Construction and validation of an Entrepreneurship Measurement Instrument for nursing students / Construcción y validación de un Instrumento de Medición Emprendedora para estudiantes de enfermería / Construção e validação de Instrumento de Medição Empreendedora para estudantes de enfermagem

Objective. To develop a valid and reliable scale to measure entrepreneurship competences of nursing students, by assessing the level of development of diverse entrepreneurship dimensions. Methods. An Entrepreneurship Measurement Instrument, Catalonia (IME.Cat) was constructed, by adapting two existing instruments, and a psychometric study was performed to address the validity of the content and the construct, and the reliability. The internal consistency and the discrimination capacity of the instrument's items were examined. Results. The IME.Cat scale showed a high reliability (α=0.89) for the complete set of items. The Cronbach's α value of the individual dimensions were: Problem management=0.78; Creativity=0.76; Personal confidence =0.64; and Risk acceptance =0.46. The corrected homogeneity indices for each of the item in the instrument were high (>0.40). The Confirmatory Factorial Analysis validated the proposed structure of the items according to dimension. Conclusion. The IME.Cat scale showed solid psychometric values for assessing the entrepreneurship competences of nursing students within its dimensions, which are fundamental for the professional development of nursing.

Objetivo. Desarrollar una escala válida y fiable para medir competencias emprendedoras para estudiantes de enfermería, evaluando el nivel de desarrollo en diversas dimensiones del emprendimiento. Métodos. Se construyó el Instrumento de Medición Emprendedora Cataluña (IME.Cat) adaptando dos instrumentos existentes y se llevó a cabo un estudio psicométrico que abordó la validez de contenido, de constructo y la fiabilidad. Se examinaron la consistencia interna y la capacidad de discriminación de los ítems del instrumento. Resultados. La escala IME.Cat mostró una alta fiabilidad (α=0.89) para el conjunto completo de 25 ítems. Los valores del α de Cronbach de las dimensiones individuales fueron: Manejo de problemas=0.78; Creatividad=0.76; Seguridad personal=0.64; y Aceptación del riesgo=0.46. Los índices de homogeneidad corregidos para cada ítem del instrumento fueron elevados (>0.40). El Análisis Factorial Confirmatorio validó la estructura propuesta de ítems por dimensión. Conclusión. La escala IME.Cat mostró valores psicométricos sólidos para evaluar competencias emprendedoras en estudiantes de enfermería en sus dimensiones, las cuales son fundamentales en el desarrollo profesional de la enfermería.

Objetivo. Desenvolver uma escala válida e confiável para medir as competências empreendedoras dos alunos de enfermagem, avaliando o nível de desenvolvimento em várias dimensões do empreendedorismo. Métodos. O Instrumento de Medição de Empreendedorismo da Catalunha (IME.Cat) foi construído com a adaptação de dois instrumentos existentes, e um estudo psicométrico foi realizado para abordar a validade de conteúdo, a validade de construção e a confiabilidade. A consistência interna e a capacidade discriminatória dos itens do instrumento foram examinadas. Resultados. A escala IME.cat apresentou alta confiabilidade (α=0.89) para o conjunto completo de 25 itens. Os valores de α de Cronbach para as dimensões individuais foram: Tratamento de problemas=0.78; Criatividade=0.76; Segurança pessoal=0.64; e Aceitação de riscos=0.46. Os índices de homogeneidade corrigidos para cada item do instrumento foram altos (>0.40). A análise fatorial confirmatória validou a estrutura de itens proposta por dimensão. Conclusões. A escala IME.Cat apresentou bons valores psicométricos para avaliar as competências empreendedoras dos estudantes de enfermagem em suas dimensões, que são fundamentais para o desenvolvimento profissional da enfermagem.

A Review of the Applicability of Current Green Practices in Healthcare Facilities.

BACKGROUND: Circular economy (CE) has raised great interest as a concept and as a development model worldwide. This concept aims to provide a substitute for the linear economic model, which was based on production and consumption, continuous growth, and resources depletion. CE allows a greener economy with sustainable development and promotes more balanced societies. The healthcare sector is a major contributor to the climate crisis, with a carbon footprint representing 4.4% of global net emissions. It is thus essential to rethink the applicability of CE in healthcare. METHODS: We conducted a scoping review guided by the Arksey and O'Malley methodological framework and utilised PRISMA-ScR (Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews) checklist. A systematic search from MEDLINE complete, SCOPUS, and Web of Science databases published between 1992 and 2022. RESULTS: Through database searching a total of 1018 records were identified and 475 duplicates were removed. From the total search, 543 articles were screened by title/abstract according to the inclusion and exclusion criteria. After screening, 38 full-text articles were selected and assessed for eligibility. Forty-seven additional records were also identified through other sources and screened for eligibility. Other sources included: 12 articles from snowballing of previous papers; 9 articles following peer-reviewers suggestions; 19 reports from relevant organisations in CE and healthcare; two webpage, and one book. CONCLUSION: Specific areas were identified where hospitals could reduce their greenhouse gas (GHG) emissions and consequently their negative environmental impact, namely through waste management, energy, water, transportation/travel, hospital design, food optimisation, green procurement, and behaviour. Also, lack of staff awareness and knowledge of the environmental impact of healthcare, and hospitals sustainability were identified as major contributors.

Probing different paradigms of morphine withdrawal on sleep behavior in male and female C57BL/6J mice.

Opioid misuse has dramatically increased over the last few decades resulting in many people suffering from opioid use disorder (OUD). The prevalence of opioid overdose has been driven by the development of new synthetic opioids, increased availability of prescription opioids, and more recently, the COVID-19 pandemic. Coinciding with increases in exposure to opioids, the United States has also observed increases in multiple Narcan (naloxone) administrations as a life-saving measures for respiratory depression, and, thus, consequently, naloxone-precipitated withdrawal. Sleep dysregulation is a main symptom of OUD and opioid withdrawal syndrome, and therefore, should be a key facet of animal models of OUD. Here we examine the effect of precipitated and spontaneous morphine withdrawal on sleep behaviors in C57BL/6 J mice. We find that morphine administration and withdrawal dysregulate sleep, but not equally across morphine exposure paradigms. Furthermore, many environmental triggers promote relapse to drug-seeking/taking behavior, and the stress of disrupted sleep may fall into that category. We find that sleep deprivation dysregulates sleep in mice that had previous opioid withdrawal experience. Our data suggest that the 3-day precipitated withdrawal paradigm has the most profound effects on opioid-induced sleep dysregulation and further validates the construct of this model for opioid dependence and OUD.

GliaMorph: a modular image analysis toolkit to quantify Müller glial cell morphology.

Cell morphology is crucial for all cell functions. This is particularly true for glial cells as they rely on complex shape to contact and support neurons. However, methods to quantify complex glial cell shape accurately and reproducibly are lacking. To address this, we developed the image analysis pipeline 'GliaMorph'. GliaMorph is a modular analysis toolkit developed to perform (1) image pre-processing, (2) semi-automatic region-of-interest selection, (3) apicobasal texture analysis, (4) glia segmentation, and (5) cell feature quantification. Müller glia (MG) have a stereotypic shape linked to their maturation and physiological status. Here, we characterized MG on three levels: (1) global image-level, (2) apicobasal texture, and (3) regional apicobasal vertical-to-horizontal alignment. Using GliaMorph, we quantified MG development on a global and single-cell level, showing increased feature elaboration and subcellular morphological rearrangement in the zebrafish retina. As proof of principle, we analysed expression changes in a mouse glaucoma model, identifying subcellular protein localization changes in MG. Together, these data demonstrate that GliaMorph enables an in-depth understanding of MG morphology in the developing and diseased retina.

Probing different paradigms of morphine withdrawal on sleep behavior in male and female C57BL/6J mice.

Opioid misuse has dramatically increased over the last few decades resulting in many people suffering from opioid use disorder (OUD). The prevalence of opioid overdose has been driven by the development of new synthetic opioids, increased availability of prescription opioids, and more recently, the COVID-19 pandemic. Coinciding with increases in exposure to opioids, the United States has also observed increases in multiple Narcan (naloxone) administrations as life-saving measures for respiratory depression, and, thus, consequently, naloxone-precipitated withdrawal. Sleep dysregulation is a main symptom of OUD and opioid withdrawal syndrome, and therefore, should be a key facet of animal models of OUD. Here we examine the effect of precipitated and spontaneous morphine withdrawal on sleep behaviors in C57BL/6J mice. We find that morphine administration and withdrawal dysregulate sleep, but not equally across morphine exposure paradigms. Furthermore, many environmental triggers promote relapse to drug-seeking/taking behavior, and the stress of disrupted sleep may fall into that category. We find that sleep deprivation dysregulates sleep in mice that had previous opioid withdrawal experience. Our data suggest that the 3-day precipitated withdrawal paradigm has the most profound effects on opioid-induced sleep dysregulation and further validates the construct of this model for opioid dependence and OUD. Highlights: Morphine withdrawal differentially dysregulates the sleep of male and female mice3-day precipitated withdrawal results in larger changes than spontaneous withdrawalOpioid withdrawal affects responses to future sleep deprivation differently between sexes.

Without fear of change: the flipped classroom as a flexible model in different learning environments.

The study presented is the result of a research study conducted within a historical moment which led to the pandemic in 2020, and the unexpected situation experienced by university professors of transforming their face-to-face teaching to a virtual model. The resulting situation of confinement was utilized to explore how professors in Spain who implemented the Flipped Classroom (FC) model adapted to the change. The main goal was to verify if the FC model facilitated the transition from face-to-face to virtual teaching of university courses. A quantitative, non-experimental and descriptive approach was considered as the most adequate to reach the objective proposed, with the use of an ad-hoc Likert-type questionnaire. A total of 130 individuals completed the questionnaire, of which 48.5% were men and 51.5% women. The results showed that professors had to make very few changes to their courses. The female professors, and those who had less teaching experience with the FC model, mentioned having to make more modifications. Our findings show that the FC model facilitated the transition from a face-to-face university teaching model to a virtual one.

Taking a deep breath: How a brainstem pathway integrates pain and breathing.

In this issue of Neuron, Liu et al. (2022) shed light on the neural circuits supporting pain- and anxiety-induced elevated breathing rhythms. They reveal PBL core-Oprm1 neurons projecting onto the CeA and shell-Oprm1 neurons projecting onto the preBötC as differential regulators of these behaviors.

First record of the spatial organization of the nucleosome-less chromatin of dinoflagellates: The nonrandom distribution of microsatellites and bipolar arrangement of telomeres in the nucleus of Gambierdiscus australes (Dinophyceae).

Dinoflagellates are a group of protists whose exceptionally large genome is organized in permanently condensed nucleosome-less chromosomes. In this study, we examined the potential role of repetitive DNAs in both the structure of dinoflagellate chromosomes and the architecture of the dinoflagellate nucleus. Non-denaturing fluorescent in situ hybridization (ND-FSH) was used to determine the abundance and physical distribution of telomeric DNA and 16 microsatellites (1- to 4-bp repeats) in the nucleus of Gambierdiscus australes. The results showed an increased relative abundance of the different microsatellite motifs with increasing GC content. Two ND-FISH probes, (A)20 and (AAT)5 , did not yield signals whereas the remainder revealed a dispersed but nonrandom distribution of the microsatellites, mostly in clusters. The bean-shaped interphase nucleus of G. australes contained a region with a high density of trinucleotides. This nuclear compartment was located between the nucleolar organizer region (NOR), located on the concave side of the nucleus, and the convex side. Telomeric DNA was grouped in multiple foci and distributed in two polarized compartments: one associated with the NOR and the other peripherally located along the convex side of the nucleus. Changes in the position of the telomeres during cell division evidenced their dynamic distribution and thus that of the chromosomes during dinomitosis. These insights into the spatial organization of microsatellites and telomeres and thus into the nuclear architecture of G. australes will open up new lines of research into the structure and function of the nucleosome-less chromatin of dinoflagellates.

Combination therapy with topical alprostadil and phosphodiesterase-5 inhibitors after failure of oral therapy in patients with erectile dysfunction: a prospective, two-arm, open-label, non-randomized study.

Phosphodiesterase type 5 inhibitors (PDE5Is) are the first-line therapeutic option for erectile dysfunction (ED), while second-line therapy includes the alprostadil. Due to the different pharmacodynamic mechanism of PDE5Is and alprostadil, a synergistic action is conceivable when they are administered in combination. The aim of present study was to evaluate the efficacy and safety of combination therapy with PDE5I and topical alprostadil in patients with ED non-responders to PDE5I alone. We designed a prospective, two-arm, open-label, non-randomized study. Patients over 18 years old, with a stable sexual relationship for at least 6 months, and ED non-responders to PDE5I monotherapy were included in the study. At baseline the variables assessed were 5-item version of the International Index of Erectile Function (IIEF-5), and Sexual Encounter Profile Questions 2 and 3 (SEP-2 and SEP-3). In addition, all subjects underwent penile dynamic duplex ultrasonography. All patients were assigned to the monotherapy group (Group A) or combination therapy group (Group B) based on their preference. Topical alprostadil 300 µg/100 mg (Virirec®) was the treatment assigned to Group A, while the combination therapy with the last PDE5I taken (at the maximum recommended dose) plus topical alprostadil 300 µg/100 mg (Virirec®) was assigned to Group B. After 3 months from assignment to groups were evaluated IIEF-5, SEP-2 and SEP-3 regarding the last sexual intercourse, and Global Assessment Questionnaire-Questions 1 and 2 (GAQ-1 and GAQ-2). All adverse events (AEs) that occurred during the study period were recorded. A total of 170 patients were included in the study (72 in Group A and 98 in Group B). Fifty-two patients were previously treated with sildenafil 100 mg (30.6%), 6 with vardenafil 20 mg (3.5%), 56 with tadalafil 20 mg (32.9%), and 56 with avanafil 200 mg (32.9%). No significant differences among the study groups were found at baseline (p > 0.05). The mean IIEF-5 score increased significantly in Group B after treatment compared to baseline (12.4 ± 3.4 vs. 17.1 ± 4.5; p < 0.001), conversely patients in Group A showed no significant increase (12.2 ± 2.5 vs. 12.7 ± 3.1; p = 0.148). The number of affirmative responses to SEP-2 was significantly higher after treatment compared to baseline only in Group B (57 vs. 78; p < 0.001). The number of affirmative responses to SEP-3 was significantly higher after treatment compared to baseline in both groups (p < 0.001). The number of affirmative responses to GAQ-Q1 and GAQ-Q2 was significantly higher in Group B compared to Group A (p < 0.001). A total of 59 (34.7%) patients experienced AEs. They were mild, self-limited, and did not cause discontinuation of treatment. No episode of priapism was recorded. No statistically significant difference was recorded between the AEs of the two groups, except for facial flushing that was reported only in Group B (p = 0.021). The combination therapy with topical alprostadil and PDE5I seems to be more effective than topical alprostadil alone without worsening the safety of the treatment.

Temperature-dependent growth and sexuality of the ciguatoxin producer dinoflagellate Gambierdiscus spp. in cultures established from the Canary Islands.

Benthic dinoflagellates of the genus Gambierdiscus produce ciguatoxins, compounds that when metabolized in fish and consumed by humans cause ciguatera poisoning (CP). This syndrome, which is widespread in tropical and subtropical regions, has recently been reported also in subtropical-temperate latitudes such as the Canary Islands where CP events have been regularly detected since 2004. This study examined the effect of temperature on the growth of Gambierdiscus isolated from Canary waters: G. australes, G. caribaeus, G. carolinianus, G. excentricus, and G. silvae. From the temperature vs. growth curves, the maximum growth (µm), optimum temperature range for growth (Topt), and the temperature yielding maximum growth (Tm) were estimated for each species. The results revealed temperature-dependent differences in the growth parameters. G. caribaeus had the highest Tm and Topt, followed by G. australes, G. carolinianus, G. silvae, and G excentricus. G. australes tolerated the widest range of temperatures (from 15 °C to 29 °C), which may explain its broader geographic distribution, both worldwide and across the Canary archipelago. Neither G. excentricus nor G. silvae survived at 29 °C whereas G. caribaeus reached mean growth rates (± standard deviation) up to 0.19 ± 0.01 div.day-1 at that temperature, followed by G. australes (0.16 ± 0.01 div.day-1) and G. carolinianus (0.14 ± 0.04 div.day-1). G. caribaeus showed no measurable growth at 19°C, whereas G. excentricus and G. silvae along with G. australes appeared as the species better adapted to lower temperatures. In an intraspecific variability study of 12 strains of G. australes, the mean (± standard deviation) of µm and Tm were 0.17 ± 0.01 div.day-1 and 27.7 ± 0.5 °C, respectively. An analysis of the shapes and position of the cell nuclei at the different temperatures showed that nuclei characteristic of vegetative cells appeared mainly at 26 °C but extreme temperatures resulted in nuclei with a more variable morphology. The presence of putative zygotes at extreme temperatures (17 °C, 19 °C and 29 °C) suggests that sexual reproduction is promoted as an adaptive strategy which could play an important role in the expansion of geographic distribution of Gambierdiscus species.

Paralytic and Amnesic Shellfish Toxins Impacts on Seabirds, Analyses and Management.

Marine biotoxins have been frequently implicated in morbidity and mortality events in numerous species of birds worldwide. Nevertheless, their effects on seabirds have often been overlooked and the associated ecological impact has not been extensively studied. On top of that, the number of published studies confirming by analyses the presence of marine biotoxins from harmful algal blooms (HABs) in seabirds, although having increased in recent years, is still quite low. This review compiles information on studies evidencing the impact of HAB toxins on marine birds, with a special focus on the effects of paralytic and amnesic shellfish toxins (PSTs and ASTs). It is mainly centered on studies in which the presence of PSTs and/or ASTs in seabird samples was demonstrated through analyses. The analytical techniques commonly employed, the tissues selected and the adjustments done in protocols for processing seabird matrixes are summarized. Other topics covered include the role of different vectors in the seabird intoxications, information on clinical signs in birds affected by PSTs and ASTs, and multifactorial causes which could aggravate the syndromes. Close collaboration between seabird experts and marine biotoxins researchers is needed to identify and report the potential involvement of HABs and their toxins in the mortality events. Future studies on the PSTs and ASTs pharmacodynamics, together with the establishment of lethal doses in various seabird species, are also necessary. These studies would aid in the selection of the target organs for toxins analyses and in the postmortem intoxication diagnoses.

Photoactivatable metabolic warheads enable precise and safe ablation of target cells in vivo.

Photoactivatable molecules enable ablation of malignant cells under the control of light, yet current agents can be ineffective at early stages of disease when target cells are similar to healthy surrounding tissues. In this work, we describe a chemical platform based on amino-substituted benzoselenadiazoles to build photoactivatable probes that mimic native metabolites as indicators of disease onset and progression. Through a series of synthetic derivatives, we have identified the key chemical groups in the benzoselenadiazole scaffold responsible for its photodynamic activity, and subsequently designed photosensitive metabolic warheads to target cells associated with various diseases, including bacterial infections and cancer. We demonstrate that versatile benzoselenadiazole metabolites can selectively kill pathogenic cells - but not healthy cells - with high precision after exposure to non-toxic visible light, reducing any potential side effects in vivo. This chemical platform provides powerful tools to exploit cellular metabolic signatures for safer therapeutic and surgical approaches.

JmjC-KDMs KDM3A and KDM6B modulate radioresistance under hypoxic conditions in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC), the most frequent esophageal cancer (EC) subtype, entails dismal prognosis. Hypoxia, a common feature of advanced ESCC, is involved in resistance to radiotherapy (RT). RT response in hypoxia might be modulated through epigenetic mechanisms, constituting novel targets to improve patient outcome. Post-translational methylation in histone can be partially modulated by histone lysine demethylases (KDMs), which specifically removes methyl groups in certain lysine residues. KDMs deregulation was associated with tumor aggressiveness and therapy failure. Thus, we sought to unveil the role of Jumonji C domain histone lysine demethylases (JmjC-KDMs) in ESCC radioresistance acquisition. The effectiveness of RT upon ESCC cells under hypoxic conditions was assessed by colony formation assay. KDM3A/KDM6B expression, and respective H3K9me2 and H3K27me3 target marks, were evaluated by RT-qPCR, Western blot, and immunofluorescence. Effect of JmjC-KDM inhibitor IOX1, as well as KDM3A knockdown, in in vitro functional cell behavior and RT response was assessed in ESCC under hypoxic conditions. In vivo effect of combined IOX1 and ionizing radiation treatment was evaluated in ESCC cells using CAM assay. KDM3A, KDM6B, HIF-1α, and CAIX immunoexpression was assessed in primary ESCC and normal esophagus. Herein, we found that hypoxia promoted ESCC radioresistance through increased KDM3A/KDM6B expression, enhancing cell survival and migration and decreasing DNA damage and apoptosis, in vitro. Exposure to IOX1 reverted these features, increasing ESCC radiosensitivity and decreasing ESCC microtumors size, in vivo. KDM3A was upregulated in ESCC tissues compared to the normal esophagus, associating and colocalizing with hypoxic markers (HIF-1α and CAIX). Therefore, KDM3A upregulation in ESCC cell lines and primary tumors associated with hypoxia, playing a critical role in EC aggressiveness and radioresistance. KDM3A targeting, concomitant with conventional RT, constitutes a promising strategy to improve ESCC patients' survival.

The 5S rRNA genes in Alexandrium: their use as a FISH chromosomal marker in studies of the diversity, cell cycle and sexuality of dinoflagellates.

Chromosomal markers of the diversity and evolution of dinoflagellates are scarce because the genomes of these organisms are unique among eukaryotes in terms of their base composition and chromosomal structure. Similarly, a lack of appropriate tools has hindered studies of the chromosomal localization of 5S ribosomal DNA (rDNA) in the nucleosome-less chromosomes of dinoflagellates. In this study, we isolated and cloned 5S rDNA sequences from various toxin-producing species of the genus Alexandrium and developed a fluorescence in situ hybridization (FISH) probe that allows their chromosomal localization. Our results can be summarized as follows: 1) The 5S rDNA unit is composed of a highly conserved 122-bp coding region and an intergenic spacer (IGS), the length and sequence of which are variable even within strains. 2) Three different IGS types, one containing the U6 small nuclear RNA (snRNA) gene, were found among four of the studied species (A. minutum, A. tamarense, A. catenella and A. pacificum). 3) In all strains investigated by FISH (A. minutum, A. tamarense, A. pacificum, A. catenella, A. andersonii and A. ostenfeldii), 5S rDNA gene arrays were separate from the nucleolar organizer region, which contains the genes for the large 45S pre-ribosomal RNA. 4) One to three 5S rDNA sites per haploid genome were detected, depending on the strains/species. Intraspecific variability in the number of 5S rDNA sites was determined among strains of A. minutum and A. pacificum. 5) 5S rDNA is a useful chromosomal marker of mitosis progression and can be employed to differentiate vegetative (haploid) vs. planozygotes (diploid) cells. Thus, the FISH probe (oligo-Dino5Smix5) developed in this study facilitates analyses of the diversity, cell cycle and life stages of the genus Alexandrium.

Morphological and phylogenetic data do not support the split of Alexandrium into four genera.

A recently published study analyzed the phylogenetic relationship between the genera Centrodinium and Alexandrium, confirming an earlier publication showing the genus Alexandrium as paraphyletic. This most recent manuscript retained the genus Alexandrium, introduced a new genus Episemicolon, resurrected two genera, Gessnerium and Protogonyaulax, and stated that: "The polyphyly [sic] of Alexandrium is solved with the split into four genera". However, these reintroduced taxa were not based on monophyletic groups. Therefore this work, if accepted, would result in replacing a single paraphyletic taxon with several non-monophyletic ones. The morphological data presented for genus characterization also do not convincingly support taxa delimitations. The combination of weak molecular phylogenetics and the lack of diagnostic traits (i.e., autapomorphies) render the applicability of the concept of limited use. The proposal to split the genus Alexandrium on the basis of our current knowledge is rejected herein. The aim here is not to present an alternative analysis and revision, but to maintain Alexandrium. A better constructed and more phylogenetically accurate revision can and should wait until more complete evidence becomes available and there is a strong reason to revise the genus Alexandrium. The reasons are explained in detail by a review of the available molecular and morphological data for species of the genera Alexandrium and Centrodinium. In addition, cyst morphology and chemotaxonomy are discussed, and the need for integrative taxonomy is highlighted.

Alexandrium catenella cyst accumulation by passive and active dispersal agents: Implications for the potential spreading risk in Chilean Patagonian fjords.

The dinoflagellate Alexandrium catenella is responsible for paralytic shellfish poisoning and negative socioeconomic impacts on the fishing industry and aquaculture. In Chilean Patagonia, the reasons underlying the significant increase in the geographical extension (from south to north) of A. catenella blooms during the last five decades are not well understood. To assess the potential spreading risk of A. catenella during an intense austral summer bloom, we conducted an in situ experiment in a "hotspot" of this dinoflagellate in southern Chile. The objective was to assess the accumulation of A. catenella resting cysts in passive (fishing nets) and active (mussels) dispersal agents during the phase of bloom decline. Large numbers of resting cysts were detected in fishing nets (maximum of 5334 cysts net-1 per month) at 5 m depth and in mussels (maximum of 16 cysts g-1 of digestive gland) near Vergara Island. The potential of these vectors to serve as inoculum sources and the implications of our findings for A. catenella population dynamics are discussed.

Toxicity Characterisation of Gambierdiscus Species from the Canary Islands.

In the last decade, several outbreaks of ciguatera fish poisoning (CFP) have been reported in the Canary Islands (central northeast Atlantic Ocean), confirming ciguatera as an emerging alimentary risk in this region. Five Gambierdiscus species, G. australes, G. excentricus, G. silvae, G. carolinianus and G. caribaeus, have been detected in macrophytes from this area and are known to produce the ciguatoxins (CTXs) that cause CFP. A characterization of the toxicity of these species is the first step in identifying locations in the Canary Islands at risk of CFP. Therefore, in this study the toxicity of 63 strains of these five Gambierdiscus species were analysed using the erythrocyte lysis assay to evaluate their maitotoxin (MTX) content. In addition, 20 of the strains were also analysed in a neuroblastoma Neuro-2a (N2a) cytotoxicity assay to determine their CTX-like toxicity. The results allowed the different species to be grouped according to their ratios of CTX-like and MTX-like toxicity. MTX-like toxicity was especially high in G. excentricus and G. australes but much lower in the other species and lowest in G. silvae. CTX-like toxicity was highest in G. excentricus, which produced the toxin in amounts ranging between 128.2 ± 25.68 and 510.6 ± 134.2 fg CTX1B equivalents (eq) cell-1 (mean ± SD). In the other species, CTX concentrations were as follows: G. carolinianus (100.84 ± 18.05 fg CTX1B eq cell-1), G. australes (31.1 ± 0.56 to 107.16 ± 21.88 fg CTX1B eq cell-1), G. silvae (12.19 ± 0.62 to 76.79 ± 4.97 fg CTX1B eq cell-1) and G. caribaeus (