Land conversion induced by urbanization leads to taxonomic and functional homogenization of a river macroinvertebrate metacommunity.

Conversion of forests to urban land-use in the processes of urbanization is one of the major causes of biotic homogenization (i.e., decline in beta diversity) in freshwater ecosystems, threating ecosystem functioning and services. However, empirical studies exploring urban land-use shaping patterns of taxonomic and functional beta diversities and their components in subtropical urban rivers are limited. Here, by leveraging data for 43 sampling sites from urban and forest rivers in Shenzhen, a megacity showing rapid urbanization, we determined the spatio-temporal dynamics and associated drivers of taxonomic and functional beta diversities of river macroinvertebrates. Our results showed that, from the forest to urban rivers, taxonomic beta diversity (wet: 32.9%; dry: 17.1%) declined more significantly than functional beta diversity (wet: 17.4%; dry: 9.5%) in different seasons. We further found that these compositional changes were largely driven by decreased roles of species/traits replacement. Although replacement was also dominant for taxonomic beta diversity (60.4%-68.4%) in two sets of rivers, richness difference contributed more to functional beta diversity in the urban river (52.6%-60.5%). Both deterministic and stochastic processes simultaneously affected beta diversity, with stochastic processes being more important in the urban (3.0-19.0%) than forest rivers (0.0%-3.0%). Besides, db-RDA and variation partitioning results showed that local-scale environmental variables explained considerably large fractions of variation in beta diversity. We hence recommended that biodiversity conservation should focus on improving and restoring local environmental conditions. Despite no significant seasonal differences in beta diversity were detected in this study, we found that the roles of deterministic (i.e., local-scale and land-use variables) and stochastic processes varied considerately across seasons. This result highlights the viewpoint that urban river biodiversity monitoring should go beyond one-season snapshot surveys. As the ongoing trend of urbanization in developing countries, the findings of this study are relevant in guiding urban river environmental monitoring, biodiversity conservation and land-use planning.

Effects of different types of land-use on taxonomic and functional diversity of benthic macroinvertebrates in a subtropical river network.

Expansion of agricultural and urban areas and intensification of catchment land-use increasingly affect different facets of biodiversity in aquatic communities. However, understanding the responses of taxonomic and functional diversity to specific conversion from natural forest to agriculture and urban land-use remains limited, especially in subtropical streams where biomonitoring programs and using functional traits are still under development. Here, we conducted research in a subtropical stream network to examine the responses of macroinvertebrate taxonomic and functional diversity to different types of land-use in central China. Our results showed that medium body size, univoltine, gill respiration, and slow seasonal development were much higher in natural forest sites, while certain traits related to strong resilience and resistance (e.g., small body size, fast seasonal development, bi-or multivoltine, abundant occurrence in drift, sprawler) dominated in high-intensity agriculture and urbanization sites. We further found that land-use compromised water quality (e.g., increases in total phosphate, conductivity and water temperature) and habitat conditions (e.g., high proportion of sand and silt, gravel, and channel width) accounted for the changes in trait composition based on a combination of RLQ and fourth-corner analysis. Moreover, natural forest sites presented relatively high values of functional richness than other land-use, demonstrating the importance of natural forest maintenance to promote high levels of functional diversity. However, taxonomic diversity indexes showed higher sensitivity to distinguish different types of land-use compared to functional diversity measures. Even so, given that certain trait categories showed significant relationships with specific local environmental stressors, trait-based approaches can provide reliable evidence to diagnose the cause of impairment and complement the results of the taxonomic-based approaches. Our findings support the idea that taxonomic and functional approaches should be integrated in river restoration and land-use management.

Functional responses of aquatic invertebrates to anthropogenic stressors in riparian zones of Neotropical savanna streams.

Riparian zones ensure freshwater ecosystem processes such as microclimate regulation, organic matter inputs, and fine substrate retention. These processes illustrate the importance of riparian zones for freshwater ecosystem functioning, maintaining biodiversity, and mitigating the effects of anthropogenic pressures on aquatic ecosystems. We aimed to determine the freshwater invertebrate biological traits that are most affected by anthropogenic stressors in the riparian zones of 210 Neotropical savanna headwater streams. We assessed % canopy cover over the streambed, % fine bottom substrate, % leaf pack, substrate heterogeneity, and water temperature. Firstly, we identified bioindicator taxa in response to each local metric gradient. We assessed the functional response, based on biological traits of bioindicators previously selected. We identified 324,015 specimens belonging to 84 freshwater invertebrate taxa. Fifty-one taxa (60%) were bioindicators of anthropogenic stressors. We found three main sets of traits. (1) a set of traits linked to increased disturbance (higher percentage of fine sediments), consisting of organisms with aquatic adult stages, spherical body shape, and long adult life stages. (2) A set of traits linked to lower disturbance (higher substrate heterogeneity), including taxa with short or very short lifespans that live attached to substrates. (3) A set of traits linked to higher water temperature, including organisms with short adult lifespans and lower body flexibility. These patterns suggest that the stressors act as environmental filters and do not act independently on single traits, but rather, selecting sets of biological traits that facilitate taxa surviving and persisting in local environmental conditions. Our results support the development of powerful evaluation tools for environmental managers and decision makers. Because degraded freshwater communities respond in similar ways across large biogeographic areas, these sets of traits can be used for ecological monitoring efforts along other tropical savanna headwaters worldwide.

Risk of Conversion to Dementia in a Mild Behavioral Impairment Group Compared to a Psychiatric Group and to a Mild Cognitive Impairment Group.

BACKGROUND: There is insufficient available information on behavioral changes in the absence of cognitive impairment as factors increasing the risk of conversion to dementia. OBJECTIVE: To observe and analyze patients with mild behavioral impairment (MBI), mild cognitive impairment (MCI), and a psychiatry group (PG) to compare the risk of progression to dementia. METHODS: From 677 initially assessed ≥60-year-old patients, a series of 348 patients was studied for a five-year period until censoring or conversion to dementia: 96 with MBI, 87 with MCI, and 165 with general psychiatry disorders, including 4 subgroups: Anxiety, Depression, Psychosis and Others. All patients were assessed with clinical, psychiatric, neurological, neuropsychological, and neuroimaging studies. RESULTS: From 348 patients, 126 evolved to dementia (36.2%). Conversion was significantly higher in MBI (71.5%), followed by the MCI-MBI overlap (59.6%) and MCI (37.8%) groups, compared to PG (13.9%) (Log-rank p < 0.001). MCI patients mostly converted to Alzheimer's dementia, while MBI converted to frontotemporal dementia and Lewy body dementia. Patients in PG converted to Lewy body dementia and frontotemporal dementia. CONCLUSION: Conversion to dementia is significantly higher in patients with neuropsychiatric symptoms. The MBI concept generates a new milestone in the refining of diagnosis of neurodegenerative diseases and the possibility of creating neuropsychiatric profiles. Its earlier identification will allow new possibilities for therapeutic intervention.

[A survey on biomarkers and early diagnosis in Alzheimer's disease]. / Una encuesta sobre biomarcadores y diagnóstico precoz de la enfermedad de Alzheimer.

Given the potential use of biomarkers in the diagnosis of Alzheimer's disease (AD) in early stages, new ethical and communication dilemmas appear in everyday clinical practice. The aim of this study was to know the opinion of health professionals (HP) and general public (GP) on the implementation of early diagnostic techniques in AD and the use of biomarkers for this purpose. A survey with multiple choice answers was elaborated in two versions: one for HP and the other for GP. Respondents were invited to participate through a system of mass mailing e-mail; e-mail addresses were collected from CEMIC database. A total of 1503 answers were analyzed: 807 HP and 696 GP. Most respondents, 84.7%, preferred the option of early diagnosis of AD even knowing the lack of curative treatment. Forty five percent of GP and 26.8% of HP replied that there is no ethical dilemma in the use of biomarkers and that no communication or ethical dilemma is generated to physicians when informing the diagnosis of the disease. The HP group showed more divergence in the views than the GP group. These results may indicate a change in the physician-patient relationship, showing the GP group with an active and supportive position towards the use of biomarkers for early diagnosis of AD.

Una encuesta sobre biomarcadores y diagnóstico precoz de la enfermedad de Alzheimer / A survey on biomarkers and early diagnosis in Alzheimer's disease

Ante el uso potencial de biomarcadores para el diagnóstico temprano de la enfermedad de Alzheimer (EA), nuevos dilemas éticos y de comunicación aparecen en la práctica clínica cotidiana. El objetivo de este trabajo fue conocer la opinión de profesionales de la salud (PS) y del público en general (PG) sobre la realización de técnicas diagnósticas tempranas en la EA utilizando marcadores biológicos, aun a sabiendas que hasta ahora la enfermedad es incurable. Se confeccionó una encuesta en Internet con respuesta múltiple en dos versiones: una para PS y otra para el PG. Se invitó a participar a los encuestados a través de un sistema legal de envíos masivos de correo electrónico, utilizando direcciones recolectadas en la base de datos del CEMIC. Se analizaron 1503 respuestas: 807 grupo PS y 696 grupo PG. La mayoría de los encuestados (84.7%) prefirió la opción de realizar el diagnóstico temprano de la EA aun conociendo la falta de tratamiento curativo. El 45.1% del grupo PG vs. el 26.8% del grupo PS respondió que no cree que se genere un dilema de comunicación ni ético en los médicos al informar el diagnóstico de la enfermedad. El grupo PS mostró mayor divergencia en las opiniones que el PG. Estos resultados podrían indicar una nueva dinámica en la relación médico-paciente, mostrando al PG con una posición activa y favorable frente al uso de los biomarcadores para el diagnóstico temprano de la EA.

Given the potential use of biomarkers in the diagnosis of Alzheimer’s disease (AD) in early stages, new ethical and communication dilemmas appear in everyday clinical practice. The aim of this study was to know the opinion of health professionals (HP) and general public (GP) on the implementation of early diagnostic techniques in AD and the use of biomarkers for this purpose. A survey with multiple choice answers was elaborated in two versions: one for HP and the other for GP. Respondents were invited to participate through a system of mass mailing e-mail; e-mail addresses were collected from CEMIC database. A total of 1503 answers were analyzed: 807 HP and 696 GP. Most respondents, 84.7%, preferred the option of early diagnosis of AD even knowing the lack of curative treatment. Forty five percent of GP and 26.8% of HP replied that there is no ethical dilemma in the use of biomarkers and that no communication or ethical dilemma is generated to physicians when informing the diagnosis of the disease. The HP group showed more divergence in the views than the GP group. These results may indicate a change in the physician-patient relationship, showing the GP group with an active and supportive position towards the use of biomarkers for early diagnosis of AD.

O custo econômico da doença de Alzheimer: sobrecarga familiar ou da saúde pública? / The economic cost of Alzheimers disease: family or public-health burden?

Alzheimers disease (AD) patients suffer progressive cognitive, behavioral and functional impairment which result in a heavy burden to patients, families, and the public-health system. AD entails both direct and indirect costs. Indirect costs (such as loss or reduction of income by the patient or family members) are the most important costs in early and community-dwelling AD patients. Direct costs (such as medical treatment or social services) increase when the disorder progresses, and the patient is institutionalized or a formal caregiver is required. Drug therapies represent an increase in direct cost but can reduce some other direct or indirect costs involved. Several studies have projected overall savings to society when using drug therapies and all relevant cost are considered, where results depend on specific patient and care setting characteristics. Dementia should be the focus of analysis when public health policies are being devised. South American countries should strengthen their policy and planning capabilities by gathering more local evidence about the burden of AD and how it can be shaped by treatment options.

O paciente com doença de Alzheimer (DA) sofre comprometimento progressivo cognitivo, comportamental e funcional, que resulta numa grande sobrecarga aos pacientes, familiares e à saúde pública. A DA inclui custos diretos e indiretos. Os custos indiretos (como perda ou redução dos ganhos pelo paciente ou membros da família) são os mais importantes custos dos pacientes leves e na comunidade. Os custos diretos (tais como tratamento médico ou serviços sociais) aumentam com a progressão da doença, quando o paciente é institucionalizado ou quando um cuidador formal é requerido. A terapia com drogas representam um aumento nos custos diretos, mas podem reduzir alguns outros custos diretos ou indiretos envolvidos. Vários estudos projetam uma economia global da sociedade quando é usada terapia com drogas e todos os custos relevantes são considerados; e os resultados dependerão de um paciente específico e características do meio envolvido no cuidado. A demência pode ser um assunto de análise quando as políticas de saúde são desenhadas. Os países da América do Sul deveriam fortalecer suas políticas e capacidades de planejamento, pela geração de maiores evidências locais sobre a sobrecarga da DA e como poderia ser norteada pelas opções de tratamento.

Síntomas neuropsiquiátricos en la afasia progresiva primaria / No disponible

No disponible

The economic cost of Alzheimer's disease: Family or public health burden?

Alzheimer's disease (AD) patients suffer progressive cognitive, behavioral and functional impairment which result in a heavy burden to patients, families, and the public-health system. AD entails both direct and indirect costs. Indirect costs (such as loss or reduction of income by the patient or family members) are the most important costs in early and community-dwelling AD patients. Direct costs (such as medical treatment or social services) increase when the disorder progresses, and the patient is institutionalized or a formal caregiver is required. Drug therapies represent an increase in direct cost but can reduce some other direct or indirect costs involved. Several studies have projected overall savings to society when using drug therapies and all relevant cost are considered, where results depend on specific patient and care setting characteristics. Dementia should be the focus of analysis when public health policies are being devised. South American countries should strengthen their policy and planning capabilities by gathering more local evidence about the burden of AD and how it can be shaped by treatment options.

O paciente com doença de Alzheimer (DA) sofre comprometimento progressivo cognitivo, comportamental e funcional, que resulta numa grande sobrecarga aos pacientes, familiares e à saúde pública. A DA inclui custos diretos e indiretos. Os custos indiretos (como perda ou redução dos ganhos pelo paciente ou membros da família) são os mais importantes custos dos pacientes leves e na comunidade. Os custos diretos (tais como tratamento médico ou serviços sociais) aumentam com a progressão da doença, quando o paciente é institucionalizado ou quando um cuidador formal é requerido. A terapia com drogas representam um aumento nos custos diretos, mas podem reduzir alguns outros custos diretos ou indiretos envolvidos. Vários estudos projetam uma economia global da sociedade quando é usada terapia com drogas e todos os custos relevantes são considerados; e os resultados dependerão de um paciente específico e características do meio envolvido no cuidado. A demência pode ser um assunto de análise quando as políticas de saúde são desenhadas. Os países da América do Sul deveriam fortalecer suas políticas e capacidades de planejamento, pela geração de maiores evidências locais sobre a sobrecarga da DA e como poderia ser norteada pelas opções de tratamento.