title: Possum Food Preferences under Progressive-Ratio and Concurrent-Schedules of Reinforcement

authors: Cronin, Ian Raymond

subjects: Preference

abstract: Three experiments compared various ways of examining food preferences in the common brushtail possum (Trischosurus vulpecula). The first experiment compared the preferences obtained between four foods using paired-stimulus (PS) and multiple-stimulus without-replacement (MSWO) assessments. The ranked orders identified by the two methods produced similar orders in individual possums, but were idiosyncratic across possums. Following this, Experiment 2 involved a progressive-ratio (PR) reinforcer assessment with all four foods used in the preference assessments of Experiment 1. For each possum, each of the four foods functioned as reinforcers when presented in a single-schedule arrangement, including those foods identified as less preferred. Experiment 3 used concurrent-schedules, with a PR schedule on one alternative and fixed-ratio (FR) on the other. It was found that higher break points and response rates, as well as flatter demand functions were found for the same food in both Experiment 2 and 3. It was also found that when the concurrent alternative was on an FR 50 schedule, the response rates, break points and Pmax values of the food on the PR schedule tended to be higher than when the concurrent alternative was on an FR 20 schedule. Overall, the PS and MSWO assessments were equally effective at identifying which foods would function as reinforcers during Experiment 2 and 3.

text: Possum Food Preferences under Progressive-Ratio and Concurrent-Schedules of Reinforcement Three experiments compared various ways of examining food preferences in the common brushtail possum (Trischosurus vulpecula). The first experiment compared the preferences obtained between four foods using paired-stimulus (PS) and multiple-stimulus without-replacement (MSWO) assessments. The ranked orders identified by the two methods produced similar orders in individual possums, but were idiosyncratic across possums. Following this, Experiment 2 involved a progressive-ratio (PR) reinforcer assessment with all four foods used in the preference assessments of Experiment 1. For each possum, each of the four foods functioned as reinforcers when presented in a single-schedule arrangement, including those foods identified as less preferred. Experiment 3 used concurrent-schedules, with a PR schedule on one alternative and fixed-ratio (FR) on the other. It was found that higher break points and response rates, as well as flatter demand functions were found for the same food in both Experiment 2 and 3. It was also found that when the concurrent alternative was on an FR 50 schedule, the response rates, break points and Pmax values of the food on the PR schedule tended to be higher than when the concurrent alternative was on an FR 20 schedule. Overall, the PS and MSWO assessments were equally effective at identifying which foods would function as reinforcers during Experiment 2 and 3.

year: 2012

title: High-level diversity of tailed phages, eukaryote-associated viruses, and virophage-like elements in the metaviromes of Antarctic soils

authors: Zablocki, Oliver

abstract: The metaviromes of two distinct Antarctic hyperarid desert soil communities have been characterized. Hypolithic communities, cyanobacterium-dominated assemblages situated on the ventral surfaces of quartz pebbles embedded in the desert pavement, showed higher virus diversity than surface soils, which correlated with previous bacterial community studies. Prokaryotic viruses (i.e., phages) represented the largest viral component (particularly Mycobacterium phages) in both habitats, with an identical hierarchical sequence abundance of families of tailed phages (Siphoviridae > Myoviridae > Podoviridae). No archaeal viruses were found. Unexpectedly, cyanophages were poorly represented in both metaviromes and were phylogenetically distant from currently characterized cyanophages. Putative phage genomes were assembled and showed a high level of unaffiliated genes, mostly from hypolithic viruses. Moreover, unusual gene arrangements in which eukaryotic and prokaryotic virus-derived genes were found within identical genome segments were observed. Phycodnaviridae and Mimiviridae viruses were the second-most-abundant taxa and more numerous within open soil. Novel virophage-like sequences (within the Sputnik clade) were identified. These findings highlight high-level virus diversity and novel species discovery potential within Antarctic hyperarid soils and may serve as a starting point for future studies targeting specific viral groups.

text: High-level diversity of tailed phages, eukaryote-associated viruses, and virophage-like elements in the metaviromes of Antarctic soils The metaviromes of two distinct Antarctic hyperarid desert soil communities have been characterized. Hypolithic communities, cyanobacterium-dominated assemblages situated on the ventral surfaces of quartz pebbles embedded in the desert pavement, showed higher virus diversity than surface soils, which correlated with previous bacterial community studies. Prokaryotic viruses (i.e., phages) represented the largest viral component (particularly Mycobacterium phages) in both habitats, with an identical hierarchical sequence abundance of families of tailed phages (Siphoviridae > Myoviridae > Podoviridae). No archaeal viruses were found. Unexpectedly, cyanophages were poorly represented in both metaviromes and were phylogenetically distant from currently characterized cyanophages. Putative phage genomes were assembled and showed a high level of unaffiliated genes, mostly from hypolithic viruses. Moreover, unusual gene arrangements in which eukaryotic and prokaryotic virus-derived genes were found within identical genome segments were observed. Phycodnaviridae and Mimiviridae viruses were the second-most-abundant taxa and more numerous within open soil. Novel virophage-like sequences (within the Sputnik clade) were identified. These findings highlight high-level virus diversity and novel species discovery potential within Antarctic hyperarid soils and may serve as a starting point for future studies targeting specific viral groups.

year: 2014-11-01

title: Te Kuranui

authors: Maxwell, Te Kahautu

abstract: Ko te tūāpapa o tēnei kōrero Te Kuranui he titiro ki te tūāpapa o Ōpōtiki Mai Tawhiti kapa haka. He aha te take i whakatūngia ai tēnei Kuranui e karangatia ana ko Ōpōtiki Mai Tawhiti? Hai tāhūhū mō tēnei tuhinga raurūtia tēnei kupu whakaari a Te Kōoti Arikirangi; “He Kura hoki ahau”, me tēnei wehenga o te mōteatea nāna; Te Pono ki runga rā, te ara mai o te tika. Tukua mai ki raro nā te maungarongo; te whana i tū ai nā te kotahitanga; te aroha i mau ai. Ana ko te Kupu Whakaari nei; He Kura hoki ahau he wewete i tēnei Kupu Whakaari kia kite i te hōhonu o te tikanga ōna hai whakatamārama i tō Te Kōoti wawata hai kura i tana iwi Ringatū me tā te kaituhi whakaraupapa i ēnei kura ki roto i te whakairotanga i te Kuranui nei.
Ka rua kua tātaritia tēnei wehenga o te mōteatea nei kia rima ōna wāhanga hai taki i tēnei tuhinga epā ana ki te Kuranui nei a Ōpōtiki Mai Tawhiti. Tuatahi Te Pono ki runga rā, ka titiro ki te kaituhi nei me tōna whakatipuranga i ōna kaumātua me ō rātou kuranga i a ia kia tohenihorau ki tōna ao Māori. He kuranga ēnei hai maungāngākau, maungāhinengaro ki te whakaturuki i te Kuranui a Ōpōtiki Mai Tawhiti. Te ara mai o te tika, ko te whakatūtanga o te kapa haka nei a Ōpōtiki Mai Tawhiti te Kuranui,arā te whakapaparanga mai i te kapa i tōna tīmatatanga ki te wā tonu nei. Tukua mai ki raro nā te maungarongo; ko te whakapono tēnei wāhanga, ko te ū o Ōpōtiki Mai Tawhiti ki tēnei kura a Te Kooti Arikirangi. Te whana i tū ai nā te kotahitanga;ko te titiro ki te pouārahi me te whakapau kaha ki te tuitui i ngā whakaaro o te katoa, ko te ranga i te iwi, ko te pupuri i te iwi, i te kapa haka ki tōna, rautaki, whāinga ko te whakakotahitanga i te iwi i raro i te kaupapa o Ōpōtiki Mai Tawhiti. Te aroha i mau ai, ko te aroha ki te iwi, ko te aroha ki te kaupapa, ko te whakaū, whakapūmau i te moemoeā kia whakahokia mai te toheariki ki te iwi kia tū toherauariki a Te Whakatōhea i raro i te korowai o Ōpōtiki Mai Tawhiti.

text: Te Kuranui Ko te tūāpapa o tēnei kōrero Te Kuranui he titiro ki te tūāpapa o Ōpōtiki Mai Tawhiti kapa haka. He aha te take i whakatūngia ai tēnei Kuranui e karangatia ana ko Ōpōtiki Mai Tawhiti? Hai tāhūhū mō tēnei tuhinga raurūtia tēnei kupu whakaari a Te Kōoti Arikirangi; “He Kura hoki ahau”, me tēnei wehenga o te mōteatea nāna; Te Pono ki runga rā, te ara mai o te tika. Tukua mai ki raro nā te maungarongo; te whana i tū ai nā te kotahitanga; te aroha i mau ai. Ana ko te Kupu Whakaari nei; He Kura hoki ahau he wewete i tēnei Kupu Whakaari kia kite i te hōhonu o te tikanga ōna hai whakatamārama i tō Te Kōoti wawata hai kura i tana iwi Ringatū me tā te kaituhi whakaraupapa i ēnei kura ki roto i te whakairotanga i te Kuranui nei.
Ka rua kua tātaritia tēnei wehenga o te mōteatea nei kia rima ōna wāhanga hai taki i tēnei tuhinga epā ana ki te Kuranui nei a Ōpōtiki Mai Tawhiti. Tuatahi Te Pono ki runga rā, ka titiro ki te kaituhi nei me tōna whakatipuranga i ōna kaumātua me ō rātou kuranga i a ia kia tohenihorau ki tōna ao Māori. He kuranga ēnei hai maungāngākau, maungāhinengaro ki te whakaturuki i te Kuranui a Ōpōtiki Mai Tawhiti. Te ara mai o te tika, ko te whakatūtanga o te kapa haka nei a Ōpōtiki Mai Tawhiti te Kuranui,arā te whakapaparanga mai i te kapa i tōna tīmatatanga ki te wā tonu nei. Tukua mai ki raro nā te maungarongo; ko te whakapono tēnei wāhanga, ko te ū o Ōpōtiki Mai Tawhiti ki tēnei kura a Te Kooti Arikirangi. Te whana i tū ai nā te kotahitanga;ko te titiro ki te pouārahi me te whakapau kaha ki te tuitui i ngā whakaaro o te katoa, ko te ranga i te iwi, ko te pupuri i te iwi, i te kapa haka ki tōna, rautaki, whāinga ko te whakakotahitanga i te iwi i raro i te kaupapa o Ōpōtiki Mai Tawhiti. Te aroha i mau ai, ko te aroha ki te iwi, ko te aroha ki te kaupapa, ko te whakaū, whakapūmau i te moemoeā kia whakahokia mai te toheariki ki te iwi kia tū toherauariki a Te Whakatōhea i raro i te korowai o Ōpōtiki Mai Tawhiti.

year: 2014-09-27