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Sample records for arthropod vibratory communication

  1. Interference of Overlapping Insect Vibratory Communication Signals: An Eushistus heros Model

    PubMed Central

    Čokl, Andrej; Laumann, Raul Alberto; Žunič Kosi, Alenka; Blassioli-Moraes, Maria Carolina; Virant-Doberlet, Meta; Borges, Miguel

    2015-01-01

    Plants limit the range of insect substrate-borne vibratory communication by their architecture and mechanical properties that change transmitted signal time, amplitude and frequency characteristics. Stinkbugs gain higher signal-to-noise ratio and increase communication distance by emitting narrowband low frequency vibratory signals that are tuned with transmission properties of plants. The objective of the present study was to investigate hitherto overlooked consequences of duetting with mutually overlapped narrowband vibratory signals. The overlapped vibrations of the model stinkbug species Eushistus heros, produced naturally or induced artificially on different plants, have been analysed. They represent female and male strategies to preserve information within a complex masked signal. The brown stinkbugs E. heros communicate with species and gender specific vibratory signals that constitute characteristic duets in the calling, courtship and rivalry phases of mating behaviour. The calling female pulse overlaps the male vibratory response when the latency of the latter is shorter than the duration of the female triggering signal or when the male response does not inhibit the following female pulse. Overlapping of signals induces interference that changes their amplitude pattern to a sequence of regularly repeated pulses in which their duration and the difference between frequencies of overlapped vibrations are related inversely. Interference does not occur in overlapped narrow band female calling pulses and broadband male courtship pulse trains. In a duet with overlapped signals females and males change time parameters and increase the frequency difference between signals by changing the frequency level and frequency modulation pattern of their calls. PMID:26098637

  2. Interference of Overlapping Insect Vibratory Communication Signals: An Eushistus heros Model.

    PubMed

    Čokl, Andrej; Laumann, Raul Alberto; Žunič Kosi, Alenka; Blassioli-Moraes, Maria Carolina; Virant-Doberlet, Meta; Borges, Miguel

    2015-01-01

    Plants limit the range of insect substrate-borne vibratory communication by their architecture and mechanical properties that change transmitted signal time, amplitude and frequency characteristics. Stinkbugs gain higher signal-to-noise ratio and increase communication distance by emitting narrowband low frequency vibratory signals that are tuned with transmission properties of plants. The objective of the present study was to investigate hitherto overlooked consequences of duetting with mutually overlapped narrowband vibratory signals. The overlapped vibrations of the model stinkbug species Eushistus heros, produced naturally or induced artificially on different plants, have been analysed. They represent female and male strategies to preserve information within a complex masked signal. The brown stinkbugs E. heros communicate with species and gender specific vibratory signals that constitute characteristic duets in the calling, courtship and rivalry phases of mating behaviour. The calling female pulse overlaps the male vibratory response when the latency of the latter is shorter than the duration of the female triggering signal or when the male response does not inhibit the following female pulse. Overlapping of signals induces interference that changes their amplitude pattern to a sequence of regularly repeated pulses in which their duration and the difference between frequencies of overlapped vibrations are related inversely. Interference does not occur in overlapped narrow band female calling pulses and broadband male courtship pulse trains. In a duet with overlapped signals females and males change time parameters and increase the frequency difference between signals by changing the frequency level and frequency modulation pattern of their calls. PMID:26098637

  3. Deceptive vibratory communication: pupae of a beetle exploit the freeze response of larvae to protect themselves

    PubMed Central

    Kojima, Wataru; Ishikawa, Yukio; Takanashi, Takuma

    2012-01-01

    It is argued that animal signals may have evolved so as to manipulate the response of receivers in a way that increases the fitness of the signallers. In deceptive communication, receivers incur costs by responding to false signals. Recently, we reported that pupae of the soil-inhabiting Japanese rhinoceros beetle Trypoxylus dichotoma produce vibratory signals to deter burrowing larvae, thereby protecting themselves. In the present study, monitoring of vibrations associated with larval movement revealed that T. dichotoma larvae remained motionless for ca 10 min when pupal vibratory signals were played back transiently (freeze response). Furthermore, pupal signals of T. dichotoma elicited a freeze response in three other scarabaeid species, whose pupae do not produce vibratory signals. This indicates that the freeze response to certain types of vibration evolved before the divergence of these species and has been evolutionarily conserved, presumably because of the fitness advantage in avoiding predators. Pupae of T. dichotoma have probably exploited pre-existing anti-predator responses of conspecific larvae to protect themselves by emitting deceptive vibratory signals. PMID:22675138

  4. Substrate-borne vibratory communication during courtship in Drosophila melanogaster.

    PubMed

    Fabre, Caroline C G; Hedwig, Berthold; Conduit, Graham; Lawrence, Peter A; Goodwin, Stephen F; Casal, José

    2012-11-20

    Courtship in Drosophila melanogaster has become an iconic example of an innate and interactive series of behaviors. The female signals her acceptance of copulation by becoming immobile in response to a male's display of stereotyped actions. The male and female communicate via vision, air-borne sounds, and pheromones, but what triggers the female's immobility is undetermined. Here, we describe an overlooked and important component of Drosophila courtship. Video recordings and laser vibrometry show that the male abdomen shakes ("quivers"), generating substrate-borne vibrations at about six pulses per second. We present evidence that the female becomes receptive and stops walking because she senses these vibrations, rather than as a response to air-borne songs produced by the male fluttering the wings. We also present evidence that the neural circuits expressing the sex-determination genes fruitless and doublesex drive quivering behavior. These abdominal quivers and associated vibrations, as well as their effect on female receptivity, are conserved in other Drosophila species. Substrate-borne vibrations are an ancient form of communication that is widespread in animals. Our findings in Drosophila open a door to study the neuromuscular circuitry responsible for these signals and the sensory systems needed for their reception. PMID:23103187

  5. Soluble proteins of chemical communication: an overview across arthropods

    PubMed Central

    Pelosi, Paolo; Iovinella, Immacolata; Felicioli, Antonio; Dani, Francesca R.

    2014-01-01

    Detection of chemical signals both in insects and in vertebrates is mediated by soluble proteins, highly concentrated in olfactory organs, which bind semiochemicals and activate, with still largely unknown mechanisms, specific chemoreceptors. The same proteins are often found in structures where pheromones are synthesized and released, where they likely perform a second role in solubilizing and delivering chemical messengers in the environment. A single class of soluble polypeptides, called Odorant-Binding Proteins (OBPs) is known in vertebrates, while two have been identified in insects, OBPs and CSPs (Chemosensory Proteins). Despite their common name, OBPs of vertebrates bear no structural similarity with those of insects. We observed that in arthropods OBPs are strictly limited to insects, while a few members of the CSP family have been found in crustacean and other arthropods, where however, based on their very limited numbers, a function in chemical communication seems unlikely. The question we address in this review is whether another class of soluble proteins may have been adopted by other arthropods to perform the role of OBPs and CSPs in insects. We propose that lipid-transporter proteins of the Niemann-Pick type C2 family could represent likely candidates and report the results of an analysis of their sequences in representative species of different arthropods. PMID:25221516

  6. Mating behaviour and vibratory signalling in non-hearing cave crickets reflect primitive communication of Ensifera.

    PubMed

    Stritih, Nataša; Čokl, Andrej

    2012-01-01

    In Ensifera, the lack of well-supported phylogeny and the focus on acoustic communication of the terminal taxa hinders understanding of the evolutionary history of their signalling behaviour and the related sensory structures. For Rhaphidophoridae, the most relic of ensiferans following morphology-based phylogenies, the signalling modes are still unknown. Together with a detailed description of their mating process, we provide evidence on vibratory signalling for the sympatric European species Troglophilus neglectus and T. cavicola. Despite their temporal shift in reproduction, the species' behaviours differ significantly. Signalling by abdominal vibration constitutes an obligatory part of courtship in T. neglectus, while it is absent in T. cavicola. Whole-body vibration is expressed after copulation in both species. While courtship signalling appears to stimulate females for mating, the function of post-copulation signals remains unclear. Mating and signalling of both species were found to take place in most cases on bark, and less frequently on other available substrates, like moss and rock. The signals' frequency spectra were substrate dependent, but with the dominant peak always expressed below 120 Hz. On rock, the intensity of T. neglectus courtship signals was below the species' physiological detection range, presumably constraining the evolution of such signalling in caves. The species' behavioural divergence appears to reflect their divergent mating habitats, in and outside caves. We propose that short-range tremulation signalling in courtship, such as is expressed by T. neglectus, represents the primitive mode and context of mechanical signalling in Ensifera. The absence of high-frequency components in the signals may be related to the absence of the crista acoustica homologue (CAH) in the vibratory tibial organ of Rhaphidophoridae. This indirectly supports the hypothesis proposing that the CAH, as an evolutionary precursor of the ear, evolved in Ensifera

  7. ELF communications system ecological monitoring program: Soil arthropods and earthworms

    NASA Astrophysics Data System (ADS)

    Snider, Richard J.; Snider, Renate M.

    1995-04-01

    Based on analysis of years grouped by pre-ELF and operational periods, density fluctuations of arthropods (Collembola and mites) were, in some taxa, significantly different between sites; in others, differences between year groups were significant within either of the study sites. No consistent patterns were seen at the level of species or higher taxa. In some species, effects of the 1988 drought may have carried over into 1989, the first year of antenna operation. Surface-active Collembola, velvet mites and carabid beetles did not alter their activity patterns following antenna activation (e.g., species predominantly spring-active remained spring-active). Although analyses routinely yielded significant differences with respect to total numbers captured in Test and Control, numbers alone were found to be unreliable estimators for disturbance, because a variety of potentially important factors other than EM fields were present. Weekly changes in relative numbers captured, however, showed that increases and decreases in activity were synchronous in the study sites. Carabid beetle activity, which is highly seasonal and governed mainly by reproductive processes, was not affected by EM fields.

  8. Temporal processing of vibratory communication signals at the level of ascending interneurons in Nezara viridula (Hemiptera: Pentatomidae).

    PubMed

    Zorović, Maja

    2011-01-01

    During mating, males and females of N. viridula (Heteroptera: Pentatomidae) produce sex- and species-specific calling and courtship substrate-borne vibratory signals, grouped into songs. Recognition and localization of these signals are fundamental for successful mating. The recognition is mainly based on the temporal pattern, i.e. the amplitude modulation, while the frequency spectrum of the signals usually only plays a minor role. We examined the temporal selectivity for vibratory signals in four types of ascending vibratory interneurons in N. viridula. Using intracellular recording and labelling technique, we analyzed the neurons' responses to 30 pulse duration/interval duration (PD/ID) combinations. Two response arrays were created for each neuron type, showing the intensity of the responses either as time-averaged spike counts or as peak instantaneous spike rates. The mean spike rate response arrays showed preference of the neurons for short PDs (below 600 ms) and no selectivity towards interval duration; while the peak spike rate response arrays exhibited either short PD/long ID selectivity or no selectivity at all. The long PD/short ID combinations elicited the weakest responses in all neurons tested. No response arrays showed the receiver preference for either constant period or duty cycle. The vibratory song pattern selectivity matched the PD of N. viridula male vibratory signals, thus pointing to temporal filtering for the conspecific vibratory signals already at level of the ascending interneurons. In some neurons the responses elicited by the vibratory stimuli were followed by distinct, regular oscillations of the membrane potential. The distance between the oscillation peaks matched the temporal structure of the male calling song, indicating a possible resonance based mechanism for signal recognition. PMID:22053216

  9. Temporal Processing of Vibratory Communication Signals at the Level of Ascending Interneurons in Nezara viridula (Hemiptera: Pentatomidae)

    PubMed Central

    Zorović, Maja

    2011-01-01

    During mating, males and females of N. viridula (Heteroptera: Pentatomidae) produce sex- and species-specific calling and courtship substrate-borne vibratory signals, grouped into songs. Recognition and localization of these signals are fundamental for successful mating. The recognition is mainly based on the temporal pattern, i.e. the amplitude modulation, while the frequency spectrum of the signals usually only plays a minor role. We examined the temporal selectivity for vibratory signals in four types of ascending vibratory interneurons in N. viridula. Using intracellular recording and labelling technique, we analyzed the neurons' responses to 30 pulse duration/interval duration (PD/ID) combinations. Two response arrays were created for each neuron type, showing the intensity of the responses either as time-averaged spike counts or as peak instantaneous spike rates. The mean spike rate response arrays showed preference of the neurons for short PDs (below 600 ms) and no selectivity towards interval duration; while the peak spike rate response arrays exhibited either short PD/long ID selectivity or no selectivity at all. The long PD/short ID combinations elicited the weakest responses in all neurons tested. No response arrays showed the receiver preference for either constant period or duty cycle. The vibratory song pattern selectivity matched the PD of N. viridula male vibratory signals, thus pointing to temporal filtering for the conspecific vibratory signals already at level of the ascending interneurons. In some neurons the responses elicited by the vibratory stimuli were followed by distinct, regular oscillations of the membrane potential. The distance between the oscillation peaks matched the temporal structure of the male calling song, indicating a possible resonance based mechanism for signal recognition. PMID:22053216

  10. Arthropod Genetics.

    ERIC Educational Resources Information Center

    Zumwalde, Sharon

    2000-01-01

    Introduces an activity on arthropod genetics that involves phenotype and genotype identification of the creature and the construction process. Includes a list of required materials and directions to build a model arthropod. (YDS)

  11. Agonistic signals received by an arthropod filiform hair allude to the prevalence of near-field sound communication

    PubMed Central

    Santer, Roger D; Hebets, Eileen A

    2007-01-01

    Arthropod filiform hairs respond to air particle movements and are among the most sensitive animal sensory organs. In many species, they are tuned to detect predators or prey and trigger escape or prey capture behaviours. Here we show for the first time that these hairs also receive intraspecific near-field sound signals in an arachnid. During agonistic encounters, whip spiders (Arachnida, Amblypygi) perform antenniform leg vibration (ALV) displays that have significantly longer duration in contest winners than losers. During an ALV display: (i) the vibrating antenniform leg of the displaying whip spider is positioned close to the trichobothria (filiform hairs) on its opponent's walking legs, (ii) the vibrating antenniform leg can excite these trichobothria via air movements and without direct contact, (iii) the antenniform leg of the displaying whip spider vibrates at a frequency that causes particularly strong, sustained excitation and little adaptation in the trichobothria, and (iv) the duration of an ALV display can be extracted from the response of a trichobothrium. Since filiform hairs are widespread among arthropods, communication via such hairs could be extremely prevalent. PMID:18055386

  12. Agonistic signals received by an arthropod filiform hair allude to the prevalence of near-field sound communication.

    PubMed

    Santer, Roger D; Hebets, Eileen A

    2008-02-22

    Arthropod filiform hairs respond to air particle movements and are among the most sensitive animal sensory organs. In many species, they are tuned to detect predators or prey and trigger escape or prey capture behaviours. Here we show for the first time that these hairs also receive intraspecific near-field sound signals in an arachnid. During agonistic encounters, whip spiders (Arachnida, Amblypygi) perform antenniform leg vibration (ALV) displays that have significantly longer duration in contest winners than losers. During an ALV display: (i) the vibrating antenniform leg of the displaying whip spider is positioned close to the trichobothria (filiform hairs) on its opponent's walking legs, (ii) the vibrating antenniform leg can excite these trichobothria via air movements and without direct contact, (iii) the antenniform leg of the displaying whip spider vibrates at a frequency that causes particularly strong, sustained excitation and little adaptation in the trichobothria, and (iv) the duration of an ALV display can be extracted from the response of a trichobothrium. Since filiform hairs are widespread among arthropods, communication via such hairs could be extremely prevalent. PMID:18055386

  13. Advanced turboprop vibratory characteristics

    NASA Technical Reports Server (NTRS)

    Srinivasan, A. V.; Fulton, G. B.

    1984-01-01

    The assembly of SR5 advanced turboprop blades to develop a structural dynamic data base for swept props is reported. Steady state blade deformation under centrifugal loading and vibratory characteristics of the rotor assembly were measured. Vibration was induced through a system of piezoelectric crystals attached to the blades. Data reduction procedures are used to provide deformation, mode shape, and frequencies of the assembly at predetermined speeds.

  14. Vibratory gyroscopic sensors

    NASA Astrophysics Data System (ADS)

    Fox, C. H. J.; Hardie, D. J. W.

    The paper describes the principles of operation of vibratory gyroscopic sensors based on simple oscillators, balanced oscillators, and vibrating shells with particular emphasis on the third type. Error mechanisms are discussed and the relative merits of the three types are considered leading to the conclusion that vibrating shell sensors offer substantial advantages over the other types in terms of their immunity to external vibration and the relatively weak interaction between the basic sensing vibration of the shell and the instrument mounting.

  15. VIBRATORY SPIRAL BLANCHER-COOLER

    EPA Science Inventory

    The objective of the demonstration project was to test the commercial feasibility of the vibratory spiral blancher-cooler, a newly designed steam blancher and air cooler that previous small scale tests showed could reduce the wasteload and energy consumption of preparing vegetabl...

  16. Vibratory tactile display for textures

    NASA Technical Reports Server (NTRS)

    Ikei, Yasushi; Ikeno, Akihisa; Fukuda, Shuichi

    1994-01-01

    We have developed a tactile display that produces vibratory stimulus to a fingertip in contact with a vibrating tactor matrix. The display depicts tactile surface textures while the user is exploring a virtual object surface. A piezoelectric actuator drives the individual tactor in accordance with both the finger movement and the surface texture being traced. Spatiotemporal display control schemes were examined for presenting the fundamental surface texture elements. The temporal duration of vibratory stimulus was experimentally optimized to simulate the adaptation process of cutaneous sensation. The selected duration time for presenting a single line edge agreed with the time threshold of tactile sensation. Then spatial stimulus disposition schemes were discussed for representation of other edge shapes. As an alternative means not relying on amplitude control, a method of augmented duration at the edge was investigated. Spatial resolution of the display was measured for the lines presented both in perpendicular and parallel to a finger axis. Discrimination of texture density was also measured on random dot textures.

  17. GEC Ferranti piezo vibratory gyroscope

    NASA Technical Reports Server (NTRS)

    Nuttall, J. D.

    1993-01-01

    Prototypes of a piezo-electric vibratory angular rate transducer (gyroscope) (PVG) have been constructed and evaluated. The construction is on the lines suggested by Burdess. The sensitive element is a cylinder of radially poled piezo-electric ceramic. The cylinder is metallized inside and out, and the outer metallization is divided into eight electrodes. The metallization on the inside is earthed. A phase locked loop, using pairs of the electrodes, causes the cylinder to vibrate in one of its two fundamental, degenerate modes. In the presence of rotation, some of the vibration is coupled into the outer mode. This can be detected, or suppressed with a closed-up technique and provides a measure of rotation rate. The gyroscope provides a number of advantages over rotating mass and optical instruments: low size and mass, lower power consumption, potentially high reliability, potentially good dormancy, low cost and high maximum rate.

  18. Snoring-Induced Vibratory Angioedema

    PubMed Central

    Kalathoor, Ipe

    2015-01-01

    Patient: Female, 70 Final Diagnosis: Snoring induced vibratory angioedema Symptoms: Swelling of tongue • roof of mouth and throat • multiple episodes at night Medication: — Clinical Procedure: Continuous positive airway pressure therapy Specialty: Allergology Objective: Rare disease Background: Vibratory angioedema (VA) is a rare physical urticaria, with symptoms of itching and swelling of the skin or mucosa when it is exposed to vibration. Avoidance of vibration is the best way to manage this condition. This case report will assist physicians to diagnose this rare condition. Here, a previously unpublished potential successful treatment modality is being presented, with good symptom control, along with some photographs taken during an acute attack. A literature review points towards potential undiagnosed cases. Case Report: A 70-year-old woman had multiple emergency department visits for tongue and throat swelling over 3 years. The episodes always happened at night. Detailed history elicited some episodes of itching and swelling of hands when driving as well as significant snoring while sleeping. Physical examination was unremarkable except for morbid obesity. Complement factor 4 and C1esterase inhibitor level were within normal limits. A tentative diagnosis of angioedema induced by oropharyngeal vibration from snoring was made. A sleep study confirmed sleep apnea with severe snoring. After CPAP (continuous positive airway pressure) treatment, she had successful symptom control. Conclusions: Snoring-induced VA is very likely an under-diagnosed condition in the community. The typical history is the key to the diagnosis. This condition could be confirmed by vibration test or by the resolution of symptoms with elimination of vibration. Effective symptom control is possible by avoidance of oropharyngeal vibration from snoring with the administration of CPAP therapy, making it a potential novel indication for this condition. PMID:26437464

  19. A novel acoustic-vibratory multimodal duet.

    PubMed

    Rajaraman, Kaveri; Godthi, Vamsy; Pratap, Rudra; Balakrishnan, Rohini

    2015-10-01

    The communication strategy of most crickets and bushcrickets typically consists of males broadcasting loud acoustic calling songs, while females perform phonotaxis, moving towards the source of the call. Males of the pseudophylline bushcricket species Onomarchus uninotatus produce an unusually low-pitched call, and we found that the immediate and most robust response of females to the male acoustic call was a bodily vibration, or tremulation, following each syllable of the call. We hypothesized that these bodily oscillations might send out a vibrational signal along the substrate on which the female stands, which males could use to localize her position. We quantified these vibrational signals using a laser vibrometer and found a clear phase relationship of alternation between the chirps of the male acoustic call and the female vibrational response. This system therefore constitutes a novel multimodal duet with a reliable temporal structure. We also found that males could localize the source of vibration but only if both the acoustic and vibratory components of the duet were played back. This unique multimodal duetting system may have evolved in response to higher levels of bat predation on searching bushcricket females than calling males, shifting part of the risk associated with partner localization onto the male. This is the first known example of bushcricket female tremulation in response to a long-range male acoustic signal and the first known example of a multimodal duet among animals. PMID:26254322

  20. Non-inertial calibration of vibratory gyroscopes

    NASA Technical Reports Server (NTRS)

    Gutierrez, Roman C. (Inventor); Tang, Tony K. (Inventor)

    2003-01-01

    The electrostatic elements already present in a vibratory gyroscope are used to simulate the Coriolis forces. An artificial electrostatic rotation signal is added to the closed-loop force rebalance system. Because the Coriolis force is at the same frequency as the artificial electrostatic force, the simulated force may be introduced into the system to perform an inertial test on MEMS vibratory gyroscopes without the use of a rotation table.

  1. Vibratory finishing as a decontamination process

    SciTech Connect

    McCoy, M.W.; Arrowsmith, H.W.; Allen, R.P.

    1980-10-01

    The major objective of this research is to develop vibratory finishing into a large-scale decontamination technique that can economicaly remove transuranic and other surface contamination from large volumes of waste produced by the operation and decommissioning of retired nuclear facilities. The successful development and widespread application of this decontamination technique would substantially reduce the volume of waste requiring expensive geologic disposal. Other benefits include exposure reduction for decontamination personnel and reduced risk of environmental contamination. Laboratory-scale studies showed that vibratory finishing can rapidly reduce the contamination level of transuranic-contaminated stainless steel and Plexiglas to well below the 10-nCi/g limit. The capability of vibratory finishing as a decontamination process was demonstrated on a large scale. The first decontamination demonstration was conducted at the Hanford N-Reactor, where a vibratory finisher was installed to reduce personnel exposure during the summer outage. Items decontaminated included fuel spacers, process-tube end caps, process-tube inserts, pump parts, ball-channel inspection tools and miscellaneous hand tools. A second demonstration is currently being conducted in the decontamination facility at the Hanford 231-Z Building. During this demonstration, transuranic-contaminated material from decommissioned plutonium facilities is being decontaminated to <10 nCi/g to minimize the volume of material that will require geologic disposal. Items that are being decontaminated include entire glove boxes, process-hood structural material and panels, process tanks, process-tank shields, pumps, valves and hand tools used during the decommissioning work.

  2. Arthropods in Biological Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article reports the use of insect colloidal artificial diets suitable for the rearing of economically important arthropods, such as Lygus lineolaris, Lygus hesperus, Coleomegilla maculata, and Phytoseiulus persimilis The different diets contain key nutrients such as proteins, carbohydrates, vi...

  3. Cloverleaf Vibratory Microgyroscope with Integrated Post

    NASA Technical Reports Server (NTRS)

    Tang, Tony K.; Gutierrez, Roman; Roger, Damien

    2003-01-01

    A modified design and fabrication sequence has been devised to improve the performance of a cloverleaf vibratory microgyroscope that includes an axial rod or post rigidly attached to the center of the cloverleaf structure. The basic concepts of cloverleaf vibratory microgyroscopes, without and with rods or posts, were described in two prior articles in NASA Tech Briefs, Vol. 21, No. 9 (September 1997): Micromachined Planar Vibratory Microgyroscopes (NPO-19713), page 68 and Planar Vibratory Microgyroscope: Alternative Configuration (NPO-19714), page 70. As described in more detail in the second-mentioned prior article, the cloverleaf-shaped structure and the rod or post are parts of a vibratory element that senses rotation via the effect of the Coriolis force upon its vibrations. Heretofore, the posts for devices of this type have been fabricated separately, then assembled manually onto the cloverleaf structures. The resulting imperfections in the assembled units have given rise to asymmetric stresses in the cloverleaf structures and, consequently, to changes in resonant frequencies of vibration and in shapes of vibration modes. These changes, in turn, have caused variations in performance among nominally identical devices. The modified design provides for the fabrication of the upper half of the post as an integral part of the cloverleaf structure; this is accomplished by reactive-ion etching of a single-piece half-post-and-cloverleaf structure from a wafer of silicon. The lower half of the post and a baseplate are also a single piece made by reactive-ion etching from a wafer of silicon. The two pieces are bonded together (see figure) by a thermal-compression metal-to-metal bonding technique to form a cloverleaf gyroscope with an integrated post structure..

  4. Vibratory pumping of a free fluid stream

    DOEpatents

    Merrigan, M.A.; Woloshun, K.A.

    1990-11-13

    A vibratory fluid pump is described having a force generator for generating asymmetric periodic waves or oscillations connected to one end of one or more fluid conveyance means, such as filaments. The opposite ends of the filaments are connected to springs. Fluid introduced onto the filaments will traverse along the filaments according to the magnitude of the positive and negative excursions of the periodic waves or oscillations, and can be recovered from the filaments. 3 figs.

  5. Vibratory pumping of a free fluid stream

    DOEpatents

    Merrigan, Michael A.; Woloshun, Keith A.

    1990-01-01

    A vibratory fluid pump having a force generator for generating asymmetric periodic waves or oscillations connected to one end of one or more fluid conveyance means, such as filaments. The opposite ends of the filaments are connected to springs. Fluid introduced onto the filaments will traverse along the filaments according to the magnitude of the positive and negative excursions of the periodic waves or oscillations, and can be recovered from the filaments.

  6. Continuous Tuning and Calibration of Vibratory Gyroscopes

    NASA Technical Reports Server (NTRS)

    Hayworth, Ken

    2003-01-01

    A method of control and operation of an inertial reference unit (IRU) based on vibratory gyroscopes provides for continuously repeated cycles of tuning and calibration. The method is intended especially for application to an IRU containing vibratory gyroscopes that are integral parts of microelectromechanical systems (MEMS) and that have cloverleaf designs, as described in several previous NASA Tech Briefs articles. The method provides for minimization of several measures of spurious gyroscope output, including zero-rate offset (ZRO), angle random walk (ARW), and rate drift. These benefits are afforded both at startup and thereafter during continuing operation, in the presence of unknown rotation rates and changes in temperature. A vibratory gyroscope contains a precision mechanically resonant structure containing two normal modes of vibration nominally degenerate in frequency and strongly coupled via a Coriolis term. In the case of the cloverleaf design MEMS gyro, these normal modes of vibration are plate rocking modes. The rocking motion of the plate is described by giving two angles, theta(sub 1) and theta(sub 2). A proof mass consisting of a post orthogonal to the plate ensures a high degree of Coriolis coupling of vibratory energy from one mode into the other under inertial rotation. The plate is driven and sensed capacitively across a few-microns-wide gap, and the normal mode frequencies can be tuned electrostatically by DC voltages applied across this gap. In order to sense rotation, the resonator plate is caused to rock in the theta(sub 1) direction, then any small motions in the theta(sub 2) direction are sensed, rebalanced, and interpreted as inertial rotation. In this scenario, the "drive" has been assigned to the theta(sub 1) direction, and the "sense" has been assigned to the theta(sub 2) direction.

  7. Vibratory Regime Classification of Infant Phonation

    PubMed Central

    Buder, Eugene H.; Chorna, Lesya B.; Oller, D. Kimbrough; Robinson, Rebecca B.

    2008-01-01

    Infant phonation is highly variable in many respects, including the basic vibratory patterns by which the vocal tissues create acoustic signals. Previous studies have identified the regular occurrence of non-modal phonation types in normal infant phonation. The glottis is like many oscillating systems that, because of non-linear relationships among the elements, may vibrate in ways representing the deterministic patterns classified theoretically within the mathematical framework of non-linear dynamics. The infant’s pre-verbal vocal explorations present such a variety of phonations that it may be possible to find effectively all the classes of vibration predicted by non-linear dynamic theory. The current report defines acoustic criteria for an important subset of such vibratory regimes, and demonstrates that analysts can be trained to reliably use these criteria for a classification that includes all instances of infant phonation in the recorded corpora. The method is thus internally comprehensive in the sense that all phonations are classified, but it is not exhaustive in the sense that all vocal qualities are thereby represented. Using the methods thus developed, this study also demonstrates that the distributions of these phonation types vary significantly across sessions of recording in the first year of life, suggesting developmental changes. The method of regime classification is thus capable of tracking changes that may be indicative of maturation of the mechanism, the learning of categories of phonatory control, and the possibly varying use of vocalizations across social contexts. PMID:17509829

  8. Making Precise Resonators for Mesoscale Vibratory Gyroscopes

    NASA Technical Reports Server (NTRS)

    Yang, Eui-Hyeok

    2004-01-01

    An alternative approach to the design and fabrication of vibratory gyroscopes is founded on the use of fabrication techniques that yield best results in the mesoscopic size range, which is characterized by overall device dimensions of the order of a centimeter. This approach stands in contradistinction to prior approaches in (1) the macroscopic size range (the size range of conventional design and fabrication, characterized by overall device dimensions of many centimeters) and (2) the microscopic size range [the size range of microelectromechanical systems (MEMS), characterized by overall device dimensions of the order of a millimeter or less]. The mesoscale approach offers some of the advantage of the MEMS approach (sizes and power demands smaller than those of the macroscale approach) and some of the advantage of the macroscale approach (the possibility of achieving relative dimensional precision greater than that of the MEMS approach). Relative dimensional precision is a major issue in the operation of a vibratory gyroscope. The heart of a vibratory gyroscope is a mechanical resonator that is required to have a specified symmetry in a plane orthogonal to the axis about which rotation is to be measured. If the resonator could be perfectly symmetrical, then in the absence of rotation, a free vibration of the resonator could remain fixed along any orientation relative to its housing; that is, the gyroscope could exhibit zero drift. In practice, manufacturing imprecision gives rise to some asymmetry in mass, flexural stiffness or dissipation, resulting in a slight drift or beating motion of an initial vibration pattern that cannot be distinguished from rotation. In the mesoscale approach, one exploits the following concepts: For a given amount of dimensional error generated in manufacturing, the asymmetry and hence the rate-of-rotation drift of the gyroscope can be reduced by increasing the scale. The decrease in asymmetry also reduces coupling of vibrations to the

  9. Parametrically disciplined operation of a vibratory gyroscope

    NASA Technical Reports Server (NTRS)

    Shcheglov, Kirill V. (Inventor); Hayworth, Ken J. (Inventor); Challoner, A. Dorian (Inventor); Peay, Chris S. (Inventor)

    2008-01-01

    Parametrically disciplined operation of a symmetric nearly degenerate mode vibratory gyroscope is disclosed. A parametrically-disciplined inertial wave gyroscope having a natural oscillation frequency in the neighborhood of a sub-harmonic of an external stable clock reference is produced by driving an electrostatic bias electrode at approximately twice this sub-harmonic frequency to achieve disciplined frequency and phase operation of the resonator. A nearly symmetric parametrically-disciplined inertial wave gyroscope that can oscillate in any transverse direction and has more than one bias electrostatic electrode that can be independently driven at twice its oscillation frequency at an amplitude and phase that disciplines its damping to zero in any vibration direction. In addition, operation of a parametrically-disciplined inertial wave gyroscope is taught in which the precession rate of the driven vibration pattern is digitally disciplined to a prescribed non-zero reference value.

  10. Fast Laser Shutters With Low Vibratory Disturbances

    NASA Technical Reports Server (NTRS)

    Brinza, David; Moore, Donald; Hochberg, Eric; Radey, Tom; Chen, Albert

    2005-01-01

    A prototype vacuum-compatible, fast-acting, long-life shutter unit that generates very little vibratory disturbance during switching is reviewed. This is one of a number of shutters designed to satisfy requirements specific to an experiment, to be performed aboard a spacecraft in flight, in which laser beams must be blocked rapidly and completely, without generating a vibratory disturbance large enough to adversely affect the power and frequency stability of the lasers. Commercial off-the-shelf laboratory shutter units -- typically containing electromagnet-coil-driven mechanisms -- were found not to satisfy the requirements because they are not vacuum-compatible, their actuators engage in uncompensated motions that generate significant vibrations, and their operational lifetimes are too short. Going beyond the initial outerspace application, the present vacuum-compatible, fast-acting, long-life shutter units could also be used in terrestrial settings in which there are requirements for their special characteristics. In designing these shutter units, unbalanced, electromagnetically driven mechanisms were replaced with balanced mechanisms that include commercial piezoelectric bending actuators. In each shutter unit, the piezoelectric bending actuators are configured symmetrically as opposing cantilever beams within a housing that contains integral mounts for lenses that focus a laser beam to a waist at the shutter location. In operation, the laser beam is blocked by titanium blades bonded near the free ends of the piezoelectric benders. The benders are driven by shaped electrical pulses with a maximum voltage differential of less than 60 V. Preliminary measurements indicate that rise and fall times are less than 1 ms.

  11. Methane production in terrestrial arthropods.

    PubMed Central

    Hackstein, J H; Stumm, C K

    1994-01-01

    We have screened more than 110 representatives of the different taxa of terrestrial arthropods for methane production in order to obtain additional information about the origins of biogenic methane. Methanogenic bacteria occur in the hindguts of nearly all tropical representatives of millipedes (Diplopoda), cockroaches (Blattaria), termites (Isoptera), and scarab beetles (Scarabaeidae), while such methanogens are absent from 66 other arthropod species investigated. Three types of symbiosis were found: in the first type, the arthropod's hindgut is colonized by free methanogenic bacteria; in the second type, methanogens are closely associated with chitinous structures formed by the host's hindgut; the third type is mediated by intestinal anaerobic protists with intracellular methanogens. Such symbiotic associations are likely to be a characteristic property of the particular taxon. Since these taxa represent many families with thousands of species, the world populations of methane-producing arthropods constitute an enormous biomass. We show that arthropod symbionts can contribute substantially to atmospheric methane. Images PMID:8202505

  12. Methane production in terrestrial arthropods

    SciTech Connect

    Hackstein, J.H.P.; Stumm, C.K. )

    1994-06-07

    The authors have screened more than 110 representatives of the different taxa of terrestrial arthropods for methane production in order to obtain additional information about the origins of biogenic methane. Methanogenic bacteria occur in the hindguts of nearly all tropical representatives of millipedes (Diplopoda), cockroaches (Blattaria), termites (Isoptera), and scarab beetles (Scarabaeidae), while such methanogens are absent from 66 other arthropod species investigated. Three types of symbiosis were found: in the first type, the arthropod's hindgut is colonized by free methanogenic bacteria; in the second type, methanogens are closely associated with chitinous structures formed by the host's hindgut; the third type is mediated by intestinal anaerobic protists with intracellular methanogens. Such symbiotic associations are likely to be a characteristic property of the particular taxon. Since these taxa represent many families with thousands of species, the world populations of methane-producing arthropods constitute an enormous biomass. The authors show that arthropod symbionts can contribute substantially to atmospheric methane.

  13. Vertical-plane pendulum absorbers for minimizing helicopter vibratory loads

    NASA Technical Reports Server (NTRS)

    Amer, K. B.; Neff, J. R.

    1974-01-01

    The use of pendulum dynamic absorbers mounted on the blade root and operating in the vertical plane to minimize helicopter vibratory loads was discussed. A qualitative description was given of the concept of the dynamic absorbers and some results of analytical studies showing the degree of reduction in vibratory loads attainable are presented. Operational experience of vertical plane dynamic absorbers on the OH-6A helicopter is also discussed.

  14. Morphology and physiology of vibratory interneurons in the thoracic ganglia of the southern green stinkbug Nezara viridula (L.).

    PubMed

    Zorović, Maja; Presern, Janez; Cokl, Andrej

    2008-05-10

    The central processing mechanisms of vibratory signals in small plant-dwelling insects that rely primarily on substrate-borne vibratory communication are still largely unknown. To elucidate the neural mechanisms involved in vibratory signaling, the vibration-sensitive interneurons in thoracic ganglia of the southern green stinkbug, Nezara viridula, were investigated electrophysiologically by single-cell recordings and staining. Ten types of interneurons were described and divided into four categories, based on their gross morphology. The cell body of the L-shaped CG-AC neurons is located in the metathoracic neuromere of the central ganglion, and the axon ascends contralaterally. This group comprises five types of neurons differing in their fine structure and functional properties. CG-AB neurons are dorsal unpaired median (DUM) neurons with cell bodies in the mesothoracic neuromere of the central ganglion and two axons that ascend bilaterally into the prothoracic ganglion. Group CG-L includes three types of local neurons limited to the central ganglion. With ipsilateral dendritic arborizations and contralateral axonal branching, their gross morphology is similar to that of cricket omega cells. Interneuron PTG-DC, with the cell body in the prothoracic ganglion (PTG) and a contralaterally descending axon, conveys information received by the sensory organs of the front contralateral leg to the neuropil regions of the ipsilateral middle and hind legs. Based on their frequency tuning and acceleration sensitivity, the vibratory interneurons fall into two groups: the low-frequency units are tuned to 50 Hz and the middle frequency units to 200 Hz, with their acceleration thresholds at 10(-1) m/s(2) and 5 x 10(-3) m/s(2), respectively. Their function is discussed with relevance to the vibratory communication of N. viridula. PMID:18335563

  15. Household Arthropod Allergens in Korea

    PubMed Central

    Jeong, Kyoung Yong

    2009-01-01

    Arthropods are important in human health, which can transmit pathogens to humans, parasitize, or produce important allergens. Allergy prevalence becomes higher in Korea recently as well as other developed countries in contrast to a decrease of infectious diseases. Allergic diseases caused by household arthropods have increased dramatically during the last few decades since human beings spend more their time for indoor activities in modernized life style. Household arthropods are one of the most common causes of allergic diseases. Biological characterization of household arthropods and researches on their allergens will provide better understanding of the pathogenesis of allergic diseases and suggest new therapeutic ways. Therefore, studies on arthropods of allergenic importance can be considered one of the major research areas in medical arthropodology and parasitology. Here, the biology of several household arthropods, including house dust mites and cockroaches, the 2 most well known arthropods living indoor together with humans worldwide, and characteristics of their allergens, especially the research activities on these allergens performed in Korea, are summarized. PMID:19885330

  16. Laboratory Identification of Arthropod Ectoparasites

    PubMed Central

    Pritt, Bobbi S.

    2014-01-01

    SUMMARY The collection, handling, identification, and reporting of ectoparasitic arthropods in clinical and reference diagnostic laboratories are discussed in this review. Included are data on ticks, mites, lice, fleas, myiasis-causing flies, and bed bugs. The public health importance of these organisms is briefly discussed. The focus is on the morphological identification and proper handling and reporting of cases involving arthropod ectoparasites, particularly those encountered in the United States. Other arthropods and other organisms not of public health concern, but routinely submitted to laboratories for identification, are also briefly discussed. PMID:24396136

  17. Laboratory identification of arthropod ectoparasites.

    PubMed

    Mathison, Blaine A; Pritt, Bobbi S

    2014-01-01

    The collection, handling, identification, and reporting of ectoparasitic arthropods in clinical and reference diagnostic laboratories are discussed in this review. Included are data on ticks, mites, lice, fleas, myiasis-causing flies, and bed bugs. The public health importance of these organisms is briefly discussed. The focus is on the morphological identification and proper handling and reporting of cases involving arthropod ectoparasites, particularly those encountered in the United States. Other arthropods and other organisms not of public health concern, but routinely submitted to laboratories for identification, are also briefly discussed. PMID:24396136

  18. Complex vibratory patterns in an elephant larynx.

    PubMed

    Herbst, Christian T; Svec, Jan G; Lohscheller, Jörg; Frey, Roland; Gumpenberger, Michaela; Stoeger, Angela S; Fitch, W Tecumseh

    2013-11-01

    Elephants' low-frequency vocalizations are produced by flow-induced self-sustaining oscillations of laryngeal tissue. To date, little is known in detail about the vibratory phenomena in the elephant larynx. Here, we provide a first descriptive report of the complex oscillatory features found in the excised larynx of a 25 year old female African elephant (Loxodonta africana), the largest animal sound generator ever studied experimentally. Sound production was documented with high-speed video, acoustic measurements, air flow and sound pressure level recordings. The anatomy of the larynx was studied with computed tomography (CT) and dissections. Elephant CT vocal anatomy data were further compared with the anatomy of an adult human male. We observed numerous unusual phenomena, not typically reported in human vocal fold vibrations. Phase delays along both the inferior-superior and anterior-posterior (A-P) dimension were commonly observed, as well as transverse travelling wave patterns along the A-P dimension, previously not documented in the literature. Acoustic energy was mainly created during the instant of glottal opening. The vestibular folds, when adducted, participated in tissue vibration, effectively increasing the generated sound pressure level by 12 dB. The complexity of the observed phenomena is partly attributed to the distinct laryngeal anatomy of the elephant larynx, which is not simply a large-scale version of its human counterpart. Travelling waves may be facilitated by low fundamental frequencies and increased vocal fold tension. A travelling wave model is proposed, to account for three types of phenomena: A-P travelling waves, 'conventional' standing wave patterns, and irregular vocal fold vibration. PMID:24133151

  19. Vibratory compaction tests on graphite powders for neutron shielding

    SciTech Connect

    Morgan, W.C.

    1982-05-01

    Mistures of three size ranges of graphite powders have been vibratory packed to densities as high as 1.40 gm/cm/sup 3/, which is 87.5 percent of the design density for the graphte segment of the FMIT test cell shield. Ultrasonic resonance vibration of the particles was determined to be an impractical method for achieving the required density. Possible options for fabricating the shield are: (1) revert to solid graphite, rather than vibratory packed powder, or (2) develop the mechanical vibratory compaction method, which would require (a) designing for the higher heat-load attendant with the reduced graphite density, or (b) increasing the thickness of the graphite segment by 15 percent or (c) seeking a new source of graphite powder with higher particle density.

  20. Analysis of rotor vibratory loads using higher harmonic pitch control

    NASA Technical Reports Server (NTRS)

    Quackenbush, Todd R.; Bliss, Donald B.; Boschitsch, Alexander H.; Wachspress, Daniel A.

    1992-01-01

    Experimental studies of isolated rotors in forward flight have indicated that higher harmonic pitch control can reduce rotor noise. These tests also show that such pitch inputs can generate substantial vibratory loads. The modification is summarized of the RotorCRAFT (Computation of Rotor Aerodynamics in Forward flighT) analysis of isolated rotors to study the vibratory loading generated by high frequency pitch inputs. The original RotorCRAFT code was developed for use in the computation of such loading, and uses a highly refined rotor wake model to facilitate this task. The extended version of RotorCRAFT incorporates a variety of new features including: arbitrary periodic root pitch control; computation of blade stresses and hub loads; improved modeling of near wake unsteady effects; and preliminary implementation of a coupled prediction of rotor airloads and noise. Correlation studies are carried out with existing blade stress and vibratory hub load data to assess the performance of the extended code.

  1. Modifications of Fabrication of Vibratory Microgyroscopes

    NASA Technical Reports Server (NTRS)

    Bae, Sam Y.; Yee, Karl Y.; Wiberg, Dean

    2005-01-01

    A micromachining process for the fabrication of vibratory microgyroscopes from silicon wafers, and aspects of the microgyroscope design that are inextricably linked with the fabrication process, have been modified in an effort to increase production yields from perspectives of both quantity and quality. Prior to the modifications, the effective production yield of working microgyroscopes was limited to one or less per wafer. The modifications are part of a continuing effort to improve the design and increase production yields to more than 30 working microgyroscopes per wafer. A discussion of pertinent aspects of the unmodified design and the unmodified fabrication process is prerequisite to a meaningful description of the modifications. The design of the microgyroscope package was not conducive to high yield and rapid testing of many microgyroscopes. One of the major impediments to high yield and testing was found to lie in vibration- isolation beams around the four edges of each microgyroscope, which beams were found to be unnecessary for achieving high resonance quality factors (Q values) characterizing the vibrations of petallike cantilevers. The fabrication process included an 8- m-deep plasma etch. The purpose of the etch was to create 8- m vertical gaps, below which were to be placed large gold evaporated electrodes and sensing pads to drive and sense resonant vibrations of the "petals." The process also included a step in which bridges between dies were cut to separate the dies. The etched areas must be kept clean and smooth (free of debris and spikes), because any object close to 8 m high in those areas would stop the vibrations. However, it was found that after the etch, there remained some spikes with heights that were, variously, almost as high or as high as the etch depth. It also was found that the cutting of bridges created silicon debris, some of which lodged in the 8- m gaps and some of which landed on top of the petals. The masses added to the

  2. Arthropod use of invertebrate carrion

    SciTech Connect

    Seastedt, T.R.; Mameli, L.; Gridley, K.

    1981-01-01

    Arthropods associated with cricket carcasses placed on top and within deciduous forest litter were collected for 12 months. Vespid wasps and ants quickly removed carcasses left on top of forest litter, but carcasses placed within litter persisted throughout the study. Major consumers of carcasses in litter varied seasonally; maggots dominated on fresh carcasses in summer, but fresh carcasses placed in litter in autumn were consumed by other arthropods. A gamasid mite, Hypoaspis (Laelaspis) johnieae, dominated the microarthropod fauna found on exoskeleton fragments. A method for collecting invertebrate carrion feeders and measuring carrion disappearance is presented. 15 references, 2 tables.

  3. Arthropod use of invertebrate carrion

    SciTech Connect

    Seastedt, T.R.; Mameli, L.; Gridley, K.

    1980-08-01

    Arthropods associated with cricket carcasses placed on top and within deciduous forest litter were collected over a 12 month interval. Vespid wasps and ants quickly removed carcasses left on top of forest litter, but carcasses placed within litter persisted throughout the study. Major consumers of carcasses in litter varied seasonally; maggots dominated on fresh carcasses in summer, but fresh carcasses placed in litter in autumn were consumed by other arthropods. A gamasid mite, Hypoaspis (Laelaspis) johnieae dominated the microarthropod fauna found on exoskeleton fragments. A method for collecting invertebrate carrion feeders and measuring carrion disappearance is presented.

  4. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... viable fetus is desired or anticipated. (b) Classification. Class III (premarket approval). (c) Date PMA or notice of completion of a PDP is required. A PMA or a notice of completion of a PDP is required to... commercial distribution before May 28, 1976. Any other vibratory cervical dilator shall have an approved...

  5. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... viable fetus is desired or anticipated. (b) Classification. Class III (premarket approval). (c) Date PMA or notice of completion of a PDP is required. A PMA or a notice of completion of a PDP is required to... commercial distribution before May 28, 1976. Any other vibratory cervical dilator shall have an approved...

  6. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Vibratory cervical dilators. 884.4270 Section 884.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... be filed with the Food and Drug Administration on or before December 26, 1996 for any...

  7. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Vibratory cervical dilators. 884.4270 Section 884.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... be filed with the Food and Drug Administration on or before December 26, 1996 for any...

  8. 21 CFR 884.4270 - Vibratory cervical dilators.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Vibratory cervical dilators. 884.4270 Section 884.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... be filed with the Food and Drug Administration on or before December 26, 1996 for any...

  9. Carnivorous arthropods after spring flood

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spring flooding is a common practice in Wisconsin cranberries, but flooding as insect control produces variable results among marshes. This project is aimed at figuring out why it works, and why it sometimes doesn’t. We have focused on tracking arthropod populations to explain the observed patterns ...

  10. Vibratory Urticaria Associated with a Missense Variant in ADGRE2.

    PubMed

    Boyden, Steven E; Desai, Avanti; Cruse, Glenn; Young, Michael L; Bolan, Hyejeong C; Scott, Linda M; Eisch, A Robin; Long, R Daniel; Lee, Chyi-Chia R; Satorius, Colleen L; Pakstis, Andrew J; Olivera, Ana; Mullikin, James C; Chouery, Eliane; Mégarbané, André; Medlej-Hashim, Myrna; Kidd, Kenneth K; Kastner, Daniel L; Metcalfe, Dean D; Komarow, Hirsh D

    2016-02-18

    Patients with autosomal dominant vibratory urticaria have localized hives and systemic manifestations in response to dermal vibration, with coincident degranulation of mast cells and increased histamine levels in serum. We identified a previously unknown missense substitution in ADGRE2 (also known as EMR2), which was predicted to result in the replacement of cysteine with tyrosine at amino acid position 492 (p.C492Y), as the only nonsynonymous variant cosegregating with vibratory urticaria in two large kindreds. The ADGRE2 receptor undergoes autocatalytic cleavage, producing an extracellular subunit that noncovalently binds a transmembrane subunit. We showed that the variant probably destabilizes an autoinhibitory subunit interaction, sensitizing mast cells to IgE-independent vibration-induced degranulation. (Funded by the National Institutes of Health.). PMID:26841242

  11. Quantitative phase imaging of arthropods

    NASA Astrophysics Data System (ADS)

    Sridharan, Shamira; Katz, Aron; Soto-Adames, Felipe; Popescu, Gabriel

    2015-11-01

    Classification of arthropods is performed by characterization of fine features such as setae and cuticles. An unstained whole arthropod specimen mounted on a slide can be preserved for many decades, but is difficult to study since current methods require sample manipulation or tedious image processing. Spatial light interference microscopy (SLIM) is a quantitative phase imaging (QPI) technique that is an add-on module to a commercial phase contrast microscope. We use SLIM to image a whole organism springtail Ceratophysella denticulata mounted on a slide. This is the first time, to our knowledge, that an entire organism has been imaged using QPI. We also demonstrate the ability of SLIM to image fine structures in addition to providing quantitative data that cannot be obtained by traditional bright field microscopy.

  12. Quantitative phase imaging of arthropods

    PubMed Central

    Sridharan, Shamira; Katz, Aron; Soto-Adames, Felipe; Popescu, Gabriel

    2015-01-01

    Abstract. Classification of arthropods is performed by characterization of fine features such as setae and cuticles. An unstained whole arthropod specimen mounted on a slide can be preserved for many decades, but is difficult to study since current methods require sample manipulation or tedious image processing. Spatial light interference microscopy (SLIM) is a quantitative phase imaging (QPI) technique that is an add-on module to a commercial phase contrast microscope. We use SLIM to image a whole organism springtail Ceratophysella denticulata mounted on a slide. This is the first time, to our knowledge, that an entire organism has been imaged using QPI. We also demonstrate the ability of SLIM to image fine structures in addition to providing quantitative data that cannot be obtained by traditional bright field microscopy. PMID:26334858

  13. Characterization of the Bell-Shaped Vibratory Angular Rate Gyro

    PubMed Central

    Liu, Ning; Su, Zhong; Li, Qing; Fu, MengYin; Liu, Hong; Fan, JunFang

    2013-01-01

    The bell-shaped vibratory angular rate gyro (abbreviated as BVG) is a novel shell vibratory gyroscope, which is inspired by the Chinese traditional bell. It sensitizes angular velocity through the standing wave precession effect. The bell-shaped resonator is a core component of the BVG and looks like the millimeter-grade Chinese traditional bell, such as QianLong Bell and Yongle Bell. It is made of Ni43CrTi, which is a constant modulus alloy. The exciting element, control element and detection element are uniformly distributed and attached to the resonator, respectively. This work presents the design, analysis and experimentation on the BVG. It is most important to analyze the vibratory character of the bell-shaped resonator. The strain equation, internal force and the resonator's equilibrium differential equation are derived in the orthogonal curvilinear coordinate system. When the input angular velocity is existent on the sensitive axis, an analysis of the vibratory character is performed using the theory of thin shells. On this basis, the mode shape function and the simplified second order normal vibration mode dynamical equation are obtained. The coriolis coupling relationship about the primary mode and secondary mode is established. The methods of the signal processing and control loop are presented. Analyzing the impact resistance property of the bell-shaped resonator, which is compared with other shell resonators using the Finite Element Method, demonstrates that BVG has the advantage of a better impact resistance property. A reasonable means of installation and a prototypal gyro are designed. The gyroscopic effect of the BVG is characterized through experiments. Experimental results show that the BVG has not only the advantages of low cost, low power, long work life, high sensitivity, and so on, but, also, of a simple structure and a better impact resistance property for low and medium angular velocity measurements. PMID:23966183

  14. Characterization of the bell-shaped vibratory angular rate gyro.

    PubMed

    Liu, Ning; Su, Zhong; Li, Qing; Fu, MengYin; Liu, Hong; Fan, JunFang

    2013-01-01

    The bell-shaped vibratory angular rate gyro (abbreviated as BVG) is a novel shell vibratory gyroscope, which is inspired by the Chinese traditional bell. It sensitizes angular velocity through the standing wave precession effect. The bell-shaped resonator is a core component of the BVG and looks like the millimeter-grade Chinese traditional bell, such as QianLong Bell and Yongle Bell. It is made of Ni43CrTi, which is a constant modulus alloy. The exciting element, control element and detection element are uniformly distributed and attached to the resonator, respectively. This work presents the design, analysis and experimentation on the BVG. It is most important to analyze the vibratory character of the bell-shaped resonator. The strain equation, internal force and the resonator's equilibrium differential equation are derived in the orthogonal curvilinear coordinate system. When the input angular velocity is existent on the sensitive axis, an analysis of the vibratory character is performed using the theory of thin shells. On this basis, the mode shape function and the simplified second order normal vibration mode dynamical equation are obtained. The coriolis coupling relationship about the primary mode and secondary mode is established. The methods of the signal processing and control loop are presented. Analyzing the impact resistance property of the bell-shaped resonator, which is compared with other shell resonators using the Finite Element Method, demonstrates that BVG has the advantage of a better impact resistance property. A reasonable means of installation and a prototypal gyro are designed. The gyroscopic effect of the BVG is characterized through experiments. Experimental results show that the BVG has not only the advantages of low cost, low power, long work life, high sensitivity, and so on, but, also, of a simple structure and a better impact resistance property for low and medium angular velocity measurements. PMID:23966183

  15. Deburring die-castings by wet vibratory plant

    NASA Astrophysics Data System (ADS)

    Loeschbart, H. M.

    1980-02-01

    A wet vibratory procedure for the removal of burrs from die castings is described. In this process synthetic abrasive chips and detergent solutions are agitated with the work in such a way as to produce a spiral circulatory movement. Details of various forms of vibrator basin and shapes of abrasive are illustrated. The automation of deburring is illustrated through the application of vibrators of spiral design in combination with transport and drying devices.

  16. Deburring die-castings by wet vibratory plant

    NASA Technical Reports Server (NTRS)

    Loeschbart, H. M.

    1980-01-01

    A wet vibratory procedure for the removal of burrs from die castings is described. In this process synthetic abrasive chips and detergent solutions are agitated with the work in such a way as to produce a spiral circulatory movement. Details of various forms of vibrator basin and shapes of abrasive are illustrated. The automation of deburring is illustrated through the application of vibrators of spiral design in combination with transport and drying devices.

  17. Innovative decontamination technology by abrasion in vibratory vessels

    SciTech Connect

    Fabbri, Silvio; Ilarri, Sergio

    2007-07-01

    Available in abstract form only. Full text of publication follows: The possibility of using conventional vibratory vessel technology as a decontamination technique is the motivation for the development of this project. The objective is to explore the feasibility of applying the vibratory vessel technology for decontamination of radioactively-contaminated materials such as pipes and metal structures. The research and development of this technology was granted by the U.S. Department of Energy (DOE). Abrasion processes in vibratory vessels are widely used in the manufacture of metals, ceramics, and plastics. Samples to be treated, solid abrasive media and liquid media are set up into a vessel. Erosion results from the repeated impact of the abrasive particles on the surface of the body being treated. A liquid media, generally detergents or surfactants aid the abrasive action. The amount of material removed increases with the time of treatment. The design and construction of the machine were provided by Vibro, Argentina private company. Tests with radioactively-contaminated aluminum tubes and a stainless steel bar, were performed at laboratory level. Tests showed that it is possible to clean both the external and the internal surface of contaminated tubes. Results show a decontamination factor around 10 after the first 30 minutes of the cleaning time. (authors)

  18. Knowledge of Arthropod Carnivory and Herbivory: Factors Influencing Preservice Elementary Teacher's Attitudes and Beliefs toward Arthropods

    ERIC Educational Resources Information Center

    Wagler, Ron; Wagler, Amy

    2013-01-01

    Human negativity toward arthropods has been well documented but the factors that contribute to this negativity have been elusive. This study explored knowledge of arthropod carnivory and herbivory as possible casual factors that contribute to the negative tendencies preservice elementary teachers have toward most arthropods. Specifically, this…

  19. Generalized Vibratory Deficits in Osteoarthritis of the Hip

    PubMed Central

    SHAKOOR, NAJIA; LEE, KRISTEN J.; FOGG, LOUIS F.; BLOCK, JOEL A.

    2013-01-01

    Objective Lower extremity sensory deficits, including reduced proprioception, joint kinesthesia, and, recently, vibratory sense, have been described in subjects with osteoarthritis (OA) of the knee. However, comparable deficits in OA of the hip have not previously been evaluated. Vibratory perception threshold (VPT) is a reliable measure used to assess sensory deficits and is amenable to testing multiple body sites. This study examined VPT at the upper and lower extremities of subjects with hip OA compared with subjects without hip OA. Methods Fourteen subjects with symptomatic and radiographic hip OA were compared with 13 age-matched controls without hip OA. VPT was assessed using a biothesiometer. Five sites in the lower extremity and 1 site in the upper extremity (radial head) were evaluated and compared between OA and control subjects. Results VPT was significantly reduced at all 6 testing sites of the OA subjects compared with controls (P < 0.05 for all sites). VPT scores (mean ± SEM volts) for OA subjects and controls were as follows: first metatarsophalangeal joint (13.5 ± 1.4 versus 7.4 ± 0.7), medial malleolus (18.1 ± 2.6 versus 11.2 ± 1.7), lateral malleolus (20.9 ± 2.4 versus 10.6 ± 1.5), medial femoral condyle (22.8 ± 2.9 versus 12.6 ± 1.3), lateral femoral condyle (26.7 ± 2.6 versus 16.2 ± 1.9), and radial head (10.2 ± 0.8 versus 7.5 ± 0.6). Conclusion To our knowledge, this is the first study to evaluate sensory deficits in hip OA and to demonstrate that there is vibratory sense loss at both the upper and lower extremities in these subjects compared with controls. The noted generalized deficits may have significant implications in the neuromechanical pathophysiology of OA. PMID:18759259

  20. Chaotic behavior on in-phase vibratory conveyors

    SciTech Connect

    Raski, J.Z.

    1998-07-01

    One of the basic building blocks of IBM's computer technology is the thin-film interstitial metallized ceramic (IMC) substrate. The packaging of these substrates employs small input/output (IO) pins to provide both mechanical and electrical connection to the printed circuit board. In the automated manufacturing of the substrate, the input and output pins are individually conveyed by in-line vibratory conveyors. However, a nonperiodic motion of these pins is observed at certain angles of conveyor table tilt that cannot be explained by classical models of friction. This paper models the motion of a single I/O pin on an in-phase, linearly oscillating conveyor using the classical model of friction and compares that result with experimental observations. It is shown here, analytically and experimentally, that when the vibratory conveyor table amplitude and the coefficient of friction between the pin and the table are sufficiently large, the pin is conveyed forward with some velocity. If the conveyor table's angle of tilt is sufficiently large and the coefficient of friction is sufficiently low, the pin may slip backwards just as fast as the conveyor table drives it forward, resulting in a net pin velocity of zero. Surrounding the condition at which the net velocity of the pin is zero is a chaotic basin of attraction in which the pin motion is non-periodic. This basin of attraction was experimentally determined to be bracketed within a range of values of the coefficient of friction. The implications of these theoretical and experimental results are discussed in terms of the practical application of in-phase vibratory conveyors in manufacturing.

  1. Classification of vibratory patterns of the upper airway during sleep.

    PubMed

    Alshaer, Hisham; Rudzicz, Frank; Falk, Tiago H; Tseng, Wen-Hou; Bradley, T Douglas

    2013-01-01

    Upper airway (UA) narrowing and collapse during sleep results in obstructive sleep apnea (OSA). We hypothesize that vibratory patterns of snoring can distinguish simple snorers from those with OSA. Samples of breath sounds were collected from 7 snorers without OSA and 5 with OSA. Snoring pitch (F0) contours were found using the robust algorithm for pitch tracking (RAPT). The OSA snoring contours showed fluctuating patterns as compared to the smoother patterns of simple snorers. This suggests that snoring reveals the underlying instabilities of UA tissue in OSA. Conditional random fields, a statistical sequence classifier, gave 75% accuracy in distinguishing the 2 groups. PMID:24110129

  2. Modification of piezoelectric vibratory gyroscope resonator parameters by feedback control.

    PubMed

    Loveday, P W; Rogers, C A

    1998-01-01

    A method for analyzing the effect of feedback control on the dynamics of piezoelectric resonators used in vibratory gyroscopes has been developed. This method can be used to determine the feasibility of replacing the traditional mechanical balancing operations, used to adjust the resonant frequency, by displacement feedback and for determining the velocity feedback required to produce a particular bandwidth. Experiments were performed on a cylindrical resonator with discrete piezoelectric actuation and sensing elements to demonstrate the principles. Good agreement between analysis and experiment was obtained, and it was shown that this type of resonator could be balanced by displacement feedback. The analysis method presented also is applicable to micromachined piezoelectric gyroscopes. PMID:18244281

  3. Drought and arthropod pests of crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water deficit can make otherwise arable regions less, or nonarable, from lack of life-sustaining water and it can also affect the extent to which crops are afflicted by arthropod pests. The effects of drought on host plant availability and nutrititive value influence arthropod pests of crops in a v...

  4. Herbicide drift affects plant and arthropod communities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field edges, old fields, and other semi-natural habitats in agricultural landscapes support diverse plant communities that help sustain pollinators, predators, and other beneficial arthropods. These plant and arthropod communities may be at persistent ecotoxicological risk from herbicides applied to...

  5. Molecular bases of plant resistance to arthropods.

    PubMed

    Smith, C Michael; Clement, Stephen L

    2012-01-01

    Arthropod-resistant crops provide significant ecological and economic benefits to global agriculture. Incompatible interactions involving resistant plants and avirulent pest arthropods are mediated by constitutively produced and arthropod-induced plant proteins and defense allelochemicals synthesized by resistance gene products. Cloning and molecular mapping have identified the Mi-1.2 and Vat arthropod resistance genes as CC-NBS-LRR (coiled coil-nucleotide binding site-leucine rich repeat) subfamily NBS-LRR resistance proteins, as well as several resistance gene analogs. Genetic linkage mapping has identified more than 100 plant resistance gene loci and linked molecular markers used in cultivar development. Rice and sorghum arthropod-resistant cultivars and, to a lesser extent, raspberry and wheat cultivars are components of integrated pest management (IPM) programs in Asia, Australia, Europe, and North America. Nevertheless, arthropod resistance in most food and fiber crops has not been integrated due primarily to the application of synthetic insecticides. Plant and arthropod genomics provide many opportunities to more efficiently develop arthropod-resistant plants, but integration of resistant cultivars into IPM programs will succeed only through interdisciplinary collaboration. PMID:21910639

  6. Noninsect Arthropods in Popular Music

    PubMed Central

    Coelho, Joseph R.

    2011-01-01

    The occurrence of noninsect arthropods in popular music was examined in order to explore human attitudes toward these species, especially as compared to insects. Crustaceans were the most commonly referenced taxonomic group in artist names, album titles and cover art, followed by spiders and scorpions. The surprising prevalence of crustaceans may be related to the palatability of many of the species. Spiders and scorpions were primarily used for shock value, as well as totemic qualities of strength and ferocity. Spiders were the most abundant group among song titles, perhaps because of their familiarity to the general public. Three noninsect arthropod album titles were found from the early 1970s, then none appear until 1990. Older albums are difficult to find unless they are quite popular, and the resurgence of albums coincides with the rise of the internet. After 1990, issuance of such albums increased approximately linearly. Giant and chimeric album covers were the most common of themes, indicating the use of these animals to inspire fear and surprise. The lyrics of select songs are presented to illustrate the diversity of sentiments present, from camp spookiness to edibility. PMID:26467627

  7. Arthropods affecting the human eye.

    PubMed

    Panadero-Fontán, Rosario; Otranto, Domenico

    2015-02-28

    Ocular infestations by arthropods consist in the parasitization of the human eye, either directly (e.g., some insect larvae causing ophthalmomyiasis) or via arthropods feeding on lachrymal/conjunctival secretions (e.g., some eye-seeking insects, which also act as vectors of eye pathogens). In addition, demodicosis and phthiriasis may also cause eye discomfort in humans. Ophthalmomyiasis by larvae of the families Oestridae, Calliphoridae and Sarcophagidae, are frequent causative agents of human ocular infestations. Over the last decades, the extensive use of macrocyclic lactones in cattle has reduced the frequency of infestations by Hypoderma bovis and Hypoderma lineatum (family Oestridae), and consequently, human infestations by these species. A prompt diagnosis of ocular myiasis (e.g., by serological tests) is pivotal for positive prognoses, particularly when the larvae are not detectable during the ophthalmologic examination. Molecular diagnoses may also assist physicians and parasitologists in achieving time-efficient diagnoses of infestations by Oestridae causing myiasis. Finally, due to widespread international travel to exotic destinations, cases of myiasis are increasing in non-endemic areas, therefore requiring physicians to acquire a profound knowledge of the clinical symptoms linked to these infestations to prevent costly, inappropriate treatments or severe complications. PMID:25620292

  8. [Arthropods with vectorial interest in spanish public health].

    PubMed

    Bueno Marí, Rubén; Moreno Marí, Josefa; Oltra Moscardó, M Teresa; Jiménez Peydró, Ricardo

    2009-01-01

    Fifteen of the thirty-one Obligatory Communicable Diseases in Spain, exempting those of congenital or neonatal types, can be transmitted by several species of arthropods that are present in our country. Several arthropod orders are the suitable transmitters of tens of bacteria, fungi, virus and protozoa. This fact demands a through of the biology knowledge of these vectors in order to adopt efficient control measures that allow us to reduce the incidence levels of these diseases. Nevertheless, the epidemiological studies shouldn't remain only restricted to the diseases with active transmission cycles in our country. It is necessary to acquire a global vision because of allochton diseases that are perfectly extensible to our territory in the globalization context in which we are situated. All this information is important to know which factors are preventing the disease presence. The aim is to provide the National Epidemiological Surveillance Network with a valuable predictive capacity that allows it to predict the potential arrival of diseases and the consequent strengthening of the spanish Public Health. The goal of this work is to carry out a review of the spanish arthropod fauna with any vectorial interest. The current situation of some of the more important vectorial diseases in our country and the factors related to a resurgence reappearance and/or intensification of those ones are also discussed. Therefore, the study of these inappealable protagonists in our Public Health as an articulatory element in the complex network that any vectorial disease entails is absolutely necessary. PMID:19626248

  9. A subharmonic vibratory pattern in normal vocal folds.

    PubMed

    Svec, J G; Schutte, H K; Miller, D G

    1996-02-01

    This study observes in detail an F0/2 (sounding an octave below an original tone) subharmonic vibratory pattern produced in a normal larynx. Simultaneous electroglottographic and photoglottographic measurements reveal two different open phases within a subharmonic cycle- the first shorter with a simple shape, the second longer with a shape containing a "ripple." Such parameters as the large open quotient (ca. 0.8) and the high airflow values (ca. 1000 cm3/s) distinguish this phonation from the vocal fry (pulse) register. Using an electronic divider to track the subharmonic frequency, a method has been developed to observe the subharmonic vibration of the vocal folds stroboscopically. The stroboscopic visualization reveals an unusual mucosal movement during the "ripple," characterized by an opening movement of the upper margins, which interrupts the closing movement of the vocal folds. An explanation is offered that this vibratory pattern arises as a consequence of detuning of the usually identical frequencies of the dominant modes of the vocal folds, with 3:2 entrainment replacing the normal 1:1 pattern. PMID:8820705

  10. Vibratory compaction method for preparing lunar regolith drilling simulant

    NASA Astrophysics Data System (ADS)

    Chen, Chongbin; Quan, Qiquan; Deng, Zongquan; Jiang, Shengyuan

    2016-07-01

    Drilling and coring is an effective way to acquire lunar regolith samples along the depth direction. To facilitate the modeling and simulation of lunar drilling, ground verification experiments for drilling and coring should be performed using lunar regolith simulant. The simulant should mimic actual lunar regolith, and the distribution of its mechanical properties should vary along the longitudinal direction. Furthermore, an appropriate preparation method is required to ensure that the simulant has consistent mechanical properties so that the experimental results can be repeatable. Vibratory compaction actively changes the relative density of a raw material, making it suitable for building a multilayered drilling simulant. It is necessary to determine the relation between the preparation parameters and the expected mechanical properties of the drilling simulant. A vibratory compaction model based on the ideal elastoplastic theory is built to represent the dynamical properties of the simulant during compaction. Preparation experiments indicated that the preparation method can be used to obtain drilling simulant with the desired mechanical property distribution along the depth direction.

  11. The underwater sound field from vibratory pile driving.

    PubMed

    Dahl, Peter H; Dall'Osto, David R; Farrell, Dara M

    2015-06-01

    Underwater noise from vibratory pile driving was observed using a vertical line array placed at range 16 m from the pile source (water depth 7.5 m), and using single hydrophones at range 417 m on one transect, and range 207 and 436 m on another transect running approximately parallel to a sloping shoreline. The dominant spectral features of the underwater noise are related to the frequency of the vibratory pile driving hammer (typically 15-35 Hz), producing spectral lines at intervals of this frequency. The mean-square pressure versus depth is subsequently studied in third-octave bands. Depth and frequency variations of this quantity observed at the vertical line array are well modeled by a field consisting of an incoherent sum of sources distributed over the water column. Adiabatic mode theory is used to propagate this field to greater ranges and model the observations made along the two depth-varying transects. The effect of shear in the seabed, although small, is also included. Bathymetric refraction on the transect parallel to the shoreline reduced mean-square pressure levels at the 436-m measurement site. PMID:26093441

  12. Vibratory strain field measurement by transverse digital holography.

    PubMed

    Stetson, Karl A

    2015-09-20

    A method is presented for measuring vibratory strain fields using phase-stepped, image-plane digital holography. An object surface is observed along its normal vector while illuminated at equal and opposite angles by two mutually coherent laser beams. One beam is phase stepped by quarter-wavelength increments between TV frames, and the resulting images are processed to yield holographic images. Object vibrations result in zero-order Bessel function fringes in the display. The second beam is modulated at the same frequency of the object vibration and is used to shift the fringes in a manner analogous to phase step interferometry. The resulting images are processed to yield a wrapped phase map, which is unwrapped and corrected for the error associated with using zero-order Bessel functions in place of cosine functions. The unwrapped images are processed to obtain the average slopes for image segments, and these slopes are multiplied by a scale factor to convert them to strain. The analysis program used here divides the field of view into five horizontal by four vertical segments, which provide a map of the vibratory strain field. PMID:26406526

  13. Traumatic insemination in terrestrial arthropods.

    PubMed

    Tatarnic, Nikolai J; Cassis, Gerasimos; Siva-Jothy, Michael T

    2014-01-01

    Traumatic insemination is a bizarre form of mating practiced by some invertebrates in which males use hypodermic genitalia to penetrate their partner's body wall during copulation, frequently bypassing the female genital tract and ejaculating into their blood system. The requirements for traumatic insemination to evolve are stringent, yet surprisingly it has arisen multiple times within invertebrates. In terrestrial arthropods traumatic insemination is most prevalent in the true bug infraorder Cimicomorpha, where it has evolved independently at least three times. Traumatic insemination is thought to occur in the Strepsiptera and has recently been recorded in fruit fly and spider lineages. We review the putative selective pressures that may have led to the evolution of traumatic insemination across these lineages, as well as the pressures that continue to drive divergence in male and female reproductive morphology and behavior. Traumatic insemination mechanisms and attributes are compared across independent lineages. PMID:24160423

  14. Effects of invasive plants on arthropods.

    PubMed

    Litt, Andrea R; Cord, Erin E; Fulbright, Timothy E; Schuster, Greta L

    2014-12-01

    Non-native plants have invaded nearly all ecosystems and represent a major component of global ecological change. Plant invasions frequently change the composition and structure of vegetation communities, which can alter animal communities and ecosystem processes. We reviewed 87 articles published in the peer-reviewed literature to evaluate responses of arthropod communities and functional groups to non-native invasive plants. Total abundance of arthropods decreased in 62% of studies and increased in 15%. Taxonomic richness decreased in 48% of studies and increased in 13%. Herbivorous arthropods decreased in response to plant invasions in 48% of studies and increased in 17%, likely due to direct effects of decreased plant diversity. Predaceous arthropods decreased in response to invasive plants in 44% of studies, which may reflect indirect effects due to reductions in prey. Twenty-two percent of studies documented increases in predators, which may reflect changes in vegetation structure that improved mobility, survival, or web-building for these species. Detritivores increased in 67% of studies, likely in response to increased litter and decaying vegetation; no studies documented decreased abundance in this functional group. Although many researchers have examined effects of plant invasions on arthropods, sizeable information gaps remain, specifically regarding how invasive plants influence habitat and dietary requirements. Beyond this, the ability to predict changes in arthropod populations and communities associated with plant invasions could be improved by adopting a more functional and mechanistic approach. Understanding responses of arthropods to invasive plants will critically inform conservation of virtually all biodiversity and ecological processes because so many organisms depend on arthropods as prey or for their functional roles, including pollination, seed dispersal, and decomposition. Given their short generation times and ability to respond rapidly to

  15. Communication.

    ERIC Educational Resources Information Center

    Strauss, Andre

    The following essays on communication are presented: communication as a condition of survival, communication for special purposes, the means of transmission of communication, communication within social and economic structures, the teaching of communication through the press, the teaching of modern languages, communication as a point of departure,…

  16. Emerging tools for identification of arthropod vectors.

    PubMed

    Yssouf, Amina; Almeras, Lionel; Raoult, Didier; Parola, Philippe

    2016-04-01

    The rapid and reliable identification of arthropod vector species is an essential component of the fight against vector-borne diseases. However, owing to the lack of entomological expertise required for the morphological identification method, development of alternative and complementary tools is needed. This review describes the main methods used for arthropod identification, focusing on the emergence of protein profiling using MALDI-TOF MS technology. Sample preparation, analysis of reproducibility, database creation and blind tests for controlling accuracy of this tool for arthropod identification are described. The advantages and limitations of the MALDI-TOF MS method are illustrated by emphasizing different hematophagous arthropods, including mosquitoes and ticks, the top two main vectors of infectious diseases. PMID:27070074

  17. Parametric identification of a vibratory system with a clearance

    NASA Technical Reports Server (NTRS)

    Alexander, R. M.; Noah, S. T.; Franck, C. G.

    1993-01-01

    An analytical and experimental investigation of a vibratory system with a clearance was conducted. A finite element model and an equivalent single-degree-of-freedom closed-form solution were used to determine the dynamic parameters and response of an experimental structure interacting with a gap. The closed-form solution is obtained by taking advantage of the piecewise linearity of the system. Results from these solution methods are in agreement with experimental data. The results also suggest that the closed-form solution approximates the response of the experimental structure with accuracy greater than that of the finite element model. The closed-form solution was also used to determine the gap size of the structure. The parameter identification procedure utilized in this study appears to be simple to use and can be readily extended to other types of piecewise-linear multi-degree-of-freedom systems.

  18. Regulation of ecosystem processes by arthropod communities

    SciTech Connect

    Seastedt, T.R.; Crossley, D.A. Jr.

    1983-09-01

    Arthropods or their activities regulate the amounts of forms of mass and nutrients in terrestrial ecosystems. Canopy arthropods have the largest impacts on mobile elements such as potassium, while soil detritivores control mineralization rates of less mobile elements such as nitrogen, phosphorus and calcium. Nominal (base-line) herbivory and detritivory combine to speed nutrient cycling and reduce standing crops of decaying plant materials. 42 references, 1 figure, 3 tables.

  19. Cambrian bivalved arthropod reveals origin of arthrodization.

    PubMed

    Legg, David A; Sutton, Mark D; Edgecombe, Gregory D; Caron, Jean-Bernard

    2012-12-01

    Extant arthropods are diverse and ubiquitous, forming a major constituent of most modern ecosystems. Evidence from early Palaeozoic Konservat Lagerstätten indicates that this has been the case since the Cambrian. Despite this, the details of arthropod origins remain obscure, although most hypotheses regard the first arthropods as benthic predators or scavengers such as the fuxianhuiids or megacheirans ('great-appendage' arthropods). Here, we describe a new arthropod from the Tulip Beds locality of the Burgess Shale Formation (Cambrian, series 3, stage 5) that possesses a weakly sclerotized thorax with filamentous appendages, encased in a bivalved carapace, and a strongly sclerotized, elongate abdomen and telson. A cladistic analysis resolved this taxon as the basal-most member of a paraphyletic grade of nekto-benthic forms with bivalved carapaces. This grade occurs at the base of Arthropoda (panarthropods with arthropodized trunk limbs) and suggests that arthrodization (sclerotization and jointing of the exoskeleton) evolved to facilitate swimming. Predatory and fully benthic habits evolved later in the euarthropod stem-lineage and are plesiomorphically retained in pycnogonids (sea spiders) and euchelicerates (horseshoe crabs and arachnids). PMID:23055069

  20. Cambrian bivalved arthropod reveals origin of arthrodization

    PubMed Central

    Legg, David A.; Sutton, Mark D.; Edgecombe, Gregory D.; Caron, Jean-Bernard

    2012-01-01

    Extant arthropods are diverse and ubiquitous, forming a major constituent of most modern ecosystems. Evidence from early Palaeozoic Konservat Lagerstätten indicates that this has been the case since the Cambrian. Despite this, the details of arthropod origins remain obscure, although most hypotheses regard the first arthropods as benthic predators or scavengers such as the fuxianhuiids or megacheirans (‘great-appendage’ arthropods). Here, we describe a new arthropod from the Tulip Beds locality of the Burgess Shale Formation (Cambrian, series 3, stage 5) that possesses a weakly sclerotized thorax with filamentous appendages, encased in a bivalved carapace, and a strongly sclerotized, elongate abdomen and telson. A cladistic analysis resolved this taxon as the basal-most member of a paraphyletic grade of nekto-benthic forms with bivalved carapaces. This grade occurs at the base of Arthropoda (panarthropods with arthropodized trunk limbs) and suggests that arthrodization (sclerotization and jointing of the exoskeleton) evolved to facilitate swimming. Predatory and fully benthic habits evolved later in the euarthropod stem-lineage and are plesiomorphically retained in pycnogonids (sea spiders) and euchelicerates (horseshoe crabs and arachnids). PMID:23055069

  1. [Relation between voice quality and pathological vibratory patterns using high-speed digital imaging].

    PubMed

    Miyaji, M; Iwamoto, Y; Oda, M; Niimi, S

    1999-03-01

    We analysed the vocal fold vibrations of 22 pathological larynges using a computer-assisted high-speed digital imaging technique. The parameters observed included symmetry, regularity, phase difference, glottal closure, amplitude, mucosal wave and periodicity difference. Voice quality was evaluated by a GRBAS system, and we examined the relation between vocal fold vibration patterns and voice quality. The intraexaminer correlation coefficient was high for the G, R and B scales. Vibratory patterns were classified according to the location of the lesion, severity of the disease, expiratory pressure and laryngeal modulation. Although there were no matches between a vocal fold vibratory pattern for one psychoacoustic impression of hoarseness, the characteristic vibratory patterns of these cases of R > or = 2.5 or diplophonia exhibited irregular glottal closure and periodicity differences. The characteristic vibratory pattern of vocal fry is a double or triple opening/closing phase, followed by a long closed phase. PMID:10226472

  2. Amitriptyline and bromazepam in the treatment of vibratory angioedema: which role for neuroinflammation?

    PubMed

    Guarneri, Fabrizio; Guarneri, Claudio; Marini, Herbert Ryan

    2014-01-01

    Vibratory angioedema is a rare form of physical urticaria, hereditary or acquired, which occurs at body sites exposed to vibrations. Pathogenic mechanisms of disease are not completely clear and, consequently, current pharmacological treatment is sometimes unsatisfactory. We report the case of a horn player affected by acquired vibratory angioedema, relapsing after prolonged use of the instrument and resistant to systemic antihistamines and corticosteroids, which successfully responded to therapy with low doses of amitriptyline and bromazepam. A neuroinflammatory mechanism can be likely implicated in the pathogenesis of vibratory angioedema, in line with many different cutaneous/mucosal diseases involving a complex interplay of homeostatic/allostatic systems. Furthermore, in mucosal diseases, such as vibratory angioedema, physical/psychological stressors have a relevant role. In such cases, because of the complex interplay between nervous and immune system, the pharmacological activity of benzodiazepines and typical antidepressants may downregulate neuroinflammation. PMID:25052839

  3. Jean-Martin Charcot and his vibratory chair for Parkinson disease.

    PubMed

    Goetz, Christopher G

    2009-08-11

    Vibration therapy is currently used in diverse medical specialties ranging from orthopedics to urology to sports medicine. The celebrated 19th-century neurologist, J.-M. Charcot, used vibratory therapy to treat Parkinson disease (PD). This study analyzed printed writings by Charcot and other writers on vibratory therapy and accessed unpublished notes from the Salpêtrière Hospital, Paris. Charcot lectured on several occasions on vibratory therapy and its neurologic applications. He developed a vibration chair for patients with PD after he observed that patients were more comfortable and slept better after a train or carriage ride. He replicated this experience by having patients undergo daily 30-minute sessions in the automated vibratory chair (fauteuil trépidant). His junior colleague, Gilles de la Tourette, extended these observations and developed a helmet that vibrated the head on the premise that the brain responded directly to the pulsations. Although after Charcot's death vibratory therapy was not widely pursued, vibratory appliances are reemerging in 21st century medicine and can be retested using adaptations of Charcot's neurologic protocols. PMID:19667323

  4. Arthropods of medicoveterinary importance in zoos.

    PubMed

    Adler, Peter H; Tuten, Holly C; Nelder, Mark P

    2011-01-01

    Zoos present a unique assemblage of arthropods, captive vertebrates, free-roaming wildlife, humans, and plants, each with its own biota of symbiotic organisms. Arthropods of medicoveterinary importance are well represented in zoos, and an ample literature documents their influence in these animal-rich environments. Mosquitoes are of greatest significance because of the animal and human pathogens they transmit, followed by ectoparasites, many of which are exotic and present health risks to captive and native animals. Biting flies, cockroaches, filth flies, and triatomid bugs represent additional concerns. Integrated management programs for arthropods in zoos are commonplace. Zoos can play a role in biosurveillance, serving as an advanced guard for detecting exotic arthropods and vector-borne diseases. We provide the first review of arthropods of medicoveterinary importance in zoos. A case is made for the value of collaborations between entomologists and zoo personnel as a means of enhancing research and public education while safeguarding the health of captive animals and the public. PMID:20731604

  5. Reevaluating the arthropod tree of life.

    PubMed

    Giribet, Gonzalo; Edgecombe, Gregory D

    2012-01-01

    Arthropods are the most diverse group of animals and have been so since the Cambrian radiation. They belong to the protostome clade Ecdysozoa, with Onychophora (velvet worms) as their most likely sister group and tardigrades (water bears) the next closest relative. The arthropod tree of life can be interpreted as a five-taxon network, containing Pycnogonida, Euchelicerata, Myriapoda, Crustacea, and Hexapoda, the last two forming the clade Tetraconata or Pancrustacea. The unrooted relationship of Tetraconata to the three other lineages is well established, but of three possible rooting positions the Mandibulata hypothesis receives the most support. Novel approaches to studying anatomy with noninvasive three-dimensional reconstruction techniques, the application of these techniques to new and old fossils, and the so-called next-generation sequencing techniques are at the forefront of understanding arthropod relationships. Cambrian fossils assigned to the arthropod stem group inform on the origin of arthropod characters from a lobopodian ancestry. Monophyly of Pycnogonida, Euchelicerata, Myriapoda, Tetraconata, and Hexapoda is well supported, but the interrelationships of arachnid orders and the details of crustacean paraphyly with respect to Hexapoda remain the major unsolved phylogenetic problems. PMID:21910637

  6. Epidemiology of the arthropod-borne encephalitides*

    PubMed Central

    Miles, J. A. R.

    1960-01-01

    Since the recognition that louping-ill, known for well over 100 years as an epizootic disease of sheep in Scotland, was caused by a virus transmitted by arthropods, many other arthropod-borne viruses capable of causing encephalitis in domestic animals or man have been discovered. The author reviews here the knowledge at present available on these viruses, originally termed ”arthropod-borne encephalitides viruses” but now often referred to as ”arbor viruses”. In this discussion of the host and vector relationships of the two broad groups of arbor viruses — the mosquito-borne and the tick-borne—and of the distribution, epidemiology and control of the various diseases they cause, the author includes an outline of the types of investigation likely to provide the most useful information, stressing in this connexion the value of ecological surveys. PMID:14422369

  7. Sophisticated digestive systems in early arthropods.

    PubMed

    Vannier, Jean; Liu, Jianni; Lerosey-Aubril, Rudy; Vinther, Jakob; Daley, Allison C

    2014-01-01

    Understanding the way in which animals diversified and radiated during their early evolutionary history remains one of the most captivating of scientific challenges. Integral to this is the 'Cambrian explosion', which records the rapid emergence of most animal phyla, and for which the triggering and accelerating factors, whether environmental or biological, are still unclear. Here we describe exceptionally well-preserved complex digestive organs in early arthropods from the early Cambrian of China and Greenland with functional similarities to certain modern crustaceans and trace these structures through the early evolutionary lineage of fossil arthropods. These digestive structures are assumed to have allowed for more efficient digestion and metabolism, promoting carnivory and macrophagy in early arthropods via predation or scavenging. This key innovation may have been of critical importance in the radiation and ecological success of Arthropoda, which has been the most diverse and abundant invertebrate phylum since the Cambrian. PMID:24785191

  8. Responses of prairie arthropod communities to fire and fertilizer: Balancing plant and arthropod conservation

    USGS Publications Warehouse

    Hartley, M.K.; Rogers, W.E.; Siemann, E.; Grace, J.

    2007-01-01

    Fire is an important tool for limiting woody plant invasions into prairies, but using fire management to maintain grassland plant communities may inadvertently reduce arthropod diversity. To test this, we established twenty-four 100 m2 plots in a tallgrass prairie in Galveston County, Texas, in spring 2000. Plots were assigned a fire (no burn, one time burn [2000], two time burn [2000, 2001]) and fertilization treatment (none, NPK addition) in a full factorial design. Fertilization treatments allowed us to examine the effects of fire at a different level of productivity. We measured plant cover by species and sampled arthropods with sweep nets during the 2001 growing season. Path analysis indicated that fertilization reduced while annual fires increased arthropod diversity via increases and decreases in woody plant abundance, respectively. There was no direct effect of fire on arthropod diversity or abundance. Diptera and Homoptera exhibited particularly strong positive responses to fires. Lepidoptera had a negative response to nutrient enrichment. Overall, the negative effects of fire on the arthropod community were minor in contrast to the strong positive indirect effects of small-scale burning on arthropod diversity if conservation of particular taxa is not a priority. The same fire regime that minimized woody plant invasion also maximized arthropod diversity.

  9. Error Model and Compensation of Bell-Shaped Vibratory Gyro

    PubMed Central

    Su, Zhong; Liu, Ning; Li, Qing

    2015-01-01

    A bell-shaped vibratory angular velocity gyro (BVG), inspired by the Chinese traditional bell, is a type of axisymmetric shell resonator gyroscope. This paper focuses on development of an error model and compensation of the BVG. A dynamic equation is firstly established, based on a study of the BVG working mechanism. This equation is then used to evaluate the relationship between the angular rate output signal and bell-shaped resonator character, analyze the influence of the main error sources and set up an error model for the BVG. The error sources are classified from the error propagation characteristics, and the compensation method is presented based on the error model. Finally, using the error model and compensation method, the BVG is calibrated experimentally including rough compensation, temperature and bias compensation, scale factor compensation and noise filter. The experimentally obtained bias instability is from 20.5°/h to 4.7°/h, the random walk is from 2.8°/h1/2 to 0.7°/h1/2 and the nonlinearity is from 0.2% to 0.03%. Based on the error compensation, it is shown that there is a good linear relationship between the sensing signal and the angular velocity, suggesting that the BVG is a good candidate for the field of low and medium rotational speed measurement. PMID:26393593

  10. Relationships between CSID and vocal fold vibratory function

    NASA Astrophysics Data System (ADS)

    Cooke, Melissa L.

    High correlations have been reported between the acoustic-based Cepstral/Spectral Index of Dysphonia (CSID) and perceptual judgments of dysphonia. This study explores whether CSID provides additional insight and explains more of the variance in HSV-based properties of vocal fold vibratory function than has been reported for other acoustic measures. Using the Analysis of Dysphonia in Speech and Voice (ADSV) program, CSID and its component variables were correlated with HSV-based measures of glottal cycle aperiodicity and glottal area for 20 subjects who underwent phonomicrosurgery. Results indicate CSID is only marginally correlated with glottal cycle aperiodicity in pre- and post-surgical conditions and does not correlate as highly as the cepstral peak prominence alone. Additionally, results reveal higher correlations when examining within-subject change from pre-surgical to post-surgical assessments rather than correlating measures across subjects. Future directions are discussed that aim at improving our understanding of the relationships between acoustic parameters and underlying phonatory function.

  11. Error Model and Compensation of Bell-Shaped Vibratory Gyro.

    PubMed

    Su, Zhong; Liu, Ning; Li, Qing

    2015-01-01

    A bell-shaped vibratory angular velocity gyro (BVG), inspired by the Chinese traditional bell, is a type of axisymmetric shell resonator gyroscope. This paper focuses on development of an error model and compensation of the BVG. A dynamic equation is firstly established, based on a study of the BVG working mechanism. This equation is then used to evaluate the relationship between the angular rate output signal and bell-shaped resonator character, analyze the influence of the main error sources and set up an error model for the BVG. The error sources are classified from the error propagation characteristics, and the compensation method is presented based on the error model. Finally, using the error model and compensation method, the BVG is calibrated experimentally including rough compensation, temperature and bias compensation, scale factor compensation and noise filter. The experimentally obtained bias instability is from 20.5°/h to 4.7°/h, the random walk is from 2.8°/h(1/2) to 0.7°/h(1/2) and the nonlinearity is from 0.2% to 0.03%. Based on the error compensation, it is shown that there is a good linear relationship between the sensing signal and the angular velocity, suggesting that the BVG is a good candidate for the field of low and medium rotational speed measurement. PMID:26393593

  12. Collective behavior in an early Cambrian arthropod.

    PubMed

    Hou, Xian-Guang; Siveter, Derek J; Aldridge, Richard J; Siveter, David J

    2008-10-10

    Examples that indicate collective behavior in the fossil record are rare. A group association of specimens that belong to a previously unknown arthropod from the Chengjiang Lagerstätte, China, provides evidence that such behavior was present in the early Cambrian (about 525 million years ago), coincident with the earliest extensive diversification of the Metazoa, the so-called Cambrian explosion event. The chainlike form of these specimens is unique for any arthropod, fossil or living, and most likely represents behavior associated with migration. PMID:18845748

  13. Arthropods vector grapevine trunk disease pathogens.

    PubMed

    Moyo, P; Allsopp, E; Roets, F; Mostert, L; Halleen, F

    2014-10-01

    Arthropod-mediated dispersal of pathogens is known in many cropping systems but has never been demonstrated for grapevine trunk disease pathogens. Arthropods from vineyards were screened for the presence of pathogens associated with Petri disease and esca using cultural and molecular techniques. The ability of the most abundant pathogen-carrying species to inoculate healthy grapevine vascular tissues was also determined. Millipedes and ants were allowed to associate with a DsRed- Express-transformed Phaeomoniella chlamydospora, after which they were exposed to freshly pruned healthy grapevines under controlled conditions and wounds were monitored for subsequent infection. In addition, the possibility of millipede excreta, commonly found on pruning wounds in the field, to act as inoculum source was determined. A diverse arthropod fauna was associated with declining grapevines and many of these carried trunk disease pathogens. However, spiders, the ant Crematogaster peringueyi, and the millipede Ommattoiulus moreleti were the most abundant pathogen carriers. The ant and millipede species fed on pruning wound sap and effectively transmitted trunk disease pathogens. Millipede excreta contained viable spores of Phaeomoniella chlamydospora and may serve as an inoculum source. Numerous arthropods, including beneficial predators, are potential vectors of grapevine trunk disease pathogens. Our results highlight the need for an integrated approach, including targeted management of ants and millipedes at the time of pruning, to limit the spread of grapevine trunk diseases. PMID:24624953

  14. Resistance mechanisms against arthropod herbivores in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton plants from the genus Gossypium are grown on more than 30 million hectares worldwide and are a major source of fiber. The plants possess a wide-range of indirect and direct-defense mechanisms against arthropod pests. Direct defense mechanisms include morphological traits such as trichomes and...

  15. RNAi in agriculturally-important arthropods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our aim in this chapter is to provide an overview of the profound knowledge accumulated in recent years from invertebrate RNAi studies, but with a focus on agriculturally important arthropods. We start with a brief discussion of the RNAi mechanism to introduce readers to key concepts that underlie t...

  16. Communications

    NASA Technical Reports Server (NTRS)

    Stouffer, Donald D.

    1990-01-01

    Communication in its many forms is a critical component for an effective Space Grant Program. Good communication is needed within individual Space Grant College/Consortia, for example between consortium affiliates and the consortium program office. Effective communication between the several programs, NASA Headquarters, and NASA field centers also is required. Further, communication among the above program elements, industry, local and state government, and the public also are necessary for meeting program objectives.

  17. Trees as templates for tropical litter arthropod diversity.

    PubMed

    Donoso, David A; Johnston, Mary K; Kaspari, Michael

    2010-09-01

    Increased tree species diversity in the tropics is associated with even greater herbivore diversity, but few tests of tree effects on litter arthropod diversity exist. We studied whether tree species influence patchiness in diversity and abundance of three common soil arthropod taxa (ants, gamasid mites, and oribatid mites) in a Panama forest. The tree specialization hypothesis proposes that tree-driven habitat heterogeneity maintains litter arthropod diversity. We tested whether tree species differed in resource quality and quantity of their leaf litter and whether more heterogeneous litter supports more arthropod species. Alternatively, the abundance-extinction hypothesis states that arthropod diversity increases with arthropod abundance, which in turn tracks resource quantity (e.g., litter depth). We found little support for the hypothesis that tropical trees are templates for litter arthropod diversity. Ten tree species differed in litter depth, chemistry, and structural variability. However, the extent of specialization of invertebrates on particular tree taxa was low and the more heterogeneous litter between trees failed to support higher arthropod diversity. Furthermore, arthropod diversity did not track abundance or litter depth. The lack of association between tree species and litter arthropods suggests that factors other than tree species diversity may better explain the high arthropod diversity in tropical forests. PMID:20349247

  18. The monitoring system for vibratory disturbance detection in microgravity environment aboard the international space station

    NASA Technical Reports Server (NTRS)

    Laster, Rachel M.

    2004-01-01

    Scientists in the Office of Life and Microgravity Sciences and Applications within the Microgravity Research Division oversee studies in important physical, chemical, and biological processes in microgravity environment. Research is conducted in microgravity environment because of the beneficial results that come about for experiments. When research is done in normal gravity, scientists are limited to results that are affected by the gravity of Earth. Microgravity provides an environment where solid, liquid, and gas can be observed in a natural state of free fall and where many different variables are eliminated. One challenge that NASA faces is that space flight opportunities need to be used effectively and efficiently in order to ensure that some of the most scientifically promising research is conducted. Different vibratory sources are continually active aboard the International Space Station (ISS). Some of the vibratory sources include crew exercise, experiment setup, machinery startup (life support fans, pumps, freezer/compressor, centrifuge), thruster firings, and some unknown events. The Space Acceleration Measurement System (SAMs), which acts as the hardware and carefully positioned aboard the ISS, along with the Microgravity Environment Monitoring System MEMS), which acts as the software and is located here at NASA Glenn, are used to detect these vibratory sources aboard the ISS and recognize them as disturbances. The various vibratory disturbances can sometimes be harmful to the scientists different research projects. Some vibratory disturbances are recognized by the MEMS's database and some are not. Mainly, the unknown events that occur aboard the International Space Station are the ones of major concern. To better aid in the research experiments, the unknown events are identified and verified as unknown events. Features, such as frequency, acceleration level, time and date of recognition of the new patterns are stored in an Excel database. My task is to

  19. External stimuli in the form of vibratory massage after heart or lung transplantation.

    PubMed

    Doering, T J; Fieguth, H G; Steuernagel, B; Brix, J; Konitzer, M; Schneider, B; Fischer, G C

    1999-01-01

    Manual vibratory massage is part of the preventive physiotherapeutic activities performed in intensive care units. The vibratory massage can be performed manually or as electrovibratory massage. The manual massage is a fast rhythmical vibration performed by the arm and shoulder muscles of the masseur and transferred to the patient's thorax by the hand. The hand of the masseur has to achieve a tremor with a frequency of 8 to 11 tremors/s. The aim of the pilot study was to examine the influence of manual vibratory massage on the pulmonary function of postoperative patients who were receiving mechanical ventilation, with special interest being focused on pulmonary ventilation and perfusion and cerebral blood flow velocity. Manual vibratory massage was performed postoperatively in the intensive care unit on eight patients: three patients had undergone heart transplantation, three had undergone lung transplantation, and two had undergone coronary artery bypass grafting (mean age, 53.6+/-8 yr). With the aid of continuous monitoring, we examined the changes of the respiration parameters and the cerebral blood flow velocity (measured by transcranial Doppler sonography). The vibratory massage was performed with a frequency of 8 to 10 vibrations/s for 15 min, 7.5 min on each side of the thorax, starting from the lower costal arch and progressing to the upper thoracic aperture. For 10 min before, during, and 10 min after the massage, the parameters of peripheral oxygen saturation, central venous pressure, mean arterial pressure, heart rate, lung resistance and compliance, tidal volume, respiration rate, and cerebral blood flow velocity were recorded at 2-min intervals. Moreover, before and after vibratory massage, arterial blood gases were determined. In four of the eight patients, it was possible to determine pulmonary arterial pressure, pulmonary capillary wedge pressure, as well as pulmonary vascular resistance. During the vibratory massage, we could prove a significant

  20. Effect of angular inflow on the vibratory response of a counter-rotating propeller

    NASA Technical Reports Server (NTRS)

    Turnberg, J. E.; Brown, P. C.

    1985-01-01

    This report presents the results of a propeller vibratory stress survey on the Fairey Gannet aircraft aimed at giving an assessment of the difference in vibratory response between single and counter-rotating propeller operation in angular inflow. The survey showed that counter-rotating operation of the propeller had the effect of increasing the IP response of the rear propeller by approximately 25 percent over comparable single-rotation operation while counter-rotating operation did not significantly influence the IP response of the front propeller.

  1. Arthropod larvae misidentified as parasitic worm infection.

    PubMed

    Munisamy, Sreetharan; Kilner, Rachael

    2011-01-01

    A healthy, asymptomatic man living in London, presented with seeing 'worms' in his toilet for two successive summer seasons. Repeated microscopic examination and cultures of both his faeces and urine were normal. He was empirically treated with multiple courses of antihelminthics without resolution of this problem. A sample of the worms was obtained, and positively identified as arthropod larvae under microscopic examination. These larvae do not parasitically colonise humans. It was subsequently deduced that a flying arthropod (most likely Culex pipiens mosquito) had laid eggs in standing toilet water, and the hatched larvae had been mistaken for parasitic worms. The patient was declared free of parasites and remains healthy. This case illustrates the dangers of starting empirical treatment without positive confirmation of causative organisms, which can result in unnecessary and potentially harmful treatment. PMID:22675109

  2. Arthropods in amber from the Triassic Period

    PubMed Central

    Schmidt, Alexander R.; Jancke, Saskia; Lindquist, Evert E.; Ragazzi, Eugenio; Roghi, Guido; Nascimbene, Paul C.; Schmidt, Kerstin; Wappler, Torsten; Grimaldi, David A.

    2012-01-01

    The occurrence of arthropods in amber exclusively from the Cretaceous and Cenozoic is widely regarded to be a result of the production and preservation of large amounts of tree resin beginning ca. 130 million years (Ma) ago. Abundant 230 million-year-old amber from the Late Triassic (Carnian) of northeastern Italy has previously yielded myriad microorganisms, but we report here that it also preserves arthropods some 100 Ma older than the earliest prior records in amber. The Triassic specimens are a nematoceran fly (Diptera) and two disparate species of mites, Triasacarus fedelei gen. et sp. nov., and Ampezzoa triassica gen. et sp. nov. These mites are the oldest definitive fossils of a group, the Eriophyoidea, which includes the gall mites and comprises at least 3,500 Recent species, 97% of which feed on angiosperms and represents one of the most specialized lineages of phytophagous arthropods. Antiquity of the gall mites in much their extant form was unexpected, particularly with the Triassic species already having many of their present-day features (such as only two pairs of legs); further, it establishes conifer feeding as an ancestral trait. Feeding by the fossil mites may have contributed to the formation of the amber droplets, but we find that the abundance of amber during the Carnian (ca. 230 Ma) is globally anomalous for the pre-Cretaceous and may, alternatively, be related to paleoclimate. Further recovery of arthropods in Carnian-aged amber is promising and will have profound implications for understanding the evolution of terrestrial members of the most diverse phylum of organisms. PMID:22927387

  3. Arthropods in amber from the Triassic Period.

    PubMed

    Schmidt, Alexander R; Jancke, Saskia; Lindquist, Evert E; Ragazzi, Eugenio; Roghi, Guido; Nascimbene, Paul C; Schmidt, Kerstin; Wappler, Torsten; Grimaldi, David A

    2012-09-11

    The occurrence of arthropods in amber exclusively from the Cretaceous and Cenozoic is widely regarded to be a result of the production and preservation of large amounts of tree resin beginning ca. 130 million years (Ma) ago. Abundant 230 million-year-old amber from the Late Triassic (Carnian) of northeastern Italy has previously yielded myriad microorganisms, but we report here that it also preserves arthropods some 100 Ma older than the earliest prior records in amber. The Triassic specimens are a nematoceran fly (Diptera) and two disparate species of mites, Triasacarus fedelei gen. et sp. nov., and Ampezzoa triassica gen. et sp. nov. These mites are the oldest definitive fossils of a group, the Eriophyoidea, which includes the gall mites and comprises at least 3,500 Recent species, 97% of which feed on angiosperms and represents one of the most specialized lineages of phytophagous arthropods. Antiquity of the gall mites in much their extant form was unexpected, particularly with the Triassic species already having many of their present-day features (such as only two pairs of legs); further, it establishes conifer feeding as an ancestral trait. Feeding by the fossil mites may have contributed to the formation of the amber droplets, but we find that the abundance of amber during the Carnian (ca. 230 Ma) is globally anomalous for the pre-Cretaceous and may, alternatively, be related to paleoclimate. Further recovery of arthropods in Carnian-aged amber is promising and will have profound implications for understanding the evolution of terrestrial members of the most diverse phylum of organisms. PMID:22927387

  4. Arthropod-borne bacterial diseases in pregnancy.

    PubMed

    Dotters-Katz, Sarah K; Kuller, Jeffrey; Heine, R Phillips

    2013-09-01

    Arthropod-borne bacterial diseases affect more than 25,000 Americans every year and thousands more around the world. These infections present a diagnostic dilemma for clinicians because they mimic many other pathologic conditions and are often low on or absent from the differential diagnosis list. Diagnosis is particularly challenging during pregnancy, as these infections may mimic common pregnancy-specific conditions, such as typical and atypical preeclampsia, or symptoms of pregnancy itself. Concerns regarding the safety in pregnancy of some indicated antibiotics add a therapeutic challenge for the prescriber, requiring knowledge of alternative therapeutic options for many arthropod-borne bacterial diseases. Physicians, especially those in endemic areas, must keep this class of infections in mind, particularly when the presentation does not appear classic for more commonly seen conditions. This article discusses presentation, diagnosis, and treatment of the most common of these arthropod-borne bacterial diseases, including Lyme disease, Rocky Mountain spotted fever, tick-borne relapsing fever, typhus, plague, cat-scratch disease, and Carrión disease. PMID:25102120

  5. Arthropod community organization and development in pear

    NASA Astrophysics Data System (ADS)

    Gut, Larry J.; Liss, W. J.; Westigard, P. H.

    1991-01-01

    Arthropod communities in pear are conceptualized as hierarchically organized systems in which several levels of organization or subsystems can be recognized between the population level and the community as a whole. An individual pear tree is taken to be the community habitat with arthropod subcommunities developing on leaf, fruit, and wood subcommunity habitats. Each subcommunity is composed of trophically organized systems of populations. Each system of populations is comprised of a functional group or guild of phytophagous arthropods that use the habitat primarily for feeding but also for overwintering or egg deposition, and associated groups of specialized predators, parasitoids, and hyperparasitoids. Several species move from one subcommunity to another during the course of community development and thus integrate community subsystems. Community development or change in organization through time is conceptualized as being jointly determined by the development of the habitat and the organization of the species pool. The influence of habitat development on community development within a species pool is emphasized in this research. Seasonal habitat development is expressed as change in the kinds and biomasses of developmental states of wood, leaf, and fruit subcommunity habitats. These changes are accompanied by changes in the kinds, biomasses, and distributions of associated community subsystems.

  6. Communication.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

    This theme issue on communication includes annotated listings of Web sites, CD-ROM and computer software, videos, books, and professional resources that deal with various methods of communication. Sidebars discuss mythology, photojournalism, sharing ideas on the Web, and songs of protest. Suggestions for class activities are also included. (LRW)

  7. Communication

    NASA Technical Reports Server (NTRS)

    Griner, James

    2010-01-01

    NASA s communication work for the UAS Command and Control area will build upon work currently being conducted under NASA Recovery Act funds. Communication portions of UAS NextGen ConOps, Stateof- the-Art assessment, and Gap Analysis. Preliminary simulations for UAS CNPC link scalability assessment. Surrogate UAS aircraft upgrades. This work will also leverage FY10 in-guide funding for communication link model development. UAS are currently managed through exceptions and are operating using DoD frequencies for line-of-sight (LOS) and satellite-based communications links, low-power LOS links in amateur bands, or unlicensed Instrument/Scientific/Medical (ISM) frequencies. None of these frequency bands are designated for Safety and Regularity of Flight. No radio-frequency (RF) spectrum has been allocated by the International Telecommunications Union (ITU) specifically for UAS command and control links, for either LOS or Beyond LOS (BLOS) communication.

  8. Short-term intensive glycemic control improves vibratory sensation in type 2 diabetes.

    PubMed

    Fujita, Yoshihito; Fukushima, Mitsuo; Suzuki, Haruhiko; Taniguchi, Ataru; Nakai, Yoshikatsu; Kuroe, Akira; Yasuda, Koichiro; Hosokawa, Masaya; Yamada, Yuichiro; Inagaki, Nobuya; Seino, Yutaka

    2008-04-01

    Strict long-term glycemic control has been reported to prevent or improve diabetic peripheral neuropathy, but the effects of short-term glycemic control have not been clarified in patients with type 2 diabetes. To investigate reversibility of impaired vibratory sensation by short-term glycemic control, we used the TM31 liminometer and C64 tuning fork methods to measure peripheral neuropathy. Thirty-one type 2 diabetes patients with poor glycemic control (HbA1c: 10.8+/-0.4%, mean+/-S.E.M., range from 7.9% to 16.2%) were administered strict glycemic control. Vibratory sensation before and after short-term glycemic control was evaluated, and the metabolic profile including plasma glucose, HbA1c, total cholesterol, HDL cholesterol, triglyceride, and free fatty acid (FFA) was measured. After 20.0+/-2.1 days of strict glycemic control, vibratory sensation improved significantly in both upper and lower extremities, assessed by TM31 liminometer and C64 tuning fork. Along with the improved glycemic control, lipid metabolism (total cholesterol, triglyceride and FFA) was significantly improved. Thus, short-term intensive glycemic control can improve vibratory sensation, metabolic changes in glucose and lipid metabolism being the factors responsible for improved of peripheral nerve function. PMID:18262304

  9. Automated Measurement of Vocal Fold Vibratory Asymmetry from High-Speed Videoendoscopy Recordings

    ERIC Educational Resources Information Center

    Mehta, Daryush D.; Deliyski, Dimitar D.; Quatieri, Thomas F.; Hillman, Robert E.

    2011-01-01

    Purpose: In prior work, a manually derived measure of vocal fold vibratory phase asymmetry correlated to varying degrees with visual judgments made from laryngeal high-speed videoendoscopy (HSV) recordings. This investigation extended this work by establishing an automated HSV-based framework to quantify 3 categories of vocal fold vibratory…

  10. Assessment of Penile Vibratory Stimulation as a Management Strategy in Men with Secondary Retarded Orgasm

    PubMed Central

    Nelson, Christian J.; Ahmed, Absaar; Valenzuela, Rolando; Parker, Marilyn; Mulhall, John P.

    2016-01-01

    OBJECTIVES To evaluate the effectiveness of penile vibratory stimulation for the management of retarded orgasm. Retarded orgasm, a condition characterized by difficulty achieving orgasm and ejaculation, is one of the most recalcitrant of the male sexual dysfunctions. Currently, no evidence-based treatments have been proven to ameliorate this condition. METHODS Men who had a complete inability to achieve an orgasm during sexual relations in the previous 3 months were instructed in the use of penile vibratory stimulation. The men’s responses were measured by self-report of orgasm function and using the orgasm and satisfaction domains of the International Index of Erectile Function. The responses were assessed at baseline (admission into the study) and at 3 and 6 months. RESULTS A total of 36 men met the inclusion criteria, and 72% reported the restoration of orgasm. These responders reported that orgasm during sexual relations occurred 62% of the time. A statistically and clinically significant increase occurred in the orgasm and satisfaction domains of the International Index of Erectile Function between the baseline visit and the 3-month follow-up visit. These gains were sustained at 6 months. CONCLUSIONS Penile vibratory stimulation is an effective treatment for retarded orgasm. Penile vibratory stimulation should be integrated into current cognitive-behavioral sex therapy techniques to achieve maximal effectiveness and satisfaction. PMID:17382163

  11. Characterizing Vibratory Kinematics in Children and Adults with High-Speed Digital Imaging

    ERIC Educational Resources Information Center

    Patel, Rita; Dubrovskiy, Denis; Döllinger, Michael

    2014-01-01

    Purpose: The aim of this study is to quantify and identify characteristic vibratory motion in typically developing prepubertal children and young adults using high-speed digital imaging. Method: The vibrations of the vocal folds were recorded from 27 children (ages 5-9 years) and 35 adults (ages 21-45 years), with high speed at 4,000 frames per…

  12. Research on the Signal Process of a Bell-Shaped Vibratory Angular Rate Gyro

    PubMed Central

    Su, Zhong; Liu, Ning; Li, Qing; Fu, Mengyin; Liu, Hong; Fan, Junfang

    2014-01-01

    A bell-shaped vibratory angular rate gyro, which is inspired by the Chinese traditional bell, is a kind of axisymmetric shell resonator gyroscope. Its sensitive element is a vibratory-like Chinese traditional bell, using a piezoelectric element on the wall of the vibrator to detect the standing wave's precession to solve the input angular rate. This work mainly studies the circuit system of a bell-shaped vibratory angular rate gyro. It discusses the process of circuit system design, analysis and experiment, in detail, providing the foundation to develop a bell-shaped vibratory angular rate gyro. Since the bell-shaped resonator's curved structure has the characteristics of large noise in the piezoelectric signal and large harmonics, this paper analyzes its working and signal detection method, then gives the whole plan of the circuit system, including the drive module, the detection module and the control loop. It also studies every part of the whole system, gives a detailed design and analysis process and proves part of the circuit system using digital simulation. At the end of the article, the test result of the circuit system shows that it can remove the disadvantages of the curved structure having large noise in the piezoelectric signal and large harmonics and is more effective at solving the input angular rate. PMID:24633451

  13. Bacterial symbiosis in arthropods and the control of disease transmission.

    PubMed Central

    Beard, C. B.; Durvasula, R. V.; Richards, F. F.

    1998-01-01

    Bacterial symbionts may be used as vehicles for expressing foreign genes in arthropods. Expression of selected genes can render an arthropod incapable of transmitting a second microorganism that is pathogenic for humans and is an alternative approach to the control of arthropod-borne diseases. We discuss the rationale for this alternative approach, its potential applications and limitations, and the regulatory concerns that may arise from its use in interrupting disease transmission in humans and animals. PMID:9866734

  14. How Did Arthropod Sesquiterpenoids and Ecdysteroids Arise? Comparison of Hormonal Pathway Genes in Noninsect Arthropod Genomes

    PubMed Central

    Qu, Zhe; Kenny, Nathan James; Lam, Hon Ming; Chan, Ting Fung; Chu, Ka Hou; Bendena, William G.; Tobe, Stephen S.; Hui, Jerome Ho Lam

    2015-01-01

    The phylum Arthropoda contains the largest number of described living animal species, with insects and crustaceans dominating the terrestrial and aquatic environments, respectively. Their successful radiations have long been linked to their rigid exoskeleton in conjunction with their specialized endocrine systems. In order to understand how hormones can contribute to the evolution of these animals, here, we have categorized the sesquiterpenoid and ecdysteroid pathway genes in the noninsect arthropod genomes, which are known to play important roles in the regulation of molting and metamorphosis in insects. In our analyses, the majority of gene homologs involved in the biosynthetic, degradative, and signaling pathways of sesquiterpenoids and ecdysteroids can be identified, implying these two hormonal systems were present in the last common ancestor of arthropods. Moreover, we found that the “Broad-Complex” was specifically gained in the Pancrustacea, and the innovation of juvenile hormone (JH) in the insect linage correlates with the gain of the JH epoxidase (CYP15A1/C1) and the key residue changes in the binding domain of JH receptor (“Methoprene-tolerant”). Furthermore, the gain of “Phantom” differentiates chelicerates from the other arthropods in using ponasterone A rather than 20-hydroxyecdysone as molting hormone. This study establishes a comprehensive framework for interpreting the evolution of these vital hormonal pathways in these most successful animals, the arthropods, for the first time. PMID:26112967

  15. How Did Arthropod Sesquiterpenoids and Ecdysteroids Arise? Comparison of Hormonal Pathway Genes in Noninsect Arthropod Genomes.

    PubMed

    Qu, Zhe; Kenny, Nathan James; Lam, Hon Ming; Chan, Ting Fung; Chu, Ka Hou; Bendena, William G; Tobe, Stephen S; Hui, Jerome Ho Lam

    2015-07-01

    The phylum Arthropoda contains the largest number of described living animal species, with insects and crustaceans dominating the terrestrial and aquatic environments, respectively. Their successful radiations have long been linked to their rigid exoskeleton in conjunction with their specialized endocrine systems. In order to understand how hormones can contribute to the evolution of these animals, here, we have categorized the sesquiterpenoid and ecdysteroid pathway genes in the noninsect arthropod genomes, which are known to play important roles in the regulation of molting and metamorphosis in insects. In our analyses, the majority of gene homologs involved in the biosynthetic, degradative, and signaling pathways of sesquiterpenoids and ecdysteroids can be identified, implying these two hormonal systems were present in the last common ancestor of arthropods. Moreover, we found that the "Broad-Complex" was specifically gained in the Pancrustacea, and the innovation of juvenile hormone (JH) in the insect linage correlates with the gain of the JH epoxidase (CYP15A1/C1) and the key residue changes in the binding domain of JH receptor ("Methoprene-tolerant"). Furthermore, the gain of "Phantom" differentiates chelicerates from the other arthropods in using ponasterone A rather than 20-hydroxyecdysone as molting hormone. This study establishes a comprehensive framework for interpreting the evolution of these vital hormonal pathways in these most successful animals, the arthropods, for the first time. PMID:26112967

  16. Biobased lactams as novel arthropod repellents.

    PubMed

    Chauhan, Kamlesh R; Khanna, Hemant; Bathini, Nagendra Babu; Le, Thanh C; Grieco, John

    2014-12-01

    Enanatiomerically pure 4aS,7S,7aR and 4aS,7S,7aS-nepetalactams and their analogs have been prepared in just two steps from 4aS,7S,7aR and 4aS,7S,7aS-nepetalactones, major components of catnip oil. Lactams or cyclic amides from iridoid monoterpenes are generated and being evaluated as a new class of compounds as arthropod deterrents against disease vectors. PMID:25632454

  17. Leaving A Mark: A Comparison Arthropod Protein Marking Protocols

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge of arthropod pest and natural enemy disperal patterns is needed for effective and environmentally benign pest control. The most common tactics used to monitor arthropod dispersal patterns include mark-release-recapture (MRR) and mark-capture methodologies. Both methods require the applica...

  18. Communications

    ERIC Educational Resources Information Center

    Bailenson, Jeremy; Buzzanell, Patrice; Deetz, Stanley; Tewksbury, David; Thompson, Robert J.; Turow, Joseph; Bichelmeyer, Barbara; Bishop, M. J.; Gayeski, Diane

    2013-01-01

    Scholars representing the field of communications were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Jeremy Bailenson, Patrice Buzzanell, Stanley Deetz, David Tewksbury, Robert J. Thompson, and…

  19. Communications

    NASA Technical Reports Server (NTRS)

    Hathorn, S.

    1985-01-01

    An overview of NASA's Thin Route satellite telecommunication project is presented. Thin Route employs applications technology satellites (ATS) in place of more costly commercial multi- transponder telecommunications satellites. This system allows remote and underdeveloped areas to communicate with the outside world for purposes of obtaining medical assistance among other things. The system represents a substantial cost saving over commercial systems.

  20. A molecular palaeobiological exploration of arthropod terrestrialization.

    PubMed

    Lozano-Fernandez, Jesus; Carton, Robert; Tanner, Alastair R; Puttick, Mark N; Blaxter, Mark; Vinther, Jakob; Olesen, Jørgen; Giribet, Gonzalo; Edgecombe, Gregory D; Pisani, Davide

    2016-07-19

    Understanding animal terrestrialization, the process through which animals colonized the land, is crucial to clarify extant biodiversity and biological adaptation. Arthropoda (insects, spiders, centipedes and their allies) represent the largest majority of terrestrial biodiversity. Here we implemented a molecular palaeobiological approach, merging molecular and fossil evidence, to elucidate the deepest history of the terrestrial arthropods. We focused on the three independent, Palaeozoic arthropod terrestrialization events (those of Myriapoda, Hexapoda and Arachnida) and showed that a marine route to the colonization of land is the most likely scenario. Molecular clock analyses confirmed an origin for the three terrestrial lineages bracketed between the Cambrian and the Silurian. While molecular divergence times for Arachnida are consistent with the fossil record, Myriapoda are inferred to have colonized land earlier, substantially predating trace or body fossil evidence. An estimated origin of myriapods by the Early Cambrian precedes the appearance of embryophytes and perhaps even terrestrial fungi, raising the possibility that terrestrialization had independent origins in crown-group myriapod lineages, consistent with morphological arguments for convergence in tracheal systems.This article is part of the themed issue 'Dating species divergences using rocks and clocks'. PMID:27325830

  1. A Silurian short-great-appendage arthropod

    PubMed Central

    Siveter, Derek J.; Briggs, Derek E. G.; Siveter, David J.; Sutton, Mark D.; Legg, David; Joomun, Sarah

    2014-01-01

    A new arthropod, Enalikter aphson gen. et sp. nov., is described from the Silurian (Wenlock Series) Herefordshire Lagerstätte of the UK. It belongs to the Megacheira (=short-great-appendage group), which is recognized here, for the first time, in strata younger than mid-Cambrian age. Discovery of this new Silurian taxon allows us to identify a Devonian megacheiran representative, Bundenbachiellus giganteus from the Hunsrück Slate of Germany. The phylogenetic position of megacheirans is controversial: they have been interpreted as stem chelicerates, or stem euarthropods, but when Enalikter and Bundenbachiellus are added to the most comprehensive morphological database available, a stem euarthropod position is supported. Enalikter represents the only fully three-dimensionally preserved stem-group euarthropod, it falls in the sister clade to the crown-group euarthropods, and it provides new insights surrounding the origin and early evolution of the euarthropods. Recognition of Enalikter and Bundenbachiellus as megacheirans indicates that this major arthropod group survived for nearly 100 Myr beyond the mid-Cambrian. PMID:24452026

  2. Visual orientation and navigation in nocturnal arthropods.

    PubMed

    Warrant, Eric; Dacke, Marie

    2010-01-01

    With their highly sensitive visual systems, the arthropods have evolved a remarkable capacity to orient and navigate at night. Whereas some navigate under the open sky, and take full advantage of the celestial cues available there, others navigate in more difficult conditions, such as through the dense understory of a tropical rainforest. Four major classes of orientation are performed by arthropods at night, some of which involve true navigation (i.e. travel to a distant goal that lies beyond the range of direct sensory contact): (1) simple straight-line orientation, typically for escape purposes; (2) nightly short-distance movements relative to a shoreline, typically in the context of feeding; (3) long-distance nocturnal migration at high altitude in the quest to locate favorable feeding or breeding sites, and (4) nocturnal excursions to and from a fixed nest or food site (i.e. homing), a task that in most species involves path integration and/or the learning and recollection of visual landmarks. These four classes of orientation--and their visual basis--are reviewed here, with special emphasis given to the best-understood animal systems that are representative of each. PMID:20733292

  3. A molecular palaeobiological exploration of arthropod terrestrialization

    PubMed Central

    Carton, Robert; Edgecombe, Gregory D.

    2016-01-01

    Understanding animal terrestrialization, the process through which animals colonized the land, is crucial to clarify extant biodiversity and biological adaptation. Arthropoda (insects, spiders, centipedes and their allies) represent the largest majority of terrestrial biodiversity. Here we implemented a molecular palaeobiological approach, merging molecular and fossil evidence, to elucidate the deepest history of the terrestrial arthropods. We focused on the three independent, Palaeozoic arthropod terrestrialization events (those of Myriapoda, Hexapoda and Arachnida) and showed that a marine route to the colonization of land is the most likely scenario. Molecular clock analyses confirmed an origin for the three terrestrial lineages bracketed between the Cambrian and the Silurian. While molecular divergence times for Arachnida are consistent with the fossil record, Myriapoda are inferred to have colonized land earlier, substantially predating trace or body fossil evidence. An estimated origin of myriapods by the Early Cambrian precedes the appearance of embryophytes and perhaps even terrestrial fungi, raising the possibility that terrestrialization had independent origins in crown-group myriapod lineages, consistent with morphological arguments for convergence in tracheal systems. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’. PMID:27325830

  4. Hematopoiesis and hematopoietic organs in arthropods.

    PubMed

    Grigorian, Melina; Hartenstein, Volker

    2013-03-01

    Hemocytes (blood cells) are motile cells that move throughout the extracellular space and that exist in all clades of the animal kingdom. Hemocytes play an important role in shaping the extracellular environment and in the immune response. Developmentally, hemocytes are closely related to the epithelial cells lining the vascular system (endothelia) and the body cavity (mesothelia). In vertebrates and insects, common progenitors, called hemangioblasts, give rise to the endothelia and blood cells. In the adult animal, many differentiated hemocytes seem to retain the ability to proliferate; however, in most cases investigated closely, the bulk of hemocyte proliferation takes place in specialized hematopoietic organs. Hematopoietic organs provide an environment where undifferentiated blood stem cells are able to self-renew, and at the same time generate offspring that differentiate into different blood cell types. Hematopoiesis in vertebrates, taking place in the bone marrow, has been subject to intensive research by immunologists and stem cell biologists. Much less is known about blood cell formation in invertebrate animals. In this review, we will survey structural and functional properties of invertebrate hematopoietic organs, with a main focus on insects and other arthropod taxa. We will then discuss similarities, at the molecular and structural level, that are apparent when comparing the development of blood cells in hematopoietic organs of vertebrates and arthropods. Our comparative review is intended to elucidate aspects of the biology of blood stem cells that are more easily missed when focusing on one or a few model species. PMID:23319182

  5. Hematopoiesis and Hematopoietic Organs in Arthropods

    PubMed Central

    Grigorian, Melina; Hartenstein, Volker

    2013-01-01

    Hemocytes (blood cells) are motile cells moving throughout the extracellular space and exist in all clades of the animal kingdom. Hemocytes play an important role in shaping the extracellular environment and in the immune response. Developmentally, hemocytes are closely related to the epithelial cells lining the vascular system (endothelia) and body cavity (mesothelia). In vertebrates and insects, common progenitors, called hemangioblasts, give rise to the endothelia and blood cells. In the adult animal, many differentiated hemocytes seem to retain the ability to proliferate; however, in most cases investigated closely, the bulk of hemocyte proliferation takes place in specialized hematopoietic organs. Hematopoietic organs provide an environment where undifferentiated blood stem cells are able to self renew, and at the same time generate offspring that differentiate into different blood cell types. Hematopoiesis in vertebrates, taking place in the bone marrow, has been subject to intensive research by immunologists and stem cell biologists. Much less is known about blood cell formation in invertebrate animals. In this review we will survey structural and functional properties of invertebrate hematopoietic organs, with a main focus on insects and other arthropod taxa. We will then discuss similarities, at the molecular and structural level, that are apparent when comparing the development of blood cells in hematopoietic organs of vertebrates and arthropods. Our comparative review is intended to elucidate aspects of the biology of blood stem cells that are more easily missed when focusing on one or a few model species. PMID:23319182

  6. Effects of large herbivores on grassland arthropod diversity

    PubMed Central

    van Klink, R; van der Plas, F; van Noordwijk, C G E (Toos); WallisDeVries, M F; Olff, H

    2015-01-01

    Both arthropods and large grazing herbivores are important components and drivers of biodiversity in grassland ecosystems, but a synthesis of how arthropod diversity is affected by large herbivores has been largely missing. To fill this gap, we conducted a literature search, which yielded 141 studies on this topic of which 24 simultaneously investigated plant and arthropod diversity. Using the data from these 24 studies, we compared the responses of plant and arthropod diversity to an increase in grazing intensity. This quantitative assessment showed no overall significant effect of increasing grazing intensity on plant diversity, while arthropod diversity was generally negatively affected. To understand these negative effects, we explored the mechanisms by which large herbivores affect arthropod communities: direct effects, changes in vegetation structure, changes in plant community composition, changes in soil conditions, and cascading effects within the arthropod interaction web. We identify three main factors determining the effects of large herbivores on arthropod diversity: (i) unintentional predation and increased disturbance, (ii) decreases in total resource abundance for arthropods (biomass) and (iii) changes in plant diversity, vegetation structure and abiotic conditions. In general, heterogeneity in vegetation structure and abiotic conditions increases at intermediate grazing intensity, but declines at both low and high grazing intensity. We conclude that large herbivores can only increase arthropod diversity if they cause an increase in (a)biotic heterogeneity, and then only if this increase is large enough to compensate for the loss of total resource abundance and the increased mortality rate. This is expected to occur only at low herbivore densities or with spatio-temporal variation in herbivore densities. As we demonstrate that arthropod diversity is often more negatively affected by grazing than plant diversity, we strongly recommend considering the

  7. Effects of large herbivores on grassland arthropod diversity.

    PubMed

    van Klink, R; van der Plas, F; van Noordwijk, C G E Toos; WallisDeVries, M F; Olff, H

    2015-05-01

    Both arthropods and large grazing herbivores are important components and drivers of biodiversity in grassland ecosystems, but a synthesis of how arthropod diversity is affected by large herbivores has been largely missing. To fill this gap, we conducted a literature search, which yielded 141 studies on this topic of which 24 simultaneously investigated plant and arthropod diversity. Using the data from these 24 studies, we compared the responses of plant and arthropod diversity to an increase in grazing intensity. This quantitative assessment showed no overall significant effect of increasing grazing intensity on plant diversity, while arthropod diversity was generally negatively affected. To understand these negative effects, we explored the mechanisms by which large herbivores affect arthropod communities: direct effects, changes in vegetation structure, changes in plant community composition, changes in soil conditions, and cascading effects within the arthropod interaction web. We identify three main factors determining the effects of large herbivores on arthropod diversity: (i) unintentional predation and increased disturbance, (ii) decreases in total resource abundance for arthropods (biomass) and (iii) changes in plant diversity, vegetation structure and abiotic conditions. In general, heterogeneity in vegetation structure and abiotic conditions increases at intermediate grazing intensity, but declines at both low and high grazing intensity. We conclude that large herbivores can only increase arthropod diversity if they cause an increase in (a)biotic heterogeneity, and then only if this increase is large enough to compensate for the loss of total resource abundance and the increased mortality rate. This is expected to occur only at low herbivore densities or with spatio-temporal variation in herbivore densities. As we demonstrate that arthropod diversity is often more negatively affected by grazing than plant diversity, we strongly recommend considering the

  8. Possibility of application of small-size robots with vibratory piezoelectric actuators for inspection of physical state of surfaces

    NASA Astrophysics Data System (ADS)

    Stepanenko, D. A.; Minchenya, V. T.; Asimov, R. M.; Zimmermann, K.

    2012-05-01

    The article describes design and principle of control of small-size inspection robot with vibratory piezoelectric actuator and possibility of its application for non-destructive evaluation (NDE). Controlled movement of robot is implemented using single bimorph piezoelement by means of frequency control of electric voltage applied to piezoelement. Such scheme of control is realized as a result of application of structural asymmetry principle consisting in relative shift of resonant characteristics of robot supporting elements (legs) by means of imparting geometric asymmetry to them. During movement of robot upon inspected surface each of its legs excites in substrate elastic waves which can be registered by another robot as a consequence of piezoelectric effect reversibility. As a result group of communicating robots (robotic swarm) will be able to distribute over the surface of inspected object and perform its multiagent control. This will give possibility to accelerate and simplify inspection of large and geometrically-complex objects. Autonomy and compactness of the described robots will also make reasonable their application for NDE of hard-to-access surfaces and potentially hazardous objects.

  9. Ecotoxicological study of insecticide effects on arthropods in common bean.

    PubMed

    de Barros, Emerson Cristi; Ventura, Hudson Vaner; Gontijo, Pablo Costa; Pereira, Renata Ramos; Picanço, Marcelo Coutinho

    2015-01-01

    Arthropods are an important group of macroorganisms that work to maintain ecosystem health. Despite the agricultural benefits of chemical control against arthropod pests, insecticides can cause environmental damage. We examined the effects of one and two applications of the insecticides chlorfenapyr (0.18 liters a.i. ha-1) and methamidophos (0.45 liters a.i. ha-1), both independently and in combination, on arthropods in plots of common bean. The experiment was repeated for two growing seasons. Principal response curve, richness estimator, and Shannon-Wiener diversity index analyses were performed. The insecticides generally affected the frequency, richness, diversity, and relative abundance of the arthropods. In addition, the arthropods did not experience recovery after the insecticide applications. The results suggest that the insecticide impacts were sufficiently drastic to eliminate many taxa from the studied common bean plots. PMID:25700537

  10. Ecotoxicological Study of Insecticide Effects on Arthropods in Common Bean

    PubMed Central

    de Barros, Emerson Cristi; Ventura, Hudson Vaner; Gontijo, Pablo Costa; Pereira, Renata Ramos; Picanço, Marcelo Coutinho

    2015-01-01

    Arthropods are an important group of macroorganisms that work to maintain ecosystem health. Despite the agricultural benefits of chemical control against arthropod pests, insecticides can cause environmental damage. We examined the effects of one and two applications of the insecticides chlorfenapyr (0.18 liters a.i. ha-1) and methamidophos (0.45 liters a.i. ha-1), both independently and in combination, on arthropods in plots of common bean. The experiment was repeated for two growing seasons. Principal response curve, richness estimator, and Shannon–Wiener diversity index analyses were performed. The insecticides generally affected the frequency, richness, diversity, and relative abundance of the arthropods. In addition, the arthropods did not experience recovery after the insecticide applications. The results suggest that the insecticide impacts were sufficiently drastic to eliminate many taxa from the studied common bean plots. PMID:25700537

  11. Vibratory hub load data reduction and analysis from the reverse velocity rotor wind tunnel test, phase 2B

    NASA Technical Reports Server (NTRS)

    Taylor, R. B.

    1976-01-01

    The vibratory hub loads data analysis from the reverse velocity rotor wind tunnel test is reported. Vibratory loads were obtained from the rotating hub balance and also by synthesis of generalized coordinates from the blade flap bending moments. Load trends were defined as a function of speed, rotor thrust and 2 per rev cyclic from each of the data methods. These trends were compared to determine the degree of agreement between each method and provide substantiation for the generalized coordinate approach.

  12. Vibratory response modeling and verification of a high precision optical positioning system.

    SciTech Connect

    Barraza, J.; Kuzay, T.; Royston, T. J.; Shu, D.

    1999-06-18

    A generic vibratory-response modeling program has been developed as a tool for designing high-precision optical positioning systems. Based on multibody dynamics theory, the system is modeled as rigid-body structures connected by linear elastic elements, such as complex actuators and bearings. The full dynamic properties of each element are determined experimentally or theoretically, then integrated into the program as inertial and stiffness matrices. Utilizing this program, the theoretical and experimental verification of the vibratory behavior of a double-multilayer monochromator support and positioning system is presented. Results of parametric design studies that investigate the influence of support floor dynamics and highlight important design issues are also presented. Overall, good matches between theory and experiment demonstrate the effectiveness of the program as a dynamic modeling tool.

  13. Vibratory Loads Data from a Wind-Tunnel Test of Structurally Tailored Model Helicopter Rotors

    NASA Technical Reports Server (NTRS)

    Yeager, William T., Jr.; Hamouda, M-Nabil H.; Idol, Robert F.; Mirick, Paul H.; Singleton, Jeffrey D.; Wilbur, Matthew L.

    1991-01-01

    An experimental study was conducted in the Langley Transonic Dynamics Tunnel to investigate the use of a Bell Helicopter Textron (BHT) rotor structural tailoring concept, known as rotor nodalization, in conjunction with advanced blade aerodynamics as well as to evaluate rotor blade aerodynamic design methodologies. A 1/5-size, four-bladed bearingless hub, three sets of Mach-scaled model rotor blades were tested in forward flight from transition up to an advance ratio of 0.35. The data presented pertain only to the evaluation of the structural tailoring concept and consist of fixed-system and rotating system vibratory loads. These data will be useful for evaluating the effects of tailoring blade structural properties on fixed-system vibratory loads, as well as validating analyses used in the design of advanced rotor systems.

  14. Effect of changing speckles in digital holography on measurements of static and vibratory displacements.

    PubMed

    Stetson, Karl A

    2016-06-01

    This paper presents a study of speckle effects in measurements of static and vibratory displacements by digital holography. Such effects are shown to arise from changes in speckle fields that often occur between holographic recordings. These may be between recording holograms before and after static deformations or changes in sets of holograms recorded for vibration measurement. If the images do not change between such recordings, the effects appear to be limited mainly to round-off errors. PMID:27411207

  15. Recovery of Vibratory Function After Vocal Fold Microflap in a Rabbit Model

    PubMed Central

    Kojima, Tsuyoshi; Mitchell, Joshua R.; Garrett, C. Gaelyn; Rousseau, Bernard

    2015-01-01

    Objectives/Hypothesis The purpose of this study was to evaluate the return of vibratory function and restoration of vibration amplitude and symmetry after vocal fold microflap surgery. Study Design Prospective in vivo animal model. Methods Microflap surgery was performed on 30 New Zealand white breeder rabbits. The left vocal fold received a 3-mm epithelial incision and mucosal elevation, while the contralateral vocal fold was left intact to serve as an internal control. Quantitative analysis of amplitude ratio and lateral phase difference were measured using high-speed laryngeal imaging at a frame rate of 10,000 frames per second from animals undergoing evoked phonation on postoperative days 0, 1, 3, 5, and 7. Results Quantitative measures revealed a significantly reduced amplitude ratio and lateral phase difference on day 0 after microflap. These impairments of vibratory function on day 0 were associated with separation of the vocal fold’s bodycover layer. Amplitude ratio increased significantly by day 3 after microflap, with further increases in vibration amplitude on days 5 and 7. While the amplitude ratio improved significantly on day 3, lateral phase difference decreased significantly on day 3, and returned to normal on days 5 and 7. Conclusions High-speed laryngeal imaging was used to investigate the natural time course of postmicroflap recovery of vibratory function. Results revealed the restoration of vibration amplitude and lateral phase difference by days 3 to 7 after microflap. The time period of improved vibratory function observed in this study coincides with the end of the well-documented inflammatory phase of vocal fold wound repair. PMID:23901003

  16. Hydrostatic Vibratory Drive of the Test Stand for Excitation of the Amplitude-Modulated Vibrations

    NASA Astrophysics Data System (ADS)

    Nizhegorodov, A. I.; Gavrilin, A. N.; Moyzes, B. B.

    2016-01-01

    The article reviews the problems arising during the development of the test stand hydrostatic vibratory drive, which synthesize controlled amplitude-modulated vibrations required testing of vibration strength and vibrostability of technological devices. The newly developed modification can adequately simulate the transport vibration and vibration of the operating power-supply units of technological machinery vibration by means of implementing of a continuous frequency spectrum of the vibration exposure in the desired frequency range.

  17. Mechanical Assessment of the Drep Shield Subject to Vibratory Motion and Dynamic and Static Rock Loading

    SciTech Connect

    R.C. Quittmeyer

    2005-11-16

    The purpose of the drip shield (DS) is to divert water that may seep into emplacement drifts from contacting the waste packages, and to protect the waste packages from impact or static loading from rockfall. The objective of this document is to summarize, into one location, the results of a series of supporting engineering calculations that were developed to study the effect of static and dynamic loads on the mechanical performance of the DS. The potential DS loads are a result of: (1) Potential earthquake vibratory ground motion, and resulting interaction of the DS, waste package and pallet, and drift invert; (2) Dynamic impacts of rockfall resulting from emplacement drift damage as a result of earthquake vibratory motion; and (3) Static load of the caved rock rubble that may come to rest on the DS as a result of vibratory motion or from time-dependent yielding of the rock mass surrounding the emplacement drift. The potential mechanical failure mechanisms that may result from these loads include: (1) Overturning and/or separation of the interlocking DS segments; (2) Loss of structural integrity and stability of the DS, including excessive deformation or buckling; and (3) Localized damage to the top and side-wall plates of the DS. The scope of this document is limited to summarizing results presented in the supporting calculations in the areas of analysis of the potential for DS collapse, and determination of the damaged surface area of the DS plates. New calculations are presented to determine whether or not separation of DSs occur under vibratory motion.

  18. Gearbox fault diagnosis based on deep random forest fusion of acoustic and vibratory signals

    NASA Astrophysics Data System (ADS)

    Li, Chuan; Sanchez, René-Vinicio; Zurita, Grover; Cerrada, Mariela; Cabrera, Diego; Vásquez, Rafael E.

    2016-08-01

    Fault diagnosis is an effective tool to guarantee safe operations in gearboxes. Acoustic and vibratory measurements in such mechanical devices are all sensitive to the existence of faults. This work addresses the use of a deep random forest fusion (DRFF) technique to improve fault diagnosis performance for gearboxes by using measurements of an acoustic emission (AE) sensor and an accelerometer that are used for monitoring the gearbox condition simultaneously. The statistical parameters of the wavelet packet transform (WPT) are first produced from the AE signal and the vibratory signal, respectively. Two deep Boltzmann machines (DBMs) are then developed for deep representations of the WPT statistical parameters. A random forest is finally suggested to fuse the outputs of the two DBMs as the integrated DRFF model. The proposed DRFF technique is evaluated using gearbox fault diagnosis experiments under different operational conditions, and achieves 97.68% of the classification rate for 11 different condition patterns. Compared to other peer algorithms, the addressed method exhibits the best performance. The results indicate that the deep learning fusion of acoustic and vibratory signals may improve fault diagnosis capabilities for gearboxes.

  19. Vibratory perception thresholds at the clavicle in patients with spinal cord injury.

    PubMed Central

    Herszkowicz, I; Berić, A; Lindblom, U

    1986-01-01

    Vibratory perception thresholds were measured by an electromagnetic device applied over the clavicles of 64 patients with spinal cord injuries. Patients with neurological levels of C5 and below had low threshold values (0.63 +/- 0.23 micron of vibration amplitude; mean +/- SD) which were used as reference values. The patients with a neurological level of C1/2 had very high vibratory thresholds bilaterally (above 11.0 micron). Patients with C2/3-3/4 neurological levels also had significantly elevated thresholds (2.56 +/- 2.01 micron), while those with C4-C4/5 levels did not differ significantly from the reference group. The results agree with earlier observations that the C4 segment innervates the clavicle and imply that patients with a lesion at or above C4 may have elevated clavicular vibratory thresholds. It is concluded that vibrametry, a non-invasive technique, is applicable in patients with spinal cord injury and disease, and can be useful for assessment of sensory level and particularly for follow-up of such patients. PMID:3760897

  20. Simulation of surface EMG for the analysis of muscle activity during whole body vibratory stimulation.

    PubMed

    Fratini, Antonio; Bifulco, Paolo; Romano, Maria; Clemente, Fabrizio; Cesarelli, Mario

    2014-01-01

    This study aims to reproduce the effect of motor-unit synchronization on surface EMG recordings during vibratory stimulation to highlight vibration evoked muscle activity. The authors intended to evaluate, through numerical simulations, the changes in surface EMG spectrum in muscles undergoing whole body vibration stimulation. In some specific bands, in fact, vibration induced motion artifacts are also typically present. In addition, authors meant to compare the simulated EMGs with respect to real recordings in order to discriminate the effect of synchronization of motor units discharges with vibration frequencies from motion artifacts. Computations were performed using a model derived from previous studies and modified to consider the effect of vibratory stimulus, the motor unit synchronization and the endplates-electrodes relative position on the EMG signal. Results revealed that, in particular conditions, synchronization of MUs' discharge generates visible peaks at stimulation frequency and its harmonics. However, only a part of the total power of surface EMGs might be enclosed within artifacts related bands (± 1 Hz centered at the stimulation frequency and its superior harmonics) even in case of strong synchronization of motor units discharges with the vibratory stimulus. PMID:24183387

  1. Effects of vibratory stimulation-induced kinesthetic illusions on the neural activities of patients with stroke

    PubMed Central

    Kodama, Takayuki; Nakano, Hideki; Ohsugi, Hironori; Murata, Shin

    2016-01-01

    [Purpose] This study evaluated the influence of vibratory stimulation-induced kinesthetic illusion on brain function after stroke. [Subjects] Twelve healthy individuals and 13 stroke patients without motor or sensory loss participated. [Methods] Electroencephalograms were taken at rest and during vibratory stimulation. As a neurophysiological index of brain function, we measured the μ-rhythm, which is present mainly in the kinesthetic cortex and is attenuated by movement or motor imagery and compared the data using source localization analyses in the Standardized Low Resolution Brain Electromagnetic Tomography (sLORETA) program. [Results] At rest, μ-rhythms appeared in the sensorimotor and supplementary motor cortices in both healthy controls and stroke patients. Under vibratory stimulation, no μ-rhythm appeared in the sensorimotor cortex of either group. Moreover, in the supplementary motor area, which stores the motor imagery required for kinesthetic illusions, the μ-rhythms of patients were significantly stronger than those of the controls, although the μ-rhythms of both groups were reduced. Thus, differences in neural activity in the supplementary motor area were apparent between the subject groups. [Conclusion] Kinesthetic illusions do occur in patients with motor deficits due to stroke. The neural basis of the supplementary motor area in stroke patients may be functionally different from that found in healthy controls. PMID:27065525

  2. Research on Bell-Shaped Vibratory Angular Rate Gyro's Character of Resonator

    PubMed Central

    Su, Zhong; Fu, Mengyin; Li, Qing; Liu, Ning; Liu, Hong

    2013-01-01

    Bell-shaped vibratory angular rate gyro (abbreviated as BVG) is a new type Coriolis vibratory gyro that was inspired by Chinese traditional clocks. The resonator fuses based on a variable thickness axisymmetric multicurved surface shell. Its characteristics can directly influence the performance of BVG. The BVG structure not only has capabilities of bearing high overload, high impact and, compared with the tuning fork, vibrating beam, shell and a comb structure, but also a higher frequency to overcome the influence of the disturbance of the exterior environment than the same sized hemispherical resonator gyroscope (HRG) and the traditional cylinder vibratory gyroscope. It can be widely applied in high dynamic low precision angular rate measurement occasions. The main work is as follows: the issue mainly analyzes the structure and basic principle, and investigates the bell-shaped resonator's mathematical model. The reasonable structural parameters are obtained from finite element analysis and an intelligent platform. Using the current solid vibration gyro theory analyzes the structural characteristics and principles of BVG. The bell-shaped resonator is simplified as a paraboloid of the revolution mechanical model, which has a fixed closed end and a free opened end. It obtains the natural frequency and vibration modes based on the theory of elasticity. The structural parameters are obtained from the orthogonal method by the research on the structural parameters of the resonator analysis. It obtains the modal analysis, stress analysis and impact analysis with the chosen parameters. Finally, using the turntable experiment verifies the gyro effect of the BVG. PMID:23575033

  3. Prediction of turbine blade vibratory response due to upstream vane distress

    SciTech Connect

    Panovsky, J.; Carson, S.M.

    1998-07-01

    Turbine blades and vanes operate in a hostile environment, which leads to deterioration of these components over time. This paper describes detailed calculations to predict the vibratory response of a high-pressure turbine blade due to the excitation produced by a single distressed upstream vane in a modern turbofan engine. The approach includes detailed computational fluid dynamics (CFD) analysis of the steady flowfield produced by the distressed vane, Fourier decomposition of the flow variables to determine the harmonic content, unsteady CFD analysis to determine the resulting vibratory response of the blade, and crack propagation analysis to determine blade life. Predictions of vibratory stress and threshold crack size are summarized as functions of vane distress level. The results, which indicate that this type of vane distress can indeed be a significant excitation source for the blades, are shown to be in good agreement with engine experience. The method provides, for the first time, a quantitative approach to setting limits for acceptable levels of vane distress in the field.

  4. Arthropod-borne encephalitides in the Americas*

    PubMed Central

    Monath, T. P.

    1979-01-01

    The arthropod-borne encephalitides are an important cause of equine and human morbidity in the Americas. Between 1975 and 1978, 6970 human cases of arboviral encephalitis were reported in the United States of America; however, this represents only a fraction of the true incidence. St Louis encephalitis (4824 cases), California encephalitis (1035 cases), and western equine encephalitis (WEE, 947 cases) accounted for 98.5% of all reported infections. Approximately 1000-4000 cases of equine encephalitis occur annually in the United States, the majority due to WEE. In tropical America, important outbreaks of Venezuelan, eastern, and western equine encephalitis, and of Rocio encephalitis have occurred. In this article, epidemiological aspects of arboviral encephalitis outbreaks occurring within the past 5 years are reviewed. In addition, summaries of current research activities on the ecology and epidemiology of St Louis, western equine, Venezuelan equine, Rocio, and California encephalitis viruses are presented, and the problem of control of these infections is discussed. PMID:93518

  5. An effective method for terrestrial arthropod euthanasia.

    PubMed

    Bennie, Neil A C; Loaring, Christopher D; Bennie, Mikaella M G; Trim, Steven A

    2012-12-15

    As scientific understanding of invertebrate life increases, so does the concern for how to end that life in an effective way that minimises (potential) suffering and is also safe for those carrying out the procedure. There is increasing debate on the most appropriate euthanasia methods for invertebrates as their use in experimental research and zoological institutions grows. Their popularity as pet species has also led to an increase in the need for greater veterinary understanding. Through the use of a local injection of potassium chloride (KCl) initially developed for use in American lobsters, this paper describes a safe and effective method for euthanasia in terrestrial invertebrates. Initial work focused on empirically determining the dose for cockroaches, which was then extrapolated to other arthropod species. For this method of euthanasia, we propose the term 'targeted hyperkalosis' to describe death through terminal depolarisation of the thoracic ganglia as a result of high potassium concentration. PMID:22996446

  6. Ecdysis triggering hormone signaling in arthropods.

    PubMed

    Roller, Ladislav; Zitnanová, Inka; Dai, Li; Simo, Ladislav; Park, Yoonseong; Satake, Honoo; Tanaka, Yoshiaki; Adams, Michael E; Zitnan, Dusan

    2010-03-01

    Ecdysis triggering hormones (ETHs) from endocrine Inka cells initiate the ecdysis sequence through action on central neurons expressing ETH receptors (ETHR) in model moth and dipteran species. We used various biochemical, molecular and BLAST search techniques to detect these signaling molecules in representatives of diverse arthropods. Using peptide isolation from tracheal extracts, cDNA cloning or homology searches, we identified ETHs in a variety of hemimetabolous and holometabolous insects. Most insects produce two related ETHs, but only a single active peptide was isolated from the cricket and one peptide is encoded by the eth gene of the honeybee, parasitic wasp and aphid. Immunohistochemical staining with antiserum to Manduca PETH revealed Inka cells on tracheal surface of diverse insects. In spite of conserved ETH sequences, comparison of natural and the ETH-induced ecdysis sequence in the honeybee and beetle revealed considerable species-specific differences in pre-ecdysis and ecdysis behaviors. DNA sequences coding for putative ETHR were deduced from available genomes of several hemimetabolous and holometabolous insects. In all insects examined, the ethr gene encodes two subtypes of the receptor (ETHR-A and ETHR-B). Phylogenetic analysis showed that these receptors fall into a family of closely related GPCRs. We report for the first time the presence of putative ETHs and ETHRs in genomes of other arthropods, including the tick (Arachnida) and water flea (Crustacea). The possible source of ETH in ticks was detected in paired cells located in all pedal segments. Our results provide further evidence of structural and functional conservation of ETH-ETHR signaling. PMID:19951734

  7. Arthropod surveillance programs: Basic components, strategies, and analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effective entomological surveillance planning stresses a careful consideration of methodology, trapping technologies, and analysis techniques. Herein, the basic principles and technological components of arthropod surveillance plans are described, as promoted in the symposium “Advancements in arthro...

  8. Nuisance arthropods, nonhost odors, and vertebrate chemical aposematism

    NASA Astrophysics Data System (ADS)

    Weldon, Paul J.

    2010-05-01

    Mosquitoes, ticks, and other ectoparasitic arthropods use chemoreception to avoid vertebrates that are known or presumed to be dangerous or otherwise unprofitable hosts. Nonhosts may belong to a species that is regularly unaccepted or one that includes both accepted and unaccepted individuals. A diverse array of qualities including immunocompetence, vigilant grooming behavior, mechanical inaccessibility, and toxicity have been proposed as the features that render vertebrate chemical emitters unsuitable as hosts for arthropods. In addition to advantages accrued by ectoparasitic arthropods that avoid nonhosts, vertebrates that are not accepted as hosts benefit by evading injurious ectoparasites and the infectious agents they transmit. The conferral of advantages to both chemical receivers (ectoparasitic arthropods) and emitters (unpreferred vertebrates) in these interactions renders nonhost odors aposematic. Chemical aposematism involving ectoparasites selects for vertebrates that emit distinctive odors. In addition, chemical mimicry, where vulnerable organisms benefit when misidentified as nonhosts, may be accommodated by duped ectoparasites.

  9. Grandeur Alliances: Symbiont Metabolic Integration and Obligate Arthropod Hematophagy.

    PubMed

    Rio, Rita V M; Attardo, Geoffrey M; Weiss, Brian L

    2016-09-01

    Several arthropod taxa live exclusively on vertebrate blood. This food source lacks essential metabolites required for the maintenance of metabolic homeostasis, and as such, these arthropods have formed symbioses with nutrient-supplementing microbes that facilitate their host's 'hematophagous' feeding ecology. Herein we highlight metabolic contributions of bacterial symbionts that reside within tsetse flies, bed bugs, lice, reduviid bugs, and ticks, with specific emphasis on B vitamin and cofactor biosynthesis. Importantly, these arthropods can transmit pathogens of medical and veterinary relevance and/or cause infestations that induce psychological and dermatological distress. Microbial metabolites, and the biochemical pathways that generate them, can serve as specific targets of novel control mechanisms aimed at disrupting the metabolism of hematophagous arthropods, thus combatting pest invasion and vector-borne pathogen transmission. PMID:27236581

  10. Insecticide-induced hormesis and arthropod pest management.

    PubMed

    Guedes, Raul Narciso C; Cutler, G Christopher

    2014-05-01

    Ecological backlashes such as insecticide resistance, resurgence and secondary pest outbreaks are frequent problems associated with insecticide use against arthropod pest species. The last two have been particularly important in sparking interest in the phenomenon of insecticide-induced hormesis within entomology and acarology. Hormesis describes a biphasic dose-response relationship that is characterized by a reversal of response between low and high doses of a stressor (e.g. insecticides). Although the concept of insecticide-induced hormesis often does not receive sufficient attention, or has been subject to semantic confusion, it has been reported in many arthropod pest species and natural enemies, and has been linked to pest outbreaks and potential problems with insecticide resistance. The study of hormesis remains largely neglected in entomology and acarology. Here, we examined the concept of insecticide-induced hormesis in arthropods, its functional basis and potential fitness consequences, and its importance in arthropod pest management and other areas. PMID:24155227

  11. One-step PCR amplification of complete arthropod mitochondrial genomes.

    PubMed

    Hwang, U W; Park, C J; Yong, T S; Kim, W

    2001-06-01

    A new PCR primer set which enables one-step amplification of complete arthropod mitochondrial genomes was designed from two conserved 16S rDNA regions for the long PCR technique. For this purpose, partial 16S rDNAs amplified with universal primers 16SA and 16SB were newly sequenced from six representative arthropods: Armadillidium vulgare and Macrobrachium nipponense (Crustacea), Anopheles sinensis (Insecta), Lithobius forficatus and Megaphyllum sp. (Myriapoda), and Limulus polyphemus (Chelicerata). The genomic locations of two new primers, HPK16Saa and HPK16Sbb, correspond to positions 13314-13345 and 12951-12984, respectively, in the Drosophila yakuba mitochondrial genome. The usefulness of the primer set was experimentally examined and confirmed with five of the representative arthropods, except for A. vulgare, which has a linearized mitochondrial genome. With this set, therefore, we could easily and rapidly amplify complete mitochondrial genomes with small amounts of arthropod DNA. Although the primers suggested here were examined only with arthropod groups, a possibility of successful application to other invertebrates is very high, since the high degree of sequence conservation is shown on the primer sites in other invertebrates. Thus, this primer set can serve various research fields, such as molecular evolution, population genetics, and molecular phylogenetics based on DNA sequences, RFLP, and gene rearrangement of mitochondrial genomes in arthropods and other invertebrates. PMID:11399145

  12. Administering and Detecting Protein Marks on Arthropods for Dispersal Research.

    PubMed

    Hagler, James R; Machtley, Scott A

    2016-01-01

    Monitoring arthropod movement is often required to better understand associated population dynamics, dispersal patterns, host plant preferences, and other ecological interactions. Arthropods are usually tracked in nature by tagging them with a unique mark and then re-collecting them over time and space to determine their dispersal capabilities. In addition to actual physical tags, such as colored dust or paint, various types of proteins have proven very effective for marking arthropods for ecological research. Proteins can be administered internally and/or externally. The proteins can then be detected on recaptured arthropods with a protein-specific enzyme-linked immunosorbent assay (ELISA). Here we describe protocols for externally and internally tagging arthropods with protein. Two simple experimental examples are demonstrated: (1) an internal protein mark introduced to an insect by providing a protein-enriched diet and (2) an external protein mark topically applied to an insect using a medical nebulizer. We then relate a step-by-step guide of the sandwich and indirect ELISA methods used to detect protein marks on the insects. In this demonstration, various aspects of the acquisition and detection of protein markers on arthropods for mark-release-recapture, mark-capture, and self-mark-capture types of research are discussed, along with the various ways that the immunomarking procedure has been adapted to suit a wide variety of research objectives. PMID:26863574

  13. Antiviral responses of arthropod vectors: an update on recent advances.

    PubMed

    Rückert, Claudia; Bell-Sakyi, Lesley; Fazakerley, John K; Fragkoudis, Rennos

    2014-01-01

    Arthropod vectors, such as mosquitoes, ticks, biting midges and sand flies, transmit many viruses that can cause outbreaks of disease in humans and animals around the world. Arthropod vector species are invading new areas due to globalisation and environmental changes, and contact between exotic animal species, humans and arthropod vectors is increasing, bringing with it the regular emergence of new arboviruses. For future strategies to control arbovirus transmission, it is important to improve our understanding of virus-vector interactions. In the last decade knowledge of arthropod antiviral immunity has increased rapidly. RNAi has been proposed as the most important antiviral response in mosquitoes and it is likely to be the most important antiviral response in all arthropods. However, other newly-discovered antiviral strategies such as melanisation and the link between RNAi and the JAK/STAT pathway via the cytokine Vago have been characterised in the last few years. This review aims to summarise the most important and most recent advances made in arthropod antiviral immunity. PMID:25674592

  14. The incidence of bacterial endosymbionts in terrestrial arthropods

    PubMed Central

    Weinert, Lucy A.; Araujo-Jnr, Eli V.; Ahmed, Muhammad Z.; Welch, John J.

    2015-01-01

    Intracellular endosymbiotic bacteria are found in many terrestrial arthropods and have a profound influence on host biology. A basic question about these symbionts is why they infect the hosts that they do, but estimating symbiont incidence (the proportion of potential host species that are actually infected) is complicated by dynamic or low prevalence infections. We develop a maximum-likelihood approach to estimating incidence, and testing hypotheses about its variation. We apply our method to a database of screens for bacterial symbionts, containing more than 3600 distinct arthropod species and more than 150 000 individual arthropods. After accounting for sampling bias, we estimate that 52% (CIs: 48–57) of arthropod species are infected with Wolbachia, 24% (CIs: 20–42) with Rickettsia and 13% (CIs: 13–55) with Cardinium. We then show that these differences stem from the significantly reduced incidence of Rickettsia and Cardinium in most hexapod orders, which might be explained by evolutionary differences in the arthropod immune response. Finally, we test the prediction that symbiont incidence should be higher in speciose host clades. But while some groups do show a trend for more infection in species-rich families, the correlations are generally weak and inconsistent. These results argue against a major role for parasitic symbionts in driving arthropod diversification. PMID:25904667

  15. Numerical investigation of soil plugging effect inside sleeve of cast-in-place piles driven by vibratory hammers in clays.

    PubMed

    Xiao, Yong Jie; Chen, Fu Quan; Dong, Yi Zhi

    2016-01-01

    During driving sleeve of cast-in-place piles by vibratory hammers, soils were squeezed into sleeve and then soil plugging was formed. The physic-mechanical properties of the soil plug have direct influence on the load transmission between the sleeve wall and soil plug. Nevertheless, the researches on this issue are insufficient. In this study, finite element and infinite element coupling model was introduced, through the commercial code ABAQUS, to simulate the full penetration process of the sleeve driven from the ground surface to the desired depth by applying vibratory hammers. The research results indicated that the cyclic shearing action decreases both in soil shear strength and in granular cementation force when the sleeve is driven by vibratory hammers, which leads to a partially plugged mode of the soil plug inside the sleeve. Accordingly, the penetration resistance of sleeve driven by vibratory hammers is the smallest compared to those by other installation methods. When driving the sleeve, the annular soil arches forming in the soil plug at sleeve end induce a significant rise in the internal shaft resistance. Moreover, the influence of vibration frequencies, sleeve diameters, and soil layer properties on the soil plug was investigated in detail, and at the same time improved formulas were brought forward to describe the soil plug resistance inside vibratory driven sleeve. PMID:27386238

  16. Vibratory sources as compound stimuli for the octavolateralis systems: Dissection of specific stimulation channels using multiple behavioral approaches

    PubMed Central

    Braun, Christopher B.; Coombs, Sheryl

    2010-01-01

    An underwater vibratory source simultaneously presents acoustic and hydrodynamic disturbances. Because vibratory dipole sources are poor sonic projectors, most researchers have assumed that such sources are of greatest relevance to the lateral line system (LL). Both hydroacoustic principles and empirical studies have shown that vibratory dipole sources are also a potent stimulus to the inner ear of fishes. Responses to vibratory sources in mottled sculpin (Cottus bairdi) were assessed using unconditioned orienting, differential and non-differential-classical conditioning. Orienting responses are dominated by LL inputs and eliminated by LL pharmacological inactivation. Simple conditioning depends on inputs from other systems and was not affected by LL inactivation. Differential conditioning alters behavioral control, and sculpin could be conditioned to ignore substrate borne vibrations and respond only to hydroacoustic stimulation of the ear. The lateral line and inner ear of mottled sculpin do not necessarily exhibit range fractionation, as both systems operate over a similar distance from the animal (within 1.5 body lengths) and respond to many of the same sources. Vibratory dipole sources generate compound stimuli that simultaneously activate multiple octavolateralis systems, and animals make use of the channels differentially under different behavioral tasks. PMID:20384404

  17. Unilateral contact induced blade/casing vibratory interactions in impellers: Analysis for rigid casings

    NASA Astrophysics Data System (ADS)

    Batailly, Alain; Meingast, Markus; Legrand, Mathias

    2015-02-01

    This contribution addresses the vibratory analysis of unilateral-contact induced structural interactions between a bladed impeller and its surrounding rigid casing. Such assemblies can be found in helicopter or small aircraft engines for instance and the interactions of interest shall arise due to the always tighter operating clearances between the rotating and stationary components. The investigation is conducted by extending to cyclically symmetric structures an in-house time-marching based tool dedicated to unilateral contact occurrences in turbomachines. The main components of the considered impeller together with the associated assumptions and modelling principles considered in this work are detailed. Typical dynamical features of cyclically symmetric structures, such as the aliasing effect and frequency clustering are explored in this nonlinear framework by means of thorough frequency-domain analyses and harmonic trackings of the numerically predicted impeller displacements. Additional contact maps highlight the existence of critical rotational velocities at which displacements potentially reach high amplitudes due to the synchronization of the bladed assembly vibratory pattern with the shape of the rigid casing. The proposed numerical investigations are also compared to a simpler and (almost) empirical criterion: it is suggested, based on nonlinear numerical simulations with a linear reduced order model of the impeller and a rigid casing, that this criterion may miss important critical velocities emanating from the unfavorable combination of aliasing and contact-induced higher harmonics in the vibratory response of the impeller. Overall, this work suggests a way to enhance guidelines to improve the design of impellers in the context of nonlinear and nonsmooth dynamics.

  18. Microspectrophotometry of arthropod visual screening pigments.

    PubMed

    Strother, G K; Casella, A J

    1972-05-01

    Absorption spectra of visual screening pigments obtained in vitro with a microspectrophotometer using frozen sections are given for the insects Musca domestica, Phormia regina, Libellula luctuosa, Apis mellifera (worker honeybee only), Drosophila melanogaster (wild type only) and the arachnids Lycosa baltimoriana and Lycosa miami. The spectral range covered is 260-700 nm for Lycosa and Drosophila and 310-700 nm for the remainder of the arthropods. A complete description of the instrumentation is given. For the flies, Phormia and Musca, light absorption by the yellow and red pigments is high from 310 to about 610 nm. This implies that for these insects there should be no wavelength shift in electroretinogram (ERG) results due to light leakage among neighboring ommatidia for this wavelength range. The same comment applies to Calliphora erythrocephala, which is known to have similar screening pigments. For some of the insects studied a close correspondence is noted between screening pigment absorption spectra and spectral sensitivity curves for individual photoreceptors, available in the literature. In some cases the screening pigment absorption spectra can be related to chemical extraction results, with the general observation that some of the in vitro absorption peaks are shifted to the red. The Lycosa, Apis, and Libellula dark red pigments absorb strongly over a wide spectral range and therefore prevent chemical identification. PMID:4623852

  19. Process for forming integral edge seals in porous gas distribution plates utilizing a vibratory means

    NASA Technical Reports Server (NTRS)

    Feigenbaum, Haim (Inventor); Pudick, Sheldon (Inventor)

    1988-01-01

    A process for forming an integral edge seal in a gas distribution plate for use in a fuel cell. A seal layer is formed along an edge of a porous gas distribution plate by impregnating the pores in the layer with a material adapted to provide a seal which is operative dry or when wetted by an electrolyte of a fuel cell. Vibratory energy is supplied to the sealing material during the step of impregnating the pores to provide a more uniform seal throughout the cross section of the plate.

  20. Analysis of compensation for a g-sensitivity scale-factor error for a MEMS vibratory gyroscope

    NASA Astrophysics Data System (ADS)

    Park, Byung Su; Han, KyungJun; Lee, SangWoo; Yu, MyeongJong

    2015-11-01

    In this paper, we present recent work on the g-sensitivity error of the MEMS vibratory gyroscope. Generally, the g-sensitivity error has been ignored in the use of commercial MEMS vibratory gyroscopes, but it deserves our attention if we are to achieve tactical grade performance for military applications. First, we mathematically show the reason the g-sensitivity error occurs as an additional scale-factor error during the use of MEMS vibratory gyroscopes. Then, we estimate the g-sensitivity error using FEM simulation and verify it by experiment using a centrifugal machine. Consequently, we propose a compensation model to accommodate the g-sensitivity error of a gyroscope and confirm the theoretical prediction with experimental results.

  1. Investigation on Multi-Physics Simulation-Based Virtual Machining System for Vibratory Finishing of Integrally Bladed Rotors (IBRS)

    NASA Astrophysics Data System (ADS)

    Achiamah-Ampomah, N.; Cheng, Kai

    2016-02-01

    An investigation was carried out to improve the slow surface finishing times of integrally bladed rotors (IBRs) in the aerospace industry. Traditionally they are finished by hand, or more currently by abrasive flow machining. The use of a vibratory finishing technique to improve process times has been suggested; however as a largely empirical process, very few studies have been done to improve and optimize the cycle times, showing that critical and ongoing research is still needed in this area. An extensive review of the literature was carried out, and the findings used to identify the key parameters and model equations which govern the vibratory process. Recommendations were made towards a multi-physics-based simulation model, as well as projections made for the future of vibratory finishing and optimization of surface finishes and cycle times.

  2. Arthropod community structure on strip-mined lands in Ohio

    SciTech Connect

    Urbanek, R.P.

    1982-01-01

    During 1978-79, biomass, density, diversity, and taxonomic composition of above-ground, non-acarine arthropods were studied on newly reclaimed areas planted to grass-legumes (1-4 years after reclamation), older mined lands planted to crown vetch (Coronilla varia L.) and unmined old field habitat in Harrison County, Ohio. The reclaimed areas were rapidly colonized and productive. In the herbaceous layer, newly reclaimed areas had highest annual arthropod densities (1062.5 individuals/m/sup 2/) and biomass (553.6 mg/m/sup 2/). Larvae of alfalfa weevil (Hypera postica Gyllenhal) were major contributors to arthropod density in the herbaceous layer during spring 1978, accounting for 47.4% and 18.8% of individuals on the areas examined 1 and 3 years after reclamation, respectively. During September, grasshoppers (Acrididae) accounted for up to 70% of arthropod biomass in the herbaceous layer on newly reclaimed areas. A significant decline in arthropod biomass from 1 to 2 years after reclamation was due to a large decrease in weevil and spittlebug (Philaenus spumarius L.) populations, associated with a decline in yellow sweet clover (Melilotus officinalis (L.) Lam.) and red clover (Trifolium pratense L.). The crown vetch area supported low numbers and biomass of arthropods in the herbaceous layer but moderate to high numbers and biomass in the litter layer. Nematoceran larvae (Cecidomyiidae, Chironomidae) were abundant during May on the area examined 2 years after reclamation and comprised 73.5% of litter arthropod individuals. The unmined old field was generally richer (48.0% more morphotypes, 32.2% more families per sampling period) than the mined sites. On newly reclaimed areas richness in the herbaceous layer was positively related to biomass of clovers.

  3. [Protection of travellers against biting arthropod vectors].

    PubMed

    Carnevale, P

    1998-01-01

    Several diseases are transmitted by hematophageous insect/arthropod and, except for yellow fever and Japanese B encephalitis, there are still no vaccines. Personal protection therefore remains the choice method for disease prevention and can usefully complete chemoprophylaxis if available (such as for malaria). Personal protection can be ensured by three main methods: avoiding risky areas; using repellents on skin and/or garments; using pyrethroids insecticide on garments (permethrin), mosquito nets (several Pyr. available) and any other materials (curtains etc.) including camping tents, plasting "UN sheeting" used in refugees camps etc. Repellent gave some protection for few hours (# 6 hours) and new formulations have been developed to extend their duration. Great care must be taken when using DEET which is not recommended for children and pregnant women. Coils and mats can be used but care must also be taken when using some coils available on local market and which can often be irritating and useless. Mosquito nets impregnated with an insecticide remains the choice method of protection against night-biting insects such as anopheles and is a good way of preventing malaria. Insecticide must be used according to safety measures clearly indicated (or which must be clearly indicated) by companies. All these measures are efficient and must be selected according to local conditions and human behaviour. Travelling is not "risky" but 3 points must be kept in mind: accurate advice must be sought before travelling; this advice must be followed while persuing a "normal life"; a physician must be consulted in case of any trouble during and after the trip. PMID:10078390

  4. An Overview of A Perturbation Analysis for Uni-directionally Coupled Vibratory Gyroscopes

    NASA Astrophysics Data System (ADS)

    Vu, Huy; Palacios, Antonio; In, Visarath; Longhini, Patrick; Neff, Joseph

    2011-04-01

    The complex behaviours of gyroscope systems have been scientifically researched and thoroughly studied for decades. Most of scientific research involving gyroscopes specifically concentrates on studying the designs and fabrications at the circuitry level. Although gaining a recent popularity with the low cost of MEMS device that offers an attractive approach for gyroscope fabrications, its performance is far from meeting the requirements for an inertial grade guidance system. To improve the performance, our current research is theoretically focusing upon investigating the dynamics of vibratory gyroscopes coupled in a ring configuration. Particularly, a certain topology of arrangements among coupled gyroscopes can be designed and studied to enhance robustness. The main operation depends mostly on an external source for a stable oscillation in the drive axis, while an oscillatory motion in the sense axis, which is used to detect an angular rate of rotation, is enabled through the transfers of energy from the drive via the Coriolis force. With the mathematical model depicted as Duffing oscillators, however, by adding a certain coupling among gyroscopes, a similar behavior to a Duffing oscillator is expected, only with more complicated dynamics at a higher dimension. A number of Perturbation methods have popularly been carried out, to seek for a general asymptotic solution of typical Duffing oscillators. In this work as an overview, the two-time scale Perturbation expansion is asymptotically applied on the uni-directionally coupled vibratory gyroscopes to find an analytical solution which is then compared to the numerical one.

  5. Structural-Acoustic Coupling Effects on the Non-Vacuum Packaging Vibratory Cylinder Gyroscope

    PubMed Central

    Xi, Xiang; Wu, Xuezhong; Wu, Yulie; Zhang, Yongmeng; Tao, Yi; Zheng, Yu; Xiao, Dingbang

    2013-01-01

    The resonant shells of vibratory cylinder gyroscopes are commonly packaged in metallic caps. In order to lower the production cost, a portion of vibratory cylinder gyroscopes do not employ vacuum packaging. However, under non-vacuum packaging conditions there can be internal acoustic noise leading to considerable acoustic pressure which is exerted on the resonant shell. Based on the theory of the structural-acoustic coupling, the dynamical behavior of the resonant shell under acoustic pressure is presented in this paper. A finite element (FE) model is introduced to quantitatively analyze the effect of the structural-acoustic coupling. Several main factors, such as sealing cap sizes and degree of vacuum which directly affect the vibration of the resonant shell, are studied. The results indicate that the vibration amplitude and the operating frequency of the resonant shell will be changed when the effect of structural-acoustic coupling is taken into account. In addition, an experiment was set up to study the effect of structural-acoustic coupling on the sensitivity of the gyroscope. A 32.4 mV/°/s increase of the scale factor and a 6.2 Hz variation of the operating frequency were observed when the radial gap size between the resonant shell and the sealing cap was changed from 0.5 mm to 20 mm. PMID:24351631

  6. Making and suspension capabilities of vibratory agitators in a slab tank

    SciTech Connect

    Ramsey, C.J.; Kyser, E.A. III; Tatterson, G.B.

    1988-12-31

    Seven different vibratory agitators, consisting of single and dual flat blade configurations or dual angle blade configurations, were studied for their ability to produce mixing and solid suspension in a slab tank. The mixing behavior of the various configurations was recorded on video tape, and mixing times were measured as the time needed to disperse injected dye. The solid suspension tests, using ash tray sand, were conducted to determine the minimum stroke frequency of the agitators needed for complete off-bottom suspension. The mixing studies demonstrated that vibratory agitation produced strong vertical fluid motion, good bulk circulation and dispersion in the liquid. The effects of stroke frequency, n; amplitude, a; blade width, w; blade clearance, c; and liquid depth, h, on mixing time, {theta}, were studied. Single blade geometries produced complete mixing in the least number of strokes. The most effective geometry, in terms of both mixing and solid suspension, was a single flat blade with minimum off-bottom clearance and a blade width/tank thickness ratio, w/T, of 0.74 at the maximum stroke amplitude of 51 mm.

  7. Effect On The Processing Characteristics Of ZnO Varistors Produced Using Vibratory Milling

    NASA Astrophysics Data System (ADS)

    Kelleher, M. C.; Hashmi, M. S. J.

    2011-01-01

    Each manufacturing stage in the production of zinc oxide varistors from powder preparation to the final encapsulated device is important not only for the formation of the varistor component with optimum microstructure and thus electrical characteristics but also for avoiding the introduction of flaws and reduced yield. In this paper the authors describe and discuss the effect of multi-elemental oxide additives having been milled for different durations using a vibratory mill with cylindrical zirconia media on the powder characteristics of the subsequent processing stages. A commercial ZnO varistor formulation was used. The subsequent processing stages that are given particular attention include first spray drying and second milling. The characteristics include agglomerate size, powder density and elemental uniformity of the first spray-dried powders, and particle size, specific surface area, zirconium concentration and pore size of the second milled powders. They were evaluated using laser diffraction, scanning electron microscopic, mercury porosimetry, Brunauer, Emmett and Teller (BET) and inductively coupled plasma (ICP) analysis. Some interesting correlations are observed between the powder properties and vibratory milling durations of the mixed metal oxide additives (MMOA).

  8. A Study of the Temperature Characteristics of Vibration Mode Axes for Vibratory Cylinder Gyroscopes

    PubMed Central

    Wu, Yulie; Xi, Xiang; Tao, Yi; Wu, Xiaomei; Wu, Xuezhong

    2011-01-01

    The zero bias stability, which is an important performance parameter for vibratory cylinder gyroscopes, is high sensitive to temperature change. It is considered that the varying temperature makes the vibration mode axes unstable, which has significant influence on the zero bias stability. This paper will investigate this problem in detail. First, the relationships between the angular positions of vibration mode axes and the zero bias are analyzed. Secondly, the thermal-modal model of the cylinder resonator with several defects such as mass imbalance, frequency split (FS), and geometry errors are developed by ANSYS. Simulation results show that with the increase of temperature, angular positions of the vibration mode axes obviously change, which leads to a dramatic zero bias drift. Finally, several major influence factors on the angular position stability of vibration mode axes, including frequency split, geometry errors, thermal elastic modulus coefficient (TEMC) and thermal expansion coefficient (TEC) are analyzed in detail. Simulation results in this paper will be helpful for deep understanding of the drift principle of zero bias induced by temperature for vibratory cylinder gyroscopes and also be helpful for further temperature compensation or control. PMID:22164038

  9. Vibratory Gyro-Sensor Using Vertically Set Quartz Crystal Trident-Type Tuning Fork Resonator

    NASA Astrophysics Data System (ADS)

    Shiratori, Norihiko; YoshiroTomikawa, YoshiroTomikawa; Ohnishi, Kazumasa

    1999-05-01

    In this study we deal with a new type of vibratory gyro-sensor using a vertically set quartz crystal trident-type tuning fork resonator. The sensor is made of X-cut quartz crystal wafer formed by rotating 2° about the X-axis, applying the wire saw cutting method. The slits that form three arms are cut along the Y-axis direction. In such a trident-type tuning fork resonator, two resonance vibration modes are used: one has vibrational displacement in the vertical direction (X-axis) of the tuning fork plane and the other has that in the horizontal direction (Z‧-axis). When an angular rate (ΩY‧) around the Y‧-axis is applied to the trident-type tuning fork gyro-sensor vibrating in the V-MODE, Coriolis forces, due to the ΩY‧, are applied on the three arms in the X‧-axis direction and the H-MODE vibration is induced. Therefore, the angular rate (ΩY‧) can be determined by detecting the signals of H-MODE vibration. The experimental results have proved that the vibratory gyro-sensor that uses such a quartz crystal tuning fork resonator has good characteristics.

  10. Conjectural bifurcation analysis of the contact-induced vibratory response of an aircraft engine blade

    NASA Astrophysics Data System (ADS)

    Batailly, Alain; Legrand, Mathias; Millecamps, Antoine; Garcin, François

    2015-07-01

    This paper deals with the numerical investigation of the unilateral contact-induced dynamics of a turbomachine blade rotating within a perfectly rigid yet distorted casing. This investigation is motivated by unelucidated vibratory behaviours observed experimentally. The simulations are based on an in-house time-marching strategy incorporating Lagrange multipliers for the unilateral contact treatment, as well as centrifugal stiffening and abradable coating removal. Significant extensions are proposed through the implementation of (1) aerodynamic loading on the blade and (2) post-processing techniques involving the empirical mode decomposition which provides fruitful insights on important transient phenomena. A thorough bifurcation analysis with and without aerodynamic loading highlights the existence of flip bifurcations with period-doubling and period-halving sequences over a broad angular speed range. Numerical simulations with external aerodynamic loading yield quasi-periodic and likely to be chaotic motions that could not be observed under vacuum. The proposed numerical investigations underline the key role of the aerodynamic loading in the blade dynamics and suggest that unexplained experimental vibratory behaviours are related to the vacuum conditions of the experiment.

  11. Vibratory noise to the fingertip enhances balance improvement associated with light touch.

    PubMed

    Magalhães, Fernando Henrique; Kohn, André Fabio

    2011-03-01

    Light touch of a fingertip on an external stable surface greatly improves the postural stability of standing subjects. The hypothesis of the present work was that a vibrating surface could increase the effectiveness of fingertip signaling to the central nervous system (e.g., by a stochastic resonance mechanism) and hence improve postural stability beyond that achieved by light touch. Subjects stood quietly over a force plate while touching with their right index fingertip a surface that could be either quiescent or randomly vibrated at two low-level noise intensities. The vibratory noise of the contact surface caused a significant decrease in postural sway, as assessed by center of pressure measures in both time and frequency domains. Complementary experiments were designed to test whether postural control improvements were associated with a stochastic resonance mechanism or whether attentional mechanisms could be contributing. A full curve relating body sway parameters and different levels of vibratory noise resulted in a U-like function, suggesting that the improvement in sway relied on a stochastic resonance mechanism. Additionally, no decrease in postural sway was observed when the vibrating contact surface was attached to the subject's body, suggesting that no attentional mechanisms were involved. These results indicate that sensory cues obtained from the fingertip need not necessarily be associated with static contact surfaces to cause improvement in postural stability. A low-level noisy vibration applied to the contact surface could lead to a better performance of the postural control system. PMID:21191573

  12. The hand and environment (3)--physiological changes of digital functions in two age groups studied by vibratory stimulations and a cold water immersion.

    PubMed

    Suzuki, K; Ijichi, M; Kobayashi, Y; Matsuki, T; Ito, K; Kamogawa, M; Matsushita, T; Kotani, K; Seki, A; Tanaka, H; Kawamura, K

    1982-02-25

    Skin temperature, vibratory sensibility and pinch strength of the hand were recorded continuously in 20 healthy adults through two vibratory stress tests (32 Hz and 125 Hz) and a cold water (10 degrees C) immersion (for 10 min) test in a climatic chamber (20 degrees C, 50% humidity). As a stressor to the hand, the immersion was the most effective and the vibrator stress at 32 Hz was next. As a detector for function of the hand, vibratory sensibility at 125 Hz was proved to be the most valuable and the digital temperature was the next. As to aging, the mature age group showed low vibratory sensibilities at 63 Hz, higher digital temperatures, stronger pinch strengths, and quicker recoveries after the stress tests. Along the passage of time after entering the chamber, the vibratory sensibilities and the pinch strengths did not show any changes. However, the digital temperatures became continuously lower. PMID:7077112

  13. Skimming the surface with Burgess Shale arthropod locomotion

    PubMed Central

    Minter, Nicholas J.; Mángano, M. Gabriela; Caron, Jean-Bernard

    2012-01-01

    The first arthropod trackways are described from the Middle Cambrian Burgess Shale Formation of Canada. Trace fossils, including trackways, provide a rich source of biological and ecological information, including direct evidence of behaviour not commonly available from body fossils alone. The discovery of large arthropod trackways is unique for Burgess Shale-type deposits. Trackway dimensions and the requisite number of limbs are matched with the body plan of a tegopeltid arthropod. Tegopelte, one of the rarest Burgess Shale animals, is over twice the size of all other benthic arthropods known from this locality, and only its sister taxon, Saperion, from the Lower Cambrian Chengjiang biota of China, approaches a similar size. Biomechanical trackway analysis demonstrates that tegopeltids were capable of rapidly skimming across the seafloor and, in conjunction with the identification of gut diverticulae in Tegopelte, supports previous hypotheses on the locomotory capabilities and carnivorous mode of life of such arthropods. The trackways occur in the oldest part (Kicking Horse Shale Member) of the Burgess Shale Formation, which is also known for its scarce assemblage of soft-bodied organisms, and indicate at least intermittent oxygenated bottom waters and low sedimentation rates. PMID:22072605

  14. Exoskeletons and economics: indoor arthropod diversity increases in affluent neighbourhoods.

    PubMed

    Leong, Misha; Bertone, Matthew A; Bayless, Keith M; Dunn, Robert R; Trautwein, Michelle D

    2016-08-01

    In urban ecosystems, socioeconomics contribute to patterns of biodiversity. The 'luxury effect', in which wealthier neighbourhoods are more biologically diverse, has been observed for plants, birds, bats and lizards. Here, we used data from a survey of indoor arthropod diversity (defined throughout as family-level richness) from 50 urban houses and found that house size, surrounding vegetation, as well as mean neighbourhood income best predict the number of kinds of arthropods found indoors. Our finding, that homes in wealthier neighbourhoods host higher indoor arthropod diversity (consisting of primarily non-pest species), shows that the luxury effect can extend to the indoor environment. The effect of mean neighbourhood income on indoor arthropod diversity was particularly strong for individual houses that lacked high surrounding vegetation ground cover, suggesting that neighbourhood dynamics can compensate for local choices of homeowners. Our work suggests that the management of neighbourhoods and cities can have effects on biodiversity that can extend from trees and birds all the way to the arthropod life in bedrooms and basements. PMID:27484644

  15. The non-target impact of spinosyns on beneficial arthropods.

    PubMed

    Biondi, Antonio; Mommaerts, Veerle; Smagghe, Guy; Viñuela, Elisa; Zappalà, Lucia; Desneux, Nicolas

    2012-12-01

    Spinosyn-based products, mostly spinosad, have been widely recommended by extension specialists and agribusiness companies; consequently, they have been used to control various pests in many different cropping systems. Following the worldwide adoption of spinosad-based products for integrated and organic farming, an increasing number of ecotoxicological studies have been published in the past 10 years. These studies are primarily related to the risk assessment of spinosad towards beneficial arthropods. This review takes into account recent data with the aim of (i) highlighting potentially adverse effects of spinosyns on beneficial arthropods (and hence on ecosystem services that they provide in agroecosystems), (ii) clarifying the range of methods used to address spinosyn side effects on biocontrol agents and pollinators in order to provide new insights for the development of more accurate bioassays, (iii) identifying pitfalls when analysing laboratory results to assess field risks and (iv) gaining increasing knowledge on side effects when using spinosad for integrated pest management (IPM) programmes and organic farming. For the first time, a thorough review of possible risks of spinosad and novel spinosyns (such as spinetoram) to beneficial arthropods (notably natural enemies and pollinators) is provided. The acute lethal effect and multiple sublethal effects have been identified in almost all arthropod groups studied. This review will help to optimise the future use of spinosad and new spinosyns in IPM programmes and for organic farming, notably by preventing the possible side effects of spinosyns on beneficial arthropods. PMID:23109262

  16. The organic preservation of fossil arthropods: an experimental study

    PubMed Central

    Gupta, Neal S; Michels, R; Briggs, Derek E.G; Evershed, Richard P; Pancost, Richard D

    2006-01-01

    Modern arthropod cuticles consist of chitin fibres in a protein matrix, but those of fossil arthropods with an organic exoskeleton, particularly older than Tertiary, contain a dominant aliphatic component. This apparent contradiction was examined by subjecting modern cockroach, scorpion and shrimp cuticle to artificial maturation (350 °C/700 bars/24 h) following various chemical treatments, and analysing the products with pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS). Analysis of artificially matured untreated cuticle yielded moieties related to phenols and alkylated substituents, pyridines, pyrroles and possibly indenes (derived from chitin). n-Alkyl amides, C16 and C18 fatty acids and alkane/alk-1-ene homologues ranging from C9 to C19 were also generated, the last indicating the presence of an n-alkyl component, similar in composition to that encountered in fossil arthropods. Similar pyrolysates were obtained from matured pure C16 and C18 fatty acids. Py–GC/MS of cuticles matured after lipid extraction and hydrolysis did not yield any aliphatic polymer. This provides direct experimental evidence that lipids incorporated from the cuticle were the source of aliphatic polymer. This process of in situ polymerization appears to account for most of the fossil record of terrestrial arthropods as well as marine arthropods that lacked a biomineralized exoskeleton. PMID:17015325

  17. Arthropods and their products as aphrodisiacs--review of literature.

    PubMed

    Pajovic, B; Radosavljevic, M; Radunovic, M; Radojevic, N; Bjelogrlic, B

    2012-04-01

    After a short review of impotence, the definitions of erectants and aphrodisiacs are presented. The Authors propose division of arthropods according to the places of effect. The description of particular arthropods with their pictures and nomenclature, is followed by certain or probable mechanisms of achieving the aphrodisiac and sometimes toxic effect, that were available in the literature since 1929 till nowadays. We mention the most usual locations, mainly in Asia, where they are found and consumed, but also, we describe the manner of preparing and intake. The review includes the following arthropods: lobster, Arizona bark scorpion, deathstalker, banana spider, Mediterranean black widow, Burmeister's triatoma, giant water bug, diving-beetle, Korean bug, diaclina, flannel moth, Spanish fly, migratory locust, red wood ant and honeybee. PMID:22696884

  18. Species identity influences belowground arthropod assemblages via functional traits

    PubMed Central

    Gorman, Courtney E.; Read, Quentin D.; Van Nuland, Michael E.; Bryant, Jessica A. M.; Welch, Jessica N.; Altobelli, Joseph T.; Douglas, Morgan J.; Genung, Mark A.; Haag, Elliot N.; Jones, Devin N.; Long, Hannah E.; Wilburn, Adam D.; Schweitzer, Jennifer A.; Bailey, Joseph K.

    2013-01-01

    Plant species influence belowground communities in a variety of ways, ultimately impacting nutrient cycling. Functional plant traits provide a means whereby species identity can influence belowground community interactions, but little work has examined whether species identity influences belowground community processes when correcting for evolutionary history. Specifically, we hypothesized that closely related species would exhibit (i) more similar leaf and root functional traits than more distantly related species, and (ii) more similar associated soil arthropod communities. We found that after correcting for evolutionary history, tree species identity influenced belowground arthropod communities through plant functional traits. These data suggest that plant species structure may be an important predictor in shaping associated soil arthropod communities and further suggest the importance of better understanding the extended consequences of evolutionary history on ecological processes, as similarity in traits may not always reflect similar ecology.

  19. Inbreeding and the evolution of sociality in arthropods

    NASA Astrophysics Data System (ADS)

    Tabadkani, Seyed Mohammad; Nozari, Jamasb; Lihoreau, Mathieu

    2012-10-01

    Animals have evolved strategies to optimally balance costs and benefits of inbreeding. In social species, these adaptations can have a considerable impact on the structure, the organization, and the functioning of groups. Here, we consider how selection for inbreeding avoidance fashions the social behavior of arthropods, a phylum exhibiting an unparalleled richness of social lifestyles. We first examine life histories and parental investment patterns determining whether individuals should actively avoid or prefer inbreeding. Next, we illustrate the diversity of inbreeding avoidance mechanisms in arthropods, from the dispersal of individuals to the rejection of kin during mate choice and the production of unisexual broods by females. Then, we address the particular case of haplodiploid insects. Finally, we discuss how inbreeding may drive and shape the evolution of arthropods societies along two theoretical pathways.

  20. Molecular bases of proliferation of Francisella tularensis in Arthropod vectors

    PubMed Central

    Asare, Rexford; Akimana, Christine; Jones, Snake; Kwaik, Yousef Abu

    2010-01-01

    Summary Arthropod vectors are important vehicles for transmission of Francisella tularensis between mammals, but very little is known about the F. tularensis-arthropod vector interaction. Drosophila melanogaster has been recently developed as an arthropod vector model for F. tularensis. We have shown that intracellular trafficking of F. tularensis within human monocytes-derived macrophages and D. melanogaster-derived S2 cells is very similar. Within both evolutionarily distant host cells, the Francisella-containing phagosome matures to a late endosome-like phagosome with limited fusion to lysosomes followed by rapid bacterial escape into the cytosol where the bacterial proliferate. To decipher the molecular bases of intracellular proliferation of F. tularensis within arthropod-derived cells, we screened a comprehensive library of mutants of F. tularensis subsp novicida for their defect in intracellular proliferation within D. melanogaster-derived S2 cells. Our data show that 394 genes, representing 22% of the genome, are required for intracellular proliferation within D. melanogaster-derived S2 cells, including many of the Francisella Pathogenicity Island (FPI) genes that are also required for proliferation within mammalian macrophages. Functional gene classes that exhibit growth defect include metabolic (25%), FPI (2%), Type IV pili (1%), transport (16%) and DNA modification (5%). Among 168 most defective mutants in intracellular proliferation in S2 cells, 80 are defective in lethality and proliferation within adult D. melanogaster. The observation that only 135 of the 394 mutants that are defective in S2 cells are also defective in human macrophages indicates that F. tularensis utilize common as well as distinct mechanisms to proliferate within mammalian and arthropod cells. Our studies will facilitate deciphering the molecular aspects of F. tularensis-arthropod vector interaction and its patho-adaptation to infect mammals. PMID:20482589

  1. Vibratory sources as compound stimuli for the octavolateralis systems: dissection of specific stimulation channels using multiple behavioral approaches.

    PubMed

    Braun, Christopher B; Coombs, Sheryl

    2010-04-01

    Underwater vibratory sources simultaneously present acoustic and hydrodynamic disturbances. Because vibratory dipole sources are poor sonic projectors, most researchers have assumed that such sources are of greatest relevance to the lateral line system. Both hydroacoustic principles and empirical studies have shown that dipole sources are also a potent stimulus to the inner ear. Responses to vibratory sources in mottled sculpin (Cottus bairdi) were assessed using unconditioned orienting, differential and nondifferential conditioning. Orienting responses are dominated by lateral line inputs and eliminated by lateral line inactivation. Simple conditioning depends on inputs from other systems and was not affected by lateral line inactivation. Differential conditioning alters behavioral control, and sculpin could be conditioned to ignore substrate-borne vibrations and respond only to hydroacoustic stimulation of the ear. The lateral line and inner ear of mottled sculpin do not necessarily exhibit range fractionation, as both systems operate over a similar distance (within 1.5 body lengths) and respond to many of the same sources. Vibratory dipole sources generate compound stimuli that simultaneously activate multiple octavolateralis systems, and sculpin make use of the channels differentially under different behavioral tasks. PMID:20384404

  2. [2013 update about arthropod envenomations in French Guyana].

    PubMed

    Ganteaume, F; Imbert, C

    2014-02-01

    French Guiana, by its geographical situation, its climate and its biodiversity, is often called "the green hell". Indeed, this French department of America shelters a wildlife rich, abundant among which many species of arthropods, some of which are responsible for envenomations. These accidents consist of scorpion's or hymenoptera's stings or spider's bites. The associated clinical aspect is variable, from simple pain to circulatory collapse, or lung oedema. However, symptomatology is generally mild; four deaths associated to arthropod envenomations have been reported in the past 25 years. This article focuses on envenomations in French Guiana, describing favoring human behavior, risks and venoms associated with the main related animal species. PMID:24415535

  3. The endoskeletal structures in arthropods: cytology, morphology and evolution.

    PubMed

    Bitsch, Colette; Bitsch, Jacques

    2002-02-01

    The paper proposes an overview of the endoskeletal structures of the head and trunk in the different arthropod groups: Chelicerata, Crustacea, Myriapoda and Hexapoda (=Insecta s.l.). Two major endoskeletal systems are reported with their cytological characteristics: those made up of connective tissue derived from muscular tendons, and those consisting of cuticular rods or plates arising from integumentary ingrowths. The morphological value of the various endoskeletal structures, their possible homologies in different groups, and their presumed evolutionary changes are discussed. This survey may be considered as a first step to use morphological characteristics of the endoskeleton in future cladistic analyses to assess the phylogeny of arthropods. PMID:18088953

  4. 40 CFR 180.1124 - Arthropod pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Arthropod pheromones; exemption from... FOOD Exemptions From Tolerances § 180.1124 Arthropod pheromones; exemption from the requirement of a tolerance. Arthropod pheromones, as described in § 152.25(b) of this chapter, when used in retrievably...

  5. 40 CFR 180.1124 - Arthropod pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Arthropod pheromones; exemption from... FOOD Exemptions From Tolerances § 180.1124 Arthropod pheromones; exemption from the requirement of a tolerance. Arthropod pheromones, as described in § 152.25(b) of this chapter, when used in retrievably...

  6. 40 CFR 180.1124 - Arthropod pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Arthropod pheromones; exemption from... FOOD Exemptions From Tolerances § 180.1124 Arthropod pheromones; exemption from the requirement of a tolerance. Arthropod pheromones, as described in § 152.25(b) of this chapter, when used in retrievably...

  7. 40 CFR 180.1124 - Arthropod pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Arthropod pheromones; exemption from... FOOD Exemptions From Tolerances § 180.1124 Arthropod pheromones; exemption from the requirement of a tolerance. Arthropod pheromones, as described in § 152.25(b) of this chapter, when used in retrievably...

  8. 40 CFR 180.1124 - Arthropod pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Arthropod pheromones; exemption from... FOOD Exemptions From Tolerances § 180.1124 Arthropod pheromones; exemption from the requirement of a tolerance. Arthropod pheromones, as described in § 152.25(b) of this chapter, when used in retrievably...

  9. Effect of residual stress on modal patterns of MEMS vibratory gyroscope

    NASA Astrophysics Data System (ADS)

    Dutta, Shankar; Panchal, Abha; Kumar, Manoj; Pal, Ramjay; Bhan, R. K.

    2016-04-01

    Deep boron diffusion often induces residual stress in bulk micromachined MEMS structures, which may affect the MEMS devices operation. In this study, we studied the modal patterns of MEMS vibratory gyroscope under the residual stress (100 - 1000 MPa). Modal patterns and modal frequencies of the gyro are found to be dependent on the residual stress values. Without any residual stress, the modal frequencies drive and sense modeswere found to be 20.06 kHz and 20.36 kHz respectively. In presence of 450 MPa residual stress, the modal frequencies of the drive and sense modes were changed to 42.75 kHz and 43.07 kHz respectively.

  10. Understanding the role of nonlinearities in the transduction of vibratory energy harvesters

    NASA Astrophysics Data System (ADS)

    Masana, Ravindra Shiva Charan

    The last two decades have witnessed several advances in micro-fabrication technologies and electronics, leading to the development of small, low-power devices for wireless sensing, data transmission, actuation, and medical implants. Unfortunately, the actual implementation of such devices in their respective environment has been hindered by the lack of scalable energy sources that are necessary to power and maintain them. Batteries, which remain the most commonly used power source, have not kept pace with the demands of these devices, especially in terms of energy density. In light of this challenge, the concept of vibratory energy harvesting has flourished in recent years as a possible alternative to power and maintain low-power electronics. While linear vibratory energy harvesters have received the majority of the literature's attention, a significant body of the current research activity is focused on the concept of purposeful inclusion of nonlinearities for broadband transduction. When compared to their linear resonant counterparts, nonlinear energy harvesters have a wider steady-state frequency bandwidth, leading to the common belief that they can be utilized to improve performance especially in random and non-stationary vibratory environments. This dissertation aims to critically investigate this belief by drawing a clearer picture of the role of nonlinearities in the transduction of energy harvesters and by defining the conditions under which nonlinearities can be used to enhance performance. To achieve this goal, the Thesis is divided into three parts. The first part investigates the performance of mono- and bi-stable energy harvesters under harmonic excitations and carries a detailed analysis of their relative performance. The second part investigates their response to broadband and narrowband random excitations and again analyzes their relative behavior. The third part exploits the super-harmonic resonance bands of bi-stable energy harvesters for the

  11. Accuracy of micro powder dosing via a vibratory sieve-chute system.

    PubMed

    Besenhard, M O; Faulhammer, E; Fathollahi, S; Reif, G; Calzolari, V; Biserni, S; Ferrari, A; Lawrence, S M; Llusa, M; Khinast, J G

    2015-08-01

    This paper describes a powder dosing system with a vibratory sieve mounted on a chute that doses particles into a capsule. Vertical vibration occurred with a broad range of frequencies and amplitudes. During dosing events, the fill weight was accurately recorded via a capacitance sensor, covering the capsules and making it possible to analyze filling characteristics, that is, the fill rates and their robustness. The range of frequencies and amplitudes was screened for settings that facilitated reasonable (no blocking, no spilling) fill rates for three lactose powders. The filling characteristics were studied within this operating space. The results reveal similar operating spaces for all investigated powders. The fill rate robustness varied distinctly in the operating space, which is of prime importance for selecting the settings for continuous feeding applications. In addition, we present accurate dosing studies utilizing the knowledge about the filling characteristics of each powder. PMID:26044188

  12. Sectioning of contaminated components for decontamination by vibratory finishing and electropolishing

    SciTech Connect

    Fetrow, L.K.; Allen, R.P.

    1981-09-01

    This report summarizes work conducted to develop, adapt, and evaluate a variety of techniques for sectioning glove boxes, chemical processing equipment, pipes, ducts, and other contaminated components in preparation for decontamination by vibratory finishing and electropolishing. These sectioning studies were conducted with a special 10-ft x 20-ft x 10-ft stainless-steel, walk-in glove box equipped for either hands-on operation via gloves and personnel entry, or remote operation using master slave manipulators and a bridge crane. Several sectioning techniques have been evaluated with respect to effectiveness, versatility, secondary waste generation, and capability for remote operation. The methods include wet and dry plasma arc torch cutting, mechanical sawing and nibbling, abrasive cutting, and hydraulic shearing and punching. The results of these comparison studies show that the plasma arc torch is a very rapid and effective metal cutting tool for size reduction applications. However, its use to prepare material for decontamination should be minimized because of problems with smoke generation, torch manipulation, waste generation, and entrainment of contamination. Mechanical saws eliminate all but the waste generation problem, but are very slow and labor intensive. Mechanical nibblers are fast and produce a waste form that can be decontaminated, but are limited with respect to the geometry and thickness of material that can be sectioned. High-speed abrasive saws provide high cutting rates, but produce nontreatable waste from the cut as well as from blade wear. Hydraulic shearing rapidly produces sectioned material in the small sizes required for decontamination by vibratory finishing. The kerf material also can be decontaminated. However, the glove box first must be sectioned into relatively narrow strips by one of the other techniques.

  13. An Intensified Vibratory Milling Process for Enhancing the Breakage Kinetics during the Preparation of Drug Nanosuspensions.

    PubMed

    Li, Meng; Zhang, Lu; Davé, Rajesh N; Bilgili, Ecevit

    2016-04-01

    As a drug-sparing approach in early development, vibratory milling has been used for the preparation of nanosuspensions of poorly water-soluble drugs. The aim of this study was to intensify this process through a systematic increase in vibration intensity and bead loading with the optimal bead size for faster production. Griseofulvin, a poorly water-soluble drug, was wet-milled using yttrium-stabilized zirconia beads with sizes ranging from 50 to 1500 μm at low power density (0.87 W/g). Then, this process was intensified with the optimal bead size by sequentially increasing vibration intensity and bead loading. Additional experiments with several bead sizes were performed at high power density (16 W/g), and the results were compared to those from wet stirred media milling. Laser diffraction, scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, and dissolution tests were used for characterization. Results for the low power density indicated 800 μm as the optimal bead size which led to a median size of 545 nm with more than 10% of the drug particles greater than 1.8 μm albeit the fastest breakage. An increase in either vibration intensity or bead loading resulted in faster breakage. The most intensified process led to 90% of the particles being smaller than 300 nm. At the high power intensity, 400 μm beads were optimal, which enhanced griseofulvin dissolution significantly and signified the importance of bead size in view of the power density. Only the optimally intensified vibratory milling led to a comparable nanosuspension to that prepared by the stirred media milling. PMID:26182907

  14. The nature of alarm communication in Constrictotermes cyphergaster (Blattodea: Termitoidea: Termitidae): the integration of chemical and vibroacoustic signals.

    PubMed

    Cristaldo, Paulo F; Jandák, Vojtĕch; Kutalová, Kateřina; Rodrigues, Vinícius B; Brothánek, Marek; Jiříček, Ondřej; DeSouza, Og; Šobotník, Jan

    2015-01-01

    Alarm signalling is of paramount importance to communication in all social insects. In termites, vibroacoustic and chemical alarm signalling are bound to operate synergistically but have never been studied simultaneously in a single species. Here, we inspected the functional significance of both communication channels in Constrictotermes cyphergaster (Termitidae: Nasutitermitinae), confirming the hypothesis that these are not exclusive, but rather complementary processes. In natural situations, the alarm predominantly attracts soldiers, which actively search for the source of a disturbance. Laboratory testing revealed that the frontal gland of soldiers produces a rich mixture of terpenoid compounds including an alarm pheromone. Extensive testing led to identification of the alarm pheromone being composed of abundant monoterpene hydrocarbons (1S)-α-pinene and myrcene, along with a minor component, (E)-β-ocimene. The vibratory alarm signalling consists of vibratory movements evidenced as bursts; a series of beats produced predominantly by soldiers. Exposing termite groups to various mixtures containing the alarm pheromone (crushed soldier heads, frontal gland extracts, mixture of all monoterpenes, and the alarm pheromone mixture made of standards) resulted in significantly higher activity in the tested groups and also increased intensity of the vibratory alarm communication, with the responses clearly dose-dependent. Lower doses of the pheromone provoked higher numbers of vibratory signals compared to higher doses. Higher doses induced long-term running of all termites without stops necessary to perform vibratory behaviour. Surprisingly, even crushed worker heads led to low (but significant) increases in the alarm responses, suggesting that other unknown compound in the worker's head is perceived and answered by termites. Our results demonstrate the existence of different alarm levels in termites, with lower levels being communicated through vibratory signals, and

  15. The nature of alarm communication in Constrictotermes cyphergaster (Blattodea: Termitoidea: Termitidae): the integration of chemical and vibroacoustic signals

    PubMed Central

    Cristaldo, Paulo F.; Jandák, Vojtĕch; Kutalová, Kateřina; Rodrigues, Vinícius B.; Brothánek, Marek; Jiříček, Ondřej; DeSouza, Og; Šobotník, Jan

    2015-01-01

    ABSTRACT Alarm signalling is of paramount importance to communication in all social insects. In termites, vibroacoustic and chemical alarm signalling are bound to operate synergistically but have never been studied simultaneously in a single species. Here, we inspected the functional significance of both communication channels in Constrictotermes cyphergaster (Termitidae: Nasutitermitinae), confirming the hypothesis that these are not exclusive, but rather complementary processes. In natural situations, the alarm predominantly attracts soldiers, which actively search for the source of a disturbance. Laboratory testing revealed that the frontal gland of soldiers produces a rich mixture of terpenoid compounds including an alarm pheromone. Extensive testing led to identification of the alarm pheromone being composed of abundant monoterpene hydrocarbons (1S)-α-pinene and myrcene, along with a minor component, (E)-β-ocimene. The vibratory alarm signalling consists of vibratory movements evidenced as bursts; a series of beats produced predominantly by soldiers. Exposing termite groups to various mixtures containing the alarm pheromone (crushed soldier heads, frontal gland extracts, mixture of all monoterpenes, and the alarm pheromone mixture made of standards) resulted in significantly higher activity in the tested groups and also increased intensity of the vibratory alarm communication, with the responses clearly dose-dependent. Lower doses of the pheromone provoked higher numbers of vibratory signals compared to higher doses. Higher doses induced long-term running of all termites without stops necessary to perform vibratory behaviour. Surprisingly, even crushed worker heads led to low (but significant) increases in the alarm responses, suggesting that other unknown compound in the worker's head is perceived and answered by termites. Our results demonstrate the existence of different alarm levels in termites, with lower levels being communicated through vibratory

  16. Diet-consumer nitrogen isotope fractionation for prolonged fasting arthropods.

    PubMed

    Mizota, Chitoshi; Yamanaka, Toshiro

    2011-12-01

    Nitrogen acquisition for cellular metabolism during diapause is a primary concern for herbivorous arthropods. Analyses of naturally occurring stable isotopes of nitrogen help elucidate the mechanism. Relevant articles have cited (58 times up to mid-June 2011) anomalously elevated δ(15)N (per mil deviation of (15)N/(14)N, relative to atmospheric nitrogen=0 ‰) values (diet-consumer nitrogen isotope fractionation; up to 12 ‰) for a prolonged fasting raspberry beetle (Byturus tomentosus Degeer (Coleoptera: Byturidae)), which feeds on red raspberries (Rubus idaeus: δ(15)N= ~ +2 ‰). Biologists have hypothesised that extensive recycling of amino acid nitrogen is responsible for the prolonged fasting. Since this hypothesis was proposed in 1995, scientists have integrated biochemical and molecular knowledge to support the mechanism of prolonged diapausing of animals. To test the validity of the recycling hypothesis, we analysed tissue nitrogen isotope ratios for four Japanese arthropods: the shield bug Parastrachia japonensis Scott (Hemiptera: Cydnidae), the burrower bug Canthophorus niveimarginatus Scott (Hemiptera: Cydnidae), leaf beetle Gastrophysa atrocyanea Motschulsky (Coleoptera: Chrysomelidae) and the Japanese oak silkworm Antheraea yamamai (Lepidoptera: Saturniidae), all of which fast for more than 6 months as part of their life-history strategy. Resulting diet-consumer nitrogen isotope discrimination during fasting ranged from 0 to 7‰, as in many commonly known terrestrial arthropods. We conclude that prolonged fasting of arthropods does not always result in anomalous diet-consumer nitrogen isotope fractionation, since the recycling process is closed or nearly closed with respect to nitrogen isotopes. PMID:22166153

  17. Effects of a Major Tree Invader on Urban Woodland Arthropods

    PubMed Central

    2015-01-01

    Biological invasions are a major threat to biodiversity; however, the degree of impact can vary depending on the ecosystem and taxa. Here, we test whether a top invader at a global scale, the tree Robinia pseudoacacia (black locust or false acacia), which is known to profoundly change site conditions, significantly affects urban animal diversity. As a first multi-taxon study of this kind, we analyzed the effects of Robinia dominance on 18 arthropod taxa by pairwise comparisons of woodlands in Berlin, Germany, that were dominated by R. pseudoacacia or the native pioneer tree Betula pendula. As a negative effect, abundances of five arthropod taxa decreased (Chilopoda, Formicidae, Diptera, Heteroptera, Hymenoptera); 13 others were not affected. Woodland type affected species composition of carabids and functional groups in spiders, but surprisingly did not decrease alpha and beta diversity of carabid and spider assemblages or the number of endangered species. Tree invasion thus did not induce biotic homogenization at the habitat scale. We detected no positive effects of alien dominance. Our results illustrate that invasions by a major tree invader can induce species turnover in ground-dwelling arthropods, but do not necessarily reduce arthropod species abundances or diversity and might thus contribute to the conservation of epigeal invertebrates in urban settings. Considering the context of invasion impacts thus helps to set priorities in managing biological invasions and can illustrate the potential of novel ecosystems to maintain urban biodiversity. PMID:26359665

  18. Microbial control of arthropod pests of tropical tree fruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microbial control agents (virus, bacteria, fungi, and nematodes) have been developed as alternative control methods of a wide variety of arthropod pests of a number of crops including tropical fruit. The majority of research and application in tropical fruit agroecosystems has been conducted in citr...

  19. Control of arthropod pests of tropical tree fruit with entomopathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A plethora of arthropods attack fruit crops throughout the tropics and sub-tropics. The predominant method for controlling most of these pests is the application of broad-spectrum chemical pesticides. Growing concern over the negative environmental effects has encouraged development of alternative c...

  20. Successive Gain of Insulator Proteins in Arthropod Evolution

    PubMed Central

    Heger, Peter; George, Rebecca; Wiehe, Thomas

    2013-01-01

    Alteration of regulatory DNA elements or their binding proteins may have drastic consequences for morphological evolution. Chromatin insulators are one example of such proteins and play a fundamental role in organizing gene expression. While a single insulator protein, CTCF (CCCTC-binding factor), is known in vertebrates, Drosophila melanogaster utilizes six additional factors. We studied the evolution of these proteins and show here that—in contrast to the bilaterian-wide distribution of CTCF—all other D. melanogaster insulators are restricted to arthropods. The full set is present exclusively in the genus Drosophila whereas only two insulators, Su(Hw) and CTCF, existed at the base of the arthropod clade and all additional factors have been acquired successively at later stages. Secondary loss of factors in some lineages further led to the presence of different insulator subsets in arthropods. Thus, the evolution of insulator proteins within arthropods is an ongoing and dynamic process that reshapes and supplements the ancient CTCF-based system common to bilaterians. Expansion of insulator systems may therefore be a general strategy to increase an organism’s gene regulatory repertoire and its potential for morphological plasticity. PMID:24094345

  1. Effects of a Major Tree Invader on Urban Woodland Arthropods.

    PubMed

    Buchholz, Sascha; Tietze, Hedwig; Kowarik, Ingo; Schirmel, Jens

    2015-01-01

    Biological invasions are a major threat to biodiversity; however, the degree of impact can vary depending on the ecosystem and taxa. Here, we test whether a top invader at a global scale, the tree Robinia pseudoacacia (black locust or false acacia), which is known to profoundly change site conditions, significantly affects urban animal diversity. As a first multi-taxon study of this kind, we analyzed the effects of Robinia dominance on 18 arthropod taxa by pairwise comparisons of woodlands in Berlin, Germany, that were dominated by R. pseudoacacia or the native pioneer tree Betula pendula. As a negative effect, abundances of five arthropod taxa decreased (Chilopoda, Formicidae, Diptera, Heteroptera, Hymenoptera); 13 others were not affected. Woodland type affected species composition of carabids and functional groups in spiders, but surprisingly did not decrease alpha and beta diversity of carabid and spider assemblages or the number of endangered species. Tree invasion thus did not induce biotic homogenization at the habitat scale. We detected no positive effects of alien dominance. Our results illustrate that invasions by a major tree invader can induce species turnover in ground-dwelling arthropods, but do not necessarily reduce arthropod species abundances or diversity and might thus contribute to the conservation of epigeal invertebrates in urban settings. Considering the context of invasion impacts thus helps to set priorities in managing biological invasions and can illustrate the potential of novel ecosystems to maintain urban biodiversity. PMID:26359665

  2. Book Review: Bioassays with Arthropods: 2nd Edition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The technical book "Bioassays with Arthropods: 2nd Edition" (2007. Jacqueline L. Robertson, Robert M. Russell, Haiganoush K, Preisler and N. E. Nevin, Eds. CRC Press, Boca Raton, FL, 224 pp.) was reviewed for the scientific readership of the peer-reviewed publication Journal of Economic Entomology. ...

  3. Manipulation of arthropod pathogens for integrated pest management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A great diversity of pathogenic microorganisms and nematodes has been developed for microbial biological control of insect and other arthropod pests. These control agents have many characteristics that determine their capacities to provide reliable pest control, and these characteristics must be ta...

  4. Horizontal Gene Transfer Contributes to the Evolution of Arthropod Herbivory

    PubMed Central

    Wybouw, Nicky; Pauchet, Yannick; Heckel, David G.; Van Leeuwen, Thomas

    2016-01-01

    Within animals, evolutionary transition toward herbivory is severely limited by the hostile characteristics of plants. Arthropods have nonetheless counteracted many nutritional and defensive barriers imposed by plants and are currently considered as the most successful animal herbivores in terrestrial ecosystems. We gather a body of evidence showing that genomes of various plant feeding insects and mites possess genes whose presence can only be explained by horizontal gene transfer (HGT). HGT is the asexual transmission of genetic information between reproductively isolated species. Although HGT is known to have great adaptive significance in prokaryotes, its impact on eukaryotic evolution remains obscure. Here, we show that laterally transferred genes into arthropods underpin many adaptations to phytophagy, including efficient assimilation and detoxification of plant produced metabolites. Horizontally acquired genes and the traits they encode often functionally diversify within arthropod recipients, enabling the colonization of more host plant species and organs. We demonstrate that HGT can drive metazoan evolution by uncovering its prominent role in the adaptations of arthropods to exploit plants. PMID:27307274

  5. EFFECTS OF MICROBIAL PESTICIDES ON NON-TARGET BENEFICIAL ARTHROPODS

    EPA Science Inventory

    The formulation, testing protocol, lethal effects, sub-lethal effects, ecological relationships and selectivity of microbial pesticides on non-target, beneficial arthropod natural enemies of insect and mite pests are reviewed for viruses, bacteria, fungi and protozoa. It was foun...

  6. Bioactivity of cedarwood oil and cedrol against arthropod pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heartwood samples from Juniperus virginiana, were extracted with liquid carbon dioxide and the bioactivity of carbon dioxide-derived cedarwood oil (CWO) towards several species of arthropods was investigated. Repellency or toxicity was tested for ants, ticks, and cockroaches. Ants in an outdoor bi...

  7. Arthropod Deterrents from Artemisia pallens (Davana Oil) Components.

    PubMed

    Bhagavathy, Ganga V; Velazquez Nieves, Glory M; Webb, Meiling Z; Chauhan, Kamlesh R

    2015-08-01

    Davanone, a key sesquiterpene component of davana oil, has been synthesized in five convenient steps. Oxygenated sesquiterpenes have been linked to insect deterrent properties. Based on initial screening of davana oil, davanone and its hydroxy precursors have been generated and are being evaluated as arthropod deterrents against disease vectors. PMID:26434107

  8. Application of remote sensing to arthropod vector surveillance and control.

    PubMed

    Washino, R K; Wood, B L

    1994-01-01

    A need exists to further develop new technologies, such as remote sensing and geographic information systems analysis, for estimating arthropod vector abundance in aquatic habitats and predicting adult vector population outbreaks. A brief overview of remote sensing technology in vector surveillance and control is presented, and suggestions are made on future research opportunities in light of current and proposed remote sensing systems. PMID:8024079

  9. Arthropod Surveillance Programs: Basic Components, Strategies, and Analysis

    PubMed Central

    Rochon, Kateryn; Duehl, Adrian J.; Anderson, John F.; Barrera, Roberto; Su, Nan-Yao; Gerry, Alec C.; Obenauer, Peter J.; Campbell, James F.; Lysyk, Tim J.; Allan, Sandra A.

    2015-01-01

    Effective entomological surveillance planning stresses a careful consideration of methodology, trapping technologies, and analysis techniques. Herein, the basic principles and technological components of arthropod surveillance plans are described, as promoted in the symposium “Advancements in arthropod monitoring technology, techniques, and analysis” presented at the 58th annual meeting of the Entomological Society of America in San Diego, CA. Interdisciplinary examples of arthropod monitoring for urban, medical, and veterinary applications are reviewed. Arthropod surveillance consists of the three components: 1) sampling method, 2) trap technology, and 3) analysis technique. A sampling method consists of selecting the best device or collection technique for a specific location and sampling at the proper spatial distribution, optimal duration, and frequency to achieve the surveillance objective. Optimized sampling methods are discussed for several mosquito species (Diptera: Culicidae) and ticks (Acari: Ixodidae). The advantages and limitations of novel terrestrial and aerial insect traps, artificial pheromones and kairomones are presented for the capture of red flour beetle (Coleoptera: Tenebrionidae), small hive beetle (Coleoptera: Nitidulidae), bed bugs (Hemiptera: Cimicidae), and Culicoides (Diptera: Ceratopogonidae) respectively. After sampling, extrapolating real world population numbers from trap capture data are possible with the appropriate analysis techniques. Examples of this extrapolation and action thresholds are given for termites (Isoptera: Rhinotermitidae) and red flour beetles. PMID:26543242

  10. Horizontal Gene Transfer Contributes to the Evolution of Arthropod Herbivory.

    PubMed

    Wybouw, Nicky; Pauchet, Yannick; Heckel, David G; Van Leeuwen, Thomas

    2016-01-01

    Within animals, evolutionary transition toward herbivory is severely limited by the hostile characteristics of plants. Arthropods have nonetheless counteracted many nutritional and defensive barriers imposed by plants and are currently considered as the most successful animal herbivores in terrestrial ecosystems. We gather a body of evidence showing that genomes of various plant feeding insects and mites possess genes whose presence can only be explained by horizontal gene transfer (HGT). HGT is the asexual transmission of genetic information between reproductively isolated species. Although HGT is known to have great adaptive significance in prokaryotes, its impact on eukaryotic evolution remains obscure. Here, we show that laterally transferred genes into arthropods underpin many adaptations to phytophagy, including efficient assimilation and detoxification of plant produced metabolites. Horizontally acquired genes and the traits they encode often functionally diversify within arthropod recipients, enabling the colonization of more host plant species and organs. We demonstrate that HGT can drive metazoan evolution by uncovering its prominent role in the adaptations of arthropods to exploit plants. PMID:27307274

  11. Extreme Arthropods: Exploring Evolutionary Adaptations to Polar and Temperate Deserts

    ERIC Educational Resources Information Center

    Sandro, Luke; Constible, Juanita M.; Lee, Richard E., Jr.

    2007-01-01

    In this activity, Namib and Antarctic arthropods are used to illustrate several important biological principles. Among these are the key ideas that form follows function and that the environment drives evolution. In addition, students will discover that the climates of the Namib Desert and the Antarctic Peninsula are similar in several ways, and…

  12. An Approach to Mark Arthropods for Mark Capture Type Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of studies were conducted to validate methods for marking a wide variety of arthropods with inexpensive proteins for mark-capture dispersal research. The markers tested included egg albumin protein in chicken egg whites and casein protein in bovine milk. The first study qualified the effec...

  13. Influence of crop management practices on bean foliage arthropods.

    PubMed

    Pereira, J L; Picanço, M C; Pereira, E J G; Silva, A A; Jakelaitis, A; Pereira, R R; Xavier, V M

    2010-12-01

    Crop management practices can affect the population of phytophagous pest species and beneficial arthropods with consequences for integrated pest management. In this study, we determined the effect of no-tillage and crop residue management on the arthropod community associated with the canopy of common beans (Phaseolus vulgaris L.). Abundance and species composition of herbivorous, detritivorous, predaceous and parasitoid arthropods were recorded during the growing seasons of 2003 and 2004 in Coimbra County, Minas Gerais State, Brazil. Arthropod diversity and guild composition were similar among crop management systems, but their abundance was higher under no-tillage relative to conventional cultivation and where residues from the preceding crop were maintained in the field. Thirty-four arthropod species were recorded, and those most representative of the impact of the crop management practices were Hypogastrura springtails, Empoasca kraemeri and Circulifer leafhoppers, and Solenopsis ants. The infestation levels of major insect-pests, especially leafhoppers (Hemiptera: Cicadellidae), was on average seven-fold lower under no-tillage with retention of crop residues relative to the conventional system with removal of residues, whereas the abundance of predatory ants (Hymenoptera: Formicidae) and springtails (Collembola: Hypogastruridae) were, respectively, about seven- and 15-fold higher in that treatment. Importantly, a significant trophic interaction among crop residues, detritivores, predators and herbivores was observed. Plots managed with no-tillage and retention of crop residues had the highest bean yield, while those with conventional cultivation and removal of the crop residues yielded significantly less beans. This research shows that cropping systems that include zero tillage and crop residue retention can reduce infestation by foliar insect-pests and increase abundance of predators and detritivores, thus having direct consequences for insect pest management

  14. Leaf litter arthropod responses to tropical forest restoration.

    PubMed

    Cole, Rebecca J; Holl, Karen D; Zahawi, Rakan A; Wickey, Philipp; Townsend, Alan R

    2016-08-01

    Soil and litter arthropods represent a large proportion of tropical biodiversity and perform important ecosystem functions, but little is known about the efficacy of different tropical forest restoration strategies in facilitating their recovery in degraded habitats. We sampled arthropods in four 7- to 8-year-old restoration treatments and in nearby reference forests. Sampling was conducted during the wet and dry seasons using extractions from litter and pitfall samples. Restoration treatments were replicated in 50 × 50-m plots in four former pasture sites in southern Costa Rica: plantation - trees planted throughout the plot; applied nucleation/islands - trees planted in patches of different sizes; and natural regeneration - no tree planting. Arthropod abundance, measures of richness and diversity, and a number of functional groups were greater in the island treatment than in natural regeneration or plantation treatments and, in many cases, were similar to reference forest. Litter and pitfall morphospecies and functional group composition in all three restoration treatments were significantly different than reference sites, but island and plantation treatments showed more recovery than natural regeneration. Abundance and functional group diversity showed a much greater degree of recovery than community composition. Synthesis and applications: The less resource-intensive restoration strategy of planting tree islands was more effective than tree plantations in restoring arthropod abundance, richness, and functional diversity. None of the restoration strategies, however, resulted in similar community composition as reference forest after 8 years of recovery, highlighting the slow rate of recovery of arthropod communities after disturbance, and underscoring the importance of conservation of remnant forests in fragmented landscapes. PMID:27551373

  15. Sampling of Stochastic Input Parameters for Rockfall Calculations and for Structural Response Calculations Under Vibratory Ground Motion

    SciTech Connect

    M. Gross

    2004-09-01

    The purpose of this scientific analysis is to define the sampled values of stochastic (random) input parameters for (1) rockfall calculations in the lithophysal and nonlithophysal zones under vibratory ground motions, and (2) structural response calculations for the drip shield and waste package under vibratory ground motions. This analysis supplies: (1) Sampled values of ground motion time history and synthetic fracture pattern for analysis of rockfall in emplacement drifts in nonlithophysal rock (Section 6.3 of ''Drift Degradation Analysis'', BSC 2004 [DIRS 166107]); (2) Sampled values of ground motion time history and rock mechanical properties category for analysis of rockfall in emplacement drifts in lithophysal rock (Section 6.4 of ''Drift Degradation Analysis'', BSC 2004 [DIRS 166107]); (3) Sampled values of ground motion time history and metal to metal and metal to rock friction coefficient for analysis of waste package and drip shield damage to vibratory motion in ''Structural Calculations of Waste Package Exposed to Vibratory Ground Motion'' (BSC 2004 [DIRS 167083]) and in ''Structural Calculations of Drip Shield Exposed to Vibratory Ground Motion'' (BSC 2003 [DIRS 163425]). The sampled values are indices representing the number of ground motion time histories, number of fracture patterns and rock mass properties categories. These indices are translated into actual values within the respective analysis and model reports or calculations. This report identifies the uncertain parameters and documents the sampled values for these parameters. The sampled values are determined by GoldSim V6.04.007 [DIRS 151202] calculations using appropriate distribution types and parameter ranges. No software development or model development was required for these calculations. The calculation of the sampled values allows parameter uncertainty to be incorporated into the rockfall and structural response calculations that support development of the seismic scenario for the

  16. Electroglottographic parameterization of the effects of gender, vowel and phonatory registers on vocal fold vibratory patterns: an Indian perspective.

    PubMed

    Paul, Nilanjan; Kumar, Suman; Chatterjee, Indranil; Mukherjee, Biswarup

    2011-01-01

    In-depth study on laryngeal biomechanics and vocal fold vibratory patterns reveal that a single vibratory cycle can be divided into two major phases, the closed and open phase, which is subdivided into opening and closing phases. Studies reveal that the relative time course of abduction and adduction, which in turn is dependent on the relative relaxing and tensing of the vocal fold cover and body, to be the determining factor in production of a particular vocal register like the modal (or chest), falsetto, glottal fry registers. Studies further point out Electroglottography to be particularly suitable for the study of vocal vibratory patterns during register changes. However, to date, there has been limited study on quantitative parameterization of EGG wave form in vocal fry register. Moreover, contradictory findings abound in literature regarding effects of gender and vowel types on vocal vibratory patterns, especially during phonation at different registers. The present study endeavors to find out the effects of vowel and gender differences on the vocal fold vibratory patterns in different registers and how these would be reflected in standard EGG parameters of Contact Quotient (CQ) and Contact Index (CI), taking into consideration the Indian sociolinguistic context. Electroglottographic recordings of 10 young adults (5 males and 5 females) were taken while the subjects phonated the three vowels /a/,/i/,/u/ each in two vocal registers, modal and vocal fry. Obtained raw EGG were further normalized using the Derived EGG algorithm and theCQ and CI values were derived. Obtained data were subject to statistical analysis using the 3-way ANOVA with gender, vowel and vocal register as the three variables. Post-hoc Dunnett C multiple comparison analysis were also performed. Results reveal that CQ values are significantly higher in vocal fry than modal phonation for both males and females, indicating a relatively hyperconstricted vocal system during vocal fry. The males

  17. Water balance in desert arthropods. Despite their small size, arthropods may be highly adapted for life in xeric conditions.

    PubMed

    Edney, E B

    1967-05-26

    As judged by the number of species, or of individuals, arthropods are an extremely successful group of desert inhabitants. There is very great structural and physiological diversity within the group, and since adaptations to desert life open to one are not open to all. we should not expect to find the maximum possible development of adaptive features in any arthropod simply because it lives in a desert. Most adult insects fly; their larvae and all other arthropods do not, and their adaptations will differ accordingly. Desert beetles have very impermeable cuticles and tolerate high body temperatures, while desert cockroaches live below the sand. have more permeable cuticles, and absorb water vapor. There is probably no single respect in which all desert arthropods differ from insects of other environments. Perhaps a profitable way of viewing desert animals is to recognize that each is a whole organism with a specific collection of adaptations that must be consistent within themselves and which are associated with a specific mode of life and a specific evolutionary history. The arthropod organization is capable of producing highly efficient desert species. There is, however, a converse way of looking at the situation, Which is often neglected but which may be of general biological interest: does the evolution of adaptations to desert environments necessarily involve loss of viability in more mesic habitats? If so, then what are these disavantages- what, for example, is the disadvantage of a highly impermeable cuticle? In some cases the answer is clear: sandroaches need sand dunes to live in because they are morphologically and behaviorly specialized for this habitat. More often the answer is not obvious. PMID:6024185

  18. Ecology and management of arthropod pests of poultry.

    PubMed

    Axtell, R C; Arends, J J

    1990-01-01

    The worldwide spread of modern, high-density confined poultry production systems under the direction of integrators has intensified the importance of a select number of arthropod ectoparasites and habitat pests. This concentrated production of poultry provides artificial ecosystems that are sometimes ideal for the development of large populations of arthropod pests. At the same time the systems are amenable to integrated pest management involving a multipest and multimethod approach to reducing or eliminating arthropod pests. Since rodents are major pests, they should be included in an integrated pest management program to make the program most cost-effective and attractive to the integrators and producers (5). Quantitative data are scarce on economic effects, and the concept of economic thresholds is difficult to apply either to ectoparasites or to habitat pests. The risk of transporting ectoparasites among flocks is difficult to evaluate and necessitates treatment after early detection of the arthropods. Flies and litter beetles present a threat of disease transmission and the potential for lawsuits from neighbors or public health agencies that are factors not subject to easy cost estimates. The monetary losses of a flock devastated by disease or a farm forced to close are so great that the risks are unacceptable. Production losses from lowered feed conversion ratios and insulation damage are likely to be detected by the sophisticated record-keeping of the integrators. Minimal use of pesticides and other chemicals on poultry and in poultry housing is an objective of the integrators and, consequently, an integrated pest management (IPM) approach that reduces the need for pesticides is attractive. The key to further development of effective arthropod management programs for poultry is the implementation of pest and disease monitoring programs for the complete system. Improvements in arthropod sampling methods and more attention to monitoring the biosecurity systems

  19. Characterizing the Effective Bandwidth of Nonlinear Vibratory Energy Harvesters Possessing Multiple Stable Equilibria

    NASA Astrophysics Data System (ADS)

    Panyam Mohan Ram, Meghashyam

    In the last few years, advances in micro-fabrication technologies have lead to the development of low-power electronic devices spanning critical fields related to sensing, data transmission, and medical implants. Unfortunately, effective utilization of these devices is currently hindered by their reliance on batteries. In many of these applications, batteries may not be a viable choice as they have a fixed storage capacity and need to be constantly replaced or recharged. In light of such challenges, several novel concepts for micro-power generation have been recently introduced to harness, otherwise, wasted ambient energy from the environment and maintain these low-power devices. Vibratory energy harvesting is one such concept which has received significant attention in recent years. While linear vibratory energy harvesters have been well studied in the literature and their performance metrics have been established, recent research has focused on deliberate introduction of stiffness nonlinearities into the design of these devices. It has been shown that, nonlinear energy harvesters have a wider steady-state frequency bandwidth as compared to their linear counterparts, leading to the premise that they can used to improve performance, and decrease sensitivity to variations in the design and excitation parameters. This dissertation aims to investigate this premise by developing an analytical framework to study the influence of stiffness nonlinearities on the performance and effective bandwidth of nonlinear vibratory energy harvesters. To achieve this goal, the dissertation is divided into three parts. The first part investigates the performance of bi-stable energy harvesters possessing a symmetric quartic potential energy function under harmonic excitations and carries out a detailed analysis to define their effective frequency bandwidth. The second part investigates the relative performance of mono- and bi-stable energy harvesters under optimal electric loading

  20. Analysis of rabbit intervertebral disc physiology based on water metabolism. II. Changes in normal intervertebral discs under axial vibratory load

    SciTech Connect

    Hirano, N.; Tsuji, H.; Ohshima, H.; Kitano, S.; Itoh, T.; Sano, A.

    1988-11-01

    Metabolic changes induced by axial vibratory load to the spine were investigated based on water metabolism in normal intervertebral discs of rabbits with or without pentobarbital anesthesia. Tritiated water concentration in the intervertebral discs of unanesthetized rabbits was reduced remarkably by axial vibration for 30 minutes using the vibration machine developed for this study. Repeated vibratory load for 18 and 42 hours duration showed the recovery of /sup 3/H/sub 2/O concentration of the intervertebral disc without anesthesia. Computer simulation suggested a reduction of blood flow surrounding the intervertebral disc following the vibration stress. However, no reduction of the /sup 3/H/sub 2/O concentration in the intervertebral disc was noted under anesthesia. Emotional stress cannot be excluded as a factor in water metabolism in the intervertebral disc.

  1. Finite Element Method Simulation of Double-T Type Vibrators for Flatly Supported Piezoelectric Vibratory Gyro-Sensor

    NASA Astrophysics Data System (ADS)

    Kikuchi, Takayuki; Tomikawa, Yoshiro; Soma, Takao

    2001-05-01

    In this study we deal with a flexural vibrating resonator for flatly supported vibratory gyro-sensors in parallel with the rotating plane. This type of gyro-sensor uses two vibration modes in only one plane of single crystal quartz, and therefore can be constructed to be very stable under operating conditions. The double-T type vibrator that has two T-type resonating arms and two resonant arms is designed for improving the quality factor Q of both driving and detecting vibration modes for this vibratory gyro-sensor. The result of finite element analysis of the double-T type vibrators shows the small influence of its vibration mode with the support at the center of gravity of the vibrator.

  2. Vibratory response of a mirror support/positioning system for the Advanced Photon Source project at Argonne National Laboratory

    SciTech Connect

    Basdogan, I.; Shu, Deming; Kuzay, T.M.; Royston, T.J.; Shabana, A.A.

    1996-08-01

    The vibratory response of a typical mirror support/positioning system used at the experimental station of the Advanced Photon Source (APS) project at Argonne National Laboratory is investigated. Positioning precision and stability are especially critical when the supported mirror directs a high-intensity beam aimed at a distant target. Stability may be compromised by low level, low frequency seismic and facility-originated vibrations traveling through the ground and/or vibrations caused by flow-structure interactions in the mirror cooling system. The example case system has five positioning degrees of freedom through the use of precision actuators and rotary and linear bearings. These linkage devices result in complex, multi-dimensional vibratory behavior that is a function of the range of positioning configurations. A rigorous multibody dynamical approach is used for the development of the system equations. Initial results of the study, including estimates of natural frequencies and mode shapes, as well as limited parametric design studies, are presented. While the results reported here are for a particular system, the developed vibratory analysis approach is applicable to the wide range of high-precision optical positioning systems encountered at the APS and at other comparable facilities.

  3. Investigating acoustic correlates of human vocal fold vibratory phase asymmetry through modeling and laryngeal high-speed videoendoscopya

    PubMed Central

    Mehta, Daryush D.; Zañartu, Matías; Quatieri, Thomas F.; Deliyski, Dimitar D.; Hillman, Robert E.

    2011-01-01

    Vocal fold vibratory asymmetry is often associated with inefficient sound production through its impact on source spectral tilt. This association is investigated in both a computational voice production model and a group of 47 human subjects. The model provides indirect control over the degree of left–right phase asymmetry within a nonlinear source–filter framework, and high-speed videoendoscopy provides in vivo measures of vocal fold vibratory asymmetry. Source spectral tilt measures are estimated from the inverse-filtered spectrum of the simulated and recorded radiated acoustic pressure. As expected, model simulations indicate that increasing left–right phase asymmetry induces steeper spectral tilt. Subject data, however, reveal that none of the vibratory asymmetry measures correlates with spectral tilt measures. Probing further into physiological correlates of spectral tilt that might be affected by asymmetry, the glottal area waveform is parameterized to obtain measures of the open phase (open/plateau quotient) and closing phase (speed/closing quotient). Subjects’ left–right phase asymmetry exhibits low, but statistically significant, correlations with speed quotient (r = 0.45) and closing quotient (r = −0.39). Results call for future studies into the effect of asymmetric vocal fold vibration on glottal airflow and the associated impact on voice source spectral properties and vocal efficiency. PMID:22225054

  4. Perception of frequency, amplitude, and azimuth of a vibratory dipole source by the octavolateralis system of goldfish (Carassius auratus).

    PubMed

    Dailey, Deena D; Braun, Christopher B

    2011-08-01

    Goldfish (Carassius auratus) were conditioned to suppress respiration to a 40-Hz vibratory source and subsequently tested for stimulus generalization to frequency, stimulus amplitude, and position (azimuth). Animals completely failed to generalize to frequencies separated by octave intervals both lesser and greater than the CS. However, they did appear to generalize weakly to an aerial loudspeaker stimulus of the same frequency (40 Hz) after conditioning with an underwater vibratory source. Animals had a gradually decreasing amount of generalization to amplitude changes, suggesting a perceptual dimension of loudness. Animals generalized largely or completely to the same underwater source presented at a range of source azimuths. When these azimuths were presented at a transect of 3 cm, some animals did show decrements in generalization, while others did not. This suggests that although azimuth may be perceived more saliently at distances closer to a dipole source, perception of position is not immediately salient in conditioned vibratory source detection. Differential responding to test stimuli located toward the head or tail suggests the presence of perceptual differences between sources that are rostral or caudal with respect to the position of the animal or perhaps the head. PMID:21574689

  5. The effects of goshajinkigan, a herbal medicine, on subjective symptoms and vibratory threshold in patients with diabetic neuropathy.

    PubMed

    Tawata, M; Kurihara, A; Nitta, K; Iwase, E; Gan, N; Onaya, T

    1994-12-16

    Goshajinkigan, a herbal medicine, has long been used in Japan to alleviate the subjective symptoms of diabetic neuropathy; however, its effects have not been confirmed objectively. We evaluated its effects on subjective symptoms and on vibration sensation in patients with diabetic neuropathy. The oral administration of 7.5 g/day of Goshajinkigan for 3 months (treatment period) relieved subjective symptoms of numbness in 9 of 13 patients. When the drug was discontinued for 2 months as a washout period, the subjective symptom worsened in 7 of 13 patients. Chi-square analysis revealed significant effects of Goshajiniagan on subjective symptoms (P < 0.001 for numbness and P < 0.05 for cold sensation). Vibration sensation was evaluated by measuring vibratory threshold using an SMV-5 vibrometer. There were significant changes in vibratory thresholds by paired t-test (P < 0.05) both in the upper and the lower extremities during the treatment and washout periods. Chi-square analysis also revealed a significant effect of Goshajinkigan on vibratory threshold (P < 0.01). There was no significant change in glycosylated hemoglobin as a whole during the study. These observations confirm that Goshajinkigan relieves subjective symptoms and demonstrate that it improves vibration sensation in patients with diabetic neuropathy. PMID:7705193

  6. Survey of the arthropods on jojoba (Simmondsia chinensis)

    SciTech Connect

    Pinto, J.D.; Frommer, S.I.

    1980-02-01

    Simmondsia chinensis (jojoba), a plant native to southwestern North America, has become of economic interest due to the various industrial uses of the unique liquid wax found in its seeds. In a survey of arthropods associated with sylvatic jojoba in California and Arizona, we collected 106 species of insects and mites. Of these, 50 are phytophagous, 29 are parasitic, and 18 are predaceous. Most of the phytophagous species are also known to feed on plants other than jojoba; several of these are notorious generalists. The bionomics of the 4 commonest phytophagous species, Asphondylia n. sp. (Cecidomyiidae), Epinotia kasloana (Olethreutidae), Periploca n. sp. (Walshiidae), and Incisitermes fruticavus (Kalotermitidae) are summarized briefly. None of the phytophagous species were observed to cause extensive damage to sylvatic jojoba. The numerous parasitic and predaceous arthropods probably account for the natural control of many of them. These relationships should be kept in mind when planning future commercial plantations of jojoba.

  7. Personal Protection Measures Against Mosquitoes, Ticks, and Other Arthropods.

    PubMed

    Alpern, Jonathan D; Dunlop, Stephen J; Dolan, Benjamin J; Stauffer, William M; Boulware, David R

    2016-03-01

    Arthropod-associated diseases are a major cause of morbidity among travelers. Obtaining a detailed travel itinerary and understanding traveler-specific and destination-specific risk factors can help mitigate the risk of vector-borne diseases. DEET, picaridin, PMD, and IR3535 are insect repellents that offer sufficient protection against arthropod bites. IR3535 does not provide adequate protection against Anopheles mosquitoes, and should be avoided in malaria-endemic regions. General protective measures, such as bite avoidance, protective clothing, insecticide-treated bed nets, and insecticide-treated clothing, should be recommended, especially in malaria-endemic areas. Spatial repellents may prevent nuisance biting, but have not been shown to prevent against vector-borne disease. PMID:26900115

  8. Arthropod-Borne Diseases: The Camper's Uninvited Guests.

    PubMed

    Juckett, Gregory

    2015-08-01

    Arthropod-borne diseases are a major problem whenever outdoor activities bring arthropods and people into contact. The arthropods discussed here include arachnids (ticks) and insects. Most arthropod bites and stings are minor, with the notable exception being bee-sting anaphylaxis. Ticks cause the most disease transmission. Key hard tick vectors include black-legged (Ixodes), dog (Dermacentor), and lone star (Amblyomma) ticks, which transmit Lyme and various rickettsial diseases. Insect repellents, permethrin sprays, and proper tick inspection reduce this risk significantly. Lyme disease and the milder southern-tick-associated rash illness (STARI) are characterized by the erythema migrans rash followed, in the case of Lyme disease, by early, disseminated, and late systemic symptoms. Treatment is with doxycycline or ceftriaxone. Indefinite treatment of "chronic Lyme disease" based on subjective symptoms is not beneficial. Rickettsial diseases include ehrlichiosis, anaplasmosis, and Rocky Mountain spotted fever, which are characterized by fever, headache, and possible rash and should be empirically treated with doxycycline while awaiting laboratory confirmation. Tularemia is a bacterial disease (Francisella) spread by ticks and rabbits and characterized by fever and adenopathy. Treatment is with gentamicin or streptomycin. Babesiosis is a protozoal disease, mimicking malaria, that causes a self-limited flu-like disease in healthy hosts but can be life threatening with immune compromise. Treatment is with atovaquone and azithromycin. Other tick-related conditions include viral diseases (Powassan, Colorado tick fever, heartland virus), tick-borne relapsing fever (Borrelia), and tick paralysis (toxin). Mosquitoes, lice, fleas, and mites are notable for their annoying bites but are increasingly significant disease vectors even in the United States. PMID:26350321

  9. Cyberdiversity: Improving the Informatic Value of Diverse Tropical Arthropod Inventories

    PubMed Central

    Miller, Jeremy A.; Miller, Joshua H.; Pham, Dinh-Sac; Beentjes, Kevin K.

    2014-01-01

    In an era of biodiversity crisis, arthropods have great potential to inform conservation assessment and test hypotheses about community assembly. This is because their relatively narrow geographic distributions and high diversity offer high-resolution data on landscape-scale patterns of biodiversity. However, a major impediment to the more widespread application of arthropod data to a range of scientific and policy questions is the poor state of modern arthropod taxonomy, especially in the tropics. Inventories of spiders and other megadiverse arthropods from tropical forests are dominated by undescribed species. Such studies typically organize their data using morphospecies codes, which make it difficult for data from independent inventories to be compared and combined. To combat this shortcoming, we offer cyberdiversity, an online community-based approach for reconciling results of independent inventory studies where current taxonomic knowledge is incomplete. Participating scientists can upload images and DNA barcode sequences to dedicated databases and submit occurrence data and links to a web site (www.digitalSpiders.org). Taxonomic determinations can be shared with a crowdsourcing comments feature, and researchers can discover specimens of interest available for loan and request aliquots of genomic DNA extract. To demonstrate the value of the cyberdiversity framework, we reconcile data from three rapid structured inventories of spiders conducted in Vietnam with an independent inventory (Doi Inthanon, Thailand) using online image libraries. Species richness and inventory completeness were assessed using non-parametric estimators. Community similarity was evaluated using a novel index based on the Jaccard replacing observed with estimated values to correct for unobserved species. We use a distance-decay framework to demonstrate a rudimentary model of landscape-scale changes in community composition that will become increasingly informative as additional

  10. Cyberdiversity: improving the informatic value of diverse tropical arthropod inventories.

    PubMed

    Miller, Jeremy A; Miller, Joshua H; Pham, Dinh-Sac; Beentjes, Kevin K

    2014-01-01

    In an era of biodiversity crisis, arthropods have great potential to inform conservation assessment and test hypotheses about community assembly. This is because their relatively narrow geographic distributions and high diversity offer high-resolution data on landscape-scale patterns of biodiversity. However, a major impediment to the more widespread application of arthropod data to a range of scientific and policy questions is the poor state of modern arthropod taxonomy, especially in the tropics. Inventories of spiders and other megadiverse arthropods from tropical forests are dominated by undescribed species. Such studies typically organize their data using morphospecies codes, which make it difficult for data from independent inventories to be compared and combined. To combat this shortcoming, we offer cyberdiversity, an online community-based approach for reconciling results of independent inventory studies where current taxonomic knowledge is incomplete. Participating scientists can upload images and DNA barcode sequences to dedicated databases and submit occurrence data and links to a web site (www.digitalSpiders.org). Taxonomic determinations can be shared with a crowdsourcing comments feature, and researchers can discover specimens of interest available for loan and request aliquots of genomic DNA extract. To demonstrate the value of the cyberdiversity framework, we reconcile data from three rapid structured inventories of spiders conducted in Vietnam with an independent inventory (Doi Inthanon, Thailand) using online image libraries. Species richness and inventory completeness were assessed using non-parametric estimators. Community similarity was evaluated using a novel index based on the Jaccard replacing observed with estimated values to correct for unobserved species. We use a distance-decay framework to demonstrate a rudimentary model of landscape-scale changes in community composition that will become increasingly informative as additional

  11. Mechanisms of Arthropod Transmission of Plant and Animal Viruses

    PubMed Central

    Gray, Stewart M.; Banerjee, Nanditta

    1999-01-01

    A majority of the plant-infecting viruses and many of the animal-infecting viruses are dependent upon arthropod vectors for transmission between hosts and/or as alternative hosts. The viruses have evolved specific associations with their vectors, and we are beginning to understand the underlying mechanisms that regulate the virus transmission process. A majority of plant viruses are carried on the cuticle lining of a vector’s mouthparts or foregut. This initially appeared to be simple mechanical contamination, but it is now known to be a biologically complex interaction between specific virus proteins and as yet unidentified vector cuticle-associated compounds. Numerous other plant viruses and the majority of animal viruses are carried within the body of the vector. These viruses have evolved specific mechanisms to enable them to be transported through multiple tissues and to evade vector defenses. In response, vector species have evolved so that not all individuals within a species are susceptible to virus infection or can serve as a competent vector. Not only are the virus components of the transmission process being identified, but also the genetic and physiological components of the vectors which determine their ability to be used successfully by the virus are being elucidated. The mechanisms of arthropod-virus associations are many and complex, but common themes are beginning to emerge which may allow the development of novel strategies to ultimately control epidemics caused by arthropod-borne viruses. PMID:10066833

  12. Preliminary observations of arthropods associated with buried carrion on Oahu.

    PubMed

    Rysavy, Noel M; Goff, M Lee

    2015-03-01

    Several studies in Hawaii have focused on arthropod succession and decomposition patterns of surface remains, but the current research presents the first study to focus on shallow burials in this context. Three domestic pig carcasses (Sus scrofa L.) were buried at the depths of 20-40 cm in silty clay loam soil on an exposed ridge on the leeward side of the volcanically formed Koolau Mountain Range. One carcass was exhumed after 3 weeks, another after 6 weeks, and the last carcass was exhumed after 9 weeks. An inventory of arthropod taxa present on the carrion and in the surrounding soil and observations pertaining to decomposition were recorded at each exhumation. The longer the carrion was buried, the greater the diversity of arthropod species that were recovered from the remains. Biomass loss was calculated to be 49% at the 3-week interval, 56% at the 6-week interval, and 59% at the 9-week interval. PMID:25413711

  13. Genetic diversity in aspen and its relation to arthropod abundance

    PubMed Central

    Zhang, Chunxia; Vornam, Barbara; Volmer, Katharina; Prinz, Kathleen; Kleemann, Frauke; Köhler, Lars; Polle, Andrea; Finkeldey, Reiner

    2015-01-01

    The ecological consequences of biodiversity have become a prominent public issue. Little is known on the effect of genetic diversity on ecosystem services. Here, a diversity experiment was established with European and North American aspen (Populus tremula, P. tremuloides) planted in plots representing either a single deme only or combinations of two, four and eight demes. The goals of this study were to explore the complex inter- and intraspecific genetic diversity of aspen and to then relate three measures for diversity (deme diversity, genetic diversity determined as Shannon index or as expected heterozygosity) to arthropod abundance. Microsatellite and AFLP markers were used to analyze the genetic variation patterns within and between the aspen demes and deme mixtures. Large differences were observed regarding the genetic diversity within demes. An analysis of molecular variance revealed that most of the total genetic diversity was found within demes, but the genetic differentiation among demes was also high. The complex patterns of genetic diversity and differentiation resulted in large differences of the genetic variation within plots. The average diversity increased from plots with only one deme to plots with two, four, and eight demes, respectively and separated plots with and without American aspen. To test whether intra- and interspecific diversity impacts on ecosystem services, arthropod abundance was determined. Increasing genetic diversity of aspen was related to increasing abundance of arthropods. However, the relationship was mainly driven by the presence of American aspen suggesting that species identity overrode the effect of intraspecific variation of European aspen. PMID:25674097

  14. Digital cameras with designs inspired by the arthropod eye.

    PubMed

    Song, Young Min; Xie, Yizhu; Malyarchuk, Viktor; Xiao, Jianliang; Jung, Inhwa; Choi, Ki-Joong; Liu, Zhuangjian; Park, Hyunsung; Lu, Chaofeng; Kim, Rak-Hwan; Li, Rui; Crozier, Kenneth B; Huang, Yonggang; Rogers, John A

    2013-05-01

    In arthropods, evolution has created a remarkably sophisticated class of imaging systems, with a wide-angle field of view, low aberrations, high acuity to motion and an infinite depth of field. A challenge in building digital cameras with the hemispherical, compound apposition layouts of arthropod eyes is that essential design requirements cannot be met with existing planar sensor technologies or conventional optics. Here we present materials, mechanics and integration schemes that afford scalable pathways to working, arthropod-inspired cameras with nearly full hemispherical shapes (about 160 degrees). Their surfaces are densely populated by imaging elements (artificial ommatidia), which are comparable in number (180) to those of the eyes of fire ants (Solenopsis fugax) and bark beetles (Hylastes nigrinus). The devices combine elastomeric compound optical elements with deformable arrays of thin silicon photodetectors into integrated sheets that can be elastically transformed from the planar geometries in which they are fabricated to hemispherical shapes for integration into apposition cameras. Our imaging results and quantitative ray-tracing-based simulations illustrate key features of operation. These general strategies seem to be applicable to other compound eye devices, such as those inspired by moths and lacewings (refracting superposition eyes), lobster and shrimp (reflecting superposition eyes), and houseflies (neural superposition eyes). PMID:23636401

  15. Evolution, discovery, and interpretations of arthropod mushroom bodies.

    PubMed

    Strausfeld, N J; Hansen, L; Li, Y; Gomez, R S; Ito, K

    1998-01-01

    Mushroom bodies are prominent neuropils found in annelids and in all arthropod groups except crustaceans. First explicitly identified in 1850, the mushroom bodies differ in size and complexity between taxa, as well as between different castes of a single species of social insect. These differences led some early biologists to suggest that the mushroom bodies endow an arthropod with intelligence or the ability to execute voluntary actions, as opposed to innate behaviors. Recent physiological studies and mutant analyses have led to divergent interpretations. One interpretation is that the mushroom bodies conditionally relay to higher protocerebral centers information about sensory stimuli and the context in which they occur. Another interpretation is that they play a central role in learning and memory. Anatomical studies suggest that arthropod mushroom bodies are predominately associated with olfactory pathways except in phylogenetically basal insects. The prominent olfactory input to the mushroom body calyces in more recent insect orders is an acquired character. An overview of the history of research on the mushroom bodies, as well as comparative and evolutionary considerations, provides a conceptual framework for discussing the roles of these neuropils. PMID:10454370

  16. Structural Diversity of Self-Assembled Iridescent Arthropod Biophotonic Nanostructures

    NASA Astrophysics Data System (ADS)

    Saranathan, Vinod Kumar; Prum, Richard O.

    2015-03-01

    Many organisms, especially arthropods, produce vivid interference colors using diverse mesoscopic (100-350 nm) integumentary biophotonic nanostructures that are increasingly being investigated for technological applications. Despite a century of interest, we lack precise structural knowledge of many biophotonic nanostructures and mechanisms controlling their development, when such knowledge can open novel biomimetic routes to facilely self-assemble tunable, multi-functional materials. Here, we use synchrotron small angle X-ray scattering and electron microscopy to characterize the photonic nanostructure of 140 iridescent integumentary scales and setae from 127 species of terrestrial arthropods in 85 genera from 5 orders. We report a rich nanostructural diversity, including triply-periodic bicontinuous networks, close-packed spheres, inverse columnar, perforated lamellar, and disordered sponge-like morphologies, commonly observed as stable phases of amphiphilic surfactants, block copolymer, and lyotropic lipid-water systems. Diverse arthropod lineages appear to have independently evolved to utilize the self-assembly of infolding bilayer membranes to develop biophotonic nanostructures that span the phase-space of amphiphilic morphologies, but at optical length scales.

  17. Evolution, Discovery, and Interpretations of Arthropod Mushroom Bodies

    PubMed Central

    Strausfeld, Nicholas J.; Hansen, Lars; Li, Yongsheng; Gomez, Robert S.; Ito, Kei

    1998-01-01

    Mushroom bodies are prominent neuropils found in annelids and in all arthropod groups except crustaceans. First explicitly identified in 1850, the mushroom bodies differ in size and complexity between taxa, as well as between different castes of a single species of social insect. These differences led some early biologists to suggest that the mushroom bodies endow an arthropod with intelligence or the ability to execute voluntary actions, as opposed to innate behaviors. Recent physiological studies and mutant analyses have led to divergent interpretations. One interpretation is that the mushroom bodies conditionally relay to higher protocerebral centers information about sensory stimuli and the context in which they occur. Another interpretation is that they play a central role in learning and memory. Anatomical studies suggest that arthropod mushroom bodies are predominately associated with olfactory pathways except in phylogenetically basal insects. The prominent olfactory input to the mushroom body calyces in more recent insect orders is an acquired character. An overview of the history of research on the mushroom bodies, as well as comparative and evolutionary considerations, provides a conceptual framework for discussing the roles of these neuropils. PMID:10454370

  18. Electrophysiological responses to vibratory stimulation in the brainstem of the tadpole

    NASA Astrophysics Data System (ADS)

    Simmons, Andrea M.; Two, Aimee; Horowitz, Seth S.

    2005-04-01

    Maturation of saccular responses to vibratory stimuli in 3 axes was measured in the Rana catesbeiana tadpole across metamorphic development. The animal was suspended in a water-filled circular aluminum dish attached to a shaker table system consisting of 5 vibration exciters producing sinusoidal, translational movements in the x, y, and z planes. Multi-unit responses were recorded from the medulla with tungsten or platinum-iridium microelectrodes. Recording sites were electrolytically marked to verify electrode placement. Data were collected from 16 animals in late larval stages, before onset of metamorphic climax. Most recording sites were sensitive to vibrations in the z (vertical) direction, indicating a saccular origin of the response. Vibration frequencies of 40 Hz or below produced the strongest activity, with thresholds below a displacement of 10 nm. Secondary sensitivity was sometimes observed to either x (body-longitudinal) or y (body-lateral) directions of movement. Although some sites produced strong phase-locked activity to the stimulation, others showed more diverse temporal patterns of response. Active recording sites were found in the medial vestibular nucleus, lateral vestibular nucleus, reticular gray, and dorsal superior olivary nucleus. These data suggest that tadpole saccule is functional early in larval development, with sensitivity similar to that observed in adult bullfrogs.

  19. Design of vibratory energy harvesters under stochastic parametric uncertainty: a new optimization philosophy

    NASA Astrophysics Data System (ADS)

    Haji Hosseinloo, Ashkan; Turitsyn, Konstantin

    2016-05-01

    Vibratory energy harvesters as potential replacements for conventional batteries are not as robust as batteries. Their performance can drastically deteriorate in the presence of uncertainty in their parameters. Parametric uncertainty is inevitable with any physical device mainly due to manufacturing tolerances, defects, and environmental effects such as temperature and humidity. Hence, uncertainty propagation analysis and optimization under uncertainty seem indispensable with any energy harvester design. Here we propose a new modeling philosophy for optimization under uncertainty; optimization for the worst-case scenario (minimum power) rather than for the ensemble expectation of the power. The proposed optimization philosophy is practically very useful when there is a minimum requirement on the harvested power. We formulate the problems of uncertainty propagation and optimization under uncertainty in a generic and architecture-independent fashion, and then apply them to a single-degree-of-freedom linear piezoelectric energy harvester with uncertainty in its different parameters. The simulation results show that there is a significant improvement in the worst-case power of the designed harvester compared to that of a naively optimized (deterministically optimized) harvester. For instance, for a 10% uncertainty in the natural frequency of the harvester (in terms of its standard deviation) this improvement is about 570%.

  20. Optimization of partial-state feedback for vibratory energy harvesters subjected to broadband stochastic disturbances

    NASA Astrophysics Data System (ADS)

    Cassidy, Ian L.; Scruggs, Jeffrey T.; Behrens, Sam

    2011-08-01

    In many applications of vibratory energy harvesting, the external disturbance is most appropriately modeled as a broadband stochastic process. Optimization of the average power generated from such disturbances is a feedback control problem, and solvable via LQG (linear-quadratic-Gaussian) control theory. Implementing the optimal feedback controller requires a power electronic drive capable of two-way power flow, which can impose dynamic relationships between the voltage and current of the transducer. Determining the optimal energy harvesting current control is accomplished by solving a nonstandard Riccati equation. In this paper we show that appropriate tuning of the passive parameters in the harvesting system results in a decoupled solution to the Riccati equation and a corresponding controller that only requires half of the states for feedback. However, even when such tuning methods are not used and the solution to the Riccati equation does not decouple, it is possible to determine the states in the feedback law that contribute the most to the average power generated by the harvester. As such, partial-state feedback gains can be optimized using a gradient descent method. Two energy harvesting examples are presented, including a single-degree-of-freedom oscillator with an electromagnetic actuator and a piezoelectric bimorph cantilever beam, to demonstrate these concepts.

  1. Stochastic parameter estimation in nonlinear time-delayed vibratory systems with distributed delay

    NASA Astrophysics Data System (ADS)

    Torkamani, Shahab; Butcher, Eric A.

    2013-07-01

    The stochastic estimation of parameters and states in linear and nonlinear time-delayed vibratory systems with distributed delay is explored. The approach consists of first employing a continuous time approximation to approximate the delayed integro-differential system with a large set of ordinary differential equations having stochastic excitations. Then the problem of state and parameter estimation in the resulting stochastic ordinary differential system is represented as an optimal filtering problem using a state augmentation technique. By adapting the extended Kalman-Bucy filter to the augmented filtering problem, the unknown parameters of the time-delayed system are estimated from noise-corrupted, possibly incomplete measurements of the states. Similarly, the upper bound of the distributed delay can also be estimated by the proposed technique. As an illustrative example to a practical problem in vibrations, the parameter, delay upper bound, and state estimation from noise-corrupted measurements in a distributed force model widely used for modeling machine tool vibrations in the turning operation is investigated.

  2. Two Novel Measurements for the Drive-Mode Resonant Frequency of a Micromachined Vibratory Gyroscope

    PubMed Central

    Wang, Ancheng; Hu, Xiaoping; Luo, Bing; Jiang, Mingming; He, Xiaofeng; Tang, Kanghua

    2013-01-01

    To investigate the drive-mode resonance frequency of a micromachined vibratory gyroscope (MVG), one needs to measure it accurately and efficiently. The conventional approach to measure the resonant frequency is by performing a sweep frequency test and spectrum analysis. The method is time-consuming and inconvenient because of the requirements of many test points, a lot of data storage and off-line analyses. In this paper, we propose two novel measurement methods, the search method and track method, respectively. The former is based on the magnitude-frequency characteristics of the drive mode, utilizing a one-dimensional search technique. The latter is based on the phase-frequency characteristics, applying a feedback control loop. Their performances in precision, noise resistivity and efficiency are analyzed through detailed simulations. A test system is implemented based on a field programmable gate array (FPGA) and experiments are carried out. By comparing with the common approach, feasibility and superiorities of the proposed methods are validated. In particular, significant efficiency improvements are achieved whereby the conventional frequency method consumes nearly 5,000 s to finish a measurement, while only 5 s is needed for the track method and 1 s for the search method. PMID:24256977

  3. Programmable Mechanobioreactor for Exploration of the Effects of Periodic Vibratory Stimulus on Mesenchymal Stem Cell Differentiation

    PubMed Central

    Cashion, Avery T.; Caballero, Montserrat; Halevi, Alexandra; Pappa, Andrew; Dennis, Robert G.

    2014-01-01

    Abstract A programmable bioreactor using a voice-coil actuator was developed to enable research on the effects of periodic vibratory stimulus on human and porcine mesenchymal stem cells (MSCs). We hypothesized that low frequency vibrations would result in a cartilage phenotype and higher frequency vibrations would result in a bone phenotype. The mechanical stimulation protocol is adjusted from a computer external to the incubator via a USB cable. Once programmed, the embedded microprocessor and sensor system on the bioreactor execute the protocol independent of the computer. In each test, a sinusoidal stimulus was applied to a culture plate in 1-min intervals with a 15-min rest following each, for a total of 15 h per day for 10 days. Frequencies of 1 and 100 Hz were applied to cultures of both human and porcine umbilical cord–derived MSCs. Chondrogenesis was determined by Alcian blue staining for glycosaminoglycans and an increased differentiation index (ratio of mRNA for collagen II and collagen I). Osteogenic differentiation was indicated with Alizarin red for calcium staining and increased bone morphogenetic protein 2 mRNA. One-hertz stimulation resulted in a cartilage phenotype for both human and porcine MSCs, while 100-Hz stimulation resulted in a bone phenotype. PMID:24570842

  4. Robust design of a vibratory gyroscope with an unbalanced inner torsion gimbal using axiomatic design

    NASA Astrophysics Data System (ADS)

    Hwang, Kwang-Hyeon; Lee, Kwon-Hee; Park, Gyung-Jin; Lee, Byeong-Leul; Cho, Yong-Chul; Lee, Seok-Han

    2003-01-01

    Recently, there has been considerable interest in micro gyroscopes made of silicon chips. These can be applied to many microelectromechanical systems, such as devices for stabilization, general rate control, directional pointing, autopilot systems, and missile control. A decoupled vibratory gyroscope has been fabricated and tested. In this research, design improvement is obtained from numerical analyses as well as from a theoretical design point of view. The existing design is analyzed by using the axiomatic approach, which provides a general framework for design. For axiomatic design, the functional requirements (FRs) are twofold: firstly, the natural frequencies should have fixed values, and secondly the system should be robust to large tolerances. According to the independence axiom, the design parameters (DPs) are classified into the same number of groups as the FRs. Each group of DPs is separately determined according to the sequence indicated by axiomatic design. When a group of DPs should be determined to enhance robustness, the Taguchi concept is employed to maintain robust performance regardless of the tolerances. It is noted that the Taguchi method is used as a unit process in the sequence of the axiomatic design.

  5. A novel stress distribution organ in the arthropod exoskeleton.

    PubMed

    Hecht, Emelia M; Cullinane, Dennis M; Grosse, Ian R

    2010-09-01

    The vertebrate endoskeleton possesses a massive internal network of load-distributing trabeculae that in most locations accounts for the vast majority of bone cross sectional area. In contrast, arthropods rely on the external cuticle and its intermittent outpocketings to distribute the daily stresses of physiological loading. One of the constraints of the arthropod exoskeleton is the necessity to house the musculature involved in locomotion, feeding and etc. Because of this lack of an extensive internal load-distributing trabecular network, any load-distributing mechanism in arthropods would necessarily have to incorporate the exoskeleton. Several authors have identified structural apophysi whose functions presumably have mechanical significance, but few have been identified using quantitative analyses. This study investigates a novel stress-reducing structure arising from the articulation sites in the exoskeleton of the blue crab, Callinectes sapidus. During dissection of the merus-carpus joint and leg cuticle of the blue crab, an unique system of internal strut-like members was found radiating, both longitudinally and laterally, from the articular surface of the proximal merus segment, tapering into the diaphyseal region. This strut system, an internal outpocketing of the exoskeleton and semi-circular in cross section, mirrors the trabecular pattern seen radiating from vertebrate joint surfaces. Earlier reports of this structural system described it as a muscle attachment site and made little or no reference to potential load distribution properties. Finite element analysis (FEA) models confirm the efficacy of stress distributing properties of this articular strut system in the blue crab leg. In the models, the struts significantly reduce stress concentrations, reduce localized strains and minimize the risk of failure via buckling. Models lacking this strut system generate 94.7% larger peak von Mises stress at the articulation site, 37% higher peak displacement

  6. Bioinformatic prediction of arthropod/nematode-like peptides in non-arthropod, non-nematode members of the Ecdysozoa.

    PubMed

    Christie, Andrew E; Nolan, Daniel H; Garcia, Zachery A; McCoole, Matthew D; Harmon, Sarah M; Congdon-Jones, Benjamin; Ohno, Paul; Hartline, Niko; Congdon, Clare Bates; Baer, Kevin N; Lenz, Petra H

    2011-02-01

    The Onychophora, Priapulida and Tardigrada, along with the Arthropoda, Nematoda and several other small phyla, form the superphylum Ecdysozoa. Numerous peptidomic studies have been undertaken for both the arthropods and nematodes, resulting in the identification of many peptides from each group. In contrast, little is known about the peptides used as paracrines/hormones by species from the other ecdysozoan taxa. Here, transcriptome mining and bioinformatic peptide prediction were used to identify peptides in members of the Onychophora, Priapulida and Tardigrada, the only non-arthropod, non-nematode members of the Ecdysozoa for which there are publicly accessible expressed sequence tags (ESTs). The extant ESTs for each phylum were queried using 106 arthropod/nematode peptide precursors. Transcripts encoding calcitonin-like diuretic hormone and pigment-dispersing hormone (PDH) were identified for the onychophoran Peripatopsis sedgwicki, with transcripts encoding C-type allatostatin (C-AST) and FMRFamide-like peptide identified for the priapulid Priapulus caudatus. For the Tardigrada, transcripts encoding members of the A-type allatostatin, C-AST, insect kinin, orcokinin, PDH and tachykinin-related peptide families were identified, all but one from Hypsibius dujardini (the exception being a Milnesium tardigradum orcokinin-encoding transcript). The proteins deduced from these ESTs resulted in the prediction of 48 novel peptides, six onychophoran, eight priapulid and 34 tardigrade, which are the first described from these phyla. PMID:21074533

  7. The i5K Initiative: advancing arthropod genomics for knowledge, human health, agriculture, and the environment.

    PubMed

    2013-01-01

    Insects and their arthropod relatives including mites, spiders, and crustaceans play major roles in the world's terrestrial, aquatic, and marine ecosystems. Arthropods compete with humans for food and transmit devastating diseases. They also comprise the most diverse and successful branch of metazoan evolution, with millions of extant species. Here, we describe an international effort to guide arthropod genomic efforts, from species prioritization to methodology and informatics. The 5000 arthropod genomes initiative (i5K) community met formally in 2012 to discuss a roadmap for sequencing and analyzing 5000 high-priority arthropods and is continuing this effort via pilot projects, the development of standard operating procedures, and training of students and career scientists. With university, governmental, and industry support, the i5K Consortium aspires to deliver sequences and analytical tools for each of the arthropod branches and each of the species having beneficial and negative effects on humankind. PMID:23940263

  8. The i5K Initiative: Advancing Arthropod Genomics for Knowledge, Human Health, Agriculture, and the Environment

    PubMed Central

    2013-01-01

    Insects and their arthropod relatives including mites, spiders, and crustaceans play major roles in the world’s terrestrial, aquatic, and marine ecosystems. Arthropods compete with humans for food and transmit devastating diseases. They also comprise the most diverse and successful branch of metazoan evolution, with millions of extant species. Here, we describe an international effort to guide arthropod genomic efforts, from species prioritization to methodology and informatics. The 5000 arthropod genomes initiative (i5K) community met formally in 2012 to discuss a roadmap for sequencing and analyzing 5000 high-priority arthropods and is continuing this effort via pilot projects, the development of standard operating procedures, and training of students and career scientists. With university, governmental, and industry support, the i5K Consortium aspires to deliver sequences and analytical tools for each of the arthropod branches and each of the species having beneficial and negative effects on humankind. PMID:23940263

  9. Ectomycota Associated with Arthropods from Bat Hibernacula in Eastern Canada, with Particular Reference to Pseudogymnoasucs destructans.

    PubMed

    Vanderwolf, Karen J; Malloch, David; McAlpine, Donald F

    2016-01-01

    The introduction of Pseudogymnoascus destructans (Pd) to North America, agent of white-nose syndrome in hibernating bats, has increased interest in fungi from underground habitats. While bats are assumed to be the main vector transmitting Pd cave-to-cave, the role of other fauna is unexplored. We documented the fungi associated with over-wintering arthropods in Pd-positive hibernacula, including sites where bats had been recently extirpated or near-extirpated, to determine if arthropods carried Pd, and to compare fungal assemblages on arthropods to bats. We isolated 87 fungal taxa in 64 genera from arthropods. Viable Pd was cultured from 15.3% of arthropods, most frequently from harvestmen (Nelima elegans). Fungal assemblages on arthropods were similar to those on bats. The different fungal assemblages documented among arthropods may be due to divergent patterns of movement, aggregation, feeding, or other factors. While it is unlikely that arthropods play a major role in the transmission dynamics of Pd, we demonstrate that arthropods may carry viable Pd spores and therefore have the potential to transport Pd, either naturally or anthropogenically, within or among hibernacula. This underlines the need for those entering hibernacula to observe decontamination procedures and for such procedures to evolve as our understanding of potential mechanisms of Pd dispersal improve. PMID:27110827

  10. Ectomycota Associated with Arthropods from Bat Hibernacula in Eastern Canada, with Particular Reference to Pseudogymnoascus destructans

    PubMed Central

    Vanderwolf, Karen J.; Malloch, David; McAlpine, Donald F.

    2016-01-01

    The introduction of Pseudogymnoascus destructans (Pd) to North America, agent of white-nose syndrome in hibernating bats, has increased interest in fungi from underground habitats. While bats are assumed to be the main vector transmitting Pd cave-to-cave, the role of other fauna is unexplored. We documented the fungi associated with over-wintering arthropods in Pd-positive hibernacula, including sites where bats had been recently extirpated or near-extirpated, to determine if arthropods carried Pd, and to compare fungal assemblages on arthropods to bats. We isolated 87 fungal taxa in 64 genera from arthropods. Viable Pd was cultured from 15.3% of arthropods, most frequently from harvestmen (Nelima elegans). Fungal assemblages on arthropods were similar to those on bats. The different fungal assemblages documented among arthropods may be due to divergent patterns of movement, aggregation, feeding, or other factors. While it is unlikely that arthropods play a major role in the transmission dynamics of Pd, we demonstrate that arthropods may carry viable Pd spores and therefore have the potential to transport Pd, either naturally or anthropogenically, within or among hibernacula. This underlines the need for those entering hibernacula to observe decontamination procedures and for such procedures to evolve as our understanding of potential mechanisms of Pd dispersal improve. PMID:27110827

  11. Arthropods of the great indoors: characterizing diversity inside urban and suburban homes

    PubMed Central

    Leong, Misha; Bayless, Keith M.; Malow, Tara L.F.; Dunn, Robert R.; Trautwein, Michelle D.

    2016-01-01

    Although humans and arthropods have been living and evolving together for all of our history, we know very little about the arthropods we share our homes with apart from major pest groups. Here we surveyed, for the first time, the complete arthropod fauna of the indoor biome in 50 houses (located in and around Raleigh, North Carolina, USA). We discovered high diversity, with a conservative estimate range of 32–211 morphospecies, and 24–128 distinct arthropod families per house. The majority of this indoor diversity (73%) was made up of true flies (Diptera), spiders (Araneae), beetles (Coleoptera), and wasps and kin (Hymenoptera, especially ants: Formicidae). Much of the arthropod diversity within houses did not consist of synanthropic species, but instead included arthropods that were filtered from the surrounding landscape. As such, common pest species were found less frequently than benign species. Some of the most frequently found arthropods in houses, such as gall midges (Cecidomyiidae) and book lice (Liposcelididae), are unfamiliar to the general public despite their ubiquity. These findings present a new understanding of the diversity, prevalence, and distribution of the arthropods in our daily lives. Considering their impact as household pests, disease vectors, generators of allergens, and facilitators of the indoor microbiome, advancing our knowledge of the ecology and evolution of arthropods in homes has major economic and human health implications. PMID:26819844

  12. Geographic patterns of ground-dwelling arthropods across an ecoregional transition in the north American Southwest

    USGS Publications Warehouse

    Lightfoot, D.C.; Brantley, S.L.; Allen, C.D.

    2008-01-01

    We examined the biogeographic patterns of ground-dwelling arthropod communities across a heterogeneous semiarid region of the Southern Rio Grande Rift Valley of New Mexico. Our 3 sites included portions of 5 ecoregions, with the middle site a transition area where all ecoregions converged. We addressed the following 3 questions: (1) Do the species assemblage patterns for ground arthropods across habitats and sites conform to recognized ecoregions? (2) Are arthropod assemblages in distinct vegetation-defined habitats within an ecoregion more similar to each other or to assemblages in similar vegetation-defined habitats in other ecoregions? (3) Is there a detectable edge effect with increased arthropod diversity in the area of converging ecoregions? We encountered 442 target arthropod species from pitfall traps operating continuously for 7 years over a series of different habitats at each of the 3 sites. We examined geographic distributions of spider and cricket/grasshopper species in detail, and they showed affinities for different ecoregions, respectively. Each habitat within a study site supported a unique overall arthropod assemblage; nevertheless, different habitats at the same site were more similar to each other than they were to similar habitats at other sites. Overall arthropod species richness was greatest in the area where all 5 ecoregions converged. Arthropod species and their geographic distributions are poorly known relative to vascular plants and vertebrate animals. Findings from this research indicate that ecoregional classification is a useful tool for understanding biogeographic patterns among arthropods.

  13. Angular circulation speed of tablets in a vibratory tablet coating pan.

    PubMed

    Kumar, Rahul; Wassgren, Carl

    2013-03-01

    In this work, a single tablet model and a discrete element method (DEM) computer simulation are developed to obtain the angular circulation speed of tablets in a vibratory tablet coating pan for range of vibration frequencies and amplitudes. The models identify three important dimensionless parameters that influence the speed of the tablets: the dimensionless amplitude ratio (a/R), the Froude number (aω2/g), and the tablet-wall friction coefficient, where a is the peak vibration amplitude at the drum center, ω is the vibration angular frequency, R is the drum radius, and g is the acceleration due to gravity. The models predict that the angular circulation speed of tablets increases with an increase in each of these parameters. The rate of increase in the angular circulation speed is observed to decrease for larger values of a/R. The angular circulation speed reaches an asymptote beyond a tablet-wall friction coefficient value of about 0.4. Furthermore, it is found that the Froude number should be greater than one for the tablets to start circulating. The angular circulation speed increases as Froude number increases but then does not change significantly at larger values of the Froude number. Period doubling, where the motion of the bed is repeated every two cycles, occurs at a Froude number larger than five. The single tablet model, although much simpler than the DEM model, is able to predict the maximum circulation speed (the limiting case for a large value of tablet-wall friction coefficient) as well as the transition to period doubling. PMID:23325382

  14. Relative performance of a vibratory energy harvester in mono- and bi-stable potentials

    NASA Astrophysics Data System (ADS)

    Masana, Ravindra; Daqaq, Mohammed F.

    2011-11-01

    Motivated by the need for broadband vibratory energy harvesting, many research studies have recently proposed energy harvesters with nonlinear characteristics. Based on the shape of their potential function, such devices are classified as either mono- or bi-stable energy harvesters. This paper aims to investigate the relative performance of these two classes under similar excitations and electric loading conditions. To achieve this goal, an energy harvester consisting of a clamped-clamped piezoelectric beam bi-morph is considered. The shape of the harvester's potential function is altered by applying a static compressive axial load at one end of the beam. This permits operation in the mono-stable (pre-buckling) and bi-stable (post-buckling) configurations. For the purpose of performance comparison, the axial load is used to tune the harvester's oscillation frequencies around the static equilibria such that they have equal values in the mono- and bi-stable configurations. The harvester is subjected to harmonic base excitations of different magnitudes and a slowly varying frequency spanning a wide band around the tuned oscillation frequency. The output voltage measured across a purely resistive load is compared over the frequency range considered. Two cases are discussed; the first compares the performance when the bi-stable harvester has deep potential wells, while the second treats a bi-stable harvester with shallow wells. Both numerical and experimental results demonstrate the essential role that the potential shape plays in conjunction with the base acceleration to determine whether the bi-stable harvester can outperform the mono-stable one and for what range of frequencies. Results also illustrate that, for a bi-stable harvester with shallow potential wells, super-harmonic resonances can activate the inter-well dynamics even for a small base acceleration, thereby producing large voltages in the low frequency range.

  15. Transient response and stability of the AGC-PI closed-loop controlled MEMS vibratory gyroscopes

    NASA Astrophysics Data System (ADS)

    Cui, J.; Chi, X. Z.; Ding, H. T.; Lin, L. T.; Yang, Z. C.; Yan, G. Z.

    2009-12-01

    This paper presents a detailed study on the transient response and stability of the automatic gain control (AGC) with a proportion-integral (PI) controller for a MEMS vibratory gyroscope, which constructs a closed-loop control system to make the gyroscope achieve a constant amplitude vibration at its resonant frequency. The nonlinear mathematical model for the control system is established by applying the averaging and linearization method, which is evaluated through numerical simulations. The stability and convergence characteristics of the whole loop are investigated by using the phase plane method and Routh-Hurwitz criterion. The analysis provides a quantitative methodology for selecting the system parameters to approach stability and an optimal transient response. The negative impact induced by drift of the resonant frequency and Q-factor is also discussed. Simulation results predicted by the model are shown to be in close agreement with the experimental results carried out on a doubly decoupled bulk micromachined gyroscope. By optimizing the control parameters, the measured rising time is less than 100 ms without obvious overshoot. The setting time of the whole loop is less than 200 ms with the relative fluctuation of velocity amplitude within approximately 16 ppm for an hour. The resulting overall performance of the gyroscope is tested under atmospheric pressure. The resonant frequencies and the Q-factor of the drive mode and sense mode are 2.986 kHz, 213 and 3.199 kHz, 233, respectively. The gyroscope achieves a scale factor of 27.6 mV/deg/s with nonlinearity less than 120 ppm in the full-scale range of 800° s-1. The threshold of sensitivity is measured to be about 0.005° s-1 with noise equivalent angular rate evaluated to be 0.001°/s/Hz1/2.

  16. Waptia and the Diversification of Brood Care in Early Arthropods.

    PubMed

    Caron, Jean-Bernard; Vannier, Jean

    2016-01-11

    Brood care, including the carrying of eggs or juveniles, is a form of parental care, which, like other parental traits [1], enhances offspring fitness with variable costs and benefits to the parents [2]. Attempts to understand why and how parental care evolved independently in numerous animal groups often emphasize the role of environmental pressures such as predation, ephemeral resources, and, more generally, the harshness of environment. The fossil record can, in principle, provide minimum age constraints on the evolution of life-history traits, including brood care and key information on the reproductive strategies of extinct organisms. New, exceptionally preserved specimens of the weakly sclerotized arthropod Waptia fieldensis from the middle Cambrian (ca. 508 million years ago) Burgess Shale, Canada, provide the oldest example of in situ eggs with preserved embryos in the fossil record. The relatively small clutch size, up to 24 eggs, and the relatively large diameter of individual eggs, some over 2 mm, contrast with the high number of small eggs-found without preserved embryos-in the bivalved bradoriid arthropod Kunmingella douvillei from the Chengjiang biota (ca. 515 million years ago). The presence of these two different parental strategies suggests a rapid evolution of a variety of modern-type life-history traits, including extended investment in offspring survivorship, soon after the Cambrian emergence of animals. Together with previously described brooded eggs in ostracods from the Upper Ordovician (ca. 450 million years ago), these new findings suggest that the presence of a bivalved carapace played a key role in the early evolution of parental care in arthropods. PMID:26711492

  17. Arthropod phylogeny revisited, with a focus on crustacean relationships.

    PubMed

    Koenemann, Stefan; Jenner, Ronald A; Hoenemann, Mario; Stemme, Torben; von Reumont, Björn M

    2010-01-01

    Higher-level arthropod phylogenetics is an intensely active field of research, not least as a result of the hegemony of molecular data. However, not all areas of arthropod phylogenetics have so far received equal attention. The application of molecular data to infer a comprehensive phylogeny of Crustacea is still in its infancy, and several emerging results are conspicuously at odds with morphology-based studies. In this study, we present a series of molecular phylogenetic analyses of 88 arthropods, including 57 crustaceans, representing all the major lineages, with Onychophora and Tardigrada as outgroups. Our analyses are based on published and new sequences for two mitochondrial markers, 16S rDNA and cytochrome c oxidase subunit I (COI), and the nuclear ribosomal gene 18S rDNA. We designed our phylogenetic analyses to assess the effects of different strategies of sequence alignment, alignment masking, nucleotide coding, and model settings. Our comparisons show that alignment optimization of ribosomal markers based on secondary structure information can have a radical impact on phylogenetic reconstruction. Trees based on optimized alignments recover monophyletic Arthropoda (excluding Onychophora), Pancrustacea, Malacostraca, Insecta, Myriapoda and Chelicerata, while Maxillopoda and Hexapoda emerge as paraphyletic groups. Our results are unable to resolve the highest-level relationships within Arthropoda, and none of our trees supports the monophyly of Myriochelata or Mandibulata. We discuss our results in the context of both the methodological variations between different analyses, and of recently proposed phylogenetic hypotheses. This article offers a preliminary attempt to incorporate the large diversity of crustaceans into a single molecular phylogenetic analysis, assessing the robustness of phylogenetic relationships under varying analysis parameters. It throws into sharp relief the relative strengths and shortcomings of the combined molecular data for

  18. Interactions among predators and the cascading effects of vertebrate insectivores on arthropod communities and plants.

    PubMed

    Mooney, Kailen A; Gruner, Daniel S; Barber, Nicholas A; Van Bael, Sunshine A; Philpott, Stacy M; Greenberg, Russell

    2010-04-20

    Theory on trophic interactions predicts that predators increase plant biomass by feeding on herbivores, an indirect interaction called a trophic cascade. Theory also predicts that predators feeding on predators, or intraguild predation, will weaken trophic cascades. Although past syntheses have confirmed cascading effects of terrestrial arthropod predators, we lack a comprehensive analysis for vertebrate insectivores-which by virtue of their body size and feeding habits are often top predators in these systems-and of how intraguild predation mediates trophic cascade strength. We report here on a meta-analysis of 113 experiments documenting the effects of insectivorous birds, bats, or lizards on predaceous arthropods, herbivorous arthropods, and plants. Although vertebrate insectivores fed as intraguild predators, strongly reducing predaceous arthropods (38%), they nevertheless suppressed herbivores (39%), indirectly reduced plant damage (40%), and increased plant biomass (14%). Furthermore, effects of vertebrate insectivores on predatory and herbivorous arthropods were positively correlated. Effects were strongest on arthropods and plants in communities with abundant predaceous arthropods and strong intraguild predation, but weak in communities depauperate in arthropod predators and intraguild predation. The naturally occurring ratio of arthropod predators relative to herbivores varied tremendously among the studied communities, and the skew to predators increased with site primary productivity and in trees relative to shrubs. Although intraguild predation among arthropod predators has been shown to weaken herbivore suppression, we find this paradigm does not extend to vertebrate insectivores in these communities. Instead, vertebrate intraguild preda-tion is associated with strengthened trophic cascades, and insectivores function as dominant predators in terrestrial plant-arthropod communities. PMID:20368418

  19. The relationships between residual stress relaxation and texture development in AZ31 Mg alloys via the vibratory stress relief technique

    SciTech Connect

    Wang, Jia-Siang; Hsieh, Chih-Chun; Lai, Hsuan-Han; Kuo, Che-Wei; Wu, Paxon Ti-Yuan; Wu, Weite

    2015-01-15

    A systematic study of residual stress relaxation and the texture evolution of cold-rolled AZ31 Mg alloys using the vibratory stress relief technique with a simple cantilever beam vibration system was performed using a high-resolution X-ray diffractometer and a portable X-ray residual stress analyzer. The effects of vibrational stress excitation on the surface residual stress distribution and on the texture of pole figures (0002) occurring during the vibratory stress relief were examined. Compared with the effects corresponding to the same alloy under non-vibration condition, it can be observed that the uniform surface residual stress distribution and relaxation of the compressive residual stress in the stress concentration zone were observed rather than all of the residual stresses being eliminated. Furthermore, with an increase in the vibrational aging time, the compressive residual stress, texture density, and (0002) preferred orientation increased first and then decreased. It should be underlined that the vibratory stress relief process for the vibrational aging time of more than 10 min is able to weaken the strong basal textures of AZ31 Mg alloys, which is valuable for enhancement of their formability and is responsible for an almost perfect 3D-Debye–Scherrer ring. - Highlights: • 3D-Debye ring about VSR technique is not discussed in the existing literature. • A newly developed VSR method is suitable for small or thin workpieces. • The cosα method accurately and effectively determines the residual stresses. • The VSR technique is valuable for enhancement of their formability. • The texture and preferred orientation change with the vibrational aging time.

  20. The Arthropod-Borne Animal Diseases Research Laboratory: Research Program Update and Current Status

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mission of the Arthropod-Borne Animal Diseases Research Laboratory (ABADRL) located in Laramie, Wyoming, is to solve major endemic, emerging, and exotic arthropod-borne disease problems in U.S. livestock. The ABADRL has three 5-year project plans under two ARS National Research Programs; Animal ...

  1. "Bugs on Bugs": An Inquiry-Based, Collaborative Activity to Learn Arthropod & Microbial Biodiversity

    ERIC Educational Resources Information Center

    Lampert, Evan C.; Morgan, Jeanelle M.

    2015-01-01

    Diverse communities of arthropods and microbes provide humans with essential ecosystem goods and services. Arthropods are the most diverse and abundant macroscopic animals on the planet, and many remain to be discovered. Much less is known about microbial diversity, despite their importance as free-living species and as symbionts. We created…

  2. Genetic Variation in Functional Traits Influences Arthropod Community Composition in Aspen (Populus tremula L.)

    PubMed Central

    Robinson, Kathryn M.; Ingvarsson, Pär K.; Jansson, Stefan; Albrectsen, Benedicte R.

    2012-01-01

    We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp) collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores. PMID:22662190

  3. Avirulence effector discovery in a plant galling and plant parasitic arthropod, the Hessian fly (Mayetiola destructor)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly specialized obligate plant-parasites exist within several groups of arthropods (insects and mites). Many of these are important pests, but the molecular basis of their parasitism and its evolution are poorly understood. One hypothesis is that plant parasitic arthropods use effector proteins...

  4. The Arthropod-borne Animal Diseases Unit: research program update and status

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To accomplish the continuing research mission of the Arthropod Borne Animal Diseases Unit (ABADRU) in solving major endemic, emerging, and exotic arthropod-borne disease problems in livestock, the Unit has completed the move to Manhattan, KS. The ABADRU is one of five units at the Center for Grain a...

  5. Arthropods in no-tillage soybean agroecosystems: Community composition and ecosystem interactions

    NASA Astrophysics Data System (ADS)

    House, Garfield J.; Stinner, Benjamin R.

    1983-01-01

    Sampling data are provided and concepts discussed regarding soil and foliage arthropod communities in conventional and no-tillage soybean agroecosystems Soil arthropod communities from the two cropping systems were also compared with that from an adjacent old field. Biweekly arthropod samples were collected from conventional, no-tillage, and old-field systems Soil arthropods were sampled by quadrat and pitfall trap methods, foliage arthropods were collected by sweep net Quadrat sampling revealed that ground beetle number, species diversity, and biomass were significantly higher ( P<0.05) in no-tillage than in conventional tillage systems. Pitfall trap data indicated higher densities and species diversity for most major soil macro-arthropod guilds Foliage arthropod guilds from no-tillage treatments showed higher species diversity throughout the growing season than those of conventional tillage, possibly because of greater structural diversity provided by weeds and litter in notillage systems No-tillage systems supported a larger and more diverse arthropod community than conventionally grown soybeans, suggesting a need for pest management strategies that simultaneously consider many variables. Both foliar grazing and leaf nitrogen content were higher in conventional than in no-tillage systems, indicating a possible causal connection between soil tillage and insect herbivory rates

  6. LONG-PCR AS A TOOL FOR DETECTING REARRANGEMENTS OF ARTHROPOD MTDNA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rearrangements of the mitochondrial DNA gene order have been used to help define the pattern of evolutionary divergence in arthropod taxa. We have employed a combination of highly conserved insect-based PCR primers with long-PCR to survey fourteen non-insect arthropods for mitochondrial gene rearra...

  7. The effects of ingested mammalian blood factors on vector arthropod immunity and physiology

    PubMed Central

    Pakpour, Nazzy; Akman-Anderson, Leyla; Vodovotz, Yoram; Luckhart, Shirley

    2013-01-01

    The blood feeding behavior of disease-transmitting arthropods creates a unique intersection between vertebrate and invertebrate physiology. Here, we review host blood-derived factors that persist through blood digestion to affect the lifespan, reproduction, and immune responses of some of the most common arthropod vectors of human disease. PMID:23370408

  8. The i5K Initiative: Advancing arthropod genomics for knowledge, human health, agriculture, and the environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insects and their arthropod relatives including mites, spiders, and crustaceans, play major roles in the world’s terrestrial, aquatic, and marine ecosystems. Arthropods compete with humans for food and transmit devastating diseases. They also comprise the most diverse and successful branch of metazo...

  9. Procedures for identification of arthropod-borne viruses*

    PubMed Central

    Casals, Jordi

    1961-01-01

    Owing to the existence of antigenic groups and to the consequent characteristics of the immune response of a host to grouped viruses, certain logical steps are advisable in the process of identification of an arthropod-borne (arbor) virus. The first of these steps is the determination of the arthropod-borne nature of the virus. Since no antigenic property is known to be common to all arbor viruses, the decision is based on other biological properties and on the circumstances of isolation. The second step is determination of the antigenic group. For this are used hyperimmune sera with considerable cross-reactivity within the group, as well as the test that gives the most overlap. The third step is determination of type within the group. Simple immune sera and the least cross-reactive test are used at this step. Viruses that belong in minor groups or are ungrouped often constitute a big problem owing to the fact that, once the major groups have been eliminated from further consideration, comparative studies must be conducted with practically all the remaining viruses before a definitive answer is reached. PMID:13691234

  10. Early History of Arthropod and Vascular Plant Associations

    NASA Astrophysics Data System (ADS)

    Labandeira, Conrad C.

    Although research on modern plant-arthropod associations is one of the cornerstones of biodiversity studies, very little of that interest has percolated down to the fossil record. Much of this neglect is attributable to dismissal of Paleozoic plant-arthropod interactions as being dominated by detritivory, with substantive herbivory not emerging until the Mesozoic. Recent examination of associations from some of the earliest terrestrial communities indicates that herbivory probably extends to the Early Devonian, in the form of spore feeding and piercing-and-sucking. External feeding on pinnule margins and the intimate and intricate association of galling are documented from the Middle and Late Pennsylvanian, respectively. During the Early Permian, the range of external foliage feeding extended to hole feeding and skeletonization and was characterized by the preferential targeting of certain seed plants. At the close of the Paleozoic, surface fluid feeding was established, but there is inconclusive evidence for mutualistic relationships between insect pollinivores and seed plants. These data are gleaned from the largely separate trace-fossil records of gut contents, coprolites, and plant damage and the body-fossil records of plant reproductive and vegetative structures, insect mouthparts, and ovipositors. While these discoveries accentuate the potential for identifying particular associations, the greatest theoretical demand is to establish the spectrum and level of intensity for the emergence of insect herbivory in a range of environments during the Pennsylvanian and Permian.

  11. [Arthropod community structures in transgenic Bt cotton fields].

    PubMed

    Wei, G; Cui, L; Zhang, X; Liu, S; Lü, N; Zhang, Q

    2001-08-01

    Arthropod community structures were investigated in transgenic Bt cultivars, Bollgard(B) and Chinese cotton 30 (CC30), and common cultivars, control (C) and no control (NC) cotton field in North China in 1998. The results showed that compared with common cultivars, the species richness and the number of total individual of arthropod community in transgenic Bt cultivars field were reduced 2.4-16.3% and 71.0-78.3% respectively, in which dominant species in phytophagous subcommunity varied. The number of individual of predatory and parastic subcommunity were all increased. The similarity coefficient between CC30 and NC was 0.8243, B and NC 0.7320, B and C 0.3380, C and NC 0.3128, CC30 and C 0.2665. The order of diversity and evenness value of these were CC30 (2.3712 and 0.6428), NC (2.3654 and 0.6251), B (2.1364 and 0.5791), and C (1.0877 and 0.2949), their dominant value was 0.8726 (C), 0.3528(B), 0.1178(NC) and 0.1048 (CC30) respectively. It was concluded that different integrated pest management (IPM) strategy should be implemented in transgenic Bt cotton instead of common variety cotton field. PMID:11758387

  12. Technique for studying arthropod and microbial communities within tree tissues.

    PubMed

    Aflitto, Nicholas C; Hofstetter, Richard W; McGuire, Reagan; Dunn, David D; Potter, Kristen A

    2014-01-01

    Phloem tissues of pine are habitats for many thousands of organisms. Arthropods and microbes use phloem and cambium tissues to seek mates, lay eggs, rear young, feed, or hide from natural enemies or harsh environmental conditions outside of the tree. Organisms that persist within the phloem habitat are difficult to observe given their location under bark. We provide a technique to preserve intact phloem and prepare it for experimentation with invertebrates and microorganisms. The apparatus is called a 'phloem sandwich' and allows for the introduction and observation of arthropods, microbes, and other organisms. This technique has resulted in a better understanding of the feeding behaviors, life-history traits, reproduction, development, and interactions of organisms within tree phloem. The strengths of this technique include the use of inexpensive materials, variability in sandwich size, flexibility to re-open the sandwich or introduce multiple organisms through drilled holes, and the preservation and maintenance of phloem integrity. The phloem sandwich is an excellent educational tool for scientific discovery in both K-12 science courses and university research laboratories. PMID:25489987

  13. [Natural concentration of antimalaric components in Tropical arthropods (in vitro)].

    PubMed

    Chinchilla-Carmona, Misael; Guerrero Bermúdez, Olga Marta; Tamayo-Castillo, Giselle; Appel, Ana Sittenfeld; Jiménez-Somarribas, Alberto; Valerio-Campos, Idalia

    2008-06-01

    Alcohol, hexane and dichlorometane extracts of 751 samples of Costa Rican arthropods were studied for the presence of antimalaric components. With Plasmodium berghei we set an in vitro model in which the effect of the extract was determined by staining of the parasites with cresil brilliant blue. Active extracts at concentration of 50 mg or less, were considered positive. Promissory extracts were found in the orders Lepidoptera (24.1%), Coleoptera (32.8%), Hemiptera (38.5%) and Polydesmida (81.3%). Since most of the Lepidoptera samples were in the immature stages, the relation with the host plant was analyzed. Cannaceae, Flacourtiaceae, Crisobalanaceae, Lauraceae, Fagaceae, Ulmaceae, Rosaceae, Asteraceae, Rubiaceae, Lauraceae and Caprifoliaceae were related with the Lepidoptera larvae, and an antimalaric effect has been reported in most of these families. In the orders Polydesmida, Opiliones and Blattodea, the extract from adults also had some important effect, probably because all of them fed on plants. Polydesmida and Opiliones have chemical substances that probably serve as defensive purposes; these chemicals could also have some antiparasitic effect. Therefore, the detection of antimalaric components in arthropod species led to the identification of plants with promissory antimalaric components. PMID:19256421

  14. Introduction to the Arizona Sky Island Arthropod Project (ASAP): Systematics, Biogeography, Ecology, and Population Genetics of Arthropods of the Madrean Sky Islands

    PubMed Central

    Moore, Wendy; Meyer, Wallace M.; Eble, Jeffrey A.; Franklin, Kimberly; Wiens, John F.; Brusca, Richard C.

    2014-01-01

    The Arizona Sky Island Arthropod Project (ASAP) is a new multi-disciplinary research program at the University of Arizona that combines systematics, biogeography, ecology, and population genetics to study origins and patterns of arthropod diversity along elevation gradients and among mountain ranges in the Madrean Sky Island Region. Arthropods represent taxonomically and ecologically diverse organisms that drive key ecosystem processes in this mountain archipelago. Using data from museum specimens and specimens we obtain during long-term collecting and monitoring programs, ASAP will document arthropod species across Arizona's Sky Islands to address a number of fundamental questions about arthropods of this region. Baseline data will be used to determine climatic boundaries for target species, which will then be integrated with climatological models to predict future changes in arthropod communities and distributions in the wake of rapid climate change. ASAP also makes use of the natural laboratory provided by the Sky Islands to investigate ecological and genetic factors that influence diversification and patterns of community assembly. Here, we introduce the project, outline overarching goals, and describe preliminary data from the first year of sampling ground-dwelling beetles and ants in the Santa Catalina Mountains. PMID:25505938

  15. Fluctuating Wall Pressure and Vibratory Response of a Cylindrical Elastic Shell due to Confined Jet Excitations.

    NASA Astrophysics Data System (ADS)

    Ng, Kam Wing

    A theoretical and experimental study was conducted to investigate the flow-induced noise and vibration caused by confined jet flows in a cylindrical duct. Unrestricted pipe flow and flows restricted by various orifices were tested for a wide range of velocities to simulate the flow in piping systems. Wall pressure data showed that the noise levels vary with the pipe's axial location and the peak noise is located at the vicinity of the end of the jet potential core. A non-dimensional wall pressure spectrum was established for the various confined jets by the Strouhal relationship, where the length scale is the jet hydraulic diameter. This jet pressure spectrum agrees with the wall pressure spectrum of a turbulent boundary layer above a rigid plane. Correlations of wall pressure fluctuations and pipe wall acceleration signals showed that jet flows generate more deterministic features than pipe flow. The coherence functions of the wall pressure and pipe wall acceleration signals are relatively high near the exit of the jet. The high coherence is probably due to the large-scale coherent structures. An analytical model was developed to study the effect of the turbulent jet flow field on the wall pressure and vibratory motion of the duct wall. Based on flow field measurements, the blocked surface pressure was calculated using Lighthill's method, and then used to drive the fluid -filled shell. The wall pressure and pipe wall acceleration were determined by solving the coupled fluid solid interaction problem. The wall pressure was obtained by summing the blocked surface pressure and the pressure due to the wall vibration. An amplitude modulated convecting wave field was used to simulate the moving acoustic sources of the jet. The random nature of the turbulent jet was incorporated into the analytical model. Specifically, the acoustic pressure was assumed to result from hydrodynamic pressure fluctuations which are uncorrelated in the radial direction, but are correlated in

  16. Arthropod Distribution in a Tropical Rainforest: Tackling a Four Dimensional Puzzle

    PubMed Central

    Basset, Yves; Cizek, Lukas; Cuénoud, Philippe; Didham, Raphael K.; Novotny, Vojtech; Ødegaard, Frode; Roslin, Tomas; Tishechkin, Alexey K.; Schmidl, Jürgen; Winchester, Neville N.; Roubik, David W.; Aberlenc, Henri-Pierre; Bail, Johannes; Barrios, Héctor; Bridle, Jonathan R.; Castaño-Meneses, Gabriela; Corbara, Bruno; Curletti, Gianfranco; Duarte da Rocha, Wesley; De Bakker, Domir; Delabie, Jacques H. C.; Dejean, Alain; Fagan, Laura L.; Floren, Andreas; Kitching, Roger L.; Medianero, Enrique; Gama de Oliveira, Evandro; Orivel, Jérôme; Pollet, Marc; Rapp, Mathieu; Ribeiro, Sérvio P.; Roisin, Yves; Schmidt, Jesper B.; Sørensen, Line; Lewinsohn, Thomas M.; Leponce, Maurice

    2015-01-01

    Quantifying the spatio-temporal distribution of arthropods in tropical rainforests represents a first step towards scrutinizing the global distribution of biodiversity on Earth. To date most studies have focused on narrow taxonomic groups or lack a design that allows partitioning of the components of diversity. Here, we consider an exceptionally large dataset (113,952 individuals representing 5,858 species), obtained from the San Lorenzo forest in Panama, where the phylogenetic breadth of arthropod taxa was surveyed using 14 protocols targeting the soil, litter, understory, lower and upper canopy habitats, replicated across seasons in 2003 and 2004. This dataset is used to explore the relative influence of horizontal, vertical and seasonal drivers of arthropod distribution in this forest. We considered arthropod abundance, observed and estimated species richness, additive decomposition of species richness, multiplicative partitioning of species diversity, variation in species composition, species turnover and guild structure as components of diversity. At the scale of our study (2km of distance, 40m in height and 400 days), the effects related to the vertical and seasonal dimensions were most important. Most adult arthropods were collected from the soil/litter or the upper canopy and species richness was highest in the canopy. We compared the distribution of arthropods and trees within our study system. Effects related to the seasonal dimension were stronger for arthropods than for trees. We conclude that: (1) models of beta diversity developed for tropical trees are unlikely to be applicable to tropical arthropods; (2) it is imperative that estimates of global biodiversity derived from mass collecting of arthropods in tropical rainforests embrace the strong vertical and seasonal partitioning observed here; and (3) given the high species turnover observed between seasons, global climate change may have severe consequences for rainforest arthropods. PMID:26633187

  17. Arthropod Distribution in a Tropical Rainforest: Tackling a Four Dimensional Puzzle.

    PubMed

    Basset, Yves; Cizek, Lukas; Cuénoud, Philippe; Didham, Raphael K; Novotny, Vojtech; Ødegaard, Frode; Roslin, Tomas; Tishechkin, Alexey K; Schmidl, Jürgen; Winchester, Neville N; Roubik, David W; Aberlenc, Henri-Pierre; Bail, Johannes; Barrios, Héctor; Bridle, Jonathan R; Castaño-Meneses, Gabriela; Corbara, Bruno; Curletti, Gianfranco; Duarte da Rocha, Wesley; De Bakker, Domir; Delabie, Jacques H C; Dejean, Alain; Fagan, Laura L; Floren, Andreas; Kitching, Roger L; Medianero, Enrique; Gama de Oliveira, Evandro; Orivel, Jérôme; Pollet, Marc; Rapp, Mathieu; Ribeiro, Sérvio P; Roisin, Yves; Schmidt, Jesper B; Sørensen, Line; Lewinsohn, Thomas M; Leponce, Maurice

    2015-01-01

    Quantifying the spatio-temporal distribution of arthropods in tropical rainforests represents a first step towards scrutinizing the global distribution of biodiversity on Earth. To date most studies have focused on narrow taxonomic groups or lack a design that allows partitioning of the components of diversity. Here, we consider an exceptionally large dataset (113,952 individuals representing 5,858 species), obtained from the San Lorenzo forest in Panama, where the phylogenetic breadth of arthropod taxa was surveyed using 14 protocols targeting the soil, litter, understory, lower and upper canopy habitats, replicated across seasons in 2003 and 2004. This dataset is used to explore the relative influence of horizontal, vertical and seasonal drivers of arthropod distribution in this forest. We considered arthropod abundance, observed and estimated species richness, additive decomposition of species richness, multiplicative partitioning of species diversity, variation in species composition, species turnover and guild structure as components of diversity. At the scale of our study (2 km of distance, 40 m in height and 400 days), the effects related to the vertical and seasonal dimensions were most important. Most adult arthropods were collected from the soil/litter or the upper canopy and species richness was highest in the canopy. We compared the distribution of arthropods and trees within our study system. Effects related to the seasonal dimension were stronger for arthropods than for trees. We conclude that: (1) models of beta diversity developed for tropical trees are unlikely to be applicable to tropical arthropods; (2) it is imperative that estimates of global biodiversity derived from mass collecting of arthropods in tropical rainforests embrace the strong vertical and seasonal partitioning observed here; and (3) given the high species turnover observed between seasons, global climate change may have severe consequences for rainforest arthropods. PMID:26633187

  18. Frequency Split Elimination Method for a Solid-State Vibratory Angular Rate Gyro with an Imperfect Axisymmetric-Shell Resonator

    PubMed Central

    Lin, Zhen; Fu, Mengyin; Deng, Zhihong; Liu, Ning; Liu, Hong

    2015-01-01

    The resonator of a solid-state vibratory gyro is responsible for sensing angular motion. Frequency splitting of an axisymmetric-shell resonator is a common problem caused by manufacturing defects. The defect causes a frequency difference between two working modes which consist of two nodes and two antinodes. The difference leads to the loss of gyroscopic effect, and thus the resonator cannot sense angular motion. In this paper, the resonator based on an axisymmetric multi-curved surface shell structure is investigated and an approach to eliminate frequency splits is proposed. Since axisymmetric multi-curved surface shell resonators are too complex to be modeled, this paper proposes a simplified model by focusing on a common property of the axisymmetric shell. The resonator with stochastic imperfections is made equivalent to a perfect shell with an imperfect mass point. Rayleigh's energy method is used in the theoretical analysis. Finite element modeling is used to demonstrate the effectiveness of the elimination approach. In real cases, a resonator's frequency split is eliminated by the proposed approach. In this paper, errors in the theoretical analysis are discussed and steps to be taken when the deviation between assumptions and the real situation is large are figured out. The resonator has good performance after processing. The elimination approach can be applied to any kind of solid-state vibratory gyro resonators with an axisymmetric shell structure. PMID:25648707

  19. Finite Element Method Simulation of Double-Ended Tuning-Fork Quartz Resonator for Application to Vibratory Gyro-Sensor

    NASA Astrophysics Data System (ADS)

    Sato, Kenji; Ono, Atsushi; Tomikawa, Yoshiro

    2003-05-01

    In the present paper, we propose a double-ended tuning-fork quartz resonator for a flatly supported vibratory gyro-sensor in parallel with its rotating plane. The resonator has the advantages of ease of miniaturization and high resistance to external shock, because the height of the proposed resonator is less than that of the conventional vertical-type tuning-fork. In addition, the proposed resonator has two end-support parts. The resonator also has the following features: (1) the vibration energy of the resonator is trapped in the driving part, therefore the resonator is only slightly affected by the support parts and (2) unwanted output signals can be removed by differential connection of the output signals from two symmetric detection electrodes. The resonator was designed using the finite element method (FEM), and its characteristics were also simulated by FEM. The obtained results show that the double-ended tuning-fork quartz resonator is applicable as a vibratory gyro-sensor, and the I/O voltage ratio of the gyro-sensor was found to be proportional to the applied angular velocity. That is, we clarified that the double-ended tuning-fork quartz resonator could be used as a gyro-sensor.

  20. Sperm retrieval in anejaculatory diabetic men who failed in drug treatment and penile vibratory stimulation during blood sugar under control.

    PubMed

    Lu, S; Cui, Y; Li, X; Zhang, H; Hu, J; Liu, J; Chen, Z-J

    2014-05-01

    Ejaculatory dysfunction is an uncommon cause of male infertility. The aim of this study was to explore non-invasive methods for sperm retrieval in anejaculatory diabetic men who failed in drug treatment and penile vibratory stimulation during blood sugar under control. Among 21 anejaculatory diabetic men who had failed in drug treatment and penile vibratory stimulation, sperm was collected by retrograde ejaculation in 10 patients (group A), and in eight patients, sperm was collected by prostatic massage (group B). We compared the outcome of subsequent assisted reproductive treatment between the two groups; the rate of fertility in group A and in group B was 78.3% and 66.6% respectively, and the rate of good embryo was 56.6% and 48.8% respectively. Eight singleton pregnancies were achieved in the 18 anejaculatory diabetic men, 5 in group A and 3 in group B, the rate of pregnancy between the two groups was 50% and 37.5% respectively. There was no significant difference in the rate of fertility, good embryo rate and pregnancy outcome between the two groups. PMID:23488950

  1. Arthropods and associated arthropod-borne diseases transmitted by migrating birds. The case of ticks and tick-borne pathogens.

    PubMed

    Sparagano, Olivier; George, David; Giangaspero, Annunziata; Špitalská, Eva

    2015-09-30

    Geographic spread of parasites and pathogens poses a constant risk to animal health and welfare, particularly given that climate change is expected to potentially expand appropriate ranges for many key species. The spread of deleterious organisms via trade routes and human travelling is relatively closely controlled, though represents only one possible means of parasite/pathogen distribution. The transmission via natural parasite/pathogen movement between geographic locales, is far harder to manage. Though the extent of such movement may be limited by the relative inability of many parasites and pathogens to actively migrate, passive movement over long distances may still occur via migratory hosts. This paper reviews the potential role of migrating birds in the transfer of ectoparasites and pathogens between geographic locales, focusing primarily on ticks. Bird-tick-pathogen relationships are considered, and evidence provided of long-range parasite/pathogen transfer from one location to another during bird migration events. As shown in this paper not only many different arthropod species are carried by migrating birds but consequently these pests carry many different pathogens species which can be transmitted to the migrating birds or to other animal species when those arthropods are dropping during these migrations. Data available from the literature are provided highlighting the need to understand better dissemination paths and disease epidemiology. PMID:26343302

  2. New genome size estimates of 134 species of arthropods.

    PubMed

    Hanrahan, Shawn Jason; Johnston, J Spencer

    2011-08-01

    Insect genome size diversity remains poorly sampled, with sparse and sporadic sampling of a few select orders and with many orders unrepresented or underrepresented in the genome size database. Here, we present 134 genome size estimates for 18 orders, including the first ever genome size estimates for eight orders, 38 families, 102 genera, and 131 species. Also reported here are three insect species genome size estimates that are corrections for unpublished genome size values that made it into the literature, including the smallest arthropod genome of the two spot spider mite (1C = 91 Mb). These estimates range from 91 to 7,752 Mb and provide a broader picture of genome size variation within Insecta and among all Arthropods. Proposed developmental constraints for holometabolous insect genome sizes are supported, with the majority of the species examined falling well under the hypothesized 1,978 Mb (2 pg) limit. The only exceptions occur in the highly diverse beetles (Coleoptera) (154 < 1C < 2,578) and the Mecoptera (1,890 < 1C < 2,134). Hemimetabolous orders include species with larger genomes. Of these, the Orthopteran genomes remain the largest (675 < 1C < 7,752). Hemipteran genomes are smaller (407 < 1C < 1,230), but with a very notable exception, the Cicadidae family, with bloated genomes (5,238 < 1C < 7,000 Mb) of a size previously known to exist only within Orthoptera. The genome sizes in all other Hemimetabolous orders (521 Mb < 1C < 3,860 Mb) fall within the range exhibited by the Hemiptera. New preparations and procedures for insect genome estimates with frozen material are described and discussed. To further improve and extend the number and quality of arthropod genome size estimates, a new flow cytometry insect standard, Blattaria: Periplaneta americana♂ (1C = 3,338 Mb) is established for genome size determination of insect genomes in excess of 2,000 Mb. PMID:21877225

  3. Perspectives on the evolutionary ecology of arthropod antimicrobial peptides.

    PubMed

    Rolff, Jens; Schmid-Hempel, Paul

    2016-05-26

    Antimicrobial peptides (AMPs) are important elements of the innate immune defence in multicellular organisms that target and kill microbes. Here, we reflect on the various points that are raised by the authors of the 11 contributions to a special issue of Philosophical Transactions on the 'evolutionary ecology of arthropod antimicrobial peptides'. We see five interesting topics emerging. (i) AMP genes in insects, and perhaps in arthropods more generally, evolve much slower than most other immune genes. One explanation refers to the constraints set by AMPs being part of a finely tuned defence system. A new view argues that AMPs are under strong stabilizing selection. Regardless, this striking observation still invites many more questions than have been answered so far. (ii) AMPs almost always are expressed in combinations and sometimes show expression patterns that are dependent on the infectious agent. While it is often assumed that this can be explained by synergistic interactions, such interactions have rarely been demonstrated and need to be studied further. Moreover, how to define synergy in the first place remains difficult and needs to be addressed. (iii) AMPs play a very important role in mediating the interaction between a host and its mutualistic or commensal microbes. This has only been studied in a very small number of (insect) species. It has become clear that the very same AMPs play different roles in different situations and hence are under concurrent selection. (iv) Different environments shape the physiology of organisms; especially the host-associated microbial communities should impact on the evolution host AMPs. Studies in social insects and some organisms from extreme environments seem to support this notion, but, overall, the evidence for adaptation of AMPs to a given environment is scant. (v) AMPs are considered or already developed as new drugs in medicine. However, bacteria can evolve resistance to AMPs. Therefore, in the light of our

  4. Interaction between arthropod filiform hairs in a fluid environment.

    PubMed

    Cummins, Bree; Gedeon, Tomás; Klapper, Isaac; Cortez, Ricardo

    2007-07-21

    Many arthropods use filiform hairs as mechanoreceptors to detect air motion. In common house crickets (Acheta domestica) the hairs cover two antenna-like appendages called cerci at the rear of the abdomen. The biomechanical stimulus-response properties of individual filiform hairs have been investigated and modeled extensively in several earlier studies. However, only a few previous studies have considered viscosity-mediated coupling between pairs of hairs, and only in particular configurations. Here, we present a model capable of calculating hair-to-hair coupling in arbitrary configurations. We simulate the coupled motion of a small group of mechanosensory hairs on a cylindrical section of cercus. We have found that the coupling effects are non-negligible, and likely constrain the operational characteristics of the cercal sensory array. PMID:17434184

  5. Identification of a Flavivirus Sequence in a Marine Arthropod

    PubMed Central

    Conway, Michael J.

    2015-01-01

    Phylogenetic analysis has yet to uncover the early origins of flaviviruses. In this study, I mined a database of expressed sequence tags in order to discover novel flavivirus sequences. Flavivirus sequences were identified in a pool of mRNA extracted from the sea spider Endeis spinosa (Pycnogonida, Pantopoda). Reconstruction of the translated sequences and BLAST analysis matched the sequence to the flavivirus NS5 gene. Additional sequences corresponding to envelope and the NS5 MTase domain were also identified. Phylogenetic analysis of homologous NS5 sequences revealed that Endeis spinosa NS5 (ESNS5) is likely related to classical insect-specific flaviviruses. It is unclear if ESNS5 represents genetic material from an active viral infection or an integrated viral genome. These data raise the possibility that classical insect-specific flaviviruses and perhaps medically relevant flaviviruses, evolved from progenitors that infected marine arthropods. PMID:26717191

  6. Comparison of Arthropod Prey of Red-Cockaded Woodpeckers on the Boles of Longleaf and Loblolly Pines

    SciTech Connect

    Horn, S.; Hanula, J.

    2002-01-01

    Use of knockdown insecticides to sample arthropods on longleaf and loblolly pine to determine which harbored the greater abundance of potential prey. Alterations of longleaf pine bark surface to determine whether bark structure may affect arthropods residing on a tree's bole. Recovery revealed fewer arthropods from scraped trees. Results suggest the bark structure and not the chemical nature of the bark is responsible for differences in arthropod abundance and biomass. Retaining or restoring longleaf pine in red-cockaded woodpecker habitats should increase arthropod availability for this endangered bird and other back-foraging species.

  7. Acquisition of Cry1Ac Protein by Non-Target Arthropods in Bt Soybean Fields

    PubMed Central

    Yu, Huilin; Romeis, Jörg; Li, Yunhe; Li, Xiangju; Wu, Kongming

    2014-01-01

    Soybean tissue and arthropods were collected in Bt soybean fields in China at different times during the growing season to investigate the exposure of arthropods to the plant-produced Cry1Ac toxin and the transmission of the toxin within the food web. Samples from 52 arthropod species/taxa belonging to 42 families in 10 orders were analysed for their Cry1Ac content using enzyme-linked immunosorbent assay (ELISA). Among the 22 species/taxa for which three samples were analysed, toxin concentration was highest in the grasshopper Atractomorpha sinensis and represented about 50% of the concentration in soybean leaves. Other species/taxa did not contain detectable toxin or contained a concentration that was between 1 and 10% of that detected in leaves. These Cry1Ac-positive arthropods included a number of mesophyll-feeding Hemiptera, a cicadellid, a curculionid beetle and, among the predators, a thomisid spider and an unidentified predatory bug belonging to the Anthocoridae. Within an arthropod species/taxon, the Cry1Ac content sometimes varied between life stages (nymphs/larvae vs. adults) and sampling dates (before, during, and after flowering). Our study is the first to provide information on Cry1Ac-expression levels in soybean plants and Cry1Ac concentrations in non-target arthropods in Chinese soybean fields. The data will be useful for assessing the risk of non-target arthropod exposure to Cry1Ac in soybean. PMID:25110881

  8. Effects of persistent insecticides on beneficial soil arthropod in conventional fields compared to organic fields, puducherry.

    PubMed

    Anbarashan, Padmavathy; Gopalswamy, Poyyamoli

    2013-07-15

    The usage of synthetic fertilizers/insecticides in conventional farming has dramatically increased over the past decades. The aim of the study was to compare the effects of bio-pesticides and insecticides/pesticides on selected beneficial non targeted arthropods. Orders Collembola, Arachinida/Opiliones, Oribatida and Coleoptera were the main groups of arthropods found in the organic fields and Coleoptera, Oribatida, Gamasida and Collembola in conventional fields. Pesticides/insecticides had a significant effect on non-targeted arthropods order- Collembola, Arachinida/Opiliones, Hymenoptera and Thysonoptera were suppressed after pesticides/insecticides spraying. Bio-insecticides in organic fields had a non-significant effect on non targeted species and they started to increase in abundance after 7 days of spraying, whereas insecticide treatment in conventional fields had a significant long-term effect on non targeted arthropods and short term effect on pests/insects, it started to increase after 21 days of the spraying. These results indicate that insecticide treatment kept non targeted arthropods at low abundance. In conclusion, organic farming does not significantly affected the beneficial-non targeted arthropods biodiversity, whereas preventive insecticide application in conventional fields had significant negative effects on beneficial non targeted arthropods. Therefore, conventional farmers should restrict insecticide applications, unless pest densities reach the thresholds and more desirably can switch to organic farming practices. PMID:24505991

  9. Arthropod abundance and seasonal bird use of bottomland forest harvest gaps.

    SciTech Connect

    Moorman, Christopher, E.; Bowen, Liessa T.; Kilgo, John, C.; Hanula, James, L.; Horn, Scott; Ulyshen, Michael, D.

    2012-03-01

    We investigated the influence of arthropod abundance and vegetation structure on shifts in avian use of canopy gap, gap edge, and surrounding forest understory in a bottomland hardwood forest in the Upper Coastal Plain of South Carolina. We compared captures of foliage-gleaning birds among locations during four periods (spring migration, breeding, post-breeding, and fall migration). Foliage arthropod densities were greatest in the forest understory in all four seasons, but understory vegetation density was greatest in gaps. Foliage-gleaning bird abundance was positively associated with foliage-dwelling arthropods during the breeding (F = 18.5, P < 0.001) and post-breeding periods (F = 9.4, P = 0.004), and negatively associated with foliage-dwelling arthropods during fall migration (F = 5.4, P = 0.03). Relationships between birds and arthropods were inconsistent, but the arthropod prey base seemed to be least important during migratory periods. Conversely, bird captures were positively correlated with understory vegetation density during all four periods (P < 0.001). Our study suggests high bird abundance associated with canopy gaps during the non-breeding period resulted less from high arthropod food resource availability than from complex understory and midstory vegetation structure.

  10. Acquisition of Cry1Ac protein by non-target arthropods in Bt soybean fields.

    PubMed

    Yu, Huilin; Romeis, Jörg; Li, Yunhe; Li, Xiangju; Wu, Kongming

    2014-01-01

    Soybean tissue and arthropods were collected in Bt soybean fields in China at different times during the growing season to investigate the exposure of arthropods to the plant-produced Cry1Ac toxin and the transmission of the toxin within the food web. Samples from 52 arthropod species/taxa belonging to 42 families in 10 orders were analysed for their Cry1Ac content using enzyme-linked immunosorbent assay (ELISA). Among the 22 species/taxa for which three samples were analysed, toxin concentration was highest in the grasshopper Atractomorpha sinensis and represented about 50% of the concentration in soybean leaves. Other species/taxa did not contain detectable toxin or contained a concentration that was between 1 and 10% of that detected in leaves. These Cry1Ac-positive arthropods included a number of mesophyll-feeding Hemiptera, a cicadellid, a curculionid beetle and, among the predators, a thomisid spider and an unidentified predatory bug belonging to the Anthocoridae. Within an arthropod species/taxon, the Cry1Ac content sometimes varied between life stages (nymphs/larvae vs. adults) and sampling dates (before, during, and after flowering). Our study is the first to provide information on Cry1Ac-expression levels in soybean plants and Cry1Ac concentrations in non-target arthropods in Chinese soybean fields. The data will be useful for assessing the risk of non-target arthropod exposure to Cry1Ac in soybean. PMID:25110881

  11. New insights on arthropod toxins that potentiate erectile function.

    PubMed

    Nunes, Kenia P; Torres, Fernanda S; Borges, Marcia H; Matavel, Alessandra; Pimenta, Adriano M C; De Lima, Maria E

    2013-07-01

    The use of natural substances for the treatment of diseases or injuries is an ancient practice of many cultures. According to folklore, natural aphrodisiacs may help to raise libido and increase desire. The supposed aphrodisiacs mainly include a plethora of preparations of plants, among other substances. However, the real boundary between myth and reality has not been established yet in most cases and such boundaries must be drawn by scientific methods. A growing interest of the scientific community has been focused on animal venoms, especially those from arthropods, i.e. spiders and scorpions, which cause priapism, a prolonged and painful erection. This review highlights the studies that have been performed with venoms and toxins from arthropods known to cause priapism, among other toxic symptoms, pointing out some pharmacological approaches for better understanding this effect. To date, the venom of some spiders, mainly Phoneutria nigriventer, and scorpions, such as the yellow South American scorpion Tityus serrulatus, among others, have been known to cause priapism. Since erectile dysfunction (ED) is a growing health problem in the world, more common in patients with vascular diseases as diabetes and hypertension, the use of animal venoms and toxins as pharmacological tools could not only shed light to the mechanisms involved in erectile function, but also represent a possible model for new drugs to treat ED. Unfortunately, attempts to correlate the structure of those priapism-related toxins were unfruitful. Such difficulties lie firstly on the poor data concerning purified priapism-related toxins, instead of whole venoms and/or semi-purified fractions, and secondly, on the scarce available primary sequences and structural data, mainly from spider toxins. It has been shown that all these toxins modify the sodium (Na(+)) channel activity, mostly slowing down its inactivation current. Improving the knowledge on the tertiary structure of these toxins could provide

  12. Phenoptosis in arthropods and immortality of social insects.

    PubMed

    Kartsev, V M

    2014-10-01

    In general, there are no drastic differences in phenoptosis patterns in plant and animal organisms. However, there are some specific features characteristic for insects and other arthropods: 1) their development includes metamorphosis with different biochemical laws at consecutive developmental stages; 2) arthropods can reduce or stop development and aging when in a state of diapause or temporal cold immobility; 3) their life cycle often correlates with seasonal changes of surroundings; 4) polymorphism is widespread - conspecifics differ by their lifespans and phenoptosis features; 5) lifespan-related sexual dimorphism is common; 6) significant situational plasticity of life cycle organization is an important feature; for example, the German wasp (Paravespula germanica) is obligatorily univoltine in the temperate zone, while in tropical regions its lifespan increases and leads to repeated reproduction; 7) life cycles of closely related species may differ significantly, for example, in contrast to German wasp, some tropical hornets (Vespa) have only one reproduction period. Surprisingly, many insect species have been shown to be subjected to gradual aging and phenoptosis, like the highest mammals. However, queens of social insects and some long-lived arachnids can apparently be considered non-aging organisms. In some species, lifespan is limited to one season, while others live much longer or shorter. Cases of one-time reproduction are rather rare. Aphagia is common in insects (over 10,000 species). Cannibalism is an important mortality factor in insects as well as in spiders. In social insects, which exist only in colonies (families), the lifetime of a colony can be virtually unlimited. However, in case of some species the developmental cycle and death of a colony after its completion are predetermined. Most likely, natural selection in insects does not lengthen individual lifespan, but favors increase in reproduction efficiency based on fast succession of

  13. Decoding the ubiquitin-mediated pathway of arthropod disease vectors.

    PubMed

    Choy, Anthony; Severo, Maiara S; Sun, Ruobai; Girke, Thomas; Gillespie, Joseph J; Pedra, Joao H F

    2013-01-01

    Protein regulation by ubiquitin has been extensively described in model organisms. However, characterization of the ubiquitin machinery in disease vectors remains mostly unknown. This fundamental gap in knowledge presents a concern because new therapeutics are needed to control vector-borne diseases, and targeting the ubiquitin machinery as a means for disease intervention has been already adopted in the clinic. In this study, we employed a bioinformatics approach to uncover the ubiquitin-mediated pathway in the genomes of Anopheles gambiae, Aedes aegypti, Culex quinquefasciatus, Ixodes scapularis, Pediculus humanus and Rhodnius prolixus. We observed that (1) disease vectors encode a lower percentage of ubiquitin-related genes when compared to Drosophila melanogaster, Mus musculus and Homo sapiens but not Saccharomyces cerevisiae; (2) overall, there are more proteins categorized as E3 ubiquitin ligases when compared to E2-conjugating or E1-activating enzymes; (3) the ubiquitin machinery within the three mosquito genomes is highly similar; (4) ubiquitin genes are more than doubled in the Chagas disease vector (R. prolixus) when compared to other arthropod vectors; (5) the deer tick I. scapularis and the body louse (P. humanus) genomes carry low numbers of E1-activating enzymes and HECT-type E3 ubiquitin ligases; (6) R. prolixus have low numbers of RING-type E3 ubiquitin ligases; and (7) C. quinquefasciatus present elevated numbers of predicted F-box E3 ubiquitin ligases, JAB and UCH deubiquitinases. Taken together, these findings provide novel opportunities to study the interaction between a pathogen and an arthropod vector. PMID:24205097

  14. Future rainfall patterns will reduce arthropod abundance in model arable agroecosystems with different soil types

    NASA Astrophysics Data System (ADS)

    Zaller, Johann; Simmer, Laura; Tabi Tataw, James; Formayer, Herbert; Hösch, Johannes; Baumgarten, Andreas

    2013-04-01

    Climate change scenarios for eastern Austria predict a seasonal shift in precipitation patterns with fewer but heavier rainfall events and longer drought periods during the growing season and more precipitation during winter. This is expected to alter arthropods living in natural and agricultural ecosystems with consequences for several ecosystem functions and services. In order to better understand the effects of future rainfall patterns on aboveground arthropods inhabiting an agroecosystem, we conducted an experiment where we simulated rainfall patterns in model arable systems with three different soil types. Experiments were conducted in winter wheat cultivated in a lysimeter facility near Vienna, Austria, where three different soil types (calcaric phaeozem, calcic chernozem and gleyic phaeozem) were subjected to long-term current vs. predicted rainfall patterns according to regionalized climate change projections for 2071-2100. Aboveground arthropods were assessed by suction sampling in April, May and June 2012. We found significant differences in mean total arthropod abundances between the sampling dates with 20 ± 2 m-2, 90 ± 20 m-2 and 289 ± 54 m-2 in April, May and June, respectively. Across all three sampling dates, future rainfall patterns significantly reduced the abundance of Araneae (-43%), Auchenorrhyncha (-39%), Coleoptera (-48%), Carabidae (-41%), Chrysomelidae (-64%), Collembola (-58%), Diptera (-75%) and Neuroptera (-73%). Generally, different soil types had no effect on the abundance of arthropods. The diversity of arthropod communities was unaffected by rainfall patterns or soil types. Correlation analyses of arthropod abundances with crop biomass, weed density and abundance suggest that rainfall effects indirectly affected arthropods via changes on crops and weeds. In conclusion, these results show that future rainfall patterns will have detrimental effects on the abundance of a variety of aboveground arthropods in winter wheat with potential

  15. Sweeping beauty: is grassland arthropod community composition effectively estimated by sweep netting?

    PubMed Central

    Spafford, Ryan D; Lortie, Christopher J

    2013-01-01

    Arthropods are critical ecosystem components due to their high diversity and sensitivity to perturbation. Furthermore, due to their ease of capture they are often the focus of environmental health surveys. There is much debate regarding the best sampling method to use in these surveys. Sweep netting and pan trapping are two sampling methods commonly used in agricultural arthropod surveys, but have not been contrasted in natural grassland systems at the community level. The purpose of this study was to determine whether sweep netting was effective at estimating arthropod diversity at the community level in grasslands or if supplemental pan trapping was needed. Arthropods were collected from grassland sites in Montana, USA, in the summer of 2011. The following three standardized evaluation criteria (consistency, reliability, and precision) were developed to assess the efficacy of sweep netting and pan trapping, based on analyses of variations in arthropod abundances, species richness, evenness, capture frequency, and community composition. Neither sampling method was sufficient in any criteria to be used alone for community-level arthropod surveys. On a taxa-specific basis, however, sweep netting was consistent, reliable, and precise for Thysanoptera, infrequently collected (i.e., rare) insects, and Arachnida, whereas pan trapping was consistent, reliable, and precise for Collembola and bees, which is especially significant given current threats to the latter's populations worldwide. Species-level identifications increase the detected dissimilarity between sweep netting and pan trapping. We recommend that community-level arthropod surveys use both sampling methods concurrently, at least in grasslands, but likely in most nonagricultural systems. Target surveys, such as monitoring bee communities in fragmented grassland habitat or where detailed information on behavior of the target arthropod groups is available can in some instances employ singular methods. As a

  16. High-performance micromachined vibratory rate- and rate-integrating gyroscopes

    NASA Astrophysics Data System (ADS)

    Cho, Jae Yoong

    The performance of vibratory micromachined gyroscopes has been continuously improving for the past two decades. However, to further improve performance of the MEMS gyroscope in harsh environment, it is necessary for gyros to reduce the sensitivity to environmental parameters, including vibration and temperature change. In addition, conventional rate-mode MEMS gyroscopes have limitation in performance due to tradeoff between resolution, bandwidth, and full-scale range. In this research, we aim to reduce vibration sensitivity by developing gyros that operate in the balanced mode. The balanced mode creates zero net momentum and reduces energy loss through an anchor. The gyro can differentially cancel measurement errors from external vibration along both sensor axes. The vibration sensitivity of the balanced-mode gyroscope including structural imbalance from microfabrication reduces as the absolute difference between in-phase parasitic mode and operating mode frequencies increases. The parasitic sensing mode frequency is designed larger than the operating mode frequency to achieve both improved vibration insensitivity and shock resistivity. A single anchor is used in order to minimize thermoresidual stress change. We developed two gyroscope based on these design principles. The Balanced Oscillating Gyro (BOG) is a quad-mass tuning-fork rate gyroscope. The relationship between gyro design and modal characteristics is studied extensively using finite element method (FEM). The gyro is fabricated using the planar Si-on-glass (SOG) process with a device thickness of 100microm. The BOG is evaluated using the first-generation analog interface circuitry. Under a frequency mismatch of 5Hz between driving and sense modes, the angle random walk (ARW) is measured to be 0.44°/sec/✓Hz. The performance is limited by quadrature error and low-frequency noise in the circuit. The Cylindrical Rate-Integrating Gyroscope (CING) operates in whole-angle mode. The gyro is completely

  17. Grassland Arthropods Are Controlled by Direct and Indirect Interactions with Cattle but Are Largely Unaffected by Plant Provenance

    PubMed Central

    Farrell, Kelly Anne; Harpole, W. Stanley; Stein, Claudia; Suding, Katharine N.; Borer, Elizabeth T.

    2015-01-01

    Cattle grazing and invasion by non-native plant species are globally-ubiquitous changes occurring to plant communities that are likely to reverberate through whole food webs. We used a manipulative field experiment to quantify how arthropod community structure differed in native and non-native California grassland communities in the presence and absence of grazing. The arthropod community was strongly affected by cattle grazing: the biovolume of herbivorous arthropods was 79% higher in grazed than ungrazed plots, whereas the biovolume of predatory arthropods was 13% higher in ungrazed plots. In plots where non-native grasses were grazed, arthropod biovolume increased, possibly in response to increased plant productivity or increased nutritional quality of rapidly-growing annual plants. Grazing may thus affect plant biomass both through the direct removal of biomass, and through arthropod-mediated impacts. We also expected the arthropod community to differ between native and non-native plant communities; surprisingly, arthropod richness and diversity did not vary consistently between these grass community types, although arthropod abundance was slightly higher in plots with native and ungrazed grasses. These results suggest that whereas cattle grazing affects the arthropod community via direct and indirect pathways, arthropod community changes commonly associated with non-native plant invasions may not be due to the identity or dominance of the invasive species in those systems, but to accompanying changes in plant traits or functional group composition, not seen in this experiment because of the similarity of the plant communities. PMID:26158494

  18. Unprecedented genomic diversity of RNA viruses in arthropods reveals the ancestry of negative-sense RNA viruses

    PubMed Central

    Li, Ci-Xiu; Shi, Mang; Tian, Jun-Hua; Lin, Xian-Dan; Kang, Yan-Jun; Chen, Liang-Jun; Qin, Xin-Cheng; Xu, Jianguo; Holmes, Edward C; Zhang, Yong-Zhen

    2015-01-01

    Although arthropods are important viral vectors, the biodiversity of arthropod viruses, as well as the role that arthropods have played in viral origins and evolution, is unclear. Through RNA sequencing of 70 arthropod species we discovered 112 novel viruses that appear to be ancestral to much of the documented genetic diversity of negative-sense RNA viruses, a number of which are also present as endogenous genomic copies. With this greatly enriched diversity we revealed that arthropods contain viruses that fall basal to major virus groups, including the vertebrate-specific arenaviruses, filoviruses, hantaviruses, influenza viruses, lyssaviruses, and paramyxoviruses. We similarly documented a remarkable diversity of genome structures in arthropod viruses, including a putative circular form, that sheds new light on the evolution of genome organization. Hence, arthropods are a major reservoir of viral genetic diversity and have likely been central to viral evolution. DOI: http://dx.doi.org/10.7554/eLife.05378.001 PMID:25633976

  19. Mid-Cretaceous charred fossil flowers reveal direct observation of arthropod feeding strategies.

    PubMed

    Hartkopf-Fröder, Christoph; Rust, Jes; Wappler, Torsten; Friis, Else Marie; Viehofen, Agnes

    2012-04-23

    Although plant-arthropod relationships underpin the dramatic rise in diversity and ecological dominance of flowering plants and their associated arthropods, direct observations of such interactions in the fossil record are rare, as these ephemeral moments are difficult to preserve. Three-dimensionally preserved charred remains of Chloranthistemon flowers from the Late Albian to Early Cenomanian of Germany preserve scales of mosquitoes and an oribatid mite with mouthparts inserted into the pollen sac. Mosquitoes, which today are frequent nectar feeders, and the mite were feeding on pollen at the time wildfire consumed the flowers. These findings document directly arthropod feeding strategies and their role in decomposition. PMID:21900310

  20. Mid-Cretaceous charred fossil flowers reveal direct observation of arthropod feeding strategies

    PubMed Central

    Hartkopf-Fröder, Christoph; Rust, Jes; Wappler, Torsten; Friis, Else Marie; Viehofen, Agnes

    2012-01-01

    Although plant–arthropod relationships underpin the dramatic rise in diversity and ecological dominance of flowering plants and their associated arthropods, direct observations of such interactions in the fossil record are rare, as these ephemeral moments are difficult to preserve. Three-dimensionally preserved charred remains of Chloranthistemon flowers from the Late Albian to Early Cenomanian of Germany preserve scales of mosquitoes and an oribatid mite with mouthparts inserted into the pollen sac. Mosquitoes, which today are frequent nectar feeders, and the mite were feeding on pollen at the time wildfire consumed the flowers. These findings document directly arthropod feeding strategies and their role in decomposition. PMID:21900310

  1. Changes in soil temperature during prescribed burns impact local arthropod communities

    NASA Astrophysics Data System (ADS)

    Verble-Pearson, Robin; Perry, Gad

    2016-04-01

    As wildfires increase in severity and intensity globally, the development of methods to assess their effects on soils is of increasing importance. We examined soil arthropod communities in the southern United States and estimated their abundance, species richness, and composition in areas recently impacted by prescribed burns. In addition, we placed thermal probes in soils and correlated soil temperatures to arthropod responses. Longer fire residence times resulted in greater soil heating which resulted in decreases in arthropod abundance and species richness and shifts in species composition. We believe that these results may be useful in developing tools to assess fire effects on soil systems.

  2. Longleaf Pine Characterists Associated with Arthropods Available for Red-Cockaded Woodpeckers

    SciTech Connect

    Hanula, J.L.; Franzreb, K.E.; Pepper, W.D.

    1999-01-25

    The authors sampled arthropods on 300 longleaf pine under varying stand conditions and ranging in age from 20 to 100 years. The most diverse orders were beetles, spiders, ants, wasps and bees. The most abundant were aphids and Hymenoptera with a large number of ants. Arthropod biomass per tree increased in age up to 65-70 years, but biomass was highest in the youngest stands. Arthropods were positively correlated to bark thickness and tree diameter, but negatively related to the stand basal area. No relationships were found between abundance and ground vegetation conditions.

  3. Dual-mass vibratory rate gyroscope with suppressed translational acceleration response and quadrature-error correction capability

    NASA Technical Reports Server (NTRS)

    Clark, William A. (Inventor); Juneau, Thor N. (Inventor); Lemkin, Mark A. (Inventor); Roessig, Allen W. (Inventor)

    2001-01-01

    A microfabricated vibratory rate gyroscope to measure rotation includes two proof-masses mounted in a suspension system anchored to a substrate. The suspension has two principal modes of compliance, one of which is driven into oscillation. The driven oscillation combined with rotation of the substrate about an axis perpendicular to the substrate results in Coriolis acceleration along the other mode of compliance, the sense-mode. The sense-mode is designed to respond to Coriolis accelerationwhile suppressing the response to translational acceleration. This is accomplished using one or more rigid levers connecting the two proof-masses. The lever allows the proof-masses to move in opposite directions in response to Coriolis acceleration. The invention includes a means for canceling errors, termed quadrature error, due to imperfections in implementation of the sensor. Quadrature-error cancellation utilizes electrostatic forces to cancel out undesired sense-axis motion in phase with drive-mode position.

  4. The transducer vibratory profile effects on the detection of the transient ultrasonic field scattered by a rigid point reflector.

    PubMed

    Khelladi, Hassina; Djelouah, Hakim

    2010-04-01

    In this study a generalized approach, based on the impulse response technique, is developed to evaluate the transient ultrasonic field scattered by a rigid point reflector and detected by a planar circular transducer characterized by a non-uniform vibratory profile. For this purpose, several analytical functions are used to represent the non-uniform vibration amplitude of the transducer. All these functions have maximum amplitude at the transducer's center and decrease monotonically away from axis. The amplitude variation of these functions has a direct effect on the shape of the average pressure detected by the transducer. Some numerical results are presented to illustrate the effects of a non-uniformly vibrating source on the detected transient pressure. The results show the relative importance of the edge wave modifications in the case of source having non-uniform vibration amplitude distribution. PMID:19906391

  5. Modulating the Behaviors of Mesenchymal Stem Cells Via the Combination of High-Frequency Vibratory Stimulations and Fibrous Scaffolds

    PubMed Central

    Tong, Zhixiang; Duncan, Randall L.

    2013-01-01

    We are interested in the in vitro engineering of artificial vocal fold tissues via the strategic combination of multipotent mesenchymal stem cells (MSCs), physiologically relevant mechanical stimulations, and biomimetic artificial matrices. We have constructed a vocal fold bioreactor that is capable of imposing vibratory stimulations on the cultured cells at human phonation frequencies. Separately, fibrous poly (ɛ-caprolactone) (PCL) scaffolds emulating the ligamentous structure of the vocal fold were prepared by electrospinning, were incorporated in the vocal fold bioreactor, and were driven into a wave-like motion in an axisymmetrical fashion by the oscillating air. MSC-laden PCL scaffolds were subjected to vibrations at 200 Hz with a normal center displacement of ∼40 μm for a total of 7 days. A continuous (CT) or a 1 h-on-1 h-off (OF) regime with a total dynamic culture time of 12 h per day was applied. The dynamic loading did not cause any physiological trauma to the cells. Immunohistotochemical staining revealed the reinforcement of the actin filament and the enhancement of α5β1 integrin expression under selected dynamic culture conditions. Cellular expression of essential vocal fold extracellular matrix components, such as elastin, hyaluronic acid, and matrix metalloproteinase-1, was significantly elevated as compared with the static controls, and the OF regime is more conducive to matrix production than the CT vibration mode. Analyses of genes of typical fibroblast hallmarks (tenascin-C, collagen III, and procollagen I) as well as markers for MSC differentiation into nonfibroblastic lineages confirmed MSCs' adaptation of fibroblastic behaviors. Overall, the high-frequency vibratory stimulation, when combined with a synthetic fibrous scaffold, serves as a potent modulator of MSC functions. The novel bioreactor system presented here, as a versatile, yet well-controlled model, offers an in vitro platform for understanding vibration

  6. Introduction to symposium: Arthropods and wildlife conservation: synergy in complex biological systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The symposium will discuss the effects of arthropods and other stressors on wildlife conservation programs. Speakers with affiliations in wildlife biology, parasitology and entomology will be included in the program. Research of national and international interest will be presented....

  7. Tiny individuals attached to a new Silurian arthropod suggest a unique mode of brood care.

    PubMed

    Briggs, Derek E G; Siveter, Derek J; Siveter, David J; Sutton, Mark D; Legg, David

    2016-04-19

    The ∼430-My-old Herefordshire, United Kingdom, Lagerstätte has yielded a diversity of remarkably preserved invertebrates, many of which provide fundamental insights into the evolutionary history and ecology of particular taxa. Here we report a new arthropod with 10 tiny arthropods tethered to its tergites by long individual threads. The head of the host, which is covered by a shield that projects anteriorly, bears a long stout uniramous antenna and a chelate limb followed by two biramous appendages. The trunk comprises 11 segments, all bearing limbs and covered by tergites with long slender lateral spines. A short telson bears long parallel cerci. Our phylogenetic analysis resolves the new arthropod as a stem-group mandibulate. The evidence suggests that the tethered individuals are juveniles and the association represents a complex brooding behavior. Alternative possibilities-that the tethered individuals represent a different epizoic or parasitic arthropod-appear less likely. PMID:27044103

  8. Implication of haematophagous arthropod salivary proteins in host-vector interactions

    PubMed Central

    2011-01-01

    The saliva of haematophagous arthropods contains an array of anti-haemostatic, anti-inflammatory and immunomodulatory molecules that contribute to the success of the blood meal. The saliva of haematophagous arthropods is also involved in the transmission and the establishment of pathogens in the host and in allergic responses. This survey provides a comprehensive overview of the pharmacological activity and immunogenic properties of the main salivary proteins characterised in various haematophagous arthropod species. The potential biological and epidemiological applications of these immunogenic salivary molecules will be discussed with an emphasis on their use as biomarkers of exposure to haematophagous arthropod bites or vaccine candidates that are liable to improve host protection against vector-borne diseases. PMID:21951834

  9. Exceptional preservation of eye structure in arthropod visual predators from the Middle Jurassic

    PubMed Central

    Vannier, Jean; Schoenemann, Brigitte; Gillot, Thomas; Charbonnier, Sylvain; Clarkson, Euan

    2016-01-01

    Vision has revolutionized the way animals explore their environment and interact with each other and rapidly became a major driving force in animal evolution. However, direct evidence of how ancient animals could perceive their environment is extremely difficult to obtain because internal eye structures are almost never fossilized. Here, we reconstruct with unprecedented resolution the three-dimensional structure of the huge compound eye of a 160-million-year-old thylacocephalan arthropod from the La Voulte exceptional fossil biota in SE France. This arthropod had about 18,000 lenses on each eye, which is a record among extinct and extant arthropods and is surpassed only by modern dragonflies. Combined information about its eyes, internal organs and gut contents obtained by X-ray microtomography lead to the conclusion that this thylacocephalan arthropod was a visual hunter probably adapted to illuminated environments, thus contradicting the hypothesis that La Voulte was a deep-water environment. PMID:26785293

  10. Exceptional preservation of eye structure in arthropod visual predators from the Middle Jurassic.

    PubMed

    Vannier, Jean; Schoenemann, Brigitte; Gillot, Thomas; Charbonnier, Sylvain; Clarkson, Euan

    2016-01-01

    Vision has revolutionized the way animals explore their environment and interact with each other and rapidly became a major driving force in animal evolution. However, direct evidence of how ancient animals could perceive their environment is extremely difficult to obtain because internal eye structures are almost never fossilized. Here, we reconstruct with unprecedented resolution the three-dimensional structure of the huge compound eye of a 160-million-year-old thylacocephalan arthropod from the La Voulte exceptional fossil biota in SE France. This arthropod had about 18,000 lenses on each eye, which is a record among extinct and extant arthropods and is surpassed only by modern dragonflies. Combined information about its eyes, internal organs and gut contents obtained by X-ray microtomography lead to the conclusion that this thylacocephalan arthropod was a visual hunter probably adapted to illuminated environments, thus contradicting the hypothesis that La Voulte was a deep-water environment. PMID:26785293

  11. Dynamics of the Leaf-Litter Arthropod Fauna Following Fire in a Neotropical Woodland Savanna

    PubMed Central

    Vasconcelos, Heraldo L.; Pacheco, Renata; Silva, Raphael C.; Vasconcelos, Pedro B.; Lopes, Cauê T.; Costa, Alan N.; Bruna, Emilio M.

    2009-01-01

    Fire is an important agent of disturbance in tropical savannas, but relatively few studies have analyzed how soil-and-litter dwelling arthropods respond to fire disturbance despite the critical role these organisms play in nutrient cycling and other biogeochemical processes. Following the incursion of a fire into a woodland savanna ecological reserve in Central Brazil, we monitored the dynamics of litter-arthropod populations for nearly two years in one burned and one unburned area of the reserve. We also performed a reciprocal transplant experiment to determine the effects of fire and litter type on the dynamics of litter colonization by arthropods. Overall arthropod abundance, the abundance of individual taxa, the richness of taxonomic groups, and the species richness of individual taxa (Formiciade) were lower in the burned site. However, both the ordinal-level composition of the litter arthropod fauna and the species-level composition of the litter ant fauna were not dramatically different in the burned and unburned sites. There is evidence that seasonality of rainfall interacts with fire, as differences in arthropod abundance and diversity were more pronounced in the dry than in the wet season. For many taxa the differences in abundance between burned and unburned sites were maintained even when controlling for litter availability and quality. In contrast, differences in abundance for Collembola, Formicidae, and Thysanoptera were only detected in the unmanipulated samples, which had a lower amount of litter in the burned than in the unburned site throughout most of our study period. Together these results suggest that arthropod density declines in fire-disturbed areas as a result of direct mortality, diminished resources (i.e., reduced litter cover) and less favorable microclimate (i.e., increased litter desiccation due to reduction in tree cover). Although these effects were transitory, there is evidence that the increasingly prevalent fire return interval of

  12. Dynamics of the leaf-litter arthropod fauna following fire in a neotropical woodland savanna.

    PubMed

    Vasconcelos, Heraldo L; Pacheco, Renata; Silva, Raphael C; Vasconcelos, Pedro B; Lopes, Cauê T; Costa, Alan N; Bruna, Emilio M

    2009-01-01

    Fire is an important agent of disturbance in tropical savannas, but relatively few studies have analyzed how soil-and-litter dwelling arthropods respond to fire disturbance despite the critical role these organisms play in nutrient cycling and other biogeochemical processes. Following the incursion of a fire into a woodland savanna ecological reserve in Central Brazil, we monitored the dynamics of litter-arthropod populations for nearly two years in one burned and one unburned area of the reserve. We also performed a reciprocal transplant experiment to determine the effects of fire and litter type on the dynamics of litter colonization by arthropods. Overall arthropod abundance, the abundance of individual taxa, the richness of taxonomic groups, and the species richness of individual taxa (Formiciade) were lower in the burned site. However, both the ordinal-level composition of the litter arthropod fauna and the species-level composition of the litter ant fauna were not dramatically different in the burned and unburned sites. There is evidence that seasonality of rainfall interacts with fire, as differences in arthropod abundance and diversity were more pronounced in the dry than in the wet season. For many taxa the differences in abundance between burned and unburned sites were maintained even when controlling for litter availability and quality. In contrast, differences in abundance for Collembola, Formicidae, and Thysanoptera were only detected in the unmanipulated samples, which had a lower amount of litter in the burned than in the unburned site throughout most of our study period. Together these results suggest that arthropod density declines in fire-disturbed areas as a result of direct mortality, diminished resources (i.e., reduced litter cover) and less favorable microclimate (i.e., increased litter desiccation due to reduction in tree cover). Although these effects were transitory, there is evidence that the increasingly prevalent fire return interval of

  13. Bison grazing increases arthropod abundance and diversity in a tallgrass prairie.

    PubMed

    Moran, Matthew D

    2014-10-01

    How grazing-induced ecosystem changes by ungulates indirectly affect other consumers is a question of great interest. I investigated the effect of grazing by American Bison (Bos bison L.) on an arthropod community in tallgrass prairie. Grazing increased the abundance of arthropods, an increase that was present in both herbivorous and carnivorous assemblages, but not in detritivores. The increase in herbivores and reduction in plant biomass from grazing resulted in an arthropod herbivore load almost three times higher in grazed plots compared with controls. Among herbivores, the sap-feeding insect guild was dramatically more abundant, while chewing herbivores were not affected. Herbivorous and carnivorous arthropod richness was higher in grazed plots, although the response was strongest among herbivores. Arthropod abundance on individual grasses and forbs was significantly higher in grazed areas, while plant type had no effect on abundance, indicating that the change was ecosystem-wide and not simply in response to a reduction in grass biomass from grazing. The response of arthropods to grazing was strongest in the early part of the growing season. Published research shows that ungulate grazing, although decreasing available biomass to other consumers, enhances plant quality by increasing nitrogen level in plants. The arthropod results of this study suggest higher plant quality outweighs the potential negative competitive effects of plant biomass removal, although other activities of bison could not be ruled out as the causative mechanism. Because arthropods are extremely abundant organisms in grasslands and a food source for other consumers, bison may represent valuable management tools for maintaining biodiversity. PMID:25198902

  14. Nematode and Arthropod Genomes Provide New Insights into the Evolution of Class 2 B1 GPCRs

    PubMed Central

    Cardoso, João C. R.; Félix, Rute C.; Power, Deborah M.

    2014-01-01

    Nematodes and arthropods are the most speciose animal groups and possess Class 2 B1 G-protein coupled receptors (GPCRs). Existing models of invertebrate Class 2 B1 GPCR evolution are mainly centered on Caenorhabditis elegans and Drosophila melanogaster and a few other nematode and arthropod representatives. The present study reevaluates the evolution of metazoan Class 2 B1 GPCRs and orthologues by exploring the receptors in several nematode and arthropod genomes and comparing them to the human receptors. Three novel receptor phylogenetic clusters were identified and designated cluster A, cluster B and PDF-R-related cluster. Clusters A and B were identified in several nematode and arthropod genomes but were absent from D. melanogaster and Culicidae genomes, whereas the majority of the members of the PDF-R-related cluster were from nematodes. Cluster A receptors were nematode and arthropod-specific but shared a conserved gene environment with human receptor loci. Cluster B members were orthologous to human GCGR, PTHR and Secretin members with which they probably shared a common origin. PDF-R and PDF-R related clusters were present in representatives of both nematodes and arthropods. The results of comparative analysis of GPCR evolution and diversity in protostomes confirm previous notions that C. elegans and D. melanogaster genomes are not good representatives of nematode and arthropod phyla. We hypothesize that at least four ancestral Class 2 B1 genes emerged early in the metazoan radiation, which after the protostome-deuterostome split underwent distinct selective pressures that resulted in duplication and deletion events that originated the current Class 2 B1 GPCRs in nematode and arthropod genomes. PMID:24651821

  15. Abundance and Diversity of Soil Arthropods in the Olive Grove Ecosystem

    PubMed Central

    Gonçalves, Maria Fátima; Pereira, José Alberto

    2012-01-01

    Arthropods are part of important functional groups in soil food webs. Recognizing these arthropods and understanding their function in the ecosystem as well as when they are active is essential to understanding their roles. In the present work, the abundance and diversity of soil arthropods is examined in olive groves in the northeast region of Portugal during the spring. Five classes of arthropods were found: Chilopoda, Malacostraca, Entognatha, Insecta, and Arachnida. Captures were numerically dominated by Collembola within Entognatha, representing 70.9% of total captures. Arachnida and Insecta classes represented about 20.4 and 9.0%, respectively. Among the predatory arthropods, the most representative groups were Araneae and Opiliones from Arachnida, and Formicidae, Carabidae, and Staphylinidae from Insecta. From the Formicidae family, Tetramorium semilaeve (Andre 1883), Tapinoma nigerrimum (Nylander 1856), and Crematogaster scutellaris (Olivier 1792) were the most representative ant species. Arthropods demonstrated preference during the day, with 74% of the total individuals recovered in this period, although richness and similarity were analogous during the day and night. PMID:22943295

  16. Community structure and nutrient content of canopy arthropods in clearcut and uncut forest ecosystems

    SciTech Connect

    Schowalter, T.D.; Webb, J.W.; Crossley, D.A. Jr.

    1981-08-01

    This paper describes differences in canopy arthropod community structure, major cation content, and calculated nutrient consumption between clearcut and undisturbed hardwood forest watersheds at Coweeta Hydrologic Laboratory, North Carolina, USA, during the first two growing seasons following cutting. Although canopy arthropod biomass was about 0.08% of foliage biomass on both watersheds, aphid mass increased 23-fold and ant mass increased 6-fold per unit foliage mass following cutting. These groups in general had lower nutrient concentrations than did chewing herbivores and predators. Arthropod K concentrations were 33% lower on the clearcut; Na, K, and Mg concentrations were 20 to 50% higher in 1978 than in 1977. Arthropod Mg and Ca concentrations, but not Na and K, were reduced significantly more by the greater effect of drought on the clearcut watershed. Consumption estimates based in part on consumption rates reported by others indicated increased nutrient translocation from foilage via arthropods following cutting. These data indicated that canopy arthropod responses to changes in nutrient availability following disturbance could have increased nutrient cycling rates and contributed to nutrient retention by the recovering ecosystem.

  17. Abundance and diversity of soil arthropods in the olive grove ecosystem.

    PubMed

    Gonçalves, Maria Fátima; Pereira, José Alberto

    2012-01-01

    Arthropods are part of important functional groups in soil food webs. Recognizing these arthropods and understanding their function in the ecosystem as well as when they are active is essential to understanding their roles. In the present work, the abundance and diversity of soil arthropods is examined in olive groves in the northeast region of Portugal during the spring. Five classes of arthropods were found: Chilopoda, Malacostraca, Entognatha, Insecta, and Arachnida. Captures were numerically dominated by Collembola within Entognatha, representing 70.9% of total captures. Arachnida and Insecta classes represented about 20.4 and 9.0%, respectively. Among the predatory arthropods, the most representative groups were Araneae and Opiliones from Arachnida, and Formicidae, Carabidae, and Staphylinidae from Insecta. From the Formicidae family, Tetramorium semilaeve (Andre 1883), Tapinoma nigerrimum (Nylander 1856), and Crematogaster scutellaris (Olivier 1792) were the most representative ant species. Arthropods demonstrated preference during the day, with 74% of the total individuals recovered in this period, although richness and similarity were analogous during the day and night. PMID:22943295

  18. Silurian horseshoe crab illuminates the evolution of arthropod limbs.

    PubMed

    Briggs, Derek E G; Siveter, Derek J; Siveter, David J; Sutton, Mark D; Garwood, Russell J; Legg, David

    2012-09-25

    The basic arrangement of limbs in euarthropods consists of a uniramous head appendage followed by a series of biramous appendages. The body is divided into functional units or tagmata which are usually distinguished by further differentiation of the limbs. The living horseshoe crabs are remnants of a much larger diversity of aquatic chelicerates. The limbs of the anterior and posterior divisions of the body of living horseshoe crabs differ in the loss of the outer and inner ramus, respectively, of an ancestral biramous limb. Here we report a new fossil horseshoe crab from the mid-Silurian Lagerstätte in Herefordshire, United Kingdom (approximately 425 Myr B.P.), a site that has yielded a remarkably preserved assemblage of soft-bodied fossils. The limbs of the new form can be homologized with those of living Limulus, but retain an ancestral biramous morphology. Remarkably, however, the two limb branches originate separately, providing fossil evidence to suggest that repression or loss of gene expression might have given rise to the appendage morphology of Limulus. Both branches of the prosomal limbs of this new fossil are robust and segmented in contrast to their morphology in Cambrian arthropods, revealing that a true biramous limb was once present in chelicerates as well as in the mandibulates. PMID:22967511

  19. Silurian horseshoe crab illuminates the evolution of arthropod limbs

    NASA Astrophysics Data System (ADS)

    Briggs, Derek E. G.; Siveter, Derek J.; Siveter, David J.; Sutton, Mark D.; Garwood, Russell J.; Legg, David

    2012-09-01

    The basic arrangement of limbs in euarthropods consists of a uniramous head appendage followed by a series of biramous appendages. The body is divided into functional units or tagmata which are usually distinguished by further differentiation of the limbs. The living horseshoe crabs are remnants of a much larger diversity of aquatic chelicerates. The limbs of the anterior and posterior divisions of the body of living horseshoe crabs differ in the loss of the outer and inner ramus, respectively, of an ancestral biramous limb. Here we report a new fossil horseshoe crab from the mid-Silurian Lagerstätte in Herefordshire, United Kingdom (approximately 425 Myr B.P.), a site that has yielded a remarkably preserved assemblage of soft-bodied fossils. The limbs of the new form can be homologized with those of living Limulus, but retain an ancestral biramous morphology. Remarkably, however, the two limb branches originate separately, providing fossil evidence to suggest that repression or loss of gene expression might have given rise to the appendage morphology of Limulus. Both branches of the prosomal limbs of this new fossil are robust and segmented in contrast to their morphology in Cambrian arthropods, revealing that a true biramous limb was once present in chelicerates as well as in the mandibulates.

  20. No Accumulation of Transposable Elements in Asexual Arthropods.

    PubMed

    Bast, Jens; Schaefer, Ina; Schwander, Tanja; Maraun, Mark; Scheu, Stefan; Kraaijeveld, Ken

    2016-03-01

    Transposable elements (TEs) and other repetitive DNA can accumulate in the absence of recombination, a process contributing to the degeneration of Y-chromosomes and other nonrecombining genome portions. A similar accumulation of repetitive DNA is expected for asexually reproducing species, given their entire genome is effectively nonrecombining. We tested this expectation by comparing the whole-genome TE loads of five asexual arthropod lineages and their sexual relatives, including asexual and sexual lineages of crustaceans (Daphnia water fleas), insects (Leptopilina wasps), and mites (Oribatida). Surprisingly, there was no evidence for increased TE load in genomes of asexual as compared to sexual lineages, neither for all classes of repetitive elements combined nor for specific TE families. Our study therefore suggests that nonrecombining genomes do not accumulate TEs like nonrecombining genomic regions of sexual lineages. Even if a slight but undetected increase of TEs were caused by asexual reproduction, it appears to be negligible compared to variance between species caused by processes unrelated to reproductive mode. It remains to be determined if molecular mechanisms underlying genome regulation in asexuals hamper TE activity. Alternatively, the differences in TE dynamics between nonrecombining genomes in asexual lineages versus nonrecombining genome portions in sexual species might stem from selection for benign TEs in asexual lineages because of the lack of genetic conflict between TEs and their hosts and/or because asexual lineages may only arise from sexual ancestors with particularly low TE loads. PMID:26560353

  1. Inference on arthropod demographic parameters: computational advances using R.

    PubMed

    Maia, Aline De Holanda Nunes; Pazianotto, Ricardo Antonio De Almeida; Luiz, Alfredo José Barreto; Marinho-Prado, Jeanne Scardini; Pervez, Ahmad

    2014-02-01

    We developed a computer program for life table analysis using the open source, free software programming environment R. It is useful to quantify chronic nonlethal effects of treatments on arthropod populations by summarizing information on their survival and fertility in key population parameters referred to as fertility life table parameters. Statistical inference on fertility life table parameters is not trivial because it requires the use of computationally intensive methods for variance estimation. Our codes present some advantages with respect to a previous program developed in Statistical Analysis System. Additional multiple comparison tests were incorporated for the analysis of qualitative factors; a module for regression analysis was implemented, thus, allowing analysis of quantitative factors such as temperature or agrochemical doses; availability is granted for users, once it was developed using an open source, free software programming environment. To illustrate the descriptive and inferential analysis implemented in lifetable.R, we present and discuss two examples: 1) a study quantifying the influence of the proteinase inhibitor berenil on the eucalyptus defoliator Thyrinteina arnobia (Stoll) and 2) a study investigating the influence of temperature on demographic parameters of a predaceous ladybird, Hippodamia variegata (Goeze). PMID:24665730

  2. No Accumulation of Transposable Elements in Asexual Arthropods

    PubMed Central

    Bast, Jens; Schaefer, Ina; Schwander, Tanja; Maraun, Mark; Scheu, Stefan; Kraaijeveld, Ken

    2016-01-01

    Transposable elements (TEs) and other repetitive DNA can accumulate in the absence of recombination, a process contributing to the degeneration of Y-chromosomes and other nonrecombining genome portions. A similar accumulation of repetitive DNA is expected for asexually reproducing species, given their entire genome is effectively nonrecombining. We tested this expectation by comparing the whole-genome TE loads of five asexual arthropod lineages and their sexual relatives, including asexual and sexual lineages of crustaceans (Daphnia water fleas), insects (Leptopilina wasps), and mites (Oribatida). Surprisingly, there was no evidence for increased TE load in genomes of asexual as compared to sexual lineages, neither for all classes of repetitive elements combined nor for specific TE families. Our study therefore suggests that nonrecombining genomes do not accumulate TEs like nonrecombining genomic regions of sexual lineages. Even if a slight but undetected increase of TEs were caused by asexual reproduction, it appears to be negligible compared to variance between species caused by processes unrelated to reproductive mode. It remains to be determined if molecular mechanisms underlying genome regulation in asexuals hamper TE activity. Alternatively, the differences in TE dynamics between nonrecombining genomes in asexual lineages versus nonrecombining genome portions in sexual species might stem from selection for benign TEs in asexual lineages because of the lack of genetic conflict between TEs and their hosts and/or because asexual lineages may only arise from sexual ancestors with particularly low TE loads. PMID:26560353

  3. Arthropod eye-inspired digital camera with unique imaging characteristics

    NASA Astrophysics Data System (ADS)

    Xiao, Jianliang; Song, Young Min; Xie, Yizhu; Malyarchuk, Viktor; Jung, Inhwa; Choi, Ki-Joong; Liu, Zhuangjian; Park, Hyunsung; Lu, Chaofeng; Kim, Rak-Hwan; Li, Rui; Crozier, Kenneth B.; Huang, Yonggang; Rogers, John A.

    2014-06-01

    In nature, arthropods have a remarkably sophisticated class of imaging systems, with a hemispherical geometry, a wideangle field of view, low aberrations, high acuity to motion and an infinite depth of field. There are great interests in building systems with similar geometries and properties due to numerous potential applications. However, the established semiconductor sensor technologies and optics are essentially planar, which experience great challenges in building such systems with hemispherical, compound apposition layouts. With the recent advancement of stretchable optoelectronics, we have successfully developed strategies to build a fully functional artificial apposition compound eye camera by combining optics, materials and mechanics principles. The strategies start with fabricating stretchable arrays of thin silicon photodetectors and elastomeric optical elements in planar geometries, which are then precisely aligned and integrated, and elastically transformed to hemispherical shapes. This imaging device demonstrates nearly full hemispherical shape (about 160 degrees), with densely packed artificial ommatidia. The number of ommatidia (180) is comparable to those of the eyes of fire ants and bark beetles. We have illustrated key features of operation of compound eyes through experimental imaging results and quantitative ray-tracing-based simulations. The general strategies shown in this development could be applicable to other compound eye devices, such as those inspired by moths and lacewings (refracting superposition eyes), lobster and shrimp (reflecting superposition eyes), and houseflies (neural superposition eyes).

  4. Systemic immediate allergic reactions to arthropod stings and bites.

    PubMed

    Bircher, Andreas J

    2005-01-01

    Most of the encounters with biting and stinging insects result in more or less pronounced localized reactions. Typically, urticarial wheals and papular reactions are observed. Less often local bullous or hemorrhagic or disseminated papular reactions, particularly in children and immunologically naive adults, may be seen. With the exception of bee and wasp venom allergies, immediate-type allergic reactions to arthropod stings and bites are rare. Systemic IgE-mediated hypersensitivity has also been reported from additional hymenoptera species, e.g. hornets, bumble bees and ants. Rare are systemic reactions to mosquitoes, flies or kissing bugs and exceptional from ticks, bed bugs, moths, caterpillars and spiders. A major problem is the often lacking standardization of extracts for skin testing and for the determination of specific IgE. Some of the allergens have been characterized and few of them synthesized using recombinant techniques. Most investigations have been made with whole-body extracts or extracts from salivary glands, while desensitization has rarely been attempted. Currently, primary prevention by avoidance of stings and bites, and adequate instruction of sensitized individuals in the use of emergency drugs are mandatory. PMID:15724094

  5. Death rates reflect accumulating brain damage in arthropods.

    PubMed

    Fonseca, Duane B; Brancato, Carolina L; Prior, Andrew E; Shelton, Peter M J; Sheehy, Matt R J

    2005-09-22

    We present the results of the first quantitative, whole-lifespan study of the relationship between age-specific neurolipofuscin concentration and natural mortality rate in any organism. In a convenient laboratory animal, the African migratory locust, Locusta migratoria, we find an unusual delayed-onset neurolipofuscin accumulation pattern that is highly correlated with exponentially accelerating age-specific Gompertz-Makeham death rates in both males (r=0.93, p=0.0064) and females (r=0.97, p=0.0052). We then test the conservation of this association by aggregating the locust results with available population-specific data for a range of other terrestrial, freshwater, marine, tropical and temperate arthropods whose longevities span three orders of magnitude. This synthesis shows that the strong association between neurolipofuscin deposition and natural mortality is a phylogenetically and environmentally widespread phenomenon (r=0.96, p < 0.0001). These results highlight neurolipofuscin as a unique and outstanding integral biomarker of ageing. They also offer compelling evidence for the proposal that, in vital organs like the brain, either the accumulation of toxic garbage in the form of lipofuscin itself, or the particular molecular reactions underlying lipofuscinogenesis, including free-radical damage, are the primary events in senescence. PMID:16191601

  6. [Structure of parasitic arthropod communities in forest small mammals].

    PubMed

    Balashov, Iu S

    2004-01-01

    Species composition and structure of ectoparasite arthropod communities were examined all year round six years in the bank vole Clethrionomys glareolus, Ural wood mouse Apodemus uralensis and the common shrew Sorex araneus in forests of the Ilmen'-Volkhov depression. In total, 4500 host samples have been examined and all ectoparasites have been collected. The species composition of ectoparasite community in small mammal species are as follows: the bank vole--29 insect, tick and mite species, the common shrew--23 species, the Ural wood mouse--16 species. In forest biotopes, many temporary ectoparasitic species occur on several host species living in the same habitats under a forest canopy and contacting each other. A parasitic supracommunity in the ecosystem examined has a pool of temporary ectoparasites, which is available for all the community of small mammals. A role of different rodent and shrew species are hosts of insects and ticks changes depending on a density of potential host populations and numerous other environment factors. PMID:15656091

  7. Arthropod phylogeny based on eight molecular loci and morphology

    NASA Technical Reports Server (NTRS)

    Giribet, G.; Edgecombe, G. D.; Wheeler, W. C.

    2001-01-01

    The interrelationships of major clades within the Arthropoda remain one of the most contentious issues in systematics, which has traditionally been the domain of morphologists. A growing body of DNA sequences and other types of molecular data has revitalized study of arthropod phylogeny and has inspired new considerations of character evolution. Novel hypotheses such as a crustacean-hexapod affinity were based on analyses of single or few genes and limited taxon sampling, but have received recent support from mitochondrial gene order, and eye and brain ultrastructure and neurogenesis. Here we assess relationships within Arthropoda based on a synthesis of all well sampled molecular loci together with a comprehensive data set of morphological, developmental, ultrastructural and gene-order characters. The molecular data include sequences of three nuclear ribosomal genes, three nuclear protein-coding genes, and two mitochondrial genes (one protein coding, one ribosomal). We devised new optimization procedures and constructed a parallel computer cluster with 256 central processing units to analyse molecular data on a scale not previously possible. The optimal 'total evidence' cladogram supports the crustacean-hexapod clade, recognizes pycnogonids as sister to other euarthropods, and indicates monophyly of Myriapoda and Mandibulata.

  8. Mineral cycling in soil and litter arthropod food chains. Progress report, November 1, 1980-October 31, 1981

    SciTech Connect

    Crossley, D.A. Jr.

    1980-06-15

    Progress and current status are reported for research projects concerned with mineral element and nutrient dynamics in soil arthropod food chains. Research is performed within the larger context of terrestrial decomposition, in which soil arthropods may act as regulators of nutrient dynamics during decomposition. Research is measuring rates of nutrient accumulation and excretion by using radioactive tracer analogs of nutrients. This year, emphasis has been placed on field work in which soil arthropod population size and nutrients inputs were varied experimentally. The presence of microarthropods in field microcosms increased the mineralization of N and P in each case, but rates were not correlated with arthropod densities. Experiments recently started are using both arthropod and microfloral inhibitors, in open systems on the forest floor, with the objective of quantifying arthropod enhancement of microbial immobilization of nutrients.

  9. The effects of global change on the threat of exotic arthropods and arthropod-borne pathogens to livestock in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arthropod-borne diseases are an important part of the group of foreign animal diseases that command attention from federal, state, and local animal health authorities in the United States because of the potential for adverse local and regional animal health impacts, but also because of possible loss...

  10. Mineral cycling in soil and litter arthropod food chains. Three-year progress report, February 1, 1984-January 31, 1987

    SciTech Connect

    Crossley, D.A. Jr.

    1986-08-29

    This report summarizes progress in a three-year research project on the influence of soil arthropods (mites, collembolans, insects, millipedes and others) upon decomposition rates and nutrient dynamics in decaying vegetable matter. Research has concentrated on two aspects of elemental dynamics in decomposing organic matter: Effects of arthropods on rates of decomposition and nutrient loss (mineralization of carbon and other elements), and arthropod stimulation of microbial immobilization of nutrient elements during decomposition.

  11. Habitat and species identity, not diversity, predict the extent of refuse consumption by urban arthropods.

    PubMed

    Youngsteadt, Elsa; Henderson, Ryanna C; Savage, Amy M; Ernst, Andrew F; Dunn, Robert R; Frank, Steven D

    2015-03-01

    Urban green spaces provide ecosystem services to city residents, but their management is hindered by a poor understanding of their ecology. We examined a novel ecosystem service relevant to urban public health and esthetics: the consumption of littered food waste by arthropods. Theory and data from natural systems suggest that the magnitude and resilience of this service should increase with biological diversity. We measured food removal by presenting known quantities of cookies, potato chips, and hot dogs in street medians (24 sites) and parks (21 sites) in New York City, USA. At the same sites, we assessed ground-arthropod diversity and abiotic conditions, including history of flooding during Hurricane Sandy 7 months prior to the study. Arthropod diversity was greater in parks (on average 11 hexapod families and 4.7 ant species per site), than in medians (nine hexapod families and 2.7 ant species per site). However, counter to our diversity-based prediction, arthropods in medians removed 2-3 times more food per day than did those in parks. We detected no effect of flooding (at 19 sites) on this service. Instead, greater food removal was associated with the presence of the introduced pavement ant (Tetramorium sp. E) and with hotter, drier conditions that may have increased arthropod metabolism. When vertebrates also had access to food, more was removed, indicating that arthropods and vertebrates compete for littered food. We estimate that arthropods alone could remove 4-6.5 kg of food per year in a single street median, reducing its availability to less desirable fauna such as rats. Our results suggest that species identity and habitat may be more relevant than diversity for predicting urban ecosystem services. Even small green spaces such as street medians provide ecosystem services that may complement those of larger habitat patches across the urban landscape. PMID:25463151

  12. Large-scale experimental landscapes reveal distinctive effects of patch shape and connectivity on arthropod communities.

    SciTech Connect

    Orrock, John, L.; Curler, Gregory, R.; Danielson, Brent, J.; Coyle, David. R.

    2011-09-14

    The size, shape, and isolation of habitat patches can affect organism behavior and population dynamics, but little is known about the relative role of shape and connectivity in affecting ecological communities at large spatial scales. Using six sampling sessions from July 2001 until August 2002, we collected 33,685 arthropods throughout seven 12-ha experimental landscapes consisting of clear-cut patches surrounded by a matrix of mature pine forest. Patches were explicitly designed to manipulate connectivity (via habitat corridors) independently of area and edge effects. We found that patch shape, rather than connectivity, affected ground-dwelling arthropod richness and beta diversity (i.e. turnover of genera among patches). Arthropod communities contained fewer genera and exhibited less turnover in high-edge connected and high-edge unconnected patches relative to low-edge unconnected patches of similar area. Connectivity, rather than patch shape, affected the evenness of ground-dwelling arthropod communities; regardless of patch shape, high-edge connected patches had lower evenness than low- or high-edge unconnected patches. Among the most abundant arthropod orders, increased richness in low-edge unconnected patches was largely due to increased richness of Coleoptera, whereas Hymenoptera played an important role in the lower evenness in connected patches and patterns of turnover. These findings suggest that anthropogenic habitat alteration can have distinct effects on ground-dwelling arthropod communities that arise due to changes in shape and connectivity. Moreover, this work suggests that corridors, which are common conservation tools that change both patch shape and connectivity, can have multiple effects on arthropod communities via different mechanisms, and each effect may alter components of community structure.

  13. The Relationship between Physical Function and Postural Sway during Local Vibratory Stimulation of Middle-aged People in the Standing Position

    PubMed Central

    Ito, Tadashi; Sakai, Yoshihito; Kubo, Akira; Yamazaki, Kazunori; Ohno, Yasuo; Nakamura, Eishi; Sato, Noritaka; Morita, Yoshifumi

    2014-01-01

    [Purpose] The purpose of this study was to examine the relationship between physical function and postural sway during local vibratory stimulation of middle-aged subjects in an upright position. [Subjects] The subjects were 25 healthy community-dwelling middle-aged people. [Methods] We measured postural sway using a Wii board while vibratory stimulations of 30, 60, or 240 Hz were applied to the subjects’ lumbar multifidus or gastrocnemius muscles. Physical function was evaluated by 5-m usual gait speed and grip strength. [Results] Gait speed was strongly correlated to the anteroposterior body sway in the upright position during 30 Hz gastrocnemius muscles vibration (GMV). [Conclusion] Postural sway during 30 Hz GMV was strongly associated with gait speed and showed a posterior displacement. These findings show that the lower leg’s response to balance control under 30 Hz proprioceptive stimulation might be a good indicator of declining gait function. PMID:25364130

  14. Indirect suppression of photosynthesis on individual leaves by arthropod herbivory

    PubMed Central

    Nabity, Paul D.; Zavala, Jorge A.; DeLucia, Evan H.

    2009-01-01

    Background Herbivory reduces leaf area, disrupts the function of leaves, and ultimately alters yield and productivity. Herbivore damage to foliage typically is assessed in the field by measuring the amount of leaf tissue removed and disrupted. This approach assumes the remaining tissues are unaltered, and plant photosynthesis and water balance function normally. However, recent application of thermal and fluorescent imaging technologies revealed that alterations to photosynthesis and transpiration propagate into remaining undamaged leaf tissue. Scope and Conclusions This review briefly examines the indirect effects of herbivory on photosynthesis, measured by gas exchange or chlorophyll fluorescence, and identifies four mechanisms contributing to the indirect suppression of photosynthesis in remaining leaf tissues: severed vasculature, altered sink demand, defence-induced autotoxicity, and defence-induced down-regulation of photosynthesis. We review the chlorophyll fluorescence and thermal imaging techniques used to gather layers of spatial data and discuss methods for compiling these layers to achieve greater insight into mechanisms contributing to the indirect suppression of photosynthesis. We also elaborate on a few herbivore-induced gene-regulating mechanisms which modulate photosynthesis and discuss the difficult nature of measuring spatial heterogeneity when combining fluorescence imaging and gas exchange technology. Although few studies have characterized herbivore-induced indirect effects on photosynthesis at the leaf level, an emerging literature suggests that the loss of photosynthetic capacity following herbivory may be greater than direct loss of photosynthetic tissues. Depending on the damage guild, ignoring the indirect suppression of photosynthesis by arthropods and other organisms may lead to an underestimate of their physiological and ecological impacts. PMID:18660492

  15. Do Scaphoideus titanus (Hemiptera: Cicadellidae) nymphs use vibrational communication?

    NASA Astrophysics Data System (ADS)

    Chuche, Julien; Thiéry, Denis; Mazzoni, Valerio

    2011-07-01

    Small Auchenorrhyncha use substrate-borne vibrations to communicate. Although this behaviour is well known in adult leafhoppers, so far no studies have been published on nymphs. Here we checked the occurrence of vibrational communication in Scaphoideus titanus (Hemiptera: Cicadellidae) nymphs as a possible explanation of their aggregative distributions on host plants. We studied possible vibratory emissions of isolated and grouped nymphs, as well as their behavioural responses to vibration stimuli that simulated presence of conspecifics, to disturbance noise, white noise and predator spiders. None of our synthetic stimuli or pre-recorded substrate vibrations from nymphs elicited specific vibration responses and only those due to grooming or mechanical contacts of the insect with the leaf were recorded. Thus, S. titanus nymphs showed to not use species-specific vibrations neither for intra- nor interspecific communication and also did not produce alarm vibrations when facing potential predators. We conclude that their aggregative behaviour is independent from a vibrational communication.

  16. Disturbance and recovery of salt marsh arthropod communities following BP Deepwater Horizon oil spill.

    PubMed

    McCall, Brittany D; Pennings, Steven C

    2012-01-01

    Oil spills represent a major environmental threat to coastal wetlands, which provide a variety of critical ecosystem services to humanity. The U.S. Gulf of Mexico is a hub of oil and gas exploration activities that historically have impacted intertidal habitats such as salt marsh. Following the BP Deepwater Horizon oil spill, we sampled the terrestrial arthropod community and marine invertebrates found in stands of Spartina alterniflora, the most abundant plant in coastal salt marshes. Sampling occurred in 2010 as oil was washing ashore and a year later in 2011. In 2010, intertidal crabs and terrestrial arthropods (insects and spiders) were suppressed by oil exposure even in seemingly unaffected stands of plants; however, Littoraria snails were unaffected. One year later, crab and arthropods had largely recovered. Our work is the first attempt that we know of assessing vulnerability of the salt marsh arthropod community to oil exposure, and it suggests that arthropods are both quite vulnerable to oil exposure and quite resilient, able to recover from exposure within a year if host plants remain healthy. PMID:22412916

  17. Oak tree canker disease supports arthropod diversity in a natural ecosystem.

    PubMed

    Lee, Yong-Bok; An, Su Jung; Park, Chung Gyoo; Kim, Jinwoo; Han, Sangjo; Kwak, Youn-Sig

    2014-03-01

    Microorganisms have many roles in nature. They may act as decomposers that obtain nutrients from dead materials, while some are pathogens that cause diseases in animals, insects, and plants. Some are symbionts that enhance plant growth, such as arbuscular mycorrhizae and nitrogen fixation bacteria. However, roles of plant pathogens and diseases in natural ecosystems are still poorly understood. Thus, the current study addressed this deficiency by investigating possible roles of plant diseases in natural ecosystems, particularly, their positive effects on arthropod diversity. In this study, the model system was the oak tree (Quercus spp.) and the canker disease caused by Annulohypoxylon truncatum, and its effects on arthropod diversity. The oak tree site contained 44 oak trees; 31 had canker disease symptoms while 13 were disease-free. A total of 370 individual arthropods were detected at the site during the survey period. The arthropods belonged to 25 species, 17 families, and seven orders. Interestingly, the cankered trees had significantly higher biodiversity and richness compared with the canker-free trees. This study clearly demonstrated that arthropod diversity was supported by the oak tree canker disease. PMID:25288984

  18. Oak Tree Canker Disease Supports Arthropod Diversity in a Natural Ecosystem

    PubMed Central

    Lee, Yong-Bok; An, Su Jung; Park, Chung Gyoo; Kim, Jinwoo; Han, Sangjo; Kwak, Youn-Sig

    2014-01-01

    Microorganisms have many roles in nature. They may act as decomposers that obtain nutrients from dead materials, while some are pathogens that cause diseases in animals, insects, and plants. Some are symbionts that enhance plant growth, such as arbuscular mycorrhizae and nitrogen fixation bacteria. However, roles of plant pathogens and diseases in natural ecosystems are still poorly understood. Thus, the current study addressed this deficiency by investigating possible roles of plant diseases in natural ecosystems, particularly, their positive effects on arthropod diversity. In this study, the model system was the oak tree (Quercus spp.) and the canker disease caused by Annulohypoxylon truncatum, and its effects on arthropod diversity. The oak tree site contained 44 oak trees; 31 had canker disease symptoms while 13 were disease-free. A total of 370 individual arthropods were detected at the site during the survey period. The arthropods belonged to 25 species, 17 families, and seven orders. Interestingly, the cankered trees had significantly higher biodiversity and richness compared with the canker-free trees. This study clearly demonstrated that arthropod diversity was supported by the oak tree canker disease. PMID:25288984

  19. Surviving in a frozen desert: environmental stress physiology of terrestrial Antarctic arthropods.

    PubMed

    Teets, Nicholas M; Denlinger, David L

    2014-01-01

    Abiotic stress is one of the primary constraints limiting the range and success of arthropods, and nowhere is this more apparent than Antarctica. Antarctic arthropods have evolved a suite of adaptations to cope with extremes in temperature and water availability. Here, we review the current state of knowledge regarding the environmental physiology of terrestrial arthropods in Antarctica. To survive low temperatures, mites and Collembola are freeze-intolerant and rely on deep supercooling, in some cases supercooling below -30°C. Also, some of these microarthropods are capable of cryoprotective dehydration to extend their supercooling capacity and reduce the risk of freezing. In contrast, the two best-studied Antarctic insects, the midges Belgica antarctica and Eretmoptera murphyi, are freeze-tolerant year-round and rely on both seasonal and rapid cold-hardening to cope with decreases in temperature. A common theme among Antarctic arthropods is extreme tolerance of dehydration; some accomplish this by cuticular mechanisms to minimize water loss across their cuticle, while a majority have highly permeable cuticles but tolerate upwards of 50-70% loss of body water. Molecular studies of Antarctic arthropod stress physiology are still in their infancy, but several recent studies are beginning to shed light on the underlying mechanisms that govern extreme stress tolerance. Some common themes that are emerging include the importance of cuticular and cytoskeletal rearrangements, heat shock proteins, metabolic restructuring and cell recycling pathways as key mediators of cold and water stress in the Antarctic. PMID:24353207

  20. Incidence of a new sex-ratio-distorting endosymbiotic bacterium among arthropods.

    PubMed Central

    Weeks, Andrew R; Velten, Robert; Stouthamer, Richard

    2003-01-01

    Many intracellular micro-organisms are now known to cause reproductive abnormalities and other phenomena in their hosts. The endosymbiont Wolbachia is the best known of these reproductive manipulators owing to its extremely high incidence among arthropods and the diverse host effects it has been implicated as causing. However, recent evidence suggests that another intracellular bacterium, a Cytophaga-like organism (CLO), may also induce several reproductive effects in its hosts. Here, we present the first survey of arthropod hosts for infection by the CLO. We use a sensitive hemi-nested polymerase chain reaction method to screen 223 species from 20 arthropod orders for infection by the CLO and Wolbachia. The results indicate that, although not as prevalent as Wolbachia, the CLO infects a significant number of arthropod hosts (ca. 7.2%). In addition, double infections of the CLO and Wolbachia were found in individuals of seven arthropod species. Sequencing analysis of the 16S rDNA region of the CLO indicates evidence for horizontal transmission of the CLO strains. We discuss these results with reference to future studies on host effects induced by intracellular micro-organisms. PMID:12964989

  1. Modification and Application of a Leaf Blower-vac for Field Sampling of Arthropods.

    PubMed

    Zou, Yi; van Telgen, Mario D; Chen, Junhui; Xiao, Haijun; de Kraker, Joop; Bianchi, Felix J J A; van der Werf, Wopke

    2016-01-01

    Rice fields host a large diversity of arthropods, but investigating their population dynamics and interactions is challenging. Here we describe the modification and application of a leaf blower-vac for suction sampling of arthropod populations in rice. When used in combination with an enclosure, application of this sampling device provides absolute estimates of the populations of arthropods as numbers per standardized sampling area. The sampling efficiency depends critically on the sampling duration. In a mature rice crop, a two-minute sampling in an enclosure of 0.13 m(2) yields more than 90% of the arthropod population. The device also allows sampling of arthropods dwelling on the water surface or the soil in rice paddies, but it is not suitable for sampling fast flying insects, such as predatory Odonata or larger hymenopterous parasitoids. The modified blower-vac is simple to construct, and cheaper and easier to handle than traditional suction sampling devices, such as D-vac. The low cost makes the modified blower-vac also accessible to researchers in developing countries. PMID:27584040

  2. Tuning the white light spectrum of light emitting diode lamps to reduce attraction of nocturnal arthropods.

    PubMed

    Longcore, Travis; Aldern, Hannah L; Eggers, John F; Flores, Steve; Franco, Lesly; Hirshfield-Yamanishi, Eric; Petrinec, Laina N; Yan, Wilson A; Barroso, André M

    2015-05-01

    Artificial lighting allows humans to be active at night, but has many unintended consequences, including interference with ecological processes, disruption of circadian rhythms and increased exposure to insect vectors of diseases. Although ultraviolet and blue light are usually most attractive to arthropods, degree of attraction varies among orders. With a focus on future indoor lighting applications, we manipulated the spectrum of white lamps to investigate the influence of spectral composition on number of arthropods attracted. We compared numbers of arthropods captured at three customizable light-emitting diode (LED) lamps (3510, 2704 and 2728 K), two commercial LED lamps (2700 K), two commercial compact fluorescent lamps (CFLs; 2700 K) and a control. We configured the three custom LEDs to minimize invertebrate attraction based on published attraction curves for honeybees and moths. Lamps were placed with pan traps at an urban and two rural study sites in Los Angeles, California. For all invertebrate orders combined, our custom LED configurations were less attractive than the commercial LED lamps or CFLs of similar colour temperatures. Thus, adjusting spectral composition of white light to minimize attracting nocturnal arthropods is feasible; not all lights with the same colour temperature are equally attractive to arthropods. PMID:25780237

  3. Tuning the white light spectrum of light emitting diode lamps to reduce attraction of nocturnal arthropods

    PubMed Central

    Longcore, Travis; Aldern, Hannah L.; Eggers, John F.; Flores, Steve; Franco, Lesly; Hirshfield-Yamanishi, Eric; Petrinec, Laina N.; Yan, Wilson A.; Barroso, André M.

    2015-01-01

    Artificial lighting allows humans to be active at night, but has many unintended consequences, including interference with ecological processes, disruption of circadian rhythms and increased exposure to insect vectors of diseases. Although ultraviolet and blue light are usually most attractive to arthropods, degree of attraction varies among orders. With a focus on future indoor lighting applications, we manipulated the spectrum of white lamps to investigate the influence of spectral composition on number of arthropods attracted. We compared numbers of arthropods captured at three customizable light-emitting diode (LED) lamps (3510, 2704 and 2728 K), two commercial LED lamps (2700 K), two commercial compact fluorescent lamps (CFLs; 2700 K) and a control. We configured the three custom LEDs to minimize invertebrate attraction based on published attraction curves for honeybees and moths. Lamps were placed with pan traps at an urban and two rural study sites in Los Angeles, California. For all invertebrate orders combined, our custom LED configurations were less attractive than the commercial LED lamps or CFLs of similar colour temperatures. Thus, adjusting spectral composition of white light to minimize attracting nocturnal arthropods is feasible; not all lights with the same colour temperature are equally attractive to arthropods. PMID:25780237

  4. An armoured Cambrian lobopodian from China with arthropod-like appendages.

    PubMed

    Liu, Jianni; Steiner, Michael; Dunlop, Jason A; Keupp, Helmut; Shu, Degan; Ou, Qiang; Han, Jian; Zhang, Zhifei; Zhang, Xingliang

    2011-02-24

    Cambrian fossil Lagerstätten preserving soft-bodied organisms have contributed much towards our understanding of metazoan origins. Lobopodians are a particularly interesting group that diversified and flourished in the Cambrian seas. Resembling 'worms with legs', they have long attracted much attention in that they may have given rise to both Onychophora (velvet worms) and Tardigrada (water bears), as well as to arthropods in general. Here we describe Diania cactiformis gen. et sp. nov. as an 'armoured' lobopodian from the Chengjiang fossil Lagerstätte (Cambrian Stage 3), Yunnan, southwestern China. Although sharing features with other typical lobopodians, it is remarkable for possessing robust and probably sclerotized appendages, with what appear to be articulated elements. In terms of limb morphology it is therefore closer to the arthropod condition, to our knowledge, than any lobopodian recorded until now. Phylogenetic analysis recovers it in a derived position, close to Arthropoda; thus, it seems to belong to a grade of organization close to the point of becoming a true arthropod. Further, D. cactiformis could imply that arthropodization (sclerotization of the limbs) preceded arthrodization (sclerotization of the body). Comparing our fossils with other lobopodian appendage morphologies--see Kerygmachela, Jianshanopodia and Megadictyon--reinforces the hypothesis that the group as a whole is paraphyletic, with different taxa expressing different grades of arthropodization. PMID:21350485

  5. The origins of the arthropod nervous system: insights from the Onychophora.

    PubMed

    Whitington, Paul M; Mayer, Georg

    2011-05-01

    A revision of evolutionary relationships of the Arthropoda has provided fresh impetus to tracing the origins of the nervous system of this group of animals: other members of the Ecdysozoa possess a markedly different type of nervous system from both the arthropods and the annelid worms, with which they were previously grouped. Given their status as favoured sister taxon of the arthropods, Onychophora (velvet worms) are a key group for understanding the evolutionary changes that have taken place in the panarthropod (Arthropoda + Onychophora + Tardigrada) lineage. This article reviews our current knowledge of the structure and development of the onychophoran nervous system. The picture that emerges from these studies is that the nervous system of the panarthropod ancestor was substantially different from that of modern arthropods: this animal probably possessed a bipartite, rather than a tripartite brain; its nerve cord displayed only a limited degree of segmentation; and neurons were more numerous but more uniform in morphology than in living arthropods. These observations suggest an evolutionary scenario, by which the arthropod nervous system evolved from a system of orthogonally crossing nerve tracts present in both a presumed protostome ancestor and many extant worm-like invertebrates, including the onychophorans. PMID:21315833

  6. Impact of chemically contaminated sewage sludge on the collard arthropod community

    SciTech Connect

    Culliney, T.W.; Pimentel, D.; Lisk, D.J.

    1986-08-01

    Stress effects on a terrestrial arthropod community were evident in a study of collards grown in soil amended with chemically contaminated sewage sludge. Plant growth in the contaminated sludge was significantly reduced compared with growth in plots treated with relatively uncontaminated sludge from two small towns or with mature alone. Population densities of major arthropod taxa tended to be lower in plots of contaminated sludge than they were in uncontaminated sludge and manure plots. Species richness and diversity were also reduced in contaminated-sludge plots compared with those of uncontaminated sludge and manure treatments. In general, few differences were observed in plant growth and arthropod numbers between the uncontaminated-sludge treatment, or uncontaminated sludge treated with cadmium or with the insecticide dieldrin. Because cadmium and dieldrin were applied at dosages of cadmium and polychlorinated biphenyls (PCB's) found in the contaminated sludge, results suggested that these two toxins were not responsible for the effects on plants and arthropods observed in the contaminated-sludge treatment. Results of this study indicated the potential for sludge-borne contaminants to suppress growth in crop plants and reduce abundance of their associated arthropods.

  7. Seasonal Distribution and Diversity of Ground Arthropods in Microhabitats Following a Shrub Plantation Age Sequence in Desertified Steppe

    PubMed Central

    Liu, Rentao; Zhu, Fan; Song, Naiping; Yang, Xinguo; Chai, Yongqing

    2013-01-01

    In desertified regions, shrub-dominated patches are important microhabitats for ground arthropod assemblages. As shrub age increases, soil, vegetation and microbiological properties can change remarkably and spontaneously across seasons. However, relatively few studies have analyzed how ground arthropods respond to the microhabitats created by shrubs of different plantation ages across seasons. Using 6, 15, 24 and 36 year-old plantations of re-vegetated shrubs (Caragana koushinskii) in the desert steppe of northwestern China as a model system, we sampled ground arthropod communities using a pitfall trapping method in the microhabitats under shrubs and in the open areas between shrubs, during the spring, summer and autumn. The total ground arthropod assemblage was dominated by Carabidae, Melolonthidae, Curculionidae, Tenebrionidae and Formicidae that were affected by plantation age, seasonal changes, or the interaction between these factors, with the later two groups also influenced by microhabitat. Overall, a facilitative effect was observed, with more arthropods and a greater diversity found under shrubs as compared to open areas, but this was markedly affected by seasonal changes. There was a high degree of similarity in arthropod assemblages and diversity between microhabitats in summer and autumn. Shrub plantation age significantly influenced the distribution of the most abundant groups, and also the diversity indices of the ground arthropods. However, there was not an overall positive relationship between shrub age and arthropod abundance, richness or diversity index. The influence of plantation age on arthropod communities was also affected by seasonal changes. From spring through summer to autumn, community indices of ground arthropods tended to decline, and a high degree of similarity in these indices (with fluctuation) was observed among different ages of shrub plantation in autumn. Altogether the recovery of arthropod communities was markedly affected by

  8. Analysis and design of a 3rd order velocity-controlled closed-loop for MEMS vibratory gyroscopes.

    PubMed

    Wu, Huan-ming; Yang, Hai-gang; Yin, Tao; Jiao, Ji-wei

    2013-01-01

    The time-average method currently available is limited to analyzing the specific performance of the automatic gain control-proportional and integral (AGC-PI) based velocity-controlled closed-loop in a micro-electro-mechanical systems (MEMS) vibratory gyroscope, since it is hard to solve nonlinear functions in the time domain when the control loop reaches to 3rd order. In this paper, we propose a linearization design approach to overcome this limitation by establishing a 3rd order linear model of the control loop and transferring the analysis to the frequency domain. Order reduction is applied on the built linear model's transfer function by constructing a zero-pole doublet, and therefore mathematical expression of each control loop's performance specification is obtained. Then an optimization methodology is summarized, which reveals that a robust, stable and swift control loop can be achieved by carefully selecting the system parameters following a priority order. Closed-loop drive circuits are designed and implemented using 0.35 μm complementary metal oxide semiconductor (CMOS) process, and experiments carried out on a gyroscope prototype verify the optimization methodology that an optimized stability of the control loop can be achieved by constructing the zero-pole doublet, and disturbance rejection capability (D.R.C) of the control loop can be improved by increasing the integral term. PMID:24051522

  9. Acute effects of whole-body vibration on neuromuscular responses in older individuals: implications for prescription of vibratory stimulation.

    PubMed

    Marín, Pedro J; Herrero, Azael J; García-López, David; Rhea, Matthew R; López-Chicharro, José; González-Gallego, Javier; Garatachea, Nuria

    2012-01-01

    The aim of this study was to analyze surface electromyography activity (sEMG) and rating of perceived exertion (RPE) responses in different muscles while standing on a vibrating platform producing oscillations of different frequencies and amplitudes. Twenty community-dwelling older adults (79.6 ± 3.2 years) took part in the research. Subjects were exposed to 12 different vibration treatments of 15 seconds separated by 1 minute of rest in random order to check the influence of frequency (25, 35, and 45 Hz) and amplitude (1 mm [low] and 3.1 mm [high]) vibration on sEMG signal and RPE. Additionally, the use of a soft pad was also examined for its influence on these measures. Three-factor analysis of variance for RPE and both lower and whole-body sEMGs revealed a significant amplitude main effect (p < 0.01), and soft mat effect (p < 0.01), and a significant frequency main effect (p < 0.01). The major findings were that sEMG and RPE increased with the acceleration of the vibration; moreover, the increments of sEMG were highly correlated with RPE. The results of this study suggest that using the RPE method after each exercise would allow exercise and health professionals to assess the intensity levels that correspond to the level of the vibratory program in older adults. PMID:22158143

  10. Step-response of a torsional device with multiple discontinuous non-linearities: Formulation of a vibratory experiment

    NASA Astrophysics Data System (ADS)

    Krak, Michael D.; Dreyer, Jason T.; Singh, Rajendra

    2016-03-01

    A vehicle clutch damper is intentionally designed to contain multiple discontinuous non-linearities, such as multi-staged springs, clearances, pre-loads, and multi-staged friction elements. The main purpose of this practical torsional device is to transmit a wide range of torque while isolating torsional vibration between an engine and transmission. Improved understanding of the dynamic behavior of the device could be facilitated by laboratory measurement, and thus a refined vibratory experiment is proposed. The experiment is conceptually described as a single degree of freedom non-linear torsional system that is excited by an external step torque. The single torsional inertia (consisting of a shaft and torsion arm) is coupled to ground through parallel production clutch dampers, which are characterized by quasi-static measurements provided by the manufacturer. Other experimental objectives address physical dimensions, system actuation, flexural modes, instrumentation, and signal processing issues. Typical measurements show that the step response of the device is characterized by three distinct non-linear regimes (double-sided impact, single-sided impact, and no-impact). Each regime is directly related to the non-linear features of the device and can be described by peak angular acceleration values. Predictions of a simplified single degree of freedom non-linear model verify that the experiment performs well and as designed. Accordingly, the benchmark measurements could be utilized to validate non-linear models and simulation codes, as well as characterize dynamic parameters of the device including its dissipative properties.

  11. Random vibration and the single degree-of-freedom vibratory system: A symbolic quantification of isolation and packaging performance

    SciTech Connect

    Redfield, R.C. . Dept. of Mechanical Engineering)

    1994-01-01

    With twenty years of research, active and semi-active systems have been shown to have certain performance advantages over passive suspensions in certain operating regimes. Chalasani and Redfield and Karnopp have shown that, depending on the performance index and weightings, active control improves performance from little to moderately. There are situations where passive control is quite satisfactory and the complexities and cost of more active means may not be warranted. To further the understanding of the tradeoffs involved and the performance potentials of active suspensions, this paper symbolically quantifies the isolation and stroke performance for a one degree-of-freedom vibratory system subject to a stochastic disturbance input acting through the suspension. The system of this paper models that of tracked vehicles and a class of isolation systems quite well. It also gives insight into low and high frequency performance for two degree-of-freedom systems such as a typical suspension model for automobiles, aircraft, and rail vehicles. Because of the nature of the single degree-of-freedom model, issues of handling cannot be readily addressed in this work. The 1 DOF model does not adequately predict dynamic tire forces. The main contributions of this work are the closed form symbolic solutions developed for optimal suspension response and the demonstration of the marked similarity between the frequency and mean square response of the 1 degree-of-freedom model of this paper and the more involved 2 degree-of-freedom model incorporating a so-called unsprung mass.''

  12. Unilateral contact induced blade/casing vibratory interactions in impellers: Analysis for flexible casings with friction and abradable coating

    NASA Astrophysics Data System (ADS)

    Batailly, Alain; Legrand, Mathias

    2015-07-01

    This contribution addresses the vibratory analysis of unilateral contact induced structural interactions between a bladed impeller and its surrounding flexible casing. It extends the numerical developments exposed in a previous paper to flexible casings. The casing finite element model and the construction of the associated reduced-order model for efficient computations are first exposed in detail along with an extensive presentation of the smoothing strategy implemented on the contact interface. The proposed algorithms embedding unilateral contact conditions together with abradable coating removal are subsequently introduced and validated through a systematic analysis of (1) the nonlinear procedure for the computation of impeller/casing distances, (2) the treatment of three-dimensional friction and contact forces, (3) the correction of the displacements when unilateral contact or abradable removal arises, and (4) the possible hybrid contact scenarii involving localized total removal of the abradable coating. Finally, two illustrative case studies show that the linear interaction condition, commonly considered for the safe design of impellers and casings in turbomachinery, may be advantageously combined with the presented numerical strategy in order to assess the actual importance of predicted critical speeds.

  13. Analysis and Design of a 3rd Order Velocity-Controlled Closed-Loop for MEMS Vibratory Gyroscopes

    PubMed Central

    Wu, Huan-ming; Yang, Hai-gang; Yin, Tao; Jiao, Ji-wei

    2013-01-01

    The time-average method currently available is limited to analyzing the specific performance of the automatic gain control-proportional and integral (AGC-PI) based velocity-controlled closed-loop in a micro-electro-mechanical systems (MEMS) vibratory gyroscope, since it is hard to solve nonlinear functions in the time domain when the control loop reaches to 3rd order. In this paper, we propose a linearization design approach to overcome this limitation by establishing a 3rd order linear model of the control loop and transferring the analysis to the frequency domain. Order reduction is applied on the built linear model's transfer function by constructing a zero-pole doublet, and therefore mathematical expression of each control loop's performance specification is obtained. Then an optimization methodology is summarized, which reveals that a robust, stable and swift control loop can be achieved by carefully selecting the system parameters following a priority order. Closed-loop drive circuits are designed and implemented using 0.35 μm complementary metal oxide semiconductor (CMOS) process, and experiments carried out on a gyroscope prototype verify the optimization methodology that an optimized stability of the control loop can be achieved by constructing the zero-pole doublet, and disturbance rejection capability (D.R.C) of the control loop can be improved by increasing the integral term. PMID:24051522

  14. A substrate energy dissipation mechanism in in-phase and anti-phase micromachined z-axis vibratory gyroscopes

    NASA Astrophysics Data System (ADS)

    Trusov, Alexander A.; Schofield, Adam R.; Shkel, Andrei M.

    2008-09-01

    This paper analyzes energy dissipation mechanisms in vacuum-operated in-phase and anti-phase actuated micromachined z-axis vibratory gyroscopes. The type of actuation is experimentally identified as the key factor to energy dissipation. For in-phase devices, dissipation through the die substrate is the dominant energy loss mechanism. This damping mechanism depends strongly on the die attachment method; rigid die attachment minimizes the loss of energy at the cost of reduced vibrational and stress isolation. For anti-phase actuated devices, dissipation through the substrate is suppressed and immunity to external vibrations is provided. However, even in anti-phase actuated devices fabrication imperfections introduce structural non-symmetry, enabling dissipation of energy through the die substrate due to momentum imbalance. Based on the experimental investigation, an analytical model for energy dissipation through the die substrate is proposed and used to study the effects of the actuation type, die attachment and fabrication imperfections. The limiting Q-factor for in-phase devices is generally below 20 × 103 while Q-factors much higher than 100 × 103 can be achieved with balanced anti-phase actuated gyroscopes.

  15. Changes In CO2 Gas Flux And Soil Temperatures Induced By A Vibratory Seismic Source At Solfatara (Phlegrean Fields, Italy).

    NASA Astrophysics Data System (ADS)

    Vandemeulebrouck, J.; Gresse, M.; Chiodini, G.; Byrdina, S.; Woith, H.; Bruno, P. P.

    2014-12-01

    Solfatara, the most active crater of Phlegrean Fields (Italy) is characterized by a fumarolic activity and an intense diffuse degassing, with 1500 tons of CO2 and > 3000 tons of water vapor released per day. A major part of the emitted water vapor is condensed at the near surface producing a thermal power flux around 100 MW, and contributing substantially to the total water input into the hydrothermal system. On May 2014, during a seismic experiment (RICEN) in the frame of the MED-SUV European project, a Minivib vibratory seismic source was used to generate a frequency modulated seismic signal at different points of Solfatara. We performed CO2 flux measurements at a few meters from the seismic source during the vibrations. In certain points, the vibrations induced a remarkable increase in the CO2 diffuse degassing, with a flux that doubled during the low-frequency seismic vibrations and returned to previous values afterwards. The observed CO2 flux increase could be due to permeability enhancement in the sub-surface soil layers during the seismic vibrations. Close to Fangaia mud pool, we also monitored the soil temperature at different levels above the condensation depth and observed transient temperature changes during the vibrations but also outside the vibration periods. Seismic vibrations likely favor the triggering of thermal instabilities of gravitational or convective origin in the liquid-saturated condensate layer.

  16. Further Examination of the Vibratory Loads Reduction Results from the NASA/ARMY/MIT Active Twist Rotor Test

    NASA Technical Reports Server (NTRS)

    Wilbur, Matthew L.; Yeager, William T., Jr.; Sekula, Martin K.

    2002-01-01

    The vibration reduction capabilities of a model rotor system utilizing controlled, strain-induced blade twisting are examined. The model rotor blades, which utilize piezoelectric active fiber composite actuators, were tested in the NASA Langley Transonic Dynamics Tunnel using open-loop control to determine the effect of active-twist on rotor vibratory loads. The results of this testing have been encouraging, and have demonstrated that active-twist rotor designs offer the potential for significant load reductions in future helicopter rotor systems. Active twist control was found to use less than 1% of the power necessary to operate the rotor system and had a pronounced effect on both rotating- and fixed-system loads, offering reductions in individual harmonic loads of up to 100%. A review of the vibration reduction results obtained is presented, which includes a limited set of comparisons with results generated using the second-generation version of the Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD II) rotorcraft comprehensive analysis.

  17. Seasonal relationships between birds and arthropods in bottomland forest canopy gaps.

    SciTech Connect

    Bowen, Liessa, Thomas

    2004-12-31

    Bowen, Liessa, Thomas. 2004. Seasonal relationships between birds and arthropods in bottomland forest canopy gaps. PhD Dissertation. North Carolina State University. Raleigh, North Carolina. 98pp. I investigated the influence of arthropod availability and vegetation structure on avian habitat use at the center, edge, and adjacent to forest canopy gaps in 2001 and 2002. I used mist-netting and plot counts to estimate abundance of birds using three sizes (0.13, 0.26, and 0.5 ha) of 7-8 year old group-selection timber harvest openings during four seasons (spring migration, breeding, post-breeding, and fall migration) in a bottomland hardwood forest in the Upper Coastal Plain of South Carolina. I used foliage clipping, Malaise trapping, and pitfall trapping to determine arthropod abundance within each habitat, and I used a warm water crop-flush on captured birds to gather information about arthropods eaten. I observed more birds, including forest interior species, forest-edge spedge species, and several individual species, in early-successional canopy gap and gap-edge habitats than in surrounding mature forest during all seasons. I found a significant interaction between season and habitat type for several groups and individual species, suggesting a seasonal shift in habitat use. Captures of all birds, insectivorous birds, foliage- gleaners, ground-gleaners, aerial salliers, Hooded Warbler (Wilsonia citrina), Northern Cardinal (Cardinalis cardinalis), White-eyed Vireo (Vireo griseus), and Black-throated Blue Warbler (Dendroica caerulescens) were positively correlated with understory vegetation density during two or more seasons. I found relationships between insectivorous birds and leaf-dwelling Lepidoptera, insectivorous birds and ground-dwelling arthropods, foliage-gleaning birds and foliage-dwelling arthropods, and aerial salliers and flying arthropods, as well as between individual bird species and arthropods. Relationships were inconsistent, however, with many

  18. Spatial dynamics of understorey insectivorous birds and arthropods in a southeastern Brazilian Atlantic woodlot.

    PubMed

    Manhães, M A; Dias, M M

    2011-02-01

    Spatial distribution and spatial relationships in capture rates of understorey insectivorous birds and density of arthropods were investigated in a patch of upper montane rain forest in Minas Gerais state, southeastern Brazil, from January to December 2004. The composition of the arthropod fauna collected was similar to that reported for other tropical forests, with predominance of Araneae, Coleoptera, Hymenoptera and Hemiptera non-Heteroptera. A total of 26 bird species were captured, among which the more common were Dysithamnus mentalis, Conopophaga lineata, Platyrinchus mystaceus, Basileuterus culicivorus and Sclerurus scansor. Variation in the bird capture rates among sampling net lines were not correlated with arthropod density. Rather, individual analyses of some bird species suggest that spatial distribution of understorey insectivorous birds is better explained by habitat type. PMID:21437393

  19. Molecular methods for arthropod bloodmeal identification and applications to ecological and vector-borne disease studies.

    PubMed

    Kent, Rebekah J

    2009-01-01

    DNA-based methods have greatly enhanced the sensitivity and specificity of hematophagous arthropod bloodmeal identification. A variety of methods have been applied to study the blood-feeding behaviour of mosquitoes, ticks, black flies and other blood-feeding arthropods as it relates to host-parasite interactions and pathogen transmission. Overviews of the molecular techniques used for bloodmeal identification, their advantages, disadvantages and applications are presented for DNA sequencing, group-specific polymerase chain reaction primers, restriction fragment length polymorphism, real-time polymerase chain reaction, heteroduplex analysis, reverse line-blot hybridization and DNA profiling. Technical challenges to bloodmeal identification including digestion and analysis of mixed bloodmeals are discussed. Analysis of bloodmeal identification results remains a challenge to the field, particularly with regard to incorporation of vertebrate census and ecology data. Future research directions for molecular analysis of arthropod bloodmeals are proposed. PMID:21564560

  20. Tiny individuals attached to a new Silurian arthropod suggest a unique mode of brood care

    NASA Astrophysics Data System (ADS)

    Briggs, Derek E. G.; Siveter, Derek J.; Siveter, David J.; Sutton, Mark D.

    2016-04-01

    The ˜430-My-old Herefordshire, United Kingdom, Lagerstätte has yielded a diversity of remarkably preserved invertebrates, many of which provide fundamental insights into the evolutionary history and ecology of particular taxa. Here we report a new arthropod with 10 tiny arthropods tethered to its tergites by long individual threads. The head of the host, which is covered by a shield that projects anteriorly, bears a long stout uniramous antenna and a chelate limb followed by two biramous appendages. The trunk comprises 11 segments, all bearing limbs and covered by tergites with long slender lateral spines. A short telson bears long parallel cerci. Our phylogenetic analysis resolves the new arthropod as a stem-group mandibulate. The evidence suggests that the tethered individuals are juveniles and the association represents a complex brooding behavior. Alternative possibilities—that the tethered individuals represent a different epizoic or parasitic arthropod—appear less likely.

  1. Preservation of three-dimensional anatomy in phosphatized fossil arthropods enriches evolutionary inference

    PubMed Central

    Schwermann, Achim H; dos Santos Rolo, Tomy; Caterino, Michael S; Bechly, Günter; Schmied, Heiko; Baumbach, Tilo; van de Kamp, Thomas

    2016-01-01

    External and internal morphological characters of extant and fossil organisms are crucial to establishing their systematic position, ecological role and evolutionary trends. The lack of internal characters and soft-tissue preservation in many arthropod fossils, however, impedes comprehensive phylogenetic analyses and species descriptions according to taxonomic standards for Recent organisms. We found well-preserved three-dimensional anatomy in mineralized arthropods from Paleogene fissure fillings and demonstrate the value of these fossils by utilizing digitally reconstructed anatomical structure of a hister beetle. The new anatomical data facilitate a refinement of the species diagnosis and allowed us to reject a previous hypothesis of close phylogenetic relationship to an extant congeneric species. Our findings suggest that mineralized fossils, even those of macroscopically poor preservation, constitute a rich but yet largely unexploited source of anatomical data for fossil arthropods. DOI: http://dx.doi.org/10.7554/eLife.12129.001 PMID:26854367

  2. Function and hydrostatics in the telson of the Burgess Shale arthropod Burgessia

    PubMed Central

    Lin, Jih-Pai

    2009-01-01

    Burgessia bella is a characteristic Burgess Shale arthropod (508 Ma), but the unusual preservation of its telson in both straight and bent modes leads to contradictory interpretations of its function. A reinvestigation of the fossil material, including burial attitudes, combined with a comparison with the decay sequence and mechanics of the telson in living Limulus, demonstrates that the telson of Burgessia was flexible in its relaxed state but could be stiffened in life. Evidence of fluid within the telson indicates that this manoeuvrability was achieved by changes in hydrostatic pressure and muscular control. The dual mode in the Burgessia telson is, to my knowledge, the first documented among fossil arthropods. It indicates that the requirement for a rigid telson, which is resolved by a thick sclerotized cuticle in most arthropods, may first have been achieved by hydrostatic means. PMID:19324649

  3. A framework for assessment and monitoring of arthropods in a lowland tropical forest.

    PubMed

    Finnamore, Albert; Alonso, Alfonso; Santisteban, Jose; Cordova, Saida; Valencia, Gorky; de la Cruz, Alicia; Polo, Roberto

    2002-05-01

    By applying principles of adaptive management, and by using the valuable information that arthropods provide from assessment and monitoring programs, managers can identify and reduce possible impacts on biodiversity in development projects. In 1996, the Smithsonian Institution's Monitoring and Assessment of Biodiversity program worked together with Shell Prospecting and Development Peru to establish an adaptive management program to protect biodiversity in a natural gas exploration project in a Peruvian rainforest. In this paper, we outlined the conceptual steps involved in establishing an assessment and monitoring program for arthropods, including setting objectives, evaluating the results and making decisions. We also present the results of the assessment using some of groups of arthropods, and summarize the steps taken to identify appropriate groups for monitoring. PMID:12125749

  4. Preservation of three-dimensional anatomy in phosphatized fossil arthropods enriches evolutionary inference.

    PubMed

    Schwermann, Achim H; Dos Santos Rolo, Tomy; Caterino, Michael S; Bechly, Günter; Schmied, Heiko; Baumbach, Tilo; van de Kamp, Thomas

    2016-01-01

    External and internal morphological characters of extant and fossil organisms are crucial to establishing their systematic position, ecological role and evolutionary trends. The lack of internal characters and soft-tissue preservation in many arthropod fossils, however, impedes comprehensive phylogenetic analyses and species descriptions according to taxonomic standards for Recent organisms. We found well-preserved three-dimensional anatomy in mineralized arthropods from Paleogene fissure fillings and demonstrate the value of these fossils by utilizing digitally reconstructed anatomical structure of a hister beetle. The new anatomical data facilitate a refinement of the species diagnosis and allowed us to reject a previous hypothesis of close phylogenetic relationship to an extant congeneric species. Our findings suggest that mineralized fossils, even those of macroscopically poor preservation, constitute a rich but yet largely unexploited source of anatomical data for fossil arthropods. PMID:26854367

  5. Feeding and the rhodopsin family g-protein coupled receptors in nematodes and arthropods.

    PubMed

    Cardoso, João C R; Félix, Rute C; Fonseca, Vera G; Power, Deborah M

    2012-01-01

    In vertebrates, receptors of the rhodopsin G-protein coupled superfamily (GPCRs) play an important role in the regulation of feeding and energy homeostasis and are activated by peptide hormones produced in the brain-gut axis. These peptides regulate appetite and energy expenditure by promoting or inhibiting food intake. Sequence and function homologs of human GPCRs involved in feeding exist in the nematode roundworm, Caenorhabditis elegans (C. elegans), and the arthropod fruit fly, Drosophila melanogaster (D. melanogaster), suggesting that the mechanisms that regulate food intake emerged early and have been conserved during metazoan radiation. Nematodes and arthropods are the most diverse and successful animal phyla on Earth. They can survive in a vast diversity of environments and have acquired distinct life styles and feeding strategies. The aim of the present review is to investigate if this diversity has affected the evolution of invertebrate GPCRs. Homologs of the C. elegans and D. melanogaster rhodopsin receptors were characterized in the genome of other nematodes and arthropods and receptor evolution compared. With the exception of bombesin receptors (BBR) that are absent from nematodes, a similar gene complement was found. In arthropods, rhodopsin GPCR evolution is characterized by species-specific gene duplications and deletions and in nematodes by gene expansions in species with a free-living stage and gene deletions in representatives of obligate parasitic taxa. Based upon variation in GPCR gene number and potentially divergent functions within phyla we hypothesize that life style and feeding diversity practiced by nematodes and arthropods was one factor that contributed to rhodopsin GPCR gene evolution. Understanding how the regulation of food intake has evolved in invertebrates will contribute to the development of novel drugs to control nematodes and arthropods and the pests and diseases that use them as vectors. PMID:23264768

  6. Elevated atmospheric CO2 alters the arthropod community in a forest understory

    NASA Astrophysics Data System (ADS)

    Hamilton, Jason; Zangerl, Arthur R.; Berenbaum, May R.; Sparks, Jed P.; Elich, Lauren; Eisenstein, Alissa; DeLucia, Evan H.

    2012-08-01

    The objective of this study was to determine the extent to which overall population sizes and community composition of arthropods in a naturally occurring forest understory are altered by elevated CO2. The Free Air Concentration Enrichment (FACE) method was used to fumigate large, replicated plots in the Piedmont region of North Carolina, USA to achieve the CO2 concentration predicted for 2050 (˜580 μl l-1). In addition, the extent to which unrestricted herbivorous arthropods were spatially delimited in their resource acquisition was determined. Stable isotope data for spiders (δ13C and δ15N) were collected in ambient and elevated CO2 plots and analyzed to determine whether their prey species moved among plots. Elevated CO2 had no effect on total arthropod numbers but had a large effect on the composition of the arthropod community. Insects collected in our samples were identified to a level that allowed for an assignment of trophic classification (generally to family). For the groups of insects sensitive to atmospheric gas composition, there was an increase in the numbers of individuals collected in primarily predaceous orders (Araneae and Hymenoptera; from 60% to more than 150%) under elevated CO2 and a decrease in the numbers in primarily herbivorous orders (Lepidoptera and Coleoptera; from -30 to -45%). Isotopic data gave no indication that the treatment plots represented a "boundary" to the movement of insects or that there were distinct and independent insect populations inside and outside the treatment plots. A simple two-ended mixing model estimates 55% of the carbon and nitrogen in spider biomass originated external to the elevated CO2 plots. In addition to changes in insect performance, decreases in herbivorous arthropods and increases in predaceous arthropods may also be factors involved in reduced herbivory under elevated CO2 in this forest.

  7. Habitat Heterogeneity Affects Plant and Arthropod Species Diversity and Turnover in Traditional Cornfields.

    PubMed

    Martínez, Eliana; Rös, Matthias; Bonilla, María Argenis; Dirzo, Rodolfo

    2015-01-01

    The expansion of the agricultural frontier by the clearing of remnant forests has led to human-dominated landscape mosaics. Previous studies have evaluated the effect of these landscape mosaics on arthropod diversity at local spatial scales in temperate and tropical regions, but little is known about fragmentation effects in crop systems, such as the complex tropical traditional crop systems that maintain a high diversity of weeds and arthropods in low-Andean regions. To understand the factors that influence patterns of diversity in human-dominated landscapes, we investigate the effect of land use types on plant and arthropod diversity in traditionally managed cornfields, via surveys of plants and arthropods in twelve traditional cornfields in the Colombian Andes. We estimated alpha and beta diversity to analyze changes in diversity related to land uses within a radius of 100 m to 1 km around each cornfield. We observed that forests influenced alpha diversity of plants, but not of arthropods. Agricultural lands had a positive relationship with plants and herbivores, but a negative relationship with predators. Pastures positively influenced the diversity of plants and arthropods. In addition, forest cover seemed to influence changes in plant species composition and species turnover of herbivore communities among cornfields. The dominant plant species varied among fields, resulting in high differentiation of plant communities. Predator communities also exhibited high turnover among cornfields, but differences in composition arose mainly among rare species. The crop system evaluated in this study represents a widespread situation in the tropics, therefore, our results can be of broad significance. Our findings suggest that traditional agriculture may not homogenize biological communities, but instead could maintain the regional pool of species through high beta diversity. PMID:26197473

  8. A Comparison of Conservation Reserve Program Habitat Plantings with Respect to Arthropod Prey for Grassland Birds

    USGS Publications Warehouse

    McIntyre, N.E.; Thompson, Thomas R.

    2003-01-01

    The Conservation Reserve Program (CRP) was designed to reduce soil erosion and curb agricultural overproduction by converting highly erodible agricultural land to various forms of perennial habitat. It has had an incidental benefit of providing habitat for wildlife and has been beneficial in reversing population declines of several grassland bird species. However, the mechanisms behind these reversals remain unknown. One such mechanism may be differences in food availability on CRP vs. non-CRP land or between different types of CRP. The influence of CRP habitat type on the abundance of arthropod prey used by grassland birds has not been previously explored. We compared the abundance and diversity of arthropods among four CRP habitat types in Texas [replicated plots of exotic lovegrass (Eragrostis curvula), Old World bluestem (Bothriochloa ischaemum), mixed native grasses with buffalograss (Buchloe?? dactyloides) and mixed native grasses without buffalograss] and native shortgrass prairie. Attention was focused on adult and juvenile spiders (Order Araneae), beetles (Coleoptera), orthopterans (Orthroptera: grasshoppers and crickets) and lepidopterans (Lepidoptera: butterflies and moths), as these taxa are the primary prey items of grassland birds during the breeding season. Arthropod diversity and abundance were higher on indigenous prairie compared to CRP, reflecting differences in vegetative diversity and structure, but there were no differences in arthropod richness or abundance among CRP types. These results indicate that, although CRP is not equivalent to native prairie in terms of vegetation or arthropod diversity, CRP lands do support arthropod prey for grassland birds. More direct assays of the survivorship and fitness of birds on CRP compared to native shortgrass prairie are clearly warranted.

  9. Feeding and the Rhodopsin Family G-Protein Coupled Receptors in Nematodes and Arthropods

    PubMed Central

    Cardoso, João C.R.; Félix, Rute C.; Fonseca, Vera G.; Power, Deborah M.

    2012-01-01

    In vertebrates, receptors of the rhodopsin G-protein coupled superfamily (GPCRs) play an important role in the regulation of feeding and energy homeostasis and are activated by peptide hormones produced in the brain-gut axis. These peptides regulate appetite and energy expenditure by promoting or inhibiting food intake. Sequence and function homologs of human GPCRs involved in feeding exist in the nematode roundworm, Caenorhabditis elegans (C. elegans), and the arthropod fruit fly, Drosophila melanogaster (D. melanogaster), suggesting that the mechanisms that regulate food intake emerged early and have been conserved during metazoan radiation. Nematodes and arthropods are the most diverse and successful animal phyla on Earth. They can survive in a vast diversity of environments and have acquired distinct life styles and feeding strategies. The aim of the present review is to investigate if this diversity has affected the evolution of invertebrate GPCRs. Homologs of the C. elegans and D. melanogaster rhodopsin receptors were characterized in the genome of other nematodes and arthropods and receptor evolution compared. With the exception of bombesin receptors (BBR) that are absent from nematodes, a similar gene complement was found. In arthropods, rhodopsin GPCR evolution is characterized by species-specific gene duplications and deletions and in nematodes by gene expansions in species with a free-living stage and gene deletions in representatives of obligate parasitic taxa. Based upon variation in GPCR gene number and potentially divergent functions within phyla we hypothesize that life style and feeding diversity practiced by nematodes and arthropods was one factor that contributed to rhodopsin GPCR gene evolution. Understanding how the regulation of food intake has evolved in invertebrates will contribute to the development of novel drugs to control nematodes and arthropods and the pests and diseases that use them as vectors. PMID:23264768

  10. Habitat Heterogeneity Affects Plant and Arthropod Species Diversity and Turnover in Traditional Cornfields

    PubMed Central

    Martínez, Eliana; Rös, Matthias; Bonilla, María Argenis; Dirzo, Rodolfo

    2015-01-01

    The expansion of the agricultural frontier by the clearing of remnant forests has led to human-dominated landscape mosaics. Previous studies have evaluated the effect of these landscape mosaics on arthropod diversity at local spatial scales in temperate and tropical regions, but little is known about fragmentation effects in crop systems, such as the complex tropical traditional crop systems that maintain a high diversity of weeds and arthropods in low-Andean regions. To understand the factors that influence patterns of diversity in human-dominated landscapes, we investigate the effect of land use types on plant and arthropod diversity in traditionally managed cornfields, via surveys of plants and arthropods in twelve traditional cornfields in the Colombian Andes. We estimated alpha and beta diversity to analyze changes in diversity related to land uses within a radius of 100 m to 1 km around each cornfield. We observed that forests influenced alpha diversity of plants, but not of arthropods. Agricultural lands had a positive relationship with plants and herbivores, but a negative relationship with predators. Pastures positively influenced the diversity of plants and arthropods. In addition, forest cover seemed to influence changes in plant species composition and species turnover of herbivore communities among cornfields. The dominant plant species varied among fields, resulting in high differentiation of plant communities. Predator communities also exhibited high turnover among cornfields, but differences in composition arose mainly among rare species. The crop system evaluated in this study represents a widespread situation in the tropics, therefore, our results can be of broad significance. Our findings suggest that traditional agriculture may not homogenize biological communities, but instead could maintain the regional pool of species through high beta diversity. PMID:26197473

  11. Rapid mortality of pest arthropods by direct exposure to a dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Bures, Brian Lee

    The spread of arthropods due to trade of agricultural commodities and travel of humans is a significant problem in many countries. Limiting the movement of pest species is commonly achieved by the use of chemical pesticides at quarantine facilities. One potential alternative to chemical pesticides is direct exposure of contaminated commodities to ambient pressure electrical discharges. The arthropods are directly exposed to a 5.0 cm helium discharge with power densities on the order of 60 mW/cm3. Direct measurement of chemical species and ambient gas temperature shows the DBD treatment remains effective when the chemically reactive species are suppressed by helium, and when the ambient gas temperature of the discharge is below 40°C. In addition to gas temperature measurements and chemical species identification, the electron temperature and electron density were measured using the neutral bremsstrahlung continuum technique. This study is the first successful implementation of the neutral bremsstrahlung continuum emission diagnostic to a barrier discharge. The primary advantages of the diagnostic for barrier discharges are the measurement is passive and the spatial resolution is only limited by the collimation of the light and the sensitivity of the detector. Although the electron temperature (1.0--1.5 eV) and electron density (˜108 cm-3) are modest, non-chemical dielectric barrier discharge (DBD) treatment of arthropods has proven effective in significantly reducing the population of some arthropods including human body lice, green peach aphids, and western flower thrips. However, the treatment was not universally effective on all arthropod species. German cockroaches and citrus mealy bugs showed substantial resistance to the treatment. The study has shown the treatment does not always induce instant mortality: however, the mortality increases over a 24 hr-period after treatment. Based upon visual observation and the time after treatment to reach maximum

  12. Deriving criteria to select arthropod species for laboratory tests to assess the ecological risks from cultivating transgenic crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arthropods form a major part of the biodiversity in agricultural landscapes. Many species are valued because they provide ecosystem services, including biological control, pollination, and decomposition, or because they are valued for cultural or economic reasons. Some arthropods reduce crop yield a...

  13. Recommendations for the design of laboratory studies on non-target arthropods for risk assessment of genetically engineered plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper provides recommendations on experimental design for early-tier laboratory studies used in the risk assessment process to evaluate potential adverse impacts of arthropod-resistant genetically-engineered plants on non-target arthropods. While we rely heavily on the currently used proteins f...

  14. Relationship between land use pattern and the structure and diversity of soil meso-micro arthropod community.

    PubMed

    Zhang, Limin; Zhang, Xueping; Cui, Wei

    2014-05-01

    Soil arthropod communities can provide valuable information regarding the impacts of human disturbances on ecosystem structure. Our study evaluated the structure, composition and diversity of soil meso-micro arthropod communities, in six different vegetation types and assessed the impacts of human activity. A completely randomized design, including 3 replicates from 6 sites (mowing steppe, natural grassland, severe degradation grassland, farmland, artificial shelter forest, and wetland) was used. Soil samples from the depth of 0 to 20 cm were collected during May, July, and September 2007. Soil meso-micro arthropod were separated using the Tullgren funnels method, and were identified and counted. Soil pH value, organic matter, and total nitrogen were measured in topsoil (0-20 cm) from each site. A total of 5,602 soil meso-micro arthropod individuals were collected, representing 4 classes, 14 orders, and 57 families. Most soil arthropods were widely distributed; however, some species appeared to be influenced by environment variables, and might serve as bioindicators of adverse human impacts. Canonical correspondence analysis indicated the soil arthropod distribution in the severely degraded grassland, mowing steppe, farmland, and shelter forest differed from the natural grassland. Arthropod density and diversity were greatest in May, and the forestland community was the most stable. Because of the vital role soil arthropods have in maintaining a healthy ecosystem, mechanisms to maintain their abundance and diversity should be further evaluated. PMID:24468921

  15. The diversity and abundance of small arthropods in onion, Allium cepa, seed crops, and their potential role in pollination.

    PubMed

    Walker, M K; Howlett, B G; Wallace, A R; McCallum, J A; Teulon, D A J

    2011-01-01

    Onion, Allium cepa L. (Asparagales: Amaryllidaceae), crop fields grown for seed production require arthropod pollination for adequate seed yield. Although many arthropod species visit A. cepa flowers, for most there is little information on their role as pollinators. Small flower visiting arthropods (body width < 3 mm) in particular are rarely assessed. A survey of eight flowering commercial A. cepa seed fields in the North and South Islands of New Zealand using window traps revealed that small arthropods were highly abundant among all except one field. Insects belonging to the orders Diptera and Thysanoptera were the most abundant and Hymenoptera, Collembola, Psocoptera, Hemiptera, and Coleoptera were also present. To test whether small arthropods might contribute to pollination, seed sets from umbels caged within 3 mm diameter mesh cages were compared with similarly caged, hand-pollinated umbels and uncaged umbels. Caged umbels that were not hand-pollinated set significantly fewer seeds (average eight seeds/umbel, n = 10) than caged hand-pollinated umbels (average 146 seeds/umbel) and uncaged umbels (average 481 seeds/umbel). Moreover, sticky traps placed on umbels within cages captured similar numbers of small arthropods as sticky traps placed on uncaged umbels, suggesting cages did not inhibit the movement of small arthropods to umbels. Therefore, despite the high abundance of small arthropods within fields, evidence to support their role as significant pollinators of commercial A. cepa seed crops was not found. PMID:22208869

  16. The Diversity and Abundance of Small Arthropods in Onion, Allium cepa, Seed Crops, and their Potential Role in Pollination

    PubMed Central

    Walker, M. K.; Howlett, B. G.; Wallace, A. R.; Mccallum, J. A.; Teulon, D. A. J.

    2011-01-01

    Onion, Allium cepa L. (Asparagales: Amaryllidaceae), crop fields grown for seed production require arthropod pollination for adequate seed yield. Although many arthropod species visit A. cepa flowers, for most there is little information on their role as pollinators. Small flower visiting arthropods (body width < 3 mm) in particular are rarely assessed. A survey of eight flowering commercial A. cepa seed fields in the North and South Islands of New Zealand using window traps revealed that small arthropods were highly abundant among all except one field. Insects belonging to the orders Diptera and Thysanoptera were the most abundant and Hymenoptera, Collembola, Psocoptera, Hemiptera, and Coleoptera were also present. To test whether small arthropods might contribute to pollination, seed sets from umbels caged within 3 mm diameter mesh cages were compared with similarly caged, hand-pollinated umbels and uncaged umbels. Caged umbels that were not hand-pollinated set significantly fewer seeds (average eight seeds/umbel, n = 10) than caged hand-pollinated umbels (average 146 seeds/umbel) and uncaged umbels (average 481 seeds/umbel). Moreover, sticky traps placed on umbels within cages captured similar numbers of small arthropods as sticky traps placed on uncaged umbels, suggesting cages did not inhibit the movement of small arthropods to umbels. Therefore, despite the high abundance of small arthropods within fields, evidence to support their role as significant pollinators of commercial A. cepa seed crops was not found. PMID:22208869

  17. Interference of boll weevil trapping by spiders (Araneida) and an evaluation of trap modification to reduce unwanted arthropods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our evaluation of a boll weevil trap modified to reduce the number of unwanted arthropods had little effect on reducing spiders, the arthropod species that made up > 95% of the individuals that entered boll weevil (Anthonomus grandis grandis Boheman) traps and interfere with weekly capture of boll w...

  18. The Multiple Impacts of Tropical Forest Fragmentation on Arthropod Biodiversity and on their Patterns of Interactions with Host Plants

    PubMed Central

    Benítez-Malvido, Julieta; Dáttilo, Wesley; Martínez-Falcón, Ana Paola; Durán-Barrón, César; Valenzuela, Jorge; López, Sara; Lombera, Rafael

    2016-01-01

    Tropical rain forest fragmentation affects biotic interactions in distinct ways. Little is known, however, about how fragmentation affects animal trophic guilds and their patterns of interactions with host plants. In this study, we analyzed changes in biotic interactions in forest fragments by using a multitrophic approach. For this, we classified arthropods associated with Heliconia aurantiaca herbs into broad trophic guilds (omnivores, herbivores and predators) and assessed the topological structure of intrapopulation plant-arthropod networks in fragments and continuous forests. Habitat type influenced arthropod species abundance, diversity and composition with greater abundance in fragments but greater diversity in continuous forest. According to trophic guilds, coleopteran herbivores were more abundant in continuous forest and overall omnivores in fragments. Continuous forest showed a greater diversity of interactions than fragments. Only in fragments, however, did the arthropod community associated with H aurantiaca show a nested structure, suggesting novel and/or opportunistic host-arthropod associations. Plants, omnivores and predators contributed more to nestedness than herbivores. Therefore, Heliconia-arthropod network properties do not appear to be maintained in fragments mainly caused by the decrease of herbivores. Our study contributes to the understanding of the impact of fragmentation on the structure and dynamics of multitrophic arthropod communities associated with a particular plant species of the highly biodiverse tropical forests. Nevertheless, further replication of study sites is needed to strengthen the conclusion that forest fragmentation negatively affects arthropod assemblages. PMID:26731271

  19. The Multiple Impacts of Tropical Forest Fragmentation on Arthropod Biodiversity and on their Patterns of Interactions with Host Plants.

    PubMed

    Benítez-Malvido, Julieta; Dáttilo, Wesley; Martínez-Falcón, Ana Paola; Durán-Barrón, César; Valenzuela, Jorge; López, Sara; Lombera, Rafael

    2016-01-01

    Tropical rain forest fragmentation affects biotic interactions in distinct ways. Little is known, however, about how fragmentation affects animal trophic guilds and their patterns of interactions with host plants. In this study, we analyzed changes in biotic interactions in forest fragments by using a multitrophic approach. For this, we classified arthropods associated with Heliconia aurantiaca herbs into broad trophic guilds (omnivores, herbivores and predators) and assessed the topological structure of intrapopulation plant-arthropod networks in fragments and continuous forests. Habitat type influenced arthropod species abundance, diversity and composition with greater abundance in fragments but greater diversity in continuous forest. According to trophic guilds, coleopteran herbivores were more abundant in continuous forest and overall omnivores in fragments. Continuous forest showed a greater diversity of interactions than fragments. Only in fragments, however, did the arthropod community associated with H aurantiaca show a nested structure, suggesting novel and/or opportunistic host-arthropod associations. Plants, omnivores and predators contributed more to nestedness than herbivores. Therefore, Heliconia-arthropod network properties do not appear to be maintained in fragments mainly caused by the decrease of herbivores. Our study contributes to the understanding of the impact of fragmentation on the structure and dynamics of multitrophic arthropod communities associated with a particular plant species of the highly biodiverse tropical forests. Nevertheless, further replication of study sites is needed to strengthen the conclusion that forest fragmentation negatively affects arthropod assemblages. PMID:26731271

  20. [Alpha and beta arthropods diversity from the different environments of Parque Nacional Los Cardones, Salta, Argentina].

    PubMed

    Belén Cava, Maria; Antonio Corronca, José; José Echeverría, Alejandro

    2013-12-01

    The essential role of the National Parks is to protect nature, in order to prevent the deterioration and loss of the ecosystem under protection. Very few records about the diversity of arthropods are known from Los Cardones National Park, where three eco-regions are protected: Puna and Monte eco-regions and the High Andean Grassland of the Yungas. Here, we aimed to compare the alpha and beta diversity of arthropods in these eco-regions, and to prove if sites from the same ecoregion, show greater similarity between them in their assemblages, than with sites of the other eco-regions. We also identified arthropod orders with higher species richness, and indicated the families that contribute the most to the registered beta diversity. Three sampling sites were established on each eco-region and the arthropods were sampled using pitfall traps and suction samples. We evaluated the obtained inventory through nonparametric estimators of species richness, and compared diversity among eco-regions through "diversity profiles" and "effective number of species". Beta diversity was assessed by different methods such as the Morisita Index, nonmetric multidimentional scaling analysis, a multiple permutation procedure, and a Similarity Percentage analysis. We recorded 469 spp/morphospecies and recognized three arthropod orders (spiders, dipterans and hymenopterans) that are diverse and abundant in the Park. Besides, the diversity in Los Cardones National Park was found to be high, but it was observed higher in the High Andean Grassland of the Yungas, and lower in the Puna. The inventory obtained was good, reached up to the 81% of the species richness estimated by nonparametric estimators. Each eco-region of the park showed a very particular arthropod community that was tested by a multi-response permutation procedure. The species turnover between eco-regions was high, so that the different environments of the protected area are contributing to the maintenance of the regional

  1. Experimental Manipulation of Grassland Plant Diversity Induces Complex Shifts in Aboveground Arthropod Diversity

    PubMed Central

    Hertzog, Lionel R.; Meyer, Sebastian T.; Weisser, Wolfgang W.; Ebeling, Anne

    2016-01-01

    Changes in producer diversity cause multiple changes in consumer communities through various mechanisms. However, past analyses investigating the relationship between plant diversity and arthropod consumers focused only on few aspects of arthropod diversity, e.g. species richness and abundance. Yet, shifts in understudied facets of arthropod diversity like relative abundances or species dominance may have strong effects on arthropod-mediated ecosystem functions. Here we analyze the relationship between plant species richness and arthropod diversity using four complementary diversity indices, namely: abundance, species richness, evenness (equitability of the abundance distribution) and dominance (relative abundance of the dominant species). Along an experimental gradient of plant species richness (1, 2, 4, 8, 16 and 60 plant species), we sampled herbivorous and carnivorous arthropods using pitfall traps and suction sampling during a whole vegetation period. We tested whether plant species richness affects consumer diversity directly (i), or indirectly through increased productivity (ii). Further, we tested the impact of plant community composition on arthropod diversity by testing for the effects of plant functional groups (iii). Abundance and species richness of both herbivores and carnivores increased with increasing plant species richness, but the underlying mechanisms differed between the two trophic groups. While higher species richness in herbivores was caused by an increase in resource diversity, carnivore richness was driven by plant productivity. Evenness of herbivore communities did not change along the gradient in plant species richness, whereas evenness of carnivores declined. The abundance of dominant herbivore species showed no response to changes in plant species richness, but the dominant carnivores were more abundant in species-rich plant communities. The functional composition of plant communities had small impacts on herbivore communities, whereas

  2. Experimental Manipulation of Grassland Plant Diversity Induces Complex Shifts in Aboveground Arthropod Diversity.

    PubMed

    Hertzog, Lionel R; Meyer, Sebastian T; Weisser, Wolfgang W; Ebeling, Anne

    2016-01-01

    Changes in producer diversity cause multiple changes in consumer communities through various mechanisms. However, past analyses investigating the relationship between plant diversity and arthropod consumers focused only on few aspects of arthropod diversity, e.g. species richness and abundance. Yet, shifts in understudied facets of arthropod diversity like relative abundances or species dominance may have strong effects on arthropod-mediated ecosystem functions. Here we analyze the relationship between plant species richness and arthropod diversity using four complementary diversity indices, namely: abundance, species richness, evenness (equitability of the abundance distribution) and dominance (relative abundance of the dominant species). Along an experimental gradient of plant species richness (1, 2, 4, 8, 16 and 60 plant species), we sampled herbivorous and carnivorous arthropods using pitfall traps and suction sampling during a whole vegetation period. We tested whether plant species richness affects consumer diversity directly (i), or indirectly through increased productivity (ii). Further, we tested the impact of plant community composition on arthropod diversity by testing for the effects of plant functional groups (iii). Abundance and species richness of both herbivores and carnivores increased with increasing plant species richness, but the underlying mechanisms differed between the two trophic groups. While higher species richness in herbivores was caused by an increase in resource diversity, carnivore richness was driven by plant productivity. Evenness of herbivore communities did not change along the gradient in plant species richness, whereas evenness of carnivores declined. The abundance of dominant herbivore species showed no response to changes in plant species richness, but the dominant carnivores were more abundant in species-rich plant communities. The functional composition of plant communities had small impacts on herbivore communities, whereas

  3. Production of arthropod pests and vectors in coal strip mine ponds. Program report

    SciTech Connect

    Pickard, E.

    1981-06-01

    The objective of this study was to determine what species of medically important arthropods, particularly mosquitoes, are breeding in coal strip mine ponds, to what extent, and whether these breeding sites will serve as a focus of annoyance or a potential outbreak center of arthropod-borne diseases to surrounding communities. Pond age was compared with physical and chemical characteristics of the water and associated vegetation communities. Various sampling techniques were used to determine the composition and density of all life stages of the aquatic insect fauna.

  4. Onychophoran Hox genes and the evolution of arthropod Hox gene expression

    PubMed Central

    2014-01-01

    Introduction Onychophora is a relatively small phylum within Ecdysozoa, and is considered to be the sister group to Arthropoda. Compared to the arthropods, that have radiated into countless divergent forms, the onychophoran body plan is overall comparably simple and does not display much in-phylum variation. An important component of arthropod morphological diversity consists of variation of tagmosis, i.e. the grouping of segments into functional units (tagmata), and this in turn is correlated with differences in expression patterns of the Hox genes. How these genes are expressed in the simpler onychophorans, the subject of this paper, would therefore be of interest in understanding their subsequent evolution in the arthropods, especially if an argument can be made for the onychophoran system broadly reflecting the ancestral state in the arthropods. Results The sequences and embryonic expression patterns of the complete set of ten Hox genes of an onychophoran (Euperipatoides kanangrensis) are described for the first time. We find that they are all expressed in characteristic patterns that suggest a function as classical Hox genes. The onychophoran Hox genes obey spatial colinearity, and with the exception of Ultrabithorax (Ubx), they all have different and distinct anterior expression borders. Notably, Ubx transcripts form a posterior to anterior gradient in the onychophoran trunk. Expression of all onychophoran Hox genes extends continuously from their anterior border to the rear end of the embryo. Conclusions The spatial expression pattern of the onychophoran Hox genes may contribute to a combinatorial Hox code that is involved in giving each segment its identity. This patterning of segments in the uniform trunk, however, apparently predates the evolution of distinct segmental differences in external morphology seen in arthropods. The gradient-like expression of Ubx may give posterior segments their specific identity, even though they otherwise express the same

  5. Collection & Processing of Medically Important Arthropods for Arbovirus Isolation.

    ERIC Educational Resources Information Center

    Sudia, W. Daniel; Chamberlain, Roy W.

    The methods given for collecting, preserving, and processing mosquitoes and other archropods for isolation of arboviruses are those used by the National Communicable Disease Center. Techniques of collecting mosquitoes as they bite, using light or bait traps, and from their daytime resting sites are described and illustrated. Details of subsequent…

  6. Temporal dynamics of arthropods on six tree species in dry woodlands on the Caribbean Island of Puerto Rico.

    PubMed

    Beltrán, William; Wunderle, Joseph M

    2014-01-01

    The seasonal dynamics of foliage arthropod populations are poorly studied in tropical dry forests despite the importance of these studies for understanding arthropod population responses to environmental change. We monitored the abundance, temporal distributions, and body size of arthropods in five naturalized alien and one native tree species to characterize arthropod seasonality in dry novel Prosopis-Leucaena woodlands in Puerto Rico. A branch clipping method was used monthly to sample foliage arthropod abundance over 39 mo. Seasonal patterns of rainfall and abundance within various arthropod taxa were highly variable from year to year. Abundance for most taxa did not show significant seasonality over the 3 yr, although most taxa had abundance peaks each year. However, Homoptera displayed high seasonality with significant temporal aggregations in each year. Formicidae, Orthoptera, and Coleoptera showed high variation in abundance between wet and dry periods, whereas Hemiptera were consistently more abundant in the wet period. Seasonal differences in mean abundance were found only in a few taxa on Tamarindus indica L., Bucida buceras L., Pithecellobium dulce, and (Roxburgh) Benth. Mean arthropod abundance varied among tree species, with highest numbers on Prosopis juliflora, (Swartz) De Candolle, Pi. dulce, Leucaena leucocephala, and (Lamarck) de Wit. Abundance of Araneae, Orthoptera, Coleoptera, Lepidoptera larvae, and all arthropods showed weak relationships with one or more climatic variables (rainfall, maximum temperature, or relative humidity). Body size of arthropods was usually largest during the dry periods. Overall, total foliage arthropod abundance showed no consistent seasonality among years, which may become a more common trend in dry forests and woodlands in the Caribbean if seasonality of rainfall becomes less predictable. PMID:25502036

  7. Temporal Dynamics of Arthropods on Six Tree Species in Dry Woodlands on the Caribbean Island of Puerto Rico

    PubMed Central

    Beltrán, William; Wunderle, Joseph M.

    2014-01-01

    The seasonal dynamics of foliage arthropod populations are poorly studied in tropical dry forests despite the importance of these studies for understanding arthropod population responses to environmental change. We monitored the abundance, temporal distributions, and body size of arthropods in five naturalized alien and one native tree species to characterize arthropod seasonality in dry novel Prosopis–Leucaena woodlands in Puerto Rico. A branch clipping method was used monthly to sample foliage arthropod abundance over 39 mo. Seasonal patterns of rainfall and abundance within various arthropod taxa were highly variable from year to year. Abundance for most taxa did not show significant seasonality over the 3 yr, although most taxa had abundance peaks each year. However, Homoptera displayed high seasonality with significant temporal aggregations in each year. Formicidae, Orthoptera, and Coleoptera showed high variation in abundance between wet and dry periods, whereas Hemiptera were consistently more abundant in the wet period. Seasonal differences in mean abundance were found only in a few taxa on Tamarindus indica L., Bucida buceras L., Pithecellobium dulce, and (Roxburgh) Benth. Mean arthropod abundance varied among tree species, with highest numbers on Prosopis juliflora, (Swartz) De Candolle, Pi. dulce, Leucaena leucocephala, and (Lamarck) de Wit. Abundance of Araneae, Orthoptera, Coleoptera, Lepidoptera larvae, and all arthropods showed weak relationships with one or more climatic variables (rainfall, maximum temperature, or relative humidity). Body size of arthropods was usually largest during the dry periods. Overall, total foliage arthropod abundance showed no consistent seasonality among years, which may become a more common trend in dry forests and woodlands in the Caribbean if seasonality of rainfall becomes less predictable. PMID:25502036

  8. The influence of preset frequency, loading condition, and exercise type on the mechanical behavior of a novel vibratory bar.

    PubMed

    Rodríguez-Jiménez, Sergio; Benitez, Adolfo; García González, Miguel A; Feliu, Gerard M; Maffiuletti, Nicola A

    2014-04-01

    This study aimed to analyze the influence of different vibration frequencies, loading conditions, and exercise types on the mechanical behavior of a novel vibratory bar (VB). Fourteen healthy men were asked to hold the VB during lying row (pulling) and bench press (pushing) static exercise as steadily as possible for 10 seconds with loads of 20, 50, and 80% of the maximum sustained load (MSL) and at preset vibration frequencies (f(in)) of 20, 35, and 50 Hz. Root mean square vibration acceleration (a(RMS)), peak-to-peak displacement (D), and frequency (f(out)) were gained from a 3-dimensional accelerometer fixed to the VB. Increasing vibration frequency (from 20 to 50 Hz) resulted in a progressive and sizeable increase in VB a(RMS) and f(out) (both p ≤ 0.001) with smaller variations of D (≤5.9%, p ≤ 0.001). Adding weight to the VB (progressive overload from 20 to 80% MSL) did not affect D and minimally altered a(RMS) (<4.2%, p = 0.014) and f(out) (<1.7%, p = 0.002). Altering the type of exercise (pulling vs. pushing) did not affect VB a(RMS), D, and f(out). In conclusion, this study establishes the validity of a novel VB and legitimates its use for effective and safe upper-body static exercise with a wide range of vibration frequencies and loading conditions in the context of physical training or rehabilitation. PMID:23838974

  9. Design and Analysis of a Novel Fully Decoupled Tri-axis Linear Vibratory Gyroscope with Matched Modes

    PubMed Central

    Xia, Dunzhu; Kong, Lun; Gao, Haiyu

    2015-01-01

    We present in this paper a novel fully decoupled silicon micromachined tri-axis linear vibratory gyroscope. The proposed gyroscope structure is highly symmetrical and can be limited to an area of about 8.5 mm × 8.5 mm. It can differentially detect three axes’ angular velocities at the same time. By elaborately arranging different beams, anchors and sensing frames, the drive and sense modes are fully decoupled from each other. Moreover, the quadrature error correction and frequency tuning functions are taken into consideration in the structure design for all the sense modes. Since there exists an unwanted in-plane rotational mode, theoretical analysis is implemented to eliminate it. To accelerate the mode matching process, the particle swam optimization (PSO) algorithm is adopted and a frequency split of 149 Hz is first achieved by this method. Then, after two steps of manual adjustment of the springs’ dimensions, the frequency gap is further decreased to 3 Hz. With the help of the finite element method (FEM) software ANSYS, the natural frequencies of drive, yaw, and pitch/roll modes are found to be 14,017 Hz, 14,018 Hz and 14,020 Hz, respectively. The cross-axis effect and scale factor of each mode are also simulated. All the simulation results are in good accordance with the theoretical analysis, which means the design is effective and worthy of further investigation on the integration of tri-axis accelerometers on the same single chip to form an inertial measurement unit. PMID:26184217

  10. Design and Analysis of a Novel Fully Decoupled Tri-axis Linear Vibratory Gyroscope with Matched Modes.

    PubMed

    Xia, Dunzhu; Kong, Lun; Gao, Haiyu

    2015-01-01

    We present in this paper a novel fully decoupled silicon micromachined tri-axis linear vibratory gyroscope. The proposed gyroscope structure is highly symmetrical and can be limited to an area of about 8.5 mm × 8.5 mm. It can differentially detect three axes' angular velocities at the same time. By elaborately arranging different beams, anchors and sensing frames, the drive and sense modes are fully decoupled from each other. Moreover, the quadrature error correction and frequency tuning functions are taken into consideration in the structure design for all the sense modes. Since there exists an unwanted in-plane rotational mode, theoretical analysis is implemented to eliminate it. To accelerate the mode matching process, the particle swam optimization (PSO) algorithm is adopted and a frequency split of 149 Hz is first achieved by this method. Then, after two steps of manual adjustment of the springs' dimensions, the frequency gap is further decreased to 3 Hz. With the help of the finite element method (FEM) software ANSYS, the natural frequencies of drive, yaw, and pitch/roll modes are found to be 14,017 Hz, 14,018 Hz and 14,020 Hz, respectively. The cross-axis effect and scale factor of each mode are also simulated. All the simulation results are in good accordance with the theoretical analysis, which means the design is effective and worthy of further investigation on the integration of tri-axis accelerometers on the same single chip to form an inertial measurement unit. PMID:26184217

  11. NERISK: AN EXPERT SYSTEM TO ENHANCE THE INTEGRATION OF PESTICIDES WITH ARTHROPOD BIOLOGICAL CONTROL

    EPA Science Inventory

    An expert system termed NERISK was developed to evaluate the effects of pesticides on arthropod predators and parasitoids in a variety of agroecosystems. ased on a shell system (RECOG) with minor coding modifications, the system was designed to let even a novice user access the v...

  12. The midgut epithelium of aquatic arthropods: a critical target organ in environmental toxicology.

    PubMed Central

    Beaty, Barry J; Mackie, Ryan S; Mattingly, Kimberly S; Carlson, Jonathan O; Rayms-Keller, Alfredo

    2002-01-01

    The midgut epithelium of aquatic arthropods is emerging as an important and toxicologically relevant organ system for monitoring environmental pollution. The peritrophic matrix of aquatic arthropods, which is secreted by the midgut epithelium cells, is perturbed by copper or cadmium. Molecular biological studies have identified and characterized two midgut genes induced by heavy metals in the midgut epithelium. Many other metal-responsive genes (MRGs) await characterization. One of the MRGs codes for an intestinal mucin, which is critical for protecting the midgut from toxins and pathogens. Another codes for a tubulin gene, which is critical for structure and function of the midgut epithelial cells. Perturbation of expression of either gene could condition aquatic arthropod survivorship. Induction of these MRGs is a more sensitive and rapid indicator of heavy-metal pollution than biological assays. Characterization of genes induced by pollutants could provide mechanistic understanding of fundamental cellular responses to pollutants and insight into determinants of aquatic arthropod population genetic structure and survivorship in nature. PMID:12634118

  13. Water deficit stress - host plant nutrient accumulations and associations with phytophagous arthropods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In addition to making otherwise arable regions less, or nonarable, from lack of life-sustaining water, water deficit also affects the extent to which crops are afflicted by arthropod pests. This chapter focuses on the effects of water deficit stress on physical and nutritional aspects of host plants...

  14. Arthropods, plants and transmission lines in Arizona: community dynamics during secondary succession in a desert grassland

    SciTech Connect

    Butt, S.M.; Beley, J.R.; Ditsworth, T.M.; Johnson, C.D.; Balda, R.P.

    1980-11-01

    In 1972, access roads were constructed and then used by heavy equipment to build a 500 kV powerline in north central Arizona. Secondary succession of arthropods was studied till 1977 by comparing the initially bare soil of the roads with undisturbed control plots nearby. It was found that, after construction, total anthropod densities were reduced for two to three years, that after five years no anthropod taxa had greater densities on the disturbed areas, but some were significantly reduced, the diversity of arthropods dropped for a period of three or four years, that arthropod community similarity of the two study plots appeared to be related to total cover of plants and similarity of plant communities, the significant correlations between arthropod taxa suggested that the plant communities of the two plots are close in successional status, plant succession was not as rapid as expected, and the disturbed area had a great reduction in perennial grasses but an increase in annual herbs. The numerical dominance of herbivores on both disturbed and control plots, especially after construction, supports the hypothesis that linear, predominantly grazing food chains are characteristic of early successional stages.

  15. A Nod to disease vectors: mitigation of pathogen sensing by arthropod saliva

    PubMed Central

    Sakhon, Olivia S.; Severo, Maiara S.; Kotsyfakis, Michail; Pedra, Joao H. F.

    2013-01-01

    Arthropod saliva possesses anti-hemostatic, anesthetic, and anti-inflammatory properties that facilitate feeding and, inadvertently, dissemination of pathogens. Vector-borne diseases caused by these pathogens affect millions of people each year. Many studies address the impact of arthropod salivary proteins on various immunological components. However, whether and how arthropod saliva counters Nod-like (NLR) sensing remains elusive. NLRs are innate immune pattern recognition molecules involved in detecting microbial molecules and danger signals. Nod1/2 signaling results in activation of the nuclear factor-κB and the mitogen-activated protein kinase pathways. Caspase-1 NLRs regulate the inflammasome~– a protein scaffold that governs the maturation of interleukin (IL)-1β and IL-18. Recently, several vector-borne pathogens have been shown to induce NLR activation in immune cells. Here, we provide a brief overview of NLR signaling and discuss clinically relevant vector-borne pathogens recognized by NLR pathways. We also elaborate on possible anti-inflammatory effects of arthropod saliva on NLR signaling and microbial pathogenesis for the purpose of exchanging research perspectives. PMID:24155744

  16. Disparate effects of plant genotypic diversity on foliage and litter arthropod communities

    SciTech Connect

    Crutsinger, Greg; Reynolds, Nicholas; Classen, Aimee T; Sanders, Dr. Nathan James

    2008-01-01

    Intraspecific diversity within plant species is increasingly recognized as an important influence on the structure of associated arthropod communities, though whether there are congruent responses of above- and belowground communities to intraspecific diversity remains unclear. In this study, we compare the effects of host-plant genotype and genotypic diversity of the perennial plant, Solidago altissima, on the arthropod community associated with living plant tissue (foliage-based community) and microarthropods associated with leaf litter (litter-based community). We found that variation among host-plant genotypes had strong effects on the diversity and composition of foliage-based arthropods, but only weak influence on litter-based microarthropods. Furthermore, host-plant genotypic diversity was positively related to the abundance and diversity of foliage-based arthropods, including herbivore and predator trophic levels. In contrast, there were minimal effects of genotypic diversity in litter on microarthropods. Our study illustrates that incorporating both above- and belowground perspective into community genetics studies leads to very different conclusions about the importance of intraspecific diversity, than when considering aboveground responses in isolation.

  17. PRODUCTION OF ARTHROPOD PESTS AND VECTORS IN COAL STRIP MINE PONDS

    EPA Science Inventory

    The objective of this study was to determine what species of medically important arthropods, particularly mosquitoes, are breeding in coal strip mine ponds, to what extent, and whether these breeding sites will serve as a focus of annoyance or a potential outbreak center of arthr...

  18. Mini-aspirator: A new device for collection and transfer of small arthropods to plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The process of collecting and/or infesting plants with a designated number of small arthropods in biological experiments is tedious and laborious. We developed a modified mini-aspirator, powered with a vacuum pump and fitted with a specially adapted (removeable) collecting vial to reduce the handli...

  19. Reduced use of pesticides for effective controls of arthropod pests and plant diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current label recommendations of pesticides for arthropod pests and plant diseases in the nursery and green industry are vague and frequently result in excessive pesticide use. The objective of this research was to demonstrate that modifications of spray application techniques with existing spray eq...

  20. Density-Dependent Effects of an Invasive Ant on a Ground-Dwelling Arthropod Community.

    PubMed

    Cooling, M; Sim, D A; Lester, P J

    2015-02-01

    It is frequently assumed that an invasive species that is ecologically or economically damaging in one region, will typically be so in other environments. The Argentine ant Linepithema humile (Mayr) is listed among the world's worst invaders. It commonly displaces resident ant species where it occurs at high population densities, and may also reduce densities of other ground-dwelling arthropods. We investigated the effect of varying Argentine ant abundance on resident ant and nonant arthropod species richness and abundance in seven cities across its range in New Zealand. Pitfall traps were used to compare an invaded and uninvaded site in each city. Invaded sites were selected based on natural varying abundance of Argentine ant populations. Argentine ant density had a significant negative effect on epigaeic ant abundance and species richness, but hypogaeic ant abundance and species richness was unaffected. We observed a significant decrease in Diplopoda abundance with increasing Argentine ant abundance, while Coleoptera abundance increased. The effect on Amphipoda and Isopoda depended strongly on climate. The severity of the impact on negatively affected taxa was reduced in areas where Argentine ant densities were low. Surprisingly, Argentine ants had no effect on the abundance of the other arthropod taxa examined. Morphospecies richness for all nonant arthropod taxa was unaffected by Argentine ant abundance. Species that are established as invasive in one location therefore cannot be assumed to be invasive in other locations based on presence alone. Appropriate management decisions should reflect this knowledge. PMID:26308805

  1. An overview of arthropod-associated fungi from Argentina and Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arthropod pests in forest and agricultural systems are afflicted by a plethora of pathogenic organisms. Among them, entomopathogenic fungi are the most common control agents that regulate their populations. This review compiles the information available from Argentina and Brazil about the entomopath...

  2. Francisella–Arthropod Vector Interaction and its Role in Patho-Adaptation to Infect Mammals

    PubMed Central

    Akimana, Christine; Kwaik, Yousef Abu

    2011-01-01

    Francisella tularensis is a Gram-negative, intracellular, zoonotic bacterium, and is the causative agent of tularemia with a broad host range. Arthropods such as ticks, mosquitoes, and flies maintain F. tularensis in nature by transmitting the bacteria among small mammals. While the tick is largely believed to be a biological vector of F. tularensis, transmission by mosquitoes and flies is largely believed to be mechanical on the mouthpart through interrupted feedings. However, the mechanism of infection of the vectors by F. tularensis is not well understood. Since F. tularensis has not been localized in the salivary gland of the primary human biting ticks, it is thought that bacterial transmission by ticks is through mechanical inoculation of tick feces containing F. tularensis into the skin wound. Drosophila melanogaster is an established good arthropod model for arthropod vectors of tularemia, where F. tularensis infects hemocytes, and is found in hemolymph, as seen in ticks. In addition, phagosome biogenesis and robust intracellular proliferation of F. tularensis in arthropod-derived cells are similar to that in mammalian macrophages. Furthermore, bacterial factors required for infectivity of mammals are often required for infectivity of the fly by F. tularensis. Several host factors that contribute to F. tularensis intracellular pathogenesis in D. melanogaster have been identified, and F. tularensis targets some of the evolutionarily conserved eukaryotic processes to enable intracellular survival and proliferation in evolutionarily distant hosts. PMID:21687425

  3. Vertical T-maze choice assay for arthropod response to odorants.

    PubMed

    Stelinski, Lukasz; Tiwari, Siddharth

    2013-01-01

    Given the economic importance of insects and arachnids as pests of agricultural crops, urban environments or as vectors of plant and human diseases, various technologies are being developed as control tools. A subset of these tools focuses on modifying the behavior of arthropods by attraction or repulsion. Therefore, arthropods are often the focus of behavioral investigations. Various tools have been developed to measure arthropod behavior, including wind tunnels, flight mills, servospheres, and various types of olfactometers. The purpose of these tools is to measure insect or arachnid response to visual or more often olfactory cues. The vertical T-maze olfactometer described here measures choices performed by insects in response to attractants or repellents. It is a high throughput assay device that takes advantage of the positive phototaxis (attraction to light) and negative geotaxis (tendency to walk or fly upward) exhibited by many arthropods. The olfactometer consists of a 30 cm glass tube that is divided in half with a Teflon strip forming a T-maze. Each half serves as an arm of the olfactometer enabling the test subjects to make a choice between two potential odor fields in assays involving attractants. In assays involving repellents, lack of normal response to known attractants can also be measured as a third variable. PMID:23439130

  4. Field Documentation of Unusual Post-Mortem Arthropod Activity on Human Remains.

    PubMed

    Pechal, Jennifer L; Benbow, M Eric; Tomberlin, Jeffery K; Crippen, Tawni L; Tarone, Aaron M; Singh, Baneshwar; Lenhart, Paul A

    2015-01-01

    During a forensic investigation, the presence of physical marks on human remains can influence the interpretation of events related to the death of an individual. Some tissue injury on human remains can be misinterpreted as ante- or peri-mortem wounds by an investigator when in reality the markings resulted from post-mortem arthropod activity. Unusual entomological data were collected during a study examining the decomposition of a set of human remains in San Marcos, Texas. An adult female Pediodectes haldemani (Girard) (Orthoptera: Tettigoniidae) and an Armadillidium cf. vulgare (Isopoda: Armadilidiidae) were documented feeding on the remains. Both arthropods produced physical marks or artifacts on the remains that could be misinterpreted as attack, abuse, neglect, or torture. Additionally, red imported fire ants, Solenopsis invicta Buren (Hymenoptera: Formicidae), were observed constructing structures in the mark produced by the P. haldemani feeding. These observations provide insight into the potential of post-mortem arthropod damage to human remains, which previously had not been described for these taxa, and therefore, physical artifacts on any remains found in similar circumstances may result from arthropod activity and not ante- or peri-mortem wounds. PMID:26336287

  5. Natural products from forest resources for use as arthropod and fungal biocides.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural products from Pacific Northwest forest resources can offer alternatives to the use of synthetic pesticides in the control of both arthropods of public health concern and forest fungal pathogens. Tree heartwood extracts with high toxicity (low LC50) in preliminary brine shrimp bioassays were...

  6. Natural Products from Forest Resources for Use as Arthropod and Fungal Biocides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural products from Pacific Northwest forest resources can offer alternatives to the use of synthetic pesticides in the control of both arthropods of public health concern and forest fungal pathogens. Tree heartwood extracts with high toxicity (low LC50) in preliminary brine shrimp bioassays were...

  7. Teaching Students about Biodiversity by Studying the Correlation between Plants & Arthropods

    ERIC Educational Resources Information Center

    Richardson, Matthew L.; Hari, Janice

    2008-01-01

    On Earth there is a huge diversity of arthropods, many of which are highly adaptive and able to exploit virtually every terrestrial habitat. Because of their prevalence even in urban environments, they make an excellent model system for any life science class. Since plants also exploit virtually every terrestrial habitat, studying the relationship…

  8. THE ROLE OF DEAD WOOD IN MAINTAINING ARTHROPOD DIVERSITY ON THE FOREST FLOOR.

    SciTech Connect

    Hanula, James L.; Horn, Scott; Wade, Dale D.

    2006-08-01

    Abstract—Dead wood is a major component of forests and contributes to overall diversity, primarily by supporting insects that feed directly on or in it. Further, a variety of organisms benefit by feeding on those insects. What is not well known is how or whether dead wood influences the composition of the arthropod community that is not solely dependent on it as a food resource, or whether woody debris influences prey available to generalist predators. One group likely to be affected by dead wood is ground-dwelling arthropods. We studied the effect of adding large dead wood to unburned and frequently burned pine stands to determine if dead wood was used more when the litter and understory plant community are removed. We also studied the effect of annual removal of dead wood from large (10-ha) plots over a 5-year period on ground-dwelling arthropods. In related studies, we examined the relationships among an endangered woodpecker that forages for prey on live trees, its prey, and dead wood in the forest. The results of these and other studies show that dead wood can influence the abundance and diversity of the ground-dwelling arthropod community and of prey available to generalist predators not foraging directly on dead trees.

  9. Selected examples of dispersal of arthropods associated with agricultural crop and animal production

    NASA Technical Reports Server (NTRS)

    Henneberry, T. J.

    1979-01-01

    The economic importance of arthropods in agricultural production systems and the possibilities of using dispersal behavior to develop and manipulate control are examined. Examples of long and short distance dispersal of economic insect pests and beneficial species from cool season host reservoirs and overwintering sites are presented. Significant dispersal of these species often occurring during crop and animal production is discussed.

  10. Relationships between dead wood and arthropods in the Southeastern United States.

    SciTech Connect

    Ulyshen, Michael, Darragh

    2009-05-01

    The importance of dead wood to maintaining forest diversity is now widely recognized. However, the habitat associations and sensitivities of many species associated with dead wood remain unknown, making it difficult to develop conservation plans for managed forests. The purpose of this research, conducted on the upper coastal plain of South Carolina, was to better understand the relationships between dead wood and arthropods in the southeastern United States. In a comparison of forest types, more beetle species emerged from logs collected in upland pine-dominated stands than in bottomland hardwood forests. This difference was most pronounced for Quercus nigra L., a species of tree uncommon in upland forests. In a comparison of wood postures, more beetle species emerged from logs than from snags, but a number of species appear to be dependent on snags including several canopy specialists. In a study of saproxylic beetle succession, species richness peaked within the first year of death and declined steadily thereafter. However, a number of species appear to be dependent on highly decayed logs, underscoring the importance of protecting wood at all stages of decay. In a study comparing litter-dwelling arthropod abundance at different distances from dead wood, arthropods were more abundant near dead wood than away from it. In another study, grounddwelling arthropods and saproxylic beetles were little affected by large-scale manipulations of dead wood in upland pine-dominated forests, possibly due to the suitability of the forests surrounding the plots.

  11. Assessment of Risk of Insect-resistant Transgenic Crops to Nontarget Arthropods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An international initiative is developing a scientifically rigorous approach to evaluate potential risks to non-target arthropods (NTA’s) posed by insect-resistant, genetically modified (IRGM) crops. It adapts the tiered approach to risk assessment that is accepted internationally within regulatory ...

  12. Biostable agonists that match or exceed activity of native insect kinins on recombinant arthropod GPCRs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The multifunctional arthropod insect kinins share the evolutionarily conserved C-terminal pentapeptide motif Phe-X1-X2-Trp-Gly-NH2, where X1 = His, Asn, Ser, or Tyr and X2 = Ser, Pro, or Ala. Insect kinins regulate diuresis in many species of insects. Compounds with similar biological activity cou...

  13. Arthropod phylogeny: an overview from the perspectives of morphology, molecular data and the fossil record.

    PubMed

    Edgecombe, Gregory D

    2010-01-01

    Monophyly of Arthropoda is emphatically supported from both morphological and molecular perspectives. Recent work finds Onychophora rather than Tardigrada to be the closest relatives of arthropods. The status of tardigrades as panarthropods (rather than cycloneuralians) is contentious from the perspective of phylogenomic data. A grade of Cambrian taxa in the arthropod stem group includes gilled lobopodians, dinocaridids (e.g., anomalocaridids), fuxianhuiids and canadaspidids that inform on character acquisition between Onychophora and the arthropod crown group. A sister group relationship between Crustacea (itself likely paraphyletic) and Hexapoda is retrieved by diverse kinds of molecular data and is well supported by neuroanatomy. This clade, Tetraconata, can be dated to the early Cambrian by crown group-type mandibles. The rival Atelocerata hypothesis (Myriapoda+Hexapoda) has no molecular support. The basal node in the arthropod crown group is embroiled in a controversy over whether myriapods unite with chelicerates (Paradoxopoda or Myriochelata) or with crustaceans and hexapods (Mandibulata). Both groups find some molecular and morphological support, though Mandibulata is presently the stronger morphological hypothesis. Either hypothesis forces an unsampled ghost lineage for Myriapoda from the Cambrian to the mid Silurian. PMID:19854297

  14. Characterization of the Arthropod Community Associated with Switchgrass (Poales: Poaceae) in Nebraska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Switchgrass (Panicum virgatum L.) is a perennial warm-season grass, native to the North American Great Plains. Recently, this prairie grass has received increased attention as a potential biomass energy crop. Little is known about the arthropod community affecting switchgrass grown under either mana...

  15. Plant Diversity Impacts Decomposition and Herbivory via Changes in Aboveground Arthropods

    PubMed Central

    Ebeling, Anne; Meyer, Sebastian T.; Abbas, Maike; Eisenhauer, Nico; Hillebrand, Helmut; Lange, Markus; Scherber, Christoph; Vogel, Anja; Weigelt, Alexandra; Weisser, Wolfgang W.

    2014-01-01

    Loss of plant diversity influences essential ecosystem processes as aboveground productivity, and can have cascading effects on the arthropod communities in adjacent trophic levels. However, few studies have examined how those changes in arthropod communities can have additional impacts on ecosystem processes caused by them (e.g. pollination, bioturbation, predation, decomposition, herbivory). Therefore, including arthropod effects in predictions of the impact of plant diversity loss on such ecosystem processes is an important but little studied piece of information. In a grassland biodiversity experiment, we addressed this gap by assessing aboveground decomposer and herbivore communities and linking their abundance and diversity to rates of decomposition and herbivory. Path analyses showed that increasing plant diversity led to higher abundance and diversity of decomposing arthropods through higher plant biomass. Higher species richness of decomposers, in turn, enhanced decomposition. Similarly, species-rich plant communities hosted a higher abundance and diversity of herbivores through elevated plant biomass and C:N ratio, leading to higher herbivory rates. Integrating trophic interactions into the study of biodiversity effects is required to understand the multiple pathways by which biodiversity affects ecosystem functioning. PMID:25226237

  16. First record of an arthropod from the Passaic Formation (Late Triassic), near Milford, New Jersey

    NASA Astrophysics Data System (ADS)

    Metz, Robert

    2012-03-01

    Mudstones of the Triassic Passaic Formation, near Milford, New Jersey, have yielded the first evidence of an arthropod impression in that formation. Associated trace fossils include Helminthoidichnites, Lockeia, Scoyenia, Spongeliomorpha, and the reptile footprint Rhynchosauroides, representing the Scoyenia ichnofacies. Associated sedimentary structures include desiccation cracks and raindrop impressions. The Passaic sediments were deposited under shallow water lacustrine shoreline conditions subject to periodic subaerial exposure.

  17. Removing external DNA decontamination from arthropod predators destined for molecular gut-content analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular gut-content analysis enables detection of arthropod predation with minimal disruption of ecosystem processes. Field and laboratory experiments have demonstrated that mass-collection methods, such as sweep-netting, vacuum sampling, and foliage beating, can lead to contamination of fed pred...

  18. Resistance mechanisms against arthropod herbivores in cotton and their interactions with natural enemies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton plants from the genus Gossypium are grown on more than 30 million hectares worldwide and are a major source of fiber. The plants possess a wide-range of indirect and direct-defense mechanisms against arthropod pests. Direct defense mechanisms include morphological traits such as trichomes and...

  19. ASSESSING PESTICIDE RISK TO ARTHROPOD NATURAL ENEMIES USING EXPERT SYSTEM TECHNOLOGY

    EPA Science Inventory

    A prototype expert system (NERISK) has been developed to help users assess the impact of pesticides on beneficial arthropod predators and parasitoids in agricultural systems. hell program (RECOG) was adapted with minor modifications to allow the encoding of expert opinion on this...

  20. Arthropods, plants, and transmission lines in Arizona: secondary succession in a Sonoran Desert habitat

    SciTech Connect

    Johnson, C.D.; Ditsworth, T.M.; Beley, J.R.

    1981-09-01

    Overall arthropod densities were low at this site, but the arthropod densities on the disturbed areas appeared to be enhanced after several years. No taxa were found to be statistically different in density between control and disturbed plots. Diversity decreased on the disturbed area after construction. Arthropod community similarity (C) was lower after construction, but C values appear to be related to presence or absence of annual herbs and grasses and not to total cover. Except for globe mallow, there were no pioneer plant species on the experimental plot. Effects of powerline construction on the experimental plant community were a brief reduction in total cover and a slight increase in cover of herbs and annual grasses. The 1976 and 1977 samples exhibit comparable cover values of these plants on both experimental and control plots. The dominant arthropod taxa on the experimental area (especially Thysanoptera, Cicadellidae, Coccinellidae, and Melyridae) appear to be responding numerically to the annual herbs and grasses which are becoming established on the plot.

  1. The Hunsrück biota: A unique window into the ecology of Lower Devonian arthropods.

    PubMed

    Rust, Jes; Bergmann, Alexandra; Bartels, Christoph; Schoenemann, Brigitte; Sedlmeier, Stephanie; Kühl, Gabriele

    2016-03-01

    The approximately 400-million-year old Hunsrück biota provides a unique window into Devonian marine life. Fossil evidence suggests that this biota was dominated by echinoderms and various classes of arthropods, including Trilobita, stem lineage representatives of Euarthropoda, Chelicerata and Eucrustacea, as well as several crown group Chelicerata and Eucrustacea. The Hunsrück biota's exceptional preservation allows detailed reconstructions and description of key-aspects of its fauna's functional morphologies thereby revealing modes of locomotion, sensory perception, and feeding strategies. Morphological and stratigraphic data are used for a critical interpretation of the likely habitats, mode of life and nutritional characteristics of this diverse fauna. Potential predators include pycnogonids and other chelicerates, as well as the now extinct stem arthropods Schinderhannes bartelsi, Cambronatus brasseli and Wingertshellicus backesi. Mainly the deposit feeding Trilobita, Marrellomorpha and Megacheira, such as Bundenbachiellus giganteus, represents scavengers. Possibly, opportunistic scavenging was also performed by the afore-mentioned predators. Most of the studied arthropods appear to have been adapted to living in relatively well-illuminated conditions within the photic zone. Fossil evidence for associations amongst arthropods and other classes of metazoans is reported. These associations provide evidence of likely community structures. PMID:26826500

  2. Removing external DNA contamination from arthropod predators destined for molecular gut-content analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular gut-content analysis enables detection of arthropod predation with minimal disruption of ecosystem processes. Field and laboratory experiments have demonstrated that mass-collection methods, such as sweep-netting, vacuum sampling, and foliage beating, can lead to contamination of fed pred...

  3. Natural carbon dioxide generation for the attraction of blood feeding arthropods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hematophagous arthropods are attracted to elevated carbon dioxide levels because it is closely associated with host blood meal availability. Bottled gas or frozen (dry ice) carbon dioxide are commonly used in surveillance programs and field collection techniques to increase the number of species and...

  4. Arthropod food web restoration following removal of an invasive wetland plant.

    PubMed

    Gratton, Claudio; Denno, Robert F

    2006-04-01

    Restoration of habitats impacted by invasive plants is becoming an increasingly important tool in the management of native biodiversity, though most studies do not go beyond monitoring the abundance of particular taxonomic groups, such as the return of native vegetation. Yet, the reestablishment of trophic interactions among organisms in restored habitats is equally important if we are to monitor and understand how ecosystems recover. This study examined whether food web interactions among arthropods (as inferred by abundance of naturally occurring stable isotopes of C [delta13C] and N [delta15N]) were reestablished in the restoration of a coastal Spartina alterniflora salt marsh that had been invaded by Phragmites australis. From patterns of C and N stable isotopes we infer that trophic interactions among arthropods in the native salt marsh habitats are characterized by reliance on the dominant marsh plant Spartina as a basal resource. Herbivores such as delphacid planthoppers and mirid bugs have isotope signatures characteristic of Spartina, and predatory arthropods such as dolicopodid flies and spiders likewise have delta13C and delta15N signatures typical of Spartina-derived resources (approximately -13 per thousand and 10 per thousand, respectively). Stable isotope patterns also suggest that the invasion of Phragmites into salt marshes and displacement of Spartina significantly alter arthropod food web interactions. Arthropods in Phragmites-dominated sites have delta13C isotope values between -18 per thousand and -20 per thousand, suggesting reliance on detritus and/or benthic microalgae as basal resources and not on Phragmites, which has a delta13C approximately -26 per thousand. Since most Phragmites herbivores are either feeding internally or are rare transients from nearby Spartina, these resources do not provide significant prey resources for other arthropod consumers. Rather, predator isotope signatures in the invaded habitats indicate dependence on

  5. The colonization of land by animals: molecular phylogeny and divergence times among arthropods

    PubMed Central

    Pisani, Davide; Poling, Laura L; Lyons-Weiler, Maureen; Hedges, S Blair

    2004-01-01

    Background The earliest fossil evidence of terrestrial animal activity is from the Ordovician, ~450 million years ago (Ma). However, there are earlier animal fossils, and most molecular clocks suggest a deep origin of animal phyla in the Precambrian, leaving open the possibility that animals colonized land much earlier than the Ordovician. To further investigate the time of colonization of land by animals, we sequenced two nuclear genes, glyceraldehyde-3-phosphate dehydrogenase and enolase, in representative arthropods and conducted phylogenetic and molecular clock analyses of those and other available DNA and protein sequence data. To assess the robustness of animal molecular clocks, we estimated the deuterostome-arthropod divergence using the arthropod fossil record for calibration and tunicate instead of vertebrate sequences to represent Deuterostomia. Nine nuclear and 15 mitochondrial genes were used in phylogenetic analyses and 61 genes were used in molecular clock analyses. Results Significant support was found for the unconventional pairing of myriapods (millipedes and centipedes) with chelicerates (spiders, scorpions, horseshoe crabs, etc.) using nuclear and mitochondrial genes. Our estimated time for the divergence of millipedes (Diplopoda) and centipedes (Chilopoda) was 442 ± 50 Ma, and the divergence of insects and crustaceans was estimated as 666 ± 58 Ma. Our results also agree with previous studies suggesting a deep divergence (~1100 – 900 Ma) for arthropods and deuterostomes, considerably predating the Cambrian Explosion seen in the animal fossil record. Conclusions The consistent support for a close relationship between myriapods and chelicerates, using mitochondrial and nuclear genes and different methods of analysis, suggests that this unexpected result is not an artefact of analysis. We propose the name Myriochelata for this group of animals, which includes many that immobilize prey with venom. Our molecular clock analyses using arthropod

  6. Employing citizen science to study defoliation impacts on arthropod communities on tamarisk

    NASA Astrophysics Data System (ADS)

    Kruse, Audrey L.

    The invasive tamarisk tree is widespread across the southwestern landscape of the United States and has been dominant in regulated river reaches, outcompeting native vegetation and impacting trophic webs in riparian ecosystems. The changes in riparian habitat and recreation opportunities along southwestern rivers, like the San Juan River in Utah, led to the implementation of a biocontrol program in the form of the tamarisk leaf beetle (Diorhabda spp.). It is unknown what the long term effects on riparian ecosystems are as a result of the beetles' defoliation of tamarisk each summer. This study sought to identify the current arthropod community composition and abundance over one growing season on the San Juan River between Bluff and Mexican Hat, UT and second, to involve the public in this research through a citizen science component. I found that non-native insects, including the tamarisk leaf beetle, dominated the arboreal arthropod communities within the tamarisk and there are relatively few native arthropods residing in tamarisk throughout the summer season. Foliation levels (the quantity of leaves in the canopy of tamarisk) were inconclusive predictors of arthropod abundances but varied by species and by feeding guild. This may indicate that the defoliation of the tamarisk is not necessarily negatively impacting trophic interactions in tamarisk. I incorporated youth participants on educational river rafting trips to assist in data collection of arthropods from tamarisk trees as a way to educate and bring attention to the issue of invasive species in the Southwest. After completing my own citizen science project and after doing a literature review of other, similar citizen science projects, I found that striving for both rigorous scientific data and quality educational programming is challenging for a small scale project that does not target broad spatial, geographic, or temporal data. Citizen science project developers should clearly identify their objectives

  7. The ABC gene family in arthropods: comparative genomics and role in insecticide transport and resistance.

    PubMed

    Dermauw, Wannes; Van Leeuwen, Thomas

    2014-02-01

    About a 100 years ago, the Drosophila white mutant marked the birth of Drosophila genetics. The white gene turned out to encode the first well studied ABC transporter in arthropods. The ABC gene family is now recognized as one of the largest transporter families in all kingdoms of life. The majority of ABC proteins function as primary-active transporters that bind and hydrolyze ATP while transporting a large diversity of substrates across lipid membranes. Although extremely well studied in vertebrates for their role in drug resistance, less is known about the role of this family in the transport of endogenous and exogenous substances in arthropods. The ABC families of five insect species, a crustacean and a chelicerate have been annotated in some detail. We conducted a thorough phylogenetic analysis of the seven arthropod and human ABC protein subfamilies, to infer orthologous relationships that might suggest conserved function. Most orthologous relationships were found in the ABCB half transporter, ABCD, ABCE and ABCF subfamilies, but specific expansions within species and lineages are frequently observed and discussed. We next surveyed the role of ABC transporters in the transport of xenobiotics/plant allelochemicals and their involvement in insecticide resistance. The involvement of ABC transporters in xenobiotic resistance in arthropods is historically not well documented, but an increasing number of studies using unbiased differential gene expression analysis now points to their importance. We give an overview of methods that can be used to link ABC transporters to resistance. ABC proteins have also recently been implicated in the mode of action and resistance to Bt toxins in Lepidoptera. Given the enormous interest in Bt toxicology in transgenic crops, such findings will provide an impetus to further reveal the role of ABC transporters in arthropods. PMID:24291285

  8. Immunolocalization of serotonin in Onychophora argues against segmental ganglia being an ancestral feature of arthropods

    PubMed Central

    Mayer, Georg; Harzsch, Steffen

    2007-01-01

    Background Onychophora (velvet worms) represent the most basal arthropod group and play a pivotal role in the current discussion on the evolution of nervous systems and segmentation in arthropods. Although there is a wealth of information on the immunolocalization of serotonin (5-hydroxytryptamine, 5-HT) in various euarthropods, as yet no comparable localization data are available for Onychophora. In order to understand how the onychophoran nervous system compares to that of other arthropods, we studied the distribution of serotonin-like immunoreactive neurons and histological characteristics of ventral nerve cords in Metaperipatus blainvillei (Onychophora, Peripatopsidae) and Epiperipatus biolleyi (Onychophora, Peripatidae). Results We demonstrate that paired leg nerves are the only segmental structures associated with the onychophoran nerve cord. Although the median commissures and peripheral nerves show a repeated pattern, their arrangement is independent from body segments characterized by the position of legs and associated structures. Moreover, the somata of serotonin-like immunoreactive neurons do not show any ordered arrangement in both species studied but are instead scattered throughout the entire length of each nerve cord. We observed neither a serially iterated nor a bilaterally symmetric pattern, which is in contrast to the strictly segmental arrangement of serotonergic neurons in other arthropods. Conclusion Our histological findings and immunolocalization experiments highlight the medullary organization of the onychophoran nerve cord and argue against segmental ganglia of the typical euarthropodan type being an ancestral feature of Onychophora. These results contradict a priori assumptions of segmental ganglia being an ancestral feature of arthropods and, thus, weaken the traditional Articulata hypothesis, which proposes a sistergroup relationship of Annelida and Arthropoda. PMID:17629937

  9. Habitat connectivity shapes urban arthropod communities: the key role of green roofs.

    PubMed

    Braaker, S; Ghazoul, J; Obrist, M K; Moretti, M

    2014-04-01

    The installation of green roofs, defined here as rooftops with a shallow soil cover and extensive vegetation, has been proposed as a possible measure to mitigate the loss of green space caused by the steady growth of cities. However, the effectiveness of green roofs in supporting arthropod communities, and the extent to which they facilitate connectivity of these communities within the urban environment is currently largely unknown. We investigated the variation of species community composition (beta diversity) of four arthropod groups with contrasting mobility (Carabidae, Araneae, Curculionidae, and Apidae) on 40 green roofs and 40 extensively managed green sites on the ground in the city of Zurich, Switzerland. With redundancy analysis and variation partitioning, we (1) disentangled the relative importance of local environmental conditions, the surrounding land cover composition, and habitat connectivity on species community composition, (2) searched for specific spatial scales of habitat connectivity for the different arthropod groups, and (3) discussed the ecological and functional value of green roofs in cities. Our study revealed that on green roofs community composition of high-mobility arthropod groups (bees and weevils) were mainly shaped by habitat connectivity, while low-mobility arthropod groups (carabids and spiders) were more influenced by local environmental conditions. A similar but less pronounced pattern was found for ground communities. The high importance of habitat connectivity in shaping high-mobility species community composition indicates that these green roof communities are substantially connected by the frequent exchange of individuals among surrounding green roofs. On the other hand, low-mobility species communities on green roofs are more likely connected to ground sites than to other green roofs. The integration of green roofs in urban spatial planning strategies has great potential to enable higher connectivity among green spaces, so

  10. Comparative Genomics Reveals the Origins and Diversity of Arthropod Immune Systems.

    PubMed

    Palmer, William J; Jiggins, Francis M

    2015-08-01

    Insects are an important model for the study of innate immune systems, but remarkably little is known about the immune system of other arthropod groups despite their importance as disease vectors, pests, and components of biological diversity. Using comparative genomics, we have characterized the immune system of all the major groups of arthropods beyond insects for the first time--studying five chelicerates, a myriapod, and a crustacean. We found clear traces of an ancient origin of innate immunity, with some arthropods having Toll-like receptors and C3-complement factors that are more closely related in sequence or structure to vertebrates than other arthropods. Across the arthropods some components of the immune system, such as the Toll signaling pathway, are highly conserved. However, there is also remarkable diversity. The chelicerates apparently lack the Imd signaling pathway and beta-1,3 glucan binding proteins--a key class of pathogen recognition receptors. Many genes have large copy number variation across species, and this may sometimes be accompanied by changes in function. For example, we find that peptidoglycan recognition proteins have frequently lost their catalytic activity and switch between secreted and intracellular forms. We also find that there has been widespread and extensive duplication of the cellular immune receptor Dscam (Down syndrome cell adhesion molecule), which may be an alternative way to generate the high diversity produced by alternative splicing in insects. In the antiviral short interfering RNAi pathway Argonaute 2 evolves rapidly and is frequently duplicated, with a highly variable copy number. Our results provide a detailed analysis of the immune systems of several important groups of animals for the first time and lay the foundations for functional work on these groups. PMID:25908671

  11. Comparative Genomics Reveals the Origins and Diversity of Arthropod Immune Systems

    PubMed Central

    Palmer, William J.; Jiggins, Francis M.

    2015-01-01

    Insects are an important model for the study of innate immune systems, but remarkably little is known about the immune system of other arthropod groups despite their importance as disease vectors, pests, and components of biological diversity. Using comparative genomics, we have characterized the immune system of all the major groups of arthropods beyond insects for the first time—studying five chelicerates, a myriapod, and a crustacean. We found clear traces of an ancient origin of innate immunity, with some arthropods having Toll-like receptors and C3-complement factors that are more closely related in sequence or structure to vertebrates than other arthropods. Across the arthropods some components of the immune system, such as the Toll signaling pathway, are highly conserved. However, there is also remarkable diversity. The chelicerates apparently lack the Imd signaling pathway and beta-1,3 glucan binding proteins—a key class of pathogen recognition receptors. Many genes have large copy number variation across species, and this may sometimes be accompanied by changes in function. For example, we find that peptidoglycan recognition proteins have frequently lost their catalytic activity and switch between secreted and intracellular forms. We also find that there has been widespread and extensive duplication of the cellular immune receptor Dscam (Down syndrome cell adhesion molecule), which may be an alternative way to generate the high diversity produced by alternative splicing in insects. In the antiviral short interfering RNAi pathway Argonaute 2 evolves rapidly and is frequently duplicated, with a highly variable copy number. Our results provide a detailed analysis of the immune systems of several important groups of animals for the first time and lay the foundations for functional work on these groups. PMID:25908671

  12. Tyrosine Detoxification Is an Essential Trait in the Life History of Blood-Feeding Arthropods.

    PubMed

    Sterkel, Marcos; Perdomo, Hugo D; Guizzo, Melina G; Barletta, Ana Beatriz F; Nunes, Rodrigo D; Dias, Felipe A; Sorgine, Marcos H F; Oliveira, Pedro L

    2016-08-22

    Blood-feeding arthropods are vectors of infectious diseases such as dengue, Zika, Chagas disease, and malaria [1], and vector control is essential to limiting disease spread. Because these arthropods ingest very large amounts of blood, a protein-rich meal, huge amounts of amino acids are produced during digestion. Previous work on Rhodnius prolixus, a vector of Chagas disease, showed that, among all amino acids, only tyrosine degradation enzymes were overexpressed in the midgut compared to other tissues [2]. Here we demonstrate that tyrosine detoxification is an essential trait in the life history of blood-sucking arthropods. We found that silencing Rhodnius tyrosine aminotransferase (TAT) and 4-hydroxyphenylpyruvate dioxygenase (HPPD), the first two enzymes of the phenylalanine/tyrosine degradation pathway, caused the death of insects after a blood meal. This was confirmed by using the HPPD inhibitor mesotrione, which selectively killed hematophagous arthropods but did not affect non-hematophagous insects. In addition, mosquitoes and kissing bugs died after feeding on mice that had previously received a therapeutic effective oral dose (1 mg/kg) of nitisinone, another HPPD inhibitor used in humans for the treatment of tyrosinemia type I [3]. These findings indicate that HPPD (and TAT) can be a target for the selective control of blood-sucking disease vector populations. Because HPPD inhibitors are extensively used as herbicides and in medicine, these compounds may provide an alternative less toxic to humans and more environmentally friendly than the conventional neurotoxic insecticides that are currently used, with the ability to affect only hematophagous arthropods. PMID:27476595

  13. Arthropod prey for riparian associated birds in headwater forests of the Oregon Coast Range

    USGS Publications Warehouse

    Hagar, Joan C.; Li, Judith; Sobota, Janel; Jenkins, Stephanie

    2012-01-01

    Headwater riparian areas occupy a large proportion of the land base in Pacific Northwest forests, and thus are ecologically and economically important. Although a primary goal of management along small headwater streams is the protection of aquatic resources, streamside habitat also is important for many terrestrial wildlife species. However, mechanisms underlying the riparian associations of some terrestrial species have not been well studied, particularly for headwater drainages. We investigated the diets of and food availability for four bird species associated with riparian habitats in montane coastal forests of western Oregon, USA. We examined variation in the availability of arthropod prey as a function of distance from stream. Specifically, we tested the hypotheses that (1) emergent aquatic insects were a food source for insectivorous birds in headwater riparian areas, and (2) the abundances of aquatic and terrestrial arthropod prey did not differ between streamside and upland areas during the bird breeding season. We found that although adult aquatic insects were available for consumption throughout the study period, they represented a relatively small proportion of available prey abundance and biomass and were present in only 1% of the diet samples from only one of the four riparian-associated bird species. Nonetheless, arthropod prey, comprised primarily of insects of terrestrial origin, was more abundant in streamside than upland samples. We conclude that food resources for birds in headwater riparian areas are primarily associated with terrestrial vegetation, and that bird distributions along the gradient from streamside to upland may be related to variation in arthropod prey availability. Because distinct vegetation may distinguish riparian from upland habitats for riparian-associated birds and their terrestrial arthropod prey, we suggest that understory communities be considered when defining management zones for riparian habitat.

  14. Impact of Location, Cropping History, Tillage, and Chlorpyrifos on Soil Arthropods in Peanut.

    PubMed

    Cardoza, Yasmin J; Drake, Wendy L; Jordan, David L; Schroeder-Moreno, Michelle S; Arellano, Consuelo; Brandenburg, Rick L

    2015-08-01

    Demand for agricultural production systems that are both economically viable and environmentally conscious continues to increase. In recent years, reduced tillage systems, and grass and pasture rotations have been investigated to help maintain or improve soil quality, increase crop yield, and decrease labor requirements for production. However, documentation of the effects of reduced tillage, fescue rotation systems as well as other management practices, including pesticides, on pest damage and soil arthropod activity in peanut production for the Mid-Atlantic US region is still limited. Therefore, this project was implemented to assess impacts of fescue-based rotation systems on pests and other soil organisms when compared with cash crop rotation systems over four locations in eastern North Carolina. In addition, the effects of tillage (strip vs. conventional) and soil chlorpyrifos application on pod damage and soil-dwelling organisms were also evaluated. Soil arthropod populations were assessed by deploying pitfall traps containing 50% ethanol in each of the sampled plots. Results from the present study provide evidence that location significantly impacts pest damage and soil arthropod diversity in peanut fields. Cropping history also influenced arthropod diversity, with higher diversity in fescue compared with cash crop fields. Corn rootworm damage to pods was higher at one of our locations (Rocky Mount) compared with all others. Cropping history (fescue vs. cash crop) did not have an effect on rootworm damage, but increased numbers of hymenopterans, acarina, heteropterans, and collembolans in fescue compared with cash crop fields. Interestingly, there was an overall tendency for higher number of soil arthropods in traps placed in chlorpyrifos-treated plots compared with nontreated controls. PMID:26314040

  15. Mineral cycling in soil and litter arthropod food chains. Progress report, November 1, 1981-January 31, 1983

    SciTech Connect

    Crossley, D.A. Jr.

    1982-09-01

    Progress is reported for research projects on nutrient dynamics during terrestrial decomposition, as influenced by soil arthropods. Radioactive tracers are used as analogs of nutrients, to measure material movement along food chains and dynamics of processes during decomposition. Forest floor systems from which arthropods were excluded, or in which microfloral activity was depressed, trapped incoming nutrients from canopy throughfall at different rates. Faunal stimulation of microfloral activities could not be demonstrated, but drought conditions disturbed the experiment. Turnover measurements for radionuclides in collembolans are also reported, and compared with information on mites and other arthropods.

  16. Targeting arthropod subolesin/akirin for the development of a universal vaccine for control of vector infestations and pathogen transmission.

    PubMed

    de la Fuente, José; Moreno-Cid, Juan A; Canales, Mario; Villar, Margarita; de la Lastra, José M Pérez; Kocan, Katherine M; Galindo, Ruth C; Almazán, Consuelo; Blouin, Edmour F

    2011-09-01

    Diseases caused by arthropod-borne pathogens greatly impact on human and animal health. Recent research has provided evidence that tick protective antigens can be used for development of vaccines with the dual target of controlling arthropod infestations and reducing their vector capacity for pathogens. As reviewed herein, protective antigens such as subolesin/akirin, which are highly conserved across vector species, show promise for use in development of a universal vaccine for the control of arthropod infestations and the reduction of pathogen transmission. However, further research is needed in critical areas towards achieving this goal. PMID:21561715

  17. SEM characterization of anatomical variation in chitin organization in insect and arthropod cuticles.

    PubMed

    Chandran, Rakkiyappan; Williams, Lee; Hung, Albert; Nowlin, Kyle; LaJeunesse, Dennis

    2016-03-01

    The cuticles of insects and arthropods have some of the most diverse material properties observed in nature, so much so that it is difficult to imagine that all cutciles are primarily composed of the same two materials: a fibrous chitin network and a matrix composed of cuticle proteins. Various factors contribute to the mechanical and optical properties of an insect or arthropod cuticle including the thickness and composition. In this paper, we also identified another factor that may contribute to the optical, surface, and mechanical properties of a cuticle, i.e. the organization of chitin nanofibers and chitin fiber bundles. Self-assembled chitin nanofibers serve as the foundation for all higher order chitin structures in the cuticles of insects and other arthropods via interactions with structural cuticle proteins. Using a technique that enables the characterization of chitin organization in the cuticle of intact insects and arthropod exoskeletons, we demonstrate a structure/function correlation of chitin organization with larger scale anatomical structures. The chitin scaffolds in cuticles display an extraordinarily diverse set of morphologies that may reflect specific mechanical or physical properties. After removal of the proteinaceous and mineral matrix of a cuticle, we observe using SEM diverse nanoscale and micro scale organization of in-situ chitin in the wing, head, eye, leg, and dorsal and ventral thoracic regions of the periodical cicada Magicicada septendecim and in other insects and arthropods. The organization of chitin also appears to have a significant role in the organization of nanoscale surface structures. While microscale bristles and hairs have long been known to be chitin based materials formed as cellular extensions, we have found a nanostructured layer of chitin in the cuticle of the wing of the dog day annual cicada Tibicen tibicens, which may be the scaffold for the nanocone arrays found on the wing. We also use this process to examine

  18. Experimental and analytical evaluation of the effects of simulated engine inlets on the blade vibratory stresses of the SR-3 model prop-fan

    NASA Technical Reports Server (NTRS)

    Bansal, Prem N.

    1985-01-01

    A cooperative wind tunnel test program, referred to as GUN-3, had been conducted previously to assess the effect of inlet configuration and location on the inlet face pressure recovery and inlet drag in the presence of a high-speed advanced turboprop. These tests were conducted with the inlets located just downstream of the SR-3 model Prop-Fan, a moderately swept, eight-bladed 62.2 cm (24.5 inch) diameter advanced, high-speed turboprop model fabricated from titanium. During these tests, two blades of the SR-3 model Prop-Fan were strain gaged to measure the vibratory blade stresses occurring during the inlet aerodynamic test program. The purpose of the effort reported herein was to reduce and analyze the test results related to the vibratory strain gage measurements obtained. Three inlet configurations had been tested. These were: (1) single scoop, (2) twin scoop, and (3) annular. Each of the three inlets was tested at a position just behind the rotor. The single scoop inlet was also tested at a position further aft. Tests were also done without an inlet. These results emphasize the importance of avoiding critical speeds in the continuous operating range.

  19. Asexual Endophytes and Associated Alkaloids Alter Arthropod Community Structure and Increase Herbivore Abundances on a Native Grass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dispite their minute biomass, microbial symbionts of plants potentially alter herbivory, diversity and community structure. Infection of grasses by asexual endophytic fungi often decreases herbivore loads and alters arthropod diverisy. However, most studies to date have involved agronomic grasses ...

  20. Mineral cycling in soil and litter arthropod food chains. Progress report, November 1, 1979-October 31, 1980

    SciTech Connect

    Crossley, Jr, D A

    1980-08-01

    Recent progress and current status are reported for research concerned with mineral element dynamics in soil arthropod food chains. Research is performed within the larger context of terrestrial decomposition systems, in which soil arthropods may act as regulators of nutrient dynamics during decomposition. Research is measuring rates of nutrient accumulation and excretion by using radioactive tracer techniques with radioactive analogs of nutrients. Experimental measurement of radioactive tracer excretion and nutrient element pools are reported for soil microarthropods, using new methods of counting and microprobe elemental analysis. Research on arthropod-fungal relations is utilizing high-efficiency extraction followed by dissection of 13 x 13 cm soil blocks. A two-component excretion model is reported for Cobalt-60 in earthworms (Eisenia foetida), demonstrating that no assimilation of cobalt occurs from the mineral soil fraction but is entirely from organic matter. Collection of data sets on soil arthropod communities and abundances is completed.

  1. Non-Structural Proteins of Arthropod-Borne Bunyaviruses: Roles and Functions

    PubMed Central

    Eifan, Saleh; Schnettler, Esther; Dietrich, Isabelle; Kohl, Alain; Blomström, Anne-Lie

    2013-01-01

    Viruses within the Bunyaviridae family are tri-segmented, negative-stranded RNA viruses. The family includes several emerging and re-emerging viruses of humans, animals and plants, such as Rift Valley fever virus, Crimean-Congo hemorrhagic fever virus, La Crosse virus, Schmallenberg virus and tomato spotted wilt virus. Many bunyaviruses are arthropod-borne, so-called arboviruses. Depending on the genus, bunyaviruses encode, in addition to the RNA-dependent RNA polymerase and the different structural proteins, one or several non-structural proteins. These non-structural proteins are not always essential for virus growth and replication but can play an important role in viral pathogenesis through their interaction with the host innate immune system. In this review, we will summarize current knowledge and understanding of insect-borne bunyavirus non-structural protein function(s) in vertebrate, plant and arthropod. PMID:24100888

  2. [What gene and chromosomes say about the origin and evolution of insects and other arthropods].

    PubMed

    Lukhtanov, V A; Kuznetsova, V G

    2010-09-01

    At the turn of the 21st century, the use of molecular and molecular cytogenetic methods led to revolutionary advances in systematics of insects and other arthropods. Analysis of nuclear and mitochondrial genes, as well as investigation of structural rearrangements in the mitochondrial chromosome convincingly supported the Pancrustacea hypothesis, according to which insects originated directly from crustaceans, whereas myriapods are not closely related to them. The presence of the specific telomeric motif TTAGG confirmed the monophyletic origin of arthropods (Arthropoda) and the assignment of tongue worms (Pentastomida) to this type. Several different types of telomeric sequences have been found within the class of insects. Investigation of the molecular organization of these sequences may shed light on the relationships between the orders Diptera, Siphonaptera, and Mecoptera and on the origin of such enigmatic groups as the orders Strepsiptera, Zoraptera and suborder Coleorrhyncha. PMID:21061630

  3. Early land animals in north america: evidence from devonian age arthropods from gilboa, new york.

    PubMed

    Shear, W A; Bonamo, P M; Grierson, J D; Rolfe, W D; Smith, E L; Norton, R A

    1984-05-01

    A new fossil site near Gilboa, New York, is one of only three where fossils of terrestrial arthropods of Devonian age have been found. The new Gilboan fauna is younger than the other two but richer in taxa. Fragmentary remains and nearly whole specimens assigned to Eurypterida, Arachnida (Trigonotarbida, Araneae, Amblypygi, and Acari), Chilopoda [Craterostigmatomorpha(?) and Scuterigeromorpha(?)], and tentatively to Insecta (Archaeognatha) have been found. The centipedes and possible insects may represent the earliest records known for these groups. PMID:17753774

  4. Avirulence effector discovery in a plant galling and plant parasitic arthropod, the Hessian fly (Mayetiola destructor).

    PubMed

    Aggarwal, Rajat; Subramanyam, Subhashree; Zhao, Chaoyang; Chen, Ming-Shun; Harris, Marion O; Stuart, Jeff J

    2014-01-01

    Highly specialized obligate plant-parasites exist within several groups of arthropods (insects and mites). Many of these are important pests, but the molecular basis of their parasitism and its evolution are poorly understood. One hypothesis is that plant parasitic arthropods use effector proteins to defeat basal plant immunity and modulate plant growth. Because avirulence (Avr) gene discovery is a reliable method of effector identification, we tested this hypothesis using high-resolution molecular genetic mapping of an Avr gene (vH13) in the Hessian fly (HF, Mayetiola destructor), an important gall midge pest of wheat (Triticum spp.). Chromosome walking resolved the position of vH13, and revealed alleles that determine whether HF larvae are virulent (survive) or avirulent (die) on wheat seedlings carrying the wheat H13 resistance gene. Association mapping found three independent insertions in vH13 that appear to be responsible for H13-virulence in field populations. We observed vH13 transcription in H13-avirulent larvae and the salivary glands of H13-avirulent larvae, but not in H13-virulent larvae. RNA-interference-knockdown of vH13 transcripts allowed some H13-avirulent larvae to escape H13-directed resistance. vH13 is the first Avr gene identified in an arthropod. It encodes a small modular protein with no sequence similarities to other proteins in GenBank. These data clearly support the hypothesis that an effector-based strategy has evolved in multiple lineages of plant parasites, including arthropods. PMID:24964065

  5. Species richness-environment relationships of European arthropods at two spatial grains: habitats and countries.

    PubMed

    Entling, Martin H; Schweiger, Oliver; Bacher, Sven; Espadaler, Xavier; Hickler, Thomas; Kumschick, Sabrina; Woodcock, Ben A; Nentwig, Wolfgang

    2012-01-01

    We study how species richness of arthropods relates to theories concerning net primary productivity, ambient energy, water-energy dynamics and spatial environmental heterogeneity. We use two datasets of arthropod richness with similar spatial extents (Scandinavia to Mediterranean), but contrasting spatial grain (local habitat and country). Samples of ground-dwelling spiders, beetles, bugs and ants were collected from 32 paired habitats at 16 locations across Europe. Species richness of these taxonomic groups was also determined for 25 European countries based on the Fauna Europaea database. We tested effects of net primary productivity (NPP), annual mean temperature (T), annual rainfall (R) and potential evapotranspiration of the coldest month (PET(min)) on species richness and turnover. Spatial environmental heterogeneity within countries was considered by including the ranges of NPP, T, R and PET(min). At the local habitat grain, relationships between species richness and environmental variables differed strongly between taxa and trophic groups. However, species turnover across locations was strongly correlated with differences in T. At the country grain, species richness was significantly correlated with environmental variables from all four theories. In particular, species richness within countries increased strongly with spatial heterogeneity in T. The importance of spatial heterogeneity in T for both species turnover across locations and for species richness within countries suggests that the temperature niche is an important determinant of arthropod diversity. We suggest that, unless climatic heterogeneity is constant across sampling units, coarse-grained studies should always account for environmental heterogeneity as a predictor of arthropod species richness, just as studies with variable area of sampling units routinely consider area. PMID:23029288

  6. Species Richness-Environment Relationships of European Arthropods at Two Spatial Grains: Habitats and Countries

    PubMed Central

    Entling, Martin H.; Schweiger, Oliver; Bacher, Sven; Espadaler, Xavier; Hickler, Thomas; Kumschick, Sabrina; Woodcock, Ben A.; Nentwig, Wolfgang

    2012-01-01

    We study how species richness of arthropods relates to theories concerning net primary productivity, ambient energy, water-energy dynamics and spatial environmental heterogeneity. We use two datasets of arthropod richness with similar spatial extents (Scandinavia to Mediterranean), but contrasting spatial grain (local habitat and country). Samples of ground-dwelling spiders, beetles, bugs and ants were collected from 32 paired habitats at 16 locations across Europe. Species richness of these taxonomic groups was also determined for 25 European countries based on the Fauna Europaea database. We tested effects of net primary productivity (NPP), annual mean temperature (T), annual rainfall (R) and potential evapotranspiration of the coldest month (PETmin) on species richness and turnover. Spatial environmental heterogeneity within countries was considered by including the ranges of NPP, T, R and PETmin. At the local habitat grain, relationships between species richness and environmental variables differed strongly between taxa and trophic groups. However, species turnover across locations was strongly correlated with differences in T. At the country grain, species richness was significantly correlated with environmental variables from all four theories. In particular, species richness within countries increased strongly with spatial heterogeneity in T. The importance of spatial heterogeneity in T for both species turnover across locations and for species richness within countries suggests that the temperature niche is an important determinant of arthropod diversity. We suggest that, unless climatic heterogeneity is constant across sampling units, coarse-grained studies should always account for environmental heterogeneity as a predictor of arthropod species richness, just as studies with variable area of sampling units routinely consider area. PMID:23029288

  7. Changes in arthropod assemblages along a wide gradient of disturbance in Gabon.

    PubMed

    Basset, Yves; Missa, Olivier; Alonso, Alfonso; Miller, Scott E; Curletti, Gianfranco; De Meyer, Marc; Eardley, Connal; Lewis, Owen T; Mansell, Mervyn W; Novotny, Vojtech; Wagner, Thomas

    2008-12-01

    Searching for indicator taxa representative of diverse assemblages, such as arthropods, is an important objective of many conservation studies. We evaluated the impacts of a wide gradient of disturbance in Gabon on a range of arthropod assemblages representing different feeding guilds. We examined 4 x 10(5) arthropod individuals from which 21 focal taxa were separated into 1534 morphospecies. Replication included the understory of 3 sites in each of 4 different stages of forest succession and land use (i.e., habitats) after logging (old and young forests, savanna, and gardens). We used 3 complementary sampling methods to survey sites throughout the year. Overall differences in arthropod abundance and diversity were greatest between forest and open habitats, and cleared forest invaded by savanna had the lowest abundance and diversity. The magnitude of faunal differences was much smaller between old and young forests. When considered at this local scale, anthropogenic modification of habitats did not result in a monotonous decline of diversity because many herbivore pests and their associated predators and parasitoids were abundant and diverse in gardens, where plant productivity was kept artificially high year-round through watering and crop rotation. We used a variety of response variables to measure the strength of correlations across survey locations among focal taxa. These could be ranked as follows in terms of decreasing number of significant correlations: species turnover > abundance > observed species richness > estimated species richness > percentage of site-specific species. The number of significant correlations was generally low and apparently unrelated to taxonomy or guild structure. Our results emphasize the value of reporting species turnover in conservation studies, as opposed to simply measuring species richness, and that the search for indicator taxa is elusive in the tropics. One promising alternative might be to consider "predictor sets" of a

  8. Diverse urban plantings managed with sufficient resource availability can increase plant productivity and arthropod diversity

    PubMed Central

    Muller, Jonathon N.; Loh, Susan; Braggion, Ligia; Cameron, Stephen; Firn, Jennifer L.

    2014-01-01

    Buildings structures and surfaces are explicitly being used to grow plants, and these “urban plantings” are generally designed for aesthetic value. Urban plantings also have the potential to contribute significant “ecological values” by increasing urban habitat for animals such as arthropods and by increasing plant productivity. In this study, we evaluated how the provision of these additional ecological values is affected by plant species richness; the availability of essential resources for plants, such as water, light, space; and soil characteristics. We sampled 33 plantings located on the exterior of three buildings in the urban center of Brisbane, Australia (subtropical climatic region) over 2, 6 week sampling periods characterized by different temperature and rainfall conditions. Plant cover was estimated as a surrogate for productivity as destructive sampling of biomass was not possible. We measured weekly light levels (photosynthetically active radiation), plant CO2 assimilation, soil CO2 efflux, and arthropod diversity. Differences in plant cover were best explained by a three-way interaction of plant species richness, management water regime and sampling period. As the richness of plant species increased in a planter, productivity and total arthropod richness also increased significantly—likely due to greater habitat heterogeneity and quality. Overall we found urban plantings can provide additional ecological values if essential resources are maintained within a planter such as water, light and soil temperature. Diverse urban plantings that are managed with these principles in mind can contribute to the attraction of diverse arthropod communities, and lead to increased plant productivity within a dense urban context. PMID:25400642

  9. The Interactive Effects of Pulsed Grazing Disturbance and Patch Size Vary among Wetland Arthropod Guilds

    PubMed Central

    Armitage, Anna R.; Ho, Chuan-Kai; Quigg, Antonietta

    2013-01-01

    Pulse disturbances and habitat patch size can determine community composition independently or in concert, and may be particularly influential on small spatial scales for organisms with low mobility. In a field experiment, we investigated whether the effects of a pulsed disturbance that simulated a grazing event varied with habitat patch size. We focused on the short-term responses of multiple co-occurring emergent salt marsh arthropods with differing levels of mobility and dispersal potential. As part of a marsh restoration project, two types of emergent marsh structures were created: small circular mounds (0.5 m diameter) separated by several meters of aquatic habitat, and larger, elongated terraces (>50 m long). Study plots (0.25 m2) were established on both structures; in a subset of plots, we simulated a pulsed grazing disturbance event by clipping the aboveground tissue of emergent plants, primarily Spartina alterniflora. At the end of the two-month recovery period, Ischnodemus (Hemiptera: Blissidae) density was over 50% lower in disturbed treatments within both large (terrace) and small (mound) patches. Predatory spider treatment responses were similar to Ischnodemus responses, suggesting a trophic relationship between those two arthropod groups. Alternatively, spiders may have been directly affected by the loss of shelter in the disturbed plots. Prokelisia (Homoptera: Delphacidae), which are generally more mobile than Ischnodemus, were not affected by disturbance treatment or by patch size, suggesting the potential for rapid recolonization following disturbance. Larval stem borers decreased by an order of magnitude in disturbed plots, but only in the large patches. In general, the disturbance effects of vegetation removal on arthropod density and community composition were stronger than patch size effects, and there were few interactions between pulsed disturbance and patch size. Rather, emergent marsh arthropod responses to disturbance and habitat area

  10. Avirulence Effector Discovery in a Plant Galling and Plant Parasitic Arthropod, the Hessian Fly (Mayetiola destructor)

    PubMed Central

    Aggarwal, Rajat; Subramanyam, Subhashree; Zhao, Chaoyang; Chen, Ming-Shun; Harris, Marion O.; Stuart, Jeff J.

    2014-01-01

    Highly specialized obligate plant-parasites exist within several groups of arthropods (insects and mites). Many of these are important pests, but the molecular basis of their parasitism and its evolution are poorly understood. One hypothesis is that plant parasitic arthropods use effector proteins to defeat basal plant immunity and modulate plant growth. Because avirulence (Avr) gene discovery is a reliable method of effector identification, we tested this hypothesis using high-resolution molecular genetic mapping of an Avr gene (vH13) in the Hessian fly (HF, Mayetiola destructor), an important gall midge pest of wheat (Triticum spp.). Chromosome walking resolved the position of vH13, and revealed alleles that determine whether HF larvae are virulent (survive) or avirulent (die) on wheat seedlings carrying the wheat H13 resistance gene. Association mapping found three independent insertions in vH13 that appear to be responsible for H13-virulence in field populations. We observed vH13 transcription in H13-avirulent larvae and the salivary glands of H13-avirulent larvae, but not in H13-virulent larvae. RNA-interference-knockdown of vH13 transcripts allowed some H13-avirulent larvae to escape H13-directed resistance. vH13 is the first Avr gene identified in an arthropod. It encodes a small modular protein with no sequence similarities to other proteins in GenBank. These data clearly support the hypothesis that an effector-based strategy has evolved in multiple lineages of plant parasites, including arthropods. PMID:24964065

  11. The Effects of Timing of Grazing on Plant and Arthropod Communities in High-Elevation Grasslands

    PubMed Central

    Davis, Stacy C.; Burkle, Laura A.; Cross, Wyatt F.; Cutting, Kyle A.

    2014-01-01

    Livestock grazing can be used as a key management tool for maintaining healthy ecosystems. However, the effectiveness of using grazing to modify habitat for species of conservation concern depends on how the grazing regime is implemented. Timing of grazing is one grazing regime component that is less understood than grazing intensity and grazer identity, but is predicted to have important implications for plant and higher trophic level responses. We experimentally assessed how timing of cattle grazing affected plant and arthropod communities in high-elevation grasslands of southwest Montana to better evaluate its use as a tool for multi-trophic level management. We manipulated timing of grazing, with one grazing treatment beginning in mid-June and the other in mid-July, in two experiments conducted in different grassland habitat types (i.e., wet meadow and upland) in 2011 and 2012. In the upland grassland experiment, we found that both early and late grazing treatments reduced forb biomass, whereas graminoid biomass was only reduced with late grazing. Grazing earlier in the growing season versus later did not result in greater recovery of graminoid or forb biomass as expected. In addition, the density of the most ubiquitous grassland arthropod order (Hemiptera) was reduced by both grazing treatments in upland grasslands. A comparison of end-of-season plant responses to grazing in upland versus wet meadow grasslands revealed that grazing reduced graminoid biomass in the wet meadow and forb biomass in the upland, irrespective of timing of grazing. Both grazing treatments also reduced end-of-season total arthropod and Hemiptera densities and Hemiptera biomass in both grassland habitat types. Our results indicate that both early and late season herbivory affect many plant and arthropod characteristics in a similar manner, but grazing earlier may negatively impact species of conservation concern requiring forage earlier in the growing season. PMID:25338008

  12. Deep-time patterns of tissue consumption by terrestrial arthropod herbivores.

    PubMed

    Labandeira, Conrad C

    2013-04-01

    A survey of the fossil record of land-plant tissues and their damage by arthropods reveals several results that shed light on trophic trends in host-plant resource use by arthropods. All 14 major plant tissues were present by the end of the Devonian, representing the earliest 20% of the terrestrial biota. During this interval, two types of time lags separate the point between when tissues first originated from their earliest consumption by herbivorous arthropods. For epidermis, parenchyma, collenchyma and xylem, live tissue consumption was rapid, occurring on average 10 m.y. after the earliest tissue records. By contrast, structural tissues (periderm, sclerenchyma), tissues with actively dividing cells (apical, lateral, intercalary meristems), and reproductive tissues (spores, megagametophytes, integuments) experienced approximately a 9-fold (92 m.y.) delay in arthropod herbivory, extending well into the Carboniferous Period. Phloem similarly presents a delay of 85 m.y., but this incongruously long lag-time may be attributed to the lack of preservation of this tissue in early vascular plants. Nevertheless, the presence of phloem can be indicated from planar spaces adjacent well-preserved xylem, or inferred from a known anatomy of the same plant taxon in better preserved material, especially permineralisations. The trophic partitioning of epidermis, parenchyma, phloem and xylem increases considerably to the present, probably a consequence of dietary specialization or consumption of whole leaves by several herbivore functional feeding groups. Structural tissues, meristematic tissues and reproductive tissues minimally have been consumed throughout the fossil record, consistent with their long lags to herbivory during the earlier Paleozoic. Neither angiosperm dominance in floras nor global environmental perturbations had any discernible effect on herbivore trophic partitioning of plant tissues. PMID:23525577

  13. The value of urban vacant land to support arthropod biodiversity and ecosystem services.

    PubMed

    Gardiner, Mary M; Burkman, Caitlin E; Prajzner, Scott P

    2013-12-01

    The expansion of urban areas is occurring globally, but not all city neighborhoods are gaining population. Because of economic decline and the recent foreclosure crisis, many U.S. cities are demolishing abandoned residential structures to create parcels of vacant land. In some cities, weak housing markets have, or will likely, recover in the near term, and these parcels will be redeveloped. However, in other cities, large numbers of abandoned parcels have no significant market value and no likelihood of near-term redevelopment. The creation of these vacated green spaces could offer opportunities to preserve declining species, restore ecosystem functions, and support diverse ecosystem services. Arthropods are an important indicator of the ability of urban vacant land to serve multiple functions, from conservation to food production. Across Europe, vacant lands have been found to support a diversity of rare species, and similar examinations of arthropods within this habitat are underway in the United States. In addition, using vacant land as a resource for local food production is growing rapidly worldwide. Arthropods play key roles in the sustainability of food production in cities, and land conversion to farming has been found to influence their community composition and function. A greater focus on quantifying the current ecological value of vacant land and further assessment of how changes in its ecosystem management affect biodiversity and ecosystem processes is clearly needed. Herein, we specifically focus on the role of arthropods in addressing these priorities to advance our ecological understanding of the functional role of vacant land habitats in cities. PMID:24468552

  14. Deep-time patterns of tissue consumption by terrestrial arthropod herbivores

    NASA Astrophysics Data System (ADS)

    Labandeira, Conrad C.

    2013-04-01

    A survey of the fossil record of land-plant tissues and their damage by arthropods reveals several results that shed light on trophic trends in host-plant resource use by arthropods. All 14 major plant tissues were present by the end of the Devonian, representing the earliest 20 % of the terrestrial biota. During this interval, two types of time lags separate the point between when tissues first originated from their earliest consumption by herbivorous arthropods. For epidermis, parenchyma, collenchyma and xylem, live tissue consumption was rapid, occurring on average 10 m.y. after the earliest tissue records. By contrast, structural tissues (periderm, sclerenchyma), tissues with actively dividing cells (apical, lateral, intercalary meristems), and reproductive tissues (spores, megagametophytes, integuments) experienced approximately a 9-fold (92 m.y.) delay in arthropod herbivory, extending well into the Carboniferous Period. Phloem similarly presents a delay of 85 m.y., but this incongruously long lag-time may be attributed to the lack of preservation of this tissue in early vascular plants. Nevertheless, the presence of phloem can be indicated from planar spaces adjacent well-preserved xylem, or inferred from a known anatomy of the same plant taxon in better preserved material, especially permineralisations. The trophic partitioning of epidermis, parenchyma, phloem and xylem increases considerably to the present, probably a consequence of dietary specialization or consumption of whole leaves by several herbivore functional feeding groups. Structural tissues, meristematic tissues and reproductive tissues minimally have been consumed throughout the fossil record, consistent with their long lags to herbivory during the earlier Paleozoic. Neither angiosperm dominance in floras nor global environmental perturbations had any discernible effect on herbivore trophic partitioning of plant tissues.

  15. Arthropod but not bird predation in ethiopian homegardens is higher in tree-poor than in tree-rich landscapes.

    PubMed

    Lemessa, Debissa; Hambäck, Peter A; Hylander, Kristoffer

    2015-01-01

    Bird and arthropod predation is often associated with natural pest control in agricultural landscapes, but the rates of predation may vary with the amount of tree cover or other environmental factors. We examined bird and arthropod predation in three tree-rich and three tree-poor landscapes across southwestern Ethiopia. Within each landscape we selected three tree-rich and three tree-poor homegardens in which we recorded the number of tree species and tree stems within 100 × 100 m surrounding the central house. To estimate predation rates, we attached plasticine caterpillars on leaves of two coffee and two avocado shrubs in each homegarden, and recorded the number of attacked caterpillars for 7-9 consecutive weeks. The overall mean daily predation rate was 1.45% for birds and 1.60% for arthropods. The rates of arthropod predation varied among landscapes and were higher in tree-poor landscapes. There was no such difference for birds. Within landscapes, predation rates from birds and arthropods did not vary between tree-rich and tree-poor homegardens in either tree-rich or tree-poor landscapes. The most surprising result was the lack of response by birds to tree cover at either spatial scale. Our results suggest that in tree-poor landscapes there are still enough non-crop habitats to support predatory arthropods and birds to deliver strong top-down effect on crop pests. PMID:25961306

  16. Arthropods of Rose Atoll with special reference to ants and Pulvinaria Urbicola Scales (Hempitera Coccidae) on Pisonia Grandis trees

    USGS Publications Warehouse

    Banko, Paul C.; Peck, Robert W.; Pendleton, Frank; Schmaedick, Mark; Ernsberger, Kelsie

    2014-01-01

    Rose Atoll, at the eastern end of the Samoan Archipelago, is a small but important refuge for seabirds, shorebirds, and sea turtles. While the vertebrate community is relatively well-studied, the terrestrial arthropod fauna, and its role in ecosystem function, are poorly known. Arthropods may be influencing the decline of Pisonia grandis, an ecologically important tree that once dominated the 6.6 ha of land on Rose Atoll. Reasons for the decline are not fully understood but a facultative relationship between two invasive arthropods, the soft scale Pulvinaria urbicola and ants, likely has contributed to tree death. The primary objectives of this study were to systematically survey the terrestrial arthropod fauna and identify ant species that tend scales on Pisonia. Using an array of standard arthropod collecting techniques, at least 73 species from 20 orders were identified, including nine ant species. Of the ants collected, only Tetramorium bicarinatum and T. simillimum were observed tending scales on Pisonia. No known natural enemies of Pulvinaria scales were found, suggesting little predation on scale populations. Treatment of Pisonia with the systemic insecticide imidacloprid failed to eliminate Pulvinaria scales, although short-term suppression apparently occurred. The arthropod fauna of Rose Atoll is dominated by exotic species that likely have a significant impact on the structure and function of the island’s ecosystem.

  17. Arthropod but Not Bird Predation in Ethiopian Homegardens Is Higher in Tree-Poor than in Tree-Rich Landscapes

    PubMed Central

    Lemessa, Debissa; Hambäck, Peter A.; Hylander, Kristoffer

    2015-01-01

    Bird and arthropod predation is often associated with natural pest control in agricultural landscapes, but the rates of predation may vary with the amount of tree cover or other environmental factors. We examined bird and arthropod predation in three tree-rich and three tree-poor landscapes across southwestern Ethiopia. Within each landscape we selected three tree-rich and three tree-poor homegardens in which we recorded the number of tree species and tree stems within 100 × 100 m surrounding the central house. To estimate predation rates, we attached plasticine caterpillars on leaves of two coffee and two avocado shrubs in each homegarden, and recorded the number of attacked caterpillars for 7–9 consecutive weeks. The overall mean daily predation rate was 1.45% for birds and 1.60% for arthropods. The rates of arthropod predation varied among landscapes and were higher in tree-poor landscapes. There was no such difference for birds. Within landscapes, predation rates from birds and arthropods did not vary between tree-rich and tree-poor homegardens in either tree-rich or tree-poor landscapes. The most surprising result was the lack of response by birds to tree cover at either spatial scale. Our results suggest that in tree-poor landscapes there are still enough non-crop habitats to support predatory arthropods and birds to deliver strong top-down effect on crop pests. PMID:25961306

  18. Spatial heterogeneity in the relative impacts of foliar quality and predation pressure on red oak, Quercus rubra, arthropod communities.

    PubMed

    Zehnder, Caralyn B; Stodola, Kirk W; Cooper, Robert J; Hunter, Mark D

    2010-12-01

    Predation pressure and resource availability often interact in structuring herbivore communities, with their relative influence varying in space and time. The operation of multiple ecological pressures and guild-specific herbivore responses may combine to override simple predictions of how the roles of plant quality and predation pressure vary in space. For 2 years at the Coweeta LTER in the Southern Appalachian Mountains, we conducted a bird exclosure experiment on red oak (Quercus rubra) saplings to investigate the effects of bird predation on red oak arthropod communities. We established bird exclosures at six sites along an elevational gradient and estimated variation in foliar nitrogen and bird predation pressure along this gradient. Foliar nitrogen concentrations increased with elevation while our index of bird predation pressure was variable across sites. Greater arthropod densities were detected inside exclosures; however, this result was mainly driven by the response of phloem feeders which were much more prevalent inside exclosures than on control trees. There was little evidence for an effect of bird predation on the other arthropod guilds. Consequently, there was no evidence of a trophic cascade either in terms of leaf damage or tree growth. Finally, we found more variation in arthropod density among trees within sites than variation in arthropod density among sites, indicating the importance of micro-site variation in structuring arthropod communities. PMID:20711610

  19. [Community structure and its dynamics of predatory arthropod in jujube orchards intercropped with different herbage species].

    PubMed

    Shi, Guanglu; Wang, Younian; Miao, Zhenwang; Li, Dengke; Zhang, Tieqiang; Yu, Tongquan; Ji, Qianlong; Dong, Hui

    2006-11-01

    By using community structural characteristic indices and principal component analysis, this paper studied the community structure and its dynamics of predatory arthropod in the jujube orchards intercropped with Astrugalus complanatus, Trifolium repen, Lotus comiculotus, and Medicago sativa. The results showed that in all test jujube orchards, spider and predatory insects were the predominant components of the predatory arthropod community, and their relative abundances were 48.3% - 52.7% and 38.8% - 44.4% , respectively. There were significant differences (P < 0.05) in the mean density, diversity, and evenness of the most common predatory arthropod groups in the jujube orchards intercropped with different herbage species, with the sequence of intercropped with Lotus comiculotus > Medicago sativa > Astrugalus complanatu > Trifolium repens, but for dominant concentration index, the sequence was intercropped with Trifolium repens > Astrugalus complanatu > Medicago sativa > Lotus comiculotus. The average density of predatory spiders was significant higher (P < 0.05) than that of predatory insects in all test jujube orchards. The individuals of Coccinellidae, Pentatomidae, inoccllidae, Chrysopidae, Thomisidae, Araneidae and Phytoseiidae played the dominant role in the community. PMID:17269332

  20. Structural Diversity of Arthropod Biophotonic Nanostructures Spans Amphiphilic Phase-Space

    SciTech Connect

    Saranathan, Vinod Kumar; Seago, Ainsley E.; Sandy, Alec; Narayanan, Suresh; Mochrie, Simon G.J.; Dufresne, Eric R.; Cao, Hui; Osuji, Chinedum O.; Prum, Richard Owen

    2015-05-04

    Many organisms, especially arthropods, produce vivid interference colors using diverse mesoscopic (100-350 nm) integumentary biophotonic nanostructures that are increasingly being investigated for technological applications. Despite a century of interest, precise structural knowledge of many biophotonic nanostructures and the mechanisms controlling their development remain tentative, when such knowledge can open novel biomimetic routes to facilely self-assemble tunable, multifunctional materials. Here, we use synchrotron small-angle X-ray scattering and electron microscopy to characterize the photonic nanostructure of 140 integumentary scales and setae from ~127 species of terrestrial arthropods in 85 genera from 5 orders. We report a rich nanostructural diversity, including triply periodic bicontinuous networks, close-packed spheres, inverse columnar, perforated lamellar, and disordered spongelike morphologies, commonly observed as stable phases of amphiphilic surfactants, block copolymer, and lyotropic lipid-water systems. Diverse arthropod lineages appear to have independently evolved to utilize the self-assembly of infolding lipid-bilayer membranes to develop biophotonic nanostructures that span the phase-space of amphiphilic morphologies, but at optical length scales.

  1. Arthropod visual predators in the early pelagic ecosystem: evidence from the Burgess Shale and Chengjiang biotas.

    PubMed

    Vannier, J; García-Bellido, D C; Hu, S-X; Chen, A-L

    2009-07-22

    Exceptional fossil specimens with preserved soft parts from the Maotianshan Shale (ca 520 Myr ago) and the Burgess Shale (505 Myr ago) biotas indicate that the worldwide distributed bivalved arthropod Isoxys was probably a non-benthic visual predator. New lines of evidence come from the functional morphology of its powerful prehensile frontal appendages that, combined with large spherical eyes, are thought to have played a key role in the recognition and capture of swimming or epibenthic prey. The swimming and steering of this arthropod was achieved by the beating of multiple setose exopods and a flap-like telson. The appendage morphology of Isoxys indicates possible phylogenetical relationships with the megacheirans, a widespread group of assumed predator arthropods characterized by a pre-oral 'great appendage'. Evidence from functional morphology and taphonomy suggests that Isoxys was able to migrate through the water column and was possibly exploiting hyperbenthic niches for food. Although certainly not unique, the case of Isoxys supports the idea that off-bottom animal interactions such as predation, associated with complex feeding strategies and behaviours (e.g. vertical migration and hunting) were established by the Early Cambrian. It also suggests that a prototype of a pelagic food chain had already started to build-up at least in the lower levels of the water column. PMID:19403536

  2. Arthropod visual predators in the early pelagic ecosystem: evidence from the Burgess Shale and Chengjiang biotas

    PubMed Central

    Vannier, J.; García-Bellido, D.C.; Hu, S.-X.; Chen, A.-L.

    2009-01-01

    Exceptional fossil specimens with preserved soft parts from the Maotianshan Shale (ca 520 Myr ago) and the Burgess Shale (505 Myr ago) biotas indicate that the worldwide distributed bivalved arthropod Isoxys was probably a non-benthic visual predator. New lines of evidence come from the functional morphology of its powerful prehensile frontal appendages that, combined with large spherical eyes, are thought to have played a key role in the recognition and capture of swimming or epibenthic prey. The swimming and steering of this arthropod was achieved by the beating of multiple setose exopods and a flap-like telson. The appendage morphology of Isoxys indicates possible phylogenetical relationships with the megacheirans, a widespread group of assumed predator arthropods characterized by a pre-oral ‘great appendage’. Evidence from functional morphology and taphonomy suggests that Isoxys was able to migrate through the water column and was possibly exploiting hyperbenthic niches for food. Although certainly not unique, the case of Isoxys supports the idea that off-bottom animal interactions such as predation, associated with complex feeding strategies and behaviours (e.g. vertical migration and hunting) were established by the Early Cambrian. It also suggests that a prototype of a pelagic food chain had already started to build-up at least in the lower levels of the water column. PMID:19403536

  3. Arthropod phylogeny: onychophoran brain organization suggests an archaic relationship with a chelicerate stem lineage.

    PubMed

    Strausfeld, Nicholas J; Strausfeld, Camilla Mok; Loesel, Rudi; Rowell, David; Stowe, Sally

    2006-08-01

    Neuroanatomical studies have demonstrated that the architecture and organization among neuropils are highly conserved within any order of arthropods. The shapes of nerve cells and their neuropilar arrangements provide robust characters for phylogenetic analyses. Such analyses so far have agreed with molecular phylogenies in demonstrating that entomostracans+malacostracans belong to a clade (Tetraconata) that includes the hexapods. However, relationships among what are considered to be paraphyletic groups or among the stem arthropods have not yet been satisfactorily resolved. The present parsimony analyses of independent neuroarchitectural characters from 27 arthropods and lobopods demonstrate relationships that are congruent with phylogenies derived from molecular studies, except for the status of the Onychophora. The present account describes the brain of the onychophoran Euperipatoides rowelli, demonstrating that the structure and arrangements of its neurons, cerebral neuropils and sensory centres are distinct from arrangements in the brains of mandibulates. Neuroanatomical evidence suggests that the organization of the onychophoran brain is similar to that of the brains of chelicerates. PMID:16822744

  4. Red imported fire ant impacts on upland arthropods in Southern Mississippi

    USGS Publications Warehouse

    Epperson, D.M.; Allen, C.R.

    2010-01-01

    Red imported fire ants (Solenopsis invicta) have negative impacts on a broad array of invertebrate species. We investigated the impacts of fire ants on the upland arthropod community on 20???40 ha study sites in southern Mississippi. Study sites were sampled from 19972000 before, during, and after fire ant bait treatments to reduce fire ant populations. Fire ant abundance was assessed with bait transects on all sites, and fire ant population indices were estimated on a subset of study sites. Species richness and diversity of other ant species was also assessed from bait transects. Insect biomass and diversity was determined from light trap samples. Following treatments, fire ant abundance and population indices were significantly reduced, and ant species diversity and richness were greater on treated sites. Arthropod biomass, species diversity and species richness estimated from light trap samples were negatively correlated with fire ant abundance, but there were no observable treatment effects. Solenopsis invicta has the potential to negatively impact native arthropod communities resulting in a potential loss of both species and function.

  5. Efficient sampling of ground-dwelling arthropods using pitfall traps in arid steppes.

    PubMed

    Cheli, Germán H; Corley, Juan C

    2010-01-01

    Pitfall trapping is probably the most frequently used method for sampling ground-dwelling arthropods. While the capture of specimens in pitfall traps largely depends on the number of individuals in the sampled area, trap design and trapping effort for a given environment, can also affect sampling success. The aim of this study was to determine the best pitfall trapping design for collecting ground-dwelling arthropods in the wind-blown and cold arid steppe areas of Patagonia. We tested four designs of traps, six types of preservative and different times of activation as well as the quantity of traps. Both preservation attributes and sampling efficiency differed between different trap designs and fluids compared. We conclude that in order to obtain reliable data on the structure of a community of ground-dwelling arthropods in Patagonia, at least three pitfall traps per experimental unit are required. In addition, traps should be opened for a minimum of 10 days filled with 300 ml of 30% ethylene glycol. We also suggested the use of a simple trap design (i. e. without funnel or roof). We believe these findings will contribute to more appropriate sampling of the ground dwelling fauna of Patagonia as well as other arid areas, leading to more reliable diversity studies. PMID:21271057

  6. Transinfection: a method to investigate Wolbachia-host interactions and control arthropod-borne disease

    PubMed Central

    Hughes, Grant L.; Rasgon, Jason L.

    2014-01-01

    The bacterial endosymbiont Wolbachia manipulates arthropod host biology in numerous ways including sex ratio distortion and differential offspring survival. These bacteria infect a vast array of arthropods, some of which pose serious agricultural and human health threats. Wolbachia-mediated phenotypes such as cytoplasmic incompatibility and/or pathogen interference can be utilized for vector and disease control. However, many medically important vectors and important agricultural species are uninfected or are infected with strains of Wolbachia that do not elicit phenotypes desirable for disease or pest control. The ability to transfer strains of Wolbachia into new hosts (transinfection) can create novel Wolbachia-host associations. Transinfection has two primary benefits. First, Wolbachia-host interactions can be examined to tease apart the influence of the host and bacteria on phenotypes. Secondly, desirable phenotypes induced by Wolbachia in a particular insect can be transferred to another recipient host. This can allow for manipulation of insect populations that transmit pathogens or detrimentally affect agriculture. As such, transinfection is a valuable tool to explore Wolbachia biology and control arthropod-borne disease. This review summarizes what is currently known about Wolbachia transinfection methods and applications. We also provide a comprehensive list of published successful and unsuccessful Wolbachia transinfection attempts. PMID:24329998

  7. Pesticide-Induced Stress in Arthropod Pests for Optimized Integrated Pest Management Programs.

    PubMed

    Guedes, R N C; Smagghe, G; Stark, J D; Desneux, N

    2016-03-11

    More than six decades after the onset of wide-scale commercial use of synthetic pesticides and more than fifty years after Rachel Carson's Silent Spring, pesticides, particularly insecticides, arguably remain the most influential pest management tool around the globe. Nevertheless, pesticide use is still a controversial issue and is at the regulatory forefront in most countries. The older generation of insecticide groups has been largely replaced by a plethora of novel molecules that exhibit improved human and environmental safety profiles. However, the use of such compounds is guided by their short-term efficacy; the indirect and subtler effects on their target species, namely arthropod pest species, have been neglected. Curiously, comprehensive risk assessments have increasingly explored effects on nontarget species, contrasting with the majority of efforts focused on the target arthropod pest species. The present review mitigates this shortcoming by hierarchically exploring within an ecotoxicology framework applied to integrated pest management the myriad effects of insecticide use on arthropod pest species. PMID:26473315

  8. The diversity of reproductive parasites among arthropods: Wolbachia do not walk alone

    PubMed Central

    Duron, Olivier; Bouchon, Didier; Boutin, Sébastien; Bellamy, Lawrence; Zhou, Liqin; Engelstädter, Jan; Hurst, Gregory D

    2008-01-01

    Background Inherited bacteria have come to be recognised as important components of arthropod biology. In addition to mutualistic symbioses, a range of other inherited bacteria are known to act either as reproductive parasites or as secondary symbionts. Whilst the incidence of the α-proteobacterium Wolbachia is relatively well established, the current knowledge of other inherited bacteria is much weaker. Here, we tested 136 arthropod species for a range of inherited bacteria known to demonstrate reproductive parasitism, sampling each species more intensively than in past surveys. Results The inclusion of inherited bacteria other than Wolbachia increased the number of infections recorded in our sample from 33 to 57, and the proportion of species infected from 22.8% to 32.4%. Thus, whilst Wolbachia remained the dominant inherited bacterium, it alone was responsible for around half of all inherited infections of the bacteria sampled, with members of the Cardinium, Arsenophonus and Spiroplasma ixodetis clades each occurring in 4% to 7% of all species. The observation that infection was sometimes rare within host populations, and that there was variation in presence of symbionts between populations indicates that our survey will itself underscore incidence. Conclusion This extensive survey demonstrates that at least a third of arthropod species are infected by a diverse assemblage of maternally inherited bacteria that are likely to strongly influence their hosts' biology, and indicates an urgent need to establish the nature of the interaction between non-Wolbachia bacteria and their hosts. PMID:18577218

  9. Dating the arthropod tree based on large-scale transcriptome data.

    PubMed

    Rehm, Peter; Borner, Janus; Meusemann, Karen; von Reumont, Björn M; Simon, Sabrina; Hadrys, Heike; Misof, Bernhard; Burmester, Thorsten

    2011-12-01

    Molecular sequences do not only allow the reconstruction of phylogenetic relationships among species, but also provide information on the approximate divergence times. Whereas the fossil record dates the origin of most multicellular animal phyla during the Cambrian explosion less than 540 million years ago(mya), molecular clock calculations usually suggest much older dates. Here we used a large multiple sequence alignment derived from Expressed Sequence Tags and genomes comprising 129genes (37,476 amino acid positions) and 117 taxa, including 101 arthropods. We obtained consistent divergence time estimates applying relaxed Bayesian clock models with different priors and multiple calibration points. While the influence of substitution rates, missing data, and model priors were negligible, the clock model had significant effect. A log-normal autocorrelated model was selected on basis of cross-validation. We calculated that arthropods emerged ~600 mya. Onychophorans (velvet worms) and euarthropods split ~590 mya, Pancrustacea and Myriochelata ~560 mya, Myriapoda and Chelicerata ~555 mya, and 'Crustacea' and Hexapoda ~510 mya. Endopterygote insects appeared ~390 mya. These dates are considerably younger than most previous molecular clock estimates and in better agreement with the fossil record. Nevertheless, a Precambrian origin of arthropods and other metazoan phyla is still supported. Our results also demonstrate the applicability of large datasets of random nuclear sequences for approximating the timing of multicellular animal evolution. PMID:21945788

  10. Fungal metabolic plasticity and sexual development mediate induced resistance to arthropod fungivory.

    PubMed

    Döll, Katharina; Chatterjee, Subhankar; Scheu, Stefan; Karlovsky, Petr; Rohlfs, Marko

    2013-11-22

    Prey organisms do not tolerate predator attack passively but react with a multitude of inducible defensive strategies. Although inducible defence strategies are well known in plants attacked by herbivorous insects, induced resistance of fungi against fungivorous animals is largely unknown. Resistance to fungivory is thought to be mediated by chemical properties of fungal tissue, i.e. by production of toxic secondary metabolites. However, whether fungi change their secondary metabolite composition to increase resistance against arthropod fungivory is unknown. We demonstrate that grazing by a soil arthropod, Folsomia candida, on the filamentous fungus Aspergillus nidulans induces a phenotype that repels future fungivores and retards fungivore growth. Arthropod-exposed colonies produced significantly higher amounts of toxic secondary metabolites and invested more in sexual reproduction relative to unchallenged fungi. Compared with vegetative tissue and asexual conidiospores, sexual fruiting bodies turned out to be highly resistant against fungivory in facultative sexual A. nidulans. This indicates that fungivore grazing triggers co-regulated allocation of resources to sexual reproduction and chemical defence in A. nidulans. Plastic investment in facultative sex and chemical defence may have evolved as a fungal strategy to escape from predation. PMID:24068353

  11. Structure and development of onychophoran eyes: what is the ancestral visual organ in arthropods?

    PubMed

    Mayer, Georg

    2006-12-01

    Scarce and controversial information on visual organs and their innervation in Onychophora currently do not allow a thorough comparison with Euarthropoda. Therefore, this study sets out to provide additional data on the architecture and morphogenesis of the onychophoran visual system and to explore similarities and differences between the visual organs of onychophorans and other arthropods. Based on the new data for Epiperipatus biolleyi (Peripatidae) and Metaperipatus blainvillei (Peripatopsidae), it is suggested that the compound eyes represent an autapomorphy of Euarthropoda since similarities with the onychophoran eyes are weak or absent. Instead, the innervation from a central rather than lateral part of the brain, the presence of only one (paired or unpaired) visual center, and a similar ontogenetic origin from an ectodermal groove rather than a proliferation zone suggest homology between the onychophoran eyes and the median ocelli of euarthropods. In conclusion, I suggest that the last common ancestor of arthropods bore only one pair of ocellus-like visual organs that were modified in several arthropod lineages. This hypothesis is supported by recent paleontological data. PMID:18089073

  12. Importance of terrestrial arthropods as subsidies in lowland Neotropical rain forest stream ecosystems

    USGS Publications Warehouse

    Small, Gaston E.; Torres, Pedro J.; Schwizer, Lauren M.; Duff, John H.; Pringle, Catherine M.

    2013-01-01

    The importance of terrestrial arthropods has been documented in temperate stream ecosystems, but little is known about the magnitude of these inputs in tropical streams. Terrestrial arthropods falling from the canopy of tropical forests may be an important subsidy to tropical stream food webs and could also represent an important flux of nitrogen (N) and phosphorus (P) in nutrient-poor headwater streams. We quantified input rates of terrestrial insects in eight streams draining lowland tropical wet forest in Costa Rica. In two focal headwater streams, we also measured capture efficiency by the fish assemblage and quantified terrestrially derived N- and P-excretion relative to stream nutrient uptake rates. Average input rates of terrestrial insects ranged from 5 to 41 mg dry mass/m2/d, exceeding previous measurements of aquatic invertebrate secondary production in these study streams, and were relatively consistent year-round, in contrast to values reported in temperate streams. Terrestrial insects accounted for half of the diet of the dominant fish species, Priapicthys annectens. Although terrestrially derived fish excretion was found to be a small flux relative to measured nutrient uptake rates in the focal streams, the efficient capture and processing of terrestrial arthropods by fish made these nutrients available to the local stream ecosystem. This aquatic-terrestrial linkage is likely being decoupled by deforestation in many tropical regions, with largely unknown but potentially important ecological consequences.

  13. A novel approach to the measurement of surfactant parameters in arthropod digestive juices.

    PubMed

    Romih, Tea; Kogej, Ksenija; Drobne, Damjana

    2016-05-01

    In arthropods, the determination of two important parameters of digestive juices, i.e. the total surfactant concentration and the critical micelle concentration (CMC), is challenging due to small sample volumes and low surfactant concentrations. In this work, we report a successful implementation of potentiometric titrations using the surfactant ion-selective electrode (SISE) and the pyrene fluorescence method (PFM) for the determination of the total surfactant concentration and CMC in the digestive juice of terrestrial isopod crustaceans Porcellio scaber. Pooled digestive juice extracts of four (SISE) or two (PFM) animals were used per measurement run. In both cases, digestive juice extracts in 100μL of deionized water were sufficient for one measurement run. The total surfactant concentration of P. scaber digestive juice was determined to be 9.2±3.5mM and the CMC was approximately 90μM. Our work presents an important improvement towards easy CMC determination in small volume samples in comparison with the commonly used stalagmometric technique, where much larger sample volumes are usually needed. To date, the total surfactant concentration was not measured in the digestive juices of arthropods other than Homarus vulgaris, Astacus leptodactylus and Cancer pagurus, for which complex separation and analytical techniques were required. Our results obtained by SISE and PFM therefore present the first successful quantification of surfactants and their CMC in small volumes of arthropod digestive juice without prior separation or purification techniques. PMID:26969560

  14. Control of multiple arthropod vector infestations with subolesin/akirin vaccines.

    PubMed

    Moreno-Cid, Juan A; Pérez de la Lastra, José M; Villar, Margarita; Jiménez, Maribel; Pinal, Rocío; Estrada-Peña, Agustín; Molina, Ricardo; Lucientes, Javier; Gortázar, Christian; de la Fuente, José

    2013-02-01

    Diseases transmitted by arthropod vectors such as mosquitoes, ticks and sand flies greatly impact human and animal health and thus their control is important for the eradication of vector-borne diseases (VBD). Vaccination is an environmentally friendly alternative for vector control that allows control of several VBD by targeting their common vector. Recent results have suggested that subolesin/akirin (SUB/AKR) is good candidate antigens for the control of arthropod vector infestations. Here we describe the comparative effect of vaccination with SUB, AKR and Q38 and Q41 chimeras containing SUB/AKR conserved protective epitopes on tick, mosquitoes and sand flies vector mortality, molting, oviposition and/or fertility. We demonstrated that SUB vaccination had the highest efficacy (E) across all vector species (54-92%), Q41 vaccination had the highest vaccine E in mosquitoes (99%) by reducing female survival and fertility, and Q38 vaccination had the highest effect on reducing mosquito (28%) and sand fly (26%) oviposition. The effect of vaccination on different developmental processes in several important arthropod vectors encourages the development of SUB/AKR universal vaccines for the control of multiple vector infestations and reduction of VBD. PMID:23291476

  15. Subolesin/Akirin vaccines for the control of arthropod vectors and vectorborne pathogens.

    PubMed

    de la Fuente, J; Moreno-Cid, J A; Galindo, R C; Almazan, C; Kocan, K M; Merino, O; Perez de la Lastra, J M; Estrada-Peña, A; Blouin, E F

    2013-11-01

    Diseases transmitted by arthropod vectors such as mosquitoes, ticks and sand flies greatly impact human and animal health, and therefore, their control is important for the eradication of vectorborne diseases (VBD). Vaccination is an environmentally friendly alternative for vector control that allows control of several VBD by targeting their common vector. Recent results have suggested that subolesin (SUB) and its orthologue in insects, akirin (AKR) are good candidate antigens for the control of arthropod vector infestations and pathogen infection. SUB was discovered as a tick-protective antigen in Ixodes scapularis. Vaccination trials with recombinant SUB/AKR demonstrated effective control of arthropod vector infestations in various hard and soft tick species, mosquitoes, sand flies, poultry red mites and sea lice by reducing their numbers, weight, oviposition, fertility and/or moulting. SUB/AKR vaccination also reduced tick infection with tickborne pathogens, Anaplasma phagocytophilum, A. marginale, Babesia bigemina and Borrelia burgdorferi. The effect of vaccination on different hosts, vector species, developmental stages and vectorborne pathogen infections demonstrated the feasibility of SUB/AKR universal vaccines for the control of multiple vector infestations and for reduction in VBD. PMID:24589118

  16. Effects of land management strategies on the dispersal pattern of a beneficial arthropod.

    PubMed

    Marchi, Chiara; Andersen, Liselotte Wesley; Loeschcke, Volker

    2013-01-01

    Several arthropods are known to be highly beneficial to agricultural production. Consequently it is of great relevance to study the importance of land management and land composition for the conservation of beneficial aphid-predator arthropod species in agricultural areas. Therefore our study focusing on the beneficial arthropod Bembidion lampros had two main purposes: I) identifying the physical barriers to the species' dispersal in the agricultural landscape, and II) assessing the effect of different land management strategies (i.e. use of pesticides and intensiveness) on the dispersal patterns. The study was conducted using genetic analysis (microsatellite markers) applied to samples from two agricultural areas (in Denmark) with different agricultural intensity. Land management effects on dispersal patterns were investigated with particular focus on: physical barriers, use of pesticide and intensity of cultivation. The results showed that Bembidion lampros disperse preferably through hedges rather than fields, which act as physical barriers to gene flow. Moreover the results support the hypothesis that organic fields act as reservoirs for the re-colonization of conventional fields, but only when cultivation intensity is low. These results show the importance of non-cultivated areas and of low intensity organic managed areas within the agricultural landscape as corridors for dispersal (also for a species typically found within fields). Hence, the hypothesis that pesticide use cannot be used as the sole predictor of agriculture's effect on wild species is supported as land structure and agricultural intensity can be just as important. PMID:23776633

  17. Genetic and Ontogenetic Variation in an Endangered Tree Structures Dependent Arthropod and Fungal Communities

    PubMed Central

    Gosney, Benjamin J.; O′Reilly-Wapstra, Julianne M.; Forster, Lynne G.; Barbour, Robert C.; Iason, Glenn R.; Potts, Brad M.

    2014-01-01

    Plant genetic and ontogenetic variation can significantly impact dependent fungal and arthropod communities. However, little is known of the relative importance of these extended genetic and ontogenetic effects within a species. Using a common garden trial, we compared the dependent arthropod and fungal community on 222 progeny from two highly differentiated populations of the endangered heteroblastic tree species, Eucalyptus morrisbyi. We assessed arthropod and fungal communities on both juvenile and adult foliage. The community variation was related to previous levels of marsupial browsing, as well as the variation in the physicochemical properties of leaves using near-infrared spectroscopy. We found highly significant differences in community composition, abundance and diversity parameters between eucalypt source populations in the common garden, and these were comparable to differences between the distinctive juvenile and adult foliage. The physicochemical properties assessed accounted for a significant percentage of the community variation but did not explain fully the community differences between populations and foliage types. Similarly, while differences in population susceptibility to a major marsupial herbivore may result in diffuse genetic effects on the dependent community, this still did not account for the large genetic-based differences in dependent communities between populations. Our results emphasize the importance of maintaining the populations of this rare species as separate management units, as not only are the populations highly genetically structured, this variation may alter the trajectory of biotic colonization of conservation plantings. PMID:25469641

  18. Genetic and ontogenetic variation in an endangered tree structures dependent arthropod and fungal communities.

    PubMed

    Gosney, Benjamin J; O Reilly-Wapstra, Julianne M; Forster, Lynne G; Barbour, Robert C; Iason, Glenn R; Potts, Brad M

    2014-01-01

    Plant genetic and ontogenetic variation can significantly impact dependent fungal and arthropod communities. However, little is known of the relative importance of these extended genetic and ontogenetic effects within a species. Using a common garden trial, we compared the dependent arthropod and fungal community on 222 progeny from two highly differentiated populations of the endangered heteroblastic tree species, Eucalyptus morrisbyi. We assessed arthropod and fungal communities on both juvenile and adult foliage. The community variation was related to previous levels of marsupial browsing, as well as the variation in the physicochemical properties of leaves using near-infrared spectroscopy. We found highly significant differences in community composition, abundance and diversity parameters between eucalypt source populations in the common garden, and these were comparable to differences between the distinctive juvenile and adult foliage. The physicochemical properties assessed accounted for a significant percentage of the community variation but did not explain fully the community differences between populations and foliage types. Similarly, while differences in population susceptibility to a major marsupial herbivore may result in diffuse genetic effects on the dependent community, this still did not account for the large genetic-based differences in dependent communities between populations. Our results emphasize the importance of maintaining the populations of this rare species as separate management units, as not only are the populations highly genetically structured, this variation may alter the trajectory of biotic colonization of conservation plantings. PMID:25469641

  19. Phase and speed synchronization control of four eccentric rotors driven by induction motors in a linear vibratory feeder with unknown time-varying load torques using adaptive sliding mode control algorithm

    NASA Astrophysics Data System (ADS)

    Kong, Xiangxi; Zhang, Xueliang; Chen, Xiaozhe; Wen, Bangchun; Wang, Bo

    2016-05-01

    In this paper, phase and speed synchronization control of four eccentric rotors (ERs) driven by induction motors in a linear vibratory feeder with unknown time-varying load torques is studied. Firstly, the electromechanical coupling model of the linear vibratory feeder is established by associating induction motor's model with the dynamic model of the system, which is a typical under actuated model. According to the characteristics of the linear vibratory feeder, the complex control problem of the under actuated electromechanical coupling model converts to phase and speed synchronization control of four ERs. In order to keep the four ERs operating synchronously with zero phase differences, phase and speed synchronization controllers are designed by employing adaptive sliding mode control (ASMC) algorithm via a modified master-slave structure. The stability of the controllers is proved by Lyapunov stability theorem. The proposed controllers are verified by simulation via Matlab/Simulink program and compared with the conventional sliding mode control (SMC) algorithm. The results show the proposed controllers can reject the time-varying load torques effectively and four ERs can operate synchronously with zero phase differences. Moreover, the control performance is better than the conventional SMC algorithm and the chattering phenomenon is attenuated. Furthermore, the effects of reference speed and parametric perturbations are discussed to show the strong robustness of the proposed controllers. Finally, experiments on a simple vibratory test bench are operated by using the proposed controllers and without control, respectively, to validate the effectiveness of the proposed controllers further.

  20. Oxygen as a Driver of Early Arthropod Micro-Benthos Evolution

    PubMed Central

    Williams, Mark; Vannier, Jean; Corbari, Laure; Massabuau, Jean-Charles

    2011-01-01

    Background We examine the physiological and lifestyle adaptations which facilitated the emergence of ostracods as the numerically dominant Phanerozoic bivalve arthropod micro-benthos. Methodology/Principal Findings The PO2 of modern normoxic seawater is 21 kPa (air-equilibrated water), a level that would cause cellular damage if found in the tissues of ostracods and much other marine fauna. The PO2 of most aquatic breathers at the cellular level is much lower, between 1 and 3 kPa. Ostracods avoid oxygen toxicity by migrating to waters which are hypoxic, or by developing metabolisms which generate high consumption of O2. Interrogation of the Cambrian record of bivalve arthropod micro-benthos suggests a strong control on ecosystem evolution exerted by changing seawater O2 levels. The PO2 of air-equilibrated Cambrian-seawater is predicted to have varied between 10 and 30 kPa. Three groups of marine shelf-dwelling bivalve arthropods adopted different responses to Cambrian seawater O2. Bradoriida evolved cardiovascular systems that favoured colonization of oxygenated marine waters. Their biodiversity declined during intervals associated with black shale deposition and marine shelf anoxia and their diversity may also have been curtailed by elevated late Cambrian (Furongian) oxygen-levels that increased the PO2 gradient between seawater and bradoriid tissues. Phosphatocopida responded to Cambrian anoxia differently, reaching their peak during widespread seabed dysoxia of the SPICE event. They lacked a cardiovascular system and appear to have been adapted to seawater hypoxia. As latest Cambrian marine shelf waters became well oxygenated, phosphatocopids went extinct. Changing seawater oxygen-levels and the demise of much of the seabed bradoriid micro-benthos favoured a third group of arthropod micro-benthos, the ostracods. These animals adopted lifestyles that made them tolerant of changes in seawater O2. Ostracods became the numerically dominant arthropod micro-benthos of

  1. Seasonal abundance of soil arthropods in relation to meteorological and edaphic factors in the agroecosystems of Faisalabad, Punjab, Pakistan.

    PubMed

    Shakir, Muhammad Mussadiq; Ahmed, Sohail

    2015-05-01

    Soil arthropods are an important component of agroecosystems, contributing significantly to their biodiversity and functioning. However, seasonal patterns, population dynamics, and significant roles of these soil arthropods in improvement of soil structures and functions are influenced by many factors. The objective of the current study was to investigate soil arthropod abundance in relation to a blend of meteorological and edaphic factors and to find out the difference in abundance among various crops (sugarcane, cotton, wheat, alfalfa fodder, and citrus orchards). The arthropod sampling was done by pitfall traps and Tullgren extractions on fortnightly intervals. Soil temperature and relative humidity were noted on the field sites while analysis for soil pH, organic matter, and soil moisture contents were done in the laboratory. The rainfall data was obtained from an observatory. Results showed that significant differences were found in soil arthropod abundance across different sampling months and crops. Out of total 13,673 soil arthropods sampled, 38 % belonged to Collembola, followed by 15 % Hymenoptera, 15 % Acarina, 11 % Myriapods, 6 % Coleoptera, 5 % Orthoptera, and 5 % Araneae. Mean abundance per sample was highest in summer months as compared to winter. Overall abundance per sample was significantly different between all crops (p < 0.05). Cluster analysis revealed four categories of soil arthropods according to abundance, i.e., highly abundant (Collembola, Acarina, Myripoda, Hymenoptera), moderately abundant (Orthoptera, Aranae, Coleoptera), least abundant (Dermaptera, Hemiptera, Diptera), and rare (Blattaria, Isoptera, Diplura, Lepidoptera). Soil temperature and soil organic matter showed significant positive correlation with abundance, while relative humidity was significantly negatively correlated. Soil moisture and soil pH showed no significant correlations while no correlation was found with total rainfall. PCA analysis revealed that soil surface

  2. Seasonal abundance of soil arthropods in relation to meteorological and edaphic factors in the agroecosystems of Faisalabad, Punjab, Pakistan

    NASA Astrophysics Data System (ADS)

    Shakir, Muhammad Mussadiq; Ahmed, Sohail

    2015-05-01

    Soil arthropods are an important component of agroecosystems, contributing significantly to their biodiversity and functioning. However, seasonal patterns, population dynamics, and significant roles of these soil arthropods in improvement of soil structures and functions are influenced by many factors. The objective of the current study was to investigate soil arthropod abundance in relation to a blend of meteorological and edaphic factors and to find out the difference in abundance among various crops (sugarcane, cotton, wheat, alfalfa fodder, and citrus orchards). The arthropod sampling was done by pitfall traps and Tullgren extractions on fortnightly intervals. Soil temperature and relative humidity were noted on the field sites while analysis for soil pH, organic matter, and soil moisture contents were done in the laboratory. The rainfall data was obtained from an observatory. Results showed that significant differences were found in soil arthropod abundance across different sampling months and crops. Out of total 13,673 soil arthropods sampled, 38 % belonged to Collembola, followed by 15 % Hymenoptera, 15 % Acarina, 11 % Myriapods, 6 % Coleoptera, 5 % Orthoptera, and 5 % Araneae. Mean abundance per sample was highest in summer months as compared to winter. Overall abundance per sample was significantly different between all crops ( p < 0.05). Cluster analysis revealed four categories of soil arthropods according to abundance, i.e., highly abundant (Collembola, Acarina, Myripoda, Hymenoptera), moderately abundant (Orthoptera, Aranae, Coleoptera), least abundant (Dermaptera, Hemiptera, Diptera), and rare (Blattaria, Isoptera, Diplura, Lepidoptera). Soil temperature and soil organic matter showed significant positive correlation with abundance, while relative humidity was significantly negatively correlated. Soil moisture and soil pH showed no significant correlations while no correlation was found with total rainfall. PCA analysis revealed that soil surface

  3. Satellite Communication.

    ERIC Educational Resources Information Center

    Technology Teacher, 1985

    1985-01-01

    Presents a discussion of communication satellites: explains the principles of satellite communication, describes examples of how governments and industries are currently applying communication satellites, analyzes issues confronting satellite communication, links mathematics and science to the study of satellite communication, and applies…

  4. Factors affecting the abundance of leaf-litter arthropods in unburned and thrice-burned seasonally-dry Amazonian forests.

    PubMed

    Silveira, Juliana M; Barlow, Jos; Louzada, Julio; Moutinho, Paulo

    2010-01-01

    Fire is frequently used as a land management tool for cattle ranching and annual crops in the Amazon. However, these maintenance fires often escape into surrounding forests, with potentially severe impacts for forest biodiversity. We examined the effect of experimental fires on leaf-litter arthropod abundance in a seasonally-dry forest in the Brazilian Amazon. The study plots (50 ha each) included a thrice-burned forest and an unburned control forest. Pitfall-trap samples were collected at 160 randomly selected points in both plots, with sampling stratified across four intra-annual replicates across the dry and wet seasons, corresponding to 6, 8, 10 and 12 months after the most recent fire. Arthropods were identified to the level of order (separating Formicidae). In order to better understand the processes that determine arthropod abundance in thrice-burned forests, we measured canopy openness, understory density and litter depth. All arthropod taxa were significantly affected by fire and season. In addition, the interactions between burn treatment and season were highly significant for all taxa but Isoptera. The burned plot was characterized by a more open canopy, lower understory density and shallower litter depth. Hierarchical partitioning revealed that canopy openness was the most important factor explaining arthropod order abundances in the thrice-burned plot, whereas all three environmental variables were significant in the unburned control plot. These results reveal the marked impact of recurrent wildfires and seasonality on litter arthropods in this transitional forest, and demonstrate the overwhelming importance of canopy-openness in driving post-fire arthropod abundance. PMID:20877720

  5. Factors Affecting the Abundance of Leaf-Litter Arthropods in Unburned and Thrice-Burned Seasonally-Dry Amazonian Forests

    PubMed Central

    Silveira, Juliana M.; Barlow, Jos; Louzada, Julio; Moutinho, Paulo

    2010-01-01

    Fire is frequently used as a land management tool for cattle ranching and annual crops in the Amazon. However, these maintenance fires often escape into surrounding forests, with potentially severe impacts for forest biodiversity. We examined the effect of experimental fires on leaf-litter arthropod abundance in a seasonally-dry forest in the Brazilian Amazon. The study plots (50 ha each) included a thrice-burned forest and an unburned control forest. Pitfall-trap samples were collected at 160 randomly selected points in both plots, with sampling stratified across four intra-annual replicates across the dry and wet seasons, corresponding to 6, 8, 10 and 12 months after the most recent fire. Arthropods were identified to the level of order (separating Formicidae). In order to better understand the processes that determine arthropod abundance in thrice-burned forests, we measured canopy openness, understory density and litter depth. All arthropod taxa were significantly affected by fire and season. In addition, the interactions between burn treatment and season were highly significant for all taxa but Isoptera. The burned plot was characterized by a more open canopy, lower understory density and shallower litter depth. Hierarchical partitioning revealed that canopy openness was the most important factor explaining arthropod order abundances in the thrice-burned plot, whereas all three environmental variables were significant in the unburned control plot. These results reveal the marked impact of recurrent wildfires and seasonality on litter arthropods in this transitional forest, and demonstrate the overwhelming importance of canopy-openness in driving post-fire arthropod abundance. PMID:20877720

  6. Arthropods associated with the crown of Mauritia flexuosa (Arecaceae) palm trees in three different environments from Brazilian Cerrado.

    PubMed

    Gurgel-Gonçalves, Rodrigo; Palma, Alexandre R T; Motta, Paulo C; Bar, Maria E; Cuba, Cesar A C

    2006-01-01

    Canopy arthropods, mainly from palm trees, are little known in the Brazilian Cerrado. In order to describe the arthropod community structure associated with the crown of Mauritia flexuosa (Arecaceae), we sampled 150 palm trees in six "veredas" of the Federal District, Brazil, in wild, rural and periurban areas in the rainy season. The arthropods within abandoned bird nests, mammal refuges, leaves and organic matter were manually collected, preserved in ethanol 70% and separated by order, family, morphospecies and feeding guilds. Stem height and diameter of the palm crowns were measured and leaves and bird nests were counted. We collected 3,862 arthropods, from 15 orders, 45 families and 135 morphospecies. The most abundant orders were Coleoptera (28.6%), Blattodea (21.8%), Collembola (11.4%) and Hemiptera (10.2%). The families Blaberidae, Entomobryidae, Reduviidae, Oniscidae, Staphylinidae, Carabidae and Formicidae, represented 82.1% of all individuals collected. The majority of morphospecies was not abundant, 71 (52.6%) were represented by less than 1 individual/tree. Coleopterans accounted for the highest number of morphospecies (43.7%) followed by Araneae (20.0%). The analysis of the arthropod feeding guilds showed prevalence of predatory/hematophagous ones (36.0%). Arthropod richness and abundance presented smaller values for periurban environment. The number of bird nests presented positive correlation with abundance and richness; this was not found when considering the measurements of the palm trees. The importance of M. flexuosa for the maintenance of the arthropod fauna of the "veredas" in Cerrado biome is discussed. PMID:18575689

  7. Analysis of the effect of crushing of strontium hexaferrite powders in a vibratory mill on the properties of magnets on their basis

    NASA Astrophysics Data System (ADS)

    Kostishin, V. G.; Andreev, V. G.; Chitanov, D. N.; Timofeev, A. V.; Adamtsov, A. Yu.; Alekseev, A. A.

    2015-08-01

    We analyze the effect of duration of dry crushing of strontium hexaferrite powders (manufactured at joint-stock corporation Olkon) in a vibratory mill on the degree of disaggregation of powders and on the properties of articles on their basis. It is shown that an increase in the vibrational frequency of the vibromill from 25 to 50 Hz with the amplitude of vibrations maintained in the limits 3-4 mm makes it possible to reduce by 5 times the crushing time ensuring complete disaggregation of powders. An increase in the impact energy of balls with increasing vibrational frequency activates the powders due to microdistortions appearing in the crystal lattice. An increase in the degree of disaggregation of powders leads to sintering and formation of a dense fine-grain microstructure ensuring an increase in the maximal energy product ( BH)max of magnets by 15-20%.

  8. Technical Work Plan For: Calculation of Waste Packave and Drip Shield Response to Vibratory Ground Motion and Revision of the Seismic Consequence Abstraction

    SciTech Connect

    M. Gross

    2006-12-08

    The overall objective of the work scope covered by this technical work plan (TWP) is to develop new damage abstractions for the seismic scenario class in total system performance assessment (TSPA). The new abstractions will be based on a new set of waste package and drip shield damage calculations in response to vibratory ground motion and fault displacement. The new damage calculations, which are collectively referred to as damage models in this TWP, are required to represent recent changes in waste form packaging and in the regulatory time frame. The new damage models also respond to comments from the Independent Validation Review Team (IVRT) postvalidation review of the draft TSPA model regarding performance of the drip shield and to an Additional Information Need (AIN) from the U.S. Nuclear Regulatory Commission (NRC).

  9. Secondary succession of arthropods and plants in the Arizona Sonoran Desert in response to transmission line construction

    SciTech Connect

    Johnson, C.D.; Beley, J.R.; Ditsworth, T.M.; Butt, S.M.

    1983-03-01

    At a site about 16 km south of Black Canyon City, Arizona, density of arthropods on an undisturbed plot after an access road was built for powerline construction was much greater than on a disturbed plot. Mites, springtails, leafhoppers, scale insects, ants and thrips were signficantly reduced on the disturbed area. Our results indicate that restoration of numbers of arthropods on the disturbed area is dependent on the total plant cover on the plot, apparently regardless of the composition of the plant species involved. It is obvious in this area that the plant communities will remain dissimilar, with the pioneering herbaceous plants on the disturbed plot dominating. Cosntruction of a powerline apparently has had little impact on the structure of the arthropod community on the disturbed area, as proportions of three trophic categories of arthropods have not been radically altered. The results of this study, when compared to other studies in the Sonoran Desert and in desert grasslands disturbed by powerline construction, indicate that lengthy secondary succession does occur in the Sonoran Desert. Early arthropod invaders were found to be mainly herbivores, with few parasites or predators, and an equilibrium was eventually reached between colonizers and space requirements.

  10. Equine grazing in managed subalpine wetlands: effects on arthropods and plant structure as a function of habitat.

    PubMed

    Holmquist, Jeffrey G; Schmidt-Gengenbach, Jutta; Haultain, Sylvia A

    2013-12-01

    Grazing management necessarily emphasizes the most spatially extensive vegetation assemblages, but landscapes are mosaics, often with more mesic vegetation types embedded within a matrix of drier vegetation. Our primary objective was to contrast effects of equine grazing on both subalpine vegetation structure and associated arthropods in a drier reed grass (Calamagrostis muiriana) dominated habitat versus a wetter, more productive sedge habitat (Carex utriculata). A second objective was to compare reed grass and sedge as habitats for fauna, irrespective of grazing. All work was done in Sequoia National Park (CA, USA), where detailed, long-term records of stock management were available. We sampled paired grazed and control wet meadows that contained both habitats. There were moderate negative effects of grazing on vegetation, and effects were greater in sedge than in reed grass. Conversely, negative grazing effects on arthropods, albeit limited, were greater in the drier reed grass, possibly due to microhabitat differences. The differing effects on plants and animals as a function of habitat emphasize the importance of considering both flora and fauna, as well as multiple habitat types, when making management decisions. Sedge supported twice the overall arthropod abundance of reed grass as well as greater diversity; hemipteran and dipteran taxa were particularly abundant in sedge. Given the greater grazing effects on sedge vegetation, greater habitat provision for terrestrial arthropods, and value as aquatic arthropod habitat, the wetter sedge assemblage is worthy of additional consideration by managers when planning for grazing and other aspects of land usage. PMID:24000111

  11. Equine Grazing in Managed Subalpine Wetlands: Effects on Arthropods and Plant Structure as a Function of Habitat

    NASA Astrophysics Data System (ADS)

    Holmquist, Jeffrey G.; Schmidt-Gengenbach, Jutta; Haultain, Sylvia A.

    2013-12-01

    Grazing management necessarily emphasizes the most spatially extensive vegetation assemblages, but landscapes are mosaics, often with more mesic vegetation types embedded within a matrix of drier vegetation. Our primary objective was to contrast effects of equine grazing on both subalpine vegetation structure and associated arthropods in a drier reed grass ( Calamagrostis muiriana) dominated habitat versus a wetter, more productive sedge habitat ( Carex utriculata). A second objective was to compare reed grass and sedge as habitats for fauna, irrespective of grazing. All work was done in Sequoia National Park (CA, USA), where detailed, long-term records of stock management were available. We sampled paired grazed and control wet meadows that contained both habitats. There were moderate negative effects of grazing on vegetation, and effects were greater in sedge than in reed grass. Conversely, negative grazing effects on arthropods, albeit limited, were greater in the drier reed grass, possibly due to microhabitat differences. The differing effects on plants and animals as a function of habitat emphasize the importance of considering both flora and fauna, as well as multiple habitat types, when making management decisions. Sedge supported twice the overall arthropod abundance of reed grass as well as greater diversity; hemipteran and dipteran taxa were particularly abundant in sedge. Given the greater grazing effects on sedge vegetation, greater habitat provision for terrestrial arthropods, and value as aquatic arthropod habitat, the wetter sedge assemblage is worthy of additional consideration by managers when planning for grazing and other aspects of land usage.

  12. New approaches narrow global species estimates for beetles, insects, and terrestrial arthropods

    PubMed Central

    Stork, Nigel E.; McBroom, James; Gely, Claire; Hamilton, Andrew J.

    2015-01-01

    It has been suggested that we do not know within an order of magnitude the number of all species on Earth [May RM (1988) Science 241(4872):1441–1449]. Roughly 1.5 million valid species of all organisms have been named and described [Costello MJ, Wilson S, Houlding B (2012) Syst Biol 61(5):871–883]. Given Kingdom Animalia numerically dominates this list and virtually all terrestrial vertebrates have been described, the question of how many terrestrial species exist is all but reduced to one of how many arthropod species there are. With beetles alone accounting for about 40% of all described arthropod species, the truly pertinent question is how many beetle species exist. Here we present four new and independent estimates of beetle species richness, which produce a mean estimate of 1.5 million beetle species. We argue that the surprisingly narrow range (0.9–2.1 million) of these four autonomous estimates—derived from host-specificity relationships, ratios with other taxa, plant:beetle ratios, and a completely novel body-size approach—represents a major advance in honing in on the richness of this most significant taxon, and is thus of considerable importance to the debate on how many species exist. Using analogous approaches, we also produce independent estimates for all insects, mean: 5.5 million species (range 2.6–7.8 million), and for terrestrial arthropods, mean: 6.8 million species (range 5.9–7.8 million), which suggest that estimates for the world’s insects and their relatives are narrowing considerably. PMID:26034274

  13. New approaches narrow global species estimates for beetles, insects, and terrestrial arthropods.

    PubMed

    Stork, Nigel E; McBroom, James; Gely, Claire; Hamilton, Andrew J

    2015-06-16

    It has been suggested that we do not know within an order of magnitude the number of all species on Earth [May RM (1988) Science 241(4872):1441-1449]. Roughly 1.5 million valid species of all organisms have been named and described [Costello MJ, Wilson S, Houlding B (2012) Syst Biol 61(5):871-883]. Given Kingdom Animalia numerically dominates this list and virtually all terrestrial vertebrates have been described, the question of how many terrestrial species exist is all but reduced to one of how many arthropod species there are. With beetles alone accounting for about 40% of all described arthropod species, the truly pertinent question is how many beetle species exist. Here we present four new and independent estimates of beetle species richness, which produce a mean estimate of 1.5 million beetle species. We argue that the surprisingly narrow range (0.9-2.1 million) of these four autonomous estimates--derived from host-specificity relationships, ratios with other taxa, plant:beetle ratios, and a completely novel body-size approach--represents a major advance in honing in on the richness of this most significant taxon, and is thus of considerable importance to the debate on how many species exist. Using analogous approaches, we also produce independent estimates for all insects, mean: 5.5 million species (range 2.6-7.8 million), and for terrestrial arthropods, mean: 6.8 million species (range 5.9-7.8 million), which suggest that estimates for the world's insects and their relatives are narrowing considerably. PMID:26034274

  14. Meter scale variation in shrub dominance and soil moisture structure Arctic arthropod communities

    PubMed Central

    Hansen, Oskar Liset Pryds; Bowden, Joseph J.; Treier, Urs A.; Normand, Signe; Høye, Toke

    2016-01-01

    The Arctic is warming at twice the rate of the rest of the world. This impacts Arctic species both directly, through increased temperatures, and indirectly, through structural changes in their habitats. Species are expected to exhibit idiosyncratic responses to structural change, which calls for detailed investigations at the species and community level. Here, we investigate how arthropod assemblages of spiders and beetles respond to variation in habitat structure at small spatial scales. We sampled transitions in shrub dominance and soil moisture between three different habitats (fen, dwarf shrub heath, and tall shrub tundra) at three different sites along a fjord gradient in southwest Greenland, using yellow pitfall cups. We identified 2,547 individuals belonging to 47 species. We used species richness estimation, indicator species analysis and latent variable modeling to examine differences in arthropod community structure in response to habitat variation at local (within site) and regional scales (between sites). We estimated species responses to the environment by fitting species-specific generalized linear models with environmental covariates. Species assemblages were segregated at the habitat and site level. Each habitat hosted significant indicator species, and species richness and diversity were significantly lower in fen habitats. Assemblage patterns were significantly linked to changes in soil moisture and vegetation height, as well as geographic location. We show that meter-scale variation among habitats affects arthropod community structure, supporting the notion that the Arctic tundra is a heterogeneous environment. To gain sufficient insight into temporal biodiversity change, we require studies of species distributions detailing species habitat preferences. PMID:27478709

  15. Mercury Concentration in the Tissue of Terrestrial Arthropods from the Central California Coast

    NASA Astrophysics Data System (ADS)

    Ortiz, C.; Weiss-Penzias, P. S.; Flegal, A. R.

    2012-12-01

    The primary goal of this project was to obtain a baseline understanding and investigate the concentration of mercury (Hg) in the tissue of arthropods in coastal California. This region receives significant input of fog which may contain enhanced levels of Hg. Currently there is a lack of data on Hg concentration in the tissue of arthropods (Insecta, Malacostraca, and Arachnida). The sample collection sites were Elkhorn Slough Estuarine Reserve in Moss Landing, and the University of California Santa Cruz (UCSC) campus. Samples collected between February and March, 2012 had total Hg (HgT) concentrations in dry weight that ranged from 27 - 39 ng/g in the Jerusalem cricket (Orthoptera Stenopelmatidae); 80 - 110 ng/g in the camel cricket (Orthoptera Rhaphidophoridae); 21 - 219 ng/g in the ground beetle (Coleoptera Carabidae); 100 - 228 ng/g in the pill bug (Isopoda Armadillidiidae); and 285 - 423 ng/g in the wolf spider (Araneae Lycosidae). Monomethyl mercury (MMHg) concentrations in dry weight were determine to be 4.3 -28.2 ng/g for the ground beetle; 45.5 - 87.8 ng/g for the pill bug, and 252.3 - 293.7 ng/g for the wolf spider. Samples collected in July, 2012 had HgT concentrations in dry weight that ranged from 110 - 168 ng/g in the camel cricket; 337 - 562 ng/g in the ground beetle; 25 - 227 ng/g in the pill bug; and 228 - 501 ng/g in the wolf spider. The preliminary data revealed an 18% increase in the concentration of HgT for wolf spiders, and a 146% increase for ground beetles in the summer when compared to those concentrations measured in the spring. It is hypothesized that coastal fog may be a contributor to this increase of Hg concentration in coastal California arthropods.

  16. 'Candidatus Arthromitus' revised: segmented filamentous bacteria in arthropod guts are members of Lachnospiraceae.

    PubMed

    Thompson, Claire L; Vier, Rahel; Mikaelyan, Aram; Wienemann, Tobias; Brune, Andreas

    2012-06-01

    The name Arthromitus has been applied collectively to conspicuous filamentous bacteria found in the hindguts of termites and other arthropods. First observed by Joseph Leidy in 1849, the identity of these filaments has remained contentious. While Margulis and colleagues declared them to be a life stage of Bacillus cereus, others have assumed them to belong to the same lineage as the segmented filamentous bacteria (SFB) from vertebrate guts, a group that has garnered much attention due to their unique ability to specifically modulate their host's immune response. Both SFB and Arthromitus filaments from arthropod guts were grouped under provisional name 'Candidatus Arthromitus' by Snel and colleagues as they share a striking similarity in terms of their morphology and close contact to the host gut wall. While SFB form a distinct lineage within the family Clostridiaceae, the identity of the filaments from arthropod guts remains elusive. Using whole-genome amplification of single filaments capillary picked from termite guts and fluorescence in situ hybridization of 16S rRNA with group-specific oligonucleotide probes, we show that they represent a monophyletic lineage within the family Lachnospiraceae distinct from that of SFB. Therefore, 'Candidatus Arthromitus' can no longer be used for both groups. Given the historic precedence, we propose to reserve this name for the filaments that were originally described by Leidy. For the SFB from vertebrate guts, we propose the provisional name 'Candidatus Savagella' in honour of the American gut microbiologist Dwayne C. Savage, who was the first to describe that important bacterial group. PMID:22436008

  17. Resource-Mediated Indirect Effects of Grassland Management on Arthropod Diversity

    PubMed Central

    Simons, Nadja K.; Gossner, Martin M.; Lewinsohn, Thomas M.; Boch, Steffen; Lange, Markus; Müller, Jörg; Pašalić, Esther; Socher, Stephanie A.; Türke, Manfred; Fischer, Markus; Weisser, Wolfgang W.

    2014-01-01

    Intensive land use is a driving force for biodiversity decline in many ecosystems. In semi-natural grasslands, land-use activities such as mowing, grazing and fertilization affect the diversity of plants and arthropods, but the combined effects of different drivers and the chain of effects are largely unknown. In this study we used structural equation modelling to analyse how the arthropod communities in managed grasslands respond to land use and whether these responses are mediated through changes in resource diversity or resource quantity (biomass). Plants were considered resources for herbivores which themselves were considered resources for predators. Plant and arthropod (herbivores and predators) communities were sampled on 141 meadows, pastures and mown pastures within three regions in Germany in 2008 and 2009. Increasing land-use intensity generally increased plant biomass and decreased plant diversity, mainly through increasing fertilization. Herbivore diversity decreased together with plant diversity but showed no response to changes in plant biomass. Hence, land-use effects on herbivore diversity were mediated through resource diversity rather than quantity. Land-use effects on predator diversity were mediated by both herbivore diversity (resource diversity) and herbivore quantity (herbivore biomass), but indirect effects through resource quantity were stronger. Our findings highlight the importance of assessing both direct and indirect effects of land-use intensity and mode on different trophic levels. In addition to the overall effects, there were subtle differences between the different regions, pointing to the importance of regional land-use specificities. Our study underlines the commonly observed strong effect of grassland land use on biodiversity. It also highlights that mechanistic approaches help us to understand how different land-use modes affect biodiversity. PMID:25188423

  18. Biodiversity and resilience of arthropod communities after fire disturbance in temperate forests.

    PubMed

    Moretti, Marco; Duelli, Peter; Obrist, Martin K

    2006-08-01

    Changes in ecosystem functions following disturbances are of central concern in ecology and a challenge for ecologists is to understand the factors that affect the resilience of community structures and ecosystem functions. In many forest ecosystems, one such important natural disturbance is fire. The aim of this study was to understand the variation of resilience in six functional groups of invertebrates in response to different fire frequencies in southern Switzerland. We measured resilience by analysing arthropod species composition, abundance and diversity in plots where the elapsed time after single or repeated fires, as determined by dendrochronology, varied. We compared data from these plots with data from plots that had not burned recently and defined high resilience as the rapid recovery of the species composition to that prior to fire. Pooling all functional groups showed that they were more resilient to single fires than to repeated events, recovering 6-14 years after a single fire, but only 17-24 years after the last of several fires. Flying zoophagous and phytophagous arthropods were the most resilient groups. Pollinophagous and epigaeic zoophagous species showed intermediate resilience, while ground-litter saprophagous and saproxylophagous arthropods clearly displayed the lowest resilience to fire. Their species composition 17-24 years post-burn still differed markedly from that of the unburned control plots. Depending on the fire history of a forest plot, we found significant differences in the dominance hierarchy among invertebrate species. Any attempt to imitate natural disturbances, such as fire, through forest management must take into account the recovery times of biodiversity, including functional group composition, to ensure the conservation of multiple taxa and ecosystem functions in a sustainable manner. PMID:16804704

  19. The Importance of Acacia Trees for Insectivorous Bats and Arthropods in the Arava Desert

    PubMed Central

    Hackett, Talya D.; Korine, Carmi; Holderied, Marc W.

    2013-01-01

    Anthropogenic habitat modification often has a profound negative impact on the flora and fauna of an ecosystem. In parts of the Middle East, ephemeral rivers (wadis) are characterised by stands of acacia trees. Green, flourishing assemblages of these trees are in decline in several countries, most likely due to human-induced water stress and habitat changes. We examined the importance of healthy acacia stands for bats and their arthropod prey in comparison to other natural and artificial habitats available in the Arava desert of Israel. We assessed bat activity and species richness through acoustic monitoring for entire nights and concurrently collected arthropods using light and pit traps. Dense green stands of acacia trees were the most important natural desert habitat for insectivorous bats. Irrigated gardens and parks in villages and fields of date palms had high arthropod levels but only village sites rivalled acacia trees in bat activity level. We confirmed up to 13 bat species around a single patch of acacia trees; one of the richest sites in any natural desert habitat in Israel. Some bat species utilised artificial sites; others were found almost exclusively in natural habitats. Two rare species (Barbastella leucomelas and Nycteris thebaica) were identified solely around acacia trees. We provide strong evidence that acacia trees are of unique importance to the community of insectivorous desert-dwelling bats, and that the health of the trees is crucial to their value as a foraging resource. Consequently, conservation efforts for acacia habitats, and in particular for the green more densely packed stands of trees, need to increase to protect this vital habitat for an entire community of protected bats. PMID:23441145

  20. Geographic patterns in the distribution of social systems in terrestrial arthropods.

    PubMed

    Purcell, Jessica

    2011-05-01

    The role of ecology in the evolution and maintenance of arthropod sociality has received increasing research attention in recent years. In some organisms, such as halictine bees, polistine wasps, and social spiders, researchers are investigating the environmental factors that may contribute to high levels of variation in the degree of sociality exhibited both among and within species. Within lineages that include only eusocial members, such as ants and termites, studies focus more on identifying extrinsic factors that may contribute to the dramatic variation in colony size, number of queens, and division of labour that is evident across these species. In this review, I propose a comparative approach that seeks to identify environmental factors that may have a common influence across such divergent social arthropod groups. I suggest that seeking common biogeographic patterns in the distribution of social systems or key social traits may help us to identify ecological factors that play a common role in shaping the evolution of sociality across different organisms. I first review previous studies of social gradients that form along latitudinal and altitudinal axes. Within families and within species, many organisms show an increasing degree of sociality at lower latitudes and altitudes. In a smaller number of cases, organisms form larger groups or found nests cooperatively at higher latitudes and altitudes. I then describe several environmental factors that vary consistently along such gradients, including climate variables and abundance of predators, and outline their proposed role in the social systems of terrestrial arthropods. Finally, I map distributions of a social trait against several climatic factors in five case studies to demonstrate how future comparative studies could inform empirical research. PMID:20840372