1,070 research outputs found
Consistent off-shell vertex and nucleon self-energy
We present a consistent calculation of half-off-shell form factors in the
pion-nucleon vertex and the nucleon self-energy. Numerical results are
presented. Near the on-shell point the pion-nucleon vertex is dominated by the
pseudovector coupling, while at large nucleon invariant masses we find a
sizable pseudoscalar admixture.Comment: 23 pages, 7 figures, REVTeX, submitted to Phys. Rev. C, replaced with
corrected versio
Quasi-Elastic Scattering in the Inclusive (He, t) Reaction
The triton energy spectra of the charge-exchange C(He,t) reaction
at 2 GeV beam energy are analyzed in the quasi-elastic nucleon knock-out
region. Considering that this region is mainly populated by the charge-exchange
of a proton in He with a neutron in the target nucleus and the final proton
going in the continuum, the cross-sections are written in the distorted-wave
impulse approximation. The t-matrix for the elementary exchange process is
constructed in the DWBA, using one pion- plus rho-exchange potential for the
spin-isospin nucleon- nucleon potential. This t-matrix reproduces the
experimental data on the elementary pn np process. The calculated
cross-sections for the C(He,t) reaction at to triton
emission angle are compared with the corresponding experimental data, and are
found in reasonable overall accord.Comment: 19 pages, latex, 11 postscript figures available at
[email protected], submitted to Phy.Rev.
Children's Medicines in Tanzania: A National Survey of Administration Practices and Preferences.
The dearth of age-appropriate formulations of many medicines for children poses a major challenge to pediatric therapeutic practice, adherence, and health care delivery worldwide. We provide information on current administration practices of pediatric medicines and describe key stakeholder preferences for new formulation characteristics. We surveyed children aged 6-12 years, parents/caregivers over age 18 with children under age 12, and healthcare workers in 10 regions of Tanzania to determine current pediatric medicine prescription and administration practices as well as preferences for new formulations. Analyses were stratified by setting, pediatric age group, parent/caregiver education, and healthcare worker cadre. Complete data were available for 206 children, 202 parents/caregivers, and 202 healthcare workers. Swallowing oral solid dosage forms whole or crushing/dissolving them and mixing with water were the two most frequently reported methods of administration. Children frequently reported disliking medication taste, and many had vomited doses. Healthcare workers reported medicine availability most significantly influences prescribing practices. Most parents/caregivers and children prefer sweet-tasting medicine. Parents/caregivers and healthcare workers prefer oral liquid dosage forms for young children, and had similar thresholds for the maximum number of oral solid dosage forms children at different ages can take. There are many impediments to acceptable and accurate administration of medicines to children. Current practices are associated with poor tolerability and the potential for under- or over-dosing. Children, parents/caregivers, and healthcare workers in Tanzania have clear preferences for tastes and formulations, which should inform the development, manufacturing, and marketing of pediatric medications for resource-limited settings
High-quality permanent draft genome sequence of Rhizobium sullae strain WSM1592; a Hedysarum coronarium microsymbiont from Sassari, Italy
Rhizobium sullae strain WSM1592 is an aerobic, Gram-negative, non-spore-forming rod that was isolated from an effective nitrogen (N2) fixing root nodule formed on the short-lived perennial legume Hedysarum coronarium (also known as Sulla coronaria or Sulla). WSM1592 was isolated from a nodule recovered from H. coronarium roots located in Ottava, bordering Sassari, Sardinia in 1995. WSM1592 is highly effective at fixing nitrogen with H. coronarium, and is currently the commercial Sulla inoculant strain in Australia. Here we describe the features of R. sullae strain WSM1592, together with genome sequence information and its annotation. The 7,530,820 bp high-quality permanent draft genome is arranged into 118 scaffolds of 118 contigs containing 7.453 protein-coding genes and 73 RNA-only encoding genes. This rhizobial genome is sequenced as part of the DOE Joint Genome Institute 2010 Genomic Encyclopedia for Bacteria and Archaea-Root Nodule Bacteria (GEBA-RNB) project
A Finite Representation of the Narrowing Space
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-14125-1_4Narrowing basically extends rewriting by allowing free variables
in terms and by replacing matching with unification. As a consequence,
the search space of narrowing becomes usually infinite, as in
logic programming. In this paper, we introduce the use of some operators
that allow one to always produce a finite data structure that still represents
all the narrowing derivations. Furthermore, we extract from this
data structure a novel, compact equational representation of the (possibly
infinite) answers computed by narrowing for a given initial term.
Both the finite data structure and the equational representation of the
computed answers might be useful in a number of areas, like program
comprehension, static analysis, program transformation, etc.Nishida, N.; Vidal, G. (2013). A Finite Representation of the Narrowing Space. En Logic-Based Program Synthesis and Transformation. Springer. 54-71. doi:10.1007/978-3-319-14125-1_4S5471Albert, E., Vidal, G.: The Narrowing-Driven Approach to Functional Logic Program Specialization. New Generation Computing 20(1), 3–26 (2002)Alpuente, M., Falaschi, M., Vidal, G.: Partial Evaluation of Functional Logic Programs. ACM Transactions on Programming Languages and Systems 20(4), 768–844 (1998)Alpuente, M., Falaschi, M., Vidal, G.: Compositional Analysis for Equational Horn Programs. In: RodrÃguez-Artalejo, M., Levi, G. (eds.) ALP 1994. LNCS, vol. 850, pp. 77–94. Springer, Heidelberg (1994)Antoy, S., Ariola, Z.: Narrowing the Narrowing Space. In: Hartel, P.H., Kuchen, H. (eds.) PLILP 1997. LNCS, vol. 1292, pp. 1–15. Springer, Heidelberg (1997)Arts, T., Giesl, J.: Termination of term rewriting using dependency pairs. Theoretical Computer Science 236(1–2), 133–178 (2000)Arts, T., Zantema, H.: Termination of Logic Programs Using Semantic Unification. In: Proietti, M. (ed.) LOPSTR 1995. LNCS, vol. 1048, pp. 219–233. Springer, Heidelberg (1996)Baader, F., Nipkow, T.: Term Rewriting and All That. Cambridge University Press (1998)Bae, K., Escobar, S., Meseguer, J.: Abstract Logical Model Checking of Infinite-State Systems Using Narrowing. In: Proceedings of the 24th International Conference on Rewriting Techniques and Applications. LIPIcs, vol. 21, pp. 81–96. Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2013)De Schreye, D., Glück, R., Jørgensen, J., Leuschel, M., Martens, B., Sørensen, M.: Conjunctive partial deduction: foundations, control, algorihtms, and experiments. Journal of Logic Programming 41(2&3), 231–277 (1999)Escobar, S., Meadows, C., Meseguer, J.: A rewriting-based inference system for the NRL Protocol Analyzer and its meta-logical properties. Theoretical Computer Science 367(1–2), 162–202 (2006)Escobar, S., Meseguer, J.: Symbolic Model Checking of Infinite-State Systems Using Narrowing. In: Baader, F. (ed.) RTA 2007. LNCS, vol. 4533, pp. 153–168. Springer, Heidelberg (2007)Fribourg, L.: SLOG: A Logic Programming Language Interpreter Based on Clausal Superposition and Rewriting. In: Proceedings of the Symposium on Logic Programming, pp. 172–185. IEEE Press (1985)Gnaedig, I., Kirchner, H.: Proving weak properties of rewriting. Theoretical Computer Science 412(34), 4405–4438 (2011)Hanus, M.: The integration of functions into logic programming: From theory to practice. Journal of Logic Programming 19&20, 583–628 (1994)Hanus, M. (ed.): Curry: An integrated functional logic language (vers. 0.8.3) (2012). http://www.curry-language.orgHermenegildo, M., Rossi, F.: On the Correctness and Efficiency of Independent And-Parallelism in Logic Programs. In: Lusk, E., Overbeck, R. (eds.) Proceedings of the 1989 North American Conf. on Logic Programming, pp. 369–389. The MIT Press, Cambridge (1989)Hölldobler, S. (ed.): Foundations of Equational Logic Programming. LNCS, vol. 353. Springer, Heidelberg (1989)Meseguer, J., Thati, P.: Symbolic Reachability Analysis Using Narrowing and its Application to Verification of Cryptographic Protocols. Electronic Notes in Theoretical Computer Science 117, 153–182 (2005)Middeldorp, A., Okui, S.: A Deterministic Lazy Narrowing Calculus. Journal of Symbolic Computation 25(6), 733–757 (1998)Nishida, N., Sakai, M., Sakabe, T.: Generation of Inverse Computation Programs of Constructor Term Rewriting Systems. IEICE Transactions on Information and Systems J88–D–I(8), 1171–1183 (2005) (in Japanese)Nishida, N., Sakai, M., Sakabe, T.: Partial Inversion of Constructor Term Rewriting Systems. In: Giesl, J. (ed.) RTA 2005. LNCS, vol. 3467, pp. 264–278. Springer, Heidelberg (2005)Nishida, N., Vidal, G.: Program inversion for tail recursive functions. In: Schmidt-Schauß, M. (ed.) Proceedings of the 22nd International Conference on Rewriting Techniques and Applications. LIPIcs, vol. 10, pp. 283–298. Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2011)Nishida, N., Vidal, G.: Computing More Specific Versions of Conditional Rewriting Systems. In: Albert, E. (ed.) LOPSTR 2012. LNCS, vol. 7844, pp. 137–154. Springer, Heidelberg (2013)Nutt, W., Réty, P., Smolka, G.: Basic Narrowing Revisited. Journal of Symbolic Computation 7(3/4), 295–317 (1989)Ohlebusch, E.: Advanced Topics in Term Rewriting. Springer, London, UK (2002)Palamidessi, C.: Algebraic Properties of Idempotent Substitutions. In: Paterson, M. (ed.) ICALP 1990. LNCS, vol. 443, pp. 386–399. Springer, Heidelberg (1990)Ramos, J.G., Silva, J., Vidal, G.: Fast Narrowing-Driven Partial Evaluation for Inductively Sequential Systems. In: Danvy, O., Pierce, B.C. (eds.) Proceedings of the 10th ACM SIGPLAN International Conference on Functional Programming, pp. 228–239. ACM Press (2005)Slagle, J.R.: Automated theorem-proving for theories with simplifiers, commutativity and associativity. Journal of the ACM 21(4), 622–642 (1974
The University of Akron Human Powered Vehicle Team
The University of Akron Human Powered Vehicle Team’s 2016 vehicle, Klokan, was designed, manufactured and tested with safety, reliability, performance and ease of use in mind. The vehicle is a fully faired tadpole trike with a lightweight aluminum frame constructed from 6061-T6 tubing having a total weight of 8.9 lbs. To complement the lightweight frame, the fairing is constructed from polycarbonate, PETG and carbon fiber strips which combine into a lightweight, easy to manufacture weather barrier and aerodynamic structure. Klokan was designed to be a safe and efficient mode of everyday transportation which ensures that riders are sufficiently protected by a rollover protection system (RPS) which was designed to meet the ASME HPVC requirements with a minimum safety factor of two.
The project scope includes all aspects of design and fabrication to create a vehicle that is easy to manufacture, easy to use, safe, and low cost to facilitate its usability in everyday situations. The team completed research on how to improve the manufacturability, reliability, and performance through analysis of designs, computer based modeling, and physical testing to validate that the bike meets team goals as well as exceeding the requirements set by the ASME Human Powered Vehicle Competition.
The frame was designed in a manner that reduces welding through the use of bends and allows for precision fixturing to be manufactured and used to construct multiple frames quickly and efficiently. The fairing’s modular construction reduces the need for specialized tooling while minimizing weight and construction time. The team designed and successfully implemented an innovative rollover warning system which actively monitors the percentage of vehicle load on each tire and warns the driver through audible tone and visual warning light prior to a dangerous rollover becoming imminent
Global access to surgical care: a modelling study
Background More than 2 billion people are unable to receive surgical care based on operating theatre density alone.
The vision of the Lancet Commission on Global Surgery is universal access to safe, aff ordable surgical and anaesthesia
care when needed. We aimed to estimate the number of individuals worldwide without access to surgical services as
defi ned by the Commission’s vision.
Methods We modelled access to surgical services in 196 countries with respect to four dimensions: timeliness,
surgical capacity, safety, and aff ordability. We built a chance tree for each country to model the probability of surgical
access with respect to each dimension, and from this we constructed a statistical model to estimate the proportion of
the population in each country that does not have access to surgical services. We accounted for uncertainty with oneway
sensitivity analyses, multiple imputation for missing data, and probabilistic sensitivity analysis.
Findings At least 4·8 billion people (95% posterior credible interval 4·6–5·0 [67%, 64–70]) of the world’s population
do not have access to surgery. The proportion of the population without access varied widely when stratifi ed by
epidemiological region: greater than 95% of the population in south Asia and central, eastern, and western sub-
Saharan Africa do not have access to care, whereas less than 5% of the population in Australasia, high-income North
America, and western Europe lack access.
Interpretation Most of the world’s population does not have access to surgical care, and access is inequitably
distributed. The near absence of access in many low-income and middle-income countries represents a crisis, and as
the global health community continues to support the advancement of universal health coverage, increasing access to
surgical services will play a central role in ensuring health care for all
Disturbances across whole brain networks during reward anticipation in an abstinent addiction population.
The prevalent spatial distribution of abnormalities reported in cognitive fMRI studies in addiction suggests there are extensive disruptions across whole brain networks. Studies using resting state have reported disruptions in network connectivity in addiction, but these studies have not revealed characteristics of network functioning during critical psychological processes that are disrupted in addiction populations. Analytic methods that can capture key features of whole brain networks during psychological processes may be more sensitive in revealing additional and widespread neural disturbances in addiction, that are the provisions for relapse risk, and targets for medication development. The current study compared a substance addiction (ADD; n = 83) group in extended abstinence with a control (CON; n = 68) group on functional MRI (voxel-wise activation) and global network (connectivity) measures related to reward anticipation on a monetary incentive delay task. In the absence of group differences on MID performance, the ADD group showed reduced activation predominantly across temporal and visual regions, but not across the striatum. The ADD group also showed disruptions in global network connectivity (lower clustering coefficient and higher characteristic path length), and significantly less connectivity across a sub-network comprising frontal, temporal, limbic and striatal nodes. These results show that an addiction group in extended abstinence exhibit localised disruptions in brain activation, but more extensive disturbances in functional connectivity across whole brain networks. We propose that measures of global network functioning may be more sensitive in highlighting latent and more widespread neural disruptions during critical psychological processes in addiction and other psychiatric disorders
Mining expressed sequence tags identifies cancer markers of clinical interest
BACKGROUND: Gene expression data are a rich source of information about the transcriptional dis-regulation of genes in cancer. Genes that display differential regulation in cancer are a subtype of cancer biomarkers. RESULTS: We present an approach to mine expressed sequence tags to discover cancer biomarkers. A false discovery rate analysis suggests that the approach generates less than 22% false discoveries when applied to combined human and mouse whole genome screens. With this approach, we identify the 200 genes most consistently differentially expressed in cancer (called HM200) and proceed to characterize these genes. When used for prediction in a variety of cancer classification tasks (in 24 independent cancer microarray datasets, 59 classifications total), we show that HM200 and the shorter gene list HM100 are very competitive cancer biomarker sets. Indeed, when compared to 13 published cancer marker gene lists, HM200 achieves the best or second best classification performance in 79% of the classifications considered. CONCLUSION: These results indicate the existence of at least one general cancer marker set whose predictive value spans several tumor types and classification types. Our comparison with other marker gene lists shows that HM200 markers are mostly novel cancer markers. We also identify the previously published Pomeroy-400 list as another general cancer marker set. Strikingly, Pomeroy-400 has 27 genes in common with HM200. Our data suggest that a core set of genes are responsive to the deregulation of pathways involved in tumorigenesis in a variety of tumor types and that these genes could serve as transcriptional cancer markers in applications of clinical interest. Finally, our study suggests new strategies to select and evaluate cancer biomarkers in microarray studies
Selective regulation of IP3-receptor-mediated Ca2+ signaling and apoptosis by the BH4 domain of Bcl-2 versus Bcl-Xl
Antiapoptotic B-cell lymphoma 2 (Bcl-2) targets the inositol 1,4,5-trisphosphate receptor (IP3R) via its BH4 domain, thereby suppressing IP3R Ca2+-flux properties and protecting against Ca2+-dependent apoptosis. Here, we directly compared IP3R inhibition by BH4-Bcl-2 and BH4-Bcl-Xl. In contrast to BH4-Bcl-2, BH4-Bcl-Xl neither bound the modulatory domain of IP3R nor inhibited IP3-induced Ca2+ release (IICR) in permeabilized and intact cells. We identified a critical residue in BH4-Bcl-2 (Lys17) not conserved in BH4-Bcl-Xl (Asp11). Changing Lys17 into Asp in BH4-Bcl-2 completely abolished its IP3R-binding and -inhibitory properties, whereas changing Asp11 into Lys in BH4-Bcl-Xl induced IP3R binding and inhibition. This difference in IP3R regulation between BH4-Bcl-2 and BH4-Bcl-Xl controls their antiapoptotic action. Although both BH4-Bcl-2 and BH4-Bcl-Xl had antiapoptotic activity, BH4-Bcl-2 was more potent than BH4-Bcl-Xl. The effect of BH4-Bcl-2, but not of BH4-Bcl-Xl, depended on its binding to IP(3)Rs. In agreement with the IP3R-binding properties, the antiapoptotic activity of BH4-Bcl-2 and BH4-Bcl-Xl was modulated by the Lys/Asp substitutions. Changing Lys17 into Asp in full-length Bcl-2 significantly decreased its binding to the IP3R, its ability to inhibit IICR and its protection against apoptotic stimuli. A single amino-acid difference between BH4-Bcl-2 and BH4-Bcl-Xl therefore underlies differential regulation of IP(3)Rs and Ca2+-driven apoptosis by these functional domains. Mutating this residue affects the function of Bcl-2 in Ca2+ signaling and apoptosis
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