Heavy Metals in Macroalgae of Havana's Northern Littoral,Cuba

Copper, iron, lead, manganese, and zinc contents were determined in various phyla of macroalgae typical of the rocky mesolittoral zone of Cuba and widely distributed in the Caribbean Region. the samples were collected in different zones along the shores of Havana City which are more or less influenced by anthropogenic activities. Differences in metal contents were observed due to seasonal variations and differences between sampling sites. of the analyzed species, only one brown alga, Padina vickersiae is considered as a suitable candidate for the monitoring of metal contamination.     

Safe betting: males help dull females only when they raise high-quality offspring

In evolutionary biology, whether parents should enhance or reduce parental care according to mate ornamentation is a subject of great debate. However, the evolution of female ornaments can shed light on this question. In theory, female ornamentation should be traded off against fecundity and thus cannot be wholly informative to males without a direct indication of fecundity. Hence, direct cues of offspring quality should affect the relationship between male investment and female ornamentation. Under this hypothesis, we manipulated two direct cues of offspring quality (egg size and color) after first egg laying in the blue-footed booby and registered male incubation patterns. In this species, foot color is a dynamic signal of current condition and in females is traded off with egg size. We found that males spent more time incubating when paired with dull females but only in nests with large eggs. Males also spent less time incubating small dull eggs. Results indicate that egg size, a direct cue of reproductive value, affected the relationship between male effort and female ornamentation. Males may be willing to help females that have invested in offspring at the expense of ornamentation, which suggests compensation when females are in low condition. Another possibility is that males relax their effort when paired with highly ornamented and fecund females because they have high parenting abilities. Our findings suggest that the information conveyed by female ornaments may depend on direct cues of fecundity. Results also highlight that parental decisions are complex, modulated by a combination of information sources.     

Biliverdin-based egg coloration is enhanced by carotenoid supplementation

Avian eggshell color is remarkably variable among and within species and its possible function has long been controversial. Female birds use biliverdin pigment to color their eggs blue and green. Although evidence is accumulating that blue-green eggshell coloration is costly to produce, the exact mechanisms underlying its expression are little studied. Biliverdin pigment is involved in important maintenance functions such as immune and antioxidant defenses and shows similar properties to carotenoid pigments. Carotenoids play a role as immunoenhancers and have the potential to ameliorate the impact of oxidative processes, although their antioxidant function could be minor for some bird species. Important life-history components can be limited by carotenoid availability, including sexual displays and fecundity. Here we explored if biliverdin-based eggshell pigmentation was affected by carotenoid availability in a seabird, by performing a carotenoid supplementation experiment in female blue-footed boobies (Sula nebouxii) after laying their first egg. In this species, blue eggshell color is associated with incubation patterns, and carotenoid availability affects the crucial trade-off between female foot ornamentation and fecundity. We found that under natural conditions, there was a decline in eggshell color with laying order, suggesting pigment limitation for females. However, carotenoid-supplemented females had enhanced second egg coloration compared to controls, and the color increase was independent of their previous pigment allocation to the first egg. Our results suggest that biliverdin-based eggshell coloration is costly to produce and can be alleviated by current carotenoid availability.     

Gene expression signatures in PCB-exposed Slovak children in relation to their environmental exposures and socio-physical characteristics

Environmental Science and Pollution Research - Our previous gene expression studies in a PCB-exposed cohort of young children in Slovakia revealed that early-life exposures to PCBs and other...     

Pyrolysis of plastic packaging waste: A comparison of plastic residuals from material recovery facilities with simulated plastic waste

Pyrolysis may be an alternative for the reclamation of rejected streams of waste from sorting plants where packing and packaging plastic waste is separated and classified. These rejected streams consist of many different materials (e.g., polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), aluminum, tetra-brik, and film) for which an attempt at complete separation is not technically possible or economically viable, and they are typically sent to landfills or incinerators. For this study, a simulated plastic mixture and a real waste sample from a sorting plant were pyrolyzed using a non-stirred semi-batch reactor. Red mud, a byproduct of the aluminum industry, was used as a catalyst. Despite the fact that the samples had a similar volume of material, there were noteworthy differences in the pyrolysis yields. The real waste sample resulted, after pyrolysis, in higher gas and solid yields and consequently produced less liquid. There were also significant differences noted in the compositions of the compared pyrolysis products.     

Maternal investment in eggs is affected by male feet colour and breeding conditions in the blue-footed booby, <Emphasis Type="Italic">Sula nebouxii</Emphasis>

Females are expected to vary investment in offspring according to variables that may influence the offspring fitness in a way that optimises her inclusive fitness for a particular context. Thus, when sexual ornaments signal the quality of the male, females might invest in reproduction as a function of the attractiveness of their mate. We tested whether breeding conditions and male feet colour influence reproductive decisions of blue-footed booby females. In the blue-footed booby, male feet colour is a dynamic condition-dependent sexually selected trait that is related to paternal effort. During two consecutive years, an El Niño year (poor breeding conditions) and a year with good breeding conditions, we experimentally reduced male attractiveness by modifying their feet colour after the first egg was laid and recorded female investment in the second egg. We found that, relative to the first egg in the clutch, females laid heavier second eggs during the poor year than during the good year. Females paired with males with duller feet colour reduced second-egg mass and volume and delayed the laying of the second egg, independently of the year. Absolute yolk androstenedione (A4) concentration (but not testosterone, T) in second eggs was higher during a poor year than during a good year. Only during a year with poor breeding conditions, females paired with experimental males decreased the relative A4 concentration (but not T) in the second egg compared to control females. Thus, blue-footed booby females probably favour brood reduction by decreasing egg quality and increasing size asymmetry between chicks when the breeding and the mate conditions are poor.     

Air pollution inhalation during acute exercise is dependent of the body mass index and ventilation of young men

Environmental Science and Pollution Research - Obesity and physical inactivity threaten human health, and both could be solved with exercise. However, a higher amount of pollutants is inhaled...     

Organochlorine compounds in soils and sediments of the mountain Andean Lakes

Semi-volatile organochlorine compounds (OC) were analyzed in remote Andean soils and lake sediments. The sampling sites covered a wide latitudinal gradient from 18 degrees S to 46 degrees S along Chile and an altitudinal gradient (10-4500 m). The concentrations were in the order of background levels, involving absence of major pollution sources in the high mountain areas. Significant correlations were found between log-transformed concentrations of hexachlorobenzene, alpha- and gamma-hexachlorocyclohexane in soils and total organic content (TOC). In addition, TOC-normalized concentrations of the most volatile OC showed a significant linear dependence with air temperature. This good agreement points to temperature as a significant factor for the retention of long range transported OC in remote ecosystems such as the Andean mountains, although other variables should not be totally excluded. The highest concentrations of OCs were achieved in the sites located at highest altitude and lowest temperature of the dataset.     

Carbonyls in the metropolitan area of Mexico City: calculation of the total photolytic rate constants Kp(s(-1)) and photolytic lifetime (tau) of ambient formaldehyde and acetaldehyde

A great number of studies on the ambient levels of formaldehyde and other carbonyls in the urban rural and maritime atmospheres have been published because of their chemical and toxicological characteristics, and adverse health effects. Due to their toxicological effects, it was considered necessary to measure these compounds at different sites in the metropolitan area of Mexico City, and to calculate the total rate of photolytic constants and the photolytic lifetime of formaldehyde and acetaldehyde. Four sites were chosen. Sampling was carried out at different seasons and atmospheric conditions. The results indicated that formaldehyde was the most abundant carbonyl, followed by acetone and acetaldehyde. Data sets obtained from the 4 sites were chosen to calculate the total rate of photolysis and the photolytic lifetime for formaldehyde and acetaldehyde. Maximum photolytic rate values were obtained at the maximum actinic fluxes, as was to be expected.