Richness, Abundance, and Complementarity of Fruit-feeding Butterfly Species in Relict Sacred Forests and Forest Reserves of Ghana

Sacred forest groves in Ghana are centuries old protected areas that were once part of continuous forest cover but now mostly exist as relict forest patches embedded in an agropastoral landscape. We conducted a year-long survey of the fruit-feeding butterfly fauna of four sacred groves and two forest reserves in the moist semi-deciduous forest zone of Ghana to characterize resident species diversity and complementarity among communities. Joint analysis of frugivorous butterfly diversity at these six forest fragments, which ranged in size from 6 to 5000 ha, was used to evaluate the conservation potential of these ancient indigenous reserves. A total of 6836 individuals were trapped across all sites, representing 79 species and five subfamilies. Community diversity was characterized in terms of, (a) number of species accumulated versus sampling effort, (b) rarefied species richness, (c) nonparametric richness estimates, (d) species evenness, (e) Simpson’s Index of Diversity, and (f) complementarity of communities. Diversity of the fruit-feeding butterfly communities, quantified in terms of both species evenness and rarefied species richness, was higher at the larger forest reserves than at the small sacred forest groves. Additionally, although all sites had species trapped only at that site, the 5000-ha forest reserve harbored a resident community that was clearly distinctive from and more diverse than the other communities including the other forest reserve. Hence, our findings add to the burgeoning body of data that indicates large reserves are the foundation of successful conservation programs. Nonetheless, we found these small forest patches contribute to biodiversity conservation in at least three ways and these are identified and discussed. We also identify a number of species that appear more or less vulnerable to dynamics of forest fragmentation based on changes in their relative abundance across sites and we interpret these data in the context of potential indicator species and theoretical predictions of at-risk species.     

PHYSIOLOGICAL AND OPTICAL PROPERTIES OF RHIZOSOLENIA FORMOSA (BACILLARIOPHYCEAE) IN THE CONTEXT OF OPEN-OCEAN VERTICAL MIGRATION1

Cultures of Rhizosolenia formosa H. Peragallo were studied to assess whether or not physiological and optical characteristics of this large diatom were consistent with the ability to migrate vertically in the open ocean. Time-course experiments examined changes in chemical composition and buoyancy of R. formosa during nitrate (N)–replete growth, N starvation, and recovery. Cells could maintain unbalanced growth for at least 53 h after depletion of ambient nitrate. Increases in C:N and carbohydrate: protein ratios observed during N starvation reversed within 24 h of reintroduction of nitrate to culture medium. Buoyancy was related to nutrition: Upon N depletion, the percentage of positively buoyant cells decreased to 4% from 11% but reverted to 9% within 12 h of nitrate readdition. Cells took up nitrate in the dark. Nitrogen-specific uptake rates averaged 0.48 d^?1; these rates were higher than N-specific growth rates (0. 15 d^?1), indicating the potential for luxury consumption of nitrate, which can be stored for later use. Measurements of photosynthesis vs. irradiance, chlorophyll-specific absorption (a_ph*(λ)), and pigment composition showed that cells may be adapted for growth under a wide range of irradiances. Values of a_ph*(λ) were lower for N-depleted cells than for N-replete cells, and N-depleted cells had higher ratios of total carotenoids to chlorophyll a. Aggregation of chloroplasts was more pronounced in N-depleted cells. These are possibly photoprotective mechanisms that would be an advantage to N-depleted cells in surface waters. Compounds that absorb in the ultraviolet region were detected in N-replete cells but were absent in N-depleted cultures. Overall, these results have important implications for migrations of Rhizosolenia in nature. Cells may survive fairly long periods in N-depleted surface waters and will continue to take up carbon; then they can resume nitrate uptake and revert to positive buoyancy upon returning to deep, N-rich water. Uncoupled uptake of carbon and nitrogen during migrations of Rhizosolenia is a form of new production that may result in the net removal of carbon from oceanic surface waters.     

Birds are tracking climate warming, but not fast enough

Range shifts of many species are now documented as a response to global warming. But whether these observed changes are occurring fast enough remains uncertain and hardly quantifiable. Here, we developed a simple framework to measure change in community composition in response to climate warming. This framework is based on a community temperature index (CTI) that directly reflects, for a given species assemblage, the balance between low- and high-temperature dwelling species. Using data from the French breeding bird survey, we first found a strong increase in CTI over the last two decades revealing that birds are rapidly tracking climate warming. This increase corresponds to a 91 km northward shift in bird community composition, which is much higher than previous estimates based on changes in species range edges. During the same period, temperature increase corresponds to a 273 km northward shift in temperature. Change in community composition was thus insufficient to keep up with temperature increase: birds are lagging approximately 182 km behind climate warming. Our method is applicable to any taxa with large-scale survey data, using either abundance or occurrence data. This approach can be further used to test whether different delays are found across groups or in different land-use contexts.     

Upward shift of alpine plants increases floristic similarity of mountain summits

Question: Does the upward shift of species and accompanied increase in species richness, induced by climate change, lead to homogenization of Alpine summit vegetation? Location: Bernina region of the Swiss Alps. Methods: Based on a data set from previous literature we expand the analysis from species richness to beta‐diversity and spatial heterogeneity. Species compositions of mountain summits are compared using a two‐component heterogeneity concept including the mean and the variance of Sørensen similarities calculated between the summits. Non‐metric multidimensional scaling is applied to explore developments of single summits in detail. Results: Both heterogeneity components (mean dissimilarity and variance) decrease over time, indicating a trend towards more homogeneous vegetation among Alpine summits. However, the development on single summits is not strictly unidirectional. Conclusions: The upward shift of plant species leads to homogenization of alpine summit regions. Thus, increasing alpha‐diversity is accompanied by decreasing beta‐diversity. Beta‐diversity demands higher recognition by scientists as well as nature conservationists as it detects changes which cannot be described using species richness alone.     

G-protein-coupled receptor prediction using pseudo-amino-acid composition and multiscale energy representation of different physiochemical properties

G-protein-coupled receptors (GPCRs) are the largest family of cell surface receptors that, via trimetric guanine nucleotide-binding proteins (G-proteins), initiate some signaling pathways in the eukaryotic cell. Many diseases involve malfunction of GPCRs making their role evident in drug discovery. Thus, the automatic prediction of GPCRs can be very helpful in the pharmaceutical industry. However, prediction of GPCRs, their families, and their subfamilies is a challenging task. In this article, GPCRs are classified into families, subfamilies, and sub-subfamilies using pseudo-amino-acid composition and multiscale energy representation of different physiochemical properties of amino acids. The aim of the current research is to assess different feature extraction strategies and to develop a hybrid feature extraction strategy that can exploit the discrimination capability in both the spatial and transform domains for GPCR classification. Support vector machine, nearest neighbor, and probabilistic neural network are used for classification purposes. The overall performance of each classifier is computed individually for each feature extraction strategy. It is observed that using the jackknife test the proposed GPCR–hybrid method provides the best results reported so far. The GPCR–hybrid web predictor to help researchers working on GPCRs in the field of biochemistry and bioinformatics is available at http://111.68.99.218/GPCR.     

Evaluation of Phytochemical Compositions and Biological Properties of Achillea gypsicola at Different Phenological Stages

Phytochemicals, which are commonly found at different levels in many medicinal plants, are natural strong antioxidants used in traditional medicine. In this research, determination of differences of phytochemical compositions and biological properties were aimed as periodically (pre‐, full and post flowering) and daily (6 am, 1 pm and 8 pm) in Achillea gypsicola Hub.‐Mor . The volatile oils belonging to A. gypsicola were obtained by hydrodistillation and analyzed by gas chromatography‐flame ionization detection (GC‐FID) and gas chromatography‐mass spectrometry (GC/MS). The antimicrobial activities of the volatile oils were determined with disc diffusion method. The microdilution method was used to determine minimum inhibitory concentration (MIC). Total phenolic and flavonoid contents were determined by spectrophotometric methods and antioxidant capacities were evaluated by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical, reducing power (RP) and metal chelating activity (MCA) assay. In addition, the phenolic acid and flavonoid compositions were evaluated by reversed phase‐high‐performance liquid chromatography (RP‐HPLC). This study presented a comprehensive report for the first time on evaluation of the phytochemical composition and the biological properties of A. gypsicola at different phenological stages. Thirty‐two compounds, containing the major component as camphor, 1,8‐cineole and borneol, were detected. Designated harvest time for the highest yield of volatile oils was found to be at full flowering stage‐1 pm. It has been observed that the volatile oil composition changes periodically and even daily. Also, in this research, menthol and menthone were found as the composition of volatile oil in Achillea species for the first time. Full flowering stage was found as the richest period in terms of phenolic acid and flavonoid compositions of A. gypsicola for the first time. The species examined in this research showed a high antioxidant and antimicrobial activity in comparison to other studies with Achillea species. The volatile oils exhibited high performances with range of inhibition zones (8.3–42.3 mm) and minimum inhibitory concentration values (2.25—144 μg/ml). Besides, a high correlation between antioxidant activity and phenolic content of A. gypsicola was found. These results suggest that A. gypsicola can be used as a safe source in the cosmetic, food and pharmaceutical industries.     

Retroviral Oligonucleotide Distributions Correlate with Biased Nucleotide Compositions of Retrovirus Sequences,Suggesting a Duplicative Stepwise Molecular Evolution

A computer-assisted analysis was made of 24 complete nucleotide sequences selected from the vertebrate retroviruses to represent the ten viral groups. The conclusions of this analysis extend and strengthen the previously made hypothesis on the Moloney murine leukemia virus: The evolution of the nucleotide sequence appears to have occurred mainly through at least three overlapping levels of duplication: (1) The distributions of overrepresented (3–6)-mers are consistent with the universal rule of a trend toward TG/CT excess and with the persistence of a certain degree of symmetry between the two strands of DNA. This suggests one or several original tandemly repeated sequences and some inverted duplications. (2) The existence of two general core consensuses at the level of these (3–6)-mers supports the hypothesis of a common evolutionary origin of vertebrate retroviruses. Consensuses more specific to certain sequences are compatible with phylogenetic trees established independently. The consensuses could correspond to intermediary evolutionary stages. (3) Most of the (3–6)-mers with a significantly higher than average frequency appear to be internally repeated (with monomeric or oligomeric internal iterations) and seem to be at least partly the cause of the bias observed by other researchers at the level of retroviral nucleotide composition. They suggest a third evolutionary stage by slippage-like stepwise local duplications. Received: 3 January 1996 / Accepted: 27 March 1996     

Effects of salinity on cell growth and docosahexaenoic acid content of the heterotrophic marine microalga Crypthecodinium cohnii

The effects of salinity on cell growth and docosahexaenoic acid (DHA) content of three marine microalgal strains, Crythecodinium cohnii ATCC 30556, C. cohnii ATCC 50051 and C. cohnii RJH were investigated. The lag phases of the three strains increased with increasing salinity in Porphyridium medium. The specific growth rate of C. cohnii ATCC 30556 was the highest at 9 g L⁻¹ NaCl while the other two strains had their highest specific growth rates at 5 g L⁻¹ NaCl. The highest cell dry weight concentrations of 2.51 g L⁻¹ and 1.56 g L⁻¹ were achieved at 9 g L⁻¹ NaCl for C. cohnii ATCC 30556 and ATCC 50051, respectively, while the highest dry weight concentration of 2.49 g L⁻¹ was achieved at 5 g L⁻¹ NaCl for C. cohnii RJH. The highest cell growth yield coefficient on glucose was 0.5 g g⁻¹ for both C. cohnii ATCC 30556 and C. cohnii RJH and 0.45 g g⁻¹ for C. cohnii ATCC 50051. All three strains responded to the change of salinity by modifying their cellular fatty acid compositions. At 9 g L⁻¹ NaCl, C. cohnii ATCC 30556 had the highest total fatty acid content and DHA (C22:6) proportion. In contrast, C. cohnii ATCC 50051 and C. cohnii RJH had the highest DHA content at 5 g L⁻¹ NaCl. C. cohnii ATCC 30556 and ATCC 50051 had the highest DHA yield (131.55 and 68.24 mg L⁻¹ respectively) at 9 g L⁻¹ NaCl while C. cohnii RJH had the highest DHA yield (128.83 mg L⁻¹) at 5 g L⁻¹ NaCl. Received 27 May 1999/ Accepted in revised form 27 August 1999