Species Differences In Sensitivity Research Articles

Extreme winter weather disrupts bird occurrence and abundance patterns at geographic scales

Extreme weather events are increasing in frequency and intensity as a result of modern climate change. During winter, species may be especially vulnerable to extreme weather as they are surviving on scarce resources and living at the edge of their thermal limits. We compiled data from eBird, a global citizen science initiative, to examine how 41 eastern North American birds shifted their occurrence and abundance patterns immediately following two recent extreme weather events each affecting > 2 million km2, the intrusion of a polar vortex and a winter heat wave. eBird data is continuously collected at high spatiotemporal resolution across large spatial extents, allowing us to compare species' responses immediately before and after these extreme events with trends in other winters across geographic scales. Overall, we found that birds responded differently to each extreme weather event. Bird occurrence rates did not change following the polar vortex, but where species occurred, population density was temporarily reduced, suggesting reductions in number of individuals driven by decreases in behavioral activity or temporary movement out of the area. However, birds demonstrated widespread increases in occurrence and increases in density and number of individuals where they occurred for at least 20 days after the heat wave, hinting at longer‐term range changes. Smaller‐bodied, warm‐adapted passerines tended to be most sensitive to extreme weather and responded most negatively to the polar vortex and most positively to the heat wave, while larger‐bodied, cold‐adapted waterbirds expressed only mild responses to either event. Thus, certain species may be exceptionally sensitive to extreme weather events while others are less sensitive. As climate change progresses and climatic variability increases, researchers and managers must better quantify the broad‐scale sensitivity of different species to multiple types of extreme weather events.

Growth Inhibition and Oxidative Stress in Two Green Algal Species Exposed to Erythromycin

AbstractChlorella vulgaris (C. vulgaris) and Raphidocelis subcapitata (R. subcapitata) are two model algal species applied for the testing of chemicals, whereas a considerable variation in their sensitivity to antibiotics has been reported. The difference in species sensitivity may be attributed to the xenobiotic‐induced oxidative stress in algal cells. Thus, this study compared the responses of these two model green algae toward the exposure of erythromycin (ERY), a macrolide antibiotic, at the concentration levels of 0, 20, 40, 60 μg/L, and elucidated the toxic mechanism of action from the point of oxidative damage and antioxidant defense. To achieve this, effects on the endpoints of algal growth, malondialdehyde (MDA), antioxidants (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GP], glutathione, and glutathione S‐transferase), and photosynthetic pigment contents were evaluated. After exposing for seven days, the growth of R. subcapitata was significantly stimulated at ERY 20 μg/L but inhibited at the higher exposure level of 60 μg/L. Contrarily, hormesis in C. vulgaris exposed to all ERY treatments was detected. With the increase in ERY exposure, MDA content, and the antioxidant activity of SOD, CAT, GP in R. subcapitata were gradually enhanced. In C. vulgaris, a declining trend in the MDA content and the activity of SOD, CAT, and GP was detected. These results provide insights into the ERY‐altered production of reactive oxygen species and the antioxidant responses in two algae.

The toxicity and toxicokinetics of imidacloprid and a bioactive metabolite to two aquatic arthropod species

• Amongst the four tested metabolites of imidacloprid (IMI), IMI-ole was the only one found to show a toxic effect to both Cloeon dipterum and Gammarus pulex . • C. dipterum biotransformed more IMI to IMI-ole compared to the more tolerant species G. pulex. • IMI-ole showed a similar toxicity to C. dipterum as IMI and was hardly eliminated. • The generation of a bioactive metabolite, IMI-ole, could explain the difference in sensitivity and time-cumulative toxicity effects of IMI. Previous studies have explored effects of imidacloprid and its metabolites on terrestrial species, such as bees, and indicated the importance of some active metabolites. However, the biotransformation of IMI and the toxicity of its metabolites to aquatic arthropods are largely unknown, especially the mechanisms driving species sensitivity differences and time-cumulative toxicity effects. To assess the potential effects of the metabolization of IMI and the toxicokinetics and toxicity of the metabolite(s) on aquatic arthropods, we first studied the acute toxicity of IMI and relevant metabolites to the mayfly species Cloen dipterum (sensitive to IMI) and the amphipod species Gammarus pulex (less sensitive to IMI). Secondly, toxicokinetic experiments were conducted using both the parent compound and imidacloprid-olefin (IMI-ole), a metabolite assessed as toxic in the acute tests and defined as bioactive. Of the four tested metabolites, only IMI-ole was readily biotransformed from the parent IMI and showed similar toxicity to C. dipterum as IMI. However, C. dipterum was hardly able to eliminate IMI-ole from its body. For G. pulex , IMI-ole was also the only detected metabolite causing toxicity, but the biotransformation of IMI to IMI-ole was slower and lower in G. pulex compared to C. dipterum, and G. pulex eliminated IMI-ole quicker than C. dipterum . Our results on internal kinetics of IMI and IMI-ole, and on biotransformation of IMI indicated that the metabolite IMI-ole was toxic and was rather persistent inside the body tissue of both invertebrate species, especially for C. dipterum . In conclusion, as IMI and IMI-ole have similar toxicity and IMI was replaced rapidly by IMI-ole which in turn was poorly eliminated by C. dipterum , the overall toxicity is a function of dose and time. As a result, no long-term threshold of effects of IMI may exist for C. dipterum as the poor elimination results in an ongoing increase of toxicity over time for mayflies as also found experimentally in previous published papers.

PCR and multiplex PCR assays for the detection of Cronobacter species using specific targets obtained by a bioinformatics approach

Cronobacter species are opportunistic pathogens associated with severe infections in immunocompromised individuals. Species differentiation is essential as the sensitivity of different species to chemical reagents, antibiotics, and virulence factors may be diverse. This study aimed to mine new molecular targets for the detection of Cronobacter strains at the species level. Using a bioinformatics approach and the online BLAST software, we obtained serial Cronobacter species-specific target genes. Primers for the selected genes were constructed, and the PCR products were evaluated using various Cronobacter species and non-Cronobacter strains. As a result, 2, 5, 7, and 5 specific target genes were found for C. sakazakii, C. malonaticus, C. dublinensis, and C. turicensis, respectively. Thereafter, 4- and 5-multiplex PCR (mPCR) was successfully developed to identify these four species based on the validated species-specific primers. Overall, our data indicated that PCR and mPCR assays have excellent specificity and sensitivity for the detection of Cronobacter species, suggesting the potential of their use in food inspection and clinical diagnosis.

Technological Classification of Cadmium Quality in the Rice Producing Areas of South China

Classifying the quality of agricultural products is an important means of managing the arable land quality and guaranteeing the quality and safety of agricultural products. This work is planned to be completed in 2020. However, there is still no perfect method or technology for classifying the quality of arable lands. The species sensitivity distribution (SSD) has become commonly used for determining ecological safety thresholds since it takes into account differences in species sensitivity, the physical and chemical properties of soils, biological availability, and sources of pollutants. However, it has not yet been applied to the classification of arable land quality. Therefore, based on the routine monitoring data of rice production areas in southern China from the Agro-environmental Monitoring Center of China, this study proposes the use of species sensitivity distributions to classify the environmental quality of cadmium in rice production areas. The scientific rationale of this method was also discussed in order to provide an important reference for the construction and improvement of the classification system for arable land quality in China. The results showed that the pH, soil organic matter, and cation exchange capacity of the physical and chemical properties of soils significantly affected the enrichment of cadmium in rice, and this relationship was used to establish the cadmium transfer equation in the soil-rice system. It was found that there were obvious differences in the cadmium enrichment abilities of different rice varieties, which were mainly caused by the differences in their genotypes. According to the species sensitivity distributions, soil cadmium thresholds were obtained, which yielded a priority protection class of less than 0.26 mg·kg-1 and strict control class of greater than 1.67 mg·kg-1, between which are the safe use classes. The results were verified through independent datasets, and it was found that the application of species sensitivity distributions to classify the environmental quality of cadmium in rice producing areas reflected good scientific rationale and operability. This study may provide a foundation for the construction and improvement of the arable land quality classification system in China.

Sensitivity differences among five species of aquatic fungi and fungus-like organisms for seven fungicides with various modes of action.

Five species of aquatic fungi and fungus-like organisms were used for toxicity assays with seven fungicides to determine the differences in species sensitivity. A microplate toxicity assay with adenosine triphosphate luminescence detection was used as an efficient and economical high-throughput assay. The obtained toxicity data were standardized based on the species sensitivity distribution method. Species sensitivity differed among the fungicides: Rhizophydium brooksianum was most sensitive to hydroxyisoxazole, isoprothiolane, and ferimzone; Chytriomyces hyalinus was most sensitive to tricyclazole; Sporobolomyces roseus was most sensitive to ipconazole; Aphanomyces stellatus was most sensitive to orysastrobin and kasugamycin. Tetracladium setigerum was not the most sensitive species to any of the tested fungicides. The ranges of EC50s to fungal species were lower than to other aquatic organisms (primary producers, invertebrates, and vertebrates) for hydroxyisoxazole, kasugamycin, isoprothiolane, ipconazole, and ferimzone. These results suggest the usefulness of a battery of fungal species to assess the ecological effects of fungicides.

Assessment of water quality in Aguieira reservoir: Ecotoxicological tools in addition to the Water Framework Directive

To assess the ecological potential (EP), the Water Framework Directive (WFD) uses specific parameters but ignores ecosystem functioning and individual/subindividual biological responses. The heavily modified water bodies (reservoirs) are strongly influenced by human activities that promote their imbalance, with a loss or compromise the biodiversity and the functioning of these ecosystems. This work aims to determinate the EP according physical, chemical and biological parameters of WFD and evaluate the functionality and sensitivity of ecotoxicological tools in the evaluation of water quality of Aguieira reservoir. Four sampling sites were defined in Aguieira reservoir and sampling was conducted in autumn 2018, spring and autumn 2019. WFD showed overall that Aguieira reservoir presented moderate EP. The autumn samples and the two reservoir upstream sites had the worst classification. These results were complemented by a set of ecotoxicological assays (growth inhibition of Raphidocelis subcapitata and Spirodela polyrhiza, and feeding rate of Daphnia longispina) using three natural water treatments. R. subcapitata was the most sensitive species, indicating the presence of a risk that is not detected by chemical analysis, nor by organisms of different trophic levels. D. longispina only showed sensitivity in A3 and A4 in autumn, however this results was difficult to interpret since no reason can be observed to respond the F1 lower feeding rate observed in almost sites. S. polyrhiza, as well as the total chlorophyll, lipid peroxidation, and proline content did not show sensitivity, since no discrimination among the water treatments were recorded. The relevance of bioassays is associated with the fact that an integrated response to a complex mixture can be obtained, which can contain more substances than the measured ones. Thus, we may conclude that WFD are insufficient to draw conclusions about water quality, and the growth inhibition of Raphidocelis subcapitata assay is an important parameter to complement the WFD. In addition, species of different trophic levels are recommended for ecotoxicological analyses due to differences in species sensitivities.

Comparison of in situ sediment remediation amendments: Risk perspectives from species sensitivity distribution.

Contaminated sediment is a major issue for aquatic environments, but attention must be kept even during remediation activities that can negatively affect resident biota especially when applied in situ. For the first time, the species sensitivity distribution (SSD) approach was applied to amendments used for in situ sediment remediation considering 39 papers including both freshwater (F) and saltwater (S) effect data (i.e. n=17 only F, n=19 only S, and n=3 both F and S). Toxicity data related to the application of activated carbon (AC), nano-Zero-Valent-Iron (nZVI), apatite (A), organoclay (OC) and zeolite (Z) were collected and analyzed. SSD curves were constructed by lognormal model providing comprehensive comparisons of the sensitivities of different species to the relative testing methods. Results indicated that Bacteria were the most sensitive group of testing organisms, while Crustaceans were the less sensitive. The hazardous concentration for 5% of the affected species (HC5) were derived to determine the concentration protecting 95% of the species. OC, A and Z presented both acute and chronic toxicity. The HC5 values in descending order are: AC (4.79g/L)>nZVI (0.02g/L)>OC, A and Z (1.77E-04g/L). AC and nZVI can be considered safer than OC, A and Z in sediment remediation activities, even if in situ long-term effects remained still underexplored.

Biological effects of low-intensity radiofrequency fields and risk assessment for biota

Despite the fact that there are still conflicting opinions about the damage caused by modern wireless communication technologies, most scientists report on the negative biological effects of low-intensity radio frequency electromagnetic radiation at different levels of the organization of live nature. There is no doubt that there is a need not only for a sanitary and hygienic assessment of man-made electromagnetic effects on humans, but also for an environmental assessment for biota. The purpose of the study was to assess the potential environmental risk of electromagnetic impact in the centimeter range on natural ecosystems. The initial data were the authors' own results in the field of radiobiology of non-ionizing radiation, as well as published of other researchers. The article analyzes the biological effects of radio frequency electromagnetic fields detected in organisms of different systematic groups and levels of organization. The data on the non-thermal biological effects of electromagnetic fields indicate a high sensitivity of different species to this factor. The analyzed research results emphasize the need to take into account the features of non-thermal effects of electromagnetic radiation on biota, since these radiations can have a negative impact on different hierarchical levels in natural ecosystems.

Dugesia japonica is the best suited of three planarian species for high-throughput toxicology screening

High-throughput screening (HTS) using new approach methods is revolutionizing toxicology. Asexual freshwater planarians are a promising invertebrate model for neurotoxicity HTS because their diverse behaviors can be used as quantitative readouts of neuronal function. Currently, three planarian species are commonly used in toxicology research: Dugesia japonica, Schmidtea mediterranea, and Girardia tigrina. However, only D. japonica has been demonstrated to be suitable for HTS. Here, we assess the two other species for HTS suitability by direct comparison with D. japonica. Through quantitative assessments of morphology and multiple behaviors, we assayed the effects of 4 common solvents (DMSO, ethanol, methanol, ethyl acetate) and a negative control (sorbitol) on neurodevelopment. Each chemical was screened blind at 5 concentrations at two time points over a twelve-day period. We obtained two main results: First, G. tigrina and S. mediterranea planarians showed significantly reduced movement compared to D. japonica under HTS conditions, due to decreased health over time and lack of movement under red lighting, respectively. This made it difficult to obtain meaningful readouts from these species. Second, we observed species differences in sensitivity to the solvents, suggesting that care must be taken when extrapolating chemical effects across planarian species. Overall, our data show that D. japonica is best suited for behavioral HTS given the limitations of the other species. Standardizing which planarian species is used in neurotoxicity screening will facilitate data comparisons across research groups and accelerate the application of this promising invertebrate system for first-tier chemical HTS, helping streamline toxicology testing.

Ecological criteria for zinc in Chinese soil as affected by soil properties.

The increasing accumulation of zinc (Zn) in agricultural soils has led to the need to assess the potential risk of this element for terrestrial organisms. However, the soil ecological criteria in agricultural soil as a function of soil properties have been sparsely reported. In the present study, we derived the ecological criteria (expressed as predicted no effect concentration (PNEC)) for Zn in soils, based on ecotoxicity data for 19 terrestrial species in Chinese soils, the effect of soil properties on Zn ecotoxicity, differences in species sensitivity, and differences between laboratory and realistic field conditions. First, all ecotoxicity data of Zn for terrestrial organisms in Chinese soils were collected and filtered with given criteria to obtain reliable database. Second, the ecotoxicity data were normalized using Zn ecotoxicity predictive models to eliminate the effect of soil properties on Zn ecotoxicity, and corrected with leaching and aging factors to minimize the differences in Zn ecotoxicity under laboratory and field conditions. Then, species sensitivity distribution (SSD) curves were generated with a Burr Ⅲ function based on corrected ecotoxicity data. The concentration of Zn in soil that provides ecological safety for (100-x)% of species (HCx), was calculated from the SSD curve and HC5 was used for estimation of PNEC. Finally, we developed the predictive models for HCx by quantifying the relationship between the Zn HCx and soil properties. Results showed that soil pH was the most crucial factor affecting Zn HCx values, with HC5 values varying from 38.3mg/kg in an acidic soil to 263.3mg/kg in an alkaline calcareous soil. Both the two-factor (soil pH and OC) and the three-factor (soil pH, OC and CEC) models predicted HCx values well, with determination coefficients (R2) of 0.941-0.959 and 0.978-0.982, respectively. This study provides a scientific and reliable basis for the improvement of ecological risk assessment and the establishment of soil environmental quality standards.

Pyrrolizidine alkaloids in food and phytomedicine: Occurrence, exposure, toxicity, mechanisms, and risk assessment - A review

Among naturally occurring plant constituents, the 1,2-unsaturated pyrrolizidine alkaloids (in the following termed ‘PAs’) play a distinct role because of the large number of congeners occurring in nature and the pronounced toxicity of some congeners. Several PAs are hepatotoxic in humans, experimental and farm animals and were shown to be potent hepatocarcinogens in laboratory rodents. Although the general mode of action leading to toxicity has been elucidated, i.e., being mediated by metabolic conversion of the parent molecule into a highly reactive electrophile capable of attacking cellular target molecules, major questions related to the risk assessment of PAs remain unresolved.It was the aim of a workshop held in September 2018 to shed more light on the occurrence, exposure, mode of action, toxicokinetics and –dynamics of PAs to improve the scientific basis for an advanced toxicological risk assessment. The contributions in nine chapters describe the scientific progress using advanced analytical methods, studies in subcellular fractions, cell culture, experimental animals and humans and the use of PBPK modeling and structure-activity relationship considerations aiming at a better understanding of PA toxicity and genotoxicity. Since PAs differ considerably in their toxic potencies and substantial species differences in sensitivity towards PA exposure exist, a special emphasis was placed on these issues.

Sensitivity differences among seven algal species to 12 herbicides with various modes of action.

Seven algal species were used to conduct toxicity assays with 12 herbicides to determine differences in species sensitivity. A fluorescence microplate toxicity assay was used as an efficient and economical high-throughput assay. The obtained toxicity data were standardized based on the species sensitivity distribution concept. The most-sensitive individual species differed among herbicides: Desmodesmus subspicatus was most sensitive to chloronitrofen and pendimethalin; Achnanthidium minutissimum was most sensitive to chlorpropham; Nitzschia palea was most sensitive to diquat, glyphosate, and dichlobenil; Navicula pelliculosa was most sensitive to trifluralin; and Pseudanabaena foetida was most sensitive to glufosinate, asulam, and 2,4-D. Surprisingly, Raphidocelis (formerly Pseudokirchneriella) subcapitata, a standard green alga, was not the most sensitive to any of the herbicides. The results clearly showed that a single algal species cannot represent the algal assemblage in terms of sensitivity. Therefore, multispecies algal toxicity data sets are essential for assessing the ecological effect of herbicides.

Environmental degradation amplifies species' responses to temperature variation in a trophic interaction.

Land‐use and climate change are two of the primary drivers of the current biodiversity crisis. However, we lack understanding of how single‐species and multispecies associations are affected by interactions between multiple environmental stressors.We address this gap by examining how environmental degradation interacts with daily stochastic temperature variation to affect individual life history and population dynamics in a host–parasitoid trophic interaction, using the Indian meal moth, Plodia interpunctella, and its parasitoid wasp Venturia canescens.We carried out a single‐generation individual life‐history experiment and a multigeneration microcosm experiment during which individuals and microcosms were maintained at a mean temperature of 26°C that was either kept constant or varied stochastically, at four levels of host resource degradation, in the presence or absence of parasitoids.At the individual level, resource degradation increased juvenile development time and decreased adult body size in both species. Parasitoids were more sensitive to temperature variation than their hosts, with a shorter juvenile stage duration than in constant temperatures and a longer adult life span in moderately degraded environments. Resource degradation also altered the host's response to temperature variation, leading to a longer juvenile development time at high resource degradation. At the population level, moderate resource degradation amplified the effects of temperature variation on host and parasitoid populations compared with no or high resource degradation and parasitoid overall abundance was lower in fluctuating temperatures. Top‐down regulation by the parasitoid and bottom‐up regulation driven by resource degradation contributed to more than 50% of host and parasitoid population responses to temperature variation.Our results demonstrate that environmental degradation can strongly affect how species in a trophic interaction respond to short‐term temperature fluctuations through direct and indirect trait‐mediated effects. These effects are driven by species differences in sensitivity to environmental conditions and modulate top‐down (parasitism) and bottom‐up (resource) regulation. This study highlights the need to account for differences in the sensitivity of species’ traits to environmental stressors to understand how interacting species will respond to simultaneous anthropogenic changes.

Testing developmental toxicity in a second species: are the differences due to species or replication error?

Developmental toxicity studies for chemical and pharmaceutical safety are primarily performed in rats. Regulatory frameworks may require testing in a second, non-rodent species, for which the rabbit is usually chosen. This study shows that differences in NOAELs or LOAELs (N(L)OAELs) observed between rat and rabbit developmental toxicity studies performed according to OECD guidelines could just as well be caused by study replication errors, and not necessarily by differences in species sensitivity. This conclusion follows from an analysis of a database with rat and rabbit developmental toxicity studies for over 1000 industrial chemicals, pesticides, veterinary drugs and human pharmaceuticals, which included 143 compounds with multiple oral rat studies and 124 compounds with multiple oral rabbit studies.Our analysis confirms earlier findings that, on average over all compounds, rat and rabbit do not differ in sensitivity to developmental effects. There is substantial scatter in the correlation plots comparing rat and rabbit developmental N(L)OAELs, which is easily interpreted as species differences for individual compounds. However, for compounds tested twice in the same species, these N(L)OAELs may differ up to a factor of 25. Thus, potential interspecies differences in developmental N(L)OAEL will be overwhelmed by the reproducibility error, rendering the added value of a second species study questionable.As N(L)OAELs serve as point of departure (POD) for setting health-based guidance values in risk assessment, the large reproducibility error of N(L)OAELs should be taken into account by the introduction of an additional uncertainty factor. It is recommended to aim for reducing the reproducibility error by applying dose-response (BMD) analysis, optimize study designs and harmonize study protocols.

Effects of silver and zinc on tropical freshwater organisms: Implications on water quality guidelines and ecological risk assessment

Tropical freshwater ecosystems comprise valuable habitats and important biodiversity. There is an imperative need to build a framework for establishing appropriate water quality guidelines of chemical contaminants in order to safeguard freshwater ecosystems in the tropics. Silver (Ag) and zinc (Zn) are known to be toxic to freshwater organisms at elevated concentrations. However, toxicity data of tropical freshwater species for these metals are lacking. To address this issue, we first conducted standard acute toxicity tests of each of the metal using eight tropical freshwater species based on measured concentrations in test solutions. Subsequently, we tested the null hypothesis that there are no differences in species sensitivities towards Ag and Zn between tropical and temperate species by comparing their corresponding species sensitivity distributions (SSDs). The results of SSD comparisons indicated that tropical species were more acutely sensitive to their temperate counterparts to Ag, while temperate species were slightly more sensitive towards Zn. Temperate-to-tropic extrapolation factor of 5 was recommended for Ag, while acute-to-chronic ratios (ACRs) of 100 and 10 were advocated for Ag and Zn, respectively. Through comparison of taxon-specific SSDs, we observed that crustaceans were the most sensitive taxon to Ag and Zn, and thus suitable for toxicity testing and risk assessment. Based on our results, concentrations of 0.004 and 6.4 μg L−1 (at hardness of 50 mg L−1 CaCO3) were recommended as interim chronic predicted no-effect concentrations for Ag and Zn, respectively for protecting freshwater ecosystems in tropical regions.

Imidacloprid induces adverse effects on fish early life stages that are more severe in Japanese medaka (Oryzias latipes) than in zebrafish (Danio rerio)

Neonicotinoids are widely used insecticides that have frequently been found in freshwater with concentrations ranging from ng to μg/L. It is known that these compounds impact non-target invertebrates, such as bees and gammaridae, in terms of toxicity and behavior, but impacts and species differences on vertebrates such as fish are little explored. The aim of this study was to investigate and compare the effects of one widely used neonicotinoid, imidacloprid, on development and behavior of two fish model species: Zebrafish (Danio rerio) and Japanese medaka (Oryzias latipes). Fish were exposed for 5 (zebrafish) and 14 (medaka) days from 0.2 to 2000 μg/L imidacloprid by aqueous exposure. Survival, development, behavior and histological features were monitored and organism-internal concentrations and biotransformation products measured. Imidacloprid caused sublethal effects in both species but the effects were much stronger in medaka with deformities, lesions and reduced growth being the most prominent impacts. Due to the overall longer time of development, time-integrated exposure of medaka was about 2-fold higher compared to zebrafish, potentially accounting for parts of the sensitivity differences. Our results underline the importance of taking species sensitivity differences into account especially when considering that medaka responded at imidacloprid concentrations that have been measured in the environment.

Comment on Sensitivity Coefficients to Variation of Fundamental Constants

AbstractAtoms and molecules can serve as sensitive probes of a possible variation of the fine structure constant α and electron‐to‐proton mass ratio μ. Two types of sensitivity coefficients are often used to quantify and compare the sensitivity of different species to the variation of fundamental constants. The dimensionless coefficients K are related to the fractional sensitivity, while dimensional factors q are related to the absolute sensitivity. Here, several common errors and misconceptions regarding these coefficients that frequently appear in the literature are discussed.

Impacts of tropical forest disturbance on species vital rates.

Tropical forests are experiencing enormous threats from deforestation and habitat degradation. Much knowledge of the impacts of these land-use changes on tropical species comes from studies examining patterns of richness and abundance. Demographic vital rates (survival, reproduction, and movement) can also be affected by land-use change in a way that increases species vulnerability to extirpation, but in many cases these impacts may not be manifested in short-term changes in abundance or species richness. We conducted a literature review to assess current knowledge and research effort concerning how land-use change affects species vital rates in tropical forest vertebrates. We found a general paucity of empirical research on demography across taxa and regions, with some biases toward mammals and birds and land-use transitions, including fragmentation and agriculture. There is also considerable between-species variation in demographic responses to land-use change, which could reflect trait-based differences in species sensitivity, complex context dependencies (e.g., between-region variation), or inconsistency in methods used in studies. Efforts to improve understanding of anthropogenic impacts on species demography are underway, but there is a need for increased research effort to fill knowledge gaps in understudied tropical regions and taxa. The lack of information on demographic impacts of anthropogenic disturbance makes it difficult to draw definite conclusions about the magnitude of threats to tropical ecosystems under anthropogenic pressures. Thus, determining conservation priorities and improving conservation effectiveness remains a challenge.

Erythromycin sensitivity across different taxa of marine phytoplankton. A novel approach to sensitivity of microalgae and the evolutionary history of the 23S gene

Erythromycin has been recorded in coastal waters and could pose a severe threat to marine microbial life. Macrolides such as erythromycin may affect microalgae by inhibiting the pathways involved in protein synthesis. Toxicological testing of microalgae has proven to be a useful tool for the risk assessment of a substance affecting phytoplankton.Due to the controversial results concerning the sensitivity of microalgal species to erythromycin found in the literature, the goals of this work were, initially, to assess the erythromycin sensitivity of different species of marine microalgae from different and representative taxonomic groups; and, secondly, to examine whether the sensitivity to erythromycin could be explained by the differences in the phylogenetic evolution. We chose eight species: two green algae, four heterokonts, one haptophyte and one dinoflagellate, which were then exposed to erythromycin (0.1 to 10 mg L−1). Our results showed a wide range of sensitivities indicating that the biology of each species was primarily responsible for the variation observed. To test the second objective, we contrasted different ecotoxicological endpoints (growth, cellular properties and status of the photosynthetic apparatus) with the phylogenetic distribution [eukaryotic host (concatenated nuclear tree), evolutionary history of the chloroplast (16S tree), efficiency and repair of photosystem II (psbA tree), and the binding site of erythromycin (23S tree)] of the species.We found that the growth inhibition of microalgae as a toxicological endpoint was the endpoint best explained by the topology of the 23S rRNA gene tree when it was modelled following a non-stationary evolutionary process.