title: Pacific climate reflected in Waipuna Cave drip water hydrochemistry

authors: Nava-Fernandez, Cinthya

abstract: Cave microclimate and geochemical monitoring is vitally important for correct interpretations of proxy time series from speleothems with regard to past climatic and environmental dynamics. We present results of a comprehensive cave-monitoring programme in Waipuna Cave in the North Island of New Zealand, a region that is strongly influenced by the Southern Westerlies and the El Niño–Southern Oscillation (ENSO). This study aims to characterise the response of the Waipuna Cave hydrological system to atmospheric circulation dynamics in the southwestern Pacific region in order to assure the quality of ongoing palaeo-environmental reconstructions from this cave. Drip water from 10 drip sites was collected at roughly monthly intervals for a period of ca. 3 years for isotopic (δ18O, δD, d-excess parameter, δ17O, and 17Oexcess) and elemental (Mg∕Ca and Sr∕Ca) analysis. The monitoring included spot measurements of drip rates and cave air CO2 concentration. Cave air temperature and drip rates were also continuously recorded by automatic loggers. These datasets were compared to surface air temperature, rainfall, and potential evaporation from nearby meteorological stations to test the degree of signal transfer and expression of surface environmental conditions in Waipuna Cave hydrochemistry. Based on the drip response dynamics to rainfall and other characteristics, we identified three types of discharge associated with hydrological routing in Waipuna Cave: (i) type 1 – diffuse flow, (ii) type 2 – fracture flow, and (iii) type 3 – combined flow. Drip water isotopes do not reflect seasonal variability but show higher values during severe drought. Drip water δ18O values are characterised by small variability and reflect the mean isotopic signature of precipitation, testifying to rapid and thorough homogenisation in the epikarst. Mg∕Ca and Sr∕Ca ratios in drip waters are predominantly controlled by prior calcite precipitation (PCP). Prior calcite precipitation is strongest during austral summer (December–February), reflecting drier conditions and a lack of effective infiltration, and is weakest during the wet austral winter (July–September). The Sr∕Ca ratio is particularly sensitive to ENSO conditions due to the interplay of congruent or incongruent host rock dissolution, which manifests itself in lower Sr∕Ca in above-average warmer and wetter (La Niña-like) conditions. Our microclimatic observations at Waipuna Cave provide a valuable baseline for the rigorous interpretation of speleothem proxy records aiming at reconstructing the past expression of Pacific climate modes.

text: Pacific climate reflected in Waipuna Cave drip water hydrochemistry Cave microclimate and geochemical monitoring is vitally important for correct interpretations of proxy time series from speleothems with regard to past climatic and environmental dynamics. We present results of a comprehensive cave-monitoring programme in Waipuna Cave in the North Island of New Zealand, a region that is strongly influenced by the Southern Westerlies and the El Niño–Southern Oscillation (ENSO). This study aims to characterise the response of the Waipuna Cave hydrological system to atmospheric circulation dynamics in the southwestern Pacific region in order to assure the quality of ongoing palaeo-environmental reconstructions from this cave. Drip water from 10 drip sites was collected at roughly monthly intervals for a period of ca. 3 years for isotopic (δ18O, δD, d-excess parameter, δ17O, and 17Oexcess) and elemental (Mg∕Ca and Sr∕Ca) analysis. The monitoring included spot measurements of drip rates and cave air CO2 concentration. Cave air temperature and drip rates were also continuously recorded by automatic loggers. These datasets were compared to surface air temperature, rainfall, and potential evaporation from nearby meteorological stations to test the degree of signal transfer and expression of surface environmental conditions in Waipuna Cave hydrochemistry. Based on the drip response dynamics to rainfall and other characteristics, we identified three types of discharge associated with hydrological routing in Waipuna Cave: (i) type 1 – diffuse flow, (ii) type 2 – fracture flow, and (iii) type 3 – combined flow. Drip water isotopes do not reflect seasonal variability but show higher values during severe drought. Drip water δ18O values are characterised by small variability and reflect the mean isotopic signature of precipitation, testifying to rapid and thorough homogenisation in the epikarst. Mg∕Ca and Sr∕Ca ratios in drip waters are predominantly controlled by prior calcite precipitation (PCP). Prior calcite precipitation is strongest during austral summer (December–February), reflecting drier conditions and a lack of effective infiltration, and is weakest during the wet austral winter (July–September). The Sr∕Ca ratio is particularly sensitive to ENSO conditions due to the interplay of congruent or incongruent host rock dissolution, which manifests itself in lower Sr∕Ca in above-average warmer and wetter (La Niña-like) conditions. Our microclimatic observations at Waipuna Cave provide a valuable baseline for the rigorous interpretation of speleothem proxy records aiming at reconstructing the past expression of Pacific climate modes.

year: 2020

title: PolyLM: Learning about polysemy through language modeling

authors: Ansell, Alan

abstract: To avoid the “meaning conflation deficiency” of word embeddings, a number of models have aimed to embed individual word senses. These methods at one time performed well on tasks such as word sense induction (WSI), but they have since been overtaken by task-specific techniques which exploit contextualized embeddings. However, sense embeddings and contextualization need not be mutually exclusive. We introduce PolyLM, a method which formulates the task of learning sense embeddings as a language modeling problem, allowing contextualization techniques to be applied. PolyLM is based on two underlying assumptions about word senses: firstly, that the probability of a word occurring in a given context is equal to the sum of the probabilities of its individual senses occurring; and secondly, that for a given occurrence of a word, one of its senses tends to be much more plausible in the context than the others. We evaluate PolyLM on WSI, showing that it performs considerably better than previous sense embedding techniques, and matches the current state-of-the-art specialized WSI method despite having six times fewer parameters. Code and pre-trained models are available at https://github.com/AlanAnsell/PolyLM.

text: PolyLM: Learning about polysemy through language modeling To avoid the “meaning conflation deficiency” of word embeddings, a number of models have aimed to embed individual word senses. These methods at one time performed well on tasks such as word sense induction (WSI), but they have since been overtaken by task-specific techniques which exploit contextualized embeddings. However, sense embeddings and contextualization need not be mutually exclusive. We introduce PolyLM, a method which formulates the task of learning sense embeddings as a language modeling problem, allowing contextualization techniques to be applied. PolyLM is based on two underlying assumptions about word senses: firstly, that the probability of a word occurring in a given context is equal to the sum of the probabilities of its individual senses occurring; and secondly, that for a given occurrence of a word, one of its senses tends to be much more plausible in the context than the others. We evaluate PolyLM on WSI, showing that it performs considerably better than previous sense embedding techniques, and matches the current state-of-the-art specialized WSI method despite having six times fewer parameters. Code and pre-trained models are available at https://github.com/AlanAnsell/PolyLM.

year: 2021

title: He tangi mai i te puehu: He whakatewhatewha i te mahi whakamāori me te reo ā-tuhi a ngā tūpuna

authors: Apiata, Hāwea

subjects: Māori spirituality

abstract: Kei te pūtahi o tēnei tuhinga whakapae ko te whakatewhatewha i te whakapapa o te whakaaro Māori (Māori intellectual history) mā ēnei pātai e rua: He aha ā te Māori i tuhituhi ai i te tōmuatanga o te rautau rua tekau? Ā, he pēhea tāna wetewete i ngā huatau whakawairua nō waho i te ao Māori? 

Ina koa, ko tā te tuhinga whakapae nei he whakaaranga, he whakaatu hoki i ētahi huarahi e toru hei rangahau i ngā whakapapa o te whakaaro taketake: ko te ketuketu rua mahara (archival research); ko te tātari ariā (conceptual analysis); me te reo e whakamahia ana kia wetewete i te kaupapa. Mā te mahi ketuketu rua mahara e āhei ai ki te wānanga i ngā whakaputanga a Wiremu Takana, he kaituhi, he kaiwhakamāori nō Ngāti Kahungunu. Ka whakaputaina tāna tuhinga tuatahi i te tau 1915. Ā, e rua anō i whakaputaina e ia i te tau whai muri mai i 1916. Ko ēnei tuhinga āna e whakatewhatewha ana i te whakamāoritanga o te rongopai me te āheinga o ngā pūrākau Māori kia whakamārama i ngā whakaakoranga Moromona. Kāore anō kia āta tātaritia, kia āta rangahaua āna pukapuka e tētahi atu o mua. Ko te huarahi rangahau tuarua ko te tātari i te whakamāoritanga o ētahi ariā whakawairua e kitea ana i roto i ngā karaipiture o te Hāhi o Ihu Karaiti o te Hunga Tapu o ngā Rā o Muri nei. E toru ngā ariā kua tīpakongia hei tirotiro, arā, ko heaven, hell me baptism. Ā, hei whakawhānui atu i te titiro ki tēnei kaupapa, ka huritaongia ngā hua o te tuhinga reo Māori, arā, ka matapakina ngā take kia tuhituhi i te mahi rangahau i roto i te reo Māori.

I te mutunga iho, mā te āta wānanga i ngā whakaputanga reo Māori a te Hāhi o Ihu Karaiti (LDS) e whakawhānuitia ai tō tātou māramatanga ki te hītori o te mahi whakaputa pukapuka i roto i te Hāhi, te mahi punenga a te Māori, te whakareretanga o ngā tuhituhinga reo Māori, me te hītori o te Hāhi o Ihu Karaiti i Aotearoa nei.

text: He tangi mai i te puehu: He whakatewhatewha i te mahi whakamāori me te reo ā-tuhi a ngā tūpuna Kei te pūtahi o tēnei tuhinga whakapae ko te whakatewhatewha i te whakapapa o te whakaaro Māori (Māori intellectual history) mā ēnei pātai e rua: He aha ā te Māori i tuhituhi ai i te tōmuatanga o te rautau rua tekau? Ā, he pēhea tāna wetewete i ngā huatau whakawairua nō waho i te ao Māori? 

Ina koa, ko tā te tuhinga whakapae nei he whakaaranga, he whakaatu hoki i ētahi huarahi e toru hei rangahau i ngā whakapapa o te whakaaro taketake: ko te ketuketu rua mahara (archival research); ko te tātari ariā (conceptual analysis); me te reo e whakamahia ana kia wetewete i te kaupapa. Mā te mahi ketuketu rua mahara e āhei ai ki te wānanga i ngā whakaputanga a Wiremu Takana, he kaituhi, he kaiwhakamāori nō Ngāti Kahungunu. Ka whakaputaina tāna tuhinga tuatahi i te tau 1915. Ā, e rua anō i whakaputaina e ia i te tau whai muri mai i 1916. Ko ēnei tuhinga āna e whakatewhatewha ana i te whakamāoritanga o te rongopai me te āheinga o ngā pūrākau Māori kia whakamārama i ngā whakaakoranga Moromona. Kāore anō kia āta tātaritia, kia āta rangahaua āna pukapuka e tētahi atu o mua. Ko te huarahi rangahau tuarua ko te tātari i te whakamāoritanga o ētahi ariā whakawairua e kitea ana i roto i ngā karaipiture o te Hāhi o Ihu Karaiti o te Hunga Tapu o ngā Rā o Muri nei. E toru ngā ariā kua tīpakongia hei tirotiro, arā, ko heaven, hell me baptism. Ā, hei whakawhānui atu i te titiro ki tēnei kaupapa, ka huritaongia ngā hua o te tuhinga reo Māori, arā, ka matapakina ngā take kia tuhituhi i te mahi rangahau i roto i te reo Māori.

I te mutunga iho, mā te āta wānanga i ngā whakaputanga reo Māori a te Hāhi o Ihu Karaiti (LDS) e whakawhānuitia ai tō tātou māramatanga ki te hītori o te mahi whakaputa pukapuka i roto i te Hāhi, te mahi punenga a te Māori, te whakareretanga o ngā tuhituhinga reo Māori, me te hītori o te Hāhi o Ihu Karaiti i Aotearoa nei.

year: 2021