Characteristics of Cellulose Nanofibrils from Transgenic Trees with Reduced Expression of Cellulose Synthase Interacting 1

Cellulose nanofibrils can be derived from the native load-bearing cellulose microfibrils in wood. These microfibrils are synthesized by a cellulose synthase enzyme complex that resides in the plasma membrane of developing wood cells. It was previously shown that transgenic hybrid aspen trees with reduced expression of CSI1 have different wood mechanics and cellulose microfibril properties. We hypothesized that these changes in the native cellulose may affect the quality of the corresponding nanofibrils. To test this hypothesis, wood from wild-type and transgenic trees with reduced expression of CSI1 was subjected to oxidative nanofibril isolation. The transgenic wood-extracted nanofibrils exhibited a significantly lower suspension viscosity and estimated surface area than the wild-type nanofibrils. Furthermore, the nanofibril networks manufactured from the transgenics exhibited high stiffness, as well as reduced water uptake, tensile strength, strain-to-break, and degree of polymerization. Presumably, the difference in wood properties caused by the decreased expression of CSI1 resulted in nanofibrils with distinctive qualities. The observed changes in the physicochemical properties suggest that the differences were caused by changes in the apparent nanofibril aspect ratio and surface accessibility. This study demonstrates the possibility of influencing wood-derived nanofibril quality through the genetic engineering of trees

Properties of cellulose nanofibre networks prepared from never-dried and dried paper mill sludge

Paper mills yield large volumes of sludge materials which pose an environmental and economic challenge for disposal, despite the fact that they could be a valuable source for cellulose nanofibres (CNF) production. The aim of the study was to evaluate the production process and properties of CNF prepared by mechanical fibrillation of never-dried and dried paper mill sludge (PMS). Atomic force microscopy (AFM) showed that average diameters for both never-dried and dried paper sludge nanofibres (PSNF) were less than 50 nm. The never-dried and dried sludge nanofibres showed no statistical significant difference (p > 0.05) in strength ∼92 MPa, and ∼85 MPa and modulus ∼11 GPa and ∼10 GPa. The study concludes that paper mill sludge can be used in a dried state for CNF production to reduce transportation and storage challenges posed on industrial scale

Properties of cellulose nanofibre networks prepared from never-dried and dried paper mill sludge

Paper mills yield large volumes of sludge materials which pose an environmental and economic challenge for disposal, despite the fact that they could be a valuable source for cellulose nanofibres (CNF) production. The aim of the study was to evaluate the production process and properties of CNF prepared by mechanical fibrillation of never-dried and dried paper mill sludge (PMS). Atomic force microscopy (AFM) showed that average diameters for both never-dried and dried paper sludge nanofibres (PSNF) were less than 50 nm. The never-dried and dried sludge nanofibres showed no statistical significant difference (p > 0.05) in strength ∼92 MPa, and ∼85 MPa and modulus ∼11 GPa and ∼10 GPa. The study concludes that paper mill sludge can be used in a dried state for CNF production to reduce transportation and storage challenges posed on industrial scale

Analysis of transcript and protein overlap in a human osteosarcoma cell line

<p>Abstract</p> <p>Background</p> <p>An interesting field of research in genomics and proteomics is to compare the overlap between the transcriptome and the proteome. Recently, the tools to analyse gene and protein expression on a whole-genome scale have been improved, including the availability of the new generation sequencing instruments and high-throughput antibody-based methods to analyze the presence and localization of proteins. In this study, we used massive transcriptome sequencing (RNA-seq) to investigate the transcriptome of a human osteosarcoma cell line and compared the expression levels with <it>in situ </it>protein data obtained in-situ from antibody-based immunohistochemistry (IHC) and immunofluorescence microscopy (IF).</p> <p>Results</p> <p>A large-scale analysis based on 2749 genes was performed, corresponding to approximately 13% of the protein coding genes in the human genome. We found the presence of both RNA and proteins to a large fraction of the analyzed genes with 60% of the analyzed human genes detected by all three methods. Only 34 genes (1.2%) were not detected on the transcriptional or protein level with any method. Our data suggest that the majority of the human genes are expressed at detectable transcript or protein levels in this cell line. Since the reliability of antibodies depends on possible cross-reactivity, we compared the RNA and protein data using antibodies with different reliability scores based on various criteria, including Western blot analysis. Gene products detected in all three platforms generally have good antibody validation scores, while those detected only by antibodies, but not by RNA sequencing, generally consist of more low-scoring antibodies.</p> <p>Conclusion</p> <p>This suggests that some antibodies are staining the cells in an unspecific manner, and that assessment of transcript presence by RNA-seq can provide guidance for validation of the corresponding antibodies.</p

How do sand addition, soil moisture and nutrient status influence greenhouse gas fluxes from drained organic soils?

Drainage turns peatlands from natural carbon sinks into hotspots of greenhouse gas (GHG)emissions from soils due to alterations in hydrological and biogeochemical processes. As a consequence of drainage-induced mineralisation and anthropogenic sand addition, large areas of former peatlands under agricultural use have soil organic carbon (SOC)contents at the boundary between mineral and organic soils. Previous research has shown that the variability of GHG emissions increases with anthropogenic disturbance. However, how and whether sand addition affects GHG emissions remains a controversial issue. The aim of this long-term incubation experiment was to assess the influence of hydrological and biogeochemical soil properties on emissions of carbon dioxide (CO 2 ), nitrous oxide (N 2 O)and methane (CH 4 ). Strongly degraded peat with sand addition (peat-sand mixtures)and without sand addition (earthified peat)was systematically compared under different moisture conditions for fen and bog peat. Soil columns originating from both the topsoil and the subsoil of ten different peatlands under grassland use were investigated. Over a period of six months the almost saturated soil columns were drained stepwise via suction to −300 hPa. The CO 2 fluxes were lowest at water-saturated and dry soil moisture conditions, resulting in a parabolic dependence of CO 2 fluxes on the water-filled pore space (WFPS)peaking at 56–92% WFPS. The highest N 2 O fluxes were found at between 73 and 95% WFPS. Maximum CO 2 fluxes were highest from topsoils, ranging from 21 to 77 mg C m −2 h −1 , while the maximum CO 2 fluxes from subsoils ranged from 3 to 14 mg C m −2 h −1 . No systematic influence of peat type or sand addition on GHG emissions was found in topsoils, but CO 2 fluxes from subsoils below peat-sand mixtures were higher than from subsoils below earthified peat. Maximum N 2 O fluxes were highly variable between sites and ranged from 18.5 to 234.9 and from 0.2 to 22.9 μg N m −2 h −1 for topsoils and subsoils, respectively. CH 4 fluxes were negligible even under water-saturated conditions. The highest GHG emissions occurred at a WFPS that relates – under equilibrium conditions – to a water table of 20–60 cm below the surface in the field. High maximum CO 2 and N 2 O fluxes were linked to high densities of plant-available phosphorus and potassium. The results of this study highlight that nutrient status plays a more important role in GHG emissions than peat type or sand addition, and do not support the idea of peat-sand mixtures as a mitigation option for GHG emissions

Från biobaserade restprodukter till nanofibrer genom mekanisk fibrillering för funktionella material

Bio-based resource utilization in different forms has been driven by societal, industrial and academic research interests towards the development of “green”, sustainable materials from renewable sources. Within this context, exploiting biomass from different industrial residues is further advantageous from an environmental and economic point of view, leading to minimization of residues by means of waste treatment and to the development of high-addedvalue- products. Breaking down the cell wall structure to its smallest structural components is one means of turning bio-based residues into high-value products, leaving us with nanofibers. The aim of this work has been to understand how these nanofibers can be liberated from various cellulosic sources using mechanical fibrillation and how they can be assembled into functional hydrogels. The production of bio-based nanofibers as a sustainable bio-based material is in the early stages of commercialization and considerable research has been devoted to explore different methods of reaching nanoscale. However, the extraction process by chemical and/or mechanical means is still associated with a relatively high energy demand and/or cost. These are key obstacles for use of the material in a wide range of applications. Another challenge is that methods to characterize nanofiber dimensions are still being developed, with few options available as online measurements for assessing the degree of fibrillation. Allowing for assessment during the fibrillation process would enable not only optimization towards a more energy efficient fibrillation, but also matching of the nanofiber quality to its intended function, since different applications will require widely different nanofiber qualities. Energy-efficient fibrillation and scalability from industrial residues were explored using upscalable ultrafine grinding processes. Nanofibers from various industrial bio-residues and wood were prepared and characterized, including the development of a method for evaluation of the fibrillation process online via viscosity measurements as an indication of the degree of fibrillation down to nanoscale. Furthermore, the correlation of viscosity to that of the strength of the nanopapers (dried fiber networks) was evaluated for the different raw materials. Switchable ionic liquids (SIL) were tested as a green pretreatment for delignification, without bleaching of wood prior to fibrillation, with the aim to preserve the low environmental impact that the raw material source offers. In order to employ the hydrophilic nature and strong network formation ability of the fibrillated nanofibers, they were utilized in the preparation of functional biomaterials in the form of hydrogels. Firstly, brewer’s spent grain nanofibers were used to promote and reinforce hydrogel formation of lignin-containing arabinoxylan, resulting in a hydrogel completely derived from barley residues. In addition, alginate-rich seaweed nanofibers from the stipe (stem-like part of the seaweed) were used directly after fibrillation as an ink and hydrogels were formed via 3D printing

To teach about sustainable development : Primary school teachers' conceptual understandning and interpretations of teaching about sustainable development

Ett av skolans uppdrag är att belysa om olika samhällsfunktioner och hur vårt sätt att leva på kan anpassas för att skapa hållbar utveckling. All undervisning ska enligt skolans styrdokument genomsyra ett övergripande miljöperspektiv, där eleverna ska ges möjlighet att utveckla kunskaper om hur de själva kan vara med och påverka och ta ansvar för den miljö de vistas i. Tidigare forskning om hållbar utveckling i skolans undervisning riktar främst in sig mot elever i de högre skolåren och barn i förskolan, men inte lika mycket till lärare och elever på lågstadiet. Syftet med denna studie är att bidra till en ökad förståelse av hur lågstadielärare tolkar begreppet hållbar utveckling, hur det kommer till uttryck i deras undervisning och även vilka förmågor de önskar att eleverna utvecklar. För att undersöka detta har jag intervjuat sex lågstadielärare. Svaren har sedan analyserats och jämförts med olika lärandeteorier och tidigare forskning kring området hållbar utveckling.  Resultatet visar att lärarnas uppfattningar om begreppet hållbar utveckling i första hand handlar om ekologiska aspekter, om vårt klimat och vår natur samt hur vi på bästa sätt kan ta hand om den. Vidare går det att identifiera att deras undervisning innehåller en blandning av flera lärandeteorier men att det är övervägande normativa och pluralistiska förhållningsätt som dominerar. Dessutom upplever lärarna att läroplanens uppdrag kring området hållbar utveckling lämnar utrymme för fria tolkningar samt att det är svårt att anpassa undervisningens innehåll till en nivå som passar elever på lågstadiet. Lärarna önskar också att eleverna utvecklar färdigheter som hjälper dem att ta miljövänliga beslut. Beslut som gynnar ett hållbart samhälle

To teach about sustainable development : Primary school teachers' conceptual understandning and interpretations of teaching about sustainable development

Ett av skolans uppdrag är att belysa om olika samhällsfunktioner och hur vårt sätt att leva på kan anpassas för att skapa hållbar utveckling. All undervisning ska enligt skolans styrdokument genomsyra ett övergripande miljöperspektiv, där eleverna ska ges möjlighet att utveckla kunskaper om hur de själva kan vara med och påverka och ta ansvar för den miljö de vistas i. Tidigare forskning om hållbar utveckling i skolans undervisning riktar främst in sig mot elever i de högre skolåren och barn i förskolan, men inte lika mycket till lärare och elever på lågstadiet. Syftet med denna studie är att bidra till en ökad förståelse av hur lågstadielärare tolkar begreppet hållbar utveckling, hur det kommer till uttryck i deras undervisning och även vilka förmågor de önskar att eleverna utvecklar. För att undersöka detta har jag intervjuat sex lågstadielärare. Svaren har sedan analyserats och jämförts med olika lärandeteorier och tidigare forskning kring området hållbar utveckling.  Resultatet visar att lärarnas uppfattningar om begreppet hållbar utveckling i första hand handlar om ekologiska aspekter, om vårt klimat och vår natur samt hur vi på bästa sätt kan ta hand om den. Vidare går det att identifiera att deras undervisning innehåller en blandning av flera lärandeteorier men att det är övervägande normativa och pluralistiska förhållningsätt som dominerar. Dessutom upplever lärarna att läroplanens uppdrag kring området hållbar utveckling lämnar utrymme för fria tolkningar samt att det är svårt att anpassa undervisningens innehåll till en nivå som passar elever på lågstadiet. Lärarna önskar också att eleverna utvecklar färdigheter som hjälper dem att ta miljövänliga beslut. Beslut som gynnar ett hållbart samhälle