59 research outputs found
Electronic Tests in High Education-Opportunities and Challenges
Checking and evaluation of knowledge of the students is an important segment in educational process. Paper presents application of electronic tests in student’s exams, its creation, scoring and evaluation by using web based software for creation of electronic tests. Electronic tests are implemented in April exam term, year 2014. Comparison is made between archived student outcomes in April exam term when electronic tests are used and February exam term when they were not used. This was a pilot project implemented on only one subject in one exam term but it has opened the wide doors for further implementation of information technology in high education especially in achieved knowledge evaluation since it has proved to be very effective, objective and time-saving way for student grading
Exploring the trigonometric circle and trigonometric laws with a GeoGebra visualization
Mathematical functions that establish a relationship between the angles of a right triangle and the lengths of its sides are known as trigonometric functions. In this project, we will explore two of the six trigonometric functions and their properties using the trigonometric circle. Initially, trigonometric functions were defined only for acute angles related to right triangles. To extend the
sine and cosine functions to functions whose domain is the entire real line, geometric definitions using the unit circle with radius 1 are often used. Then, the domain of the other trigonometric functions is the real line with some isolated points removed. Modern definitions express trigonometric functions as infinite series or as solutions of differential equations. This allows the extension of the definition of sine and cosine functions to the entire complex plane and the definition of other trigonometric functions on the complex plane with some isolated points removed. This project discusses the use of GeoGebra in studying trigonometric functions, the Law of Sine, and Law of Cosine. GeoGebra is a powerful mathematical software that allows for the visualization and exploration of trigonometric functions
Forest protected area management in Serbia and realisation of conservation objectives
U radu je analizirano gazdovanje šumama u zaštićenim područjima u Srbiji, posmatrajući: 1) ekološke efekte gazdovanja, i 2) procese prilagođavanja gazdovanja konzervacionim potrebama. Površina zaštićenih područja je značajno porasla, ali ima malo informacija o njihovom doprinosu u realizaciji konzervacionih ciljeva. Pošto se u većini zaštićenih šumskih područja u Evropi aktivno gazduje, i dozvoljeno je korišćenje drvne biomase, informacije o efektima gazdovanja su neophodne. Glavna barijera u ekološkim evaluacijama gazdovanja je nepostojanje indikatora kojima bi se mogle izmeriti promene u ekosistemu, a koje nastaju kao rezultat primenjenih mera gazdovanja. Poslednjih godina se sve više ističe potencijal primene funkcionalnih indikatora, tj. indikatora koji se oslanjaju na informacije o funkcionalnim karakteristikama vrsta. U radu je stoga primenjen funkcionalni pristup za analizu ekološkog efekta gazdovanja. U te svrhe su odabrane karakteristike koje se povezuju sa sposobnošću vrsta za brzo usvajanje ili konzervisanje resursa, tj. određuju odgovor vrsta na promene u dostupnim resursima, a koje, na primer, nastaju usled uklanjanja drvne biomase: visina, specifična površina lista, sadržaj suve materije lista, sadržaj ukupnog azota i ukupnog fosfora. Iste se dovode i u vezu sa primarnom produktivnošću i dekompozicijom, procesima od značaja za očuvanje integriteta ekosistema. Pošto analiza odgovora funkcionalnih indikatora zahteva duži vremenski period posmatranja, u radu je osmišljen drugačiji pristup za izvođenje eksperimenta. U te svrhe su iskorišćeni Landsat satelitski snimci, tj. tri snimka sa vremenskim razmakom od 10 godina: 1994., 2005. i 2015. godina. Izvršena je digitalna klasifikacija snimaka prema sastavu šuma, nakon čega su detektovane promene u sastavu šuma za period od ukupno 20 godina. Ovi podaci su spojeni sa podacima o funkcionalnim karakteristikama vrsta, kako bi se utvrdile promene u funkcionalnoj kompoziciji. Poslednji korak je bio formiranje modela šumske krune, kroz koji je određen intenzitet seče. Koristeći podatke o promenama u gustini krune i promenama u funkcionalnoj kompoziciji, sproveden je eksperiment, tj. analiza efekta različitih nivoa intenziteta seče na promene u funkcionisanju šumskog ekosistema. Za sprovođenje ovog eksperimenta je odabran samo jedan deo Fruške gore, jer je cilj bio da se osmisli pristup za evaluaciju, prilagođen trenutnom konceptu gazdovan ja zaštićenim šumskim područjima, i ispita njegova praktičnost. Kao propratni podatak ovoj analizi, sprovedena je i komparativna analiza upravljača zaštićenih šumskih područja u Srbiji, kako bi se ispitao nivo ulaganja u konzervacione sposobnosti, kao ključnog procesa u implementaciji konzervacionih ciljeva. U digitalnoj klasifikaciji je postignuta visokapreciznost, sa ukupnom preciznošću 94,5% i Kapa koeficijentom 0,93. Potpuno spektralno razdvajanje je postignuto samo za Q. petraea od Tilia tomentosa, i sastojina u kojima se kao dominantne pojavljuju F. silvatica i Tilia tomentosa. Utvđeno je prodiranje F. moesiaca u šume Q. petraea, i apsolutno širenje vrste Tilia tomentosa, posebno u periodu nakon 2005. godine, a koja prema podacima o karakteristikama vrsta ima najveću kompetetivnu sposobnost u odnosu na druge ispitivane vrste drveća. Rezultati modela gustine krune ukazuju na postepeno proređivanje šume od 1994. ka 2015. godini, sa potpunim nestankom šuma guste krune na prelazu između 1994. i 2005. godine. Utvrđen je značajan efekat proređivanja šume na promene u funkcionalnoj kompoziciji. Sa višim intenzitetom proređivanja, CWM indikator se pomerio od konzervativnih karakteristika ka onima koje ukazuju na dominaciju vrsta sklonih brzom sticanju resursa. Prelaz koji je imao značajnog efekta na promene je prelaz iz šume sa gustinom krune većom od 65% u šumu gustine krune između 50-65%, a što bi moglo ukazivati i na prelaz u drugi režim funkcionisanja ekosistema. Konzervacioni ciljevi su još uvek slabo integrisani u gazdovanje šumama u zaštićenim područjima.In this work, the forest management in protected areas of Serbia was analysed, following: 1) ecologic effects of management and 2) investments in capabilities essential for integration of conservation objectives. The size of protected areas has significantly grown, but there is a little information on their contribution to real conservation goals. Since in most of European protected forest areas is employed active management, the information on ecological effects of management is necessary. The main barrier in ecologic evaluations of managing is the absence of indicators, which could measure the changes in ecosystem, resulting from applied measures. Recently, the potentiality of functional indicators is more emphasized, i.e. indicators, which lean on information about functional traits of species. So, in this work functional approach was taken to analyse ecologic effects of forest management. For this sake were chosen characteristics, which are connected to capabilities of specie s to acquire or conserve resources, i.e. define the answer of the species on changes in available resources, caused by elimination of wooden mass, i.e. logging: height, specific leaf area, leaf dry matter cont ent, nitrogen content and phosphorus content. The same are connected to the processes of significance for conservation of ecosystem integrity (net primary productivity and decomposition). Since the analysis of functional indicators response demands a longer period of observation, another attitude of performing the experiment was conceptualized. For that purpose Landsat satellite image was used, i.e. three images in interval of ten years: 1994, 2005, and 2015. A digital image classification of forest composition was performed, after which the changes in forest composition were detected over the period of 20 years. These data were then connected with the data on functional characteristics of species to determine changes in functional composition. The last step was forming of forest canopy density model, through which was determined the intensity of logging. Using data on changes of forest canopy density model and changes in functional composition, an experiment was performed, i.e. analysis of effects of different levels of logging intensity on changes in forest ecosystem function. For the performing of this experiment was chosen just a part of Fruska gora, as the goal was to try to construct the evaluation approach, adapted to momentary concept of managing in protected forest areas and inspect its feasibility. As an accompanying data with this analysis was performed a comparative analysis of protected forest area managers in Serbia, to examine the level of investments in conservation capabilities, as the key process in implementing conservation goals
Forest protected area management in Serbia and realisation of conservation objectives
U radu je analizirano gazdovanje šumama u zaštićenim područjima u Srbiji, posmatrajući: 1) ekološke efekte gazdovanja, i 2) procese prilagođavanja gazdovanja konzervacionim potrebama. Površina zaštićenih područja je značajno porasla, ali ima malo informacija o njihovom doprinosu u realizaciji konzervacionih ciljeva. Pošto se u većini zaštićenih šumskih područja u Evropi aktivno gazduje, i dozvoljeno je korišćenje drvne biomase, informacije o efektima gazdovanja su neophodne. Glavna barijera u ekološkim evaluacijama gazdovanja je nepostojanje indikatora kojima bi se mogle izmeriti promene u ekosistemu, a koje nastaju kao rezultat primenjenih mera gazdovanja. Poslednjih godina se sve više ističe potencijal primene funkcionalnih indikatora, tj. indikatora koji se oslanjaju na informacije o funkcionalnim karakteristikama vrsta. U radu je stoga primenjen funkcionalni pristup za analizu ekološkog efekta gazdovanja. U te svrhe su odabrane karakteristike koje se povezuju sa sposobnošću vrsta za brzo usvajanje ili konzervisanje resursa, tj. određuju odgovor vrsta na promene u dostupnim resursima, a koje, na primer, nastaju usled uklanjanja drvne biomase: visina, specifična površina lista, sadržaj suve materije lista, sadržaj ukupnog azota i ukupnog fosfora. Iste se dovode i u vezu sa primarnom produktivnošću i dekompozicijom, procesima od značaja za očuvanje integriteta ekosistema. Pošto analiza odgovora funkcionalnih indikatora zahteva duži vremenski period posmatranja, u radu je osmišljen drugačiji pristup za izvođenje eksperimenta. U te svrhe su iskorišćeni Landsat satelitski snimci, tj. tri snimka sa vremenskim razmakom od 10 godina: 1994., 2005. i 2015. godina. Izvršena je digitalna klasifikacija snimaka prema sastavu šuma, nakon čega su detektovane promene u sastavu šuma za period od ukupno 20 godina. Ovi podaci su spojeni sa podacima o funkcionalnim karakteristikama vrsta, kako bi se utvrdile promene u funkcionalnoj kompoziciji. Poslednji korak je bio formiranje modela šumske krune, kroz koji je određen intenzitet seče. Koristeći podatke o promenama u gustini krune i promenama u funkcionalnoj kompoziciji, sproveden je eksperiment, tj. analiza efekta različitih nivoa intenziteta seče na promene u funkcionisanju šumskog ekosistema. Za sprovođenje ovog eksperimenta je odabran samo jedan deo Fruške gore, jer je cilj bio da se osmisli pristup za evaluaciju, prilagođen trenutnom konceptu gazdovan ja zaštićenim šumskim područjima, i ispita njegova praktičnost. Kao propratni podatak ovoj analizi, sprovedena je i komparativna analiza upravljača zaštićenih šumskih područja u Srbiji, kako bi se ispitao nivo ulaganja u konzervacione sposobnosti, kao ključnog procesa u implementaciji konzervacionih ciljeva. U digitalnoj klasifikaciji je postignuta visokapreciznost, sa ukupnom preciznošću 94,5% i Kapa koeficijentom 0,93. Potpuno spektralno razdvajanje je postignuto samo za Q. petraea od Tilia tomentosa, i sastojina u kojima se kao dominantne pojavljuju F. silvatica i Tilia tomentosa. Utvđeno je prodiranje F. moesiaca u šume Q. petraea, i apsolutno širenje vrste Tilia tomentosa, posebno u periodu nakon 2005. godine, a koja prema podacima o karakteristikama vrsta ima najveću kompetetivnu sposobnost u odnosu na druge ispitivane vrste drveća. Rezultati modela gustine krune ukazuju na postepeno proređivanje šume od 1994. ka 2015. godini, sa potpunim nestankom šuma guste krune na prelazu između 1994. i 2005. godine. Utvrđen je značajan efekat proređivanja šume na promene u funkcionalnoj kompoziciji. Sa višim intenzitetom proređivanja, CWM indikator se pomerio od konzervativnih karakteristika ka onima koje ukazuju na dominaciju vrsta sklonih brzom sticanju resursa. Prelaz koji je imao značajnog efekta na promene je prelaz iz šume sa gustinom krune većom od 65% u šumu gustine krune između 50-65%, a što bi moglo ukazivati i na prelaz u drugi režim funkcionisanja ekosistema. Konzervacioni ciljevi su još uvek slabo integrisani u gazdovanje šumama u zaštićenim područjima.In this work, the forest management in protected areas of Serbia was analysed, following: 1) ecologic effects of management and 2) investments in capabilities essential for integration of conservation objectives. The size of protected areas has significantly grown, but there is a little information on their contribution to real conservation goals. Since in most of European protected forest areas is employed active management, the information on ecological effects of management is necessary. The main barrier in ecologic evaluations of managing is the absence of indicators, which could measure the changes in ecosystem, resulting from applied measures. Recently, the potentiality of functional indicators is more emphasized, i.e. indicators, which lean on information about functional traits of species. So, in this work functional approach was taken to analyse ecologic effects of forest management. For this sake were chosen characteristics, which are connected to capabilities of specie s to acquire or conserve resources, i.e. define the answer of the species on changes in available resources, caused by elimination of wooden mass, i.e. logging: height, specific leaf area, leaf dry matter cont ent, nitrogen content and phosphorus content. The same are connected to the processes of significance for conservation of ecosystem integrity (net primary productivity and decomposition). Since the analysis of functional indicators response demands a longer period of observation, another attitude of performing the experiment was conceptualized. For that purpose Landsat satellite image was used, i.e. three images in interval of ten years: 1994, 2005, and 2015. A digital image classification of forest composition was performed, after which the changes in forest composition were detected over the period of 20 years. These data were then connected with the data on functional characteristics of species to determine changes in functional composition. The last step was forming of forest canopy density model, through which was determined the intensity of logging. Using data on changes of forest canopy density model and changes in functional composition, an experiment was performed, i.e. analysis of effects of different levels of logging intensity on changes in forest ecosystem function. For the performing of this experiment was chosen just a part of Fruska gora, as the goal was to try to construct the evaluation approach, adapted to momentary concept of managing in protected forest areas and inspect its feasibility. As an accompanying data with this analysis was performed a comparative analysis of protected forest area managers in Serbia, to examine the level of investments in conservation capabilities, as the key process in implementing conservation goals
Conditioned Extreme, Determination and Visualization
In mathematics, and especially in the application of mathematics in a number of areas, problems and tasks are encountered in which extremes of function are required, with the variables being bound up with some additional conditions. Extremes of this kind are called conditional extremes. [2]. In this paper, we present the procedure for determining a conditional extremity of a function with two variables, we will present that the point is finding the curve in the space obtained as a cross section on two surfaces and by using free software we will have visualization of the conditional extremum.
Key words: Conditioned extreme, function, point, visualization
Mitochondrial DNA Deletions: Quantitative Evaluation of Single and Multiple Deletions Generations and Expansion in Single Cells
Mitochondria are unique organelles, containing their own, maternally inherited genome. Human mitochondrial DNA (mtDNA) is small, circular and intronless, encoding 37 genes, precisely 13 proteins of the respiratory chain, 22 transfer RNAs (tRNAs) and 2 ribosomal RNAs. Each mitochondrion contains several mtDNA copies. Mitochondrial DNA deletions are pathogenic mutations that remove various portions of mtDNA genome, leading to shorter mtDNA molecules. In patients, there are two classes of mtDNA deletions: single, large-scale deletions that are present from the birth, whereas multiple deletions accumulate with age secondarily to mutations in nuclear genes involved in mtDNA maintenance. Every deleted mtDNA, coexists with other wild type mtDNAs, in an intracellular pool of mitochondrial genomes, determining the condition known as heteroplasmy. Pathogenic mtDNA mutations may become prevalent in certain cells; this process is defined as intracellular clonal expansion.
This study investigates clonal expansion patterns of mtDNA deleted genomes, applying for the first time the droplet-digital polymerase chain reaction (ddPCR) approach on single muscle cells collected by laser-capture microdissection from muscle biopsies of patients with different paradigms of mitochondrial disease with single and multiple mtDNA deletions accumulation. The results of this study indicate different patterns of accumulation of clonally expanded mtDNA deletions in patients with single and multiple deletions. It was found that single deletions patients have clonally expanded deletion in all single muscle cell populations, suggesting that the original deletion event occurred at early stage of embryonic development or even along the maternal germline transmission. Importantly, we distinguish localized clonal expansion of mtDNA deletions in patients with mutations in the OPA1 fusion gene. In conclusion, the ddPCR is a promising new technique for the investigation of clonal expansion by accurate of mtDNA deletions by accurate quantifying the mtDNA heteroplasmy levels
Application of Newton’s Backward Interpolation Using Wolfram Mathematica
Interpolation is one of the most basic and most useful numerical techniques. It constitutes an irreplaceable tool during work with tabular or graphical functions. The Newton’s backward interpolation is one of most important numerical techniques which have huge application in mathematics, computer science and technical science. This paper provides an analytical description of Newton's backward interpolation and how Wolfram Mathematica software can be used to solve the problems from Newton's backward interpolation
Contemporary Views of Iron Homeostasis with Main Focus of Hepcidin - New Hormone Regulator of Iron Metabolism
Железото е еÑенцијален елемент за Ñкоро Ñите живи организми. Тој е клучен функционален дел на киÑлородните транÑпортери, депонирачките молекули и многу ензими кои ја катализираат Ñ€ÐµÐ´Ð¾ÐºÑ Ñ€ÐµÐ°ÐºÑ†Ð¸Ñ˜Ð°Ñ‚Ð° неопходна за генерирање на енергија, продукти на различни метаболички интермедиери и за одбрана. ИÑтражувањата покажаа дека клучен регулатор во хомеоÑтазата на железото е хепцидинот и го поÑтавија црниот дроб за централен орган во ÑиÑтемÑката хомеоÑтаза на железото. Хепцидинот е катјонÑки пептид ÑоÑтавен од 25 амино киÑелини и 4 диÑулфидни врÑки. Ðеодамна беше откриено дека циркулирачкиот хепцидин Ñо релативно виÑок афинитет е врзан за α2-макроглобулин и Ñо релативно низок афинитет Ñо албуминот. Во прилог на Ñвојата улога во регулирањето на ÑиÑтемÑкиот метаболизам на железо, хепцидинот може да придонеÑе за одбраната на домаќинот. Хепцидинот првично беше идентификуван како антимикробен пептид и беше откриено дека може индиректно да придонеÑе за одбраната на домаќинот преку намалување на концентрацијата на железо во плазмата.Iron is an essential element of almost all living organisms. It is key functional part of oxygen transporters, depositary molecules and many enzymes which catalyze redox reactions necessary to generate the energy, products of various metabolic intermediates and defense. Studies have shown that a key regulator of iron homeostasis is hepcidin and set the liver as the central authority in the system of iron homeostasis. Hepcidin is cationic peptide composed of 25 amino acids and four disulfide bonds. Recently it was revealed that circulating hepcidin with a relatively high affinity is bound to α2-macroglobulin and with relatively low affinity is bound to albumin. In addition to its role in regulation systemic metabolism of iron, hepcidinot can contribute to host defense. Hepcidinot was originally identified as an antimicrobial peptide and found that it could indirectly contribute to host defense by reducing the concentration of iron in plasma
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