| 1. |
- Al-Sarraj, Razaw, et al.
(author)
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Generalized prediction intervals for treatment effects in random-effects models
- 2019
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In: Biometrical Journal. - : Wiley. - 0323-3847 .- 1521-4036. ; 61, s. 1242-1257
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Journal article (peer-reviewed)abstract
- This article derives generalized prediction intervals for random effects in linear random-effects models. For balanced and unbalanced data in two-way layouts, models are considered with and without interaction. Coverage of the proposed generalized prediction intervals was estimated in a simulation study based on an agricultural field experiment. Generalized prediction intervals were compared with prediction intervals based on the restricted maximum likelihood (REML) procedure and the approximate methods of Satterthwaite and Kenward and Roger. The simulation study showed that coverage of generalized prediction intervals was closer to the nominal level 0.95 than coverage of prediction intervals based on the REML procedure.
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| 2. |
- Andrée O´ Hara, Elisabeth, et al.
(author)
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An observational study of the dry period length and its relation to milk yield, health, and fertility in two dairy cow breeds
- 2020
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In: Preventive Veterinary Medicine. - : Elsevier BV. - 0167-5877 .- 1873-1716. ; 175
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Journal article (peer-reviewed)abstract
- This study evaluated associations between dry period length (DPL) in dairy cows and energy-corrected milk (ECM) production, health, and fertility, using a dataset involving 78 577 lactations in cows of two breeds, Swedish Red (SR) and Swedish Holstein (SH). Herds with at least 20 cows and at least 20 % purebred SR and at least 20 % SH during the year 2015/2016 were included in the dataset. Cows were divided into parity groups 2 and 3 or older and DPL was classified into six 10-day groups (30-39 to 80-89 d). Associations between DPL and the outcome variables were assessed with linear and generalized linear mixed models. Production of ECM at the first three test milkings and the 305-d lactation was highest in the 50-59 d and 60-69 d DPL groups, and lowest in the 30-39 d and 80-89 d groups (p<0.001). Mastitis and somatic cell count (SCC) did not differ between DPL groups, except at the third test milking, where cows in the 40-49, 50-59, and 60-69 DPL groups had lower SCC (p<0.001) than cows in the 70-79 and 80-89 d groups. The odds ratio (OR) for retained placenta was 1.9 for cows with 30-39 d DPL relative to cows with 60-69 d DPL. Cows in DPL groups 40-49 d and 50-59 ha d the lowest odds of culling (OR=0.89 and 0.92). The OR for culling in cows with DPL 70-79 d and 80-89 was 1.2 and 1.4, respectively, relative to cows with 60-69 d DPL. The conception rate at first insemination did not among between DPL groups. The SR cows produced less ECM than the SH cows, but had lower SCC and lower OR for mastitis, retained placenta, puerperal paresis, and culling within 90 DIM. Although DPL <40 days or >80 days reduced milk production in early lactation and the 305-d lactation, the estimated additional milk production in the preceding lactation in cows with short DPL compensated for this reduction. A DPL of 40 days did not affect health and fertility in comparison with a conventional 60 d DPL, while a DPL of >70 d was unfavorable due to low milk production, increased risk of culling, and decreased fertility. The response to DPL was not affected by breed or parity.
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| 3. |
- Bengtsson, Stina, et al.
(author)
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Seasonal Pattern of Lesion Development in Diseased Fraxinus excelsior Infected by Hymenoscyphus pseudoalbidus
- 2014
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9
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Journal article (peer-reviewed)abstract
- Ash dieback is a recent widespread disease on ash (Fraxinus sp.) that is causing important economic and ecological losses throughout Europe. The disease is initiated by the ascomycetous fungus Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea). The main aim of this study was to investigate seasonal pattern of lesion development associated with ash dieback. We present data on the spread of 324 natural lesions in ash shoots, branches and stems surveyed over a 32 month period. Most lesions were active and showed the greatest rate of growth during the summer; however, lesions were active throughout the year. Tree mortality was high, with more than a third of the surveyed trees dying during the study. Although many lesions permanently ceased to develop, the rate at which new lesions emerged was greater than the rate at which lesions entered a resting phase. The most common cause for a lesion going into a permanent state of rest was that it had encountered a branch-base. Genotype analysis showed that multiple infections can occur in a single tree given that different genotypes were identified in different lesions as well as in single lesions. A weak positive correlation was noted between tree health and tree size and a weak negative correlation was noted between tree overall health and lesion activity. The lower limit for H. pseudoalbidus growth in culture was between 4.0 degrees C and 0.5 degrees C.
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| 4. |
- Björkman, Camilla, et al.
(author)
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Disinfection with hydrated lime may help manage cryptosporidiosis in calves
- 2018
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In: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 264, s. 58-63
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Journal article (peer-reviewed)abstract
- Diarrhea is common in young calves and is often caused by Cryptosporidium parvum infection. The aim of this study was to investigate if disinfection of calf pens with hydrated lime would reduce contamination of C. parvum oocysts and improve calf health in herds with C. parvum associated diarrhea problems. Four dairy herds with ongoing C. parvum associated calf diarrhea problems each participated in the study over six to seven months. During the study period, all pens/huts for young calves were cleaned according to the usual farm routine before a new calf entered. Hydrated lime was then used to disinfect half of the pens/huts. Diarrhea incidence was recorded by the farmers and by veterinarians, who clinically examined the calves every second month. In total, 402 calves participated in the study. The farmers detected diarrhea in 214 (53%) calves, with similar proportions in calves kept in lime disinfected and control pens. Age at diarrhea onset was significantly higher in lime disinfected pens than in control pens, 9.0 days and 7.6 days, respectively. There was no difference between the groups regarding duration or severity index recorded by the farmers. The body condition score in 6-8 week old calves was significantly higher in calves that had been kept in lime disinfected pens during their first weeks of life, indicating that calves in disinfected pens/huts were less affected by their infections.Faecal samples from 5 to 21 day old calves, were collected on four occasions at each farm (n = 95). Cryptosporidium positive samples were found at all samplings in all four herds. Cryptosporidium spp. was detected in 79 (83%) samples with no difference between lime disinfected and control pens. C. parvum was the dominant species. Two different C. parvum subtypes were found; IIaA16G1R1b in three herds and IIaA16G1R1b_variant in one herd. Only one subtype was found in each herd.Disinfection of calf pens with slaked lime delayed onset of diarrhea and improved the body condition in the calves, but did not affect diarrhea incidence or duration. Although lime disinfection alone will not be sufficient to control Cryptosporidium associated diarrhea in herds with extensive calf diarrhea problems, these results suggest that it can be a valuable complement to other measures.
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| 5. |
- Burauskaite-Harju, Agne, 1981-, et al.
(author)
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A test for network-wide trends in rainfall extremes
- 2012
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In: International Journal of Climatology. - : Wiley. - 0899-8418 .- 1097-0088. ; 32:1, s. 86-94
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Journal article (peer-reviewed)abstract
- Temporal trends in meteorological extremes are often examined by first reducing daily data to annual index values, such as the 95th or 99th percentiles. Here, we report how this idea can be elaborated to provide an efficient test for trends at a network of stations. The initial step is to make separate estimates of tail probabilities of precipitation amounts for each combination of station and year by fitting a generalised Pareto distribution (GPD) to data above a user-defined threshold. The resulting time series of annual percentile estimates are subsequently fed into a multivariate Mann-Kendall (MK) test for monotonic trends. We performed extensive simulations using artificially generated precipitation data and noted that the power of tests for temporal trends was substantially enhanced when ordinary percentiles were substituted for GPD percentiles. Furthermore, we found that the trend detection was robust to misspecification of the extreme value distribution. An advantage of the MK test is that it can accommodate non-linear trends, and it can also take into account the dependencies between stations in a network. To illustrate our approach, we used long time series of precipitation data from a network of stations in The Netherlands.
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| 6. |
- Burauskaite-Harju, Agne, et al.
(author)
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Statistical framework for assessing trends in sub-daily and daily precipitation extremes
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Other publication (other academic/artistic)abstract
- Extreme precipitation events vary with regard to duration, and hence sub-daily data do not necessarily exhibit the same trends as daily data. Here, we present a framework for a comprehensive yet easily undertaken statistical analysis of long-term trends in daily and sub-daily extremes. A parametric peaks-over-threshold model is employed to estimate annual percentiles for data of different temporal resolution. Moreover, a trend-durationfrequency table is used to summarize how the statistical significance of trends in annual percentiles varies with the temporal resolution of the underlying data and the severity of the extremes. The proposed framework also includes nonparametric tests that can integrate information about nonlinear monotonic trends at a network of stations. To illustrate our methodology, we use climate model output data from Kalmar, Sweden, and observational data from Vancouver, Canada. In both these cases, the results show different trends for moderate and high extremes, and also a clear difference in the statistical evidence of trends for daily and sub-daily data.
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| 7. |
- Chenais, Erika, et al.
(author)
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Quantitative assessment of social and economic impact of African swine fever outbreaks in northern Uganda
- 2017
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In: Preventive Veterinary Medicine. - : Elsevier BV. - 0167-5877 .- 1873-1716. ; 144, s. 134-148
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Journal article (peer-reviewed)abstract
- African swine fever (ASF) is one of the most important pig diseases, causing high case fatality rate and trade restrictions upon reported outbreaks. In Uganda, a low-income country with the largest pig population in East Africa, ASF is endemic.Animal disease impact is multidimensional and include social and economic impact along the value chain. In low-income settings, this impact keep people poor and push those that have managed to escape poverty back again. If the diseases can be controlled, their negative consequences can be mitigated. However, to successfully argue for investment in disease control, its cost-benefits need to be demonstrated. One part in the cost-benefit equations is disease impact quantification. The objective of this study was therefore to investigate the socio-economic impact of ASF outbreaks at household level in northern Uganda.In a longitudinal study, structured interviews with two hundred, randomly selected, pig-keeping households were undertaken three times with a six month interval. Questions related to family and pig herd demographics, pig trade and pig business.Associations between ASF outbreaks and economic and social impact variables were evaluated using linear regression models. The study showed that pigs were kept in extreme low-input-low-output farming systems involving only small monetary investments. Yearly incidence of ASF on household level was 19%. Increasing herd size was positively associated with higher economic output. The interaction between ASF outbreaks and the herd size showed that ASF outbreaks were negatively associated with economic output at the second interview occasion and with one out of two economic impact variables at the third interview occasion. No significant associations between the social impact variables included in the study and ASF outbreaks could be established. Trade and consumption of sick and dead pigs were coping strategies used to minimize losses of capital and animal protein.The results indicate that causality of social and economic impact of ASF outbreaks in smallholder systems is complex. Pigs are mostly kept as passive investments rather than active working capital, complicating economic analyses and further disqualifying disease control arguments based only on standard economic models. (C) 2017 The Authors. Published by Elsevier B.V.
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| 8. |
- Edvardsson Rasmussen, Anna, et al.
(author)
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A randomized study on the effect of an extended voluntary waiting period in primiparous dairy cows on fertility, health, and culling during first and second lactation
- 2023
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In: Journal of Dairy Science. - 0022-0302 .- 1525-3198. ; 106, s. 8897-8909
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Journal article (peer-reviewed)abstract
- When the voluntary waiting period (VWP), defined as the days between calving and when the cow is eligible to receive the first insemination, is extended, high-yielding dairy cows may have better opportunities to regain energy balance before first insemination. This study investigated the effect of an extended (145–215 days in milk [DIM], n = 280) or conventional (25–95 DIM, n = 251) VWP treatment on fertility, disease incidence, and culling rate in cows during their first lactation. The cows were also followed through a second lactation without intervention regarding VWP, during which the farmers could decide when they wished to start the inseminations. This was done in a randomized-controlled study on 16 high-yielding commercial herds in southern Sweden, containing a total of 531 primiparous cows of the Holstein and Red Dairy Cattle breeds. Data from the Swedish national dairy herd recording scheme collected between August 2018 and September 2021 were used in the analysis, including records on breed, calvings, estrus intensity, inseminations, disease, somatic cell count, culling date, and culling reason. During first lactation, more cows receiving the extended VWP treatment showed strong estrus intensity (score 4–5, 55% vs. 48%) and fewer showed moderate estrus intensity (score 3, 35% vs. 43%) at first insemination, compared with cows receiving the conventional VWP treatment. First service conception rate (FSCR) was higher (67% vs. 51%) and number of inseminations per conception (NINS) was lower (1.6 vs. 2.0) during the first lactation for cows receiving the extended compared with the conventional VWP treatment. For disease incidence rate or culling rate expressed as number of events per cow-time in the study, we found no differences between the cows receiving the 2 VWP treatments in any lactation. Calving to first service interval during second lactation was longer (86 vs. 74 d) for cows with extended compared with conventional VWP. In conclusion, primiparous cows with extended VWP showed improved reproductive functions, in the form of higher estrus intensity, greater FSCR, and lower NINS, during the first lactation. However, we observed no apparent effect on these fertility measures during the following lactation (without VWP intervention) and no differences in disease prevalence or culling between cows receiving the 2 different VWP treatments in either lactation. Compliance with the planned VWP treatment was lower for cows with planned extended compared with planned conventional VWP treatment. We studied the “intention-to-treat” effect (i.e., the results for all cows randomized to each treatment regardless of whether the planned VWP was achieved or not) to identify any bias arising due to degree of compliance. However, we found no difference in culling rate between cows randomized to an extended VWP compared with those randomized to a conventional VWP. These findings can be used to support management decisions on VWP length in high-yielding dairy herds.
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| 9. |
- Eklöf, Karin, et al.
(author)
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Brownification on hold : What traditional analyses miss in extended surface water records
- 2021
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In: Water Research. - : Elsevier Ltd. - 0043-1354 .- 1879-2448. ; 203
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Journal article (peer-reviewed)abstract
- Widespread increases in organic matter (OM) content of surface waters, as measured by color and organic carbon (OC), are a major issue for aquatic ecosystems. Long-term monitoring programs revealed the issue of “brownification”, with climate change, land cover changes and recovery from acidification all suspected to be major drivers or contributing factors. While many studies have focused on the impact and drivers, fewer have followed up on whether brownification is continuing. As time-series of OM data lengthen, conventional data-analysis approaches miss important information on when changes occur. To better identify temporal OM patterns during three decades (1990–2020) of systematic monitoring, we used generalized additive models to analyze 164 time-series from watercourses located across Sweden. Increases in OC that were widespread during 1990–2010 ceased a decade ago, and most color increases ceased 20 years ago. These findings highlight the need to reassess the understanding of brownification's spatial and temporal extent, as well as the tools used to analyze lengthening time series.
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| 10. |
- Eklöf, Karin, et al.
(author)
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Impact of Forestry on Total and Methyl-Mercury in Surface Waters : Distinguishing Effects of Logging and Site Preparation
- 2014
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In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:9, s. 4690-4698
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Journal article (peer-reviewed)abstract
- Forestry operations can increase the export of mercury (both total and methyl) to surface waters. However, little is known about the relative contribution of different forestry practices. We address this question using a paired-catchment study that distinguishes the effects of site preparation from the antecedent logging. Runoff water from three catchments, two harvested and one untreated control, was sampled biweekly during one year prior to logging, two years after logging, and three years after site preparation. The logging alone did not significantly increase the concentrations of either total or methyl-mercury in runoff, but export increased by 50-70% in one of the harvested catchments as a consequence of increased runoff volume. The combined effects of logging and site preparation increased total and methyl-mercury concentrations by 30-50% relative to preharvest conditions in both treated catchments. The more pronounced concentration effect after site preparation compared to logging could be related to site preparation being conducted during summer. This caused more soil disturbance than logging, which was done during winter with snow covering the ground. The results suggest that the cumulative impact of forest harvest on catchment mercury outputs depends on when and how forestry operations are implemented.
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| 11. |
- Eklöf, Karin, et al.
(author)
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Impact of stump harvest on run-off concentrations of total mercury and methylmercury
- 2013
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In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 290, s. 83-94
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Journal article (peer-reviewed)abstract
- Forest harvesting operations have been reported to increase the levels of both total mercury (THg) and methylmercury (MeHg) in runoff water and downstream biota. Mobilization of such harmful substances by logging may pose ecological risks that may be influenced further by site preparation and stump harvest. Stump harvest is currently being explored as a method to increase the supply of biofuels. In this catchment study we investigated the effects of stump harvest, in comparison with ordinary site-preparation, on the runoff concentrations of THg and MeHg as well as several other chemistry parameters. Both treatments were also compared with unharvested reference catchments. Water samples from watercourses draining these catchments were analyzed for various variables including THg, MeHg, total organic carbon, absorbance and total suspended solids. One year of pre-treatment data, starting when the treated areas were just logged, and 2 years of post-treatment data, after stump harvest or site-preparation, were collected with a sample frequency of twice a month. The concentrations of THg and MeHg in the treated areas were decreasing after both stump harvest and site preparation relative to the reference catchment. Further, our results indicate that stump harvest has not caused increased concentrations of any of the studied parameters in relation to traditional site preparation. Two factors are proposed to be responsible for the lack of response to stump harvest and site preparation; (1) the areas are still undergoing recovery from the former logging which may have led to greater Hg export and/or (2) there is variability among sites in how they respond to forestry operations, depending on the biogeochemical and hydrological status of the area. Although no forestry response caused by stump harvest or site preparation was found, we noted that the concentrations of both THg and especially MeHg were high (median THg: 4.5-10.4 ng L-1, median MeHg: 0.7-2.1 ng L-1) in all catchments both before and after treatment, compared to other studies. Variables indicating the organic carbon content were the ones most strongly correlated to the variation of both THg and MeHg in the PLS models based on the dataset from the whole sampling period and all catchments. The relatively high concentrations of THg and MeHg during the study period appeared to be more influenced by organic carbon, but also hydrology and temperature as well as possibly the initial logging rather than by the soil disturbance caused by either stump harvest or site preparation.
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| 12. |
- Elofsson, Katarina, et al.
(author)
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The revealed preferences of Baltic Sea governments : Goals, policy instruments, and implementation of nutrient abatement measures
- 2017
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In: Marine Pollution Bulletin. - : Elsevier. - 0025-326X .- 1879-3363. ; 118:1-2, s. 188-196
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Journal article (peer-reviewed)abstract
- Nitrogen and phosphorus loads are considered a major reason for the eutrophication of the Baltic Sea. Until now, most of the abatement has been made at point sources while the implementation of policies for nonpoint sources has not led to equally large reductions in emissions. The purpose of this study is to investigate the determinants of how nutrient abatement measures are implemented by countries in the agricultural sector of the Baltic Sea region. We investigate how goal setting, policy instrument choice, and the level of implementation is determined by characteristics of the abatement measure as well as socio-economic characteristics of the country where it is implemented. Econometric analysis of a cross-sectional data set suggests that income, institutional capacity, and economies of scope in abatement and enforcement are important determinants of policies developed and their implementation. (C) 2017 The Authors.
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| 13. |
- Falkenö, Ulrika, et al.
(author)
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Biological variation of 20 analytes measured in serum from clinically healthy domestic cats
- 2016
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In: Journal of Veterinary Diagnostic Investigation. - : SAGE Publications. - 1040-6387 .- 1943-4936. ; 28, s. 699-704
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Journal article (peer-reviewed)abstract
- The applications of data on biological variation include assessment of the utility of population-based reference intervals, evaluation of the significance of change in serial results, and setting of analytical quality specifications. We investigated the biological variation of 19 biochemistry analytes and total T4, measured in serum from 7 clinically healthy domestic cats sampled once weekly for 5 weeks. Samples were frozen and analyzed in random order in the same analytical run. Results were analyzed for outliers, and the components of variance, subsequently generated by restricted maximum likelihood, were used to determine within-subject and between-subject variation (CVI and CVG, respectively), as well as analytical variation (CVA) for each analyte. Indices of individuality, reference change values, and analytical performance goals were calculated. The smallest CVI and CVG were found for calcium, chloride, and sodium, whereas the largest values were calculated for bile acids. Nine analytes (albumin, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, cholesterol, creatinine, phosphate [phosphorus], total protein, total T4) demonstrated high individuality, indicating limited utility of population-based reference intervals. Individuality was low, and population-based reference intervals were thereby considered appropriate for 5 analytes (bile acids, calcium, fructosamine, glucose, potassium). The intermediate individuality observed for 4 analytes (creatine kinase, iron, magnesium, urea) indicated that population-based reference intervals should be used with caution.
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| 14. |
- Fölster, Jens, et al.
(author)
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Hur kan resultaten från Omdrevssjöarna användas i vattenförvaltningen?
- 2016
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Reports (other academic/artistic)abstract
- Programmet ”Sjöar Omdrevsstationer: vattenkemi i sjöar” (Omdrevssjöar) omfattar med regionala tillägg, 5084 sjöar som provtas för vattenkemi under höstombland-ningen vart sjätte år (Fölster m.fl. 2014a). Sjöarna är framtagna genom en stratifie-rad slumpning med tätare provtagning i södra Sverige där påverkan är större. Ge-nom att vikta resultaten kan tillståndet i hela Sverige eller i större regioner beskri-vas. I denna rapport redovisas hur Omdrevssjöarna skulle kunna få en ökad an-vändning inom vattenförvaltningen.För många sjöar är de enstaka proverna av vattenkemin det enda dataunderlaget som finns för statusklassning. Genom att uppskatta osäkerheten i klassningen kan man avgöra när det uppmätta värdet är så långt från ett uppsatt gränsvärde att man kan avgöra om sjön t ex uppnår god status eller inte för en viss parameter. För nä-ringsämnen kunde 60 % av Omdrevssjöarna 2007-2009 klassas med avseende på totalfosfor (TotP), men för resten av sjöarna var osäkerheten för stor. Om bedöm-ningen istället gjordes på ett medelvärde av proverna från Riksinventeringarna 2000 och 2005 samt Omdrevssjöarna, kunde 83 % av sjöarna ges en tillförlitlig klassning.Sjöar mindre än 0,5 km2kunde inte representera sjöar större än 0,5 km2, d.v.s. de som räknas som vattenförekomster inom vattenförvaltningen.De mindre sjöarna var generellt jonsvagare, brunare och surare än de större De hade ofta även högre halter av TotP och metaller. Små sjöar hadeockså en högre andelförsurade och metallpåverkade sjöar, samt en lägreandelövergödda sjöar jämfört med stora sjöar.Små sjöar kan alltså inte användas föratt bedöma större sjöar.Omdrevssjöarna har använts för att bedöma andelen försurade sjöar i hela Sverige samt i fyra regioner baserade på bl. a. länsgränser. En uppskattning av osäkerheten i den beräknade andelen visar att för regionerna var konfidensintervallet för den skattade andelen försurade sjöar stort, i storleksordningen +/-25 % av andelenpåverkan. Med hjälp av en statistisk metod (GAM) kunde vi identifiera regioner i Sverige där påverkan av en viss typ är obetydlig. I kombination med påverkansanalysen kan sådana kartor användas för att ”frikänna” regioner och undanta dessa från krav på omfattande övervakningsinsatser. Resurserna kan istället allokeras till de regioner därpåverkan är storoch på så vis bidra till att utforma effektiva och ändamålsen-liga övervakningsprogramoch därmed göra övervakningen riskbaserad. Omdrevssjöarna kan användas till att testa representativiteten hos andra miljööver-vakningsprogram. I en tidigare utvärdering identifierades t ex vissa sjötyper som är underrepresenterade i det nationella Trendsjöprogrammet.Omdrevssjöarna har nu pågått så pass länge att det börjar bli meningsfullt att stu-dera långsiktiga förändringar i den rumsliga fördelningen av vattenkvaliteten. De ovan nämnda statistiska GAM-modellerna är då användbara. Genom att utjämna den småskaliga variationen i tid och rum kan man visa på storskaliga förändringar. Omdrevssjöarna kan visa på tillståndet i alla Sveriges 100 000 sjöar. Eftersom vat-tendirektivet omfattar allt vatten, inte bara de större sjöar som utgör vattenföre-komster, borde resultaten kunna användas i rapporteringen till EU-kommissionen i större utsträckning än idag. Detta gäller särskilt för försurning, som i större ut-sträckning drabbar de mindre sjöarna. , i storleksordningen +/-25 % av andelenpåverkan.
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| 15. |
- Fölster, Jens, et al.
(author)
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Korrigering av vattenkemi för kalkningspåverkan : Val av referenser och beräkning av osäkerheter
- 2011
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Reports (other academic/artistic)abstract
- Kalkning för att motverka försurning har under flera decennier varit en av Sveriges största miljövårdsinsatser. Då försurningstrycket har minskat, finns behov av att minska kalkningsinsatserna. Kalkade sjöar och vattendrag som tidigare varit försurade börjar nu återhämta sig. Kalkdoserna kan då minskas och i en del fall helt avslutas. I vissa fall kan också kalkningen ha startats på felaktiga grunder eftersom underlaget för beslut om att kalka ibland var bristfälligt. När kalkning avslutas ska det inte av misstag ske i vatten som fortfarande är försurade så att återvunna biologiska värden går förlorade. Det är därför viktigt att i varje enskilt fall kunna bedöma hur surhet och försurning skulle vara i ett kalkat vatten om kalkningen avslutades. Den så kallade okalkade surheten och försurningen i kalkade vatten brukar i Sverige beräknas med hjälp av kvoten mellan icke-marint kalcium och magnesium, Ca*/Mg*, från närliggande okalkade referenssjöar. Metoden har använts i flera sammanhang och bedömts ge tillförlitliga resultat i regional skala, men för enskilda vatten är felen ofta stora. I utvärderingen av en stor inventering av alla kalkade så kallade målsjöar 2007 – 2008 poängterades vikten av att minska osäkerheten och att kunna bedöma storleken på osä- kerheten vid beräkning av okalkad surhet och försurning för enskilda vatten. I denna studie utvärderas den befintliga metoden för beräkning av okalkad kemi liksom ansatser till alternativa metoder. Vidare utvärderas variationen i tid och rum hos Ca/Mg i okalkade referenser i ett stort datamaterial med sjöar och vattendrag för att ge underlag till val av metod och beräkning av osäkerheten. Slutligen har verktyg tagits fram för beräkning av okalkad kemi, försurningspåverkan och osäkerheten. Variation i rum och tid av Ca/Mg studerades i ett flertal olika dataset omfattande: • Vattendragsnätverk med provtagning av alla bäckförgreningar i små skogsdominerade avrinningsområden med mellan 15 och 39 provplatser i varje område. • Skogsvattendrag med provtagning mellan 2 och 3 platser längs samma vattendrag omfattande 47 provplatser. • Målsjöundersökningens okalkade referenser utvalda av länsstyrelserna omfattande ca 1800 sjöar. • Trendstationer i 73 sjöar och 67 vattendrag inom den nationella miljöövervakningen. Den hittills använda metoden att beräkna okalkad kemi med den marinkorrigerade kvoten mellan kalcium och magnesium (Ca*/Mg*) jämfördes med motsvarande kvot utan marinkorrigering (Ca/Mg). Det visade sig av Ca/Mg gav mindre fel i uppskattningen av okalkad kemi jämfört med Ca*/Mg*. Ca/Mg var också stabilare i tiden jämfört med Ca*/Mg* som också hade nackdelen att kunna ge negativa värden på beräknad Ca-halt. Alternativa metoder för att beräkna okalkad kemi ur omgivningsfaktorer och kemiska variabler som inte påverkas av kalkning prövades, men de gav inte bättre resultat än metoden med Ca/Mg. Möjligheten att beräkna Ca/Mg ur mineralsammansättningen i markkemidata från miljöövervakningen i skogsmark (RIS-MI) prövades, men de gav stora fel 8 och en kraftig underskattning av Ca/Mg. Vi drog därför slutsatsen att metoden att beräkna okalkad kemi med Ca/Mg-kvoten från okalkade referenser var att föredra. Beräkningen av okalkad kemi med Ca/Mg gav varierande resultat för de olika dataseten. För vattendragsnätverken Krycklan och Ottervattsbäcken i norra Sverige gav modellen tillförlitliga resultat med små fel. I de sydliga vattendragsnätverken gav modellen acceptabla resultat i tre av fyra fall, men först efter att avvikande värden rensats bort. Motiven för att utesluta provplatser var att de hade avvikande geologi i avrinningsområdet eller var misstänkt påverkade av okänd kalkning. Resultaten tyder på att man måste granska referenser noga för att kunna sortera bort sådana som inte är representativa för de kalkade vatten som ska bedömas. Den visar också att man måste vara vaksam på att även om modellen ger god prediktion i de flesta fall, kan den i enstaka fall ge stora fel. Skogsvattendragen omfattar relativt små avrinningsområden som valts ut för att representera skogslandskapet och därför domineras av skog, myr och sjö i avrinningsområdet. För dessa vattendrag fungerade modellen väl, vilket är positivt eftersom den motsvarar vattendrag av samma karaktär och med samma fördelning över landet som många kalkade vatten. Resultaten från målsjöarnas referenser visade på större fel om man inte kunde hitta uppströms liggande referenser som motsvarar minst 20 % av avrinningsområdet. Eftersom uppströms liggande sjöar ofta används som åtgärdssjöar, d.v.s. de kalkas för nedströms effekt på målområden, är man oftast hänvisad till närliggande referenser utanför avrinningsområdet. Den rumsliga variationen ökar ofta med minskande storlek på avrinningsområdet, men för Ca/Mg var denna effekt liten. Det finns därför ingen anledning att utesluta referenser med små avrinningsområden, även om större avrinningsområden är att föredra. En databas med referenssjöar för värden på Ca/Mg togs fram. Den bestod av 1622 okalkade referenser inom målsjöinventeringen som provtogs både hösten 2007 och våren 2008. Sjöar med stor variation i Ca/Mg (skillnaden mellan de två provtagningarna i Ca/Mg större än 1) och misstänkt kalkpåverkade sjöar (både Ca/Mg > 3 och pH > 6,2) hade då rensats ut ur datasetet. I första hand bör uppströms liggande referenser väljas. Om det saknas uppströms liggande referenser bör referensvärdet för Ca/Mg beräknas som medelvärdet av referenserna inom 20 km avstånd bland de referenser som ingår i databasen. Detta värde gav i regel mindre fel än om den referens som länsstyrelserna valt ut för varje sjö användes. Två verktyg togs fram för beräkning av okalkad kemi och försurningspåverkan i kalkade vatten. Verktyget KALKREF tar fram medelvärde och standardavvikelse av Ca/Mg för referenser inom 20 km avstånd. Verktyget OKALK beräknar okalkad kemi, förbereder ett dataset för MAGICbibliotek och tar fram underlag för osäkerhetsbedömning med MonteCarlo-simulering. En tillämpning av verktygen på Målsjöinventeringen visade att 43 % av målsjöarna var försurade med högre sannolikhet än 80 %, medan 24 % hade lägre än 20 % sannolikhet för försurning. För 33 % av sjöarna låg sannolikheten för försurning mellan 20 % och 80 % vilket innebär att försurningsbedömningen är mycket osäker.
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| 16. |
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| 17. |
- Haalck, Inga, et al.
(author)
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Are we using more sugar substitutes? : Wastewater analysis reveals differences and rising trends in artificial sweetener usage in Swedish urban catchments
- 2024
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In: Environment International. - : Elsevier Ltd.. - 0160-4120 .- 1873-6750. ; 190
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Journal article (peer-reviewed)abstract
- The market for artificial sweeteners as substitutes for conventional sugar (sucrose) is growing, despite potential health risks associated with their intake. Estimating population usage of artificial sweeteners is therefore crucial, and wastewater analysis can serve as a complement to existing methods. This study evaluated spatial and temporal usage of artificial sweeteners in five Swedish communities based on wastewater analysis. We further compared their levels measured in wastewater with the restrictions during the COVID-19 pandemic in Sweden and assessed health risks to the Swedish population. Influent wastewater samples (n = 194) collected in March 2019-February 2022 from communities in central and southern Sweden were analyzed for acesulfame, saccharin, and sucralose using liquid-chromatography coupled with tandem mass spectrometry. Spatial differences in loads for individual artificial sweetener were observed, with sucralose being higher in Kalmar (southern Sweden), and acesulfame and saccharin in Enköping and Östhammar (central Sweden). Based on sucrose equivalent doses, all communities showed a consistent prevalence pattern of sucralose > acesulfame > saccharin. Four communities with relatively short monitoring periods showed no apparent temporal changes in usage, but the four-year monitoring in Uppsala revealed a significant (p < 0.05) annual increase of ∼19 % for sucralose, ∼9 % for acesulfame and ∼8 % for saccharin. This trend showed no instant or delayed effects from COVID-19 restrictions, reflecting positively on the studied population which retained similar exposure to the artificial sweeteners despite potential pandemic stresses. Among the three artificial sweeteners, only acesulfame's levels were at the lower end of the health-related threshold for consumption of artificially sweetened beverages; yet, all were far below the acceptable daily intake, indicating no appreciable health risks. Our study provided valuable, pilot insights into the spatio-temporal usage of artificial sweeteners in Sweden and their associated health risks. This shows the usefulness of wastewater analysis for public health authorities wishing to assess future relevant interventions.
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| 18. |
- Hansen, Karin, et al.
(author)
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Trender i kvävenedfall över Sverige 1955-2011
- 2013
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Reports (other academic/artistic)abstract
- Kvävenedfallet har stor betydning för försurning och övergödning. Uppdraget har finansierats av Naturvårdsverket, med syfte att förbättra underlaget för att följa upp miljökvalitetsmålet Bara naturlig försurning . En ny, unik databas har etablerats, med de flesta mätningar som har skett i Sverige av nederbördsmängder och -kemi på öppet fält från 1955 och fram till idag. Beräkningar av nedfallet av oorganiskt kväve (NO3- + NH4+) med nederbörden (våtdepositionen) vid de sammanlagt 362 mätplatserna visar att nedfallet är högre i hela Sverige idag än när mätningarna startade 1955. Data visar en stor variation i kvävenedfallet mellan mätplatser och år, vilket gör det svårt att detektera statistiskt signifikanta förändringar över tid. Nedfallet av kväve med nederbörden till Sverige ökade signifikant under 20-årsperioden 1970-1989 i sydvästra Sverige, men inte i sydöstra eller norra Sverige. Under 20-årsperioden 1990-2009 skedde ingen förändring av nedfallet i norra eller sydvästra Sverige, men i sydöstra Sverige minskade nedfallet av olika kväveformer med nederbörden signifikant. Parallellt har kvävenedfallet uppskattats med MATCH-modellen med två olika simuleringar. Den ena simuleringen (TRENDMATCH) har använt indata från observerad meteorologi tillsammans med emissioner bestämda inom EMEP-programmet medan den andra (KLIMATMATCH) använder meteorologi från en klimatmodell och emissioner sammanställt för RCP4.5. Den med TRENDMATCH modellerade depositionen visar nedåtgående trender för såväl NO3- som NH4+ från 1990 till 2009 i alla regioner. Resultaten från KLIMATMATCH visar inte lika tydliga trender för NH4+, beroende på att de historiska emissionerna i RCP4.5 databasen både visar upp- och nedåtgående trender för perioden. Trender i kvävenedfall beräknade med MATCH-modellen är till mycket stor del styrda av trender i de emissioner som används av spridningsmodellen. Det kan finnas flera orsaker till att vi inte ser tydliga trender i kvävenedfallet under de senaste decennierna. Trendanalyser kräver data med långa tidsserier, vilket av olika orsaker ofta saknas. Om kvävenedfallet har förändrats, men förändringen är liten, så är det svårt eller omöjligt att urskilja detta ur de stora slumpmässiga mellanårsvariationerna. Det är också möjligt att nedfallet inte har förändrats, trots minskande emissioner i Europa, på grund av ändrade atmosfärskemiska förhållanden (t ex klimat och minskande svavelemissioner), eller om utsläppen av kväve från källor som är av vikt för Sverige inte har minskat i samma utsträckning som emissionerna för Europa som helhet har. Det är också svårt att uppskatta kväveemissioner, vilket i rapporten illustreras av de två emissionsuppskattningar som har använts, där den ena rapporterar minskande emissioner av ammoniak och den andra ökande. För att uppnå precision och statistiskt kunna säkerställa förhållandevis små förändringar i kvävenedfallet, i storleksordningen 20 procent under en period av 20 år, behövs mätningar vid ett stort antal platser runt om i landet. Vi föreslår en genomgång av hur de framtida mätningarna av kvävenedfallet, som utgör basen för övervakningen, bör utformas. En viktig punkt är att existerande stationer med långa tidsserier bör bevaras, något som kräver långsiktig finansiering.
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| 19. |
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| 21. |
- Hartmann, Elke, et al.
(author)
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24-h sheltering behaviour of individually kept horses during Swedish summer weather
- 2015
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In: Acta Veterinaria Scandinavica. - : Springer Science and Business Media LLC. - 0044-605X .- 1751-0147. ; 57
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Journal article (peer-reviewed)abstract
- Background: Provision of shelter for horses kept on summer pasture is rarely considered in welfare guidelines, perhaps because the benefits of shelter in warm conditions are poorly documented scientifically. For cattle, shade is a valued resource during summer and can mitigate the adverse effects of warm weather on well-being and performance. We found in a previous study that horses utilized shelters frequently in summer. A shelter with a roof and closed on three sides (shelter A) was preferred and can reduce insect pressure whereas a shelter with roof and open on three sides was not utilized. However, shelter A restricts the all-round view of a horse, which may be important for horses as flight animals. Therefore, we studied whether a shelter with roof, where only the upper half of the rear wall was closed (shelter B), would be utilized while maintaining insect protection properties and satisfying the horses' sense for security. A third shelter was offered with walls but no roof (shelter C) to evaluate whether the roof itself is an important feature from the horse's perspective. Eight Warmblood horses were tested each for 2 days, kept individually for 24 h in two paddocks with access to shelters A and B, or shelters A and C, respectively. Shelter use was recorded continuously during the night (1800-2400 h, 0200-0600 h) and the following day (0900-1600 h), and insect defensive behaviour (e.g., tail swish) in instantaneous scan samples at 5-min intervals during daytime.Results: Seven horses used both shelters A and B, but when given the choice between shelters A and C, shelter C was scarcely visited. There was no difference in duration of shelter use between night (105.8 +/- 53.6 min) and day (100.8 +/- 53.8, P = 0.829). Daytime shelter use had a significant effect on insect defensive behaviours (P = 0.027). The probability of performing these behaviours was lowest when horses used shelter A compared to being outside (P = 0.038).Conclusions: Horses only utilized shelters with a roof whilst a shelter with roof and closed on three sides had the best potential to lower insect disturbance during daytime in summer.
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| 22. |
- Hartmann, Elke, et al.
(author)
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Daytime shelter use of individually kept horses during Swedish summer
- 2015
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In: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 93, s. 802-810
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Journal article (peer-reviewed)abstract
- In Sweden, no provision for summer shelter to protect horses from heat and insects is required, although access to shelter for horses kept outdoors 24 h during winter is a requirement. This study investigated horses' daytime shelter-seeking behavior in relation to weather conditions and insect activity during a 2-wk period in summer. Eight Warmblood riding horses had access to 2 shelters of different design to test which shelter design is preferred by horses. Furthermore, rectal and skin temperatures and insect-defensive behavior were measured to test whether horses would benefit from the provision of shade. The horses were kept alone in paddocks for 4 d. During 2 d, horses had access to 2 shelters: 1) open shelter with roof and uncovered sides and 2) closed shelter with roof, wind nets on 2 sides, and opaque plastic opposite the entrance. Weather conditions (ambient temperature, relative humidity, solar radiation, wind speed) were recorded every 10 min. The number of insects (flies, mosquitos) was counted from insect traps placed in each shelter and outside. Behavior (shelter use, insect-defensive behavior, locomotion, grazing) was recorded at 5-min intervals between 0900 to 1200 h and 1300 to 1600 h and rectal and skin temperatures were measured at 0800 h, 1200 h, and 1600 h. Data were analyzed with PROC MIXED and GLIMMIX procedure for Generalized Linear Mixed Models. Ambient temperature ranged from 16 to 25 degrees C (average temperature humidity index 65.7 +/- 1.4). Five horses preferred the closed shelter and were observed inside up to 2.5 h continuously. Greater wind speed decreased the likelihood of observing horses inside the shelter (P < 0.001), as did lower numbers of flies (P < 0.001). The insect-defensive behaviors, skin shiver and ear flick, were performed less frequently when horses were using the closed shelter (P < 0.001), indicating that they were less disturbed by insects. Thirty-minute shelter use had no effect on rectal and skin temperatures (P > 0.05). Results showed that horses made use of shelters during the summer even when weather conditions were moderate. A shelter with roof and covers on 3 sides was preferred over a shelter with roof only and can reduce insect-defensive behavior.
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| 23. |
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| 24. |
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| 25. |
- Lundqvist, Johan, et al.
(author)
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Assessment of pesticides in surface water samples from Swedish agricultural areas by integrated bioanalysis and chemical analysis
- 2019
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In: Environmental Sciences Europe. - : Springer Science and Business Media LLC. - 2190-4715 .- 2190-4707. ; 31
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Journal article (peer-reviewed)abstract
- Background Pesticide residue contamination of surface water in agricultural areas can have adverse effects on the ecosystem. We have performed an integrated chemical and bioanalytical profiling of surface water samples from Swedish agricultural areas, aiming to assess toxic activity due to presence of pesticides. A total of 157 water samples were collected from six geographical sites with extensive agricultural activity. The samples were chemically analyzed for 129 commonly used pesticides and transformation products. Furthermore, the toxicity was investigated using in vitro bioassays in the water samples following liquid-liquid extraction. Endpoints included oxidative stress response (Nrf2 activity), estrogen receptor (ER) activity, and aryl hydrocarbon receptor (AhR) activity. The bioassays were performed with a final enrichment factor of 5 for the water samples. All bioassays were conducted at non-cytotoxic conditions. Results A total of 51 pesticides and transformation products were detected in the water samples. Most of the compounds were herbicides, followed by fungicides, insecticides and transformation products. The highest total pesticide concentration in an individual sample was 39 mu g/L, and the highest median total concentration at a sample site was 1.1 mu g/L. The largest number of pesticides was 31 in a single sample. We found that 3% of the water samples induced oxidative stress response, 23% of the samples activated the estrogen receptor, and 77% of the samples activated the aryl hydrocarbon receptor. Using Spearman correlation coefficients, a statistically significant correlation was observed between AhR and ER activities, and AhR activity was strongly correlated with oxidative stress in samples with a high AhR activity. Statistically significant relationships were observed between bioactivities and individual pesticides, although the relationships are probably not causal, due to the low concentrations of pesticides. Co-occurrence of non-identified chemical pollutants and naturally occurring toxic compounds may be responsible for the induced bioactivities. Conclusions This study demonstrated that integrated chemical analysis and bioanalysis can be performed in water samples following liquid/liquid extraction with a final enrichment factor of 5. AhR and ER activities were induced in water samples from agricultural areas. The activities were presumably not caused by the occurrence of pesticides, but induced by other anthropogenic and natural chemicals.
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