The most obvious lesson from the VIPER project was the time and effort needed to use formal methods properly. Most of the problems arose in the interfaces between different formalisms, e. These interfaces need to be made rigorous or better eliminated. VIPER 1A the latest chip is designed to operate in pairs, to give protection against breakdowns in service as well as design faults.
We have come to regard redundancy and formal design methods as complementary, the one to guard against normal component failures and the other to provide insurance against the risk of the common-cause failures which bedevil reliability predictions. Any future VIPER chips will certainly need improved performance to keep up with increasingly demanding applications. We have a prototype design not yet specified formally which includes 32 and 64 bit multiply, instruction pre-fetch, more efficient interface timing, and a new instruction to allow a quick response to peripheral requests.
Work is under way to specify this device in MIRANDA, and then to refine the spec into a block-level design by top-down transformations. When the refinement is complete, a relatively simple proof checker should be able to demonstrate its correctness. This paper is presented in viewgraph form. A Viper aircraft was redesigned with a new airfoil and engine to verify if improvements can be made to the baseline configuration. The two major redesigning processes were: As a result of these changes: Although the overall drag decreased, the performance remained about the same due to the reduced horsepower available from the Teledyne Continental engine.
This report describes the procedure and properties of the software upgrade for the Vibration Performance Recorder. The upgrade was successfully installed and uploaded into the Viper and the field laptop. The memory checking routine must run overnight to complete the test, although the laptop need only be connected to the Viper unit until the downloading routine is finished. The routine has limited ability to recognize incomplete or corrupt header and footer files. The routine requires Megabytes of free hard disk space.
Identification of cDNAs encoding viper venom hyaluronidases: The immobilisation of prey by snakes is most efficiently achieved by the rapid dissemination of venom from its site of injection into the blood stream. Hyaluronidase is a common component of snake venoms and has been termed the "venom spreading factor". In the absence of nucleotide or protein sequence data to confirm the functional identity of this venom component, we interrogated a venom gland EST database for the saw-scaled viper , Echis ocellatus Nigeria , using the gene ontology GO term "carbohydrate metabolism".
Although very different from the bee venom and mammalian hyaluronidase sequences, the E. Smaller amplicons, lacking hyaluronidase catalytic residues because of bp or bp central deletions, appear to encode either truncated peptides without hyaluronidase activity, or are non-translated transcripts because they lack consensus translation initiating motifs.
Predator facilitation or interference: In predator-prey foraging games, the prey's reaction to one type of predator may either facilitate or hinder the success of another predator. We ask, do different predator species affect each other's patch selection? If the predators facilitate each other, they should prefer to hunt in the same patch; if they interfere, they should prefer to hunt alone. We performed an experiment in a large outdoor vivarium where we presented barn owls Tyto alba with a choice of hunting greater Egyptian gerbils Gerbillus pyramidum in patches with or without Saharan horned vipers Cerastes cerastes.
Gerbils foraged on feeding trays set under bushes or in the open. We monitored owl location, activity, and hunting attempts, viper activity and ambush site location, and the foraging behavior of the gerbils in bush and open microhabitats. Owls directed more attacks towards patches with vipers , and vipers were more active in the presence of owls. Owls and vipers facilitated each other's hunting through their combined effect on gerbil behavior, especially on full moon nights when vipers are more active. Owls forced gerbils into the bushes where vipers preferred to ambush, while viper presence chased gerbils into the open where they were exposed to owls.
Owls and vipers took advantage of their indirect positive effect on each other. In the foraging game context, they improve each other's patch quality and hunting success. Persistent pit viper envenomation in a cat. The cat was diagnosed with suspected pit viper envenomation based on the location and appearance of the bite wounds, as well as the presence of severe coagulopathy with prolonged activated coagulation time s , which responded to antivenom administration.
The clinical course of the cat was unique owing to the prolonged clinical signs of envenomation that appeared as intermittent coagulopathy and hemorrhage over a 2 week period. Five vials of antivenom were administered and three units of packed red blood cells were transfused over a 7 day period. The cat made a complete recovery with cessation of hemorrhage and normalization of clotting times. This is the first report of persistent pit viper venom-induced coagulopathy in the feline veterinary literature. Virtual Intelligent Planetary Exploration Rover.
Simulation and visualization of rover behavior are critical capabilities for scientists and rover operators to construct, test, and validate plans for commanding a remote rover. This work is part of a larger vision of a science-centered rover control environment, where a scientist may inspect and explore the environment via VR tools, specify science goals, and visualize the expected and actual behavior of the remote rover. The VIPER system is constructed from three generic systems, linked together via a minimal amount of customization into the integrated system.
The complete system points out the power of combining plan execution, simulation, and visualization for envisioning rover behavior; it also demonstrates the utility of developing generic technologies. Debunking the viper 's strike: To survive, organisms must avoid predation and acquire nutrients and energy.
Sensory systems must correctly differentiate between potential predators and prey, and elicit behaviours that adjust distances accordingly. For snakes, strikes can serve both purposes. Vipers are thought to have the fastest strikes among snakes. However, strike performance has been measured in very few species, especially non- vipers. We measured defensive strike performance in harmless Texas ratsnakes and two species of vipers , western cottonmouths and western diamond-backed rattlesnakes, using high-speed video recordings. We show that ratsnake strike performance matches or exceeds that of vipers.
In contrast with the literature over the past century, vipers do not represent the pinnacle of strike performance in snakes. Both harmless and venomous snakes can strike with very high accelerations that have two key consequences: Both harmless and venomous snakes can strike faster than the blink of an eye and often reach a target before it can move. The VIPER was carefully specified and partially verified in an attempt to provide a microprocessor with completely predictable operating characteristics.
The specification of VIPER is divided into several levels of abstraction, from a gate-level description up to an instruction execution model. Although the consistency between certain levels was demonstrated with mechanically-assisted mathematical proof, the formal verification of VIPER was never completed.
Ambush foragers use a hunting strategy that places them at risk of predation by both visual and olfaction-oriented predators. Resulting selective pressures have driven the evolution of impressive visual crypsis in many ambushing species, and may have led to the development of chemical crypsis. However, unlike for visual crypsis, few studies have attempted to demonstrate chemical crypsis. Field observations of puff adders Bitis arietans going undetected by several scent-orientated predator and prey species led us to investigate chemical crypsis in this ambushing species.
We trained dogs Canis familiaris and meerkats Suricata suricatta to test whether a canid and a herpestid predator could detect B. We also tested for chemical crypsis in five species of active foraging snakes, predicted to be easily detectable. Dogs and meerkats unambiguously indicated active foraging species, but failed to correctly indicate puff adder, confirming that B. This is the first demonstration of chemical crypsis anti-predatory behaviour, though the phenomenon may be widespread among ambushers, especially those that experience high mortality rates owing to predation.
Our study provides additional evidence for the existence of an ongoing chemically mediated arms race between predator and prey species. Factors influencing habitat selection by arboreal pit vipers. We studied factors influencing habitat selection by two arboreal species of pit viper , namely Trimeresurus malabaricus Malabar pit viper and T. The macrohabitat of these species was classified as forest, forest edge, or open habitat. To determine microhabitat selection, a variety of features at every other snake location were measured.
Assessment of habitat was done to determine how patterns of habitat use vary seasonally. Shaded ambient air temperatures and humidity were recorded. Data pertaining to 90 individuals of T. Trimeresurus malabaricus selected home ranges that included areas with thick vegetation and were encountered at regions of higher altitude. Neither of the species was found in open habitats. Both of the species preferred diverse habitats and were spread over the entire available space during the monsoon; they did not show any preference for the perch height during different seasons.
Males had a positive correlation between body mass and preferred perch diameter. The present study suggests that several factors play an important role in habitat selection by these arboreal pit vipers , thus making them highly habitat-specific. The experiment consisted of selecting a control law, writing the control law algorithm for the VIPER processor, and providing real time, dynamic inputs into the processor and monitoring the outputs.
The control law selected and coded for the VIPER processor was the yaw damper function of an automatic landing program for a aircraft. Peptides from puff adder Bitis arietans venom, novel inhibitors of nicotinic acetylcholine receptors. Further studies indicated that low molecular weight fractions of puff adder venom inhibit nAChRs as well.
In this paper, we report on isolation from this venom and characterization of three novel peptides called baptides 1, 2 and 3 that reversibly block nAChRs. To isolate the peptides, the venom of B. The amino acid sequences of peptides were established by de novo sequencing using MALDI mass spectrometry.
Baptide 1 comprised 7, baptides 2 and amino acid residues, the latter being acetylated at the N-terminus. This is the first indication for the presence of such post-translational modification in snake venom proteins. None of the peptides contain cysteine residues. For biological activity studies the peptides were prepared by solid phase peptide synthesis.
Unfortunately, the proof became too complex and unmanageable within the given time and funding constraints, and is thus incomplete as of the date of this report. Deriving from recent results in hardware verification research at UC Davis, the approach has been to redesign the electronic block model to make it microcoded and to structure the proof in a series of decreasingly abstract interpreter levels, the lowest being the electronic block level.
Owing to the new approach and some results on the proof of generic interpreters as applied to simple microprocessors, this attempt required an effort approximately an order of magnitude less than the previous one. At the lowest level are the gate-level models in proprietary CAD languages. The block-level and gate-level specifications are also given in the ELLA simulation language. Among VIPER 's deficiencies are the fact that there is no notion of external events in the top-level specification, and it is impossible to use the top-level specifications to prove abstract properties of programs running on VIPER computers.
There is no complete proof that the gate-level specifications implement the top-level specifications. Cohn's proof that the major-state machine correctly implements the top-level specifications has no formal connection with any of the other proof attempts. None of the latter address resetting the machine, memory timeout, forced error, or single step modes. VizieR Online Data Catalog: Chronic Pain after Amputation: The current proposal also attempts to With the rapid development in next-generation sequencing, cost and time requirements for genomic sequencing are decreasing, enabling applications in many areas such as cancer research.
Many tools have been developed to analyze genomic variation ranging from single nucleotide variants to whole chromosomal aberrations. As sequencing throughput increases, the number of variants called by such tools also grows. Often employed manual inspection of such calls is thus becoming a time-consuming procedure. Analysts can then quickly iterate through variants, apply filters and make decisions based on the generated images and variant metadata. VIPER was successfully employed in analyses with manual inspection of more than 10 calls. Supplementary data are available at Bioinformatics online.
European viper envenomation recorded by French poison control centers: A clinical assessment and management study. Immunotherapy is the gold standard treatment for patients bitten by European vipers in France; it significantly decreases morbidity, frequency and severity of complications and length of stay. A national prospective study was performed by all Poison Control Centers PCC to validate the emergency protocol for viper envenomations. In , cases of viper bites were collected: One death was reported. Five patients had neurological signs.
It also shows the extension of neurotoxic venom of vipers in France. Ferlaviruses FV, previously referred to as ophidian paramyxoviruses, OPMV , are enveloped viruses with a negative-strand RNA genome, affecting snakes in captivity worldwide. Infection is characterized by respiratory and nervous clinical signs and carries high mortality rates, but no specific treatment or vaccine is currently available. Costa Rica has 16 species of vipers , found in captivity in collections essential for antivenom production, reintroduction, and public education. The objective of this study was to determine seroprevalence and FV shedding in samples from captive vipers in nine collections across Costa Rica.
A hemagglutination inhibition HI assay was performed to determine the antibody titer against two Ferlavirus strains, Bush viper virus BV and Neotropical virus NT , and reverse-transcriptase polymerase chain reaction RT-PCR and sequencing to determine virus secretion in cloacal swabs. Ferlavirus strains were replicated in Vero cells, and chicken anti-FV polyclonal antibodies were produced and used as a positive control serum for the HI. Results demonstrate that seroprevalence of anti-FV antibodies in viper serum was Furthermore, molecular characterization of FV group A was possible by sequencing the virus recovered from three cloacal swabs, demonstrating circulation of FV in one collection.
This study demonstrates for the first time serological evidence of FV exposure and infection in vipers in captivity in Costa Rica, and suggests cross reactivity between antibodies against both strains. Appropriate biosafety measures could prevent the spread of FV between and within collections of reptiles in the country. Fangs are specialised long teeth that contain either a superficial groove Gila monster, Beaded lizard, some colubrid snakes , along which the venom runs, or an enclosed canal viperid, elapid and atractaspid , down which the venom flows inside the tooth.
The fangs of viperid snakes are the most effective venom-delivery structures among vertebrates and have been the focus of scientific interests for more than years. Despite this interest the questions of how the canal at the centre of the fang forms remains unresolved. Two different hypotheses have been suggested. The mainstream hypothesis claims that the venom-conducting canal develops by the invagination of the epithelial wall of the developing tooth germ.
The sides of this invagination make contact and finally fuse to form the enclosed canal. The second hypothesis, known as the "brick chimney", claims the venom-conducting canal develops directly by successive dentine deposition as the tooth develops. The fang is thus built up from the tip to the base, without any folding of the tooth surface. In an attempt to cast further light on this subject the early development of the fangs was followed in a pit viper , Trimeresurus albolabris, using the expression of Sonic hedgehog Shh.
We demonstrate that the canal is indeed formed by an early folding event, resulting from an invagination of epithelial cells into the dental mesenchyme. The epithelial cells proliferate to enlarge the canal and then the cells die by apoptosis, forming an empty tube through which the poison runs. The entrance and discharge orifices at either end of the canal develop by a similar invagination but the initial width of the invagination is very different from that in the middle of the tooth, and is associated with higher proliferation. The two sides of the invaginating epithelium never come into contact, leaving the orifice open.
The mechanism by which the orifices form can be likened to that observed in reptiles with an open groove along. Asp Viper Vipera aspis envenomation: A retrospective case review study of viper envenomations collected by the Marseille's Poison Centre between and was performed. G1 patients received symptomatic treatments average hospital stay 0.
The hospital stay was significantly reduced in the antivenom treated group p viper venom-induced toxicity. Asp Viper Vipera aspis Envenomation: Experience of the Marseille Poison Centre from to Bernheimer and Leonard A. Bernheimer , and L. Isolation of a toxin from venom of Waglers pit viper Trimeresurus wagleri. Several fast food companies, Internet giants like Russell's viper envenoming is a major problem in South Asia and causes venom induced consumption coagulopathy. This study aimed to investigate the kinetics and dynamics of venom and clotting function in Russell's viper envenoming.
The median age was 39 y y and were male. The median peak INR was 6. Severity of clotting abnormalities was associated with venom concentrations. The phenomenon of Batesian mimicry, where a palatable animal gains protection against predation by resembling an unpalatable model, has been a core interest of evolutionary biologists for years.
An extensive range of studies has focused on revealing mechanistic aspects of mimicry shared education and generalization of predators and the evolutionary dynamics of mimicry systems co-operation vs. However, according to our knowledge, there are no case studies where mimicry theories have been applied to conservation of mimetic species.
Theoretically, mimicry affects, for example, frequency dependency of predator avoidance learning and human induced mortality. To quantify the added predation risk on smooth snakes caused by the rarity of vipers , we calculated risk estimates from experimental data. Resemblance of vipers enhances survival of smooth snakes against bird predation because many predators avoid touching venomous vipers. Mimetic resemblance is however disadvantageous against human predators, who kill venomous vipers and accidentally kill endangered, protected smooth snakes. Because Batesian mimicry is advantageous for the mimic only if model species exist in sufficiently high numbers, it is likely that the conservation program for smooth snakes will fail if adders continue to be destroyed.
Understanding the population consequences of mimetic species may be crucial to the success of endangered species conservation. We suggest that when a Batesian mimic requires protection, conservation planners should. This study assessed the cost benefit of Pit Viper deployment for 80 tank farm pits between October 1, and September 30, under the technical baseline for applicable double-shell tank DST and single-shell tank SST projects. After this assessment had been completed, the U. This study estimates the return on investment ROI and the number of pits where Pit Viper deployment would break even or save money over current manual practices.
The results of the analysis indicate a positive return on the federal investment for deployment of the Pit Viper provided it is used on a sufficient number of pits. It comprises spectroscopic measurements together with all additional information necessary for optimal scientific exploitation of the data, in particular the associated photometric measurements and quantification of the photometric and survey completeness.
Background Pedigree genotype datasets are used for analysing genetic inheritance and to map genetic markers and traits. Such datasets consist of hundreds of related animals genotyped for thousands of genetic markers and invariably contain multiple errors in both the pedigree structure and in the associated individual genotype data. These errors manifest as apparent inheritance inconsistencies in the pedigree, and invalidate analyses of marker inheritance patterns across the dataset. Cleaning raw datasets of bad data points incorrect pedigree relationships, unreliable marker assays, suspect samples, bad genotype results etc.
In order to assist this process we are developing VIPER Visual Pedigree Explorer , a software tool that integrates an inheritance-checking algorithm with a novel space-efficient pedigree visualisation, so that reported inheritance inconsistencies are overlaid on an interactive, navigable representation of the pedigree structure. Methods and results This paper describes an evaluation of how VIPER displays the different scales and types of dataset that occur experimentally, with a description of how VIPER 's display interface and functionality meet the challenges presented by such data.
We examine a range of possible error types found in real and simulated pedigree genotype datasets, demonstrating how these errors are exposed and explored using the VIPER interface and we evaluate the utility and usability of the interface to the domain expert. Evaluation was performed as a two stage process with the assistance of domain experts geneticists. The initial evaluation drove the iterative implementation of further features in the software prototype, as required by the users, prior to a final functional evaluation of the pedigree display for exploring the various error types, data scales and structures.
When evaluating vision, it is important to assess not just the ability to read letters on a vision chart, but also how well one sees in real life scenarios. A Warfighter's ability to read signs and detect and identify objects is crucial, not only when deployed in a military setting, but also in their civilian lives. Designed to use interactive video image controlled environments at daytime, dusk, night, and with thermal imaging vision, it simulates the experience of viewing and identifying road signs and other objects while driving.
We hypothesize that VIPER will facilitate efficient and quantifiable assessment of changes in vision and measurement of functional military performance. Video images were recorded on an isolated 1. VIPER permits the observer to indicate when a target is seen and when it is identified.
Distances at which the observer recognizes and identifies targets are automatically logged. Errors in recognition and identification are also recorded. This first report describes VIPER 's development and a preliminary study to establish a baseline for its performance. Ultimately, patients are interested in how their vision will affect their ability to perform daily. Reproductive ecology of Vipera latastei, in the Iberian Peninsula: Eurosiberian vipers have been considered model organisms, and studies on their reproductive ecology have afforded much of the current knowledge concerning viviparity in snakes.
The reproductive ecology of Vipera latastei in the Iberian Peninsula was studied by analysing a large sample of specimens from collections, to better understand the conservation status of this Mediterranean viper. Males and females matured at small and similar body sizes and mm snout-vent length, respectively and reproductive cycles in both sexes were seasonal. Spermatogenesis peaked in August, vitellogenesis developed in spring and the timing of the mating period was puzzling, with populations mating in autumn, spring, or in both seasons.
The most striking finding was that adult females reproduced triennially on average. Lataste's viper is currently in continuous decline in the IP, and most of its populations are isolated in Mediterranean mountains. We hypothesize that prey scarcity and the brevity of the activity period in mountain habitats diminishes the ability of vipers to recover over the short term the energy expended in reproduction. The species needs 2 years for the acquisition and storage of energy "capital breeder" , and a third year for the expenditure of this energy in vitellogenesis and embryogenesis , a year during which females feed consistently "income breeder".
Thus, this viper combines both strategies to supply the reproductive energy cost. Current decline in population and distribution, together with a poor capacity to renew populations, renders Lataste's viper vulnerable to environmental stochasticity. Full spectroscopic data and auxiliary information release PDR We release redshifts, spectra, CFHTLS magnitudes and ancillary information as masks and weights for a complete sample of 86 galaxies plus other objects, including stars and serendipitous galaxies ; we also include their full photometrically-selected parent catalogue.
All data are available at vipers. A and partly Also based on observations obtained with. Comparative analyses of putative toxin gene homologs from an Old World viper , Daboia russelii. Availability of snake genome sequences has opened up exciting areas of research on comparative genomics and gene diversity. One of the challenges in studying snake genomes is the acquisition of biological material from live animals, especially from the venomous ones, making the process cumbersome and time-consuming.
Similarly, residues F10, Y11 and E20 appear to play an important role in the protein structures across the kunitz protein domain of viperids and elapids. Our study highlights the usefulness of shed skin in obtaining good quality high-molecular weight DNA for comparative genomic studies, and provides evidence towards the unique features and evolution of putative venom gene homologs in vipers.
The thermal background determines how the infrared and visual systems interact in pit vipers. The thermal infrared IR sensing system of pit vipers is believed to complement vision and provide a substitute imaging system in dark environments. Theoretically, the IR system would best image a scene consisting of a homothermal target in cold surroundings as a bright spot on a dark background.
The results thus revealed that the pit viper IR system can accomplish a 'brightness constancy' computation reflecting the difference between the target and background temperatures, much as the visual system compares the luminance of a figure and the background. Furthermore, the results show that the IR system performs less well for locating prey when the background is warmer than the target. Published by The Company of Biologists Ltd. Venomics of New World pit vipers: We report a genus-wide comparison of venom proteome variation across New World pit vipers in the genus Agkistrodon.
Despite the wide variety of habitats occupied by this genus and that all its taxa feed on diverse species of vertebrates and invertebrate prey, the venom proteomes of copperheads, cottonmouths, and cantils are remarkably similar, both in the type and relative abundance of their different toxin families. The venoms from all the eleven species and subspecies sampled showed relatively similar proteolytic and PLA2 activities.
In contrast, quantitative differences were observed in hemorrhagic and myotoxic activities in mice. The highest myotoxic activity was observed with the venoms of A. The venoms of Agkistrodon bilineatus subspecies showed the highest hemorrhagic activity and A. Compositional and toxicological analyses agree with clinical observations of envenomations by Agkistrodon in the USA and Central America. A comparative analysis of Agkistrodon shows that venom divergence tracks phylogeny of this genus to a greater extent than in Sistrurus rattlesnakes, suggesting that the distinct natural histories of Agkistrodon and Sistrurus clades may have played a key role in molding the patterns of evolution of their venom protein genes.
A deep understanding of the structural and functional profiles of venoms and of the principles governing the evolution of venomous systems is a goal of venomics. Isolated proteomics analyses have been conducted on venoms from many species of vipers and pit vipers. However, making sense of these large inventories of data requires the integration of this information across multiple species to identify evolutionary and ecological trends.
Our genus-wide venomics study provides a comprehensive overview of the toxic arsenal across Agkistrodon and a ground for. A randomized controlled trial of fresh frozen plasma for coagulopathy in Russell's viper Daboia russelii envenoming. Essentials Russell's viper envenoming is a major health issue in South Asia and causes coagulopathy. We studied the effect of fresh frozen plasma and two antivenom doses on correcting coagulopathy.
Fresh frozen plasma did not hasten recovery of coagulopathy. Low-dose antivenom did not worsen coagulopathy. Patients with suspected Russell's viper bites and coagulopathy were randomly allocated 1: Science Highlights and Final Data Release. The VIMOS Public Extragalactic Redshift Survey VIPERS released its final set of nearly 90 galaxy redshifts in November , together with a series of science papers that range from the detailed evolution of galaxies over the past 8 Gyr to the growth rate and the power spectrum of cosmological structures measured at about half the Hubble time.
These are the results of a map of the distribution of galaxies and their properties which is unprecedented in its combination of large volume and detailed sampling at 0. Evolutionary trajectories of snake genes and genomes revealed by comparative analyses of five-pacer viper. Snakes have numerous features distinctive from other tetrapods and a rich history of genome evolution that is still obscure. Here, we report the high-quality genome of the five-pacer viper , Deinagkistrodon acutus, and comparative analyses with other representative snake and lizard genomes.
We map the evolutionary trajectories of transposable elements TEs , developmental genes and sex chromosomes onto the snake phylogeny. TEs exhibit dynamic lineage-specific expansion, and many viper TEs show brain-specific gene expression along with their nearby genes. We detect signatures of adaptive evolution in olfactory, venom and thermal-sensing genes and also functional degeneration of genes associated with vision and hearing.
Lineage-specific relaxation of functional constraints on respective Hox and Tbx limb-patterning genes supports fossil evidence for a successive loss of forelimbs then hindlimbs during snake evolution. Finally, we infer that the ZW sex chromosome pair had undergone at least three recombination suppression events in the ancestor of advanced snakes. These results altogether forge a framework for our deep understanding into snakes' history of molecular evolution.
Both visual and infrared IR senses are utilized in prey targeting by pit vipers. Visual and IR inputs project to the contralateral optic tectum where they activate both multimodal and bimodal neurons. A series of ocular and pit organ occlusion experiments using the short-tailed pit viper Gloydius brevicaudus were conducted to investigate the role of visual and IR information during prey targeting.
Subjects with one eye and one pit occluded on the same side of the face performed as well as those with bilateral occlusion although these subjects showed a significant targeting angle bias toward the unoccluded side. Performance was significantly poorer when only a single eye or pit was available. Interestingly, when one eye and one pit organ were occluded on opposite sides of the face, performance was poorest, the snakes striking prey on no more than half the trials. These results indicate that, visual and infrared information are both effective in prey targeting in this species, although interference between the two modalities occurs if visual and IR information is restricted to opposite sides of the brain.
Viper 's bugloss Echium spp. As anticipated, a relationship was observed between the proportion of this pollen and the properties of the honey. Immersing the injured part in warm 45 degrees C water is considered the first and foremost important treatment as it is reported to relieve pain and inactivate the venom. Other methods of analgesia are discussed. We present a case of lionfish envenomation that failed to respond to warm water immersion.
Venomous aquatic animals are hazardous to swimmers, surfers, divers, and fishermen. Exposures include mild stings, bites, abrasions, and lacerations. Severe envenomations can be life threatening. This article reviews common marine envenomations , exploring causative species, clinical presentation, and current treatment recommendations.
Recommendations are included for cnidaria, sponges, bristle worms, crown-of-thorns starfish, sea urchins, venomous fish, stingrays, cone snails, stonefish, blue-ringed octopus, and sea snakes. Immediate and long-term treatment options and management of common sequelae are reviewed. Antivenom administration, treatment of anaphylaxis, and surgical indications are discussed. Syndromic approach to treatment of snake bite in Sri Lanka based on results of a prospective national hospital-based survey of patients envenomed by identified snakes.
Russell's vipers Daboia russelii and hump-nosed pit vipers Hypnale hypnale were the most numerous and H. Distinctive clinical syndromes were identified to aid species diagnosis in most cases of snake bite in Sri Lanka where the biting species is unknown. Although only polyspecific antivenoms are used in Sri Lanka, species diagnosis remains important to anticipate life-threatening complications such as local necrosis, hemorrhage and renal and respiratory failure and to identify likely victims of envenoming by H.
The technique of hospital-based collection, labeling and preservation of dead snakes brought by bitten patients is recommended for rapid assessment of a country's medically-important herpetofauna. Inhibition of the hemorrhagic and proteolytic activities of Lansberg's hognose pit viper Porthidium lansbergii hutmanni venom by opossum Didelphis marsupialis serum: Earlier studies have revealed the ability of sera from several mammals to neutralize the toxic effects of snake venom.
The Venezuelan opossum Didelphis marsupialis is one that has been found to inhibit hemorrhagic and proteolytic activities of venoms from many species of snakes. In this article it is shown that the opossum sera and its 0. The protein bands obtained contained molecular weights of approximately 6 to kDa. These results revealed the presence of proteases inhibitors in the opossum sera fractions and the inhibition of venom activity by opossum sera suggesting a reciprocal adaptation at the molecular level.
Marine stings are common but most are minor and do not require medical intervention. Severe and systemic marine envenoming is uncommon, but includes box jellyfish stings, Irukandji syndrome, major stingray trauma and blue-ringed octopus envenoming. Almost all marine injuries are caused by jellyfish stings, and penetrating injuries from spiny fish, stingrays or sea urchins.
This article describes the presentation and management of marine envenomations and injuries that may occur in Australia. Basic life support is essential for severe marine envenomings that result in cardiac collapse or paralysis. Irukandji syndrome causes severe generalised pain, autonomic excess and minimal local pain, which may require large amounts of analgesia, and, uncommonly, myocardial depression and pulmonary oedema occur.
Penetrating marine injuries can cause significant trauma depending on location of the injury.
Large and unclean wounds may have delayed healing and secondary infection if not adequately irrigated, debrided and observed. Reversible atrial fibrillation following Crotalinae envenomation. Cardiotoxicity is a documented complication of Crotalinae envenomation. Reported cardiac complications following snake envenomation have included acute myocardial infarction, electrocardiogram abnormalities and arrhythmias. Few reports exist describing arrhythmia induced by viper envenomation and to our knowledge none describe arrhythmia induced by Crotalinae envenomation.
This report concerns the first known case of atrial fibrillation precipitated by rattlesnake bite. A year-old Caucasian man with a past medical history of hypertension, hyperlipidemia, type 1 diabetes mellitus, and a baseline first-degree atrioventricular block presented to the emergency department following a rattlesnake bite to his left lower leg.
He developed pain and swelling in his left leg two-hour post- envenomation and subsequently received four vials of Crotalidae polyvalent immune fab ovine. At three-hour post- envenomation following transfer to the intensive care unit, an electrocardiogram revealed new-onset atrial fibrillation. An amiodarone drip was started and the patient successfully converted to normal sinus rhythm approximately six hours after he was found to be in atrial fibrillation.
He was discharged the following day with no hematological abnormalities and a baseline first-degree atrioventricular block. This is the first documented case of reversible atrial fibrillation precipitated by Crotalinae envenomation. In patients with pertinent risk factors for developing atrial fibrillation, physicians should be aware of the potential for this arrhythmia. Direct toxic effects of venom or structural and electrophysiological cardiovascular abnormalities may predispose snakebite patients to arrhythmia, warranting extended and attentive cardiac monitoring.
Part Other marine envenomations. Australian waters contain a variety of venomous creatures, including jellyfish, stinging fish, blue-ringed octopus, sea snakes, cone snails and stingrays. Part 2 of this article focusses on common marine envenomations other than jellyfish stings. Even though mortality from these envenomations is low, there is a high level of morbidity especially with stonefish and other stinging fish envenomations. Some envenomations , however, are serious enough to require antivenom treatment and deaths still occasionally occur.
Antivenom for European Vipera species envenoming. European viper bite is relatively uncommon but can cause serious envenoming , particularly swelling and hemorrhage spreading from limb to trunk that can cause long term disability. Systemic features are relatively mild compared to many other venomous species. Moderate-to-severe envenoming requires antivenom, which is given many hundreds of times each year across the continent.
Several Vipera spp antivenoms are produced in Europe, but there is little comparative information available for the antivenoms and none is licensed with the European Medicines Agency. We aimed to collect descriptive data on European viper antivenoms and assess their relative effectiveness. A systematic review of articles relating to antivenom in Europe was performed using the Medline medical database. Articles published between 1 January and 11 March pertaining to clinical outcome, including case reports, were selected.
Referenced articles in the indexed articles were explored for suitability and included if they met any of the criteria: All accepted abstracts from EAPCCT conferences since were searched and abstracts relating to Vipera spp envenoming were assessed for suitability. We extracted data on study type, safety and effectiveness. We sought information on antivenoms from manufacturers and individual patient data from authors of publications. Since individual patient data were only rarely available, we compared median length of stay between case series reporting each antivenom. We identified 40 papers and six published abstracts, and one unpublished paper that reported clinical cases and case series of envenomed patients treated with antivenom.
A Viper aircraft was redesigned with a new airfoil and engine to verify if improvements can be made to the baseline configuration. The two major redesigning processes were: As a result of these changes: Although the overall drag decreased, the performance remained about the same due to the reduced horsepower available from the Teledyne Continental engine. Capillary leak syndrome is a unique complication that follows Russell's viper envenomation.
This syndrome has a very high fatality rate and is characterized by parotid swelling, chemosis, periorbital edema, hypotension, albuminuria, hypoalbuminemia, and hemoconcentration. This syndrome is frequently recognized from the southern parts of India, especially from the state of Kerala.
It has been postulated that a vascular apoptosis inducing component of Russell's viper venom that is not neutralized by the commercially available anti-snake venom ASV is responsible for this complication as it occurs even after adequate doses of ASV administration in most cases. Acute kidney injury often requiring dialysis is invariably present in all patients because of reduced renal perfusion and ischemic acute tubular necrosis as a result of hypotension.
Management mainly involves aggressive fluid resuscitation to maintain adequate tissue perfusion. There are no other proven effective treatment modalities, except a few reports of successful treatment with plasmapheresis. Methylprednisolone pulse therapy, terbutaline, aminophylline, and intravenous immunoglobulin are other treatment modalities tried. Myocardial injury in dogs with snake envenomation and its relation to systemic inflammation. To investigate the presence of myocardial injury in dogs hospitalized for snake envenomation and to examine its relationship with systemic inflammation.
University teaching hospital and small animal referral hospital. Blood was collected from dogs envenomed by V. Blood was collected from dogs envenomed by B. Concentrations of cardiac troponin I cTnI , a marker of myocardial injury, and C-reactive protein CRP , a marker of systemic inflammation, were measured in each blood sample.
A significant correlation between cTnI and CRP concentrations was found at admission, but not at other time points. Myocardial injury frequently occurred in dogs with snake envenomation. While the degree of systemic inflammation was significantly correlated with degree of myocardial injury in V.
This could be due to differences in the toxic substances of the snake venoms or to differences in the cytokines induced by the venom toxins. North American Snake Envenomation. Native US snakes that produce clinically significant envenomation can be divided into 2 groups, crotalids and elapids. The crotalids include rattlesnakes, cottonmouths, and copperheads. Crotalid envenomation can result in significant local tissue damage as well as thrombocytopenia and coagulopathy. Rarely are bites fatal. Native US elapids are all coral snakes that possess neurotoxic venom that can cause weakness, respiratory paralysis, and rarely death.
Treatment of both types of envenomation revolves around general supportive care and antivenom administration when indicated. Previously advocated treatments, such as tourniquets, venom extraction, and bite site excision are not recommended. Russell's viper envenoming is a major problem in South Asia and causes venom induced consumption coagulopathy. This study aimed to investigate the kinetics and dynamics of venom and clotting function in Russell's viper envenoming.
The median age was 39 y y and were male. The median peak INR was 6. Severity of clotting abnormalities was associated with venom concentrations. This report describes the procedure and properties of the software upgrade for the Vibration Performance Recorder. The upgrade was successfully installed and uploaded into the Viper and the field laptop. The memory checking routine must run overnight to complete the test, although the laptop need only be connected to the Viper unit until the downloading routine is finished.
The routine has limited ability to recognize incomplete or corrupt header and footer files. The routine requires Megabytes of free hard disk space. Rhabdomyolysis during envenomation by Physalia sp envenomation in New Caldonia. We report the first case of rhabdomyolysis following envenomation by a Physalia sp in New Caledonia.
Systemic envenomation by this marine hydrozoan is well known, including myalgia as a commonly reported clinical feature. Nonetheless, a related increase in muscle enzymes, featuring rhabdomyolysis, has not previously been described. In this case report, we describe a patient with rhabdomyolysis and acute renal failure. Rhabdomyolysis should be checked in case of systemic physalia envenomation. Factors predictive for death from snake envenomation vary between studies, possibly due to variation in host genetic factors and venom composition.
This study aimed to evaluate predictive factors for death from snake envenomation in Myanmar. A prospective study was performed among adult patients with snakebite admitted to tertiary hospitals in Yangon, Myanmar, from May to August Data including clinical variables and laboratory parameters, management, and outcomes were evaluated. Multivariate regression analysis was performed to evaluate factors predictive for death at the time of presentation to the hospital.
Patients who present with these independent predictive factors should be recognized and provided with early appropriate intervention to reduce the mortality rate among adults with snake envenomation in Myanmar. Lionfish envenomations in Poland.
All the punctures occurred in the victims' hands. Intense pain and systemic findings observed in 11 patients. Enveno-mations had a mild course, the patients were treated for their symptoms. Toxicology information centers have also recorded 3 cases of exposure to tank-bred lionfish in which typical envenomation symptoms did not appear. Those cases were probably what is referred to as "empty stings", in which no toxin is injected into the victim's body.
Empty stings are known to be made by snakes, which can consciously inject no venom, while for lionfish, the lack of exposure to venom was probably caused by the structure of the venom organ in which there was no channel to deliver the venom. Management of envenomations during pregnancy. Envenomations during pregnancy pose all the problems of envenomation in the nonpregnant state with additional complexity related to maternal physiologic changes, medication use during pregnancy, and the well-being of the fetus. We review the obstetric literature and management options available to prevent maternal morbidity and mortality while limiting adverse obstetric outcomes after envenomation in pregnancy.
In January , we searched the U. Search terms included " envenomation in pregnancy," "stings in pregnancy," "antivenom use in pregnancy," "anaphylaxis in pregnancy," and variants of these with known venomous animals. Reference lists generated further case reports and articles. We included English language articles and abstracts. Recommendations for the management of envenomation in pregnancy are guided primarily by studies on nonpregnant persons and case reports of pregnancy. Clinically significant envenomations in pregnancy are reported for snakes, spiders, scorpions, jellyfish, and hymenoptera bees, wasps, hornets, and ants.
Adverse obstetric outcomes including miscarriage, preterm birth, placental abruption, and stillbirth are associated with envenomation in pregnancy. The limited available literature suggests that adverse outcomes are primarily related to venom effects on the mother. Optimization of maternal health such as management of anaphylaxis and antivenom administration is likely the best approach to improve fetal outcomes despite potential risks to the fetus of medication administration during pregnancy.
Obstetric evaluation and fetal. Northern Benin and Maritime Guinea]. We treated patients in northern Benin Atacora and in Maritime Guinea Kindia with confirmed envenomation. Treatment consisted of intravenous administration of 1 vial for uncomplicated envenomation , and 2 vials for hemorrhagic or neurotoxic envenomation. The dose was repeated when bleeding or signs of neurotoxicity persisted or appeared. One patient bitten by a member of the Elapidae family, died despite early treatment. All these symptoms were mild and disappeared rapidly after an antihistamine or corticosteroid treatment.
Clinical consequences of toxic envenomations by Hymenoptera. Many familiar Hymenoptera are brightly colored and can sting painfully-thus, their threat and clinical importance may be exaggerated. Most stinging insects only sting to defend themselves or their colonies from predators. The clinical nature of Hymenoptera envenomations contrasts that of other venomous animals, including other arthropods, primarily because allergic reaction, not direct intoxication, is the usual main concern.
This review focuses mainly on the clinical features of direct toxicity to Hymenoptera envenomations , which can induce a high incidence of acute renal failure, liver failure, multiple organ failures, and death. Toxic mass envenomations by honeybees usually entail many hundreds or more stings per victim. In contrast to honeybee toxic envenomations , hornet sting envenomations can be clinically threatening with only stings needed to cause kidney and other organ failures.
Many lethal envenomations by honeybees occur in rural areas in the New World and Africa and are not recorded or documented. In contrast, deaths by hornets occur mainly to Asia. The most frequent and important envenomating taxa are honeybees, hornets, yellowjacket wasps, paper wasps, fire ants, and jack jumper ants. Occasional envenomating taxa include bumblebees, bullet ants, harvester ants, solitary wasps, solitary bees, and various ants of lesser clinical importance.
Envenomations by Hymenoptera usually can be avoided if one considers that bees, wasps and ants "view" us as potential threats or predators, and that with information about the biology of stinging Hymenoptera, humans can minimize adverse incidents. North American snake and scorpion envenomations.
Envenomations by snakes and scorpions in North America, although uncommon, do occur, and the victims may seek medical treatment. Combined, snake and scorpion encounters result in more than 25, calls a year to poison centers. Although some similarities exist with respect to general signs of envenomation and treatment, specific nuances distinguish the medical care to be anticipated and therapies available. Regardless of geographic practice area, exposures will occur that may result in a significant envenomation.
This article provides critical care nurses with fundamental knowledge of varied snake and scorpion envenomation presentations and treatments to assist in optimizing patient outcomes. Scientists believe the pits may form through a combination of sublimation and ice fracturing. Stonefish "Okoze" envenomation during food preparation. Stonefish is a dangerous and venomous fish commonly found in the shallow waters of the Pacific region.
Its envenomation is reported worldwide with increasing frequency. Although envenomation usually occurs in those engaged in marine sports, chefs may suffer envenomation during cutting stonefish, which is eaten either sliced raw, boiled, or deep-fried by Japanese. Since many people cook and eat Japanese food, it is important to know that cutting a stonefish for cooking carries the risk of envenomation.
However, most primary and emergency physicians have not encountered cases of envenomation during food preparation. Here we describe a case of envenomation occurring while cooking. The patient was a healthy year-old man working as a chef in a Japanese restaurant. He was presented to an academic emergency department after suddenly developing severe pain in his right fourth finger while cutting a stonefish. The finger was reddish, swollen, and tender.
The pain reduce d after immersing his hand in hot water, and disappeared within 18 h without any complication. In this report, we describe the history of stonefish envenomation and provide a brief review of the literature related to this form of envenomation. Predator facilitation or interference: In predator-prey foraging games, the prey's reaction to one type of predator may either facilitate or hinder the success of another predator. We ask, do different predator species affect each other's patch selection?
If the predators facilitate each other, they should prefer to hunt in the same patch; if they interfere, they should prefer to hunt alone. We performed an experiment in a large outdoor vivarium where we presented barn owls Tyto alba with a choice of hunting greater Egyptian gerbils Gerbillus pyramidum in patches with or without Saharan horned vipers Cerastes cerastes. Gerbils foraged on feeding trays set under bushes or in the open.
We monitored owl location, activity, and hunting attempts, viper activity and ambush site location, and the foraging behavior of the gerbils in bush and open microhabitats. Owls directed more attacks towards patches with vipers , and vipers were more active in the presence of owls. Owls and vipers facilitated each other's hunting through their combined effect on gerbil behavior, especially on full moon nights when vipers are more active.
Owls forced gerbils into the bushes where vipers preferred to ambush, while viper presence chased gerbils into the open where they were exposed to owls. Owls and vipers took advantage of their indirect positive effect on each other. In the foraging game context, they improve each other's patch quality and hunting success. Lionfish envenomation of the hand. Lionfish Pterois volitans envenomation of the hand causes excruciating pain and occurs in three grades: The initial treatment in all cases is to soak the hand in nonscalding water 45 degrees C until the pain subsides by denaturing the thermolabile venom proteins.
The blisters should be immediately excised to prevent dermal necrosis, inasmuch as the blister fluid contains residual active venom. To prevent a hypersensitivity reaction, any further contact with the fish should be avoided. Toxicologic information resources for reptile envenomations. The United States is the largest importer of reptiles in the world, with an estimated 1. Envenomations by nonindigenous venomous species are a rare but often serious medical emergency. Bites may occur during the care and handling of legitimate collections found in universities, zoos, or museums.
The other predominant source of exotic envenomation is from amateur collectors participating in importation, propagation, and trade of non-native species. This article provides toxicologic information resources for snake envenomations. Lionfish envenomations in an urban wilderness.
Marine envenomations are commonly encountered along coastal regions of the United States. Although less frequent, marine bites and stings do occur in landlocked locales, such as the Midwest, because of an increased interest in keeping these exotic creatures as pets.
We report 33 cases of envenomations by captive lionfish Pterois volitans called to a regional Chicago poison control center over a 2-year period. The wounds were uniformly on the hand, and all presented with local, intense pain. The majority of envenomations were responsive to prompt immersion in nonscalding water within 90 min, and all were advised on tetanus prophylaxis and local wound care. In all cases, those patients envenomated recovered without permanent sequelae. As a result of increasing encounters with lionfish as pets, health care providers.
Pits such as these commonly form as a result of collapse of surface materials into a subsurface void, possibly along a fault or into an old lava tube. The layered material, exposed near the top of several of the pits , is shedding house-sized boulders which can be seen resting on the sloping sidewalls and floors of many of the pits. Virtual Intelligent Planetary Exploration Rover. Simulation and visualization of rover behavior are critical capabilities for scientists and rover operators to construct, test, and validate plans for commanding a remote rover.
This work is part of a larger vision of a science-centered rover control environment, where a scientist may inspect and explore the environment via VR tools, specify science goals, and visualize the expected and actual behavior of the remote rover. The VIPER system is constructed from three generic systems, linked together via a minimal amount of customization into the integrated system. The complete system points out the power of combining plan execution, simulation, and visualization for envisioning rover behavior; it also demonstrates the utility of developing generic technologies.
Running diagonal from middle-right toward lower left is a trough that intersects the pit. The trough is a typical graben formed by faulting as the upper crust of Mars split and pulled apart at this location. The opening of the graben also led to formation of the collapse pits. Rattlesnake envenomation in 12 New World camelids. Rattlesnake envenomation of New World camelids is a seasonal problem with often dramatic clinical signs. The purpose of this study was to identify the clinical signs, laboratory results, treatment methods, and outcome for rattlesnake envenomation in New World camelids.
Medical records from to were searched for New World camelids presented for rattlesnake bite or clinical signs suspected to be related to recent envenomation. Twelve records were identified. From these records a retrospective study was performed. Swelling of the lips, head and neck, tachypnea, dyspnea, tachycardia, and lethargy were the most common presenting signs. Common complete blood count CBC and serum biochemical abnormalities were neutrophilia, lymphopenia, increased muscle enzyme activity, hypoalbuminemia, hyperglycemia, hypokalemia, and thrombocytopenia.
Treatment included combinations of intravenous fluid therapy, antimicrobials, anti-inflammatory drugs, tetanus prophylaxis, tracheostomy, supplemental oxygen, antivenom, total parenteral nutrition, and nursing care. Five of the 10 animals with acute onset of clinical signs survived, and all animals with subacute presentation died. New World camelids that sustain rattlesnake envenomation and severe facial swelling precluding prehension and mastication have a guarded prognosis for survival.
Aggressive treatment is recommended to optimize the chances of survival. Animals with less severe local tissue reaction and absence of systemic signs have a better prognosis. Stonefish envenomation with acute carpal tunnel syndrome. Stonefish envenomation is a common marine sting.
Although stonefish injuries are commonly sustained during maritime activities, this local delicacy can also be considered a regional occupational hazard for chefs. The availability and consumption of stonefish in local restaurants has increased the risk of acute carpal tunnel syndrome after a stonefish injury. This case report describes acute carpal tunnel syndrome following stonefish envenomation. An excellent recovery was achieved after surgical decompression of the carpal tunnel syndrome. Standard management of stonefish injuries should therefore take into account the possibility that this orthopaedic emergency may complicate the injury.
Snakebite poisoning is a significant medical problem in agricultural societies in Sub Saharan Africa. Antivenom AV is the standard treatment, and we assessed the cost-effectiveness of making it available in 16 countries in West Africa. We determined the cost-effectiveness of AV based on a decision-tree model from a public payer perspective. We derived inputs from the literature which included: Costs incurred by the victims include: The findings were consistent even with variations of inputs in 1-way sensitivity analyses.
In addition, the PSA showed that in the. Hamza, Muhammad; Idris, Maryam A. Background Snakebite poisoning is a significant medical problem in agricultural societies in Sub Saharan Africa. Methods We determined the cost-effectiveness of AV based on a decision-tree model from a public payer perspective. The findings were consistent even with variations of inputs in 1—way sensitivity analyses. Bitis gabonica Gaboon viper snake venom gland: The venom gland of the snake Bitis gabonica Gaboon viper was used for the first time to construct a unidirectional cDNA phage library followed by high-throughput sequencing and bioinformatic analysis.
Hundreds of cDNAs were obtained and clustered into contigs. We found mostly novel full-length cDNA coding for metalloproteases P-II and P-III classes , Lysphospholipase A2, serine proteases with essential mutations in the active site, Kunitz protease inhibitors, several C-type lectins, bradykinin-potentiating peptide, vascular endothelial growth factor, nucleotidases and nucleases, nerve growth factor, and L-amino acid oxidases. Two new members of the recently described short coding region family of disintegrin, displaying RGD and MLD motifs are reported.
In addition, we have identified for the first time a cytokine-like molecule and a multi-Kunitz protease inhibitor in snake venoms. A significant number of sequences were devoid of database matches, suggesting that their biologic function remains to be identified. This paper also reports the N-terminus of the 15 most abundant venom proteins and the sequences matching their corresponding transcripts. We have thus generated a comprehensive catalog of the B. The role of these molecules is discussed in the context of the envenomation caused by the Gaboon viper.
Debunking the viper 's strike: To survive, organisms must avoid predation and acquire nutrients and energy. Sensory systems must correctly differentiate between potential predators and prey, and elicit behaviours that adjust distances accordingly. For snakes, strikes can serve both purposes. Vipers are thought to have the fastest strikes among snakes.
However, strike performance has been measured in very few species, especially non- vipers. We measured defensive strike performance in harmless Texas ratsnakes and two species of vipers , western cottonmouths and western diamond-backed rattlesnakes, using high-speed video recordings. We show that ratsnake strike performance matches or exceeds that of vipers. In contrast with the literature over the past century, vipers do not represent the pinnacle of strike performance in snakes.
Both harmless and venomous snakes can strike with very high accelerations that have two key consequences: Both harmless and venomous snakes can strike faster than the blink of an eye and often reach a target before it can move. Fangs are specialised long teeth that contain either a superficial groove Gila monster, Beaded lizard, some colubrid snakes , along which the venom runs, or an enclosed canal viperid, elapid and atractaspid , down which the venom flows inside the tooth. The fangs of viperid snakes are the most effective venom-delivery structures among vertebrates and have been the focus of scientific interests for more than years.
Despite this interest the questions of how the canal at the centre of the fang forms remains unresolved. Two different hypotheses have been suggested. The mainstream hypothesis claims that the venom-conducting canal develops by the invagination of the epithelial wall of the developing tooth germ. The sides of this invagination make contact and finally fuse to form the enclosed canal.
The second hypothesis, known as the "brick chimney", claims the venom-conducting canal develops directly by successive dentine deposition as the tooth develops. The fang is thus built up from the tip to the base, without any folding of the tooth surface. In an attempt to cast further light on this subject the early development of the fangs was followed in a pit viper , Trimeresurus albolabris, using the expression of Sonic hedgehog Shh.
The pupils dilate suddenly and eye movement resumes when the animal wakes up. Because of their large, heavy body size, the adults have no trouble eating prey as large as fully grown rabbits. When prey happens by, they strike with very fast precision from any angle. Once they strike their prey, they hang on to it with their large fangs rather than letting it go and waiting for it to die. This behaviour is very different from the behaviour of other species of vipers. These snakes feed on a variety of birds and mammals, such as doves, many different species of rodents, including field mice and rats, as well as hares and rabbits.
There are also reports of more unlikely prey items, such as tree monkeys, the brush-tailed porcupine Atherurus and even the small royal antelope Neotragus. During peak sexual activity, males engage in combat. This starts with one male rubbing its chin along the back of the other. The second male will then raise its head as high as possible. As they both do the same, the necks intertwine. When the heads are level, they turn towards each other and push. Their bodies intertwine as they switch positions.
They become oblivious to everything else, continuing even after they fall off a surface or into water. Sometimes they intertwine and squeeze so tightly that their scales stand out from the pressure. They have also been observed to strike at each other with mouths closed. Occasionally, the combatants will tire and break off the fight by "mutual consent", resting for a while before resuming once more. In captivity, combat may occur four or five times a week until courtship and copulation ends. Gestation takes about 7 months, which suggests a breeding cycle of two to three years.
A five-year breeding cycle may also be possible. Usually, they give birth in late summer. Bites from this species are extremely rare, due to their unaggressive nature and because their range is limited to rainforest areas. Even an average bite from an average-sized specimen is potentially fatal. The snake's cytotoxic venom itself is not considered particularly toxic based on tests conducted in mice.
In mice, the LD 50 is 0.
Yield is probably related to body weight, as opposed to milking interval. A study by Marsh and Whaler reported a maximum yield of 9. Two to three electrical bursts within a space of five seconds apart were enough to empty the venom glands. The Gaboon vipers used for the study were milked between seven and 11 times over a month period, during which they remained in good health and the potency of their venom remained the same.
Due to the rarity of these type of snakebites, further investigation is needed. In humans, a bite from a Gaboon viper causes rapid and conspicuous swelling , intense pain , severe shock and local blistering. Other symptoms may include uncoordinated movements, defecation , urination , swelling of the tongue and eyelids, convulsions and unconsciousness.
Both harmless and venomous snakes can strike faster than the blink of an eye and often reach a target before it can move. We show that ratsnake strike performance matches or exceeds that of vipers. The optical effect may play a role in improving the ecological performance of the snake in its natural environment. Immunotherapy is the gold standard treatment for patients bitten by European vipers in France; it significantly decreases morbidity, frequency and severity of complications and length of stay. The latter induced strong myotoxicity in mice, which correlates with its high proportion of phospholipases A 2 , whereas venoms from the two Porthidium species, containing lower amounts of these enzymes, induced only mild muscle damage.
There may be sudden hypotension , heart damage and dyspnoea. According to their research, these two subspecies are as different from each other as they are from B. Consequently, Lenk et al. From Wikipedia, the free encyclopedia. Gaboon viper Gaboon viper Scientific classification Kingdom: Snake Species of the World: