Type II muscle fibre properties are not associated with balance recovery following large perturbations during walking in young and older adults

Falls among older adults are often attributed to declining muscle strength with ageing. Associations between muscle strength and balance control have been reported, but the evidence for, and key mechanisms of resistance exercise in fall prevention are unclear. No studies have directly examined the relationship between muscle fibre characteristics and reactive balance control. Here, we address whether or not Type II muscle fibre characteristics associate with reactive balance during walking in young and older adults with varying muscle fibre type composition. We analyse muscle biopsy-derived fibre characteristics and stability during a treadmill-based walking perturbation (trip-like) task of healthy young adults, healthy, normally active older adults, trained older adults and physically impaired older adults. We find no significant associations between Type II muscle fibre properties and reactive balance during walking, indicating that practitioners and researchers should consider more than just the muscle tissue properties when assessing and intervening on fall risk.

Anatomical and chemical characterization of Alstonia boonei for pulp and paper production

Alstonia boonei, an abundant lesser utilized species within the West African Subregion, was evaluated as an alternative raw material for pulp and paper production. The basic density (BD), fibre characteristics [fibre length (FL), fibre diameter (FD), lumen diameter (LD) and wall thickness (WT)], derived anatomical indices [Flexibility Ratio (FR), Slenderness Ratio (SR), Rigidity Coefficient (RC), Luce’s Shape Factor (LSF), Solids Factor (SF) and Runkel Ratio (RR)] and chemical composition (lignin, holocellulose, 1% NaOH solubility and ash contents) of A. boonei were studied to evaluate variation along the trunk (base, middle and top portions) and ascertain its suitability for pulp and paper production. Significant variations were observed in the density and fibre characteristics along the trunk of the tree. Although the FD was large, the observed adequate FL, thin-wall and large LD implied easy beating of fibres and manufacture of dense, smooth and strong papers. The favourable SF, RR, FR, RC, and LSF values obtained for the fibres would produce papers with suitable burst and tearing strengths and folding endurance. Chemically the lower lignin (< 30%), ash and 1% NaOH solubility and the high holocellulose contents of A. boonei, will generate a higher pulp yield. A. boonei although a low-density species, will be desirable for pulp and paper production.

Fibre Characteristics of Huacaya Alpaca in Peru

Background: The fibre characteristics of fleece weight (FW), mean fibre diameter (MFD), coefficient of variation of mean fibre diameter (CVMFD) and common phenotypic correlations between them of Huacaya alpacas (Vicugna pacos) breed, were estimated on 959 one-year-old animals, under extensive rangeland management conditions. Methods: Samples were taken between 2005 and 2018 (male and female), of two coat colors (white and brown), at the Toccra CEDAT-DESCO Alpaca Development Center (Arequipa, Perú). Model were developed an they included year, sex and coat color and their interactions with FW, MDF and CVMDF of alpaca’s fibre under the experimental design was completely randomized with a factorial arrangement of 12×2×2. Result: Statistical significant effect was for year of birth × sex interaction when FW was analyzed while year of birth × color interaction explained MFD and CVMFD variation (p less than .001). Phenotypic correlation calculated by Pearson’s coefficient showed that FW was positively correlated with MFD (0.24) while CVMFD was positively correlated with MFD (0.10). Results from this study indicated that the FW was influenced by both year of birth and sex, while MFD and CVMFD were influenced by both year of birth and color. Overall, it was concluded that a genetic progress can be achieved in the huacaya alpaca breed of CEDAT genetic improvement program.

ASSESSMENT OF FIBRE CHARACTERISTICS OF SPONDIA MOMBIN L. (ANACARDIACEAE) FOR PULP AND PAPER PRODUCTION

The fibre characteristics of five Spondia mombin stands were studied to determine their suitability for pulp and paper production. Wood slivers obtained parallel to grain at three (3) different positions along the bole were macerated in combined identical amounts of glacial acetic acid plus hydrogen peroxide under heat at between 80-100o C. Macerated fibres were washed clean of mixture and mounted on slide for microscopic examination of fibre characteristics. Completely Randomized Design (CRD) was employed for the experiment. Data were analysed using one-way Analysis of Variance (ANOVA) while, the Duncan’s Multiple Range Test (DMRT) was used to separate means of significant differences among the treatments. Results show that significant differences existed in fibre characteristic of sampled trees, however the fibre length ranged from 0.98-1.0 mm, fibre diameter (18.22-21.47 um), lumen width (10.90-12.98 um) and cell wall thickness (3.86-4.60 um). Significant differences were also observed among the derived fibre characteristics, the Runkel ratio ranged from 0.66-8.89, elasticity coefficient (57.22-60.50 %), coefficient of rigidity (19.78-22.24 %), slenderness ratio (43.27-46.5). This implied that, the fibres of S. mombin were short and elastic which make the wood species an appropriate raw material for pulp and paper making especially when blended with other long fibre species.

MORPHOLOGICAL PROPERTIES OF HURA CREPITANS L. (EUPHORBIACEAE) AS PROSPECTIVE RESOURCE FOR PULP AND PAPERMAKING

Hura crepitans L. (Euphorbiaceae) is a tropic tree species that was investigated for pulp and paper characteristics in this study. The diameters of five (5) different stands of Hura crepitans trees were first determined using diameter tape. Wood slivers were obtained from sapwood of the trees parallel to grain and at three (3) different positions along the axis, at the base (5%), middle (50%) and top (90%). The wood slivers were macerated in a mixture of equal volumes of glacial acetic acid and hydrogen peroxide at between 80 -100 degrees Celsius for 2 hours. Macerated fibres were washed and used to prepare microscopic slides where 15 fibres were measured per slide. Data recorded was subjected to One-way Analysis of Variance (ANOVA) based on Completely Randomized Design (CRD). Results show that both the primary fibre characteristics and derived characteristics were significantly different at p<0.05? The mean fibre characteristics ranged as follows, Fibre lengths (0.87-1.16 mm), Fibre diameter (18.84 - 24.44 µm), Lumen width (9.92-16.89 µm) and Cell wall thickness (3.93-4.60 µm). The derived mean fibre characteristics ranged as follows; Runkel ratio (0.36-0.78), Elasticity coefficient (44.20-67.91%), Rigidity coefficient (15.98-27.82 %) and Slenderness ratio (0.44-0.80). This result implies that Hura crepitans has short fibres with high flexibility, which can collapse easily and form a fully bonded paper and is therefore recommended for pulp and paper production

Comparative Studies of the Shear Strength Property of Two Members of the Fabaceae Family with Respect to Their Fibres

Aim: The shear strength of wood is a very significant parameter required in describing the potential of woods in making wooden structure. This study is aimed at comparing the shear strength of Pentaclethra macrophylla and Erythrophleum suaveolens with respect to their fibre. This is to determine the suitability of including Erythrophleum suaveolens in making traditional motars in order to reduce the demand load on Pentaclethra macrophylla. Methods: The heartwood samples of Pentaclethra macrophylla and Erythrophleum suaveolens for maceration were fixed in specimen bottles containing formalin-acetic-alcohol (FAA) in the ratio 90:5:5 to prevent fungal growth. The preparations involved cutting small clear samples of the heartwood of the two timber species of fabaceae family. The shear strength parallel to the grain test was conducted using a Hounsfield Tensometer. Results: Significant differences were recorded across the fibre characteristics of the two plant species. The share strength of the 25 wood samples from the two plants each fluctuate around 100 to 200 N/mm2. On the average, P. macrophylla recorded higher shear strength as compared to suaveolens however no significant difference was recorded between the means when tested for significant differences using independent sample t-test. Conclusion: Since the shear strength of E. suaveolens is comparable to that of P. macrophylla, it is therefore recommended its substitute for the manufacturing of wood based products where P. macrophylla has been in continual usage in order to relieve the pressure and demand on P. macrophylla.

COMPARATIVE ANALYSIS OF THE TENSILE STRENGTH AND BREAKING EXTENSION OF THE SHEEP, GOAT AND SHEEP/GOAT FELT FABRICS

The comparative analysis of the tensile strength and breaking extension of the sheep, goat and sheep/goat blend has been done. This research shows that the sheep felt fabrics has higher tensile strength followed by the sheep/goat felt fabric and lastly by the goat felt fabrics. While the goat felt fabrics has higher breaking extension followed by the sheep/goat felt fabrics and lastly by the sheep felt. This can be attributable to the nature of their felt fabrics which depends on their fibre characteristics. The sheep felt fabric is regarded as a strong fabric and less extensible because of the ease in which the protruding fibre scales interlocks and therefore can withstand more stress. The goat felt fabric has higher breaking extension properties because of the elastic nature of their fibres and as such can be regarded as a tough fabric.

Evaluation of a new portable device that measures diameter of animal fibres

Increasing production of animal fibres has increased the need for a portable instrument that measures fibre diameter and associated characteristics with precision and accuracy. This research evaluated a new portable fibre tester (PFT) by measuring the diameter and related characteristics of tops and scoured fibres of wool, alpaca, and vicuña. The PFT was constructed with integrated mechanical, optical, electronic, and informatic components. Textile tops of sheep wool, alpaca fibres, and mohair goat fibres were used as standard references to calibrate the PFT and determine its accuracy and precision. The results were compared with those from a wool industry standard instrument (OFDA2000) that uses similar technology. The PFT had high accuracy (-0.01, -0.12, and -0.01 μm) for average fibre diameter (AFD) of wool, alpaca, and mohair fibres, respectively. Deviations of standard tops (ST) were within industry-accepted tolerance ranges. Standard errors, indicating precision, were low, ranging from 0.07 to 0.25 μm, 0.02 to 0.44 μm, and 0.09 to 0.024 μm, for wool, alpaca, and mohair fibre tops, respectively. The correlations of measurements of AFD from the two instruments were 0.99 for wool, alpaca, and mohair fibres, but lower for vicuña fibres (0.82). No evidence of bias was observed. Therefore, the PFT may be used as an alternative instrument for measuring fibre diameter and quantifying variation in diameter of wool, mohair, and alpaca fibres. The PFT has appeal for use in the field for practical animal selection and fleece classification based on fibre characteristics. Keywords: alpaca, fibre diameter, mohair, vicuña, wool