Bats - viral Pandora's box

Netopýři, jako velmi stará vývojová větev savců, jsou významnými rezervoáry virových patogenů a v mnoha případech jsou i vědecky doloženými přenašeči daných virů. Tyto viry se stále více dostávají do povědomí, hlavně díky zvětšující se lidské populaci, a tedy častějšímu kontaktu lidí a netopýrů. V této práci se budu zabývat jen některými zoonózami, které rod Chiroptera přenáší, vybral jsem je podle míry jejich vědeckého poznání a samozřejmě podle dopadu na lidskou společnost. Tato oblast je ale stále plná informací nejasných nebo zcela neobjevených, další výzkum je tudíž žádoucí. Základními metodami identifikace virů, které se používají pro výzkum nových virů, se zabývám v druhé části práce. Klíčová slova: netopýři, virus, zoonózy, rezervoár, epidemieBats, as a very old order of mammals, are significant reservoirs of viral pathogens and in many cases are also scientifically proven carriers of the viruses. These viruses are becoming more and more known, mainly due to the growing human population and thus the frequent contact of humans and bats. In this work I will follow up only some zoonoses that the Chiroptera family carries and I selected them according to their scientific knowledge and, of course, the impact on human society. However, this area is still full of information unclear or completely unknown, so further research is desirable. The basic methods of virus identification that are used to investigate new viruses are discussed in the second part. Key words: bats, virus, zoonosis, reservoir, epidemicsKatedra genetiky a mikrobiologieDepartment of Genetics and MicrobiologyPřírodovědecká fakultaFaculty of Scienc

Bats - viral Pandora's box

Bats, as a very old order of mammals, are significant reservoirs of viral pathogens and in many cases are also scientifically proven carriers of the viruses. These viruses are becoming more and more known, mainly due to the growing human population and thus the frequent contact of humans and bats. In this work I will follow up only some zoonoses that the Chiroptera family carries and I selected them according to their scientific knowledge and, of course, the impact on human society. However, this area is still full of information unclear or completely unknown, so further research is desirable. The basic methods of virus identification that are used to investigate new viruses are discussed in the second part. Key words: bats, virus, zoonosis, reservoir, epidemic

Comparative analyses of basal rate of metabolism in mammals: data selection does matter.

Basal rate of metabolism (BMR) is a physiological parameter that should be measured under strictly defined experimental conditions. In comparative analyses among mammals BMR is widely used as an index of the intensity of the metabolic machinery or as a proxy for energy expenditure. Many databases with BMR values for mammals are available, but the criteria used to select metabolic data as BMR estimates have often varied and the potential effect of this variability has rarely been questioned. We provide a new, expanded BMR database reflecting compliance with standard criteria (resting, postabsorptive state; thermal neutrality; adult, non-reproductive status for females) and examine potential effects of differential selectivity on the results of comparative analyses. The database includes 1739 different entries for 817 species of mammals, compiled from the original sources. It provides information permitting assessment of the validity of each estimate and presents the value closest to a proper BMR for each entry. Using different selection criteria, several alternative data sets were extracted and used in comparative analyses of (i) the scaling of BMR to body mass and (ii) the relationship between brain mass and BMR. It was expected that results would be especially dependent on selection criteria with small sample sizes and with relatively weak relationships. Phylogenetically informed regression (phylogenetic generalized least squares, PGLS) was applied to the alternative data sets for several different clades (Mammalia, Eutheria, Metatheria, or individual orders). For Mammalia, a 'subsampling procedure' was also applied, in which random subsamples of different sample sizes were taken from each original data set and successively analysed. In each case, two data sets with identical sample size and species, but comprising BMR data with different degrees of reliability, were compared. Selection criteria had minor effects on scaling equations computed for large clades (Mammalia, Eutheria, Metatheria), although less-reliable estimates of BMR were generally about 12-20% larger than more-reliable ones. Larger effects were found with more-limited clades, such as sciuromorph rodents. For the relationship between BMR and brain mass the results of comparative analyses were found to depend strongly on the data set used, especially with more-limited, order-level clades. In fact, with small sample sizes (e.g. <100) results often appeared erratic. Subsampling revealed that sample size has a non-linear effect on the probability of a zero slope for a given relationship. Depending on the species included, results could differ dramatically, especially with small sample sizes. Overall, our findings indicate a need for due diligence when selecting BMR estimates and caution regarding results (even if seemingly significant) with small sample sizes