Analysis of factors associated with the occurrence of complications and/or death in patients with acute pancreatitis

Akutni pankreatitis je zapaljenska bolest pankreasa povezana sa komplikacijama i visokom stopom smrtnosti u slučaju ispoljavanja teških oblika bolesti. Cilj ove studije je bio da ispita faktore za koje postoje oprečni literaturni podaci o povezanosti sa nastankom komplikacija i povećanom smrtnošću kod pacijenata sa akutnim pankreatitisom, kao i one koji prethodo nisu dovoljno ispitivani. Metodologija: Sprovedena je retrospektivna kohortna studija sa usađenim studijama tipa slučaj/kontrola, kojom su obuhvaćeni svi pacijenti lečeni zbog akutnog pankreatitisa u Kliničkom centru Kragujevac, Srbija, tokom trogodišnjeg perioda (od oktobra 2011. do decembra 2014. godine). Slučajevi su bili pacijenti koji su imali neku od komplikacija ili koji su umrli, dok su kontrolnu grupu činili pacijenti kod kojih nije zabeležena neka od komplikacija ili smrtni ishod. Povezanost između pretpostavljenih faktora rizika i opserviranog ishoda ispitivana je pomoću univarijante i multivarijantne logističke regresione analize, a rezultati su prikazani vrednostima sirovog i korigovanog unakrsnog odnosa šansi (OR) sa pripadajućim 95% intervalom poverenja (CI). Rezultati: Značajna povezanost sa smrtnim ishodom kod akutnog pankreatitisa je nađena za težinu akutnog pankreatitisa, stariju životnu dob pacijenata, vrednost SOFA skora na prijemu, primenu infuzionih rastvora, primenu albumina, primenu mehaničke ventilacije, enteralnu ishranu putem NGS, nastanak sistemskih komplikacija i insuficijencije organa. Značajna povezanost sa nastankom nekroze kod akutnog pankreatitisa je nađena za stepen težine akutnog pankreatitisa, vrednost CRP-a na prijemu, prisustvo SIRS-a na prijemu, i insuficijencije organa. Značajna povezanost sa nastankom pseudociste kod akutnog pankreatitisa je nađena za vrednosti PCT-a i ukupnih proteina na prijemu, vrednost CT Balthasar skora na prijemu, dužinu primene NSAIL-a, primenu nekih od invazivnih terapijskih postupaka, i vrednost IL-10 trećeg dana bolesti. Zaključak: Faktori rizika povezani sa nastankom komplikacija i smrtnog ishoda kod akutnog pankreatitisa mogu biti: pojava sistemskih komplikacija, insuficijencija organa, prisustvo komorbiditeta, vrednost SOFA skora, prisustvo SIRS-a, vrednosti IL-6, IL-8, IL-10 prvog i trećeg dana bolesti, primena opioidnih analgetika, primena albumina, vrednost glikemije na prijemu, dijabetes melitus, enteralna ishrana putem NGS, vrednost CRP-a na prijemu, pleuralni izliv na prijemu, primena mehaničke ventilacije, vrednosti PCT i ukupnih proteina na prijemu, CT Balthasar skor, dužina primene NSAIL-a, primena nekih od invazivnih terapijskih postupaka. Primena kristaloidnih rastvora može delovati protektivno tako što osam puta smanjuje rizik za nastanak smrtnog ishoda u odnosu na pacijente kojima su tokom lečenja ordinirani i kristaloidni i koloidni rastvori. I dalje smo daleko od kompletnog razumevanja imunskog i inflamatornog odgovora kod akutnog pankreatitisa, pa su zato neophodne studije koje će se u daljim istraživanjima fokusirati na uzročnu povezanost i mehanizme dejstva brojnih medijatora. Ova studija se može uzeti u obzir za stvaranje hipoteza za buduća istraživanja, koja će se detaljnije baviti uzrocima nastanka komplikacija i smrtnog ishoda kod akutog pankreatitisa.Acute pancreatitis is an inflammatory condition associated with complications and with significant mortality rate in the case of severe forms of disease. The aim of this study was to investigate putative factors of increased mortality and complications with contradictory prior evidence, and to reveal factors that were insufficiently explored previously. Methods: A retrospective cohort study with nested case/control design included all adult patients treated for acute pancreatitis in Clinical Center of Kragujevac, Serbia, during the 3-year period (from October 2011 to December 2014). The cases were patients with complications or patients who died, while the controls were patients without complications and patients who survived. The associations between putative risk factors and the study outcomes were tested by univariate and multivariate logistic regressions, and expressed as crude and adjusted odds ratios (OR) with corresponding 95% confidence intervals (CI). Results: Significant association with the lethal outcome in acute pancreatitis was found for advanced age, value of SOFA score on admission, use of infusion solutions, use of albumines, use of mechanic ventilation, enteral nutrition by nasogastric tube, sistemic complications and organ failure. Significant association with pancreatic necrosis was found for degree of severity of acute pancreatitis, value of CRP on admission, presense of SIRS on admission, and organ failure. Significant association with pancreatic pseudocyst was found for value of proteins on admission, CT Balthasar score on admission, duration of use of NSAID, use of some of the invasive therapeutic procedures, and the value of IL-10 on the third day of the disease. Conclusion: Risk factors associated with the occurrence of complications and death in patients with acute pancreatitis may include: the occurrence of complications, organ failure, the presence of comorbidity, value of SOFA score, the presence of SIRS, the value of IL-6, IL-8, IL-10 first and third day of diseases, application of opioid analgesics, use of albumin, blood glucose value at the admission, diabetes mellitus, enteral nutrition via the nasogastric tube, the value of CRP at the admission, pleural effusion on admission, application of mechanical ventilation, the value of PCT and total protein at the admission, CT Balthasar score, duration of application of NSAIDs, application of some of the invasive therapeutic procedures. Application of crystalloid solutions may act protective by eight times reduces the risk of death compared to patients who were administered during treatment with crystalloid and colloid solutions. We are still far away from a complete understanding of the immune and inflammatory response in acute pancreatitis, which is why the necessary studies will be further research focus on causal connections and mechanisms of action of numerous mediators. This studies can be taken into consideration to create a hypothesis for future research, which will be detailed deal with the causes of complications and death in patients with acute pancreatitis

Analysis of factors associated with the occurrence of complications and/or death in patients with acute pancreatitis

Akutni pankreatitis je zapaljenska bolest pankreasa povezana sa komplikacijama i visokom stopom smrtnosti u slučaju ispoljavanja teških oblika bolesti. Cilj ove studije je bio da ispita faktore za koje postoje oprečni literaturni podaci o povezanosti sa nastankom komplikacija i povećanom smrtnošću kod pacijenata sa akutnim pankreatitisom, kao i one koji prethodo nisu dovoljno ispitivani. Metodologija: Sprovedena je retrospektivna kohortna studija sa usađenim studijama tipa slučaj/kontrola, kojom su obuhvaćeni svi pacijenti lečeni zbog akutnog pankreatitisa u Kliničkom centru Kragujevac, Srbija, tokom trogodišnjeg perioda (od oktobra 2011. do decembra 2014. godine). Slučajevi su bili pacijenti koji su imali neku od komplikacija ili koji su umrli, dok su kontrolnu grupu činili pacijenti kod kojih nije zabeležena neka od komplikacija ili smrtni ishod. Povezanost između pretpostavljenih faktora rizika i opserviranog ishoda ispitivana je pomoću univarijante i multivarijantne logističke regresione analize, a rezultati su prikazani vrednostima sirovog i korigovanog unakrsnog odnosa šansi (OR) sa pripadajućim 95% intervalom poverenja (CI). Rezultati: Značajna povezanost sa smrtnim ishodom kod akutnog pankreatitisa je nađena za težinu akutnog pankreatitisa, stariju životnu dob pacijenata, vrednost SOFA skora na prijemu, primenu infuzionih rastvora, primenu albumina, primenu mehaničke ventilacije, enteralnu ishranu putem NGS, nastanak sistemskih komplikacija i insuficijencije organa. Značajna povezanost sa nastankom nekroze kod akutnog pankreatitisa je nađena za stepen težine akutnog pankreatitisa, vrednost CRP-a na prijemu, prisustvo SIRS-a na prijemu, i insuficijencije organa. Značajna povezanost sa nastankom pseudociste kod akutnog pankreatitisa je nađena za vrednosti PCT-a i ukupnih proteina na prijemu, vrednost CT Balthasar skora na prijemu, dužinu primene NSAIL-a, primenu nekih od invazivnih terapijskih postupaka, i vrednost IL-10 trećeg dana bolesti. Zaključak: Faktori rizika povezani sa nastankom komplikacija i smrtnog ishoda kod akutnog pankreatitisa mogu biti: pojava sistemskih komplikacija, insuficijencija organa, prisustvo komorbiditeta, vrednost SOFA skora, prisustvo SIRS-a, vrednosti IL-6, IL-8, IL-10 prvog i trećeg dana bolesti, primena opioidnih analgetika, primena albumina, vrednost glikemije na prijemu, dijabetes melitus, enteralna ishrana putem NGS, vrednost CRP-a na prijemu, pleuralni izliv na prijemu, primena mehaničke ventilacije, vrednosti PCT i ukupnih proteina na prijemu, CT Balthasar skor, dužina primene NSAIL-a, primena nekih od invazivnih terapijskih postupaka. Primena kristaloidnih rastvora može delovati protektivno tako što osam puta smanjuje rizik za nastanak smrtnog ishoda u odnosu na pacijente kojima su tokom lečenja ordinirani i kristaloidni i koloidni rastvori. I dalje smo daleko od kompletnog razumevanja imunskog i inflamatornog odgovora kod akutnog pankreatitisa, pa su zato neophodne studije koje će se u daljim istraživanjima fokusirati na uzročnu povezanost i mehanizme dejstva brojnih medijatora. Ova studija se može uzeti u obzir za stvaranje hipoteza za buduća istraživanja, koja će se detaljnije baviti uzrocima nastanka komplikacija i smrtnog ishoda kod akutog pankreatitisa.Acute pancreatitis is an inflammatory condition associated with complications and with significant mortality rate in the case of severe forms of disease. The aim of this study was to investigate putative factors of increased mortality and complications with contradictory prior evidence, and to reveal factors that were insufficiently explored previously. Methods: A retrospective cohort study with nested case/control design included all adult patients treated for acute pancreatitis in Clinical Center of Kragujevac, Serbia, during the 3-year period (from October 2011 to December 2014). The cases were patients with complications or patients who died, while the controls were patients without complications and patients who survived. The associations between putative risk factors and the study outcomes were tested by univariate and multivariate logistic regressions, and expressed as crude and adjusted odds ratios (OR) with corresponding 95% confidence intervals (CI). Results: Significant association with the lethal outcome in acute pancreatitis was found for advanced age, value of SOFA score on admission, use of infusion solutions, use of albumines, use of mechanic ventilation, enteral nutrition by nasogastric tube, sistemic complications and organ failure. Significant association with pancreatic necrosis was found for degree of severity of acute pancreatitis, value of CRP on admission, presense of SIRS on admission, and organ failure. Significant association with pancreatic pseudocyst was found for value of proteins on admission, CT Balthasar score on admission, duration of use of NSAID, use of some of the invasive therapeutic procedures, and the value of IL-10 on the third day of the disease. Conclusion: Risk factors associated with the occurrence of complications and death in patients with acute pancreatitis may include: the occurrence of complications, organ failure, the presence of comorbidity, value of SOFA score, the presence of SIRS, the value of IL-6, IL-8, IL-10 first and third day of diseases, application of opioid analgesics, use of albumin, blood glucose value at the admission, diabetes mellitus, enteral nutrition via the nasogastric tube, the value of CRP at the admission, pleural effusion on admission, application of mechanical ventilation, the value of PCT and total protein at the admission, CT Balthasar score, duration of application of NSAIDs, application of some of the invasive therapeutic procedures. Application of crystalloid solutions may act protective by eight times reduces the risk of death compared to patients who were administered during treatment with crystalloid and colloid solutions. We are still far away from a complete understanding of the immune and inflammatory response in acute pancreatitis, which is why the necessary studies will be further research focus on causal connections and mechanisms of action of numerous mediators. This studies can be taken into consideration to create a hypothesis for future research, which will be detailed deal with the causes of complications and death in patients with acute pancreatitis

Small and Medium Towns of Central Serbia - Standpoints and Assumptions on Development Perspectives

The role of lower‐order urban centres in national and regional development constitutes an important subject of debate. In the field of contemporary urban research, small and medium‐sized towns are gaining importance because they build a very important link between big cities and rural areas. Obviously, “small” and “medium” generally refers to the size in terms of population of the towns. However, these are highly subjective qualifications, whose concrete meaning depends on the considered national urban system. As the official statistics in Serbia does not recognise categorisation of urban settlements on small, medium or big, for the purposes of analyses presented in this Monograph we have adopted the conditional categorisation of urban settlements in Central Serbia, which corresponds to categorisation applied in some previous research on small and medium‐sized towns of the post‐World War II Serbia. Attention was paid to development of these settlements in Central Serbia in the two periods: 1948‐1981 and 1981‐2002, since they are marked by different socio‐economic aspects of urbanisation. A body of work in this Monograph treats demographic and economic changes which featured Serbian urban settlements of different categories especially in the period 1948‐1981 (primary urbanisation process) when rural‐to‐urban migrations were mostly expressed, and when small towns in particular were the first “dam” for rural emigrants flows. Although it may seam at first glance that the urban settlements’ distribution in the settlement network of Central Serbia has been satisfactory, the discord between the number of inhabitants in Belgrade as the capital city and other urban settlements points to the issue of sharp division between the centre and the periphery. Small and medium‐sized towns of Central Serbia marked a noticeable population growth in the period of the primary urbanisation, but most of all they had the fastest rate of GNP growth and very high employment rates. However, starting with the economic downturn of the country in the 1990s, when a significant concentration of political and economic power happened in Belgrade, many of these settlements have gone through stagnation. It has to be stressed that as in other countries, a number of smaller and particularly medium‐sized towns of Central Serbia have strong roots in the secondary sector which has particularly suffered because of present global and national economy conditions. In such context the question is why do we take an interest in small and medium‐sized towns now or why at all? Firstly, the renewed interest in these urban settlements in Serbia as in other European countries is that, despite being neglected in the past, they are perceived to play quite different roles along the continuum from centre to periphery. With this in view, it is important to clarify the diversity of roles that small and medium sized towns have in relation to their surroundings. Many of them may seem insignificant at a European or even at a national level, whereas at regional and local level they may be of reasonably large importance, like centres in more remote, rural, mountain and peripheral areas. The role might differ regarding the geographical context of a town (being linked with a big city, or part of a functional cluster of small and medium‐sized towns, or the only urban settlement in a region); the economic performance; the function and size of the town; or other aspects, e.g. accessibility or specialisation in certain sector of activity. The knowledge of the role of small and medium‐sized towns needs to be explored to a much larger degree in order to formulate adequate policy recommendations – both at EU and national level, which on one hand can support existing positive development and on the other hand can assist small and medium‐sized towns in decline in diverting present negative development trends. Small and medium‐sized towns of Central Serbia have a potential to become sustainable, but only if urban networks are developed between these smaller urbanities and also among them and bigger cities. In other words, a key factor for the future existence and development of these towns is cooperation and new and more efficient types of governance and urban policy. This work aims to offer an incentive for further research on small and medium-sized towns in our country by provision of fundamental theses requiring more thorough investigation in particular contexts.IAUS Monograph No. 55, November 2007

DATA ANALYSIS OF ENVIRONMENTAL CONDITIONS INFLUENCING THE WORK OF LABORATORY EQUIPMENT AND APPLICATION OF MACHINE LEARNING MODELS FOR CLASSIFICATION OF POOR CONDITIONS

Environmental conditions can have a crucial impact on the functioning of laboratory equipment. Electric components are sensitive to the influence of certain environmental factors such as temperature, humidity, vibrations, etc. Environmental factors should, therefore, be monitored to avoid their negative influence on the system and potential faults and failures they could cause. Unlike the traditional approaches which required the presence of special staff to monitor environmental factors and react if they are poor, the rise of the Internet of Things enhanced the application of intelligent solutions where human factor is not necessary. In this paper, research on data analysis, preprocessing and intelligent classification of environmental conditions has been conducted. The data was collected by sensors connected to Raspberry Pi. The applied monitoring system setup enabled long-distance monitoring of laboratory conditions through the internet and full applicability of fundamental IoT concepts. Since data preparation is an important step in the process of designing machine learning models, the collected data was analyzed and preprocessed in Python. Intelligent classification of environmental conditions was performed using machine learning models k-Nearest Neighbors and Random Forest. Grid search was used for model selection, and the performances of k-Nearest Neighbors and Random Forest machine learning models were compared. Experimental results show that these machine learning models can be successfully used for intelligent classification of environmental conditions

Small and Medium Towns of Central Serbia - Standpoints and Assumptions on Development Perspectives

The role of lower‐order urban centres in national and regional development constitutes an important subject of debate. In the field of contemporary urban research, small and medium‐sized towns are gaining importance because they build a very important link between big cities and rural areas. Obviously, “small” and “medium” generally refers to the size in terms of population of the towns. However, these are highly subjective qualifications, whose concrete meaning depends on the considered national urban system. As the official statistics in Serbia does not recognise categorisation of urban settlements on small, medium or big, for the purposes of analyses presented in this Monograph we have adopted the conditional categorisation of urban settlements in Central Serbia, which corresponds to categorisation applied in some previous research on small and medium‐sized towns of the post‐World War II Serbia. Attention was paid to development of these settlements in Central Serbia in the two periods: 1948‐1981 and 1981‐2002, since they are marked by different socio‐economic aspects of urbanisation. A body of work in this Monograph treats demographic and economic changes which featured Serbian urban settlements of different categories especially in the period 1948‐1981 (primary urbanisation process) when rural‐to‐urban migrations were mostly expressed, and when small towns in particular were the first “dam” for rural emigrants flows. Although it may seam at first glance that the urban settlements’ distribution in the settlement network of Central Serbia has been satisfactory, the discord between the number of inhabitants in Belgrade as the capital city and other urban settlements points to the issue of sharp division between the centre and the periphery. Small and medium‐sized towns of Central Serbia marked a noticeable population growth in the period of the primary urbanisation, but most of all they had the fastest rate of GNP growth and very high employment rates. However, starting with the economic downturn of the country in the 1990s, when a significant concentration of political and economic power happened in Belgrade, many of these settlements have gone through stagnation. It has to be stressed that as in other countries, a number of smaller and particularly medium‐sized towns of Central Serbia have strong roots in the secondary sector which has particularly suffered because of present global and national economy conditions. In such context the question is why do we take an interest in small and medium‐sized towns now or why at all? Firstly, the renewed interest in these urban settlements in Serbia as in other European countries is that, despite being neglected in the past, they are perceived to play quite different roles along the continuum from centre to periphery. With this in view, it is important to clarify the diversity of roles that small and medium sized towns have in relation to their surroundings. Many of them may seem insignificant at a European or even at a national level, whereas at regional and local level they may be of reasonably large importance, like centres in more remote, rural, mountain and peripheral areas. The role might differ regarding the geographical context of a town (being linked with a big city, or part of a functional cluster of small and medium‐sized towns, or the only urban settlement in a region); the economic performance; the function and size of the town; or other aspects, e.g. accessibility or specialisation in certain sector of activity. The knowledge of the role of small and medium‐sized towns needs to be explored to a much larger degree in order to formulate adequate policy recommendations – both at EU and national level, which on one hand can support existing positive development and on the other hand can assist small and medium‐sized towns in decline in diverting present negative development trends. Small and medium‐sized towns of Central Serbia have a potential to become sustainable, but only if urban networks are developed between these smaller urbanities and also among them and bigger cities. In other words, a key factor for the future existence and development of these towns is cooperation and new and more efficient types of governance and urban policy. This work aims to offer an incentive for further research on small and medium-sized towns in our country by provision of fundamental theses requiring more thorough investigation in particular contexts.IAUS Monograph No. 55, November 2007

Combined lymphangioma and hemangioma of the spleen in a patient with Klippel–Trénaunay syndrome

Introduction. Klippel–Trénaunay syndrome (KTS) is a very rare congenital anomaly of blood vessels, characterized by the following clinical triad: varicose superficial veins, port-wine stain and usually bony and soft tissue hypertophy of extremities, most often located in the lower extremities. It is often accompanied by visceral manifestations, and rarely combined with splenomegaly. Case Outline. A 30-year-old female patient came to the Surgery Clinic because of occasional left hypochondrial pain. After she was diagnosed with KTS combined with splenomegaly, splenectomy was performed. Macroscopic and microscopic spleen examination indicated the presence of tumor of vascular origin, presenting a combination of lymphangioma and hemangioma. Conclusion. Diagnosed KTS demands a thorough clinical examination of the patient because of the potential presence of visceral manifestations. When splenomegaly is present, even though being often benign, splenectomy is usually performed to alleviate accompanying symptoms which occur as a result of organ enlargement and compression, to prevent rupture and consequential bleeding when the vascular spleen tumor is large, and finally to avoid a possibility of malignant transformation

Uspostavljanje programa selektivnog uzgoja kalifornijske pastrmke (oncorhynchus mykiss, walbaum) u Srbiji

Zahtev za sve većim količinama hrane za ljudsku upotrebu, efikasnost iskorišćavanja hraniva i prostora za gajenje domaćih životinja, kao i pojava mnogih bolesti doveli su do intenzivnog razvijanja selekcionih programa u svim granama poljoprivrede. Za razliku od ostalih gajenih životinja, programi selekcije u akvakulturi su se razvili nešto kasnije usled nedostatka potrebnih procena heritabilnosti, koeficijenata varijacija i korelacija za ekonomski bitne osobine. Trenutno se u akvakulturi samo 1-2% od ukupne proizvodnje zasniva na genetički unapređenim vrstama riba (Gjedrem, 1997). Korišćenjem selektovanih linija riba postiže se više korisnih stvari. Na prvom mestu, programi selekcije riba predstavljaju jedini način stalnog unapređenja ekonomski bitnih osobina kao sto su prirast, konverzija hrane, otpornost na bolesti, smanjenje masnoće u mesu riba. Ribe iz selektovanih linija efikasnije iskorišćavaju hraniva i na taj način smanjuju pritisak na divlje populacije riba koje se koriste za proizvodnju ribljeg brašna, kao glavnog izvora proteina u smešama za ishranu pastrmki. Ribe koje potiču iz divljine ne napreduju zadovoljavajućim brzinom, što znači da su konstantno pod stresom, za razliku od riba poreklom iz selekcionih programa koje pokazuju manji uticaj stresa usled gajenja u zarobljeništvu. Tako se na ovaj način korišćenjem selektovanih linija riba postiže efikasna i održiva proizvodnja uz vođenje računa o dobrobiti životinja. Drugi dobar razlog za uspostavljanje programa selekcije pastrmke u Srbiji je dobro dokumentovano postojanje interakcije genotip x okolina kod kalifornijske pastrmke, kao što su pokazala istraživanja (McKay et al., 1984; Hanke et al., 1989; Sylven et al., 1991; Winkelman and Peterson, 1994; Kettunen et al., 1999; Kause et al., 2003). Na kraju, ali ne i najmanje važna je i kontrola bolesti kod kalifornijske pastrmke i mogućnost stvaranja otpornih linija pastrmki na neke bolesti putem selektivnog uzgoja (Henrion, 2005). Jedno od rešenja za ovaj ozbiljan problem, pored boljeg sistema kontrole pastrmske ikre poreklom iz uvoza, je i stvaranje lokalnih selektovanih matičnih jata sa proverenim poreklom i povećenom otpornošću na bolesti. Obzirom da za kalifornijsku pastrmku postoje pouzdani podaci o varijabilnosti i heritabilnosti proizvodnih osobina ovo pruža mogućnost efikasne selekcije, a samom tim i značajnog unapređenja proizvodnje uz smanjen ukupni mortalitet, putem odgovarajućeg programa selekcije u Srbiji

Fatty acid profile in muscles of carp (cyprinus carpio l.) Raised in a semi-intensive production system fed with grains, pelleted and extruded feed

The effects of grains, pelleted and extruded feed on the fatty acid content in carp meat has not been examined yet. In this work, we present evidence that the high carbohydrate content in all three types of feed causes oleic acid to predominate in all meat samples. A higher PUPA content in the meat of fish fed with granulated feed was detected. The extruded feed diet led to 69% greater n-3, and 53% lower n-6 fatty acid contents. Their ratio is thus 2.64-fold higher than in meat of carp fed with pelleted feed. A higher content of n-3 fatty acids in fish fed with extruded feed was the consequence of higher DNA (1.6 times) and EPA (3.3 times) contents. The detected differences could be the consequence of the thermal treatment of extruded feed that makes the proteins, carbohydrates and lipids more accessible to fish than in a pelleted feed

Uloga i značaj zooplanktona u poluintenzivnom sistemu gajenja šarana

Jedan od svetski najzastupljenijih sistema za gajenje riba je poluintenzivni sistem koji čini više od 80% (Tacon and De Silva, 1997). U najtradicionalnijem obliku, prisutnom uglavnom u Aziji, veći deo nutritivnih potreba riba se zadovoljava iz prirodne hrane, prisutne u jezeru, dok se manji deo zadovoljava kroz dodatnu hranu. Osnovna ideja ovog sistema je da se potrebe riba u proteinima zadovoljavaju konzumiranjem zooplanktona, zoobentosa i druge prirodne hrane, dok se energetske potrebe zadovoljavaju žitaricama i drugim lokalnim proizvodima u obliku dodatne hrane. Poslednjih godina u zemljama jugoistočne Evrope (Srbiji, BiH, Bugarskoj, Rumuniji) sve se više koristi peletirana i ekstrudirana hrana, umesto žitarica ili u kombinaciji sa žitaricama uz iskorišćavanje prirodne hrane iz samog ribnjaka. Zooplankton predstavlja važanu prirodnu hranu za larve i odrasle stadijume mnogih vrsta riba koje se gaje u akvakulturi. On je i glavna prirodna hrana za larve i mesečnjake šarana, a zajedno sa faunom dna, predstavlja hranu za mlađ i gajenog konzumnog šarana. Zooplankton je značajan izvor proteina, amino kiselina, lipida, masnih kisenina, minerala i enzima (Kibria et al., 1997). U novim ribnjacima zooplankton je uglavnom poreklom iz vode za vodosnabdevanje, dok u starijim objektima, deo ovih organizama potiče iz banke trajnih jaja koja se nalaze u sedimentu, najčešće do dubine od 2 do 10 cm, odakle se jedan deo svake sezone razvija i prelazi u vodu. Razvitak zooplanktonskih organizama (Rotatoria, Cladocera, Copepoda), ima izraženu sezonalnost, pa je maksimum produkcije karakterističan za maj i jun (Paterson, 1993). Na žalost, tokom letnjih meseci (jul i avgust), kada postoje optimalni temperaturni uslovi za rast šarana, najčešće se javlja značajan pad uglavnom svih grupa zooplanktona a naročito kladocera i kopepoda. Ovaj pad u produktivnosti je pre svega rezultat sezonalnosti zooplanktonskih organizama a može biti i posledica velikog pritiska riba na zooplankton u uslovim gustog nasada riba. Do izvesne mere se produkcija prirodne hrane može podstaći upotrebom veštačkih đubriva ili stajnjaka, koji zapravo dovode do porasta produkcije fitoplanktona koji je osnov ishrane za zooplanktonske organizme. Larve šarana mogu da konzumiraju manje oblike zooplanktona kao što su rotatorije i nauplius larve kopepoda. Sa porastom, šaran počinje da konzumira krupnije oblike kladocera i kopepoda, a potom i organizme faune dna, hironomide i oligohete. Za šarana i druge vrste Teleostea, krupniji oblici zooplanktona, naročito krupne kladocere (Daphni magna i D. pulex) predstavljaju lako uočljiv plen, ne samo zbog dimenzija tela, već i zbog dobro pigmentisanog i krupnog oka. Osim toga, starije uzrasne kategorije šarana imaju tako razvijeni usni aparat koji je prilagođen za sakupljanje hrane koja je veća od 250 μm (Sibbing et al., 1986). Usled ovoga, na početku proizvodne sezone, na većini ribnjaka nasađenih sa jedno- i dvogodišnjom mlađi, vrlo brzo dolazi do istrebljenja krupnih zooplanktonskih organizama, što dovodi do dominacije rotatorija, larvi kopepoda kao i malih kladocera, kao što je Bosmina longirostris, jer više nema kompeticije za hranom. U slučajevima kada postoji niska produkcija prirodne hrane, a ne postoji mogućnost đubrenja, usled npr. visoke temperature vode, dodatni objekti kao što su neupotrebljiva ribnjačka jezera, jame ili pak veliki tankovi, mogu poslužiti za dodatnu produkciju prirodne hrane – zooplanktonskih organizama. Masovna proizvodnja prirodne hrane na ovaj način može biti relativno jeftina posebno kada se kao đubrivo koristi stajnjak. Za manje količine zooplanktona, sakupljanje se može obaviti pomoću velikih planktonskih mreža zakačenih za čamac ili se mogu vući sa obale. Ukoliko su u pitanju veći objekti u kojima se gaji zooplankton, za sakupljanje se može koristiti adaptiran čamac po ugledu na "Baleen sistem" koji je poseduje deo koji zahvata vodu i mrežu za proceđivanje, nakon čega se organizmi propuštaju kroz seriju mrežica čime se raspoređuju po veličinskim klasama. Razmatrajući svetski problem nedostatka vode i potrebe za održivom upotrebom vode i nutrijenata u akvakulturi neophodno je unapređenje dosadašnje prakse poluintenzivnog gajenja šarana. Prirodna hrana predstavlja obnovljiv izvor proteina, amino kiselina, masti i masnih kiselina, za gajene ribe i zato usavršavanje poluinteinzivnog sistema između ostalih mera unapređenja treba da ide i u pravcu njihovog većeg korišćenja bilo iz samih ribnjačkih objekata za gajenje šarana ili iz planktonskih jama, jezera ili tankova za njihovo gajenje. Na ovaj način će se omogućiti ekonomičnije iskorišćavanje prirodne hrane, a u kombinaciji sa optimalnom dodatnom hranom će nutritivne potrebe riba biti u potpunosti zadovoljene