An unsupervised wavelet neural network model for approximating the solutions of non-linear nervous stomach model governed by tension, food and medicine

The human stomach is a complex organ. Its role is to degrade food particles by using mechanical forces and chemical reactions in order to release nutrients. All ingested items, including our nutrition, should first pass through the stomach, making it arguably the most crucial segment in the gastrointestinal tract. Computational and mathematical modeling of the stomach is an emerging field of biomechanics where several complex phenomena, such as solid mechanics of the gastric wall, gastric electrophysiology, and fluid mechanics of the digesta need to be addressed. Developing a meshfree comprehensive algorithm for solving the nervous stomach model that enables analysing the relationships between these phenomena remains one of the most significant challenges in biomechanics. This research dedicates to study the dynamics of nervous stomach model governed by a mathematical representation depending on three categories viz. Tension (T), Food (F) and Medicine (M), i.e. TFM model. In this regard, a machine learning paradigm, namely POLYnomial WinOwed with Gaussian (PolyWOG) Wavelet Neural Network (PWNN) model has been implemented for handling the non-linear TFM models. We compared the obtained outcomes of present work with results of a well-known numerical computing paradigm and an existing wavelet neural algorithm. Also, we have done statistical assessment studies at different testing points, which reveal that the proposed architecture is effective and accurate.

Sign function and ANN based pole placement for computing interval controls

This paper deals with estimation of interval controls for interval Linear Time Invariant (LTI) plants using pole placement technique. Generally, the parameters associated with LTI plant system are assumed to be crisp values, but due to the occurrence of error in experimentation, measurement or due to maintenance induced errors, the parameters are imprecise. As such, the LTI problem reduces to interval LTI. The pole placement problem is then reduced to interval algebraic equation viz. interval Diophantine equation using proper transfer function. Further, the interval Diophantine equation is transformed to Interval System of Linear Equations (ISLE) viz. interval Sylvester matrix equation. Initially, using interval arithmetic an interval algebraic approach has been applied to solve the ISLE for computing non-negative or non-positive controls. Then, another approach using Artificial Neural Network (ANN) is proposed for computing the interval controls. Further, algorithms based on sign function and ANN procedures have been discussed. Finally, the efficiency of the proposed algorithms has been verified using different order interval plants.

Planar Hall effect and anisotropic magnetoresistance in polar-polar interface of LaVO3-KTaO3 with strong spin-orbit coupling

Among the perovskite oxide family, KTaO₃ (KTO) has recently attracted considerable interest as a possible system for the realization of the Rashba effect. In this work, we report a novel conducting interface by placing KTO with another insulator, LaVO₃ (LVO) and report planar Hall effect (PHE) and anisotropic magnetoresistance (AMR) measurements. This interface exhibits a signature of strong spin-orbit coupling. Our experimental observations of two fold AMR and PHE at low magnetic fields (B) is similar to those obtained for topological systems and can be intuitively understood using a phenomenological theory for a Rashba spin-split system. Our experimental data show a B² dependence of AMR and PHE at low magnetic fields that could also be explained based on our model. At high fields (~8 T), we see a two fold to four fold transition in the AMR that could not be explained using only Rashba spin-split energy spectra.

Two dimensional electron gas (2DEG) at oxide interfaces is promising in modern electronic devices. Here, Wadehra et al. realize 2DEG at a novel interface composed of LaVO₃ and KTaO₃, where strong spin-orbit coupling and relativistic nature of the electrons in the 2DEG, leading to anisotropic magnetoresistance and planar Hall effect.

A novel Chebyshev neural network approach for solving singular arbitrary order Lane-Emden equation arising in astrophysics

The motivation of this investigation is to develop a single-layer Chebyshev Neural Network (ChNN) model to handle singular fractional (arbitrary)-order Lane-Emden type equations. These equations are well-known application problems of astrophysics and quantum mechanics. Fractional Lane-Emden equations are singular so it is very difficult to solve analytically. Thus, an efficient method is required to handle the above equations. Here, our main aim is to use a single-layer ChNN model for solving fractional Lane-Emden equations. ChNN model is one kind of Functional Link Neural Network (FLNN) in which the hidden layer is replaced by a functional expansion block of the input pattern using orthogonalshifted Chebyshev polynomials (SChP). Thus, the network parameters of ChNN are less than the Multi-Layer Artificial Neural Network (MLANN). We have considered factional-order singular nonlinear problems of astrophysics to show the computational effort of the proposed method. Back Propagation algorithm of the unsupervised version has been considered for minimizing the error function and updating the weights of the ChNN model. Computed results are displayed in terms of tables and graphs.

Development of a mathematical model to evaluate the rate of aggregate risk of invasive alien plant species: Fuzzy risk assessment approach

This study presents a novel approach to evaluate the rate of aggregate risk of Invasive Alien Plant Species. Using risk values and grade of importance of weights of risk factors which may reflect invasiveness of plant species are considered. We use Linguistic Ordered Weighted Averaging operator to evaluate the grade of important of weights. Since the risk values and important weights are identified from two different linguistic term sets, fuzzy set theory techniques were used to combine the two sets. The rates obtained from the model were compared with NRA risk levels and the model was validated with data from known and non-invasive species. The model is improved by weighting the risk values of risk factors. The improved model produced significant results and resulted a better tracking system for identifying potential invaders than the conventional risk assessment.

Stent Graft Exclusion of Pseudo-Aneurysm Arising from PTFE Hemodialysis Graft after Recurrence following Ultrasound Guided Thrombin Injection

There are various non-invasive or minimally invasive techniques for management of pseudoaneurysms including ultrasound guided compression, ultrasound guided thrombin injection and covered stent placement. We report a case where a covered stent graft was successfully used for the treatment of a pseudoaneurysm directly arising from a PTFE graft which recurred 3 months following treatment with ultrasound guided thrombin injection.

Modelling uncertainties in the diffusion-advection equation for radon transport in soil using interval arithmetic

Modelling radon transport in the earth crust is a useful tool to investigate the changes in the geo-physical processes prior to earthquake event. Radon transport is modeled generally through the deterministic advection-diffusion equation. However, in order to determine the magnitudes of parameters governing these processes from experimental measurements, it is necessary to investigate the role of uncertainties in these parameters. Present paper investigates this aspect by combining the concept of interval uncertainties in transport parameters such as soil diffusivity, advection velocity etc, occurring in the radon transport equation as applied to soil matrix. The predictions made with interval arithmetic have been compared and discussed with the results of classical deterministic model. The practical applicability of the model is demonstrated through a case study involving radon flux measurements at the soil surface with an accumulator deployed in steady-state mode. It is possible to detect the presence of very low levels of advection processes by applying uncertainty bounds on the variations in the observed concentration data in the accumulator. The results are further discussed.

Hermite Functional Link Neural Network for Solving the Van der Pol-Duffing Oscillator Equation

Hermite polynomial-based functional link artificial neural network (FLANN) is proposed here to solve the Van der Pol-Duffing oscillator equation. A single-layer hermite neural network (HeNN) model is used, where a hidden layer is replaced by expansion block of input pattern using Hermite orthogonal polynomials. A feedforward neural network model with the unsupervised error backpropagation principle is used for modifying the network parameters and minimizing the computed error function. The Van der Pol-Duffing and Duffing oscillator equations may not be solved exactly. Here, approximate solutions of these types of equations have been obtained by applying the HeNN model for the first time. Three mathematical example problems and two real-life application problems of Van der Pol-Duffing oscillator equation, extracting the features of early mechanical failure signal and weak signal detection problems, are solved using the proposed HeNN method. HeNN approximate solutions have been compared with results obtained by the well known Runge-Kutta method. Computed results are depicted in term of graphs. After training the HeNN model, we may use it as a black box to get numerical results at any arbitrary point in the domain. Thus, the proposed HeNN method is efficient. The results reveal that this method is reliable and can be applied to other nonlinear problems too.

Photoinduced Demagnetization and Insulator-to-Metal Transition in Ferromagnetic Insulating BaFeO_{3} Thin Films

We studied the electronic and magnetic dynamics of ferromagnetic insulating BaFeO_{3} thin films by using pump-probe time-resolved resonant x-ray reflectivity at the Fe 2p edge. By changing the excitation density, we found two distinctly different types of demagnetization with a clear threshold behavior. We assigned the demagnetization change from slow (∼150  ps) to fast (<70  ps) to a transition into a metallic state induced by laser excitation. These results provide a novel approach for locally tuning magnetic dynamics. In analogy to heat-assisted magnetic recording, metallization can locally tune the susceptibility for magnetic manipulation, allowing one to spatially encode magnetic information.

Damage control radiology in the severely injured patient: what the anaesthetist needs to know

In the treatment of severely injured patients, the term 'damage control radiology' has been used to parallel the modern concept of damage control surgery and the allied development of continuous damage control resuscitation from patient retrieval, through all transfers, to appropriate primary treatment. The aims of damage control radiology are (i) rapid identification of life-threatening injuries including bleeding sites, (ii) identification or exclusion of head or spinal injury, and (iii) prompt and accurate triage of patients to the operating theatre for thoracic, abdominal, or both surgeries or the angiography suite for endovascular haemorrhage control. If we are to achieve these aims, patients must have immediate access to modern multidetector computed tomography (MDCT) which is without doubt the most potent weapon in the diagnostic armamentarium. The most severely injured patients are those who have the most to benefit from early diagnosis and life-saving therapies. The traditional teaching that these patients should go immediately to surgery is challenged by technological developments in MDCT and recent clinical evidence.

Mortality reporting in interventional radiology: experience of a pilot audit with the Scottish Audit of Surgical Mortality

AIM

To describe the initial pilot phase of the 2009 Scottish Audit of Surgical Mortality (SASM), which includes outcomes and difficulties that arose during any interventional radiology (IR) procedure performed on patients in this audit over an 18 month period.

MATERIALS AND METHODS

Approximately 40 consultant interventional radiologists from all units in Scotland elected to participate in the audit. Each response was then peer reviewed after anonymisation of the patient and institution. If a relevant ACON (area for consideration or area of concern) was generated, this was checked by one of the other reviewers before communication with the original reporting radiologist and colleagues. There was then a right of reply by the reporting unit before formal documentation was sent out.

RESULTS

Initial results were analysed after 18 months period, during which time 95 forms relating to deaths of surgical inpatients were sent to interventional radiologists identified as having been involved in an IR procedure at some time during the patient's admission. Seventy-one forms had been returned by July 2010, of which 46 had gone through the entire SASM process. From these, 10 ACONs were attributed. Anonymised case vignettes and reports from these were used as educational tools.

CONCLUSION

Involvement with SASM is a useful process. Significant safety issues and learning points were identified in the pilot. The majority of ACONs identified by the audit were in patients who had undergone percutaneous biliary interventions.

Sedation in a radiology department--do radiologists follow their own guidelines?

The Royal College of Radiologists (RCR) published guidelines in 2003 which aimed to standardise and improve the safety of sedation in the modern Radiology department. As sedation requirements increase, we decided to audit our own departments understandings and practice with respect to sedation. A repeat audit cycle was performed following a re-educational lecture, one year later. Three common sedation case scenarios were incorporated into a questionnaire which detailed questioning on requirements for fasting, monitoring and the order and use of sedation drugs alongside analgesics. These were compared to the 2003 RCR guidelines. The audit was recycled at one year. Despite the RCR guidelines, freely available on the RCR website, there was a persisting variation in practice which revealed a lack of awareness of the requirements for adequate fasting and the importance of giving the opiate before the benzodiazepine (sedative) agent in cases where a combination are chosen. The audit did show a trend towards using shorter acting benzodiazepines, which is in keeping with the guidelines. Monitoring of vital signs was generally, well carried out. General awareness of the RCR guidelines for safe sedation in the Radiology department was initially low and practice found to be variable. Re-education saw some improvements but also, some persisting habitual deviations from the guidelines, particularly with respect to the order in which the opiate and sedative benzodiazepine were given.

Stent graft exclusion of pseudo-aneurysm arising from PTFE hemodialysis graft after recurrence following ultrasound guided thrombin injection

There are various non-invasive or minimally invasive techniques for management of pseudoaneurysms including ultrasound guided compression, ultrasound guided thrombin injection and covered stent placement. We report a case where a covered stent graft was successfully used for the treatment of a pseudoaneurysm directly arising from a PTFE graft which recurred 3 months following treatment with ultrasound guided thrombin injection.

Molecular characterization of novel progranulin (GRN) mutations in frontotemporal dementia

Frontotemporal dementia (FTD) is a clinical term encompassing dementia characterized by the presence of two major phenotypes: 1) behavioral and personality disorder, and 2) language disorder, which includes primary progressive aphasia and semantic dementia. Recently, the gene for familial frontotemporal lobar degeneration (FTLD) with ubiquitin-positive, tau-negative inclusions (FTLD-U) linked to chromosome 17 was cloned. In the present study, 62 unrelated patients from the Washington University Alzheimer's Disease Research Center and the Midwest Consortium for FTD with clinically diagnosed FTD and/or neuropathologically characterized cases of FTLD-U with or without motor neuron disease (MND) were screened for mutations in the progranulin gene (GRN; also PGRN). We discovered two pathogenic mutations in four families: 1) a single-base substitution within the 3' splice acceptor site of intron 6/exon 7 (g.5913A>G [IVS6-2A>G]) causing skipping of exon 7 and premature termination of the coding sequence (PTC); and 2) a missense mutation in exon 1 (g.4068C>A) introducing a charged amino acid in the hydrophobic core of the signal peptide at residue 9 (p.A9D). Functional analysis in mutation carriers for the splice acceptor site mutation revealed a 50% decrease in GRN mRNA and protein levels, supporting haploinsufficiency. In contrast, there was no significant difference in the total GRN mRNA between cases and controls carrying the p.A9D mutation. Further, subcellular fractionation and confocal microscopy indicate that although the mutant protein is expressed, it is not secreted, and appears to be trapped within an intracellular compartment, possibly resulting in a functional haploinsufficiency.

Novel presenilin 1 variant (P117A) causing Alzheimer's disease in the fourth decade of life

Over 160 rare genetic variants in presenilin 1 (PSEN1) are known to cause Alzheimer's disease (AD). In this study we screened a family with early-onset AD for mutations in PSEN1 using direct DNA sequencing. We identified a novel PSEN1 genetic variant which results in the substitution of a Proline with an Alanine at codon 117 (P117A). The P117A variant was present in all demented individuals and fifty percent of at risk individuals. This variant occurs at a site where three other disease-causing variants have been previously observed. In vitro functional studies demonstrate that the P117A variant results in an altered Abeta42/total Abeta ratio consistent with an AD causing mutation. The P117A variant is a novel mutation in PSEN1, which causes early-onset AD in an autosomal dominant manner.

TDP-43 A315T mutation in familial motor neuron disease

To identify novel causes of familial neurodegenerative diseases, we extended our previous studies of TAR DNA-binding protein 43 (TDP-43) proteinopathies to investigate TDP-43 as a candidate gene in familial cases of motor neuron disease. Sequencing of the TDP-43 gene led to the identification of a novel missense mutation, Ala-315-Thr, which segregates with all affected members of an autosomal dominant motor neuron disease family. The mutation was not found in 1,505 healthy control subjects. The discovery of a missense mutation in TDP-43 in a family with dominantly inherited motor neuron disease provides evidence of a direct link between altered TDP-43 function and neurodegeneration.

Endovascular repair of a ruptured mycotic aneurysm of the common iliac artery

This report describes the case of a ruptured mycotic aneurysm of the left common iliac artery, successfully treated with endovascular stent-grafting. A 64-year-old woman underwent diagnostic coronary angiography complicated by an infected hematoma of the left groin. Seven days later, she developed methicillin-resistant Staphylococcus aureus septicemia and CT scan evidence of perivascular inflammation around the left common iliac artery. This was followed by rupture of a mycotic aneurysm of the left common iliac artery. The lesion was successfully treated with a stent-graft and prolonged antibiotic therapy, and the patient remains free of infection 10 months later. Accumulating evidence suggests that endovascular repair can be used safely for the repair of ruptured infected aneurysms.

Endovascular Treatment of Common Iliac Occlusion in the Presence of Persistent Sciatic Artery

Persistent sciatic artery is a rare congenital anomaly. It is associated with increased incidence of aneurysmal dilatation, thrombosis, distal embolization, and atherosclerotic change. We describe the case of a patient with persistent sciatic artery who presented with a critically ischemic left leg as a result of an occluded left common iliac artery, which was treated by angioplasty and stenting, and discuss the endovascular iliac recanalization in the presence of a persistent sciatic artery.

Extreme cerebrospinal fluid amyloid beta levels identify family with late-onset Alzheimer's disease presenilin 1 mutation

OBJECTIVE

Aggregation and deposition of amyloid beta (Abeta) in the brain is thought to be central to the pathogenesis of Alzheimer's disease (AD). Recent studies suggest that cerebrospinal fluid (CSF) Abeta levels are strongly correlated with AD status and progression, and may be a meaningful endophenotype for AD. Mutations in presenilin 1 (PSEN1) are known to cause AD and change Abeta levels. In this study, we have investigated DNA sequence variation in the presenilin (PSEN1) gene using CSF Abeta levels as an endophenotype for AD.

METHODS

We sequenced the exons and flanking intronic regions of PSEN1 in clinically characterized research subjects with extreme values of CSF Abeta levels.

RESULTS

This novel approach led directly to the identification of a disease-causing mutation in a family with late-onset AD.

INTERPRETATION

This finding suggests that CSF Abeta may be a useful endophenotype for genetic studies of AD. Our results also suggest that PSEN1 mutations can cause AD with a large range in age of onset, spanning both early- and late-onset AD.