| 1. |
- Wallin, Kjell, et al.
(författare)
-
Skattning av antalet kornknarrar på Öland 2008
- 2008
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten redovisar resultatet av en inventering vars syfte var att beräkna det totala antalet spelande kornknarrar på Öland och att beskriva de spelande hanarnas uppehållsmiljö. Inventeringen genomfördes med stratifierad stickprovtagning av 300 provpunkter jämnt fördelade över hela Öland under perioden maj – juli 2008, där varje punkt besöktes minst två gånger. Bandspelare som spelade upp kornknarrens läte användes för att öka chansen att upptäcka kornknarr. Metoden innebar dock ingen större förbättring. Som metod för att beräkna antalet spelande hanar har avståndsinventering använts från utvalda punkter. Bestämning av kornknarrarnas position har gjorts genom ”triangulering”. Skattningen av det maximala antalet spelande kornknarrar är 206 stycken. Genom skillnaden i uppträdande och antal, mellan första och andra inventeringstillfället, med 147 respektive 61 hanar, antyds att denna siffra kan vara en överskattning. En vidare diskussion av detta görs i rapporten. Geografiskt har kornknarren sin tyngdpunkt på mellersta och östra Öland. Uppehållsmiljön utgjordes till större delen av vall, betesmark och träda, vilket överensstämmer med tidigare gjorda studier på Öland. En jämförelse mellan rapporteringssystemet Svalan och skattning genom stickprovstagning visar på relativt stora skillnader i antal spelande kornknarrar, både tidsmässigt och geografiskt. Antalet kornknarrar som rapporteras till Svalan avtar från mitten av juni medan inventeringen visar att spelandet fortsätter med bibehållen intensitet in i juli. Observationerna från Svalan är koncentrerade till Ölands sydöstra delar medan observationerna från inventeringen är mer jämnt fördelade över ön, även om det finns en viss östlig förtätning.
|
|
| 2. |
- Wallin, Mats, et al.
(författare)
-
Fågelfaunan på Ölands sjömarker - inventeringar 1988-2008
- 2009
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Fåglarna på Ölands sjömarker har varit föremål för tre heltäckande inventeringar under de senaste 20 åren. Dessutom har delar av Öland inventerats årligen sedan 2003. För ändamålet är Ölands sjömarker indelade i 96 delområden. De artgrupper som inventerats är ”Vadare”, ”Änder, svanar och gäss” samt ”Tärnor och måsfågel”. Vid inventeringarna har antalet häckande par bedömts genom parräkning, boräkning och revirkartering. Vid sidan av fågelinventeringen har även hävden på sjömarkerna bedömts av inventerarna. Resultaten från inventeringarna har analyserats med syfte att beskriva enskilda fågelarters populationsutveckling på Öland som helhet och i respektive delområde. Dataunderlaget för hela perioden, 1988–2008, är ojämnt då fler inventeringar gjorts efter 2000. Därför har utvärderingen av arternas trender i första hand baserats på perioden 1998–2008. Utvecklingen är positiv för 14 arter medan sju arter visar en negativ utveckling. Skillnaden mellan artgrupperna är påtaglig. Änder, svanar och gäss ökar medan vadare i huvudsak uppvisar en negativ utveckling. Arter som ökar är silvertärna, skrattmås, sothöna, storskrake, vigg, grågås, gravand, knölsvan, skedand, snatterand, kricka, gräsand, större strandpipare och tofsvipa. Arter som minskar är ejder, kanadagås, strandskata, rödspov, ljungpipare, brushane och sydlig kärrsnäppa. Sett över hela perioden, 1988–2008, är förändringarna så stora att de med säkerhet kan utläsas för ytterligare några arter. Det är för havstrut och vitkindad gås som ökat medan silltrut, svärta, stjärtand, storspov och roskarl minskat. Arter som svärta, strandskata, sydlig kärrsnäppa, brushane, ljungpipare och rödspov ser ut att vara på väg att försvinna. Hävden på Ölands sjömarker har ökat under de senaste 20 åren. Relationen mellan hävden och antalet häckande vadare är svagt positiv och en stark hävd behöver inte betyda många vadare. Hävden är nödvändig i förvaltningen av av sjömarkerna men andra faktorer har förmodligen ett starkare inflytande på vadarnas populationsutveckling.
|
|
| 3. |
- Ahlm, Clas, 1956-, et al.
(författare)
-
Serologic evidence of Puumala virus infection in wild moose in northern Sweden
- 2000
-
Ingår i: American Journal of Tropical Medicine and Hygiene. - : American Society of Tropical Medicine and Hygiene. - 0002-9637 .- 1476-1645. ; 62:1, s. 106-111
-
Tidskriftsartikel (refereegranskat)abstract
- Puumala (PUU) virus is the causative agent of nephropathia epidemica, the Scandinavian form of hemorrhagic fever with renal syndrome. The infection is acquired by airborne transmission of PUU virus from its rodent reservoir, the bank vole. Besides serologic data indicating that the virus may spread also to heterologous rodents, there is little information on the susceptibility of wild living animals to PUU virus. We studied the occurrence of antibodies to PUU virus in serum samples from 427 wild-living moose, of which 260 originated from the PUU virus-endemic northern and central parts of Sweden and 167 originated from the southern, nonendemic part of Sweden. Samples from 5 animals showed reactivity in an ELISA for recombinant PUU virus nucleocapsid protein, an immunofluorescent assay, and a neutralization test. These 5 animals all originated from the PUU virus-endemic northern part of Sweden. In conclusion, 5 of 260 moose from the endemic region showed convincing serologic evidence of past PUU virus infection. The seroprevalence was low, suggesting that the moose is subjected to endstage infection rather than being part of an enzootic transmission cycle.
|
|
| 4. |
- Andersson, Daniel, et al.
(författare)
-
M-Sequence UWB Radar for Industrial Applications
- 2010
-
Ingår i: Program of GigaHertz Symposium 2010, March 9-10, at Lund University.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Ultra Wideband Radar has the potential of dramatically improving the control and surveillance of industrial processes in confined areas. An example is the application of UWB radar for surveillance of furnaces for heath treatment of steel billets developed by Radarbolaget in Gävle. In our installation at AB Sandvik Materials Technology, we have shown that by using a non-destructive UWB Radar technique it is possible to visualize in real-time the ongoing process inside the furnace behind a 0.5 m thick ceramic wall. Since the operating temperature inside the furnace is 1200 °C, there is today no other known method capable of visualizing the process for the operator of the furnace. The system is therefore designed to sustain high temperatures and powerful electromagnetic disturbances while performing measurement with wide dynamics and high stability. The design of this radar is based on the idea of transmitting a continuous m-sequence and then detecting the correlated impulse response (see figure below). The wide bandwidth is a requirement for obtaining high spatial accuracy and resolution but puts further requirements on the design of the antennas and the electronics. Our results show that with this technique it is possible to determine the deformation of the steel billets inside the furnace with an accuracy of less than 5 mm. The radar system is also able to detect deformations in the furnace wall The m-sequence radar has many advantages over other UWB radar technologies since it e.g. does not require many analogue components. Its performance is a result of the choice of code length, sampling rate and averaging. However, the resolution is still limited by the impulse response of the analogue antenna (ringing). In this paper system parameters that affect the overall performance of an m-sequence radar are reviewed and means of enhancing its performance are discussed.
|
|
| 5. |
- Asplund, Kjell, et al.
(författare)
-
The Riks-Stroke story : building a sustainable national register for quality assessment of stroke care
- 2011
-
Ingår i: International Journal of Stroke. - : SAGE Publications. - 1747-4930 .- 1747-4949. ; 6:2, s. 99-108
-
Tidskriftsartikel (refereegranskat)abstract
- Background Riks-Stroke, the Swedish Stroke Register, is the world's longest-running national stroke quality register (established in 1994) and includes all 76 hospitals in Sweden admitting acute stroke patients. The development and maintenance of this sustainable national register is described. Methods Riks-Stroke includes information on the quality of care during the acute phase, rehabilitation and secondary prevention of stroke, as well as data on community support. Riks-Stroke is unique among stroke quality registers in that patients are followed during the first year after stroke. The data collected describe processes, and medical and patient-reported outcome measurements. The register embraces most of the dimensions of health-care quality (evidence-based, safe, provided in time, distributed fairly and patient oriented). Result Annually, approximately 25 000 patients are included. In 2009, approximately 320 000 patients had been accumulated (mean age 76-years). The register is estimated to cover 82% of all stroke patients treated in Swedish hospitals. Among critical issues when building a national stroke quality register, the delicate balance between simplicity and comprehensiveness is emphasised. Future developments include direct transfer of data from digital medical records to Riks-Stroke and comprehensive strategies to use the information collected to rapidly implement new evidence-based techniques and to eliminate outdated methods in stroke care. Conclusions It is possible to establish a sustainable quality register for stroke at the national level covering all hospitals admitting acute stroke patients. Riks-Stroke is fulfilling its main goals to support continuous quality improvement of Swedish stroke services and serve as an instrument for following up national stroke guidelines.
|
|
| 6. |
- Asplund, Kjell, et al.
(författare)
-
Use of public transport by stroke survivors with persistent disability
- 2012
-
Ingår i: Scandinavian Journal of Disability Research. - : Stockholm University Press. - 1501-7419 .- 1745-3011. ; 14:4, s. 289-299
-
Tidskriftsartikel (refereegranskat)abstract
- Use of public transport (bus, train, air, ship) by persons disabled after stroke is an expression of autonomy and facilitates social interactions. Based on Riks-Stroke, the Swedish stroke register, 882 persons with persistent, moderate or severe physical disability (mean age 71 years) responded to a questionnaire 12-28 months after stroke. A minority of the respondents had travelled by bus (21%), train (9%), air (14%) or ship (12%) during the last year. Barriers perceived by persons that had abstained from travelling were dominated by physical constraints, but there were also frequent cognitive constraints. Fear of travelling was not perceived as a major constraint. The majority of persons who had actually used public transport did not report any negative experiences. Air and ship journeys were generally perceived as somewhat less troublesome than journeys by bus or train. Thus, public transport is used infrequently in people moderately or severely disabled after stroke. Anticipated cognitive constraints contribute importantly to non-use of public transport. Disabled stroke survivors who have not used public transport may overestimate the actual barriers to use of public transport.
|
|
| 7. |
- Basile, Anna Maria, et al.
(författare)
-
Age, hypertension, and lacunar stroke are the major determinants of the severity of age-related white matter changes
- 2006
-
Ingår i: CEREBROVASCULAR DISEASES. - : S. Karger AG. - 1015-9770 .- 1421-9786. ; 21:5-6, s. 315-322
-
Tidskriftsartikel (refereegranskat)abstract
- <i>Background:</i> Age-related white matter changes (ARWMC), seen on neuroimaging with high frequency in older people, are thought to be consequent to the effect of vascular risk factors and vascular diseases including hypertension and stroke. Among the proofs conventionally required for a factor to be considered a risk factor for a definite pathology, there is the demonstration of a trend in risk exposure related to disease severity. We sought whether such a trend existed in the association of vascular risk factors or comorbidities with the severity of ARWMC aiming particularly at further elucidating the relative roles of hypertension and stroke in this regard. <i>Methods:</i> The LADIS (Leukoaraiosis and Disability) Study is evaluating the role of ARWMC as an independent determinant of the transition to disability in the elderly. Six hundred and thirty-nine nondisabled subjects (mean age 74.1 ± 5.0, M/F: 288/351) with ARWMC of different severity grades on MRI (mild, moderate, or severe according to the Fazekas scale) were assessed at baseline for demographics, vascular risk factors, and comorbidities, and are being followed up for 3 years. <i>Results:</i> Age, frequency of hypertension and history of stroke increased along with increasing ARWMC severity independently of other factors. For hypertension, however, this occurred only in subjects without a stroke history, while for stroke history, it mainly depended on lacunar stroke. The amount of cigarettes smoked and the interaction between hypercholesterolemia and smoking predicted only the most severe ARWMC grade. <i>Conclusions:</i> The LADIS Study confirms that age, hypertension and lacunar strokes are the major determinants of ARWMC. Smoking and hypercholesterolemia provide additional risk.
|
|
| 8. |
- Basile, Anna Maria, et al.
(författare)
-
Age, hypertension, and lacunar stroke are the major determinants of the severity of age-related white matter changes. The LADIS (Leukoaraiosis and Disability in the Elderly) Study.
- 2006
-
Ingår i: Cerebrovasc Dis. - : S. Karger AG. - 1015-9770 .- 1421-9786. ; 21:5-6, s. 315-22
-
Tidskriftsartikel (refereegranskat)abstract
- <i>Background:</i> Age-related white matter changes (ARWMC), seen on neuroimaging with high frequency in older people, are thought to be consequent to the effect of vascular risk factors and vascular diseases including hypertension and stroke. Among the proofs conventionally required for a factor to be considered a risk factor for a definite pathology, there is the demonstration of a trend in risk exposure related to disease severity. We sought whether such a trend existed in the association of vascular risk factors or comorbidities with the severity of ARWMC aiming particularly at further elucidating the relative roles of hypertension and stroke in this regard. <i>Methods:</i> The LADIS (Leukoaraiosis and Disability) Study is evaluating the role of ARWMC as an independent determinant of the transition to disability in the elderly. Six hundred and thirty-nine nondisabled subjects (mean age 74.1 ± 5.0, M/F: 288/351) with ARWMC of different severity grades on MRI (mild, moderate, or severe according to the Fazekas scale) were assessed at baseline for demographics, vascular risk factors, and comorbidities, and are being followed up for 3 years. <i>Results:</i> Age, frequency of hypertension and history of stroke increased along with increasing ARWMC severity independently of other factors. For hypertension, however, this occurred only in subjects without a stroke history, while for stroke history, it mainly depended on lacunar stroke. The amount of cigarettes smoked and the interaction between hypercholesterolemia and smoking predicted only the most severe ARWMC grade. <i>Conclusions:</i> The LADIS Study confirms that age, hypertension and lacunar strokes are the major determinants of ARWMC. Smoking and hypercholesterolemia provide additional risk.
|
|
| 9. |
- Birgersson, Björn
(författare)
-
Maternal investment in male and female offspring in the fallow deer
- 1997
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, I investigate whether mothers of the polygynous fallow deer, Dama dama, bias their investment towards male offspring. I aim to answer the specific questions: (i) how is offspring fitness related to maternal investment?; (ii) do male fawns grow faster than female fawns during the period of maternal investment, and if so, why?; (iii) are male fawns more costly to raise than female fawns?; (iv) do fallow deer mothers adjust the sex of their offspring in relation to their ability to invest resources? To answer these questions I have collected and analysed data on reproduction of an enclosed fallow deer population and also performed an experimental study in which the level of investment was controlled for.Heavier mothers gave birth earlier and to larger offspring which grew at a faster rate. Pre-winter body mass of fawns was also found to affect sub-adult body mass in both sexes indicating that maternal investment influences offspring adult body size and, presumably, their fitness. The effect of pre-winter body mass on sub-adult body mass was stronger in male than in female fawns. Male pre-winter body mass was also constantly higher than female pre-winter body mass. Presumably, this is because male reproductive success varies more with body size than does female reproductive success and, hence, there has been stronger selection for early growth in males than in females. Male fawns grew faster than female fawns both before and after birth, independent of their birth date, but there were no behavioral differences between the two sexes. Furthermore, the faster male growth could not be explained by mothers in better condition (heavier mothers) producing male offspring and mothers in poorer condition producing females.When male and female fawns were given exactly the same amount and quality of milk by bottle-raising them, the difference in weight gain between bottle- and mother raised male fawns was significantly larger than between bottle- and mother-raised female fawns during the time when they solely consumed milk. It was also evident that bottle-raised male fawns suck harder and acquired milk at a more rapid rate than female fawns. These results suggest that male fawns receive more milk from their mothers than female fawns do.Mothers with sons accumulated less body mass than mothers with daughters during the period from late pregnancy to the end of lactation which gives additional support for the conclusion that male fawns receive more milk from their mothers. The higher energetic cost of raising a male was also translated into a higher reproductive cost, as indicated by later birth date and lower pre-winter mass of offspring the following year. Pre-winter body mass the first year is related to adult body mass and, most likely, to reproductive success in fallow deer. Consequently, the higher milk production and the corresponding higher energetic cost of raising sons do affect the mother's future offspring's chances to reproduce and, thus, support theories of male-biased maternal investment.
|
|
| 10. |
- Björner Brauer, Hanna, et al.
(författare)
-
Pain Relieving Light - (How) Is it Possible?
- 2024. - 1
-
Ingår i: IOP Science home Accessibility Help Journals Books Publishing Support Login IOP Conference Series: Earth and Environmental Science. - 1755-1307. ; 1320
-
Konferensbidrag (refereegranskat)abstract
- About 15% of the population suffer from migraines and it is estimated that about 40% of all people with migraines would benefit from preventive treatment, but only 3-13% use it. Migraine is a huge burden for society and individuals. Migraines can be intensified by light, and some patients need to stay in a dark room until the attack is over. People with this type of photosensitivity show a clear preference for light color, specifically green, which has been shown to be more comfortable and even pain relieving in some cases. We will present a feasibility study with the aim of preparing a series of experiments to investigate if regular short-term green-light-exposure can prevent migraines. We will present findings from the literature, developed light equipment, and plans for future testing of migraine friendly light solutions.
|
|
| 11. |
- Broman, Emil, et al.
(författare)
-
Fåglar, hävd och vätar - utvärdering av miljöövervakningen av fåglar på öländska strandängar
- 2011
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Årligen inventeras fåglar på Ölands sjömarker. Inventeringens syfte är att skatta antalet par av olika fågelarter knutna till sjömarkshabitatet. På uppdrag av länsstyrelsen i Kalmar län lämnar Svensk Naturförvaltning AB alternativa förslag på hur denna sjömarksinventering kan genomföras.Vi går igenom några alternativa inventeringsupplägg och utvärderar hur dessa påverkar säkerheten för att beräkna antalet fåglar på sjömarkerna och kostnaden för att få denna information.Med ett alternativt upplägg till dagens, är det möjligt att få tre gånger så mycket information om utvecklingen av antalet fåglar på sjömarkerna, till dagens budgetram. Detta innebär dock att man måste ge upp användandet av fasta inventeringslokaler. En kompromiss med delar av det nuvarande systemet och ett nytt system kan ge en fördubbling av informationen jämfört med idag. En sådan kompromiss skulle exempelvis kunna vara en årlig inventering av tio fasta sjömarker och 17-18 slumpade sjömarker. Detta skulle ge information motsvarande en totalinventering var femte år jämfört med dagens var tionde år.I rapporten redovisas också resultat från analyser där urvalet stratifierats utifrån storlek, naturskydd och inventeringsfrekvens. Som jämförelser presenteras skattningar baserade på enkelt stickprovsurval. Fåglarna har delats in i vadare, måsfåglar, simfåglar och tättingar. Ett stickprov på 20 sjömarker har dragits för respektive analys. Det bör understrykas att dessa avgränsningar även sätter gränsen för vilka tolkningar som kan göras av analysresultaten.Mönstret för hur skattningsprecisionen blir för olika urval av områden är generellt komplext och varierar mellan fågelgrupper och arter. Vadare har högst skattningsprecision när sjömarkerna delas upp i två storleksstrata med en brytpunkt runt 150 ha och med en större andel av stickprovet bland de mindre sjömarkerna. Denna stratifiering ger också hög precision för andra fågelgrupper, men är dock inte en optimal lösning.En uppdelning i sjömarker inom Natura 2000-områden och sådana utanför dessa områden ger ingen förbättrad precision.Att inventera några sjömarker varje år och årligen slumpa ett antal ger ingen vinst i skattningsprecision. Denna urvalsmodell kan dock ha ett visst värde genom att man kan få en mer detaljerad information om olika komponenter i mellanårsvariationen.Om länsstyrelsen väljer ett stratifierat urvalssystem rekommenderar vi ett storleksstratifierat urval för övervakning av sjömarkerna på Öland och att man inventerar en femtedel av alla sjömarker varje år i en cykel på fem år. Urvalet innebär en säkrare skattning av totalantalet fåglar och att de Öländska sjömarkerna följs upp med en fördubblad takt jämfört med idag och alltsammans till en mindre kostnad.
|
|
| 12. |
- Dahle, B., et al.
(författare)
-
Predation on adult moose Alces alces by European brown bears Ursus arctos
- 2013
-
Ingår i: Wildlife Biology. - : Wiley. - 0909-6396 .- 1903-220X. ; 19:2, s. 165-169
-
Tidskriftsartikel (refereegranskat)abstract
- Several North American studies have reported significant predation rates on moose Alces alces by brown bears Ursus arctos. We documented predation on moose by brown bears in south-central Sweden, where brown bears and moose occurred at estimated densities of 10-30 and 400-1,340/1,000 km(2), respectively. Bears killed 0.8% of radio-collared adult female moose (i.e. >= 1 year old) annually and no male moose (>= 1 year old). Bear predation was the least important mortality factor we documented. Based on tracking brown bears on snow during spring we recorded one successful hunt for every 372 km of tracks and documented attacks only by adult bears and successful attacks only by adult males. Autopsy of moose older than calves that were killed by brown bears revealed that yearlings were more prone to predation than older moose, and that older (i.e. >= 2 years) cows were more vulnerable to predation than older bulls. Our study suggests a lower tendency for Scandinavian brown bears to prey on moose compared to most of the North American studies.
|
|
| 13. |
- Gatali, Callixte, et al.
(författare)
-
Bird diversity in the savanna habitats of Akagera National Park, Rwanda, in the post-war recovery period
- 2015
-
Ingår i: Ostrich. - : National Inquiry Services Center (NISC). - 0030-6525 .- 1727-947X. ; 86:3, s. 267-276
-
Tidskriftsartikel (refereegranskat)abstract
- The biodiversity of Akagera National Park (ANP), Rwanda, has reportedly been declining since 1990 due to conflict and war in the country between 1990 and 1994. In this paper, we describe bird diversity in the post-war recovery period. We used systematic plots, point counts and presence-absence surveys to estimate bird species richness and diversity in acacia savanna habitats of the park between 2009 and 2011. We recorded a total number of 301 species, of which 75% were resident and 22% migrant, including a large number of Palearctic visitors and Afrotropical migrants. Particularly notable were four endemic species of the Lake Victoria region, four globally threatened and nine near-threatened species as well as species that had not previously been recorded in the park and those overlooked by past records. Estimated species richness and diversity at the landscape level were 346 and 0.98, respectively, mean estimates per plot were 42 and 0.86 for species richness and diversity, respectively. Our results highlight regional and international importance of ANP in protecting important bird diversity. We also emphasise that ANP is the only savanna habitat in Rwanda where typical savanna birds occur. Our findings provide new insights for further strengthening of efforts to conserve the park's biodiversity.
|
|
| 14. |
- Gunnarsson, Bengt, 1954, et al.
(författare)
-
Variable female mating positions and offspring sex ratio in the spider Pityohyphantes phrygianus (Araneae : linyphiidae)
- 2004
-
Ingår i: Journal of Insect Behavior. - 0892-7553. ; 17:1, s. 129-144
-
Tidskriftsartikel (refereegranskat)abstract
- Chromosomal sex determination and male heterogamety have been thought to seriously impede direct sex ratio control. However, in Pityohyphantes phrygianus, a solitary sheetweb spider with a skewed sex ratio, earlier experimental studies suggested that there are options for female control of offspring sex ratio, if females change their position during the normal mating sequence. Here we show that under natural conditions there is considerable between-female variation in positions, especially after termination of mating. Computer simulations of the orientation of female inner genitalia suggest that sperm are placed in different storage sites depending on the positions adopted. This means that a specific position after mating might potentially influence offspring sex ratio. The variance in offspring sex ratio among females in earlier experiments was binomially distributed, which leads us to conclude that females control the mean sex ratio but do not exercise direct control of the sex of individual offspring.
|
|
| 15. |
- Hösthagen, Anders, et al.
(författare)
-
Thermal crack risk estimations for tunnel : equivalent restraint method correlated to empirical observations
- 2014
-
Ingår i: Nordic Concrete Research. - 0800-6377. ; 49, s. 127-143
-
Tidskriftsartikel (refereegranskat)abstract
- The present study deals with the correlation between numerical models and empirical observations in newly cast concrete structures. The model used is the equivalent restraint method, ERM, which is established from several local restraint method calculations, LRM. The casting of walls and roof in a tunnel construction is investigated. Correlation between models and empirical measurements is established in three steps: 1) the restraint situation is analyzed; 2) the calculated temperature developments are compared to empirical temperature measurements to calibrate the models; and 3) calculated strain ratios are compared with observed crack patterns, and in general a good correlation is achieved
|
|
| 16. |
- Jonasson, Jan-Erik, et al.
(författare)
-
Gjutning av vägg på platta : studier av sprickrisker orsakat av temperaturförloppet vid härdningen
- 2009
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Tests casting the construction "wall on slab" have in the project been realized for three different situations. Measurements have been performed with respect to temperatures, deformations, strains and mapping of crack patterns. In addition, properties for the young concrete have been investigated to get basic data in order to estimate temperatures and risks of cracking. The construction wall on slab represents a typical case, which can be found in many real structures like walls, retaining walls, tray structures, tunnels and bridges.The project has two main questions: 1) What are the differences in restraint conditions between the three tested constructions? Is it correct to model a wall, that both has a horizontal casting joints against the slab, and a vertical casting joint against an adjacent wall, with a free wall of double length?, and 2) Does a slip in the horizontal casting joint exist, and does is reduce the restraint in the wall?The answers are that the supposed models describe the real behaviour very well. This was confirmed by the fact that both the temperatures as well as the crack risks agreed very well between the test results and the calculation results. For the walls that cracked a slip in the casting joints could be indicated, but these test results could not be quantified. In summary, the project has been successful and clearly answered questions that previously only were based on assumptions.
|
|
| 17. |
|
|
| 18. |
- Jonasson, Jan-Erik, et al.
(författare)
-
How to build crack-free durable concrete structures : concrete hardening technology including modelling of shrinkage, creep and temperature of young concrete and its influence on durability and lifetime
- 2009
-
Ingår i: ISLECI 2009. - : Central South University of Forestry and Technology, China.
-
Konferensbidrag (refereegranskat)abstract
- Control of thermal and shrinkage cracking in hardening concrete is of great importance to ensure desired service life and function of concrete infrastructures. Making reliable stress estimations, and thereby conclusions about cracking risks caused by temperature movements and shrinkage involves advanced modelling of material properties and structural restraint. The paper presents the main outline of a model for description of material properties needed. Special focus is given to a creep model denoted LLM (Linear Logarithmic Model), which is shown to be robust, easy to use, and capable to extrapolate short-term test into long-term effects. Applications of the presented model using the computer program ConTeSt Pro demonstrates that it can be used to decide what measures to be taken to minimize the risk of cracking during the hardening phase for concrete structures.
|
|
| 19. |
- Jonasson, Jan-Erik, et al.
(författare)
-
Temperatursprickor i betongkonstruktioner : handbok med diagram för sprickriskbedömning inklusive åtgärder för några vanliga typfall. Del D och E
- 2001
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Föreliggande handbok är framtagen i ett SBUF-projekt med Kjell Wallin, Peab som projektledare. Projektet har genomförts i nära samarbete mellan Peab Sverige AB och Luleå tekniska universitet. Arbetet har inneburit att ett stort antal datorberäkningar har genomförts, och de redovisas i diagramform i denna handbok. Resultaten avses att användas att fylla i en blankett i ett Excel-ark. Syftet är att för typfallet vägg-på-platta ska handboken ge underlag för sprickriskbedömning och i förekommande fall ange vilka typåtgärder som ska sättas in. Avsikten är därvid att man inte ska behöva göra några externa beräkningar, men användaren har full frihet att själv ta fram temperaturen eller tvångssituationen på godtyckligt annat sätt. Handboksmetodiken avser en fortsättning på det som i Bronormen (Bro 94, bilaga 9-5) kallas metod 2, och den redovisade kompletteringen innefattar främst att erforderliga åtgärder (kylning och/eller värmning) för det valda typfallet inkluderas.
|
|
| 20. |
- Moberg, Christina, et al.
(författare)
-
De unga gör helt rätt när de stämmer staten
- 2022
-
Ingår i: Aftonbladet. - 1103-9000.
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
|
|
| 21. |
- Moksnes, Kjell Martin, et al.
(författare)
-
Behavioural neurology of sporadic vascular dementia
- 2004
-
Ingår i: Cerebrovascular disease, cognitive impairment and dementia, 2nd edition of Cerebrovascular disease and dementia. O'Brien J, Ames D, Gustafson L, Folstein MF, Chiu E (eds). - London : Martin Dunitz Ltd. - 0203495802 ; , s. 207-19
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
|
| 22. |
- Neumann, Wiebke, et al.
(författare)
-
Divergence in parturition timing and vegetation onset in a large herbivore-differences along a latitudinal gradient
- 2020
-
Ingår i: Biology Letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 16:6
-
Tidskriftsartikel (refereegranskat)abstract
- In northern environments, the period of access to high-quality forage is limited, exerting strong selective pressure to optimize the timing of parturition. We analysed timing and variation in moose (Alces alces) parturition dates of 555 females at 18 study sites across 12 degrees of latitude (56-68 degrees N, 1350 km) in Sweden. We found evidence for a spatial match of parturition timing to vegetation onset, but no evidence that moose adjust parturition to vegetation onset in a given year. We found a breakpoint at 64 degrees N. Despite adaptation across latitudes, temporal divergences occurred. Females below 64 degrees N calved after vegetation onset and females above 64 degrees N calved before. Here, parturition before vegetation onset might be a strategy to optimize forage utilization time with the very short growing season. Highly seasonal environments such as at higher latitudes may make it advantageous to adapt parturition towards long-term climatic patterns by matching the most favourable period. Given the direction of temporal divergence, our study suggests that climate change may have less of an impact on moose parturition at northern latitudes than southern latitudes.
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
- Nordén, Björn, 1965, et al.
(författare)
-
Indicators of biodiversity, what do they indicate? Lessons for conservation of cryptogams in oak-rich forest
- 2007
-
Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207. ; 135:3, s. 369-379
-
Tidskriftsartikel (refereegranskat)abstract
- In the Nordic countries, sets of Indicator (Signal) species, predominantly cryptogams, have been used as one measure to find forest stands which may harbour Red List species. Such data could potentially also be used to prioritise among stands for protection as nature reserves. We studied if the number of Signal species indicates the number of Red List species in oak-rich mixed forest in south Sweden. We also explored if species richness of the investigated groups is correlated with the number of Red List or Signal species. In 25 stands, we surveyed epiphytic and epixylic bryophytes and lichens, ground-floor bryophytes, and wood-living fungi. We studied correlations for two datasets; (1) all forest species and (2) deciduous forest specialists. When relating the number of Signal species to the number of Red List species for each taxon and in total, a significant correlation was found for temperate deciduous forest lichens. The number of Signal species was further significantly correlated to total species richness for lichens (all forest species) and for wood-living fungi (both datasets). The number of Red List lichens was correlated to total lichen richness (deciduous forest species). Signal species seem not to be unequivocal in prioritising potential reserves among valuable oak-rich woodlands and surveys by Red List species experts may be needed. Signal species may be more useful for finding relatively valuable sites in a matrix of production forest. Moreover, Signal species seem to be useful surrogates for total cryptogam species richness.
|
|
| 26. |
- Nyberg, Jenny, 1976, et al.
(författare)
-
Cardiovascular and cognitive fitness at age 18 and risk of early-onset dementia.
- 2014
-
Ingår i: Brain : a journal of neurology. - : Oxford University Press (OUP). - 1460-2156. ; 137:Pt 5, s. 1514-23
-
Tidskriftsartikel (refereegranskat)abstract
- Patients with early-onset dementia are a significantly under-recognized subgroup of patients with an increasing prevalence. Epidemiological studies are limited and studies of modifiable risk factors, such as physical fitness, are lacking. We aimed to investigate the associations between cardiovascular fitness individually and in combination with cognitive performance at age 18 and risk of early-onset dementia and mild cognitive impairment later in life. We performed a population-based cohort study of over 1.1 million Swedish, 18-year-old, male conscripts, who underwent conscription exams between 1968 and 2005. These males were then followed for up to 42 years. Objective data on cardiovascular fitness and cognitive performance were collected during conscription exams and were subsequently linked with hospital registries to calculate later risk of early-onset dementia and mild cognitive impairment using Cox proportional hazards models controlling for several confounders. The scores from the exams were divided into tertiles (low, medium, high) for the analyses. The mean follow-up time for the analyses was 25.7 years (standard deviation: 9.3) and the median was 27 years. In total, 30 195 315 person-years of follow-up were included in the study. In fully adjusted models, both low cardiovascular fitness and cognitive performance (compared to high) at age 18 were associated with increased risk for future early-onset dementia (cardiovascular fitness, n = 662 events: hazard ratio 2.49, 95%, confidence interval 1.87-3.32; cognitive performance, n = 657 events: hazard ratio 4.11, 95%, confidence interval 3.19-5.29) and mild cognitive impairment (cardiovascular fitness, n = 213 events: hazard ratio 3.57, 95%, confidence interval 2.23-5.74; cognitive performance, n = 212 events: hazard ratio 3.23, 95%, confidence interval 2.12-4.95). Poor performance on both cardiovascular fitness and cognitive tests was associated with a >7-fold (hazard ratio 7.34, 95%, confidence interval 5.08-10.58) and a >8-fold (hazard ratio 8.44, 95%, confidence interval 4.64-15.37) increased risk of early-onset dementia and early-onset mild cognitive impairment, respectively. In conclusion, lower cardiovascular fitness and cognitive performance in early adulthood were associated with an increased risk of early-onset dementia and mild cognitive impairment later in life, and the greatest risks were observed for individuals with a combination of low cardiovascular fitness and low cognitive performance.
|
|
| 27. |
- Pantoni, Leonardo, et al.
(författare)
-
Impact of age-related cerebral white matter changes on the transition to disability -- the LADIS study : rationale, design and methodology.
- 2005
-
Ingår i: Neuroepidemiology. - : S. Karger AG. - 0251-5350 .- 1423-0208. ; 24:1-2, s. 51-62
-
Tidskriftsartikel (refereegranskat)abstract
- Age-related white matter changes (ARWMC) on brain MRI have been associated with cognitive, motor, mood and urinary disturbances. These factors are known to contribute to disability in elderly people, but the impact of ARWMC and of their progression on the transition to disability is not determined. The LADIS (Leukoaraiosis and Disability in the Elderly) study aims at assessing the role of ARWMC as an independent predictor of the transition to disability in initially nondisabled elderly (65–84 years). Subjects who are not impaired or impaired on only 1 item of the Instrumental Activity of Daily Living (IADL) scale, presenting with different grades of ARWMC severity, were enrolled. Eleven European centers are involved. All the patients were assessed at baseline using an extensive set of clinical and functional tests including global functioning, cognitive, motor, psychiatric and quality of life measures. MRI studies were performed at baseline and will be repeated at the end of the follow-up period to evaluate changes of ARWMC and other lesions. ARWMC were categorized into mild, moderate or severe using the scale of Fazekas et al. For each ARWMC severity class, the primary study outcome is the transition to disability defined as an impairment on 2 or more IADL scale items. Secondary outcomes are the occurrence of dementia, depression, vascular events or death. Six-hundred and thirty-nine subjects (mean age 74.13 ± 5.0 years, M/F: 288/351) were enrolled in a hospital-based setting and are being followed up for up to 3 years. The large and comprehensive set of measures in LADIS enables a comprehensive description of their functional and clinical features to be examined in relation to different morphological patterns and severity of ARWMC. The longitudinal design will give insight into the possible role of ARWMC and their progression as an independent contributor to disability in the elderly, eventually helping to develop preventive strategies to reduce the burden of disability in late life. The study results may also help to standardize, on an international basis, tools and criteria to identify early stages of disability.
|
|
| 28. |
|
|
| 29. |
|
|
| 30. |
- Söderberg, Johan, 1980-, et al.
(författare)
-
Haemolysis index : an estimate of preanalytical quality in primary health care!
- 2009
-
Ingår i: Clinical Chemistry and Laboratory Medicine. - 1434-6621 .- 1437-4331. ; 47:8, s. 940-944
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Haemolysis is usually caused by inadequate specimen collection or preanalytical handling, and is suggested to be a suitable indicator of preanalytical quality. We investigated the prevalence of detectable haemolysis in all routine venous blood samples to identify differences in preanalytical quality.Methods: Haemolysis index (HI) values were obtained from a Vitros 5,1 in the routine clinical chemistry laboratory for samples collected in primary health care centres (PHCs), nursing homes, and a hospital emergency department (ED). Haemolysis was defined as a HI ≥ 15 (detection limit).Results: Samples from the PHC with the highest prevalence of haemolysis were 6.1 times (95% confidence interval (CI) 4.0-9.2) more often haemolysed compared to the centre with the lowest prevalence. Of the samples collected in primary health care, 10.4% were haemolysed compared to 31.1% in the ED (p< 0.001). A notable difference in haemolysed samples was found between the ED section staffed by emergency medicine physicians and the section staffed by primary health care physicians (34.8% vs. 11.3%, p<0.001).Conclusions: The significant variation in haemolysis indices among the investigated units is likely to reflect varying preanalytical conditions. The HI is a valuable tool for estimation and follow-up of preanalytical quality in primary health care.
|
|
| 31. |
- Söderberg, Johan, 1980-, et al.
(författare)
-
Incident reporting practices in the preanalytical phase : low reported frequencies in the primary health care setting
- 2009
-
Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Taylor & Francis. - 0036-5513 .- 1502-7686. ; 69:7, s. 731-735
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Incident reporting is commonly used to improve patient safety. The preanalytical phase of laboratory testing contains several manual error-prone tasks where mistakes can affect patient outcomes. However, the practical use of incident reports in this area has not been previously investigated in the primary health care setting, where the majority of the patients come in contact with health care.MATERIAL AND METHODS: All staff responsible for venous blood sampling in 70 primary health care centres and in two hospital clinical laboratories (317 respondents, response rate 94%) completed a questionnaire.RESULTS: Of the primary health care staff, 69% reported that they had never filed an incident report regarding venous blood sampling. Barriers for not filing incident reports often/always included lack of time (44%) and a complicated reporting procedure (27%). A higher proportion of staff with re-education (43%) had filed at least one incident report as compared to those without re-education (20%, p < 0.001). No differences in incident reporting practices were found between primary health care and hospital clinical laboratory staff.CONCLUSIONS: The investigated incident reporting system is likely to underreport incidents in the preanalytical phase. Therefore, the ability to discover preventable system vulnerabilities needs refinement.
|
|
| 32. |
- Söderberg, Johan, et al.
(författare)
-
Is the test result correct? A questionnaire study of blood collection practices in primary health care
- 2010
-
Ingår i: Journal of Evaluation In Clinical Practice. - : Blackwell Publishing. - 1356-1294 .- 1365-2753. ; 16:4, s. 707-711
-
Tidskriftsartikel (refereegranskat)abstract
- Rationale, aims and objectives Venous blood tests are important for clinical decision making. Most errors in blood testing are due to human errors before the blood samples reach the laboratory. The present study was designed to investigate venous blood sampling (VBS) practices in primary health care centres (PHCs) compared with clinical laboratory staff.Method A cross-sectional survey of 70 PHCs and two clinical laboratories is conducted. All staff responsible for VBS (317 respondents, response rate 94%) completed a questionnaire on VBS practices.Results Instructions for VBS were not followed in the surveyed PHCs. For example, only 54% reported that they always identified the patient by using name/Swedish identification number and only 5% reported that they always used photo-ID, the two preferred means for patient identification. Only 12% reported that they always released venous stasis as soon as possible. Fewer PHC staff than clinical laboratory staff reported correct VBS practices. For example, 54% of the PHC staff reported that they always identified the patient by name and Swedish identification number, as compared with 95% of the clinical laboratory staff (P < 0.001). Documented VBS routines and re-education in VBS were not clearly associated with reported correct VBS practices.Conclusions In the surveyed PHCs, there are clinically important risks for misidentification of patients and erroneous test results, with consequences for the diagnosis and treatment of patients. Quality interventions, aimed at improving VBS practices, are needed to ensure patient safety.
|
|
| 33. |
- Söderberg, Johan, 1980-, et al.
(författare)
-
Preanalytical errors in primary healthcare : a questionnaire study of information search procedures, test request management and test tube labelling
- 2009
-
Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter. - 1434-6621 .- 1437-4331. ; 47:2, s. 195-201
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Most errors in laboratory medicine occur in the preanalytical phase and are the result of human mistakes. This study investigated information search procedures, test request management and test tube labelling in primary healthcare compared to the same procedures amongst clinical laboratory staff.Methods: A questionnaire was completed by 317 venous blood sampling staff in 70 primary healthcare centres and in two clinical laboratories (response rate = 94%).Results: Correct procedures were not always followed. Only 60% of the primary healthcare staff reported that they always sought information in the updated, online laboratory manual. Only 12% reported that they always labelled the test tubes prior to drawing blood samples. No major differences between primary healthcare centres and clinical laboratories were found, except for test tube labelling, whereby the laboratory staff reported better practices. Re-education and access to documented routines were not clearly associated with better practices.Conclusions: The preanalytical procedure in the surveyed primary healthcare centres was associated with a risk of errors which could affect patient safety. To improve patient safety in laboratory testing, all healthcare providers should survey their preanalytical procedures and improve the total testing process with a systems perspective.
|
|
| 34. |
|
|
| 35. |
|
|
| 36. |
- Wallin, Kjell, et al.
(författare)
-
Förekomst av döda fåglar vid Bohuskusten - 2001-2003 Västra Götalands län
- 2004
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- − Fågelfaunan i Bohusskärgården har sedan 2001 övervakats med ett heltäckande rutsystem. − Det övergripande syftet med övervakningen är att ha kunskap kustfågelfaunans tillstånd i naturreservat, fågelskyddsområden och för kusten som helhet. − Med en övervakning går det att upptäcka oväntade fenomen (t ex fågeldöd) och hantera de konsekvenser som sådana kan ha för skärgårdsmiljön. − Antalet fynd av döda fåglar under försommaren skattas årligen till mellan 1 000 - 2 500 fåglar. − Beräkningarna underskattar det verkliga antalet eftersom inte alla döda fåglar hittas under inventeringarna. − Ejder och måsfåglar utgör 85% av funna döda fåglar. − Den uppskattade dödsrisken varierar mellan 0.5 – 2.2% och är därmed lägre än den årliga dödsrisken som dessa arter normalt har. − Antalet fynd av döda fåglar har minskat under de tre åren som övervakningen pågått. − I rapporten föreslås en beslutsmodell som förvaltningsansvariga myndigheter skulle kunna använda då oväntade fenomen som omfattande fågeldöd uppträder. − Modellen visar att man i Bohusskärgården normalt kan förvänta sig omfattande fågeldöd på upp till fyra platser under ett år. Detta antal utgör en övre beslutsgräns. Inträffar fler händelser kan åtgärder, undersökningar eller noggrannare uppföljningar övervägas. − Antal platser med omfattande fågeldöd har i genomsnitt varit 1.67 per år, vilket är vad som naturligt kan förväntas i Bohusskärgården. 2
|
|
| 37. |
|
|
| 38. |
- Wallin, Kjell P., et al.
(författare)
-
Intensive family therapy : a program evaluation
- 2007
-
Ingår i: Journal of Family Psychotherapy. - Binghamton, NY : Haworth Press. - 0897-5353 .- 1540-4080. ; 18:2, s. 1-15
-
Tidskriftsartikel (refereegranskat)abstract
- The main objective was to study intensive family therapy (IFT) within a treatment program carried out at a child and adolescent psychiatric clinic. Our study uses a quasi-experimental design with pre-treatment, post-treatment, and follow-up assessment and comprises 46 consecutive families, using the Family Relations Scale, Symptom Check List-90, and Child Behavior Check List. Baseline values reveal a heavy problem load. Significant differences were, however, shown from pre-treatment to the six-month follow-up and pre-treatment to the two-year follow-up on all three scales. The effect sizes from pre-treatment to the six-month follow-up were low to medium. IFT works for multi-problem families, with continued improvements after completed treatment.
|
|
| 39. |
|
|
| 40. |
|
|
| 41. |
- Wallin, Olof, et al.
(författare)
-
Blood sample collection and patient identification demand improvement : a questionnaire study of preanalytical practices in hospital wards and laboratories
- 2010
-
Ingår i: Scandinavian Journal of Caring Sciences. - : Wiley. - 0283-9318 .- 1471-6712. ; 24:3, s. 581-591
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Most errors in venous blood testing result from human mistakes occurring before the sample reach the laboratory.Aims: To survey venous blood sampling (VBS) practices in hospital wards and to compare practices with hospital laboratories.Methods: Staff in two hospitals (all wards) and two hospital laboratories (314 respondents, response rate 94%), completed a questionnaire addressing issues relevant to the collection of venous blood samples for clinical chemistry testing.Results: The findings suggest that instructions for patient identification and the collection of venous blood samples were not always followed. For example, 79% of the respondents reported the undesirable practice (UDP) of not always using wristbands for patient identification. Similarly, 87% of the respondents noted the UDP of removing venous stasis after the sampling is finished. Compared with the ward staff, a significantly higher proportion of the laboratory staff reported desirable practices regarding the collection of venous blood samples. Neither education nor the existence of established sampling routines was clearly associated with VBS practices among the ward staff.Conclusions: The results of this study, the first of its kind, suggest that a clinically important risk of error is associated with VBS in the surveyed wards. Most important is the risk of misidentification of patients. Quality improvement of blood sample collection is clearly needed, particularly in hospital wards.
|
|
| 42. |
- Wallin, Olof, et al.
(författare)
-
Patient-centred care - preanalytical factors demand attention : a questionnaire study of venous blood sampling and specimen handling
- 2007
-
Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 67:8, s. 836-847
-
Tidskriftsartikel (refereegranskat)abstract
- Objective. Most mistakes in laboratory medicine are the result of human error occurring before the blood sample reaches the laboratory. This survey of preanalytical procedures was designed to identify sources of error and potential targets for quality improvement strategies. Material and methods. The staff in a highly specialized surgical ward at a university hospital completed a questionnaire addressing the collection and handling of venous blood samples in plastic vacuum test‐tubes for general clinical chemistry testing. Results. The results suggest that venous blood sampling instructions are not always followed. When uncertain about how a sample should be collected, the majority of respondents rely on potentially poor sources of information, such as out‐of‐date printed instructions or the advice of a colleague, rather than consult up‐to‐date electronic instructions. Furthermore, they do not always report errors and the referrals are not always handled according to sampling instructions. The respondents were highly motivated, however, and had a strong interest in receiving further education in, and assuming increased responsibility for, venous blood sampling procedures in the ward. Conclusions. We believe that the introduction of standardized routines and regular staff training, combined with an exchange of the existing paper‐based referral management system with an electronic system for managing referrals, could increase safety in the preanalytical process, with positive effects on patient safety. Given the importance of venous blood samples in patient care, a more extensive study covering other hospital wards and primary health‐care centres is needed. Read More: http://informahealthcare.com/doi/abs/10.1080/00365510701370675
|
|
| 43. |
- Wallin, Olof, et al.
(författare)
-
Preanalytical effects of pneumatic tube transport on routine haematology, coagulation parameters, platelet function and global coagulation
- 2009
-
Ingår i: Clinical Chemistry and Laboratory Medicine. - 1434-6621 .- 1437-4331. ; 46:10, s. 1443-1449
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Pneumatic tube transport of blood samples reduces turnaround times and labour. However, the preanalytical effects on new clinical chemistry parameters and instruments are not fully known. The aim of this study was to evaluate the effect of pneumatic tube transport on haematology and coagulation parameters, including platelet function with PFA-100®, and global coagulation with a thromboelastograph.Methods: Paired venous blood samples from healthy volunteers were obtained before and after 1 week of treatment with acetylsalicylic acid. One sample was transported by pneumatic tube transport, while the other remained in the laboratory.Results: No preanalytical effect of pneumatic tube transport could be seen for most haematology and coagulation parameters, as well as analysis with PFA-100®. For the thromboelastographic analysis, time to clot formation was shorter (–16%, p=0.037) in the transported samples. Treatment with acetylsalicylic acid had no effect on the majority of the test results.Conclusions: Pneumatic tube transport does not introduce preanalytical errors when transporting samples for analysis of routine haematology, coagulation parameters and platelet function with the PFA-100®. We recommend manual transport of samples for analysis with thromboelastographic techniques.
|
|
| 44. |
- Wallin, Olof, 1976-
(författare)
-
Preanalytical errors in hospitals : implications for quality improvement of blood sample collection
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Most errors in the venous blood testing process are preanalytical, i.e. they occur before the sample reaches the laboratory. Unlike the laboratory analysis, the preanalytical phase involves several error-prone manual tasks not easily avoided with technological solutions. Despite the importance of the preanalytical phase for a correct test result, little is known about how blood samples are collected in hospitals. Aim: The aim of this thesis was to survey preanalytical procedures in hospitals to identify sources of error. Methods: The first part of this thesis was a questionnaire survey. After a pilot study (Paper I), a questionnaire addressing clinical chemistry testing was completed by venous blood sampling staff (n=314, response rate 94%) in hospital wards and hospital laboratories (Papers II–IV). The second part of this thesis was an experimental study. Haematology, coagulation, platelet function and global coagulation parameters were compared between pneumatic tube-transported samples and samples that had not been transported (Paper V). Results: The results of the questionnaire survey indicate that the desirable procedure for the collection and handling of venous blood samples were not always followed in the wards (Papers II–III). For example, as few as 2.4% of the ward staff reported to always label the test tube immediately before sample collection. Only 22% of the ward staff reported to always use wristbands for patient identification, while 18% reported to always use online laboratory manuals, the only source of updated information. However, a substantial part of the ward staff showed considerable interest in re-education (45%) and willingness to improve routines (44%) for venous blood sampling. Compared to the ward staff, the laboratory staff reported significantly higher proportions of desirable practices regarding test request management, test tube labelling, test information search procedures, and the collection and handling of venous blood samples, but not regarding patient identification. Of the ward staff, only 5.5% had ever filed an error report regarding venous blood sampling, compared to 28% of the laboratory staff (Paper IV). In the experimental study (Paper V), no significant preanalytical effect of pneumatic tube transport was found for most haematology, coagulation and platelet function parameters. However, time-to-clot formation was significantly shorter (16%) in the pneumatic tube-transported samples, indicating an in vitro activation of global coagulation. Conclusions. The questionnaire study of the rated experiences of venous blood sampling ward staff is the first of its kind to survey manual tasks in the preanalytical phase. The results suggest a clinically important risk of preanalytical errors in the surveyed wards. Computerised test request management will eliminate some, but not all, of the identified risks. The better performance reported by the laboratory staff may reflect successful quality improvement initiatives in the laboratories. The current error reporting system needs to be functionally implemented. The experimental study indicates that pneumatic tube transport does not introduce preanalytical errors for regular tests, but manual transport is recommended for analysis with thromboelastographic technique. This thesis underscores the importance of quality improvement in the preanalytical phase of venous blood testing in hospitals.
|
|
| 45. |
- Wallin, Olof, et al.
(författare)
-
Preanalytical venous blood sampling practices demand improvement : A survey of test-request management, test-tube labelling and information search procedures.
- 2008
-
Ingår i: Clinica Chimica Acta. - : Elsevier BV. - 0009-8981 .- 1873-3492. ; 391:1-2, s. 91-97
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- BACKGROUND: Most errors in laboratory medicine are preanalytical in nature. In the present study, we aimed to survey preanalytical steps in venous blood sampling, prior to actual sample collection. These steps included test-request management and test-tube labelling, as well as information search procedures. METHODS: Venous blood sampling staff (n=314, response rate 94%) in hospital wards and laboratories completed a questionnaire related to clinical chemistry testing. RESULTS: Instructions for test-request management and test-tube labelling were not always followed. For example, only 66% of the ward staff reported always checking the test-request if someone else completed it, compared to 90% of the laboratory staff (p=0.003). As few as 16% of the ward staff reported desirable practices regarding test-tube labelling, compared to 100% of the laboratory staff (p<0.001). Furthermore, 18% of the ward staff reported always using online manuals (the only source of updated information), compared to 63% of the laboratory staff (p<0.001). CONCLUSIONS: Our results indicate a substantial risk of preanalytical error in test-request management, test-tube labelling, and information search practices, particularly in the wards. Our findings thus underscore the importance of quality control in venous blood sampling, in order to increase patient safety in modern health care.
|
|
| 46. |
|
|
