988 research outputs found
Regional Growth and Access to Knowledge and Dense Markets -An Empirical Study of the Performance in Sweden.
Access to knowledge and local service markets can be assumed to explain regional growth performance. The supply of services and knowledge with respect to regional development are stressed in the seminal papers by for example Rivera-Batiz (1988) and Knowledge referens. In this paper we make an empirical analyse using panel data for Swedish regions. The purpose is to analyse the relationship between regional growth and access to knowledge. We also acknowledge the size of the regional economy and access to the local labour market. We estimate first a cross-section model by using OLS. Second we employ a panel data model, using time distance access to population and the share local labour force with high education as explanatory variables. In the analysis we compare the results from the different models and our own results from the Swedish economy with other studies in this field. We find that local externalities for increasing returns are very important in the Swedish economy. Our estimated models yields a high level of goodness of fit, and the results indicates significant elasticity for high education and population density in the Swedish economy with respect to performance of regional gross domestic product.
Changes in expression of PACAP in rat sensory neurons in response to sciatic nerve compression.
In the present study, expression of pituitary adenylate cyclase-activating polypeptide (PACAP) in rat dorsal root ganglion (DRG) neurons and sciatic nerve following experimental sciatic nerve compression was studied with the use of quantitative immunohistochemistry and in situ hybridization. Previously, we have investigated changes in PACAP expression after nerve transection and, here, the far more frequently encountered condition of nerve compression injury is examined. Nerve compression was performed unilaterally on the rat sciatic nerve, at mid-thigh level, by application of a narrow silicone tube around the nerve for 3, 7, 14 or 28 days, respectively. We detect a statistically significant upregulation in the number and density of PACAP mRNA expression in both small and large DRG neurons in response to nerve compression. An increased number of PACAP-immunoreactive neurons is also found in the ipsilateral DRG. In addition, PACAP immunoreactivity is observed in the compressed sciatic nerve segment and adjacent nerve tissue after nerve compression. The present findings can be compared with previous studies where we have shown that PACAP expression is upregulated in DRG; in response to peripheral inflammation (primarily in small-medium neurons), and after axotomy (dramatic upregulation in medium-large neurons). In view of the recent findings of an increased PACAP expression in DRG after nerve compression, as well as the previous findings of a modulation of PACAP expression in response to axotomy and inflammation, it is likely that PACAP is also involved in the modulation of the response to peripheral nerve compression
Swedish Butterfly Monitoring Scheme, annual report for 2011
This is the second annual report for the Swedish Butterfly Monitoring Scheme, a national monitoring programme coordinated by Lund University for the Swedish Environmental Protection Agency since 2010. The programme is a partnership between the Entomological Society of Sweden, the Swedish Environmental Protection Agency, Lund University, the Swedish University of Agricultural Sciences and the Swedish County Administration Boards. The monitoring scheme is volunteer-based and runs from April 15th to September 15th annually. Sites are visited 3-7 times per season and are surveyed using a standardized, common methodology. Two different recording methods are used in the Swedish Butterfly Monitoring Scheme. One is the point site counts which cover an area with a 25 m radius for 15 min per visit. The other method is fixed-route Pollard walk transects, typically 1-3 km in length. These two methods enable the monitoring scheme to assess yearly changes both in the number of butterflies seen and in species composition. The second year’s monitoring has produced butterfly data from 98 fixed-route walks and 173 point sites, representing a 66% increase in the number of transects and a 60% increase in the number of point sites. The sites and walks are located across the whole country, from Falsterbo in the South to Luleå in the North. In 2011, 203 volunteer recorders participated in the Swedish Butterfly Monitoring Scheme and have counted 54 700 butterflies of 92 different species. The number of volunteers has increased with 72% and the coverage of the Swedish fauna has increased by 11%. One biannual species seen in 2010, the Baltic Grayling, was not recorded in 2011. On average, 14.5 species have been observed at the point sites while 21.1 have been observed along transects. In this report, observations from 2011 of each species are shown as total counts, distribution maps, and flight period histograms. The most numerous species in 2011 was the Ringlet, followed by the Meadow Brown and the Small Tortoiseshell. Trends between 2010 and 2011 have been analysed in terms of deviations from expected numbers of individuals. Additionally, because of the high number of sites monitored already in 2010-2011, it has been possible to analyse population trends for 12 grassland butterflies using the analytical tool TRIM, thereby contributing to the 2012 European Butterfly Indicator for Grassland species
Steel-soil composite bridge:an alternative design solution for short-span bridges towards sustainability
The construction sector is a major source of greenhouse gases. Under the increasing concern about climate change and growing construction activities, the whole sector is challenged to shift focus toward sustainable solutions. The traditional procurement often prioritizes technical and economic viability, while their environmental performance is overlooked. Today’s designers are urged to seek new design options to reduce environmental burdens. Sweden owns more than 24574 bridges, most of which are short spans. Among them, the slab frame bridge (CFB) is a common solution. Soil steel composite bridge (SSCB), alternatively, is a functional equivalent solution to CFB and shows advantages in low cost and easy construction. This paper compares the environmental performance between these two bridge types based on life cycle assessment (LCA). The analysis and its results show that the SSCB is preferable over CFB in most of the examined environmental indicators
Predator faunas past and present: quantifying the influence of waterborne cues in divergent ecotypes of the isopod Asellus aquaticus
Waterborne chemical cues are an important source of information for many aquatic organisms, in particular when assessing the current risk of predation. The ability to use chemical cues to detect and respond to potential predators before an actual encounter can improve prey chances of survival. We investigated predator recognition and the impact of chemical cues on predator avoidance in the freshwater isopod Asellus aquaticus. This isopod has recently colonised a novel habitat and diverged into two distinct ecotypes, which encounter different predator communities. Using laboratory-based choice experiments, we have quantified behavioural responses to chemical cues from predators typical of the two predator communities (larval dragonflies in the ancestral habitat, perch in the newly colonised habitat) in wild-caught and lab-reared Asellus of the two ecotypes. Individuals with prior experience of predators showed strong predator avoidance to cues from both predator types. Both ecotypes showed similar antipredator responses, but sexes differed in terms of threat-sensitive responses with males avoiding areas containing predator cues to a larger extent than females. Overall, chemical cues from fish elicited stronger predator avoidance than cues from larval dragonflies. Our results indicate that in these isopods, prior exposure to predators is needed to develop antipredator behaviour based on waterborne cues. Furthermore, the results emphasise the need to analyse predator avoidance in relation to waterborne cues in a sex-specific context, because of potential differences between males and females in terms of vulnerability and life history strategies
Swedish Butterfly Monitoring Scheme, annual report for 2010
This is the first annual report for the Swedish Butterfly Monitoring Scheme, a new national monitoring programme coordinated by Lund University for the Swedish Environmental Protection Agency. The programme was initiated in 2010, and is a partnership between the Entomological Society of Sweden, the Swedish Environmental Protection Agency, Lund University, the Swedish University of Agricultural Sciences and the Swedish County Administration Boards. The monitoring scheme is volunteer-based and runs from April 15th to September 15th annually. Sites are visited 3-7 times per season and are surveyed using a standardized, common methodology. Two different recording methods are used in the Swedish Butterfly Monitoring Scheme. One is the point site counts which cover an area with a 25 m radius for 15 min per visit. The other method is fixed-route Pollard walk transects, typically 1-3 km in length. These two methods enable the monitoring scheme to assess yearly changes both in the number of butterflies seen and in species composition. The first year’s monitoring has produced butterfly data from 59 fixed-route walks and 108 point sites, and the number of locations was almost six times more than expected. The sites and walks are located across the whole country, from Malmö in the South to Luleå in the North. In 2010, 117 volunteer recorders have joined the Swedish Butterfly Monitoring Scheme and have counted nearly 30 000 butterflies of 83 different species. On average, 12.3 species have been observed at the point sites while 20.3 have been observed along transects. In this report, observations from 2010 of each species are shown as total counts, distribution maps, and flight period histograms. The most numerous species in 2010 was the Ringlet. As yearly observation data accumulate, butterfly population trends will be analysed, both nationally within the Swedish Butterfly Monitoring Scheme and internationally within the network Butterfly Conservation Europe
The Boson peak in supercooled water
We perform extensive molecular dynamics simulations of the TIP4P/2005 model of water to investigate the origin of the Boson peak reported in experiments on supercooled water in nanoconfined pores and in hydration water around proteins. We find that the onset of the Boson peak in supercooled bulk water coincides with the crossover to a predominantly low-density-like liquid below the Widom line TW. The frequency and onset temperature of the Boson peak in our simulations of bulk water agree well with the results from experiments on nanoconfined water. Our results suggest that the Boson peak in water is not an exclusive effect of confinement. We further find that, similar to other glass-forming liquids, the vibrational modes corresponding to the Boson peak are spatially extended and are related to transverse phonons found in the parent crystal, here ice Ih.We thank S. V. Buldyrev and S. Sastry for helpful discussions. The simulations were in part performed using resources provided by the Swedish National Infrastructure for Computing (SNIC) at the NSC and HPC2N centers. LGMP, KTW and DS were supported by the Swedish Research Council. KTW is also supported by the Icelandic Research Fund through the START programme. PK acknowledges the support of National Academies Keck Future Initiatives award. HES thanks NSF Grants No. CHE0911389, No. CHE0908218, and No. CHE-1213217. (Swedish Research Council; Icelandic Research Fund through the START programme; National Academies Keck Future Initiatives award; CHE0911389 - NSF; CHE0908218 - NSF; CHE-1213217 - NSF)Published versio
Establishment of malting barley
Dålig uppkomst är ofta ett stort problem i Sverige och hur såbädden utformas påverkar utsädets
groning. Mälardalsregionen utmärks av höga lerhalter och därmed ställs särskilda krav på
brukningsmetod för att lyckas med odlingen. Dessutom tillämpas mycket plöjningsfri odling och det är
därför intressant att jämföra förhållandena i såbädden med plöjda system.
I detta examensarbete har en stickprovsundersökning av såbäddar gjorts, för att se hur förhållandena
påverkar etablering, tillväxt och skörd hos maltkorn. Såbäddsegenskaper i plöjningsfria jämfört med
plöjda system, samt effekter av extra harvning har också undersökts. Undersökningen ägde rum i
Mälardalen, där sex fält med reducerad bearbetning jämfördes med lika många plöjda fält för att ske
skillnad i tillväxt, etablering och skörd. Utöver det undersöktes åtta fält med reducerad bearbetning för
att se effekten av 2 extra harvningar på såbädden. Därtill jämfördes dagens såbäddar med Kritz
såbäddsundersökningar på 70-talet, för att se om förhållandena har blivit mer gynnsamma för groning
och plantutveckling.
Vid torra förhållanden anses såbädden behöva innehålla minst 50 % aggregat < 5 mm och vara 4 cm
djup. Det optimala sådjupet för korn sätts ofta till 4 cm, men beroendes på fuktigheten och såbäddens
struktur kan djupet behöva ökas. Fröet behöver dessutom ha minst 6 vikts-% växtillgängligt vatten för
att uppnå goda groningsbetingelser.
Såbäddarna i det plöjningsfria systemet hade ett mindre bearbetningsdjup, grövre struktur i ytan men
jämnare och finare såbotten. Mängden växtillgängligt vatten i såbotten var också högre, 10,7 vikts-%
jämfört med 7,3 vikts-% för det plöjda systemet. Fröplaceringen var relativt lika mellan systemen,
men en gård med det plöjningsfria systemet som använde skivbillmaskin lyckades mindre bra.
Uppkomstförloppet var snabbare i det reduderade systemet och därtill blev plantantalet 13 % högre än
i det plöjda systemet. Nederbörden under säsongen var relativt lika mellan systemen men störst
betydelse hade nederbörden en månad efter sådd i det plöjda systemet. Svampförekomsten av kornets
bladfläcksjuka var även högre vid reducerat system, vilket beror av smittade skörderester i ytan. Den
slutliga snittskörden i det plöjningsfria systemet var 558 kg/ha högre än för det plöjda systemet, men
skillnaden var inte statistiskt signifikant.
Dagens såbäddar var grövre än såbäddar på 70-talet enligt undersökningen av Kritz (1983), vilka både
hade mer finjord och mer växtillgängligt vatten i såbädden. I försöket med extra harvningar var
bearbetningsdjupet större och botten jämnare vid fler överfarter. Andelen finjord (aggregat < 5 mm) i
såbädden var också högre vid utökad bearbetning som troligtvis bidrog till fler plantor/m2 och större
skörd i slutändan. Ökningen var dock inte statistiskt signifikant men en merskörd på 268 kg/ha och ett
maltkornspris på 1,52 kr/kg gav ett ökat netto på ca 100 kr/ha
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