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1.
Digit Discov ; 2(5): 1233-1250, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-38013906

RESUMO

Large-language models (LLMs) such as GPT-4 caught the interest of many scientists. Recent studies suggested that these models could be useful in chemistry and materials science. To explore these possibilities, we organized a hackathon. This article chronicles the projects built as part of this hackathon. Participants employed LLMs for various applications, including predicting properties of molecules and materials, designing novel interfaces for tools, extracting knowledge from unstructured data, and developing new educational applications. The diverse topics and the fact that working prototypes could be generated in less than two days highlight that LLMs will profoundly impact the future of our fields. The rich collection of ideas and projects also indicates that the applications of LLMs are not limited to materials science and chemistry but offer potential benefits to a wide range of scientific disciplines.

2.
Data Brief ; 50: 109525, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37701711

RESUMO

This data article introduces a dataset comprising 1630 alkali-activated concrete (AAC) mixes, compiled from 106 literature sources. The dataset underwent extensive curation to address feature redundancy, transcription errors, and duplicate data, yielding refined data ready for further data-driven science in the field of AAC, where this effort constitutes a novelty. The carbon footprint associated with each material used in the AAC mixes, as well as the corresponding CO2 footprint of every mix, were approximated using two published articles. Serving as a foundation for future expansions and rigorous data applications, this dataset enables the characterization of AAC properties through machine learning algorithms or as a benchmark for performance comparison among different formulations. In summary, the dataset provides a resource for researchers focusing on AAC and related materials and offers insights into the environmental benefits of substituting traditional Portland concrete with AAC.

3.
Glob Chang Biol ; 29(15): 4234-4258, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37265254

RESUMO

Phytoplankton growth is controlled by multiple environmental drivers, which are all modified by climate change. While numerous experimental studies identify interactive effects between drivers, large-scale ocean biogeochemistry models mostly account for growth responses to each driver separately and leave the results of these experimental multiple-driver studies largely unused. Here, we amend phytoplankton growth functions in a biogeochemical model by dual-driver interactions (CO2 and temperature, CO2 and light), based on data of a published meta-analysis on multiple-driver laboratory experiments. The effect of this parametrization on phytoplankton biomass and community composition is tested using present-day and future high-emission (SSP5-8.5) climate forcing. While the projected decrease in future total global phytoplankton biomass in simulations with driver interactions is similar to that in control simulations without driver interactions (5%-6%), interactive driver effects are group-specific. Globally, diatom biomass decreases more with interactive effects compared with the control simulation (-8.1% with interactions vs. no change without interactions). Small-phytoplankton biomass, by contrast, decreases less with on-going climate change when the model accounts for driver interactions (-5.0% vs. -9.0%). The response of global coccolithophore biomass to future climate conditions is even reversed when interactions are considered (+33.2% instead of -10.8%). Regionally, the largest difference in the future phytoplankton community composition between the simulations with and without driver interactions is detected in the Southern Ocean, where diatom biomass decreases (-7.5%) instead of increases (+14.5%), raising the share of small phytoplankton and coccolithophores of total phytoplankton biomass. Hence, interactive effects impact the phytoplankton community structure and related biogeochemical fluxes in a future ocean. Our approach is a first step to integrate the mechanistic understanding of interacting driver effects on phytoplankton growth gained by numerous laboratory experiments into a global ocean biogeochemistry model, aiming toward more realistic future projections of phytoplankton biomass and community composition.


Assuntos
Diatomáceas , Fitoplâncton , Fitoplâncton/fisiologia , Mudança Climática , Dióxido de Carbono , Diatomáceas/fisiologia , Biomassa , Oceanos e Mares
4.
Sci Rep ; 10(1): 6144, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32273548

RESUMO

Primary production by phytoplankton represents a major pathway whereby atmospheric CO2 is sequestered in the ocean, but this requires iron, which is in scarce supply. As over 99% of iron is complexed to organic ligands, which increase iron solubility and microbial availability, understanding the processes governing ligand dynamics is of fundamental importance. Ligands within humic-like substances have long been considered important for iron complexation, but their role has never been explained in an oceanographically consistent manner. Here we show iron co-varying with electroactive humic substances at multiple open ocean sites, with the ratio of iron to humics increasing with depth. Our results agree with humic ligands composing a large fraction of the iron-binding ligand pool throughout the water column. We demonstrate how maximum dissolved iron concentrations could be limited by the concentration and binding capacity of humic ligands, and provide a summary of the key processes that could influence these parameters. If this relationship is globally representative, humics could impose a concentration threshold that buffers the deep ocean iron inventory. This study highlights the dearth of humic data, and the immediate need to measure electroactive humics, dissolved iron and iron-binding ligands simultaneously from surface to depth, across different ocean basins.

5.
J Speech Lang Hear Res ; 62(1): 177-189, 2019 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-30534994

RESUMO

Purpose For elderly listeners, it is more challenging to listen to 1 voice surrounded by other voices than for young listeners. This could be caused by a reduced ability to use acoustic cues-such as slight differences in onset time-for the segregation of concurrent speech signals. Here, we study whether the ability to benefit from onset asynchrony differs between young (18-33 years) and elderly (55-74 years) listeners. Method We investigated young (normal hearing, N = 20) and elderly (mildly hearing impaired, N = 26) listeners' ability to segregate 2 vowels with onset asynchronies ranging from 20 to 100 ms. Behavioral measures were complemented by a specific event-related brain potential component, the object-related negativity, indicating the perception of 2 distinct auditory objects. Results Elderly listeners' behavioral performance (identification accuracy of the 2 vowels) was considerably poorer than young listeners'. However, both age groups showed the same amount of improvement with increasing onset asynchrony. Object-related negativity amplitude also increased similarly in both age groups. Conclusion Both age groups benefit to a similar extent from onset asynchrony as a cue for concurrent speech segregation during active (behavioral measurement) and during passive (electroencephalographic measurement) listening.


Assuntos
Acústica da Fala , Percepção da Fala/fisiologia , Adulto , Fatores Etários , Idoso , Análise de Variância , Audiometria , Limiar Auditivo , Sinais (Psicologia) , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
Int J Audiol ; 57(sup3): S139-S145, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-27873543

RESUMO

OBJECTIVE: A generalised concept for hearing aid fitting and fine-tuning based on estimated individual traits is presented along first implementations in this report. DESIGN: To estimate the individual traits, a set of auditory model-based performance measures is used to generate promising candidates within the algorithm's parameter space for a subsequent subjective rating. For the subjective assessment, a fast and intuitive multi-stimulus test denoted as combined discrimination and classification (CoDiCl) is presented to capture user preferences for an optimised setting. STUDY SAMPLE: The estimation of individual traits is shown in an exemplary manner for a multidimensional coherence-based noise reduction algorithm. The dimensionality reduction was performed using differently weighted combinations of speech intelligibility index (SII) and perceived similarity measure (PSM). RESULTS: Nine reasonable alternative algorithm setting candidates were extracted from a model-optimised exploration path (MOEP) for a subsequent subjective rating to potentially differentiate between listeners with different attitudes towards noise suppression and introduced distortions (i.e. "noise haters" and "distortion haters"). CONCLUSIONS: By iteratively improving the agreement between subjective and objective assessment, an objective estimation of subjective traits using appropriate weightings of objective measures may become possible. This will potentially help to efficiently fit modern multidimensional hearing aid algorithms to the individual user.


Assuntos
Correção de Deficiência Auditiva/instrumentação , Auxiliares de Audição , Perda Auditiva/reabilitação , Audição , Modelos Teóricos , Pessoas com Deficiência Auditiva/reabilitação , Percepção da Fala , Estimulação Acústica , Desenho de Equipamento , Perda Auditiva/diagnóstico , Perda Auditiva/fisiopatologia , Perda Auditiva/psicologia , Testes Auditivos , Humanos , Ruído/efeitos adversos , Mascaramento Perceptivo , Pessoas com Deficiência Auditiva/psicologia , Psicoacústica , Inteligibilidade da Fala
7.
Int J Audiol ; 57(sup3): S92-S104, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-27598985

RESUMO

OBJECTIVE: Two modifications of the standardised MUlti Stimulus test with Hidden Reference and Anchor (MUSHRA), namely MUSHRA simple and MUSHRA drag&drop, were implemented and evaluated together with the original test method. The modifications were designed to maximise the accessibility of MUSHRA for elderly and technically non-experienced listeners, who constitute the typical target group in hearing aid evaluation. DESIGN: Three MUSHRA variants were assessed based on subjective and objective measures, e.g. test-retest reliability, discrimination ability, time exposure and overall preference. With each method, participants repeated the task to rate the quality of several hearing aid algorithms four times. STUDY SAMPLE: Fifty listeners grouped into five subject classes were tested, including elderly and technically non-experienced participants with normal and impaired hearing. Normal-hearing, technically experienced students served as controls. RESULTS: Both modifications can be used to obtain compatible rating results. Both were preferred over the classical MUSHRA procedure. Technically experienced listeners performed best with the modification MUSHRA drag&drop. CONCLUSIONS: The comprehensive comparison of the MUSHRA variants demonstrates that the intuitive modification MUSHRA drag&drop can be generally recommended. However, considering e.g. specific evaluation demands, we suggest a differentiated and careful application of listening test methods.


Assuntos
Audiologia/métodos , Percepção Auditiva , Correção de Deficiência Auditiva/instrumentação , Auxiliares de Audição , Perda Auditiva/diagnóstico , Perda Auditiva/reabilitação , Testes Auditivos/métodos , Audição , Pessoas com Deficiência Auditiva/reabilitação , Estimulação Acústica , Adulto , Idoso , Limiar Auditivo , Estudos de Casos e Controles , Desenho de Equipamento , Feminino , Perda Auditiva/fisiopatologia , Perda Auditiva/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Pessoas com Deficiência Auditiva/psicologia , Valor Preditivo dos Testes , Psicoacústica , Reprodutibilidade dos Testes , Adulto Jovem
8.
Trends Hear ; 192015 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-26721920

RESUMO

In a collaborative research project, several monaural and binaural noise reduction algorithms have been comprehensively evaluated. In this article, eight selected noise reduction algorithms were assessed using instrumental measures, with a focus on the instrumental evaluation of speech intelligibility. Four distinct, reverberant scenarios were created to reflect everyday listening situations: a stationary speech-shaped noise, a multitalker babble noise, a single interfering talker, and a realistic cafeteria noise. Three instrumental measures were employed to assess predicted speech intelligibility and predicted sound quality: the intelligibility-weighted signal-to-noise ratio, the short-time objective intelligibility measure, and the perceptual evaluation of speech quality. The results show substantial improvements in predicted speech intelligibility as well as sound quality for the proposed algorithms. The evaluated coherence-based noise reduction algorithm was able to provide improvements in predicted audio signal quality. For the tested single-channel noise reduction algorithm, improvements in intelligibility-weighted signal-to-noise ratio were observed in all but the nonstationary cafeteria ambient noise scenario. Binaural minimum variance distortionless response beamforming algorithms performed particularly well in all noise scenarios.


Assuntos
Algoritmos , Percepção Auditiva/fisiologia , Auxiliares de Audição , Perda Auditiva Neurossensorial/terapia , Ruído/prevenção & controle , Inteligibilidade da Fala/fisiologia , Acústica/instrumentação , Limiar Auditivo/fisiologia , Perda Auditiva Neurossensorial/diagnóstico , Humanos , Percepção Sonora/fisiologia , Razão Sinal-Ruído
9.
Trends Hear ; 192015 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-26721922

RESUMO

A comprehensive evaluation of eight signal pre-processing strategies, including directional microphones, coherence filters, single-channel noise reduction, binaural beamformers, and their combinations, was undertaken with normal-hearing (NH) and hearing-impaired (HI) listeners. Speech reception thresholds (SRTs) were measured in three noise scenarios (multitalker babble, cafeteria noise, and single competing talker). Predictions of three common instrumental measures were compared with the general perceptual benefit caused by the algorithms. The individual SRTs measured without pre-processing and individual benefits were objectively estimated using the binaural speech intelligibility model. Ten listeners with NH and 12 HI listeners participated. The participants varied in age and pure-tone threshold levels. Although HI listeners required a better signal-to-noise ratio to obtain 50% intelligibility than listeners with NH, no differences in SRT benefit from the different algorithms were found between the two groups. With the exception of single-channel noise reduction, all algorithms showed an improvement in SRT of between 2.1 dB (in cafeteria noise) and 4.8 dB (in single competing talker condition). Model predictions with binaural speech intelligibility model explained 83% of the measured variance of the individual SRTs in the no pre-processing condition. Regarding the benefit from the algorithms, the instrumental measures were not able to predict the perceptual data in all tested noise conditions. The comparable benefit observed for both groups suggests a possible application of noise reduction schemes for listeners with different hearing status. Although the model can predict the individual SRTs without pre-processing, further development is necessary to predict the benefits obtained from the algorithms at an individual level.


Assuntos
Perda Auditiva/diagnóstico , Audição/fisiologia , Ruído/prevenção & controle , Inteligibilidade da Fala , Percepção da Fala/fisiologia , Adulto , Análise de Variância , Audiometria de Tons Puros , Percepção Auditiva/fisiologia , Limiar Auditivo/fisiologia , Estudos de Casos e Controles , Feminino , Auxiliares de Audição , Perda Auditiva/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Psicoacústica , Valores de Referência , Testes de Discriminação da Fala , Adulto Jovem
10.
Paleoceanography ; 28(4): 726-739, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26074663

RESUMO

We explore the impact of a latitudinal shift in the westerly wind belt over the Southern Ocean on the Atlantic meridional overturning circulation (AMOC) and on the carbon cycle for Last Glacial Maximum background conditions using a state-of-the-art ocean general circulation model. We find that a southward (northward) shift in the westerly winds leads to an intensification (weakening) of no more than 10% of the AMOC. This response of the ocean physics to shifting winds agrees with other studies starting from preindustrial background climate, but the responsible processes are different. In our setup changes in AMOC seemed to be more pulled by upwelling in the south than pushed by downwelling in the north, opposite to what previous studies with different background climate are suggesting. The net effects of the changes in ocean circulation lead to a rise in atmospheric pCO2 of less than 10 µatm for both northward and southward shift in the winds. For northward shifted winds the zone of upwelling of carbon- and nutrient-rich waters in the Southern Ocean is expanded, leading to more CO2outgassing to the atmosphere but also to an enhanced biological pump in the subpolar region. For southward shifted winds the upwelling region contracts around Antarctica, leading to less nutrient export northward and thus a weakening of the biological pump. These model results do not support the idea that shifts in the westerly wind belt play a dominant role in coupling atmospheric CO2 rise and Antarctic temperature during deglaciation suggested by the ice core data.

11.
J Am Coll Cardiol ; 55(7): 637-42, 2010 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-20170788

RESUMO

OBJECTIVES: We sought to assess whether emotional stress-induced acute coronary syndrome (ACS) is mediated by increased inflammatory and vasoconstrictive mediators. BACKGROUND: The World Cup soccer 2006 has been shown to provoke levels of stress sufficient to increase the incidence of ACS. However, the mechanisms by which stress translates into vascular injury up to plaque rupture still remain elusive. METHODS: Serum levels of soluble CD40L (sCD40L), soluble vascular cell adhesion molecule (sVCAM)-1, monocyte chemoattractant protein (MCP)-1, tumor necrosis factor (TNF)-alpha, high-sensitivity C-reactive protein (hsCRP), regulated on activation, normal T-cell expressed and secreted (RANTES), and endothelin (ET)-1 were determined in patients who experienced an ACS during World Cup matches, in ACS reference patients (not associated with emotional stress), and in healthy volunteers. Correlations and receiver-operating characteristic curves were calculated to develop multivariable analysis and to investigate the diagnostic value of each parameter. RESULTS: The sCD40L, sVCAM-1, MCP-1, TNF-alpha, and ET-1 were significantly higher in study patients compared with the reference group. The hsCRP was similar in both groups, whereas RANTES was decreased in study patients. A positive correlation was found between ET-1 and soccer-induced enhanced levels of sCD40L, sVCAM-1, MCP-1, and TNF-alpha. Receiver-operating characteristic analysis displayed high performance of both MCP-1 and ET-1 as a measure to discriminate between stress-induced ACS and ACS controls. CONCLUSIONS: Stress-induced ACS is associated with a profound increase of inflammatory and vasoconstrictive mediators. The evaluation of a targeted drug delivery, such as anti-inflammatory agents, ET-1 receptor antagonists, or inhibition of endothelin-converting enzyme is warranted to reduce stress-mediated cardiovascular morbidity.


Assuntos
Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/psicologia , Aniversários e Eventos Especiais , Estresse Psicológico/sangue , Proteína C-Reativa/análise , Ligante de CD40/sangue , Estudos de Casos e Controles , Quimiocina CCL2/sangue , Quimiocina CCL5/sangue , Endotelina-1/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade , Futebol , Fator de Necrose Tumoral alfa/sangue , Molécula 1 de Adesão de Célula Vascular/sangue
12.
N Engl J Med ; 358(5): 475-83, 2008 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-18234752

RESUMO

BACKGROUND: The Fédération Internationale de Football Association (FIFA) World Cup, held in Germany from June 9 to July 9, 2006, provided an opportunity to examine the relation between emotional stress and the incidence of cardiovascular events. METHODS: Cardiovascular events occurring in patients in the greater Munich area were prospectively assessed by emergency physicians during the World Cup. We compared those events with events that occurred during the control period: May 1 to June 8 and July 10 to July 31, 2006, and May 1 to July 31 in 2003 and 2005. RESULTS: Acute cardiovascular events were assessed in 4279 patients. On days of matches involving the German team, the incidence of cardiac emergencies was 2.66 times that during the control period (95% confidence interval [CI], 2.33 to 3.04; P<0.001); for men, the incidence was 3.26 times that during the control period (95% CI, 2.78 to 3.84; P<0.001), and for women, it was 1.82 times that during the control period (95% CI, 1.44 to 2.31; P<0.001). Among patients with coronary events on days when the German team played, the proportion with known coronary heart disease was 47.0%, as compared with 29.1% of patients with events during the control period. On those days, the highest average incidence of events was observed during the first 2 hours after the beginning of each match. A subanalysis of serious events during that period, as compared with the control period, showed an increase in the incidence of myocardial infarction with ST-segment elevation by a factor of 2.49 (95% CI, 1.47 to 4.23), of myocardial infarction without ST-segment elevation or unstable angina by a factor of 2.61 (95% CI, 2.22 to 3.08), and of cardiac arrhythmia causing major symptoms by a factor of 3.07 (95% CI, 2.32 to 4.06) (P<0.001 for all comparisons). CONCLUSIONS: Viewing a stressful soccer match more than doubles the risk of an acute cardiovascular event. In view of this excess risk, particularly in men with known coronary heart disease, preventive measures are urgently needed.


Assuntos
Síndrome Coronariana Aguda/epidemiologia , Arritmias Cardíacas/epidemiologia , Futebol/psicologia , Estresse Psicológico/complicações , Idoso , Angina Instável/epidemiologia , Doença das Coronárias/complicações , Feminino , Alemanha , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Distribuição de Poisson , Estudos Prospectivos , Análise de Regressão
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