Bacterial Diversity in Old Hydrocarbon Polluted Sediments of Ecuadorian Amazon River Basins.

The Ecuadorian Amazon rainforest stands out as one of the world's most biodiverse regions, yet faces significant threats due to oil extraction activities dating back to the 1970s in the northeastern provinces. This research investigates the environmental and societal consequences of prolonged petroleum exploitation and oil spills in Ecuador's Amazon. Conducted in June 2015, the study involved a comprehensive analysis of freshwater sediment samples from 24 locations in the Rio Aguarico and Napo basins. Parameters such as water and air temperature, conductivity, soil pH, and hydrocarbon concentrations were examined. Total petroleum hydrocarbon (TPH) concentrations ranged from 9.4 to 847.4 mg kg-1, with polycyclic aromatic hydrocarbon (PAH) levels varying from 10.15 to 711.1 mg kg-1. The pristane/phytane ratio indicated historic hydrocarbon pollution in 8 of the 15 chemically analyzed sediments. Using non-culturable techniques (Illumina), bacterial analyses identified over 350 ASV, with prominent families including Comamonadaceae, Chitinophagaceae, Anaeromyxobacteraceae, Sphingomonadaceae, and Xanthobacteraceae. Bacterial diversity, assessed in eight samples, exhibited a positive correlation with PAH concentrations. The study provides insights into how microbial communities respond to varying levels of hydrocarbon pollution, shedding light on the enduring impact of oil exploitation in the Amazonian region. Its objective is to deepen our understanding of the environmental and human well-being in the affected area, underscoring the pressing need for remedial actions in the face of ongoing ecological challenges.

Wavelength synergistic effects in continuous flow-through water disinfection systems.

The past decade's development of UV LEDs has fueled significant research in water disinfection, with widespread debate surrounding the potential synergies of multiple UV wavelengths. This study analyses the use of three UV sources (265, 275, and 310 nm) on the inactivation of Escherichia coli bacteria in two water matrixes. At maximum intensity in wastewater, individual inactivation experiments in a single pass set-up (Flow rate = 2 L min-1, Residence time = 0.75 s) confirmed the 265 nm light source to be the most effective (2.2 ± 0.2 log units), while the 310 nm led to the lowest inactivation rate (0.0003 ± 7.03×10-5 log units). When a combination of the three wavelengths was used, an average log reduction of 4.4 ± 0.2 was observed in wastewater. For combinations of 265 and 275 nm, the average log reductions were similar to the sum of individual log reductions. For combinations involving the use of 310 nm, a potential synergistic effect was investigated by the use of robust statistical analysis techniques. It is concluded that combinations of 310 nm with 265 nm or 275 nm devices, in sequential and simultaneous mode, present a significant synergy at both intensities due to the emission spectra of the selected LEDs, ensuring the possibility of two inactivation mechanisms. Finally, the electrical energy per order of inactivation found the three-wavelength combination to be the most energy efficient (0.39 ± 0.05, 0.36 ± 0.01 kWh m-3, at 50% and 100% dose, respectively, in wastewater) among the synergistic combinations.

Biodegradation of clopidogrel bisulfate by Pseudomonas aeruginosa and Pseudomonas putida strains isolated from Algerian wastewater.

The clopidogrel bisulfate was degraded under aerobic conditions by two bacterial strains isolated from industrial effluents in El-Harrach, Algeria. The sequencing of their 16S rRNA revealed that these two strains are Pseudomonas aeruginosa and Pseudomonas putida. The experiments showed that this consortium could remove clopidogrel bisulfate at high concentrations (5-1500 mg·L-1) within 96 h incubation period. The HPLC analysis recorded 75.23% degradation of clopidogrel bisulfate at an initial concentration of 100 mg·L-1 after five days of incubation at pH 7.0 and a temperature of 30 °C. Also, a maximum degradation of 99.08% was carried out at a more basic pH (8.5). While only 41% was degraded at a temperature of 20 °C. Moreover, the presence of supplemental sources of carbon and nitrogen in the mixed culture media effectively improved the biodegradation of clopidogrel bisulfate by the stains. Finally, the morphology of the strains and the properties of the cell's surface were studied using a scanning electron microscope (SEM). This study reports, for the first time, the viability of the aerobic biodegradation of clopidogrel bisulfate in water in a wide range of concentrations.

Novel Biorefinery Approach for Phycocyanin Extraction and Purification and Biocrude Production from Arthrospira platensis.

A new biorefinery from Arthrospira platensis was proposed to obtain phycocyanin (PC) and a biocrude by hydrothermal liquefaction (HTL). PC is a high-added-value phycobiliprotein widely used as a food colorant and in the nutraceutical and pharmaceutical industries. However, the use of conventional solvents in the extraction process and the purity grade of the extract are shortcomings in bioproduct production. PC was extracted using a reusable ionic liquid [EMIM][EtSO4], achieving a PC purity of the lowest commercial grade. Therefore, two downstream processes were applied: (1) dialysis + precipitation and (2) aqueous two-phase system (ATPS) + dialysis + precipitation. After the second purification process, the PC purity increased remarkably to reach the analytical grade for pharmaceutical and nutraceutical applications. The waste biomass (WB) obtained in the PC extraction was valorized by hydrothermal liquefaction (HTL) to produce a biocrude. The biocrude yield and composition remarkably enhanced using isopropanol at 350 °C as a cosolvent.

Coupling phytoremediation of Pb-contaminated soil and biomass energy production: A comparative Life Cycle Assessment.

Phytoremediation is an in-situ remediation technology based on the ability of plants to fix pollutants from the soil. In this sense, plants such as Festuca arundinacea are a promising for heavy metal removal in contaminated soils. The present work studies phytoremediation for Pb removal from a contaminated soil located in Spain using F. arundinacea by applying the Life Cycle Assessment (LCA) approach. Two different options for biomass management were assessed: direct disposal in a security landfill (case 1A) and energy recovery (case 1B). For the latter option, cogeneration was simulated using SuperPro Designer 9.5. In addition, traditional treatments such as soil washing (case 2) and excavation + landfill (case 3) were evaluated in terms of environmental impacts by LCA. The former was simulated using SuperPro Designer 9.5, whereas data from literature were used for the latter to perform the LCA. Results showed that biomass disposal in a landfill was the most important contributor to the overall impact in case 1A. In contrast, biomass conditioning and cogeneration were the main steps responsible for environmental impacts in case 1B. Comparing cases 1A and 1B, the energy recovery from biomass was superior to direct landfill disposal, reducing the environmental impacts in most of the studied categories. Regarding the rest of the treatments, chemical production and soil disposal presented the most critical environmental burdens in cases 2 and 3, respectively. Finally, the comparison between the studied cases revealed that phytoextraction + energy recovery was the most environmentally friendly option for the studied conditions, reducing impacts by 30-100%.

Antiparasitic Effects of Potentially Toxic Beetles (Tenebrionidae and Meloidae) from Steppe Zones.

Arthropods and specifically beetles can synthesize and/or sequester metabolites from dietary sources. In beetle families such as Tenebrionidae and Meloidae, a few studies have reported species with toxic defensive substances and antiparasitic properties that are consumed by birds. Here we have studied the antiparasitic activity of extracts from beetle species present in the habitat of the Great Bustard (Otis tarda) against four pathogen models (Aspergillus niger, Meloidogyne javanica, Hyalomma lusitanicum, and Trichomonas gallinae). The insect species extracted were Tentyria peiroleri, Scaurus uncinus, Blaps lethifera (Tenebrionidae), and Mylabris quadripunctata (Meloidae). M. quadripunctata exhibited potent activity against M. javanica and T. gallinae, while T. peiroleri exhibited moderate antiprotozoal activity. The chemical composition of the insect extracts was studied by gas chromatography coupled with mass spectrometry (GC-MS) analysis. The most abundant compounds in the four beetle extracts were hydrocarbons and fatty acids such as palmitic acid, myristic acid and methyl linoleate, which are characteristic of insect cuticles. The presence of cantharidin (CTD) in the M. quadripunctata meloid and ethyl oleate (EO) in T. peiroleri accounted for the bioactivity of their extracts.

Characterization of genetic diversity and clonal complexes by whole genome sequencing of Mycobacterium tuberculosis isolates from Jalisco, Mexico.

Whole genome sequencing (WGS) analysis in tuberculosis allows the prediction of drug-resistant phenotypes, identification of lineages, and to better understanding of the epidemiology and transmission chains. Nevertheless the procedure has been scarcely assessed in Mexico, in this work we analyze by WGS isolates of Mycobacterium tuberculosis circulating in Jalisco, Mexico. Lineage and phylogenetic characterization, drug resistant prediction, "in silico" spoligotyping determination, were provided by WGS in 32 M. tuberculosis clinical isolates. Lineage 4 (L4), with 28 isolates (87%) and eleven sublineages was dominant. Forty SNPs and INDELs were found in genes related to first-, and second-line drugs. Eleven isolates were sensitive, seven (22%) were predicted to be resistant to isoniazid, two resistant to rifampicin (6%) and two (6%) were multidrug-resistant tuberuclosis. Spoligotyping shows that SIT 53 (19%) and SIT 119 (16%) were dominant. Four clonal transmission complexes were found. This is the first molecular epidemiological description of TB isolates circulating in western Mexico, achieved through WGS. L4 was dominant and included a high diversity of sublineages. It was possible to track the transmission route of two clonal complexes. The WGS demonstrated to be of great utility and with further implications for clinical and epidemiological study of TB in the region.

Bacterial diversity in aqueous/sludge phases within diesel fuel storage tanks.

Diesel fuel storage tanks are not hostile environments for microorganisms and tend to form sludges in the water deposited at the bottom of the tanks. The lack of nutrient, carbon and energy limitations within these habitats boost the abundance and the metabolic activity of microorganisms providing microbial hotspots with high growing rates of diesel degradation (0.10 ± 0.021 d-1). Five different Phyla (Thermotogae, Spirochaetes, Firmicutes, Bacteroidetes Proteobacteria) were identified within the aqueous/sludge phase from in situ diesel storage tanks, by cultured independent molecular surveys using the 16S rDNA gene fragment. The identified dominant strains were Geotoga aestuarianus, Flavobacterium ceti, Spirochaeta thermophila, Propionispira arboris, Sporobacterium olearium and Dysgonomonas genera. The altitude where the storage tanks are located and the organic carbon concentration within the aqueous/sludge phases affected the bacterial diversity. Therefore, the more diverse the microbial communities are, the more probability of the presence of bacteria with capacity to metabolized diesel and eliminate organic matter. Despite, only phosphate showed an effect on the bacterial distribution within the storage tanks, there was an apparent lack of deterministic process in structuring microbial communities. Consequently, preventative protocols are a priority to avoid the microbial growth within diesel fuel storage tanks. A new focus of this worldwide problem within the oil industry would be to explore deeply the wide range of metabolic and adaptive capacities of these microorganisms. These microbial consortia are potential tools with new specific services to apply in bioremediation among others.

p21-Activated Kinases in Thyroid Cancer.

The family of p21-activated kinases (PAKs) are oncogenic proteins that regulate critical cellular functions. PAKs play central signaling roles in the integrin/CDC42/Rho, ERK/MAPK, PI3K/AKT, NF-κB, and Wnt/ß-catenin pathways, functioning both as kinases and scaffolds to regulate cell motility, mitosis and proliferation, cytoskeletal rearrangement, and other cellular activities. PAKs have been implicated in both the development and progression of a wide range of cancers, including breast cancer, pancreatic melanoma, thyroid cancer, and others. Here we will discuss the current knowledge on the structure and biological functions of both group I and group II PAKs, as well as the roles that PAKs play in oncogenesis and progression, with a focus on thyroid cancer and emerging data regarding BRAF/PAK signaling.

Cultivation of Microalgae and Cyanobacteria: Effect of Operating Conditions on Growth and Biomass Composition.

The purpose of this work is to define optimal growth conditions to maximise biomass for batch culture of the cyanobacterium Arthrospira maxima and the microalgae Chlorella vulgaris, Isochrysis galbana and Nannochloropsis gaditana. Thus, we study the effect of three variables on cell growth: i.e., inoculum:culture medium volume ratio (5:45, 10:40, 15:35 and 20:30 mL:mL), light:dark photoperiod (8:16, 12:12 and 16:8 h) and type of culture medium, including both synthetic media (Guillard's F/2 and Walne's) and wastewaters. The results showed that the initial inoculum:culture medium volume ratio, within the range 5:45 to 20:30, did not affect the amount of biomass at the end of the growth (14 days), whereas high (18 h) or low (6 h) number of hours of daily light was important for cell growth. The contribution of nutrients from different culture media could increase the growth rate of the different species. A. maxima was favoured in seawater enriched with Guillard's F/2 as well as C. vulgaris and N. gaditana, but in freshwater medium. I. galbana had the greatest growth in the marine environment enriched with Walne's media. Nitrogen was the limiting nutrient for growth at the end of the exponential phase of growth for C. vulgaris and N. gaditana, while iron was for A. maxima and I. galbana. The growth in different synthetic culture media also determines the biochemical composition of each of the microalgae. All species demonstrated their capability to grow in effluents from a wastewater treatment plant and they efficiently consume nitrogen, especially the three microalga species.

Avian Scavengers as Bioindicators of Antibiotic Resistance due to Livestock Farming Intensification.

Industrial food animal production uses huge amounts of antibiotics worldwide. Livestock, their excreta used for manure and meat subproducts not intended for human consumption can all play important roles in the transmission of bacterial resistance to wildlife. Vultures and other scavengers can be directly exposed to active antibiotics ingested while feeding on livestock carcasses. This study evaluates whether bacterial resistance in the red kite (Milvus milvus) differs between two wintering areas selected based on patent differences in farming practices-particularly in the industrial production of food animals (primarily swine and poultry) vs. scarce and declining sheep herding. The results support the hypothesis that intensification in food animal production is associated with increased bacterial multidrug resistance in wildlife. Resistance was positively correlated with time elapsed since the beginning of the commercial application of each antibiotic in human and veterinary medicine, with clear differences depending on farming intensification between areas. Monitoring programs are encouraged to use red kites and other avian scavengers as valuable sentinels of contamination by antibiotics and clinically relevant resistant pathogens from livestock operations of variable intensities. Farms authorized for supplementary feeding of threatened scavengers should avoid supplying carcasses with active antibiotic residues to avoid bacterial resistance in scavenger wildlife.

Stability of Selected Hydrogen Bonded Semiconductors in Organic Electronic Devices.

The electronics era is flourishing and morphing itself into Internet of Everything, IoE. At the same time, questions arise on the issue of electronic materials employed: especially their natural availability and low-cost fabrication, their functional stability in devices, and finally their desired biodegradation at the end of their life cycle. Hydrogen bonded pigments and natural dyes like indigo, anthraquinone and acridone are not only biodegradable and of bio-origin but also have functionality robustness and offer versatility in designing electronics and sensors components. With this Perspective, we intend to coalesce all the scattered reports on the above-mentioned classes of hydrogen bonded semiconductors, spanning across several disciplines and many active research groups. The article will comprise both published and unpublished results, on stability during aging, upon electrical, chemical and thermal stress, and will finish with an outlook section related to biological degradation and biological stability of selected hydrogen bonded molecules employed as semiconductors in organic electronic devices. We demonstrate that when the purity, the long-range order and the strength of chemical bonds, are considered, then the Hydrogen bonded organic semiconductors are the privileged class of materials having the potential to compete with inorganic semiconductors. As an experimental historical study of stability, we fabricated and characterized organic transistors from a material batch synthesized in 1932 and compared the results to a fresh material batch.

Biodegradation of anionic surfactants by Alcaligenes faecalis, Enterobacter cloacae and Serratia marcescens strains isolated from industrial wastewater.

Pseudo-persistent organic pollutants, such as anionic surfactants (AS), are nowadays among the more complex problems that threaten the aquatic environments and other environmental compartments. The present work describes the identification and efficiency of a consortium, isolated from Algerian industrial wastewater, to remove three anionic surfactants (i.e., sodium dodecylbenzenesulfonate (SDBS), sodium dodecyl sulfate (SDS) and sodium lauryl ether sulfate (SLES)). The genetic analysis of 16S rRNA indicated that these strains are Alcaligenes faecalis, Enterobacter cloacae and Serratia marcescens. Under aerobic conditions, pH 7.0 and optimum temperature of 30 °C, the mixed consortium allowed to degrade 85.1% of initial SDBS amount after 144 h of incubation with half-life of 20.8 h. While E. cloacae and S. marcescens pure strains eliminated 46% and 41% less SDBS respectively. Evenly, SDS was degraded at only 23.71% by A. faecalis strain. However, the degradation capacity of SDS by the consortium was very high (94.2%) with a half-life of 9.8 h. The SLES anionic surfactant showed a lower biodegradation by the consortium (47.53%) due to the presence of ether oxide units in the chemical structure of SLES which induced toxicity to the medium. The investigation of the biodegradation of this type of organic pollutants by microorganisms has recently become a key issue for the environmental protection area.

Influence of habitat suitability and sex-related detectability on density and population size estimates of habitat-specialist warblers.

Knowledge about the population size and trends of common bird species is crucial for setting conservation priorities and management actions. Multi-species large-scale monitoring schemes have often provided such estimates relying on extrapolation of relative abundances in particular habitats to large-scale areas. Here we show an alternative to inference-rich predictive models, proposing methods to deal with caveats of population size estimations in habitat-specialist species, reed warblers (Acrocephalus scirpaceus and Acrocephalus arundinaceus). Reed warblers were only found in pure reedbeds within riparian woodlands or in riparian vegetation scattered within or around reedbed patches, as expected according to their habitat specialization. The proportion of individuals located in reedbed associated with lotic and lentic waters differed between species, and no reed warbler was recorded in reedbed located along dry streams. This indicates that microhabitat features or their effects on reedbed structure and other factors made a proportion of the apparently available habitat unsuitable for both warbler species. Most warblers detected were males performing territorial singing (females seldom sing and do not perform elaborate territorial song, and are undistinguishable from males by plumage). The regional population sizes of the warbler species (~4000 individuals of A. scirpaceus and ~ 1000 individuals of A. arundinaceus) were much smaller than those estimated for the same area by transforming relative abundance obtained at a national scale to population size through extrapolation by habitat at a regional scale. These results highlight the importance of considering the habitat actually used and its suitability, the manner of sex-related detection, population sex-ratio and their interactions in population estimates. Ideally, the value of predictive methods to estimate population size of common species should be tested before conducting large-scale monitoring, rather than a posteriori. Although logistically challenging, this can be achieved by designing monitoring programs including an intensive sampling of abundance in ad hoc reference areas of variable size.

A simple capillary viscometer based on the ideal gas law.

We report a simple, inexpensive and user-friendly capillary viscometer based on the measurement of pressure drop in capillary tubing using the principle of ideal gas law. Viscosity is an important physical property of a fluid that provides molecular information of the fluid's behavior under flow conditions. Measuring viscosity, however, generally requires relatively large fluid volume samples and is expensive with commercial viscometers. Microfluidic viscometers at different levels of complexity can measure fluids at different flow rates with a small sample volume but the cost of commercially available microfluidic viscometers is still high. The reported capillary viscometer is cost-effective, uses small amounts of sample fluid and can measure viscosity under various shear rates. According to the Hagen-Poiseuille equation, the pressure drop of laminar flows in a capillary at a given flow rate is proportional to the viscosity of the fluid. When an enclosed air volume is connected to the upstream of the capillary, the pressure drop can be calculated with the change of the connected air volume, which is reflected by the displacement change of the air-liquid interface in the connecting capillary to the enclosed air volume. Based on these principles, the viscometer was assembled with readily accessible materials, and required no internal sensors or extensive programming. Measurements were successfully performed for five liquids including water, acetone, 2% fat milk, glycerin 30% and glycerin 40%. Except for acetone, the difference between measured and known viscosity was within 4% and highly consistent, well within the 13% uncertainty errors of readily accessible laboratory materials. Overall, the simple viscometer was easily assembled with low cost materials, was portable and accurate, and provided an alternative to expensive commercial viscometers. Finally, the simple capillary viscometer was a good outreach project for K-12 students to understand fluid behavior.

Biodegradation of polycyclic aromatic hydrocarbons (PAHs) by laccase from Trametes versicolor covalently immobilized on amino-functionalized SBA-15.

A covalent immobilization method based on glutaraldehyde and amino-functionalized SBA-15 supports has been successfully applied to covalently and stably immobilize laccase from Trametes versicolor. The resultant biocatalysts displayed high incorporation yields of enzyme and led to excellent biodegradation rates of selected HPAs models, i.e. naphthalene, phenanthrene and anthracene, in water. The nature of the hydrocarbon chain accompanying the amino group has been shown as determinant for the immobilization as well as for the activity and reusability of the materials. Thus, alkyl moieties displayed higher enzyme loadings than phenyl moieties, being more adequate the larger n-butyl tethering residue likely due to its higher mobility. Using the aminobutyl-based laccase-SBA-15, 82%, 73%, and 55% conversion of naphthalene, phenanthrene and anthracene, respectively, were achieved after 48 h, very close to the values obtained with free laccase under the same reaction conditions. On the other hand, aminopropyl-based laccase-SBA-15 biocatalysts displayed the best reusability properties, retaining higher activity after four repeated uses than the corresponding aminobutyl-based materials.

Males of a strongly polygynous species consume more poisonous food than females.

We present evidence of a possible case of self-medication in a lekking bird, the great bustard Otis tarda. Great bustards consumed blister beetles (Meloidae), in spite of the fact that they contain cantharidin, a highly toxic compound that is lethal in moderate doses. In addition to anthelminthic properties, cantharidin was effective against gastrointestinal bacteria that cause sexually-transmitted diseases. Although both sexes consumed blister beetles during the mating season, only males selected them among all available insects, and ingested more and larger beetles than females. The male-biased consumption suggests that males could use cantharidin to reduce their parasite load and increase their sexual attractiveness. This plausibly explains the intense cloaca display males perform to approaching females, and the meticulous inspection females conduct of the male's cloaca, a behaviour only observed in this and another similar species of the bustard family. A white, clean cloaca with no infection symptoms (e.g., diarrhoea) is an honest signal of both, resistance to cantharidin and absence of parasites, and represents a reliable indicator of the male quality to the extremely choosy females. Our results do not definitely prove, but certainly strongly suggest that cantharidin, obtained by consumption of blister beetles, acts in great bustards as an oral anti-microbial and pathogen-limiting compound, and that males ingest these poisonous insects to increase their mating success, pointing out that self-medication might have been overlooked as a sexually-selected mechanism enhancing male fitness.

Características clínicas de pacientes llevados a monitoría externa de eventos / Clinical characteristics of patients undergoing external monitoring of events

Para la evaluación del paciente con síntomas que sugieran arritmia cardiaca existen varios métodos que pueden ser utilizados. En ese sentido, los monitores externos de eventos pueden mejorar la sensibilidad del diagnóstico. Se realizó un estudio descriptivo, retrospectivo y transversal, que incluyó la revisión de resultados de la monitoría externa de eventos de 203 pacientes. El motivo más común por el cual se solicitó el monitor externo de eventos fueron las palpitaciones en 161 pacientes (79,3%), seguidas por síncope en 21 pacientes (10,3%). El diagnóstico más habitual fue el ritmo sinusal normal sin otras alteraciones en 59 pacientes (29%), seguido por taquicardia sinusal en 54 (26,6%), extrasistolia ventricular en 24 (11,8%), extrasistolia auricular en 17 (8,3%), taquicardia auricular no sostenida en 12 (5,9%) y, en forma menos frecuente, taquicardia supraventricular en 8 (3,94%), taquicardia ventricular no sostenida en 5 (2,4%) y trastorno de la conducción interventricular en 6 (2,9%). Este es el primer estudio descriptivo de la monitoría externa de eventos llevado a cabo en Colombia. Desde el punto de vista epidemiológico y de diagnóstico electrocardiográfico, los hallazgos son similares a los resultados de estudios previos, con las limitaciones que ofrece un análisis de este tipo.

There are a variety of methods that can be used for the evaluation of patients with symptoms suggestive of cardiac arrhythmia; in this regard, external monitoring of events can improve the sensitivity of diagnosis. A descriptive, retrospective and cross-sectional study, which included review of the results of external monitoring of events of 203 patients was performed. The most common reason for requesting external monitoring of events was palpitations in 161 patients (79.3%), followed by syncope in 21 patients (10.3%). The most common diagnosis was normal sinus rhythm with no other abnormalities in 59 patients (29%), followed by sinus tachycardia in 54 (26.6%), ventricular extrasystoles in 24 (11.8%), atrial extrasystoles in 17 (8.3%), non-sustained atrial tachycardia in 12 (5.9%), and less frequently supraventricular tachycardia in 8 (3.94%), non-sustained ventricular tachycardia in 5 patients (2.4%) and interventricular conduction disturbance in 6 (2.9%). This is the first descriptive study of external monitoring of events held in Colombia. From the epidemiological and diagnosis electrocardiographic point of view, the findings are similar to results of previous studies, with the limitations that provides this type of analysis.

Need and seek for dietary micronutrients: endogenous regulation, external signalling and food sources of carotenoids in new world vultures.

Among birds, vultures show low concentrations of plasma carotenoids due to the combination of their large size, general dull colouration and a diet based on carrion. We recorded the concentration of each carotenoid type present in plasma of the Andean condor (Vultur gryphus) according to age and sex, that determine colour signalling and dominance hierarchies in the carcasses. We compared the carotenoid profile in wild condors with that of captive condors fed with a controlled diet of flesh to test the hypothesis that wild individuals could acquire extra carotenoids from vegetal matter contained in carcass viscera and fresh vegetation. Wild American black vultures (Coragyps atratus) were also sampled to evaluate the potential influence of colouration in the integument on absorption and accumulation patterns of plasma carotenoids. A remarkably higher concentration of lutein than ß-carotene was found in wild condors, while the contrary pattern was recorded in American black vultures and captive condors. We found a consistent decrease in all plasma carotenoids with age, and a lower concentration of most xanthophylls in male compared to female wild condors. Positive correlations of all carotenoids indicated general common absorption and accumulation strategies or a single dietary source containing all pigments found in plasma. The comparatively low total concentration of carotenoids, and especially of lutein rather than ß-carotene, found in captive condors fed with a diet restricted to flesh supports the hypothesis that Andean condors can efficiently acquire carotenoids from vegetal matter in the wild. Andean condors seem to be physiologically more competent in the uptake or accumulation of xanthophylls than American black vultures, which agrees with the use of colour-signalling strategies in sexual and competitive contexts in the Andean condor. This study suggests that vultures may use dietary vegetal supplements that provide pigments and micronutrients that are scarce or missing in carrion.

Biodegradation of high-molecular-weight polycyclic aromatic hydrocarbons by a wood-degrading consortium at low temperatures.

This study evaluates the ability of two bacterial consortia (C2PL05 and BOS08), extracted from very different environments, to degrade low- (naphthalene, phenanthrene, anthracene) and high- (pyrene, perylene) molecular-weight polycyclic aromatic hydrocarbons (PAHs) at high (15-25 °C) and low (5-15 °C) temperature ranges. C2PL05 was isolated from a soil in an area chronically and heavily contaminated with petroleum hydrocarbons and BOS08 from decomposing wood in an unpolluted forest, free of PAHs. Bacterial consortia were described by cultivable and noncultivable techniques (denaturing gradient gel electrophoresis). Fungal DNA was not observed within the wood-decomposing consortium and fungal activity was therefore negligible during most of the PAH degradation process. PAH-degrading bacterial populations, measured by most probable number enumeration, increased during the exponential phase. Toxicity estimated by the Microtox method was reduced to low levels and final PAH depletion, determined by HPLC, confirmed the high degree (54% and 99%, respectively) of low- and high-molecular-weight PAH degradation capacity of the two consortia. PAH-degrading capacity was also confirmed at low temperatures, and especially by consortium BOS08 not previously exposed to those toxic compounds, where strains of Acinetobacter sp., Pseudomonas sp., Ralstonia sp. and Microbacterium sp. were identified.