306 research outputs found
Trends in markets for forest-based products and consequences for selected countries
The forest sectors in many regions and countries are facing a need to change their structure, due to the development of new markets, emergence of new competitors, and shifts in production and consumption patterns for forest products. This article focuses on recent changes in the trade in these products, on imports and exports of four countries (USA, Sweden, Ukraine and, to a lesser extent, China) during the period from 1995 to 2011. For this purpose we use explanatory data analysis, time series analysis, benchmarking, meta-synthesis and content analysis of scientific and business publications concerning national and global trends in forest product industries. Data sources are various organizations’ databases of international trade in forest-based products in both monetary and physical terms (cubic meters and tons). The results show that the US and Swedish forest sectors are adversely affected by downturns in both their domestic and foreign markets during the study period, while the Ukrainian sector maintains exports of low value-added products at roughly constant levels (except that particle-board exports increase). China maintains production quantities of low value-added forest-based products, but also substantially increases exports of high-value added products. The results may facilitate efforts to forecast future trends and provide useful information and methodological approaches for future studies of interest to industry representatives, policy-makers and researchers
Factors Affecting Swedish Forest Property Prices
Historically the price of a forest estate has, at least in Sweden, been closely related to the financial return from the estate, but this connection no longer seems to be that strong, other factors that previously had limited influence on prices now add to the price. Factors like site productivity and age distribution affect the financial return of a forest estate but is it obvious that these factors still influence prices as they once did? Over the last 20 years, the price of forest estates has increased dramatically. If development of prices has led to a weakened connection between return and price, could this be explained by the fact that previously price affecting factors have less weight when valuing forest estates? The purpose of the study was therefore to investigate how a number of factors influence the forest estate price; including site productivity and age distribution. The results shows that neither site productivity, nor age distribution have a significant impact on the forest estate price. What mainly influence the prices seems to be the standing forest volume on the estate and region. The development of the prices seems not only to have influenced the relationship between the return from the forest and the prices, but also minimized the influence of factors like age distribution and site productivity. This means that estates that are bought within the same region, at the same price per cubic meter, can have considerably different potential to gain financial return
The Republik of South Africa´s forest sector
The South African consumption of paper and paperboard in 2006 was about 2.5 million tons. The total production was 2.9 million tons. (Sweden’s was 12 million tons.) Production of “Other paper and paperboard” was domi-nating (1.8 million tons), other than “Printing and writing paper” and “Newsprint”. The total export of paper and paperboard was almost 1 million tons. (Export of paper and paperboard from Sweden was 10.8 million tons.) The South African consumption of sawn wood was about 2.5 million m3. The total production was about 2.1 million m3. (Sweden’s was about 17.8 million m3.) Total export was almost 1 million m3. (The Swedish’ was 13.2 million m3.) The forest resources consist of three main types: Plantations, indigenous/natural forests and woodlands/savannas. Plantations cover almost 1.3 million ha of South Africa and are one of the largest planted forests in the world. Indigenous forests cover approximately 0.5 million ha. Savannas contribute the bulk of the wooded land area. Depending on how woodlands are classified the area ranges between 29 and 46 million ha. The round wood production was about 30 million m3 solid volume excl. bark, compared with Sweden’s 62 million m3. About one third of this volume is coming from plantations. The industrial use is about 60% (18 million m3) for South Africa and 90% (56 million m3) for Sweden. The rest is used as fuel wood and charcoal. The conifer share of the industrial wood is for South Africa 30% and for Sweden 95%. One advantage for the forest products industry is the well-managed plantations with quickly maturing trees. However, there is a limit for how much land that is suitable for plantations. Another restriction regarding plantation is water supply. The land restitution causes uncertainty about the short term availability of round wood. Thus, supply of wood raw material put an upper limit for the industry’s possibility to expand. Another restriction is electricity supply. Further more, there is a shortage of skilled workers. The sawmilling industry does not show the success story of the pulp and paper industry. Of course the development of the country itself is most important for the development of the forest secto
What is the impact on fish recruitment of anthropogenic physical and structural habitat change in shallow nearshore areas in temperate systems? A systematic review protocol
Shallow nearshore marine ecosystems are changing at an increasing rate due to a range of human activities such as urbanisation and commercial development. The growing numbers of constructions and other physical and structural alterations of the shoreline often take place in nursery and spawning habitats of many fish and other aquatic species. Several coastal fish populations have seen marked declines in abundance and diversity during the past two decades. A systematic review on the topic would clarify if anthropogenic physical and structural changes of near-shore areas have effects on fish recruitment and which these effects are. Methods: The review will examine how various physical and structural anthropogenic changes of nearshore fish habitats affect fish recruitment. Relevant studies include small- and large-scale field studies in marine and brackish systems or large lakes in temperate regions of the Northern and Southern hemispheres. Relevant studies may be based on comparisons between undisturbed and disturbed areas, before and after disturbance, or both. Relevant outcomes include measures of recruitment defined as abundance of juveniles of nearshore fish communities. Searches will be made for peer-reviewed and grey literature in English, Dutch, Danish, Finnish, German, Swedish and Spanish. All fish species and species groups will be considered in this review. Included relevant studies will be subject to a critical appraisal that will assess study validity. From relevant included studies, we will extract information on study characteristics, measured outcomes, exposure, comparators, effect modifiers and critical appraisal. Data synthesis will contain narrative and summary findings of each included study of sufficient quality. Meta-analysis may be possible in cases where studies report similar types of outcome
Valproic Acid Teratogenicity: A Toxicogenomics Approach
Embryonic development is a highly coordinated set of processes that depend on hierarchies of signaling and gene regulatory networks, and the disruption of such networks may underlie many cases of chemically induced birth defects. The antiepileptic drug valproic acid (VPA) is a potent inducer of neural tube defects (NTDs) in human and mouse embryos. As with many other developmental toxicants however, the mechanism of VPA teratogenicity is unknown. Using microarray analysis, we compared the global gene expression responses to VPA in mouse embryos during the critical stages of teratogen action in vivo with those in cultured P19 embryocarcinoma cells in vitro. Among the identified VPA-responsive genes, some have been associated previously with NTDs or VPA effects [vinculin, metallothioneins 1 and 2 (Mt1, Mt2), keratin 1-18 (Krt1-18)], whereas others provide novel putative VPA targets, some of which are associated with processes relevant to neural tube formation and closure [transgelin 2 (Tagln2), thyroid hormone receptor interacting protein 6, galectin-1 (Lgals1), inhibitor of DNA binding 1 (Idb1), fatty acid synthase (Fasn), annexins A5 and A11 (Anxa5, Anxa11)], or with VPA effects or known molecular actions of VPA (Lgals1, Mt1, Mt2, Id1, Fasn, Anxa5, Anxa11, Krt1-18). A subset of genes with a transcriptional response to VPA that is similar in embryos and the cell model can be evaluated as potential biomarkers for VPA-induced teratogenicity that could be exploited directly in P19 cell–based in vitro assays. As several of the identified genes may be activated or repressed through a pathway of histone deacetylase (HDAC) inhibition and specificity protein 1 activation, our data support a role of HDAC as an important molecular target of VPA action in vivo
Selecting "Significant" Differentially Expressed Genes from the Combined Perspective of the Null and the Alternative
Comparison of clustering tools in R for medium-sized 10x Genomics single-cell RNA-sequencing data [version 1; referees: 1 approved, 2 approved with reservations]
Background: The commercially available 10x Genomics protocol to generate droplet-based single-cell RNA-seq (scRNA-seq) data is enjoying growing popularity among researchers. Fundamental to the analysis of such scRNA-seq data is the ability to cluster similar or same cells into non-overlapping groups. Many competing methods have been proposed for this task, but there is currently little guidance with regards to which method to use. Methods: Here we use one gold standard 10x Genomics dataset, generated from the mixture of three cell lines, as well as three silver standard 10x Genomics datasets generated from peripheral blood mononuclear cells to examine not only the accuracy but also robustness of a dozen methods. Results: We found that some methods, including Seurat and Cell Ranger, outperform other methods, although performance seems to be dependent on the complexity of the studied system. Furthermore, we found that solutions produced by different methods have little in common with each other. Conclusions: In light of this, we conclude that the choice of clustering tool crucially determines interpretation of scRNA-seq data generated by 10x Genomics. Hence practitioners and consumers should remain vigilant about the outcome of 10x Genomics scRNA-seq analysis
Differential expression analysis for sequence count data
*Motivation:* High-throughput nucleotide sequencing provides quantitative readouts in assays for RNA expression (RNA-Seq), protein-DNA binding (ChIP-Seq) or cell counting (barcode sequencing). Statistical inference of differential signal in such data requires estimation of their variability throughout the dynamic range. When the number of replicates is small, error modelling is needed to achieve statistical power.

*Results:* We propose an error model that uses the negative binomial distribution, with variance and mean linked by local regression, to model the null distribution of the count data. The method controls type-I error and provides good detection power. 

*Availability:* A free open-source R software package, _DESeq_, is available from the Bioconductor project and from "http://www-huber.embl.de/users/anders/DESeq":http://www-huber.embl.de/users/anders/DESeq
Intra- and inter-individual genetic differences in gene expression
Genetic variation is known to influence the amount of mRNA produced by a gene. Given that the molecular machines control mRNA levels of multiple genes, we expect genetic variation in the components of these machines would influence multiple genes in a similar fashion. In this study we show that this assumption is correct by using correlation of mRNA levels measured independently in the brain, kidney or liver of multiple, genetically typed, mice strains to detect shared genetic influences. These correlating groups of genes (CGG) have collective properties that account for 40-90% of the variability of their constituent genes and in some cases, but not all, contain genes encoding functionally related proteins. Critically, we show that the genetic influences are essentially tissue specific and consequently the same genetic variations in the one animal may up-regulate a CGG in one tissue but down-regulate the same CGG in a second tissue. We further show similarly paradoxical behaviour of CGGs within the same tissues of different individuals. The implication of this study is that this class of genetic variation can result in complex inter- and intra-individual and tissue differences and that this will create substantial challenges to the investigation of phenotypic outcomes, particularly in humans where multiple tissues are not readily available.


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