182 research outputs found
Caridina acutirostris Schenkel 1902
No full textCaridina acutirostris Schenkel, 1902 Caridina acutirostris Schenkel, 1902: 496, Pl. 8: Figs. 3a–c, 4b [type locality: south of Danau Poso, Sulawesi (Celebes), Indonesia]; Bouvier, 1925: 166, Figs. 353–355; Chace, 1997: 6. Material examined. – Holotype: female, cl 5.2 mm, NHMB 3 a, south of Lake Poso, central Sulawesi, Indonesia, coll. Sarasin, no date indicated. Diagnosis. – Rostrum not reaching end of antennular peduncle, slightly upturned anteriorly, armed dorsally with 10 teeth in posterior 1/2, including 3 on carapace posterior to orbital margin, armed ventrally with 6 teeth. Antennal spine placed slightly below inferior orbital angle; pterygostomian margin rounded. Lateral pair of posterior telson spines longer than intermedian pairs. Stylocerite reaching near end of basal segment of antennular peduncle. Carpus of first pereiopod slightly excavated. Epipods well developed on first 4 pereiopods (after Chace, 1997). Remarks. – No fresh material was available for the present study. Chace (1997) has provided a diagnosis based on the original description. Although the first author has examined the single type specimen, the poor condition of the specimen prevents us from re-describing the species in detail. With its complete, well developed epipods (well developed in first 4 vs. at most, developed only in first 2), C. acutirostris can easily be separated from other Cairidina species of Lake Poso, Sulawesi. Although several collection trips have been made to the Lake Poso, specimens of C. acutirostris have not been collected. As all these trips did not sample all the possible habitats along the lake as well as the rivers connected the lake thoroughly, it is too early for us to state any possible causes. Distribution. – Known only from Lake Poso in central Sulawesi, Indonesia.Published as part of Cai, Yixiong & Wowor, Daisy, 2007, Atyid Shrimps From Lake Poso, Central Sulawesi, Indonesia With Description Of A New Species (Crustacea: Decapoda: Caridea), pp. 311-320 in Raffles Bulletin of Zoology 55 (2) on pages 314-315, DOI: 10.5281/zenodo.533378
A pilot study to assess peak systolic velocity as possible marker of atherosclerotic burden using ultrasound
No full textIntroduction: Ischemic heart disease (IHD) has been associated with lower peak systolic velocity (PSV) on penile Doppler measurements [1]. This study establishes whether carotid ultrasound (US) PSV was associated with computational fluid dynamics (CFD) outputs, which in turn may contribute to IHD pathogenesis. Methods: A sample of 57 subjects (with IHD: 27, without IHD: 30) had US velocity profiles (left- common carotid artery) determined between 10e12 equispaced points. Bezier curve fitting was used to fit the profile through the measured velocity points for a normalised diameter. PSV was correlated against CFD results such as wall shear stress (WSS) [2]. Difference in PSV between individuals with/without IHD was studied via t-test. Linear regression was carried out to see if peak systolic velocity was associated with CFD outputs. Any significant associations were analysed within stratified groups (with/without IHD). Results: PSV was significantly lower (p Z 0.042) in subjects with IHD (with IHD: 53.6 17.3 cm/s, without IHD: 62.8 16.1 cm/s). PSV was associated with carotid bulb average pressure drop (p < 0.001), area of average bulb WSS (<1 Pa: p Z 0.016, <2 Pa: p Z 0.006, <3 Pa: p Z 0.001). All the above associations remained significant in individuals with IHD (average bulb pressure drop: p Z 0.001, average bulb WSS (<1 Pa: p Z 0.013, <2 Pa: p Z 0.008, <3 Pa: p Z 0.003). In subjects without IHD, PSV was associated with only average bulb pressure drop (p Z 0.016). Conclusions: This study suggests that further work on PSV and its associations with CFD outputs is required in individuals with and without IHD in various vascular beds
Tree Awareness for Relational DBMS Kernels: Staircase Join
No full textRelational database management systems (RDBMSs) derive much of their eciency from the versatility of their core data structure: tables of tuples. Such tables are simple enough to allow for an ecient representation on all levels of the memory hierarchy, yet suciently generic to host a wide rang
Development of explicit and constitutive lattice-Boltzmann models for food product rheology
No full textEmulsions are found throughout various industries including oil extraction, biological
materials, and food products such as milk, condiments, and spreads. The study
of their rheology is therefore important due to its impact on manufacturing efficiency
and end product desirability. A key rheological measure is the emulsion viscosity,
the fluid’s resistance to flow, which affects the power required in production as well
as the taste and texture. An emulsion’s viscosity displays complex behaviour due
to the droplet interfaces and interactions. Similarly, the sheared self-diffusion coefficient
measures the amount of movement the droplets exhibit, due to the interactions
between droplets.
The presented mesoscopic lattice-Boltzmann models allow for these macroscopic
properties to emerge from the simulations due to the explicit modelling of the
droplets. A continuous surface force is applied to the lattice fluids to model droplet
interfaces. The model is implemented in such a way as to allow the simulation of
hundreds of droplets with limited computing power.
The model is initially applied to a pipe flow, with the development of a pressure
boundary condition. Boundary effects from the solid walls require their removal,
using Lees-Edwards boundary conditions to represent bulk flow in a sheared system.
The boundary conditions are extended to the multi-component flow, which allowed
simulations to provide results for various emulsion systems with varying droplet
concentrations, surface tensions, viscosity ratios, and shear rates. Trends and results
from experimental and theoretical literature are recovered and constitutive models
of emulsion viscosity have been evaluated. The agreement of these two dimensional
lattice-Boltzmann models with three dimensional experimental results shows the
usefulness of the method. The structure of the droplets and clustering behaviour
they exhibit are examined and compared to solid particle suspension literature.
Finally, the model is used in exploratory simulations to examine the effect of droplet
bidispersity on the macroscopic properties; the witnessed effect agrees well with solid
suspension literature.
This mesoscopic model will allow for phenomenon on this scale to be more easily
studied and may provide more accurate information for multi-scale analysis
Uncertainty quantification and personalisation of lumped parameter models of the cardiovascular system
No full textPersonalised medicine, facilitated by the growing capacity to collect comprehensive patient
data, aims to provide personalised therapies for each individual. Computational models
are boosting the capacity to draw diagnosis and prognosis, and future treatments will be
tailored not only to current health status and data, but also to an accurate projection of
the pathways to restore health by model predictions. These models, which are based on
physiology and physics rather than on population statistics, enable computational simulations
to reveal diagnostic information that would have otherwise remained concealed and to predict
treatment outcomes for individual patients. The inherent need for patient-specific models in
cardiology is clear and is driving the rapid development of tools and techniques for creating
personalised methods to guide pharmaceutical therapy, deployment of devices and surgical
interventions.
For computational models to have clinical utility, we must be able to provide a quantification
of the risk associated with any predictions or interpretations which are made from the model.
Lumped parameter models (LPM) represent the cardiovascular system as a series of electrical
segments, each characterised by parameter values that offer insights into the associated health
status. Given one can constrain the model with patient specific data such that the parameter
values are updated, one obtains a digital representation of a patient’s cardiovascular system.
This research investigates the crucial offline stage of uncertainty quantification for models,
primarily employing sensitivity analysis, with the goal of achieving personalisation. As
such, this work first examines the process of performing a global sensitivity analysis of a
cardiovascular LPM, establishing some best practices to ensure accurate model interpretations.
Then we assess the impact of the chosen outputs of a model when looking to quantify
uncertainty. We demonstrate how variation in the chosen outputs can significantly impact
one’s interpretation of a model. Following the enhanced understanding of the best practices
around sensitivity analysis, we extend a method for obtaining a personalised subset of input
parameters, acknowledging the inherent variability among individuals in medicine. Alongside
this, a novel examination of the sensitivity indices is proposed within the context of
personalised medicine to provide insight associated with the calibration of model parameters.
Finally, we investigate a data assimilation technique and explore the method’s effectiveness
for model personalisation. The primary outcome of this research is the development of an
offline model personalisation workflow, designed to reduce the uncertainty associated with
calibrating models to patient data to the greatest extent possible
Circulatory System Models
No full text<p>Release Notes:</p>
<h2>Breaking changes from v0.1.X:</h2>
<ol>
<li>The Double-Hill chamber <code>DHChamber</code> is now in terms of <code>dV/dt</code> rather than <code>dp/dt</code> which increases computation speed by an order of magnitude. The old form can be recovered using the <code>inP</code> argument. The parameter <code>Ev</code> has been removed. Please use the ventricular volume as an initial condition instead of the pressure. This can be calculated as </li>
<li>Compliance and Elastance are now in terms of dV/dt. Use the new argument <code>inP=true</code> to recover the old form. Initial conditions need to be changed accordingly.</li>
<li>Compliance and Elastance have options for external pressure as parameter <code>has_ep</code> and as a connector pin to connect other pressures to <code>has_variable_ep</code> - the latter can take an equation like <code>C.ep.p ~ LV.p * K</code>.</li>
<li>Chamber has been deleted and replaced with <code>VariableCompliance</code> which can take a function for <code>E(t)</code> and has external pressure options like the other compliances and elastances.</li>
</ol>
Circulatory System Models
No full textCirculatorySystemModels v0.1.2
<p><a href="https://github.com/TS-CUBED/CirculatorySystemModels.jl/compare/v0.1.1...v0.1.2">Diff since v0.1.1</a></p>
<p><strong>Merged pull requests:</strong></p>
<ul>
<li>Update docs (#21) (@sathvikbhagavan)</li>
</ul>
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