A new method to assess the acute toxicity toward honeybees of the abrasion particles generated from seeds coated with insecticides

Abstract Background: Large amounts of insecticide-containing dusts produced from abrasion of the seed dressing can be released into the atmosphere during sowing operations. Neonicotinoid pesticides, introduced in the 1990s for several crops, are the leading products for seed-coating treatments in many countries. Neonicotinoid containing dusts can be efectively intercepted by bees in fight over the sowing feld, inducing lethal acute efects, so that restrictions in the use of the main neonicotinoids have been adopted in the European Union. This led to the consequent introduction of replacement insecticides for seed-coating, i.e. methiocarb and thiacloprid, despite the lack of information on both the toxicity and the exposure scenarios for honeybees. Results: In this study, a laboratory apparatus was developed in order to quantify the toxicity of the dusts produced from the abrasion of the seed coating. This quantifcation is based on (i) an airstream transporting coating particles into an exposure chamber; (ii) exposure of bees to reproducible and measurable concentrations of insecticide, and (iii) direct measurement of the exposure dose on single bees. The method allowed us to perform in vivo experiments of honeybee exposure to provide toxicity data in more realistic exposure conditions. In fact, the formulation rather than the active principle alone can be tested, and the exposure is through dusts rather than a solution so that specifc absorption behavior can be studied in representative environmental conditions. The method was used to quantify the acute toxicity (LD50) of dusts obtained from the abrasion of corn seeds coated with clothianidin, thiacloprid and methiocarb. Conclusions: Our results show that, surprisingly, the replacement insecticide methiocarb has a toxicity (LD50=421– 693 ng/bee) in the same order of magnitude as clothianidin (LD50=113–451 ng/bee) through this specifc exposure route, while thiacloprid (LD50=16.9·103 ng/bee) has a signifcantly lower acute toxicity. Moreover, dusts containing methiocarb and clothianidin show a signifcant increase in toxicity when, after exposure, bees are kept under high humidity conditions. This suggests that the method here presented can be used to obtain complementary toxicity data in the risk assessment procedure for the authorization of new seed-coating insecticides or new formulations. Keywords: Systemic insecticides, Neonicotinoids, Methiocarb, Seed coating, Abrasion dusts, Honeybees, Pollinator insects, Acute toxicity, Exposure measuremen

Extreme flooding events in coastal lagoons: seawater parameters and rainfall over a six-year period in the Mar Menor (SE Spain)

Climate change is one of the main problems currently strongly conditioning ecosystems all over the world. Coastal lagoons are amongst the most vulnerable habitats, and they are undergoing extensive human impact due to their high production rates and the close proximity of urban and agricultural centers. The Mar Menor, the largest saltwater lagoon in Europe, is an example of a highly impacted ecosystem. In December 2016 and September 2019, climate change-induced DANA (upper-level isolated atmospheric depression) flooding events took place there, temporarily altering the lagoon oceanographic properties. Data gathered throughout the lagoon (11 stations inside and 1 outside the lagoon) from 2016 to 2021 were analyzed in order to assess the variability of seawater parameters: salinity, density, chlorophyll-a, turbidity, and dissolved oxygen, due to DANA events. Results showed a change in seawater parameters that were reestablished at different rates, 4 and 10 months in 2016 and 2019, respectively, following a description of the environmental conditions and effects that have been reported after extreme rainfall in the lagoon. The amount of rainfall correlated with changes in the analyzed seawater parameters, such as an increase in turbidity and chlorophyll-a values. Furthermore, turbidity correlated with chlorophyll-a and oxygen saturation, while density correlated with salinity. Such extreme weather events are worsened by climate change, growing more frequent and between shorter intervals in time. In order to decelerate ecosystem decline, comprehensive management plans are needed to address the various factors that might add to anthropic impacts in natural environments

The double traveling salesman problem with partial last-in-first-out loading constraints

In this paper, we introduce the double traveling salesman problem with partial last-in-first-out loading constraints (DTSPPL). It is a pickup-and-delivery single-vehicle routing problem, where all pickup operations must be performed before any delivery operation because the pickup-and-delivery areas are geographically separated. The vehicle collects items in the pickup area and loads them into its container, a horizontal stack. After performing all pickup operations, the vehicle begins delivering the items in the delivery area. Loading and unloading operations must obey a partial last-in-first-out (LIFO) policy, that is, a version of the LIFO policy that may be violated within a given reloading depth. The objective of the DTSPPL is to minimize the total cost, which involves the total distance traveled by the vehicle and the number of items that are unloaded and then reloaded due to violations of the standard LIFO policy. We formally describe the DTSPPL through two integer linear programming (ILP) formulations and propose a heuristic algorithm based on the biased random-key genetic algorithm (BRKGA) to find high-quality solutions. The performance of the proposed solution approaches is assessed over a broad set of instances. Computational results have shown that both ILP formulations have been able to solve only the smaller instances, whereas the BRKGA obtained good-quality solutions for almost all instances, requiring short computational times

An Experimental Study on Kinetics-Controlled Ca-Carbonate Aqueous Reduction into CH4 (1 and 2 GPa, 550 degrees C): Implications for C Mobility in Subduction Zones

Abiotic methane (CH4) generation under subduction zone conditions has been experimentally investigated through aqueous reduction of pure C-bearing materials (e.g. carbonate minerals and organic matter). However, quantitative assessments of CH(4 )production in these experiments, as well as the potential effects of other components such as SiO2 on the reduction processes, have not yet been well established. Here, we performed experiments to quantitatively evaluate the time-resolved Ca-carbonate aqueous reduction into CH4 at P = 1 and 2 GPa and T = 550 degrees C in the CaO + COH, CaO + SiO2 COH, and CaO + SiO2 + MgO + COH systems, employing calcite + water +/- quartz +/- serpentine (synthetic chlorine (Cl)-bearing chrysotile and natural Fe-Al-bearing antigorite) as starting materials. Redox conditions of the experiments were buffered by iron-wilstite (IW) using a double capsule setting, corresponding to oxygen fugacity (fO(2)) values (expressed as log units relative to the fayalite-magnetite-quartz buffer, Delta FMQ) in the inner capsule of Delta FMQ approximate to -5.5 at 1 GPa and Delta FMQ approximate to -6.0 at 2 GPa. The solid products are mainly composed of portlandite +/- larnite +/- wollastonite +/- brucite, while Ca-carbonate and/or silicate reactants commonly occur as relicts. Quadrupole mass spectrometric analysis shows that CH4 and H2O are the major COH molecular species in the fluid products, with molar ratios between CH4 and starting calcite representing the reaction progress ranging from similar to 0.13 to similar to 1.00. Comparisons of experimental run products with thermodynamically predicted phase assemblages, together with time-series experiments, indicate that the reduction processes are primarily controlled by reaction kinetics. At 1 GPa and 550 degrees C, rate constants of 4.0 x 10(-6) s(-1), 7.4 x 10(-6) s(-1) , and 2.6 x 10(-6 )s(-1) were retrieved for reactions starting with calcite + quartz + water, calcite + synthetic Cl-bearing chrysotile + water, and calcite + natural Fe-Al-bearing antigorite + water, respectively, significantly higher than the constant of 0.8 x 10(-6) s(-1 )for the silicate-absent reaction. Besides, an increase in pressures can also enhance the reduction efficiency of Ca-carbonates until reaching equilibrium with the fluids. Our data provide experimental evidence for kinetics-controlled Ca-carbonate aqueous reduction into CH4 in subduction zones, indicating that silicate involvement and/or pressure increase can accelerate the reaction rates through short-lived fluid-rock interactions, which may have important implications for deep C mobility

Ovarian cancer identification based on dimensionality reduction for high-throughput mass spectrometry data

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Mutagenesis as a Diversity Enhancer and Preserver in Evolution Strategies

Proceedings of: 9th International Symposium on Distributed Computing and Artificial Intelligence (DCAI 2012). Salamanca, March 28-30, 2012Mutagenesis is a process which forces the coverage of certain zones of the search space during the generations of an evolution strategy, by keeping track of the covered ranges for the different variables in the so called gene matrix. Originally introduced as an artifact to control the automated stopping criterion in a memetic algorithm, ESLAT, it also improved the exploration capabilities of the algorithm, even though this was considered a secondary matter and not properly analyzed or tested. This work focuses on this diversity enhancement, redefining mutagenesis to increase this characteristic, measuring this improvement over a set of twenty-seven unconstrained optimization functions to provide statistically significant results.This work was supported in part by Projects CICYT TIN2008-06742-C02-02/TSI, CICYT TEC2008-06732-C02-02/TEC, CAM CONTEXTS (S2009/TIC-1485) and DPS2008-07029-C02-02.Publicad

Automated mobile virtual reality cognitive behavior therapy for aviophobia in a natural setting: a randomized controlled trial

Background: Access to evidence-based psychological treatment is a challenge worldwide. We assessed the effectiveness of a fully automated aviophobia smartphone app treatment delivered in combination with a $5 virtual reality (VR) viewer.Methods: In total, 153 participants from the Dutch general population with aviophobia symptoms and smartphone access were randomized in a single-blind randomized controlled trial to either an automated VR cognitive behavior therapy (VR-CBT) app treatment condition (n = 77) or a wait-list control condition (n = 76). The VR-CBT app was delivered over a 6-week period in the participants' natural environment. Online self-report assessments were completed at baseline, post-treatment, at 3-month and at 12-month follow-up. The primary outcome measure was the Flight Anxiety Situations Questionnaire (FAS). Analyses were based on intent-to-treat.Results: A significant reduction of aviophobia symptoms at post-test for the VR-CBT app compared with the control condition [p Conclusions: This study is the first to show that fully automated mobile VR-CBT therapy delivered in a natural setting can maintain long-term effectiveness in reducing aviophobia symptoms. In doing so, it offers an accessible and scalable evidence-based treatment solution that can be applied globally at a fraction of the cost of current treatment alternatives

Long-term effects of an informal education program on tourist environmental perception

Tourism is one of the most important economic sectors worldwide, with significant overarching impact on the environment, including negative effects caused by tourist inappropriate behavior while on vacation. By providing informal educational activities, tourism also has an educative role that leads to positive learning outcomes and beneficial environmental effects. Here we present the short- and long-term outcomes of a project for environmental education (Glocal Education) carried out in three travel destinations, aimed at promoting sustainability variables (knowledge, attitude, and awareness) in participating tourists. Since psychological components can affect learning outcomes, we also considered tourist satisfaction in participating in the project and identification with its values, as well as the intention to travel with the hosting tour operator again in the future. Tourists were asked to complete evaluation questionnaires three times: before Glocal Education activities, right after activities (i.e., while still on vacation), and after at least one year from initial project participation. Short- and long-term learning outcomes were tested, and possible relations between these variables and psychological components (satisfaction, identification, and intention) of the learning experience were verified. Overall, knowledge, attitude and awareness increased in the short term, while in the long term, knowledge and attitude decreased, and awareness remained constant. In most cases, psychological components showed positive relation with sustainability variables, which suggested their important role in structuring and carrying out environmental education activities. This study suggests that informal environmental education activities can be advantageous for tourism stakeholders in terms of customer loyalty. Such activities can contribute to enhance environment literacy, by allowing tourists to observe the environmental impact caused by human activity, and understand how their day-to-day actions, even if small, might help address some of the current concerns for environmental conservation

Minimal model estimation of glucose absorption and insulin sensitivity from oral test : validation with a tracer method

Measuring insulin sensitivity during the physiological milieu of oral glucose perturbation, e.g., a meal or an oral glucose tolerance test, would be extremely valuable but difficult since the rate of appearance of absorbed glucose is unknown. The reference method is a tracer two-step one: first, the rate of appearance of glucose (R(a meal)(ref)) is reconstructed by employing the tracer-to-tracee ratio clamp technique with two tracers and a model of non-steady-state glucose kinetics; next, this R(a meal)(ref) is used as the known input of a model describing insulin action on glucose kinetics to estimate insulin sensitivity (SI(ref)). Recently, a nontracer method based on the oral minimal model (OMM) has been proposed to estimate simultaneously the above quantities, denoted R(a meal) and SI, respectively, from plasma glucose and insulin concentrations measured after an oral glucose perturbation. This last method has obvious advantages over the tracer method, but its domain of validity has never been assessed against a reference method. It is thus important to establish whether or not the "nontracer" R(a meal) and SI compare well with the "tracer" R(a meal)(ref) and SI(ref). We do this comparison on a database of 88 subjects, and it is very satisfactory: R(a meal) profiles agree well with the R(a meal)(ref) and correlation of SI(ref) with SI is r = 0.86 (P < 0.0001). We conclude that OMM candidates as a reliable tool to measure both the rate of glucose absorption and insulin sensitivity from oral glucose tests without employing tracers

Alternative splicing of the histone demethylase LSD1/KDM1 contributes to the modulation of neurite morphogenesis in the mammalian nervous system

A variety of chromatin remodeling complexes are thought to orchestrate transcriptional programs that lead neuronal precursors from earliest commitment to terminal differentiation. Here we show that mammalian neurons have a specialized chromatin remodeling enzyme arising from a neurospecific splice variant of LSD1/KDM1, histone lysine specific demethylase 1, whose demethylase activity on Lys4 of histone H3 has been related to gene repression. We found that alternative splicing of LSD1 transcript generates four full-length isoforms from combinatorial retention of two identified exons: the 4 aa exon E8a is internal to the amine oxidase domain, and its inclusion is restricted to the nervous system. Remarkably, the expression of LSD1 splice variants is dynamically regulated throughout cortical development, particularly during perinatal stages, with a progressive increase of LSD1 neurospecific isoforms over the ubiquitous ones. Notably, the same LSD1 splice dynamics can be fairly recapitulated in cultured cortical neurons. Functionally, LSD1 isoforms display in vitro a comparable demethylase activity, yet the inclusion of the sole exon E8a reduces LSD1 repressor activity on a reporter gene. Additional distinction among isoforms is supported by the knockdown of neurospecific variants in cortical neurons resulting in the inhibition of neurite maturation, whereas overexpression of the same variants enhances it. Instead, perturbation of LSD1 isoforms that are devoid of the neurospecific exon elicits no morphogenic effect. Collectively, results demonstrate that the arousal of neuronal LSD1 isoforms pacemakes early neurite morphogenesis, conferring a neurospecific function to LSD1 epigenetic activity