400 research outputs found

    Multicenter-study of operative treatment of intraligamentous tears of the anterior cruciate ligament in children and adolescents: Comparison of four different techniques

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    Tears of the anterior cruciate ligament in skeletally immature patients were operated with four different methods and their outcome compared to each other. Sixty-eight patients (33 males, 35 females), mean 12.5years, were treated in four different centers from 1984 to 2001. Twenty-eight patients underwent the ACL-reconstruction with hamstring grafts, 16 patients with bone-patella-bone autografts, 12 patients with quadriceps grafts and 12 patients with facia lata. The mean follow-up was 32months. Postoperative evaluation included radiographs, KT-1000/2000 stability measurements, Lysholm score, The Tegner activity scale and IKDC score. Neither leg length discrepancy nor angular deformities were noted. Mean KT-1000 difference was 2.1mm, mean postoperative Lysholm knee score 93.3, IKDC 87% normal or nearly normal. The Tegner index decreased from 6.6 to 5.7. In total, six patients developed instability due to an adequate trauma 1year after the index operation. Two patients showed mild arthrotic changes. All but two patients were able to return to the same level of preoperative sports participation. None of the four methods studied showed major differences in outcome compared to the other. No growth disturbance could be note

    Improved modelling of atmospheric ammonia over Denmark using the coupled modelling system DAMOS

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    A local-scale Gaussian dispersion-deposition model (OML-DEP) has been coupled to a regional chemistry-transport model (DEHM with a resolution of approximately 6 km × 6 km over Denmark) in the Danish Ammonia Modelling System, DAMOS. Thereby, it has been possible to model the distribution of ammonia concentrations and depositions on a spatial resolution down to 400 m × 400 m for selected areas in Denmark. DAMOS has been validated against measured concentrations from the dense measuring network covering Denmark. Here measured data from 21 sites are included and the validation period covers 2–5 years within the period 2005–2009. A standard time series analysis (using statistic parameters like correlation and bias) shows that the coupled model system captures the measured time series better than the regional- scale model alone. However, our study also shows that about 50% of the modelled concentration level at a given location originates from non-local emission sources. The local-scale model covers a domain of 16 km × 16 km, and of the locally released ammonia (NH<sub>3</sub>) within this domain, our simulations at five sites show that 14–27% of the locally (within 16 km × 16 km) emitted NH<sub>3</sub> also deposits locally. These results underline the importance of including both high-resolution local-scale modelling of NH<sub>3</sub> as well as the regional-scale component described by the regional model. The DAMOS system can be used as a tool in environmental management in relation to assessments of total nitrogen load of sensitive nature areas in intense agricultural regions. However, high spatio-temporal resolution in input parameters like NH<sub>3</sub> emissions and land-use data is required

    Spatial and temporal variations in ammonia emissions – a freely accessible model code for Europe

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    Deriving a parameterisation of ammonia emissions for use in chemistry-transport models (CTMs) is a complex problem as the emission varies locally as a result of local climate and local agricultural management. In current CTMs such factors are generally not taken into account. This paper demonstrates how local climate and local management can be accounted for in CTMs by applying a modular approach for deriving data as input to a dynamic ammonia emission model for Europe. Default data are obtained from information in the RAINS system, and it is demonstrated how this dynamic emission model based on these input data improves the NH<sub>3</sub> calculations in a CTM model when the results are compared with calculations obtained by traditional methods in emission handling. It is also shown how input data can be modified over a specific target region resulting in even further improvement in performance over this domain. The model code and the obtained default values for the modelling experiments are available as supplementary information to this article for use by the modelling community on similar terms as the EMEP CTM model: the GPL licencse v3

    Apparent Temperature and Cause-Specific Emergency Hospital Admissions in Greater Copenhagen, Denmark

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    One of the key climate change factors, temperature, has potentially grave implications for human health. We report the first attempt to investigate the association between the daily 3-hour maximum apparent temperature (Tappmax) and respiratory (RD), cardiovascular (CVD), and cerebrovascular (CBD) emergency hospital admissions in Copenhagen, controlling for air pollution. The study period covered 1 January 2002−31 December 2006, stratified in warm and cold periods. A case-crossover design was applied. Susceptibility (effect modification) by age, sex, and socio-economic status was investigated. For an IQR (8°C) increase in the 5-day cumulative average of Tappmax, a 7% (95% CI: 1%, 13%) increase in the RD admission rate was observed in the warm period whereas an inverse association was found with CVD (−8%, 95% CI: −13%, −4%), and none with CBD. There was no association between the 5-day cumulative average of Tappmax during the cold period and any of the cause-specific admissions, except in some susceptible groups: a negative association for RD in the oldest age group and a positive association for CVD in men and the second highest SES group. In conclusion, an increase in Tappmax is associated with a slight increase in RD and decrease in CVD admissions during the warmer months

    Apparent temperature and acute myocardial infarction hospital admissions in Copenhagen, Denmark: a case-crossover study

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    <p>Abstract</p> <p>Background</p> <p>The influence of temperature on acute myocardial infarction (AMI) has not been investigated as extensively as the effects of broader outcomes of morbidity and mortality. Sixteen studies reported inconsistent results and two considered confounding by air pollution. We addressed some of the methodological limitations of the previous studies in this study.</p> <p>Methods</p> <p>This is the first study of the association between the daily 3-hour maximum apparent temperature (Tapp<sub>max</sub>) and AMI hospital admissions in Copenhagen. The study period covered 1 January 1999-31 December 2006, stratified in warm (April - September) and cold (October - March) periods. A case-crossover epidemiology study design was applied. Models were adjusted for public holidays and influenza, confounding by PM<sub>10</sub>, NO<sub>2 </sub>and CO was investigated, the lag and non-linear effects of Tapp<sub>max </sub>was examined, effect modification by age, sex and SES was explored, and the results of the case-crossover models were compared to those of the generalised additive Poisson time-series and generalised estimating equation models.</p> <p>Results</p> <p>14 456 AMI hospital admissions (12 995 people) occurred during the study period. For an inter-quartile range (6 or 7°C) increase in the 5-day cumulative average of Tapp<sub>max</sub>, a 4% (95% CI:-2%; 10%) and 9% (95% CI: 3%; 14%) decrease in the AMI admission rate was observed in the warm and cold periods, respectively. The 19-65 year old group, men and highest SES group seemed to be more susceptible in the cold period.</p> <p>Conclusion</p> <p>An increase in Tapp<sub>max </sub>is associated with a decrease in AMI admissions during the colder months.</p

    Konsekvenser for emissioner og luftkvalitet af tiltag på transportområdet i Regeringens klima- og luftudspil

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    Regeringens klima- og luftudspil (”Sammen om en grønnere fremtid”) indeholder en beskrivelse af 38 initiativer rettet mod at reducere udledningen af drivhusgasser og/eller luftforurening. DCE - Nationalt Center for Miljø og Energi under Aarhus Universitet har gennemgået de 38 initiativer med henblik på en vurdering af hvilke af disse initiativer, der har indflydelse på luftforureningen i 2030, samt den forventede størrelse af den reducerende effekt. DCE har kvantificeret effekten af følgende initiativer og benævnt det klimascenariet: (1) Stop for salg af nye benzin- og dieselbiler i 2030 og for nye plug-in hybridbiler fra 2035, (2) Slut med udledning af CO2 og luftforurening fra busser i byerne fra 2030, (3) Benzin og diesel skal ud af taxidriften inden 2030, (4) Gamle brændeovne skrottes ved ejerskifte, og (5) Skrotpræmie til gamle brændeovne. Artiklen fokuserer på de tre virkemidler rettet mod vejtransportsektoren og sammenligner med den eksisterende basisemissionsfremskrivning for vejtrafik i Danmark i 2030, og effektvurderer scenarierne mht. til emission og luftkvalitet.&nbsp; Den største emissionsbesparelse opnås i Scenarie 1 (1 mio. elbiler), og emissions-reduktionerne for hele vejtrafikken i 2030 bliver på hhv. 13 %, 17 % og 2,1 % for NOx, PM2,5–udstødning og PM2,5–samlet (udstødning og ikke-udstødning). Hvis alle tre scenarier indføres bliver emissionsreduktionerne for NOx og PM2,5 –udstødning og PM2,5 –samlet (udstødning og ikke-udstødning) hhv. 15 %, 19 % og 2,3 %.&nbsp; Effekten af klimascenariet er vurderet for luftkvaliteten på 98 gader i København i 2030 ved beregninger af ændringer i den regionale baggrund, bybaggrund og gadekoncentrationer. Basisudviklingen fra 2016 til 2030 viser et stort fald i koncentrationerne, og klimascenariet bidrager til et yderligere mindre fald. Effekten af klimascenariet for reduktion af NO2 gadekoncentrationerne er især bestemt af reduktionen i trafikkens emissioner, mens de mindre reduktioner af PM2,5 og PM10 i højere grad er bestemt af reduktioner i emissioner fra brændeovne end fra trafik.&nbsp
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