Role of Band 3 in the Erythrocyte Membrane Structural Changes Under Isotonic and Hypotonic Conditions

An attempt was made to discuss and connect various modeling approaches which have been proposed in the literature in order to shed further light on the erythrocyte membrane relaxation under isotonic and hypotonic conditions. Roles of the main membrane constituents: (1) the actin‐spectrin cortex, (2) the lipid bilayer, and (3) the transmembrane protein band 3 and its course‐consequence relations were considered to estimate the membrane relaxation phenomena. Cell response to loading conditions includes the successive sub‐bioprocesses: (1) erythrocyte local or global deformation, (2) the cortex‐bilayer coupling, and (3) the rearrangements of band 3. The results indicate that the membrane structural changes include: (1) the spectrin flexibility distribution and (2) the rate of its changes influenced by the number of band 3 molecules attached to spectrin filaments, and phosphorylation of the actin‐spectrin junctions. Band 3 rearrangement also influences: (1) the effective bending modulus and (2) the band 3‐bilayer interaction energy and on that base the bilayer bending state. The erythrocyte swelling under hypotonic conditions influences the bilayer integrity which leads to the hemolytic hole formation. The hemolytic hole represents the excited cluster of band 3 molecules

Cell jamming and unjamming in development: physical aspects

Collective cell migration is essential for a wide range of biological processes such as: morphogenesis, wound healing, and cancer spreading. However, it is well known that migrating epithelial collectives frequently undergo jamming, stay trapped some period of time, and then start migration again. Consequently, only a part of epithelial cells actively contributes to the tissue development. In contrast to epithelial cells, migrating mesenchymal collectives successfully avoid the jamming. It has been confirmed that the epithelial unjamming cannot be treated as the epithelial-to-mesenchymal transition. Some other mechanism is responsible for the epithelial jamming/unjamming. Despite extensive research devoted to study the cell jamming/unjamming, we still do not understand the origin of this phenomenon. The origin is connected to physical factors such as: the cell compressive residual stress accumulation and surface characteristics of migrating (unjamming) and resting (jamming) epithelial clusters which depend primarily on the strength of cell-cell adhesion contacts and cell contractility. The main goal of this theoretical consideration is to clarify these cause-consequence relations.Comment: 18 pages, 4 figure

Supply Chain RFID Solution Evaluation Applying AHP and FAHP Methods: A Case Study of the Serbian Market

There has been a recent years tendency for replacing traditional supply chain data identifying and collecting systems with RFID (Radio Frequency Identification) technologies. There are different RFID solutions on the market and it is crucial to choose the solution that best suits the set of goals and desired scenarios. The choice of solution depends on a whole range of different factors and criteria. The present paper develops multi-criteria evaluation models based on the AHP (Analytic Hierarchy Process) and FAHP (Fuzzy Analytic Hierarchy Process) approach. There are no papers in the literature that solve the mentioned problem in this way, on a real example. Three RFID solutions are defined referring to different data identification levels in supply chains, namely: product level, level of packaging and the level of the pallet. Solutions are evaluated, and rated in relation to four criteria: investments, costs, participants\u27 visibility and participants\u27 privacy protection in supply chains. Developed models are tested and applied via a case study conducted in the Serbian market. The model is an excellent basis for decision-making in practice and for researchers in the literature, while with certain modifications, it can be used for other similar problems

Mehanizovani postupci pripreme i obrade komposta od rezidbenih ostataka voćarsko-vinogradarske proizvodnje

This paper is part of research about the effects of mechanized process of fragmentation of pruning residues on the composting process. Compost, as a form of organic fertilizer, requires specific production treatment depending on the form of biomass. Pruning residues from fruit-vine production can be translated into quality organic fertilizer, but it is necessary to coordinate mechanized treatment of biomass and technology of composting process with microbiological processes for organic matter decomposition.Rad predstavlja deo istraživanja uticaja mehanizovanih procesa usitnjavanja rezidbenih ostataka na proces kompostiranja. Kompost kao vid organskog đubriva zahteva specifičan tretman proizvodnje u zavisnosti od vida biomase. Rezidbeni ostaci iz voćarsko-vinogradarske proizvodnje se mogu prevesti u kvalitetno organsko đubrivo, ali je potrebno uskladiti mehanizovane procese obrade biomase i tehnologiju kompostiranja sa mikrobiološkim procesima razlaganja organske materije

IL28B Genetic Variations in Patients with Recurrent Herpes Simplex Keratitis

Background and objectives: Recurrent herpes simplex keratitis (HSK) is the most common cause of corneal blindness in the developed world. A relationship between host gene polymorphisms and the recurrence of herpes simplex virus (HSV) infection has previously been proposed. Thus, the aim of this study was to investigate a potential association between the IL28B host genotype and recurrent HSK. Materials and Methods: Eighty patients older than 18 years of age of both genders with a history of recurrent herpes simplex labialis (HSL) were considered for inclusion. Seventy-five of these patients were found to be seropositive for HSV-1 and were subsequently enrolled in the study. Twenty-four of the enrolled patients also had a history of recurrent HSK associated with severe corneal scarring and visual acuity deterioration. Total DNA was isolated from whole blood samples. A single-nucleotide polymorphism (SNP) rs12979860 near the IL28B gene on chromosome 19 was genotyped. Results: A significant association was observed between recurrent HSK and two SNPs of the IL28B genotype (CCrs12979860 and CTrs12979860, p < 0.01). The variation CCrs12979860 showed a significantly greater association with HSK (16 out of 26 patients) compared with CTrs12979860 (8 out of 34 patients). Conclusion: Seropositive individuals with a history of recurrent HSK are likely to have the CC IL28B genotype. This genotype may be related to incomplete control of the infection and more frequent periodical viral shedding along the first nerve branch of the trigeminal ganglion, which clinically manifests as recurrent herpes keratitis. The clinical manifestation of recurrent HSV-1 infection seems to be influenced by polymorphism of the IL28B genotype

Osnovna obrada zemljišta u višegodišnjim zasadima sa rotacionom ašovom

Basic soil tillage in perennial plantations is still present in agro-ecological conditions of R.Serbia despite the tendency for grassing the inter-row space. The reasons for this include arid climatic conditions, as well as the lack of an irrigation system requiring great investments. Mechanical soil tillage provides some advantages over the procedures of soil grassing. These advantages primarily relate to the rational distribution of moisture in the soil, prevention of the development of harmful rodents, better aeration of soil as well as an effective application of organic fertilizers. The paper presents comparative exploitation surveys in soil tillage with a conventional plough, subsoilers and rotary hoes in perennial plantations. The exploitation testing covered determination of working depth, working speed, pulling resistance, front and rear wheel load, performance and fuel consumption. The results of the survey show that apart of having better tractor static load distribution when it is in aggregate with the rotary hoe, this combination has a potential of lowering the fuel consumption. This aggregate has 17% lower fuel consumption compared to the subsoiler usage and 29% lower consumption compared to the plough usage. The main conclusion is that the performance indicators of the working methods described should be analysed in further research. To-date experience shows that the operation of the rotary hoe compared to the standard plough results in lower intensity of the soli mixing and lower intensity of plant residues incorporation in the soil.Osnovna obrada zemljišta u višegodišnjim zasadima i pored tendencija zatravljivanja međurednog prostora još uvek je prisutna u agroekološkim Republike Srbije. Razlog za to su aridni klimatski uslovi kao i nedostatak tehničkih sistema za navodnjavanje za čije korišćenje su potrebne velike investicije. Mehaničkom obradom zemljišta ostvaruju se određene prednosti u odnosu na postupke zatravljivanja. Te prednosti pre svega se odnose na racionalnim raspolaganjem sa vlagom u zemljištu, sprečavanje razvoja štetnih glodara, bolja aeracija zemljišta, kao i efikasno unošenje organskih đubriva. U radu su prikazana uporedna eksploataciona istraživanja pri obradi zemljišta klasičnim plugom, razrivačem i rotacionim ašovom u višegodišnjim zasadima. Ispitivanjima su obuhvaćeni parametri: dubina obrade, vučni otpor, oterećenje prednjih i zadnjih točkova, brzina kretanja, učinak i potrošnja goriva. Rezultati istraživanja u ovom radu pokazuju da pored bolje statičke raspoređenosti opterećenja traktora u radu agregata traktor - rotacioni ašov u odnosu na obradu oranjem i razrivanjem, značajne su i uštede u potrošnji goriva po jedinici površine. Potrošnja goriva kod obrade rotacionim ašovom je manja za oko 17 % u odnosu na podrivanje i do 29 % u odnosu na oranje klasičnim plugom

Nesreće sa vozačima traktora u javnom saobraćaju na teritoriji Beograda

According to research agricultural tractors have a high risk of causing accidents and injuries of various degrees of participants in public transport. In the period from 2005. to 2010. in public transport in the city of Belgrade, 26 tractor drivers were tragically killed. In the same period, 79 tractor drivers were heavy injured (permanent disability), and 167 tractor drivers suffered minor injuries. Different and dangerous accidents and injuries caused by the tractor drivers, are still a reality in Belgrade, the largest city in Serbia. According to research of author, measures like: basic and special professional training of tractor drivers, professional and technical courses for the safe and proper use of the tractor, and the strict observance of traffic laws and technical regulations are missing.Prema istraživanju, poljoprivredni traktori imaju visok rizik pojave izazivanja nesreća i različitog stepena povređivanja učesnika u javnom saobraćaju. U periodu od 2005. do 2010. godine, u javnom saobraćaju na teritoriji grada Beograda, tragično je nastradalo 26 traktorista. U istom periodu utvrđen je broj od 79 teško povređenih (trajna invalidnost) vozača traktora, kao i 167 lako povređenih osoba. Različite i opasne nesreće i povrede u javnom saobraćaju koje izazivaju vozači traktora, i dalje su realnost na teritoriji Beograda, kao najvećeg grada u Srbiji. Prema istraživanju Autora nedostaju: osnovna i posebno dodatna stručna obuka rukovaoca traktora i mašinama, kao stručno-tehnički kursevi za sigurno i pravilno korišćenje traktora, i strogo poštovanje zakonskih saobraćajno-tehničkih regulativa

Mogućnost primene laserskog sistema upravljanja radnim procesom univerzalnog skreperskog ravnjača

Agricultural areas are often uneven, which creates big problems for growing crops. With Universal scraper (machine is a result of project: "Development of modern agricultural machinery and tools for new technologies in plant production TR- 6926" which was funded by the Ministry of Science and Technological Development of Serbia) technical problem with surface of the agricultural plots is solved. The alignment of land routes for the movement of mobile irrigation units is solved to. Significantly improve the performance of these machines would be achieved by using laser management system for managing workflow. This would significantly increase the accuracy of working operations with reduce the duration of the cycle and the energy needs of machine. Laser control systems for agricultural machines significantly affect their performance, significantly raising the precision and speed of execution of operations. Application of these systems is more tightly restricted specificity of working processes in which the most justified the appropriateness of their application, primarily because of cost systems based on the use of laser technology.Poljoprivredne površine su često nepravilnih mikro topografskih karakteristika (neravnine makro i mikro veličina), što stvara velike probleme u tehnologiji gajenja poljoprivrednih kultura. Univerzalni skreperski ravnjač (mašina je rezultat istraživanja u okviru projekta-TR 6926, koji je finansiralo Ministarstvo za nauku i tehnološki razvoj Republike Srbije, [4] ) rešava tehnički problem uređenja mikro i makro neravnina poljoprivrednih zemljišta po površini na parcelama. Pored ovog, može se upotrebiti za ravnanje zemljišnih puteva na poljoprivrednim imanjima za kretanje mobilnih agregata, i formiranje i uređenje zemljanih traka za kretanje mobilnih sistema za navodnjavanje. Znatno poboljšanje radnih karakteristika skreperskog ravnjača postiglo bi se upotrebom nekog od postojećih laserskih sistema za upravljanje radnim procesom. Na ovaj način bi se znatno povećala preciznost rada radnog organa (daske) kod izvršavanja radnih operacija ravnanja poljoprivrednih ili drugih površina, i smanjilo vreme trajanja radnog ciklusa kao i energetskih zahteva mašine. Laserski sistemi upravljanja na poljoprivrednim mašinama bitno utiču na njihove radne karakteristike, znatno podižu preciznost i brzinu izvođenja radnih operacija (dubina rada, širina zahvata) . Primena ovih sistema je još usko ograničena specifičnošću radnih procesa kod kojih je opravdana njihova primena, prvenstveno zbog značajne cene kontrolno – upravljačkih sistema zasnovanih na upotrebi tehnologije lasera

Efekti mehanizovanog načina aplikacije tečnog startnog đubriva u proizvodnji kukuruza

Conventional corn production assumes usage of standard inorganic fertilizers which can be added to the soil by different methods. Unlike conventional production, this research was conducted with assumption that by using different application rates of basic and liquid starter fertilizers, as well as, with improved method of their application, higher yield values and lower moisture content of harvested kernels would be realized. This paper explored influence of mechanized application with different rates and ways of broadcasting basic and liquid starter fertilizer to the soil for corn production. Liquid starter fertilizers were applied concurrently with plantation in two ways: in lanes and spots individually for each plant. The results obtained show that kernel yield was higher in areas where starter fertilizer application was performed for 1.79 t•ha-1, while kernel moisture contents was 3.6% lower compared to results obtained over control surfaces.Konvencionalna proizvodnja kukuruza podrazumeva upotrebu standardnih mineralnih hraniva koja se u zemljiše mogu uneti na različite načine. Za razliku od konvencionalne proizvodnje, ova istraživanja su sprovedena uz predpostavku da će se primenom različitih normi osnovnih i tečnih startnih đubriva kao i unapređenim načinom njihove aplikacije ostvariti veće vrednosti prinosa i niži sadržaj vlage ubranog zrna. U radu je istraživan uticaj mehanizovane aplikacije različitih normi i načina unošenja osnovnog i tečnog startnog đubriva u zemljište pri proizvodnji merkantilnog kukuruza. Aplikacija tečnih startnih đubriva vršena je istovremeno sa setvom i to na dva načina: u trake i tačke pojedinačno za svaku biljku. Dobijeni rezultati pokazuju da je prinos zrna na površinama gde je vršena aplikacija startnog đubriva viši za 1,79 t•ha-1, dok je sadržaj vlažnosti zrna niži za 3,6% u odnosu na rezultate dobijene na kontrolnoj površini