Brood neglect and contingent foraging behavior in a pelagic seabird

Among species where there is a risk to leaving offspring unattended, parents usually take alternating shifts guarding their young. However, they may occasionally exhibit brood neglect by leaving their offspring unattended at the nest. To investigate this phenomenon further, we examined the foraging behavior of the northern gannet (Morus bassanus) during chick-rearing. This species has a prolonged nestling period (13 weeks) and the single chick is usually guarded by one or other of its parents, because unattended chicks are frequently attacked by conspecifics. We tested the prediction that the foraging behavior of adults when they left their offspring alone at the nest (unattended trips) would differ in character to when adults left offspring with their partner (attended trips). Brood neglect typically occurred after a longer-than-average attendance period at the nest. Unattended trips were, on average, about half the duration of attended trips, and therefore much closer to the colony. There was also a difference in departure direction between attended and unattended trips, with unattended trips tending to be northeast of the colony. Chicks were fed by parents after both attended and unattended trips, but the frequency and the duration of unattended trips increased as chicks grew older whereas the duration of attended trips decreased as chicks grew. These results indicate that parents may be making a trade-off between risk of attack to their offspring and food-intake rate, and that the solution to this trade-off is dependent on chick age.Communicated by C. Brown     

Long-Term Biomonitoring with Lichens: Comparing Data from Different Sampling Procedures

The results of 2 biomonitoring surveys carried out over a span of 7 years (1996–2003) in the Province of Ancona (central Italy) using the diversity of epiphytic lichens are reported. According to a recent standardisation process, in 2003 a different protocol was adopted, raising the problem of data comparability with the previous study. For this reason, a ‘pilot study' was carried out in which the two sampling tactics were both used. The high correlation between biodiversity values proved by the results of this study, let to compare the two lichen diversity data set and to identify the impacts on lichen communities of temporal variations of atmospheric quality in the study area, showing a reduction of stations classified as ‘altered' and an increase in stations classified as ‘semi-altered'. Furthermore, possible reduction of the sampling effort was detected performing a study on the sampling density of the survey area, indicating in a 6 × 6 km grid the best density to adopt in order to save financial resources for the future.     

Perceptions of disorder: Contributions of neighborhood characteristics to subjective perceptions of disorder

Theoretical explanations and empirical evidence of how disorder is perceived and its relation to independently observed measures of disorder are rare. In recent work, Sampson and Raudenbush [2004. Seeing disorder: Neighborhood stigma and the social construction of “Broken Windows”. Social Psychology Quarterly, 67(4), 319–342] investigated how individuals form perceptions of disorder and found that perceptions of disorder in Chicago neighborhoods are shaped not only by observable conditions of disorder, but also by neighborhoods’ racial and socioeconomic composition. In this paper, we investigate the bases for perceiving disorder with data from Baltimore using a methodology similar to that used by Sampson and Raudenbush (2004). Using surveys, systematic social observations, census data, and police records to investigate variations in individual perceptions of disorder at the individual and neighborhood levels, this study, consistent with the literature, finds that visual cues of disorder are not unambiguous and that perceptions of disorder are based not only on neighborhood observed disorder but also on individual characteristics of residents and neighborhood social structure. Additionally, our findings indicate that neighborhood poverty and not neighborhood racial composition affects perceptions of disorder in Baltimore. The fact that these findings are in contrast to the findings in Chicago suggests that the influence of racial segregation on perception of disorder is imbedded in the larger historical context.     

Conceptual PHES-system models of the Aysén watershed and fjord (Southern Chile): testing a brainstorming strategy

The use of brainstorming techniques for the generation of conceptual models, as the basis for the integrated management of physical-ecological-social systems (PHES-systems) is tested and discussed. The methodology is applied in the analysis of the Aysén fjord and watershed (Southern Chilean Coast). Results show that the proposed methods can be adequately used in management scenarios characterized by highly hierarchical, experts/non-experts membership.     

Occurrence of PCBs, PCDD/Fs, PBDEs and DDTs in Spanish breast milk: enantiomeric fraction of chiral PCBs

Concentrations and congener specific profile of DDTs, PCBs and PCDD/Fs have been determined in a number of Spanish breast milk samples. The concentrations found indicate a decreasing tendency compared to previous data from the 1990s. Mean concentrations of 238 ng/g fat weight, 111 ng/g fat weight and 82.1 pg/g fat weight were found for DDTs, PCBs and 2,3,7,8-PCDD/Fs, respectively. When the WHO-TEQs were calculated, PCDD/Fs was the family contributing with the highest percentage to the total (62-84%), followed by the non-ortho PCBs (10-25%) and the mono-ortho PCBs (5-24%). The congener specific accumulation patterns found were comparable to those reported in other studies in industrialised countries. In addition, the levels of 9 PBDEs congeners have been also determined in the breast milk samples. The concentrations ranged from 0.04 to 1.38 ng/g fat weight. The enantiomeric enrichment of a number of chiral PCBs in the breast milk samples, including congeners 84, 91, 95, 132, 135, 149, 171, 174, 176 and 183, has also been studied, for some of them for the first time in this matrix.     

Continuous carbon dioxide measurements in a rural area in the upper Spanish plateau

Continuous carbon dioxide (CO2) measurements over the period 2004-2005 for a rural area in the upper Spanish plateau were examined to characterize the influence of sources and sinks. The diurnal pattern and the annual cycle are presented. The baseline CO2 levels over the time frames researched are determined so as to achieve a more accurate verification of the ambient conditions when uptake is deployed at the site. The results reveal a mean concentration of 384.2 ppm, with 9.8-ppm variability. The mean maximum concentration levels at night, 4:00 a.m. Greenwich Mean Time (GMT), are 390.7 ppm, mainly when atmospheric stability increased. Moreover, mean CO2 levels increase in spring, peaking in May at 388.5 ppm. Concentrations then decline in summer and again increase in autumn, reaching a similar mean value in December. The results also show consistency with vegetation and crop growth, as well as the influence of meteorological conditions, soil features, and human activity in the area. Minimum and maximum CO2 concentrations present a similar but opposite variation, 4.4 ppm x yr(-1), with values decreasing in the latter. Diurnal variation is more pronounced during the growing season and higher in 2004, partly because of abundant rainfall. The lower daily amplitudes in the remaining months are attributed to the reduction in plant and soil respiration processes. The influence of wind on CO2 concentrations has enabled us to identify the contribution of emissions from the cities of Valladolid and Palencia. An increase in mean CO2 concentrations was observed in the, east-southeast, southeast, south-southeast, and south sectors for the former city, and north and east for the latter. The ratio of CO2 increase in the wind sectors influenced by these sources yielded a factor of 1.2 with respect to the relationship between the populations of the two cities.     

A new environmentally friendly process for the recovery of gold from electronic waste

A new method for the recovery of precious metals, in particular gold, from electronic waste is proposed. This work focused on the research of an easily renewable etching agent, in order to make an environmentally friendly process possible. Two well known hydrometallurgical etching agents, FeCl₃ and CuCl₂, were evaluated in terms of efficiency and kinetics, testing solutions with different concentration of etchant and hydrochloric acid. The recovery of spent etching solutions was evaluated: promising results were found in the case of CuCl₂, which can be completely restored by oxidation of the cuprous chloride formed during the etching using atmospheric oxygen.     

Detection of presumed genes encoding beta-lactamases by sequence based screening of metagenomes derived from Antarctic microbial mats

• Beta-lactamase genes were found in all samples from distant places in Antarctica. • Class C beta-lactamase coding genes were the most frequently found. • Diversity of sequences exceeds that of the beta-lactamases from clinical environment. Analysis of environmental samples for bacterial antibiotic resistance genes may have different objectives and analysis strategies. In some cases, the purpose was to study diversity and evolution of genes that could be grouped within a mechanism of antibiotic resistance. Different protocols have been designed for detection and confirmation that a functional gene was found. In this study, we present a sequence-based screening of candidate genes encoding beta-lactamases in 14 metagenomes of Antarctic microbial mats. The samples were obtained from different sites, representing diverse biogeographic regions of maritime and continental Antarctica. A protocol was designed based on generation of Hidden Markov Models from the four beta-lactamase classes by Ambler classification, using sequences from the Comprehensive Antibiotic Resistance Database (CARD). The models were used as queries for metagenome analysis and recovered contigs were subsequently annotated using RAST. According to our analysis, 14 metagenomes analyzed contain A, B and C beta-lactamase genes. Class D genes, however, were identified in 11 metagenomes. The most abundant was class C (46.8%), followed by classes B (35.5%), A (14.2%) and D (3.5%). A considerable number of sequences formed clusters which included, in some cases, contigs from different metagenomes. These assemblies are clearly separated from reference clusters, previously identified using CARD beta-lactamase sequences. While bacterial antibiotic resistance is a major challenge of public health worldwide, our results suggest that environmental diversity of beta-lactamase genes is higher than that currently reported, although this should be complemented with gene function analysis.     

Physical and biological controls of algal blooms in the Río de la Plata

Coupled three-dimensional hydrodynamic and ecological numerical simulations were used to investigate the role of transport, stagnation zones and dispersion on inter-annual blooms of the diatom Aulacoseira sp. in the vicinity of the drinking water intakes of the Buenos Aires city (Argentina) in the upper Río de la Plata. Three different summer events were analyzed. First, a mild biomass bloom year (2006–2007), second, a high biomass bloom year (2007–2008) and third, a “normal” no bloom year (2009–2010). Simulated water height, water temperature, suspended solids and chlorophyll \(a\) concentrations patterns compared well with field data. Results revealed that the advection of phytoplankton cells via inflows to the Río de la Plata triggered Aulacoseira sp. blooms in the domain. In addition, excessive growth observed near the drinking water intakes, along the Argentinean margin, were associated with long retention times (stagnant region) and weak horizontal dispersion. Increased concentrations of suspended solids in the water column, in response to re-suspension events, did not prevent the blooms, however, were found to also play a key role in controlling the rate of phytoplankton growth. Finally, a non-dimensional parameter, R, that considers phytoplankton patch size, e-folding growth and dispersion time scales is shown to determine the potential bloom occurrences, as well as bloom intensity; R values higher than 5.7 suggest intense phytoplankton growth. For the mild biomass bloom year, \(R = 7.5\) , for the high biomass bloom year, \(R = 11\) and for the “normal” no bloom year \(R= 0.4\) .