title: Data refinement and singleton failures refinement are not equivalent

authors: Reeves, Steve

subjects: data refinement

abstract: In this paper, we give simple example abstract data types, with atomic operations, that are related by data refinement under a definition used widely in the literature, but these same abstract data types are not related by singleton failure refinement. This contradicts results found in the literature.

text: Data refinement and singleton failures refinement are not equivalent In this paper, we give simple example abstract data types, with atomic operations, that are related by data refinement under a definition used widely in the literature, but these same abstract data types are not related by singleton failure refinement. This contradicts results found in the literature.

year: 2008

title: The mating systems and introgression of New Zealand fishing spiders (Dolomedes)

authors: Connolly, Simon

subjects: Behaviour

abstract: Mating systems describe the number of mates different sexes in a species have in their lifetime. Mating systems are key to sexual selection and the evolution of species, as a mating system sets the rules for future evolution and sexual conflict. Spiders show a wide variety of mating systems and extreme adaptations and behaviours are associated with the evolution of monogynous (males mate once in their life) mating systems, including males breaking their genitalia and sacrificing themselves to be eaten by their mate.

Another process that is highly influential on evolution is introgression, the movement of genes from one species to another. This generally occurs through species mating to produce hybrids which then facilitate gene transfer. Despite requiring two different species to interbreed, introgression is often not investigated through the lens of mating behaviours and how these can facilitate or limit introgression.

Dolomedes aquaticus and D. minor are fishing spiders endemic to New Zealand. Their mating systems and behaviour are undescribed, but members of this genus in other parts of the world are known for their extreme mating behaviour including obligate monogyny, spontaneous male death and sexual cannibalism. Previous genomic work on D. aquaticus and D. minor revealed a one-way and geographically limited introgression occurring between the two species. That is, genes are being transferred between the two species, but only via D. aquaticus females mating with D. minor males; and only in the extreme south of the two species’ shared range.

In this thesis I investigated the mating systems and introgression of D. aquaticus and D. minor, using laboratory experiments, field surveys, and 3D morphometrics. I found D. aquaticus females will generally only mate once, followed by a syndrome of aggression after mating, whilst males will mate multiply. D. minor mating is typified by low probability of mating for males and females, but potential for multiple mating in both sexes, rapid escape behaviour by males following copulation, and genital damage. I also found that the two species are able to meet outside of the Introgression Zone, making it unlikely that habitat plays a key role in the introgression. Instead, my results suggest behaviour plays a significant role in limiting the introgression, with male-choice controlling the geographic element and female-choice the one-way element. Using micro-computed tomography and 3D morphometrics I analysed the potential role of genital shape in this introgression. Whilst the genitalia of the two species were quantifiably different, there was little evidence that genital shape limits the introgression. 

The results of this thesis show that closely related species can have drastically different mating systems, showing the strong impact sexual selection can have on the behaviour of species. They also highlight the importance of behaviour to promoting and limiting introgression between species. Future work on these species should include investigation of sperm dynamics, the rapid copulation behaviour of D. minor, and testing the effectiveness of genital plugging to reduce sperm competition in D. minor.

text: The mating systems and introgression of New Zealand fishing spiders (Dolomedes) Mating systems describe the number of mates different sexes in a species have in their lifetime. Mating systems are key to sexual selection and the evolution of species, as a mating system sets the rules for future evolution and sexual conflict. Spiders show a wide variety of mating systems and extreme adaptations and behaviours are associated with the evolution of monogynous (males mate once in their life) mating systems, including males breaking their genitalia and sacrificing themselves to be eaten by their mate.

Another process that is highly influential on evolution is introgression, the movement of genes from one species to another. This generally occurs through species mating to produce hybrids which then facilitate gene transfer. Despite requiring two different species to interbreed, introgression is often not investigated through the lens of mating behaviours and how these can facilitate or limit introgression.

Dolomedes aquaticus and D. minor are fishing spiders endemic to New Zealand. Their mating systems and behaviour are undescribed, but members of this genus in other parts of the world are known for their extreme mating behaviour including obligate monogyny, spontaneous male death and sexual cannibalism. Previous genomic work on D. aquaticus and D. minor revealed a one-way and geographically limited introgression occurring between the two species. That is, genes are being transferred between the two species, but only via D. aquaticus females mating with D. minor males; and only in the extreme south of the two species’ shared range.

In this thesis I investigated the mating systems and introgression of D. aquaticus and D. minor, using laboratory experiments, field surveys, and 3D morphometrics. I found D. aquaticus females will generally only mate once, followed by a syndrome of aggression after mating, whilst males will mate multiply. D. minor mating is typified by low probability of mating for males and females, but potential for multiple mating in both sexes, rapid escape behaviour by males following copulation, and genital damage. I also found that the two species are able to meet outside of the Introgression Zone, making it unlikely that habitat plays a key role in the introgression. Instead, my results suggest behaviour plays a significant role in limiting the introgression, with male-choice controlling the geographic element and female-choice the one-way element. Using micro-computed tomography and 3D morphometrics I analysed the potential role of genital shape in this introgression. Whilst the genitalia of the two species were quantifiably different, there was little evidence that genital shape limits the introgression. 

The results of this thesis show that closely related species can have drastically different mating systems, showing the strong impact sexual selection can have on the behaviour of species. They also highlight the importance of behaviour to promoting and limiting introgression between species. Future work on these species should include investigation of sperm dynamics, the rapid copulation behaviour of D. minor, and testing the effectiveness of genital plugging to reduce sperm competition in D. minor.

year: 2024

title: Does within-treatment change on dynamic risk factors and psychopathology predict recidivism for men graduating from Tai Aroha?

authors: Tanner Dempsey, Arden

subjects: dynamic risk factors

abstract: Dynamic risk factors are modifiable aspects of justice-involved people and their environment that can change over time and are associated with criminal behaviour. Because they are considered changeable, they are therefore typically the focus of rehabilitative treatment (Bonta & Andrews, 2024). Research shows that correctional rehabilitation that targets dynamic risk factors effectively reduces recidivism, and psychometric tools assessing these factors generally show improvements during treatment. However, there is a missing link; current research lacks consistent evidence linking changes on dynamic risk factors during treatment to recidivism. Relatedly, there are few studies assessing within-treatment changes in psychopathology and how they may affect recidivism, though they are commonly assessed alongside dynamic risk factors in correctional settings. 
This study, involving 164 people with violent offence convictions who completed the Tai Aroha community treatment programme, aimed to address this missing link. A battery of tests measured pre- and post-programme included dynamic risk factor measures, the Anger Disorders Scale (ADS), Psychological Inventory of Criminal Thinking Styles (PICTS), Criminal Attitudes to Violence Scale (CAVS), and the Millon Clinical Multiaxial Inventory (MCMI-III and IV) which is designed to assess personality and clinical psychopathology. Standardised residual change scores were used to account for variance in pre-treatment scores, and Cox regression hazard ratios to test prediction of general and violent recidivism.
Most subscales for dynamic risk factor measures and the MCMI-III and IV showed substantial improvements during treatment, however, this did not translate to predicting the probability of recidivism. While several hazard ratios indicated effects in a positive direction, none were significant when adjusted for multiple comparisons, and controlling for actuarial risk did not improve predictive accuracy. There was some evidence of increased socially desirable responding which increased at the end of treatment, this included responses on the MCMI-III and IV consistent with the “Normal Quartet.” Interpretations of these findings and both theoretical and empirical implications are discussed.

text: Does within-treatment change on dynamic risk factors and psychopathology predict recidivism for men graduating from Tai Aroha? Dynamic risk factors are modifiable aspects of justice-involved people and their environment that can change over time and are associated with criminal behaviour. Because they are considered changeable, they are therefore typically the focus of rehabilitative treatment (Bonta & Andrews, 2024). Research shows that correctional rehabilitation that targets dynamic risk factors effectively reduces recidivism, and psychometric tools assessing these factors generally show improvements during treatment. However, there is a missing link; current research lacks consistent evidence linking changes on dynamic risk factors during treatment to recidivism. Relatedly, there are few studies assessing within-treatment changes in psychopathology and how they may affect recidivism, though they are commonly assessed alongside dynamic risk factors in correctional settings. 
This study, involving 164 people with violent offence convictions who completed the Tai Aroha community treatment programme, aimed to address this missing link. A battery of tests measured pre- and post-programme included dynamic risk factor measures, the Anger Disorders Scale (ADS), Psychological Inventory of Criminal Thinking Styles (PICTS), Criminal Attitudes to Violence Scale (CAVS), and the Millon Clinical Multiaxial Inventory (MCMI-III and IV) which is designed to assess personality and clinical psychopathology. Standardised residual change scores were used to account for variance in pre-treatment scores, and Cox regression hazard ratios to test prediction of general and violent recidivism.
Most subscales for dynamic risk factor measures and the MCMI-III and IV showed substantial improvements during treatment, however, this did not translate to predicting the probability of recidivism. While several hazard ratios indicated effects in a positive direction, none were significant when adjusted for multiple comparisons, and controlling for actuarial risk did not improve predictive accuracy. There was some evidence of increased socially desirable responding which increased at the end of treatment, this included responses on the MCMI-III and IV consistent with the “Normal Quartet.” Interpretations of these findings and both theoretical and empirical implications are discussed.

year: 2024-01-23