Dark Matter production from two evaporating Primordial Black Holes

Particulate Dark Matter (DM), completely isolated from the Standard Model particle sector, can be produced in the early universe from Primordial Black Hole (PBH) evaporation. However, Big Bang Nucleosynthesis (BBN) observations put an upper bound on the initial mass of PBH requiring the PBH to evaporate completely before the advent of BBN. DM particles in the mass range $\sim(1-10^9)$ GeV can not explain the observed relic abundance for an early matter dominated universe due to this BBN constraint. However, this assumes the presence of only one PBH in the early universe. In this work, we explore the simple possibility of achieving the observed relic with DM masses from the above mentioned range for an early matter dominated era with two evaporating PBHs and demonstrate that the BBN constraints can be alleviated to a good degree.Comment: 8 pages, 5 figure

Thwarting endogenous stress: BRCA protects against aldehyde toxicity

Homologous recombination (HR) and the Fanconi Anemia (FA) pathways constitute essential repair pathways for DNA damage, which includes DNA double-stranded breaks (DSB) and inter-strand cross-links (ICL), respectively. Germline mutations affecting a single copy of the HR factors BRCA1 and BRCA2 predispose individuals to cancers of the breast, ovary, prostate, and pancreas. Cells deficient for BRCA proteins display high levels of genome instability due to defective repair of endogenous DSBs and are also exquisitely sensitive to DNA-damaging agents. In addition to their roles in repair of DSBs and ICLs, HR and FA proteins have a genetically separable function in the protection of stalled DNA replication forks from nuclease-mediated degradation (Schlacher et al, ). Although it has been hypothesized that loss of functional HR and ICL repair is the primary cause of cancer in BRCA- and FA-deficient patients (Prakash et al, ), the contribution of replication fork instability associated with the degradation of nascent DNA remains unclear. Two recent papers explain how endogenous toxins render cells vulnerable to genomic instability, which explains how the BRCA/FA pathway suppresses tumorigenesis (Tacconi et al, ; Tan et al, )

Dark Matter from Evaporating PBH dominated in the Early Universe

Primordial Black Holes (PBH) could dominate in the early universe and, evaporating before Big bang Nucleosynthesis, can provide new freeze in mechanism of dark matter (DM) production. The proposed scenario is considered for two possible mechanisms of PBH formation and the corresponding continuous PBH mass spectra so that the effect of non-single PBH mass spectrum is taken into account in the results of PBH evaporation, by which PBH dominance in the early universe ends. We specify the conditions under which the proposed scenario can explain production of dark matter in very early Universe.Comment: 21 pages; 6 figure

Evaluation of a novel 3-pipe solution for hydronic heat distribution in passive-house standard apartment buildings

The energy efficiency of new buildings in Norway has been steadily improved over the last decades, but with less heating, hydronic heating systems have adversely increased in price. Lessening electric power consumption in new buildings is an important part of the government’s plan to de-carbonize, in which hydronic heating is a suitable alternative for direct electric heating. In this regard, a developer claimed to have found a potential cost-efficient hydronic solution in terms of investment cost. This solution is based on two measures, using the Domestic Hot Water (DHW) circulation loop to cover both DHW demand as well as space heating demand in the building, and significantly reducing the number of heat emitters. In this work, we studied the possible benefits and the issues associated with this solution and performed an analysis based on the following accounts, i) the distribution system, ii) indoor climate, iii) energy demand/consumption, iv) hygienic security. A newly finished apartment complex located in central Oslo is chosen for this purpose. Two apartments and the central heating are examined by inspection, experimental measurements, and Computational Fluid Dynamics (CFD) simulations. The distribution system is examined to confirm the alleged cost efficiency with a simplified cost calculation based on the BIM-model and the documentation provided by the developers. We estimated an additional cost of 67 NOK per square meter in comparison to direct electrical heating. The end user could also financially benefit from using less expensive district heating. Using fan-coils as main heat emitter in each apartment was found to produce satisfactory indoor climate, however, in one apartment it was found that poor planning sabotaged its intended function which negatively affected indoor climate. Additionally, we found a lack of measures to protect the DHW from Legionella-growth, which is a violation of Norwegian building code TEK17.publishedVersio

Cooking emissions from typical Norwegian meals: basis for advanced exposure studies

Sustainable urban dwellings are built space-efficient, and open-plan kitchens have increasingly become the norm. A study of newer building projects has shown that the kitchen space is in the inner area of the apartment with limited options for forced window airing, leaving the job of removing cooking emissions to the kitchen hood or general ventilation. One of the aims of our study is to measure exposure from actual cooking in modern apartments, as preparations for further advanced studies. To achieve this, particle number concentrations (>0.3 μm) are measured for three typical Norwegian meals with different ventilation rates at three locations in the kitchen lab. The kitchen setup is comparable to the EN 61591:2019 standard with an area of approximately 30 m2 and a height of 2.7 m. The measurements show that the meals and cooking procedures developed are reasonably repeatable. Most of the particles are in the range 0.3-2.5 μm. The meal producing the lowest numbers of particles is the vegetarian pasta Bolognese, while taco and fried salmon which required both higher cooking temperature and contained more fat resulted in a much higher number of particles. The peak for particle number concentration was more than 40% lower for the vegetarian meal. Turning on the kitchen hood at medium setting (286 m3/h) drastically reduced the particle number concentrations, however, the Norwegian requirement of 108 m3/h (low) resulted in a 58% reduction for the taco meal.publishedVersio

Cooking habits and usage of kitchen hoods in Norwegian homes

Sustainable urban development results in more space and energy-efficient apartments. Open plan solutions are becoming more common, and the market is exploring new configurations and ventilation solutions for the kitchen in direction of the design and minimize space for ductwork. Cooking is an important aspect of human life and is considered one of the major sources of particle emissions. The cooking method, the type of cuisine, and the type of kitchen hood are some of the factors that will influence this. In Norway, the minimum requirement for general kitchen exhaust is 36 m3/h, with a minimum additional forced ventilation by the kitchen hood of 108 m3/h. However, these requirements might not be sufficient to mitigate the exposure from cooking. Electricity is the main heating source, traditionally with hot plate, today mainly induction or ceramic cooktop. In this work, we aim to investigate representative Norwegian cooking habits, typical meals and set up a procedure for cooking in the laboratory to perform intensive exposure studies. A survey has been performed to identify the type and usage of kitchen hoods in different living situations as well as typical Norwegian meals. A total of 336 people responded to the survey, of which 111 provided answers to a few additional questions. More than 60% of the respondents belonged in the age groups 30 – 60 years old and 92% owned their dwelling. Wall-mounted kitchen hoods were found in the majority of the homes, and almost 4% had downdraft. Only 12% of the homes had recirculating hoods. 76% of the respondents used the kitchen hood during cooking. The Norwegians mainly cook or fry their food, while deep-frying is not common. For the question related to what meal is most often cooked, the categories of food that were most mentioned were pasta dishes, taco, meat, fish, boiled potatoes, and chicken. Based on this we developed the cooking procedure for three different test meals suitable for exposure studies.publishedVersio

Editorial: Impact of genome instability on human health

Genomic instability, characterized by alterations in DNA structure and function, has emerged as a crucial factor influencing human health and disease. In recent years, a growing body of research has focused on unraveling the intricate relationship between genomic instability and its impact on various conditions such as cancer, aging, and genetic disorders, which are reviewed here (Abugable et al., 2019; Tiwari and Wilson, 2019; Nelson and Dizdaroglu, 2020; Yousefzadeh et al., 2021). This editorial presents a synthesis of four recently published articles in Frontiers in Molecular Biosciences that delve into the mechanisms and consequences of genomic instability in different contexts. These studies underscore the role of homologous recombination deficiency in epithelial ovarian cancer, the modulation of a transcription factor in the pathogenesis of breast cancer, the epigenetic landscape of Klinefelter syndrome, and the immunomodulatory effect of PARP inhibitors (PARPi) against cancer. Together, these findings contribute to our understanding of genomic instability and pave the way for improved diagnostics, targeted therapies, and interventions to improve human health