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62. Echolokace a hlasové projevy rejskovitých hmyzožravců. I. Orientace v prostoru a seismické vibrace

Creator:
Schneiderová, Irena
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Biologické vědy, rejskovití, Soricidae, Česko, Czechia, orientace v prostoru, orientace v prostředí, echolokace, bělozubky, akustické monitorování, vnitrodruhová komunikace, dorozumívání zvířat, seismické vibrace, echolocation, Crocidurinae, 2, and 57/59
Language:
Czech
Description:
Rejskovití hmyzožravci (čeleď Soricidae) jsou drobní savci, kterých si v přírodě často sotva všimneme. Vyznačují se však mnoha zajímavostmi, díky kterým rozhodně stojí za naši pozornost. K těmto zajímavostem lze zařadit i schopnost echolokace, tj. schopnost orientovat se v prostoru za pomoci ozvěn cvakání, které vydávají. Kromě cvakání se během pohybu prostředím patrně orientují i pomocí štěbetavých hlasů. Bělozubky hnědé (Suncus murinus) při pohybu v neznámém prostředí také „duní“. Zda se i toto dunění uplatňuje při orientaci v prostoru není zatím jasné. Bělozubky pouštní (Diplomesodon pulchellum) zase při přechodu mezi různými typy substrátu vibrují, a tyto vibrace vytvářené celým tělem jim pravděpodobně pomáhají odhadnout vlastnosti substrátu a vyhnout se tak zbytečnému hrabání v hustém písku., Shrews (Soricidae) are small mammals that can be barely noticed in nature. However, there are many interesting facts that make them noteworthy, including echolocation - the ability to navigate with the help of echoes of the clicks they produce. Apart from the clicks, twitters are also probably used for navigation. The Asian House Shrew (Suncus murinus) moving through an unfamiliar environment produces boom, but it is not yet clear whether this sound is used for navigation. The Piebald Shrew (Diplomesodon pulchellum) produces body vibrations in response to a change in the substrate under their feet. These vibrations may be used for exploration of substrate density to avoid digging in dense sand., and Irena Schneiderová.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

63. Echolokace a hlasové projevy rejskovitých hmyzožravců. II. Vnitrodruhová komunikace a ontogeneze hlasového repertoáru

Creator:
Schneiderová, Irena
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Biologické vědy, rejskovití, hmyzožravci, ontogeneze živočichů, Soricidae, insectivores, animal ontogeny, 2, and 57/59
Language:
Czech
Description:
Rejskovití hmyzožravci (Soricidae) vydávají v nejrůznějších situacích mnoho typů hlasů. Dospělí jedinci se ozývají, pokud jsou v nebezpečí nebo se dostanou do potyčky s jiným jedincem svého druhu, během námluv a páření nebo při kontaktu s potomky. Také mláďata vydávají nejrůznější hlasy, jimiž se často snaží upozornit na své strádání nebo udržet kontakt s matkou a sourozenci. Přestože v poslední době přibývá publikací zabývajících se problematikou akustické komunikace rejskovitých, je to stále poměrně neprobádaná oblast. Mnohé otázky by mohly být zodpovězeny studiem bělozubky hnědé (Suncus murinus), která dobře prospívá i v péči člověka., Shrews (Soricidae) utter many types of vocalization in various situations. Adult individuals emit vocalizations when they are in danger or in a fight with conspecifics, during courtship and mating or when they keep contact with their offspring. Juveniles utter variable vocalizations mostly to prevent their discomfort and to keep contact with their mother and siblings. Although the number of publications has increased recently, acoustic communica­tion among shrews still remains a quite unexplored field. Our knowledge might be significantly expanded by studying the Asian House Shrew (Suncus murinus), a species that can be successfully kept and bred in captivity., and Irena Schneiderová.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

64. Effects of 5-hydroxytryptamine on the short-circuit current across the small intestine of the gerbil (Gerbillus cheesmani) in different dietary states

Creator:
Al-Balool, F. Y.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Biologické vědy, fyziologie živočichů, pískomilové, hladovění, zkratový, animal physiology, gerbils, starvation, malnutrition, 5-hydroxytryptamin, tetrodotoxin, short circuit-current, 2, and 57/59
Language:
English
Description:
The effects of serosally added 5-hydroxytryptamine (5-HT, 100 μM) on the short circuit-current (Isc) across jejunum and ileum taken from fed, starved and undernourished (Gerbillus cheesmani) were investigated. The effects of the neurotoxin, tetrodotoxin (TTX, 10 μM) on the basal Isc as well as on the maximum increase in Isc induced by 5-HT were also studied. There were regional variations in the basal Isc as well as in the way by which the small intestine responds to 5-HT. The basal Isc was greater in jejunum than in ileum and such differences were TTX-sensitive. The maximum increase in Isc, which results from addition of 5-HT, was higher in jejunum than in ileum under all three feeding conditions. TTX reduced the maximum increase in Isc induced by 5-HT across stripped and intact intestine of the two regions in the three nutritional states. The 5-HT-induced Isc in the jejunum of both starved and undernourished gerbils and in the ileum of starved animals was the function of both submucosal and myenteric plexus. In jejunum and ileum taken from starved and undernourished gerbils the 5-HT-induced Isc was both chloride- and bicarbonate-dependent. Thus the results indicated that both starvation and undernourishment increase that response and such increases were TTX-sensitive and both chloride- and bicarbonate-dependent., F. Y. Al-Balool., and Obsahuje bibliografii a bibliografické odkazy
Rights:
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65. Effects of Organophosphate Insecticides on Mechanical Properties of Rat Aorta

Creator:
Guvenc Tuna, B., Ozturk, N., Comelekoglu, U., and Yilmaz, B. C.
Type:
article, články, model:article, and TEXT
Subject:
Biologické vědy, fyziologie, physiology, chlorpyriphos, dichlorvos, aorta, stress, elastic modulus, 2, and 57/59
Language:
English
Description:
The present study was carried out to search whether organophosphate pesticides affect the mechanical properties of the thoracic aorta. Wistar fema le rats (aged 6-8 weeks) were assigned randomly to a control group and groups treated with either dichlorvos or chlorpyriphos for 90 days at a dose of 5 mg/kg/day. After that period, animals were killed and thoracic aorta strips in longitudinal direction were isolated. The stress, strain and elastic modulus were obtained from the strips. Our results showed that chronic administration of chlorpyriphos and dichlorvos caused downward shift of the stress-strain relations compared to the control curve. The elastic modulu s-stress curve revealed distinct characterist ics in the low and high stress regions. A power function was used to simulate the low stress region while a line was fit to the high stress region. Curve fitting procedure illustrated that both pesticides influenced mainly the high stress region, but they had diverse effects at the low stress region. The results also imply that chlorpyriphos and dichlorvos decrease the strength of the aorta and therefore might influence the response of the aorta to mechanical loading induced by blood pressure. and B. Guvenc Tuna ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

66. Effects of shoot girdling on photosynthetic capacity, leaf carbohydrate, and bud abscission in pistachio (Pistacia vera L.)

Creator:
Vemmos, S. N., Papagiannopoulou, A., and Coward, S.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
biologie, biology, areal leaf mass, biennial bearing, chlorophyll, net photosynthetic rate, nitrogen, starch, stomatal conductance, sugars, 2, and 57/59
Language:
Multiple languages
Description:
The effects of shoot girdling on stomatal conductance (gs), leaf photosynthesis (PN), concentrations of carbohydrates, nitrogen and chlorophyll (Chl) in leaves, areal leaf mass (ALM), the diameter and length of shoots, and bud abscission in pistachio were investigated. Girdling individual shoots at the base of the current year’s shoot (girdle I), separating inflorescent buds on the terminal current year’s shoot from the developing fruits on the previous year’s shoot, reduced inflorescent bud abscission by 70% in comparison to nongirdled controls. Girdle I significantly reduced concentrations of nitrogen in leaves but increased those of nonstructural carbohydrates particularly of starch. Shoot diameter increased by 13.1% and 26.4% at 33 and 81 days after girdling (DAG), respectively, compared to 1% and 3.4% in the control, respectively. Both the leaf dry mass/fresh mass ratio and ALM were increased significantly by girdle I from 12 DAG. The concentrations of Chl a, Chl b, Chl (a+b), as well as the ratio of Chl a/b, all decreased with girdle I. The greatest negative effect of girdle I was on gs and PN. PN was reduced by 55% of its initial value and was 44% less than in the control leaves at 10 DAG, and fell to approximately 30% that of the control from 21 DAG. In contrast, girdling at the base of one-year-old shoots (girdle II), thus not separating fruits from the inflorescent buds, did not significantly affect gs or PN. The effect of girdling on PN and the possible factors that are involved in the reduction of photosynthesis in pistachio are discussed., S. N. Vemmos, A. Papagiannopoulou, S. Coward., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

67. Ekologie chovu včel: konference ve stínu velkého včelaře G. J. Mendela

Creator:
Karel Sládek
Format:
bez média and svazek
Type:
article, text, články, journal articles, model:article, and TEXT
Subject:
Biologické vědy, Mendelova společnost pro včelařský výzkum, Ekologie chovu včel (2014), biologie, chov včel, trnovník akát, pesticidy, landscape, biology, bee keeping, pesticides, black locust, apidologie, ekologický chov, 2, and 57/59
Language:
Czech
Description:
Karel Sládek.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

69. Evoluce tolerance

Creator:
Natália Martínková
Format:
print, bez média, and svazek
Type:
article, text, články, journal articles, model:article, and TEXT
Subject:
Biologické vědy, biologie, plísně, netopýři, biology, molds (Fungi), bats, 2, and 57/59
Language:
Czech
Description:
Czech White-Nose Syndrome Team together with international collaborators discovered mechanisms of tolerance that protect Palearctic bats from white-nose syndrome (WNS), the disease that caused mass die-off in North America. The discovery raises hope for a better future of bats in North American ecosystems. White-nose syndrome (WNS) is caused by a generalist pathogen Pseudogymnoascus destructans with the worst possible characteristics of an infectious fungal agent. The generalist nature of the WNS fungus means that it can infect any bat hibernating in a contaminated cave or mine and, moreover, it may remain viable and virulent, waiting for its hosts until the next hibernation period. Harmless to humans, the WNS fungus kills hibernating North American bats in winter. However, loss of voracious insectivorous bats from agricultural ecosystems may result in economic costs required for increased pest control. Without mass die-offs of bats harbouring the WNS agent in Europe, the response to disease is an enigma. To study the survival crossroads, the Czech WNS Team focused on the relationship between pathogen quantity and disease under natural conditions. High disease prevalence together with high fungal loads in absence of bat population declines in Eurasia indicates disease tolerance mechanisms, where hosts limit harm inflicted by the pathogen but do not hinder its growth. The tolerance mechanisms revealed by the Czech WNS Team is a function of bat adaptation to the presence of the pathogen. and Natália Martínková.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public