Dietary source for skin alkaloids of Dendrobatid poison frogs

Žabe porodice Dendrobatidae sadrže otrovne alkaloide u kožnim žlijezdama. Dugo se smatralo da ih same sintetiziraju, no istraživanjem je dokazano kako su alkaloidi ipak porijeklom od malih člankonožaca kojima se hrane. Vršena su istraživanja koja bi dokazala teoriju o postanku alkaloida iz prehrane. To je uključivalo uzgoj žaba u kavezu u kojemu su vinske mušice bile jedini izvor prehrane. U tim uvjetima pronađeno je vrlo malo alkaloida. Uzgoj u kavezu sa svježim lišćem sakupljenim iz njihovog izvornog staništa, dalo je drugačiji profil alkaloida. Žabe sakupljene iz prirodne okoline, naravno, sadržavale su sve alkaloide koje ta vrsta inače sadrži. No one koje su uzgajane u staklenom terariju, potpuno izolirane od okoline, nisu sadržavale otrovne alkaloide. Ovakav je ishod pokusa bio i za očekivati uz postavljenu hipotezu i prijašnja istraživanja. Žabe ove porodice većim dijelom koriste mrave u prehrani. Istraživanja su uključivala različite vrste ove porodice, a njima se htjela naći poveznica između njih i mrava porodice Formicidae preko raznih spojeva pumiliotoksina koristeći plinsku kromatografiju i masenu sprektrometriju. Istraživanja su pokazala kako mravi rodova Brachymyrmex i Paratrechina sadrže navedene spojeve. Prisutnost pumiliotoksina u ovim mravima, kao i u ekstraktima kože Dendrobates pumilio, zajedno s pronalaskom B. depilis u želucima ovih žaba, definitivno može stajati kao dokaz da ove žabe koriste navedene mrave kao izvor prehrane i pumiliotoksina. Prema dobivenim rezultatima može se zaključiti sljedeće: prisutnost člankonožaca uvjetuje pojavu alkaloida. A njihova koncentracija i raznolikost ovisi o raspoloživosti plijena. Aposemija je pojava za koju se smatra da se razvija zajedno s pojavom otrovnosti, a komparativnim je analizama utvrđena veza između obojenosti i otrovnosti jedinki. Upravo im je ta otrovnost omogućila dnevni način života i bezbrižno kretanje bez brige od napada predatora, a sposobnost sakupljanja otrovnih alkaloida iz organizama kojima se hrane, učinila ih je veoma uspješnom skupinom životinja.Dendrobatid frogs contain a variety of poisonous alkaloids in the skin glands. These alkaloids were initially considered to be synthesized by these frogs, but later studies showed they were actually of dietary origin. There were many research efforts to test the dietary hypothesis. Such work included placing frogs into outdoor cage with a diet of only fruit flies. The occurrence of alkaloids in skin extracts from these captive-raised frogs was very low. Another group of captive-raised frogs placed in outdoor screened cage, but provided with fresh leaf litter gathered from the area where these frogs were common, showed different alkaloid profile. And as expected, wild-caught frogs contained all alkaloids known to that species. Frogs raised in large glass terrarium, isolated entirely from natural surroundings, had no detectable alkaloids in the skin extracts. All of the results were as expected from previous studies and consistent with a given hypothesis. Dendrobatid frogs consume a high proportion of ants as part of their diet in the wild. Using gas chromatographic-mass spectral analysis, many tests were made on a variety of dendrobatid frog species to find a connection between formicine ants and these frogs. That connection was found in the presence of pumiliotoxins in both groups. Pumiliotoxins were detected in ants of the genera Brachymyrmex and Paratrechina. The presence of pumiliotoxins in these ants as well as in skin extracts of the dendrobatid frog Dendrobates pumilio, coupled with the presence of these ants in stomach contents of Dendrobates pumilio, strongly suggests that these ants represent a dietary source for pumiliotoxins in these populations of frogs. Based on results of all research it can be said that arthropods are the source of poison alkaloids in dendrobatid frogs and that their amount and variety is determined only by the availability of those arthropods in their environment. A comparative approach was used to test a prediction of the hypothesis of aposematism: coloration will evolve in tandem with toxicity. And it's the combination of two that allows them to have a diurnal lifestyle and to live carelessly, freed from any fear of predation. This made them to be very successful and well adapted species

О спрези музичко-реторичких стратегија и маријанске топике/топоса у ренесансним мотетима

The text summarizes some of the research results from my doctoral dissertation. In the broadest sense, the following text discusses the influence of rhetorical concepts and practices on the composition practice of the Renaissance. The methodological approach is interdisciplinary and multilayered, and it leads to the interpretation of Marian motifs dating from the late fifteenth to the end of the sixteenth century, in the context of rhetorical ideas and principles, and the Marian topic / topos. The most significant result of this text is the formation of a special analytical method by which the interpretive-contextual reading of musical marking is achieved.У тексту су приказани неки од истраживачких резултата из моје докторске дисертације. У најширем смислу, на овом месту је размотрен утицај реторичких концепата и поступака на композициону праксу ренесансе. Методолошки приступ је интердисциплинаран и вишеслојан, и води ка интерпретацији маријанских мотета насталих од краја XV до краја XVI века, у контексту реторичких идеја и принципа, и маријанске топике/топоса. Најзначајнији резултат овога рада јесте формирање посебне аналитичке методе којом се остварује интерпретативно-контекстуално читање музичких узначавања.Овим радом се истражује однос реторике и музике у ренесансној култури и музичкој пракси. Мотив за ово истраживање налази се у чињеници да постоји мали број студија које се, из овог аспекта, баве композицијама насталим од краја XV до краја XVI века, а које за текстуални предложак имају религиозне химне посвећене Девици Марији. Такође, ниједна од њих се не заснива на испитивању везе између интервалског контрапункта, (музичке) реторике и маријанске топике/топоса. Према споју различитих метода, аналитички приступ примењен у овом раду оригналан је и настао је сумирањем историјско-теоријских сазнања и аналитичког искуства заснованог на великом броју мотета. Сачињен је од мреже различитих аналитичких алата, почевши од музичко-реторичких и контрапунктских, преко маријанских категорија и мотива, до елемената доктрине о религијским афектима. Осмишљена је и примењена нарочита класификација контрапунктског и музичко-реторичког оруђа. У истраживању се полази од претпоставки да музика ренесансне полифоније поседује и изражава значења, да је музичко значење поникло на реторичком концепту истинске елоквенције, те да је кључну улогу у развоју музичке елоквенције имала техника интервалског контрапункта. Такође, претпоставка је да су музичка експресивна средства рационализована у XVII веку као Figurenlehre и Affektenlehre теоријски зачета још у XVI веку. Истраживањем се дошло не само до потврде наведених претпоставки већ и до сазнања да Марија није имала статус жене-ратнице, нити понизне слушкиње која је у сенци Христа, већ је у култури и религији ренесансе препозната као мирна, достојанствена, стамена, мудра и надасве емпатична жена

Dysregulation of the immune system in chronic kidney disease and the impact on disease manifestations and co-morbidity

Background: Chronic kidney disease (CKD) is associated with an increased risk of cardiovascular disease and infections. Both conditions share the same underlying cause comprising of changes in innate and adaptive immunity. Aim: The objective of this thesis was to contribute to an increased understanding of the dysregulation in the immune system in CKD and to evaluate if selected markers can add prognostic information about the presence of vascular changes and infection outcomes in CKD. Methods: In study I, we phenotyped subsets of monocytes, B and T cells in patients with IgA nephropathy (IgAN) using flow cytometry. We included a disease control group (patients with autosomal dominant polycystic kidney disease (ADPKD)) and healthy controls (HC). Cytokines were analyzed using ELISA. In study II, we measured levels of IgE anti double-stranded DNA (dsDNA) in patients with active lupus nephritis (LN), patients with a history of LN, SLE patients with no kidney involvement and population-based controls. Levels of IgE anti-dsDNA were measured using fluorescence enzyme immunoassay. In a subgroup of patients with active LN and healthy controls, we evaluated the effect of active LN serum on healthy donor granulocytes compared to control sera. Granulocytes were stained for markers involved in cell migration, adhesion and immune modulation and were analyzed by flow cytometry. In study III, affinity proteomics was used to detect potential biomarkers for early vascular changes in patients with CKD stages 2-3. Three proteins of interest, potentially involved in vascular lesions, were identified and further analyzed with Luminex. Vascular status was evaluated using ankle-brachial index (ABI) and carotid media-intima thickness (CIMT). In study IV, we evaluated monocyte related markers in relation to kidney function and mortality in hospitalized patients with COVID-19 infection. As controls we included healthy individuals and patients with CKD without infection. Results: In study I, we demonstrated that patients with IgAN, compared to HC, had an altered balance in B cell subsets, changed balance between B and T cells and an increased proportion of CD19- long-lived plasma cells. Compared to both control groups, patients with IgAN had an increased proportion of non-classical monocytes. We showed an association between sCD40L and MCP-1 levels and urine albumin/creatinine ratio in IgAN. In study II, we found higher levels of IgE antidsDNA in active LN compared to controls. Other lupus groups did not differ from controls. We also showed that SLE patients with low complement component 3 (C3) levels, as compared to SLE patients with normal C3, had higher levels of IgE anti-dsDNA. We were also able to demonstrate that sera from active LN had a different impact on the phenotype profile of human basophils, neutrophils and eosinophils. In study III, comparing the two CKD groups at baseline with healthy controls, higher levels of sCD14, ANG and OPG were observed in both CKD groups. After 5 years, of followup, sCD14 and ANG remained higher in CKD stages 2-3 compared to healthy controls. Also, at 5th year of follow-up, a positive correlation was seen between levels of OPG and ABI and between sCD14 and ABI. In study IV, we showed that COVID-19 patient who died during hospital stay, as compared to those who survived, were more often in CKD stages 3-5 and had higher levels of IL-6 and MIP-1α. In addition, we demonstrated that levels of MCP-1 and MIP-1α provided additional prognostic information about hospital survival in patients with COVID-19, with either normal or impaired kidney function. Conclusions: In IgAN, an altered immunological B cell phenotype appears to be mediated by a changed balance between B and T cell subsets, rather than cytokines levels affecting B cell survival, implying the importance of T cell dependent B cell maturation. Determining B cell subsets might be of importance, particularly in terms of number of long-lived B cells, which cannot be targeted through anti-CD20 treatment. Elevated levels of IgE anti-dsDNA in active LN, but not in other lupus groups, reflect a broader autoreactive mechanism extending the immunological disturbances in LN to also engage IgEdependent pathways. Serological factors in serum from active LN can moderate granulocyte phenotype implying immunological disturbances in innate immunity during LN flares. Elevated levels of sCD14 and OPG in patients with CKD stages 2-3 are associated with ABI, as a non-invasive measure of arterial stiffness. This implies the use of sCD14 and OPG as possible biomarkers of vascular lesions even at early stages of CKD. If they can be used as prognostic, or as a possible target for future therapeutic approach warrants further studies. Patients with COVID-19 who died in the hospital, as compared to patients who survived, were more often in CKD stages 3-5 and had higher levels of MIP-1α and IL-6. Levels of MCP-1 and MIP1α provide additional prognostic information in hospitalized patients with COVID-19, and this is valid both for patients with normal and impaired kidney function

Fostering Maritime Innovations Th rough Human Capital: Exploring the Status Quo of the Adriatic Universities

The purpose of the paper is to emphasize the need for enhancing participation of the Adriatic maritime universities and researchers in modern innovation processes in maritime industry. The paper primarily analyses human capital in regard to two constituent components - academic (academic rank and the length of research experience) and collaborative (expertise in innovation projects, the frequency of participation, the constraints related to partnerships and funds). The research is based on quantitative and qualitative analysis. The dependence between the components associated with human capital is quantitatively determined by means of the Pearson\u27s chi-square test and the R programme. The qualitative analysis relies on coding of the attitudes of the maritime researchers about collaborative innovations in maritime industry. The coding was performed by means of the Atlas.ti 8.4.24. programme. Results confirm the significance of human capital for maritime research, identify constraints on the realization of innovations and specific innovations the maritime researchers are working on. Additionally, the paper detected the lack of strategic transformation of the universities that would strengthen collaborative innovations in maritime industry. The paper proposes formation of collaborative network/platform for an efficient use of human capital in scientific research and maritime and economic integrations in the Adriatic region

An Interview with Ghassan Hage

Ghassan Hage is Future Generation Professor of Anthropology and Social Theory at the University of Melbourne. He is a Fellow of the Australian Academy of the Humanities and the Australian Academy of the Social Sciences. His main research interest is in the anthropology of viability (in asking what viability can add to an analytical anthropological perspective), and he has published widely on the comparative anthropology of racism, nationalism, multiculturalism and migration. His early research work has centred on the experience of nationalism, racism and multiculturalism among White Australians. Senka Božić-Vrbančić interviewed Ghassan Hage for Etnološka tribina in June 2020