Seasonal dynamics of marine snow‐associated and free‐living demethylating bacterial communities in the coastal northern Adriatic Sea

The extent of DMSP demethylation has been hypothesized to depend on DMSP availability and bacterial sulfur demand, which might lead to niche differentiation of the demethylating bacterial community. In this study, we determined DMSP concentrations in marine snow and the ambient water over a seasonal cycle and linked DMSP concentrations to the abundance of bacteria harboring the demethylation dmdA gene in the Adriatic Sea. In marine snow, DMSP concentrations were up to four times higher than in the ambient water and three times higher in marine snow in summer than in winter. The average dmdA:recA gene ratio over the sampling period was 0.40 ± 0.24 in marine snow and 0.48 ± 0.21 in the ambient water. However, at the subclade level, differences in the demethylating bacterial community of marine snow and the ambient water were apparent. Seasonal patterns of potentially demethylating bacteria were best visible at the oligotype level. In the ambient water, the SAR116 and the OM60/NOR5 clade were composed of oligotypes that correlated to high DMSP concentrations, while oligotypes of the Rhodospirillales correlated to low DMSP concentrations. Our results revealed a pronounced seasonal variability and spatial heterogeneity in DMSP concentrations and the associated demethylating bacterial community

Postdigital citizen science and humanities: dialogue from the ground

Whilst much global research takes place in universities, many researchers in the sciences and humanities do not work within these institutions. Some citizen researchers run their own companies or provide independent consultancy, having left their roles in universities through a conflict of values, where they experienced hostile, hierarchical, or restrictive practices. In a world where many postdigital and biodigital challenges do not sit neatly under one discipline or sector, collaboration with community experts to research potential solutions is crucial, as demonstrated during the Covid-19 pandemic. Universities count knowledge exchange partnerships as a key part of their activities, linked to the United Nations Sustainable Development Goals, yet a closer look at how this works in practice reveals different forms of ‘lockdowns’ that prevent equitable research collaborations. In this collective article, we offer a postdigital perspective on citizen science and humanities research from the ground. This includes a provocation to knowledge-producing institutions via recommendations that emerged from our collective citizen researcher workshop held in Zagreb in Spring 2024. There is now a pressing need to review institutional policies and practices around citizen research, towards more inclusive knowledge exchange partnerships, if we are to collaborate successfully to address many global challenges

Cardiovascular diseases and air pollution in Novi Sad, Serbia

Objectives: A large body of evidence has documented that air pollutants have adverse effect on human health as well as on the environment. The aim of this study was to determine whether there was an association between outdoor concentrations of sulfur dioxide (SO2) and nitrogen dioxide (NO2) and a daily number of hospital admissions due to cardiovascular diseases (CVD) in Novi Sad, Serbia among patients aged above 18. Material and Methods: The investigation was carried out during over a 3-year period (from January 1, 2007 to December 31, 2009) in the area of Novi Sad. The number (N = 10 469) of daily CVD (ICD-10: I00-I99) hospital admissions was collected according to patients' addresses. Daily mean levels of NO2 and SO2, measured in the ambient air of Novi Sad via a network of fixed samplers, have been used to put forward outdoor air pollution. Associations between air pollutants and hospital admissions were firstly analyzed by the use of the linear regression in a single polluted model, and then trough a single and multi-polluted adjusted generalized linear Poisson model. Results: The single polluted model (without confounding factors) indicated that there was a linear increase in the number of hospital admissions due to CVD in relation to the linear increase in concentrations of SO2 (p = 0.015; 95% confidence interval (95% CI): 0.144-1.329, R2 = 0.005) and NO2 (p = 0.007; 95% CI: 0.214-1.361, R2 = 0.007). However, the single and multi-polluted adjusted models revealed that only NO2 was associated with the CVD (p = 0.016, relative risk (RR) = 1.049, 95% CI: 1.009-1.091 and p = 0.022, RR = 1.047, 95% CI: 1.007-1.089, respectively). Conclusions: This study shows a significant positive association between hospital admissions due to CVD and outdoor NO2 concentrations in the area of Novi Sad, Serbia

INDOOR RADON MEASUREMENTS BY NUCLEAR TRACK DETECTORS: APPLICATIONS IN SECONDARY SCHOOLS UDC 53+504.055

Abstract. Indoor radon measurements by nuclear track detectors and application of the method in secondary schools in Serbia were performed in the spring 2004. Thirty detectors (type CR-39) were distributed to high school teachers in several cities in Serbia. After three months of the detectors exposure, they were sent back to the Low-Level Laboratory, Institute of Physics, Belgrade. After exposure, the CR-39 detectors were etched in a 6N NaOH at 70 0 C for 3 hours. The tracks were counted by the semiautomatic track-counting system. The preliminary results are presented in this paper. Key words: Radon, nuclear track detector