210 research outputs found
Comparison of two harvesting methods for complete tree removal on tree stands on drained peatlands
Productivity of Stump Harvesting for Fuel
The productivity of harvesting stump and root wood was studied in Norway spruce (Picea abies) stands. The objective was to create productivity models (m3/E0h) for stump wood extraction, stump wood forwarding, and site preparation, in addition to identifying work phases and improvement opportunities in the extraction and forwarding chain. Productivity models were based on time studies with professional operators. The independent variables in stump wood extraction were stump diameter (cm) and the number of stumps per hectare. For forwarding, the independent variables were volume of stump wood removed (m3/ha) and forwarding distance (m). When removing 350 stumps per ha with an average diameter of 40 cm, productivity was estimated at 7.9 m3/E0h. Increasing the number of stumps removed from 350 to 800 stumps per ha, increased productivity to 10.8 m3/E0h. Forwarding productivity was 7.8 m3/E0hwithaforwardingdistanceof250mandaload size of 7.0 m3 when removing 60 m3 of stumps per ha
Facilitating joint attention with salient pointing in interactions involving children with autism spectrum disorder
Children with autism spectrum disorder (ASD) reportedly have difficulties in responding to bids for joint attention, notably in following pointing gestures. Previous studies have predominantly built on structured observation measures and predefined coding categories to measure children’s responsiveness to gestures. However, how these gestures are designed and what detailed interactional work they can accomplish have received less attention. In this paper, we use a multimodal approach to conversation analysis (CA) to investigate how educators design their use of pointing in interactions involving school-aged children with ASD or autistic features. The analysis shows that pointing had specific sequential implications for the children beyond mere attention sharing. Occasionally, the co-occurring talk and pointing led to ambiguities when a child was interpreting their interactional connotations, specifically when the pointing gesture lacked salience. The study demonstrates that the CA approach can increase understanding of how to facilitate the establishment of joint attention
Soil-cement bricks produced from local clay brick waste and soft sludge from fiber cement production
Soil-cement bricks were produced using local clay brick waste (CBW) and soft sludge (SS) from fiber-cement industries, preserving raw resources by substituting with industrial wastes. The control formula to produce soil-cement bricks, is 15 wt% Portland cement, 15 wt% sand, and 70 wt% laterite. Clay brick waste was added with values from 10 to 50 % of laterite weight in the control formula. For SS, 5 and 10 % was used to replace the total weight of the dry mixture in the control formula. The samples were shaped by using a manual brick making machine. The results showed that the compressive strength of all by-product bricks exceeded industry standards. The maximum compressive strength was attained for 10 % replacement of laterite by CBW. When using both SS and CBW, thermal conductivity and weight of the bricks were further reduced. However, the percentage of water absorption incorporated into the by-product bricks was higher than that of the control formula but still within permissible limit of the industrial standard for load-bearing applications. All by-product bricks showed lower thermal conductivity compared with the control formula. Soil-cement bricks produced with industry by-products have improved or provided similar properties to control formula soil-cement bricks. The utilization of CBW and SS content in the brick samples can save natural resources, decreasing fuel consumption, and reduce CO2 emissions during delivery
Properties and performance of the basalt-fiber reinforced texture roof tiles
The mechanical and the physical properties, and the performance of texture roof tiles reinforced with the basalt fibers were observed. The samples of the basalt-fiber reinforced texture roof tiles were produced on the industrial scale by using filter pressing method. After forming, the as-molded samples were air cured and characterized based on ASTM C1185 standard for their mechanical properties and physical properties. In addition, the roof-tile installation test was also performed. The results showed that the samples of the basalt-fiber reinforced texture roof tile (BFRT) could be produced on the industrial scale by using the common setting of the forming machine without further adjustment. For the appearance, the samples of BFRT had the appearance alike the common texture-roof tile products. In addition, BFRTs could be cut and drilled by using the standard cutting machine and could be installed by using the standard procedure for texture roof tile installation. For the properties, BFRTs had the properties as required by the industry requirements including the modulus of rupture (MOR) greater than 5 MPa, the modulus of elasticity (MOE) greater than 7000 MPa, the impact resistance greater than 1000 J/m2, and the density between 1.5−2.2 g/cm3
The influence of different crystal modifiers on ultra-low embodied energy curing fiber-reinforced cement composites
Fiber-reinforced cement composites (FRCC) are widely used in the construction of houses and commercial buildings in many countries such as the United States, the United Kingdom, the European countries, and the Asian countries such as China, India, and Thailand. Conventionally, the FRCC is manufactured from Portland cement, silica sand, and cellulose fiber using the so-called autoclaved curing under a designate hydrothermal condition to accelerate the hydration reaction resulting in superior properties. However, the autoclave-curing process needs a huge investment and generates highly environmental impact specially greenhouse gases due to its heavy energy consumption. Hence, this research aims to develop the FRCC with lowering embodied energy via the energy-free moisture curing process. The use of different crystal modifiers (CM) including synthetic tobermorite, aluminosilicate complex, and modified lithium compound in addition of the usual FRCC composition to drive the hydration kinetic and then properties achieved were characterized by the relevance of higher heat of hydration. Moreover, scanning electron microscope (SEM) were used to reveal the favorable effects of appropriate CM through the microstructure. The results approved that the FRCC with qualified mechanical performance and densified microstructure was successfully produced by using the appropriate moisture curing condition and CM. Additionally, using alumino-silicate complex as CM at 3% of cement weight produced FRCC with the highest modulus of elasticity of 9,067 ± 492 MPa, and the lowest % water absorption of 27.42 ± 1.65 %
Two alternatively-spliced human nebulin isoforms with either exon 143 or exon 144 and their developmental regulation
Nebulin is a very large protein required for assembly of the contractile machinery in muscle. Mutations in the nebulin gene NEB are a common cause of nemaline myopathy. Nebulin mRNA is alternatively-spliced so that each mRNA contains either exon 143 or exon 144. We have produced monoclonal antibodies specific for the regions of nebulin encoded by these two exons, enabling analysis of expression of isoforms at the protein level for the first time. All antibodies recognized a protein of the expected size (600-900 kD) and stained cross-striations of sarcomeres in muscle sections. Expression of exon 143 is developmentally-regulated since newly-formed myotubes in cell culture expressed nebulin with exon 144 only; this was confirmed at the mRNA level by qPCR. In fetal muscle, nebulin with exon 143 was expressed in some myotubes by 12-weeks of gestation and strongly-expressed in most myotubes by 17-weeks. In mature human muscle, the exon 144 antibody stained all fibres, but the exon 143 antibody staining varied from very strong in some fibres to almost-undetectable in other fibres. The results show that nebulin containing exon 144 is the default isoform early in myogenesis, while regulated expression of nebulin containing exon 143 occurs at later stages of muscle development.Peer reviewe
Dominantly inherited distal nemaline/cap myopathy caused by a large deletion in the nebulin gene
We report the first family with a dominantly inherited mutation of the nebulin gene (NEB). This 100kb in-frame deletion encompasses NEB exons 14-89, causing distal nemaline/cap myopathy in a three-generation family. It is the largest deletion characterized in NEB hitherto. The mutated allele was shown to be expressed at the mRNA level and furthermore, for the first time, a deletion was shown to cause the production of a smaller mutant nebulin protein. Thus, we suggest that this novel mutant nebulin protein has a dominant-negative effect, explaining the first documented dominant inheritance of nebulin-caused myopathy. The index patient, a young man, was more severely affected than his mother and grandmother. His first symptom was foot drop at the age of three, followed by distal muscle atrophy, slight hypomimia, high-arched palate, and weakness of the neck and elbow flexors, hands, tibialis anterior and toe extensors. Muscle biopsies showed myopathic features with type 1 fibre predominance in the index patient and nemaline bodies and cap-like structures in biopsies from his mother and grandmother. The muscle biopsy findings constitute a further example of nemaline bodies and cap-like structures being part of the same spectrum of pathological changes. (C) 2019 Elsevier B.V. All rights reserved.Peer reviewe
Nebulin nemaline myopathy recapitulated in a compound heterozygous mouse model with both a missense and a nonsense mutation in Neb
Nemaline myopathy (NM) caused by mutations in the gene encoding nebulin (NEB) accounts for at least 50% of all NM cases worldwide, representing a significant disease burden. Most NEB-NM patients have autosomal recessive disease due to a compound heterozygous genotype. Of the few murine models developed for NEB-NM, most are Neb knockout models rather than harbouring Neb mutations. Additionally, some models have a very severe phenotype that limits their application for evaluating disease progression and potential therapies. No existing murine models possess compound heterozygous Neb mutations that reflect the genotype and resulting phenotype present in most patients. We aimed to develop a murine model that more closely matched the underlying genetics of NEB-NM, which could assist elucidation of the pathogenetic mechanisms underlying the disease. Here, we have characterised a mouse strain with compound heterozygous Neb mutations; one missense (p.Tyr2303His), affecting a conserved actin-binding site and one nonsense mutation (p.Tyr935*), introducing a premature stop codon early in the protein. Our studies reveal that this compound heterozygous model, Neb(Y2303H, Y935X), has striking skeletal muscle pathology including nemaline bodies. In vitro whole muscle and single myofibre physiology studies also demonstrate functional perturbations. However, no reduction in lifespan was noted. Therefore, Neb(Y2303H,Y935X) mice recapitulate human NEB-NM and are a much needed addition to the NEB-NM mouse model collection. The moderate phenotype also makes this an appropriate model for studying NEB-NM pathogenesis, and could potentially be suitable for testing therapeutic applications.Peer reviewe
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