1,027 research outputs found
Scoring system to facilitate diagnosis of Gaucher disease
Background:
Gaucher disease (GD) manifests heterogeneously and other conditions are often misdiagnosed in its place, leading to diagnostic delays. The Gaucher Earlier Diagnosis Consensus (GEDâC) initiative proposed a pointâscoring system (PSS) based on the signs and covariables that are most indicative of GD to help clinicians identify which individuals to test for GD.
Aims:
To validate the PSS retrospectively in a test population including patients with GD and other conditions with overlapping manifestations.
Methods:
Four cohorts of adults with GD, liver disease (LD), haematological malignancy (HM) or immune thrombocytopenia were identified from hospital records. Clinical data were audited for GEDâC factors identified as potentially indicative of GD and aggregate scores calculated (sum of scores/number of factors) based on published PSS weightings. Threshold discriminatory PSS scores, sensitivity and specificity were determined by receiverâoperating characteristic (ROC) analysis.
Results:
Among 100 patients (GD, n =â25; nonâGD, n =â75), analyses based on 11 possible factors estimated group mean (standard deviation) PSS scores of: GD (n =â14), 1.08 (0.25); nonâGD (n =â38), 0.58 (0.31). Mean betweenâgroup difference (95% confidence interval (CI)) was (â0.49 (â0.68, â0.31)) and area under the ROC analysis curve (95% CI) was 0.88 (0.78, 0.97). A threshold PSS score of 0.82 identified all 14 patients with GD in the analysis set (100% sensitivity) and 27 of 38 patients in the nonâGD group (71% specificity). Patients with LD and HM were most likely to have manifestations overlapping GD.
Conclusions:
Preliminary validation of the GEDâC PSS discriminated effectively between patients with GD and those with overlapping signs
Universality in Systems with Power-Law Memory and Fractional Dynamics
There are a few different ways to extend regular nonlinear dynamical systems
by introducing power-law memory or considering fractional
differential/difference equations instead of integer ones. This extension
allows the introduction of families of nonlinear dynamical systems converging
to regular systems in the case of an integer power-law memory or an integer
order of derivatives/differences. The examples considered in this review
include the logistic family of maps (converging in the case of the first order
difference to the regular logistic map), the universal family of maps, and the
standard family of maps (the latter two converging, in the case of the second
difference, to the regular universal and standard maps). Correspondingly, the
phenomenon of transition to chaos through a period doubling cascade of
bifurcations in regular nonlinear systems, known as "universality", can be
extended to fractional maps, which are maps with power-/asymptotically
power-law memory. The new features of universality, including cascades of
bifurcations on single trajectories, which appear in fractional (with memory)
nonlinear dynamical systems are the main subject of this review.Comment: 23 pages 7 Figures, to appear Oct 28 201
Substrate stabilisation and small structures in coral restoration: State of knowledge, and considerations for management and implementation.
Coral reef ecosystems are under increasing pressure from local and regional stressors and a changing climate. Current management focuses on reducing stressors to allow for natural recovery, but in many areas where coral reefs are damaged, natural recovery can be restricted, delayed or interrupted because of unstable, unconsolidated coral fragments, or rubble. Rubble fields are a natural component of coral reefs, but repeated or high-magnitude disturbances can prevent natural cementation and consolidation processes, so that coral recruits fail to survive. A suite of interventions have been used to target this issue globally, such as using mesh to stabilise rubble, removing the rubble to reveal hard substrate and deploying rocks or other hard substrates over the rubble to facilitate recruit survival. Small, modular structures can be used at multiple scales, with or without attached coral fragments, to create structural complexity and settlement surfaces. However, these can introduce foreign materials to the reef, and a limited understanding of natural recovery processes exists for the potential of this type of active intervention to successfully restore local coral reef structure. This review synthesises available knowledge about the ecological role of coral rubble, natural coral recolonisation and recovery rates and the potential benefits and risks associated with active interventions in this rapidly evolving field. Fundamental knowledge gaps include baseline levels of rubble, the structural complexity of reef habitats in space and time, natural rubble consolidation processes and the risks associated with each intervention method. Any restoration intervention needs to be underpinned by risk assessment, and the decision to repair rubble fields must arise from an understanding of when and where unconsolidated substrate and lack of structure impair natural reef recovery and ecological function. Monitoring is necessary to ascertain the success or failure of the intervention and impacts of potential risks, but there is a strong need to specify desired outcomes, the spatial and temporal context and indicators to be measured. With a focus on the Great Barrier Reef, we synthesise the techniques, successes and failures associated with rubble stabilisation and the use of small structures, review monitoring methods and indicators, and provide recommendations to ensure that we learn from past projects
The impact of low erythrocyte density in human blood on the fitness and energetic reserves of the African malaria vector Anopheles gambiae
Background
Anaemia is a common health problem in the developing world. This condition is characterized by a reduction in erythrocyte density, primarily from malnutrition and/or
infectious diseases such as malaria. As red blood cells are the primary source of protein for haematophagous mosquitoes, any reduction could impede the ability of mosquito vectors to transmit malaria by influencing their fitness or that of the parasites they transmit. The aim of this study was to determine the impact of differences in the density of red blood cells in human blood on malaria vector (Anopheles gambiae sensu stricto) fitness. The hypotheses tested are that mosquito vector energetic reserves and fitness are negatively influenced by reductions in the red cell density of host human blood meals commensurate with those expected from severe anaemia.
Methods
Mosquitoes (An. gambiae s.s.) were offered blood meals of different packed cell volume(PCV) of human blood consistent with those arising from severe anaemia (15%) and normalPCV (50%). Associations between mosquito energetic reserves (lipid, glucose and glycogen)and fitness measures (reproduction and survival) and blood meal PCV were investigated.
Results
The amount of protein that malaria vectors acquired from blood feeding (indexed by
haematin excretion) was significantly reduced at low blood PCV. However, mosquitoes
feeding on blood of low PCV had the same oviposition rates as those feeding on blood of normal PCV, and showed an increase in egg production of around 15%. The long-term survival of An. gambiae s.s was reduced after feeding on low PCV blood, but PCV had no significant impact on the proportion of mosquitoes surviving through the minimal period required to develop and transmit malaria parasites (estimated as 14 days post-blood feeding). The impact of blood PCV on the energetic reserves of mosquitoes was relatively minor.
Conclusions
These results suggest that feeding on human hosts whose PCV has been depleted due to severe anaemia does not significantly reduce the fitness or transmission potential of malaria vectors, and indicates that mosquitoes may be able exploit resources for reproduction more
efficiently from blood of low rather than normal PCV
improving mockup based requirement specification with end user annotations
Agile approaches, one of the key methodologies used in today's software projects, often rely on user interface mockups for capturing the goals that the system must satisfy. Mockups, as any other requirement artifact, may suffer from ambiguity and contradiction issues when several points of view are surveyed/elicited by different analysts. This article introduces a novel approach that enhances mockups with friendly end-user annotations that helps formalizing the requirements and reducing or identifying conflicts. We present an evaluation of the approach in order to measure how the use of annotations improves requirements quality
A genome-wide SNP-association study confirms a sequence variant (g.66493737C>T) in the equine myostatin (MSTN) gene as the most powerful predictor of optimum racing distance for Thoroughbred racehorses
<p>Abstract</p> <p>Background</p> <p>Thoroughbred horses have been selected for traits contributing to speed and stamina for centuries. It is widely recognized that inherited variation in physical and physiological characteristics is responsible for variation in individual aptitude for race distance, and that muscle phenotypes in particular are important.</p> <p>Results</p> <p>A genome-wide SNP-association study for optimum racing distance was performed using the EquineSNP50 Bead Chip genotyping array in a cohort of <it>n </it>= 118 elite Thoroughbred racehorses divergent for race distance aptitude. In a cohort-based association test we evaluated genotypic variation at 40,977 SNPs between horses suited to short distance (†8 f) and middle-long distance (> 8 f) races. The most significant SNP was located on chromosome 18: BIEC2-417495 ~690 kb from the gene encoding myostatin (<it>MSTN</it>) [<it>P</it><sub>unadj. </sub>= 6.96 à 10<sup>-6</sup>]. Considering best race distance as a quantitative phenotype, a peak of association on chromosome 18 (chr18:65809482-67545806) comprising eight SNPs encompassing a 1.7 Mb region was observed. Again, similar to the cohort-based analysis, the most significant SNP was BIEC2-417495 (<it>P</it><sub>unadj. </sub>= 1.61 à 10<sup>-9</sup>; <it>P</it><sub>Bonf. </sub>= 6.58 à 10<sup>-5</sup>). In a candidate gene study we have previously reported a SNP (g.66493737C>T) in <it>MSTN </it>associated with best race distance in Thoroughbreds; however, its functional and genome-wide relevance were uncertain. Additional re-sequencing in the flanking regions of the <it>MSTN </it>gene revealed four novel 3' UTR SNPs and a 227 bp SINE insertion polymorphism in the 5' UTR promoter sequence. Linkage disequilibrium was highest between g.66493737C>T and BIEC2-417495 (<it>r</it><sup>2 </sup>= 0.86).</p> <p>Conclusions</p> <p>Comparative association tests consistently demonstrated the g.66493737C>T SNP as the superior variant in the prediction of distance aptitude in racehorses (g.66493737C>T, <it>P </it>= 1.02 à 10<sup>-10</sup>; BIEC2-417495, <it>P</it><sub>unadj. </sub>= 1.61 à 10<sup>-9</sup>). Functional investigations will be required to determine whether this polymorphism affects putative transcription-factor binding and gives rise to variation in gene and protein expression. Nonetheless, this study demonstrates that the g.66493737C>T SNP provides the most powerful genetic marker for prediction of race distance aptitude in Thoroughbreds.</p
Hepatic safety of tipranavir/ritonavir (TPV/r)-based antiretroviral therapy: effect of hepatitis virus co-infection and baseline liver fibrosis
A comparative sequence analysis reveals a common GBD/FH3-FH1-FH2-DAD architecture in formins from Dictyostelium, fungi and metazoa
BACKGROUND: Formins are multidomain proteins defined by a conserved FH2 (formin homology 2) domain with actin nucleation activity preceded by a proline-rich FH1 (formin homology 1) domain. Formins act as profilin-modulated processive actin nucleators conserved throughout a wide range of eukaryotes. RESULTS: We present a detailed sequence analysis of the 10 formins (ForA to J) identified in the genome of the social amoeba Dictyostelium discoideum. With the exception of ForI and ForC all other formins conform to the domain structure GBD/FH3-FH1-FH2-DAD, where DAD is the Diaphanous autoinhibition domain and GBD/FH3 is the Rho GTPase-binding domain/formin homology 3 domain that we propose to represent a single domain. ForC lacks a FH1 domain, ForI lacks recognizable GBD/FH3 and DAD domains and ForA, E and J have additional unique domains. To establish the relationship between formins of Dictyostelium and other organisms we constructed a phylogenetic tree based on the alignment of FH2 domains. Real-time PCR was used to study the expression pattern of formin genes. Expression of forC, D, I and J increased during transition to multi-cellular stages, while the rest of genes displayed less marked developmental variations. During sexual development, expression of forH and forI displayed a significant increase in fusion competent cells. CONCLUSION: Our analysis allows some preliminary insight into the functionality of Dictyostelium formins: all isoforms might display actin nucleation activity and, with the exception of ForI, might also be susceptible to autoinhibition and to regulation by Rho GTPases. The architecture GBD/FH3-FH1-FH2-DAD appears common to almost all Dictyostelium, fungal and metazoan formins, for which we propose the denomination of conventional formins, and implies a common regulatory mechanism
Measurement and Interpretation of Fermion-Pair Production at LEP energies above the Z Resonance
This paper presents DELPHI measurements and interpretations of
cross-sections, forward-backward asymmetries, and angular distributions, for
the e+e- -> ffbar process for centre-of-mass energies above the Z resonance,
from sqrt(s) ~ 130 - 207 GeV at the LEP collider. The measurements are
consistent with the predictions of the Standard Model and are used to study a
variety of models including the S-Matrix ansatz for e+e- -> ffbar scattering
and several models which include physics beyond the Standard Model: the
exchange of Z' bosons, contact interactions between fermions, the exchange of
gravitons in large extra dimensions and the exchange of sneutrino in R-parity
violating supersymmetry.Comment: 79 pages, 16 figures, Accepted by Eur. Phys. J.
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