Search results for "Spider"
showing 10 items of 97 documents
Toward oxygen binding curves of single respiratory proteins
2004
Oxygen binding curves of single molecules promise to discriminate between different models describing cooperativity because load distributions are accessible. Individual tarantula hemocyanins could be detected by fluorescence correlation spectroscopy using intrinsic tryptophan fluorescence as sensor of bound oxygen. However, imaging of immobilized proteins was not possible due to fast photo-bleaching. It is shown that tetra-methyl-carboxy-rhodamine (TAMRA), commonly used as a fluorescence label in single-molecule spectroscopy, can also be applied to monitor bound oxygen. The dye's fluorescence is quenched due to Förster energy transfer to the oxygenated active sites of hemocyanin.
Il tarantismo in Sicilia
2017
Il testo prende in esame il complesso di materiali editi e inediti (fonti storiche e archivistiche, documenti musicali, testimonianze etnografiche) che attestano la presenza del tarantismo in Sicilia dalla metà del Seicento alla fine dell’Ottocento. Il caso siciliano viene quindi inquadrato nell’ambito dell’ampia letteratura che ruota intorno al fenomeno, a partire dal classico studio di Ernesto De Martino fino al dibattito sull’interpretazione del fenomeno fra i poli dell’esorcismo e della possessione, dovuto soprattutto all’etnomusicologo francese Gilber Rouget. L’analisi viene quindi estesa alla tradizione dei guaritori dei morsi di serpenti (i ciaràuli), che con il tarantismo condividon…
Spider bite mimicking pyoderma gangrenosum in sJIA: a case report
2020
Introduction: Several paediatric patients manifest conditions commonly misdiagnosed as spider bites, which however, can include other arthropods bites; bacterial, viral, and mycotic infections; vasculitis; dermatological diseases; miscellaneous conditions as drug reactions, chemical injuries. Objectives: In Italy, spiders which are likely to be associated with severe toxin mediated tissue damage are uncommon, especially in urban zones. However, a minor trauma may be a precipitating factor for pyoderma gangrenosum particularly over the legs, in association with inflammatory bowel disease, haematologic diseases and Juvenile Idiopathic Arthritis (JIA).
Honesty of agonistic signalling and effects of size and motivation asymmetry in contests
1999
Game theoretical models predict that the main function of fighting behaviour is to assess the relative fighting ability of opponents. The sequential assessment game has often been used to investigate contests, while honest signalling theory has received much less attention. With the wolf spider Hygrolycosa rubrofasciata we investigated whether male agonistic signalling can reveal honest information about fighting ability, and how size and motivation asymmetries affect male fighting behaviour. We also determined whether male–male competition affects the courtship behaviour of the males. We found that agonistic drumming activity is an honest indicator of male fighting ability, and that relati…
The age and evolution of sociality in Stegodyphus spiders: a molecular phylogenetic perspective
2006
Social, cooperative breeding behaviour is rare in spiders and generally characterized by inbreeding, skewed sex ratios and high rates of colony turnover, processes that when combined may reduce genetic variation and lower individual fitness quickly. On these grounds, social spider species have been suggested to be unstable in evolutionary time, and hence sociality a rare phenomenon in spiders. Based on a partial molecular phylogeny of the genus Stegodyphus , we address the hypothesis that social spiders in this genus are evolutionary transient. We estimate the age of the three social species, test whether they represent an ancestral or derived state and assess diversification relative to s…
Group founding and breeding structure in the subsocial spider stegodyphus lineatus (Eresidae)
1999
Co-operative behaviour may evolve by enhancing the genetic similarity of group members. Increased group similarity is thought to be the basis for the 'subsocial route' of social evolution in the spider family Eresidae. Two processes may promote the similarity of individuals within populations or breeding groups, namely philopatry in stable environments and founder events in a stochastic environment. We show that both processes led to genetic differentiation within and among populations of the subsocial spider Stegodyphus lineatus. Within populations we distinguished between the genetic structure caused by random mating and philopatry in old breeding groups and that caused by newly founded g…
EINE NEUE JAPANISCHE SYNAEMA-ART (ARANEAE: THOMISIDAE)
1983
A new species of the spider genus Synaema SIMON, 1864, from Japan is described under the name of Synaema chikunii. This spider was found in the mountainous regions of Honshu and Hokkaido.
Spider cues stimulate feeding, weight gain and survival of crickets
2014
1. To avoid predation, prey often change their behaviour upon encountering cues of predator presence. Such behavioural changes should enhance individual survival, but are likely to be energy-demanding. This should deplete energy reserves of the prey, unless it increases food intake. 2. These hypotheses were studied by conducting two microcosm experiments. In the first, crickets were kept on plants previously occupied by a spider or on control plants. After 3 days leaf consumption and weight gain of the crickets were quantified. In the second experiment, crickets were kept in the presence or absence of spider cues for 3 days. Spiders were then added and predation of the crickets was recorded…
On Adcatomus ciudadus Karsch 1880, a remarkable spider species from Lima, with comments on South American Sparassidae (Arachnida, Araneae)
2008
The ♂-holotype of Adcatomus ciudadus Karsch 1880 was located in the Zoologisches Museum der Humboldt-Universitat Berlin and recognized as a representative of the spider family Sparassidae. A redescription of the holotype is given and the systematic position of the species is discussed. A review on taxonomic work on South American Sparassidae is also given. Der ♂-Holotyp von Adcatomus ciudadus Karsch 1880 wurde im Zoologischen Museum der Humboldt-Universitat Berlin ausfindig gemacht und als Vertreter der Spinnenfamilie Sparassidae identifiziert. Der Holotyp wird beschrieben und seine systematische Stellung diskutiert. Es wird ein zusammenfassender Ruckblick auf taxonomische Arbeiten uber sud…
Subunit sequences of the 4 x 6-mer hemocyanin from the golden orb-web spider, Nephila inaurata. Intramolecular evolution of the chelicerate hemocyani…
2003
The transport of oxygen in the hemolymph of many arthropod and mollusc species is mediated by large copper-proteins that are referred to as hemocyanins. Arthropod hemocyanins are composed of hexamers and oligomers of hexamers. Arachnid hemocyanins usually form 4 x 6-mers consisting of seven distinct subunit types (termed a-g), although in some spider taxa deviations from this standard scheme have been observed. Applying immunological and electrophoretic methods, six distinct hemocyanin subunits were identified in the red-legged golden orb-web spider Nephila inaurata madagascariensis (Araneae: Tetragnathidae). The complete cDNA sequences of six subunits were obtained that corresponded to a-,…