title: Insensitivity to anorexigenic effects of naltrexone in the VPA rat model of autism

authors: Bray, Jonathon Edward

subjects: Naltrexone

abstract: Autism spectrum disorder (ASD) is a complex disorder whose etiology lies in, among others, abnormal neural processing, and improper neural circuitry development. This results in a plethora of aberrant behaviors, including those driven by the brain’s reward system and by the endogenous mediators of reward, for example opioids. One of the maladaptive consequences of pathophysiology of the reward system is excessive consumption of palatable foods in people with autism and in ASD model animals, such as valproic acid (VPA)-induced ASD rats. Here, I hypothesized that overconsumption of palatable diets in the VPA ASD rat is caused by abnormal functioning of the opioid circuitry. To investigate this, first I determined sensitivity of sucrose liquid-fed or high?fat high-sugar chow (HFHS)-fed VPA vs non-VPA control rats to the anorexigenic properties of the opioid receptor antagonist, naltrexone (NTX), a drug that reduces eating for palatability, but does not affect feeding for calories. In the follow up immunohistochemical study involving a marker of neuronal activity, c-Fos, I examined differences in brain activation after an injection of the same dose of NTX in VPAs vs non-VPA controls. As expected, NTX did not affect energy-driven consumption of bland chow in non-VPA controls or VPAs. NTX did, however, decrease intake of palatable sucrose water and HFHS chow. Importantly, while 1 mg/kg NTX was sufficient to reduce eating for palatability in non-VPA controls, a 10-mg NTX dose was needed to achieve the same effect in VPAs. c-Fos analysis in the non–VPA controls showed significant differences in neuronal activation in the paraventricular nucleus (PVN), supraoptic nucleus (SON), arcuate nucleus (ARC), Dorsomedial hypothalamus (DMH), central nucleus of the amygdala (CeA), and nucleus accumbens shell (NAc – shell). The VPA animals showed a difference only in the CeA. Collectively these data show different responsiveness to NTX at the behavioural (feeding) and brain activation iii (c-Fos) level, likely indicative of dysregulation of the opioid signaling and – more broadly – reward processing, in the autistic brain.

text: Insensitivity to anorexigenic effects of naltrexone in the VPA rat model of autism Autism spectrum disorder (ASD) is a complex disorder whose etiology lies in, among others, abnormal neural processing, and improper neural circuitry development. This results in a plethora of aberrant behaviors, including those driven by the brain’s reward system and by the endogenous mediators of reward, for example opioids. One of the maladaptive consequences of pathophysiology of the reward system is excessive consumption of palatable foods in people with autism and in ASD model animals, such as valproic acid (VPA)-induced ASD rats. Here, I hypothesized that overconsumption of palatable diets in the VPA ASD rat is caused by abnormal functioning of the opioid circuitry. To investigate this, first I determined sensitivity of sucrose liquid-fed or high?fat high-sugar chow (HFHS)-fed VPA vs non-VPA control rats to the anorexigenic properties of the opioid receptor antagonist, naltrexone (NTX), a drug that reduces eating for palatability, but does not affect feeding for calories. In the follow up immunohistochemical study involving a marker of neuronal activity, c-Fos, I examined differences in brain activation after an injection of the same dose of NTX in VPAs vs non-VPA controls. As expected, NTX did not affect energy-driven consumption of bland chow in non-VPA controls or VPAs. NTX did, however, decrease intake of palatable sucrose water and HFHS chow. Importantly, while 1 mg/kg NTX was sufficient to reduce eating for palatability in non-VPA controls, a 10-mg NTX dose was needed to achieve the same effect in VPAs. c-Fos analysis in the non–VPA controls showed significant differences in neuronal activation in the paraventricular nucleus (PVN), supraoptic nucleus (SON), arcuate nucleus (ARC), Dorsomedial hypothalamus (DMH), central nucleus of the amygdala (CeA), and nucleus accumbens shell (NAc – shell). The VPA animals showed a difference only in the CeA. Collectively these data show different responsiveness to NTX at the behavioural (feeding) and brain activation iii (c-Fos) level, likely indicative of dysregulation of the opioid signaling and – more broadly – reward processing, in the autistic brain.

year: 2022

title: Identifying music documents in a collection of images

authors: Bainbridge, David

subjects: computer science

abstract: Digital libraries and search engines are now well-equipped to find images of documents based on queries. Many images of music scores are now available, often mixed up with textual documents and images. For example, using the Google “images” search feature, a  search for “Beethoven” will return a number of scores and manuscripts as well as pictures of the composer. In this paper we report on an investigation into methods to mechanically determine if a particular document is indeed a score, so that the user can specify that only musical scores should be returned. The goal is to find a minimal set of features that can be used as a quick test that will be applied to large numbers of documents.
A variety of filters were considered, and two promising ones (run-length ratios and Hough transform) were evaluated. We found that a method based around run-lengths in vertical scans (RL) that out-performs a comparable algorithm using the Hough transform (HT). On a test set of 1030 images, RL achieved recall and precision of 97.8% and 88.4% respectively while HT achieved 97.8% and 73.5%. In terms of processor time, RL was more than five times as fast as HT.

text: Identifying music documents in a collection of images Digital libraries and search engines are now well-equipped to find images of documents based on queries. Many images of music scores are now available, often mixed up with textual documents and images. For example, using the Google “images” search feature, a  search for “Beethoven” will return a number of scores and manuscripts as well as pictures of the composer. In this paper we report on an investigation into methods to mechanically determine if a particular document is indeed a score, so that the user can specify that only musical scores should be returned. The goal is to find a minimal set of features that can be used as a quick test that will be applied to large numbers of documents.
A variety of filters were considered, and two promising ones (run-length ratios and Hough transform) were evaluated. We found that a method based around run-lengths in vertical scans (RL) that out-performs a comparable algorithm using the Hough transform (HT). On a test set of 1030 images, RL achieved recall and precision of 97.8% and 88.4% respectively while HT achieved 97.8% and 73.5%. In terms of processor time, RL was more than five times as fast as HT.

year: 2006

title: Tino rangatiratanga in health policies and practises

authors: Wihongi, Helen Annette

subjects: tino rangatiratanga

abstract: The purpose of my doctoral research was to investigate tino rangatiratanga in health policies and practises in Aotearoa. My research involved defining tino rangatiratanga and exploring the expression of tino rangatiratanga in health policy and practises. A kaupapa Māori analysis of the 1996 National Cervical Screening Programme’s Policy document was at the core of the policy investigation. The analysis involved developing a kaupapa Māori analysing framework and then analysing the 1996 National Cervical Screening Policy document for empirical and normative judgements at four discursive levels, health gains, health objectives, health goals and fundamental underlying values. A Kaupapa Māori research design drew on interdisciplinary scholarship on colonisation, Te Tiriti o Waitangi, community psychology, public policy, disability theory, feminist theory and discourse theory.

I argue that the dominance of Western cultural norms and state-directed policies were made possible by the signing of Te Tiriti o Waitangi. The signing of Te Tiriti saw Crown sovereignty being implemented and tino rangatiratanga ignored. The consequences for Māori have been disastrous with loss of land and economic base which has resulted in poor health status. I also argue that tino rangatiratanga has the potential to transform the social and political context that frame Aotearoa society. Such an approach raises a critical dilemma for the state as meaningful recognition of tino rangatiratanga requires waiving full and absolute sovereignty which currently resides in the state. Hence some scholars argue that tino rangatiratanga is a site for constructive engagement where state and Māori relationships can be renegotiated. The extent to which this potential for constructive engagement is being realised in however is inadequately explored in the scholarly literature. Exploring the relationships between tino rangatiratanga and health policies and practises as undertaken in my thesis will therefore contribute to scholarly knowledge on the subject.

The findings from the research show that tino rangatiratanga is indeed a complex, fluid, multi-faceted and context related concept. Within the context of my research, tino rangatiratanga is defined as Māori sovereignty, self determination, and positive Māori development. As a Māori value it is about mana and tapu of rangatira or leadership personified. Within policies, tino rangatiratanga has emerged through resistance and demonstration and is actualised through Tiriti legislation and policies.

The legitimation of tino rangatiratanga in cervical screening services sees Māori leadership at national, regional and local levels and Māori involvement through wide ranging consultation but the Crown still controls the policy process and therefore the outcomes. Most cervical screening services are still owned and operated by the Crown or Crown agencies.

One of the consequences of Crown control is that Māori women are still twice as likely to get cervical cancer and four times more likely to die from it. To some degree this may be the result of resource allocation and the result of discriminatory service practices but also the result of resistance to the procedure itself.

Tino rangatiratanga within cervical screening services could be strengthened through iwi ownership of some cervical screening register sites. At the time of my field work (2000) there were 14 sites, all owned and operated by Crown agents. Tino rangatiratanga could also be strengthened through funding criteria that ensure practitioners are safe to practise, through the adoption of less invasive procedures and through the legitimation of Māori healing practises such as rongoā and karakia.

Overall if tino rangatiratanga is to be given full effect within the policy domain Māori must have a well established asset base, they must be in control of the decision making making process including resource allocation, service delivery must address the diversities of Māori realities and Māori must be the recipients of policy decisions made.

text: Tino rangatiratanga in health policies and practises The purpose of my doctoral research was to investigate tino rangatiratanga in health policies and practises in Aotearoa. My research involved defining tino rangatiratanga and exploring the expression of tino rangatiratanga in health policy and practises. A kaupapa Māori analysis of the 1996 National Cervical Screening Programme’s Policy document was at the core of the policy investigation. The analysis involved developing a kaupapa Māori analysing framework and then analysing the 1996 National Cervical Screening Policy document for empirical and normative judgements at four discursive levels, health gains, health objectives, health goals and fundamental underlying values. A Kaupapa Māori research design drew on interdisciplinary scholarship on colonisation, Te Tiriti o Waitangi, community psychology, public policy, disability theory, feminist theory and discourse theory.

I argue that the dominance of Western cultural norms and state-directed policies were made possible by the signing of Te Tiriti o Waitangi. The signing of Te Tiriti saw Crown sovereignty being implemented and tino rangatiratanga ignored. The consequences for Māori have been disastrous with loss of land and economic base which has resulted in poor health status. I also argue that tino rangatiratanga has the potential to transform the social and political context that frame Aotearoa society. Such an approach raises a critical dilemma for the state as meaningful recognition of tino rangatiratanga requires waiving full and absolute sovereignty which currently resides in the state. Hence some scholars argue that tino rangatiratanga is a site for constructive engagement where state and Māori relationships can be renegotiated. The extent to which this potential for constructive engagement is being realised in however is inadequately explored in the scholarly literature. Exploring the relationships between tino rangatiratanga and health policies and practises as undertaken in my thesis will therefore contribute to scholarly knowledge on the subject.

The findings from the research show that tino rangatiratanga is indeed a complex, fluid, multi-faceted and context related concept. Within the context of my research, tino rangatiratanga is defined as Māori sovereignty, self determination, and positive Māori development. As a Māori value it is about mana and tapu of rangatira or leadership personified. Within policies, tino rangatiratanga has emerged through resistance and demonstration and is actualised through Tiriti legislation and policies.

The legitimation of tino rangatiratanga in cervical screening services sees Māori leadership at national, regional and local levels and Māori involvement through wide ranging consultation but the Crown still controls the policy process and therefore the outcomes. Most cervical screening services are still owned and operated by the Crown or Crown agencies.

One of the consequences of Crown control is that Māori women are still twice as likely to get cervical cancer and four times more likely to die from it. To some degree this may be the result of resource allocation and the result of discriminatory service practices but also the result of resistance to the procedure itself.

Tino rangatiratanga within cervical screening services could be strengthened through iwi ownership of some cervical screening register sites. At the time of my field work (2000) there were 14 sites, all owned and operated by Crown agents. Tino rangatiratanga could also be strengthened through funding criteria that ensure practitioners are safe to practise, through the adoption of less invasive procedures and through the legitimation of Māori healing practises such as rongoā and karakia.

Overall if tino rangatiratanga is to be given full effect within the policy domain Māori must have a well established asset base, they must be in control of the decision making making process including resource allocation, service delivery must address the diversities of Māori realities and Māori must be the recipients of policy decisions made.

year: 2010