13,091 results
Search Results
102. Free myo-inositol as major component of Paeonia lactiflora syrup.
- Author
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Springer GF and Desai PR
- Subjects
- Chromatography, Paper, Indicators and Reagents, Silver Nitrate, Solvents, Spectrum Analysis, Inositol analysis, Plants
- Published
- 1966
- Full Text
- View/download PDF
103. [First discovery of a wild form of Claviceps purpurea on Paspalum].
- Author
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Kobel H and Stopp K
- Subjects
- Chromatography, Paper, Ergot Alkaloids analysis, Ascomycota classification, Plants
- Published
- 1967
- Full Text
- View/download PDF
104. [Pigment formation in callus cultures of Beta beets].
- Author
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Constabel F
- Subjects
- Chromatography, Paper, Culture Techniques, Pigments, Biological analysis, Pigments, Biological biosynthesis, Plants, Edible metabolism, Vegetables
- Published
- 1967
- Full Text
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105. [On the occurrence of delta4-androstene-3,17-dione in the sulfate fraction of urinary 17-ketosteroids].
- Author
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Schubert K, Hobe G, and Wehrberger K
- Subjects
- Androgens metabolism, Chromatography, Chromatography, Paper, Glucuronates, Sulfates, Testosterone urine, 17-Ketosteroids urine, Androgens urine
- Published
- 1967
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106. 3,4-Dihydroxy-mandelic acid in the mushroom gland of cockroaches.
- Author
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Adiyoda KG
- Subjects
- Animals, Chromatography, Paper, Exocrine Glands metabolism, Exocrine Glands analysis, Insecta, Mandelic Acids, Phenols analysis
- Published
- 1969
- Full Text
- View/download PDF
107. [On the variability of substances contained in the goat's rue (Galega officinalis L.)].
- Author
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Schäfer J and Stein M
- Subjects
- Chromatography, Paper, Plants, Medicinal analysis, Pyrroles analysis, Guanidines analysis, Quinazolines analysis
- Published
- 1967
- Full Text
- View/download PDF
108. Paper chromatographic detection and separation of 2-ketogluconate-phosphoric esters.
- Author
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Ley, J.
- Published
- 1955
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109. Improved Zaffaroni-systems for the paper chromatography of C-steroids.
- Author
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Fehér, T.
- Published
- 1965
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110. Mechanistic modelling of cancer: some reflections from software engineering and philosophy of science.
- Author
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Cañete-Valdeón, José, Wieringa, Roel, and Smallbone, Kieran
- Abstract
There is a growing interest in mathematical mechanistic modelling as a promising strategy for understanding tumour progression. This approach is accompanied by a methodological change of making research, in which models help to actively generate hypotheses instead of waiting for general principles to become apparent once sufficient data are accumulated. This paper applies recent research from philosophy of science to uncover three important problems of mechanistic modelling which may compromise its mainstream application, namely: the dilemma of formal and informal descriptions, the need to express degrees of confidence and the need of an argumentation framework. We report experience and research on similar problems from software engineering and provide evidence that the solutions adopted there can be transferred to the biological domain. We hope this paper can provoke new opportunities for further and profitable interdisciplinary research in the field. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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111. How is a giant sperm ejaculated? Anatomy and function of the sperm pump, or 'Zenker organ,' in Pseudocandona marchica (Crustacea, Ostracoda, Candonidae).
- Author
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Yamada, Shinnosuke and Matzke-Karasz, Renate
- Abstract
'Giant sperm', in terms of exceptionally long spermatozoa, occur in a variety of taxa in the animal kingdom, predominantly in arthropod groups, but also in flatworms, mollusks, and others. In some freshwater ostracods (Cypridoidea), filamentous sperm cells reach up to ten times the animal's body length; nonetheless, during a single copulation several dozen sperm cells can be transferred to the female's seminal receptacle. This highly effective ejaculation has traditionally been credited to a chitinous-muscular structure within the seminal duct, which has been interpreted as a sperm pump. We investigated this organ, also known as the Zenker organ, of a cypridoid ostracod, Pseudocandona marchica, utilizing light and electron microscope techniques and produced a three-dimensional reconstruction based on serial semi-thin histological sections. This paper shows that numerous muscle fibers surround the central tube of the Zenker organ, running in parallel with the central tube and that a thin cellular layer underlies the muscular layer. A cellular inner tube exists inside the central tube. A chitinous-cellular structure at the entrance of the organ has been recognized as an ejaculatory valve. In male specimens during copulation, we confirmed a small hole derived from the passage of a single spermatozoon through the valve. The new data allowed for proposing a detailed course of operation of the Zenker organ during giant sperm ejaculation. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
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112. Relationship between CO at a rural site and integral measures of atmospheric stagnation, recirculation, and ventilation.
- Author
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Pérez, Isidro A., Sánchez, M. Luisa, García, M. Ángeles, and Paredes, Vanessa
- Abstract
Integral quantities, wind run, S, and recirculation factor, R, useful for describing air flow, are calculated and combined with CO mixing ratios. Meteorological observations were obtained from a RASS sodar and CO mixing ratios from a continuous analyzer installed at a rural site in the upper Spanish plateau. The measuring campaign spread over 3 years and two approaches were followed. The first approach considered integral quantities on a daily basis and two classifications of air flow, to date scarcely used. The first classification distinguished among stagnation, recirculation, and ventilation, the second considering synoptic, meso-, and local scales. Moreover, 52.94% of daily values handled in this paper corresponded to ventilation and 49.70% to synoptic scale. The main goal of this approach is the subsequent link between the two classifications: the synoptic scale was associated with ventilation, mesoscale with recirculation and local scale partially with recirculation. CO observations were distributed in air flow groups following these classifications and mesoscale processes were satisfactorily described since noticeable evidence of transport from nearby cities was observed. In the second approach, S and R pairs were used and CO mixing ratios were distributed following percent intervals of ventilation, calculated by binning these pairs. The main goal of the second approach is to consider only three groups of mixing ratios. In the first group, with high ventilation, mixing ratios were low. With intermediate ventilation, mixing ratios were medium, and with low ventilation mixing ratios were high. A contrast of 21 ppm between the third and first groups was obtained at the 95th percentile. Finally, the second group provided a contrast of 3 ppm between north and south directions and also between east and west attributed to transport from nearby cities. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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113. Chemically mediated burrow recognition in the Mexican tarantula Brachypelma vagans female.
- Author
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Ariane Dor, Salima Machkour-M’Rabet, Luc Legal, Trevor Williams, and Yann Hénaut
- Abstract
Abstract Chemically mediated communication is common in spiders but has been poorly studied in burrowing tarantulas. This study aimed to determine whether chemical cues influence the behaviour of females of Brachypelma vagans, a Mexican species of tarantula, during encounters with previously inhabited burrows or with extracts from the silk of conspecific females. In laboratory choice tests, female tarantulas entered a burrow that had previously been inhabited by a conspecific female significantly more frequently than a burrow that had never been inhabited. The identity of the previous inhabitant also affected the number of spiders that chose to enter a burrow. Spiders were quicker to choose and enter a burrow previously inhabited by themselves than a burrow previously inhabited by a conspecific or a burrow that had not been previously inhabited. Hexane, methanol and dichloromethane extracts of conspecific silk elicited different responses from female tarantulas when extracts were placed on filter paper disks at one end of an experimental arena with a control filter paper disk, on to which the corresponding solvent alone had been pipetted, placed on the other end of the arena. Spiders showed the strongest responses to hexane extracts of silk, with a significant preference to move towards the hexane extract and a significantly greater period of time spent in proximity to the hexane extract compared to the control disk. Overall and in contrast to expectations, tarantulas were most strongly attracted to the cues left by other conspecific females. As encounters between B. vagans females usually lead to aggression and mortality of one of the participants, we conclude that chemical cues are not signals that are deliberately released by burrow-inhabiting females but may inadvertently escape and cannot be easily suppressed. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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114. Two experimental tests of the relationship between group stability and aggressive conflict in Polistes wasps.
- Author
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Elizabeth Tibbetts and Hudson Reeve
- Abstract
Abstract Two field experiments were used to examine how the relative benefits of cooperation influence within-group conflict in foundress associations of the paper wasp Polistes dominulus. P. dominulus foundresses can either nest alone or cooperate with other foundresses. We experimentally manipulated the relative benefits of co-foundress associations vs independent reproduction and tested the effect on aggressive within-group conflict. First, we examined aggression between alpha and beta co-foundresses before and after lower-ranking foundresses were removed. Removal of subordinates increases the relative contributions of the remaining subordinates to group reproductive output as there are fewer adults to care for the brood. Transactional models predict that group conflict over reproductive shares will increase as the relative benefits of grouping increase. As predicted, aggression between the co-foundresses significantly increased following subordinate removal. Second, we experimentally reduced ecological constraints on independent nesting by placing a previously orphaned, adoptable nest comb near the occupied nests. Providing an independent breeding opportunity is predicted to increase the benefits of independent reproduction relative to those of cooperating, thereby reducing group stability and aggression. As predicted, aggression between dominant and subordinate foundresses significantly decreased after the orphaned comb was presented. Therefore, group members sense variation in ecological constraints and relative productivity contributions and quickly modulate their behavior in response. Overall, these two experiments suggest that paper wasps behave as if within-group competition is limited by the threat of group dissolution such that stable groups where cooperation is strongly favored can withstand higher levels of conflict than unstable groups. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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115. The effect of a green leaf volatile on host plant finding by larvae of a herbivorous insect.
- Author
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Müller, Caroline and Hilker, M.
- Abstract
The role of a general green leaf volatile (glv) in host finding by larvae of the oligophagous chrysomelid Cassida denticollis was investigated using a new bioassay which takes into account the need for neonate larvae of this species to climb fresh host plants from the ground. A "stem arena" was designed in which plant stems of the host, tansy ( Tanacetum vulgare), and stem dummies (tooth picks), both wrapped in perforated filter paper, were offered to neonate larvae. The wrapping allowed olfactory responses to be tested by preventing access to contact stimuli of stems and dummies. Larvae significantly preferred to climb the wrapped tansy stems over dummies after a period of 15 min. The test glv, ( Z)-3-hexen-1-ol, was not attractive when applied to dummies. However, when the glv was applied to the bottom of the arena, the ability of larvae to discriminate between host stems and untreated dummies was significantly enhanced. More larvae climbed wrapped host stems than dummies even within 5 min. While numerous other herbivorous insects are known to be directly attracted by glv, this study shows that a singly offered glv on its own is unattractive to an herbivore but enhances the herbivore's ability to differentiate between host and nonhost plants. [ABSTRACT FROM AUTHOR]
- Published
- 2000
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116. Biomimetics and the case of the remarkable ragworms
- Author
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Hesselberg, Thomas
- Published
- 2007
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117. Analysis of Inorganic Compounds by Paper Chromatography: Part III. Study of various factors effecting the R values of cations in the separation of a mixture of copper, lead, bismuth, cadmium and mercury.
- Author
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Tewari, Swarup
- Published
- 1954
- Full Text
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118. Close-range cues used by males of Polistes dominula in sex discrimination.
- Author
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da Silva RC, Van Meerbeeck L, do Nascimento FS, Wenseleers T, and Oi CA
- Subjects
- Animals, Female, Hydrocarbons pharmacology, Male, Sexual Behavior, Animal drug effects, Videotape Recording, Cues, Hydrocarbons metabolism, Sex Attractants chemistry, Wasps physiology
- Abstract
Sexual pheromones are chemical molecules responsible for mediating sex recognition and mating events. Long- and close-range sexual pheromones act differently. The first type is released to attract potential partners, whereas the second coordinates the interactions after potential mating partners encounter each other. Cuticular hydrocarbons (CHCs) have been suggested to be important cues in the mating systems of several Hymenoptera species, although empirical data are still lacking for many species. Here, we evaluated whether males of the model species Polistes dominula can differentiate the sex of individuals based on their CHC composition. In August 2019, several post-worker emergent nests (n = 19) were collected in the vicinity of Leuven (Belgium) and taken to the lab (KU Leuven), where newly emerged females and males were sampled, marked individually, and kept in plastic boxes for at least a week before being used in the mating trials. Focal males were paired with females and males from different nests and subjected to five different conditions: (I) alive, (II) dead, (III) CHCs washed, (IV) CHCs partially returned, and (V) CHCs from the opposite sex. We videotaped the interactions for 10 min and analysed the duration and different behavioural interactions of the focal male. Our results indicate that CHCs may be used by males as cues to recognise a potential mating partner in P. dominula, since the focal males displayed specific courtship behaviours exclusively toward females. Although we cannot exclude that visual cues could also be used in combination with the chemical ones, we empirically demonstrate that CHCs may be important to convey sexual information at close range in mating systems, allowing fast decisions toward potential sexual partners or rivals.
- Published
- 2021
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119. Giant honeybees ( Apis dorsata) mob wasps away from the nest by directed visual patterns.
- Author
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Kastberger, Gerald, Weihmann, Frank, Zierler, Martina, and Hötzl, Thomas
- Abstract
The open nesting behaviour of giant honeybees ( Apis dorsata) accounts for the evolution of a series of defence strategies to protect the colonies from predation. In particular, the concerted action of shimmering behaviour is known to effectively confuse and repel predators. In shimmering, bees on the nest surface flip their abdomens in a highly coordinated manner to generate Mexican wave-like patterns. The paper documents a further-going capacity of this kind of collective defence: the visual patterns of shimmering waves align regarding their directional characteristics with the projected flight manoeuvres of the wasps when preying in front of the bees' nest. The honeybees take here advantage of a threefold asymmetry intrinsic to the prey-predator interaction: (a) the visual patterns of shimmering turn faster than the wasps on their flight path, (b) they 'follow' the wasps more persistently (up to 100 ms) than the wasps 'follow' the shimmering patterns (up to 40 ms) and (c) the shimmering patterns align with the wasps' flight in all directions at the same strength, whereas the wasps have some preference for horizontal correspondence. The findings give evidence that shimmering honeybees utilize directional alignment to enforce their repelling power against preying wasps. This phenomenon can be identified as predator driving which is generally associated with mobbing behaviour (particularly known in selfish herds of vertebrate species), which is, until now, not reported in insects. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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120. Can the envisaged reductions of fossil fuel CO2 emissions be detected by atmospheric observations?
- Author
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Christian Rödenbeck and Ingeborg Levin
- Subjects
Greenhouse Effect ,Fossil Fuels ,Meteorology ,Atmospheric sciences ,Troposphere ,chemistry.chemical_compound ,Germany ,media_common.cataloged_instance ,Carbon Radioisotopes ,European Union ,European union ,Greenhouse effect ,Radiocarbon analyses ,Ecology, Evolution, Behavior and Systematics ,media_common ,Original Paper ,Air Pollutants ,business.industry ,Fossil fuel ,Carbon offset ,General Medicine ,chemistry ,Carbon dioxide ,Greenhouse gas ,Kyoto protocol ,Environmental science ,Kyoto Protocol ,business - Abstract
The lower troposphere is an excellent receptacle, which integrates anthropogenic greenhouse gases emissions over large areas. Therefore, atmospheric concentration observations over populated regions would provide the ultimate proof if sustained emissions changes have occurred. The most important anthropogenic greenhouse gas, carbon dioxide (CO(2)), also shows large natural concentration variations, which need to be disentangled from anthropogenic signals to assess changes in associated emissions. This is in principle possible for the fossil fuel CO(2) component (FFCO(2)) by high-precision radiocarbon ((14)C) analyses because FFCO(2) is free of radiocarbon. Long-term observations of (14)CO(2) conducted at two sites in south-western Germany do not yet reveal any significant trends in the regional fossil fuel CO(2) component. We rather observe strong inter-annual variations, which are largely imprinted by changes of atmospheric transport as supported by dedicated transport model simulations of fossil fuel CO(2). In this paper, we show that, depending on the remoteness of the site, changes of about 7-26% in fossil fuel emissions in respective catchment areas could be detected with confidence by high-precision atmospheric (14)CO(2) measurements when comparing 5-year averages if these inter-annual variations were taken into account. This perspective constitutes the urgently needed tool for validation of fossil fuel CO(2) emissions changes in the framework of the Kyoto protocol and successive climate initiatives.
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121. Chemical signatures of egg maternity and Dufour's gland in Vespine wasps.
- Author
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da Silva RC, do Nascimento FS, Wenseleers T, and Oi CA
- Subjects
- Humans, Pregnancy, Animals, Female, Reproduction, Fertility, Pheromones chemistry, Hydrocarbons, Wasps physiology
- Abstract
Cuticular hydrocarbons (CHCs) are often used in the chemical communication among social insects. CHCs can be used in nestmate recognition and as queen pheromones, the latter allows the regulation of the reproductive division of labor. In the common wasp Vespula vulgaris, CHCs and egg-marking hydrocarbons are caste-specific, being hydrocarbon queen pheromones and egg maternity signals. Whether these compounds are conserved among other Vespinae wasps remains unknown. Queens, virgin queens, reproductive workers, and workers belonging to four different wasp species, Dolichovespula media, Dolichovespula saxonica, Vespa crabro, and Vespula germanica, were collected and studied. The cuticular hydrocarbons, egg surface, and Dufour's gland composition were characterized and it was found that chemical compounds are caste-specific in the four species. Quantitative and qualitative differences were detected in the cuticle, eggs, and Dufour's gland. Some specific hydrocarbons that were shown to be overproduced in the cuticle of queens were also present in higher quantities in queen-laid eggs and in their Dufour's gland. These hydrocarbons can be indicated as putative fertility signals that regulate the division of reproductive labor in these Vespine societies. Our results are in line with the literature for V. vulgaris and D. saxonica, in which hydrocarbons were shown to be conserved queen signals. This work presents correlative evidence that queen chemical compounds are found not only over the body surface of females but also in other sources, such as the Dufour's gland and eggs., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2023
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122. Erd�l ? Kohle ? Biomassen
- Author
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D. Osteroth
- Subjects
medicine.medical_specialty ,Prima materia ,business.industry ,Carbochemistry ,Biomass ,chemistry.chemical_element ,General Medicine ,Chemical industry ,Raw material ,Pulp and paper industry ,Petroleum product ,chemistry ,medicine ,Environmental science ,Coal ,business ,Carbon ,Ecology, Evolution, Behavior and Systematics - Abstract
Description des differentes possibilites de substitution du petrole par le charbon ou la biomasse. Conclusions pour les developpements a long terme
- Published
- 1987
123. Asbeste Arten, Entstehung, Bedeutung, Problematik
- Author
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Paul Ney
- Subjects
Synthetic fiber ,medicine ,Environmental science ,Nanotechnology ,General Medicine ,Pulp and paper industry ,medicine.disease_cause ,Ecology, Evolution, Behavior and Systematics ,Asbestos cement ,Asbestos - Abstract
Types of asbestos are distinguished not only by structure, chemical compositon, shape of aggregates, and length and quality of fibers, but also by its formation. Though consisting of quite common elements, deposits are formed only under very special conditions. Its unique combination of properties has created over 3000 fields of application (about 70% in asbestos cement). Great efforts have been made to substitute all types of asbestos by harmless, similarly cheap and versatile synthetic fibers, owing to the unquestioned carcinogenic properties of all asbestos dusts. However, development of such fibers has not made any remarkable progress until recently. Consequently risk to workers in mining and manufactoring, consumers, outsiders, and the environment should be kept as low as possible by intensifying precautions and diminishing emissions.
- Published
- 1981
124. Time management and nectar flow: flower handling and suction feeding in long-proboscid flies (Nemestrinidae: Prosoeca)
- Author
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Karolyi, Florian, Morawetz, Linde, Colville, Jonathan F., Handschuh, Stephan, Metscher, Brian D., and Krenn, Harald W.
- Subjects
Original Paper ,Flower handling ,Plant Nectar ,Diptera ,Suction pump ,Feeding Behavior ,Flowers ,Prosoeca ,Suction ,Adaptation, Physiological ,Time ,Nectar feeding ,Animals ,Body Size ,Ecology, Evolution, Behavior and Systematics - Abstract
A well-developed suction pump in the head represents an important adaptation for nectar-feeding insects, such as Hymenoptera, Lepidoptera and Diptera. This pumping organ creates a pressure gradient along the proboscis, which is responsible for nectar uptake. The extremely elongated proboscis of the genus Prosoeca (Nemestrinidae) evolved as an adaptation to feeding from long, tubular flowers. According to the functional constraint hypothesis, nectar uptake through a disproportionately elongated, straw-like proboscis increases flower handling time and consequently lowers the energy intake rate. Due to the conspicuous length variation of the proboscis of Prosoeca, individuals with longer proboscides are hypothesised to have longer handling times. To test this hypothesis, we used field video analyses of flower-visiting behaviour, detailed examinations of the suction pump morphology and correlations of proboscis length with body length and suction pump dimensions. Using a biomechanical framework described for nectar-feeding Lepidoptera in relation to proboscis length and suction pump musculature, we describe and contrast the system in long-proboscid flies. Flies with longer proboscides spent significantly more time drinking from flowers. In addition, proboscis length and body length showed a positive allometric relationship. Furthermore, adaptations of the suction pump included an allometric relationship between proboscis length and suction pump muscle volume and a combination of two pumping organs. Overall, the study gives detailed insight into the adaptations required for long-proboscid nectar feeding, and comparisons with other nectar-sucking insects allow further considerations of the evolution of the suction pump in insects with sucking mouthparts. Electronic supplementary material The online version of this article (doi:10.1007/s00114-013-1114-6) contains supplementary material, which is available to authorized users.
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125. Inhibition of rhythmic neural spiking by noise: the occurrence of a minimum in activity with increasing noise
- Author
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Jürgen Jost, Boris Gutkin, and Henry C. Tuckwell
- Subjects
Dynamical systems theory ,Stochastic resonance ,Models, Neurological ,Action Potentials ,Limit cycle ,Animals ,Statistical physics ,Ecology, Evolution, Behavior and Systematics ,Physics ,Neurons ,Original Paper ,Stochastic Processes ,Inverse stochastic resonance ,Quantitative Biology::Neurons and Cognition ,Stochastic process ,Electric Conductivity ,Neuronal dynamics ,General Medicine ,Critical value ,Hodgkin–Huxley model ,Electrophysiology ,Amplitude ,nervous system ,Potassium ,Nerve Net ,Noise ,Noise (radio) - Abstract
The effects of noise on neuronal dynamical systems are of much current interest. Here, we investigate noise-induced changes in the rhythmic firing activity of single Hodgkin–Huxley neurons. With additive input current, there is, in the absence of noise, a critical mean value µ = µ c above which sustained periodic firing occurs. With initial conditions as resting values, for a range of values of the mean µ near the critical value, we have found that the firing rate is greatly reduced by noise, even of quite small amplitudes. Furthermore, the firing rate may undergo a pronounced minimum as the noise increases. This behavior has the opposite character to stochastic resonance and coherence resonance. We found that these phenomena occurred even when the initial conditions were chosen randomly or when the noise was switched on at a random time, indicating the robustness of the results. We also examined the effects of conductance-based noise on Hodgkin–Huxley neurons and obtained similar results, leading to the conclusion that the phenomena occur across a wide range of neuronal dynamical systems. Further, these phenomena will occur in diverse applications where a stable limit cycle coexists with a stable focus.
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126. Bumblebees exhibit the memory spacing effect
- Author
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James C. Nieh, Jeremy Song, and Nicholas R. T. Toda
- Subjects
0106 biological sciences ,Trial spacing effect ,Plant Nectar ,Bumblebees ,Olfactory conditioning ,Flowers ,Models, Biological ,010603 evolutionary biology ,01 natural sciences ,Proboscis extension reflex ,Bombus impatiens ,Discrimination Learning ,Memory spacing effect ,Reward ,Memory ,Associative learning ,Animals ,0501 psychology and cognitive sciences ,050102 behavioral science & comparative psychology ,Discrimination learning ,Olfactory memory ,Pollination ,Bumblebee ,Ecology, Evolution, Behavior and Systematics ,Life Sciences, general ,Analysis of Variance ,Original Paper ,biology ,Spacing effect ,05 social sciences ,Environment, general ,Life Sciences ,Association Learning ,General Medicine ,Bees ,biology.organism_classification ,Classical conditioning ,Space Perception ,Memory consolidation ,Cognitive psychology - Abstract
Associative learning is key to how bees recognize and return to rewarding floral resources. It thus plays a major role in pollinator floral constancy and plant gene flow. Honeybees are the primary model for pollinator associative learning, but bumblebees play an important ecological role in a wider range of habitats, and their associative learning abilities are less well understood. We assayed learning with the proboscis extension reflex (PER), using a novel method for restraining bees (capsules) designed to improve bumblebee learning. We present the first results demonstrating that bumblebees exhibit the memory spacing effect. They improve their associative learning of odor and nectar reward by exhibiting increased memory acquisition, a component of long-term memory formation, when the time interval between rewarding trials is increased. Bombus impatiens forager memory acquisition (average discrimination index values) improved by 129% and 65% at inter-trial intervals (ITI) of 5 and 3 min, respectively, as compared to an ITI of 1 min. Memory acquisition rate also increased with increasing ITI. Encapsulation significantly increases olfactory memory acquisition. Ten times more foragers exhibited at least one PER response during training in capsules as compared to traditional PER harnesses. Thus, a novel conditioning assay, encapsulation, enabled us to improve bumblebee-learning acquisition and demonstrate that spaced learning results in better memory consolidation. Such spaced learning likely plays a role in forming long-term memories of rewarding floral resources. © 2009 Springer-Verlag.
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127. Social familiarity modulates group living and foraging behaviour of juvenile predatory mites
- Author
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Peter Schausberger and Markus A. Strodl
- Subjects
0106 biological sciences ,Phytoseiidae ,Foraging ,Zoology ,010603 evolutionary biology ,01 natural sciences ,Intraspecific competition ,Predation ,03 medical and health sciences ,Mite ,Juvenile ,Animals ,Life history ,Social Behavior ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,0303 health sciences ,Larva ,Original Paper ,Life Cycle Stages ,Mites ,biology ,Ecology ,Stressor ,General Medicine ,Familiarity ,biology.organism_classification ,Association behaviour ,Predatory Behavior ,Limited attention - Abstract
Environmental stressors during early life may have persistent consequences for phenotypic development and fitness. In group-living species, an important stressor during juvenile development is the presence and familiarity status of conspecific individuals. To alleviate intraspecific conflicts during juvenile development, many animals evolved the ability to discriminate familiar and unfamiliar individuals based on prior association and use this ability to preferentially associate with familiar individuals. Assuming that familiar neighbours require less attention than unfamiliar ones, as predicted by limited attention theory, assorting with familiar individuals should increase the efficiency in other tasks. We assessed the influence of social familiarity on within-group association behaviour, development and foraging of juvenile life stages of the group-living, plant-inhabiting predatory mite Phytoseiulus persimilis. The observed groups consisted either of mixed-age familiar and unfamiliar juvenile mites or of age-synchronized familiar or unfamiliar juvenile mites or of pairs of familiar or unfamiliar larvae. Overall, familiar mites preferentially grouped together and foraged more efficiently, i.e. needed less prey at similar developmental speed and body size at maturity, than unfamiliar mites. Preferential association of familiar mites was also apparent in the inter-exuviae distances. Social familiarity was established by imprinting in the larval stage, was not cancelled or overridden by later conspecific contacts and persisted into adulthood. Life stage had an effect on grouping with larvae being closer together than nymphal stages. Ultimately, optimized foraging during the developmental phase may relax within-group competition, enhance current and future food supply needed for optimal development and optimize patch exploitation and leaving under limited food.
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128. Revisiting chronodisruption: when the physiological nexus between internal and external times splits in humans.
- Author
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Erren, Thomas and Reiter, Russel
- Abstract
In this Concepts & Synthesis paper, we expand the definition of chronodisruption in humans by proposing that it can be operationalized as the split nexus of internal and external times. With this premise, we suggest how chronotype may be used as a temporal marker (chronomarker) of exposure to chronodisruption in studies of cancer, and beyond, offer cancer risk predictions for observational research on the basis of a chronotype-related hypothesis and corollary, and point to first empirical data in humans. In an a priori way, we examine possible outcomes and perspectives for preventive measures following from our rationale and the suggested chronobiology-driven studies and close with overall advances of chronodisruption research. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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129. Costs of female odour in males of the parasitic wasp Lariophagus distinguendus (Hymenoptera: Pteromalidae).
- Author
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Joachim Ruther and Sven Steiner
- Abstract
Abstract The display of female traits by males is widespread in the animal kingdom. In several species, this phenomenon has been shown to function adaptively as a male mating strategy to deceive sexual rivals (female mimicry). Freshly emerged males of the parasitic wasp Lariophagus distinguendus (Hymenoptera: Pteromalidae) are perceived by other males as if they were females because of a very similar composition of cuticular hydrocarbons which function as a sex pheromone in this species inducing courtship behaviour in males. Within 32 h, however, males deactivate the pheromone and are no longer courted by other males. In this paper, behavioural experiments were performed to test hypotheses on potential costs and benefits associated with the female odour in young males. We did not find any benefits, but demonstrated that young males were significantly more often outrivaled in male–male contests when competing with two older males for a female. Also, young males were significantly more often mounted in homosexual courtship events during these contests. Thus, display of female traits by males is not necessarily beneficial, and in fact, can be disadvantageous. We suggest that these costs have favoured the evolution of the pheromone deactivation mechanism in L. distinguendus males. The function of cuticular hydrocarbons as a female courtship pheromone in L. distinguendus might have evolved secondarily from a primary function relevant for both genders, and the deactivation of the signal in males might have caused a shift of specificity of the chemical signal from the species level to the sex level. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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130. New fossil ants in French Cretaceous amber (Hymenoptera: Formicidae).
- Author
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Vincent Perrichot, André Nel, Didier Néraudeau, Sébastien Lacau, and Thierry Guyot
- Abstract
Abstract Recent studies on the ant phylogeny are mainly based on the molecular analyses of extant subfamilies and do not include the extinct, only Cretaceous subfamily Sphecomyrminae. However, the latter is of major importance for ant relationships, as it is considered the most basal subfamily. Therefore, each new discovery of a Mesozoic ant is of high interest for improving our understanding of their early history and basal relationships. In this paper, a new sphecomyrmine ant, allied to the Burmese amber genus Haidomyrmex, is described from mid-Cretaceous amber of France as Haidomyrmodes mammuthus gen. and sp. n. The diagnosis of the tribe Haidomyrmecini is emended based on the new type material, which includes a gyne (alate female) and two incomplete workers. The genus Sphecomyrmodes, hitherto known by a single species from Burmese amber, is also reported and a new species described as S. occidentalis sp. n. after two workers remarkably preserved in a single piece of Early Cenomanian French amber. The new fossils provide additional information on early ant diversity and relationships and demonstrate that the monophyly of the Sphecomyrminae, as currently defined, is still weakly supported. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
131. Biomimetics and the case of the remarkable ragworms.
- Abstract
Abstract  Biomimetics is a rapidly growing field both as an academic and as an applied discipline. This paper gives a short introduction to the current status of the discipline before it describes three approaches to biomimetics: the mechanism-driven, which is based on the study of a specific mechanism; the focused organism-driven, which is based on the study of one function in a model organism; and the integrative organism-driven approach, where multiple functions of a model organism provide inspiration. The first two are established approaches and include many modern studies and the famous biomimetic discoveries of Velcro and the Lotus-Effect, whereas the last approach is not yet well recognized. The advantages of the integrative organism-driven approach are discussed using the ragworms as a case study. A morphological and locomotory study of these marine polychaetes reveals their biomimetic potential, which includes using their ability to move in slippery substrates as inspiration for novel endoscopes, using their compound setae as models for passive friction structures and using their three gaits, slow crawling, fast crawling, and swimming as well as their rapid burrowing technique to provide inspiration for the design of displacement pumps and multifunctional robots. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
132. Biomolecules preserved in ca. 168 million year old fossil conifer wood.
- Author
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Leszek Marynowski, Angelika Otto, MichaÅ ZatoÅ, Marc Philippe, and Bernd Simoneit
- Abstract
Abstract??Biomarkers are widely known to occur in the fossil record, but the unaltered biomolecules are rarely reported from sediments older than Paleogene. Polar terpenoids, the natural products most resistant to degradation processes, were reported mainly from the Tertiary conifers, and the oldest known are Cretaceous in age. In this paper, we report the occurrence of relatively high concentrations of ferruginol derivatives and other polar diterpenoids, as well as their diagenetic products, in a conifer woodProtopodocarpoxylonfrom the Middle Jurassic of Poland. Thus, the natural product terpenoids reported in this paper are definitely the oldest polar biomolecules detected in geological samples. The extracted phenolic abietanes like ferruginol and its derivatives (6,7-dehydroferruginol, sugiol, 11,14-dioxopisiferic acid) are produced only by distinct conifer families (Cupressaceae s. l., Podocarpaceae and Araucariaceae), to whichProtopodocarpoxyloncould belong based on anatomical characteristics. Therefore, the natural product terpenoids are of great advantage in systematics of fossil plant remains older than Paleogene and lacking suitable anatomical preservation. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
133. Prehibernating aggregations of Polistes dominulus: an occasion to study early dominance assessment in social insects.
- Author
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Leonardo Dapporto, Elisabetta Palagi, Alessandro Cini, and Stefano Turillazzi
- Abstract
At a very early age several mammals establish a first dominance hierarchy, which often persists into adulthood. Social wasps offer an excellent opportunity to study such a phenomenon in insects. Indeed, foundresses of several paper wasps meet in clusters to hibernate from September to March. In spring, wasps found new associative nests where linear hierarchies occur. In the first phase of hibernation, clustering Polistes dominulus wasps show most of the social interactions occurring on the nest 6 months later. At the emergence from diapause, some females already show some behavioral and physiological traits typical of dominant individuals. Here, we investigated the significance of the interactions in the autumnal clusters. We demonstrated that in a given pair, it is more likely that the dominant wasp in autumn becomes the alpha female in spring after the nest foundation phase occurred. Moreover, we showed that dominant females in clusters have both larger body size and ovaries. As ovarian development mainly depends on the social context, our findings seem to indicate that social factors affect the tendency to dominate in aggregations. Furthermore, we suggest that some females may reinforce their physiological status by dominating in clusters, thus increasing the probability to become dominant in spring. [ABSTRACT FROM AUTHOR]
- Published
- 2006
134. The role of moisture in the nest thermoregulation of social wasps.
- Author
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R. Klingner, K. Richter, E. Schmolz, and B. Keller
- Abstract
Paper nests of social wasps are intriguing constructions for both, biologists and engineers. We demonstrate that moisture and latent heat significantly influence the thermal performance of the nest construction. Two colonies of the hornet Vespa crabro were investigated in order to clarify the relation of the temperature and the moisture regime inside the nest. Next to fairly stable nest temperatures the hornets maintain a high relative humidity inside the nest. We found that in consequence a partial vapor-pressure gradient between nest and ambient drives a constant vapor flux through the envelope. The vapor flux is limited by the diffusion resistance of the envelope. The driving force of vapor flux is heat, which is consumed through evaporation inside the nest. The colony has to compensate this loss with metabolic heat production in order to maintain a stable nest temperature. However, humidity fluctuations inside the nest induce circadian adsorption and desorption cycles, which stabilize the nest temperature and thus contribute significantly to temperature homeostasis. Our study demonstrates that both mechanisms influence nest thermoregulation and need to be considered to understand the thermodynamic behavior of nests of wasps and social insects in general. [ABSTRACT FROM AUTHOR]
- Published
- 2005
135. A new test of random walks in heterogeneous environments.
- Author
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M. Challet, V. Fourcassié, S. Blanco, R. Fournier, G. Theraulaz, and C. Jost
- Abstract
Environmental heterogeneities can change animal movement in two different manners. First, they can modify movement characteristics (move lengths or turning angles), in which case the movement remains of the diffusive kind. Second, they can bias displacement towards a particular direction in which case it becomes non-diffusive. We propose in this paper a simple method that only requires computing the mean length of a sample of trajectories in some bounded area to distinguish between these two kinds of movement. We show through simulations that the method allows to detect the presence of heterogeneities that orient animal movement. We apply it to experimental trajectories of Messor sancta ants engaged in corpse aggregation to show that their displacement is oriented at the contact of the formed corpse piles and that their trajectories become non-diffusive. [ABSTRACT FROM AUTHOR]
- Published
- 2005
136. Autopoiesis: a review and a reappraisal.
- Author
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Luisi, Pier Luigi
- Abstract
The aim of the paper is to review critically the notion of autopoiesis as presented by Maturana and Varela. In particular, recognizing that there are difficulties in obtaining a complete and clear picture from the primary literature, an effort is made to present a coherent view—also based on many years of personal contact with Francisco Varela. The paper begins with a few historical notes to highlight the cultural background from which the notion of autopoiesis arose. The basic principles of autopoiesis as a theory of cellular life are then described, emphasizing also what autopoiesis is not: not an abstract theory, not a concept of artificial life, not a theory about the origin of life—but rather a pragmatic blueprint of life based on cellular life. It shown how this view leads to a conceptually clear definition of minimal life and to a logical link with related notions, such as self-organization, emergence, biological autonomy, auto-referentiality, and interactions with the environment. The perturbations brought about by the environment are seen as changes selected and triggered by the inner organization of the living. These selective coupling interactions impart meaning to the minimal life and are thus defined by Maturana and Varela with the arguable term of "cognition". This particular view on the mutual interactions between living organism and environment leads these authors to the notion of "enaction", and to the surprising view that autopoiesis and cognition are two complementary, and in a way equivalent, aspects of life. It is then shown how cognition, so defined, permits us to build a bridge between biology and cognitive science. Autopoiesis also allows one to conceive chemical models of minimal cellular life that can be implemented experimentally. The corresponding work on "chemical autopoiesis" is then reviewed. The surprising impact of autopoiesis in the social sciences ("social autopoiesis") is also briefly discussed. This review also comments on why the theory of autopoiesis had, and still has, a difficult time being accepted into the mainstream of life-science research. Finally, it is pointed out that the new interest in system biology and complexity theories may lead to a reappraisal of autopoiesis and related notions, as outlined also by other authors, such as Tibor Ganti and Stuart Kauffmann. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
137. Color choice behavior in cats and the effect of changes in the color of the illuminant.
- Author
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Tritsch, M.
- Published
- 1993
- Full Text
- View/download PDF
138. Untitled.
- Author
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Kurz, Stefan, Becker, Ulrich, and Maisch, Harald
- Abstract
This paper describes the state-of-the-art of dynamic simulation of electromechanical systems. Electromechanical systems can be split into electromagnetic and mechanical subsystems, which are described by Maxwell's equations and by Newton's law, respectively. Since such systems contain moving parts, the concepts of Lorentz and Galilean relativity are briefly addressed. The laws of physics are formulated in terms of (partial) differential equations. Numerical methods ultimately aim at linear systems of equations, which can be solved efficiently on digital computers. The various discretization methods for performing this task are discussed. Special emphasis is placed on domain decomposition as a framework for the coupling of different numerical methods such as the finite element method and the boundary element method. The paper concludes with descriptions of some applications of industrial relevance: a high performance injection valve and an electromechanical relay. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
139. Untitled.
- Author
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Detrain, Natan, and Deneubourg
- Abstract
Among social insects such as ants, scouts that modulate their recruiting behaviour, following simple rules based on local information, generate collective patterns of foraging. Here we demonstrate that features of the abiotic environment, specifically the foraging substrate, may also be influential in the emergence of group-level decisions such as the choice of one foraging path. Experimental data and theoretical analyses show that the collective patterns can arise independently of behavioural changes of individual scouts and can result, through self-organising processes, from the physico-chemical properties of the environment that alter the dynamics of information transfer by chemical trails. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
140. The brain as a photoreceptor: intracerebral ocelli in the firefly.
- Author
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Hariyama, T.
- Abstract
This paper deals with the structure and function of the intracerebral ocelli in the caudal area of the brain of the Japanese firefly. A pair of epilaterally placed specialized pigmented organs was found at the caudal ends of the brains of the fireflies Luciola cruciata and L. lateralis. On the basis of light and transmission electron micrographs of both male and female individuals these organs seemed photoreceptive in nature. Intracellular and extracellular recordings were obtained from the intracerebral ocelli of the fireflies with microelectrodes. The physiological evidence revealed that the cells found in the brain were, indeed, photoreceptors. [ABSTRACT FROM AUTHOR]
- Published
- 2000
- Full Text
- View/download PDF
141. The adaptive function of ammonia and guanine in the biocoenotic association between ascomycetes and flour mites ( Acarus siro L.).
- Author
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Levinson, H., Levinson, A., and Müller, K.
- Published
- 1991
- Full Text
- View/download PDF
142. Accumulation of linear alkylbenzenesulphonate surfactants in sewage sludges
- Author
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W. Giger and J. McEvoy
- Subjects
Chromatography ,Chemistry ,business.industry ,Sewage ,General Medicine ,Pulp and paper industry ,business ,Ecology, Evolution, Behavior and Systematics ,Sludge - Published
- 1985
143. Geographic Affinity, Cuticular Hydrocarbons and Colony Recognition in the Australian Meat Ant Iridomyrmex purpureus.
- Author
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Thomas, Melissa L., Parry, Laura J., Allan, Rachel A., and Elgar, Mark A.
- Published
- 1999
- Full Text
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144. A novel concept of Fe-mineral-based magnetoreception: histological and physicochemical data from the upper beak of homing pigeons
- Author
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Fleissner, Gerta, Stahl, Branko, Thalau, Peter, Falkenberg, Gerald, and Fleissner, Günther
- Published
- 2007
- Full Text
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145. Cosmological implications of the Machian principle
- Author
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Fahr, Hans J. and Zoennchen, Jochen H.
- Published
- 2006
- Full Text
- View/download PDF
146. Squeezing light out of crystals: Triboluminescence.
- Author
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Zink, Jeffrey
- Abstract
Triboluminescence is the light emitted when mechanical energy is applied to a crystal. Many common substances such as sugar and copper sulfate are triboluminescent. The origin of the light and the mechanical, chemical, and crystallographic requirements of the phenomenon are described in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 1981
- Full Text
- View/download PDF
147. Cercaricidal activity of some essential oils of plants from Brazil.
- Author
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Frischkorn, C., Frischkorn, H., and Carrazzoni, E.
- Abstract
Extended screening tests on the cercaricidal activity of various plants from northeast Brazil have shown that the extracts of the leaves and fruits of Piper marginatum, Protium heptaphyllum, and Capsicum annuum show a remarkable effect on the cercaria of Schistosoma mansoni. In the case of the oils of Piper marginatum and Capsicum annuum, 90-96% of the cercaria of Schistosoma mansoni were killed within 15 min. According to the NMR spectra, the active principles of the extracts seem to be water-soluble unsaturated compounds from the oils or their hydrolysis products. Natural substances provide an attractive alternative for preventive actions against schistosomiasis, as the perturbation of the ecological equilibrium of natural waters can be avoided in this manner. [ABSTRACT FROM AUTHOR]
- Published
- 1978
- Full Text
- View/download PDF
148. Functional importance of the mandibular skeleto-muscular system in the bivalved arthropod Heterocypris incongruens (Crustacea, Ostracoda, Cyprididae).
- Author
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Yamada S
- Subjects
- Animals, Biological Evolution, Crustacea physiology, Humans, Mandible anatomy & histology, Arthropods physiology, Bivalvia
- Abstract
Arthropods with a pair of mandibles (Mandibulata) emerged by the end of the Cambrian period. The mandible is one of the apomorphic characteristics of this monophyletic clade, which is composed of Pancrustacea and Myriapoda. Acquisition of the mandible is one of the important events of the evolutionary pathway of arthropods because the powerful masticatory system provides benefits to individuals regarding food selection. Ancestral mandibulates are well known as so-called Cambrian bivalved arthropods, and a few of them provide a pair of valid mandibles with a broad molar process. However, extant bivalved arthropods can only be found in a few lineages of crustaceans, though all of them are equipped with mandibles. This study focuses on the neuroanatomy of the mandibular skeleto-muscular system of Heterocypris incongruens (Ostracoda, Crustacea), a millimeter-sized bivalved crustacean. Electron microscopy reveals that numerous mechanoreceptive sensilla are distributed inside the mandibular gnathal edges and that there are two types (heterodynal and monodynal) of sensilla, which differ in the number of dendrites and their probable function. This sensory nervous system in the gnathal edges contributes to the precise interdigitation of the right and left mandibles to allow for powerful omnivorous mastication, and the mandibular interdigitation plays a role as the fulcrum of triggering action to open the valves. Therefore, by reversing its fulcrum and load, the mandibular skeleto-muscular system in podocopid ostracods has two sub-systems with different functions, namely the "mandibular masticatory system" and the "valve opening system." Furthermore, this investigation provides significant information on the feeding mode of Cambrian bivalved arthropods, from the view of the functional morphology of the mandibular skeleto-muscular system., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2022
- Full Text
- View/download PDF
149. Prey-rolling behavior of coatis (Nasua spp.) is elicited by benzoquinones from millipedes.
- Author
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Paul Weldon, Catherine Cranmore, and Jenifer Chatfield
- Abstract
Coatis (Nasua spp.), gregarious, omnivorous carnivores that range in forests from the southwestern USA to south America, dispatch millipedes by rolling them on the ground using rapid, alternating movements of their forepaws. Prey rolling of millipedes is thought to stimulate the depletion of their defensive secretions and to wipe off secretions before millipedes are consumed. We report that prey-rolling behavior in Nasua spp. is elicited by 1,4-benzoquinone; 2-methyl-1,4-benzoquinone; and 2-methoxy-3-methyl-1,4-benzoquinone, the chief components of the defensive secretions of julidan, spirobolidan, and spirostreptidan millipedes. Chemicals elaborated for defense sometimes evolutionarily “backfire,” providing cues to predators on the presence or identity of prey. The elicitation of prey-rolling behavior in Nasua spp. by benzoquinones illustrates this effect for millipedes (and possibly other arthropods) that defensively discharge these compounds. [ABSTRACT FROM AUTHOR]
- Published
- 2006
150. Trail laying during tandem-running recruitment in the ant Temnothorax albipennis.
- Author
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Basari, Norasmah, Laird-Hopkins, Benita, Sendova-Franks, Ana, and Franks, Nigel
- Abstract
Tandem running is a recruitment strategy whereby one ant leads a single naïve nest mate to a resource. While tandem running progresses towards the goal, the leader ant and the follower ant maintain contact mainly by tactile signals. In this paper, we investigated whether they also deposit chemical signals on the ground during tandem running. We filmed tandem-running ants and analysed the position of the gasters of leaders and followers. Our results show that leader ants are more likely to press their gasters down to the substrate compared to follower ants, single ants and transporter ants. Forward tandem-run leaders (those moving towards a new nest site) performed such trail-marking procedures three times more often than reverse tandem leaders (those moving towards an old nest site). That leader ants marked the trails more often during forward tandem runs may suggest that it is more important to maintain the bond with the follower ant on forward tandem runs than on reverse tandem runs. Marked trails on the ground may serve as a safety line that improves both the efficiency of tandem runs and their completion rates. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
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