title: Effect of stearic acid treatment on the properties of aligned short hemp fibre mats and their potential use as reinforcement in polypropylene matrix composites

authors: Pickering, Kim L.

subjects: Science & Technology

abstract: The main objective of this study was to assess the effect of stearic acid vapour treatment on hemp fibre mats produced using dynamic sheet forming, and the potential use of these treated mats as reinforcement in polypropylene matrix composites. Stearic acid was successfully applied through vapour treatment, appearing to form a layer on fibre surfaces. It was found that the presence of stearic acid increased hydrophobicity and thermal stability of fibre mats. It was also found to increase thermal stability of polypropylene matrix composites as well as their strength.

text: Effect of stearic acid treatment on the properties of aligned short hemp fibre mats and their potential use as reinforcement in polypropylene matrix composites The main objective of this study was to assess the effect of stearic acid vapour treatment on hemp fibre mats produced using dynamic sheet forming, and the potential use of these treated mats as reinforcement in polypropylene matrix composites. Stearic acid was successfully applied through vapour treatment, appearing to form a layer on fibre surfaces. It was found that the presence of stearic acid increased hydrophobicity and thermal stability of fibre mats. It was also found to increase thermal stability of polypropylene matrix composites as well as their strength.

year: 2021

title: Social interaction affects acquisition of lithium chloride-induced conditioned taste aversion: identification of underlying changes in neuronal activation in key forebrain areas

authors: Brunton, Chloe

subjects: aversion

abstract: A conditioned taste aversion (CTA) develops when exposure to a novel tastant is followed by sickness/malaise. Recently, it has been shown that a CTA can be reduced if the animal is placed in a social environment, i.e., in the presence of a conspecific, during the CTA acquisition phase. The current project was aimed to expand on our understanding of this phenomenon by (a) identifying the magnitude of an aversive response to a saccharin solution induced by lithium chloride (LiCl), a known emetic agent, in mice maintained in the social versus non-social setting; and (b) defining differences in LiCl-induced neuronal activation in the key CTA-related forebrain areas of animals in the social and non-social scenario. In mice lacking social stimulation, LiCl at a dose of 1 mEq induced a mild CTA to saccharin and the 6-mEq dose produced a profound aversive response. On the other hand, 6 mEq was the lowest effective dose in mice kept in the social setting. Immunohistochemical analysis of a neuronal activity marker, c-Fos, showed that alteration of activity in the paraventricular nucleus of the hypothalamus (PVN) and central nucleus of the amygdala (CEA) is associated with the observed changes. In LiCl-injected mice subjected to social stimulation, also the percentage of Fos-positive oxytocin (OT), but not vasopressin neurons in the PVN was higher than in LiCl-treated single-housed mice. These results are discussed in context of the effects that sociality has on the magnitude of responses to adverse associative stimuli and an involvement of specific elements of brain circuitry in mediating these effects.

text: Social interaction affects acquisition of lithium chloride-induced conditioned taste aversion: identification of underlying changes in neuronal activation in key forebrain areas A conditioned taste aversion (CTA) develops when exposure to a novel tastant is followed by sickness/malaise. Recently, it has been shown that a CTA can be reduced if the animal is placed in a social environment, i.e., in the presence of a conspecific, during the CTA acquisition phase. The current project was aimed to expand on our understanding of this phenomenon by (a) identifying the magnitude of an aversive response to a saccharin solution induced by lithium chloride (LiCl), a known emetic agent, in mice maintained in the social versus non-social setting; and (b) defining differences in LiCl-induced neuronal activation in the key CTA-related forebrain areas of animals in the social and non-social scenario. In mice lacking social stimulation, LiCl at a dose of 1 mEq induced a mild CTA to saccharin and the 6-mEq dose produced a profound aversive response. On the other hand, 6 mEq was the lowest effective dose in mice kept in the social setting. Immunohistochemical analysis of a neuronal activity marker, c-Fos, showed that alteration of activity in the paraventricular nucleus of the hypothalamus (PVN) and central nucleus of the amygdala (CEA) is associated with the observed changes. In LiCl-injected mice subjected to social stimulation, also the percentage of Fos-positive oxytocin (OT), but not vasopressin neurons in the PVN was higher than in LiCl-treated single-housed mice. These results are discussed in context of the effects that sociality has on the magnitude of responses to adverse associative stimuli and an involvement of specific elements of brain circuitry in mediating these effects.

year: 2016

title: Developing community and social psychology for Aotearoa: Experiences from a New Zealand programme of indigenization

authors: Thomas, David R.

subjects: indigenous psychology

abstract: Experiences related to developing an indigenous community and social psychology
in the teaching of psychology at the University of Waikato in Aotearoa/New Zealand
are described. The process of localization emphasizes the need to interpret
"universal" concepts in terms of local cultural patterns and to elaborate psychological
concepts derived from the cultures of indigenous peoples. The localization of
psychology in New Zealand involves: (a) differences between the dominant United
States cultural pattern, in which much English-language psychology is embedded,
and New Zealand cultural patterns; and (b) differences between the dominant
Pakeha (Anglo-New Zealander) cultural patterns and the cultural patterns of
indigenous Maori peoples. These cultural differences involve contrasts between
individualistic and collective conceptions of self-identities and social identities, and
alternative conceptions of community needs.
Three processes relevant to localization are outlined: socio-cultural contextualization,
agenda-setting, and knowledge of cultural styles. Socio-cultural contextualization
refers to the relevance of psychological knowledge, taught in dominant national
institutions, to local social, cultural and political systems. Agenda-setting focuses on
how the dominant themes in teaching and research within psychology are selected,
and the relevance of these themes to community needs. Knowledge of local cultural
styles is required to describe and teach professional roles that are congruent with
such cultural styles.

text: Developing community and social psychology for Aotearoa: Experiences from a New Zealand programme of indigenization Experiences related to developing an indigenous community and social psychology
in the teaching of psychology at the University of Waikato in Aotearoa/New Zealand
are described. The process of localization emphasizes the need to interpret
"universal" concepts in terms of local cultural patterns and to elaborate psychological
concepts derived from the cultures of indigenous peoples. The localization of
psychology in New Zealand involves: (a) differences between the dominant United
States cultural pattern, in which much English-language psychology is embedded,
and New Zealand cultural patterns; and (b) differences between the dominant
Pakeha (Anglo-New Zealander) cultural patterns and the cultural patterns of
indigenous Maori peoples. These cultural differences involve contrasts between
individualistic and collective conceptions of self-identities and social identities, and
alternative conceptions of community needs.
Three processes relevant to localization are outlined: socio-cultural contextualization,
agenda-setting, and knowledge of cultural styles. Socio-cultural contextualization
refers to the relevance of psychological knowledge, taught in dominant national
institutions, to local social, cultural and political systems. Agenda-setting focuses on
how the dominant themes in teaching and research within psychology are selected,
and the relevance of these themes to community needs. Knowledge of local cultural
styles is required to describe and teach professional roles that are congruent with
such cultural styles.

year: 1994-08