Copyright © 2017, SEPM (Society for Sedimentary Geology). Fossil assemblages are expected to be time-averaged as a result of biological and physical processes that mix skeletal remains. Our quantitative understanding of time-averaging derives primarily from actualistic studies, in which direct numerical dating of individual specimens is used to assess the scale and structure of age mixing in death assemblages (incipient fossil assemblages). Here we examine the age, and the time-averaging of Mactra shells (Bivalvia: Mollusca) gathered from surface mixed siliciclastic-bioclastic sands at three sites on a passive-margin subtropical shelf (the Southern Brazilian Shelf; ∼ 33°S). Sixty Mactra specimens were individually dated using amino acid racemization (AAR) calibrated using radiocarbon ages (n=15). The time-averaging and the total age variability was based on a Bayesian approach that integrates the estimation errors and uncertainties derived from the posterior distribution associated with the AAR calibration average model. The 14C-calibrated AAR ages, pooled across all three sites, are strongly right-skewed with 97{%} of the individual mollusk shell age estimates ranging from 0 to 6 cal kyr BP. The magnitude of time-averaging varied inversely with the water depth, from {\textless} 15 yr at the deepest site (21 m) up to 1020-1250 yr at the shallowest site (7 m). The substantial variation in the temporal resolution across nearby sites, which are located in a seemingly homogenous depositional setting, indicates the presence of notable (if cryptic) spatial heterogeneities in local sedimentation, production, and exhumation, all increasing with water depth.

© 2017 Ochi Agostini et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Empty mollusk shells may act as colonization surfaces for sclerobionts depending on the physical, chemical, and biological attributes of the shells. However, the main factors that can affect the establishment of an organism on hard substrates and the colonization patterns on modern and time-averaged shells remain unclear. Using experimental and field approaches, we compared sclerobiont (i.e., bacteria and invertebrate) colonization patterns on the exposed shells (internal and external sides) of three bivalve species (Anadara brasiliana, Mactra isabelleana, and Amarilladesma mactroides) with different external shell textures. In addition, we evaluated the influence of the host characteristics (mode of life, body size, color alteration, external and internal ornamentation and mineralogy) of sclerobionts on dead mollusk shells (bivalve and gastropod) collected from the Southern Brazilian coast. Finally, we compared field observations with experiments to evaluate how the biological signs of the present-day invertebrate settlements are preserved in molluscan death assemblages (incipient fossil record) in a subtropical shallow coastal setting. The results enhance our understanding of sclerobiont colonization over modern and paleoecology perspectives. The data suggest that sclerobiont settlement is enhanced by (i) high(er) biofilm bacteria density, which is more attracted to surfaces with high ornamentation; (ii) heterogeneous internal and external shell surface; (iii) shallow infaunal or attached epifaunal life modes; (iv) colorful or post-mortem oxidized shell surfaces; (v) shell size ( {\textless} 50 mm2 or {\textgreater} 1,351 mm 2 ); and (vi) calcitic mineralogy. Although the biofilm bacteria density, shell size, and texture are considered the most important factors, the effects of other covarying attributes should also be considered. We observed a similar pattern of sclerobiont colonization frequency over modern and paleoecology perspectives, with an increase of invertebrates occurring on textured bivalve shells. This study demonstrates how bacterial biofilms may influence sclerobiont colonization on biological hosts (mollusks), and shows how ecological relationships in marine organisms may be relevant for interpreting the fossil record of sclerobionts relationships in marine organisms may be relevant for interpreting the fossil record of sclerobionts.

Virtual Reference Feedback Tuning (VRFT) is a data-driven technique used to design controllers without the need of a process model, only input-output data is utilized. When the process has non-minimum phase (NMP) zeros, the original method usually presents poor performance, because scarcely the reference model has the same NMP zeros as the process. To overcome this problem, a flexible criterion has been proposed to the VRFT method, in a way that both the controller parameters and the NMP zeros of the process are estimated together. In this paper we present the application of the VRFT method with flexible criterion to the level control of a MIMO pilot plant. We show that a sequential controller design may incorporate NMP behavior to the process. We then use the VRFT method with flexible criterion to design the controller using only closed-loop data from the process.

This paper considers the design and implementation of a discrete-time fast tracking controller for quadrotor vehicles subject to perturbations. The proposed controller consists of a model-based disturbance observer and a Composite Nonlinear Feedback (CNF) controller. The CNF control law introduces nonlinear damping to the system so that it possesses a fast rise time without overshoot. The least square identification method is applied to develop a model based disturbance observer, thus decoupling the problems of track following and disturbance rejection. Experimental results are provided in order to validate the proposed approach.

In this work a modified Resonant Controller is proposed to deal with the tracking/rejection problem of periodic signals robust to period variations and parametric uncertainties in the plant. The control strategy is based on a resonant structure in series with a notch filter, which will be responsible to improve the robustness to period variation. A robust state feedback controller is designed by solving a linear matrix inequality (LMI) optimization problem guaranteeing the robust stability of the closed loop system. A numerical example is presented to illustrate the method.

Little is known about the factors that may be used in clinical practice to predict the therapeutic response of aggressive periodontitis patients. The aim of this study was to determine predictors of clinical outcomes after non-surgical treatment of aggressive periodontitis. A total of 24 patients (aged 13-26 years) received oral hygiene instructions, as well as subgingival scaling and root planing. Twelve subjects received systemic azithromycin at random. Clinical variables were assessed at baseline, 3, 6, 9, and 12 months. Baseline microbiological assessment was performed by checkerboard DNA-DNA hybridization. Multivariable models used generalized estimating equations. There were significant improvements in the entire sample in regard to pocket depth, clinical attachment level and bleeding on probing. Significant predictors of a reduction in mean pocket depth were: use of azithromycin, non-molar teeth, generalized disease and baseline pocket depth. Absence of plaque predicted a 0.22 mm higher attachment gain, whereas a baseline pocket depth >/=7 mm predicted a 1.36 mm higher attachment loss. Azithromycin, plaque, and baseline pocket depth were significant predictors of bleeding on probing. The concomitant presence of all three red complex species predicted a 0.78 mm higher attachment loss. It may be concluded that dental plaque, tooth type, disease extent, baseline pocket depth, and use of azithromycin were significant predictors of the clinical response to treatment for aggressive periodontitis in young individuals. Moreover, the presence of multiple periodontal pathogens may predict challenges in achieving a favorable outcome for aggressive periodontitis.

Iterative Feedback Tuning (IFT) is a data-driven method used to tune parameters of feedback controllers minimising an H2 criterion. The method uses data from experiments to estimate the gradient of the criterion, and uses iterative quasinewton algorithms to adjust the controllers. When the method is used in cascade systems, usually the inner loop is firstly adjusted, and after the outer loop. In this article we describe an extension to the IFT method that adjusts both inner and outer loop at the same time using only data from closed-loop experiments at each iteration.

MATERIAL AND METHODS: This cross-sectional study included 91 patients with stable CAD who had been under optimized cardiovascular care. Blood levels of IL-1beta, IL-6, IL-8, IL-10, IFN-gamma, and TNF-alpha were measured by Luminex technology. A full-mouth periodontal examination was conducted to record probing depth (PD) and clinical attachment (CA) loss. Multiple linear regression models, adjusting for gender, body mass index, oral hypoglycemic drugs, smoking, and occurre:nce of acute myocardial infarction were applied. RESULTS: CAD patients that experienced major events had higher concentrations of IFN-gamma (median: 5.05 pg/mL vs. 3.01 pg/mL; p=0.01), IL-10 (median: 2.33 pg/mL vs. 1.01 pg/mL; p=0.03), and TNF-alpha (median: 9.17 pg/mL vs. 7.47 pg/mL; p=0.02). Higher numbers of teeth with at least 6 mm of CA loss (R2=0.07) and PD (R2=0.06) were significantly associated with higher IFN-gamma log concentrations. Mean CA loss (R2=0.05) and PD (R2=0.06) were significantly related to IL-10 concentrations. Elevated concentrations of TNF-alpha were associated with higher mean CA loss (R2=0.07). CONCLUSION: Periodontal disease is associated with increased systemic inflammation in stable cardiovascular patients. These findings provide additional evidence supporting the idea that periodontal disease can be a prognostic factor in cardiovascular patients.

AIM: The aim of this study was to assess the effect of overweight and obesity on periodontal attachment loss (PAL) progression in an urban population from south Brazil. METHODS: In 2001, a population-based oral health survey entitled "Epidemiology of periodontal diseases: the Porto Alegre Study" was conducted by drawing a probabilistic sample of 1586 individuals. After 5 years, 755 (participation rate: 47.6%) individuals were re-examined. For this analysis, self-reported diabetics, underweight individuals, and individuals with <6 teeth were excluded. Poisson regressions were used to calculate relative risks (RR) and 95% confidence intervals (CI) adjusted for sex, age, skin colour, education, socio-economic status, smoking and dental care. RESULTS: Five hundred and eighty-two individuals (333 males/249 females, 36.02 +/- 14.97 years) were included. Overall, obese individuals had significantly higher risk of experiencing PAL progression than individuals with normal weight after adjusting for important co-factors (RR = 1.36, 95% CI = 1.04-1.78). In a stratified analysis, no statistically significant associations were observed between PAL progression and obesity for males (RR = 1.13, 95% CI = 0.75-1.69), whereas obese females were at statistically significant higher risk than normal weight females (RR = 1.64, 95% CI = 1.11-2.43). CONCLUSION: Obesity appears to be a risk factor for PAL progression for females but not males in this developing country population.

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OBJECTIVES: To evaluate the efficacy of EO as adjuncts to mechanical plaque control (MPC) on the reduction of plaque and gingivitis when compared to placebo or cetylpyridium chloride (CPC). DATA: Randomized controlled trials of at least 6 months of follow-up including systemically healthy individuals with gingivitis were included. SOURCES: MEDLINE, EMBASE, Lilacs and SCOPUS were searched up to April 2016. From 3045 citations, 16 studies were included. 14 studies assessed the Quigley-Hein Plaque Index (QHI) and 11 studies assessed the Modified Gingival Index (MGI) and were included in meta-analyses and meta-regression. STUDY SELECTION: The analysis of risk of bias suggested that the quality of the studies ranged from moderate to low. Mean QHI (WMD=-0.86, 95%CI -1.05 to -0.66) and MGI (WMD=-0.52, 95%CI -0.67 to -0.37) were lower for EO+MPC than placebo+MPC. Reductions in plaque and gingivitis were, respectively, 32% and 24% larger for EO+MPC than placebo+MPC. The decreases in QHI (WMD=-0.95, 95%CI -1.26 to -0.63) and in MGI (WMD=-0.34, 95%CI -0.53 to -0.15) observed in the EO+MPC group, compared to placebo+MPC in interproximal areas, were significantly different and in favor to EO+MPC. EO+MPC compared to CPC+MPC resulted in clinically lower levels of plaque and gingivitis. High heterogeneity (I(2)>95%) was found and explained (MGI-R(2)=63.6%; QHI-R(2)=80.1%) by differences between studies in the percentage of males, supervision of the mouthwashes and provision of oral hygiene. CONCLUSIONS: EO seems to be superior to placebo+MPC and CPC+MPC for reduction of plaque and gingival inflammation in patients with gingivitis. Expected benefits may be clinically relevant and may also reach the interproximal area. CLINICAL SIGNIFICANCE: Mouthwashes containing essential oils should be considered the first choice for daily use as adjuvants to self-performed mechanical plaque control.

The present study aimed to assess the rate of agreement between clinical and histopathological diagnoses and to report the frequency of completed forms for specimens that were subjected to histopathological examination and retrospectively examined. Data from 8,168 specimens submitted to histopathological examination were retrieved from the records. A total of 5,368 cases were included. Agreement was defined based on the definition of lesion nature according to its diagnostic category. Sensitivity, specificity, and positive and negative predictive values were calculated for each diagnostic category. The highest rate of agreement was observed for periapical lesions (92.6%), followed by potentially malignant disorders (90.1%) and non-neoplastic proliferative disorders (89.3%). Low rates of histopathological confirmation of the clinical impression were observed for mesenchymal tumors (25.0%) and cysts (44.2%). Sensitivity values were > 0.70 for all lesions, except for cysts (0.51). Specificity was relatively high, ranging from 0.97 to 1.00. The frequency of incomplete biopsy forms ranged from 16.8% (malignant tumors of oral mucosal epithelium) to 51.0% (nonspecific inflammatory reaction). The most frequently completed biopsy forms corresponded to epithelial malignant tumors (83.2%) and glandular inflammation (72.3%). In conclusion, there was an acceptable level of agreement. The low level of completeness of biopsy forms indicates little awareness about the relevance of gathering detailed information during clinical examination.

Halitosis is still poorly studied in young adults. The aim of this study was to evaluate the occurrence of self-reported halitosis and associate it with demographic and behavioral factors in young adult dental students. This cross-sectional study was designed as a census of students enrolled in three initial and three final semesters of a dental course in a Brazilian public university. Of 284 eligible students, 257 (90.5%) completed a self-administered questionnaire. Self-reported halitosis was the primary study outcome, and was assessed with the question "do you feel you have bad breath?". Data on age, gender, frequency of tooth brushing and interproximal cleaning, tongue cleaning, mouth rinse use and dry mouth were collected using the questionnaire, and were considered independent variables. Of the students surveyed, 26.5% reported as never, 51.7% as rarely, 21.4% as sometimes, and 0.4% as always feeling they had halitosis. Morning halitosis was reported by 90.6% of those who reported halitosis. In the final multiple model, last semester students had a 55% lower chance of reporting halitosis, compared with students from the first semesters [odds ratio (OR) 0.46; 95%CI 0.24-0.89]. Women had a 2.57fold higher chance of reporting halitosis (OR = 2.57; 95%CI 1.12-5.93). Dry mouth increased the chance of self-reported halitosis 3.95-fold, compared with absence of dry mouth (OR = 3.95; 95%CI 2.03-7.68). It can be concluded that self-reports of halitosis were low among dental students, but may represent an important complaint. Gender, dry mouth and level of college education of the dentist were factors significantly associated with self-reported halitosis.

OBJECTIVES: To assess the association between gingival recession (GR) and oral health-related quality of life (OHRQoL) in a Brazilian population of adults. METHODS: A representative sample from Porto Alegre city was drawn in 2011 using a multistage probability sampling strategy. For this study, 740 individuals, 35-59 years of age and with >/=6 teeth, were included. GR was assessed by two calibrated examiners at four sites in all present teeth. The Oral Health Impact Profile (OHIP-14) was used to assess OHRQoL. OHIP-14 was dichotomized using 'fairly often' as the cutoff point for a negative impact. Multiple logistic regression models were fitted to define which descriptors of GR were associated with the dichotomous outcome of OHIP-14, including dentine hypersensitivity in separate models, adjusting for age, gender, socioeconomic status, smoking, dental care, and missing teeth. RESULTS: Mean OHIP was significantly higher for individuals with >/=1 tooth with GR >/=2, >/=3, >/=4, and >/=5 mm. Individuals with >/=1 tooth with GR >/=2 mm had approximately two times higher chance of having a negative impact than individuals without GR of this threshold [odds ratio (OR) = 1.99, 95% confidence interval (CI) 1.05-3.78]. When buccal and proximal sites were analyzed separately, the presence of GR was significantly associated with worst quality of life only in anterior and not in posterior teeth. GR in the lower arch had no impact on OHRQoL. GR >/=2 mm affected only physical pain (OR = 2.61; 95% CI 1.06-6.42), whereas GR >/=4 mm affected functional limitation, physical pain, psychological discomfort, physical and psychological disabilities, with ORs ranging from 1.43 to 1.91. Dentine hypersensitivity alone was not associated with OHRQoL, but it modified the association between GR and OHIP when present concomitantly with GR, mainly in buccal sites. CONCLUSIONS: OHRQoL is poorer in this adult population in the presence of GR, mainly in upper and anterior teeth. Dentine hypersensitivity and esthetics were found to be factors linking GR to OHRQoL.