Análisis del ciclo celular en células del cerebro como índice de crecimiento en larvas de bacalao a diferente condiciones de alimento y temperatura

The percentage of cells dividing in a specific tissue of individual larvae can be estimated by analyzing DNA per cell by flow cytometry. An experimental test was carried out with cod (Gadus morhua) larvae, with brain as the target tissue, to validate this technique as an appropriate growth index for larval fish. Standard length (SL), myotome height, and %S-phase (% of cells in the S-phase of the cell-division cycle) variability were analyzed, with temperature (6 and 10°C), food level (high- and no-food) and larval developmental stage (first feeding, pre-metamorphosis and post-metamorphosis) as independent factors. Cod larvae grew faster (in SL) and presented a higher %S-phase under high-food conditions. Larval SL increased with temperature in rearing and experimental tanks. However, there was a significant interaction between temperature and food in the %S-phase. There were no significant differences in the %S-phase between 6 and 10°C at high-food levels. We suggest that this result is a consequence of temperature-dependency of the duration of the cell cycle. In the absence of food, larvae at 10ºC had a lower %S-phase than larvae at 6°C, which may be related to increased metabolic costs with increasing temperature. Considering the effect of temperature, the mean % S-phase explained 74% of the variability in the estimated standard growth rate.El porcentaje de células en divisón en un determinado tejido de una larva de pez se puede estimar analizando la cantidad de ADN por célula mediante citometría de flujo. Se realizó un experimento con larvas de bacalao (Gadus morhua), analizando células de cerebro, para validar esta técnica como índice de crecimiento en larvas de peces. Se analizó la variabilidad de la longitud estándar (SL), la altura del tronco medida en el ano, y el %S (% de células en fase S del ciclo celular), con temperatura (6 y 10ºC), nivel de alimento (alto y sin alimento) y estado de desarrollo larvario (comienzo de la alimentación, pre-metamorfosis y post-metamorfosis) como factores independientes. Las larvas de bacalao crecieron más rápido (en SL) y presentaron mayor %S bajo condiciones de nivel alto de alimento. La SL larvaria incrementó con la temperatura. Sin embargo, se observó una interacción significativa entre temperatura y alimento sobre %S. No hubo diferencias significativas en %S entre 6 y 10ºC en condiciones de nivel alto de alimento. Sugerimos que este resultado es consecuencia de una termo-dependencia en la duración del ciclo celular. En ausencia de alimento, las larvas a 10ºC presentaron %S más bajos que las larvas a 6ºC, lo que puede estar relacionado con un incremento de los costes metabólicos a mayor temperatura. Considerando el efecto de la temperatura, el %S medio explicó el 74% de la variabilidad de la tasa de crecimiento específica estimada.

Prediction of atmospheric corrosion from meteorological parameters: Case of the atmospheric basin of the Costa Rican Western Central Valley

La evaluación de la corrosión atmosférica se basa actualmente en el estudio de las cuencas atmosféricas (AB, por sus siglas en inglés). La modelización de la corrosión atmosférica implica en muchos casos la medición de varios parámetros meteorológicos y de contaminación atmosférica, concretamente la temperatura, la humedad relativa, el cloruro y el dióxido de azufre, lo que hace más complejo el proceso de estimación. Sin embargo, para el Valle Central Occidental (WCV, por sus siglas en inglés) de Costa Rica, un AB de baja contaminación, es posible desarrollar modelos simplificados de corrosión atmosférica, basados en un pequeño número de parámetros atmosféricos. En este trabajo se analizaron las variables meteorológicas de la región de estudio en cuanto a su dependencia de la altitud y su aplicabilidad en el desarrollo de un modelo simplificado para predecir la tasa de corrosión (Vcorr). El resultado del modelo de predicción se comparó con el modelo estándar de la norma ISO 9223:2012, mostrando una mayor habilidad y dando resultados fiables para un amplio intervalo de altitudes.The assessment of atmospheric corrosion is currently based on the study of atmospheric basins (AB). Modeling atmospheric corrosion in many cases involves the measurement of several meteorological and atmospheric pollution parameters, specifically temperature, relative humidity, chloride, and sulfur dioxide, making the estimation process more complex. However, for the Western Central Valley (WCV) in Costa Rica, a low-pollution AB, it is possible to develop simplified atmospheric corrosion models based on a small number of atmospheric parameters. In this paper, the meteorological variables of the study region were analyzed in terms of their dependency on altitude and their applicability in the development of a simplified model to predict the corrosion rate (Vcorr). The output of the predictive model was compared with the standard model of ISO 9223:2012, showing a higher skill and giving reliable results for a wide interval of altitudes.Universidad de Costa Rica/[805-B8-650]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI)UCR::Vicerrectoría de Docencia::Ciencias Sociales::Facultad de Ciencias Sociales::Escuela de Geografí

Nutrient limitation can explain a rapid transition to synchrony in an upwelling-driven diatom community

Identifying the mechanisms controlling the temporal dynamics of ecological communities is key to understand their vulnerability to natural and anthropogenic impacts and to identify early warnings of critical transitions. At community level, inter-specific synchrony is an important indicator of ecosystem stability and variation in function. Using wavelet analysis on time-series of abundance of 12 dominant diatom species, sampled monthly (1994-2009) in a coastal upwelling embayment at the northern limit of the Canary Current Upwelling System, we find a sudden onset of synchrony between 1998 and 2002, concomitant with an increase in the amplitude of the upwelling index at different temporal scales. To better understand the underlying mechanism that could generate this sudden onset of synchrony among competitors, we analyzed a general model of competition between two species for two essential nutrients (e.g., nitrogen and silicate). We incorporate environmental variation by varying the concentration of one of the essential nutrients entering the system. Increase in the amplitude of environmental variation always leads to greater synchrony among competitors. This occurs because the system shifts from a state in which species are limited by different nutrients to one where species are often limited by the same nutrient. We show that the transition from asynchronous to synchronous dynamics can occur suddenly as the amplitude of environmental variation increases. While it is not possible to rule out alternative mechanisms, our model demonstrates that sudden changes in the extent of synchronization should be a common feature when species compete for essential nutrients in variable environments.En prensa3,38

A Bayesian model for anchovy (Engraulis encrasicolus): the combined forcing of man and environment

Fishery collapses frequently result from combined pressures of the environment and man, which are difficult to discern because of the complexities involved and our limited knowledge. Models to resolve this complexity often become too sophisticated, with too many assumptions and, consequently, with little capacity to predict beyond calibration data. In this paper we implement a different procedure where the model is kept simple and uncertainty accounts for the equation imperfectness to reproduce ecological complexity. Human and environmental forcing on an anchovy (Engraulis encrasicolus) stock are simulated with only six parameters plus their error terms, and the uncertainty is computed with Bayesian methods. The simple structure is able to reproduce the major dynamical features of this species in the Gulf of Ca´diz, including data on life stages and age structure that had no contact with the model. This is a distinct performance for a frugal approach working on a mid-trophic species and a positive instance where parsimony can simulate the interaction of man, fish and the environment, provided uncertainty is accounted for in the process.Publicado

Spatial and temporal patterns of sea surface chlorophyll concentration and environmental forcing in the southern European Atlantic

Phytoplankton biomass dynamic integrates information about the characteristics of the pelagic ecosystem. Temporal and spatial patterns respond to physical processes. Also, phytoplankton abundance and its temporal dynamic largely determine the structure and dynamics of the food web. The southern European Atlantic (48 ºN – 36 ºS) presents differences in continental margin orientation, upwelling intensity, river runoff, a semi-enclosed oceanic domain (Bay of Biscay), and open oceanic waters to the west. Sea surface chlorophyll concentration (SSChl) monthly averages (from satellites) from 1998 to 2012 were analysed at 4x4 km resolution by Empirical Orthogonal Functions. The study area was regionalized according to rotated EOFs and temporal modes were used to resume the SSChl temporal variability in each region. The environmental forcing of temporal modes was analysed against environmental variables by means of Canonical Correspondence Analysis. More than 50% of the variability in oceanic regions was captured by the seasonal signal, with differences in the timing of the spring bloom and with the shape of the seasonal signal related with the latitudinal gradient and the ‘stagnation effect’ of the Bay of Biscay. In French and western Iberian shelves seasonality represented 50%. The difference between shelf and oceanic regions was due to mesoscale processes in shelf areas; i.e. river runoff in the French shelf and coastal upwelling in the western Iberian shelf. Shelf mesoscale processes impose short frequency variability on to the seasonal cycle and increase SSChl levels. The influence that these patterns of spatial and temporal dynamics have on the structure and dynamics of the rest of the food web can be perceived on the spatial patterns of fisheries catches

On the monitoring of surface displacement in connection with volcano reactivation in Tenerife, Canary Islands, using space techniques

Geodetic volcano monitoring in Tenerife has mainly focused on the Las Cañadas Caldera, where a geodetic micronetwork and a levelling profile are located. A sensitivity test of this geodetic network showed that it should be extended to cover the whole island for volcano monitoring purposes. Furthermore, InSAR allowed detecting two unexpected movements that were beyond the scope of the traditional geodetic network. These two facts prompted us to design and observe a GPS network covering the whole of Tenerife that was monitored in August 2000. The results obtained were accurate to one centimetre, and confirm one of the deformations, although they were not definitive enough to confirm the second one. Furthermore, new cases of possible subsidence have been detected in areas where InSAR could not be used to measure deformation due to low coherence. A first modelling attempt has been made using a very simple model and its results seem to indicate that the deformation observed and the groundwater level variation in the island may be related. Future observations will be necessary for further validation and to study the time evolution of the displacements, carry out interpretation work using different types of data (gravity, gases, etc) and develop models that represent the island more closely. The results obtained are important because they might affect the geodetic volcano monitoring on the island, which will only be really useful if it is capable of distinguishing between displacements that might be linked to volcanic activity and those produced by other causes. One important result in this work is that a new geodetic monitoring system based on two complementary techniques, InSAR and GPS, has been set up on Tenerife island. This the first time that the whole surface of any of the volcanic Canary Islands has been covered with a single network for this purpose. This research has displayed the need for further similar studies in the Canary Islands, at least on the islands which pose a greater risk of volcanic reactivation, such as Lanzarote and La Palma, where InSAR techniques have been used already

Radiales time series: 25 years building monitoring and analytical capacities in the Iberian shelf

The RADIALES program has been monitoring shelf waters in Spain for the last 25 years. This is the oldest field program for multidisciplinary marine research addressing long term variability issues at ecosystem level. Core observations include ship-based hydrographic, biogeochemical and plankton observations at monthly frequency in several oceanographic sections along the Iberian shelf. These observations are complemented with buoy and satellite observations and all these data are used to validate hydrographic and ecological models of plankton at local and regional scales. From the first series initiated in the northwestern shelf other programs extended the observations to the Mediterranean and off shelf waters using the same approach. The success of RADIALES extends beyond pure scientific knowledge, as the expertise gathered with the program has been applied to solve multiple environmental issues, from fisheries and pollution to global change. The program is also instrumental for educational purposes, allowing the specialization of students and technicians. Thanks to a basal funding provided by the Instituto Español de Oceanografía, the program currently obtains more than 60% of its annual budget from competitive calls, as it offers an unique platform for coastal research. Among the results of this program are 400 publications, including peer-review papers, 24 Thesis and 54 scientific reports. The RADIALES data are freely distributed to national and international users as a contribution to the development of cost-effective ocean research and marine servicesIEO (RADIALES

Midwives and psychologists as profesionals to screen and prevent pregnancy-specific stress

El presente trabajo está apoyado por el Proyecto Fronteras “A-CTS-229-UGR18” de la Consejería de Economía, Conocimiento, Empresas y Universidad de la Junta de Andalucía, cofinanciado por funds/European Regional Development Fund (ERDF) - a way to build Europe.Los eventos que ocurren durante la vida fetal y perinatal pueden tener consecuencias sobre la salud y la enfermedad del neonato y del adulto. Los trabajos pioneros sobre la “Hipótesis de la Programación Fetal“ se centraron en embarazadas expuestas a una gran hambruna que ocurrió en Holanda al final de la Segunda Guerra Mundial. El ambiente intrauterino de los bebés durante esa hambruna condicionó que nacieran con un bajo peso y determinó la aparición de enfermedades cardiovasculares en ellos mismos al llegar a la edad adulta, riesgo que se trasmitió incluso a la siguiente generación. Además del estrés general que pueda sufrir una embarazada como consecuencia de la muerte de un familiar, sufrir una guerra o un desastre natural como la pandemia por el coronavirus SARS-CoV-2, existe otro tipo de estrés concreto y referido exclusivamente al proceso de embarazo: el estrés específico del embarazo. El estrés específico del embarazo es capaz de predecir de manera sensible resultados negativos maternos y neonatales. Este tipo de estrés se refiere al estrés concreto de las embarazadas en referencia a problemas médicos, la salud del recién nacido, los cambios que el embarazo va a producir en sus relaciones sociales, la posibilidad de un parto prematuro, los cambios físicos del embarazo y el miedo al parto y nacimiento. El objetivo de este artículo fue ofrecer información actualizada sobre el estrés específico del embarazo y sus consecuencias para la salud materna y neonatal. Así mismo, nos propusimos ofrecer estrategias que los profesionales sanitarios (incluidas las matronas) y los profesionales de la Psicología pudieran usar para reducir los niveles de estrés específico del embarazo. Como conclusión, afirmamos que las matronas y los profesionales de la Psicología pueden trabajar conjuntamente para reducir los niveles de estrés específico del embarazo.Events that occur during fetal and perinatal life can have consequences on the health and disease of the offspring. The pioneering work on the “Fetal Programming Hypothesis” focused on pregnant women exposed to a great famine that occurred in the Netherlands at the end of World War II. The intrauterine environment of the babies during that famine caused them to low birthweight and determined the appearance of cardiovascular diseases in themselves when they reached adulthood, a risk that was transmitted even to the following generation. In addition to the general stress that a pregnant woman may suffer as a result of the death of a family member, suffering a war or natural disaster such as the SARS-CoV-2 coronavirus, there is another specific type of stress that refers exclusively to the pregnancy process; this is the pregnancy specific-stress. Pregnancy-specific stress is capable of sensitively predicting negative maternal and neonatal outcomes. This type of stress refers to the specific stress of pregnant women related to medical problems, the health of the newborn, the changes that the pregnancy will produce in their social relationships, prematurity, physical changes of pregnancy and fear of labor and birth. The objective of this article was to offer an updated information on pregnancy-specific stress and its consequences for maternal and neonatal health. Thus, we also proposed to offer strategies that midwives and psychologists can use to reduce pregnancy-specific stress levels. In conclusion, midwives and psychologists can work together to reduce pregnancy-specific stress levels.Proyecto Fronteras “A-CTS-229-UGR18” de la Consejería de Economía, Conocimiento, Empresas y Universidad de la Junta de Andalucía, cofinanciado por funds/European Regional Development Fund (ERDF) - a way to build Europe

Melatonin uptake by cells: An answer to its relationship with glucose?

Melatonin, N-acetyl-5-methoxytryptamine, is an indole mainly synthesized from tryptophan in the pineal gland and secreted exclusively during the night in all the animals reported to date. While the pineal gland is the major source responsible for this night rise, it is not at all the exclusive production site and many other tissues and organs produce melatonin as well. Likewise, melatonin is not restricted to vertebrates, as its presence has been reported in almost all the phyla from protozoa to mammals. Melatonin displays a large set of functions including adaptation to light: dark cycles, free radical scavenging ability, antioxidant enzyme modulation, immunomodulatory actions or differentiation–proliferation regulatory effects, among others. However, in addition to those important functions, this evolutionary ‘ancient’ molecule still hides further tools with important cellular implications. The major goal of the present review is to discuss the data and experiments that have addressed the relationship between the indole and glucose. Classically, the pineal gland and a pinealectomy were associated with glucose homeostasis even before melatonin was chemically isolated. Numerous reports have provided the molecular components underlying the regulatory actions of melatonin on insulin secretion in pancreatic beta-cells, mainly involving membrane receptors MTNR1A/B, which would be partially responsible for the circadian rhythmicity of insulin in the organism. More recently, a new line of evidence has shown that glucose transporters GLUT/SLC2A are linked to melatonin uptake and its cellular internalization. Beside its binding to membrane receptors, melatonin transportation into the cytoplasm, required for its free radical scavenging abilities, still generates a great deal of debate. Thus, GLUT transporters might constitute at least one of the keys to explain the relationship between glucose and melatonin. These and other potential mechanisms responsible for such interaction are also discussed here