Productivity at stump harvest

Stump harvest could be found in the late 1970's and the early 1980's. And now when the prices on energy are high it has become an interesting topic again. This work has been conducted within Holmen Skog's stump harvest testing in Norrköping. The purpose was to: Investigate the time consumption for harvesting and forwarding of stumps and the distribution of time on the different work phases; Make an economic analysis of stump harvest; Evaluate the number of, and quality of, the soil preparation were no extra measure was taken; Make an overview of the market of stump harvest devices. There are 3-4 different devices for stump harvest on the market and the most common is the Finnish device Pallari. It has been used in this study where harvest of ca 400 stumps has been studied and the time consumption has been recorded. The productivity of stump harvest was on average 4.1 tonTS/G0-tim and the mean size of the stump was 131 kgTS. Time consumption was different according to the diameter of the stump, tree species and the humidity of the soil. Stumps from spruce on fresh soil took less time to harvest than stumps from spruce on moist soil. Stumps from pine took more time to harvest than stumps from spruce. A stump with a diameter of 20 cm took 55-70 s to harvest and a stump with a diameter of 60 cm took 170-220 s to harvest. Due to the larger stumps higher volume was the production in tonTS/h considerable higher for large stumps. The cost for stump harvest and forwarding with this method was on average 77 SEK/MWh when 100 % of the stumps were removed. The average withdrawal was 54.7 tonTS/ha. Crane movement was the work phase that took the longest time, 48 % of the total time consumption was due to that phase. The number of soil preparation points was on average 3675 per hectare.Stubbskörd var aktuellt på 1970-80-talet, och har med stigande energipriser återigen blivit en het fråga. Det här arbetet har utförts inom Holmen skogs stubbskördsförsök i Norrköping och syftet var att: undersöka tidsåtgången för skörd och skotning av stubbar samt fördelningen av tiden på olika arbetsmoment. Vidare utföra en ekonomisk analys av stubbskörd och bedöma antal och kvalité på markberedningspunkter efter stubbskörd där inga extra markberedningsåtgärder genomförs och sammanställa en översikt av marknadens olika stubbskördsaggregat. Det finns 3-4 olika stubbskördsaggregat på marknaden, vanligast är det finländska aggregatet Pallari. Det har använts i den här studien där skörd av ca 400 stubbar har tidsstuderats. Produktiviteten vid stubbskörd var i medeltal 4,1 tonTS/G0-tim och medelstubben var på 131 kgTS. Tiden för att lyfta stubbar var beroende på stubbarnas diameter, trädslag och markens fuktighet. Granstubbar på frisk mark tog kortare tid att skörda än granstubbar på fuktig mark. Tallstubbar på frisk mark tog längre tid att skörda än granstubbar på frisk mark. En stubbe med diametern 20 cm tog ca 55-70 s att skörda och en stubbe med diameter 60 cm tog ca 160-220 s att skörda. Beroende på stora stubbars större volym blev ändå produktionen i tonTS/tim betydligt högre för stora stubbar. Kostnaden för stubbskörd och skotning med den här metoden var 77 SEK/MWh när 100 % av stubbarna tas ut. Det genomsnittliga uttaget var 54,7 tonTS/ha. Kranarbete var det moment som tog längst tid vid stubbskörd (48 %). Därefter följde rensning med 20 % och upplyftning med 18 % av tiden. Antalet markberedningpunkter var i genomsnitt 3675 stycken per hektar

Conventional epidemiology underestimates the incidence of asthma and wheeze - a longitudinal population-based study among teenagers

BACKGROUND: Because of shifts in the gender ratio and incidence and remission rates of asthma during the teen ages, the methodology of incidence studies among teenagers is important, i.e. if the time intervals between surveys are too long, the incident cases might not be properly identified. The aim was to study the impact of study design on the incidence rates of asthma and wheeze during the teen ages. METHODS: In a study about asthma and allergic diseases within the OLIN studies (Obstructive Lung Disease in northern Sweden), a cohort of school children (n = 3,430) was followed annually by questionnaire from age 8 yrs. In the endpoint survey (age 18 yrs) 2,582 (75% of original responders) participated. Incident cases from age 12-18 yrs were identified by two methods: annual questionnaire reports (AR) and baseline-endpoint surveys only (BE). RESULTS: The cumulative incidence of asthma and wheeze was significantly higher based on AR compared to BE. Compared to the incidence rates based on all the annual surveys, the calculated average annual rates based on BE were in general lower both among the boys and among the girls. There were no differences between boys and girls in incidence rates of asthma or wheeze during the early teen years. However, from the age of 15 years, the annual incidence rates were significantly or borderline significantly higher among girls than boys. At onset, the additional cases of current asthma identified by AR had significantly less severe asthma than those identified in BE (p < 0.02). CONCLUSION: the size of the incidence of asthma and wheeze during the teen ages was influenced by study design. By using the conventional prospective study design with longer follow-up time, the incidence was underestimated

Heavy vehicle traffic is related to wheeze among schoolchildren: a population-based study in an area with low traffic flows

<p>Abstract</p> <p>Background</p> <p>An association between traffic air pollution and respiratory symptoms among children has been reported. However, the effects of traffic air pollution on asthma and wheeze have been very sparsely studied in areas with low traffic intensity in cold climate with poor dispersion. We evaluated the impact of vehicle traffic on childhood asthma and wheeze by objective exposure assessment.</p> <p>Methods</p> <p>As a part of the Obstructive Lung Disease in Northern Sweden (OLIN) studies, a questionnaire was sent to the families of all children attending first or second grade in Luleå (72,000 inhabitants) in Northern Sweden in 2006. The age of the children was 7-8 years and the participation rate was 98% (n = 1357). Skin prick tests were performed in 1224 (89%) children. The home addresses were given geographical coordinates and traffic counts were obtained from the local traffic authorities. A proximity model of average daily traffic and average daily heavy vehicle traffic within 200 meters from each participant's home address was used. The associations between traffic exposure and asthma and wheeze, respectively, were analysed in an adjusted multiple logistic regression model.</p> <p>Results</p> <p>Exposure to high traffic flows was uncommon in the study area; only 15% of the children lived within 200 meters from a road with a traffic flow of ≥8000 vehicles per day. Living closer than 200 meters from a road with ≥500 heavy vehicles daily was associated with current wheeze, odds ratio 1.7 (confidence interval 1.0-2.7). A dose-response relation was indicated. An increased risk of asthma was also seen, however not significant, odds ratio 1.5 (confidence interval 0.8-2.9). Stratified analyses revealed that the effect of traffic exposure was restricted to the non-sensitized phenotype of asthma and wheeze. The agreement between self-reported traffic exposure and objective measurements of exposure was moderate.</p> <p>Conclusions</p> <p>This study showed that already at low levels of exposure, vehicle traffic is related to an increased risk of wheeze among children. Thus, the global burden of traffic air pollution may be underestimated.</p

High incidence and remission of reported food hypersensitivity in Swedish children followed from 8 to 12 years of age – a population based cohort study

Background: Few population-based cohort studies have examined reported food hypersensitivity longitudinally. We investigated prevalence, incidence and remission of perceived food hypersensitivity among schoolchildren from 8 to 12 years of age, and risk factors associated with incidence and remission. Methods: A population-based cohort including all 7–8 year-old children in three Swedish towns was recruited in 2006. A total of 2,585 (96% of invited) children participated in a parental questionnaire. The children in two of the towns, n = 1,700 (90% of invited) also participated in skin-prick-testing with airborne allergens. The cohort was followed using the same methods at 11–12 years of age. At study follow up, specific IgE to foods was analyzed in a randomized subset of children (n = 652). Results: The prevalence of perceived food hypersensitivity increased from 21% at 8 years to 26% at 12 years of age. During this four-year-period, the cumulative incidence of food hypersensitivity was high (15%), as was remission (33%). This pattern was particularly evident for hypersensitivity to cow´s milk, while the incidence of hypersensitivity to other foods was lower. Female sex, allergic heredity, current rhinitis and allergic sensitization were associated with the incidence of food hypersensitivity and allergic sensitization was negatively associated with remission. Risk-factor-patterns for both incidence and remission were different for hypersensitivity to milk compared with hypersensitivity to other foods. Generally, the agreement between reported food hypersensitivity and IgE-sensitization to the implicated food was poor. Conclusions: In this longitudinal, population-based cohort-study perceived food hypersensitivity was common among children between ages 8 and 12, often transient and not well correlated with food-specific IgE. While these findings suggest an overestimated prevalence of food hypersensitivity, the public-health-significance remains high as they reflect the perceived reality to which the children adapt their life and food intakes

Low socioeconomic status relates to asthma and wheeze, especially in women

Low socioeconomic status (SES) has been associated with asthma and wheezing. Occupational group, educational level and income are commonly used indicators for SES, but no single indicator can illustrate the entire complexity of SES. The aim was to investigate how different indicators of SES associate with current asthma, allergic and nonallergic, and asthmatic wheeze. In 2016, a random sample of the population aged 20–79 years in Northern Sweden were invited to a postal questionnaire survey, with 58% participating (n=6854). The survey data were linked to the national Integrated Database for Labour Market Research by Statistics Sweden for the previous calendar year, 2015. Included SES indicators were occupation, educational level and income. Manual workers had increased risk for asthmatic wheeze, and manual workers in service for current asthma, especially allergic asthma. Primary school education associated with nonallergic asthma, whereas it tended to be inversely associated with allergic asthma. Low income was associated with asthmatic wheeze. Overall, the findings were more prominent among women, and interaction analyses between sex and income revealed that women, but not men, with low income had an increased risk both for asthmatic wheeze and current asthma, especially allergic asthma. To summarise, the different indicators of socioeconomic status illustrated various aspects of associations between low SES and asthma and wheeze, and the most prominent associations were found among women.Peer reviewe

High but stable incidence of adult-onset asthma in northern Sweden over the last decades

Background The prevalence of asthma has increased both among children and adults during the latter half of the 20th century. The prevalence among adults is affected by the incidence of asthma not only in childhood but also in adulthood. Time trends in asthma incidence have been poorly studied. Aims The aim of this study was to review the incidence of adult-onset asthma from 1996 to 2006 and 2006 to 2016 and compare the risk factor patterns. Methods In the Obstructive Lung Disease in Northern Sweden (OLIN) studies, two randomly selected population-based samples in the 20-69-year age group participated in postal questionnaire surveys about asthma in 1996 (n=7104, 85%) and 2006 (n=6165, 77%). A 10-year follow-up of the two cohorts with the same validated questionnaire was performed, and 5709 and 4552 responded, respectively. Different definitions of population at risk were used in the calculations of asthma incidence. The protocol followed a study performed between 1986 and 1996 in the same area. Results The crude incidence rate of physician-diagnosed asthma was 4.4 per 1000 person-years (men 3.8, women 5.5) from 1996 to 2006, and 4.8 per 1000 person-years (men 3.7, women 6.2) from 2006 to 2016. When correcting for possible under-diagnosis at study entry, the incidence rate was 2.4 per 1000 personyears from 1996 to 2006 and 2.6 per 1000 person-years from 2006 to 2016. The incidence rates were similar across age groups. Allergic rhino-conjunctivitis was the main risk factor for incident asthma in both observation periods (risk ratio 2.4-2.6). Conclusions The incidence of adult-onset asthma has been stable over the last two decades and has remained at a similar level since the 1980s. The high incidence contributes to the increase in asthma prevalence.Peer reviewe

The Normal Red-Letter, volume 3, number 3, December (1901)

https://red.mnstate.edu/normalredletter/1013/thumbnail.jp

Restrictive spirometric pattern in the general adult population : Methods of defining the condition and consequences on prevalence

Background: Attempts have been made to use dynamic spirometry to define restrictive lung function, but the definition of a restrictive spirometric pattern (RSP) varies between studies such as BOLD and NHANES. The aim of this study was to estimate the prevalence and risk factors of RSP among adults in northern Sweden based on different definitions. Methods: In 2008-2009 a general population sample aged 21-86y within the obstructive lung disease in northern Sweden (OLIN) studies was examined by structured interview and spirometry, and 726 subjects participated (71% of invited). The prevalence of RSP was calculated according to three different definitions based on pre-as well as post-bronchodilator spirometry: 1) FVC 0.7 2) FVC LLN 3) FVC LLN Results: The three definitions yielded RSP prevalence estimates of 10.5%, 11.2% and 9.4% respectively, when based on pre-bronchodilator values. The prevalence was lower when based on post-bronchodilator values, i.e. 7.3%, 7.9% and 6.6%. According to definition 1 and 2, the RSP prevalence increased by age, but not according to definition 3. The overlap between the definitions was substantial. When corrected for confounding factors, manual work in industry and diabetes with obesity were independently associated with an increased risk for RSP regardless of definition. Conclusions: The prevalence of RSP was 7-11%. The prevalence estimates differed more depending on the choice of pre-compared to post-bronchodilator values than on the choice of RSP definition. RSP was, regardless of definition, independently associated with manual work in industry and diabetes with obesity. (C) 2016 The Authors. Published by Elsevier Ltd.Peer reviewe

Differences in diagnostic patterns of obstructive airway disease between areas and sex in Sweden and Finland-the Nordic EpiLung study

Objective:To investigate the current prevalence of physician-diagnosed obstructive airway diseases by respiratory symptoms and by sex in Sweden and Finland. Method:In 2016, a postal questionnaire was answered by 34,072 randomly selected adults in four study areas: Vastra Gotaland and Norrbotten in Sweden, and Seinajoki-Vaasa and Helsinki in Finland. Results:The prevalence of asthma symptoms was higher in Norrbotten (13.2%), Seinajoki-Vaasa (14.8%) and Helsinki (14.4%) than in Vastra Gotaland (10.7%), and physician-diagnosed asthma was highest in Norrbotten (13.0%) and least in Vastra Gotaland (10.1%). Chronic productive cough was most common in the Finnish areas (7.7-8.2% versus 6.3-6.7%) while the prevalence of physician-diagnosed chronic bronchitis (CB) or chronic obstructive pulmonary disease (COPD) varied between 1.7 and 2.7% in the four areas. Among individuals with respiratory symptoms, the prevalence of asthma was most common in Norrbotten, while a diagnosis of COPD or CB was most common in Vastra Gotaland and Seinajoki-Vaasa. More women than men with respiratory symptoms reported a diagnosis of asthma in Sweden and Seinajoki-Vaasa but there were no sex differences in Helsinki. In Sweden, more women than men with symptoms of cough or phlegm reported a diagnosis of CB or COPD, while in Finland the opposite was found. Conclusion:The prevalence of respiratory symptoms and corresponding diagnoses varied between and within the countries. The proportion reporting a diagnosis of obstructive airway disease among individuals with respiratory symptoms varied, indicating differences in diagnostic patterns both between areas and by sex.Peer reviewe

Receiving support to quit smoking and quit attempts among smokers with and without smoking related diseases: Findings from the EUREST-PLUS ITC Europe Surveys

Introduction: Having a chronic disease either caused or worsened by tobacco smoking does not always translate into quitting smoking. Although smoking cessation is one of the most cost-effective medical interventions, it remains poorly implemented in healthcare settings. The aim was to examine whether smokers with chronic and respiratory diseases were more likely to receive support to quit smoking by a healthcare provider or make a quit attempt than smokers without these diseases. Methods: This population-based study included a sample of 6011 adult smokers in six European countries. The participants were interviewed face-to-face and asked questions on sociodemographic characteristics, current diagnoses for chronic diseases, healthcare visits in the last 12 months and, if so, whether they had received any support to quit smoking. Questions on smoking behavior included nicotine dependence, motivation to quit smoking and quit attempts in the last 12 months. The results are presented as weighted percentages with 95% confidence intervals (CI) and as adjusted odds ratios with 95% CI based on logistic regression analyses. Results: Smokers with chronic respiratory disease, those aged 55 years and older, as well as those with one or more chronic diseases were more likely to receive smoking cessation advice from a healthcare professional. Making a quit attempt in the last year was related to younger age, high educational level, higher motivation to quit, lower nicotine dependence and having received advice to quit from a healthcare professional but not with having chronic diseases. There were significant differences between countries with smokers in Romania consistently reporting more support to quit as well as quit attempts. Conclusions: Although smokers with respiratory disease did indeed receive smoking cessation support more often than smokers without disease, many smokers did not receive any advice or support to quit during a healthcare visit