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1402. Do sexually dimorphic glands in the harvestman Gryne perlata (Arachnida: Opiliones) release contact pheromones during mating?

Creator:
Dias, Jéssica M. and Willemart, Rodrigo H.
Format:
print, počítač, and online zdroj
Type:
article, články, journal articles, model:article, and TEXT
Subject:
Zoologie, pavoukovci, sekáči, arachnids, Opiliones, Arachnida, Laniatores, Cosmetidae, Gryne perlata, Gonyleptidae, Discocyrtus pectinifemur, chemical communication, copulation, sexually dimorphic glands, 2, and 59
Language:
English
Description:
There are records of glands that produce sexual pheromones that are released into the environment or applied directly on sexual partners. Within Opiliones (Arachnida), several harvestmen in the suborder Laniatores have sexually dimorphic glands on legs I and IV, the mode of use of which is recorded only in two species but their function is unknown: while walking, males rub the glands against the substrate or against their body. Here we test an alternative and non-exclusive hypothesis that the glands present on the legs of male Gryne perlata (Cosmetidae) produce contact pheromones used in mating. We predicted that males would touch the females with the gland openings or with other male body parts previously rubbed by these glands. We also predicted that there are chemoreceptors on those parts of the females where males touch them. We analyzed 13 videos of G. perlata mating, a species in which the males have glands on legs I and IV of unknown function. We also analyzed 14 videos of Discocyrtus pectinifemur (Gonyleptidae) mating as a control, a species that lacks these glands. Finally, we looked for chemoreceptors on the legs of female G. perlata using a scanning electron microscope. During copulation, males of both species rubbed the legs of females with their first pair of legs, but not with the regions of these legs where the openings of the glands are. The fourth pair of legs were only used to support the body. Rubbing other body parts of the female by males with their glands was not observed during mating. Setae on the legs of the female did not have tip pores and therefore do not seem to be chemoreceptors. We therefore did not find any evidence that these sexually dimorphic glands in G. perlata release contact pheromones during mating., Jéssica M. Dias, Rodrigo H. Willemart., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1403. Do the arthropod communities on a parasitic plant and its hosts differ?

Creator:
Lázaro-González, Alba, Hódar, José A., and Zamora, Regino
Format:
print, počítač, and online zdroj
Type:
article, články, journal articles, model:article, and TEXT
Subject:
Zoologie, jmelí bílé, borovice, polokřídlí, Viscum album, Pinus, Hemiptera, Mistletoe, hemiparasitic plant, pine host, arthropod communities, specialist insect, Cacopsylla visci, Pinalitus viscicola, Anthocoris visci, 2, and 59
Language:
English
Description:
Parasitic plants growing on tree branches may be a novel niche and phytoresource for arthropods. The spatial continuity between hosts and their parasites in canopies might provide a homogeneous environment for arthropod communities, but differences in mistletoe leaves and host needles could be exploited by different species of arthropods. Therefore, it is important to determine insect-community assemblages in order to discover the role of parasitic plants as a different habitat for arthropods. Thus, we aim to evaluate the level of similarity between the arthropod community on mistletoe (Viscum album) and that on its two principal pine hosts, Black pine (Pinus nigra) and Scots pine (P. sylvestris), on a Mediterranean mountain. Our results reveal that, irrespective of the species of pine host, V. album has a stable, independent and simple arthropod trophic web, composed mainly of two specialist hemipteran herbivores, Cacopsylla visci (Psyllidae) and Pinalitus viscicola (Miridae), and a hemipteran predator, Anthocoris visci (Anthocoridae). Despite this, the composition of the arthropod communities differed significantly on both host species, with a greater richness and diversity on Scots than Black pine and these differences are not reflected in the community on mistletoe. Overall, we conclude that, although Viscum album is considered to be a pest of pine, its presence increases the heterogeneity of the forest canopy by providing a novel habitat for a new and specific community of arthropods. In addition, this is a new record for and most probably an extension of the southernmost limit of the known geographical distribution of the arthropod community inhabiting V. album., Alba Lázaro-González, José A. Hódar, Regino Zamora., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1404. Do the Oscillations of Cardiovascular Parameters Persist during Voluntary Apnea in Humans?

Creator:
Michal Javorka, Ivan Žila, Kamil Javorka, and Andrea Čalkovská
Format:
print, bez média, and svazek
Type:
article, studie, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, Apnea, Respiratory sinus arrhythmia, Heart rate, Blood pressure, Oscillations, 14, and 612
Language:
English
Description:
The aim of this study was to ascertain the persistence of heart rate and blood pressure oscillations at the onset of voluntary apnea in humans and to assess the dependence of the fluctuations` parameters on the chemoreceptor activity. In 24 young subjects (10 males, 14 females, mean age 20.4 years) heart rate (represented by its reciprocal value - RR-intervals), systolic blood pressure (SBP) and diastolic blood pressure (DBP) during controlled breathing (CB) of atmospheric air and oxygen followed by apnea were recorded continuously. The cosine functions were then fitted by nonlinear regression analysis to the heart rate, SBP and DBP oscillations during CB and at the onset of apnea. The parameters of oscillations were different during atmospheric air breathing compared to oxygen breathing. During oxygen breathing there was an increase of the RR-interval oscillations - relative bradycardia and enhanced magnitude of respiratory sinus arythmia. During apnea, the base level of the blood pressure oscillations was higher after breathing of atmospheric air compared o oxygen breathing. At least one cosine-like wave oscillation was present at the onset of apnea in the heart rate, SBP and DBP and the second wave was present in all assessed parameters in at least 70 % of recordings. The oscillations in RR-intervals are, to some extent, independent of blood pressure oscillations. No significant gender differences were found either in the duration of breath holding or in the RR and SBP oscillations parameters., M. Javorka, I. Žila, K. Javorka, A. Čalkovská., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1405. Do vesmíru chci létat i nadále

Creator:
Svoboda, Luděk
Format:
print
Type:
article, články, model:article, and TEXT
Subject:
Věda. Všeobecnosti. Základy vědy a kultury. Vědecká práce, Feustel, Andrew J, 1965-, Akademie věd České republiky, kosmonauti, astronauts, 12, and 00
Language:
Czech
Description:
The American astronaut, Andrew Feustel, who took "Krtek" (the Little Mole), the cartoon character created by the Czech animator Zdeněk Miler, into space with him aboard the Endeavour space shuttle last May, completed a visit to the Czech Republic during which he promoted science and technology among young Czechs. The Academy of Sciences of the Czech Republic, which invited Feustel to Prague, awarded him the Honorary Medal "De Scientia Et Humanitate Optime Meritis" for propagating science and research. He is the third American astronatu, after John Blaha and Eugene Cernan, to have a Czech connection, his wife Indira's mother, having been born in Znojmo. This was the second time Feustel took something "Czech" with him into space. On his first mission in May 2009, he brought along a book of poems entitled Cosmic Songs by the Czech writer Jan Neruda. and Luděk Svoboda.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

1406. Do vysokohoří jihovýchodní Brazílie - campos de altitude

Creator:
Miloslav Studnička
Format:
print
Type:
article, články, journal articles, model:article, and TEXT
Subject:
Obecná botanika, vysokohorská rostlinná společenstva, botanika, životní prostředí, alpine plant communities, botany, environment, Brazílie, Brasil, 2, and 581
Language:
Czech
Description:
Z geobotanického hlediska je popsána subalpinská a alpinská vegetace v horách jihovýchodní Brazílie. Přirozené požáry tam ovlivňují strukturu rostlinných společenstev. Jsou zmíněny zajímavé životní způsoby, jako je mykorhiza, hemiparazitismus a masožravost. Jedním z nejzajímavějších fenomenů je symbióza mezi masožravou rostlinou Utricularia cornigera (bublinatkou růžkatou) a růžicovitými rostlinami Vriesea atra nebo Eryngium fluminense. Je diskutováno o problému srovnávání popsané brazilské vegetace a páramos v Andách. Pojem "brazilská páromos" je odmítnut., The subalpine and alpine vegetation in mountains of south-eastern Brazil is described from the botanical point of view. Natural fires affect the structure of plant communities there. Interesting life strategies, such as mycorrhiza, hemiparasitism and carnivory, are mentioned. One of the most interesting is the symbiosis between carnivorous Utricularia cornigera and rosette plants of Vriesea atra or Eryngium fluminense. Brazilian vegetation and páramos in the Andes are compared., and Miloslav Studnička.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1407. Dobrá kniha určitě stojí za úsilí

Creator:
Štefániková, Gabriela, Marina Hužvárová, and Martin Steiner
Format:
print
Type:
article, rozhovory, model:article, and TEXT
Subject:
Věda. Všeobecnosti. Základy vědy a kultury. Vědecká práce, Akademie věd České republiky, knihy, vydavatelská činnost, books, publishing, 12, and 00
Language:
Czech
Description:
Gabriela Štefániková, Marina Hužvárová.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

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