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#rethinktextile : En ny textil framtidÅberg, Frida January 2015 (has links)
Textiles are a natural element in our everyday life. The clothes we wear are part of our identity and tell something about who we are or want to be. Clothes can be an interest as well as a source of inspiration. However, a great deal of the global textile production has a negative influence on the environment. Despite alarming reports the textile consumption in Sweden is still high and is expected to increase further. We need to revaluate the value of textiles and change our consumption behaviors in order to create a more sustainable society. This essay will highlight the subject textile sustainability and the overall purpose is to make consumers aware of how today´s textile industries affect the environment as well as how our personal textile consumption is a part of that. The main purpose of the study is to examine how alternative consumption patterns could lead to a more sustainable textile consumption in the future. A participatory design approach with several methods were used throughout the work. Some of these methods were developed in action together with visual materials to support the interviewee. Interviews with experts as well as consumers and a number of workshops were accomplished. According to the results from the interviews with experts and consumers, as well as from the surveys and events, it was concluded that the consumers need to be more conscious of the textiles´ influence on the environment and that they need to change both their own consumption behaviors and their point of view on textiles. With that in mind, the digital platform #rethinktextile, was developed to help consumers to make sustainable textile choices. The intention with #rethinktextile is to collect knowledge about textile and sustainability on one site to make it possible for consumers to act in a more sustainable way when consuming textiles. / Textilier är ett naturligt inslag i vår vardag. De kläder vi bär är identitetsskapande och säger någonting om vilka vi är eller vill vara. För många är kläder ett intresse och en källa till inspiration. Stora delar av världens textilproduktion har dock en negativ påverkan på miljön. Trots alarmerande rapporter fortsätter ändå textilkonsumtionen i Sverige att vara hög och förväntas stiga ytterligare. Vi behöver omvärdera textiliers värde och förändra våra konsumtionsbeteenden för att skapa ett mer hållbart samhälle. Denna uppsats vill belysa ämnet textil hållbarhet och det övergripande syftet är att uppmärksamma konsumenter på den miljöpåverkan dagens textilindustri ger upphov till och hur vår personliga textilkonsumtion är en del i detta. Huvudsyftet med studien är att undersöka hur alternativa konsumtionsmönster kan leda till en mer hållbar textilkonsumtion i framtiden. Med en inkluderande designprocess som grund användes flera olika metoder varav några utvecklades under arbetets gång tillsammans med visuella intervjustöd. Intervjuer genomfördes med sakkunniga personer inom textil och mode, produktion, konsumtion, återanvändning och återvinning. Dessutom gjordes intervjuer och workshops med en rad konsumenter/användare. Av resultatet från både intervjuer, enkätsvar och olika event framgick bland annat att konsumenter behöver bli mer medvetna om textiliers miljöpåverkan samt förändra både sitt konsumtionsbeteende och sitt synsätt på textilier. Därför utvecklades ett designförslag, #rethinktextile, en digital plattform med textilt hållbarhetsfokus riktat till konsumenter. Genom plattformen kan miljöorganisationer och myndigheter på ett samlat sätt sprida kunskap och genom olika verktyg och aktiviteter inspirera konsumenter till en mer miljömedveten textilkonsumtion.
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Fear of re-injury and other intrinsic factors are associated with return to sport after anterior cruciate ligament reconstructionRoss, Cheryl Anne 04 1900 (has links)
Thesis (MScPhysio)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The anterior cruciate ligament is the most commonly injured ligament in the knee, with
only one third of athletes returning to their pre-injury level of sport. Identifying intrinsic
factors associated with an increased likelihood of return to sport may improve the
surgical outcome. A systematic review following the Preferred Reporting Items for
Systematic Reviews and Meta-Analyses guidelines was performed. The objective was to
systematically appraise publications describing intrinsic factors which may be associated
with return to sport, after anterior cruciate ligament reconstruction. A comprehensive
eligibility checklist was composed. Methodological quality appraisal of cohort studies
revealed that high quality studies were included in the review. A descriptive synthesis of
the findings associating intrinsic factors with return to sport was performed. Ten studies
were included. The most important finding was the association of fear of re-injury
preventing return to sports participation. Knee function did not always correspond with
the likelihood of returning to sport. Younger athletes and competitive, male athletes
appeared more likely to return. Across these studies, the 141 athletes not returning to
pre-injury sport were questioned as to the reason for non return. An average of 35% (49
athletes) cited fear of re-injury as the reason. Fear of re-injury was thus investigated
further as it could be considered in the post-operative management of anterior cruciate
ligament reconstruction. In a qualitative study with supplemental cross-sectional
analysis, factors informing fear of re-injury were explored. Male and female athletes,
aged 17-50 years were included (n=59). Reconstruction procedures using any graft type
were included; however revision and multi-ligament reconstruction was excluded.
Twenty-four participants (41%) did not return to the pre-injury sport. Those citing fear of
re-injury as the only reason for not-retuning to sport were interviewed (n=12). Thus,
those who did not return to pre-injury type and level of sport despite good knee function.
Athletes’ experiences informing fear of re-injury were explored by semi-structured
interviews. Data analysis was performed by content analysis. Codes were allocated and
categorised and these categories were synthesised into themes. The Qualitative review
guidelines – RATS were followed. From the participant interviews, four themes emerged:
undergoing the surgery and recovery again, nature of the pre-injury sport imposing risk
of re-injury, personality traits, and social priorities. An accelerated rehabilitation
programme was suggested to improve the post–operative experience. The
supplementary analysis revealed athletes younger than 20 years of age were more likely
to return to sport. Modifiable fears include pain, length of rehabilitation, mechanism of
injury and psychological aspects. Pain management, motivation and education are
important considerations post-operatively and during rehabilitation. Clinicians should be
aware of factors informing fear of re-injury on an individual basis to develop a tailored
management plan. / AFRIKAANSE OPSOMMING: OPSOMMING
Die anterior kruisligament is die mees algemeen beseerde ligamente in die knie, met
slegs een derde van die atlete wat terugkeer na hul pre-besering vlak van sport.
Identifisering van intrinsieke faktore wat verband hou met 'n verhoogde moontlikheid van
terugkeer na sport kan die chirurgiese uitkoms verbeter. 'n Sistematiese oorsig wat die
Voorkeur Verslag Items vir Sistematiese oorsig en Meta-ontledingsriglyne volg, is
uitgevoer . Die doel was om stelselmatig publikasies, wat intrinsieke faktore beskryf wat
verband hou met terugkeer na sport na anterior kruisligament rekonstruksie, te
beoordeel. 'n Omvattende kontrolelys is saamgestel. Metodologiese kwaliteit
beoordeling van ‘n groep studies het 'n hoë gehalte studie aan die lig gebring, wat
ingesluit is in die oorsig. 'n Beskrywende sintese van die bevindinge wat intrinsieke
faktore met die terugkeer na sport assosieer, is uitgevoer. Tien studies is ingesluit. Die
belangrikste bevinding wat terugkeer na sportdeelname verhinder was die vrees van
herbesering. Kniefunksie het nie altyd ooreengestem met die moontlikheid van terugkeer
na sport nie. Jonger atlete en wedywerende manlike atlete was meer geneig om terug te
keer. In al die ingesluite studies, is die 141 atlete wat nie teruggekeer het na sport voorbesering
ondervra oor die rede vir nie terugkeer. 'n Gemiddeld van 35% (49 atlete) het
vrees vir herbesering as rede aangevoer. Vrees vir herbesering is dus verder ondersoek,
as oorwegende faktor in die post-operatiewe bestuur van anterior kruisligament
rekonstruksie. In 'n primêre, kwalitatiewe studie met aanvullende deursnee-analise, is
die redes vir die vrees vir herbesering ondersoek. Manlike en vroulike atlete, tussen die
ouderdomme van 17-50 jaar is ingesluit (n = 59). Rekonstruksie prosedures deur enige
soort oorplanting is ingesluit; hersiening en verskeie ligament rekonstruksie is egter
uitgesluit. Vier-en-twintig deelnemers (41%) het nie teruggekeer na die pre-besering
sport nie. Diegene wat vrees vir herbesering as die enigste rede vir nie terugkering na sport aanvoer, is onderhoude mee gevoer (n = 12). Dus, diegene wat nie teruggekeer
het na pre-besering, tipe en vlak, van sport ten spyte van goeie knie funksie. Die redes
vir die vrees vir herbesering is ondersoek deur semi-gestruktureerde onderhoude. Dataanalise
is uitgevoer deur die inhoud / tematiese analise. Kodes is toegeken en
gekategoreer. Hierdie kategorieë is herverdeel in temas. Uit die deelnemer onderhoude,
het vier temas na vore gekom: die operasie en herstel proses, die aard van die prebesering
sport as risiko vir herbesering, persoonlikheidseienskappe en sosiale prioriteite.
'n Versnelde rehabilitasieprogram is voorgestel om die post-operatiewe ervaring te
verbeter. Die aanvullende analise het getoon dat atlete jonger as 20 jaar oud meer
geneig was om terug te keer na die sport. Aanpasbare oorsake van vrees sluit in pyn,
die lengte van rehabilitasie, meganisme van besering en sielkundige aspekte. Pyn
bestuur, motivering en opvoeding is belangrike oorwegings post-operatief en tydens
rehabilitasie. Dokters en fisioterapeute moet bewus wees van die vrees vir herbesering
en die veranderbare oorsake daarvan ondersoek op 'n individuele basis om 'n pasient
spesifieke bestuursplan te ontwikkel.
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Birefringent properties of the human cornea in vivo : towards a new model of corneal structureMisson, Gary P. January 2012 (has links)
The fundamental corneal properties of mechanical rigidity, maintenance of curvature and optical transparency result from the specific organisation of collagen fibrils in the corneal stroma. The exact arrangement of stromal collagen is currently unknown but several structural models have been proposed. The purpose of the present study is to investigate inconsistencies between current x‐ray derived structural models of the cornea and optically derived birefringence data. Firstly, the thesis reviews the current understanding of corneal structure, particularly in relation to corneal birefringence. It also reviews and develops the different analytical approaches used to model optical biaxial behaviour, particularly as applied to predict corneal optical phase retardation. The second part develops a novel technique of elliptic polarization biomicroscopy (EPB), enabling study of corneal birefringence in vivo. Using EPB, the pattern of corneal retardation is recorded for a range of human subjects. This dataset is then used to investigate both central and peripheral corneal birefringence as well as the corneal microstructure. A key finding is that the central parts of the cornea exhibit a retardation pattern compatible with a negative biaxial crystal, whereas the peripheral corneal regions do not. Furthermore, within the central regions of the cornea, orthogonal confocal conic fibrillar structures are identified which resemble the analytically derived contours of equal refractive index of an ideal negative biaxial crystal. The third part of this work presents a synthesis of previous published experimental, anatomical and theoretical findings and the experimental results presented in this thesis. Based on these findings, a novel corneal structural model is proposed that comprises overlapping spherical elliptic structural units. Finally, ensuing biomechanical and clinical consequences of the spherical elliptic structural model and of the EPB technique are discussed including their potential diagnostic and surgical applications.
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Claiming Images: The Production and Preservation of Desire in Richard Prince's Re-PhotographyGallagher, Meghan M 01 January 2015 (has links)
This thesis explores the re-photography of contemporary artist, Richard Prince. Using Lacanian theories of the gaze and of the drive cycle, it attempts to establish desire as the central theme of Prince's work. It looks primarily at the Cowboys, Girlfriends, and New Portraits, in order to combat the dominant perception of Prince's work as critical commentary on contemporary consumer culture.
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Skin regeneration in deep second-degree scald injuries either by infusion pumping or topical application of recombinant human erythropoietin gelGiri, Priya, Ebert, Sabine, Braumann, Ulf-Dietrich, Kremer, Mathias, Giri, Shibashish, Machens, Hans-Günther, Bader, Augustinus 11 May 2015 (has links) (PDF)
Large doses of recombinant growth factors formulated in solution form directly injected into the body is usual clinical practice in treating second-degree scald injuries, with promising results, but this approach creates side effects; furthermore, it may not allow appropriate levels of the factor to be sensed by the target injured tissue/organ in the specific time frame, owing to complications arising from regeneration. In this research, two delivery methods (infusion pumping and local topical application) were applied to deliver recombinant human erythropoietin (rHuEPO) for skin regeneration. First, rHuEPO was given in deep second-degree scald injury sites in mice by infusion pump. Vascularization was remarkably higher in the rHuEPO pumping group than in controls. Second, local topical application of rHuEPO gel was given in deep second-degree scald injury sites in rats. Histological analysis showed that epithelialization rate was significantly higher in the rHuEPO gel-treated group than in controls. Immunohistochemical studies showed that the rHuEPO gel-treated group showed remarkably higher expression of skin regeneration makers than the control group. An accurate method for visualization and quantification of blood vessel networks in target areas has still not been developed up to this point, because of technical difficulties in detecting such thin blood vessels. A method which utilizes a series of steps to enhance the image, removes noise from image background, and tracks the vessels edges for vessel segmentation and quantification has been used in this study. Using image analysis methods, we were able to detect the microvascular networks of newly formed blood vessels (less than 500 μm thickness), which participate in the healing process, providing not only nutrition and oxygen to grow tissues but also necessary growth factors to grow tissue cells for complete skin regeneration. The rHuEPO-treated group showed higher expression of stem cell markers (CD 31, CD 90, CD 71, and nestin), which actively contribute to in-wound-healing processes for new hair follicle generation as well as skin regeneration. Collectively, both rHuEPO group pumping into the systemic circulation system, and injection into the local injury area, prompted mice and rats to form new blood vessel networks in scald injury sites, which significantly participate in the scald healing process. These results may lead to the development of novel treatments for scald wounds.
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Rening av avloppsvatten med anaerob membranbioreaktor och omvänd osmos / Wastewater treatment with anaerobic membrane bioreactor and reverse osmosisGrundestam, Jonas January 2006 (has links)
<p>This master's theses was carried out on assignment from Stockholm Vatten AB as a part of a project developing new waste water treatment techniques. The goal of the theisis has been to evaluate an anaerobic membrane bioreactor for treatment of waste water from Hammarby Sjöstad. The bioreactor has not been heated and the main interest has been to study the gas production, power consumption and the reduction of organic matter and nutrients.</p><p>The system has been completed with a reverse osmosis unit and a total of four batch runs have been made with good results. The use of reverse osmosis allows nutrient in the waste water to be reintroduced into circulation as the reverse osmosis concentrate can be used as crop nutrient.</p><p>The membrane unit is of VSEP ("Vibratory Shear Enhanced Processing") type and an extensive membrane test has been conducted. This so called L-test helped determine the most suitable type of membrane for the system to allow a higher ±ux and thus lower power consumption. The L-test gave good results and a new membrane with a poresize diameter of 0,45 μm was used.</p><p>The organic load on the bioreactor has been more or less constant, around 0,7 kg COD/day, during the seven weeks of testing. The reduction over the entire system including reverse osmosis has been large, around 99 % regarding organic matter and phosporus and 93 % for nitrogen, making the system suitable for waste water treatment except for high power consumption, around 2 kWh/m3. The production of methanegas has worked although it has been quite low, with average values of 0,13 m3 CH4/kg reduced COD.</p> / <p>Examensarbetet är utfört på uppdrag av Stockholm Vatten AB som en del av det pilotprojekt som utvärderar nya tekniker för avloppsvattenrening för Hammarby Sjöstad. Målsättningen med studien har varit att utvärdera ett system bestående av en anaerob membranbioreaktor för behandling av avloppsvatten från Hammarby Sjöstad. Bioreaktorn har inte varit uppvärmd och det som har studerats är reningseffekten, biogasproduktionen samt energiåtgången.</p><p>Systemet har även innefattat en omvänd osmosanläggning och totalt har fyra försök med denna gjorts med goda resultat. Analyser har koncentrerats till att utvärdera reduktion av organiskt material över membranbioreaktorn och av närsalter och metaller över omvänd osmos anläggningen. Bakgrunden till att använda omvänd osmos är att öka återföringen av näringsämnen från avloppsvatten. Resultatet av försöken med omvänd osmos gav ett koncentrat med högt näringsinnehåll och låg halt av tungmetaller vilket ger möjligheten att sprida det på åkermark.</p><p>Membranenheten är av typen VSEP ("Vibratory Shear Enhanced Processing") och ett membrantest har även utfötts för att finna det membran som passar systemet bäst med avseende på flöde och energiförbrukning. Det så kallade L-testet var omfattande och gav en klar bild över vad som skulle vara det bästa membranet. Det membran som visade sig passa systemet bäst var ett membran med en porstorlek på 0,45 μm. Belastningen av organiskt material på reaktorn under försöksperiodens sju veckor har varit mer eller mindre konstant och låg, cirka 0,7 kg COD/dygn. Reduktionen över hela systemet inklusive omvänd osmosanläggningen med avseende på organiskt material och fosfor har varit mycket hög, omkring 99 %. Reduktionen av kväve var som högst 93 %. Gasproduktionen har fungerat och har i genomsnitt varit omkring 0,13 m3 CH4/kg reducerad COD.</p><p>Energiförbrukningen för systemet i motsvarande fullskala blev omkring 2 kwh/m3.</p>
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Hydrogen / Deuterium Exchange and Fragmentation of Biomolecules to Probe Gas Phase Structure and EnergeticsHerrmann, Kristin Ann January 2005 (has links)
Presented in this dissertation are FT-ICR H/D exchange and fragmentation studies of protonated peptides for the purpose of better understanding gas phase conformation and protonation motifs, and their affect on fragmentation patterns. In addition, a new ion activation method is developed to enhance the abundance of higher energy fragmentation pathways, thereby providing additional structural and/or mechanistic information.Studies to probe the relay mechanism of H/D exchange in small, model peptides found that residue position, proline configuration, and availability of the termini have a measurable effect on the H/D exchange behavior reflective of different conformation / protonation motifs.Charge remote cleavage C-terminal to aspartic acid was studied with the fixed charge derivative tris(2,4,6-trimethoxyphenyl) phosphonium (tTMP-P+). Ab initio calculations demonstrate that tTMP-P+ cannot activate the proposed aspartic acid nucleophile, the acidic side chain hydrogen initiates cleavage. Despite the absence of an ionizing proton, the derivatized peptide P+LDIFSDF (where P+ = tTMP-P+) exchanges three acidic hydrogens for deuterium. This supports the proposed aspartic acid cleavage mechanism that occurs without the direct involvement of an ionizing proton because acidic protons are able to participate in H/D exchange in the absence of an added proton. In addition, H/D exchange of P+LDIFSDF analogues provides insight into the sites and mechanisms of H/D exchange.H/D exchange to separate distinct peptide populations with differing rates and their subsequent fragmentation demonstrate that conformation / protonation motif affects the fragmentation spectrum observed. Studies of [P+LDIFSDF + H]2+, [RPPGFSPFR + 2H]2+ (bradykinin), and [RVYIFPF + 2H]2+ show that at least two distinct structures exist with different rates of H/D exchange and different fragmentation patterns. The overall MS/MS spectrum is a linear combination of all conformations and protonation motifs. In addition, fragmentation of labeled populations suggests that complementary bn+ / ym-n+ ion pairs are being formed from doubly-charged precursor by the same mechanism.SORI-RE CID is a new FT-ICR ion activation method based on the combination of sustained off-resonance irradiation (SORI) and on-resonant excitation (RE) with the purpose of enhancing higher energy fragmentation while maintaining low energy processes. The experiments presented serve to illustrate the usefulness of SORI-RE in diverse cases.
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FLUORINATED RASPBERRY-LIKE PARTICLES FOR SUPERAMPHIPHOBIC COATINGSJiang, WEIJIE 21 October 2013 (has links)
Raspberry-like polystyrene particles were fabricated through the covalent linkage of small epoxy-functionalized polystyrene particles (PS-GMA) with large amino-functionalized polystyrene particles (PS-NH2). These covalent bonds yielded more stable and robust particle clusters than would be anticipated from non-covalent interactions. While the structures of these raspberry-like particles provided them with a dual-scale hierarchical roughness and re-entrant sites, they were further functionalized with a fluorinated random copolymer to provide them a low surface tension.
The fluorinated random copolymer used to functionalize these raspberry-like particles was poly(glycidyl methacrylate20%)-co-2(perfluorooctyl)ethyl methacrylate80%)25 or P(GMA20%-co-FOEMA80%)25, where the subscript 25 denotes the total number of the respective GMA and FOEMA units, while the subscript 20% and 80% denote the molar fractions of GMA and FOEMA, respectively. The epoxy groups of the GMA units could react with the amino groups of the raspberry-like particles, thus incorporating the fluorinated polymer onto the surfaces of the raspberry-like particles. In addition, the FOEMA component provided the particles with enhanced amphiphobicity.
Subsequently, these fluorinated raspberry-like particles were cast onto glass slides to demonstrate their superamphiphobic properties. These coatings exhibited superhydrophobic behavior when they were tested against water droplets. Additionally, the oil-repellency of these coatings was tested against various liquids, including diiodomethane, cooking oil, and hexadecane. The coatings exhibited superoleophobic behavior against diiodomethane and cooking oil, as well as highly oleophobic behavior against hexadecane.
This work demonstrates a simple and efficient route for the fabrication of superamphiphobic surfaces. Additionally, these surfaces are among the first examples of coatings prepared via self-assembly techniques that exhibited high repellency against hexadecane. These materials could have potential in various applications that require protection of a surface against wetting by either water or oils. / Thesis (Master, Chemistry) -- Queen's University, 2013-10-18 12:36:39.039
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Re-replication in the Absence of Replication Licensing Mechanisms in Drosophila MelanogasterDing, Queying January 2011 (has links)
<p>To ensure genomic integrity, the genome must be accurately duplicated once and only once per cell division. DNA replication is tightly regulated by replication licensing mechanisms which ensure that origins only initiate replication once per cell cycle. Disruption of replication licensing mechanisms may lead to re-replication and genomic instability. </p><p>DNA licensing involves two steps including the assembly of the pre-replicative compelx at origins in G1 and the activation of pre-RC in S-phase. Cdt1, also known as Double-parked (Dup) in <italic> Drosophila Menalogaster </italic>, is a key regulator of the assembly of pre-RC and its activity is strictly limited to G1 by multiple mechanisms including Cul4<super>Ddb1</super> mediated proteolysis and inhibitory binding by geminin. Previous studies have indicated that when the balance between Cdt1 and geminin is disrupted, re-replication occurs but the genome is only partially re-replicated. The exact sequences that are re-replicated and the mechanisms contributing to partial re-replication are unknown. To address these two questions, I assayed the genomic consequences of deregulating the replication licensing mechanisms by either RNAi depletion of geminin or Dup over-expression in cultured Drosophila Kc167 cells. In agreement with previously reported re-replication studies, I found that not all sequences were sensitive to geminin depletion or Dup over-expression. Microarray analysis and quantitative PCR revealed that heterochromatic sequences were preferentially re-replicated when Dup was deregulated either by geminin depletion or Dup over-expression. The preferential re-activation of heterochromatic replication origins was unexpected because these origins are typically the last sequences to be duplicated during normal S-phase. </p><p>In the case of geminin depletion, immunofluorescence studies indicated that the re-replication of heterochromatin was regulated not at the level of pre-RC activation, but rather due to the restricted formation of the pre-RC to the heterochromatin. Unlike the global assembly of the pre-RC that occurs throughout the genome in G1, in the absence of geminin, limited pre-RC assembly was restricted to the heterochromatin. Elevated cyclin A-CDK activity during S-phase could be one mechanism that prevents pre-RC reassembly at euchromatin when geminin is absent. These results suggest that there are chromatin and cell cycle specific controls that regulate the re-assembly of the pre-RC outside of G1.</p><p>In contrast to the specific re-replication of heterochromatin when geminin is absent, re-replication induced by Dup over-expression is not restricted to heterochromatin but rather includes re-activation of origins throughout the genome, although there is a slight preference for heterochromatin when re-replication is initiated. Surprisingly, Dup over-expression in G2 arrested cells result in a complete endoreduplication. In contrast to the ordered replication of euchromatin and heterochromatin during early and late S-phase respectively, endoreduplication induced by Dup over-expression does not exhibit any temporal order of replication initiation from these two types of chromatin, suggesting replication timing program may be uncoupled from local chromatin environment. Taken together, these findings suggest that the maintenance of proper levels of Dup protein is critical for genome integrity.</p> / Dissertation
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Strategic Forest Management Planning Under Uncertainty Due to FireSavage, David William 23 February 2010 (has links)
Forest managers throughout Canada must contend with natural disturbance processes that vary over both time and space when developing and implementing forest management plans designed to provide a range of economic, ecological, and social values. In this thesis, I develop a stochastic simulation model with an embedded linear programming (LP) model and use it to evaluate strategies for reducing uncertainty due to forest fires. My results showed that frequent re-planning was sufficient to reduce variability in harvest volume when the burn fraction was low, however, as the burn fraction increased above 0.45%, the best strategy to reduce variability in harvest volume was to account for fire explicitly in the planning process using Model III. A risk analysis tool was also developed to demonstrate a method for managers to improve decision making under uncertainty.
The impact of fire on mature and old forest areas was examined and showed that LP forest management planning models reduce the areas of mature and old forest to the minimum required area and fire further reduces the seral area. As the burn fraction increased, the likelihood of the mature and old forest areas satisfying the minimum area requirements decreased. However, if the seral area constraint was strengthened (i.e., the right hand side of the constraint was increased) the likelihood improved. When the planning model was modified to maximize mature and old forest areas, the two fixed harvest volumes (i.e., 2.0 and 8.0 M. m3/decade) had much different impacts on the areas of mature and old forest when the burn fraction was greater than 0.45%.
Bootstrapped burn fraction confidence intervals were used to examine the impact of uncertain burn fraction estimates when using Model III to develop harvest schedules. I found that harvest volume bounds were large when the burn fraction was ≥0.45%. I also examined how the uncertainty in natural burn fraction (i.e., estimates of pre-fire suppression average annual area burned) estimates being used for ecosystem management can impact old forest area requirements and the resulting timber supply.
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