Planteringsförbandets betydelse för kvalitetsegenskaper i Contortatall (Pinus contorta var. latifolia)

In Sweden, large scale planting of Lodgepole pine (Pinus contorta var. latifolia) started in the beginning of the 1970’s. At first, the aim was production of pulpwood, but later, also production of timber became considered realistic. Today, Sweden has more than 520 000 ha of Lodgepole pine. Vast areas are now ready for thinning. However, the knowledge regarding forest management practices are still relatively limited. Among other studies, a master thesis shows that many properties of quality are dependant on the initial spacing. Two 20 years old Swedish spacing trials were then studied; Långsjönäset in Jämtland and Ängomsåsen in Medelpad. In this study, selected quality properties were again analysed on the same two spacing trials, now in an age of 41 years. The hypothesis was that butt logs with thinner branches, smaller relative branch diameter and smaller butt log taper are developed in more dense spacings. Another hypothesis was that initial spacing does not affect the frequency of basal- and bole sweeps and broken tops. Initial spacings of 1.60 m, 2.00 m, 2.85 m and 4.00 m were analysed. In total, 690 stems were included in the study. Butt log was identified as the first 4 m of the stem above height of the stump. Results from this study were also further compared with results from the above mentioned master thesis. For the three properties; thickest branch diameter, relative branch diameter and butt log taper, trees growing in an initial spacing of 2.85 m were of statistically significant lower quality than trees growing in a 2.00 m spacing. Between the initial spacings 1.60 m and 2.00 m no statistically significant differences could be found regarding these three quality properties. These results indicates that spacings denser than 2.00 m does not produce significally higher quality in the butt log. Only the initial spacing of 4.00 m was of statistically significant lower quality than the more dense spacings with respect to basal- and bole sweeps and broken tops. The present age of the stands is suitable for evaluation of quality properties. The results can be used as decision support concerning future management practices for stands and further industrial use of the wood.I Sverige påbörjades storskalig plantering av Contortatall (Pinus contorta var. latifolia) i början av 1970-talet. Massavedsproduktion var ursprungstanken men med tiden fann man contortan även lämplig för sågtimmerproduktion. I Sverige finns idag drygt 520 000 ha contorta och stora arealer börjar nu bli gallringsmogna. Produktionskunskapen är dock fortfarande begränsad; men ett tidigare masterarbete på då 20-åriga försökslokaler, Långsjönäset i Jämtland och Ängomsåsen i Medelpad, visar att många kvalitetsegenskaper påverkas av planteringsförbandet. I denna studie studerades återigen utvalda kvalitetsegenskaper på ovan nämnda lokaler, nu när träden uppnått 41 års totalålder. Hypoteserna var dels att rotstockar med klenare kvist, mindre relativ kvistdiameter och mindre avsmalning utvecklas i tätare förband, dels att gällande basal- och stamkrökar samt toppbrott har förbandet ingen påverkan på skadefrekvensen. Förbanden 1,60 m, 2,00 m, 2,85 m och 4,00 m studerades. Totalt mättes 690 stammar, rotstock utgjordes av stammens första 4 m ovan stubbhöjd. Resultat jämfördes också med resultat från ovan nämnt masterarbete. För de tre kvalitetsegenskaperna grövsta kvistdiameter, relativ kvistdiameter och stammens avsmalning var förband 2,85 m av statistiskt säkerställd sämre kvalitet än förband 2,00 m. Däremot fanns inga signifikanta skillnader mellan förbanden 1,60 m och 2,00 m gällande dessa tre kvalitetsegenskaper. Detta indikerar att förband tätare än 2,00 m troligen inte genererar signifikant bättre kvalitet i rotstocken. För krökar och toppbrott var endast förbandet 4,00 m av statistiskt säkerställd sämre kvalitet än övriga förband. Nuvarande beståndsålder är lämplig för utvärderingar av kvalitetsegenskaper. Resultaten används med fördel som beslutsstöd för fortsatt beståndsskötsel och industriell virkesanvändning

Zebrafish Ext2 is necessary for Fgf and Wnt signaling, but not for Hh signaling

<p>Abstract</p> <p>Background</p> <p>Heparan sulfate (HS) biosynthesis is tightly regulated during vertebrate embryo development. However, potential roles for HS biosynthesis in regulating the function of paracrine signaling molecules that bind to HS are incompletely understood.</p> <p>Results</p> <p>In this report we have studied Fgf, Wnt and Hedgehog (Hh) signaling in <it>ext2 </it>mutants, where heparan sulfate content is low. We found that Fgf targeted gene expression is reduced in <it>ext2 </it>mutants and that the remaining expression is readily inhibited by SU5402, an FGF receptor inhibitor. In the <it>ext2 </it>mutants, Fgf signaling is shown to be affected during nervous system development and reduction of Fgf ligands in the mutants affects tail development. Also, Wnt signaling is affected in the <it>ext2 </it>mutants, as shown by a stronger phenotype in <it>ext2 </it>mutants injected with morpholinos that partially block translation of Wnt11 or Wnt5b, compared to injected wild type embryos. In contrast, Hh dependent signaling is apparently unaffected in the <it>ext2 </it>mutants; Hh targeted gene expression is not reduced, the Hh inhibitor cyclopamine is not more affective in the mutants and Hh dependent cell differentiation in the retina and in the myotome are normal in <it>ext2 </it>mutants. In addition, no genetic interaction between <it>ext2 </it>and <it>shha </it>during development could be detected.</p> <p>Conclusion</p> <p>We conclude that <it>ext2 </it>is involved in Fgf and Wnt signaling but not in Hh signaling, revealing an unexpected specificity for <it>ext2 </it>in signaling pathways during embryonic development. Thus, our results support the hypothesis that regulation of heparan sulfate biosynthesis has distinct instructive functions for different signaling factors.</p

Многоканальный регистратор для унифицированных сигналов промышленного оборудования

Chondroitin/dermatan sulfate (CS/DS) proteoglycans consist of unbranched sulfated polysaccharide chains of repeating GalNAc-GlcA/IdoA disaccharide units, attached to serine residues on specific proteins. The CS/DS proteoglycans are abundant in the extracellular matrix where they have essential functions in tissue development and homeostasis. In this report a phylogenetic analysis of vertebrate genes coding for the enzymes that modify CS/DS is presented. We identify single orthologous genes in the zebrafish genome for the sulfotransferases chst7, chst11, chst13, chst14, chst15 and ust and the epimerase dse. In contrast, two copies were found for mammalian sulfotransferases CHST3 and CHST12 and the epimerase DSEL, named chst3a and chst3b, chst12a and chst12b, dsela and dselb, respectively. Expression of CS/DS modification enzymes is spatially and temporally regulated with a large variation between different genes. We found that CS/DS 4-O-sulfotransferases and 6-O-sulfotransferases as well as CS/DS epimerases show a strong and partly overlapping expression, whereas the expression is restricted for enzymes with ability to synthesize di-sulfated disaccharides. A structural analysis further showed that CS/DS sulfation increases during embryonic development mainly due to synthesis of 4-O-sulfated GalNAc while the proportion of 6-O-sulfated GalNAc increases in later developmental stages. Di-sulfated GalNAc synthesized by Chst15 and 2-O-sulfated GlcA/IdoA synthesized by Ust are rare, in accordance with the restricted expression of these enzymes. We also compared CS/DS composition with that of heparan sulfate (HS). Notably, CS/DS biosynthesis in early zebrafish development is more dynamic than HS biosynthesis. Furthermore, HS contains disaccharides with more than one sulfate group, which are virtually absent in CS/DS

Fish from Head to Tail:The 9th European Zebrafish Meeting in Oslo

International audienceThe 9th European Zebrafish Meeting took place recently in Oslo (June 28-July 2, 2015). A total of 650 participants came to hear the latest research news focused on the zebrafish, Danio rerio, and to its distant evolutionary relative medaka, Oryzias latipes. The packed program included keynote and plenary talks, short oral presentations and poster sessions, workshops, and strategic discussions. The meeting was a great success and revealed dramatically how important the zebrafish in particular has become as a model system for topics, such as developmental biology, functional genomics, biomedicine, toxicology, and drug development. A new emphasis was given to its potential as a model for aquaculture, a topic of great economic interest to the host country Norway and for the future global food supply in general. Zebrafish husbandry as well as its use in teaching were also covered in separate workshops. As has become a tradition in these meetings, there was a well-attended Wellcome Trust Sanger Institute and ZFIN workshop focused on Zebrafish Genome Resources on the first day. The full EZM 2015 program with abstracts can be read and downloaded from the EZM 2015 Web site zebrafish2015.org

Heparan Sulfate Biosynthesis – Clues from Knockout Mice

In the extracellular space, many specialized proteins are located to support cells and to mediate cell-cell signalling. One class of such molecules is heparan sulfate (HS) proteoglycans, which are proteins with different properties and locations but all of them decorated with long unbranched HS polysaccharide chains. During biosynthesis the HS chains are modified by sulfation and a C5-epimerase converts some glucuronic acid residues to iduronic acid. The patterns of the modifications vary distinctly between tissues and developing stages and give HS chains different affinity for biologically important proteins. Thus, the regulation of HS biosynthesis is likely to influence a wide variety of biological events. This thesis focuses on the biosynthesis of HS in animals with targeted disruptions in genes important for HS production. The N-deacetylase N-sulfotransferase (NDST) is a key enzyme in HS biosynthesis, directing other modifications. We show that NDST isoforms have very different roles in HS biosynthesis. Inactivation of NDST1 affects HS biosynthesis in all tissues. In embryonic liver HS from NDST1-/- mice the N-sulfation was decresed with twothirds, while the absence of NDST2 did not affect HS structure. In the absence of NDST1 in the liver, however, NDST2 is active in HS N-sulfation. In a study of embryonic stem cells lacking both NDST1 and NDST2, no N-sulfate groups could be detected. 6-O-sulfate groups were, however, still present at half of its normal level. This was an unexpected finding since 6-O-sulfotransferases have been thought to be strictly dependent on N-sulfate groups for substrate recognition. By adapting an automated method for HS analysis to mammalian tissues, we could extend our analyses to more tissues and other transgene models. We also developed a protocol to create a sensitive “fingerprint” of HS structure. With these methods we could determine the individual HS structure of different mouse tissues

Heparan Sulfate Biosynthesis – Clues from Knockout Mice

In the extracellular space, many specialized proteins are located to support cells and to mediate cell-cell signalling. One class of such molecules is heparan sulfate (HS) proteoglycans, which are proteins with different properties and locations but all of them decorated with long unbranched HS polysaccharide chains. During biosynthesis the HS chains are modified by sulfation and a C5-epimerase converts some glucuronic acid residues to iduronic acid. The patterns of the modifications vary distinctly between tissues and developing stages and give HS chains different affinity for biologically important proteins. Thus, the regulation of HS biosynthesis is likely to influence a wide variety of biological events. This thesis focuses on the biosynthesis of HS in animals with targeted disruptions in genes important for HS production. The N-deacetylase N-sulfotransferase (NDST) is a key enzyme in HS biosynthesis, directing other modifications. We show that NDST isoforms have very different roles in HS biosynthesis. Inactivation of NDST1 affects HS biosynthesis in all tissues. In embryonic liver HS from NDST1-/- mice the N-sulfation was decresed with twothirds, while the absence of NDST2 did not affect HS structure. In the absence of NDST1 in the liver, however, NDST2 is active in HS N-sulfation. In a study of embryonic stem cells lacking both NDST1 and NDST2, no N-sulfate groups could be detected. 6-O-sulfate groups were, however, still present at half of its normal level. This was an unexpected finding since 6-O-sulfotransferases have been thought to be strictly dependent on N-sulfate groups for substrate recognition. By adapting an automated method for HS analysis to mammalian tissues, we could extend our analyses to more tissues and other transgene models. We also developed a protocol to create a sensitive “fingerprint” of HS structure. With these methods we could determine the individual HS structure of different mouse tissues

Heparan Sulfate Biosynthesis – Clues from Knockout Mice

In the extracellular space, many specialized proteins are located to support cells and to mediate cell-cell signalling. One class of such molecules is heparan sulfate (HS) proteoglycans, which are proteins with different properties and locations but all of them decorated with long unbranched HS polysaccharide chains. During biosynthesis the HS chains are modified by sulfation and a C5-epimerase converts some glucuronic acid residues to iduronic acid. The patterns of the modifications vary distinctly between tissues and developing stages and give HS chains different affinity for biologically important proteins. Thus, the regulation of HS biosynthesis is likely to influence a wide variety of biological events. This thesis focuses on the biosynthesis of HS in animals with targeted disruptions in genes important for HS production. The N-deacetylase N-sulfotransferase (NDST) is a key enzyme in HS biosynthesis, directing other modifications. We show that NDST isoforms have very different roles in HS biosynthesis. Inactivation of NDST1 affects HS biosynthesis in all tissues. In embryonic liver HS from NDST1-/- mice the N-sulfation was decresed with twothirds, while the absence of NDST2 did not affect HS structure. In the absence of NDST1 in the liver, however, NDST2 is active in HS N-sulfation. In a study of embryonic stem cells lacking both NDST1 and NDST2, no N-sulfate groups could be detected. 6-O-sulfate groups were, however, still present at half of its normal level. This was an unexpected finding since 6-O-sulfotransferases have been thought to be strictly dependent on N-sulfate groups for substrate recognition. By adapting an automated method for HS analysis to mammalian tissues, we could extend our analyses to more tissues and other transgene models. We also developed a protocol to create a sensitive “fingerprint” of HS structure. With these methods we could determine the individual HS structure of different mouse tissues

Grundsyner i förändring - En jämförande intervjustudie med fem pedagoger

I föreliggande studie kommer vi att redogöra för en grupp förskollärares uppfattningar och föreställningar om förskolan, dess verksamhet och arbetssätt utifrån tre verksamhetsbegrepp: arbete, lek och inlärning. Studien lånar dessa begrepp, delar av metod och utförande samt empiri från en studie utgiven 1990 och skriven av Boel Henckel. Hon ville undersöka förskollärares och förskollärarstudenters uppfattningar och föreställningar om förskolan, samt om förskollärare handlade på samma sätt som de tänkte. Vi genomförde fem intervjustudier för att samla in vår empiri, som sedan sorterades enligt Henckels kategorier och jämfördes. Empirin som samlades in sorterades utifrån de kategorier som Henckel formulerade i sin studie, varefter emprin analyserades och jämfördes med Henckels resultat samt styrdokument. Med hjälp av en sociokulturell utgångspunkt i analysen har det sedan varit möjligt att se likheter och förändringar i resultaten och diskutera deras ursprung

Revisionsberättelsens effekter : En kvantitativ studie om sambandet mellan revisionsberättelsen och företags ekonomiska prestation

Efterfrågan att bli reviderad grundar sig i företags vilja att förse användarna av de finansiella rapporterna med trovärdig och pålitlig information. Dessa användare kan exempelvis vara de intressenter som interagerar med företaget i dess omgivning. Revisionsberättelsen har potential att fungera som en signal till ett företags intressenter och delge information om huruvida förvaltningen och företagets redovisning har utförts korrekt. En revisionsberättelse som innehåller en anmärkning från revisorn kan därmed ses som en negativ signal av intressenter som i sin tur kan välja att förändra sitt beteende gentemot företaget. Således kan företagets ekonomiska prestation och ställning påverkas av intressenternas användning av revisionsberättelsen. Vår studie behandlar svenska privata aktiebolag inom byggbranschen och deras ekonomiska prestation mellan räkenskapsåren 2008-2014. I denna studie representeras det reviderade företagets ekonomiska prestation av nyckeltalen nettoomsättning, antal anställda, soliditet, genomsnittlig skuldränta, kassalikviditet och avkastning på totalt kapital. Utöver detta inkluderas även företagens fortlevnad som en del i samlingsbegreppet ekonomisk prestation. Tidigare studier har funnit att företag som erhållit en oren revisionsberättelse följaktligen erhåller högre räntor vid ansökan om nya lån. Däremot är det relativt outforskat huruvida erhållandet av en revisionsanmärkning är associerat med en efterföljande försämring av övriga delar i företags ekonomiska situation. Utifrån detta studeras vår problemformulering som lyder: Finns det ett negativt samband mellan erhållandet av en revisionsanmärkning och den efterföljande ekonomiska prestationen för svenska privata aktiebolag inom byggbranschen? För att svara på detta har vi genomfört en kvantitativ undersökning där vi samlat in data från databasen Retriever Business. Utifrån detta datamaterial har vi sedan genomfört en bivariat analys i form av t-test, Mann-Whitney U-test och Chi2-test samt en multivariat analys i form av multipla regressionsanalyser. Resultaten från studien visar att erhållandet av en revisionsanmärkning har ett negativt samband med de reviderade företagens efterföljande förändring i soliditet, avkastning på totalt kapital samt deras fortlevnad. Dessutom finner vi ett positivt samband mellan erhållandet av en revisionsanmärkning och en efterföljande förändring i företagens genomsnittliga skuldränta. Vi kan således säga att erhållandet av en revisionsanmärkning har ett samband med vissa delar av företagens efterföljande ekonomiska prestation och ställning. Resultaten visar också att företag som erhåller en revisionsanmärkning är mer benägna att erhålla ytterligare anmärkningar under de följande tre åren. Vidare finner vi att en negativ trend i företagens soliditet, genomsnittliga skuldränta, kassalikviditet och avkastning på totalt kapital har ett samband med en efterföljande revisionsanmärkning