637 research outputs found
Repellent effect of volatile fatty acids on lesser mealworm (Alphitobius diaperinus)
Volatile fatty acids (VFAs) are a group of common metabolites and semiochemicals mediating information transfer between higher organisms and bacteria, either from microbiome or external environment. VFAs commonly occur among various insect orders. There are numerous studies exploring their influence on the behavior of different insect species. In relation to the papers published by J. E. McFarlane in 1985, we assessed the effects of formic, acetic, propionic, butyric and valeric acids on the spatial preference of the lesser mealworm (Alphitobius diaperinus), a common pest of stored food grain products and the poultry industry. The main aim of the presented study was to provide new angles in VFA research, recreating the classical study both with new methods and on economically significant pest species. This paper presents a novel method of continuous, simultaneous assessment of site preference and the travelled distance in a constant-flow olfactometer. All the tested VFAs, except valeric acid, had a significant repellent effect, with formic acid being effective even at the lowest used concentration. Additionally, the VFAs significantly altered the distance travelled by the insects. The obtained results indicate a potential role for VFAs in the olfactory guided behavior of A. diaperinus. It is suspected that the reaction to the presence of VFAs may deviate from the specificity of species’ original habitat
Cloud Detection in Multispectral Satellite Images Using Support Vector Machines With Quantum Kernels
Support vector machines (SVMs) are a well-established classifier effectively
deployed in an array of pattern recognition and classification tasks. In this
work, we consider extending classic SVMs with quantum kernels and applying them
to satellite data analysis. The design and implementation of SVMs with quantum
kernels (hybrid SVMs) is presented. It consists of the Quantum Kernel
Estimation (QKE) procedure combined with a classic SVM training routine. The
pixel data are mapped to the Hilbert space using ZZ-feature maps acting on the
parameterized ansatz state. The parameters are optimized to maximize the kernel
target alignment. We approach the problem of cloud detection in satellite image
data, which is one of the pivotal steps in both on-the-ground and on-board
satellite image analysis processing chains. The experiments performed over the
benchmark Landsat-8 multispectral dataset revealed that the simulated hybrid
SVM successfully classifies satellite images with accuracy on par with classic
SVMs.Comment: Prepared for IGARSS 2023 Proceedings, 4 pages, 2 figure
Optimizing Kernel-Target Alignment for cloud detection in multispectral satellite images
The optimization of Kernel-Target Alignment (TA) has been recently proposed
as a way to reduce the number of hardware resources in quantum classifiers. It
allows to exchange highly expressive and costly circuits to moderate size, task
oriented ones. In this work we propose a simple toy model to study the
optimization landscape of the Kernel-Target Alignment. We find that for
underparameterized circuits the optimization landscape possess either many
local extrema or becomes flat with narrow global extremum. We find the
dependence of the width of the global extremum peak on the amount of data
introduced to the model. The experimental study was performed using
multispectral satellite data, and we targeted the cloud detection task, being
one of the most fundamental and important image analysis tasks in remote
sensing.Comment: Prepared for IGARSS 2023 Proceedings, 4 pages, 4 figure
Detecting Clouds in Multispectral Satellite Images Using Quantum-Kernel Support Vector Machines
Support vector machines (SVMs) are a well-established classifier effectively
deployed in an array of classification tasks. In this work, we consider
extending classical SVMs with quantum kernels and applying them to satellite
data analysis. The design and implementation of SVMs with quantum kernels
(hybrid SVMs) are presented. Here, the pixels are mapped to the Hilbert space
using a family of parameterized quantum feature maps (related to quantum
kernels). The parameters are optimized to maximize the kernel target alignment.
The quantum kernels have been selected such that they enabled analysis of
numerous relevant properties while being able to simulate them with classical
computers on a real-life large-scale dataset. Specifically, we approach the
problem of cloud detection in the multispectral satellite imagery, which is one
of the pivotal steps in both on-the-ground and on-board satellite image
analysis processing chains. The experiments performed over the benchmark
Landsat-8 multispectral dataset revealed that the simulated hybrid SVM
successfully classifies satellite images with accuracy comparable to the
classical SVM with the RBF kernel for large datasets. Interestingly, for large
datasets, the high accuracy was also observed for the simple quantum kernels,
lacking quantum entanglement.Comment: 12 pages, 10 figure
Safety and effectiveness of very-high-power, short-duration ablation in patients with atrial fibrillation: Preliminary results
Background: Pulmonary vein isolation (PVI) is at the forefront of rhythm control strategies in patients with atrial fibrillation (AF). A very-high-power, short-duration (vHPSD) catheter, QDot MicroTM (Biosense Webster) was designed to improve the effectiveness of AF ablation within a shorter procedure time. The aim of this study was to compare the effectiveness and safety of PVI ablation between this vHPSD ablation mode and conventional ablation-index-guided ablation (ThermoCool Smarttouch SF catheter).
Methods: This single-center, retrospective, observational study enrolled 108 patients with AF, referred for catheter ablation between December 16, 2019 and December 3, 2021. In 54 procedures (mean age: 58.0 ± 12.3; 66.67% male), a QDot MicroTM catheter was used (vHPSD-group), and 54 patients (mean age: 57.2 ± 11.8; 70.37% male) were treated with a ThermoCool SmarttouchTM SF catheter (AI-group). The primary endpoint was freedom from AF 3 months after ablation.
Results: Atrial fibrillation was found to recur in 14.81% of patients in the vHPSD-group and in 31.48% of patients in the AI-group (p = 0.07). There was no difference in treatment-emergent adverse events between the two groups (6.3% vs. 0%; p = 0.10). One severe adverse event (a cerebral vascular accident) was observed in the vHPSD-group. The mean dose of remifentanil was reported to be lower during QDot MicroTM catheter-based PVI (p < 0.01). The vHPSD-based PVI was associated with shorter radiofrequency application time (p < 0.001), fluoroscopy time (p < 0.0001), and total procedure time (p < 0.0001).
Conclusions: This study suggests vHPSD ablation is safe, can reduce the dosage of analgesics during significantly shorter procedures and may enhance the success rate of catheter-based PVI
Echocardiographic assessment of tricuspid regurgitation and pericardial effusion after cardiac device implantation
Background: The frequency of cardiac implantable electronic device (CIED) implantations is constantly increasing. Pericardial effusion (PE) and tricuspid regurgitation (TR) may occur after CIED implantation. The aim of the present study is to evaluate the prevalence and risk factors for new occurrences or progression of TR and PE early after CIED implantation.
Methods: This is an on-going, single-center, observational study of patients after their first CIED implantation, with an echocardiographic evaluation within 60 days before and 7 days after the procedure. Data are presented for first 110 consecutive patients who underwent CIED implantation from August 2015 to July 2016.
Results: Median age was 75 years, and 44% were women. In total, 87 (79%) pacemakers, 21 (19%) implantable cardioverter-defibrillators and 2 cardiac resynchronization therapy devices were implanted. After CIED implantation, there was TR progression in 17 (16%) patients: 5 patients developed moderate TR, none developed severe TR. An increase in TR was more often observed after implantations performed by operators in training than by certified operators (35% vs. 12%, p = 0.02). New PE after the procedure was observed in 8 (7%) patients and was trivial ( < 5 mm) in all cases. Patients with new PE after implantation had lower baseline hemoglobin levels and tended to be women.
Conclusions: New PE and an increase in TR severity are rare complications early after CIED implantation. Operator experience might be related to TR progression. Increasing the number of patients in the current on-going study will allow a more reliable assessment of the prevalence and risk factors of these complications
Comparative effectiveness of torasemide versus furosemide in symptomatic therapy in heart failure patients: Preliminary results from the randomized TORNADO trial
Background: Recent reports suggest that torasemide might be more beneficial than furosemide inpatients with symptomatic heart failure (HF). The aim was to compare the effects of torasemide andfurosemide on clinical outcomes in HF patients.Methods: This study pilot consisted of data from the ongoing multicenter, randomized, unblindedendpoint phase IV TORNADO (NCT01942109) study. HF patients in New York Heart Association(NYHA) II–IV class with a stable dose of furosemide were randomized to treatment with equipotentialdose of torasemide (4:1) or continuation of unchanged dose of furosemide. On enrollment andcontrol visit (3 months after enrollment) clinical examination, 6-minute walk test (6MWT) andassessment of fluid retention by ZOE Fluid Status Monitor were performed. The primary endpoint wasa composite of improvement of NYHA class, improvement of at least 50 m during 6MWT and decreasein fluid retention of at least 0.5 W after 3-months follow-up.Results: The study group included 40 patients (median age 66 years; 77.5% male). During follow-up7 patients were hospitalized for HF worsening (3 in torasemide and 4 in furosemide-treated patients).The primary endpoint reached 15 (94%) and 14 (58%) patients on torasemide and furosemide, respectively(p = 0.03).Conclusions: In HF patients treated with torasemide fluid overload and symptoms improved more thanin the furosemide group. This positive effect occurred already within 3-month observation
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