Discovery of the Elusive UDP-Diacylglucosamine Hydrolase in the Lipid A Biosynthetic Pathway in Chlamydia trachomatis.

Constitutive biosynthesis of lipid A via the Raetz pathway is essential for the viability and fitness of Gram-negative bacteria, includingChlamydia trachomatis Although nearly all of the enzymes in the lipid A biosynthetic pathway are highly conserved across Gram-negative bacteria, the cleavage of the pyrophosphate group of UDP-2,3-diacyl-GlcN (UDP-DAGn) to form lipid X is carried out by two unrelated enzymes: LpxH in beta- and gammaproteobacteria and LpxI in alphaproteobacteria. The intracellular pathogenC. trachomatislacks an ortholog for either of these two enzymes, and yet, it synthesizes lipid A and exhibits conservation of genes encoding other lipid A enzymes. Employing a complementation screen against aC. trachomatisgenomic library using a conditional-lethallpxHmutantEscherichia colistrain, we have identified an open reading frame (Ct461, renamedlpxG) encoding a previously uncharacterized enzyme that complements the UDP-DAGn hydrolase function inE. coliand catalyzes the conversion of UDP-DAGn to lipid Xin vitro LpxG shows little sequence similarity to either LpxH or LpxI, highlighting LpxG as the founding member of a third class of UDP-DAGn hydrolases. Overexpression of LpxG results in toxic accumulation of lipid X and profoundly reduces the infectivity ofC. trachomatis, validating LpxG as the long-sought-after UDP-DAGn pyrophosphatase in this prominent human pathogen. The complementation approach presented here overcomes the lack of suitable genetic tools forC. trachomatisand should be broadly applicable for the functional characterization of other essentialC. trachomatisgenes.IMPORTANCEChlamydia trachomatisis a leading cause of infectious blindness and sexually transmitted disease. Due to the lack of robust genetic tools, the functions of manyChlamydiagenes remain uncharacterized, including the essential gene encoding the UDP-DAGn pyrophosphatase activity for the biosynthesis of lipid A, the membrane anchor of lipooligosaccharide and the predominant lipid species of the outer leaflet of the bacterial outer membrane. We designed a complementation screen against theC. trachomatisgenomic library using a conditional-lethal mutant ofE. coliand identified the missing essential gene in the lipid A biosynthetic pathway, which we designatedlpxG We show that LpxG is a member of the calcineurin-like phosphatases and displays robust UDP-DAGn pyrophosphatase activityin vitro Overexpression of LpxG inC. trachomatisleads to the accumulation of the predicted lipid intermediate and reduces bacterial infectivity, validating thein vivofunction of LpxG and highlighting the importance of regulated lipid A biosynthesis inC. trachomatis.

The Legacy of Oboist and Master Teacher, Robert Bloom

Robert Bloom (1908-1994) was legendary in the education and performance world. Often hailed as one of the last performers of the Golden Era of classical music and a favorite of conductors ranging from Stokowski to Stravinsky to Shaw, Bloom was an orchestral oboist and English hornist, oboe soloist, chamber musician, teacher (Eastman, Yale, Hartt, Manhattan School of Music, Juilliard and Philadelphia's University of the Arts), composer, conductor, editor of masterworks of the 18th century, and, as a founding member of the Bach Aria group, a seminal influence in the post-WWII revival of Baroque music in America. In The Robert Bloom Collection and the Art of Robert Bloom CD and video archives, we see what his musical ideals were in 1)18th-century performance practices, 2) writing new music for the instrument and commissioning new works, and 3) and transcribing music for the oboe and English horn. As an oboist, I believe it is important that Bloom's teachings, historical performance practices and ideas for expanding repertoire are propagated. Therefore, the works chosen for this dissertation illustrated this legacy. My recitals included 1) some of Bloom's published 18th-century baroque elaborations (his term for ornamentation), as well Baroque works which I have elaborated, 2) works written by him and by other oboists/composers (Labate, Roseman) as well as a flute/oboe duo that I commissioned by Dr. Marcus Maroney and 3) transcriptions by both Bloom and myself (Bach, Donizetti, Mendelssohn, Mozart, Handel, Schumann and Telemann). In these three dissertation recitals, I hope to have illustrated some of Robert Bloom's lasting contributions and impact on the oboe world, and to have demonstrated the potential for carrying forward this legacy by studying his teaching and emulating his example.

The Jama legal narrative. Part II: A foray into concepts of improbability

In judicial decision making, the doctrine of chances takes explicitly into account the odds. There is more to forensic statistics, as well as various probabilistic approaches which taken together form the object of an enduring controversy in the scholarship of legal evidence. In this paper, we reconsider the circumstances of the Jama murder and inquiry (dealt with in Part I of this paper: "The Jama Model. On Legal Narratives and Interpretation Patterns"), to illustrate yet another kind of probability or improbability. What is improbable about the Jama story, is actually a given, which contributes in terms of dramatic underlining. In literary theory, concepts of narratives being probable or improbable date back from the eighteenth century, when both prescientific and scientific probability was infiltrating several domains, including law. An understanding of such a backdrop throughout the history of ideas is, I claim, necessary for AI researchers who may be tempted to apply statistical methods to legal evidence. The debate for or against probability (and especially bayesian probability) in accounts of evidence has been flouishing among legal scholars. Nowadays both the the Bayesians (e.g. Peter Tillers) and Bayesioskeptics (e.g. Ron Allen) among those legal scholars whoare involved in the controversy are willing to give AI researchers a chance to prove itself and strive towards models of plausibility that would go beyond probability as narrowly meant. This debate within law, in turn, has illustrious precedents: take Voltaire, he was critical of the application or probability even to litigation in civil cases; take Boole, he was a starry-eyed believer in probability applications to judicial decision making (Rosoni 1995). Not unlike Boole, the founding father of computing, nowadays computer scientists approaching the field may happen to do so without full awareness of the pitfalls. Hence, the usefulness of the conceptual landscape I sketch here.

The Jama legal narrative part II: A foray into concepts of improbability

In judicial decision making, the doctrine of chances takes explicitly into account the odds. There is more to forensic statistics, as well as various probabilistic approaches, which taken together form the object of an enduring controversy in the scholarship of legal evidence. In this paper, I reconsider the circumstances of the Jama murder and inquiry (dealt with in Part I of this paper: 'The JAMA Model and Narrative Interpretation Patterns'), to illustrate yet another kind of probability or improbability. What is improbable about the Jama story is actually a given, which contributes in terms of dramatic underlining. In literary theory, concepts of narratives being probable or improbable date back from the eighteenth century, when both prescientific and scientific probability were infiltrating several domains, including law. An understanding of such a backdrop throughout the history of ideas is, I claim, necessary for Artificial Intelligence (AI) researchers who may be tempted to apply statistical methods to legal evidence. The debate for or against probability (and especially Bayesian probability) in accounts of evidence has been flourishing among legal scholars; nowadays both the Bayesians (e.g. Peter Tillers) and the Bayesio-skeptics (e.g. Ron Allen), among those legal scholars who are involved in the controversy, are willing to give AI research a chance to prove itself and strive towards models of plausibility that would go beyond probability as narrowly meant. This debate within law, in turn, has illustrious precedents: take Voltaire, he was critical of the application of probability even to litigation in civil cases; take Boole, he was a starry-eyed believer in probability applications to judicial decision making. Not unlike Boole, the founding father of computing, nowadays computer scientists approaching the field may happen to do so without full awareness of the pitfalls. Hence, the usefulness of the conceptual landscape I sketch here.

What students can tell about lecturers when they are teaching: manifestations of confident and under-confident lecturers

Delivering a lecture requires confidence, a sound knowledge and well developed teaching skills (Cooper and Simonds, 2007, Quinn and Hughes, 2007). However, practitioners who are new to lecturing large groups in higher education may initially lack the confidence to do so which can manifest itself in their verbal and non-verbal cues and the fluency of their teaching skills. This results in the perception that students can identify the confident and non-confident teacher during a lecture (Street, 2007) and so potentially contributing to a lecturer’s level of anxiety prior to, and during, a lecture. Therefore, in the current educational climate of consumerisation, with the increased evaluation of teaching by students, having the ability to deliver high-quality, informed, and interesting lectures assumes greater significance for both lecturers and universities (Carr, 2007; Higher Education Founding Council 2008, Glass et al., 2006). This paper will present both the quantitative and qualitative data from a two-phase mixed method study with 75 nurse lecturers and 62 nursing students in one university in the United Kingdom. The study investigated the notion that lecturing has similarities to acting (Street, 2007). The findings presented here are concerned with how students perceived lecturers’ level of confidence and how lecturers believed they demonstrated confidence. In phase one a specifically designed questionnaire was distributed to both lecturers and students and a response rate of 91% (n=125) was achieved, while in phase two 12 in-depth semi-structured interviews were conducted with lecturers. Results suggested that students in a lecture could identify if the lecturer was confident or not by the way they performed a lecture. Students identified 57 manifestations of non-confidence and lecturers identified 85, while 57 manifestations of confidence were identified by students and 88 by lecturers. Overall, these fell into 12 main converse categories, ranging from body language to the use of space within the room. Both students and lecturers ranked body language, vocal qualities, delivery skills, involving the students and the ability to share knowledge as the most evident manifestations of confidence. Elements like good eye contact, smiling, speaking clearly and being fluent in the use of media recourses where all seen as manifestations confidence, conversely if these were poorly executed then a presentation of under confidence was evident. Furthermore, if the lecturer appeared enthusiastic it was clearly underpinned by the manifestation of a highly confidence lecturer who was secure in their knowledge base and teaching abilities: Some lecturers do appear enthusiastic but others don’t. I think the ones that do know what they are talking about, you can see it in their voice and in their lively body language. I think they are also good at involving the students even. I think the good ones are able to turn boring subjects into lively and interesting ones. (Student 50) Significantly more lecturers than students felt the lecturer should appear confident when lecturing. The lecturers stated it was particularly important to do so when they did not feel confident, because they were concerned with appearing capable. It seems that these students and lecturers perceived that expressive and apparently confident lecturers can make a positive impact on student groups in terms of involvement in lectures; the data also suggested the reverse, for the under confident lecturer. Findings from phase two indicated that these lecturers assumed a persona when lecturing, particularly, but not exclusively, when they were nervous. These lecturers went through a process of assuming and maintaining this persona before and during a lecture as a way of promoting their internal perceptions of confidence but also their outward manifestation of confidence. Although assuming a convincing persona may have a degree of deception about it, providing the knowledge communicated is accurate, the deception may aid rather than hinder learning, because enhances the delivery of a lecture. Therefore, the deception of acting a little more confidently than one feels might be justified when the lecturer knows the knowledge they are communicating is correct, unlike the Dr Fox Effect where the person delivering a lecture is an actor and does not know the subject in any detail or depth and where the deception to be justified (Naftulin, et al., 1973). In conclusion, these students and lecturers perceive that confident and enthusiastic lecturers communicate their passion for the subject in an interesting and meaningful manner through the use of their voice, body, space and interactions in such a way that shows confidence in their knowledge as well as their teaching abilities. If lecturers, therefore, can take a step back to consider how they deliver lectures in apparently confident ways this may increase their ability to engage their students and not only help them being perceived as good lecturers, but also contribute to the genuine act of education.

Simulating CO2 leakage into marine environments

Jerry Blackford of the Plymouth Marine Laboratory leads the UK Research Council funded Quantifying and Monitoring Potential Ecosystem Impacts of Geological Carbon Storage (QICS) program, and is a founding member of the new UK CCS Research Centre leading the environment research team. Here he talks to Muriel Cozier about how the world's first experiment to simulate a CO2 leak from underground storage in a marine environment will go a long way toward improving our understanding of a series of complex interactions.

It's good to be queen: classically eusocial colony structure and low worker fitness in an obligately eusocial sweat bee.

Lasioglossum malachurum, a bee species common across much of Europe, is obligately eusocial across its range but exhibits clear geographic variation in demography and social behaviour. This variation suggests that social interactions between queens and workers, opportunities for worker oviposition, and patterns of relatedness among nest mates may vary considerably, both within and among regions. In this study, we used three microsatellite loci with 12–18 alleles each to examine the sociogenetic structure of colonies from a population at Agios Nikolaos Monemvasias in southern Greece. These analyses reveal that the majority of colonies exhibit classical eusocial colony structure in which a single queen mated to a single male monopolizes oviposition. Nevertheless, we also detect low rates of multiqueen nest founding, occasional caste switching by worker-destined females, and worker oviposition of both gyne and male-producing eggs in the final brood. Previous evidence that the majority of workers show some ovarian development and a minority (17%) have at least one large oocyte contrasts with the observation that only 2–3% of gynes and males (the so-called reproductive brood) are produced by workers. An evaluation of the parameters of Hamilton's Rule suggests that queens benefit greatly from the help provided by workers but that workers achieve greater fitness by provisioning and laying their own eggs rather than by tending to the queen's eggs. This conflict of interest between the queen and her workers suggests that the discrepancy between potential and achieved worker oviposition is due to queen interference. Comparison of relatedness and maternity patterns in the Agios Nikolaos Monemvasias population with those from a northern population near Tübingen, Germany, points to a north–south cline of increasingly effective queen control of worker behaviour.

Education and the 'universalist' idiom of empire: Irish National School Books in Ireland and Ontario

This paper compares the founding of the elementary school systems of Ireland and Ontario in the nineteenth century. The systems shared a common set of textbooks that had originated in Ireland. Using examples from a number of these books, which were part of a series that had been specially prepared for the Irish national school system, founded in 1831, and information from archive sources on policy and administration in both countries, the paper argues that there was a common, ‘universalist’, imperialist ideology being promulgated in both systems. The article focuses on these ‘universalist’ principles rather than undertaking a detailed analysis of the textbooks.

AINT/ERIC/TACC: an expanding family of proteins with C-terminal coiled coil domains:an expanding family of proteins with C-terminal coiled coil domains

The AINT/ERIC/TACC genes encode novel proteins with a coiled coil domain at their C-terminus. The founding member of this expanding family of genes, transforming acidic coiled coil 1 (TACC1), was isolated from a BAC contig spanning the breast cancer amplicon-1 on 8p11. Transfection of cells in vitro with TACC1 resulted in anchorage-independent growth consistent with a more "neoplastic" phenotype. Database searches employing the human TACC1 sequence revealed other novel genes, TACC2 and TACC3, with substantial sequence homology particularly in the C-terminal regions encoding the coiled coil domains. TACC2, located at 10q26, is similar to anti-zuai-1 (AZU-1), a candidate breast tumour suppressor gene, and ECTACC, an endothelial cell TACC which is upregulated by erythropoietin (Epo). The murine homologue of TACC3, murine erythropoietin-induced cDNA (mERIC-1) was also found to be upregulated by Epo in the Friend virus anaemia (FVA) model by differential display-PCR. Human ERIC-1, located at 4p16.3, has been cloned and encodes an 838-amino acid protein whose N- and C-terminal regions are highly homologous to the shorter 558-amino acid murine protein, mERIC-1. In contrast, the central portions of these proteins differ markedly. The murine protein contains four 24 amino acid imperfect repeats. ARNT interacting protein (AINT), a protein expressed during embryonic development in the mouse, binds through its coiled coil region to the aryl hydrocarbon nuclear translocator protein (ARNT) and has a central portion that contains seven of the 24 amino acid repeats found in mERIC-1. Thus mERIC-1 and AINT appear to be developmentally regulated alternative transcripts of the gene. Most members of the TACC family discovered so far contain a novel nine amino acid putative phosphorylation site with the pattern [R/K]-X(3)-[E]-X(3)-Y. Genes with sequence homology to the AINT/ERIC/TACC family in other species include maskin in Xenopus, D-TACC in Drosophila and TACC4 in the rabbit. Maskin contains a peptide sequence conserved among eIF-4E binding proteins that is involved in oocyte development. D-TACC cooperates with another conserved microtubule-associated protein Msps to stabilise spindle poles during cell division. The diversity of function already attributed to this protein family, including both transforming and tumour suppressor properties, should ensure that a new and interesting narrative is about to unfold.

Civil society as a contested field of meanings

Purpose – During recent years, the concept of civil society, particularly global civil society, has come to the fore in both academia and policy circles. A key component of recent theoretical and policy research is the attempt to do international comparative research on the meaning of civil society. The purpose of this paper is to argue that the language and the terminology used to describe the agents of civil society are reflective of cultural and historical contexts of societies, have distinct meanings and cannot be used interchangeably.

Design/methodology/approach – In different national contexts, the key agents of civil society are referred to differently; nonprofit sector, voluntary and community sector, third sector and social economy. In comparative studies, scholars often list these concepts to indicate that they recognise that the agents of civil society are referred to differently in different societies. The article offers a socio-historical analysis of each concept. It is concluded that teasing out the differences, as well as the similarities, between the nonprofit sector, voluntary and community sector, third sector and social economy, is crucial to robust comparative research on civil society.

Findings – This paper exposes a number of limitations of each of the terminologies used to describe civil society. They all present a much more limiting notion of civil society than that proposed by the founding fathers. None seem to capture the range of civil associations in any society. Yet, assumptions are made that the terminologies used have similar meanings rather than attempting to clarify and define exactly what is being written or described. This is exacerbated by the interchangeable usage of nonprofit/third sector/community and voluntary sector/social economy. In order to progress beyond culturally specific understandings of civil society, it is necessary to examine the terminology used and how it emanates from a specific cultural and political context. Having a clear understanding of the language used and what it signifies is crucial to robust cross-national comparative research.

Originality/value – This paper examines context specific understandings of civil society and the terminology used to define it; a question not previously addressed. It is hoped that this article will generate much needed further debate on cross-national meanings of civil society.

The SDLP and the Europeanization of the Northern Ireland Problem

This article explores the various ways in which the Social Democratic and Labour Party (SDLP) has used Europe – as a source of financial aid, political support, ideas and inspiration – in its attempts to resolve the Northern Ireland conflict. In this, the piece considers the SDLP, not as a subject, but rather as an advocate of the Europeanization of the Northern Ireland problem. In particular, it looks at the role of John Hume, a founding member and later leader of the SDLP, who inculcated a strongly pro-European outlook within the party. In doing so, the article considers the success of Hume and the SDLP in their efforts to bring a European influence to bear on Northern Ireland, especially in relation to the peace process and the 1998 Agreement. However, it also looks at both the limitations of this influence, and the problems involved with the SDLP's pro-European approach, particularly since Hume's departure as party leader in 2001. In conclusion, the article suggests that the party may have been ‘over-Europeanized’, with its long-term focus on European issues and ideas now becoming electorally disadvantageous. In this way, the Europeanization of the Northern Ireland problem, and by extension the SDLP, has proven costly to the party.

Functional Interleukin-17 Receptor A is Expressed in Central Nervous System Glia and Upregulated in Experimental Autoimmune Encephalomyelitis

Background: Interleukin-17A (IL-17A) is the founding member of a novel family of inflammatory cytokines that plays a critical role in the pathogenesis of many autoimmune diseases, including multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). IL-17A signals through its receptor, IL-17RA, which is expressed in many peripheral tissues; however, expression of IL-17RA in the central nervous system (CNS) and its role in CNS inflammation are not well understood. Methods: EAE was induced in C57Bl/6 mice by immunization with myelin oligodendroglial glycoprotein. IL-17RA expression in the CNS was compared between control and EAE mice using RT-PCR, in situ hybridization, and immunohistochemistry. Cell-type specific expression was examined in isolated astrocytic and microglial cell cultures. Cytokine and chemokine production was measured in IL-17A treated cultures to evaluate the functional status of IL-17RA. Results: Here we report increased IL-17RA expression in the CNS of mice with EAE, and constitutive expression of functional IL-17RA in mouse CNS tissue. Specifically, astrocytes and microglia express IL-17RA in vitro, and IL-17A treatment induces biological responses in these cells, including significant upregulation of MCP-1, MCP-5, MIP-2 and KC chemokine secretion. Exogenous IL-17A does not significantly alter the expression of IL-17RA in glial cells, suggesting that upregulation of chemokines by glial cells is due to IL-17A signaling through constitutively expressed IL-17RA. Conclusion: IL-17RA expression is significantly increased in the CNS of mice with EAE compared to healthy mice, suggesting that IL-17RA signaling in glial cells can play an important role in autoimmune inflammation of the CNS and may be a potential pathway to target for therapeutic interventions. © 2009 Sarma et al; licensee BioMed Central Ltd.

Scale of production and choice of technique in the engineering industries in developing countries

This article examines the relationship between scale of production, optimal choice of technique and costs for three engineering industries: nuts and bolts, iron founding and machine tools. In all three industries costs of production fell as the scale of output increased. This was associated with switches of technique and the spread of fixed costs over a larger number of units. The capital-output ratio fell and labour productivity increased with increases in scale while, in most cases, the capital-labour ratio increased. The implications of these findings are briefly discussed.

Rapid sympatric ecological differentiation of crater lake cichlid fishes within historic times

Background: After a volcano erupts, a lake may form in the cooled crater and become an isolated aquatic ecosystem. This makes fishes in crater lakes informative for understanding sympatric evolution and ecological diversification in barren environments. From a geological and limnological perspective, such research offers insight about the process of crater lake ecosystem establishment and speciation. In the present study we use genetic and coalescence approaches to infer the colonization history of Midas cichlid fishes (Amphilophus cf. citrinellus) that inhabit a very young crater lake in Nicaragua-the ca. 1800 year-old Lake Apoyeque. This lake holds two sympatric, endemic morphs of Midas cichlid: one with large, hypertrophied lips (~20% of the total population) and another with thin lips. Here we test the associated ecological, morphological and genetic diversification of these two morphs and their potential to represent incipient speciation.
Results: Gene coalescence analyses [11 microsatellite loci and mitochondrial DNA (mtDNA) sequences] suggest that crater lake Apoyeque was colonized in a single event from the large neighbouring great lake Managua only about 100 years ago. This founding in historic times is also reflected in the extremely low nuclear and mitochondrial genetic diversity in Apoyeque. We found that sympatric adult thin- and thick-lipped fishes occupy distinct ecological trophic niches. Diet, body shape, head width, pharyngeal jaw size and shape and stable isotope values all differ significantly between the two lip-morphs. The eco-morphological features pharyngeal jaw shape, body shape, stomach contents and stable isotopes (d15N) all show a bimodal distribution of traits, which is compatible with the expectations of an initial stage of ecological speciation under disruptive selection. Genetic differentiation between the thin- and thick-lipped population is weak at mtDNA sequence (FST = 0.018) and absent at nuclear microsatellite loci (FST < 0.001).
Conclusions: This study provides empirical evidence of eco-morphological differentiation occurring very quickly after the colonization of a new and vacant habitat. Exceptionally low levels of neutral genetic diversity and inference from coalescence indicates that the Midas cichlid population in Apoyeque is much younger (ca. 100 years or generations old) than the crater itself (ca. 1 800 years old). This suggests either that the crater remained empty for many hundreds of years after its formation or that remnant volcanic activity prevented the establishment of a stable fish population during the early life of the crater lake. Based on our findings of eco-morphological variation in the Apoyeque Midas cichlids, and known patterns of adaptation in Midas cichlids in general, we suggest that this population may be in a very early stage of speciation (incipient species), promoted by disruptive selection and ecological diversification.

CCN3-A key regulator of the hematopoietic compartment

CCN3, a founding member of the CCN family of growth regulators, was linked with hematology in 2003(1) when it was detected in human serum. CCN3 is expressed and secreted by hematopoietic progenitor cells in normal bone marrow. CCN3 acts through the core stem cell signalling pathways including Notch and Bone Morphogenic Protein, connecting CCN3 with the modulation of self-renewal and maturation of a number of cell lineages including hematopoietic, osteogenic and chondrogenic. CCN3 expression is disrupted in Chronic Myeloid Leukemia as a consequence of the BCR-ABL oncogene and allows the leukemic clone to evade growth regulation. In contrast, naive cord blood progenitors undergo enhanced clonal expansion in response to CCN3. Altered CCN3 expression is associated with numerous solid tumors including glioblastoma, melanoma. adrenocortical tumours, prostate cancer and bone malignancies including osteosarcoma. Mature CCN3 protein has five distinct modules and truncated protein variants with altered function are found in many cancers. Regulation by CCN3 is therefore cell type and isoform specific. CCN3 has emerged as a key player in stem cell regulation, hematopoiesis and a crucial component within the bone marrow microenvironment. (c) 2008 Elsevier Ltd. All rights reserved.