Wave localization in strongly nonlinear Hertzian chains with mass defect

We investigate the dynamical response of a mass defect in a one-dimensional non-loaded horizontal chain of identical spheres which interact via the nonlinear Hertz potential. Our experiments show that the interaction of a solitary wave with a light intruder excites localized mode. In agreement with dimensional analysis, we find that the frequency of localized oscillations exceeds the incident wave frequency spectrum and nonlinearly depends on the size of the intruder and on the incident wave strength. The absence of tensile stress between grains allows some gaps to open, which in turn induce a significant enhancement of the oscillations amplitude. We performed numerical simulations that precisely describe our observations without any adjusting parameters.Comment: 4 pages, 5 figures, submitted for publicatio

Economic analysis of fertilizer options for maize production in Tanzania

United States Agency for International Developmen

Landscape natural resources management using forage grasses and legume intercrops

United States Agency for International Developmen

Manejo de sistemas de produção de centeio visando a produção de forragem e de sementes para a agricultura familiar.

bitstream/item/78978/1/documento-319.pd

High frequency burst firing of granule cells ensures transmission at the parallel fiber to purkinje cell synapse at the cost of temporal coding.

Cerebellar granule cells (GrCs) convey information from mossy fibers (MFs) to Purkinje cells (PCs) via their parallel fibers (PFs). MF to GrC signaling allows transmission of frequencies up to 1 kHz and GrCs themselves can also fire bursts of action potentials with instantaneous frequencies up to 1 kHz. So far, in the scientific literature no evidence has been shown that these high-frequency bursts also exist in awake, behaving animals. More so, it remains to be shown whether such high-frequency bursts can transmit temporally coded information from MFs to PCs and/or whether these patterns of activity contribute to the spatiotemporal filtering properties of the GrC layer. Here, we show that, upon sensory stimulation in both un-anesthetized rabbits and mice, GrCs can show bursts that consist of tens of spikes at instantaneous frequencies over 800 Hz. In vitro recordings from individual GrC-PC pairs following high-frequency stimulation revealed an overall low initial release probability of ~0.17. Nevertheless, high-frequency burst activity induced a short-lived facilitation to ensure signaling within the first few spikes, which was rapidly followed by a reduction in transmitter release. The facilitation rate among individual GrC-PC pairs was heterogeneously distributed and could be classified as either "reluctant" or "responsive" according to their release characteristics. Despite the variety of efficacy at individual connections, grouped activity in GrCs resulted in a linear relationship between PC response and PF burst duration at frequencies up to 300 Hz allowing rate coding to persist at the network level. Together, these findings support the hypothesis that the cerebellar granular layer acts as a spatiotemporal filter between MF input and PC output (D'Angelo and De Zeeuw, 2009)

AN EXPLORATORY STUDY ON NUMBER OF CHILDREN DESIRED AND WHAT ACCOMPLISHED IN FAMILY SETTINGS

In any family settings, racing children is a big decision that requires serious self-reflecting and communication between couples. In African settings, there is usually a rift in the agreement of the number and the gender of children to be borne by couples; while the man prefers a male child, the wife may prefer a female child instead. The number of children by the couple also determine the kinds of education those children will eventually have later. To this effect, in this research work, we want to study the Man’s proposed and ac-tual number of children; the degree of association in the man’s decision using Quasi symmetry and Homogeneous Agreement model; how well some factors (Age, Religion, Family status, Occupation, Level of education and Ethnic group) influence the number of children; and to know the stopping rule for child bearing by the man. It was observed that 16.2% of the respondents had above the number of children proposed when they stopped bearing children, 21.5% of the respondents had below the number of children proposed when they stopped while 62.3% of the respondents had the exact number of children proposed when they eventually stopped bearing children. We observed that Age and Religion influence the number of children. We also observed that the probability ( p) of having at least one male child is 0.8019 based on the available data. The chance of any newly wedded couple ever having a male child at any trial follows a geometric distribution ( ) (0.8019)(0.1981) , 1,2,3 1 f x x x . Quasi symmetry model has a better fit for agreement measure than Homogeneous agreement model

EMPIRICAL STUDY OF PSYCHOTIC DISORDER PATIENTS IN NIGERIA

A study on psychotic disorder ailment was carried out in this research paper where the target population consists of all patients that has any of the following five psychotic disorders: Menial Brain Dysfunction (MBD); Schizophrenia; Vascular Dementia; Bipolar; and Insomnia. The sample consist of five hundred (500) psychotic patients that were selected from the entire number of psychotic patients in the hospital records (files) from January, 2010 to December, 2014. They were selected based on their peculiar ailments with symptoms of psychotic disorders. The main aim of this paper is to examine the possible existence of association among these psychotic disorders. The specific objectives are to: determine the demographic factors that influence the levels of each of these psychotic disorders; propose appropriate model for each psychotic disorder; and determine the level of correct classification using each of these models. We observed that there exist strong association among these psychotic disorders except for MBD and Vascular Demetria. Nearly all the demographic factors under consideration are one way or the other influence the levels of any psychotic disorder except divorce, injury, and genetic. The percentages of correct classification using each of the models proposed ranges between 70.8% and 91.2%

To vaccinate or not to vaccinate? Perspectives on HPV vaccination among girls, boys, and parents in the Netherlands: A Q-methodological study

Background: Despite the introduction of Human papillomavirus (HPV) vaccination in national immunization programs (NIPs), vaccination rates in most countries remain relatively low. An understanding of the reasons underlying decisions about whether to vaccinate is essential in order to promote wider spread of HPV vaccination. This is particularly important in relation to policies seeking to address shortfalls in current HPV campaigns. The aim of this study was to explore prevailing perspectives concerning HPV vaccination among girls, boys, and parents, and so to identify potential determinants of HPV vaccination decisions in these groups. Method: Perspectives were explored using Q-methodology. Forty-seven girls, 39 boys, and 107 parents in the Netherlands were asked to rank a comprehensive set of 35 statements, assembled based on the health belief model (HBM), according to their agreement with them. By-person factor analysis was used to identify common patterns in these rankings, which were interpreted as perspectives on HPV vaccination. These perspectives were further interpreted and described using data collected with interviews and open-ended questions. Results: The analysis revealed four perspectives: "prevention is better than cure," "fear of unknown side effects," "lack of information and awareness," and "my body, my choice." The first two perspectives and corresponding determinants of HPV vaccination decisions were coherent and distinct; the third and fourth perspectives were more ambiguous and, to some extent, incoherent, involving doubt and lack of awareness and information (perspective 3), and overconfidence (perspective 4). Conclusions: Given the aim of publically funded vaccination programs to minimize the spread of HPV infection and HPV-related disease and the concerns about current uptake levels, our results indicate that focus should be placed on increasing awareness and knowledge, in particular among those in a modifiable phase