Log sawing position optimization using computed tomography scanning

When disjoining a log, several factors affect the value of the sawn timber. There are log features, such as outer shape, knots, rot, and so on. There are also sawing parameters, such as sawing pattern, log position, and so on. If full information about log features is available, sawing parameters can be adapted in order to maximize product value in sawmills. This is soon possible, since computed tomography (CT) scanners for the sawmill industry are being realized. This study aimed at investigating how CT data can be used to choose rotational position, parallel displacement, and skew of sawlogs, to maximize the value of the sawn products. The study was made by sawing simulation of 269 CT scanned logs of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies [L.] H. Karst.). The results showed that value recovery could be improved by 13% in average, compared to a sawing position based on log outer shape, and 21% compared to sawing logs centered and horns down. It can be concluded that a CT scanner, used in a sawline to optimize sawing parameters, has a large potential for increasing value recovery and thus profit.     

Feeding motivation as a personality trait in Nile tilapia (Oreochromis niloticus): role of serotonergic neurotransmission

Consistent individual variation in behaviour and physiology (i.e. animal personality or coping style) has emerged as a central topic in many biological disciplines. Yet, underlying mechanisms of crucial personality traits like feeding behaviour in novel environments remain unclear. Comparative studies, however, reveal a strong degree of evolutionary conservation of neural mechanisms controlling such behaviours throughout the vertebrate lineage. Previous studies have indicated duration of stress-induced anorexia as a consistent individual characteristic in teleost fishes. This study aims to determine to what degree brain 5-hydroxytryptamine (5-HT, serotonin) activity pertains to this aspect of animal personality, as a correlate to feed anticipatory behaviour and recovery of feed intake after transfer to a novel environment. Crucial to the definition of animal personality, a strong degree of individual consistency in different measures of feeding behaviour (feeding latency and feeding score), was demonstrated. Furthermore, low serotonergic activity in the hypothalamus was highly correlated with a personality characterized by high feeding motivation, with feeding motivation represented as an overall measure incorporating several behavioural parameters in a Principle Component Analyses (PCA). This study thus confirms individual variation in brain 5-HT neurotransmission as a correlate to complex behavioural syndromes related to feeding motivation.     

Supply chain management in the Swedish wood products industry – a need analysis

This paper examines the potential of supply chain management (SCM) to address challenges associated with Swedish wood-based supply chains (SCs). Information drawn from a review of literature concerning SCM in the wood products industry is compared and contrasted with data obtained from a case study of an integrated sawmill SC in Northern Sweden, focusing on interviewed participants’ perceived needs and benefits of integrating SC operations. Key components of SCM for the wood products industry are suggested for categorizing the literature and results from the case study. Previous SCM studies have largely focused on solving planning problems by operational analysis, and/or SC strategies, while several important aspects including risk management, integrated performance indicators, power relations, leadership and culture have received relatively little attention. The interviews highlight needs to enhance SC actors’ coordination and communication, as well as for more systematic study of the potential for enhancing efficiency and profit margins in SCs of Swedish wood products.     

Effects of five tree-selection strategies when thinning spruce (Picea abies) stands: a case study in a field trail in southern Sweden

The aim of this study was to show the effects of five tree-selection strategies when thinning on quality and growth properties of Norway spruce stands, and their potential for improving quality in the stands. The five strategies were thinning to retain high-quality (HQ) and low-quality (LQ) trees, thinning from above (A) and below (B) and thinning to obtain an even distribution of residual trees (S). The study was conducted in two planted stands close to rotation age, located in southern Sweden, which had been thinned twice since the establishment of the thinning experiment. In the two quality-based treatments trees were selected for harvest on the basis of the following growth and quality traits: tree class, vitality, dbh, height, straightness, branch diameter and quality defects. The quality traits were found to be largely independent of tree size, thus the selection strategies based solely on dbh (A and B) did not improve quality within the stands. Thinning targeting HQ traits promoted the retention and growth of HQ trees, and improved overall quality of the stands compared to the other treatments. HQ thinning increased the share of straight trees by 15%, on average. Significant proportions of stem crooks and quality defects detected before the first thinning were invisible 21 years after it. All thinned stands had higher proportions of naturally pruned trees than unthinned stands. The selection method had no influence on periodic annual increment after thinning.     

Prediction of nutritive values,morphology and agronomic characteristics in forage maize using two applications of NIRS spectrometry

This study evaluates nutritive, morphological and agronomic characteristics of forage maize predicted by using a high-quality near-infrared (NIR) spectrometer and an NIR hyperspectral-imaging technique using partial least squares (PLS) regression models. The study includes 132 samples of dried milled whole-plant homogenates of forage maize with variation in maturity, representing two growing seasons, three locations in Sweden and three commercial maize hybrids. The samples were measured by a classical sample cup NIR spectrometer and by a pushbroom hyperspectral-imaging instrument. The spectra and a number of variables (crude protein, CP, neutral detergent fibre, starch, water soluble carbohydrates (WSC) and organic matter digestibility), morphological variables (leaves, stems & ears) and crop yield were used to make PLS calibration models. Using PLS modelling allowed the determination of how well maize variables can be predicted from NIR spectra and a comparison of the two types of instruments. Most examined variables could be determined equally well, by both instruments, but the pushbroom technique gave slightly better predictions and had higher analytical capacity. Predictions of CP, starch, WSC and the proportions of ears in the maize gave robust. The findings open new possibilities to further utilise the technology in plant breeding, crop management, modelling and forage evaluation.     

Potential for increasing volume yield by reducing planing allowance

About half the volume of sawlogs ends up as sawn and planed timber. The rest is lost due to drying shrinkage or is turned into by products. As the raw material is a major expense for a sawmill, it is important to reduce waste. To investigate how much the volume yield in the production of sawn and planed timber could be increased by reducing the target dimensions in the sawing stage in a sawmill, two groups of sawn timber were planed under similar conditions. One group consisted of sawn Scots pine timber with a large variation in twist. The other group consisted of sawn Norway spruce timber planed under different pressure settings. Using X-ray images, the minimum dimension for avoiding planer misses was calculated for each board, to find the smallest green target dimension. This was compared to actual measured dimensions. It was found that most sawn timber had unnecessarily large dimensions, and it was also found that a reduction in the target dimensions could increase the volume yield for sawn and planed timber by more than 3 percentage points. Boards with large twist would however need a higher planing allowance. The effect of the planer pressure setting was negligible.     

General expression of RoTat 1.2 variable antigen type in Trypanosoma evansi isolates from different origin

The variable surface glycoprotein of Trypanosoma evansi RoTat 1.2 variable antigen type (VAT) is used as an antigen in different antibody detection assays for T. evansi. To obtain more information on the predominant character of RoTat 1.2 and its diagnostic potential in antibody detection tests, we checked its expression in 10 different T. evansi stocks and clones from different parts of the world. Cryostabilates were injected into mice and the trypanosomes of the first peak parasitaemia were screened for the presence of RoTat 1.2 by VAT specific immunofluorescence. To monitor the appearance of RoTat 1.2 specific antibodies during infection, rabbits were infected and serologically tested at different time intervals with VAT specific immune trypanolysis, CATT/T. evansi, LATEX/T. evansi and ELISA/T. evansi.Test results confirm the predominant character of RoTat 1.2.