bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does microhabitat structure affect foliar mite assemblages?
Authors: O'CONNELL DEAN M. , LEE WILLIAM G. , MONKS ADRIAN , DICKINSON KATHARINE J. M. 
Published: March 2010

1. Habitat structure is an important factor influencing population dynamics and trophic organisation of terrestrial invertebrates. The phylloplane zone on vascular plant leaves is topographically complex, containing a multitude of microhabitats such as leaf hairs, lesions, and structural refugia such as domatia, which may modify interactions between resident invertebrate communities, colonisers, and subsequent trophic relationships. Leaf domatia are small indentations on the underside of leaves and are often inhabited by potentially beneficial mites and other arthropods.2. This study investigated the relationship between domatia availability and foliar mite assemblages in contrasting habitats (native forest, plantation forest, and pasture) using a standard test plant (the endemic New Zealand shrubCoprosma lucida, J.R. & G. Forst.).3. Diverse woody native vegetation types supported higher numbers of mite species than either plantation forest or pastoral grasses. The highest number of mite species occurred in the native forest (63%), plantation forest (38%), and pastoral grasses (25%). In the native vegetation type, experimentalC. lucidaleaves with domatia supported higher mite densities, greater colonisation success, and more diverse mite assemblages than those without domatia. Mite assemblages within the pastoral site were significantly different from the other two vegetation types. Only one fungivorous mite species,Orthotydeus californicus, occurred compared to five mite species in native and plantation forests.4. This study indicated that foliar mite assemblages in native vegetation on experimentalC. lucidashrubs are influenced by domatia availability, resident foliar mites, and local mite assemblages.
Intra‐specific body size variation inPolistespaper wasps as a response to social parasite pressure
Authors: ORTOLANI IRENE , CERVO RITA 
Published: March 2010

1. Like avian brood parasites, obligate insect social parasites exploit the parental care of a host species to rear their brood, causing an evident loss of host reproductive success. This fitness cost imposes selective pressure on the host to reduce the parasite effect. A possible outcome of an evolutionary arms race is the selection of host morphological counter‐adaptations to resist parasite attacks.2. We studied host–parasite pairs ofPolisteswasps in which the fighting equipment of the parasite's body allows it to enter the host colony.3. We searched for host morphological traits related to fighting ability that could be considered counter‐adaptations. As a host–parasite co‐evolutionary arms race can only occur where the two lineages co‐exist, we compared morphological traits of hosts belonging to populations with or without parasite pressure. We report that host foundresses belonging to populations under strong parasite pressure have a larger body size than those belonging to populations without parasite pressure.4. Behavioural experiments carried out to test if an increase in host body size is useful to oppose parasite usurpation show that large body size foundresses exhibit a greater ability of nest defence.
Climate change affects the duration of the reproductive season in birds
Authors: Møller A. P. , Flensted‐Jensen E. , Klarborg K. , Mardal W. , Nielsen J. T. 
Published: March 2010

Summary1. The duration of the reproductive season may depend on the duration of the growing season, with recent amelioration in spring temperatures allowing earlier start of reproduction. Earlier start of reproduction may allow a longer breeding season because of more broods a longer interval between broods for multi‐brooded species.2. We analysed extensive long‐term data sets on timing of breeding in 20 species of birds from Denmark, based on records of over 100 000 individual offspring, showing considerable heterogeneity among species in temporal change in duration of the breeding season.3. Multi‐brooded species increased the duration of their breeding season by 0·43 days year−1while single‐brooded species decreased the duration of their breeding season by 0·44 days year−1. This implies that recent climate change has allowed more broods or better temporal spacing of broods in multi‐brooded species, while the time window for reproduction has become narrower in single‐brooded species.4. The single‐most important predictor of change in duration of the breeding season was change in the date breeding started; there was no change in the date of end of breeding. Species advancing their breeding date the most also expanded the duration of the breeding season. In contrast, long‐distance migration and generation time did not predict change in duration of the breeding season.
Executive function in adolescents with Down Syndrome
Authors: Lanfranchi S. , Jerman O. , Dal Pont E. , Alberti A. , Vianello R. 
Published: March 2010

AbstractBackground  The present work is aimed at analysing executive function (EF) in adolescents with Down Syndrome (DS). So far, EF has been analysed mainly in adults with DS, showing a pattern of impairment. However, less is known about children and adolescents with this syndrome. Studying adolescents with DS might help us better understand whether performances on EF tasks of individuals with DS are determined by age or by Alzheimer disease, as some studies suggest, or whether their performances are directly related to DS cognitive profile.Method  A battery of EF tasks assessing set shifting, planning/problem‐solving, working memory, inhibition/perseveration and fluency, as well as a tasks assessing sustained attention has been administered to a group of 15 adolescents with DS and 15 typically developing children matched for mental age. All EF tasks were selected from previous studies with individuals with intellectual disabilities or from developmental literature and are thought to be useful for the samples considered.Results  The present results revealed that the group of individuals with DS performed at a significantly lower level on tasks assessing set shifting, planning/problem‐solving, working memory and inhibition/perseveration, but not on the tasks assessing fluency. In addition, individuals with DS demonstrated a greater number of errors and less strategy use for the sustained attention task.Conclusions  The results suggest a broad impairment in EF in adolescents with DS, and are consistent with several similar studies conducted with adults with DS. We assume that EF deficit is a characteristic of DS.
Ecological rather than geographical isolation dominates Quaternary formation of Mediterranean Cistus species
Authors: FERNÁNDEZ‐MAZUECOS M. , VARGAS P. 
Published: March 2010

AbstractThe lack of a comparative approach makes it impossible to determine the main factors influencing colonization and evolution in plants. Here we conducted the first comparative study of a characteristic Mediterranean lineage (white‐flowered Cistus) taking advantage of its well‐known phylogenetic relationships. A two‐scale approach was applied to address the hypothesis of higher levels of isolation in mountain than in lowland species. First, a time‐calibrated phylogeny using plastid sequences of Cistaceae suggested that the origin of Cistus species postdated both the refilling of the Mediterranean Sea (5.59–5.33 Ma) and the onset of the Mediterranean climate (3.2 Ma). Two hundred and sixty‐three additional, plastid sequences from 111 populations showed different numbers of haplotypes in C. laurifolius (7), C. monspeliensis (2) and C. salviifolius (7). Although haplotype sharing among disjunct populations was observed in all species, phylogeographic analyses revealed haplotype lineages exclusive to Europe or Africa only in the mountain species (C. laurifolius). Isolation by either geographical distance or sea barriers was not significantly supported for the lowland species (C. monspeliensis; C. ladanifer from a previous study). The same is true for the less habitat‐specific species of the lineage (C. salviifolius). Comparative phylogeography of the Cistus species leads us to interpret a general pattern of active colonization surpassing Mediterranean barriers. In contrast, ecological conditions (precipitation, temperature, soils) appear to have determined the distribution of the Cistus species of Mediterranean mountains. This study further provides molecular evidence for multiple colonization patterns in the course of successful adaptation of Cistus species to Mediterranean habitats.
A dominant‐negative needle mutant blocks type III secretion of early but not late substrates in Yersinia
Authors: Davis Alison J. , De Jesús Díaz Dennise A. , Mecsas Joan 
Published: March 2010

Summary Yersinia pseudotuberculosis uses a type III secretion system (T3SS) to deliver effectors into host cells. A key component of the T3SS is the needle, which is a hollow tube on the bacterial surface through which effectors are secreted, composed of the YscF protein. To study needle assembly, we performed a screen for dominant‐negative yscF alleles that prevented effector secretion in the presence of wild‐type (WT) YscF. One allele, yscF‐L54V, prevents WT YscF secretion and needle assembly, although purified YscF‐L54V polymerizes in vitro. YscF‐L54V binds to its chaperones YscE and YscG, and the YscF‐L54V–EG complex targets to the T3SS ATPase, YscN. We propose that YscF‐L54V stalls at a binding site in the needle assembly pathway following its release from the chaperones, which blocks the secretion of WT YscF and other early substrates required for building a needle. Interestingly, YscF‐L54V does not affect the activity of pre‐assembled actively secreting machines, indicating that a factor and/or binding site required for YscF secretion is absent from T3SS machines already engaged in effector secretion. Thus, substrate switching may involve the removal of an early substrate‐specific binding site as a mechanism to exclude early substrates from Yop‐secreting machines.
NAD+ auxotrophy is bacteriocidal for the tubercle bacilli
Authors: Vilchèze Catherine , Weinrick Brian , Wong Ka‐Wing , Chen Bing , Jacobs, Jr William R. 
Published: March 2010

SummaryThe human tubercle bacillus Mycobacterium tuberculosis can synthesize NAD+ using the de novo biosynthesis pathway or the salvage pathway. The salvage pathway of the bovine tubercle bacillus Mycobacterium bovis was reported defective due to a mutation in the nicotinamidase PncA. This defect prevents nicotinic acid secretion, which is the basis for the niacin test that clinically distinguishes M. bovis from M. tuberculosis. Surprisingly, we found that the NAD+de novo biosynthesis pathway (nadABC) can be deleted from M. bovis, demonstrating a functioning salvage pathway. M. bovisΔnadABC fails to grow in mice, whereas M. tuberculosisΔnadABC grows normally in mice, suggesting that M. tuberculosis can acquire nicotinamide from its host. The introduction of M. tuberculosis pncA into M. bovisΔnadABC is sufficient to fully restore growth in a mouse, proving that the functional salvage pathway enables nicotinamide acquisition by the tubercle bacilli. This study demonstrates that NAD+ starvation is a cidal event in the tubercle bacilli and confirms that enzymes common to the de novo and salvage pathways may be good drug targets.
Regulation of phosphate uptake via Pst transporters in Halobacterium salinarum R1
Authors: Furtwängler Katarina , Tarasov Valery , Wende Andy , Schwarz Christoph , Oesterhelt Dieter 
Published: March 2010

SummaryThe genome of the archaeon Halobacterium salinarum contains two copies of the pst (phosphate‐specific transport) operon, the genes of which are related to well‐studied bacterial homologues. Both operons (pst1 and pst2) were shown to be polycistronic and, when under Pi‐limited conditions, transcription initiated 1 bp upstream of the translational starts. Under Pi saturation, the pst1 operon utilized an additional transcription start site 59 bp upstream of the first one. The leaderless pst1 transcript was found to be more efficiently translated than the leadered transcript. Promoter strengths differed significantly between the two operons and when Pi levels changed. The basal pst1 promoter activity in Pi‐saturated conditions was minimal while the pst2 promoter was active. In contrast, phosphate limitation induced the pst1 operon threefold more than the pst2 operon. We identified basic and phosphate‐dependent cis‐acting elements in both promoters. Phosphate‐uptake assays conducted with several Pst1 and Pst2 mutant strains revealed differences in the substrate affinities between the two transporters and also suggested that the Pi‐binding proteins PstS1 and PstS2 can interact with either of the two permease subunits of the transporters. The tactic behaviour of wild type and pst‐deletion strains showed that the Pst1 transporter plays an important role for phosphate‐directed chemotaxis.
Fitness correlates with the extent of cheating in a bacterium
Authors: JIRICNY N. , DIGGLE S. P. , WEST S. A. , EVANS B. A. , BALLANTYNE G. , ROSS‐GILLESPIE A. , GRIFFIN A. S. 
Published: March 2010

AbstractThere is growing awareness of the importance of cooperative behaviours in microbial communities. Empirical support for this insight comes from experiments using mutant strains, termed ‘cheats’, which exploit the cooperative behaviour of wild‐type strains. However, little detailed work has gone into characterising the competitive dynamics of cooperative and cheating strains. We test three specific predictions about the fitness consequences of cheating to different extents by examining the production of the iron‐scavenging siderophore molecule, pyoverdin, in the bacterium Pseudomonas aeruginosa. We create a collection of mutants that differ in the amount of pyoverdin that they produce (from 1% to 96% of the production of paired wild types) and demonstrate that these production levels correlate with both gene activity and the ability to bind iron. Across these mutants, we found that (1) when grown in a mixed culture with a cooperative wild‐type strain, the relative fitness of a mutant is negatively correlated with the amount of pyoverdin that it produces; (2) the absolute and relative fitness of the wild‐type strain in the mixed culture is positively correlated with the amount of pyoverdin that the mutant produces; and (3) when grown in a monoculture, the absolute fitness of the mutant is positively correlated with the amount of pyoverdin that it produces. Overall, we demonstrate that cooperative pyoverdin production is exploitable and illustrate how variation in a social behaviour determines fitness differently, depending on the social environment.
Give ‘til it hurts: trade‐offs between immunity and male reproductive effort in the decorated cricket, Gryllodes sigillatus
Authors: GERSHMAN S. N. , BARNETT C. A. , PETTINGER A. M. , WEDDLE C. B. , HUNT J. , SAKALUK S. K. 
Published: March 2010

AbstractTrade‐offs between life‐history variables can be manifested at either the phenotypic or genetic level, with vastly different evolutionary consequences. Here, we examined whether male decorated crickets (Gryllodes sigillatus) from eight inbred lines and the outbred founder population from which they were derived, trade‐off immune effort [lytic activity, phenoloxidase (PO) activity or encapsulation] to produce spermatophylaxes: costly nuptial food gifts essential for successful sperm transfer. Canonical correlation analysis of the outbred population revealed a trade‐off between spermatophylax mass and lytic activity. Analysis of our inbred lines, however, revealed that although PO activity, encapsulation, body mass, spermatophylax mass and ampulla (sperm capsule) mass were all highly heritable, lytic activity was not, and there was, therefore, no negative genetic correlation between lytic activity and spermatophylax mass. Thus, males showed a phenotypic but not a genetic trade‐off between spermatophylax mass and lytic activity, suggesting that this trade‐off is mediated largely by environmental factors.
Psychological and behavioural impacts of the 2008 China earthquake on blood donors
Authors: Tian F. , Wang J. , Huang Y. , Guo X. , Yun Z. , Yang T. , Nelson K. , Schreiber G. B. , Ness P. , Shan H. 
Published: March 2010

Background and Objectives  On May 12, 2008, a severe earthquake hit Sichuan province in China. A post‐earthquake survey was conducted to study the earthquake’s effect on blood donor behaviour and stress at three blood centres at varying distances from the epicentre.Materials and Methods  A questionnaire was developed to assess donor post‐traumatic stress disorders (PTSD) and attitudes toward giving blood. Responses were compared by centre and donor characteristics using multivariate logistic regression techniques.Results  Of all 17 456 donors, the overall prevalence of PTSD was 13·2%. Donors who knew someone killed or injured by the earthquake were 2·1 times more likely to have PTSD than others (95% CI: 1·8–2·4). 85·2% of donors cited the earthquake as their reason for donating. 16·1% of donors felt it acceptable to be less honest about one’s health history in an emergency. After adjusting for PTSD, geographic and demographic characteristics, the donors knowing someone killed or injured by the earthquake were 1·4 times (95% CI: 1·2–1·7) more likely to cite the earthquake as reason for donating, and 1·8 times (95% CI: 1·5–2·1) more likely to accept being less honest about one’s health history in case of national emergency.Conclusions  The psychological and behavioural impacts of the earthquake on blood donors extended far from the epicentre. After a disaster, it is important to emphasize that donors must be truthful on the donor questionnaire as some donors appear willing to be less than honest when they perceive an increased need for blood products.
Construct validity of the Comprehensive Developmental Inventory for Infants and Toddlers
Authors: Hwang Ai‐Wen , Weng Li‐Jen , Liao Hua‐Fang 
Published: March 2010

AbstractBackground: The aim of this study was to investigate the construct validity of the diagnostic test, the Comprehensive Developmental Inventory for Infants and Toddlers (CDIIT).Methods: A total of 1085 children in four age groups (infant, 1‐year‐old, 2‐year‐old, preschool age) were enrolled. The Developmental Quotient of each subdomain of the five CDIIT subtests (Cognition, Language, Motor, Social, and Self‐help) was used as the basic unit for factor analysis with the iterative principle factor method and promax rotation.Results: The two‐factor solution in two younger age groups and 2‐ or 3‐factor solutions in the 2‐year‐old and preschool groups provided superior factor structure in terms of interpretability and compatibility with existing child development theories.Conclusion: Although five constructs were proposed in the original manual of CDIIT, two to three constructs were revealed in this empirical study.
Impact of sustained neuromuscular blockade on outcome of mechanically ventilated children
Authors: Da Silva Paulo S.L. , Neto Henrique M. , De Aguiar Vânia E. , Lopes Jr Emílio , De Carvalho Werther B. 
Published: March 2010

AbstractBackground:  Neuromuscular blocking agents (NMBA) are commonly administered to critically ill children in pediatric intensive care units (PICU) in the USA and Europe. Although NMBA are frequently used in PICU patients, their role in the PICU setting has not yet been clearly defined. The aim of this study was to describe the sustained administration of NMBA and its impact on outcome of PICU patients.Methods:  A 3‐year retrospective cohort study was conducted to compare mechanically‐ventilated patients who received NMBA for at least 12 h with patients who did not (control group).Results:  A total of 317 consecutive patients were ventilated over 3473 days. Patients were similar in age, weight and severity scores. Thirty‐four children (10.7%) received NMBA. Compared with controls, the neuromuscular blockade (NMB) group had a longer duration of mechanical ventilation (13.7 vs 5.5 days, P= 0.000), longer PICU stay (20 vs 11 days, P= 0.000) and increased occurrence of ventilator‐associated pneumonia (6.6 vs 4.1/1000 ventilator days, P= 0.010). The NMB use was not associated with higher mortality (8.8% vs 17.6%, P= 0.287) or longer hospital stay (30.5 vs 23 days, P= 0.117).Conclusion:  Although the use of NMBA was not associated with greater mortality, we found that sustained use of NMBA is associated with prolonged mechanical ventilation, longer PICU stay and higher incidence of ventilator‐associated pneumonia when compared with controls. Larger studies are necessary to confirm these findings.
Evolution in pediatric health care
Authors: Genuis Stephen J. 
Published: March 2010

AbstractBackground:  There is disturbing evidence of escalating chronic disease among children – a phenomenon that is extracting a heavy toll from individuals, families, and health‐care systems.Methods:  This review was prepared by assessing medical and scientific literature available from Medline, as well as by reviewing numerous books, conference proceedings, and government publications.Results:  Knowledge translation in medical science, the process whereby new research is incorporated into clinical practice, remains lethargic. Nutritional and environmental factors have recently been recognized as common determinants of modern illness, and various diagnostic techniques in molecular medicine are now available to facilitate diagnosis of disease etiology.Conclusions:  A re‐evaluation of the current pediatric clinical paradigm is required in light of emerging research from fields such as epigenetics, molecular medicine and environmental health. Education about these branches of medical science should be integrated into pediatric medical education, and important research information from these disciplines should be incorporated into public health care and clinical practice relating to children.
Eleven‐year study of causes of neonatal bacterial meningitis in Ahvaz, Iran
Authors: Aletayeb Mohammad Hasan , Ahmad Farajzadeh Sheikh , Masood Dehdashtian 
Published: March 2010

AbstractBackground:  Bacterial meningitis is a devastating infection with a high mortality rate, especially in neonates. The aim of this study was to determine the causative agents that cause bacterial meningitis in Khuzestan province in the south‐western region of Iran.Methods:  A descriptive, cross‐sectional study was carried out from 1997 to 2007 at the neonatal ward of a university teaching hospital (Emam Khomeini hospital) in Ahvaz. All infants younger than 29 days old who suffered from meningitis were included. Laboratory tests included Gram stain, culture, and biochemical tests. Cases were defined as meningitis if the cerebrospinal fluid culture was positive.Results:  Based on cerebrospinal fluid culture, 31 infants were identified as having bacterial meningitis. Eleven (35.5%) of these cases were caused by Klebsiella pneumoniae, nine (29%) were caused by Enterobacter spp., three (9.6%) were caused by Escherichia coli, three (9.6%) were caused by Enterococcus spp., two (6.4%) were caused by Acinetobacter, and one case each (3.2%) was caused by Staphylococcus aureus, Pseudomonas aeruginosa and nontypeable Haemophilus influenzae. The male‐to‐female ratio was 2 : 1 (67.7% were male). The birthweights of 20 (64.5%) patients were under 2500 g and 11 (35.4%) patients had normal birthweights. Thirteen (42%) were early‐onset cases and 18 (58%) were late‐onset cases. More than half of the cases (54.8%) acquired the infection from the hospital. Blood cultures were positive for 18 (58%) patients. Thirty‐two percent of cases died in spite of treatment.Conclusions:  Klebsiella pneumoniae and Enterobacter spp. were the two main causative agents that caused neonatal bacterial meningitis, and nosocomial meningitis was the most common type in our ward.