Baseline information on prokaryotic and microeukaryotic plankton communities inside and outside of Indonesian marine lakes

Marine lakes represent a unique and globally rare aquatic environment characterised by lower salinities and pH and higher temperatures than the surrounding open water environment. Here we provide baseline data on planktonic communities of Archaea, Bacteria and microeukaryotes inside and outside (open water habitat) of three marine lakes (Kakaban, Haji Buang and Tanah Bamban) in the Berau region of Indonesia. Compositional variation was highly congruent with the major axis of variation separating open water from marine lake samples for all three domains. Planktonic Archaea mainly consisted of OTUs assigned to Euryarchaeota that were closely related to organisms in Genbank previously obtained from seawater samples. The majority of archaeal OTUs were most abundant in open water habitat with a few OTUs abundant in all habitats. Most bacterial sequences were assigned to Proteobacteria, Cyanobacteria and Bacteroidetes with the percentage of Cyanobacteria highest in two of the marine lakes and lowest in the remaining lake (Tanah Bamban). In contrast to Archaea, there were a number of bacterial OTUs that were markedly more abundant in marine lake habitat. Most microeukaryote sequences were assigned to the Alveolata, Stramenopiles, Opisthokonta, Archaeplastida and Hacrobia. As was the case with Bacteria, a number of abundant microeukaryote OTUs were more abundant in marine lake habitat. Our results thus indicate similar compositional responses to the environmental conditions in marine lake habitat across the major domains of life and point to marine lakes harbouring distinct microbial communities.publishe

Correlations and Omori law in Spamming

The most costly and annoying characteristic of the e-mail communication system is the large number of unsolicited commercial e-mails, known as spams, that are continuously received. Via the investigation of the statistical properties of the spam delivering intertimes, we show that spams delivered to a given recipient are time correlated: if the intertime between two consecutive spams is small (large), then the next spam will most probably arrive after a small (large) intertime. Spam temporal correlations are reproduced by a numerical model based on the random superposition of spam sequences, each one described by the Omori law. This and other experimental findings suggest that statistical approaches may be used to infer how spammers operate.Comment: Europhysics Letters, to appea

Determination of phytoextraction potential of plant speciesfor toxic elements in soils of abandoned sulphide-mining areas

This study has determined contamination levels in soils and plants from the Sa˜o Domingos mining area, Portugal, by k0-INAA. Total concentrations of As, Sb, Cr, Hg, Cu, Zn and Fe in soils were very high, exceeding the maximum limits in Portuguese legislation. Concentrations of toxic elements like As, Sb and Zn were highest in roots of Erica andevalensis, Juncus acutus, Agrostis castellana and Nicotiana glauca. Additionally, As, Br, Cr, Fe, Sb and Zn in all organs of most plants were above toxicity levels. Those species that accumulated relatively high concentrations of toxic elements in roots (and tops) may be cultivated for phytostabilisation of similar areas

Informações sobre as cultivares de trigo recomendadas para plantio em 1988 no Rio Grande do Sul.

bitstream/item/119410/1/FOL-06007.pd

Strings from position-dependent noncommutativity

We introduce a new set of noncommutative space-time commutation relations in two space dimensions. The space-space commutation relations are deformations of the standard flat noncommutative space-time relations taken here to have position dependent structure constants. Some of the new variables are non-Hermitian in the most natural choice. We construct their Hermitian counterparts by means of a Dyson map, which also serves to introduce a new metric operator. We propose PTlike symmetries, i.e.antilinear involutory maps, respected by these deformations. We compute minimal lengths and momenta arising in this space from generalized versions of Heisenberg's uncertainty relations and find that any object in this two dimensional space is string like, i.e.having a fundamental length in one direction beyond which a resolution is impossible. Subsequently we formulate and partly solve some simple models in these new variables, the free particle, its PT-symmetric deformations and the harmonic oscillator.Comment: 11 pages, Late

On a partially reduced phase space quantisation of general relativity conformally coupled to a scalar field

The purpose of this paper is twofold: On the one hand, after a thorough review of the matter free case, we supplement the derivations in our companion paper on 'loop quantum gravity without the Hamiltonian constraint' with calculational details and extend the results to standard model matter, a cosmological constant, and non-compact spatial slices. On the other hand, we provide a discussion on the role of observables, focussed on the situation of a symmetry exchange, which is key to our derivation. Furthermore, we comment on the relation of our model to reduced phase space quantisations based on deparametrisation.Comment: 51 pages, 5 figures. v2: Gauge condition used shown to coincide with CMC gauge. Minor clarifications and correction

Dynamical noncommutativity

The model of dynamical noncommutativity is proposed. The system consists of two interrelated parts. The first of them describes the physical degrees of freedom with coordinates q^1, q^2, the second one corresponds to the noncommutativity r which has a proper dynamics. After quantization the commutator of two physical coordinates is proportional to the function of r. The interesting feature of our model is the dependence of nonlocality on the energy of the system. The more the energy, the more the nonlocality. The lidding contribution is due to the mode of noncommutativity, however, the physical degrees of freedom also contribute in nonlocality in higher orders in \theta.Comment: published versio

Metabolic adjustments in two Amazonian cichlids exposed to hypoxia and anoxia.

The effects of graded hypoxia on the physiological and biochemical responses were examined in two closely related species of cichlids of the Amazon: Astronotus crassipinnis and Symphysodon aequifasciatus. Ten fish of each species were exposed to graded hypoxia for 8 h in seven oxygen concentrations (5.92, 3.15, 1.54, 0.79, 0.60, 0.34, and 0.06 mg O2 L- 1), with the aim to evaluate hypoxia tolerance and metabolic adjustments, where plasma glucose and lactate levels, hepatic and muscle glycogen contents, and maximum enzyme activities (PK, LDH, MDH and CS) in skeletal and cardiac muscles were measured. Another experimental set was done to quantify oxygen consumption (MO2) and opercular movements in two oxygen concentrations. Hypoxia tolerance differed between the two species. Astronotus crassipinnis was able to tolerate anoxia for 178 min while S. aequifasciatus was able to withstand 222 min exposure in deep hypoxia (0.75 mg O2 L- 1). Suppressed MO2 was observed during exposure to 0.34 (A. crassipinnis) and 0.79 mg O2 L- 1 (S. aequifasciatus), while opercular movements increased in both species exposed to hypoxia. Higher levels of muscle and liver glycogen and larger hypoxia-induced increases in plasma glucose and lactate were observed in A. crassipinnis, which showed a higher degree of hypoxia tolerance. Changes in enzyme levels were tissue-specific and differed between species suggesting differential abilities in down-regulating oxidative pathways and increasing anaerobic metabolism. Based on the present data, we conclude that these animals are good anaerobes and highly adapted to their environment, which is allowed by their abilities to regulate metabolic pathways and adjust their enzyme levels