Advanced Aspects of the Galactic Habitability

Context. Astrobiological evolution of the Milky Way (or the shape of its "astrobiological landscape") has emerged as one of the key research topics in recent years. In order to build precise, quantitative models of the Galactic habitability, we need to account for two opposing tendencies of life and intelligence in the most general context: the tendency to spread to all available ecological niches (conventionally dubbed "colonization") and the tendency to succumb to various types of existential catastrophes ("catastrophism"). These evolutionary tendencies have become objects of study in fields such as ecology, macroevolution, risk analysis, and futures studies, while a serious astrobiological treatment has been lacking so far. Aims. Our aim is to numerically investigate the dynamics of opposed processes of expansion (panspermia, colonization) and extinction (catastrophic mechanisms) of life in the Galaxy. Methods. We employ a new type of numerical simulation based on 1D probabilistic cellular automaton with very high temporal resolution, in order to study astrobiological dynamics. Results. While the largest part of the examined parameter space shows very low habitability values, as expected, the remaining part has some observationally appealing features that imply, among other things, a reduction in the amount of fine-tuning necessary for resolving the Fermi paradox. Conclusions. Advanced aspects of Galactic habitability are amenable to precision studies using massive parallel computer simulations. There are regions of parameter space corresponding to a quasi-stationary state satisfying observable constraints and possessing viable SETI targets.Comment: Language corrected version, to appear in Astronomy & astrophysic

Occurence and genetic diversity of Giardia intestinalis, Cryptosporidium spp. and Toxoplazma gondii in surface waters in Serbia

Voda je neophodan resurs za ljudsko društvo, stoga je važno da ona bude i bezbedna za upotrebu. Usled rasta potrebe za vodom, često se pribegava i upotrebi vode koja nije hemijski i bakteriološki ispravna. Predmet ovog istraživanja jesu parazitske protozoe Giardia intestinalis, Cryptosporidium spp. i Toxoplasma gondii i detekcija njihovih životnih oblika u površinskim vodama u Srbiji. Da bi se utvrdilo prisustvo parazita u vodotokovima, kao i stepen kontaminacije, analizirana su vodna tela propisana programom mera Agencije za zaštitu životne sredine koja se nalaze u 19 okruga, uključujući i grad Beograd. Uzorkovanje vode započeto je krajem 2018. godine i trajalo je do jula 2021. godine, i tom prilikom je sakupljeno 48 uzoraka vode iz površinskih voda različite kategorije. Za detekciju (oo)cista G. intestinalis i Cryptosporidium spp. korišćena je metodologija US EPA 1623 dok je detekcija oocista T. gondii vršena PCR metodom uz prethodno koncentrisanje uzorka. Od ukupno 48 uzoraka, u 24 (50%, 24/48) detektovana je barem jedna od tri ispitivane protozoe. Rezultati testa imunofluorescencije (IFA) pokazali su prisustvo cista G. intestinalis u 14 uzoraka (29,2%, 14/48), prisustvo oocista Cryptosporidium spp. u pet (10,4%, 5/48), dok su ciste i oociste oba parazita detektovane u tri uzorka (6,25%, 3/48). PCR metodom amplifikacije β-giardin gena prisustvo gDNK G. intestinalis detektovano je u osam uzoraka (16,6%, 8/48), dok amplifikacija nijednog od četiri gena korišćena u detekciji Cryptosporidium spp. nije bila uspešna. U četiri uzorka (8,3%, 4/48) detektovana je gDNK T. gondii, pri čemu je u detekciji prvo korišćen 529 bp repetitivni fragment, nakon čega su za potvrdu korišćeni geni GRA6 i SAG2. Tipizacija asemblaža G. intestinalis bila je uspešna u tri uzorka. U jednom uzorku detektovana je asemblaža A, dok je u preostala dva uzorka detektovana asemblaža B. Statističkom obradom podataka o hidromorfološkom kvalitetu voda nije se ustanovila povezanost tih parametara i prisustva parazita u vodi. Takođe, korišćenjem qGIS softvera, lokacije na kojima je vršeno uzorkovanje, kao i njihov status u odnosu na detekciju parazita, prikazani su na mapi Republike Srbije. Na osnovu toga zapaženo je veće prisustvo protozoa u vodama u Mačvanskom i Sremskom okrugu u zapadnoj Srbiji, kao i Pomoravskom i Šumadijskom okrugu u centralnoj Srbiji. Rezultati ove doktorske disertacije po prvi put u Srbiji ukazali su na postojanje kontaminacije vodotokova parazitskim protozoama G. intestinalis, Cryptosporidium spp. i T. gondii. Podaci dobijeni ovim istraživanjem mogu se iskoristiti za pravljenje strategije za zaštitu zdravlja ljudi i životinja i sprečavanje hidričnih epidemija, a takođe predstavljaju uvod u dalja, opsežnija istraživanja u ovoj oblasti koja bi pomogla boljem razumevanju kontaminacije i distribucije parazitskih protozoa u površinskim vodama Srbije.Since water is such an important resource for human society, it must be safe to use. Due to the rising demand for water, it is becoming increasingly common to use water that is neither chemically nor bacteriologically suitable. This research focused on the parasitic protozoa Giardia intestinalis, Cryptosporidium spp. and Toxoplasma gondii, and the detection of their life forms in surface waters in Serbia. Water bodies designated as economically or strategically significant for the country by the Serbian Environmental Protection Agency, in 19 administrative districts, were analysed to determine the occurrence of parasites as well as the degree of contamination. Water sampling began at the end of 2018 and continued through July 2021; during that time, 48 water samples were collected from various types of surface waters. The US EPA 1623 methodology was used to detect (oo)cysts of G. intestinalis and Cryptosporidium spp., while the detection of T. gondii was performed by PCR with prior concentration of the sample. According to the results of immunofluorescence assays, evidence of at least one of the three protozoa were found in 24 of the 48 samples (50%, 24/48). G. intestinalis cysts were found in 14 samples (29.2%, 14/48), Cryptosporidium spp. oocysts in five (10.4%, 5/48), while cysts and oocysts of both parasites were found in three samples (6.25%, 3/48). G. intestinalis β-giardin gene was detected by PCR amplification in eight (16.6%, 8/48) samples, but the attempts to amplify any of the four genes used to detect Cryptosporidium spp. remained unsuccessful. T. gondii gDNK was detected in four samples (8.3%, 4/48), firstly by amplification of the 529 bp repetitive fragment and then confirmed by detection of the GRA6 and SAG2 gene sequences. Typing of G. intestinalis assemblages was successful in three samples. Assemblage A was detected in one, and assemblage B in the remaining two samples. There was no association of hydro-morphological water quality with the presence of parasites in water. Also, using qGIS software, the locations where the sampling was performed as well as their status in relation to sample positivity were shown on the map of the Republic of Serbia. Based on that, a greater presence of protozoa was observed in the waters in the Mačva and Srem districts in Western Serbia, as well as in the Pomoravlje and Šumadija districts in Central Serbia. Results of this Dissertation showed, for the first time in this country, that parasitic protozoa G. intestinalis, Cryptosporidium spp. and T. gondii contaminate Serbian watercourses. These findings could be used to establish a prevention and control strategy for protecting human and animal health, primarily by preventing waterborne epidemics. Also they laid a foundation for further research in this area that could improve the understanding of the scope and precise distribution of parasitic protozoa contamination in Serbian surface waters

In Vivo and In Vitro Virulence Analysis of Four Genetically Distinct Toxoplasma gondii Lineage III Isolates

Toxoplasma gondii archetypes II and III are mildly virulent, yet virulence of variant strains is largely unknown. While lineage II dominates in humans in Europe, lineage III strains are present in various intermediate hosts. In Serbia, lineage III represents 24% of the population structure and occurs most frequently in domestic animals, implying a significant presence in the human food web. In this study, the virulence of four genetically distinct lineage III variants was assessed in vivo and in vitro. In vivo, two strains were shown to be intermediately virulent and two mildly virulent, with cumulative mortalities of 69.4%, 38.8%, 10.7%, and 6.8%, respectively. The strain with the highest mortality has previously been isolated in Europe and may be endemic; the strain with the lowest mortality matches ToxoDB#54, while the remaining two represent novel genotypes. Identical alleles were detected at ROP5, ROP16, ROP18, and GRA15. A set of in vitro analyses revealed proliferation and plaque formation as virulence factors. Higher levels of expression of ENO2 in intermediately virulent strains point to enhanced metabolism as the underlying mechanism. The results suggest that metabolic attenuation, and possibly stage conversion, may be delayed in virulent strains

Mortality rate of lip, oral cavity and pharynx malignant tumors in Serbia within a period 1991-2009

Background/Aim. Lip, oral cavity and pharynx malignant tumors account for 3.7% of all cancer deaths worldwide, with significant geographic variations in frequency and distribution. The aim of this descriptive epidemiologic study was to analyze the mortality rate of lip, oral cavity and pharynx malignant tumors in Serbia proper within a period 1991-2009. Methods. Mortality rates standardized directly using the world population as the standard were used in data analysis. Linear trend and regression analyses were used to analyze rate trends in mortality. Results. The Serbian population demonstrated an increase in the mortality of lip, oral cavity and pharynx malignant tumors (y = 3.32 + 0.03×; p = 0.002; average annual percent change = + 0.8). The male population showed a significant increase in mortality trend (y = 5.90 + 0.03×; p = 0.020; % change = + 0.9), while the female population did not show a significant increase in mortality. The male/female cancer mortality ratio was 5.5:1. Mortality rates for lip, oral cavity and pharynx cancer increased with age in both genders, with rates being the highest in the population aged 85 and older. Increasing trends of lip, oral cavity and pharynx cancer mortality were observed in males aged 50-54; the average annual percent change was + 7.4 % (95% CI, 6.2-9.0). The population of both genders aged 55-59 demonstrated an increase in lip, oral cavity and pharynx cancer mortality, the increase being + 1.8% (95% CI, 1.4-2.2) in men and + 34.3% (95% CI, 28.4-40.2) in women. Conclusion. The increasing trend in lip, oral cavity and pharynx cancer mortality points to the necessity to investigate etiology and improve primary and secondary prevention measures

Epidemiology of Taenia solium infection in the Russian Federation in the last 20 years: a systematic review

Taenia solium is a zoonotic parasite that causes taeniasis and cysticercosis in humans (as final hosts) and cysticercosis in pigs (as intermediate hosts). The Russian Federation (RF) is traditionally considered as endemic for this zoonosis. However, the epidemiological data on T. solium infection have not been reviewed for the past 20 years, in which time dynamic economical and societal changes have occurred in the RF. The aim of this systematic review was to analyse the status of T. solium infection in RF in the 2000–2019 period. A literature search was conducted, which collected published articles, grey literature and official data on the epidemiology of T. solium taeniasis and cysticercosis in the RF published from 2000. From a total of 2021 articles and 24 official reports originally returned by the search, data were extracted from 12 full text articles and 11 official reports. Taenia solium taeniasis was continuously reported in the RF between 2000 and 2019, with a tenfold decrease in the incidence, from 0.2 per 100,000 population in 2000 to 0.023/100,000 in 2019. Also, the number of administrative units where taeniasis was detected continuously decreased. Cysticercosis in pigs had a declining trend after 2006. In conclusion, although decreasing, T. solium infection is still endemic in several regions and suspected to be endemic in most of the RF

Distribution of niclosamide residues in meat and internal organs of common carp

Niclosamide is applied for the treatment of the disease of common carp hatchlings caused by Bothriocephalus acheilognathi. One of the main characteristics of this drug is a short half-life in water. A series of experiments were performed to determine the distribution of niclosamide residues in the organs and meat of the carp, in controlled conditions. It was shown that 72.42% of niclosamide was deposited in the liver, 18.79% in the kidney and 7.79% in the spleen. However, only about 3% of deposited niclosamide was detected in meat. This drug provides rapid and effective treatment of fish, completely eliminating the tapeworms

Herpesvirusne bolesti ciprinida

Cyprinidae, the largest known fish family including carp and minnows, has worldwide distribution with many species that are economically important in aquaculture. As would be expected, many viral pathogens can affect this group. The most pathogenic of these are the rhabdoviruses, a reovirus and three herpesviruses. Cyprinid herpesviruses can cause significant economic losses in aquaculture, and some of these viruses are oncogenic. The three herpesviruses are closely related but cause distinctly different diseases. Fish pox, caused by cyprinid herpesvirus 1 (CyHV-1), is one of the oldest known fish diseases, being recorded as early as 1563. It takes the form of a hyperplastic, epidermal papilloma on common carp. Cyprinid herpesvirus 2 (CyHV-2) is causative agent of herpesviral hematopoietic necrosis (HVHN). The herpesvirus was first isolated from cultured goldfish in Japan. It causes a severe epizootic but no external clinical signs were apparent on affected fish. One of the most economically important and researched viral diseases of carp is koi herpesviral disease caused by cyprinid herpesvirus 3 (CyHV-3). The aim of this paper is to present the current knowledge on herpesvirus diseases of the cyprinids.Ciprinide, najveća poznata familija riba, koja obuhvata šaranske vrste riba, je rasprostranjena širom sveta, sa mnogim vrstama koje imaju veliki ekonomski značaj u akvakulturi. Kao što bi se moglo očekivati, mnogi virusi mogu delovati na ovu grupu, među kojima su od najvećeg značaja pripadnici familija rabdovirusa, reovirusa i herpesvirusa. Herpesvirusi ciprinida mogu izazvati značajne ekonomske gubitke u akvakulturi, a neki od njih virusa su onkogeni. Iako su veoma srodni herpesvirusi ciprinida izazivaju različite bolesti sa veoma različitim karakteristikama. Boginje riba, koje izaziva herpesvirus 1 (CyHV-1), je jedno od najstarijih poznatih bolesti riba, utvrđeno još 1563. godine. Ovo oboljenje se po pravilu ispoljava u vidu hiperplastičnih papilomatoznih promena epiderma šarana. Herpesvirus 2 (CyHV-2) je uzročnik herpesvirusne hematopoezne nekroze (HVHN). Ovaj virus je prvi put izolovan iz zlatnih ribica u Japanu. Kao posledica delovanja uzročnika dolazi do pojave značajnih epizootija bez izraženih kliničkih znakova kod obolelih riba. Jedno od ekonomski najznačajnijih virusnih oboljenja šarana je koi herpesviroza izazvana ciprinim herpesvirusom 3 (CyHV-3). Cilj ovog rada je da se predstave aktuelna saznanja o oboljenjima ciprinida izazvanih herpesvirusima

U potrazi za najboljim rešenjem - akvaponika

Aquaponic production combines intensive production with waste recycling and water conservation. Aquaponic join recirculating aquaculture with hydroponics to use nutrient waste from aquaculture as an input to plant growth. Traditional aquaculture systems treat or dispose nutrient-rich wastewater. In aquaponics, the waste products from the fish are converted by a bio-filter into soluble nutrients which are absorbed by the plants, and allow ‘clean’ water to be returned back to the fish. Thus, it produces valuable fish protein with a minimal pollution of fresh water resources, while at the same time producing horticultural crops. Fish in aquaponic production systems can be raised in ponds, tanks, or other containers. Plants are grown separately in hydroponic tanks, submerged in water but suspended in gravel, sand, perlite, or porous plastic films, as well as on floating rafts. Systems vary greatly in design and construction, but most perform the following key functions: finfish and plant production, removal of suspended solids, and bacterial nitrification. This review discusses applications, effects and perspective of aquaponics.Akvaponika kombinuje intenzivnu proizvodnju sa reciklažom otpadnih materija i očuvanjem vode, i povezuje akvakulturu sa hidroponikom u cilju korišćenja hranljivih materija iz akvakulture za rast biljaka. U tradicionalnoj akvakulturi, otpadna voda bogata hranljivim materijama se ne koristi. U akvaponici, produkti nastali prilikom gajenja riba se pomoću biofiltera konvertuju u rastvorljive materije koje biljke apsorbuju, a “čista” voda se vraća ponovo u proizvodnju. Na ovaj način se omogućava proizvodnja visoko vrednih animalnih proteina, uz minimalno zagađenje vode, dok se istovremeno dobijaju proizvodi hortikulture. Postoji veliki broj sistema za gajenje, različitog dizajna i konstrukcije, ali se svi baziraju na zadovoljavanju ključnih funkcija: proizvodnji riba i biljaka, uklanjanju rastvorenih materija i bakterijskoj nitrifikaciji. U radu su prikazani primena, efekti i perspektive akvaponike

Influence of MN doping on the evolution of microstructure and optical properties of mechanically activated SrTiO3 powders

Manganese doped SrTiO3 powders with various manganese dioxide weight percentages in the range of 1.5, 3 and 6 wp% were prepared by a solid-state method in the presence of mechanical activation (10, 30 and 120 minutes). A systematic investigation by X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size analisys (PSA), Brunauer-Emmett-Teller (BET) methods and Raman spectroscopy has been undertaken to evaluate the role of dopants on the microstructural and morphological study of the perovskite oxide obtained. The optical properties of the different manganese doped and activated SrTiO3 powders have been also evaluated. Mn insertion in SrTiO3 is discussed considering the possibility for Mn ions to occupy both Ti4+ and Sr2+ sites as well as manganese segregation and Mn incorporation-related non-homogeneities. The results demonstrated that Mn has substituted into the lattice and surface layers of the particles of SrTiO3 powders and the absorption onset shifted to higher values of wavelengths with increasing time of activation and dopant concentration. The lowest value of the band gap (Eg=3.10 eV) was registered with the longest activation for 120 minutes and the highest concentration of dopant (6 wp%). Combining doping with mechanical activation lower values of band gap can be achieved and that fact could be used in subsequent studies to make Mn-SrTiO3 more suitable visible-light photocatalysts

Toxoplasma gondii Genotypes Circulating in Serbia—Insight into the Population Structure and Diversity of the Species in Southeastern Europe, a Region of Intercontinental Strain Exchange

In Europe, Toxoplasma gondii lineage II is dominant, and ToxoDB#1 the most frequently occurring genotype. The abundance of lineage III genotypes varies geographically and lineage I are rare, yet present in several regions of the continent. Data on the T. gondii population structure in southeastern Europe (SEE) are scarce, yet necessary to appreciate the diversity of the species in Europe. To help fill this gap, we genotyped 67 strains from nine species of intermediate hosts in Serbia by MnPCR-RFLP, determined the population structure, and identified the genotypes using ToxoDB. A neighbor-joining tree was also constructed from the isolates genotyped on nine loci. While 42% of the total genotype population consisted of ToxoDB#1 and ToxoDB#2, variant genotypes of both lineages comprised 46% of the population in wildlife and 28% in domestic animals and humans. One genotype of Africa 4 lineage was detected in a human sample. Interestingly, the findings include one lineage III variant and one II/III recombinant isolate with intercontinental distribution, which appear to be moderately related to South American genotypes. Based on these findings, SEE is a region of underappreciated T. gondii genetic diversity and possible strain exchange between Europe and Africa