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Sample records for aranha parawixia bistriata

  1. Bourgeois behavior and freeloading in the colonial orb web spider Parawixia bistriata (Araneae, Araneidae).

    PubMed

    Wenseleers, Tom; Bacon, Jonathan P; Alves, Denise A; Couvillon, Margaret J; Kärcher, Martin; Nascimento, Fabio S; Nogueira-Neto, Paulo; Ribeiro, Marcia; Robinson, Elva J H; Tofilski, Adam; Ratnieks, Francis L W

    2013-07-01

    Spiders of the tropical American colonial orb weaver Parawixia bistriata form a communal bivouac in daytime. At sunset, they leave the bivouac and construct individual, defended webs within a large, communally built scaffolding of permanent, thick silk lines between trees and bushes. Once spiders started building a web, they repelled other spiders walking on nearby scaffolding with a "bounce" behavior. In nearly all cases (93%), this resulted in the intruder leaving without a fight, akin to the "bourgeois strategy," in which residents win and intruders retreat without escalated contests. However, a few spiders (6.5%) did not build a web due to lack of available space. Webless spiders were less likely to leave when bounced (only 42% left) and instead attempted to "freeload," awaiting the capture of prey items in nearby webs. Our simple model shows that webless spiders should change their strategy from bourgeois to freeloading satellite as potential web sites become increasingly occupied.

  2. Biochemical and Functional Characterization of Parawixia bistriata Spider Venom with Potential Proteolytic and Larvicidal Activities

    PubMed Central

    Gimenez, Gizeli S.; Coutinho-Neto, Antonio; Kayano, Anderson M.; Simões-Silva, Rodrigo; Trindade, Frances; de Almeida e Silva, Alexandre; Marcussi, Silvana; da Silva, Saulo L.; Fernandes, Carla F. C.; Zuliani, Juliana P.; Calderon, Leonardo A.; Soares, Andreimar M.; Stábeli, Rodrigo G.

    2014-01-01

    Toxins purified from the venom of spiders have high potential to be studied pharmacologically and biochemically. These biomolecules may have biotechnological and therapeutic applications. This study aimed to evaluate the protein content of Parawixia bistriata venom and functionally characterize its proteins that have potential for biotechnological applications. The crude venom showed no phospholipase, hemorrhagic, or anti-Leishmania activities attesting to low genotoxicity and discrete antifungal activity for C. albicans. However the following activities were observed: anticoagulation, edema, myotoxicity and proteolysis on casein, azo-collagen, and fibrinogen. The chromatographic and electrophoretic profiles of the proteins revealed a predominance of acidic, neutral, and polar proteins, highlighting the presence of proteins with high molecular masses. Five fractions were collected using cation exchange chromatography, with the P4 fraction standing out as that of the highest purity. All fractions showed proteolytic activity. The crude venom and fractions P1, P2, and P3 showed larvicidal effects on A. aegypti. Fraction P4 showed the presence of a possible metalloprotease (60 kDa) that has high proteolytic activity on azo-collagen and was inhibited by EDTA. The results presented in this study demonstrate the presence of proteins in the venom of P. bistriata with potential for biotechnological applications. PMID:24895632

  3. Biochemical and functional characterization of Parawixia bistriata spider venom with potential proteolytic and larvicidal activities.

    PubMed

    Gimenez, Gizeli S; Coutinho-Neto, Antonio; Kayano, Anderson M; Simões-Silva, Rodrigo; Trindade, Frances; de Almeida e Silva, Alexandre; Marcussi, Silvana; da Silva, Saulo L; Fernandes, Carla F C; Zuliani, Juliana P; Calderon, Leonardo A; Soares, Andreimar M; Stábeli, Rodrigo G

    2014-01-01

    Toxins purified from the venom of spiders have high potential to be studied pharmacologically and biochemically. These biomolecules may have biotechnological and therapeutic applications. This study aimed to evaluate the protein content of Parawixia bistriata venom and functionally characterize its proteins that have potential for biotechnological applications. The crude venom showed no phospholipase, hemorrhagic, or anti-Leishmania activities attesting to low genotoxicity and discrete antifungal activity for C. albicans. However the following activities were observed: anticoagulation, edema, myotoxicity and proteolysis on casein, azo-collagen, and fibrinogen. The chromatographic and electrophoretic profiles of the proteins revealed a predominance of acidic, neutral, and polar proteins, highlighting the presence of proteins with high molecular masses. Five fractions were collected using cation exchange chromatography, with the P4 fraction standing out as that of the highest purity. All fractions showed proteolytic activity. The crude venom and fractions P1, P2, and P3 showed larvicidal effects on A. aegypti. Fraction P4 showed the presence of a possible metalloprotease (60 kDa) that has high proteolytic activity on azo-collagen and was inhibited by EDTA. The results presented in this study demonstrate the presence of proteins in the venom of P. bistriata with potential for biotechnological applications.

  4. Neurochemical characterization of a neuroprotective compound from Parawixia bistriata spider venom that inhibits synaptosomal uptake of GABA and glycine.

    PubMed

    Beleboni, Renê Oliveira; Guizzo, Renato; Fontana, Andréia Cristina Karklin; Pizzo, Andrea Baldocchi; Carolino, Ruither Oliveira Gomes; Gobbo-Neto, Leonardo; Lopes, Norberto Peporine; Coutinho-Netto, Joaquim; Dos Santos, Wagner Ferreira

    2006-06-01

    The major contribution of this work is the isolation of a neuroprotective compound referred to as 2-amino-5-ureidopentanamide (FrPbAII) (M(r) = 174) from Parawixia bistriata spider venom and an investigation of its mode of action. FrPbAII inhibits synaptosomal GABA uptake in a dose-dependent manner and probably does not act on Na(+), K(+), and Ca(2+) channels, GABA(B) receptors, or gamma-aminobutyrate:alpha-ketoglutarate aminotransferase enzyme; therefore, it is not directly dependent on these structures for its action. Direct increase of GABA release and reverse transport are also ruled out as mechanisms of FrPbAII activities as well as unspecific actions on pore membrane formation. Moreover, FrPbAII is selective for GABA and glycine transporters, having slight or no effect on monoamines or glutamate transporters. According to our experimental glaucoma data in rat retina, FrPbAII is able to cross the blood-retina barrier and promote effective protection of retinal layers submitted to ischemic conditions. These studies are of relevance by providing a better understanding of neurochemical mechanisms involved in brain function and for possible development of new neuropharmacological and therapeutic tools.

  5. Neuroprotective activity of parawixin 10, a compound isolated from Parawixia bistriata spider venom (Araneidae: Araneae) in rats undergoing intrahippocampal NMDA microinjection

    PubMed Central

    Fachim, Helene Aparecida; Mortari, Marcia Renata; Gobbo-Netto, Leonardo; dos Santos, Wagner Ferreira

    2015-01-01

    Background: Parawixia bistriata is a semi-colonial spider found mainly in southeastern of Brazil. Parawixin 10 (Pwx 10) a compound isolated from this spider venom has been demonstrated to act as neuroprotective in models of injury regulating the glutamatergic neurotransmission through glutamate transporters. Objectives: The aim of this work was to evaluate the neuroprotective effect of Pwx 10 in a rat model of excitotoxic brain injury by N-methyl-D-aspartate (NMDA) injection. Material and Methods: Male Wistar rats have been used, submitted to stereotaxic surgery for saline or NMDA microinjection into dorsal hippocampus. Two groups of animals were treated with Pwx 10. These treated groups received a daily injection of the Pwx 10 (2.5 mg/μL) in the right lateral ventricle into rats pretreated with NMDA, always at the same time, each one starting the treatment 1 h or 24 h. Nissl staining was performed for evaluating the extension and efficacy of the NMDA injury and the neuroprotective effect of Pwx 10. Results: The treatment with Pwx 10 showed neuroprotective effect, being most pronounced when the compound was administrated from 1 h after NMDA in all hippocampal subfields analyzed (CA1, CA3 and hilus). Conclusion: These results indicated that Pwx 10 may be a good template to develop therapeutic drugs for treating neurodegenerative diseases, reinforcing the importance of continuing studies on its effects in the central nervous system. PMID:26246735

  6. Molecular dynamics simulations of the minor ampullate spidroin modular amino acid sequence from Parawixia bistriatra: insights into silk tertiary structure and fibre formation.

    PubMed

    Murad, André M; Rech, Elíbio L

    2011-05-01

    Spider fibres are primarily composed of proteins that are secreted by specialised glands found in different groups of arthropods. Because of their unique mechanical characteristics, it is of great interest to understand how the influence of repetitive modules within the fibres affects the final protein structure. Because each fibre is composed of a diverse set of repeated modular sequences, the differences between fibres allow for their structural comparison and, thereby, their functional comparison. Herein, we present molecular dynamics simulations of partial sequences from minor ampullate Spidroin (MiSp) silk of the Brazilian species Parawixia bistriata. Our data show that the formation of β-sheet structures is directly related to the N-termini alignment of the modules. The N-terminal alignment gives rise to a high number of hydrogen bonds whose formation is driven by repeated alanine (Ala) sequences, which, in turn, lead to increased fibre strength. This increased fibre strength contributes significantly to the final tertiary structure of the silk.

  7. Parawixin2, a novel non-selective GABA uptake inhibitor from Parawixia bistriata spider venom, inhibits pentylenetetrazole-induced chemical kindling in rats.

    PubMed

    Gelfuso, Erica A; Liberato, José L; Cunha, Alexandra O S; Mortari, Márcia R; Beleboni, Renê O; Lopes, Norberto P; Dos Santos, Wagner F

    2013-05-24

    The aims of the present work were to investigate the effects of the repeated administration of Parawixin2 (2-amino-5-ureidopentanamide; formerly FrPbAII), a novel GABA and glycine uptake inhibitor, in rats submitted to PTZ-induced kindling. Wistar rats were randomly divided in groups (n=6-8) for different treatments. Systemic injections of PTZ were administered every 48 h in the dose of 33 mg/kg; i.p., that is sufficient to induce fully kindled seizures in saline i.c.v. treated rats in a short period of time (28 days). Treatments in two types of positive controls (diazepam - DZP and nipecotic acid - NA groups) consisted in daily systemic injections of DZP (2mg/kg; i.p.) or i.c.v. injections of NA (12 μg/μL), while in experimental groups in daily i.c.v. injections of different doses of Parawixin2 (0.15; 0.075; 0.015 μg/μL). Seizures were analyzed using the Lamberty & Klitgaard score and kindling was considered as established after at least three consecutive seizures of score 4 or 5. Cumulative seizure scores for each group were analyzed using repeated measures of ANOVA followed by Tukey test. PTZ induced 4 and 5-score seizures after 12 injections in saline treated rats, whereas daily injection of Parawixin2 inhibited the onset of seizures in a dose dependent manner. Also, the challenging administration of PTZ did not raise seizure score in animals treated with the highest dose of Parawixin2 or those treated with DZP or NA. These findings together with previous data from our laboratory show that Parawixin2 could be a useful probe to design new antiepileptic drugs.

  8. Cross-habitat variation in the phenology of a colonial spider: insights from a reciprocal transplant study.

    PubMed

    Campón, Florencia Fernández

    2010-03-01

    In species with widespread distribution, populations found in markedly different environments can show differences in developmental traits. This, in time, can have an effect on reproductive success. Sources of variation in developmental traits can be genetic or environmentally induced. I examined the relationship between environmental and genetic influences on juvenile development in populations of the colonial spider, Parawixia bistriata, located at sites with different moisture regimes and associated environmental variables (e.g., prey availability). It was expected that individuals from different populations would show differences in developmental traits and that those differences will be associated with lower reproductive success at dry sites. I recorded the phenology and developmental traits of native and transplanted individuals in the field and estimated reproductive success based on clutch size. Colonies from wet versus dry sites showed different phenologies, with individuals at dry sites maturing later. Transplant results suggest plasticity in instar duration caused by environmental effects. Despite differences in resources and spider phenology, clutch sizes of native dry and wet populations were similar. Transplanted individuals, however, were differentially affected. Transplants from wet to dry sites (WD) showed lower growth rates and smaller clutches, whereas transplants from dry to wet sites had larger clutch sizes than in native habitat. Delayed maturation and failure to reproduce in WD individuals is associated with a lower tendency to capture prey in groups and less aggressive interactions during prey capture. Thus, despite negative environmental effects on development, dry native individuals have evolved non-developmental traits that allow successful reproduction.

  9. Cross-habitat variation in the phenology of a colonial spider: insights from a reciprocal transplant study

    NASA Astrophysics Data System (ADS)

    Fernández Campón, Florencia

    2010-03-01

    In species with widespread distribution, populations found in markedly different environments can show differences in developmental traits. This, in time, can have an effect on reproductive success. Sources of variation in developmental traits can be genetic or environmentally induced. I examined the relationship between environmental and genetic influences on juvenile development in populations of the colonial spider, Parawixia bistriata, located at sites with different moisture regimes and associated environmental variables (e.g., prey availability). It was expected that individuals from different populations would show differences in developmental traits and that those differences will be associated with lower reproductive success at dry sites. I recorded the phenology and developmental traits of native and transplanted individuals in the field and estimated reproductive success based on clutch size. Colonies from wet versus dry sites showed different phenologies, with individuals at dry sites maturing later. Transplant results suggest plasticity in instar duration caused by environmental effects. Despite differences in resources and spider phenology, clutch sizes of native dry and wet populations were similar. Transplanted individuals, however, were differentially affected. Transplants from wet to dry sites (WD) showed lower growth rates and smaller clutches, whereas transplants from dry to wet sites had larger clutch sizes than in native habitat. Delayed maturation and failure to reproduce in WD individuals is associated with a lower tendency to capture prey in groups and less aggressive interactions during prey capture. Thus, despite negative environmental effects on development, dry native individuals have evolved non-developmental traits that allow successful reproduction.

  10. Disease Modifying Effects of the Spider Toxin Parawixin2 in the Experimental Epilepsy Model.

    PubMed

    Godoy, Lívea Dornela; Liberato, José Luiz; Celani, Marcus Vinícius Batista; Gobbo-Neto, Leonardo; Lopes, Norberto Peporine; Dos Santos, Wagner Ferreira

    2017-08-25

    (1) Background: Temporal lobe epilepsy (TLE) is the most common type of epilepsy in adults. It is also the one with the highest percentage of drug-resistance to the current available anti-epileptic drugs (AED). Additionaly, most antiepileptic drugs are only able to control seizures in epileptogenesis, but do not decrease the hippocampal neurodegenerative process. TLE patients have a reduced population of interneuronal cells, which express Parvalbumin (PV) proteins. This reduction is directly linked to seizure frequency and severity in the chronic period of epilepsy. There is therefore a need to seek new therapies with a disease-modifying profile, and with efficient antiepileptic and neuroprotective properties. Parawixin2, a compound isolated from the venom of the spider Parawixia bistriata, has been shown to inhibit GABA transporters (GAT) and to have acute anticonvulsant effects in rats. (2) Methods: In this work, we studied the effects of Parawixin2 and Tiagabine (an FDA- approved GAT inhibitor), and compared these effects in a TLE model. Rats were subjected to lithium-pilocarpine TLE model and the main features were evaluated over a chronic period including: (a) spontaneous recurrent seizures (SRS), (b) neuronal loss, and (c) PV cell density in different regions of the hippocampus (CA1, CA3, DG and Hilus). (3) Results: Parawixin2 treatment reduced SRS frequency whereas Tiagabine did not. We also found a significant reduction in neuronal loss in CA3 and in the hilus regions of the hippocampus, in animals treated with Parawixin2. Noteworthy, Parawixin2 significantly reversed PV cell loss observed particularly in DG layers. (4) Conclusions: Parawixin2 exerts a promising neuroprotective and anti-epileptic effect and has potential as a novel agent in drug design.

  11. Effects of Spider Venom Toxin PWTX-I (6-Hydroxytrypargine) on the Central Nervous System of Rats

    PubMed Central

    Cesar-Tognoli, Lilian M. M.; Salamoni, Simone D.; Tavares, Andrea A.; Elias, Carol F.; Costa, Jaderson C. Da; Bittencourt, Jackson C.; Palma, Mario S.

    2011-01-01

    The 6-hydroxytrypargine (6-HT) is an alkaloidal toxin of the group of tetrahydro-β-carbolines (THβC) isolated from the venom of the colonial spider Parawixia bistriata. These alkaloids are reversible inhibitors of the monoamine-oxidase enzyme (MAO), with hallucinogenic, tremorigenic and anxiolytic properties. The toxin 6-HT was the first THβC chemically reported in the venom of spiders; however, it was not functionally well characterized up to now. The action of 6-HT was investigated by intracerebroventricular (i.c.v.) and intravenous (i.v.) applications of the toxin in adult male Wistar rats, followed by the monitoring of the expression of fos-protein, combined with the use of double labeling immunehistochemistry protocols for the detection of some nervous receptors and enzymes related to the metabolism of neurotransmitters in the central nervous system (CNS). We also investigated the epileptiform activity in presence of this toxin. The assays were carried out in normal hippocampal neurons and also in a model of chronic epilepsy obtained by the use of neurons incubated in free-magnesium artificial cerebro-spinal fluid (ACSF). Trypargine, a well known THβC toxin, was used as standard compound for comparative purposes. Fos-immunoreactive cells (fos-ir) were observed in hypothalamic and thalamic areas, while the double-labeling identified nervous receptors of the sub-types rGlu2/3 and NMR1, and orexinergic neurons. The 6-HT was administrated by perfusion and ejection in “brain slices” of hippocampus, inducing epileptic activity after its administration; the toxin was not able to block the epileptogenic crisis observed in the chronic model of the epilepsy, suggesting that 6-HT did not block the overactive GluRs responsible for this epileptic activity. PMID:22069702

  12. Molecular determinants of transport stimulation of EAAT2 are located at interface between the trimerization and substrate transport domains.

    PubMed

    Mortensen, Ole V; Liberato, José L; Coutinho-Netto, Joaquim; Dos Santos, Wagner F; Fontana, Andréia C K

    2015-04-01

    Excitatory amino acid transporters (EAATs) regulate glutamatergic signal transmission by clearing extracellular glutamate. Dysfunction of these transporters has been implicated in the pathogenesis of various neurological disorders. Previous studies have shown that venom from the spider Parawixia bistriata and a purified compound (Parawixin1) stimulate EAAT2 activity and protect retinal tissue from ischemic damage. In the present study, the EAAT2 subtype specificity of this compound was explored, employing chimeric proteins between EAAT2 and EAAT3 transporter subtypes and mutants to characterize the structural region targeted by the compound. This identified a critical residue (Histidine-71 in EAAT2 and Serine-45 in EAAT3) in transmembrane domain 2 (TM2) to be important for the selectivity between EAAT2 and EAAT3 and for the activity of the venom. Using the identified residue in TM2 as a structural anchor, several neighboring amino acids within TM5 and TM8 were identified to also be important for the activity of the venom. This structural domain of the transporter lies at the interface of the rigid trimerization domain and the central substrate-binding transport domain. Our studies suggest that the mechanism of glutamate transport enhancement involves an interaction with the transporter that facilitates the movement of the transport domain. We identified a domain (purple star) in the glutamate transporter EAAT2 that is important for transport stimulation through a spider venom, and suggest a mechanism for enhanced transporter function through facilitated substrate translocation (arrow). Because the dysfunction of glutamate transporters is implicated in the pathogenesis of neurological disorders, understanding the mechanisms of enhanced transport could have therapeutic implications.

  13. Disease Modifying Effects of the Spider Toxin Parawixin2 in the Experimental Epilepsy Model

    PubMed Central

    Godoy, Lívea Dornela; Gobbo-Neto, Leonardo; dos Santos, Wagner Ferreira

    2017-01-01

    (1) Background: Temporal lobe epilepsy (TLE) is the most common type of epilepsy in adults. It is also the one with the highest percentage of drug-resistance to the current available anti-epileptic drugs (AED). Additionaly, most antiepileptic drugs are only able to control seizures in epileptogenesis, but do not decrease the hippocampal neurodegenerative process. TLE patients have a reduced population of interneuronal cells, which express Parvalbumin (PV) proteins. This reduction is directly linked to seizure frequency and severity in the chronic period of epilepsy. There is therefore a need to seek new therapies with a disease-modifying profile, and with efficient antiepileptic and neuroprotective properties. Parawixin2, a compound isolated from the venom of the spider Parawixia bistriata, has been shown to inhibit GABA transporters (GAT) and to have acute anticonvulsant effects in rats. (2) Methods: In this work, we studied the effects of Parawixin2 and Tiagabine (an FDA- approved GAT inhibitor), and compared these effects in a TLE model. Rats were subjected to lithium-pilocarpine TLE model and the main features were evaluated over a chronic period including: (a) spontaneous recurrent seizures (SRS), (b) neuronal loss, and (c) PV cell density in different regions of the hippocampus (CA1, CA3, DG and Hilus). (3) Results: Parawixin2 treatment reduced SRS frequency whereas Tiagabine did not. We also found a significant reduction in neuronal loss in CA3 and in the hilus regions of the hippocampus, in animals treated with Parawixin2. Noteworthy, Parawixin2 significantly reversed PV cell loss observed particularly in DG layers. (4) Conclusions: Parawixin2 exerts a promising neuroprotective and anti-epileptic effect and has potential as a novel agent in drug design. PMID:28841161

  14. Molecular evidence for a spotted fever group Rickettsia species in the tick Amblyomma longirostre in Brazil.

    PubMed

    Labruna, Marcelo B; McBride, Jere W; Bouyer, Donal H; Camargo, Luis Marcelo A; Camargo, Erney P; Walker, David H

    2004-05-01

    Two Amblyomma longirostre adult male ticks were collected from a Brazilian porcupine Coendou prehensilis L. in the state of Rondonia, Western Amazon, Brazil. The two ticks were pooled for DNA extraction and tested for the presence of rickettsial DNA by amplifying portions of the gltA, 17-kDa, ompA, and ompB rickettsial genes by polymerase chain reaction (PCR). Portions of the four genes were amplified from the sample and subsequently sequenced. These results indicated the presence of a Rickettsia strain infecting A. longirostre, which was designated as strain Aranha. Compared with homologous ompA rickettsial sequences, "Rickettsia amblyommii" ompA seemed to be the closest relative to Aranha (similarity values: 99.0-99.3%). Phylogenetic analyses of more conserved genes including 17-kDa and gtlA partial sequences indicated that this Rickettsia sp. is a spotted fever group rickettsia. The partial ompB sequence of strain Aranha was distinct from all homologous sequences available in GenBank. Although our ompA analysis suggested a very close molecular phylogenetic relationship of Aranha with "R. amblyommii," we cannot at this time determine if Aranha is a new strain of "R. amblyommii" or a new Rickettsia species in South America.

  15. Four new species of the genus Mongoliana Distant (Hemiptera: Fulgoromorpha: Issidae) from southern China.

    PubMed

    Meng, Rui; Wang, Yinglun; Qin, Daozheng

    2016-01-05

    Four new species in the planthopper genus Mongoliana Distant from southern China (Hemiptera: Fulgoromorpha: Issidae) are reported. Three of them, M. bistriata sp. nov., M. latistriata sp. nov. and M. albimaculata sp. nov., are described and illustrated; the fourth new one, M. arcuata sp. nov., is briefly described for M. triangularis Chen, Zhang & Chang which was a misidentification of M. triangularis Che, Wang & Chou. M. recurrens (Butler, 1875) is re-described and remarks for its current status is given. A key to all known species of Mongoliana is provided. The distribution and morphological peculiarities of the genus are briefly discussed.

  16. Nest relocation and high mortality rate in a Neotropical social wasp: Impact of an exceptionally rainy La Niña year.

    PubMed

    Dejean, Alain; Carpenter, James M; Gibernau, Marc; Leponce, Maurice; Corbara, Bruno

    2010-01-01

    After noting the forecast of a La Niña episode, associated with heavy rainfall in French Guiana, we monitored the fate of wasp nests before and during the 2006 short rainy season. The population of the most abundant epiponine wasp species, Polybia bistriata, decreased dramatically during the short rainy season (60.6% of the nests disappeared) then remained low for at least 18 months. Colonies that survived moved from the shelter of large, low leaves (a situation well adapted to the previous dry season) of the most frequent substrate tree, Clusia grandiflora (Clusiaceae), to upper leaves, better ventilated and whose orientation provides good protection from the rain. Therefore, the possibility of moving the nest higher during the first rains following the dry season seems very adaptive as colonies that do not do so are eliminated during the La Niña years, whose frequency will increase with global climate change.

  17. Nanostructural and mechanical property changes to spider silk as a consequence of insecticide exposure.

    PubMed

    Benamú, Marco; Lacava, Mariángeles; García, Luis F; Santana, Martín; Fang, Jian; Wang, Xungai; Blamires, Sean J

    2017-08-01

    Neonicotinoids are one of the world's most extensively used insecticides, but their sub-lethal influences on non-target and beneficial organisms are not well known. Here we exposed the orb web spider Parawixia audax, which is found on arable lands in Uruguay, to a sub-lethal concentration of the broad spectrum insecticide Geonex (thiamethoxam + lambda-cyhalothrin) and monitored their web building. We collected their major ampullate silk and subjected it to tensile tests, wide-angle X-ray diffraction (WAXS) analysis, and amino acid composition analysis. Around half of the exposed spiders failed to build webs. Those that built webs produced irregular webs lacking spiral threads. The mechanical properties, nanostructures, and amino acid compositions of the silk were all significantly affected when the spiders were exposed to insecticides. We found that silk proline, glutamine, alanine and glycine compositions differed between treatments, indicating that insecticide exposure induced downregulation of the silk protein MaSp2. The spiders in the control group had stronger, tougher and more extensible silks than those in the insecticide exposed group. Our WAXS analyses showed the amorphous region nanostructures became misaligned in insecticide exposed silks, explaining their greater stiffness. While the insecticide dose we subjected P. audax to was evidently sub-lethal, the changes in silk physicochemical properties and the impairment to web building will indelibly affect their ability to catch prey. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Detection of Rickettsia bellii and Rickettsia amblyommii in Amblyomma longirostre (Acari: Ixodidae) from Bahia state, Northeast Brazil

    PubMed Central

    McIntosh, Douglas; Bezerra, Rodrigo Alves; Luz, Hermes Ribeiro; Faccini, João Luiz Horacio; Gaiotto, Fernanda Amato; Giné, Gastón Andrés Fernandez; Albuquerque, George Rego

    2015-01-01

    Studies investigating rickettsial infections in ticks parasitizing wild animals in the Northeast region of Brazil have been confined to the detection of Rickettsia amblyommii in immature stages of Amblyomma longirostre collected from birds in the state of Bahia, and in immatures and females of Amblyomma auriculariumcollected from the striped hog-nosed skunk (Conepatus semistriatus) and armadillos (Euphractus sexcinctus) in the state of Pernambuco. The current study extends the distribution of R. amblyommii (strain Aranha), which was detected in A. longirostre collected from the thin-spined porcupine Chaetomys subspinosus and the hairy dwarf porcupine Coendou insidiosus. In addition, we report the first detection of Rickettsia bellii in adults of A. longirostre collected from C. insidiosus in the state of Bahia. PMID:26413074

  19. Detection of Rickettsia bellii and Rickettsia amblyommii in Amblyomma longirostre (Acari: Ixodidae) from Bahia state, Northeast Brazil.

    PubMed

    McIntosh, Douglas; Bezerra, Rodrigo Alves; Luz, Hermes Ribeiro; Faccini, João Luiz Horacio; Gaiotto, Fernanda Amato; Giné, Gastón Andrés Fernandez; Albuquerque, George Rego

    2015-01-01

    Studies investigating rickettsial infections in ticks parasitizing wild animals in the Northeast region of Brazil have been confined to the detection of Rickettsia amblyommii in immature stages of Amblyomma longirostre collected from birds in the state of Bahia, and in immatures and females of Amblyomma auricularium collected from the striped hog-nosed skunk (Conepatus semistriatus) and armadillos (Euphractus sexcinctus) in the state of Pernambuco. The current study extends the distribution of R. amblyommii (strain Aranha), which was detected in A. longirostre collected from the thin-spined porcupine Chaetomys subspinosus and the hairy dwarf porcupine Coendou insidiosus. In addition, we report the first detection of Rickettsia bellii in adults of A. longirostre collected from C. insidiosus in the state of Bahia.

  20. Review of the Southeast Asian millipede genus Antheromorpha Jeekel, 1968 (Diplopoda, Polydesmida, Paradoxosomatidae)

    PubMed Central

    Likhitrakarn, Natdanai; Golovatch, Sergei I.; Panha, Somsak

    2016-01-01

    Abstract The genus Antheromorpha is redefined and shown to comprise 11 valid species: Antheromorpha miranda (Pocock, 1895), Antheromorpha bistriata (Pocock, 1895), Antheromorpha comotti (Pocock, 1895), Antheromorpha festiva (Brölemann, 1896), Antheromorpha harpaga (Attems, 1937), Antheromorpha mediovirgata (Carl, 1941), Antheromorpha minlana (Pocock, 1895), Antheromorpha pardalis (Pocock, 1895), Antheromorpha paviei (Brölemann, 1896), comb. n., Antheromorpha rosea Golovatch, 2013 and Antheromorpha uncinata (Attems, 1931). Three new synonymies are proposed: Antheromorpha bivittata (Pocock, 1895) and Antheromorpha melanopleuris (Pocock, 1895) are synonymized under Antheromorpha miranda (Pocock, 1895), and Antheromorpha orophila (Carl, 1941) under Antheromorpha comotti (Pocock, 1895). Detailed descriptions and illustrations of fresh material from Thailand and Malaysia are given, especially regarding colour patterns which appear to be crucial for accurate species identifications. Two Antheromorpha species proposed by Attems are redescribed, based on type material. The genus is rediagnosed and a key and a distribution map are also provided. At least in Thailand, adult Antheromorpha rosea have been found to occur every year only for one or two weeks in September or October, disappearing thereafter. PMID:27110157

  1. Review of the Southeast Asian millipede genus Antheromorpha Jeekel, 1968 (Diplopoda, Polydesmida, Paradoxosomatidae).

    PubMed

    Likhitrakarn, Natdanai; Golovatch, Sergei I; Panha, Somsak

    2016-01-01

    The genus Antheromorpha is redefined and shown to comprise 11 valid species: Antheromorpha miranda (Pocock, 1895), Antheromorpha bistriata (Pocock, 1895), Antheromorpha comotti (Pocock, 1895), Antheromorpha festiva (Brölemann, 1896), Antheromorpha harpaga (Attems, 1937), Antheromorpha mediovirgata (Carl, 1941), Antheromorpha minlana (Pocock, 1895), Antheromorpha pardalis (Pocock, 1895), Antheromorpha paviei (Brölemann, 1896), comb. n., Antheromorpha rosea Golovatch, 2013 and Antheromorpha uncinata (Attems, 1931). Three new synonymies are proposed: Antheromorpha bivittata (Pocock, 1895) and Antheromorpha melanopleuris (Pocock, 1895) are synonymized under Antheromorpha miranda (Pocock, 1895), and Antheromorpha orophila (Carl, 1941) under Antheromorpha comotti (Pocock, 1895). Detailed descriptions and illustrations of fresh material from Thailand and Malaysia are given, especially regarding colour patterns which appear to be crucial for accurate species identifications. Two Antheromorpha species proposed by Attems are redescribed, based on type material. The genus is rediagnosed and a key and a distribution map are also provided. At least in Thailand, adult Antheromorpha rosea have been found to occur every year only for one or two weeks in September or October, disappearing thereafter.

  2. Comparing alignment methods for inferring the history of the new world lizard genus Mabuya (Squamata: Scincidae).

    PubMed

    Whiting, Alison S; Sites, Jack W; Pellegrino, Katia C M; Rodrigues, Miguel T

    2006-03-01

    The rapid increase in the ability to generate molecular data, and the focus on model-based methods for tree reconstruction have greatly advanced the use of phylogenetics in many fields. The recent flurry of new analytical techniques has focused almost solely on tree reconstruction, whereas alignment issues have received far less attention. In this paper, we use a diverse sampling of gene regions from lizards of the genus Mabuya to compare the impact, on phylogeny estimation, of new maximum likelihood alignment algorithms with more widely used methods. Sequences aligned under different optimality criteria are analyzed using partitioned Bayesian analysis with independent models and parameter settings for each gene region, and the most strongly supported phylogenetic hypothesis is then used to test the hypothesis of two colonizations of the New World by African scincid lizards. Our results show that the consistent use of model-based methods in both alignment and tree reconstruction leads to trees with more optimal likelihood scores than the use of independent criteria in alignment and tree reconstruction. We corroborate and extend earlier evidence for two independent colonizations of South America by scincid lizards. Relationships within South American Mabuya are found to be in need of taxonomic revision, specifically complexes under the names M. heathi, M. agilis, and M. bistriata (sensu, M.T. Rodrigues, Papeis Avulsos de Zoologia 41 (2000) 313).

  3. When and Why Parents Seek Dental Care for Children under 36 Months.

    PubMed

    Volpato, Luiz Evaristo Ricci; Palti, Dafna Geller; Lima, Jose Eduardo de Oliveira; Machado, Maria Aparecida de Andrade Moreira; Aranha, Andreza Maria Fabio; Bandeca, Matheus Coelho; Pedro, Fabio Luis Miranda; Borges, Alvaro Henrique

    2013-08-01

    The aim was to analyze an infant preventive program determining at what age parents take their children for their first dental visit and the reasons why they do it. A total of 844 children aged from 0 to 36 months, enrolled in the program of oral health maintenance of the Baby Clinic, participated in this study. During the first dental visit, the parents were inquired about the reasons that led them to enroll their children in the program. One trained investigator identified this reasons on the records and classified them according to the following scores: orientation/prevention, caries treatment, malpositioned teeth, dental trauma, tooth color alterations and others. Orientation/prevention was the most prevalent reason from 0-6 months to 25-30 months of age, and at the age 30-36 months, the reason caries/treatment overcame orientation/prevention, becoming the most prevalent reason in that age group. The third place was occupied by dental trauma. The mean age parents seek for dental care to their children was 14, 92 months. This study showed a preferentially preventive/educational profile for the children. However, lots of parents still take children to the dentist preferentially for curative instead of preventive treatment. How to cite this article: Volpato LE, Palti DG, Lima JE, Machado MA, Aranha AM, Bandeca MC, Pedro FL, Borges AH. When and Why Parents Seek Dental Care for Children under 36 Months. J Int Oral Health 2013; 5(4):21-25.

  4. Systematics and biogeography of the Neotropical genus Mabuya, with special emphasis on the Amazonian skink Mabuya nigropunctata (Reptilia, Scincidae).

    PubMed

    Miralles, A; Carranza, S

    2010-03-01

    dispersal between these two species. The split between M. bistriata and M. altamazonica and between the occidental and (meridional+oriental) clades of M. nigropunctata fits very well with the biogeographic split between the eastern and western Amazon basins reported for several other taxa. Copyright 2009 Elsevier Inc. All rights reserved.

  5. Use Of The Gpr To Characterize Sedimentary Structures Of Lakes In Sub-Humid Drainage System, Southeast Brazil

    NASA Astrophysics Data System (ADS)

    Aranha, P. A.; Augustin, C. H.

    2012-12-01

    PAULO ROBERTO ANTUNES ARANHA IGC - UNIVERSIDADE FEDERAL DE MINAS GERAIS - AV ANTONIO CARLOS 6.627 - CEP: 31270901-BELO HORIZONTE- MG - BRAZIL CRISTINA ROCHA AUGUSTIN - IGC - UNIVERSIDADE FEDERAL DE MINAS GERAIS - AV ANTONIO CARLOS 6.627 - CEP: 31270901-BELO HORIZONTE- MG - BRAZIL System of lakes located in the sandstones domains of Supergrupo Urucuia, in the State Park Veredas do Peruaçu, north of the State of Minas Gerais, Brazil, are common features in ecosystems of the Veredas, a biome of the Cerrado (Savanna-Open pasture). The linearity of these lakes suggests that they could have, in the past, belonged to the same drainage system, that would have been disconnected throughout the evolution of the Vereda system. The objective of this research is with the help of the GPR and using 100 MHz antennaes to obtain radargram images that could assist in the interpretation of the structures occurring at the bottom of these lakes. It is possible do identify on the radargrams reflectors that can be correlated with depositional system. These reflectore have the concave form. The results of these radargrames indicate great conformity between the concave form of the sediments and that of the bottom of the lake, allowing to assume that this deposition has been occurring since a long time ago. Therefore, if there was a connection between the study lake and those located in its proximity it has occurred a long time, before the deposition of the sedimentary sequences had been deposited. The thickness of the sediments, that varies since 2m until 5m, indicates that or either this deposition was either a very rapid one so that could generate a fast deposition, or it has been taking place during a considerable geologic long time.; Data acquisitiont;