Nutrient fluxes through boundaries in the hypolimnion of Sau reservoir : expected patterns and unanticipated processes

By contrast to many natural lakes, the summer hypolimnion in advection-dominated systems like canyon-shaped reservoirs is not isolated from direct inputs from the river. This has important implications in the evolution of limnological features of the hypolimnion through the stratified period, especially if the river water directly plunges as a density current into the hypolimnion as a consequence of temperature differences. Taking the Sau Reservoir (Spain) as a prototype for this kind of systems, we present data from 11 years of monitoring to show how the river water entering the reservoir during summer is the main factor determining hypolimnetic nutrient concentrations. The empirical regression approach used all through the paper also stressed the effect of the improvement in water quality experienced by the river during the studied period on the improvement of the water quality stored in the summer hypolimnion of the reservoir. Since the change in river water quality was the consequence of the implementation of remediation measures at the basin scale, we advocate these solutions to manage reservoir eutrophication problems in this type of systems, which, in addition, had other unexpected benefits for the hypolimnetic water quality in Sau Reservoir.A diferencia de muchos lagos naturales, el hipolimnion que se forma en verano en sistemas dominados por la advección, como los embalses que inundan valles profundos y estrechos, no está aislado de las entradas directas desde el río. Esto tiene importantes implicaciones en la evolución de las características limnológicas del hipolimnion durante el periodo de estratificación, especialmente si el agua del río entra al embalse como una corriente de densidad directamente en el hipolimnion debido a diferencias de temperatura. Tomando el Embalse de Sau (España) como prototipo de este tipo de sistemas, mostramos 11 años de datos de un programa de monitoreo para ejemplificar cómo el agua del río que entra en verano al embalse es el factor determinante de la concentración de nutrientes en el hipolimnion. La aproximación de regresión empírica utilizada en el artículo también puso de manifiesto el efecto de la mejora en la calidad del agua que sufrió el río durante el periodo de estudio en la mejora del agua del agua embalsada en el hipolimnion. Ya que esta mejora en el río fue consecuencia de la implementación de medidas de restauración a nivel de la cuenca, promovemos estas soluciones para la gestión de problemas de eutrofización en este tipo de sistemas, que por otra parte mostraron ventajas inesperadas en el caso del hipolimnion del Embalse de Sau

Drivers of phytoplankton responses to summer wind events in a stratified lake: A modeling study

Extreme wind events affect lake phytoplankton by deepening the mixed layer and increasing internal nutrient loading. Both increases and decreases in phytoplankton concentration after strong wind events have been observed, but the precise mechanisms driving these responses remain poorly understood or quantified. We coupled a one-dimensional physical model to a biogeochemical model to investigate the factors regulating short-term phytoplankton responses to summer wind events, now and under expected warmer future conditions. We simulated physical, chemical, and biological dynamics in Lake Erken, Sweden, and found that strong wind could increase or decrease the phytoplankton concentration in the euphotic zone 1 week after the event, depending on antecedent lake physical and chemical conditions. Wind had little effect on phytoplankton concentration if the mixed layer was deep prior to wind exposure. Higher incoming shortwave radiation and hypolimnetic nutrient concentration boosted phytoplankton concentration, whereas higher surface water temperatures decreased concentrations after wind events. Medium-intensity wind events resulted in more phytoplankton than high-intensity wind. Simulations under a future climate scenario did not show marked differences in the way wind events affect phytoplankton concentration. These findings help to better understand how wind impacts vary as a function of local environmental conditions and how climate warming and changing extreme weather dynamics will affect lake ecosystems

Exposure to nitrosamines in thirdhand tobacco smoke increases cancer risk in non-smokers

In addition to passive inhalation, non-smokers, and especially children, are exposed to residual tobacco smoke gases and particles that are deposited to surfaces and dust, known as thirdhand smoke (THS). However, until now the potential cancer risks of this pathway of exposure have been highly uncertain and not considered in public health policy. In this study, we estimate for the first time the potential cancer risk by age group through non-dietary ingestion and dermal exposure to carcinogen N-nitrosamines and tobacco-specific nitrosamines (TSNAs) measured in house dust samples. Using a highly sensitive and selective analytical approach we have determined the presence of nicotine, eight N-nitrosamines and five tobacco-specific nitrosamines in forty-six settled dust samples from homes occupied by both smokers and non-smokers. Using observations of house dust composition, we have estimated the cancer risk by applying the most recent official toxicological information. Calculated cancer risks through exposure to the observed levels of TSNAs at an early life stage (1 to 6. years old) exceeded the upper-bound risk recommended by the USEPA in 77% of smokers' and 64% of non-smokers' homes. The maximum risk from exposure to all nitrosamines measured in a smoker occupied home was one excess cancer case per one thousand population exposed.The results presented here highlight the potentially severe long-term consequences of THS exposure, particularly to children, and give strong evidence of its potential health risk and, therefore, they should be considered when developing future environmental and health policies

Modelo experimental para el estudio de la ascitis en perros

The research was carried out at the Hermilio Valdizan University Huanuco - Peru, in order to make uniform the experimental model for the study of ascites in dogs, by reducing the size of the posterior vein cava, using ad hoc rings preparad from rectal probe and flexible silicone to make knowing the changas of plasma proteins and ascitic fluid during the installation of ascites. The study was conducted in 05 apparently healthy animals of different age, sex and weight. In 100% of the animals had ascites to 13.2 days ± 4, 1 and with an increase of the abdominal average perimeter of 63,4 cm with regard to the basal preoperative control of 53 cms. ± 1.2 and not happening any death in the animals. The behavior of plasmatic proteins resultad in an average decrease when they presentad the ascites of 3.30 g I di ± 0.32 with respect to preoperative found values in the 4.89 g I di± 0.35, with the fraction albumin 2.00 g I di± 0.91, which declinad from the basal level of 2.98 g I di ± 0.35 (p s 0.05), globulin increased on average in animals with ascites 1.71 g I di± 0.66 to 1.90 g I di± 0.31, while total protein was 3.30 g I di ± 0.32 in animals with ascites as opposed to 4.89 g I ± 1.20 di, who presentad preoperatively. lt is considerad as a versatile and practica! model for the study of experimental ascites in dogs, it is reduced the mortality, in addition to shortening the time it was obtained when it is comparad with the results of other surgical methods.La investigación se realizó en Universidad Hermilio Valdizán de Huánuco - Perú, con la finalidad de hacer uniforme el modelo experimental para el estudio de la ascitis en el perro, mediante la disminución del calibre de la vena cava posterior, utilizando anillos preparados ad hoc a partir de sondas rectales de silicona flexible y de dar a conocer los cambios de las proteínas plasmáticas y del liquido ascítico durante la instauración del síndrome ascítico. El estudio se realizó en 05 animales aparentemente sanos de diferente edad, sexo y peso. En el 100% de los animales presentaron la ascitis a los 13,2 días± 4, 1 y con un incremento del perímetro abdominal promedio de 63,4 cms ± 1,5 con respecto al control basal preoperatorio de 53 cms. ± 1,2 y no ocurriendo muerte alguna. El comporta­miento de las proteínas plasmáticas resultó en una disminución promedio cuando presentaron la ascitis de 3,30 g/dl ± 0,32 con respecto a los valores encontrados en el preoperatorio 4,89 g/dl ± 0,35, con la fracción albúmina de 2,00 g/dl ± 0,91, la que disminuyó con respecto al nivel basal de 2,98 g/dl ± 0,35 (pS 0,05), la globulina incrementó en promedio en los animales con síndrome ascítico de 1,71 g/dl ± 0,66 a 1,90 g/dl ± 0,31, mientras que las proteínas totales fue de 3.30 g/dl ± 0,32 en los animales con ascitis frente a 4,89 g/dl ± 1,20 que presentaron en el preoperatorio. Se considera este modelo versátil y práctico para el estudio de la ascitis experimental en el perro, reduciendo la mortalidad, además de acortar el tiempo para su obtención cuando se compara con los resultados por otros métodos quirúrgicos

Cranial biomechanics in basal urodeles: the Siberian salamander (Salamandrella keyserlingii) and its evolutionary and developmental implications

Developmental changes in salamander skulls, before and after metamorphosis, afect the feeding capabilities of these animals. How changes in cranial morphology and tissue properties afect the function of the skull are key to decipher the early evolutionary history of the crown-group of salamanders. Here, 3D cranial biomechanics of the adult Salamandrella keyserlingii were analyzed under diferent tissue properties and ossifcation sequences of the cranial skeleton. This helped unravel that: (a) Mechanical properties of tissues (as bone, cartilage or connective tissue) imply a consensus between the stifness required to perform a function versus the fxation (and displacement) required with the surrounding skeletal elements. (b) Changes on the ossifcation pattern, producing fontanelles as a result of bone loss or failure to ossify, represent a trend toward simplifcation potentially helping to distribute stress through the skull, but may also imply a major destabilization of the skull. (c) Bone loss may be originated due to biomechanical optimization and potential reduction of developmental costs. (d) Hynobiids are excellent models for biomechanical reconstruction of extinct early urodeles

The Genetic Landscape of Complex Childhood-Onset Hyperkinetic Movement Disorders

Acord transformatiu CRUE-CSICThis work was supported by an NIHR Professorship (to M.A.K.). M.A.K. has received funding from the Sir Jules Thorn Award for Biomedical Research and Wellcome Trust. B.P.-D. was supported by Instituto de Salud Carlos III, PI 18/01319 and PI21/00248, and has received funding from Beca José Castillejos (CAS14/00328). K.J.P. was supported by an MRC Clinician-Scientist Fellowship (511015) and was supported by the Dystonia Medical Research Foundation and Fight for Sight. S.S.M. has received funding from the Winston Churchill Memorial trust and Cerebral Palsy Alliance.Background and Objective: The objective of this study was to better delineate the genetic landscape and key clinical characteristics of complex, early-onset, monogenic hyperkinetic movement disorders. Methods: Patients were recruited from 14 international centers. Participating clinicians completed standardized proformas capturing demographic, clinical, and genetic data. Two pediatric movement disorder experts reviewed available video footage, classifying hyperkinetic movements according to published criteria. Results: One hundred forty patients with pathogenic variants in 17 different genes (ADCY5, ATP1A3, DDC, DHPR, FOXG1, GCH1, GNAO1, KMT2B, MICU1, NKX2.1, PDE10A, PTPS, SGCE, SLC2A1, SLC6A3, SPR, and TH) were identified. In the majority, hyperkinetic movements were generalized (77%), with most patients (69%) manifesting combined motor semiologies. Parkinsonism-dystonia was characteristic of primary neurotransmitter disorders (DDC, DHPR, PTPS, SLC6A3, SPR, TH); chorea predominated in ADCY5-, ATP1A3-, FOXG1-, NKX2.1-, SLC2A1-, GNAO1-, and PDE10A-related disorders; and stereotypies were a prominent feature in FOXG1- and GNAO1-related disease. Those with generalized hyperkinetic movements had an earlier disease onset than those with focal/segmental distribution (2.5 ± 0.3 vs. 4.7 ± 0.7 years; P = 0.007). Patients with developmental delay also presented with hyperkinetic movements earlier than those with normal neurodevelopment (1.5 ± 2.9 vs. 4.7 ± 3.8 years; P < 0.001). Effective disease-specific therapies included dopaminergic agents for neurotransmitters disorders, ketogenic diet for glucose transporter deficiency, and deep brain stimulation for SGCE-, KMT2B-, and GNAO1-related hyperkinesia. Conclusions: This study highlights the complex phenotypes observed in children with genetic hyperkinetic movement disorders that can lead to diagnostic difficulty. We provide a comprehensive analysis of motor semiology to guide physicians in the genetic investigation of these patients, to facilitate early diagnosis, precision medicine treatments, and genetic counseling. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society