The objective of this work was to develop a more and better understanding of the strength developing in clay-andesite fired brick. The purpose was to improve the quality of the clay bricks that are handmade in the sou...The objective of this work was to develop a more and better understanding of the strength developing in clay-andesite fired brick. The purpose was to improve the quality of the clay bricks that are handmade in the southern region of Ecuador to make them suitable for more widespread use in the local construction industry. To achieve our goal, we first physically, chemically, and mechanically characterized the “clayey” and “sandy” materials used in the fabrication of handmade bricks in the region. Second, the optimal mixture (OM): the optimal proportion between the amounts of “clayey” and “sandy” material was sought. Third, clay bricks were prepared using the OM, baked at 950°C, and characterized. In addition, bricks produced by regional artisans were characterized, and the results were compared with the results obtained for the bricks prepared using the OM. Our data reveal that the optimal mixture is 50% “clayey” material and 50% “sandy” material and that with this mixture, an average improvement in brick quality of 300% can be achieved;thus, the use of the OM makes it possible to expand the use of these bricks in the local construction industry and enables an environmentally friendly production process by reducing the intensive exploitation of regional clay deposits. This improvement is achieved by virtue of the anorthite enrichment that occurs in the solid solution, which results from the evolution of andesine. The anorthite contributes to the formation of a stronger matrix among the different grains of the material. Conditions are favorable for this enrichment process to occur when “sandy” materials with high contents of andesite, which is common in Ecuadorian soils, are used.展开更多
The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography （MSCT） and postopera...The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography （MSCT） and postoperative cone-beam computed tomography （CBCT） images. Second, the reliability and accuracy of this condylar volume quantification method was assessed. The mandibles of 20 patients （11 female and 9 male） who underwent bimaxillary surgery were semi-automatically extracted from MSCT/CBCT scans and rendered in 3D. The resulting condyles were spatially matched by using an anatomical landmark-based registration procedure. A standardized sphere was created around each condyle, and the condylar bone volume within this selected region of interest was automatically calculated. To investigate the reproducibility of the method, inter- and intra-observer reliability was calculated for assessments made by two experienced radiologists twice five months apart in a set of ten randomly selected patients. To test the accuracy of the bone segmentation, the inner and outer bone structures of one dry mandible, scanned according to the clinical set-up, were compared with the gold standard, micro-CT. Thirty-eight condyles showed a significant （P〈O.05） mean bone volume decrease of 26.4%_ 11.4% （502.9 mm3＋ 268.1 mm3）. No significant effects of side, sex or age were found. Good to excellent （ICC〉 0.6） intra- and inter-observer reliability was observed for both MSCT and CBCT. Moreover, the bone segmentation accuracy was less than one voxel （0.4 mm） for MSCT （0.3 mm __. 0.2 mm） and CBCT （0.4 mm _ 0.3 mm）, thus indicating the clinical potential of this method for objective follow-up in pathological condylar resorption.展开更多
For many control systems in real life, impulses and delays are intrinsic phenomena that do not modify their controllability. So we conjecture that under certain conditions the abrupt changes and delays as perturbation...For many control systems in real life, impulses and delays are intrinsic phenomena that do not modify their controllability. So we conjecture that under certain conditions the abrupt changes and delays as perturbations of a system do not destroy its controllability. There are many practical examples of impulsive control systems with delays, such as a chemical reactor system, a financial system with two state variables, the amount of money in a market and the savings rate of a central bank, and the growth of a population diffusing throughout its habitat modeled by a reaction-diffusion equation. In this paper we apply the Rothe’s Fixed Point Theorem to prove the interior approximate controllability of the following Benjamin Bona-Mohany(BBM) type equation with impulses and delay where and are constants, Ω is a domain in , ω is an open non-empty subset of Ω , denotes the characteristic function of the set ω , the distributed control , are continuous functions and the nonlinear functions are smooth enough functions satisfying some additional conditions.展开更多
The main objective of this research is to analyze deforestation in State Sinaloa during the period 1990-2014. For this, “deforestationhot-spot areas” were identified, by crossing maps of 1993 and 2011 at a 1:250,000...The main objective of this research is to analyze deforestation in State Sinaloa during the period 1990-2014. For this, “deforestationhot-spot areas” were identified, by crossing maps of 1993 and 2011 at a 1:250,000 scale with knowledge from environmental and forest experts from each region. Landsat images from 1990 and 2014 and Terra Amazon System were used to monitor the most critical hot spot area, applying Linear Spectral Mixture Analysis and Image Segmentation Ground Product. In order to generate the map deforestation year zero (1990), every segmented object of ground product was visually assigned to “Forest” and “No-Forest” categories. Therefore, gains and losses were interpreted for the map deforestation year one (2014). Those products were validated with the help of experts on the subject and applying a confusion matrix. Results obtained indicated that the highest forest loss was located in North-Central Sinaloa (hot spot area number two) by establishing the average annual rate of deforestation of 4741.90 ha/year with an average rate of 0.60%, being higher than the national average rate (0.37%). This result affects directlyon calculation of carbonfluxes at nationallevel.展开更多
Orthodox quantum mechanics is a highly successful theory despite its serious conceptual flaws. It renounces realism, implies a kind of action-at-a-distance and is incompatible with determinism. Orthodox quantum mechan...Orthodox quantum mechanics is a highly successful theory despite its serious conceptual flaws. It renounces realism, implies a kind of action-at-a-distance and is incompatible with determinism. Orthodox quantum mechanics states that Schrödinger’s equation (a deterministic law) governs spontaneous processes while measurement processes are ruled by probability laws. It is well established that time dependent perturbation theory must be used for solving problems involving time. In order to account for spontaneous processes, this last theory makes use of laws valid only when measurements are performed. This incoherence seems absent from the literature.展开更多
Background: The first 1000 days of life, including pregnancy and the first 2 years of age have been considered essential for an adequate development and growth. Several studies have stated that malnutrition during pre...Background: The first 1000 days of life, including pregnancy and the first 2 years of age have been considered essential for an adequate development and growth. Several studies have stated that malnutrition during pregnancy and not having a normal birth weight have negative impact on childhood and adulthood, and contribute to burden of disease. Adequate information on this matter provides the possibility for making recommendations on health and nutrition policies. Objective: The aim is to describe the nutritional status during the first 1000 days in four countries of Latin America: Colombia, Argentina, Chile and Brazil. Methods: The analysis consists of two complementary approaches: 1) An extensive search on published and gray literature and a critical analysis of secondary data bases was conducted in Colombia, Argentina, Chile and Brazil following a standardized methodology in 2013. Maternal and child nutritional status, breast feeding, nutri-tional deficiencies, and dietary habits during the first 1000 days were the variables of interest;2) Information gaps were identified, interviews to local experts from academia, government and hospitals were conducted to fill each of the countries information gap. Data was organized in an online data base called NutriPl@net. Results: Despite the inherent country differences, the nutritional challenges during the first 1000 days are similar. Obesity prevalence is increasing in pregnant women. Under weight remains a problem in all 4 countries, with the highest prevalence in Argentina. Over weight prevalence is highest in Chile and obesity prevalence in Brazil. Micronutrient deficiencies in pregnant women have been described, especially high for folic acid, iron, zinc, vitamins A, B6, B12, C, E and riboflavin. Moreover, in the region, anemia is the most common micronutrient deficiency during pregnancy. Gestational diabetes, hypertension, obesity and pre-eclampsia are major causes of maternal, perinatal and infant morbidity and mortality. Conclusions: In order to understand regional and country-specific needs, it is fundamental to collect standardized information related to the nutrition status during the first 1000 days. The low prevalence of exclusive breastfeeding and micronutrient deficiencies such as iron, zinc and vitamin A as risk factors for morbidity and mortality in children 0 - 2 years old is common and priority issues in the region. Persistence of anemia despite the use of fortified foods and supplementation remains a problem, and no complete data regarding sugar, sodium and fatty acids consumption and changes in the diet and habits before, during and after pregnancy are available. The gaps that are found to justify the need for further studies including population based surveys with standardized methodology that can warrant comparability.展开更多
Introduction: There is evidence that malnutrition during the first 1000 days of life contributes to the development of chronic diseases in adulthood and therefore may produce a lasting impact on the health of the popu...Introduction: There is evidence that malnutrition during the first 1000 days of life contributes to the development of chronic diseases in adulthood and therefore may produce a lasting impact on the health of the population. Colombia, like other middle-income countries suffers the double burden of malnutrition in pregnant women and children under 5 years. Also, chronic diseases have positioned within the leading causes of morbidity and mortality. Objective: The aim is to estimate the burden of disease of noncommunicable chronic diseases-NCD’s (hypertension, obesity, diabetes mellitus II) in adults attributable to nutritional risk factors (no-breastfeeding and low birthweight) in the period of 1000 days in Colombia. Methods: The population attributable fraction and the number of NCD’s (hypertension, diabetes mellitus II and obesity) cases due to the risk factors (low birthweight and no-breastfeeding) were estimated. Prevalences of NCD’s and risk factors of interest were taken from national health surveys. Effect measures (odds ratios/relative risks) of the associations 1—low birthweight and hypertension, diabetes mellitus II and 2—no-breastfeeding and obesity were obtained after a systematic literature search. Results: It was estimated that not receiving breastfeeding in the 1000 days could contribute up to 29.9% of all cases of obesity, equivalent to about 4,009,779 cases across the country. Low birth weight could contribute up to 2.1% of cases of hypertension in men and to 4.0% of cases in women, equivalent to 103.769 cases across the country. In addition, low birth weight could contribute to 6.3% of diabetes mellitus II cases, which is equivalent to 23.857 cases in the country. Conclusion: In Colombia, risk factors during the first 1000 days like not receiving breastfeeding and having low birth weight could contribute up to 4,113,549 cases of obesity, hypertension and diabetes mellitus II, with important implications for the health of the population and the Colombian health system.展开更多
The objective of this study is to determine the auditory gain, quality of life, audiological benefits, in bone-anchored hearing device users (BAHA). It is a retrospective and concurrent evaluation of thirty patients f...The objective of this study is to determine the auditory gain, quality of life, audiological benefits, in bone-anchored hearing device users (BAHA). It is a retrospective and concurrent evaluation of thirty patients fitted unilaterally and seven fitted bilaterally for at least six months. Patients were assessed with audiometric testing and application of Glasgow Benefit Inventory (GBI) and Abbreviated Profile of Hearing Aid Benefit (APHAB). Regarding sound-field pure audiometry results, we found a statistically significant gain in all frequencies using the bone-anchored device. APHAB scores showed statistically significant subjective audiological gains in all subscales except for the aversiveness subscale. GBI mean scores for all items in both groups were all above 3, suggesting quality of life improvement in conductive and mixed hearing loss patients. BP100 users showed a greater clinical gain in the APHAB global score and subscales compared with Divino users. In conclusion the BAHA provides significant auditory gain, subjective audiological benefits and improves quality of life in all BAHA users. This study shows a significant clinical and statistical benefit of BAHA measured by audiometric testing and by the APHAB and GBI questionnaires.展开更多
The nature, origin and propagation of the electric field are discussed for the first time on the basis of the presence of vibrating strings in the space and their self-excitation process. It is considered that the ele...The nature, origin and propagation of the electric field are discussed for the first time on the basis of the presence of vibrating strings in the space and their self-excitation process. It is considered that the electron is formed from strings and it has specific vibrational frequency. This excites the strings which are close by with the self-excitation process. This procedure which is continuous in the space according to the symmetry and vibrational energy in the form of waves spreads near the electron (or the charge particle), which behaves and carries energy known as electric field. In fact, the electron does not continuously emit energy in any form but induces (or excites) and organizes energy in a self-sustain vibrational form and extends in three dimensional space. Only on the basis of the presence of strings (vibrational energy), several electromagnetic phenomena have been explained in a consistent way. The vibrational nature of the electric field is also examined with the help of Stark effect and X-ray diffraction approach to support the present view.展开更多
文摘The objective of this work was to develop a more and better understanding of the strength developing in clay-andesite fired brick. The purpose was to improve the quality of the clay bricks that are handmade in the southern region of Ecuador to make them suitable for more widespread use in the local construction industry. To achieve our goal, we first physically, chemically, and mechanically characterized the “clayey” and “sandy” materials used in the fabrication of handmade bricks in the region. Second, the optimal mixture (OM): the optimal proportion between the amounts of “clayey” and “sandy” material was sought. Third, clay bricks were prepared using the OM, baked at 950°C, and characterized. In addition, bricks produced by regional artisans were characterized, and the results were compared with the results obtained for the bricks prepared using the OM. Our data reveal that the optimal mixture is 50% “clayey” material and 50% “sandy” material and that with this mixture, an average improvement in brick quality of 300% can be achieved;thus, the use of the OM makes it possible to expand the use of these bricks in the local construction industry and enables an environmentally friendly production process by reducing the intensive exploitation of regional clay deposits. This improvement is achieved by virtue of the anorthite enrichment that occurs in the solid solution, which results from the evolution of andesine. The anorthite contributes to the formation of a stronger matrix among the different grains of the material. Conditions are favorable for this enrichment process to occur when “sandy” materials with high contents of andesite, which is common in Ecuadorian soils, are used.
基金the Coordination for the Improvement of Higher Education Personnel(CAPES)programmeScience without borders from Brazilian governmentthe Research Foundation Flanders(FWO)from Flemish government for the fellowship support
文摘The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography （MSCT） and postoperative cone-beam computed tomography （CBCT） images. Second, the reliability and accuracy of this condylar volume quantification method was assessed. The mandibles of 20 patients （11 female and 9 male） who underwent bimaxillary surgery were semi-automatically extracted from MSCT/CBCT scans and rendered in 3D. The resulting condyles were spatially matched by using an anatomical landmark-based registration procedure. A standardized sphere was created around each condyle, and the condylar bone volume within this selected region of interest was automatically calculated. To investigate the reproducibility of the method, inter- and intra-observer reliability was calculated for assessments made by two experienced radiologists twice five months apart in a set of ten randomly selected patients. To test the accuracy of the bone segmentation, the inner and outer bone structures of one dry mandible, scanned according to the clinical set-up, were compared with the gold standard, micro-CT. Thirty-eight condyles showed a significant （P〈O.05） mean bone volume decrease of 26.4%_ 11.4% （502.9 mm3＋ 268.1 mm3）. No significant effects of side, sex or age were found. Good to excellent （ICC〉 0.6） intra- and inter-observer reliability was observed for both MSCT and CBCT. Moreover, the bone segmentation accuracy was less than one voxel （0.4 mm） for MSCT （0.3 mm __. 0.2 mm） and CBCT （0.4 mm _ 0.3 mm）, thus indicating the clinical potential of this method for objective follow-up in pathological condylar resorption.
文摘For many control systems in real life, impulses and delays are intrinsic phenomena that do not modify their controllability. So we conjecture that under certain conditions the abrupt changes and delays as perturbations of a system do not destroy its controllability. There are many practical examples of impulsive control systems with delays, such as a chemical reactor system, a financial system with two state variables, the amount of money in a market and the savings rate of a central bank, and the growth of a population diffusing throughout its habitat modeled by a reaction-diffusion equation. In this paper we apply the Rothe’s Fixed Point Theorem to prove the interior approximate controllability of the following Benjamin Bona-Mohany(BBM) type equation with impulses and delay where and are constants, Ω is a domain in , ω is an open non-empty subset of Ω , denotes the characteristic function of the set ω , the distributed control , are continuous functions and the nonlinear functions are smooth enough functions satisfying some additional conditions.
文摘The main objective of this research is to analyze deforestation in State Sinaloa during the period 1990-2014. For this, “deforestationhot-spot areas” were identified, by crossing maps of 1993 and 2011 at a 1:250,000 scale with knowledge from environmental and forest experts from each region. Landsat images from 1990 and 2014 and Terra Amazon System were used to monitor the most critical hot spot area, applying Linear Spectral Mixture Analysis and Image Segmentation Ground Product. In order to generate the map deforestation year zero (1990), every segmented object of ground product was visually assigned to “Forest” and “No-Forest” categories. Therefore, gains and losses were interpreted for the map deforestation year one (2014). Those products were validated with the help of experts on the subject and applying a confusion matrix. Results obtained indicated that the highest forest loss was located in North-Central Sinaloa (hot spot area number two) by establishing the average annual rate of deforestation of 4741.90 ha/year with an average rate of 0.60%, being higher than the national average rate (0.37%). This result affects directlyon calculation of carbonfluxes at nationallevel.
文摘Orthodox quantum mechanics is a highly successful theory despite its serious conceptual flaws. It renounces realism, implies a kind of action-at-a-distance and is incompatible with determinism. Orthodox quantum mechanics states that Schrödinger’s equation (a deterministic law) governs spontaneous processes while measurement processes are ruled by probability laws. It is well established that time dependent perturbation theory must be used for solving problems involving time. In order to account for spontaneous processes, this last theory makes use of laws valid only when measurements are performed. This incoherence seems absent from the literature.
文摘Background: The first 1000 days of life, including pregnancy and the first 2 years of age have been considered essential for an adequate development and growth. Several studies have stated that malnutrition during pregnancy and not having a normal birth weight have negative impact on childhood and adulthood, and contribute to burden of disease. Adequate information on this matter provides the possibility for making recommendations on health and nutrition policies. Objective: The aim is to describe the nutritional status during the first 1000 days in four countries of Latin America: Colombia, Argentina, Chile and Brazil. Methods: The analysis consists of two complementary approaches: 1) An extensive search on published and gray literature and a critical analysis of secondary data bases was conducted in Colombia, Argentina, Chile and Brazil following a standardized methodology in 2013. Maternal and child nutritional status, breast feeding, nutri-tional deficiencies, and dietary habits during the first 1000 days were the variables of interest;2) Information gaps were identified, interviews to local experts from academia, government and hospitals were conducted to fill each of the countries information gap. Data was organized in an online data base called NutriPl@net. Results: Despite the inherent country differences, the nutritional challenges during the first 1000 days are similar. Obesity prevalence is increasing in pregnant women. Under weight remains a problem in all 4 countries, with the highest prevalence in Argentina. Over weight prevalence is highest in Chile and obesity prevalence in Brazil. Micronutrient deficiencies in pregnant women have been described, especially high for folic acid, iron, zinc, vitamins A, B6, B12, C, E and riboflavin. Moreover, in the region, anemia is the most common micronutrient deficiency during pregnancy. Gestational diabetes, hypertension, obesity and pre-eclampsia are major causes of maternal, perinatal and infant morbidity and mortality. Conclusions: In order to understand regional and country-specific needs, it is fundamental to collect standardized information related to the nutrition status during the first 1000 days. The low prevalence of exclusive breastfeeding and micronutrient deficiencies such as iron, zinc and vitamin A as risk factors for morbidity and mortality in children 0 - 2 years old is common and priority issues in the region. Persistence of anemia despite the use of fortified foods and supplementation remains a problem, and no complete data regarding sugar, sodium and fatty acids consumption and changes in the diet and habits before, during and after pregnancy are available. The gaps that are found to justify the need for further studies including population based surveys with standardized methodology that can warrant comparability.
文摘Introduction: There is evidence that malnutrition during the first 1000 days of life contributes to the development of chronic diseases in adulthood and therefore may produce a lasting impact on the health of the population. Colombia, like other middle-income countries suffers the double burden of malnutrition in pregnant women and children under 5 years. Also, chronic diseases have positioned within the leading causes of morbidity and mortality. Objective: The aim is to estimate the burden of disease of noncommunicable chronic diseases-NCD’s (hypertension, obesity, diabetes mellitus II) in adults attributable to nutritional risk factors (no-breastfeeding and low birthweight) in the period of 1000 days in Colombia. Methods: The population attributable fraction and the number of NCD’s (hypertension, diabetes mellitus II and obesity) cases due to the risk factors (low birthweight and no-breastfeeding) were estimated. Prevalences of NCD’s and risk factors of interest were taken from national health surveys. Effect measures (odds ratios/relative risks) of the associations 1—low birthweight and hypertension, diabetes mellitus II and 2—no-breastfeeding and obesity were obtained after a systematic literature search. Results: It was estimated that not receiving breastfeeding in the 1000 days could contribute up to 29.9% of all cases of obesity, equivalent to about 4,009,779 cases across the country. Low birth weight could contribute up to 2.1% of cases of hypertension in men and to 4.0% of cases in women, equivalent to 103.769 cases across the country. In addition, low birth weight could contribute to 6.3% of diabetes mellitus II cases, which is equivalent to 23.857 cases in the country. Conclusion: In Colombia, risk factors during the first 1000 days like not receiving breastfeeding and having low birth weight could contribute up to 4,113,549 cases of obesity, hypertension and diabetes mellitus II, with important implications for the health of the population and the Colombian health system.
文摘The objective of this study is to determine the auditory gain, quality of life, audiological benefits, in bone-anchored hearing device users (BAHA). It is a retrospective and concurrent evaluation of thirty patients fitted unilaterally and seven fitted bilaterally for at least six months. Patients were assessed with audiometric testing and application of Glasgow Benefit Inventory (GBI) and Abbreviated Profile of Hearing Aid Benefit (APHAB). Regarding sound-field pure audiometry results, we found a statistically significant gain in all frequencies using the bone-anchored device. APHAB scores showed statistically significant subjective audiological gains in all subscales except for the aversiveness subscale. GBI mean scores for all items in both groups were all above 3, suggesting quality of life improvement in conductive and mixed hearing loss patients. BP100 users showed a greater clinical gain in the APHAB global score and subscales compared with Divino users. In conclusion the BAHA provides significant auditory gain, subjective audiological benefits and improves quality of life in all BAHA users. This study shows a significant clinical and statistical benefit of BAHA measured by audiometric testing and by the APHAB and GBI questionnaires.
文摘The nature, origin and propagation of the electric field are discussed for the first time on the basis of the presence of vibrating strings in the space and their self-excitation process. It is considered that the electron is formed from strings and it has specific vibrational frequency. This excites the strings which are close by with the self-excitation process. This procedure which is continuous in the space according to the symmetry and vibrational energy in the form of waves spreads near the electron (or the charge particle), which behaves and carries energy known as electric field. In fact, the electron does not continuously emit energy in any form but induces (or excites) and organizes energy in a self-sustain vibrational form and extends in three dimensional space. Only on the basis of the presence of strings (vibrational energy), several electromagnetic phenomena have been explained in a consistent way. The vibrational nature of the electric field is also examined with the help of Stark effect and X-ray diffraction approach to support the present view.
