three units of blood in 2 weeks, with or without rHuEPO therapy. The aim was to determine whether rHuEPO therapy and/or an aggressive donation schedule alter perioperative erythropoietin concentrations and whether rHuEPO therapy leads to the release of the pro‐inflammatory cytokines IL‐6 and IL‐8.

Methods:  Thirty women scheduled for radical hysterectomy and pelvic lymphadenectomy were randomly assigned to either a control group with no rHuEPO therapy or to receive rHuEPO. Three units of whole blood were collected from each patient before the operation. Concentrations of haemoglobin, erythropoietin (s‐EPO) and cytokines (IL‐6 and IL‐8) were repeatedly analyzed before and after the operation.

Results:  During the preoperative donation period, median s‐EPO levels in the control group increased from 7 to 14 IU l−1. There was a great increase in s‐EPO concentrations 1 h postoperatively in the rHuEPO group compared with the control group (P < 0.001). IL‐6 and IL‐8 were not significantly changed after intravenous administration of rHuEPO.

Conclusion:  The use of rHuEPO therapy to optimise autologous blood donation does not influence IL‐6 and IL‐8 release. 1 h postoperatively rHuEPO therapy resulted in elevated s‐EPO concentrations. There was, however, no difference in s‐EPO between the groups from day 1 postoperatively and until the end of the study.
Influences of host volatiles on feeding behaviour of the Japanese pine sawyer, Monochamus alternatus
Authors: Fan J. T. , Sun J. H.
Published: April 2006

Abstract:  Choice and no‐choice feeding assays on the twigs of three host species demonstrated the following feeding preference sequence by Monochamus alternatus: Pinus massoniana > Cedrus deodara > Pinus thunbergii. There were significant differences in the concentrations of α‐pinene, camphene, d‐limonene, β‐phellandrene, longifolene and β‐caryophyllene in volatiles emitted by twigs among the three species. We tested the effects of six monoterpenes (α‐pinene, β‐pinene, 3‐carene, myrcene, limonene and β‐caryophyllene) added to an artificial diet consisting of bark from P. thunbergii on consumption rates by M. alternatus. The addition of α‐pinene at all four concentrations 0.4, 1.2, 3.6 and 10.8 μl/ml resulted in increases of a twofold greater consumption rate than the control at a concentration of 3.6 μl/ml. Limonene inhibited diet consumption at concentrations >0.4 μl/ml. The concentration of α‐pinene in volatiles emitted by twigs was significantly higher for P. massoniana than for P. thunbergii, whereas the reverse was true for limonene. There were no differences for any of the other host components, suggesting that α‐pinene and limonene may play an important role in the adult's selection and acceptance of suitable and unsuitable feed host. Mixed compounds promoted the consumption of artificial diet at a concentration of 0.4 μl/ml, whereas consumption was inhibited at a concentration of 10.8 μl/ml. There were significant linear correlations (β‐pinene: r2 = 0.930, P < 0.05; myrcene: r2 = 0.933, P < 0.05) between the amount of diets consumed and diet concentrations of β‐pinene and myrcene. In conclusion, host volatile terpenes may stimulate or repel M. alternatus depending on terpene concentrations they encounter during initial feeding and then possibly inhibit further feeding activity once concentrations increase to threshold levels.
Interparental Discord and Child Adjustment: Prospective Investigations of Emotional Security as an Explanatory Mechanism
Authors: Cummings E. Mark , Schermerhorn Alice C. , Davies Patrick T. , Goeke‐Morey Marcie C. , Cummings Jennifer S.
Published: April 2006

Advancing the process‐oriented study of links between interparental discord and child adjustment, 2 multimethod prospective tests of emotional security as an explanatory mechanism are reported. On the basis of community samples, with waves spaced 2 years apart, Study 1 (113 boys and 113 girls, ages 9–18) identified emotional security as a mediator in a 2‐wave test, whereas Study 2 (105 boys and 127 girls, ages 5–7) indicated emotional security as an intervening mechanism in a 3‐wave test. Relations between discord and emotional security increased as children moved into adolescence in Study 1. Emotional security was identified as an explanatory mechanism for both internalizing and externalizing problems in children.
Health, Wealth, and Happiness
Authors: Smith Dylan M. , Langa Kenneth M. , Kabeto Mohammed U. , Ubel Peter A.
Published: April 2006

We examined the hypothesis that the relationship between financial status and subjective well-being, typically found to be very small in cross-sectional studies, is moderated by health status. Specifically, we predicted that wealth would buffer well-being after the onset of a disability. Using data from the Health and Retirement Study, a longitudinal study of people at and approaching retirement age, we employed within-subjects analyses to test whether wealth measured prior to the onset of a disability protected participants' well-being from some of the negative effects of a new disability. We found support for this hypothesis: Participants who were above the median in total net worth reported a much smaller decline in well-being after a new disability than did participants who were below the median. We also found some evidence that the buffering effect of wealth faded with time, as below-median participants recovered some of their well-being.
Where tendons and ligaments meet bone: attachment sites (‘entheses’) in relation to exercise and/or mechanical load
Authors: Benjamin M. , Toumi H. , Ralphs J. R. , Bydder G. , Best T. M. , Milz S.
Published: April 2006

Entheses (insertion sites, osteotendinous junctions, osteoligamentous junctions) are sites of stress concentration at the region where tendons and ligaments attach to bone. Consequently, they are commonly subject to overuse injuries (enthesopathies) that are well documented in a number of sports. In this review, we focus on the structure–function correlations of entheses on both the hard and the soft tissue sides of the junction. Particular attention is paid to mechanical factors that influence form and function and thus to exploring the relationship between entheses and exercise. The molecular parameters indicative of adaptation to mechanical stress are evaluated, and the basis on which entheses are classified is explained. The application of the ‘enthesis organ’ concept (a collection of tissues adjacent to the enthesis itself, which jointly serve the common function of stress dissipation) to understanding enthesopathies is considered and novel roles of adipose tissue at entheses are reviewed. A distinction is made between different locations of fat at entheses, and possible functions include space‐filling and proprioception. The basic anchorage role of entheses is considered in detail and comparisons are explored between entheses and other biological ‘anchorage’ sites. The ability of entheses for self‐repair is emphasized and a range of enthesopathies common in sport are reviewed (e.g. tennis elbow, golfer's elbow, jumper's knee, plantar fasciitis and Achilles insertional tendinopathies). Attention is drawn to the degenerative, rather than inflammatory, nature of most enthesopathies in sport. The biomechanical factors contributing to the development of enthesopathies are reviewed and the importance of considering the muscle–tendon–bone unit as a whole is recognized. Bony spur formation is assessed in relation to other changes at entheses which parallel those in osteoarthritic synovial joints.
EFFECT OF SPICES ON GROWTH AND SURVIVAL OF SALMONELLA TYPHIMURIUM DT 104 IN GROUND BEEF STORED AT 4 AND 8C
Authors: UHART MILAGROS , MAKS NICOLE , RAVISHANKAR SADHANA
Published: April 2006

Few studies have addressed the use of spices against pathogens associated with meat. The effects of garlic, ginger and turmeric were evaluated against Salmonella Typhimurium DT 104 that were inoculated either in spice paste or in buffered peptone water (BPW) or in heat‐treated ground beef and stored at 4 and 8C for 10 days. Data from the spice pastes study showed a decrease in Salmonella Typhimurium DT 104 counts, and the greatest reduction (3.39 log) was observed in garlic paste stored at 4C. Garlic in BPW data showed a reduction of 1.5 and 1.0 log in Salmonella Typhimurium counts at 4 and 8C, respectively. Ground beef stored at 4C showed no growth or a slight reduction in growth in samples with spice, while all samples at 8C showed an increase in Salmonella Typhimurium counts. Results show that the spices inhibit or inactivate Salmonella Typhimurium DT 104 when they are in direct contact. However, when spices are added to a complex food system such as ground beef, the inhibitory activity of these spices considerably decreases.