Search Results (13)

Understanding the motion behaviors of animals is crucial for unraveling the mechanisms underlying ethology across various domains, such as movement patterns, food detection, and defense strategies. In this study, we devised a simplified method enabling the movement of small animals to be tracked conveniently using high-resolution smartphone videos and freely available tracking software. Employing a laboratory video setup, we traced the swimming trajectory of the small copepod zooplankton Eodiaptomus japonicus, which has a body size of approximately 1 mm. From the tracked position data, we analyzed key motion parameters, including swimming distance, speed, and jump frequency. The results of our video analysis showed that adult female E. japonicus exhibited an average swimming speed of 9.8 mm s⁻¹, displaying a predominant cruising pattern with speeds of around 5.0 mm s⁻¹, punctuated by sporadic jumps, showcasing maximum instantaneous speeds reaching a remarkable 190.1 mm s⁻¹. Our successful tracking of the high-speed swimming copepod not only sheds light on its locomotion dynamics but also underscores the potential to refine this method to study the motion trajectories of diverse animal species. Full article

To assess the human impact on the water of Dayat Roumi Lake and to develop effective management strategies to protect and restore this vital ecosystem in the region, seasonal sampling was carried out at six stations distributed around the lake. During these sampling campaigns, 24 parameters were measured, including 20 trace elements. Results showed that measured levels of trace elements increased in the following order: Cd < Be < Tl < Co < Sb < Mo < Cu < Zn < Ni < V < Rb < Mn < As < Cr < Pb < Li < Ba < Se < Pd < Sr in the lake water and that these recorded values were lower than those recommended by the Moroccan standard and the World Health Organization, except for Pb and Se. Correlation analysis revealed two principal water-contamination sources: natural geological origins and anthropogenic inputs. In addition, the Water Quality Index WQI showed that the lake’s water quality is poor, and its use can be dangerous for human and animal health. Health risk assessment associated with prolonged exposure to trace elements in lake water revealed that the Hazard quotient HQ and Hazard index HI of certain elements, such as Tl, Sb, V, As, Cr, Pb, Li, and Se, are higher than 1 in adult and children, indicating a significant risk for people living near the lake. Children are particularly vulnerable, with higher levels of HQ and HI, and selenium poses a substantial risk to their health through ingestion and skin absorption. In both adults and children, the total risk of cancer due to metals is classified as follows: CI (Cr) > CI (Ni) > CI (As) > CI (Pb) > CI (Cd). The Cr presents the highest carcinogenic risk—by ingestion or dermal route—in both groups. The total risk for these five metals exceeds 1 × 10⁻⁴, indicating a danger for residents who drink or swim in the lake. Full article

This suspect case focuses on investigating the presence of halite (NaCl) crystals on the clothing of a deceased individual to determine whether they resulted from immersion in seawater or residual absorption after immersion (i.e., the crystals were left on the clothing after contact with the victim’s wet body). Thirteen clothing samples were collected from various garments worn by the victim and were subjected to optical stereomicroscopy, Scanning Electron Microscopy (SEM), coupled with Energy Dispersive Spectroscopy (EDS), and Simultaneous Thermal Analysis (STA). Optical stereomicroscopy revealed numerous white-colored, vitreous, and greasy luster microcrystals dispersed between fabric fibers, with higher concentrations observed near the hem seams and metal rivets. These microcrystals exhibited predominantly cubic and irregular morphologies. Additionally, sandy particles and organic elements, such as plant fragments and micro seashells, were detected, indicative of coastal environment exposure. SEM-EDS analysis confirmed the presence mainly of sodium and chlorine in stoichiometric ratios consistent with halite, with crystals exhibiting amorphous, needle-shaped, or cubic morphologies. Furthermore, STA analysis identified weight loss events attributed to organic decomposition and halite decomposition at high temperatures, corroborating SEM-EDS findings. The distribution and characteristics of halite crystals, along with other trace elements, support the hypothesis of immersion in seawater while wearing clothing. Specifically, the higher concentrations of halite crystals near thicker fabric portions and metal rivets suggest slower drying rates and longer evaporation times, indicative of immersion rather than residual absorption after swimming. This finding not only helps in determining the victim’s exposure to seawater but also establishes a methodology for distinguishing between different sources of halite residue on clothing. Overall, the comprehensive mineralogical characterization of halite crystals on clothing samples, using best practices of forensic mineralogy, provides valuable forensic insights related to the circumstances that led to the victim’s death. This approach aided investigators in reconstructing the sequence of events, enhancing the accuracy of forensic reconstructions. Moreover, this study contributes to the broader field of forensic geoscience by demonstrating the practical applications of mineralogical analysis in criminal investigations, potentially guiding future research and improving investigative techniques in similar cases. Full article

The Gansfontein palaeosurface (Fraserburg, Karoo, South Africa), which is correlated with the stratigraphic lowermost part of the continental Middle–Upper Permian Teekloof Formation, is revisited. This treasure trove of peculiar and exquisitely preserved sedimentary structures and invertebrate and vertebrate traces serves as a document of a set of fluvial paleoenvironments ranging from small ponds to marginal lacustrine and muddy riverine outer banks. It represents an isolated and relatively small “oasis” within the dominating sedimentary environments of the Teekloof Formation characterized by fine and medium-grained siliciclastics related to repeated higher-energy flooding events. The vertebrate traces include abundant therapsid trackways and, locally, tetrapod swimming traces. Tetrapod footprints show a very variable preservation in different areas of the palaeosurface, and it also changed based on the time of impression. Fish trails (Undichna) are relatively common. The invertebrate ichnofauna is comprised of abundant arthropod traces and horizontal burrows; however, the palaeosurface was not intersected by intense bioturbation. The occurrence of this scenario of abundant life reflects complex interaction among different tracemakers with the substrate and is evidence of a relatively quiet palaeoenvironment, which was suddenly submerged and sealed during a flooding event. Sedimentological and ichnological insights from such a palaeosurface, therefore, opens a rare window into Middle Permian ecosystems in southernmost Gondwana. Full article

Carbamate pesticides are a risk to human well-being, and pirimicarb is the most widely employed carbamate insecticide. This ongoing investigation aimed to reveal its toxicity on neurobehavioral and reproductive function. The study was carried out on male Wistar rats by assessment of behavioral changes via experiments, such as the forced swim test and the elevated plus maze; determination of oxidative stress (checking parameters such as catalase activity, etc.); measurement of cortisol and testosterone serum titers, and IL-1β levels in the plasma and brain; and evaluation of histopathological lesions that induced pirimicarb after 28 days of gavage, specifically in the brain and testis. Traces of pirimicarb were analyzed in tissue extracts using LCMS/MS. At the same time, the beneficial and protective effect of EamCE (Ephedra alata monjauzeana Crude Extract) were tested. The outcomes showed considerable anxiety and depressive status, with an evident increase in cortisol and IL-1β titers and an important decrease in oxidative enzymes and testosterone. Significant histological lesions were also recorded. In addition, the LCMS/MS analysis affirmed the accumulation of pirimicarb in organ tissue from rats force-fed with pirimicarb. Conversely, EamCE demonstrated outstanding potential as a preventive treatment, restoring cognitive and physical performance, boosting fertility, enhancing antioxidant and anti-inflammatory activities and preserving tissue integrity. We concluded that pirimicarb has critical deleterious impacts on health, affecting the neuroimmune-endocrine axis, and EamCE has a general euphoric and preventive effect. Full article

Surface current velocities of mesoscale eddies have a unique annular structure, which can inevitably influence surface wave properties and energy distribution. Sensitivity experiments of ideal mesoscale eddies on waves were carried out by the Simulating WAves Nearshore (SWAN) wave model to investigate these influences. In addition, China–France Oceanography SATellite Surface Wave Investigation and Monitoring (CFOSAT-SWIM) observational data of a large warm-cored eddy in the South China Sea (SCS) during the period of October–November 2019 were used to validate the influence of mesoscale eddies on waves. The results illustrated that mesoscale eddies can alter wave properties (wave height, period, and steepness) by 20–30%. Moreover, wave direction could also be modified by 30°–40°. The current effect on waves (CEW) was more noticeable with strong currents and weak winds, and was governed by wave age and the ratio of wave group velocity to current velocity. Wave spectra clearly indicated that current-induced variability in wave energy distribution happens on a spatial scale of 5–90 km (i.e., the sub- and mesoscales). Through comparing the difference of wave energy on both sides of an eddy perpendicular to the wave propagation direction in an eddy, a simple way to trace the footprints of waves on eddies was devised. Full article

The increasingly widespread use of engineered nanoparticles in medical, industrial, and food applications has raised concerns regarding their potential toxicity to humans and the environment. Silicon dioxide nanoparticles (SiO₂ NPs), which have relatively low direct toxicity, have been increasingly applied in both consumer products and biomedical applications, leading to significantly higher exposure for humans and the environment. We carried out a toxicity assessment of SiO₂ NPs using the common water flea D. magna by focusing on physiological and behavioral indicators such as heart rate, swimming performance, and growth. Exposure to SiO₂ NPs did not produce acute or chronic toxicity at limited concentrations (<100 μg/mL), but did have statistically significant negative effects on heart rate, swimming distance, and body size. The use of fluorescein isothiocyanate in a silica matrix allowed the tracing and visualization of clear SiO₂ NP accumulation in D. magna, which was confirmed by ICP-MS. Although exposure to SiO₂ NPs seemed to affect cardiac and swimming performance, such end-point experiments may be insufficient to fully understand the toxicity of these nanoparticles. However, the physiological and behavioral changes shown here suggest potential adverse effects on the aquatic environment by substances previously considered nontoxic. Full article

Trace Amine-Associated Receptor 1 (TAAR1) is a potential target for the treatment of depression and other CNS disorders. However, the precise functional roles of TAAR1 to the actions of clinically used antidepressants remains unclear. Herein, we addressed these issues employing the TAAR1 agonist, o-phenyl-iodotyramine (o-PIT), together with TAAR1-knockout (KO) mice. Irrespective of genotype, systemic administration of o-PIT led to a similar increase in mouse brain concentrations. Consistent with the observation of a high density of TAAR1 in the medial preoptic area, o-PIT-induced hypothermia was significantly reduced in TAAR1-KO mice. Furthermore, the inhibition of a prepulse inhibition response by o-PIT, as well as its induction of striatal tyrosine hydroxylase phosphorylation and elevation of extracellular DA in prefrontal cortex, were all reduced in TAAR1-KO compared to wildtype mice. O-PIT was active in both forced-swim and marble-burying tests, and its effects were significantly blunted in TAAR1-KO mice. Conversely, the actions on behaviour and prefrontal cortex dialysis of a broad suite of clinically used antidepressants were unaffected in TAAR1-KO mice. In conclusion, o-PIT is a useful tool for exploring the hypothermic and other functional antidepressant roles of TAAR1. By contrast, clinically used antidepressants do not require TAAR1 for expression of their antidepressant properties. Full article

Gravitaxis is one of the most important issues in the growth of microalgae in the water column; it determines how easily cells receive sunlight with a comfortable intensity that is below the damaging threshold. We quantitatively investigated and analyzed the gravitaxis and cell multiplication of Euglena gracilis using vertically placed microchambers containing a single cell. A temporal change in gravitaxis and cell multiplication was observed after transferring the cells to fresh culture medium for 9 days. We performed 29 individual experiments with 2.5 mm × 2.5 mm × 0.1 mm square microchambers and found that the cells showed positive, negative, and moderate gravitaxis in 8, 7, and 14 cases, respectively, after transferring to fresh culture medium. A common trend was observed for the temporal change in gravitaxis for the eight initially positive gravitaxis cases. The cells with initially positive gravitaxis showed a higher rate of cell multiplication than those with initially negative gravitaxis. We also discussed the gravitaxis mechanism of E. gracilis from the observed trend of gravitaxis change and swimming traces. In addition, bioconvection in a larger and thicker chamber was investigated at a millimeter scale and visualized. Full article

A proposal is described for an underwater sensor combining an acoustic device with an optical one to automatically size juvenile bluefin tuna from a ventral perspective. Acoustic and optical information is acquired when the tuna are swimming freely and the fish cross our combined sensor’s field of view. Image processing techniques are used to identify and classify fish traces in acoustic data (echogram), while the video frames are processed by fitting a deformable model of the fishes’ ventral silhouette. Finally, the fish are sized combining the processed acoustic and optical data, once the correspondence between the two kinds of data is verified. The proposed system is able to automatically give accurate measurements of the tuna’s Snout-Fork Length (SFL) and width. In comparison with our previously validated automatic sizing procedure with stereoscopic vision, this proposal improves the samples per hour of computing time by 7.2 times in a tank with 77 juveniles of Atlantic bluefin tuna (Thunnus thynnus), without compromising the accuracy of the measurements. This work validates the procedure for combining acoustic and optical data for fish sizing and is the first step towards an embedded sensor, whose electronics and processing capabilities should be optimized to be autonomous in terms of the power supply and to enable real-time processing. Full article

The present study investigated the occurrence of selected micropollutants, including emerging contaminants from a group of pharmaceuticals and personal care products (PPCPs) in water samples from swimming pool systems. The study area was selected based on the lack of available information regarding suspected contamination of swimming pool water by PPCPs. The variety and concentration of chemical compounds in these aquatic systems can be quite diversified, presenting a challenge in terms of both purification and quality control. Determination of PPCPs requires very sensitive analytical methods that make it possible to confirm the presence of tested compounds in a complex organic extract. In this field, gas chromatography-mass spectrometry (GC-MS) can be used. With this system, selected ion monitoring can be performed, which reduces the detection limits of the investigated analyte. This paper aims to present an analytical method and strategy that can be adapted to obtain information on the composition of water in swimming pool systems. The sample preparation methodology, including Solid Phase Extraction, has been developed for the trace determination of two pharmaceuticals—caffeine, carbamazepine—and one sunscreen constituent—benzophenone-3—in swimming pool water samples. Full article

Accurately assessing the toxicity of complex, environmentally relevant mixtures remains an important challenge in ecotoxicology. The goal was to identify biological effects after exposure to environmental water samples and to determine whether the observed effects could be explained by the waterborne metal mixture found in the samples. Zebrafish embryos were exposed to water samples of five different sites originating from two Flemish (Mol and Olen, Belgium) metal contaminated streams: “Scheppelijke Nete” (SN) and “Kneutersloop” (K), and a ditch (D), which is the contamination source of SN. Trace metal concentrations, and Na, K, Mg and Ca concentrations were measured using ICP-MS and were used to reconstitute site-specific water samples. We assessed whether the effects that were observed after exposure to environmental samples could be explained by metal mixture toxicity under standardized laboratory conditions. Exposure to “D” or “reconstituted D” water caused 100% mortality. SN and reconstituted SN water caused similar effects on hatching, swim bladder inflation, growth and swimming activity. A canonical discriminant analysis confirmed a high similarity between both exposure scenarios, indicating that the observed toxicity was indeed primarily caused by metals. The applied workflow could be a valuable approach to evaluate mixture toxicity that limits time and costs while maintaining biological relevance. Full article

Chemical interactions play a fundamental role in the ecology of marine foodwebs. Dimethyl sulfide (DMS) is a ubiquitous marine trace gas that acts as a bioactive compound by eliciting foraging behavior in a range of marine taxa including the copepod Temora longicornis. Production of DMS can rapidly increase following microzooplankton grazing on phytoplankton. Here, we investigated whether grazing-induced DMS elicits an increase in foraging behavior in the copepod Calanus helgolandicus. We developed a semi-automated method to quantify the effect of grazing-mediated DMS on the proportion of the time budget tethered females allocate towards slow swimming, typically associated with feeding. The pooled data showed no differences in the proportion of the 25 min time budget allocated towards slow swimming between high (23.6 ± 9.74%) and low (29.1 ± 18.33%) DMS treatments. However, there was a high degree of variability between behavioral responses of individual copepods. We discuss the need for more detailed species-specific studies of individual level responses of copepods to chemical signals at different spatial scales to improve our understanding of chemical interactions between copepods and their prey. Full article