TY  - JOUR
AU  - Lenhardt, Mirjana
AU  - Smederevac‐Lalić, Marija M.
AU  - Spasić, Slađana Z.
AU  - Honţ, Ştefan
AU  - Paraschiv, Marian
AU  - Iani, Marian I.
AU  - Nikčević, Miroslav V.
AU  - Klimley, Peter A.
AU  - Suciu, Radu
PY  - 2021
UR  - https://onlinelibrary.wiley.com/doi/10.1002/iroh.202002049
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/4186
AB  - The giant European catfish, Silurus glanis (total length = 200 cm; total weight ≈ 80 kg) was caught downstream of Iron Gate II hydropower dam (Danube River, 863 rkm) and tagged with an ultrasonic transmitter (V16TP; Vemco Ltd.) equipped with depth and temperature sensors. Changes in catfish diving behavior and temperature exposure were monitored over a period of roughly 2 years. Transmitter detections were recorded by nine autonomous receivers (VR2W, installed in 2015 between Serbia and Romania, as well as near Romanian shiplock and upstream Romanian turbines). The first signals were recorded on April 28, 2015 and the last on February 13, 2017. Altogether 59,355 and 59,175 detections of the catfish depth and water temperature were recorded, respectively. The greatest number of signals were recorded by the two receivers closest to the location where the catfish was caught, 72.3% and 27.1%, while only 0.6% of signals were recorded by other receivers. The mean catfish depth was 8.4 m, while minimum and maximum depths were 1.2 and 16.2 m. Results obtained showed that this catfish exhibited high site fidelity, while changes in depth at certain periods are possibly related to its search for prey and upstream migration during the spawning period. Hydropower dam and shiplock were obstacles on its migration upstream and telemetry studies could ensure habitat requirements and meet the development of restoration and conservation strategies for the fish resources in the future. K E Y W O R D S behavior, fish, large river, sensor, tag Abbreviations: CT, the catfish temperature; HPP, Hydro Power Plant; IG-I, Iron Gate I dam; IG-II, Iron Gate II dam; WT, Danube water temperature.
PB  - Wiley
T2  - International Review of Hydrobiology
T1  - Seasonal changes in depth position and temperature of European catfish ( Silurus glanis ) tracked by acoustic telemetry in the Danube River
DO  - 10.1002/iroh.202002049
SP  - iroh.202002049
ER  - 

@article{
author = "Lenhardt, Mirjana and Smederevac‐Lalić, Marija M. and Spasić, Slađana Z. and Honţ, Ştefan and Paraschiv, Marian and Iani, Marian I. and Nikčević, Miroslav V. and Klimley, Peter A. and Suciu, Radu",
year = "2021",
abstract = "The giant European catfish, Silurus glanis (total length = 200 cm; total weight ≈ 80 kg) was caught downstream of Iron Gate II hydropower dam (Danube River, 863 rkm) and tagged with an ultrasonic transmitter (V16TP; Vemco Ltd.) equipped with depth and temperature sensors. Changes in catfish diving behavior and temperature exposure were monitored over a period of roughly 2 years. Transmitter detections were recorded by nine autonomous receivers (VR2W, installed in 2015 between Serbia and Romania, as well as near Romanian shiplock and upstream Romanian turbines). The first signals were recorded on April 28, 2015 and the last on February 13, 2017. Altogether 59,355 and 59,175 detections of the catfish depth and water temperature were recorded, respectively. The greatest number of signals were recorded by the two receivers closest to the location where the catfish was caught, 72.3% and 27.1%, while only 0.6% of signals were recorded by other receivers. The mean catfish depth was 8.4 m, while minimum and maximum depths were 1.2 and 16.2 m. Results obtained showed that this catfish exhibited high site fidelity, while changes in depth at certain periods are possibly related to its search for prey and upstream migration during the spawning period. Hydropower dam and shiplock were obstacles on its migration upstream and telemetry studies could ensure habitat requirements and meet the development of restoration and conservation strategies for the fish resources in the future. K E Y W O R D S behavior, fish, large river, sensor, tag Abbreviations: CT, the catfish temperature; HPP, Hydro Power Plant; IG-I, Iron Gate I dam; IG-II, Iron Gate II dam; WT, Danube water temperature.",
publisher = "Wiley",
journal = "International Review of Hydrobiology",
title = "Seasonal changes in depth position and temperature of European catfish ( Silurus glanis ) tracked by acoustic telemetry in the Danube River",
doi = "10.1002/iroh.202002049",
pages = "iroh.202002049"
}

Lenhardt, M., Smederevac‐Lalić, M. M., Spasić, S. Z., Honţ, Ş., Paraschiv, M., Iani, M. I., Nikčević, M. V., Klimley, P. A.,& Suciu, R.. (2021). Seasonal changes in depth position and temperature of European catfish ( Silurus glanis ) tracked by acoustic telemetry in the Danube River. in International Review of Hydrobiology
Wiley., iroh.202002049.
https://doi.org/10.1002/iroh.202002049

Lenhardt M, Smederevac‐Lalić MM, Spasić SZ, Honţ Ş, Paraschiv M, Iani MI, Nikčević MV, Klimley PA, Suciu R. Seasonal changes in depth position and temperature of European catfish ( Silurus glanis ) tracked by acoustic telemetry in the Danube River. in International Review of Hydrobiology. 2021;:iroh.202002049.
doi:10.1002/iroh.202002049 .

Lenhardt, Mirjana, Smederevac‐Lalić, Marija M., Spasić, Slađana Z., Honţ, Ştefan, Paraschiv, Marian, Iani, Marian I., Nikčević, Miroslav V., Klimley, Peter A., Suciu, Radu, "Seasonal changes in depth position and temperature of European catfish ( Silurus glanis ) tracked by acoustic telemetry in the Danube River" in International Review of Hydrobiology (2021):iroh.202002049,
https://doi.org/10.1002/iroh.202002049 . .

TY  - JOUR
AU  - Stojadinović, Gordana
AU  - Martać, Ljiljana
AU  - Podgorac, Jelena
AU  - Spasić, Slađana Z.
AU  - Petković, Branka
AU  - Sekulić, Slobodan
AU  - Kesić, Srđan
PY  - 2020
UR  - http://www.serbiosoc.org.rs/arch/index.php/abs/article/view/5405
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/4005
AB  - A detailed analysis of the anesthetic-induced modulation of intracerebellar electrical activity is an important step to understand the functional brain responses to anesthesia. We examined the electrical activity recorded from different cortical layers: molecular layer (ML), Purkinje cell layer (PCL), granular layer (GL) and the white matter (WM) in the vermian part of rat cerebellar lobule V during Nembutal anesthesia using spectral and fractal analysis. Spectral analysis revealed a difference in the mean relative power of delta (0.1-4.0 Hz) and theta (4.1-8.0 Hz) frequencies through the cerebellar layers. Compared to the ML, delta activity increased significantly in the GL, while theta activity decreased in the GL and the WM. Fractal analysis revealed that the mean value of Higuchi’s fractal dimension (HFD) increased, starting from the ML to the WM. Theta activity exhibited a negative correlation with the HFD value in the ML. In contrast, the gamma activity showed a positive correlation with the HFD value in the ML and the GL. The combined use of spectral and fractal analyses revealed that Nembutal displays different effects on rat cerebellar electrical activity, which largely depends on the neurochemical and electrophysiological organization of the cerebellar layers.
PB  - Serbian Biological Society
T2  - Archives of Biological Sciences
T1  - The effects of Nembutal on the intracerebellar EEG activity revealed by spectral and fractal analysis
IS  - 3
VL  - 72
DO  - 10.2298/ABS200524036S
SP  - 425
EP  - 432
ER  - 

@article{
author = "Stojadinović, Gordana and Martać, Ljiljana and Podgorac, Jelena and Spasić, Slađana Z. and Petković, Branka and Sekulić, Slobodan and Kesić, Srđan",
year = "2020",
abstract = "A detailed analysis of the anesthetic-induced modulation of intracerebellar electrical activity is an important step to understand the functional brain responses to anesthesia. We examined the electrical activity recorded from different cortical layers: molecular layer (ML), Purkinje cell layer (PCL), granular layer (GL) and the white matter (WM) in the vermian part of rat cerebellar lobule V during Nembutal anesthesia using spectral and fractal analysis. Spectral analysis revealed a difference in the mean relative power of delta (0.1-4.0 Hz) and theta (4.1-8.0 Hz) frequencies through the cerebellar layers. Compared to the ML, delta activity increased significantly in the GL, while theta activity decreased in the GL and the WM. Fractal analysis revealed that the mean value of Higuchi’s fractal dimension (HFD) increased, starting from the ML to the WM. Theta activity exhibited a negative correlation with the HFD value in the ML. In contrast, the gamma activity showed a positive correlation with the HFD value in the ML and the GL. The combined use of spectral and fractal analyses revealed that Nembutal displays different effects on rat cerebellar electrical activity, which largely depends on the neurochemical and electrophysiological organization of the cerebellar layers.",
publisher = "Serbian Biological Society",
journal = "Archives of Biological Sciences",
title = "The effects of Nembutal on the intracerebellar EEG activity revealed by spectral and fractal analysis",
number = "3",
volume = "72",
doi = "10.2298/ABS200524036S",
pages = "425-432"
}

Stojadinović, G., Martać, L., Podgorac, J., Spasić, S. Z., Petković, B., Sekulić, S.,& Kesić, S.. (2020). The effects of Nembutal on the intracerebellar EEG activity revealed by spectral and fractal analysis. in Archives of Biological Sciences
Serbian Biological Society., 72(3), 425-432.
https://doi.org/10.2298/ABS200524036S

Stojadinović G, Martać L, Podgorac J, Spasić SZ, Petković B, Sekulić S, Kesić S. The effects of Nembutal on the intracerebellar EEG activity revealed by spectral and fractal analysis. in Archives of Biological Sciences. 2020;72(3):425-432.
doi:10.2298/ABS200524036S .

Stojadinović, Gordana, Martać, Ljiljana, Podgorac, Jelena, Spasić, Slađana Z., Petković, Branka, Sekulić, Slobodan, Kesić, Srđan, "The effects of Nembutal on the intracerebellar EEG activity revealed by spectral and fractal analysis" in Archives of Biological Sciences, 72, no. 3 (2020):425-432,
https://doi.org/10.2298/ABS200524036S . .

TY  - JOUR
AU  - Rašković, Božidar
AU  - Poleksić, Vesna
AU  - Skorić, Stefan
AU  - Jovičić, Katarina
AU  - Spasić, Slađana
AU  - Hegediš, Aleksandar
AU  - Vasić, Nebojša
AU  - Lenhardt, Mirjana
PY  - 2018
UR  - http://linkinghub.elsevier.com/retrieve/pii/S0147651318300691
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/2998
AB  - Chub (Squalius cephalus) specimens were collected in Korenita River seven months after spillover from the waste water of antimony mine tailing pond and compared with chub living in Kruščica reservoir (intended for water supply) and Međuvršje reservoir (influenced by intense emission of industrial, urban and rural wastewater). Concentrations of 15 elements (Al, As, B, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Si, Sr, Zn) were determined in muscle, liver and gills of chub by inductively coupled plasma optical spectrometry (ICP-OES) and histopathological alterations in liver and gills were assessed. Chub specimens from Korenita River had higher concentrations of As, Ba and Pb in all three investigated tissues as well as higher total histopathological index values than chub from reservoirs. Specimens from Međuvršje reservoir were characterized by higher values for concentrations of Cu and Si in muscle tissue and higher values for regressive histopathological alterations in gills. Individuals of chub from Kruščica reservoir had the highest concentrations of Fe in liver, Hg in muscle and Sr and Zn in muscle while gills had the lowest value of total histopathological index. The results from the present study showed higher level of histopathological alterations as a result of mine tailing accident. As a result of mixed contamination on the Međuvršje site, histopathological index values of gills were in line with the index value from Korenita River. Increased values for Fe and Sr in chub tissue from Kruščica reservoir could be explained by geological structure of the site which is characterized by magmatic rock rich in Cu, Fe and Ni as well as dominant carbonate sediment complex of marine origin with increased level of Sr.
T2  - Ecotoxicology and Environmental Safety
T1  - Effects of mine tailing and mixed contamination on metals, trace elements accumulation and histopathology of the chub (Squalius cephalus) tissues: Evidence from three differently contaminated sites in Serbia.
VL  - 153
DO  - 10.1016/j.ecoenv.2018.01.058
SP  - 238
EP  - 247
ER  - 

@article{
author = "Rašković, Božidar and Poleksić, Vesna and Skorić, Stefan and Jovičić, Katarina and Spasić, Slađana and Hegediš, Aleksandar and Vasić, Nebojša and Lenhardt, Mirjana",
year = "2018",
abstract = "Chub (Squalius cephalus) specimens were collected in Korenita River seven months after spillover from the waste water of antimony mine tailing pond and compared with chub living in Kruščica reservoir (intended for water supply) and Međuvršje reservoir (influenced by intense emission of industrial, urban and rural wastewater). Concentrations of 15 elements (Al, As, B, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Si, Sr, Zn) were determined in muscle, liver and gills of chub by inductively coupled plasma optical spectrometry (ICP-OES) and histopathological alterations in liver and gills were assessed. Chub specimens from Korenita River had higher concentrations of As, Ba and Pb in all three investigated tissues as well as higher total histopathological index values than chub from reservoirs. Specimens from Međuvršje reservoir were characterized by higher values for concentrations of Cu and Si in muscle tissue and higher values for regressive histopathological alterations in gills. Individuals of chub from Kruščica reservoir had the highest concentrations of Fe in liver, Hg in muscle and Sr and Zn in muscle while gills had the lowest value of total histopathological index. The results from the present study showed higher level of histopathological alterations as a result of mine tailing accident. As a result of mixed contamination on the Međuvršje site, histopathological index values of gills were in line with the index value from Korenita River. Increased values for Fe and Sr in chub tissue from Kruščica reservoir could be explained by geological structure of the site which is characterized by magmatic rock rich in Cu, Fe and Ni as well as dominant carbonate sediment complex of marine origin with increased level of Sr.",
journal = "Ecotoxicology and Environmental Safety",
title = "Effects of mine tailing and mixed contamination on metals, trace elements accumulation and histopathology of the chub (Squalius cephalus) tissues: Evidence from three differently contaminated sites in Serbia.",
volume = "153",
doi = "10.1016/j.ecoenv.2018.01.058",
pages = "238-247"
}

Rašković, B., Poleksić, V., Skorić, S., Jovičić, K., Spasić, S., Hegediš, A., Vasić, N.,& Lenhardt, M.. (2018). Effects of mine tailing and mixed contamination on metals, trace elements accumulation and histopathology of the chub (Squalius cephalus) tissues: Evidence from three differently contaminated sites in Serbia.. in Ecotoxicology and Environmental Safety, 153, 238-247.
https://doi.org/10.1016/j.ecoenv.2018.01.058

Rašković B, Poleksić V, Skorić S, Jovičić K, Spasić S, Hegediš A, Vasić N, Lenhardt M. Effects of mine tailing and mixed contamination on metals, trace elements accumulation and histopathology of the chub (Squalius cephalus) tissues: Evidence from three differently contaminated sites in Serbia.. in Ecotoxicology and Environmental Safety. 2018;153:238-247.
doi:10.1016/j.ecoenv.2018.01.058 .

Rašković, Božidar, Poleksić, Vesna, Skorić, Stefan, Jovičić, Katarina, Spasić, Slađana, Hegediš, Aleksandar, Vasić, Nebojša, Lenhardt, Mirjana, "Effects of mine tailing and mixed contamination on metals, trace elements accumulation and histopathology of the chub (Squalius cephalus) tissues: Evidence from three differently contaminated sites in Serbia." in Ecotoxicology and Environmental Safety, 153 (2018):238-247,
https://doi.org/10.1016/j.ecoenv.2018.01.058 . .

TY  - JOUR
AU  - Đikanović, Vesna
AU  - Skorić, Stefan
AU  - Spasić, Slađana
AU  - Naunović, Zorana
AU  - Lenhardt, Mirjana
PY  - 2018
UR  - https://www.sciencedirect.com/science/article/pii/S0269749118302033?via%3Dihub
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/3145
AB  - Metal content was evaluated in the sediment, macrophytes and fish in the Medjuvršje reservoir (Western Serbia). Concentrations of 16 trace elements (Ag; Al; As; B; Ba; Cd; Co; Cr; Cu; Fe; Li; Mn; Ni; Pb; Sr; Zn) were analysed in the sediment, macrophytes and fish of an aquatic ecosystem. Five macrophyte species and three fish tissues (liver, muscle, gills) from five fish species (freshwater bream, common nase, Prussian carp, chub, wels catfish) were sampled and the metal content was analysed with ICP-OES. The sediment concentrations of Cu, Cd, and Zn exceeded the Canadian sediment quality guidelines while concentrations of Cr and Ni were above the Netherlands' target values. Bioaccumulation factors (BSAF) were calculated for analysed macrophytes and fish tissue. The BSAF had higher values for macrophytes for all investigated elements except for Cu and Zn; Cu had a higher value in the liver of the freshwater bream (0.823) and Zn had a higher value in the liver of freshwater bream (0.914) and chub (0.834) as well as in gills of Prussian carp (2.58) and chub (1.26). Potamogeton pectinatus, Ceratophylum demersum and the root of Phragmites communis showed higher accumulation of elements than Trapa natans and Potamogeton fluitans and the body of P. communis. The highest BSAF values for Ba, Mn, Sr and Ni were recorded in the gills. Cd and Cu had the highest BSAF values in the liver. Results confirmed that particular macrophyte and fish species could be a good indicator of reservoir water and sediment pollution.
T2  - Environmental Pollution (Barking, Essex : 1987)
T1  - Ecological risk assessment for different macrophytes and fish species in reservoirs using biota-sediment accumulation factors as a useful tool.
VL  - 241
DO  - 10.1016/j.envpol.2018.06.054
SP  - 1167
EP  - 1174
ER  - 

@article{
author = "Đikanović, Vesna and Skorić, Stefan and Spasić, Slađana and Naunović, Zorana and Lenhardt, Mirjana",
year = "2018",
abstract = "Metal content was evaluated in the sediment, macrophytes and fish in the Medjuvršje reservoir (Western Serbia). Concentrations of 16 trace elements (Ag; Al; As; B; Ba; Cd; Co; Cr; Cu; Fe; Li; Mn; Ni; Pb; Sr; Zn) were analysed in the sediment, macrophytes and fish of an aquatic ecosystem. Five macrophyte species and three fish tissues (liver, muscle, gills) from five fish species (freshwater bream, common nase, Prussian carp, chub, wels catfish) were sampled and the metal content was analysed with ICP-OES. The sediment concentrations of Cu, Cd, and Zn exceeded the Canadian sediment quality guidelines while concentrations of Cr and Ni were above the Netherlands' target values. Bioaccumulation factors (BSAF) were calculated for analysed macrophytes and fish tissue. The BSAF had higher values for macrophytes for all investigated elements except for Cu and Zn; Cu had a higher value in the liver of the freshwater bream (0.823) and Zn had a higher value in the liver of freshwater bream (0.914) and chub (0.834) as well as in gills of Prussian carp (2.58) and chub (1.26). Potamogeton pectinatus, Ceratophylum demersum and the root of Phragmites communis showed higher accumulation of elements than Trapa natans and Potamogeton fluitans and the body of P. communis. The highest BSAF values for Ba, Mn, Sr and Ni were recorded in the gills. Cd and Cu had the highest BSAF values in the liver. Results confirmed that particular macrophyte and fish species could be a good indicator of reservoir water and sediment pollution.",
journal = "Environmental Pollution (Barking, Essex : 1987)",
title = "Ecological risk assessment for different macrophytes and fish species in reservoirs using biota-sediment accumulation factors as a useful tool.",
volume = "241",
doi = "10.1016/j.envpol.2018.06.054",
pages = "1167-1174"
}

Đikanović, V., Skorić, S., Spasić, S., Naunović, Z.,& Lenhardt, M.. (2018). Ecological risk assessment for different macrophytes and fish species in reservoirs using biota-sediment accumulation factors as a useful tool.. in Environmental Pollution (Barking, Essex : 1987), 241, 1167-1174.
https://doi.org/10.1016/j.envpol.2018.06.054

Đikanović V, Skorić S, Spasić S, Naunović Z, Lenhardt M. Ecological risk assessment for different macrophytes and fish species in reservoirs using biota-sediment accumulation factors as a useful tool.. in Environmental Pollution (Barking, Essex : 1987). 2018;241:1167-1174.
doi:10.1016/j.envpol.2018.06.054 .

Đikanović, Vesna, Skorić, Stefan, Spasić, Slađana, Naunović, Zorana, Lenhardt, Mirjana, "Ecological risk assessment for different macrophytes and fish species in reservoirs using biota-sediment accumulation factors as a useful tool." in Environmental Pollution (Barking, Essex : 1987), 241 (2018):1167-1174,
https://doi.org/10.1016/j.envpol.2018.06.054 . .

TY  - JOUR
AU  - Kesić, Srđan
AU  - Spasić, Slađana Z.
PY  - 2016
UR  - http://linkinghub.elsevier.com/retrieve/pii/S0169260715302923
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/3373
AB  - BACKGROUND AND OBJECTIVE For more than 20 years, Higuchi's fractal dimension (HFD), as a nonlinear method, has occupied an important place in the analysis of biological signals. The use of HFD has evolved from EEG and single neuron activity analysis to the most recent application in automated assessments of different clinical conditions. Our objective is to provide an updated review of the HFD method applied in basic and clinical neurophysiological research. METHODS This article summarizes and critically reviews a broad literature and major findings concerning the applications of HFD for measuring the complexity of neuronal activity during different neurophysiological conditions. The source of information used in this review comes from the PubMed, Scopus, Google Scholar and IEEE Xplore Digital Library databases. RESULTS The review process substantiated the significance, advantages and shortcomings of HFD application within all key areas of basic and clinical neurophysiology. Therefore, the paper discusses HFD application alone, combined with other linear or nonlinear measures, or as a part of automated methods for analyzing neurophysiological signals. CONCLUSIONS The speed, accuracy and cost of applying the HFD method for research and medical diagnosis make it stand out from the widely used linear methods. However, only a combination of HFD with other nonlinear methods ensures reliable and accurate analysis of a wide range of neurophysiological signals.
T2  - Computer Methods and Programs in Biomedicine
T2  - Computer Methods and Programs in Biomedicine
T1  - Application of Higuchi's fractal dimension from basic to clinical neurophysiology: A review.
VL  - 133
DO  - 10.1016/j.cmpb.2016.05.014
SP  - 55
EP  - 70
ER  - 

@article{
author = "Kesić, Srđan and Spasić, Slađana Z.",
year = "2016",
abstract = "BACKGROUND AND OBJECTIVE For more than 20 years, Higuchi's fractal dimension (HFD), as a nonlinear method, has occupied an important place in the analysis of biological signals. The use of HFD has evolved from EEG and single neuron activity analysis to the most recent application in automated assessments of different clinical conditions. Our objective is to provide an updated review of the HFD method applied in basic and clinical neurophysiological research. METHODS This article summarizes and critically reviews a broad literature and major findings concerning the applications of HFD for measuring the complexity of neuronal activity during different neurophysiological conditions. The source of information used in this review comes from the PubMed, Scopus, Google Scholar and IEEE Xplore Digital Library databases. RESULTS The review process substantiated the significance, advantages and shortcomings of HFD application within all key areas of basic and clinical neurophysiology. Therefore, the paper discusses HFD application alone, combined with other linear or nonlinear measures, or as a part of automated methods for analyzing neurophysiological signals. CONCLUSIONS The speed, accuracy and cost of applying the HFD method for research and medical diagnosis make it stand out from the widely used linear methods. However, only a combination of HFD with other nonlinear methods ensures reliable and accurate analysis of a wide range of neurophysiological signals.",
journal = "Computer Methods and Programs in Biomedicine, Computer Methods and Programs in Biomedicine",
title = "Application of Higuchi's fractal dimension from basic to clinical neurophysiology: A review.",
volume = "133",
doi = "10.1016/j.cmpb.2016.05.014",
pages = "55-70"
}

Kesić, S.,& Spasić, S. Z.. (2016). Application of Higuchi's fractal dimension from basic to clinical neurophysiology: A review.. in Computer Methods and Programs in Biomedicine, 133, 55-70.
https://doi.org/10.1016/j.cmpb.2016.05.014

Kesić S, Spasić SZ. Application of Higuchi's fractal dimension from basic to clinical neurophysiology: A review.. in Computer Methods and Programs in Biomedicine. 2016;133:55-70.
doi:10.1016/j.cmpb.2016.05.014 .

Kesić, Srđan, Spasić, Slađana Z., "Application of Higuchi's fractal dimension from basic to clinical neurophysiology: A review." in Computer Methods and Programs in Biomedicine, 133 (2016):55-70,
https://doi.org/10.1016/j.cmpb.2016.05.014 . .

TY  - JOUR
AU  - Kalauzi, Aleksandar
AU  - Spasić, Slađana Z.
AU  - Petrović, Jelena
AU  - Ćirić, Jelena
AU  - Šaponjić, Jasna
PY  - 2012
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/1175
AB  - This study was aimed to explore the sleep/wake states related cortico-pontine theta carrier frequency phase shift following a systemically induced chemical axotomy of the monoaminergic afferents within a brain of the freely moving rats. Our experiments were performed in 14 adult, male Sprague Dawley rats, chronically implanted for sleep recording. We recorded sleep during baseline condition, following sham injection (saline i.p. 1 ml/kg), and every week for 5 weeks following injection of the systemic neurotoxins (DSP-4 or PCA; 1 ml/kg, i.p.) for chemical axotomy of the locus coeruleus (LC) and dorsal raphe (DR) axon terminals. After sleep/wake states identification, FFT analysis was performed on 5 s epochs. Theta carrier frequency phase shift (Delta Phi) was calculated for each epoch by averaging theta Fourier component phase shifts, and the Delta Phi values were plotted for each rat in control condition and 28 days following the monoaminergic lesions, as a time for permanently established DR or LC chemical axotomy. Calculated group averages have shown that Delta Phi increased between pons and cortex significantly in all sleep/wake states (Wake, NREM and REM) following the monoaminergic lesions, with respect to controls. Monoaminergic lesions established the pontine leading role in the brain theta oscillations during all sleep/wake states.
T2  - General Physiology and Biophysics
T1  - Cortico-pontine theta carrier frequency phase shift across sleep/wake states following monoaminergic lesion in rat
IS  - 2
VL  - 31
EP  - 171
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_1175
ER  - 

@article{
author = "Kalauzi, Aleksandar and Spasić, Slađana Z. and Petrović, Jelena and Ćirić, Jelena and Šaponjić, Jasna",
year = "2012",
abstract = "This study was aimed to explore the sleep/wake states related cortico-pontine theta carrier frequency phase shift following a systemically induced chemical axotomy of the monoaminergic afferents within a brain of the freely moving rats. Our experiments were performed in 14 adult, male Sprague Dawley rats, chronically implanted for sleep recording. We recorded sleep during baseline condition, following sham injection (saline i.p. 1 ml/kg), and every week for 5 weeks following injection of the systemic neurotoxins (DSP-4 or PCA; 1 ml/kg, i.p.) for chemical axotomy of the locus coeruleus (LC) and dorsal raphe (DR) axon terminals. After sleep/wake states identification, FFT analysis was performed on 5 s epochs. Theta carrier frequency phase shift (Delta Phi) was calculated for each epoch by averaging theta Fourier component phase shifts, and the Delta Phi values were plotted for each rat in control condition and 28 days following the monoaminergic lesions, as a time for permanently established DR or LC chemical axotomy. Calculated group averages have shown that Delta Phi increased between pons and cortex significantly in all sleep/wake states (Wake, NREM and REM) following the monoaminergic lesions, with respect to controls. Monoaminergic lesions established the pontine leading role in the brain theta oscillations during all sleep/wake states.",
journal = "General Physiology and Biophysics",
title = "Cortico-pontine theta carrier frequency phase shift across sleep/wake states following monoaminergic lesion in rat",
number = "2",
volume = "31",
pages = "171",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_1175"
}

Kalauzi, A., Spasić, S. Z., Petrović, J., Ćirić, J.,& Šaponjić, J.. (2012). Cortico-pontine theta carrier frequency phase shift across sleep/wake states following monoaminergic lesion in rat. in General Physiology and Biophysics, 31(2).
https://hdl.handle.net/21.15107/rcub_ibiss_1175

Kalauzi A, Spasić SZ, Petrović J, Ćirić J, Šaponjić J. Cortico-pontine theta carrier frequency phase shift across sleep/wake states following monoaminergic lesion in rat. in General Physiology and Biophysics. 2012;31(2):null-171.
https://hdl.handle.net/21.15107/rcub_ibiss_1175 .

Kalauzi, Aleksandar, Spasić, Slađana Z., Petrović, Jelena, Ćirić, Jelena, Šaponjić, Jasna, "Cortico-pontine theta carrier frequency phase shift across sleep/wake states following monoaminergic lesion in rat" in General Physiology and Biophysics, 31, no. 2 (2012),
https://hdl.handle.net/21.15107/rcub_ibiss_1175 .

TY  - JOUR
AU  - Spasić, Slađana Z.
AU  - Nikolić, Ljiljana
AU  - Mutavdžić, Dragosav
AU  - Šaponjić, Jasna
PY  - 2011
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/1250
AB  - We applied a combination of fractal analysis and Independent Component Analysis (ICA) method to detect the sources of fractal complexity in snail Br neuron activity induced by static magnetic field of 2.7 mT. The fractal complexity of Br neuron activity was analyzed before (Control), during (MF), and after (AMF) exposure to the static magnetic field in six experimental animals. We estimated the fractal dimension (FD) of electrophysiological signals using Higuchi's algorithm, and empirical FD distributions. By using the Principal Component Analysis (PCA) and FastICA algorithm we determined the number of components, and defined the statistically independent components (ICs) in the fractal complexity of signal waveforms. We have isolated two independent components of the empirical FD distributions for each of three groups of data by using FastICA algorithm. ICs represent the sources of fractal waveforms complexity of Br neuron activity in particular experimental conditions. Our main results have shown that there could be two opposite intrinsic mechanisms in single snail Br neuron response to static magnetic field stimulation. We named identified ICs that correspond to those mechanisms - the component of plasticity and the component of elasticity. We have shown that combination of fractal analysis with ICA method could be very useful for the decomposition and identification of the sources of fractal complexity of bursting neuronal activity waveforms. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
T2  - Computer Methods and Programs in Biomedicine
T1  - Independent complexity patterns in single neuron activity induced by static magnetic field
IS  - 2
VL  - 104
EP  - 218
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_1250
ER  - 

@article{
author = "Spasić, Slađana Z. and Nikolić, Ljiljana and Mutavdžić, Dragosav and Šaponjić, Jasna",
year = "2011",
abstract = "We applied a combination of fractal analysis and Independent Component Analysis (ICA) method to detect the sources of fractal complexity in snail Br neuron activity induced by static magnetic field of 2.7 mT. The fractal complexity of Br neuron activity was analyzed before (Control), during (MF), and after (AMF) exposure to the static magnetic field in six experimental animals. We estimated the fractal dimension (FD) of electrophysiological signals using Higuchi's algorithm, and empirical FD distributions. By using the Principal Component Analysis (PCA) and FastICA algorithm we determined the number of components, and defined the statistically independent components (ICs) in the fractal complexity of signal waveforms. We have isolated two independent components of the empirical FD distributions for each of three groups of data by using FastICA algorithm. ICs represent the sources of fractal waveforms complexity of Br neuron activity in particular experimental conditions. Our main results have shown that there could be two opposite intrinsic mechanisms in single snail Br neuron response to static magnetic field stimulation. We named identified ICs that correspond to those mechanisms - the component of plasticity and the component of elasticity. We have shown that combination of fractal analysis with ICA method could be very useful for the decomposition and identification of the sources of fractal complexity of bursting neuronal activity waveforms. (C) 2011 Elsevier Ireland Ltd. All rights reserved.",
journal = "Computer Methods and Programs in Biomedicine",
title = "Independent complexity patterns in single neuron activity induced by static magnetic field",
number = "2",
volume = "104",
pages = "218",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_1250"
}

Spasić, S. Z., Nikolić, L., Mutavdžić, D.,& Šaponjić, J.. (2011). Independent complexity patterns in single neuron activity induced by static magnetic field. in Computer Methods and Programs in Biomedicine, 104(2).
https://hdl.handle.net/21.15107/rcub_ibiss_1250

Spasić SZ, Nikolić L, Mutavdžić D, Šaponjić J. Independent complexity patterns in single neuron activity induced by static magnetic field. in Computer Methods and Programs in Biomedicine. 2011;104(2):null-218.
https://hdl.handle.net/21.15107/rcub_ibiss_1250 .

Spasić, Slađana Z., Nikolić, Ljiljana, Mutavdžić, Dragosav, Šaponjić, Jasna, "Independent complexity patterns in single neuron activity induced by static magnetic field" in Computer Methods and Programs in Biomedicine, 104, no. 2 (2011),
https://hdl.handle.net/21.15107/rcub_ibiss_1250 .

TY  - JOUR
AU  - Spasić, Slađana Z.
AU  - Kalauzi, Aleksandar
AU  - Kesić, Srđan
AU  - Obradović, Milica
AU  - Šaponjić, Jasna
PY  - 2011
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/1247
AB  - We used spectral analysis and Higuchi fractal dimension (FD) to correlate the EEG spectral characteristics of the sensorimotor cortex, hippocampus, and pons with their corresponding EEG signal complexities in anesthetized rats. We have explored the quantitative relationship between the mean FDs and EEG wide range high frequency (8-50 Hz) activity during ketamine/xylazine versus nembutal anesthesia at surgical plane. Using FD we detected distinct inter-structure complexity pattern and uncovered for the first time that the polygraphically and behaviorally defined anesthetized state at surgical plane as equal during experiment in two anesthetic regimens, is not the same with respect to the degree of neuronal activity (degree of generalized neuronal inhibition achieved) at different brain levels. Using the correlation of certain brain structure EEG spectral characteristics with their corresponding FDs, and the surrogate data modeling, we determined what particular frequency band contributes to EEG complexities in ketamine/xylazine versus nembutal anesthesia. In this study we have shown that the quantitative relationship between higher frequency EEG amplitude and EEG complexity is the best-modeled by surrogate data as a 3rd order polynomial. On the base of our EEG amplitude/EEG complexity relationship model, and the evidenced spectral differences in ketamine versus nembutal anesthesia we have proved that higher amplitudes of sigma, beta, and gamma frequency in ketamine anesthesia yields to higher FDs. (C) 2011 Elsevier Ltd. All rights reserved.
T2  - Journal of Theoretical Biology
T1  - Surrogate data modeling the relationship between high frequency amplitudes and Higuchi fractal dimension of EEG signals in anesthetized rats
IS  - null
VL  - 289
EP  - 166
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_1247
ER  - 

@article{
author = "Spasić, Slađana Z. and Kalauzi, Aleksandar and Kesić, Srđan and Obradović, Milica and Šaponjić, Jasna",
year = "2011",
abstract = "We used spectral analysis and Higuchi fractal dimension (FD) to correlate the EEG spectral characteristics of the sensorimotor cortex, hippocampus, and pons with their corresponding EEG signal complexities in anesthetized rats. We have explored the quantitative relationship between the mean FDs and EEG wide range high frequency (8-50 Hz) activity during ketamine/xylazine versus nembutal anesthesia at surgical plane. Using FD we detected distinct inter-structure complexity pattern and uncovered for the first time that the polygraphically and behaviorally defined anesthetized state at surgical plane as equal during experiment in two anesthetic regimens, is not the same with respect to the degree of neuronal activity (degree of generalized neuronal inhibition achieved) at different brain levels. Using the correlation of certain brain structure EEG spectral characteristics with their corresponding FDs, and the surrogate data modeling, we determined what particular frequency band contributes to EEG complexities in ketamine/xylazine versus nembutal anesthesia. In this study we have shown that the quantitative relationship between higher frequency EEG amplitude and EEG complexity is the best-modeled by surrogate data as a 3rd order polynomial. On the base of our EEG amplitude/EEG complexity relationship model, and the evidenced spectral differences in ketamine versus nembutal anesthesia we have proved that higher amplitudes of sigma, beta, and gamma frequency in ketamine anesthesia yields to higher FDs. (C) 2011 Elsevier Ltd. All rights reserved.",
journal = "Journal of Theoretical Biology",
title = "Surrogate data modeling the relationship between high frequency amplitudes and Higuchi fractal dimension of EEG signals in anesthetized rats",
number = "null",
volume = "289",
pages = "166",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_1247"
}

Spasić, S. Z., Kalauzi, A., Kesić, S., Obradović, M.,& Šaponjić, J.. (2011). Surrogate data modeling the relationship between high frequency amplitudes and Higuchi fractal dimension of EEG signals in anesthetized rats. in Journal of Theoretical Biology, 289(null).
https://hdl.handle.net/21.15107/rcub_ibiss_1247

Spasić SZ, Kalauzi A, Kesić S, Obradović M, Šaponjić J. Surrogate data modeling the relationship between high frequency amplitudes and Higuchi fractal dimension of EEG signals in anesthetized rats. in Journal of Theoretical Biology. 2011;289(null):null-166.
https://hdl.handle.net/21.15107/rcub_ibiss_1247 .

Spasić, Slađana Z., Kalauzi, Aleksandar, Kesić, Srđan, Obradović, Milica, Šaponjić, Jasna, "Surrogate data modeling the relationship between high frequency amplitudes and Higuchi fractal dimension of EEG signals in anesthetized rats" in Journal of Theoretical Biology, 289, no. null (2011),
https://hdl.handle.net/21.15107/rcub_ibiss_1247 .

TY  - JOUR
AU  - Spasić, Slađana Z.
AU  - Kesić, Srđan
AU  - Kalauzi, Aleksandar
AU  - Šaponjić, Jasna
PY  - 2011
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/1303
AB  - The complexity, entropy and other non-linear measures of the electroencephalogram ( EEG), such as Higuchi fractal dimension (FD), have been recently proposed as the measures of anesthesia depth and sedation. We hypothesized that during unconciousness in rats induced by the general anesthetics with opposite mechanism of action, behaviorally and poligraphically controlled as appropriately achieved stable anesthesia, we can detect distinct inter-structure brain dynamic using mean FDs. We used the surrogate data test for nonlinearity in order to establish the existence of nonlinear dynamics, and to justify the use of FD as a nonlinear measure in the time series analysis. The surrogate data of predefined probability distribution and autocorrelation properties have been generated using the algorithm of statically transformed autoregressive process (STAP). FD then is applied to quantify EEG signal complexity at the cortical, hippocampal and pontine level during stable general anesthesia (ketamine/xylazine or nembutal anesthesia). Our study showed for the first time that global neuronal inhibition caused by different mechanisms of anesthetic action induced distinct brain inter- structure complexity gradient in Sprague Dawley rats. EEG signal complexities were higher at cortical and hippocampal level in ketamine/ xylazine vs. nembutal anesthesia, with the dominance of hippocampal complexity. In nembutal anesthesia the complexity dominance moved to pontine level, and ponto- hippocampocortical decreasing complexity gradient was established. This study has proved the Higuchi fractal dimension as a valuable tool for measuring the anesthesia induced inter- structure EEG complexity.
T2  - Fractals-Complex Geometry Patterns and Scaling in Nature and Society
T1  - Different Anesthesia in Rat Induces Distinct Inter-Structure Brain Dynamic Detected By Higuchi Fractal Dimension
IS  - 1
VL  - 19
EP  - 123
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_1303
ER  - 

@article{
author = "Spasić, Slađana Z. and Kesić, Srđan and Kalauzi, Aleksandar and Šaponjić, Jasna",
year = "2011",
abstract = "The complexity, entropy and other non-linear measures of the electroencephalogram ( EEG), such as Higuchi fractal dimension (FD), have been recently proposed as the measures of anesthesia depth and sedation. We hypothesized that during unconciousness in rats induced by the general anesthetics with opposite mechanism of action, behaviorally and poligraphically controlled as appropriately achieved stable anesthesia, we can detect distinct inter-structure brain dynamic using mean FDs. We used the surrogate data test for nonlinearity in order to establish the existence of nonlinear dynamics, and to justify the use of FD as a nonlinear measure in the time series analysis. The surrogate data of predefined probability distribution and autocorrelation properties have been generated using the algorithm of statically transformed autoregressive process (STAP). FD then is applied to quantify EEG signal complexity at the cortical, hippocampal and pontine level during stable general anesthesia (ketamine/xylazine or nembutal anesthesia). Our study showed for the first time that global neuronal inhibition caused by different mechanisms of anesthetic action induced distinct brain inter- structure complexity gradient in Sprague Dawley rats. EEG signal complexities were higher at cortical and hippocampal level in ketamine/ xylazine vs. nembutal anesthesia, with the dominance of hippocampal complexity. In nembutal anesthesia the complexity dominance moved to pontine level, and ponto- hippocampocortical decreasing complexity gradient was established. This study has proved the Higuchi fractal dimension as a valuable tool for measuring the anesthesia induced inter- structure EEG complexity.",
journal = "Fractals-Complex Geometry Patterns and Scaling in Nature and Society",
title = "Different Anesthesia in Rat Induces Distinct Inter-Structure Brain Dynamic Detected By Higuchi Fractal Dimension",
number = "1",
volume = "19",
pages = "123",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_1303"
}

Spasić, S. Z., Kesić, S., Kalauzi, A.,& Šaponjić, J.. (2011). Different Anesthesia in Rat Induces Distinct Inter-Structure Brain Dynamic Detected By Higuchi Fractal Dimension. in Fractals-Complex Geometry Patterns and Scaling in Nature and Society, 19(1).
https://hdl.handle.net/21.15107/rcub_ibiss_1303

Spasić SZ, Kesić S, Kalauzi A, Šaponjić J. Different Anesthesia in Rat Induces Distinct Inter-Structure Brain Dynamic Detected By Higuchi Fractal Dimension. in Fractals-Complex Geometry Patterns and Scaling in Nature and Society. 2011;19(1):null-123.
https://hdl.handle.net/21.15107/rcub_ibiss_1303 .

Spasić, Slađana Z., Kesić, Srđan, Kalauzi, Aleksandar, Šaponjić, Jasna, "Different Anesthesia in Rat Induces Distinct Inter-Structure Brain Dynamic Detected By Higuchi Fractal Dimension" in Fractals-Complex Geometry Patterns and Scaling in Nature and Society, 19, no. 1 (2011),
https://hdl.handle.net/21.15107/rcub_ibiss_1303 .

TY  - CONF
AU  - Spasić, Slađana Z.
AU  - Stojadinović, Gordana
AU  - Kalauzi, Aleksandar
AU  - Ćulić, Milka
AU  - Martać, Ljiljana
PY  - 2005
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/1715
AB  - We recorded electrocortical activity in anesthetized rats and constructed kmax new self-similar time series, applying Higuchi's algorithm. The aim of this study was to estimate value of the parameter k(max). in order to obtain fractal dimension values as an optimum measure of biosignal change. After our analysis, electrocortical activity recordings resulted in a family of curves f(k(max)). Three regions could be distinguished 2 <= k(max). < 8, with a U-shape; 8 <= k(max) <= 30, with a steeper quasilinear increase; and k(max) >= 30, with a smaller slope quasilinear increase. We suggest the optimum region for k(max): 8 < k(max) < 18, specifically k(max) = 8.
C3  - Biophysics from Molecules to Brain: in Memory of Radoslav K. Andjus
T1  - Estimation of parameter k(max) in fractal analysis of rat brain activity
IS  - null
VL  - 1048
EP  - 429
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_1715
ER  - 

@conference{
author = "Spasić, Slađana Z. and Stojadinović, Gordana and Kalauzi, Aleksandar and Ćulić, Milka and Martać, Ljiljana",
year = "2005",
abstract = "We recorded electrocortical activity in anesthetized rats and constructed kmax new self-similar time series, applying Higuchi's algorithm. The aim of this study was to estimate value of the parameter k(max). in order to obtain fractal dimension values as an optimum measure of biosignal change. After our analysis, electrocortical activity recordings resulted in a family of curves f(k(max)). Three regions could be distinguished 2 <= k(max). < 8, with a U-shape; 8 <= k(max) <= 30, with a steeper quasilinear increase; and k(max) >= 30, with a smaller slope quasilinear increase. We suggest the optimum region for k(max): 8 < k(max) < 18, specifically k(max) = 8.",
journal = "Biophysics from Molecules to Brain: in Memory of Radoslav K. Andjus",
title = "Estimation of parameter k(max) in fractal analysis of rat brain activity",
number = "null",
volume = "1048",
pages = "429",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_1715"
}

Spasić, S. Z., Stojadinović, G., Kalauzi, A., Ćulić, M.,& Martać, L.. (2005). Estimation of parameter k(max) in fractal analysis of rat brain activity. in Biophysics from Molecules to Brain: in Memory of Radoslav K. Andjus, 1048(null).
https://hdl.handle.net/21.15107/rcub_ibiss_1715

Spasić SZ, Stojadinović G, Kalauzi A, Ćulić M, Martać L. Estimation of parameter k(max) in fractal analysis of rat brain activity. in Biophysics from Molecules to Brain: in Memory of Radoslav K. Andjus. 2005;1048(null):null-429.
https://hdl.handle.net/21.15107/rcub_ibiss_1715 .

Spasić, Slađana Z., Stojadinović, Gordana, Kalauzi, Aleksandar, Ćulić, Milka, Martać, Ljiljana, "Estimation of parameter k(max) in fractal analysis of rat brain activity" in Biophysics from Molecules to Brain: in Memory of Radoslav K. Andjus, 1048, no. null (2005),
https://hdl.handle.net/21.15107/rcub_ibiss_1715 .

TY  - JOUR
AU  - Ćulić, Milka
AU  - Kalauzi, Aleksandar
AU  - Spasić, Slađana Z.
AU  - Stojadinović, Gordana
AU  - Martać, Ljiljana
PY  - 2005
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/1685
AB  - We propose a new method for calculating fractal dimension (DF) of a signal y(t), based on coefficients m(y)((n)), mean absolute values of its nth order derivatives (consecutive finite differences for sampled signals). We found that logarithms of m(y)((n)), = 2, 3,..., n(max), exhibited linear dependence on n: log (m(y)((n))) = (slope)n + Y(int) with stable slopes and Y-intercepts proportional to signal DF values. Using a family of Weierstrass functions, we established a link between Y-intercepts and signal fractal dimension: DF = A(n(max))Y(int) + B(n(max)), and calculated parameters A(n(max)) and B(n(max)) for n(max) = 3,..., 7. Compared to Higuchi's algorithm, advantages of this method include greater speed and eliminating the need to choose value for k(max), since the smallest error was obtained with n(max) = 3.
T2  - Fractals-Complex Geometry Patterns and Scaling in Nature and Society
T1  - Consecutive differences as a method of signal fractal analysis
IS  - 4
VL  - 13
EP  - 292
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_1685
ER  - 

@article{
author = "Ćulić, Milka and Kalauzi, Aleksandar and Spasić, Slađana Z. and Stojadinović, Gordana and Martać, Ljiljana",
year = "2005",
abstract = "We propose a new method for calculating fractal dimension (DF) of a signal y(t), based on coefficients m(y)((n)), mean absolute values of its nth order derivatives (consecutive finite differences for sampled signals). We found that logarithms of m(y)((n)), = 2, 3,..., n(max), exhibited linear dependence on n: log (m(y)((n))) = (slope)n + Y(int) with stable slopes and Y-intercepts proportional to signal DF values. Using a family of Weierstrass functions, we established a link between Y-intercepts and signal fractal dimension: DF = A(n(max))Y(int) + B(n(max)), and calculated parameters A(n(max)) and B(n(max)) for n(max) = 3,..., 7. Compared to Higuchi's algorithm, advantages of this method include greater speed and eliminating the need to choose value for k(max), since the smallest error was obtained with n(max) = 3.",
journal = "Fractals-Complex Geometry Patterns and Scaling in Nature and Society",
title = "Consecutive differences as a method of signal fractal analysis",
number = "4",
volume = "13",
pages = "292",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_1685"
}

Ćulić, M., Kalauzi, A., Spasić, S. Z., Stojadinović, G.,& Martać, L.. (2005). Consecutive differences as a method of signal fractal analysis. in Fractals-Complex Geometry Patterns and Scaling in Nature and Society, 13(4).
https://hdl.handle.net/21.15107/rcub_ibiss_1685

Ćulić M, Kalauzi A, Spasić SZ, Stojadinović G, Martać L. Consecutive differences as a method of signal fractal analysis. in Fractals-Complex Geometry Patterns and Scaling in Nature and Society. 2005;13(4):null-292.
https://hdl.handle.net/21.15107/rcub_ibiss_1685 .

Ćulić, Milka, Kalauzi, Aleksandar, Spasić, Slađana Z., Stojadinović, Gordana, Martać, Ljiljana, "Consecutive differences as a method of signal fractal analysis" in Fractals-Complex Geometry Patterns and Scaling in Nature and Society, 13, no. 4 (2005),
https://hdl.handle.net/21.15107/rcub_ibiss_1685 .

TY  - JOUR
AU  - Ćulić, Milka
AU  - Kalauzi, Aleksandar
AU  - Spasić, Slađana Z.
PY  - 2003
PY  - 2003
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/95
AB  - Simple, complex action potentials (AP) and interspike recorded background activity (RBA) were detected and extracted from 12 rat cerebellar cortical recordings. For each recording, an averaged simple action potential (SAP) was formed. Fourier amplitude spectra of SAP and RBA were similar in all recordings. For one of the recordings, a series of RBA simulations (SBA) was generated, superimposing random SAPs, varying the superposition frequency (fsup). Average Fourier amplitude, Amp(SBA), was calculated, in order to use Amp(SBA)=f(fsup) as a calibration line for reading fsup of RBA, which is a measure of the population activity. A probability distribution for SAP intensities was derived and a family of calibration lines constructed. As all lines were linear and parallel (slope S) in log-log plots, a population activity change could be calculated as fsup2/fsup1=[Amp2(RBA)/Amp(RBA)]1/S.
AB  - Jednostavni, složeni akcioni potencijali (AR) i međuspajkovna osnovna aktivnost (MOA) detektovani su i izdvojeni iz 12 registrovanih signala kore malog mozga pacova. Za svaku registraciju, formiran je usrednjeni jednostavni AR (JAR). Spektri Furijeovih amplituda JAR i MOA signala bili su slični kod svih registracija. Za jednu od registracija, superponiranjem slučajnih usrednjenih jednostavnih akcionih potencijala formiran je niz simulacija međuspajkovne osnovne aktivnosti (SOA), pri čemu je varirana frekvencija superpozicije (fsup). Izračunavana je srednja Furijeova amplituda, Amp(SBA), u cilju korišćenja Amp(SBA)=f(fsup) kao kalibracione linije za očitavanje fsup od MOA, što je mera za aktivnost populacije. Izvedena je raspodela verovatnoća za intenzitete JAR, pomoću koje je konstruisana familija kalibracionih linija. Kako su sve linije linearne i paralelne u log-log dijagramu, sa nagibom S, promena aktivnosti populacije može se izračunati kao fsup2/fsup1 =[Amp2(RBA)/Amp(RBA)]1/S.
T2  - Archives of Biological Sciences
T1  - Neki detalji metode za merenje promena aktivnosti neuronskih populacija
T1  - Some details on the method for measuring activity changes of neuronal populations
IS  - 3-4
VL  - 55
SP  - 71
EP  - 76
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_95
ER  - 

@article{
author = "Ćulić, Milka and Kalauzi, Aleksandar and Spasić, Slađana Z.",
year = "2003, 2003",
abstract = "Simple, complex action potentials (AP) and interspike recorded background activity (RBA) were detected and extracted from 12 rat cerebellar cortical recordings. For each recording, an averaged simple action potential (SAP) was formed. Fourier amplitude spectra of SAP and RBA were similar in all recordings. For one of the recordings, a series of RBA simulations (SBA) was generated, superimposing random SAPs, varying the superposition frequency (fsup). Average Fourier amplitude, Amp(SBA), was calculated, in order to use Amp(SBA)=f(fsup) as a calibration line for reading fsup of RBA, which is a measure of the population activity. A probability distribution for SAP intensities was derived and a family of calibration lines constructed. As all lines were linear and parallel (slope S) in log-log plots, a population activity change could be calculated as fsup2/fsup1=[Amp2(RBA)/Amp(RBA)]1/S., Jednostavni, složeni akcioni potencijali (AR) i međuspajkovna osnovna aktivnost (MOA) detektovani su i izdvojeni iz 12 registrovanih signala kore malog mozga pacova. Za svaku registraciju, formiran je usrednjeni jednostavni AR (JAR). Spektri Furijeovih amplituda JAR i MOA signala bili su slični kod svih registracija. Za jednu od registracija, superponiranjem slučajnih usrednjenih jednostavnih akcionih potencijala formiran je niz simulacija međuspajkovne osnovne aktivnosti (SOA), pri čemu je varirana frekvencija superpozicije (fsup). Izračunavana je srednja Furijeova amplituda, Amp(SBA), u cilju korišćenja Amp(SBA)=f(fsup) kao kalibracione linije za očitavanje fsup od MOA, što je mera za aktivnost populacije. Izvedena je raspodela verovatnoća za intenzitete JAR, pomoću koje je konstruisana familija kalibracionih linija. Kako su sve linije linearne i paralelne u log-log dijagramu, sa nagibom S, promena aktivnosti populacije može se izračunati kao fsup2/fsup1 =[Amp2(RBA)/Amp(RBA)]1/S.",
journal = "Archives of Biological Sciences",
title = "Neki detalji metode za merenje promena aktivnosti neuronskih populacija, Some details on the method for measuring activity changes of neuronal populations",
number = "3-4",
volume = "55",
pages = "71-76",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_95"
}

Ćulić, M., Kalauzi, A.,& Spasić, S. Z.. (2003). Neki detalji metode za merenje promena aktivnosti neuronskih populacija. in Archives of Biological Sciences, 55(3-4), 71-76.
https://hdl.handle.net/21.15107/rcub_ibiss_95

Ćulić M, Kalauzi A, Spasić SZ. Neki detalji metode za merenje promena aktivnosti neuronskih populacija. in Archives of Biological Sciences. 2003;55(3-4):71-76.
https://hdl.handle.net/21.15107/rcub_ibiss_95 .

Ćulić, Milka, Kalauzi, Aleksandar, Spasić, Slađana Z., "Neki detalji metode za merenje promena aktivnosti neuronskih populacija" in Archives of Biological Sciences, 55, no. 3-4 (2003):71-76,
https://hdl.handle.net/21.15107/rcub_ibiss_95 .

TY  - JOUR
AU  - Ćulić, Milka
AU  - Stojadinović, Gordana
AU  - Martać, Ljiljana
AU  - Todorović, Vera N.
AU  - Drndarević, Neda Č.
AU  - Nikolić-Judith, Anna
AU  - Kalauzi, Aleksandar
AU  - Spasić, Slađana Z.
PY  - 2002
PY  - 2002
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/462
AB  - Although there has been extensive research on the effect of IGF-I on muscles and bone tissue, the effect on brain aging has received little attention. We investigated the IGF-I content in brains of differently aged rats. The IGF-I contents in cerebellar and cerebral cortex were found to be higher in immature rats (4-5 days old) compared to young adult (2.5 months old) and middle-aged (7.5-9 months old) rats. However, the decrease of mean IGF-I in middle-aged rats compared to immature animals was statistically significant only in the cerebellar codex. Our results indicate that IGF-I content decreases through the lifespan and maybe selectively in some brain regions.
AB  - Vršena su istraživanja insulinu sličnog faktora rasta (IGF-I) na mišićno i koštano tkivo, ali je posvećena mala pažnja efektu na mozak u toku starenja. Mi smo ispitivali sadržaj IGF-I u moždanom tkivu pacova različite starosti. Nađeno je da su IGF-I koncentracije u kori malog mozga kao i velikog mozga mladih pacova (4-5 dana starih) više u poređenju sa sadržajima grupe tek-odraslih pacova starosti 2,5 meseca i grupe nešto starijih odraslih pacova (7,5-9 meseci starih). Međutim, smanjenje koncentracije IGF-I sadržaja samo u kori malog mozga nešto starijih pacova (7,5-9 meseci) bilo je značajno u odnosu na vrednosti u novorođenih (4-5 dana starih pacova). Naši rezultati ukazuju da IGF-I opada tokom života i moguće - selektivno u određenim moždanim regionima.
T2  - Acta veterinaria
T1  - Starosne promene u sadržaju insulin - sličnom faktora rasta i u mozgu pacova
T1  - Age-related changes in the content of insulin: Like growth factor-l in rat brain
IS  - 5-6
VL  - 52
SP  - 299
EP  - 304
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_462
ER  - 

@article{
author = "Ćulić, Milka and Stojadinović, Gordana and Martać, Ljiljana and Todorović, Vera N. and Drndarević, Neda Č. and Nikolić-Judith, Anna and Kalauzi, Aleksandar and Spasić, Slađana Z.",
year = "2002, 2002",
abstract = "Although there has been extensive research on the effect of IGF-I on muscles and bone tissue, the effect on brain aging has received little attention. We investigated the IGF-I content in brains of differently aged rats. The IGF-I contents in cerebellar and cerebral cortex were found to be higher in immature rats (4-5 days old) compared to young adult (2.5 months old) and middle-aged (7.5-9 months old) rats. However, the decrease of mean IGF-I in middle-aged rats compared to immature animals was statistically significant only in the cerebellar codex. Our results indicate that IGF-I content decreases through the lifespan and maybe selectively in some brain regions., Vršena su istraživanja insulinu sličnog faktora rasta (IGF-I) na mišićno i koštano tkivo, ali je posvećena mala pažnja efektu na mozak u toku starenja. Mi smo ispitivali sadržaj IGF-I u moždanom tkivu pacova različite starosti. Nađeno je da su IGF-I koncentracije u kori malog mozga kao i velikog mozga mladih pacova (4-5 dana starih) više u poređenju sa sadržajima grupe tek-odraslih pacova starosti 2,5 meseca i grupe nešto starijih odraslih pacova (7,5-9 meseci starih). Međutim, smanjenje koncentracije IGF-I sadržaja samo u kori malog mozga nešto starijih pacova (7,5-9 meseci) bilo je značajno u odnosu na vrednosti u novorođenih (4-5 dana starih pacova). Naši rezultati ukazuju da IGF-I opada tokom života i moguće - selektivno u određenim moždanim regionima.",
journal = "Acta veterinaria",
title = "Starosne promene u sadržaju insulin - sličnom faktora rasta i u mozgu pacova, Age-related changes in the content of insulin: Like growth factor-l in rat brain",
number = "5-6",
volume = "52",
pages = "299-304",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_462"
}

Ćulić, M., Stojadinović, G., Martać, L., Todorović, V. N., Drndarević, N. Č., Nikolić-Judith, A., Kalauzi, A.,& Spasić, S. Z.. (2002). Starosne promene u sadržaju insulin - sličnom faktora rasta i u mozgu pacova. in Acta veterinaria, 52(5-6), 299-304.
https://hdl.handle.net/21.15107/rcub_ibiss_462

Ćulić M, Stojadinović G, Martać L, Todorović VN, Drndarević NČ, Nikolić-Judith A, Kalauzi A, Spasić SZ. Starosne promene u sadržaju insulin - sličnom faktora rasta i u mozgu pacova. in Acta veterinaria. 2002;52(5-6):299-304.
https://hdl.handle.net/21.15107/rcub_ibiss_462 .

Ćulić, Milka, Stojadinović, Gordana, Martać, Ljiljana, Todorović, Vera N., Drndarević, Neda Č., Nikolić-Judith, Anna, Kalauzi, Aleksandar, Spasić, Slađana Z., "Starosne promene u sadržaju insulin - sličnom faktora rasta i u mozgu pacova" in Acta veterinaria, 52, no. 5-6 (2002):299-304,
https://hdl.handle.net/21.15107/rcub_ibiss_462 .