Bacteria resistant to selenium

Selen je esencijalni element u tragovima za sve tri domene ţivih bića (bakterije, arheje, eukarioti), ali je u visokim koncentracijama toksičan. Selenovi oksianioni (selenat i selenit) su dobro topivi u vodi i vrlo toksični, te u okoliš dospijevaju prirodnim procesima ili ljudskom djelatnošću (industrija, poljoprivreda). Neke bakterije su sposobne podnijeti veće koncentracije toksičnih selenovih spojeva, odnosno selenovih oksianiona u svojoj okolini, a to im je omogučeno različitim mehanizmima poput redukcije selenovih oksianiona u procesu anaerobne respiracije ili rjeĎe uočene redukcije u aerobnim uvijetima procesima detoksifikacije. Bakterije koje reduciraju selenove oksianione proizvode nanosfere elementarnog selena sa specifičnim fizikalnim svojstvima, ili ih rjeĎe metiliraju i reduciraju do selenida stvarajući tako plinovite metilirane selenove spojeve. Cilj ovog rada je sakupiti sadašnja saznanja o bakterijama koje imaju neku vrstu rezistencije na selen, odnosno na njegove toksične spojeve, kao i o mehanizmima kojima to postiţu. Mehanizmi koji bakterijama omogućavaju rezistenciju na selen nisu još sasvim razjašnjeni, pogotovo oni koji se dogaĎaju u aerobnim uvijetima, te su otvorena mnoga pitanja poput načina izlučivanja samih nanosfera selena iz stanica bakterija.Selenium is an essential trace element for living creatures from all three domains of life (Bacteria, Archaea, Eukaryota), but it is toxic in high concentrations. Selenium oxyanions (selenate and selenite) are water soluble and highly toxic, and get released in the environment through natural processes or through human activity (industry, agriculture). Some bacterias are capable of coping with higher concentrations of toxic selenic forms, i. e. selenium oxyanions in its environment, and that is possible due to different mechanisms possessed by those bacteria like reduction of selenium oxyanions in a process of anaerobic respiration or, not as often, aerobic reduction through processes of detoxification. Bacteria that reduce selenium oxyanions produce nanospheres of elemental selenium that have specific physical properties, or rarely methylate them and reduce them to selenide, producing gaseous methylated selenium compounds. The main objective of this paper is to collect the current knowledge of bacteria that exhibit some kind of resistance to selenium – to its toxic forms, as well as the mechanisms whit which it is obtained. The mechanisms that provide resistance to selenium are not jet well explained, especially the ones that occure in aerobic conditions, and many questions remain unanswered like the ones regarding the expulsion of the selenium nanospheres out of the bacteria cells

What is new in Croatian mayfly fauna?

Here we present a first record of Baetis vardarensis Ikonomov, 1962 in Croatian freshwater habitats. The species was collected in February and March 2020 at two sites in the Sava River. With this record, Croatian mayfly species richness increased to a total of 85 species. In addition, one of the species previously known only from literature, Kageronia fuscogrisea (Retzius, 1783), was confirmed in Croatia. The species was collected in the Rečica River, in March 2020. These results confirm that our knowledge about mayfly fauna in different regions of Balkan Peninsula is still incomplete and is increasing with systematic studies

Izvori wikipedije: relevantne i /ili ne relevantne informacije

Pojavom interneta i postupnim stvaranjem globalne informacijske mreže dolazi do informacijske revolucije devedesetih godina dvadesetog stoljeća. Wikipedia je online enciklopedija otvorenog sadržaja (www.wikipedia.org) uvjerljiv je primjer proizvodnje otvorenog koda, čiji otvoreni slobodni sadržaj može bilo tko urediti. Wikipedija je međunarodni internetski projekt koji pokušava stvoriti besplatnu enciklopediju u više jezika, koja je nastala djelovanjem volontera pomoću Wiki softvera. Wikipedija potiče suradnike da postanu "registrirani korisnici" iznošenjem prednosti korisničkog računa, uključujući izgradnju ugleda u zajednici. Sav sadržaj Wikipedije licenciran je pod licencom GNU Free Documentation. Vrednovanje sadržaja Wikipedije pomaže čitatelju pri identifikaciji kvalitetnih članaka, a sama procjena kvalitete predstavlja osobit izazov, prvenstveno zbog dinamičke orijentacije ove mrežne enciklopedije i pripadajućih karakteristika koje uvelike otežavaju ovaj posao. Vandalizam obuhvaća dodavanje, brisanje ili modificiranje teksta članka, a istraživanja pokazuju da destruktivne izmjene čine 3-6% od ukupnog broja. Mnoga istraživanja pokazuju da se Wikipedija kao izvor informacija koristi u privatne, ali i akademske svrhe jer pruža trenutne i sažete informacije na jednostavan način. Cilj ovog rada je pružiti kratak uvod u povijest Wikipedije njezin nastanak i razvoj, informacije koje ona pruža te vrednovanje tih informacija. Rad će pokušati donijeti zaključak koliko su informacije na Wikipediji legitimne te je li ih moguće koristiti u akademske svrhe

Bacteria resistant to selenium

Selen je esencijalni element u tragovima za sve tri domene ţivih bića (bakterije, arheje, eukarioti), ali je u visokim koncentracijama toksičan. Selenovi oksianioni (selenat i selenit) su dobro topivi u vodi i vrlo toksični, te u okoliš dospijevaju prirodnim procesima ili ljudskom djelatnošću (industrija, poljoprivreda). Neke bakterije su sposobne podnijeti veće koncentracije toksičnih selenovih spojeva, odnosno selenovih oksianiona u svojoj okolini, a to im je omogučeno različitim mehanizmima poput redukcije selenovih oksianiona u procesu anaerobne respiracije ili rjeĎe uočene redukcije u aerobnim uvijetima procesima detoksifikacije. Bakterije koje reduciraju selenove oksianione proizvode nanosfere elementarnog selena sa specifičnim fizikalnim svojstvima, ili ih rjeĎe metiliraju i reduciraju do selenida stvarajući tako plinovite metilirane selenove spojeve. Cilj ovog rada je sakupiti sadašnja saznanja o bakterijama koje imaju neku vrstu rezistencije na selen, odnosno na njegove toksične spojeve, kao i o mehanizmima kojima to postiţu. Mehanizmi koji bakterijama omogućavaju rezistenciju na selen nisu još sasvim razjašnjeni, pogotovo oni koji se dogaĎaju u aerobnim uvijetima, te su otvorena mnoga pitanja poput načina izlučivanja samih nanosfera selena iz stanica bakterija.Selenium is an essential trace element for living creatures from all three domains of life (Bacteria, Archaea, Eukaryota), but it is toxic in high concentrations. Selenium oxyanions (selenate and selenite) are water soluble and highly toxic, and get released in the environment through natural processes or through human activity (industry, agriculture). Some bacterias are capable of coping with higher concentrations of toxic selenic forms, i. e. selenium oxyanions in its environment, and that is possible due to different mechanisms possessed by those bacteria like reduction of selenium oxyanions in a process of anaerobic respiration or, not as often, aerobic reduction through processes of detoxification. Bacteria that reduce selenium oxyanions produce nanospheres of elemental selenium that have specific physical properties, or rarely methylate them and reduce them to selenide, producing gaseous methylated selenium compounds. The main objective of this paper is to collect the current knowledge of bacteria that exhibit some kind of resistance to selenium – to its toxic forms, as well as the mechanisms whit which it is obtained. The mechanisms that provide resistance to selenium are not jet well explained, especially the ones that occure in aerobic conditions, and many questions remain unanswered like the ones regarding the expulsion of the selenium nanospheres out of the bacteria cells

Bacteria resistant to selenium

Selen je esencijalni element u tragovima za sve tri domene ţivih bića (bakterije, arheje, eukarioti), ali je u visokim koncentracijama toksičan. Selenovi oksianioni (selenat i selenit) su dobro topivi u vodi i vrlo toksični, te u okoliš dospijevaju prirodnim procesima ili ljudskom djelatnošću (industrija, poljoprivreda). Neke bakterije su sposobne podnijeti veće koncentracije toksičnih selenovih spojeva, odnosno selenovih oksianiona u svojoj okolini, a to im je omogučeno različitim mehanizmima poput redukcije selenovih oksianiona u procesu anaerobne respiracije ili rjeĎe uočene redukcije u aerobnim uvijetima procesima detoksifikacije. Bakterije koje reduciraju selenove oksianione proizvode nanosfere elementarnog selena sa specifičnim fizikalnim svojstvima, ili ih rjeĎe metiliraju i reduciraju do selenida stvarajući tako plinovite metilirane selenove spojeve. Cilj ovog rada je sakupiti sadašnja saznanja o bakterijama koje imaju neku vrstu rezistencije na selen, odnosno na njegove toksične spojeve, kao i o mehanizmima kojima to postiţu. Mehanizmi koji bakterijama omogućavaju rezistenciju na selen nisu još sasvim razjašnjeni, pogotovo oni koji se dogaĎaju u aerobnim uvijetima, te su otvorena mnoga pitanja poput načina izlučivanja samih nanosfera selena iz stanica bakterija.Selenium is an essential trace element for living creatures from all three domains of life (Bacteria, Archaea, Eukaryota), but it is toxic in high concentrations. Selenium oxyanions (selenate and selenite) are water soluble and highly toxic, and get released in the environment through natural processes or through human activity (industry, agriculture). Some bacterias are capable of coping with higher concentrations of toxic selenic forms, i. e. selenium oxyanions in its environment, and that is possible due to different mechanisms possessed by those bacteria like reduction of selenium oxyanions in a process of anaerobic respiration or, not as often, aerobic reduction through processes of detoxification. Bacteria that reduce selenium oxyanions produce nanospheres of elemental selenium that have specific physical properties, or rarely methylate them and reduce them to selenide, producing gaseous methylated selenium compounds. The main objective of this paper is to collect the current knowledge of bacteria that exhibit some kind of resistance to selenium – to its toxic forms, as well as the mechanisms whit which it is obtained. The mechanisms that provide resistance to selenium are not jet well explained, especially the ones that occure in aerobic conditions, and many questions remain unanswered like the ones regarding the expulsion of the selenium nanospheres out of the bacteria cells

Engagement with digital media in home environment and school readiness in croatian preschool children

Our aim was to investigate the use of various digital media for different purposes in home environment and its relation to the level of school readiness, namely graphomotor skills, logical reasoning and letter knowledge in children aged 6 to 7. Children (N=92) were tested for graphomotor skills, logical reasoning and letter knowledge while their parents completed a questionnaire providing us with the data about their own and their children’s access to digital media in home environment. Results show low but significant negative correlations between the time spent using a computer on weekends and the number of letters children can identify correctly, as well as between the time spent using a smartphone on weekends and children’s graphomotor skills.info:eu-repo/semantics/publishedVersio

Mayflies of the Bednja River, Croatia

Here we present the results of a mayfly study conducted on a hydromorphologically altered lowland river in Croatia, the Bednja River. Twenty-two mayfly species were recorded, Baetis fuscatus (Linnaeus, 1761) and Serratella ignita (Poda, 1761) being the most widespread and Paraleptophlebia submarginata (Stephens, 1836) and Cloeon dipterum (Linnaeus, 1761) the rarest species. A significant increase in mayfly species richness was observed along the river course. Nevertheless, cluster analysis showed that their assemblages were not grouped according to the study position along the Bednja River. The lowest species richness and diversity were recorded for the spring area. Surprisingly, the highest species richness was found at a site with moderate hydromorphological alterations, and the highest diversity at a site with severe hydromorphological alterations. This could be because the river is connected to numerous lateral streams and a variety of microhabitats are available. New distribution records in Croatia are presented for some rare species in Croatian freshwater habitats, such as Heptagenia longicauda (Stephens, 1836). Ephemera lineata Eaton, 1870 was recorded for the first time in the Pannonian lowland ecoregion (ER 11) in Croatia. Caenis cf. pseudorivulorum Keffermüller, 1960 has not yet been recorded in Croatian freshwater habitats, but since our identifications are based on juvenile specimens, its occurrence is still to be confirmed

The effect of the FKBP5 polymorphisms, childhood trauma and neuroticism on psychotic disorders.

Spektar psihotičnih poremećaja, od kojih je najteže oboljenje shizofrenija, čine složene nasledne poligenske bolesti kod kojih, pored genetičkih faktora, bitnu ulogu u etiologiji bolesti imaju psihosocijalni faktori rizika, kao što su trauma u detinjstvu i neuroticizam. Neurobiološki mehanizam kojim bi se objasnio uticaj psihosocijalnih faktora rizika na obolevanje od psihotičnog poremećaja još uvek nije poznat. Jedan od ponuđenih modela bolesti kojim bi se pokazala njihova veza jeste dijateza-stres model. Ovaj model ističe značaj interakcije biološke vulnerabilnost na stres (povišena stres-senzitivnost) i nepovoljnih životnih događaja u ranom životnom dobu (trauma u detinjstvu) na podložnost za nastanak psihotičnog poremećaja. Takođe, psihološki faktor rizika (neuroticizam) uključen je u ovaj model s obzirom da je neuroticizam marker stresvulnerabilnosti, odnosno fenotip kojim se opisuje povišena senzitivnost na stres. Interesantno je da je povišena senzitivnost na stres uočena ne samo kod pacijenata sa psihotičnim poremećajem, već i kod njihovih prvostepenih srodnika, što govori u prilog nasledne osnove stres-senzitivnosti. Najprihvaćeniji neurobiološki mehanizam dijateza-stres modela jeste poremećaj aktivnosti hipotalamo-hipofizno-adrenalne (HPA) osovine. Molekularna osnova disregulacije HPA osovine proučava se najviše u domenu poremećene glukokortikoidne signalizacije, gde glavnu ulogu ima glukokortikoidni receptor (GR). Ključni regulator GR jeste protein FK506-binding protein 51(FKBP51), ko-šaperon (co-chaperone) heatschock proteina 90 (hsp90), koji posreduje u translokaciji kortizol-GR kompleksa iz citoplazme u nukleus, a time i u GR-posredovanoj genskoj transkripciji. Gen koji kodira ovaj protein jeste FKBP5 gen. Ispitivanja polimorfizama u FKBP5 genu pokazala su da određeni rizični aleli imaju funkcionalni uticaj na ekspresiju FKBP51, kao i da u interakciji sa stresnim događajima predstavljaju značajne prediktore za različitu psihopatologiju indukovanu stresom, među kojima su i psihotični pormećaji...Psychotic disorders and schizophrenia, as the most severe psychotic disorder, are complex, heritable and polygenic diseases in which, beside genetics influence, psyschosocial risk factors, such as childhood trauma and neuroticism, play important roles. Neurobiological mechanisms which could explain relationship between psychosocial risk factors and psychotic disorders are still unknown. One of the proposed model is diathesisstres model of psychosis. This model suggests that interaction between biological vulnerability to stress (increased stress-sensitivity) and stressful life events is crucial for the development of psychotic disorders. Additionally, this model highlights the role of psychological risk factor (neuroticism) as the most promising marker for stressvulnerability, and thus phenotype for increased stress-sensitivity. Notably, increased stress-sensitivity is observed not only in patients with psychotic dirorders but also in their healthy siblings, suggesting that stress-sensitivity could be heritable marker. The most accepted neurobiological mechanism of diathesis-stress model is altered activity of the hypothalamic-pituitary-adrenal (HPA) axis. Molecular pathway for dysregulation of the HPA axis is studied mostly in the domain of impaired glucocorticoid signalization, where the glucocorticoid receptor (GR) has the main role. A key regulator of the GR activity is FK506-binding protein 51 (FKBP51), co-chaperone (co-chaperone) of heat-schock protein 90 (hsp90), which mediates the translocation of cortisol-GR complex from the cytoplasm to the nucleus, and thus in the GR-mediated gene transcription. The gene encoding this protein is FKBP5 gene. Studies of the FKBP5 polymorphisms have shown that certain risk alleles have functional significance on the expression of FKBP51, and interact with stressful life events to predict stress-induced psychopathology such as psychotic disorders. Given that the role of FKBP5 gene in diathesis-stress model of psychotic disorders is a new topic in psychotic research field, further investigation of the impact of the FKBP5 genetic variants and childhood trauma on the disease, as well as its potential effect on the phenotype of stress-sensitivity (neuroticism) are warranted..

Novi nalaz razmnožavanja vrste Lindenia tetraphylla (Vander Linden, 1825) (Odonata, Gomphidae) na sjeverozapadnoj granici njene rasprostranjenosti

A total of 12 dragonfly species were recorded at Vlačine Reservoir in the Dinaric Western Balkan region (ER 5) in Croatia. Habitat conditions, i.e. vegetation structure and physico-chemical water properties of the reservoir, are presented and discussed. Habitat conditions were suitable for life cycle completion of Mediterranean species such as Lindenia tetraphylla and Selysiothemis nigra. Exuviae of L. tetraphylla represent new evidence of the species’ reproduction in the north-western border of its distribution.Na akumulaciji Vlačine, smještenoj u dinaridskoj ekoregiji (ER 5, Dinaridski zapadni Balkan) u Hrvatskoj, zabilježeno je ukupno 12 vrsta vretenaca. U radu su prikazani i raspravljeni okolišni uvjeti na istraživanom staništu, prvenstveno struktura vegetacije i fizikalno-kemijski čimbenici vode. Stanišni uvjeti akumulacije bili su pogodni za uspješno završavanje životnog ciklusa mediteranskih vretenaca poput vrsta Lindenia tetraphylla i Selysiothemis nigra. Zabilježeni svlakovi vrste L. tetraphylla predstavljaju novi nalaz razmnožavanja ove vrste na sjeverozapadnoj granici njene rasprostranjenosti

Biochemical Bone Turnover Markers: Significance in Patients with Osteoporosis

Osteoporosis is a systemic disease, which is characterized by reduced bone mass and microarchitectural deterioration of the bone tissue, resulting in an increased risk of fracture. Since osteoporosis is today a disease with high incidence rate, the aim of this study was to determine a correlation between bone mass density (BMD) and concentration of biochemical bone turnover markers – deoxypyridinoline (DPD) as a marker of bone resorption, and osteocalcin (OC) as a marker of bone formation. The study included 70 women between 33 and 76 years of age. In all women BMD was measured by Dual X-ray Absorptiometry (DXA) as a T-score. T-score was defined as the number of standard deviations of the bone mass density from the maximum bone mass density in young adults. According to T-score, patients were divided into three groups: patients with osteoporosis, patients with osteopenia and control group consisting of patients with normal T-score. DPD in urine and OC in serum were measured by a routine procedure. Results: a negative correlation between BMD and concentration of bone turnover marker was discovered. One-way analysis of variance and Pearson correlation were used for statistical analysis, with a P value <0.05 being considered significant. Although a negative correlation was discovered, we concluded that both procedures have a significant role in diagnosis and follow-up of patients with osteoporosis