Quantitative analysis of the morphing wing mechanism of raptors: Bionic design of Falco Peregrinus wing skeleton.

The wing is one of the most important parts of a bird's locomotor system and is the inspiration origination for bionic wing design. During wing motions, the wing shape is closely related to the rotation angles of wing bones. Therefore, the research on the law of bone movement in the process of wing movement can be good guidance for the design of the bionic morphing wing. In this paper, the skeletal posture of the peregrine falcon wing during the extension/flexion is studied to obtain critical data on skeletal posture. Since an elbow joint and a wrist joint rotate correlatively to drive a wing to flex/extend, the wing skeleton is simplified as a four-bar mechanism in this paper. The degree of reproduction of wing skeleton postures was quantitatively analyzed using the four-bar mechanism model, and the bionic wing skeleton was designed. It is found that the wing motions have been reproduced with high precision.

Efficient cluster-based routing protocol for wireless sensor networks by using collaborative-inspired Harris Hawk optimization and fuzzy logic.

In wireless sensor networks, the implementation of clustering and routing protocols has been crucial in prolonging the network's operational duration by conserving energy. However, the challenge persists in efficiently optimizing energy usage to maximize the network's longevity. This paper presents CHHFO, a new protocol that combines a fuzzy logic system with the collaborative Harris Hawks optimization algorithm to enhance the lifetime of networks. The fuzzy logic system utilizes descriptors like remaining energy, distance from the base station, and the number of neighboring nodes to designate each cluster head and establish optimal clusters, thereby alleviating potential hot spots. Moreover, the Collaborative Harris Hawks Optimization algorithm employs an inventive coding mechanism to choose the optimal relay cluster head for data transmission. According to the results, the network throughput, HHOCFR is 8.76%, 11.73%, 8.64% higher than HHO-UCRA, IHHO-F, and EFCR. In addition, he energy consumption of HHOCFR is lower than HHO-UCRA, IHHO-F, and EFCR by 0.88%, 39.79%, 34.25%, respectively.

The use of social information in vulture flight decisions.

Animals rely on a balance of personal and social information to decide when and where to move next in order to access a desired resource. The benefits from cueing on conspecifics to reduce uncertainty about resource availability can be rapidly overcome by the risks of within-group competition, often exacerbated toward low-ranked individuals. Being obligate soarers, relying on thermal updraughts to search for carcasses around which competition can be fierce, vultures represent ideal models to investigate the balance between personal and social information during foraging movements. Linking dominance hierarchy, social affinities and meteorological conditions to movement decisions of eight captive vultures, Gyps spp., released for free flights in natural soaring conditions, we found that they relied on social information (i.e. other vultures using/having used the thermals) to find the next thermal updraught, especially in unfavourable flight conditions. Low-ranked individuals were more likely to disregard social cues when deciding where to go next, possibly to minimize the competitive risk of social aggregation. These results exemplify the architecture of decision-making during flight in social birds. It suggests that the environmental context, the context of risk and the social system as a whole calibrate the balance between personal and social information use.

Detection of a novel genotype of Chlamydia buteonis in falcons from the Emirates.

Chlamydiaceae are a family of obligate intracellular bacterial pathogens that affect both humans and animals. Recently, a new species named Chlamydia (C.) buteonis was isolated from hawks. In this study, we aimed to investigate the prevalence of Chlamydiaceae in 60 falcons that underwent a routine health check at a specialized clinic in Dubai, United Arab Emirates. Using real-time PCR, we analyzed cloacal and tracheal swabs from these birds and found that 39 of them tested positive for Chlamydiaceae. Subsequent real-time PCR assays specific for C. psittaci, C. abortus, C. avium, and C. gallinacea yielded negative results, while testing positive for C. buteonis. Analysis of ompA and MLST sequences indicated a highly conserved group of strains within this set of samples, but with sequences distinct from the C. buteonis RSHA reference strains and other C. buteonis strains isolated from hawks in the United States. Two strains were further isolated by cell culture and sequenced using whole-genome sequencing, confirming the clustering of these falcon strains within the C. buteonis species, but in a separate clade from the previously identified hawk strains. We also developed a SNP-based PCR-HRM assay to distinguish between these different genotypes. Overall, our findings suggest a high prevalence of C. buteonis in falcons in Dubai and highlight the importance of monitoring this pathogen in birds of prey.

Efficacy of an inflatable deterrent for reducing New World vulture human-wildlife conflict.

Increasing urbanization coupled with spatial expansion and numerical increase of New World vulture populations has engendered a rise in human-vulture conflict, creating a need for effective tools to mitigate vulture-related damage. Visual frightening devices that mimic the presence of human or other predators can be employed in human-vulture conflict scenarios to increase perceived risk by the pest species, thereby eliciting an antipredator behavioral response, such as fleeing. One visual frightening device, inflatable scarecrows, recently proved effective at reducing passerine attendance at feral swine feeders, but their effectiveness when directed at other species and conflict scenarios has varied. Our primary objective was to evaluate an inflatable deterrent for reducing the number of black (Coragyps atratus) and turkey vultures (Cathartes aura) present (hereafter abundance) at 13 human-vulture conflict sites throughout the southeastern United States. We predicted that vulture abundance would be substantially reduced when inflatable deterrents were deployed. Because we suspected other factors might also influence vulture site abundance, we also examined the exploratory variables of weather, site size (area), and vulture tolerance to human approach in relation to vulture site abundance using a model selection approach. Black vulture site abundance was more pervasive than turkey vultures, occurring at all sites and accounting for 85% of daily vulture counts (10.78 ± 0.52 vultures/site/day) whereas turkey vultures were only present at 62% of sites (2.12 ± 0.21). Across all sites, inflatable scarecrows were effective at reducing vulture abundance by 82% during the seventeen-day treatment period when deterrents were deployed (3.50 ± 0.20), but only a 48% reduction during the twenty-one-day post-treatment phase (15.34 ± 1.39) was observed. Site size and weather did not influence tool effectiveness. Human tolerance at sites, as determined by vulture flight initiation distance, was influential, with tool effectiveness being reduced at sites where local human tolerance was high. We recommend inflatable scarecrows as a tool to reduce vulture-wildlife conflict to private property and recreation at sites where the conflict is spatially restricted (e.g., parking lot or recreation area), conducive to scarecrow deployment (e.g., flat stable surfaces), and where vulture site human tolerance is low to moderate.

THE IMPACT OF SUPPLEMENTARY FEEDING OF PIG CARCASSES ON PLASMA VITAMIN E CONCENTRATIONS IN CAPTIVE CAPE VULTURES (GYPS COPROTHERES).

With vulture population numbers on the decline globally, many countries resort to supplementary feeding to maintain colony health. Despite what is perceived as adequate feeding in South Africa, colonies are still characterized by poor breeding success. One reason could be that supplementary sites fail to meet micronutrient needs of birds. With results from zoological gardens indicating that some carcasses are low in their vitamin E concentrations, vitamin deficiencies may be an underlying problem. For this study it was determined if the feeding of whole pig carcasses, a common food item, could have a negative effect on plasma vitamin E concentrations in a captive colony. Plasma vitamin E concentrations were 7.38 ± 2.92 and 4.51 ± 1.24 after feeding whole pig carcasses (n = 14). Behaviorally, the birds also avoided the viscera and fat when feeding. Reasons for their low vitamin E concentrations could have resulted from the birds consuming only the pork meat, which is known to be low in vitamin E, or from natural peroxidation because of the high fat content of the carcasses. The study thus highlights the need for further research to ascertain the impact of feeding pig carcasses on wild vultures feeding routinely at supplementary feeding sites and also for considerations towards vitamin E supplementation.

First species record of Strigea falconis Szidat, 1928 (Trematoda, Strigeidae) from gyrfalcon Falco rusticolus in Iceland-pros and cons of a complex life cycle.

Strigea falconis is a common parasite of birds of prey and owls widely distributed in the Holarctic. We aimed to characterise S. falconis from Iceland via integrative taxonomic approach and to contribute to the understanding of its circulation in the Holarctic. We recovered adult S. falconis from two gyrfalcons (Falco rusticolus) collected in 2011 and 2012 in Iceland (Reykjanes Peninsula, Westfjords) and characterised them by morphological and molecular genetic (D2 of rDNA, cox1, ND1 of the mDNA) methods. We provide the first species record of S. falconis in Iceland which to the best of our knowledge is its northernmost distributional range. The presence of S. falconis in Iceland is surprising, as there are no suitable intermediate hosts allowing completion of its life cycle. Gyrfalcons are fully sedentary in Iceland; thus, the only plausible explanation is that they acquired their infection by preying upon migratory birds arriving from Europe. Our data indicate that the most likely candidates are Anseriformes and Charadriiformes. Also, we corroborate the wide geographical distribution of S. falconis, as we found a high degree of similarity between our haplotypes and sequences of mesocercariae from frogs in France and of a metacercaria from Turdus naumanni in Japan, and adults from Buteo buteo and Circus aeruginosus from the Czech Republic. The case of Strigea falconis shows the advantages of a complex life cycle and also depicts its pitfalls when a parasite is introduced to a new area with no suitable intermediate hosts. In Iceland, gyrfalcons are apparently dead-end hosts for S. falconis.

Cultural attitudes and human pressure towards vultures around the Comoé National Park, Côte d'Ivoire (West Africa).

BACKGROUND: Populations of vultures in Africa have experienced a rapid decline over recent decades, with some species suffering losses of more than 90%. Various forms of human pressures have been identified as the causes of this decline. However, very little is known about the complex interaction between cultural practises, traditional medicine and the vultures' natural environment. The purpose of this study was to analyse human pressures on vultures in relation with cultural attitudes such as their demand for magico-traditional medicine in Côte d'Ivoire, around the Comoé National Park (CNP), one of the last major refuges of these organisms in West Africa. METHODS: Eleven surrounding villages were visited to carry out ethno-ornithology surveys. One hundred and ten people were interviewed, at a rate of ten people per village, using a semi-structured questionnaire and informal discussions. RESULTS: The findings showed that vultures are still being seen both in and around the CNP. The most common species indicated to be observed and indicated by the interviewees were the Hooded Vulture (Necrosyrtes monachus) and the White-headed Vulture (Trigonoceps occipitalis). Nevertheless, 98.2% of the interviewees indicated having observed a decrease in the abundance of vultures over the last few years in the study area, as well as a decline in the number of sightings of these organisms. Interviewees attributed this scarcity of vultures to (1) the limited availability of food resources, (2) pesticide and tobacco poisoning, (3) hunting, (4) rapid population growth, (5) annual bushfires and (6) habitat loss. The uses of the vulture or parts of vultures by the populations surrounding the CNP (traditional medicine, mystic practises, consumption as food, cultural heritage) were also highlighted as real threats to these organisms. And the vulture parts commonly used in this area are: feathers, legs, head, heart, stomach, brain and excrement. The Hooded Vulture (Necrosyrtes monachus) appears to be the most sought-after species and the most widely used for these practises in the study area. CONCLUSION: Appropriate conservation and communication initiatives are required to ensure the survival of these raptors, crucial for ecosystem well-being, while also ensuring a respect of cultural practises.

Black Vulture (Coragyps atratus) feathers as bioindicators of exposure to metals and metalloids contamination in urban, semi-urban, and rural areas from Campeche state, Mexico.

Landfills are sources of soil, water, and air pollution due to the release of toxic compounds such as metals and metalloids. In both tropical and temperate environments, scavenger birds such as the Black Vulture (Coragyps atratus) that have learned to use these sites as a feeding area are probably exposed to metals, metalloids and other "persistent bioaccumulative toxic substances (PBTs)" released in open dumpsite (OD) and sanitary landfill (SL). The objective of this study is to evaluate the presence and distribution of toxic metals (Al, Sn, Hg, Cu, Pb, Cd, Cr) and As in OD and SL from urban, semi-urban and rural localities in Campeche, México, using molting feathers of C. atratus as bioindicators. A total of 125 Black Vulture primary and secondary wing feathers were collected from OD and SL. Metals were determined by voltammetry through acid digestion. The highest levels of metals occurred in landfills in urban, semi-urban, and rural localities. The elements with the highest concentrations were Al, with an average of 35.67 ± 33.51 µg g-1 from rural environments, and As, with 16.20 ± 30.06 µg g-1 from the urban localities. Mercury was the only element that had a very homogeneous distribution between the three environments we studied. In general, Pb, Hg, Cu and Cd were the elements that presented the lowest concentrations with 0.32 ± 0.35, 0.16 ± 0.22, 0.14 ± 0.31 and 0.06 ± 0.10 µg g-1, respectively regardless of any particular location or environment. Black Vultures from dumpsites are good bioindicators of what humans consume in urban, semi-urban, and rural environments. However, the conservation of vultures is of great importance since these scavenger birds perform ecosystem services by feeding on decomposing organic material.

Trace elements and heavy metals in black vultures (Coragyps atratus) and turkey vultures (Cathartes aura) in the southeastern United States.

Many vulture species worldwide are declining at alarming rates due to a variety of anthropogenic causes, including exposure to pollutants and pharmaceuticals through consumption of contaminated carrion. However, little is known about the extent to which vultures are exposed to various contaminants as well as toxicity thresholds for trace elements and heavy metals. Our objective was to quantify levels of trace elements and heavy metals within black vulture (Coragyps atratus) and turkey vulture (Cathartes aura) tissues to determine the extent to which populations in the Southeastern United States are exposed to carrion that contains high levels of contaminants. We collected 34 black vulture liver samples and examined differences in trace element and heavy metal concentrations between sexes and age classes (adult and juvenile). Further, we collected 81 blood and 42 feather samples from additional black and turkey vultures and compared differences between species and age classes. We found similar element concentrations between juvenile and adult black vultures with the exception of Cu, where levels were higher in juveniles compared to adults. However, we did observe substantial differences in element concentrations between species for both blood and feather samples, with black vultures generally having higher concentrations of most elements. Our data revealed higher element levels in both species compared to toxicity thresholds found in other bird of prey species, such as blood and liver toxicity threshold suggestions for Pb poisoning in Falconiformes. Further, while average contaminant levels were generally low, extreme outliers were observed for some elements, including Pb, suggesting some individuals were exposed to high levels of potentially toxic elements. More research is needed to better understand contaminant exposure in black and turkey vultures across a broader geographic region, as well as elucidate toxicity thresholds and non-lethal impacts of contaminant exposure in these species.

Falcon gut microbiota is shaped by diet and enriched in Salmonella.

The gut microbiome is increasingly being appreciated as a master regulator of animal health. However, avian gut microbiome studies commonly focus on birds of economic importance and the gut microbiomes of raptors remain underexplored. Here we examine the gut microbiota of 29 captive falcons-raptors of historic importance-in the context of avian evolution by sequencing the V4 region of the 16S rRNA gene. Our results reveal that evolutionary histories and diet are significantly associated with avian gut microbiota in general, whereas diet plays a major role in shaping the falcon gut microbiota. Multiple analyses revealed that gut microbial diversity, composition, and relative abundance of key diet-discriminating bacterial genera in the falcon gut closely resemble those of carnivorous raptors rather than those of their closest phylogenetic relatives. Furthermore, the falcon microbiota is dominated by Firmicutes and contains Salmonella at appreciable levels. Salmonella presence was associated with altered functional capacity of the falcon gut microbiota as its abundance is associated with depletion of multiple predicted metabolic pathways involved in protein mass buildup, muscle maintenance, and enrichment of antimicrobial compound degradation, thus increasing the pathogenic potential of the falcon gut. Our results point to the necessity of screening for Salmonella and other human pathogens in captive birds to safeguard both the health of falcons and individuals who come in contact with these birds.

Behavioral interactions are modulated by facilitation along a heterotrophic succession.

Competition and facilitation drive ecological succession but are often hard to quantify. In this sense, behavioral data may be a key tool to analyze interaction networks, providing insights into temporal trends in facilitation and competition processes within animal heterotrophic succession. Here, we perform the first in-depth analysis of the factors driving temporal dynamics of carcass consumption by analyzing behavioral patterns (i.e., interactions) and community dynamics metrics (i.e., species richness, abundance, turnover, and diversity) in a Neotropical scavenger guild. For this purpose, we monitored goat carcasses using automatic cameras. From 573 reviewed videos, we registered 1784 intraspecific and 624 interspecific interactions, using intraspecific and interspecific aggressions (n = 2048) as a behavioral proxy of competition intensity. Our results show that resource availability shapes behavioral interactions between vultures, with a specific effect of the different species on behavioral and competition dynamics, showing the existence of a hierarchy between species. Furthermore, behavioral processes linked to carcass opening tended to be facilitative, related to moments of higher tolerance (i.e., lower aggressiveness), thus reducing competition intensity and also affecting community structure and dynamics. This novel framework demonstrates complex ephemeral successional processes characterized by a fluctuation in facilitation and competition intensity during the consumption of an unpredictable resource linked to key ecosystem processes.

Assessment of chlorinated pesticide exposure to white-rumped vulture Gyps bengalensis in India.

Populations of the critically endangered white-rumped vulture (WRV) Gyps bengalensis have declined drastically due to the use of diclofenac for veterinary purposes in Indian subcontinent. Thirty-two dead WRVs collected from three states, namely Gujarat, Assam and Tamil Nadu in India between 2011 and 2014 were investigated to understand the role of diclofenac in the death, and the results were published. Furthermore, since organochlorine pesticides have been linked to long-term impact on populations in many species of birds across the globe, available tissues of 21 WRVs were tested also for six organochlorine pesticides (DDT, HCH, endosulfan, heptachlor, dieldrin and dicofol) and chlorpyrifos. All vultures were found to have had one or more detectable levels of pesticides in their tissues except one. Similarly, all the pesticides included in the study were detected in at least one of the vultures analysed. DDT (95.2%) was the most frequently detected pesticide followed by HCH (90.5%), and DDT (73.6%) contributed the most to the total pesticide load. Total pesticide load ranged between below detection limit (BDL) and 8753.4 ng/g. High levels of total pesticide load recorded in gut contents showed recent exposure to these legacy pesticides even long after their ban. However, it is perceived that studied pesticides' exposure to birds and their presence in the environment is in decreasing trend in India. Although, varying levels of pesticides were detected, all of which were below the levels reported to be toxic, and also reported earlier in the same species in India. Recorded levels may not create a problem to vultures unlike diclofenac; nevertheless, as continued exposure to the pesticides studied may lead to sub lethal effects in birds, it is prudent to monitor these pesticides along with new generation pesticides and NSAIDs in the critically endangered white-rumped vulture in India, towards its conservation.

Animal behaviour: Darwin's mischievous hat stealers are innovative problem solvers.

A new study shows a falcon species, the striated caracara, displays similar levels of behavioural innovation to tool-using parrots when solving a battery test in the wild.

Innovative problem solving by wild falcons.

Innovation (i.e., a new solution to a familiar problem, or applying an existing behavior to a novel problem1,2) plays a fundamental role in species' ecology and evolution. It can be a useful measure for cross-group comparisons of behavioral and cognitive flexibility and a proxy for general intelligence.3,4,5 Among birds, experimental studies of innovation (and cognition more generally) are largely from captive corvids and parrots,6,7,8,9,10,11,12 though we lack serious models for avian technical intelligence outside these taxa. Striated caracaras (Phalcoboenus australis) are Falconiformes, sister clade to parrots and passerines,13,14,15 and those endemic to the Falkland Islands (Malvinas) show curiosity and neophilia similar to notoriously neophilic kea parrots16,17 and face similar socio-ecological pressures to corvids and parrots.18,19 We tested wild striated caracaras as a new avian model for technical cognition and innovation using a field-applicable 8-task comparative paradigm (adapted from Rössler et al.20 and Auersperg et al.21). The setup allowed us to assess behavior, rate, and flexibility of problem solving over repeated exposure in a natural setting. Like other generalist species with low neophobia,21,22 we predicted caracaras to demonstrate a haptic approach to solving tasks, flexibly switching to new, unsolved problems and improving their performance over time. Striated caracaras performed comparably to tool-using parrots,20 nearly reaching ceiling levels of innovation in few trials, repeatedly and flexibly solving tasks, and rapidly learning. We attribute our findings to the birds' ecology, including geographic restriction, resource unpredictability, and opportunistic generalism,23,24,25 and encourage future work investigating their cognitive abilities in the wild. VIDEO ABSTRACT.

A premature stop codon in the CYP2C19 gene may explain the unexpected sensitivity of vultures to diclofenac toxicity.

The unintended environmental exposure of vultures to diclofenac has resulted in the deaths of millions of old-world vultures on the Asian subcontinent. While toxicity has been since associated with a long half-life of elimination and zero order metabolism, the actual constraint in biotransformation is yet to be clarified. For this study we evaluated if the evident zero order metabolism could be due to defects in the CYP2C9/2C19 enzyme system. For this, using whole genome sequencing and de-novo transcriptome alignment, the vulture CYP2C19 open reading frame was identified through Splign analysis. The result sequence analysis revealed the presence of a premature stop codon on intron 7 of the identified open reading frame. Even if the stop codon was not present, amino acid residue analysis tended to suggest that the enzyme would be lower in activity than the equivalent human enzyme, with differences present at sites 105, 286 and 289. The defect was also conserved across the eight non-related vultures tested. From these results, we conclude that the sensitivity of the old-world vultures to diclofenac is due to the non-expression of a viable CYP2C19 enzyme system. This is not too dissimilar to the effects seen in certain people with a similar defective enzyme.

Evaluation of anticoagulant rodenticide sensitivity by examining in vivo and in vitro responses in avian species, focusing on raptors.

Anticoagulant rodenticides (ARs) are used to control pest rodent species but can result in secondary poisoning of non-target animals, especially raptors. In the present study, differences in AR sensitivity among avian species were evaluated by comparing in vivo warfarin pharmacokinetics and effects, measuring cytochrome P450s (CYPs) expression involved in AR metabolism, and conducting in vitro inhibition assays of the AR target enzyme Vitamin K 2,3-epoxide reductase (VKOR). Oral administration of warfarin at 4 mg/kg body weight did not prolong prothrombin time in chickens (Gallus gallus), rock pigeons (Columba livia), or Eastern buzzards (Buteo japonicus). Rock pigeons and buzzards exhibited shorter plasma half-life of warfarin compared to chickens. For the metabolite analysis, 4'-hydroxywarfarin was predominantly detected in all birds, while 10-hydroxywarfarin was only found in pigeons and raptors, indicating interspecific differences in AR metabolism among birds likely due to differential expression of CYP enzymes involved in the metabolism of ARs and variation of VKOR activities among these avian species. The present findings, and results of our earlier investigations, demonstrate pronounced differences in AR sensitivity and pharmacokinetics among bird species, and in particular raptors. While ecological risk assessment and mitigation efforts for ARs have been extensive, AR exposure and adverse effects in predatory and scavenging wildlife continues. Toxicokinetic and toxicodynamic data will assist in such risk assessments and mitigation efforts.

Sub-lethal impacts of lead poisoning on blood biochemistry, immune function and delta-aminolevulinic acid dehydratase (δ-ALAD) activity in Cape (Gyps coprotheres) and white-backed (G. africanus) Vulture chicks.

Although the prevalence of lead poisoning in southern Africa's Gyps vultures is now well-established, its finer physiological effects on these endangered species remain poorly characterised. We evaluated the sub-lethal impact of acute lead exposure on Cape and White-backed Vulture chicks from two breeding colonies in South Africa, by analysing its possible effects on key blood biochemistry parameters, immune function, packed cell volume and δ-aminolevulinic acid dehydratase (δ-ALAD) activity. All 37 White-backed Vulture nestlings sampled displayed elevated lead levels (>10 µg/dL), and seven had blood [Pb] >100 µg/dL. Eight of 28 Cape Vulture nestlings sampled had blood [Pb] exceeding background exposure, with one showing blood [Pb] >100 µg/dL. Delta-aminolevulinic acid dehydratase (δ-ALAD) activity was significantly and negatively related to blood [Pb] in nestlings from both species, with 50% inhibition of the enzyme predicted to occur at blood [Pb] = 52.8 µg/dL (White-backed Vulture) and 18.8 µg/dL (Cape Vulture). Although no significant relationship was found between % packed cell volume (PCV) and blood [Pb], the relatively lower mean PCV of 32.9% in White-backed Vulture chicks, combined with normal serum protein values, is likely indicative of depression or haemolytic anaemia. The leukogram was consistent in both species, although the presence of immature heterophils suggested an inflammatory response in White-backed Vulture chicks with blood [Pb] >100 µg/dL. Values for cholesterol, triglycerides, total serum protein, albumin, globulin, albumin/globulin ratio, alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) were consistent with values previously reported. Calcium and phosphorus concentrations suggested no adverse effects on bone metabolism. A significant decrease in urea: uric acid (U:UA) ratio at blood [Pb] >100 µg/dL in White-backed Vulture chicks, brought about by a decrease in urea production, raises the possibility of hepatic abnormality. These results suggest that δ-ALAD activity may serve as a sensitive biomarker of lead toxicity in both species, while highlighting the need to better understand the significant variability in sensitivity that is observed, even between closely related members of the same genus.

OVME-REG: Harris hawks optimization algorithm based optimized variational mode extraction for eye blink artifact removal from EEG signal.

The electroencephalogram (EEG) recordings from the human brain are useful for detecting various brain syndromes. These recordings are typically contaminated by high amplitude eye blink artifacts, which leads to deliberate misinterpretation of the EEG signal. Recently, variational mode extraction (VME) has been used to detect eye blink artifacts. But, the VME performance is impacted by the balancing parameter and center frequency selection. Therefore, this research uses two metaheuristic algorithms, particle swarm optimization and Harris hawks optimization, to determine the optimal set of the VME parameters. In the proposed method, the optimized VME (OVME) extracts the desired mode to locate the eye blink artifactual intervals. Then, the regression analysis (REG) filters the identified artifactual intervals from short EEG data segments. The significance of the proposed OVME-REG algorithm is that it is adequate for determining the optimum values of the VME algorithm. The analysis is carried out on the CHB-MIT Scalp EEG, BCI Competition, and EEG motor movement/imagery datasets. The proposed OVME-REG method provides an improved performance for suppressing single and repeated eye blink artifacts as compared to the current approaches in terms of (a) high correlation coefficient (93.08%, 87.3%, 82.17%), respectively, (b) low value of RRMSE (0.379, 0.506, 0.502), respectively, (c) high SSIM (0.892, 0.842, 0.694), and (d) low computation time and better preservation of the EEG data.