Pesticidi u zemljištu: delovanje na mikroorganizme

Since their discovery to the present day, pesticides have been an inevitable segment of agricultural production and efforts have been made to synthesize compounds that would share a required efficacy along with selectivity, sufficient persistence on the object of protection and favourable toxicological and ecotoxicological characteristics so as to minimize their effect on the environment. When a pesticide gets into soil after application, it takes part in a number of physical, chemical and biological processes that depend not only on the compound itself, but a number of other factors as well, such as: physical, chemical and biological characteristics of soil; climatic factors, equipment used, method of application, method of storage, handling and disposal of waste, site characteristics (proximity of ground and underground waters, biodiversity and sensitivity of the environment). Microorganisms play an important role in pesticide degradation as they are able to utilize the biogenic elements from those compounds, as well as energy for their physiological processes. On the other hand, pesticides are more or less toxic substances that can have adverse effect on populations of microorganisms and prevent their development, reduce their abundance, deplete their taxonomic complexity and create communities with a lower level of diversity and reduced physiological activity. The article discusses complex interactions between pesticides and microorganisms in soil immediately after application and over the ensuing period. Data on changes in the abundance of some systematic and physiological groups of microorganisms, their microbial biomass and enzymatic activity caused under pesticide activity are discussed as indicators of these processes.Od otkrivanja pa do danas, pesticidi su ezaobilazni seg­ment poljoprivredne proizvodnje, a u njihovom razvoju teži se ka sintezi jedinjenja koja će imati potrebnu efikasnost i selektivnost, dovoljnu dužinu zadržavanja na objektu i povoljne toksikološke i ekotoksikološke karakteristike, kako bi imali što manji neželjeni uticaj na životnu sredinu u celini. Kad se nakon primene nađe u zemljištu, pesticidno jedinjenje biva izloženo brojnim fizičkim, hemijskim i biološkim procesima razgradnje koji zavise ne samo od osobina jedinjenja, već i od čitavog niza drugih faktora, kao što su: fizičke, hemijske i biološke karakteristika zemljišta i klimatski faktori. U procesima razgradnje pesticida u zemljištu značajnu ulogu imaju mikroorganizmi, imajući u vidu da su sposobni da iz njihovih molekula koriste biogene elemente i energiju za svoje fiziološke procese. S druge strane, pesticidi koji su sami po sebi manje ili više toksične supstance, mogu štetno da deluju na populacije mikroorganizma i da dovedu do zaustavljanja njihovog razvoja, smanjenja brojnosti, osiromašenja taksonomskog sastava, stvaranja zajednica sa nižim stepenom raznovrsnosti i smanjenom fiziološkom aktivnošću. U ovom radu razmatraju se uzajamni procesi i odnosi koji se uspostavljaju u zemljištu između pesticida i mikroorganizama neposredno, kao i u periodu posle primene. Kao pokazatelji ovih procesa dati su podaci o promeni brojnosti pojedinih sistematskih i fizioloških grupa mikroorganizama, mikrobiološke biomase i aktivnosti enzima koji su nastali pod uticajem pesticida

Delovanje atrazina na mikroorganizme u zemljištu

Effects of the herbicide atrazine on soil microorganisms was investigated. Trials were set up in laboratory, on a clay loam soil. Atrazine was applied at 8.0, 40.0 and 80.0 mg/kg soil rates. The abundance of total microorganisms, fungi, actinomycetes, cellulolytic microorganisms and amino-heterotrophs was recorded. Soil samples were collected 1, 7, 14, 21, 30 and 60 days after atrazine treatment for microbiological analyses. The results showed that the intensity of atrazine effect on soil microorganisms depended on treatment rate, exposure time and group of microorganisms. Atrazine had an inhibiting effect on cellulolytic microorganisms and amino-heterotrophs. Initially, it inhibited fungi and actinomycetes but its effect turned into a stimulating one once a population recovered. Atrazine had a stimulating effect on total abundance of microorganisms.U radu je ispitivano delovanje atrazina na mikroorganizme u zemljištu. Ogled je postavljen u laboratorijskim uslovima na zemljištu tipa glinovita ilovača. Atrazin je primenjen u količinama od 8.0, 40.0 i 80.0 mg/kg zemljišta. Praćen je ukupan broj mikroorganizama, broj gljiva, aktinomiceta, celulolitskih mikroorganizama i aminoheterotrofa. Uzorci za mikrobiološke analize uzimani su 1, 7, 14, 21, 30 i 60 dana posle primene atrazina. Dobijeni rezultati su pokazali da delovanje atrazina na zemljišne mikroorganizme zavisi od primenjene količine, dužine delovanja i vrste mikroorganizama. Atrazin je inhibitorno delovao na celulolitske mikroorganizme i aminoheterotrofe. Na aktinimicete i gljive delovao je prvo inhibitorno, a kasnije, zbog obnavljanja populacija stimulativno. Na ukupan broj mikroorganizama atrazin je delovao stimulativno

Acute onset of tinnitus in patients with sudden deafness

Objective: We made hypotheses that tinnitus will appear more likely in patients with sudden deafness with superior hearing in unaffected ear or with more severe acute hearing loss. Methods: A retrospective cohort study was performed. Five hundred forty-one patients were identified with idiopathic sudden sensorineural hearing loss (ISSHL) from January 1995 to August 2006. The exclusion criteria for this study were as follows: bilateral sudden hearing loss and Meniere disease, previous tinnitus or bilateral tinnitus at initial evaluation, and onset of hearing loss less than 7 days. The cohort enrolled 454 patients. The enrolled patients were classified into two groups: patient with acute onset tinnitus in the affected ear and patients without tinnitus at initial visit. Main outcome measures were patient age, the presence or absence of vertigo and tinnitus, audiometric patterns, the severity of hearing loss, and hearing in the unaffected ear. Results: Better contralateral hearing (n = 220 versus n = 72, P < 0.001) and younger age (48 versus 55 years, P < 0.001) were independently associated with the acute onset of tinnitus in patients with ISSHL. The degree of asymmetry between the ears did not differ significantly between patients with and without tinnitus. The sex, presence of vertigo, shape of audiogram, and severity of hearing loss were not correlated with tinnitus occurrence. Conclusions: Tinnitus triggered by ISSHL was more frequent in patients with better contralateral hearing and of a younger age, irrespective of the severity of hearing loss on the affected side or the asymmetry between the ears

Delovanje metribuzina na aktivnost nekih enzima u zemljištu

Eeffects of metribuzin on the activity of some enzymes in soil was investigated. Trials were set up in the laboratory on a clay loam soil. Metribuzin was applied at 12.0, 24.0 and 60.0 mg/kg soil rates and soil samples were collected 3, 7, 15, 30 and 45 days after metribuzin treatment for analyses. Alkaline phosphatase, acid phosphatase, dehydrogenase, urease and β-glucosidase were recorded. The results showed that the intensity of metribuzin effects on the activity of enzymes depended on treatment rate, exposure time and enzyme group. Metribuzin had an inhibiting effect on acid phosphatese and dehydrogenase, as well as on alkaline phosphatase in the initial stage before it turned into a stimulating one, while metribuzin stimulated urease and had no effect on β-glucosidase.U radu je ispitivano delovanje metribuzina na aktivnost nekih enzima u zemljištu. Ogled je postavljen u laboratorijskim uslovima na zemljištu tipa černozem. Metribuzin je primenjen u količinama 12,0, 24,0 i 60,0 mg/kg zemljišta, a uzorci za analizu uzimani su 3, 7, 15, 30 i 45 dana posle primene metribuzina. Praćena je aktivnost enzima alkalna i kisela fosfataza, dehidrogenaza, ureaza i β-glukozidaza. Dobijeni rezultati su pokazali da delovanje metribuzina na aktivnost enzima zavisi od primenjene količine, dužine delovanja i vrste enzima. Metribuzin je delovao inhibitorno na kiselu fosfatazu i dehidrogenazu, na alkalnu fosfatazu prvo je delovao inhibitorno, a kasnije stimulativno, na ureazu je delovao stimulativno, dok na β-glukozidazu nije delovao

Zajednica Arctio-Artemisetum vulgaris (Tx. 1942) Oberd. et al. 1967.: najzastupljenija ruderalna zajednica na području Pančevačkog rita

A several-year investigation of distribution, phytocoenological differentiation, floristic composition and structure of the ruderal flora and vegetation, and relative anthropogenic influences was conducted in the area of Pančevački rit. The study focused on the ruderal community Arctio-Artemisetum vulgaris, the most widespread of 10 ruderal communities identified in a detailed phytocoenological analysis of the location of Pančevački rit.Na području Pančevačkog rita su obavljena višegodišnja floristička istraživanja rasprostranjenosti, fitocenološke diferenciranosti, strukturalne i antropogene uslovljenosti ruderalne vegetacije. U radu je analizirana zajednica Arctio-Artemisetum vulgaris, koja predstavlja najrasprostranjeniju zajednicu od 10 razvijenih i opisanih ruderalnih zajednica na prostoru Pančevačkog rita

Hematološki efekti herbicida Avalon® (bentazon + dikamba) za pacova

Hematological effects of the herbicide Avalon (GAL-57), a mixture of bentazon and dicamba, were tested on rats. Avalon was administered by gavage at three and four dose levels (250, 500, 1000 and 1250 mg/kg weight/day) for 28 and 90 days. Hematological parameters, number of erythrocytes, leukocytes and platelets, hemoglobin concentration, hematocrit and erythrocyte indexes (MCV, MCH and MCHC) were monitored. The results showed that the herbicide Avalon caused decrease in the values of hemoglobin, hematocrit and erythrocyte indexes (both males and females). The changes (mostly) correlated with the doses administered and, in most cases, a lower susceptibility of females than males was observed. The herbicide GAL-57 had no adverse effect on the number of leukocytes, erythrocytes and thrombocytes (both sexes, all doses tested). The results showed that the herbicide Avalon causes weak anemia to the animals tested. Reversibility was apparent during the recovery period of 28 days.U radu su ispitivani hematološki efekti herbicida Avalon (GAL-57), koji je mešavina bentazona i dikambe kao aktivnih materija, na pacovima. Preparat je doziran oralnim putem (sondom u želudac) u više nivoa doza (250, 500, 1000 i 1250 mg/kg/telesne mase/dan) tokom 28 i 90 dana. Praćeni su sledeći pokazatelji: broj eritrocita, leukocita i trombocita, koncentracija hemoglobina, hematokrit i eritrocitni indeksi (prosečna zapremina eritrocita, srednja vrednost hemoglobina po eritrocitu i prosečna koncentracija hemoglobina u eritrocitima). Rezultati ovih ispitivanja su pokazali da herbicid Avalon kod oba pola izaziva smanjenje vrednosti hemoglobina, hematokrita i eritrocitnih indeksa, dok kod drugih ispitivanih pokazatelja (broj leukocita, eritrocita i trombocita) nisu registrovane promene u odnosu na kontrolu. Sve promene su, najčešće, u korelaciji sa primenjenim dozama a uočena je, u najvećem broju slučajeva, i nešto manja osetljivost ženki u odnosu na mužjake. Rezultati ispitivanja su, takođe, pokazali da Avalon izaziva blagu anemiju kod ispitivanih životinja s tim da je efekat reverzibilnog karaktera; nakon isteka perioda oporavka od 28 dana vrednosti za sve ispitivane parametre se vraćaju na normalu i ne razlikuju se značajnije u odnosu na kontrolu

Rimsulfuron u zemljištu: uticaj na mikrobiološke parametre u različitim tipovima zemljišta

The effects of rimsulfuron a sulfonylurea herbicide on the growth and activity of soil microorganisms under laboratory conditions was investigated in two soils. The application rates were: 0.2, 2.0 and 20.0 mg a.i kg-1 soil. The lowest concentration tested was the label rate (0.2 mg a.i kg-1), and the other two were ten and hundred times higher. No adverse effects on microbiological processes were observed for the label rate. Decrease in microbial biomass carbon, dehydrogenase activity, fungi and bacteria in comparison with untreated control, were found at higher rates. The magnitude of these effects were generally slight and transitory.Na dva tipa zemljišta, u laboratorijskim uslovima, ispitivan je uticaj herbicida rimsulfurona iz grupe sulfonilurea na brojnost i aktivnost zemljišnih mikroorganizama. Rimsulfuron je primenjen u koncentracijama 0,2, 2,0 i 20,0 mg a.s. na kilogram zemljišta. Najmanja ispitivana koncentracija (0,2 mg) odgovarala je količini koja se preporučuje za primenu, a druge dve su deset i sto puta veće od preporučene. Kada je primenjen u preporučenoj količini, rimsulfuron nije imao uticaja na ispitivane mikrobiološke parametre. Smanjenje mikrobiološke biomase ugljenika, dehidrogenazne aktivnosti, brojnosti gljiva i bakterija utvrđene su kod većih koncentracija rimsulfurona. Intenzitet ovih promena je, uglavnom, bio slab i prolaznog karaktera

The need for new approaches to the study of traditional architecture in the process of architectural education

When modernizing the curricula at the Faculty of Architecture of the University of Belgrade, some fields of study have been somewhat neglected, including the teaching of traditional architecture, which is currently studied only at a basic level. Many students complete their education without adequate knowledge in this field, and this has affected the current situation of architectural practice in Serbia. Two optional courses were initiated to try to fill this gap, with different approaches to the study of traditional architecture. One course focuses on the study of traditional building techniques and materials related to the historical building context. The other course explores the correlation between traditional and sustainable architecture, following the idea that the latter is closely connected to traditional architecture. These teaching experiences, their problems and their outcome will be presented in this paper.Al modernizar los planes de estudio de la Facultad de Arquitectura de la Universidad de Belgrado, algunos ámbitos de estudio quedaron bastante desatendidos. Éste es el caso de la enseñanza de la arquitectura tradicional, que actualmente sólo se estudia en el nivel básico. Muchos estudiantes terminan su formación sin tener el conocimiento apropiado de este campo y, en consecuencia, esto afecta a la situación actual del ejercicio de la arquitectura en Serbia. Para tratar de llenar este vacío, se iniciaron dos cursos optativos con diferentes enfoques en el estudio de la arquitectura tradicional. Uno de los cursos se centra en el estudio de las técnicas y los materiales de construcción tradicional en lo referente al contexto histórico de los edificios. El otro explora la correlación entre la arquitectura tradicional y la sostenible, conforme a la idea de que esta última está estrechamente relacionada con la arquitectura tradicional. Se presentan en este documento estas experiencias educativas y sus problemas y resultados