167 research outputs found

    Ultraviolet radiation shapes seaweed communities

    Get PDF

    Reduced Diversity and High Sponge Abundance on a Sedimented Indo-Pacific Reef System: Implications for Future Changes in Environmental Quality

    Get PDF
    Although coral reef health across the globe is declining as a result of anthropogenic impacts, relatively little is known of how environmental variability influences reef organisms other than corals and fish. Sponges are an important component of coral reef fauna that perform many important functional roles and changes in their abundance and diversity as a result of environmental change has the potential to affect overall reef ecosystem functioning. In this study, we examined patterns of sponge biodiversity and abundance across a range of environments to assess the potential key drivers of differences in benthic community structure. We found that sponge assemblages were significantly different across the study sites, but were dominated by one species Lamellodysidea herbacea (42% of all sponges patches recorded) and that the differential rate of sediment deposition was the most important variable driving differences in abundance patterns. Lamellodysidea herbacea abundance was positively associated with sedimentation rates, while total sponge abundance excluding Lamellodysidea herbacea was negatively associated with rates of sedimentation. Overall variation in sponge assemblage composition was correlated with a number of variables although each variable explained only a small amount of the overall variation. Although sponge abundance remained similar across environments, diversity was negatively affected by sedimentation, with the most sedimented sites being dominated by a single sponge species. Our study shows how some sponge species are able to tolerate high levels of sediment and that any transition of coral reefs to more sedimented states may result in a shift to a low diversity sponge dominated system, which is likely to have subsequent effects on ecosystem functioning. © 2014 Powell et al

    Release of Metal Ions from Orthodontic Appliances: An In Vitro Study

    Get PDF
    In this paper, we report the results of an in vitro experiment on the release of metal ions from orthodontic appliances composed of alloys containing iron, chromium, nickel, silicon, and molybdenum into artificial saliva. The concentrations of magnesium, aluminum, silicon, phosphorus, sulfur, potassium, calcium, titanium, vanadium, manganese, iron, cobalt, copper, zinc, nickel, and chromium were significantly higher in artificial saliva in which metal brackets, bands, and wires used in orthodontics were incubated. In relation to the maximum acceptable concentrations of metal ions in drinking water and to recommended daily doses, two elements of concern were nickel (573 vs. 15 μg/l in the controls) and chromium (101 vs. 8 μg/l in the controls). Three ion release coefficients were defined: α, a dimensionless multiplication factor; β, the difference in concentrations (in micrograms per liter); and γ, the ion release coefficient (in percent). The elevated levels of metals in saliva are thought to occur by corrosion of the chemical elements in the alloys or welding materials. The concentrations of some groups of dissolved elements appear to be interrelated

    Rib fracture after stereotactic radiotherapy on follow-up thin-section computed tomography in 177 primary lung cancer patients

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Chest wall injury after stereotactic radiotherapy (SRT) for primary lung cancer has recently been reported. However, its detailed imaging findings are not clarified. So this study aimed to fully characterize the findings on computed tomography (CT), appearance time and frequency of chest wall injury after stereotactic radiotherapy (SRT) for primary lung cancer</p> <p>Materials and methods</p> <p>A total of 177 patients who had undergone SRT were prospectively evaluated for periodical follow-up thin-section CT with special attention to chest wall injury. The time at which CT findings of chest wall injury appeared was assessed. Related clinical symptoms were also evaluated.</p> <p>Results</p> <p>Rib fracture was identified on follow-up CT in 41 patients (23.2%). Rib fractures appeared at a mean of 21.2 months after the completion of SRT (range, 4 -58 months). Chest wall edema, thinning of the cortex and osteosclerosis were findings frequently associated with, and tending to precede rib fractures. No patients with rib fracture showed tumors > 16 mm from the adjacent chest wall. Chest wall pain was seen in 18 of 177 patients (10.2%), of whom 14 patients developed rib fracture. No patients complained of Grade 3 or more symptoms.</p> <p>Conclusion</p> <p>Rib fracture is frequently seen after SRT for lung cancer on CT, and is often associated with chest wall edema, thinning of the cortex and osteosclerosis. However, related chest wall pain is less frequent and is generally mild if present.</p

    Central odontogenic fibroma: a case report with long-term follow-up

    Get PDF
    An osteolytic tumour of the mandible with prominent expansive growth on the alveolar ridge and displacement of the involved teeth is described in a 28-year-old man. The lesion was diagnosed as a central odontogenic fibroma, an uncommon benign neoplasm derived from dental apparatus, and was removed by curettage. The patient remains asymptomatic after thirteen years of follow-up, which supports the claimed indolent behavior of this poorly documented disease and the adequacy of a conservative surgical treatment

    A more fine-grained measure towards animal welfare: a study with regards to gender differences in Spanish students

    Get PDF
    The environmental issue is nowadays taking more importance in the environmental awareness all around the world, and in this field, animal consideration is more and more spread. A highlighted part in globalisation is the animal welfare awareness. This article presents a study comparing attitudes towards animals among secondary and university students in reference to gender. It was carried out on 1394 Spanish participants from 11 to 26 years. The instrument used in the study is the reviewed version of the Animal Welfare Attitude Scale which was renamed as “Animal Welfare Attitude-Revised Scale” (AWA-R Scale), with a Cronbach a reliability value of 0.85. It is subdivided into four components namely C1: animal abuse for pleasure or due to ignorance; C2: leisure with animals; C3: farm animals; and C4: animal abandonment. These components have been deeply detailed by a confirmatory factor analysis (CFA), which highly contributes to define the position of participants for the different dimensions of animal welfare. It is concluded that significant differences exist between males’ and females’ attitudes in all components of the AWA-R Scale. It is also suggested that two social characteristics—people’s attitudes towards animals and towards environmental protection—are, at the very least, coexistent and may indeed be interdependent. These differences between gender in matters of socialisation could thus be reflected in environmental attitudes, and also in others related to them, i.e. animal welfare attitudes

    Tolerance of sponge assemblages to temperature anomalies: resilience and proliferation of sponges following the 1997-8 El-Niño southern oscillation.

    Get PDF
    Coral reefs across the world are under threat from a range of stressors, and while there has been considerable focus on the impacts of these stressors on corals, far less is known about their effect on other reef organisms. The 1997-8 El-Niño Southern Oscillation (ENSO) had notable and severe impacts on coral reefs worldwide, but not all reef organisms were negatively impacted by this large-scale event. Here we describe how the sponge fauna at Bahia, Brazil was influenced by the 1997-8 ENSO event. Sponge assemblages from three contrasting reef habitats (reef tops, walls and shallow banks) at four sites were assessed annually from 1995 to 2011. The within-habitat sponge diversity did not vary significantly across the study period; however, there was a significant increase in density in all habitats. Multivariate analyses revealed no significant difference in sponge assemblage composition (ANOSIM) between pre- and post-ENSO years for any of the habitats, suggesting that neither the 1997-8 nor any subsequent smaller ENSO events have had any measurable impact on the reef sponge assemblage. Importantly, this is in marked contrast to the results previously reported for a suite of other taxa (including corals, echinoderms, bryozoans, and ascidians), which all suffered mass mortalities as a result of the ENSO event. Our results suggest that of all reef taxa, sponges have the potential to be resilient to large-scale thermal stress events and we hypothesize that sponges might be less affected by projected increases in sea surface temperature compared to other major groups of reef organisms

    Cytocompatibility of Medical Biomaterials Containing Nickel by Osteoblasts: a Systematic Literature Review

    Get PDF
    The present review is based on a survey of 21 studies on the cytocompatibility of medical biomaterials containing nickel, as assessed by cell culture of human and animal osteoblasts or osteoblast-like cells. Among the biomaterials evaluated were stainless steel, NiTi alloys, pure Ni, Ti, and other pure metals. The materials were either commercially available, prepared by the authors, or implanted by various techniques to generate a protective layer of oxides, nitrides, acetylides. The observation that the layers significantly reduced the initial release of metal ions and increased cytocompatibility was confirmed in cell culture experiments. Physical and chemical characterization of the materials was performed. This included, e.g., surface characterization (roughness, wettability, corrosion behavior, quantity of released ions, microhardness, and characterization of passivation layer). Cytocompatibility tests of the materials were conducted in the cultures of human or animal osteoblasts and osteoblast-like cells. The following assays were carried out: cell proliferation and viability test, adhesion test, morphology (by fluorescent microscopy or SEM). Also phenotypic and genotypic markers were investigated. In the majority of works, it was found that the most cytocompatible materials were stainless steel and NiTi alloy. Pure Ni was rendered and less cytocompatible. All the papers confirmed that the consequence of the formation of protective layers was in significant increase of cytocompatibility of the materials. This indicates the possible further modifications of the manufacturing process (formation of the passivation layer)

    Environmental sensing and response genes in cnidaria : the chemical defensome in the sea anemone Nematostella vectensis

    Get PDF
    Author Posting. © The Author(s), 2008. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Cell Biology and Toxicology 24 (2008): 483-502, doi:10.1007/s10565-008-9107-5.The starlet sea anemone Nematostella vectensis has been recently established as a new model system for the study of the evolution of developmental processes, as cnidaria occupy a key evolutionary position at the base of the bilateria. Cnidaria play important roles in estuarine and reef communities, but are exposed to many environmental stressors. Here I describe the genetic components of a ‘chemical defensome’ in the genome of N. vectensis, and review cnidarian molecular toxicology. Gene families that defend against chemical stressors and the transcription factors that regulate these genes have been termed a ‘chemical defensome,’ and include the cytochromes P450 and other oxidases, various conjugating enyzymes, the ATP-dependent efflux transporters, oxidative detoxification proteins, as well as various transcription factors. These genes account for about 1% (266/27200) of the predicted genes in the sea anemone genome, similar to the proportion observed in tunicates and humans, but lower than that observed in sea urchins. While there are comparable numbers of stress-response genes, the stress sensor genes appear to be reduced in N. vectensis relative to many model protostomes and deuterostomes. Cnidarian toxicology is understudied, especially given the important ecological roles of many cnidarian species. New genomic resources should stimulate the study of chemical stress sensing and response mechanisms in cnidaria, and allow us to further illuminate the evolution of chemical defense gene networks.WHOI Ocean Life Institute and NIH R01-ES01591

    Morphometric study of the root anatomy in furcation area of mandibular first molars

    Get PDF
    Furcation involvement in periodontal disease has been a challenge for the dentist. OBJECTIVE: The aim of this study was to investigate root dimensions in the furcation area of 233 mandibular first molars. MATERIAL AND METHODS: Digital photomicrographs were used to obtain the following measurements on the buccal and lingual surfaces of each tooth: root trunk height (RT), horizontal interadicular distance obtained 1 mm (D1) and 2 mm (D2) below the fornix and interadicular angle (IA). RESULTS: Mean± standard deviation of buccal and lingual furcation measurements were, respectively, 1.37±0.78 mm and 2.04±0.89 mm for RT; 0.86±0.39 mm and 0.71±0.42 mm for D1; 1.50±0.48 mm and 1.38±0.48 mm for D2; 41.68±13.20º and 37.78±13.18º for IA. Statistically significant differences were found between all measured parameters for buccal and lingual sides (p<0.05, paired t test). CONCLUSIONS: In conclusion, the lingual furcation of mandibular first molars presented narrower entrance and longer root trunk than the buccal furcation, suggesting more limitation for instrumentation and worse prognosis to lingual furcation involvements in comparison to buccal lesions
    corecore