Microalgae as Raw Materials for Aquafeeds: Growth Kinetics and Improvement Strategies of Polyunsaturated Fatty Acids Production.

Studies have shown that ancient cultures used microalgae as food for centuries. Currently, scientific reports highlight the value of nutritional composition of microalgae and their ability to accumulate polyunsaturated fatty acids at certain operational conditions. These characteristics are gaining increasing interest for the aquaculture industry which is searching for cost-effective replacements for fish meal and oil because these commodities are one of the most significant operational expenses and their dependency has become a bottleneck for their sustainable development of the aquaculture industry. This review is aimed at highlighting the use of microalgae as polyunsaturated fatty acid source in aquaculture feed formulations, despite their scarce production at industrial scale. Moreover, this document includes several approaches to improve microalgae production and to increase the content of polyunsaturated fatty acids with emphasis in the accumulation of DHA, EPA, and ARA. Furthermore, the document compiles several studies which prove microalgae-based aquafeeds for marine and freshwater species. Finally, the study explores the aspects that intervene in production kinetics and improvement strategies with possibilities for upscaling and facing main challenges of using microalgae in the commercial production of aquafeeds.

Understanding and managing compliance in the nature conservation context.

Nature conservation relies largely on peoples' rule adherence. However, noncompliance in the conservation context is common: it is one of the largest illegal activities in the world, degrading societies, economies and the environment. Understanding and managing compliance is key for ensuring effective conservation, nevertheless crucial concepts and tools are scattered in a wide array of literature. Here I review and integrate these concepts and tools in an effort to guide compliance management in the conservation context. First, I address the understanding of compliance by breaking it down into five key questions: who?, what?, when?, where? and why?. A special focus is given to 'why?' because the answer to this question explains the reasons for compliance and noncompliance, providing critical information for management interventions. Second, I review compliance management strategies, from voluntary compliance to coerced compliance. Finally, I suggest a system, initially proposed for tax compliance, to balance these multiple compliance management strategies. This paper differs from others by providing a broad yet practical scope on theory and tools for understanding and managing compliance in the nature conservation context.

Fluorescent transgenic mouse models for whole-brain imaging in health and disease.

A paradigm shift is occurring in neuroscience and in general in life sciences converting biomedical research from a descriptive discipline into a quantitative, predictive, actionable science. Living systems are becoming amenable to quantitative description, with profound consequences for our ability to predict biological phenomena. New experimental tools such as tissue clearing, whole-brain imaging, and genetic engineering technologies have opened the opportunity to embrace this new paradigm, allowing to extract anatomical features such as cell number, their full morphology, and even their structural connectivity. These tools will also allow the exploration of new features such as their geometrical arrangement, within and across brain regions. This would be especially important to better characterize brain function and pathological alterations in neurological, neurodevelopmental, and neurodegenerative disorders. New animal models for mapping fluorescent protein-expressing neurons and axon pathways in adult mice are key to this aim. As a result of both developments, relevant cell populations with endogenous fluorescence signals can be comprehensively and quantitatively mapped to whole-brain images acquired at submicron resolution. However, they present intrinsic limitations: weak fluorescent signals, unequal signal strength across the same cell type, lack of specificity of fluorescent labels, overlapping signals in cell types with dense labeling, or undetectable signal at distal parts of the neurons, among others. In this review, we discuss the recent advances in the development of fluorescent transgenic mouse models that overcome to some extent the technical and conceptual limitations and tradeoffs between different strategies. We also discuss the potential use of these strains for understanding disease.

Cometabolic removal of organic micropollutants by enriched nitrite-dependent anaerobic methane oxidizing cultures.

The innovative and recently discovered n-damo process, based on anaerobic methane oxidation with nitrite, was developed in a membrane-based bioreactor and evaluated in terms of organic micropollutants (OMPs) removal. The main singularity of this study consisted in the evaluation of organic micropollutants (OMPs) removal in the biological reactor. A strategy consisting on progressively increasing the nitrogen loading rate in order to increase the specific denitrification activity was followed to check if the selected OMPs were co-metabolically biotransformed. Significant nitrite removal rate (24.1 mg N L-1 d-1) was achieved after only 30 days of operation. A maximum specific removal of 186.3 mg N gVSS-1 d-1 was obtained at the end of the operation, which is one of the highest previously reported. A successfully n-damo bacteria enrichment was achieved, being Candidatus Methylomirabilis the predominant bacteria during the whole operation attaining a maximum relative abundance of about 40 %. The natural hormones (E1 and E2) were completely removed in the bioreactor. The specific removal rates of erythromycin (ERY), fluoxetine (FLX), roxithromycin (ROX) and sulfamethoxazole (SMX) were successfully correlated with the specific nitrite removal rates, suggesting a co-metabolic biotransformation.

Image Sharpness and Contrast Tuning in the Early Visual Pathway.

The center-surround organization of the receptive fields (RFs) of retinal ganglion cells highlights the presence of local contrast in visual stimuli. As RF of thalamic relay cells follow the same basic functional organization, it is often assumed that they contribute very little to alter the retinal output. However, in many species, thalamic relay cells largely outnumber their retinal inputs, which diverge to contact simultaneously several units at thalamic level. This gain in cell population as well as retinothalamic convergence opens the door to question how information about contrast is transformed at the thalamic stage. Here, we address this question using a realistic dynamic model of the retinothalamic circuit. Our results show that different components of the thalamic RF might implement filters that are analogous to two types of well-known image processing techniques to preserve the quality of a higher resolution version of the image on its way to the primary visual cortex.

Spatiotemporal variation of roadkills show mass mortality events for amphibians in a highly trafficked road adjacent to a national park, Costa Rica / Variación espacio-temporal de atropellos de vertebrados muestra eventos de mortalidad masiva de anfibios en una carretera altamente transitada adyacente a un parque nacional, Costa Rica

Abstract Roads have detrimental impacts on wildlife populations around the world. Specifically, roads pose direct and indirect threats to wildlife by limiting dispersal movements or through vehicle-related mortality. The rate of wildlife mortality varies both in time and space depending on the landscape composition and the type and use of road infrastructure. The objective of this study was to investigate spatiotemporal variation of vertebrate mortality in a 4 km segment of the 34 national road, adjacent to Carara National Park, Costa Rica. We conducted 81 roadkill surveys by car and bicycle from June 2010 to May 2011, georeferenced the locations of the kills and identified them to the lowest possible taxonomic level. We recorded a total of 4 709 road-killed animals of at least 58 species of vertebrates during the whole study. Amphibians accounted for 93.5 % of all the vertebrate losses and showed strong spatiotemporal variation of mass mortality events. Reptiles, especially snakes, were the second most affected taxon followed by mammals and birds. Relative mortality per day in the 4 km segment was 125.4 amphibians, 4.6 reptiles, 2.7 mammals, 1 bird and 0.46 undetermined. Road proximity to the border of the park, traffic volumes and lack of enforcement of speed limits may influence the high rate of roadkills found. We suggest the reinforcement of speed limits, wildlife crossing signage and the retrofitting of the existing culverts as under passes for animals to minimize vertebrate mortality at the road adjacent to Carara National Park.

Resumen Las carreteras tienen impactos perjudiciales en las poblaciones de vida silvestre en todo el mundo. Específicamente, los caminos representan amenazas directas e indirectas a la vida silvestre limitando los movimientos de dispersión, o debido a la mortalidad por atropellos por vehículos. La tasa de mortalidad de la fauna varía tanto en el tiempo como en el espacio, dependiendo de la composición del paisaje y del tipo y uso de la infraestructura vial. El objetivo de este estudio fue investigar la variación espaciotemporal de la mortalidad de vertebrados en un tramo de 4 km de la carretera nacional 34, adyacente al Parque Nacional Carara, Costa Rica. Llevamos a cabo 81 censos de vertebrados atropellados utilizando un vehículo y una bicicleta entre junio 2010 y mayo 2011, georreferenciamos las ubicaciones de los cuerpos y los identificamos al nivel taxonómico más bajo posible. Registramos un total de 4 709 animales muertos por carretera de al menos 58 especies de vertebrados durante todo el estudio. Los anfibios representaron el 93.5 % de todos los vertebrados y mostraron una fuerte variación espaciotemporal en eventos de mortalidad masiva. Los reptiles, especialmente las serpientes, fueron el segundo taxón más afectado seguido por los mamíferos y las aves. La mortalidad relativa por día en el segmento de 4 km fue de 125.4 anfibios, 4.6 reptiles, 2.7 mamíferos, 1 ave y 0.46 indeterminado. La proximidad de la carretera al límite del parque, los volúmenes de tránsito y la falta de cumplimiento de los límites de velocidad pueden influir en la alta tasa de mortalidad registrada. Sugerimos la reducción en los límites de velocidad, la señalización de cruce de vida silvestre y la readecuación de las alcantarillas existentes como pasos para los animales para minimizar la mortalidad de los vertebrados en la carretera adyacente al Parque Nacional Carara.

Validación interna de modelo predictivo creado mediante nueva metodología aplicable en la atención primaria de salud / Internal validation of a predictive model created through a new methodology applicable in primary health care

Introducción: los modelos predictivos sirven de apoyo a la toma de decisiones en salud pública. Como parte del desarrollo de estos modelos, se debe contar con alguna forma de validación interna que permita cuantificar el optimismo en su desempeño predictivo. Para esta validación, se utiliza el mismo grupo de estudio empleado para su desarrollo y los resultados son reproducibles a la población subyacente. Objetivo: validar un índice de necesidad de tratamiento ortodóntico, creado mediante una metodología que utiliza, para construir el modelo multivariante, los valores del estadígrafo V de Cramer de cada predictor. Métodos: el modelo creado con la muestra de entrenamiento, se aplicó a 181 estudiantes de una escuela primaria de Santa Clara y se calcularon medidas del desempeño discriminatorio; estas fueron: área bajo la curva Receiver Operating Characteristic y parámetros calculados a partir de las matrices de confusión. Fueron comparados los modelos obtenidos mediante el nuevo método y la regresión logística. Resultados: el nuevo modelo superó en todos los parámetros calculados a la regresión logística, con valores de sensibilidad, especificidad y validez de 79,3 %, 84,3 % y 81,2 %, respectivamente. El área bajo la curva fue de 0,886. Conclusiones: estos resultados avalan el índice obtenido mediante V de Cramer, para su utilización en la población diana subyacente. La facilidad de cálculo y comprensión de esta metodología son argumentos a favor de su uso por decisores del sector en la atención primaria de salud.

Introduction: predictive models are support tools when it comes to decision making in public health. We should count on a specific form of internal validation, as a part of the development of these models, which allows us to quantify any optimism in their predictive performance. For this validation, the same group of study employed for its performance is used, and results are reproducible to the underlying population.Objective: to validate an index of orthodontic treatment need, created by means of a methodology, that uses the values of Cramer's V of each predictor in order to build the multivariate model. Methods: the model created with the training sample was applied to 181 students from a primary school of Santa Clara, and measures of discriminatory performance were calculated, such as, area under the receiver operating characteristic curve, as well as, parameters were calculated from the confusion matrices. Models obtained by means of the new method and the logistic regression were also compared. Results: the new model exceeds logistic regression in all calculated parameters with values of sensitivity, specificity and validity of 79,3 %, 84,3 % and 81,2 %, respectively. Area under the curve was of 0,886. Conclusions: these results support the obtained index through Cramer ` V in order to be used in the underlying target population. The easiness of calculation and comprehension of this methodology are arguments in favor of its use for health decision - makers in primary care.