Possible Aspects of E-Materials Application in the Teaching Process

This study was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia, and these results are parts of the Grant No. 451-03-68/2022-14/200132 with University of Kragujevac - Faculty of Technical Sciences Čačak.The effectiveness of the teaching process and learning is partly determined by the quality of the teaching material. Digital teaching material means all material that can be used and distributed in electronic form. This paper presents aspects of the application of e-materials in the teaching process, which are based on technological progress and the development of new possibilities. The paper discusses the types of e-materials as well as their role in the teaching process.Publishe

Application of Genetic Algorithm and Linear Programming for determination of optimal production volume

The problem of determining the optimal production volume is one of the most important problems faced by the management of companies in modern industry. Determining the production volume primarily depends on the customer demands, i.e. demands from the market, but also from some other factors, such as production capacity, supplier capacity and flexibility, raw material costs, etc. In this paper, the way to determine the optimal production volume is defined by using one metaheuristic and one numerical method, namely Genetic Algorithm and Linear Programming, respectively. In addition, a comparative analysis of these methods was performed when it comes to the small-scale problem such as the problem discussed in this paper.Publishe

The Impact of Global Changes on the Transformation of Politics, Economy and Education

This study was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia, and these results are parts of the Grant No. 451-03-68/2022-14/200132 with University of Kragujevac - Faculty of Technical Sciences Čačak.Society faces many challenges in transitioning toward sustainable development, and education is key to make this transition happen. Through education we influence on human consciousness, create their needs and changing behavior. One of most important educational programs is environmental education. It brings motivations, skills, values and commitment that people need to efficiently manage their earth’s resources and take responsibility for maintaining environmental quality and understand the problems they face. The limitation of access to certain resources is getting closer and we need to be aware of those limitations and put those in center of our life and work. The most effective way for doing it is throught environmental education started from earliest age. The limitation of access to certain resources is getting closer, and this fundamentally changes our relationship to economics, politics and ecology. This paper discusses the imperative of action within the limits of the finite world. The paper emphasizes the pressure on natural resources, which means that politics and the economy will have to undergo a radical transformation in order to be suitable not only today, but also in the future.Publishe

Uticaj pentobarbitala i pentilenetetrazola na nivo azot oksida u frontalnom korteksu pacova

Levels of nitric oxide (NO) in the rats frontal cortex were continuously monitored before and after intraperitoneal administration of an antiepileptic drug-pentobarbital (20 and 40 mg/kg) or convulsant drug - pentylenetetrazol (50 mg/kg). Pentobarbital decreased the levels of NO in a dose dependent manner However, NO levels had a tendency to increase following the administration of pentylenetetrazol. It is suggested that central NO participates in the modulation of neuronal excitability, supporting the idea that NO is an important excitatory factor involved in the regulation of seizure susceptibility. Also, our results on anaesthetized rats suggests that endogenous NO may be involved in the mechanism of action of antiepileptic and analeptic drugs and this further suggest that NO levels in the human brain may decrease during antiepileptic therapy and increase during epileptic attacks or administration of excitatory drugs. The aim of the present study was to determine the possible role of NO levels in the brain during neuronal excitability and seizures.Nivo azot oksida (NO) u frontalnom korteksu pacova meren je kontinuirano kako pre, tako i nakon intraperitonealne primene antiepileptika pentobarbitala (u dozi od 20 i 40 mg/kg) ili konvulzivnog agensa pentilenetetrazola (u dozi od 50 mg/kg). Rezultati ovih eksperimenta su ukazali da pentobarbital smanjuje nivo NO u frontalnom korteksu pacova, dok koncentracija NO ima tendeciju rasta nakon primene pentilenetetrazola. Osim toga, dokazano je da endogeni NO ima važnu ekscitatornu ulogu u centralnim mehanizmima nastanka epilepsije. Takođe, naši rezultati su ukazali da kod anestetisanih životinja endogeni nivo NO ima uticaja na dejstvo kako antikonvulzivnih, tako i prokonvulzivnih lekova. Nivo NO u mozgu pacova je bio snižen tokom terapije antiepilepticima, a povišen tokom epileptičkih napada ili primene lekova iz grupe centralnih stimulansa

Technological Advancement in Tower-Based Canopy Reflectance Monitoring: The AMSPEC-III System

Understanding plant photosynthesis, or Gross Primary Production (GPP), is a crucial aspect of quantifying the terrestrial carbon cycle. Remote sensing approaches, in particular multi-angular spectroscopy, have proven successful for studying relationships between canopy-reflectance and plant-physiology processes, thus providing a mechanism to scale up. However, many different instrumentation designs exist and few cross-comparisons have been undertaken. This paper discusses the design evolution of the Automated Multiangular SPectro-radiometer for Estimation of Canopy reflectance (AMSPEC) series of instruments. Specifically, we assess the performance of the PP-Systems Unispec-DC and Ocean Optics JAZ-COMBO spectro-radiometers installed on an updated, tower-based AMSPEC-III system. We demonstrate the interoperability of these spectro-radiometers, and the results obtained suggest that JAZ-COMBO can successfully be used to substitute more expensive measurement units for detecting and investigating photosynthesis and canopy spectra. We demonstrate close correlations between JAZ-COMBO and Unispec-DC measured canopy radiance (0.75 ≤ R² ≤ 0.85) and solar irradiance (0.95 ≤ R² ≤ 0.96) over a three month time span. We also demonstrate close agreement between the bi-directional distribution functions obtained from each instrument. We conclude that cost effective alternatives may allow a network of AMSPEC-III systems to simultaneously monitor various vegetation types in different ecosystems. This will allow to scale and improve our understanding of the interactions between vegetation physiology and spectral characteristics, calibrate broad-scale observations to stand-level measurements, and ultimately lead to improved understanding of changing vegetation spectral features from satellite.Keywords: multi-angle spectroscopy, photosynthesis, PRI, gross primary production, spectro-radiometer, light use efficiency, remote sensingThis is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by MDPI. The published article can be found at: http://www.mdpi.com/journal/sensor

ANTHROPOMETRIC CHARACTERISTICS AND MOTOR ABILITIES IN 13-15 YEARS OLD FEMALE VOLLEYBALL PLAYERS

The goal of this research was to determine whether there is a difference in themanifestation of measured anthropometric characteristics and tested motor abilities offemale volleyball players that are 13-15 years old. The sample of participants consists of 62female volleyball players divided into three groups according to their age. The sample ofvariables has two sub-samples: 18 variables belonging to anthropometric space and 14variables belonging to the space of motor skills. A variance analysis has indicatedsignificant intragroup differences in all the analyzed variables, except the variable forassessment of flexibility in the shoulder angle region. The results of a post hoc test - theBoniferroni procedure - have determined that the level of differences between the groups, inrelation to the examined variables, ranges from those that have statistical significance ofp<0,05, for variables of anthropometric space (Body weight, arm span, Body mass index,the Single arm reach test, Both arm reach test, Upper arm and forearm volume) and thesame value for the motor skills space (Hip joint flexibility, Squat jump with arm swing,Counter-movement jump with, and without the arm swing), to those that reach p<0,00 forvariables of the anthropometric space (Sitting height, Body mass, Chest Volume , Waistvolume, Hips, Upper leg, and Lower leg volume) and for variables of the space of motorskills (the Long jump, Medicine ball throw, “Sit and reach” test, the 5,15 and 20 meter run,T-test, Squat jump without arm swing and Squat jump with arms in the block position).Because the applied instruments validate the assumption that these instruments can be usedto isolate dimensions in experimental sample, and because these dimensions are significantfor success in a motor activity such as volleyball, the results of this research will have broadapplication, and thus are of both theoretical and practical importanc

Seasonal variation in the canopy color of temperate evergreen conifer forests

Evergreen conifer forests are the most prevalent land cover type in North America. Seasonal changes in the color of evergreen forest canopies have been documented with near‐surface remote sensing, but the physiological mechanisms underlying these changes, and the implications for photosynthetic uptake, have not been fully elucidated. Here, we integrate on‐the‐ground phenological observations, leaf‐level physiological measurements, near surface hyperspectral remote sensing and digital camera imagery, tower‐based CO₂ flux measurements, and a predictive model to simulate seasonal canopy color dynamics. We show that seasonal changes in canopy color occur independently of new leaf production, but track changes in chlorophyll fluorescence, the photochemical reflectance index, and leaf pigmentation. We demonstrate that at winter‐dormant sites, seasonal changes in canopy color can be used to predict the onset of canopy‐level photosynthesis in spring, and its cessation in autumn. Finally, we parameterize a simple temperature‐based model to predict the seasonal cycle of canopy greenness, and we show that the model successfully simulates interannual variation in the timing of changes in canopy color. These results provide mechanistic insight into the factors driving seasonal changes in evergreen canopy color and provide opportunities to monitor and model seasonal variation in photosynthetic activity using color‐based vegetation indices

Arctic soil methane sink increases with drier conditions and higher ecosystem respiration

Arctic wetlands are known methane (CH4) emitters but recent studies suggest that the Arctic CH4 sink strength may be underestimated. Here we explore the capacity of well-drained Arctic soils to consume atmospheric CH4 using >40,000 hourly flux observations and spatially distributed flux measurements from 4 sites and 14 surface types. While consumption of atmospheric CH4 occurred at all sites at rates of 0.092 ± 0.011 mgCH4 m−2 h−1 (mean ± s.e.), CH4 uptake displayed distinct diel and seasonal patterns reflecting ecosystem respiration. Combining in situ flux data with laboratory investigations and a machine learning approach, we find biotic drivers to be highly important. Soil moisture outweighed temperature as an abiotic control and higher CH4 uptake was linked to increased availability of labile carbon. Our findings imply that soil drying and enhanced nutrient supply will promote CH4 uptake by Arctic soils, providing a negative feedback to global climate change

The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data

The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible.Peer reviewe