selected variables
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With the advancement of science and technology, new complex optimization problems have emerged, and the achievement of optimal solutions has become increasingly important. Many of these problems have features and difficulties such as non-convex, nonlinear, discrete search space, and a non-differentiable objective function. Achieving the optimal solution to such problems has become a major challenge. To address this challenge and provide a solution to deal with the complexities and difficulties of optimization applications, a new stochastic-based optimization algorithm is proposed in this study. Optimization algorithms are a type of stochastic approach for addressing optimization issues that use random scanning of the search space to produce quasi-optimal answers. The Selecting Some Variables to Update-Based Algorithm (SSVUBA) is a new optimization algorithm developed in this study to handle optimization issues in various fields. The suggested algorithm's key principles are to make better use of the information provided by different members of the population and to adjust the number of variables used to update the algorithm population during the iterations of the algorithm. The theory of the proposed SSVUBA is described, and then its mathematical model is offered for use in solving optimization issues. Fifty-three objective functions, including unimodal, multimodal, and CEC 2017 test functions, are utilized to assess the ability and usefulness of the proposed SSVUBA in addressing optimization issues. SSVUBA's performance in optimizing real-world applications is evaluated on four engineering design issues. Furthermore, the performance of SSVUBA in optimization was compared to the performance of eight well-known algorithms to further evaluate its quality. The simulation results reveal that the proposed SSVUBA has a significant ability to handle various optimization issues and that it outperforms other competitor algorithms by giving appropriate quasi-optimal solutions that are closer to the global optima.
- Klíčová slova
- optimization, optimization problem, population updating, population-based algorithm, selected variables, stochastic methods,
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: The aim of this study was to investigate risk factors for placental abruption and to determine if anamnestic variables such as inherited thrombosis or recurrent fetal loss might be used as a predictor for placental abruption. METHODS: A retrospective case-control study at the University Hospital, Palacky University, Olomouc, Czech Republic. One hundred and eighty women with placental abruptio out of 20,175 deliveries (0.79 %) who were compared to 196 unselected pregnant women. A detailed anamnesis was taken. RESULTS: Compared to controls, women with placental abruptio had a 12-fold increased prevalence of prior recurrent fetal loss and a 6-fold increased prevalence of inherited thrombosis. CONCLUSIONS: We found that recurrent fetal loss, and inherited thrombosis may be significant risk factors for placental abruptio.
- MeSH
- dospělí MeSH
- komplikace těhotenství MeSH
- lidé MeSH
- předčasné odlučování placenty diagnóza etiologie MeSH
- rizikové faktory MeSH
- studie případů a kontrol MeSH
- těhotenství MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Grassland is one of the most represented, while at the same time, ecologically endangered, land cover categories in the European Union. In view of the global climate change, detecting its change is growing in importance from both an environmental and a socio-economic point of view. A well-recognised tool for Land Use and Land Cover (LULC) Change Detection (CD), including grassland changes, is Remote Sensing (RS). An important aspect affecting the accuracy of change detection is finding the optimal indicators of LULC changes (i.e., variables). Inappropriately selected variables can produce inaccurate results burdened with a number of uncertainties. The aim of our study is to find the most suitable variables for the detection of grassland to cropland change, based on a pair of high resolution images acquired by the Landsat 8 satellite and from the vector database Land Parcel Identification System (LPIS). In total, 59 variables were used to create models using Generalised Linear Models (GLM), the quality of which was verified through multi-temporal object-based change detection. Satisfactory accuracy for the detection of grassland to cropland change was achieved using all of the statistically identified models. However, a three-variable model can be recommended for practical use, namely by combining the Normalised Difference Vegetation Index (NDVI), Wetness and Fifth components of Tasselled Cap. Increasing number of variables did not significantly improve the accuracy of detection, but rather complicated the interpretation of the results and was less accurate than detection based on the original Landsat 8 images. The results obtained using these three variables are applicable in landscape management, agriculture, subsidy policy, or in updating existing LULC databases. Further research implementing these variables in combination with spatial data obtained by other RS techniques is needed.
- Klíčová slova
- Change detection (CD), Cropland, Grassland, Normalized Difference Vegetation Index (NDVI), Tasseled Cap (TC), Variables,
- Publikační typ
- časopisecké články MeSH
AIMS: Platelet function testing is often affected by the existence of different pre-analytical variables that can cause platelet activation. The aim of this study was to assess the effect of such variables that are present when samples are taken (different anticoagulants, incubation temperature, and storage conditions) to select those which enable to reach optimal range of measured plasma concentrations of the two stable thromboxane A₂ metabolites, that is, thromboxane B₂ (TxB₂) and 11-dehydrothromboxane B₂ (11-dTxB₂). MATERIALS AND METHODS: For the purpose of this study, whole blood samples obtained from 20 volunteers were screened for TxB₂ and 11-dTxB₂ concentrations using commercial EIA kits (Cayman Chemicals™; Neogen™) in relation to the effect of different anticoagulants, using different incubation temperatures and storage conditions. RESULTS: Trisodium citrate has been shown not to be affecting the TxB₂ and 11-dTxB₂ concentrations compared with the values measured in the serum. Incubation of the samples for 1 h at 37 °C and freezing at -20 °C or -80 °C give the most suitable concentration range of both thromboxanes in the used EIA measurement. CONCLUSION: This study describes the setup of such pre-analytical phase conditions that enable the screening of platelet function in terms of the plasma concentrations of TxB₂ and 11-dTxB₂ in selected EIA measurement.
- MeSH
- antikoagulancia farmakologie MeSH
- Aspirin terapeutické užití MeSH
- časové faktory MeSH
- citráty farmakologie MeSH
- imunoenzymatické techniky MeSH
- inhibitory agregace trombocytů farmakologie MeSH
- inhibitory cyklooxygenasy farmakologie MeSH
- lidé MeSH
- odběr biologického vzorku * MeSH
- teplota MeSH
- thromboxan A2 krev metabolismus MeSH
- thromboxan B2 analogy a deriváty krev metabolismus MeSH
- trombocyty účinky léků metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- srovnávací studie MeSH
- Názvy látek
- 11-dehydro-thromboxane B2 MeSH Prohlížeč
- antikoagulancia MeSH
- Aspirin MeSH
- citráty MeSH
- inhibitory agregace trombocytů MeSH
- inhibitory cyklooxygenasy MeSH
- thromboxan A2 MeSH
- thromboxan B2 MeSH
- trisodium citrate MeSH Prohlížeč
The state of a molecular system can be described in terms of collective variables. These low-dimensional descriptors of molecular structure can be used to monitor the state of the simulation, to calculate free energy profiles or to accelerate rare events by a bias potential or a bias force. Frequent calculation of some complex collective variables may slow down the simulation or analysis of trajectories. Moreover, many collective variables cannot be explicitly calculated for newly sampled structures. In order to address this problem, we developed a new package called anncolvar. This package makes it possible to build and train an artificial neural network model that approximates a collective variable. It can be used to generate an input for the open-source enhanced sampling simulation PLUMED package, so the collective variable can be monitored and biased by methods available in this program. The computational efficiency and the accuracy of anncolvar are demonstrated on selected molecular systems (cyclooctane derivative, Trp-cage miniprotein) and selected collective variables (Isomap, molecular surface area).
- Klíčová slova
- collective variables, free energy simulations, metadynamics, molecular dynamics simulation, neural networks,
- Publikační typ
- časopisecké články MeSH
The effects of synthetic fertilizer and nutrient leaching are causing serious problems impacting soil function and its fertility. Mitigation of nutrient leaching and use of chemical fertilizer is crucial as fertile land adds up sustainability to climate changes. Biochar produced from agricultural bio-waste and municipal solid waste has been used for crop production and when applied in combination with organic nutrients may support mitigation of nutrient loss and adverse effects of chemical fertilizers. Different types of biochar and their application for soil enhancement have been observed, pine needle and sewage sludge derived low-temperature biochar along with compost, organic fertilizer in the form of manure and microalgal biomass may interact with soil chemistry and plant growth to impact nutrient loss and compensate the hazardous effect of chemical fertilizer, but it has not been investigated yet. This present study elaborates application of sewage sludge and pine needle biochar produced at 400 °C in an application rate of 5 % w/w and 10 t h-1 in combination with compost, manure and microalgal biomasses of Closteriopsis acicularis (BM1) and Tetradesmus nygaardi (BM2) on the growth of Chickpea (Cicer arietinum) and Fenugreek (Trigonella foenum-graecum) crop assessed in a pot experiment over a two crop (Chickpea - Fenugreek) cycle in Pakistan. Results depict that the pine needle biochar with additives has increased plant height by 104.1 ± 2.76 cm and fresh biomass by 49.9 ± 1.02 g, buffered the soil pH to 6.5 for optimum growth of crops and enhance carbon retention by 36 %. This study highlights the valorization of sewage sludge and pine needle into biochar and the effect of biochar augmentation, its impact on soil nutrients and plant biomass enhancement. The greener approach also mitigates and helps in the sustainable management of solid wastes.
- Klíčová slova
- Biochar, Chemical and structural characterization, Crop rotation, Microalgae, Organic additives, Soil,
- MeSH
- dřevěné a živočišné uhlí MeSH
- hnůj MeSH
- odpadní vody * MeSH
- průmyslová hnojiva MeSH
- půda * MeSH
- tuhý odpad MeSH
- uhlík MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biochar MeSH Prohlížeč
- dřevěné a živočišné uhlí MeSH
- hnůj MeSH
- odpadní vody * MeSH
- průmyslová hnojiva MeSH
- půda * MeSH
- tuhý odpad MeSH
- uhlík MeSH
Size-reduced microparticles were successfully obtained by solvent evaporation method. Different parameters were applied in each sample and their influence on microparticles was evaluated. As a model drug the insoluble ibuprofen was selected for the encapsulation process with Eudragit® RS. The obtained microparticles were inspected by optical microscopy and scanning electron microscopy. The effect of aqueous phase volume (600, 400, 200 ml) and the concentration of polyvinyl alcohol (PVA; 1.0% and 0.1%) were studied. It was evaluated how those variations and also size can affect microparticle characteristics such as encapsulation efficiency, drug loading, burst effect and microparticle morphology. It was observed that the sample prepared with 600 ml aqueous phase and 1% concentration of polyvinyl alcohol gave the most favorable results.Key words: microparticles solvent evaporation sustained drug release Eudragit RS®.
BACKGROUND: Prosthetic gait increases demands on stability. Some variability measures can be used to investigate the stability of movement for prosthetic feet. OBJECTIVES: The purpose of this study was to determine the influence of the prosthetic foot on ground reaction force variability for transtibial amputee gait. STUDY DESIGN: Comparative analysis. METHODS: Eleven male unilateral transtibial amputees participated in this study. Each subject walked at self-selected speed with both conventional (SACH) and energy storing (Sureflex) feet. Time and ground reaction force variables and their coefficients of variation were calculated for each foot type and limb. RESULTS: Mediolateral force variables had high variability for all conditions. The Sureflex had a larger variability than the SACH foot for the braking peak (p < 0.05), which may have been caused by gait instability after the heel strike. There were significant differences between intact and prosthetic limbs in total loading (force impulses) with the SACH foot (p < 0.05). CONCLUSIONS: The prosthetic foot and alignment issues related to the foot influence GRF variability. During the braking phase the SACH foot is characterized by higher variability in mediolateral direction and Sureflex by higher variability in anterior-posterior direction. CLINICAL RELEVANCE: Differences in variability in ground reaction force variables can represent a person's stability. Observing variability can contribute to better understanding of critical events in gait cycle with the use of various prosthetic feet.
- MeSH
- amputovaní * MeSH
- biomechanika MeSH
- chůze (způsob) fyziologie MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- pata fyziologie MeSH
- pohyb fyziologie MeSH
- posturální rovnováha fyziologie MeSH
- protézy - design * MeSH
- tibie chirurgie MeSH
- umělé končetiny * MeSH
- zatížení muskuloskeletálního systému fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
OBJECTIVE: The purpose of the study was to investigate the prevalence of health risk behaviours among a random sample of Korean adolescents and the relationship of psychological variables with health risk behaviours. METHODS: 885 students ranged from 7th to 9th grade were randomly selected from 3 junior high schools in Dobong-gu district, Seoul. Four Korean-version measures were used to assess the health risk behaviour and psychological variables of adolescents. Frequency analysis, correlation analysis, and regression analysis were performed to accomplish the purpose of the study. RESULTS: Korean adolescents showed high prevalence of physical inactivity (n = 67%), smoking (n = 54%), drinking alcohol (n = 69%), eating problem (n = 49%), mental health problem (n = 57%), and viewing pornography (n = 47%). In addition, this study revealed that the three psychological variables (multidimensional health locus of control, self-efficacy, and self-esteem) were significantly correlated with health risk behaviours, and had significant effect to account for health risk behaviours (R2 = 0.42 for physical inactivity, 0.33 for viewing pomography, 0.31 for smoking, 0.28 for mental health problems, 0.26 for illegal drug use, 0.19 for drinking alcohol, and 0.15 for eating problem). CONCLUSION: The current study provides significant information on psychological variables related to adolescents' health risk behaviour. This study has the potential to influence the development of better health education and promotion programs for adolescents.
- MeSH
- chování mladistvých psychologie MeSH
- interní-externí kontrola MeSH
- lidé MeSH
- mladiství MeSH
- riskování * MeSH
- sebeuplatnění MeSH
- zdravé chování * MeSH
- zdravotnické přehledy MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Korejská republika MeSH
BACKGROUND: Selective IgA deficiency (IgAD) is the most common immunoglobulin deficiency with a variety of clinical manifestations. The frequency of IgAD differs depending on the ethnic origin and clinical symptoms of investigated persons. METHODS: The prevalence of IgAD (serum IgA level <0.05 g/l) was determined in 5,310 Czech blood donors, 10,326 patients who had undergone immunological investigation, and 246 first-degree relatives of IgAD and common variable immunodeficiency (CVID) patients. RESULTS: IgAD was detected in 13 (1/408; 0.24%) of the blood donors. The prevalence of IgAD was increased both in children (48/3,113; 1.5%) and adults (33/3,824; 0.9%) referred for frequent respiratory tract infections (in both cases p<0.001) compared to the healthy population. The frequency of IgAD was 12/189 (6%) in first-degree relatives of IgAD patients and 9/57 (16%) in relatives of CVID patients, with the highest frequency observed in children of CVID patients. CONCLUSIONS: The prevalence of IgAD in the Czech healthy population is comparable to that in other Caucasians. The frequency is increased in children with recurrent respiratory tract infections and especially in relatives of patients with immunoglobulin deficiencies.
- MeSH
- běloši MeSH
- běžná variabilní imunodeficience komplikace imunologie MeSH
- dárci krve MeSH
- deficience IgA krev komplikace epidemiologie MeSH
- dítě MeSH
- dospělí MeSH
- imunoglobulinové izotypy krev MeSH
- infekce dýchací soustavy komplikace imunologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- nukleární rodina MeSH
- předškolní dítě MeSH
- prevalence MeSH
- rodiče MeSH
- senioři MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Česká republika epidemiologie MeSH
- Názvy látek
- imunoglobulinové izotypy MeSH
