International Annals of Science
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Integer-valued Time Series Model via Generalized Linear Models Technique of Estimation
Get PDFThe paper authenticated the need for separate positive integer time series model(s). This was done from the standpoint of a proposal for both mixtures of continuous and discrete time series models. Positive integer time series data are time series data subjected to a number of events per constant interval of time that relatedly fits into the analogy of conditional mean and variance which depends on immediate past observations. This includes dependency among observations that can be best described by Generalized Autoregressive Conditional Heteroscedasticity (GARCH) model with Poisson distributed error term due to its positive integer defined range of values. As a result, an integer GARCH model with Poisson distributed error term was formed in this paper and called Integer Generalized Autoregressive Conditional Heteroscedasticity (INGARCH). Iterative Reweighted Least Square (IRLS) parameter estimation technique type of the Generalized Linear Models (GLM) was adopted to estimate parameters of the two spilt models; Linear and Log-linear INGARCH models deduced from the identity link function and logarithmic link function, respectively. This resulted from the log-likelihood function generated from the GLM via the random component that follows a Poisson distribution. A study of monthly successful bids of auction from 2003 to 2015 was carried out. The Probabilistic Integral Transformation (PIT) and scoring rule pinpointed the uniformity of the linear INGARCH than that of the log-linear INGARCH in describing first order autocorrelation, serial dependence and positive conditional effects among covariates based on the immediate past. The linear INGARCH model outperformed the log-linear INGARCH model with (AIC = 10514.47, BIC = 10545.01, QIC = 34128.56) and (AIC = 37588.83, BIC = 37614.28, QIC = 37587.3), respectively
Cryptosporidium in the Philippines
Get PDFThis short review provides an overview regarding the research findings on the occurrence of Cryptosporidium in the Philippines. It seeks to set conjecture about its possible role on the increasing waterborne disease incidences in the country. Intensive search of journal articles was done among major databases, online. The first report of Cryptosporidium infection in the country was in 1985. Past more than 30 years, Cryptosporidium is not yet well-understood in the Philippines, but an increasing research interest has been observed among Filipinos in the past few years. Recently, waterborne transmission of the infection appeared in the studies to be more potent than zoonotic and person-to-person transmissions. An improvement on the detection methods was also observed, giving an improved knowledge on the molecular diversity of Cryptosporidium in the country. Despite these improvements, the paucity of the data regarding the impact of Cryptosporidium to the public health in the Philippines is still apparent. One Health approach is recommended to fully understand the interconnections between human, animal, and environment as reservoirs of the infective stage of the parasite. Dedication of the researchers in understanding their geographical distribution, molecular diversity, and environmental and climatic behaviour will eventually uncover the public health implications of Cryptosporidium in the country
Toll-like Receptors Regulate MIF Expression in Benign Lymphoepithelial Lesion of the Lacrimal Gland
Get PDFDespite a perpetual increase in the prevalence of benign lymphoepithelial lesion, data on the mechanisms governing its pathogenesis are still missing. Thus, we aimed in the present study to evaluate whether TLRs could regulate the expression of the pleiotropic pro-inflammatory and tumor-related cytokine MIF in BLEL. Using gene expression profiling and protein expression analysis methods, we found that TLRs were overexpressed and that their signaling pathways were activated in BLEL. We have also confirmed in tissues biopsies, the overexpression of MIF reported previously in plasma of BLEL specimen. The analysis of the TLR7/8 impact on the expression of MIF in BLEL primary cells showed that when activated, TLR7/8 stimulate mainly BLEL lymphocytes to release MIF but not the fibroblast-like cells. No significant change was observed when MIF expression was investigated at the transcriptional level 24h post TLR7/8 activation. Taken together, these data suggest that TLR7 and TLR8 are activated in BLEL and may induce a cell type-dependent regulation of MIF secretion and expression
Induction of Somatic Embryogenesis from Cocoa Farmer Field Collection of ICT - Peru
Get PDFTo induce the formation of embryogenic structures from staminodes, in 10 cocoa genotypes (Theobroma cacao L.) from the ICT Collection, the influence of the combination of two growth hormones (2,4 Dichlorophenoxyacetic 2,4 -D and Thidiazuron TDZ) was studied. Floral explants (staminodes), were induced to form calli in a culture medium supplemented with modified DKW mineral salts. At 12 days of implantation in the culture medium, the explants responded to the callus induction with a bulge at the base, covering the explants totally with callus at 40 days of culture. Embryogenic expression was shown at 52 days of culture. The genotypes ICT-2161 and ICT-2142 shows the highest percentage of somatic embryogenesis. Four types of callus, fine crystalline, thick crystalline, semi-compact and compact were observed. In addition, a clear organogenic response was observed when roots were formed from the callus generated
Mean Rate of Gully Head Advancement in Edo State, Nigeria
Get PDFThe issue of gully erosion is of major concern in Nigeria. The study was carried out in Edo state, Southern Nigeria. Edo State was chosen as the study area due to the fact that the magnitude of gully erosion has resulted in the loss of lives and properties, destruction of arable lands and wastage of large areas of usable land. In this study, an effort was made to identify the major gully sites in the area and determined the mean rate of gully head advancement. The result revealed that gullies in Edo North had mean rate of head advancement of 80.30 meters per a year, Edo South 52.03 meters per a year and Edo Central is 17.80 meters per year
Effect of Biochar Application and Arbuscular Mycorrhizal Inoculation on Root Colonization and Soil Chemical Properties
Get PDFField experiment was carried out in 2013 and 2014 to investigate the effects of biochar application and arbuscular mycorrhizal (AM) inoculation on AM root colonization and selected soil chemical properties of two tomato genotypes. The experiment was laid out in a split-split plot arrangement with two tomato genotypes in the main plots, five rates of biochar applied in the sub plots and two levels of AMF inoculation in the sub-sub plots. Data were subjected to analysis of variance and significant means separated using Duncan’s Multiple Range Test (P<0.05). The results indicated that mycorrhizal inoculation had little or no influence on AM root colonization, soil organic carbon, soil pH and available phosphorus. Application of 20 t ha-1 of biochar significantly increased (P< 0.05) soil pH and available P compared with the control while 10 t ha-1 and 15 t ha-1 of biochar produced higher organic carbon than other rates. In conclusion, biochar increased soil pH but was not high enough as to have detrimental effect on soil properties. It is, therefore, recommended that biochar with very strongly alkaline pH should only be used in soil with low pH for improvement of soil chemical and AM root colonization
Forward Time Centered Space Scheme for the Solution of Transport Equation
Get PDFTransport phenomenon is central for understanding many procedures in numerous sciences, transport phenomena can be described by the partial differential equation. Forward Time Centered Space scheme give ample numerical solutions of the transport equation. In this paper, we apply Forward Time Centered Space scheme to solve a non-trivial transport problem using different step sizes of time (t) and space (x). We use MATLAB software to get the numerical results. The numerical simulation presents that the FTCS scheme is more stable and closer to the exact solution when we decrease step sizes of t, x and more and more
An Insight into the Solar Dynamo Theory
Get PDFThe Sun manifests its magnetic field in form of the solar activities, being observed on the surface of the Sun. The dynamo action is responsible for the evolution of the magnetic field in the Sun. The present article aims to present an overview of the studies have been carried on the theory and modelling of the solar dynamo. The article describes the alpha-omega dynamo model. Generally, the dynamo model involves the cyclic conversion between the poloidal field and the toroidal field. In case of alpha-omega dynamo model, the strong differential rotation generates a toroidal field near the base of the convection zone. On the other hand, the turbulent helicity leads to the generation of the poloidal field near the surface. The turbulent diffusion and the meridional circulation are considered as the two important flux transport agents in this model. The article briefly describes the theory of solar dynamo and mean field dynamo model
Occlusion and Severe Stenosis Identification in Arterial System
Get PDFIn the present work, an appropriate method allowing accurate determinations of the position of arterial severe stenosis and full obstruction in the arterial vessels has been developed. This method requires measurements of instantaneous flow velocity and arterial radius at two sites in the arterial tree. The accuracy of the present method for different hemodynamic conditions has been examined. Numerical simulation and Womersley theory of the present model have been investigated. Realistic condition of hemodynamic parameters with noise has been simulated. Also, the effects of stenosis severities and the sites of occlusion have been considered. The results of present work show the location of stenosis and occlusion can be obtained by reasonable accuracy
Delineation of Hydrothermally Altered Zones that Favour Gold Mineralization in Isanlu Area, Nigeria Using Aeroradiometric Data
Get PDFAeroradiometric data set of Isanlu sheet 225 (1:100,000) has been acquired with a view to analyze and interpret for the delineation of hydrothermally altered zones that favour gold mineralization. The acquired aero-radiometric data was subjected to filtering algorithm and enhancement techniques such as shaded relief enhancement, elemental ratio enhancement using Geosoft Oasis Montaj Software. Moreover, Golden Software Surfer was used to identify and present the revealed hydrothermally altered zones. The interpretation of the aero data set has enhanced the delineation of eight hydrothermally altered zones. Therefore, the areas that are hydrothermally altered are potential sites for gold mineralization, such as areas around Odogbe and Okolom in the north-central portion of the study area. Similarly, regions around Egbe in the western edge are suspected to be mineralized zones. Results obtained in this research study have shown that mapping of hydrothermally altered zones that favour gold mineralization is feasible even without the actual physical contact and visitation to the area. The research suggests that this method of delineation may compliment other geophysical exploration technique for possible gold bearing zones of an area. Moreover, due to the non-invasive nature of the method, large areas of space may be mapped within a limited time. Areas that are non-accessible to ground geophysical exploration due to various factors can also be studied