Revision of the Cretaceous shark Protoxynotus (Chondrichthyes, Squaliformes) and early evolution of somniosid sharks

Due to the peculiar combination of dental features characteristic for different squaliform families, the position of the Late Cretaceous genera Protoxynotus and Paraphorosoides within Squaliformes has long been controversial. In this study, we revise these genera based on previously known fossil teeth and new dental material. The phylogenetic placement of Protoxynotus and Paraphorosoides among other extant and extinct squaliforms is discussed based on morphological characters combined with DNA sequence data of extant species. Our results suggest that Protoxynotus and Paraphorosoides should be included in the Somniosidae and that Paraphorosoides is a junior synonym of Protoxynotus. New dental material from the Campanian of Germany and the Maastrichtian of Austria enabled the description of a new species Protoxynotus mayrmelnhofi sp. nov. In addition, the evolution and origin of the characteristic squaliform tooth morphology are discussed, indicating that the elongated lower jaw teeth with erected cusp and distinct dignathic heterodonty of Protoxynotus represents a novel functional adaptation in its cutting-clutching type dentition among early squaliform sharks. Furthermore, the depositional environment of the tooth bearing horizons allows for an interpretation of the preferred habitat of this extinct dogfish shark, which exclusively occupied shelf environments of the Boreal- and northern Tethyan realms during the Late Cretaceous.publishedVersio

Srednjoeocenska starost navodnih oligocenskih sedimenata u flišu Pazinskoga bazena (Istra, Vanjski Dinaridi)

The dating of the flysch sediments of the coastal Dinarides is critical for considering the evolution of the Dinaric chain. The flysch of the Pazin Basin, Istria has been considered to be Late Lutetian to Late Eocene in age by many workers. The recently reported Late Oligocene age of a part of this flysch (ŠPARICA et al., 2005) is highly relevant when considering the sedimentary and tectonic evolution of the area, as well as the western Dinarides in general. The importance of the Late Oligocene dating, and the character of the succession of the area in question, which shows similarities with Middle Eocene sediments in other parts of the basin, provoked the need for a reevaluation of the dating of these specific sediments. The results presented here support the Middle Eocene age of these sediments, which is consistent with the dating proposed by previous workers, and agrees with the character of the relevant sedimentary succession.Dosadašnja istraživanja i shvaćanja, kako o starosti, tako i karakteru slijeda sedimenata fliša Pazinskoga bazena u Istri, upućivala su na ukupnu starost fliša od kasnoga lutecija do starijega priabonija. Međutim, nedavno su prikazani podaci, prema kojima jedan dio tih sedimenata odgovara kasnom oligocenu, što je bitna novost za razmatranje razvitka toga bazena, kao i orogena Dinarida. Ovaj rad odgovara na potrebu dodatne provjere starosti tih sedimenata zbog važnosti odnosnoga datiranja. Prikazani rezultati temelje se na usporedbi karaktera i slijeda sedimenata iz predjela odakle potječu nedavni podaci o oligocenu sa sedimentima drugih dijelova Pazinskoga bazena, te na biostratigrafskom datiranju pomoću planktonskih foraminifera i nanoplanktona. Ustanovljene biozone odgovaraju gornjem luteciju i donjem bartoniju, dakle, donjemu dijelu ukupnoga raspona starosti Pazinskoga fliša

The Polymorphisms of Genes Encoding Catalytic Antioxidant Proteins Modulate the Susceptibility and Progression of Testicular Germ Cell Tumor

The simultaneous analysis of redox biomarkers and polymorphisms encoding for regulatory and catalytic antioxidant proteins was performed in order to evaluate their potential role in the development of testicular germ cell tumor (GCT), as well as the progression of the disease. NRF2 (rs6721961), GSTM3 (rs1332018), SOD2 (rs4880) and GPX3 (rs8177412) polymorphisms were assessed in 88 patients with testicular GCT (52 with seminoma) and 88 age-matched controls. The plasma levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), thiol groups and the plasma activity of glutathione peroxidase were measured. A significant association between variant GPX3*TC+CC genotype and risk of overall testicular GCT, as well as seminoma development, was found. Moreover, carriers of variant SOD2*TT genotype were at almost 3-fold increased risk of seminoma development. Interestingly, combined SOD2*TT/GPX3*TC+CC genotype conferred a 7-fold higher risk for testicular GCT development. Finally, variant GSTM3*AC+CC genotype was associated with a higher risk for the development of advanced diseased. The presence of assessed genetic variants was not associated with significantly higher levels of redox biomarkers in both testicular GCT patients, as well as in those diagnosed with seminoma. In conclusion, the polymorphic expression of certain antioxidant enzymes might affect susceptibility toward testicular GCT development, as well as the progression of the disease

Paleogeographic evolution of the Southern Pannonian Basin: 40Ar/39Ar age constraints on the Miocene continental series of notthern Croatia

The Pannonian Basin, originating during the Early Miocene, is a large extensional basin incorporated between Alpine, Carpathian and Dinaride fold-thrust belts. Back-arc extensional tectonics triggered deposition of up to 500-m-thick continental fluvio-lacustrine deposits distributed in numerous sub-basins of the Southern Pannonian Basin. Extensive andesitic and dacitic volcanism accompanied the syn-rift deposition and caused a number of pyroclastic intercalations. Here, we analyze two volcanic ash layers located at the base and top of the continental series. The lowermost ash from Mt. Kalnik yielded an 40Ar/39Ar age of 18.07 ± 0.07 Ma. This indicates that the marine-continental transition in the Slovenia-Zagorje Basin, coinciding with the onset of rifting tectonics in the Southern Pannonian Basin, occurs roughly at the Eggenburgian/ Ottnangian boundary of the regional Paratethys time scale. This age proves the synchronicity of initial rifting in the Southern Pannonian Basin with the beginning of sedimentation in the Dinaride Lake System. Beside geodynamic evolution, the two regions also share a biotic evolutionary history: both belong to the same ecoregion, which we designate here as the Illyrian Bioprovince. The youngest volcanic ash level is sampled at the Glina and Karlovac sub-depressions, and both sites yield the same 40Ar/39Ar age of 15.91 ± 0.06 and 16.03 ± 0.06 Ma, respectively. This indicates that lacustrine sedimentation in the Southern Pannonian Basin continued at least until the earliest Badenian. The present results provide not only important bench marks on duration of initial synrift in the Pannonian Basin System, but also deliver substantial backbone data for paleogeographic reconstructions in Central and Southeastern Europe around the Early–Middle Miocene transition

The Usability of E-learning Platforms in Higher Education: A Systematic Mapping Study

The use of e-learning in higher education has increased significantly in recent years, which has led to several studies being conducted to investigate the usability of the platforms that support it. A variety of different usability evaluation methods and attributes have been used, and it has therefore become important to start reviewing this work in a systematic way to determine how the field has developed in the last 15 years. This paper describes a systematic mapping study that performed searches on five electronic libraries to identify usability issues and methods that have been used to evaluate e-learning platforms. Sixty-one papers were selected and analysed, with the majority of studies using a simple research design reliant on questionnaires. The usability attributes measured were mostly related to effectiveness, satisfaction, efficiency, and perceived ease of use. Furthermore, several research gaps have been identified and recommendations have been made for further work in the area of the usability of online learning

AUTONOMNI KONCEPTI I STATUS QUO METOD: U POTRAZI ZA DOSLEDNOM ZAŠTITOM LJUDSKIH PRAVA PRED EVROPSKIM NADNACIONLNIM SUDOVIMA

The accession of the European Union to the European Convention on Human Rights is currently being renegotiated, but this remains a rocky and time-consuming process. Mostly relying on doctrinal method, the authors examine various methods advocated in legal theory as a means to ensure a coherent protection of human rights in Europe in the absence of an institutional agreement. The authors focus their attention on the further development of autonomous concepts in the case law of two the European supranational courts as a prerequisite for successful application of the status quo method. The principle of ne bis in idem is selected as a case in point. Finally, authors formulate proposals for approaches regarding autonomous concepts to be utilized by the Court of Justice and the European Court of Human Rights.Proces pristupanja Evropske unije Evropskoj konvenciji o ljudskim pravima nedavno je ponovo pokrenut. Ipak, u pravnoj nauci se pravilno ukazuje da se radi o komplikovanom i dugotrajnom procesu, dok, sa druge strane, praksa nadnacionalnih evropskih sudova nije međusobno usklađena i u nekim slučajevima za posledicu ima smanjenje obima zaštite ljudskih prava u Evropi. Otuda se javlja potreba da se već sada ispitanju druga rešenja koja mogu doprineti smanjenju neželjenih posledica dugotrajnog pristupanja Evropske unije pomenutoj Konvenciji i doprineti doslednoj i delotvornoj zaštiti ljudskih prava u Evropi. Koristeći se uglavnom dogmatskim metodom, autorke ispituju različite metode predložene u pravnoj teoriji (i primenjene u praksi) sa stanovišta njihovog potencijala da doprinesu delotvornoj zaštiti ljudskih prava, u odsustvu institucionalnih veza između Suda pravde Evropske unije i Evropskog suda za ljudska prava. Autorke potom ukazuju na potrebu da, u primeni metoda zadržavanja statusa quo, koji se trenutno čini najcelishodnijim, dva evropska nadnacionalna suda pribegnu unapređenoj primeni koncepta autonomnih pojmova. One tu potrebu zatim i ilustruju kroz prikaz novije sudske prakse dva navedena suda u odnosu na princip ne bis in idem. U zaključnom delu rada autorke formulišu predloge za unapređenje pristupa Suda pravde Evropske unije i Evropskog suda za ljudska prava u razvijanju i formulisanju autonomnih pojmova, u cilju postizanja delotvorne zaštite ljudskih prava u Evropi i pre nego što Evropska unija pristupi Evropskoj konvenciji o ljudskim pravima