Individual differences in children's innovative problem-solving are not predicted by divergent thinking or executive functions

Recent studies of children''s tool innovation have revealed that there is variation in children''s success in middle-childhood. In two individual differences studies, we sought to identify personal characteristics that might predict success on an innovation task. In Study 1, we found that although measures of divergent thinking were related to each other they did not predict innovation success. In Study 2, we measured executive functioning including: inhibition, working memory, attentional flexibility and ill-structured problem-solving. None of these measures predicted innovation, but, innovation was predicted by children''s performance on a receptive vocabulary scale that may function as a proxy for general intelligence. We did not find evidence that children''s innovation was predicted by specific personal characteristics.     

The effects of historical fragmentation on major histocompatibility complex class II β and microsatellite variation in the Aegean island reptile,Podarcis erhardii

The major histocompatibility complex (MHC) plays a key role in disease resistance and is the most polymorphic gene region in vertebrates. Although habitat fragmentation is predicted to lead to a loss in MHC variation through drift, the impact of other evolutionary forces may counter this effect. Here we assess the impact of selection, drift, migration, and recombination on MHC class II and microsatellite variability in 14 island populations of the Aegean wall lizard Podarcis erhardii. Lizards were sampled from islands within the Cyclades (Greece) formed by rising sea levels as the last glacial maximum approximately 20,000 before present. Bathymetric data were used to determine the area and age of each island, allowing us to infer the corresponding magnitude and timing of genetic bottlenecks associated with island formation. Both MHC and microsatellite variation were positively associated with island area, supporting the hypothesis that drift governs neutral and adaptive variation in this system. However, MHC but not microsatellite variability declined significantly with island age. This discrepancy is likely due to the fact that microsatellites attain mutation‐drift equilibrium more rapidly than MHC. Although we detected signals of balancing selection, recombination and migration, the effects of these evolutionary processes appeared negligible relative to drift. This study demonstrates how land bridge islands can provide novel insights into the impact of historical fragmentation on genetic diversity as well as help disentangle the effects of different evolutionary forces on neutral and adaptive diversity.     

Allogromiid foraminifera and gromiids from under the Ross Ice Shelf: morphological and molecular diversity

Allogromiid foraminifera and gromiids constitute an important but poorly known component of the meiobenthos in high-latitude marine settings. Here, we present a first report on the diversity of these protists, together with an account of co-occurring invertebrate taxa, in a sample of sea floor sediment from a water depth of 923 m under the Ross Ice Shelf. Light microscopy of sieved sediment yielded 14 allogromiid foraminifera and three Gromia spp. morphotypes. We also obtained 36 partial small subunit rDNA sequences of allogromiids, including 19 sequences of individual isolates and 17 sequences from environmental DNA samples. Phylogenetic analyses of the obtained sequences identified 18 phylotypes, of which seven were closely related to previously sequenced allogromiids, while 11 represented new lineages. Our results demonstrate that a rich meiofaunal assemblage is present under the Ross Ice Shelf, 12 km from the open ocean. Molecular phylogenetic analyses of these allogromiid foraminifera point to the endemic character of the Ross Ice Shelf assemblage; however, more extensive sampling of the molecular diversity of this group of foraminifera in the Antarctic deep sea is necessary to confirm this conclusion.     

Timing of neuromuscular activation of the quadriceps and hamstrings prior to landing in high school male athletes, female athletes, and female non-athletes.

There is a discrepancy between males and females in regards to lower extremity injury rates, particularly at the knee [Agel, J., Arendt, E.A., Bershadsky, B., 2005. Anterior cruciate ligament injury in National Collegiate Athletic Association basketball and soccer: a 13-year review. American Journal of Sports Medicine 33, (4) 524-530]. Gender differences in neuromuscular recruitment characteristics of the muscles that stabilize the knee are often implicated as a factor in this discrepancy. There is considerable research in the area of gender differences in regards to neuromuscular characteristics of the lower extremity in response to perturbation; however, most studies have been performed on the adult population only. Additionally, there is no consensus as to the gender differences that have been demonstrated. The purpose of this study was to compare muscular preactivation of selected lower extremity muscles (vastus medialis, rectus femoris, and medial/lateral hamstrings) in adolescent female basketball athletes, male basketball athletes, and female non-athletes in response to a drop landing. Subjects in the female non-athlete group recruited rectus femoris significantly slower than both the female athlete and male athlete groups (619.9=588.5>200.1ms prior to ground contact). The female non-athlete group also demonstrated a significantly slower vastus medialis compared to the female athlete group (127.1 vs 408.1ms), but not significantly slower than the male athlete group (127.1 vs 275.7ms). There were no differences between female athletes and male athletes for time to initial contraction of any muscle groups. No differences were found among the groups for medial or lateral hamstring activation. This study demonstrates that physical conditioning due to basketball participation appears to affect neuromuscular recruitment in adolescents and reveals a necessity to find alternate methods of training the hamstrings for improved neuromuscular capabilities to prevent injury.     

Pseudomonas aeruginosa virulence genes identified in a Dictyostelium host model

The human pathogen Pseudomonas aeruginosa has been shown previously to use similar virulence factors when infecting mammalian hosts or Dictyostelium amoebae. Here we randomly mutagenized a clinical isolate of P. aeruginosa , and identified mutants with attenuated virulence towards Dictyostelium . These mutant strains also exhibited a strong decrease in virulence when infecting Drosophila and mice, confirming that P. aeruginosa makes use of similar virulence traits to confront these very different hosts. Further characterization of these bacterial mutants showed that TrpD is important for the induction of the quorum-sensing circuit, while PchH and PchI are involved in the induction of the type III secretion system. These results demonstrate the usefulness and the relevance of the Dictyostelium host model to identify and analyse new virulence genes in P. aeruginosa .     

Iron accumulation in bronchial epithelial cells is dependent on concurrent sodium transport

Airway epithelial cells prevent damaging effects of extracellular iron by taking up the metal and sequestering it within intracellular ferritin. Epithelial iron transport is associated with transcellular movement of other cations including changes in the expression or activity of Na, K-ATPase and epithelial Na(+) channel (ENaC). Given this relationship between iron and Na(+), we hypothesized that iron uptake by airway epithelial cells requires concurrent Na(+) transport. In preliminary studies, we found that Na(+)-free buffer blocked iron uptake by human airway epithelial cell. Na(+) channels inhibitors, including furosemide, bumetanide, and ethylisopropyl amiloride (EIPA) significantly decreased epithelial cell concentrations of non-heme iron suggesting that Na(+)-dependent iron accumulation involves generalized Na(+) flux into the cells rather than participation of one or more specific Na(+) channels. In addition, efflux of K(+) was detected during iron uptake, as was the influx of phosphate to balance the inward movement of cations. Together, these data demonstrate that intracellular iron accumulation by airway epithelium requires concurrent Na(+)/K(+)exchange.     

Recruitment of doctors to non-standard grades in the NHS: analysis of job advertisements and survey of advertisers

Objectives To estimate the proportion of advertised non-consultant hospital posts that do not conform to nationally recognised terms and conditions of service and to investigate why these posts exist, who fills them, and what the doctors in such jobs do.Design Analysis of job advertisements and a cross sectional survey of advertisers.Setting Job advertisements in one of the leading UK publications listing hospital doctor vacancies (BMJ Careers).Results Nearly a quarter of non-consultant posts advertised in the two study periods (23% and 21%) were for non-standard grade posts. A questionnaire was sent to the medical staffing officer for each post. Of 430 questionnaires sent out 192 (45%) were returned. 98 trusts said they advertised non-standard grades because there was no more funding from the deanery for approved posts and 75 because service needs could not be met by doctors in training grades. In 132 posts (69%) the post holder would be required to do on-call work, and 50 advertisers (26%) required on-call duty for 1 in 5 or more frequently, which would conflict with the European Working Time Directive. 131 advertisers (68%) expected the posts to be filled by doctors from outside the European Economic Area.Conclusions Non-standard grade posts are mostly being created to meet service requirements when there is no more funding for standard training posts and are expected to be filled by doctors from overseas. Doctors in such posts can be more easily exploited and their careers hindered. The Department of Health''s annual census should include non-standard grade doctors.     

Added Weights Lead to Reduced Flight Behavior and Mating Success in Polyandrous Honey Bee Queens (Apis mellifera)

Honey bee queens are exceptionally promiscuous. Early in life, queens perform one to five nuptial flights, mating with up to 44 drones. Many studies have documented potential benefits of multiple mating. In contrast, potential costs of polyandry and the sensitivity of queens to such costs have largely been ignored because they are difficult to address experimentally. To consider one aspect of mating costs to queens, the difficulty of flight, we compared flight behavior and success among a group of control queens and two experimental groups of queens that carried lead weights of two different sizes. For each queen, we assessed the number and duration of all flights and, after egg-laying commenced, the amount of stored sperm and the number of mates in terms of the offspring's patrilineal genetic diversity. Added weights quantitatively decreased the number of flights, the mean duration of flights and consequently the total time spent flying. Mating success in terms of sperm quantity and patrilines detected among the queens' offspring was also negatively impacted by the experimental manipulation. Thus, it can be concluded that the flight effort of honey bee queens during their mating period is adjusted in response to an experimentally increased cost of flying with multiple consequences for their mating success. Our results suggest that queen behavior is flexible and mating costs deserve more attention to explain the extreme polyandry in honey bees.     

Characterization of EVL-I as a protein kinase D substrate

EVL-I is a splice variant of EVL (Ena/VASP like protein), whose in vivo function and regulation are still poorly understood. We found that Protein Kinase D (PKD) interacts in vitro and in vivo with EVL-I and phosphorylates EVL-I in a 21 amino acid alternately-included insert in the EVH2 domain. Following knockdown of the capping protein CPβ and spreading on laminin, phosphorylated EVL-I can support filopodia formation and the phosphorylated EVL-I is localized at filopodial tips. Furthermore, we found that the lamellipodial localization of EVL-I is unaffected by phosphorylation, but that impairment of EVL-I phosphorylation is associated with ruffling of lamellipodia upon PDBu stimulation. Besides the lamellipodial and filopodial localization of phosphorylated EVL-I in fibroblasts, we determined that EVL-I is hyperphosphorylated and localized in the cell–cell contacts of certain breast cancer cells and mouse embryo keratinocytes. Taken together, our results show that phosphorylated EVL-I is present in lamellipodia, filopodia and cell–cell contacts and suggest the existence of signaling pathways that may affect EVL-I via phosphorylation of its EVH2 domain.