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1.
Sci Total Environ ; 944: 173845, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-38871314

RESUMO

Terrestrial ectotherms are vulnerable to climate change since their biological rates depend on the ambient temperature. As temperature may interact with toxicant exposure, climate change may cause unpredictable responses to toxic stress. A population's thermal adaptation will impact its response to temperature change, but also to interactive effects from temperature and toxicants, but these effects are still not fully understood. Here, we assessed the combined effects of exposure to the insecticide imidacloprid across the temperatures 10-25 °C of two populations of the Collembola Hypogastrura viatica (Tullberg, 1872), by determining their responses in multiple life history traits. The con-specific populations differ considerably in thermal adaptations; one (arctic) is a temperature generalist, while the other (temperate) is a warm-adapted specialist. For both populations, the sub-lethal concentrations of imidacloprid became lethal with increasing temperature. Although the thermal maximum is higher for the warm-adapted population, the reduction in survival was stronger. Growth was reduced by imidacloprid in a temperature-dependent manner, but only at the adult life stage. The decrease in adult body size combined with the absence of an effect on the age at first reproduction suggests a selection on the timing of maturation. Egg production was reduced by imidacloprid in both populations, but the negative effect was only dependent on temperature in the warm-adapted population, with no effect at 10 °C, and decreases of 41 % at 15 °C, and 74 % at 20 °C. For several key traits, the population best adapted to utilize high temperatures was also the most sensitive to toxic stress at higher temperatures. It could be that by allocating more energy to faster growth, development, and reproduction at higher temperatures, the population had less energy for maintenance, making it more sensitive to toxic stress. Our findings demonstrate the need to take into account a population's thermal adaptation when assessing the interactive effects between temperature and other stressors.


Assuntos
Mudança Climática , Inseticidas , Neonicotinoides , Nitrocompostos , Temperatura , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Animais , Inseticidas/toxicidade , Artrópodes/efeitos dos fármacos , Artrópodes/fisiologia , Poluentes do Solo/toxicidade , Solo/química , Adaptação Fisiológica , Imidazóis/toxicidade
2.
Ecotoxicology ; 32(10): 1209-1220, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37989986

RESUMO

Standard toxicity tests expose springtails (Collembola) through soil, while dietary exposure tests with animals visible on a surface are less commonly applied. We refined a method for dietary chemical exposure for two widely distributed and abundant Collembola species: Folsomia quadrioculata and Hypogastrura viatica as existing methods were sub-optimal. Newly hatched Collembola were offered bark with a natural layer of Cyanobacteria that was either moistened with a solution of the neonicotinoid insecticide imidacloprid using a micropipette or soaked in the solution overnight. The first method was superior in producing a measured concentration close to the nominal (0.21 and 0.13 mg/kg dry bark, respectively), and resulting in sub-lethal effects as expected. The adult body size was reduced by 8% for both species, but egg production only in H. viatica. Contrastingly, soaked bark resulted in a measured concentration of 8 mg/kg dry bark, causing high mortality and no egg production in either species. Next, we identified the sub-lethal concentration-range by moistening the bark to expose H. viatica to 0, 0.01, 0.04, 0.13, 0.43 and 1.2 mg imidacloprid/kg dry bark. Only the highest concentration affected survival, causing a mortality of 77%. Imidacloprid reduced moulting rate and the body size at first reproduction. The age at first reproduction appeared delayed as some replicates did not reproduce within the experiment duration. The method of moistened bark for dietary exposure proved optimal to continuously study life history traits, such as growth and reproductive outcomes, which are important to understand effects on key events crucial for population viability and growth.


Assuntos
Artrópodes , Inseticidas , Animais , Exposição Dietética , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Inseticidas/toxicidade
3.
Environ Toxicol Chem ; 40(11): 3111-3122, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34352120

RESUMO

Collembola (springtails) are important members of soil communities worldwide by contributing to degradation of organic matter. In nature, Collembola might be exposed to the neonicotinoid insecticide imidacloprid, which is fairly persistent in soil. We exposed the widespread Hypogastrura viatica to imidacloprid through soil or food and monitored the animals during exposure and a post exposure period. We recorded effects on life-history traits affecting individual fitness, that is, mortality, behavioral activity, several reproduction traits, and molting frequency. Exposure through soil led to a concentration-dependent mortality, while the mortality from dietary exposure possibly reflected reduced feeding activity. The body burden of imidacloprid in the Collembola did not differ between treatments. We found no sign of recovery in behavioral activity following exposure in either experiment. The egg production of H. viatica was not significantly affected by imidacloprid at 0.01 mg/kg dry soil but showed a tendency to reduce number of eggs per batch and reduced hatching success. At higher concentrations, reproduction was close to, or completely, stopped. The molting frequency decreased during exposure, while in the post exposure period, we saw milder effects at the highest concentrations, suggesting elimination through molting or reduced toxic response as a result of reduced feeding activity. Overall, H. viatica was more sensitive to imidacloprid than previously studied Collembola, which highlights the importance of considering species sensitivities when risk-assessing soil environments. Environ Toxicol Chem 2021;40:3111-3122. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.


Assuntos
Artrópodes , Inseticidas , Animais , Artrópodes/fisiologia , Dieta , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Solo
4.
Environ Commun ; 15(2): 153-172, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33688373

RESUMO

Animal agriculture is a major producer of greenhouse gas emissions, equivalent to 14.5% of global emissions, which is approximately the same size as the transportation sector. Global meat consumption is projected to grow, which will increase animal agriculture's negative impact on the environment. Public awareness of the link between animal food consumption and climate change is low; this may be one of many obstacles to more effective interventions to reduce meat consumption in Western diets, which has been proposed by many research institutions. This study analyzes how much attention the UK and US elite media paid to animal agriculture's role in climate change, and the roles and responsibilities of various parties in addressing the problem, from 2006 to 2018. The results of the quantitative media content analysis show that during that period, volume of coverage remained low, and that when the issue was covered, consumer responsibility was mentioned more than that of governments or largescale livestock farms. In similar fashion, a range of options around personal dietary change was far more prominent in the media discussion of solutions than government policies, reforming agricultural practices or holding major animal food companies accountable for their emissions.

5.
Clim Change ; 162(4): 2379-2396, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33132466

RESUMO

'Cultured' meat has attracted a considerable amount of investor and media interest as an early-stage technology. Despite uncertainties about its future impact, news media may be contributing to promissory discourses, by stressing the potential benefits from cultured meat to the environment, health, animal welfare, and feeding a growing population. The results from a content analysis of 255 articles from 12 US and UK traditional media from 2013 to 2019 show that much of the coverage is prompted by the industry sector, whose representatives are also the most quoted. Positive narratives about cultured meat are much more prominent than cautionary ones. Our findings support previous scholarship on other emerging technologies which concluded that with important variations, media treatments are largely positive.

6.
Environ Sci Technol ; 53(21): 12835-12845, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31589028

RESUMO

Arctic-breeding seabirds contain high levels of many anthropogenic contaminants, which they deposit through guano to the tundra near their colonies. Nutrient-rich soil in vicinity to seabird colonies are favorable habitats for soil invertebrates, such as springtails (Collembola), which may result in exposure to seabird-derived contaminants. We quantified a wide range of lipid-soluble and protein-associated environmental contaminants in two springtail species (Megaphorura arctica and Hypogastrura viatica) and their respective habitats (soil/moss) collected underneath seabird cliffs. Although springtails are commonly used in laboratory toxicity tests, this is the first study to measure concentrations of persistent organic pollutants (POPs) and mercury (Hg) in springtails from the field, and to study biotransportation of contaminants by seabirds to soil fauna. We categorized the sites a priori as of low, medium, or high seabird influence, based on the seabird abundance and species composition. This ranking was reflected in increasing δ15N values in soil/moss and springtails with increasing seabird influence. We found clear indications of seabirds impacting the terrestrial soil environments with organic contaminants, and that concentrations were higher in soil and moss close to the bird cliff, compared to farther away. However, we did not find a relationship between contaminant concentration in springtails and the concentrations in soil/moss, or with level of seabird influence. Our study indicates a low uptake of contaminants in the soil fauna, despite seabird-derived contamination of their habitat.


Assuntos
Artrópodes , Solo , Animais , Regiões Árticas , Monitoramento Ambiental , Tundra
7.
Public Underst Sci ; 27(7): 836-856, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29336218

RESUMO

Few studies have assessed whether populations can be divided into segments with different perceptions of science. We provide such an analysis and assess whether these segments exhibit specific patterns of media and information use. Based on representative survey data from Switzerland, we use latent class analysis to reconstruct four segments: the "Sciencephiles," with strong interest for science, extensive knowledge, and a pronounced belief in its potential, who use a variety of sources intensively; the "Critically Interested," also with strong interest and support for science but with less trust in it, who use similar sources but are more cautious toward them; the "Passive Supporters" with moderate levels of interest, trust, and knowledge and tempered perceptions of science, who use fewer sources; and the "Disengaged," who are not interested in science, do not know much about it, harbor critical views toward it, and encounter it-if at all-mostly through television.

8.
Oncotarget ; 7(7): 8105-18, 2016 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-26812881

RESUMO

Palliative care in acute myeloid leukaemia (AML) is inadequate. For elderly patients, unfit for intensive chemotherapy, median survival is 2-3 months. As such, there is urgent demand for low-toxic palliative alternatives. We have repositioned two commonly administered anti-leukaemia drugs, valproic acid (VPA) and hydroxyurea (HU), as a combination therapy in AML. The anti-leukemic effect of VPA and HU was assessed in multiple AML cell lines confirming the superior anti-leukemic effect of combination therapy. Mechanistic studies revealed that VPA amplified the ability of HU to slow S-phase progression and this correlated with significantly increased DNA damage. VPA was also shown to reduce expression of the DNA repair protein, Rad51. Interestingly, the tumour suppressor protein p53 was revealed to mitigate cell cycle recovery following combination induced arrest. The efficacy of combination therapy was validated in vivo. Combination treatment increased survival in OCI-AML3 and patient-derived xenograft mouse models of AML. Therapy response was confirmed by optical imaging with multiplexed near-infrared labelled antibodies. The combination of HU and VPA indicates significant potential in preclinical models of AML. Both compounds are widely available and well tolerated. We believe that repositioning this combination could significantly enhance the palliative care of patients unsuited to intensive chemotherapy.


Assuntos
Sinergismo Farmacológico , Hidroxiureia/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Proteína Supressora de Tumor p53/genética , Ácido Valproico/farmacologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticonvulsivantes/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Estudos de Casos e Controles , Proliferação de Células/efeitos dos fármacos , Feminino , Imunofluorescência , Seguimentos , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Pessoa de Meia-Idade , Mutação/genética , Estadiamento de Neoplasias , Prognóstico , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
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