58 research outputs found
Synthesis of glucuronoxylan in higher and lower plants
The hemicellulose glucuronoxylan (GX) is the second most abundant polysaccharide
after cellulose in the secondary cell walls of angiosperms and contributes significantly
to the properties of wood as raw materials. Despite this, very little is known about the
biosynthesis of hemicellulose. The thesis is based on studies performed in
Physcomitrella patens, Arabidopsis thaliana, and Populus plants with the aim to
increase the understanding of glucuronoxylan synthesis, and with main focus on the
role of the IRX10 gene family.
A number of genes have proven to be involved in GX biosynthesis in Arabidopsis,
namely IRREGULAR XYLEM (IRX) 9, IRX14, IRX8, FRAGILE FIBER (FRA) 8 and
PARVUS. This thesis presents two new genes, IRX10 and its close homolog IRX10-
LIKE (L), which can now be added to the group of presumed GX biosynthesis genes. In
addition, identification and characterisation of three homologs (IRX9-L, IRX14-L and
F8H) of previously identified GX synthesis genes is described.
Complementation experiments and morphological studies confirmed redundancy
between the IRX9 and IRX9-L, IRX14 and IRX14-L, and the FRA8 and F8H pairs of
genes in Arabidopsis. A bioinformatics based approach has led to the identification of
four putative homologs in Populus trichocarpa (PtGT47A-1, PtGT47A-2, PtGT47D-1,
and PtGT47D-4) of AtIRX10, and one putative homolog from Physcomitrella
(PpGT47D). Experiments further confirmed functional conservation between the
Arabidopsis (IRX10) and Populus GT47A proteins, and partial functional conservation
between the Populus GT47D, the Physcomitrella GT47D and Arabidopsis IRX10
proteins.
The work supports the existence of an Arabidopsis GX backbone biosynthesis
complex in which AtIRX10 and AtIRX10-L form an essential component together with
AtIRX9 and AtIRX14. It also suggests that parts of the GX biosynthesis machinery are
conserved across embryophytes. Finally, work presented in this thesis indicates that the
IRX10 gene family has gone through a subfunctionalisation event during the evolution
Impaired Spleen Formation Perturbs Morphogenesis of the Gastric Lobe of the Pancreas
Despite the extensive use of the mouse as a model for studies of pancreas development and disease, the development of the gastric pancreatic lobe has been largely overlooked. In this study we use optical projection tomography to provide a detailed three-dimensional and quantitative description of pancreatic growth dynamics in the mouse. Hereby, we describe the epithelial and mesenchymal events leading to the formation of the gastric lobe of the pancreas. We show that this structure forms by perpendicular growth from the dorsal pancreatic epithelium into a distinct lateral domain of the dorsal pancreatic mesenchyme. Our data support a role for spleen organogenesis in the establishment of this mesenchymal domain and in mice displaying perturbed spleen development, including Dh +/â, Bapx1â/â and Sox11â/â, gastric lobe development is disturbed. We further show that the expression profile of markers for multipotent progenitors is delayed in the gastric lobe as compared to the splenic and duodenal pancreatic lobes. Altogether, this study provides new information regarding the developmental dynamics underlying the formation of the gastric lobe of the pancreas and recognizes lobular heterogeneities regarding the time course of pancreatic cellular differentiation. Collectively, these data are likely to constitute important elements in future interpretations of the developing and/or diseased pancreas
Utility of Pathology Imagebase for Standardization of Prostate Cancer Grading
Aims: Despite efforts to standardise grading of prostate cancer, even among experts there is still a considerable variation in grading practices. In this study we describe the use of Pathology Imagebase, a novel reference image library, for setting an international standard in prostate cancer grading.
Methods and results: The International Society of Urological Pathology (ISUP) recently launched a reference image database supervised by experts. A panel of 24 international experts in prostate pathology reviewed independently microphotographs of 90 cases of prostate needle biopsies with cancer. A linear weighted kappa of 0.67 (95% confidence interval = 0.62-0.72) and consensus was reached in 50 cases. The interobserver weighted kappa varied from 0.48 to 0.89. The highest level of agreement was seen for Gleason score (GS) 3 + 3 = 6 (ISUP grade 1), while higher grades and particularly GS 4 + 3 = 7 (ISUP grade 3) showed considerable disagreement. Once a two-thirds majority was reached, images were moved automatically into a public database available for all ISUP members at www.isupweb.org. Non-members are able to access a limited number of cases.
Conclusions: It is anticipated that the database will assist pathologists to calibrate their grading and, hence, decrease interobserver variability. It will also help to identify instances where definitions of grades need to be clarified
Imaging the pancreas : new aspects on lobular development and adult constitution
The mouse pancreas is a mixed exocrine and endocrine glandconsisting of three lobular compartments: the splenic, duodenal and gastric lobes. During embryogenesis, the pancreas forms from two progenitor populations located on the dorsal and ventral side of the primitive gut tube. These anlagen are brought in close proximity as the gut elongates and rotates, and fuse to form a single organ. The splenic and duodenal lobes develop from the dorsal and ventral anlagen, respectively. In the adult pancreas, exocrine tissue secretes digestive enzymes intothe gut lumen to support nutrient uptake. The endocrine Islets of Langerhans are scattered throughout the exocrine tissue and aid in regulation of energy homeostasis through the secretion of hormones. One of the key players in energy homeostasis is the pancreatic Ă-cell, which is the most abundant cell type of the islets. The ÎČ-cells regulates blood glucose levels through the action of insulin. Conditions where this regulation does not function properly are gathered under the common name of Diabetes mellitus. Type 1 diabetes (T1D) is characterized by insulin deficiency due to autoimmune destruction of the Ă-cells. Using recently developed protocols for optical projection tomography (OPT) whole-organ imaging, we have revealed new spatial and quantitative aspects on Ă-cell mass dynamics and immune infiltration during the course of T1D development in the non-obese diabetic (NOD) mouse model. We show that although immune infiltration appears to occur asynchronously throughout the organ, smaller islets, mainly located in the periphery of the organ, preferentially loose their Ă-cells during early stages of disease progression. Larger islets appear more resistant to the autoimmune attack and our data indicate the existence of a compensatory proliferative capacity within these islets. We also report the appearance of structures resembling tertiary lymphoid organs (TLOs) in association with the remaining islets during later phases of T1D progression. OPT has already proven to be a useful tool for assessments of Ă-cellmass in the adult mouse pancreas. However, as with other techniques, previous protocols have relied on a tedious degree of manual postivacquisition editing. To further refine OPT-based assessment of pancreatic Ă-cell mass distribution in the murine pancreas, we implemented a computational statistical approach, Contrast-Limited Adaptive Histogram Normalisation (CLAHE), to the OPT projection data of pancreata from C57Bl/6 mice. This methodology provided increased islet detection sensitivity, improved islet morphology and diminished subjectivity in thresholding for reconstruction and quantification. Using this approach, we could report a substantially higher number of islets than previously described for this strain and provide evidence of significant differences in islet mass distribution between the pancreatic lobes. The gastric lobe stood out in particular and contained a 75% higher islet density as compared to the splenic lobe. Although the development of the early pancreatic buds has been relatively well studied, later morphogenetic events are less clear and information regarding the formation of the gastric lobe has largely been missing. Using OPT we have generated a quantitative three-dimensional road map of pancreatic morphogenesis in the mouse. We show that the gastric lobe forms as a perpendicular outgrowth fromthe stem of the dorsal pancreas at around embryonic day (e) 13.5, which grows into a mesenchymal domain overlaying the pyloric sphincter and proximal part of the glandular stomach. By analyzing mutant mice with aberrant spleen development, we further demonstrate that proper formation of the gastric lobe is dependent on the initial formation of the closely positioned spleen, indicating a close interplay between pancreatic and splenic mesenchyme during development. Additionally, we show that the expression profile of markers for pancreatic multipotent progenitors within the pancreas is heterogenous with regards to lobular origin. Altogether, our studies regarding the morphogenesis and adult constitution of the mouse pancreas recognize lobular heterogeneities that add important information for future interpretations of this organ
The City as a Resource in History Teaching : A Thematic Analysis of how Students Perceive the Importance of Place when Learning Local History
I de skandinaviska lÀnderna Àr det mÄnga lÀrare som anvÀnder nÀrmiljön i undervisningen, men trots detta finns det lite forskningsbaserad kunskap om det praktiska genomförandet. Den forskning som finns Àr till största del inriktad pÄ miljö, vetenskapliga och geografiska Àmnen och fÄ mot historieÀmnet. Malmö Stad har gjort en satsning att ta fram lektionsmaterial till skolorna dÀr platsbaserat lÀrande Àr kopplat till historieundervisningen. Den hÀr studien handlar om elever, som anvÀnt sig av lektionsmaterialet, uppfattar att platser som inkluderas i undervisningen pÄverkar deras lÀrande. Studiens frÄgestÀllningar: PÄ viket sÀtt inkluderar eleverna ett historiskt perspektiv i sina berÀttelser om den valda platsen? PÄ vilket sÀtt beskriver eleverna att platsmedveten undervisning pÄverkar deras lÀrande? I den hÀr kvalitativa studien med abduktiv ansats undersöks om den enskilda eleven upplever att de fysiska platser i staden som inkluderas i historieundervisningen ses som en lÀranderesurs. Detta har gjorts genom semistrukturerade intervju för att ge var och en av respondenterna möjlighet att utveckla sina svar till sÄ stor del som möjligt, men Àven att kunna ge relevanta följdfrÄgor. Respondenternas berÀttelser har sedan analyserats utifrÄn analysmetoden tematisk analys. Tematisk analys Àr en metod för att identifiera, analysera och presentera mönster i förhÄllande till forskningsfrÄgorna och Àr inte knutet till ett specifikt teoretiskt ramverk. Forskaren utgÄr frÄn tidigare forskning dÀr resultaten har visat att platsbaserat lÀrande och utomhuspedagogik har positiva effekter pÄ elevernas lÀrande. I studien ingÄr 16 elever, tvÄ frÄn sprÄkintroduktionen, nio frÄn Ärskurs 5 och fem frÄn Ärskurs 8. UtifrÄn elevernas berÀttelser dras slutsatsen att de positiva effekter som lÀrarna planerade för, att förstÀrka och fördjupa klassrumsundervisningen, aktivera olika sinnen, ökad autenticitet, erfarenheter, konkretisering av abstrakt innehÄll och variation för att möta olika elevers behov, kunde utlÀsas i 14 av de 16 respondenternas svar. Eleverna inkluderade ett historiskt perspektiv i sina berÀttelser. Varje individ har sin uppfattning om lÀrande och nÀr man lÀr. Med olika exempel beskrev 14 av de 16 respondenterna att platserna pÄ nÄgot sÀtt ökat deras lÀrande, men att det Àr en pusselbit av flera
En kartlÀggning av arbetet med slutdokumentation : En fallstudie
Byggprocessen Ă€r komplex, stor och vĂ€ldigt omfattande. Det innefattar mĂ„nga delar och samarbeten mellan flera olika aktörer. Inom byggbranschen sĂ„ tittas det hela tiden pĂ„ hur det kan optimeras genom att förbĂ€ttra logistiklösningar, minska slöseri och fler lösningar för att spara pĂ„ bĂ„de pengar och miljö. Det finns flera delar i byggprocessen och en del Ă€r slutskedet/överlĂ€mnandet, vilken Ă€r den avslutande delen av projekten dĂ€r bestĂ€llaren övertar slutprodukten frĂ„n den utförande entreprenören. Slutskedet innefattar bland annat slutbesiktning och överlĂ€mnande av slutdokumentation/slutpĂ€rm. Just upprĂ€ttandet och överlĂ€mnandet av slutdokumentationen Ă€r ett arbete som inte undersökts mycket och upplevs ej i byggbranschen som ett uppskattat arbete och hamnar ofta i klĂ€m och utförs i sista sekund med bristande kvalitet. Den hĂ€r rapporten Ă€r det avslutande arbetet för en Civilingenjörsexamen inom VĂ€g- och Vattenbyggnad och avhandlar en studie kring just slutdokumentationsprocessen. Studien har genomförts i samarbete med Skanska Sverige AB och har fokuserat pĂ„ att kartlĂ€gga organisationens arbete kring slutdokumentation, samt att identifiera förbĂ€ttringsmöjligheter inom omrĂ„det. Det Ă€r en generell kartlĂ€ggning och Ă€r inte specificerad pĂ„ nĂ„got specifikt projekt och Ă€r begrĂ€nsad till att endast undersöka entreprenörens arbete med slut-dokumentation.Syftet med studien Ă€r att öka förstĂ„elsen för slutdokumentationsupprĂ€ttandet och att undersöka hur organisationen tycker arbetet fungerar idag, vilka för och nackdelar det finns med dagens metoder samt hur de önskar att det ska fungera i framtiden. Det Ă€r ett komplext Ă€mne, slutdokumentation, dĂ€rför har en kvalitativ metod i form av en intervjustudie utförts. Utöver intervjustudie har ocksĂ„ en litteraturstudie utförts samt ett fokusgrupptillfĂ€lle för upprĂ€ttande av processkartlĂ€ggning via SIPOC (suppliers, inputs, process, outputs, customers) och BPMN (business process modeling notation). Sex stycken intervjuer hölls och ett fokusgrupptillfĂ€lle med fyra medarbetare, medarbetarna frĂ„n bĂ„de intervjuerna och fokusgruppen hade blandade befattningar och olika lĂ„ng arbetserfarenhet. Resultatet mynnade ut i processkartlĂ€ggningar pĂ„ hur processen ser ut idag, bĂ„de med avseende pĂ„ externa beroenden och de interna processerna. Intervjustudien visade pĂ„ att mĂ„nga delar av processen beror av hur insatt bestĂ€llaren av projektet Ă€r samt hur engagerad den Ă€r kring slutdokumentation. Ett ytterligare âproblemâ som identifierades var att syftet med slutdokumentation Ă€r vĂ€ldigt splittrat bland organisationen. Det finns en otydlighet kring vad syftet med arbetet Ă€r. Intervjustudien visar pĂ„ att vissa av medarbetarna ser pĂ„ slutdokumentationen endast som en âpappersproduktâ. De förbĂ€ttringsmöjligheter som identifierats Ă€r att medarbetarna önskar att det finns bĂ€ttre rutiner kring slutdokumentationsprocessen. Det visade Ă€ven pĂ„ en stor önskan att fĂ„ lyfta in arbetet med slutdokumentation tidigt i projektet för att inte behöva sitta med arbetet i slutet av projektet och stressa ihop det. Ett standardiserat arbete inom organisationen önskas.The construction process is complex and very substantial. It involves many different parts and interaction between different working parties. Within the construction industry they always seem to be looking for improvements in logistics, how to decrease waste and more solutions on how to lower costs and the environmental impacts. There are several parts in the construction process, one is the final stage/delivery, which is the part where the entrepreneur hands over the project to the customer. The final stage includes, amongst other, final inspection and delivery of the final project documents. The establishment and delivery of the final project documents is a work not appreciated by the industry and is often overlooked and comes in second hand with low quality. This report is the final work at the Civil engineering program and includes a study especially on the work for the final project documents. The study has been completed together with Skanska Sweden AB and have been focused on mapping out how the work is accomplished today, also to look at possibilities of improvement in this work area. It is a general mapping which is not specified on one specific project, it is also only focused on the entrepreneursâ perspective of the process. The purpose of the study is to increase the knowledge of the final project documents establishment, and to investigate how the organization experience the process today. It focuses on what the advantages and disadvantages are today and on how the workers want it to be in the future. It is considered a complex subject, final project documents establishment, that is why a qualitative method has been used, in form of a study with interviews. Addition to the interviews a literature study and a focus group study has been accomplished. The focus group study is used for establishing a process map via SIPOC (suppliers, inputs, process, outputs, customers) and BPMN (business process modeling notation). Six interviews and one focus group including four workers was accomplished. The workers in both the interviews and the focus group includes people with different work positions and years of work experience. The result fell into process mapping of how the work is done today both depending on the external forces and the internal processes. The interview study showed that a lot in the process is dependent on how the customer acts. Another identified âproblemâ is how the purpose of the final project documents is unknown within the organization. There is a vagueness in what it really is. The study shows that some of the workers sees the final project documents only as papers that are delivered to the customers, barely nothing else. The improvements that were identified was the fact that the workers want the beginning of the establishment of these documents to start earlier in the construction process. They also want better routines considering the process. They want a standardized way on establishing the final project documents, within the organization
En kartlÀggning av arbetet med slutdokumentation : En fallstudie
Byggprocessen Ă€r komplex, stor och vĂ€ldigt omfattande. Det innefattar mĂ„nga delar och samarbeten mellan flera olika aktörer. Inom byggbranschen sĂ„ tittas det hela tiden pĂ„ hur det kan optimeras genom att förbĂ€ttra logistiklösningar, minska slöseri och fler lösningar för att spara pĂ„ bĂ„de pengar och miljö. Det finns flera delar i byggprocessen och en del Ă€r slutskedet/överlĂ€mnandet, vilken Ă€r den avslutande delen av projekten dĂ€r bestĂ€llaren övertar slutprodukten frĂ„n den utförande entreprenören. Slutskedet innefattar bland annat slutbesiktning och överlĂ€mnande av slutdokumentation/slutpĂ€rm. Just upprĂ€ttandet och överlĂ€mnandet av slutdokumentationen Ă€r ett arbete som inte undersökts mycket och upplevs ej i byggbranschen som ett uppskattat arbete och hamnar ofta i klĂ€m och utförs i sista sekund med bristande kvalitet. Den hĂ€r rapporten Ă€r det avslutande arbetet för en Civilingenjörsexamen inom VĂ€g- och Vattenbyggnad och avhandlar en studie kring just slutdokumentationsprocessen. Studien har genomförts i samarbete med Skanska Sverige AB och har fokuserat pĂ„ att kartlĂ€gga organisationens arbete kring slutdokumentation, samt att identifiera förbĂ€ttringsmöjligheter inom omrĂ„det. Det Ă€r en generell kartlĂ€ggning och Ă€r inte specificerad pĂ„ nĂ„got specifikt projekt och Ă€r begrĂ€nsad till att endast undersöka entreprenörens arbete med slut-dokumentation.Syftet med studien Ă€r att öka förstĂ„elsen för slutdokumentationsupprĂ€ttandet och att undersöka hur organisationen tycker arbetet fungerar idag, vilka för och nackdelar det finns med dagens metoder samt hur de önskar att det ska fungera i framtiden. Det Ă€r ett komplext Ă€mne, slutdokumentation, dĂ€rför har en kvalitativ metod i form av en intervjustudie utförts. Utöver intervjustudie har ocksĂ„ en litteraturstudie utförts samt ett fokusgrupptillfĂ€lle för upprĂ€ttande av processkartlĂ€ggning via SIPOC (suppliers, inputs, process, outputs, customers) och BPMN (business process modeling notation). Sex stycken intervjuer hölls och ett fokusgrupptillfĂ€lle med fyra medarbetare, medarbetarna frĂ„n bĂ„de intervjuerna och fokusgruppen hade blandade befattningar och olika lĂ„ng arbetserfarenhet. Resultatet mynnade ut i processkartlĂ€ggningar pĂ„ hur processen ser ut idag, bĂ„de med avseende pĂ„ externa beroenden och de interna processerna. Intervjustudien visade pĂ„ att mĂ„nga delar av processen beror av hur insatt bestĂ€llaren av projektet Ă€r samt hur engagerad den Ă€r kring slutdokumentation. Ett ytterligare âproblemâ som identifierades var att syftet med slutdokumentation Ă€r vĂ€ldigt splittrat bland organisationen. Det finns en otydlighet kring vad syftet med arbetet Ă€r. Intervjustudien visar pĂ„ att vissa av medarbetarna ser pĂ„ slutdokumentationen endast som en âpappersproduktâ. De förbĂ€ttringsmöjligheter som identifierats Ă€r att medarbetarna önskar att det finns bĂ€ttre rutiner kring slutdokumentationsprocessen. Det visade Ă€ven pĂ„ en stor önskan att fĂ„ lyfta in arbetet med slutdokumentation tidigt i projektet för att inte behöva sitta med arbetet i slutet av projektet och stressa ihop det. Ett standardiserat arbete inom organisationen önskas.The construction process is complex and very substantial. It involves many different parts and interaction between different working parties. Within the construction industry they always seem to be looking for improvements in logistics, how to decrease waste and more solutions on how to lower costs and the environmental impacts. There are several parts in the construction process, one is the final stage/delivery, which is the part where the entrepreneur hands over the project to the customer. The final stage includes, amongst other, final inspection and delivery of the final project documents. The establishment and delivery of the final project documents is a work not appreciated by the industry and is often overlooked and comes in second hand with low quality. This report is the final work at the Civil engineering program and includes a study especially on the work for the final project documents. The study has been completed together with Skanska Sweden AB and have been focused on mapping out how the work is accomplished today, also to look at possibilities of improvement in this work area. It is a general mapping which is not specified on one specific project, it is also only focused on the entrepreneursâ perspective of the process. The purpose of the study is to increase the knowledge of the final project documents establishment, and to investigate how the organization experience the process today. It focuses on what the advantages and disadvantages are today and on how the workers want it to be in the future. It is considered a complex subject, final project documents establishment, that is why a qualitative method has been used, in form of a study with interviews. Addition to the interviews a literature study and a focus group study has been accomplished. The focus group study is used for establishing a process map via SIPOC (suppliers, inputs, process, outputs, customers) and BPMN (business process modeling notation). Six interviews and one focus group including four workers was accomplished. The workers in both the interviews and the focus group includes people with different work positions and years of work experience. The result fell into process mapping of how the work is done today both depending on the external forces and the internal processes. The interview study showed that a lot in the process is dependent on how the customer acts. Another identified âproblemâ is how the purpose of the final project documents is unknown within the organization. There is a vagueness in what it really is. The study shows that some of the workers sees the final project documents only as papers that are delivered to the customers, barely nothing else. The improvements that were identified was the fact that the workers want the beginning of the establishment of these documents to start earlier in the construction process. They also want better routines considering the process. They want a standardized way on establishing the final project documents, within the organization
Laborations for Intregration and To Learn Natural Science? : Aspects on an Investigatory Session.
I den hÀr studien har en naturvetenskaplig laboration genomförts som en gemensam aktivitet för en gymnasieklass som lÀser Biologi 1 och en sprÄkintroduktionsklass som lÀser NO. Aktiviteten har sedan utvÀrderats med avseende pÄ elevernas tillÀgnande av det naturvetenskapliga innehÄllet, deras anvÀndande av naturvetenskapligt sprÄk, vilka kommunikationsvÀgar som uppstod, elevernas försök till samarbete, samt elevernas och lÀrarnas subjektiva upplevelser. Studien visade att den hÀr typen av aktiviteter Àr genomförbara pÄ ett mycket heterogent elevunderlag avseende bÄde etniska-, sociala och förkunskapsmÀssiga faktorer. De naturvetenskapliga laborationerna har dÀrmed en potential i att fungera som verktyg bÄde i ÀmnesinlÀrning och som arena för integration. Vidare visade studien pÄ behovet av kommunikationsverktyg utöver listor med Àmnesspecifika ord och begrepp bÄde för elever med svenska som andrasprÄk och med svenska som modersmÄl. För utveckling av det naturvetenskapliga sprÄket föreslÄs en utförligare uppföljning av laborationsaktiviteten Àn den som gjordes inom ramen för den hÀr studien
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