Fibrous Constituents Research Articles

Effect of cutting time and storage time on the nutritional value of stargrass hay

The objective of this study was to assess the effect of cutting time on the nutritional composition and dehydration rate of stargrass, as well as the nutritional value of the hay as a function of storage time. Two plant cutting times were analyzed: at 13:00 (H13) and 17:00 (H17). After cutting, the dehydration rate of both the plant and its fractions until baling was monitored. The bales were checked for nutritional composition and digestibility after 30, 60, 90 and 120 days. At the time of cutting, a difference was observed for the concentrations of ethanol-soluble carbohydrates, which were higher for H17 (90.3 g kg-1) compared to H13 (52.9 g kg-1). Leaf dehydration rates were higher in the H17 treatment. Cutting time had no influence on the nutritional value of the hay. With storage time, there was an increase in the levels of neutral detergent fiber and acid detergent fiber, and a reduction in the content of ethanol-soluble carbohydrates. It was concluded that cutting at 17:00 allows for a greater accumulation of soluble carbohydrates in the plant. Cutting time does not change the time required for dehydration and the nutritional value of the hay. Storage time reduces soluble components and increases fibrous constituents

316 Determination of the Chemical and Phytochemical Composition of the Methanolic Extract of Urochloa Humidicola for Use as a Phytogenic Additive in Ruminant Diets

Abstract Plant extract is an excellent alternative to reduce methane emissions and ameliorate ruminal fermentation due the presence of the secondary metabolites, however, there are many studies with plants used on human’s diet that shows a good result but may occur competition and elevate the costs for the system. Plants consumed by animal have secondary metabolites in quantity and diversity, it can be a good strategy. This work aimed to determine the bromatological composition and characterize the Urochloa humidicola methanol extract such as the presence of secondary metabolites. The samples of the leaves of U. humidicola were collected, dried in the shade with temperature below 40°C, ground in a willey mill in 2 mm particles and subjected to cold maceration with methanol. The solution obtained was filtered by filter paper and concentrated in a rotary evaporator and put to finish the process, drying under airflow. The results of bromatological analyses were subjected to ANOVA by comparing averages by Fisher’s test using the 9.1 Saeg software and phytochemical prospecting testes were characterized as the intensity of the presence of each class of metabolites and represented via the cross-system where:(+++) implies a large presence, (++) implies a considerable presence, (+) implies a small presence and (0) implies a no presence. The dry crude methanolic extract was subjected to analysis of chemical composition and phytochemical prospecting. The extract showed 10.20% crude protein and 35% ether extract and traces of fibrous constituents, because the methanol extraction extracted only soluble constituents. A phytochemical prospecting was positive for the presence of saponin. tannin, alkaloids, catechins, non-protein amino acids and saccharides and was negative for the presence of flavonoids and purines. The U. humidicola methanol extract can be used as a phytogenic additive in the feeding of ruminants.

Local micromorphic non-affine anisotropy for materials incorporating elastically bonded fibres

There has been increasing experimental evidence of non-affine elastic deformation mechanisms in biological soft tissues. These observations call for novel constitutive models which are able to describe the dominant underlying micro-structural kinematic aspects, in particular relative motion characteristics of different phases. This paper proposes a flexible and modular framework based on a micromorphic continuum encompassing matrix and fibre phases. In addition to the displacement field, it features so-called director fields which can independently deform and intrinsically carry orientational information. Accordingly, the fibrous constituents can be naturally associated with the micromorphic directors and their non-affine motion within the bulk material can be efficiently captured. Furthermore, constitutive relations can be formulated based on kinematic quantities specifically linked to the material response of the matrix, the fibres and their mutual interactions. Associated stress quantities are naturally derived from a micromorphic variational principle featuring dedicated governing equations for displacement and director fields. This aspect of the framework is crucial for the truly non-affine elastic deformation description. In contrast to conventional micromorphic approaches, any non-local higher-order material behaviour is excluded, thus significantly reducing the number of material parameters to a range typically found in related classical approaches. In the context of biological soft tissue modelling, the potential and applicability of the formulation is studied for a number of academic examples featuring anisotropic fibre-reinforced composite material composition to elucidate the micromorphic material response as compared with the one obtained using a classical continuum mechanics approach.

On fibre dispersion in anisotropic soft biological tissues using fourth-order structural tensors

Developments in microscopic imaging techniques for soft biological tissues have greatly improved understanding of their underlying microstructures, notably the three-dimensional orientation and dispersion of fibrous constituents. In structural constitutive modelling, assuming that the collagenous and muscle fibres in soft tissues are perfectly aligned along a prescribed orientation can limit the ability to accurately predict the experimentally detected stress–strain response of biological samples. The objective of this paper is to extend the representation of hyperelasticity for anisotropic bodies using fourth-order structural tensors (FOSTs) to incorporate the effects of fibre dispersion according to the generalised structural tensor (GST) approach. Dispersion within a family of reinforcing collagen fibres is a common phenomenon in soft tissues which alters their overall mechanical behaviour. The FOST-based representation of the strain energy density function (SEF) separates the constitutive properties of the continuum from the nonlinear descriptions of geometric deformations; with each of these being described by different fourth-order tensors. The constant-valued material and structural properties of the continuum reside within fourth-order material tensors referred to as the anisotropic Lamé tensors. Nonlinearity in the model is then solely applied to the components of the displacement gradient tensor in fourth-order strain measures. The framework provided leads to a unique set of fourteen generalised FOSTs for two-direction preferred hyperelasticity including fibre families which are dispersed according to normalised distributions. In the absence of dispersion, the model collapses to the conventional FOST-based model. Models for the hyperelastic response of arterial wall and passive ventricular myocardium tissues are postulated and show good agreement with experimental data using minimal ground-state material constants.

Fiber-reinforced composites: nonlinear elasticity and beyond

A fiber-reinforced material comprised of a soft polymeric matrix reinforced with polymeric filaments is often modeled as an equivalent anisotropic nonlinearly elastic solid. Although the response of a single constituent polymeric material can be modeled by nonlinear thermo-elasticity over a large range of deformations and temperatures, there can be conditions requiring a theory that extends the range of application to account for other features, such as nonlinear viscoelasticity and an evolving microstructure due to a combination of mechanical and nonmechanical factors. In a multi-constituent fiber-reinforced material these effects can be expected to occur with different initial triggering and ongoing potency in the separate polymer matrix and fiber constituents. This paper summarizes a number of constitutive models for fiber-reinforced materials that include these features, discusses the connection of these models to a nonlinearly elastic scaffold, provides a framework for the incorporation of these features into the constitutive theory for an equivalent general simple solid, and shows how certain terms in the mathematical structure can be associated with the matrix constituent while other terms can associated with the fibrous constituent.

Abstract P518: Intravascular Ultrasound Assisted Endovascular Revascularization in Patients With Subacute and Chronic Internal Carotid Artery Occlusions

Background: Revascularization of subacute or chronic internal carotid artery occlusion is technically feasible in some patients but carotid revascularization procedure needs to be optimized to improve the clinical success of the procedure. Objective: To describe our experience using intravascular ultrasound (IVUS) as adjunct to carotid revascularization procedure in patients with subacute or chronic internal carotid artery occlusion. Materials and Methods: Endovascular recanalization was attempted in 7 patients with symptomatic internal carotid artery occlusions between 3 and 11 days of symptoms onset. Distal protection device was deployed in all the patients followed by advancement of IVUS catheter (Eagle Eye Gold, 20 MHZ Digital, s5 Imaging System, Volcano Corp.) to obtain gray-scale and virtual histology (VH) images at regions of interest. IVUS images used to categorize occlusion content as: dark green- fibrous; yellow/green- fibrofatty; white- calcified; red- necrotic lipid core plaque on images. Intravascular thrombus was diagnosed an echolucent, homogeneous, well-delineated, diaphragm-like intraluminal structure. Results: The occlusion was recanalized successfully in all of 7 patients with median age 67.4±7.5 years. IVUS demonstrated intravascular thrombus in 5 of 7 patients. Fibrous and fibrofatty constituents of plaque were seen in 5 of the 7 patients in whom VH was done. Calcification and lipid necrotic core each were seen in 3 of 5 patients.5 patients with large thrombus burden on IVUS were treated using aspiration thrombectomy. Six of seven patients underwent stent placement and one patient underwent primary angioplasty. 5 of 7 patients had modified Rankin Scale of 0-2 at follow up (3 weeks to 4 months post procedure). Conclusions: IVUS provided valuable information to optimize carotid revascularization procedure in patients with subacute or chronic internal carotid artery occlusion.

Anaerobic co-digestion of animal manure at different waste cooking oil concentrations

ABSTRACT: This study aimed to obtain the best dose of waste cooking oil inclusion for the co-digestion of substrates prepared with dairy cattle and swine manure in order to maximize solids reductions and biogas yield. Analyses of total solids (TS), volatile solids (VS), and neutral detergent fiber (NDF) were performed during the loading and unloading of digesters, while biogas yield was measured twice a week. The maximum reduction in VS (51.4%) was reached with the inclusion of up to 54.6g waste cooking oil.kg manure-1. Maximum NDF degradation occurred with inclusions of up to 69.4g waste cooking oil.kg manure-1. Inclusions of up to 64g of waste cooking oil.kg manure-1 provided specific biogas yield of 291.4 and 251.0L biogas.kg VS-1 added to substrates with swine and cattle manure, respectively. Adding oil at doses between 45.1 and 69.4g waste cooking oil kg manure-1 to substrates composed of cattle or swine manure maximizes reductions of solids and fibrous constituents and enhances specific biogas yield. Furthermore, swine manure supports higher doses of waste cooking oil.

Asbestiform minerals in ophiolitic rocks of Calabria (southern Italy)

ABSTRACTOphiolitic rocks cropping on Calabria territory, southern Italy, can hold asbestiform minerals potentially harmful for human health. The aim of this work was to detect the fibrous phases of ophiolites along the Coastal Chain of northern Calabria and southern part of the Sila massif. Above 220 massive samples were collected in the study areas and analyzed using optical and electron microscopy, X-ray diffractometry, and Fourier transform infra-red spectrometry. The main fibrous constituent belonged to tremolite-actinolite series followed by fibrous antigorite that becomes more abundant in the samples collected in Reventino Mount surroundings. Results highlighted that serpentinites samples mainly consisted of antigorite and minor chrysotile. Samples collected along the coastal chain of northern Calabria did not hold fibrous materials. The results will be useful for Italian natural occurrences of asbestos (NOA) mapping in order to avoid an unintentional exposition by human activity or weathering processes.

ALTERNATIVES FOR SPRING FORAGE EMPTINESS IN PAMPA, BRAZIL

The spring forage emptiness is an obstacle to the development of Brazilian livestock, including in the Bioma Pampa region. Feed strategies for this period contributed to the development of livestock and to the conservation of the biome. The objective of this work was to know the nutritional potential of forages during spring forage for use as strategies in the forage planning. The experiment had a completely randomized design, with ten forages and four replicates. The chemical composition, in vitro dry matter digestibility (IVDMD) and the total digestible nutrient content (NTD) of elephant grass, brachiaria cultivars Convert and Marandu, Tifton 68; diploid and tetraploid ryegrass; red, white and arrowleaf clover; and bird’s-foot trefoil. The grasses had a higher proportion of fibrous constituents, and lower levels of NDT and DMD, thus, lower nutritional value. Negative correlation between mineral matter and fibrous constituents with CP, TDN and IVDMD, was observed. Forages studied can be used as pasture alternatives for ruminants in the spring forage emptiness of the Pampa, Brazil, however, the strategy of using them should be a pasture planning.

Contribute of crude glycerin to increase the efficiency of anaerobic digestion process of dairy cattle manure

The objective of this study was to determine the optimal inclusion doses of crude glycerin in anaerobic co‐digestion with dairy cattle manure processed at 10, 17, and 24 days of retention in order to maximize reductions in solid and fibrous constituents and increase the productions of biogas and methane. Semi‐continuous digesters were fed with daily loads of substrates containing doses of 0, 5 and 10% (based on total solids, TS) of crude glycerin and dairy cattle manure. The highest specific productions of biogas and methane with the 10‐day HRT were also achieved in substrates with 0% glycerin, reaching values of 0.91 and 1.27 L/g of TS and solids (VS) added, respectively. In substrates retained for 17 and 24 days the values were maximal with addition of glycerin doses between 2.7 and 3.6% resulting in yields of 1.72 and 2.42 L of biogas per gram of TS added and 2.37 and 3.31 L of biogas per gram of VS added, respectively. For methane production, the optimal inclusion doses of crude glycerin with HRTs of 10, 17, and 24 days were 0.0, 3.7, and 3.3%, generating 0.70, 1.43, and 1.86 L of methane per gram of VS added. The inclusion of crude glycerin in co‐digestion with dairy cattle manure is not recommended for digesters operated with retention time of 10 days. However, when substrates remain for 17 or 24 days this inclusion promotes reductions of solids constituents while maximizing the specific productions of biogas and methane. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 1305–1311, 2018

Development of a rapid matrix digestion technique for ultrastructural analysis of elastic fibers in the intervertebral disc

Collagen and elastic fibers are two major fibrous constituents of the annulus fibrosus (AF) in the disc that contribute to its mechanical and viscoelastic properties. It was thought that elastic fibers play no substantial role in the function and properties of the disc as these fibers were irregularly distributed. Studies that have revealed highly organized elastic fibers with different regional orientation and distribution, while being strongly crosslinked with matrix, suggesting their contribution to disc structure-function properties. These studies that were performed by light microscopic analysis of histologically prepared samples, have not been able to reveal the fine-scale architectural details of the elastic fiber network. Since elastic fibers are intermingled with other fibrous components of the disc and mostly obscured by the extracellular matrix, it is difficult to demonstrate their ultra-structural organization using scanning electron microscopy (SEM).Therefore the aim of this study was to develop a rapid matrix digestion technique for ultrastructural analysis of the disc elastic fibers. This study provides a new method for fundamental visualization of elastic fibers and their architecture in the disc. Through the ultra-structural analysis, the relationship between structure and function, as well as the role of elastic fibers on AF mechanical properties can be studied. This method may be used to develop a three-dimensional map of elastic fibers distribution within the disc, which would provide valuable information for designing tissue engineered scaffolds for AF repair and replacement.

A novel constitutive model for passive right ventricular myocardium: evidence for myofiber–collagen fiber mechanical coupling

The function of right ventricle (RV) is recognized to play a key role in the development of many cardiopulmonary disorders, such as pulmonary arterial hypertension (PAH). Given the strong link between tissue structure and mechanical behavior, there remains a need for a myocardial constitutive model that accurately accounts for right ventricular myocardium architecture. Moreover, most available myocardial constitutive models approach myocardium at the length scale of mean fiber orientation and do not explicitly account for different fibrous constituents and possible interactions among them. In the present work, we developed a fiber-level constitutive model for the passive mechanical behavior of the right ventricular free wall (RVFW). The model explicitly separates the mechanical contributions of myofiber and collagen fiber ensembles, and accounts for the mechanical interactions between them. To obtain model parameters for the healthy passive RVFW, the model was informed by transmural orientation distribution measurements of myo- and collagen fibers and was fit to the mechanical testing data, where both sets of data were obtained from recent experimental studies on non-contractile, but viable, murine RVFW specimens. Results supported the hypothesis that in the low-strain regime, the behavior of the RVFW is governed by myofiber response alone, which does not demonstrate any coupling between different myofiber ensembles. At higher strains, the collagen fibers and their interactions with myofibers begin to gradually contribute and dominate the behavior as recruitment proceeds. Due to the use of viable myocardial tissue, the contribution of myofibers was significant at all strains with the predicted tensile modulus of [Formula: see text]32kPa. This was in contrast to earlier reports (Horowitz etal. 1988) where the contribution of myofibers was found to be insignificant. Also, we found that the interaction between myo- and collagen fibers was greatest under equibiaxial strain, with its contribution to the total stress not exceeding 20%. The present model can be applied to organ-level computational models of right ventricular dysfunction for efficient diagnosis and evaluation of pulmonary hypertension disorder.

Comparative study of cellulose nanofiber blending effect on properties of paper made from bleached bagasse, hardwood and softwood pulps

Cellulose nanofibers (CNFs) offer the motivational prospective for a native fibrous constituent that can exceed the mechanical performance of plant fibers in current use for commercial products. In this research work, CNFs were prepared with an increased extent of mechanical refining from bleached bagasse, hardwood and softwood pulp fibers. These prepared CNFs were investigated by using the FE-SEM technique. During the increased refining process, partial fibrillation on the fiber surfaces was created, and these fibers were converted from the micro- to nano-scale through nanofibrillation. This shows the significant effect on the tensile, burst and tear strengths of paper made from unrefined and refined fibers. However, the optical properties remained almost constant with increases of the percentage of CNF and decreased significantly with increases of the refining intensity due to fiber damage. The strength properties of reinforced paper sheets were greater than those of paper sheets without reinforcement. The main drawback of this process is that the drainage time is longer with an increasing percentage of CNF in refined and unrefined pulp fibers.

Stress-strain behaviour and shear strength of Municipal Solid Waste (MSW)

An understanding of the stress-strain behaviour of Municipal Solid Waste (MSW) is important in landfill design and stability analysis of landfill slopes. A series of triaxial compression tests were carried out on reconstituted MSW specimens. The effect of stress path on the drained stress-strain response and shear strength of MSW were investigated. For the compression stress paths of Δσ3≥0, a straight-lined increase section and an upward curvature are observed in the stress-strain curves of MSW; the upward curvature results from the fibrous constituents (primarily plastic and paper) reinforcing the waste matrix; the hardening points defined in stress-strain curves are used as failure criterion to calculate the strength parameters of MSW. For the compression stress paths of Δσ3 < 0, the stress-strain responses of MSW exhibit a rapidly increasing section towards a slowly increasing section without upward curvature; the development of fibrous reinforcement is not enough due to the reduction of confining stress σ3; the failure points defined in stress-strain curves are also used as failure criterion to calculate the strength parameters of MSW. A new method to estimate MSW strength parameters is proposed in this study. The differences of MSW friction angle are very small for different stress path tests. However, the cohesions obtained in compression stress path tests of Δσ3 < 0 are much smaller than that in conventional triaxial compression tests.

Effects of nutrition on digestion efficiency and gaseous emissions from slurry in growing pigs: III. Influence of varying the dietary level of calcium soap of palm fatty acids distillate with or without orange pulp supplementation

The aim of this study was to establish the relationships between faecal fat concentration and gaseous emissions from pig slurry. Five diets were designed to meet essential nutrient requirements: a control and four experimental feeds including two levels (35 or 70g/kg) of calcium soap fatty acids distillate (CSP) and 0 or 200g/kg of orange pulp (OP) combined in a 2×2 factorial structure. Thirty growing pigs (six per treatment) were used to measure dry matter (DM) and N balance, coefficients of total tract apparent digestibility (CTTAD) of nutrients, faecal and urine composition and potential emissions of ammonia (NH3) and methane (CH4). Increasing dietary CSP level decreased DM, ether extract (EE) and crude protein (CP) CTTAD (by 4.0, 11.1 and 3.5%, respectively, P<0.05), but did not influence those of fibrous constituents. It also led to a decrease (from 475 to 412g/kg DM, P<0.001) of faecal concentration of neutral detergent fibre (aNDFom) and to an increment (from 138 to 204g/kg, P<0.001) of EE in faecal DM that was related to greater CH4 emissions, both per gram of organic matter (P=0.021) or on a daily basis (P<0.001). Level of CSP did not affect N content in faeces or urine, but increased daily DM (P<0.001), and N (P=0.031) faecal excretion with no effect on urine N excretion. This resulted in lesser (P=0.036) NH3 potential emission per kg of slurry. Addition of OP decreased CTTAD of EE (by 7.9%, P=0.044), but increased (P<0.05) that of all the fibrous fractions. As a consequence, faecal EE content increased (from 165 to 177g/kg DM; P=0.012), and aNDFom decreased greatly (from 483 to 404g/kg DM, P<0.001), which in all resulted in a lack of effect of OP on CH4 potential emission. Inclusion of OP in the diet also led to a significant decrease of CP CTTAD (by 6.85%, P<0.001), and to an increase of faecal CP concentration (from 174 to 226g/kg DM, P<0.001), with no significant influence on urine N content. These effects resulted in higher N faecal losses, especially those of the undigested dietary origin, without significant effects on potential NH3 emission. No significant interactions between CSP and OP supplementation were observed for the gaseous emissions measured.

Mechanistic micro-structural theory of soft tissues growth and remodeling: tissues with unidirectional fibers

A new mechanistic theory was developed for soft tissues growth and remodeling (G&R). The theory considers tissues with unidirectional fibers. It is based on the loading-dependent local turnover events of each constituent and on the resulting evolution of the tissue micro-structure, the tissue dimensions and its mechanical properties. The theory incorporates the specific mechanical properties and turnover kinetics of each constituent, thereby establishing a general framework which can serve for future integration of additional mechanisms involved in G&R. The feasibility of the theory was examined by considering a specific realization of tissues with one fibrous constituent (collagen fibers), assuming a specific loading-dependent first-order fiber's turnover kinetics and the fiber's deposition characteristics. The tissue was subjected to a continuous constant rate growth. Model parameters were adopted from available data. The resulting predictions show qualitative agreement with a number of well-known features of tissues including the fibers' non-uniform recruitment density distribution, the associated tissue convex nonlinear stress-stretch relationship, and the development of tissue pre-stretch and pre-stress states. These results show that mechanistic micro-structural modeling of soft tissue G&R based on first principles can successfully capture the evolution of observed tissues' structure and size, and of their associated mechanical properties.

Experimental Investigation of the Effect of Fibrous Reinforcement on Shear Resistance of Soil-Waste Mixtures

The effect of fibrous waste reinforcement on the shear resistance of soil-waste mixtures is experimentally investigated using a large (30 cm × 30 cm × 18 cm) direct shear box. Analogies in shear response to fiber-reinforced soils (FRS) are identified. Specimens are reconstituted at varying fibrous waste orientations using a custom-made specimen preparation split mold. Tests on soil-waste mixtures with waste fibrous constituents, i.e., paperboard, plastic and wood, commonly encountered in municipal solid waste (MSW) landfills are performed. Fibrous constituents are characterized by performing tensile tests and interface testing. The experimental data confirms that the shearing response of soil-waste mixtures is analogous to that of FRS and provides a basis for explaining the fiber reinforcement effect of MSW. It was found that the presence of fibrous constituents results in significant anisotropy in shear resistance of the direct shear specimens with fiber reinforcement contribution being a function of the reinforcement orientation and the type of fiber. The impact of reinforcement orientation on the shear strength of the specimens is significant. The largest increase in shear resistance of the specimens is observed for a reinforcement angle of 60° with respect to the shear plane, consistent with findings of previous studies on FRS. Wood fibers exhibit the highest tensile strength and the lowest strain at failure as well as the highest interface strength with soil, compared to paperboard and plastic fibers. Wood fibers also contribute the most to the shear resistance of soil-waste mixtures. For these mixtures, similarly to FRS, once the amount of reinforcement exceeds a certain threshold, it does not contribute further to reinforcement. Results of this investigation indicate that the previously recommended strength envelopes for MSW may not account for the significant fibrous reinforcement effect, although lower shear resistances may be observed in direct shear when shearing occurs parallel to plastic fibrous constituents.

Drained response of municipal solid waste in large-scale triaxial shear testing

A comprehensive laboratory investigation was performed on municipal solid waste (MSW) from a landfill located in northern California using a large-scale triaxial (TX) apparatus. An improved, standardized waste specimen preparation method was developed and used to prepare 27 large-scale TX specimens (d=300mm, h=600–630mm). The effects of waste composition, confining stress, unit weight, loading rate, and stress path on the drained stress–strain response of MSW were investigated. Waste composition has a significant effect on its stress–strain response. The commonly observed upward curvature of the stress–strain response of specimens composed of larger-sized waste materials results from the fibrous constituents (primarily paper, plastic and wood) reinforcing the waste matrix. This effect is greatest when the MSW specimen is sheared across the long axis of the fibrous particles. Due to this significant strain hardening effect and waste’s in situ stress state, a limiting strain failure criterion of 5% axial strain from the Ko field consolidation state is judged to be most appropriate. Results from this test program and data from the literature indicate that the TX compression secant friction angle of MSW varies from 34° to 44°, with 39° as a best estimate, at a confining stress of one atmosphere (assuming c=0). The friction angle decreases as confining stress increases. The friction angles measured in this testing program are representative of failure surfaces that are oriented at an angle to the predominant orientation of the long axis of the fibrous waste particles. These friction angles are higher than those obtained in direct shear tests where shearing typically occurs parallel to the orientation of the fibrous waste particles.

Thermogravimetric analysis of plant water content in relation with heavy metal stress

We have used simultaneous thermogravimetry & differential scanning calorimetry (TG/DSC) to estimate water content of wheat plants exposed to toxic concentration of copper and cadmium. Our study revealed that water content tends to decrease along with the increase of the exogenous heavy metal supply. These data suggested a different status of water: on the one hand, form an organ to another, and on the other hand, in stressed plants compared with control plants. The observed differences could be correlated with reshaping processes induced by heavy metal stress, especially at cell wall level. Accumulation of fibrous constituents having important properties like ion binding and water-holding capacity, may affect water distribution and interactions. TG/DSC appears as a promising technique for revealing certain aspects of stress biochemistry and physiology in plants.

Consumo e digestibilidade aparente de dietas com diferentes níveis de inclusão de torta de coco para alimentação de ovinos

The study was conducted at the Universidade Federal da Amazônia to evaluate apparent digestibility and intake for sheep fed diets containing different inclusion levels of fresh coconut meal (25, 50 and 75%). A total of 12 male Santa Inês sheep were used, with a mean age of 5 months and average weight of 19.5 kg, kept in individual metabolic cages distributed in a completely randomized design. Dry matter intake decreased with the inclusion of coconut meal, with values of 699, 405 and 373 g, and 3.67, 2.15 and 2.00% body weight at levels of 25, 50 and 75%, respectively. The same behavior was observed for protein intake; however, no significant differences in intake were observed for values of NDF, ADF and ether extract. Apparent digestibility was reduced (p < 0.05) in the coefficients for treatment with 75% inclusion of coconut meal for dry matter, protein, NDF and ADF, compared to the 25% and 50% treatments. It was concluded that the inclusion of coconut meal in the diet negatively affects the intake and digestibility of fibrous constituents, resulting from high levels of lipids present in the coconut meal