534 research outputs found

    The role of thermal niche selection in maintenance of a colour polymorphism in redback salamanders (Plethodon cinereus)

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    BACKGROUND: In eastern North America two common colour morphs exist in most populations of redback salamanders (Plethodon cinereus). Previous studies have indicated that the different morphs may be adapted to different thermal niches and the morphological variation has been linked to standard metabolic rate at 15°C in one population of P. cinereus. It has therefore been hypothesized that a correlated response to selection on metabolic rate across thermal niches maintains the colour polymorphism in P. cinereus. This study tests that hypothesis. RESULTS: We found that the two colour morphs do sometimes differ in their maintenance metabolic rate (MMR) profiles, but that the pattern is not consistent across populations or seasons. We also found that when MMR profiles differ between morphs those differences do not indicate that distinct niches exist. Field censuses showed that the two colour morphs are sometimes found at different substrate temperatures and that this difference is also dependent on census location and season. CONCLUSION: While these morphs sometimes differ in their maintenance energy expenditures, the differences in MMR profile in this study are not consistent with maintenance of the polymorphism via a simple correlated response to selection across multiple niches. When present, differences in MMR profile do not indicate the existence of multiple thermal niches that consistently mirror colour polymorphism. We suggest that while a relationship between colour morph and thermal niche selection appears to exist it is neither simple nor consistent

    Oral health status among migrants from middle-and low-income countries to europe: A systematic review

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    Introduction. Economic inequality, political instability and globalization have contributed to the constant growth of the migration phenomenon in recent years. In particular, a total of 4.2 million people migrated to Europe during 2019 and most of them settled in Germany, France and Italy. Objectives. The objective of this study was to conduct a systematic review of studies analyzing the oral health condition among migrants from middle-and low-income countries to Europe and assessing the eventual association between their sociodemographic and socioeconomic characteristics and oral health status. Materials and Methods. A systematic review was conducted in PubMed, Cochrane Library, Scopus and Science Direct databases. After titles, abstracts and full-text exami-nation, only 27 articles were selected on the basis of inclusion criteria and consequently included for quality assessments and data extraction. Results. Most of the studies reported a higher prevalence of caries experience, a poorer periodontal health and more difficulties in accessing dentalcare services among migrant groups compared with the non-migrant population. Inequalities were mostly associated with ethnic background, economic condition and social grade. Conclusion. Our review demonstrates the lack of dental health among migrants, underlining that their cultural beliefs and their social and economic living conditions could influence their oral health

    Disponibilidad mensual de fitomasa aérea total y en distintos compartimentos de un pastizal bajo en la región de colinas de La Pampa

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    The work was done in a short grassland in the area of La Pampa hills (Toay department), to determine above ground standing crop, total and of the different compartments. Cuts were done monthly in -an area previously grazed, during a whole year's sampling. Total standing crop of aerial biomass was of 173 gDM/m2 of annual average. The most important valuable species were: Poa ligularis, Piptochaetium napoataense, Bothriochloa springfieldii y Rhynchoaia senna. Living biomasa compartment was at its maximum in summer months, with its greatest contribution in January (131 gDM/m2). The standing dead material increased in autumn reaching the maximum value in June (168 gDM/m2); while the litter had its highest value in September (288 gDM/m2) The grassland studied resulted being biseasonal with a period of greater growing by the end of spring-summer and another minor by the middle of autumn. The passage of the living material to the standing dead compartment was quick. It was also quick the convertion to litter in spring, as a consequence of the intensity of the winds.El trabajo fue realizado en un pastizal bajo, en la región de las colinas de La Pampa (Dpto. Toay), para determinar disponibilidad total aérea y de los distintos compartimentos. Los cortes se realizaron mensualmente en un área previamente pastoreada, a lo largo de un año de muestreo. La disponibilidad de fitomasa aérea total fue de 173 gMS/m2 de promedio anual. Las especies valiosas más importantes fueron Poa ligularis, Piptochaetium napostaense, Bothriochloa springfieldii y Rhynchosia senna. La fitomasa del compartimento vivo fue máxima en los meses de verano con el mayor aporte en Enero (131 gMS/m2). El material muerto en pie aumentó en otoño hasta alcanzar el máximo valor en Junio (168 gMS/m2); mientras que la broza tuvo el mayor valor en setiembre (288 gMS/m2). El pastizal estudiado resultó ser bi-estacional con un período de crecimiento mayor a fines de primavera-verano y otro menor a mediados de otoño. El pasaje de material vivo al compartimento muerto en pie fue rápido. También lo fue la aparici6n de broza en primavera a causa de la intensidad de los vientos

    Osteoradionecrosis of the jaws due to teeth extractions during and after radiotherapy: A systematic review

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    Teeth extractions before or after radiotherapy (RT) could be procedures at high risk for osteoradionecrosis (ORN) onset. This systematic review was performed to investigate the ORN incidence following teeth extractions during and after RT for head and neck (H&N) cancer and to evaluate any other possible risk factor. Methods: This systematic review was conducted according to PRISMA protocol, and the PROSPERO registration number was CRD42018079986. An electronic search was performed on the following search engines: PubMed, Scopus, and Web of Science. A cumulative meta‐analysis was performed. Results: Two thousand two hundred and eighty‐one records were screened, and nine were finally included. This systematic review revealed an ORN incidence of 5.8% (41 patients out of 462, 95% CI = 2.3–9.4); 3 ORN developed in the maxilla. No other clinical risk factors were detected. Conclusion: Post‐RT teeth extractions represent a major risk factor for ORN development, especially in the mandible, with a diminishing trend in the last years. Further research on other possible risk factors might improve this evidence

    Performance of a Simplified Soft-Distance decoding algorithm for LDPC codes over the Rayleigh fading channel

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    In this paper, we investigate the performance of a Soft-Input soft-Output decoding algorithm for LDPC codes that uses Euclidean distance as its metric, in the Rayleigh fading channel. It is found that its Bit Error Rate performance is close to that of traditional decoding algorithms like the SumProduct algorithm and its logarithmic version. Main characteristics of the proposed algorithm and its modification to perform over the Rayleigh channel are described. This algorithm uses squared Euclidean distance as the metric, does not require knowledge of the signal-to-noise ratio of the received signal, and is less complex to implement than other soft-input, soft-output algorithms.Fil: Arnone, Leonardo Jose. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Liberatori, Mónica Cristina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Electrónica. Laboratorio de Comunicaciones; ArgentinaFil: Petruzzi, David Mario. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Electrónica. Laboratorio de Comunicaciones; ArgentinaFil: Farrell, P. G.. Lancaster University. Department of Communications Systems; Reino UnidoFil: Castiñeira Moreira, Jorge. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata; Argentin

    Topical application of chlorhexidine gel with brush-on technique in the tailored treatment of plaque induced gingivitis

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    Aim: This study aimed to assess the action of a chlorhexidine-based brush-on gel application in the treatment of plaque-related gingivitis. Methods: The enrollment involved consecutive patients diagnosed with plaque-induced gingivitis. Each participant's full mouth plaque score and gingival index were recorded at the first appointment (t0) and at follow ups after 1 week (t1), 2 weeks (t2) and 3 weeks (t4). All patients were randomly sorted into two groups: A study group, who was given instruction to brush their gums daily with a chlorhexidine gel, and a control group who received a placebo gel. The two groups' data at baseline were compared using a chi-square test, while the t-Student and Mann-Whitney tests were employed to analyze the index's trends, both separately and compared. Results: In total, 30 patients were enrolled, 15 referring to the study group and 15 to the control group. The study group had an 87% decrease in their plaque score and an 84% decrease in their gingival index (p < 0.05). The control group displayed a reduction in plaque score and gingival index of 74% and 84%, respectively (p < 0.05). The plaque score decreased statistically more significantly in the study group than in the control group. Conclusion: Topical employment of a chlorhexidine-containing brush-on gel appears to be a useful home tool in the treatment of plaque-induced gingivitis, associated with professional debridement

    The effect of ceramic YSZ powder morphology on coating performance for industrial TBCs

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    The increasing turbine inlet temperatures in modern gas turbines have raised concerns about the corrosion of ceramic thermal barrier coatings (TBCs) caused by molten silicate deposits, commonly referred to as “CMAS” due to their main constituents (CaO-MgO-Al2O3-SiO2). The objective of this study was to investigate the combined influence of powder morphology and chemical composition on the CMAS resistance and thermal cycling resistance of ceramic monolayer and bi-layer coatings created through Atmospheric Plasma Spraying (APS). Three powder morphologies were examined: porous Agglomerated and Sintered (A&S) granules, Hollow Spherical (HOSP) powders, and dense, irregular Fused and Crushed (F&C) particles. Monolayer 7-8YSZ coatings with both porous and dense vertically cracked (DVC) microstructures, and bi-layer coatings consisting of a bottom layer of porous standard 7-8YSZ and a top layer composed of a porous high‑yttrium ZrO2–55 wt% Y2O3 were obtained using all three powder types (A&S, HOSP, or F&C). Furthermore, the bi-layer systems were deposited with different ratios between the individual layer thicknesses and/or different total thickness. FEG-SEM, EDX, and micro-Raman analyses, were conducted to assess the coatings' performance. Nanoindentation high-speed mapping and pillar splitting test were performed to evaluate the mechanical behaviour. The study on 8YSZ monolayers shows that coatings from a F&C feedstock exhibit higher density, reducing the CMAS penetration. However, these coatings demonstrate poorer thermal cycling performance due to increased stiffness and thermal stresses. Coatings from HOSP and A&S powders allow CMAS penetration but offer stress relief pathways, enhancing the coating's ability to withstand thermal stresses. Bi-layer coatings with a 55YSZ top coat show superior CMAS resistance compared to 7-8YSZ monolayer coatings, with limited penetration causing top coat peeling. The thickness ratio between the layers also affects thermal cycling resistance, where a thinner 55YSZ layer extends the TBC lifetime

    Proteomic peptide scan of porphyromonas gingivalis fima type II for searching potential B-cell epitopes

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    Purpose. To identify potential antigenic targets for Porphyromonas gingivalis vaccine development. Materials and methods. In the present study, we analyzed the Porphyromonas gingivalis, fimA type II primary amino acid sequence and characterized the similarity to the human proteome at the pentapeptide level. Results. We found that exact peptide-peptide profiling of the fimbrial antigen versus the human proteome shows that only 19 out of 344 fimA type II pentapeptides are uniquely owned by the bacterial protein. Conclusions. The concept that protein immunogenicity is allocated in rare peptide sequences and the search the Porphyromonas gingivalis fimA type II sequence for peptides unique to the bacterial protein and absent in the human host, might be used in new therapeutical approaches as a significant adjunct to current periodontal therapies
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