Higher Proportion Of Fibres Research Articles

Microplastics pollution in sediments of the Thames and Medway estuaries, UK: Organic matter associations and predominance of polyethylene

Microplastics at 10 sites along a 77 km transect of the river Thames estuary (UK) and 5 sites along 29 km of the Medway estuary were separated from sediment and analysed by ATR-FTIR spectroscopy. Microplastics were observed at all sites. Highest Thames concentrations were in urban London between Chelsea and West Thurrock (average 170.80 particles kg−1 ± 46.64, 3.36 mg kg−1 ± 1.79 by mass), mid-outer estuary sites were two to three times lower. Microplastics were slightly dominated by particles (54 %) over fibres (45 %), including polymer types ranked: polyethylene > PET > polypropylene > polyamide. Medway microplastics decreased seaward, with one urban-municipal site impacted by a combined-sewer-overflow containing a high proportion of fibres (Rochester, 484 particles kg−1, 7.39 mg kg−1 by mass). Microplastic abundance was correlated to organic carbon (TOC %) (R2 of 0.71 Thames and 0.96 Medway), but not sediment particle size. Sedimentary microplastics accumulation in the Thames was controlled by urbanisation-distance, and site hydrodynamics.

Keragaman Sifat Anatomi Kayu Sengon dan Kemungkinan Penggunaannya sebagai Bahan Furniture

The development of modern industries has demanded ever-increasing usage requirements for wood products. The use of wood will be more effective and efficient if the properties of wood are known beforehand. This study aims to determine the anatomical diversity of sengon wood and its possible use as a raw material for furniture. This study used a randomized block design with Tukey's follow-up test. The factor used consisted of the radial direction of wood (wood near the skin and wood near the heart). Parameters observed were the proportion of fiber cells (%), the proportion of vessel cells (%), the proportion of parenchyma cells (%), and the proportion of radius cells (%). The results showed that the wood near the skin and near the heart of sengon had variations in the proportion of fiber cells, the proportion of vessel cells, the proportion of parenchyma cells and the proportion of radius cells. The average value of the anatomical diversity of sengon wood in the radial direction is the proportion of fiber cells 49.02 - 50.24 %, the proportion of vessel cells 23.22 - 24.23 %, the proportion of parenchyma cells 13.47 - 14.57 %, the proportion of finger cells finger 11.53 - 13.39 % and . Sengon wood can be used as furniture material for light buildings or for artificial boards because it has a high proportion of fibers.

Characterization and genetic diagnosis of centronuclear myopathies in seven Chinese patients.

Centronuclear myopathies (CNMs) are a group of clinically and genetically heterogeneous muscle disorders. Here, we report a cohort of seven CNM patients with their clinical, histological, and morphological features. In addition, using the next-generation sequencing (NGS) technique (5/7 patients), we identified small indels: intronic, exonic, and missense mutations in MTM1, DNM2, and RYR1 genes. Further genetic studies revealed skewed X-chromosome inactivation in two female patients carrying MTM1 mutations. Based on the results of genetic analysis, these seven patients were classified as (1) X-linked recessive myotubular myopathy (patients 1-3) with MTM1 mutations and mild phenotype, (2) the autosomal dominant CNM (patients 4-6) with DNM2 mutations, and (3) the autosomal recessive CNM (patient 7) with RYR1 mutations. In all patients, histological findings featured a high proportion of fibers with central nuclei. Radial arrangement of the sarcoplasmic strands was observed in DNM2-CNM and RYR1-CNM patients. Muscle magnetic resonance imaging (MRI) revealed a proximal pattern of involvement presented in both MTM1-CNM and RYR1-CNM patients. A distal pattern of involvement was present in DNM2-CNM patients. Our findings thereby identified a number of novel features that expand the reported clinicopathological phenotype of CNMs in China.

The Effects of Laminate Orientation in Resin Infused Kenaf Fibre Reinforced Epoxy Composite

Water retted kenaf fibre reinforced epoxy laminates with five distinct fibre orientations, unidirectional, [+30/0/-30], [+45/0/-45], [+60/0/-60] and [90/] s were produced through resin infusion technique. The fibre weight fraction in each laminate was controlled and the effects of varying orientation in the resulting composite lamina were characterized through tensile and impact properties of the specimens. Superior tensile strength and modulus were observed for the unidirectional lamina while the orthogonal lamina [90/] s depicted the greatest resistance to impact. Specimen with higher proportion of fibres aligned parallel to the loading direction show greater enhancement in tensile strength while impact property of the lamina was found to be greater with increases in fibre orientation perpendicular to the direction of impact load.

Age trends in the wood anatomy of Quercus faginea

The wood anatomy of Quercus faginea, an oak native to the Iberian Peninsula and the Maghreb in Africa, is described and age trends of fibres and ray dimensions are recorded. The analysis was made on a total of 20 trees from two different sites in Portugal. The wood structure within both sites was similar. Quercus faginea shares its microscopic characteristics with other species of the white oak group; i.e., it was not easily distinguishable from other European oaks. The wood is ring porous with wide multiseriate rays and a high proportion of fibres and vasicentric tracheids. There was an increase of fibre and ray dimensions from the pith outwards. Fibre length started to stabilize around 30 years of age up to 50–60 years and decreased afterwards under a traditional rotation period (100–150 years). Linear and polynomial adjustments fitted better the fibre variation at younger and older ages, respectively. Rays were quite homogeneous within the trees. Cambial age accounted less to total variation than individual trees at both sites; i.e., tree-to-tree variation is greater than variation related to maturation or cambial age. The average dimensions of fibres and rays were similar between sites.

An Expanded Finite Element Model of the Intestinal Mixing of Digesta

We used a finite element model to simulate flow through the intestine induced by peristalsis and segmentation. These models explored the effects of varying the rheological properties of digesta, incorporating a slip effect at the wall and the presence of an area of lumen distension adjacent to the area of vorticeal mixing that developed during peristalsis. Reynolds numbers were consistently low (<200) throughout all simulations indicating that local conditions were insufficient to bring about turbulence. When the viscosity of the material flowing through a simple tube model was increased, the area of the vortex orad (upstream) to the zone of peristaltic coaptation was relatively reduced, whilst that aborad (downstream) to the zone of peristalsis was increased. This effect was reduced when the material in the lumen had shear thinning properties. When a region of relative distension of the lumen that travelled aborad to the zone of peristalsis was incorporated into the model, the total area of vortex formation was reduced when material of either high or low Newtonian viscosity was in the lumen. However, these reductions were small compared with those obtained when slip at the intestine wall was incorporated into the model. Incorporation of slip resulted in a marked reduction of both orad and aborad vortices, an effect that persisted when the other effects were incorporated into the same model. The authors conclude that the translocation of nutrients from the intestinal lumen to the wall by action of short-lived vortices will be significantly reduced when the apparent viscosity of digesta is high and there is significant slip at the wall, even when digesta is a shear thinning, non-Newtonian fluid. Hence, the consumption of a diet that contains a high proportion of fibre or other insoluble residue will physically impair absorption by reducing vorticeal flow and promoting creep flow.

Habitat Use and Diet of Baird's Tapirs (Tapirus bairdii) in a Montane Cloud Forest of the Cordillera de Talamanca, Costa Rica1

Results from 24 transects showed that tapirs were less abundant in areas with higher human presence. They also preferred less steep areas, especially as browsing sites. An analysis of feces showed that fibers were the largest component (40–55%) followed by leaves (10–30%) and twigs (15%). Bamboo (Chusquea spp.) was found in all samples and probably accounts for the high proportion of fibers. Twenty-seven plant species were identified to be eaten by tapirs.

Anatomical Characteristics Affecting the Musical Performance of Clarinet Reeds Made fromArundo donaxL. (Gramineae)

The musical performance of clarinet reeds made fromArundo donaxstems was assessed by two experienced clarinettists, and the anatomy of the reeds was studied using confocal laser scanning microscopy to determine the relationship between anatomical characteristics and musical performance. Statistically significant differences between musically good and poor reeds were found in the anatomy of the cortical vascular bundles. Good musical performance was associated with reeds with a high proportion of vascular bundles with continuous fibre rings, and bundles with a high proportion of fibre and a low proportion of xylem and phloem. Significant differences in these anatomical characteristics were also found between reeds originating from cultivated plantation plants when compared to reeds produced from agricultural windbreak plants.

Asbestiform Minerals: Worker Exposure and Risk Assessment in Some Contaminated Australian Mines

Abstract Commercial forms of asbestos are no longer mined in Australia; however, the presence of widespread contaminate asbestiform minerals has recently emerged as an occupational health issue in various mining areas. Strict laws exist nationally in regard to asbestos control, including a prohibition on the use of crocidolite and amosite, and in some states this is extended to cover other amphibole types such as tremo-lite and anthophyllite. A study has commenced in collaboration with mining authorities, mine operators, and the workforce to cover the nickel-and gold-mining areas of Western Australia, an iron ore (taconite) mine in Tasmania, and mine and highway construction sites located in a serpentine belt in New South Wales. Exposure to regulatory fibers is generally below the occupational exposure standard (1 f/mL chrysotile, 0.1 f/mL amphibole), with a high proportion of fibers below the practical detection limit of the monitoring method (<0.05 f/mL), although elevated exposures occur in high-dust o...

Level of wheat bran and saturation of lipid on fibre digestibility in the pig

The recent renewed interest in the feeding of fibrous feedstuffs to pigs has been precipitated by a number of economic and welfare issues. To reduce the costs of pig meat production, farmers have increased the use of cheaper ingredients which tend to contain a high proportion of fibre. The feeding of finely ground cereals in intensive systems has been linked with high rates of mortality resultant from gastric lesions. Adding materials rich in fibre can be beneficial in this respect through its effects on the gut environment.The addition of fibrous feeds to a diet will however have the effect of diluting the energy concentration of the diet and it is likely that counterbalancing levels of high energy materials will need to be added in order to maintain energy levels.Fibre digestion in the ruminant is known to be depressed by the addition of lipid to a diet and it may be that fermentation in the hind gut of the pig is similarly affected. Tallow, a saturated fat, and maize oil, an unsaturated oil, were used to investigate the effect of saturation of lipid on the digestibility of fibre from wheat bran. The effect of level of wheat bran on fibre digestibility was also examined.

Conduction abnormalities are restricted to the central nervous system in experimental autoimmune encephalomyelitis induced by inoculation with proteolipid protein but not with myelin basic protein.

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory demyelinating disease of the central nervous system (CNS) and can be induced by inoculation of animals with homogenized CNS tissue or highly purified myelin proteins such as myelin basic protein (MBP) or proteolipid protein (PLP). It is widely studied as a possible animal model of multiple sclerosis. We performed the present neurophysiological study to define the location of nerve conduction abnormalities in EAE induced by immunization with PLP (PLP-EAE) and in EAE induced by immunization with MBP (MBP-EAE) in the Lewis rat. In rats with tail weakness due to acute PLP-EAE, conduction was normal in the spinal nerve roots and peripheral nerves but there was evidence of conduction block in a high proportion of the fibres in the dorsal columns of the lumbosacral spinal cord. In contrast, in acute MBP-EAE, there was conduction block in a high proportion of fibres in the sacral dorsal and ventral roots of the peripheral nervous system (PNS) and in the dorsal columns of the lumbosacral spinal cord. The distribution of nerve conduction abnormalities is consistent with previous histological studies showing that inflammation and primary demyelination are restricted to the CNS in PLP-EAE, but are present in the CNS and in the spinal roots of the PNS in MBP-EAE. The restriction of functional abnormalities to the CNS in PLP-EAE but not in MBP-EAE may have implications for the human inflammatory demyelinating diseases, including multiple sclerosis.

Bark Structure and Preferential Bark Utilisation by the African Elephant

Bark fracture properties are thought to influence the debarking of selected trees by the African elephant. This hypo thesis was tested for large riverine tree species in the Northern Tuli Game Reserve, Botswana. An index of bark breakage strength and pliability of secondary phloem tissue was compiled for 11 common riverine species, and the bark anatomy of these species was investigated to determine relative fibrosity. The majority of species preferred by elephants have strong and pliable barks, associated with a high proportion of fibres. However, not all preferred species have these characteristics, which indicates that factors other than bark fracture properties affect species preference. Bark structure influences the way pieces of bark are stripped from a tree trunk during debarking. It is hoped that this paper will stimulate further studies on the effects of bark structure on the preferential feeding behaviour of the African elephant.

Caecal function provides the energy of fermentation without liberating heat in the poikilothermic mammal, Heterocephalus glaber

This paper presents the first report of a mammalian internal organ with a lower temperature than its abdominal surrounds. Heterocephalus glaber, the naked mole-rat, is a poikilothermic mammal that leads a strictly subterranean existence and consumes a high proportion of fibre in its diet. The fermentation chamber in these animals appears to absorb rather than generate heat and the temperature in it was consistently 1.2 +/- 0.5 degrees C (n = 17) lower than rectal temperature. A caecum with a lower temperature than its abdominal surrounds provides an internal heat sink which could be advantageous for metabolic heat dissipation in the plugged humid burrows in which the naked mole-rat permanently resides.

Uncompacted lamellae as a feature of tomaculous neuropathy

Clinical findings suggested an inherited tendency to pressure palsies, but in this case without a family history. This was confirmed pathologically by the identification of a tomaculous neuropathy showing some atypical features including the presence of uncompacted lamellae in a high proportion of fibres.

Myosin heavy chain composition of single fibres from m. biceps brachii of male body builders

The myosin heavy chain (MHC) composition of single fibres from m. biceps brachii of young sedentary men (28 +/- 0.4 years, mean +/- SE, n = 4) and male body builders (25 +/- 2.0 years, n = 4) was analysed with a sensitive one-dimensional electrophoretic technique. Compared with sedentary men, the body builders had a higher proportion of fibres containing only MHC type IIa (36 +/- 4 vs 12 +/- 2%; P less than 0.05), but a lower proportion of fibres with a coexistence of MHC types IIa and IIb (16 +/- 3 vs 34 +/- 2%; P less than 0.05) and nearly no fibres containing only MHC type IIb (1 +/- 1 vs 12 +/- 1%; P less than 0.05). Myofibrillar ATPase histochemistry only demonstrated a trend towards a higher proportion of type IIa fibres (31 +/- 6 vs 25 +/- 6%) and a lower proportion of type IIb fibres (18 +/- 5 vs 26 +/- 6%) within the body builders. These results, therefore, suggest an altered expression of MHC isoforms within histochemical type II fibres of human skeletal muscle with body building. Furthermore, in human skeletal muscle differences in expression of MHC isoforms may not always be reflected in the traditional histochemical classification of types I, IIa, IIb and IIc fibres.

Ageing alters the myosin heavy chain composition of single fibres from human skeletal muscle

The myosin heavy chain composition of single fibres (n = 1088) was analysed with an electrophoretic technique in biopsy material from m. vastus lateralis (n = 5) and m. biceps brachii (n = 4) of young (23-31 years old) and elderly men (68-70 years old). In m. vastus lateralis, elderly subjects had a higher proportion of fibres showing a coexistence of myosin heavy chain types I and IIa (20 +/- 3% vs 8 +/- 1%, P less than 0.05) and of myosin heavy chain types IIa and IIb (33 +/- 2% vs 12 +/- 4%, P less than 0.05). In contrast, the young subjects had a higher proportion of fibres containing only myosin heavy chain type I (50 +/- 5% vs 33 +/- %, P less than 0.05) and type IIa (26 +/- 3% vs 12 +/- 2%, P less than 0.05). A similar pattern of myosin heavy chain expression was found in single fibres from m. biceps brachii, with the exception that the elderly subjects had a lower proportion of fibres with coexistence of types IIa and IIb (23 +/- 1% vs 34 +/- 2%, P less than 0.05) and a higher proportion of fibres containing only myosin heavy chain type IIa (25 +/- 5% vs 12 +/- 2%, P less than 0.05). Three fibres from m. biceps brachii contained all three isoforms. These results indicate that coexistence of myosin heavy chain isoforms in single fibres is present in skeletal muscles of young adults, and that there is an increased occurrence of this phenomenon with ageing.(ABSTRACT TRUNCATED AT 250 WORDS)

Leverage and muscle type in crab chelae (Crustacea: Brachyura)

The chelae of Cancer pagurus and Macropipus depurator were examined with respect to mechanical advantage. The closer muscles were investigated with respect to sarcomere length in the constituent fibres and to the force developed by the whole muscle during isometric contraction. Cancer chelae have a relatively high mechanical advantage, 0.329 ± 001. Cancer closer muscles contain a high proportion of fibres with long sarcomeres, mean lengths mostly falling between 12 and 15 μm, and develop a maximum stress of about 496 kN.m−2 during contraction. These figures are typical for “slow” crustacean muscle. The chelae of M. depurator are dimorphic. In one, the strong chela, the mechanical advantage is 0.248 ± 0.066 while in the other, the fast chela, the mechanical advantage is 0.177 ± 0.006. M. depurator closer muscles contain fibres with mean sarcomere lengths mostly falling between 6 and 10 μm. The muscle develops a maximum stress of about 145 kN.m−2 during contraction. These figures are typical of “intermediate” crustacean muscles. “Fast” muscle fibres with short sarcomeres (about 30 um) were found in the chelae of both Cancer and M. depurator but were much commoner in the latter. Thus in Cancer a high mechanical advantage is correlated with slow muscle while in M. depurator lower mechanical advantages are broadly correlated with faster muscle. Consistent correlation between mechanical advantage and muscle type in the dimorphic chelae of M. depurator, however, is lacking. No consistent regionation of fibres with similar properties was found in the muscles.

Studies in the behaviour of dairy cows at pasture

The behaviour of grazing dairy cows was studied under commercial conditions in a series of ten observations covering two grazing seasons. In all cases one Ayrshire cow in milk was under observation for a period of 24 hours commencing at 2.30 p.m. and the times of milking were 6.00 a.m. and 3.00 p.m.o(1)The average time spent grazing was 7 hours and approximately 61/4 hours were spent chewing cud.(2)The average figures indicated that 42% of the grazing time took place during the “day” inter-milking period and 58% during the “night” period.(3)The grazing time appeared to be correlated with the length and dampness of the herbage and the milk yield.(4)The time spent chewing cud appeared to be correlated with a low moisture content and a high proportion of fibre in the herbage consumed.(5)In warm weather the cows preferred to graze during the cooler periods in the morning and evening, and to rest during period of high temperatures.(6)The cows drank water on one, two or three occasions during 24 hours.(7)The cows had five grazing cycles during 24 hours and the time between cycles was occupied by chewing cud and resting.(8)Grazing was independent of change of light and some grazing took place during the hours of darkness, particularly in spring and autumn.(9)The cows first ate the tips of grass leaves before starting on the remainder of the shoots.(10)When dual grazing is practised there is likely to be a transference of fertility from the “day” to the “night” paddock. The average time spent grazing was 7 hours and approximately 61/4 hours were spent chewing cud. The average figures indicated that 42% of the grazing time took place during the “day” inter-milking period and 58% during the “night” period. The grazing time appeared to be correlated with the length and dampness of the herbage and the milk yield. The time spent chewing cud appeared to be correlated with a low moisture content and a high proportion of fibre in the herbage consumed. In warm weather the cows preferred to graze during the cooler periods in the morning and evening, and to rest during period of high temperatures. The cows drank water on one, two or three occasions during 24 hours. The cows had five grazing cycles during 24 hours and the time between cycles was occupied by chewing cud and resting. Grazing was independent of change of light and some grazing took place during the hours of darkness, particularly in spring and autumn. The cows first ate the tips of grass leaves before starting on the remainder of the shoots. When dual grazing is practised there is likely to be a transference of fertility from the “day” to the “night” paddock.