title: Collagen extraction from animal skin

authors: Matinong, Andrea Marie E.

subjects: Science & Technology

abstract: Collagen is the most abundant structural protein in animals. It is the major component of skin. It finds uses in cosmetics, medicine, yarn production and packaging. This paper reviews the extraction of collagen from hides of most consumed animals for meat with the focus on literature published since 2000. The different pretreatment and extraction techniques that have been investigated for producing collagen from animal skins are reviewed. Pretreatment by enzymatic, acid or alkaline methods have been used. Extraction by chemical hydrolysis, salt solubilization, enzymatic hydrolysis, ultrasound assisted extraction and other methods are described. Post-extraction purification methods are also explained. This compilation will be useful for anyone wishing to use collagen as a resource and wanting to further improve the extraction and purification methods.

text: Collagen extraction from animal skin Collagen is the most abundant structural protein in animals. It is the major component of skin. It finds uses in cosmetics, medicine, yarn production and packaging. This paper reviews the extraction of collagen from hides of most consumed animals for meat with the focus on literature published since 2000. The different pretreatment and extraction techniques that have been investigated for producing collagen from animal skins are reviewed. Pretreatment by enzymatic, acid or alkaline methods have been used. Extraction by chemical hydrolysis, salt solubilization, enzymatic hydrolysis, ultrasound assisted extraction and other methods are described. Post-extraction purification methods are also explained. This compilation will be useful for anyone wishing to use collagen as a resource and wanting to further improve the extraction and purification methods.

year: 2022-06-13

title: Carbon storage and DNA absorption in allophanic soils and paleosols

authors: Huang, Yu-Tuan

subjects: Andisols

abstract: Andisols and andic paleosols dominated by the nanocrystalline mineral allophane sequester large amounts of carbon (C), attributable mainly to its chemical bonding with charged hydroxyl groups on the surface of allophane together with its physical protection in nanopores within and between allophane nanoaggregates. C near-edge X-ray absorption fine structure (NEXAFS) spectra for a New Zealand Andisol (Tirau series) showed that the organic matter (OM) mainly comprises quinonic, aromatic, aliphatic, and carboxylic C. In different buried horizons from several other Andisols, C contents varied but the C species were similar, attributable to pedogenic processes operating during developmental upbuilding, downward leaching, or both. The presence of OM in natural allophanic soils weakened the adsorption of DNA on clay; an adsorption isotherm experiment involving humic acid (HA) showed that HA-free synthetic allophane adsorbed seven times more DNA than HA-rich synthetic allophane. Phosphorus X-ray absorption near-edge structure (XANES) spectra for salmonsperm DNA and DNA-clay complexes indicated that DNA was bound to the allophane clay through the phosphate group, but it is not clear if DNA was chemically bound to the surface of the allophane or to OM, or both. We plan more experiments to investigate interactions among DNA, allophane (natural and synthetic), and OM. Because DNA shows a high affinity to allophane, we are studying the potential to reconstruct late Quaternary palaeoenvironments by attempting to extract and characterise ancient DNA from allophanic paleosols

text: Carbon storage and DNA absorption in allophanic soils and paleosols Andisols and andic paleosols dominated by the nanocrystalline mineral allophane sequester large amounts of carbon (C), attributable mainly to its chemical bonding with charged hydroxyl groups on the surface of allophane together with its physical protection in nanopores within and between allophane nanoaggregates. C near-edge X-ray absorption fine structure (NEXAFS) spectra for a New Zealand Andisol (Tirau series) showed that the organic matter (OM) mainly comprises quinonic, aromatic, aliphatic, and carboxylic C. In different buried horizons from several other Andisols, C contents varied but the C species were similar, attributable to pedogenic processes operating during developmental upbuilding, downward leaching, or both. The presence of OM in natural allophanic soils weakened the adsorption of DNA on clay; an adsorption isotherm experiment involving humic acid (HA) showed that HA-free synthetic allophane adsorbed seven times more DNA than HA-rich synthetic allophane. Phosphorus X-ray absorption near-edge structure (XANES) spectra for salmonsperm DNA and DNA-clay complexes indicated that DNA was bound to the allophane clay through the phosphate group, but it is not clear if DNA was chemically bound to the surface of the allophane or to OM, or both. We plan more experiments to investigate interactions among DNA, allophane (natural and synthetic), and OM. Because DNA shows a high affinity to allophane, we are studying the potential to reconstruct late Quaternary palaeoenvironments by attempting to extract and characterise ancient DNA from allophanic paleosols

year: 2014

title: Enabling conditions for professional development of te reo Māori teachers

authors: Franken, Margaret

subjects: Māori language teachers

abstract: The paper outlines a professional development programme for secondary school teachers of te reo Māori (under the auspices of Te Hiringa i te Mahara) conducted by a language teacher educator and an expert in Māori bilingualism and biliteracy. While the principles underpinning the programme reflect a strong task-based
orientation, the programme approached development needs for the teachers from the point of view of understanding “enabling conditions” (Franken, Rau, Ngata & Parata, n.d.) for effective language learning and teaching (see also Ellis, 2005),
rather than understanding task based learning and teaching per se. The programme drew on the current practices of the teachers and made use of epistemology of Māori language and Māori language learning. The paper presents observations from monitoring data collected during the programme supporting the claim that such an approach to the professional development of language teachers promotes a strong knowledge base and pedagogical reasoning skills (Richards, 1998), and in particular for te reo Māori teachers, fosters a sense of their own professional identity.

text: Enabling conditions for professional development of te reo Māori teachers The paper outlines a professional development programme for secondary school teachers of te reo Māori (under the auspices of Te Hiringa i te Mahara) conducted by a language teacher educator and an expert in Māori bilingualism and biliteracy. While the principles underpinning the programme reflect a strong task-based
orientation, the programme approached development needs for the teachers from the point of view of understanding “enabling conditions” (Franken, Rau, Ngata & Parata, n.d.) for effective language learning and teaching (see also Ellis, 2005),
rather than understanding task based learning and teaching per se. The programme drew on the current practices of the teachers and made use of epistemology of Māori language and Māori language learning. The paper presents observations from monitoring data collected during the programme supporting the claim that such an approach to the professional development of language teachers promotes a strong knowledge base and pedagogical reasoning skills (Richards, 1998), and in particular for te reo Māori teachers, fosters a sense of their own professional identity.

year: 2009