118,557 research outputs found
The future water supply of Växjö municipality – evaluation of different alternatives
No full textThe water supply in Växjö municipality has since 1887 been based on surface water from Lake Helgasjön. A water treatment plant was built in 1957 and was extensively reconstructed in 1969 but there are still problems to accomplish with drinking water quality, mainly related to temperature, smell and taste, manganese and aluminium rest. The present water consumption has periodically approached the water treatment plant maximum capacity. A performed risk analysis showed that catastrophic consequences for the water supply could occur due to an accident in a nearby traffic route or discharges from an industrial area. In 1997 Växjö municipality decided to perform a comprehensive investigation of different alternatives for future water supply. Seven alternatives were evaluated including remedial measures at the present water treatment plant. The chosen alternative was based on supply and conveying ground water from the Berga Esker in Ljungby municipality. Re-infiltration of ground water will be used to guarantee the required water quality and quantity and will be implemented in autumn 2008 with a planned supply of 200 l per second delivered to about 70,000 persons in the municipalities of Växjö and Alvesta. The article describes the different alternatives, motives for the chosen alternative and the evaluation procedure.This paper is an English translation of: Al-Najjar, N. (2007). Framtida vattenförsörjning för Växjö kommun – bedömning av olika alternativ, Vatten, 63:4, 299-311.</p
Tobacco smoking and the risk of gallbladder disease
No full textTobacco smoking has been inconsistently associated with gallbladder disease risk. To clarify the association we conducted a systematic review and meta-analysis of cohort studies published on the subject. We searched the PubMed and Embase databases for studies of smoking and gallbladder disease up to January 9th 2015. Prospective studies were included if they reported relative risk estimates and 95 % confidence intervals of gallbladder disease associated with current, former or ever smoking and by number of cigarettes per day. Summary relative risks were estimated by use of a random effects model. We identified ten prospective studies including 59,530 gallbladder disease cases among 4,213,482 participants that could be included in the meta-analysis. The summary RR was 1.19 (95 % CI 1.12–1.28, I2 = 46.9 %, n = 6) for current smokers, 1.10 (95 % CI 1.07–1.13, I2 = 0 %, n = 6) for former smokers and 1.15 (95 % CI 1.13–1.18, I2 = 0 %, n = 7) for ever smokers. In the dose–response analysis the summary relative risk was 1.11 (95 % CI 1.08–1.14, I2 = 33 %, n = 3) per 10 cigarettes per day and although there was indication of nonlinearity there was a dose-dependent positive association with increasing number of cigarettes smoked per day. The current meta-analysis provides evidence of an increased risk of gallbladder disease associated with tobacco smoking
Screening of PFASs in groundwater andsurface water
No full textLevels of 26 per- and polyfluoroalkyl substances (PFASs) were measured in 502 water samples originat-ing from Swedish groundwater, surface water, sewage treatment plant (STP) effluents and landfill leachates. In drinking water source areas, the average Σ26PFAS concentration was 8.4 ng L-1. The national drinking water guideline value of 90 ng L-1 for Σ7PFASs was exceeded in 2% of these samples. In water not used for drinking water, Σ26PFASs average concentration was 142 ng L-1. PFOS concentra-tions exceeded the Annual Average Environmental Quality Standard (AA-EQS) of the EU Water Frame-work Directive in 42% of the surface water samples. Among the different water categories, the landfill leachates had the highest average concentration of Σ26PFAS with 487 ng L-1, followed by surface water (average 112 ng L-1), groundwater (49 ng L-1), STP effluents (35 ng L-1) and background screening lakes (3.4 ng L-1). The composition profile of the PFASs differed between the types of waters showing an even distribution of ΣPFCAs, ΣPFSAs and ΣPFAS precursors in groundwater, whereas in all other water categories, ΣPFCAs were dominant. As FOSA, PFNA, PFDA, and 6:2 FTSA were frequently detected in drinking water source areas (constituted 20%, 7.3%, 5.9%, and 4.4% of the Σ26PFASs, respectively), it is reasonable to consider the inclusion of these in the Swedish drinking water guideline.Per- och polyfluoralkylerade ämnen (PFASs) är relativt nya organiska miljöförore-ningar som kännetecknas av att många av dem är långlivade, bioackumulerar och är toxiska. I den här studien analyserades 26 olika PFASs i 502 svenska vattenpro-ver av olika ursprung: grundvatten, ytvatten, avloppsvatten från reningsverk (STP) och lakvatten från deponier. Syftet med studien var att fastställa bakgrundskoncent-rationer av PFASs i den svenska vattenmiljön, identifiera PFAS källor samt jäm-föra PFAS-koncentrationer med riktvärden för bedömning av risker för ekosystem och människors hälsa. I källområden för dricksvatten var den genomsnittliga kon-centrationen av Σ26PFAS 8,4 ng L-1, med ett medianvärde på 0,6 ng L-1 (n = 172). Livsmedelsverkets rekommenderade gränsvärde för Σ7PFASs (PFPeA, PFHxA, PFHpA, PFOA, PFBS, PFHxS, PFOS) i dricksvatten (90 ng L-1) överskreds i 4 prover (2% av proverna för denna typ av vatten). I vatten som inte kom från käll-områden för dricksvatten var Σ26PFAS koncentrationerna högre med ett medel-värde på 142 ng L-1 och medianvärde på 5,4 ng L-1. Den höga medelkoncentration-en kan förklaras av att vissa prover hade extremt höga PFAS halter med ett topp-värde på 12 900 ng L-1. För substansen PFOS finns en miljökvalitetsnorm i EU:s ramdirektiv för vatten (vattendirektivet) som avser årsmedelvärde (AA-MKN). Denna norm överskreds i 42% av ytvattenproverna. Bland de olika vattenkategori-erna hade lakvatten den högsta genomsnittliga Σ26PFAS-koncentrationen (487 ng L-1, median 435 ng L-1, n = 10), följt av ytvatten (medel 112 ng L-1, median 4,1 ng L-1, n = 285), grundvatten (medel 49 ng L-1, median 0,4 ng L-1, n = 164), STP av-lopssvatten (medel 35 ng L-1, median 26 ng L-1, n = 13) och bakgrundsjöar (avläg-set belägna screening-sjöar, medel 3,4 ng L-1, median 1,4 ng L-1, n = 10). PFASs kan indelas i olika ämnesgrupper, t.ex. ΣPFCAs, ΣPFSAs och ΣPFAS-prekursorer. Sammansättningen av PFASs skilde sig mellan olika typer av vatten. Grundvattnen hade en jämn fördelning mellan dessa ämnesgrupper, medan i alla andra prover (ytvatten, bakgrundssjöar, STP avloppsvatten och lakvatten) dominerade ΣPFCAs. Eftersom FOSA, PFNA, PFDA och 6:2 FTSA ofta detekterades i vatten från käll-områden till dricksvatten (utgjorde 20%, 7,3%, 5,9% respektive 4,4% av Σ26PFASs) kan man överväga att inkludera dessa i det rekommenderade svenska gränsvärdet.Regeringsuppdrag: Screening av förekomsten av miljögifte
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
HOME Vatten i Bottenhavets vattendistrikt. Integrerat modellsystem för vattenkvalitetsberäkningar
No full textSMHI har utvecklat ett interaktivt modellsystem för vattenkvalitetberäkningar i mark, sjöar,vattendrag och kustvatten, HOME Vatten. I detta uppdrag har HOME Vatten implementerats iBottenhavets vattendistrikt, dvs. i Västerbotten, Jämtland, Västernorrland, Dalarna, Gävleborg ochUppsala län. De ingående modellerna i HOME Vatten är HBV-NP (PLC5-uppsättningen) modellenför mark, sjöar och vattendrag samt Kustzonsmodellen för kustvattnen. Atmosfärsdepositionenbåde på land och i kustområdet beräknas av den atmosfärskemiska MATCH-modellen.HOME Vatten har utvecklats för att vara ett verktyg i svensk vattenförvaltning med speciellt fokuspå EUs ramdirektiv för vatten.Modelluppsättningarna i Västerbotten, Västernorrland och Gävleborg läns kustvatten harvaliderats mot tillgängliga mätdata, och visar en god överrensstämmelse med data
Screening efter ftalatersättare och antioxidanter/stabilisatorer i reningsverksslam och -vatten
No full textFörekomsten av ftalatersättare och antioxidanter/stabilisatorer undersöktes i utgående vatten och slam från nio svenska avloppsreningsverk (ARV); Stockholm (Henriksdal), Göteborg (Ryaverket), Umeå (Ön), Borås (Sobacken), Eslöv (Ellinge), Alingsås (Nolhaga), Bollebygd, Borlänge och Bergkvara (Torsås). Följande ämnen har ingått i studien: Sju ftalatersättare (dioktyl adipat (DOA), di-iso-nonyl adipat (DINA), dietylen glycol dibensoat (DEGDB), dipropylen glycol dibensoat (DPGDB), 2,2,4-trimetyl-1,3 pentanediol di-isobutyrat (TXIB), bensyl 3-isobutyryloxi-1-isopropyl-2,2-dimetylpropyl ftalat (Santicizer 278) och tris-2-etylhexyl trimellitat (TOTM)) och fyra antioxidanter/ stabilisatorer (2,2′,6,6′-tetra-tert-butyl-4,4’-metylen-difenol, difenyl(2,4,6-trimetylbensoyl)fosfin oxid (TOP), 4-tert-butylpyrocatekol och 6,6'-di-tert-butyl-4,4'-tiodi-m-cresol). Endast två av de sju undersökta ftalatersättarna, dioctyl adipat (DOA) och 2,2,4-trimetyl-1,3-pentanediol di-isobutyrat (TXIB), kunde detekteras i utgående vatten. De förekom i ungerfär samma halt (DOA, 18-117 ng/L; TXIB, 48-113 ng/L). Fyra av de sju ftalatersättarna detekterades i reningsverksslam, i samtliga slamprover. Förutom de två som detekterats i utgående vatten (DOA och TXIB) detekterades dietylen glykol dibensoat (DEGDB) och dipropylen glykol dibensoat (DPGDB). DPGDB förekom i högst halter (20-389 μg/kg torrsubstans, TS) följt av DOA (13-82 μg/kg TS), DEGDB (4.6-30 μg/kg TS) och TXIB (1.1-4.9 μg/kg TS). Halterna av samtliga ftalatersättare var långt under (ca. 1000 gånger) halterna av 2-dietylhexyl ftalat (DEHP) i de aktuella slamproverna. Ingen av de analyserade antioxidanterna/stabilisatorerna kunde detekteras i utgående vatten eller slam från de undersökta avloppsreningsverken
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Flagellaten Euglena gracilis rörelseförmåga kan avslöja graden av giftighet (kadmium) i vatten med hjälp av metoden ECOTOX. (Orientation of the flagellate Euglena gracilis can identify the toxicity (cadmium) of water using the automatic biotest ECOTOX)
No full textThe interest in testing of water and wastewater for toxic compounds has increased in the last few years with rising pollutant levels from industry and with rising sensibility towards environmental problems. In order to get an early warning signal of environmental conditions the use of unicellular organism are recommended since they respond quickly and are easy to handle. An early warning system, called ECOTOX, for monitoring of water quality has been developed by a research group in Germany (Prof. D.-P. Häder). ECOTOX use movement parameters of the flagellate Euglena gracilis as orientation in the gravity field, the motility and the velocity of the cells. These parameters have been found to be sensitive to toxic compounds. In the present study it was shown that cadmium affect gravitaxis, motility, velocity and compactness of the cells negatively in the concentration interval of 10 to 15 mg l-1 after 24 and 48 h. After short time of incubation (minutes) with cadmium there is an inhibition of the different movements parameters starting at the concentration of 25 mg l-1. Like other biomonitoring systems ECOTOX can be used to detect changes in quality of aquatic systems.</p
A cross-sectional study of cardiovascular disease and associated factors
No full textObjective: Cardiovascular diseases (CVD) are a major cause of mortality and morbidity in Poland. Data on risk factors of CVD in this country are limited. The presented study investigated risk factors of self-reported CVD within the Polish- Norwegian Study (PONS). Methods: PONS is an ongoing prospective study in Poland. The data used was provided by 3,853 participants, aged 45-64, during baseline interviews. Results: Prevalence of chronic diseases among participants was as follows: hypertension, 38.4%; diabetes, 5.9%; and CVD, 11.0%. There was no association between CVD and gender and place of residence. CVD was associated with ever-smoking (OR= 1.25; 95% CI: 1.00-1.55), whereas there was an inverse association with alcohol drinking in the year preceding enrolment in the study (OR= 0.50; 95% CI: 0.39-0.63). CVD was associated with body mass index (BMI), as well as with measures of abdominal adiposity, in the following order: waist to height ratio>waist circumference>waist to hip ratio; however, none of these measures showed a stronger association with CVD than BMI. Both hypertension (OR= 1.33; 95% CI: 1.05-1.68) and diabetes (OR= 1.33; 95% CI: 1.05-1.68) were associated with CVD in adjusted models. Conclusions: This study shows the association between several risk factors and prevalence of self-reported CVD and provides information about distribution of those factors among an adult population in Poland. The results of the ongoing PONS study in a prospective setting will provide more accurate risk estimates for the observed associations, as well as risk estimates for other risk factors of CVD, including dietary factors, and attributable risks for various factors
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