Challenges in coupling atmospheric electricity with biological systems

Electric transportation and electroreception in hummingbird flower mites

Electric fields in terrestrial environments are used by caterpillars to detect their predators, as foraging cues by pollinators, and facilitate ballooning by spiders. This study shows that electric fields facilitate transportation and detection of hummingbirds in a guild of tropical phoretic mites. Hummingbird flower mites feed on nectar and pollen and complete their life cycle inside flowers. Mites colonize new flowers by hitching rides on hummingbird beaks. Flower mites emerge from hummingbird nostrils and disembark when the beak touches a flower. We tested whether flower mites are attracted to unmodulated electrostatic, or to modulated electric fields with amplitudes and frequencies in the range of those previously reported for hummingbirds. In a laboratory setup, mites were only attracted to modulated electric fields. In a choice experiment between positive or negative polarities, mites almost instantaneously chose positive charges, but only when the field was modulated. Mites display questing behavior, moving their front legs toward an electrostatic source. In experiments where we removed one or both front leg tarsi, we show that modulated fields are detected by sensory structures present in the front legs. We also show that flower mites use electrostatic attraction to bridge the gap to the beaks of hummingbirds, for a few milliseconds becoming one of the fastest terrestrial organisms. Our results confirm that hummingbird flower mites evolved an additional sensory modality - electroreception - to quickly detect hummingbirds and use electrostatics to facilitate transportation onto their hosts.

Aerial electroreception

Electroreception is the capacity of living organisms to detect the presence of electricity, usually studied in the aquatic environment. Electroreception in air, however, has received much less attention until relatively recently. Understanding how and why aerial electroreception may work requires a multidisciplinary framework, anchored in both the physics of static electricity and the ecology of sensory biology. In essence, the novel challenge arises from the fact that air is a much less conductive medium than water. Yet, recent research on terrestrial arthropods, including bees, flies, spiders, worms and caterpillars, has unveiled sensitivity to electric fields in different sensory ecological contexts. For each aerial organism considered thus far, filiform hairs and/or the antennae have been proposed to be the specialised sensory structures enabling detection based on both empirical and theoretical evidence. This newfound sensory modality reveals a previously unrecognised source of information, a new informational ecological niche integral to diverse life histories and navigational abilities, which remarkably involves animals, plants and atmospheric electricity (Figure 1). Understanding aerial electroreception in arthropods opens avenues for exploring their behaviour and ecology in diverse environments and sheds light on the evolution of sensory adaptations in terrestrial organisms. Because, as is known today, humans are not sensitive to weak electric fields, challenges arise in our comprehension of the elusive and discrete nature of aerial electric fields, and how they could be detected and used by terrestrial organisms.

Prey can detect predators via electroreception in air

Predators and prey benefit from detecting sensory cues of each other's presence. As they move through their environment, terrestrial animals accumulate electrostatic charge. Because electric charges exert forces at a distance, a prey animal could conceivably sense electrical forces to detect an approaching predator. Here, we report such a case of a terrestrial animal detecting its predators by electroreception. We show that predatory wasps are charged, thus emit electric fields, and that caterpillars respond to such fields with defensive behaviors. Furthermore, the mechanosensory setae of caterpillars are deflected by these electrostatic forces and are tuned to the wingbeat frequency of their insect predators. This ability unveils a dimension of the sensory interactions between prey and predators and is likely widespread among terrestrial animals.

Overhead AC powerlines and rain can alter the electric charge distribution on airborne particles - Implications for aerosol dispersion and lung deposition

Corona ions from high voltage power lines (HVPL) can increase electrostatic charge on airborne pollutant particulates, possibly increasing received dose upon inhalation. To investigate the potential increased risk of childhood leukemia associated with residence near alternating current (AC) HVPL, we measured the particle charge state and atmospheric electricity parameters upwind, downwind and away from HVPL. Although we observed noticeable charge state alteration from background levels, most HVPL do not significantly increase charge magnitude. Particular HVPL types are shown to have most effect, increasing net charge to 15 times that at background. However, the magnitude of charge alteration during rainfall is comparable with the most extreme HVPL measurement. On current evidence, based on the current adult lung model, we suggest that although charge is sometimes enhanced to levels which may alter atmospheric particle dynamics, increased lung deposition is unlikely.

The decrease in diurnal oxygen production in Elodea under the influence of high geomagnetic variability: the role of light, temperature and atmospheric pressure

Epidemiological studies have indicated adverse effects of geomagnetic disturbance on human health, including increased mortality. There is evidence from plant and animal studies that help to elucidate this interaction. This study tests the hypothesis that geomagnetic disturbance affects living systems, by modifying the metabolic process of photosynthesis, in the natural environment.Continuous 24-h measurements of dissolved oxygen in flasks containing Holtfreiter's solution and strands of healthy Elodea were recorded from May 1996, until September 1998, in an electromagnetically quiet, purpose built, garden shed environment, without mains electricity. Sensormeter recordings of oxygen, light, temperature and air pressure were uploaded weekly to a PC. The hourly total geomagnetic field measurements were obtained from the nearest observatory.Significant decrease in oxygen (diurnal volume of oxygen divided by plant mass and diurnal light), (O/WL), was found on days of high geomagnetic field variability throughout 11 recorded months of the year 1997. This result was independent of temperature and atmospheric pressure. No significant decrease in O/WL during high geomagnetic variability was found for the 7 months recorded in 1996. The 1996 and 1997 data both showed a significant decrease in the diurnal time lag between peak light and peak oxygen for diurnal high geomagnetic variability compared with low geomagnetic variability. Cross correlation analysis for 1997 and 1998 data showed a decrease in positive correlation of oxygen with light in high geomagnetic variability, compared with low geomagnetic variability, and increased positive correlation with the geomagnetic field instead. These experiments support a hypothesis of high geomagnetic field variability as a weak zeitgeber, and a metabolic depressant for photosynthetic oxygen production in plants.

Grounding (earthing) as related to electromagnetic hygiene: An integrative review

There are a growing number of studies investigating how grounding (earthing) the body may benefit biological performance and aid the treatment of non-communicable diseases. Research also indicates how biological grounding initiatives can sometimes be compromised, or inappropriate, and the need to take additional factors into account as potential contributory factors, or confounders, to expected results. It is proposed that expanding electromagnetic hygiene measures beyond biological grounding alone may help reduce spread of communicable diseases, incidence of respiratory conditions, neurodegenerative disease and all-cause mortality. Identifying potential synergies that exist could enable multilevel interventions to further increase the efficacy of measures. It is hoped that this review will help act as a catalyst to inspire and inform multi-disciplinary research within these topic areas, best practices and policies to help drive medical innovation, reduce health burdens, improve bioelectromagnetic-based therapies, and influence the general design of the built environment and next-generation technologies.

Observed electric charge of insect swarms and their contribution to atmospheric electricity

The atmosphere hosts multiple sources of electric charge that influence critical processes such as the aggregation of droplets and the removal of dust and aerosols. This is evident in the variability of the atmospheric electric field. Whereas these electric fields are known to respond to physical and geological processes, the effect of biotic sources of charge has not hitherto been considered. Here, we combine theoretical and empirical evidence to demonstrate that honeybee swarms directly contribute to atmospheric electricity, in proportion to the swarm density. We provide a quantitative assessment of this finding, by comparing the electrical contribution of various swarming insect species with common abiotic sources of charge. This reveals that the charge contribution of some insect swarms will be comparable with that of meteorologically induced variations. The observed transport of charge by insects therefore demonstrates an unexplored role of biogenic space charge for physical and ecological processes in the atmosphere.

Synthetic fertilizers alter floral biophysical cues and bumblebee foraging behavior

The use of agrochemicals is increasingly recognized as interfering with pollination services due to its detrimental effects on pollinators. Compared to the relatively well-studied chemical toxicity of agrochemicals, little is known on how they influence various biophysical floral cues that are used by pollinating insects to identify floral rewards. Here, we show that widely used horticultural and agricultural synthetic fertilizers affect bumblebee foraging behavior by altering a complex set of interlinked biophysical properties of the flower. We provide empirical and model-based evidence that synthetic fertilizers recurrently alter the magnitude and dynamics of floral electrical cues, and that similar responses can be observed with the neonicotinoid pesticide imidacloprid. We show that biophysical responses interact in modifying floral electric fields and that such changes reduce bumblebee foraging, reflecting a perturbation in the sensory events experienced by bees during flower visitation. This unveils a previously unappreciated anthropogenic interference elicited by agrochemicals within the electric landscape that is likely relevant for a wide range of chemicals and organisms that rely on naturally occurring electric fields.

The effect of DC electric field on the elongation growth, proton extrusion and membrane potential of Zea mays L. coleoptile cells; a laboratory study

BACKGROUND

In this study, we investigated the effect of an electric field, with an intensity similar to that of the Earth's field, on plant cells growth. The molecular mechanism underlying this effect remains unclear.

RESULTS

It was found that the electric field, depending on the applied voltage, its duration and the polarization of the maize seedlings, stimulated or inhibited the growth of the seedling organs (root, mesocotyl and coleoptile). Moreover, it was also noticed that the gravitropic response of maize seedlings was inhibited at all voltages studied. Simultaneous measurements of growth and external medium pH show that auxin(IAA, indole-3-acetic acid)- and fusicoccin(FC)-induced elongation growth and proton extrusion of maize coleoptile segments were significantly inhibited at higher voltages. The ionic current flowing through the single coleoptile segment during voltage application was 1.7-fold lower in segments treated with cation channel blocker tetraethylammonium chloride (TEA-Cl) and 1.4-fold higher with IAA compared to the control. The electrophysiological experiments show that the electric field caused the depolarization of the membrane potential of parenchymal coleoptile cells, which was not reversible over 120 min.

CONCLUSION

It is suggested that a DC electric field inhibits the plasma membrane H⁺ pump activity and K⁺ uptake through voltage-dependent, inwardly rectifying ZMK1 channels (Zea mays K⁺ channel 1). The data presented here are discussed, taking into account the "acid growth hypothesis" of the auxin action and the mechanism of gravitropic response induction.

The ecology of electricity and electroreception

Electricity, the interaction between electrically charged objects, is widely known to be fundamental to the functioning of living systems. However, this appreciation has largely been restricted to the scale of atoms, molecules, and cells. By contrast, the role of electricity at the ecological scale has historically been largely neglected, characterised by punctuated islands of research infrequently connected to one another. Recently, however, an understanding of the ubiquity of electrical forces within the natural environment has begun to grow, along with a realisation of the multitude of ecological interactions that these forces may influence. Herein, we provide the first comprehensive collation and synthesis of research in this emerging field of electric ecology. This includes assessments of the role electricity plays in the natural ecology of predator-prey interactions, pollination, and animal dispersal, among many others, as well as the impact of anthropogenic activity on these systems. A detailed introduction to the ecology and physiology of electroreception - the biological detection of ecologically relevant electric fields - is also provided. Further to this, we suggest avenues for future research that show particular promise, most notably those investigating the recently discovered sense of aerial electroreception.

Heliogeophysical Conditions in Moscow during the Covid-19 Pandemic

In this paper we consider the effect of heliogeophysical activity on the COVID-19 epidemic associated with the spread of the SARS-CoV-2 coronavirus in Moscow. An analysis of official data on the course of the pandemic has provided evidence of the effect of heliogeophysical activity on the spread of an infectious disease. The pandemic arose during the winter when solar activity was minimal and ultraviolet radiation was at its lowest. The study showed a significant relation between the infectious process and geomagnetic activity: periods of outbreaks in the number of infections and deaths correlated with periods of a decrease in geomagnetic activity lasting several months. The impact of magnetospheric storms and substorms on the human body during a pandemic is also considered. It is shown that, during the minimum of solar activity during periods of geomagnetic disturbances lasting from one to several days, both the number of infections and the number of deaths additionally and statistically significantly increase. Evidence of a direct or indirect effect of solar activity on the occurrence of outbreaks of infectious diseases is important from the viewpoint of understanding the emergence and development of epidemics.

WWLLN Hot and Cold-Spots of Lightning Activity and Their Relation to Climate in an Extended Central America Region 2012–2020

Lightning activity has been recognized to have, historically, social and environmental consequences around the globe. This work analyzes the space-time distribution of lightning-densities (D) in an extended Central America region (ECA). World Wide Lightning Location Network data was analyzed to link D with dominant climate patterns over the ECA for 2012–2020. D associated with cold surges entering the tropics dominate during boreal winter. The highest D (hot-spots) was found to agree well with previously known sites, such as the “Catatumbo” in Venezuela; however, D was lower here due to different detection efficiencies. Previously reported hot-spots showed strong continental signals in CA; however, in this work, they were over the oceans near to coastlines, especially in the eastern tropical Pacific (ETP). Most cold-spots, implying a minimum of vulnerability to human impacts and to some industries, were situated in the Caribbean Sea side of Central America. The Mid-Summer-Drought and the Caribbean-Low-Level-Jet (CLLJ) markedly reduced the D during July-August. The CLLJ in the central CS and across the Yucatan and the southern Gulf of Mexico acts as a lid inhibiting convection due to its strong vertical shear during the boreal summer. The CLLJ vertical wind-shear and its extension to the Gulf of Papagayo also diminished convection and considerably decreased the D over a region extending westward into the ETP for at least 400–450 km. A simple physical mechanism to account for the coupling between the CLLJ, the MSD, and lightning activity is proposed for the latter region.

Bumblebee electric charge stimulates floral volatile emissions in Petunia integrifolia but not in Antirrhinum majus

The timing of volatile organic compound (VOC) emission by flowering plants often coincides with pollinator foraging activity. Volatile emission is often considered to be paced by environmental variables, such as light intensity, and/or by circadian rhythmicity. The question arises as to what extent pollinators themselves provide information about their presence, in keeping with their long co-evolution with flowering plants. Bumblebees are electrically charged and provide electrical stimulation when visiting plants, as measured via the depolarisation of electric potential in the stem of flowers. Here we test the hypothesis that the electric charge of foraging bumblebees increases the floral volatile emissions of bee pollinated plants. We investigate the change in VOC emissions of two bee-pollinated plants (Petunia integrifolia and Antirrhinum majus) exposed to the electric charge typical of foraging bumblebees. P. integrifolia slightly increases its emissions of a behaviorally and physiologically active compound in response to visits by foraging bumblebees, presenting on average 121 pC of electric charge. We show that for P. integrifolia, strong electrical stimulation (600-700 pC) promotes increased volatile emissions, but this is not found when using weaker electrical charges more representative of flying pollinators (100 pC). Floral volatile emissions of A. majus were not affected by either strong (600-700 pC) or weak electric charges (100 pC). This study opens a new area of research whereby the electrical charge of flying insects may provide information to plants on the presence and phenology of their pollinators. As a form of electroreception, this sensory process would bear adaptive value, enabling plants to better ensure that their attractive chemical messages are released when a potential recipient is present.

The Possible Effect of Space Weather Factors on Various Physiological Systems of the Human Organism

A systematic review of heliobiological studies of the last 25 years devoted to the study of the potential influence of space weather factors on human health and well-being was carried out. We proposed three criteria (coordinates), according to which the work on solar–biospheric relations was systematized: the time scale of data sampling (years, days, hours, minutes); the level of organization of the biological system under study (population, group, individual, body system); and the degree of system response (norm, adaptation, failure of adaptation (illness), disaster (death)). This systematic review demonstrates that three parameters mentioned above are closely related in the existing heliobiological studies: the larger the selected time scale, the higher the level of estimated biological system organization and the stronger the potential response degree is. The long-term studies are devoted to the possible influence of solar activity on population disasters, i.e., significant increases in morbidity and mortality. On a daily scale, a probable effect of geomagnetic storms and other space weather events on short-term local outbreaks of morbidity is shown as well as on cases of deterioration in people functional state. On an intraday scale, in the regular functioning mode, the heart and brain rhythms of healthy people turn to be synchronized with geomagnetic field variations in some frequency ranges, which apparently is the necessary organism’s existence element. The applicability of different space weather indices at different data sampling rates, the need to take into account the contribution of meteorological factors, and the prospects for an individual approach in heliobiology are discussed. The modern important results of experiments on modeling the action of magnetic storms in laboratory conditions and the substantiation of possible theoreical mechanisms are described. These results provide an experimental and theoretical basis for studies of possible connections of space weather and human health.

Glossary on atmospheric electricity and its effects on biology

There is an increasing interest to study the interactions between atmospheric electrical parameters and living organisms at multiple scales. So far, relatively few studies have been published that focus on possible biological effects of atmospheric electric and magnetic fields. To foster future work in this area of multidisciplinary research, here we present a glossary of relevant terms. Its main purpose is to facilitate the process of learning and communication among the different scientific disciplines working on this topic. While some definitions come from existing sources, other concepts have been re-defined to better reflect the existing and emerging scientific needs of this multidisciplinary and transdisciplinary area of research.

Toward the creation of an ontology for the coupling of atmospheric electricity with biological systems

Atmospheric electric fields (AEFs) are produced by both natural processes and electrical infrastructure and are increasingly recognized to influence and interfere with various organisms and biological processes, including human well-being. Atmospheric electric fields, in particular electromagnetic fields (EMFs), currently attract a lot of scientific attention due to emerging technologies such as 5G and satellite internet. However, a broader retrospective analysis of available data for both natural and artificial AEFs and EMFs is hampered due to a lack of a semantic approach, preventing data sharing and advancing our understanding of its intrinsic links. Therefore, here we create an ontology (ENET_Ont) for existing (big) data on AEFs within the context of biological systems that is derived from different disciplines that are distributed over many databases. Establishing an environment for data sharing provided by the proposed ontology approach will increase the value of existing data and facilitate reusability for other communities, especially those focusing on public health, ecology, environmental health, biology, climatology as well as bioinformatics.