Variabilidade dos róticos produzidos por falantes de Rebouças e Irati (PR) : uma análise acústica

Orientadora: Prof.ª Dra. Adelaide H. P. SilvaDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Humanas, Programa de Pós-Graduação em Letras. Defesa : Curitiba, 28/03/2019Inclui referências: p. 122-126Área de concentração: Estudos LinguísticosResumo: Este trabalho faz, por meio da análise acústica, um estudo do rótico em início de palavra produzido por falantes de Rebouças e Irati (PR) que ainda têm a vibrante alveolar presente na fala. O estudo parte de dois objetivos principais: o primeiro, de ordem linguística, verifica a produção dos róticos em início de palavra em contexto precedente às vogais [i] e [a]. A proposta parte das premissas do DAC (Degree of Articulatory Constraint) model (RECASENS; PALLARÈS; FONTDEVILA, 1997), um modelo de análise fonética que prevê que a coarticulação entre os segmentos está relacionada com os diferentes níveis de constrição articulatória. A hipótese elaborada para a pesquisa é uma maior influência coarticulatória da vogal [i] sobre a produção da vibrante, fato que tende a desfavorecer a ocorrência de vibrantes nesse contexto vocálico e resultar em variantes espirantizadas (sobreposição de ruído fricativo), visto que há um antagonismo nos movimentos articulatórios para a produção da vibrante e da vogal [i]. O segundo objetivo, de ordem metodológica, contrasta a coleta de dados em dois diferentes métodos, frase-veículo e narrativa curta, e traz como hipótese que o maior concatenamento de elementos textuais, durante a leitura da narrativa, tende a favorecer a hipoarticulação e, como resultado, uma maior espirantização de vibrantes. Destaca-se que a vibrante é descrita na literatura da área como um som bastante exigente em termos articulatórios, desse modo, situações de produção que desfavoreçam seus requisitos podem implicar numa maior variabilidade. Assim, foi rodado um experimento fonético-acústico com nove participantes naturais dos referidos municípios, seis homens e três mulheres. Para análise dos dados, são utilizados os parâmetros acústicos de duração dos períodos de fechamento e abertura oral dos róticos vibrantes e as medidas de frequência dos dois primeiros formantes (F1, F2) dos róticos vibrantes. Os resultados gerais mostram que há gradiência na produção do rótico em posição inicial de palavra e confirmam as hipóteses levantadas: houve uma maior incidência de vibrantes espirantizadas em contexto de vogal [i], e estas se intensificaram nos dois contextos vocálicos durante a coleta por narrativa-curta. Palavras-chave: Análise acústica, vibrante alveolar, espirantização, fraseveículo, narrativa-curta.Abstract: This work performs, through acoustic analysis, a study of the rhotic sound produced by speakers of Rebouças and Irati (PR) who still have the alveolar trill present during speech. The study is based on two main objectives: the first one, of a linguistic nature, verifies the production of the rhotic at the beginning of the word in a context preceding the vowels [i] and [a].The proposal starts from the premises of the DAC (Degree of Articulatory Constraint), a phonetic analysis model that predicts that the coarticulation between the segments is related to the different levels of articulatory constriction. The hypothesis is that there is a greater coarticulatory influence of the vowel [i] on the production of the trill, which tends to disfavor the occurrence of trills in this vowel context and result in spirantized variants (overlapping of fricative noise), since there is an antagonism in the movements necessary for the production of the trill and the vowel [i]. The second objective, methodological, contrasts the data collection in two different methods, vehicle-phrase and short-narrative, and hypothesizes that the greater concatenation of textual elements during the reading of the narrative tends to favor hypoarticulation and, as a result, a greater spirantization of trills. It is worth noting that the trill is described in the literature of the field as a very demanding sound in terms of articulation and aerodynamics, thus, production situations that would disadvantage its production requirements, may imply greater variability. Thus, a phonetic-acoustic experiment was performed with nine natural participants from the mentioned municipalities, six men and three women. To analyze the date, it is utilized the acoustic parameters of the closing periods and oral opening of the trill rhotic and the frequency measurements of the first two formants (F1, F2) of the trill rhotic. The general results show a great deal of gradation in the production of the rhotic in the initial position of the word and confirm the hypotheses raised: there was a higher incidence of spiritanized trills in the context of the vowel [i], and these intensified in the two vowel contexts during the collection by short-narrative. Key words: Acoustic analysis, alveolar trill, spirantization, vehicle-phrase, shortnarrative

A strong CO<sub>2</sub> sink enhanced by eutrophication in a tropical coastal embayment (Guanabara Bay, Rio de Janeiro, Brazil)

In contrast to its small surface area, the coastal zone plays a disproportionate role in the global carbon cycle. Carbon production, transformation, emission and burial rates at the land–ocean interface are significant at the global scale but still poorly known, especially in tropical regions. Surface water pCO2 and ancillary parameters were monitored during nine field campaigns between April 2013 and April 2014 in Guanabara Bay, a tropical eutrophic to hypertrophic semi-enclosed estuarine embayment surrounded by the city of Rio de Janeiro, southeast Brazil. Water pCO2 varied between 22 and 3715 ppmv in the bay, showing spatial, diurnal and seasonal trends that mirrored those of dissolved oxygen (DO) and chlorophyll a (Chl a). Marked pCO2 undersaturation was prevalent in the shallow, confined and thermally stratified waters of the upper bay, whereas pCO2 oversaturation was restricted to sites close to the small river mouths and small sewage channels, which covered only 10 % of the bay's area. Substantial daily variations in pCO2 (up to 395 ppmv between dawn and dusk) were also registered and could be integrated temporally and spatially for the establishment of net diurnal, seasonal and annual CO2 fluxes. In contrast to other estuaries worldwide, Guanabara Bay behaved as a net sink of atmospheric CO2, a property enhanced by the concomitant effects of strong radiation intensity, thermal stratification, and high availability of nutrients, which promotes phytoplankton development and net autotrophy. The calculated CO2 fluxes for Guanabara Bay ranged between −9.6 and −18.3 mol C m−2 yr−1, of the same order of magnitude as the organic carbon burial and organic carbon inputs from the watershed. The positive and high net community production (52.1 mol C m−2 yr−1) confirms the high carbon production in the bay. This autotrophic metabolism is apparently enhanced by eutrophication. Our results show that global CO2 budgetary assertions still lack information on tropical, marine-dominated estuarine systems, which are affected by thermal stratification and eutrophication and behave specifically with respect to atmospheric CO2

Aragonite saturation state in a continental shelf (Gulf of Cádiz, SW IberianPeninsula): Evidences of acidification in the coastal area

The spatiotemporal variability of aragonite saturation state (ΩAr) has been studied in the eastern shelf of the Gulf of Cádiz (GoC) (SW Iberian Peninsula). The study was carried out during the years 2014 and 2016 aboard twelve oceanographic cruises, along three or five transects, located between Cape Trafalgar and the Guadiana River. The GoC exhibited oversaturated of calcium carbonate with ΩAr mean values of 2.68 ± 0.30 in surface and 2.05 ± 0.15 in deep waters. pH, total alkalinity (TA), calcium concentration (Ca2+) and ΩAr showed a high variability within the surface mixed layer (SML, z 100 m), TA and Ca2+ concentration presented a conservative behaviour related to the distribution of the different water masses located in the GoC. The vertical variation of ΩAr also depends on the degree of mineralization of these water masses, obtaining the maximum values in the Subtropical North Atlantic Central Water (100–200 m), minimum values in the Subpolar North Atlantic Central Water (about 400 m), and intermediate values associated to the presence of the Mediterranean Water (>500 m). Results showed a significative acidification of the coastal areas, for those depths lower than 100 m from 2006 to 2016, with a mean decrease of pH and ΩAr of −0.0089 and −0.0552 yr−1, respectively. © 2021 The AuthorsThis work was funded by the Spanish CICYT (Spanish Program for Science and Technology) under the contract RTI2018-100865-B-C21 . Dolores Jiménez-López was financed by the University of Cádiz with a FPI fellowship (FPI-UCA) and Ana Sierra was financed by the Spanish Ministry of Education with a FPU fellowship (FPU2014-04048)

Do coastal wetlands drive or buffer coastal acidification?

peer reviewe

A global database of dissolved organic matter (DOM) concentration measurements in coastal waters (CoastDOM v1)

Measurements of dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP) con-centrations are used to characterize the dissolved organic matter (DOM) pool and are important components ofbiogeochemical cycling in the coastal ocean. Here, we present the first edition of a global database (CoastDOMv1; available at https://doi.org/10.1594/PANGAEA.964012, L\uf8nborg et al., 2023) compiling previously pub-lished and unpublished measurements of DOC, DON, and DOP in coastal waters. These data are complementedby hydrographic data such as temperature and salinity and, to the extent possible, other biogeochemical variables(e.g. chlorophyll a, inorganic nutrients) and the inorganic carbon system (e.g. dissolved inorganic carbon andtotal alkalinity). Overall, CoastDOM v1 includes observations of concentrations from all continents. However,most data were collected in the Northern Hemisphere, with a clear gap in DOM measurements from the SouthernHemisphere. The data included were collected from 1978 to 2022 and consist of 62 338 data points for DOC,20 356 for DON, and 13 533 for DOP. The number of measurements decreases progressively in the sequenceDOC > DON > DOP, reflecting both differences in the maturity of the analytical methods and the greater focuson carbon cycling by the aquatic science community. The global database shows that the average DOC concen-tration in coastal waters (average \ub1 standard deviation (SD): 182 \ub1 314 μmol C L−1; median: 103 μmol C L−1) is13-fold higher than the average coastal DON concentration (13.6 \ub1 30.4 μmol N L−1; median: 8.0 μmol N L−1),which is itself 39-fold higher than the average coastal DOP concentration (0.34 \ub1 1.11 μmol P L−1; median:0.18 μmol P L−1). This dataset will be useful for identifying global spatial and temporal patterns in DOM and willhelp facilitate the reuse of DOC, DON, and DOP data in studies aimed at better characterizing local biogeochem-ical processes; closing nutrient budgets; estimating carbon, nitrogen, and phosphorous pools; and establishing abaseline for modelling future changes in coastal waters

Ebullition was a major pathway of methane emissions from the aquaculture ponds in southeast China

Aquaculture ponds are hotspots of carbon cycling and important anthropogenic sources of the potent greenhouse gas methane (CH4). Despite the importance of CH4 ebullition in aquatic ecosystems, its magnitude and spatiotemporal variations in aquaculture ponds remain poorly understood. In this study, we determined the rates and spatiotemporal variations of ebullitive CH4 emissions from three mariculture ponds during the aquaculture period of two years at a subtropical estuary in southeast China. Our results showed that the mean ebullitive CH4 flux from the studied ponds was 14.9 mg CH4 m−2 h−1 during the aquaculture period and accounted for over 90% of the total CH4 emission, indicating the importance of ebullition as a major CH4 transport mechanism. Ebullitive CH4 emission demonstrated a clear seasonal pattern, with a peak value during the middle stage of aquaculture. Sediment temperature was found to be an important factor influencing the seasonal variations in CH4 ebullition. Ebullitive CH4 fluxes also exhibited considerable spatial variations within the ponds, with 49.7–71.8% of the whole pond CH4 ebullition being detected in the feeding zone where the large loading of sediment organic matter fueled CH4 production. Aquaculture ponds have much higher ebullitive CH4 effluxes than other aquatic ecosystems, which indicated the urgency to mitigate CH4 emission from aquaculture activities. Our findings highlighted that the importance of considering the large spatiotemporal variations in ebullitive CH4 flux in improving the accuracy of large-scale estimation of CH4 fluxes in aquatic ecosystems. Future studies should be conducted to characterize CH4 ebullitive fluxes over a greater number and diversity of aquaculture ponds and examine the mechanisms controlling CH4 ebullition in aquatic ecosystems

Spatial and seasonal variation of microphytoplankton community and the correlation with environmental parameters in a hypereutrophic tropical estuary - Maranhão - Brazil

O estuário do rio Bacanga apresenta um comportamento hidrodinâmico com fluxo de marés limitado por uma barragem. Ele é considerado como um ambiente hipereutrófico que recebe diariamente altas cargas de esgoto doméstico sem tratamento. Este trabalho teve como objetivo avaliar a variação espaço-sazonal da comunidade fitoplanctônica e suas relações com parâmetros ambientais. Amostragens bimestrais foram realizadas em seis pontos fixos entre 2012 e 2013, obtendo valores dos parâmetros físico-químicos e biológicos (clorofila a, composição e abundância do fitoplâncton) para realização das análises estatísticas. Os resultados indicam que a comunidade fitoplanctônica é representada por diatomáceas, sendo Skeletonema costatum a espécie dominante responsável por pulsos de florações em abril e junho de 2012. O predomínio dessa espécie está relacionado aos elevados teores de silicato, pH e turbidez da água. Outros eventos de florações como da Euglena gracilis e Chlamydomonas sp. foram registrados em fevereiro de 2013, quando os teores de fósforo total estiveram elevados e as taxas de oxigênio dissolvido foram superiores. Os dinoflagelados, cianobactérias e a diatomácea Thallassiosira sp. apresentaram ampla distribuição no período de estiagem e estão altamente correlacionados com a salinidade, transparência da água e nutrientes. Desta forma, a distribuição da comunidade fitoplanctônica é mais definida sazonalmente que espacialmenteThe Bacanga River Estuary has a hydrodynamic behavior and its tidal flow is limited by a dam. It is considered as a hypertrophic environment that receives daily high loads of domestic sewage without treatment. This study aimed to evaluate the spatial and temporal variation of phytoplankton community and its relationship with environmental parameters. Bi-monthly sampling campaigns were carried out at six fixed sites between 2012 and 2013. Physical-chemical and biological parameters were collected (chlorophyll a, phytoplankton composition and abundance) to perform the statistical correlations. The results indicate that phytoplankton community is mostly represented by diatoms, with Skeletonema costatum being the dominant species responsible for bloom in April and June of 2012. The dominance of this species is related to the high silicate concentrations, pH and turbidity. Other blooms events as well as the Euglena gracilis and Chlamydomonas sp. were recorded in February 2013, when the total phosphorus concentrations were high and the dissolved oxygen concentrations were higher. Dinoflagellates, cyanobacteria and diatom Thallassiosira sp. were widely distributed in the dry period and highly correlated with salinity, water transparency and nutrients. Hence, the distribution of phytoplankton community is more defined seasonally, rather than spatially