title: Multiculturalism and women’s employment: A sociological perspective

authors: Foroutan, Yaghoob

abstract: This paper analyses the patterns and determinants of female labour force participation from a sociological perspective. Using a relatively recent database, the present analysis updates existing knowledge and evaluates prior research regarding the market employment of women, particularly in the multiethnic and multicultural context. The analysis is based on research conducted in Australia, where there is a  substantial proportion of European-ancestry populations. The article  also provides some cross national comparisons with other multicultural settings. The results of this paper are based on logistic regression analysis. The results suggest that human capital and family formation appear to play as the most fundamental determinants in women's market employment. The results also suggest that while native-born women are generally more benefited in the labour market, the native-foreigner differentials regarding the employment patterns and determinants tend to be mainly associated with ethnic origin and length of residence in the destination country.

text: Multiculturalism and women’s employment: A sociological perspective This paper analyses the patterns and determinants of female labour force participation from a sociological perspective. Using a relatively recent database, the present analysis updates existing knowledge and evaluates prior research regarding the market employment of women, particularly in the multiethnic and multicultural context. The analysis is based on research conducted in Australia, where there is a  substantial proportion of European-ancestry populations. The article  also provides some cross national comparisons with other multicultural settings. The results of this paper are based on logistic regression analysis. The results suggest that human capital and family formation appear to play as the most fundamental determinants in women's market employment. The results also suggest that while native-born women are generally more benefited in the labour market, the native-foreigner differentials regarding the employment patterns and determinants tend to be mainly associated with ethnic origin and length of residence in the destination country.

year: 2011

title: Field and laboratory investigations of Echyridella menziesii (Unionida: Hyriidae) interactions with host fishes

authors: Hanrahan, Nicole Joy

subjects: freshwater mussel

abstract: Globally, the study of freshwater mussels has increased markedly in recent years, spurred on by recognition that many mussel populations are declining or are already extinct. The New Zealand freshwater mussel Echyridella menziesii (Unionida: Hyriidae) has a current threat classification of ‘At Risk, Declining’, in part reflecting disruption of recruitment on host fish. The life cycle of E. menziesii includes a parasitic stage in which the larvae (glochidia) must attach to a host fish to transform into the juvenile stage. However, no research has been conducted to understand whether fish develop immunity that limits infestation rates, and little is known about the spatial and temporal variations of mussel-host interactions in natural environments in New Zealand. This study therefore aimed to: i) determine whether multiple infestations of E. menziesii glochidia influenced the suitability of common bully (Gobiomorphus cotidianus) as a host; and ii) quantify fish host associations over the glochidial release period in three contrasting Waikato streams.

Common bully considered naïve to E. menziesii were infested with glochidia in the laboratory, and placed in individual, flow-through tanks (22oC) which were flushed every second day to measure glochidia detachment and juvenile excystment. Fishes were infested either one, two or three times, with ‘control’ fish infested for the first time in the second and third rounds. There were no differences in cumulative detachment rates of glochidia and no major reductions in metamorphosis success across multiple infestations. 

Metamorphosis success rate across all infestation rounds was ≤30%, and was highest when initial glochidia viability was also high. The lack of detectable immunity in common bully, at least after three sequential infestations, is promising for the future conservation of E. menziesii as host-fish are likely to be repetitively infested with glochidia over the mussel spawning season in a natural setting.

Infestation by glochidia was determined on the associated fish community, caught using a combination of electrofishing and minnow trapping. In parallel with these evaluations, mussel brood pouch development was assessed fortnightly from October 2018 to February 2019 at three Waikato stream sites. Peak glochidia release occurred in February when average monthly water temperatures were >18.8oC. A field method was developed to quantify glochidial attachment on external surfaces of fish, while internal attachment (gills, mouth) was quantified by laboratory dissection. While a range of fish hosts were identified, 86% of recorded glochidia were attached to Gobiomorphus species, including redfin bully (G. huttoni) and common/Crans bully (G. cotidianus/G. basalis). Most externally-attached glochidia (73%) occurred on caudal, pelvic and pectoral fins. Host associations appeared to favour benthic rather than pelagic species, and did not change throughout the mussel reproductive season despite seasonal change in fish communities.

This research demonstrates that common bully, and more broadly Gobiomorphus species, are important hosts for glochidia and do not develop immunity to repeated infestations. Gobiomorphus species have the potential to be very useful ‘tools’ to assist in restoring E. menziesii populations, and therefore conservation management must consider these host fish populations as well as other habitat and water quality factors affecting E. menziesii.

text: Field and laboratory investigations of Echyridella menziesii (Unionida: Hyriidae) interactions with host fishes Globally, the study of freshwater mussels has increased markedly in recent years, spurred on by recognition that many mussel populations are declining or are already extinct. The New Zealand freshwater mussel Echyridella menziesii (Unionida: Hyriidae) has a current threat classification of ‘At Risk, Declining’, in part reflecting disruption of recruitment on host fish. The life cycle of E. menziesii includes a parasitic stage in which the larvae (glochidia) must attach to a host fish to transform into the juvenile stage. However, no research has been conducted to understand whether fish develop immunity that limits infestation rates, and little is known about the spatial and temporal variations of mussel-host interactions in natural environments in New Zealand. This study therefore aimed to: i) determine whether multiple infestations of E. menziesii glochidia influenced the suitability of common bully (Gobiomorphus cotidianus) as a host; and ii) quantify fish host associations over the glochidial release period in three contrasting Waikato streams.

Common bully considered naïve to E. menziesii were infested with glochidia in the laboratory, and placed in individual, flow-through tanks (22oC) which were flushed every second day to measure glochidia detachment and juvenile excystment. Fishes were infested either one, two or three times, with ‘control’ fish infested for the first time in the second and third rounds. There were no differences in cumulative detachment rates of glochidia and no major reductions in metamorphosis success across multiple infestations. 

Metamorphosis success rate across all infestation rounds was ≤30%, and was highest when initial glochidia viability was also high. The lack of detectable immunity in common bully, at least after three sequential infestations, is promising for the future conservation of E. menziesii as host-fish are likely to be repetitively infested with glochidia over the mussel spawning season in a natural setting.

Infestation by glochidia was determined on the associated fish community, caught using a combination of electrofishing and minnow trapping. In parallel with these evaluations, mussel brood pouch development was assessed fortnightly from October 2018 to February 2019 at three Waikato stream sites. Peak glochidia release occurred in February when average monthly water temperatures were >18.8oC. A field method was developed to quantify glochidial attachment on external surfaces of fish, while internal attachment (gills, mouth) was quantified by laboratory dissection. While a range of fish hosts were identified, 86% of recorded glochidia were attached to Gobiomorphus species, including redfin bully (G. huttoni) and common/Crans bully (G. cotidianus/G. basalis). Most externally-attached glochidia (73%) occurred on caudal, pelvic and pectoral fins. Host associations appeared to favour benthic rather than pelagic species, and did not change throughout the mussel reproductive season despite seasonal change in fish communities.

This research demonstrates that common bully, and more broadly Gobiomorphus species, are important hosts for glochidia and do not develop immunity to repeated infestations. Gobiomorphus species have the potential to be very useful ‘tools’ to assist in restoring E. menziesii populations, and therefore conservation management must consider these host fish populations as well as other habitat and water quality factors affecting E. menziesii.

year: 2019

title: In vitro cell culture to study microglial inflammation

authors: Newland, Julia

subjects: CNs

abstract: Inflammation of the central nervous system (CNS) characterised by release of cytokines such as tumour necrosis factor-alpha (TNF-a) and interleukin-1 (IL-1) is an event that is often detrimental to neuronal cells and is thought to contribute to the neuronal loss observed during neurodegeneration.
One objective of this study was to investigate the potential anti-inflammatory properties of kawakawa leaf extracts using in vitro model cell systems. Kawakawa leaf extracts anti-inflammatory properties have anecdotally been documented in traditional Maori medicinal practices (Rangoa). However, before this aspect could be carried out, experiments were undertaken to investigate the effects the kawakawa leaf extracts had on the growth rates of two mammalian cell lines (HeLa and THP-1 cells).
Interestingly, the growth assays showed that the extracts to have both a stimulatory and inhibitory effect on cell growth. Toxicity of cells can be categorised as either necrotic or apoptotic cell death. In this study, HeLa cells and THP-1 cells were incubated under standard growth conditions with various concentrations (10 to 100ug/ml) of Kawakawa leave extracts prepared at room temperature or 60OC.
Growth data as seen in figures 2 and 3 typically have a long lag phase before they start to reach exponential growth between days 4 and 5. The extract having the largest stimulatory effect on HeLa cells as shown by figure 6 was 25 ug/ml at 60OC and the largest inhibitory effect seen on HeLa cells was seen at 50 ug/ml RT shown by figure 6. The extract which has the largest stimulatory effect on THP-1 cells is 25 ug/ml 60OC as shown by figure 11 whereas the extract producing the largest inhibitory effect is 25 ug/ml RT.

Apoptotic and necrotic cell death mechanisms were examined by using in vitro biochemistry techniques. Assessments were largely made based on biochemical changes of HeLa cells and THP-1 cells post treatment of Kawakawa leave extracts.
Measurement of lactate dehydrogenase (LDH assays) in the growth media of cells that were shown to be growth inhibited during exposure to Kawakawa extracts indicated that the growth inhibition resulting from exposure to the extracts was not due to necrotic cell death processes. (ie that cells maintained their membrane integrity) When compared to the control, a lower amount of cytosolic LDH was seen in THP-1 cell lines. However, HeLa cell lines produced a high level of cytosolic LDH which may be due to mycoplasma contamination. On average, Kawakawa concentrations at 12.5ug/ml and 25ug/ml yielded less lysed cells percentage across both cell lines.
The demonstrated cell growth inhibition was unlikely to be due to necrosis and because of this it was decided to see if cell death was caused by mitochondrial processes that would further support apoptotic cell death. The biochemical assay MTT indirectly measures mitochondrial dehydrogenase activity in the presence of kawakawa leave extracts.
The MTT data illustrated mitochondrial impairment where HeLa cells exposed to Kawakawa 60OC concentrations 6.25 ug/ml and 12.5 ug/ml had the lowest average mitochondrial activity. THP-1 cells exposed to Kawakawa 60OC concentrations 12.5 ug/ml and 50 ug/ml had the lowest average mitochondrial activity.
The main results of this study include, the treatment of HeLa and THP-1 cells with kawakawa extracts demonstrated that cytotoxicity was not due to necrosis. The most interesting finding of this study is when kawakawa extracts inhibit cell growth there is no increase in LDH. This is suggestive that the cellular membrane remains intact when exposed to the extract.

text: In vitro cell culture to study microglial inflammation Inflammation of the central nervous system (CNS) characterised by release of cytokines such as tumour necrosis factor-alpha (TNF-a) and interleukin-1 (IL-1) is an event that is often detrimental to neuronal cells and is thought to contribute to the neuronal loss observed during neurodegeneration.
One objective of this study was to investigate the potential anti-inflammatory properties of kawakawa leaf extracts using in vitro model cell systems. Kawakawa leaf extracts anti-inflammatory properties have anecdotally been documented in traditional Maori medicinal practices (Rangoa). However, before this aspect could be carried out, experiments were undertaken to investigate the effects the kawakawa leaf extracts had on the growth rates of two mammalian cell lines (HeLa and THP-1 cells).
Interestingly, the growth assays showed that the extracts to have both a stimulatory and inhibitory effect on cell growth. Toxicity of cells can be categorised as either necrotic or apoptotic cell death. In this study, HeLa cells and THP-1 cells were incubated under standard growth conditions with various concentrations (10 to 100ug/ml) of Kawakawa leave extracts prepared at room temperature or 60OC.
Growth data as seen in figures 2 and 3 typically have a long lag phase before they start to reach exponential growth between days 4 and 5. The extract having the largest stimulatory effect on HeLa cells as shown by figure 6 was 25 ug/ml at 60OC and the largest inhibitory effect seen on HeLa cells was seen at 50 ug/ml RT shown by figure 6. The extract which has the largest stimulatory effect on THP-1 cells is 25 ug/ml 60OC as shown by figure 11 whereas the extract producing the largest inhibitory effect is 25 ug/ml RT.

Apoptotic and necrotic cell death mechanisms were examined by using in vitro biochemistry techniques. Assessments were largely made based on biochemical changes of HeLa cells and THP-1 cells post treatment of Kawakawa leave extracts.
Measurement of lactate dehydrogenase (LDH assays) in the growth media of cells that were shown to be growth inhibited during exposure to Kawakawa extracts indicated that the growth inhibition resulting from exposure to the extracts was not due to necrotic cell death processes. (ie that cells maintained their membrane integrity) When compared to the control, a lower amount of cytosolic LDH was seen in THP-1 cell lines. However, HeLa cell lines produced a high level of cytosolic LDH which may be due to mycoplasma contamination. On average, Kawakawa concentrations at 12.5ug/ml and 25ug/ml yielded less lysed cells percentage across both cell lines.
The demonstrated cell growth inhibition was unlikely to be due to necrosis and because of this it was decided to see if cell death was caused by mitochondrial processes that would further support apoptotic cell death. The biochemical assay MTT indirectly measures mitochondrial dehydrogenase activity in the presence of kawakawa leave extracts.
The MTT data illustrated mitochondrial impairment where HeLa cells exposed to Kawakawa 60OC concentrations 6.25 ug/ml and 12.5 ug/ml had the lowest average mitochondrial activity. THP-1 cells exposed to Kawakawa 60OC concentrations 12.5 ug/ml and 50 ug/ml had the lowest average mitochondrial activity.
The main results of this study include, the treatment of HeLa and THP-1 cells with kawakawa extracts demonstrated that cytotoxicity was not due to necrosis. The most interesting finding of this study is when kawakawa extracts inhibit cell growth there is no increase in LDH. This is suggestive that the cellular membrane remains intact when exposed to the extract.

year: 2016