Detection of intentionally made changes in image content

Digital images and video signals represent the most frequently transmitted contents. Namely, with the development of modern digital cameras and smartphones, the use of multimedia content increases every day. They are used in everyday life, for getting information and also as authenticated proofs or corroboratory evidence in different areas like: forensic studies, law enforcement, journalism and others...Multifraktalna analiza se pokazala kao dobar alat za analizu postojećih slika, kao i segmentaciju određenih regiona, izdvajanje ivica, uglova slike i slično. Kako kopirani i nalepljeni delovi imaju sličnu strukturu, može se primeniti multifraktalna analiza, koja u osnovi analizira samosličnost. Multifraktalni spektar daje globalni opis slike (ili, opštije, fenomena koji se ispituje). Vrednost Hölder-ovog eksponenta zavisi od položaja u strukturi i opisuje lokalnu regularnost signala. Naime, različiti objekti na slici imaju različite spektre, različite pozicije maksimuma, minimuma, prve nule itd, što se pokazalo kao interesantan skup različitih parametara pomoću kojih se mogu detektovati namerne promene na slikama..

Multielement determination using inductively coupled plasma optical emission spectrometry for metal characterization of water from artesian wells in Semberija region: Multivariate analysis of data

The concentrations of fifteen metals (Mg, Na, Ca, K, Se, Zn, Mn, Fe, Pb, Cr, Cu, Cd, Sb, Ni, Co) were determined in water from ten artesian wells (AW) in Semberija to obtain a general metal profile of water in this region. Principal components analysis (PCA) was used in this classification. Using principal component analysis two factors controlling the metal variability were obtained, which accounted for nearly 71.5% of the total variance. Natural (lithogenic) factor is represented by PC1, while anthropogenic factor is represented by PC2. PC1 with high contribution of Mn, Mg, Na, K, Ca, Zn and Se accounting for 41.84% of the total variance, while PC2 exhibits high loading for Cd, Ni, Sb, Cr and Pb (29.66%). Three general areas (clusters) with different metal characteristics were detected. Water from artesian wells in first cluster (AW1, AW2, AW3, AW4, AW5 and AW6) had much higher metal concentration compared with those in the second (AW7, AW8 and AW9) and third cluster (AW10). That is as a result of anthropogenic inputs. Also, the analysis of water demonstrated slightly elevated values for Mn (concentrations up to 0.176 mg/L), while concentrations of the other investigated elements are below the values recommended by the World Health Organization (WHO) and the United States Environmental Protection Agency (US EPA). [Projekat Ministarstva nauke Republike Srbije, br. 172047

The Influence of Synthesis Parameters and Heat Effect on Magnetic Properties of Powder System FexOy - BaTiO3

Powder mixture of 60 mass % of iron (Fe) and 40 mass % of barium titanate (BaTiO3) has been activated in planetary mill for 100, 120, 150, 180, 210 and 240 min in the air. During the activation the iron powder transits into iron oxides FeO, Fe2O3 and Fe3O4. Depending on the activation time the percentage of iron oxides varies. Simultaneously, with the content change of the activated system, magnetic properties change as well. The thermomagnetic measurements in the temperature interval from 200C up to 6200C have shown that the powder activated for 120 minutes exhibits maximum magnetization prior to annealing. After multiple annealings of the same sample it has been shown that the maximum magnetization of the cooled sample is obtained upon annealing at 5600C during 10 min for all activation times of as-cast powder sample. The sample obtained from pressed powder mixture activated for 120 min has the maximum magnetization, upon isothermal sintering of samples at 12000C during 2h, being M = 2,9 Am2/kg. With additional annealing of the same sample up to Curie temperature (TC = 4300C) and subsequent cooling of the sample in the magnetic field of H = 20 kA/m, the sample is permanently magnetized. The magnetization of sample cooled in the magnetic field with intensity of 20 kA/m being M = 10,15 Am2/kg

EFFECT OF STORAGE TEMPERATURE AND THERMAL PROCESSING ON CATECHINS, PROCYANIDINS AND TOTAL FLAVONOIDS STABILITY IN COMMERCIALLY AVAILABLE COCOA POWDERS

Storage stability of catechin, epicatechin, procyanidins B1-B4 and total flavonoids in cocoa powder samples was studied over the temperature range 4-35 ºC. Thermal stability of total flavonoids was studied over the temperature range 95-125 ºC. Total flavonoids concentration decreased as a function of time and the degradation was accelerated at higher temperatures: a half-life (t1/2) of total flavonoids was much shorter at room temperature than during cold storage. A first-order kinetic model fitted well to all the data. Temperature dependence of the degradation rate constants, described by the Arrhenius equation, was more pronounced during heating than during storage. In the temperature interval from 4 ºC to 35 ºC, the calculated activation energies (Ea) for catechin, epicatechin and procyanidins B1-B4 were 20.4 kJ/mol, 12.5 kJ/mol, 9.4 kJ/mol, 21.6 kJ/mol, 19.4 kJ/mol, 23.7 kJ/mol, respectively. UTICAJ TEMPERTURE ČUVANJA I ZAGREVANJA NA SADRŽAJ KATEHINA; PROCIJANIDINA I UKUPNIH FENOLA KOMERCIJALNIM UZORCIMA KAKAOA U PRAHUUticaj temperature čuvanja na stabilnost katehina, epikatehina, procijanidina B1-B4 i ukupnih flavonoida u uzorcima kakaoa u prahu praćen je u temperaturnom opsegu od 4 ºC do 35 ºC. Uticaj zagrevanja na sadržaj ukupnih flavonoida je praćen u temperaturnom opsegu od 95 ºC do 125 ºC. U toku skladištenja uzoraka je došlo do smanjenja u sadržaju ukupnih flavonoida. Pomenuta promena je bila izraženija na višim temperaturama: vreme polu-života (t1/2) ukupnih flavonoida u ispitivanom uzorku kakaoa u prahu bilo je kraće kada je on čuvan na sobnoj temperaturi nego kada je čuvan u frižideru. Promene u sadržaju flavonoida u ispitivanim uzorcima prate kinetiku prvog reda. Konstante brzine degradacije, izračunate pomoću Arenijusove jednačine, veće su tokom zagrevanja nego tokom čuvanja ispitivanih uzoraka na nižim temperaturama. Izračunate energije aktivacije (Ea) za katehin, epikatehin i procijanidine B1, B2, B3 i B4 u temperaturnom intevalu od 4 ºC do 35 ºC  bile su: 20,4 kJ/mol, 12,5 kJ/mol, 9,4 kJ/mol, 21,6 kJ/mol, 19,4 kJ/mol i 23,7 kJ/mol. HIGHLIGHTS Storage stability of (epi)catechin, procyanidins B1-B4 and total flavonoids in cocoa powder samples was studied(temperature range 4-35 °C)The stability of the total flavonoids was studied over the temperature range 95-125 °CThe degradation of the total flavonoids was significantly accelerated at higher temperaturesTemperature dependence of the degradation rate constants was more pronounced during heating than during storag

Određivanje antioksidativnog kapaciteta uzoraka kakao praha, crne i mliječne čokolade pomoću cikličke voltametrije: korelacija s rezultatima spektrofotometrijskog ispitivanja i udjelima pojedinačnih fenolnih spojeva

Phenolic antioxidants in cocoa powder, dark chocolate and milk chocolate samples are quantified electrochemically using cyclic voltammetry with a glassy carbon electrode. Cyclic voltammograms were recorded from 0 to 800 mV at a scan rate of 100 mV/s. Phenolics with an ortho-diphenol group show the first oxidation peak in the potential range between 370 and 460 mV (vs. Ag/AgCl) in 0.1 mol/L of the acetate buffer, pH=4. The first and third anodic current peaks, close to 670 mV, can be ascribed to the first and second oxidation of the catechin-type flavonoids that are present at a high concentration in samples. The second peak at around 560 mV can be ascribed to phenolic acids. Procyanidins B1, B2, B3 and B4 did not have any visible waves. Strong positive correlation was established between antioxidant activities deduced from cyclic voltammograms with those determined using spectrophotometric assays. HPLC method was used for the quantification of individual phenolic compounds.Fenolni su antioksidansi u uzorcima kakao praha, tamne i mliječne čokolade elektrokemijski određeni pomoću cikličke voltametrije, primjenom elektrode od staklastog ugljika. Ciklički su voltamogrami snimljeni u rasponu od 0 do 800 mV, pri brzini skeniranja od 100 mV/s. Fenolni su spojevi s orto-difenilnom grupom dali prvi oksidacijski pik pri potencijalu između 370 i 460 mV (u usporedbi s referentnom elektrodom Ag/AgCl) u acetatnom puferu koncentracije od 0,1 mol/L, pH=4. Prvi i treći anodni pikovi, dobiveni pri otprilike 670 mV, potječu od prve i druge oksidacije katehina, prisutnih u većim udjelima u ispitivanim uzorcima. Drugi pik, dobiven pri otprilike 560 mV, potječe od fenolnih kiselina. Procijanidini B1, B2, B3 i B4 nisu dali vidljive pikove. Utvrđena je jaka pozitivna korelacija između antioksidativne aktivnosti određene cikličkom voltametrijom i one određene spektrofotometrijom. Za određivanje udjela pojedinačnih fenolnih spojeva upotrijebljena je metoda HPLC

Hybrid Nanoscale Materials for Convergent Technologies

The convergence of nano-, bio-, and information technologies is based on the understanding of complex hierarchical structures and systems, as well as on the material unity at the nanoscale and on technology integration from that scale. A growing interest in these technologies is a result of their potential to provide solutions to numerous societal challenges, such as advanced healthcare, environmental remediation, sustainable development, and adoption of cyber-physical systems based on the Internet of Things and the Internet of Systems. Taking into account that hybrid nanomaterials possess extraordinary physical and chemical properties derived from their size in the nanoscale, the aim of this work is to present the connection between processing parameters and multifunctional properties of nano scale hybrid materials, focusing on the study of ceramic-polymer structures before they can be nano-engineered into functional devices. The unique functionality of these nanostructures has enabled their applications in numerous devices such as: micro and nano-electro-mechanical systems (MEMS/NEMS), sensors, microactuators, surface acoustic wave devices, polymer electrolyte membrane fuel cells, switches, thermistors, resonators and filters, electrooptic devices, etc. In this study special attention has been paid to their applications in the fields of electronics, biotechnology, environmental protection and remediation

National identity predicts public health support during a global pandemic (vol 13, 517, 2022) : National identity predicts public health support during a global pandemic (Nature Communications, (2022), 13, 1, (517), 10.1038/s41467-021-27668-9)

Publisher Copyright: © The Author(s) 2022.In this article the author name ‘Agustin Ibanez’ was incorrectly written as ‘Augustin Ibanez’. The original article has been corrected.Peer reviewe

National identity predicts public health support during a global pandemic.

Changing collective behaviour and supporting non-pharmaceutical interventions is an important component in mitigating virus transmission during a pandemic. In a large international collaboration (Study 1, N = 49,968 across 67 countries), we investigated self-reported factors associated with public health behaviours (e.g., spatial distancing and stricter hygiene) and endorsed public policy interventions (e.g., closing bars and restaurants) during the early stage of the COVID-19 pandemic (April-May 2020). Respondents who reported identifying more strongly with their nation consistently reported greater engagement in public health behaviours and support for public health policies. Results were similar for representative and non-representative national samples. Study 2 (N = 42 countries) conceptually replicated the central finding using aggregate indices of national identity (obtained using the World Values Survey) and a measure of actual behaviour change during the pandemic (obtained from Google mobility reports). Higher levels of national identification prior to the pandemic predicted lower mobility during the early stage of the pandemic (r = -0.40). We discuss the potential implications of links between national identity, leadership, and public health for managing COVID-19 and future pandemics

Predicting attitudinal and behavioral responses to COVID-19 pandemic using machine learning

At the beginning of 2020, COVID-19 became a global problem. Despite all the efforts to emphasize the relevance of preventive measures, not everyone adhered to them. Thus, learning more about the characteristics determining attitudinal and behavioral responses to the pandemic is crucial to improving future interventions. In this study, we applied machine learning on the multinational data collected by the International Collaboration on the Social and Moral Psychology of COVID-19 (N = 51,404) to test the predictive efficacy of constructs from social, moral, cognitive, and personality psychology, as well as socio-demographic factors, in the attitudinal and behavioral responses to the pandemic. The results point to several valuable insights. Internalized moral identity provided the most consistent predictive contribution—individuals perceiving moral traits as central to their self-concept reported higher adherence to preventive measures. Similar results were found for morality as cooperation, symbolized moral identity, self-control, open-mindedness, and collective narcissism, while the inverse relationship was evident for the endorsement of conspiracy theories. However, we also found a non-neglible variability in the explained variance and predictive contributions with respect to macro-level factors such as the pandemic stage or cultural region. Overall, the results underscore the importance of morality-related and contextual factors in understanding adherence to public health recommendations during the pandemic.Peer reviewe