Carbon footprint at institutions of higher education:the case of the University of Oulu

Abstract As an answer to the need to reduce greenhouse gas emissions, organizations are increasingly making efforts to account for their carbon footprint. While general guidelines for carbon footprint calculation exist, they usually do not consider special characteristics of organisations such as institutions of higher education. Case studies can act then as learning tools, and comparisons between applied methodologies can be used to develop best practices. However, a lack of case studies published in peerreviewed journals limits access to the calculation results. This work provides a case study for a Northern European institution to extend the pool of available calculation methodologies tested under real-life conditions. The carbon footprint calculation of the University of Oulu utilises a hybrid model, combining approaches of Environmentally Extended Input-Output Analysis and Life-Cycle Assessment. The focus of the work was to consider included scopes and categories of emissions that represent indirect and non-energy-related greenhouse gas emissions, such as commuting or procurement of research and laboratory equipment. In 2019, the institution’s emission inventory sums up to 19,072 t CO2e, with the highest share due to the use of district heat on campus. Another goal of conducting this research was to show the limitations researchers might encounter when analysing caused emissions on an organisational level, and how the calculated carbon footprint can help to identify the best mitigation measures and possibilities for universities to reach carbon neutrality. It was found that the availability of information and missing strategies for data collection are prominent limiting factors. Favourable mitigation measures include the implementation of energysaving policies and improved policies for procurements

Osteoclasts secrete osteopontin into resorption lacunae during bone resorption

Abstract Osteopontin (OPN) is a non-collagenous extracellular sialylated glycoprotein located in bone. It is believed to be one of the key components in osteoclast attachment to bone during resorption. In this study, we characterized OPN and other glycoproteins found in the resorption lacunae to confirm the role of osteoclasts in OPN secretion using electron microscopy and mass spectrometry. Additionally, we examined the glycan epitopes of resorption pits and the effects of different glycan epitopes on the differentiation and function of osteoclasts. Osteoarthritic femoral heads were examined by immunohistochemistry to reveal the presence of OPN in areas of increased bone metabolism in vivo. Our results demonstrate that human osteoclasts secrete OPN into resorption lacunae on native human bone and on carbonated hydroxyapatite devoid of natural OPN. OPN is associated with an elevated bone turnover in osteoarthritic bone under experimental conditions. Our data further confirm that osteoclasts secrete OPN into the resorption pit where it may function as a chemokine for subsequent bone formation. We show that α2,3- and α2,6-linked sialic acids have a role in the process of osteoclast differentiation. OPN is one of the proteins that has both of the above sialic residues, hence we propose that de-sialylation can effect osteoclast differentiation in bone