Ciguatera Poisoning (CP) is the most prevalent, phycotoxin related seafood poisoning across the globe, affecting between 10,000 and 50,000 people annually. This illness results from the consumption ...of seafood contaminated with lipid soluble toxins known as ciguatoxins (CTXs) that are produced by benthic dinoflagellates in the genera Gambierdiscus and Fukuyoa. The present work reviews the global occurrence of CP events and outbreaks, based on both scientific and gray literature.
Ciguatera prevalence is significantly underestimated due to a lack of recognition of ciguatera symptoms, limited collection of epidemiological data on a global level, and reticence to report ciguatera in CP-endemic regions. Analysis of the time-series data available for a limited number of countries indicates the highest incidence rates are consistently reported from two historical CP-endemic areas i.e., the Pacific and Caribbean regions, a situation due in part to the strong reliance of local communities on marine resources. Ciguatera-related fatalities are rare (<0.1% of reported cases). The vast majority of outbreaks involve carnivorous fish including snappers, groupers, wrasses, and barracudas. Since 2000, an expansion of the geographical range of CP has been observed in several areas like Macaronesia and east and southeast Asia. In some of these locales, random surveys confirmed the presence of CTXs in locally sourced fish, consistent with the concurrent report of novel CP incidents (e.g., Canary Islands, Madeira, Selvagens Islands, New South Wales). One characteristic of outbreaks occurring in Asia is that they often present as large disease clusters due to group consumption of a single contaminated fish. Similar observations are reported from the Indian Ocean in the form of shark poisoning outbreaks which often lead to singular types of CP characterized by a high fatality rate. Other atypical forms of CP linked to the consumption of marine invertebrates also have been documented recently. Owing to the significant health, socioeconomic and socio-cultural impacts of ciguatera, there is an urgent need for increased, standardized, coordinated efforts in ciguatera education, monitoring and research programs. Several regional and international initiatives have emerged recently, that may help improve patients' care, data collection at a global scale, and risk monitoring and management capabilities in countries most vulnerable to CP's toxic threat.
•A geographical expansion of ciguatera poisoning incidents is observed since 2000.•Atypical forms of CP involving sharks and marine invertebrates are reported.•CP cases and outbreaks remain largely under-reported on a global level.•Gambierdiscus and Fukuyoa spp. global distribution is updated and summarized.
For high precision measurements of K decays, the presence of radiated photons cannot be neglected. The Monte Carlo simulations must include the radiative corrections in order to compute the correct ...event counting and for efficiency calculations. In this paper, a method for simulating such decays is briefly described.
A ferromagnetic axion haloscope searches for dark matter in the form of axions by exploiting their interaction with electronic spins. It is composed of an axion-to-electromagnetic field transducer ...coupled to a sensitive rf detector. The former is a photon-magnon hybrid system, and the latter is based on a quantum-limited Josephson parametric amplifier. The hybrid system consists of ten 2.1 mm diameter yttrium iron garnet spheres coupled to a single microwave cavity mode by means of a static magnetic field. Our setup is the most sensitive rf spin magnetometer ever realized. The minimum detectable field is 5.5×10^{-19} T with 9 h integration time, corresponding to a limit on the axion-electron coupling constant g_{aee}≤1.7×10^{-11} at 95% C.L. The scientific run of our haloscope resulted in the best limit on dark matter axions to electron coupling constant in a frequency span of about 120 MHz, corresponding to the axion-mass range 42.4-43.1 μeV. This is also the first apparatus to perform a wide axion-mass scanning by only changing the static magnetic field.
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•An alternative to cantilever beam-type systems for energy harvesting is proposed.•The device generates energy in a low frequency rotational environment.•It comprises two beams, a ...spring and two heavy masses joined by the spring.•By varying the flexibility of one beam, the device increments output DC power.•The generated DC power suffices to feed low power wireless transmitters.
We present a novel design of a rotational power scavenging system as an alternative to cantilever beams attached to a hub. The device is meant to provide energy to wireless autonomous monitoring systems in low frequency environments such as wind turbines of 30kW with rotational speeds of between 50 and 150rpm. These characteristics define the bandwidth of the rotational energy harvesting system (REH) and its physical dimensions. A versatile geometric configuration with two elastic beams and two heavy masses joined by a spring is proposed. A piezoelectric sheet is mounted on the primary beam while the REH is placed on a rotating hub with the gravitational force acting as a periodic source. This kind of double-beam system offers the possibility to modify the vibration characteristics of the harvester for achieving high power density. An analytical framework using the Lagrangian formulation is derived to describe the motion of the system and the voltage output as a function of rotation speed. Several sets of experiments were performed to characterize the system and to validate the assumed hypothesis. In the experimental setup, a wireless data acquisition system based on Arduino technology was implemented to avoid slip-ring mechanisms. The results show very good agreement between the theoretical and experimental tests. Moreover, the output power of a simple harvesting circuit, which serves as an energy storage device, yields values ranging 26–105μW over the whole frequency range. This allows us to use the proposed device for the designed purpose, taking into account the power requirements of commercially available wireless transmitter systems.
Habitat loss and fragmentation have negatively impacted breeding birds across the world. Across guilds, grassland‐dependent birds have experienced the largest proportional loss of their breeding ...population while wetland‐dependent birds have realized overall net gains in part due to focused conservation efforts. However, some species within the wetland‐dependent guild have a strong dependence on non‐wetland land cover types during the annual cycle and therefore may be equally sensitive to reductions in the composition and altered configuration of upland landcover, such as grasslands. We explored the influence of landcover composition and configuration on the number of breeding pairs of a breeding habitat generalist, the mallard (Anas platyrhynchos), and a grassland‐dependent breeding species, the blue‐winged teal (Spatula discors), in agriculturally‐intensive landscapes of Wisconsin, USA. Because of the extensive landscape alteration and habitat fragmentation that has occurred, we expected mallards to have a more utilitarian response to varying landscape composition compared to a grassland nesting obligate like blue‐winged teal. We used helicopter surveys conducted across 8 years (2001–2003, 2006–2009, and 2012) and remotely‐sensed land cover data to investigate the influence of habitat associations on relative abundance of breeding pairs. Model selection indicated that landscape composition models outperformed landscape configuration and null models for both species. Consistent with our predictions, we found that mallard pair counts were positively influenced by a greater number of land cover covariates compared to blue‐winged teal. Both blue‐winged teal and mallard breeding pairs were positively related to increased composition of emergent and scrub‐shrub wetlands as well as upland grassland. Additionally, we found that mallard pairs were positively related to forested, cattail (Typha sp.), and open water wetland types, whereas predicted blue‐winged teal pair abundance was negatively related to forested wetlands and had a nonlinear relationship and declined when surveyed land sections were comprised of more than 30% cattail‐dominated wetlands and 20% open‐water wetlands. Increased quantities of cattail‐dominated and open‐water wetland cover types comparatively provide less habitat for blue‐winged teal and may reflect broader shifts in habitat composition that have likely resulted from agricultural intensification and stabilized hydrology. Conservation activities that preserve existing nesting land cover types or restore hydrologically‐dynamic emergent wetlands in proximity to upland grassland cover could mutually benefit both species.
We explored the influence of land cover composition and configuration on the number of breeding pairs of a breeding habitat generalist, the mallard (Anas platyrhynchos) and a grassland‐dependent breeding species, the blue‐winged teal (Spatula discors) in agriculturally intensive landscapes of Wisconsin, USA, to inform management actions that seek to improve breeding waterfowl habitat. Model selection indicated that landscape composition models outperformed landscape configuration and null models for both species. Conservation activities that preserve existing nesting land cover types or restore hydrologically dynamic emergent wetlands in proximity to upland grassland cover could mutually benefit both species.
By calling on modelling approaches we have performed a comparative study on the redox properties of various naphtho-, biphenyl- and biphenylene-quinone isomers. These different compounds exhibit as a ...whole a redox potential range between 2.09 and 2.90 V
vs.
Li
+
/Li. A specific methodology was used to decrypt the interplay among isomerism, aromaticity and antiaromaticity modifications and the stabilization/destabilization effects due to other molecular components on this key electrochemical feature for electrode materials of batteries. In particular, energy decomposition analysis, within the Quantum Theory of Atoms in Molecules, along with the electron and electron spin population changes upon reduction nicely rationalise the observed potential trends. While 1,2- and 2,3-isomers show the highest/lowest redox potential in the biphenylene-quinone series, a reverse trend is observed for the naphtho-quinone, the compound having the two carbonyl groups on distinct rings being characterized by an intermediate value in both cases. There is instead almost no differentiation between 1,2 and 2,3 isomers for the biphenyl-quinone family.
By calling on modelling approaches we have performed a comparative study on the redox properties of various naphtho-, biphenyl- and biphenylene-quinone isomers.
AbstractCiguatera is a non-bacterial seafood poisoning highly prevalent in French Polynesia where it constitutes a major health issue and a major threat to food sustainability and food security for ...local populations. Ciguatera results from the bioaccumulation in marine food webs of toxins known as ciguatoxins, originating from benthic dinoflagellates in the genera Gambierdiscus and Fukuyoa. Ciguatera is characterized by a complex array of gastrointestinal, neurological and cardiovascular symptoms. The effective management of patients is significantly hampered by the occurrence of atypical forms and/or chronic sequelae in some patients, and the lack of both a confirmatory diagnosis test and a specific antidote. In addition, recent findings have outlined the implication of novel species of the causative organisms as well as new vectors, namely marine invertebrates, in ciguatera outbreaks. Another novel trend relates to the geographical expansion of this disease to previously unaffected areas, not only in certain island groups of French Polynesia but also in temperate regions worldwide, as a likely consequence of the effects of climate change.
•French Polynesia is a biodiversity hotspot for Gambierdiscus species.•Gambierdiscus polynesiensis is the main source of ciguatoxins in French Polynesia.•Herbivores and omnivores can be as toxic as ...carnivores in French Polynesia.•French Polynesia has a long-term epidemiological surveillance program on CP.•Cultural ramifications of CP have strong implications for risk management strategies.
Ciguatera Poisoning (CP) is a seafood poisoning highly prevalent in French Polynesia. This illness results from the consumption of seafood contaminated with ciguatoxins (CTXs) produced by Gambierdiscus, a benthic dinoflagellate. Ciguatera significantly degrades the health and economic well-being of local communities largely dependent on reef fisheries for their subsistence. French Polynesia has been the site of rich and active CP research since the 1960′s. The environmental, toxicological, and epidemiological data obtained in the frame of large-scale field surveys and a country-wide CP case reporting program conducted over the past three decades in the five island groups of French Polynesia are reviewed. Results show toxin production in Gambierdiscus in the natural environment may vary considerably at a temporal and spatial scale, and that several locales clearly represent Gambierdiscus spp. “biodiversity hotspots”. Current data also suggest the “hot” species G. polynesiensis could be the primary source of CTXs in local ciguateric biotopes, pending formal confirmation. The prevalence of ciguatoxic fish and the CTX levels observed in several locales were remarkably high, with herbivores and omnivores often as toxic as carnivores. Results also confirm the strong local influence of Gambierdiscus spp. on the CTX toxin profiles characterized across multiple food web components including in CP-prone marine invertebrates. The statistics, obtained in the frame of a long-term epidemiological surveillance program established in 2007, point towards an apparent decline in the number of CP cases in French Polynesia as a whole; however, incidence rates remain dangerously high in some islands. Several of the challenges and opportunities, most notably those linked to the strong cultural ramifications of CP among local communities, that need to be considered to define effective risk management strategies are addressed.
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