Detection of atrial fibrillation episodes in long-term heart rhythm signals using a support vector machine

Atrial fibrillation (AF) is a serious heart arrhythmia leading to a significant increase of the risk for occurrence of ischemic stroke. Clinically, the AF episode is recognized in an electrocardiogram. However, detection of asymptomatic AF, which requires a long-term monitoring, is more efficient when based on irregularity of beat-to-beat intervals estimated by the heart rate (HR) features. Automated classification of heartbeats into AF and non-AF by means of the Lagrangian Support Vector Machine has been proposed. The classifier input vector consisted of sixteen features, including four coefficients very sensitive to beat-to-beat heart changes, taken from the fetal heart rate analysis in perinatal medicine. Effectiveness of the proposed classifier has been verified on the MIT-BIH Atrial Fibrillation Database. Designing of the LSVM classifier using very large number of feature vectors requires extreme computational efforts. Therefore, an original approach has been proposed to determine a training set of the smallest possible size that still would guarantee a high quality of AF detection. It enables to obtain satisfactory results using only 1.39% of all heartbeats as the training data. Post-processing stage based on aggregation of classified heartbeats into AF episodes has been applied to provide more reliable information on patient risk. Results obtained during the testing phase showed the sensitivity of 98.94%, positive predictive value of 98.39%, and classification accuracy of 98.86%.Web of Science203art. no. 76

Safety and efficacy of recombinant human erythropoietin treatment of anaemia associated with multiple myeloma in haemodialysed patients

Recombinant human erythropoietin (rHuEpo) was used to treat the anaemia of four haemodialysed patients (3 males, 1 female) with advanced multiple myeloma; the type of serum M component was IgG kappa in all cases. During the 6-month period preceding rHuEpo therapy the patients received multiple blood transfusions (range 4-22 units of packed red cells per patient). After the first month of treatment haematocrit increased from 23±3 (SD) to 32±4% and during the last 3 months the maintenance dose of rHuEpo was 143±37 U/kg per week to achieve a mean haematocrit of 35±1%. After introduction of rHuEpo, blood transfusions were no longer required and the patients reported an improvement in wellbeing. No apparent worsening of multiple myeloma has been observed over the treatment period ranging from 5 to 34 months (cumulative duration of treatment 55 months). Anti-hypertensive therapy was started in one case and increased in two patients. We conclude that rHuEpo appears to be effective and safe in treating anaemia associated with multiple myeloma in patients requiring haemodialysi

Effect of altered loading conditions during haemodialysis on left ventricular filling pattern

Changes in the circulating volume associated with haemodialysis result in modification of left ventricular loading conditions. To determine the influence of haemodialysis on Doppler indices of left ventricular filling, 12 patients (mean age 40.8 ±2.7 (SEM) years) with renal insufficiency but without overt heart disease were studied by Doppler-echocardiography immediately before and after haemodialysis. Haemodialysis resulted in a decrease in body weight from 68.0±3.8 kg to 65.0 ±3.7 kg (P< 0.01). Heart rate and blood pressure did not change significantly during haemodialysis. Left ventricular diastolic dimension (M-mode) decreased from 53.5±1.1 mm to 49.5±1.9 mm (P < 0.05), whereas the shortening fraction did not change. Haemodialysis elicited marked changes in the early diastolic rapid filling wave (E wave) recorded by pulsed Doppler at the level of the mitral annulus. Peak velocity of the early rapid filling phase (peak E) decreased significantly from 95.3 ± 8.2 cm .s−1 to 63.0 ±5.7cm .s−1 (P< 0.001) and mid-diastolic deceleration of transmitral velocity decreased from 437.3 ±54.2 cm . s−2 to 239.7 ±54.4 cm . s−2 (P<0.01). The peak filling velocity during atrial contraction (peak A) did not change (79.7 ±6.3 cm .s−1 vs 74.1±4.7 cm.s−1;P=NS). The ratio peak E/peak A decreasedfrom 1.19±0.06 to 0.85 ± 0.04 (P < 0.01) during haemodialysis. The results provide further evidence for the pronounced preload-dependence of Doppler indices of left ventricular diastolic functio

Optimisation of bio-oil extraction process from Beauty Leaf (Calophyllum inophyllum) oil seed as a second generation biodiesel source

The Beauty Leaf tree (Calophyllum inophyllum) is a potential source of non-edible vegetable oil for producing future generation biodiesel because of its ability to grow in a wide range of climate conditions, easy cultivation, high fruit production rate, and the high oil content in the seed. This plant naturally occurs in the coastal areas of Queensland and the Northern Territory in Australia, and is also widespread in south-east Asia, India and Sri Lanka. Although Beauty Leaf is traditionally used as a source of timber and orientation plant, its potential as a source of second generation biodiesel is yet to be exploited. In this study, the extraction process from the Beauty Leaf oil seed has been optimised in terms of seed preparation, moisture content and oil extraction methods. The two methods that have been considered to extract oil from the seed kernel are mechanical oil extraction using an electric powered screw press, and chemical oil extraction using nhexane as an oil solvent. The study found that seed preparation has a significant impact on oil yields, especially in the screw press extraction method. Kernels prepared to 15% moisture content provided the highest oil yields for both extraction methods. Mechanical extraction using the screw press can produce oil from correctly prepared product at a low cost, however overall this method is ineffective with relatively low oil yields. Chemical extraction was found to be a very effective method for oil extraction for its consistence performance and high oil yield, but cost of production was relatively higher due to the high cost of solvent. However, a solvent recycle system can be implemented to reduce the production cost of Beauty Leaf biodiesel. The findings of this study are expected to serve as the basis from which industrial scale biodiesel production from Beauty Leaf can be made

Testing and Validation of High Density Resequencing Microarray for Broad Range Biothreat Agents Detection

Rapid and effective detection and identification of emerging microbiological threats and potential biowarfare agents is very challenging when using traditional culture-based methods. Contemporary molecular techniques, relying upon reverse transcription and/or polymerase chain reaction (RT-PCR/PCR) provide a rapid and effective alternative, however, such assays are generally designed and optimized to detect only a limited number of targets, and seldom are capable of differentiation among variants of detected targets. To meet these challenges, we have designed a broad-range resequencing pathogen microarray (RPM) for detection of tropical and emerging infectious agents (TEI) including biothreat agents: RPM-TEI v 1.0 (RPM-TEI). The scope of the RPM-TEI assay enables detection and differential identification of 84 types of pathogens and 13 toxin genes, including most of the class A, B and C select agents as defined by the Centers for Disease Control and Prevention (CDC, Atlanta, GA). Due to the high risks associated with handling these particular target pathogens, the sensitivity validation of the RPM-TEI has been performed using an innovative approach, in which synthetic DNA fragments are used as templates for testing the assay's limit of detection (LOD). Assay specificity and sensitivity was subsequently confirmed by testing with full-length genomic nucleic acids of selected agents. The LOD for a majority of the agents detected by RPM-TEI was determined to be at least 104 copies per test. Our results also show that the RPM-TEI assay not only detects and identifies agents, but is also able to differentiate near neighbors of the same agent types, such as closely related strains of filoviruses of the Ebola Zaire group, or the Machupo and Lassa arenaviruses. Furthermore, each RPM-TEI assay results in specimen-specific agent gene sequence information that can be used to assess pathogenicity, mutations, and virulence markers, results that are not generally available from multiplexed RT-PCR/PCR-based detection assays

The current landscape of nucleic acid tests for filovirus detection.

Nucleic acid testing (NAT) for pathogenic filoviruses plays a key role in surveillance and to control the spread of infection. As they share clinical features with other pathogens, the initial spread of these viruses can be misdiagnosed. Tests that can identify a pathogen in the initial stages of infection are essential to control outbreaks. Since the Ebola virus disease (EVD) outbreak in 2014-2016 several tests have been developed that are faster than previous tests and more suited for field use. Furthermore, the ability to test for a range of pathogens simultaneously has been expanded to improve clinical pathway management of febrile syndromes. This review provides an overview of these novel diagnostic tests

Reduced-Risk Management of Rhagoletis cerasi Flies (Host Race Prunus) in Combination with a Preliminary Phenological Model

Seasonal flight activity of Rhagoletis cerasi (L.) (Diptera: Tephritidae) adults was monitored using yellow sticky traps at sweet cherry orchards under different management regimes in Bursa, northwestern Turkey, during 1997–1998. In the reduced-risk backyard orchards, soil ploughing in the fall or spring to destroy the pupae was combined with a single application of an insecticide, while conventionally managed orchards received six to seven insecticide applications for controlling adults. Traps in commercial orchards caught significantly fewer adults than those in reduced-risk backyard orchards. Levels of cherry fruit fly fruit damage were very low (0.1%) in commercial orchards, whereas infestation rates averaged 2.2% in reduced-risk orchards. A preliminary phenology model was developed for optimal timing of insecticide applications based on air temperature summations since 1 February. In the reduced-risk backyard orchards, the first flies were captured between 25 May and 2 June, corresponding to an average degree-day (DD) accumulation of 582.50 ± 10.50 DD at an altitude of 150 m. However, first adult emergence at 1170 m was recorded between 6 and 14 June, averaging 667.50 ± 14.50 DD. Adult emergence exhibited bimodal peaks in a single flight at low altitude but there was a single peak at high altitude sites. Total adult flight period averaged 459 ± 29.50 and 649 ± 25.50 DD at low and high altitude sites, respectively. Our prediction model suggests that the optimum spray-window for a single insecticide application occurs between 577.70 and 639.40 DD at 150 m and between 780.90 and 848.60 DD at 1170 m