title: Structural characterisation of pre-processed thermoplastic protein derived from bloodmeal

authors: Bier, James Michael

abstract: Additives are required to convert bloodmeal powder into an extrudable thermoplastic protein-based bioplastic. These include a protein denaturant, a surfactant, a reducing agent and plasticisers. The objective of this work was to assess the structural changes induced in bloodmeal by these additives prior to extrusion. Structure was investigated using Fourier transform infrared (FT-IR) spectroscopy, wide angle X-ray scattering (WAXS) and synchrotron light based FT-IR microspectroscopy. 
FT-IR results suggested the additives reduced α-helical content. The shape of the amide I region (1600 – 1700 cm⁻¹, representing carbonyl group stretching in the protein backbone) is known to depend on protein secondary structures. Bloodmeal showed a broad, convoluted peak in this region, with a maximum in the range 1648 – 1658 cm⁻¹, associated with α-helices. With processing additives, a dip was seen in the α-helix region, with twin peaks emerging either side of it. Urea, one of the additives, also absorbs in the amide I region and may also contribute to a change in its shape. Analysis of the amide 3 region supported a reduction in the ratio of α helices to β sheets. Further support of structural changes was shown by WAXS. The additives decreased the sharpness of peaks corresponding to 4.8 Å and 10 Å, thought to represent intra-helix spacing and inter-helix packing respectively.
FT-IR microspectroscopy at the Australian Synchrotron enabled spatial variations in secondary structure to be explored using peaks in the amide 3 region. Spatial distribution of secondary structure was detected in bloodmeal and thermoplastically modified bloodmeal prior to extrusion (PPM-TEG). Bloodmeal showed domain separation on the approximate order of 10 μm, whilst PPM-TEG appeared to have larger phases and overall reduced α-helical content, relative to beta sheets.

text: Structural characterisation of pre-processed thermoplastic protein derived from bloodmeal Additives are required to convert bloodmeal powder into an extrudable thermoplastic protein-based bioplastic. These include a protein denaturant, a surfactant, a reducing agent and plasticisers. The objective of this work was to assess the structural changes induced in bloodmeal by these additives prior to extrusion. Structure was investigated using Fourier transform infrared (FT-IR) spectroscopy, wide angle X-ray scattering (WAXS) and synchrotron light based FT-IR microspectroscopy. 
FT-IR results suggested the additives reduced α-helical content. The shape of the amide I region (1600 – 1700 cm⁻¹, representing carbonyl group stretching in the protein backbone) is known to depend on protein secondary structures. Bloodmeal showed a broad, convoluted peak in this region, with a maximum in the range 1648 – 1658 cm⁻¹, associated with α-helices. With processing additives, a dip was seen in the α-helix region, with twin peaks emerging either side of it. Urea, one of the additives, also absorbs in the amide I region and may also contribute to a change in its shape. Analysis of the amide 3 region supported a reduction in the ratio of α helices to β sheets. Further support of structural changes was shown by WAXS. The additives decreased the sharpness of peaks corresponding to 4.8 Å and 10 Å, thought to represent intra-helix spacing and inter-helix packing respectively.
FT-IR microspectroscopy at the Australian Synchrotron enabled spatial variations in secondary structure to be explored using peaks in the amide 3 region. Spatial distribution of secondary structure was detected in bloodmeal and thermoplastically modified bloodmeal prior to extrusion (PPM-TEG). Bloodmeal showed domain separation on the approximate order of 10 μm, whilst PPM-TEG appeared to have larger phases and overall reduced α-helical content, relative to beta sheets.

year: 2012

title: Book review: Muhammad: a very short introduction

authors: Pratt, Douglas

subjects: book review

abstract: This article reviews the book: “Muhammad: a very short introduction”, edited by Jonathan A.C. Brown.

text: Book review: Muhammad: a very short introduction This article reviews the book: “Muhammad: a very short introduction”, edited by Jonathan A.C. Brown.

year: 2011

title: Māori women and intimate partner violence: Some sociocultural influences

authors: Hoeata, Chloe

subjects: intimate partner violence

abstract: Intimate partner violence (IPV) has recently been acknowledged as a worldwide phenomenon, with approximately one in four intimate relationships containing some form of violence. This study explores the interaction between relationship dynamics, IPV and whānau and community influences. We completed narrative interviews with two Māori women in December 2010. Our findings confirm the results of earlier studies which have found that childhood experiences of violence, actual or witnessed, have a powerful effect that reverberate within adult lives and into the formation of intimate relationships. Our interviews show that Māori whānau and women are textured by the same patriarchal expectations that privilege men in the Pākehā world. We also found that seeking help from whānau to escape a violent relationship may not be the most welcomed course of action. We conclude with a discussion of future research directions.

text: Māori women and intimate partner violence: Some sociocultural influences Intimate partner violence (IPV) has recently been acknowledged as a worldwide phenomenon, with approximately one in four intimate relationships containing some form of violence. This study explores the interaction between relationship dynamics, IPV and whānau and community influences. We completed narrative interviews with two Māori women in December 2010. Our findings confirm the results of earlier studies which have found that childhood experiences of violence, actual or witnessed, have a powerful effect that reverberate within adult lives and into the formation of intimate relationships. Our interviews show that Māori whānau and women are textured by the same patriarchal expectations that privilege men in the Pākehā world. We also found that seeking help from whānau to escape a violent relationship may not be the most welcomed course of action. We conclude with a discussion of future research directions.

year: 2011