title: The effect of santicipatory behaviours, generated by Pavlovian conditioning, on the development of play in early and normally weaned rats.

authors: Guadarrama-Maillot, Veronica

subjects: Rattus norvegicus

abstract: Since the classic studies of Pavlov, a wide variety of researchers have investigated the
process of classical conditioning and used it to investigate animal behaviour.
Recently, researchers in animal behaviour have discovered important new benefits
associated with classical conditioning, now being applied as a way of enhancing
 well-being . Pavlovian conditioning occurs when an association between two
stimuli, a neutral stimulus and a biologically relevant stimulus, is created by repeated
paired presentations of both stimuli. When the presentation of the neutral stimulus is
followed by a delay, before the biological stimulus is presented,  expectation  or
 anticipatory behaviour  is generated. Anticipatory behaviour is known to elicit the
release of dopamine. As play behaviour is also known to result in the release of
dopamine, and correlates with positive welfare state, studies of the relationship
between anticipatory behaviour and play may generate important new insights for
animal welfare.
In this study I assessed if (i) early weaning influenced the development of playful
attacks and  pinning  behaviour in rats and (ii) the effects of a Pavlovian conditioning
paradigm on the occurrence of play in both early - and normally - weaned rats. Male
pups were assigned to one of the following treatment groups: (1) an early weaned
(EW) group without exposure to conditioning, (2) a normally weaned (NW) group
without exposure to conditioning, (3) an EW group with a conditional stimulus (CS)
paired to an unconditional stimulus (US) to generate anticipatory behaviour (CS-US),
(4) an EW group with CS-US unpaired, (5) an EW group with US only and (6) a NW
group with US only. Animals in each group were observed for one hour each week
from 4 to 7 weeks of life to record the frequency of playful attacks and pinning
behaviour. EW pups that were not exposed to any form of conditioning had a
significant reduction in the frequency of playful attacks relative to the NW pups
without conditioning; pinning frequencies were low, but the effect was not
statistically significant. The difference in frequencies of playful attacks between the
NW group without exposure to conditioning and all the EW groups was statistically
significant, with the NW groups displaying the highest frequencies of playful
behaviour; pinning changes across those same treatment groups were not significant.
Interestingly, the EW group under Pavlovian conditioning had a higher mean
frequency of playful attacks and pinning behaviour relative to the EW control groups
(i.e. EW with CS-US unpaired and EW with US only). Eliciting anticipatory
behaviour may explain the increased levels of play behaviour in the EW conditioned
group. Weight increases were similar across all EW and NW groups.
The results of this study are discussed in relation to the effects that early weaning has
on behavioural development, the potential benefits of using anticipatory behaviour to
reduce the impacts of stressful events, and its positive effects in the development of
play behaviour in rats. The findings support the idea that a Pavlovian conditioning
paradigm can be used to enhance the welfare of animals and that the expectation for
the reward has a greater effect than the reward itself.

text: The effect of santicipatory behaviours, generated by Pavlovian conditioning, on the development of play in early and normally weaned rats. Since the classic studies of Pavlov, a wide variety of researchers have investigated the
process of classical conditioning and used it to investigate animal behaviour.
Recently, researchers in animal behaviour have discovered important new benefits
associated with classical conditioning, now being applied as a way of enhancing
 well-being . Pavlovian conditioning occurs when an association between two
stimuli, a neutral stimulus and a biologically relevant stimulus, is created by repeated
paired presentations of both stimuli. When the presentation of the neutral stimulus is
followed by a delay, before the biological stimulus is presented,  expectation  or
 anticipatory behaviour  is generated. Anticipatory behaviour is known to elicit the
release of dopamine. As play behaviour is also known to result in the release of
dopamine, and correlates with positive welfare state, studies of the relationship
between anticipatory behaviour and play may generate important new insights for
animal welfare.
In this study I assessed if (i) early weaning influenced the development of playful
attacks and  pinning  behaviour in rats and (ii) the effects of a Pavlovian conditioning
paradigm on the occurrence of play in both early - and normally - weaned rats. Male
pups were assigned to one of the following treatment groups: (1) an early weaned
(EW) group without exposure to conditioning, (2) a normally weaned (NW) group
without exposure to conditioning, (3) an EW group with a conditional stimulus (CS)
paired to an unconditional stimulus (US) to generate anticipatory behaviour (CS-US),
(4) an EW group with CS-US unpaired, (5) an EW group with US only and (6) a NW
group with US only. Animals in each group were observed for one hour each week
from 4 to 7 weeks of life to record the frequency of playful attacks and pinning
behaviour. EW pups that were not exposed to any form of conditioning had a
significant reduction in the frequency of playful attacks relative to the NW pups
without conditioning; pinning frequencies were low, but the effect was not
statistically significant. The difference in frequencies of playful attacks between the
NW group without exposure to conditioning and all the EW groups was statistically
significant, with the NW groups displaying the highest frequencies of playful
behaviour; pinning changes across those same treatment groups were not significant.
Interestingly, the EW group under Pavlovian conditioning had a higher mean
frequency of playful attacks and pinning behaviour relative to the EW control groups
(i.e. EW with CS-US unpaired and EW with US only). Eliciting anticipatory
behaviour may explain the increased levels of play behaviour in the EW conditioned
group. Weight increases were similar across all EW and NW groups.
The results of this study are discussed in relation to the effects that early weaning has
on behavioural development, the potential benefits of using anticipatory behaviour to
reduce the impacts of stressful events, and its positive effects in the development of
play behaviour in rats. The findings support the idea that a Pavlovian conditioning
paradigm can be used to enhance the welfare of animals and that the expectation for
the reward has a greater effect than the reward itself.

year: 2009

title: Interpretation of Contracts: Development and Trend of Common Law Approach (合同解释之普通法——方法、演进及趋势）

authors: Liao, Zhixiong (Leo)

subjects: Contract interpretation

abstract: A thorough analysis of the history, development and trend of the Common Law Approach in interpretation of contracts.

text: Interpretation of Contracts: Development and Trend of Common Law Approach (合同解释之普通法——方法、演进及趋势） A thorough analysis of the history, development and trend of the Common Law Approach in interpretation of contracts.

year: 2017

title: The 2020 cannabis referendum: Māori voter support, racialized policing, and the Criminal Justice System

authors: Dempster, Craig

abstract: In the New Zealand 2020 cannabis referendum, 50.7% of all voters rejected the creation of a legally-regulated cannabis market and instead supported retaining the current prohibitionist policy. Although the referendum failed to pass, a majority of Māori voted in favor of cannabis law reform. This paper suggests that within the Māori community there is a more nuanced appreciation of the impact of policing cannabis. Māori perceive that greater harm is caused by the racialized policing of cannabis than by the usage of it. Following McCreanor, et al. (2014), this paper employs a thematic, content analysis of the New Zealand Herald’s coverage of the 2020 cannabis referendum to investigate the presence of race-based targeting/policing in discussions of the legislation. The results reveal that racial disparities emerged as secondary to framing both the impact of cannabis and the referendum as race-neutral and affecting everyone in society equally. This paper argues that the impact of the policing of this particular drug impacts Māori differently, wherein they bear the brunt of racialized policing. Thus, Māori possess a more sophisticated understanding that warrants consideration because it is inextricably linked to lived experiences of policing that differ from wider social narratives of policing and drug policy in New Zealand.

text: The 2020 cannabis referendum: Māori voter support, racialized policing, and the Criminal Justice System In the New Zealand 2020 cannabis referendum, 50.7% of all voters rejected the creation of a legally-regulated cannabis market and instead supported retaining the current prohibitionist policy. Although the referendum failed to pass, a majority of Māori voted in favor of cannabis law reform. This paper suggests that within the Māori community there is a more nuanced appreciation of the impact of policing cannabis. Māori perceive that greater harm is caused by the racialized policing of cannabis than by the usage of it. Following McCreanor, et al. (2014), this paper employs a thematic, content analysis of the New Zealand Herald’s coverage of the 2020 cannabis referendum to investigate the presence of race-based targeting/policing in discussions of the legislation. The results reveal that racial disparities emerged as secondary to framing both the impact of cannabis and the referendum as race-neutral and affecting everyone in society equally. This paper argues that the impact of the policing of this particular drug impacts Māori differently, wherein they bear the brunt of racialized policing. Thus, Māori possess a more sophisticated understanding that warrants consideration because it is inextricably linked to lived experiences of policing that differ from wider social narratives of policing and drug policy in New Zealand.

year: 2022