title: Oxytocin and Vasopressin Neuronal Activity In Response to Novel Versus Familiar Object Exposure In Mice

authors: Gerring, Crystal

subjects: oxytocin

abstract: Oxytocin (OT) and vasopressin (AVP), peptides synthesised in the hypothalamic supraoptic and paraventricular nuclei, are released during the introduction to a familiar or novel stimulus in low-stress social and environmental scenarios. Importantly, it is unknown whether the activity of neurons synthesising OT and AVP differs when animals are exposed to novel versus familiar objects.  Therefore, mice were subjected to a short-term presence of a novel or familiar, small and distinctively shaped plastic object in a pre-exposed arena.  Immunohistochemical analysis following exposure to a novel versus familiar object showed significantly greater activation of OT and AVP neurons in the paraventricular nucleus of the hypothalamus when exposed to a familiar stimulus versus a novel stimulus. Furthermore, immunohistochemical analysis showed an increasing, but not significant, trend in the number of active OT and AVP neurons in the supraoptic nucleus in response to a novel stimulus versus a familiar stimulus.  Mice who received intraperitoneal injections of OT receptor antagonist L-368,899 prior to being exposed to a familiar versus a novel object showed a significant increase in the amount of time spent with a familiar object and a decrease of time spent with a novel object.  We conclude that introduction to novelty results in a decrease in OT neuronal activity as well as changes in AVP neuronal activity in the paraventricular nucleus of the hypothalamus.

text: Oxytocin and Vasopressin Neuronal Activity In Response to Novel Versus Familiar Object Exposure In Mice Oxytocin (OT) and vasopressin (AVP), peptides synthesised in the hypothalamic supraoptic and paraventricular nuclei, are released during the introduction to a familiar or novel stimulus in low-stress social and environmental scenarios. Importantly, it is unknown whether the activity of neurons synthesising OT and AVP differs when animals are exposed to novel versus familiar objects.  Therefore, mice were subjected to a short-term presence of a novel or familiar, small and distinctively shaped plastic object in a pre-exposed arena.  Immunohistochemical analysis following exposure to a novel versus familiar object showed significantly greater activation of OT and AVP neurons in the paraventricular nucleus of the hypothalamus when exposed to a familiar stimulus versus a novel stimulus. Furthermore, immunohistochemical analysis showed an increasing, but not significant, trend in the number of active OT and AVP neurons in the supraoptic nucleus in response to a novel stimulus versus a familiar stimulus.  Mice who received intraperitoneal injections of OT receptor antagonist L-368,899 prior to being exposed to a familiar versus a novel object showed a significant increase in the amount of time spent with a familiar object and a decrease of time spent with a novel object.  We conclude that introduction to novelty results in a decrease in OT neuronal activity as well as changes in AVP neuronal activity in the paraventricular nucleus of the hypothalamus.

year: 2016

title: An Adaptive Model-based Mutation Operator for the Wind Farm Layout Optimisation Problem

authors: Mayo, Michael

subjects: Machine learning

abstract: A novel mutation operator for the wind farm layout optimisation problem is proposed and tested. When a wind farm layout is simulated, statistics such as an individual turbine’s wake free ratio can be computed. These statistics are in addition to the global measure being optimised, for example the overall cost of energy extraction of the farm. We present algorithms that first of all build a predictive model of the wake free ratio across an entire wind farm. This model is then used inside a mutation operator to perturb turbines towards positions of high predicted wake free ratio. We evaluate our approach by comparing a 1+1 Evolutionary Strategy using this new mutation operator vs. the same algorithm with a more standard random mutation operator, and show that our new operator leads to the discovery of wind farm layouts having a statistically significantly lower cost of energy extraction.

text: An Adaptive Model-based Mutation Operator for the Wind Farm Layout Optimisation Problem A novel mutation operator for the wind farm layout optimisation problem is proposed and tested. When a wind farm layout is simulated, statistics such as an individual turbine’s wake free ratio can be computed. These statistics are in addition to the global measure being optimised, for example the overall cost of energy extraction of the farm. We present algorithms that first of all build a predictive model of the wake free ratio across an entire wind farm. This model is then used inside a mutation operator to perturb turbines towards positions of high predicted wake free ratio. We evaluate our approach by comparing a 1+1 Evolutionary Strategy using this new mutation operator vs. the same algorithm with a more standard random mutation operator, and show that our new operator leads to the discovery of wind farm layouts having a statistically significantly lower cost of energy extraction.

year: 2015

title: Radiocarbon dates on desiccated moa (Dinornithiformes) flesh from Inland Otago, New Zealand

authors: Anderson, Atholl

subjects: New Zealand

abstract: Remains of soft tissues from extinct moa (Dinornithiformes), mainly desiccated sinew, muscle, skin, and feathers have been recovered rather seldom but their distribution is distinctive. Of 22 records of such finds accumulated between 1864 and 1987, 15 came from inland Otago (Anderson 1989: 67–68, Table 5.2), west of Dunedin in the southern South Island. Most were found in the late nineteenth century (13 records) in rockshelters, clefts or alluvial sediments and were regarded at the time as evidence of the survival of moa up to about AD 1800 (Hutton and Coughtrey 1874a). Improbable as this latter point is, it has not been tested by radiocarbon dating until now. Our particular impetus to do so, however, arises in another way. It is from research, again largely within inland Otago, on Maori artefacts which have also been made from various other kinds of soft tissues (flax, grasses, dog skin, bird skin, feathers etc.). A series of accelerator mass spectrometry (AMS) radiocarbon dates on these (Anderson et al., n.d.) shows that they are exclusively late, post-AD 1650, which begs the question of why the age range does not extend across the full prehistoric period, beginning about AD 1300.

text: Radiocarbon dates on desiccated moa (Dinornithiformes) flesh from Inland Otago, New Zealand Remains of soft tissues from extinct moa (Dinornithiformes), mainly desiccated sinew, muscle, skin, and feathers have been recovered rather seldom but their distribution is distinctive. Of 22 records of such finds accumulated between 1864 and 1987, 15 came from inland Otago (Anderson 1989: 67–68, Table 5.2), west of Dunedin in the southern South Island. Most were found in the late nineteenth century (13 records) in rockshelters, clefts or alluvial sediments and were regarded at the time as evidence of the survival of moa up to about AD 1800 (Hutton and Coughtrey 1874a). Improbable as this latter point is, it has not been tested by radiocarbon dating until now. Our particular impetus to do so, however, arises in another way. It is from research, again largely within inland Otago, on Maori artefacts which have also been made from various other kinds of soft tissues (flax, grasses, dog skin, bird skin, feathers etc.). A series of accelerator mass spectrometry (AMS) radiocarbon dates on these (Anderson et al., n.d.) shows that they are exclusively late, post-AD 1650, which begs the question of why the age range does not extend across the full prehistoric period, beginning about AD 1300.

year: 2010