Season In Sweden Research Articles

School holidays and respiratory syncytial virus transmission in Sweden: An interrupted time series analysis.

Respiratory syncytial virus (RSV) represents a significant cause of morbidity for children worldwide, especially for newborns. As RSV vaccines are not routinely used for children yet, non-pharmaceutical interventions (NPIs) represent the main strategy for prevention. The objective of this study was to investigate the correlation between school holidays and RSV transmission. Data were collected from the weekly reports on RSV incidence for the 2021/2022 and 2022/2023 seasons in Sweden. The 7-day cumulative incidence of RSV was compared before and after the designated school holidays (Fall, Christmas, and Winter holidays). Our findings reveal an immediate (-1.7%, p < 0.001, 95% CI [-3.1%, -0.4%]) and gradual (-1.4%/week, p < 0.001, 95%CI [-1.8, -1.0]) reduction in RSV incidence following the Fall holiday in 2021, especially among children under 1 year of age, both immediately (-107.6%, p < 0.05, 95% CI [-203.7, -11.5]) and gradually afterwards (-58.5%/week, p < 0.001, 95% CI [-72.7, -44.3]). Mixed results were obtained for the Fall in 2022/2023 and for the Winter and holidays in both the studied years. While the Fall holiday in 2021/2022 was associated with a decrease in RSV incidence in Sweden, our results do not support a universal effect of school holidays on reducing RSV transmission.

Negotiating the city during the dark season: a study of recreational running

Seasonality plays an important role in determining how and where everyday activities are conducted. Yet how seasonality shapes recreational mobilities in the city, and how it matters for everyday urban life, remain largely unexplored. Inspired by recent research on the weather as lived, this paper contributes to the understanding of urban recreational mobilities as shaped by runners negotiating the urban environment and its seasonality. Thereby, we also explore a specific way to examine the city. We studied recreational running during the dark season in Sweden, based on diary-interviews with thirty runners, employing practice theory and affordance theory to explore how places, practices, and affordances characterize running during this season. Our findings reveal ways in which runners engage in different running practices in different settings, with the forest, pavement, and hills as our examples, and with lights as an additional analytical lens. We show how runners, in their strategies for dealing with the dark season in a city, tend to avoid some characteristics of the city (traffic, noise) while taking advantage of others (street illumination, road, and pavement maintenance). Thus, running practices are partly formed by urban planning and maintenance.

Boreal forest soil carbon fluxes one year after a wildfire: Effects of burn severity and management.

The extreme 2018hot drought that affected central and northern Europe led to the worst wildfire season in Sweden in over a century. The Ljusdal fire complex, the largest area burnt that year (8995ha), offered a rare opportunity to quantify the combined impacts of wildfire and post-fire management on Scandinavian boreal forests. We present chamber measurements of soil CO2 and CH4 fluxes, soil microclimate and nutrient content from five Pinus sylvestris sites for the first growing season after the fire. We analysed the effects of three factors on forest soils: burn severity, salvage-logging and stand age. None of these caused significant differences in soil CH4 uptake. Soil respiration, however, declined significantly after a high-severity fire (complete tree mortality) but not after a low-severity fire (no tree mortality), despite substantial losses of the organic layer. Tree root respiration is thus key in determining post-fire soil CO2 emissions and may benefit, along with heterotrophic respiration, from the nutrient pulse after a low-severity fire. Salvage-logging after a high-severity fire had no significant effects on soil carbon fluxes, microclimate or nutrient content compared with leaving the dead trees standing, although differences are expected to emerge in the long term. In contrast, the impact of stand age was substantial: a young burnt stand experienced more extreme microclimate, lower soil nutrient supply and significantly lower soil respiration than a mature burnt stand, due to a thinner organic layer and the decade-long effects of a previous clear-cut and soil scarification. Disturbance history and burn severity are, therefore, important factors for predicting changes in the boreal forest carbon sink after wildfires. The presented short-term effects and ongoing monitoring will provide essential information for sustainable management strategies in response to the increasing risk of wildfire.

Mechanized Tree Planting in Sweden and Finland: Current State and Key Factors for Future Growth

In Fennoscandia, mechanized tree planting is time-efficient and produces high-quality regeneration. However, because of low cost-efficiency, the mechanization of Fennoscandian tree planting has been struggling. To determine key factors for its future growth, we compared the operational, planning, logistical, and organizational characteristics of mechanized planting in Sweden and Finland. Through interviews with planting machine contractors and client company foresters, we establish that mechanized tree planting in Sweden and Finland presently shares more similarities than differences. Some notable differences include typically longer planting seasons in Sweden, and a tendency towards two-shift operation and less frequent worksite pre-inspection by contractors in Finland. Because of similar challenges, mechanized planting in both countries can improve cost-efficiency through education of involved foresters, flexible information systems, efficient seedling logistics, and continued technical development of planting machines. By striving to have multiple client companies, contractors can reduce their operating radii and increase their machine utilization rates. Above all, our results provide international readers with unprecedented detailed and comprehensive figures and characteristics of Swedish and Finnish mechanized tree-planting activities. We conclude that cooperation between Sweden’s and Finland’s forest industries and research institutes could enhance the mechanization level of Fennoscandian tree planting.

Altered Tuber Yield in Genetically Modified High-Amylose and Oil Potato Lines Is Associated With Changed Whole-Plant Nitrogen Economy.

Breeding for improved crop quality traits can affect non-target traits related to growth and resource use, and these effects may vary in different cultivation conditions (e. g., greenhouse vs. field). The objectives of this study are to investigate the growth and whole-plant nitrogen (N) economy of two genetically modified (GM) potato lines compared to their non-GM parental varieties and when grown in different cultivation conditions. A high-amylose GM potato line and its parent were grown under field and greenhouse conditions for one growing season in Sweden; and a GM oil potato line and its parent were grown in greenhouse conditions only. Tuber yield, above ground biomass, N uptake efficiency and other plant N economy traits were assessed. In both cultivation conditions, the GM lines produced between 1.5 and two times more tubers as compared with their parents. In the greenhouse, fresh tuber yield and N uptake efficiency were unaffected by the genetic modifications, but the GM-lines produced less tuber biomass per plant-internal N compared to their parents. In the field, the fresh tuber yield was 40% greater in the high-amylose line as compared with its parent; the greater fresh tuber yield in the high-amylose GM line was accomplished by higher water allocation to the harvested tubers, and associated with increased N recovery from soil (+20%), N uptake efficiency (+53%), tuber N content (+20%), and N accumulation (+120%) compared with the non-GM parent. The cultivation conditions influenced the yield and N economy. For example, the final fresh above-ground plant biomass and N pool were considerably higher in the greenhouse conditions, whilst the tuber yield was higher in the field conditions. In conclusion, the genetic modification inducing high accumulation of amylose in potato tubers affected several non-target traits related to plant N economy, and increased the plant N uptake and accumulation efficiency of the field-grown plants. Due to strongly increased plant N accumulation compared to the parental variety, the cultivation of the high-amylose line is expected to require higher N fertilization rates. However, starch productivity per unit land area or soil N still is expected to be higher in the high-amylose line.

Low-temperature heating in existing Swedish multi-family houses—An assessment of the significance of radiator design and geometry

The current study evaluates the impacts of radiator designs and geometries. The aim was to map the thermal efficiency and performance differences of studied radiator types. A typical Swedish low-rise, multi-family house was selected to present the analysis. A Swedish climate was employed to evaluate the applicability. The on-site measurements, analytical model, and real-life performance data from radiator manufacturing were applied for the modeling work. Radiator Type 21 (1.2 × 0.4 m) showed the highest exergy efficiency; Type 11 (1.2 × 0.45 m), the lowest. There is no evidence that Type 22 (adding more convector plate) has a higher thermal efficiency than Type 21, from an engineering perspective, within the climate range of −20°C to 15°C. Baseboard radiators showed a 34% higher exergy performance than the most efficient conventional radiator, with the same surface area, at mean outdoor temperatures during an average heating season in Sweden (−1.3°C). The results also suggest that Type 21 would have higher efficiency than Type 11 during 50% time of the heating season, in severe climate conditions. In the climate of Stockholm, this efficiency advantage was 20%. For the mild climate, Type 11 and Type 21 performed almost the same over the entire heating season.

“An NHL Touch”: Transnationalizing Ice Hockey in Sweden, 1994–2013

During the 1994-95 ice hockey season in Sweden, one of the teams in the highest division, Luleå, treated fans to an innovation: instead of merely entering the ice as in years past, players flew out of a gigantic bear maw, to the accompaniment of a pounding rock beat. The idea was not original, however; as a newspaper columnist noted, it had been copied directly from the National Hockey league in North America. Luleå’s new entrance concept was part of a concerted effort by teams in Sweden’s highest ice hockey division, Elitserien, to emulate the NHL to make the sport more popular with young fans. This paper examines how and why that attempt was made and why it was ultimately unsuccessful.Using newspaper articles and ice hockey association materials and examining comments made by fans in online fora, the study recounts that the change involved creating an “event” atmosphere around games, making symbols more NHL-like, and adopting names in English. Reaction from both media commentators and fans was clearly negative, mainly because the changes were seen as gimmicks and because they had been imposed on team supporters without prior consultation. In the end, most teams quietly ended the use of both names and symbols.The last point is interesting, the study argues, as it has implications for discussions of Americanization. The case of Swedish hockey in the 1990s suggests that there are instances when American influences are rejected by recipients in other countries.

Modelling atmospheric icing: A comparison between icing calculated with measured meteorological data and NWP data

In this case study several periods of measured active icing events have been compared with calculated active icing. Icing events from three winter seasons in Sweden have been selected as a base for studying how well a commonly used method to calculate icing can capture icing events, as well as to try out a new approach. Another purpose is to enlighten parties interested in atmospheric icing of the challenges of calculating icing. For those with little knowledge of Numerical Weather Prediction (NWP) models it can be hard to understand why there are differences between two models, or even the same model using different physical parameterisation schemes. In this study data from two NWP models have been used to calculate icing, as well as being compared with a new approach using meteorological measurements to calculate icing. Using meteorological measurements to calculate icing is an interesting alternative as it is computationally less expensive than using a NWP model to generate the necessary data.All tested methods could at times capture the dynamics of the measured icing, though there are on occasion large differences between the different calculated icing and also between calculations and measurements. This highlights the importance of having an understanding of NWP models when studying atmospheric icing; there can be a large spread between different models, and also when using the same model with different schemes. The results show that calculated icing is comparable to measured icing and that the methodologies investigated are viable options for calculating atmospheric icing.

Detecting the norovirus season in Sweden using search engine data--meeting the needs of hospital infection control teams.

Norovirus outbreaks severely disrupt healthcare systems. We evaluated whether Websök, an internet-based surveillance system using search engine data, improved norovirus surveillance and response in Sweden. We compared Websök users' characteristics with the general population, cross-correlated weekly Websök searches with laboratory notifications between 2006 and 2013, compared the time Websök and laboratory data crossed the epidemic threshold and surveyed infection control teams about their perception and use of Websök. Users of Websök were not representative of the general population. Websök correlated with laboratory data (b = 0.88-0.89) and gave an earlier signal to the onset of the norovirus season compared with laboratory-based surveillance. 17/21 (81%) infection control teams answered the survey, of which 11 (65%) believed Websök could help with infection control plans. Websök is a low-resource, easily replicable system that detects the norovirus season as reliably as laboratory data, but earlier. Using Websök in routine surveillance can help infection control teams prepare for the yearly norovirus season.

Reactive oxygen species in stallion semen can be affected by season and colloid centrifugation

There are anecdotal reports that equine fertility may decline towards the end of the breeding season. Previous studies have examined differences in sperm quality between the breeding season and non-breeding season but few studies have investigated the proportions of superoxide or peroxide containing spermatozoa at different times during the breeding season. The purpose of this study was to measure the content of these reactive oxygen species (ROS) at the beginning and end of the Swedish breeding season, using flow cytometric analysis of the fluorescence produced after staining with hydroethidium and dichlorodihydrofluorescein diacetate. In addition, the effects of a new method of selecting good quality spermatozoa by colloid centrifugation, known as Single Layer Centrifugation (SLC), on ROS-content were investigated. Superoxide production by stallion spermatozoa was found to be higher at the start than at the end of the breeding season in Sweden (22±16% versus 9±6%, P<0.05), whereas sperm motility was lower (total motility 80±9% versus 90±6%, P<0.01; progressive motility 55±12% versus 60±8%, P<0.05, at the beginning and end of the breeding season respectively). The mean values of the other parameters of sperm quality measured did not differ with time within the breeding season although differences did occur for individual stallions. SLC was found to select motile spermatozoa that contained less superoxide (16±14% versus 23±18%, P<0.01) and less peroxide (0.3±0.8 versus 1±2%, P<0.01) than uncentrifuged controls, although they were capable of producing ROS when stimulated with menadione. This reduced peroxide production may contribute to the enhanced sperm survival (retention of motility) seen in the SLC samples during storage.

Detection of pregnancy in a hibernator based on activity data

Pregnancy and parturition are often difficult to detect in wild-living animals, especially in species that give birth to altricial young in burrows or caves. Current methods to detect pregnancy and birth in hibernating animals often entail disturbances that can affect the animals' reproductive success. We developed a new method to confirm pregnancy and parturition in hibernating brown bears (Ursus arctos) using activity data recorded in dual-axis motion sensors mounted on GPS–GSM neck collars on 30 brown bears during 52 hibernation seasons in Sweden. We adjusted recorded activity to the individual basal activity level for each bear. Pregnant females showed characteristic activity patterns during the period of pregnancy, with significantly higher daily activity levels and frequency of active periods during pregnancy than nonpregnant bears. Pregnant females were active on average 2.20 times more often during the pregnancy period than during the postpartum period, compared with 0.97 times for nonpregnant females. A pregnancy index was defined as the average of the proportion of mean daily activity levels and the proportion of activity events during the pregnancy period compared with the postpartum period. It averaged 2.61 ± 1.73 (SD) for pregnant females and 0.94 ± 0.24 for nonpregnant females. Using this method, we evaluated a group of adult females that had an unverified reproductive status but were classified as not pregnant because no cubs had been observed after den emergence. The results suggested that 35 % of those females had, in fact, been pregnant.

Does vitamin D status impact on hip fracture incidence?: evidence of fracture variation with latitude and season in Sweden

Searchable abstracts of presentations at key conferences on calcified tissues ISSN 2052-1219 (online)

Prevailing effectiveness of the 2009 influenza A(H1N1)pdm09 vaccine during the 2010/11 season in Sweden

Sixty per cent of the Swedish population received the monovalent AS03-adjuvanted pandemic influenza vaccine in the autumn of 2009. We assessed the age-specific effectiveness of this pandemic vaccine against hospitalisation with laboratory-confirmed influenza A(H1N1)pdm09 during the season 2010/11, in the age group from six months to 64 years in Sweden. The screening method was applied to available surveillance data. Our results suggest a prevailing effectiveness of 72% (95% confidence interval (CI): 63–80%) with the highest effectiveness among children, six months to nine years-old (92%, 95%CI: 80–97%). However, there were limitations in data quality and study design due to the lack of systematic recording of administered vaccinations, which underline the importance of preparing for an evaluation when planning for large public health actions. Despite these limitations, we believe the results reflect true, high prevailing vaccine effectiveness. Indeed, there were fewer deaths caused by influenza and the impact of influenza on intensive care units was less severe during the 2010/11 season in Sweden than in countries with lower pandemic vaccination coverage. The association between the pandemic vaccine and narcolepsy has increased the importance of assessing the risks and benefits of the vaccination; studies on the effectiveness and the duration of protection are needed for this.

Eclampsia is more prevalent during the winter season in Sweden

Hypertensive pregnancy conditions have shown seasonal variations and have been related to low levels of vitamin D. In Sweden, the hours of sunlight per day are few in winter. We hypothesized that eclampsia would be more common in the winter season. We performed a population-based cross-sectional study of all singleton deliveries in Sweden during a 5-year period (n= 482,759 women). All parturients with eclampsia were included as cases and those without formed control group. The incidence of eclampsia was nearly doubled during winter season (odds ratio 1.9, 95% confidence interval 1.4-2.6) as compared to other seasons. The incidence of eclampsia during the period studied (1990-1994) was four in 10,000 pregnancies. We found that eclampsia was twice as common in winter and we introduce the alternative hypothesis that lack of sunlight exposure increases women's susceptibility to eclampsia, possibly due to vitamin D insufficiency.

Kleptoparasitism of a Coyote (Canis latrans) by a Golden Eagle (Aquila chrysaetos) in Northwestern Canada

calves in the diet of nesting Golden Eagles in Finnmark, northern Norway. Ornis Fennica 84: 112-118. Kroll AM. 1993. Haul out patterns and behavior of harbor seals, Phoca vitulina, during the breeding season at Protection Island, Washington [thesis]. Seattle, WA: University of Washington, 142 p. norberg H, kojola I, AlKIO P, nylund M. 2006. Predation by Golden Eagle Aquila chrysaetos on semi-domesticated reindeer Rangifer tarandus calves in northeastern Finnish Lapland. Wildlife Biology 12:393-402. Parrish JK, Marvier M, Paine RT. 2001. Direct and indirect effects: Interactions between bald eagles and common murres. Ecological Applications 11: 1858-1869. Sherrod SK, Estes JA, White CM. 1975. Depreda tion of sea otter pups by bald eagles at Amchitka Island, Alaska. Journal of Mammalogy 56:701 703. Sherrod SK, White CM, Williamson FSL. 1976. Bi ology of the bald eagle on Amchitka Island, Alas ka. The Living Bird 15:143-182. skorupa JP. 1989. Crowned Eagles Strephanoaetus co ronatus in rainforest: Observations on breeding chronology and diet at a nest in Uganda. Ibis 131: 294-298. stalmaster M. 1987. The bald eagle. New York, NY: Universe Books. 227 p. thompson SP. 1989. Observations of bald eagles eat ing glaucous-winged gull eggs in western Wash ington. Northwestern Naturalist 70:13-14. Tjernberg M. 1981. Diet of the Golden Eagle Aquila chrysaetos during the breeding season in Sweden. Ecography 4:12-19. Watson JW, Stinson D, McAllister KR, Owens TE. 2002. Population status of bald eagles breeding in Washington at the end of the 20th century. Jour nal of Raptor Research 36:161-169.

Local or global food markets: A comparison of energy use for transport

This study compares energy use for food transport to a farmers' market in Sweden with energy use for transport in the conventional food system. The farmers' market was investigated through data sampling from on-site investigations. The conventional food system was studied with the aid of life cycle assessments reported in the literature. Overall, the study found no significant differences in levels of energy use for transport to the farmers' market compared with the conventional food system. For certain products, such as fresh fruits and vegetables, transport-related energy use was much lower in the local system although the season in Sweden for this kind of product is restricted to two or three months at the end of the summer. However, there is considerable potential to increase energy efficiency in local food systems by organizing the selling in new ways and by using more energy efficient vehicles.

Transfer of 137Cs from Chernobyl debris and nuclear weapons fallout to different Swedish population groups

Data from measurements on the body burden of 134Cs, 137Cs and 40K in various Swedish populations between 1959 and 2001 has been compiled into a national database. The compilation is a co-operation between the Departments of Radiation Physics in Malmö and Göteborg, the National Radiation Protection Authority (SSI) and the Swedish Defense Research Agency (FOI). In a previous study the effective ecological half time and the associated effective dose to various Swedish populations due to internal contamination of 134Cs and 137Cs have been assessed using the database. In this study values of human body burden have been combined with data on the local and regional ground deposition of fallout from nuclear weapons tests (only 137Cs) and Chernobyl debris (both 134Cs and 137Cs), which have enabled estimates of the radioecological transfer in the studied populations.The assessment of the database shows that the transfer of radiocesium from Chernobyl fallout to humans varies considerably between various populations in Sweden. In terms of committed effective dose over a 70 y period from internal contamination per unit activity deposition, the general (predominantly urban) Swedish population obtains 20–30 μSv/kBq m−2. Four categories of populations exhibit higher radioecological transfer than the general population; i.) reindeer herders (∼700 μSv/kBq m−2), ii.) hunters in the counties dominated by forest vegetation (∼100 μSv/kBq m−2), iii.) rural non-farming populations living in sub-arctic areas (40–150 μSv/kBq m−2), and iv.) farmers (∼50 μSv/kBq m−2). Two important factors determine the aggregate transfer from ground deposition to man; i.) dietary habits (intakes of foodstuff originating from natural and semi-natural ecosystems), and ii.) inclination to follow the recommended food restriction by the authorities. The transfer to the general population is considerably lower (∼a factor of 3) for the Chernobyl fallout than during the 1960s and 70s, which is partly explained by a higher awareness of the pathways of radiocaesium to man both by the public and by the regulating authorities, and by the time-pattern of the nuclear weapons fallout during the growth season in Sweden.

Seasonal Patterns of Incidence and Case Fatality of Stroke in Malmö, Sweden: The STROMA Study

Background: Studies on the temporal variation in stroke incidence have reported inconsistent results. Few have studied the temporal variations in case fatality. No study on incidence and case fatality of stroke by season in Sweden has been found. This study explores the weekly, monthly and seasonal variations in incidence and 28-day case fatality of stroke. Methods: A total of 7,129 patients with first-ever stroke during the period 1989–1999 were retrieved from the Stroke Register of Malmö, Sweden. χ² test was performed to test the seasonal differences and Poisson regression analysis was used to calculate the case fatality ratios adjusted for sex and age. Results: The stroke cases were on the whole randomly distributed over the study period of 4,017 days. Incidence of all types of stroke, intracerebral hemorrhage and subarachnoid hemorrhage showed no variation by season, month or weekday, but incidence of cerebral infarction for the total population was higher in autumn and winter. Twenty-eight-day case fatality (930 fatal events, 13%) clustered significantly over the study period. Winter emerged as the peak season among men (12.5%), women (17.2%) and total population (15.1%). No consistent variation of incidence and case fatality of stroke by month or weekday was found. Conclusion: Case fatality after stroke demonstrates a seasonal variation with a peak in winter. Incidence of stroke showed no consistent association with season, month or weekday.

Seroprevalence of Dictyocaulus viviparus in first grazing season calves in Sweden

A serological survey was carried out to determine the prevalence and geographical distribution of Dictyocaulus viviparus in calves after their first grazing season in Sweden. A total of 754 animals from 76 randomly selected herds in seven geographical regions were examined between September 24 and December 19, 2001. To get an indication about the geographical distribution of the infection 41 herds with beef-suckler calves were investigated. On each farm, blood was collected from 8 to 10 animals after an average of 26 ± 24 days post-housing to determine specific IgG 1 levels against a possible lungworm sperm antigen that is highly specific against patent infections of D. viviparus. We also investigated the seroprevalence of lungworm infection in relation to cattle management. In one region additional samples were analysed from 35 herds either with: (a) beef-suckling calves that were dewormed at housing, (b) untreated organically raised dairy calves, and finally from conventionally raised dairy calves either, (c) with or, (d) without a prophylactic anthelmintic treatment programme against gastrointestinal parasites on pasture. A questionnaire was used to obtain information about herd size and management, including measures to control nematode parasites on the farm. A total of 86 (11.8%) out of 754 animals had antibodies against D. viviparus, and at least one infected individual was detected in 30 (39.5%) of the 76 herds examined. Lungworm infected animals were found throughout the country and there was no significant differences between regions, although in southern and southwestern Sweden 70.0% of the herds were infected. Furthermore, there were no major differences in the seroprevalence in relation to management. Between 40.0 and 44.4% of the herds were infected irrespective of management, with the exception of calves from organic herds where no seropositive samples were found (0%). This result is in contrast to previous findings of lungworms in Sweden, and indicates that the parasite status on organic farms is diverse.

Winter survival in Sweden of L 3-stage larvae of the ostrich wireworm Libyostrongylus douglassii

Libyostrongylus douglassii, a pathogenic trichostrongylid nematode of the ostrich, was recently identified as a potentially important parasite in ostriches on Swedish farms. This parasite is well adapted to the hot and dry climates of sub-Saharan Africa, the natural habitat of the ostrich. The influence of low temperatures in colder climates, such as in Sweden, on free-living stages of L. douglassii is however insufficiently known. In this study, parasite free ostrich faeces were mixed with infective L 3-stage larvae of L. douglassii, which had been cultured from eggs obtained from two Swedish farms. Samples of the mixture were placed on a grass surface, and analyses for L 3-stage larvae were performed at regular intervals. The results of the study showed that L 3-stage larvae may remain alive during a period of at least 97 days on pasture during the winter season in Sweden, even when the temperature within the samples was repeatedly below −0.1 °C, and the air temperature varied between −19.6 and +14.9 °C. It was concluded that L 3-stage larvae of L. douglassii probably have the ability to remain viable on pastures during winter in Sweden.