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1.
J Equine Vet Sci ; 137: 105075, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38697371

RESUMO

Placentitis is an important cause of reproductive losses in the equine industry. Many cases of clinical placentitis are not diagnosed until late in the course of the disease, and for this reason there is variability in the timing of intervention, diagnostic measurements, and treatment protocols. An 8-year-old multiparous Dutch Warmblood mare that was recently exposed to EHV-1 in the herd of origin presented for routine foaling management. Placentitis was diagnosed upon intake, and medical treatment was initiated. The mare delivered a term foal, and diagnostics for infectious etiology were unrewarding. While there were obvious clinical signs supporting a diagnosis of placentitis, histopathologic examination did not reveal active inflammatory lesions in the chorioallantois; however, severe funisitis was present. This report reviews early diagnosis and management of placentitis, demonstrates an array of classic and subtle pathologic lesions seen on microscopic examination, and discusses pathophysiology of placentitis.

2.
J Biomed Mater Res A ; 2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38644548

RESUMO

Degenerative spinal pathology is a widespread medical issue, and spine fusion surgeries are frequently performed. In this study, we fabricated an injectable bioactive click chemistry polymer cement for use in spinal fusion and bone regrowth. Taking advantages of the bioorthogonal click reaction, this cement can be crosslinked by itself eliminating the addition of a toxic initiator or catalyst, nor any external energy sources like UV light or heat. Furthermore, nano-hydroxyapatite (nHA) and microspheres carrying recombinant human bone morphogenetic protein-2 (rhBMP-2) and recombinant human vascular endothelial growth factor (rhVEGF) were used to make the cement bioactive for vascular induction and osteointegration. After implantation into a rabbit posterolateral spinal fusion (PLF) model, the cement showed excellent induction of new bone formation and bridging bone, achieving results comparable to autograft control. This is largely due to the osteogenic properties of nano-hydroxyapatite (nHA) and the released rhBMP-2 and rhVEGF growth factors. Since the availability of autograft sources is limited in clinical settings, this injectable bioactive click chemistry cement may be a promising alternative for spine fusion applications in addressing various spinal conditions.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38631978

RESUMO

AIMS: The objective of this study was to develop a two-year overall survival model for inoperable stage I-III non-small cell lung cancer (NSCLC) patients using routine radiation oncology data over a federated (distributed) learning network and evaluate the potential of decision support for curative versus palliative radiotherapy. METHODS: A federated infrastructure of data extraction, de-identification, standardisation, image analysis, and modelling was installed for seven clinics to obtain clinical and imaging features and survival information for patients treated in 2011-2019. A logistic regression model was trained for the 2011-2016 curative patient cohort and validated for the 2017-2019 cohort. Features were selected with univariate and model-based analysis and optimised using bootstrapping. System performance was assessed by the receiver operating characteristic (ROC) and corresponding area under curve (AUC), C-index, calibration metrics and Kaplan-Meier survival curves, with risk groups defined by model probability quartiles. Decision support was evaluated using a case-control analysis using propensity matching between treatment groups. RESULTS: 1655 patient datasets were included. The overall model AUC was 0.68. Fifty-eight percent of patients treated with palliative radiotherapy had a low-to-moderate risk prediction according to the model, with survival times not significantly different (p = 0.87 and 0.061) from patients treated with curative radiotherapy classified as high-risk by the model. When survival was simulated by risk group and model-indicated treatment, there was an estimated 11% increase in survival rate at two years (p < 0.01). CONCLUSION: Federated learning over multiple institution data can be used to develop and validate decision support systems for lung cancer while quantifying the potential impact of their use in practice. This paves the way for personalised medicine, where decisions can be based more closely on individual patient details from routine care.

4.
Ultrasound Med Biol ; 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38575416

RESUMO

OBJECTIVE: We have studied the use of polymethyl methacrylate (PMMA) as an alternative biopsy marker that is readily detectable with ultrasound Doppler twinkling in cases of in vitro, ex vivo, or limited duration in vivo settings. This study investigates the long-term safety and ultrasound Doppler twinkling detectability of a PMMA breast biopsy marker following local perturbations and different dwell times in a 6-mo animal experiment. METHODS: This study, which was approved by our Institutional Animal Care and Use Committee, involved three pigs and utilized various markers, including PMMA (Zimmer Biomet), 3D-printed, and Tumark Q markers. Markers were implanted at different times for each pig. Mesh material or ethanol was used to induce a local inflammatory reaction near certain markers. A semiquantitative twinkling score assessed twinkling for actionable localization during monthly ultrasounds. At the primary endpoint, ultrasound-guided localization of lymph nodes with detectable markers was performed. Following surgical resection of the localized nodes, histomorphometric analysis was conducted to evaluate for tissue ingrowth and the formation of a tissue rind around the markers. RESULTS: No adverse events occurred. Twinkling scores of all markers for all three pigs decreased gradually over time. The Q marker exhibited the highest mean twinkling score followed by the PMMA marker, PMMA with mesh, and Q with ethanol. The 3D-printed marker with mesh and PMMA with ethanol had the lowest scores. All wire-localized lymph nodes were successfully resected. Despite varying percentages of tissue rind around the markers and a significant reduction in overall twinkling (p < 0.001) over time, mean PMMA twinkling scores remained clinically actionable at 6 and 5 mo using a General Electric C1-6 probe and 9L-probe, respectively. CONCLUSIONS: In this porcine model, the PMMA marker demonstrates an acceptable safety profile. Clinically actionable twinkling aids PMMA marker detection even after 6 mo of dwell time in porcine lymph nodes. The Q marker maintained the greatest twinkling over time compared to all the other markers studied.

5.
Geohealth ; 8(3): e2023GH000991, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38487553

RESUMO

Wildfires are increasing in frequency and intensity, with significant consequences that impact human health. A scoping review was conducted to: (a) understand wildfire-related health effects, (b) identify and describe environmental exposure and health outcome data sources used to research the impacts of wildfire exposures on health, and (c) identify gaps and opportunities to leverage exposure and health data to advance research. A literature search was conducted in PubMed and a sample of 83 articles met inclusion criteria. A majority of studies focused on respiratory and cardiovascular outcomes. Hospital administrative data was the most common health data source, followed by government data sources and health surveys. Wildfire smoke, specifically fine particulate matter (PM2.5), was the most common exposure measure and was predominantly estimated from monitoring networks and satellite data. Health data were not available in real-time, and they lacked spatial and temporal coverage to study health outcomes with longer latency periods. Exposure data were often available in real-time and provided better temporal and spatial coverage but did not capture the complex mixture of hazardous wildfire smoke pollutants nor exposures associated with non-air pathways such as soil, household dust, food, and water. This scoping review of the specific health and exposure data sources used to underpin these studies provides a framework for the research community to understand: (a) the use and value of various environmental and health data sources, and (b) the opportunities for improving data collection, integration, and accessibility to help inform our understanding of wildfires and other environmental exposures.

6.
Nature ; 627(8005): 759-762, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38538936

RESUMO

The early evolution of a supernova (SN) can reveal information about the environment and the progenitor star. When a star explodes in vacuum, the first photons to escape from its surface appear as a brief, hours-long shock-breakout flare1,2, followed by a cooling phase of emission. However, for stars exploding within a distribution of dense, optically thick circumstellar material (CSM), the first photons escape from the material beyond the stellar edge and the duration of the initial flare can extend to several days, during which the escaping emission indicates photospheric heating3. Early serendipitous observations2,4 that lacked ultraviolet (UV) data were unable to determine whether the early emission is heating or cooling and hence the nature of the early explosion event. Here we report UV spectra of the nearby SN 2023ixf in the galaxy Messier 101 (M101). Using the UV data as well as a comprehensive set of further multiwavelength observations, we temporally resolve the emergence of the explosion shock from a thick medium heated by the SN emission. We derive a reliable bolometric light curve that indicates that the shock breaks out from a dense layer with a radius substantially larger than typical supergiants.

7.
ACS Appl Bio Mater ; 7(4): 2450-2459, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38500414

RESUMO

Spinal injuries or diseases necessitate effective fusion solutions, and common clinical approaches involve autografts, allografts, and various bone matrix products, each with limitations. To address these challenges, we developed an innovative moldable click chemistry polymer cement that can be shaped by hand and self-cross-linked in situ for spinal fusion. This self-cross-linking cement, enabled by the bioorthogonal click reaction, excludes the need for toxic initiators or external energy sources. The bioactivity of the cement was promoted by incorporating nanohydroxyapatite and microspheres loaded with recombinant human bone morphogenetic protein-2 and vascular endothelial growth factor, fostering vascular induction and osteointegration. The release kinetics of growth factors, mechanical properties of the cement, and the ability of the scaffold to support in vitro cell proliferation and differentiation were evaluated. In a rabbit posterolateral spinal fusion model, the moldable cement exhibited remarkable induction of bone regeneration and effective bridging of spine vertebral bodies. This bioactive moldable click polymer cement therefore presents a promising biomaterial for spinal fusion augmentation, offering advantages in safety, ease of application, and enhanced bone regrowth.


Assuntos
Durapatita , Fusão Vertebral , Animais , Coelhos , Humanos , Durapatita/farmacologia , Fator A de Crescimento do Endotélio Vascular , Polímeros , Química Click
9.
Stress Health ; : e3391, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38414157

RESUMO

Against the backdrop of the COVID-19 pandemic, workplace wellbeing is a key priority for employers. Severe market and health conditions continue to bring inevitable problems that could be reduced with the application of psychological interventions to prevent mental and physical health issues, making this study a highly pertinent and valuable contribution to the field. This paper reports the effects of a rational emotive behaviour therapy (REBT) programme on the irrational beliefs and emotional reactivity of 56 office-based sales professionals located in the northwest region of the UK. A pre-test, post-test experimental design was utilised, and a mixed model ANOVA (repeated measures) was adopted to assess changes in mean differences concerning irrational beliefs and emotional reactivity at pre and post-test stages for the intervention group, in comparison to a control group. Results indicate that those in the REBT group reported significant reductions in irrational beliefs and emotional reactivity, whilst those in the control group reported no such changes. It is recommended that future research studies consider utilizing a mixed methods design and focus on a strategic collaboration of organisational and individual level interventions for improving the psychological wellbeing and performance of sales personnel.

10.
Data Brief ; 53: 110032, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38348325

RESUMO

The North Central Asia Isotopic Database (NCAID) is an open-access dataset of stable isotope measurements from archaeological remains, spanning from the Early Neolithic until present-day in North Central Asia. With 3,143 individual entries corresponding to data accumulated over more than 20 years of research, this comprehensive dataset encompasses measurements of stable carbon and nitrogen isotopes in organic fractions from archaeological humans, animals, and plants. NCAID incorporates diverse supporting information, providing geographical information, archaeological context descriptions, and chronology. This resource facilitates research into past human lifeways, paleo-environments/climates, and animal management practices throughout North Central Asia and will be continually updated as more novel data is released.

11.
Environ Pollut ; 345: 123329, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38281572

RESUMO

The biological pathways linking lead exposure to adverse outcomes are beginning to be understood. Rodent models suggest lead exposure induces dysfunction within the hypothalamic-pituitary-adrenal (HPA) axis and glucocorticoid regulation, a primary physiological stress response system. Over time, HPA axis and glucocorticoid dysfunction has been associated with adverse neurocognitive and cardiometabolic health, much like lead exposure. This systematic review utilized PRISMA guidelines to synthesize the literature regarding associations between lead exposure and downstream effector hormones of the HPA axis, including cortisol, a glucocorticoid, and dehydroepiandrosterone (DHEA), a glucocorticoid antagonist. We additionally determined the state of the evidence regarding lead exposure and allostatic load, a measure of cumulative body burden resultant of HPA axis and glucocorticoid dysfunction. A total of 18 articles were included in the review: 16 assessed cortisol or DHEA and 3 assessed allostatic load. Generally, the few available child studies suggest a significant association between early life lead exposure and altered cortisol, potentially suggesting the impact of developmental exposure. In adulthood, only cross sectional studies were available. These reported significant associations between lead and reduced cortisol awakening response and increased cortisol reactivity, but few associations with fasting serum cortisol. Two studies reported significant associations between increasing lead exposure and allostatic load in adults and another between early life lead exposure and adolescent allostatic load. The paucity of studies examining associations between lead exposure and allostatic load or DHEA and overall heterogeneity of allostatic load measurements limit conclusions. However, these findings cautiously suggest associations between lead and dysregulation of physiological stress pathways (i.e., glucocorticoids) as seen through cortisol measurement in children and adults. Future research would help to elucidate these associations and could further examine the physiological stress pathway as a mediator between lead exposure and detrimental health outcomes.


Assuntos
Glucocorticoides , Hidrocortisona , Adulto , Criança , Adolescente , Humanos , Glucocorticoides/toxicidade , Glucocorticoides/metabolismo , Hidrocortisona/metabolismo , Chumbo/toxicidade , Chumbo/metabolismo , Sistema Hipotálamo-Hipofisário , Estudos Transversais , Sistema Hipófise-Suprarrenal/metabolismo , Estresse Fisiológico , Desidroepiandrosterona/metabolismo , Estresse Psicológico
12.
J Orthop ; 48: 52-59, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38077473

RESUMO

Background: Autologous bone grafts are currently the standard in orthopedic surgery despite limited donor sources and the prevalence of donor site morbidity. Other alternatives such as allografts are more readily available than autografts but have lower rates of graft incorporation. Methods: Here, we propose a novel graft alternative consisting of an injectable poly(propylene fumarate) (PPF) and poly(propylene fumarate-co-caprolactone) P(PF-co-CL) copolymer with a recombinant human bone morphogenetic protein-2 (rhBMP-2)/vascular epithelial growth factor (VEGF) release system accompanied by hydroxyapatite (HA). The efficacy of scaffold formulations was studied using a standard, bilateral, L-level (L5-L6) posterolateral transverse spinal fusion using New Zealand white rabbits. Rabbits were divided into 4 experimental groups: group I, negative control; group II, autograft (positive control); group III, injectable PPF scaffold with rhBMP-2/VEGF release system and HA; group IV, injectable P(PF-co-CL)scaffold with rhBMP-2/VEGF release system and HA. Spines were harvested at 6 weeks and 12 weeks after surgery, and spinal fusions were assessed using manual palpation, radiographic analysis, micro-computed tomography (µCT) assessment, and histologic analysis. Results: Of the 4 experimental groups, the injectable P(PF-co-CL) scaffold displayed superior initial strength and faster degradation than scaffolds constructed from PPF alone and facilitated the fusion of lateral processes in the rabbit standard posterolateral spinal fusion model. The results obtained from manual palpation, radiology, and µCT showed no difference between the P(PF-co-CL) group and the PPF group. However, histologic sections showed more osteogenesis with the new injectable P(PF-co-CL) scaffold. Conclusion: Injectable P(PF-co-CL) polymers showed promising spine fusion abilities in rabbits after 12 weeks of posterolateral implantation.

13.
Heliyon ; 9(9): e19947, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37809600

RESUMO

On-site sanitation systems (OSS) are a source of greenhouse gas (GHG) emissions. Although efforts have been made recently to measure and quantify emissions from septic tanks using various field-based methods, the vast majority of published literature reporting GHG emissions from OSS units (e.g., pits and tanks) is based on non-empirical evidence. This systematic review presents an overview and limitations of field-based methods used for the quantification of GHG emissions from OSS. Papers published in English were searched in three databases: Google Scholar, PubMed, and Directory of Articles and Journals. Peer-reviewed papers that reported field-based methods applied to containment units in OSS were included in this study. Only eight out of 2085 papers met the inclusion criteria with septic tanks as the sole technology reported and were thus, considered for the review. Most of the studies have been conducted in middle- and high-income countries. Field-based measurements of GHGs are conducted using a flux chamber (FC) and the most commonly used FC methods are (a) the modified simple static FC, (b) automated static FC, and (c) floating FC. Data reported in published studies do not provide sufficient information on the calibration and validation of the results from the FCs used. The complex FC designs, laborious fieldwork operations, and reliance on expensive, specialist equipment, suggest that such methods may not be suitable in Low and Middle-Income countries (LMICs), where resources and access to laboratory facilities are limited. Also, the complexity of pits and tank typology in LMICs (i.e., unstandardised designs and sizes) may be a challenge to the use of FCs with fixed dimensions and set operational conditions. The variation in the quantification methods and resulting emission rates among the studies indicates that gaps prevail in the use of existing methods. Therefore, there is still a need for a simple field-based, easily adaptable FC method with adequate calibration and validation that can help in reliably quantifying the emissions from different OSS in any LMICs.

15.
Microorganisms ; 11(9)2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37764037

RESUMO

During the COVID-19 pandemic, wastewater surveillance was widely used to monitor temporal and geographical infection trends. Using this as a foundation, a statewide program for routine wastewater monitoring of gastrointestinal pathogens was established in Oklahoma. The results from 18 months of surveillance showed that wastewater concentrations of Salmonella, Campylobacter, and norovirus exhibit similar seasonal patterns to those observed in reported human cases (F = 4-29, p < 0.05) and that wastewater can serve as an early warning tool for increases in cases, offering between one- and two-weeks lead time. Approximately one third of outbreak alerts in wastewater correlated in time with confirmed outbreaks of Salmonella or Campylobacter and our results further indicated that several outbreaks are likely to go undetected through the traditional surveillance approach currently in place. Better understanding of the true distribution and burden of gastrointestinal infections ultimately facilitates better disease prevention and control and reduces the overall socioeconomic and healthcare related impact of these pathogens. In this respect, wastewater represents a unique opportunity for monitoring infections in real-time, without the need for individual human testing. With increasing demands for sustainable and low-cost disease surveillance, the usefulness of wastewater as a long-term method for tracking infectious disease transmission is likely to become even more pronounced.

16.
Environ Res ; 235: 116647, 2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37442254

RESUMO

The biological pathways which link lead (Pb) and long-term outcomes are unclear, though rodent models and a few human studies suggest Pb may alter the body's stress response systems, which over time, can elicit dysregulated stress responses with cumulative impacts. This study examined associations between prenatal and early childhood Pb exposure and adolescent allostatic load, an index of an individual's body burden of stress in multiple biological systems, and further examined sex-based associations. Among 391 (51% male) participants in the ELEMENT birth cohort, we related trimester-specific maternal blood Pb, 1-month postpartum maternal tibia and patella Pb, and child blood Pb at 12-24 months to an allostatic load index in adolescence comprised of biomarkers of cardiovascular, metabolic, neuroendocrine, and immune function. The results were overall mixed, with prenatal exposure, particularly maternal bone Pb, being positively associated with allostatic load, and early childhood Pb showing mixed results for males and females. In adjusted Poisson regression models, 1 mcg/g increase in tibia Pb was associated with a 1% change in expected allostatic load (IRR = 1.01; 95%CI 0.99, 1.02). We found a significant Pb × sex interaction (IRR = 1.05; 95%CI 1.01, 1.10); where males saw an increasing percent change in allostatic load as 12 month Pb levels increased compared to females who saw a decreasing allostatic load. Further examination of allostatic load will facilitate the determination of potential mechanistic pathways between developmental toxicant exposures and later-in-life cardiometabolic outcomes.


Assuntos
Alostase , Chumbo , Adolescente , Pré-Escolar , Feminino , Humanos , Masculino , Gravidez , Alostase/fisiologia , Biomarcadores , Estudos de Coortes , Família , Vitaminas , Lactente
17.
Lancet Neurol ; 22(6): 517-528, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37086742

RESUMO

Traumatic brain injury (TBI) is a global health priority, associated with substantial burden. Historically conceptualised as an injury event with finite recovery, TBI is now recognised as a chronic condition that can affect multiple domains of health and function, some of which might deteriorate over time. Many people who have had a TBI remain moderately to severely disabled at 5 years, are rehospitalised up to 10 years post-injury, and have a reduced lifespan relative to the general population. Understanding TBI as a chronic disease process can be highly informative for optimising care, which has traditionally focused on acute care. Chronic brain injury care models must be informed by a holistic understanding of long-term outcomes and the factors that can affect how care needs evolve over time. The United States Traumatic Brain Injury Model Systems of Care follows up individuals with moderate-to-severe TBI for over 30 years, allowing characterisation of the chronic (2-30 years or more post injury) functional, cognitive, behavioural, and social sequelae experienced by individuals who have had a moderate-to-severe TBI and the implications for their health and quality of life. Older age, social determinants of health, and lower acute functional status are associated with post-recovery deterioration, while younger age and greater functional independence are associated with risky health behaviours, including substance misuse and re-injury. Systematically collected data on long-term outcomes across multiple domains of health and function are needed worldwide to inform the development of models for chronic disease management, including the proactive surveillance of commonly experienced health and functional challenges.


Assuntos
Lesões Encefálicas Traumáticas , Qualidade de Vida , Humanos , Estados Unidos/epidemiologia , Qualidade de Vida/psicologia , Lesões Encefálicas Traumáticas/epidemiologia , Lesões Encefálicas Traumáticas/terapia , Doença Crônica
18.
J Laryngol Otol ; 137(6): 691-696, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36999532

RESUMO

BACKGROUND: UK head and neck cancer incidence and prevalence in working-age people are increasing. Work is important for individuals and society. Head and neck cancer survivors return to work less than other cancer survivors. Treatment affects physical and psychological functioning long-term. Evidence is limited, with no UK qualitative studies. METHODS: A qualitative study was conducted, underpinned by a critical realism approach, involving semi-structured interviews with working head and neck cancer survivors. Interviews were conducted using the Microsoft Teams communication platform and interpreted using reflexive thematic analysis. RESULTS: Thirteen head and neck cancer survivors participated. Three themes were drawn from the data: changed meaning of work and identity, return-to-work experiences, and the impact of healthcare professionals on returning to work. Physical, speech and psychosocial changes affected workplace interactions, including stigmatising responses by work colleagues. CONCLUSION: Participants were challenged by returning to work. Work interactions and context influenced return-to-work success. Head and neck cancer survivors want return-to-work conversations within healthcare consultations, but perceived these as absent.


Assuntos
Sobreviventes de Câncer , Neoplasias de Cabeça e Pescoço , Humanos , Sobreviventes/psicologia , Neoplasias de Cabeça e Pescoço/terapia , Retorno ao Trabalho/psicologia , Sobreviventes de Câncer/psicologia , Local de Trabalho
19.
Artigo em Inglês | MEDLINE | ID: mdl-36768034

RESUMO

The study investigated the effect of turning frequency on survival of fecal indicator pathogens (E. coli, Enterococcus spp., Salmonella spp. and helminth eggs) during fecal sludge (FS) co-composting with sawdust. Dewatered FS was mixed with sawdust and composted on a pilot scale using different turning frequencies-i.e., 3 days (3TF), 7 days (7TF), and 14 days (14TF). Composting piles were monitored weekly for survival of fecal indicator microorganisms and evolution of selected physical and chemical characteristics for 14 weeks. Our results show that turning frequency has a statistically significant (p < 0.05) effect on pathogen inactivation in FS compost. The 3TF piles exhibited shorter pathogen inactivation periods (8 weeks) than 7TF and 14TF piles (10 weeks). Temperature-time was found to be the major factor responsible for the survival of pathogens in FS composting piles, followed by indigenous microbial activities and toxic by-products (monitored as NH4+-N). Our study findings suggest that even at low composting temperatures, the high turning frequency can enhance pathogen inactivation. This is a significant finding for composting activities in some rural areas where suitable organic solid waste for co-composting with FS to attain the recommended high thermophilic conditions could be greatly lacking.


Assuntos
Compostagem , Esgotos/química , Escherichia coli , Fezes , Salmonella , Solo
20.
PLoS One ; 18(1): e0275305, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36701328

RESUMO

Nonnative processing has been argued to reflect either reduced processing capacity or delayed timing of structural analysis compared to the extraction of lexical/semantic information. The current study simultaneously investigates timing and resource allocation through a time-frequency analysis of the intrinsic neural activity during syntactic processing in native and English-speaking nonnative speakers of French. It involved structurally constrained anaphora resolution in bi-clausal wh-filler-gap dependencies such as Quelle décision à propos de lui est-ce que Paul a dit que Lydie avait rejetée sans hésitation? 'Which decision about him did Paul say that Lydie rejected without hesitation?'. We tested the hypothesis that nonnative speakers may allocate greater resources than native speakers to the computation of syntactic representations based on the grammatical specifications encoded in lexical entries, though both native and nonnative processing involves the immediate application of structural constraints. This distinct resource allocation is likely to arise in response to higher activation thresholds for nonnative knowledge acquired after the first language grammar has been fully acquired. To examine this bias in nonnative neurocognitive processing, we manipulated the wh-filler to contain either a lexically specified noun complement such as à propos de lui 'about him' or a non-lexcially specified noun phrase modifier such as le concernant 'concerning him'. We focused on processing at the intermediate gap site, that is, the point of information exchange between the matrix and the embedded clauses by adopting a measurement window corresponding to the bridge verb dit 'said' and subordinator que 'that' introducing the embedded clause. Our results showed that structural constraints on anaphora produced event-related spectral perturbations at 13-14Hz early into the presentation of the bridge verb across groups. An interaction of structural constraints on anaphora with group was found at 18-19Hz early into the presentation of the bridge verb. In this interaction, the nonnative-speaker activity at 18-19Hz echoed the concurrent general patterns at 13-14Hz, whereas the native-speaker activity revealed distinct power at 18-19Hz and at 13-14Hz. There was no evidence of delay of structural constraints on intermediate gaps with respect to lexical access to the bridge verb and subordinator. However, nonnative speakers' allocation of power in cell assembly synchronizations of fillers and gaps at the intermediate gap site reflected the grammatical specifications lexically encoded in the fillers.


Assuntos
Idioma , Semântica , Masculino , Humanos , Linguística , Viés
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