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Traditional Diffusion Tensor Imaging (DTI) metrics are affected by crossing fibers and lesions. Most of the previous tractometry works use the single diffusion tensor, which leads to limited sensitivity and challenging interpretation of the results in crossing fiber regions. In this work, we propose a tractometry pipeline that combines white matter tractography with multi-tensor fixel-based metrics. These multi-tensors are estimated using the stable, accurate and robust to noise Multi-Resolution Discrete Search method (MRDS). The spatial coherence of the multi-tensor field estimated with MRDS, which includes up to three anisotropic and one isotropic tensors, is tractography-regularized using the Track Orientation Density Imaging method. Our end-to-end tractometry pipeline goes from raw data to track-specific multi-tensor-metrics tract profiles that are robust to noise and crossing fibers. A comprehensive evaluation conducted in a phantom simulating healthy and damaged tissue with the standard model, as well as in a healthy cohort of 20 individuals scanned along 5 time points, demonstrates the advantages of using multi-tensor metrics over traditional single-tensor metrics in tractometry. Qualitative assessment in a cohort of patients with relapsing-remitting multiple sclerosis reveals that the pipeline effectively detects white matter anomalies in the presence of crossing fibers and lesions.

¿Qué pasaría si las razones del actual giro hacia el autoritarismo en Centroamérica no fueran el rechazo de la democracia representativa restablecida en los noventa, sino una consecuencia de los esfuerzos para restablecerla? Esta es una de las perspicaces preguntas que me quedó grabada luego de leer el libro The Coup and the Palm Trees: Agrarian Conflict and Political Power in Honduras, escrito por Andrés León Araya y publicado por la Georgia University Press. Este libro es un interesante estudio de la interacción entre los movimientos agrarios y el proceso histórico de formación del Estado hondureño, abordada desde la perspectiva de una pequeña, y en apariencia, marginalizada región hondureña y su rol crucial para explicar los orígenes del golpe militar de 2009 contra el gobierno de Manuel Zelaya Rosales. Puesto de otro modo, es una profunda mirada a los antecedentes agrarios y económico-políticos del golpe a partir de un inusual caso de estudio, cuyo objetivo (al menos parcial) es criticar la narrativa dominante de la democratización, al demostrar cómo la pacificación de Honduras de los años noventa tuvo como efecto el atrincheramiento de la explotación neoliberal, sin atender las contradicciones sociales que provocaron conflictos sociales del pasado y que hoy resurgen en medio de la autocracia, el populismo, la captura del Estado, el extractivismo y la exclusión social.

Abstract Our study explores the potential of conventional and advanced diffusion MRI techniques including diffusion tensor imaging (DTI), and single-shell 3-tissue constrained spherical deconvolution (SS3T-CSD) to investigate complex microstructural changes following severe traumatic brain injury in rats at a chronic phase. Rat brains after sham-operation or lateral fluid percussion (LFP) injury were scanned ex vivo in a 9.4 T scanner. Our region-of-interest-based approach of tensor-, and SS3T-CSD derived fixel-, 3-tissue signal fraction maps were sensitive to changes in both white matter (WM) and grey matter (GM) areas. Tensor-based measures, such as fractional anisotropy (FA) and radial diffusivity (RD), detected more changes in WM and GM areas as compared to fixel-based measures including apparent fiber density (AFD), peak FOD amplitude and primary fiber bundle density, while 3-tissue signal fraction maps revealed distinct changes in WM, GM, and phosphate-buffered saline (PBS) fractions highlighting the complex tissue microstructural alterations post-trauma. Track-weighted imaging demonstrated changes in track morphology including reduced curvature and average pathlength distal from the primary lesion in severe TBI rats. In histological analysis, changes in the diffusion MRI measures could be associated to decreased myelin density, loss of myelinated axons, and increased cellularity, revealing progressive microstructural alterations in these brain areas five months after injury. Overall, this study highlights the use of combined conventional and advanced diffusion MRI measures to obtain more precise insights into the complex tissue microstructural alterations in chronic phase of severe brain injury.

Abstract This article presents a comparison between two cases in which there was a need for revision of total hip arthroplasty due to aseptic acetabular failure. We used 3D prototyping in one of the cases to perform an unconventional technique of molding synthesis material before the procedure to evaluate the time saved in the transoperative period in complex cases.

Estimating structural connectivity from diffusion-weighted magnetic resonance imaging is a challenging task, partly due to the presence of false-positive connections and the misestimation of connection weights. Building on previous efforts, the MICCAI-CDMRI Diffusion-Simulated Connectivity (DiSCo) challenge was carried out to evaluate state-of-the-art connectivity methods using novel large-scale numerical phantoms. The diffusion signal for the phantoms was obtained from Monte Carlo simulations. The results of the challenge suggest that methods selected by the 14 teams participating in the challenge can provide high correlations between estimated and ground-truth connectivity weights, in complex numerical environments. Additionally, the methods used by the participating teams were able to accurately identify the binary connectivity of the numerical dataset. However, specific false positive and false negative connections were consistently estimated across all methods. Although the challenge dataset doesn’t capture the complexity of a real brain, it provided unique data with known macrostructure and microstructure ground-truth properties to facilitate the development of connectivity estimation methods.

En el ensayo La representación sin estereotipos de los varones homosexuales en las redes sociales. Caso: ¿Por qué no seguiste? se trata de evidenciar como un producto audiovisual creado por un colectivo peruano ha contribuido a la representación de diversas formas de ser gay en la producción peruana y latinoamericana. Esto se hace evidente en la construcción de los personajes y las narrativas de la serie web difundida por las redes sociales.

Background Land use is a major factor determining stream water physicochemistry. However, most streams move from one land use type to another as they drain their watersheds. Here, we studied three land use scenarios in a tropical cloud forest zone in Mexico. We addressed three main goals, to: (1) assess how land use scenarios generate different patterns in stream physicochemical characteristics; (2) explore how seasonality (i.e., dry, dry-to-wet transition, and wet seasons) might result in changes to those patterns over the year; and (3) explore whether physicochemical patterns in different scenarios resulted in effects on biotic components (e.g., algal biomass). Methods We studied Tropical Mountain Cloud Forest streams in La Antigua watershed, Mexico. Streams drained different three scenarios, streams with (1) an upstream section draining forest followed by a pasture section (F-P), (2) an upstream section in pasture followed by a forest section (P-F), and (3) an upstream forest section followed by coffee plantation (F-C). Physicochemistry was determined at the upstream and downstream sections, and at the boundary between land uses. Measurements were seasonal, including temperature, dissolved oxygen, conductivity, and pH. Water was analyzed for suspended solids, alkalinity, silica, chloride, sulfate, magnesium, sodium, and potassium. Nutrients included ammonium, nitrate, and phosphorus. We measured benthic and suspended organic matter and chlorophyll. Results Streams presented strong seasonality, with the highest discharge and suspended solids during the wet season. Scenarios and streams within each scenario had distinct physicochemical signatures. All three streams within each scenario clustered together in ordination space and remained close to each other during all seasons. There were significant scenario-season interactions on conductivity (F = 9.5, P < 0.001), discharge (F = 56.7, P < 0.001), pH (F = 4.5, P = 0.011), Cl− (F = 12.2, P < 0.001), SO42− (F = 8.8, P < 0.001) and NH4+ (F = 5.4, P = 0.005). Patterns within individual scenarios were associated with stream identity instead of land use. Both P-F and F-C scenarios had significantly different physicochemical patterns from those in F-P in all seasons (Procrustes analysis, m12 = 0.05–0.25; R = 0.86–0.97; P < 0.05). Chlorophyll was significantly different among scenarios and seasons (F = 5.36, P = 0.015, F = 3.81, P = 0.42, respectively). Concentrations were related to physicochemical variables more strongly during the transition season. Conclusion Overall, land use scenarios resulted in distinctive water physicochemical signatures highlighting the complex effects that anthropogenic activities have on tropical cloud forest streams. Studies assessing the effect of land use on tropical streams will benefit from assessing scenarios, rather than focusing on individual land use types. We also found evidence of the importance that forest fragments play in maintaining or restoring stream water physicochemistry.

Focal cortical dysplasias are a type of malformations of cortical development that are a common cause of drug-resistant focal epilepsy. Surgical treatment is a viable option for some of these patients, with their outcome being highly related to complete surgical resection of lesions visible in magnetic resonance imaging (MRI). However, subtle lesions often go undetected on conventional imaging. Several methods to analyze MRI have been proposed, with the common goal of rendering subtle cortical lesions visible. However, most image-processing methods are targeted to detect the macroscopic characteristics of cortical dysplasias, which do not always correspond to the microstructural disarrangement of these cortical malformations. Quantitative analysis of diffusion-weighted MRI (dMRI) enables the inference of tissue characteristics, and novel methods provide valuable microstructural features of complex tissue, including gray matter. We investigated the ability of advanced dMRI descriptors to detect diffusion abnormalities in an animal model of cortical dysplasia. For this purpose, we induced cortical dysplasia in 18 animals that were scanned at 30 postnatal days (along with 19 control animals). We obtained multi-shell dMRI, to which we fitted single and multi-tensor representations. Quantitative dMRI parameters derived from these methods were queried using a curvilinear coordinate system to sample the cortical mantle, providing inter-subject anatomical correspondence. We found region- and layer-specific diffusion abnormalities in experimental animals. Moreover, we were able to distinguish diffusion abnormalities related to altered intra-cortical tangential fibers from those associated with radial cortical fibers. Histological examinations revealed myelo-architectural abnormalities that explain the alterations observed through dMRI. The methods for dMRI acquisition and analysis used here are available in clinical settings and our work shows their clinical relevance to detect subtle cortical dysplasias through analysis of their microstructural properties.

Diffusion-weighted magnetic resonance imaging (DW-MRI) is a non-invasive technique that is sensitive to microstructural geometry in neural tissue and is useful for the detection of neuropathology in research and clinical settings. Tensor-valued diffusion encoding schemes (b-tensor) have been developed to enrich the microstructural data that can be obtained through DW-MRI. These advanced methods have proven to be more specific to microstructural properties than conventional DW-MRI acquisitions. Additionally, machine learning methods are particularly useful for the study of multidimensional data sets. In this work, we have tested the reach of b-tensor encoding data analyses with machine learning in different histopathological scenarios. We achieved this in three steps: 1) We induced different levels of white matter damage in rodent optic nerves. 2) We obtained ex vivo DW-MRI data with b-tensor encoding schemes and calculated quantitative metrics using Q-space trajectory imaging. 3) We used a machine learning model to identify the main contributing features and built a voxel-wise probabilistic classification map of histological damage. Our results show that this model is sensitive to characteristics of microstructural damage. In conclusion, b-tensor encoded DW-MRI data analyzed with machine learning methods, have the potential to be further developed for the detection of histopathology and neurodegeneration.

The objective of the research was to evaluate three synchronization protocols for fixed-time artificial insemination (FTAI) in Bos indicus with Bos taurus crossbred cows. Forty-five cows of 5 ± 1.6 years were selected. The Jsynch treatment consisted of the application of an intravaginal device plus benzoate; on day 8, the device was removed and PGF2α, estradiol cypionate plus eCG was applied, and the FTAI was performed at 48–52 hours after. Conventional treatment consisted of the application of an intravaginal device plus benzoate; on day 8, the device was removed and PGF2α plus eCG was injected, and on day 9, estradiol benzoate was administered, and FTAI was performed at 30 hours. The Ovsynch treatment consisted of the application of GnRH, and on day 8, PGF2α was applied, on day 9, GnRH was applied again, and on day 10, FTAI plus GnRH was applied. The diagnosis of pregnancy was determined by transrectal ultrasound 45 days after the FTAI. The Jsynch (39.1%) and conventional (39.1%) treatment showed higher pregnancy compared to the Ovsynch treatment (21.7%) of pregnancy. The presence of crystalline mucus at the time of the FTAI was significantly associated with pregnancy. The results of this investigation indicate that it is possible to obtain acceptable pregnancy rates with the FTAI in B. indicus with B. taurus crossbred milk-producing cows, and treatments with progesterone-releasing devices plus eCG can improve the reproductive performance of cows.

El objetivo del ensayo fue evaluar el efecto de Centrosema (Centrosema macrocarpum) y Nudillo (Brachiaria mutica) en el rendimiento productivo de cuyes mejorados en la etapa de recría. Se evaluaron cuatro tratamientos, T1: 100% Nudillo; T2: 75% Nudillo y 25% Centrosema; T3: 25% Nudillo y 75% Centrosema y T4: 100% Centrosema, utilizándose 32 cuyes machos y hembras que fueron distribuidos bajo el Diseño de bloques completamente al azar con arreglo factorial de 2 (sexo) por 4 (tratamiento). Se encontró diferencias (P

It is unclear whether stream detritivore diversity enhances decomposition across climates. Here the authors manipulate litter diversity and examine detritivore assemblages in a globally distributed stream litterbag experiment, finding a positive diversity-decomposition relationship stronger in tropical streams, where detritivore diversity is lower.

This study developed a method to approximate the covariance matrix associated with the simulation of water molecular diffusion inside the brain tissue. The computation implements the Discontinuous Galerkin method of the diffusion equation. A physically consistent numerical flux is applied to model the interaction between the axon walls and extracellular regions. This numerical flux yields an efficient GPU-CUDA implementation. We consider the two-dimensional case of high axon pack density, valid, for instance, in the brain's corpus callosum region.

Abstract Disturbances can alter the structure and function of ecosystems. In stream ecosystems, changes in discharge and physicochemistry at short, intermediate, and long recurrence intervals can affect food webs and ecosystem processes. In this paper, we compare pH regimes in streams at La Selva Biological Station, Costa Rica, where episodic acidification frequency across the stream network varies widely due to buffering from inputs of bicarbonate‐rich interbasin groundwater. To examine the effects of acidification on ecosystem structure and function, we experimentally increased the buffering capacity of a headwater stream reach and compared it to an unbuffered upstream reach. We compared these reaches to a naturally buffered and unbuffered reaches of a second headwater stream. We quantified ecosystem structural (macroinvertebrate assemblages on leaf litter and coarse woody debris) and functional responses (leaf litter and coarse woody debris decomposition rates, and growth rates of a focal insect taxon [Diptera: Chironomidae]). Non‐metric multidimensional scaling and analysis of similarity revealed that macroinvertebrate assemblages were relatively homogenous across the four study reaches, although the naturally buffered reach was the most dissimilar. Ecosystem function, as measured by chironomid growth rates, was greater in the naturally buffered reach, while decomposition rates did not differ across the four reaches. Our results indicate that biological assemblages are adapted to pH regimes of frequently acidified stream reaches. Our experiment informs the effects on structure and function at short time scales in streams that experience moderate acidification, but larger magnitude acidification events in response to hydroclimatic change, as projected under climate change scenarios, may induce stronger responses in streams.

La sección temática del volumen 11 del Anuario del Centro de Investigación y Estudios Políticos tiene como propósito estudiar la compleja tensión entre la imagen de responsabilidad ambiental y armonía social que Costa Rica proyecta al proyecta al mundo y su conflictiva realidad a la hora de balancear entre sostenibilidad ambiental, justicia social y el desarrollo económico. Los artículos que componen esta sección exploran las múltiples dimensiones de esta confrontación y la forma en que esta se desenvuelve en una variedad de sectores, incluyendo el desarrollo agropecuario, la conservación ambiental, la producción energética, el turismo y las políticas sobre cambio climático. Sabemos bien que dilemas y conflictos similares suceden en otros países alrededor del mundo, pero Costa Rica es un caso especial. Aunque es un país pequeño y no muy importante en la geopolítica global, históricamente, ha asumido un rol crítico como sitio de experimentación de políticas para el desarrollo sostenible. Esto ha reforzado la idea de Costa Rica como un lugar “excepcional”, previamente sustentada por la presencia de un sistema democrático progresivo, en una región caracterizada por el conflicto armado y el autoritarismo. Esta introducción ofrece un contexto económico-político de las formas peculiares en que Costa Rica ha sido construida discursivamente como un lugar excepcional a escala global

White matter bundle segmentation using diffusion MRI fiber tractography has become the method of choice to identify white matter fiber pathways in vivo in human brains. However, like other analyses of complex data, there is considerable variability in segmentation protocols and techniques. This can result in different reconstructions of the same intended white matter pathways, which directly affects tractography results, quantification, and interpretation. In this study, we aim to evaluate and quantify the variability that arises from different protocols for bundle segmentation. Through an open call to users of fiber tractography, including anatomists, clinicians, and algorithm developers, 42 independent teams were given processed sets of human whole-brain streamlines and asked to segment 14 white matter fascicles on six subjects. In total, we received 57 different bundle segmentation protocols, which enabled detailed volume-based and streamline-based analyses of agreement and disagreement among protocols for each fiber pathway. Results show that even when given the exact same sets of underlying streamlines, the variability across protocols for bundle segmentation is greater than all other sources of variability in the virtual dissection process, including variability within protocols and variability across subjects. In order to foster the use of tractography bundle dissection in routine clinical settings, and as a fundamental analytical tool, future endeavors must aim to resolve and reduce this heterogeneity. Although external validation is needed to verify the anatomical accuracy of bundle dissections, reducing heterogeneity is a step towards reproducible research and may be achieved through the use of standard nomenclature and definitions of white matter bundles and well-chosen constraints and decisions in the dissection process.

¿Cuáles son las posibilidad reales de que las negociaciones sobre el cambio climático ofrezcan una solución real a este problema? ¿Qué proyecciones de éxito podemos hacernos con base en los nuevos instrumentos para abordar el cambio climático sugeridos en las COP de Copenhague 2009 y Paris 2015? ¿Son estos instrumentos innovaciones reales en la gobernanza ambiental global o nuevas e inefectivas "palabras de moda" en la cooperación para el desarrollo sostenible? En sencillo, ¿cómo sabemos que la discusión global sobre el cambio climático no es discurso político vacío destinado a proponer acciones tangibles respecto a un futuro incierto? Las diferentes contribuciones del libro Globalising the climate: COP21 and the climatization of global debates ofrecen interesantes e innovadoras respuestas a estas enormes preguntas existenciales de hoy.

The species Chironomus sp. "Florida" has several qualities that make it a potential aquatic laboratory model to be used in Puerto Rico. Its use as such, however, requires a rearing protocol and life cycle description not previously reported. The present study addresses this lack of information by first describing a rearing method obtained through three years of observations. Next we describe and discuss the life cycle and the effects of temperature and feeding on development. The species has a short life cycle (typically 11 days) and larval stages easily identified using body measurements. Temperature affects the duration of the life cycle, with warm temperatures producing faster development than cold temperatures. The effects of different food concentrations vary: in large water volumes, concentrations of 2 mg/larva/day produce faster developmental times, but at low water volumes, small food concentrations of 0.5 mg/larva/day produce faster developmental times. The rearing protocol and life cycle parameters presented in this study are intended to promote the use of this species as a laboratory model. The fast development of Chironomus sp. "Florida" makes it ideal for toxicological studies.

Background Conservation of tropical freshwater fauna requires a solid understanding of species biodiversity patterns. We provide an up to date annotated list of Odonata of Puerto Rico, which is based on current reports. The list is complemented with notes on the geographic and altitudinal distribution of this order on the island. We also compare current composition relative to early reports conducted when Puerto Rico was mostly an agricultural region. Methods We surveyed adult Odonata all over Puerto Rico with the aid of undergraduate students. Students were trained on capturing, preserving, and data basing specimens. All material was centralized, identified by the lead author, and deposited in the Zoology Museum at the University of Puerto Rico (MZUPR), Río Piedras campus. Surveys were complemented with focal collections by the authors and a literature review of published records for Puerto Rico and the Caribbean. We requested records from specialists to obtain the most complete list of species for the island. Results An annotated list of Odonata from Puerto Rico is presented, reporting 49 species distributed in two suborders and four families. We provide information on species distribution among municipalities and elevations around Puerto Rico. A historic list of species was developed for the 1930s-1940s, when agriculture covered most of Puerto Rico, based on literature and museum specimens. Both current and historic records are similar and suggest that the Odonata fauna is dominated by generalist species and has changed little since the agricultural period. Our list provides a point of reference to understand biodiversity patterns in Puerto Rico and the Caribbean and for assessing the effects of land use change on aquatic insect diversity.

Background Hydrological impacts on aquatic biota have been assessed in numerous empirical studies. Aquatic insects are severely affected by population declines and consequent diversity loss. However, many uncertainties remain regarding the effects of hydrology on insect production and the consequences of energy transfer to the terrestrial ecosystem. Likewise, sublethal effects on insect morphology remain poorly quantified in highly variable environments. Here, we characterized monthly fluctuation in benthic and emerged biomass of Ephemeroptera in a tropical lowland stream. We quantified the proportion of mayfly production that emerges into the riparian forest. We also examined the potential morphological changes in Farrodes caribbianus (the most abundant mayfly in our samples) due to environmental stress. Methods We collected mayflies (nymphs and adults) in a first-order stream in Costa Rica. We compared benthic and adult biomass from two years’ worth of samples, collected with a core sampler (0.006 m2) and a 2 m2-emergence trap. The relationship between emergence and annual secondary production (E/P) was used to estimate the Ephemeroptera production that emerged as adults. A model selection approach was used to determine the relationship between environmental variables that were collected monthly and the emergent biomass. To determine potential departures from perfect bilateral symmetry, we evaluated the symmetry of two morphological traits (forceps and forewing) of F. caribbianus adults. We used Spearman’s rank correlation coefficients (ρ) to examine potential changes in adult body length as a possible response to environmental stress. Results Benthic biomass was variable, with peaks throughout the study period. However, peaks in benthic biomass did not lead to increases in mayfly emergence, which remained stable over time. Relatively constant mayfly emergence suggests that they were aseasonal in tropical lowland streams. Our E/P estimate indicated that approximately 39% and 20% (for 2002 and 2003, respectively) of the nymph production emerged as adults. Our estimated proportion of mayfly production transferred to terrestrial ecosystems was high relative to reports from temperate regions. We observed a strong negative response of F. caribbianus body length to increased hydrology (Spearman: ρ = −0.51, p < 0.001), while slight departures from perfect symmetry were observed in all traits. Conclusion Our two years study demonstrates that there was large temporal variability in mayfly biomass that was unrelated to hydrological fluctuations, but potentially related to trophic interactions (e.g., fish predation). Body length was a good indicator of environmental stress, which could have severe associated costs for mayfly fitness in ecosystems with high temporal variation. Our results highlight the complex ecological and evolutionary dynamics of tropical aquatic insects, and the intricate connection between aquatic and terrestrial ecosystems.

Monte-Carlo Diffusion Simulations (MCDS) have been used extensively as a ground truth tool for the validation of microstructure models for Diffusion-Weighted MRI. However, methodological pitfalls in the design of the biomimicking geometrical configurations and the simulation parameters can lead to approximation biases. Such pitfalls affect the reliability of the estimated signal, as well as its validity and reproducibility as ground truth data. In this work, we first present a set of experiments in order to study three critical pitfalls encountered in the design of MCDS in the literature, namely, the number of simulated particles and time steps, simplifications in the intra-axonal substrate representation, and the impact of the substrate's size on the signal stemming from the extra-axonal space. The results obtained show important changes in the simulated signals and the recovered microstructure features when changes in those parameters are introduced. Thereupon, driven by our findings from the first studies, we outline a general framework able to generate complex substrates. We show the framework's capability to overcome the aforementioned simplifications by generating a complex crossing substrate, which preserves the volume in the crossing area and achieves a high packing density. The results presented in this work, along with the simulator developed, pave the way toward more realistic and reproducible Monte-Carlo simulations for Diffusion-Weighted MRI.

Aumentos en la ocurrencia y persistencia de sequías alrededor del mundo estimulan el entendimiento de sus efectos en las poblaciones naturales y funcionamiento del ecosistema. El principal resultado de las sequías en los ríos es la fragmentación del ecosistema riverino en pozas aisladas a medida que el flujo y la profundidad del agua disminuyen. Hay estudios limitados sobre la respuesta de los tricópteros a reducciones en niveles de agua y su efecto en el funcionamiento del ecosistema. El objetivo de este estudio fue evaluar como reducciones en niveles del agua, similar a las asociadas con sequías, influencian la alimentación y comportamiento conspecífico de Phylloicus pulchrus. Reducciones de pozas en laboratorio simulando condiciones naturales fueron empleadas por dos semanas. Cuatro acuarios plásticos rectangulares fueron llenados a una tercera parte con agua aereada de la quebrada. Dentro de cada acuario se colocaron diez cámaras plásticas circulares (con aperturas de malla) con hojas senescentes de Guarea guidonea. Se simularon dos niveles de pozas (normal y bajo) con dos tratamientos (experimental y control). Las cámaras experimentales (n=20) contenían larvas del cuarto estadío (n=80, 40=normal, 40=bajo) mientras que las del control (n=20) no. Se evaluó el efecto de la reducción de pozas en la pérdida de masa de las hojas, interacciones agresivas (>25 % de su envoltura removida) y mortalidad larval. La reducción en el nivel de las pozas aumentó la pérdida de masa de las hojas (ANOVA: F=5.17, p=0.03), interacciones agresivas (Chi cuadrado: x2=6.24, n=80, p= 0.01), y mortalidad larval (Chi square: x2=4.51, n=80, p= 0.03). Este estudio muestra la respuesta temprana de un tricóptero tropical a una señal abiótica de un cambio ambiental drástico. Esta investigación contribuye al escaso conocimiento sobre el comportamiento de procesamiento de hojarasca en larvas de tricópteros durante etapas tempranas de reducciones de flujo, como las causadas por sequías.

La degradación de los sistemas ribereños, por causa de las actividades humanas, ha permitido el desarrollo de numerosos métodos que evalúan la severidad de los impactos antropogénicos. Los protocolos de biomonitoreo, empleando macroinvertebrados acuáticos, son usados mundialmente en estas evaluaciones. No obstante, estos métodos tienen la desventaja que solo evalúan el canal del río, ignorando la zona ribereña adyacente. Otros métodos consideran, en su evaluación, las características físicas de ambas zonas, pero ignoran la biota del lugar. Las arañas ribereñas se han discutido como potenciales bioindicadores dado que podrían proveer una alternativa más holística para evaluar los sistemas ribereños. Nuestro objetivo fue determinar si los cambios en las comunidades de arañas ribereñas podrían utilizarse para separar lugares con diferentes niveles de impacto. Se correlacionó el porcentaje de cobertura vegetal y diferentes protocolos de biomonitoreo, con métricas de riqueza y abundancia de arañas a lo largo de un gradiente urbano. Se encontraron diferencias en la composición de la comunidad de arañas entre lugares, con una tendencia general de menor riqueza y menor abundancia en los sitios más impactados. La abundancia de las arañas se correlacionó significativamente con el porcentaje de cobertura vegetal y la riqueza de familias se correlacionó con dos de los protocolos de monitoreo usados. Estos hallazgos respaldan la utilización de las comunidades de arañas como indicadoras de disturbio en los ecosistemas ribereños de Puerto Rico. Sugerimos incorporar las comunidades de arañas ribereñas en futuros protocolos de biomonitoreo para asegurar una visión más holística de las condiciones de los lugares evaluados.

Diffusion-weighted magnetic resonance imaging (dMRI) is widely used to infer microstructural characteristics of tissue, particularly in cerebral white matter. Histological validation of the metrics derived from dMRI methods are needed to fully characterize their ability to capture biologically-relevant histological features non-invasively. The data described here were used to correlate metrics derived from dMRI and quantitative histology in an animal model of axonal degeneration (“Histological validation of per-bundle water diffusion metrics within a region of fiber crossing following axonal degeneration” [1]). Unilateral retinal ischemia/reperfusion was induced in 10 rats, by the elevation of pressure of the anterior chamber of the eye for 90 min. Five rats were used as controls. After five weeks, injured animals were intracardially perfused to analyze the optic nerves and chiasm with dMRI and histology. This resulted in 15 brain scans, each with 80 diffusion-sensitizing gradient directions with b = 2000 and 2500 s/mm2 and 20 non-diffusion-weighted images (b = 0 s/mm2), with isometric voxel resolution of 125 μm3. Histological sections were obtained after dMRI. Optical microscopy photomicrographs of the optic nerves (stained with toluidine blue) are available, as well as their corresponding automatic segmentations of axons and myelin. Keywords: Diffusion, Magnetic resonance imaging, Axonal degeneration, Crossing fibers, Retinal ischemia, Microstructure

Los nematodos son simbiontes comunes en los insectos acuáticos. Aquí evaluamos la presencia de nematodos en ninfas de Ephemeroptera, determinamos su prevalencia en la población y los factores asociados a la presencia del nematodo. Se colectaron ninfas (n = 130) de Ephemeroptera de tres microhábitats de río (rápidos, pozas, y rocas) usando una red D, en la quebrada Prieta, Estación de Campo El Verde, Puerto Rico. Se disectaron las ninfas y la presencia del nematodo fue determinada bajo microscopio de luz (4 x y 10 x). La prevalencia del nematodo fue de 50 %. Los nematodos presentes no fueron identificados más allá del nivel de Filo, pero se rechazaron varios grupos (Nematoda: Mermithidae y Nematomorpha: Gordiida). Los nematodos fueron más comunes en el abdomen, cabeza y tórax de los efemerópteros. Hubo diferencias en infección entre taxa, Neohagenulus fue el grupo con la mayor proporción de infección. La forma del cuerpo, estrategias de alimentación, o actividad de las ninfas, pueden potencialmente explicar las diferencias en infección entre taxa. No hubo diferencias de infección entre hábitats, pero los efemerópteros fueron menos abundantes en los rápidos; tampoco se observó una relación entre la longitud de los efemerópteros y la cantidad de nematodos presentes. Según nuestra información, este es el primer reporte de un nematodo en ninfas efemerópteras en Puerto Rico.

Understanding how environmental variables influence the distribution and density of organisms over relatively long temporal scales is a central question in ecology given increased climatic variability (e.g., precipitation, ENSO events). The primary goal of our study was to evaluate long-term (15y time span) patterns of climate, as well as environmental parameters in two Neotropical streams in lowland Costa Rica, to assess potential effects on aquatic macroinvertebrates. We also examined the relative effects of an 8y whole-stream P-enrichment experiment on macroinvertebrate assemblages against the backdrop of this long-term study. Climate, environmental variables and macroinvertebrate samples were measured monthly for 7y and then quarterly for an additional 8y in each stream. Temporal patterns in climatic and environmental variables showed high variability over time, without clear inter-annual or intra-annual patterns. Macroinvertebrate richness and abundance decreased with increasing discharge and was positively related to the number of days since the last high discharge event. Findings show that fluctuations in stream physicochemistry and macroinvertebrate assemblage structure are ultimately the result of large-scale climatic phenomena, such as ENSO events, while the 8y P-enrichment did not appear to affect macroinvertebrates. Our study demonstrates that Neotropical lowland streams are highly dynamic and not as stable as is commonly presumed, with high intra- and inter-annual variability in environmental parameters that change the structure and composition of freshwater macroinvertebrate assemblages.

Interspecific interactions can play an important role in determining habitat selection and resource use between competing species. We examined interactions between an omnivorous shrimp and a grazing mayfly, two co-dominant taxa found in Puerto Rican headwater streams, to assess how predator presence may influence mayfly resource use and instantaneous growth in a tropical rainforest ecosystem. We conducted a series of behavioral and growth experiments to determine the effects of the freshwater shrimp, Xiphocaris elongata, on the growth rate and resource selection of mayfly nymphs in the family Leptophlebiidae. For resource choice assessments, we conducted a series of five day laboratory experiments where mayflies were given access to two resource substrate choices (cobble vs. leaves) in the presence or absence of shrimp. To assess for the effects of shrimp on mayfly fitness, we measured mayfly growth in laboratory aquaria after five days using four treatments (cobble, leaves, cobble + leaves, no resource) in the presence or absence of shrimp. In resource choice experiments, mayflies showed preference for cobble over leaf substrata (p

El uso de la tierra influye significativamente sobre los procesos en ecosistemas de riachuelo, como la descomposición de la hojarasca. En el presente estudio, se evaluaron las tasas de descomposición de la hojarasca en arroyos tropicales menores de zonas boscosa, agrícola y urbana en Puerto Rico. Para medir las tasas de descomposición se colocaron bolsas de malla gruesa en nueve riachuelos, tres para cada uno de los tipos de uso de tierra. Se midieron los cambios en la masa de hojarasca con el tiempo, las tasas de descomposición, la composición de macroinvertebrados y los aspectos fisico-químicos del riachuelo. Los riachuelos mostraron diferencias en la fisico-química del agua: los riachuelos urbanos presentaron los valores más altos en casi todas las variables. Las características físicas del riachuelo fueron evaluadas utilizando un protocolo visual, el cual indica que los riachuelos urbanos y asociados a la agricultura están más degradados que los asociados a bosques. La tasa de descomposición de la hojarasca fue rápida en todos los riachuelos (k=0.006-0.024). La descomposición estuvo relacionada con las condiciones físicas del riachuelo, siendo más rápido en aquellos asociados al bosque. Los invertebrados que colonizaron las hojas fueron principalmente efemerópteros (Leptophlebiidae, Baetidae, and Caenidae), dípteros (Chironomidae), tricópteros (Polycentropodidae) y escarabajos (Elmidae and Gyrinidae). Contrario a lo encontrado en otros estudios, no hallamos decápodos. Hubo poca evidencia de que los insectos afecten la descomposición. Los resultados sugieren que el uso de la tierra es un factor importante que afecta el proceso de descomposición de la hojarasca en los riachuelos. Contrario a los estudios en zonas templadas, hallamos evidencia de una relación positiva de los nutrientes de tierra agrícola con las tasas de descomposición. Los cambios en las características físicas de los riachuelos parecen ser los factores principales en los patrones de descomposición.

Aquatic macroinvertebrates are involved in numerous processes within aquatic ecosystems. They often have important effects on ecosystem processes such as primary production (via grazing), detritus breakdown, and nutrient mineralization and downstream spiraling. The functional feeding groups (FFG) classification was developed as a tool to facilitate the incorporation of macroinvertebrates in studies of aquatic ecosystems. This classification has the advantage of combining morphological characteristics (e.g., mouth part specialization) and behavioral mechanisms (e.g., way of feeding) used by macroinvertebrates when consuming resources. Although recent efforts have greatly advanced our ability to identify aquatic macroinvertebrates, there is limited information on FFG assignment. Furthermore, there has been some variation in the use of the FFG classification, in part due to an emphasis on using gut content analysis to assign FFG, which is more appropriate for assigning trophic guilds. Thus, the main goals of this study are to (1) provide an overview of the value of using the FFG classification, (2) make an initial attempt to summarize available information on FFG for aquatic insects in Latin America, and (3) provide general guidelines on how to assign organisms to their FFGs. FFGs are intended to reflect the potential effects of organisms in their ecosystems and the way they consume resources. Groups include scrapers that consume resources that grow attached to the substrate by removing them with their mouth parts; shredders that cut or chew pieces of living or dead plant material, including all plant parts like leaves and wood; collectors-gatherers that use modified mouth parts to sieve or collect small particles (

América Latina es una región bastante activa en cuanto a la investigación científica, en particular con respecto al estudio de macroinvertebrados de agua dulce. La presente es una introducción al número especial que incluye proyectos recientes en América Latina. Como parte de esta introducción, realizamos un análisis de la literatura publicada en los últimos 14 años, la cual tiene un aumento continuo en las publicaciones sobre macroinvertebrados. La mayoría de los estudios en el periodo 2000-2013 fueron realizados en Brasil, Colombia, Argentina, y Costa Rica; y se enfocaron en la taxonomía y temas relacionados con la biodiversidad y la distribución. Se observó una tendencia a publicar en revistas de bajo impacto, pero también se encontraron publicaciones de alto impacto. El número especial incluye 18 trabajos de ocho países. Los temas principales fueron ecología e historia natural de los macroinvertebrados acuáticos y su uso en la evaluación de impactos antropogénicos sobre los ecosistemas acuáticos. Usando la revisión y las publicaciones de este suplemento discutimos algunas necesidades de investigación para la región, principalmente: (1) continuar con los estudios taxonómicos, (2) determinar los mecanismos responsables por los cambios en biodiversidad, (3) evaluar el papel de los macroinvertebrados en los procesos ecológicos, (4) llevar los esfuerzos de biomonitoreo más allá de los métodos unimétricos, (5) implementar una visión de ecosistema, y (6) establecer estudios a largo plazo. Este suplemento representa un esfuerzo inicial para mejorar nuestro conocimiento sobre los macroinvertebrados de agua dulce de América Latina.

Para muchos arroyos, la hojarasca proveniente de la zona ribereña es la base de las redes tróficas, por lo cual el proceso de descomposición de la hojarasca es de gran importancia para el funcionamiento de estos ecosistemas. Con el fin de conocer los factores que afectan la descomposición de la hojarasca en arroyos del bosque mesófilo de montaña (BMM), se utilizaron paquetes de hojarasca durante 35 días. Seis arroyos con un gradiente de perturbación fueron estudiados en la época seca y lluviosa. Se determinó la relación entre la tasa de descomposición de la hojarasca (k), con algunos parámetros fisicoquímicos del cuerpo de agua y los macroinvertebrados colonizadores de los paquetes. Los factores fisicoquímicos mostraron una separación de los cuerpos de agua según la época a través de un Análisis de Componentes Principales (ACP). De los insectos colonizadores de los paquetes de hojarasca, el grupo funcional de los recolectores fue el más abundante, seguido por los fragmentadores. Solo se encontró una relación negativa entre la k y el porcentaje de cobertura boscosa (p=0.04) al realizar una regresión múltiple por pasos en la que se incluyeron algunos parámetros fisicoquímicos, el porcentaje de cobertura boscosa y las abundancias promedio de los insectos fragmentadores y no fragmentadores. La descomposición de la hojarasca en los arroyos estudiados parece ser un proceso estable a lo largo del año, aunque los factores responsables por la regulación pueden diferir en las distintas épocas.

La Isla del Coco es una isla oceánica localizada en el Pacífico Tropical Oriental a unos 492km de Cabo Blanco. La isla cuenta con un área terrestre de 24km² y un área marina protegida de 9 640km². Fue declarada Parque Nacional en 1978 y Patrimonio de la Humanidad por la UNESCO en 1997. Se realizó una gira de recolecta del 22 de mayo al 12 junio 2008. Se recolectaron macroinvertebrados acuáticos en 20 tramos de tres ríos (Genio, Chatham y Sucio) y dos quebradas (Minuto y quebrada sin nombre atrás de estación de guarda parques). En 13 sitios se toma- ron parámetros fisicoquímicos. En total se recolectaron 455 individuos de 20 táxones de 15 familias de insectos acuáticos y otros macroinvertebrados. La familia Staphylinidae presentó la mayor abundancia seguida por Chironomidae, los dípteros fueron el orden con mayor riqueza taxonómica. Una relación entre distancia y número de familias se observó apoyando en parte la Teoría de Biogeografía de Islas. La relación mejoró al corregir área con elevación, indicando que islas montañosas tenían alta riqueza, posiblemente debido a la mayor intercepción de nubes que alimentan los ambientes dulceacuícolas que favorecen el establecimiento de la fauna acuática. Las variables ambientales fueron similares en todos los sitios.

The taxonomic knowledge about immature stages of the insect order Odonata (dragonflies and damselflies) is rather limited in tropical America. Here, the larvae of Epigomphus jannyae Belle, 1993 and E. tumefactus Calvert, 1903 are described, figured, and compared with other described congeners. E. jannyae larva is characterized by 3rd antennomere 1.6 times longer than its widest part; ligula very poorly developed, with ten short, truncate teeth on middle; apical lobe of labial palp rounded and smooth. Lateral margins on abdominal segments (S5–9) serrated, lateral spines on S6–9 small and divergent; male epiproct with a pair of dorsal tubercles at basal 0.66; tips of cerci and paraprocts strongly divergent. The larva of E. tumefactus is characterized by 3rd antennomere 2.3 times longer than its widest part, ligula with 6–7 truncate teeth, apical lobe of labial palp acute and finely serrate. Lateral margins of S6–9 serrate, lateral spines on S7–9; male epiproct with a pair of dorsal tubercles at basal 0.50. Differences with other species were found in 3rd antennomere, lateral spines of S7–9, and the caudal appendages. Epigomphus larvae inhabit small, shallow creeks (1st order streams) where they live in fine benthic sediments. When mature, the larva leaves the water in shady places, climbing small rocks at the water’s edge and metamorphosing horizontally on flat rocks. These new descriptions bring the total number of Epigomphus species with known larval stages to eight; only 28% of the species in this genus are known as larva.

A través de una vasta obra periodística y a pesar de una corta existencia, Abraham Valdelomar establece las bases del periodismo narrativo moderno en el Perú, anticipándose, en más de un caso y por varias décadas, a muchos de los dictados y las normas impuestas por el llamado “nuevo periodismo” o New Journalism que fundaran en Estados Unidos grandes figuras como Truman Capote o Tom Wolfe. Valdelomar hizo de la crónica y el reportaje verdaderas obras de arte, en virtud de un estilo que acompañaba la paulatina modernización de Lima con una visión esteticista y cercana al decadentismo. Valdelomar contribuye de manera decisiva a eliminar fronteras entre la escritura periodística y la escritura de ficción, en especial a través de la crónica, género en el que alcanzó una inigualable maestría.

This paper highlights the importance of islands for proposing and testing hypotheses in stream ecology, and therefore, advocates for implementing reference studies in Gorgona Island (Colombian Pacific). It firstly summarizes past ecological studies in streams in Gorgona Island and outlines a series of papers resulting from a recent survey. These papers report that Gorgona Island exhibits a maritime climate, a tropical rainforest cover, and a basaltic and intrusive lithology, all typical features of islands elsewhere. They also describe that despite of the insular effect on stream biota, the proximity (< 50 km) of the island to the Pacific coast of Colombia facilitated dispersal of many faunal and floristic components from the continent, thus providing a unique opportunity for studying coastal streams in the Biogeographic Chocó. Finally, the status of Gorgona Island as a natural park established in 1984, and a relatively well known history of land uses, may further contribute to support search programs with long-term and large-scale goals.Este artículo resalta la importancia de las islas para proponer y someter a prueba hipótesis en ecología lótica y, por lo tanto, aboga por la implementación de estudios de referencia en la Isla Gorgona (Pacífico colombiano). Primero se resumen los estudios pasados realizados en las quebradas de la isla y se bosquejan los artículos que hacen parte de éste número especial, que son el resultado de una expedición reciente. Estos artículos informan que la Isla Gorgona posee un clima marítimo, una cobertura de bosque lluvioso tropical y una litología basáltica e intrusiva, características que también son típicas de otras islas. Ellos también describen que a pesar del ''efecto isla'' en la biota lótica, la proximidad (< 50 km) de la Isla a la costa Pacífica colombiana ha facilitado la dispersión de muchos componentes faunísticos y florísticos desde el continente, y por lo tanto provee una oportunidad única para estudiar las quebradas costeras en el Chocó Biogeográfico. Finalmente, la condición de parque natural establecido en 1984 y la relativamente bien conocida historia de usos pueden ayudar a apoyar programas de investigación con objetivos a largo plazo y gran escala.

Web-spinning spiders that inhabit stream channels are considered specialists of aquatic ecosystems and are major consumers of emerging aquatic insects, while other spider taxa are more commonly found in riparian forests and as a result may consume more terrestrial insects. To determine if there was a difference in spider taxa abundance between riverine web-spinning spider assemblages within the stream channel and the assemblages 10 m into the riparian forest, we compared abundances for all web-spinning spiders along a headwater stream in El Yunque National Forest in northeast Puerto Rico. By using a nonmetric dimensional scaling (NMDS) abundance analysis we were able to see a clear separation of the two spider assemblages. The second objective of the study was to determine if aquatic insects contributed more to the diet of the spider assemblages closest to the stream channel and therefore stable isotope analyses of δ15N and δ13C for web-spinning spiders along with their possible prey were utilized. The results of the Bayesian mixing model (SIAR) however showed little difference in the diets of riverine (0 m), riparian (10 m) and upland (25 m) spiders. We found that aquatic insects made up ∼50% of the diet for web-spinning spiders collected at 0 m, 10 m, and 25 m from the stream. This study highlights the importance of aquatic insects as a food source for web-spinning spiders despite the taxonomic differences in assemblages at different distances from the stream.

An updated list of the Odonata of Costa Rica is presented containing 268 species. Since the last published list for the country, 41 additional species have been reported. The country is the best studied in Central America. The most species-rich families are Libellulidae, Coenagrionidae, Gomphidae, and Aeshnidae, together comprising ~75% of the total fauna. Most species in the country are also found in South America, indicating a tendency for wide ranges rather than endemism. However, about a fifth of the species appear to be endemic to the Costa Rica-Panama region. Estimates of the range of the proportion of total world species occurring in Costa Rica lead to predictions of a range of 5600-9000 species of Odonata worldwide.Se presenta una lista actualizada de los Odonata de Costa Rica, la cual contiene 268 especies. A pesar de ello, se espera que algunas especies más se agreguen en el futuro. En comparación con trabajos anteriores, el número de especies para Costa Rica se incrementó en 41, siendo el país mejor estudiado de Centro América. Las familias con mayor diversidad de especies son: Libellulidae, Coenagrionidae, Gomphidae, y Aeshnidae, que en conjunto representan ~75% del total de la fauna de Odonata en Costa Rica. La mayoría de las especies del país también se encuentran en Sur América, lo que indica una inclinación hacia ámbitos de distribución amplios, mas que altos grados de endemismo. Sin embargo, el 18% de las especies es aparentemente endémico de Costa Rica y Panamá. Con base en los números aquí presentados, se esperaría que la fauna mundial de Odonata se encuentre dentro del ámbito de 5600 a 9000 especies.

Nos proponemos en este trabajo indagar qué ventajas puede suponer para la enseñanza de la gramática del español como lengua extranjera o segunda lengua la consideración de los recursos gramaticales desde los puntos de vista de la lingüística cognitiva por un lado y de la pragmática por otro. Plantearemos la descripción de unos cuantos casos bastante representativos de la gramática del español a la luz de la concepción cognitivo-funcionalista e intentaremos sacar conclusiones de cara a la práctica pedagógica centrada en la gramática, sobre todo en lo que se refiere a su presentación a estudiantes extranjeros.

Urban activities and related infrastructure alter the natural patterns of stream physical and chemical conditions. According to the Urban Stream Syndrome, streams draining urban landscapes are characterized by high concentrations of nutrients and ions, and might have elevated water temperatures and variable oxygen concentrations. Here, we report temporal and spatial variability in stream physicochemistry in a highly urbanized watershed in Puerto Rico. The main objective of the study was to describe stream physicochemical characteristics and relate them to urban intensity, e.g., percent impervious surface cover, and watershed infrastructure, e.g., road and pipe densities. The Río Piedras Watershed in the San Juan Metropolitan Area, Puerto Rico, is one of the most urbanized regions on the island. The Río Piedras presented high solute concentrations that were related to watershed factors, such as percent impervious cover. Temporal variability in ion concentrations lacked seasonality, as did all other parameters measured except water temperature, which was lower during winter and highest during summer, as expected based on latitude. Spatially, stream physicochemistry was strongly related to watershed percent impervious cover and also to the density of urban infrastructure, e.g., roads, pipe, and building densities. Although the watershed is serviced by a sewage collection system, illegal discharges and leaky infrastructure are probably responsible for the elevated ion concentration found. Overall, the Río Piedras is an example of the response of a tropical urban watershed after major sewage inputs are removed, thus highlighting the importance of proper infrastructure maintenance and management of runoff to control ion concentrations in tropical streams.

Abstract Background Oral anticoagulation prevents strokes in patients with atrial fibrillation but, for reasons that remain unclear, less than 40% of all patients with atrial fibrillation receive warfarin. The literature postulates that patient and clinician preferences may explain this low utilization. Design The proposed research seeks to answer the following questions: i) When assessed systematically, do patients' and clinicians' preferences explain the utilization of warfarin to prevent strokes associated with atrial fibrillation? ii) To what extent do patients' and clinicians' treatment preferences differ? iii) What factors explain any differences that exist in treatment preferences between patients and clinicians? To answer these questions we will conduct a two-phase study of patient and clinician preferences for health states and treatments. In the first phase of this study we will conduct structured interviews to determine their treatment preferences for warfarin vs. aspirin to prevent strokes associated with atrial fibrillation using the probability trade-off technique. In the same interview, we will conduct preference-elicitation exercises using the feeling thermometer to identify the utilities that patients place on taking medication (warfarin and aspirin), and on having a mild stroke, a severe stroke, and a major bleed. In the second phase of the study we will convene focus groups of clinicians and patients to explore their answers to the exercises in the first phase. Discussion This is a study of patient and clinician preferences for health states and treatments. Because of its clinical importance and our previous work in this area, we will conduct our study in the clinical context of the decision to use antithrombotic agents to reduce the risk of stroke in patients with non-valvular chronic atrial fibrillation

This study delves into the early development of Vieja fenestrata (Cichlidae), with a specific focus on the description of external morphological and morphometric changes, and growth patterns from hatching to the loss of larval characters under controlled laboratory conditions at a temperature of 28°C. Asynchronous hatching was observed between 58 and 60 h postfertilization, with the posterior body emerging first. Over 14 days, significant morphological, physiological, and behavioral changes were observed, revealing a complex developmental trajectory. The initial developmental phases were characterized by rapid vascularization, fin differentiation, and heightened activity, and the subsequent days witnessed the flexion of the notochord, emergence of swim bladder functionality, and transition to exogenous feeding. Maturation progressed with the absorption of the yolk sac, regression of cement glands, and fin ray development, culminating in metamorphosis by 14 days post-hatching. Throughout this period, evolving pigmentation patterns and structural adaptations highlight the species' adaptive strategies. During the larval period of V. fenestrata, substantial changes in morphological proportions were observed. Before the inflection, tail length, trunk length, and body depth had negative allometric growth, and head length, eye diameter, and snout length had positive allometric growth. After the inflection, body depth and snout length showed positive allometric growth; head length and trunk length exhibited isometric growth, whereas tail length and eye diameter demonstrated negative allometric growth. These findings contribute insights into the intricate developmental dynamics of V. fenestrata. Moreover, further research may explore these developmental dynamics' ecological and evolutionary implications., (© 2024 The Author(s). Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)

Light profoundly impacts many aspects of human physiology and behaviour, including the synchronization of the circadian clock, the production of melatonin, and cognition. These effects of light, termed the non-visual effects of light, have been primarily investigated in laboratory settings, where light intensity, spectrum and timing can be carefully controlled to draw associations with physiological outcomes of interest. Recently, the increasing availability of wearable light loggers has opened the possibility of studying personal light exposure in free-living conditions where people engage in activities of daily living, yielding findings associating aspects of light exposure and health outcomes, supporting the importance of adequate light exposure at appropriate times for human health. However, comprehensive protocols capturing environmental (e.g., geographical location, season, climate, photoperiod) and individual factors (e.g., culture, personal habits, behaviour, commute type, profession) contributing to the measured light exposure are currently lacking. Here, we present a protocol that combines smartphone-based experience sampling (experience sampling implementing Karolinska Sleepiness Scale, KSS ratings) and high-quality light exposure data collection at three body sites (near-corneal plane between the two eyes mounted on spectacle, neck-worn pendant/badge, and wrist-worn watch-like design) to capture daily factors related to individuals' light exposure. We will implement the protocol in an international multi-centre study to investigate the environmental and socio-cultural factors influencing light exposure patterns in Germany, Ghana, Netherlands, Spain, Sweden, and Turkey (minimum n = 15, target n = 30 per site, minimum n = 90, target n = 180 across all sites). With the resulting dataset, lifestyle and context-specific factors that contribute to healthy light exposure will be identified. This information is essential in designing effective public health interventions., Competing Interests: Declarations. Ethics approval: This research protocol was reviewed and approved by the Medical Ethics Committee of the Technical University of Munich (2023-115-S-KK). Competing interests: The authors declare no competing interests. Conflict of interest: The authors declare that the study will be conducted without any financial or commercial relationships that could be explained as a conflict of interest. Tables., (© 2024. The Author(s).)