Introduction: Low birth weight (<2500 g) is one of the most important indicators to monitor progress in maternal, perinatal and child health. Materials and methods: Descriptive, analytical- correlational study with a quantitative approach. 1410 cases of newborns with low birth weight, reported in the Public Health Epidemiological Surveillance System (SIVIGILA) of the Department of Health Development, in the department of C�rdoba, Colombia, were analyzed. For the analysis, the R statistical package and frequency tables were used. Results: 35% of the mothers were between the ages of 17-21 and 55% of them reside in municipal capitals. 92% had various trades as their occupation, 82% belong to stratum 1, 2% integrate the migrant population and 66% have a secondary educational level. On the other hand, 47% of the children reached 37 weeks of gestation and 94% of them were classified as low birth weight. Discussion: These results agree with those of other authors who determined that socioeconomic factors influence low birth weight. Conclusions: The sociodemographic characteristics of the mother are determining factors for low birth weight.
The development of management models for identification of optimal operating policies for reservoirs spans more than four decades of research. In an uncertain environment, where climatic factors such as streamflow are stochastic, the returns from reservoir releases defined by the optimal policy are uncertain. Furthermore, the consequences of release decisions cannot be fully realized until future unknown events occur. In the present study, Stochastic Dynamic Programming (SDP) model is developed to obtain optimal operating policy for Klang Gate reservoir, Malaysia. Historic rainfall data is used to calculate the inflow which considers the stochastic nature of inflow in the form of inflow transition probability matrices. The proposed (SDP) is developed to provide the optimal release policy on monthly basis from Klang Gate, Malaysia. Three different performance criterions have been examined by simulating the Klang gate with respect to the policy derived by SDP. The results showed that high level of reliability and reasonable level of resilience, vulnerability and accordingly minimizing the deviation between release and demand have been achieved.
Urbanization is a leading cause of habitat loss and fragmentation, posing significant threats to native plant biodiversity in tropical ecosystems. This study investigates the effects of urban expansion on the diversity and distribution of native plant species in selected regions of Southeast Asia. We conducted comprehensive field surveys and employed remote sensing techniques to assess the extent of urban encroachment and its impact on plant communities. Our findings reveal a marked decline in native plant species richness in urbanized areas, with significant implications for ecosystem services and conservation strategies. The study emphasizes the need for sustainable urban planning and habitat restoration efforts to mitigate biodiversity loss.
The objective of the paper is to analyze and compare the performances of the axial flux permanent magnet brushless dc (AFPM BLDC)motor with single-phase winding and two-phase winding. To study the motor operation, a mathematical dynamic model has been proposed for each of the motor with different winding, which became the basis for simulations that were performed using MATLAB/SIMULINK software package. The calculation results show that the two-phase motor version develops more smooth torque and reaches higher efficiency than the single-phase version. However the advantage of using a single-phase version is simpler and cheaper converter which the motor is supplied from. This implicates of using this type of motor for fans and pumps where torque ripple is not the subject, while the two-phase motor can be applied where more smooth torque is required. Both motors are supplied from inverter whose structure depends on the type of winding. Since there were voltage type inverters, the switching angle of transistors had significance on the motor performance. This influence was studied for both motors.
Presently, the construction industry has shown considerable consciousness in utilizing lightweight foamcrete as a building material. The demand of lightweight foamcrete is becoming higher now where this material has increased many folds in recent years due to its intrinsic economies and advantages over conventional concrete in a range of structural and semi-structural applications. The major specialties of lightweight foamcrete are its excellent thermal conductivity, low self-weight, high impact resistance and good freeze thaw resistance. The aim of this experimental study is to investigate the thermal conductivity property of lightweight foamcrete with various densities. The main parameters that will be considered are density of lightweight foamcrete, the void size and porosity. The lightweight foamcrete samples are made with constant water-cement ratio of 0.5 and cement-sand ratio of 2:1. According to experimental results, lower densities lightweight foamcrete transforms to lower thermal conductivity values. Meanwhile, the density of lightweight foamcrete is controlled by the porosity where lower densities indicate larger porosity values. For this reason, thermal conductivity of lightweight foamcrete changes significantly with the porosity because air is the poorest conductor in comparison to solid and liquid owing its molecular constitution. The measured values of thermal conductivity should provide a useful database for evaluating the thermal performance of lightweight foamcrete structures.
In this paper we investigated the long run relationship between formal education expenditures and economic growth and also their influences on each other in Iran and for years 1979-2008. In this purpose vector autoregressive model (VAR) has been used. First, stable of variables by the use of Dickey-fuller test has been examined. Next, analysis of Johnson test for considering the convergence among variables has been used. The results of this research show that the variables Employment divided by population, The initial level of per capita production of employers, employment, physical capital, human capital (Primary and secondary as a percentage of GDP) and human capital (advance education as a percentage of GDP) have a positive effect on real product in Iran.
Biodiversity is a key indicator of ecosystem health and function. Understanding species distribution and diversity patterns is vital for conservation efforts. This study introduces a novel framework utilizing clustering ensemble methods and swarm intelligence, specifically the Ant Colony Optimization algorithm, to analyze biodiversity data. By integrating data from various ecological sources, the ensemble approach enhances the robustness of biodiversity assessments. Experimental results from diverse ecosystems demonstrate the effectiveness of this method in providing insights into species diversity and distribution patterns.
In this paper, equivalence relation and long term of seven variables: Gross domestic product growth rate, labor force growth rate, private investment, public investment in transportation infrastructure, the difference between public investment and public investment in transportation infrastructure, growth rate of export of goods and services and growth rate of imports of goods and services and also their influences on each other in Iran for years 1973 to 2008 have been analyzed. For this purpose, vector autoregressive model (VAR) has been used. The First stability of variables by the use of dickey-fuller test has been examined. Next, analysis of Johnson test for considering the convergence among seven variables has been used. The results of this research show that variables of labor force growth rate, the difference between public investment and public investment in transportation infrastructure and growth rate of imports of goods and services have negative effect on economic growth and variables of private investment, public investment in transportation infrastructure and growth rate of export of goods and services has a positive effect on economic growth.
