Toward social-ecological coastal zone governance of Chiloé Island (Chile) based on the DPSIR framework.

Coastal zones are complex systems where sustainability needs local participative governance, whose absence may result in conflicts between social actors. In its absence, the first step should be a diagnosis of the current situation based on integrative conceptual frameworks such as the DPSIR. However, in conflicting situations, the generated model needs validation from social actors. Chiloé Island is a critical Chilean coastal fishery and aquaculture area, coexisting with subsistence and cultural uses of marine resources. This article analyzes the current ecological state of the Chiloé coastal zone and its main social-ecological impact using a DPSIR model. We validated its results through a household survey and interviews with local experts and social actors. Results show that increased coastal fisheries and aquaculture generate a critical decrease of coastal species, eutrophication, and pollution that, along with harmful algal blooms, generate conflicts. Social validation showed that experts and local social actors have different perceptions of conflicting parties and conflict solutions. Following a post-normal approach, we propose three ideas to start social-ecological governance of Chiloé coastal marine ecosystems.

Largest baleen whale mass mortality during strong El Niño event is likely related to harmful toxic algal bloom.

While large mass mortality events (MMEs) are well known for toothed whales, they have been rare in baleen whales due to their less gregarious behavior. Although in most cases the cause of mortality has not been conclusively identified, some baleen whale mortality events have been linked to bio-oceanographic conditions, such as harmful algal blooms (HABs). In Southern Chile, HABs can be triggered by the ocean-atmosphere phenomenon El Niño. The frequency of the strongest El Niño events is increasing due to climate change. In March 2015, by far the largest reported mass mortality of baleen whales took place in a gulf in Southern Chile. Here, we show that the synchronous death of at least 343, primarily sei whales can be attributed to HABs during a building El Niño. Although considered an oceanic species, the sei whales died while feeding near to shore in previously unknown large aggregations. This provides evidence of new feeding grounds for the species. The combination of older and newer remains of whales in the same area indicate that MMEs have occurred more than once in recent years. Large HABs and reports of marine mammal MMEs along the Northeast Pacific coast may indicate similar processes in both hemispheres. Increasing MMEs through HABs may become a serious concern in the conservation of endangered whale species.

The oceanic concordance of phylogeography and biogeography: a case study in Notochthamalus.

Dispersal and adaptation are the two primary mechanisms that set the range distributions for a population or species. As such, understanding how these mechanisms interact in marine organisms in particular - with capacity for long-range dispersal and a poor understanding of what selective environments species are responding to - can provide useful insights for the exploration of biogeographic patterns. Previously, the barnacle Notochthamalus scabrosus has revealed two evolutionarily distinct lineages with a joint distribution that suggests an association with one of the two major biogeographic boundaries (~30°S) along the coast of Chile. However, spatial and genomic sampling of this system has been limited until now. We hypothesized that given the strong oceanographic and environmental shifts associated with the other major biogeographic boundary (~42°S) for Chilean coastal invertebrates, the southern mitochondrial lineage would dominate or go to fixation in locations further to the south. We also evaluated nuclear polymorphism data from 130 single nucleotide polymorphisms to evaluate the concordance of the signal from the nuclear genome with that of the mitochondrial sample. Through the application of standard population genetic approaches along with a Lagrangian ocean connectivity model, we describe the codistribution of these lineages through a simultaneous evaluation of coastal lineage frequencies, an approximation of larval behavior, and current-driven dispersal. Our results show that this pattern could not persist without the two lineages having distinct environmental optima. We suggest that a more thorough integration of larval dynamics, explicit dispersal models, and near-shore environmental analysis can explain much of the coastal biogeography of Chile.

Una experiencia de intervención psicosocial en cultura positiva de seguridad en una empresa productiva chilena / An experience of psychosocial intervention in positive safety culture in a Chilean production company

La reducción de la accidentalidad y la búsqueda de conductas seguras en el trabajo suponen logros apreciados por las organizaciones hoy en día. Aquí se reporta una experiencia de intervención en una empresa productiva chilena desde el Modelo de Cultura Positiva hacia la Seguridad (MCPS), el cual entiende la cultura organizacional como compuesta por dos componentes principales: el clima de seguridad y el sistema de gestión de la seguridad y salud laboral. 435 trabajadores que participaron del proceso de intervención de11 meses fueron evaluados -antes y después de la intervención- en términos de su compromiso organizacional, satisfacción laboral y cultura positiva hacia la Seguridad (228 durante el pre-test y 207 durante el pos-test). Los resultados indican que la intervención tuvo efectos positivos para cada una de las variables aumentando la mayoría de sus puntuaciones en el pos-test. Asimismo, se observa una reducción en la etapa pos-intervención en cuanto a la frecuencia de accidentes registrados mensualmente en la empresa. Se analizan y contrastan estos resultados con la literatura sobre el tema.

The reduction in the accident and search for safe behavior at work involve achievements appreciated by organizations today. Here an experience of intervention in a Chilean productive enterprise is reported from the Model Positive Safety Culture at (MCPS), which means the organizational culture as composed of two main components: the climate of safety and safety management system and occupational health. 435 workers who participated in the 11 month intervention process were evaluated -before and after the intervention-in terms of their organizational commitment, job satisfaction and positive culture towards Safety (228 during the pre-test and 207 in the post-test). The results indicate that the intervention had positive effects for each of the variables increasing most of their scores on the posttest. Also, a reduction is observed in the post-intervention phase in the frequency of accidents recorded monthly in the company. We analyze and contrast these results with the literature on the subject.

Early MR diffusion and relaxation changes in the parahippocampal gyrus precede the onset of spontaneous seizures in an animal model of chronic limbic epilepsy.

Structural changes in limbic regions are often observed in individuals with temporal lobe epilepsy (TLE) and in animal models. However, the brain structural changes during the evolution into epilepsy remain largely unknown. Therefore, the purpose of this study was to define the temporal changes in limbic structures after experimental status epilepticus (SE) during the latency period of epileptogenesis in vivo, with quantitative diffusion tensor imaging (DTI) and T2 relaxometry in an animal model of chronic TLE. A pair of fifty micron electrodes was implanted into the ventral hippocampus in twelve male adult rats. Self-sustaining SE was induced with electrical stimulation in eleven rats. Three rats served as age-matched controls. In vivo diffusion tensor and T2 magnetic resonance imaging (MRI) was performed at 11.1 Tesla, pre- and post-implantation of electrodes and 3, 5, 7, 10, 20, 40 and 60 days post-SE to assess structural changes. Spontaneous seizures were identified with continuous time-locked video-monitoring. Following imaging in vivo, fixed, excised brains were MR imaged at 17.6 Tesla. Subsequently, histological analysis was correlated with MRI results. Following SE, 8/11 injured rats developed spontaneous seizures. Unique to these 8 rats, early T2, diffusivity and anisotropy changes were observed in vivo within the parahippocampal gyrus (contralateral) and fimbria (bilateral). In excised brains, bilateral increase in anisotropy was observed in the dentate gyrus, corresponding to mossy fiber sprouting as determined by Timm staining. Using T2 relaxometry and DTI, specific transient and long-term structural changes were observed only in rats that developed spontaneous limbic seizures.

Circadian control of neural excitability in an animal model of temporal lobe epilepsy.

We provide experimental evidence for the emerging imbalance in the firing activity of two distinct classes (type 1 and type 2) of population spikes recorded from the hippocampal area CA1 in an animal model of temporal lobe epilepsy. We show that during the latent period of epileptogenesis following status epilepticus inducing brain injury, there is a sustained increase in the firing rate of type 1 population spikes (PS1) with a concurrent decrease in the firing rate of type 2 population spikes (PS2). Both PS1 and PS2 firing rates are observed to follow a circadian rhythm and are in-phase in control rats. Following brain injury there is an abrupt phase shift in the circadian activity of the PS firing rates. We hypothesize that this abrupt phase shift is the underlying cause for the emergence of imbalance in the firing activity of the two PS. We test our hypothesis in the framework of a simple two-dimensional Wilson-Cowan model that describes the interaction between firing activities of populations of excitatory and inhibitory neurons.

Quantitative assessment of macromolecular concentration during direct infusion into an agarose hydrogel phantom using contrast-enhanced MRI.

Convection-enhanced delivery (CED), that is, direct tissue infusion, has emerged as a promising local drug delivery method for treating diseases of the nervous system. Determination of the spatial distribution of therapeutic agents after infusion is important in evaluating the efficacy of treatment, optimizing infusion protocols and improving the understanding of drug pharmacokinetics. In this study, we provide a methodology to determine the concentration distribution of Gd-labeled tracers during infusion using contrast-enhanced magnetic resonance imaging (MRI). To the best of our knowledge, MR studies that quantify concentration profiles for CED have not been previously reported. The methodology utilizes intrinsic material properties (T(1) and R(1)) and reduces the effect of instrumental factors (e.g., inhomogeneity of MR detection field). As a methodology investigation, this study used an agarose hydrogel phantom as a tissue substitute for infusion. An 11.1-T magnet system was used to image infusion of Gd-DTPA-labeled albumin (Gd-albumin) into the hydrogel. By using data from preliminary scans, Gd-albumin distribution was determined from the signal intensity of the MR images. As a validation test, MR-derived concentration profiles were found comparable to both results measured directly using quantitative optical imaging and results from a computational transport model in porous media. In future studies, the developed methodology will be used to quantitatively monitor the distribution of Gd tracer following infusion directly into tissues.