Search

Copyright of Journal of Animal Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: To estimate the incidence of the need for a dental prosthesis during early adulthood and its association with socioeconomic and oral disorder trajectories. Methods: In 1982, in the city of Pelotas, all live births (n = 5914) and their mothers were assessed. A representative sample of this cohort study was examined for oral health conditions at 15, 24 and 31 years (Oral Health Study–OHS). The need for a dental prosthesis was assessed at 24 and 31 years of age, and variables of interest (gender, skin colour, socioeconomic status (SES), use of dental services, caries and periodontal disease) were collected from different waves of this cohort. Longitudinal association between outcome and variables of interest was assessed using multilevel mixed models. Results: A total of 539 individuals were assessed in 2013 (60.7% response rate). The need for a dental prosthesis was 28.9% at 24 years. (95% CI 24.9‐33.2) and 49.0% at 31 years (95% CI 44.7‐53.3). Risk of presenting with a need for a dental prosthesis was higher in users of public services. Downwardly mobile and lower SES trajectory groups presented a higher risk of the need for a dental prosthesis. High‐risk caries trajectory group showed a higher risk of presenting with the need for a dental prosthesis from 24 to 31 years. Conclusions: Our findings demonstrate that the need for dental prosthesis from 24 to 31 years old was determined by trajectories of exposure during the life cycle, reinforcing that tackling socioeconomic inequalities at any stage of life can have an effect on an individual's oral health. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Applied Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Incubation is an energetically costly parental task of breeding birds. Incubating parents respond to environmental variation and nest‐site features to adjust the balance between the time spent incubating (i.e. nest attentiveness) and foraging to supply their own needs. Non‐natural nesting substrates such as human buildings impose new environmental contexts that may affect time allocation of incubating birds but this topic remains little studied. Here, we tested whether nesting substrate type (buildings vs. trees) affects the temperature inside the incubation chamber (hereafter 'nest temperature') in the Pale‐breasted Thrush Turdus leucomelas, either during 'day' (with incubation recesses) or 'night' periods (representing uninterrupted female presence at the nest). We also tested whether nesting substrate type affects the incubation time budget using air temperature and the day of the incubation cycle as covariates. Nest temperature, when controlled for microhabitat temperature, was higher at night and in nests in buildings but did not differ between daytime and night for nests in buildings, indicating that buildings partially compensate for incubation recesses by females with regard to nest temperature stability. Females from nests placed in buildings exhibited lower nest attentiveness (the overall percentage of time spent incubating) and had longer bouts off the nest. Higher air temperatures were significantly correlated with shorter bouts on the nest and longer bouts off the nest, but without affecting nest attentiveness. We suggest that the longer bouts off the nest taken by females of nests in buildings is a consequence of higher nest temperatures promoted by man‐made structures around these nests. Use of buildings as nesting substrate may therefore increase parental fitness due to a relaxed incubation budget, and potentially drive the evolution of incubation behaviour in certain urban bird populations. [ABSTRACT FROM AUTHOR]

Objective: There are few studies evaluating the relationship between depression symptoms (DS) and physical activity (PA) considering peoples' sociodemographic characteristics. This study aimed to analyse the relationship between DS and PA, stratified by sociodemographic characteristics of European adults. Methods: Participants were 29,285 adults (13,943 men, 47.6%; 15,342 women, 52.4%), aged 50.9 ± 17.4 (50.6 ± 17.3 men, 51.1 ± 17.5 women) from the European Social Survey round 7. DS was assessed with the Centre for Epidemiological Studies Depression Scale (CES-D8). Leisure-time PA (LTPA) was self-reported. The analysed sociodemographic characteristics were sex, age, living place, household members, marital status, income, and educational level. The relationship between DS and PA, stratified by sociodemographic variables, was examined by linear regression models. Results: Engaging in LTPA was negatively and linearly related to DS, independently of being men or women, being younger, middle or older adult, living in an urban or rural area, having children or not, being single or married, being wealthy or poor, employment status, and to having a lower or a higher education level. Age was the variable with both the least and the greatest effect of LTPA on DS. The least effect of LTPA on DS was observed in younger adults (β = −0.08, 95% CI: −0.11, −0.05) and the greatest effect in retired people (β = −0.33, 95% CI: −0.36, −0.29). Conclusion: Independently of sociodemographic characteristics, LTPA is associated with DS and can benefit everyone. Public health policies for promoting mental health should include PA promotion as an important strategy for the prevention or treatment of DS. [ABSTRACT FROM AUTHOR]

The purpose of this research was to conduct a systematic review of published articles related to the effect of recreational football on non‐communicable diseases. A systematic review of Web of Science, SPORTDiscus, MEDLINE, and PubMed databases was performed according to PRISMA guidelines. Only empirical studies were included. There were no restrictions on the types of study design eligible for inclusion. The primary outcome measures result from the potential effects of recreational football on non‐communicable diseases (eg, blood pressure, bone density, LDL cholesterol, and fat mass). A total of 44 articles met the inclusion criteria and were included. Recreational football is shown to: (a) decrease blood pressure and resting heart rate, improve cardiac structure and functioning, as well as increase maximal oxygen uptake in both sexes; (b) reduce cholesterol and triglycerides levels, increase insulin sensitivity, and have a positive impact on glycemic control; (c) improve bone mineralization, increase both bone mineral density and content, as well as acting as a stimulus for osteogenesis; and (d) be clearly beneficial for bone health, while slightly beneficial for body composition, muscle strength, and maximal oxygen uptake in adults with prostate cancer. The present systematic review demonstrated the benefits of recreational football practice on non‐communicable diseases related to cardiovascular and bone health, body composition, type 2 diabetes, and prostate cancer. The effectiveness of recreational football on the aforementioned diseases may be related to age and gender; however, further research is required. [ABSTRACT FROM AUTHOR]

Dissolved organic matter (DOM) is the main substrate for aquatic prokaryotes, fuelling their metabolism and controlling community composition. Amazonian rivers transport and process large fluxes of terrestrial DOM, but little is known about the link between DOM composition and heterotrophic bacteria in the Amazon basin. The aims of this study were to characterize DOM composition and investigate the coupling between DOM and bacterial community composition (BCC) during a complete hydrological cycle in an Amazon floodplain system (lake Janauacá). Our study revealed a clear seasonal pattern in DOM composition through the flood pulse, which affected the amounts of autochthonous and allochthonous inputs and consequently the extent of humification, molecular weight, and aromaticity of the DOM. BCC was tightly coupled to DOM fluorescence, which was also driven by differences over the hydrological cycle, with distinct components and operational taxonomic units being simultaneously more abundant and correlating with a specific season. This coupling was particularly well reflected for three of the four identified fluorescence components, two terrestrial humic‐like components (C1 and C3) and an autochthonous component (C4). Despite clear changes in DOM composition, dissolved organic carbon concentrations tended to be relatively stable throughout the year. Overall, our results suggest that BCC shifts were associated with DOM quality but not with its quantity (that remains relatively constant throughout the year), and that bacteria preferably use labile and freshly produced DOM in lake Janauacá. [ABSTRACT FROM AUTHOR]

Phytoplankton time‐series enable the observation of recurrent seasonal patterns on community composition, but drastic shifts in community structure are rarely observed, unless linked to anthropogenic impacts (e.g. changes in nutrient inputs). Here, we report a unique case of non‐seasonal, multiannual regime shift of phytoplankton community structure in Lake Kivu, East Africa, and explore the possible causes for such changes.We recorded phytoplankton biomass every 2 weeks over a period of 12 years (from 2002 to 2015). Phytoplankton community previously dominated by cyanobacteria and diatoms changed considerably from 2012, with a conspicuous rise in the biomass of green algae (from 3 to 33% lake‐wide), and a decline of cryptophytes and cyanobacteria along with an increase in total chlorophyll a concentration. Concomitantly, we observed significant differences in the mixed layer depth between the two periods, resulting from changes in the thermal gradient. The euphotic zone depth was also reduced in 2012–2015, probably from the higher phytoplankton biomass. Moreover, mean particulate nitrogen and phosphorus increased as well as the particulate N:P ratio.Desmids (Cosmarium laeve) now dominate the mixolimnion, probably due to atelomixis, observed in high‐frequency temperature measurements. We believe that decadal or multidecadal variability of climate on the Indian Ocean may be the reason for this regime shift in thermal stratification, with a strong impact in phytoplankton community structure.In conclusion, our study demonstrates that tropical lakes may be subject to non‐seasonal fluctuations that generate multiannual regime shifts. These regime shifts have probably never been reported previously because of the lack of long phytoplankton time‐series in low latitudes. [ABSTRACT FROM AUTHOR]

Understanding spatial and temporal dynamics of microbial communities is a central challenge in microbial ecology since microorganisms play a key role in ecosystem functioning and biogeochemical cycles. Amazonian aquatic systems comprise a dynamic mosaic of heterogeneous habits but are understudied and there is limited information about the mechanisms that shape bacterial community composition (BCC).There is a consensus that environmental selection (species sorting) and dispersal processes (source–sink dynamics) act in concert to shape the composition of these communities, but the relative importance of each mechanism may vary dramatically through time and between systems.Applying 16S rRNA gene amplicon high‐throughput sequencing, we studied factors and processes that modulate BCC in an Amazonian floodplain lake and used source‐tracking models to trace the main dispersal sources of microorganisms in the whole floodplain system during a full hydrological cycle.Our source‐tracking models indicated that dispersal processes were predominant, explaining most of the BCC variability throughout the study period. We observed more sources contributing to the sink community during the falling water than rising water period, when contributions from the Solimões River dominated.There was a clear seasonal pattern in BCC, closely related to environmental variables, suggesting that the successful establishment of dispersing bacteria also depends on environmental filtering that is linked to water flow.In summary, source–sink dynamics and species sorting were strongly affected by water exchange and connectivity with the main river that varied throughout the flood pulse cycle. Our results demonstrated the influence of lateral transport and temporal dynamics on BCC in Amazonian floodplain lakes that could ultimately impact regional carbon budgets and biogeochemical cycles. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effect of storage time and temperature on the effectiveness of bleaching agents. Methods: Enamel slabs were randomly allocated according to the concentration of carbamide peroxide (CP): 10% (CP10) and 16% (CP16). Shade evaluations were conducted at baseline and then after 3 and 12 months of storage at 3 different temperatures: 10°C (±2°C), 25°C (±2°C), and 35°C (±2°C). Objective color evaluation was performed (spectrophotometer CIEL*a*b* system and CIEDE2000) to calculate the color change (ΔE00). Subjective evaluation was performed using the VITA classical shade guide followed by shade variation (ΔS). Results: The bleaching effect of different CP concentrations (10% and 16%) at baseline showed no differences with regard to objective (ΔE00) and subjective parameters (ΔS) (P > .05). No differences were observed between CP concentrations stored for the same length of time and at the same temperature for either parameter (P > .05). In terms of objective measurement (ΔE00), a reduction in the bleaching effect was shown for both CP concentrations (10% and 16%) when stored for 12 months at 35°C, and compared with the baseline (P < .05). As regards the subjective parameters (ΔS), after 12 months, both CP concentrations (10% and 16%) stored at 35°C showed a decrease in bleaching capacity compared to baseline (P < .05). CP10 and CP16 stored at 10°C and 25°C did not suffer any loss in bleaching ability, even after 12 months (P > .05). Conclusions: The storage of bleaching agents for long periods at high temperatures can reduce the bleaching effectiveness of CP at 10% and 16%. Clinical Significance: Clinicians must be made aware that they should store their bleaching products under proper temperature conditions and use them within an appropriate time frame; otherwise, the bleaching effect could be lost. [ABSTRACT FROM AUTHOR]

Catalysed reporter deposition-fluorescence in situ hybridization ( CARD-FISH) is a powerful approach to quantify bacterial taxa. In this study, we compare the performance of the widely used B acteroidetes CF319 a probe with the new CF968 probe. In silico analyses and tests with isolates demonstrate that CF319 a hybridizes with non- B acteroidetes sequences from the R hodobacteraceae and A lteromonadaceae families. We test the probes' accuracy in 37 globally distributed marine samples and over two consecutive years at the Blanes Bay Microbial Observatory ( NW Mediterranean). We also compared the CARD-FISH data with the B acteroidetes 16 S rRNA gene sequences retrieved from 27 marine metagenomes from the TARA Oceans expedition. We find no significant differences in abundances between both approaches, although CF319 a targeted some unspecific sequences and both probes displayed different abundances of specific B acteroidetes phylotypes. Our results demonstrate that quantitative estimations by using both probes are significantly different in certain oceanographic regions ( Mediterranean Sea, Red Sea and Arabian Sea) and that CF968 shows seasonality within marine B acteroidetes, notably large differences between summer and winter that is overlooked by CF319 a. We propose CF968 as an alternative to CF319 a for targeting the whole B acteroidetes phylum since it has better coverage, greater specificity and overall better quantifies marine B acteroidetes. [ABSTRACT FROM AUTHOR]

Sequencing of 16S rDNA polymerase chain reaction ( PCR) amplicons is the most common approach for investigating environmental prokaryotic diversity, despite the known biases introduced during PCR. Here we show that 16S rDNA fragments derived from Illumina-sequenced environmental metagenomes ( mitags) are a powerful alternative to 16S rDNA amplicons for investigating the taxonomic diversity and structure of prokaryotic communities. As part of the Tara Oceans global expedition, marine plankton was sampled in three locations, resulting in 29 subsamples for which metagenomes were produced by shotgun Illumina sequencing (ca. 700 Gb). For comparative analyses, a subset of samples was also selected for Roche-454 sequencing using both shotgun ( m454tags; 13 metagenomes, ca. 2.4 Gb) and 16S rDNA amplicon ( 454tags; ca. 0.075 Gb) approaches. Our results indicate that by overcoming PCR biases related to amplification and primer mismatch, mitags may provide more realistic estimates of community richness and evenness than amplicon 454tags. In addition, mitags can capture expected beta diversity patterns. Using mitags is now economically feasible given the dramatic reduction in high-throughput sequencing costs, having the advantage of retrieving simultaneously both taxonomic ( Bacteria, Archaea and Eukarya) and functional information from the same microbial community. [ABSTRACT FROM AUTHOR]

Despite representing only a small fraction of the ocean's dissolved organic matter pool, dissolved free amino acids (DFAA) have high turnover rates and are major nitrogen and carbon sources for bacterioplankton. Both phytoplankton and bacterioplankton assimilate and release DFAA, but their consumption and production are difficult to quantify in nature due to their short residence times (min) as dissolved monomers. We segregated DFAA production by phytoplankton and bacterial consumption by measuring individual DFAA concentrations in four axenic phytoplankton cultures during the exponential growth phase, and also after 4 d incubations in the presence of a natural bacterioplankton community. The amounts and composition of the DFAA pool varied widely among phytoplankton species. The proportion of dissolved organic carbon attributed to DFAA varied among cultures. The picoeukaryotic prasinophyte, Micromonas pusilla, released higher amounts of DFAA than the other species tested (diatoms and dinoflagellate), especially alanine, which has been reported as the dominant individual DFAA in some oligotrophic environments. Community structure of heterotrophic prokaryotes responded to differences in the quality of organic matter released among microalgal species, with Roseobacter-related bacteria responding strongly to exudate composition. Our results demonstrate the specificity of DFAA extracellular release among several algal species and their preferential uptake by members of bacterial communities. [ABSTRACT FROM AUTHOR]

Phytoplankton and heterotrophic prokaryotes are major components of the microbial food web and interact continuously: heterotrophic prokaryotes utilize the dissolved organic carbon derived from phytoplankton exudation or cell lysis (DOCp), and mineralization by heterotrophic prokaryotes provides inorganic nutrients for phytoplankton. For this reason, these communities are expected to be closely linked, although the study of the interactions between them is still a major challenge. Recent studies have presented interactions between phytoplankton and heterotrophic prokaryotes based on coexistence or covariation throughout a time-series. However, a real quantification of the carbon flow within these networks (defined as the interaction strength, IS) has not been achieved yet. This is critical to understand the selectivity degree of bacteria responding to specific algal DOCp. Here we used microautoradiography to quantify the preferences of the major heterotrophic prokaryote phylogenetic groups on DOC derived from several representative phytoplankton species, and expressed these preferences as an IS value. The distribution of the ISs was not random but rather skewed towards weak interactions, in a similar way as the distributions described for stable complex non-microbial ecosystems, indicating that there are some cases of high specificity on the use of specific algal DOCp by some bacterial groups, but weak interactions are more common and may be relevant as well. The variety of IS patterns observed supports the view that the vast range of different resources (different types of organic molecules) available in the sea selects and maintains the high levels of diversity described for marine bacterioplankton. [ABSTRACT FROM AUTHOR]

1. Abundance and bacterial production (BP) of heterotrophic bacteria (HBact) were measured in the north and south basins of Lake Tanganyika, East Africa, during seasonal sampling series between 2002 and 2007. The major objective of the study was to assess whether BP can supplement phytoplankton particulate primary production (particulate PP) in the pelagic waters, and whether BP and particulate PP are related in this large lake. HBact were enumerated in the 0–100 m surface layer by epifluorescence microscopy and flow cytometry; BP was quantified using 3H-thymidine incorporation, usually in three mixolimnion layers (0–40, 40–60 and 60–100 m). 2. Flow cytometry allowed three subpopulations to be distinguished: low nucleic acid content bacteria (LNA), high nucleic acid content bacteria (HNA) and Synechococcus-like picocyanobacteria (PCya). The proportion of HNA was on average 67% of total bacterial abundance, and tended to increase with depth. HBact abundance was between 1.2 × 105 and 4.8 × 106 cells mL−1, and was maximal in the 0–40 m layer (i.e. roughly, the euphotic layer). Using a single conversion factor of 15 fg C cell−1, estimated from biovolume measurements, average HBact biomass (integrated over a 100-m water column depth) was 1.89 ± 1.05 g C m−2. 3. Significant differences in BP appeared between seasons, especially in the south basin. The range of BP integrated over the 0–100 m layer was 93–735 mg C m−2 day−1, and overlapped with the range of particulate PP (150–1687 mg C m−2 day−1) measured in the same period of time at the same sites. 4. Depth-integrated BP was significantly correlated to particulate PP and chlorophyll- a, and BP in the euphotic layer was on average 25% of PP. 5. These results suggest that HBact contribute substantially to the particulate organic carbon available to consumers in Lake Tanganyika, and that BP may be sustained by phytoplankton-derived organic carbon in the pelagic waters. [ABSTRACT FROM AUTHOR]

1. We used flow cytometry to characterize freshwater photosynthetic picoplankton (PPP) and heterotrophic bacteria (HB) in Lake Kivu, one of the East-African great lakes. Throughout three cruises run in different seasons, covering the four major basins, phycoerythrin-rich cells dominated the PPP. Heterotrophic bacteria and PPP cell numbers were always high and spatial variations were modest. This represents an important difference from temperate and high latitude lakes that show high fluctuations in cell abundance over an annual cycle. 2. Three populations of picocyanobacteria were identified: one corresponded to single-cells (identified as Synechococcus by epifluorescence microscopy, molecular methods and pigment content), and the two other that most probably correspond to two and four celled colonies of the same taxon. The proportion of these two subpopulations was greater under stratified conditions, with stronger nutrient limitation. 3. High PPP concentrations ( c. 105 cell mL−1) relative to HB ( c. 106 cell mL−1) were always found. Lake Kivu supports relatively less bacteria than phytoplankton biomass than temperate systems, probably as a consequence of factors such as temperature, oligotrophy, nutrient limitation and trophic structure. 4. A review of PPP concentration across aquatic systems suggests that the abundance of Synechococcus-like cyanobacteria in large, oligotrophic, tropical lakes is very high. 5. Photosynthetic picoplankton cell abundances in the oligotrophic tropical lakes Kivu and Tanganyika are comparable to those of eutrophic temperate lakes. This apparently contradicts the view that PPP abundance increases with increasing eutrophy. More data on PPP in tropical lakes are needed to explore further this particular pattern. [ABSTRACT FROM AUTHOR]

1. This study focused on phytoplankton production in Lake Tanganyika. We provide new estimates of daily and annual primary production, as well as growth rates of phytoplankton, and we compare them with values published in former studies. 2. Chlorophyll- a (chl- a) in the mixed layer ranged from 5 to 120 mg chl- a m−2 and varied significantly between rainy and dry seasons. Particulate organic carbon concentrations were significantly higher in the south basin (with 196 and 166 mg C m−3 in the dry and the rainy season, respectively) than in the north basin (112 and 109 mg C m−3, respectively). 3. Carbon : phosphorus (C : P) ratios varied according to season. Phosphorus limitation seemed to occur more frequently than nitrogen limitation, especially during the rainy season. Severe P deficiencies were rare. 4. Measured particulate daily primary production ranged from 110 to 1410 mg C m−2 day−1; seasonal contrasts were well marked in the north basin, but less in the south basin, where primary production peaks occurred also in the rainy season. Estimates of annual primary production, based on daily primary production calculated from chl- a and water transparency, gave values lower than those reported in previous studies. Picophytoplankton accounted on average for 56% of total particulate production in the south basin during the wet season of 2003. 5. Phytoplankton growth rates, calculated from primary production, ranged from 0.055 to 0.282 day−1; these are lower than previously published values for Lake Tanganyika. [ABSTRACT FROM AUTHOR]

de Senerpont Domis et al. (2013, Freshwater Biology, 58, 463-482) forecasted changes in plankton dynamics in temperate, polar and tropical regions resulting from climate change. For tropical regions, they predicted an increase in precipitation intensity that would increase nutrient loading, increasing phytoplankton biomass and select for plankton adapted to flushing., We do not agree with these predictions, as regional projections from the IPCC did not forecast a major increase in precipitation in tropical regions. The only regions where a slight increase in precipitation was projected were eastern Africa and South- East Asia. In eastern Africa, the major freshwater bodies are large, deep lakes that have very long residence times and are unlikely to be affected by flushing. Moreover, nutrient inputs from their catchment represent a small fraction of their total nutrient loading., Several independent studies carried out in this region have provided evidence of a decrease in primary productivity in some of these large tropical lakes due to climate change. The major process providing nutrients to the euphotic layer is internal loading, which has been reduced as warming of the surface waters has increased the temperature gradient and the water column stability. Moreover, reduced velocity of trade winds during the dry season has affected the mixed layer depth and decreased internal nutrient fluxes. Therefore, the trend for large tropical lakes in a warming climate is oligotrophication, not eutrophication., In tropical South America, the rainfall increase is not the dominant scenario; thus, the predicted changes in plankton dynamics do not stand., Therefore, we believe that the predictions presented in the paper for tropical systems under a changing climate are invalid for most tropical systems. [ABSTRACT FROM AUTHOR]

A correction to the article "Production of Chromophoric Dissolved Organic Matter by Marine Phytoplankton," published in previous issue is presented.

Incubation experiments with axenic cultures of four common phytoplankton species of the genera Chaetoceros, Skeletonema, Prorocentrum, and Micromonas were performed to test for the production of fluorescent dissolved organic matter (FDOM) by marine phytoplankton. Our results prove that the four species exuded both fluorescent protein-like and marine humic-like materials in variable amounts, with more production by the diatoms Chaetoceros sp. and Skeletonema costatum and less by Prorocentrum minimum. Whereas the exudation of protein-like substances by healthy phytoplankton cells has been recognized, the in situ production of marine humic-like substances is still a matter of debate. Using axenic cultures, we demonstrate unequivocally that phytoplankton can directly contribute to the autochthonous production of colored humic-like substances in the ocean. Extrapolation of these findings to the field indicates that about 20% of the marine humic-like substances produced in the highly productive coastal upwelling system of the Ria de Vigo could originate from growing phytoplankton. Therefore, the exudation of FDOM by marine phytoplankton should be considered in future studies of the dynamics of colored DOM in marine systems. [ABSTRACT FROM AUTHOR]