title: Gene expression underlying ferret hair growth initiation induced by melatonin and modified by steroids

authors: Yu, Zhidong

abstract: Synchronised ferret winter pelage development induced by melatonin was utilised as an in vivo model for studying gene expression associated with the hair growth cycle.
The effects of melatonin and steroids on hair follicle growth initiation in flank skin samples were monitored by histology and immunocytochemistry. Melatonin implantation initiated hair growth within 10 days. Exogenous steroids delivered by slow-release subcutaneous implants had mainly inhibitory effects on spontaneous and melatonin-initiated hair growth, either when given simultaneously or prior to melatonin administration. 17β-oestradiol totally suppressed hair follicle growth in all circumstances, while the inhibitory effects of dexamethasone, testosterone and deoxycorticosterone were weaker and attenuated by melatonin. Progesterone given simultaneously with melatonin inhibited hair growth in males, but did not significantly affect female hair growth initiated by melatonin.

Gene expression underlying ferret hair growth was studied using an optimised differential display technique using two sets of complementary skin samples covering all growth initiation stages. The differential display band patterns for approximately 8% of all skin transcripts suggested that more than a thousand genes are required for hair follicle growth. Of the differentially expressed genes detected in a set of flank skin samples covering all proanagen stages, up to a half are likely to be specifically associated with hair growth.

The 150 expressed sequence tags (ESTs) discovered represented 112 unique sequences. Forty-two of these were aligned by sequence homology to known genes, while the remainder are likely to represent novel genes. Differential expression through the follicle growth cycle or after the treatments was confirmed for 21 out of 23 genes whose mRNAs were detectable by Northern blot hybridisation. Overall, expression alteration for most of these ESTs occurred prior to morphological changes in the skin associated with hair follicle reactivation. All the ESTs whose expression sites were detected by in situ hybridisation were localised to hair follicles. Some were detected only in certain stages of the hair follicle cycle, others in all growth stages, but at different levels. Classification of the identified ESTs suggested that apoptosis as well as fatty acid synthesis and cholesterol metabolism were closely associated with hair growth initiation, while cell interaction and motility were also particular prominent processes in hair follicle regrowth.

Additional DNA sequence information was obtained for ferret hair acidic keratin 8 (fHa8) and ferret cyclin D-interacting myb-like protein 1 (fDMP1). Both of these genes were expressed only in cortical cells in the keratogenous zone from mid-proanagen. fHa8 was expressed only in one side of the cortex, a feature has not previously been reported for other type I intermediate hair keratins. The restricted expression of fDMP1 and its smaller size suggested that it was an alternatively spliced form of the human and mouse homologues with a specialised function in the regulation of cortical cell proliferation and differentiation. Further studies on the expression regulation and function of the genes represented by the ESTs identified in this study promise to considerably advance our understanding of hair follicle growth control.

text: Gene expression underlying ferret hair growth initiation induced by melatonin and modified by steroids Synchronised ferret winter pelage development induced by melatonin was utilised as an in vivo model for studying gene expression associated with the hair growth cycle.
The effects of melatonin and steroids on hair follicle growth initiation in flank skin samples were monitored by histology and immunocytochemistry. Melatonin implantation initiated hair growth within 10 days. Exogenous steroids delivered by slow-release subcutaneous implants had mainly inhibitory effects on spontaneous and melatonin-initiated hair growth, either when given simultaneously or prior to melatonin administration. 17β-oestradiol totally suppressed hair follicle growth in all circumstances, while the inhibitory effects of dexamethasone, testosterone and deoxycorticosterone were weaker and attenuated by melatonin. Progesterone given simultaneously with melatonin inhibited hair growth in males, but did not significantly affect female hair growth initiated by melatonin.

Gene expression underlying ferret hair growth was studied using an optimised differential display technique using two sets of complementary skin samples covering all growth initiation stages. The differential display band patterns for approximately 8% of all skin transcripts suggested that more than a thousand genes are required for hair follicle growth. Of the differentially expressed genes detected in a set of flank skin samples covering all proanagen stages, up to a half are likely to be specifically associated with hair growth.

The 150 expressed sequence tags (ESTs) discovered represented 112 unique sequences. Forty-two of these were aligned by sequence homology to known genes, while the remainder are likely to represent novel genes. Differential expression through the follicle growth cycle or after the treatments was confirmed for 21 out of 23 genes whose mRNAs were detectable by Northern blot hybridisation. Overall, expression alteration for most of these ESTs occurred prior to morphological changes in the skin associated with hair follicle reactivation. All the ESTs whose expression sites were detected by in situ hybridisation were localised to hair follicles. Some were detected only in certain stages of the hair follicle cycle, others in all growth stages, but at different levels. Classification of the identified ESTs suggested that apoptosis as well as fatty acid synthesis and cholesterol metabolism were closely associated with hair growth initiation, while cell interaction and motility were also particular prominent processes in hair follicle regrowth.

Additional DNA sequence information was obtained for ferret hair acidic keratin 8 (fHa8) and ferret cyclin D-interacting myb-like protein 1 (fDMP1). Both of these genes were expressed only in cortical cells in the keratogenous zone from mid-proanagen. fHa8 was expressed only in one side of the cortex, a feature has not previously been reported for other type I intermediate hair keratins. The restricted expression of fDMP1 and its smaller size suggested that it was an alternatively spliced form of the human and mouse homologues with a specialised function in the regulation of cortical cell proliferation and differentiation. Further studies on the expression regulation and function of the genes represented by the ESTs identified in this study promise to considerably advance our understanding of hair follicle growth control.

year: 2001

title: Feature extractor stacking for cross-domain few-shot learning

authors: Wang, Hongyu

subjects: computer science

abstract: Cross-domain few-shot learning (CDFSL) addresses learning problems where knowledge needs to be transferred from one or more source domains into an instance-scarce target domain with an explicitly different distribution. Recently published CDFSL methods generally construct a universal model that combines knowledge of multiple source domains into one feature extractor. This enables efficient inference but necessitates re-computation of the extractor whenever a new source domain is added. Some of these methods are also incompatible with heterogeneous source domain extractor architectures. We propose feature extractor stacking (FES), a new CDFSL method for combining information from a collection of extractors, that can utilise heterogeneous pretrained extractors out of the box and does not maintain a universal model that needs to be re-computed when its extractor collection is updated. We present the basic FES algorithm, which is inspired by the classic stacked generalisation approach, and also introduce two variants: convolutional FES (ConFES) and regularised FES (ReFES). Given a target-domain task, these algorithms fine-tune each extractor independently, use cross-validation to extract training data for stacked generalisation from the support set, and learn a simple linear stacking classifier from this data. We evaluate our FES methods on the well-known Meta-Dataset benchmark, targeting image classification with convolutional neural networks, and show that they can achieve state-of-the-art performance.

text: Feature extractor stacking for cross-domain few-shot learning Cross-domain few-shot learning (CDFSL) addresses learning problems where knowledge needs to be transferred from one or more source domains into an instance-scarce target domain with an explicitly different distribution. Recently published CDFSL methods generally construct a universal model that combines knowledge of multiple source domains into one feature extractor. This enables efficient inference but necessitates re-computation of the extractor whenever a new source domain is added. Some of these methods are also incompatible with heterogeneous source domain extractor architectures. We propose feature extractor stacking (FES), a new CDFSL method for combining information from a collection of extractors, that can utilise heterogeneous pretrained extractors out of the box and does not maintain a universal model that needs to be re-computed when its extractor collection is updated. We present the basic FES algorithm, which is inspired by the classic stacked generalisation approach, and also introduce two variants: convolutional FES (ConFES) and regularised FES (ReFES). Given a target-domain task, these algorithms fine-tune each extractor independently, use cross-validation to extract training data for stacked generalisation from the support set, and learn a simple linear stacking classifier from this data. We evaluate our FES methods on the well-known Meta-Dataset benchmark, targeting image classification with convolutional neural networks, and show that they can achieve state-of-the-art performance.

year: 2023-11-30

title: Whānau Stories: Creating meaningful engagement and wellbeing for the indigenous culture of Aotearoa New Zealand

authors: Cruse, Diana Caroline Annavale

subjects: Engagement

abstract: This research sees my interests coalesce into a particular focus on how collaborative partnerships with parents/caregivers can provide whānau Māori with opportunities to strengthen wellbeing in their own lives. It is located in Aotearoa New Zealand and within the context of Te Whāriki (Ministry of Education, 1996), Aotearoa New Zealand’s early childhood curriculum.  The Ministry of Education has a target that 98% of all children in Aotearoa New Zealand under 5 will attend an early childhood education setting (Ministry of Education, 2016), with Māori children having lower participation rates than the national participation rate (Ministry of Education, 2013).  The premise for this thesis is that meaningful whānau engagement in early learning contexts within Aotearoa New Zealand can empower whānau Māori, and honour the promises made in Te Tiriti o Waitangi of partnership, participation, and protection.
Therefore, this thesis sets out to examine what constitutes meaningful engagement for whānau Māori in an early childhood setting in Aotearoa New Zealand, and how meaningful engagement can assist whānau to enjoy an increase of wellbeing.
To explore this issue, I conducted research within an early childhood setting in Aotearoa New Zealand, using methodologies of Kaupapa Māori Research and Narrative Inquiry.  I listened to the narratives of whānau Māori indicating how meaningful engagement was created for them, and investigated if links were generated between engagement and wellbeing for their whānau. These links were identified in the literature as significant levers for educational success.
This research discovered three stages of engagement for the whānau Māori who participated in this study: establishing engagement, developing engagement and solidifying engagement.  Once created, meaningful engagement can lead to flourishing, indicating that there is relationship between meaningful engagement and whānau wellbeing.

text: Whānau Stories: Creating meaningful engagement and wellbeing for the indigenous culture of Aotearoa New Zealand This research sees my interests coalesce into a particular focus on how collaborative partnerships with parents/caregivers can provide whānau Māori with opportunities to strengthen wellbeing in their own lives. It is located in Aotearoa New Zealand and within the context of Te Whāriki (Ministry of Education, 1996), Aotearoa New Zealand’s early childhood curriculum.  The Ministry of Education has a target that 98% of all children in Aotearoa New Zealand under 5 will attend an early childhood education setting (Ministry of Education, 2016), with Māori children having lower participation rates than the national participation rate (Ministry of Education, 2013).  The premise for this thesis is that meaningful whānau engagement in early learning contexts within Aotearoa New Zealand can empower whānau Māori, and honour the promises made in Te Tiriti o Waitangi of partnership, participation, and protection.
Therefore, this thesis sets out to examine what constitutes meaningful engagement for whānau Māori in an early childhood setting in Aotearoa New Zealand, and how meaningful engagement can assist whānau to enjoy an increase of wellbeing.
To explore this issue, I conducted research within an early childhood setting in Aotearoa New Zealand, using methodologies of Kaupapa Māori Research and Narrative Inquiry.  I listened to the narratives of whānau Māori indicating how meaningful engagement was created for them, and investigated if links were generated between engagement and wellbeing for their whānau. These links were identified in the literature as significant levers for educational success.
This research discovered three stages of engagement for the whānau Māori who participated in this study: establishing engagement, developing engagement and solidifying engagement.  Once created, meaningful engagement can lead to flourishing, indicating that there is relationship between meaningful engagement and whānau wellbeing.

year: 2017