Epidemiology and clinical characteristics of paediatric bloodstream infections 1998-2018 in Stockholm

Bloodstream infections (BSI) constitute a common, serious, and potentially preventable cause of morbidity and mortality in children. Good knowledge of epidemiology, aetiology and the occurrence of antimicrobial resistance is essential for early effective empiric antibiotic therapy. Also, to identify areas for improved antimicrobial therapy and possible preventive measurements for BSI in different risk groups. The general aims of this thesis were to describe the aetiology, risk factors, and occurrence of bacteria resistant to antimicrobial therapy in children aged 0–17 years, with BSI under 20 years. In papers I, II and IV, we found a crude BSI incidence rate of 25.5/100,000 children, aged 0-17 years, over the study period, with differences between different ages and risk groups. From 15/100,000 in children, aged 3–17 years to 180/100,000 live births at neonatal wards (children 0–2 months), but 40/100,000 for 0–2 month-old children warded outside neonatal wards. Over the study period different strategies to prevent BSI attributed to a decreased risk for BSI. Introduction of vaccine against Streptococcus pneumoniae declined the incidence of BSI with 30% in children aged between 3 months and 2 years. Implementation of a a risk-based intrapartal antibiotic prophylax program against early onset Streptococcus agalactiae BSI had most impact to reduce the incidende in new-borns. BSI in children without underlying co-morbidities has become rare and are caused by a limited numer of pathogens. In children with cancer, underlying co-morbidities and neonates warded at the neonatal wards the aetioloogy is much more diversed. S. aureus was the most prevalent pathogen. In paper III, we studied the antibiotic prescription, and concluded a changing pattern in the prescription of antimicrobial therapy, with a proportional decrease in the treatment of community-acquired infections and an increase in prophylactic therapy to specific risk groups of patients. In paper V, we found acquired antimicrobial resistance (AMR) in 9.2% of all invasive isolates. The trend for AMR increase for both Gram-positives and Gram-negative bacteria. The proportion of Enterobacterales producing extended-spectrum beta-lactamases (ESBL) increased from 1.6% to 14.1%. A high proportion (64.7%) of ESBL-producing strains was multidrug-resistant. During the last period, 6% of S. aureus were MRSA (methicillin-resistant Staphylococcus aureus). The oncology patient group had the highest proportion of ESBL-producing Enterobacterales. A history of travel in the past six months to a non-Nordic country by the child or a household member was identified as a risk factor. In conclusion, the thesis adds knowledge about the aetiology and epidemiology of BSI in children from a Swedish perspective. The findings are highly important for designing empiric antibiotic therapy regimes and for planning targeted measurements to improve therapy and prevent BSI

Urinary incontinence related to perineal muscle strength in the first trimester of pregnancy: cross-sectional study

Objective To analyze pelvic floor muscle strength (PFMS), urinary continence and quality of life related to urinary incontinence (UI) of women in the first trimester of pregnancy. Method Cross-sectional study with a sample of 500 women who started prenatal care in a complementary healthcare facility in Guarulhos, state of São Paulo, from 2012 and 2013. Pelvic floor muscle strength was evaluated through perineometry. The pregnant women who presented UI answered the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF). Results It was found that maternal age (OR=1.06; CI95% 1.02-1.11) and prior UI (OR=15.12; 95%CI 8.19-27.92) are the variables that, in tandem, best explain the occurrence of UI at the beginning of pregnancy. The mean score on the ICIQ-SF was 8.2 (SD=3.9), considered a moderate impact on quality of life. Conclusion Older pregnant women with prior UI are more likely to have UI in the first trimester of pregnancy.
</jats:p

The potential for peak shaving on low voltage distribution networks using electricity storage

Co-location of energy storage with demand provides several benefits over other locations, while still being able to provide balancing services to the grid. One of these additional benefits is deferral of distribution infrastructure reinforcement, allowing increased load growth. This paper considers the potential of electricity storage for peak shaving on distribution networks, focusing on residential areas. A demand model is used to synthesise high resolution domestic load profiles, and these are used within Monte Carlo analysis to determine how much peak shaving could be achieved with storage. An efficient method of finding the potential peak shaving using electricity storage is developed for this purpose. It is shown that moderate levels of storage capacity can deliver significant demand reductions, if suitably coordinated and incentivised. With 2 kWh of battery storage per household, the peak demand at low voltage substations could potentially be halved. The effects of PV capacity, household size and C rates are considered. With 3 kW PV per house, 4.5 kWh of batteries could keep peak flows at the same level as before the addition of PV. It is also shown that 3 kWh of battery storage per household could allow provision of all heating from heat pumps without increasing t he peak demand

Improving the feasibility of household and community energy storage : a techno-enviro-economic study for the UK

Rooftop photovoltaics (PV) have become widely adopted by domestic customers in tandem with energy storage systems to generate clean energy and limit import from the grid, however most applications struggle to achieve profitability. The level at which energy storage is deployed, be it household energy storage (HES), or as a community energy storage (CES) system, can potentially increase the economic feasibility. Furthermore, the introduction of a Time-of-Use (TOU) tariff enables households to further reduce their energy costs through demand side management (DSM). Here we investigate and compare the performance of HES and CES with DSM. The results suggest that TOU tariffs can effectively shave peak demand by up to 30% and lower energy bills by at least 20%, but do not improve self-consumption or selfsufficiency rate. This study indicates that all cases considered are environmentally friendly and can pay back the total CO2 emissions associated with the manufacturing within 8 years. However, the levelised cost of storage (LCOS) is still beyond a household’s affordability, ranging from £0.4 to £2.03 kWh-1, though CES is proven more effective at improving self-consumption for consumers and shaving peak demand for network operators. The feasibility can be improved by 1) combining different services and tariffs to obtain more revenues for households; 2) more legislative and financial support to reduce system costs; and 3) more innovative business models and policies to optimise revenues with existing resourc

Egenanvändning av solel i bostadshus

Worldwide installations of photovoltaics (PV) have increased rapidly due to national subsidies and decreasing prices. One important market segment is building-applied PV systems, for which the generated electricity can be self-consumed. Self-consumption is likely to become important both for the profitability and to facilitate integration of high shares of PV in the power system. The purpose of this doctoral thesis is to examine opportunities and challenges with distributed PV in the power system on four system levels: detached houses, communities, distribution systems and national level. This was done through literature studies and computer simulations. Previous research has shown a larger potential to increase the PV self-consumption in detached houses by using battery storage rather than shifting the household appliance loads. This thesis shows that, on the community level, the self-consumption increased more when sharing one large storage instead of individual storages in each house. On the distribution system level, PV power curtailment was identified as an effective solution to reduce the risk of overvoltage due to high PV penetration levels. However, the curtailment losses were high: up to 28% of the electricity production had to be curtailed in the studied distribution grid with a PV penetration of 100% of the yearly electricity consumption. However, the penetration of distributed PV on a national level is not likely to reach these levels. Around 12% of the Swedish households were estimated to have PV systems in 2040, although the uncertainties in the results were high, mainly related to the development of the electricity prices. The low profits from both PV but especially battery systems reduce future market shares. If residential batteries could also be used for primary frequency control, the profitability and thus the market shares for PV and battery systems could increase. The overall conclusions are that improved self-consumption can increase the profitability of PV systems and lower the negative impacts on grids with high PV penetration. Energy storage has a large potential to increase the self-consumption, but the profitability is still low for a storage that is only used to increase the self-consumption.    

Egenanvändning av solel i bostadshus

Worldwide installations of photovoltaics (PV) have increased rapidly due to national subsidies and decreasing prices. One important market segment is building-applied PV systems, for which the generated electricity can be self-consumed. Self-consumption is likely to become important both for the profitability and to facilitate integration of high shares of PV in the power system. The purpose of this doctoral thesis is to examine opportunities and challenges with distributed PV in the power system on four system levels: detached houses, communities, distribution systems and national level. This was done through literature studies and computer simulations. Previous research has shown a larger potential to increase the PV self-consumption in detached houses by using battery storage rather than shifting the household appliance loads. This thesis shows that, on the community level, the self-consumption increased more when sharing one large storage instead of individual storages in each house. On the distribution system level, PV power curtailment was identified as an effective solution to reduce the risk of overvoltage due to high PV penetration levels. However, the curtailment losses were high: up to 28% of the electricity production had to be curtailed in the studied distribution grid with a PV penetration of 100% of the yearly electricity consumption. However, the penetration of distributed PV on a national level is not likely to reach these levels. Around 12% of the Swedish households were estimated to have PV systems in 2040, although the uncertainties in the results were high, mainly related to the development of the electricity prices. The low profits from both PV but especially battery systems reduce future market shares. If residential batteries could also be used for primary frequency control, the profitability and thus the market shares for PV and battery systems could increase. The overall conclusions are that improved self-consumption can increase the profitability of PV systems and lower the negative impacts on grids with high PV penetration. Energy storage has a large potential to increase the self-consumption, but the profitability is still low for a storage that is only used to increase the self-consumption.    

Miracle crop or societal burden? : A political ecology analysis of the relationship between Swedish society and industrial hemp (Cannabis Sativa L.)

The agricultural sector plays a crucial role in securing a more sustainable livelihood for the world's growing population. An expanded cultivation of multifunctional and environmentally smart crops like industrial hemp (Cannabis sativa L.) can thus be part of the solution in meeting the increasingly high demands of sustainable development. However, earlier research indicates that the global cultivation of industrial hemp is hindered, and that hemp is an underutilized resource relative to its potential benefits. During the 20th century hemp cultivation was banned in large parts of the world. Sweden lifted the ban in 2003, later than most other European countries. In 2017, Swedish hemp cultivation was by far one of the smallest in the European Union. This study thus aims to analyze the position of industrial hemp in Sweden – by using the theoretical framework of political ecology – to investigate which social and societal structures and processes that dictates the access to and the control of industrial hemp in Sweden today. A historical analysis of power relations as well as ideological and cultural contexts – with significance for the cultivation of hemp – is done to make the relationship between Cannabis sativa L. and Swedish society appear more clearly. The material for the analysis has been collected through a literature search and qualitative method using in-depth interviews with Swedish authorities and a national hemp association. The study discusses the relationship between hemp and human society, which is found to be characterized by a complex interconnectedness.  Furthermore, the study shows that Swedish industrial hemp production is negatively affected by, among other things, cultivation bans, strict regulations, government controls, drug conservatism, and group as well as state conformity. Through a more progressive policy, industrial hemp is expected to become a positive contributing factor to reduced greenhouse gas emissions and to a growing fossil-free bio-based industry.

Improved Self-Consumption of Photovoltaic Electricity in Buildings : Storage, Curtailment and Grid Simulations

The global market for photovoltaics (PV) has increased rapidly: during 2014, 44 times more was installed than in 2004, partly due to a price reduction of 60-70% during the same time period. Economic support schemes that were needed to make PV competitive on the electricity market have gradually decreased and self-consumption of PV electricity is becoming more interesting internationally from an economic perspective. This licentiate thesis investigates self-consumption of residential PV electricity and how more PV power can be allowed in and injected into a distribution grid. A model was developed for PV panels in various orientations and showed a better relative load matching with east-west-oriented compared to south-oriented PV panels. However, the yearly electricity production for the east-west-system decreased, which resulted in less self-consumed electricity. Alternatives for self-consumption of PV electricity and reduced feed-in power in a community of detached houses were investigated. The self-consumption increased more with shared batteries than with individual batteries with identical total storage capacity. A 50% reduction in feed-in power leads to losses below 10% due to PV power curtailment. Methodologies for overvoltage prevention in a distribution grid with a high share of PV power production were developed. Simulations with a case with 42% of the yearly electricity demand from PV showed promising results for preventing overvoltage using centralized battery storage and PV power curtailment. These results show potential for increasing the self-consumption of residential PV electricity with storage and to reduce stress on a distribution grid with storage and power curtailment. Increased self-consumption with storage is however not profitable in Sweden today, and 42% of the electricity from PV is far more than the actual contribution of 0.06% to the total electricity production in Sweden in 2014

Photovoltaic System Layout for Optimized Self-Consumption

Most of the photovoltaic (solar cell) systems in Sweden today are installed on private houses and connected to the public grid. Photovoltaic (PV) power can be consumed directly in the house, called self-consumption, or fed in to the public grid. For the house owner self-consumed PV energy often has a higher economic value than sold excess PV energy, since the savings from not buying one kWh is larger than the income of selling one kWh. The self-consumption can be expressed as an absolute value; amount of produced/consumed kWh, or as a relative; absolute self-consumption divided with total PV production. The PV production and self-consumption were calculated on an hourly basis. In this Master thesis a MATLAB tool for calculating and optimizing the production, absolute and relative self-consumption and profit for PV systems with panels in one (1DPV), two or three directions (3DPV) was developed. The results show possibilities to increase especially the relative self-consumption with 3DPV. There is however no economic gain of using 3DPV instead of south-directed 1DPV for the studied case; a private house close to Västerås with a 1DPV system of 3360 W and variable electricity prices based on hourly Nord Pool Spot prices. The rated power of the inverter can be decreased with 3DPV compared to south-oriented 1DPV and still keep minimal production losses. A smaller inverter and other peripheral equipment such as cables might compensate for the lower yearly profit with 3DPV when calculating the payback period. Further studies of economic aspects and how to optimize them have to be carried out for 3DPV systems, since economy is very crucial for investment decisions