150 research outputs found
The roles of nutrients and herbivory in controlling the microbioerosion of tropical reefs
Coral reefs worldwide are suffering degradation from increasing fishing pressure, pollution, diseases, and coral bleaching. One important ecological consequence of such degradation is an increase in biological erosion, or bioerosion, of the coral framework by boring and grazing organisms. Therefore, it has become essential to understand the factors that control the processes and agents of bioerosion. The aim of my dissertation is to understand how organic and inorganic nutrients and herbivory affect the bioerosion of carbonate substrates by microbial endolithic organisms (bacteria, fungi and algae), an often overlooked component of bioerosion processes in coral reefs. Results of controlled experiments using herbivore-exclusion cages and fertilizers at Glovers Reef, Belize consistently showed significant effect of nutrients in stimulating microbial endoliths' substrate colonization and bioerosion rates of Strombus gigas shells. The addition of inorganic nutrients increased bioerosion rates by a factor of 8 to 15 in comparison to control treatments. Changes in nutrient ratios changed microbial endolithic community structure. The addition of nitrogen alone or in combination with phosphorus stimulated green algae, the addition of phosphorus alone stimulated cyanobacteria, and the addition of organic matter alone stimulated fungi. The inclusion of herbivores reduced observed bioerosion rates by half, demonstrating the importance of herbivory in modifying bioerosion processes. Field experiments on the relationship between water quality and the amount of microbioerosion in Lambis chiragra shells in nine coral reefs in East Africa demonstrated that other factors within reefs may interact with nutrients in determining bioerosion rates. Results suggested that epilithic algal cover, particularly crustose coralline algae, may decrease microborer colonization and bioerosion rates by reducing light conditions within substrates, so that no direct effects of nutrients on bioerosion rates are detected. A critical review of the evidence for nutrients as a primary control of bioerosion by different bioeroder groups (microborers, macroborers, and grazers) suggests that macroborer abundances reflect increases in nutrient conditions and may therefore represent a useful indicator of eutrophication and coral reef "health". This dissertation contributes to a better understanding of the factors affecting bioerosion by microbial endolithic organisms, which are important but often overlooked agents of bioerosion in coral reefs
Zoantharians (Hexacorallia: Zoantharia) Associated with Cold-Water Corals in the Azores Region: New Species and Associations in the Deep Sea
Zoantharians are a group of cnidarians that are often found in association with marine invertebrates, including corals, in shallow and deep-sea environments. However, little is known about deep-sea zoantharian taxonomy, specificity and nature of their associations with their coral hosts. In this study, analyses of molecular data (mtDNA COI, 16S, and 12S rDNA) coupled with ecological and morphological characteristics were used to examine zoantharian specimens associated with cold-water corals (CWC) at depths between 110 and 800 m from seamounts and island slopes in the Azores region. The zoantharians examined were found living in association with stylasterids, antipatharians and octocorals. From the collected specimens, four new species were identified: (1) Epizoanthus martinsae sp. n. associated with the antipatharian Leiopathes sp.; (2) Parazoanthus aliceae sp. n. associated with the stylasterid Errina dabneyi (Pourtalès, 1871); (3) Zibrowius alberti sp. n. associated with octocorals of the family Primnoidae [Paracalyptrophora josephinae (Lindström, 1877)] and the family Plexauridae (Dentomuricea aff. meteor Grasshoff, 1977); (4) Hurlizoanthus hirondelleae sp. n. associated with the primnoid octocoral Candidella imbricata (Johnson, 1862). In addition, based on newly collected material, morphological and molecular data and phylogenic reconstruction, the zoantharian Isozoanthus primnoidus Carreiro-Silva, Braga-Henriques, Sampaio, de Matos, Porteiro & Ocaña, 2011, associated with the primnoid octocoral Callogorgia verticillata (Pallas, 1766), was reclassified as Zibrowius primnoidus comb. nov. The zoantharians, Z. primnoidus comb. nov., Z. alberti sp. n., and H. hirondelleae sp. n. associated with octocorals showed evidence of a parasitic relationship, where the zoantharian progressively eliminates gorgonian tissue and uses the gorgonian axis for structure and support, and coral sclerites for protection. In contrast, the zoantharian P. aliceae sp. n. associated with the stylasterid E. dabneyi and the zoantharian E. martinsae sp. n. associated with the antipatharian Leiopathes sp., appear to use the coral host only as support with no visible damage to the host. The monophyly of octocoral-associated zoantharians suggests that substrate specificity is tightly linked to the evolution of zoantharians.Zibrowius alberti sp. n. urn:lsid:zoobank.org:act:8E186AD4-CA6E-419B-B46A-4C8D11C757DDHurlizoanthus hirondelleae sp. n. urn:lsid:zoobank.org:act:6737B10E-9E87-4BA0-9559-C22D49863732Parazoanthus aliceae sp.n. urn:lsid:zoobank.org:act:3D3AA61D-E5CC-47DF-94F1-A4A2FF59ABEAEpizoanthus martinsae sp. n. urn:lsid: zoobank.org:act:04686BB5-03D7-4132-B52B-CC89DF8EBFA8urn:lsid:zoobank.org:pub:FED88229-30F9-481F-9155-FF481790AE5
A road map for defining Good Environmental Status in the deep-sea
The development of tools to assess the Good Environmental Status (GES) in the Deep Sea (DS) is one of the aspects that ATLAS WP3 is addressing. GES assessment in the DS is challenging due to 1) the lack of baseline data, 2) the remoteness of the DS ecosystems, and 3) the limitations of the sampling methods currently available. Throughout the duration of the project, ATLAS will develop a suitable approach to address GES in the DS. During the 2nd General Assembly, we will present a draft for a “road map” to address GES in the DS as well some of the aspects discussed during the 2017 ICES WG on Deep Sea Ecosystems. The temporal and spatial scale at which GES should be assessed in the deep-sea is an important aspect to be considered. Due to the data limited situation and challenges posed to monitoring, it may well be the case that GES will have to be assessed at large spatial and temporal scales when comparing the shallower waters of the European Seas. For similar reasons, the type of indicators to be used may have to be simplified and likely be based on high-level analyses related to traits, pressures/risks, and habitat /ecosystem resilience. Ultimately, the results of the combined analyses of GES descriptors might bring to a potential refining or redefinition of the GES concept for the deep-sea
Zoantharians (Hexacorallia: Zoantharia) associated with cold-water corals in the azores region: New species and associations in the deep sea
Zoantharians are a group of cnidarians that are often found in association with marine invertebrates, including corals, in shallow and deep-sea environments. However, little is known about deep-sea zoantharian taxonomy, specificity and nature of their associations with their coral hosts. In this study, analyses of molecular data (mtDNA COI, 16S, and 12S rDNA) coupled with ecological and morphological characteristics were used to examine zoantharian specimens associated with cold-water corals (CWC) at depths between 110 and 800 m from seamounts and island slopes in the Azores region. The zoantharians examined were found living in association with stylasterids, antipatharians and octocorals. From the collected specimens, four new species were identified: (1) Epizoanthus martinsae sp. n. associated with the antipatharian Leiopathes sp.; (2) Parazoanthus aliceae sp. n. associated with the stylasterid Errina dabneyi (Pourtalès, 1871); (3) Zibrowius alberti sp. n. associated with octocorals of the family Primnoidae [Paracalyptrophora josephinae (Lindström, 1877)] and the family Plexauridae (Dentomuricea aff. meteor Grasshoff, 1977); (4) Hurlizoanthus hirondelleae sp. n. associated with the primnoid octocoral Candidella imbricata (Johnson, 1862). In addition, based on newly collected material, morphological and molecular data and phylogenic reconstruction, the zoantharian Isozoanthus primnoidus Carreiro-Silva, Braga-Henriques, Sampaio, de Matos, Porteiro & Ocaña, 2011, associated with the primnoid octocoral Callogorgia verticillata (Pallas, 1766), was reclassified as Zibrowius primnoidus comb. nov. The zoantharians, Z. primnoidus comb. nov., Z. alberti sp. n., and H. hirondelleae sp. n. associated with octocorals showed evidence of a parasitic relationship, where the zoantharian progressively eliminates gorgonian tissue and uses the gorgonian axis for structure and support, and coral sclerites for protection. In contrast, the zoantharian P. aliceae sp. n. associated with the stylasterid E. dabneyi and the zoantharian E. martinsae sp. n. associated with the antipatharian Leiopathes sp., appear to use the coral host only as support with no visible damage to the host. The monophyly of octocoral-associated zoantharians suggests that substrate specificity is tightly linked to the evolution of zoantharians.publishedVersio
Zinc uptake in fish intestinal epithelial model RTgutGC: Impact of media ion composition and methionine chelation
Apical uptake of zinc as ionic Zn(II) or as Zn-methionine (Zn-Met) was studied in RTgutGC cell line in vitro under media compositions mirroring the gut luminal ionic concentration of freshwater (FW) and seawater (SW) acclimated salmonids. Viability of the RTgutGC cells exposed to experimental media preparations showed a time-dependent decrease in SW treated cells, with the effect being significant at 48 h (P < 0.01), but not at 12 h or 24 h. Half effective concentration of Zn exposure over 12 h (EC50, in μM) was not differentially affected by media composition (FW, 59.7 ± 12.1 or SW, 83.2 ± 7.2; mean ± SE, P = 0.43). Zinc (65Zn) influx in RTgutGC was not different between FW or SW treated cells, but increased significantly in the presence of methionine (2 mM, L-Met or DL-Met). An interaction effect was observed between Zn concentration and media ionic composition on the impact of Met on apical Zn uptake (L-met, P < 0.001; DL-met, P = 0.02). In the presence of Met, apical Zn uptake in SW medium was significantly lower compared to FW, but only at higher Zn concentrations (12 and 25 μM, P < 0.01). Further, Met facilitated Zn uptake was reduced in cells treated with an amino acid transport system blocker with the effect being more significant and stereospecific in SW ionic conditions. The findings of this study showed that (i) Zn speciation in the presence of Met improved apical Zn uptake in RTgutGC cells and Zn-Met species were possibly taken up through Met uptake system. (ii) The effect was differentially affected by the ionic composition of the medium. Implications and limitations of the observations towards practical Zn nutrition of salmonids are discussed.publishedVersio
Prevalence of burnout syndrome among physicians of a federal education hospital
Objective: to estimate the prevalence of burnout syndrome among physicians of a federal education hospital in the state of Paraiba/Brazil. Method: a descriptive and observational study, which involved 134 doctors randomly chosen among medical residents, professors of the ufpb and federal physicians from the institution. three sets of questionnaires were used: socio-demographic and professional, mbi-hss and itra. the data were statistically analyzed with the aid of the spss-18.0. Results: it was detected a prevalence of the syndrome of 81,34% and the predominant features among respondents suffering from burnout were: young adult, with children, unmarried, early career working in various health institutions, with delicate relationship with supervisors in various activities and tasks with poorly defined. Conclusions: it was concluded that the burnout syndrome was highly prevalent in the workplace hospital doctor and should be target of public policies to reduce stress from this kind of work
Prevalence of burnout syndrome among nurses in urgency and emergency hospital system
Objective: investigating the prevalence of Burnout among nurses in hospitals of urgency and emergency in the State of Paraiba. Method: this is a descriptive, quantitative, cross-sectional study conducted in six hospitals specialized in urgency and emergency service in the state. The sample consisted of 110 nurses. It was used as instrument the Maslach Burnout Inventory. Data were analyzed with SPSS-Statistical Package for the Social Sciences version 18.0. Results: the results pointed to 65,3% of young people (20-30 years), 54,5% in situations of multiple employment, 49,1% with weekly working hours of 20-44 hours, 82,7% with prevalence of Burnout, being 59,1% in moderate level and 23,6% in severe level. Conclusion: it is concluded that the nurses showed significant levels of illness due to diuturnal contact with work stressors elements
Peeping through the deep: Insights to the reproductive strategies of cold water gorgonians in the Azores Archipelago
INTRODUCTION:The mean age at delivery has increased over the latest half of a century. Women of advanced maternal age have increased obstetrical risks and increased risk of chromosomal abnormalities and some other specified diagnoses in the offspring. The aim of this study was to assess the association between maternal age and overall child morbidity according to main diagnosis groups. MATERIAL AND METHODS:We conducted a national cohort study including 352 027 live firstborn singleton children. The children were born between Jan 1994 and Dec 2009 and followed to Dec 2012. Children were divided into groups according to maternal age: 15-24, 25-29, 30-34, and 35+ years. Poisson regression analyses calculated adjusted incidence rate ratios (IRR) of child morbidities according to main diagnoses groups A-Q of the International Classification of Disease 10 with adjustment for year of birth, body mass index, smoking, and mother's level of education. RESULTS:Average follow-up time was 11 years. Compared to children born to women 25-29 years, firstborn children to mothers aged 35+ had higher child morbidity in 8 of 19 main diagnosis groups and firstborn children to mothers 15-24 years had higher child morbidity in 12 of 19 main diagnosis groups. Thus, for a majority of diseases a U-shaped correlation was found, with lowest rates in women 25-29 years. CONCLUSION:Firstborn children to both older and younger mothers have higher overall morbidity as compared to children born by mothers 25-29 years
Benthic O-2 uptake by coral gardens at the Condor seamount (Azores)
Using the non-invasive aquatic eddy covariance technique, we provide the first oxygen (O-2) uptake rates from within coral gardens at the Condor seamount (Azores). To explore some of the key drivers of the benthic O-2 demand, we obtained benthic images, quantified local hydrodynamics, and estimated phototrophic biomass and deposition dynamics with a long-term moored sediment trap. The coral gardens were dominated by the octocorals Viminella flagellum and Dentomuricea aff. meteor. Daily rates of O-2 uptake within 3 targeted coral garden sites (203 to 206 m depth) ranged from 10.0 t 0.88 to 18.8 +/- 2.0 mmol m(-2) d(-1) (mean +/- SE) and were up to 10 times higher than 2 local sandy reference sites within the seamount summit area. The overall mean O-2 uptake rate for the garden (13.4 mmol m(-2) d(-1)) was twice the global mean for sedimentary habitats at comparable depths. Combined with parallel ex situ incubations, the results suggest that the octocorals might contribute just -similar to 5% of the observed O-2 uptake rates. Deposition of particulate organic matter (POM) assessed by the sediment trap accounted for less than 10% of the O-2 demand of the coral garden, implying a substantial POM supply circumventing the deployed traps. Our results expand the database for carbon turnover rates in cold-water coral habitats by including the first estimates from these largely understudied coral gardens.Peer reviewe
Local-scale feedbacks influencing cold-water coral growth and subsequent reef formation
Despite cold-water coral (CWC) reefs being considered biodiversity hotspots, very little is known about the main processes driving their morphological development. Indeed, there is a considerable knowledge gap in quantitative experimental studies that help understand the interaction between reef morphology, near-bed hydrodynamics, coral growth, and (food) particle transport processes. In the present study, we performed a 2-month long flume experiment in which living coral nubbins were placed on a reef patch to determine the effect of a unidirectional flow on the growth and physiological condition of Lophelia pertusa. Measurements revealed how the presence of coral framework increased current speed and turbulence above the frontal part of the reef patch, while conditions immediately behind it were characterised by an almost stagnant flow and reduced turbulence. Owing to the higher current speeds that likely promoted a higher food encounter rate and intake of ions involved in the calcification process, the coral nubbins located on the upstream part of the reef presented a significantly enhanced average growth and a lower expression of stress-related enzymes than the downstream ones. Yet, further experiments would be needed to fully quantify how the variations in water hydrodynamics modify particle encounter and ion intake rates by coral nubbins located in different parts of a reef, and how such discrepancies may ultimately affect coral growth. Nonetheless, the results acquired here denote that a reef influenced by a unidirectional water flow would grow into the current: a pattern of reef development that coincides with that of actual coral reefs located in similar water flow settings. Ultimately, the results of this study suggest that at the local scale coral reef morphology has a direct effect on coral growth thus, indicating that the spatial patterns of living CWC colonies in reef patches are the result of spatial self-organisation
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