Improved data assimilation for algal bloom dynamics simulation in the Three Gorges Reservoir using particle filter.

Algal blooms have been increasingly prevalent in recent years, especially in lakes and reservoirs; their accurate prediction is essential for preserving water quality. In this study, the observed chlorophyll a (chl-a) levels were assimilated into the Environmental Fluid Dynamics Code (EFDC) of algal bloom dynamics by using a particle filter (PF), and the state variables of water quality and model parameters were simultaneously updated to achieve enhanced algal bloom predictive performance. The developed data assimilation system for algal blooms was applied to Xiangxi Bay (XXB) in the Three Gorges Reservoir (TGR). The results show that the ensemble mean accuracy and reliability of the confidence intervals of the predicted state variables, including chl-a and indirectly updated phosphate (PO4), ammonium (NH4), and nitrate (NO3) levels, were considerably improved after PF assimilation. Thus, PF assimilation is an effective tool for the dynamic correction of parameters to represent their inherent variations. Increased assimilation frequency can effectively suppress the accumulation of model errors; therefore, the use of high-frequency water quality data for assimilation is recommended to ensure more accurate and reliable algal bloom prediction.

Physiological monitoring of intensity training in female wrestlers / Monitoramento fisiológico no treino físico de intensidade em lutadoras femininas / Monitoreo fisiológico en el entrenamiento físico de intensidad en las luchadoras femeninas

ABSTRACT Introduction Currently, female wrestling has become one of the potential advantages in the Olympic Games, which has also allowed the sport to receive more attention. Physiological monitoring in intense physical training in female wrestlers is still little explored despite its importance in training conduction. Objective Explore special intensity physical training effects on female wrestlers through physiological monitoring. Methods Literature search, expert interview, and an experimental method conducted a situation analysis on 2-month training for 8 female wrestling team athletes, specific contents also included: analysis of female wrestlers' body composition, changes in serum testosterone levels, and variations in cortisol levels. Results During the two-month training period, the various athletes' physiological indicators underwent noticeable changes, remaining at the top of the normal range. Most of the athletes could adapt to the training load and intensity in this phase. Serum testosterone, cortisol, and hemoglobin levels in early athletes increased significantly. However, as training progresses, all indicators decrease, showing that the adaptability of the athlete's body is consolidated. The hemoglobin content increased in most of the athletes, showing that the athlete's own intensity of physical training was high. Conclusion The above physiological indicators can reflect the physical function of the athletes, providing a theoretical basis for coaches to develop evidence-based training plans. Evidence Level II; Therapeutic Studies - Investigating the result.

RESUMO Introdução Atualmente, a luta livre feminina tornou-se uma das vantagens potenciais dos Jogos Olímpicos, o que também permitiu que o esporte recebesse maior atenção. O monitoramento fisiológico no treino físico de intensidade em lutadoras femininas ainda é pouco explorado apesar da sua importância na condução do treinamento. Objetivo Explora os efeitos do treinamento físico especial para a intensidade em lutadoras femininas através de monitoramento fisiológico. Métodos Pesquisa literária, entrevista com especialistas e o método experimental levaram a uma análise da situação sobre o treinamento de 2 meses para 8 atletas da equipe de luta livre feminina, os conteúdos específicos incluíram: análise da composição corporal das lutadoras, alterações nos níveis séricos de testosterona e variações nos níveis de cortisol. Resultados Durante o período de dois meses de treinamento, os vários indicadores fisiológicos das atletas sofreram alterações perceptíveis, permanecendo no limite alto da faixa normal. A maioria das atletas pode se adaptar à carga e intensidade do treinamento nesta fase. Os níveis de testosterona sérica, cortisol e hemoglobina nas atletas precoces aumentaram significativamente. Porém, à medida que o treinamento progride, todos os indicadores diminuem, mostrando que a adaptabilidade do corpo da atleta é consolidada. O conteúdo de hemoglobina aumentou na maioria das atletas, mostrando que o treino físico de intensidade da própria atleta foi elevado. Conclusão Os indicadores fisiológicos acima podem refletir a função física das atletas, fornecendo uma base teórica para que os treinadores possam desenvolver planos de treinamento baseados em evidências. Nível de evidência II; Estudos Terapêuticos - Investigação de Resultados.

RESUMEN Introducción En la actualidad, la lucha femenina se ha convertido en una de las ventajas potenciales de los Juegos Olímpicos, lo que también ha permitido que este deporte reciba más atención. El seguimiento fisiológico en el entrenamiento físico de intensidad en las luchadoras es todavía poco explorado a pesar de su importancia en la conducción del entrenamiento. Objetivo Explorar los efectos del entrenamiento físico especial para la intensidad en las luchadoras a través de la monitorización fisiológica. Métodos La investigación bibliográfica, la entrevista a expertos y el método experimental condujeron a un análisis de situación sobre 2 meses de entrenamiento de 8 atletas del equipo femenino de lucha, los contenidos específicos incluían: análisis de la composición corporal de las luchadoras, cambios en los niveles séricos de testosterona y variaciones en los niveles de cortisol. Resultados Durante los dos meses de entrenamiento, los diversos indicadores fisiológicos de los atletas sufrieron cambios notables, manteniéndose en el extremo superior del rango normal. La mayoría de los atletas pudieron adaptarse a la carga e intensidad del entrenamiento en esta fase. Los niveles de testosterona, cortisol y hemoglobina en suero de los primeros atletas aumentaron significativamente. Sin embargo, a medida que el entrenamiento avanza, todos los indicadores disminuyen, lo que demuestra que la adaptabilidad del cuerpo del atleta se consolida. El contenido de hemoglobina aumentó en la mayoría de los atletas, lo que demuestra que el entrenamiento físico de intensidad propia fue alto. Conclusión Los indicadores fisiológicos anteriores pueden reflejar la función física de los atletas, proporcionando una base teórica para que los entrenadores desarrollen planes de entrenamiento basados en pruebas. Nivel de evidencia II; Estudios terapéuticos - Investigación de resultados.

Runners sports injuries and rehabilitation / Lesões esportivas e reabilitação em praticantes de corrida / Lesiones deportivas y rehabilitación en corredores

ABSTRACT Introduction Independent athletes and sports enthusiasts are subject to injuries due to several factors, such as neglect of physical preparation, lack of knowledge of the evolutionary progression of load intensity, and deficient stretching. Running is a popular sport in China, and the knowledge of the injuries caused by this group of fans may guide awareness behaviors to prevent accidents in sports practice. Objective Evaluate the injuries and rehabilitation of runners. Methods A total of 265 ordinary chinese runners (166 men) were selected as research subjects. Information on running sports injury characteristics, subjective perception of the causes of runners' injuries, prevention and rehabilitation methods in runners' injuries were evaluated. Results The knee joint has the highest proportion of injuries (26.73%), followed by foot injuries (13.11%) and ankle injuries (10.65%). Pain after exercise was reported by 38.12% of the runners, while 21.89% felt pain during the race. Conclusion Warm-up exercises are recommended before sports practice. Protective equipment can reduce the probability of injuries. Such equipment is considered a method of treatment and prevention with greater satisfaction and better adherence among runners. Evidence Level II; Therapeutic Studies - Investigating the result.

RESUMO Introdução Atletas independentes e entusiastas esportivos estão sujeitos a lesões por vários fatores como negligência do preparo físico, desconhecimento na progressão evolutiva de intensidade de carga e alongamentos deficitários. A corrida é um esporte popular na China e o conhecimento das lesões ocasionadas nesse grupo de adeptos poderá guiar condutas de conscientização para a prevenção de acidentes na prática esportiva. Objetivo Avaliar as lesões e a reabilitação nos praticantes de corrida. Métodos Um total de 265 corredores comuns chineses (166 homens) foram selecionados como objetos de pesquisa. Foram avaliadas as informações sobre as características das lesões esportivas de corrida, a percepção subjetiva das causas das lesões dos corredores, métodos de prevenção e reabilitação nas lesões dos corredores. Resultados A articulação do joelho apresenta a maior proporção nas lesões (26,73%), seguida por lesões nos pés (13,11%) e tornozelos (10,65%). Dores após o exercício foram relatadas por 38,12% dos corredores enquanto 21,89% dos corredores sentem dor durante a corrida. Conclusão Recomenda-se a realização de exercícios de aquecimento antes da prática esportiva. Os equipamentos de proteção podem reduzir a probabilidade das lesões. A utilização desses equipamentos é considerada um método de tratamento e prevenção com maior satisfação e melhor adesão entre os corredores. Nível de evidência II; Estudos Terapêuticos - Investigação de Resultados.

RESUMEN Introducción Los atletas independientes y los entusiastas del deporte están sujetos a lesiones por varios factores como la negligencia en la preparación física, la falta de conocimiento en la progresión de la intensidad de la carga y los estiramientos deficientes. La corrida es un deporte muy popular en China y el conocimiento de las lesiones causadas en este grupo de aficionados puede orientar las conductas de concienciación para la prevención de accidentes en la práctica deportiva. Objetivo Evaluar las lesiones y la rehabilitación en los practicantes de corrida. Métodos Un total de 265 corredores chinos ordinarios (166 hombres) fueron seleccionados como sujetos de la investigación. Se evaluó la información sobre las características de las lesiones deportivas de los corredores, la percepción subjetiva de las causas de las lesiones de los corredores y los métodos de prevención y rehabilitación en las lesiones de los corredores. Resultados La articulación de la rodilla es la que presenta la mayor proporción de lesiones (26,73%), seguida por las del pie (13,11%) y las del tobillo (10,65%). El 38,12% de los corredores declararon dolor después del ejercicio, mientras que el 21,89% de los corredores sintieron dolor durante la carrera. Conclusión Se recomienda realizar ejercicios de calentamiento antes de la práctica deportiva. El equipo de protección puede reducir la probabilidad de lesiones. El uso de estos equipos se considera un método de tratamiento y prevención con mayor satisfacción y mejor adherencia entre los corredores. Nivel de evidencia II; Estudios terapéuticos - Investigación de resultados.

Evaluation of high levels of sports activity and the beneficial effect on postprandial blood glucose profiles / Avaliação dos altos níveis de atividade esportiva e o efeito benéfico nos perfis de glicemia pós-prandial / Evaluación de los niveles elevados de actividad deportiva y el efecto positivo en los perfiles de glucemia postprandial

ABSTRACT Introduction: Hyperglycemia is the principal characteristic component of type 2 diabetes. High blood glucose concentrations for long periods can be countered with postprandial exercise by increasing glucose retention involuntary muscles. However, no research is present on the relationship between exercise time and glucose levels. Objective: This study evaluates the relationship between sports activity and postprandial glycemia levels. Methodology: Forty-five individuals were included in the study, 10 males and 35 females with an age of 27.11±2.8 years; a body fat percentage of 25.02% ±5.04%; and a body mass index of 22.74±4.55 kg/m2. Participants were included via WhatsApp for daily information on postprandial activity levels. WhatsApp messages were forwarded to a total of 2,500 people at different colleges and universities. Out of the total 60 active people (2.40%) who responded, 45 individuals participated in the study. They were divided into three categories based on self-reported postprandial activity: not very active (15), quite active (15), highly active (15). All active individuals completed an oral glucose intake test with blood samples obtained for evaluation at 15, 30, 45, 60, 90, and 120 minutes post-rest. On a gender basis, the groups could not be associated (P =.057). Results: All active groups showed a remarkable effect on blood glucose level at one hour (P =.031). A mean increase in blood glucose level in the first hour of 1.50 mmol/L was observed for every extra 1.0 mmol/L of standard glycemic amount, on average, women had a higher blood glucose amount of 1.35 mmol/L than men. Conclusion: It can be concluded that a high amount of postprandial activity generates a good outcome on glycemic parameters. Evidence Level II; Therapeutic Studies - Investigating the results.

RESUMO Introdução: A hiperglicemia é o principal componente característico na diabetes tipo 2. Altas concentrações de glicose por longos períodos podem ser combatidas com o exercício pós-prandial, aumentando a retenção de glicose nos músculos voluntários. Porém, ainda não há estudos sobre a relação entre o tempo de exercício e os níveis de glicose. Objetivo: Este estudo tem como objetivo avaliar a relação entre a atividade esportiva e os dados temporais de glicemia pós-prandial. Metodologia: Foram incluídos 45 indivíduos no estudo, sendo 10 do sexo masculino e 35 do sexo feminino com idade de 27,11± 2,8 anos; percentual de gordura corporal de 25,02% ±5,04%; e índice de massa corporal de 22,74±4,55 kg/m2. Os participantes foram incluídos via WhatsApp para obter informações diárias sobre os níveis de atividade pós-prandial. As mensagens de WhatsApp foram encaminhadas para um total de 2.500 pessoas em diferentes faculdades e universidades. No total de 60 pessoas ativas (2,40%) que responderam, participaram do estudo 45 indivíduos. Eles foram divididos em três categorias com base na atividade pós-prandial autorrelatada: pouco ativos (15), bastante ativos (15), altamente ativos (15). Todos os indivíduos ativos finalizaram um teste de ingestão de glicose oral com amostras de sangue obtidas para avaliação em 15, 30, 45, 60, 90 e 120 minutos pós-repouso. Na base de gênero, os grupos não puderam ser associados (P =.057). Resultados: Todos os grupos ativos revelaram um efeito notável do nível de glicose no sangue em uma hora (P =.031). Foi observado um aumento médio no nível de glicemia na primeira hora de 1,50 mmol/L para cada 1,0 mmol/L extra de quantidade glicêmica padrão, em média, as mulheres tiveram uma quantidade glicêmica no sangue de 1,35 mmol/L superior aos homens. Conclusão: Conclui-se que a alta quantidade de atividade pós-prandial gera um bom desfecho nos parâmetros glicêmicos. Nível de evidência II; Estudos Terapêuticos - Investigação de Resultados.

RESUMEN Introducción: La hiperglucemia es el principal componente característico de la diabetes de tipo 2. Las concentraciones elevadas de glucosa durante largos periodos pueden combatirse con el ejercicio postprandial, aumentando la retención de glucosa en los músculos voluntarios. Sin embargo, todavía no hay estudios sobre la relación entre el tiempo de ejercicio y los niveles de glucosa. Objetivo: Este estudio pretende evaluar la relación entre la actividad deportiva y los datos de glicemia postprandial. Metodología: Se incluyeron 45 individuos en el estudio, siendo 10 hombres y 35 mujeres con una edad de 27,11±2,8 años; un porcentaje de grasa corporal de 25,02% ±5,04%; y un índice de masa corporal de 22,74±4,55 kg/m2. Se inscribió a los participantes a través de WhatsApp para obtener información diaria sobre los niveles de actividad postprandial. Se enviaron mensajes de WhatsApp a un total de 2.500 personas de diferentes colegios y universidades. Del total de 60 personas activas (2,40%) que respondieron, 45 individuos participaron en el estudio. Fueron divididos en tres categorías basadas en la actividad postprandial auto declarada: poco activos (15), bastante activos (15), muy activos (15). Todos los individuos activos completaron una prueba de ingesta de glucosa oral con muestras de sangre obtenidas para su evaluación a los 15, 30, 45, 60, 90 y 120 minutos después del reposo. En lo que respecta al género, los grupos no pudieron asociarse (P = 0,057). Resultados: Todos los grupos activos revelaron un efecto notable del nivel de glucosa en la sangre a una hora (P = 0,031). Se observó un aumento medio del nivel de glucosa en la sangre en la primera hora de 1,50 mmol/L por cada 1,0 mmol/L adicional de la cantidad de glucemia estándar; por término medio, las mujeres tuvieron una cantidad de glucosa en la sangre más alta de 1,35 mmol/L que los hombres. Conclusión: Se concluye que la elevada actividad postprandial genera un buen resultado en los parámetros glucémicos. Nivel de evidencia II; Estudios terapéuticos - Investigación de resultados.

Refinement of saliva mi-rna biomarkers for sport-related concussion / Refinamento de biomarcadores de saliva mi-rna para concussão relacionada ao esporte / Refinamiento de los biomarcadores de mi-arn de la saliva para la conmoción encefálica relacionada con el deporte

ABSTRACT Introduction: The changes in brain structure caused by a sports-related concussion may initially be indistinguishable, however, the irreversible deleterious effects are noted in the long term. An early diagnosis may provide the patient with a better recovery chance and increased survival. For this purpose, this paper studies the feasibility of a diagnosis for concussion by microRNA (mi-RNA) biomarkers contained in the saliva of athletes. Objective: Verify whether salivary miRNAs could be considered good biomarkers for sports concussion. Methodology: Salivary mi-RNA levels were determined from 120 saliva samples of 120 players. There were 43 with a diagnosis of concussion and 77 without a diagnosis of concussion. Samples from players with a concussion were collected 30 minutes prior to activity, samples from individuals who did not engage in physical activity were also compared. Results: On the evaluation of 30 miRNA from individuals with a concussion between contact and non-contact sports there was high detection reliability(P<.05). Both miR-532-5p and miR-182-5p showed reduced amounts of physical activity. The miRNA-532-5p and miRNA-182-5p show significant results among 43 subjects from pre-exercise to post-exercise. The miRNA-4510 showed a significant result (p < 0.05) between contact and non-contact sport types. The amount of miRNA-4510 expanded in 20 individuals in the contact sport at post-exercise but remained normal in the non-contact sports group. Conclusion: The salivary miRNAs are reliable biomarkers for concussion. Evidence Level II; Therapeutic Studies - Investigating the results.

RESUMO Introdução: As alterações da estrutura cerebral provocadas por uma concussão relacionada ao esporte podem ser inicialmente indistinguíveis, porém os efeitos deletérios irreversíveis são notados a longo prazo. Um diagnóstico precoce poderá fornecer ao paciente uma chance maior de recuperação e aumento de sobrevida. Para tanto, estuda-se a viabilidade de um diagnóstico de concussão por biomarcadores de micro RNA (mi-RNA) contidos na saliva de esportistas. Objetivo: verificar se os miRNAs salivares são biomarcadores confiáveis para concussão esportiva. Metodologia: Os níveis de mi-RNA salivares foram determinados a partir de 120 amostras de saliva de 120 jogadores. Haviam 43 com diagnóstico de concussão e 77 sem diagnóstico de concussão. Amostras de jogadores com concussão foram coletadas 30 minutos antes da atividade, amostras de indivíduos que não praticaram atividade física também foram comparadas. Resultados: Na avaliação de 30 mi-RNA de indivíduos com concussão entre esportes de contato e sem contato houve grande confiabilidade de detecção(P<,05). Tanto o miR-532-5p quanto o miR-182-5p mostraram quantidades reduzidas na atividade física. O miRNA-532-5p e o miRNA-182-5p mostram resultados significativos entre 43 indivíduos desde o pré-exercício até o pós-exercício. O miRNA-4510 mostrou um resultado significativo (p < 0,05) entre os tipos de esporte com contato e sem contato. A quantidade de mi-RNA-4510 expandiu-se em 20 pessoas no esporte com contato no pós-exercício, mas permaneceu normal no grupo de esporte sem contato. Conclusão: Conclui-se que os miRNAs salivares são biomarcadores confiáveis para concussão. Nível de evidência II; Estudos Terapêuticos - Investigação de Resultados.

RESUMEN Introducción: Los cambios en la estructura cerebral causados por una conmoción encefálica relacionada con el deporte pueden ser inicialmente indistintos, sin embargo, los efectos deletéreos irreversibles se manifiestan a largo plazo. Un diagnóstico anticipado puede proporcionar al paciente una mayor posibilidad de recuperación y una mayor supervivencia. Por lo tanto, se estudia la viabilidad de un diagnóstico de conmoción encefálica mediante los biomarcadores de microARN (mi-ARN) contenidos en la saliva de los deportistas. Objetivo: verificar si los miARN salivales son biomarcadores fiables para la conmoción encefálica deportiva. Metodología: Se determinaron los niveles de mi-ARN salival a partir de 120 muestras de saliva de 120 jugadores. Había 43 con diagnóstico de conmoción encefálica y 77 sin diagnóstico de conmoción encefálica. Las muestras de los jugadores con conmoción encefálica se recogieron 30 minutos antes de la actividad, también se compararon las muestras de los individuos que no practicaban actividad física. Resultados: En la evaluación de 30 miRNA de individuos con conmoción encefálica entre deportes de contacto y sin contacto hubo una alta fiabilidad de detección (P<.05). Tanto miR-532-5p como miR-182-5p mostraron cantidades reducidas en la actividad física. El miRNA-532-5p y el miRNA-182-5p muestran resultados significativos entre los 43 sujetos desde antes del ejercicio hasta después del mismo. El miRNA-4510 mostró un resultado significativo (p < 0,05) entre los tipos de deporte de contacto y de no contacto. La cantidad de miARN-4510 se expandió en 20 individuos en el deporte de contacto en el momento posterior al ejercicio, pero se mantuvo normal en el grupo de deporte sin contacto. Conclusión: Llegamos a la conclusión de que los miARN salivales son biomarcadores fiables para la conmoción encefálica. Nivel de evidencia II; Estudios terapéuticos - Investigación de resultados.

The efficacy of Tai Chi for depression: A protocol for systematic review and meta-analysis.

BACKGROUND: Depression is a commonly occurring and recurrent mental disorder cross the world. Tai Chi is a traditional Chinese mind-body exercise which could be used to treat mental disorders including depression. This study aimed to conduct a systematic review and meta-analysis to assess the efficiency of Tai Chi for patients with depression. METHODS: This protocol follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol statement. Literature will be searched at PubMed, EMBASE, Web of Science, Cochrane Library, China Biology Medicine Database, China National Knowledge Infrastructure, Technology Journal Database, and Wan Fang database from the start date to September 2021. The Review Manager 5.3 software will be used to manage literature. After literature screening, 2 reviewers will extract data from the respects of general information, methodology, and results. The data analysis will be conducted with Review Manager and Stata 16 software, and the publication bias and literature quality will be both evaluated. RESULTS: The results will contain the evaluation of clinical efficacy of Tai Chi practice for depression, as well as the assessment of literature quality and publication bias. CONCLUSION: The current review will provide new evidence on whether and to what extent patients with depression can benefit from Tai Chi practice.Registration number: DOI: 10.17605/OSF.IO/AUDNQ (https://osf.io/audnq).

Evaluating the value of p70s6k and mTOR signaling pathway in monitoring exercise-induced central fatigue in rats.

Exercise leads to muscle fatigue and decreased muscle strength in response to contraction activity, and besides, it causes central fatigue. In the current study, we evaluated the value of p70s6k and mTOR signaling pathways in monitoring exercise-induced central fatigue in rats. For this purpose, 12 male rats were divided into control (n=6) and intervention (n=6) groups. The intervention group performed five sessions of climbing a one-meter ladder with a weight hanging on the tail for eight weeks. The weekly load increase was based on the mice's body weight, so it reached 30% in the first week to 200% in the eighth week. In order to evaluate central fatigue, the sedation score system was used. Forty-eight hours after the last training session, a blood sample was prepared, the expression level of related proteins was measured by the ELISA method, and the one-way ANOVA method was used for statistical analysis. This study showed that central fatigue did not significantly affect the total mTOR protein content (F=0.720, P=0.421). However, the level of phosphorylated mTOR in the intervention group had a significant difference compared to the control group (F=684.893, P=0.001, Eta2=0.988). There was a significant effect for total p70S6K content (F=5.84, P=0.04, Eta2=0.42). Also, for phosphorylated p70S6K, there was a significant difference between the mentioned groups (F=7.262, P=0.027, Eta2=0.476). In General, it was shown in this study that central fatigue is directly related to the increase in p70S6K production and phosphorylation of p70S6K and mTOR. Therefore, these two proteins can probably be evaluated for monitoring exercise-induced central fatigue, although we need more evaluations.

Immobilization of phosphorus in sediments by nano zero-valent iron (nZVI) from the view of mineral composition.

Immobilization of phosphorus (P) in sediments is essential for controlling eutrophication in natural waters. As sediment is a complex assemblages of minerals, it is necessary to explore the intrinsic mechanisms of immobilization from the view of mineral composition. In this study, nano zero-valent iron (nZVI) is used as an example to immobilize P in sediment from Tai Lake and minerals of quartz, hematite, potassium feldspar, illite, montmorillonite, calcite, and kaolin (i.e. the main components of natural sediment), to consider the role of mineral composition on P immobilization). Results show that the immobilization efficiency increases gradually with the increasing amount of adopted nZVI, until a maximum value of about 60% - 80% when 0.03-0.05 g/g of nZVI is added. Particularly, the maximum P immobilization efficiency is the highest for hematite (about 86%) due to the chemical reaction between hematite and P that inhibiting P release, followed by quartz, illite, montmorillonite, and kaolin (about 64% - 72%) which only physically adsorb P. However, the maximum P immobilization efficiency of nZVI is only 31% and 17% for potassium feldspar and calcite, respectively, due to their relatively high pH values that reducing the formation of iron (Fe)-P precipitation and inhibiting P immobilization. Thus, the P immobilization is mainly due to the reaction between nZVI/mineral and P to form FeP precipitates, followed by physical adsorption; and the particle size, elemental composition (e.g. the calcium (Ca) in calcite and Fe in hematite) and pH value also affect the P immobilization efficiency. Moreover, based on the P immobilization efficiencies for various minerals, P immobilization in sediments can be reasonably predicted from the mineral composition through methods such as component additivity.

Extracting Diameter at Breast Height with a Handheld Mobile LiDAR System in an Outdoor Environment.

Mobile laser scanning (MLS) is widely used in the mapping of forest environments. It has become important for extracting the parameters of forest trees using the generated environmental map. In this study, a three-dimensional point cloud map of a forest area was generated by using the Velodyne VLP-16 LiDAR system, so as to extract the diameter at breast height (DBH) of individual trees. The Velodyne VLP-16 LiDAR system and inertial measurement units (IMU) were used to construct a mobile measurement platform for generating 3D point cloud maps for forest areas. The 3D point cloud map in the forest area was processed offline, and the ground point cloud was removed by the random sample consensus (RANSAC) algorithm. The trees in the experimental area were segmented by the European clustering algorithm, and the DBH component of the tree point cloud was extracted and projected onto a 2D plane, fitting the DBH of the trees using the RANSAC algorithm in the plane. A three-dimensional point cloud map of 71 trees was generated in the experimental area, and estimated the DBH. The mean and variance of the absolute error were 0.43 cm and 0.50, respectively. The relative error of the whole was 2.27%, the corresponding variance was 15.09, and the root mean square error (RMSE) was 0.70 cm. The experimental results were good and met the requirements of forestry mapping, and the application value and significance were presented.

A review on sediment bioflocculation: Dynamics, influencing factors and modeling.

Sediment in a water column provides excellent substratum for microorganism colonization, and biological processes would alter the physical and chemical of sediment, resulting in substantial changes in sediment dynamics. The flocculation of sediment with biological processes are defined as sediment bioflocculation, which has been ubiquitously observed across aquatic ecosystems, activated sludge plants and bioflocculant applications, as a result of various processes involving particle aggregation and breakage under the complex effects of microorganisms and their metabolic products (e.g., extracellular polymeric substances EPS). EPS are complex high-molecular-weight mixtures of polymers, which are the primary components that hold microbial aggregates together by acting as a biological glue. Several mechanistic aggregation theories such as the alginate theory, adsorption bridging theory, divalent cation bridging theory, and Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, and a number of influencing factors (e.g., sediment properties, microbial activity, EPS quantities and components, and external environment conditions) have been proposed to elucidate the role of microorganisms and EPS in sediment aggregation, promoting the investigation of the sediment bioflocculation evolution and kinetics models. However, due to the complex interrelationships of multiple physical, chemical, and biological processes and the incomprehensive knowledge of microorganisms and EPS, considerable research should be further conducted to fully understand their precise roles in the sediment bioflocculation process. In this study, a review of dynamic characterizations, mechanism, influencing factors and models of sediment bioflocculation are given to obtain a more comprehensive understanding of sediment bioflocculation dynamics.

Effects of roughness and permeability on solute transfer at the sediment water interface.

Understanding the mechanisms of solute transfer across the sediment-water interface plays a crucial role in water quality prediction and management. In this study, different arranged particles are used to form typical rough and permeable beds. Large Eddy Simulation (LES) is used to model the solute transfer from the overlying water to sediment beds. Three rough wall turbulence regimes, i.e., smooth, transitional and rough regime, are separately considered and the effects of bed roughness on solute transfer are quantitatively analyzed. Results show that the classic laws related to Schmidt numbers can well reflect the solute transfer under the smooth regime with small roughness Reynolds numbers. Under the transitional regime, the solute transfer coefficient (KL+) is enhanced and the effect of Schmidt number is weakened by increasing roughness Reynolds number. Under the rough regime, the solute transfer is suppressed by the transition layer (Brinkman layer) and controlled by the bed permeability. Moreover, it is found that water depth, friction velocity and bed permeability can be used to estimate the solute transfer velocity (KL) under the completely rough regime.

Phosphorus adsorption onto clay minerals and iron oxide with consideration of heterogeneous particle morphology.

Particle morphology plays an important role in solid-water interface adsorption, which affects the fate and behavior of phosphorus (P) in rivers and lakes and the resulting eutrophication. In this paper, three minerals including kaolinite, montmorillonite and hematite were considered to investigate the contributions of particle morphology to P adsorption using adsorption experiments and microscopic examinations. The Taylor expansion method is applied to quantitatively characterize the heterogeneity of surface morphology. The results reveal that local concave or convex micro-morphology characterized by the second order term of Taylor expansion F2, can affect the local adsorption capacity due to its effect on the distribution of surface charge and reactive sites. Moreover, the adsorbed P at different F2 here fits to a Weibull distribution, which can further define the representative average adsorption onto individual particles. A weighted average morphology factor F2a is derived to characterize the surface heterogeneity, and correlated with average P adsorption of particular mineral particles. In addition, the Sips model can successfully fit the experimental data of different minerals, and the heterogeneity parameters γ and adsorption capacity Qm in the model are proved to be functions with the basic mineral properties, including particle size, surface site density and morphology characterization as well. It is concluded that the complex surface morphology plays a significant role in particle adsorption and the morphological role need to be considered in the adsorption model in order to better describe the adsorption in system with heterogeneous solid surface.

Analysis of biofilm bacterial communities under different shear stresses using size-fractionated sediment.

Microorganisms are ubiquitous in aqueous environments and are crucial for biogeochemical processes, but their community structures and functions remain poorly understood. In this paper, a rotating reactor was designed to study the effects of substrata and flow conditions on sediment bacterial communities using 16S rRNA gene sequencing, assaying three groups of size-fractionated sediments and three different levels of applied shear stress. Proteobacteria, Firmicutes, and Bacteroidetes were the dominant phyla of the microbial communities, with more anaerobic bacteria and opportunistic pathogens being detected under static water conditions, while more aerobic bacteria were detected under dynamic water flow conditions. Most of the top 10 genera were present in all the samples; however, there were significant differences in the species abundance. Paludibacter and Comamonadaceae_unclassified were the most abundant genera under static and dynamic conditions, respectively. Under static water conditions, the medium-grained sediment had the highest microbial diversity, followed by the fine and coarse sediments. Under dynamic water flow conditions, a higher flow velocity corresponded to a greater microbial diversity. Overall, there was no significant difference in the community richness or diversity between the static and dynamic water flow conditions. This study is beneficial for further understanding the heterogeneities of microbial communities in natural aquatic ecosystems.

Stochastic modeling of phosphorus transport in the Three Gorges Reservoir by incorporating variability associated with the phosphorus partition coefficient.

Phosphorus (P) fate and transport plays a crucial role in the ecology of rivers and reservoirs in which eutrophication is limited by P. A key uncertainty in models used to help manage P in such systems is the partitioning of P to suspended and bed sediments. By analyzing data from field and laboratory experiments, we stochastically characterize the variability of the partition coefficient (Kd) and derive spatio-temporal solutions for P transport in the Three Gorges Reservoir (TGR). We formulate a set of stochastic partial different equations (SPDEs) to simulate P transport by randomly sampling Kd from the measured distributions, to obtain statistical descriptions of the P concentration and retention in the TGR. The correspondence between predicted and observed P concentrations and P retention in the TGR combined with the ability to effectively characterize uncertainty suggests that a model that incorporates the observed variability can better describe P dynamics and more effectively serve as a tool for P management in the system. This study highlights the importance of considering parametric uncertainty in estimating uncertainty/variability associated with simulated P transport.

Effects of internal loading on phosphorus distribution in the Taihu Lake driven by wind waves and lake currents.

Wind-driven sediment resuspension exerts significant effects on the P behavior in shallow lake ecosystems. In this study, a comprehensive dynamic phosphorus (P) model that integrates hydrodynamic, wind wave and sediment transport is proposed to assess the importance of internal P cycling due to sediment resuspension on water column P levels. The primary contribution of the model is detailed modeling and rigorous coupling of sediment and P dynamics. The proposed model is applied to predict the P behavior in the shallow Taihu Lake, which is the third largest lake in China, and quantitatively estimate the effects of wind waves and lake currents on P release and distribution. Both the prevailing southeast winds in summer and northwest winds in winter are applied for the simulation, and different wind speeds of 5 m/s and 10 m/s are also considered. Results show that sediment resuspension and the resulting P release have a dominant effect on P levels in Taihu Lake, and likely similar shallow lakes. Wind-driven waves at higher wind speeds significantly enhance sediment resuspension and suspended sediment concentration (SSC). Total P concentration in the water column is also increased but not in proportion to the SSC. The different lake circulations resulting from the different prevailing wind directions also affect the distribution of suspended sediment and P around the lake ultimately influencing where eutrophication is likely to occur. The proposed model demonstrates that internal cycling in the lake is a dominant factor in the lake P and must be considered when trying to manage water quality in this and similar lakes. The model is used to demonstrate the potential effectiveness of remediation of an area where historical releases have led to P accumulation on overall lake quality.

Phosphorus adsorption on natural sediments with different pH incorporating surface morphology characterization.

Sediment samples from University Lake (U.L.) and Anacostia River (A.R.) were collected to study the phosphorus (P) adsorption with pH at 3.65, 4.75, and 5.65. The surface micro-morphology and pore structures of sediment particles were obtained using a scanning electron microscopy and gas adsorption method, respectively. Fourier analysis was then applied to approximate the surface morphology, which was incorporated into the Langmuir isotherm to directly derive the model parameters for P adsorption simulation. Meanwhile, an empirical function of pH was introduced to represent the pH effect on P adsorption. A stronger P adsorption was observed for the A.R. sediment due to the more clay minerals, smaller median diameter, and a greater percentage of large pores, and the increasing pH resulted in a decrease of adsorption equilibrium constant as well as the P adsorption capacity, which was well reproduced by the adsorption isotherms. This study would benefit the mechanism study of the interactions between sediment particles and pollutants, providing references for understanding the pollutants' transport in aqueous systems.

Environmental assessment of heavy metal transport and transformation in the Hangzhou Bay, China.

The environmental impact of heavy metal (Cu, Cd, Zn, Pb, Ni, (90)Sr and (137)Cs) transport and transformation in the Hangzhou Bay (China) was assessed through a comprehensive model that integrates hydrodynamics, sediment and heavy metal transport. A mechanistic surface complexation model was used to estimate the adsorption and desorption of heavy metal by suspended sediment under different aqueous chemistry conditions. The dynamics of metal exchange to and from the seabed was also assessed. The primary processes regulating heavy metal distribution, i.e., convection-diffusion, adsorption-desorption, sedimentation-resuspension, as well as other physical and chemical processes related to mass exchange between adjacent sediment layers, were considered in detail. The accidental discharge of (137)Cs was simulated as an example and results showed that (137)Cs transported along the coast driven by tidal flow. Most (137)Cs distributed near the outfall and accumulated in the seabed sediment. The proposed model can be a useful tool for predicting heavy metal transport and fate and provide a theoretical basis to guide field sampling, assessment of risks and the design of remediation strategies.

Mobility of phosphorus induced by sediment resuspension in the Three Gorges Reservoir by flume experiment.

The mobility of phosphorus (P) induced by sediment resuspension have been examined in a circulated flume. During the flume run, the water level and velocity were monitored, and water samples were taken for measurement of sediment and P concentrations. Peak values of both the P and sediment concentrations existed at x=4m, and then decreased slightly along the flume due to deposition. A faster P release was observed for coarser sediment, while a more sustained P release for finer sediment. Combining with the measured data from Yangtze River and sorption experiment, the relation between the load of total P (LTP) and sediment load (Qs) was estimated, and the expressions of distribution coefficient Kd and the concentration of particulate P (PP) were obtained. This study established a bridge between the small-scale sorption experiment and the field observation of natural scale, providing references for the management of contaminated sediment in natural rivers.

[Design and construction of pulsatile-flow-cultivation system for the tissue engineering heart valve].

A plane, three-dimensional chamber of pulsatile-flow-cultivation and the liquid store chamber connected by medical silica gel tube were designed and constructed by ourselves according to the design principle. The rotator pump of cardiopulmonary bypass unit was acted as the power source. The mixed gas containing 5% CO2 and 95% air was supplied through the ventilation orifice of the liquid store chamber. The temperature of these components was stabilized by thermostatic waterbath. The test of biomechanics and biological compatibility for the system was carried out by cultures experiment during two weeks. The results of the experiment showed that there was no leak in the pulsatile-flow-cultivation components in which the concentration of CO2 was controlled about 5%+1%, the temperature at 37 +/- 1 degree C, and the value of pH between 6.8 and 7.5. The flow rate of the system could be adjusted exactly between 0.125 L/min and 6.0 L/min. The endothelial cells on the viable homograft valve increased about 10 times after being cultured for 2 weeks. The cultures of cell and mould taken from the leaf and Dacron cloth of homograft valve were reported to be negative. The results of the experiment demonstrated that there was satisfactory homeostasis of these components in effective modeling pulsatile-flow-field for the implantation cells cultured, proliferated, and remodeled under the condition inferior or superior to physiological level in vitro. The system can meet the need for study of pulsatile-flow-cultivation and tissue engineering heart valve constructed in vitro.