title: An examination of the effect of messages on cooperation under double-blind and single-blind payoff procedures

authors: Deck, Cary

subjects: Anonymity

abstract: Previous research has suggested that communication and especially promises increase cooperation in laboratory experiments. This has been taken as evidence for internal motivations such as guilt aversion or preference for promise keeping. The goal of this paper was to examine messages under a double-blind payoff procedure to test the alternative explanation that promise keeping is due to external influence and reputational concerns. Employing a 2×2 design, we find no evidence that communication increases the overall level of cooperation in our experiments with double-blind payoff procedures. However, we also find no evidence that communication impacts cooperation in our experiments with single-blind payoff procedures. Further, the payoff procedure does not appear to impact aggregate cooperation.

text: An examination of the effect of messages on cooperation under double-blind and single-blind payoff procedures Previous research has suggested that communication and especially promises increase cooperation in laboratory experiments. This has been taken as evidence for internal motivations such as guilt aversion or preference for promise keeping. The goal of this paper was to examine messages under a double-blind payoff procedure to test the alternative explanation that promise keeping is due to external influence and reputational concerns. Employing a 2×2 design, we find no evidence that communication increases the overall level of cooperation in our experiments with double-blind payoff procedures. However, we also find no evidence that communication impacts cooperation in our experiments with single-blind payoff procedures. Further, the payoff procedure does not appear to impact aggregate cooperation.

year: 2013

title: Taumafaina o le ‘ava Samoa, a’afiaga o le mafaufau, ma le ave taavale (Traditional kava-drinking, cognition and driver fitness [Samoan])

authors: Aporosa, S. 'Apo'

abstract: ‘Ava, po'o se 'La’au mai le Atua o le Lagi', ua fa’aigoaina ai e nisi. Ua fa’atupulaia lona ola lauusiusi i so’o se vaega o le Pasefika (Moananuiakea). Ua fa’aaogaina foi mo vaila’au ma togafitiga fa’afoma’i fa’ale-aganu’u, ma o ona a'a foi ua fa’aaoga e tu'itu'i fa’amalu, ona palu fa’atasi lea i se suavai ma tatau fa’amama, ona inu lea e malolo i ai pe fa’amalolo ai foi le tino. O le ava e maoa'e tele lona taua ma lona fa’aaogaina i le aganu’u, ae talu ai ona ua inuina e tagata se suavai ava tele mo se taimi umi foi, ua fa’aleoina ai ni lagona popole ma atugaluga o le toatele ona o ni a'afiaga e ono alia'e ma tutupu mai ai, e a'afia ai le saogalemu o le aveina o se ta’avale. O le ali’i su'es'ue mai le Iunivesite o Waikato i Niu Sila o Dr Apo Aporosa, ua ia su'esu'eina ni a'afiaga po'o ni fa’afitauli e ono alia'e mai, pe afai o le a e aveina se ta’avale ae sa e taumafa/inu ava. E aofia ai aafiaga i le mafaufau lelei ma le ave taavale saogalemū. O lo’o su'esu'eina e le ali’i su'esu'e ia Dr Apo Aporosa ni a'afiaga ma se malamalama’aga fa'ale-mafaufau, po'o ni fa’alavelave e ono tutupu foi, pe afai e te aveina se ta’avale, ae sa e taumafa pe inuina foi se ava. 

(Kava, or ‘the plant of the gods’, grows widely across tropical Moananuiākea (the Pacific). Used in traditional medicine, its roots are also pounded and strained through water to make a drink with relaxant effects. Kava has deep cultural significance, but because it is drunk in large quantities over several hours, concerns have been raised about its effects on driver safety. Dr ‘Apo’ Aporosa, a Research Fellow at the University of Waikato in New Zealand, has studied the impact of traditional kava use on cognition and its implications for driver fitness. The findings of that research are presented here in the Samoan language.)

text: Taumafaina o le ‘ava Samoa, a’afiaga o le mafaufau, ma le ave taavale (Traditional kava-drinking, cognition and driver fitness [Samoan]) ‘Ava, po'o se 'La’au mai le Atua o le Lagi', ua fa’aigoaina ai e nisi. Ua fa’atupulaia lona ola lauusiusi i so’o se vaega o le Pasefika (Moananuiakea). Ua fa’aaogaina foi mo vaila’au ma togafitiga fa’afoma’i fa’ale-aganu’u, ma o ona a'a foi ua fa’aaoga e tu'itu'i fa’amalu, ona palu fa’atasi lea i se suavai ma tatau fa’amama, ona inu lea e malolo i ai pe fa’amalolo ai foi le tino. O le ava e maoa'e tele lona taua ma lona fa’aaogaina i le aganu’u, ae talu ai ona ua inuina e tagata se suavai ava tele mo se taimi umi foi, ua fa’aleoina ai ni lagona popole ma atugaluga o le toatele ona o ni a'afiaga e ono alia'e ma tutupu mai ai, e a'afia ai le saogalemu o le aveina o se ta’avale. O le ali’i su'es'ue mai le Iunivesite o Waikato i Niu Sila o Dr Apo Aporosa, ua ia su'esu'eina ni a'afiaga po'o ni fa’afitauli e ono alia'e mai, pe afai o le a e aveina se ta’avale ae sa e taumafa/inu ava. E aofia ai aafiaga i le mafaufau lelei ma le ave taavale saogalemū. O lo’o su'esu'eina e le ali’i su'esu'e ia Dr Apo Aporosa ni a'afiaga ma se malamalama’aga fa'ale-mafaufau, po'o ni fa’alavelave e ono tutupu foi, pe afai e te aveina se ta’avale, ae sa e taumafa pe inuina foi se ava. 

(Kava, or ‘the plant of the gods’, grows widely across tropical Moananuiākea (the Pacific). Used in traditional medicine, its roots are also pounded and strained through water to make a drink with relaxant effects. Kava has deep cultural significance, but because it is drunk in large quantities over several hours, concerns have been raised about its effects on driver safety. Dr ‘Apo’ Aporosa, a Research Fellow at the University of Waikato in New Zealand, has studied the impact of traditional kava use on cognition and its implications for driver fitness. The findings of that research are presented here in the Samoan language.)

year: 2023

title: A core phyllosphere microbiome exists across distant populations of a tree species indigenous to New Zealand

authors: Noble, Anya S.

subjects: Science & Technology

abstract: The phyllosphere microbiome is increasingly recognised as an influential component of plant physiology, yet it remains unclear whether stable host-microbe associations generally exist in the phyllosphere. Leptospermum scoparium (mānuka) is a tea tree indigenous to New Zealand, and honey derived from mānuka is widely known to possess unique antimicrobial properties. However, the host physiological traits associated with these antimicrobial properties vary widely, and the specific cause of such variation has eluded scientists despite decades of research. Notably, the mānuka phyllosphere microbiome remains uncharacterised, and its potential role in mediating host physiology has not been considered. Working within the prevailing core microbiome conceptual framework, we hypothesise that the phyllosphere microbiome of mānuka exhibits specific host association patterns congruent with those of a microbial community under host selective pressure (null hypothesis: the mānuka phyllosphere microbiome is recruited stochastically from the surrounding environment). To examine our hypothesis, we characterised the phyllosphere and associated soil microbiomes of five distinct and geographically distant mānuka populations across the North Island of New Zealand. We identified a habitat-specific and relatively abundant core microbiome in the mānuka phyllosphere, which was persistent across all samples. In contrast, non-core phyllosphere microorganisms exhibited significant variation across individual host trees and populations that was strongly driven by environmental and spatial factors. Our results demonstrate the existence of a dominant and ubiquitous core microbiome in the phyllosphere of mānuka, supporting our hypothesis that phyllosphere microorganisms of mānuka exhibit specific host association and potentially mediate physiological traits of this nationally and culturally treasured indigenous plant. In addition, our results illustrate biogeographical patterns in mānuka phyllosphere microbiomes and offer insight into factors contributing to phyllosphere microbiome assembly.

text: A core phyllosphere microbiome exists across distant populations of a tree species indigenous to New Zealand The phyllosphere microbiome is increasingly recognised as an influential component of plant physiology, yet it remains unclear whether stable host-microbe associations generally exist in the phyllosphere. Leptospermum scoparium (mānuka) is a tea tree indigenous to New Zealand, and honey derived from mānuka is widely known to possess unique antimicrobial properties. However, the host physiological traits associated with these antimicrobial properties vary widely, and the specific cause of such variation has eluded scientists despite decades of research. Notably, the mānuka phyllosphere microbiome remains uncharacterised, and its potential role in mediating host physiology has not been considered. Working within the prevailing core microbiome conceptual framework, we hypothesise that the phyllosphere microbiome of mānuka exhibits specific host association patterns congruent with those of a microbial community under host selective pressure (null hypothesis: the mānuka phyllosphere microbiome is recruited stochastically from the surrounding environment). To examine our hypothesis, we characterised the phyllosphere and associated soil microbiomes of five distinct and geographically distant mānuka populations across the North Island of New Zealand. We identified a habitat-specific and relatively abundant core microbiome in the mānuka phyllosphere, which was persistent across all samples. In contrast, non-core phyllosphere microorganisms exhibited significant variation across individual host trees and populations that was strongly driven by environmental and spatial factors. Our results demonstrate the existence of a dominant and ubiquitous core microbiome in the phyllosphere of mānuka, supporting our hypothesis that phyllosphere microorganisms of mānuka exhibit specific host association and potentially mediate physiological traits of this nationally and culturally treasured indigenous plant. In addition, our results illustrate biogeographical patterns in mānuka phyllosphere microbiomes and offer insight into factors contributing to phyllosphere microbiome assembly.

year: 2020