Shifting : one-inclusion mistake bounds and sample compression

We present new expected risk bounds for binary and multiclass prediction, and resolve several recent conjectures on sample compressibility due to Kuzmin and Warmuth. By exploiting the combinatorial structure of concept class F, Haussler et al. achieved a VC(F)/n bound for the natural one-inclusion prediction strategy. The key step in their proof is a d=VC(F) bound on the graph density of a subgraph of the hypercube—one-inclusion graph. The first main result of this report is a density bound of n∙choose(n-1,≤d-1)/choose(n,≤d) < d, which positively resolves a conjecture of Kuzmin and Warmuth relating to their unlabeled Peeling compression scheme and also leads to an improved one-inclusion mistake bound. The proof uses a new form of VC-invariant shifting and a group-theoretic symmetrization. Our second main result is an algebraic topological property of maximum classes of VC-dimension d as being d-contractible simplicial complexes, extending the well-known characterization that d=1 maximum classes are trees. We negatively resolve a minimum degree conjecture of Kuzmin and Warmuth—the second part to a conjectured proof of correctness for Peeling—that every class has one-inclusion minimum degree at most its VC-dimension. Our final main result is a k-class analogue of the d/n mistake bound, replacing the VC-dimension by the Pollard pseudo-dimension and the one-inclusion strategy by its natural hypergraph generalization. This result improves on known PAC-based expected risk bounds by a factor of O(log n) and is shown to be optimal up to a O(log k) factor. The combinatorial technique of shifting takes a central role in understanding the one-inclusion (hyper)graph and is a running theme throughout

Disability and the labour market : an analysis of British males

This paper attempts, using data from the British Labour Force Survey 1996, to examine to what extent differences in labour market outcomes between able-bodied and disabled men may be attributed to differences in endowments of human capital and associated productivity differences. Both labour force participation and selectivity corrected human capital equations are estimated and decomposition techniques applied to them. Using the methodology of Baldwin and Johnson [Baldwin, M., Johnson, W.G., 1994. Labor market discrimination against men with disabilities. Journal of Human Resources, XXIX(1), Winter, 1–19], the employment effects of wage discrimination against the disabled are also estimated. Evidence of both substantial wage and participation rate differences between able-bodied and disabled men are found, which have implications for the operation of the 1995 Disability Discrimination Act.

Refraction in children : a comparison of two methods of accommodation control

Purpose: The prevalence of refractive errors in children has been extensively researched. Comparisons between studies can, however, be compromised because of differences between accommodation control methods and techniques used for measuring refractive error. The aim of this study was to compare spherical refractive error results obtained at baseline and using two different accommodation control methods – extended optical fogging and cycloplegia, for two measurement techniques – autorefraction and retinoscopy. Methods: Participants comprised twenty-five school children aged between 6 and 13 years (mean age: 9.52 ± 2.06 years). The refractive error of one eye was measured at baseline and again under two different accommodation control conditions: extended optical fogging (+2.00DS for 20 minutes) and cycloplegia (1% cyclopentolate). Autorefraction and retinoscopy were both used to measure most plus spherical power for each condition. Results: A significant interaction was demonstrated between measurement technique and accommodation control method (p = 0.036), with significant differences in spherical power evident between accommodation control methods for each of the measurement techniques (p < 0.005). For retinoscopy, refractive errors were significantly more positive for cycloplegia compared to optical fogging, which were in turn significantly more positive than baseline, while for autorefraction, there were significant differences between cycloplegia and extended optical fogging and between cycloplegia and baseline only. Conclusions: Determination of refractive error under cycloplegia elicits more plus than using extended optical fogging as a method to relax accommodation. These findings support the use of cycloplegic refraction compared with extended optical fogging as a means of controlling accommodation for population based refractive error studies in children.

Which estimating technique?

This paper presents a unified view of the relationship between (1) quantity and (2) price generating mechanisms in estimating individual prime construction costs/prices. A brief review of quantity generating techniques is provided with particular emphasis on experientially based assumptive approaches and this is compared with the level of pricing data available for the quantities generated in terms of reliability of the ensuing prime cost estimates. It is argued that there is a tradeoff between the reliability of quantity items and reliability of rates. Thus it is shown that the level of quantity generation is optimised by maximising the joint reliability function of the quantity items and their associated rates. Some thoughts on how this joint reliability function can be evaluated and quantified follow. The application of these ideas is described within the overall strategy of the estimator's decision - "Which estimating technique shall I use for a given level of contract information? - and a case is made for the computer generation of estimates by several methods, with an indication of the reliability of each estimate, the ultimate choice of estimate being left to the estimator concerned. Finally, the potential for the development of automatic estimating systems within this framework is examined.

Development status and future prospects for a vaccine against Chlamydia trachomatis infection

Chlamydia trachomatis continues to be the most commonly reported sexually transmitted bacterial infection in many countries with more than 100 million new cases estimated annually. These acute infections translate into significant downstream health care costs, particularly for women, where complications can include pelvic inflammatory disease and other disease sequelae such as tubal factor infertility. Despite years of research, the immunological mechanisms responsible for protective immunity versus immunopathology are still not well understood, although it is widely accepted that T cell driven IFN-g and Th17 responses are critical for clearing infection. While antibodies are able to neutralize infections in vitro, alone they are not protective, indicating that any successful vaccine will need to elicit both arms of the immune response. In recent years, there has been an expansion in the number and types of antigens that have been evaluated as vaccines, and combined with the new array of mucosal adjuvants, this aspect of chlamydial vaccinology is showing promise. Most recently, the opportunities to develop successful vaccines have been given a significant boost with the development of a genetic transformation system for Chlamydia, as well as the identification of the key role of the chlamydial plasmid in virulence. While still remaining a major challenge, the development of a successful C.trachomatis vaccine is starting to look more likely.

Migraine association and linkage studies of an endothelial nitric oxide synthase (NOS3) gene polymorphism

Migraine shows strong familial aggregation. However, the number of genes involved in the disorder is unknown and not identified. Nitric oxide is involved in the central processing of pain stimuli and plays an important role in the regulation of basal or stimulated vasodilation. Nitric oxide synthase, which controls the synthesis of nitric oxide, could possibly be a cause, or candidate gene, in migraine etiology. In this study, we detected a polymorphism for endothelial nitric oxide synthase by polymerase chain reaction and tested this for association and linkage to migraine. Results from the study did not show an association of the nitric oxide synthase microsatellite when tested in 91 affected and 85 unaffected individuals. Using the FASTLINK program for parametric linkage analysis, the polymorphism did not show significant linkage to migraine when tested in four migraine pedigrees composed of 116 individuals, 52 affected. Total LOD scores excluded linkage up to 8.5 cM between the nitric oxide synthase polymorphism and migraine. Results using the nonparametric affected pedigree member form of analysis also did not support a role for this gene in migraine etiology.

The duration of Chlamydia muridarum genital tract infection and associated chronic pathological changes are reduced in IL-17 knockout mice but protection is not increased further by immunization

IL-17 is believed to be important for protection against extracellular pathogens, where clearance is dependent on neutrophil recruitment and local activation of epithelial cell defences. However, the role of IL-17 in protection against intracellular pathogens such as Chlamydia is less clear. We have compared (i) the course of natural genital tract C. muridarum infection, (ii) the development of oviduct pathology and (iii) the development of vaccine-induced immunity against infection in wild type (WT) BALB/c and IL-17 knockout mice (IL-17-/-) to determine if IL-17-mediated immunity is implicated in the development of infection-induced pathology and/or protection. Both the magnitude and duration of genital infection was significantly reduced in IL-17-/- mice compared to BALB/c. Similarly, hydrosalpinx was also greatly reduced in IL-17-/- mice and this correlated with reduced neutrophil and macrophage infiltration of oviduct tissues. Matrix metalloproteinase (MMP) 9 and MMP2 were increased in WT oviducts compared to IL-17-/- animals at day 7 post-infection. In contrast, oviducts from IL-17-/- mice contained higher MMP9 and MMP2 at day 21. Infection also elicited higher levels of Chlamydia-neutralizing antibody in serum of IL-17-/- mice than WT mice. Following intranasal immunization with C. muridarum Major Outer Membrane Protein (MOMP) and cholera toxin plus CpG adjuvants, significantly higher levels of chlamydial MOMP-specific IgG and IgA were found in serum and vaginal washes of IL-17-/- mice. T cell proliferation and IFNγ production by splenocytes was greater in WT animals following in vitro re-stimulation, however vaccination was only effective at reducing infection in WT, not IL-17-/- mice. Intranasal or transcutaneous immunization protected WT but not IL-17-/- mice against hydrosalpinx development. Our data show that in the absence of IL-17, the severity of C. muridarum genital infection and associated oviduct pathology are significantly attenuated, however neither infection or pathology can be reduced further by vaccination protocols that effectively protect WT mice.

Aqueous phase synthesis of copper nanoparticles : a link between heavy metal resistance and nanoparticle synthesis ability in bacterial systems

We demonstrate aqueous phase biosynthesis of phase-pure metallic copper nanoparticles (CuNPs) using a silver resistant bacterium Morganella morganii. This is particularly important considering that there has been no report that demonstrates biosynthesis and stabilization of pure copper nanoparticles in the aqueous phase. Electrochemical analysis of bacterial cells exposed to Cu2+ ions provides new insights into the mechanistic aspect of Cu2+ ion reduction within the bacterial cell and indicates a strong link between the silver and copper resistance machinery of bacteria in the context of metal ion reduction. The outcomes of this study take us a step closer towards designing rational strategies for biosynthesis of different metal nanoparticles using microorganisms.

Chemotherapy induced reversible posterior leukoencephalopathy syndrome

The reversible posterior leukoencephalopathy syndrome (RPLES) is a condition characterised by reversible neurological and radiological findings that has been associated with use of immunosuppressive, chemotherapeutic and more recently novel targeted therapies. We describe the case of a 50-year-old woman with advanced non-small cell lung cancer who developed status epilepticus shortly after receiving cisplatin and gemcitabine chemotherapy. The clinical, radiological and EEG findings during and post event are presented and are in keeping with a diagnosis of RPLES. Early recognition of this rare syndrome, supportive management and withdrawal of the offending agent appear to result in a reversal of the manifestations described. © 2007 Elsevier Ireland Ltd. All rights reserved.

Nucleotide sequence of coat protein gene for GPV isolate of barley yellow dwarf virus and construction of expression plasmid for plant

GPV is a Chinese serotype isolate of barley yellow dwarf virus (BYDV) that has no reaction with antiserum of MAV, PAV, SGV, RPV and RMV The sequence of the coat protein (CP) of GPV isolate of BYDV was identified and its amino acid sequence was deduced. The coding region for the putative GPV CP is 603 bases nucleotides and encodes a Mr 22 218 (22 ku) protein. The same as MAV, PAV and RPV, GPV contained a second ORF within the coat protein coding region. This protein of 17 024 Mr (17 ku) is thought to correspond to the Virion protein genome linked (Vpg). Sequence comparisons of the CP coding region between the GPV isolate of BYDV and other isolates of BYDV have been done. The nucleotide and amino acid sequence homology of GPV has a greater identity to the sequence of RPV than those of PAV and MAV. The GPV CP sequence stored 83.7% of nucleotide similarity and 77.5% of deduced amino acid similarity, whereas that of the PAV and MAV shared 56.9%, 53.2% and 44.1%, 43.8% respectively. According to BYDV-GPV CP sequence, two primers were designed. The cDNA of CP was produced by RT-PCR. Full-length cDNA of CP was inserted into plasmid to construct expression plasmids named pPPI1, pPPI2 and pPPI5 based on different promoters. The recombinant plasmids were identified by using α-32P-dATP labelled CP probe, α-32P-ATP labelled GPV RNA probe and sequencing to confirm real GPV CP gene cDNA in plasmids.

The silent and apparent neurological injury in transcatheter aortic valve implantation study (SANITY) : concept, design and rationale

Background The incidence of clinically apparent stroke in transcatheter aortic valve implantation (TAVI) exceeds that of any other procedure performed by interventional cardiologists and, in the index admission, occurs more than twice as frequently with TAVI than with surgical aortic valve replacement (SAVR). However, this represents only a small component of the vast burden of neurological injury that occurs during TAVI, with recent evidence suggesting that many strokes are clinically silent or only subtly apparent. Additionally, insult may manifest as slight neurocognitive dysfunction rather than overt neurological deficits. Characterisation of the incidence and underlying aetiology of these neurological events may lead to identification of currently unrecognised neuroprotective strategies. Methods The Silent and Apparent Neurological Injury in TAVI (SANITY) Study is a prospective, multicentre, observational study comparing the incidence of neurological injury after TAVI versus SAVR. It introduces an intensive, standardised, formal neurologic and neurocognitive disease assessment for all aortic valve recipients, regardless of intervention (SAVR, TAVI), valve-type (bioprosthetic, Edwards SAPIEN-XT) or access route (sternotomy, transfemoral, transapical or transaortic). Comprehensive monitoring of neurological insult will also be recorded to more fully define and compare the neurological burden of the procedures and identify targets for harm minimisation strategies. Discussion The SANITY study undertakes the most rigorous assessment of neurological injury reported in the literature to date. It attempts to accurately characterise the insult and sustained injury associated with both TAVI and SAVR in an attempt to advance understanding of this complication and associations thus allowing for improved patient selection and procedural modification.

Stable expression of silencing-suppressor protein enhances the performance and longevity of an engineered metabolic pathway

Transgenic engineering of plants is important in both basic and applied research. However, the expression of a transgene can dwindle over time as the plant's small (s)RNA-guided silencing pathways shut it down. The silencing pathways have evolved as antiviral defence mechanisms, and viruses have co-evolved viral silencing-suppressor proteins (VSPs) to block them. Therefore, VSPs have been routinely used alongside desired transgene constructs to enhance their expression in transient assays. However, constitutive, stable expression of a VSP in a plant usually causes pronounced developmental abnormalities, as their actions interfere with endogenous microRNA-regulated processes, and has largely precluded the use of VSPs as an aid to stable transgene expression. In an attempt to avoid the deleterious effects but obtain the enhancing effect, a number of different VSPs were expressed exclusively in the seeds of Arabidopsis thaliana alongside a three-step transgenic pathway for the synthesis of arachidonic acid (AA), an ω-6 long chain polyunsaturated fatty acid. Results from independent transgenic events, maintained for four generations, showed that the VSP-AA-transformed plants were developmentally normal, apart from minor phenotypes at the cotyledon stage, and could produce 40% more AA than plants transformed with the AA transgene cassette alone. Intriguingly, a geminivirus VSP, V2, was constitutively expressed without causing developmental defects, as it acts on the siRNA amplification step that is not part of the miRNA pathway, and gave strong transgene enhancement. These results demonstrate that VSP expression can be used to protect and enhance stable transgene performance and has significant biotechnological application.

Antiguo Oriente: Cuadernos del Centro de Estudios de Historia del Antiguo Oriente, 2008, n° 6 (número completo)

Sumario -- The pottery of Edom: A Correction / Israel Finkelstein & Lily Singer-Avitz -- The Jezirah Burnished Ware / Stefano Valentini -- The Cordage from Berenike (1994-2000): The Statics / André J. Veldmeijer -- A Reevaluation of the Use of !bz and bhy in Elephantine / Alejandro F. Botta -- Four Ur III Administrative Tablets in the Possesion of Professor Francis Carroll, University of Manitoba / John Nielsen -- Una actualización de la Cronología Baja: arqueología, historia y Biblia / Israel Finkelstein -- The Alleged “Anchor Point” of 732 BC for the Destrction of Hazor V / Peter James -- The “Wicked Priest” in Egyptology and Amarna Studies: A Reconsideration / Samuel Jackson -- Violencia fenicia en el Mediterráneo Oriental / Jordi Vidal -- Reportes de Excavación -- The Leatherwork from Deir el-Bachit: Preliminary Report / André J. Veldmeijer -- Reseñas bibliográficas -- Política editorial e instrucciones para los colaboradores -- Direcciones para envío de artículos y reseñas bibliográficas -- Colaboraciones en numeros anteriores

The Rain Forests of Home: an Atlas of People and Place

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