Velemyši, dříve nazývané krysy obláčkové, jsou největší myšovití hlodavci žijící endemicky na Filipínách. Velemyš dinagatskou (Crateromys australis), považovanou za potenciálně vyhynulou, se nám podařilo znovuobjevit 37 let od jejího posledního (a zároveň prvního) nálezu a vědeckého popisu. To bylo také impulzem k návrhu nového českého jména velemyši pro celou skupinu obláčkových krys. Velemyš dinagatská byla nalezena na severu ostrova Dinagat. Nyní je řazena mezi kriticky ohrožené druhy. Ohrožené jsou také ostatní druhy této skupiny, a to zejména kvůli masivní těžbě dřeva a nerostných surovin a tím ničením jejich přirozeného prostředí. Proto je cílená ochrana je nezbytná k přežití tohoto i ostatních druhů velemyší., Cloud rats are the largest murid rodents endemic to the Philippines. The Dinagat Cloud Rat (Crateromys australis), considered to be potentially extinct, was rediscovered in the north of Dinagat Island after 37 years from its first discovery and scientific description. We have also proposed a new Czech name. The species is now listed as critically endangered. All cloud rats are threatened by the destruction of their natural habitats by logging and mining. Targeted protection is therefore essential for their survival., and Milada Řeháková, Václav Řehák.
The great capricorn beetle or Cerambyx longicorn (Cerambyx cerdo, Linnaeus, 1758) is an internationally protected umbrella species representing the highly diverse and endangered fauna associated with senescent oaks. For the conservation and monitoring of populations of C. cerdo it is important to have a good knowledge of its microhabitat requirements. We investigated determinants and patterns of C. cerdo distribution within individual old, open-grown oaks. Trees inhabited by this species were climbed, and the number of exit holes and environmental variables recorded at two sites in the Czech Republic. Distribution of exit holes in relation to height above the ground, trunk shading by branches, orientation in terms of the four cardinal directions, diameter, surface and volume of inhabited tree parts were investigated. This study revealed that the number of exit holes in the trunks of large open-grown oaks was positively associated with the diameter of the trunk and openness and negatively with height above the ground, and the effects of diameter and openness changed with height. The number of exit holes in the surface of a trunk was also associated with the cardinal orientation of the surface. Approximately half of both C. cerdo populations studied developed less than 4 m and approximately a third less than 2 m above the ground. This indicates that most C. cerdo develop near the ground. Active management that prevents canopy closure is thus crucial for the survival of C. cerdo and searching for exit holes is an effective method of detecting sites inhabited by this species., Jan Albert, Michal Platek, Lukas Cizek., and Obsahuje seznam literatury
Rychlý růst počtu nepůvodních druhů je jednou z nejzávažnějších hrozeb pro světovou biodiverzitu i pro zemědělství. V článku jsou představeny dva druhy kněžic, jejichž rozšíření do České republiky v nejbližších letech očekáváme: invazní kněžice mramorovaná (Halyomorpha halys) pochází z východní Asie, kosmopolitní kněžice zeleninová (Nezara viridula) se šíří ze Středomoří patrně přirozeně v závislosti na globálním oteplování. Jelikož oba druhy jsou významnými zemědělskými škůdci, jsou uvedeny základní znaky sloužící k jejich rozlišení a rovněž údaje o jejich biologii a škodlivosti., A rapid increase in the number of alien species is one of the most important threats to global biodiversity as well as to agriculture. The article presents two species of the family Pentatomidae which are expected to reach the Czech Republic in the near future - the invasive Brown Marmorated Stink Bug (Halyomorpha halys) native to East Asia, and the cosmopolitan Southern Green Stink Bug (Nezara viridula), probably spreading naturally northwards from the Mediterranean due to global warming. Because both species are serious pests in agriculture, the key characteristics facilitating their identification are provided and illustrated along with information on their bionomics and pest status., and Petr Kment.
V této práci sumarizujeme data o výskytu invazních druhů řas a sinic v České republice a mapujeme reálná či potenciální rizika jejich rozšíření. Seznam invazních druhů v ČR obsahuje 10 druhů sinic, 9 rozsivek, 1 obrněnku, 1 zástupce třídy Ulvophyceae, 2 zelené řasy třídy Chlorophyceae a jednu krásivku., This paper summarizes data on alien species of algae and cyanobacteria in the Czech Republic; we identified actual or potential risks resulting from their spread. The list of aliens contains 10 species of Cyanobacteria (Cyanophyta), 10 species of Bacillariophyceae, one species of Dinophyta, one species of Ulvophyceae, two species of Chlorophyceae, and one species of Desmidiales., and Jan Kaštovský ... [et al.].
Caterpillars of the poplar lutestring moth, Tethea or, construct leaf shelters that they defend against intruding conspecifics using a combination of vibratory signals and physical aggression. Staged interactions between a resident caterpillar and introduced conspecific were recorded with a video camera and laser vibrometer. Residents crawl towards the intruder and perform three behaviours: lateral hitting, pushing, and mandible scraping. Vibrations caused by mandible scraping result from the caterpillar repeatedly scraping opened mandibles laterally against the leaf surface in bouts lasting 1.16 ± 0.39 s, with an average of 4 ± 1 scrapes per bout. We propose that these scrapes function in leaf shelter defense against conspecifics for the following reasons: Mandible scrapes are produced only by residents; they are generated when a resident is approached by an intruder; the rate of scraping increases as the intruder approaches the shelter; and residents in all trials retain their shelters, with the intruder leaving the leaf within 127.9 ±104.3s from the beginning of the trial. The function and evolutionary origins of vibration-mediated territoriality in caterpillars are discussed. and Jaclyn L. Scott, Jayne E. Yack.
Tomato samples were collected from the field of Absheron peninsula in Azerbaijan in order to evaluate the incidence of main Tobamoviruses. According to results of serological and molecular tests, Tomato mosaic virus (ToMV), Tobacco mosaic virus (TMV), and Pepper mild mottle virus (PMMoV) were detected as single and mixed infections (TMV + PMMoV; ToMV + PMMoV) in various tomato samples. It was found that Tobamovirus infection caused an increase in the content of malondialdehyde, alterations in the activities of peroxidase enzymes and quantitative and qualitative changes in their molecular isoforms. A comparison of thylakoid membrane polypeptides from virus-infected leaves indicated a decrease in the content of the thylakoid membrane polypeptides with molecular masses of 123, 55, 47, 33, 28-24, 17, and 15 kD. PSII efficiency and the content of chlorophylls (a and b) were significantly lower in the virus-infected leaves., I. M. Huseynova, S. M. Mirzayeva, N. F. Sultanova, D. R. Aliyeva, N. Sh. Mustafayev, J. A. Aliyev., and Obsahuje bibliografii
Dependence of ATP hydrolysis kinetics by the chloroplast coupling factor (CF1) on medium viscosity was studied at varying temperatures. For samples with oxidized and reduced CF1 γ-subunit, this dependence was shown to be described by Cramers’ relationship k - (η/ηo)-n, where k is the reaction rate constant, η/ηo is the medium/water viscosity ratio, and 0 < n < 1. Transition of the γ-subunit from its reduced to oxidized state was accompanied by increasing n value, which is indicative of increasing friction losses between certain enzyme sections and the solution. The increased medium viscosity produced no effect on the reaction activation energy which appeared to be almost the same for the both enzyme states. The molecular mechanisms responsible for CF1 activity loss in viscous media are discussed., A.N. Malyan., and Obsahuje bibliografii
Druhé pokračování o významu vitaminu D pro zdraví člověka (první bylo publikováno v Živě 4/2015) se zabývá jeho úlohou, kterou hraje v imunitě. Donedávna se nepředpokládalo, že by vitamin D mohl podmiňovat také imunitní procesy. Během posledních let se však nashromáždil dostatečný počet experimentálních i klinických studií, které dokládají, že při jeho nedostatečném příjmu dochází k poklesu zejména antiinfekční imunity, a souběžně s tím stoupá také riziko vzniku nesdělných onemocnění. Účelem tohoto sdělení není vyčerpávající informace o mechanismech jeho působen na imunitní systém, ale upozornění pro specialisty i laiky na tuto důležitou, ale prozatím opomíjenou problematiku., This is a further continuation of an 8/2015 article about the importance of vitamin D to the health of human beings (the first was published in Živa 4/2015). The article deals with the role that the vitamin plays in immunity. Until recently, it was not assumed that vitamin D could also be conditional upon immune processes and that it determines the correct function of both natural and adaptive immunity. In recent years, however, a sufficient number of experimental and clinical studies have accumulated, providing evidence that insufficient intake of vitamin D could not only induce decreased immunity to infection but also contribute substantially to an increased risk of non-communicable diseases. The purpose of this communication is not exhaustive information on the mechanisms of vitamin D effects on the immune system, but as an alert to specialists and laymen on hitherto neglected issues., and Petr Šíma, Bohumil Turek.