East African bryophytes xxx. new liverwort and hornwort records

Records of 45 liverwort and one hornwort species new to or very rare in East African countries. Among them the occurrence of Leptolejeunea subrotundifolia is new to Africa, Anthoceros punctatus, Cephaloziella antheli-oides, Diplasiolejeunea cobrensis, Marsupella sparsifolia,Tritomaria camerunen-sis and Plagiochila rodriguezii are new to tropical East Africa while Cephalozi-ella tenuissima, C. transvaalensis, Chiloscyphus muhavurensis, Cololejeunea inflectens, C. magillii, C. peponiformis, Diplasiolejeunea hamata, D. rudolphia-na, Harpalejeunea filicuspis, Lopholejeunea sphaerophora and Syzygiella col-orata, to the bryoflora of Madagascar. Finally Cephalozia connivens var. fissa, Solenostoma onraedtii, Plagiochila incerta, P. repanda, P. stricta, Colura dusenii and Diplasiolejeunea kraussiana are new to the flora of Comoro Islands. The new combination of Drepanolejeunea pentadactyla var. dactylophoroides is also presented

Proton Affinities of Organocatalysts Derived from Pyridine N-oxide

Proton affinities of several efficient organocatalysts METHOX, QUINOX, ANETOX, KOTOX, FUREOX, and FUROOX bearing a pyridine N-oxide or 2,2′-bipyridyl N,N′-dioxide moiety were de-termined by using extended kinetic method and density functional theory calculations. Proton affinities are in the range of 1030–1060 kJ mol–1. Using isodesmic reactions, the effect of combining two pyridine N-oxide units in the neutral and the protonated molecule was studied: The combination of an unfavorable interaction in the former case and a favorable interaction in the latter accounts for the superbasic proper¬ties of 2,2′-bipyridyl N,N′-dioxides. Last but not least, the theoretically predicted pKa in ethanol are 0.1, –2.7, 0.9, 1.8, 1.9, and 2.3 for the METHOX, QUINOX, ANETOX, FUROOX, FUREOX, and KOTOX, respectively

Direct Cyclopalladation of Fluorinated Benzyl Amines by Pd3(OAc)6 : The Coexistence of Multinuclear PdnReaction Pathways Highlights the Importance of Pd Speciation in C-H Bond Activation

Palladacycles are key intermediates in catalytic C-H bond functionalization reactions and important precatalysts for cross-couplings. It is commonly believed that palladacycle formation occurs through the reaction of a substrate bearing a C-H bond ortho to a suitable metal-directing group for interaction with, typically, mononuclear "Pd(OAc)2"species, with cyclopalladation liberating acetic acid as the side product. In this study, we show that N,N-dimethyl-fluoro-benzyl amines, which can be cyclopalladated either ortho or para to fluorine affording two regioisomeric products, can occur by a direct reaction of Pd3(OAc)6, proceeding via higher-order cyclopalladated intermediates. Regioselectivity is altered subtly depending on the ratio of substrate:Pd3(OAc)6 and the solvent used. Our findings are important when considering mechanisms of Pd-mediated reactions involving the intermediacy of palladacycles, of particular relevance in catalytic C-H bond functionalization chemistry

Multi-seasonal systematic camera-trapping reveals fluctuating densities and high turnover rates of Carpathian lynx on the western edge of its native range

Camera-trapping and capture-recapture models are the most widely used tools for estimating densities of wild felids that have unique coat patterns, such as Eurasian lynx. However, studies dealing with this species are predominantly on a short-term basis and our knowledge of temporal trends and population persistence is still scarce. By using systematic camera-trapping and spatial capture-recapture models, we estimated lynx densities and evaluated density fluctuations, apparent survival, transition rate and individual's turnover during five consecutive seasons at three different sites situated in the Czech-Slovak-Polish borderland at the periphery of the Western Carpathians. Our density estimates vary between 0.26 and 1.85 lynx/100 km2 suitable habitat and represent the lowest and the highest lynx densities reported from the Carpathians. We recorded 1.5-4.1-fold changes in asynchronous fluctuated densities among all study sites and seasons. Furthermore, we detected high individual's turnover (on average 46.3 +- 8.06% in all independent lynx and 37.6 +- 4.22% in adults) as well as low persistence of adults (only 3 out of 29 individuals detected in all seasons). The overall apparent survival rate was 0.63 +- 0.055 and overall transition rate between sites was 0.03 +- 0.019. Transition rate of males was significantly higher than in females, suggesting male-biased dispersal and female philopatry. Fluctuating densities and high turnover rates, in combination with documented lynx mortality, indicate that the population in our region faces several human-induced mortalities, such as poaching or lynx-vehicle collisions. These factors might restrict population growth and limit the dispersion of lynx to other subsequent areas, thus undermining the favourable conservation status of the Carpathian population. Moreover, our study demonstrates that long-term camera-trapping surveys are needed for evaluation of population trends and for reliable estimates of demographic parameters of wild territorial felids, and can be further used for establishing successful management and conservation measures.Postprin

Exploring the impact of fossil constraints on the divergence time estimates of derived liverworts

In this study, we evaluate the impact of fossil assignments and different models of calibration on divergence time estimates carried out as Bayesian analyses. Estimated ages from preceding studies and liverwort inclusions from Baltic amber are used as constraints on a molecular phylogeny of Cephaloziineae (Jungermanniopsida) obtained from sequences of two chloroplast coding regions: rbcL and psbA. In total, the comparison of 12 different analyses demonstrates that an increased reliability of the chronograms is linked to the number of fossils assigned and to the accuracy of their assignments. Inclusion of fossil constraints leads to older ages of most crown groups, but has no influence on lineage through time plots suggesting a nearly constant accumulation of diversity since the origin of Cephaloziineae in the early to Middle Jurassic. Our results provide a note of caution regarding the interpretation of chronograms derived from DNA sequence variation of extant species based on a single calibration point and/or low accuracy of the assignment of fossils to nodes in the phylogeny