Seasonal Synechococcus and Thaumarchaeal population dynamics examined with high resolution with remote in situ instrumentation

Monterey Bay, CA is an Eastern boundary upwelling system that is nitrogen limited much of the year. In order to resolve population dynamics of microorganisms important for nutrient cycling in this region, we deployed the Environmental Sample Processor with quantitative PCR assays targeting both ribosomal RNA genes and functional genes for subclades of cyanobacteria (Synechococcus) and ammonia-oxidizing Archaea (Thaumarchaeota) populations. Results showed a strong correlation between Thaumarchaea abundances and nitrate during the spring upwelling but not the fall sampling period. In relatively stratified fall waters, the Thaumarchaeota community reached higher numbers than in the spring, and an unexpected positive correlation with chlorophyll concentration was observed. Further, we detected drops in Synechococcus abundance that occurred on short (that is, daily) time scales. Upwelling intensity and blooms of eukaryotic phytoplankton strongly influenced Synechococcus distributions in the spring and fall, revealing what appear to be the environmental limitations of Synechococcus populations in this region. Each of these findings has implications for Monterey Bay biogeochemistry. High-resolution sampling provides a better-resolved framework within which to observe changes in the plankton community. We conclude that controls on these ecosystems change on smaller scales than are routinely assessed, and that more predictable trends will be uncovered if they are evaluated within seasonal (monthly), rather than on annual or interannual scales.     

Algorithm of Regulatory Signal Recognition in DNA Sequences

An algorithm is proposed for extracting regulatory signals from DNA sequences. The algorithm complexity is nearly quadratic. The results of testing the algorithm on artificial and natural sequences are presented.     

NEW LIGHT ON THE SCALING OF METABOLIC RATE WITH THE SIZE OF ALGAE

The scaling of metabolic rate with the size of algae has been discussed and researched at length. The observation that algae usually have exponents b in the equation R = a· W ^{− b} (where R is the specific growth rate, W is the organism [cell] biomass, and a and b are constants) equal to or higher than the value of −0.25 for many other organisms is generally related to resource-saturated (maximal) values of R. Recent work has shown that the exponent b for light-limited growth is more negative than −0.25. This was predicted from considerations of the package effect in photon absorption, as modulated by the volume-specific pigment content of the cells, and the photosynthetic unit size. Further work is needed to extrapolate these findings to fluctuating light environments. This minireview puts the recent work into a broader context and suggests how further work could quantify the roles of optical thickness and of spatial and temporal variations in the radiation field in determining metabolic rates.     

Evolutionary history of the polyploid complex of Cardamine amara (Brassicaceae): isozyme evidence

 In samples from 56 populations of Cardamine amara, representing four diploid subspecies (subspp. amara, opicii, balcanica, and pyrenaea) and two tetraploid subspecies (subspp. austriaca and olotensis) from different parts of the European distribution area, four enzyme systems with 23 alleles were studied. These data, together with previous morphological and karyological data, suggest that the distribution and variation pattern within the species was strongly influenced by the last glacial period and postglacial migrations. Cardamine amara subsp. pyrenaea is monomorphic for a unique allele, and subsp. balcanica has a unique allele, too which, however, is not fixed in all populations of the taxon. Both taxa seem to be relic ones, although otherwise subsp. balcanica in respect of allelic spectrum much resembles subsp. amara. The other two diploid subspecies, subsp. amara and subsp. opicii, are not characterised by presence of unique alleles but differ in allele frequencies. The two tetraploid subspecies have different evolutionary histories. C. amara subsp. austriaca seems to be an autopolyploid derivative of subsp. amara which colonised open space offered by retreating glaciers in the Eastern Alps. C. amara subsp. olotensis from the Iberian Peninsula represents most probably a polyploid of preglacial time. Received June 22, 2001; accepted May 17, 2002 Published online: September 13, 2002     

Metabolite control of Sorghum C4 phosphoenolpyruvate carboxylase catalytic activity and phosphorylation state

Kinetic analyses were performed on the nonphosphorylated and in vitro phosphorylated forms of recombinant Sorghum C4 phospho enolpyruvate carboxylase (C4 PEPC). The native enzyme was purified by immunoaffinity chromatography and its integrity demonstrated by Western blot analyses using anti N- and C-terminus antibodies. At suboptimal pH (7.1 to 7.3) and PEP concentration (2.5 mM), phosphorylation, positive metabolite effectors e.g., glucose-6-phosphate, glycine and dihydroxyacetone-phosphate, or an increase in pH strongly activated the enzyme and lowered the inhibitory effect of L-malate. C4 PEPC phosphorylation strengthened the effect of the positive effectors thereby decreasing further the enzyme's sensitivity to this inhibitor. L-malate also decreased the phosphorylation rate of C4 PEPC, a process antagonized by positive metabolite effectors. This was shown both in vitro, in a reconstituted phosphorylation assay containing the catalytic subunit of a cAMP-dependent protein kinase or the Sorghum leaf PEPC-PK and in situ, during induction of C4 PEPC phosphorylation in mesophyll cell protoplasts.     

Chemical basis of nest-mate discrimination in the ant Formica exsecta.

Distinguishing nest-mates from non-nest-mates underlies key animal behaviours, such as territoriality, altruism and the evolution of sociality. Despite its importance, there is very little empirical support for such a mechanism in nature. Here we provide data that the nest-mate recognition mechanism in an ant is based on a colony-specific Z9-alkene signature, proving that surface chemicals are indeed used in ant nest-mate recognition as was suggested 100 years ago. We investigated the cuticular hydrocarbon profiles of 10 Formica exsecta colonies that are composed almost entirely of a Z9-alkene and alkane component. Then we showed that worker aggression is only elicited by the Z9-alkene part. This was confirmed using synthetic Z9-alkene and alkane blends matched to the individual colony profiles of the two most different chemical colonies. In both colonies, only glass beads with 'nest-mate' alkene profiles received reduced aggression. Finally, changing the abundance of a single Z9-alkene on live ants was shown to significantly increase the aggression they received from nest-mates in all five colonies tested. Our data suggest that nest-mate discrimination in the social insects has evolved to rely upon highly sensitive responses to relatively few compounds.     

Information and Communication Technology‐Enabled Low Carbon Technologies

This article outlines the subsector of the information and communication technology (ICT) industry concerned with reducing the economy's environmental impact, dubbed ICT‐enabled low carbon technologies (ICTeLCTs). The article is based on a study funded by United Kingdom (UK) Trade and Investment, a division of the UK Department for Business, Innovation and Skills. ICTeLCTs can be segmented into specialist and generalist operators. Specialists focus on one or two ICT applications to monitor or reduce environmental issues, while generalists supply products and services enabling a firm or a private household to reduce the environmental impact of its activities. The subsector can be further segmented into green ICT, energy management, building management, carbon accounting, waste management, intelligent transport systems (ITSs), and water management. The main factors driving ICTeLCTs include legislation, voluntary environmental standards, corporate social responsibility (CSR) activities, customer demand, and competitive market factors. Policy makers should continue to drive the growth of ICTeLCTs with the introduction and refinement of environmental legislation regulating energy use and markets.     

Drugs to cure avian influenza infection – multiple ways to prevent cell death

New treatments and new drugs for avian influenza virus (AIV) infection are developed continually, but there are still high mortality rates. The main reason may be that not all cell death pathways induced by AIV were blocked by the current therapies. In this review, drugs for AIV and associated acute respiratory distress syndrome (ARDS) are summarized. The roles of antioxidant (vitamin C) and multiple immunomodulators (such as Celecoxib, Mesalazine and Eritoran) are discussed. The clinical care of ARDS may result in ischemia reperfusion injury to poorly ventilated alveolar cells. Cyclosporin A should effectively inhibit this kind of damages and, therefore, may be the key drug for the survival of patients with virus-induced ARDS. Treatment with protease inhibitor Ulinastatin could also protect lysosome integrity after the infection. Through these analyses, a large drug combination is proposed, which may hypothetically greatly reduce the mortality rate.     

Overexpression of a novel osteopetrosis-related gene CCDC154 suppresses cell proliferation by inducing G2/M arrest

Osteopetrosis, a disorder of skeletal bone, can cause death during childhood. We previously described a new spontaneous autosomal recessive osteopetrosis mouse mutant, “new toothless” (ntl). In this study, we reported for the first time the identification, cloning and characterization of the coiled-coil domain-containing 154 (CCDC154), a novel gene whose deletion of ~5 kb sequence including exons 1–6 was completely linked to the ntl mutant. The CCDC154 was conserved between mouse and human and is wildly expressed in mouse tissues. The cellular localization of CCDC154 was in the early endosomes. Overexpression of CCDC154 inhibited cell proliferation of HEK293 cells by inducing G₂/M arrest. CCDC154 also inhibited tumor cell growth, and the soft agar assay revealed a significant decrease of the colony size of Hela cells upon transfection of CCDC154. Our results indicate that CCDC154 is a novel osteopetrosis-related gene involved in cell cycle regulation and tumor suppression growth.