bluuebunny/crossref_metadata_2025_split huggingface dataset:
Psychological well‐being of staff working with people who have challenging behaviour
Authors: Jenkins R. , Rose J. , Lovell C. 
Published: February 2007

AbstractThe present survey explored stress in direct‐care staff working with people who have learning disabilities and challenging behaviour. A total of 78 (82.7% response rate) staff working in 14 small community houses participated. Houses were selected on the basis of ‘expert’ (Head of Psychology Services) knowledge of houses where residents were known to display challenging behaviour and houses where there was no known history of challenging behaviour. Residents were assessed by key workers for adaptive behaviour, challenging behaviour and mental health using partially validated questionnaires. Staff completed self‐report questionnaires on job demands, anxiety and depression, staff support, and information on the presence/absence of challenging behaviour in their home. Staff working in houses with residents who showed challenging behaviour were significantly more anxious than staff working in houses with no challenging behaviour; they also reported feeling significantly less supported, were less clear about the identification of risk situations and had lower job satisfaction. No differences were found on measures of job demands and depression. Regression analyses exploring the relationships between these variables are discussed along with the implications of the findings.
Intellectual and adaptive behaviour functioning in pantothenate kinase‐associated neurodegeneration
Authors: Freeman K. , Gregory A. , Turner A. , Blasco P. , Hogarth P. , Hayflick S. 
Published: February 2007

AbstractBackground  Pantothenate kinase‐associated neurodegeneration (PKAN), an extremely rare autosomal recessive disorder resulting in iron accumulation in the brain, has a diverse phenotypic expression. Based on limited case studies of one or two patients, intellectual impairment is considered part of PKAN. Investigations of cognitive functioning have utilized specific neuropsychological tests, without attention to general intellectual skills or adaptive behaviour.Methods  Sixteen individuals with PKAN completed measures of global intellectual functioning, and participants or care providers completed measures of adaptive behaviour skills and day‐to‐day functional limitations. Clinicians provided global ratings of condition severity.Results  Testing with standardized measures documented varied phenotypic expression, with general cognitive skills and adaptive behaviour ranging from high average to well below average. Age of disease onset correlated with measures of intellectual functioning, adaptive functioning and disease severity.Conclusions  Findings support previously described clinical impressions of varied cognitive impairment and the association between age of onset and impairment. Further, they add important information regarding the natural history of the disease and suggest assessment strategies for use in treatment trials.
Age‐related change in the association between a polymorphism in the PER3 gene and preferred timing of sleep and waking activities
Authors: JONES KAY H. S. , ELLIS JASON , VON SCHANTZ MALCOLM , SKENE DEBRA J. , DIJK DERK‐JAN , ARCHER SIMON N. 
Published: February 2007

SummaryThe objective of this study was to investigate the effect of age on the association between preferred timing of sleep and waking activities and a coding‐region variable number tandem repeat (VNTR) polymorphism in the clock gene PER3. We have previously reported this polymorphism to associate with diurnal preference and delayed sleep phase syndrome (DSPS). Participants (n = 1590; 707 males and 883 females) completed the Horne–Östberg (HÖ) questionnaire for diurnal preference and provided a DNA sample. Overall HÖ scores were plotted against age. The 5% extremes and intermediates were selected for genotyping. Frequencies of the PER3 4‐ and 5‐repeat alleles were examined in separate age groups (18–29, 30–39, 40–49 and 50+ years of age). The 4‐repeat allele was significantly more frequent in evening types, and the 5‐repeat allele more frequent in morning types (Fisher's exact test, P = 0.016). Analysis in the four age groupings revealed that the strength of this association attenuated with age and was significant only in the youngest group (18–29 years). These results extend our previous finding of an association between the PER3 VNTR and diurnal preference. They also demonstrate that diurnal preference in young people is more closely associated with this polymorphism than it is in other age groups.
Stability of genetic influence on morningness–eveningness: a cross‐sectional examination of South Korean twins from preadolescence to young adulthood
Authors: HUR YOON‐MI 
Published: February 2007

AbstractA cross‐sectional twin design was used to study the developmental nature of genetic and environmental influences on morningness–eveningness (M–E). A total of 977 South Korean twin pairs aged 9–23 years completed 13 items of a Korean version of the Composite Scale through the telephone interview. The total sample was split into three age groups: preadolescents, adolescents, and young adults. Twin correlations did not vary significantly with age, suggesting that genetic influences on M–E are stable throughout the developmental span. Results of model‐fitting analyses indicated that genetic and environmental factors explained, respectively, 45% and 55% of the variance in all three age groups. Environmental factors were primarily those factors that twins did not share as a consequence of their common rearing; family environmental factors in M–E were consistently near zero in all three age groups. The present study is the first to demonstrate genetic influences on M–E in preadolescent children as young as 9 years old. In spite of differences in culture and frequencies of genes between South Koreans and Caucasians, genetic and environmental influences on M–E found in the present sample were remarkably similar to those reported by previous studies on the basis of late adolescent and adult Caucasian twins.
The dynamics of neurobehavioural recovery following sleep loss
Authors: LAMOND NICOLE , JAY SARAH M. , DORRIAN JILLIAN , FERGUSON SALLY A. , JONES CHRISTOPHER , DAWSON DREW 
Published: February 2007

SummaryRate of recovery of daytime performance and sleepiness following moderate and severe sleep deprivation (SD) was examined when recovery opportunity was either augmented or restricted. Thirty healthy non‐smokers, aged 18–33 years, participated in one of three conditions: moderate SD with augmented (9‐h) recovery opportunities, moderate SD with restricted (6‐h) recovery opportunities, or severe SD with augmented recovery opportunities. Each participant attended the laboratory for 8–9 consecutive nights: an adaptation and baseline night (23:00–08:00 hours), one or two night(s) of wakefulness, and five consecutive recovery sleep opportunities (23:00–08:00 hours or 02:00–08:00 hours). On each experimental day, psychomotor vigilance performance (PVT) and subjective sleepiness (SSS) were assessed at two‐hourly intervals, and MSLTs were performed at 1000h. PSG data was collected for each sleep period. For all groups, PVT performance significantly deteriorated during the period of wakefulness, and sleepiness significantly increased. Significant differences were observed between the groups during the recovery phase. Following moderate SD, response speed, lapses and SSS returned to baseline after one 9‐h sleep opportunity, while sleep latencies required two 9‐h opportunities. When the recovery opportunity was restricted to six hours, neither PVT performance nor sleepiness recovered, but stabilised at below‐baseline levels. Following severe SD, sleepiness recovered after one (SSS) or two (physiological) 9‐h sleep opportunities, however PVT performance remained significantly below baseline for the entire recovery period. These results suggest that the mechanisms underlying the recovery process may be more complicated than previously thought, and that we may have underestimated the impact of sleep loss and/or the restorative value of subsequent sleep.
Maturation of the initial ventilatory response to hypoxia in sleeping infants
Authors: RICHARDSON HEIDI L. , PARSLOW PETER M. , WALKER ADRIAN M. , HARDING RICHARD , HORNE ROSEMARY S. C. 
Published: February 2007

SummaryIn infants most previous studies of the hypoxic ventilatory response (HVR) have been conducted only during quiet sleep (QS) and arousal responses have not been considered. Our aim was to quantify the maturation of the HVR in term infants during both active sleep (AS) and QS over the first 6 months of life. Daytime polysomnography was performed on 15 healthy term infants at 2–5 weeks, 2–3 and 5–6 months after birth and infants were challenged with hypoxia (15% O2, balance N2). Tests in AS always resulted in arousal; in QS tests infants either aroused or did not arouse. A biphasic HVR was observed in non arousing tests at all three ages studied. The fall in SpO2was more rapid in arousal tests at all three ages. At 2–5 weeks, in non‐arousing QS tests, there was a greater fall in respiratory frequency (f) despite a smaller fall in SpO2compared with 2–3 and 5–6 months. When infants aroused there was no difference in the HVR between sleep states or with postnatal age. However, when infants failed to arouse from QS, arterial desaturation was less in the younger infants despite a poorer HVR. We suggest that arousal in response to hypoxia, particularly in AS, is a vital survival mechanism throughout the first 6 months of life.
Daytime sleepiness, exercise, and physical function in older adults
Authors: CHASENS EILEEN R. , SEREIKA SUSAN M. , WEAVER TERRI E. , UMLAUF MARY GRACE 
Published: February 2007

SummaryThe purpose of this study was to describe the association between sleepiness, exercise, and physical function in older adults, testing the hypothesis that sleepiness predicts decreased exercise and impaired physical function in this population. We performed a secondary analysis of data from the National Sleep Foundation's Sleep in America Poll, comparing frequency of exercise and ability to perform functional tasks between sleepy and non‐sleepy subjects. Trained interviewers administered a scripted telephone survey. Participants (n = 1506) were community‐dwelling older Americans (55–84 years) randomly chosen from geographically representative households with listed telephone numbers. Sleepiness ‘so severe that it interferes with daytime activity’ was dichotomized as ‘daily/frequently’ or ‘never/rare’. Exercise frequency was scored 1–4 (‘less than once a week’ to ‘more than five times a week’). Responses to five questions (walk 0.5 mile, climb stairs, push/pull heavy object, stoop/crouch/or kneel, write, handle small objects), rated 1–5 (‘no difficulty’ to ‘unable to do’), were summed; a mean score of ≥2.5 was considered impaired physical function. Daytime sleepiness predicted low exercise frequency while controlling for age and body mass index (BMI) (OR = 1.40, 95% CI 1.031–1.897, P = 0.031). Frequent daytime sleepiness predicted impaired physical function (OR = 2.76, 95%CI = 0.237–0.553, P = 0.001) after controlling for age, BMI, income and number of co‐morbid conditions. The conclusion was that daytime sleepiness in older adults is associated with physical functional impairments and decreased exercise frequency. The findings suggest that sleepiness in older adults is not benign but has implications for continued physical decline and warrants attention.
Detecting shifts of transmission areas in avian blood parasites — a phylogenetic approach
Authors: HELLGREN OLOF , WALDENSTRÖM JONAS , PERÉZ‐TRIS JAVIER , SZÖLL ESZTER , SI Ö , HASSELQUIST DENNIS , KRIZANAUSKIENE ASTA , OTTOSSON ULF , BENSCH STAFFAN 
Published: February 2007

AbstractWe investigated the degree of geographical shifts of transmission areas of vector‐borne avian blood parasites (Plasmodium,HaemoproteusandLeucocytozoon) over ecological and evolutionary timescales. Of 259 different parasite lineages obtained from 5886 screened birds sampled in Europe and Africa, only two lineages were confirmed to have current transmission in resident bird species in both geographical areas. We used a phylogenetic approach to show that parasites belonging to the generaHaemoproteusandLeucocytozoonrarely change transmission area and that these parasites are restricted to one resident bird fauna over a long evolutionary time span and are not freely spread between the continents with the help of migratory birds. Lineages of the genusPlasmodiumseem more freely spread between the continents. We suggest that such a reduced transmission barrier ofPlasmodiumparasites is caused by their higher tendency to infect migratory bird species, which might facilitate shifting of transmission area. Although vector‐borne parasites of these genera apparently can shift between a tropical and a temperate transmission area and these areas are linked with an immense amount of annual bird migration, our data suggest that novel introductions of these parasites into resident bird faunas are rather rare evolutionary events.
Phylogeography of the rare Balkan endemic Martino's vole, Dinaromys bogdanovi, reveals strong differentiation within the western Balkan Peninsula
Authors: KRYSTUFEK BORIS , BUZAN ELENA V. , HUTCHINSON WILLIAM F. , HÄNFLING BERND 
Published: February 2007

AbstractThe spatial genetic structure of Martino's vole, a rare palaeoendemic species of the western Balkans, was investigated using DNA isolated from archived museum samples. The study was based on partial sequencing (555 bp) of the mitochondrial cytochrome b gene for 63 specimens from 20 different localities throughout the species’ range. Three highly divergent allopatric phylogenetic lineages (Northwestern, Central and Southeastern) were recognized among 47 haplotypes, suggesting three independent glacial differentiation centres within the western Balkans. The Northwestern lineage, which showed the highest divergence from all other samples (mean sequence divergence of 6.64% ± 1.10), comprised samples collected from northwest of the Neretva River in Croatia, western Bosnia and Herzegovina. The Central and Southeastern lineages were separated by an average sequence divergence of 2.95% ± 0.66 and were geographically divided by the Drim River (the Kosovo Basin in Serbia). Overall, haplotype diversity decreased from the Northwestern lineage to the Central and subsequently the Southeastern lineage, in a geographical pattern consistent with a stepping stone colonization. The observed distribution indicates a gradual southerly expansion with subsequent allopatry across the Neretva River and Drim River approximately 1 and 0.3 million years ago, respectively. Such a scenario is concordant with palaeontological evidence. Several highly divergent sublineages within the Northwestern and Central lineages showed no significant geographical structuring, suggesting secondary contact of allopatrically evolved lineages. We hypothesize that the topographical complexity of the Balkans promoted allopatry and isolation on a small geographical scale during interglacial periods, with secondary contact during glacial maxima. Furthermore, the three main lineages should be regarded as evolutionary significant units with important implications for conservation. Ecological data show that the Northwestern lineage in particular fulfils all criteria for a highly endangered, evolutionarily significant unit.
Introgression in the genusSalmovia allotriploids
Authors: CASTILLO A. G. F. , BEALL E. , MORAN P. , MARTINEZ J. L. , AYLLON F. , GARCIA‐VAZQUEZ E. 
Published: February 2007

AbstractHybridization between sympatric species is not uncommon in the wild. Wild allotriploids (individuals with two chromosome sets from a species + one chromosome set from another species) are generally the result of a backcross between interspecific hybrids that produce unreduced gametes and one of the parental species. In animals, allotriploids are commonly sterile, except for some vertebrate species complexes in which allotriploids reproduce by parthenogenesis, gynogenesis and/or hybridogenesis, producing generally clonal or hemiclonal gametes; nuclear DNA introgression between hybridizing species is considered to be extremely rare. Employing species‐specific molecular markers, we show genetic introgression between the chromosomally well‐differentiated salmonids Atlantic salmon (2n = 58) and brown trout (2n = 80) through spontaneous bisexual reproduction of allotriploids leading to salmon‐like offspring bearing some brown trout genes. Although introgression between theseSalmospecies can occur via allotriploids, we hypothesize that extinction of parental species can be discarded based on very low survival of allotriploid offspring.
Host islands within the California Northern Channel Islands create fine‐scale genetic structure in two sympatric species of the symbiotic ectomycorrhizal fungusRhizopogon
Authors: GRUBISHA LISA C. , BERGEMANN SARAH E. , BRUNS THOMAS D. 
Published: February 2007

AbstractWe have examined fine‐scale genetic structure of the symbiotic ectomycorrhizal fungiRhizopogon occidentalisandR. vulgarison two of the California Channel Islands using five and six microsatellite loci, respectively. BothRhizopogonspecies are sympatric on Santa Cruz and Santa Rosa Islands and are ectomycorrhizal with bishop pine (Pinus muricata) on both islands or Santa Rosa Island Torrey pine (P. torreyanassp.insularis) on Santa Rosa. The combination of disjunct pine host distributions and geographic barriers within and among the islands have created highly structuredRhizopogonpopulations over very short distances (8.5 km on Santa Cruz Island;FST = 0.258,FST = 0.056,R. occidentalisandR. vulgaris, respectively). Both species show similar patterns of genetic differentiation as a result of limited dispersal between host populations as revealed by a significant isolation by distance relationship (r = 0.69,P < 0.04;r = 0.93,P < 0.001,R. occidentalisandR. vulgaris, respectively) and Bayesian clustering analyses, and is most likely a function of the small foraging range of the few mammals that disperseRhizopogonon these islands and the enormous spore bank characteristic ofRhizopogonspecies.
Molecular function of WhiB4/Rv3681c of Mycobacterium tuberculosis H37Rv: a [4Fe−4S] cluster co‐ordinating protein disulphide reductase
Authors: Alam Md. Suhail , Garg Saurabh K. , Agrawal Pushpa 
Published: February 2007

SummaryThe genome sequence of Mycobacterium tuberculosis H37Rv revealed the presence of seven whiB‐like open reading frames. In spite of several genetic studies on whiB genes, the biochemical properties of WhiB proteins are poorly understood. All WhiB‐like proteins have four conserved cysteine residues, out of which two are present in a CXXC motif. We report for the first time the detailed biochemical and biophysical properties of M. tuberculosis WhiB4/Rv3681c and demonstrate the functional relevance of four conserved cysteines and the CXXC motif. UV‐visible absorption spectra of freshly purified mWhiB4 showed the presence of a [2Fe−2S] cluster, whereas the electron paramagnetic resonance (EPR) spectra of reconstituted protein showed the presence of a [4Fe−4S] cluster. The iron–sulphur cluster was redox sensitive but stably co‐ordinated to the protein even in the presence of high concentration of chaotropic agents. Despite primary sequence divergence from thioredoxin family proteins, the apo mWhiB4 has properties similar to thioredoxins and functions as a protein disulphide reductase, whereas holo mWhiB4 is enzymatically inactive. Apart from the cysteine thiol of CXXC motif the distantly placed thiol pair also contributes equally to the enzymatic activity of mWhiB4. A functional model of mWhiB4 in redox signaling during oxidative stress in M. tuberculosis has been presented.
Rapamycin‐mediated G1 arrest involves regulation of the Cdk inhibitor Sic1 in Saccharomyces cerevisiae
Authors: Zinzalla Vittoria , Graziola Michele , Mastriani Andrea , Vanoni Marco , Alberghina Lilia 
Published: February 2007

SummaryThe rapamycin‐sensitive (TOR) signalling pathway in Saccharomyces cerevisiae controls growth and cell proliferation in response to nutrient availability. Rapamycin treatment causes cells to arrest growth in G1 phase. The mechanism by which the inhibition of the TOR pathway regulates cell cycle progression is not completely understood. Here we show that rapamycin causes G1 arrest by a dual mechanism that comprises downregulation of the G1‐cyclins Cln1‐3 and upregulation of the Cdk inhibitor protein Sic1. The increase of Sic1 level is mostly independent of the downregulation of the G1 cyclins, being unaffected by ectopic CLN2 expression, but requires Sic1 phosphorylation of Thr173, because it is lost in cells expressing Sic1T173A. Rapamycin‐mediated Sic1 upregulation involves nuclear accumulation of a more stable, non‐ubiquitinated protein. Either SIC1 deletion or CLN3 overexpression results in non‐cell‐cycle‐specific arrest upon rapamycin treatment and makes cells sensitive to a sublethal dose of rapamycin and to nutrient starvation. In conclusion, our data indicate that Sic1 is involved in rapamycin‐induced G1 arrest and that deregulated entrance into S phase severely decreases the ability of a cell to cope with starvation conditions induced by nutrient depletion or which are mimicked by rapamycin treatment.
The molecular basis of selective promoter activation by the σS subunit of RNA polymerase
Authors: Typas Athanasios , Becker Gisela , Hengge Regine 
Published: February 2007

SummaryDifferent environmental stimuli cause bacteria to exchange the sigma subunit in the RNA polymerase (RNAP) and, thereby, tune their gene expression according to the newly emerging needs. Sigma factors are usually thought to recognize clearly distinguishable promoter DNA determinants, and thereby activate distinct gene sets, known as their regulons. In this review, we illustrate how the principle sigma factor in stationary phase and in stressful conditions in Escherichia coli, σS (RpoS), can specifically target its large regulon in vivo, although it is known to recognize the same core promoter elements in vitro as the housekeeping sigma factor, σ70 (RpoD). Variable combinations of cis‐acting promoter features and trans‐acting protein factors determine whether a promoter is recognized by RNAP containing σS or σ70, or by both holoenzymes. How these promoter features impose σS selectivity is further discussed. Moreover, additional pathways allow σS to compete more efficiently than σ70 for limiting amounts of core RNAP (E) and thereby enhance EσS formation and effectiveness. Finally, these topics are discussed in the context of sigma factor evolution and the benefits a cell gains from retaining competing and closely related sigma factors with overlapping sets of target genes.