Synchronization learning of coupled chaotic maps

We study the dynamics of an ensemble of globally coupled chaotic logistic maps under the action of a learning algorithm aimed at driving the system from incoherent collective evolution to a state of spontaneous full synchronization. Numerical calculations reveal a sharp transition between regimes of unsuccessful and successful learning as the algorithm stiffness grows. In the regime of successful learning, an optimal value of the stiffness is found for which the learning time is minimal

Maxillary nerve block: A comparison between the greater palatine canal and high tuberosity approaches.

Aim: Analgesia and anxiolysis during dental procedures are important for dental care and patient compliance. This study aims to compare two classical maxillary nerve block (MNB) techniques: the greater palatine canal (GPC) and the high tuberosity (HT) approaches, seldom used in routine dental practice. Methods: The study was conducted on 30 patients, scheduled for sinus lift surgery, who were randomly divided into 2 groups: the GPC approach to the MNB was used in 15 and the HT one in the other 15 patients. Anxiolysis was also used, depending on the results of the pre- preoperative assessment. Patients\u2019 sensations/pain during the procedure, details about anesthesia, and the dentist\u2019s considerations were all recorded. Data are expressed as mean \ub1SD. Statistical tests including ANOVA, \u3c72 following Yates correction and linear regression analysis were carried out. A < 0.05 p value was considered significant. Results: Study results showed that the anesthesia was effective and constant in the molar and premolar area. Additional infiltrations of local anesthetics were necessary for vestibular and palatal areas in the anterior oral cavity, respectively, in the GPC and HT groups. The two techniques were equally difficult to carry out in the dentist\u2019s opinion. There were no differences in pain or unpleasant sensations between the two groups, nor were any anesthesia-related complications reported. Conclusion: The GPC approach ensures effective anesthesia in the posterior maxillary region as far as both the dental pulp and the palatal/vestibular mucous membranes are concerned; the HT approach did not guarantee adequate anesthesia of the pterygopalatine branch of the maxillary nerve. These regional anesthesia techniques were characterized by a low incidence of intra and postoperative pain, no noteworthy complications, and high patient satisfaction

Oral malodor in Special Care Patients: current knowledge

Epidemiological studies report that about 50% of the population may have oral malodor with a strong social and psychological impact in their daily life. When intra-oral causes are excluded, referral to an appropriate medical specialist is paramount for management and treatment of extra-oral causes. The intra-oral causes of halitosis are highly common, and the dentist is the central clinician to diagnose and treat them. Pseudohalitosis or halitophobia may occur and an early identification of these conditions by the dentist is important in order to avoid unnecessary dental treatments for patients who need psychological or psychiatric therapy. The organoleptic technique is still considered the most reliable examination method to diagnose genuine halitosis. Special needs patients are more prone than others to have oral malodor because of concurrent systemic or metabolic diseases, and medications. The present report reviews halitosis, its implications, and the management in special care dentistry

Demographic growth and the distribution of language sizes

It is argued that the present log-normal distribution of language sizes is, to a large extent, a consequence of demographic dynamics within the population of speakers of each language. A two-parameter stochastic multiplicative process is proposed as a model for the population dynamics of individual languages, and applied over a period spanning the last ten centuries. The model disregards language birth and death. A straightforward fitting of the two parameters, which statistically characterize the population growth rate, predicts a distribution of language sizes in excellent agreement with empirical data. Numerical simulations, and the study of the size distribution within language families, validate the assumptions at the basis of the model.Comment: To appear in Int. J. Mod. Phys. C (2008

O plastocrono e o filocrono em Araucaria angustifolia (Bert.) O. Ktze., no município de Colombo, Paraná.

EVINCI. Resumo 014

Interacting Individuals Leading to Zipf's Law

We present a general approach to explain the Zipf's law of city distribution. If the simplest interaction (pairwise) is assumed, individuals tend to form cities in agreement with the well-known statisticsComment: 4 pages 2 figure