Syntheses of 1-[2-(Phosphonomethoxy)Alkyl]Thymine Monophosphates and an Evaluation of their Inhibitory Activity Toward Human Thymidine Phosphorylase

A series of new monophosphates of 1-[2-(phosphonomethoxy)alkyl]thymines, such as PMPTp_, 3-MeO-PMPTp, HPMPTp, and FPMPTp, were synthesized and tested for their ability to inhibit human thymidine phosphorylase. Kinetic measurements of enzyme activity were performed using thymidine and inorganic phosphate as the substrates. The data show that some monophosphates provide a considerable increase of the multisubstrate inhibitory effect. The highest inhibitory potency was found with (R)-FPMPTp 4c (K _i ^dT = 4.09 ± 0.47 μM, K _i(P_i) = 2.13 ± 0.29 μM) and (R) 3-MeO-PMPTp 4d (K _i ^dT = 5.78 ± 0.71 μM, K _i(P_i) = 2.71 ± 0.37 μM).     

Simulation of Seed Digestion by Birds: How Does It Reflect the Real Passage Through a Pigeon’s Gut?

Simulation of seed passage through a bird’s gut is an important tool for comparing the effect of bird digestion and thus the potential for plant dispersal by endozoochory. However, sufficient methodology is missing. Thus, we subjected seeds of 20 plant species to seven different simulations of gut passage and to the real passage through a pigeon’s gut to determine which simulation type best reflects the effects of real bird digestion. We also measured various seed traits to identify the traits responsible for differences between species. Results show that four out of seven simulations were significant predictors of seed survival after gut passage. The fit between direct digestion by the pigeon and the different simulation treatments was, however, species-specific and depends not only on the commonly tested traits such as seed mass and water permeability, but also on other unmeasured traits. Seed mass was the best predictor of differences between real digestion and simulation. Selecting one type of simulation to be a good predictor of seed survival after gut passage is difficult. The strongest simulation (24-h scarification and 240-min acid immersion) is the best predictor and may be used to compare the ability of seeds to be dispersed by bird endozoochory. Such knowledge can be included in databases of species traits, as is currently done for many other species traits.     

Two newly recognized species of Hemidactylus (Squamata,Gekkonidae) from the Arabian Peninsula?and Sinai,Egypt

A recent molecular phylogeny of the Arid clade of the genus Hemidactylus revealed that the recently described H. saba and two unnamed Hemidactylus species from Sinai, Saudi Arabia and Yemen form a well-supported monophyletic group within the Arabian radiation of the genus. The name ‘Hemidactylus saba species group’ is suggested for this clade. According to the results of morphological comparisons and the molecular analyses using two mitochondrial (12S and cytb) and four nuclear (cmos, mc1r, rag1, rag2) genes, the name Hemidactylus granosus Heyden, 1827 is resurrected from the synonymy of H. turcicus for the Sinai and Saudi Arabian species. The third species of this group from Yemen is described formally as a new species H. ulii sp. n. The phylogenetic relationships of the members of ‘Hemidactylus saba species group’ are evaluated and the distribution and ecology of individual species are discussed.     

A?new species of the genus Duvalius sg. Neoduvalius from Montenegro with taxonomical remarks on the genus Duvalius (Coleoptera,Carabidae, Trechini)

Duvalius (sg. Neoduvalius) gejzadunayi sp. n. from Pećina u Dubokom potoku cave ( Donje Biševo village near Rožaje, Montenegro), the first known representative of this subgenus from the territory of Montenegro is described, illustrated and compared with the related species of the subgenus Neoduvalius Müller, 1913. This new species is characterised by depigmented, medium sized body, totally reduced eyes, deep and complete frontal furrows, 3–4 pairs of discal setae in third elytral stria, as well as by the shape of aedeagus. Data on the distribution and the ecology of this remarkable species, as well as a check-list of the subgenus Neoduvalius are also provided. Recently described genera Serboduvalius Ćurčić, S. B. Pavićević & Ćurčić, B.P.M., 2001, Rascioduvalius Ćurčić, S. B. Brajković, Mitić & Ćurčić, B.P.M., 2003, Javorella Ćurčić, S. B. Brajković, Ćurčić, B.P.M. & Mitić, 2003 and Curcicia Ćurčić, S. B. & Brajković, 2003 are regarded as junior synonyms of the genus Duvalius Delarouzée.     

Plant species richness–productivity relationships in a low-productive boreal region

Local species richness–productivity (SR–P) relationship is usually reported as unimodal if long productivity gradients are sampled. However, it tends to be monotonically increasing in low-productive environments due to the decreasing part of the SR–P curve being truncated. Previous work indicated that this can hold true for forest herb layers, because of an upper bound on productivity caused mainly by canopy shading. Here, we ask whether the same pattern exists in a region with an upper bound on productivity caused by a harsh climate. We sampled herbaceous vegetation of boreal forests and grasslands in a low-productive region of central Yakutia (NE Siberia) with dry and winter-cool continental climate. We collected data on species composition, herb-layer productivity (aboveground herbaceous biomass), soil chemistry and light availability. We applied regression models to discriminate between monotonically increasing, decreasing and unimodal responses of herb-layer species richness to measured variables and analysed trends in the species-pool size and beta diversity along the productivity gradient. Our expectation of the monotonically increasing SR–P relationship was confirmed for neither forest herb layers nor grasslands. In the forest herb layers, no relationship was detected. In grasslands, the relationship was unimodal with species richness decline starting at much lower productivity levels than in more productive temperate grasslands. Potential causes for this decline are either limitation of local species richness by the species pool, which contains few species adapted to more productive habitats, or competitive exclusion, which can become an important control of species richness under lower levels of productivity than is the case in temperate grasslands.     

Eye trematode infection in small passerines in Peru caused by Philophthalmus lucipetus,an agent with a zoonotic potential spread by an invasive freshwater snail

Until now, four species of eye trematodes have been found in South America. Of them, Philophthalmus lucipetus (synonymized with Philophthalmus gralli) displays a broad host spectrum, with at least 30 bird species (prevalently large water birds), five mammal species and humans serving as definitive hosts, and with snails Fagotia (Microcolpia) acicularis, Amphimelania holandri, Melanopsis praemorsa and Melanoides tuberculata serving as intermediate hosts. When examining a total of 50 birds of ten species in the wetland of Pantanos de Villa, Lima, Peru in July 2011, eye trematodes were identified visually in the edematous conjunctival sac of 11 (48%) out of 23 resident many-colored rush tyrants Tachuris rubrigastra. Based on morphometric characteristics, the trematodes were identified as P. lucipetus. ITS2 and CO1 gene of the examined specimens combined showed a 99% similarity to an Iranian isolate of Philophthalmus sp. from the intermediate host Melanoides tuberculata, an invasive freshwater snail, suggesting that these two isolates represent the same species with a wide geographical range. Moreover, the prevalence of infection with the philophthalmid cercariae was 31% in 744 Melanoides tuberculata examined in Pantanos de Villa in 2010. It is evident that P. lucipetus occurs throughout the world as well as locally, including Eurasia and South America. Here we report this trematode for the first time in Peru, and we were the first to sequence any of the South American eye trematodes. Low host specificity of P. lucipetus and the invasive character of Melanoides tuberculata as a competent intermediate host suggest that eye trematodosis caused by P. lucipetus may emerge frequently in various parts of the world, especially in the tropics. Increase of the zoonotic potential of the P. lucipetus associated with this invasive snail spreading across the world is predictable and should be of interest for further research.     

Effects of surrounding landscape on parasitism of alfalfa aphids in an IPM crop system in northern Catalonia

The parasitism (Hymenoptera, Braconidae, Aphidiinae) of alfalfa aphids (Hemiptera, Aphididae) was determined during three crop growing seasons. The highest rates of parasitism of Acyrthosiphon pisum Harris and of Therioaphis trifolii Monell occurred during the first-second and the fourth alfalfa intercuts, respectively. The landscape surrounding the fields affected only parasitism rates of A. pisum. During the second intercut the forest area had a negative influence on parasitism rates, whereas the bordering surfaces of alfalfa and winter cereals had a positive influence. Positive correlations were found between the rates of parasitism of A. pisum and the rate of aphid population increase in the first intercut. By contrast, negative correlations were found in the second intercut, when the aphid population peaked, suggesting that parasitoids contribute to the regulation of the aphid. This study stresses that regulation of alfalfa aphids cannot be explained solely on the basis of one functional group of natural enemies.     

Short-Term Medieval Settlement Activities Irreversibly Changed Forest Soils and Vegetation in Central Europe

In Europe, many contemporary forests are not continuous, but were established on former agricultural land in territories of deserted villages. We aimed to explore whether medieval settlement activities of only 60 years irreversibly changed soil properties and whether these changes were reflected by contemporary forest vegetation. The research was performed in the deserted village of K?í, which existed from 1357 to ca 1420 AD in a current oak forest on sandy soils in the Czech Republic. We identified four former land-use types (building sites, courtyards, the village square, and gardens), where we analyzed soil properties and plant species composition of the forest understory. Higher concentrations of plant-available P, K, Ca, and Mg as well as the total concentrations of organic C and trace elements (As, Cd, Cu, and Zn) were recorded at former building sites with neutral soils, compared to the other former land-use types with acidic soils. The four-times higher species richness at former building sites compared to the former gardens indicate the strong effect of soil pH and nutrient availability on plant species composition, even on the spatial scale of several square metres. Understanding recent patterns in soil properties and biodiversity in Central European forests requires detailed knowledge of former land use over centuries. Analysis of contemporary soil properties together with analysis of vegetation can help to identify former land-use types in deserted villages.