Browsing by Author "Rojas, Sandra"

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    Investigating How Age Affects Self-Perception and Voice Awareness in Parkinson's Disease
    (2025) Contreras-Ruston, Francisco; Arriagada-Concha, Héctor; Lagos Villaseca, Antonia Elisa; Rojas, Sandra; Napolitano, Carla; Kotz, Sonja; Navarra, Jordi
    Objective: Parkinson's disease (PD) presents with voice disturbances accompanied by sensory processing and awareness deficits. Sensory feedback from the voice, which is essential in speech production, is often impaired in individuals with PD (IwPD), potentially leading to such difficulties in the self-perception and awareness of voice disorder. However, aging naturally affects sensory and motor brain systems, including those involved in voice production; therefore, it remains unclear whether the combined effects of age and PD exacerbate deficits in voice self-perception and awareness deficit. This study explored how age and sensory feedback in IwPD interact and affect self-perception and awareness of voice changes. Patient-reported outcome measures (PROMs) specific to the voice may not be efficient enough to capture voice changes in IwPD. Methods: The study included three groups of similar ages: 27 IwPD (61-79 years), 25 individuals with general voice disorders (GVD, aged 57-83 years), and 28 healthy controls (HC, aged 60-80 years). Self-perception of the voice was assessed by three PROMs: the Voice Symptoms Scale, Voice Handicap Index-10, and Voice-Related Quality of Life. Voice loudness was recorded and analyzed using univariate comparisons between the PROM scores. Further, multivariate techniques, such as principal component analysis (PCA) and cluster analysis, were used to identify intergroup differences in voice quality and voice self-awareness. Results: The IwPD group showed lower self-perception and awareness of voice problems than the GVD and HC groups. Within the IwPD group, age did not show a significant impact on self-perception of voice and awareness. This group showed slightly higher PROM scores than the HCs. In contrast, the GVD group showed marked differences in all PROMs and voice parameters compared with the HC and PD groups. PCA revealed significant differences in total scores and voice loudness between the groups. Conclusions: These findings suggest that age-related changes in sensory feedback are not significant factors affecting reduced self-perception and awareness of voice changes in IwPD. PCA and cluster analysis revealed distinct patterns among the groups, with GVD forming a separate cluster and IwPD displaying variability, partially overlapping with HC and GVD. This variability underscores the limited diagnostic utility of PROMs used to identify voice problems in IwPD compared with older individuals without PD, who generally exhibit greater awareness of voice disorders. Future studies should focus on developing tailored PROMs to better capture these challenges in IwPD.
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    Investigating How Age Affects Self-Perception and Voice Awareness in Parkinson's Disease
    (2025) Contreras-Ruston, Francisco; Arriagada-Concha, Héctor; Lagos Villaseca, Antonia Elisa; Rojas, Sandra; Napolitano, Carla; Kotz, Sonja; Navarra, Jordi
    Objective: Parkinson's disease (PD) presents with voice disturbances accompanied by sensory processing and awareness deficits. Sensory feedback from the voice, which is essential in speech production, is often impaired in individuals with PD (IwPD), potentially leading to such difficulties in the self-perception and awareness of voice disorder. However, aging naturally affects sensory and motor brain systems, including those involved in voice production; therefore, it remains unclear whether the combined effects of age and PD exacerbate deficits in voice self-perception and awareness deficit. This study explored how age and sensory feedback in IwPD interact and affect self-perception and awareness of voice changes. Patient-reported outcome measures (PROMs) specific to the voice may not be efficient enough to capture voice changes in IwPD. Methods: The study included three groups of similar ages: 27 IwPD (61-79 years), 25 individuals with general voice disorders (GVD, aged 57-83 years), and 28 healthy controls (HC, aged 60-80 years). Self-perception of the voice was assessed by three PROMs: the Voice Symptoms Scale, Voice Handicap Index-10, and Voice-Related Quality of Life. Voice loudness was recorded and analyzed using univariate comparisons between the PROM scores. Further, multivariate techniques, such as principal component analysis (PCA) and cluster analysis, were used to identify intergroup differences in voice quality and voice self-awareness. Results: The IwPD group showed lower self-perception and awareness of voice problems than the GVD and HC groups. Within the IwPD group, age did not show a significant impact on self-perception of voice and awareness. This group showed slightly higher PROM scores than the HCs. In contrast, the GVD group showed marked differences in all PROMs and voice parameters compared with the HC and PD groups. PCA revealed significant differences in total scores and voice loudness between the groups. Conclusions: These findings suggest that age-related changes in sensory feedback are not significant factors affecting reduced self-perception and awareness of voice changes in IwPD. PCA and cluster analysis revealed distinct patterns among the groups, with GVD forming a separate cluster and IwPD displaying variability, partially overlapping with HC and GVD. This variability underscores the limited diagnostic utility of PROMs used to identify voice problems in IwPD compared with older individuals without PD, who generally exhibit greater awareness of voice disorders. Future studies should focus on developing tailored PROMs to better capture these challenges in IwPD.
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    Pendimethalin and oxyfluorfen degradation under two irrigation conditions over four years application
    (TAYLOR & FRANCIS INC, 2009) Alister, Claudio A.; Gomez, Patricio A.; Rojas, Sandra; Kogan, Marcelo
    A four-year field study was conducted to determine the effect of pluviometric conditions on pendimethalin and oxyfluorfen soil dynamics. Adsorption, dissipation and soil movement were studied in a sandy loam soil from 2003 to 2007. Pendimethalin and oxyfluorfen were applied every year on August at 1.33 and 0.75 kg ha-1, respectively. Herbicide soil concentrations were determined at 0, 10, 20, 40, 90 and 340 days after application (DAA), under two pluviometric regimens, natural rainfall and irrigated (30 mm every 15 days during the first 90 DAA). More than 74% of the herbicide applied was detected at the top 2.5 cm layer for both herbicides, and none was detected at 10 cm or deeper. Pendimethalin soil half-life ranged from 10.5 to 31.5 days, and was affected mainly by the time interval between application and the first rain event. Pendimethalin soil residues at 90 DAA fluctuated from 2.5 to 13.8% of the initial amount applied, and it decreased to 2.4 and 8.6% at 340 DAA. Oxyfluorfen was more persistent than pendimethalin as indicated by its soil half-life which ranged from 34.3 to 52.3 days, affected primarily by the rain amount at the first rainfall after application. Oxyfluorfen soil residues at 90 DAA ranged from 16.7 to 34.8% and it decreased to 3.3 and 17.9% at 340 DAA. Based on half-life values, herbicide soil residues after one year, and soil depth reached by the herbicides, we conclude that both herbicides should be considered as low risk to contaminate groundwater. However, herbicide concentration at the top 2.5 cm layer should be considered in cases where runoff or soil erosion could occur, because of the potential for surface water contamination.