title: Population genetic structure of New Zealand's endemic corophiid amphipods: evidence for allopatric speciation

authors: Stevens, Mark I.

subjects: allozyme

abstract: Allozyme electrophoresis was used to examine population genetic structure at inter- and intraspecific levels for the New Zealand endemic corophiid amphipods, Paracorophium lucasi and P. excavatum. Individuals were collected from estuarine and freshwater habitats from North, South and Chatham Islands. Analyses of genetic structure among interspecific populations indicated clear allelic differentiation between the two Paracorophium species (Nei's genetic distance, D = 1.62), as well as considerable intraspecific substructuring (D = 0.15–0.65). These levels of divergence are similar to interspecific levels for other amphipods and it is proposed that at least two groups from the P. lucasi complex and three from the P. excavatum complex correspond to sibling species. In most cases allopatry can account for the differentiation among the putative sibling species. For populations that share a common coastline we found low levels of differentiation and little or no correlation with geographical distance, suggesting that gene flow is adequate to maintain homogeneous population genetic structure. By contrast, populations on separate coastlines (i.e. isolated by land) showed moderate levels of geographical differentiation indicating restricted gene flow. The juxtaposition of population genetic and biogeographical data for Paracorophium in conjunction with the geological record infers past histories of glacial extirpation, and possible isolating effects of sea-level and landmass changes that have occurred throughout the Plio-Pleistocene.

text: Population genetic structure of New Zealand's endemic corophiid amphipods: evidence for allopatric speciation Allozyme electrophoresis was used to examine population genetic structure at inter- and intraspecific levels for the New Zealand endemic corophiid amphipods, Paracorophium lucasi and P. excavatum. Individuals were collected from estuarine and freshwater habitats from North, South and Chatham Islands. Analyses of genetic structure among interspecific populations indicated clear allelic differentiation between the two Paracorophium species (Nei's genetic distance, D = 1.62), as well as considerable intraspecific substructuring (D = 0.15–0.65). These levels of divergence are similar to interspecific levels for other amphipods and it is proposed that at least two groups from the P. lucasi complex and three from the P. excavatum complex correspond to sibling species. In most cases allopatry can account for the differentiation among the putative sibling species. For populations that share a common coastline we found low levels of differentiation and little or no correlation with geographical distance, suggesting that gene flow is adequate to maintain homogeneous population genetic structure. By contrast, populations on separate coastlines (i.e. isolated by land) showed moderate levels of geographical differentiation indicating restricted gene flow. The juxtaposition of population genetic and biogeographical data for Paracorophium in conjunction with the geological record infers past histories of glacial extirpation, and possible isolating effects of sea-level and landmass changes that have occurred throughout the Plio-Pleistocene.

year: 2004

title: Who goes to a sexual health clinic? Gender differences in service utilisation.

authors: Morgan, Jane

subjects: sexual health

abstract: Aim: Our aim was to review utilisation of the Hamilton Sexual Health Clinic
(Hamilton, Waikato, New Zealand) with regard to gender differences.
Methods: Notes of those attending during 9 months (1 February 2008–31 October
2008) were reviewed—and their demographic details, source of referral, reasons for
attending, and diagnostic coding data were compared. In addition, Waikato Hospital
laboratory provided Chlamydia trachomatis test results for the study period. Data was
analysed for gender differences.
Results: Overall, more women attended than men. By age bands, more 15–19 year old
women than men attended (23.3% vs 12.5%, p<0.001) but, for all age-bands 20 years
and older, men were at least as likely to attend as women. Further, for those aged 25–
29 years (20.3% vs 17%, p<0.5) and 45 years and older (11.9% vs 7.4%, p<0.001),
more men than women of the same-age band were seen. Men who attended were
more likely to self-refer (58.5% vs 43%, p<0.001) and less likely to be asymptomatic
(30.3% vs 38.4%, p<0.001).
Conclusions: Our data suggest men aged 20 years and older are at least, if not more,
likely than women to attend a sexual health clinic for sexual health concerns.
However, there appears to be under-utilisation by younger men. To improve sexual
health for men and women, help-seeking must be timely and effective. We need to
better understand and address sexual healthcare barriers for young men.

text: Who goes to a sexual health clinic? Gender differences in service utilisation. Aim: Our aim was to review utilisation of the Hamilton Sexual Health Clinic
(Hamilton, Waikato, New Zealand) with regard to gender differences.
Methods: Notes of those attending during 9 months (1 February 2008–31 October
2008) were reviewed—and their demographic details, source of referral, reasons for
attending, and diagnostic coding data were compared. In addition, Waikato Hospital
laboratory provided Chlamydia trachomatis test results for the study period. Data was
analysed for gender differences.
Results: Overall, more women attended than men. By age bands, more 15–19 year old
women than men attended (23.3% vs 12.5%, p<0.001) but, for all age-bands 20 years
and older, men were at least as likely to attend as women. Further, for those aged 25–
29 years (20.3% vs 17%, p<0.5) and 45 years and older (11.9% vs 7.4%, p<0.001),
more men than women of the same-age band were seen. Men who attended were
more likely to self-refer (58.5% vs 43%, p<0.001) and less likely to be asymptomatic
(30.3% vs 38.4%, p<0.001).
Conclusions: Our data suggest men aged 20 years and older are at least, if not more,
likely than women to attend a sexual health clinic for sexual health concerns.
However, there appears to be under-utilisation by younger men. To improve sexual
health for men and women, help-seeking must be timely and effective. We need to
better understand and address sexual healthcare barriers for young men.

year: 2008-12

title: Does artificial intelligence modelling have anything to offer traditional management of freshwater food resources?

authors: Death, Russell G.

abstract: Management of freshwater systems and the ecosystem services they provide has become a multi-stakeholder activity. This requires information on resources and how to manage them to be disseminated to a wide range of users. While artificial intelligence modelling can provide a powerful tool in managing and understanding resources and their drivers, they can be confusing to many users. In this study, we explored the potential use of two alternative modelling approaches (Boosted Regression Trees (BRT) and Bayesian Belief Networks (BBN)) for managing three species of freshwater mahinga kai species-kākahi or kaeo (freshwater mussel), koura (freshwater crayfish) and tuna (freshwater eel). While the BBN model I sbetter for stakeholder communication, the BRT produced more accurate models for all species. However, variables identified as being important for predicting abundance and biomass of these species were often environmental parameters that cannot be managed to improve yield. The artificial intelligence modelling does provide some accurate linkages between the target species and their environmental drivers. Nevertheless, translating these relationships into management plans remains challenging. The models are clearly not a panacea for better resource management, but provide one more tool that might assist multi-stakeholder understanding of how best to manage freshwater resources.

text: Does artificial intelligence modelling have anything to offer traditional management of freshwater food resources? Management of freshwater systems and the ecosystem services they provide has become a multi-stakeholder activity. This requires information on resources and how to manage them to be disseminated to a wide range of users. While artificial intelligence modelling can provide a powerful tool in managing and understanding resources and their drivers, they can be confusing to many users. In this study, we explored the potential use of two alternative modelling approaches (Boosted Regression Trees (BRT) and Bayesian Belief Networks (BBN)) for managing three species of freshwater mahinga kai species-kākahi or kaeo (freshwater mussel), koura (freshwater crayfish) and tuna (freshwater eel). While the BBN model I sbetter for stakeholder communication, the BRT produced more accurate models for all species. However, variables identified as being important for predicting abundance and biomass of these species were often environmental parameters that cannot be managed to improve yield. The artificial intelligence modelling does provide some accurate linkages between the target species and their environmental drivers. Nevertheless, translating these relationships into management plans remains challenging. The models are clearly not a panacea for better resource management, but provide one more tool that might assist multi-stakeholder understanding of how best to manage freshwater resources.

year: 2017