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1.
Environ Geochem Health ; 46(9): 342, 2024 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-39073664

RESUMEN

Mining is responsible for the release of metallic pollutants and radioactive materials into the environment, which have the potential to disrupt ecosystems and pose significant risks to human health. Significant mining activity is concentrated in the municipality of Caetité (northeastern Brazil), where Latin America's only active uranium mine and significant iron ore deposits are located. Although previous studies have shown that the regional soil and water resources are highly contaminated by various toxic elements and that exposure to these elements is known to have adverse effects on human health, the health risks in this mining region have never been assessed. The aim of this unprecedented comprehensive investigation was to assess the health, radiological and ecological risks in this mining region, which is home to nearly 100,000 people. To achieve our goal, soil and water samples were collected in the vicinity of the mines and in the main settlements in the region. Fifteen metallic toxic elements were determined using Instrumental Neutron Activation Analysis and Inductively Coupled Plasma Optical Emission Spectrometry. The HERisk code, which follows the main methodological guidelines for risk assessment, was used to quantify human health, radiological and ecological indices. The average values of the total risk and cancer risk indices indicated that region falls into the moderate risk category (1.0 ≤ HItot < 4.0). However, 63% of the sites had high risk values, with Fe, Co and As being the metals contributing most to total and cancer risk, respectively. Near the mining areas, the potential ecological risk can be considered extreme (PERI ≥ 600). The values of the calculated radiological indices correspond to typical values ​​in natural uranium areas. However, in the communities near the mine, the dose values are slightly above the permissible limit (1 mSv y-1), so they must be continuously monitored, and risk mitigation measures must be taken.


Asunto(s)
Minería , Humanos , Brasil , Medición de Riesgo , Monitoreo del Ambiente , Contaminantes del Suelo/análisis , Contaminantes Químicos del Agua/análisis , Exposición a Riesgos Ambientales , Monitoreo de Radiación
2.
J Anim Sci ; 1022024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-39028536

RESUMEN

With global warming, there are growing challenges for raising taurine and composite beef cattle populations in tropical regions, including elevated temperatures, limited forage availability, parasite infestation, and infectious diseases. These environmental factors can trigger specific physiological responses in the developing fetus, which may have long-term implications on its performance. Therefore, the main objective of this study was to assess the influence of naturally induced thermal stress during the gestation period on the subsequent performance of tropical composite beef cattle progeny. Furthermore, we aimed to investigate the impact of genotype-by-gestational thermal environment interaction (G×Eg) on traits under selection pressure in the breeding population. A total of 157,414 animals from 58 farms located in various Brazilian states were recorded for birth weight (BW), preweaning weight gain (PWG), yearling weight (YW), hip height (HH), scrotal circumference (SC), and days to first calving (DFC). We first applied a linear regression model to the BW data, which revealed that the last 40 d of gestation were suitable for calculating the mean temperature humidity index (THIg). Subsequent regression analyses revealed that for every 10-unit increase in THIg, detrimental effects of approximately 1.13% to 16.34% are expected for all traits evaluated. Genetic parameters were estimated through a reaction norm model using THIg as the environmental descriptor. The posterior means of heritability estimates (SD) were 0.35 (0.07), 0.25 (0.03), 0.31 (0.03), 0.37 (0.01), 0.29 (0.07), and 0.20 (0.09) for the direct effect of BW, PWG, YW, HH, SC, and DFC, respectively. These estimates varied along the range of THIg values, suggesting a variable response to selection depending on the thermal environment during gestation. Genetic correlation estimates between more divergent THIg values were low or negative for YW, PWG, and DFC, indicating that the best-performing individuals at low THIg values may not perform as well at high THIg values and vice versa. Overall, thermal stress during gestation impacts the future performance of beef cattle offspring. Our results indicate the need for developing effective breeding strategies that take into account G×Eg effects and the re-ranking of breeding animals along the THIg scale, particularly for traits such as DFC that are highly sensitive to thermal stress.


With global warming posing increasing challenges in tropical regions, this study aimed to assess the impact of thermal stress during gestation on the performance of composite beef cattle offspring. Environmental factors such as high temperatures, humidity, limited forage availability, and parasite infestation can elicit physiological responses in the developing fetus, affecting its long-term performance and welfare. Using the temperature humidity index (THIg) of the late gestation as a measure of thermal environment, a reaction norm model was applied to analyze the birth weight, preweaning weight gain, yearling weight, hip height, scrotal circumference, and days to first calving (DFC). Results revealed that increasing THIg values were associated with a detrimental effect in these traits. Genotype-by-environment interaction was found to significantly influence trait variability, with DFC showing the strongest effect. Negative genetic correlations were observed between divergent THIg values, suggesting that individuals performing well in mild thermal environments may not excel in high thermal stress conditions. The heritability estimates varied along the THIg scale, indicating that selection response may vary depending on the thermal environment during gestation. These findings emphasize the need for breeding strategies that account for genotype-by-environment effects and consider the impact of thermal stress on cattle performance.


Asunto(s)
Genotipo , Animales , Bovinos/genética , Bovinos/fisiología , Femenino , Embarazo , Brasil , Masculino , Clima Tropical , Peso al Nacer , Cruzamiento , Aumento de Peso , Temperatura
3.
Heliyon ; 10(11): e32016, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38882303

RESUMEN

The set of singular values of a digraph with respect to a vertex-degree based topological index is the set of all singular values of its general adjacency matrix. The spectral norm is the largest singular value and the energy the sum of the singular values. In this paper we characterize the digraphs which have exactly one singular value different from zero and the digraphs for which all singular values are equal. As a consequence, we deduce sharp upper and lower bounds for the spectral norm and energy of digraphs. In addition to being a natural generalization, proving the results in the general setting of digraphs allows us to deduce new results on graph energy.

4.
Sensors (Basel) ; 24(12)2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38931751

RESUMEN

This work addresses the challenge of classifying multiclass visual EEG signals into 40 classes for brain-computer interface applications using deep learning architectures. The visual multiclass classification approach offers BCI applications a significant advantage since it allows the supervision of more than one BCI interaction, considering that each class label supervises a BCI task. However, because of the nonlinearity and nonstationarity of EEG signals, using multiclass classification based on EEG features remains a significant challenge for BCI systems. In the present work, mutual information-based discriminant channel selection and minimum-norm estimate algorithms were implemented to select discriminant channels and enhance the EEG data. Hence, deep EEGNet and convolutional recurrent neural networks were separately implemented to classify the EEG data for image visualization into 40 labels. Using the k-fold cross-validation approach, average classification accuracies of 94.8% and 89.8% were obtained by implementing the aforementioned network architectures. The satisfactory results obtained with this method offer a new implementation opportunity for multitask embedded BCI applications utilizing a reduced number of both channels (<50%) and network parameters (<110 K).


Asunto(s)
Algoritmos , Interfaces Cerebro-Computador , Aprendizaje Profundo , Electroencefalografía , Redes Neurales de la Computación , Electroencefalografía/métodos , Humanos , Procesamiento de Señales Asistido por Computador
5.
Front Nutr ; 11: 1353569, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38638294

RESUMEN

Introduction: The willingness to consume healthy foods has highlighted the growing importance of health, even more so when it comes to food choice, and predicting the willingness to consume foods of a healthy brand represents an action that leads to the practice of conscious eating habits, but what is behind this willingness? To answer this question and based on previous studies such as the theory of planned behavior and nutritional literacy, this study aimed to build a predictive model through an empirical study to examine the influence of nutritional literacy (NL) on attitude (ATT), subjective norm (SN) and perceived behavioral control (PBC), as well as to determine the influence of the three variables of the theory of planned behavior (TPB) on the willingness to consume healthy brand foods (WCHBF) in the Peruvian market. Methods: The research focused on the population that stated that they were consumers of the Unión brand (a brand whose value proposition is the sale of healthy foods), obtaining 482 consumers. The study was conducted under a quantitative, non-experimental, cross-sectional design approach. Results: The results support the existence of a positive and significant effect of NL on ATT, SN, and PBC, finding the exact behavior of SN and PBC in WCHBF; however, in the proposed model, it is observed that ATT has no impact on WCHBF. Conclusion: Applying strategies that lead to a change in consumer behavior towards healthy brands is a matter of time and will. In this context, the findings indicate that nutritional literacy plays an essential role in the willingness to consume healthy foods, which sheds more light on the design of educational interventions and awareness campaigns that independently inform about nutritional benefits and empower consumers, allowing them to make informed and healthy choices.

6.
BMC Public Health ; 24(1): 1101, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38649855

RESUMEN

BACKGROUND: The characteristics of the implementation process of interventions are essential for bridging the gap between research and practice. This scoping review aims to identify the implementation process of social network interventions (SNI) to address physical activity and sedentary behaviors in children and adolescents. METHODS: The scoping review was conducted adhering to the established guidelines. The search was carried out in the ERIC, EBSCO, EMBASE, SCOPUS, and Lilacs databases in April 2023. Social network intervention studies in children and adolescents were included, addressing physical activity or sedentary behaviors. Replicability (TIDieR), applicability (PRECIS-2), and generalizability (RE-AIM) were the explored components of the implementation process. Each component was quantitatively and separately analyzed. Then, a qualitative integration was carried out using a narrative method. RESULTS: Most SNI were theoretically framed on the self-determination theory, used social influence as a social mechanism, and used the individual typology of network intervention. Overall, SNI had strong replicability, tended to be pragmatic, and three RE-AIM domains (reach, adoption (staff), and implementation) showed an acceptable level of the generalizability of findings. CONCLUSIONS: The analyzed SNI for physical activity and sedentary behaviors in adolescents tended to be reported with high replicability and were conducted pragmatically, i.e., with very similar conditions to real settings. The RE-AIM domains of reach, adoption (staff), and implementation support the generalizability of SNI. Some domains of the principles of implementation strategies of SNI had acceptable external validity (actor, action targets, temporality, dose, and theoretical justification).


Asunto(s)
Ejercicio Físico , Conducta Sedentaria , Humanos , Adolescente , Ejercicio Físico/psicología , Niño , Promoción de la Salud/métodos , Red Social , Apoyo Social
7.
Children (Basel) ; 11(1)2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-38255383

RESUMEN

This study focuses on understanding the relationship between moral disengagement mechanisms in adolescents who engage in law-breaking activities and those who violate school norms. To do so, we administered the Mechanisms of Moral Disengagement Scale (MMDS), which evaluates moral justification, euphemistic labeling, advantageous comparison, deflection of responsibility, diffusion of responsibility, distortion of consequences, dehumanization, and attribution of blame, to 366 adolescents (60.1% males (n = 220) and 39.9% females (n = 146)). Our results confirmed the hypothesis that law-breaking adolescents presented a higher degree of moral disengagement than those adolescents who violate school norms. Additionally, we found that adolescents who violated school norms displayed significantly higher levels of dehumanization than the controls, and law-breaking adolescents obtained the highest score in this domain. Our findings allow us to suggest that the presence of the dehumanization mechanism in adolescents who violate school norms could be used as an early indicator of the emergence of antisocial behaviors, since this was the only component of moral disengagement that significantly differentiated this group from the controls in the study.

8.
Neural Netw ; 171: 343-352, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38113719

RESUMEN

Despite the growing availability of high-capacity computational platforms, implementation complexity still has been a great concern for the real-world deployment of neural networks. This concern is not exclusively due to the huge costs of state-of-the-art network architectures, but also due to the recent push towards edge intelligence and the use of neural networks in embedded applications. In this context, network compression techniques have been gaining interest due to their ability for reducing deployment costs while keeping inference accuracy at satisfactory levels. The present paper is dedicated to the development of a novel compression scheme for neural networks. To this end, a new form of ℓ0-norm-based regularization is firstly developed, which is capable of inducing strong sparseness in the network during training. Then, targeting the smaller weights of the trained network with pruning techniques, smaller yet highly effective networks can be obtained. The proposed compression scheme also involves the use of ℓ2-norm regularization to avoid overfitting as well as fine tuning to improve the performance of the pruned network. Experimental results are presented aiming to show the effectiveness of the proposed scheme as well as to make comparisons with competing approaches.


Asunto(s)
Compresión de Datos , Redes Neurales de la Computación , Fenómenos Físicos
9.
Av. psicol. latinoam ; 41(2): [1-18], may-ago. 2023.
Artículo en Inglés | LILACS | ID: biblio-1510455

RESUMEN

This research investigated psychological correlates with norm non-compliance during the National State of Emergency declared in Peru at the time of the COVID-19 pandemic. Specifically, it looks at the relationship between Social Dominance Orientation (SDO), perceptions of legitimacy, strength and efficacy of the normative system, and trust in the institutions. It also looks at individual justifications for norm non-compliance and the frequency of transgression. A correlational research design using questionnaires was developed with a sample of 126 participants. Results show that transgression of government-issued norms during the Peruvian National State of Emergency is linked to the ideological compo- nent of SDO and perceptions of a weak and illegitimate normative system. These results are consistent with previous studies on normative transgression in Latin American countries. Additionally, results suggest that the need for subsistence (i.e., generating resources to sustain the household) is fundamental to comprehensively understanding transgressive behavior in contexts of vulnerability such as a global pandemic. The discussion highlights how a precarious socio-political structure ­ one incapable of meeting the basic needs of large sectors of the population­ emerges as a central cause of normative transgression in times of crisis


Esta investigación indaga los correlatos psicológicos con el incumplimiento de normas durante el Estado de Emergencia Nacional declarado en Perú con ocasión de la pandemia del COVID-19. Específicamente, se exa- mina la relación entre la Orientación a la Dominancia Social (ODS), las percepciones de legitimidad, fortaleza y eficacia del sistema normativo y la confianza en las instituciones. También examina las justificaciones individuales del incumplimiento de las normas, así como la frecuencia de la transgresión. Se desarrolló un diseño de investigación correlacional mediante cuestionarios con una muestra de 126 participantes. Los resultados muestran que la transgresión de las normas emitidas por el Gobierno durante el Estado de Emergencia Nacional peruano, están vinculadas al componente ideológico del ODS y a la percepción de un sistema normativo débil e ilegítimo. Estos resultados son consistentes con estudios previos sobre transgresión normativa en países latinoamericanos. Adicionalmente, los resultados sugieren que la necesidad de subsistencia (es decir, la generación de recursos para el sostenimiento del hogar), es fundamental para comprender de manera integral el comportamiento transgresor en contextos de vulnerabilidad como una pandemia global. La discusión destaca cómo una estructura sociopolítica precaria ­incapaz de satisfacer las necesidades básicas de amplios sectores de la población­ emerge como causa central de la transgresión normativa en tiempos de crisis.


Esta pesquisa investiga as correlações psicológicas com o descumprimento de normas durante o Estado Nacional de Emergência declarado no Peru na época da pandemia da COVID-19. Especificamente, ela analisa a relação entre a orientação de dominância social (ODS), as percepções de legitimidade, força e eficácia do sistema normativo e a confiança nas instituições. Também analisa as justificativas individuais para a não conformidade com a norma, bem como a frequência da transgressão. Um projeto de pesquisa correlacional usando questionários foi desenvolvido com uma amostra de 126 participantes. Os resultados mostram que a transgressão das normas emitidas pelo governo durante o Estado de Emergência Nacional do Peru está ligada ao componente ideológico da ODS e às percepções de um sistema normativo fraco e ilegítimo. Esses resultados são consistentes com estudos anteriores sobre transgressão normativa em países latino-americanos. Além disso, os resultados sugerem que a necessidade de subsistência (ou seja, a geração de recursos para sustentar a família) é fundamental para compreender de forma abrangente o comportamento transgressivo em contextos de vulnerabilidade, como uma pandemia global. A discussão destaca como uma estrutura socio- política precária ­incapaz de atender às necessidades básicas de grandes setores da população­ surge como uma causa central da transgressão normativa em tempos de crise.


Asunto(s)
Humanos
10.
São Paulo med. j ; São Paulo med. j;141(2): 146-153, Mar.-Apr. 2023. tab
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1424665

RESUMEN

Abstract BACKGROUND Stigmatization, which emerges depending on the sexual behavior of young individuals, leads to negative health and social outcomes, such as shame, social marginalization, violence, and mental health morbidity. Objective: This study aimed to examine the correlation between the level of sexual and reproductive health stigma and gender perception in female university students. DESIGN AND SETTING: This descriptive cross-sectional study was conducted at the Faculty of Health Sciences of a university in Turkey. METHODS: The data of this study were collected from digital media between July and October 2020 from a study population of 385 students. The data were collected using the Personal Information Form, including the socio-demographic characteristics of students, the Sexual and Reproductive Health Stigmatization Scale in Young Women and the Perception of Gender Scale. Descriptive statistics, independent samples t-test, analysis of variance, and Pearson's correlation test were used to assess the data. RESULTS: It was determined that there was a negative correlation between the Sexual and Reproductive Health Stigmatization Scale in Young Women and the Perception of Gender Scale (r = -0.173, P = 0.001). CONCLUSION: It was determined that as the gender perception in the young women who participated in the study increased, the sexual and reproductive health stigmatization level decreased. The sexual and reproductive health stigmatization levels of the participants were at an above average level, and gender perception was at a medium level.

11.
Front Public Health ; 11: 1059238, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36875405

RESUMEN

Aspergillus fumigatus is a common environmental mold and a major cause of opportunistic infections in humans. It's distributed among many ecological niches across the globe. A major virulence factor of A. fumigatus is its ability to grow at high temperature. However, at present, little is known about variations among strains in their growth at different temperatures and how their geographic origins may impact such variations. In this study, we analyzed 89 strains from 12 countries (Cameroon, Canada, China, Costa Rica, France, India, Iceland, Ireland, New Zealand, Peru, Saudi Arabia, and USA) representing diverse geographic locations and temperature environments. Each strain was grown at four temperatures and genotyped at nine microsatellite loci. Our analyses revealed a range of growth profiles, with significant variations among strains within individual geographic populations in their growths across the temperatures. No statistically significant association was observed between strain genotypes and their thermal growth profiles. Similarly geographic separation contributed little to differences in thermal adaptations among strains and populations. The combined analyses among genotypes and growth rates at different temperatures in the global sample suggest that most natural populations of A. fumigatus are capable of rapid adaptation to temperature changes. We discuss the implications of our results to the evolution and epidemiology of A. fumigatus under increasing climate change.


Asunto(s)
Aspergillus fumigatus , Cambio Climático , Humanos , Canadá , China , Costa Rica
12.
J Environ Radioact ; 261: 107139, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36842336

RESUMEN

The oil and gas industries are the largest producers of NORM wastes that are continuously generated during production and extraction activities. In addition, an increasing trend is observed in waste production worldwide due to the decommissioning of oil platforms. The problem is that most of these wastes are in activity concentration levels above the exemption and the clearance limits and are being accumulated in storage sites because no repositories exist in Brazil for NORM wastes generated by oil industries. There are regulations for radioactive wastes and for the licensing of repositories for managing wastes with low and intermediate levels of radiation but the current regulations apply only to packaged wastes. Therefore an initial radiological assessment was carried out with the RESRAD-OFFSITE code to show that bulk NORM wastes (not packaged wastes) could be disposed of in repositories near the surface without causing additional risk to the public above the criteria used. The results can also support decision-making by the Regulatory Authority to change the current regulations and allow for the disposal of wastes in bulk form.


Asunto(s)
Monitoreo de Radiación , Residuos Radiactivos , Eliminación de Residuos , Brasil , Residuos Radiactivos/análisis , Industrias , Eliminación de Residuos/métodos
13.
Genes Genomics ; 45(2): 135-143, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35689753

RESUMEN

BACKGROUND: Genotype by environment interactions (G × E) can play an important role in cattle populations and should be included in breeding programs in order to select the best animals for different environments. OBJECTIVE: The aim of this study was to investigate the G × E for milk production of Gyr cattle in Brazil and Colombia by applying a reaction norm model used genomics information, and to identify genomic regions associated with milk production in the two countries. METHODS: The Brazilian and Colombian database included 464 animals (273 cows and 33 sires from Brazil and 158 cows from Colombia) and 27,505 SNPs. A two-trait animal model was used for milk yield adjusted to 305 days in Brazil and Colombia as a function of country of origin, which included genomic information obtained with a single-step genomic reaction norm model. The GIBBS3F90 and POSTGSf90 programs were used. RESULTS: The results obtained indicate G × E based on the reranking of bulls between Brazil and Colombia, demonstrating environmental differences between the two countries. The findings highlight the importance of considering the environment when choosing breeding animals in order to ensure the adequate performance of their progeny. Within this context, the reranking of bulls and the different SNPs associated with milk production in the two countries suggest that G × E is an important effect that should be included in the genetic evaluation of Dairy Gyr cattle in Brazil and Colombia. CONCLUSION: The Gyr breeding program can be optimized by choosing a selection environment that will allow maximum genetic progress in milk production in different environments within and between countries.


Asunto(s)
Interacción Gen-Ambiente , Leche , Femenino , Bovinos/genética , Animales , Masculino , Lactancia/genética , Brasil , Colombia , Genotipo
14.
Animals (Basel) ; 12(19)2022 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-36230355

RESUMEN

The assessment of the presence of genotype by environment interaction (GxE) in beef cattle is very important in tropical countries with diverse climatic conditions and production systems. The present study aimed to assess the presence of GxE by using different reaction norm models for eleven traits related to growth, reproduction, and visual score in Nellore cattle. We studied five reaction norm models (RNM), fitting a linear model considering homoscedastic residual variance (RNM_homo), and four models considering heteroskedasticity, being linear (RNM_hete), quadratic (RNM_quad), linear spline (RNM_l-l), and quadratic spline (RNM_q-q). There was the presence of GxE for age at first calving (AFC), scrotal circumference (SC), weaning to yearling weight gain (WYG), and yearling weight (YW). The best models were RNM_l-l for YW and RNM_q-q for AFC, SC, and WYG. The heritability estimates for RNM_l-l ranged from 0.07 to 0.20, 0.42 to 0.61, 0.24 to 0.42, and 0.47 to 0.63 for AFC, SC, WYG, and YW, respectively. The heteroskedasticity in reaction norm models improves the assessment of the presence of GxE for YW, WYG, AFC, and SC. Additionally, the trajectories of reaction norms for these traits seem to be affected by a non-linear component, and selecting robust animals for these traits is an alternative to increase production and reduce environmental sensitivity.

15.
Front Psychol ; 13: 908631, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35899003

RESUMEN

Recycling is socially responsible behavior. Moreover, it is also a complex behavior. It benefits society in the long term but involves a personal cost and does not benefit the individual directly. In the specific context of small island, we conducted a two-step research action to promote recycling among households located in the north of Martinique, a west indies French island. Based on the psychosocial engineering model, the first step was to identify the determinants of recycling in this specific island context. In a psycho-environmental diagnostic, we included variables already identified to predict waste sorting, such as the TPB variables, as well as other context-specific variables, such as group identification, environmental identity, place identity, sense of community, perceived efficacy of one's action, as predictors of the intention to recycle. Based on psychological distance and its temporal dimension, we also distinguished between the intention to recycle today (proximal intention) and the intention to recycle in 1 month (distal intention). The results show that the predictors of recycling differ according to the temporal distance. The proximal intention was predicted by personal variables whereas distal intention was predicted by social variables. The second step was to design and to implement an evidence-based intervention to increase the quality of recycling. At Time 1, the garbage cans of 193 households were collected and characterized. At Time 2, the households were visited at home by an officer, who used one of the four communication scripts built on the basis of the results of the psycho-environmental diagnostic. At Time 3, the garbage cans were collected and characterized again. We observe an improvement in sorting in the condition where the TBP dimensions are activated: attitude, social norm, and controllability. Our results highlight the importance of taking into account the temporality of change, especially when the behavior to be changed is complex. They also show an interest in relying on a psycho-environmental diagnosis, taking into account the context of insertion of the target behavior.

16.
Magn Reson Med ; 88(2): 962-972, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35435267

RESUMEN

PURPOSE: Susceptibility maps are usually derived from local magnetic field estimations by minimizing a functional composed of a data consistency term and a regularization term. The data-consistency term measures the difference between the desired solution and the measured data using typically the L2-norm. It has been proposed to replace this L2-norm with the L1-norm, due to its robustness to outliers and reduction of streaking artifacts arising from highly noisy or strongly perturbed regions. However, in regions with high SNR, the L1-norm yields a suboptimal denoising performance. In this work, we present a hybrid data fidelity approach that uses the L1-norm and subsequently the L2-norm to exploit the strengths of both norms. METHODS: We developed a hybrid data fidelity term approach for QSM (HD-QSM) based on linear susceptibility inversion methods, with total variation regularization. Each functional is solved with ADMM. The HD-QSM approach is a two-stage method that first finds a fast solution of the L1-norm functional and then uses this solution to initialize the L2-norm functional. In both norms we included spatially variable weights that improve the quality of the reconstructions. RESULTS: The HD-QSM approach produced good quantitative reconstructions in terms of structural definition, noise reduction, and avoiding streaking artifacts comparable with nonlinear methods, but with higher computational efficiency. Reconstructions performed with this method achieved first place at the lowest RMS error category in stage 1 of the 2019 QSM Reconstruction Challenge. CONCLUSIONS: The proposed method allows robust and accurate QSM reconstructions, obtaining superior performance to state-of-the-art methods.


Asunto(s)
Mapeo Encefálico , Procesamiento de Imagen Asistido por Computador , Algoritmos , Encéfalo/diagnóstico por imagen , Mapeo Encefálico/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos
17.
Eng. sanit. ambient ; Eng. sanit. ambient;27(1): 103-111, jan.-fev. 2022. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1364820

RESUMEN

ABSTRACT Oil and gas, mining, among others, are examples of facilities where naturally occurring radioactive materials can be found. This study aims to evaluate the presence of natural radioactive series, especially those of 238U and 232Th, in the water treatment plants of Poços de Caldas City, Minas Gerais. The presence of these series was investigated in samples of raw water, treated water, sludge from decanters, and scale from Parshall gutters. The sludge, input, and scale samples were submitted to the gamma spectrometry technique to determine the 226Ra, 228Ra, and 210Pb radionuclides. For U and Th, ultraviolet visible spectrophotometry was performed, and for the alpha and beta total values, radiochemical separation and subsequent alpha and beta total counts were performed. The results indicate that water samples are within the Ministry of Health Ordinance n° 5 (2017). Due to the different concentrations of radionuclide activity in the sludge, it was not possible to affirm the same order of magnitude with the sediment from the catchments. However, the values are in accordance with those established by the European Union Council for Naturally-Occurring Radioactive Materials. In the scale, the contents of 1192, 1704, and 301 Bq kg−1 were identified for 226Ra, 228Ra, and 210Pb, respectively. In the inputs of aluminum sulfate and calcium hydroxide, no relevant activities were identified. The results obtained in the study can serve as an indicative regarding the need for a more detailed evaluation of the radiological issue in question concerning public water supplies.


RESUMO Petróleo e gás, mineração, estações de tratamento de água, entre outros, são exemplos de instalações que podem apresentar Materiais Radioativos de Ocorrência Natural. Neste estudo, objetivou-se avaliar a presença de séries radioativas naturais, especialmente as de 238U e 232Th nas estações de tratamento de água da cidade de Poços de Caldas/MG. Foram investigadas as presenças dessas séries em amostras de água bruta, de água tratada, no lodo dos decantadores e nas incrustações das calhas Parshall, além dos principais insumos utilizados. As amostras de lodo, insumos e incrustações foram submetidas à técnica de espectrometria gama para a determinação dos radionuclídeos 226Ra, 228Ra e 210Pb. Para U e Th, realizou-se espectrofotometria ultravioleta-visível, e para os valores de Alfa e Beta totais foram realizadas separação radioquímica e posterior contagem Alfa e Beta total. Os resultados indicaram que as amostras de águas estão em conformidade com a Portaria de Consolidação n° 5 de 2017 do Ministério da Saúde. Dadas as diferentes concentrações de atividade dos radionuclídeos no lodo, não foi possível afirmar a mesma ordem de magnitude com o sedimento das captações. Entretanto, os valores estão consonantes com o estabelecido pelo conselho da União Europeia para Materiais Radioativos de Ocorrência Natural. Nas incrustações foram identificados teores de 1.192 Bq.kg-1, 1.704 Bq.kg-1 e 301 Bq.kg-1 para 226Ra, 228Ra e 210Pb, respetivamente. Já para os insumos Sulfato de Alumínio (Al4(SO4)3) e Hidróxido de Cálcio Ca(OH)2 não foram identificadas atividades relevantes. Os resultados obtidos no estudo podem servir como indicativos da necessidade de uma avaliação mais detalhada sobre a questão radiológica em foco, em relação ao abastecimento público de águas.

18.
Br J Educ Psychol ; 92(3): 925-954, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35032033

RESUMEN

INTRODUCTION: Previous research has shown that peer victimization can be highly responsive to variables at the classroom level. Aggressive and prosocial norms may promote or reduce its status in classrooms. However, yet there is an apparent lack of success to explain which types of norms are more influential. This study examined the role of aggressive and prosocial descriptive and status norms in the peer victimization-status link. It also explores how the network density increases adherence to the prevailing norm in the classroom and its effect on the status of the victims. METHOD: Data on peer acceptance and rejection, victimization, prosocial behaviour, and aggression were collected with sociometric methods in a sample of 6,600 students (M = 13.1 years, SD = 0.6; 49.2% girls), from 269 classrooms in 81 secondary schools in Spain. Group norms for aggression and for prosocial behaviour were assessed in three ways, the behaviour of all peers (class-norm), the behaviour of most-liked peers (likeability-norm), and the behaviour of most salient peers (visibility-norm). RESULTS: Multilevel regression analyses revealed that the negative impact of victimization on peer likeability was moderated by the classroom's norm for prosocial behaviour, by the status norm of most visible peers' norm for prosocial behaviour and for aggression, and by the group's network density. The behavioural status norms of most likeable peers had no significant effect. CONCLUSION: These results underscore the overall importance of group context as a moderating factor of the relation between victimization and peer status in adolescents, and add to the growing body of knowledge driven by the socio-ecological approach to the study of peer relations in developmental psychology. As implications for education, these results affect the importance of considering socio-emotional variables in the formation of class groups in order to reduce victimization.


Asunto(s)
Acoso Escolar , Víctimas de Crimen , Adolescente , Agresión/psicología , Altruismo , Acoso Escolar/psicología , Víctimas de Crimen/psicología , Femenino , Humanos , Masculino , Grupo Paritario
19.
Appl Psychol Health Well Being ; 14(1): 81-100, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34254447

RESUMEN

We here studied some potential factors underlying variation in compliance with preventive behaviors against COVID-19 by studying mask wearing during outdoor recreational activities in a midsize city of Argentina in 2020. The originality of present research relies on the complementation of observational (N = 15,507) and survey (N = 578) data and in assessing the determinants of and disposition to the same preventive behavior across activities. In Study 1, we did 8 weeks of unobtrusive systematic observation of mask wearing in outdoor recreational sites as a function of activity (walking, running, and cycling). In Study 2, we ran an online survey (concomitant with the last weeks of the observational study) to measure self-reported mask use and relevant beliefs, including self- and other-regarding motives. Behavioral observations showed that mask wearing declined over time for the three activities as predicted from a social dilemma perspective; nonetheless, compliance significantly differed across activities. Self-reported mask use was predicted by the perceived risk of contagion for the self and for others, perceived comfort costs of wearing masks, and social norms, but not by perceived illness severity or mask effectiveness. We discuss some implications and limitations of present findings for the development of preventive strategies to reduce COVID-19 transmission.


Asunto(s)
COVID-19 , Humanos , Máscaras , Pandemias , SARS-CoV-2 , Encuestas y Cuestionarios
20.
Magn Reson Med ; 87(1): 457-473, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34350634

RESUMEN

PURPOSE: The presence of dipole-inconsistent data due to substantial noise or artifacts causes streaking artifacts in quantitative susceptibility mapping (QSM) reconstructions. Often used Bayesian approaches rely on regularizers, which in turn yield reduced sharpness. To overcome this problem, we present a novel L1-norm data fidelity approach that is robust with respect to outliers, and therefore prevents streaking artifacts. METHODS: QSM functionals are solved with linear and nonlinear L1-norm data fidelity terms using functional augmentation, and are compared with equivalent L2-norm methods. Algorithms were tested on synthetic data, with phase inconsistencies added to mimic lesions, QSM Challenge 2.0 data, and in vivo brain images with hemorrhages. RESULTS: The nonlinear L1-norm-based approach achieved the best overall error metric scores and better streaking artifact suppression. Notably, L1-norm methods could reconstruct QSM images without using a brain mask, with similar regularization weights for different data fidelity weighting or masking setups. CONCLUSION: The proposed L1-approach provides a robust method to prevent streaking artifacts generated by dipole-inconsistent data, renders brain mask calculation unessential, and opens novel challenging clinical applications such asassessing brain hemorrhages and cortical layers.


Asunto(s)
Artefactos , Mapeo Encefálico , Algoritmos , Teorema de Bayes , Encéfalo/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética
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