title: Visual discrimination and object/picture recognition in hens

authors: Railton, Renee Caron Richards

subjects: hens

abstract: Eight experiments were conducted to examine different aspects of hen’s visual behaviour, and to assess whether hens responded to photographs in the same way they do to the real objects that were depicted in the photographs. In Experiment 1, six hens were trained to perform either a conditional discrimination (successive) or forced-choice discrimination (simultaneous) between flickering (25 Hz) and steady lights. A descending method of limits procedure was then used to increase the flicker speed by 5 Hz over blocks of 20 trials until percentages correct decreased below 55%. The critical flicker fusion frequency of hens was found to range between 68.5 and 95.4 Hz (at a luminance of 300 cd/m2). In Experiment 2, hens were trained to discriminate between steady images presented on a TFT screen, and tested for transfer of that discrimination to a CRT monitor at different refresh rates, on which the images were assumed to appear flickering. It was found that hens showed transfer across all refresh rates with coloured stimuli, but that the degree of transfer decreased as refresh rate decreased with stimuli that were discriminable only on shape. In Experiment 3, a similar decrease in accuracy was shown as refresh rate decreased using a range of stimuli. However, hens did not learn to discriminate all stimuli, and thus transfer could not be assessed with some stimuli. Experiment 4, hens were trained with flickering images and showed relatively high transfer to less flickering, or steady, images. In Experiment 5, a procedure was developed to assess whether hens transferred a discrimination of 3D object to 2D photographs of those objects, and vice versa. In Experiment 6, hens were trained to discriminate stimuli of different colours, or of different shapes. The hens learned to discriminate, and transferred this discrimination, with the coloured shapes. The hens also learned to discriminate the same colour (but differently shaped) stimuli, however, further testing showed that an extraneous variables had come to control behaviour. As a result, the equipment was modified for Experiments 7 and 8. In both experiments, only three of the six hens showed discrimination to any degree, and none transferred this discrimination to photographs or objects. It was concluded that hens do not respond to objects depicted in pictures in the same way they do to the real objects. Thus, these experiments show that that animals’ visual systems need to taken into account when visual stimuli are used in research, and researchers first need to establish that animals can see the visual stimuli and that the method of stimulus presentation is species appropriate if images are to be used as representatives of real world stimuli.

text: Visual discrimination and object/picture recognition in hens Eight experiments were conducted to examine different aspects of hen’s visual behaviour, and to assess whether hens responded to photographs in the same way they do to the real objects that were depicted in the photographs. In Experiment 1, six hens were trained to perform either a conditional discrimination (successive) or forced-choice discrimination (simultaneous) between flickering (25 Hz) and steady lights. A descending method of limits procedure was then used to increase the flicker speed by 5 Hz over blocks of 20 trials until percentages correct decreased below 55%. The critical flicker fusion frequency of hens was found to range between 68.5 and 95.4 Hz (at a luminance of 300 cd/m2). In Experiment 2, hens were trained to discriminate between steady images presented on a TFT screen, and tested for transfer of that discrimination to a CRT monitor at different refresh rates, on which the images were assumed to appear flickering. It was found that hens showed transfer across all refresh rates with coloured stimuli, but that the degree of transfer decreased as refresh rate decreased with stimuli that were discriminable only on shape. In Experiment 3, a similar decrease in accuracy was shown as refresh rate decreased using a range of stimuli. However, hens did not learn to discriminate all stimuli, and thus transfer could not be assessed with some stimuli. Experiment 4, hens were trained with flickering images and showed relatively high transfer to less flickering, or steady, images. In Experiment 5, a procedure was developed to assess whether hens transferred a discrimination of 3D object to 2D photographs of those objects, and vice versa. In Experiment 6, hens were trained to discriminate stimuli of different colours, or of different shapes. The hens learned to discriminate, and transferred this discrimination, with the coloured shapes. The hens also learned to discriminate the same colour (but differently shaped) stimuli, however, further testing showed that an extraneous variables had come to control behaviour. As a result, the equipment was modified for Experiments 7 and 8. In both experiments, only three of the six hens showed discrimination to any degree, and none transferred this discrimination to photographs or objects. It was concluded that hens do not respond to objects depicted in pictures in the same way they do to the real objects. Thus, these experiments show that that animals’ visual systems need to taken into account when visual stimuli are used in research, and researchers first need to establish that animals can see the visual stimuli and that the method of stimulus presentation is species appropriate if images are to be used as representatives of real world stimuli.

year: 2011

title: A taxonomy of model-based testing approaches

authors: Utting, Mark

subjects: computer science

abstract: Model-based testing (MBT) relies on models of a system under test and/or its environment to derive test cases for the system. This paper discusses the process of MBT and defines a taxonomy that covers the key aspects of MBT approaches. It is intended to help with understanding the characteristics, similarities and differences of those approaches, and with classifying the approach used in a particular MBT tool. To illustrate the taxonomy, a description of how three different examples of MBT tools fit into the taxonomy is provided.

text: A taxonomy of model-based testing approaches Model-based testing (MBT) relies on models of a system under test and/or its environment to derive test cases for the system. This paper discusses the process of MBT and defines a taxonomy that covers the key aspects of MBT approaches. It is intended to help with understanding the characteristics, similarities and differences of those approaches, and with classifying the approach used in a particular MBT tool. To illustrate the taxonomy, a description of how three different examples of MBT tools fit into the taxonomy is provided.

year: 2012

title: Countering gentrification in Tāmaki Makarau: Towards a framework for urban environmental justice

authors: Terruhn, Jessica

abstract: This policy brief argues for urban policies that actively aim to end gentrification.

Gentrification is intimately tied to state-led processes of urban renewal. Though historically understood as the displacement of low-income households as an unfortunate byproduct of socioeconomic and demographic neighbourhood change, contemporary gentrification is constituted by profit-driven investment decisions that erase undervalued neighbourhoods and their communities in the name of urban renewal (variously referred to as redevelopment, regeneration, renaissance, or revitalisation).

These processes of gentrification fundamentally contribute to environmental injustice. At the same time as creating ‘zones of abundance’, neighbourhood regeneration projects simultaneously (re-)create ‘zones of neglect and sacrifice’, which are burdened with environmental risks. As low-income and ethnic minority households are more likely to either reside in or to be displaced into these neighbourhoods, they are disproportionately exposed to environmental risk factors.

Moreover, gentrification enables and legitimises the exclusion of marginalised communities in multiple ways: 1) it devalues existing places and their residents in favour of regeneration, 2) it displaces longtime residents from regenerated neighbourhoods because of increasing property values, and/or 3) it alienates longtime residents as neighbourhood aesthetics, amenities and services change and become unaffordable and/or irrelevant.

As gentrification contributes to low-income households’ experiences of precarity and severs community ties and place attachments, it generates significant costs to personal and community health and wellbeing as well as social cohesion. The recommendations articulated in this brief emphasise the importance of transformative policy solutions that actively counter gentrification.
These include:
• Equitable investment in urban infrastructure
• Prioritising affordable housing
• Ensuring accessible transportation
• Empowering local communities
• Implementing a Te Tiriti o Waitangi approach to policy development

text: Countering gentrification in Tāmaki Makarau: Towards a framework for urban environmental justice This policy brief argues for urban policies that actively aim to end gentrification.

Gentrification is intimately tied to state-led processes of urban renewal. Though historically understood as the displacement of low-income households as an unfortunate byproduct of socioeconomic and demographic neighbourhood change, contemporary gentrification is constituted by profit-driven investment decisions that erase undervalued neighbourhoods and their communities in the name of urban renewal (variously referred to as redevelopment, regeneration, renaissance, or revitalisation).

These processes of gentrification fundamentally contribute to environmental injustice. At the same time as creating ‘zones of abundance’, neighbourhood regeneration projects simultaneously (re-)create ‘zones of neglect and sacrifice’, which are burdened with environmental risks. As low-income and ethnic minority households are more likely to either reside in or to be displaced into these neighbourhoods, they are disproportionately exposed to environmental risk factors.

Moreover, gentrification enables and legitimises the exclusion of marginalised communities in multiple ways: 1) it devalues existing places and their residents in favour of regeneration, 2) it displaces longtime residents from regenerated neighbourhoods because of increasing property values, and/or 3) it alienates longtime residents as neighbourhood aesthetics, amenities and services change and become unaffordable and/or irrelevant.

As gentrification contributes to low-income households’ experiences of precarity and severs community ties and place attachments, it generates significant costs to personal and community health and wellbeing as well as social cohesion. The recommendations articulated in this brief emphasise the importance of transformative policy solutions that actively counter gentrification.
These include:
• Equitable investment in urban infrastructure
• Prioritising affordable housing
• Ensuring accessible transportation
• Empowering local communities
• Implementing a Te Tiriti o Waitangi approach to policy development

year: 2025