Environmental stress can lead to a reduction in developmental homeostasis, which could be reflected in increased variability of morphological traits. Fluctuating asymmetry (FA) is one possible manifestation of such a stress, and is often taken as a proxy for individual fitness. To test the usefulness of FA in morphological traits as an indicator of environmental quality, we studied the effect of urbanisation on FA in ground beetles (Carabidae) near a Danish city. First, we performed a critical examination whether morphological character traits suggested in the literature displayed true fluctuating asymmetry in three common predatory ground beetles, Carabus nemoralis, Nebria brevicollis and Pterostichus melanarius. Eight metrical (length of the second and third antennal segments, elytral length, length of the first tarsus segment, length of the first and second tibiae, length of the proximal and distal spines on the first femurs) and one meristic (the number of spines on the second tibiae) traits were examined. Most of them showed FA but not consistently. Females generally displayed a higher level of FA than males. Finally, we examined the changes in the level of FA in bilateral morphological traits along an urbanisation gradient (forest - suburban forest - forest fragments in urban park) to test whether environmental stress created by urbanisation is reflected in FA. Ground beetles common along a Danish urbanisation gradient did not seem to indicate differences in habitat quality by their level of FA.
The northern lagoon of Tunis is closed, except for a limited communication with the sea via a very narrow channel. It is subjected, as the majority of Mediterranean lagoons, to environmental/anthropogenic constraints related mainly to the slowness of circulation and renewal of its waters, and also to surrounding human activities. Fifteen stations distributed in the northern lagoon of Tunis were sampled seasonally. The main physicochemical parameters of the water and the sediment were measured and the macro-invertebrates were sampled and identified. Results show that the nitrogen and phosphorus nutrients are relatively low in the study site compared with other Tunisian and Mediterranean lagoons, and the dissolved oxygen content and the pH are relatively satisfactory. However, the temperature and salinity which are higher compared with other Tunisian lagoons show remarkable seasonal variations, and seem to play interesting role in shaping community structure. Thus, the macrofauna community is poorly diversified and impoverished during warm/dry seasons, but slightly improved with precipitation and flow of freshwater during cool/rainy seasons. According to our own results and those of the literature, it seems that the northern lagoon of Tunis has for several years been affected by some major factors, mainly high temperature and salinity, sediment silting and perhaps an excess of organic matter. This has led to deep changes in the macrofauna community before being in its current status.
A preliminary checklist of Tamaricaceae in the Indian subcontinent has been prepared on the basis of primary observations of different taxa belonging to this family in wild habitats and on secondary observations based on examining herbarium specimens and taxonomic literature. On the Indian subcontinent (comprising Bangladesh, Bhutan, Myanmar, Nepal, Pakistan, Sri Lanka and India), the family Tamaricaceae is poorly represented (20% of all species). The present paper deals with a brief review of distribution, endemism, possible fossil ancestry, economic potential and survival threat on existing taxa, etc. The present status of endemism of Tamaricaceae in Indian subcontinent (22.5% in 2002–2007) has been compared to the data of previous investigations (50% in 1939–1940) done in nineteenth century. The decreasing rate of endemism either indicates decreasing number of endemic taxa or increasing span of distribution of pan-endemic taxa belonging to this family. For better understanding of the functional aspects of species dynamics the rate of endemism in percent of a particular group of plants has been used as key index here.
Authors:Eszter Laczkó-Zöld, Péter Forgó, István Zupkó, Eşianu Sigrid, and Judit Hohmann
Physalin D was isolated from the methanol extract of Physalis alkekengi L. fruits by combination of different chromatographic methods (CPC, TLC, HPLC). The structure was elucidated based on 1H and 13C NMR spectral analysis with the aid of 2D-correlation spectroscopy (1H, 1H-COSY, HSQC and HMBC) and comparison with literature data. The quantity of physalin D in mature and immature fruits and calyces was determined by RP-HPLC-UV method. Among the studied samples, immature calyx showed the highest content of physalin D (0.7880 ± 0.0612%), while mature calyx contained 4 times less amount (0.2028 ± 0.016%). The physalin D content of the fruit was much lower; immature fruits contained 0.0992 ± 0.0083% physalin D and mature fruits 0.0259 ± 0.0021%. The antiproliferative activity of the CHCl3 extract and its fractions was tested on three cancer cell lines (HeLa, MCF-7 and A431). The antiproliferative activity of physalin D is discussed with regard the published data.
Authors:R. Okada, H. Ikeno, T. Kimura, Mizue Ohashi, H. Aonuma, and E. Ito
A honeybee informs her nestmates of the location of a flower by doing a waggle dance. The waggle dance encodes both the direction of and distance to the flower from the hive. To reveal how the waggle dance benefits the colony, we created a Markov model of bee foraging behavior and performed simulation experiments by incorporating the biological parameters that we obtained from our own observations of real bees as well as from the literature. When two feeders were each placed 400 m away from the hive in different directions, a virtual colony in which honeybees danced and correctly transferred information (a normal, real bee colony) made significantly greater numbers of successful visits to the feeders compared to a colony with inaccurate information transfer. Howerer, when five feeders were each located 400 m from the hive, the inaccurate information transfer colony performed better than the normal colony. These results suggest that dancing’s ability to communicate accurate information depends on the number of feeders. Furthermore, because non-dancing colonies always made significantly fewer visits than those two colonies, we concluded that dancing behavior is beneficial for hives’ ability to visit food sources.
Authors:G. Kemény, K. Penksza, Nagy Z., and et al.
A neighbourding -quadrate transect study was conducted in order to examine the possibile relationship between small scale topography and coenotaxa occurrence and cover in subassociations of Festucetum vaginataeRapaics ex Soó 1929 sandy grassland plant community near Fülöpháza. These investigations served as a starting point in later soil seed bank studies. Cover of species was recorded in three transects of different exposition starting on the top of different dunes and ending in the depressions. Subassociations and facies forming species of the community occurred in all investigated transects. Parts of the transects could not have been classified unambiguously into any of the coenotaxa mentioned in the literature. In these zones the charactersitic species of the different subbasociations and facies were occurding together. These patches are propbably also the ones where changes in dominance relations and simultaneous spread of a species can relatively easily happen, as it is the case with Cleistogenes serotina. Annual vegetation of the open sandy grassland, ond the other hand, has occured only in the transition zones, between the subassociations or facies. In these transects moss-lichen synusia were peresent usually in the subassociation Festucetum vaginatae pennatae Kerner 1863.
This paper describes aspects of the leaf anatomy of two Salvia taxa, Salvia nemorosa L. subsp. tesquicola (Klokov et Pobed.) Soó and Salvia nutans L., as well as their hybrid, Salvia ×dobrogensis Negrean, aiming to highlight common anatomical characteristics and superiority of the hybrid, compared with its parental taxa, less subject to these plants raised in the literature. Differences were found both in the structure of petiole and blade. For the petiole, differences arise concerning the degree of development of the external (collenchyma and chlorenchyma) and inner cortex. The vascular system in all considered taxa, comprises a great number of vascular bundles, with different levels of development of the conductive tissues. The mesophyll is heterogeneous, bifacial in S. nemorosa subsp. tesquicola and the hybrid, and equifacial in S. nutans. The presence and anatomy of numerous glandular and non-glandular trichomes (hairs), different in structure, shape and size, were investigated and evaluated. Stomata are present on both upper and lower epidermis of the blade having diacytic type, impressing, as well, an amphistomatic character. The vascular system of the midrib of the studied Salvia taxa is well developed, in particular those of the hybrid species. The analysis of petiole and blade anatomy of two Salvia taxa and their hybrid reveals common and specific features from which we could conclude that although the hybrid leaf is more developed anatomically than its parental taxa, the petiole has many features similar to that of Salvia nutans and the blade is almost similar to that of Salvia nemorosa species.
Authors:G. Amori, S. Gippoliti, L. Luiselli, and C. Battisti
Changes in taxa composition among different communities in a landscape or along an environmental gradient are defined as β-diversity. From a biogeographic point of view, it is interesting to analyse patterns of β-turnover across latitudinal bands, and to understand whether P-diversity is significantly associated with endemism at lower latitudes, as predicted by theory. We inspected these issues by using squirrels (Rodentia, Sciuridae) as a study case. Distribution data for each genus were obtained from literature and mapped. The two hemispheres were subdivided into 23 latitudinal bands of equal area, and we calculated a β-turnover index between latitudinal bands with two formulae: Wilson and Shmida’s (1984) and Lennonetal.’s (2001) indices. We found that the peak of number of Sciuridae genera significantly corresponded to the peak in β-turnover scores at the same latitudes (25–31°N) with Wilson and Shmida’s (1984), but not with Lennon et al.’s (2001) index. We also found that the turnover between ground and tree squirrels corresponded to the grassland vegetation latitudinal bands (around 40° N), and the beginning of the latitudinal bands characterized by tropical and subtropical forests is accomplished with the occurrence of tree and flying squirrels
The study of invasion ecology usually focuses on the negative impacts of alien species, while potential positive impacts are often overlooked. Understanding of biotic interactions may thus be skewed towards the negative, which could have important implications for ecological management and conservation. This article provides a comprehensive review of all types of impacts, both beneficial and detrimental, that can result from species translocation. An extensive review of literature on species introductions to terrestrial, freshwater and marine ecosystems and involving a wide range of taxa (including microorganisms, parasites, plants, insects, amphibians, reptiles, birds, mammals, fish and Crustacea) showed that, despite limited research into facilitative alien-native interactions, such interactions occur surprisingly frequently. Examples were found of introduced species acting as hosts, food sources, pollinators or seed dispersers for native species, as well as providing herbivory, predatory or parasite release. However, research showed that numerous negative interactions also occurred and combination impacts (when an alien benefits some natives but disadvantages others) were common. In many cases, the traditional view that biological invasions constitute a significant threat to native biota is both accurate and appropriate. Efforts to prevent translocation and control non-native species can be vital. However, the “native good, alien bad” maxim does not convey the complexity of invasion ecology: alien species do not axiomatically pose a threat to native biota. In order to move understanding of invasion ecology forward and to develop maximally-effective management strategies, facilitative alien-native interactions need to be added into the alien species debate.
Authors:A. Wiater, J. Szczodrak, and M. Pleszczyńska
Conidia of TrichodermaharzianumF-340, an active producer of fungal mutanase, were mutagenized with physical and chemical mutagens used separately or in combination. After mutagenesis, the drop in conidia viability ranged from 0.004% to 71%. Among the applied mutagens, nitrosoguanidine gave the highest frequency of cultures with enhanced mutanase activity (98%). In total, 400 clones were isolated, and preliminarily evaluated for mutanase activity in flask microcultures. Eight most productive mutants were then quantified for mutanase production in shake flask cultures. The obtained results fully confirmed a great propensity of all the tested mutants to synthesize mutanase, the activity of which increased from 59 to 107% in relation to the parental T.harzianumculture. The best mutanase-overproducing mutant (T. harzianumF-340-48), obtained with nitrosoguanidine, produced the enzyme activity of 1.36 U/ml (4.5 U/mg protein) after 4 days of incubation in shake flask culture. This productivity was almost twices higher than that achieved by the initial strain F-340, and, at present, is the best reported in the literature. The potential application of mutanase in dentistry is also discussed.