Science.gov

Sample records for locust lobula giant

  1. Non-Linear Neuronal Responses as an Emergent Property of Afferent Networks: A Case Study of the Locust Lobula Giant Movement Detector

    PubMed Central

    Bermúdez i Badia, Sergi; Bernardet, Ulysses; Verschure, Paul F. M. J.

    2010-01-01

    In principle it appears advantageous for single neurons to perform non-linear operations. Indeed it has been reported that some neurons show signatures of such operations in their electrophysiological response. A particular case in point is the Lobula Giant Movement Detector (LGMD) neuron of the locust, which is reported to locally perform a functional multiplication. Given the wide ramifications of this suggestion with respect to our understanding of neuronal computations, it is essential that this interpretation of the LGMD as a local multiplication unit is thoroughly tested. Here we evaluate an alternative model that tests the hypothesis that the non-linear responses of the LGMD neuron emerge from the interactions of many neurons in the opto-motor processing structure of the locust. We show, by exposing our model to standard LGMD stimulation protocols, that the properties of the LGMD that were seen as a hallmark of local non-linear operations can be explained as emerging from the dynamics of the pre-synaptic network. Moreover, we demonstrate that these properties strongly depend on the details of the synaptic projections from the medulla to the LGMD. From these observations we deduce a number of testable predictions. To assess the real-time properties of our model we applied it to a high-speed robot. These robot results show that our model of the locust opto-motor system is able to reliably stabilize the movement trajectory of the robot and can robustly support collision avoidance. In addition, these behavioural experiments suggest that the emergent non-linear responses of the LGMD neuron enhance the system's collision detection acuity. We show how all reported properties of this neuron are consistently reproduced by this alternative model, and how they emerge from the overall opto-motor processing structure of the locust. Hence, our results propose an alternative view on neuronal computation that emphasizes the network properties as opposed to the local

  2. Anatomy of the lobula complex in the brain of the praying mantis compared to the lobula complexes of the locust and cockroach.

    PubMed

    Rosner, Ronny; von Hadeln, Joss; Salden, Tobias; Homberg, Uwe

    2017-07-01

    The praying mantis is an insect which relies on vision for capturing prey, avoiding being eaten and for spatial orientation. It is well known for its ability to use stereopsis for estimating the distance of objects. The neuronal substrate mediating visually driven behaviors, however, is not very well investigated. To provide a basis for future functional studies, we analyzed the anatomical organization of visual neuropils in the brain of the praying mantis Hierodula membranacea and provide supporting evidence from a second species, Rhombodera basalis, with particular focus on the lobula complex (LOX). Neuropils were three-dimensionally reconstructed from synapsin-immunostained whole mount brains. The neuropil organization and the pattern of γ-aminobutyric acid immunostaining of the medulla and LOX were compared between the praying mantis and two related polyneopteran species, the Madeira cockroach and the desert locust. The investigated visual neuropils of the praying mantis are highly structured. Unlike in most insects the LOX of the praying mantis consists of five nested neuropils with at least one neuropil not present in the cockroach or locust. Overall, the mantis LOX is more similar to the LOX of the locust than the more closely related cockroach suggesting that the sensory ecology plays a stronger role than the phylogenetic distance of the three species in structuring this center of visual information processing. © 2017 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.

  3. Anatomy of the lobula complex in the brain of the praying mantis compared to the lobula complexes of the locust and cockroach

    PubMed Central

    von Hadeln, Joss; Salden, Tobias; Homberg, Uwe

    2017-01-01

    Abstract The praying mantis is an insect which relies on vision for capturing prey, avoiding being eaten and for spatial orientation. It is well known for its ability to use stereopsis for estimating the distance of objects. The neuronal substrate mediating visually driven behaviors, however, is not very well investigated. To provide a basis for future functional studies, we analyzed the anatomical organization of visual neuropils in the brain of the praying mantis Hierodula membranacea and provide supporting evidence from a second species, Rhombodera basalis, with particular focus on the lobula complex (LOX). Neuropils were three‐dimensionally reconstructed from synapsin‐immunostained whole mount brains. The neuropil organization and the pattern of γ‐aminobutyric acid immunostaining of the medulla and LOX were compared between the praying mantis and two related polyneopteran species, the Madeira cockroach and the desert locust. The investigated visual neuropils of the praying mantis are highly structured. Unlike in most insects the LOX of the praying mantis consists of five nested neuropils with at least one neuropil not present in the cockroach or locust. Overall, the mantis LOX is more similar to the LOX of the locust than the more closely related cockroach suggesting that the sensory ecology plays a stronger role than the phylogenetic distance of the three species in structuring this center of visual information processing. PMID:28295329

  4. Characterization of lobula giant neurons responsive to visual stimuli that elicit escape behaviors in the crab Chasmagnathus.

    PubMed

    Medan, Violeta; Oliva, Damián; Tomsic, Daniel

    2007-10-01

    In the grapsid crab Chasmagnathus, a visual danger stimulus elicits a strong escape response that diminishes rapidly on stimulus repetition. This behavioral modification can persist for several days as a result of the formation of an associative memory. We have previously shown that a generic group of large motion-sensitive neurons from the lobula of the crab respond to visual stimuli and accurately reflect the escape performance. Additional evidence indicates that these neurons play a key role in visual memory and in the decision to initiate an escape. Although early studies recognized that the group of lobula giant (LG) neurons consisted of different classes of motion-sensitive cells, a distinction between these classes has been lacking. Here, we recorded in vivo the responses of individual LG neurons to a wide range of visual stimuli presented in different segments of the animal's visual field. Physiological characterizations were followed by intracellular dye injections, which permitted comparison of the functional and morphological features of each cell. All LG neurons consisted of large tangential arborizations in the lobula with axons projecting toward the midbrain. Functionally, these cells proved to be more sensitive to single objects than to flow field motion. Despite these commonalities, clear differences in morphology and physiology allowed us to identify four distinct classes of LG neurons. These results will permit analysis of the role of each neuronal type for visually guided behaviors and will allow us to address specific questions on the neuronal plasticity of LGs that underlie the well-recognized memory model of the crab.

  5. Looming detection by identified visual interneurons during larval development of the locust Locusta migratoria.

    PubMed

    Simmons, Peter J; Sztarker, Julieta; Rind, F Claire

    2013-06-15

    Insect larvae clearly react to visual stimuli, but the ability of any visual neuron in a newly hatched insect to respond selectively to particular stimuli has not been directly tested. We characterised a pair of neurons in locust larvae that have been extensively studied in adults, where they are known to respond selectively to objects approaching on a collision course: the lobula giant motion detector (LGMD) and its postsynaptic partner, the descending contralateral motion detector (DCMD). Our physiological recordings of DCMD axon spikes reveal that at the time of hatching, the neurons already respond selectively to objects approaching the locust and they discriminate between stimulus approach speeds with differences in spike frequency. For a particular approaching stimulus, both the number and peak frequency of spikes increase with instar. In contrast, the number of spikes in responses to receding stimuli decreases with instar, so performance in discriminating approaching from receding stimuli improves as the locust goes through successive moults. In all instars, visual movement over one part of the visual field suppresses a response to movement over another part. Electron microscopy demonstrates that the anatomical substrate for the selective response to approaching stimuli is present in all larval instars: small neuronal processes carrying information from the eye make synapses both onto LGMD dendrites and with each other, providing pathways for lateral inhibition that shape selectivity for approaching objects.

  6. A crustacean lobula plate: Morphology, connections, and retinotopic organization.

    PubMed

    Bengochea, Mercedes; Berón de Astrada, Martín; Tomsic, Daniel; Sztarker, Julieta

    2017-09-07

    The lobula plate is part of the lobula complex, the third optic neuropil, in the optic lobes of insects. It has been extensively studied in dipterous insects, where its role in processing flow-field motion information used for controlling optomotor responses was discovered early. Recently, a lobula plate was also found in malacostracan crustaceans. Here, we provide the first detailed description of the neuroarchitecture, the input and output connections and the retinotopic organization of the lobula plate in a crustacean, the crab Neohelice granulata using a variety of histological methods that include silver reduced staining and mass staining with dextran-conjugated dyes. The lobula plate of this crab is a small elongated neuropil. It receives separated retinotopic inputs from columnar neurons of the medulla and the lobula. In the anteroposterior plane, the neuropil possesses four layers defined by the arborizations of such columnar inputs. Medulla projecting neurons arborize mainly in two of these layers, one on each side, while input neurons arriving from the lobula branch only in one. The neuropil contains at least two classes of tangential elements, one connecting with the lateral protocerebrum and the other that exits the optic lobes toward the supraesophageal ganglion. The number of layers in the crab's lobula plate, the retinotopic connections received from the medulla and from the lobula, and the presence of large tangential neurons exiting the neuropil, reflect the general structure of the insect lobula plate and, hence, provide support to the notion of an evolutionary conserved function for this neuropil. © 2017 Wiley Periodicals, Inc.

  7. Two identified looming detectors in the locust: ubiquitous lateral connections among their inputs contribute to selective responses to looming objects

    PubMed Central

    Rind, F. Claire; Wernitznig, Stefan; Pölt, Peter; Zankel, Armin; Gütl, Daniel; Sztarker, Julieta; Leitinger, Gerd

    2016-01-01

    In locusts, two lobula giant movement detector neurons (LGMDs) act as looming object detectors. Their reproducible responses to looming and their ethological significance makes them models for single neuron computation. But there is no comprehensive picture of the neurons that connect directly to each LGMD. We used high-through-put serial block-face scanning-electron-microscopy to reconstruct the network of input-synapses onto the LGMDs over spatial scales ranging from single synapses and small circuits, up to dendritic branches and total excitatory input. Reconstructions reveal that many trans-medullary-afferents (TmAs) connect the eye with each LGMD, one TmA per facet per LGMD. But when a TmA synapses with an LGMD it also connects laterally with another TmA. These inter-TmA synapses are always reciprocal. Total excitatory input to the LGMD 1 and 2 comes from 131,000 and 186,000 synapses reaching densities of 3.1 and 2.6 synapses per μm2 respectively. We explored the computational consequences of reciprocal synapses between each TmA and 6 others from neighbouring columns. Since any lateral interactions between LGMD inputs have always been inhibitory we may assume these reciprocal lateral connections are most likely inhibitory. Such reciprocal inhibitory synapses increased the LGMD’s selectivity for looming over passing objects, particularly at the beginning of object approach. PMID:27774991

  8. Two identified looming detectors in the locust: ubiquitous lateral connections among their inputs contribute to selective responses to looming objects

    NASA Astrophysics Data System (ADS)

    Rind, F. Claire; Wernitznig, Stefan; Pölt, Peter; Zankel, Armin; Gütl, Daniel; Sztarker, Julieta; Leitinger, Gerd

    2016-10-01

    In locusts, two lobula giant movement detector neurons (LGMDs) act as looming object detectors. Their reproducible responses to looming and their ethological significance makes them models for single neuron computation. But there is no comprehensive picture of the neurons that connect directly to each LGMD. We used high-through-put serial block-face scanning-electron-microscopy to reconstruct the network of input-synapses onto the LGMDs over spatial scales ranging from single synapses and small circuits, up to dendritic branches and total excitatory input. Reconstructions reveal that many trans-medullary-afferents (TmAs) connect the eye with each LGMD, one TmA per facet per LGMD. But when a TmA synapses with an LGMD it also connects laterally with another TmA. These inter-TmA synapses are always reciprocal. Total excitatory input to the LGMD 1 and 2 comes from 131,000 and 186,000 synapses reaching densities of 3.1 and 2.6 synapses per μm2 respectively. We explored the computational consequences of reciprocal synapses between each TmA and 6 others from neighbouring columns. Since any lateral interactions between LGMD inputs have always been inhibitory we may assume these reciprocal lateral connections are most likely inhibitory. Such reciprocal inhibitory synapses increased the LGMD’s selectivity for looming over passing objects, particularly at the beginning of object approach.

  9. Neurobiology of polarization vision in the locust Schistocerca gregaria.

    PubMed

    Homberg, U; Hofer, Sabine; Mappes, Martina; Vitzthum, H; Pfeiffer, K; Gebhardt, S; Müller, Monika; Paech, Agnes

    2004-01-01

    The polarization pattern of the blue sky serves as an important reference for spatial orientation in insects. To understand the neural mechanisms involved in sky compass orientation we have analyzed the polarization vision system in the locust Schistocerca gregaria. As in other insects, photoreceptors adapted for the detection of sky polarization are concentrated in a dorsal rim area (DRA) of the compound eye. Stationary flying locusts show polarotactic yaw-torque responses when illuminated through a rotating polarizer from above. This response is abolished after painting the DRAs. Central stages of the polarization vision system, revealed through tracing studies, include dorsal areas in the lamina and medulla, the anterior lobe of the lobula, the anterior optic tubercle, the lateral accessory lobe and the central complex. Physiological analysis of polarization-sensitive (POL) neurons has focussed on the optic tubercle and on the central complex. Each POL neuron was maximally excited at a certain e-vector (phimax) and was maximally inhibited at an e-vector perpendicular to phimax. The neurons had large visual fields, and many neurons received input from both eyes. The neuronal organization of the central complex suggests a role as a spatial compass within the locust brain.

  10. The Locust Borer

    Treesearch

    Jimmy R. Galford

    1984-01-01

    The locust borer, Megacyllene robiniae (Forst.), is a native insect. Its original range probably coincided with that of its host tree, the black locust, which once grew only along the Allegheny Mountains from Pennsylvania to Georgia and in the Ozark Mountain region.

  11. Locusts and remote sensing: a review

    NASA Astrophysics Data System (ADS)

    Latchininsky, Alexandre V.

    2013-01-01

    A dozen species of locusts (Orthoptera: Acrididae) are a major threat to food security worldwide. Their outbreaks occur on every continent except Antarctica, threatening the livelihood of 10% of the world's population. The locusts are infamous for their voracity, polyphagy, and capacity for long-distance migrations. Decades of research revealed very complex bio-ecology of locusts. They exist in two, inter-convertible and density-dependent states, or "phases." Despite the evident progress in understanding locust behavior, our ability to predict and manage locust outbreaks remains insufficient, as evidenced by locust plagues still occurring during the 21st century. One of the main reasons is that locusts typically inhabit remote and scarcely populated areas, and their distribution ranges often spread across continents. This creates tremendous obstacles for locust population monitoring and control. Traditional ground locust surveys are inadequate to address the enormous spatial scale of the locust problem in a limited window of time dictated by the pest's development. Remote sensing (satellite information) appears a promising tool in locust monitoring. Satellite data are increasingly used for monitoring and forecasting two locust species, the desert and the Australian plague locust. However, applications of this geospatial technology to other locust species remain rare.

  12. Receptive field properties and intensity-response functions of polarization-sensitive neurons of the optic tubercle in gregarious and solitarious locusts.

    PubMed

    el Jundi, Basil; Homberg, Uwe

    2012-09-01

    Many migrating insects rely on the plane of sky polarization as a cue to detect spatial directions. Desert locusts (Schistocerca gregaria), like other insects, perceive polarized light through specialized photoreceptors in a dorsal eye region. Desert locusts occur in two phases: a gregarious swarming phase, which migrates during the day, and a solitarious nocturnal phase. Neurons in a small brain area, the anterior optic tubercle (AOTu), are critically involved in processing polarized light in the locust brain. While polarization-sensitive intertubercle cells [lobula-tubercle neuron 1 (LoTu1) and tubercle-tubercle neuron 1 (TuTu1)] interconnect the AOTu of both hemispheres, tubercle-lateral accessory lobe tract (TuLAL1) neurons transmit sky compass signals to a polarization compass in the central brain. To better understand the neural network underlying polarized light processing in the AOTu and to investigate possible adaptations of the polarization vision system to a diurnal versus nocturnal lifestyle, we analyzed receptive field properties, intensity-response relationships, and daytime dependence of responses of AOTu neurons in gregarious and solitarious locusts. Surprisingly, no differences in the physiology of these neurons were found between the two locust phases. Instead, clear differences were observed between the different types of AOTu neurons. Whereas TuTu1 and TuLAL1 neurons encoded E-vector orientation independent of light intensity and would thus be operational in bright daylight, LoTu1 neurons were inhibited by high light intensity and provided strong polarization signaling only under dim light conditions. The presence of high- and low-intensity polarization channels might, therefore, allow solitarious and gregarious locusts to use the same polarization coding system despite their different activity cycles.

  13. A stochastic lattice model for locust outbreak

    NASA Astrophysics Data System (ADS)

    Kizaki, Shinya; Katori, Makoto

    The locust is a kind of grasshoppers. Gregarious locusts form swarms and can migrate over large distances and they spread and damage a large area (locust outbreak). When the density is low, each of locusts behaves as an individual insect (solitary phase). As locusts become crowded, they become to act as a part of a group (gregarious phase) as a result of interactions among them. Modeling of this phenomenon is a challenging problem of statistical physics. We introduce a stochastic cellular automaton model of locust population-dynamics on lattices. Change of environmental conditions by seasonal migration is a key factor in gregarisation of locusts and we take it into account by changing the lattice size periodically. We study this model by computer simulations and discuss the locust outbreak as a cooperative phenomena.

  14. Neural Action Fields for Optic Flow Based Navigation: A Simulation Study of the Fly Lobula Plate Network

    PubMed Central

    Borst, Alexander; Weber, Franz

    2011-01-01

    Optic flow based navigation is a fundamental way of visual course control described in many different species including man. In the fly, an essential part of optic flow analysis is performed in the lobula plate, a retinotopic map of motion in the environment. There, the so-called lobula plate tangential cells possess large receptive fields with different preferred directions in different parts of the visual field. Previous studies demonstrated an extensive connectivity between different tangential cells, providing, in principle, the structural basis for their large and complex receptive fields. We present a network simulation of the tangential cells, comprising most of the neurons studied so far (22 on each hemisphere) with all the known connectivity between them. On their dendrite, model neurons receive input from a retinotopic array of Reichardt-type motion detectors. Model neurons exhibit receptive fields much like their natural counterparts, demonstrating that the connectivity between the lobula plate tangential cells indeed can account for their complex receptive field structure. We describe the tuning of a model neuron to particular types of ego-motion (rotation as well as translation around/along a given body axis) by its ‘action field’. As we show for model neurons of the vertical system (VS-cells), each of them displays a different type of action field, i.e., responds maximally when the fly is rotating around a particular body axis. However, the tuning width of the rotational action fields is relatively broad, comparable to the one with dendritic input only. The additional intra-lobula-plate connectivity mainly reduces their translational action field amplitude, i.e., their sensitivity to translational movements along any body axis of the fly. PMID:21305019

  15. Locust Leafminer, Odonatata dorsalis (Thunb.) (Pest Alert)

    Treesearch

    USDA Forest Service

    2001-01-01

    The locust leafminer is primarily a pest of black locust. Adults skeletonize and eat holes in the leaves; whereas, larvae mine the tissue between the upper and lower-leaf surface (mining damage is the most destructive). Under outbreak conditions, whole hillsides turn gray or brown, often suggesting fall color change. Outbreaks of the locust leafminer are generally more...

  16. Patterns of chromatic information processing in the lobula of the honeybee, Apis mellifera L.

    PubMed

    Yang, En-Cheng; Lin, Hsiao-Chun; Hung, Yu-Shan

    2004-10-01

    The honeybee, Apis mellifera L., is one of the living creatures that has its colour vision proven through behavioural tests. Previous studies of honeybee colour vision has emphasized the relationship between the spectral sensitivities of photoreceptors and colour discrimination behaviour. The current understanding of the neural mechanisms of bee colour vision is, however, rather limited. The present study surveyed the patterns of chromatic information processing of visual neurons in the lobula of the honeybee, using intracellular recording stimulated by three light-emitting diodes, whose emission spectra approximately match the spectral sensitivity peaks of the honeybee. The recorded visual neurons can be divided into two groups: non-colour opponent cells and colour opponent cells. The non-colour opponent cells comprise six types of broad-band neurons and four response types of narrow-band neurons. The former might detect brightness of the environment or function as chromatic input channels, and the latter might supply specific chromatic input. Amongst the colour opponent cells, the principal neural mechanism of colour vision, eight response types were recorded. The receptive fields of these neurons were not centre surround as observed in primates. Some recorded neurons with tonic post-stimulus responses were observed, however, suggesting temporal defined spectral opponency may be part of the colour-coding mechanisms.

  17. Visual projection neurons in the Drosophila lobula link feature detection to distinct behavioral programs

    PubMed Central

    Wu, Ming; Nern, Aljoscha; Williamson, W Ryan; Morimoto, Mai M; Reiser, Michael B; Card, Gwyneth M; Rubin, Gerald M

    2016-01-01

    Visual projection neurons (VPNs) provide an anatomical connection between early visual processing and higher brain regions. Here we characterize lobula columnar (LC) cells, a class of Drosophila VPNs that project to distinct central brain structures called optic glomeruli. We anatomically describe 22 different LC types and show that, for several types, optogenetic activation in freely moving flies evokes specific behaviors. The activation phenotypes of two LC types closely resemble natural avoidance behaviors triggered by a visual loom. In vivo two-photon calcium imaging reveals that these LC types respond to looming stimuli, while another type does not, but instead responds to the motion of a small object. Activation of LC neurons on only one side of the brain can result in attractive or aversive turning behaviors depending on the cell type. Our results indicate that LC neurons convey information on the presence and location of visual features relevant for specific behaviors. DOI: http://dx.doi.org/10.7554/eLife.21022.001 PMID:28029094

  18. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree, Ceratonia...

  19. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343... GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree, Ceratonia siliqua (Linne), a leguminous evergreen...

  20. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree, Ceratonia...

  1. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree, Ceratonia...

  2. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree, Ceratonia...

  3. Locust Collective Motion and Its Modeling

    PubMed Central

    Ariel, Gil; Ayali, Amir

    2015-01-01

    Over the past decade, technological advances in experimental and animal tracking techniques have motivated a renewed theoretical interest in animal collective motion and, in particular, locust swarming. This review offers a comprehensive biological background followed by comparative analysis of recent models of locust collective motion, in particular locust marching, their settings, and underlying assumptions. We describe a wide range of recent modeling and simulation approaches, from discrete agent-based models of self-propelled particles to continuous models of integro-differential equations, aimed at describing and analyzing the fascinating phenomenon of locust collective motion. These modeling efforts have a dual role: The first views locusts as a quintessential example of animal collective motion. As such, they aim at abstraction and coarse-graining, often utilizing the tools of statistical physics. The second, which originates from a more biological perspective, views locust swarming as a scientific problem of its own exceptional merit. The main goal should, thus, be the analysis and prediction of natural swarm dynamics. We discuss the properties of swarm dynamics using the tools of statistical physics, as well as the implications for laboratory experiments and natural swarms. Finally, we stress the importance of a combined-interdisciplinary, biological-theoretical effort in successfully confronting the challenges that locusts pose at both the theoretical and practical levels. PMID:26656851

  4. Locust bean gum: a versatile biopolymer.

    PubMed

    Prajapati, Vipul D; Jani, Girish K; Moradiya, Naresh G; Randeria, Narayan P; Nagar, Bhanu J

    2013-05-15

    Biopolymers or natural polymers are an attractive class of biodegradable polymers since they are derived from natural sources, easily available, relatively cheap and can be modified by suitable reagent. Locust bean gum is one of them that have a wide potentiality in drug formulations due to its extensive application as food additive and its recognized lack of toxicity. It can be tailored to suit its demands of applicants in both the pharmaceutical and biomedical areas. Locust bean gum has a wide application either in the field of novel drug delivery system as rate controlling excipients or in tissue engineering as scaffold formation. Through keen references of reported literature on locust bean gum, in this review, we have described critical aspects of locust bean gum, its manufacturing process, physicochemical properties and applications in various drug delivery systems.

  5. Locusts for Lunch: Connecting Mathematics, Science, and Literature

    ERIC Educational Resources Information Center

    Austin, Richard A.; Thompson, Denisse R.; Beckmann, Charlene E.

    2006-01-01

    This article connects three disciplines while exploring how students computed tons of food consumed by both locusts and people. Included with this article are two worksheets "How Much Does a Locust Eat?" and "Can You Eat Those Locusts?". (Contains 3 figures.)

  6. Bristly locust: Establishment success in an emulated organic silvopasture

    USDA-ARS?s Scientific Manuscript database

    Bristly locust (Robinia hispida) is a native tree legume found throughout much of the US, but it has received relatively little attention as a potential crop. While only 2-10 ft tall, bristly locust somewhat resembles black locust, produces pink flowers, and the stems are covered by soft, inoffensiv...

  7. Molecular mechanisms of phase change in locusts.

    PubMed

    Wang, Xianhui; Kang, Le

    2014-01-01

    Phase change in locusts is an ideal model for studying the genetic architectures and regulatory mechanisms associated with phenotypic plasticity. The recent development of genomic and metabolomic tools and resources has furthered our understanding of the molecular basis of phase change in locusts. Thousands of phase-related genes and metabolites have been highlighted using large-scale expressed sequence tags, microarrays, high-throughput transcriptomic sequences, or metabolomic approaches. However, only several key factors, including genes, metabolites, and pathways, have a critical role in phase transition in locusts. For example, CSP (chemosensory protein) and takeout genes, the dopamine pathway, protein kinase A, and carnitines were found to be involved in the regulation of behavioral phase change and gram-negative bacteria-binding proteins in prophylaxical disease resistance of gregarious locusts. Epigenetic mechanisms including small noncoding RNAs and DNA methylation have been implicated. We review these new advances in the molecular basis of phase change in locusts and present some challenges that need to be addressed.

  8. Allometry and biomass of pollarded black locust

    Treesearch

    David M. Burner; Daniel H. Pote; Adrian Ares

    2006-01-01

    Climatic constraints can cause forage deficits in the summer in west-central Arkansas, necessitating expensive, supplemental hay feeding. Black locust could be used for summer browse, but the temporal distribution of foliar biomass has not been adequately tested. Our objective was to determine effects of harvest date, fertilization (0 and 600 kg P ha-1...

  9. The Locust Jump: An Integrated Laboratory Investigation

    ERIC Educational Resources Information Center

    Scott, Jon

    2005-01-01

    The locust is well known for its ability to jump large distances to avoid predation. This class sets out a series of investigations into the mechanisms underlying the jump enabling students to bring together information from biomechanics, muscle physiology, and anatomy. The nature of the investigation allows it to be undertaken at a number of…

  10. The Locust Jump: An Integrated Laboratory Investigation

    ERIC Educational Resources Information Center

    Scott, Jon

    2005-01-01

    The locust is well known for its ability to jump large distances to avoid predation. This class sets out a series of investigations into the mechanisms underlying the jump enabling students to bring together information from biomechanics, muscle physiology, and anatomy. The nature of the investigation allows it to be undertaken at a number of…

  11. Deer prefer pine seedlings growing near black locust

    Treesearch

    Walter H. Davidson

    1970-01-01

    The presence of volunteer black locust seems to make some pine species on a bituminous coal spoil more palatable to white-tailed deer. Seedlings of jack pine, pitch pine, and Austrian pine were browsed more heavily when within 10 feet of a black locust than when farther away. The nitrogen produced by the black locust may have caused more succulent tissue in the pines....

  12. The second and third optic ganglia of the worker bee: Golgi studies of the neuronal elements in the medulla and lobula.

    PubMed

    Ribi, W A; Scheel, M

    1981-01-01

    The gross morphology and the fine-structural characteristics of neurones of the second and third optic ganglia of the honeybee Apis mellifera were investigated light microscopically on the basis of Golgi (selective silver)- and reduced silver preparations. The second optic ganglion, the medulla, is ovoid in shape and has a slightly convex distal surface and a slightly concave proximal surface. The medullar outer levels are characteristically composed of neuronal arrangements showing strict precision of their geometrical spacing proximally as far as a pronounced layer of tangential fibre elements comprising the serpentine layer of the medulla. At the inner medullary levels retinotopic channels are again multiplied, and the arrangement of axons and dendrites contribute to a complex lattice. The third optic ganglion, the lobula, is interposed between the medulla and the protocerebrum. It is the site of termination of the third-order neurones. The lobula in hymenopterans appears, in contrast to dipterans, odonates and lepidopterans, as a single neuropilic mass. A short review of the electrophysiological data concerning these two ganglia has been tentatively correlated with some of the anatomical data.

  13. Phenotypic transformation affects associative learning in the desert locust.

    PubMed

    Simões, Patrício M V; Niven, Jeremy E; Ott, Swidbert R

    2013-12-02

    In desert locusts, increased population densities drive phenotypic transformation from the solitarious to the gregarious phase within a generation [1-4]. Here we show that when presented with odor-food associations, the two extreme phases differ in aversive but not appetitive associative learning, with solitarious locusts showing a conditioned aversion more quickly than gregarious locusts. The acquisition of new learned aversions was blocked entirely in acutely crowded solitarious (transiens) locusts, whereas appetitive learning and prior learned associations were unaffected. These differences in aversive learning support phase-specific feeding strategies. Associative training with hyoscyamine, a plant alkaloid found in the locusts' habitat [5, 6], elicits a phase-dependent odor preference: solitarious locusts avoid an odor associated with hyoscyamine, whereas gregarious locusts do not. Remarkably, when solitarious locusts are crowded and then reconditioned with the odor-hyoscyamine pairing as transiens, the specific blockade of aversive acquisition enables them to override their prior aversive memory with an appetitive one. Under fierce food competition, as occurs during crowding in the field, this provides a neuroecological mechanism enabling locusts to reassign an appetitive value to an odor that they learned previously to avoid.

  14. A conceptual method for monitoring locust habitat

    USGS Publications Warehouse

    Howard, Stephen M.; Loveland, Thomas R.; Ohlen, Donald O.; Moore, Donald G.; Gallo, Kevin P.; Olsson, Jonathon

    1987-01-01

    A procedure to map and monitor vegetation conditions in near-real time was developed at the United States Geological Survey;s Earth Resources Observation Systems Data Center for use in locust control efforts. Meteorological satellite dat were acquired daily for 3 weeks in October and November 1986 over a 1.4-million-square-kilometer study area centered on Botswana in southern Africa. Advanced Very High Resolution Radiometer data were screened to remove cloud-contaminated data and registered to a 1-kilometer geographic base. Each day the normalized difference vegetation index (NDVI) was calculated to determine the presence and relative amounts of green vegetation in the area. Over a 10-day cycle, subsequent dates of NDVI data were composited to fill in data removed by the cloud-screening process. At any pixel location, the maximum NDVI value was retained. At the end of the 10-day cycle, a composite vegetation-greenness map was produced and another cycle started. Greenness-change maps were produced by comparing two 10-day composite greenness images. Automated map production procedures were used to merge the NDVI image data with cartographic data (boundaries, roads, tick marks) digitized from 1:1,000,000-scale operational navigation charts. The vegetation-greenness map shoes the current distribution of vegetation in the region and can be used to locate potential locust breeding area. The change map shows areas where increases and decreases in greenness have occurred between processing cycles. Significant areas of locust damage in remote regions are characterized by an unexpected decrease in greenness. These maps can be used by locust control teams to efficiently target areas for reconnaissance. In general, the procedures and products have utility for resource managers who are required to monitor vegetation resources over large geographic regions.

  15. [Comparative investigation of locust's phototactic visual spectrum effect and phototactic response to spectral illumination].

    PubMed

    Liu, Qi-Hang; Zhou, Qiang

    2014-07-01

    To provide theoretical support for determining locust's phototactic spectrum, and explore locust's phototactic mechanism stimulated by light, utilizing AvaSpec fiber-optic spectrometer system and AvaLight-DHS, the investigation of locust's phototactic visual spectrum effect after light energy stimulated locust's vision system was carried out and on this basis, utilizing the investigated device of locust's phototactic response to spectral illumination, the discrepancy of locust's phototactic response to spectral illumination was certificated comparatively. The results show that the degree of locust's vision system absorbing the single spectrum photon of 430, 545 and 610 nm is significant and there exists difference, and the behavioral response to orange, violet, green, and blue spectral light has the difference in selective sensitivity, with the intensity of response to violet light being the strongest. The degree of response to orange light is the maximum, simultaneously, locust's vision system absorbing spectral photon energy has selective difference and requirement of illumination time, moreover, the sensitive degree of locust's visual system to spectrum and the strength of the lighting energy, influencing locust's phototactic response degree, and the micro-response of locust's phototactic vision physiology, led by the photoelectric effect of locust absorbing sensitive photon and converting photon energy, is the reason for locust's phototactic orientation response. In addition, locust's phototactic visual spectrum effect, only when the biological photoelectric effect of locust's visual system is stimulated by spectral illumination, can present the sensitivity of the spectral absorption effect, so, using the stronger ultraviolet stimulation characteristic of violet light, the different sensitive stimulation of orange, green, blue spectral light on locust's phototactic vision, and combining orange, violet, green, blue spectral light field mechanism reasonably, can

  16. Assaying Visual Memory in the Desert Locust.

    PubMed

    Dillen, Senne; Chen, Ziwei; Broeck, Jozef Vanden

    2015-04-20

    The involvement of associative learning cues has been demonstrated in several stages of feeding and food selection. Short neuropeptide F (sNPF), an insect neuropeptide whose effects on feeding behavior have previously been well established, may be one of the factors bridging feeding and learning behavior. Recently, it was shown in Drosophila melanogaster that the targeted reduction of Drome-sNPF transcript levels significantly reduced sugar-rewarded olfactory memory. While Drosophila mainly relies on olfactory perception in its food searching behavior, locust foraging behavior is likely to be more visually orientated. Furthermore, a feeding-dependent regulation of Schgr-sNPF transcript levels has previously been observed in the optic lobes of the locust brain, suggesting a possible involvement in visual perception of food and visual associative memory in this insect species. In this study, we describe the development of a robust and reproducible assay allowing visual associative memory to be studied in the desert locust, Schistocerca gregaria. Furthermore, we performed an exploratory series of experiments, studying the role of Schgr-sNPF in this complex process.

  17. Locust dynamics: behavioral phase change and swarming.

    PubMed

    Topaz, Chad M; D'Orsogna, Maria R; Edelstein-Keshet, Leah; Bernoff, Andrew J

    2012-01-01

    Locusts exhibit two interconvertible behavioral phases, solitarious and gregarious. While solitarious individuals are repelled from other locusts, gregarious insects are attracted to conspecifics and can form large aggregations such as marching hopper bands. Numerous biological experiments at the individual level have shown how crowding biases conversion towards the gregarious form. To understand the formation of marching locust hopper bands, we study phase change at the collective level, and in a quantitative framework. Specifically, we construct a partial integrodifferential equation model incorporating the interplay between phase change and spatial movement at the individual level in order to predict the dynamics of hopper band formation at the population level. Stability analysis of our model reveals conditions for an outbreak, characterized by a large scale transition to the gregarious phase. A model reduction enables quantification of the temporal dynamics of each phase, of the proportion of the population that will eventually gregarize, and of the time scale for this to occur. Numerical simulations provide descriptions of the aggregation's structure and reveal transiently traveling clumps of gregarious insects. Our predictions of aggregation and mass gregarization suggest several possible future biological experiments.

  18. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is generally...

  19. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is generally...

  20. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is generally...

  1. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is generally...

  2. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is generally...

  3. A Locust Cage and Hatchery from Plastic Aquarium Tanks

    ERIC Educational Resources Information Center

    Stoneman, C. F.; And Others

    1973-01-01

    Describes how to construct a locust cage from two plastic aquaria and four coffee jars with plastic lids. Its advantages over a conventional locust cage include the inexpensive cost, lack of breakable glass, ease of cleaning, and visibility from all angles. (JR)

  4. A Locust Cage and Hatchery from Plastic Aquarium Tanks

    ERIC Educational Resources Information Center

    Stoneman, C. F.; And Others

    1973-01-01

    Describes how to construct a locust cage from two plastic aquaria and four coffee jars with plastic lids. Its advantages over a conventional locust cage include the inexpensive cost, lack of breakable glass, ease of cleaning, and visibility from all angles. (JR)

  5. Percussion as an alternative scarification for New Mexico locust and black locust seeds

    Treesearch

    Nabil Khadduri; John T. Harrington; Lee S. Rosner; David R. Dreesen

    2002-01-01

    Hot water and sulfuric acid soaks are traditional treatments for seeds of many temperate woody legumes, including locusts. However, these scarification techniques often produce inconsistent germination. Percussion scarification, where seeds are repeatedly propelled against a hard surface, was compared with hot water scarification to evaluate treatment efficacy for New...

  6. Biomechanical and dynamic mechanism of locust take-off

    NASA Astrophysics Data System (ADS)

    Chen, Dian-Sheng; Yin, Jun-Mao; Chen, Ke-Wei; Li, Zhen

    2014-10-01

    The biomimetic locust robot hopping vehicle has promising applications in planet exploration and reconnaissance. This paper explores the bionic dynamics model of locust jumping by using high-speed video and force analysis. This paper applies hybrid rigid-flexible mechanisms to bionic locust hopping and studies its dynamics with emphasis laid on the relationship between force and jumping performance. The hybrid rigid-flexible model is introduced in the analysis of locust mechanism to address the principles of dynamics that govern locust joints and mechanisms during energy storage and take-off. The dynamic response of the biomimetic mechanism is studied by considering the flexibility according to the locust jumping dynamics mechanism. A multi-rigid-body dynamics model of locust jumping is established and analyzed based on Lagrange method; elastic knee and tarsus mechanisms that were proposed in previous works are analyzed alongside the original bionic joint configurations and their machinery principles. This work offers primary theories for take-off dynamics and establishes a theoretical basis for future studies and engineering applications.

  7. Resource distribution mediates synchronization of physiological rhythms in locust groups

    PubMed Central

    Despland, Emma; Simpson, Stephen J

    2006-01-01

    Synchronized behaviour is common in animal groups. In ant colonies, synchronization occurs because active ants stimulate their neighbours to activity. We use oscillator theory to explain how stimulation from active neighbours synchronizes activity in groups of solitarious locusts via entrainment of internal physiological rhythms. We also show that the spatial distribution of food resources controls coupling between individual locusts and the emergence of synchronized activity. In locusts (Schistocerca gregaria), individual schedules of activity and quiescence arise from an irregular physiological oscillation in feeding excitation (i.e. hunger). We show that contact with an active neighbour increases the probability that a locust becomes active. This entrained activity decreases the time until the locust feeds, shifting the phase of its hunger oscillation. The locusts' internal physiological rhythms are thus brought into alignment and their activity becomes synchronized. When food resources are clumped, contact with active locusts increases, and this increase in the strength of coupling between individuals leads to greater synchronization of behaviour. Activity synchronization might have functional significance in inhibiting swarming when resources are dispersed and accelerating it in more favourable clumped environments. PMID:16777746

  8. A locust-inspired miniature jumping robot.

    PubMed

    Zaitsev, Valentin; Gvirsman, Omer; Ben Hanan, Uri; Weiss, Avi; Ayali, Amir; Kosa, Gabor

    2015-11-25

    Unmanned ground vehicles are mostly wheeled, tracked, or legged. These locomotion mechanisms have a limited ability to traverse rough terrain and obstacles that are higher than the robot's center of mass. In order to improve the mobility of small robots it is necessary to expand the variety of their motion gaits. Jumping is one of nature's solutions to the challenge of mobility in difficult terrain. The desert locust is the model for the presented bio-inspired design of a jumping mechanism for a small mobile robot. The basic mechanism is similar to that of the semilunar process in the hind legs of the locust, and is based on the cocking of a torsional spring by wrapping a tendon-like wire around the shaft of a miniature motor. In this study we present the jumping mechanism design, and the manufacturing and performance analysis of two demonstrator prototypes. The most advanced jumping robot demonstrator is power autonomous, weighs 23 gr, and is capable of jumping to a height of 3.35 m, covering a distance of 1.37 m.

  9. Neuromechanical simulation of the locust jump

    PubMed Central

    Cofer, D.; Cymbalyuk, G.; Heitler, W. J.; Edwards, D. H.

    2010-01-01

    The neural circuitry and biomechanics of kicking in locusts have been studied to understand their roles in the control of both kicking and jumping. It has been hypothesized that the same neural circuit and biomechanics governed both behaviors but this hypothesis was not testable with current technology. We built a neuromechanical model to test this and to gain a better understanding of the role of the semi-lunar process (SLP) in jump dynamics. The jumping and kicking behaviors of the model were tested by comparing them with a variety of published data, and were found to reproduce the results from live animals. This confirmed that the kick neural circuitry can produce the jump behavior. The SLP is a set of highly sclerotized bands of cuticle that can be bent to store energy for use during kicking and jumping. It has not been possible to directly test the effects of the SLP on jump performance because it is an integral part of the joint, and attempts to remove its influence prevent the locust from being able to jump. Simulations demonstrated that the SLP can significantly increase jump distance, power, total energy and duration of the jump impulse. In addition, the geometry of the joint enables the SLP force to assist leg flexion when the leg is flexed, and to assist extension once the leg has begun to extend. PMID:20228342

  10. Role of remote sensing in desert locust early warning

    NASA Astrophysics Data System (ADS)

    Cressman, Keith

    2013-01-01

    Desert locust (Schistocerca gregaria, Forskål) plagues have historically had devastating consequences on food security in Africa and Asia. The current strategy to reduce the frequency of plagues and manage desert locust infestations is early warning and preventive control. To achieve this, the Food and Agriculture Organization of the United Nations operates one of the oldest, largest, and best-known migratory pest monitoring systems in the world. Within this system, remote sensing plays an important role in detecting rainfall and green vegetation. Despite recent technological advances in data management and analysis, communications, and remote sensing, monitoring desert locusts and preventing plagues in the years ahead will continue to be a challenge from a geopolitical and financial standpoint for affected countries and the international donor community. We present an overview of the use of remote sensing in desert locust early warning.

  11. Occurrence and metabolism of scylloinositol in the locust.

    PubMed

    Candy, D J

    1967-06-01

    1. scylloInositol has been identified as a component of locust haemolymph, where it occurs in concentrations of 0.2-0.4mg./ml. 2. A simple method for the identification of scylloinositol is described. This has been used to demonstrate the presence of scylloinositol in five other insect species. 3. Locust phospholipids contain myoinositol but no scylloinositol. 4. Radioactivity from [(14)C]glucose is incorporated into myoinositol and scylloinositol by the locust in vivo. 5. Extracts of locust fat body catalyse the conversion of myoinositol into scylloinositol. This seems to take place by a two-step process in which myoinositol is first oxidized with NAD(+) to myoinosose-2, and the myoinosose-2 is stereospecifically reduced with NADPH to scylloinositol.

  12. Occurrence and metabolism of scylloinositol in the locust

    PubMed Central

    Candy, D. J.

    1967-01-01

    1. scylloInositol has been identified as a component of locust haemolymph, where it occurs in concentrations of 0·2–0·4mg./ml. 2. A simple method for the identification of scylloinositol is described. This has been used to demonstrate the presence of scylloinositol in five other insect species. 3. Locust phospholipids contain myoinositol but no scylloinositol. 4. Radioactivity from [14C]glucose is incorporated into myoinositol and scylloinositol by the locust in vivo. 5. Extracts of locust fat body catalyse the conversion of myoinositol into scylloinositol. This seems to take place by a two-step process in which myoinositol is first oxidized with NAD+ to myoinosose-2, and the myoinosose-2 is stereospecifically reduced with NADPH to scylloinositol. PMID:4383051

  13. Development of a locust bean processing device.

    PubMed

    Owolarafe, Oseni Kehinde; Adetan, Dare Aderibigbe; Olatunde, Gbenga Adebayo; Ajayi, Adebowale Oladeji; Okoh, Ile Kehinde

    2013-04-01

    A locust bean steaming, dehulling and separating machine was designed in this study by simulating the traditional processing operations. The machine consist of pressure cooking pot (as the cooking device) mounted on a separate stand and equipped with rocker- arm system to facilitate discharge of contents, a hopper made of mild steel sheet, the dehulling unit made of screwed shaft and abrasive barrel, a conical-shaped separating section equipped with paddles (made of aluminum material) and a standing frame to support the whole arrangement. The machine was evaluated by processing seed at cooking times of 30, 45, 60 and 90 min. The result indicated increase in dehulling efficiency with increase in cooking time from 30 to 60 min while it dropped at 90 min. The highest dehulling efficiency of 82% was obtained at cooking time of 60 min. The separation efficiency obtained at this optimal cooking time was 79%.

  14. Monitoring the plague of oriental migratory locust using multi-temporal Landsat TM imagery

    NASA Astrophysics Data System (ADS)

    Liu, Zhenbo; Ni, Shaoxiang; Zha, Yong; Shi, Xuezheng

    2006-03-01

    Locust plague is a kind of the world-wide biological calamity to agriculture. In China's history, more than 90% of locust plagues were caused by the oriental migratory locust, Locusta migratoria manilensis (Meyen). At the present time, it is difficult for monitoring and forecasting systems in this country to provide real time information of locust plague outbreak in large area. In order to adopt timely measures for prevention and control of locust outbreak, it is necessary to apply advanced remote sensing technology for monitoring and forecasting locust outbreak This paper introduces a case study on monitoring oriental migratory locust plague with remote sensing technology in 3 pilot sites, namely, Huangzao, Yangguangzhuang, and Tengnan, which were the 3 major locust damaged areas in Huanghua City, Hebei Province, China during the period of large scale oriental migratory locust breakout in 2002. In this study, locust damage intensity, areas with various damage intensities and their distribution in pilot sites are determined by means of comparison between Landsat ETM+ image of locust damaged vegetation on 31st May, 2002 and TM image of healthy vegetation before damage on 23rd May, 2002. Then, information of various locust distribution density in pilot sites is extracted by establishing the Locust Density Index (LDI).

  15. Role of wing pronation in evasive steering of locusts.

    PubMed

    Ribak, Gal; Rand, David; Weihs, Daniel; Ayali, Amir

    2012-07-01

    Evasive steering is crucial for flying in a crowded environment such as a locust swarm. We investigated how flying locusts alter wing-flapping symmetry in response to a looming object approaching from the side. Desert locusts (Schistocerca gregaria) were tethered to a rotatable shaft that allowed them to initiate a banked turn. A visual stimulus of an expending disk on one side of the locust was used to evoke steering while recording the change in wingbeat kinematics and electromyography (EMG) of metathoracic wing depressors. Locusts responded to the looming object by rolling to the contralateral direction. During turning, EMG of hindwing depressors showed an omission of one action potential in the subalar depressor (M129) of the hindwing inside the turn. This omission was associated with increased pronation of the same wing, reducing its angle-of-attack during the downstroke. The link between spike-omission in M129 and wing pronation was verified by stimulating the hindwing depressor muscles with an artificial motor pattern that included the misfire of M129. These results suggest that hindwing pronation is instrumental in rotating the body to the side opposite of the approaching threat. Turning away from the threat would be highly adaptive for collision avoidance when flying in dense swarms.

  16. Motion dazzle: a locust's eye view.

    PubMed

    Santer, Roger D

    2013-01-01

    Motion dazzle describes high-contrast patterns (e.g. zigzags on snakes and dazzle paint on World War I ships) that do not conceal an object, but inhibit an observer's perception of its motion. However, there is limited evidence for this phenomenon. Locusts have a pair of descending contralateral movement detector (DCMD) neurons which respond to predator-like looming objects and trigger escape responses. Within the network providing input to a DCMD, separate channels are excited when moving edges cause areas of the visual field to brighten or darken, respectively, and these stimuli interact antagonistically. When a looming square has an upper half and lower half that are both darker than background, it elicits a stronger DCMD response than the upper half does alone. However, when a looming square has a darker-than-background upper half and a brighter-than-background lower half, it elicits a weaker DCMD response than its upper half does alone. This effect allows high-contrast patterns to weaken and delay DCMD response parameters implicated in escape decisions, and is analogous to motion dazzle. However, the motion dazzle effect does not provide the best means of motion camouflage, because uniform bright squares, or low-contrast squares, elicit weaker DCMD responses than high-contrast, half dark, half bright squares.

  17. Comparative Isoenzyme Electrophoreses between the Brown-Spotted Locust, Cyrtacanthacris tatarica, and the Desert Locust, Schistocerca gregaria

    PubMed Central

    Elsayed, G.; Amer, S. A. M.

    2014-01-01

    The desert locust, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae), and the brownspotted locust, Cyrtacanthacris tatarica (Linné) (Orthoptera: Acrididae), were collected from Saudi Arabia to investigate their relationships. Native polyacrylamide gel electrophoreses of five arbitrarily chosen metabolic enzymes extracted from the leg muscles of the two locust taxa were conducted. These enzymes were acid phosphatase (Acph), alcohol dehydrogenase (Adh), β esterase (β est), malic enzyme (Mal) and malate dehydrogenase (Mdh). Twenty presumptive gene loci and 26 polymorphic alleles were recorded. Acph did not discriminate between the two locust species, while the other four isoenzymes discriminated between them. Most of the alleles were monomeric, but Mal and Mdh exhibited dimeric alleles in the samples of C. tatarica. β est fractions were more expressed in C. tatarica, and the three enzymes β est, Mal, and Mdh discriminated clearly between the two species. The similarity coefficient that was calculated according to the number of sharing alleles between the two locusts was found to be 0.69. The isoenzyme variation presented herein seemed to reflect either their physiological adaptation or the taxonomic consequences between the two taxa. Collecting more isoenzymes for more samples could have taxonomic value. PMID:25373167

  18. Dopaminergic modulation of phase reversal in desert locusts

    PubMed Central

    Alessi, Ahmad M.; O'Connor, Vincent; Aonuma, Hitoshi; Newland, Philip L.

    2014-01-01

    Phenotypic plasticity allows animals to modify their behavior, physiology, and morphology to adapt to environmental change. The global pest, the desert locust, shows two extreme phenotypes; a solitarious phase that is relatively harmless and a gregarious phase that forms swarms and causes extensive agricultural and economic damage. In the field, environmental conditions can drive isolated animals into crowded populations and previous studies have identified the biogenic amine serotonin as a key determinant of this transition. Here we take an integrated approach to investigate the neurochemical, physiological, and behavioral correlates defined by a laboratory based paradigm that mimics facets of swarm break down as gregarious locusts become isolated. Following isolation there was an increased propensity of locusts to avoid conspecifics, and show a reduced locomotion. Changes in choice behavior occurred within 1 h of isolation although isolation-related changes progressed with increased isolation time. Isolation was accompanied by changes in the levels of the biogenic amines dopamine, octopamine, and serotonin within the CNS within 1 h. Dopamine levels were higher in isolated animals and we focused on the role played by this transmitter in synaptic changes that may underpin solitarization. Dopamine reduced synaptic efficacy at a key central synapse between campaniform sensilla (CS) and a fast extensor tibiae motor neuron that is involved in limb movement. We also show that dopamine injection into the haemocoel was sufficient to induce solitarious-like behavior in otherwise gregarious locusts. Further, injection of a dopamine antagonist, fluphenazine, into isolated locusts induced gregarious-like behavior. This highlights that dopaminergic modulation plays an important role in the plasticity underpinning phase transition and sets a context to deepen the understanding of the complementary role that distinct neuromodulators play in polyphenism in locusts. PMID:25426037

  19. Locust bean gum: Exploring its potential for biopharmaceutical applications.

    PubMed

    Dionísio, Marita; Grenha, Ana

    2012-07-01

    Polysaccharides have been finding, in the last decades, very interesting and useful applications in the biomedical and, specifically, in the biopharmaceutical field. Locust bean gum is a polysaccharide belonging to the group of galactomannans, being extracted from the seeds of the carob tree (Ceratonia siliqua). This polymer displays a number of appealing characteristics for biopharmaceutical applications, among which its high gelling capacity should be highlighted. In this review, we describe critical aspects of locust bean gum, contributing for its role in biopharmaceutical applications. Physicochemical properties, as well as strong and effective synergies with other biomaterials are described. The potential for in vivo biodegradation is explored and the specific biopharmaceutical applications are discussed.

  20. Energy localization and frequency analysis in the locust ear.

    PubMed

    Malkin, Robert; McDonagh, Thomas R; Mhatre, Natasha; Scott, Thomas S; Robert, Daniel

    2014-01-06

    Animal ears are exquisitely adapted to capture sound energy and perform signal analysis. Studying the ear of the locust, we show how frequency signal analysis can be performed solely by using the structural features of the tympanum. Incident sound waves generate mechanical vibrational waves that travel across the tympanum. These waves shoal in a tsunami-like fashion, resulting in energy localization that focuses vibrations onto the mechanosensory neurons in a frequency-dependent manner. Using finite element analysis, we demonstrate that two mechanical properties of the locust tympanum, distributed thickness and tension, are necessary and sufficient to generate frequency-dependent energy localization.

  1. Locust sprouts reduce growth of yellow-poplar seedlings

    Treesearch

    Donald E. Beck; Charles E. McGee

    1974-01-01

    Dense thickets of black locust which often appear after clearcutting in the Southern Appalachians and Piedmont, can severely reduce growth of other desirable hardwoods. Released yellow-poplar seedlings were 51 percent taller and 79 percent larger in diameter than unreleased ones 6 years after treatment.

  2. Cellulolytic activity and structure of symbiotic bacteria in locust guts.

    PubMed

    Su, L-J; Liu, H; Li, Y; Zhang, H-F; Chen, M; Gao, X-H; Wang, F-Q; Song, A-D

    2014-09-29

    Locusts are able to digest the cellulose of Gramineae plants, resulting in their being considered as major crop pests. To illustrate the mechanism involved in cellulose digestion, the cellulolytic activity and zymography in the gut contents of 16 locust species were determined using carboxymethyl cellulose (CMC) as substrate. The diversity of gut symbiotic bacteria was studied using denaturing gradient gel electrophoresis (DGGE). The results showed that high CMC activity was present in Acrididae gut fluid (mean 356.4 U/g proteins). Of the 5 locust species, Oxya chinensis had the highest diversity of intestinal symbiotic bacteria, characterized by the DGGE profile containing more than 20 bands of 16S rRNA. Klebsiella pneumoniae, in the gut of Locusta migratoria manilensis, was identified as the most abundant symbiotic bacterium by DNA sequencing, with a relative abundance of 19.74%. In comparison, Methylobacterium sp was the most dominant species in the Atractomorpha sinensis gut, with a relative abundance of 29.04%. The results indicated that the cellulolytic enzymes and gut microbial communities probably reflected their phylogenetic relationship with different locust species and associated feeding strategies.

  3. Evidence for a pheromone in the locust borer

    Treesearch

    Jimmy R. Galford

    1977-01-01

    Laboratory studies have suggested the existence of a pheromone in the locust borer. Male beetles spent more time on bolts of wood exposed to virgin females than on control bolts. The females apparently deposited the pheromone on the bolts of wood and filter paper.

  4. Ecosystem carbon exchange in response to locust outbreaks in a temperate steppe.

    PubMed

    Song, Jian; Wu, Dandan; Shao, Pengshuai; Hui, Dafeng; Wan, Shiqiang

    2015-06-01

    It is predicted that locust outbreaks will occur more frequently under future climate change scenarios, with consequent effects on ecological goods and services. A field manipulative experiment was conducted to examine the responses of gross ecosystem productivity (GEP), net ecosystem carbon dioxide (CO2) exchange (NEE), ecosystem respiration (ER), and soil respiration (SR) to locust outbreaks in a temperate steppe of northern China from 2010 to 2011. Two processes related to locust outbreaks, natural locust feeding and carcass deposition, were mimicked by clipping 80 % of aboveground biomass and adding locust carcasses, respectively. Ecosystem carbon (C) exchange (i.e., GEP, NEE, ER, and SR) was suppressed by locust feeding in 2010, but stimulated by locust carcass deposition in both years (except SR in 2011). Experimental locust outbreaks (i.e., clipping plus locust carcass addition) decreased GEP and NEE in 2010 whereas they increased GEP, NEE, and ER in 2011, leading to neutral changes in GEP, NEE, and SR across the 2 years. The responses of ecosystem C exchange could have been due to the changes in soil ammonium nitrogen, community cover, and aboveground net primary productivity. Our findings of the transient and neutral changes in ecosystem C cycling under locust outbreaks highlight the importance of resistance, resilience, and stability of the temperate steppe in maintaining reliable ecosystem services, and facilitate the projections of ecosystem functioning in response to natural disturbance and climate change.

  5. Grip and detachment of locusts on inverted sandpaper substrates.

    PubMed

    Han, Longbao; Wang, Zhouyi; Ji, Aihong; Dai, Zhendong

    2011-12-01

    Locusts (Locusta migratoria manilensis) are characterized by their strong flying and grasping ability. Research on the grasping mechanism and behaviour of locusts on sloping substrates plays an important role in elucidating the mechanics of hexapod locomotion. Data on the maximum angles of slope at which locusts can grasp stably (critical angles of detachment) were obtained from high-speed video recordings at 215 fps. The grasping forces were collected by using two sensors, in situations where all left legs were standing on one and the right legs on the other sensor plate. These data were used to illustrate the grasping ability of locusts on slopes with varying levels of roughness. The grasping morphologies of locusts' bodies and tarsi were observed, and the surface roughness as well as diameters of their claw tips was measured under a microscope to account for the grasping mechanism of these insects on the sloping substrate. The results showed that the claw tips and part of the pads were in contact with the inverted substrate when the mean particle diameter was in the range of 15.3-40.5 µm. The interaction between pads and substrates may improve the stability of contact, and claw tips may play a key role in keeping the attachment reliable. A model was developed to explain the significant effects of the relative size of claw tips and mean particle diameter on grasping ability as well as the observed increase in lateral force (2.09-4.05 times greater than the normal force during detachment) with increasing slope angle, which indicates that the lateral force may be extremely important in keeping the contact reliable. This research lays the groundwork for the probable design and development of biomimetic robotics.

  6. Dynamics and stability of directional jumps in the desert locust

    PubMed Central

    Gvirsman, Omer

    2016-01-01

    Locusts are known for their ability to jump large distances to avoid predation. The jump also serves to launch the adult locust into the air in order to initiate flight. Various aspects of this important behavior have been studied extensively, from muscle physiology and biomechanics, to the energy storage systems involved in powering the jump, and more. Less well understood are the mechanisms participating in control of the jump trajectory. Here we utilise video monitoring and careful analysis of experimental directional jumps by adult desert locusts, together with dynamic computer simulation, in order to understand how the locusts control the direction and elevation of the jump, the residual angular velocities resulting from the jump and the timing of flapping-flight initiation. Our study confirms and expands early findings regarding the instrumental role of the initial body position and orientation. Both real-jump video analysis and simulations based on our expanded dynamical model demonstrate that the initial body coordinates of position (relative to the hind-legs ground-contact points) are dominant in predicting the jumps’ azimuth and elevation angles. We also report a strong linear correlation between the jumps’ pitch-angular-velocity and flight initiation timing, such that head downwards rotations lead to earlier wing opening. In addition to offering important insights into the bio-mechanical principles of locust jumping and flight initiation, the findings from this study will be used in designing future prototypes of a bio-inspired miniature jumping robot that will be employed in animal behaviour studies and environmental monitoring applications. PMID:27703846

  7. Anoxia induces thermotolerance in the locust flight system.

    PubMed

    Wu, B S; Lee, J K; Thompson, K M; Walker, V K; Moyes, C D; Robertson, R M

    2002-03-01

    Heat shock and anoxia are environmental stresses that are known to trigger similar cellular responses. In this study, we used the locust to examine stress cross-tolerance by investigating the consequences of a prior anoxic stress on the effects of a subsequent high-temperature stress. Anoxic stress and heat shock induced thermotolerance by increasing the ability of intact locusts to survive normally lethal temperatures. To determine whether induced thermotolerance observed in the intact animal was correlated with electrophysiological changes, we measured whole-cell K(+) currents and action potentials from locust neurons. K(+) currents recorded from thoracic neuron somata were reduced after anoxic stress and decreased with increases in temperature. Prior anoxic stress and heat shock increased the upper temperature limit for generation of an action potential during a subsequent heat stress. Although anoxia induced thermotolerance in the locust flight system, a prior heat shock did not protect locusts from a subsequent anoxic stress. To determine whether changes in bioenergetic status were implicated in whole-animal cross-tolerance, phosphagen levels and rates of mitochondrial respiration were assayed. Heat shock alone had no effect on bioenergetic status. Prior heat shock allowed rapid recovery after normally lethal heat stress but afforded no protection after a subsequent anoxic stress. Heat shock also afforded no protection against disruption of bioenergetic status after a subsequent exercise stress. These metabolite studies are consistent with the electrophysiological data that demonstrate that a prior exposure to anoxia can have protective effects against high-temperature stress but that heat shock does not induce tolerance to anoxia.

  8. Field Verification of the Prediction Model on Desert Locust Adult Phase Status From Density and Vegetation.

    PubMed

    Cissé, S; Ghaout, S; Babah Ebbe, M A; Kamara, S; Piou, C

    2016-01-01

    Previous studies investigated the effect of vegetation on density thresholds of adult Desert Locust gregarization from historical data in Mauritania. We examine here the prediction of locust phase based on adult density and vegetation conditions using the statistical model from Cisse et al. compared with actual behavior of Desert Locust adults observed in the field in Mauritania. From the 130 sites where adult locusts were found, the model predicted the phase of Desert Locust adults with a relatively small error of prediction of 6.1%. Preventive locust control should be rational, based on a risk assessment. The staff involved in implementation of the preventive control strategy needs specific indicators for when or where chemical treatment should be done. In this respect, we show here that the statistical model of Cisse et al. may be appropriate.

  9. Field Verification of the Prediction Model on Desert Locust Adult Phase Status From Density and Vegetation

    PubMed Central

    Cissé, S.; Ghaout, S.; Babah Ebbe, M. A; Kamara, S; Piou, C.

    2016-01-01

    Previous studies investigated the effect of vegetation on density thresholds of adult Desert Locust gregarization from historical data in Mauritania. We examine here the prediction of locust phase based on adult density and vegetation conditions using the statistical model from Cisse et al. compared with actual behavior of Desert Locust adults observed in the field in Mauritania. From the 130 sites where adult locusts were found, the model predicted the phase of Desert Locust adults with a relatively small error of prediction of 6.1%. Preventive locust control should be rational, based on a risk assessment. The staff involved in implementation of the preventive control strategy needs specific indicators for when or where chemical treatment should be done. In this respect, we show here that the statistical model of Cisse et al. may be appropriate. PMID:27432351

  10. Mutualism between the desert locust Schistocerca gregaria and its gut microbiota.

    PubMed

    Dillon, Rod; Charnley, Keith

    2002-10-01

    The desert locust Schistocerca gregaria contains a relatively simple but abundant gut microbiota which originated from the insect's diet. The gut bacterial population is dominated by Enterobacteriaceae with a major component of enterococci. Microbial metabolism of secondary plant chemicals in the locust gut produces phenolics useful to the locust host. Some products are antimicrobial and contribute to host defense against pathogens, others are employed by the host as components of the aggregation pheromone. This dual benefit suggests a closer degree of integration between the locust and its microbial community than was previously suspected.

  11. Locust bean gum: Exploring its potential for biopharmaceutical applications

    PubMed Central

    Dionísio, Marita; Grenha, Ana

    2012-01-01

    Polysaccharides have been finding, in the last decades, very interesting and useful applications in the biomedical and, specifically, in the biopharmaceutical field. Locust bean gum is a polysaccharide belonging to the group of galactomannans, being extracted from the seeds of the carob tree (Ceratonia siliqua). This polymer displays a number of appealing characteristics for biopharmaceutical applications, among which its high gelling capacity should be highlighted. In this review, we describe critical aspects of locust bean gum, contributing for its role in biopharmaceutical applications. Physicochemical properties, as well as strong and effective synergies with other biomaterials are described. The potential for in vivo biodegradation is explored and the specific biopharmaceutical applications are discussed. PMID:22923958

  12. Behavioral analysis of polarization vision in tethered flying locusts.

    PubMed

    Mappes, M; Homberg, U

    2004-01-01

    For spatial navigation many insects rely on compass information derived from the polarization pattern of the sky. We demonstrate that tethered flying desert locusts (Schistocerca gregaria) show e-vector-dependent yaw-torque responses to polarized light presented from above. A slowly rotating polarizer (5.3 degrees s(-1)) induced periodic changes in yaw torque corresponding to the 180 degrees periodicity of the stimulus. Control experiments with a rotating diffuser, a weak intensity pattern, and a stationary polarizer showed that the response is not induced by intensity gradients in the stimulus. Polarotaxis was abolished after painting the dorsal rim areas of the compound eyes black, but remained unchanged after painting the eyes except the dorsal rim areas. During rotation of the polarizer, two e-vectors (preferred and avoided e-vector) induced no turning responses: they were broadly distributed from 0 to 180 degrees but, for a given animal, were perpendicular to each other. The data demonstrate polarization vision in the desert locust, as shown previously for bees, flies, crickets, and ants. Polarized light is perceived through the dorsal rim area of the compound eye, suggesting that polarization vision plays a role in compass navigation of the locust.

  13. Giant Cell Arteritis

    MedlinePlus

    ... Patient / Caregiver Diseases & Conditions Giant Cell Arteritis Giant Cell Arteritis Fast Facts Giant cell arteritis (GCA) is ... polymyalgia rheumatica (also called PMR). What is giant cell arteritis? GCA is a type of vasculitis or ...

  14. Retinally-generated saccadic suppression of a locust looming-detector neuron: investigations using a robot locust.

    PubMed

    Santer, R D; Stafford, R; Rind, F C

    2004-11-22

    A fundamental task performed by many visual systems is to distinguish apparent motion caused by eye movements from real motion occurring within the environment. During saccadic eye movements, this task is achieved by inhibitory signals of central and retinal origin that suppress the output of motion-detecting neurons. To investigate the retinally-generated component of this suppression, we used a computational model of a locust looming-detecting pathway that experiences saccadic suppression. This model received input from the camera of a mobile robot that performed simple saccade-like movements, allowing the model's response to simplified real stimuli to be tested. Retinally-generated saccadic suppression resulted from two inhibitory mechanisms within the looming-detector's input architecture. One mechanism fed inhibition forward through the network, inhibiting the looming-detector's initial response to movement. The second spread inhibition laterally within the network, suppressing the looming-detector's maintained response to movement. These mechanisms prevent a looming-detector model response to whole-field visual stimuli. In the locust, this mechanism of saccadic suppression may operate in addition to centrally-generated suppression. Because lateral inhibition is a common feature of early visual processing in many organisms, we discuss whether the mechanism of retinally-generated saccadic suppression found in the locust looming-detector model may also operate in these species.

  15. Retinally-generated saccadic suppression of a locust looming-detector neuron: investigations using a robot locust.

    PubMed Central

    Santer, R. D.; Stafford, R.; Rind, F. C.

    2004-01-01

    A fundamental task performed by many visual systems is to distinguish apparent motion caused by eye movements from real motion occurring within the environment. During saccadic eye movements, this task is achieved by inhibitory signals of central and retinal origin that suppress the output of motion-detecting neurons. To investigate the retinally-generated component of this suppression, we used a computational model of a locust looming-detecting pathway that experiences saccadic suppression. This model received input from the camera of a mobile robot that performed simple saccade-like movements, allowing the model's response to simplified real stimuli to be tested. Retinally-generated saccadic suppression resulted from two inhibitory mechanisms within the looming-detector's input architecture. One mechanism fed inhibition forward through the network, inhibiting the looming-detector's initial response to movement. The second spread inhibition laterally within the network, suppressing the looming-detector's maintained response to movement. These mechanisms prevent a looming-detector model response to whole-field visual stimuli. In the locust, this mechanism of saccadic suppression may operate in addition to centrally-generated suppression. Because lateral inhibition is a common feature of early visual processing in many organisms, we discuss whether the mechanism of retinally-generated saccadic suppression found in the locust looming-detector model may also operate in these species. PMID:16849153

  16. [Phosphorus transfer between mixed poplar and black locust seedlings].

    PubMed

    He, Wei; Jia, Liming; Hao, Baogang; Wen, Xuejun; Zhai, Mingpu

    2003-04-01

    In this paper, the 32P radio-tracer technique was applied to study the ways of phosphorus transfer between poplar (Populus euramericana cv. 'I-214') and black locust (Robinia pseudoacacia). A five compartment root box (18 cm x 18 cm x 26 cm) was used for testing the existence of the hyphal links between the roots of two tree species when inoculated with vesicular-arbuscular (VA) mycorrhizal fungus (Glomus mosseae). Populus I-214 (donor) and Robinia pseudoacacia (receiver) were grown in two terminal compartments, separated by a 2 cm root-free soil layer. The root compartments were lined with bags of nylon mesh (38 microns) that allowed the passage of hyphae but not roots. The top soil of a mixed stand of poplar and black locust, autoclaved at 121 degrees C for one hour, was used for growing seedlings for testing. In 5 compartment root box, mycorrhizal root colonization of poplar was 34%, in which VA mycorrhizal fungus was inoculated, whereas 26% mycorrhizal root colonization was observed in black locust, the other terminal compartment, 20 weeks after planting. No root colonization was observed in non-inoculated plant pairs. This indicated that the mycorrhizal root colonization of black locust was caused by hyphal spreading from the poplar. Test of tracer isotope of 32P showed that the radioactivity of the treatment significantly higher than that of the control (P < 0.05), 14 days from the tracer applied, to 27 days after, when VA mycorrhizal fungus was inoculated in poplar root. Furthermore, mycorrhizal interconnections between the roots of poplar and black locust seedlings was observed in situ by binocular in root box. All these experiments showed that the hyphal links was formed between the roots of two species of trees inoculated by VA mycorrhizal fungus. Four treatments were designed according to if there were two nets (mesh 38 microns), 2 cm apart, between the poplar and black locust, and if the soil in root box was pasteurized. Most significant differences of

  17. A broadly tuned odorant receptor in neurons of trichoid sensilla in locust, Locusta migratoria.

    PubMed

    You, Yinwei; Smith, Dean P; Lv, Mingyue; Zhang, Long

    2016-12-01

    Insects have evolved sophisticated olfactory reception systems to sense exogenous chemical signals. Odorant receptors (ORs) on the membrane of chemosensory neurons are believed to be key molecules in sensing exogenous chemical cues. ORs in different species of insects are diverse and should tune a species to its own specific semiochemicals relevant to their survival. The orthopteran insect, locust (Locusta migratoria), is a model hemimetabolous insect. There is very limited knowledge on the functions of locust ORs although many locust OR genes have been identified in genomic sequencing experiments. In this paper, a locust OR, LmigOR3 was localized to neurons housed in trichoid sensilla by in situ hybridization. LmigOR3 was expressed as a transgene in Drosophila trichoid olfactory neurons (aT1) lacking the endogenous receptor Or67d and the olfactory tuning curve and dose-response curves were established for this locust receptor. The results show that LmigOR3 sensitizes neurons to ketones, esters and heterocyclic compounds, indicating that LmigOR3 is a broadly tuned receptor. LmigOR3 is the first odorant receptor from Orthoptera that has been functionally analyzed in the Drosophila aT1 system. This work demonstrates the utility of the Drosophila aT1 system for functional analysis of locust odorant receptors and suggests that LmigOR3 may be involved in detecting food odorants, or perhaps locust body volatiles that may help us to develop new control methods for locusts.

  18. A broadly tuned odorant receptor in neurons of trichoid sensilla in locust, Locusta migratoria.

    PubMed

    You, Yinwei; Smith, Dean P; Lv, Mingyue; Zhang, Long

    2016-10-27

    Insects have evolved sophisticated olfactory reception systems to sense exogenous chemical signals. Odorant receptors (ORs) on the membrane of chemosensory neurons are believed to be key molecules in sensing exogenous chemical cues. ORs in different species of insects are diverse and should tune a species to its own specific semiochemicals relevant to their survival. The orthopteran insect, locust (Locusta migratoria), is a model hemimetabolous insect. There is very limited knowledge on the functions of locust ORs although many locust OR genes have been identified in genomic sequencing experiments. In this paper, a locust OR, LmigOR3 was localized to neurons housed in trichoid sensilla by in situ hybridization. LmigOR3 was expressed as a transgene in Drosophila trichoid olfactory neurons (aT1) lacking the endogenous receptor Or67d and the olfactory tuning curve and dose-response curves were established for this locust receptor. The results show that LmigOR3 sensitizes neurons to ketones, esters and heterocyclic compounds, indicating that LmigOR3 is a broadly tuned receptor. LmigOR3 is the first odorant receptor from Orthoptera that has been functionally analyzed in the Drosophila aT1 system. This work demonstrates the utility of the Drosophila aT1 system for functional analysis of locust odorant receptors and suggests that LmigOR3 may be involved in detecting food odorants, or perhaps locust body volatiles that may help us to develop new control methods for locusts.

  19. An assessment of black locust in northern U.S. forests

    Treesearch

    Cassandra M. Kurtz; Mark H. Hansen

    2017-01-01

    Black locust (Robinia pseudoacacia), a tree of the legume family (Fabaceae), is native to the southern Appalachian Mountains (Pennsylvania to Alabama), Ozark Plateau, and mid-south (Fig. 1). Black locust wood is utilized for firewood, fence posts, and building due to its strength and durability. The prolific pealike blossoms are aesthetically...

  20. Mass spectral determination of phenylacetonitrile (PAN) levels in body tissues of adult desert locust, Schistocerca gregaria

    USDA-ARS?s Scientific Manuscript database

    : Wings and legs of the gregarious desert locust, Schistocerca gregaria have been shown to be release sites of phenylacetonitrile (PAN), the major adult male-produced pheromone. However, there is limited information on the distribution of PAN within the locust. Here we show, using gas chromatograph...

  1. Motor neurone responses during a postural reflex in solitarious and gregarious desert locusts.

    PubMed

    Blackburn, Laura M; Ott, Swidbert R; Matheson, Tom; Burrows, Malcolm; Rogers, Stephen M

    2010-08-01

    Desert locusts show extreme phenotypic plasticity and can change reversibly between two phases that differ radically in morphology, physiology and behaviour. Solitarious locusts are cryptic in appearance and behaviour, walking slowly with the body held close to the ground. Gregarious locusts are conspicuous in appearance and much more active, walking rapidly with the body held well above the ground. During walking, the excursion of the femoro-tibial (F-T) joint of the hind leg is smaller in solitarious locusts, and the joint is kept more flexed throughout an entire step. Under open loop conditions, the slow extensor tibiae (SETi) motor neurone of solitarious locusts shows strong tonic activity that increases at more extended F-T angles. SETi of gregarious locusts by contrast showed little tonic activity. Simulated flexion of the F-T joint elicits resistance reflexes in SETi in both phases, but regardless of the initial and final position of the leg, the spiking rate of SETi during these reflexes was twice as great in solitarious compared to gregarious locusts. This increased sensory-motor gain in the neuronal networks controlling postural reflexes in solitarious locusts may be linked to the occurrence of pronounced behavioural catalepsy in this phase similar to other cryptic insects such as stick insects.

  2. Survival of bristly locust (Robinia hispida L.) in an emulated organic silvopasture

    USDA-ARS?s Scientific Manuscript database

    Bristly locust (Robinia hispida L.), a native tree legume which has received relatively little scientific attention from an agronomic perspective, could have value as livestock browse. The objective of this research was to assess transplant survival of bristly locust in an experimental silvopasture...

  3. Survival of bristly locust (Robinia hispida) in an emulated organic silvopasture

    USDA-ARS?s Scientific Manuscript database

    Bristly locust is a native tree legume with an extensive range throughout much of the eastern US and Canada. Bristly locust is about 3 m tall, produces pink flowers, and the branches, petioles, flower stalks, and fruits are covered by soft, inoffensive bristles. Little agronomic research has been co...

  4. Cannibalism can drive the evolution of behavioural phase polyphenism in locusts.

    PubMed

    Guttal, Vishwesha; Romanczuk, Pawel; Simpson, Stephen J; Sword, Gregory A; Couzin, Iain D

    2012-10-01

    During outbreaks, locust swarms can contain millions of insects travelling thousands of kilometers while devastating vegetation and crops. Such large-scale spatial organization is preceded locally by a dramatic density-dependent phenotypic transition in multiple traits. Behaviourally, low-density 'solitarious' individuals avoid contact with one another; above a critical local density, they undergo a rapid behavioural transition to the 'gregarious phase' whereby they exhibit mutual attraction. Although proximate causes of this phase polyphenism have been widely studied, the ultimate driving factors remain unclear. Using an individual-based evolutionary model, we reveal that cannibalism, a striking feature of locust ecology, could lead to the evolution of density-dependent behavioural phase-change in juvenile locusts. We show that this behavioural strategy minimizes risk associated with cannibalistic interactions and may account for the empirically observed persistence of locust groups during outbreaks. Our results provide a parsimonious explanation for the evolution of behavioural plasticity in locusts.

  5. Object approach computation by a giant neuron and its relationship with the speed of escape in the crab Neohelice.

    PubMed

    Oliva, Damián; Tomsic, Daniel

    2016-11-01

    Upon detection of an approaching object, the crab Neohelice granulata continuously regulates the direction and speed of escape according to ongoing visual information. These visuomotor transformations are thought to be largely accounted for by a small number of motion-sensitive giant neurons projecting from the lobula (third optic neuropil) towards the supraesophageal ganglion. One of these elements, the monostratified lobula giant neuron of type 2 (MLG2), proved to be highly sensitive to looming stimuli (a 2D representation of an object approach). By performing in vivo intracellular recordings, we assessed the response of the MLG2 neuron to a variety of looming stimuli representing objects of different sizes and velocities of approach. This allowed us to: (1) identify some of the physiological mechanisms involved in the regulation of the MLG2 activity and test a simplified biophysical model of its response to looming stimuli; (2) identify the stimulus optical parameters encoded by the MLG2 and formulate a phenomenological model able to predict the temporal course of the neural firing responses to all looming stimuli; and (3) incorporate the MLG2-encoded information of the stimulus (in terms of firing rate) into a mathematical model able to fit the speed of the escape run of the animal. The agreement between the model predictions and the actual escape speed measured on a treadmill for all tested stimuli strengthens our interpretation of the computations performed by the MLG2 and of the involvement of this neuron in the regulation of the animal's speed of run while escaping from objects approaching with constant speed.

  6. The Locust Standard Brain: A 3D Standard of the Central Complex as a Platform for Neural Network Analysis

    PubMed Central

    el Jundi, Basil; Heinze, Stanley; Lenschow, Constanze; Kurylas, Angela; Rohlfing, Torsten; Homberg, Uwe

    2009-01-01

    Many insects use the pattern of polarized light in the sky for spatial orientation and navigation. We have investigated the polarization vision system in the desert locust. To create a common platform for anatomical studies on polarization vision pathways, Kurylas et al. (2008) have generated a three-dimensional (3D) standard brain from confocal microscopy image stacks of 10 male brains, using two different standardization methods, the Iterative Shape Averaging (ISA) procedure and the Virtual Insect Brain (VIB) protocol. Comparison of both standardization methods showed that the VIB standard is ideal for comparative volume analysis of neuropils, whereas the ISA standard is the method of choice to analyze the morphology and connectivity of neurons. The central complex is a key processing stage for polarization information in the locust brain. To investigate neuronal connections between diverse central-complex neurons, we generated a higher-resolution standard atlas of the central complex and surrounding areas, using the ISA method based on brain sections from 20 individual central complexes. To explore the usefulness of this atlas, two central-complex neurons, a polarization-sensitive columnar neuron (type CPU1a) and a tangential neuron that is activated during flight, the giant fan-shaped (GFS) neuron, were reconstructed 3D from brain sections. To examine whether the GFS neuron is a candidate to contribute to synaptic input to the CPU1a neuron, we registered both neurons into the standardized central complex. Visualization of both neurons revealed a potential connection of the CPU1a and GFS neurons in layer II of the upper division of the central body. PMID:20161763

  7. Dynamic flight stability in the desert locust Schistocerca gregaria.

    PubMed

    Taylor, Graham K; Thomas, Adrian L R

    2003-08-01

    Here we provide the first formal quantitative analysis of dynamic stability in a flying animal. By measuring the longitudinal static stability derivatives and mass distribution of desert locusts Schistocerca gregaria, we find that their static stability and static control responses are insufficient to provide asymptotic longitudinal dynamic stability unless they are sensitive to pitch attitude (measured with respect to an inertial or earth-fixed frame) as well as aerodynamic incidence (measured relative to the direction of flight). We find no evidence for a 'constant-lift reaction', previously supposed to keep lift production constant over a range of body angles, and show that such a reaction would be inconsequential because locusts can potentially correct for pitch disturbances within a single wingbeat. The static stability derivatives identify three natural longitudinal modes of motion: one stable subsidence mode, one unstable divergence mode, and one stable oscillatory mode (which is present with or without pitch attitude control). The latter is identified with the short period mode of aircraft, and shown to consist of rapid pitch oscillations with negligible changes in forward speed. The frequency of the short period mode (approx. 10 Hz) is only half the wingbeat frequency (approx. 22 Hz), so the mode would become coupled with the flapping cycle without adequate damping. Pitch rate damping is shown to be highly effective for this purpose - especially at the small scales associated with insect flight - and may be essential in stabilising locust flight. Although having a short period mode frequency close to the wingbeat frequency risks coupling, it is essential for control inputs made at the level of a single wingbeat to be effective. This is identified as a general constraint on flight control in flying animals.

  8. The effect of changing topography on the coordinated marching of locust nymphs

    PubMed Central

    Amichay, Guy; Ariel, Gil

    2016-01-01

    Collective motion has traditionally been studied in the lab in homogeneous, obstacle-free environments, with little work having been conducted with changing landscapes or topography. Here, the impact of spatial heterogeneity on the collective motion exhibited by marching desert locust nymphs was studied under controlled lab conditions. Our experimental circular arenas, incorporating a funnel-like narrowing followed by re-widening, did not constitute a major barrier to the locusts but, rather, mimicked a changing topography in the natural environment. We examined its effects on macroscopic features of the locust collective behavior, as well as the any changes in their marching kinematics. A major finding was that of the limited extent to which the changing topography affected system-level features of the marching locust group, such as the order parameter and the fraction of walking individuals, despite increased crowding at the funnel. Overall, marching kinematics was also very little affected, suggesting that locust marching bands adjust to the environment, with little effect on the overall dynamics of the group. These findings are in contrast to recent theoretical results predicting that environmental heterogeneities qualitatively alter the dynamics of collectively moving particles; and highlight the crucial role of rapid individual plasticity and adaptability in the dynamics of flocks and swarms. Our study has revealed other important features of the marching behavior of the desert locust in addition to its robustness: the locusts demonstrated both, clear thigmotaxis and a tendency to spread-out and fill the available space. PMID:27994966

  9. MicroRNA-276 promotes egg-hatching synchrony by up-regulating brm in locusts

    PubMed Central

    He, Jing; Chen, Qianquan; Wei, Yuanyuan; Jiang, Feng; Yang, Meiling; Hao, Shuguang; Guo, Xiaojiao; Chen, Dahua; Kang, Le

    2016-01-01

    Developmental synchrony, the basis of uniform swarming, migration, and sexual maturation, is an important strategy for social animals to adapt to variable environments. However, the molecular mechanisms underlying developmental synchrony are largely unexplored. The migratory locust exhibits polyphenism between gregarious and solitarious individuals, with the former displaying more synchronous sexual maturation and migration than the latter. Here, we found that the egg-hatching time of gregarious locusts was more uniform compared with solitarious locusts and that microRNA-276 (miR-276) was expressed significantly higher in both ovaries and eggs of gregarious locusts than in solitarious locusts. Interestingly, inhibiting miR-276 in gregarious females and overexpressing it in solitarious females, respectively, caused more heterochronic and synchronous hatching of progeny eggs. Moreover, miR-276 directly targeted a transcription coactivator gene, brahma (brm), resulting in its up-regulation. Knockdown of brm not only resulted in asynchronous egg hatching in gregarious locusts but also impaired the miR-276–induced synchronous egg hatching in solitarious locusts. Mechanistically, miR-276 mediated brm activation in a manner that depended on the secondary structure of brm, namely, a stem-loop around the binding site of miR-276. Collectively, our results unravel a mechanism by which miR-276 enhances brm expression to promote developmental synchrony and provide insight into regulation of developmental homeostasis and population sustaining that are closely related to biological synchrony. PMID:26729868

  10. Multisensor monitoring system for assessment of locust hazard risk in the Lake Balkhash drainage basin.

    PubMed

    Propastin, Pavel

    2012-12-01

    Satellite and ground-based data were combined in a monitoring system to quantify the link between climate conditions and the risk of locust infestations in the southern part of Lake Balkhash's drainage basin in the Republic of Kazakhstan. In this monitoring system, the Normalized Difference Vegetation Index (NDVI), derived from the SPOT-VGT satellite, was used for mapping potential locust habitats and monitoring their area throughout 1998 to 2007. TOPEX/Poseidon and Jason 1 altimeter data were used to track the interannual dynamics of water level in Balkhash Lake. Climate conditions were represented by weather records for air temperature and precipitation during the same period. The classification procedure, based on an analysis of multitemporal dynamics of SPOT-VGT NDVI values observed by individual vegetation classes, generated annual areas of ten land-cover types, which were then categorized as areas with low, medium, and high risk for locust infestation. Statistical analyses showed significant influences of the climatic parameters and the Balkhash Lake hydrological regime on the spatial extend of annual areas of potential locust habitats. The results also indicate that the linkages between locust infestation risk and environmental factors are characterized by time lags. The expansion of locust risk areas are usually preceded by dry, hot years and lower water levels in Balkhash Lake when larger areas of reed grass are free from seasonal flooding. Years with such conditions are favourable for locust outbreaks due to expansion of the habitat areas suitable for locust oviposition and nymphal development. In contrast, years with higher water levels in Balkhash Lake and lower temperature decrease the potential locust habitat area.

  11. Locust bean gum: processing, properties and food applications--a review.

    PubMed

    Barak, Sheweta; Mudgil, Deepak

    2014-05-01

    Locust bean gum or carob gum is a galactomannan obtained from seed endosperm of carob tree i.e. Ceratonia siliqua. It is widely utilized as an additive in various industries such as food, pharmaceuticals, paper, textile, oil well drilling and cosmetics. Industrial applications of locust bean gum are due to its ability to form hydrogen bonding with water molecule. It is also beneficial in the control of many health problems like diabetes, bowel movements, heart disease and colon cancer due to its dietary fiber action. This article focuses on production, processing, composition, properties, food applications and health benefits of locust bean gum.

  12. Epigenetic remodelling of brain, body and behaviour during phase change in locusts.

    PubMed

    Burrows, Malcolm; Rogers, Stephen M; Ott, Swidbert R

    2011-07-26

    The environment has a central role in shaping developmental trajectories and determining the phenotype so that animals are adapted to the specific conditions they encounter. Epigenetic mechanisms can have many effects, with changes in the nervous and musculoskeletal systems occurring at different rates. How is the function of an animal maintained whilst these transitions happen? Phenotypic plasticity can change the ways in which animals respond to the environment and even how they sense it, particularly in the context of social interactions between members of their own species. In the present article, we review the mechanisms and consequences of phenotypic plasticity by drawing upon the desert locust as an unparalleled model system. Locusts change reversibly between solitarious and gregarious phases that differ dramatically in appearance, general physiology, brain function and structure, and behaviour. Solitarious locusts actively avoid contact with other locusts, but gregarious locusts may live in vast, migrating swarms dominated by competition for scarce resources and interactions with other locusts. Different phase traits change at different rates: some behaviours take just a few hours, colouration takes a lifetime and the muscles and skeleton take several generations. The behavioural demands of group living are reflected in gregarious locusts having substantially larger brains with increased space devoted to higher processing. Phase differences are also apparent in the functioning of identified neurons and circuits. The whole transformation process of phase change pivots on the initial and rapid behavioural decision of whether or not to join with other locusts. The resulting positive feedback loops from the presence or absence of other locusts drives the process to completion. Phase change is accompanied by dramatic changes in neurochemistry, but only serotonin shows a substantial increase during the critical one- to four-hour window during which gregarious

  13. The mechanics of elevation control in locust jumping.

    PubMed

    Sutton, G P; Burrows, M

    2008-06-01

    How do animals control the trajectory of ballistic motions like jumping? Targeted jumps by a locust, which are powered by a rapid extension of the tibiae of both hind legs, require control of the take-off angle and speed. To determine how the locust controls these parameters, we used high speed images of jumps and mechanical analysis to reach three conclusions: (1) the extensor tibiae muscle applies equal and opposite torques to the femur and tibia, which ensures that tibial extension accelerates the centre of mass of the body along a straight line; (2) this line is parallel to a line drawn from the distal end of the tibia through the proximal end of the femur; (3) the slope of this line (the angle of elevation) is not affected if the two hind legs extend asynchronously. The mechanics thus uncouple the control of elevation and speed, allowing simplified and independent control mechanisms. Jump elevation is controlled mechanically by the initial positions of the hind legs and jump speed is determined by the energy stored within their elastic processes, which allows us to then propose which proprioceptors are involved in controlling these quantities.

  14. The regulation of glycolysis in perfused locust flight muscle

    PubMed Central

    Ford, W. C. L.; Candy, D. J.

    1972-01-01

    Concentrations of glycolytic intermediates, amino acids and possible regulator substances were measured in extracts from locust thoracic muscles perfused under different conditions. The conversion of [14C]glucose into intermediates and CO2 by muscle preparations was also followed. When muscles perfused with glucose were made anaerobic changes in metabolite concentrations occurred that could be accounted for by an activation of phosphofructokinase and pyruvate kinase. When butyrate and glucose were present in the perfusion medium the rate of glycolytic flux was lower than with glucose alone, and the aldolase reaction appeared to be inhibited. When butyrate alone was supplied to the muscle the concentrations of most glycolytic intermediates were similar to those found when glucose was supplied. Iodoacetate caused changes in concentrations of intermediates that appeared to result from inhibition of glyceraldehyde 3-phosphate dehydrogenase. Fluoroacetate-poisoned muscles showed a high citrate concentration, but no obvious site of inhibition by citrate was apparent in the glycolytic pathway. Mechanisms for control of glycolysis in locust flight muscle are discussed and related to the known properties of isolated enzymes. It is proposed that trehalase, hexokinase, phosphofructokinase, aldolase, and pyruvate kinase may be control enzymes in this tissue. PMID:4266373

  15. ERTS surveys a 500 km squared locust breeding site in Saudi Arabia. [Red Sea coastal plain

    NASA Technical Reports Server (NTRS)

    Pedgley, D. E.

    1974-01-01

    From September 1972 to January 1973, ERTS-1 precisely located a 500 sq km area on the Red Sea coastal plain of Saudi Arabia within which the Desert Locust (Schistocerca gregaria, Forsk.) bred successfully and produced many small swarms. Growth of vegetation shown by satellite imagery was confirmed from ground surveys and raingauge data. The experiment demonstrates the feasibility of detecting potential locust breeding sites by satellite, and shows that an operational satellite would be a powerful tool for routine survey of the 3 x 10 to the 7th power sq km invasion area of the Desert Locust in Africa and Asia, as well as of other locust species in the arid and semi-arid tropics.

  16. Surgical lesion of the anterior optic tract abolishes polarotaxis in tethered flying locusts, Schistocerca gregaria.

    PubMed

    Mappes, Martina; Homberg, Uwe

    2007-01-01

    Many insects can detect the polarization pattern of the blue sky and rely on polarization vision for sky compass orientation. In laboratory experiments, tethered flying locusts perform periodic changes in flight behavior under a slowly rotating polarizer even if one eye is painted black. Anatomical tracing studies and intracellular recordings have suggested that the polarization vision pathway in the locust brain involves the anterior optic tract and tubercle, the lateral accessory lobe, and the central complex of the brain. To investigate whether visual pathways through the anterior optic tract mediate polarotaxis in the desert locust, we transected the tract on one side and tested polarotaxis (1) with both eyes unoccluded and (2) with the eye of the intact hemisphere painted black. In the second group of animals, but not in the first group, polarotaxis was abolished. Sham operations did not impair polarotaxis. The experiments show that the anterior optic tract is an indispensable part of visual pathways mediating polarotaxis in the desert locust.

  17. Form vision in the insect dorsal ocelli: an anatomical and optical analysis of the Locust Ocelli.

    PubMed

    Berry, Richard P; Warrant, Eric J; Stange, Gert

    2007-05-01

    The dorsal ocelli are commonly considered to be incapable of form vision, primarily due to underfocused dioptrics. We investigate the extent to which this is true of the ocelli of the locust Locusta migratoria. Locust ocelli contain thick lenses with a pronounced concavity on the inner surface, and a deep clear zone separating retina and lens. In agreement with previous research, locust ocellar lenses were found to be decidedly underfocused with respect to the retina. Nevertheless, the image formed at the level of the retina contains substantial information that may be extractable by individual photoreceptors. Contrary to the classical view it is concluded that some capacity for resolution is present in the locust ocelli.

  18. Diversity of gut microbiota increases with aging and starvation in the desert locust.

    PubMed

    Dillon, Rod J; Webster, Gordon; Weightman, Andrew J; Keith Charnley, A

    2010-01-01

    Here we report the effects of starvation and insect age on the diversity of gut microbiota of adult desert locusts, Schistocerca gregaria, using denaturing gradient gel electrophoretic (DGGE) analysis of bacterial 16S rRNA genes. Sequencing of excised DGGE bands revealed the presence of only one potentially novel uncultured member of the Gammaproteobacteria in the guts of fed, starved, young or old locusts. Most of the 16S rRNA gene sequences were closely related to known cultured bacterial species. DGGE profiles suggested that bacterial diversity increased with insect age and did not provide evidence for a characteristic locust gut bacterial community. Starved insects are often more prone to disease, probably because they compromise on immune defence. However, the increased diversity of Gammaproteobacteria in starved locusts shown here may improve defence against enteric threats because of the role of gut bacteria in colonization resistance.

  19. Two dopamine receptors play different roles in phase change of the migratory locust.

    PubMed

    Guo, Xiaojiao; Ma, Zongyuan; Kang, Le

    2015-01-01

    The migratory locust, Locusta migratoria, shows remarkable phenotypic plasticity at behavioral, physiological, and morphological levels in response to fluctuation in population density. Our previous studies demonstrated that dopamine (DA) and the genes in the dopamine metabolic pathway mediate phase change in Locusta. However, the functions of different dopamine receptors in modulating locust phase change have not been fully explored. In the present study, DA concentration in the brain increased during crowding and decreased during isolation. The expression level of dopamine receptor 1 (Dop1) increased from 1 to 4 h of crowding, but remained unchanged during isolation. Injection of Dop1 agonist SKF38393 into the brains of solitary locusts promoted gregarization, induced conspecific attraction-response and increased locomotion. RNAi knockdown of Dop1 and injection of antagonist SCH23390 in gregarious locusts induced solitary behavior, promoted the shift to repulsion-response and reduced locomotion. By contrast, the expression level of dopamine receptor 2 (Dop2) gradually increased during isolation, but remained stable during crowding. During the isolation of gregarious locusts, injection of Dop2 antagonist S(-)-sulpiride or RNAi knockdown of Dop2 inhibited solitarization, maintained conspecific attraction-response and increased locomotion; by comparison, the isolated controls displayed conspecific repulsion-response and weaker motility. Activation of Dop2 in solitary locusts through injection of agonist, R(-)-TNPA, did not affect their behavioral state. Thus, DA-Dop1 signaling in the brain of Locusta induced the gregariousness, whereas DA-Dop2 signaling mediated the solitariness. Our study demonstrated that Dop1 and Dop2 modulated locust phase change in two different directions. Further investigation of Locusta Dop1 and Dop2 functions in modulating phase change will improve our understanding of the molecular mechanism underlying phenotypic plasticity in locusts.

  20. Arousal Facilitates Collision Avoidance Mediated by a Looming Sensitive Visual Neuron in a Flying Locust

    PubMed Central

    Rind, F. Claire; Santer, Roger D.; Wright, Geraldine A.

    2008-01-01

    Locusts have two large collision-detecting neurons, the descending contralateral movement detectors (DCMDs) that signal object approach and trigger evasive glides during flight. We sought to investigate whether vision for action, when the locust is in an aroused state rather than a passive viewer, significantly alters visual processing in this collision-detecting pathway. To do this we used two different approaches to determine how the arousal state of a locust affects the prolonged periods of high-frequency spikes typical of the DCMD response to approaching objects that trigger evasive glides. First, we manipulated arousal state in the locust by applying a brief mechanical stimulation to the hind leg; this type of change of state occurs when gregarious locusts accumulate in high-density swarms. Second, we examined DCMD responses during flight because flight produces a heightened physiological state of arousal in locusts. When arousal was induced by either method we found that the DCMD response recovered from a previously habituated state; that it followed object motion throughout approach; and—most important—that it was significantly more likely to generate the maintained spike frequencies capable of evoking gliding dives even with extremely short intervals (1.8 s) between approaches. Overall, tethered flying locusts responded to 41% of simulated approaching objects (sets of 6 with 1.8 s ISI). When we injected epinastine, the neuronal octopamine receptor antagonist, into the hemolymph responsiveness declined to 12%, suggesting that octopamine plays a significant role in maintaining responsiveness of the DCMD and the locust to visual stimuli during flight. PMID:18509080

  1. Arousal facilitates collision avoidance mediated by a looming sensitive visual neuron in a flying locust.

    PubMed

    Rind, F Claire; Santer, Roger D; Wright, Geraldine A

    2008-08-01

    Locusts have two large collision-detecting neurons, the descending contralateral movement detectors (DCMDs) that signal object approach and trigger evasive glides during flight. We sought to investigate whether vision for action, when the locust is in an aroused state rather than a passive viewer, significantly alters visual processing in this collision-detecting pathway. To do this we used two different approaches to determine how the arousal state of a locust affects the prolonged periods of high-frequency spikes typical of the DCMD response to approaching objects that trigger evasive glides. First, we manipulated arousal state in the locust by applying a brief mechanical stimulation to the hind leg; this type of change of state occurs when gregarious locusts accumulate in high-density swarms. Second, we examined DCMD responses during flight because flight produces a heightened physiological state of arousal in locusts. When arousal was induced by either method we found that the DCMD response recovered from a previously habituated state; that it followed object motion throughout approach; and--most important--that it was significantly more likely to generate the maintained spike frequencies capable of evoking gliding dives even with extremely short intervals (1.8 s) between approaches. Overall, tethered flying locusts responded to 41% of simulated approaching objects (sets of 6 with 1.8 s ISI). When we injected epinastine, the neuronal octopamine receptor antagonist, into the hemolymph responsiveness declined to 12%, suggesting that octopamine plays a significant role in maintaining responsiveness of the DCMD and the locust to visual stimuli during flight.

  2. The mechanism for microsporidian parasite suppression of the hindgut bacteria of the migratory locust Locusta migratoria manilensis.

    PubMed

    Tan, Shu-Qian; Zhang, Kai-Qi; Chen, Hong-Xing; Ge, Yang; Ji, Rong; Shi, Wang-Peng

    2015-11-27

    Locusts aggregate into bands of nymphs and swarms of adults that can pose a major threat to crop. Previous studies have shown that infection by the microsporidian parasite Paranosema locustae prevents locust aggregation behavior and we show that gut bacteria, which produce components of locust aggregation pheromones, are substantially reduced in locusts infected with P. locustae. We found that P. locustae could reduce the diversity, abundance and community composition of Locusta migratoria's gut bacteria. The parasite infection was also shown to interrupt the peroxidase activity of locust hindgut. Genome-wide expression analysis showed that the parasite infection suppressed peroxidase mRNA relative expression of locust hindgut, but had no effects on attacin expression and superoxide dismutase at 16 d post-inoculation with 20,000 P. locustae spores. Our findings reveal the mechanisms by which P. locustae impairs bacterial diversity and community structure of Locusta migratoria's gut bacteria.

  3. The mechanism for microsporidian parasite suppression of the hindgut bacteria of the migratory locust Locusta migratoria manilensis

    PubMed Central

    Tan, Shu-qian; Zhang, Kai-qi; Chen, Hong-xing; Ge, Yang; Ji, Rong; Shi, Wang-peng

    2015-01-01

    Locusts aggregate into bands of nymphs and swarms of adults that can pose a major threat to crop. Previous studies have shown that infection by the microsporidian parasite Paranosema locustae prevents locust aggregation behavior and we show that gut bacteria, which produce components of locust aggregation pheromones, are substantially reduced in locusts infected with P. locustae. We found that P. locustae could reduce the diversity, abundance and community composition of Locusta migratoria’s gut bacteria. The parasite infection was also shown to interrupt the peroxidase activity of locust hindgut. Genome-wide expression analysis showed that the parasite infection suppressed peroxidase mRNA relative expression of locust hindgut, but had no effects on attacin expression and superoxide dismutase at 16 d post-inoculation with 20,000 P. locustae spores. Our findings reveal the mechanisms by which P. locustae impairs bacterial diversity and community structure of Locusta migratoria’s gut bacteria. PMID:26612678

  4. Argonaute 1 is indispensable for juvenile hormone mediated oogenesis in the migratory locust, Locusta migratoria.

    PubMed

    Song, Jiasheng; Guo, Wei; Jiang, Feng; Kang, Le; Zhou, Shutang

    2013-09-01

    Juvenile hormone (JH) is the primary hormone controlling vitellogenesis and oocyte maturation in the migratory locust Locusta migratoria, an evolutionarily primitive insect species with panoistic ovaries. However, molecular mechanisms of locust oogenesis remain unclear and the role of microRNA (miRNA) in JH mediated locust vitellogenesis and oocyte maturation has not been explored. Using miRNA sequencing and quantification with small RNA libraries derived from fat bodies of JH-deprived versus JH analog-exposed female adult locusts, we have identified 83 JH up-regulated and 60 JH down-regulated miRNAs. QRT-PCR validation has confirmed that transcription of selected miRNAs responded to JH administration and correlated with changes in endogenous hemolymph JH titers. Depletion of Argonaute 1 (Ago1), a key regulator of miRNA biogenesis and function by RNAi in female adult locusts dramatically decreased the expression of vitellogenin (Vg) and severely impaired follicular epithelium development, terminal oocyte maturation and ovarian growth. Our data indicate that Ago1 and Ago1-dependent miRNAs play a crucial role in locust vitellogenesis and egg production.

  5. Listening to the environment: hearing differences from an epigenetic effect in solitarious and gregarious locusts

    PubMed Central

    Gordon, Shira D.; Jackson, Joseph C.; Rogers, Stephen M.; Windmill, James F. C.

    2014-01-01

    Locusts display a striking form of phenotypic plasticity, developing into either a lone-living solitarious phase or a swarming gregarious phase depending on population density. The two phases differ extensively in appearance, behaviour and physiology. We found that solitarious and gregarious locusts have clear differences in their hearing, both in their tympanal and neuronal responses. We identified significant differences in the shape of the tympana that may be responsible for the variations in hearing between locust phases. We measured the nanometre mechanical responses of the ear's tympanal membrane to sound, finding that solitarious animals exhibit greater displacement. Finally, neural experiments signified that solitarious locusts have a relatively stronger response to high frequencies. The enhanced response to high-frequency sounds in the nocturnally flying solitarious locusts suggests greater investment in detecting the ultrasonic echolocation calls of bats, to which they are more vulnerable than diurnally active gregarious locusts. This study highlights the importance of epigenetic effects set forth during development and begins to identify how animals are equipped to match their immediate environmental needs. PMID:25274362

  6. Listening to the environment: hearing differences from an epigenetic effect in solitarious and gregarious locusts.

    PubMed

    Gordon, Shira D; Jackson, Joseph C; Rogers, Stephen M; Windmill, James F C

    2014-11-22

    Locusts display a striking form of phenotypic plasticity, developing into either a lone-living solitarious phase or a swarming gregarious phase depending on population density. The two phases differ extensively in appearance, behaviour and physiology. We found that solitarious and gregarious locusts have clear differences in their hearing, both in their tympanal and neuronal responses. We identified significant differences in the shape of the tympana that may be responsible for the variations in hearing between locust phases. We measured the nanometre mechanical responses of the ear's tympanal membrane to sound, finding that solitarious animals exhibit greater displacement. Finally, neural experiments signified that solitarious locusts have a relatively stronger response to high frequencies. The enhanced response to high-frequency sounds in the nocturnally flying solitarious locusts suggests greater investment in detecting the ultrasonic echolocation calls of bats, to which they are more vulnerable than diurnally active gregarious locusts. This study highlights the importance of epigenetic effects set forth during development and begins to identify how animals are equipped to match their immediate environmental needs.

  7. Construction of a Hypervirulent and Specific Mycoinsecticide for Locust Control

    PubMed Central

    Fang, Weiguo; Lu, Hsiao-Ling; King, Glenn F.; St. Leger, Raymond J.

    2014-01-01

    Locusts and grasshoppers (acridids) are among the worst pests of crops and grasslands worldwide. Metarhizium acridum, a fungal pathogen that specifically infects acridids, has been developed as a control agent but its utility is limited by slow kill time and greater expense than chemical insecticides. We found that expression of four insect specific neurotoxins improved the efficacy of M. acridum against acridids by reducing lethal dose, time to kill and food consumption. Coinoculating recombinant strains expressing AaIT1(a sodium channel blocker) and hybrid-toxin (a blocker of both potassium and calcium channels), produced synergistic effects, including an 11.5-fold reduction in LC50, 43% reduction in LT50 and a 78% reduction in food consumption. However, specificity was retained as the recombinant strains did not cause disease in non-acridids. Our results identify a repertoire of toxins with different modes of action that improve the utility of fungi as specific control agents of insects. PMID:25475694

  8. Increased muscular volume and cuticular specialisations enhance jump velocity in solitarious compared with gregarious desert locusts, Schistocerca gregaria.

    PubMed

    Rogers, Stephen M; Riley, Joanna; Brighton, Caroline; Sutton, Gregory P; Cullen, Darron A; Burrows, Malcolm

    2016-03-01

    The desert locust, Schistocerca gregaria, shows a strong phenotypic plasticity. It can develop, depending upon population density, into either a solitarious or gregarious phase that differs in many aspects of behaviour, physiology and morphology. Prominent amongst these differences is that solitarious locusts have proportionately longer hind femora than gregarious locusts. The hind femora contain the muscles and energy-storing cuticular structures that propel powerful jumps using a catapult-like mechanism. We show that solitarious locusts jump on average 23% faster and 27% further than gregarious locusts, and attribute this improved performance to three sources: first, a 17.5% increase in the relative volume of their hind femur, and hence muscle volume; second, a 24.3% decrease in the stiffness of the energy-storing semi-lunar processes of the distal femur; and third, a 4.5% decrease in the stiffness of the tendon of the extensor tibiae muscle. These differences mean that solitarious locusts can generate more power and store more energy in preparation for a jump than can gregarious locusts. This improved performance comes at a cost: solitarious locusts expend nearly twice the energy of gregarious locusts during a single jump and the muscular co-contraction that energises the cuticular springs takes twice as long. There is thus a trade-off between achieving maximum jump velocity in the solitarious phase against the ability to engage jumping rapidly and repeatedly in the gregarious phase.

  9. Identifying the breeding areas of locusts in the Yellow River estuary using Landsat ETM+ imagery

    NASA Astrophysics Data System (ADS)

    Liu, Qingsheng; Liu, Gaohuan; Yang, Yuzhen; Liu, Peng; Huang, Jianjie

    2006-03-01

    The Yellow River Estuary became an important plague region of locusts because of its special geographic location. Many years' survey data showed that the environment was the chief factor that influenced locust pest occurring. In the recent years, because the amount of water from the Yellow River and precipitation reduced and distributed asymmetrically, and soil salinization became serious much more, and many farmlands went out of cultivation, which improved the habitats for locusts, the plague of locusts happened frequently under condign climate. The field survey data from 1991 to 2000 showed that the plague of locust became more aggravating year after year. Therefore, it is important to monitor and control the plague of locusts. According to many years' investigation data analysis, got the condign habitat conditions for Locusta Migratoria Manilensis (Meyen) in the Yellow River Estuary. So the breeding areas of locusts monitoring with remote sensing imagery was to identify those regions according to the condign habitat conditions. Landsat ETM+ imagery (2000-05-02) data was chosen to identify the breeding areas of locusts in the Yellow River Estuary. Firstly classified Landsat TM imagery (2000-5-2) and extract reed lands and lawn lands and slightly salinized soils. Secondly made mask images through transforming these three raster classes into vector layers, then calculated a anti-atmospheric visible light vegetation index VARIg = (B2-B3)/(B2+B3-B1). According to field investigation data of vegetation fractional cover in 2000, got the relationship between vegetation fractional cover and VARIg values, 70% to 3.0, 50% to 2.3. As a result, the infrequent areas were where VARIg values were great than 3.0, and the moderate areas were where VARIg values were between 2.3 and 3.0, and frequent areas were where VARIg values were under 2.3. According to statistical analysis, the infrequent areas were percent 10 of the lands that have the condign soil salt content for locust

  10. Giant Magnons Meet Giant Gravitons

    SciTech Connect

    Hofman, Diego M.

    2008-07-28

    We study the worldsheet reflection matrix of a string attached to a D-brane in AdS{sub 5}xS{sup 5}. The D-brane corresponds to a maximal giant graviton that wraps an S{sup 3} inside S{sup 5}. In the gauge theory, the open string is described by a spin chain with boundaries. We focus on open strings with a large SO(6) charge and define an asymptotic boundary reflection matrix. Using the symmetries of the problem, we review the computation of the boundary reflection matrix, up to a phase. We also discuss weak and strong coupling computations where we obtain the overall phase factor and test our exact results.

  11. Characterization and comparative profiling of the small RNA transcriptomes in two phases of locust

    PubMed Central

    Wei, Yuanyuan; Chen, Shuang; Yang, Pengcheng; Ma, Zongyuan; Kang, Le

    2009-01-01

    Background All the reports on insect small RNAs come from holometabolous insects whose genome sequence data are available. Therefore, study of hemimetabolous insect small RNAs could provide more insights into evolution and function of small RNAs in insects. The locust is an important, economically harmful hemimetabolous insect. Its phase changes, as a phenotypic plasticity, result from differential gene expression potentially regulated at both the post-transcriptional level, mediated by small RNAs, and the transcriptional level. Results Here, using high-throughput sequencing, we characterize the small RNA transcriptome in the locust. We identified 50 conserved microRNA families by similarity searching against miRBase, and a maximum of 185 potential locust-specific microRNA family candidates were identified using our newly developed method independent of locust genome sequence. We also demonstrate conservation of microRNA*, and evolutionary analysis of locust microRNAs indicates that the generation of miRNAs in locusts is concentrated along three phylogenetic tree branches: bilaterians, coelomates, and insects. Our study identified thousands of endogenous small interfering RNAs, some of which were of transposon origin, and also detected many Piwi-interacting RNA-like small RNAs. Comparison of small RNA expression patterns of the two phases showed that longer small RNAs were expressed more abundantly in the solitary phase and that each category of small RNAs exhibited different expression profiles between the two phases. Conclusions The abundance of small RNAs in the locust might indicate a long evolutionary history of post-transcriptional gene expression regulation, and differential expression of small RNAs between the two phases might further disclose the molecular mechanism of phase changes. PMID:19146710

  12. Late Pliocene and Quaternary Eurasian locust infestations in the Canary Archipelago

    USGS Publications Warehouse

    Meco, J.; Muhs, D.R.; Fontugne, M.; Ramos, A.J.; Lomoschitz, A.; Patterson, D.

    2011-01-01

    The Canary Archipelago has long been a sensitive location to record climate changes of the past. Interbedded with its basalt lavas are marine deposits from the principal Pleistocene interglacials, as well as aeolian sands with intercalated palaeosols. The palaeosols contain African dust and innumerable relict egg pods of a temperate-region locust (cf. Dociostaurus maroccanusThunberg 1815). New ecological and stratigraphical information reveals the geological history of locust plagues (or infestations) and their palaeoclimatic significance. Here, we show that the first arrival of the plagues to the Canary Islands from Africa took place near the end of the Pliocene, ca. 3Ma, and reappeared with immense strength during the middle Late Pleistocene preceding MIS (marine isotope stage) 11 (ca. 420ka), MIS 5.5 (ca. 125ka) and probably during other warm interglacials of the late Middle Pleistocene and the Late Pleistocene. During the Early Holocene, locust plagues may have coincided with a brief cool period in the current interglacial. Climatically, locust plagues on the Canaries are a link in the chain of full-glacial arid-cold climate (calcareous dunes), early interglacial arid-sub-humid climate (African dust inputs and locust plagues), peak interglacial warm-humid climate (marine deposits with Senegalese fauna), transitional arid-temperate climate (pedogenic calcretes), and again full-glacial arid-cold climate (calcareous dunes) oscillations. During the principal interglacials of the Pleistocene, the Canary Islands recorded the migrations of warm Senegalese marine faunas to the north, crossing latitudes in the Euro-African Atlantic. However, this northward marine faunal migration was preceded in the terrestrial realm by interglacial infestations of locusts. ??? Locust plagues, Canary Islands, Late Pliocene, Pleistocene, Holocene, palaeoclimatology. ?? 2010 The Authors, Lethaia ?? 2010 The Lethaia Foundation.

  13. Composition and emission dynamics of migratory locust volatiles in response to changes in developmental stages and population density.

    PubMed

    Wei, Jianing; Shao, Wenbo; Wang, Xianhui; Ge, Jin; Chen, Xiangyong; Yu, Dan; Kang, Le

    2017-02-01

    Chemical communication plays an important role in density-dependent phase change in locusts. However, the volatile components and emission patterns of the migratory locust, Locusta migratoria, are largely unknown. In this study, we identified the chemical compositions and emission dynamics of locust volatiles from the body and feces and associated them with developmental stages, sexes and phase changes. The migratory locust shares a number of volatile components with the desert locust (Schistocerca gregaria), but the emission dynamics of the two locust species are significantly different. The body odors of the gregarious nymphs in the migratory locust consisted of phenylacetonitrile (PAN), benzaldehyde, guaiacol, phenol, aliphatic acids and 2,3-butanediol, and PAN was the dominant volatile. Volatiles from the fecal pellets of the nymphs primarily consist of guaiacol and phenol. Principal component analysis (PCA) showed significant differences in the volatile profiles between gregarious and solitary locusts. PAN and 4-vinylanisole concentrations were significantly higher in gregarious individuals than in solitary locusts. Gregarious mature males released significantly higher amounts of PAN and 4-vinylanisole during adulthood than mature females and immature adults of both sexes. Furthermore, PAN and 4-vinylanisole were completely lost in gregarious nymphs during the solitarization process, but were obtained by solitary nymphs during gregarization. The amounts of benzaldehyde, guaiacol and phenol only unidirectionally decreased from solitary to crowded treatment. Aliphatic aldehydes (C7 to C10), which were previously reported as locust volatiles, are now identified as environmental contaminants. Therefore, our results illustrate the precise odor profiles of migratory locusts during developmental stages, sexes and phase change. However, the function and role of PAN and other aromatic compounds during phase transition need further investigation. © 2016 Institute of

  14. An analysis of the contrasting fates of locust swarms on the plains of North America and East Asia

    NASA Astrophysics Data System (ADS)

    Yu, G.; Ke, X.; Shen, H. D.; Li, Y. F.

    2013-03-01

    Prior to ~1880 AD locust swarms periodically raged across both the North American Plains (NAP) and East Asian Plains (EAP). After this date, locust outbreaks almost never recurred on the NAP but have continued to cause problems on the EAP. The large quantities of pesticides used in the major agriculture regions of the NAP in the late 1870s have been suggested as a possible reason for the disappearance of locust outbreaks in this area. Extensive applications of modern, i.e. more effective, chemical pesticides were also used in the granary regions of the EAP in the 1950s in an effort to reduce pest outbreaks. However, locust swarms returned again in many areas of China in the 1960s. Therefore, locust extinction on the NAP still remains a puzzle. Frequent locust outbreaks on the EAP over the past 130 yr may offer clues to the key factors that control the disappearance of locust outbreaks on the NAP. This study analysed the climate extremes and monthly temperature-precipitation combinations for the NAP and EAP, and found that differences in the frequencies of these climate combinations resulted in the contrasting locust fates in the two regions: restricting locust outbreaks in the NAP but inducing such events in the EAP. Validation shows that severe EAP locust outbreak years were coincidental with extreme climate-combination years. Therefore, we suggest that changes in frequency, extremes and trends in climate can explain why the fate of locust outbreaks in the EAP was different from that in the NAP. The results also suggest that, with present global warming trends, precautionary measures should be taken to make sure other similar pest infestations do not occur in either region.

  15. A case study of the Australian Plague Locust Commission and environmental due diligence: why mere legislative compliance is no longer sufficient for environmentally responsible locust control in Australia.

    PubMed

    Story, Paul G; Walker, Paul W; McRae, Heath; Hamilton, John G

    2005-07-01

    The Australian Plague Locust Commission (APLC) manages locust populations across 2 million square kilometers of eastern Australia using the aerial application of chemical and biological control agents to protect agricultural production. This occurs via a preventative control strategy involving ultralow-volume spray equipment to distribute small droplets of control agent over a target area. The economic costs of, and potential gains stemming from, locust control are well documented. The application of insecticides, however, to fragile arid and semiarid ecosystems is a task that brings with it both real and perceived environmental issues. The APLC is proactive in addressing these issues through a combination of targeted environmental operational research, an ISO-14001-aligned Environmental Management System (EMS), and links with environmental regulatory and research institutions. Increasing due diligence components within Australian environmental legislation dictate that mere legislative compliance is no longer sufficient for industries to ensure that they meet their environmental obligations. The development of external research links and the formulation of an EMS for locust control have enabled the APLC to identify environmental issues and trends, quantify objective environmental targets and strategies, and facilitate continuous improvement in its environmental performance, while maintaining stakeholder support. This article outlines the environmental issues faced by the APLC, the research programs in place to address these issues, and the procedures in place to incorporate research findings into the organization's operational structure.

  16. Insects in relation to black locust culture on surface-mine spoil in Kentucky, with emphasis on the locust twig borer, Ecdytolopha insiticiana Zell. (Lepidoptera: Tortricidae)

    SciTech Connect

    Thoeny, W.T.

    1986-01-01

    This research evaluated the impacts of herbivorous insects, emphasizing the locust twig borer, Ecdytolopha insiticiana Zeller, on black locust, Robinia pseudoacacia L., coppice production on a coal surface-mine spoil site in southeastern Kentucky. The natural history of E. insiticiana was also studied. The locust twig borer was a persistent and damaging pest in first-year coppice, which provided suitable larval habitat throughout the growing season. The locust leafminer, Odontota dorsalis (Thunberg), fed minimally on first-year coppice foliage except during 1983, when trees were severely drought-stressed. Soil-applied granular carbofuran significantly reduced infestations. Lindane stem treatments were not effective, but entire-tree applications did reduce herbivory. Stump sprouts with reduced levels of herbivory grew significantly taller than controls at both spacings in 1983, but only at the more dense spacing in 1984. Blacklight trap collections revealed two generations/year, and adults were present from early May until late August. Four species of hymenopterous and two species of dipterous parasitoids were recovered from E. insiticiana larvae.

  17. Predicting avian distributions to evaluate spatiotemporal overlap with locust control operations in eastern Australia.

    PubMed

    Szabo, Judit K; Davy, Pamela J; Hooper, Michael J; Astheimer, Lee B

    2009-12-01

    Locusts and grasshoppers cause considerable economic damage to agriculture worldwide. The Australian Plague Locust Commission uses multiple pesticides to control locusts in eastern Australia. Avian exposure to agricultural pesticides is of conservation concern, especially in the case of rare and threatened species. The aim of this study was to evaluate the probability of pesticide exposure of native avian species during operational locust control based on knowledge of species occurrence in areas and times of application. Using presence-absence data provided by the Birds Australia Atlas for 1998 to 2002, we developed a series of generalized linear models to predict avian occurrences on a monthly basis in 0.5 degrees grid cells for 280 species over 2 million km2 in eastern Australia. We constructed species-specific models relating occupancy patterns to survey date and location, rainfall, and derived habitat preference. Model complexity depended on the number of observations available. Model output was the probability of occurrence for each species at times and locations of past locust control operations within the 5-year study period. Given the high spatiotemporal variability of locust control events, the variability in predicted bird species presence was high, with 108 of the total 280 species being included at least once in the top 20 predicted species for individual space-time events. The models were evaluated using field surveys collected between 2000 and 2005, at sites with and without locust outbreaks. Model strength varied among species. Some species were under- or over-predicted as times and locations of interest typically did not correspond to those in the prediction data set and certain species were likely attracted to locusts as a food source. Field surveys demonstrated the utility of the spatially explicit species lists derived from the models but also identified the presence of a number of previously unanticipated species. These results also emphasize

  18. Non-swarming grasshoppers exhibit density-dependent phenotypic plasticity reminiscent of swarming locusts.

    PubMed

    Gotham, Steven; Song, Hojun

    2013-11-01

    Locusts are well known for exhibiting an extreme form of density-dependent phenotypic plasticity known as locust phase polyphenism. At low density, locust nymphs are cryptically colored and shy, but at high density they transform into conspicuously colored and gregarious individuals. Most of what we know about locust phase polyphenism come from the study of the desert locust Schistocerca gregaria (Forskål), which is a devastating pest species affecting many countries in North Africa and the Middle East. The desert locust belongs to the grasshopper genus Schistocerca Stål, which includes mostly non-swarming, sedentary species. Recent phylogenetic studies suggest that the desert locust is the earliest branching lineage within Schistocerca, which raises a possibility that the presence of density-dependent phenotypic plasticity may be a plesiomorphic trait for the whole genus. In order to test this idea, we have quantified the effect of rearing density in terms of the resulting behavior, color, and morphology in two non-swarming Schistocerca species native to Florida. When reared in both isolated and crowded conditions, the two non-swarming species, Schistocerca americana (Drury) and Schistocerca serialis cubense (Saussure) clearly exhibited plastic reaction norms in all traits measured, which were reminiscent of the desert locust. Specifically, we found that both species were more active and more attracted to each other when reared in a crowded condition than in isolation. They were mainly bright green in color when isolated, but developed strong black patterns and conspicuous background colors when crowded. We found a strong effect of rearing density in terms of size. There were also more mechanoreceptor hairs on the outer face of the hind femora in the crowded nymphs in both species. Although both species responded similarly, there were some clear species-specific differences in terms of color and behavior. Furthermore, we compare and contrast our findings with

  19. Intestinal peptides as circulating hormones: release of tachykinin-related peptide from the locust and cockroach midgut.

    PubMed

    Winther, A M; Nässel, D R

    2001-04-01

    Tachykinin-related peptides (TRPs) in the locust Locusta migratoria and the cockroach Leucophaea maderae have stimulatory effects on some muscles that are not innervated by TRP-containing neurons. Thus, these tissues may be affected by circulating TRPs. Here, we have investigated whether the midgut is the source of circulating TRPs. TRP-immunoreactive material in the locust midgut is found only in the endocrine cells of the gut epithelium. In both species of insect, the endocrine cells contain several isoforms of TRPs, as determined by immunocytochemistry and a combination of chromatography (HPLC) and enzyme immunoassay (ELISA). The release of TRPs was investigated by ELISA using isolated midguts of the locust and cockroach. Elevated levels of K(+) in the bathing saline induced the release of TRP from the midgut of both species. To examine the release of TRPs into the circulation in vivo, we measured haemolymph levels of TRPs in fed and starved locusts. The concentration of TRP-immunoreactive material in fed locusts was estimated to be 0.15 nmol l(-1), and this increased approximately fourfold in insects starved for 24 h. In accordance with this observation, the content of TRP-immunoreactive material in the midgut was lower in starved locusts than in fed locusts. Although part of the increased blood concentration of TRPs may be due to reduced blood volume, our data suggest that TRPs are released as hormones from the midgut of the locust and cockroach and that this release may be linked to nutritional status.

  20. Calmodulin as a downstream gene of octopamine-OAR α1 signalling mediates olfactory attraction in gregarious locusts.

    PubMed

    Xu, L; Li, L; Yang, P; Ma, Z

    2017-02-01

    The migratory locust (Locusta migratoria) shows aggregative traits in nymph marching bands and swarm formations through mutual olfactory attraction of conspecifics. However, olfactory preference in different nymph stages in gregarious locusts is not sufficiently explored. In this study, we found that the nymph olfactory preference for gregarious volatiles exhibited obvious variations at different developmental stages. The gregarious locusts show attractive response to conspecific volatiles from the third stadium. Transcriptome comparison between third- and fourth-stadium nymphs showed that the G protein-coupled receptor (GPCR) pathways are significantly enriched. Amongst the genes present in GPCR pathways, the expression level of calmodulin in locust brains significantly increased from the third- to the fourth-stadium nymphs. Amongst the four octopamine receptors (OARs) belonging to the GPCR family, only OAR α1 showed similar expression patterns to those of calmodulin, and knockdown of OAR α1 reduced the expression level of calmodulin. RNA interference of calmodulin decreased locomotion and induced the loss of olfactory attraction in gregarious locusts. Moreover, the activation of OAR α1 in calmodulin-knockdown locusts did not induce olfactory attraction of the nymphs to gregarious volatiles. Thus, calmodulin as a downstream gene of octopamine-OAR α1 (OA-OAR α1) signalling mediates olfactory attraction in gregarious locusts. Overall, this study provides novel insights into the mechanism of OA-OAR α1 signalling involved in olfactory attraction of gregarious locusts.

  1. Past locust outbreaks in the Czech Lands: do they indicate particular climatic patterns?

    NASA Astrophysics Data System (ADS)

    Brázdil, Rudolf; Řezníčková, Ladislava; Valášek, Hubert; Kiss, Andrea; Kotyza, Oldřich

    2014-04-01

    Outbreaks of locusts, probably Locusta migratoria, were once relatively frequent phenomena in Central Europe. Documentary evidence reaching back as far as the fourteenth century provides information about these events in the Czech Lands. The stages of morphological development of locusts are influenced by a number of natural conditions, including climate. The question remains as to the extent to which the occurrence of locusts may be attributed to particular weather/climatic patterns in a given year (period) in Central Europe. Available documentary sources recording locust outbreaks in the Czech Lands are presented. The chronology thus created shows their occurrence peaked in the seventeenth century, followed in severity by the eighteenth and sixteenth centuries. Some of the largest outbreaks recorded (1338, 1474-1475, 1542-1546, 1693, 1712 and 1748-1749) are analysed in detail. Seasonal temperature and precipitation patterns in Central Europe during the years in which the locust outbreaks took place show no particular climatic features compared with the years without them, with the exception of cooler and wetter springs and wetter summers.

  2. Sky Compass Orientation in Desert Locusts-Evidence from Field and Laboratory Studies.

    PubMed

    Homberg, Uwe

    2015-01-01

    Locusts are long-range migratory insects. At high population density, immature animals form marching hopper bands while adults take off and form huge swarms of millions of animals. At low population densities animals are solitarious, but likewise migrate, mostly during the night. Numerous studies aimed at predicting locust infestations showed that migrations both as hopper bands and as adults are largely downwind following seasonal shifts of the tropical convergence zone taking the animals to areas of rainfall. Only a few studies provided evidence for active orientation mechanisms, including the involvement of a sun compass. This scarcity of evidence stands in contrast to recent neurobiological data showing sophisticated neuronal adaptations suited for sky compass navigation. These include a special dorsal eye region with photoreceptors suited to analyze the polarization pattern of the sky and a system of topographically arranged sky compass neurons in the central complex of the brain. Laboratory experiments, moreover, demonstrated polarotaxis in tethered flying animals. The discrepancy of these findings call for more rigorous field studies on active orientation mechanisms in locusts. It remains to be shown how locusts use their internal sky compass during mass migrations and what role it plays to guide solitarious locusts in their natural habitat.

  3. Periodic temperature-associated drought/flood drives locust plagues in China.

    PubMed

    Zhang, Zhibin; Cazelles, Bernard; Tian, Huidong; Stige, Leif Christian; Bräuning, Achim; Stenseth, Nils Chr

    2009-03-07

    Global warming is currently of great concern. Yet the ecological effects of low-frequency climate variations remain largely unknown. Recent analyses of interdecadal variability in population abundance of the Oriental migratory locust (Locusta migratoria manilensis) in China have revealed negative associations with temperature and positive associations with Yangtze drought and flood frequencies during the past millennium (AD 957-1956). In order to shed new light on the causal relationships between locust abundance, floods, droughts and temperature in ancient China, we used wavelet analysis to explore how the coherencies between the different variables at different frequencies have been changed during the past millennium. We find consistent in-phase coherencies between locusts and drought/flood frequencies, and out-of-phase coherencies between locusts and temperature and between drought/flood and temperature at period components of 160-170 years. Similar results are obtained when historical data of drought/flood frequencies of the Yangtze Delta region are used, despite flood data showing a weak and somewhat inconsistent association with other factors. We suggest that previously unreported periodic cooling of 160-170-year intervals dominate climatic variability in China through the past millennium, the cooling events promoting locust plagues by enhancing temperature-associated drought/flood events. Our results signify a rare example of possible benign effects of global warming on the regional risk of natural disasters such as flood/drought events and outbreaks of pest insects.

  4. Periodic temperature-associated drought/flood drives locust plagues in China

    PubMed Central

    Zhang, Zhibin; Cazelles, Bernard; Tian, Huidong; Christian Stige, Leif; Bräuning, Achim; Stenseth, Nils Chr.

    2008-01-01

    Global warming is currently of great concern. Yet the ecological effects of low-frequency climate variations remain largely unknown. Recent analyses of interdecadal variability in population abundance of the Oriental migratory locust (Locusta migratoria manilensis) in China have revealed negative associations with temperature and positive associations with Yangtze drought and flood frequencies during the past millennium (AD 957–1956). In order to shed new light on the causal relationships between locust abundance, floods, droughts and temperature in ancient China, we used wavelet analysis to explore how the coherencies between the different variables at different frequencies have been changed during the past millennium. We find consistent in-phase coherencies between locusts and drought/flood frequencies, and out-of-phase coherencies between locusts and temperature and between drought/flood and temperature at period components of 160–170 years. Similar results are obtained when historical data of drought/flood frequencies of the Yangtze Delta region are used, despite flood data showing a weak and somewhat inconsistent association with other factors. We suggest that previously unreported periodic cooling of 160–170-year intervals dominate climatic variability in China through the past millennium, the cooling events promoting locust plagues by enhancing temperature-associated drought/flood events. Our results signify a rare example of possible benign effects of global warming on the regional risk of natural disasters such as flood/drought events and outbreaks of pest insects. PMID:19033144

  5. Effects of diet on the chemical composition of migratory locusts (Locusta migratoria).

    PubMed

    Oonincx, D G A B; van der Poel, A F B

    2011-01-01

    An experiment was conducted to determine the effects of diet on the chemical composition of migratory locusts (Locusta migratoria L.). Fresh and dry weight and the contents of dry matter, ash, lipid, protein, Ca, K, Mg, Na, P, Cu, Fe, Zn, retinol, lutein, zeaxanthine, cryptoxanthin, carotenes, lycopene and gross energy were determined in penultimate instar and adult locusts, that had been fed three different diets. The locusts received a diet of grass or grass+wheat bran or grass+wheat bran+carrots. Adding wheat bran decreased the protein content and increased fat content (633 vs. 583 and 182 vs. 231 g/kg DM, respectively). Addition of carrots to the diet increased fat content further from 231 to 271 g/kg DM. Mineral concentrations of Ca, K, Mg, and Na, were significantly affected by diet. P, K, Cu, and Fe concentrations were significantly different in penultimate migratory locusts compared with adults. Wheat bran decreased the α-carotene content, which did not change by incorporating carrots in the diet. However, carrots did result in higher β-carotene concentrations. Retinol concentrations were increased by incorporating both wheat bran and carrots in the diet compared with the diet containing only grass. This study shows that the chemical composition of migratory locusts can be manipulated through the diet. As such, it enables nutritionists to adapt the chemical composition of live feeder insects to better meet the nutritional demands of predators.

  6. Control of ovarian steroidogenesis in insects: a locust neurohormone is active in vitro on blowfly ovaries.

    PubMed

    Manière, G; Vanhems, E; Rondot, I; Delbecque, J P

    2009-09-15

    Ovarian steroidogenesis controlling insect reproduction is mainly regulated by brain gonadotropins liberated from corpora cardiaca (CC). Till now, different neurohormones have been identified in two insect groups only, locusts and mosquitoes, and it is unknown whether they could be active in other insects. In order to complete previous observations on the control of ovarian steroidogenesis in the blowfly, Phormia regina, we examined whether neuropeptides isolated from locust CC have an effect in vitro on ovarian steroidogenesis in our dipteran model. Our experiments showed that crude extracts from locust CC efficiently stimulated steroidogenesis in blowfly isolated previtellogenic ovaries. However, such an activity was observed neither with authenticated neuroparsins (NPs), the putative homologs of the ovarian ecdysteroidogenic hormone of mosquitoes, nor with ovarian maturing peptide (OMP), the putative locust steroidogenic neurohormone. Partial purifications of CC extracts were then performed using methanol and/or acidic ethanol extractions followed by reverse phase HPLC and collected fractions were assayed in vitro. A significant steroidogenic activity was found in a single group of acidic fractions, well separated from OMP and NPs, which was associated to slight but significant anti-insulin immunoreactivity. In conclusion, a locust CC neurohormone, different from NPs and OMP, is able to stimulate ecdysteroidogenesis in blowfly ovaries. Though this active factor has not been fully characterized, its behavior during extraction or HPLC and its immunoreactivity strongly suggest it could be an insulin-like peptide. This is in agreement with previous studies demonstrating the role of such peptides as steroidogenic gonadotropins in blowflies and several other insects.

  7. Metabolomic analysis reveals that carnitines are key regulatory metabolites in phase transition of the locusts.

    PubMed

    Wu, Rui; Wu, Zeming; Wang, Xianhui; Yang, Pengcheng; Yu, Dan; Zhao, Chunxia; Xu, Guowang; Kang, Le

    2012-02-28

    Phenotypic plasticity occurs prevalently and plays a vital role in adaptive evolution. However, the underlying molecular mechanisms responsible for the expression of alternate phenotypes remain unknown. Here, a density-dependent phase polyphenism of Locusta migratoria was used as the study model to identify key signaling molecules regulating the expression of phenotypic plasticity. Metabolomic analysis, using high-performance liquid chromatography and gas chromatography-mass spectrometry, showed that solitarious and gregarious locusts have distinct metabolic profiles in hemolymph. A total of 319 metabolites, many of which are involved in lipid metabolism, differed significantly in concentration between the phases. In addition, the time course of changes in the metabolic profiles of locust hemolymph that accompany phase transition was analyzed. Carnitine and its acyl derivatives, which are involved in the lipid β-oxidation process, were identified as key differential metabolites that display robust correlation with the time courses of phase transition. RNAi silencing of two key enzymes from the carnitine system, carnitine acetyltransferase and palmitoyltransferase, resulted in a behavioral transition from the gregarious to solitarious phase and the corresponding changes of metabolic profiles. In contrast, the injection of exogenous acetylcarnitine promoted the acquisition of gregarious behavior in solitarious locusts. These results suggest that carnitines mediate locust phase transition possibly through modulating lipid metabolism and influencing the nervous system of the locusts.

  8. Identification of a chitinase-producing bacterium C4 and histopathologic study on locusts.

    PubMed

    Yong, Tao; Zhangfu, Long; Jing, Xie; Hong, Jin; Hongyan, Ran; Ke, Tao; Shaorong, Ge; Kun, Liu; Shigui, Liu

    2005-02-01

    In order to develop the potential of chitinase-producing micro-organisms as biocontrol agents for insect pests, five chitinase-producing bacterial strains (C1, C2, C3, C4 and C5) previously isolated from soil samples were chosen to infect grassland locusts. The data showed that the mortality rate of locusts fed with strain C4 was significantly higher than that of other groups, and its pathogenicity was confirmed by Koch's law. Midgut tissues of locusts infected with C4 were examined with a light microscope. Apparent histopathologic changes in midgut cells partly explained the pathogenesis of locusts. Therefore, strain C4 was considered to be a potential biocontrol agent. To determine the taxonomic position of C4, physiological and biochemical characteristics were determined and molecular identification was performed. The 16S rDNA gene of C4 was amplified, cloned and sequenced. Comparative sequence analysis demonstrated that C4 corresponded to the genera Sanguibacter, Oerskovia and Cellulomonas. On the basis of phenotypic characterization and sequence similarity analysis, strain C4 was more closely related to the genus Sanguibacter. This chitinase-producing strain C4, which closely corresponds to the species of the genus Sanguibacter and is pathogenic to locusts, is here reported for the first time.

  9. Developmental- and food-dependent foraging transcript levels in the desert locust.

    PubMed

    Tobback, Julie; Verlinden, Heleen; Vuerinckx, Kristel; Vleugels, Rut; Vanden Broeck, Jozef; Huybrechts, Roger

    2013-12-01

    Drastic changes in the environment during a lifetime require developmental and physiological flexibility to ensure animal survival. Desert locusts, Schistocerca gregaria, live in an extremely changeable environment, which alternates between periods of rainfall and abundant food and periods of drought and starvation. In order to survive, locusts display an extreme form of phenotypic plasticity that allows them to rapidly cope with these changing conditions by converting from a cryptic solitarious phase to a swarming, voracious gregarious phase. To accomplish this, locusts possess different conserved mediators of phenotypic plasticity. Recently, attention has been drawn to the possible roles of protein kinases in this process. In addition to cyclic AMP-dependent protein kinase (PKA), also cyclic GMP-dependent protein kinase (PKG), which was shown to be involved in changes of food-related behavior in a variety of insects, has been associated with locust phenotypic plasticity. In this article, we study the transcript levels of the S. gregaria orthologue of the foraging gene that encodes a PKG in different food-related, developmental and crowding conditions. Transcript levels of the S. gregaria foraging orthologue are highest in different parts of the gut and differ between isolated and crowd-reared locusts. They change when the availability of food is altered, display a distinct pattern with higher levels after a moult and decrease with age during postembryonic development.

  10. Functional characterization of the short neuropeptide F receptor in the desert locust, Schistocerca gregaria.

    PubMed

    Dillen, Senne; Zels, Sven; Verlinden, Heleen; Spit, Jornt; Van Wielendaele, Pieter; Vanden Broeck, Jozef

    2013-01-01

    Whereas short neuropeptide F (sNPF) has already been reported to stimulate feeding behaviour in a variety of insect species, the opposite effect was observed in the desert locust. In the present study, we cloned a G protein-coupled receptor (GPCR) cDNA from the desert locust, Schistocerca gregaria. Cell-based functional analysis of this receptor indicated that it is activated by both known isoforms of Schgr-sNPF in a concentration dependent manner, with EC(50) values in the nanomolar range. This Schgr-sNPF receptor constitutes the first functionally characterized peptide GPCR in locusts. The in vivo effects of the sNPF signalling pathway on the regulation of feeding in locusts were further studied by knocking down the newly identified Schgr-sNPF receptor by means of RNA interference, as well as by means of peptide injection studies. While injection of sNPF caused an inhibitory effect on food uptake in the desert locust, knocking down the corresponding peptide receptor resulted in an increase of total food uptake when compared to control animals. This is the first comprehensive study in which a clearly negative correlation is described between the sNPF signalling pathway and feeding, prompting a reconsideration of the diverse roles of sNPFs in the physiology of insects.

  11. Transforming giants.

    PubMed

    Kanter, Rosabeth Moss

    2008-01-01

    Large corporations have long been seen as lumbering, inflexible, bureaucratic--and clueless about global developments. But recently some multinationals seem to be transforming themselves: They're engaging employees, moving quickly, and introducing innovations that show true connection with the world. Harvard Business School's Kanter ventured with a research team inside a dozen global giants--including IBM, Procter & Gamble, Omron, CEMEX, Cisco, and Banco Real--to discover what has been driving the change. After conducting more than 350 interviews on five continents, she and her colleagues came away with a strong sense that we are witnessing the dawn of a new model of corporate power: The coordination of actions and decisions on the front lines now appears to stem from widely shared values and a sturdy platform of common processes and technology, not from top-down decrees. In particular, the values that engage the passions of far-flung workforces stress openness, inclusion, and making the world a better place. Through this shift in what might be called their guidance systems, the companies have become as creative and nimble as much smaller ones, even while taking on social and environmental challenges of a scale that only large enterprises could attempt. IBM, for instance, has created a nonprofit partnership, World Community Grid, through which any organization or individual can donate unused computing power to research projects and see what is being done with the donation in real time. IBM has gained an inspiring showcase for its new technology, helped business partners connect with the company in a positive way, and offered individuals all over the globe the chance to contribute to something big.

  12. Giant Cell Arteritis

    MedlinePlus

    Giant cell arteritis is a disorder that causes inflammation of your arteries, usually in the scalp, neck, and arms. ... arteries, which keeps blood from flowing well. Giant cell arteritis often occurs with another disorder called polymyalgia ...

  13. Inhalable Antitubercular Therapy Mediated by Locust Bean Gum Microparticles.

    PubMed

    Alves, Ana D; Cavaco, Joana S; Guerreiro, Filipa; Lourenço, João P; Rosa da Costa, Ana M; Grenha, Ana

    2016-05-28

    Tuberculosis remains a major global health problem and alternative therapeutic approaches are needed. Considering the high prevalence of lung tuberculosis (80% of cases), the pulmonary delivery of antitubercular drugs in a carrier system capable of reaching the alveoli, being recognised and phagocytosed by alveolar macrophages (mycobacterium hosts), would be a significant improvement to current oral drug regimens. Locust bean gum (LBG) is a polysaccharide composed of galactose and mannose residues, which may favour specific recognition by macrophages and potentiate phagocytosis. LBG microparticles produced by spray-drying are reported herein for the first time, incorporating either isoniazid or rifabutin, first-line antitubercular drugs (association efficiencies >82%). Microparticles have adequate theoretical properties for deep lung delivery (aerodynamic diameters between 1.15 and 1.67 μm). The cytotoxic evaluation in lung epithelial cells (A549 cells) and macrophages (THP-1 cells) revealed a toxic effect from rifabutin-loaded microparticles at the highest concentrations, but we may consider that these were very high comparing with in vivo conditions. LBG microparticles further evidenced strong ability to be captured by macrophages (percentage of phagocytosis >94%). Overall, the obtained data indicated the potential of the proposed system for tuberculosis therapy.

  14. The effect of octopamine on the locust stomatogastric nervous system.

    PubMed

    Rand, David; Knebel, Daniel; Ayali, Amir

    2012-01-01

    Octopamine (OA) is a prominent neuromodulator of invertebrate nervous systems, influencing multiple physiological processes. Among its many roles in insects are the initiation and maintenance of various rhythmic behaviors. Here, the neuromodulatory effects of OA on the components of the locust stomatogastric nervous system were studied, and one putative source of OA modulation of the system was identified. Bath application of OA was found to abolish the endogenous rhythmic output of the fully isolated frontal ganglion (FG), while stimulating motor activity of the fully isolated hypocerebral ganglion (HG). OA also induced rhythmic movements in a foregut preparation with intact HG innervation. Complex dose-dependent effects of OA on interconnected FG-HG preparations were seen: 10(-5) M OA accelerated the rhythmic activity of both the HG and FG in a synchronized manner, while 10(-4) M OA decreased both rhythms. Intracellular stimulation of an identified octopaminergic dorsal unpaired median neuron in the subesophageal ganglion was found to exert a similar effect on the FG motor output as that of OA application. Our findings suggest a mechanism of regulation of insect gut patterns and feeding-related behavior during stress and times of high energy demand.

  15. Purification and characterization of arginine kinase from locust.

    PubMed

    Li, Miao; Wang, Xiao-Yun; Bai, Ji-Gang

    2006-01-01

    L-Arginine kinase (AK; ATP:L-arginine N-phosphotransferase; EC 2.7.3.3) catalyzes the reversible transphosphorylation between N-phospho-L-arginine (PArg) and ATP thus buffering cellular ATP levels. AK was purified from the leg muscle of the locust Migratoria manilensis by Sephacryl S-200 HR gel filtration chromatography and DEAE Sepharose CL-6B fast flow anion exchange chromatography to an apparent homogeneity with a recovery of 80%. The enzyme behaved as monomeric protein with molecular mass of about 40 kD, and had a pH and temperature optimum of 8.6 and 30 degrees C, respectively, and a pI of about 6.3. The Michaelis constants for synthesis of PArg are 0.936 and 1.290 mM for L-arginine and ATP, respectively and k(cat)/K(m)(Arg) 174. The activity of AK required divalent cations such as Mg(2+) and Mn(2+). In the presence of Cu(2+) and Zn(2+), AK activity was greatly inhibited. The intrinsic protein fluorescence emission maximum at 330 nm using the excitation wavelength at 295 nm suggested that tryptophan residues are below the surface of the protein and not exposed to solvent.

  16. Geographic variation in RNAi sensitivity in the migratory locust.

    PubMed

    Sugahara, Ryohei; Tanaka, Seiji; Jouraku, Akiya; Shiotsuki, Takahiro

    2017-03-20

    The RNA interference (RNAi) technology has been widely used in basic and applied research. It is known that RNAi works in some species but not in others, although the cause for this difference remains unclear. Here, we present inter- and intra-populational variations in RNAi sensitivity in the migratory locust Locusta migratoria, and provide information on the genetic background of such variations. In the four strains analyzed, originating from different Japanese localities, most individuals from two of the strains were sensitive to injections of double-stranded RNA (dsRNA) against the corazonin (CRZ) and ecdysone receptor genes, whereas those from the other two strains were resistant. Selection for individuals sensitive to dsCRZ produced a dramatic increase in the RNAi sensitivity in the following generations, although phenotypes also varied in the selected line, suggesting that several genes might control RNAi sensitivity. Reciprocal crosses between a sensitive and a resistant strain suggested that the resistant phenotype is dominant. The expression levels of nine RNAi-associated genes known for other organisms were not correlated with the variation in RNAi sensitivity observed in L. migratoria. Variations in RNAi sensitivity as the ones observed in this study should be considered when using RNAi in basic and applied research as well as in pest management.

  17. Identification of pheromone-like compounds in male reproductive organs of the oriental locust Locusta migratoria.

    PubMed

    Ban, Liping; Napolitano, Elio; Serra, Andrea; Zhou, Xianhong; Iovinella, Immacolata; Pelosi, Paolo

    2013-08-09

    Despite the great economical interest of locusts in agriculture, knowledge on their chemoreception systems is still poor. Phenylacetonitrile is recognised as a pheromone of the desert locust Schistocerca gregaria, triggering gregarization, promoting aggregation and inhibiting courtship. However, in the other major locust species, Locusta migratoria, pheromones have not been reported. We have identified the two isomers of naphthylpropionitrile from the male reproductive organs of L. migratoria. Chemical synthesis has confirmed the identity of the two compounds. Both isomers show significant affinity to CSP91, a protein reported in the testis, but not to three other proteins of the same family (CSP180, CSP540 and CSP884) expressed in female accessory glands. The striking similarity of these compounds with phenylacetonitrile and the unusual nature of such chemicals strongly suggest that naphthylpropionitrile could be pheromones for L. migratoria, while their site of expression and binding activity indicate a role in communication between sexes.

  18. AN ODORANT-BINDING PROTEIN INVOLVED IN PERCEPTION OF HOST PLANT ODORANTS IN LOCUST Locusta migratoria.

    PubMed

    Li, Jia; Zhang, Long; Wang, Xiaoqi

    2016-04-01

    Locusts, Locusta migratoria (Orthoptera: Acrididae), are extremely destructive agricultural pests, but very little is known of their molecular aspects of perception to host plant odorants including related odorant-binding proteins (OBPs), though several OBPs have been identified in locust. To elucidate the function of LmigOBP1, the first OBP identified from locust, RNA interference was employed in this study to silence LmigOBP1, which was achieved by injection of dsRNA targeting LmigOBP1 into the hemolymph of male nymphs. Compared with LmigOBP1 normal nymphs, LmigOBP1 knockdown nymphs significantly decreased food (maize leaf, Zea mays) consumption and electro-antennography responses to five maize leaf volatiles, ((Z)-3-hexenol, linalool, nonanal, decanal, and (Z)-3-hexenyl acetate). These suggest that LmigOBP1 is involved in perception of host plant odorants.

  19. Monitoring grasshopper and locust habitats in Sahelian Africa using GIS and remote sensing technology

    USGS Publications Warehouse

    Tappan, G. Gray; Moore, Donald G.; Knauseberger, Walter I.

    1991-01-01

    Development programmes in Sahelian Africa are beginning to use geographic information system (GIS) technology. One of the GIS and remote sensing programmes introduced to the region in the late 1980s was the use of seasonal vegetation maps made from satellite data to support grasshopper and locust control. Following serious outbreaks of these pests in 1987, the programme addressed a critical need, by national and international crop protection organizations, to monitor site-specific dynamic vegetation conditions associated with grasshopper and locust breeding. The primary products used in assessing vegetation conditions were vegetation index (greenness) image maps derived from National Oceanic and Atmospheric Administration satellite imagery. Vegetation index data were integrated in a GIS with digital cartographic data of individual Sahelian countries. These near-real-time image maps were used regularly in 10 countries for locating potential grasshopper and locust habitats. The programme to monitor vegetation conditions is currently being institutionalized in the Sahel.

  20. Microwave assisted synthesis of acrylamide grafted locust bean gum and its application in drug delivery.

    PubMed

    Kaity, Santanu; Isaac, Jinu; Kumar, P Mahesh; Bose, Anirbandeep; Wong, Tin Wui; Ghosh, Animesh

    2013-10-15

    Acrylamide grafted copolymer of locust bean gum was prepared by microwave irradiation using ceric ammonium nitrate as redox initiator. The grafting process was optimized in terms of irradiation time, amount of initiator and acrylamide by using constant amount of native locust bean gum. The grafted gum was characterized by Fourier transform infrared spectroscopy (FT-IR), (13)C nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), X-ray diffraction study (XRD), differential scanning calorimetry (DSC), elemental analysis, contact angle, viscosity, molecular weight, swelling and biodegradability studies. The grafted gum was found to be biodegradable and non-toxic. It was further used to prepare controlled-release matrix tablet of buflomedil hydrochloride. The in vitro release profile of the tablet showed the rate controlling property of acrylamide grafted locust bean gum was similar to that of hydroxypropyl methylcellulose (HPMC-K15M).

  1. Giant impacts on giant planets

    NASA Astrophysics Data System (ADS)

    de Pater, Imke

    2013-10-01

    The 2009 impact and recent superbolides on Jupiter caught the world by surprise and cast doubt on impactor flux estimates for the outer solar system. Enhanced amateur planetary imaging techniques yield both high spatial resolution {enabling the 2009 impact debris field detection} and rapid frame rates {enabling the 2010/2012 impact flash detections and lightcurve measurements}.We propose a ToO program to image future impacts on Jupiter and Saturn. To remove the possibility of impact cloud non-detections, the program will be triggered only if an existing impact debris field is seen, an object on a collision course with Jupiter or Saturn is discovered, or an impact light curve is measured with an estimated total energy large enough to generate an impact cloud in a giant planet atmosphere {10^20 J}.HST provides the only way to image these events in the ultraviolet, providing information on aerosol altitudes and on smaller particles that are less visible to ground-based infrared observations. High-resolution imaging with proper timing {not achievable from the ground} is required to measure precisely both the velocity fields of impact sites and the optical spectrum of impact debris. HST observations of past impacts on Jupiter have also served both as cornerstones of science investigations at other wavelengths and as vehicles for effective public outreach.Large outer solar system impacts are governed by the same physics as in the terrestrial events that dominate the impact threat to humans. Studying the behavior of impactors of various sizes and compositions, as they enter the atmosphere at varying angles and speeds, will better quantify terrestrial impact hazards.

  2. Giant impacts on giant planets

    NASA Astrophysics Data System (ADS)

    de Pater, Imke

    2014-10-01

    The 2009 impact and recent superbolides on Jupiter caught the world by surprise and cast doubt on impactor flux estimates for the outer solar system. Enhanced amateur planetary imaging techniques yield both high spatial resolution (enabling the 2009 impact debris field detection) and rapid frame rates (enabling the 2010/2012 impact flash detections and lightcurve measurements).We propose a ToO program to image future impacts on Jupiter and Saturn. To remove the possibility of impact cloud non-detections, the program will be triggered only if an existing impact debris field is seen, an object on a collision course with Jupiter or Saturn is discovered, or an impact light curve is measured with an estimated total energy large enough to generate an impact cloud in a giant planet atmosphere (10^20 J).HST provides the only way to image these events in the ultraviolet, providing information on aerosol altitudes and on smaller particles that are less visible to ground-based infrared observations. High-resolution imaging with proper timing (not achievable from the ground) is required to measure precisely both the velocity fields of impact sites and the optical spectrum of impact debris. HST observations of past impacts on Jupiter have also served both as cornerstones of science investigations at other wavelengths and as vehicles for effective public outreach.Large outer solar system impacts are governed by the same physics as in the terrestrial events that dominate the impact threat to humans. Studying the behavior of impactors of various sizes and compositions, as they enter the atmosphere at varying angles and speeds, will better quantify terrestrial impact hazards.

  3. Giant impacts on giant planets

    NASA Astrophysics Data System (ADS)

    de Pater, Imke

    2012-10-01

    The 2009 impact on Jupiter caught the world by surprise and cast doubt on impactor flux estimates for the outer solar system. Enhanced amateur planetary imaging techniques yield both high spatial resolution {enabling the 2009 impact debris field detection} and rapid frame rates {enabling the 2010 impact flash detections and lightcurve measurements}.We propose a Target of Opportunity program to image future impacts on Jupiter and Saturn. To remove the possibility of impact cloud non-detections, the program will be triggered only if an existing impact debris field is seen, an object on a collision course with Jupiter or Saturn is discovered, or an impact light curve is measured with an estimated total energy large enough to generate an impact cloud in a giant planet atmosphere.HST provides the only way to image these events in the ultraviolet, providing information on aerosol altitudes and on smaller particles that are less visible to ground-based infrared observations. High-resolution imaging with proper timing {not achievable from the ground} is required to measure precisely both the velocity fields of impact sites and the optical spectrum of impact debris. HST observations of past impacts on Jupiter have also served both as cornerstones of science investigations at other wavelengths and as vehicles for effective public outreach.Large outer solar system impacts are governed by the same physics as in the terrestrial events that dominate the impact threat to humans. Studying the behavior of impactors of various sizes and compositions, as they enter the atmosphere at varying angles and speeds, will better quantify terrestrial impact hazards.

  4. Relationship between oriental migratory locust plague and soil moisture extracted from MODIS data

    NASA Astrophysics Data System (ADS)

    Liu, Zhenbo; Shi, Xuezheng; Warner, Eric; Ge, Yunjian; Yu, Dongsheng; Ni, Shaoxiang; Wang, Hongjie

    2008-02-01

    Locust plagues have been the source of some of the most severe natural disasters in human history. Soil moisture content is among the most important of the numerous factors influencing plague onset and severity. This paper describes a study initiated in three pilot locust plague monitoring regions, i.e., Huangzao, Yangguanzhuang, and Tengnan in Huanghua county, Hebei province, China, to examine the impact of soil moisture status on oriental migratory locust [ Locusta migratoria manilensis (L.) Meyen] plague breakout as related to the life cycle, oviposition in autumn, survival in winter, and incubation in summer. Thirty-nine temperature vegetation dryness index (TVDI) data sets, which represent soil moisture content, were extracted from MODIS remote sensing images for two representative time periods: a severe locust plague breakout year (2001-2002) and a slight plague year (2003-2004). TVDI values demonstrated distinctive soil moisture status differences between the 2 years concerned. Soil moisture conditions in the severe plague year were shown to be lower than those in slight plague year. In all three pilot regions, average TVDI value in the severe plague year was 0.07 higher than that in slight plague year, and monthly TVDI values in locust oviposition period (September and October) and incubation period (March, April and May) were higher than their corresponding monthly figures in slight plague year. No remarkable TVDI differences were found in other months during the locust life cycle between the 2 years. TVDI values for September and October (2001), March, April and May (2002) were 0.11, 0.08, 0.16, 0.11 and 0.16 higher than their corresponding monthly figures in 2003-2004 period, respectively.

  5. Anoxic stress and rapid cold hardening enhance cold tolerance of the migratory locust.

    PubMed

    Cui, Feng; Wang, Hongsheng; Zhang, Hanying; Kang, Le

    2014-10-01

    Anoxia and rapid cold hardening (RCH) can increase the cold tolerance of many animals. However, mechanisms underlying these two kinds of stresses remain unclear. In this study, we aimed to explore the relationship of acclimation to cold stress with acclimation to anoxic stress in the migratory locust, Locusta migratoria. RCH at 0°C for 3h promoted the survival of cold stress-exposed locusts. Anoxic hypercapnia (CO2 anoxic treatment) for 40 min exerted an effect similar to that of RCH. Anoxic hypercapnia within 1h can all promote the cold hardiness of locusts. We investigated the transcript levels of six heat shock protein (Hsp) genes, namely, Hsp20.5, Hsp20.6, Hsp20.7, Hsp40, Hsp70, and Hsp90. Four genes, namely, Hsp90, Hsp40, Hsp20.5, and Hsp20.7, showed differential responses to RCH and anoxic hypercapnia treatments. Under cold stress, locusts exposed to the two regimens showed different responses for Hsp90, Hsp20.5, and Hsp20.7. However, the varied responses disappeared after recovery from cold stress. Compared with the control group, the transcript levels of six Hsp genes were generally downregulated in locusts subjected to anoxic hypercapnia or/and RCH. These results indicate that anoxic stress and RCH have different mechanisms of regulating the transcription of Hsp family members even if the two treatments exerted similar effects on cold tolerance of the migratory locust. However, Hsps may not play a major role in the promotion of cold hardiness by the two treatments.

  6. Locust displacing winds in eastern Australia reassessed with observations from an insect monitoring radar

    NASA Astrophysics Data System (ADS)

    Hao, Zhenhua; Drake, V. Alistair; Sidhu, Leesa; Taylor, John R.

    2017-07-01

    Based on previous investigations, adult Australian plague locusts are believed to migrate on warm nights (with evening temperatures >25 °C), provided daytime flight is suppressed by surface winds greater than the locusts' flight speed, which has been shown to be 3.1 m s-1. Moreover, adult locusts are believed to undertake briefer `dispersal' flights on nights with evening temperature >20 °C. To reassess the utility of these conditions for forecasting locust flight, contingency tests were conducted comparing the nights selected on these bases (predicted nights) for the months of November, January, and March and the nights when locust migration were detected with an insect monitoring radar (actual nights) over a 7-year period. In addition, the wind direction distributions and mean wind directions on all predicted nights and actual nights were compared. Observations at around 395 m above ground level (AGL), the height at which radar observations have shown that the greatest number of locusts fly, were used to determine the actual nights. Tests and comparisons were also made for a second height, 990 m AGL, as this was used in the previous investigation. Our analysis shows that the proposed criteria are successful from predicting migratory flight only in March, when the surface temperature is effective as a predicting factor. Surface wind speed has no predicting power. It is suggested that a strong daytime surface wind speed requirement should not be considered and other meteorological variables need to be added to the requirement of a warm surface temperature around dusk for the predictions to have much utility.

  7. Onset of collective motion in locusts is captured by a minimal model

    NASA Astrophysics Data System (ADS)

    Dyson, Louise; Yates, Christian A.; Buhl, Jerome; McKane, Alan J.

    2015-11-01

    We present a minimal model to describe the onset of collective motion seen when a population of locusts are placed in an annular arena. At low densities motion is disordered, while at high densities locusts march in a common direction, which may reverse during the experiment. The data are well captured by an individual-based model, in which demographic noise leads to the observed density-dependent effects. By fitting the model parameters to equation-free coefficients, we give a quantitative comparison, showing time series, stationary distributions, and the mean switching times between states.

  8. Optimizing energy yields in black locust through genetic selection: final report

    SciTech Connect

    Bongarten, B.C.; Merkle, S.A.

    1996-10-01

    The purpose of this work was to assess the magnitude of improvement in biomass yield of black locust possible through breeding, and to determine methods for efficiently capturing the yield improvement achievable from selective breeding. To meet this overall objective, six tasks were undertaken to determine: (1) the amount and geographic pattern of natural genetic variation, (2) the mating system of the species, (3) quantitative genetic parameters of relevant traits, (4) the relationship between nitrogen fixation and growth in black locust, (5) the viability of mass vegetative propagation, and (6) the feasibility of improvement through genetic transformation.

  9. Alteration of bursting properties in interneurons during locust flight.

    PubMed

    Ramirez, J M; Pearson, K G

    1993-11-01

    1. The contribution of bursting properties to the generation of the flight motor pattern was examined for two identified interneurons (interneurons 566 and 567) in the flight system of the locust Locusta migratoria by means of intracellular recording and stimulation techniques. These interneurons are important elements in transmitting proprioceptive information from the hindwing tegula to wing elevator motoneurons. 2. Offset currents injected into these neurons revealed that bursts are triggered in the intact flying animal by synaptic input from tegula afferents (n = 10). These bursts lead to an amplification of proprioceptive input that is crucial for the generation of the intact flight motor pattern. In the absence of afferent input the activity of these neurons remained subthreshold for triggering a burst. This explains why these neurons exhibit only weak rhythmic oscillations in deafferented animals. 3. The property of interneuron 566 to burst was conditional, always being expressed during flight (n = 14) and occurring only occasionally in the quiescent animal. In the absence of flight, stimulation of tegula afferents never evoked bursts in interneuron 566 (n = 7) and depolarizing current pulses evoked weak bursts in only three of nine preparations. In 2 of 14 animals, bursting property of interneuron 566 was enhanced just after the termination of flight. 4. Variability in the bursting property was also found for interneuron 567. In the quiescent animal, tegula-evoked compound excitatory postsynaptic potentials were not sufficient to trigger bursts (n = 3) but depolarizing current pulses evoked always weak rhythmic bursting activity (n = 4). This bursting property was also variable and in one animal we found long-lasting plateau potentials that could be evoked by current injection after flight was elicited several times. 5. The data presented demonstrate that the capacity to burst is conditional in the interneurons 566 and 567. Bursting properties are always

  10. Identification of representative genes of the central nervous system of the locust, Locusta migratoria manilensis by deep sequencing.

    PubMed

    Zhang, Zhengyi; Peng, Zhi-Yu; Yi, Kang; Cheng, Yanbing; Xia, Yuxian

    2012-01-01

    The shortage of available genomic and transcriptomic data hampers the molecular study on the migratory locust, Locusta migratoria manilensis (L.) (Orthoptera: Acrididae) central nervous system (CNS). In this study, locust CNS RNA was sequenced by deep sequencing. 41,179 unigenes were obtained with an average length of 570 bp, and 5,519 unigenes were longer than 1,000 bp. Compared with an EST database of another locust species Schistocerca gregaria Forsskåi, 9,069 unigenes were found conserved, while 32,110 unigenes were differentially expressed. A total of 15,895 unigenes were identified, including 644 nervous system relevant unigenes. Among the 25,284 unknown unigenes, 9,482 were found to be specific to the CNS by filtering out the previous ESTs acquired from locust organs without CNS's. The locust CNS showed the most matches (18%) with Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) sequences. Comprehensive assessment reveals that the database generated in this study is broadly representative of the CNS of adult locust, providing comprehensive gene information at the transcriptional level that could facilitate research of the locust CNS, including various physiological aspects and pesticide target finding.

  11. Behavior of geladas and other endemic wildlife during a desert locust outbreak at Guassa, Ethiopia: ecological and conservation implications.

    PubMed

    Fashing, Peter J; Nguyen, Nga; Fashing, Norman J

    2010-07-01

    Desert locust (Schistocerca gregaria) outbreaks have occurred repeatedly throughout recorded history in the Horn of Africa region, devastating crops and contributing to famines. In June 2009, a desert locust swarm invaded the Guassa Plateau, Ethiopia, a large and unusually intact Afroalpine tall-grass ecosystem, home to important populations of geladas (Theropithecus gelada), Ethiopian wolves (Canis simensis), thick-billed ravens (Corvus crassirostris), and other Ethiopian or Horn of Africa endemics. During the outbreak and its aftermath, we observed many animals, including geladas, ravens, and a wolf, feeding on locusts in large quantities. These observations suggest surprising flexibility in the normally highly specialized diets of geladas and wolves, including the potential for temporary but intensive insectivory during locust outbreaks. To our knowledge, Guassa is the highest elevation site (3,200-3,600 m) at which desert locusts, which require temperatures >20 degrees C for sustained flight, have been reported. Continued monitoring will be necessary to determine whether the June 2009 outbreak was an isolated incident or part of an emerging pattern in the Ethiopian Highlands linked to global warming. The intensive consumption of desert locusts by geladas, wolves, and ravens during the outbreak at Guassa raises concerns about pesticide-based locust control strategies and potential unintended adverse effects on endemic and endangered wildlife.

  12. CSP and Takeout Genes Modulate the Switch between Attraction and Repulsion during Behavioral Phase Change in the Migratory Locust

    PubMed Central

    Ma, Zongyuan; Xue, Liang; Han, Jingyao; Yu, Dan; Kang, Le

    2011-01-01

    Behavioral plasticity is the most striking trait in locust phase transition. However, the genetic basis for behavioral plasticity in locusts is largely unknown. To unravel the molecular mechanisms underlying the behavioral phase change in the migratory locust Locusta migratoria, the gene expression patterns over the time courses of solitarization and gregarization were compared by oligonucleotide microarray analysis. Data analysis revealed that several gene categories relevant to peripheral olfactory perception are strongly regulated in a total of 1,444 differentially expressed genes during both time courses. Among these candidate genes, several CSP (chemosensory protein) genes and one takeout gene, LmigTO1, showed higher expression in gregarious and solitarious locusts, respectively, and displayed opposite expression trends during solitarization and gregarization. qRT-PCR experiments revealed that most CSP members and LmigTO1 exhibited antenna-rich expressions. RNA interference combined with olfactory behavioral experiments confirmed that the CSP gene family and one takeout gene, LmigTO1, are involved in the shift from repulsion to attraction between individuals during gregarization and in the reverse transition during solitarization. These findings suggest that the response to locust-emitted olfactory cues regulated by CSP and takeout genes is involved in the behavioral phase change in the migratory locust and provide a previously undescribed molecular mechanism linked to the formation of locust aggregations. PMID:21304893

  13. Application of sugar maple and black locust to the biomass/energy plantation concept. Interim report, March 1, 1980-February 28, 1981. [Sugar Maples, Black Locusts

    SciTech Connect

    Not Available

    1981-03-01

    The objective of the research program is to determine the feasibility of converting existing pole-size maple stands to biomass/energy plantations using black locust as an interplanted species. Toward this end, progress has been made in quantifying sprout biomass. Significant differences have been identified in productivity by site, species, time of fertilizer application, and diameter and damage of stumps. Rhizobium strains for black locust have been identified which are tolerant of low pH and phosphorous and high aluminum levels. Frost-hardy black locust seed sources have been identified for future work. Methods for sampling and equations for young natural stands of maple have been developed. Detailed characterization of sugar and red maple sprouts by physical, chemical and thermal analysis were compared to those of old, mature trees. The results are discussed in terms of seasonal moisture content variation, effects of tree age on specific gravity, extractive contents, ash content, major cell wall components, heating values and thermal behavior. 7 references, 5 figures, 17 tables.

  14. The Electric Giant Resonances

    NASA Astrophysics Data System (ADS)

    van der Woude, A.

    The following sections are included: * Introduction * Experimental Methods to Study Giant Resonances * Introduction * The Tools * Introduction * Tools for Isoscalar Scattering * INELASTIC α-SCATTERING * INELASTIC PROTON SCATTERING * Tools for Isovector Excitations * γ-ABSORPTION AND PARTICLE CAPTURE REACTIONS * CHARGE EXCHANGE REACTIONS - THE (π+, π0) REACTION * Tools For Isoscalar And Isovector Excitations * INELASTIC ELECTRON SCATTERING * GIANT RESONANCE EXCITATION BY FAST HEAVY IONS * From Multipole Cross Section To Multipole Strength * The Electric Isoscalar Resonances * The Isoscalar Giant Monopole Resonance * Systematics on the GMR * Compressibility and the Giant Monopole Resonance * Introduction * The Compressibility of nuclear matter from the GMR energies * Discussion * The Isoscalar Giant Quadrupole Resonance * General Trends In Medium-Heavy and Heavy Nuclei * The GQR In Light Nuclei * The Isoscalar 3- Strength, LEOR and HEOR * Isoscalar 4+ Strength * Miscellaneous; Isoscalar 1- and L > 4-Strength * The Electric Isovector Giant Resonances * The Isovector Giant Dipole Resonance: GDR * The Isovector Giant Monopole Resonances: IVGMR * The Isovector Quadrupole Resonance: IVGQR * The Effect of Ground State Deformation on the Shape of Giant Resonance: Microscopic Picture * Giant Resonances Built on Excited States * Introduction * Capture Reactions on Light Nuclei * Statistical decay of GDR γ Emission in Heavy Compound Systems * Introduction * Theoretical Predictions * Some Experimental Results * Summary and Outlook * Acknowledgements * General References * References

  15. Sensory ecology: giant eyes for giant predators?

    PubMed

    Partridge, Julian C

    2012-04-24

    Mathematical models suggest the enormous eyes of giant and colossal squid evolved to see the bioluminescence induced by the approach of predatory whales. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Biomechanical Analysis of Locust Jumping in a Physically Realistic Virtual Environment

    NASA Astrophysics Data System (ADS)

    Cofer, David; Cymbalyuk, Gennady; Heitler, William; Edwards, Donald

    2008-03-01

    The biomechanical and neural components that underlie locust jumping have been extensively studied. Previous research suggested that jump energy is stored primarily in the extensor apodeme, and in a band of cuticle called the semi-lunar process (SLP). As it has thus far proven impossible to experimentally alter the SLP without rendering a locust unable to jump, it has not been possible to test whether the energy stored in the SLP has a significant impact on the jump. To address problems such as this we have developed a software toolkit, AnimatLab, which allows researchers to build and test virtual organisms. We used this software to build a virtual locust, and then asked how the SLP is utilized during jumping. The results show that without the SLP the jump distance was reduced by almost half. Further, the simulations were also able to show that loss of the SLP had a significant impact on the final phase of the jump. We are currently working on postural control mechanisms for targeted jumping in locust.

  17. Acute and chronic gregarisation are associated with distinct DNA methylation fingerprints in desert locusts

    PubMed Central

    Mallon, Eamonn B.; Amarasinghe, Harindra E.; Ott, Swidbert R.

    2016-01-01

    Desert locusts (Schistocerca gregaria) show a dramatic form of socially induced phenotypic plasticity known as phase polyphenism. In the absence of conspecifics, locusts occur in a shy and cryptic solitarious phase. Crowding with conspecifics drives a behavioural transformation towards gregariousness that occurs within hours and is followed by changes in physiology, colouration and morphology, resulting in the full gregarious phase syndrome. We analysed methylation-sensitive amplified fragment length polymorphisms (MS-AFLP) to compare the effect of acute and chronic crowding on DNA methylation in the central nervous system. We find that crowd-reared and solitary-reared locusts show markedly different neural MS-AFLP fingerprints. However, crowding for a day resulted in neural MS-AFLP fingerprints that were clearly distinct from both crowd-reared and uncrowded solitary-reared locusts. Our results indicate that changes in DNA methylation associated with behavioural gregarisation proceed through intermediate states that are not simply partial realisations of the endpoint states. PMID:27752110

  18. Unveiling the mechanism by which microsporidian parasites prevent locust swarm behavior

    PubMed Central

    Shi, Wangpeng; Guo, Yang; Xu, Chuan; Tan, Shuqian; Miao, Jing; Feng, Yanjie; Zhao, Hong; St. Leger, Raymond J.; Fang, Weiguo

    2014-01-01

    Locusts are infamous for their ability to aggregate into gregarious migratory swarms that pose a major threat to food security. Aggregation is elicited by an interplay of visual, tactile, and chemical stimuli, but the aggregation pheromone in feces is particularly important. Infection by the microsporidian parasite Paranosema (Nosema) locustae is known to inhibit aggregation of solitary Locusta migratoria manilensis and to induce gregarious locusts to shift back to solitary behavior. Here we suggest that P. locustae achieves this effect by acidifying the hindgut and modulating the locust immune response, which suppresses the growth of the hindgut bacteria that produce aggregation pheromones. This in turn reduces production of the neurotransmitter serotonin that initiates gregarious behavior. Healthy L. migratoria manilensis exposed to olfactory stimuli from parasite-infected locusts also produced significantly less serotonin, reducing gregarization. P. locustae also suppresses biosynthesis of the neurotransmitter dopamine that maintains gregarization. Our findings reveal the mechanisms by which P. locustae reduces production of aggregation pheromone and blocks the initiation and maintainence of gregarious behavior. PMID:24474758

  19. The role of the frontal ganglion in locust feeding and moulting related behaviours.

    PubMed

    Zilberstein, Yael; Ayali, Amir

    2002-09-01

    In the desert locust, Schistocerca gregaria, the frontal ganglion (FG) plays a key role in control of foregut movements, and constitutes a source of innervation to the foregut dilator muscles. In this work we studied the generation and characteristics of FG motor outputs in two distinct and fundamental behaviours: feeding and moulting. The FG motor pattern was found to be complex, and strongly dependent on the locust's physiological and behavioural state. Rhythmic activity of the foregut was dependent on the amount of food present in the crop; animals with food in their crop demonstrated higher FG burst frequency than those with empty crop. A very full gut inhibited the FG rhythm altogether. When no feeding-related foregut pattern was observed, the FG motor output was strongly correlated with the locust's ventilation pattern. This ventilation-related rhythm was dominant in pre-moulting locusts. During the moult, synchronization with the ventilation pattern can be transiently switched off, revealing the endogenous (feeding-related) FG pattern. This presumably happens during vigorous air swallowing, and could also be induced experimentally. Our findings suggest that the FG central pattern generator can be modulated to generate a variety of motor outputs under different physiological conditions and behavioural contexts.

  20. Heat-induced chemical and color changes of extractive-free Black Locust (Rosinia Pseudoacacia) wood

    Treesearch

    Yao Chen; Jianmin Gao; Yongming Fan; Mandla A. Tshabalala; Nicole M. Stark

    2012-01-01

    To investigate chemical and color changes of the polymeric constituents of black locust (Robinia pseudoacacia) wood during heat treatment, extractive-free wood flour was conditioned to 30% initial moisture content (MC) and heated for 24 h at 120 °C in either an oxygen or nitrogen atmosphere. The color change was measured using the CIELAB color system. Chemical changes...

  1. Simultaneous measurement of aerodynamic forces and kinematics in flapping wings of tethered locust.

    PubMed

    Shkarayev, Sergey; Kumar, Rajeev

    2015-10-23

    Aerodynamic and inertial forces and corresponding kinematics of flapping wings of locusts, Schistocerca americana, were investigated in a low-speed wind tunnel. The experimental setup included live locusts mounted on microbalance synchronized with a high-speed video system. Simultaneous measurements of wing kinematics and forces were carried out on three locusts at 7° angle of attack and velocities of 0 m s(-1) and 4 m s(-1). Time variations of flapping and pitching angles exhibit similar patterns in fore- and hindwings and among the animals. Significant tip to root variations in pitching angle are found in both wings. The locusts have much larger flapping and pitching amplitudes in still air causing larger oscillations in inertial forces. Inertial forces are added to the lift and thrust on one part of the stroke, resulting in higher reaction forces and subtracted on the other part. Plots of the lift demonstrate similar trends with and without the wind. The global maxima and peak-to-peak amplitudes in lift are about the same in both tests. However, local minima are significantly lower in still air, resulting in much smaller stroke-averaged lift. Amplitudes of thrust force oscillations are much higher in still air; consequently, the stroke-averaged thrust is higher compared to the non-zero freestream velocity case.

  2. (Z)-9-Pentacosene - contact sex pheromone of the locust borer, Megacyllene robiniae

    Treesearch

    Matthew D. Ginzel; Jocelyn G. Miller; Lawrence M. Hanks

    2003-01-01

    Male locust borers, Megacyllene robiniae (Forster), responded to females only after contacting them with their antennae, indicating that mate recognition was mediated by a contact sex pheromone. GC-MS analyses of whole-body extracts of males and females determined that the profiles of compounds in the extracts were qualitatively similar, but differed...

  3. From release to absorption: Elucidating the effects of a desert locust pheromone

    USDA-ARS?s Scientific Manuscript database

    We used a glass-vial bioassay to test the contact effect of the desert locust pheromone phenylacetonitrile (PAN) on nymphs and adults after 2 hand 4 h respectively, and quantified the amount of the pheromone absorbed and released by the nymphs after 2 h and 12 h. We also monitored the knockdown effe...

  4. Hydroponic screening of black locust families for heavy metal tolerance and accumulation.

    PubMed

    Župunski, Milan; Borišev, Milan; Orlović, Saša; Arsenov, Danijela; Nikolić, Nataša; Pilipović, Andrej; Pajević, Slobodanka

    2016-01-01

    Present work examines phytoextraction potential of four black locust families (half-sibs 54, 56, 115, and 135) grown hydroponically. Plants were treated with 6 ppm of cadmium (Cd), 100 ppm of nickel (Ni), and 40 ppm of lead (Pb) added in Hoagland nutrient solution, accompanying with simultaneously applied all three metals. Responses to metals exposure among families were different, ranging from severe to slight reduction of root and shoot biomass production of treated plants. Calculated tolerance indices are indicating tested families as highly tolerant (Ti > 60). Family 135 had the lowest tolerance index, pointing that it was highly susceptible to applied metals. Comparing photosynthetic activities of tested families it has been noticed that they were highly sensitive to stress induced by heavy metals. Net photosynthetic rate of nickel treated plants was the most affected by applied concentration. Cadmium and nickel concentrations in stems and leaves of black locust families exceeded 100 mg Cd kg(-1) and 1000 mg Ni kg(-1), in both single and multipollution context. On the contrary, accumulation of lead in above ground biomass was highly affected by multipollution treatment. Tf and BCF significantly varied between investigated treatments and families of black locust. Concerning obtained results of heavy metals accumulation and tolerance of black locust families can be concluded that tested families might be a promising tool for phytoextraction purposes, but it takes to be further confirmed in field trials.

  5. Diacylglycerol-carrying lipoprotein of hemolymph of the locust and some insects.

    PubMed

    Chino, H; Kitazawa, K

    1981-09-01

    The diacylglycerol-carrying lipoprotein (DGLP) was purified from hemolymph of the locust, Locusta migratoria, by a rapid method which included a specific precipitation at low ionic concentration and DEAE-cellulose column chromatography. The final preparation was highly homogeneous as judged by gel electrophoresis, electron microscopy, and immunodiffusion. The locust DGLP molecule was almost spherical in shape with a diameter of about 130 A. The molecular weight, determined by a sedimentation equilibrium method, was approximately 580,000. The total lipid content amounted to about 40%. The lipids comprised diacylglycerol (33% of total lipid), hydrocarbon (21%), cholesterol (8%), and phospholipids (36%). The hydrocarbon fraction contained a number of n-alkanes and methylalkanes ranging from C25 to C38 in chain length. Mannose (3%) and glucosamine (0.5%) were associated with the apoprotein of DGLP. Apoprotein of locust DGLP consisted of two subunits, heavy chain (mol wt 250,000) and light chain (mol wt 85,000); carbohydrate (mannose) was associated only with the heavy chain. Tests of physiological function of DGLPs from locust, cockroach, and silkworm suggest that the insect DGLP serves multiple roles as a true carrier molecule in transporting diacylglycerol, cholesterol, and hydrocarbon from sites of storage, absorption, and synthesis to sites where these lipids are utilized as metabolic fuel, precursors for triacylglycerol and phospholipid synthesis, or structural components of cell membrane and cuticle. In addition, the insect DGLPs displayed no species-specificity in terms of the functions, whereas they were immunologically distinguishable.

  6. Planting yellow-poplar, white ash, black cherry, and black locust

    Treesearch

    Robert D. Williams; Calvin F. Bey

    1989-01-01

    Hardwood plantations that include yellow-poplar, white ash, black cherry, and black locust can be established on upland sites in the central hardwoods region (see Note 3.06 Seeding and Planting Upland Oaks, and Note 3.08 Seeding and Planting Walnut). Even though hardwoods are more difficult to establish than conifers, there are...

  7. Behavioral thermoregulation in the migratory locust: a therapy to overcome fungal infection.

    PubMed

    Ouedraogo, R M; Goettel, M S; Brodeur, J

    2004-01-01

    We examined under laboratory conditions the thermopreference of the migratory locust, Locusta migratoria migratorioides, following infection by the entomopathogenic fungus Metarhizium anisopliae var. acridum and its influence on mycosis. Infected locusts raised their body temperature more frequently than healthy conspecifics through selection of high temperatures in a heat gradient. Thermoregulation did not, however, alter the frequency of feeding events nor the amount of food eaten by infected L. migratoria. A thermoregulation regime of a minimum of 4 h/day substantially increased survival of inoculated insects (by 85%). However, the therapeutic effect decreased when thermoregulation was delayed following inoculation of the pathogen. Thermoregulation reduced locust mortality but did not completely eliminate the fungus from infected hosts; the fungus grew and killed the insects when thermoregulation was interrupted. We suggest that periodic, short bouts of thermoregulation, when performed from the onset of infection and for an extended period of time, are sufficient to provide a therapeutic effect to infected hosts. Such thermoregulatory capacity of locusts may limit the potential of fungal pathogens as biological control agents under certain ecological conditions.

  8. Coding of odors by temporal binding within a model network of the locust antennal lobe

    PubMed Central

    Patel, Mainak J.; Rangan, Aaditya V.; Cai, David

    2013-01-01

    The locust olfactory system interfaces with the external world through antennal receptor neurons (ORNs), which represent odors in a distributed, combinatorial manner. ORN axons bundle together to form the antennal nerve, which relays sensory information centrally to the antennal lobe (AL). Within the AL, an odor generates a dynamically evolving ensemble of active cells, leading to a stimulus-specific temporal progression of neuronal spiking. This experimental observation has led to the hypothesis that an odor is encoded within the AL by a dynamically evolving trajectory of projection neuron (PN) activity that can be decoded piecewise to ascertain odor identity. In order to study information coding within the locust AL, we developed a scaled-down model of the locust AL using Hodgkin–Huxley-type neurons and biologically realistic connectivity parameters and current components. Using our model, we examined correlations in the precise timing of spikes across multiple neurons, and our results suggest an alternative to the dynamic trajectory hypothesis. We propose that the dynamical interplay of fast and slow inhibition within the locust AL induces temporally stable correlations in the spiking activity of an odor-dependent neural subset, giving rise to a temporal binding code that allows rapid stimulus detection by downstream elements. PMID:23630495

  9. Nonlinear time-periodic models of the longitudinal flight dynamics of desert locusts Schistocerca gregaria.

    PubMed

    Taylor, Graham K; Zbikowski, Rafał

    2005-06-22

    Previous studies of insect flight control have been statistical in approach, simply correlating wing kinematics with body kinematics or force production. Kinematics and forces are linked by Newtonian mechanics, so adopting a dynamics-based approach is necessary if we are to place the study of insect flight on its proper physical footing. Here we develop semi-empirical models of the longitudinal flight dynamics of desert locusts Schistocerca gregaria. We use instantaneous force-moment measurements from individual locusts to parametrize the nonlinear rigid body equations of motion. Since the instantaneous forces are approximately periodic, we represent them using Fourier series, which are embedded in the equations of motion to give a nonlinear time-periodic (NLTP) model. This is a proper mathematical generalization of an earlier linear-time invariant (LTI) model of locust flight dynamics, developed using previously published time-averaged versions of the instantaneous force recordings. We perform various numerical simulations, within the fitted range of the model, and across the range of body angles used by free-flying locusts, to explore the likely behaviour of the locusts upon release from the tether. Solutions of the NLTP models are compared with solutions of the nonlinear time-invariant (NLTI) models to which they reduce when the periodic terms are dropped. Both sets of models are unstable and therefore fail to explain locust flight stability fully. Nevertheless, whereas the measured forces include statistically significant harmonic content up to about the eighth harmonic, the simulated flight trajectories display no harmonic content above the fundamental forcing frequency. Hence, manoeuvre control in locusts will not directly reflect subtle changes in the higher harmonics of the wing beat, but must operate on a coarser time-scale. A state-space analysis of the NLTP models reveals orbital trajectories that are impossible to capture in the LTI and NLTI models, and

  10. The toxic and lethal effects of the trehalase inhibitor trehazolin in locusts are caused by hypoglycaemia.

    PubMed

    Wegener, Gerhard; Tschiedel, Volker; Schlöder, Paul; Ando, Osamu

    2003-04-01

    The main blood sugar of locusts is trehalose, which is hydrolysed to two glucose units by trehalase. Homogenates of locust flight muscles are rich in trehalase activity, which is bound to membranes. A minor fraction of trehalase is in an overt form while the remainder is latent, i.e. active only after impairing membrane integrity. Trehazolin, an antibiotic pseudosaccharide, inhibits locust flight muscle trehalase with apparent K(i)- and EC(50) values of 10(-8) mol l(-1) and 10(-7) mol l(-1), respectively. Trehazolin is insecticidal: 50 micro g injected into locusts completely and selectively blocked the overt form of muscle trehalase (with little effect on latent activity) and killed 50% of the insects within 24 h. Here, it is demonstrated for the first time that trehazolin causes dramatic hypoglycaemia. Injection of 10 micro g trehazolin caused glucose levels to fall by over 90% in 24 h, from 2.8 mmol l(-1) to 0.23 mmol l(-1), while trehalose increased from 61 mmol l(-1) to 111 mmol l(-1). Feeding glucose to the locusts fully neutralized the effects of a potentially lethal dose of trehazolin. This indicates that hypertrehalosaemia is not acutely toxic, whereas lack of glucose causes organ failure (presumably of the nervous system), and that sufficient haemolymph glucose can only be generated from trehalose by trehalase. The results also suggest that overt flight muscle trehalase is located in the plasma membrane with the active site accessible to the haemolymph. Trehalase inhibitors are valuable tools for studying the molecular physiology of trehalase function and sugar metabolism in insects.

  11. Mapping locust habitats in the Amudarya River Delta, Uzbekistan with multi-temporal MODIS imagery.

    PubMed

    Sivanpillai, Ramesh; Latchininsky, Alexandre V

    2007-06-01

    Reed beds of Phragmites australis in the River Amudarya delta near the Aral Sea constitute permanent breeding areas of the Asian Migratory locust, Locusta migratoria migratoria. Every year, thousands of hectares are treated with broad-spectrum insecticides to prevent locust swarms from damaging crops in adjacent areas. To devise efficient locust monitoring and management plans, accurate and updated information about the spatial distribution of reeds is necessary. Given the vast geographic extent of the delta, traditional, ground survey methods are inadequate. Remotely sensed data collected by the MODIS sensor aboard the TERRA satellite provide a useful tool to characterize the spatial distribution of reeds. Multi-temporal MODIS data, collected at different times of the growing season, were used to generate spectral-temporal signatures for reeds and other land cover classes. These spectral-temporal signatures were matched with reed phenology. MODIS information was digitally classified to generate a land cover map with an overall accuracy of 74%. MODIS data captured 87% of the ground-verified reed locations. Estimates derived from MODIS data indicate that 18% of the study area was covered by reeds. However, high commission error resulted from misclassification of reeds mixed with shrubs class and shrubs class as reeds. This could have resulted in overprediction of the area covered by reeds. Additional research is needed to minimize the overlap between reeds and other vegetation classes (shrubs, and reed and shrub mix). Nevertheless, despite its relatively low spatial resolution (250 m), multi-temporal MODIS data were able to adequately capture the distribution of reeds. Instead of blanketing the fragile wetland ecosystem of the Amudarya delta with chemical anti-locust treatments, plant protection specialists can use this information to devise ecologically sound pest management plans aimed at reducing the adverse environmental impact in the zone of the Aral Sea

  12. Spike frequency adaptation mediates looming stimulus selectivity in a collision-detecting neuron

    PubMed Central

    Peron, Simon; Gabbiani, Fabrizio

    2009-01-01

    How active membrane conductance dynamics tunes neurons for specific time-varying stimuli remains poorly understood. We studied the biophysical mechanisms by which spike frequency adaptation shapes visual stimulus selectivity in an identified visual interneuron of the locust. The lobula giant movement detector (LGMD) responds preferentially to objects approaching on a collision course with the locust. Using calcium imaging, pharmacology and modeling, we show that spike frequency adaptation in the LGMD is mediated by a Ca2+-dependent potassium conductance closely resembling those associated with ‘small-conductance’ (SK) channels. Intracellular block of this conductance minimally affected the LGMD’s response to approaching stimuli, but substantially increased its response to translating ones. Thus, spike frequency adaptation contributes to the neuron’s tuning by selectively decreasing its responses to nonpreferred stimuli. Our results identify a new mechanism by which spike frequency adaptation may tune visual neurons to behaviorally relevant stimuli. PMID:19198607

  13. Monitoring the intensity of locust damage to vegetation using hyper-spectra data obtained at ground surface

    NASA Astrophysics Data System (ADS)

    Ni, Shaoxiang; Wu, Tong

    2007-09-01

    Since 1980s of the last century, outbreak of Oriental Migratory Locust (Locusta migratoria manilensis Meyen) has rampantly emerged again in some regions of China. It is extremely important to monitor efficiently the locust damage to vegetation in order to control this kind of insect pest. In this paper, taking Huanghua County of Hebei province, China as the study area and based on the in situ hyper-spectral data, the differences in canopy reflectance spectra and the characteristic parameters of hyper-spectra were analyzed and compared for the reeds at normal growing and for those under encroaching from locusts. In addition, five models were developed to simulate the relations between the characteristic parameters of hyper-spectra and Leaf Area Index (LAI) of reeds. The result showed that among those indices the locust damage spectra index (LDSI) is mostly applicable to reflect the intensity of locust damage in the study area. Finally, a scheme for the intensity distinction of locust damage to reeds was suggested based on LDSI data, i.e., no damage if LDSI is over 62.856, slightly damage if LDSI is between 41.254 and 59.496, and seriously damage if LDSI is less than 41.254.

  14. An experimental evolution study confirms that discontinuous gas exchange does not contribute to body water conservation in locusts.

    PubMed

    Talal, Stav; Ayali, Amir; Gefen, Eran

    2016-12-01

    The adaptive nature of discontinuous gas exchange (DGE) in insects is contentious. The classic 'hygric hypothesis', which posits that DGE serves to reduce respiratory water loss (RWL), is still the best supported. We thus focused on the hygric hypothesis in this first-ever experimental evolution study of any of the competing adaptive hypotheses. We compared populations of the migratory locust (Locusta migratoria) that underwent 10 consecutive generations of selection for desiccation resistance with control populations. Selected locusts survived 36% longer under desiccation stress but DGE prevalence did not differ between these and control populations (approx. 75%). Evolved changes in DGE properties in the selected locusts included longer cycle and interburst durations. However, in contrast with predictions of the hygric hypothesis, these changes were not associated with reduced RWL rates. Other responses observed in the selected locusts were higher body water content when hydrated and lower total evaporative water loss rates. Hence, our data suggest that DGE cycle properties in selected locusts are a consequence of an evolved increased ability to store water, and thus an improved capacity to buffer accumulated CO2, rather than an adaptive response to desiccation. We conclude that DGE is unlikely to be an evolutionary response to dehydration challenge in locusts.

  15. RNAi-mediated knockdown of Shade negatively affects ecdysone-20-hydroxylation in the desert locust, Schistocerca gregaria.

    PubMed

    Marchal, Elisabeth; Verlinden, Heleen; Badisco, Liesbeth; Van Wielendaele, Pieter; Vanden Broeck, Jozef

    2012-07-01

    A major breakthrough in elucidating the ecdysteroid biosynthetic pathway in insects was realized with the molecular identification and further functional characterization of the 'Halloween' genes. These genes were found to encode cytochrome P450 enzymes catalysing the final steps of ecdysteroid biosynthesis in the dipteran, Drosophila melanogaster, and in the Lepidoptera, Manduca sexta and Bombyx mori. A recent report focused on the identification of Halloween orthologs in the desert locust, Schistocerca gregaria, a member of the hemimetabolous insect order of the Orthoptera. In the present study, an additional Halloween gene Shade, is identified in the desert locust. In Diptera and Lepidoptera, this gene encodes a 20-hydroxylase, catalysing the conversion of ecdysone (E) to 20-hydroxyecdysone (20E). However, this enzymatic function has previously been suggested for CYP6H1 in another locust species, the migratory locust, Locusta migratoria. Using q-RT-PCR, the spatial and temporal transcript profiles of S. gregaria orthologs for Shade as well as CYP6H1 were analysed in last larval stage desert locusts. An RNA interference (RNAi)-based approach was employed to study whether these genes could possibly encode a functional 20-hydroxylase in the desert locust. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. A Locust Phase Change Model with Multiple Switching States and Random Perturbation

    NASA Astrophysics Data System (ADS)

    Xiang, Changcheng; Tang, Sanyi; Cheke, Robert A.; Qin, Wenjie

    2016-12-01

    Insects such as locusts and some moths can transform from a solitarious phase when they remain in loose populations and a gregarious phase, when they may swarm. Therefore, the key to effective management of outbreaks of species such as the desert locust Schistocercagregaria is early detection of when they are in the threshold state between the two phases, followed by timely control of their hopper stages before they fledge because the control of flying adult swarms is costly and often ineffective. Definitions of gregarization thresholds should assist preventive control measures and avoid treatment of areas that might not lead to gregarization. In order to better understand the effects of the threshold density which represents the gregarization threshold on the outbreak of a locust population, we developed a model of a discrete switching system. The proposed model allows us to address: (1) How frequently switching occurs from solitarious to gregarious phases and vice versa; (2) When do stable switching transients occur, the existence of which indicate that solutions with larger amplitudes can switch to a stable attractor with a value less than the switching threshold density?; and (3) How does random perturbation influence the switching pattern? Our results show that both subsystems have refuge equilibrium points, outbreak equilibrium points and bistable equilibria. Further, the outbreak equilibrium points and bistable equilibria can coexist for a wide range of parameters and can switch from one to another. This type of switching is sensitive to the intrinsic growth rate and the initial values of the locust population, and may result in locust population outbreaks and phase switching once a small perturbation occurs. Moreover, the simulation results indicate that the switching transient patterns become identical after some generations, suggesting that the evolving process of the perturbation system is not related to the initial value after some fixed number of

  17. Evaluation of honey locust (Gleditsia triacanthos Linn.) gum as sustaining material in tablet dosage forms.

    PubMed

    Uner, Melike; Altinkurt, Turan

    2004-07-01

    In this study, honey locust gum (HLG) obtained from Gleditsia triacanthos (honey locust) beans was investigated as a hydrophilic matrix material in the tablets prepared at different concentrations (5% and 10%) by wet granulation method. Theophylline was chosen as a model drug. The matrix tablets containing hydroxyethylcellulose and hydroxypropyl methylcellulose as sustaining polymers at the same concentrations were prepared and a commercial sustained release (CSR) tablet containing 200 mg theophylline was examined for comparison of HLG performance. Physical analysis on CSR tablet, matrix tablets and their granules before compression were performed. According to the results obtained from dissolution studies in distilled water, pH 1.2 HCl buffer and pH 7.2 phosphate buffer, no significant difference was found between CSR tablet and the matrix tablet containing 10% HLG in each medium (P > 0.05) and these tablets showed zero-order kinetic model in all the mediums.

  18. Myctolaimellus robiniae n. sp. (Diplogasterida: Cylindrocorporidae) from Larval Cavities of the Locust Borer, Megacyllene robiniae Forster

    PubMed Central

    Harman, A.; Winter, J.; Harman, D.

    2000-01-01

    A new nematode species of the family Cylindrocorporidae and the genus Myctolaimellus from subcortical cavities made by the locust borer (Megacyllene robiniae Forster) in black locust (Robinia pseudoacacia L.) is described. Males of the new species have a length of 700 to 1,050 µm; a bursate tail, peloderan with nine pairs of rays; and knobbed, curved spicules with tips bending gently into a hook. The distinctive gubernaculum is half the length of the spicules, deeply grooved longitudinally along both its dorsal and ventral surfaces, and has a spoon-shaped end. Females have a length of 830 to 1,340 µm, an amphidelphic reproductive tract with long ovaries crossing each other to extend beyond the equatorial vulva, and a gradually tapering tail. PMID:19270993

  19. Myctolaimellus robiniae n. sp. (Diplogasterida: Cylindrocorporidae) from Larval Cavities of the Locust Borer, Megacyllene robiniae Forster.

    PubMed

    Harman, A; Winter, J; Harman, D

    2000-12-01

    A new nematode species of the family Cylindrocorporidae and the genus Myctolaimellus from subcortical cavities made by the locust borer (Megacyllene robiniae Forster) in black locust (Robinia pseudoacacia L.) is described. Males of the new species have a length of 700 to 1,050 microm; a bursate tail, peloderan with nine pairs of rays; and knobbed, curved spicules with tips bending gently into a hook. The distinctive gubernaculum is half the length of the spicules, deeply grooved longitudinally along both its dorsal and ventral surfaces, and has a spoon-shaped end. Females have a length of 830 to 1,340 microm, an amphidelphic reproductive tract with long ovaries crossing each other to extend beyond the equatorial vulva, and a gradually tapering tail.

  20. The mechanism controlling phenotypic plasticity of body color in the desert locust: some recent progress.

    PubMed

    Tanaka, Seiji; Harano, Ken-Ichi; Nishide, Yudai; Sugahara, Ryohei

    2016-10-01

    Schistocerca gregaria exhibits density-dependent body color polyphenism. Nymphs occurring at low population densities show green-brown polyphenism. They show phase polyphenism and develop black patterns at high population densities. Recent studies suggest a third type of polyphensim, that is, homochromy, a response to background color. Laboratory experiments that considered homochromy suggest that humidity is not directly involved in green-brown polyphenism and that odor from other individuals does not induce black patterns. Black patterns can be induced in isolated nymphs by video images of locusts and tadpoles. Juvenile hormone and [His(7)]-corazonin control body color in locusts. The gene encoding the latter has been identified for S. gregaria and Locusta migratoria, and its key role in controlling black patterning has been demonstrated. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Distribution and specific central projections of mechanoreceptors in the thorax and proximal leg joints of locusts.

    PubMed

    Hustert, R; Pflüger, J H; Bräunig, P

    1981-01-01

    Campaniform sensilla (CS) of the locust proximal leg segments are arranged predominantly as homologous groups on the trochantera and femora. Their number is reduced in the more specialized jumping legs. The specific projections of the primary afferent axons from single groups of CS are visualized after backfilling them with CoCl2 introduced through the dendritic area in the cuticle. The majority of central branching patterns reveal a high degree of uniformity if compared within a population, between populations of one segment, and between populations of different legs. All projections bifurcate close to the peripheral root of the leg nerve and are restricted to the ipsilateral hemiganglion of the segments. These projections seem to differ in their extent more or less from those campaniform sensilla in other parts of the locust and in other insects.

  2. Low density cell culture of locust neurons in closed-channel microfluidic devices.

    PubMed

    Göbbels, Katrin; Thiebes, Anja Lena; van Ooyen, André; Schnakenberg, Uwe; Bräunig, Peter

    2010-08-01

    Microfluidic channel systems were fabricated out of polydimethylsiloxane (PDMS) and used as culture vessels for primary culture of neurons from locust thoracic ganglia. In a biocompatibility study it was shown that cell adhesion and neuronal cell growth of locust neurons on uncoated PDMS was restricted. Coating with concanavalin A improved cell adhesion. In closed-channel microfluidic devices neurons were grown in static-bath culture conditions for more than 15 days. Cell densities of up to 20 cells/channel were not exceeded in low-density cultures but we also found optimal cell growth of single neurons inside individual channels. The first successful cultivation of insect neurons in closed-channel microfluidic devices provides a prerequisite for the development of low density neuronal networks on multi electrode arrays combined with microfluidic devices.

  3. [Isolation of protein of the chymotrypsin inhibitor from honey locust seeds].

    PubMed

    Mosolov, V V; Valueva, T A; Kolosova, G V

    1982-12-01

    The chymotrypsin inhibitor was isolated from honey locust (Gleditsia triacanthos L.) by chromatography on trypsin- and chymotrypsin-Sepharose 4B and by gel filtration on Sephadex G-75. The inhibitor can inhibit chymotrypsin but has no effect on trypsin, subtilisin and proteinases from Asp. oryzae and Str. griseus. The inhibitor forms a complex with chymotrypsin at a molar ratio of 1:1, has a molecular weight of about 20,000 and a low content of half-cysteine.

  4. Dynamic model and performance analysis of landing buffer for bionic locust mechanism

    NASA Astrophysics Data System (ADS)

    Chen, Dian-Sheng; Zhang, Zi-Qiang; Chen, Ke-Wei

    2016-06-01

    The landing buffer is an important problem in the research on bionic locust jumping robots, and the different modes of landing and buffering can affect the dynamic performance of the buffering process significantly. Based on an experimental observation, the different modes of landing and buffering are determined, which include the different numbers of landing legs and different motion modes of legs in the buffering process. Then a bionic locust mechanism is established, and the springs are used to replace the leg muscles to achieve a buffering effect. To reveal the dynamic performance in the buffering process of the bionic locust mechanism, a dynamic model is established with different modes of landing and buffering. In particular, to analyze the buffering process conveniently, an equivalent vibration dynamic model of the bionic locust mechanism is proposed. Given the support forces of the ground to the leg links, which can be obtained from the dynamic model, the spring forces of the legs and the impact resistance of each leg are the important parameters affecting buffering performance, and evaluation principles for buffering performance are proposed according to the aforementioned parameters. Based on the dynamic model and these evaluation principles, the buffering performances are analyzed and compared in different modes of landing and buffering on a horizontal plane and an inclined plane. The results show that the mechanism with the ends of the legs sliding can obtain a better dynamic performance. This study offers primary theories for buffering dynamics and an evaluation of landing buffer performance, and it establishes a theoretical basis for studies and engineering applications.

  5. Seasonal Fluctuations of Lectins in Barks of Elderberry (Sambucus nigra) and Black Locust (Robinia pseudoacacia) 1

    PubMed Central

    Nsimba-Lubaki, Makuta; Peumans, Willy J.

    1986-01-01

    Elderberry (Sambucus nigra) and black locust (Robinia pseudoacacia) agglutinins, which are abundantly present in the bark of both species, display seasonal fluctuations with regard to their content in this tissue. These seasonal changes result apparently from a circa-annual rhythm of lectin accumulation and depletion during autumn and spring, respectively. Because the bark of trees can be considered as a type of vegetative storage tissue, the results suggest that bark lectins behave as typical storage proteins. Images Fig. 4 PMID:16664696

  6. Locust bean gum as superdisintegrant--formulation and evaluation of nimesulide orodispersible tablets.

    PubMed

    Malik, Karan; Arora, Gurpreet; Singh, Inderbir

    2011-01-01

    Orodispersible tablets disperse instantaneously in the mouth so that they can be swallowed without the aid of water. The aim of the present study was to formulate nimesulide orodispersible tablets using locust bean gum as a natural superdisintegrant. The gum was evaluated for powder flow properties, swelling index and loss on drying. Excellent powder flow properties were observed, swelling index was found to be 20 which indicated appreciable capability of locust bean gum to be used as superdisintegrant. The prepared tablets were evaluated against standard superdisintegrant i.e. cross-carmellose sodium. Disintegration time of tablets containing 10 % locust bean gum was found to be 13 seconds. The prepared batches were also evaluated for wetting time, water absorption ratio, effective pore radius, porosity, in vitro and in vivo disintegration time, in vitro release and stability studies. Wetting time was found to reduce from 19 +/- 2 to 11 +/- 3 sec (A1-A4) and 51 +/- 2 to 36 +/- 3 sec (B1-B4). Effective pore radius and porosity were found to be increase with increase in polymer concentration. The superdisintegrant property of locust bean gum may be due to concentration dependent wicking action leading to formation of porous structure which disintegrates the tablet within seconds. In-vivo results were complementary to in-vitro disintegration time results. The in-vitro release studies were compared against marketed nimesulide fast dissolving tablets (Nimulid MD). Stability studies showed that there was no significant change in hardness, friability, tensile strength and assay of the prepared formulations. The f2 values (in comparison with Nimulid MD) of 92.27 and 98.19 were obtained with A3 and A4 batches respectively.

  7. Giant prostatic calculi

    PubMed Central

    Najoui, Mohammed; Qarro, Abdelmounaim; Ammani, Abdelghani; Alami, Mohammed

    2013-01-01

    Prostatic parenchymal calculi are common, usually incidental, findings on morphological examinations. They are typically asymptomatic and may be present in association with normal glands, benign prostatic hyperplasia, and prostate cancer. However giant prostatic calculi are rare. Less than 20 cases have been reported in the literature. We present the case of a 35-year-old man with two giant prostatic calculi that replaced the entire gland. He underwent an open cystolithotomy, two giant stones were removed from the prostate, and we used a lithotripsy in situ for extraction of stone fragments. PMID:23565316

  8. Unstable giant gravitons

    SciTech Connect

    Mello Koch, Robert de; Ives, Norman; Smolic, Jelena; Smolic, Milena

    2006-03-15

    We find giant graviton solutions in Frolov's three parameter generalization of the Lunin-Maldacena background. The background we study has {gamma}-tilde{sub 1}=0 and {gamma}-tilde{sub 2}={gamma}-tilde{sub 3}={gamma}-tilde. This class of backgrounds provides a nonsupersymmetric example of the gauge theory/gravity correspondence that can be tested quantitatively, as recently shown by Frolov, Roiban, and Tseytlin. The giant graviton solutions we find have a greater energy than the point gravitons, making them unstable states. Despite this, we find striking quantitative agreement between the gauge theory and gravity descriptions of open strings attached to the giant.

  9. Microarray-based annotation of the gut transcriptome of the migratory locust, Locusta migratoria.

    PubMed

    Spit, J; Badisco, L; Vergauwen, L; Knapen, D; Vanden Broeck, J

    2016-12-01

    The migratory locust, Locusta migratoria, is a serious agricultural pest and important insect model in the study of insect digestion and feeding behaviour. The gut is one of the primary interfaces between the insect and its environment. Nevertheless, knowledge on the gut transcriptome of L. migratoria is still very limited. Here, 48 802 expressed sequence tags were extracted from publicly available databases and their expression in larval gut and/or brain tissue was determined using microarray hybridization. Our data show 2765 transcripts predominantly or exclusively expressed in the gut. Many transcripts had putative functions closely related to the physiological functions of the gut as a muscular digestive organ and as the first barrier against microorganisms and a wide range of toxins. By means of a ranking procedure based on the relative signal intensity, we estimated 15% of the transcripts to show high expression levels, the highest belonging to diverse digestive enzymes and muscle-related proteins. We also found evidence for very high expression of an allergen protein, which could have important implications, as locusts form a traditional food source in various parts of the world, and were also recently added to the list of insects fit for human consumption in Europe. Interestingly, many highly expressed sequences have as yet unknown functions. Taken together, the present data provide significant insight into locust larval gut physiology, and will be valuable for future studies on the insect gut.

  10. Time-varying span efficiency through the wingbeat of desert locusts

    PubMed Central

    Henningsson, Per; Bomphrey, Richard J.

    2012-01-01

    The flight performance of animals depends greatly on the efficacy with which they generate aerodynamic forces. Accordingly, maximum range, load-lifting capacity and peak accelerations during manoeuvres are all constrained by the efficiency of momentum transfer to the wake. Here, we use high-speed particle image velocimetry (1 kHz) to record flow velocities in the near wake of desert locusts (Schistocerca gregaria, Forskål). We use the measured flow fields to calculate time-varying span efficiency throughout the wing stroke cycle. The locusts are found to operate at a maximum span efficiency of 79 per cent, typically at a plateau of about 60 per cent for the majority of the downstroke, but at lower values during the upstroke. Moreover, the calculated span efficiencies are highest when the largest lift forces are being generated (90% of the total lift is generated during the plateau of span efficiency) suggesting that the combination of wing kinematics and morphology in locust flight perform most efficiently when doing the most work. PMID:22112649

  11. Exposure to heat shock affects thermosensitivity of the locust flight system.

    PubMed

    Robertson, R M; Xu, H; Shoemaker, K L; Dawson-Scully, K

    1996-03-01

    The natural habitat of the migratory locust, Locusta migratoria, is likely to result in locusts being heat stressed during their normal adult life. It is known that locusts exhibit a heat-shock response: exposure to 45 degrees C for 3 h induces thermotolerance and the expression of heat-shock proteins. We investigated the effects of exposure to heat-shock conditions on the thermosensitivity of flight rhythm generation in tethered, intact animals and in deafferented preparations. Heat shock had no effect on wingbeat frequency measured at the start of flight sequences, nor did it affect the postimaginal maturation of this parameter. During sustained flight, heat shock slowed the characteristic asymptotic reduction of wingbeat frequency. Wingbeat frequency of heat-shocked animals was less sensitive to temperature in the range 24 degrees to 47 degrees C than that of control animals, and the upper temperature limit, above which flight rhythms could not be produced, was 6 degrees to 7 degrees C higher in heat-shocked animals. These results were mirrored in the response of deafferented preparations, indicating that modifications in the properties of the flight neuromuscular system were involved in mediating the response of the intact animal. We propose that exposure to heat shock had the adaptive consequences of reducing thermosensitivity of the neural circuits in the flight system and allowing them to operate at higher temperatures.

  12. The locust frontal ganglion: a multi-tasked central pattern generator.

    PubMed

    Ayali, A; Zilberstein, Yael

    2004-01-01

    The locust frontal ganglion (FG) constitutes a major source of innervation to the foregut dilator muscles and thus plays a key role in control of foregut movements. This paper reviews our recent studies on the generation and characteristics of FG motor outputs in two distinct and fundamental locust behaviors: feeding and molting. In an in vitro preparation, isolated from all descending and sensory inputs, the FG was spontaneously active and generated rhythmic multi-unit bursts of action potentials, which could be recorded from all efferent nerves. Thus the FG motor pattern is generated by a central pattern generator within the ganglion. Intracellular recordings suggest that only a small fraction (10-20%) of the FG 100 neurons demonstrate rhythmic activity. The FG motor output in vivo was relatively complex, and strongly dependent on the locust's physiological and behavioral state. Rhythmic activity of the foregut was found to depend on the amount of food present in the crop; animals with full crop demonstrated higher FG burst frequency than those with empty crop. At the molt, the FG generates a distinct motor pattern that could be related to air-swallowing behavior.

  13. Embryonic diapause in the Australian plague locust relative to parental experience of cumulative photophase decline.

    PubMed

    Deveson, Edward D; Woodman, James D

    2014-11-01

    The Australian plague locust Chortoicetes terminifera (Walker) exhibits facultative embryonic diapause during autumn. To approximate natural photoperiod changes during late summer and autumn, locust nymphs were reared under different total declines in laboratory photophase (-0.5, -0.75, -1.0, -1.25, -1.5, -1.75, -2 h each lowered in 15 min steps) in a 24 h photoperiod to quantify any effect on the subsequent production of diapause eggs. Induction of diapause eggs was significantly affected by accumulated photoperiod decline experienced by the parental generation throughout all development stages from mid-instar nymph to fledgling adult. The incidence of embryonic diapause ranged from nil at -0.5 h to 86.6% diapause at -2 h. Continued declines in photoperiod for post-teneral locusts (transitioned from -1h until fledging to -1.75 h) produced a further increase in the proportion of diapause eggs. The results were unaffected by time spent at any given photoperiod, despite a previously indicated maximal inductive photoperiod of 13.5h being used as the mid-point of all treatments. Implications for the seasonal timing processes of photoperiodism in C. terminifera, which has a high migratory capacity and a latitudinal cline in the timing of diapause egg production across a broad geographic range, are discussed.

  14. Disruption of the blood-brain barrier exacerbates spreading depression in the locust CNS.

    PubMed

    Spong, Kristin E; Rochon-Terry, Geneviève; Money, Tomas G A; Robertson, R Meldrum

    2014-07-01

    In response to cellular stress in the nervous system of the locust (Locusta migratoria) neural function is interrupted in association with ionic disturbances propagating throughout nervous tissue (Spreading depression; SD). The insect blood-brain barrier (BBB) plays a critical role in the regulation of ion levels within the CNS. We investigated how a disruption in barrier function by transient exposure to 3M urea affects locusts' vulnerability to disturbances in ion levels. Repetitive SD was induced by bath application of ouabain and the extracellular potassium concentration ([K(+)]o) within the metathoracic ganglion (MTG) was monitored. Urea treatment increased the susceptibility to ouabain and caused a progressive impairment in the ability to maintain baseline [K(+)]o levels during episodes of repetitive SD. Additionally, using a within animal protocol we demonstrate that waves of SD, induced by high K(+), propagate throughout the MTG faster following disruption of the BBB. Lastly, we show that targeting the BBB of intact animals reduces their ability to sustain neural function during anoxic conditions. Our findings indicate that locust's ability to withstand stress is diminished following a reduction in barrier function likely due to an impairment of the ability of neural tissue to maintain ionic gradients.

  15. Long-term effects of the trehalase inhibitor trehazolin on trehalase activity in locust flight muscle.

    PubMed

    Wegener, Gerhard; Macho, Claudia; Schlöder, Paul; Kamp, Günter; Ando, Osamu

    2010-11-15

    Trehalase (EC 3.2.1.28) hydrolyzes the main haemolymph sugar of insects, trehalose, into the essential cellular substrate glucose. Trehalase in locust flight muscle is bound to membranes that appear in the microsomal fraction upon tissue fractionation, but the exact location in vivo has remained elusive. Trehalase has been proposed to be regulated by a novel type of activity control that is based on the reversible transformation of a latent (inactive) form into an overt (active) form. Most trehalase activity from saline-injected controls was membrane-bound (95%) and comprised an overt form (∼25%) and a latent form (75%). Latent trehalase could be assayed only after the integrity of membranes had been destroyed. Trehazolin, a potent tight-binding inhibitor of trehalase, is confined to the extracellular space and has been used as a tool to gather information on the relationship between latent and overt trehalase. Trehazolin was injected into the haemolymph of locusts, and the trehalase activity of the flight muscle was determined at different times over a 30-day period. Total trehalase activity in locust flight muscle was markedly inhibited during the first half of the interval, but reappeared during the second half. Inhibition of the overt form preceded inhibition of the latent form, and the time course suggested a reversible precursor-product relation (cycling) between the two forms. The results support the working hypothesis that trehalase functions as an ectoenzyme, the activity of which is regulated by reversible transformation of latent into overt trehalase.

  16. Environmental Adaptation, Phenotypic Plasticity, and Associative Learning in Insects: The Desert Locust as a Case Study.

    PubMed

    Simões, Patrício M V; Ott, Swidbert R; Niven, Jeremy E

    2016-11-01

    The ability to learn and store information should be adapted to the environment in which animals operate to confer a selective advantage. Yet the relationship between learning, memory, and the environment is poorly understood, and further complicated by phenotypic plasticity caused by the very environment in which learning and memory need to operate. Many insect species show polyphenism, an extreme form of phenotypic plasticity, allowing them to occupy distinct environments by producing two or more alternative phenotypes. Yet how the learning and memories capabilities of these alternative phenotypes are adapted to their specific environments remains unknown for most polyphenic insect species. The desert locust can exist as one of two extreme phenotypes or phases, solitarious and gregarious. Recent studies of associative food-odor learning in this locust have shown that aversive but not appetitive learning differs between phases. Furthermore, switching from the solitarious to the gregarious phase (gregarization) prevents locusts acquiring new learned aversions, enabling them to convert an aversive memory formed in the solitarious phase to an appetitive one in the gregarious phase. This conversion provides a neuroecological mechanism that matches key changes in the behavioral environments of the two phases. These findings emphasize the importance of understanding the neural mechanisms that generate ecologically relevant behaviors and the interactions between different forms of behavioral plasticity.

  17. Jump stabilization and landing control by wing-spreading of a locust-inspired jumper.

    PubMed

    Beck, Avishai; Zaytsev, Valentin; Ben-Hanan, Uri; Kosa, Gabor; Ayali, Amir; Weiss, Avi

    2017-09-15

    Bio-inspired robotics is a promising design strategy for mobile robots. Jumping is an energy efficient locomotion gait for traversing difficult terrain. Inspired by the jumping and flying behavior of the desert locust, we have recently developed a miniature jumping robot that can jump over 3.5 m high. However, much like the non-adult locust, it rotates while in the air and lands uncontrollably. Inspired by the winged adult locust, we have added spreading wings and a tail to the jumper. After the robot leaps, at the apex of the trajectory, the wings unfold and it glides to the ground. The advantages of this maneuver are the stabilization of the robot when airborne, the reduction of velocity at landing, the control of the landing angle and the potential to change the robot's orientation and control its flight trajectory. The new upgraded robot is capable of jumping to a still impressive height of 1.7 m eliminating airborne rotation and reducing landing velocity. Here, we analyze the dynamic and aerodynamic models of the robot, discuss the robot's design, and validate its ability to perform a jump-glide in a stable trajectory, land safely and change its orientation while in the air. © 2017 IOP Publishing Ltd.

  18. Regulation of water and macronutrients by the Australian plague locust, Chortoicetes terminifera.

    PubMed

    Clissold, Fiona J; Kertesz, Helena; Saul, Amelia M; Sheehan, Julia L; Simpson, Stephen J

    2014-10-01

    Nutritional outcomes for animals are best understood when the intake of multiple nutrients are considered together. The requirements for protein and carbohydrate and the consequences for development, growth and fitness when confined to sub-optimal amounts and ratios of these nutrients are well known for many herbivorous insects. Water is also essential for life, and it is known that herbivorous insects will actively ingest free water, have physiological mechanisms controlling thirst, and suffer fitness consequences if water is excessive or deficient in the diet. As herbivorous insects are thought to obtain the majority of their water from foliage, which can vary in protein, carbohydrate and water content, we investigated if the Australian plague locust, Chortoicetes terminifera, can select among complementary foods to attain a target intake across these three nutrient dimensions. Locusts demonstrated selection behaviour for protein, carbohydrate and water by eating non-randomly from different combinations of complementary foods. A ratio of P:C:H2O of 1:1.13:13.2 or 1(P+C): 6.2 H2O was ingested. Given that locusts strongly regulate water intake, and its importance as an essential resource, we suggest future studies consider the single and interactive influences of water, protein and carbohydrate, when evaluating herbivorous insect host choice and foraging decisions. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  19. Modulation of behavioral phase changes of the migratory locust by the catecholamine metabolic pathway

    PubMed Central

    Ma, Zongyuan; Guo, Wei; Guo, Xiaojiao; Wang, Xianhui; Kang, Le

    2011-01-01

    The migratory locust, Locusta migratoria, shows a striking phenotypic plasticity. It transitions between solitary and gregarious phases in response to population density changes. However, the molecular mechanism underlying the phase-dependent behavior changes remains elusive. Here we report a genome-wide gene expression profiling of gregarious and solitary nymphs at each stadium of the migratory locust, and we identified the most differentially expressed genes in the fourth stadium of the two phases. Bioinformatics analysis indicated that the catecholamine metabolic pathway was the most significant pathway up-regulated in the gregarious phase. We found pale, henna, and vat1, involved in dopamine biosynthesis and synaptic release, were critical target genes related to behavioral phase changes in the locusts. The roles of these genes in mediating behavioral changes in the gregarious individuals were confirmed by RNAi and pharmacological intervention. A single injection of dopamine or its agonist initiated gregarious behavior. Moreover, continuous and multiple injections of a dopamine agonist coupled with crowding resulted in more pronounced gregarious behavior. Our study thus provides insights into the relationships between genes and behavior in phase transition of this important pest species. PMID:21325054

  20. Relationship between desert locust, Schistocerca gregaria (Forskål), infestation, environmental factors and control measures in Gazan and Makkah Regions, Saudi Arabia.

    PubMed

    Al-Ajlan, Abdulaziz M

    2007-10-15

    Desert Locust, Schistocerca gregaria (Forskål), is one of the most important insect pests in Saudi Arabia. Cultivated crops and the range lands are heavily affected by desert locust in some regions of Saudi Arabia. The objective of this study was to determine the extent of damage by the Desert Locust, Schistocerca gregaria (Forskål) to the range lands being used for grazing range animals in Gazan and Makkah regions of Saudi Arabia. However, it is very difficult to estimate accurately the total infested areas, which were sprayed with insecticides to control upsurges, outbreaks and plagues over the last five decades. Records of Desert Locust control are kept in the National Desert Locust Control and Research Center in Jeddah. Meteorological data was obtained from the Meteorology and Environmental Protection Administration (MEPA), Saudi Arabia. The data shows that the Desert Locust infestation was associated partially with the rainfall intensity in Gazan and Makkah regions. There was found a good relationship between Desert Locust infestation (Solitary phase), temperature and the relative humidity. The locust infestation was heavy during 1986-88, 1992-95 and 1997-98 and about 1.8 million ha were treated with insecticides. Out of the total breeding/infested area, 43% was treated in winter months (October-February) and the remaining 57% was treated in spring season (March-June). The infested area was sprayed with Marshall, Carbosulfan (20%), Malathion (96%, Clorpyrifos; (48%) Fipronil (12.5%), Sumithion (100%) and Decis (12.5%). The study showed an excellent potential to determine the active locust infestation period in relation to the environmental factors for its effective control with insecticide sprays to minimize crop damage. The study highlighted the needs for further investigations in other locust infested areas with different environmental factors for planning future desert locust control programs.

  1. Timely monitoring of Asian Migratory locust habitats in the Amudarya delta, Uzbekistan using time series of satellite remote sensing vegetation index.

    PubMed

    Löw, Fabian; Waldner, François; Latchininsky, Alexandre; Biradar, Chandrashekhar; Bolkart, Maximilian; Colditz, René R

    2016-12-01

    The Asian Migratory locust (Locusta migratoria migratoria L.) is a pest that continuously threatens crops in the Amudarya River delta near the Aral Sea in Uzbekistan, Central Asia. Its development coincides with the growing period of its main food plant, a tall reed grass (Phragmites australis), which represents the predominant vegetation in the delta and which cover vast areas of the former Aral Sea, which is desiccating since the 1960s. Current locust survey methods and control practices would tremendously benefit from accurate and timely spatially explicit information on the potential locust habitat distribution. To that aim, satellite observation from the MODIS Terra/Aqua satellites and in-situ observations were combined to monitor potential locust habitats according to their corresponding risk of infestations along the growing season. A Random Forest (RF) algorithm was applied for classifying time series of MODIS enhanced vegetation index (EVI) from 2003 to 2014 at an 8-day interval. Based on an independent ground truth data set, classification accuracies of reeds posing a medium or high risk of locust infestation exceeded 89% on average. For the 12-year period covered in this study, an average of 7504 km(2) (28% of the observed area) was flagged as potential locust habitat and 5% represents a permanent high risk of locust infestation. Results are instrumental for predicting potential locust outbreaks and developing well-targeted management plans. The method offers positive perspectives for locust management and treatment of infested sites because it is able to deliver risk maps in near real time, with an accuracy of 80% in April-May which coincides with both locust hatching and the first control surveys. Such maps could help in rapid decision-making regarding control interventions against the initial locust congregations, and thus the efficiency of survey teams and the chemical treatments could be increased, thus potentially reducing environmental pollution

  2. The olfactory co-receptor Orco from the migratory locust (Locusta migratoria) and the desert locust (Schistocerca gregaria): identification and expression pattern.

    PubMed

    Yang, Ying; Krieger, Jürgen; Zhang, Long; Breer, Heinz

    2012-01-01

    In locusts, olfaction plays a crucial role for initiating and controlling behaviours, including food seeking and aggregation with conspecifics, which underlie the agricultural pest capacity of the animals. In this context, the molecular basis of olfaction in these insects is of particular interest. Here, we have identified genes of two orthopteran species, Locusta migratoria and Schistocera gregaria, which encode the olfactory receptor co-receptor (Orco). It was found that the sequences of LmigOrco and SgreOrco share a high degree of identity to each other and also to Orco proteins from different insect orders. The Orco-expressing cells in the antenna of S. gregaria and L. migratoria were visualized by in situ hybridization. Orco expression could be assigned to clusters of cells in sensilla basiconica and few cells in sensilla trichodea, most likely representing olfactory sensory neurons. No Orco-positive cells were detected in sensilla coeloconica and sensilla chaetica. Orco expression was found already in all nymphal stages and was verified in some other tissues which are equipped with chemosensory hairs (mouthparts, tarsi, wings). Together, the results support the notion for a decisive role of Orco in locust olfaction.

  3. Artificial miniaturization causes eggs laid by crowd-reared (gregarious) desert locusts to produce green (solitarious) offspring in the desert locust, Schistocerca gregaria.

    PubMed

    Maeno, Koutaro; Tanaka, Seiji

    2009-09-01

    The mechanism underlying the phase-dependent polyphenism in hatchling body coloration was studied by testing for a possible causal relationship with egg size in the desert locust, Schistocerca gregaria. Crowd-reared (gregarious) females typically produce large, black offspring, whereas females reared in isolation (solitarious) deposit small, green offspring. We first tested for possible genetic differences in the role of egg foam by washing or separating eggs from two strains of locust. No solitarizing effect was found in either of the strains tested, supporting a previous finding, using another laboratory strain, to show that the hatchling body coloration and size are pre-determined in the ovary of the mother and no egg foam factor is involved in the control of the hatchling body coloration. Topical application of fenoxycarb, a juvenile hormone analog (JHA), and implantation of extra corpora allata (CA), taken from Locusta migratoria, caused gregarious female adults of S. gregaria to produce small eggs. Some eggs laid by CA-implanted females produced green hatchlings. All large eggs chosen among those deposited by gregarious females produced black hatchlings. When eggs were either kept on dry filter paper at nearly saturated relative humidity during embryogenesis or pricked with a needle so that some egg yolk was squeezed out, some produced small, green hatchlings. These results suggested that the amount of egg yolk or the availability of yolk material may determine the body coloration of hatchlings.

  4. Tracks of a Giant

    NASA Image and Video Library

    2010-08-25

    The giant, 70-meter-wide antenna at NASA Deep Space Network complex in Goldstone, Calif., tracks a spacecraft on Nov. 17, 2009. This antenna, officially known as Deep Space Station 14, is also nicknamed the Mars antenna.

  5. The Next Giant Step

    NASA Image and Video Library

    Artist Robert McCall painted "The Next Giant Step" in 1979 to commemorate the heroism and courage of spaceflight pioneers. Located in the lobby of Johnson's building 2, the mural depicts America's ...

  6. Silvics of Giant Sequoia

    Treesearch

    C. Phillip Weatherspoon

    1986-01-01

    Ecological relationships-including habitat and life history---of giant sequoia (Sequoiadendron giganteum [Lindl.] Buchholz) in natural stands are summarized. Such silvical information provides an important foundation for sound management of the species.

  7. The Giant Cell.

    ERIC Educational Resources Information Center

    Stockdale, Dennis

    1998-01-01

    Provides directions for the construction of giant plastic cells, including details for building and installing the organelles. Also contains instructions for preparing the ribosomes, nucleolus, nucleus, and mitochondria. (DDR)

  8. Giant Earlobe Epidermoid Cyst

    PubMed Central

    Pérez-Guisado, Joaquín; Scilletta, Alessandra; Cabrera-Sánchez, Emilio; Rioja, Luis F; Perrotta, Rosario

    2012-01-01

    Epidermoid cysts represent the most common cutaneous cysts. They are usually small and benign; however, sometimes they can grow to giant epidermoid cists, and occasionally malignancies develop. Giant epidermoid cysts at the earlobe have never been described but in other locations. We describe a case of a giant epidermoid cyst at the earlobe, a location where such a large cyst has never been reported before. The mass was completely resected and the wound of the pedunculated base was sutured with four stitches of nylon 5/0. Histopathology confirmed the presumptive diagnosis of an epidermoid cyst. Six months after the resection, the patient did not have any relapse of the epidermoid cyst. The earlobe is a potential location for giant epidermoid cysts. Although the clinical diagnosis could be enough, due to the possibility of malignancy and to ensure appropriate diagnosis, we consider that all cysts should be sent to the anatomic pathology laboratory for histological evaluation. PMID:22557855

  9. The Giant Cell.

    ERIC Educational Resources Information Center

    Stockdale, Dennis

    1998-01-01

    Provides directions for the construction of giant plastic cells, including details for building and installing the organelles. Also contains instructions for preparing the ribosomes, nucleolus, nucleus, and mitochondria. (DDR)

  10. Giant Cell Arteritis and Polymyalgia Rheumatica

    MedlinePlus

    ... Controlfamilydoctor.org editorial staff Home Diseases and Conditions Giant Cell Arteritis and Polymyalgia Rheumatica Condition Giant Cell Arteritis and Polymyalgia Rheumatica Share Print Giant ...

  11. Capella: Separating the Giants

    NASA Astrophysics Data System (ADS)

    Young, P. R.; Dupree, A. K.

    2002-01-01

    Images from the Faint Object Camera (FOC) on the Hubble Space Telescope (HST) are used to spatially separate the two giants of Capella (α Aurigae; HD 34029) for the first time at ultraviolet wavelengths. The images were obtained with broadband filters that isolate the wavelength regions 2500-3000 Å and 1300-1500 Å. The cool G8 giant is found to be weaker than the hot G1 giant by factors of around 4 and 17, respectively, in these bands. The latter factor is largely due to the much stronger G1 continuum at short wavelengths. No evidence is found for material lying between the two stars in the images. In addition, the objective prisms of the FOC were used to obtain low-resolution spectra from 1200 to 3000 Å, allowing individual emission lines from each star to be spatially separated. Cool-to-hot star ratios for the emission lines H I Lyα, O I λ1305, Si II λ1816, C II λ1335, He II λ1640, and Si IV λ1393 are presented, showing that the cool giant is weaker than the hot giant by factors of 5-10 in these lines. The O I emission is only a factor of 2.5 weaker in the cool giant, most probably resulting from fluorescence in the extended atmosphere of the cool giant. The line ratios are compared with values derived from International Ultraviolet Explorer and HST/Goddard High Resolution Spectrograph spectra, which could separate the stars spectrally but not spatially. Reasonable agreement is found although the FOC ratios generally imply lower contributions from the cool giant. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

  12. Egg hatching of two locusts, Schistocerca gregaria and Locusta migratoria, in response to light and temperature cycles.

    PubMed

    Nishide, Yudai; Tanaka, Seiji; Saeki, Shinjiro

    2015-05-01

    The present study showed that the eggs of the desert locust, Schistocerca gregaria, and the migratory locust, Locusta migratoria, responded to photoperiod by hatching when placed on sand in the laboratory. S. gregaria mainly hatched during the dark phase and L. migratoria during the light phase. The importance of light as a hatching cue depended on the magnitude of the temperature change during the thermoperiod; photoperiod played a more important role in the control of hatching time in both species when the magnitude of the temperature change was small. In addition, the eggs of the two species that were covered with sand did not respond to photoperiod and hatched during both the light and dark phases, indicating that light did not penetrate through the sand. Because locust eggs are normally laid as egg pods and a foam plug is deposited between the egg mass and the ground surface, we tested a possibility that naturally deposited eggs perceived light through the foam plug. The eggs that were deposited and left undisturbed in the sand hatched during the light and dark phases at similar frequencies. These results suggest that the eggs of both locust species responded to light and controlled their hatching timing accordingly but would not use light as a hatching cue in the field. The evolutionary significance of the ability of eggs to respond to light in these locusts was discussed.

  13. Object-based locust habitat mapping using high-resolution multispectral satellite data in the southern Aral Sea basin

    NASA Astrophysics Data System (ADS)

    Navratil, Peter; Wilps, Hans

    2013-01-01

    Three different object-based image classification techniques are applied to high-resolution satellite data for the mapping of the habitats of Asian migratory locust (Locusta migratoria migratoria) in the southern Aral Sea basin, Uzbekistan. A set of panchromatic and multispectral Système Pour l'Observation de la Terre-5 satellite images was spectrally enhanced by normalized difference vegetation index and tasseled cap transformation and segmented into image objects, which were then classified by three different classification approaches: a rule-based hierarchical fuzzy threshold (HFT) classification method was compared to a supervised nearest neighbor classifier and classification tree analysis by the quick, unbiased, efficient statistical trees algorithm. Special emphasis was laid on the discrimination of locust feeding and breeding habitats due to the significance of this discrimination for practical locust control. Field data on vegetation and land cover, collected at the time of satellite image acquisition, was used to evaluate classification accuracy. The results show that a robust HFT classifier outperformed the two automated procedures by 13% overall accuracy. The classification method allowed a reliable discrimination of locust feeding and breeding habitats, which is of significant importance for the application of the resulting data for an economically and environmentally sound control of locust pests because exact spatial knowledge on the habitat types allows a more effective surveying and use of pesticides.

  14. Recognition and characterization of migratory movements of Australian plague locusts, Chortoicetes terminifera, with an insect monitoring radar

    NASA Astrophysics Data System (ADS)

    Drake, V. Alistair; Wang, Haikou

    2013-01-01

    Two special purpose insect-detecting radar units have operated in inland eastern Australia, in the region where nocturnal migratory movements of Australian plague locusts Chortoicetes terminifera occur, for over 10 years. The fully automatic radars detect individual insects as they fly directly overhead and "interrogate" them to obtain information about their characters (size, shape, and wing beating) and trajectory (speed, direction, and orientation). The character data allow locusts to be distinguished from most other migrant species. A locust index, calculated from the total count of locust-like targets for a night, provides a simple indication of migration intensity. For nights of heavy migration, the variation of numbers, directions, and speeds with both height and time can be examined. Emigration and immigration events can be distinguished, as can "transmigration," the passage overhead of populations originating elsewhere. Movement distances can be inferred, and broad source and (more tentatively) destination regions are identified. Movements were typically over distances of up to 400 km. Interpretation of radar observations requires judgment, and the present two units provide only partial coverage of the locust infestation area, but their capacity to detect major population movements promptly, and to provide information between necessarily infrequent surveys, has proved valuable.

  15. Variable rewards and discrimination ability in an insect herbivore: what and how does a hungry locust learn?

    PubMed

    Behmer, Spencer T; Belt, Corlisa E; Shapiro, Martin S

    2005-09-01

    With the exception of honeybees, there have been few good invertebrate models for associative learning. Grasshoppers and locusts (Orthoptera: Acrididae) possess a number of characteristics that make them excellent candidates for such studies, and in this paper we present a novel protocol, based on a Y-maze, that is specifically designed for studying their learning and choice behaviour. Three separate experiments were conducted using individual gregarious forms of the desert locust, Schistocerca gregaria. In our first experiment, coloured arms of a two-sided Y-maze provided a large or small amount of wheat for nine choice-trials. In the second experiment, locusts discriminated odours with wheat rewards for nine choice-trials. The odour-wheat reward combinations were then reversed for an additional nine choice-trials. For the third experiment, the locusts again discriminated odours, but here we used artificial foods and the rewards differed in their concentration of protein and digestible carbohydrate. The results indicate that, in addition to showing good acquisition of choice performance, the locusts also took less time to reach the larger-rewarded option. The data indicate that our protocol is highly sensitive for recording choice behaviour in acridids and reveals the potential they have for advancing our current understanding of associative learning and the field of learning in general.

  16. Giant congenital melanocytic nevus.

    PubMed

    Viana, Ana Carolina Leite; Gontijo, Bernardo; Bittencourt, Flávia Vasques

    2013-01-01

    Giant congenital melanocytic nevus is usually defined as a melanocytic lesion present at birth that will reach a diameter ≥ 20 cm in adulthood. Its incidence is estimated in <1:20,000 newborns. Despite its rarity, this lesion is important because it may associate with severe complications such as malignant melanoma, affect the central nervous system (neurocutaneous melanosis), and have major psychosocial impact on the patient and his family due to its unsightly appearance. Giant congenital melanocytic nevus generally presents as a brown lesion, with flat or mammilated surface, well-demarcated borders and hypertrichosis. Congenital melanocytic nevus is primarily a clinical diagnosis. However, congenital nevi are histologically distinguished from acquired nevi mainly by their larger size, the spread of the nevus cells to the deep layers of the skin and by their more varied architecture and morphology. Although giant congenital melanocytic nevus is recognized as a risk factor for the development of melanoma, the precise magnitude of this risk is still controversial. The estimated lifetime risk of developing melanoma varies from 5 to 10%. On account of these uncertainties and the size of the lesions, the management of giant congenital melanocytic nevus needs individualization. Treatment may include surgical and non-surgical procedures, psychological intervention and/or clinical follow-up, with special attention to changes in color, texture or on the surface of the lesion. The only absolute indication for surgery in giant congenital melanocytic nevus is the development of a malignant neoplasm on the lesion.

  17. Giant congenital melanocytic nevus*

    PubMed Central

    Viana, Ana Carolina Leite; Gontijo, Bernardo; Bittencourt, Flávia Vasques

    2013-01-01

    Giant congenital melanocytic nevus is usually defined as a melanocytic lesion present at birth that will reach a diameter ≥ 20 cm in adulthood. Its incidence is estimated in <1:20,000 newborns. Despite its rarity, this lesion is important because it may associate with severe complications such as malignant melanoma, affect the central nervous system (neurocutaneous melanosis), and have major psychosocial impact on the patient and his family due to its unsightly appearance. Giant congenital melanocytic nevus generally presents as a brown lesion, with flat or mammilated surface, well-demarcated borders and hypertrichosis. Congenital melanocytic nevus is primarily a clinical diagnosis. However, congenital nevi are histologically distinguished from acquired nevi mainly by their larger size, the spread of the nevus cells to the deep layers of the skin and by their more varied architecture and morphology. Although giant congenital melanocytic nevus is recognized as a risk factor for the development of melanoma, the precise magnitude of this risk is still controversial. The estimated lifetime risk of developing melanoma varies from 5 to 10%. On account of these uncertainties and the size of the lesions, the management of giant congenital melanocytic nevus needs individualization. Treatment may include surgical and non-surgical procedures, psychological intervention and/or clinical follow-up, with special attention to changes in color, texture or on the surface of the lesion. The only absolute indication for surgery in giant congenital melanocytic nevus is the development of a malignant neoplasm on the lesion. PMID:24474093

  18. Giant star seismology

    NASA Astrophysics Data System (ADS)

    Hekker, S.; Christensen-Dalsgaard, J.

    2017-06-01

    The internal properties of stars in the red-giant phase undergo significant changes on relatively short timescales. Long near-uninterrupted high-precision photometric timeseries observations from dedicated space missions such as CoRoT and Kepler have provided seismic inferences of the global and internal properties of a large number of evolved stars, including red giants. These inferences are confronted with predictions from theoretical models to improve our understanding of stellar structure and evolution. Our knowledge and understanding of red giants have indeed increased tremendously using these seismic inferences, and we anticipate that more information is still hidden in the data. Unraveling this will further improve our understanding of stellar evolution. This will also have significant impact on our knowledge of the Milky Way Galaxy as well as on exo-planet host stars. The latter is important for our understanding of the formation and structure of planetary systems.

  19. Locusts as model organisms in which to study immunogen-induced anorectic behaviour.

    PubMed

    Goldsworthy, Graham

    2010-08-01

    When injected into adult or nymphal Locusta that have been deprived of food for 2h, immunogens such as laminarin and bacterial LPS can induce an almost immediate dose-dependent state of anorexia for at least 1h. Such anorexia is a component of a medley of physiological and behavioural changes called collectively 'sickness behaviour' that occurs in a wide range of animals in response to infection or immune challenge. Sub-optimal amounts of injected laminarin allow some locusts to feed, but with a longer latency than in controls, although the length of the first meal is unaffected. The feeding behaviour of fifth instar nymphs is more sensitive to laminarin than that of adults, but both stages respond to amounts of immunogen that are lower than those required to activate the phenoloxidase cascade. Injection of adipokinetic hormone (AKH) before the period of food deprivation prevents the anorexigenic action of the laminarin in adults but not in nymphs. It is argued that the effect of the AKH may be indirect, through its lipid-mobilising action. The insecticide pymetrozine increases the latency to feed but also reduces the length of the first meal, and its anorexigenic activity is not affected by injection of AKH. The present data support the concept that laminarin-induced anorexia involves a central lack of motivation to eat, rather than a 'stop eating' signal. Others have shown that the mechanism of action of pymetrozine involves the serotonergic system and can be blocked by mianserin, so it is intriguing that in the present study injection of mianserin prior to that of laminarin modulates the anorexigenic effect of the immunogen. This suggests that biogenic amines are involved in the control of appetitive behaviour in locusts, as they are in vertebrates. The possible usefulness of the locust model in studying sickness-induced anorexia is discussed briefly. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  20. A novel type of microglomerular synaptic complex in the polarization vision pathway of the locust brain.

    PubMed

    Träger, Ulrike; Wagner, Robert; Bausenwein, Bernhard; Homberg, Uwe

    2008-01-10

    The lateral accessory lobes (LALs) are prominent integration centers in the insect brain. In the desert locust Schistocerca gregaria, they are connected with the anterior optic tubercles (AOTus), with the central complex, and with the ventral nerve cord. Two subcompartments of the LALs, the lateral triangle and the median olive, are easily recognized by their prominent granular texture. Both areas are part of the polarization vision pathway in the locust brain; they receive input from projection neurons of the AOTu and are the site of presumed dendritic arborizations of tangential neurons of the lower division of the central body. Both types of neuron are sensitive to polarized light and most likely play a role in sky compass navigation of the locust. We show here that neurons from the AOTu and tangential neurons of the central body form large microglomerular contacts in the median olive and lateral triangle. Presynaptic elements from the AOTu end in small numbers of large cup-shaped terminals. These cups enclose many small gamma-aminobutyric acid (GABA)-immunoreactive (-ir) profiles from tangential neurons of the lower division of the central body. Each cup-shaped profile makes numerous (>150) dyadic output synapses with the small postsynaptic GABA-ir profiles. No synaptic connections were found between the small core profiles. The microglomerular organization of the median olive and lateral triangle is unlike that of any other synaptic microglomeruli reported for the insect brain. It might provide precise spike timing information possibly used to extract spatial information by comparison of binocular inputs in the central complex. (c) 2007 Wiley-Liss, Inc.

  1. A muscarinic cholinergic mechanism underlies activation of the central pattern generator for locust flight.

    PubMed

    Buhl, Edgar; Schildberger, Klaus; Stevenson, Paul A

    2008-07-01

    A central question in behavioural control is how central pattern generators (CPGs) for locomotion are activated. This paper disputes the key role generally accredited to octopamine in activating the CPG for insect flight. In deafferented locusts, fictive flight was initiated by bath application of the muscarinic agonist pilocarpine, the acetylcholine analogue carbachol, and the acetylcholinesterase blocker eserine, but not by nicotine. Furthermore, in addition to octopamine, various other amines including dopamine, tyramine and histamine all induced fictive flight, but not serotonin or the amine-precursor amino acid tyrosine. However, flight initiation was not reversibly blocked by aminergic antagonists, and was still readily elicited by both natural stimulation (wind) and pilocarpine in reserpinized, amine-depleted locusts. By contrast, the muscarinic antagonists atropine and scopolamine reversibly blocked flight initiated by wind, cholinergic agonists, octopamine, and by selective stimulation of a flight-initiating interneurone (TCG). The short delay from TCG stimulation to flight onset suggests that TCG acts directly on the flight CPG, and accordingly that TCG, or its follower cell within the flight generating circuit, is cholinergic. We conclude that acetylcholine acting via muscarinic receptors is the key neurotransmitter in the mechanism underlying the natural activation of the locust flight CPG. Amines are not essential for this, but must be considered as potential neuromodulators for facilitating flight release and tuning the motor pattern. We speculate that muscarinic activation coupled to aminergic facilitation may be a general feature of behavioural control in insects for ensuring conditional recruitment of individual motor programs in accordance with momentary adaptive requirements.

  2. Effects of chlorpyrifos on glutathione S-transferase in migratory locust, Locusta migratoria.

    PubMed

    Qin, Guohua; Liu, Ting; Guo, Yaping; Zhang, Xueyao; Ma, Enbo; Zhang, Jianzhen

    2014-02-01

    Chlorpyrifos is a typical organophosphate pesticide and is among the most widely used worldwide. The objective of the present investigation was to assess the effect of chlorpyrifos exposure on glutathione S-transferase in Locusta migratoria. In the present study, chlorpyrifos (0.1, 0.2, and 0.4mgg(-1) body weight) was topically applied in the abdomen of locusts. The GST activity, mRNA levels of ten L. migratoria GSTs and protein levels of four representative GSTs were detected. The results showed that chlorpyrifos treatment caused significant decrease of 1,2-dichloro-4-nitrobenzene (DCNB) and p-nitro-benzyl chloride (p-NBC) activities, whereas 1-chloro-2,4-dinitrobenzene (CDNB) activity was not altered in locusts. The mRNA levels of seven L. migratoria GSTs, including LmGSTs2, LmGSTs3, LmGSTs4, LmGSTs5, LmGSTs6, LmGSTt1, and LmGSTu1, were decreased after chlorpyrifos exposure. The protein levels of LmGSTs5, LmGSTt1 and LmGSTu1 were significantly decreased at higher doses of chlorpyrifos. However, chlorpyrifos elevated the mRNA and protein expression of LmGSTd1. It indicated that LmGSTd1 might contribute to the resistance of locust to organophosphate pesticides such as chlorpyrifos, whereas the decrease in other GSTs might be an economic compensation by the insect to differentially regulate the expression of enzymes involved in the detoxification of insecticides on the expense of those that are not.

  3. Ecdysteroid signalling components in metamorphosis and development of the desert locust, Schistocerca gregaria.

    PubMed

    Lenaerts, Cynthia; Van Wielendaele, Pieter; Peeters, Paulien; Vanden Broeck, Jozef; Marchal, Elisabeth

    2016-08-01

    The arthropod-specific hormone family of ecdysteroids plays an important role in regulating diverse physiological processes, such as moulting and metamorphosis, reproduction, diapause and innate immunity. Ecdysteroids mediate their response by binding to a heterodimeric complex of two nuclear receptors, the ecdysone receptor (EcR) and the retinoid-X-receptor/ultraspiracle (RXR/USP). In this study we investigated the role of EcR and RXR in metamorphosis and development of the desert locust, Schistocerca gregaria. The desert locust is a voracious, phytophagous, swarming pest that can ruin crops and harvests in some of the world's poorest countries. A profound knowledge of the ecdysteroid signalling pathway can be used in the development of more target-specific insecticides to combat this harmful plague insect. Here we report an in-depth profiling study of the transcript levels of EcR and RXR, as well as its downstream response genes, in different tissues isolated throughout the last larval stage of a hemimetabolous insect, showing a clear correlation with circulating ecdysteroid titres. Using RNA interference (RNAi), the role of SgEcR/SgRXR in moulting and development was investigated. We have proven the importance of the receptor components for successful moulting of locust nymphs into the adult stage. Some SgEcR/SgRXR knockdown females were arrested in the last larval stage, and 65 % of them initiated vitellogenesis and oocyte maturation, which normally only occurs in adults. Furthermore, our results clearly indicate that at the peak of ecdysteroid synthesis, on day six of the last larval stage, knockdown of SgEcR/SgRXR is affecting the transcript levels of the Halloween genes, Spook, Shadow and Shade. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Eggs and hatchlings variations in desert locusts: phase related characteristics and starvation tolerance

    PubMed Central

    Maeno, Koutaro O.; Piou, Cyril; Ould Babah, Mohamed A.; Nakamura, Satoshi

    2013-01-01

    Locusts are grasshopper species that express phase polyphenism: modifying their behavior, morphology, coloration, life history and physiology in response to crowding. Desert locusts, Schistocerca gregaria, epigenetically modify progeny quality and quantity in response to crowding. Gregarious (crowded) females produce larger but fewer progeny than do solitarious (isolated) ones. The variability of progeny quality within single egg pod and the reasons why gregarious progeny have a better survival rate than solitarious ones remains unclear. This study investigated 1) the effects of rearing density on the variation in egg size within single egg pods 2) the starvation tolerance of hatchlings from mothers with different phases and 3) the physiological differences in hatchling energy reserve. Isolated females produced smaller but more eggs than did crowded ones. The variation in egg size within egg pods was greater in the latter than in the former. A negative relationship between egg size and number of eggs per egg pod was observed for both groups. Under starvation conditions, gregarious hatchlings survived significantly longer than solitarious ones. Among the solitarious hatchlings, the survival time was longer with increased hatchling body size. However, small individuals survived as long as large ones among the gregarious hatchlings. The percentage of water content per fresh body weight was almost equal between the two phases, before and after starvation. In contrast, the percentage of lipid content per dry body weight was significantly higher in gregarious hatchlings than in solitarious ones before starvation, but became almost equal after starvation. These results demonstrate that female locusts not only trade-off to modify their progeny size and number, but also vary progenies' energy reserves. We hypothesize that gregarious females enhance their fitness by producing progeny differently adapted to high environmental variability and particularly to starvation

  5. Regulation of feeding by Neuropeptide F in the desert locust, Schistocerca gregaria.

    PubMed

    Van Wielendaele, Pieter; Dillen, Senne; Zels, Sven; Badisco, Liesbeth; Vanden Broeck, Jozef

    2013-01-01

    Our knowledge on the physiological function of the insect Neuropeptide F (NPF) mostly comes from studies in the fruit fly, Drosophila melanogaster, where NPF was shown to regulate diverse processes, such as feeding, learning and responding to stress. In the desert locust, Schistocerca gregaria, only a truncated form of the "full-length" NPF (the biologically active "trNPF") has been isolated. In this study, we investigated whether this peptide is involved in the regulation of feeding in this orthopteran species. In the S. gregaria EST-database, an NPF-precursor encoding transcript was found. Alignment with other insect NPF-precursors showed relatively highest sequence conservation within the trNPF region (and the flanking dibasic cleavage site), as compared to other regions of the NPF-precursor. Quantitative real-time RT-PCR revealed that the Schgr-NPF-precursor encoding transcript occurs throughout the central nervous system with relatively high transcript levels in the brain, optic lobes and suboesophageal ganglion. It was also detected at relatively high levels in the midgut, which suggests that the encoded peptide also functions in the digestive system. Moreover, Schgr-NPF-transcript levels were notably higher in starved animals than in animals fed ad libitum, while transcript levels were also shown to be regulated after the consumption of a meal. Injection of locust trNPF in adults stimulated food intake, while RNAi knockdown reduced food intake. Furthermore, injection of trNPF in adults stimulated weight increase, while RNAi knockdown reduced weight gain. This effect of trNPF on body weight gain may result from its stimulatory effect on food intake. Taken together, we provide clear evidence for an important role of trNPF in the regulation of feeding in the desert locust, S. gregaria.

  6. An Innocent Giant

    PubMed Central

    Solanki, Lakhan Singh; Dhingra, Mandeep; Raghubanshi, Gunjan; Thami, Gurvinder Pal

    2014-01-01

    A cutaneous horn (cornu cutaneum) is a protrusion from the skin composed of a cornified material. It may be associated with a benign, premalignant, or malignant lesion at the base, masking numerous dermatoses. In a 24-year-old female, a giant cutaneous horn arising from a seborrheic keratosis located on the leg is presented. This case has been reported to emphasize that a giant cutaneous horn may also occur in young patients, even in photoprotected areas, and are not always associated with malignancy. PMID:25484426

  7. Allometric scaling of discontinuous gas exchange patterns in the locust Locusta migratoria throughout ontogeny.

    PubMed

    Snelling, Edward P; Matthews, Philip G D; Seymour, Roger S

    2012-10-01

    The discontinuous gas exchange cycle (DGC) is a three-phase breathing pattern displayed by many insects at rest. The pattern consists of an extended breath-hold period (closed phase), followed by a sequence of rapid gas exchange pulses (flutter phase), and then a period in which respiratory gases move freely between insect and environment (open phase). This study measured CO(2) emission in resting locusts Locusta migratoria throughout ontogeny, in normoxia (21 kPa P(O2)), hypoxia (7 kPa P(O2)) and hyperoxia (40 kPa P(O2)), to determine whether body mass and ambient O(2) affect DGC phase duration. In normoxia, mean CO(2) production rate scales with body mass (M(b); g) according to the allometric power equation , closed phase duration (C; min) scales with body mass according to the equation C=8.0M(b)(0.38±0.29), closed+flutter period (C+F; min) scales with body mass according to the equation C+F=26.6M (0.20±0.25)(b) and open phase duration (O; min) scales with body mass according to the equation O=13.3M(b) (0.23±0.18). Hypoxia results in a shorter C phase and longer O phase across all life stages, whereas hyperoxia elicits shorter C, C+F and O phases across all life stages. The tendency for larger locusts to exhibit longer C and C+F phases might arise if the positive allometric scaling of locust tracheal volume prolongs the time taken to reach the minimum O(2) and maximum CO(2) set-points that determine the duration of these respective periods, whereas an increasingly protracted O phase could reflect the additional time required for larger locusts to expel CO(2) through a relatively longer tracheal pathway. Observed changes in phase duration under hypoxia possibly serve to maximise O(2) uptake from the environment, whereas the response of the DGC to hyperoxia is difficult to explain, but could be affected by elevated levels of reactive oxygen species.

  8. Dissolution Improvement of Atorvastatin Calcium using Modified Locust Bean Gum by the Solid Dispersion Technique.

    PubMed

    Panghal, Dharmila; Nagpal, Manju; Thakur, Gurjeet Singh; Arora, Sandeep

    2014-01-01

    The present research was aimed at the enhancement of the dissolution rate of atorvastatin calcium by the solid dispersion technique using modified locust bean gum. Solid dispersions (SD) using modified locust bean gum were prepared by the modified solvent evaporation method. Other mixtures were also prepared by physical mixing, co-grinding, and the kneading method. The locust bean gum was subjected to heat for modification. The prepared solid dispersions and other mixtures were evaluated for equilibrium solubility studies, content uniformity, FTIR, DSC, XRD, in vitro drug release, and in vivo pharmacodynamic studies. The equilibrium solubility was enhanced in the solid dispersions (in a drug:polymer ratio of 1:6) and other mixtures such as the co-grinding mixture (CGM) and kneading mixture (KM). Maximum dissolution rate was observed in the solid dispersion batch SD3 (i.e. 50% within 15 min) with maximum drug release after 2 h (80%) out of all solid dispersions. The co-grinding mixture also exhibited a significant enhancement in the dissolution rate among the other mixtures. FTIR studies revealed the absence of drug-polymer interaction in the solid dispersions. Minor shifts in the endothermic peaks of the DSC thermograms of SD3 and CGM indicated slight changes in drug crystallinity. XRD studies further confirmed the results of DSC and FTIR. Topological changes were observed in SEM images of SD3 and CGM. In vivo pharmacodynamic studies indicated an improved efficacy of the optimized batch SD3 as compared to the pure drug at a dose of 3 mg/kg/day. Modified locust bean gum can be a promising carrier for solubility enhancement of poorly water-soluble drugs. The lower viscosity and wetting ability of MLBG, reduction in particle size, and decreased crystallinity of the drug are responsible for the dissolution enhancement of atorvastatin. The co-grinding mixture can be a good alternative to solid dispersions prepared by modified solvent evaporation due to its ease of

  9. Dissolution Improvement of Atorvastatin Calcium using Modified Locust Bean Gum by the Solid Dispersion Technique

    PubMed Central

    Panghal, Dharmila; Nagpal, Manju; Thakur, Gurjeet Singh; Arora, Sandeep

    2014-01-01

    The present research was aimed at the enhancement of the dissolution rate of atorvastatin calcium by the solid dispersion technique using modified locust bean gum. Solid dispersions (SD) using modified locust bean gum were prepared by the modified solvent evaporation method. Other mixtures were also prepared by physical mixing, co-grinding, and the kneading method. The locust bean gum was subjected to heat for modification. The prepared solid dispersions and other mixtures were evaluated for equilibrium solubility studies, content uniformity, FTIR, DSC, XRD, in vitro drug release, and in vivo pharmacodynamic studies. The equilibrium solubility was enhanced in the solid dispersions (in a drug:polymer ratio of 1:6) and other mixtures such as the co-grinding mixture (CGM) and kneading mixture (KM). Maximum dissolution rate was observed in the solid dispersion batch SD3 (i.e. 50% within 15 min) with maximum drug release after 2 h (80%) out of all solid dispersions. The co-grinding mixture also exhibited a significant enhancement in the dissolution rate among the other mixtures. FTIR studies revealed the absence of drug-polymer interaction in the solid dispersions. Minor shifts in the endothermic peaks of the DSC thermograms of SD3 and CGM indicated slight changes in drug crystallinity. XRD studies further confirmed the results of DSC and FTIR. Topological changes were observed in SEM images of SD3 and CGM. In vivo pharmacodynamic studies indicated an improved efficacy of the optimized batch SD3 as compared to the pure drug at a dose of 3 mg/kg/day. Modified locust bean gum can be a promising carrier for solubility enhancement of poorly water-soluble drugs. The lower viscosity and wetting ability of MLBG, reduction in particle size, and decreased crystallinity of the drug are responsible for the dissolution enhancement of atorvastatin. The co-grinding mixture can be a good alternative to solid dispersions prepared by modified solvent evaporation due to its ease of

  10. Shadows on a Giant

    NASA Image and Video Library

    2012-07-02

    Saturn rings cast wide shadows on the planet, and the shadow of a moon also graces the gas giant in this scene from NASA Cassini spacecraft. The moon Enceladus is not shown in this view, but it does cast a small, elongated shadow.

  11. Giant scrotal elephantiasis.

    PubMed

    Kuepper, Daniel

    2005-02-01

    How much can a man carry? Penoscrotal elephantiasis is a debilitating syndrome. This is a case report of a patient with giant genital elephantiasis secondary to long-standing lymphogranuloma venereum infection in Ethiopia. Complete surgical resection of the pathologic tissue and penile reconstruction was undertaken with good cosmetic and functional results.

  12. [Giant retroperitoneal liposarcoma].

    PubMed

    Mezzour, Mohamed Hicham; El Messaoudi, Yasser Arafat; Fekak, Hamid; Rabii, Redouane; Marnissi, Farida; Karkouri, Mehdi; Salam, Siham; Iraki, Moulay Ahmed; Joual, Abdenbi; Meziane, Fathi

    2006-02-01

    The authors report a case of giant retroperitoneal liposarcoma. The diagnosis was suspected after scanography and magnetic resonance imaging and confirmed by the histological analysis of the extracted piece after surgical treatment. Postoperative evolution was favourable after one year without recurrence or distant metastasis. The authors discuss the pathologic and therapeutic aspects and the prognosis of retroperitoneal liposarcoma.

  13. Electroluminescence of Giant Stretchability.

    PubMed

    Yang, Can Hui; Chen, Baohong; Zhou, Jinxiong; Chen, Yong Mei; Suo, Zhigang

    2016-06-01

    A new type of electroluminescent device achieves giant stretchability by integrating electronic and ionic components. The device uses phosphor powders as electroluminescent materials, and hydrogels as stretchable and transparent ionic conductors. Subject to cyclic voltage, the phosphor powders luminesce, but the ionic conductors do not electrolyze. The device produces constant luminance when stretched up to an area strain of 1500%.

  14. Discontinuous gas-exchange cycle characteristics are differentially affected by hydration state and energy metabolism in gregarious and solitary desert locusts.

    PubMed

    Talal, Stav; Ayali, Amir; Gefen, Eran

    2015-12-01

    The termination of discontinuous gas exchange cycles (DGCs) in severely dehydrated insects casts doubt on the generality of the hygric hypothesis, which posits that DGCs evolved as a water conservation mechanism. We followed DGC characteristics in the two density-dependent phases of the desert locust Schistocerca gregaria throughout exposure to an experimental treatment of combined dehydration and starvation stress, and subsequent rehydration. We hypothesized that, under stressful conditions, the more stress-resistant gregarious locusts would maintain DGCs longer than solitary locusts. However, we found no phase-specific variations in body water content, water loss rates (total and respiratory) or timing of stress-induced abolishment of DGCs. Likewise, locusts of both phases re-employed DGCs after ingesting comparable volumes of water when rehydrated. Despite comparable water management performances, the effect of exposure to stressful experimental conditions on DGC characteristics varied significantly between gregarious and solitary locusts. Interburst duration, which is affected by the ability to buffer CO2, was significantly reduced in dehydrated solitary locusts compared with gregarious locusts. Moreover, despite similar rehydration levels, only gregarious locusts recovered their initial CO2 accumulation capacity, indicating that cycle characteristics are affected by factors other than haemolymph volume. Haemolymph protein measurements and calculated respiratory exchange ratios suggest that catabolism of haemolymph proteins may contribute to a reduced haemolymph buffering capacity, and thus a compromised ability for CO2 accumulation, in solitary locusts. Nevertheless, DGC was lost at similar hydration states in the two phases, suggesting that DGCs are terminated as a result of inadequate oxygen supply to the tissues.

  15. Structures, properties, and energy-storage mechanisms of the semi-lunar process cuticles in locusts

    NASA Astrophysics Data System (ADS)

    Wan, Chao; Hao, Zhixiu; Feng, Xiqiao

    2016-10-01

    Locusts have excellent jumping and kicking abilities to survive in nature, which are achieved through the energy storage and release processes occurring in cuticles, especially in the semi-lunar processes (SLP) at the femorotibial joints. As yet, however, the strain energy-storage mechanisms of the SLP cuticles remain unclear. To decode this mystery, we investigated the microstructure, material composition, and mechanical properties of the SLP cuticle and its remarkable strain energy-storage mechanisms for jumping and kicking. It is found that the SLP cuticle of adult Locusta migratoria manilensis consists of five main parts that exhibit different microstructural features, material compositions, mechanical properties, and biological functions in storing strain energy. The mechanical properties of these five components are all transversely isotropic and strongly depend on their water contents. Finite element simulations indicate that the two parts of the core region of the SLP cuticle likely make significant contributions to its outstanding strain energy-storage ability. This work deepens our understanding of the locomotion behaviors and superior energy-storage mechanisms of insects such as locusts and is helpful for the design and fabrication of strain energy-storage devices.

  16. The effects of myomodulin and structurally related neuropeptides on skeletal neuromuscular transmission in the locust.

    PubMed

    Evans, P D

    1994-05-01

    1. The modulatory actions of myomodulin A on tension generated in the extensortibiae muscle of the locust hindleg by stimulation of the slow excitatory motoneurone (SETi) depend upon the frequency of stimulation. Myomodulin A has no consistent effect on the tension induced by the fast extensor motoneurone (FETi) or upon the myogenic rhythm present in the extensor. The effects of a range of structurally related neuropeptides have also been assessed. 2. At low frequencies of SETi stimulation (1 Hz and below), the predominant modulatory effects are increases in the amplitude, contraction rate and relaxation rate of twitch tension. At higher frequencies, where twitches summate but tetanus is incomplete (up to 20 Hz), these effects are superimposed upon an increase of maintained tension. 3. The modulatory actions of myomodulin-like peptides show some similarities to and some differences from the modulatory actions of octopamine, proctolin and FMRFamide-like neuropeptides in this preparation, but are likely to be mediated via a distinct set of receptors. 4. The results of the present study, taken together with the localization of myomodulin-like immunoreactivity in specific sets of neurones in the locust nervous system, suggest the presence of a novel modulatory system in insects that uses myomodulin-like neuropeptides. It also indicates that myomodulins, which were first identified in molluscs, may represent another interphyletic family of neuropeptides.

  17. Ultrastructure of identified fast excitatory, slow excitatory and inhibitory neuromuscular junctions in the locust.

    PubMed

    Titmus, M J

    1981-06-01

    The specialized jumping muscle of the locust, the metathoracic extensor tibiae (ETi), is innervated by four physiologically different motoneurons, including FETi, a phasic excitor, SETi, a tonic excitor, and CI, a tonic common inhibitor. FETi neuromuscular junctions were examined in three phasic ETi bundles innervated by FETi. FETi terminals were characterized by patchy contacts on to granular sarcoplasm. The ETi accessory extensor, innervated by both SETi and CI, contains two morphologically different types of axon ending. When this muscle was soaked in horseradish peroxidase, stimulation of SETi led to selective uptake in vesicles in terminals similar to those of FETi axons but containing smaller vesicles, while stimulation by CI caused increased uptake into terminals with more extensive contact directly on to fibrillar sarcoplasm. As has been observed in excitatory and inhibitory synapses in some crustacean and vertebrate nervous systems, the synaptic vesicles in the locust excitatory endings are round and electron-lucent while those in the inhibitory endings are more irregular in shape. The tonic neuromuscular junctions, SETi and CI, are more densely packed with vesicles, larger in cross-sectional area and appear to be of more complex shape than the smaller, vesicle-sparse, phasic FETi terminals. Following long duration stimulation at 10 Hz, the tonic neuromuscular junctions showed little morphological change. FETi endings, which fatigue within minutes at the same stimulation frequency, showed a 20% decrease in synaptic vesicle density and an increase in irregularly shaped membrane inclusions.

  18. Rigidity and Flexibility: The Central Basis of Inter-Leg Coordination in the Locust

    PubMed Central

    Knebel, Daniel; Ayali, Amir; Pflüger, Hans-Joachim; Rillich, Jan

    2017-01-01

    Many motor behaviors, and specifically locomotion, are the product of an intricate interplay between neuronal oscillators known as central pattern generators (CPGs), descending central commands, and sensory feedback loops. The relative contribution of each of these components to the final behavior determines the trade-off between fixed movements and those that are carefully adapted to the environment. Here we sought to decipher the endogenous, default, motor output of the CPG network controlling the locust legs, in the absence of any sensory or descending influences. We induced rhythmic activity in the leg CPGs in isolated nervous system preparations, using different application procedures of the muscarinic agonist pilocarpine. We found that the three thoracic ganglia, each controlling a pair of legs, have different inherent bilateral coupling. Furthermore, we found that the pharmacological activation of one ganglion is sufficient to induce activity in the other, untreated, ganglia. Each ganglion was thus capable to impart its own bilateral inherent pattern onto the other ganglia via a tight synchrony among the ipsilateral CPGs. By cutting a connective and severing the lateral-longitudinal connections, we were able to uncouple the oscillators’ activity. While the bilateral connections demonstrated a high modularity, the ipsilateral CPGs maintained a strict synchronized activity. These findings suggest that the central infrastructure behind locust walking features both rigid elements, which presumably support the generation of stereotypic orchestrated leg movements, and flexible elements, which might provide the central basis for adaptations to the environment and to higher motor commands. PMID:28123358

  19. Acute toxicity of locust insecticides to two indigenous invertebrates from Sahelian temporary ponds.

    PubMed

    Lahr, J; Badji, A; Marquenie, S; Schuiling, E; Ndour, K B; Diallo, A O; Everts, J W

    2001-01-01

    During desert locust plagues large amounts of insecticides are used for control operations. Drift from these treatments and accidental overspraying may contaminate small surface waters such as temporary ponds. The present study describes methods for static acute toxicity tests with two abundant organisms that occur in temporary ponds in the African Sahel region: the fairy shrimp Streptocephalus sudanicus Daday (Branchiopoda, Anostraca, Streptocephalidae) and the backswimmer Anisops sardeus Herrich-Schåffer (Hemiptera, Notonectidae). The organisms were captured in the field and 48-h static toxicity tests were conducted in the laboratory. The assays were used to screen the toxicity of 11 formulated synthetic insecticides used in desert locust control and of spores of the mycopesticide Metarhizium anisopliae var. acridum. Most of the synthetic insecticides tested were highly toxic to both organisms (LC50 or EC50<1 mg/L). Exceptions were the toxicity of diflubenzuron to A. sardeus (moderately toxic: 1

  20. Structural organization of the presynaptic density at identified synapses in the locust central nervous system.

    PubMed

    Leitinger, Gerd; Masich, Sergej; Neumüller, Josef; Pabst, Maria Anna; Pavelka, Margit; Rind, F Claire; Shupliakov, Oleg; Simmons, Peter J; Kolb, Dagmar

    2012-02-01

    In a synaptic active zone, vesicles aggregate around a densely staining structure called the presynaptic density. We focus on its three-dimensional architecture and a major molecular component in the locust. We used electron tomography to study the presynaptic density in synapses made in the brain by identified second-order neuron of the ocelli. Here, vesicles close to the active zone are organized in two rows on either side of the presynaptic density, a level of organization not previously reported in insect central synapses. The row of vesicles that is closest to the density's base includes vesicles docked with the presynaptic membrane and thus presumably ready for release, whereas the outer row of vesicles does not include any that are docked. We show that a locust ortholog of the Drosophila protein Bruchpilot is localized to the presynaptic density, both in the ocellar pathway and compound eye visual neurons. An antibody recognizing the C-terminus of the Bruchpilot ortholog selectively labels filamentous extensions of the presynaptic density that reach out toward vesicles. Previous studies on Bruchpilot have focused on its role in neuromuscular junctions in Drosophila, and our study shows it is also a major functional component of presynaptic densities in the central nervous system of an evolutionarily distant insect. Our study thus reveals Bruchpilot executes similar functions in synapses that can sustain transmission of small graded potentials as well as those relaying large, spike-evoked signals.

  1. Molecular cloning and characterization of the allatotropin precursor and receptor in the desert locust, Schistocerca gregaria

    PubMed Central

    Lismont, Els; Vleugels, Rut; Marchal, Elisabeth; Badisco, Liesbeth; Van Wielendaele, Pieter; Lenaerts, Cynthia; Zels, Sven; Tobe, Stephen S.; Vanden Broeck, Jozef; Verlinden, Heleen

    2015-01-01

    Allatotropins (ATs) are pleiotropic neuropeptides initially isolated from the tobacco hornworm, Manduca sexta. In 2008, the first receptor for AT-like peptides (ATR) was characterized in Bombyx mori. Since then, ATRs have also been characterized in M. sexta, Tribolium castaneum, Aedes aegypti and Bombus terrestris. These receptors show sequence similarity to vertebrate orexin (ORX) receptors. When generating an EST-database of the desert locust (Schistocerca gregaria) central nervous system, we found cDNA sequences encoding the Schgr-AT precursor and a fragment of its putative receptor. This receptor cDNA has now been completed and functionally expressed in mammalian cell lines. Activation of this receptor, designated as Schgr-ATR, by Schgr-AT caused an increase in intracellular calcium ions, as well as cyclic AMP (cAMP), with an EC50 value in the nanomolar range. In addition, the transcript distribution of both the Schgr-AT precursor and Schgr-ATR was investigated by means of quantitative real-time PCR. Moreover, we found more evidence for the myotropic and allatostimulatory actions of Schgr-AT in the desert locust. These data are discussed and situated in a broader context by comparison with literature data on AT and ATR in insects. PMID:25814925

  2. Temperature effects on the tympanal membrane and auditory receptor neurons in the locust.

    PubMed

    Eberhard, Monika J B; Gordon, Shira D; Windmill, James F C; Ronacher, Bernhard

    2014-09-01

    Poikilothermic animals are affected by variations in environmental temperature, as the basic properties of nerve cells and muscles are altered. Nevertheless, insect sensory systems, such as the auditory system, need to function effectively over a wide range of temperatures, as sudden changes of up to 10 °C or more are common. We investigated the performance of auditory receptor neurons and properties of the tympanal membrane of Locusta migratoria in response to temperature changes. Intracellular recordings of receptors at two temperatures (21 and 28 °C) revealed a moderate increase in spike rate with a mean Q10 of 1.4. With rising temperature, the spike rate-intensity-functions exhibited small decreases in thresholds and expansions of the dynamic range, while spike durations decreased. Tympanal membrane displacement, investigated using microscanning laser vibrometry, exhibited a small temperature effect, with a Q10 of 1.2. These findings suggest that locusts are affected by shifts in temperature at the periphery of the auditory pathway, but the effects on spike rate, sensitivity, and tympanal membrane displacement are small. Robust encoding of acoustic signals by only slightly temperature-dependent receptor neurons and almost temperature-independent tympanal membrane properties might enable locusts and grasshoppers to reliably identify sounds in spite of changes of their body temperature.

  3. Structures, properties, and energy-storage mechanisms of the semi-lunar process cuticles in locusts.

    PubMed

    Wan, Chao; Hao, Zhixiu; Feng, Xiqiao

    2016-10-17

    Locusts have excellent jumping and kicking abilities to survive in nature, which are achieved through the energy storage and release processes occurring in cuticles, especially in the semi-lunar processes (SLP) at the femorotibial joints. As yet, however, the strain energy-storage mechanisms of the SLP cuticles remain unclear. To decode this mystery, we investigated the microstructure, material composition, and mechanical properties of the SLP cuticle and its remarkable strain energy-storage mechanisms for jumping and kicking. It is found that the SLP cuticle of adult Locusta migratoria manilensis consists of five main parts that exhibit different microstructural features, material compositions, mechanical properties, and biological functions in storing strain energy. The mechanical properties of these five components are all transversely isotropic and strongly depend on their water contents. Finite element simulations indicate that the two parts of the core region of the SLP cuticle likely make significant contributions to its outstanding strain energy-storage ability. This work deepens our understanding of the locomotion behaviors and superior energy-storage mechanisms of insects such as locusts and is helpful for the design and fabrication of strain energy-storage devices.

  4. Collision-avoidance behaviors of minimally restrained flying locusts to looming stimuli

    PubMed Central

    Chan, R. WM.; Gabbiani, F.

    2013-01-01

    SUMMARY Visually guided collision avoidance is of paramount importance in flight, for instance to allow escape from potential predators. Yet, little is known about the types of collision-avoidance behaviors that may be generated by flying animals in response to an impending visual threat. We studied the behavior of minimally restrained locusts flying in a wind tunnel as they were subjected to looming stimuli presented to the side of the animal, simulating the approach of an object on a collision course. Using high-speed movie recordings, we observed a wide variety of collision-avoidance behaviors including climbs and dives away from – but also towards – the stimulus. In a more restrained setting, we were able to relate kinematic parameters of the flapping wings with yaw changes in the trajectory of the animal. Asymmetric wing flapping was most strongly correlated with changes in yaw, but we also observed a substantial effect of wing deformations. Additionally, the effect of wing deformations on yaw was relatively independent of that of wing asymmetries. Thus, flying locusts exhibit a rich range of collision-avoidance behaviors that depend on several distinct aerodynamic characteristics of wing flapping flight. PMID:23364572

  5. Allatostatin-like immunoreactivity in the abdomen of the locust Schistocerca gregaria.

    PubMed

    Skiebe, Petra; Biserova, Natalia M; Vedenina, Varvara; Börner, Jana; Pflüger, Hans-Joachim

    2006-07-01

    A polyclonal antibody against allatostatin 1 (AST-1) of cockroach Diploptera punctata was used to investigate the distribution of AST-like immunoreactivity within the abdomen of the locust, Schistocerca gregaria. In the abdominal ganglia, AST-like immunoreactivity was found in both cell bodies and neuropile. In ganglia 6 and 7, staining was found in serial homologous cell bodies in anterior dorsolateral and dorsomedial, and posterior ventrolateral and ventromedial locations. In the terminal ganglion, the numerous immunoreactive somata were smaller in size than those in the unfused ganglia. The combination of backfill experiments with immunocytochemistry showed that, in abdominal ganglion 7, one neuron of the ventromedian cell body cluster and two of the ventrolateral cluster innervated the oviduct, which itself was covered with a dense mesh of AST-immunoreactive varicosities. Combining electron microscopy with immunohistochemistry revealed AST-like immunoreactivity in dense-core vesicles located in neurohaemal-like terminals lacking structures normally found in synapses. A mesh of AST-immunoreactive varicosities was also found on the muscles of the spermatheca and the spermathecal duct. In addition, a mesh of strongly stained varicosities was present in the distal perisympathetic organs (neurohaemal organs in the abdomen) and on the lateral heart nerves (a putative neurohaemal release zone). These data indicate that AST is an important neuroactive substance that is probably involved in multiple tasks in the control of the locust abdomen.

  6. Receptive fields of locust brain neurons are matched to polarization patterns of the sky.

    PubMed

    Bech, Miklós; Homberg, Uwe; Pfeiffer, Keram

    2014-09-22

    Many animals, including insects, are able to use celestial cues as a reference for spatial orientation and long-distance navigation [1]. In addition to direct sunlight, the chromatic gradient of the sky and its polarization pattern are suited to serve as orientation cues [2-5]. Atmospheric scattering of sunlight causes a regular pattern of E vectors in the sky, which are arranged along concentric circles around the sun [5, 6]. Although certain insects rely predominantly on sky polarization for spatial orientation [7], it has been argued that detection of celestial E vector orientation may not suffice to differentiate between solar and antisolar directions [8, 9]. We show here that polarization-sensitive (POL) neurons in the brain of the desert locust Schistocerca gregaria can overcome this ambiguity. Extracellular recordings from POL units in the central complex and lateral accessory lobes revealed E vector tunings arranged in concentric circles within large receptive fields, matching the sky polarization pattern at certain solar positions. Modeling of neuronal responses under an idealized sky polarization pattern (Rayleigh sky) suggests that these "matched filter" properties allow locusts to unambiguously determine the solar azimuth by relying solely on the sky polarization pattern for compass navigation.

  7. Fruitless RNAi knockdown in the desert locust, Schistocerca gregaria, influences male fertility.

    PubMed

    Boerjan, Bart; Tobback, Julie; Vandersmissen, Hans Peter; Huybrechts, Roger; Schoofs, Liliane

    2012-02-01

    In Drosophila melanogaster, the male-specific splice isoform of the fruitless gene (Fru(M)) encodes a set of transcription factors that are involved in the regulation of male courtship and copulation. Recent insights from non-drosophilid insects suggest a conserved evolutionary role for the transcription factor Fruitless. In the desert locust, Schistocerca gregaria and the German cockroach, Blatella germanica, both orthopteran insects, a conserved functional role for fruitless has been proposed. Fru specific RNAi knockdown in the third nymphal stage of male Schistocera gregaria delays copulation initiation and results in reduced progeny. In order to identify the origin of the observed phenotypic effects following a fruitless RNAi treatment in the male, we show that the fru knockdown has no detectable effect on spermio- or spermatogenesis and on the transfer of spermatozoa during copulation. Nevertheless, it is clear that the male seminal vesicles contain significantly less spermatozoa after fru RNAi as compared to gfp RNAi controls. We conclude that a lowered male fertility, caused by the fru knockdown in male desert locusts may be the direct cause for the reduction of the progeny numbers in their naïve female copulation partners.

  8. Speed over efficiency: locusts select body temperatures that favour growth rate over efficient nutrient utilization

    PubMed Central

    Miller, Gabriel A.; Clissold, Fiona J.; Mayntz, David; Simpson, Stephen J.

    2009-01-01

    Ectotherms have evolved preferences for particular body temperatures, but the nutritional and life-history consequences of such temperature preferences are not well understood. We measured thermal preferences in Locusta migratoria (migratory locusts) and used a multi-factorial experimental design to investigate relationships between growth/development and macronutrient utilization (conversion of ingesta to body mass) as a function of temperature. A range of macronutrient intake values for insects at 26, 32 and 38°C was achieved by offering individuals high-protein diets, high-carbohydrate diets or a choice between both. Locusts placed in a thermal gradient selected temperatures near 38°C, maximizing rates of weight gain; however, this enhanced growth rate came at the cost of poor protein and carbohydrate utilization. Protein and carbohydrate were equally digested across temperature treatments, but once digested both macronutrients were converted to growth most efficiently at the intermediate temperature (32°C). Body temperature preference thus yielded maximal growth rates at the expense of efficient nutrient utilization. PMID:19625322

  9. Pharmacology of the octopamine receptor from locust central nervous tissue (OAR3).

    PubMed Central

    Roeder, T

    1995-01-01

    1. The present study characterized highly effective agonists from different classes of compounds for the neuronal octopamine receptor (OAR3) of the migratory locust (Locusta migratoria L.). Biogenic amines and phenyliminoimidazolidines (PIIs) were employed for the study of structure-activity relationships. 2. The highest affinity PIIs were predominantly those with substitutions at the positions 2 and 4 of the phenolic ring (e.g. NC 7, KI = 0.3 nM, NC 8, KI = 0.81 nM). Substitutions at these positions always had positive effects on the affinity of the respective agonists. 3. Substitutions at the positions 3, 5 and 6, however, always had negative effects on the affinity. At the position one of the phenolic ring, heterocyclic substituents are preferred. 4. Some PIIs had a more than 30 times higher affinity for OARs than for alpha-adrenoceptors which are the vertebrate homologues of the insect octopamine receptors. 5. The only non-PII with subnanomolar affinity was the aminooxazoline derivative AC 6 (KI = 0.92 nM). 6. A variety of substances with known insecticidal activity such as chlordimeform, demethylchlor-dimeform, amitraz or AC 6 had high affinity for the locust neuronal octopamine receptor. PMID:7712020

  10. Role of the Halloween genes, Spook and Phantom in ecdysteroidogenesis in the desert locust, Schistocerca gregaria.

    PubMed

    Marchal, Elisabeth; Badisco, Liesbeth; Verlinden, Heleen; Vandersmissen, Tim; Van Soest, Sofie; Van Wielendaele, Pieter; Vanden Broeck, Jozef

    2011-09-01

    The functional characterization of the Halloween genes represented a major breakthrough in the elucidation of the ecdysteroid biosynthetic pathway. These genes encode cytochrome P450 enzymes catalyzing the final steps of ecdysteroid biosynthesis in the dipteran Drosophila melanogaster and the Lepidoptera Manduca sexta and Bombyx mori. This is the first report on the identification of two Halloween genes, spook (spo) and phantom (phm), from a hemimetabolous orthopteran insect, the desert locust Schistocerca gregaria. Using q-RT-PCR, their spatial and temporal transcript profiles were analyzed in both final larval stage and adult locusts. The circulating ecdysteroid titers in the hemolymph were measured and found to correlate well with changes in the temporal transcript profiles of spo and phm. Moreover, an RNA interference (RNAi)-based approach was employed to study knockdown effects upon silencing of both transcripts in the fifth larval stage. Circulating ecdysteroid levels were found to be significantly reduced upon dsRNA treatment. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Extra Molting and Selection on Nymphal Growth in the Desert Locust

    PubMed Central

    Piou, Cyril; Jourdan-Pineau, Hélène; Pagès, Christine; Blondin, Laurence; Chapuis, Marie-Pierre

    2016-01-01

    In insects, extra-molting has been viewed as a compensatory mechanism for nymphal growth that contributes to optimize body weight for successful reproduction. However, little is known on the capacity of extra-molting to evolve in natural populations, which limits our understanding of how selection acts on nymphal growth. We used a multi-generational pedigree, individual monitoring and quantitative genetics models to investigate the evolution of extra-molting and its impact on nymphal growth in a solitarious population of the desert locust, Schistocerca gregaria. Growth compensation via extra-molting was observed for 46% of the females, whose adult weight exceeded by 4% that of other females, at a cost of a 22% longer development time. We found a null heritability for body weight threshold only, and the highest and a strongly female-biased heritability for extra molting. Our genetic estimates show that (1) directional selection can act on growth rate, development time and extra-molting to optimize body weight threshold, the target of stabilizing selection, (2) extra-molting can evolve in natural populations, and (3) a genetic conflict, due to sexually antagonistic selection on extra-molting, might prevent its fixation. Finally, we discuss how antagonistic selection between solitarious and gregarious environments and/or genetic correlations between growth and phase traits might also impact the evolution of extra-molting in locusts. PMID:27227885

  12. The scent glands of the male south american locust Schistocerca cancellata, an electron microscope study.

    PubMed

    Hawkes, F; Rzepka, J; Gontrand, G

    1987-01-01

    The male South American locust, Schistocerca cancellata, emits a strong aromatic scent at the time of maturation. This aroma is characteristic of mature adult males living in crowded conditions. In isolated males and in females it is perceptible but faint, while nymphs emit no scent at all. Since dermal glands are numerous in the mature adult but much rarer in nymphs, young imagos and females, it seems likely that the scent is associated with these glands. The scent seems to be a maturation-pheromone, stored and released by these dermal glands. Each gland consists of a gland cell and a duct cell (type 3 gland in the classification of Noirot and Quennedey, (1974)). Each gland cell has a single end-apparatus consisting of an oblong cavity limited by the projecting tips of densely packed microvilli. A duct, dilated to form three successive bulbosities at its distal end, opens in the cavity from which it conveys the secretion to the outside. A network of fibrillar material anchors the duct to the cavity. Reproductive synchrony, beneficial in social insects, seems to be achieved in locusts by the aromatic pheromone released by the glands at the time of maturation.

  13. Enhanced wound healing activity of desert locust (Schistocerca gregaria) vs. shrimp (Penaeus monodon) chitosan based scaffolds.

    PubMed

    Marei, Narguess H; El-Mazny, W; El-Shaer, Aida; Zaki, Kareem Dorri; Hussein, Zahra S; Abd-El-Samie, Emtithal M

    2017-04-01

    Chitosan (CS) has received great attention in tissue engineering, especially in wound healing acceleration. In this study, chitin was isolated from desert locust (Schistocerca gregaria) and shrimp (Penaeus monodon) then deacetylated to chitosan. Then, chitosan was characterized by degree of deacetylation (DD), molecular weight (M.Wt), swelling index (SI), Fourier transform infrared (FTIR) and X ray diffraction (XRD). The chitosan was then casted into 2D scaffolds and was pictured using scanning electron microscope (SEM). In a comparative study, primary cell cultures of neonatal (1-2day old) mice skin tissue, supplemented with 10% fetal calf serum, were seeded onto locust chitosan based scaffolds (LCSBS) and shrimp chitosan based scaffold (SCSBS). Their attachment percentage was determined after 1h. The cell proliferation rate was tested for 5days on LCSBS and SCSBS. Wound healing activity progress of LCSBS and SCSBS was tested in vivo using histopathology, and results revealed that seeded and unseeded LCSBS accelerated healing in contrast to SCSBS. The data demonstrated that LCSBS shows a high degree of biocompatibility in vivo. These results suggest that LCSBS is a potential substitute for the development of low cost implantable materials to accelerate wound healing.

  14. Structural Organization of the Presynaptic Density at Identified Synapses in the Locust Central Nervous System

    PubMed Central

    Leitinger, Gerd; Masich, Sergej; Neumüller, Josef; Pabst, Maria Anna; Pavelka, Margit; Rind, F Claire; Shupliakov, Oleg; Simmons, Peter J; Kolb, Dagmar

    2012-01-01

    In a synaptic active zone, vesicles aggregate around a densely staining structure called the presynaptic density. We focus on its three-dimensional architecture and a major molecular component in the locust. We used electron tomography to study the presynaptic density in synapses made in the brain by identified second-order neuron of the ocelli. Here, vesicles close to the active zone are organized in two rows on either side of the presynaptic density, a level of organization not previously reported in insect central synapses. The row of vesicles that is closest to the density's base includes vesicles docked with the presynaptic membrane and thus presumably ready for release, whereas the outer row of vesicles does not include any that are docked. We show that a locust ortholog of the Drosophila protein Bruchpilot is localized to the presynaptic density, both in the ocellar pathway and compound eye visual neurons. An antibody recognizing the C-terminus of the Bruchpilot ortholog selectively labels filamentous extensions of the presynaptic density that reach out toward vesicles. Previous studies on Bruchpilot have focused on its role in neuromuscular junctions in Drosophila, and our study shows it is also a major functional component of presynaptic densities in the central nervous system of an evolutionarily distant insect. Our study thus reveals Bruchpilot executes similar functions in synapses that can sustain transmission of small graded potentials as well as those relaying large, spike-evoked signals. J. Comp. Neurol. 520:384–400, 2012. © 2011 Wiley Periodicals, Inc. PMID:21826661

  15. Rigidity and Flexibility: The Central Basis of Inter-Leg Coordination in the Locust.

    PubMed

    Knebel, Daniel; Ayali, Amir; Pflüger, Hans-Joachim; Rillich, Jan

    2016-01-01

    Many motor behaviors, and specifically locomotion, are the product of an intricate interplay between neuronal oscillators known as central pattern generators (CPGs), descending central commands, and sensory feedback loops. The relative contribution of each of these components to the final behavior determines the trade-off between fixed movements and those that are carefully adapted to the environment. Here we sought to decipher the endogenous, default, motor output of the CPG network controlling the locust legs, in the absence of any sensory or descending influences. We induced rhythmic activity in the leg CPGs in isolated nervous system preparations, using different application procedures of the muscarinic agonist pilocarpine. We found that the three thoracic ganglia, each controlling a pair of legs, have different inherent bilateral coupling. Furthermore, we found that the pharmacological activation of one ganglion is sufficient to induce activity in the other, untreated, ganglia. Each ganglion was thus capable to impart its own bilateral inherent pattern onto the other ganglia via a tight synchrony among the ipsilateral CPGs. By cutting a connective and severing the lateral-longitudinal connections, we were able to uncouple the oscillators' activity. While the bilateral connections demonstrated a high modularity, the ipsilateral CPGs maintained a strict synchronized activity. These findings suggest that the central infrastructure behind locust walking features both rigid elements, which presumably support the generation of stereotypic orchestrated leg movements, and flexible elements, which might provide the central basis for adaptations to the environment and to higher motor commands.

  16. Structures, properties, and energy-storage mechanisms of the semi-lunar process cuticles in locusts

    PubMed Central

    Wan, Chao; Hao, Zhixiu; Feng, Xiqiao

    2016-01-01

    Locusts have excellent jumping and kicking abilities to survive in nature, which are achieved through the energy storage and release processes occurring in cuticles, especially in the semi-lunar processes (SLP) at the femorotibial joints. As yet, however, the strain energy-storage mechanisms of the SLP cuticles remain unclear. To decode this mystery, we investigated the microstructure, material composition, and mechanical properties of the SLP cuticle and its remarkable strain energy-storage mechanisms for jumping and kicking. It is found that the SLP cuticle of adult Locusta migratoria manilensis consists of five main parts that exhibit different microstructural features, material compositions, mechanical properties, and biological functions in storing strain energy. The mechanical properties of these five components are all transversely isotropic and strongly depend on their water contents. Finite element simulations indicate that the two parts of the core region of the SLP cuticle likely make significant contributions to its outstanding strain energy-storage ability. This work deepens our understanding of the locomotion behaviors and superior energy-storage mechanisms of insects such as locusts and is helpful for the design and fabrication of strain energy-storage devices. PMID:27748460

  17. The neuropeptide F/nitric oxide pathway is essential for shaping locomotor plasticity underlying locust phase transition

    PubMed Central

    Hou, Li; Yang, Pengcheng; Jiang, Feng; Liu, Qing; Wang, Xianhui; Kang, Le

    2017-01-01

    Behavioral plasticity is widespread in swarming animals, but little is known about its underlying neural and molecular mechanisms. Here, we report that a neuropeptide F (NPF)/nitric oxide (NO) pathway plays a critical role in the locomotor plasticity of swarming migratory locusts. The transcripts encoding two related neuropeptides, NPF1a and NPF2, show reduced levels during crowding, and the transcript levels of NPF1a and NPF2 receptors significantly increase during locust isolation. Both NPF1a and NPF2 have suppressive effects on phase-related locomotor activity. A key downstream mediator for both NPFs is nitric oxide synthase (NOS), which regulates phase-related locomotor activity by controlling NO synthesis in the locust brain. Mechanistically, NPF1a and NPF2 modify NOS activity by separately suppressing its phosphorylation and by lowering its transcript level, effects that are mediated by their respective receptors. Our results uncover a hierarchical neurochemical mechanism underlying behavioral plasticity in the swarming locust and provide insights into the NPF/NO axis. DOI: http://dx.doi.org/10.7554/eLife.22526.001 PMID:28346142

  18. Potential of the Desert Locust Schistocerca gregaria (Orthoptera: Acrididae) as an Unconventional Source of Dietary and Therapeutic Sterols.

    PubMed

    Cheseto, Xavier; Kuate, Serge Philibert; Tchouassi, David P; Ndung'u, Mary; Teal, Peter E A; Torto, Baldwyn

    2015-01-01

    Insects are increasingly being recognized not only as a source of food to feed the ever growing world population but also as potential sources of new products and therapeutic agents, among which are sterols. In this study, we sought to profile sterols and their derivatives present in the desert locust, Schistocerca gregaria, focusing on those with potential importance as dietary and therapeutic components for humans. Using coupled gas chromatography-mass spectrometry (GC-MS), we analyzed and compared the quantities of sterols in the different sections of the gut and tissues of the locust. In the gut, we identified 34 sterols which showed a patchy distribution, but with the highest composition in the foregut (55%) followed by midgut (31%) and hindgut (14%). Fed ad libitum on wheat seedlings, five sterols unique to the insect were detected. These sterols were identified as 7-dehydrocholesterol, desmosterol, fucosterol, (3β, 5α) cholesta-8, 14, 24-trien-3-ol, 4, 4-dimethyl, and (3β, 20R) cholesta-5, 24-dien-3, 20-diol with the first three having known health benefits in humans. Incubation of the fore-, mid- and hindgut with cholesterol-[4-13C] yielded eight derivatives, three of these were detected in the gut of the desert locust after it had consumed the vegetative diet but were not detected in the diet. Our study shows that the desert locust ingests phytosterols from a vegetative diet and, amplifies and metabolizes them into derivatives with potential salutary benefits and we discuss our findings in this context.

  19. Comparing watershed black locust afforestation and natural revegetation impacts on soil nitrogen on the Loess Plateau of China

    NASA Astrophysics Data System (ADS)

    Jin, Zhao; Li, Xiangru; Wang, Yunqiang; Wang, Yi; Wang, Kaibo; Cui, Buli

    2016-04-01

    This study examined a pair of neighbouring small watersheds with contrasting vegetations: artificial forestland and natural grassland. Since 1954, afforestation which mainly planted with black locust has been conducted in one of these watersheds and natural revegetation in the other. The differences in soil total N, nitrate, ammonium, foliar litterfall δ15N and dual stable isotopes of δ15N and δ18O in soil nitrate were investigated in the two ecosystems. Results showed that there was no significant difference in soil total N storage between the two ecosystems, but the black locust forestland presented higher soil nitrate than the grassland. Moreover, the foliar litterfall N content and δ15N of the forestland were significant higher than the grassland. These results indicate that 60 years of watershed black locust afforestation have increased soil N availability. The higher nitrate in the forestland was attributed to the biological N fixation of black locust and difference in ecosystem hydrology. The dual stable isotopes of δ15N and δ18O revealed that the two ecosystems had different sources of soil nitrate. The soil nitrate in the forestland was likely derived from soil N nitrification, while the soil nitrate in the grassland was probably derived from the legacy of NO3- fertiliser.

  20. Individual Pause-and-Go Motion Is Instrumental to the Formation and Maintenance of Swarms of Marching Locust Nymphs

    PubMed Central

    Ariel, Gil; Ophir, Yotam; Levi, Sagi; Ben-Jacob, Eshel; Ayali, Amir

    2014-01-01

    The principal interactions leading to the emergence of order in swarms of marching locust nymphs was studied both experimentally, using small groups of marching locusts in the lab, and using computer simulations. We utilized a custom tracking algorithm to reveal fundamental animal-animal interactions leading to collective motion. Uncovering this behavior introduced a new agent-based modeling approach in which pause-and-go motion is pivotal. The behavioral and modeling findings are largely based on motion-related visual sensory inputs obtained by the individual locust. Results suggest a generic principle, in which intermittent animal motion can be considered as a sequence of individual decisions as animals repeatedly reassess their situation and decide whether or not to swarm. This interpretation implies, among other things, some generic characteristics regarding the build-up and emergence of collective order in swarms: in particular, that order and disorder are generic meta-stable states of the system, suggesting that the emergence of order is kinetic and does not necessarily require external environmental changes. This work calls for further experimental as well as theoretical investigation of the neural mechanisms underlying locust coordinative behavior. PMID:24988464

  1. A Survey Level Report of the Below Locust Creek Landside Ditch Cleancut Project, Craighead and Greene Counties, Arkansas

    DTIC Science & Technology

    1980-12-01

    Resources ............ ........ 61 Table 11. Ground Surface Visibility Conditions Recorded at Below Locust Creek Landside Ditch Cleanout Project...survey level of investigation shall include (a) literature search, records review, and intensive on-the- ground examination and testing to determine...intensity of tropical storms due to variations in sea surface temperatures (Wendland 1977). Some apparent changes within the Early and Middle Woodland

  2. Identification and Characterization of Two “Sensory Neuron Membrane Proteins” (SNMPs) of the Desert Locust, Schistocerca gregaria (Orthoptera: Acrididae)

    PubMed Central

    Jiang, Xingcong; Pregitzer, Pablo; Grosse-Wilde, Ewald; Breer, Heinz; Krieger, Jürgen

    2016-01-01

    Pheromone-responsive neurons of insects not only require specific receptors but in addition several auxiliary components, including the “sensory neuron membrane protein,” SNMP. Accordingly, SNMP is considered as a marker for neurons responding to pheromones. For the desert locust Schistocerca gregaria, it is known that the behavior, including aggregation behavior and courtship inhibition, is largely controlled by pheromones. However, little is known about pheromones, their receptors, and the pheromone-responsive cells in locusts. In this study, we have identified two SNMP subtypes, SNMP1 and SNMP2, and compared their phylogenetic relationship and primary structure motifs with SNMPs from other species. Both SNMPs were found in chemosensory tissues, especially the antennae. Employing double in situ hybridization, we identified and localized the SNMP-expressing cells in the antennae. Cells expressing SNMP1 were localized to sensilla trichodea but also to sensilla basiconica, which in locust respond to pheromones. One or a few cells express SNMP1 within the multineuron clusters from sensilla basiconica, whereas the SNMP2 subtype was expressed in cells surrounding the neuron clusters, possibly supporting cells. Based on the finding that SNMP1 is expressed in distinct neurons under chemosensory sensilla, it is conceivable that these cells may represent pheromone-responsive neurons of the desert locust. PMID:27012870

  3. Spectroscopic analysis of the role of extractives on heat-induced discoloration of black locust (Robinia pseudoacacia)

    Treesearch

    Yao Chen; Yongming Fan; Jianmin Gao; Mandla A. Tshabalala; Nicole M. Stark

    2012-01-01

    To investigate the role of extractives on heat-induced discoloration of wood, samples of black locust (Robinia pseudoacacia) wood flour were extracted with various solvents prior to heat-treatment. Analysis of their color parameters and chromophoric structures showed that the chroma value of the unextracted sample decreased while that of the...

  4. Comparing watershed black locust afforestation and natural revegetation impacts on soil nitrogen on the Loess Plateau of China

    PubMed Central

    Jin, Zhao; Li, Xiangru; Wang, Yunqiang; Wang, Yi; Wang, Kaibo; Cui, Buli

    2016-01-01

    This study examined a pair of neighbouring small watersheds with contrasting vegetations: artificial forestland and natural grassland. Since 1954, afforestation which mainly planted with black locust has been conducted in one of these watersheds and natural revegetation in the other. The differences in soil total N, nitrate, ammonium, foliar litterfall δ15N and dual stable isotopes of δ15N and δ18O in soil nitrate were investigated in the two ecosystems. Results showed that there was no significant difference in soil total N storage between the two ecosystems, but the black locust forestland presented higher soil nitrate than the grassland. Moreover, the foliar litterfall N content and δ15N of the forestland were significant higher than the grassland. These results indicate that 60 years of watershed black locust afforestation have increased soil N availability. The higher nitrate in the forestland was attributed to the biological N fixation of black locust and difference in ecosystem hydrology. The dual stable isotopes of δ15N and δ18O revealed that the two ecosystems had different sources of soil nitrate. The soil nitrate in the forestland was likely derived from soil N nitrification, while the soil nitrate in the grassland was probably derived from the legacy of NO3− fertiliser. PMID:27112514

  5. Reconstruction of a 1,910-y-long locust series reveals consistent associations with climate fluctuations in China

    PubMed Central

    Tian, Huidong; Stige, Leif C.; Cazelles, Bernard; Kausrud, Kyrre Linne; Svarverud, Rune; Stenseth, Nils C.; Zhang, Zhibin

    2011-01-01

    It is becoming increasingly clear that global warming is taking place; however, its long-term effects on biological populations are largely unknown due to lack of long-term data. Here, we reconstructed a 1,910-y-long time series of outbreaks of Oriental migratory locusts (Locusta migratoria manilensis) in China, on the basis of information extracted from >8,000 historical documents. First by analyzing the most recent period with the best data quality using generalized additive models, we found statistically significant associations between the reconstructed locust abundance and indexes of precipitation and temperature at both annual (A.D. 1512–1911) and decadal (A.D. 1000–1900) scales: There were more locusts under dry and cold conditions and when locust abundance was high in the preceding year or decade. Second, by exploring locust–environment correlations using a 200-y moving window, we tested whether these associations also hold further back in time. The locust–precipitation correlation was found to hold at least as far back as to A.D. 500, supporting the robustness of this link as well as the quality of both reconstructions. The locust–temperature correlation was weaker and less consistent, which may reflect this link being indirect and thus more easily moderated by other factors. We anticipate that further analysis of this unique time series now available to the scientific community will continue to provide insights into biological consequences of climate change in the years to come. PMID:21876131

  6. Types, numbers and distribution of synapses on the dendritic tree of an identified visual interneuron in the brain of the locust.

    PubMed

    Killmann, F; Gras, H; Schürmann, F

    1999-06-01

    The descending contralateral movement detector (DCMD), an identified descending interneuron in the brain of the locust Schistocerca gregaria has been investigated by using light and electron microscopy. We describe the fine structure, distribution and numbers of synapses that it receives from another identified brain neuron, the lobular giant movement detector (LGMD), and from unidentified neurons. The DCMD dendrites emerging from the integrative segment vary in form and number between individuals and sexes but always form a flattened dendritic domain. The arborizations and the integrative segment appear to be exclusively postsynaptic. Two types of synaptic contacts (Type 1 and 2) onto the DCMD can be discerned as having either round (Type 1) or pleiomorphic synaptic vesicles (Type 2) and by large (Type 1) or small (Type 2) subsynaptic appositions. Contact zones of Type 1 synapses are smaller than those of Type 2. LGMD-synapses are of Type 1 and occur intermingled with presynaptic sites of unidentified units. Some branches of the DCMD receiving input from unidentified units are devoid of contacting LGMD processes. Synapses of both types are randomly distributed over the DCMD integrative segment and at fibres with similar sizes. Type 1 synapses are much more frequent than Type 2 synapses and their number is negatively correlated with fibre diameter. For a whole DCMD dendritic arborization, a total of 8500 active zones of chemical synapses has been calculated, including a minimum of 2250 LGMD-synapses and about 1000 Type 2 synapses. The DCMD may thus receive a considerable amount of input from as yet unidentified neurons.

  7. Estimation of biological nitrogen fixation by black locust in short-rotation forests using natural 15N abundance method

    NASA Astrophysics Data System (ADS)

    Veste, M.; Böhm, C.; Quinckenstein, A.; Freese, D.

    2012-04-01

    The importance of short rotation forests and agroforestry systems for woody biomass production for bioenergy will increase in Central Europe within the next decades. In this context, black locust (Robinia pseudoacacia) has a high growth potential especially at marginal, drought-susceptible sites such as occur in Brandenburg State (Eastern Germany). As a pioneer tree species black locust grows under a wide range of site conditions. The native range of black locust in Northern America is classified by a humid to sub-humid climate with a mean annual precipitation of 1020 to 1830 mm. In Central and Eastern Europe, this species is cultivated in a more continental climate with an annual precipitation often below 600 mm. Therefore, black locust is known to be relatively drought tolerant compared to other temperate, deciduous tree species. Because of its N2-fixation ability black locust plays generally an important role for the improvement of soil fertility. This effect is of particular interest at marginal sites in the post-mining landscapes. In order to estimate the N2-fixation potential of black locust at marginal sites leaf samples were taken from black locust trees in short rotation plantations planted between 1995 and 2007 in post-mining sites south of Cottbus (Brandenburg, NE Germany). The variation of the natural 15N abundance was measured to evaluate the biological nitrogen fixation. The nitrogen derived from the atmosphere can be calculated using a two-pool model from the quotient of the natural 15N abundances of the N2-fixing plant and the plant available soil N. Because representatively determining the plant available soil N is difficult, a non-N2-fixing reference plant growing at the same site with a similar root system and temporal N uptake pattern to the N2-fixing plant is often used. In our case we used red oak (Quercus rubra) as a reference. The average nitrogen content in the leaves of black locust ranged from 3.1% (C/N 14.8) in 15 years old trees to 3

  8. Ice Giant Exploration

    NASA Astrophysics Data System (ADS)

    Rymer, A. M.; Arridge, C. S.; Masters, A.; Turtle, E. P.; Simon, A. A.; Hofstadter, M. D.; Turrini, D.; Politi, R.

    2015-12-01

    The Ice Giants in our solar system, Uranus and Neptune, are fundamentally different from their Gas Giant siblings Jupiter and Saturn, from the different proportions of rock and ice to the configuration of their planetary magnetic fields. Kepler space telescope discoveries of exo-planets indicate that planets of this type are among the most ubiquitous universally and therefore a future mission to explore the nature of the Ice Giants in our own solar system will provide insights into the nature of extra-solar system objects in general. Uranus has the smallest self- luminosity of all the planets, potentially related to catastrophic events early in the planet's history, which also may explain Uranus' large obliquity. Uranus' atmosphere is subject to extreme seasonal forcing making it unique in the Solar System. Neptune is also unique in a number of ways, notably its large moon Triton which is likely a captured Kuiper Belt Object and one of only two moons in the solar system with a robustly collisional atmosphere. Similar to Uranus, the angle between the solar wind and the magnetic dipole axis is subject to large-amplitude variations on both diurnal and seasonal timescales, but peculiarly it has one of the quietest magnetospheres of the solar system, at least according to Voyager 2, the only spacecraft to encounter Neptune to date. A comprehensive mission, as advocated in the Decadal Survey, would provide enormous science return but is also challenging and expensive. In this presentation we will discuss mission scenarios and suggest how collaboration between disciplines and internationally can help us to pursue a mission that includes Ice Giant exploration.

  9. Giant cell arteritis

    PubMed Central

    Calvo-Romero, J

    2003-01-01

    Giant cell arteritis (GCA), temporal arteritis or Horton's arteritis, is a systemic vasculitis which involves large and medium sized vessels, especially the extracranial branches of the carotid arteries, in persons usually older than 50 years. Permanent visual loss, ischaemic strokes, and thoracic and abdominal aortic aneurysms are feared complications of GCA. The treatment consists of high dose steroids. Mortality, with a correct treatment, in patients with GCA seems to be similar that of controls. PMID:13679546

  10. Giant Cell Arteritis.

    PubMed

    Hoffman, Gary S

    2016-11-01

    This issue provides a clinical overview of giant cell arteritis, focusing on diagnosis, treatment, and practice improvement. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of additional science writers and physician writers.

  11. Molecular and functional analysis of UDP-N-acetylglucosamine Pyrophosphorylases from the Migratory Locust, Locusta migratoria.

    PubMed

    Liu, Xiaojian; Li, Feng; Li, Daqi; Ma, Enbo; Zhang, Wenqing; Zhu, Kun Yan; Zhang, Jianzhen

    2013-01-01

    UDP-N-acetylglucosamine pyrophosphorylases (UAP) function in the formation of extracellular matrix by producing N-acetylglucosamine (GlcNAc) residues needed for chitin biosynthesis and protein glycosylation. Herein, we report two UAP cDNA's derived from two different genes (LmUAP1 and LmUAP2) in the migratory locust Locusta migratoria. Both the cDNA and their deduced amino acid sequences showed about 70% identities between the two genes. Phylogenetic analysis suggests that LmUAP1 and LmUAP2 derive from a relatively recent gene duplication event. Both LmUAP1 and LmUAP2 were widely expressed in all the major tissues besides chitin-containing tissues. However, the two genes exhibited different developmental expression patterns. High expression of LmUAP1 was detected during early embryogenesis, then decreased greatly, and slowly increased before egg hatch. During nymphal development, the highest expression of LmUAP1 appeared just after molting but declined in each inter-molting period and then increased before molting to the next stage, whereas LmUAP2 was more consistently expressed throughout all these stages. When the early second- and fifth-instar nymphs (1-day-old) were injected with LmUAP1 double-stranded RNA (dsRNA), 100% mortality was observed 2 days after the injection. When the middle second- and fifth-instar nymphs (3- to 4-day-old) were injected with LmUAP1 dsRNA, 100% mortality was observed during their next molting process. In contrast, when the insects at the same stages were injected with LmUAP2 dsRNA, these insects were able to develop normally and molt to the next stage successfully. It is presumed that the lethality caused by RNAi of LmUAP1 is due to reduced chitin biosynthesis of the integument and midgut, whereas LmUAP2 is not essential for locust development at least in nymph stage. This study is expected to help better understand different functions of UAP1 and UAP2 in the locust and other insect species.

  12. Molecular and Functional Analysis of UDP-N-Acetylglucosamine Pyrophosphorylases from the Migratory Locust, Locusta migratoria

    PubMed Central

    Li, Daqi; Ma, Enbo; Zhang, Wenqing; Zhu, Kun Yan; Zhang, Jianzhen

    2013-01-01

    UDP-N-acetylglucosamine pyrophosphorylases (UAP) function in the formation of extracellular matrix by producing N-acetylglucosamine (GlcNAc) residues needed for chitin biosynthesis and protein glycosylation. Herein, we report two UAP cDNA’s derived from two different genes (LmUAP1 and LmUAP2) in the migratory locust Locusta migratoria. Both the cDNA and their deduced amino acid sequences showed about 70% identities between the two genes. Phylogenetic analysis suggests that LmUAP1 and LmUAP2 derive from a relatively recent gene duplication event. Both LmUAP1 and LmUAP2 were widely expressed in all the major tissues besides chitin-containing tissues. However, the two genes exhibited different developmental expression patterns. High expression of LmUAP1 was detected during early embryogenesis, then decreased greatly, and slowly increased before egg hatch. During nymphal development, the highest expression of LmUAP1 appeared just after molting but declined in each inter-molting period and then increased before molting to the next stage, whereas LmUAP2 was more consistently expressed throughout all these stages. When the early second- and fifth-instar nymphs (1-day-old) were injected with LmUAP1 double-stranded RNA (dsRNA), 100% mortality was observed 2 days after the injection. When the middle second- and fifth-instar nymphs (3- to 4-day-old) were injected with LmUAP1 dsRNA, 100% mortality was observed during their next molting process. In contrast, when the insects at the same stages were injected with LmUAP2 dsRNA, these insects were able to develop normally and molt to the next stage successfully. It is presumed that the lethality caused by RNAi of LmUAP1 is due to reduced chitin biosynthesis of the integument and midgut, whereas LmUAP2 is not essential for locust development at least in nymph stage. This study is expected to help better understand different functions of UAP1 and UAP2 in the locust and other insect species. PMID:23977188

  13. The effects of temperature and body mass on jump performance of the locust Locusta migratoria.

    PubMed

    Snelling, Edward P; Becker, Christie L; Seymour, Roger S

    2013-01-01

    Locusts jump by rapidly releasing energy from cuticular springs built into the hind femur that deform when the femur muscle contracts. This study is the first to examine the effect of temperature on jump energy at each life stage of any orthopteran. Ballistics and high-speed cinematography were used to quantify the energy, distance, and take-off angle of the jump at 15, 25, and 35°C in the locust Locusta migratoria. Allometric analysis across the five juvenile stages at 35°C reveals that jump distance (D; m) scales with body mass (M; g) according to the power equation D = 0.35M (0.17±0.08 (95% CI)), jump take-off angle (A; degrees) scales as A = 52.5M (0.00±0.06), and jump energy (E; mJ per jump) scales as E = 1.91M (1.14±0.09). Temperature has no significant effect on the exponent of these relationships, and only a modest effect on the elevation, with an overall Q10 of 1.08 for jump distance and 1.09 for jump energy. On average, adults jump 87% farther and with 74% more energy than predicted based on juvenile scaling data. The positive allometric scaling of jump distance and jump energy across the juvenile life stages is likely facilitated by the concomitant relative increase in the total length (L f+t; mm) of the femur and tibia of the hind leg, L f+t = 34.9M (0.37±0.02). The weak temperature-dependence of jump performance can be traced to the maximum tension of the hind femur muscle and the energy storage capacity of the femur's cuticular springs. The disproportionately greater jump energy and jump distance of adults is associated with relatively longer (12%) legs and a relatively larger (11%) femur muscle cross-sectional area, which could allow more strain loading into the femur's cuticular springs. Augmented jump performance in volant adult locusts achieves the take-off velocity required to initiate flight.

  14. Motion detectors in the locust visual system: From biology to robot sensors.

    PubMed

    Rind, F Claire

    2002-02-15

    Motion detectors in the locust optic lobe and brain fall into two categories: neurones that respond selectively to approaching vs. receding objects and neurones that respond selectively to a particular pattern of image motion over a substantial part of the eye, generated by the locust's own movements through its environment. Neurones from the two categories can be differentiated on the basis of their response to motion at a constant velocity at a fixed distance from the locust: neurones of the first category respond equally well to motion in any direction whereas neurones in the second category respond selectively to one preferred direction of motion. Several of the motion detectors of the first category, responding to approaching objects, share the same input organisation, suggesting that it is important in generating a tuning for approaching objects. Anatomical, physiological, and modelling studies have revealed how the selectivity of the response is generated. The selectivity arises as a result of a critical race between excitation, generated when image edges move out over the eye and delayed inhibition, generated by the same edge movements. For excitation to build up, the velocity and extent of edge motion over the eye must increase rapidly. The ultrastructure of the afferent inputs onto the dendrites of collision sensitive neurones reveals a possible substrate for the interaction between excitation and inhibition. This interpretation is supported by both physiological and immunocytochemical evidence. The input organisation of these neurones has been incorporated into the control structure of a small mobile robot, which successfully avoids collisions with looming objects. The ecological role of motion detectors of the second category that respond to image motion over a substantial part of the visual field, is discussed as is the input organisation that generates this selective response. The broad tuning of these neurones, particularly at low velocities (<0

  15. Unusual Giant Prostatic Urethral Calculus

    PubMed Central

    Bello, A.; Maitama, H. Y.; Mbibu, N. H.; Kalayi, G. D.; Ahmed, A.

    2010-01-01

    Giant vesico-prostatic urethral calculus is uncommon. Urethral stones rarely form primarily in the urethra, and they are usually associated with urethral strictures, posterior urethral valve or diverticula. We report a case of a 32-year-old man with giant vesico-prostatic (collar-stud) urethral stone presenting with sepsis and bladder outlet obstruction. The clinical presentation, management, and outcome of the giant prostatic urethral calculus are reviewed. PMID:22091328

  16. Giant bulla mimicking tension pneumothorax.

    PubMed

    Gökçe, Mertol; Saydam, Ozkan; Altin, Remzi; Kart, Levent

    2009-01-01

    In the chest X-ray, we observe tension pneumothorax (TPX) as wide radiolucent view in a hemithorax and pushing the mediastinal structures contralateral. Giant bulla may mimic TPX with wide radiolucent view and mediastinal shift. The present report includes giant pulmonary bulla in 35-year-old woman. The giant bulla was diagnosed as a TPX in emergency, and chest tube was performed. The differentiation between TPX and a giant bulla may be very difficult. The therapies of these two similar entities are completely different. So that, we must be careful about anamnesis, physical examination and radiology for true diagnosis.

  17. The cytogenetic effects of the aqueous extracts of migratory locust (Locusta migratoria L.) in vitro.

    PubMed

    Turkez, Hasan; Incekara, Umit; Güner, Adem; Aydın, Elanur; Dirican, Ebubekir; Togar, Başak

    2014-04-01

    One of the useful and most commonly cultivated commercially species, migratory locust (Locusta migratoria; Orthoptera), was investigated in light of genotoxic damage potentials. For this aim, we evaluated the genotoxic potentials of water soluble extracts of L. migratoria on cultured human blood cells. The micronucleus, sister chromatid exchange and structural chromosome aberration assays were applied to assess DNA and chromosomal damage produced by aqueous extracts in vitro. The extracts were added to the cultures at different concentrations ranging from 0 to 1000 mg/L. Our results indicated that these extracts did not exhibit genotoxicity at tested concentrations. We conclude that this in vitro approach for biomonitoring genotoxicity assessment is useful for comparing the potential health risks of edible insects.

  18. Hebbian STDP in mushroom bodies facilitates the synchronous flow of olfactory information in locusts.

    PubMed

    Cassenaer, Stijn; Laurent, Gilles

    2007-08-09

    Odour representations in insects undergo progressive transformations and decorrelation from the receptor array to the presumed site of odour learning, the mushroom body. There, odours are represented by sparse assemblies of Kenyon cells in a large population. Using intracellular recordings in vivo, we examined transmission and plasticity at the synapse made by Kenyon cells onto downstream targets in locusts. We find that these individual synapses are excitatory and undergo hebbian spike-timing dependent plasticity (STDP) on a +/-25 ms timescale. When placed in the context of odour-evoked Kenyon cell activity (a 20-Hz oscillatory population discharge), this form of STDP enhances the synchronization of the Kenyon cells' targets and thus helps preserve the propagation of the odour-specific codes through the olfactory system.

  19. Influence of hydroponic culture method on morphology and hydraulic conductivity of roots of honey locust.

    PubMed

    Graves, W R

    1992-09-01

    The morphology and hydraulic conductivity of root systems of Gleditsia triacanthos L. var. inermis Willd. (honey locust) grown hydroponically in sand and solution cultures were compared. Total root system length was similar in the two cultures. However, root systems grown in solution had longer primary roots, fewer lateral roots and root hairs, and a greater distance between the tip of the primary root and the junction of the youngest secondary root and the primary root than root systems grown in sand. Hydraulic conductivities of root systems grown hydroponically for 21 or 35 days in sand or solution culture were similar. These findings show that different methods of hydroponic culture can affect root morphology without altering root resistance to water transport.

  20. The complex aerodynamic footprint of desert locusts revealed by large-volume tomographic particle image velocimetry

    PubMed Central

    Henningsson, Per; Michaelis, Dirk; Nakata, Toshiyuki; Schanz, Daniel; Geisler, Reinhard; Schröder, Andreas; Bomphrey, Richard J.

    2015-01-01

    Particle image velocimetry has been the preferred experimental technique with which to study the aerodynamics of animal flight for over a decade. In that time, hardware has become more accessible and the software has progressed from the acquisition of planes through the flow field to the reconstruction of small volumetric measurements. Until now, it has not been possible to capture large volumes that incorporate the full wavelength of the aerodynamic track left behind during a complete wingbeat cycle. Here, we use a unique apparatus to acquire the first instantaneous wake volume of a flying animal's entire wingbeat. We confirm the presence of wake deformation behind desert locusts and quantify the effect of that deformation on estimates of aerodynamic force and the efficiency of lift generation. We present previously undescribed vortex wake phenomena, including entrainment around the wing-tip vortices of a set of secondary vortices borne of Kelvin–Helmholtz instability in the shear layer behind the flapping wings. PMID:26040598

  1. κ-Carrageenan/locust bean gum as hard capsule gelling agents.

    PubMed

    He, Huanghuang; Ye, Jing; Zhang, Xueqin; Huang, Yayan; Li, Xiaohui; Xiao, Meitian

    2017-11-01

    A novel gelling agent, comprising blended κ-carrageenan (κ-C), a seaweed polysaccharide and locust bean gum (LBG), was used to prepare hard capsules. The distinct synergism between κ-C and LBG were verified by the textural profile analysis (TPA), FTIR and rheological measurement. Afterwards, films and hard capsules were prepared with the optimized LBG/κ-C blend gel. And the mechanical properties and morphology of films and hard capsules were analyzed by tensile testing and SEM, respectively. The results showed that the LBG/κ-C at 1:3 ratio could serve as an excellent gelling agent, which endowed hard capsule with the promoted mechanical properties, homogenous and smooth surface morphology. This work suggests that a novel blended LBG/κ-C gelling agent successfully prepared for hard capsules with improving physicochemical properties. Copyright © 2017. Published by Elsevier Ltd.

  2. Slow motor neuron stimulation of locust skeletal muscle: model and measurement.

    PubMed

    Wilson, Emma; Rustighi, Emiliano; Newland, Philip L; Mace, Brian R

    2013-06-01

    The isometric force response of the locust hind leg extensor tibia muscle to stimulation of a slow extensor tibia motor neuron is experimentally investigated, and a mathematical model describing the response presented. The measured force response was modelled by considering the ability of an existing model, developed to describe the response to the stimulation of a fast extensor tibia motor neuron and to also model the response to slow motor neuron stimulation. It is found that despite large differences in the force response to slow and fast motor neuron stimulation, which could be accounted for by the differing physiology of the fibres they innervate, the model is able to describe the response to both fast and slow motor neuron stimulation. Thus, the presented model provides a potentially generally applicable, robust, simple model to describe the isometric force response of a range of muscles.

  3. The complex aerodynamic footprint of desert locusts revealed by large-volume tomographic particle image velocimetry.

    PubMed

    Henningsson, Per; Michaelis, Dirk; Nakata, Toshiyuki; Schanz, Daniel; Geisler, Reinhard; Schröder, Andreas; Bomphrey, Richard J

    2015-07-06

    Particle image velocimetry has been the preferred experimental technique with which to study the aerodynamics of animal flight for over a decade. In that time, hardware has become more accessible and the software has progressed from the acquisition of planes through the flow field to the reconstruction of small volumetric measurements. Until now, it has not been possible to capture large volumes that incorporate the full wavelength of the aerodynamic track left behind during a complete wingbeat cycle. Here, we use a unique apparatus to acquire the first instantaneous wake volume of a flying animal's entire wingbeat. We confirm the presence of wake deformation behind desert locusts and quantify the effect of that deformation on estimates of aerodynamic force and the efficiency of lift generation. We present previously undescribed vortex wake phenomena, including entrainment around the wing-tip vortices of a set of secondary vortices borne of Kelvin-Helmholtz instability in the shear layer behind the flapping wings.

  4. Evolution and environmental degradation of superhydrophobic aspen and black locust leaf surfaces

    NASA Astrophysics Data System (ADS)

    Tranquada, George Christopher

    The current study is focused on the characterization of four natural leaf species (quaking, bigtooth and columnar european aspen as well as black locust) possessing a unique dual-scale cuticle structure composed of micro- and nano-scale asperities, which are able to effectively resist wetting (superhydrophobic), characteristic of The Lotus Effect. Scanning Electron Microscopy (SEM) was used to track the growth and evolution of their distinctive nano-scale epicuticular wax (ECW) morphologies over one full growing season. In addition, the stability of their superhydrophobic property was tested in various environments. It was determined that the long-term stability of these surfaces is tentatively linked to various environmental stress factors. Specifically, a combination of high temperature and humidity caused the degradation of nanoscale asperities and loss of the superhydrophobic property. The dual-scale surface structure was found to provide a suitable template for the design of future superhydrophobic engineering materials.

  5. Developmental and activity-dependent plasticity of filiform hair receptors in the locust

    PubMed Central

    Pflüger, Hans-Joachim; Wolf, Harald

    2013-01-01

    A group of wind sensitive filiform hair receptors on the locust thorax and head makes contact onto a pair of identified interneuron, A4I1. The hair receptors' central nervous projections exhibit pronounced structural dynamics during nymphal development, for example, by gradually eliminating their ipsilateral dendritic field while maintaining the contralateral one. These changes are dependent not only on hormones controlling development but on neuronal activity as well. The hair-to-interneuron system has remarkably high gain (close to 1) and makes contact to flight steering muscles. During stationary flight in front of a wind tunnel, interneuron A4I1 is active in the wing beat rhythm, and in addition it responds strongly to stimulation of sensory hairs in its receptive field. A role of the hair-to-interneuron in flight steering is thus suggested. This system appears suitable for further study of developmental and activity-dependent plasticity in a sensorimotor context with known connectivity patterns. PMID:23986712

  6. Sardine cycles, krill declines, and locust plagues: revisiting 'wasp-waist' food webs.

    PubMed

    Atkinson, Angus; Hill, Simeon L; Barange, Manuel; Pakhomov, Evgeny A; Raubenheimer, David; Schmidt, Katrin; Simpson, Stephen J; Reiss, Christian

    2014-06-01

    'Wasp-waist' systems are dominated by a mid trophic-level species that is thought to exert top-down control on its food and bottom-up control on its predators. Sardines, anchovy, and Antarctic krill are suggested examples, and here we use locusts to explore whether the wasp-waist concept also applies on land. These examples also display the traits of mobile aggregations and dietary diversity, which help to reduce the foraging footprint from their large, localised biomasses. This suggests that top-down control on their food operates at local aggregation scales and not at wider scales suggested by the original definition of wasp-waist. With this modification, the wasp-waist framework can cross-fertilise marine and terrestrial approaches, revealing how seemingly disparate but economically important systems operate.

  7. Effect of carboxymethylation on rheological and drug release characteristics of locust bean gum matrix tablets.

    PubMed

    Chakravorty, Amrita; Barman, Gouranga; Mukherjee, Sudipta; Sa, Biswanath

    2016-06-25

    This study was undertaken to investigate correlation between the carboxymethylation-induced rheological changes and drug release characteristics of locust bean gum (LBG) matrix tablets. LBG was derivatized to carboxymethyl LBG (CMLBG) and characterized by (13)C NMR, FTIR and elemental analyses. Rheological studies revealed that LBG, in contact with water, produced a strong elastic gel which swelled less due to lower penetration of water resulting in slower drug release. On the other hand, CMLBG formed a viscous polymer solution through which higher influx of water resulted in rapid swelling of the matrix and faster drug release. Although the release from a particular matrix was dependent on drugs' solubilities, CMLBG matrix tablet produced faster release of all the drugs than LBG matrix tablets. In conclusion, rheological study appeared to be an useful tool to predict release of drugs from polysaccharide matrix tablets.

  8. Interpenetrating polymer network of locust bean gum-poly (vinyl alcohol) for controlled release drug delivery.

    PubMed

    Kaity, Santanu; Isaac, Jinu; Ghosh, Animesh

    2013-04-15

    A novel interpenetrating polymer network (IPN) microspheres of locust bean gum (LBG) and poly (vinyl alcohol) (PVA) was developed for oral controlled release of buflomedil hydrochloride (BH) by emulsion crosslinking method using glutaraldehyde as crosslinker. The effects of gum-polymer ratio, concentration of crosslinker and internal phase viscosity were evaluated thoroughly. Drug entrapment efficiency, particle size distribution, swelling property and in vitro release characteristics with kinetic modelling of microspheres were evaluated. The microspheres were characterised by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), solid state C(13) NMR, X-ray diffraction study (XRD) and differential scanning colorimetry (DSC). The microspheres showed control release property without showing any incompatibility in IPN device. Hence, IPN microspheres of LBG and PVA can be used as a potential carrier for controlled oral delivery of highly water soluble drugs like BH.

  9. Preparation and characterization of tragacanth-locust bean gum edible blend films.

    PubMed

    Mostafavi, Fatemeh Sadat; Kadkhodaee, Rassoul; Emadzadeh, Bahareh; Koocheki, Arash

    2016-03-30

    The present work introduces the structure and physicomechanical properties of a novel blend film made from binary solutions of gum tragacanth (GT) and locust bean gum (LBG) at different mixing ratios. Apparent viscosities and surface tensions of individual and blend gum solutions were also investigated. The viscosity data indicated that there was a distinct synergism between the two gums at all mixing ratios. FTIR spectra showed the existence of noncovalent intermolecular interactions between gums. The surface tensions of binary solutions were significantly lower than those of individual gums which is advantageous for coating applications. All films had homogenous and smooth surface morphology and their transparency, water vapour barrier and mechanical properties were improved by incorporating LBG in blend. The results of this study suggest that GT-LBG blend film, owing to its desirable properties, has the potential to be used as a new degradable food packaging material.

  10. A bird's-eye view on the modern genetics workflow and its potential applicability to the locust problem.

    PubMed

    Bakkali, Mohammed

    2013-08-01

    Genetics is an immense science and the current developments in its methods and techniques as well as the fast emerging tools make it one of the most powerful biological sciences. Indeed, from taxonomy and ecology to physiology and molecular biology, every biological science makes use of genetics techniques and methods at one time or another. In fact, development in genetics is such that it is now possible to characterize and analyze the expression of the whole set of genes of virtually every living organism, even if it is a non-model one. Locusts are notorious for the damage they cause to the ecosystems and economies of the areas affected by their recurrent population outbreaks. To prevent and deal with these outbreaks, we now count on both biological as well as chemical agents that are proving to be successful in reducing the damage that otherwise locust population outbreaks might cause. However, a better, efficient and environmentally friendly solution is still a hoped-for target. In my opinion, the ideal future pesticide should be both environmentally friendly, risk free and species-specific. To reach the knowledge needed for the development of such species-specific anti-locust agent, deep and accurate knowledge of the locusts' genetics and molecular biology is a must. Since genes and their expression levels lie at the bottom of every biological phenomenon, any species-specific solution to the locust problem requires a good knowledge of these organisms' genes as well as the quantitative and spatio-temporal dynamics of their expression. To reach such knowledge, collaborative work is needed as well as a clear workflow that, given the fast development in the genetics tools, is not always clear to all research groups. For this reason, here I describe a genetics workflow that should allow taking advantage of the most recent genetics tools and techniques to answer question relating to locust biology. My hope is that the adoption of this and other work strategies by

  11. Sulfakinin is an important regulator of digestive processes in the migratory locust, Locusta migratoria.

    PubMed

    Zels, Sven; Dillen, Senne; Crabbé, Katleen; Spit, Jornt; Nachman, Ronald J; Vanden Broeck, Jozef

    2015-06-01

    Sulfakinin (SK) is a sulfated insect neuropeptide that is best known for its function as a satiety factor. It displays structural and functional similarities with the vertebrate peptides gastrin and cholecystokinin. Peptidomic studies in multiple insects, crustaceans and arachnids have revealed the widespread occurrence of SK in the arthropod phylum. Multiple studies in hemi- and holometabolous insects revealed the pleiotropic nature of this neuropeptide: in addition to its activity as a satiety factor, SK was also reported to affect muscle contraction, digestive enzyme release, odor preference, aggression and metabolism. However, the main site of action seems to be the digestive system of insects. In this study, we have investigated whether SK can intervene in the control of nutrient uptake and digestion in the migratory locust (Locusta migratoria). We provide evidence that sulfakinin reduces food uptake in this species. Furthermore, we discovered that SK has very pronounced effects on the main digestive enzyme secreting parts of the locust gut. It effectively reduced digestive enzyme secretion from both the midgut and gastric caeca. SK injection also elicited a reduction in absorbance and proteolytic activity of the gastric caeca contents. The characteristic sulfation of the tyrosine residue is crucial for the observed effects on digestive enzyme secretion. In an attempt to provide potential leads for the development of peptidomimetic compounds based on SK, we also tested two mimetic analogs of the natural peptide ligand in the digestive enzyme secretion assay. These analogs were able to mimic the effect of the natural SK, but their effects were milder. The results of this study provide new insights into the action of SK on the digestive system in (hemimetabolous) insects.

  12. Identification of female-produced sex pheromone of the honey locust gall midge, Dasineura gleditchiae.

    PubMed

    Molnár, Béla; Kárpáti, Zsolt; Szocs, Gábor; Hall, David R

    2009-06-01

    The honey locust gall midge, Dasineura gleditchiae Osten Sacken 1866 (Diptera: Cecidomyiidae) is the main pest of ornamental varieties of the honey locust tree, Gleditsia triacanthos L., in North America, and is now becoming a pest of concern in Europe. Female midges were observed to emerge in the early morning with their ovipositor extended until they mated. Volatiles were collected from virgin females in a closed-loop stripping apparatus and analyzed by gas chromatography (GC) coupled to electroantennographic (EAG) recording from the antenna of a male midge. A single EAG response was observed, which was assumed to be to the major component of the female sex pheromone. This was identified as (Z)-2-acetoxy-8-heptadecene by comparison of its mass spectrum and GC retention times on different columns with those of synthetic standards and by micro-analytical reactions. This compound was synthesized, and the individual enantiomers were produced by kinetic resolution with lipase from Candida antarctica. Analysis of the naturally-produced compound on a cyclodextrin GC column indicated it was the (R)-enantiomer. In EAG dose-response measurements, the (R)-enantiomer alone or in the racemic mixture evoked significant responses from the antennae of male D. gleditchiae, whereas the (S)-enantiomer did not. In field trapping tests, the (R)-enantiomer attracted male D. gleditchiae. The racemic compound was equally attractive, but the (S)-enantiomer was not attractive. Both the pure (R)-enantiomer or racemic (Z)-2-acetoxy-8-heptadecene, applied to red rubber septa in a dose range of 3-30 microg, constitute a strongly attractive bait in sticky traps for monitoring the flight of D. gleditchiae.

  13. Pharmacological blockade of gap junctions induces repetitive surging of extracellular potassium within the locust CNS.

    PubMed

    Spong, Kristin E; Robertson, R Meldrum

    2013-10-01

    The maintenance of cellular ion homeostasis is crucial for optimal neural function and thus it is of great importance to understand its regulation. Glial cells are extensively coupled by gap junctions forming a network that is suggested to serve as a spatial buffer for potassium (K(+)) ions. We have investigated the role of glial spatial buffering in the regulation of extracellular K(+) concentration ([K(+)]o) within the locust metathoracic ganglion by pharmacologically inhibiting gap junctions. Using K(+)-sensitive microelectrodes, we measured [K(+)]o near the ventilatory neuropile while simultaneously recording the ventilatory rhythm as a model of neural circuit function. We found that blockade of gap junctions with either carbenoxolone (CBX), 18β-glycyrrhetinic acid (18β-GA) or meclofenamic acid (MFA) reliably induced repetitive [K(+)]o surges and caused a progressive impairment in the ability to maintain baseline [K(+)]o levels throughout the treatment period. We also show that a low dose of CBX that did not induce surging activity increased the vulnerability of locust neural tissue to spreading depression (SD) induced by Na(+)/K(+)-ATPase inhibition with ouabain. CBX pre-treatment increased the number of SD events induced by ouabain and hindered the recovery of [K(+)]o back to baseline levels between events. Our results suggest that glial spatial buffering through gap junctions plays an essential role in the regulation of [K(+)]o under normal conditions and also contributes to a component of [K(+)]o clearance following physiologically elevated levels of [K(+)]o. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Identification and distribution of SIFamide in the nervous system of the desert locust Schistocerca gregaria.

    PubMed

    Gellerer, Alina; Franke, Aileen; Neupert, Susanne; Predel, Reinhard; Zhou, Xin; Liu, Shanlin; Reiher, Wencke; Wegener, Christian; Homberg, Uwe

    2015-01-01

    SIFamides are a family of highly conserved arthropod neuropeptides. To date, nine orthocopies from different arthropods, most of them insects, have been identified, all consisting of 11-12 amino acid residues. The striking conservation in sequence is mirrored by highly similar morphologies of SIFamide-immunoreactive neurons: immunolabeling in various insect species revealed four immunopositive neurons with somata in the pars intercerebralis and arborizations extending throughout the brain and ventral nervous system. In contrast, the functional role of these neurons and their neuropeptide SIFamide is largely obscure. To provide an additional basis for functional analysis, we identified, by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry, a SIFamide peptide in the desert locust Schistocerca gregaria and studied its distribution throughout the nervous system. Identification was supported by analysis of transcriptomic data obtained from another grasshopper, Stenobothrus lineatus. Scg-SIFamide, unlike all SIFamides identified so far, is a pentadecapeptide with an extended and highly modified N-terminus (AAATFRRPPFNGSIFamide). As in other insects, pairs of descending neurons with somata in the pars intercerebralis and ramifications in most areas of the nervous system are SIFamide-immunoreactive. In addition, a small number of local interneurons in the brain and ventral ganglia were immunostained. Double-label experiments showed that the SIFamide-immunoreactive descending neurons are identical to previously characterized primary commissure pioneer (PNP) neurons of the locust brain that pioneer the first commissure in the brain. The data suggest that the descending SIFamide-immunoreactive neurons play a developmental role in organizing the insect central nervous system. J. Comp. Neurol. 523:108-125, 2015. © 2014 Wiley Periodicals, Inc.

  15. Amplitude and dynamics of polarization-plane signaling in the central complex of the locust brain

    PubMed Central

    Bockhorst, Tobias

    2015-01-01

    The polarization pattern of skylight provides a compass cue that various insect species use for allocentric orientation. In the desert locust, Schistocerca gregaria, a network of neurons tuned to the electric field vector (E-vector) angle of polarized light is present in the central complex of the brain. Preferred E-vector angles vary along slices of neuropils in a compasslike fashion (polarotopy). We studied how the activity in this polarotopic population is modulated in ways suited to control compass-guided locomotion. To this end, we analyzed tuning profiles using measures of correlation between spike rate and E-vector angle and, furthermore, tested for adaptation to stationary angles. The results suggest that the polarotopy is stabilized by antagonistic integration across neurons with opponent tuning. Downstream to the input stage of the network, responses to stationary E-vector angles adapted quickly, which may correlate with a tendency to steer a steady course previously observed in tethered flying locusts. By contrast, rotating E-vectors corresponding to changes in heading direction under a natural sky elicited nonadapting responses. However, response amplitudes were particularly variable at the output stage, covarying with the level of ongoing activity. Moreover, the responses to rotating E-vector angles depended on the direction of rotation in an anticipatory manner. Our observations support a view of the central complex as a substrate of higher-stage processing that could assign contextual meaning to sensory input for motor control in goal-driven behaviors. Parallels to higher-stage processing of sensory information in vertebrates are discussed. PMID:25609107

  16. Amplitude and dynamics of polarization-plane signaling in the central complex of the locust brain.

    PubMed

    Bockhorst, Tobias; Homberg, Uwe

    2015-05-01

    The polarization pattern of skylight provides a compass cue that various insect species use for allocentric orientation. In the desert locust, Schistocerca gregaria, a network of neurons tuned to the electric field vector (E-vector) angle of polarized light is present in the central complex of the brain. Preferred E-vector angles vary along slices of neuropils in a compasslike fashion (polarotopy). We studied how the activity in this polarotopic population is modulated in ways suited to control compass-guided locomotion. To this end, we analyzed tuning profiles using measures of correlation between spike rate and E-vector angle and, furthermore, tested for adaptation to stationary angles. The results suggest that the polarotopy is stabilized by antagonistic integration across neurons with opponent tuning. Downstream to the input stage of the network, responses to stationary E-vector angles adapted quickly, which may correlate with a tendency to steer a steady course previously observed in tethered flying locusts. By contrast, rotating E-vectors corresponding to changes in heading direction under a natural sky elicited nonadapting responses. However, response amplitudes were particularly variable at the output stage, covarying with the level of ongoing activity. Moreover, the responses to rotating E-vector angles depended on the direction of rotation in an anticipatory manner. Our observations support a view of the central complex as a substrate of higher-stage processing that could assign contextual meaning to sensory input for motor control in goal-driven behaviors. Parallels to higher-stage processing of sensory information in vertebrates are discussed. Copyright © 2015 the American Physiological Society.

  17. Interaction of compass sensing and object-motion detection in the locust central complex.

    PubMed

    Bockhorst, Tobias; Homberg, Uwe

    2017-07-01

    Goal-directed behavior is often complicated by unpredictable events, such as the appearance of a predator during directed locomotion. This situation requires adaptive responses like evasive maneuvers followed by subsequent reorientation and course correction. Here we study the possible neural underpinnings of such a situation in an insect, the desert locust. As in other insects, its sense of spatial orientation strongly relies on the central complex, a group of midline brain neuropils. The central complex houses sky compass cells that signal the polarization plane of skylight and thus indicate the animal's steering direction relative to the sun. Most of these cells additionally respond to small moving objects that drive fast sensory-motor circuits for escape. Here we investigate how the presentation of a moving object influences activity of the neurons during compass signaling. Cells responded in one of two ways: in some neurons, responses to the moving object were simply added to the compass response that had adapted during continuous stimulation by stationary polarized light. By contrast, other neurons disadapted, i.e., regained their full compass response to polarized light, when a moving object was presented. We propose that the latter case could help to prepare for reorientation of the animal after escape. A neuronal network based on central-complex architecture can explain both responses by slight changes in the dynamics and amplitudes of adaptation to polarized light in CL columnar input neurons of the system.NEW & NOTEWORTHY Neurons of the central complex in several insects signal compass directions through sensitivity to the sky polarization pattern. In locusts, these neurons also respond to moving objects. We show here that during polarized-light presentation, responses to moving objects override their compass signaling or restore adapted inhibitory as well as excitatory compass responses. A network model is presented to explain the variations of these

  18. Characterization and functional analysis of four glutathione S-transferases from the migratory locust, Locusta migratoria.

    PubMed

    Qin, Guohua; Jia, Miao; Liu, Ting; Zhang, Xueyao; Guo, Yaping; Zhu, Kun Yan; Ma, Enbo; Zhang, Jianzhen

    2013-01-01

    Glutathione S-transferases (GSTs) play an important role in detoxification of xenobiotics in both prokaryotic and eukaryotic cells. In this study, four GSTs (LmGSTd1, LmGSTs5, LmGSTt1, and LmGSTu1) representing different classes were identified from the migratory locust, Locusta migratoria. These four proteins were heterologously expressed in Escherichia coli as soluble fusion proteins, purified by Ni(2+)-nitrilotriacetic acid agarose column and biochemically characterized. LmGSTd1, LmGSTs5, and LmGSTu1 showed high activities with 1-chloro-2, 4-dinitrobenzene (CDNB), detectable activity with p-nitro-benzyl chloride (p-NBC) and 1, 2-dichloro-4-nitrobenzene (DCNB), whereas LmGSTt1 showed high activity with p-NBC and detectable activity with CDNB. The optimal pH of the locust GSTs ranged between 7.0 to 9.0. Ethacrynic acid and reactive blue effectively inhibited all four GSTs. LmGSTs5 was most sensitive to heavy metals (Cu(2+) and Cd(2+)). The maximum expression of the four GSTs was observed in Malpighian tubules and fat bodies as evaluated by western blot. The nymph mortalities after carbaryl treatment increased by 28 and 12% after LmGSTs5 and LmGSTu1 were silenced, respectively. The nymph mortalities after malathion and chlorpyrifos treatments increased by 26 and 18% after LmGSTs5 and LmGSTu1 were silenced, respectively. These results suggest that sigma GSTs in L. migratoria play a significant role in carbaryl detoxification, whereas some of other GSTs may also involve in the detoxification of carbaryl and chlorpyrifos.

  19. Formation of cereulide and enterotoxins by Bacillus cereus in fermented African locust beans.

    PubMed

    Thorsen, Line; Azokpota, Paulin; Munk Hansen, Bjarne; Rønsbo, Mie Hvillum; Nielsen, Kristian Fog; Hounhouigan, D Joseph; Jakobsen, Mogens

    2011-12-01

    Afitin, iru and sonru are three spontaneously fermented African locust bean Benin condiments. The fermentation processes are exothermic, with temperatures mostly being above 40 °C. A total of 19 predominant Bacillus cereus isolates from afitin, iru and sonru, were investigated. The enterotoxin genes nhe (A, B, C) were present in all 19 isolates, the hbl (A, C, D) in one (afitin), and the cytK gene in three isolates (afitin). Levels of cytotoxicity to Vero cells and NheA production in BHI-broth was within the range of known diarrheal outbreak strains. Autoclaved cooked African locust beans inoculated with emetic (cereulide producing) B. cereus Ba18H2/RIF supported growth at 25, 30 and 40 °C with highly different maximum cereulide productions of 6 ± 5, 97 ± 3 and 0.04 ± 0.02 μg/g beans, respectively (48 h). For non-autoclaved cooked beans inoculated with 2, 4 and 6 log(10)B. cereus Ba18H2/RIF spores/g beans, cereulide production was 5 ± 4, 64 ± 8 and 69 ± 34 μg/g beans, respectively at 24 h, while it was 70 ± 43, 92 ± 53 and 99 ± 31 μg/g at 48 h of fermentation at 30 °C. Even though high toxin levels were observed, to date there are no known reports on diarrhea or vomiting due to the consumption or afitin, iru and sonru in Benin, which also according to the present study is likely to be expected from the low levels of cereulide produced at 40 °C.

  20. Imaging Extrasolar Giant Planets

    NASA Astrophysics Data System (ADS)

    Bowler, Brendan P.

    2016-10-01

    High-contrast adaptive optics (AO) imaging is a powerful technique to probe the architectures of planetary systems from the outside-in and survey the atmospheres of self-luminous giant planets. Direct imaging has rapidly matured over the past decade and especially the last few years with the advent of high-order AO systems, dedicated planet-finding instruments with specialized coronagraphs, and innovative observing and post-processing strategies to suppress speckle noise. This review summarizes recent progress in high-contrast imaging with particular emphasis on observational results, discoveries near and below the deuterium-burning limit, and a practical overview of large-scale surveys and dedicated instruments. I conclude with a statistical meta-analysis of deep imaging surveys in the literature. Based on observations of 384 unique and single young (≈5-300 Myr) stars spanning stellar masses between 0.1 and 3.0 M ⊙, the overall occurrence rate of 5-13 M Jup companions at orbital distances of 30-300 au is {0.6}-0.5+0.7 % assuming hot-start evolutionary models. The most massive giant planets regularly accessible to direct imaging are about as rare as hot Jupiters are around Sun-like stars. Dividing this sample into individual stellar mass bins does not reveal any statistically significant trend in planet frequency with host mass: giant planets are found around {2.8}-2.3+3.7 % of BA stars, <4.1% of FGK stars, and <3.9% of M dwarfs. Looking forward, extreme AO systems and the next generation of ground- and space-based telescopes with smaller inner working angles and deeper detection limits will increase the pace of discovery to ultimately map the demographics, composition, evolution, and origin of planets spanning a broad range of masses and ages.

  1. Giant left ventricular pseudoaneurysm.

    PubMed

    Prakash, Sumi; Garg, Nadish; Xie, Gong-Yuan; Dellsperger, Kevin C

    2010-01-01

    Left ventricular (LV) pseudoaneurysm (PS) is an uncommon, often fatal complication associated with myocardial infarction, cardiothoracic surgery, trauma, and, rarely, infective endocarditis. A 28-year-old man with prior history of bioprosthetic mitral valve replacement presented with congestive heart failure and bacteremia with Abiotrophia granulitica. Transesophageal echocardiogram showed bioprosthesis dysfunction, large vegetations, mitral regurgitation, and probable PS. Cardiac and chest CT confirmed a PS communicating with the left ventricle Patient had pulseless electrical activity and died. Autopsy showed a giant PS with layered thrombus and pseudo-endothelialized cavity. Our case highlights the importance of multimodality imaging as an important tool in management of PS.

  2. Giant mesenteric cyst

    PubMed Central

    Guraya, Salman Yousuf; Salman, Shaista; Almaramhy, Hamdi H.

    2011-01-01

    Mesenteric cysts are uncommon benign abdominal lesions with no classical clinical features. The preoperative diagnosis requires the common imaging modalities but the final diagnosis is established only during surgery or histological analysis. The treatment of choice is complete surgical excision. We report an 18-year-old female with a non-specific abdominal pain and discomfort since 3 weeks. Her CT scan showed a huge cystic swelling, which necessitated surgical exploration. Preoperatively, a giant cyst was encountered with displacement of bowel loops. The cyst was completely removed and histology report confirmed mesenteric cyst without evidence of malignancy. PMID:24765349

  3. Giant mesenteric cyst.

    PubMed

    Guraya, Salman Yousuf; Salman, Shaista; Almaramhy, Hamdi H

    2011-09-28

    Mesenteric cysts are uncommon benign abdominal lesions with no classical clinical features. The preoperative diagnosis requires the common imaging modalities but the final diagnosis is established only during surgery or histological analysis. The treatment of choice is complete surgical excision. We report an 18-year-old female with a non-specific abdominal pain and discomfort since 3 weeks. Her CT scan showed a huge cystic swelling, which necessitated surgical exploration. Preoperatively, a giant cyst was encountered with displacement of bowel loops. The cyst was completely removed and histology report confirmed mesenteric cyst without evidence of malignancy.

  4. A Giant Urethral Calculus.

    PubMed

    Sigdel, G; Agarwal, A; Keshaw, B W

    2014-01-01

    Urethral calculi are rare forms of urolithiasis. Majority of the calculi are migratory from urinary bladder or upper urinary tract. Primary urethral calculi usually occur in presence of urethral stricture or diverticulum. In this article we report a case of a giant posterior urethral calculus measuring 7x3x2 cm in a 47 years old male. Patient presented with acute retention of urine which was preceded by burning micturition and dribbling of urine for one week. The calculus was pushed in to the bladder through the cystoscope and was removed by suprapubic cystolithotomy.

  5. Giant extragenital Bowen's disease.

    PubMed

    Bakardzhiev, Ilko; Chokoeva, Anastasiya Atanasova; Tchernev, Georgi

    2015-12-01

    Giant extragenital forms of Morbus Bowen are extremely rare. The already described cases in the word literature are most commonly with periungual localization, as well as located on the foot and neck area. The clinical manifestation is presented most commonly by non-specific erythematous to erythematous-squamous plaques or papules, which is confusing to the clinician. From the pathogenic point of view, it is important to be confirmed or rejected the presence of human papilloma viruses (HPVs) in each case of affected patient, as this information is mandatory in respect to the adequate selection of the subsequent regimen. If HPVs are detected, systemic antiviral therapy could be initiated to reduce the size of the lesions before subsequent surgical eradication. A postoperative prevention through vaccination could be also considered additionally. In cases of HPV-negative giant extragenital forms of Morbus Bowen (as in the described patient), the focus should be on local immunomodulation by substances such as imiquimod, which reduce the size of the lesions, thereby creating optimal opportunities for their future surgical eradication. Other possible options described in the literature include topical application of 5-fluorouracil, photodynamic therapy, cryotherapy, and laser therapy (carbon dioxide laser). The choice of the most appropriate regimen should have been an individual decision of the clinician, considering also the location and the extent of the lesion.

  6. Gas Giants Form Quickly

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This is an artist's concept of a hypothetical 10-million-year-old star system. The bright blur at the center is a star much like our sun. The other orb in the image is a gas-giant planet like Jupiter. Wisps of white throughout the image represent traces of gas.

    Astronomers using NASA's Spitzer Space Telescope have found evidence showing that gas-giant planets either form within the first 10 million years of a sun-like star's life, or not at all. The lifespan for sun-like stars is about 10 billion years.

    The scientists came to this conclusion after searching for traces of gas around 15 different sun-like stars, most with ages ranging from 3 million to 30 million years. With the help of Spitzer's Infrared Spectrometer instrument, they were able to search for relatively warm gas in the inner regions of these star systems, an area comparable to the zone between Earth and Jupiter in our own solar system. They also used ground-based radio telescopes to search for cooler gas in the outer regions of these systems, an area comparable to the zone around Saturn and beyond.

  7. Giant papillary conjunctivitis.

    PubMed Central

    Donshik, P C

    1994-01-01

    Giant papillary conjunctivitis is a syndrome found frequently as a complication of contact lenses. Many variables can affect the onset and severity of the presenting signs and symptoms. Rigid gas permeable contact lenses appear to result in less severe signs and symptoms, with a longer time before the development of giant papillary conjunctivitis. Nonionic, low-water-content soft contact lenses tend to produce less severe signs and symptoms than ionic, low-water-content soft contact lenses. Enzymatic treatment appears to lessen the severity of signs and symptoms. The association of an allergy appears to play a role in the onset of the severity of the signs and symptoms but does not appear to affect the final ability of the individual to wear contact lenses. Using multiple treatment options, such as changing the polymer to a glyceryl methyl methacrylate or a rigid lens, or utilizing a soft lens on a frequent-replacement basis, can result in a success rate of over 90%. In individuals who still have a return of symptoms, the use of topical mast cell stabilizers or a nonsteroidal anti-inflammatory drug as an adjunctive therapy offers the added possibility of keeping these patients in contact lenses. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 11 A FIGURE 11 B FIGURE 11 C FIGURE 11 D PMID:7886881

  8. Gas Giants Form Quickly

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This is an artist's concept of a hypothetical 10-million-year-old star system. The bright blur at the center is a star much like our sun. The other orb in the image is a gas-giant planet like Jupiter. Wisps of white throughout the image represent traces of gas.

    Astronomers using NASA's Spitzer Space Telescope have found evidence showing that gas-giant planets either form within the first 10 million years of a sun-like star's life, or not at all. The lifespan for sun-like stars is about 10 billion years.

    The scientists came to this conclusion after searching for traces of gas around 15 different sun-like stars, most with ages ranging from 3 million to 30 million years. With the help of Spitzer's Infrared Spectrometer instrument, they were able to search for relatively warm gas in the inner regions of these star systems, an area comparable to the zone between Earth and Jupiter in our own solar system. They also used ground-based radio telescopes to search for cooler gas in the outer regions of these systems, an area comparable to the zone around Saturn and beyond.

  9. Giant Intradiverticular Bladder Tumor

    PubMed Central

    Noh, Mohamad Syafeeq Faeez Md; Aziz, Ahmad Fuad Abdul; Ghani, Khairul Asri Mohd; Siang, Christopher Lee Kheng; Yunus, Rosna; Yusof, Mubarak Mohd

    2017-01-01

    Patient: Male, 74 Final Diagnosis: Giant intradiverticular bladder tumor with metastasis Symptoms: Hematuria Medication:— Clinical Procedure: — Specialty: Urology Objective: Rare disease Background: Intradiverticular bladder tumors are rare. This renders diagnosis of an intradiverticular bladder tumor difficult. Imaging plays a vital role in achieving the diagnosis, and subsequently staging of the disease. Case Report: A 74-year-old male presented to our center with a few months history of constitutional symptoms. Upon further history, he reported hematuria two months prior to presentation, which stopped temporarily, only to recur a few days prior to coming to the hospital. The patient admitted to having lower urinary tract symptoms. However, there was no dysuria, no sandy urine, and no fever. Palpation of his abdomen revealed a vague mass at the suprapubic region, which was non tender. In view of his history and the clinical examination findings, an ultrasound of the abdomen and computed tomography (CT) was arranged. These investigations revealed a giant tumor that seemed to be arising from a bladder diverticulum, with a mass effect and hydronephrosis. He later underwent operative intervention. Conclusions: Intradiverticular bladder tumors may present a challenge to the treating physician in an atypical presentation; thus requiring a high index of suspicion and knowledge of tumor pathophysiology. As illustrated in our case, CT with its wide availability and multiplanar imaging capabilities offers a useful means for diagnosis, disease staging, operative planning, and follow-up. PMID:28246375

  10. Reinflating Giant Planets

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-01-01

    Two new, large gas-giant exoplanets have been discovered orbiting close to their host stars. A recent study examining these planets and others like them may help us to better understand what happens to close-in hot Jupiters as their host stars reach the end of their main-sequence lives.OversizedGiantsUnbinned transit light curves for HAT-P-65b. [Adapted from Hartman et al. 2016]The discovery of HAT-P-65b and HAT-P-66b, two new transiting hot Jupiters, is intriguing. These planets have periods of just under 3 days and masses of roughly 0.5 and 0.8 times that of Jupiter, but their sizes are whats really interesting: they have inflated radii of 1.89 and 1.59 times that of Jupiter.These two planets, discovered using the Hungarian-made Automated Telescope Network (HATNet) in Arizona and Hawaii, mark the latest in an ever-growing sample of gas-giant exoplanets with radii larger than expected based on theoretical planetary structure models.What causes this discrepancy? Did the planets just fail to contract to the expected size when they were initially formed, or were they reinflated later in their lifetimes? If the latter, how? These are questions that scientists are only now starting to be able to address using statistics of the sample of close-in, transiting planets.Unbinned transit light curves for HAT-P-66b. [Hartman et al. 2016]Exploring Other PlanetsLed by Joel Hartman (Princeton University), the team that discovered HAT-P-65b and HAT-P-66b has examined these planets observed parameters and those of dozens of other known close-in, transiting exoplanets discovered with a variety of transiting exoplanet missions: HAT, WASP, Kepler, TrES, and KELT. Hartman and collaborators used this sample to draw conclusions about what causes some of these planets to have such large radii.The team found that there is a statistically significant correlation between the radii of close-in giant planets and the fractional ages of their host stars (i.e., the stars age divided by its full

  11. A long-latency aversive learning mechanism enables locusts to avoid odours associated with the consequences of ingesting toxic food.

    PubMed

    Simões, Patrício M V; Ott, Swidbert R; Niven, Jeremy E

    2012-05-15

    Avoiding food that contains toxins is crucial for the survival of many animals, particularly herbivores, because many plants defend themselves with toxins. Some animals can learn to avoid food containing toxins not through its taste but by the toxins' effects following ingestion, though how they do so remains unclear. We studied how desert locusts (Schistocerca gregaria), which are generalist herbivores, form post-ingestive aversive memories and use them to make appropriate olfactory-based decisions in a Y-maze. Locusts form an aversion gradually to an odour paired with food containing the toxin nicotine hydrogen tartrate (NHT), suggesting the involvement of a long-latency associative mechanism. Pairing of odour and toxin-free food accompanied by NHT injections at different latencies showed that locusts could form an association between an odour and toxic malaise, which could be separated by up to 30 min. Tasting but not swallowing the food, or the temporal separation of odour and food, prevents the formation of these long-latency associations, showing that they are post-ingestive. A second associative mechanism not contingent upon feeding operates only when odour presentation is simultaneous with NHT injection. Post-ingestive memory formation is not disrupted by exposure to a novel odour alone but can be if the odour is accompanied by simultaneous NHT injection. Thus, the timing with which food, odour and toxin are encountered whilst foraging is likely to influence memory formation and subsequent foraging decisions. Therefore, locusts can form specific long-lasting aversive olfactory associations that they can use to avoid toxin-containing foods whilst foraging.

  12. The Effect of Heat Treatment on the chemical and color change of Black Locust (Robinia Pseudoacacia) wood flour

    Treesearch

    Yao Chen; Yongming Fan; Jianmin Gao; Nicole M. Stark

    2012-01-01

    The aim of this study was to investigate the effects of oxygen and moisture content (MC) on the chemical and color changes of black locust (Robinia pseudoacacia) wood during heat treatment. The wood flour was conditioned to different initial MCs and heated for 24 h at a constant temperature of 120°C in either oxygen or nitrogen atmosphere. The pH values and...

  13. Potential of the Desert Locust Schistocerca gregaria (Orthoptera: Acrididae) as an Unconventional Source of Dietary and Therapeutic Sterols

    PubMed Central

    Cheseto, Xavier; Kuate, Serge Philibert; Tchouassi, David P.; Ndung’u, Mary; Teal, Peter E. A.; Torto, Baldwyn

    2015-01-01

    Insects are increasingly being recognized not only as a source of food to feed the ever growing world population but also as potential sources of new products and therapeutic agents, among which are sterols. In this study, we sought to profile sterols and their derivatives present in the desert locust, Schistocerca gregaria, focusing on those with potential importance as dietary and therapeutic components for humans. Using coupled gas chromatography-mass spectrometry (GC-MS), we analyzed and compared the quantities of sterols in the different sections of the gut and tissues of the locust. In the gut, we identified 34 sterols which showed a patchy distribution, but with the highest composition in the foregut (55%) followed by midgut (31%) and hindgut (14%). Fed ad libitum on wheat seedlings, five sterols unique to the insect were detected. These sterols were identified as 7-dehydrocholesterol, desmosterol, fucosterol, (3β, 5α) cholesta-8, 14, 24-trien-3-ol, 4, 4-dimethyl, and (3β, 20R) cholesta-5, 24-dien-3, 20-diol with the first three having known health benefits in humans. Incubation of the fore-, mid- and hindgut with cholesterol-[4-13C] yielded eight derivatives, three of these were detected in the gut of the desert locust after it had consumed the vegetative diet but were not detected in the diet. Our study shows that the desert locust ingests phytosterols from a vegetative diet and, amplifies and metabolizes them into derivatives with potential salutary benefits and we discuss our findings in this context. PMID:25970517

  14. Predator versus Prey: Locust Looming-Detector Neuron and Behavioural Responses to Stimuli Representing Attacking Bird Predators

    PubMed Central

    Santer, Roger D.; Rind, F. Claire; Simmons, Peter J.

    2012-01-01

    Many arthropods possess escape-triggering neural mechanisms that help them evade predators. These mechanisms are important neuroethological models, but they are rarely investigated using predator-like stimuli because there is often insufficient information on real predator attacks. Locusts possess uniquely identifiable visual neurons (the descending contralateral movement detectors, DCMDs) that are well-studied looming motion detectors. The DCMDs trigger ‘glides’ in flying locusts, which are hypothesised to be appropriate last-ditch responses to the looms of avian predators. To date it has not been possible to study glides in response to stimuli simulating bird attacks because such attacks have not been characterised. We analyse video of wild black kites attacking flying locusts, and estimate kite attack speeds of 10.8±1.4 m/s. We estimate that the loom of a kite’s thorax towards a locust at these speeds should be characterised by a relatively low ratio of half size to speed (l/|v|) in the range 4–17 ms. Peak DCMD spike rate and gliding response occurrence are known to increase as l/|v| decreases for simple looming shapes. Using simulated looming discs, we investigate these trends and show that both DCMD and behavioural responses are strong to stimuli with kite-like l/|v| ratios. Adding wings to looming discs to produce a more realistic stimulus shape did not disrupt the overall relationships of DCMD and gliding occurrence to stimulus l/|v|. However, adding wings to looming discs did slightly reduce high frequency DCMD spike rates in the final stages of object approach, and slightly delay glide initiation. Looming discs with or without wings triggered glides closer to the time of collision as l/|v| declined, and relatively infrequently before collision at very low l/|v|. However, the performance of this system is in line with expectations for a last-ditch escape response. PMID:23209660

  15. Allometry indicates giant eyes of giant squid are not exceptional.

    PubMed

    Schmitz, Lars; Motani, Ryosuke; Oufiero, Christopher E; Martin, Christopher H; McGee, Matthew D; Gamarra, Ashlee R; Lee, Johanna J; Wainwright, Peter C

    2013-02-18

    The eyes of giant and colossal squid are among the largest eyes in the history of life. It was recently proposed that sperm whale predation is the main driver of eye size evolution in giant squid, on the basis of an optical model that suggested optimal performance in detecting large luminous visual targets such as whales in the deep sea. However, it is poorly understood how the eye size of giant and colossal squid compares to that of other aquatic organisms when scaling effects are considered. We performed a large-scale comparative study that included 87 squid species and 237 species of acanthomorph fish. While squid have larger eyes than most acanthomorphs, a comparison of relative eye size among squid suggests that giant and colossal squid do not have unusually large eyes. After revising constants used in a previous model we found that large eyes perform equally well in detecting point targets and large luminous targets in the deep sea. The eyes of giant and colossal squid do not appear exceptionally large when allometric effects are considered. It is probable that the giant eyes of giant squid result from a phylogenetically conserved developmental pattern manifested in very large animals. Whatever the cause of large eyes, they appear to have several advantages for vision in the reduced light of the deep mesopelagic zone.

  16. Allometry indicates giant eyes of giant squid are not exceptional

    PubMed Central

    2013-01-01

    Background The eyes of giant and colossal squid are among the largest eyes in the history of life. It was recently proposed that sperm whale predation is the main driver of eye size evolution in giant squid, on the basis of an optical model that suggested optimal performance in detecting large luminous visual targets such as whales in the deep sea. However, it is poorly understood how the eye size of giant and colossal squid compares to that of other aquatic organisms when scaling effects are considered. Results We performed a large-scale comparative study that included 87 squid species and 237 species of acanthomorph fish. While squid have larger eyes than most acanthomorphs, a comparison of relative eye size among squid suggests that giant and colossal squid do not have unusually large eyes. After revising constants used in a previous model we found that large eyes perform equally well in detecting point targets and large luminous targets in the deep sea. Conclusions The eyes of giant and colossal squid do not appear exceptionally large when allometric effects are considered. It is probable that the giant eyes of giant squid result from a phylogenetically conserved developmental pattern manifested in very large animals. Whatever the cause of large eyes, they appear to have several advantages for vision in the reduced light of the deep mesopelagic zone. PMID:23418818

  17. Comparative bio-safety and in vivo evaluation of native or modified locust bean gum-PVA IPN microspheres.

    PubMed

    Kaity, Santanu; Ghosh, Animesh

    2015-01-01

    Strategically developed natural polymer-based controlled release multiparticulate drug delivery systems have gained special interest for “spatial placement” and “temporal delivery” of drug molecules. In our earlier study, locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (LBG-PVA IPN), carboxymethylated locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (CMLBG-PVA IPN) and acrylamide grafted locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (Am-g-LBG-PVA IPN) were prepared and characterized. The present study deals with accelerating stability testing, comparative bio-safety and single dose in vivo pharmacokinetic study of all three IPN microspheres for controlled oral delivery of buflomedil hydrochloride (BH). From the stability study, it was observed that the particles were stable throughout the study period. From toxicity and biodegradability study it was proved that the microspheres were safe for internal use and complied with bio-safety criterion. From the in vivo pharmacokinetic study in rabbits, it was observed that the CMLBG-PVA IPN microspheres possessed almost similar Tmax value with BH oral suspension. However, in comparison between the LBG-PVA and Am-g-LBG-PVA IPN microspheres, the later showed well controlled release property than the first in biological condition. Thus, this type of delivery system might be useful to achieve the lofty goals of the controlled release drug delivery.

  18. Photoreceptor projections and receptive fields in the dorsal rim area and main retina of the locust eye.

    PubMed

    Schmeling, Fabian; Tegtmeier, Jennifer; Kinoshita, Michiyo; Homberg, Uwe

    2015-05-01

    In many insect species, photoreceptors of a small dorsal rim area of the eye are specialized for sensitivity to the oscillation plane of polarized skylight and, thus, serve a role in sky compass orientation. To further understand peripheral mechanisms of polarized-light processing in the optic lobe, we have studied the projections of photoreceptors and their receptive fields in the main eye and dorsal rim area of the desert locust, a model system for polarization vision analysis. In both eye regions, one photoreceptor per ommatidium, R7, has a long visual fiber projecting through the lamina to the medulla. Axonal fibers from R7 receptors of the dorsal rim area have short side branches throughout the depth of the dorsal lamina and maintain retinotopic projections to the dorsal medulla following the first optic chiasma. Receptive fields of dorsal rim photoreceptors are considerably larger (average acceptance angle 33°) than those of the main eye (average acceptance angle 2.04°) and, taken together, cover almost the entire sky. The data challenge previous reports of two long visual fibers per ommatidium in the main eye of the locust and provide data for future analysis of peripheral networks underlying polarization opponency in the locust brain.

  19. Application of sugar maple and black locust to the biomass/energy plantation concept. Final report, April 1984

    SciTech Connect

    Mroz, G.D.; Jurgensen, M.F.; Lai, Y.Z.; Liechty, H.O.; Hamlin, D.C.; Gale, M.F.; Sajak, R.L.; Stinhilb, H.M.

    1986-08-01

    Forests in the Upper Lakes States region, composed predominantly of sugar maple and red maple with a large number of stems in small diameter classes, were evaluated for conversion to biomass/energy plantations. The study included examining the use of black locust as an interplant species to improve maple productivity. Available water and phosphorus were found to be highly correlated with site index and biomass on the sites. Skidding of trees with tops intact caused widespread disruption of forest floor horizons. Natural coppice regrowth on all sites was poor. Results indicate it is not feasible to coppice natural stands of northern hardwoods on a 4-year rotation. Survival of interplanted black locust was very poor due to susceptibility to frost. The potential of black locust as a biomass species for SRIC plantations was demonstrated by the exceptional growth of surviving individuals. A provenance trial of 20 seed sources showed variability in frost resistance among seed sources. Data is presented on the wood characteristics of seven northern hardwoods species show that young sprouts have higher moisture content, seasonal moisture content variation, higher extractive and ash content, a lower specific gravity and lower thermal stability. All species evaluated are comparable in terms of major chemical composition, caloric values, and extent of gasification. 111 refs., 11 figs., 35 tabs.

  20. Paternal epigenetic effects of population density on locust phase-related characteristics associated with heat-shock protein expression.

    PubMed

    Chen, Bing; Li, Shaoqin; Ren, Qiang; Tong, Xiwen; Zhang, Xia; Kang, Le

    2015-02-01

    Many species exhibit transgenerational plasticity by which environmental cues experienced by either parent can be transmitted to their offspring, resulting in phenotypic variants in offspring to match ancestral environments. However, the manner by which paternal experiences affect offspring plasticity through epigenetic inheritance in animals generally remains unclear. In this study, we examined the transgenerational effects of population density on phase-related traits in the migratory locust Locusta migratoria. Using an experimental design that explicitly controls genetic background, we found that the effects of crowd or isolation rearing on phase plasticity could be inherited to the offspring. The isolation of gregarious locusts resulted in reduced weight in offspring eggs and altered morphometric traits in hatchlings, whereas crowding of solitarious locusts exhibited opposite effects. The consequences of density changes were transmitted by both maternal and paternal inheritance, although the expression of paternal effects was not as pronounced as that of maternal effects. Prominent expression of heat-shock proteins (Hsps), such as Hsp90, Hsp70 and Hsp20.6, could be triggered by density changes. Hsps were significantly upregulated upon crowding but downregulated upon isolation. The variation in parental Hsp expression was also transmitted to the offspring, in which the pattern of inheritance was consistent with that of phase characteristics. These results revealed a paternal effect on phase polyphenism and Hsp expression induced by population density, and defined a model system that could be used to study the paternal epigenetic inheritance of environmental changes.

  1. Photogrammetric reconstruction of high-resolution surface topographies and deformable wing kinematics of tethered locusts and free-flying hoverflies

    PubMed Central

    Walker, Simon M.; Thomas, Adrian L.R.; Taylor, Graham K.

    2008-01-01

    Here, we present a suite of photogrammetric methods for reconstructing insect wing kinematics, to provide instantaneous topographic maps of the wing surface. We filmed tethered locusts (Schistocerca gregaria) and free-flying hoverflies (Eristalis tenax) using four high-speed digital video cameras. We digitized multiple natural features and marked points on the wings using manual and automated tracking. Epipolar geometry was used to identify additional points on the hoverfly wing outline which were anatomically indistinguishable. The cameras were calibrated using a bundle adjustment technique that provides an estimate of the error associated with each individual data point. The mean absolute three-dimensional measurement error was 0.11 mm for the locust and 0.03 mm for the hoverfly. The error in the angle of incidence was at worst 0.51° (s.d.) for the locust and 0.88° (s.d.) for the hoverfly. The results we present are of unprecedented spatio-temporal resolution, and represent the most detailed measurements of insect wing kinematics to date. Variable spanwise twist and camber are prominent in the wingbeats of both the species, and are of such complexity that they would not be adequately captured by lower resolution techniques. The role of spanwise twist and camber in insect flight has yet to be fully understood, and accurate insect wing kinematics such as we present here are required to be sure of making valid predictions about their aerodynamic effects. PMID:18682361

  2. Individual Pheromone Signature in Males: Prerequisite for Pheromone-Mediated Mate Assessment in the Central American Locust, Schistocerca Piceifrons.

    PubMed

    Stahr, Christiane; Seidelmann, Karsten

    2016-12-01

    Living in high-density groups of animals has advantages and disadvantages for mating. The advantage of facilitated mate finding is compromised by difficulties in protecting a suitable partner from competitors. Thus, males regularly are faced with increased competition for sperm, and females with harassment by males at high population densities. To cope with these problems, mating tactics and mate choice mechanisms have to be adjusted. An adaptation to gregarious condition observed in locusts includes the use of male-emitted pheromones. Males of the Central American locust, Schistocerca piceifrons, release sex-specific volatiles, which were identified as phenethyl alcohol (synonym: phenyl-ethyl-alcohol, 2-phenyl-1-ethanol, 2-phenylethanol, PEA), (Z)-3-nonen-1-ol (3-Nol), and (Z)-2-octen-1-ol (2-Ool). The emission of the two major compounds, PEA and 3-Nol, was restricted to crowded conditions. Furthermore, the release of both volatiles was coupled to males reaching sexual maturity, indicating a function in reproductive behavior. However, neither the single substances nor their mixtures were attractive or repellent to the locusts. Instead, females prefer the sperm of high pheromone-emitting males to fertilize their ova. In this way, the male-specific volatiles act as mate assessment pheromones utilized in a context of cryptic female choice. This function is well supported by the highly variable but individual-specific emission rates of the three compounds. Schistocerca piceifrons males release a virtually unique personal pheromone signature, a prerequisite for mate assessment pheromones.

  3. Flight and walking in locusts-cholinergic co-activation, temporal coupling and its modulation by biogenic amines.

    PubMed

    Rillich, Jan; Stevenson, Paul A; Pflueger, Hans-Joachim

    2013-01-01

    Walking and flying in locusts are exemplary rhythmical behaviors generated by central pattern generators (CPG) that are tuned in intact animals by phasic sensory inputs. Although these two behaviors are mutually exclusive and controlled by independent CPGs, leg movements during flight can be coupled to the flight rhythm. To investigate potential central coupling between the underlying CPGs, we used the muscarinic agonist pilocarpine and the amines octopamine and tyramine to initiate fictive flight and walking in deafferented locust preparations. Our data illustrate that fictive walking is readily evoked by comparatively lower concentrations of pilocarpine, whereas higher concentrations are required to elicit fictive flight. Interestingly, fictive flight did not suppress fictive walking so that the two patterns were produced simultaneously. Frequently, leg motor units were temporally coupled to the flight rhythm, so that each spike in a step cycle volley occurred synchronously with wing motor units firing at flight rhythm frequency. Similarly, tyramine also induced fictive walking and flight, but mostly without any coupling between the two rhythms. Octopamine in contrast readily evoked fictive flight but generally failed to elicit fictive walking. Despite this, numerous leg motor units were recruited, whereby each was temporarily coupled to the flight rhythm. Our results support the notion that the CPGs for walking and flight are largely independent, but that coupling can be entrained by aminergic modulation. We speculate that octopamine biases the whole motor machinery of a locust to flight whereas tyramine primarily promotes walking.

  4. Phase-specific responses to different qualities of food in the desert locust, Schistocerca gregaria: developmental, morphological and reproductive characteristics.

    PubMed

    Maeno, Koutaro; Tanaka, Seiji

    2011-04-01

    Solitarious female adults are known to produce smaller hatchlings than those produced by gregarious adults of the desert locust, Schistocerca gregaria. This study investigated developmental, morphological and reproductive responses to different qualities of food in hatchlings of different phases. Mortality was higher, the duration of nymphal development longer and adult body weight lighter with a low-quality food than a high-quality food. Gregarious hatchlings showed better survivorship, grew faster and became larger adults than did solitarious ones. The incidence of locusts exhibiting extra molting, which was typically observed in the solitarious phase, was dramatically increased when a low-quality food was given to the solitarious hatchlings. Low-quality food caused locusts to shift morphometric ratios toward the values typical of gregarious forms; smaller F/C (hind femur length/maximum head width) and larger E/F (elytra length/hind femur length). Solitarious hatchlings grown at either high- or low-quality foods and then given high-quality food after adult emergence revealed that food qualities during the nymphal stage influence their progeny quality and quantity via adult body size that influenced reproductive performance. Female adults showed an overshooting response to a shift from low- to high-quality food by increasing egg production that was specific to body size. This study may suggest that gregarious hatchlings are better adapted to adverse food conditions than solitarious counterparts and extra molting is induced even among gregarious hatchlings under poor food conditions.

  5. Comparative mitochondrial proteomic, physiological, biochemical and ultrastructural profiling reveal factors underpinning salt tolerance in tetraploid black locust (Robinia pseudoacacia L.).

    PubMed

    Luo, Qiuxiang; Peng, Mu; Zhang, Xiuli; Lei, Pei; Ji, Ximei; Chow, Wahsoon; Meng, Fanjuan; Sun, Guanyu

    2017-08-22

    Polyploidy is an important phenomenon in plants because of its roles in agricultural and forestry production as well as in plant tolerance to environmental stresses. Tetraploid black locust (Robinia pseudoacacia L.) is a polyploid plant and a pioneer tree species due to its wide ranging adaptability to adverse environments. To evaluate the ploidy-dependent differences in leaf mitochondria between diploid and tetraploid black locust under salinity stress, we conducted comparative proteomic, physiological, biochemical and ultrastructural profiling of mitochondria from leaves. Mitochondrial proteomic analysis was performed with 2-DE and MALDI-TOF-MS, and the ultrastructure of leaf mitochondria was observed by transmission electron microscopy. According to 2-DE analysis, 66 proteins that responded to salinity stress significantly were identified from diploid and/or tetraploid plants and classified into 9 functional categories. Assays of physiological characters indicated that tetraploids were more tolerant to salinity stress than diploids. The mitochondrial ultrastructure of diploids was damaged more severely under salinity stress than that of tetraploids. Tetraploid black locust possessed more tolerance of, and ability to acclimate to, salinity stress than diploids, which may be attributable to the ability to maintain mitochondrial structure and to trigger different expression patterns of mitochondrial proteins during salinity stress.

  6. Development of histamine-immunoreactivity in the Central nervous system of the two locust species Schistocerca gregaria and Locusta migratoria.

    PubMed

    Pätschke, Arne; Bicker, Gerd

    2011-10-01

    Locusts are attractive model preparations for cellular investigations of neurodevelopment. In this study, we investigate the immunocytochemical localization of histamine in the developing ventral nerve cord of two locust species, Schistocerca gregaria and Locusta migratoria. Histamine is the fast neurotransmitter of photoreceptor neurons in the compound eye of insects, but it is also synthesized in interneurons of the central nervous system. In the locust ventral nerve cord, the pattern of histamine-immunoreactive neurons follows a relatively simple bauplan. The histaminergic system comprises a set of single, ascending projection neurons that are segmentally arranged in almost every neuromere. The neurons send out their axons anteriorly, forming branches and varicosities throughout the adjacent ganglia. In the suboesophageal ganglion, the cell bodies lie in a posteriolateral position. The prothoracic ganglion lacks histaminergic neurons. In the posterior ganglia of the ventral nerve cord, the somata of the histaminergic neurons are ventromedially positioned. Histamine-immunoreactivity starts around 50% of embryonic development in interneurons of the brain. Subsequently, the neurons of the more posterior ganglia of the ventral nerve cord become immunoreactive. From 60% embryonic development, the pattern of soma staining in the nerve cord appears mature. Around 65% of embryonic development, the photoreceptor cells show histamine-immunoreactivity. The histaminergic innervation of the neuropile develops from the central branches toward the periphery of the ganglia and is completed right before hatching.

  7. Some soil properties on coal mine spoils reclaimed with black locust (Robinia pceudoacacia L.) and umbrella pine (Pinus pinea L.) in Agacli-Istanbul.

    PubMed

    Keskin, Tahir; Makineci, Ender

    2009-12-01

    This study performed on randomly selected seven sample plots in leguminous black locust (Robinia pceudoacacia L.) plantations and five sample plots in umbrella pine (Pinus pinea L.) plantations on coal mine soil/spoils. Soil samples were taken from eight different soil depths (0-1, 1-3, 3-5, 5-10, 10-20, 20-30, 30-40, and 40-50 cm) into the soil profile. On soil samples, bulk density, fine soil fraction (Ø < 2 mm), sand, silt and clay rates, soil acidity (pH), organic carbon (C(org)), and total nitrogen (N(t)) contents were investigated. Also, some forest floor properties (unit mass, organic matter, and total nitrogen) were determined, and results were compared statistically between umbrella pine and black locust. As a result, 17 years after plantations, total forest floor accumulation determined as 6,107 kg ha(-1) under black locust compared to 13,700 kg ha(-1) under umbrella pine. The more rapid transformation of leguminous black locust forest floor creates organic carbon that migrates further into the mineral profile, and rapid accumulation of C and N in the soil profile was registered. Slower transformation processes of forest floor under umbrella pine result in lower soil N ratio and greater quantity of forest floor. Higher soil pH under leguminous black locust was determined significantly than umbrella pine. In conclusion, the composition of symbiotic nitrogen fixation of black locust appears to be a possible factor favoring carbon and nitrogen accumulation and, consequently, soil development. Clearly, both tree species have favorable impacts on initial soil formation. The umbrella pine generates the more forest floor layer; in contrast, black locust forest floor incorporates into the soil more rapidly and significantly increases soil nitrogen in upper soil layers.

  8. Giant magnetostrictive composites

    NASA Astrophysics Data System (ADS)

    Duenas, Terrisa Ann

    The limitation of magnetostrictive composites has been in their low magnetostrictive response when compared to their monolithic counterparts. In this dissertation research is presented describing the methods and analysis used to create a giant magnetostrictive composite (GMC) producing giant strains at low fields, exhibiting magnetization ``jumping'' and the ΔE effect. This composite combines the giant magnetostrictive material, Terfenol-D (Tb0.3Dy0.7Fe2) in particle form, with a nonmetallic binder and is capable of producing strains (at room temperature) exceeding 1000 ppm at a nominal field of 1.5 kOe mechanically unloaded and 1200 ppm at 8 MPa preload (2.5 kOe). Several studies leading to the high response of this composite are presented. A connectivity study shows that a [1-3] connected composite produces 50% more strain than a [0-3] composite. A resin study indicates that the lower the viscosity of the resin, the greater the magnetostrictive response; this is attributed to the removal of voids during degassing. A void study correlates the increase in voids to the decrease in strain response. A model is used to correlate analysis with experimental results within 10% accuracy and shows that an optimal volume fraction exists based on the properties of the binder. Using a Polyscience Spurr low- viscosity (60 cps) binder this volume fraction is nominally 20%; this optimum is attributed to the balance of epoxy contracting on the particle (built-in preload) and the actuation delivered by the magnetostrictive material. In addition to the connectivity, resin, void, and volume-fraction study, particle size and gradation studies are presented. Widely dispersed (<106, <212, <300 μm), narrowly dispersed (<45, (90-106), (275-300) μm), and an optimized bimodal (18.7% of (45-90) μm with 81.3% of (250-300) μm) particle distributions are studied. Results show that the larger the particle size, the higher the magnetostrictive response; this is attributed to the reduction of

  9. On to the Ice Giants

    NASA Astrophysics Data System (ADS)

    Reh, Kim; Hofstdater, Mark; Simon, Amy; Elliott, John

    2017-04-01

    Voyager 2 mission flew by Uranus in 1986 and Neptune in 1989 resulting in stunning remote observations not previously accessible from the ground. There have been no follow-up space flight missions to examine ice giants and, as a result there are significant gaps in our understanding of planetary formation and evolution. This gap not only affects our understanding of our own solar system but also our understanding of exoplanets; the majority of planets discovered around other stars are thought to be ice giants. Ice Giants are likely to be far more abundant in our galaxy than previously thought. The U.S. 2011 Planetary Science Decadal Survey committee recognized the importance of Uranus and Neptune, and prioritized the exploration of the Ice Giants. Following from this, NASA and ESA have recently completed a study of candidate missions to Uranus and Neptune, the so-called ice giant planets. The intent was to examine what could be accomplished within the budget realities of the predictable future. This "Pre-Decadal Study," focused on opportunities for missions launching in the 2020's and early 2030's. This paper presents results from the Ice Giants study (science, architectures and technologies) and concludes that compelling and affordable missions to the Ice Giants are within our reach.

  10. Giant magnetofossils and hyperthermal events

    NASA Astrophysics Data System (ADS)

    Chang, Liao; Roberts, Andrew P.; Williams, Wyn; Fitz Gerald, John D.; Larrasoaña, Juan C.; Jovane, Luigi; Muxworthy, Adrian R.

    2012-10-01

    Magnetotactic bacteria biomineralize magnetic minerals with precisely controlled size, morphology, and stoichiometry. These cosmopolitan bacteria are widely observed in aquatic environments. If preserved after burial, the inorganic remains of magnetotactic bacteria act as magnetofossils that record ancient geomagnetic field variations. They also have potential to provide paleoenvironmental information. In contrast to conventional magnetofossils, giant magnetofossils (most likely produced by eukaryotic organisms) have only been reported once before from Paleocene-Eocene Thermal Maximum (PETM; 55.8 Ma) sediments on the New Jersey coastal plain. Here, using transmission electron microscopic observations, we present evidence for abundant giant magnetofossils, including previously reported elongated prisms and spindles, and new giant bullet-shaped magnetite crystals, in the Southern Ocean near Antarctica, not only during the PETM, but also shortly before and after the PETM. Moreover, we have discovered giant bullet-shaped magnetite crystals from the equatorial Indian Ocean during the Mid-Eocene Climatic Optimum (˜40 Ma). Our results indicate a more widespread geographic, environmental, and temporal distribution of giant magnetofossils in the geological record with a link to "hyperthermal" events. Enhanced global weathering during hyperthermals, and expanded suboxic diagenetic environments, probably provided more bioavailable iron that enabled biomineralization of giant magnetofossils. Our micromagnetic modelling indicates the presence of magnetic multi-domain (i.e., not ideal for navigation) and single domain (i.e., ideal for navigation) structures in the giant magnetite particles depending on their size, morphology and spatial arrangement. Different giant magnetite crystal morphologies appear to have had different biological functions, including magnetotaxis and other non-navigational purposes. Our observations suggest that hyperthermals provided ideal conditions for

  11. [Giant esophageal fibrovascular polyp].

    PubMed

    Palacios, Fernando; Contardo, Carlos; Guevara, Jorge; Vera, Augusto; Aguilar, Luis; Huamán, Manuel; Palomino, Américo; Yabar, Alejandro

    2003-01-01

    Fibrovascular polyps are extremely rare benign neoplasias of the esophagus, which usually originate in the lower cricoid area. They do not produce any discomfort in the patient for a long time, however it may make itself evident by the patient's regurgitation of the polyp, producing asphyxia or, more frequently, dysphagia. The case of a 58 year old male patient is presented herein, with a 9 month record of dysphagia, weight loss and intermittent melena. The barium x-ray showed a distended esophagus, with a tumor running from the upper esophageal sphincter to the cardia. The endoscopy confirmed the presence of a pediculated tumor, implanted in the cervical esophagus. Surgeons suspected the potential malignancy of the tumor and performed a transhiatal esophagectomy. The final pathologic diagnosis was giant fibrovascular esophageal polyp.

  12. A giant Ordovician anomalocaridid.

    PubMed

    Van Roy, Peter; Briggs, Derek E G

    2011-05-26

    Anomalocaridids, giant lightly sclerotized invertebrate predators, occur in a number of exceptionally preserved early and middle Cambrian (542-501 million years ago) biotas and have come to symbolize the unfamiliar morphologies displayed by stem organisms in faunas of the Burgess Shale type. They are characterized by a pair of anterior, segmented appendages, a circlet of plates around the mouth, and an elongate segmented trunk lacking true tergites with a pair of flexible lateral lobes per segment. Disarticulated body parts, such as the anterior appendages and oral circlet, had been assigned to a range of taxonomic groups--but the discovery of complete specimens from the middle Cambrian Burgess Shale showed that these disparate elements all belong to a single kind of animal. Phylogenetic analyses support a position of anomalocaridids in the arthropod stem, as a sister group to the euarthropods. The anomalocaridids were the largest animals in Cambrian communities. The youngest unequivocal examples occur in the middle Cambrian Marjum Formation of Utah but an arthropod retaining some anomalocaridid characteristics is present in the Devonian of Germany. Here we report the post-Cambrian occurrence of anomalocaridids, from the Early Ordovician (488-472 million years ago) Fezouata Biota in southeastern Morocco, including specimens larger than any in Cambrian biotas. These giant animals were an important element of some marine communities for about 30 million years longer than previously realized. The Moroccan specimens confirm the presence of a dorsal array of flexible blades attached to a transverse rachis on the trunk segments; these blades probably functioned as gills.

  13. Giant Hedge-Hogs: Spikes on Giant Gravitons

    SciTech Connect

    Sadri, D

    2004-01-28

    We consider giant gravitons on the maximally supersymmetric plane-wave background of type IIB string theory. Fixing the light-cone gauge, we work out the low energy effective light-cone Hamiltonian of the three-sphere giant graviton. At first order, this is a U(1) gauge theory on R x S{sup 3}. We place sources in this effective gauge theory. Although non-vanishing net electric charge configurations are disallowed by Gauss' law, electric dipoles can be formed. From the string theory point of view these dipoles can be understood as open strings piercing the three-sphere, generalizing the usual BIons to the giant gravitons, BIGGons. Our results can be used to give a two dimensional (worldsheet) description of giant gravitons, similar to Polchinski's description for the usual D-branes, in agreement with the discussions of hep-th/0204196.

  14. Giant resonances: Progress, new directions, new challenges

    SciTech Connect

    Bertrand, J.R.; Beene, J.R.

    1989-01-01

    A review of some recent developments in the field of giant multipole resonances is presented. Particular emphasis is placed on directions that the authors feel will be followed in this field during the next several years. In particular, the use of high-energy heavy ions to excite the giant resonances is shown to provide exciting new capabilities for giant resonance studies. Among subjects covered are: Coulomb excitation of giant resonances, photon decay of giant resonances, the recent controversy over the identity of the giant monopole resonance, the most recent value for incompressibility of nuclear matter from analysis of giant monopole data, the isospin character of the 63 A/sup /minus/1/3/ GQR, agreement between (e,e/prime/) and (hadron, hadron/prime/) excitation of the giant quadrupole resonance, prospects for multiphonon giant resonance observation, and isolation of the isovector giant quadrupole resonance. 55 refs., 23 figs., 4 tabs.

  15. Dynamics of neurons controlling movements of a locust hind leg. III. Extensor tibiae motor neurons.

    PubMed

    Newland, P L; Kondoh, Y

    1997-06-01

    Imposed movements of the apodeme of the femoral chordotonal organ (FeCO) of the locust hind leg elicit resistance reflexes in extensor and flexor tibiae motor neurons. The synaptic responses of the fast and slow extensor tibiae motor neurons (FETi and SETi, respectively) and the spike responses of SETi were analyzed with the use of the Wiener kernel white noise method to determine their response properties. The first-order Wiener kernels computed from soma recordings were essentially monophasic, or low passed, indicating that the motor neurons were primarily sensitive to the position of the tibia about the femorotibial joint. The responses of both extensor motor neurons had large nonlinear components. The second-order kernels of the synaptic responses of FETi and SETi had large on-diagonal peaks with two small off-diagonal valleys. That of SETi had an additional elongated valley on the diagonal, which was accompanied by two off-diagonal depolarizing peaks at a cutoff frequency of 58 Hz. These second-order components represent a half-wave rectification of the position-sensitive depolarizing response in FETi and SETi, and a delayed inhibitory input to SETi, indicating that both motor neurons were directionally sensitive. Model predictions of the responses of the motor neurons showed that the first-order (linear) characterization poorly predicted the actual responses of FETi and SETi to FeCO stimulation, whereas the addition of the second-order (nonlinear) term markedly improved the performance of the model. Simultaneous recordings from the soma and a neuropilar process of FETi showed that its synaptic responses to FeCO stimulation were phase delayed by about -30 degrees at 20 Hz, and reduced in amplitude by 30-40% when recorded in the soma. Similar configurations of the first and second-order kernels indicated that the primary process of FETi acted as a low-pass filter. Cross-correlation between a white noise stimulus and a unitized spike discharge of SETi again

  16. Theories of Giant Planet Formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1998-01-01

    An overview of current theories of planetary formation, with emphasis on giant planets, is presented. The most detailed models are based upon observations of our own Solar System and of young stars and their environments. While these models predict that rocky planets should form around most single stars, the frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Most models for extrasolar giant planets suggest that they formed as did Jupiter and Saturn (in nearly circular orbits, far enough from the star that ice could), and subsequently migrated to their current positions, although some models suggest in situ formation.

  17. Lichens On Galapagos Giant Tortoises.

    PubMed

    Hendrickson, J R; Weber, W A

    1964-06-19

    The association of Physcia picta with the giant Galdpagos tortoise is believed to be the first reported occurrence of lichens on land animals. The habitat is restricted to specific sites on the carapace of male tortoises.

  18. Landscape of the lost giants

    NASA Astrophysics Data System (ADS)

    2013-09-01

    The Pleistocene megafauna extinction erased a group of remarkable animals. Whether humans had a prominent role in the extinction remains controversial, but it is emerging that the disappearance of the giants has markedly affected the environment.

  19. What Is Giant Cell Arteritis?

    MedlinePlus

    ... 01, 2017 Giant cell arteritis (GCA) is an inflammation (swelling) of the arteries, which are the blood ... help nourish your eyes, reduced blood flow can cause sudden, painless vision loss. This condition is called ...

  20. Pharma giants swap research programs.

    PubMed

    2014-07-01

    Pharmaceutical giants Novartis and GlaxoSmithKline (GSK) agreed in late April to swap some assets, with Novartis handing off its vaccine business to GSK and getting most of the British company's cancer portfolio in return.

  1. Giant sacrolumbar meningioma. Case report.

    PubMed

    Feldenzer, J A; McGillicuddy, J E; Hopkins, J W

    1990-06-01

    A case of giant sacral meningioma with presacral and lumbar extension is presented. The difficulties in diagnosis and management are emphasized including the staged multidisciplinary surgical approaches and preoperative tumor embolization.

  2. Atmospheres of Extrasolar Giant Planets

    NASA Technical Reports Server (NTRS)

    Marley, Mark

    2006-01-01

    The next decade will almost certainly see the direct imaging of extrasolar giant planets around nearby stars. Unlike purely radial velocity detections, direct imaging will open the door to characterizing the atmosphere and interiors of extrasola planets and ultimately provide clues on their formation and evolution through time. This process has already begun for the transiting planets, placing new constraints on their atmospheric structure, composition, and evolution. Indeed the key to understanding giant planet detectability, interpreting spectra, and constraining effective temperature and hence evolution-is the atmosphere. I will review the universe of extrasolar giant planet models, focusing on what we have already learned from modeling and what we will likely be able to learn from the first generation of direct detection data. In addition to these theoretical considerations, I will review the observations and interpretation of the - transiting hot Jupiters. These objects provide a test of our ability to model exotic atmospheres and challenge our current understanding of giant planet evolution.

  3. Theories of Giant Planet Formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1998-01-01

    An overview of current theories of planetary formation, with emphasis on giant planets, is presented. The most detailed models are based upon observations of our own Solar System and of young stars and their environments. While these models predict that rocky planets should form around most single stars, the frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Most models for extrasolar giant planets suggest that they formed as did Jupiter and Saturn (in nearly circular orbits, far enough from the star that ice could), and subsequently migrated to their current positions, although some models suggest in situ formation.

  4. Giant cell arteritis: a review

    PubMed Central

    Patil, Pravin; Karia, Niral; Jain, Shaifali; Dasgupta, Bhaskar

    2013-01-01

    Giant cell arteritis is the most common vasculitis in Caucasians. Acute visual loss in one or both eyes is by far the most feared and irreversible complication of giant cell arteritis. This article reviews recent guidelines on early recognition of systemic, cranial, and ophthalmic manifestations, and current management and diagnostic strategies and advances in imaging. We share our experience of the fast track pathway and imaging in associated disorders, such as large-vessel vasculitis. PMID:28539785

  5. Background visual motion affects responses of an insect motion-sensitive neuron to objects deviating from a collision course.

    PubMed

    Yakubowski, Jasmine M; McMillan, Glyn A; Gray, John R

    2016-05-01

    Stimulus complexity affects the response of looming sensitive neurons in a variety of animal taxa. The Lobula Giant Movement Detector/Descending Contralateral Movement Detector (LGMD/DCMD) pathway is well-characterized in the locust visual system. It responds to simple objects approaching on a direct collision course (i.e., looming) as well as complex motion defined by changes in stimulus velocity, trajectory, and transitions, all of which are affected by the presence or absence of background visual motion. In this study, we focused on DCMD responses to objects transitioning away from a collision course, which emulates a successful locust avoidance behavior. We presented each of 20 locusts with a sequence of complex three-dimensional visual stimuli in simple, scattered, and progressive flow field backgrounds while simultaneously recording DCMD activity extracellularly. DCMD responses to looming stimuli were generally characteristic irrespective of stimulus background. However, changing background complexity affected, peak firing rates, peak time, and caused changes in peak rise and fall phases. The DCMD response to complex object motion also varied with the azimuthal approach angle and the dynamics of object edge expansion. These data fit with an existing correlational model that relates expansion properties to firing rate modulation during trajectory changes. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  6. Giants in the Local Region

    NASA Astrophysics Data System (ADS)

    Luck, R. Earle; Heiter, Ulrike

    2007-06-01

    We present parameter and abundance data for a sample of 298 nearby giants. The spectroscopic data for this work have a resolution of R~60,000, S/N>150, and spectral coverage from 475 to 685 nm. Overall trends in the Z>10 abundances are dominated by Galactic chemical evolution, while the light-element abundances are influenced by stellar evolution, as well as Galactic evolution. We find several super-Li stars in our sample and confirm that Li abundances in the first giant branch are related to mixing depths. Once astration of lithium on the main sequence along with the overall range of main-sequence lithium abundances are taken into account, the lithium abundances of the giants are not dramatically at odds with the predictions of standard stellar evolution. We find the giants to be carbon-diluted in accord with standard stellar evolution and that the carbon and oxygen abundances determined for the local giants are consistent with those found in local field dwarfs. We find that there is evidence for systematic carbon variations in the red giant clump in the sense that the blue side of the clump is carbon-poor (more diluted) than the red side.

  7. Kuiper Prize: Giant Planet Atmospheres

    NASA Astrophysics Data System (ADS)

    Ingersoll, Andrew P.

    2007-10-01

    The study of giant planet atmospheres is near and dear to me, for several reasons. First, the giant planets are photogenic; the colored clouds are great tracers, and one can make fantastic movies of the atmosphere in motion. Second, the giant planets challenge us with storms that last for hundreds of years and winds that blow faster the farther you go from the sun. Third, they remind us of Earth with their hurricanes, auroras, and lightning, but they also are the link to the 200 giant planets that have been discovered around other stars. This talk will cover the past, present, and future (one hopes) of giant planet research. I will review the surprises of the Voyager and Galileo eras, and will discuss what we are learning now from the Cassini orbiter. I will review the prospects for answering the outstanding questions like: Where's the water? What is providing the colors of the clouds? How deep do the features extend? Where do the winds get their energy? What is the role of the magnetic field? Finally, I will briefly discuss how extrasolar giant planets compare with objects in our own solar system.

  8. Controlled release of Lactobacillus rhamnosus biofilm probiotics from alginate-locust bean gum microcapsules.

    PubMed

    Cheow, Wean Sin; Kiew, Tie Yi; Hadinoto, Kunn

    2014-03-15

    Chitosan-coated alginate microcapsules containing high-density biofilm Lactobacillus rhamnosus have been previously shown to exhibit higher freeze drying- and thermal-tolerance than their planktonic counterparts. However, their cell release profile remains poor due to the capsules' susceptibility to the gastric environment. Herein the effects of adding locust bean (LB) and xanthan (XT) gums to alginate (AGN) capsules on the stress tolerance and cell release profiles in simulated gastrointestinal fluids are investigated. Compared to the AGN-only capsules, the AGN-LB capsules exhibit improved stress tolerance (i.e. ≈ 6x for freeze drying, 100x for thermotolerance, 10x for acid), whereas the AGN-XT capsules only improve the acid tolerance. Importantly, the AGN-LB capsules possess the optimal cell release profile with a majority of cells released in the simulated intestinal juice than in the gastric juice. The AGN-LB capsules' superiority is attributed to their stronger interaction with the chitosan coating and high swelling capacity, thus delaying their bulk dissolution. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Elucidation of hydration dynamics of locust bean gum-collagen composites by impedance and thermoporometry.

    PubMed

    Kanungo, Ivy; Fathima, Nishter Nishad; Jonnalagadda, Raghava Rao; Unni Nair, Balachandran

    2014-03-15

    The intricacy of the different parameters involved in the hydration dynamics of collagen influences its performance as biomaterials. This work presents the molecular motions of collagen originating from the solvents and locust bean gum (LBG), which reveal the changes in solvation dynamics of the biopolymers affecting the surface as well as interfacial properties. Water, as a probe liquid bound in collagen has been investigated using a combination of thermoporometry, ATR-FTIR, circular dichroic spectroscopy, dielectric spectroscopy and SEM to explore the influence of LBG on collagen with respect to static and dynamic behaviour. The relaxation process of collagen in the frequency range of 0.01 Hz to 10(5)Hz and thermoporometry results indicate that the interfacial hydration dynamics are dependent on the applied concentration of LBG. This investigation explicitly reflects the rearrangements of the structural water clusters around the charged amino acids of collagen. These results can be employed to redesign the approach towards the development of collagen based biomaterials.

  10. Control of Drug Diffusion Behavior of Xanthan and Locust Bean Gum Gel by Agar Gel.

    PubMed

    Hishikawa, Yoshihiro; Kakino, Yukari; Tsukamoto, Hoshi; Tahara, Kohei; Onodera, Risako; Takeuchi, Hirofumi

    2016-01-01

    Oral gel formulations are known as easy to administer drug products for patients who have problems taking drugs including those with conditions such as dysphagia. In addition, there are numerous commercially available oral gel products, most of which are immediate-release formulation that release their pharmaceutical ingredient content by diffusion. This study is focused on developing oral gel formulations that reduce the dosing frequency and dosage compared to the conventional types. This is with the aim of facilitating the use of gel formulations for producing pharmaceutical agents with different dose regimens, thereby enhancing patient convenience. Here, we used naturally derived high-molecular-weight agar (Ag), xanthan gum (Xa), and locust bean gum (Lo) as gel bases to prepare a variety of gel membranes, and evaluated the diffusion coefficient of the model substances. The result revealed that the Ag content in the Xa-Lo combination gel concentration-dependently increased the diffusion coefficient. Moreover, these findings were applied in an attempt to mask the taste of intensely bitter levofloxacin. The results indicated that the Xa-Lo combination gel exhibited a significantly superior masking effect to that of the Ag gel. This study demonstrates the feasibility of using oral gel formulations to modulate the controlled-release functionality of pharmaceutical agents.

  11. Optimization of reaction conditions by RSM and structure characterization of sulfated locust bean gum.

    PubMed

    Wang, Junlong; Yang, Ting; Tian, Jia; Liu, Wenxi; Jing, Fan; Yao, Jian; Zhang, Ji; Lei, Ziqiang

    2014-12-19

    Sulfated derivatives of galactomannan from locust bean gum (LBG) with the degree of substitution (DS) of 0.34-1.07 were synthesized using chlorosulfonic acid/pyridine (CSA/Py) method. Box-Behnken design (BBD) of response surface methodology (RSM) was employed to optimize the reaction conditions. Results of FT-IR and X-ray photoelectron spectroscopy (XPS) indicated that SO3H groups were widely present in sulfated LBG (SLBG). (13)C NMR result revealed that sulfation had occurred and C-6 substitution was predominant in SLBG. All sulfated samples showed a decrease in Mw and more broad molar mass distribution in size exclusion chromatography combined with laser light scattering (SEC-LLS) analysis. Results of MW - [Formula: see text] showed a decrease in fractal dimension (df) value. Laser light scattering results also showed a conformation transition from a compact chain conformation of branched clusters to a random coil conformation of SLBG. Compared to LBG and SLBG with low DS and molecular weight, SLBG2 exhibited an internal structure of random coil with a DS of 1.07. DS and molecular weight had great influence on its conformation in aqueous solution. Our results confirmed that the degradation of polysaccharide and SO3H groups improved significantly the stiffness of the chains due to the electrostatic effect.

  12. Locust bean gum in the development of sustained release mucoadhesive macromolecules of aceclofenac.

    PubMed

    Prajapati, Vipul D; Jani, Girish K; Moradiya, Naresh G; Randeria, Narayan P; Maheriya, Pankaj M; Nagar, Bhanu J

    2014-11-26

    The study shows the development and optimization of locust bean gum (LBG)-alginate mucoadhesive macromolecules containing aceclofenac through ionotropic-gelation using 3(2) factorial design. The effect of amount of LBG and sodium alginate on drug entrapment efficiency (%DEE), % mucoadhesion at 8h (M8) and % in vitro drug release at 10h (%Q10h) were optimized. The percentage yield, average size and DEE of macromolecules were found within the range of 93.19 to 96.65%, 1.328 ± 0.11 to 1.428 ± 0.13 μm, and 56.37 to 68.54%, respectively. The macromolecules were also characterized by SEM, FTIR and DSC. The in vitro drug release from these macromolecules (84.95 ± 2.02 to 95.33 ± 1.56% at 10h) exhibited sustained release (first-order) pattern with super case-II transport mechanism. The swelling and mucoadhesivity of these macromolecules were affected by pH of the medium. The design established the role of derived polynomial equations and plots in predicting the values of dependent variables for the preparation and optimization.

  13. Alginate beads of Captopril using galactomannan containing Senna tora gum, guar gum and locust bean gum.

    PubMed

    Pawar, Harshal A; Lalitha, K G; Ruckmani, K

    2015-05-01

    Gastro-retentive Captopril loaded alginate beads were prepared by an ionotropic gelation method using sodium alginate in combination with natural gums containing galactomannans (Senna tora seed gum, guar gum and locust bean gum) in the presence of calcium chloride. The process variables such as concentration of sodium alginate/natural polymer, concentration of calcium chloride, curing time, stirring speed and drying condition were optimized. Prepared beads were evaluated for various parameters such as flow property, drug content and entrapment efficiency, size and shape, and swelling index. Surface morphology of the beads was studied using scanning electron microscopy. In vitro mucoadhesion and in vitro drug release studies were carried out on the prepared beads. From the entrapment efficiency and dissolution study, it was concluded that galactomannans in combination with sodium alginate show sustained release property. The bead formulation F4 prepared using combination of sodium alginate and guar gums in the ratio 2:1 showed satisfactory sustained release for 12h. The release of Captopril from the prepared beads was found to be controlled by the swelling of the polymer followed by drug diffusion through the swelled polymer and slow erosion of the beads.

  14. Octopamine mediated relaxation of maintained and catch tension in locust skeletal muscle.

    PubMed Central

    Evans, P D; Siegler, M V

    1982-01-01

    1. The modulatory actions of an identified octopaminergic neurone (DUMETi) that projects to the extensor-tibiae muscle of the locust hind leg depend upon the frequency of stimulation of the slow motoneurone (SETi) to this muscle. 2. At low frequencies of SETi stimulation (1Hz and below) the predominant modulatory effects are increases in the amplitude and relaxation rate of twitch tension. At higher frequencies, where twitches summate but tetanus is incomplete (up to 20 Hz), the reduction of maintained tension becomes considerably more important. 3. Both octopamine application and DUMETi stimulation reduce the amount of catch tension displayed by the extensor muscle when SETi is fired in a variety of different stimulus patterns. The extensor-tibiae muscle is itself 'pattern sensitive' since is shows a 'positive spacing effect' when SETi is stimulated at an average frequency of 1 Hz. 4. It is suggested that a primary function of DUMETi is to change the response of the muscle from one that favours maintenance of posture to one that favours rapid changes in joint position or force, such as might occur during locomotion. PMID:6808122

  15. Octopamine mediated relaxation of maintained and catch tension in locust skeletal muscle.

    PubMed

    Evans, P D; Siegler, M V

    1982-03-01

    1. The modulatory actions of an identified octopaminergic neurone (DUMETi) that projects to the extensor-tibiae muscle of the locust hind leg depend upon the frequency of stimulation of the slow motoneurone (SETi) to this muscle. 2. At low frequencies of SETi stimulation (1Hz and below) the predominant modulatory effects are increases in the amplitude and relaxation rate of twitch tension. At higher frequencies, where twitches summate but tetanus is incomplete (up to 20 Hz), the reduction of maintained tension becomes considerably more important. 3. Both octopamine application and DUMETi stimulation reduce the amount of catch tension displayed by the extensor muscle when SETi is fired in a variety of different stimulus patterns. The extensor-tibiae muscle is itself 'pattern sensitive' since is shows a 'positive spacing effect' when SETi is stimulated at an average frequency of 1 Hz. 4. It is suggested that a primary function of DUMETi is to change the response of the muscle from one that favours maintenance of posture to one that favours rapid changes in joint position or force, such as might occur during locomotion.

  16. Hexose-6-kinases in germinating honey locust cotyledons: substrate specificity of D-fructo-6-kinase.

    PubMed

    Myers, D; Matheson, N K

    1994-11-01

    Extracts of the cotyledons of germinated honey locust (Gleditsia triacanthos) seeds, which contain galactomannan as a reserve polysaccharide in the endosperm, were fractionated by chromatography and the fractions examined for the presence of a specific manno-6-kinase which could phosphorylate the D-mannose released by hydrolysis of galactomannan. One particulate hexokinase (the major hexose-6-kinase fraction) and two soluble hexokinase fractions (the minor portion), as well as a soluble fructo-6-kinase fraction, were initially separated. From chromatography, electrophoresis and kinetic studies, no evidence for a specific manno-kinase was obtained. This and the level and kinetic behaviour of the particulate hexokinase implicated it as the enzyme catalysing the phosphorylation of released D-mannose. The fructo-kinase activity was further separated into three fractions. Kinetic studies on one of these with native and synthetic substrates indicated that the structural requirements for the monosaccharide substrate were a beta-D-anomeric 2-OH in the furanose ring, a 4-OH trans to the D-5-CH2OH and a -CH2OH substituent on C2 (trans to the 5-CH2OH) which could be modified. The orientation of the hydroxyl on C-3 had only a limited effect.

  17. Phytohormone and assimilate profiles in emasculated flowers of the black locust (Robinia pseudoacacia) during development.

    PubMed

    Sun, Peng; Yuan, Cunquan; Dai, Li; Xi, Yang; Li, Yunfei; Hu, Ruiyang; Sun, Yuhan; Xu, Zhaohe; Li, Yun

    2013-09-01

    Emasculation and bagging of flowers, which are widely used in the controlled pollination of monoclinous plants, may induce premature senescence, flower abscission and low fruit set. To determine the mechanism responsible for these phenomena, levels of abscisic acid (ABA), jasmonic acid (JA), indole-3-acetic acid (IAA), ethylene, soluble sugars, reducing sugars and free amino acids in black locust (Robinia pseudoacacia) flowers subjected to different treatments were quantified at different developmental stages. The phytohormones and assimilates were also quantified in untreated flowers to investigate the presence of discernible patterns. The levels of ethylene and ABA in emasculated and bagged (EB) flowers increased prematurely compared with those of untreated flowers, whereas the content of reducing sugars in EB flowers decreased compared with that of untreated flowers. These results indicated that the premature increase in ethylene and ABA synthesis, and the decrease in reducing sugars content, in EB flowers may cause flower abscission and result in low fruit set, which may be relevant for assimilate applications and future research on the regulation of controlled pollinations with exogenous phytohormones.

  18. Regeneration of axotomized olfactory neurons in young and adult locusts quantified by fasciclin I immunofluorescence.

    PubMed

    Wasser, Hannah; Biller, Alexandra; Antonopoulos, Georgios; Meyer, Heiko; Bicker, Gerd; Stern, Michael

    2017-04-01

    The olfactory pathway of the locust Locusta migratoria is characterized by a multiglomerular innervation of the antennal lobe (AL) by olfactory receptor neurons (ORNs). After crushing the antenna and thereby severing ORN axons, changes in the AL were monitored. First, volume changes were measured at different times post-crush with scanning laser optical tomography in 5th instar nymphs. AL volume decreased significantly to a minimum volume at 4 days post-crush, followed by an increase. Second, anterograde labeling was used to visualize details in the AL and antennal nerve (AN) during de- and regeneration. Within 24 h post-crush (hpc) the ORN fragments distal to the lesion degenerated. After 48 hpc, regenerating fibers grew through the crush site. In the AL, labeled ORN projections disappeared completely and reappeared after a few days. A weak topographic match between ORN origin on the antenna and the position of innervated glomeruli that was present in untreated controls did not reappear after regeneration. Third, the cell surface marker fasciclin I that is expressed in ORNs was used for quantifying purposes. Immunofluorescence was measured in the AL during de- and regeneration in adults and 5th instar nymphs: after a rapid but transient, decrease, it reappeared. Both processes happen faster in 5th instar nymphs than in adults.

  19. A temperature rise reduces trial-to-trial variability of locust auditory neuron responses

    PubMed Central

    Schleimer, Jan-Hendrik; Schreiber, Susanne; Ronacher, Bernhard

    2015-01-01

    The neurophysiology of ectothermic animals, such as insects, is affected by environmental temperature, as their body temperature fluctuates with ambient conditions. Changes in temperature alter properties of neurons and, consequently, have an impact on the processing of information. Nevertheless, nervous system function is often maintained over a broad temperature range, exhibiting a surprising robustness to variations in temperature. A special problem arises for acoustically communicating insects, as in these animals mate recognition and mate localization typically rely on the decoding of fast amplitude modulations in calling and courtship songs. In the auditory periphery, however, temporal resolution is constrained by intrinsic neuronal noise. Such noise predominantly arises from the stochasticity of ion channel gating and potentially impairs the processing of sensory signals. On the basis of intracellular recordings of locust auditory neurons, we show that intrinsic neuronal variability on the level of spikes is reduced with increasing temperature. We use a detailed mathematical model including stochastic ion channel gating to shed light on the underlying biophysical mechanisms in auditory receptor neurons: because of a redistribution of channel-induced current noise toward higher frequencies and specifics of the temperature dependence of the membrane impedance, membrane potential noise is indeed reduced at higher temperatures. This finding holds under generic conditions and physiologically plausible assumptions on the temperature dependence of the channels' kinetics and peak conductances. We demonstrate that the identified mechanism also can explain the experimentally observed reduction of spike timing variability at higher temperatures. PMID:26041833

  20. Respiratory dynamics of discontinuous gas exchange in the tracheal system of the desert locust, Schistocerca gregaria.

    PubMed

    Groenewald, Berlizé; Hetz, Stefan K; Chown, Steven L; Terblanche, John S

    2012-07-01

    Gas exchange dynamics in insects is of fundamental importance to understanding evolved variation in breathing patterns, such as discontinuous gas exchange cycles (DGCs). Most insects do not rely solely on diffusion for the exchange of respiratory gases but may also make use of respiratory movements (active ventilation) to supplement gas exchange at rest. However, their temporal dynamics have not been widely investigated. Here, intratracheal pressure, V(CO2) and body movements of the desert locust Schistocerca gregaria were measured simultaneously during the DGC and revealed several important aspects of gas exchange dynamics. First, S. gregaria employs two different ventilatory strategies, one involving dorso-ventral contractions and the other longitudinal telescoping movements. Second, although a true spiracular closed (C)-phase of the DGC could be identified by means of subatmospheric intratracheal pressure recordings, some CO(2) continued to be released. Third, strong pumping actions do not necessarily lead to CO(2) release and could be used to ensure mixing of gases in the closed tracheal system, or enhance water vapour reabsorption into the haemolymph from fluid-filled tracheole tips by increasing the hydrostatic pressure or forcing fluid into the haemocoel. Finally, this work showed that the C-phase of the DGC can occur at any pressure. These results provide further insights into the mechanistic basis of insect gas exchange.

  1. Dual antibiotherapy of tuberculosis mediated by inhalable locust bean gum microparticles.

    PubMed

    Rodrigues, Susana; Alves, Ana D; Cavaco, Joana S; Pontes, Jorge F; Guerreiro, Filipa; Rosa da Costa, Ana M; Buttini, Francesca; Grenha, Ana

    2017-08-30

    Despite the existence of effective oral therapy, tuberculosis remains a deadly pathology, namely because of bacterial resistance and incompliance with treatments. Establishing alternative therapeutic approaches is urgently needed and inhalable therapy has a great potential in this regard. As pathogenic bacteria are hosted by alveolar macrophages, the co-localisation of antitubercular drugs and pathogens is thus potentiated by this strategy. This work proposes inhalable therapy of pulmonary tuberculosis mediated by a single locust bean gum (LBG) formulation of microparticles associating both isoniazid and rifabutin, complying with requisites of the World Health Organisation of combined therapy. Microparticles were produced by spray-drying, at LBG/INH/RFB mass ratio of 10/1/0.5. The aerodynamic characterisation of microparticles revealed emitted doses of more than 90% and fine particle fraction of 38%, thus indicating the adequacy of the system to reach the respiratory lung area, thus partially the alveolar region. Cytotoxicity results indicate moderate toxicity (cell viability around 60%), with a concentration-dependent effect. Additionally, rat alveolar macrophages evidenced preferential capture of LBG microparticles, possibly due to chemical composition comprising mannose and galactose units that are specifically recognised by macrophage surface receptors. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Chitosan - Locust bean gum interpenetrating polymeric network nanocomposites for delivery of aceclofenac.

    PubMed

    Jana, Sougata; Sen, Kalyan Kumar

    2017-09-01

    In this study, aceclofenac-loaded IPN nanocomposites were developed based on natural polysaccharides namely chitosan (CS) and locust bean gum (LBG) using glutaraldehyde as cross-linker. Infrared spectroscopy analysis confirmed the formation of composite materials and ensured the chemical compatibility between drug and polymers. The effect of component polymers on the drug entrapment efficiency (DEE) and particle size of the composites was examined. Increasing LBG content actually decreased the DEE from 72% to 40% and produced larger particles of 372-485nm dimensions. However, an opposite trend was noted as the concentration of CS was increased. Out of these composites, the maximum drug entrapment efficiency of 78.92% and smallest composites of 318nm-size was obtained at LBG: CS mass ratio of 1:5. However, CS: LBG (1:5) provided the slowest drug release profiles in phosphate buffer solution (pH 6.8) up to 8h. The drug release data corroborated well with the swelling properties of the nanocomposites. The composite systems efficiently suppressed the burst release of drug in acidic medium (pH 1.2). The drug delivery from the nanocomposites occurred via anomalous transport mechanism in vitro. Overall, this novel chitosan- and LBG-based nanocomposites system could minimize the gastrointestinal side effects of the drug by providing medication in a slow sustained fashion. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Digital particle image velocimetry measurements of the downwash distribution of a desert locust Schistocerca gregaria

    PubMed Central

    Bomphrey, Richard J; Taylor, Graham K; Lawson, Nicholas J; Thomas, Adrian L.R

    2005-01-01

    Actuator disc models of insect flight are concerned solely with the rate of momentum transfer to the air that passes through the disc. These simple models assume that an even pressure is applied across the disc, resulting in a uniform downwash distribution. However, a correction factor, k, is often included to correct for the difference in efficiency between the assumed even downwash distribution, and the real downwash distribution. In the absence of any empirical measurements of the downwash distribution behind a real insect, the values of k used in the literature have been necessarily speculative. Direct measurement of this efficiency factor is now possible, and could be used to compare the relative efficiencies of insect flight across the Class. Here, we use Digital Particle Image Velocimetry to measure the instantaneous downwash distribution, mid-downstroke, of a tethered desert locust (Schistocerca gregaria). By integrating the downwash distribution, we are thereby able to provide the first direct empirical measurement of k for an insect. The measured value of k=1.12 corresponds reasonably well with that predicted by previous theoretical studies. PMID:16849240

  4. Central generation of grooming motor patterns and interlimb coordination in locusts.

    PubMed

    Berkowitz, A; Laurent, G

    1996-12-15

    Coordinated bursts of leg motoneuron activity were evoked in locusts with deefferented legs by tactile stimulation of sites that evoke grooming behavior. This suggests that insect thoracic ganglia contain central pattern generators for directed leg movements. Motoneuron recordings were made from metathoracic and mesothoracic nerves, after eliminating all leg motor innervation, as well as all input from the brain, subesophageal ganglion, and prothoracic ganglion. Strong, brief trochanteral levator motoneuron bursts occurred, together with silence of the slow and fast trochanteral depressor motoneurons and activation of the common inhibitor motoneuron. The metathoracic slow tibial extensor motoneuron was active in a pattern distinct from its activity during walking or during rhythms evoked by the muscarinic agonist pilocarpine. Preparations in which the metathoracic ganglion was isolated from all other ganglia could still produce fictive motor patterns in response to tactile stimulation of metathoracic locations. Bursts of trochanteral levator and depressor motoneurons were clearly coordinated between the left and right metathoracic hemiganglia and also between the mesothoracic and the ipsilateral metathoracic ganglia. These data provide clear evidence for centrally generated interlimb coordination in an insect.

  5. A test of the oxidative damage hypothesis for discontinuous gas exchange in the locust Locusta migratoria.

    PubMed

    Matthews, Philip G D; Snelling, Edward P; Seymour, Roger S; White, Craig R

    2012-08-23

    The discontinuous gas exchange cycle (DGC) is a breathing pattern displayed by many insects, characterized by periodic breath-holding and intermittently low tracheal O(2) levels. It has been hypothesized that the adaptive value of DGCs is to reduce oxidative damage, with low tracheal O(2) partial pressures (PO(2) ≈ 2-5 kPa) occurring to reduce the production of oxygen free radicals. If this is so, insects displaying DGCs should continue to actively defend a low tracheal PO(2) even when breathing higher than atmospheric levels of oxygen (hyperoxia). This behaviour has been observed in moth pupae exposed to ambient PO(2) up to 50 kPa. To test this observation in adult insects, we implanted fibre-optic oxygen optodes within the tracheal systems of adult migratory locusts Locusta migratoria exposed to normoxia, hypoxia and hyperoxia. In normoxic and hypoxic atmospheres, the minimum tracheal PO(2) that occurred during DGCs varied between 3.4 and 1.2 kPa. In hyperoxia up to 40.5 kPa, the minimum tracheal PO(2) achieved during a DGC exceeded 30 kPa, increasing with ambient levels. These results are consistent with a respiratory control mechanism that functions to satisfy O(2) requirements by maintaining PO(2) above a critical level, not defend against high levels of O(2).

  6. Oxygen partial pressure effects on metabolic rate and behavior of tethered flying locusts.

    PubMed

    Rascón, Brenda; Harrison, Jon F

    2005-11-01

    Resting insects are extremely tolerant of hypoxia. However, oxygen requirements increase dramatically during flight. Does the critical atmospheric P (O)(2) (P(c)) increase strongly during flight, or does increased tracheal conductance allow even flying insects to possess large safety margins for oxygen delivery? We tested the effect of P(O)(2) on resting and flying CO(2) emission, as well as on flight behavior and vertical force production in flying locusts, Schistocerca americana. The P(c) for CO(2) emission of resting animals was less than 1 kPa, similar to prior studies. The P(c) for flight bout duration was between 10 and 21 kPa, the P(c) for vertical force production was between 3 and 5 kPa, and the P(c) for CO(2) emission was between 10 and 21 kPa. Our study suggests that the P(c) for steady-state oxygen consumption is between 10 and 21 kPa (much higher than for resting animals), and that tracheal oxygen stores allowed brief flights in 5 and 10 kPa P(O)(2) atmospheres to occur. Thus, P(c) values strongly increased during flight, consistent with the hypothesis that the excess oxygen delivery capacity observed in resting insects is substantially reduced during flight.

  7. Water adsorption isotherms of carboxymethyl cellulose, guar, locust bean, tragacanth and xanthan gums.

    PubMed

    Torres, María D; Moreira, Ramón; Chenlo, Francisco; Vázquez, María J

    2012-06-20

    Water adsorption isotherms of carboxymethyl cellulose (CMC), guar gum (GG), locust bean gum (LBG), tragacanth gum (TG) and xanthan gum (XG) were determined at different temperatures (20, 35, 50, and 65°C) using a gravimetric method. Several saturated salt solutions were selected to obtain different water activities in the range from 0.09 to 0.91. Water adsorption isotherms of tested hydrocolloids were classified like type II isotherms. In all cases, equilibrium moisture content decreased with increasing temperature at each water activity value. Three-parameter Guggenheim-Anderson-de Boer (GAB) model was employed to fit the experimental data in the water activity range and statistical analysis indicated that this model gave satisfactory results. CMC and GG were the most and the least hygroscopic gums, respectively. Sorption heats decreased with increasing moisture content. Monolayer moisture content evaluated with GAB model was consistent with equilibrium conditions of maximum stability calculated from thermodynamic analysis of net integral entropy. Values of equilibrium relative humidity at 20°C are proposed to storage adequately the tested gums.

  8. Soil moisture assessments for brown locust Locustana pardalina breeding potential using synthetic aperture radar

    NASA Astrophysics Data System (ADS)

    Crooks, William T. S.; Cheke, Robert A.

    2014-01-01

    Synthetic aperture radar (SAR) imagery was collected over a brown locust Locustana pardalina outbreak area to estimate soil moisture relevant to egg development. ERS-2/RadarSat overpasses and field studies enabled parameterization of surface roughness, volumetric soil moisture, soil texture, and vegetation cover. Data were analyzed both when the target area was assessed as nonvegetated and when treated as vegetated. For the former, using the integral equation model (IEM) and soil surface data combined with the sensitivity of the IEM to changes in surface roughness introduced an error of ˜±0.06 cm3 cm-3 in volumetric soil moisture. Comparison of the IEM modeling results with backscatter responses from the ERS-2/RadarSat imagery revealed errors as high as ±0.14 cm3 cm-3, mostly due to IEM calibration problems and the impact of vegetation. Two modified versions of the water cloud model (WCM) were parameterized, one based on measurements of vegetation moisture and the other on vegetation biomass. A sensitivity analysis of the resulting model revealed a positive relationship between increases in both vegetation biomass and vegetation moisture and the backscatter responses from the ERS-2 and RadarSat sensors. The WCM was able to explain up to 80% of the variability found when the IEM was used alone.

  9. Stress-induced thermotolerance of ventilatory motor pattern generation in the locust, Locusta migratoria.

    PubMed

    Newman, Amy E M; Foerster, Melody; Shoemaker, Kelly L; Robertson, R Meldrum

    2003-11-01

    Ventilation is a crucial motor activity that provides organisms with an adequate circulation of respiratory gases. For animals that exist in harsh environments, an important goal is to protect ventilation under extreme conditions. Heat shock, anoxia, and cold shock are environmental stresses that have previously been shown to trigger protective responses. We used the locust to examine stress-induced thermotolerance by monitoring the ability of the central nervous system to generate ventilatory motor patterns during a subsequent heat exposure. Preparations from pre-stressed animals had an increased incidence of motor pattern recovery following heat-induced failure, however, prior stress did not alter the characteristics of the ventilatory motor pattern. During constant heat exposure at sub-lethal temperatures, we observed a protective effect of heat shock pre-treatment. Serotonin application had similar effects on motor patterns when compared to prior heat shock. These studies are consistent with previous studies that indicate prior exposure to extreme temperatures and hypoxia can protect neural operation against high temperature stress. They further suggest that the protective mechanism is a time-dependent process best revealed during prolonged exposure to extreme temperatures and is mediated by a neuromodulator such as serotonin.

  10. Effects of locust bean gum on the structural and rheological properties of resistant corn starch.

    PubMed

    Hussain, Raza; Singh, Ajaypal; Vatankhah, Hamed; Ramaswamy, Hosahalli S

    2017-03-01

    In this study, interactions between resistant corn starch (RS) (5% w/w) and locust bean gum (LBG) (0, 0.125, 0.25, 0.50 and 1.0% w/v) on the viscoelastic, pasting and morphological characteristics of aqueous dispersions were evaluated. Results showed that the storage modulus (G'), loss modulus (G''), and apparent viscosity values of starch/gum (RS/LBG) mixtures were enhanced with the addition of LBG, and the rheograms demonstrated a biphasic behavior. RS/LBG samples were predominantly either solid like (G' > G'') or viscous (G'' > G'), depending on the added concentration level of LBG. Gum addition also caused higher peak viscosity, breakdown and total set back of RS/LBG mixtures. A strong correlation between rheological and structural properties was found. Confocal laser scanning microscopy (CLSM) images confirmed the transition of starch particles from a scattered angular shape to clustered structures cross-linked by dense aggregate junction zones justifying the observed changes in rheological properties.

  11. Fast Odor Learning Improves Reliability of Odor Responses in the Locust Antennal Lobe

    PubMed Central

    Bazhenov, Maxim; Stopfer, Mark; Sejnowski, Terrence J.; Laurent, Gilles

    2010-01-01

    Summary Recordings in the locust antennal lobe (AL) reveal activity-dependent, stimulus-specific changes in projection neuron (PN) and local neuron response patterns over repeated odor trials. During the first few trials, PN response intensity decreases, while spike time precision increases, and coherent oscillations, absent at first, quickly emerge. We examined this “fast odor learning” with a realistic computational model of the AL. Activity-dependent facilitation of AL inhibitory synapses was sufficient to simulate physiological recordings of fast learning. In addition, in experiments with noisy inputs, a network including synaptic facilitation of both inhibition and excitation responded with reliable spatiotemporal patterns from trial to trial despite the noise. A network lacking fast plasticity, however, responded with patterns that varied across trials, reflecting the input variability. Thus, our study suggests that fast olfactory learning results from stimulus-specific, activity-dependent synaptic facilitation and may improve the signal-to-noise ratio for repeatedly encountered odor stimuli. PMID:15882647

  12. The Giant Magnetocaloric Effect

    NASA Astrophysics Data System (ADS)

    Pecharsky, Vitalij K.

    1998-03-01

    Since the discovery of the magnetocaloric effect in pure iron by E.Warburg in 1881, it has been measured experimentally on many magnetic metals and compounds. The majority of the materials studied order magnetically undergoing a second order phase transformation. The magnetocaloric effect, typically peaking near the Curie or the Néel temperature, generally ranges from 0.5 to 2 K (in terms of adiabatic temperature change) or at 1 to 4 J/kg K (in terms of isothermal magnetic entropy change) per 1 T magnetic field change. The giant magnetocaloric effect recently discovered in Gd_5(Si_xGe_1-x)4 alloys, where x <= 0.5, is associated with a first order magnetic phase transition and it reaches values of 3 to 4 K and 6 to 10 J/kg K per 1 T field change, respectively. The refrigerant capacity, which is the measure of how much heat can be transferred from a cold to a hot reservoir in one ideal thermodynamic cycle, is larger than that of the best second order phase transition materials by 25 to 100%. When the Gd_5(Si_xGe_1-x)4 alloys are compared with other known materials, which show first order magnetic phase transition, such as Dy, Ho, Er, HoCo_2, NdMn_2Si_2, Fe_0.49Rh_0.51, and (Hf_0.83Ta_0.17)Fe_2+x, only Fe_0.49Rh_0.51 has comparable magnetocaloric properties. However, the first order magnetic phase transition in Fe_0.49Rh_0.51 is irreversible, and the magnetocaloric effect disappears after one magnetizing/demagnetizing cycle. A study of the crystal structure, thermodynamics, and magnetism of the Gd_5(Si_xGe_1-x)4 alloys, where 0 <= x <= 1 allowed us to obtain a qualitative understanding of the basic relations between the composition, the crystal structure, and the change in thermodynamics and magnetocaloric properties, which occur in the Gd_5(Si_xGe_1-x)4 system, and which brings about the giant magnetocaloric effect when x <= 0.5.

  13. Assessment and validation of a suite of reverse transcription-quantitative PCR reference genes for analyses of density-dependent behavioural plasticity in the Australian plague locust

    PubMed Central

    2011-01-01

    Background The Australian plague locust, Chortoicetes terminifera, is among the most promising species to unravel the suites of genes underling the density-dependent shift from shy and cryptic solitarious behaviour to the highly active and aggregating gregarious behaviour that is characteristic of locusts. This is because it lacks many of the major phenotypic changes in colour and morphology that accompany phase change in other locust species. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is the most sensitive method available for determining changes in gene expression. However, to accurately monitor the expression of target genes, it is essential to select an appropriate normalization strategy to control for non-specific variation between samples. Here we identify eight potential reference genes and examine their expression stability at different rearing density treatments in neural tissue of the Australian plague locust. Results Taking advantage of the new orthologous DNA sequences available in locusts, we developed primers for genes encoding 18SrRNA, ribosomal protein L32 (RpL32), armadillo (Arm), actin 5C (Actin), succinate dehydrogenase (SDHa), glyceraldehyde-3P-dehydrogenase (GAPDH), elongation factor 1 alpha (EF1a) and annexin IX (AnnIX). The relative transcription levels of these eight genes were then analyzed in three treatment groups differing in rearing density (isolated, short- and long-term crowded), each made up of five pools of four neural tissue samples from 5th instar nymphs. SDHa and GAPDH, which are both involved in metabolic pathways, were identified as the least stable in expression levels, challenging their usefulness in normalization. Based on calculations performed with the geNorm and NormFinder programs, the best combination of two genes for normalization of gene expression data following crowding in the Australian plague locust was EF1a and Arm. We applied their use to studying a target gene that encodes a Ca2

  14. The role of egg pod foam and rearing conditions of the phase state of the Asian migratory locust Locusta migratoria migratoria (Orthoptera, Acrididae).

    PubMed

    Ben Hamouda, Amel; Ammar, Mohamed; Ben Hamouda, Mohamed Habib; Bouain, Abderrahmen

    2009-07-01

    Coloration phase state, morphometrical ratios and the numbers of mature oocytes of Locusta migratoria migratoria were examined in a series of experiments to determine the means by which phase characteristics are passed to the next generation. Washing with distilled water of eggs from egg pods laid by gregarious crowd-reared females resulted in solitarization of the hatchlings after their isolation, indicating that a factor present in eggs encapsulated in foam is causal to gregarization. Such locusts showed a significant shift towards the typical solitarious body coloration, morphometry and number of mature oocytes as compared to locusts resulting from unwashed eggs. Gregarious coloration, morphometrical ratios and oocyte numbers could be partially restored when hatchlings from washed eggs were regrouped. When gregarious locusts were reared in isolation, they showed a solitary body color, whereas, morphometry and oocyte numbers were not affected by isolation.

  15. Giant necrotic pituitary apoplexy.

    PubMed

    Fanous, Andrew A; Quigley, Edward P; Chin, Steven S; Couldwell, William T

    2013-10-01

    Apoplexy of the pituitary gland is a rare complication of pituitary adenomas, involving hemorrhage with or without necrosis within the tumor. This condition may be either asymptomatic or may present with severe headache, visual impairment, ophthalmoplegia, and pituitary failure. Transsphenoidal surgery is the treatment of choice, and early intervention is usually required to ensure reversal of visual impairment. Reports of pituitary apoplectic lesions exceeding 60.0mm in diameter are very rare. A 39-year-old man with long-standing history of nasal congestion, decreased libido and infertility presented with a sudden onset of severe headache and diplopia. MRI of the head demonstrated a massive skull base lesion of 70.0 × 60.0 × 25.0mm, compatible with a giant pituitary macroadenoma. The lesion failed to enhance after administration of a contrast agent, suggesting complete necrotic apoplexy. Urgent surgical decompression was performed, and the lesion was resected via a transnasal transsphenoidal approach. Pathological analysis revealed evidence of necrotic pituitary apoplexy. At the 2 month follow-up, the patient had near-complete to complete resolution of his visual impairment. To the authors' knowledge, this report is unique as the patient demonstrated complete necrotic apoplexy and it underlines the diagnostic dilemma in such a case. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Recurrent renal giant leiomyosarcoma

    PubMed Central

    Öziş, Salih Erpulat; Gülpınar, Kamil; Şahlı, Zafer; Konak, Baha Burak; Keskin, Mete; Özdemir, Süleyman; Ataoğlu, Ömür

    2016-01-01

    Primary renal leiomyosarcomas are rare, aggressive tumors. They constitute 1–2% of adult malignant renal tumors. Although leiomyosarcomas are the most common histological type (50–60%) of renal sarcomas, information on renal leiomyosarcoma is limited. Local or systemic recurrences are common. The radiological appearance of renal leiomyosarcomas is not specific, therefore renal leiomyosarcoma cannot be distinguished from renal cell carcinoma by imaging methods in all patients. A 74-year-old female patient presented to our clinic complaining of a palpable mass on the right side of her abdomen in November 2012. The abdominal magnetic resonance imaging revealed a mass, 25 × 24 × 23 cm in size. Her past medical history revealed that she has undergone right radical nephrectomy in 2007, due to a 11 × 12 × 13 cm renal mass that was then reported as renal cell carcinoma on abdominal magnetic resonance imaging, but the pathological diagnosis was low-grade renal leiomyosarcoma. The most recent follow-up of the patient was in 2011, with no signs of local recurrence or distant metastases within this four-year period. The patient underwent laparotomy on November 2012, and a 35 cm retroperitoneal mass was excised. The pathological examination of the mass was reported as high-grade leiomyosarcoma. The formation of this giant retroperitoneal mass in 1 year can be explained by the transformation of the lesion’s pathology from low-grade to a high-grade tumor. PMID:27436926

  17. Giant cell arteritis.

    PubMed

    Ninan, Jem; Lester, Susan; Hill, Catherine

    2016-02-01

    Giant cell arteritis (GCA) is the most common vasculitis of the elderly. The diagnosis can be challenging at times because of the limitation of the American Rheumatology Association (ARA) classification criteria and the significant proportion of biopsy-negative patients with GCA. We discuss the role of advanced imaging techniques, including positron emission tomography (PET) scanning, in establishing diagnosis and improved histopathology techniques to improve the sensitivity of temporal artery biopsy. There have been significant advances in the understanding of the pathogenesis of GCA, particularly the role of cytokine pathways such as the interleukins, IL-6-IL-17 axis, and the IL-12-interferon-γ axis and their implication for new therapies. We highlight that glucocorticoids remain the primary treatment for GCA, but recognize the risk of steroid-induced side effects. A number of pharmacotherapies to enable glucocorticoid dose reduction and prevent relapse have been studied. Early diagnosis and fast-track pathways have improved outcomes by encouraging adherence to evidence-based practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. [Changes of Soil Organic Carbon and Its Influencing Factors of Apple Orchards and Black Locusts in the Small Watershed of Loess Plateau, China].

    PubMed

    Li, Ru-jian; Wang, Rui; Li, Na-na; Jiang, Ji-shao; Zhang, Yan-jun; Wang, Zhi-qi; Liu, Qing-fang; Wu, De-feng; Guo, Sheng-li

    2015-07-01

    Orchard and black locust are two typical plants for comprehensive control in the small watershed of land uses in Loess area. The analysis of soil carbon sequestration function changes of growing two plants is important to gain a deep understanding of soil carbon cycle process and its influencing factors of terrestrial ecosystems under the condition of small watershed comprehensive control. The experiment was conducted in the Changwu State Key Agro-Ecological Station, Shanxi, China. SOC, TN, fine root biomass and litter amount were determined at different age apple orchards and black locusts on the slope land of Wangdonggou watershed to study the variation characteristics of soil organic carbon and its influencing factors under two measurements. The results showed that: (1) SOC and TN contents in apple orchards significantly decreased with the increased age, whereas those in black locust showed an increased tendency with the age increased. Compared with the adjacent cropland,the SOC and TN contents in year 3, year 8, year 12 and year 18 apple orchards were decreased 3. 26%, 10. 54%, 18. 08%, 22. 55% and - 8. 08%, - 0. 48%, 4. 97%, 16. 91%, respectively. However,SOC and TN contents increased 5. 31%, 32. 36%, 44. 13% and 2. 49%, 15. 75%, 24. 22%, in year 12, year 18 and year 25 black locusts, respectively. (2) The fine root biomass in year 3, year 8, year 12, and year 18 apple orchards were about 25. 97% 66. 23%, 85. 71% and 96. 10% of the adjacent cropland, respectively; and the litter amounts were all 0 g . m-2. However, compared with adjacent cropland, The fine root biomass in year 12, year 18 and year 25 black locusts were increased 23. 53%, 79. 41%, 157. 35%, respectively; and the litter input rates were 194, 298 , 433 g . (m2 . a) -1, respectively. (3) The difference of organic matter input was the major factor which drove the variability of soil carbon sequestration function of apple orchard and black locust ecosystems.

  19. A unique advantage for giant eyes in giant squid.

    PubMed

    Nilsson, Dan-Eric; Warrant, Eric J; Johnsen, Sönke; Hanlon, Roger; Shashar, Nadav

    2012-04-24

    Giant and colossal deep-sea squid (Architeuthis and Mesonychoteuthis) have the largest eyes in the animal kingdom [1, 2], but there is no explanation for why they would need eyes that are nearly three times the diameter of those of any other extant animal. Here we develop a theory for visual detection in pelagic habitats, which predicts that such giant eyes are unlikely to evolve for detecting mates or prey at long distance but are instead uniquely suited for detecting very large predators, such as sperm whales. We also provide photographic documentation of an eyeball of about 27 cm with a 9 cm pupil in a giant squid, and we predict that, below 600 m depth, it would allow detection of sperm whales at distances exceeding 120 m. With this long range of vision, giant squid get an early warning of approaching sperm whales. Because the sonar range of sperm whales exceeds 120 m [3-5], we hypothesize that a well-prepared and powerful evasive response to hunting sperm whales may have driven the evolution of huge dimensions in both eyes and bodies of giant and colossal squid. Our theory also provides insights into the vision of Mesozoic ichthyosaurs with unusually large eyes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Clump Giants in the Hyades

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard F. (Technical Monitor); Brickhouse, Nancy

    2003-01-01

    The project is entitled 'Clump Giants in the Hyades.' This observation of one of the late-type Hyades giants (Gamma Tau) has implications for understanding the formation of late-type stellar coronae as a function of the evolutionary state of the star. The Hyades giants are interesting because they are all clump giants in the Helium burning phase, similar to the cool primary of Capella. The Hyades giants show significantly more magnetic activity than expected from their state of evolution (and slowed-down rotation). Thus these systems provide an important clue to dynamo action. The data were obtained by the satellite on 13 March 2001 for a total RGS exposure of 58220 seconds. These data were delivered to the PI on 7 August 2001. The data could not be reprocessed until SAS Version 5.3.3 which became available 7 June 2002. Although the guidelines for assessing background rates suggested that half the data were contaminated, it does not appear that the spectral region of the RGS was adversely affected by unusually high background. The spectra show strong lines of Fe XVII and XVIII, O VII and VIII, Ne IX and X, along with numerous weaker lines. The emission measure distribution is highly reminiscent of Capella; if anything, the emission measure distribution is steeper at 6 million K than for Capella. Gamma Tau is the second brightest of the Hyades clump giants. Pallavicini et al. have shown that the luminosity of the brightest Hyades giant (Theta Tau) is remarkably similar to its luminosity as measured by Einstein. Short-term variability is also modest. We are addressing the variability issue now for Gamma Tau. Initial results were reported at the 2003 Seattle AAS meeting. A paper is in preparation for submission to the Astrophysical Journal.

  1. Formation of the giant planets

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2006-01-01

    The observed properties of giant planets, models of their evolution and observations of protoplanetary disks provide constraints on the formation of gas giant planets. The four largest planets in our Solar System contain considerable quantities of hydrogen and helium, which could not have condensed into solid planetesimals within the protoplanetary disk. All three (transiting) extrasolar giant planets with well determined masses and radii also must contain substantial amounts of these light gases. Jupiter and Saturn are mostly hydrogen and helium, but have larger abundances of heavier elements than does the Sun. Neptune and Uranus are primarily composed of heavier elements. HD 149026 b, which is slightly more massive than is Saturn, appears to have comparable quantities of light gases and heavy elements. HD 209458 b and TrES-1 are primarily hydrogen and helium, but may contain supersolar abundances of heavy elements. Spacecraft flybys and observations of satellite orbits provide estimates of the gravitational moments of the giant planets in our Solar System, which in turn provide information on the internal distribution of matter within Jupiter, Saturn, Uranus and Neptune. Atmospheric thermal structure and heat flow measurements constrain the interior temperatures of planets. Internal processes may cause giant planets to become more compositionally differentiated or alternatively more homogeneous; high-pressure laboratory .experiments provide data useful for modeling these processes. The preponderance of evidence supports the core nucleated gas accretion model. According to this model, giant planets begin their growth by the accumulation of small solid bodies, as do terrestrial planets. However, unlike terrestrial planets, the growing giant planet cores become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. The primary questions regarding the core nucleated growth model is under what conditions

  2. Clump Giants in the Hyades

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard F. (Technical Monitor); Brickhouse, Nancy

    2003-01-01

    The project is entitled 'Clump Giants in the Hyades.' This observation of one of the late-type Hyades giants (Gamma Tau) has implications for understanding the formation of late-type stellar coronae as a function of the evolutionary state of the star. The Hyades giants are interesting because they are all clump giants in the Helium burning phase, similar to the cool primary of Capella. The Hyades giants show significantly more magnetic activity than expected from their state of evolution (and slowed-down rotation). Thus these systems provide an important clue to dynamo action. The data were obtained by the satellite on 13 March 2001 for a total RGS exposure of 58220 seconds. These data were delivered to the PI on 7 August 2001. The data could not be reprocessed until SAS Version 5.3.3 which became available 7 June 2002. Although the guidelines for assessing background rates suggested that half the data were contaminated, it does not appear that the spectral region of the RGS was adversely affected by unusually high background. The spectra show strong lines of Fe XVII and XVIII, O VII and VIII, Ne IX and X, along with numerous weaker lines. The emission measure distribution is highly reminiscent of Capella; if anything, the emission measure distribution is steeper at 6 million K than for Capella. Gamma Tau is the second brightest of the Hyades clump giants. Pallavicini et al. have shown that the luminosity of the brightest Hyades giant (Theta Tau) is remarkably similar to its luminosity as measured by Einstein. Short-term variability is also modest. We are addressing the variability issue now for Gamma Tau. Initial results were reported at the 2003 Seattle AAS meeting. A paper is in preparation for submission to the Astrophysical Journal.

  3. Formation of the giant planets

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2006-01-01

    The observed properties of giant planets, models of their evolution and observations of protoplanetary disks provide constraints on the formation of gas giant planets. The four largest planets in our Solar System contain considerable quantities of hydrogen and helium, which could not have condensed into solid planetesimals within the protoplanetary disk. All three (transiting) extrasolar giant planets with well determined masses and radii also must contain substantial amounts of these light gases. Jupiter and Saturn are mostly hydrogen and helium, but have larger abundances of heavier elements than does the Sun. Neptune and Uranus are primarily composed of heavier elements. HD 149026 b, which is slightly more massive than is Saturn, appears to have comparable quantities of light gases and heavy elements. HD 209458 b and TrES-1 are primarily hydrogen and helium, but may contain supersolar abundances of heavy elements. Spacecraft flybys and observations of satellite orbits provide estimates of the gravitational moments of the giant planets in our Solar System, which in turn provide information on the internal distribution of matter within Jupiter, Saturn, Uranus and Neptune. Atmospheric thermal structure and heat flow measurements constrain the interior temperatures of planets. Internal processes may cause giant planets to become more compositionally differentiated or alternatively more homogeneous; high-pressure laboratory .experiments provide data useful for modeling these processes. The preponderance of evidence supports the core nucleated gas accretion model. According to this model, giant planets begin their growth by the accumulation of small solid bodies, as do terrestrial planets. However, unlike terrestrial planets, the growing giant planet cores become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. The primary questions regarding the core nucleated growth model is under what conditions

  4. The contribution of the genomes of a termite and a locust to our understanding of insect neuropeptides and neurohormones

    PubMed Central

    Veenstra, Jan A.

    2014-01-01

    The genomes of the migratory locust Locusta migratoria and the termite Zootermopsis nevadensis were mined for the presence of genes encoding neuropeptides, neurohormones, and their G-protein coupled receptors (GPCRs). Both species have retained a larger number of neuropeptide and neuropeptide GPCRs than the better known holometabolous insect species, while other genes that in holometabolous species appear to have a single transcript produce two different precursors in the locust, the termite or both. Thus, the recently discovered CNMa neuropeptide gene has two transcripts predicted to produce two structurally different CNMa peptides in the termite, while the locust produces two different myosuppressin peptides in the same fashion. Both these species also have a calcitonin gene, which is different from the gene encoding the calcitonin-like insect diuretic hormone. This gene produces two types of calcitonins, calcitonins A and B. It is also present in Lepidoptera and Coleoptera and some Diptera, but absent from mosquitoes and Drosophila. However, in holometabolous insect species, only the B transcript is produced. Their putative receptors were also identified. In contrast, Locusta has a highly unusual gene that codes for a salivation stimulatory peptide. The Locusta genes for neuroparsin and vasopressin are particularly interesting. The neuroparsin gene produces five different transcripts, of which only one codes for the neurohormone identified from the corpora cardiaca. The other four transcripts code for neuroparsin-like proteins, which lack four amino acid residues, and that for that reason we called neoneuroparsins. The number of transcripts for the neoneuroparsins is about 200 times larger than the number of neuroparsin transcripts. The first exon and the putative promoter of the vasopressin genes, of which there are about seven copies in the genome, is very well-conserved, but the remainder of these genes is not. The relevance of these findings is discussed

  5. Neural Control of Gas Exchange Patterns in Insects: Locust Density-Dependent Phases as a Test Case

    PubMed Central

    Berman, Tali S.; Ayali, Amir; Gefen, Eran

    2013-01-01

    The adaptive significance of discontinuous gas exchange cycles (DGC) in insects is contentious. Based on observations of DGC occurrence in insects of typically large brain size and often socially-complex life history, and spontaneous DGC in decapitated insects, the neural hypothesis for the evolution of DGC was recently proposed. It posits that DGC is a non-adaptive consequence of adaptive down-regulation of brain activity at rest, reverting ventilatory control to pattern-generating circuits in the thoracic ganglia. In line with the predictions of this new hypothesis, we expected a higher likelihood of DGC in the gregarious phase of the desert locust (Schistocerca gregaria, Orthoptera), which is characterized by a larger brain size and increased sensory sensitivity compared with the solitary phase. Furthermore, surgical severing of the neural connections between head and thoracic ganglia was expected to increase DGC prevalence in both phases, and to eliminate phase-dependent variation in gas exchange patterns. Using flow-through respirometry, we measured metabolic rates and gas exchange patterns in locusts at 30°C. In contrast to the predictions of the neural hypothesis, we found no phase-dependent differences in DGC expression. Likewise, surgically severing the descending regulation of thoracic ventilatory control did not increase DGC prevalence in either phase. Moreover, connective-cut solitary locusts abandoned DGC altogether, and employed a typical continuous gas exchange pattern despite maintaining metabolic rate levels of controls. These results are not consistent with the predictions of the neural hypothesis for the evolution of DGC in insects, and instead suggest neural plasticity of ventilatory control. PMID:23555850

  6. K⁺ absorption by locust gut and inhibition of ileal K⁺ and water transport by FGLamide allatostatins.

    PubMed

    Robertson, Lisa; Donini, Andrew; Lange, Angela B

    2014-09-15

    The scanning ion-selective electrode technique (SIET) was utilized for the first time in Locusta migratoria to characterize K(+) transport along the digestive tract and to determine the effect of two locust FGLamide allatostatins (FGLa/ASTs) on K(+) transport: a previously sequenced FGLa/AST from Schistocerca gregaria (Scg-AST-6; ARPYSFGL-NH2) and a newly sequenced FGLa/AST from L. migratoria (Locmi-FGLa/AST-2; LPVYNFGL-NH2). Regional differences in K(+) fluxes along the gut were evident, where K(+) efflux in vitro (or absorption into the hemolymph in vivo) was greatest at the anterior ileum, and lowest at the colon. Ileal K(+) efflux was inhibited by both Scg-AST-6 and Locmi-FGLa/AST-2, with maximal inhibition at 10(-10) and 10(-11) mol l(-1), respectively. Both FGLa/ASTs also inhibited cAMP-stimulated K(+) efflux from the ileum. Locmi-FGLa/AST-2 also inhibited efflux of water across the ileum. Locusts are terrestrial insects living in dry climates, risking desiccation and making water conservation a necessity. The results suggest that FGLa/ASTs may be acting as diuretics by increasing K(+) excretion and therefore increasing water excretion. Thus it is likely that FGLa/ASTs are involved in the control of hemolymph water and ion levels during feeding and digestion, to help the locust deal with the excess K(+) load (and subsequently fluid) when the meal is processed. © 2014. Published by The Company of Biologists Ltd.

  7. Open questions about giant viruses.

    PubMed

    Claverie, Jean-Michel; Abergel, Chantal

    2013-01-01

    The recent discovery of giant viruses exhibiting double-stranded DNA genomes larger than a million base pairs, encoding more than a thousand proteins and packed in near micron-sized icosahedral particles, opened a new and unexpected chapter in virology. As of today, these giant viruses and their closest relatives of lesser dimensions infect unicellular eukaryotes found in aquatic environments, but belonging to a wide diversity of early branching phyla. This broad phylogenetic distribution of hosts is consistent with the hypothesis that giant viruses originated prior to the radiation of the eukaryotic domain and/or might have been involved in the partition of nuclear versus cytoplasmic functions in ancestral cells. The distinctive features of the known giant viruses, in particular the recurrent presence of components of the translation apparatus in their proteome, raise a number of fundamental questions about their origin, their mode of evolution, and the relationship they may entertain with other dsDNA viruses, the genome size of which exhibits the widest distribution among all biological entities, from less than 5 kb to more than 1.25 Mb (a ratio of 1:250). At a more conceptual level, the convergence between the discovery of increasingly reduced parasitic cellular organisms and that of giant viruses exhibiting a widening array of cellular-like functions may ultimately abolish the historical discontinuity between the viral and the cellular world. 2013 Elsevier Inc. All rights reserved

  8. Gravitational scattering by giant planets

    NASA Astrophysics Data System (ADS)

    Laakso, T.; Rantala, J.; Kaasalainen, M.

    2006-09-01

    We seek to characterize giant-planet systems by their gravitational scattering properties. We do this to a given system by integrating it numerically along with a large number of hypothetical small bodies that are initially in eccentric habitable zone (HZ)-crossing orbits. Our analysis produces a single number, the escape rate, which represents the rate at which the small-body flux is perturbed away by the giant planets into orbits that no longer pose a threat to terrestrial planets inside the HZ. Obtaining the escape rate this way is similar to computing the largest Liapunov exponent as the exponential rate of divergence of two nearby orbits. For a terrestrial planet inside the HZ, the escape rate value quantifies the "protective" effect that the studied giant-planet system offers. Therefore, escape rates could provide information on whether certain giant-planet configurations produce a more desirable environment for life than the others. We present some computed escape rates on selected planetary systems, focusing on effects of varying the masses and semi-major axes of the giant planets. In the case of our Solar System we find rather surprisingly that Jupiter, in its current orbit, may provide a minimal amount of protection to the Earth.

  9. Giant Magellan Telescope: overview

    NASA Astrophysics Data System (ADS)

    Johns, Matt; McCarthy, Patrick; Raybould, Keith; Bouchez, Antonin; Farahani, Arash; Filgueira, Jose; Jacoby, George; Shectman, Steve; Sheehan, Michael

    2012-09-01

    The Giant Magellan Telescope (GMT) is a 25-meter optical/infrared extremely large telescope that is being built by an international consortium of universities and research institutions. It will be located at the Las Campanas Observatory, Chile. The GMT primary mirror consists of seven 8.4-m borosilicate honeycomb mirror segments made at the Steward Observatory Mirror Lab (SOML). Six identical off-axis segments and one on-axis segment are arranged on a single nearly-paraboloidal parent surface having an overall focal ratio of f/0.7. The fabrication, testing and verification procedures required to produce the closely-matched off-axis mirror segments were developed during the production of the first mirror. Production of the second and third off-axis segments is underway. GMT incorporates a seven-segment Gregorian adaptive secondary to implement three modes of adaptive-optics operation: natural-guide star AO, laser-tomography AO, and ground-layer AO. A wide-field corrector/ADC is available for use in seeing-limited mode over a 20-arcmin diameter field of view. Up to seven instruments can be mounted simultaneously on the telescope in a large Gregorian Instrument Rotator. Conceptual design studies were completed for six AO and seeing-limited instruments, plus a multi-object fiber feed, and a roadmap for phased deployment of the GMT instrument suite is being developed. The partner institutions have made firm commitments for approximately 45% of the funds required to build the telescope. Project Office efforts are currently focused on advancing the telescope and enclosure design in preparation for subsystem- and system-level preliminary design reviews which are scheduled to be completed in the first half of 2013.

  10. Rotation of Giant Stars

    NASA Astrophysics Data System (ADS)

    Kissin, Yevgeni; Thompson, Christopher

    2015-07-01

    The internal rotation of post-main sequence stars is investigated, in response to the convective pumping of angular momentum toward the stellar core, combined with a tight magnetic coupling between core and envelope. The spin evolution is calculated using model stars of initial mass 1, 1.5, and 5 {M}⊙ , taking into account mass loss on the giant branches. We also include the deposition of orbital angular momentum from a sub-stellar companion, as influenced by tidal drag along with the excitation of orbital eccentricity by a fluctuating gravitational quadrupole moment. A range of angular velocity profiles {{Ω }}(r) is considered in the envelope, extending from solid rotation to constant specific angular momentum. We focus on the backreaction of the Coriolis force, and the threshold for dynamo action in the inner envelope. Quantitative agreement with measurements of core rotation in subgiants and post-He core flash stars by Kepler is obtained with a two-layer angular velocity profile: uniform specific angular momentum where the Coriolis parameter {Co}\\equiv {{Ω }}{τ }{con}≲ 1 (here {τ }{con} is the convective time), and {{Ω }}(r)\\propto {r}-1 where {Co}≳ 1. The inner profile is interpreted in terms of a balance between the Coriolis force and angular pressure gradients driven by radially extended convective plumes. Inward angular momentum pumping reduces the surface rotation of subgiants, and the need for a rejuvenated magnetic wind torque. The co-evolution of internal magnetic fields and rotation is considered in Kissin & Thompson, along with the breaking of the rotational coupling between core and envelope due to heavy mass loss.

  11. A new approach for the synthesis of hyperbranched N-glycan core structures from locust bean gum.

    PubMed

    Ravi Kumar, H V; Naruchi, Kentaro; Miyoshi, Risho; Hinou, Hiroshi; Nishimura, Shin-Ichiro

    2013-12-20

    A novel protocol for the synthesis of general N-glycan core structures was established by means of Manβ(1→4)Man peracetate derived from a naturally abundant locust bean gum as a key starting material. Phenyl (2-O-benzyl-4,6-O-benzylidine-β-D-mannopyranosyl)-(1→4)-3,6-di-O-benzyl-2-azido-2-deoxy-1-thio-β-D-glucopyranoside facilitated the synthesis of key intermediates leading to hyperbranched N-glycan core structures.

  12. Level II scour analysis for Bridge 25 (BRNATH00290034) on Town Highway 29, crossing Locust Creek, Barnard, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Weber, Matthew A.

    1996-01-01

    The Town Highway 29 crossing of Locust Creek is a 37-ft-long, one-lane bridge consisting of one 32-foot concrete span (Vermont Agency of Transportation, written communication, August 23, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 25 degrees to the opening while the opening-skew-to-roadway is 25 degrees. There was no observable scour protection measure at the site. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.

  13. Level II scour analysis for Bridge 28 (BRNATH00660028) on Town Highway 66, crossing Locust Creek, Barnard, Vermont

    USGS Publications Warehouse

    Severence, Timothy

    1997-01-01

    The Town Highway 66 crossing of the Locust Creek is a 41-ft-long, one-lane bridge consisting of a 39 ft steel stringer type bridge with a concrete deck (Vermont Agency of Transportation, written communication, August 24, 1994). The clear span is 36.8 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The upstream right wingwall is protected by stone fill. The channel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is 0 degrees. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.

  14. Indigenous perception and characterization of Yanyanku and Ikpiru: two functional additives for the fermentation of African locust bean.

    PubMed

    Agbobatinkpo, Pélagie B; Azokpota, Paulin; Akissoe, Noël; Kayodé, Polycarpe; Da Gbadji, Rachelle; Hounhouigan, D Joseph

    2011-01-01

    Indigenous perception, processing methods, and physicochemical and microbiological characteristics of Yanyanku and Ikpiru, two additives used to produce fermented African locust bean condiments, Sonru and Iru, were evaluated. According to producers, these additives accelerate the fermentation and soften the texture of the condiments. Yanyanku is produced by spontaneous fermentation with either Hibiscus sabdariffa or Gossypium hirsutum or Adansonia digitata seeds, whereas only Hibiscus sabdariffa seeds are used for Ikpiru. Both additives, with pH values ranging between 6.2 and 10 and Bacillus spores varying between 5.5 and 8.9 Log(10) (CFU/g), could be considered as softening additives or enrichment inocula to produce condiments.

  15. Rheological and kinetic study of the ultrasonic degradation of locust bean gum in aqueous saline and salt-free solutions.

    PubMed

    Li, Ruoshi; Feke, Donald L

    2015-11-01

    The ultrasonic degradation of locust bean gum (LBG) in aqueous solutions has been studied at 25°C for ultrasonication times up to 120 min. Although LBG is not a polyelectrolyte, the degradation extent and kinetics were found to be somewhat sensitive to the ionic conditions in solution, and this is attributed to changes in molecular conformation that can occur in different salt environments. Ultrasonic degradation was tracked by rheological measurements that lead to the determination of intrinsic viscosity for the LBG molecules. A kinetic model was also developed and successfully applied to characterize and predict the degradation results.

  16. Polymyalgia Rheumatica and Giant Cell Arteritis

    MedlinePlus

    ... Clinical Trial Journal Articles Polymyalgia Rheumatica and Giant Cell Arteritis May 2016 Questions and Answers about Polymyalgia Rheumatica and Giant Cell Arteritis This publication contains general information about polymyalgia ...

  17. Giant cell tumour of the mandibular condyle.

    PubMed

    Della Sala, S W; Recla, M; Campolongo, F; Bortot, G; Bauer, M; Peterlongo, P

    1996-01-01

    The authors report a case of giant cell tumour of the mandibular condyle, which is a rare finding. This tumour, studied using the main three radiological modalities (plain radiography, CT and MRI) showed characteristic radiological features of "giant cell tumour".

  18. Giant lobelias exemplify convergent evolution.

    PubMed

    Givnish, Thomas J

    2010-01-14

    Giant lobeliads on tropical mountains in East Africa and Hawaii have highly unusual, giant-rosette growth forms that appear to be convergent on each other and on those of several independently evolved groups of Asteraceae and other families. A recent phylogenetic analysis by Antonelli, based on sequencing the widest selection of lobeliads to date, raises doubts about this paradigmatic example of convergent evolution. Here I address the kinds of evidence needed to test for convergent evolution and argue that the analysis by Antonelli fails on four points. Antonelli's analysis makes several important contributions to our understanding of lobeliad evolution and geographic spread, but his claim regarding convergence appears to be invalid. Giant lobeliads in Hawaii and Africa represent paradigmatic examples of convergent evolution.

  19. Structure of giant muscle proteins

    PubMed Central

    Meyer, Logan C.; Wright, Nathan T.

    2013-01-01

    Giant muscle proteins (e.g., titin, nebulin, and obscurin) play a seminal role in muscle elasticity, stretch response, and sarcomeric organization. Each giant protein consists of multiple tandem structural domains, usually arranged in a modular fashion spanning 500 kDa to 4 MDa. Although many of the domains are similar in structure, subtle differences create a unique function of each domain. Recent high and low resolution structural and dynamic studies now suggest more nuanced overall protein structures than previously realized. These findings show that atomic structure, interactions between tandem domains, and intrasarcomeric environment all influence the shape, motion, and therefore function of giant proteins. In this article we will review the current understanding of titin, obscurin, and nebulin structure, from the atomic level through the molecular level. PMID:24376425

  20. CMB lensing and giant rings

    SciTech Connect

    Rathaus, Ben; Itzhaki, Nissan E-mail: ben.rathaus@gmail.com

    2012-05-01

    We study the CMB lensing signature of a pre-inationary particle (PIP), assuming it is responsible for the giant rings anomaly that was found recently in the WMAP data. Simulating Planck-like data we find that generically the CMB lensing signal to noise ratio associated with such a PIP is quite small and it would be difficult to cross correlate the temperature giant rings with the CMB lensing signal. However, if the pre-inationary particle is also responsible for the bulk flow measured from the local large scale structure, which happens to point roughly at the same direction as the giant rings, then the CMB lensing signal to noise ratio is fairly significant.

  1. Giant lobelias exemplify convergent evolution

    PubMed Central

    2010-01-01

    Giant lobeliads on tropical mountains in East Africa and Hawaii have highly unusual, giant-rosette growth forms that appear to be convergent on each other and on those of several independently evolved groups of Asteraceae and other families. A recent phylogenetic analysis by Antonelli, based on sequencing the widest selection of lobeliads to date, raises doubts about this paradigmatic example of convergent evolution. Here I address the kinds of evidence needed to test for convergent evolution and argue that the analysis by Antonelli fails on four points. Antonelli's analysis makes several important contributions to our understanding of lobeliad evolution and geographic spread, but his claim regarding convergence appears to be invalid. Giant lobeliads in Hawaii and Africa represent paradigmatic examples of convergent evolution. PMID:20074322

  2. Atmospheres of Extrasolar Giant Planets

    NASA Astrophysics Data System (ADS)

    Marley, M. S.; Fortney, J.; Seager, S.; Barman, T.

    The key to understanding an extrasolar giant planet's spectrum - and hence its detectability and evolution - lies with its atmosphere. Now that direct observations of thermal emission from extrasolar giant planets (EGPs) are in hand, atmosphere models can be used to constrain atmospheric composition, thermal structure, and ultimately the formation and evolution of detected planets. We review the important physical processes that influence the atmospheric structure and evolution of EGPs and consider what has already been learned from the first generation of observations and modeling. We pay particular attention to the roles of cloud structure, metallicity, and atmospheric chemistry in affecting detectable properties through Spitzer Space Telescope observations of the transiting giant planets. Our review stresses the uncertainties that ultimately limit our ability to interpret EGP observations. Finally we will conclude with a look to the future as characterization of multiple individual planets in a single stellar system leads to the study of comparative planetary architectures.

  3. Selective actions of Lynx proteins on different nicotinic acetylcholine receptors in the locust, Locusta migratoria manilensis.

    PubMed

    Wang, Xin; Bao, Haibo; Sun, Huahua; Zhang, Yixi; Fang, Jichao; Liu, Qinghong; Liu, Zewen

    2015-08-01

    Nicotinic acetylcholine receptors (nAChRs) are major neurotransmitter receptors and targets of neonicotinoid insecticides in the insect nervous system. The full function of nAChRs is often dependent on associated proteins, such as chaperones, regulators and modulators. Here, three Lynx (Ly-6/neurotoxin) proteins, Loc-lynx1, Loc-lynx2 and Loc-lynx3, were identified in the locust, Locusta migratoria manilensis. Co-expression with Lynx resulted in a dramatic increase in agonist-evoked macroscopic currents on nAChRs Locα1/β2 and Locα2/β2 in Xenopus oocytes, but no changes in agonist sensitivity. Loc-lynx1 and Loc-lynx3 only modulated nAChRs Locα1/β2 while Loc-lynx2 modulated Locα2/β2 specifically. Meanwhile, Loc-lynx1 induced a more significant increase in currents evoked by imidacloprid and epibatidine than Loc-lynx3, and the effects of Loc-lynx1 on imidacloprid and epibatidine were significantly higher than those on acetylcholine. Among three lynx proteins, only Loc-lynx1 significantly increased [(3) H]epibatidine binding on Locα1/β2. The results indicated that Loc-lynx1 had different modulation patterns in nAChRs compared to Loc-lynx2 and Loc-lynx3. Taken together, these findings indicated that three Lynx proteins were nAChR modulators and had selective activities in different nAChRs. Lynx proteins might display their selectivities from three aspects: nAChR subtypes, various agonists and different modulation patterns. Insect Lynx (Ly-6/neurotoxin) proteins act as the allosteric modulators on insect nicotinic acetylcholine receptors (nAChRs), the important targets of insecticides. We found that insect lynx proteins showed their selectivities from at least three aspects: nAChR subtypes, various agonists and different modulation patterns.

  4. Transformation of polarized light information in the central complex of the locust.

    PubMed

    Heinze, Stanley; Gotthardt, Sascha; Homberg, Uwe

    2009-09-23

    Many insects perceive the E-vector orientation of polarized skylight and use it for compass navigation. In locusts, polarized light is detected by photoreceptors of the dorsal rim area of the eye. Polarized light signals from both eyes are integrated in the central complex (CC), a group of neuropils in the center of the brain. Thirteen types of CC neuron are sensitive to dorsally presented, polarized light (POL-neurons). These neurons interconnect the subdivisions of the CC, particularly the protocerebral bridge (PB), the upper and lower divisions of the central body (CBU, CBL), and the adjacent lateral accessory lobes (LALs). All POL-neurons show polarization-opponency, i.e., receive excitatory and inhibitory input at orthogonal E-vector orientations. To provide physiological evidence for the direction of information flow through the polarization vision network in the CC, we analyzed the functional properties of the different cell types through intracellular recordings. Tangential neurons of the CBL showed highest signal-to-noise ratio, received either ipsilateral polarized-light input only or, together with CL1 columnar neurons, had eccentric receptive fields. Bilateral polarized-light inputs with zenith-centered receptive fields were found in tangential neurons of the PB and in columnar neurons projecting to the LALs. Together with other physiological parameters, these data suggest a flow of information from the CBL (input) to the PB and from here to the LALs (output). This scheme is supported by anatomical data and suggests transformation of purely sensory E-vector coding at the CC input stage to position-invariant coding of 360 degrees -compass directions at the output stage.

  5. Novel etherified locust bean gum-alginate hydrogels for controlled release of glipizide.

    PubMed

    Dey, Paramita; Maiti, Sabyasachi; Sa, Biswanath

    2013-01-01

    On many occasions, homopolysaccharide hydrogel networks alone are not suitable for controlled drug delivery. In this study, interpenetrating networks (IPNs) of sodium alginate (ALG) and etherified locust bean gum (ELBG) were developed through ionotropic gelation with Al(3+) ions, tested for glipizide release, and were compared with homopolymer hydrogel networks. The degree of reticulation in IPNs was explained by the neutralization equivalent, tensile strength measurement, and drying kinetics of drug-free hydrogels. IPNs afforded a maximum of 94.40 ± 0.35% drug entrapment efficiency and exhibited slower drug release profiles up to 8 h. Al(3+)-ALG network almost completed the release of embedded drug in 3.5 h; however, the homopolymer Al(3+)-ELBG network discharged their content at a slow, uniform rate up to 8 h like the IPNs. All the networks appeared spherical under scanning electron microscope. In all cases, a faster drug release rate was assumed in phosphate buffer (pH 7.4) than in KCl/HCl buffer (pH 1.2) solution. The pH-responsive swelling of the beads was responsible for the variable drug release rate in different media. NonFickian diffusion mechanism was operative for the transport of drug from the IPNs. Moreover, IPNs gained appreciation for their better mechanical strength (63.79 ± 1.59 MPa) than Al(3+)-ELBG network. Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry, and X-ray diffraction analyses indicated a compatible environment for drug encapsualtion and release from the IPNs. The drug release curves of Al(3+)-ELBG and IPNs were found similar to a reference product. Hence, Al(3+)-ELBG and IPNs could be useful in controlling diabetes over longer periods.

  6. Distributions of nerve and muscle fibre types in locust jumping muscle.

    PubMed

    Hoyle, G

    1978-04-01

    Muscle fibres of the locust extensor tibiae (jumping muscle) were examined by interference microscopy and by electron microscopy. The electrical responses of single fibres and the mechanical responses of bundles or selected regions to the nerve fibres were examined. Four axons innervate the muscle: fast (FETi), slow (SETi), common inhibitor (CI) and dorsal unpaired median (DUMETi). Their distributions were examined by combined electrophysiological tracing and EM sectioning. The mean diameter of muscle fibres in different regions varies from 40 to 140 micrometer and is related to the local leg thickness rather than muscle fibre type. The fine structure of a fibre is related to its innervation. Fibres innervated by FETi but not SETi are of fast type ultrastructurally. Fibres innervated by SETi but not by FETi are of slow type ultrastructurally. Fibres innervated by both axons are generally intermediate between the extremes though more nearly of fast type than slow. Distal slow muscle fibres have much slower relaxation rates than do proximal ones. The most proximal bundles are of mixed muscle fibre type. There is an abrupt transition from a mixed population to homogeneous fast type, in the muscle units immediately distal to the most proximal bundles. This transition is associated with the presence of DUMETi terminals on some of the fibres distal to the transition point. There are no SETi endings on these same fibres. Fibres innervated by both SETi and FETi are scattered throughout the leg, but are commonest in the dorsal bundles. The percentage of these increases progressively passing distally. The most distal muscle fibres are innervated by SETi but not by FETi. It is concluded that different regions of the muscle will play different roles functionally since they are differentially sensitive to the pattern of SETi discharge.

  7. Temperature dependence of distortion-product otoacoustic emissions in tympanal organs of locusts.

    PubMed

    Möckel, Doreen; Kössl, Manfred; Lang, Julian; Nowotny, Manuela

    2012-09-15

    Distortion-product otoacoustic emissions (DPOAEs) in tympanal organs of insects are vulnerable to manipulations that interfere with the animal's physiological state. Starting at a medium temperature, we raised and lowered the locust's body temperature within the range of 12 to 35°C by changing the temperature of the surrounding air, while recording DPOAEs. These experimental manipulations resulted in reversible amplitude changes of the 2f(1)-f(2) emission, which were dependent on stimulus frequency and level. Using low f(2) frequencies of up to 10 kHz, a temperature increase (median +8-9°C) led to an upward shift of DPOAE amplitudes of approximately +10 dB, whereas a temperature decrease (median -7°C) was followed by a reduction of DPOAE amplitudes by 3 to 5 dB. Both effects were only present in the range of the low-level component of DPOAE growth functions below L2 levels (levels of the f(2) stimulus) of approximately 30 dB SPL. DPOAEs evoked by higher stimulus levels as well as measurements using higher stimulation frequencies above 10 kHz remained unaffected by any temperature shifts. The Arrhenius activation energy was calculated from the -10 dB SPL thresholds (representing the low-level component) of growth functions, which had been measured with 8 and 10 kHz as f(2) frequencies and amounted to up to ~34 and 41 kJ mol(-1), respectively. Such activation energy values provide a hint that the dynein-tubulin system within the scolopidial receptors could play an essential part in the DPOAE generation in tympanal organs.

  8. Surviving a flood: effects of inundation period, temperature and embryonic development stage in locust eggs.

    PubMed

    Woodman, J D

    2015-08-01

    The Australian plague locust, Chortoicetes terminifera (Walker), is an important agricultural pest and oviposits into compacted soil across vast semi-arid and arid regions prone to irregular heavy summer rainfall. This study aimed to quantify the effects of flooding (control, 7, 14, 21, 28 and 35 days) at different temperatures (15, 20 and 25°C) and embryonic development stages (25 and 75%) on egg viability, hatchling nymph body mass and survival to second-instar. Egg viability after flooding was dependent on temperature and flood duration. Eggs inundated at 15°C showed ≥53.5% survival regardless of flood duration and development stage compared with ≤29.6% for eggs at 25°C for ≥21 days early in development and ≥14 days late in development. Hatchling nymphs did not differ in body mass relative to temperature or flood duration, but weighed more from eggs inundated early in development rather than late. Survival to second-instar was ≤55.1% at 15 and 20°C when eggs were flooded for ≥28 days late in development, ≤35.6% at 25°C when flooded for ≥28 days early in development, and zero when flooded for ≥21 days late in development. These results suggest that prolonged flooding in summer and early autumn may cause very high egg mortality and first-instar nymph mortality of any survivors, but is likely to only ever affect a small proportion of the metapopulation. More common flash flooding for ≤14 days is unlikely to cause high mortality and have any direct effect on distribution and abundance.

  9. Effect of deacetylation on the synergistic interaction of acetan with locust bean gum or konjac mannan.

    PubMed

    Ojinnaka, C; Brownsey, G J; Morris, E R; Morris, V J

    1997-12-01

    It has been discovered that deacetylation of the bacterial polysaccharide acetan promotes synergistic interactions with either locust bean gum (LBG) or konjac mannan (KM). Acetan is similar in structure to xanthan, and adopts a similar 5-fold conformation in the solid state. Like xanthan, it shows a thermally reversible order (helix)-disorder (coil) transition in solution. Both polymers have a cellulosic backbone with charged (anionic) sidechains attached at O-3 of alternate glucosyl residues, but the sidechains in acetan are longer (pentasaccharide rather than trisaccharide) and do not contain pyruvic substituents. Acetan has two sites of acetylation, one at O-6 of the inner mannosyl residue of the carbohydrate sidechains (as in xanthan) and the other on the polymer backbone (believed to be at O-6 of the branched glucosyl residues). Solutions of acetan or deacetylated acetan were equilibrated against 10 mM potassium chloride (to stabilise the ordered conformation) and were mixed (at 25 degrees C) with solutions of LBG or KM, also equilibrated against 10 mM potassium chloride. Unlike xanthan, native acetan showed no evidence of synergistic interaction with either LBG or KM. After deacetylation, however, large enhancements were observed in dilute-solution viscosity, and thermoreversible gels were formed at higher concentrations. With KM as co-synergist, gel melting was accompanied by an intense endotherm in differential scanning calorimetry. The magnitude of this endotherm increased with storage time at 25 degrees C, reaching a final value of delta H approximately 15.9 J/g (in comparison with delta H approximately 5.0 J/g for the order-disorder transition of deacetylated acetan alone). It is suggested that interaction occurs by formation of heterotypic junctions between the acetan backbone and unsubstituted regions of the plant polysaccharide, and that the acetate groups on native acetan promote solubility and hence inhibit association.

  10. Two types of extrajunctional L-glutamate receptors in locust muscle fibres.

    PubMed Central

    Cull-Candy, S G

    1976-01-01

    L-glutamate applied iontophoretically to the extrajunctional membrane of locust muscle produced a biphasic response, depolarization followed by hyperpolarization (i.e. DH-response). Applying L-glutamate and DL-ibotenate from multibarrel micropipettes allowed comparison of their extrajunctional responses. While glutamate produced a two component response, ibotenate produced a single component H-response. 2. The equilibrium values for the H-responses to L-glutamate and DL-ibotenate applied at the same extrajunctional site were very similar. The equilibrium value was 59-5 +/- 5-4 mV indicating an increased Cl- conductance. The H-response was reversed and abolished in Cl- free medium. Picrotoxin 10(-3) M selectively blocked the H-component of the DH-response in a reversible manner. 3. The possibility that the D- and H-responses arose from the activation of two distinct types of extrajunctional glutamate receptors was investigated. Desensitization of the glutamate H-response by ibotenate and vice versa indicated the presence of an extrajunctional H-receptor sensitive to glutamate and ibotenate and an extrajunctional D-receptor sensitive to glutamate and insensitive to ibotenate. The junctional depolarizing response to glutamate was insensitive to ibotenate. 4. The presence of junctionally occurring H-receptors could not be discounted, although, if present, they were not measurably activated by the excitatory transmitter. 5. Double logarithmic plots (coulomb dose vs. response) for the actions of glutamate and ibotenate on H-receptors had values of 0-75, indicating that both drugs act on the same receptors with similar mechanisms. The value for the action of glutamate on the D-receptors was 1-5. 6. While the extrajunctional D-receptors show analogies to the extrajunctional ACh receptors in vertebrate muscle, the significance of the extrajunctional H-receptors remains speculative. PMID:1255528

  11. Development and deposition of resilin in energy stores for locust jumping.

    PubMed

    Burrows, Malcolm

    2016-08-15

    Locusts jump by using a catapult mechanism in which energy produced by slow contractions of the extensor tibiae muscles of the hind legs is stored in distortions of the exoskeleton, most notably (1) the two semi-lunar processes at each knee joint and (2) the tendons of the extensor muscles themselves. The energy is then suddenly released from these stores to power the rapid, propulsive movements of the hind legs. The reliance on the mechanical storage of energy is likely to impact on jumping because growth occurs by a series of five moults, at each of which the exoskeleton is replaced by a new one. All developmental stages (instars) nevertheless jump as a means of forward locomotion, or as an escape movement. Here, I show that in each instar, resilin is added to the semi-lunar processes and to the core of the extensor tendons so that their thickness increases. As the next moult approaches, a new exoskeleton forms within the old one, with resilin already present in the new semi-lunar processes. The old exoskeleton, the tendons and their resilin are discarded at moulting. The resilin of the semi-lunar processes and tendons of the new instar is initially thin, but a similar pattern of deposition results in an increase of their thickness. In adults, resilin continues to be deposited so that at 4 weeks old the thickness in the semi-lunar processes has increased fourfold. These changes in the energy stores accompany changes in jumping ability and performance during each moulting cycle.

  12. Graded synaptic transmission between local interneurones and motor neurones in the metathoracic ganglion of the locust.

    PubMed Central

    Burrows, M; Siegler, M V

    1978-01-01

    1. In the metathoracic ganglion of the locust some neurones can effect changes in the membrane potential of identified post-synaptic motor neurones without themselves spiking. 2. These 'non-spiking' neurones have processes only within the metathoracic ganglion, and therefore are local intraganglionic interneurones. 3. The absence of spikes in the interneurones reflects their normal physiological state and is not due to the experimental conditions. 4. When the interneurones are depolarized by the injection of current pulses lasting several hundred milliseconds, post-synaptic motor neurones are either depolarized, or hyperpolarized, for the duration of the pulse. 5. The magnitude of the change in post-synaptic voltage is graded according to the amount of presynaptic current. 6. A number of physiological tests indicate that the graded effects upon motor neurones are mediated by chemical synaptic transmission. For example, an evoked hyperpolarization of a motor neurone can be reversed in polarity by simultaneously hyperpolarizing the motor neurone with injected current. 7. At their resting potential some interneurones tonically release sufficient transmitter to have a measurable post-synaptic effect. The injection of depolarizing and hyperpolarizing currents into these interneurones effects opposite changes in post-synaptic potential. 8. Other interneurones must be depolarized from resting potential before a post-synaptic effect is observed, and hyperpolarizing currents have no post-synaptic effect. In these interneurones it is estimated that a depolarization of only 2 mV is sufficient to effect the release of transmitter. 9. The membrane potentials of non-spiking interneurones can fluctuate by as much as 15 mV during active movements of the hind legs and individual p.s.p.s as large as 5 mV can be recorded. Therefore, summed p.s.p.s or even single ones are expected to be the electrophysiological signals effecting transmitter release from these interneurones. PMID

  13. Interactions between segmental leg central pattern generators during fictive rhythms in the locust.

    PubMed

    Ryckebusch, S; Laurent, G

    1994-12-01

    1. Rhythmic activity of leg motor neurons could be evoked in isolated locust thoracic ganglia as well as in preparations of two or three connected thoracic ganglia superfused with the muscarinic agonist pilocarpine. Rhythms were always more regular and reliably elicited in single isolated ganglia. When the ganglia were connected, rhythmic activity of leg motor neurons was not usually simultaneously evoked in all six hemiganglia. Typically, some of the hemiganglia were rhythmically active, whereas others showed tonic or highly irregular activity. 2. Action potentials from leg motor neuron pools were recorded extracellularly from motor nerves and cross-correlated with the use of standard algorithms. The following correlations were observed between activities of motor neurons in different hemisegments. 1) Within a segment, trochanteral levators were coactive with contralateral trochanteral depressors. This correlation was strong in the metathoracic ganglion, and weaker in the pro- and mesothoracic ganglia. 2) Coupling between levators on opposite sides of the same segment was variable in the pro- and mesothoracic ganglia, because phase relationships between levators were different in each preparation and could also change during the course of an experiment. In the metathoracic ganglion, levators on opposite sides were never coactive. 3) Trochanteral levators were often active within a short latency of levator bursts in an ipsilateral adjacent hemiganglion. In addition, levators in one segment were often inhibited during levators bursts in the ipsilateral adjacent segment. 4) Trochanteral levators were strongly coupled to ipsilateral adjacent trochanteral depressors, for all three thoracic ganglia. 3. The phase relationships between motor neuron activities revealed by cross-correlation are discussed in the context of what is known about the mechanisms involved in the control of intersegmental coupling during legged locomotion.

  14. Review of Giant cell arteritis

    PubMed Central

    Chacko, Joseph G.; Chacko, J. Anthony; Salter, Michael W.

    2014-01-01

    Giant-cell arteritis (GCA) is a systemic autoimmune disease affecting primarily the elderly. Giant cell arteritis can cause sudden and potentially bilateral sequential vision loss in the elderly. Therefore, it is considered a medical emergency in ophthalmology and a significant cause of morbidity in an increasingly aging population. Ophthalmologists need to be able to recognize the classic symptoms and signs of this disease, and then be able to work-up and treat these patients in an efficient manner. An in-depth review of GCA from the literature as well as personal clinical experience follows. PMID:25859139

  15. Charting the Giants

    NASA Astrophysics Data System (ADS)

    2004-06-01

    zero expansion asymptotically after an infinite time and has a flat geometry). All three observational tests by means of supernovae (green), the cosmic microwave background (blue) and galaxy clusters converge at a Universe around Ωm ~ 0.3 and ΩΛ ~ 0.7. The dark red region for the galaxy cluster determination corresponds to 95% certainty (2-sigma statistical deviation) when assuming good knowledge of all other cosmological parameters, and the light red region assumes a minimum knowledge. For the supernovae and WMAP results, the inner and outer regions corespond to 68% (1-sigma) and 95% certainty, respectively. References: Schuecker et al. 2003, A&A, 398, 867 (REFLEX); Tonry et al. 2003, ApJ, 594, 1 (supernovae); Riess et al. 2004, ApJ, 607, 665 (supernovae) Galaxy clusters are far from being evenly distributed in the Universe. Instead, they tend to conglomerate into even larger structures, "super-clusters". Thus, from stars which gather in galaxies, galaxies which congregate in clusters and clusters tying together in super-clusters, the Universe shows structuring on all scales, from the smallest to the largest ones. This is a relict of the very early (formation) epoch of the Universe, the so-called "inflationary" period. At that time, only a minuscule fraction of one second after the Big Bang, the tiny density fluctuations were amplified and over the eons, they gave birth to the much larger structures. Because of the link between the first fluctuations and the giant structures now observed, the unique REFLEX catalogue - the largest of its kind - allows astronomers to put considerable constraints on the content of the Universe, and in particular on the amount of dark matter that is believed to pervade it. Rather interestingly, these constraints are totally independent from all other methods so far used to assert the existence of dark matter, such as the study of very distant supernovae (see e.g. ESO PR 21/98) or the analysis of the Cosmic Microwave background (e

  16. Giant right atrial thrombi treated with thrombolysis

    PubMed Central

    Ruiz-Bailén, Manuel; López-Caler, Carmen; Castillo-Rivera, Ana; Rucabado-Aguilar, Luis; Cuadra, José Ángel Ramos; Toral, Juan Lara; Cabezas, Cristobal Lozano; Guerrero, Juan Carlos Fernández

    2008-01-01

    The present report describes giant atrial thrombi that were treated with thrombolysis in a community hospital. Two patients with giant atrial thrombi whose treatment involved complications are presented. Both patients developed cardiogenic shock and were treated unsuccessfully with thrombolysis. Because thrombolysis of giant thrombi may be ineffective, patients in this situation may require surgery. PMID:18401474

  17. Cabergoline treatment in invasive giant prolactinoma.

    PubMed

    Alsubaie, Sadeem; Almalki, Mussa H

    2014-01-01

    Patients with invasive giant prolactinoma suffer from a constellation of symptoms including headache, blurred vision, lethargy, and sexual dysfunction. Cabergoline, a potent dopamine agonist, is a known medication prescribed for the treatment of invasive giant prolactinoma. Here, we report a case of invasive giant prolactinoma in a 52-year-old Saudi male with dramatic response to cabergoline treatment clinically, biochemically, and radiologically.

  18. Giant right atrial thrombi treated with thrombolysis.

    PubMed

    Ruiz-Bailén, Manuel; López-Caler, Carmen; Castillo-Rivera, Ana; Rucabado-Aguilar, Luis; Ramos Cuadra, José Angel; Lara Toral, Juan; Lozano Cabezas, Cristobal; Fernández Guerrero, Juan Carlos

    2008-04-01

    The present report describes giant atrial thrombi that were treated with thrombolysis in a community hospital. Two patients with giant atrial thrombi whose treatment involved complications are presented. Both patients developed cardiogenic shock and were treated unsuccessfully with thrombolysis. Because thrombolysis of giant thrombi may be ineffective, patients in this situation may require surgery.

  19. Fine structure of the sensilla and immunolocalisation of odorant binding proteins in the cerci of the migratory locust, Locusta migratoria.

    PubMed

    Yu, Yanxue; Zhou, Shuhui; Zhang, Shangan; Zhang, Long

    2011-01-01

    Using light and electron microscopy (both scanning and transmission), we observed the presence of sensilla chaetica and hairs on the cerci of the migratory locust, Locusta migratoria L. (Orthoptera: Acrididae). Based on their fine structures, three types of sensilla chaetica were identified: long, medium, and short. Males presented significantly more numbers of medium and short sensilla chaetica than females (p<0.05). The other hairs can also be distinguished as long and short. Sensilla chaetica were mainly located on the distal parts of the cerci, while hairs were mostly found on the proximal parts. Several dendritic branches, enveloped by a dendritic sheath, are present in the lymph cavity of the sensilla chaetica. Long, medium, and short sensilla chaetica contain five, four and three dendrites, respectively. In contrast, no dendritic structure was observed in the cavity of the hairs. By immunocytochemistry experiments only odorant-binding protein 2 from L. migratoria (LmigOBP2) and chemosensory protein class I from the desert locust, Schistocerca gregaria Forsskål (SgreCSPI) strongly stained the outer lymph of sensilla chaetica of the cerci. The other two types of hairs were never labeled. The results indicate that the cerci might be involved in contact chemoreception processes.

  20. Neurons in the brain of the desert locust Schistocerca gregaria sensitive to polarized light at low stimulus elevations.

    PubMed

    Jerome Beetz, M; Pfeiffer, Keram; Homberg, Uwe

    2016-11-01

    Desert locusts (Schistocerca gregaria) sense the plane of dorsally presented polarized light through specialized dorsal eye regions that are likely adapted to exploit the polarization pattern of the blue sky for spatial orientation. Receptive fields of these dorsal rim photoreceptors and polarization-sensitive interneurons are directed toward the upper sky but may extend to elevations below 30°. Behavioral data, however, suggests that S. gregaria is even able to detect polarized light from ventral directions but physiological evidence for this is still lacking. In this study we characterized neurons in the locust brain showing polarization sensitivity at low elevations down to the horizon. In most neurons polarization sensitivity was absent or weak when stimulating from the zenith. All neurons, including projection and commissural neurons of the optic lobe and local interneurons of the central brain, are novel cell types, distinct from polarization-sensitive neurons studied so far. Painting dorsal rim areas in both eyes black to block visual input had no effect on the polarization sensitivity of these neurons, suggesting that they receive polarized light input from the main eye. A possible role of these neurons in flight stabilization or the perception of polarized light reflected from bodies of water or vegetation is discussed.

  1. Transcriptional Analysis of The Adaptive Digestive System of The Migratory Locust in Response to Plant Defensive Protease Inhibitors.

    PubMed

    Spit, Jornt; Holtof, Michiel; Badisco, Liesbet; Vergauwen, Lucia; Vogel, Elise; Knapen, Dries; Vanden Broeck, Jozef

    2016-09-01

    Herbivorous insects evolved adaptive mechanisms to compensate for the presence of plant defensive protease inhibitors (PI) in their food. The underlying regulatory mechanisms of these compensatory responses remain largely elusive. In the current study, we investigated the initiation of this adaptive response in the migratory locust, Locusta migratoria, via microarray analysis of gut tissues. Four hours after dietary uptake of PIs, 114 and 150 transcripts were respectively found up- or downregulated. The results suggest a quick trade-off between compensating for potential loss of digestive activity on the one hand, and stress tolerance, defense, and structural integrity of the gut on the other hand. We additionally addressed the role of a group of related upregulated hexamerin-like proteins in the PI-induced response. Simultaneous knockdown of corresponding transcripts by means of RNA interference resulted in a reduced capacity of the locust nymphs to cope with the effects of PI. Moreover, since insect hexamerins have been shown to bind Juvenile Hormone (JH), we also investigated the effect of JH on the proteolytic digestion in L. migratoria. Our results indicate that JH has a stimulatory effect on the expression of three homologous chymotrypsin genes, while knocking down the JH receptor (methoprene tolerant) led to opposite effects.

  2. Tomographic particle image velocimetry of desert locust wakes: instantaneous volumes combine to reveal hidden vortex elements and rapid wake deformation.

    PubMed

    Bomphrey, Richard J; Henningsson, Per; Michaelis, Dirk; Hollis, David

    2012-12-07

    Aerodynamic structures generated by animals in flight are unstable and complex. Recent progress in quantitative flow visualization has advanced our understanding of animal aerodynamics, but measurements have hitherto been limited to flow velocities at a plane through the wake. We applied an emergent, high-speed, volumetric fluid imaging technique (tomographic particle image velocimetry) to examine segments of the wake of desert locusts, capturing fully three-dimensional instantaneous flow fields. We used those flow fields to characterize the aerodynamic footprint in unprecedented detail and revealed previously unseen wake elements that would have gone undetected by two-dimensional or stereo-imaging technology. Vortex iso-surface topographies show the spatio-temporal signature of aerodynamic force generation manifest in the wake of locusts, and expose the extent to which animal wakes can deform, potentially leading to unreliable calculations of lift and thrust when using conventional diagnostic methods. We discuss implications for experimental design and analysis as volumetric flow imaging becomes more widespread.

  3. Identification of outliers in a genomic scan for selection along environmental gradients in the bamboo locust, Ceracris kiangsu

    PubMed Central

    Feng, Xiao-Jing; Jiang, Guo-Fang; Fan, Zhou

    2015-01-01

    Identification of loci under divergent selection is a key step in understanding the evolutionary process because those loci are responsible for the genetic variations that affect fitness in different environments. Understanding how environmental forces give rise to adaptive genetic variation is a challenge in pest control. Here, we performed an amplified fragment length polymorphism (AFLP) genome scan in populations of the bamboo locust, Ceracris kiangsu, to search for candidate loci that are influenced by selection along an environmental gradient in southern China. In outlier locus detection, loci that demonstrate significantly higher or lower among-population genetic differentiation than expected under neutrality are identified as outliers. We used several outlier detection methods to study the features of C. kiangsu, including method DFDIST, BayeScan, and logistic regression. A total of 97 outlier loci were detected in the C. kiangsu genome with very high statistical supports. Moreover, the results suggested that divergent selection arising from environmental variation has been driven by differences in temperature, precipitation, humidity and sunshine. These findings illustrate that divergent selection and potential local adaptation are prevalent in locusts despite seemingly high levels of gene flow. Thus, we propose that native environments in each population may induce divergent natural selection. PMID:26333424

  4. Comparison of MR Enteroclysis with Colonoscopy in Crohn's Disease-First Locust Bean Gum Study from Turkey

    PubMed Central

    Narin, Burcu; Sungurlu, Faik; Balci, Aysun; Arman, Alper; Kurdas, Oya O.; Simsek, Masum

    2009-01-01

    Background/Aim: The aim of this study was to compare magnetic resonance enteroclysis (MRE) findings with those of colonoscopy, using locust bean gum (LBG) as an oral contrast agent in the diagnosis and follow-up of patients with Crohn's disease. Materials and Methods: Nine patients with histologically proven Crohn's disease were enrolled in this study; MRE was performed within a week of colonoscopy. All patients were examined using a 1.5 T MR Scanner after per os administration of 850 mL of a combination of LBG and mannitol. After intravenous administration of 50 mg Eritromisin and 40 mg Scopolamine, images were obtained using a T2-weighted, balanced GRE, fat-suppressed T1-weighted sequence, before and after intravenous gadolinium administration. Bowel wall thickness and enhancement of inflamatory bowel wall were measured. Results: The oral ingestion of LBG was well tolerated and allowed optimal small and large bowel distention in all patients. MR findings correlated with the colonoscopy results. Additional inflammatory lesions of the colon and mesenteric inflamatory changes such as lymphadenopathy, conglomerate tumor, and fistulas were demonstrated. Contrast enhancement of the affected bowel wall was markedly increased and positive correlation was obtained between bowel wall enhancement and bowel wall thickness. Conclusion: Gadolinium-enhanced MRE with oral locust bean gum is very efficient in the detection and follow-up of the intestinal and extraintestinal findings of Crohn's disease. PMID:19794271

  5. The Geographical Distribution Of The Black Locust (Robinia Pseudoacacia L.) In Poland And Its Role On Non-Forest Land

    NASA Astrophysics Data System (ADS)

    Wojda, Tomasz; Klisz, Marcin; Jastrzębowski, Szymon; Mionskowski, Marcin; Szyp-Borowska, Iwona; Szczygieł, Krystyna

    2015-01-01

    The black locust (Robinia pseudoacacia L.) has been present in Poland for more than 200 years now, its range coming to encompass the entire country, albeit with a particular concentration of occurrence in the west. Overall, it is present in 3.4% of the stands making up Poland's "State Forests National Forest Holding" (Państwowe Gospodarstwo Leśne Lasy Państwowe), and is the dominant species in 0.1% of stands. Thanks to its producing durable wood of favourable energetic properties, this species is used in medium-rotation (≤ 40-year) plantations as well as in biomass energy plantations (where there is a 5-7-year rotation). In terms of its nectar production, the black locust is second only to lime as the Polish tree best serving the production of honey. While the species shows marked expansiveness in Poland, it has not thus far been placed on the list of aliens capable of threatening native species or natural habitats. Breeding of the species has been engaged in - if to only a limited extent - in Poland for some 20 years now, and 2 selected seed stands have been registered, as well as 34 plus trees and 2 seed orchards.

  6. Intracisternal granules in the adipokinetic cells of locusts are not degraded and apparently function as supplementary stores of secretory material.

    PubMed

    Harthoorn, L F; Diederen, J H; Oudejans, R C; Verstegen, M M; Vullings, H G; Van der Horst, D J

    2000-01-01

    The intracisternal granules in locust adipokinetic cells appear to represent accumulations of secretory material within cisternae of the rough endoplasmic reticulum. An important question is whether these granules are destined for degradation or represent stores of (pro)hormones. Two strategies were used to answer this question. First, cytochemistry was applied to elucidate the properties of intracisternal granules. The endocytic tracers horseradish peroxidase and wheat-germ agglutinin-conjugated horseradish peroxidase were used to facilitate the identification of endocytic, autophagic, and lysosomal organelles, which may be involved in the degradation of intracisternal granules. No intracisternal granules could be found within autophagosomes, and granules fused with endocytic and lysosomal organelles were not observed, nor could tracer be found within the granules. The lysosomal enzyme acid phosphatase was absent from the granules. Second, biochemical analysis of the content of intracisternal granules revealed that these granules contain prohormones as well as hormones. Prohormones were present in relatively higher amounts compared with ordinary secretory granules. Since the intracisternal granules in locust adipokinetic cells are not degraded and contain intact (pro)hormones it is concluded that they function as supplementary stores of secretory material.

  7. Transcriptional Analysis of The Adaptive Digestive System of The Migratory Locust in Response to Plant Defensive Protease Inhibitors

    PubMed Central

    Spit, Jornt; Holtof, Michiel; Badisco, Liesbet; Vergauwen, Lucia; Vogel, Elise; Knapen, Dries; Vanden Broeck, Jozef

    2016-01-01

    Herbivorous insects evolved adaptive mechanisms to compensate for the presence of plant defensive protease inhibitors (PI) in their food. The underlying regulatory mechanisms of these compensatory responses remain largely elusive. In the current study, we investigated the initiation of this adaptive response in the migratory locust, Locusta migratoria, via microarray analysis of gut tissues. Four hours after dietary uptake of PIs, 114 and 150 transcripts were respectively found up- or downregulated. The results suggest a quick trade-off between compensating for potential loss of digestive activity on the one hand, and stress tolerance, defense, and structural integrity of the gut on the other hand. We additionally addressed the role of a group of related upregulated hexamerin-like proteins in the PI-induced response. Simultaneous knockdown of corresponding transcripts by means of RNA interference resulted in a reduced capacity of the locust nymphs to cope with the effects of PI. Moreover, since insect hexamerins have been shown to bind Juvenile Hormone (JH), we also investigated the effect of JH on the proteolytic digestion in L. migratoria. Our results indicate that JH has a stimulatory effect on the expression of three homologous chymotrypsin genes, while knocking down the JH receptor (methoprene tolerant) led to opposite effects. PMID:27581362

  8. Bacterial species and mycotoxin contamination associated with locust bean, melon and their fermented products in south-western Nigeria.

    PubMed

    Adedeji, Bamidele S; Ezeokoli, Obinna T; Ezekiel, Chibundu N; Obadina, Adewale O; Somorin, Yinka M; Sulyok, Michael; Adeleke, Rasheed A; Warth, Benedikt; Nwangburuka, Cyril C; Omemu, Adebukola M; Oyewole, Olusola B; Krska, Rudolf

    2017-10-03

    The microbiological safety of spontaneously fermented foods is not always guaranteed due to the undefined fermenting microbial consortium and processing materials. In this study, two commonly consumed traditional condiments (iru and ogiri) and their respective raw seeds (locust bean and melon) purchased from markets in south-western Nigeria were assessed for bacterial diversity and mycotoxin contamination using 16S rRNA gene sequencing and liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively. Two hundred isolates obtained from the raw seeds and condiments clustered into 10 operational taxonomic units (OTUs) and spanned 3 phyla, 10 genera, 14 species and 2 sub-species. Bacillus (25%) and Staphylococcus (23.5%) dominated other genera. Potentially pathogenic species such as Alcaligenes faecalis, Bacillus anthracis, Proteus mirabilis and Staphylococcus sciuri subsp. sciuri occurred in the samples, suggesting poor hygienic practice during production and/or handling of the condiments. A total of 48 microbial metabolites including 7 mycotoxins [3-nitropropionic acid, aflatoxin B1 (AFB1), AFB2, beauvericin, citrinin, ochratoxin A and sterigmatocystin] were quantified in the food samples. Melon and ogiri had detectable aflatoxin levels whereas locust bean and iru did not; the overall mycotoxin levels in the food samples were low. There is a need to educate processors/vendors of these condiments on good hygienic and processing practices. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. The SID-1 double-stranded RNA transporter is not required for systemic RNAi in the migratory locust.

    PubMed

    Luo, Yuan; Wang, Xianhui; Yu, Dan; Kang, Le

    2012-05-01

    Systemic RNAi, the spreading of RNAi effects to cells and tissues that have not initially encountered a dsRNA trigger, is a common phenomenon in many organisms. However, the underlying mechanisms of systemic RNAi remain largely unknown. Here, we studied the characteristics and possible mechanisms of systemic RNAi in Locusta migratoria. We observed that the locust has pronounced sensitive systemic RNAi in response to dsRNA injection for both broadly-expressed as well as tissue-specific genes. Only a 30 pg (dsRNA / mg tissues) dose could induce significant systemic RNAi effects. Only one SID-1 ortholog (LmSID-1) was identified in the locust genome, which exhibited a progressively increasing expression pattern with development and its expression was enriched in the gonad. To test the role of LmSID-1 in systemic RNAi, we performed in vitro and in vivo experiments. The results from in vivo experiments showed that silencing of LmSID-1 gene dose not influence RNAi effects of other genes. The results from in vitro experiments confirmed that the expression of the LmSID-1 protein in Drosophila S2 cells could not enhance dsRNA uptake. Thus, these findings imply the existence of alternative mechanisms underlying insect systemic RNAi, which may be different from Caenorhabditis elegans or mammals.

  10. Physiological and Proteomic Responses of Diploid and Tetraploid Black Locust (Robinia pseudoacacia L.) Subjected to Salt Stress

    PubMed Central

    Wang, Zhiming; Wang, Mingyue; Liu, Likun; Meng, Fanjuan

    2013-01-01

    Tetraploid black locust (Robinia pseudoacacia L.) is adaptable to salt stress. Here, we compared morphological, physiological, ultrastructural, and proteomic traits of leaves in tetraploid black locust and its diploid relatives under salt stress. The results showed that diploid (2×) plants suffered from greater negative effects than those of tetraploid (4×) plants. After salt treatment, plant growth was inhibited, photosynthesis was reduced, reactive oxygen species, malondialdehyde content, and relative electrolyte leakage increased, and defense-related enzyme activities decreased in 2× compared to those in 4×. In addition, salt stress resulted in distorted chloroplasts, swollen thylakoid membranes, accumulation of plastoglobules, and increased starch grains in 2× compared to those in 4×. However, 4× developed diverse responses under salt stress. A comparative proteomic analysis revealed that 41 and 37 proteins were differentially expressed in 2× and 4×, respectively. These proteins were mainly involved in photosynthesis, stress and defense, energy, metabolism, transcription/translation, and transportation. Distinct patterns of protein changes between 2× and 4× were analyzed. Collectively, our results suggest that the plants showed significantly different responses to salt stress based on ploidy level of the plant. The 4× possessed a better salt protection mechanism than that of 2×, suggesting salt tolerance in the polyploid plant. PMID:24129170

  11. Transcriptional Analysis of The Adaptive Digestive System of The Migratory Locust in Response to Plant Defensive Protease Inhibitors

    NASA Astrophysics Data System (ADS)

    Spit, Jornt; Holtof, Michiel; Badisco, Liesbet; Vergauwen, Lucia; Vogel, Elise; Knapen, Dries; vanden Broeck, Jozef

    2016-09-01

    Herbivorous insects evolved adaptive mechanisms to compensate for the presence of plant defensive protease inhibitors (PI) in their food. The underlying regulatory mechanisms of these compensatory responses remain largely elusive. In the current study, we investigated the initiation of this adaptive response in the migratory locust, Locusta migratoria, via microarray analysis of gut tissues. Four hours after dietary uptake of PIs, 114 and 150 transcripts were respectively found up- or downregulated. The results suggest a quick trade-off between compensating for potential loss of digestive activity on the one hand, and stress tolerance, defense, and structural integrity of the gut on the other hand. We additionally addressed the role of a group of related upregulated hexamerin-like proteins in the PI-induced response. Simultaneous knockdown of corresponding transcripts by means of RNA interference resulted in a reduced capacity of the locust nymphs to cope with the effects of PI. Moreover, since insect hexamerins have been shown to bind Juvenile Hormone (JH), we also investigated the effect of JH on the proteolytic digestion in L. migratoria. Our results indicate that JH has a stimulatory effect on the expression of three homologous chymotrypsin genes, while knocking down the JH receptor (methoprene tolerant) led to opposite effects.

  12. Chemical identification, emission pattern and function of male-specific pheromones released by a rarely swarming locust, Schistocerca americana.

    PubMed

    Stahr, Christiane; Svatoš, Aleš; Seidelmann, Karsten

    2013-01-01

    Pheromones serve key functions in the biology of swarming locusts. However, research has focused largely on the mass-swarming desert locust, Schistocerca gregaria. We extended these investigations to the pheromonal profile of the rarely swarming American bird grasshopper, S. americana (Drury). The headspace of mature gregarious S. americana males contained three characteristic electroantennogram-active components: (Z)-3-nonen-1-ol, (Z)-2-octen-1-ol, and nonanal. These substances were accompanied by aromatics such as phenol that are also released by females and immatures. Male-specific pheromone components were released independently from epidermal gland cells, with the highest emission rate being for (Z)-3-nonen-1-ol from the abdomen and legs. The emission of the major compound, (Z)-3-nonen-1-ol, is stress-sensitive, and coincides with sexual maturity and crowding. The emission pattern strongly supports a role of (Z)-3-nonen-1-ol in the reproductive biology of S. americana. The pheromone is involved in courtship-inhibition and is used as mate assessment pheromone in cryptic female choice. In double mating experiments, females choose sperm of males with high (Z)-3-nonen-1-ol emission. Furthermore the pheromone accelerated maturation of immature adults and supports synchronization of sexual development.

  13. Tomographic particle image velocimetry of desert locust wakes: instantaneous volumes combine to reveal hidden vortex elements and rapid wake deformation

    PubMed Central

    Bomphrey, Richard J.; Henningsson, Per; Michaelis, Dirk; Hollis, David

    2012-01-01

    Aerodynamic structures generated by animals in flight are unstable and complex. Recent progress in quantitative flow visualization has advanced our understanding of animal aerodynamics, but measurements have hitherto been limited to flow velocities at a plane through the wake. We applied an emergent, high-speed, volumetric fluid imaging technique (tomographic particle image velocimetry) to examine segments of the wake of desert locusts, capturing fully three-dimensional instantaneous flow fields. We used those flow fields to characterize the aerodynamic footprint in unprecedented detail and revealed previously unseen wake elements that would have gone undetected by two-dimensional or stereo-imaging technology. Vortex iso-surface topographies show the spatio-temporal signature of aerodynamic force generation manifest in the wake of locusts, and expose the extent to which animal wakes can deform, potentially leading to unreliable calculations of lift and thrust when using conventional diagnostic methods. We discuss implications for experimental design and analysis as volumetric flow imaging becomes more widespread. PMID:22977102

  14. Diet drives the collective migrations and affects the immunity of Mormon crickets and locusts: A comparison of these potential superspreaders of disease

    USDA-ARS?s Scientific Manuscript database

    The need for resources is a major driver of animal migration and yet migration itself is energetically demanding. Mormon crickets and nymphal locusts readily engage in cannibalistic attacks that result in aligned, coordinated movement of individuals in massive bands that march daily for weeks at a ...

  15. Multilocus sequence typing of Metarhizium anisopliae var acridum isolates as microbial agents for locust and grasshopper control. Genbank Accession numbers FJ787311 to FJ787325

    USDA-ARS?s Scientific Manuscript database

    A growing interest in the biological control of locusts and grasshoppers (Acrididae) has led to the development of biopesticides based on naturally occurring pathogens which offers an environmentally safe alternative to chemical pesticides. However, the fungal strains which are being sought for biop...

  16. Robinia pseudoacacia (black locust) as day-roosts of male Myotis septentrionalis (northern Bats) on the Fernow Experimental Forest, West Virginia

    Treesearch

    W. Mark Ford; Sheldon F. Owen; John W. Edwards; Jane L. Rodrigue

    2006-01-01

    During the summer of 2003, we captured and radiotagged ten male Myotis septentrionalis (northern bats) on the Fernow Experimental Forest (FEF) in the Allegheny Mountains of West Virginia to investigate day-roost selection. Of 16 roosts that were located, 13 were in Robinia pseudoacacia (black locusts), five in snags and eight in...

  17. Identification of the short neuropeptide F precursor in the desert locust: evidence for an inhibitory role of sNPF in the control of feeding.

    PubMed

    Dillen, Senne; Verdonck, Rik; Zels, Sven; Van Wielendaele, Pieter; Vanden Broeck, Jozef

    2014-03-01

    Peptides of the short neuropeptide F (sNPF) family have been shown to modulate feeding behavior in a wide variety of insect species. While these peptides stimulate feeding and food-searching behavior in Drosophila melanogaster and Apis mellifera, an opposite effect has recently been demonstrated in the desert locust, Schistocerca gregaria. In this study, we elaborate on these observations with the identification of the nucleotide sequence encoding the Schgr-sNPF precursor and the study of its role in the regulation of locust feeding behavior. We confirm that both Schgr-sNPF-like peptides, previously identified in mass spectrometric studies, are genuine precursor-encoded peptides. RNA interference mediated silencing of the Schgr-sNPF precursor transcript generates novel evidence for an inhibitory role of Schgr-sNPF in the regulation of feeding in S. gregaria. Furthermore, we show that starvation reduces the Schgr-sNPF precursor transcript level in the optic lobes, the primary visual centers of the locust brain. Our data indicate that Schgr-sNPF exerts an inhibitory effect on food uptake in the desert locust, which contrasts with effects of sNPF reported for several other insect species.

  18. Application of sugar maple and black locust to the biomass/energy-plantation concept. Annual report, March 1, 1981-February 28, 1982

    SciTech Connect

    Sajdak, R.L.

    1982-03-01

    The purpose of this research program is to determine the feasibility of converting existing pole-size maple stands to biomass/energy plantations using black locust as an interplanted species. Methods to quantify biomass production in northern hardwood stands have been refined and additional sites have been sampled. Hardwood sprout biomass production was shown to be greatly affected by site, fertilizer treatment, and tree species. Screening of black locust Rhizobium strains for acid tolerance has been completed. Seven strains have been found to be tolerant of both high aluminum and low pH conditions. A greenhouse and outplanting study testing the competitiveness and nitrogen-fixing ability of these strains under forest conditions has begun. Second year results of black locust provenance testing has shown frost hardiness variation among trees to be greater than among sources. Consequently, present work is now concentrated on propagating northern locust sources vegetatively. Biomass characterization of young northern hardwood sprouts by chemical and thermal analysis is complete.

  19. Phase-dependent locomotor activity in first-stadium nymphs of the desert locust, Schistocerca gregaria: effects of parental and progeny rearing density.

    PubMed

    Harano, Ken-ichi; Tanaka, Seiji; Watari, Yasuhiko; Saito, Osamu

    2012-05-01

    This study examined the effects of parental and progeny rearing density on locomotor activity of 1st-stadium nymphs of the desert locust, Schistocerca gregaria, using an actograph. Progeny obtained from solitarious (isolated-reared) or gregarious (crowd-reared) locusts were reared in isolation or in a group of 30 nymphs. Crowding after hatching had a slight influence on mean activity shortly after the start of measurements, but no clear effect was detected until day 2, when maximum activity during the 6-24 h of observation was significantly higher than that of the nymphs kept in isolation. On the other hand, the effects of parental rearing density on locomotor activity manifested at all ages examined (0-2 days old). Progeny of gregarious locusts showed consistently higher activity than those of solitarious locusts. In newly hatched nymphs, the effect of parental rearing density was explained by variation in body size at hatching, one of the phase-dependent characteristics. Hatchling body color was also correlated with locomotor activity and body weight. Similar levels of locomotor activity were exhibited when green, solitarious and black, gregarious nymphs were similar in body weight. These results suggested that parental rearing density indirectly influences locomotor activity in the progeny shortly after hatching by affecting their body size as eggs or hatchlings. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Giant Serpentine Aneurysms: Multidisciplinary Management

    PubMed Central

    Anshun, W.; Feng, L.; Daming, W.

    2000-01-01

    Summary Sixty-five cases of intracranial giant serpentine aneurysms (GSΛs), including 61 cases reported in the literature and four additional cases presented in this study were reviewed. The clinical presentation, possible causes, natural history, and especially management of GSAs are discussed with emphasis on the need for aggressive intervention and multidisciplinary management. PMID:20667180

  1. The giant panda gut microbiome.

    PubMed

    Wei, Fuwen; Wang, Xiao; Wu, Qi

    2015-08-01

    Giant pandas (Ailuropoda melanoleuca) are bamboo specialists that evolved from carnivores. Their gut microbiota probably aids in the digestion of cellulose and this is considered an example of gut microbiota adaptation to a bamboo diet. However, this issue remains unresolved and further functional and compositional studies are needed.

  2. Controlling nucleation in giant liposomes.

    PubMed

    Tester, Chantel C; Whittaker, Michael L; Joester, Derk

    2014-05-30

    We introduce giant liposomes to investigate phase transformations in picoliter volumes. Precipitation of calcium carbonate in the confinement of DPPC liposomes leads to dramatic stabilization of amorphous calcium carbonate (ACC). In contrast, amorphous strontium carbonate (ASC) is a transient species, and BaCO3 precipitation leads directly to the formation of crystalline witherite.

  3. Electrophysiological Recordings from Lobula Plate Tangential Cells in Drosophila.

    PubMed

    Mauss, Alex S; Borst, Alexander

    2016-01-01

    Drosophila has emerged as an important model organism for the study of the neural basis of behavior. Its main asset is the experimental accessibility of identified neurons by genetic manipulation and physiological recordings. Drosophila therefore offers the opportunity to reach an integrative understanding of the development and neural underpinnings of behavior at all processing stages, from sensing to motor control, in a single species. Here, we will provide an account of the procedures involved in recording the electrical potential of individual neurons in the visual system of adult Drosophila using the whole-cell patch-clamp method. To this end, animals are fixed to a holder and mounted below a recording chamber. The head capsule is cut open and the glial sheath covering the brain is ruptured by a combination of shearing and enzymatic digest. Neuronal somata are thus exposed and targeted by low-resistance patch electrodes. After formation of a high resistance seal, electrical access to the cell is gained by small current pulses and suction. Stable recordings of large neurons are feasible for >1 h and can be combined with controlled visual stimulation as well as genetic and pharmacological manipulation of upstream circuit elements to infer circuit function in great detail.

  4. Nursery of Giants

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Hidden behind a shroud of dust in the constellation Cygnus is a stellar nursery called DR21, which is giving birth to some of the most massive stars in our galaxy. Visible light images reveal no trace of this interstellar cauldron because of heavy dust obscuration. In fact, visible light is attenuated in DR21 by a factor of more than 10,000,000,000,000,000,000,000,000,000,000,000,000,000 (ten thousand trillion heptillion).

    New images from NASA's Spitzer Space Telescope allow us to peek behind the cosmic veil and pinpoint one of the most massive natal stars yet seen in our Milky Way galaxy. The never-before-seen star is 100,000 times as bright as the Sun. Also revealed for the first time is a powerful outflow of hot gas emanating from this star and bursting through a giant molecular cloud.

    This image is a large-scale mosaic assembled from individual photographs obtained with the InfraRed Array Camera (IRAC) aboard Spitzer. The image covers an area about two times that of a full moon. The mosaic is a composite of images obtained at mid-infrared wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red). The brightest infrared cloud near the top center corresponds to DR21, which presumably contains a cluster of newly forming stars at a distance of 10,000 light-years.

    Protruding out from DR21 toward the bottom left of the image is a gaseous outflow (green), containing both carbon monoxide and molecular hydrogen. Data from the Spitzer spectrograph, which breaks light into its constituent individual wavelengths, indicate the presence of hot steam formed as the outflow heats the surrounding molecular gas. Outflows are physical signatures of processes that create supersonic beams, or jets, of gas. They are usually accompanied by discs of material around the new star, which likely contain the materials from which future planetary systems are formed. Additional newborn stars, depicted in green, can be seen surrounding the

  5. Nursery of Giants

    NASA Image and Video Library

    2004-04-13

    Hidden behind a shroud of dust in the constellation Cygnus is a stellar nursery called DR21, which is giving birth to some of the most massive stars in our galaxy. Visible light images reveal no trace of this interstellar cauldron because of heavy dust obscuration. In fact, visible light is attenuated in DR21 by a factor of more than 10,000,000,000,000,000,000,000,000,000,000,000,000,000 (ten thousand trillion heptillion). New images from NASA's Spitzer Space Telescope allow us to peek behind the cosmic veil and pinpoint one of the most massive natal stars yet seen in our Milky Way galaxy. The never-before-seen star is 100,000 times as bright as the Sun. Also revealed for the first time is a powerful outflow of hot gas emanating from this star and bursting through a giant molecular cloud. This image is a large-scale mosaic assembled from individual photographs obtained with the InfraRed Array Camera (IRAC) aboard Spitzer. The image covers an area about two times that of a full moon. The mosaic is a composite of images obtained at mid-infrared wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red). The brightest infrared cloud near the top center corresponds to DR21, which presumably contains a cluster of newly forming stars at a distance of 10,000 light-years. Protruding out from DR21 toward the bottom left of the image is a gaseous outflow (green), containing both carbon monoxide and molecular hydrogen. Data from the Spitzer spectrograph, which breaks light into its constituent individual wavelengths, indicate the presence of hot steam formed as the outflow heats the surrounding molecular gas. Outflows are physical signatures of processes that create supersonic beams, or jets, of gas. They are usually accompanied by discs of material around the new star, which likely contain the materials from which future planetary systems are formed. Additional newborn stars, depicted in green, can be seen surrounding the DR21 region

  6. Opsin expression, physiological characterization and identification of photoreceptor cells in the dorsal rim area and main retina of the desert locust, Schistocerca gregaria.

    PubMed

    Schmeling, Fabian; Wakakuwa, Motohiro; Tegtmeier, Jennifer; Kinoshita, Michiyo; Bockhorst, Tobias; Arikawa, Kentaro; Homberg, Uwe

    2014-10-01

    For compass orientation many insects rely on the pattern of sky polarization, but some species also exploit the sky chromatic contrast. Desert locusts, Schistocerca gregaria, detect polarized light through a specialized dorsal rim area (DRA) in their compound eye. To better understand retinal mechanisms underlying visual navigation, we compared opsin expression, spectral and polarization sensitivities and response-stimulus intensity functions in the DRA and main retina of the locust. In addition to previously characterized opsins of long-wavelength-absorbing (Lo1) and blue-absorbing visual pigments (Lo2), we identified an opsin of an ultraviolet-absorbing visual pigment (LoUV). DRA photoreceptors exclusively expressed Lo2, had peak spectral sensitivities at 441 nm and showed high polarization sensitivity (PS 1.3-31.7). In contrast, ommatidia in the main eye co-expressed Lo1 and Lo2 in five photoreceptors, expressed Lo1 in two proximal photoreceptors, and Lo2 or LoUV in one distal photoreceptor. Correspondingly, we found broadband blue- and green-peaking spectral sensitivities in the main eye and one narrowly tuned UV peaking receptor. Polarization sensitivity in the main retina was low (PS 1.3-3.8). V-log I functions in the DRA were steeper than in the main retina, supporting a role in polarization vision. Desert locusts occur as two morphs, a day-active gregarious and a night-active solitarious form. In solitarious locusts, sensitivities in the main retina were generally shifted to longer wavelengths, particularly in ventral eye regions, supporting a nocturnal lifestyle at low light levels. The data support the role of the DRA in polarization vision and suggest trichromatic colour vision in the desert locust. © 2014. Published by The Company of Biologists Ltd.

  7. miR-71 and miR-263 Jointly Regulate Target Genes Chitin synthase and Chitinase to Control Locust Molting

    PubMed Central

    Jiang, Feng; Song, Tianqi; Wang, Huimin; Liu, Qing; Zhang, Jie; Zhang, Jianzhen; Kang, Le

    2016-01-01

    Chitin synthase and chitinase play crucial roles in chitin biosynthesis and degradation during insect molting. Silencing of Dicer-1 results in reduced levels of mature miRNAs and severely blocks molting in the migratory locust. However, the regulatory mechanism of miRNAs in the molting process of locusts has remained elusive. In this study, we found that in chitin metabolism, two crucial enzymes, chitin synthase (CHS) and chitinase (CHT) were regulated by miR-71 and miR-263 during nymph molting. The coding sequence of CHS1 and the 3’-untranslated region of CHT10 contain functional binding sites for miR-71 and miR-263, respectively. miR-71/miR-263 displayed cellular co-localization with their target genes in epidermal cells and directly interacted with CHS1 and CHT10 in the locust integument, respectively. Injections of miR-71 and miR-263 agomirs suppressed the expression of CHS1 and CHT10, which consequently altered chitin production of new and old cuticles and resulted in a molting-defective phenotype in locusts. Unexpectedly, reduced expression of miR-71 and miR-263 increased CHS1 and CHT10 mRNA expression and led to molting defects similar to those induced by miRNA delivery. This study reveals a novel function and balancing modulation pattern of two miRNAs in chitin biosynthesis and degradation, and it provides insight into the underlying molecular mechanisms of the molting process in locusts. PMID:27532544

  8. Locust bean gum as an alternative polymeric coating for embryonic stem cell culture.

    PubMed

    Perestrelo, Ana Rubina; Grenha, Ana; Rosa da Costa, Ana M; Belo, José António

    2014-07-01

    Pluripotent embryonic stem cells (ESCs) have self-renewal capacity and the potential to differentiate into any cellular type depending on specific cues (pluripotency) and, therefore, have become a vibrant research area in the biomedical field. ESCs are usually cultured in gelatin or on top of a monolayer of feeder cells such as mitotically inactivated mouse embryonic fibroblasts (MEFsi). The latter is the gold standard support to maintain the ESCs in the pluripotent state. Examples of versatile, non-animal derived and inexpensive materials that are able to support pluripotent ESCs are limited. Therefore, our aim was to find a biomaterial able to support ESC growth in a pluripotent state avoiding laborious and time consuming parallel culture of MEFsi and as simple to handle as gelatin. Many of the new biomaterials used to develop stem cell microenvironments are using natural polymers adsorbed or covalently attached to the surface to improve the biocompatibility of synthetic polymers. Locust beam gum (LBG) is a natural, edible polymer, which has a wide range of potential applications in different fields, such as food and pharmaceutical industry, due to its biocompatibility, adhesiveness and thickening properties. The present work brings a natural system based on the use of LBG as a coating for ESC culture. Undifferentiated mouse ESCs were cultured on commercially available LBG to evaluate its potential in maintaining pluripotent ESCs. In terms of morphology, ESC colonies in LBG presented the regular dome shape with bright borders, similar to the colonies obtained in co-cultures with MEFsi and characteristic of pluripotent ESC colonies. In short-term cultures, ESC proliferation in LBG coating was similar to ESC cultured in gelatin and the cells maintained their viability. The activity of alkaline phosphatase and Nanog, Sox2 and Oct4 expression of mouse ESCs cultured in LBG were comparable or in some cases higher than in ESCs cultured in gelatin. An in vitro

  9. Isoprene emission and photosynthesis during heatwaves and drought in black locust

    NASA Astrophysics Data System (ADS)

    Bamberger, Ines; Ruehr, Nadine K.; Schmitt, Michael; Gast, Andreas; Wohlfahrt, Georg; Arneth, Almut

    2017-08-01

    Extreme weather conditions like heatwaves and drought can substantially affect tree physiology and the emissions of isoprene. To date, however, there is only limited understanding of isoprene emission patterns during prolonged heat stress and next to no data on emission patterns during coupled heat-drought stress or during post-stress recovery. We studied gas exchange and isoprene emissions of black locust trees under episodic heat stress and in combination with drought. Heatwaves were simulated in a controlled greenhouse facility by exposing trees to outside temperatures +10 °C, and trees in the heat-drought treatment were supplied with half of the irrigation water given to heat and control trees. Leaf gas exchange of isoprene, CO2 and H2O was quantified using self-constructed, automatically operating chambers, which were permanently installed on leaves (n = 3 per treatment). Heat and combined heat-drought stress resulted in a sharp decline of net photosynthesis (Anet) and stomatal conductance. Simultaneously, isoprene emissions increased 6- to 8-fold in the heat and heat-drought treatment, which resulted in a carbon loss that was equivalent to 12 and 20 % of assimilated carbon at the time of measurement. Once temperature stress was released at the end of two 15-day-long heatwaves, stomatal conductance remained reduced, while isoprene emissions and Anet recovered quickly to values of the control trees. Further, we found that isoprene emissions covaried with Anet during nonstress conditions, while during the heatwaves, isoprene emissions were not related to Anet but to light and temperature. Under standard air temperature and light conditions (here 30 °C and photosynthetically active radiation of 500 µmol m-2 s-1), isoprene emissions of the heat trees were by 45 % and the heat-drought trees were by 27 % lower than in control trees. Moreover, temperature response curves showed that not only the isoprene emission factor changed during both heat and heat

  10. Rheology and synergy of κ-carrageenan/locust bean gum/konjac glucomannan gels.

    PubMed

    Brenner, Tom; Wang, Zheng; Achayuthakan, Piyada; Nakajima, Tetsuya; Nishinari, Katsuyoshi

    2013-10-15

    The rheology and melting of mixed polysaccharide gels containing konjac glucomannan (KGM), locust bean gum (LBG) and κ-carrageenan (KC) were studied. Synergy-type peaks in the Young's modulus at optimal mixing ratios were found for both KC/LBG and KC/KGM binary gels at a fixed total polysaccharide content (1:5.5 for LBG:KC and 1:7 for KGM:KC). The Young's modulus peak for KC/KGM was higher than for KC/LBG gels. The same stoichiometric mixing ratios were found when either LBG or KGM was added to KC at a fixed KC concentration, where the Young's modulus increased up to additions at the stoichiometric ratio, but leveled off at higher LBG or KGM additions. Addition of KGM or LBG to the 2-component gels beyond the stoichiometric (optimal) mixing ratio at a fixed total polysaccharide content led to a decrease in the Young's modulus and an increase in the rupture strain and stress in extension, and both trends were stronger for KGM than for LBG. Differential scanning calorimetry of the gels revealed the development of a second melting peak for the KC/KGM gels that increased with KGM addition up to higher KGM contents than the stoichiometric ratio. For the KC/LBG gels, only a slight broadening and shift to a higher temperature were observed. When the three polysaccharides were mixed, the DSC endotherms reflected only the main features of the interaction between KC and KGM, and the same was true for the fracture in extension. The different trends led to higher Young's moduli at intermediate KC concentrations when a 1:1 addition of LBG:KGM was used than when either only KGM or LBG was added at a fixed total polysaccharide concentration. This suggests that no special interactions arise when the three polysaccharides are mixed and the binding mechanisms are simply a sum of the bindings observed for KC/KGM and KC/LBG two-component gels.

  11. Giant Herbig-Haro Flows

    NASA Astrophysics Data System (ADS)

    Reipurth, Bo; Bally, John; Devine, David

    1997-12-01

    We present the discovery of a number of Herbig-Haro flows which extend over parsec-scale distances. The largest of these is the well known HH 111 jet complex, which is shown, through CCD images and a proper motion study, to have an angular extent of almost one degree on the sky, corresponding to 7.7 pc, making it the largest known HH flow. In our imaging survey we also found that T Tauri is at the center of a huge bipolar HH flow, HH 355, with a total extent of 38 arcmin, corresponding to 1.55 pc, and aligned with the axis of the tiny HH 255 flow surrounding the infrared companion T Tau S. We additionally have found a number of other giant HH flow candidates, including HH 315 at PV Cep, HH 41/295 at Haro 5a/6a, HH 300 in Bl8w, HH 354 in Li 165, HH 376 in Li 152, and HH 114/115 and HH 243/244/245/179 in the X Orionis molecular ring. It thus appears that it is common for HH flows to attain parsec-scale dimensions. The ubiquity of parsec-scale HH flows profoundly alters our view of the impact of young stars on their environment. Giant flows have dynamical ages comparable to the duration of the accretion phase of the sources, and provide a fossil record of their mass loss and accretion history. Multiple internal working surfaces and their S-shaped point symmetry provide evidence for variability of ejection velocity and orientation of the source jets. Giant HH flows are either longer or comparable in length to associated CO outflows, providing evidence for unified models in which HH flows power CO flows. Many giant flows have burst out of their source cloud cores and are dissociating molecules and injecting momentum and kinetic energy into the interclump medium of the host clouds. They contribute to the UV radiation field, and may produce C I and C ii in cloud interiors. Giant flows may contribute to the chemical rejuvenation of clouds, the generation of turbulent motions, and the self-regulation of star formation. The terminal working surfaces of giant flows may be

  12. Molecular and functional characterization of cDNAs putatively encoding carboxylesterases from the migratory locust, Locusta migratoria.

    PubMed

    Zhang, Jianqin; Li, Daqi; Ge, Pingting; Guo, Yaping; Zhu, Kun Yan; Ma, Enbo; Zhang, Jianzhen

    2014-01-01

    Carboxylesterases (CarEs) belong to a superfamily of metabolic enzymes encoded by a number of genes and are widely distributed in microbes, plants and animals including insects. These enzymes play important roles in detoxification of insecticides and other xenobiotics, degradation of pheromones, regulation of neurodevelopment, and control of animal development. In this study, we characterized a total of 39 full-length cDNAs putatively encoding different CarEs from the migratory locust, Locusta migratoria, one of the most severe insect pests in many regions of the world, and evaluated the role of four CarE genes in insecticide detoxification. Our phylogenetic analysis grouped the 39 CarEs into five different clades including 20 CarEs in clade A, 3 in D, 13 in E, 1 in F and 2 in I. Four CarE genes (LmCesA3, LmCesA20, LmCesD1, LmCesE1), representing three different clades (A, D and E), were selected for further analyses. The transcripts of the four genes were detectable in all the developmental stages and tissues examined. LmCesA3 and LmCesE1 were mainly expressed in the fat bodies and Malpighian tubules, whereas LmCesA20 and LmCesD1 were predominately expressed in the muscles and hemolymph, respectively. The injection of double-stranded RNA (dsRNA) synthesized from each of the four CarE genes followed by the bioassay with each of four insecticides (chlorpyrifos, malathion, carbaryl and deltamethrin) increased the nymphal mortalities by 37.2 and 28.4% in response to malathion after LmCesA20 and LmCesE1 were silenced, respectively. Thus, we proposed that both LmCesA20 and LmCesE1 played an important role in detoxification of malathion in the locust. These results are expected to help researchers reveal the characteristics of diverse CarEs and assess the risk of insecticide resistance conferred by CarEs in the locust and other insect species.

  13. Canopy transpiration of two black locust (Robinia pseudoacacia) plantations with different ages in semi-arid Loess Plateau, China

    NASA Astrophysics Data System (ADS)

    Jiao, L.

    2015-12-01

    Black locust (Robinia pseudoacacia) was widely planted to control soil erosion and restore degraded ecosystem in Loess Plateau. The water use of the plantations was concerned due to its potential effects on hydrological cycle and regional water resource. Although some studies estimated canopy transpiration (Ec) of the mature black locust plantation, variation in Ec in plantations with different ages was not clear. In this study, we selected two plantations with different ages (12 years and 27 years, denoted as young stand and mature stand, respectively) in similar topographical conditions in Yangjuangou catchment in the central of Loess Plateau. Sap flux density (Fd) and tree biometrics were measured in each stand during the growing season in 2014. Soil water content (SWC) in each plot and meteorological variables in the catchment were simultaneously monitored. Tree transpiration (Et) was derived from Fd and tree sapwood area (As). Canopy transpiration (Ec) was estimated by a product of mean stand sap flux density (Js) and stand total sapwood area (AST). The mean Fd of mature trees was 2-fold larger than that of young trees.However, tree-to-tree variation in Fd among sampled trees within mature stand was evident compared to that within young stand. Mean Et in mature stand was higher than that in young stand. Ec in mature stand was significant higher than that in young stand,with cumulative value of 54 mm and 27 mm respectively. This is attributed to higher Js in mature stand although AST in young is slightly higher than that in mature stand. The patterns of daily Ec during the growing season were similar in both stands during the study period. A exponential saturation model can explain the responses of Ec to vapor deficit pressure (VPD) and solar radiation (Rs) in both stands.The relationship between Ec and SWC was not detected. Our finding suggested that stand age should be taken into consideration when estimated vegetation water use in this region. Further

  14. Ultrastructure of GABA- and Tachykinin-Immunoreactive Neurons in the Lower Division of the Central Body of the Desert Locust

    PubMed Central

    Homberg, Uwe; Müller, Monika

    2016-01-01

    The central complex, a group of neuropils spanning the midline of the insect brain, plays a key role in spatial orientation and navigation. In the desert locust and other species, many neurons of the central complex are sensitive to the oscillation plane of polarized light above the animal and are likely involved in the coding of compass directions derived from the polarization pattern of the sky. Polarized light signals enter the locust central complex primarily through two types of γ-aminobutyric acid (GABA)-immunoreactive tangential neurons, termed TL2 and TL3 that innervate specific layers of the lower division of the central body (CBL). Candidate postsynaptic partners are columnar neurons (CL1) connecting the CBL to the protocerebral bridge (PB). Subsets of CL1 neurons are immunoreactive to antisera against locustatachykinin (LomTK). To better understand the synaptic connectivities of tangential and columnar neurons in the CBL, we studied its ultrastructural organization in the desert locust, both with conventional electron microscopy and in preparations immunolabeled for GABA or LomTK. Neuronal profiles in the CBL were rich in mitochondria and vesicles. Three types of vesicles were distinguished: small clear vesicles with diameters of 20–40 nm, dark dense-core vesicles (diameter 70–120 nm), and granular dense-core vesicles (diameter 70–80 nm). Neurons were connected via divergent dyads and, less frequently, through convergent dyads. GABA-immunoreactive neurons contained small clear vesicles and small numbers of dark dense core vesicles. They had both pre- and postsynaptic contacts but output synapses were observed more frequently than input synapses. LomTK immunostaining was concentrated on large granular vesicles; neurons had pre- and postsynaptic connections often with neurons assumed to be GABAergic. The data suggest that GABA-immunoreactive tangential neurons provide signals to postsynaptic neurons in the CBL, including LomTK-immunolabeled CL1

  15. Baratin, a nonamidated neurostimulating neuropeptide, isolated from cockroach brain: distribution and actions in the cockroach and locust nervous systems.

    PubMed

    Nässel, D R; Persson, M G; Muren, J E

    2000-06-26

    During the purification of tachykinin-related peptides from the brain of the cockroach Leucophaea maderae, a few other peptides were collected in adjacent high-performance liquid chromatography fractions. Edman degradation, mass spectrometry, and chemical synthesis revealed that one of these peptides had the sequence DNSQWGGFA. This nonamidated nonapeptide was designated baratin and appears not to be related to any known insect peptide. Baratin was not found to be bioactive in the L. maderae hindgut or oviduct muscle contraction assay. (Both synthetic nonamidated and amidated baratin were tested.) To screen for possible sites of action, we raised a rabbit antiserum to baratin. We found baratin-immunoreactive (BAR-IR) interneurons throughout the cockroach central nervous system. Some prominent brain neuropils were supplied by BAR-IR neuron processes: the central body, the calyx, and lobes of the mushroom bodies, parts of the optic lobe, and the tritocerebral neuropil. Additionally we found BAR-IR neurosecretory cells in the median neurosecretory cell group with processes supplying the storage lobe of the corpora cardiaca. In each of the thoracic and abdominal ganglia processes of BAR-IR projection neurons and local neurons were seen. The baratin antiserum also labeled neurons in the brain of the locust Locusta migratoria, some of which are similar to those of the cockroach. A prominent system of interganglionic BAR-IR processes was found in the locust subesophageal, thoracic, and abdominal ganglia. This was formed by four large projection neurons with cell bodies in the abdominal ganglia A1-2. The processes of these BAR-IR neurons are distributed dorsally and laterally in each of the ventral nerve cord ganglia. When baratin (10(-6)-10(-4) M) was applied to desheathed abdominal ganglia of locusts and cockroaches, we could monitor bursts of action potentials in neurons with axons in the anterior abdominal nerve (nerve 1), but not in the posterior nerve (nerve 2). In

  16. Giant viruses come of age.

    PubMed

    Fischer, Matthias G

    2016-06-01

    Viruses with genomes up to a few megabases in length are a common occurrence in nature, even though they have escaped our notice until recently. These giant viruses infect mainly single-celled eukaryotes and isolation efforts concentrating on amoebal hosts alone have spawned hundreds of viral isolates, featuring viruses with previously unseen virion morphologies and the largest known viral genomes and particles. One of the challenges that lie ahead is to analyze and categorize the available data and to establish an approved classification system that reflects the evolutionary relationships and biological properties of these viruses. Extensive sampling of Acanthamoeba-infecting mimiviruses and initial characterization of their virophage parasites have provided a first blueprint of the genetic diversity and composition of a giant virus clade that will facilitate the taxonomic grouping of these fascinating microorganisms.

  17. Proteorhodopsin genes in giant viruses.

    PubMed

    Yutin, Natalya; Koonin, Eugene V

    2012-10-04

    Viruses with large genomes encode numerous proteins that do not directly participate in virus biogenesis but rather modify key functional systems of infected cells. We report that a distinct group of giant viruses infecting unicellular eukaryotes that includes Organic Lake Phycodnaviruses and Phaeocystis globosa virus encode predicted proteorhodopsins that have not been previously detected in viruses. Search of metagenomic sequence data shows that putative viral proteorhodopsins are extremely abundant in marine environments. Phylogenetic analysis suggests that giant viruses acquired proteorhodopsins via horizontal gene transfer from proteorhodopsin-encoding protists although the actual donor(s) could not be presently identified. The pattern of conservation of the predicted functionally important amino acid residues suggests that viral proteorhodopsin homologs function as sensory rhodopsins. We hypothesize that viral rhodopsins modulate light-dependent signaling, in particular phototaxis, in infected protists.

  18. Giant thermoelectric effect in graphene

    NASA Astrophysics Data System (ADS)

    Dragoman, D.; Dragoman, M.

    2007-11-01

    The paper predicts a giant thermoelectric coefficient in a nanostructure consisting of metallic electrodes periodically patterned over graphene, which is deposited on a silicon dioxide substrate. The Seebeck coefficient in this device attains 30mV/K, this value being among the largest reported ever. The calculations are based on a transfer matrix approach that takes a particular form for graphene-based devices. The results are important for future nanogenerators with applications in the area of sensors, energy harvesting, and scavenging.

  19. [Treatment of giant acoustic neuromas].

    PubMed

    Samprón, Nicolás; Altuna, Xabier; Armendáriz, Mikel; Urculo, Enrique

    2014-01-01

    To analyze the treatment modality and outcome of a series of patients with giant acoustic neuromas, a particular type of tumour characterised by their size (extracanalicular diameter of 4cm or more) and high morbidity and mortality. This was a retrospective unicentre study of patients with acoustic neuromas treated in a period of 12 years. In our institutional series of 108 acoustic neuromas operated on during that period, we found 13 (12%) cases of giant acoustic neuromas. We reviewed the available data of these cases, including presentation and several clinical, anatomical, and microsurgical aspects. All patients were operated on by the same neurosurgeon and senior author (EU) using the suboccipital retrosigmoid approach and complete microsurgical removal was achieved in 10 cases. In one case, near total removal was deliberately performed, in another case a CSF shunt was placed as the sole treatment measure, and in the remaining case no direct treatment was given. One patient died in the immediate postoperative period. One year after surgery, 4 patients showed facial nerve function of iii or more in the House-Brackman scale. The 4 most important prognostic characteristics of giant acoustic neuromas are size, adhesion to surrounding structures, consistency and vascularity. Only the first of these is evident in neuroimaging. Giant acoustic neuromas are characterised by high morbidity at presentation as well as after treatment. Nevertheless, the objective of complete microsurgical removal with preservation of cranial nerve function is attainable in some cases through the suboccipital retrosigmoid approach. Copyright © 2014 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  20. Giant magnetoresistance in silicene nanoribbons.

    PubMed

    Xu, Chengyong; Luo, Guangfu; Liu, Qihang; Zheng, Jiaxin; Zhang, Zhimeng; Nagase, Shigeru; Gao, Zhengxiang; Lu, Jing

    2012-05-21

    By performing first-principle quantum transport calculations, we predict a giant magnetoresistance in zigzag silicene nanoribbons (ZSiNRs) connecting two semi-infinite silicene electrodes through switch of the edge spin direction of ZSiNRs. Spin-filter efficiency of both the antiferromagnetic and ferromagnetic ZSiNRs is sign-changeable with the bias voltage. Therefore, potential application of silicene in spintronics devices is suggested.

  1. Idiopathic giant right atrial aneurysm

    PubMed Central

    Uppu, Santosh C; Sachdeva, Ritu; Imamura, Michiaki

    2013-01-01

    A 2-year-old boy with an incidental finding of massive cardiomegaly on a chest X-ray was diagnosed with a giant right atrial aneurysm upon further investigation with echocardiography. The patient underwent successful surgical reduction of the right atrium and closure of the patent foramen ovale to prevent thromboembolic complications and to lower the risk of atrial arrhythmias. The resected atrium had paper-thin walls and pathological features of interstitial fibrosis with endocardial thickening. PMID:23626440

  2. Hairpin Furans and Giant Biaryls.

    PubMed

    Geng, Xin; Mague, Joel T; Donahue, James P; Pascal, Robert A

    2016-05-06

    The thermal reaction of two cyclopentadienones with 5,5'-binaphthoquinone or 6,6'-dimethoxy-5,5'-binaphthoquinone in refluxing nitrobenzene (210 °C) gives, in a single synthetic step that includes two Diels-Alder additions, two decarbonylations, and two dehydrogenations, giant biaryl bisquinones (compounds 13, 14, 15, 18, and 21). However, when two cyclopentadienones react with 6,6'-dimethoxy-5,5'-binaphthoquinone in nitrobenzene at higher temperatures (250-260 °C), the resulting products are molecular ribbons composed of two twisted aromatic systems fused to a heteropentahelicene (19, 20, and 22). These molecules are representatives of a new class of chiral polycyclic aromatic compounds, the "hairpin furans". Interestingly, reheating a dimethoxy-substituted giant biaryl (e.g., 21) in nitrobenzene at 260 °C does not yield the corresponding hairpin furan (22), and mechanistic studies indicate that some intermediate or byproduct of the synthesis of the giant biaryls is a reagent or catalyst necessary for the conversion of the dimethoxybiaryl to the furan.

  3. KEPLER RAPIDLY ROTATING GIANT STARS

    SciTech Connect

    Costa, A. D.; Martins, B. L. Canto; Bravo, J. P.; Paz-Chinchón, F.; Chagas, M. L. das; Leão, I. C.; Oliveira, G. Pereira de; Silva, R. Rodrigues da; Roque, S.; Oliveira, L. L. A. de; Silva, D. Freire da; De Medeiros, J. R.

    2015-07-10

    Rapidly rotating giant stars are relatively rare and may represent important stages of stellar evolution, resulting from stellar coalescence of close binary systems or accretion of substellar companions by their hosting stars. In the present Letter, we report 17 giant stars observed in the scope of the Kepler space mission exhibiting rapid rotation behavior. For the first time, the abnormal rotational behavior for this puzzling family of stars is revealed by direct measurements of rotation, namely from photometric rotation period, exhibiting a very short rotation period with values ranging from 13 to 55 days. This finding points to remarkable surface rotation rates, up to 18 times the rotation of the Sun. These giants are combined with six others recently listed in the literature for mid-infrared (IR) diagnostics based on Wide-field Infrared Survey Explorer information, from which a trend for an IR excess is revealed for at least one-half of the stars, but at a level far lower than the dust excess emission shown by planet-bearing main-sequence stars.

  4. Observed Properties of Giant Cells

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.; Upton, Lisa; Colegrove, Owen

    2014-01-01

    The existence of Giant Cells has been suggested by both theory and observation for over 45 years. We have tracked the motions of supergranules in SDO/HMI Doppler velocity data and find larger (Giant Cell) flows that persist for months. The flows in these cells are clockwise around centers of divergence in the north and counter-clockwise in the south. Equatorward flows are correlated with prograde flows - giving the transport of angular momentum toward the equator that is needed to maintain the Sun's rapid equatorial rotation. The cells are most pronounced at mid- and high-latitudes where they exhibit the rotation rates representative of those latitudes. These are clearly large, long-lived, cellular features, with the dynamical characteristics expected from the effects of the Sun's rotation, but the shapes of the cells are not well represented in numerical models. While the Giant Cell flow velocities are small (<10 m/s), their long lifetimes should nonetheless substantially impact the transport of magnetic flux in the Sun's near surface layers.

  5. Electrodynamics in Giant Planet Atmospheres

    NASA Astrophysics Data System (ADS)

    Koskinen, T.; Yelle, R. V.; Lavvas, P.; Cho, J.

    2014-12-01

    The atmospheres of close-in extrasolar giant planets such as HD209458b are strongly ionized by the UV flux of their host stars. We show that photoionization on such planets creates a dayside ionosphere that extends from the thermosphere to the 100 mbar level. The resulting peak electron density near the 1 mbar level is higher than that encountered in any planetary ionosphere of the solar system, and the model conductivity is in fact comparable to the atmospheres of Sun-like stars. As a result, the momentum and energy balance in the upper atmosphere of HD209458b and similar planets can be strongly affected by ion drag and resistive heating arising from wind-driven electrodynamics. Despite much weaker ionization, electrodynamics is nevertheless also important on the giant planets of the solar system. We use a generic framework to constrain the conductivity regimes on close-in extrasolar planets, and compare the results with conductivites based on the same approach for Jupiter and Saturn. By using a generalized Ohm's law and assumed magnetic fields, we then demonstrate the basic effects of wind-driven ion drag in giant planet atmospheres. Our results show that ion drag is often significant in the upper atmosphere where it can also substantially alter the energy budget through resistive heating.

  6. Development of primary cell cultures using hemocytes and phagocytic tissue cells of Locusta migratoria: an application for locust immunity studies.

    PubMed

    Duressa, Tewodros Firdissa; Huybrechts, Roger

    2016-01-01

    Insect cell cultures played central roles in unraveling many insect physiological and immunological processes. Regardless, despite imminent needs, insect cell lines were developed primarily from Dipteran and Lepidopteran orders, leaving many important insects such as Orthopteran locusts under-represented. Besides the lack of cell lines, the slow progress in development of in vitro techniques is attributed to poor communications between different laboratories regarding optimized primary cell cultures. Therefore, we report here about methods developed for primary cell culture of Locusta migratoria hemocyte and phagocytic tissue cells by which we could maintain viable hemocytes in vitro for over 5 d and phagocytic tissue cells for over 12 d. 2-Mercaptoethanol and phenyl-thiourea supplements in Grace's medium together with addition of fetal bovine serum 30 min after cell seeding resulted in a successful setup of the primary cell cultures and a week-long survival of the hemocytes and phagocytic tissue cells in vitro.

  7. The hind wing of the desert locust (Schistocerca gregaria Forskål). I. Functional morphology and mode of operation.

    PubMed

    Wootton, R J; Evans, K E; Herbert, R; Smith, C W

    2000-10-01

    Detailed morphological investigation, mechanical testing and high-speed cinematography and stroboscopic examination of desert locusts, Schistocerca gregaria, in flight show that their hind wings are adapted to deform cyclically and automatically through the wing stroke and that the deformations are subtly dependent on the wings' structure: their shape, venation and vein design and the local properties of the membrane. The insects predominantly fly fast forwards, generating most force on the downstroke, and the hind wings generate extra lift by peeling apart at the beginning of the downstroke and by developing a cambered section during the stroke's translation phase through the 'umbrella effect' - an automatic consequence of the active extension of the wings' expanded posterior fan. Bending experiments indicate that most of the hind wing is more rigid to forces from below than from above and demonstrate that the membrane acts as a stressed skin to stiffen the structure.

  8. Impact of purification and fractionation process on the chemical structure and physical properties of locust bean gum.

    PubMed

    Sébastien, Gillet; Christophe, Blecker; Mario, Aguedo; Pascal, Laurent; Michel, Paquot; Aurore, Richel

    2014-08-08

    Crude locust bean gum (CLBG) was purified and fractionated into two parts: the first was obtained by solubilization in water at 25°C (GM25) and the second consisted in a further extraction at 80°C on the residual impoverished fraction (GM80). The complete structural characterization has shown that GM80 possessed relatively longer chain lengths than GM25, a slightly lower degree of galactose substitution and a somewhat sharper galactosyl distribution in substituted and unsubstituted regions. A physical behavior analysis was carried out on solubilization kinetics, viscosity, viscoelasticity and formation of associated gels with xanthan or carrageenan. The average structure of GM80 generated larger intra-chain, inter-chain and inter-molecular interactions, resulting in the appearance of a stronger network. Small structural differences therefore generated very different physical behaviors. This study thus allowed to establish, in a precise and complete manner, fractionation-purification-structure-function relationships of galactomannans extracted from carob.

  9. Developmental expression of cell recognition molecules in the mushroom body and antennal lobe of the locust Locusta migratoria.

    PubMed

    Eickhoff, René; Bicker, Gerd

    2012-06-15

    We examined the development of olfactory neuropils in the hemimetabolous insect Locusta migratoria with an emphasis on the mushroom bodies, protocerebral integration centers implicated in memory formation. Using a marker of the cyclic adenosine monophosphate (cAMP) signaling cascade and lipophilic dye labeling, we obtained new insights into mushroom body organization by resolving previously unrecognized accessory lobelets arising from Class III Kenyon cells. We utilized antibodies against axonal guidance cues, such as the cell surface glycoproteins Semaphorin 1a (Sema 1a) and Fasciclin I (Fas I), as embryonic markers to compile a comprehensive atlas of mushroom body development. During embryogenesis, all neuropils of the olfactory pathway transiently expressed Sema 1a. The immunoreactivity was particularly strong in developing mushroom bodies. During late embryonic stages, Sema 1a expression in the mushroom bodies became restricted to a subset of Kenyon cells in the core region of the peduncle. Sema 1a was differentially sorted to the Kenyon cell axons and absent in the dendrites. In contrast to Drosophila, locust mushroom bodies and antennal lobes expressed Fas I, but not Fas II. While Fas I immunoreactivity was widely distributed in the midbrain during embryogenesis, labeling persisted into adulthood only in the mushroom bodies and antennal lobes. Kenyon cells proliferated throughout the larval stages. Their neurites retained the embryonic expression pattern of Sema 1a and Fas I, suggesting a role for these molecules in developmental mushroom body plasticity. Our study serves as an initial step toward functional analyses of Sema 1a and Fas I expression during locust mushroom body formation.

  10. Scaling of resting and maximum hopping metabolic rate throughout the life cycle of the locust Locusta migratoria.

    PubMed

    Snelling, Edward P; Seymour, Roger S; Matthews, Philip G D; Runciman, Sue; White, Craig R

    2011-10-01

    The hemimetabolous migratory locust Locusta migratoria progresses through five instars to the adult, increasing in size from 0.02 to 0.95 g, a 45-fold change. Hopping locomotion occurs at all life stages and is supported by aerobic metabolism and provision of oxygen through the tracheal system. This allometric study investigates the effect of body mass (Mb) on oxygen consumption rate (MO2, μmol h(-1)) to establish resting metabolic rate (MRO2), maximum metabolic rate during hopping (MMO2) and maximum metabolic rate of the hopping muscles (MMO2,hop) in first instar, third instar, fifth instar and adult locusts. Oxygen consumption rates increased throughout development according to the allometric equations MRO2=30.1Mb(0.83±0.02), MMO2=155Mb(1.01±0.02), MMO2,hop=120Mb(1.07±0.02) and, if adults are excluded, MMO2,juv=136Mb(0.97±0.02) and MMO2,juv,hop=103Mb(1.02±0.02). Increasing body mass by 20-45% with attached weights did not increase mass-specific MMO2 significantly at any life stage, although mean mass-specific hopping MO2 was slightly higher (ca. 8%) when juvenile data were pooled. The allometric exponents for all measures of metabolic rate are much greater than 0.75, and therefore do not support West, Brown and Enquist’s optimised fractal network model, which predicts that metabolism scales with a 3⁄4-power exponent owing to limitations in the rate at which resources can be transported within the body.

  11. Identification and characterization of a gene encoding a UBX domain-containing protein in the migratory locust, Locusta migratoria manilensis.

    PubMed

    He, Zheng-Bo; Xie, Yu; Si, Feng-Ling; Chen, Bin

    2013-08-01

    Ubiquitin regulatory X (UBX) domain-containing proteins are believed to function as cofactors for p97/CDC48, an adenosine triphosphatase shown to be involved in multiple cellular processes. In the present study, a full-length complementary DNA (cDNA) of UBX domain-containing gene, termed LmUBX1, was cloned from Locusta migratoria manilensis and characterized, using random amplification of cDNA ends polymerase chain reaction (RACE PCR), sequence analysis and quantitative real-time PCR. LmUBX1, 1 600 bp in length, is predicted to encode a 446-amino acid protein with a predicted molecular weight of 51.18 kDa that contains a central PUB domain and a carboxy-terminal UBX domain. Homology analysis revealed that LmUBX1 has higher similarity to the known UBX domain-containing proteins from insects than from other species. Moreover, based on sequence characteristics and phylogenetic relationships, it is suggested that LmUBX1 can be classified into the UBXD1 subfamily. Expression analysis founded that LmUBX1 exhibited significant expression variations at different developmental stages and in different tissues, suggesting that the expression of LmUBX1 was highly regulated. Interestingly, its messenger RNA transcript was more abundant in ovary and testis than in other tissues examined, suggesting that it may have more important roles in the reproductive system. In addition, LmUBX1 was differentially expressed in gregarious and solitary locusts and was significantly up-regulated in third and fifth instars of gregarious locusts, implying that LmUBX1 was also likely involved in the phase polyphenisms in L. migratoria manilensis. To our knowledge, this is the first report of cloning of a full-length cDNA of UBX domain-containing gene from L. migratoria manilensis.

  12. Topographic organization and possible function of the posterior optic tubercles in the brain of the desert locust Schistocerca gregaria.

    PubMed

    Beetz, M Jerome; El Jundi, Basil; Heinze, Stanley; Homberg, Uwe

    2015-08-01

    Migrating desert locusts, Schistocerca gregaria, are able to use the skylight polarization pattern for navigation. They detect polarized light with a specialized dorsal rim area in their compound eye. After multistage processing, polarization signals are transferred to the central complex, a midline-spanning brain area involved in locomotor control. Polarization-sensitive tangential neurons (TB-neurons) of the protocerebral bridge, a part of the central complex, give rise to a topographic arrangement of preferred polarization angles in the bridge, suggesting that the central complex acts as an internal sky compass. TB-neurons connect the protocerebral bridge with two adjacent brain areas, the posterior optic tubercles. To analyze the polarotopic organization of the central complex further, we investigated the number and morphologies of TB-neurons and the presence and colocalization of three neuroactive substances in these neurons. Triple immunostaining with antisera against Diploptera punctata allatostatin (Dip-AST), Manduca sexta allatotropin (Mas-AT), and serotonin (5HT) raised in the same host species revealed three spatially distinct TB-neuron clusters, each consisting of 10 neurons per hemisphere: cluster 1 and 3 showed Dip-AST/5HT immunostaining, whereas cluster 2 showed Dip-AST/Mas-AT immunostaining. Five subtypes of TB-neuron could be distinguished based on ramification patterns. Corresponding to ramification domains in the protocerebral bridge, the neurons invaded distinct but overlapping layers within the posterior optic tubercle. Similarly, neurons interconnecting the tubercles of the two hemispheres also targeted distinct layers of these neuropils. From these data we propose a neuronal circuit that may be suited to stabilize the internal sky compass in the central complex of the locust.

  13. Inulinase production by Geotrichum candidum OC-7 using migratory locusts as a new substrate and optimization process with Taguchi DOE.

    PubMed

    Canli, Ozden; Tasar, Gani Erhan; Taskin, Mesut

    2013-09-01

    Utilization of migratory locusts (Locusta migratoria) as a main substrate due to its high protein content for inulinase (2,1-β-d-fructan fructanohydrolase) production by Geotrichum candidum OC-7 was investigated in this study. To optimize fermentation conditions, four influential factors (locust powder (LP) concentration, sucrose concentration, pH and fermentation time) at three levels were investigated using Taguchi orthogonal array (OA) design of experiment (DOE). Inulinase yield obtained from the designed experiments with regard to Taguchi L9 OA was processed with Minitab 15 software at 'larger is better' as quality character. The results showed that optimal fermentation conditions determined as LP 30 g/l, sucrose 20 g/l, pH 6.0 and time 48 h. Maximum inulinase activity was recorded as 30.12 U/ml, which was closer to the predicted value (30.56 U/ml). To verify the results, analysis of variance test was employed. LP had the greatest contribution (71.96%) among the other factors. Sucrose had lower contribution (13.96%) than LP. This result demonstrated that LP had a strong effect on inulinase activity and can be used for enzyme production. Taguchi DOE application enhanced enzyme activity to about 3.05-fold versus unoptimized condition and 2.34-fold versus control medium. Consequently, higher inulinase production can be achieved by the utilization of an edible insect material as an alternative substrate and Taguchi DOE presents suitable optimization method for biotechnological process.

  14. Rapid cold hardening improves recovery of ion homeostasis and chill coma recovery time in the migratory locust, Locusta migratoria.

    PubMed

    Findsen, Anders; Andersen, Jonas Lembcke; Calderon, Sofia; Overgaard, Johannes

    2013-05-01

    Chill tolerance of insects is defined as the ability to tolerate low temperature under circumstances not involving freezing of intracellular or extracellular fluids. For many insects chill tolerance is crucial for their ability to persist in cold environments and mounting evidence indicates that chill tolerance is associated with the ability to maintain ion and water homeostasis, thereby ensuring muscular function and preventing chill injury at low temperature. The present study describes the relationship between muscle and haemolymph ion homeostasis and time to regain posture following cold shock (CS, 2 h at -4°C) in the chill-susceptible locust Locusta migratoria. This relationship was examined in animals with and without a prior rapid cold-hardening treatment (RCH, 2 h at 0°C) to investigate the physiological underpinnings of RCH. CS elicited a doubling of haemolymph [K(+)] and this disturbance was greater in locusts pre-exposed to RCH. Recovery of ion homeostasis was, however, markedly faster in RCH-treated animals, which correlated well with whole-organism performance as hardened individuals regained posture faster than non-hardened individuals following CS. The present study indicates that loss and recovery of muscular function are associated with the resting membrane potential of excitable membranes as attested by the changes in the equilibrium potential for K(+) (EK) following CS. Both hardened and non-hardened animals regained movement once K(+) homeostasis had recovered to a fixed level (EK≈-41 mV). RCH is therefore not associated with altered sensitivity to ion disturbance but instead is correlated to a faster recovery of haemolymph [K(+)].

  15. Two types of albino mutants in desert and migratory locusts are caused by gene defects in the same signaling pathway.

    PubMed

    Sugahara, Ryohei; Tanaka, Seiji; Jouraku, Akiya; Shiotsuki, Takahiro

    2017-04-15

    Albinism is caused by mutations in the genes involved in melanin production. Albino nymphs of Locusta migratoria and Schistocerca gregaria reared under crowded conditions are uniformly creamy-white in color. However, nothing is known about the molecular mechanisms underlying this phenomenon in locusts. The albino strain of L. migratoria is known to lack the dark-color-inducing neuropeptide corazonin (Crz). In this study, we report that this albino strain has a 10-base-pair deletion in the gene LmCRZ, which encodes Crz. This mutation was found to cause a frame-shift, resulting in a null mutation in Crz. On the other hand, the albino strain of S. gregaria is known to have an intact Crz. This strain was found to possess a single-nucleotide substitution in the middle of the Crz receptor-encoding gene, SgCRZR, which caused a nonsense mutation, resulting in a truncated receptor. Silencing of SgCRZR in wild-type S. gregaria nymphs greatly reduced the area and intensity of their black patterning, suggesting that the functional defect of SgCRZR likely causes the albinism. The expression level of SgCRZR in the albino S. gregaria was comparable to that in the wild type. Unlike the wild type, the albino strain of this locust did not show a phase-dependent shift in a morphometric trait controlled by Crz. From these results, we conclude that the mutations in LmCRZ and SgCRZR are responsible for the albinism in L. migratoria and S. gregaria, respectively, indicating that the two types of albinism are caused by different genetic defects in the same Crz signaling pathway.

  16. Nitric oxide: a co-modulator of efferent peptidergic neurosecretory cells including a unique octopaminergic neurone innervating locust heart.

    PubMed

    Bullerjahn, Alexander; Mentel, Tim; Pflüger, Hans-Joachim; Stevenson, Paul A

    2006-08-01

    Our findings suggest that nitric oxide (NO) acts as peripheral neuromodulator in locusts, in which it is commonly co-localized with RF-like peptide in neurosecretory cells. We also present the first evidence for NO as a cardio-regulator in insects. Putative NO-producing neurones were detected in locust pre-genital free abdominal ganglia by NADPH-diaphorase histochemistry and with an antibody against NO synthase (NOS). With both methods, we identified the same 14 somata in each examined ganglion: two dorsal posterior midline somata; six ventral posterior midline somata; and three pairs of lateral somata. A combination of NOS-detection methods with nerve tracing and transmitter immunocytochemistry revealed that at least 12 of these cells were efferent, of which four were identified as peptidergic neurosecretory cells with an antiserum detecting RFamide-like peptides. One of the latter was unequivocally identified as an octopaminergic dorsal unpaired median (DUM) neurone, which specifically projected to the heart ("DUM-heart"). Its peripheral projections revealed by axon tracing appeared as a meshwork of varicose endings encapsulating the heart. NOS-like immunoreactive profiles were found in the heart nerve. NO donors caused a dose-dependent increase in heart rate. This cardio-excitatory effect was negatively correlated to resting heart rate and seemed to be dependent on the physiological state of the animal. Hence, NO released from neurones such as the rhythmically active DUM-heart might exert continuous control over the heart. Possible mechanisms for the actions of NO on the heart and interactions with other neuromodulators co-localized in the DUM-heart neurone (octopamine, taurine, RF-amide-like peptide) are discussed.

  17. Bilateral flight muscle activity predicts wing kinematics and 3-dimensional body orientation of locusts responding to looming objects.

    PubMed

    McMillan, Glyn A; Loessin, Vicky; Gray, John R

    2013-09-01

    We placed locusts in a wind tunnel using a loose tether design that allowed for motion in all three rotational degrees of freedom during presentation of a computer-generated looming disc. High-speed video allowed us to extract wing kinematics, abdomen position and 3-dimensional body orientation. Concurrent electromyographic (EMG) recordings monitored bilateral activity from the first basalar depressor muscles (m97) of the forewings, which are implicated in flight steering. Behavioural responses to a looming disc included cessation of flight (wings folded over the body), glides and active steering during sustained flight in addition to a decrease and increase in wingbeat frequency prior to and during, respectively, an evasive turn. Active steering involved shifts in bilateral m97 timing, wing asymmetries and whole-body rotations in the yaw (ψ), pitch (χ) and roll (η) planes. Changes in abdomen position and hindwing asymmetries occurred after turns were initiated. Forewing asymmetry and changes in η were most highly correlated with m97 spike latency. Correlations also increased as the disc approached, peaking prior to collision. On the inside of a turn, m97 spikes occurred earlier relative to forewing stroke reversal and bilateral timing corresponded to forewing asymmetry as well as changes in whole-body rotation. Double spikes in each m97 occurred most frequently at or immediately prior to the time the locusts turned, suggesting a behavioural significance. These data provide information on mechanisms underlying 3-dimensional flight manoeuvres and will be used to drive a closed loop flight simulator to study responses of motion-sensitive visual neurons during production of realistic behaviours.

  18. Guiding the Giant

    NASA Astrophysics Data System (ADS)

    1998-08-01

    New ESO Survey Provides Targets for the VLT Giant astronomical telescopes like the ESO Very Large Telescope (VLT) must be used efficiently. Observing time is expensive and there are long waiting lines of excellent research programmes. Thus the work at the telescope must be very well prepared and optimized as much as possible - mistakes should be avoided and no time lost! Astronomers working with the new 8-m class optical/infrared telescopes must base their observations on detailed lists of suitable target objects if they want to perform cutting-edge science. This is particularly true for research programmes that depend on observations of large samples of comparatively rare, distant objects. This type of work requires that extensive catalogues of such objects must be prepared in advance. One such major catalogue - that will serve as a very useful basis for future VLT observations - has just become available from the new ESO Imaging Survey (EIS). The Need for Sky Surveys Astronomers have since long recognized the need to carry out preparatory observations with other telescopes in order to "guide" large telescopes. To this end, surveys of smaller or larger parts of the sky have been performed by wide-field telescopes, paving the way for subsequent work at the limits of the largest available ground-based telescopes. For instance, a complete photographic survey of the sourthern sky (declination < -17.5°) was carried out in the 1970's with the ESO 1-metre Schmidt Telescope in support of the work at the 3.6-m telescope at the ESO La Silla observatory. However, while until recently most observational programmes could rely on samples of objects found on photographic plates, this is no longer possible. New image surveys must match the fainter limiting magnitudes reached by the new and larger telescopes. Modern digital, multi-colour, deep imaging surveys have thus become an indispensable complement to the 8-m telescopes. The new generation of imaging surveys will, without

  19. Cabergoline Treatment in Invasive Giant Prolactinoma

    PubMed Central

    Alsubaie, Sadeem; Almalki, Mussa H

    2014-01-01

    Patients with invasive giant prolactinoma suffer from a constellation of symptoms including headache, blurred vision, lethargy, and sexual dysfunction. Cabergoline, a potent dopamine agonist, is a known medication prescribed for the treatment of invasive giant prolactinoma. Here, we report a case of invasive giant prolactinoma in a 52-year-old Saudi male with dramatic response to cabergoline treatment clinically, biochemically, and radiologically. PMID:25002819

  20. Giant-cell granuloma of the axis.

    PubMed

    González-Martínez, Emilio; Santamarta, David; Lomas-García, Jesús; Ibáñez-Plágaro, F Javier; Fernández-Fernández, J Javier; Ariño, Teresa Ribas; García-Cosamalón, José

    2012-02-01

    Giant-cell granuloma is a benign and nonneoplastic lesion with an expansive and locally destructive behavior. It typically involves the mandible and the maxilla. Only 1 case arising from the odontoid process of the axis has been reported previously. The authors report on a 64-year-old man with a giant-cell granuloma of the axis. They review this uncommon entity, emphasizing the complexity of differentiating between this lesion and other giant-cell tumors.

  1. Red giants: then and now

    NASA Astrophysics Data System (ADS)

    Faulkner, John

    Fred Hoyle's work on the structure and evolution of red giants, particularly his pathbreaking contribution with Martin Schwarzschild (Hoyle and Schwarzschild 1955), is both lauded and critically assessed. In his later lectures and work with students in the early 1960s, Hoyle presented more physical ways of understanding some of the approximations used, and results obtained, in that seminal paper. Although later ideas by other investigators will be touched upon, Hoyle's viewpoint - that low-mass red giants are essentially white dwarfs with a serious mass-storage problem - is still extremely fruitful. Over the years, I have further developed his method of attack. Relatively recently, I have been able to deepen and broaden the approach, finally extending the theory to provide a unifying treatment of the structure of low-mass stars from the main sequence though both the red-giant and horizontal-branch phases of evolution. Many aspects of these stars that had remained puzzling, even mysterious, for decades have now fallen into place, and some questions have been answered that were not even posed before. With low-mass red giants as the simplest example, this recent work emphasizes that stars, in general, may have at least two distinct but very important centres: (I) a geometrical centre, and (II) a separate nuclear centre, residing in a shell outside a zero-luminosity dense core for example. This two-centre perspective leads to an explicit, analytical, asymptotic theory of low-mass red-giant structure. It enables one to appreciate that the problem of understanding why such stars become red giants is one of anticipating a remarkable yet natural structural bifurcation that occurs in them. This bifurcation occurs because of a combination of known and understandable facts just summarized namely that, following central hydrogen exhaustion, a thin nuclear-burning shell does develop outside a more-or-less dense core. In the resulting theory, both ρsh/ρolinec and

  2. Synergistic gelation of xanthan gum with locust bean gum: a rheological investigation.

    PubMed

    Copetti, G; Grassi, M; Lapasin, R; Pricl, S

    1997-12-01

    Many industrial products often include in their formulation more than one polysaccharide to achieve the desired properties during and after processing. Many such mixed systems behave as would be expected from the known properties of the individual polymers. In others, however, their properties are superior to those of either component alone, or may be qualitatively different. In many polysaccharide systems, the combination of a gelling polymer with a nongelling one gives rise to strong synergistic effects, as a consequence of interaction among different chain polymers and formation of mixed junction zones. Probably, the most exploited mixed gels, especially by the food industry, are those involving the microbial polysaccharide xanthan gum (XG) and the plant galactomannans, like locust bean gum (LBG). Concentrated aqueous systems of LBG and XG display quite different rheological properties: the former show the behaviour typical of hyperentangled macromolecular solutions, whereas the flow and viscoelastic properties of XG systems correspond to those of tenuous, weak-gel networks. Interestingly, when mixed together these macromolecules interact to form a firm, thermoreversible gel with synergistic effects. In the present paper we report the results of a thorough investigation of both polymer concentration and temperature effects on the rheological properties of mixed LBG-XG systems in 20 mM KCl under continuous and oscillatory flow conditions. Under continuous shear at 25 degrees C, pure LBG shows the flow properties of a macromolecular solution, with a shear-thinning behaviour and a Newtonian region at low shear rates, whereas the rheological behaviour of XG and all LX mixed systems is that typical of weak-gels. Furthermore, in the mixed systems the viscosity values do not increase monotonically with increasing xanthan concentration, but the synergistic effect has a maximum in accordance with the XG:LBG ratio 1:1. As the temperature is increased from 25 degrees C to

  3. ORIGIN OF LITHIUM ENRICHMENT IN K GIANTS

    SciTech Connect

    Kumar, Yerra Bharat; Reddy, Bacham E.; Lambert, David L.

    2011-03-20

    In this Letter, we report on a low-resolution spectroscopic survey for Li-rich K giants among 2000 low-mass (M {<=} 3 M{sub sun}) giants spanning the luminosity range from below to above the luminosity of the clump. Fifteen new Li-rich giants including four super Li-rich K giants (log {epsilon}(Li) {>=}3.2) were discovered. A significant finding is that there is a concentration of Li-rich K giants at the luminosity of the clump or red horizontal branch. This new finding is partly a consequence of the fact that our low-resolution survey is the first large survey to include giants well below and above the red giant branch (RGB) bump and clump locations in the H-R diagram. Origin of the lithium enrichment may be plausibly attributed to the conversion of {sup 3}He via {sup 7}Be to {sup 7}Li by the Cameron-Fowler mechanism but the location for the onset of the conversion is uncertain. Two possible opportunities to effect this conversion are discussed: the bump in the first ascent of the RGB and the He-core flash at the tip of the RGB. The finite luminosity spread of the Li-rich giants serves to reject the idea that Li enhancement is, in general, a consequence of a giant swallowing a large planet.

  4. Speciation and phylogeography of giant petrels Macronectes.

    PubMed

    Techow, N M S M; O'Ryan, C; Phillips, R A; Gales, R; Marin, M; Patterson-Fraser, D; Quintana, F; Ritz, M S; Thompson, D R; Wanless, R M; Weimerskirch, H; Ryan, P G

    2010-02-01

    We examine global phylogeography of the two forms of giant petrel Macronectes spp. Although previously considered to be a single taxon, and despite debate over the status of some populations and the existence of minimal genetic data (one mitochondrial cytochrome b sequence per form), the current consensus based on morphology is that there are two species, Northern Giant Petrel M. halli and Southern Giant Petrel M. giganteus. This study examined genetic variation at cytochrome b as well as six microsatellite loci in giant petrels from 22 islands, representing most island groups at which the two species breed. Both markers support separate species status, although sequence divergence in cytochrome b was only 0.42% (corrected). Divergence was estimated to have occurred approximately 0.2mya, but with some colonies apparently separated for longer (up to 0.5 my). Three clades were found within giant petrels, which separated approximately 0.7mya, with the Southern Giant Petrel paraphyletic to a monophyletic Northern Giant Petrel. There was evidence of past fragmentation during the Pleistocene, with subsequent secondary contact within Southern Giant Petrels. The analysis also suggested a period of past population expansion that corresponded roughly to the timing of speciation and the separation of an ancestral giant petrel population from the fulmar Fulmarus clade. Copyright (c) 2009 Elsevier Inc. All rights reserved.

  5. Spontaneous thrombosis in giant intracranial aneurysms.

    PubMed Central

    Whittle, I R; Dorsch, N W; Besser, M

    1982-01-01

    Twelve patients in a series of 22 with giant intracranial aneurysms demonstrated neuroradiological features of partial or total spontaneous intra-aneurysmal thrombosis. The presence of this intra-aneurysmal clot significantly altered the computed tomographic appearance of the giant aneurysm. Massive intra-aneurysmal thrombosis did not protect against subarachnoid haemorrhage and the likelihood of rupture of a clot containing giant aneurysm was not significantly different from that of a non-thrombosed giant aneurysm. Although parent artery occlusion from a thrombosed giant aneurysm, and massive aneurysmal thrombosis leading to the formation of giant serpentine aneurysm were documented, these are rare epiphenomena. The risk of embolisation from a partially thrombosed giant aneurysm, which was documented in one case, would appear to be greater than that from a non-thrombosed giant aneurysm. The findings in this series, and a review of literature, suggest that the presence of intra-aneurysmal clot in giant intracranial aneurysms has little prognostic significance and does not alter the management or outcome after treatment. Images PMID:7175528

  6. Pasting properties of Tamarind (Tamarindus indica) kernel powder in the presence of Xanthan, Carboxymethylcellulose and Locust bean gum in comparison to Rice and Potato flour.

    PubMed

    Kaur, Maninder; Sandhu, Kawaljit Singh; Kaur, Jasmeen

    2013-08-01

    Effects of addition of different levels of gums (xanthan, carboxymethylcellulose and locust bean gum) on the pasting properties of tamarind kernel, potato and rice flour were studied by using Rapid Visco-Analyzer (RVA). Tamarind kernel powder (TKP) varied significantly (P < 0.05) from rice and potato flours with respect to its highest protein, ash and fat contents. The results of RVA analysis indicated that pasting properties of flour/gum mixtures were dependent upon the concentration and type of the gums. Peak, breakdown and final viscosity increased with increase in gum concentration in the flour/gum mixture, but the effect was more pronounced for rice and potato flour than for TKP which showed much lower viscosity responses to all of the gums. Among the three gums studied, the increase in viscosity was significantly higher with addition of locust bean gum followed by xanthan while the lowest was observed with carboxymethylcellulose.

  7. The hind wing of the desert locust (Schistocerca gregaria Forskål). III. A finite element analysis of a deployable structure.

    PubMed

    Herbert, R C; Young, P G; Smith, C W; Wootton, R J; Evans, K E

    2000-10-01

    Finite element analysis is used to model the automatic cambering of the locust hind wing during promotion: the umbrella effect. It was found that the model required a high degree of sophistication before replicating the deformations found in vivo. The model has been validated using experimental data and the deformations recorded both in vivo and ex vivo. It predicts that even slight modifications to the geometrical description used can lead to significant changes in the deformations observed in the anal fan. The model agrees with experimental data and produces deformations very close to those seen in free-flying locusts. The validated model may be used to investigate the varying geometries found in orthopteran anal fans and the stresses found throughout the wing when loaded.

  8. Warm Disks from Giant Impacts

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-10-01

    In the process of searching for exoplanetary systems, weve discovered tens of debris disks close around distant stars that are especially bright in infrared wavelengths. New research suggests that we might be looking at the late stages of terrestrial planet formation in these systems.Forming Terrestrial PlanetsAccording to the widely-accepted formation model for our solar-system, protoplanets the size of Mars formed within a protoplanetary disk around our Sun. Eventually, the depletion of the gas in the disk led the orbits of these protoplanets to become chaotically unstable. Finally, in the giant impact stage, many of the protoplanets collided with each other ultimately leading to the formation of the terrestrial planets and their moons as we know them today.If giant impact stages occur in exoplanetary systems, too leading to the formation of terrestrial exoplanets how would we detect this process? According to a study led by Hidenori Genda of the Tokyo Institute of Technology, we might be already be witnessing this stage in observations of warm debris disks around other stars. To test this, Genda and collaborators model giant impact stages and determine what we would expect to see from a system undergoing this violent evolution.Modeling CollisionsSnapshots of a giant impact in one of the authors simulations. The collision causes roughly 0.05 Earth masses of protoplanetary material to be ejected from the system. Click for a closer look! [Genda et al. 2015]The collaborators run a series of simulations evolving protoplanetary bodies in a solar system. The simulations begin 10 Myr into the lifetime of the solar system, i.e., after the gas from the protoplanetary disk has had time to be cleared and the protoplanetary orbits begin to destabilize. The simulations end when the protoplanets are done smashing into each other and have again settled into stable orbits, typically after ~100 Myr.The authors find that, over an average giant impact stage, the total amount of

  9. Organization of columnar inputs in the third optic ganglion of a highly visual crab.

    PubMed

    Bengochea, Mercedes; Berón de Astrada, Martín

    2014-01-01

    Motion information provides essential cues for a wide variety of animal behaviors such as mate, prey, or predator detection. In decapod crustaceans and pterygote insects, visual codification of object motion is associated with visual processing in the third optic neuropile, the lobula. In this neuropile, tangential neurons collect motion information from small field columnar neurons and relay it to the midbrain where behavioral responses would be finally shaped. In highly ordered structures, detailed knowledge of the neuroanatomy can give insight into their function. In spite of the relevance of the lobula in processing motion information, studies on the neuroarchitecture of this neuropile are scant. Here, by applying dextran-conjugated dyes in the second optic neuropile (the medulla) of the crab Neohelice, we mass stained the columnar neurons that convey visual information into the lobula. We found that the arborizations of these afferent columnar neurons lie at four main lobula depths. A detailed examination of serial optical sections of the lobula revealed that these input strata are composed of different number of substrata and that the strata are thicker in the centre of the neuropile. Finally, by staining the different lobula layers composed of tangential processes we combined the present characterization of lobula input strata with the previous characterization of the neuroarchitecture of the crab's lobula based on reduced-silver preparations. We found that the third lobula input stratum overlaps with the dendrites of lobula giant tangential neurons. This suggests that columnar neurons projecting from the medulla can directly provide visual input to the crab's lobula giant neurons.

  10. Nonlinearity in giant depolarizing potentials

    NASA Astrophysics Data System (ADS)

    Nakatani, Hironori; Khalilov, Ilgam; Gong, Pulin; van Leeuwen, Cees

    2003-12-01

    Synchronous population discharges in immature neurons, or giant depolarizing potentials (GDPs), are considered to have an important role in the development of the functional network in hippocampus and other neural tissue before or briefly after birth. Recently, theoretical models have emphasized the possible role of chaotic, nonlinear activity at circuit level in establishing functional connectivity in neural tissue. Combining these two hypotheses leads to the prediction that GDPs have chaotic characteristics. We tested nonlinearity in GDPs recorded from transverse hippocampal slices of neonatal Wistar rats. Our results provide evidence of nonlinearity in GDP activity at circuit level.

  11. Analysis of giant electrorheological fluids.

    PubMed

    Seo, Youngwook P; Seo, Yongsok

    2013-07-15

    The yield stress dependence on electric field strength for giant electrorheological (GER) fluids over the full range of electric fields was examined using Seo's scaling function which incorporated both the polarization and the conductivity models. If a proper scaling was applied to the yield stress data to collapse them onto a single curve, the Seo's scaling function could correctly fit the yield stress behavior of GER suspensions, even at very high electric field strengths. The model predictions were also compared with recently proposed Choi et al.'s model to allow a consideration of the universal framework of ER fluids. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Giant epignathus. A case report.

    PubMed

    Todd, D W; Votava, H J; Telander, R L; Shoemaker, C T

    1991-07-01

    We report the successful treatment of a 2.8 kg female infant born with a giant epignathus, and we present our current prenatal and neonatal recommendations for managing this problem. We recommend that the delivery be done by cesarean section, that an adjacent operating room be ready for the baby, and that a neonatologist, anesthesiologist, and pediatric surgeon be standing by. The term epignathus now commonly applies to a teratoma protruding from a newborn's mouth. The survival of these otherwise normal children has been very low. We discuss the perinatal, neonatal, and operative care necessary to improve survival, as evidenced by the case presented.

  13. Adaptive difference in daily timing of hatch in two locust species, Schistocerca gregaria and Locusta migratoria: the effects of thermocycles and phase polyphenism.

    PubMed

    Nishide, Yudai; Tanaka, Seiji; Saeki, Shinjiro

    2015-01-01

    This study examined the effects of temperature and phase polyphenism on egg hatching time in the desert locust, Schistocerca gregaria, and the migratory locust, Locusta migratoria. The two species exhibited differences and similarities in hatching behavior when exposed to different temperature conditions. In 12-h thermocycles of various temperatures, the S. gregaria eggs hatched during the cryoperiod (low temperature period), whereas L. migratoria eggs hatched during the thermoperiod (high temperature period). The eggs of both species hatched during the species-specific period of the thermoperiod in response to a temperature difference as small as 1 °C. Furthermore, the locusts adjusted hatching time to a new thermal environment that occurred shortly before the expected hatching time. In both species, the hatching of the eggs was synchronized to a specific time of the day, and two hatching peaks separated by approximately 1 day were observed at a constant temperature after the eggs were transferred from thermocycles 3 days before hatching. Eggs laid by gregarious females hatched earlier than those laid by solitarious females in S. gregaria but this difference was not observed in L. migratoria.

  14. Identification of LmUAP1 as a 20-hydroxyecdysone response gene in the chitin biosynthesis pathway from the migratory locust, Locusta migratoria.

    PubMed

    Liu, Xiao-Jian; Sun, Ya-Wen; Li, Da-Qi; Li, Sheng; Ma, En-Bo; Zhang, Jian-Zhen

    2016-10-03

    In Locusta migratoria, we found that two chitin biosynthesis genes, UDP N-acetylglucosamine pyrophosphorylase gene LmUAP1 and chitin synthase gene LmCHS1, are expressed mainly in the integument and are responsible for cuticle formation. However, whether these genes are regulated by 20-hydroxyecdysone (20E) is still largely unclear. Here, we showed the developmental expression pattern of LmUAP1, LmCHS1 and the corresponding 20E titer during the last instar nymph stage of locust. RNA interference (RNAi) directed toward a common region of the two isoforms of LmEcR (LmEcRcom) reduced the expression level of LmUAP1, while there was no difference in the expression of LmCHS1. Meantime, injection of 20E in vivo induced the expression of LmUAP1 but not LmCHS1. Further, we found injection-based RNAi of LmEcRcom resulted in 100% mortality. The locusts failed to molt with no apolysis, and maintained in the nymph stage until death. In conclusion, our preliminary results indicated that LmUAP1 in the chitin biosynthesis pathway is a 20E late-response gene and LmEcR plays an essential role in locust growth and development, which could be a good potential target for RNAi-based pest control.

  15. dsRNA uptake and persistence account for tissue-dependent susceptibility to RNA interference in the migratory locust, Locusta migratoria.

    PubMed

    Ren, D; Cai, Z; Song, J; Wu, Z; Zhou, S

    2014-04-01

    RNA interference (RNAi) by introducing double-stranded RNA (dsRNA) is a powerful approach to the analysis of gene function in insects; however, RNAi responses vary dramatically in different insect species and tissues, and the underlying mechanisms remain poorly understood. The migratory locust, a destructive insect pest and a hemimetabolic insect with panoistic ovaries, is considered to be a highly susceptible species to RNAi via dsRNA injection, but its ovary appears to be completely insensitive. In the present study, we showed that dsRNA persisted only briefly in locust haemolymph. The ovariole sheath was permeable to dsRNA, but injected dsRNA was not present in the follicle cells and oocytes. The lack of dsRNA uptake into the follicle cells and oocytes is likely to be the primary factor that contributes to the ineffective RNAi response in locust ovaries. These observations provide insights into tissue-dependent variability of RNAi and help in achieving successful gene silencing in insensitive tissues.

  16. The serotonergic system is involved in feeding inhibition by pymetrozine. Comparative studies on a locust (Locusta migratoria) and an aphid (Myzus persicae).

    PubMed

    Kaufmann, Liselotte; Schürmann, Franz; Yiallouros, Maria; Harrewijn, Paul; Kayser, Hartmut

    2004-08-01

    Pymetrozine inhibits feeding in aphids immediately after application without producing visible neurotoxic effects, as previously reported. In the present work, Locusta migratoria, though not a plant-sucking insect, was found to respond to pymetrozine by displaying unique symptoms, which were lifting and stretching of the hindlegs, in addition to inhibition of feeding. In locust, pymetrozine enhanced spontaneous spike discharge of the metathoracic and suboesophageal ganglia in situ at nanomolar concentrations. Similarly, pymetrozine increased the spontaneous rhythmic contractions of the isolated foregut with maximal effects also in the nanomolar range. The actions of pymetrozine were counteracted by biogenic amine receptor antagonists and mimicked by serotonin, not by dopamine and octopamine. Moreover, pymetrozine and serotonin strongly potentiated the effects of each other. Pymetrozine was inactive at all neurotransmitter receptors present on isolated locust neuronal somata, and at all other examined neuronal sites. In Myzus persicae, electrical penetration graph experiments revealed that serotonin, like pymetrozine, inhibited stylet penetration, and strongly enhanced the action of pymetrozine, comparable to the locust. Amine receptor antagonists were not specifically active in the aphid. We conclude from the present results that pymetrozine acts via a novel mechanism that is linked to the signalling pathway of serotonin.

  17. Proteomic analysis reveals that COP9 signalosome complex subunit 7A (CSN7A) is essential for the phase transition of migratory locust

    PubMed Central

    Tong, Xi-Wen; Chen, Bing; Huang, Li-Hua; Feng, Qi-Li; Kang, Le

    2015-01-01

    The migratory locust displays a reversible, density-dependent transition between the two phases of gregaria and solitaria. This phenomenon is a typical kind of behavior plasticity. Here, we report that COP9 signalosome complex subunit 7A (CSN7A) is involved in the regulation of locust phase transition. Firstly, 90 proteins were identified to express differentially between the two phases by quantitative proteomic analysis. Gregaria revealed higher levels in proteins related to structure formation, melanism and energy metabolism, whereas solitaria had more abundant proteins related to digestion, absorption and chemical sensing. Subsequently, ten proteins including CSN7A were found to reveal differential mRNA expression profiles between the two phases. The CSN7A had higher mRNA level in the gregaria as compared with the solitaria, and the mRNA amount in the gregaria decreased remarkably during the 32 h-isolation. However, the mRNA level in the solitaria kept constant during the crowding rearing. Finally and importantly, RNA interference of CSN7A in gregaria resulted in obvious phase transition towards solitaria within 24 h. It suggests that CSN7A plays an essential role in the transition of gregaria towards solitaria in the migratory locust. To our knowledge, it’s the first time to report the role of CSN in behavior plasticity of animals. PMID:26212173

  18. Long-term impact of municipal sewage irrigation on treated soil and black locust trees in a semi-arid suburban area of Iran.

    PubMed

    Tabari, Masoud; Salehi, Azadeh

    2009-01-01

    The effects of municipal sewage irrigation on the soil and black locust (Robinia pseudoacacia L.) tree were studied. For this purpose, two artificial black locust stands under irrigation of municipal sewage and well water were selected in south of Tehran, Iran. Data were collected using technique of systematic random sampling with 4 replicates in each stand. It was found that the growth of black locust tree, as indicated by diameter at breast height, total height, crown length, average crown diameter, basal area and volume, in sewage irrigation stand was much higher than that of well water irrigation stand (P < 0.01). Plant analysis indicated that concentrations of leaf nutrients (N, P, K, Ca, Mg, Na, Fe, Mn, Cu and Zn) were greater in sewage-irrigated trees, without toxicity to the minerals of tree leaf, than those of well waterirrigated trees, and positively correlated with their respective value in soil. Ni, Cr and Pb were not detected in leaf samples. Application of sewage resulted in a 1.5-fold increase in the concentrations of soil nutrients, Ni, Cr and Pb. Among these minerals only Pb and Ni in some soil samples exceeded the toxicity limit. The increase in pH, electrical conductivity (EC) and organic carbon of soil was also observed in sewage irrigation. Results confirm that besides the use as irrigation water, municipal sewages are also a potential source of plant nutrients. However, significant accumulation of heavy metals such as Pb and Ni in soil needs to be monitored.

  19. Synaptic connections of first-stage visual neurons in the locust Schistocerca gregaria extend evolution of tetrad synapses back 200 million years.

    PubMed

    Wernitznig, Stefan; Rind, Frances Claire; Pölt, Peter; Zankel, Armin; Pritz, Elisabeth; Kolb, Dagmar; Bock, Elisabeth; Leitinger, Gerd

    2015-02-01

    The small size of some insects, and the crystalline regularity of their eyes, have made them ideal for large-scale reconstructions of visual circuits. In phylogenetically recent muscomorph flies, like Drosophila, precisely coordinated output to different motion-processing pathways is delivered by photoreceptors (R cells), targeting four different postsynaptic cells at each synapse (tetrad). Tetrads were linked to the evolution of aerial agility. To reconstruct circuits for vision in the larger brain of a locust, a phylogenetically old, flying insect, we adapted serial block-face scanning electron microscopy (SBEM). Locust lamina monopolar cells, L1 and L2, were the main targets of the R cell pathway, L1 and L2 each fed a different circuit, only L1 providing feedback onto R cells. Unexpectedly, 40% of all locust R cell synapses onto both L1 and L2 were tetrads, revealing the emergence of tetrads in an arthropod group present 200 million years before muscomorph flies appeared, coinciding with the early evolution of flight.

  20. Macromodeling for analog design and robustness boosting in bio-inspired computing models

    NASA Astrophysics Data System (ADS)

    Cuadri, J.; Linan, G.; Roca, E.; Rodriguez-Vazquez, A.

    2005-06-01

    Setting specifications for the electronic implementation of biological neural-network-like vision systems on-chip is not straightforward, neither it is to simulate the resulting circuit. The structure of these systems leads to a netlist of more than 100.000 nodes for a small array of 100x150 pixels. Moreover, introducing an optical input in the low level simulation is nowadays not feasible with standard electrical simulation environments. Given that, to accomplish the task of integrating those systems in silicon to build compact, low power consuming, and reliable systems, a previous step in the standard analog electronic design flux should be introduced. Here a methodology to make the translation from the biological model to circuit-level specifications for electronic design is proposed. The purpose is to include non ideal effects as mismatching, noise, leakages, supply degradation, feedthrough, and temperature of operation in a high level description of the implementation, in order to accomplish behavioural simulations that require less computational effort and resources. A particular case study is presented, the analog electronic implementation of the locust"s Lobula Giant Movement Detector (LGMD), a neural structure that fires a collision alarm based on visual information. The final goal is a collision threat detection vision system on-chip for automotive applications.