bluuebunny/crossref_metadata_2025 huggingface dataset:
Aunties and Uncles Co‐operative Family Project: the experiences of children, volunteers and parents
Authors: Beale B. , Wilkes L. , Power B. , Beale R.
Published: July 2007

Background This paper reports on the experiences of the children (nieces and nephews), volunteers (aunts and uncles) and parents involved in the Aunties and Uncles Co‐operative Family Project in Sydney, Australia. The project has run for 30 years as an extended family network of community volunteers and has never been evaluated.

Methods A survey comprising open‐ended and closed questions relating to the service was administered to all stakeholders. Demographic data were collected on all respondents. The text from answers to open‐ended questions on the survey was coded for similarities and differences and was categorized. From the categories, the experiences of children, volunteers and parents were written with exemplars from the respondents' text.

Results Three major categories emerged from the text: enjoyment/satisfaction of the experience for volunteers, children and parents; family relationships; and the difference it has made to me (children, parents and volunteers).

Conclusions The long‐term benefits of a supportive ‘extended family type’ relationship were recognized by all participants. Although the children were the primary focus of the project, parents and volunteers also described the rewards they experienced. The volunteer element was integral to providing the wide‐ranging, ongoing supports which would not be possible from a paid staff basis.
Age‐related changes in the occurrence and characteristics of thymic CD4+ CD25+ T cells in mice
Authors: Kozlowska Ewa , Biernacka Marzena , Ciechomska Marzena , Drela Nadzieja
Published: July 2007

Natural regulatory CD4+ CD25+ T cells play an important role in preventing autoimmunity by maintaining self‐tolerance. They express CD25 constitutively and are produced in the thymus as a functionally mature T‐cell population. Changes in the potential of these cells to regulate the activity of conventional effector lymphocytes may contribute to an increased susceptibility to infection, cancer and age‐associated autoimmune diseases. In this study we demonstrated that the thymi of aged mice are populated by a higher percentage of CD4+ CD25+ thymocytes than in young animals. The expression of several surface markers (CD69, CD5, CD28, CTLA‐4, CD122, FOXP3), usually used to characterize the phenotype of CD4+ CD25+ T regulatory cells, was compared between young and aged mice. We also examined the ability of sorted thymus‐deriving regulatory T cells of young and aged BALB/c mice to inhibit the proliferation of lymph node lymphocytes activated in vitro. Natural regulatory T cells isolated from the thymi of young mice suppress the proliferation of responder lymph node cells. We demonstrated that thymus‐deriving CD4+ CD25+ T cells of old mice maintain their potential to suppress the proliferation of activated responder lymphocytes of young mice. However, their potential to inhibit the proliferation of old responder T cells is abrogated. Differences in the occurrence and activity of CD4+ CD25+ thymocytes between young and old animals are discussed in relation to the expression of these surface markers.
Interleukin‐31 induces cytokine and chemokine production from human bronchial epithelial cells through activation of mitogen‐activated protein kinase signalling pathways: implications for the allergic response
Authors: Ip Wai K. , Wong Chun K. , Li Mandy L. Y. , Li Pok W. , Cheung Phyllis F. Y. , Lam Christopher W. K.
Published: July 2007

Interleukin‐31 (IL‐31) is a novel T‐helper‐lymphocyte‐derived cytokine that plays an important role in allergic skin inflammation and atopic dermatitis. It has recently been implicated in bronchial inflammation. We investigated the functions and mechanisms of IL‐31‐induced activation of human bronchial epithelial cells. The gene and protein expressions of candidate cytokines/chemokines from IL‐31‐stimulated human bronchial epithelial BEAS‐2B cells were first quantified by quantitative real‐time polymerase chain reaction and enzyme‐linked immunosorbent assay, respectively. The activity of different mitogen‐activated protein kinases (MAPKs) in IL‐31‐stimulated BEAS‐2B cells was assessed by Western blot. The IL‐31 could significantly elevate the gene and protein expressions of epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein‐1 (MCP‐1/CCL2) of BEAS‐2B cells in both time‐dependently and dose‐dependently. Combination of IL‐31 with either IL‐4 or IL‐13 further enhanced VEGF and CCL2 production while IL‐31 could synergistically augment the release of EGF, VEGF, CCL2, IL‐6 and IL‐8 in cocultures of BEAS‐2B cells and eosinophils. In addition, IL‐31 could activate p38 MAPK, extracellular signal‐regulated kinase (ERK) and c‐Jun N‐terminal kinase (JNK) of BEAS‐2B cells. Selective inhibitors of p38 MAPK (SB203580), ERK (PD98059), and JNK (SP600125) could differentially inhibit the production of EGF, VEGF and CCL2, thereby suggesting a role for MAPKs in IL‐31 functions. In conclusion, the activation of MAPKs can be crucial for IL‐31‐mediated activation of bronchial epithelial cells, thereby providing an immunological role for IL‐31 in bronchial inflammation, at least partly, via epithelial EGF, VEGF and CCL2 production.
The Fps/Fes kinase regulates leucocyte recruitment and extravasation during inflammation
Authors: Parsons Sean A. , Mewburn Jeffrey D. , Truesdell Peter , Greer Peter A.
Published: July 2007

Fps/Fes and Fer comprise a distinct subfamily of cytoplasmic protein‐tyrosine kinases, and have both been implicated in the regulation of innate immunity. Previous studies showed that Fps/Fes‐knockout mice were hypersensitive to systemic lipopolysaccharide (LPS) challenge, and Fer‐deficient mice displayed enhanced recruitment of leucocytes in response to localized LPS challenge. We show here for the first time, a role for Fps in the regulation of leucocyte recruitment to areas of inflammation. Using the cremaster muscle intravital microscopy model, we observed increased leucocyte adherence to venules, and increased rates and degrees of transendothelial migration in Fps/Fes‐knockout mice relative to wild‐type animals subsequent to localized LPS challenge. There was also a decreased vessel wall shear rate in the post‐capillary venules of LPS‐challenged Fps/Fes‐knockout mice, and an increase in neutrophil migration into the peritoneal cavity subsequent to thioglycollate challenge. Using flow cytometry to quantify the expression of surface molecules, we observed prolonged expression of the selectin ligand PSGL‐1 on peripheral blood neutrophils from Fps/Fes‐knockout mice stimulated ex vivo with LPS. These observations provide important insights into the observed in vivo behaviour of leucocytes in LPS‐challenged Fps/Fes‐knockout mice and provide evidence that the Fps/Fes kinase plays an important role in the innate immune response.
Poverty, socio‐economic position, social capital and the health of children and adolescents with intellectual disabilities in Britain: a replication
Authors: Emerson E. , Hatton C.
Published: July 2007

Background  When compared with their nonintellectually disabled peers, people with intellectual disabilities (IDs) have poorer health and are more likely to be exposed to poverty during childhood. Given that exposure to child poverty has been linked to poorer health outcomes, we attempted to estimate the extent to which the health inequalities faced by children and adolescents with IDs may be accounted for by their more disadvantaged socio‐economic position.

Methods  Secondary analysis of data on a nationally representative sample of 12 160 British children aged under 17 years extracted from the Department of Work and Pensions' Families and Children Study.

Results  After controlling for age and sex, children with IDs were significantly more likely (corrected odds ratio = 2.49) to be reported to have less than good health than their nonintellectually disabled peers. However, 31% of the elevated risk for poorer health was accounted for by between‐group differences in socio‐economic position and social capital.

Conclusions  A socially and statistically significant proportion of the increased risk of poorer health among children and adolescents with IDs may be attributed to their increased risk of socio‐economic disadvantage.
Profiles and correlates of aggressive behaviour among adults with intellectual disabilities
Authors: Crocker A. G. , Mercier C. , Allaire J.‐F. , Roy M.‐E.
Published: July 2007

Background Despite the heterogeneity in aggressive behaviours observed among individuals with intellectual disabilities (ID), little attention has been paid to the identification of typologies of aggression among individuals with mild or moderate ID and their associated factors.

Objective The goal of the present study was to identify profiles of aggressive behaviour and their psychosocial correlates.

Method In this cross‐sectional study of 296 adults with mild or moderate ID, information was gathered through interviews with the ID participants, their case manager and a significant other. Client files were also reviewed.

Results Multiple correspondence analysis followed by hierarchical cluster analysis generated six distinct profiles of aggressive behaviour in this sample. The ‘violent’ group clearly stood out as lacking social and vocational involvement, having more severe mental health problems, high levels of impulsivity and antisocial tendencies compared with all other groups.

Discussion The identification of distinct profiles of aggressive behaviour offers new possibilities for studying risk factors and eventually targeting specific risk prevention strategies.
Evidence of resilience in families of children with autism
Authors: Bayat M.
Published: July 2007

Background  Family resilience is a growing field of inquiry, investigating factors that contribute to a family's becoming stronger in spite of dealing with adversity. Despite the growing interest in studying family resilience, the topic has not been explored in families with children who have disabilities. This report, a part of a larger study – using both quantitative and qualitative methodologies – is an examination of factors of family resilience in the families of children with autism. Evidence of family resilience such as family connectedness and closeness, positive meaning‐making of the disability, and spiritual and personal growth were identified and examined in this part of the study.

Method  The study uses a survey methodology, analysing responses to several rating scales and written responses to three open‐ended questions. Survey respondents consisted of 175 parents and other primary caregivers of a child with autism – ages between 2 and 18 years.

Results  Results suggest identification of specific resilience processes, such as: making positive meaning of disability, mobilization of resources, and becoming united and closer as a family; finding greater appreciation of life in general, and other people in specific; and gaining spiritual strength.

Conclusions  This study presents evidence that a considerable number of families of children with autism display factors of resilience – reporting having become stronger as a result of disability in the family.
Validation of the Subjective and Objective Family Burden Interview (SOFBI/ECFOS) in primary caregivers to adults with intellectual disabilities living in the community
Authors: Martorell A. , Pereda A. , Salvador‐Carulla L. , Ochoa S. , Ayuso‐Mateos J. L.
Published: July 2007

Background  There is little information on the psychometric properties of instruments for assessing family care burden in adults with intellectual disabilities (ID). The aim of this study is therefore to analyse the usefulness of the ‘Subjective and Objective Family Burden Interview’ (SOFBI) in the assessment of principal caregivers in Spain.

Methods  The SOFBI was administered to 166 principal caregivers of adults with ID in a vocational centre. The psychometric analysis included: internal consistency, inter‐rater and test–retest reliability, construct validity, convergent validity with the World Health Organization's Disability Assessment Schedule II, and feasibility.

Results  The Cronbach's alpha was 0.88 for the overall interview and always above 0.7 in the quantitative subdomains. The Kappa coefficients for test–retest were between 0.5 and 0.8, whereas inter‐rater agreement was nearly perfect. Maximum‐likelihood factor analysis showed four well‐defined factors, which fitted the previously designed domains. Feasibility was also good.

Conclusions  The SOFBI is a multi‐domain, modular instrument which is feasible, reliable and valid for measuring the burden of family caregivers to adults with ID living in the community.
The impact of alleged abuse on behaviour in adults with severe intellectual disabilities
Authors: Murphy G. H. , O'Callaghan A. C. , Clare I. C. H.
Published: July 2007

Background  People with intellectual disabilities (ID) are particularly vulnerable to abuse, and most incidents come to light through victim disclosure. Those people with severe or profound ID are not able to describe what has happened to them. This project aimed to describe the consequences of abuse and changes in behaviour following alleged abuse in 18 adults with severe ID.

Method  Family members or other carers were interviewed to collect information about the alleged abuse. They were also asked about the person's adaptive and challenging behaviours at three time points: in the 3 months immediately prior to the abuse (time 1), in the 3 months immediately after the abuse (time 2) and in the 3 months prior to interview (time 3).

Results  A typical pattern emerged for both adaptive and challenging behaviours: there were few problems or difficulties at time 1, major difficulties at time 2 and some recovery by time 3.

Conclusions  Evidence is mounting that clinicians considering the sequelae of abuse for people with severe or profound ID need to consider changes in adaptive and challenging behaviours, as well as the typical symptoms of post‐traumatic stress disorder.
Evolution of pathogens in a man‐made world
Authors: LEBARBENCHON CAMILLE , BROWN SAM P. , POULIN ROBERT , GAUTHIER‐CLERC MICHEL , THOMAS FRÉDÉRIC
Published: July 2007

Human activities have resulted in substantial, large‐scale environmental modifications, especially in the past century. Ecologists and evolutionary biologists are increasingly coming to realize that parasites and pathogens, like free‐living organisms, evolve as the consequence of these anthropogenic changes. Although this area now commands the attention of a variety of researchers, a broad predictive framework is lacking, mainly because the links between human activities, the environment and parasite evolution are complex. From empirical and theoretical examples chosen in the literature, we give an overview of the ways in which humans can directly or indirectly influence the evolution of different traits in parasites (e.g.specificity, virulence, polymorphism). We discuss the role of direct and indirect factors as diverse as habitat fragmentation, pollution, biodiversity loss, climate change, introduction of species, use of vaccines and antibiotics, ageing of the population, etc. We also present challenging questions for further research. Understanding the links between anthropogenic changes and parasite evolution needs to become a cornerstone of public health planning, economic development and conservation biology.
The tails of two geckos tell the story of dispersal in a fragmented landscape
Authors: DAVIES KENDI F. , MELBOURNE BRETT A.
Published: July 2007

The fragmentation of habitat is a major cause of biodiversity loss. However, while numerous studies have suggested that reducing the size of populations and isolating them on fragments leads ultimately to the extinction of a species (small isolated populations are extinction prone), the evidence has been rather conjectural. This is because dispersal is so difficult to measure and isolation difficult to confirm. In past studies, evidence that populations become small and isolated on fragments, leading to declines, has relied on spatial patterns of distribution and abundance. Thus, a species not trapped in the matrix in which fragments are embedded might be assumed isolated on fragments, and if low in abundance on fragments compared to continuous habitat is assumed to have declined on fragments due to this isolation. However, without accurately measuring the degree of isolation, it is difficult to distinguish the role of isolation from other important causes of population decline that are correlated with fragment and population size, such as habitat degradation. Developments in molecular techniques and statistical methods now make it possible to measure isolation. Refreshingly, in this issue Hoehn et al. analyse microsatellite DNA with a suite of statistical methods to show convincingly that a declining species of gecko suffers from greater isolation on habitat fragments than a contrasting gecko that is able to disperse between fragments and hence persist in the severely fragmented wheatbelt of Western Australia.
Phylogeography, hybridization and Pleistocene refugia of the kob antelope (Kobus kob)
Authors: LORENZEN ELINE D. , DE NEERGAARD RIKKE , ARCTANDER PETER , SIEGISMUND HANS R.
Published: July 2007

Mitochondrial DNA control region sequences and seven microsatellites were used to estimate the genetic structuring, evolutionary history and historic migration patterns of the kob antelope (Kobus kob). Ten populations were analysed, representing the three recognized K. kob subspecies: K. k. kob in west Africa, K. k. thomasi in Uganda and K. k. leucotis in Sudan and Ethiopia. Despite being classified as K. k. thomasi and being phenotypically identical to the kob in Queen Elizabeth National Park (NP), the Murchison Falls population in Uganda showed high genetic similarity with the phenotypically distinct K. k. leucotis populations in Sudan and Ethiopia. This was regardless of marker type. Pairwise comparisons and genetic distances between populations grouped Murchison with K. k. leucotis, as did the Bayesian analysis, which failed to find any genetic structuring within the group. We propose that the divergent phenotype and life‐history adaptations of K. k. leucotis reflect the isolation of kob populations in refugia in west and east Africa during the Pleistocene. Subsequent dispersal has led to secondary contact and hybridization in northern Uganda between lineages, which was supported by high levels of genetic diversity in Murchison. The reduced variability observed in Queen Elizabeth NP reflects a small founder population from west Africa and in part the decimation of Uganda's wildlife during the country's political turmoil in the 1970s. Due to similarities in phenotype and ecology, and the joint evolutionary history of their mtDNA sequences, the taxonomic status of K. k. kob and K. k. thomasi as separate subspecies is called into question.
Delimiting species boundaries and the conservation genetics of the endangered maritime ringlet butterfly (Coenonympha nipisiquitMcDunnough)
Authors: SEI MAKIRI , PORTER ADAM H.
Published: July 2007

Species delimitation is a difficult problem that has implications across organismal biology, yet no single method has proved wholly satisfactory. We tested the utility of combining species‐delimitation methods based on phylogeny and gene flow statistics using two parapatric members of theCoenonympha tulliagroup as an example: the endangered maritime ringlet butterfly (Coenonympha nipisiquitMcDunnough) and the common inornate ringlet butterfly (Coenonympha inornataEdwards). We reconstructed the phylogeny of the nearcticC. tullia‐group taxa from mitochondrial DNA (mtDNA) sequences (cytochrome oxidase I and mitochondrial control region) to explore the ancestry of theC. nipisiquitlineage within the group. We investigated the extent of gene flow between the two taxa withF‐statistics using 587 nuclear amplified fragment length polymorphism markers, accounting for the effect of potential scoring ‘collisions’ where a marker may represent more than one DNA fragment. Combining species‐delimitation methods was especially effective because it uncovered both historical and recent evolutionary patterns. Phylogenetic analysis of mtDNA revealed the early divergence ofC. nipisiquitfrom otherC. tullia‐group taxa, including the morphologically similarC. inornata. F‐statistics and gene‐by‐gene introgression profiles demonstrated clear isolation between the two taxa and revealed strong population structure withinC. nipisiquit. C. nipisiquitis the first taxon in the nearcticC. tulliagroup showing strong evidence of genetic isolation. The methods we used are relatively inexpensive and can be widely used to delimit taxonomic boundaries near the species level, both generally and in particular for taxa that may be targets of conservation efforts.
Delimiting cohesion species: extreme population structuring and the role of ecological interchangeability
Authors: STOCKMAN AMY K. , BOND JASON E.
Published: July 2007

Species exhibiting morphological homogeneity and strong population structuring present challenging taxonomic problems: morphology‐based approaches infer few species, whereas genetic approaches often indicate more. Morphologically cryptic, yet genetically divergent species groups require alternative approaches to delimiting species that assess adaptive divergence and ecological interchangeability of lineages. We apply such an approach toPromyrmekiaphila, a small genus (three nominal taxa) of trapdoor spiders endemic to northern California to define cohesion species (lineages that are genetically exchangeable and ecologically interchangeable). Genetic exchangeability is evaluated using standard phylogeographical techniques (e.g. nested clade analysis); ecological interchangeability is assessed using two GIS‐based approaches. First, climatic values are extracted from layer data for each locality point and utilized in a principal components analysis followed by MANOVA. Second, niche‐based distribution models of genetically divergent lineages are created using a maximum‐entropy modelling approach; the amount of overlap among lineages is calculated and evaluated against a probability distribution of null overlap. Lineages that have significant amounts of predicted overlap are considered ecologically interchangeable. Based on a synthetic evaluation of ecological interchangeability, geographical concordance, and morphological differentiation, we conclude thatPromyrmekiaphilacomprises six cohesion species, five of which are cryptic (i.e. undetectable by conventional means).
Involvement of a periplasmic protein kinase in DNA strand break repair and homologous recombination in Escherichia coli
Authors: Khairnar Nivedita P. , Kamble Vidya A. , Mangoli Suhas H. , Apte Shree K. , Misra Hari S.
Published: July 2007

The involvement of signal transduction in the repair of radiation‐induced damage to DNA has been known in eukaryotes but remains understudied in bacteria. This article for the first time demonstrates a role for the periplasmic lipoprotein (YfgL) with protein kinase activity transducing a signal for DNA strand break repair in Escherichia coli. Purified YfgL protein showed physical as well as functional interaction with pyrroloquinoline‐quinone in solution and the protein kinase activity of YfgL was strongly stimulated in the presence of pyrroloquinoline‐quinone. Transgenic E. coli cells producing Deinococcus radiodurans pyrroloquinoline‐quinone synthase showed nearly four log cycle improvement in UVC dark survival and 10‐fold increases in gamma radiation resistance as compared with untransformed cells. Pyrroloquinoline‐quinone enhanced the UV resistance of E. coli through the YfgL protein and required the active recombination repair proteins. The yfgL mutant showed higher sensitivity to UVC, mitomycin C and gamma radiation as compared with wild‐type cells and showed a strong impairment in homologous DNA recombination. The mutant expressing an active YfgL in trans recovered the lost phenotypes to nearly wild‐type levels. The results strongly suggest that the periplasmic phosphoquinolipoprotein kinase YfgL plays an important role in radiation‐induced DNA strand break repair and homologous recombination in E. coli.
Mutation of a key residue in the type II secretion system ATPase uncouples ATP hydrolysis from protein translocation
Authors: Shiue Sheng‐Jie , Chien I‐Ling , Chan Nei‐Li , Leu Wei‐Ming , Hu Nien‐Tai
Published: July 2007

Membrane‐associated ATPase constitutes an essential element common to all secretion machineries in Gram‐negative bacteria. How ATP hydrolysis by these ATPases is coupled to secretion process remains unclear. Here we identified R286 as a key residue in the type II secretion system (T2SS) ATPase XpsE of Xanthomonas campestris that plays a pivotal role in coupling ATP hydrolysis to protein translocation. Mutation of R286 to alanine made XpsE hydrolyse ATP at a rate five times that of the wild‐type XpsE. Yet the mutant XpsE(R286A) is non‐functional in protein secretion via T2SS. Detailed analyses indicated that the mutant XpsE(R286A) lost the ability co‐ordinating the N‐ and C‐domain of XpsE. Without significantly influencing XpsE binding affinity with ATP or its oligomerization, R286A mutation however, caused XpsE lose the ability to associate with the cytoplasmic membrane via XpsLN. As a consequence, ATP hydrolysis by XpsE was uncoupled from protein secretion. Because R286 is highly conserved among members of the secretion NTPase superfamily, we speculate that its equivalent in other homologues may also play a critical energy coupling role for T2SS, type IV pilus assembly and type IV secretion system.
The multiple roles of CRP at the complex acs promoter depend on activation region 2 and IHF
Authors: Sclavi Bianca , Beatty Christine M. , Thach David S. , Fredericks Christine E. , Buckle Malcolm , Wolfe Alan J.
Published: July 2007

acs encodes a high‐affinity enzyme that permits survival during carbon starvation. As befits a survival gene, its transcription is subject to complex regulation. Previously, we reported that cAMP receptor protein (CRP) activates acs transcription by binding tandem DNA sites located upstream of the major acsP2 promoter and that the nucleoid protein IHF (integration host factor) binds three specific sites located just upstream. In vivo, the sequence that includes these IHF sites exerts a positive effect on CRP‐dependent transcription, while a construct containing only the most proximal site exhibits reduced transcription compared with the full‐length promoter or with a construct lacking all three IHF sites. Here, we defined the minimal system required for this IHF‐dependent inhibition, showing it requires the promoter‐distal CRP site and an amino acid residue located within activation region 2 (AR2), a surface determinant of CRP that interacts with RNA polymerase (RNAP). Surprisingly, for a Class III promoter, disruption of AR2 caused significant changes in the activity and structure of both the full‐length promoter and the construct with the single proximal IHF site. We propose that AR2, together with IHF, mediates formation of a multi‐protein complex, in which RNAP is stabilized in an open complex that remains poised on the promoter ready to respond rapidly to environmental changes.
Signal integration in the galactose network of Escherichia coli
Authors: Semsey Szabolcs , Krishna Sandeep , Sneppen Kim , Adhya Sankar
Published: July 2007

The gal regulon of Escherichia coli contains genes involved in galactose transport and metabolism. Transcription of the gal regulon genes is regulated in different ways by two iso‐regulatory proteins, Gal repressor (GalR) and Gal isorepressor (GalS), which recognize the same binding sites in the absence of d‐galactose. DNA binding by both GalR and GalS is inhibited in the presence of d‐galactose. Many of the gal regulon genes are activated in the presence of the adenosine cyclic‐3′,5′‐monophosphate (cAMP)–cAMP receptor protein (CRP) complex. We studied transcriptional regulation of the gal regulon promoters simultaneously in a purified system and attempted to integrate the two small molecule signals, d‐galactose and cAMP, that modulate the isoregulators and CRP respectively, at each promoter, using Boolean logic. Results show that similarly organized promoters can have different input functions. We also found that in some cases the activity of the promoter and the cognate gene can be described by different logic gates. We combined the transcriptional network of the galactose regulon, obtained from our experiments, with literature data to construct an integrated map of the galactose network. Structural analysis of the network shows that at the interface of the genetic and metabolic network, feedback loops are by far the most common motif.
Multiple interactions among the competence proteins of Bacillus subtilis
Authors: Kramer Naomi , Hahn Jeanette , Dubnau David
Published: July 2007

Proteins required for transformation of Bacillus subtilis and other competent bacteria are associated with the membrane or reside in the cytosol. Previous work has shown that RecA, ComGA, ComFA and SsbB are directed to the cell poles in competent cells, and that the uptake of transforming DNA occurs preferentially at the poles. We show that ComGA, ComFA, DprA (Smf), SsbB (YwpH), RecA and YjbF (CoiA) are located at the cell poles, where they appear to colocalize. Using fluorescence resonance energy transfer, we have shown that these six competent (Com) proteins reside in close proximity to one another. This conclusion was supported by the effects of com gene knockouts on the stabilities of Com proteins. Data obtained from the com gene knockout studies, as well as information from other sources, extend the list of proteins in the transformation complex to include ComEC and ComEA. Because ComGA and ComFA are membrane‐associated, while DprA, SsbB, RecA and YjbF are soluble, a picture emerges of a large multiprotein polar complex, involving both cytosolic and membrane proteins. This complex mediates the binding and uptake of single‐stranded DNA, the protection of this DNA from cellular nucleases and its recombination with the recipient chromosome.
EfeUOB (YcdNOB) is a tripartite, acid‐induced and CpxAR‐regulated, low‐pH Fe2+ transporter that is cryptic in Escherichia coli K‐12 but functional in E. coli O157:H7
Authors: Cao Jieni , Woodhall Mark R. , Alvarez Javier , Cartron Michaël L. , Andrews Simon C.
Published: July 2007

Escherichia coli possesses iron transporters specific for either Fe2+ or Fe3+. Although Fe2+ is far more soluble than Fe3+, it rapidly oxidizes aerobically at pH ≥ 7. Thus, FeoAB, the major Fe2+ transporter of E. coli, operates anaerobically. However, Fe2+ remains stable aerobically under acidic conditions, although a low‐pH Fe2+ importer has not been previously identified. Here we show that ycdNOB (efeUOB) specifies the first such transporter. efeUOB is repressed at high pH by CpxAR, and is Fe2+–Fur repressed. EfeU is homologous to the high‐affinity iron permease, Ftr1p, of Saccharomyces cerevisiae and other fungi. EfeO is periplasmic with a cupredoxin N‐terminal domain; EfeB is also periplasmic and is haem peroxidase‐like. All three Efe proteins are required for Efe function. The efeU gene of E. coli K‐12 is cryptic due to a frameshift mutation – repair of the single‐base‐pair deletion generates a functional EfeUOB system. In contrast, the efeUOB operon of the enterohaemorrhagic strain, O157:H7, lacks any frameshift and is functional. A ‘wild‐type’ K‐12 strain bearing a functional EfeUOB displays a major growth advantage under aerobic, low‐pH, low‐iron conditions when a competing metal is provided. 55Fe transport assays confirm the ferrous iron specificity of EfeUOB.
Deletion of putative apoptosis factors leads to lifespan extension in the fungal ageing model Podospora anserina
Authors: Hamann Andrea , Brust Diana , Osiewacz Heinz D.
Published: July 2007

Podospora anserina is a filamentous fungus with a limited lifespan. After a strain‐specific period of growth, cultures turn to senescence and ultimately die. Here we provide evidence that the last step in the ageing of P. anserina is not accidental but programmed. In this study, PaAMID1, a homologue of a mammalian ‘AIF‐homologous mitochondrion‐associated inducer of death’, was analysed as a putative member of a caspase‐independent signalling pathway. In addition, two metacaspases, PaMCA1 and PaMCA2, were investigated. While deletion of PaAmid1 as well as of PaMca2 was found to result in a moderate lifespan extension (59% and 78%, respectively), a 148% increase in lifespan was observed after deletion of PaMca1. Measurement of arginine‐specific protease activity demonstrates a metacaspase‐dependent activity in senescent but not in juvenile cultures, pointing to an activation of these proteases in the senescent stage of the life cycle. Moreover, treatment of juvenile wild‐type cultures with hydrogen peroxide leads to a PaMCA1‐dependent activity. The presented data strongly suggest that death of senescent wild‐type cultures is triggered by an apoptotic programme induced by an age‐dependent increase of reactive oxygen species during ageing of cultures and is executed after metacaspase activation.
Stromal haze after combined riboflavin‐UVA corneal collagen cross‐linking in keratoconus: in vivo confocal microscopic evaluation
Authors: Mazzotta Cosimo , Balestrazzi Angelo , Baiocchi Stefano , Traversi Claudio , Caporossi Aldo
Published: July 2007

Abstract

The technique of corneal collagen cross‐linking consists of photopolymerization of stromal fibres by the combined action of a photosensitizing substance (riboflavin or vitamin B2) and ultraviolet light from a solid state UVA source. Photopolymerization increases the rigidity of corneal collagen and its resistance to keratectasia. In this report we present two cases, studied through in vivo confocal microscopy, with stage III keratoconus that developed stromal haze after the cross‐linking treatment.
THE IMF: A BIRD'S EYE VIEW OF ITS ROLE AND OPERATIONS
Authors: Bird Graham
Published: July 2007

Abstract The International Monetary Fund (IMF) is the world's premier international financial institution with 184 member countries and active programmes in a significant number of them at any one time. The Fund attracts a great deal of attention, much of it critical. But the discussion is often polemic in style. Strongly held, but frequently opposing, views are expressed. This survey attempts to examine, in an objective way, the theory and evidence relating to the Fund's operations. Many aspects of the empirical research are relatively recent and a universal consensus is yet to emerge; as a consequence there is scope for disagreement to persist. However, the research is also gradually clarifying many important issues. The format for the survey is to examine the life cycle of IMF arrangements. What makes a country turn to the Fund for assistance? Should the IMF be lending? What influences the outcome of negotiations and the design of programmes? Are IMF programmes effective? And why do some countries make prolonged use of IMF resources? For completeness there is also some discussion of the history of the IMF, the extent to which Fund policies have been influenced by advances in economic theory and the Fund's systemic role. Important organisational and governance issues are also covered briefly. Although primarily adopting an economist's perspective, the survey reflects the growing recognition that in order to understand the IMF's operations, economics has to be combined with politics. Examining the IMF is an exercise in applied political economy.
WHAT DO WE KNOW ABOUT THE PROFITABILITY OF TECHNICAL ANALYSIS?
Authors: Park Cheol‐Ho , Irwin Scott H.
Published: July 2007

Abstract The purpose of this paper is to review the evidence on the profitability of technical analysis. The empirical literature is categorized into two groups, ‘early’ and ‘modern’ studies, according to the characteristics of testing procedures. Early studies indicate that technical trading strategies are profitable in foreign exchange markets and futures markets, but not in stock markets. Modern studies indicate that technical trading strategies consistently generate economic profits in a variety of speculative markets at least until the early 1990s. Among a total of 95 modern studies, 56 studies find positive results regarding technical trading strategies, 20 studies obtain negative results, and 19 studies indicate mixed results. Despite the positive evidence on the profitability of technical trading strategies, most empirical studies are subject to various problems in their testing procedures, e.g. data snooping, ex post selection of trading rules or search technologies, and difficulties in estimation of risk and transaction costs. Future research must address these deficiencies in testing in order to provide conclusive evidence on the profitability of technical trading strategies.
MARGINAL COMMODITY TAX REFORMS: A SURVEY
Authors: Santoro Alessandro
Published: July 2007

AbstractAs noted 30 years ago by Martin Feldstein, optimal taxes may be useless for practical purposes and emphasis should instead be placed on the possibility of enhancing welfare by reforming existing tax rates. In this perspective, marginal commodity tax reforms are gaining increasing attention due to political and economic constraints on large reforms of direct (or indirect) taxation. In this paper, we summarize the main features and results of the literature on marginal commodity tax reforms pioneered by Ahmad and Stern, further developed by Yitzhaki and Thirsk and recently reinterpreted by Makdissi and Wodon. We establish new links to other fields of research, namely the literature on the use of equivalence scales and on poverty measurement. We also critically examine some issues associated with the implementation of marginal tax reforms with special reference to the calculation of welfare weights and revenue effects. Finally, we suggest directions for future research on poverty‐reducing commodity tax reforms.
Conditions for young infants’ failure to perceive trajectory continuity
Authors: Bremner J. Gavin , Johnson Scott P. , Slater Alan , Mason Uschi , Cheshire Andrea , Spring Joanne
Published: July 2007

When viewing an event in which an object moves behind an occluder on part of its trajectory, 4‐month‐old infants perceive the trajectory as continuous only when time or distance out of sight is short. Little is known, however, about the conditions under which young infants perceive trajectories to be discontinuous. In the present studies we focus first on infants’ perception of trajectories that change during a period of occlusion. Four‐month‐olds perceive discontinuity in trajectories that change in height or orientation while behind an occluder, and this is true even when a change in direction could be due to an invisible bouncing collision with a surface. Further experiments reveal that infants do not perceive diagonal linear trajectories as continuous across an occlusion unless the occluding and revealing edges are orthogonal to the path of movement. Implications for theories of perceptual and cognitive development are discussed.
Using cardinality to compare quantities: the role of social‐cognitive conflict in early numeracy
Authors: Muldoon Kevin P. , Lewis Charlie , Francis Brian
Published: July 2007

A key question in early number development is how 4‐ and 5‐year‐olds learn the roles that counting and cardinal numbers play when comparing quantities. Children who wrongly used length to identify numerosity were assigned to five experimental groups and trained to judge whether a puppet – who sometimes miscounted – created equivalent sets. Over three training sessions, children who were asked to compare sets after they were counted learned to base their judgments on cardinal numbers when the puppet counted accurately by being given feedback. However, only the groups who were also asked to explain either their own or the experimenter's reasoning made progress in identifying the puppet's miscounts. This ability to recognize the importance of counting accuracy for quantitative comparisons predicted whether children would spontaneously count to compare sets on a post‐test. The importance of asking children to identify miscounts is discussed alongside the social factors that influence children's recognition of the relationship between procedural counting, cardinality and relative number.
Maturation of the long‐latency auditory ERP: step function changes at start and end of adolescence
Authors: Bishop Dorothy V.M. , Hardiman Mervyn , Uwer Ruth , Von Suchodoletz Waldemar
Published: July 2007

The auditory event‐related potential (ERP) is obtained by averaging electrical impulses recorded from the scalp in response to repeated stimuli. Previous work has shown large differences between children, adolescents and adults in the late auditory ERP, raising the possibility that analysis of waveform shape might be useful as an index of brain maturity. We reanalysed auditory ERPs from samples previously described by Albrecht, von Suchodoletz and Uwer (2000) and Uwer, Albrecht and von Suchodoletz (2002), using the intraclass correlation (ICC) as a global measure of similarity of an individual's waveform to a grand average comparison waveform for each age band. Three developmental periods were clearly distinguished: 5 to 12 years, 13 to 16 years, and adulthood. However, within each of these periods, there was no evidence of any developmental progression with age.
No agreement between the Rorschach and self‐assessed personality traits derived from the Comprehensive System
Authors: LINDGREN THOMAS , CARLSSON ANNA MARIA , LUNDBÄCK EVA
Published: July 2007

Eighty psychiatric patients with different clinical diagnoses completed the Rorschach (Exner, 1993), the MMPI‐2 (Butcher et al., 1989) and also rated 51 written personality descriptions derived from the Comprehensive System (SAPCS). The 51 self‐descriptions were constructed by the authors with the objective to achieve maximum overlap with the interpretive guidelines suggested for Rorschach Comprehensive System (RCS) variables, while simultaneously fitting with how patients could be expected to describe themselves in self‐rating. With evidence of (1) independent judges’ ability to correct classification of the items, (2) item test‐retest stability, (3) sensitivity and specificity, measuring psychological adaptive capacity and vulnerability/pathology, and (4) item inter‐correlation with the MMPI‐2, patient's SAPCS ratings were expected to significantly converge with corresponding RCS measures. However, including all variable pairings, the mean correlation suggests that SAPCS statements overlapping with RCS interpretive statements do not measure the same constructs as the RCS variables to which the interpretive statements are referring. Standard validity scales in the MMPI‐2 and first factor‐related test interaction style did not predictably moderate the relation between RCS indices and the RCS‐near self descriptions.
Who in Brazil Will Gain from Global Trade Reforms?
Authors: Azzoni Carlos , Brooks Jonathan , Guilhoto Joaquim , McDonald Scott
Published: July 2007

The potential impacts of multilateral trade liberalisation on developing countries are the subject of numerous controversies. One particular concern is that Brazil, a major agricultural exporter and a country with one of the world's most unequal income distributions, will reap a substantial share of the potential benefits to developing countries from agricultural trade reform, and that most of those benefits will go to large‐scale commercial farmers rather than to the country's smallholders. This claim is explored via a global general equilibrium model and a national model of Brazil containing multiple agricultural and non‐agricultural households. Brazil is found to account for nearly one‐half of all the benefits to developing countries deriving from global agricultural trade reform. These gains are associated with improvements in the welfare of each group and a lower incidence of poverty. Large‐scale producers gain more than smallholders as they tend to be relatively specialised in export products, but there are important gains to agricultural employees, who are relatively poor, and to urban households, who benefit from the expansion of the agro‐food sector. Overall, there is no discernible impact on income inequality, and no evidence that the gains to commercial farmers occur at the expense of poorer households.
Understanding Developing Country Strategic Responses to the Enhancement of Food Safety Standards
Authors: Henson Spencer , Jaffee Steven
Published: July 2007

This paper explores the competing concepts of ‘standards as barriers’ and ‘standards as catalysts’ in the context of food safety standards in international trade in agricultural and food products. Through a review of existing evidence of the impact of food safety standards on developing country exports of agricultural and food products and the results of a series of country‐ and product‐specific case studies, it is suggested that food safety standards can act as both a barrier to trade and the basis of competitive positioning for developing countries in international markets. This suggests that broad conclusions about the trade effects of food safety standards on developing countries are problematic, rather the level and ways in which agricultural and food exports are impacted can be product, country, standard and even firm‐specific.
An analysis of nucleotide and amino acid variability in the barcode region of cytochromecoxidase I (cox1) in fishes
Authors: WARD ROBERT D. , HOLMES BRONWYN H.
Published: July 2007

The 655 bp cytochromecoxidase subunit I barcode region of single specimens of 388 species of fishes (four Holocephali, 61 Elasmobranchii and 323 Actinopterygii) was examined. All but two (Urolophus cruciatusandUrolophus sufflavus) showed differentcox1nucleotide sequences (99.5% species discrimination); the two that could not be resolved are suspected to hybridize. Most of the power ofcox1nucleotide sequence analysis for species identification comes from the degenerate nature of the genetic code and the highly variable nature of the third codon position of amino acids. Variation at the third codon position is bimodally distributed, and the more variable mode is dominated by amino acids with four or six codons, while the less variable mode is dominated by amino acids with two codons. The ratio of nonsynonymous to synomymous changes is much less than one, indicating that this gene is subject to strong purifying selection. Consequently,cox1amino acid sequence diversity is much less than nucleotide sequence diversity and has very poor species resolution power. Fourteen of the 16 amino acid residues recognized as having important functions in the region ofcox1sequenced were completely conserved over all 388 species (and the bovinecox1sequence), with one fish species varying at one of these sites, and three fish at another site. No significant differences in amino acid conservation were observed between residues in helices, strands and turns. Patterns of nucleotide and amino acid variability were very similar between elasmobranchs and actinopterygians.
Characterization of microsatellite markers in mandarin orange (Citrus reticulata Blanco)
Authors: FROELICHER Y. , DAMBIER D. , BASSENE J. B. , COSTANTINO G. , LOTFY S. , DIDOUT C. , BEAUMONT V. , BROTTIER P. , RISTERUCCI A. M. , LURO F. , OLLITRAULT P.
Published: July 2007

A dinucleotide‐enriched genomic library was obtained from mandarin orange (Citrus reticulata Blanco). A subset of 101 positive clones was sequenced and primers were designed. The loci were screened for levels of variation using 26–29 wild mandarin oranges collected in Vietnam. Forty‐three loci were polymorphic with the number of alleles ranging from two to 18. The observed heterozygosity (HO) and expected heterozygosity (HE) were from 0.03 to 0.96 and from 0.03 to 0.92, respectively.