title: Enacted stigma, mental health, and protective factors among transgender youth in Canada

authors: Veale, Jaimie

subjects: adolescence

abstract: Purpose: We aimed to assess the Minority Stress Model which proposes that the stress of experiencing stigma leads to adverse mental health outcomes, but social supports (e.g., school and family connectedness) will reduce this negative effect.

Methods: We measured stigma-related experiences, social supports, and mental health (self-injury, suicide, depression, and anxiety) among a sample of 923 Canadian transgender 14- to 25-year-old adolescents and young adults using a bilingual online survey. Logistic regression models were conducted to analyze the relationship between these risk and protective factors and dichotomous mental health outcomes among two separate age groups, 14- to 18-year-old and 19- to 25-year-old participants.

Results: Experiences of discrimination, harassment, and violence (enacted stigma) were positively related to mental health problems and social support was negatively associated with mental health problems in all models among both age groups. Among 14–18 year olds, we examined school connectedness, family connectedness, and perception of friends caring separately, and family connectedness was always the strongest protective predictor in multivariate models. In all the mental health outcomes we examined, transgender youth reporting low levels of enacted stigma experiences and high levels of protective factors tended to report favorable mental health outcomes. Conversely, the majority of participants reporting high levels of enacted stigma and low levels of protective factors reported adverse mental health outcomes.

Conclusion: While these findings are limited by nonprobability sampling procedures and potential additional unmeasured risk and protective factors, the results provide positive evidence for the Minority Stress Model in this population and affirm the need for policies and programs to support schools and families to support transgender youth.

text: Enacted stigma, mental health, and protective factors among transgender youth in Canada Purpose: We aimed to assess the Minority Stress Model which proposes that the stress of experiencing stigma leads to adverse mental health outcomes, but social supports (e.g., school and family connectedness) will reduce this negative effect.

Methods: We measured stigma-related experiences, social supports, and mental health (self-injury, suicide, depression, and anxiety) among a sample of 923 Canadian transgender 14- to 25-year-old adolescents and young adults using a bilingual online survey. Logistic regression models were conducted to analyze the relationship between these risk and protective factors and dichotomous mental health outcomes among two separate age groups, 14- to 18-year-old and 19- to 25-year-old participants.

Results: Experiences of discrimination, harassment, and violence (enacted stigma) were positively related to mental health problems and social support was negatively associated with mental health problems in all models among both age groups. Among 14–18 year olds, we examined school connectedness, family connectedness, and perception of friends caring separately, and family connectedness was always the strongest protective predictor in multivariate models. In all the mental health outcomes we examined, transgender youth reporting low levels of enacted stigma experiences and high levels of protective factors tended to report favorable mental health outcomes. Conversely, the majority of participants reporting high levels of enacted stigma and low levels of protective factors reported adverse mental health outcomes.

Conclusion: While these findings are limited by nonprobability sampling procedures and potential additional unmeasured risk and protective factors, the results provide positive evidence for the Minority Stress Model in this population and affirm the need for policies and programs to support schools and families to support transgender youth.

year: 2017

title: Synthesis, Microstructure and Mechanical Properties of Titanium with Controlled Levels of Porosity

authors: Xu, Qian

subjects: Titanium

abstract: Porous titanium (Ti) products have many applications due to their excellent corrosion resistance, high strength-to-weight ratio, high specific surface area, etc. However, the major limitation is the expensive cost of porous Ti products because of the high raw materials costs and the difficulty of processing. The novelty of this research work is concerned with a study of a ceramic casting technique, slip casting, to create porous Ti products and the effect of porosity on the mechanical properties and gas permeability of Ti compacts. 

An optimised Ti slurry was developed from 43 vol.% of Ti powder, 0.3 dw.% of dispersant, 0.8 dw.% of plasticiser and 0.8 dw.% of binder, mixed with a balance of distilled water, which produced a viscosity of 290 cP. It was then poured into a plaster mould to form compacts with a green density of 45%. Thermal debinding was carried out at 320°C with an argon flow for 2 hours, followed by vacuum sintering different samples at 1000°C and 1200°C for 0.5 hours, respectively. The porous sintered compacts had satisfactory tensile strength with some plastic deformation. The increase in oxygen and carbon content during processing was minor. The results from this investigation suggested that slip casting is a potentially low-cost, simple manufacturing route for porous Ti products.

Porous Ti compacts with porosity in the range of 12.3 vol.% to 35.3 vol.% were fabricated by slip casting. The mechanical properties, fracture morphology, gas permeability, pore size analysis and pore shape factors for the porous Ti compacts were determined for different porosity levels. A decreasing porosity level resulted in less open porosity and gas permeability, reduced pore size, and an increased tensile stress and elongation. The mechanical properties of porous Ti compacts produced by slip casting were comparable with more conventional press and sintered materials at the same porosity levels. Theoretical models for tensile stress and ductility as a function of porosity were examined and incorporated into the results and differences between the theoretical models and experimental results are discussed. The pore shape factor analysis showed that tensile loading would stretch the pores in the compacts to produce more irregular pores, which were acting as linkage sites to allow the propagation of cracks. Additionally, a novel interconnected pore characterisation method using ammonium meta-tungstate solution is presented. By using backscatter scanning electron microscopy, the interconnected pores can be directly observed. 

The packing behaviour and sintering behaviour of Ti compacts fabricated with different particles size distribution were characterised and studied, in terms of porosity, pore size analysis, tensile properties and gas permeability. Two different particles size (avg. 14 μm & avg. 56 μm) of pure Ti hydride-dehydride powder were used in five volume proportions (20:80, 40:60, 60:40, 80:20 & 100:0). A theoretical model predicted that the green density reaches a maximum when the volume fraction of fine particles is 0.35. It was found that although experimental results showed similar behaviour there was no well-defined maximum green density. The sintered compacts showed that an increase in the volume fraction of fine powder particles reduced the porosity, permeability level and pore size, and increased the tensile properties. The relationship between permeability and porosity level was non-linear and this was caused by the differences in pore diameters in the compacts. The capillary tube model was used to discuss the relationship between the permeability, pore diameter and porosity. Using this information, a graded porosity compact was designed and fabricated by slip casting. A future study on this graded porosity compacts is recommended to undertake in more depth.

text: Synthesis, Microstructure and Mechanical Properties of Titanium with Controlled Levels of Porosity Porous titanium (Ti) products have many applications due to their excellent corrosion resistance, high strength-to-weight ratio, high specific surface area, etc. However, the major limitation is the expensive cost of porous Ti products because of the high raw materials costs and the difficulty of processing. The novelty of this research work is concerned with a study of a ceramic casting technique, slip casting, to create porous Ti products and the effect of porosity on the mechanical properties and gas permeability of Ti compacts. 

An optimised Ti slurry was developed from 43 vol.% of Ti powder, 0.3 dw.% of dispersant, 0.8 dw.% of plasticiser and 0.8 dw.% of binder, mixed with a balance of distilled water, which produced a viscosity of 290 cP. It was then poured into a plaster mould to form compacts with a green density of 45%. Thermal debinding was carried out at 320°C with an argon flow for 2 hours, followed by vacuum sintering different samples at 1000°C and 1200°C for 0.5 hours, respectively. The porous sintered compacts had satisfactory tensile strength with some plastic deformation. The increase in oxygen and carbon content during processing was minor. The results from this investigation suggested that slip casting is a potentially low-cost, simple manufacturing route for porous Ti products.

Porous Ti compacts with porosity in the range of 12.3 vol.% to 35.3 vol.% were fabricated by slip casting. The mechanical properties, fracture morphology, gas permeability, pore size analysis and pore shape factors for the porous Ti compacts were determined for different porosity levels. A decreasing porosity level resulted in less open porosity and gas permeability, reduced pore size, and an increased tensile stress and elongation. The mechanical properties of porous Ti compacts produced by slip casting were comparable with more conventional press and sintered materials at the same porosity levels. Theoretical models for tensile stress and ductility as a function of porosity were examined and incorporated into the results and differences between the theoretical models and experimental results are discussed. The pore shape factor analysis showed that tensile loading would stretch the pores in the compacts to produce more irregular pores, which were acting as linkage sites to allow the propagation of cracks. Additionally, a novel interconnected pore characterisation method using ammonium meta-tungstate solution is presented. By using backscatter scanning electron microscopy, the interconnected pores can be directly observed. 

The packing behaviour and sintering behaviour of Ti compacts fabricated with different particles size distribution were characterised and studied, in terms of porosity, pore size analysis, tensile properties and gas permeability. Two different particles size (avg. 14 μm & avg. 56 μm) of pure Ti hydride-dehydride powder were used in five volume proportions (20:80, 40:60, 60:40, 80:20 & 100:0). A theoretical model predicted that the green density reaches a maximum when the volume fraction of fine particles is 0.35. It was found that although experimental results showed similar behaviour there was no well-defined maximum green density. The sintered compacts showed that an increase in the volume fraction of fine powder particles reduced the porosity, permeability level and pore size, and increased the tensile properties. The relationship between permeability and porosity level was non-linear and this was caused by the differences in pore diameters in the compacts. The capillary tube model was used to discuss the relationship between the permeability, pore diameter and porosity. Using this information, a graded porosity compact was designed and fabricated by slip casting. A future study on this graded porosity compacts is recommended to undertake in more depth.

year: 2014

title: Na Tarimo i whakaari... Ko Rangiwewehi te iwi

authors: Flavell, James William Ben

abstract: Ko ngā kōrero e whai ake nei, he mea kohikohi, he mea tuku mai ki ahau mō te iwi e kiia nei, ko Ngāti Rangiwewehi. Ko te rohe ki te taha raki o te Rotorua-nui-ā-kahumatamomoe to tūrangawaewae, otirā the rohe takahi o te iwi nei, i ngā rā o mua, nā, ahakoa he nui te whenua kua ngaro atu, kei konei tonu te papa kāinga mō tēnei karangatanga o Te Arawa waka, kei konei hoki tōna mauri, tōna mana, tōna wehi.
Ko Ngāti Rangiwehei i ēnei rā, e rite tonu ana ki te tōtara nui. I tipu ake tēnei tōtara i te kākano i ruia i Rangiātea arā, i Hawaiki, i mānu mai ki Aotearoa nei, i puāwai mai, ā, kei te tipu tonu, kei te tuipu tonu.
Nā, kei roto i tēnei rākau, ko ngā kōrero katoa mō te iwi nei, arā ko ngā whakapapa, ko ngā waiata ko ngā karakia, ko ngā pakiwaitara otirā ko ngā āhuatanga katoa e pā ana ki te iwi. Kei konei hoki ko te ira o te tangata e mau nei i ēnei āhuatanga nei.
Ka tae ki te ngahuru, ka heke iho ngā rau rākau ka pirau, ka ngaro. Pēnei i te rākau nei, te hinga te tangata, ka kapohia e te ringa o Aituā, ā, ka ngaro. Ēhara i te mea ko te mauri o te tangata anake te mea e ngaro nei, ēngari, ko ōna mātauranga katoa hoki.
Nā, matemate noa atu ngā koroua me ngākuia e mōhio tūturu ana ki ngā kōrero hōhonu tuku iho a Ngāti Rangiwewehi. Nō reira, ko tāku mahi, he kohi i ēnei kōrero, i mua i te ngaronga tonutanga o ngā kaumātua e ora ana, nei ngaro.
Kua kohia nei e au ngā kōrero katoa ahakoa Māori ahakoa Pākehā, kia kitea ai, kia mārama ake ai ngā momo āhuatanga o tōku iwi.
Ēhara tēnei i te me ngāwari, nō te mea, ko tēnei mea te mātaranga ahakoa he whakapapa rānei, he pakiwaitara rānei, he mea tino tapu ki te Māori, i te ao tawhito, ā, kei te pērā anō hoki i ēnei rā. Kua oti te tārai te tāhū o tēnei tuhituhinga e kore a taea te whakatārewa tēnei tāhū mehemea kāore, ōna pou kāore ōna here e tika ana. Otirā e kore e tū te whare kōreo, te tāhū whakaringa kōereo, mehemea kāore ōna kaupapa whenua, tangata, tae atu ki a Papatūānuku. Nō reira, koia tēnei ka tātaihia ake ngā kupu kōreroa muri ake nei, kia tutuki ai ngā tūmanako ngā wawata, a ngā whakatipuranga, mai, mai, mai i te pō ki ngā kaikōrero me te kaituhi.
E ai ki te iwi, ko Rangiwewehi te tipuna o tēnei iwi te tamaiti a Tawakeheimoa rāua ko Te Aongahoro.
Nā te mea, he karangatanga a Ngāti Rangiwewehi nō Te Arawa waka i hoki atu ai au ki ngā kōrero mō tēnei waka tapu. Tae rawa mai tēnei waka ki tēnei whenua, ka horapa hāere ngā tāngata i te mata o te whenua. I tōna wā, i tae atu ngā tīpuna ke Te Awahou awa, otirā ki te taha raki o Rotorua moana. Mai i taua wā, ka tīmata ngā āhuatanga katoa e pā ana ki tēnei iwi.
Nā, ēhara tēnei tuhinga i te pukapuka hei whakaatu i te tūturutanga o ngā kōrero katoa o Ngāti Rangiwewehi, mā Ngāti Rangiwewehi hei whai atu, ēngari he kōrero kua kohia nei e au i ngā rangatira, i ngā tohunga, i ngā tāngata mōhio, i ngā whāea, i ngā kaumātua me ngā pukapuka a ngā Māori me ngā Pākehā.
He pūtake kōrero noa iho tēnei mō Ngāti Rangiwewehi he tohu whakamaharatanga hoki ki ngā tīpuna, ki ngā mātua kua wehe atu nei ki te pō.

text: Na Tarimo i whakaari... Ko Rangiwewehi te iwi Ko ngā kōrero e whai ake nei, he mea kohikohi, he mea tuku mai ki ahau mō te iwi e kiia nei, ko Ngāti Rangiwewehi. Ko te rohe ki te taha raki o te Rotorua-nui-ā-kahumatamomoe to tūrangawaewae, otirā the rohe takahi o te iwi nei, i ngā rā o mua, nā, ahakoa he nui te whenua kua ngaro atu, kei konei tonu te papa kāinga mō tēnei karangatanga o Te Arawa waka, kei konei hoki tōna mauri, tōna mana, tōna wehi.
Ko Ngāti Rangiwehei i ēnei rā, e rite tonu ana ki te tōtara nui. I tipu ake tēnei tōtara i te kākano i ruia i Rangiātea arā, i Hawaiki, i mānu mai ki Aotearoa nei, i puāwai mai, ā, kei te tipu tonu, kei te tuipu tonu.
Nā, kei roto i tēnei rākau, ko ngā kōrero katoa mō te iwi nei, arā ko ngā whakapapa, ko ngā waiata ko ngā karakia, ko ngā pakiwaitara otirā ko ngā āhuatanga katoa e pā ana ki te iwi. Kei konei hoki ko te ira o te tangata e mau nei i ēnei āhuatanga nei.
Ka tae ki te ngahuru, ka heke iho ngā rau rākau ka pirau, ka ngaro. Pēnei i te rākau nei, te hinga te tangata, ka kapohia e te ringa o Aituā, ā, ka ngaro. Ēhara i te mea ko te mauri o te tangata anake te mea e ngaro nei, ēngari, ko ōna mātauranga katoa hoki.
Nā, matemate noa atu ngā koroua me ngākuia e mōhio tūturu ana ki ngā kōrero hōhonu tuku iho a Ngāti Rangiwewehi. Nō reira, ko tāku mahi, he kohi i ēnei kōrero, i mua i te ngaronga tonutanga o ngā kaumātua e ora ana, nei ngaro.
Kua kohia nei e au ngā kōrero katoa ahakoa Māori ahakoa Pākehā, kia kitea ai, kia mārama ake ai ngā momo āhuatanga o tōku iwi.
Ēhara tēnei i te me ngāwari, nō te mea, ko tēnei mea te mātaranga ahakoa he whakapapa rānei, he pakiwaitara rānei, he mea tino tapu ki te Māori, i te ao tawhito, ā, kei te pērā anō hoki i ēnei rā. Kua oti te tārai te tāhū o tēnei tuhituhinga e kore a taea te whakatārewa tēnei tāhū mehemea kāore, ōna pou kāore ōna here e tika ana. Otirā e kore e tū te whare kōreo, te tāhū whakaringa kōereo, mehemea kāore ōna kaupapa whenua, tangata, tae atu ki a Papatūānuku. Nō reira, koia tēnei ka tātaihia ake ngā kupu kōreroa muri ake nei, kia tutuki ai ngā tūmanako ngā wawata, a ngā whakatipuranga, mai, mai, mai i te pō ki ngā kaikōrero me te kaituhi.
E ai ki te iwi, ko Rangiwewehi te tipuna o tēnei iwi te tamaiti a Tawakeheimoa rāua ko Te Aongahoro.
Nā te mea, he karangatanga a Ngāti Rangiwewehi nō Te Arawa waka i hoki atu ai au ki ngā kōrero mō tēnei waka tapu. Tae rawa mai tēnei waka ki tēnei whenua, ka horapa hāere ngā tāngata i te mata o te whenua. I tōna wā, i tae atu ngā tīpuna ke Te Awahou awa, otirā ki te taha raki o Rotorua moana. Mai i taua wā, ka tīmata ngā āhuatanga katoa e pā ana ki tēnei iwi.
Nā, ēhara tēnei tuhinga i te pukapuka hei whakaatu i te tūturutanga o ngā kōrero katoa o Ngāti Rangiwewehi, mā Ngāti Rangiwewehi hei whai atu, ēngari he kōrero kua kohia nei e au i ngā rangatira, i ngā tohunga, i ngā tāngata mōhio, i ngā whāea, i ngā kaumātua me ngā pukapuka a ngā Māori me ngā Pākehā.
He pūtake kōrero noa iho tēnei mō Ngāti Rangiwewehi he tohu whakamaharatanga hoki ki ngā tīpuna, ki ngā mātua kua wehe atu nei ki te pō.

year: 1986