Extraction, characterization and potential applications of cellulose in corn kernels and Distillers’ dried grains with solubles (DDGS)

Cellulose with properties suitable for films and absorbents has been extracted from corn kernels and DDGS. Although DDGS is an inexpensive and abundant co-product that contains valuable components, it is currently not being used for industrial applications. DDGS contains about 9–16% cellulose by weight but the properties of cellulose in DDGS or even in corn kernels such as degree of polymerization (DP), morphology and crystallinity of cellulose have not been studied. In this study, cellulose was extracted from corn kernels and DDGS using alkali and enzymes. A minimum crude cellulose yield of 1.7% and 7.2% with cellulose content of 72% and 81% was obtained from corn kernels and DDGS, respectively. The solids obtained after extraction with cellulose contents ranging from 35% to 81% were made into films with tensile strength and elongation up to 42.5 MPa and 3.3%, respectively, using water and without any additional chemicals. The cellulose obtained holds water up to 9 times its weight and could therefore be used as an absorbent. The cellulose could also be used as paper, composites, lubricant and nutritional supplement.     

Generating conservation kernels to select areas to control red fox (Vulpes vulpes): Potential implications for pest management practice in state forests

Summary In Australia, controlling introduced predators across large areas is unlikely to be successful without careful consideration of the predator's ecology, the economics of the control exercise and the distribution of the taxa to be protected from the predator. Inadequate strategic planning in pest control is commonplace and there is a need for better methods for determining where, when and how to control predators. The present paper describes a method (currently being introduced into planning programmes) of using areas of high prey species integrity (conservation kernels) to identify strategically optimal areas for predator control (particularly Red Fox, Vulpes vulpes ), across broad landscapes. These landscapes are selected using a geographical information system and a combination of predictive habitat models and records of threatened species at risk of predation by the Red Fox, to identify sites of biological wealth. We propose this method as a first step in developing a strategic predator control plan.     

The systems analysis approach to mechanosensory coding

An important problem in neuroscience is to obtain quantitative knowledge of how information is represented, or encoded, in the signals that nerve cells process and transmit. Sensory receptors have provided important models for the study of neural coding because their inputs can often be relatively easily controlled and measured, while the resultant activity is recorded. A variety of engineering concepts have been successfully applied to physiological sciences, particularly those related to control of dynamic systems. Linear systems analysis was one of the earliest methods used to probe sensory coding, and measurements such as step responses and frequency responses have become standard tools for describing sensory functions. Modern systems analysis has evolved to provide accurate and efficient linear identification of encoding in sensory receptors that use either graded potentials or action potentials. It has also led to nonlinear systems analysis, the creation of parametric nonlinear models, and measures of information coding by sensory neurons. These methods promise to provide important new knowledge about sensory systems in the future, especially when complemented with parallel biophysical and molecular studies of sensory neurons. Mechanoreceptors provided some of the earliest preparations for the investigation of neural coding, and both the linear and nonlinear properties of wide variety of vertebrate and invertebrate mechanoreceptors continue to be explored. This article is part of a special issue on Neuronal Dynamics of Sensory Coding.     

Statistical mechanics of relative species abundance

Statistical mechanics of relative species abundance (RSA) patterns in biological networks is presented. The theory is based on multispecies replicator dynamics equivalent to the Lotka–Volterra equation, with diverse interspecies interactions. Various RSA patterns observed in nature are derived from a single parameter related to productivity or maturity of a community. The abundance distribution is formed like a widely observed left-skewed lognormal distribution. It is also found that the “canonical hypothesis” is supported in some parameter region where the typical RSA patterns are observed. As the model has a general form, the result can be applied to similar patterns in other complex biological networks, e.g. gene expression.     

Energy and nutrient use of palm kernels, palm kernel meal and palm kernel oil in diets for growing pigs

A metabolism experiment was conducted with 13 gilts over four periods to investigate the effects of age or weight of pigs, level of inclusion and methods of estimation of apparent digestible (DE) and metabolizable (ME) energy and nutrient digestibility of full-fat palm kernels (FFPK), recombined palm kernel oil and meal (OPKM) and palm kernel oil (PKO). Each palm kernel product was evaluated at levels equivalent to added oil of 40, 80 and 120 g kg⁻¹ in a basal diet. Extracted palm kernel meal (PKM) was also evaluated in the basal diet at the same level as in OPKM. Thus, 13 treatments arranged in four blocks (time periods) constituted the experimental data analysed using a randomised complete block design. Digestible energy and ME contents and apparent digestibility of nitrogen (ADN), dry matter (ADD) and oil (AOD - employing two oil analytical methods) of palm kernel products were estimated by single level assay and by regression with the latter yielding DE values of 40.2, 19.5, 22.1 and 13.1 MJ/kg DM for PKO, FFPK, OPKM and PKM, respectively. The corresponding values for AOD were 1.08, 0.93, 1.03 and 0.88. While the level of inclusion and pig weight (over the range 40–76 kg) did not significantly affect dietary energy and nutrient digestibility of palm kernel products, the form of oil inclusion had considerable effect with OPKM being better utilized than FFPK. Digestibility of oil in the palm kernel products measured by the ether extract (EE) method was, in general, significantly higher than that estimated by the acid ether extract (AEE) procedure. The results suggest the necessity for digestibility coefficients of oils and fats in oil bearing ingredients to be re-evaluated in the light of the currently applied analytical method as figures obtained using the traditional ether extract method may not be applicable to the true nutritional value of feed ingredients and consequently may lead to imprecise diet formulation.