Predicting the Next Maxima Incidents of the Seasonally Forced SEIR Epidemic Model

This paper aims at predicting the next maxima values of the state variables of the seasonal SEIR epidemic model and their in-between time intervals. Lorenz's method of analogues is applied on the attractor formed by the maxima of the corresponding state variables. It is found that both quantities are characterized by a high degree of predictability in the case of the chaotic regime of the parameter space.Comment: 6 pages, 3 figures, 2 tables, typos adde

Gingival recession: prevalence and risk indicators among young greek adults

Objectives: The aim of the current research was to assess the prevalence of gingival recession and to investigate possible associations among this condition, periodontal and epidemiological variables in a sample of young Greek adults in a general dental practice. Material and Methods: A total of 1,430 young adults was examined clinically and interviewed regarding several periodontal and epidemiological variables. Collected data included demographic variables, oral hygiene habits and smoking status. Clinical examination included the recording of dental plaque, supragingival calculus presence, gingival status and buccal gingival recession. Multivariate logistic regression analysis model was performed to access the possible association between gingival recession and several periodontal and epidemiological variables as potential risk factors. Results: The overall prevalence of gingival recession was 63.9%. The statistical analysis indicated that higher edu - cational level [OR= 2.12, 95% CI= 0.53-8.51], cigarette smoking [OR= 1.97, 95% CI= 1.48-7.91], frequent tooth brushing [OR= 0.98, 95% CI= 0.56-1.96], presence of oral piercing [OR= 0.92, 95% CI= 0.38-1.58], presence of gingival inflammation [OR= 4.54, 95% CI= 1.68-7.16], presence of dental plaque [OR= 1.67, 95% CI= 0.68-2.83] and presence of supragingival calculus [OR=1.34, 95% CI= 0.59-1.88], were the most important associated factors of gingival recession. Conclusions: The observations of the current research supported the results from previous authors that several periodontal factors, educational level and smoking were significantly associated with the presence of gingival re - cession, while presence of oral piercing was a new factor that was found to be associated with gingival recession

Prevalence of tooth erosion and associated factors in 13-16-year old adolescents in Greece

Objectives: The aim of this study was to estimate the prevalence of dental erosion and to investigate possible associations among dental erosion and medical history, dietary and lifestyle habits in a sample of adolescents in Greece. Study design: The study sample consisted of 770 adolescents, 374 boys and 396 girls aged 13 to 16 years. All individuals were clinically examined and answered questions regarding their medical history, rate and frequency of drinks and food consumption and lifestyle habits. Statistical analysis of the questionnaire items was performed by using the multiple logistic regression analysis model. Results: Two hundreds and sixty adolescents were diagnosed as having dental erosion, giving a prevalence rate 33.8%. The habit of holding drinks in the mouth before swallowing [OR=2.85, 95% CI=1.45-5.58] (p=0.002), the ingestion of acidic drinks at bedtime [OR=0.24, 95% CI=0.11-0.53] (p=0.000), the consumption of car- bonated drinks [OR=3.99, 95% CI=1.37-11.59] (p=0.011) and fruit juices [OR=0.12, 95% CI=0.04-0.38] (p=0.000) were the most important associated factors of dental erosion. Conclusions: The prevalence of dental erosion in the study sample was 33.8% while dental erosion experience was associated with frequency and habits of consumption of some dietary components

Prevalence of Dentine Hypersensitivity in a General Dental Practice in Greece

Objectives: The aim of this study was to estimate the prevalence of dentine hypersensitivity in a sample of patients visiting a general dental practice. Study design: The study population consisted of 1,450 patients, 690 males and 760 females, aged 18-69 years. All individuals were clinically examined and answered questions regarding variables such as gender, age, educational level, occupation status, teeth affected and any factor that initiated the sensitivity. The clinical examination involved assessment of sensitive teeth per patient, while the amount of buccal gingival recession associated with the sensitive teeth was also recorded. Statistical analysis performed by using methods of descriptive statistics and chi square-test. Results: Two hundred and sixty four patients were diagnose as having dentine hypersensitivity, giving a prevalence rate 18.2% . Prevalence rate for hypersensitivity in females (19.34%) was significantly higher (p=0.0015) than males (16.95%). The mean number of sensitive teeth per patient showed a peak in the 40-49 year age group in males and in 60-69 year age group in females. The commonest teeth affected by dentine hypersensitivity were the first and second premolars, the canines and the first molars of maxilla and mandible. The majority (85.9%) of sensitive teeth had at least 1-3 mm of gingival recession while the most commonest pain-initiating stimuli was the consumption of cold drinks (56.1%). A statistically significant difference recorded between dentine hypersensitivity and educational level (p=0.00094). Conclusions: The prevalence of dentine hypersensitivity in the adult sample of the present study was 18.5%. There was also a tendency for the patients with sensitive teeth to come from higher social classe

THE ASSOCIATION BETWEEN TRAUMATIC BRAIN INJURY AND GLIOMAGENESIS AND ITS SPECIAL ROLE IN GLIOBLASTOMA MULTIFORME PATHOGENESIS: A REVIEW

Gliomas are the most common primary and aggressive intracranial tumors, represent 80% of malignant brain tumors, and despite the fact that are relatively rare tumors are responsible for significant mortality and morbidity. Glioblastoma multiforme (GBM) or diffuse astrocytoma, WHO grade IV, is the most common and aggressive primary central nervous system malignancy, represents 45% of all gliomas, shows an average incidence of 3.19/100,000 individuals, its median age of diagnosis is 64 years, and the median survival is 15 months as the 5-year relative survival is 5%. Previous studies have investigated the possible role of genetic and environmental factors in GBM pathogenesis; however, the majority of GBM cases were sporadic and certain risk factors have not been detected. GBM is divided into primary and secondary subtypes which develop through different genetic pathways, affect patients at different ages, and have differences in clinical outcomes, as show a great morphological and genetic heterogeneity. The role of traumatic brain injury (TBI) in GBM formation has been investigated in many previous reports which have hypothesized that TBI may predispose to gliomagenesis; however, the outcomes were highly controversial. Some of those researches have proposed a supposed pathogenesis model that involves a post-traumatic inflammation, stem and progenitor cell transformation, and gliomagenesis. Other similar studies have involved transcription factors associated with TBI such as p53, hypoxia-inducible factor-1a (HIF-1a), and c-Myc. On the other hand, the possibility of a pre-existing tumor rather than a trauma-induced tumor is very possible in such cases

An events based algorithm for distributing concurrent tasks on multi-core architectures

In this paper, a programming model is presented which enables scalable parallel performance on multi-core shared memory architectures. The model has been developed for application to a wide range of numerical simulation problems. Such problems involve time stepping or iteration algorithms where synchronization of multiple threads of execution is required. It is shown that traditional approaches to parallelism including message passing and scatter-gather can be improved upon in terms of speed-up and memory management. Using spatial decomposition to create orthogonal computational tasks, a new task management algorithm called H-Dispatch is developed. This algorithm makes efficient use of memory resources by limiting the need for garbage collection and takes optimal advantage of multiple cores by employing a “hungry” pull strategy. The technique is demonstrated on a simple finite difference solver and results are compared to traditional MPI and scatter-gather approaches. The H-Dispatch approach achieves near linear speed-up with results for efficiency of 85% on a 24-core machine. It is noted that the H-Dispatch algorithm is quite general and can be applied to a wide class of computational tasks on heterogeneous architectures involving multi-core and GPGPU hardware.Schlumberger-Doll Research CenterSaudi Aramc

Tax policy cyclicality and financial development

This paper adds to the existing literature by examining the macroeconomic, political and institutional determinants of tax policy cyclicality conditional on financial development. We find that an increase in trade and financial openness leads to pro-cyclical VAT and counter-cyclical CIT rate response in high financially developed economies, while an increase in financial openness is associated with counter-cyclical VAT and PIT responses when the levels of financial development are low. A high public debt ratio leads to a counter-cyclical VAT rate response in economies with low financial development. Political power and fiscal institutions are factors that affect the tax policy cyclicality only in less financially developed economies

Clinically Classified Periodontitis and Its Association in Patients with Preexisting Coronary Heart Disease

The aim of this retrospective study was to investigate possible associations between clinically classified periodontitis as determined by assessing its severity and diagnosed coronary heart disease in outpatients referred to a specialist clinic for neurosurgery treatment. A total of 2,912 individuals were clinically examined for periodontal disease experience by using probing pocket depth (PPD) and clinical attachment loss (CAL). Socioeconomic, oral health behaviour, and general health related information was collected by using a self-administered questionnaire. Statistical analysis of the questionnaire items was performed by using multivariate logistic regression analysis model. The results showed that the occurrence of hypertension (OR=2.42, 95% CI = 1.52–3.84), smoking (OR=1.97, 95% CI = 1.25–3.11), classified periodontitis (OR=1.79, 95% CI = 1.15–2.77), and the high level of serum C-reactive protein (OR=1.74, 95% CI = 1.05–2.89) were significantly associated with the presence of coronary heart disease. These observations strengthen the role of some of the traditional causative risk factors for coronary heart disease while a significant association was recorded between diagnosed coronary heart disease and clinically classified periodontitis which is considered as a risk factor for coronary heart disease.</jats:p

Examination of the Relation Between Periodontal Disease Indices in Patients with Systemic Diseases

Svrha: Željelo se ispitati koliki je indeks parodontne bolesti kod pacijenata upućenih na Odjel neurokirurgije te njegova povezanost s češćim sistemskim bolestima među odraslim vanjskim pacijentima u Grčkoj. Materijal i metode: Analizirana populacija sastojala se od 728 vanjskih pacijenata – 340 muškaraca i 388 žena u dobi od 40 do 70 godina. Svi su klinički pregledani i ispunili su zdravstveni upitnik. Ti su podatci raščlanjeni višestrukom logističkom regresijskom analizom za procjenu mogućih poveznica između sistemskih bolesti kao neovisnih varijabli, a kao poveznica ovisnih varijabli analizirani su parodontni džepovi od pet milimetara i više, blagi do umjereni gubitak kliničkog pričvrstka, krvarenje ili nekrvarenje nakon sondiranja te vidljive zubne naslage. Rezultati: Dubina parodontnih džepova bila je značajno i pozitivno povezana s respiratornim alergijama (P<0,001) i šećernom bolešću (P<0,001), te reumatoidnim artritisom (P=0,048). Krvarenje nakon sondiranja također je bilo povezano s respiratornim alergijama (P=0,009), kardiovaskularnim bolestima (P<0,001) i dijabetesom (P<0,001), a značajno negativno s hipertenzijom (P<0,001). Zubne naslage bile su pozitivno povezane s reumatoidnim artritisom (P=0,048). Zaključak: Pronađena je velika povezanost indeksa parodontnih bolesti, poput dubine sondiranja, gubitka kliničkog pričvrstka te zubnih naslaga i sistemskih bolesti, poput kardiovaskularnih i respiratornih, dijabetesa i reumatoidnog artritisa.Aim: The aim of the current investigation was to examine the occurrence of periodontal disease indices in out-patients referred to a specialist clinic for neurosurgery treatment and to explore possible associations between common systemic diseases and periodontal disease indices in a Greek out-patient adult population. Materials and Methods: The study population consisted of 728 out-patients, 340 males and 388 females aged 40 to 70 years. All individuals were clinically examined and filled in a health administered questionnaire. Multiple logistic regression analysis of the questionnaire items was performed to assess possible associations between systemic diseases as independent variables and the presence of periodontal pockets of 5.00 mm or more, mild/moderate or severe clinical attachment loss and the presence or absence of bleeding on probing and visible dental plaque, respectively, as dependent variables. Results: The depth of periodontal pockets was significantly and positively associated with the presence of respiratory allergy (P<0.001) and diabetes mellitus (P<0.001), whereas clinical attachment loss was significantly and positively associated with the presence of respiratory allergy (P<0.001), diabetes mellitus (P<0.001) and rheumatoid arthritis (P= 0.048). In addition, bleeding on probing was significantly and positively associated with the presence of respiratory allergy (P= 0.009), cardiovascular disease (P<0.001) and diabetes mellitus (P<0.001) and significantly and negatively associated with the presence of hypertension (P<0.001), whereas the presence of dental plaque was positively associated with the presence of rheumatoid arthritis (P= 0.048). Conclusion: Significant associations between investigated periodontal disease indices such as probing pocket depth, clinical attachment loss, bleeding on probing and dental plaque and systemic diseases such as respiratory diseases, diabetes mellitus, cardiovascular diseases and rheumatoid arthritis were recorded