bluuebunny/crossref_metadata_2025 huggingface dataset:
Writing Treatment for Severe Aphasia
Authors: Beeson Pélagie M. , Rising Kindle , Volk Jennifer
Published: April 2006

Writing treatment that involved repeated copying and recall of target words was implemented with 8 individuals with severe aphasia in order to discern the best candidates for the treatment. Four of the 8 participants had strong positive responses to the copy and recall treatment (CART), relearning spellings for 15 targeted words during 10 to 12 weeks of treatment and up to 5 additional words during a month-long homework-based program. Of the 4 other participants, 3 learned the spellings of some target words but failed to reach criterion, and 1 had a poor treatment outcome. Insights regarding possible factors that limited success were gained by examination of individual responses to treatment as well as performance on the pretreatment assessments of semantic, phonological, and orthographic processes. Among the factors associated with success were (a) consistent, accurate completion of daily homework, (b) a relatively preserved semantic system, (c) the ability to discern words from nonwords, and (d) adequately preserved nonverbal visual problem-solving skills. Aphasia severity and minimal pretreatment spelling abilities did not necessarily limit the response to treatment. Participants with positive treatment outcomes demonstrated improved spelling of target words following repeated copying within a single treatment session, and accurately completed daily writing homework. Thus, pretreatment assessment and stimulability within initial treatment sessions provided indications of likely outcome.
Learning New Words II
Authors: Storkel Holly L.
Published: April 2006

Phonotactic probability, a measure of the likelihood of occurrence of a sound sequence, appears to facilitate noun learning (H. L. Storkel, 2001). Nouns and verbs, however, tend to differ in rate of acquisition, indicating that word-learning mechanisms may differ across grammatical class. The purpose of the current study was to examine the effect of phonotactic probability on verb learning. Thirty-four typically developing preschool children participated in a multitrial word-learning task involving nonwords varying in phonotactic probability paired with unfamiliar actions. Multiple measures of word learning were obtained at increasing numbers of exposures. Correct responses were analyzed to examine rate of word learning. Results paralleled those of the previous noun-learning study, with common sound sequences being learned more rapidly than rare sound sequences. The results are interpreted in relation to the effect of distributional regularities on acquisition and the reported discrepancy between noun and verb learning in English.
Effects of Age, Gender, Bolus Volume, Bolus Viscosity, and Gustation on Swallowing Apnea Onset Relative to Lingual Bolus Propulsion Onset in Normal Adults
Authors: Hiss Susan G. , Strauss Monica , Treole Kathleen , Stuart Andrew , Boutilier Susan
Published: April 2006

The purpose of this study was to ascertain the normal relation of swallowing apnea (SA) onset relative to lingual bolus propulsion along with factors that may alter this relation. Forty adults, composed of 10 men and 10 women in each of 2 age groups (i.e., 20–30 and 63–79 years) participated. SA onset was assessed during 5- and 20-ml bolus volumes of water and apple juice across 3 trials. The effects of age, gender, bolus volume, bolus viscosity, and gustation on SA onset relative to lingual bolus propulsion were examined. A significant interaction of Age × Gender × Volume was found. In general, older adults initiated SA onset earlier than young adults, and large boluses elicited an earlier SA onset than small boluses regardless of group. Young men demonstrated significantly later SA onset than the older men for large volumes; this difference was not observed for small volumes, nor was it found between young and older women. SA onset also was assessed during 5-ml bolus volumes of thin apple juice, thick apple juice, and applesauce across three trials. A significant main effect of viscosity was found revealing that SA onset was initiated later as bolus viscosity increased. Thus, the results of this investigation provided data on the relation of SA onset relative to lingual bolus propulsion in individuals with normal swallowing and how this relation changes as a function of age, gender, bolus volume, bolus viscosity, and gustation.
Language Performance in Chronic Schizophrenia
Authors: Meilijson Sara R. , Kasher Asa , Elizur Avner
Published: April 2006

In this study, the authors examined the language of 43 participants with chronic schizophrenia under the basic assumption that a paradigmatic shift is needed in the methodology used to investigate the language of schizophrenia. Thepragmatic protocol(C. Prutting & D. Kirchner, 1987) was chosen as the method of analysis to attain a general profile of pragmatic abilities. The results showed that the participants with schizophrenia exhibited a high degree of inappropriate pragmatic abilities compared to participants with mixed anxiety-depression disorder and participants with hemispheric brain damage, as previously assessed by Prutting and Kirchner. Statistical methods for clustering analysis yielded 5 distinct parameter clusters: Topic, Speech Acts, Turn-Taking, Lexical, and Nonverbal. Group clustering analysis of the 43 participants with schizophrenia produced 3 distinct groups with different profiles: minimal impairment, lexical impairment, and interactional impairment. The results are discussed in terms of theoretical implications in the area of pragmatics, the diagnosis of schizophrenia, and other goals.
Difference in Standard Scores of Adults on the Peabody Picture Vocabulary Test (Revised and Third Edition)
Authors: Pankratz Mary , Morrison Andrea , Plante Elena
Published: April 2006

Differences in the standard scores for the Peabody Picture Vocabulary Test-Revised (PPVT-R; L. M. Dunn & L. M. Dunn, 1981) and the PPVT-Third Edition (PPVT-III; Dunn & Dunn, 1997b) are known to exist for children, with typically higher scores occurring on the PPVT-III. However, these tests are administered into adulthood as well, and score equivalence must be evaluated for this age range. Analysis of data from the PPVT-R and PPVT-III tests from 76 adult participants revealed significant score differences. Participants with poor language skills scored significantly higher on the PPVT-III than on the PPVT-R. The control group showed no significant difference between the PPVT-R and PPVT-III scores. The results suggest that the two tests should not be considered interchangeable.
The Search for Common Ground
Authors: Kohnert Kathryn , Windsor Jennifer
Published: April 2006

Below-average performance on some nonlinguistic tasks often is considered a potential correlate of primary language impairment (LI). If nonlinguistic cognitive processing truly is deficient in children with LI, then measures may be identified that distinguish language learners at risk for LI that are independent of the number and type of languages learned. This study focuses on within- and across-stask performance on 4 basic nonlinguistic processing tasks. The aim was to systematically investigate areas of potential overlap and divergence among 3 groups of linguistically diverse children: English-only speakers with LI, typically developing English-only speakers (EO), and typically developing bilingual Spanish—English speakers (BI). The performance of the 100 8–13-year-old children who took part in J. Windsor and K. Kohnert’s (2004) study was analyzed. Experimental tasks were simple and choice versions of auditory- and visual-detection tasks. Each task included 4 levels of motor difficulty: responfficient or faulty language-processing skills). ding with the preferred and nonpreferred hand and foot. Analyses revealed no significant differences among groups in simple auditory detection. The EO group was significantly faster than the LI group in each of the other 3 tasks. While the same pattern was evident for the BI group, the difference was significant only in choice visual detection. Overall patterns of response latency within and across tasks were qualitatively similar across the 3 groups. Development, indexed here by chronological age, played a significant role in predicting response latencies for children in all 3 groups.
The Efficacy of Treatment for Children With Developmental Speech and Language Delay/Disorder
Authors: Law James , Garrett Zoe , Nye Chad
Published: April 2006

A meta-analysis was carried out of interventions for children with primary developmental speech and language delays/disorders. The data were categorized depending on the control group used in the study (no treatment, general stimulation, or routine speech and language therapy) and were considered in terms of the effects of intervention on expressive and receptive phonology, syntax, and vocabulary. The outcomes used in the analysis were dependent on the aims of the study; only the primary effects of intervention are considered in this review. These were investigated at the level of the target of therapy, measures of overall linguistic development, and broader measures of linguistic functioning taken from parent report or language samples. Thirty-six articles reporting 33 different trials were found. Of these articles, 25 provided sufficient information for use in the meta-analyses; however, only 13 of these, spanning 25 years, were considered to be sufficiently similar to be combined. The results indicated that speech and language therapy might be effective for children with phonological or expressive vocabulary difficulties. There was mixed evidence concerning the effectiveness of intervention for children with expressive syntax difficulties and little evidence available considering the effectiveness of intervention for children with receptive language difficulties. No significant differences were found between interventions administered by trained parents and those administered by clinicians. The review identified longer duration (>8 weeks) of therapy as being a potential factor in good clinical outcomes. A number of gaps in the evidence base are identified.
Oral and Written Story Composition Skills of Children With Language Impairment
Authors: Fey Marc E. , Catts Hugh W. , Proctor-Williams Kerry , Tomblin J. Bruce , Zhang Xuyang
Published: April 2006

In this study 538 children composed 1 oral and 1 written fictional story in both 2nd and 4th grades. Each child represented 1 of 4 diagnostic groups: typical language (TL), specific language impairment (SLI), nonspecific language impairment (NLI), or low nonverbal IQ (LNIQ). The stories of the TL group had more different words, more grammatical complexity, fewer errors, and more overall quality than either language-impaired group at either grade. Stories of the SLI and LNIQ groups were consistently stronger than were those of the NLI group. Kindergarten children with language impairment (LI) whose standardized test performance suggested normalization by 2nd grade also appeared to have recovered in storytelling abilities at that point. By 4th grade, however, these children's stories were less like the children with TL and more like those of children with persistent LI than they had been in 2nd grade. Oral stories were better than written stories in both grades, although the greatest gains from 2nd to 4th grade were generally made on written stories. Girls told stronger stories than did boys at both grades, regardless of group placement. It is concluded that story composition tasks are educationally relevant and should play a significant role in the evaluation of children with developmental LI.
Lexical and Phonological Organization in Children
Authors: Munson Benjamin , Swenson Cyndie L. , Manthei Shayla C.
Published: April 2006

This study examined the structure of children’s mental lexicons through performance on 2 short experimental tasks, 1 in which children repeated familiar monosyllabic real words varying in neighborhood density and 1 in which they repeated CVC nonwords varying in phonotactic probability. Two groups of typically developing children with mean ages of 4;3 (years;months;n=16) and 7;2 (n=15) participated. In the group of younger children, offset-to-onset response latencies were not systematically affected by lexicality, phonotactic probability, or neighborhood density. Onset-to-onset latencies showed an effect of phonotactic probability on nonword repetition. Children in the older group repeated high-density real words with longer latencies than low-density real words. They also repeated high-probability nonwords with shorter latencies than low-probability nonwords. This was true for both the onset-to-onset and offset-to-onset repetition latencies. Children in both age groups repeated vowels embedded in high-probability nonwords with shorter durations than vowels embedded in low-probability nonwords. These findings suggest that lexical competition and phonological facilitation emerge in development and that the rate of development is different for different dependent measures.
Effects of Age and Hearing Loss on Gap Detection and the Precedence Effect
Authors: Lister Jennifer J. , Roberts Richard A.
Published: April 2006

Deficits in temporal resolution and/or the precedence effect may underlie part of the speech understanding difficulties experienced by older listeners in degraded acoustic environments. In a previous investigation, R. Roberts and J. Lister (2004) identified a positive correlation between measures of temporal resolution and the precedence effect, specifically across-channel gap detection (as measured dichotically) and fusion. Across-channel gap detection may also be measured using frequency-disparate markers. Thus, the present investigation was designed to determine if the relation is specific to dichotic gap detection or may generalize to all types of across-channel gap detection. Gap-detection thresholds (GDTs) for fixed-frequency and frequency-disparate markers and lag-burst thresholds (LBTs) were measured for 3 groups of listeners: young with normal hearing sensitivity (YNH), older with normal hearing sensitivity (ONH), and older with sensorineural hearing loss (OIH). Also included were conditions of diotic and dichotic GDT. Largest GDTs were measured for the frequency-disparate markers, whereas largest LBTs were measured for the fixed-frequency markers. ONH and OIH listeners exhibited larger frequency-disparate and dichotic GDTs than YNH listeners. Listener age and hearing loss appeared to influence temporal resolution for frequency-disparate and dichotic stimuli, which is potentially important for the resolution of timing cues in speech. Age and hearing loss did not significantly influence fusion as measured by LBTs. Within each participant group, most GDTs and LBTs were positively, but not significantly, correlated. For all participants combined, across-channel GDTs and LBTs were positively and significantly correlated. This suggests that the 2 tasks may rely on a common across-channel temporal mechanism.
The Haskins Optically Corrected Ultrasound System (HOCUS)
Authors: Whalen D. H. , Iskarous Khalil , Tiede Mark K. , Ostry David J. , Lehnert-LeHouillier Heike , Vatikiotis-Bateson Eric , Hailey Donald S.
Published: April 2006

The tongue is critical in the production of speech, yet its nature has made it difficult to measure. Not only does its ability to attain complex shapes make it difficult to track, it is also largely hidden from view during speech. The present article describes a new combination of optical tracking and ultrasound imaging that allows for a noninvasive, real-time view of most of the tongue surface during running speech. The optical system (Optotrak) tracks the location of external structures in 3-dimensional space using infrared emitting diodes (IREDs). By tracking 3 or more IREDs on the head and a similar number on an ultrasound transceiver, the transduced image of the tongue can be corrected for the motion of both the head and the transceiver and thus be represented relative to the hard structures of the vocal tract. If structural magnetic resonance images of the speaker are available, they may allow the estimation of the location of the rear pharyngeal wall as well. This new technique is contrasted with other currently available options for imaging the tongue. It promises to provide high-quality, relatively low-cost imaging of most of the tongue surface during fairly unconstrained speech.
Young Children's Knowledge of the "Determiner" and "Adjective" Categories
Authors: Kemp Nenagh , Lieven Elena , Tomasello Michael
Published: April 2006

Children's understanding of the grammatical categories of "determiner" and "adjective" was examined using 2 different methodologies. In Experiment 1, children heard novel nouns combined with either
a
or
the
. Few 2-year-olds, but nearly all 3- and 4-year-olds, subsequently produced the novel nouns with a different determiner from the modeled combination. Experiment 2 used a priming methodology. Children age 2, 3, 4, and 6 years repeated descriptions of pictures, before describing target pictures themselves. When the primes consisted of a varied determiner + noun, all age groups produced more determiner + noun descriptions. When the primes consisted of a determiner + adjective + noun, 2-year-olds showed no priming. Three- to 6-year-olds showed item-specific priming, but only 6-year-olds (and to a limited extent 4-year-olds) showed both item-specific and structural priming. These results suggest that children build an understanding of determiners and adjectives gradually, perhaps from individual lexical items, over a number of years, and that pragmatic correctness may be attained particularly late.
Quantifying the Effect of Compression Hearing Aid Release Time on Speech Acoustics and Intelligibility
Authors: Jenstad Lorienne M. , Souza Pamela E.
Published: April 2006

Compression hearing aids have the inherent, and often adjustable, feature of release time from compression. Research to date does not provide a consensus on how to choose or set release time. The current study had 2 purposes: (a) a comprehensive evaluation of the acoustic effects of release time for a single-channel compression system in quiet and (b) an evaluation of the relation between the acoustic changes and speech recognition. The release times under study were 12, 100, and 800 ms. All of the stimuli were VC syllables from the Nonsense Syllable Task spoken by a female talker. The stimuli were processed through a hearing aid simulator at 3 input levels. Two acoustic measures were made on individual syllables: the envelope-difference index and CV ratio. These measurements allowed for quantification of the short-term amplitude characteristics of the speech signal and the changes to these amplitude characteristics caused by compression. The acoustic analyses revealed statistically significant effects among the 3 release times. The size of the effect was dependent on characteristics of the phoneme. Twelve listeners with moderate sensorineural hearing loss were tested for their speech recognition for the same stimuli. Although release time for this single-channel, 3:1 compression ratio system did not directly predict overall intelligibility for these nonsense syllables in quiet, the acoustic measurements reflecting the changes due to release time were significant predictors of phoneme recognition. Increased temporal-envelope distortion was predictive of reduced recognition for some individual phonemes, which is consistent with previous research on the importance of relative amplitude as a cue to syllable recognition for some phonemes.
The Effect of Age at Cochlear Implant Initial Stimulation on Expressive Language Growth in Infants and Toddlers
Authors: Tomblin J. Bruce , Barker Brittan A. , Spencer Linda J. , Zhang Xuyang , Gantz Bruce J.
Published: April 2006

This study examined the growth of expressive language skills in children who received cochlear implants (CIs) in infancy. Repeated language measures were gathered from 29 children who received CIs between 10 and 40 months of age. Both cross-sectional and growth curve analyses were used to assess the relationship between expressive language outcomes and CI experience. A beneficial effect of earlier implantation on expressive language growth was found. Growth curve analysis showed that growth was more rapid in children implanted as infants than those implanted as toddlers. Age at initial stimulation accounted for 14.6% of the variance of the individual differences in expressive language growth rates.
Beyond Capacity Limitations
Authors: Mainela-Arnold Elina , Evans Julia L.
Published: April 2006

Reduced verbal working memory capacity has been proposed as a possible account of language impairments in specific language impairment (SLI). Studies have shown, however, that differences in strength of linguistic representations in the form of word frequency affect list recall and performance on verbal working memory tasks. This suggests that verbal memory capacity and long-term linguistic knowledge may not be distinct constructs. It has been suggested that linguistic representations in SLI are weak in ways that result in a breakdown in language processing on tasks that require manipulation of unfamiliar material. In this study, the effects of word frequency, long-term linguistic knowledge, and serial order position on recall performance in the competing language processing task (CLPT) were investigated in 10 children with SLI and 10 age-matched peers (age 8 years 6 months to 12 years 4 months). The children with SLI recalled significantly fewer target words on the CLPT as compared with their age-matched controls. The SLI group did not differ, however, in their ability to recall target words having high word frequency but were significantly poorer in their ability to recall words on the CLPT having low word frequency. Differences in receptive and expressive language abilities also appeared closely related to performance on the CLPT, suggesting that working memory capacity is not distinct from language knowledge and that degraded linguistic representations may have an effect on performance on verbal working memory span tasks in children with SLI.
Neurophysiological Indices of Speech and Nonspeech Stimulus Processing
Authors: Tampas Joanna W. , Harkrider Ashley W. , Hedrick Mark S.
Published: April 2006

Auditory event-related potentials (mismatch negativity and P300) and behavioral discrimination were measured to synthetically generated consonant-vowel (CV) speech and nonspeech contrasts in 10 young adults with normal auditory systems. Previous research has demonstrated that behavioral and P300 responses reflect a phonetic, categorical level of processing. The aims of the current investigation were (a) to examine whether the mismatch negativity (MMN) response is also influenced by the phonetic characteristics of a stimulus or if it reflects purely an acoustic level of processing and (b) to expand our understanding of the neurophysiology underlying categorical perception, a phenomenon crucial in the processing of speech. The CVs were 2 within-category stimuli and the nonspeech stimuli were 2 glides whose frequency ramps matched the formant transitions of the CV stimuli. Listeners exhibited better behavioral discrimination to the nonspeech versus speech stimuli in same/different and oddball behavioral paradigms. MMN responses were elicited by the nonspeech stimuli, but absent to CV speech stimuli. Larger amplitude and earlier P300s were elicited by the nonspeech stimuli, while smaller and longer latency P300s were elicited by the speech stimulus contrast. Results suggest that the 2 types of stimuli were processed differently when measured behaviorally, with MMN, or P300. The better discrimination and clearer neurophysiological representation of the frequency glide, nonspeech stimuli versus the CV speech stimuli of analogous acoustic content support (a) categorical perception representation at the level of the MMN generators and (b) parallel processing of acoustic (sensory) and phonetic (categorical) information at the level of the MMN generators.
Word Learning by Preschoolers With Specific Language Impairment
Authors: Gray Shelley
Published: April 2006

Purpose:
This study investigated whether phonological or semantic encoding cues promoted better word learning for children with specific language impairment (SLI) and whether this treatment differentially affected children with SLI and normal language (NL).

Method:
Twenty-four preschoolers ages 4;0 (years;months) to 5;11 with SLI and 24 age- and gender-matched children with NL participated. The between-group factor was language group (NL, SLI) and within-group factors were language modality (comprehension, recognition, production) and treatment condition (phonological, semantic). Word learning was assessed during fast mapping, word learning, and posttesting with trials to criterion calculated for the number of words learned. A drawing task assessed the change in semantic representation of words.

Results:
The SLI group comprehended more words in the semantic condition and produced more words in the phonological condition, but the NL group performed similarly in both. The NL group required significantly fewer trials than the SLI group to comprehend words in the semantic and phonological conditions and to produce words in the semantic condition, but between-group differences for production were not significant for the phonological condition.

Conclusions:
The results suggest that preschoolers with SLI may benefit from cues that highlight the phonological or semantic properties of words but that different cues may aid different aspects of word learning.
General equation for the determination of the crystallite size La of nanographite by Raman spectroscopy
Authors: Cançado L. G. , Takai K. , Enoki T. , Endo M. , Kim Y. A. , Mizusaki H. , Jorio A. , Coelho L. N. , Magalhães-Paniago R. , Pimenta M. A.
Published: April 2006

This work presents a systematic study of the ratio between the integrated intensities of the disorder-induced D and G Raman bands (ID∕IG) in nanographite samples with different crystallite sizes (La) and using different excitation laser energies. The crystallite size La of the nanographite samples was obtained both by x-ray diffraction using synchrotron radiation and directly from scanning tunneling microscopy images. A general equation for the determination of La using any laser energy in the visible range is obtained. Moreover, it is shown that ID∕IG is inversely proportional to the fourth power of the laser energy used in the experiment.
Toward understanding the genetics of alcohol drinking through transcriptome meta-analysis
Authors: Mulligan Megan K. , Ponomarev Igor , Hitzemann Robert J. , Belknap John K. , Tabakoff Boris , Harris R. Adron , Crabbe John C. , Blednov Yuri A. , Grahame Nicholas J. , Phillips Tamara J. , Finn Deborah A. , Hoffman Paula L. , Iyer Vishwanath R. , Koob George F. , Bergeson Susan E.
Published: April 2006

Much evidence from studies in humans and animals supports the hypothesis that alcohol addiction is a complex disease with both hereditary and environmental influences. Molecular determinants of excessive alcohol consumption are difficult to study in humans. However, several rodent models show a high or low degree of alcohol preference, which provides a unique opportunity to approach the molecular complexities underlying the genetic predisposition to drink alcohol. Microarray analyses of brain gene expression in three selected lines, and six isogenic strains of mice known to differ markedly in voluntary alcohol consumption provided >4.5 million data points for a meta-analysis. A total of 107 arrays were obtained and arranged into six experimental data sets, allowing the identification of 3,800 unique genes significantly and consistently changed between all models of high or low amounts of alcohol consumption. Several functional groups, including mitogen-activated protein kinase signaling and transcription regulation pathways, were found to be significantly overrepresented and may play an important role in establishing a high level of voluntary alcohol drinking in these mouse models. Data from the general meta-analysis was further filtered by a congenic strain microarray set, from which cis-regulated candidate genes for an alcohol preference quantitative trait locus on chromosome 9 were identified:
Arhgef12
,
Carm1
,
Cryab
,
Cox5a
,
Dlat
,
Fxyd6
,
Limd1
,
Nicn1
,
Nmnat3
,
Pknox2
,
Rbp1
,
Sc5d
,
Scn4b
,
Tcf12
,
Vps11
, and
Zfp291
and four ESTs. The present study demonstrates the use of (
i
) a microarray meta-analysis to analyze a behavioral phenotype (in this case, alcohol preference) and (
ii
) a congenic strain for identification of cis regulation.
Crystal structures of γ-glutamyltranspeptidase from
Escherichia coli
, a key enzyme in glutathione metabolism, and its reaction intermediate
Authors: Okada Toshihiro , Suzuki Hideyuki , Wada Kei , Kumagai Hidehiko , Fukuyama Keiichi
Published: April 2006

γ-Glutamyltranspeptidase (GGT) is a heterodimic enzyme that is generated from the precursor protein through posttranslational processing and catalyzes the hydrolysis of γ-glutamyl bonds in γ-glutamyl compounds such as glutathione and/or the transfer of the γ-glutamyl group to other amino acids and peptides. We have determined the crystal structure of GGT from
Escherichia coli
K-12 at 1.95 Å resolution. GGT has a stacked αββα fold comprising the large and small subunits, similar to the folds seen in members of the N-terminal nucleophile hydrolase superfamily. The active site Thr-391, the N-terminal residue of the small subunit, is located in the groove, from which the pocket for γ-glutamyl moiety binding follows. We have further determined the structure of the γ-glutamyl-enzyme intermediate trapped by flash cooling the GGT crystal soaked in glutathione solution and the structure of GGT in complex with
l
-glutamate. These structures revealed how the γ-glutamyl moiety and
l
-glutamate are recognized by the enzyme. A water molecule was seen on the carbonyl carbon of the γ-glutamyl-Thr-391 Oγ bond in the intermediate that is to be hydrolyzed. Notably the residues essential for GGT activity (Arg-114, Asp-433, Ser-462, and Ser-463 in
E. coli
GGT) shown by site-directed mutagenesis of human GGT are all involved in the binding of the γ-glutamyl moiety. The structure of
E. coli
GGT presented here, together with sequence alignment of GGTs, may be applicable to interpret the biochemical and genetic data of other GGTs.
An endangered oasis of aquatic microbial biodiversity in the Chihuahuan desert
Authors: Souza Valeria , Espinosa-Asuar Laura , Escalante Ana E. , Eguiarte Luis E. , Farmer Jack , Forney Larry , Lloret Lourdes , Rodríguez-Martínez Juan M. , Soberón Xavier , Dirzo Rodolfo , Elser James J.
Published: April 2006

The Cuatro Cienegas basin in the Chihuahuan desert is a system of springs, streams, and pools. These ecosystems support >70 endemic species and abundant living stromatolites and other microbial communities, representing a desert oasis of high biodiversity. Here, we combine data from molecular microbiology and geology to document the microbial biodiversity of this unique environment. Ten water samples from locations within the Cuatro Cienegas basin and two neighboring valleys as well as three samples of wet sediments were analyzed. The phylogeny of prokaryotic populations in the samples was determined by characterizing cultured organisms and by PCR amplification and sequencing of 16S rRNA genes from total community DNA. The composition of microbial communities was also assessed by determining profiles of terminal restriction site polymorphisms of 16S rRNA genes in total community DNA. There were 250 different phylotypes among the 350 cultivated strains. Ninety-eight partial 16S rRNA gene sequences were obtained and classified. The clones represented 38 unique phylotypes from ten major lineages of Bacteria and one of Archaea. Unexpectedly, 50% of the phylotypes were most closely related to marine taxa, even though these environments have not been in contact with the ocean for tens of millions of years. Furthermore, terminal restriction site polymorphism profiles and geological data suggest that the aquatic ecosystems of Cuatro Cienegas are hydrologically interconnected with adjacent valleys recently targeted for agricultural intensification. The findings underscore the conservation value of desert aquatic ecosystems and the urgent need for study and preservation of freshwater microbial communities.
Neuregulin 1 transcripts are differentially expressed in schizophrenia and regulated by 5′ SNPs associated with the disease
Authors: Law Amanda J. , Lipska Barbara K. , Weickert Cynthia Shannon , Hyde Thomas M. , Straub Richard E. , Hashimoto Ryota , Harrison Paul J. , Kleinman Joel E. , Weinberger Daniel R.
Published: April 2006

Genetic variation in neuregulin 1 (
NRG1
) is associated with schizophrenia. The disease-associated SNPs are noncoding, and their functional implications remain unknown. We hypothesized that differential expression of the
NRG1
gene explains its association to the disease. We examined four of the disease-associated SNPs that make up the original risk haplotype in the 5′ upstream region of the gene for their effects on mRNA abundance of
NRG1
types I–IV in human postmortem hippocampus. Diagnostic comparisons revealed a 34% increase in type I mRNA in schizophrenia and an interaction of diagnosis and genotype (SNP8NRG221132) on this transcript. Of potentially greater interest, a single SNP within the risk haplotype (SNP8NRG243177) and a 22-kb block of this core haplotype are associated with mRNA expression for the novel type IV isoform in patients and controls. Bioinformatic promoter analyses indicate that both SNPs lead to a gain/loss of putative binding sites for three transcription factors, serum response factor, myelin transcription factor-1, and High Mobility Group Box Protein-1. These data implicate variation in isoform expression as a molecular mechanism for the genetic association of
NRG1
with schizophrenia.
Fas-positive T cells regulate the resolution of airway inflammation in a murine model of asthma
Authors: Tong Jiankun , Bandulwala Hozefa S. , Clay Bryan S. , Anders Robert A. , Shilling Rebecca A. , Balachandran Diwakar D. , Chen Bohao , Weinstock Joel V. , Solway Julian , Hamann Kimm J. , Sperling Anne I.
Published: April 2006

Persistent airway inflammation, mucus production, and airway hyperreactivity are the major contributors to the frequency and severity of asthma. Why lung inflammation persists in asthmatics remains unclear. It has been proposed that Fas-mediated apoptosis of inflammatory cells is a fundamental mechanism involved in the resolution of eosinophilic airway inflammation. Because infiltrating eosinophils are highly sensitive to Fas-mediated apoptosis, it has been presumed that direct ligation of Fas on eosinophils is involved. Here, we utilize adoptive transfers of T cells to demonstrate that the delayed resolution of eosinophilia in Fas-deficient mice is a downstream effect of Fas deficiency on T cells, not eosinophils. Interestingly, the mice that received Fas-deficient T cells, but not the controls, developed a persistent phase of inflammation that failed to resolve even 6 wk after the last challenge. This persistent phase correlated with decreased interferon (IFN)γ production by Fas-deficient T cells and could be reproduced with adoptive transfer of IFNγ-deficient T cells. These data demonstrate that Fas deficiency on T cells is sufficient for the development of long-term allergic airway disease in mice and implies that deregulation of death receptors such as Fas on human T cells could be an important factor in the development and/or chronic nature of asthma.
Lessons Learned From a Norovirus Outbreak in a Locked Pediatric Inpatient Psychiatric Unit
Authors: Weber David J. , Sickbert-Bennett Emily E. , Vinjé Jan , Brown Vickie M. , MacFarquhar Jennifer K. , Engel Jeffrey P. , Rutala William A.
Published: April 2006

We report an outbreak of norovirus in a locked pediatric inpatient psychiatric unit with attack rates of 75% among 4 patients and 26% among 38 staff. Factors contributing to the outbreak included environmental contamination, close staff-patient contact including sharing meals, and inability to confine the index patient with the use of contact precautions.
The reliability of laryngoscope lights
Authors: Howes B. W.
Published: April 2006

The aim of this study is to compare the brightness of laryngoscope light between instruments, and the variability within the same instrument. A secondary aim is to compare the light from a reusable laryngoscope with a single use design. Testing equipment was constructed which provided a qualitative measure of light output from laryngoscopes. Anaesthetists assessed the minimum acceptable brightness for intubation using the intubating mannikin and a variable brightness laryngoscope. Laryngoscopes in anaesthetic rooms around the hospital were then tested repeatedly, and the results were compared to the anaesthetists' opinions. There was considerable intersubject and intrasubject variation in the reusable design, often failing to satisfy the minimum brightness. The single use blades were found to be brighter and more reliable than reusable blades.
Fibrinolytic dysfunction in insulin‐resistant women with previous gestational diabetes
Authors: Farhan S. , Winzer C. , Tura A. , Quehenberger P. , Bieglmaier C. , Wagner O. F. , Huber K. , Waldhäusl W. , Pacini G. , Kautzky‐Willer A.
Published: April 2006

Background  Women with a history of gestational diabetes (p‐GDM) are at increased risk of developing type 2 diabetes mellitus (DM2) later in life, and therefore at increased risk for future cardiovascular disease.

Materials and methods  Three months after delivery we investigated the plasma levels of plasminogen activator inhibitor type 1 (PAI‐1), tissue plasminogen activator (t‐PA), fibrinogen and von Willebrand factor (vWF) in 74 women with p‐GDM and 20 healthy females with normal glucose tolerance during and after pregnancy, as well as the relation of fibrinolytic parameters to insulin resistance and glycaemic control. All women underwent an oral (OGTT) as well as an intravenous glucose tolerance test (FSIGT). Mathematical model analysis disclosed that 50% (n = 37 each) of the p‐GDM subjects had normal (NIS) or impaired (IIS) insulin sensitivity. Parameters of interest were determined using commercially available test systems.

Results  Women with p‐GDM and IIS had significantly increased body fat mass (BFM) (P ≤ 0·001) compared with women with p‐GDM and NIS and controls, whereas the waist to hip ratio (WHR) was similar in both p‐GDM groups but was higher compared with the controls (P ≤ 0·001). Mean PAI‐1 and t‐PA as well as fasting and stimulated plasma concentrations of proinsulin, C‐peptide and insulin were elevated, whereas the disposition index was lower in women with p‐GDM and IIS compared with women with p‐GDM and NIS and the controls (P < 0·001). Plasma levels of fibrinogen and vWF did not differ between the groups. Obese women with IIS had higher PAI‐1 levels than lean women with IIS (P ≤ 0·001). PAI‐1 inversely correlated with the insulin sensitivity index (SI) but only in women with IIS (P < 0·0001). On regression analysis, only fasting proinsulin and WHR remained significant independent predictors of PAI‐1 elevation in IIS (P ≤ 0·0001 and P ≤ 0·001). The PAI‐1/SI ratio was elevated in women with IIS independently of their glucose tolerance status (P < 0·001 vs. NIS and controls).

Conclusions  Plasminogen activator inhibitor type 1 is elevated in p‐GDM women with IIS and depends on plasma proinsulin and abdominal obesity. An increase of the PAI‐1/SI ratio further characterizes obese insulin‐resistant p‐GDM women who may be at risk for diabetes and angiopathy.
Advanced nursing practice: policy, education and role development
Authors: Furlong Eileen , Smith Rita
Published: April 2006

Aims and objectives. This paper aims to explore the critical elements of advanced nursing practice in relation to policy, education and role development in order to highlight an optimal structure for clinical practice.

Background. The evolution of advanced nursing practice has been influenced by changes in healthcare delivery, financial constraints and consumer demand. However, there has been wide divergence and variations in the emergence of the advanced nurse practitioner role. For the successful development and implementation of the role, policy, educational and regulatory standards are required.

Conclusion. The paper highlights the value of a policy to guide the development of advanced nursing practice. Educational curricula need to be flexible and visionary to prepare the advanced nurse practitioner for practice. The core concepts for the advanced nursing practice role are: autonomy in clinical practice, pioneering professional and clinical leadership, expert practitioner and researcher. To achieve these core concepts the advanced nurse practitioner must develop advanced theoretical and clinical skills, meet the needs of the client, family and the community.

Relevance to clinical practice. In a rapidly changing people‐centred healthcare environment the advanced nurse practitioner can make an important contribution to healthcare delivery. The challenges ahead are many, as the advanced nurse practitioner requires policy and appropriate educational preparation to practice at advanced level. This will enable the advanced practitioner articulate the role, to provide expert client care and to quantify their contribution to health care in outcomes research.
Behaviour of male European corn borer, Ostrinia nubilalis Hübner (Lep.; Crambidae) towards pheromone‐baited delta traps, bucket traps and wire mesh cone traps
Authors: Pélozuelo Laurent , Frérot Brigitte
Published: April 2006

Abstract:  Pheromone‐baited traps are used to monitor the flight of European corn borer (ECB; Ostrinia nubilalis). Traps of various designs are available: bucket traps, delta sticky traps and wire mesh cone traps. However, these traps are not all equally efficient and little is known about the reasons for this difference in efficiency. We investigated the behaviour of ECB males towards bucket traps and delta traps by means of observation in a wind tunnel. We also carried out observations and capture trials with delta traps and wire mesh cone traps in field conditions. Our laboratory studies showed that ECB males were not optimally attracted and were poorly captured by a pheromone baited bucket trap. Furthermore, they were shown to readily enter delta traps in the wind tunnel but were caught after more than three passages through this trap. Field studies showed that wire mesh cone traps captured approximately six times more ECB males than delta traps. Observation of the behaviour of ECB males showed that this difference was due to more efficient moth capture rather than greater attraction of the moth. In total, 31.5% of the 219 males observed close to wire mesh cone traps were caught, vs. 2.5% of the 520 males observed close to delta traps. This greater efficiency is due to a better capture rate of the attracted males by wire mesh cone traps than by delta traps.
Waterlogging duration: Interspecific comparison ofLeptospermum scoparium(Forst et Forst.f.), Acacia melanoxylon(R. Br.), Nothofagus cunninghamii(Hook.) andEucalyptus obliqua(L’Herit)
Authors: PRYOR REBECCA J. , DAVIDSON NEIL J. , CLOSE DUGALD C.
Published: April 2006

Abstract The effect of the duration of waterlogging on the pre‐dawn water potential, gas exchange, biomass accumulation and survival was investigated on four species,Leptospermum scoparium(Forst et Forst.f.),Acacia melanoxylon(R. Br.), Eucalyptus obliqua(L’Herit) andNothofagus cunninghamii(Hook.). These species co‐occur, but are restricted to particular microsites. The three waterlogging treatments applied to potted seedlings were: four cycles of 15 days, two cycles of 30 days or one 60‐day cycle, followed by an equal period in freely drained conditions. Water potential, gas exchange, biomass accumulation and survival were not significantly affected by the duration of waterlogging inL. scopariumorA. melanoxylon.With increased waterlogging duration,N. cunninghamiihad progressively decreased survival, had less biomass accumulation in all waterlogging treatments and more negative water potential after the 60‐day waterlogging cycle. In contrast,E. obliquahad low survival under the 15‐day waterlogging cycle treatment, although survival, biomass accumulation and maximum net photosynthesis were decreased by all waterlogging cycle treatments. Water potential was significantly lower (more negative) inE. obliquathan other species after the 30‐ and 60‐day waterlogging cycle treatments only. When exposed to oxygen deficit in hypoxic nutrient culture for 5 days,L. scopariumhad 100% survival and maximum net photosynthesis was not affected.Acacia melanoxylonhad 80% survival and decreased photosynthesis from 2 days of exposure onwards.Nothofagus cunninghamiiandE. obliquahad 70% and 30% survival, respectively, and their photosynthesis was significantly depressed after 1 day of exposure to hypoxic conditions. Relative tolerance of the species examined to waterlogging and hypoxia was consistent with adaptation to conditions of seasonal variation in water table height and soil oxygenation concentration observed at the microsites occupied by the respective species. The results indicate that duration of waterlogging may be a major determinant in the microsite distribution of the co‐occurring species investigated.
Untangling the Links of Parental Responsiveness to Distress and Warmth to Child Outcomes
Authors: Davidov Maayan , Grusec Joan E.
Published: April 2006

This study demonstrated separate linkages between 2 features of positive parenting—responsiveness to distress and warmth—and different aspects of children's socio‐emotional functioning, in a sample of 106 children (6–8 years old). As expected, mothers' and fathers' responsiveness to distress, but not warmth, predicted better negative affect regulation. Maternal responsiveness to distress also predicted children's empathy and prosocial responding. Maternal warmth, but not responsiveness to distress, was linked to better regulation of positive affect and (in boys only) to greater peer acceptance. Additionally, negative affect regulation mediated between maternal responsiveness to distress and children's empathic responding. Positive affect regulation mediated between maternal warmth and boys' peer acceptance. The findings support a differentiated approach to positive parenting.
Contemporaneous and Longitudinal Associations Between Social Behavior and Literacy Achievement in a Sample of Low‐Income Elementary School Children
Authors: Miles Sarah B. , Stipek Deborah
Published: April 2006

This study investigates associations between social skills (aggression and prosocial behavior) and literacy achievement in a sample of low‐income children (between 4 and 6 years old when the study began) during elementary school. Results revealed consistent associations between social skills and literacy achievement in the first, third, and fifth grades, but the patterns of the associations were different for aggression and prosocial behavior. While the strength of the association between aggression and literacy achievement increased over the elementary grades, the association between prosocial behavior and literacy achievement decreased. In addition, path analyses revealed that poor literacy achievement in the first and third grades predicted relatively high aggressive behavior in the third and fifth grades, respectively.