Diana Chavez - Academia.edu (original) (raw)

Papers by Diana Chavez

Research paper thumbnail of Impact of Suspended Solids and Organic Matter on Chlorine and UV Disinfection Efficiency of Greywater

Water

Reusing greywater (GW) can lower domestic water consumption. However, the GW must be treated and ... more Reusing greywater (GW) can lower domestic water consumption. However, the GW must be treated and disinfected for securing user health. This research studied at the laboratory scale, and in flow-through setups, which are generally used in full-scale GW treatment the disinfection efficiency of the two commonly used technologies (a) chlorination and (b) low-pressure UV irradiation. The disinfection methods were studied under a commonly found range of total suspended solids (TSS; 3.9–233 mg/L) and 5-d biochemical oxygen demand (BOD5) concentrations (0–107 mg/L) as a representative/proxy of bioavailable organic matter. The negative effect of TSS began even at low concentrations (<20 mg/L) and increased consistently with increasing TSS concentrations across all the concentrations tested. On the other hand, the negative effect of BOD5 on FC inactivation was observed only when its concentration was higher than 50 mg/L. Multiple linear regression models were developed following the labora...

Research paper thumbnail of Clinical Features of Late-onset Semantic Dementia

Cognitive and Behavioral Neurology

Research paper thumbnail of Bilingualism Delays Expression of Alzheimer’s Clinical Syndrome

Dementia and Geriatric Cognitive Disorders

Objective: To evaluate the effects of bilingualism on the emergence of Alzheimer's clinical syndr... more Objective: To evaluate the effects of bilingualism on the emergence of Alzheimer's clinical syndrome. Background: Studies have proposed an increase in cognitive and neural reserve from the management and control of two languages, with a consequent delayed expression of dementia. Methods: In a clinic with a large immigrant population, we identified 253 patients with probable Alzheimer's disease (AD) with intermediate or high evidence of AD pathophysiological process. These patients were reviewed for demographic variables, native language (L1) other than English, ages of onset and presentation, Mini-Mental State Examination (MMSE), digit spans, word fluencies, naming, and memory. Results: Among these patients, 74 (29.2%) were bilinguals with various L1s (Farsi, Spanish, Chinese, Tagalog, Arabic, others). When compared to the 179 monolingual AD patients, those who were bilingual had significant delays in ages of onset and presentation of approximately 4 years (p = 0.003). These delays persisted despite bilinguals having worse MMSE scores on presentation. There were no significant group differences on other variables except for worse naming in English among bilinguals versus monolinguals. Caregiver/informants reported that 66 (89.2%) of the 74 bilingual AD patients had gradually regressed to the predominant use of their L1. Conclusions: In line with published reports worldwide, we found that bilingualism delays the expression of Alzheimer's clinical syndrome. We also found frequent reversion to the first learned language. These findings suggest that, among bilinguals, the availability of an L1 "back-up" either facilitates compensation or masks emergence of the early symptoms of dementia.

Research paper thumbnail of Language Loss in Bilingual Patients with Alzheimer’s Disease: A Pilot Study

Research paper thumbnail of Neuropsychological Similarities and Differences Between Amnestic Alzheimer’s Disease and its Non-Amnestic Variants

Journal of Alzheimer's Disease

Research paper thumbnail of The Left Parietal Variant of Early-Onset Alzheimer’s Disease

Research paper thumbnail of Repetitive Behaviors in Frontotemporal Dementia: Compulsions or Impulsions?

The Journal of Neuropsychiatry and Clinical Neurosciences

Research paper thumbnail of The HIRAN domain of helicase-like transcription factor positions the DNA translocase motor to drive efficient DNA fork regression

The Journal of biological chemistry, Jan 11, 2018

Helicase-like transcription factor (HLTF) is a central mediator of the DNA damage response and ma... more Helicase-like transcription factor (HLTF) is a central mediator of the DNA damage response and maintains genome stability by regressing stalled replication forks. The N-terminal HIRAN domain binds specifically to the 3'-end of single-stranded DNA (ssDNA), and disrupting this function interferes with fork regression in vitro as well as replication fork progression in cells under replication stress. Here, we investigated the mechanism by which the HIRAN ssDNA interaction facilitates fork remodeling. Our results indicated that HIRAN capture of a denatured nascent leading 3'-end directs specific binding of HLTF to forks. DNase footprinting revealed that HLTF binds to the parental duplex ahead of the fork and at the leading edge behind the fork. Moreover, we found that the HIRAN domain is important for initiating regression of forks when both nascent strands are at the junction but is dispensable when forks contain ssDNA regions on either template strand. We also found that HLTF ...

Research paper thumbnail of Determinantes del nivel de endeudamiento de las empresas peruanas listadas: evidencia empírica para el período 2001-2007

Apuntes: Revista de Ciencias Sociales

Determinantes del nivel de endeudamiento de las empresas peruanas listadas: evidencia empírica...

Research paper thumbnail of Viscoelastic Properties of Extracellular Polymeric Substances Can Strongly Affect Their Washing Efficiency from Reverse Osmosis Membranes

Environmental Science & Technology, 2016

Research paper thumbnail of Efectos de la células de Shwann en la regeneración de tejido nervioso

Research paper thumbnail of Delimitación conceptual de la figura de la delegación contractual propuesta de delegación extensiva a la luz de la delegación contractual

Research paper thumbnail of Estrategias de marketing para la creación de una hostería turística en la parroquia Río Verde, provincia de Tungurahua para satisfacer al turismo nacional y receptivo

El Ecuador es un país muy rico en recursos naturales, tiene una gran diversidad en flora y fauna,... more El Ecuador es un país muy rico en recursos naturales, tiene una gran diversidad en flora y fauna, que no han sido explotados adecuadamente. La tendencia del turismo en la actualidad ha cambiado hacia lo natural, lo ecológico, por esta razón nuestro país ha ...

Research paper thumbnail of Prueba de vida

Medicina Narrativa, Mar 12, 2015

Research paper thumbnail of Interacciones moleculares de la antennapedia con factores generales de la maquinaria de transcripción basal y homeoproteínas en la regulación transcripcional

Research paper thumbnail of El pesimismo illustrado de Kant y las políticas de la Ilustración

Pensamiento Revista De Investigacion E Informacion Filosofica, 2009

Research paper thumbnail of Creación De Una Planta Artesanal De Biofermentos en La Comuna Cerezal Bellavista De La Provincia De Santa Elena, Año 2013

Research paper thumbnail of Creación de cuentos infantiles de las fechas cívicas del Ecuador para niños/as de 4 a 5 años

Research paper thumbnail of Modelos para la valorización del riesgo financiero

Apuntes Contables, Nov 10, 2010

Research paper thumbnail of PHB Production in Microalgae coupled to a Wastewater Treatment

Research paper thumbnail of Impact of Suspended Solids and Organic Matter on Chlorine and UV Disinfection Efficiency of Greywater

Water

Reusing greywater (GW) can lower domestic water consumption. However, the GW must be treated and ... more Reusing greywater (GW) can lower domestic water consumption. However, the GW must be treated and disinfected for securing user health. This research studied at the laboratory scale, and in flow-through setups, which are generally used in full-scale GW treatment the disinfection efficiency of the two commonly used technologies (a) chlorination and (b) low-pressure UV irradiation. The disinfection methods were studied under a commonly found range of total suspended solids (TSS; 3.9–233 mg/L) and 5-d biochemical oxygen demand (BOD5) concentrations (0–107 mg/L) as a representative/proxy of bioavailable organic matter. The negative effect of TSS began even at low concentrations (<20 mg/L) and increased consistently with increasing TSS concentrations across all the concentrations tested. On the other hand, the negative effect of BOD5 on FC inactivation was observed only when its concentration was higher than 50 mg/L. Multiple linear regression models were developed following the labora...

Research paper thumbnail of Clinical Features of Late-onset Semantic Dementia

Cognitive and Behavioral Neurology

Research paper thumbnail of Bilingualism Delays Expression of Alzheimer’s Clinical Syndrome

Dementia and Geriatric Cognitive Disorders

Objective: To evaluate the effects of bilingualism on the emergence of Alzheimer's clinical syndr... more Objective: To evaluate the effects of bilingualism on the emergence of Alzheimer's clinical syndrome. Background: Studies have proposed an increase in cognitive and neural reserve from the management and control of two languages, with a consequent delayed expression of dementia. Methods: In a clinic with a large immigrant population, we identified 253 patients with probable Alzheimer's disease (AD) with intermediate or high evidence of AD pathophysiological process. These patients were reviewed for demographic variables, native language (L1) other than English, ages of onset and presentation, Mini-Mental State Examination (MMSE), digit spans, word fluencies, naming, and memory. Results: Among these patients, 74 (29.2%) were bilinguals with various L1s (Farsi, Spanish, Chinese, Tagalog, Arabic, others). When compared to the 179 monolingual AD patients, those who were bilingual had significant delays in ages of onset and presentation of approximately 4 years (p = 0.003). These delays persisted despite bilinguals having worse MMSE scores on presentation. There were no significant group differences on other variables except for worse naming in English among bilinguals versus monolinguals. Caregiver/informants reported that 66 (89.2%) of the 74 bilingual AD patients had gradually regressed to the predominant use of their L1. Conclusions: In line with published reports worldwide, we found that bilingualism delays the expression of Alzheimer's clinical syndrome. We also found frequent reversion to the first learned language. These findings suggest that, among bilinguals, the availability of an L1 "back-up" either facilitates compensation or masks emergence of the early symptoms of dementia.

Research paper thumbnail of Language Loss in Bilingual Patients with Alzheimer’s Disease: A Pilot Study

Research paper thumbnail of Neuropsychological Similarities and Differences Between Amnestic Alzheimer’s Disease and its Non-Amnestic Variants

Journal of Alzheimer's Disease

Research paper thumbnail of The Left Parietal Variant of Early-Onset Alzheimer’s Disease

Research paper thumbnail of Repetitive Behaviors in Frontotemporal Dementia: Compulsions or Impulsions?

The Journal of Neuropsychiatry and Clinical Neurosciences

Research paper thumbnail of The HIRAN domain of helicase-like transcription factor positions the DNA translocase motor to drive efficient DNA fork regression

The Journal of biological chemistry, Jan 11, 2018

Helicase-like transcription factor (HLTF) is a central mediator of the DNA damage response and ma... more Helicase-like transcription factor (HLTF) is a central mediator of the DNA damage response and maintains genome stability by regressing stalled replication forks. The N-terminal HIRAN domain binds specifically to the 3'-end of single-stranded DNA (ssDNA), and disrupting this function interferes with fork regression in vitro as well as replication fork progression in cells under replication stress. Here, we investigated the mechanism by which the HIRAN ssDNA interaction facilitates fork remodeling. Our results indicated that HIRAN capture of a denatured nascent leading 3'-end directs specific binding of HLTF to forks. DNase footprinting revealed that HLTF binds to the parental duplex ahead of the fork and at the leading edge behind the fork. Moreover, we found that the HIRAN domain is important for initiating regression of forks when both nascent strands are at the junction but is dispensable when forks contain ssDNA regions on either template strand. We also found that HLTF ...

Research paper thumbnail of Determinantes del nivel de endeudamiento de las empresas peruanas listadas: evidencia empírica para el período 2001-2007

Apuntes: Revista de Ciencias Sociales

Determinantes del nivel de endeudamiento de las empresas peruanas listadas: evidencia empírica...

Research paper thumbnail of Viscoelastic Properties of Extracellular Polymeric Substances Can Strongly Affect Their Washing Efficiency from Reverse Osmosis Membranes

Environmental Science & Technology, 2016

Research paper thumbnail of Efectos de la células de Shwann en la regeneración de tejido nervioso

Research paper thumbnail of Delimitación conceptual de la figura de la delegación contractual propuesta de delegación extensiva a la luz de la delegación contractual

Research paper thumbnail of Estrategias de marketing para la creación de una hostería turística en la parroquia Río Verde, provincia de Tungurahua para satisfacer al turismo nacional y receptivo

El Ecuador es un país muy rico en recursos naturales, tiene una gran diversidad en flora y fauna,... more El Ecuador es un país muy rico en recursos naturales, tiene una gran diversidad en flora y fauna, que no han sido explotados adecuadamente. La tendencia del turismo en la actualidad ha cambiado hacia lo natural, lo ecológico, por esta razón nuestro país ha ...

Research paper thumbnail of Prueba de vida

Medicina Narrativa, Mar 12, 2015

Research paper thumbnail of Interacciones moleculares de la antennapedia con factores generales de la maquinaria de transcripción basal y homeoproteínas en la regulación transcripcional

Research paper thumbnail of El pesimismo illustrado de Kant y las políticas de la Ilustración

Pensamiento Revista De Investigacion E Informacion Filosofica, 2009

Research paper thumbnail of Creación De Una Planta Artesanal De Biofermentos en La Comuna Cerezal Bellavista De La Provincia De Santa Elena, Año 2013

Research paper thumbnail of Creación de cuentos infantiles de las fechas cívicas del Ecuador para niños/as de 4 a 5 años

Research paper thumbnail of Modelos para la valorización del riesgo financiero

Apuntes Contables, Nov 10, 2010

Research paper thumbnail of PHB Production in Microalgae coupled to a Wastewater Treatment