An Application of Kolmogorov Complexity and Its Spectrum to Positive Surges

A positive surge is associated with a sudden change in flow that increases the water depth and modifies flow structure in a channel. Positive surges are frequently observed in artificial channels, rivers, and estuaries. This paper presents the application of Kolmogorov complexity and its spectrum to the velocity data collected during the laboratory investigation of a positive surge. Two types of surges were considered: a undular surge and a breaking surge. For both surges, the Kolmogorov complexity (KC) and Kolmogorov complexity spectrum (KCS) were calculated during the unsteady flow (US) associated with the passage of the surge as well as in the preceding steady-state (SS) flow condition. The results show that, while in SS, the vertical distribution of KC for Vx is dominated by the distance from the bed, with KC being the largest at the bed and the lowest at the free surface; in US only the passage of the undular surge was able to drastically modify such vertical distribution of KC resulting in a lower and constant randomness throughout the water depth. The analysis of KCS revealed that Vy values were peaking at about zero, while the distribution of Vx values was related both to the elevation from the bed and to the surge type. A comparative analysis of KC and normal Reynold stresses revealed that these metrics provided different information about the changes observed in the flow as it moves from a steady-state to an unsteady-state due to the surge passage. Ultimately, this preliminary application of Kolmogorov complexity measures to a positive surge provides some novel findings about such intricate hydrodynamics processes

Stability of Intercelular Exchange of Biochemical Substances Affected by Variability of Environmental Parameters

Communication between cells is realized by exchange of biochemical substances. Due to internal organization of living systems and variability of external parameters, the exchange is heavily influenced by perturbations of various parameters at almost all stages of the process. Since communication is one of essential processes for functioning of living systems it is of interest to investigate conditions for its stability. Using previously developed simplified model of bacterial communication in a form of coupled difference logistic equations we investigate stability of exchange of signaling molecules under variability of internal and external parameters.Comment: 11 pages, 3 figure

Calibration model for near infrared spectroscopy (NIRS) for assessment of forage pea (Pisum sativum L.) composition

Bliska infracrvena spektroskopija (NIRS) se koristi za analizu hemijskih svojstava poljoprivrednih proizvoda bez prethodne pripreme uzorka. U ovom radu razvijen je kalibracioni model za merenje proteina i vlage za celo zrno i brašno stočnog graška. Dobijeni spektri obrađeni su kombinovanjem matematičkih modela (PLSR, MSC, prvog i drugog izvoda) i računate kalibracione greške. Greške pri merenju vlage celog zrna su u granicama (od -0,8 do 0,8) i brašna (od -0,7 do 0,8); pri merenju proteina celog zrna greške su (od -1,6 do 1,8) i brašna (od -2 do 2). Ovim ispitivanjem se dokazalo da je moguće odrediti količine proteina i vlage pomoću NIRS metode a dobijene greške se tolerišu i kalibracioni model je primenjiv u praksi.Near infrared spectroscopy (NIRS) is used to analyze the chemical properties of agricultural products with no sample prepation. In this paper, a calibration model was developed to measure protein and moisture of forage pea in the whole seed and flour. The obtained spectra were processed by combining mathematical models (PLSR, MSC, first and second derivative) and calculating calibration errors. Measuring errors of the whole seed moisture are from (-0.8 to 0.8) and flour from (-0.7 to 0.8); measuring errors of the whole seed protein are from (-1.6 to 1.8) and flour from (-2 to 2). This test proves the possibility to determine protein and moisture via NIRS, errors are tolerated and the calibration model is applicable

Grain yield potential of spring dry pea varieties

Field peas are mostly used for animal nutrition in the Balkan region and in the countries of the former USSR, while in the countries of Western Europe, Canada, the USA and the Middle East they are mostly used for human nutrition. Over three years (2010-2012), the yield and grain yield components of the most widespread field pea varieties were examined. The lowest number of plants was determined in 'NS Junior' intended for combined use (65 plants/m2), while 'Dukat' and 'Partner' had 88 and 85 plants/m2 on average, respectively. The average stem height was 158 cm for 'NS Junior', and 65 and 70 cm for 'Dukat' and 'Partner', respectively. 'Dukat' (4846 kg/ha) and 'Partner' (4521 kg/ha) had significantly higher grain yields compared with 'NS Junior' (2717 kg/ha). The content of crude protein in the grain was highest in 'NS Junior' (27.6%), while 'Dukat' and 'Partner' had lower contents (23-25%).Proteinski grašak se uglavnom koristi za ishranu životinja u našem regionu i u zemljama bivšeg SSSR-a, dok se u zemljama zapadne Evrope, Kanade, SAD-a i Bliskog istoka najviše koristi za ishranu ljudi. Tokom tri godine (2010-2012) ispitivane su komponente prinosa i prinos zrna najrasprostranjenijih sorti proteinskog graška. Najmanji broj biljaka utvrđen je kod sorte NS Junior, namenjene za kombinovanu upotrebu (65 biljaka / m2), dok su sorte Dukat i Partner imale u proseku 88 i 85 biljaka / m2. Prosečna visina stabljike za sortu NS Junior iznosila je 158 cm, a za sorte Dukat i Partner 65 i 70 cm. Sorte Dukat (4846 kg / ha) i Partner (4521 kg / ha) imale su znatno veći prinos zrna u poređenju sa sortom NS Junior (2717 kg / ha). Sadržaj sirovih proteina u zrnu bio je najveći kod sorte NS Junior (27,6%), dok su sorte Dukat i Partner imale između 23 i 25%

Proizvodnja kabaste stočne hrane

Nedostatak dovoljnih količina kvalitetne kabaste stočne hrane danas je verovatno najveći problem u ishrani preživara. Kabasta hraniva se karakterišu time što imaju veći udeo vlakana (iznad 18% sirove celuloze), voluminozna su i u osnovi predstavljaju vegetativni deo različitih biljnih vrsta. Zastupljenost dostupne (svarljive) energije u ovim hranivima je niža po jedinici mase ili zapremine nego kod koncentrata. Kvalitet kabastih hraniva uslovljen je ponajviše biološkom pripadnošću krmne kulture i fazom razvića. Svi sistemi normiranja obroka u ishrani preživara polaze od toga da dobro izbalansiran obrok omogućuje da životinje bolje konzumiraju i iskoriste hranu. Trave i leguminoze su osnovna kabasta hraniva i čine 2/3 suve materije obroka. Ako se koriste na pravi način, ova kabasta hraniva su veoma dobar izvor proteina, karotina, kalcijuma i drugih minerala

Centaurium erythraea extract reduces redox imbalance and improves insulin expression and secretion in pancreatic β-cells exposed to oxidative and nitrosative stress

Oxidative stress is one of the major mechanisms that underlies the damage of pancreatic b-cells and defects in insulin secretion in diabetes. As herbal preparations can alleviate oxidative stress through their redox-active secondary metabolites, in this study we investigated the cytoprotective effects of Centaurium erythraea extract (CEe) against H2O2- and SNP-induced oxidative/nitrosative stress in Rin-5F b-cells. The antioxidant activity of CEe and its effect on cell survival and insulin expression/secretion were evaluated. The CEe increased cell viability and ameliorated the disturbance of redox homeostasis in H2O2- and SNP-treated cells by decreasing DNA damage, lipid peroxidation and protein S-glutathionylation. The CEe restored GSH homeostasis in H2O2-treated b-cells and attenuated the SNP-induced disturbance of the GSH/GSSG ratio. The H2O2- and SNP-induced disruption of CAT, GPx, GR, MnSOD and CuZnSOD activities was adjusted by the CEe towards control values, as well as mRNA and protein levels of GPx, MnSOD and CAT. The CEe increased insulin expression/secretion particularly in H2O2-treated b-cells, which was in accordance with the more pronounced antioxidant effect of the CEe observed in H2O2-treated b-cells as compared to SNP-treated cells. These findings support the beneficial effect of the CEe in preventing or slowing down b-cell damage and dysfunction caused by oxidative/nitrosative stress during diabetes development

Centaurium erythraea extract mediates prosurvival pathways and insulin expression in STZ-treated beta-cells

Diabetes is characterized by hyperglycaemia resulting from a deficiency in insulin secretion and/or action leading to severe diabetic complications. Despite numerous efforts, recovery and maintenance of functional beta-cells is still an unresolved task in diabetes therapy. Considering anti-diabetic properties of medicinal herb Centaurium erythraea Rafn (CE), this study aimed to analyze protective effects of the CE extract on Rin-5F beta-cell line exposed to diabetogenic agent streptozotocin (STZ). Cytoprotective concentration of CE extract (0.25 mg/mL) and IC50 dose of STZ (12mM) were determined using cell viability assay (MTT). The level of insulin mRNA and the concentration of insulin released from beta-cells in a culture medium were analyzed by RT-qPCR and ELISA, respectively. Activity of Akt, ERK and p38 kinases, as well as nuclear levels of islet-enriched Pdx1 and MafA proteins were assessed by Western blot analysis. In comparison to STZ-treated cells, CE extract/STZ co-treatment increased viability of Rin- 5F cells for 12%. STZ-treated beta-cells displayed reduced mRNA level of insulin to 63% and reduced insulin secretion to 76% in comparison to controls, while application of CE extract improved insulin mRNA level to 77% and insulin secretion to 90% of the control level. Improved viability and functionality of beta-cells could be ascribed to a CE extractmediated modulation of the activities of pro-survival Akt, ERK and p38 kinases and Pdx- 1 and MafA factors involved in regulation of beta-cell proliferation and insulin expression/secretion. The results of this study suggest that CE extract promotes proliferative and pro-survival pathways in beta-cells and improves their functional properties

Aktuelni sortiment NS krmnog bilja za 2020. godinu

U cilju intenziviranja stočarske proizvodnje, rešenje treba tražiti u gajenju visoko prinosnih krmnih biljaka dobrog kvaliteta. Zajedno sa naporima da se smanji energetska potrošnja, zagađenje životne sredine i intenziviraju sistemi održive poljoprivrede, treba razmotriti mogućnost povećanja površina pod ovim biljnim kulturama. Dominantan način iskorišćavanja krmnih biljaka je proizvodnja kabaste stočne hrane (zelena krma, seno, senaža i silaža) sa izuzetkom proteinskog graška koji se koristi za proizvodnju zrna. Značajan doprinos u proizvodnji kvalitetne i raznovrsne stočne hrane u Republici Srbiji pripada Odeljenju za krmno bilje čiju osnovnu delatnost čini naučnoistraživački rad, oplemenjivanje i stvaranje novih sorti lucerke, crvene deteline, stočnog graška, grahorice, stočnog kelja, krmnog sirka i sudanske trave

CXC chemokine ligand 12α-mediated increase in insulin secretion and survival of mouse pancreatic islets in response to oxidative stress through modulation of calcium uptake

We examined whether CXCL12α improves insulin secretion by influencing the Ca2+ oscillation pattern and Ca2+ influx ([Ca2+]i), thereby enhancing the viability of pancreatic islet cells in oxidative stress. The islets of Langerhans were isolated from male OF1 mice and pretreated with 40 ng/mL of CXCL12α prior to exposure to 7.5 μM hydrogen peroxide, which served to induce oxidative stress. Incubation of islets with CXCL12α induced pancreatic β-cell proliferation and improved the ability of β-cells to withstand oxidative stress. Consecutive treatments of isolated islets with hydrogen peroxide caused a decline in β-cell functioning over time, while the CXCL12α pretreatment of islets exhibited a physiological response to high glucose that was comparable to control islets. The attenuated response of islets to a high D-glucose challenge was observed as a partial to complete abolishment of [Ca2+]i. Treatments with increasing concentrations of CXCL12α decreased the number of Ca2+ oscillations that lasted longer, thus pointing to an overall increase in [Ca2+]i, which was followed by increased insulin secretion. In addition, treatment of islets with CXCL12α enhanced the transcription rate for insulin and the CXCR4 gene, pointing to the importance of CXCL12/CXCR4 signaling in the regulation of Ca2+ intake and insulin secretion in pancreatic islet cells. We propose that a potential treatment with CXCL12α could help to remove preexisting glucotoxicity and associated temporary β-cell stunning that might be present at the time of diabetes diagnosis in vivo

Absence of PARP-1 affects Cxcl12 expression by increasing DNA demethylation.

Poly [ADP-ribose] polymerase 1 (PARP-1) has an inhibitory effect on C-X-C motif chemokine 12 gene (Cxcl12) transcription. We examined whether PARP-1 affects the epigenetic control of Cxcl12 expression by changing its DNA methylation pattern. We observed increased expression of Cxcl12 in PARP-1 knock-out mouse embryonic fibroblasts (PARP1-/-) in comparison to wild-type mouse embryonic fibroblasts (NIH3T3). In the Cxcl12 gene, a CpG island is present in the promoter, the 5' untranslated region (5' UTR), the first exon and in the first intron. The methylation state of Cxcl12 in each cell line was investigated by methylation-specific PCR (MSP) and high resolution melting analysis (HRM). Both methods revealed strong demethylation in PARP1-/- compared to NIH3T3 cells in all four DNA regions. Increased expression of the Ten-eleven translocation (Tet) genes in PARP1-/- cells indicated that TETs could be important factors in Cxcl12 demethylation in the absence of PARP-1, accounting for its increased expression. Our results showed that PARP-1 was a potential upstream player in (de)methylation events that modulated Cxcl12 expression