Governance and the design of post-disaster policies: a comparative analysis from Latin America and the Caribbean.

Latin America and the Caribbean is one of the regions threatened most by natural events owing to the highly vulnerable circumstances of its urban centres. Consequently, its cities are occasionally affected by one or more disaster types, exposing problems of governance and public policy in relation to risk management. The aim of this research is to investigate the factors that influence the design of post-disaster policies. It hypothesises that in those countries with modes of governance characterised by greater articulation between State and non-State actors, the design of post-disaster policies tends to be more coherent. Methodologically, the study proposes a comparative analysis of post-disaster policies in three countries of the region affected by earthquakes: Haiti and Chile (in 2010) and Ecuador (in 2016). The findings show that co-governance in Chile resulted in optimal post-disaster policies, whereas hierarchical governance in the cases of Haiti and Ecuador led to unsuccessful and misdirected post-disaster policies, respectively.

Comparison of AOAC 2005.06 LC official method with other methodologies for the quantitation of paralytic shellfish poisoning toxins in UK shellfish species.

A refined version of the pre-column oxidation liquid chromatography with fluorescence detection (ox-LC-FLD) official method AOAC 2005.06 was developed in the UK and validated for the determination of paralytic shellfish poisoning toxins in UK shellfish. Analysis was undertaken here for the comparison of PSP toxicities determined using the LC method for a range of UK bivalve shellfish species against the official European reference method, the PSP mouse bioassay (MBA, AOAC 959.08). Comparative results indicated a good correlation in results for some species (mussels, cockles and clams) but a poor correlation for two species of oysters (Pacific oysters and native oysters), where the LC results in terms of total saxitoxin equivalents were found to be on average more than double the values determined by MBA. With the potential for either LC over-estimation or MBA under-estimation, additional oyster and mussel samples were analysed using MBA and ox-LC-FLD together with further analytical and functional methodologies: a post-column oxidation LC method (LC-ox-FLD), an electrophysiological assay and hydrophilic interaction liquid chromatography with tandem mass spectrometric detection. Results highlighted a good correlation among non-bioassay results, indicating a likely cause of difference was the under-estimation in the MBA, rather than an over-estimation in the LC results.

Socio-economic status, executive functions, and theory of mind ability in adolescents: Relationships with language ability and cortisol.

Socio-economic status (SES) is linked to the development of cognitive abilities, particularly language and executive processes. It is unclear whether these represent a single or independent correlates. We studied 110 Ecuadorian youths aged 12-17 with measures of SES, language, executive function, and theory of mind (ToM), a.k.a. mentalizing. A subsample gave hair samples to estimate recent cortisol levels. Restricting analyses to reliable measures, SES was highly associated with language skill, and to a lesser extent with executive function and ToM performance. However, those latter associations were attenuated and non-significant when language ability was controlled for statistically. Systemic cortisol levels were not associated with SES, but were significantly and negatively correlated with ToM, independent of variation in language skills. We conclude that language development underlies most of the impact of SES on executive function and ToM ability of adolescents, but that stress-related cortisol may have an independent, direct effect on mentalizing.

Contrasting physiological responses of two populations of the razor clam Tagelus dombeii with different histories of exposure to paralytic shellfish poisoning (PSP).

This study describes the physiological performance of two populations of the razor clam Tagelus dombeii from two geographic areas with different histories of exposure to paralytic shellfish poisoning (PSP) linked to the toxic dinoflagellate Alexandrium catenella. Clams from Melinka-Aysén, which are frequently exposed to PSP, were not affected by the presence of toxins in the diet. However, clams from Corral-Valdivia, which have never been exposed to PSP, exhibited significantly reduced filtration activity and absorption, affecting the energy allocated to scope for growth (SFG). Ammonia excretion and oxygen uptake were not affected significantly by the presence of A. catenella in the diet. Measurements of energy acquisition and expenditure were performed during a 12-day intoxication period. According to three-way repeated measure ANOVAs, the origin of the clams had a highly significant effect on all physiological variables, and the interaction between diet and origin was significant for the clearance and absorption rates and for the scope for growth. The scope for growth index showed similar positive values for both the toxic and non-toxic individuals from the Melinka-Aysén population. However, it was significantly reduced in individuals from Corral-Valdivia when exposed to the diet containing A. catenella. The absence of differences between the physiological response of the toxic and non-toxic clams from Melinka-Aysén may be related to the frequent presence of A. catenella in the environment, indicating that this bivalve does not suffer negative consequences from PSP. By contrast, A. catenella has a negative effect on the physiological performance, primarily on the energy gained from the environment, on T. dombeii from Corral-Valdivia. This study supports the hypothesis that the history of PSP exposure plays an important role in the physiological performance and fitness of filter feeding bivalves.

Investigations into matrix components affecting the performance of the official bioassay reference method for quantitation of paralytic shellfish poisoning toxins in oysters.

Significant differences previously observed in the determination of paralytic shellfish poisoning toxins (PSTs) in oysters using official method AOAC 2005.06 and 959.08 were investigated in detail with regard to possible matrix effects. Method AOAC 2005.06 gave results 2-3 times higher than the mouse bioassay method, 959.08, differences thought to be due to underestimation of PSTs by the mouse bioassay. In order to prove the cause of these large differences, work was conducted here to examine the presence and effects of matrix components on the performance of each of the two assays. A range of oyster, cockle and mussel samples were extracted using the AOAC 959.08 hydrochloric acid (HCl) extraction method and analysed for PSP by both MBA and LC-FLD. In addition, extracts were analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for metals as well as being subjected to a range of nutritional testing methods. Whilst there was no evidence for effect of nutritional components on either assay, ICP-MS analysis revealed a relationship between samples exhibiting the largest differences in relative method performance, specifically those with the largest LC-FLD/MBA toxicity ratio, and samples containing the highest concentrations of zinc and manganese. In order to prove the potential effect of the metals on either the LC-FLD and/or MBA assays, HCl extracts of a range of shellfish were subjected to a number of matrix modifications. Firstly, a number of PSP-positive oyster samples were processed to reduce the concentrations of metals within the extracts, without significantly reducing the concentrations of PSTs. Secondly, a range of mussel and cockle extracts, plus a standard solution of saxitoxin di-hydrochloride were spiked at variable concentrations of zinc. All treated and non-treated extracts, plus a number of controls were subjected to ICP-MS, LC-FLD and MBA testing. Results proved the absence of any effect of metals on the performance of the LC-FLD, whilst showing a large suppressive effect of the metals on the MBA. As such, the results show the performance of the official MBA is potentially unsafe for application to the routine monitoring of PSP toxicity in oysters or in any other shellfish found to contain high concentrations of metal ions.

A novel µ-conopeptide, CnIIIC, exerts potent and preferential inhibition of NaV1.2/1.4 channels and blocks neuronal nicotinic acetylcholine receptors.

BACKGROUND AND PURPOSE: The µ-conopeptide family is defined by its ability to block voltage-gated sodium channels (VGSCs), a property that can be used for the development of myorelaxants and analgesics. We characterized the pharmacology of a new µ-conopeptide (µ-CnIIIC) on a range of preparations and molecular targets to assess its potential as a myorelaxant. EXPERIMENTAL APPROACH: µ-CnIIIC was sequenced, synthesized and characterized by its direct block of elicited twitch tension in mouse skeletal muscle and action potentials in mouse sciatic and pike olfactory nerves. µ-CnIIIC was also studied on HEK-293 cells expressing various rodent VGSCs and also on voltage-gated potassium channels and nicotinic acetylcholine receptors (nAChRs) to assess cross-interactions. Nuclear magnetic resonance (NMR) experiments were carried out for structural data. KEY RESULTS: Synthetic µ-CnIIIC decreased twitch tension in mouse hemidiaphragms (IC(50) = 150 nM), and displayed a higher blocking effect in mouse extensor digitorum longus muscles (IC = 46 nM), compared with µ-SIIIA, µ-SmIIIA and µ-PIIIA. µ-CnIIIC blocked Na(V)1.4 (IC(50) = 1.3 nM) and Na(V)1.2 channels in a long-lasting manner. Cardiac Na(V)1.5 and DRG-specific Na(V)1.8 channels were not blocked at 1 µM. µ-CnIIIC also blocked the α3ß2 nAChR subtype (IC(50) = 450 nM) and, to a lesser extent, on the α7 and α4ß2 subtypes. Structure determination of µ-CnIIIC revealed some similarities to α-conotoxins acting on nAChRs. CONCLUSION AND IMPLICATIONS: µ-CnIIIC potently blocked VGSCs in skeletal muscle and nerve, and hence is applicable to myorelaxation. Its atypical pharmacological profile suggests some common structural features between VGSCs and nAChR channels.

Torsades de pointes: a propósito de un caso clínico / Torsades of pointes: with regard to a clinical case

Analiza que la taquicardia ventricular helicoidal (torsades de pointes) y los síndromes de "QT" largo son eventos clínicos que amenazan la vida, causados por varios agentes, condiciones y defectos genéticos, relacionados con alteraciones en la repolarización ventricular que conducen a incrementar la duración del potencial de acción transmembrana, traducidos eléctricamente por una mayor duración del intervalo QT, dados por una disminución de las corrientes de salida del potasio del miocito, que generan esta arritmia por actividad desencadenada (post-despolarizaciones). Se ha analizado un caso clínico en el que se verifica la presencia de un Síndrome "QT" largo congénito, agravado por el uso prolongado de medicación anthistamínica y que desarrolla una torsades de pointes, poniendo en riesgo su vida; paciente en el que además se asocia una Pre-excitación (Wolf Parkinson White) y una Disfunción simusal y, que luego del estudio electrofisiológico es implantado un MP definitivo, amén de terapia beta-bloqueadora; en el que también se realiza investigación genética personal y familiar y que hoy se encuentra en buen estado general. Este caso ha permitido realizar una revisión del estado actual de la patología y nos ha alertado a considerar el riesgo-beneficio en la prescripción medicamentosa. La mejor prevención está en intensificar la identificación, la investigación y el reporte cuidadoso de estos hechos clínicos, lo cual conducirá a un mejor entendimiento de este raro, pero riesgoso desorden del ritmo cardíaco.