Chaotic Observer-based Synchronization Under Information Constraints

Limit possibilities of observer-based synchronization systems under information constraints (limited information capacity of the coupling channel) are evaluated. We give theoretical analysis for multi-dimensional drive-response systems represented in the Lurie form (linear part plus nonlinearity depending only on measurable outputs). It is shown that the upper bound of the limit synchronization error (LSE) is proportional to the upper bound of the transmission error. As a consequence, the upper and lower bounds of LSE are proportional to the maximum rate of the coupling signal and inversely proportional to the information transmission rate (channel capacity). Optimality of the binary coding for coders with one-step memory is established. The results are applied to synchronization of two chaotic Chua systems coupled via a channel with limited capacity.Comment: 7 pages, 6 figures, 27 reference

ANALYSIS OF REPETITION RATES IN SECONDARY SCHOOLS IN ANAMBRA STATE, NIGERIA

In every state of Nigeria Anambra State inclusive, one major problem confronting secondary education is that the total number of students who enroll into schools do not complete the duration of their course or education as at the stipulated time due to many reasonsincluding class failures. This situation is considered as repetition. Repetition constitutes a management problem and drains the limited resources available to education. In view of this, this study was carried out to analyse the rate of repetition in secondary schools in Anambra state, Nigeria. Three research questions guided the study.The study adopted the descriptive survey research design. The population was 781 secondary schools comprising 257 public and 524 private from the six education zones in the state. The sample was 235 secondary schools comprising 78 public and 158 private drawn using stratified and simple random sampling techniques. Data were collected through the use of a researcher designed inventory proforma titled Analysis of Repetition Rate in Secondary Schools in Anambra State. The Proforma was divided into two sections; A and B. Section A contains biodata of the schools while section B contains items specifying enrolment, promotion, and repetition. The instrument was validated by three experts who are lecturers in the Faculty of Education, Nnamdi Azikiwe University. A reliability coefficient of 0.83 for the instrument was obtained using Cronbach Alpha for the test of internal consistency. The researcher used ‘on the spot’ method to collect data from the respondents. All the 235copie of the instrument administered were successfully retrieved after completion and were used for data analysis. Data were analyzed using frequency counts, simple percentage scores and the results also expressed in bar graphs. The study revealed that there was low repetition rate in private secondary schools compared to public secondary schools, and that repetition rate was highest in SS1. It was also found out that Otuocha zone has the highest rate of repetition compared to other zones. Based on the findings, it was recommended among others that there should be increased funding to education and that provision of facilities in the schools should be improved

Taxonomy and ecology of Mentzelia mollis Peck and related species

A study was made to clarify the relationships of Mentzelia mollis Peck and two poorly understood taxa of Mentzelia (Loasaceae) to the other members of the genus, its sections, and its subsections, and to describe the general ecology of each taxon. Within the genus, the section Trachyphytum is characterized by pendulous seeds, an annual habit, and placentae that do not expand as the seeds mature. The section is further divided into three subsections on the basis of width of filaments and shape and surface texture of the seeds. Seven populations of M. mollis were found, all growing in a floristically depauperate community on greenish clay derived from the Sucker Creek Formation and all within the Succor Creek drainage of Malheur County, Oregon and Owyhee County, Idaho. The Leslie Gulch Mentzelia occurs only in Leslie Gulch, west of Succor Creek, at the base of talus slopes of the same Sucker Creek Formation. The Colorado Mentzelia has been found only in Colorado and Utah, near the border between the two states. Morphological and cytological comparisons of M. mollis and the Leslie Gulch Mentzelia show differences in floral structure, branching pattern, leaf shape, seed size and shape, and ploidy level. Mentzelia mollis is a tetraploid (n=18) and the Leslie Gulch Mentzelia is an octoploid (n=36). Both have narrow filaments, pendulous seeds, and placentae which do not expand as the seeds mature. Comparison of the Colorado Mentzelia with M. mollis shows similar branching pattern and seed size, but differences in the seed surface detail and in floral structure. The scanning electron microscope was utilized to compare seed shape and surface detail of these three taxa with that of three other species of section Trachyphytum. Both M. mollis and the Leslie Gulch Mentzelia have flowers which open about 2:30 p.m. and close after dark, and both are visited by the same Bombyliid-type insects in early evening. Both tolerate extraordinarily high concentrations of potassium, sodium, and calcium, as well as high soil surface and air temperatures. Placement of all three taxa in section Trachyphytum was made on the basis of relative placental growth and annual habit. Seed shape and surface detail justified their placement in subsection Trachyphyta. Morphological considerations and ploidy level seemed sufficient evidence to describe the Leslie Gulch Mentzelia as a new species, Mentzelia packardiae Glad; and morphological differences and geographical separation indicated that the Colorado Mentzelia should be similarly handled. It was described as Mentzelia thompsonii Glad. An existing key was adapted to include all three species. Speculation concerning possible origins of M. mollis and M. packardiae leads to the hypothesis that M. mollis is a relic which survived the climatic and geological fluctuations of the past. Its origin is considered in relation to its being a member of a mature polyploid complex. It is also considered possible that there may be some relationship between M. mollis and the possibly younger M packardiae. Both species are edaphic endemics, and their evolution is briefly considered in that respect

Optometric extension program: 1991 bibliography of near lenses and vision training research

Optometric extension program: 1991 bibliography of near lenses and vision training researc

Treatment of intracerebral haemorrhage with tranexamic acid : A review of current evidence and ongoing trials

Peer reviewe

Sex-stratified genome-wide association meta-analysis of major depressive disorder

There are striking sex differences in the prevalence and symptomology of Major Depressive Disorder. Here, we conduct the largest sex-stratified genome wide association and genotype-by-sex interaction meta-analyses of Major Depressive Disorder to date (Females: 130,471 cases, 159,521 controls. Males: 64,805 cases, 132,185 controls). We identify 16 and eight independent genome-wide significant variants in females and males, respectively, including one novel variant on the X chromosome. Major Depressive Disorder in females and males shows substantial genetic overlap with a large proportion of variants displaying similar effect sizes across sexes. However, we also provide evidence for a higher burden of genetic risk in females which could be due to female-specific variants. Additionally, sex-specific pleiotropic effects may contribute to the higher prevalence of metabolic symptoms in females with Major Depressive Disorder. These findings underscore the importance of considering sex-specific genetic architectures in the study of health conditions, including Major Depressive Disorder, paving the way for more targeted treatment strategies

Thomas Decomposition and Nonlinear Control Systems

This paper applies the Thomas decomposition technique to nonlinear control systems, in particular to the study of the dependence of the system behavior on parameters. Thomas' algorithm is a symbolic method which splits a given system of nonlinear partial differential equations into a finite family of so-called simple systems which are formally integrable and define a partition of the solution set of the original differential system. Different simple systems of a Thomas decomposition describe different structural behavior of the control system in general. The paper gives an introduction to the Thomas decomposition method and shows how notions such as invertibility, observability and flat outputs can be studied. A Maple implementation of Thomas' algorithm is used to illustrate the techniques on explicit examples

Characterisation of CART-containing neurons and cells in the porcine pancreas, gastro-intestinal tract, adrenal and thyroid glands

<p>Abstract</p> <p>Background</p> <p>The peptide CART is widely expressed in central and peripheral neurons, as well as in endocrine cells. Known peripheral sites of expression include the gastrointestinal (GI) tract, the pancreas, and the adrenal glands. In rodent pancreas CART is expressed both in islet endocrine cells and in nerve fibers, some of which innervate the islets. Recent data show that CART is a regulator of islet hormone secretion, and that CART null mutant mice have islet dysfunction. CART also effects GI motility, mainly via central routes. In addition, CART participates in the regulation of the hypothalamus-pituitary-adrenal-axis. We investigated CART expression in porcine pancreas, GI-tract, adrenal glands, and thyroid gland using immunocytochemistry.</p> <p>Results</p> <p>CART immunoreactive (IR) nerve cell bodies and fibers were numerous in pancreatic and enteric ganglia. The majority of these were also VIP IR. The finding of intrinsic CART containing neurons indicates that pancreatic and GI CART IR nerve fibers have an intrinsic origin. No CART IR endocrine cells were detected in the pancreas or in the GI tract. The adrenal medulla harboured numerous CART IR endocrine cells, most of which were adrenaline producing. In addition CART IR fibers were frequently seen in the adrenal cortex and capsule. The capsule also contained CART IR nerve cell bodies. The majority of the adrenal CART IR neuronal elements were also VIP IR. CART IR was also seen in a substantial proportion of the C-cells in the thyroid gland. The majority of these cells were also somatostatin IR, and/or 5-HT IR, and/or VIP IR.</p> <p>Conclusion</p> <p>CART is a major neuropeptide in intrinsic neurons of the porcine GI-tract and pancreas, a major constituent of adrenaline producing adrenomedullary cells, and a novel peptide of the thyroid C-cells. CART is suggested to be a regulatory peptide in the porcine pancreas, GI-tract, adrenal gland and thyroid.</p