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1.
JMIR Public Health Surveill ; 6(2): e19097, 2020 05 13.
Artículo en Inglés | MEDLINE | ID: mdl-32369029

RESUMEN

BACKGROUND: With the sensitivity of the polymerase chain reaction test used to detect the presence of the virus in the human host, the worldwide health community has been able to record a large number of the recovered population. OBJECTIVE: The aim of this study was to evaluate the probability of reinfection in the recovered class and the model equations, which exhibits the disease-free equilibrium state for the coronavirus disease. METHODS: The model differential equation was evaluated for the disease-free equilibrium for the case of reinfection as well as the existence and stability criteria for the disease, using the model proportions. This evaluation shows that the criteria for a local or worldwide asymptotic stability with a basic reproductive number (R0=0) were satisfied. Hence, there is a chance of no secondary reinfections from the recovered population, as the rate of incidence of the recovered population vanishes (ie, B=0). RESULTS: With a total of about 900,000 infected cases worldwide, numerical simulations for this study were carried out to complement the analytical results and investigate the effect that the implementation of quarantine and observation procedures has on the projection of further virus spread. CONCLUSIONS: As shown by the results, the proportion of the infected population, in the absence of a curative vaccination, will continue to grow worldwide; meanwhile, the recovery rate will continue slowly, which means that the ratio of infection rate to recovery rate will determine the death rate that is recorded. Most significant for this study is the rate of reinfection by the recovered population, which will decline to zero over time as the virus is cleared clinically from the system of the recovered class.


Asunto(s)
Simulación por Computador , Infecciones por Coronavirus/epidemiología , Coronavirus , Brotes de Enfermedades/prevención & control , Susceptibilidad a Enfermedades/epidemiología , Modelos Biológicos , Pandemias , Neumonía Viral/epidemiología , Número Básico de Reproducción , Betacoronavirus , Trazado de Contacto , Coronavirus/patogenicidad , Infecciones por Coronavirus/transmisión , Salud Global , Humanos , Incidencia , Aislamiento de Pacientes , Neumonía Viral/transmisión , Probabilidad , Cuarentena , Distancia Social
2.
Epidemiol Infect ; 148: e97, 2020 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-32418559

RESUMEN

Back-projection is an epidemiological analysis method that was developed to estimate HIV incidence using surveillance data on AIDS diagnoses. It was used extensively during the 1990s for this purpose as well as in other epidemiological contexts. Surveillance data on COVID-19 diagnoses can be analysed by the method of back-projection using information about the probability distribution of the time between infection and diagnosis, which is primarily determined by the incubation period. This paper demonstrates the value of such analyses using daily diagnoses from Australia. It is shown how back-projection can be used to assess the pattern of COVID-19 infection incidence over time and to assess the impact of control measures by investigating their temporal association with changes in incidence patterns. For Australia, these analyses reveal that peak infection incidence coincided with the introduction of border closures and social distancing restrictions, while the introduction of subsequent social distancing measures coincided with a continuing decline in incidence to very low levels. These associations were not directly discernible from the daily diagnosis counts, which continued to increase after the first stage of control measures. It is estimated that a one week delay in peak incidence would have led to a fivefold increase in total infections. Furthermore, at the height of the outbreak, half to three-quarters of all infections remained undiagnosed. Automated data analytics of routinely collected surveillance data are a valuable monitoring tool for the COVID-19 pandemic and may be useful for calibrating transmission dynamics models.


Asunto(s)
Infecciones por Coronavirus/epidemiología , Neumonía Viral/epidemiología , Infecciones Asintomáticas/epidemiología , Australia/epidemiología , Betacoronavirus , Control de Enfermedades Transmisibles/métodos , Control de Enfermedades Transmisibles/estadística & datos numéricos , Infecciones por Coronavirus/diagnóstico , Humanos , Incidencia , Modelos Estadísticos , Pandemias/estadística & datos numéricos , Neumonía Viral/diagnóstico , Probabilidad
4.
Science ; 368(6491)2020 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-32234805

RESUMEN

The newly emergent human virus SARS-CoV-2 (severe acute respiratory syndrome-coronavirus 2) is resulting in high fatality rates and incapacitated health systems. Preventing further transmission is a priority. We analyzed key parameters of epidemic spread to estimate the contribution of different transmission routes and determine requirements for case isolation and contact tracing needed to stop the epidemic. Although SARS-CoV-2 is spreading too fast to be contained by manual contact tracing, it could be controlled if this process were faster, more efficient, and happened at scale. A contact-tracing app that builds a memory of proximity contacts and immediately notifies contacts of positive cases can achieve epidemic control if used by enough people. By targeting recommendations to only those at risk, epidemics could be contained without resorting to mass quarantines ("lockdowns") that are harmful to society. We discuss the ethical requirements for an intervention of this kind.


Asunto(s)
Betacoronavirus , Teléfono Celular , Trazado de Contacto/métodos , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/transmisión , Aplicaciones Móviles , Pandemias/prevención & control , Neumonía Viral/prevención & control , Neumonía Viral/transmisión , Algoritmos , Enfermedades Asintomáticas , Número Básico de Reproducción , China/epidemiología , Trazado de Contacto/ética , Infecciones por Coronavirus/epidemiología , Epidemias/prevención & control , Humanos , Control de Infecciones , Aplicaciones Móviles/ética , Modelos Teóricos , Neumonía Viral/epidemiología , Probabilidad , Cuarentena , Factores de Tiempo
6.
Water Res ; 178: 115801, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32348931

RESUMEN

Limnologists often adhere to a discretized view of waterbodies-they classify them, divide them into zones, promote discrete management targets, and use research tools, experimental designs, and statistical analyses focused on discretization. By offering useful shortcuts, this approach to limnology has profoundly benefited the way we understand, manage, and communicate about waterbodies. But the research questions and the research tools in limnology are changing rapidly in the era of big data, with consequences for the relevance of our current discretization schemes. Here, I examine how and why we discretize and argue that selectively rethinking the extent to which we must discretize gives us an exceptional chance to advance limnology in new ways. To help us decide when to discretize, I offer a framework (discretization evaluation framework) that can be used to compare the usefulness of various discretization approaches to an alternative which relies less on discretization. This framework, together with a keen awareness of discretization's advantages and disadvantages, may help limnologists benefit from the ongoing information explosion.


Asunto(s)
Explosiones , Limnología , Probabilidad
7.
Environ Monit Assess ; 192(4): 225, 2020 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-32152889

RESUMEN

Exposure to toxic contaminants in the environment harms human and animal health and disturbs the integrity and function of the impacted ecosystem. The impact could be local, regional, and global. The concentration of a toxic substance below or above detection limits or thresholds in environmental samples is frequently recorded as non-detect. We discuss inferences based on exact and modified likelihood methods for the location-scale family with values below the detection limit, and as a special case for the normal distribution with a comparison between the methods. We demonstrate the procedure using Niagara River monitoring data.


Asunto(s)
Ecosistema , Monitoreo del Ambiente , Contaminantes Ambientales , Animales , Interpretación Estadística de Datos , Humanos , Probabilidad , Ríos
8.
Environ Monit Assess ; 191(Suppl 4): 816, 2020 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-32185513

RESUMEN

We estimated detection probabilities of bird carcasses along sandy beaches and in marsh edge habitats in the northern Gulf of Mexico to help inform models of bird mortality associated with the Deepwater Horizon oil spill. We also explored factors that may influence detection probability, such as carcass size, amount of scavenging, location on the beach, habitat type, and distance into the marsh. Detection probability for medium-sized carcasses (200-500 g) ranged from 0.82 (SE = 0.09) to 0.93 (SE = 0.04) along sandy beaches. Within sandy beaches, we found that intact/slightly scavenged carcasses were easier to detect than heavily scavenged ones and did not find strong effects of location on the beach on detection probability. We estimated detection rate for each combination of scavenging state, carcass size, and position along sandy beaches. In marsh edge habitats, detection ranged from 0.04 (SE = 0.04) to 0.86 (SE = 0.10), with detection rates rapidly increasing from small (< 200 g) to medium carcass sizes and leveling off between medium and extra-large (> 1000 g) carcasses regardless of vegetation type (Spartina or Phragmites). Carcasses of all sizes were generally harder to locate in Spartina-dominated marshes than in Phragmites-dominated ones. A subset of the data for which we could adequately assess the effect of distance into the marsh indicated that detection rates generally declined the farther a carcass was into marsh vegetation. Based on power analyses, our ability to identify predictors that influence detection rates would be higher with larger numbers of carcasses, greater numbers of search trials per carcass, or more balanced sampling distributions across predictor values.


Asunto(s)
Aves , Contaminación por Petróleo , Humedales , Animales , Cadáver , Monitoreo del Ambiente , Golfo de México , Probabilidad
9.
Environ Monit Assess ; 191(Suppl 4): 813, 2020 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-32185545

RESUMEN

During a marine oil spill, injured birds often die on the water, some eventually washing ashore, but others becoming waterlogged and sinking or being scavenged before reaching the shoreline. Birds that disappear before they can be deposited on the shoreline are difficult to enumerate, but they commonly represent a large fraction of total oil spill-related mortality. As part of the process of quantifying the overall impact to seabirds resulting from the Deepwater Horizon oil spill, it was necessary to estimate the number of dead birds lost at sea. We conducted a study to estimate the beaching probability of birds that died at sea in the Gulf of Mexico in the areas most heavily used by seabirds and impacted by the spill. Using a mark-recapture analysis to derive the beaching probability from our field study data, we estimated that dead birds afloat at sea had about a 0.1414 probability of beaching in areas searched during the Deepwater Horizon oil spill. Sensitivity analyses of our model and requisite assumptions suggested that if our assumptions were violated, the "true" beaching probability could be anywhere between 0.11 and 0.16. These estimates are much lower than beaching probabilities estimated for seabirds killed during the Exxon Valdez oil spill in the waters of Alaska, for example, likely reflect higher rates of decomposition and scavenging in the warmer waters of the Gulf of Mexico. Our estimate suggests that bird carcasses that washed onshore during the Deepwater Horizon oil spill represented only 14% of those killed at sea during the spill.


Asunto(s)
Aves , Contaminación por Petróleo , Contaminantes Químicos del Agua , Alaska , Animales , Monitoreo del Ambiente , Golfo de México , Mortalidad , Dinámica Poblacional , Probabilidad , Contaminantes Químicos del Agua/toxicidad
10.
Bull Cancer ; 107(4): 410-416, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32145962

RESUMEN

Tumor profiling has been shown to benefit patients with rare or refractory metastatic cancer, but several limitations hamper its use in daily clinical practice. We aim to assess the added benefit of a comprehensive tumor profiling, including factors predictive of response to targeted and cytotoxic therapy, in the treatment of refractory or rare solid tumors outside of a formal clinical trial. Patients were included between 2013 and 2017. Multiplatform comprehensive tumor profiling (CTP) was performed on FFPE specimens. Tumor response was evaluated by imaging using the RECIST criteria version 1.1. The PFS ratio was defined as PFS under CTP-guided therapy (PFS2)/PFS under previous standard therapy (PFS1). A clinical benefit was identified if the PFS ratio exceeded the 1.3 threshold value. In total, 184 patients were enrolled among whom 104 were evaluable for the PFS ratio. Objective response rates (ORR) were equal to 25% (CI95: 16.6-33.4%) and 36.5% (CI95: 27.2-45.8%) on the last therapy before CTP and on the CTP-guided therapy respectively (P-value=0.058 on paired proportion comparison test). The proportion of patients achieving a PFS2/PFS1 ratio≥1.3 was equal to 50%. The median PFS1 was statistically lower than PFS2 (120 days compared to 184 days respectively, P-value log rank 0.01). These results confirm the feasibility and the added benefit of a CTP in patients with refractory tumors in daily clinical practice especially in patients not able to enter a clinical trial.


Asunto(s)
Antineoplásicos/uso terapéutico , Terapia Molecular Dirigida/métodos , Proteínas de Neoplasias/genética , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Enfermedades Raras/tratamiento farmacológico , Enfermedades Raras/genética , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/antagonistas & inhibidores , Toma de Decisiones Clínicas , Estudios de Factibilidad , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Inmunohistoquímica , Hibridación in Situ/métodos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Mutación , Proteínas de Neoplasias/análisis , Proteínas de Neoplasias/antagonistas & inhibidores , Neoplasias/mortalidad , Probabilidad , Supervivencia sin Progresión , Análisis por Matrices de Proteínas/métodos , Enfermedades Raras/mortalidad , Criterios de Evaluación de Respuesta en Tumores Sólidos , Tasa de Supervivencia , Adulto Joven
11.
PLoS One ; 15(3): e0216147, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32155154

RESUMEN

BACKGROUND: Fourteen previous meta-analyses have been published to analyze the polymorphisms of individual GSTM1 present/null, GSTT1 present/null, and GSTP1 IIe105Val on breast cancer (BC) risk. However, their meta-analyses did not explore the combined effects of the three genetic polymorphisms on BC risk. In addition, they did not evaluate the credibility of statistically significant associations. Furthermore, a multitude of new articles have been published on these themes, and therefore a meta-analysis and re-analysis of systematic previous meta-analyses were performed to further explore these issues. OBJECTIVES: To determine the association between the individual and combined effects of GSTM1, GSTT1, and GSTP1 polymorphisms on breast cancer risk. METHODS: Crude odds ratios (ORs) and their 95% confidence intervals (CIs) were applied to estimate the association between individual and combined effects of GSTM1, GSTT1, and GSTP1 polymorphisms on BC risk. To evaluate the credibility of statistically significant associations in the current and previous meta-analyses, we applied the the false-positive report probabilities (FPRP) test and the Venice criteria. RESULTS: 101 publications were selected to evaluate the individual and combined effects of GSTM1, GSTT1 and GSTP1 polymorphisms on BC risk. Overall, statistically significant elevated BC risk was found in any individual and combined effects of GSTM1 present/null, GSTT1 present/null, and GSTP1 IIe105Val polymorphisms. However, when we restricted studies only involving with high-quality, matching, HWE, and genotyping examination performed blindly or with quality control, significantly increased BC risk was only found in overall population for GSTM1 null genotype, among all populations, Caucasians, and postmenopausal women for the combined effects of GSTM1 and GSTT1 polymorphisms, and in overall analysis for the combined effects of GSTM1, GSTT1, and GSTP1 IIe105Val polymorphisms. Further, less-credible positive results were identified when we evaluated the credibility of positive results of the current and previous meta-analyses. CONCLUSIONS: This meta-analysis indicates that the individual and combined effects of GSTM1, GSTT1 and GSTP1 polymorphisms may be not associated with increased BC risk.


Asunto(s)
Neoplasias de la Mama/genética , Predisposición Genética a la Enfermedad , Gutatión-S-Transferasa pi/genética , Glutatión Transferasa/genética , Polimorfismo de Nucleótido Simple/genética , Femenino , Estudios de Asociación Genética , Heterogeneidad Genética , Humanos , Probabilidad , Sesgo de Publicación , Factores de Riesgo
12.
Emerg Infect Dis ; 26(6): 1251-1256, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32168464

RESUMEN

Since December 2019, when the first case of coronavirus disease (COVID-19) was identified in the city of Wuhan in the Hubei Province of China, the epidemic has generated tens of thousands of cases throughout China. As of February 28, 2020, the cumulative number of reported deaths in China was 2,858. We estimated the time-delay adjusted risk for death from COVID-19 in Wuhan, as well as for China excluding Wuhan, to assess the severity of the epidemic in the country. Our estimates of the risk for death in Wuhan reached values as high as 12% in the epicenter of the epidemic and ≈1% in other, more mildly affected areas. The elevated death risk estimates are probably associated with a breakdown of the healthcare system, indicating that enhanced public health interventions, including social distancing and movement restrictions, should be implemented to bring the COVID-19 epidemic under control.


Asunto(s)
Infecciones por Coronavirus/mortalidad , Neumonía Viral/mortalidad , Betacoronavirus , China/epidemiología , Humanos , Pandemias , Probabilidad , Medición de Riesgo , Análisis de Supervivencia , Tasa de Supervivencia
13.
Nat Methods ; 17(3): 343-351, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32123394

RESUMEN

Virtual realities are powerful tools to analyze and manipulate interactions between animals and their environment and to enable measurements of neuronal activity during behavior. In many species, however, optical access to the brain and/or the behavioral repertoire are limited. We developed a high-resolution virtual reality for head-restrained adult zebrafish, which exhibit cognitive behaviors not shown by larvae. We noninvasively measured activity throughout the dorsal telencephalon by multiphoton calcium imaging. Fish in the virtual reality showed regular swimming patterns and were attracted to animations of conspecifics. Manipulations of visuo-motor feedback revealed neurons that responded selectively to the mismatch between the expected and the actual visual consequences of motor output. Such error signals were prominent in multiple telencephalic areas, consistent with models of predictive processing. A virtual reality system for adult zebrafish therefore provides opportunities to analyze neuronal processing mechanisms underlying higher brain functions including decision making, associative learning, and social interactions.


Asunto(s)
Conducta Animal , Encéfalo/diagnóstico por imagen , Neuronas/fisiología , Interfaz Usuario-Computador , Realidad Virtual , Animales , Mapeo Encefálico , Cognición , Toma de Decisiones , Femenino , Masculino , Destreza Motora , Probabilidad , Conducta Social , Natación , Pez Cebra
14.
Behav Brain Sci ; 43: e2, 2020 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-32159476

RESUMEN

When constrained by limited resources, how do we choose axioms of rationality? The target article relies on Bayesian reasoning that encounter serious tractability problems. We propose another axiomatic foundation: quantum probability theory, which provides for less complex and more comprehensive descriptions. More generally, defining rationality in terms of axiomatic systems misses a key issue: rationality must be defined by humans facing vague information.


Asunto(s)
Cognición , Solución de Problemas , Teorema de Bayes , Humanos , Probabilidad , Incertidumbre
17.
PLoS Comput Biol ; 16(2): e1007688, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32084135

RESUMEN

Cell-to-cell variability generates subpopulations of drug-tolerant cells that diminish the efficacy of cancer drugs. Efficacious combination therapies are thus needed to block drug-tolerant cells via minimizing the impact of heterogeneity. Probabilistic models such as Bliss independence have been developed to evaluate drug interactions and their combination efficacy based on probabilities of specific actions mediated by drugs individually and in combination. In practice, however, these models are often applied to conventional dose-response curves in which a normalized parameter with a value between zero and one, generally referred to as fraction of cells affected (fa), is used to evaluate the efficacy of drugs and their combined interactions. We use basic probability theory, computer simulations, time-lapse live cell microscopy, and single-cell analysis to show that fa metrics may bias our assessment of drug efficacy and combination effectiveness. This bias may be corrected when dynamic probabilities of drug-induced phenotypic events, i.e. induction of cell death and inhibition of division, at a single-cell level are used as metrics to assess drug efficacy. Probabilistic phenotype metrics offer the following three benefits. First, in contrast to the commonly used fa metrics, they directly represent probabilities of drug action in a cell population. Therefore, they deconvolve differential degrees of drug effect on tumor cell killing versus inhibition of cell division, which may not be correlated for many drugs. Second, they increase the sensitivity of short-term drug response assays to cell-to-cell heterogeneities and the presence of drug-tolerant subpopulations. Third, their probabilistic nature allows them to be used directly in unbiased evaluation of synergistic efficacy in drug combinations using probabilistic models such as Bliss independence. Altogether, we envision that probabilistic analysis of single-cell phenotypes complements currently available assays via improving our understanding of heterogeneity in drug response, thereby facilitating the discovery of more efficacious combination therapies to block drug-tolerant cells.


Asunto(s)
Antineoplásicos/uso terapéutico , Interacciones Farmacológicas , Quimioterapia Combinada , Neoplasias/tratamiento farmacológico , Neoplasias/fisiopatología , Probabilidad , Línea Celular Tumoral , Terapia Combinada , Simulación por Computador , Humanos , Melanoma/tratamiento farmacológico , Melanoma/fisiopatología , Modelos Estadísticos , Fenotipo , Distribución de Poisson
18.
PLoS Comput Biol ; 16(2): e1007642, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32097416

RESUMEN

Genes differ in the frequency at which they are expressed and in the form of regulation used to control their activity. In particular, positive or negative regulation can lead to activation of a gene in response to an external signal. Previous works proposed that the form of regulation of a gene correlates with its frequency of usage: positive regulation when the gene is frequently expressed and negative regulation when infrequently expressed. Such network design means that, in the absence of their regulators, the genes are found in their least required activity state, hence regulatory intervention is often necessary. Due to the multitude of genes and regulators, spurious binding and unbinding events, called "crosstalk", could occur. To determine how the form of regulation affects the global crosstalk in the network, we used a mathematical model that includes multiple regulators and multiple target genes. We found that crosstalk depends non-monotonically on the availability of regulators. Our analysis showed that excess use of regulation entailed by the formerly suggested network design caused high crosstalk levels in a large part of the parameter space. We therefore considered the opposite 'idle' design, where the default unregulated state of genes is their frequently required activity state. We found, that 'idle' design minimized the use of regulation and thus minimized crosstalk. In addition, we estimated global crosstalk of S. cerevisiae using transcription factors binding data. We demonstrated that even partial network data could suffice to estimate its global crosstalk, suggesting its applicability to additional organisms. We found that S. cerevisiae estimated crosstalk is lower than that of a random network, suggesting that natural selection reduces crosstalk. In summary, our study highlights a new type of protein production cost which is typically overlooked: that of regulatory interference caused by the presence of excess regulators in the cell. It demonstrates the importance of whole-network descriptions, which could show effects missed by single-gene models.


Asunto(s)
Regulación Fúngica de la Expresión Génica , Redes Reguladoras de Genes , Saccharomyces cerevisiae/genética , Transducción de Señal , Algoritmos , Sitios de Unión , Biología Computacional , Simulación por Computador , Modelos Biológicos , Distribución Normal , Probabilidad , Unión Proteica , Factores de Transcripción/metabolismo
19.
PLoS Comput Biol ; 16(2): e1007634, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32106245

RESUMEN

Obsessive compulsive (OC) symptoms involve excessive information gathering (e.g., checking, reassurance-seeking), and uncertainty about possible, often catastrophic, future events. Here we propose that these phenomena are the result of excessive uncertainty regarding state transitions (transition uncertainty): a computational impairment in Bayesian inference leading to a reduced ability to use the past to predict the present and future, and to oversensitivity to feedback (i.e. prediction errors). Using a computational model of Bayesian learning under uncertainty in a reversal learning task, we investigate the relationship between OC symptoms and transition uncertainty. Individuals high and low in OC symptoms performed a task in which they had to detect shifts (i.e. transitions) in cue-outcome contingencies. Modeling subjects' choices was used to estimate each individual participant's transition uncertainty and associated responses to feedback. We examined both an optimal observer model and an approximate Bayesian model in which participants were assumed to attend (and learn about) only one of several cues on each trial. Results suggested the participants were more likely to distribute attention across cues, in accordance with the optimal observer model. As hypothesized, participants with higher OC symptoms exhibited increased transition uncertainty, as well as a pattern of behavior potentially indicative of a difficulty in relying on learned contingencies, with no evidence for perseverative behavior. Increased transition uncertainty compromised these individuals' ability to predict ensuing feedback, rendering them more surprised by expected outcomes. However, no evidence for excessive belief updating was found. These results highlight a potential computational basis for OC symptoms and obsessive compulsive disorder (OCD). The fact the OC symptoms predicted a decreased reliance on the past rather than perseveration challenges preconceptions of OCD as a disorder of inflexibility. Our results have implications for the understanding of the neurocognitive processes leading to excessive uncertainty and distrust of past experiences in OCD.


Asunto(s)
Conducta , Simulación por Computador , Trastorno Obsesivo Compulsivo/fisiopatología , Incertidumbre , Adulto , Atención , Teorema de Bayes , Biología Computacional , Femenino , Humanos , Conocimiento , Aprendizaje , Masculino , Modelos Psicológicos , Método de Montecarlo , Variaciones Dependientes del Observador , Probabilidad , Análisis de Regresión , Adulto Joven
20.
Ecotoxicol Environ Saf ; 192: 110286, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32036101

RESUMEN

Trihalomethanes (THMs) in drinking water are associated with many chemical parameters in water. However, the available evidence on the relationship between physical parameters of the water distribution system (WDS) and THMs is still scarce; therefore, this study aimed to compare the THMs concentration in the old and new WDS in Yazd, Iran. Moreover, we investigated the seasonal trend and health risk assessment of exposure to THMs through ingestion, dermal, and inhalation pathways. Mann-Whitney test was applied to compare THMs between old and new WDS as well as fall season and winter season. The order of THM concentrations was: chloroform > BDCM > DBCM > bromoform. The maximum levels of THMs in the fall and winter were 31 and 39 ppb, respectively, which were less than the WHO recommended limits for drinking water, i.e., <200 ppb. There was a significant difference between the concentration of BDCM in autumn and winter (P-value = 0.01). There was a marginally significant difference between THM concentration in the autumn and winter (P-value 0.09). The total concentration of THMs and chloroform in the old WDS were significantly higher than the new WDS. The mean values of lifetime cancer risks (LTCR) for oral, dermal, and inhalation exposure pathways to THMs were in the acceptable and low-risk levels. The inhalation exposure pathway had the highest LTCR from among the three mentioned exposure pathways. The hazard index was found to be < 1 through oral and dermal pathways. Moreover, the sensitivity analysis revealed that the ingestion rate for oral exposure, the exposure time for dermal and exposure duration for the inhalation exposure pathway had the highest impact on chronic daily intake (CDI). Our finding confirmed that THM concentration in tap water was associated with the lifespan of WDS and this finding could be useful for urban planners and decision-makers.


Asunto(s)
Agua Potable/química , Trihalometanos/análisis , Contaminantes Químicos del Agua/análisis , Dermis , Exposición Dietética , Exposición a Riesgos Ambientales , Humanos , Exposición por Inhalación , Irán/epidemiología , Neoplasias/epidemiología , Probabilidad , Medición de Riesgo , Estaciones del Año , Abastecimiento de Agua
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