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1.
Toxics ; 12(6)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38922106

RESUMO

Sugarcane production has been linked to the release of heavy metals and metalloids (HM/MTs) into the environment, raising concerns about potential health risks. This study aimed to assess the levels of 19 HM/MTs in children living near a sugarcane mill through a pilot biomonitoring investigation. We investigated sex-related differences in these element levels and their correlations. A cross-sectional study was conducted, analyzing data from 20 children in the latter part of 2023. Spearman correlation coefficients with 95% confidence intervals (CIs) were used to assess the relationships between urinary HM/MT levels. Detectable levels of 17 out of the 19 HM/MTs were found across the entire study sample, with arsenic and copper detectable in 95% of the children. Titanium exhibited higher levels in boys compared to girls (p = 0.017). We identified 56 statistically significant correlations, with 51 of them being positive, while the remaining coefficients indicated negative relationships. This study characterized HM/MT levels in school-aged children residing near a sugarcane mill through a pilot biomonitoring investigation. Further research employing larger sample sizes and longitudinal assessments would enhance our understanding of the dynamics and health impacts of HM/MT exposure in this vulnerable population.

2.
Revista Digital de Postgrado ; 13(1): 387, abr. 2024. ilus
Artigo em Espanhol | LILACS, LIVECS | ID: biblio-1554973

RESUMO

Múltiples estrategias terapéuticas se han desarrollado con el objetivo de optimizar el tratamiento del cáncer de mama, especialmente antes de ir a quirófano, desde la introducción de la quimioterapia preoperatoria por Fisher. Una de estas ha sido la radioterapia, la cual tiene beneficios claros en esa patología, pues reduce a la mitad el riesgo de recurrencia, y disminuye la muerte por cáncer de mama en aproximadamente una sexta parte después de cirugía conservadora. Aunque no se suele considerar antes de la cirugía, el uso de radioterapia preoperatoria en cáncer de mama, no es nuevo, y se ha demostrado que esta alternativa terapéutica es factible, bien tolerada y asociada a una tasa de respuesta patológica completa del 10 % -40 %. Se presenta el caso de una paciente con cáncer de mama metastásico, quien recibió múltiples esquemas de quimioterapia y a quien se le planteó radioterapia preoperatoria, recibiendo la misma con muy buena respuesta, sin aumentar la dificultad técnica para la realización de la intervención quirúrgica, y sin complicaciones asociadas a la herida operatoria. En la actualidad, existen pocos estudios clínicos sobre radioterapia preoperatoria, y su efecto en las pacientes con cáncer de mama localmente avanzado, es controvertido. Al observar en la biopsia definitiva respuesta patológica completa, es un indicio de cómo la radioterapia preoperatoria en cáncer de mama podría ser una opción en casos complejos con poca respuesta a la terapia convencional(AU)


Multiple therapeutic strategies have been developed with the aim of optimizing breast cancer (BC) treatment, especially preoperatively since the introduction of preoperative chemotherapy by Fisher. One of these has been radiation therapy (RT), which has clear benefits in breast cancer, halving the risk of recurrence andreducing breast cancer death byapproxmatelyone-sixth after breast-conserving surgery. Although not often considered for use prior to surgery, the use of preoperativeradiotherapy in localized breast cancer is not new andhas demonstrated that this therapeutic alternative is feasible, well tolerated and associated with a pathologic complete response rate of 10-40%. We present the case of a patient with metastatic breast cancer who received multiple chemotherapy schedules and who was considered preoperative radiotherapy, receiving the same with very good response, without increasing the technical difficulty for the performance of surgery, and without complications associated with the operative wound. At present, there are few clinical studies on preoperative radiotherapy, and its effect in patients with locally advanced breast cancer is controversial. And although this is a single case, observing a complete pathologic response in the definitive biopsy gives us a great indication of how preoperative radiotherapy in breast cancer could be an option in complex cases with little response to conventional therapy(AU)


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Radioterapia , Neoplasias da Mama/radioterapia
3.
Animals (Basel) ; 13(19)2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37835649

RESUMO

The effects of climate change on animals are typically viewed in terms of survivability and wellbeing. In this study, we broaden that purview to include climate impacts on reproductive capability. There are not only climate spaces for daily function, but climate cliffs that represent reproductive failures in the face of climate warming. This alternative focus suggests that climate warming challenges may be more immediate and profound than initially imagined. This research describes a state-of-the-art mechanistic model, Dairy Niche Mapper (DNM), and independent validation tests. Where test data are absent, the calculated results are consistent with expected responses. Simulations of metabolic chamber conditions reveal the local steady-state impacts of climate and animal variables on milk production capacity, metabolic rate, food consumption and water needs. Simulations of a temperature humidity index (THI) show strengths and limitations of that approach. Broader time- and spatial-scale calculations applied in the western and eastern halves of the northern hemisphere identify current and future monthly latitudinal climate change impacts on milk production potential, feed and water needs in dairy cows of different sizes. Dairy Niche Mapper (DNM) was developed from a broadly tested mechanistic microclimate-animal model, Niche Mapper (NM). DNM provides an improved quantitative understanding of the complex nonlinear interactions of climate variation and dairy bovine properties' effects on current and future milk production, feed and water needs for grazing and confinement dairy operations. DNM outputs include feasible activity times, milk production and water and feed needs of different-sized Holstein cows on high-grain (confinement feeding) versus high-forage (grazing feeding) diets at three arbitrary north latitudes, 12°, 30° and 60°, for North and Central America and for Asia. These three latitudes encompass current northern hemisphere bovine production environments and possible future production locations. The greatest impacts of climate change will be in the low elevations in tropical and subtropical regions. Global regions above 30° and below 60° latitude with reliable rainfall will be least affected by current projected levels of climate change. This work provides the basis for computational animal design for guiding agricultural development via breeding programs, genetic engineering, management options including siting or the manipulation of other relevant environmental and animal variables.

4.
Polymers (Basel) ; 13(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34641031

RESUMO

The drug development process can greatly benefit from liver-on-a-chip platforms aiming to recapitulate the physiology, mechanisms, and functionalities of liver cells in an in vitro environment. The liver is the most important organ in drug metabolism investigation. Here, we report the development of a hybrid cyclic olefin copolymer (COC) and polydimethylsiloxane (PDMS) microfluidic (HCP) platform to culture a Huh7 hepatoma cell line in dynamic conditions towards the development of a liver-on-a-chip system. The microfluidic platform is comprised of a COC bottom layer with a microchannel and PDMS-based flat top layer sandwiched together. The HCP device was applied for culturing Huh7 cells grown on a collagen-coated microchannel. A computational fluid dynamics modeling study was conducted for the HCP device design revealing the presence of air volume fraction in the chamber and methods for optimizing experimental handling of the device. The functionality and metabolic activity of perfusion culture were assessed by the secretion rates of albumin, urea, and cell viability visualization. The HCP device hepatic culture remained functional and intact for 24 h, as assessed by resulting levels of biomarkers similar to published studies on other in vitro and 2D cell models. The present results provide a proof-of-concept demonstration of the hybrid COC-PDMS microfluidic chip for successfully culturing a Huh7 hepatoma cell line, thus paving the path towards developing a liver-on-a-chip platform.

5.
Acta Parasitol ; 66(3): 1059-1062, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33564985

RESUMO

PURPOSE: Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, is a vector-borne disease with a major disease burden in the Americas, with over 6 million cases. There are about 200,000 cases in Ecuador, but the epidemiology of the disease is poorly understood, particularly in the Amazon region, making surveillance and control challenging. METHODS: We determined here the seroprevalence of T. cruzi antibodies in a cohort of 516 schoolchildren aged 5-15 years from Chontapunta parish, in the Napo province, Ecuador, using ELISA and indirect hemaglutination tests. RESULTS: We detected a seroprevalence of 0.77% (95% confidence interval 0.31-1.97%), with some significant variation among the three studied communities. CONCLUSION: These data provide evidence of the ongoing transmission of T. cruzi in this area, and support the need to strengthen epidemiological surveillance and patient care.


Assuntos
Doença de Chagas , Trypanosoma cruzi , Anticorpos Antiprotozoários , Doença de Chagas/epidemiologia , Criança , Equador/epidemiologia , Humanos , Estudos Soroepidemiológicos
6.
Biomedica ; 39(Supl. 2): 101-116, 2019 08 01.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31529838

RESUMO

Introduction: To reach the goal of malaria elimination in Ecuador for the year 2020, it is necessary to have a laboratory network with the capacity to perform microscopic diagnosis according to the WHO/PAHO quality standards and to provide the adequate treatment of cases. Objective: To determine the level of competence for parasitological diagnosis of the microscopists from the local public network and the performance of intermediate reference laboratories. Materials and methods: We conducted a cross-sectional study based on the information collected in workshops carried out to appraise the competence for microscopic diagnosis of the local laboratory network (zonal health coordinating offices 1 to 8) using a slide panel to evaluate diagnosis agreement, as well as the diagnostic performance of the intermediate laboratories using an external quality assessment program. The results were compared against the reference standards of the supranational laboratory in Perú. Results: We evaluated the competencies of 191 microscopists in 11 workshops and 153 (80.1%) of them were approved. The medians of the indicators were the following: concordance for parasite detection, 100% (Q1- Q3: 96-100), concordance for species identification, 100% (Q1- Q3: 93-100), and concordances for stage identification, 93.0% (Q1- Q3: 86-95) and parasite counting, 77.0% (Q1- Q3: 71-82). In the external quality assessment, the three intermediate laboratories obtained 100% in parasite detection concordance and 96% for species detection concordance. Conclusions: The results for the primary network and the performance indicators for the intermediate laboratories showed the high-quality standards of the training program implemented in the country.


Introducción. El cumplimiento de la meta de eliminación de la malaria en Ecuador en el 2020 exige contar con la capacidad requerida para el diagnóstico microscópico ajustado a los estándares de calidad de la Organización Mundial de la Salud (OMS) y de la Organización Panamericana de la Salud (OPS) y proveer el tratamiento adecuado a los pacientes. Objetivo. Conocer la idoneidad o competencia de los microscopistas de la red pública local para el diagnóstico parasitológico de la malaria y el desempeño de los laboratorios intermedios de referencia. Materiales y métodos. Se hizo un estudio descriptivo de corte transversal a partir de la información obtenida en los talleres de evaluación de idoneidad en el diagnóstico microscópico de la red de laboratorios en las coordinaciones zonales de salud utilizando un panel de láminas para evaluar la concordancia del diagnóstico. Además, se calificó el desempeño de los laboratorios intermedios en el diagnóstico en el marco del programa de evaluación externa del desempeño. Los resultados se compararon con los obtenidos por el laboratorio supranacional de Perú. Resultados. En los 11 talleres realizados, se evaluó la idoneidad de 191 microscopistas, de los cuales 153 (80,1 %) aprobaron las pruebas. Las medianas de los indicadores fueron las siguientes: concordancia entre la detección y el resultado, 100 % (Q1- Q3: 96-100); concordancia en la especie, 100 % (Q1- Q3: 93-100); concordancia en el estadio, 93,0 % (Q1- Q3: 86-95) y concordancia en el recuento, 77 % (Q1- Q3: 71-82). En el programa de evaluación externa de desempeño, los tres laboratorios intermedios obtuvieron una concordancia del 100 % en el resultado y una del 96 % en la especie. Conclusiones. Los indicadores de competencia de la red local y de desempeño de los laboratorios intermedios alcanzaron altos estándares de calidad acordes con el proceso de entrenamiento implementado en el país.


Assuntos
Eritrócitos/parasitologia , Ensaio de Proficiência Laboratorial , Malária Falciparum/diagnóstico , Malária Vivax/diagnóstico , Pessoal de Laboratório Médico/estatística & dados numéricos , Microscopia/métodos , Parasitemia/diagnóstico , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Estudos Transversais , Equador , Eritrócitos/ultraestrutura , Feminino , Humanos , Laboratórios/classificação , Laboratórios/normas , Malária Falciparum/sangue , Malária Falciparum/prevenção & controle , Malária Vivax/sangue , Malária Vivax/prevenção & controle , Masculino , Pessoal de Laboratório Médico/educação , Microscopia/normas , Parasitemia/sangue , Parasitemia/prevenção & controle , Prática Profissional/estatística & dados numéricos , Garantia da Qualidade dos Cuidados de Saúde , Fatores Socioeconômicos
7.
Biomédica (Bogotá) ; 39(supl.2): 101-116, ago. 2019. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1038832

RESUMO

Resumen Introducción. El cumplimiento de la meta de eliminación de la malaria en Ecuador en el 2020 exige contar con la capacidad requerida para el diagnóstico microscópico ajustado a los estándares de calidad de la Organización Mundial de la Salud (OMS) y de la Organización Panamericana de la Salud (OPS) y proveer el tratamiento adecuado a los pacientes. Objetivo. Conocer la idoneidad o competencia de los microscopistas de la red pública local para el diagnóstico parasitológico de la malaria y el desempeño de los laboratorios intermedios de referencia. Materiales y métodos. Se hizo un estudio descriptivo de corte transversal a partir de la información obtenida en los talleres de evaluación de idoneidad en el diagnóstico microscópico de la red de laboratorios en las coordinaciones zonales de salud utilizando un panel de láminas para evaluar la concordancia del diagnóstico. Además, se calificó el desempeño de los laboratorios intermedios en el diagnóstico en el marco del programa de evaluación externa del desempeño. Los resultados se compararon con los obtenidos por el laboratorio supranacional de Perú. Resultados. En los 11 talleres realizados, se evaluó la idoneidad de 191 microscopistas, de los cuales 153 (80,1 %) aprobaron las pruebas. Las medianas de los indicadores fueron las siguientes: concordancia entre la detección y el resultado, 100 % (Q1- Q3: 96-100); concordancia en la especie, 100 % (Q1- Q3: 93-100); concordancia en el estadio, 93,0 % (Q1- Q3: 86-95) y concordancia en el recuento, 77 % (Q1- Q3: 71-82). En el programa de evaluación externa de desempeño, los tres laboratorios intermedios obtuvieron una concordancia del 100 % en el resultado y una del 96 % en la especie. Conclusiones. Los indicadores de competencia de la red local y de desempeño de los laboratorios intermedios alcanzaron altos estándares de calidad acordes con el proceso de entrenamiento implementado en el país.


Abstract Introduction: To reach the goal of malaria elimination in Ecuador for the year 2020, it is necessary to have a laboratory network with the capacity to perform microscopic diagnosis according to the WHO/PAHO quality standards and to provide the adequate treatment of cases. Objective: To determine the level of competence for parasitological diagnosis of the microscopists from the local public network and the performance of intermediate reference laboratories. Materials and methods: We conducted a cross-sectional study based on the information collected in workshops carried out to appraise the competence for microscopic diagnosis of the local laboratory network (zonal health coordinating offices 1 to 8) using a slide panel to evaluate diagnosis agreement, as well as the diagnostic performance of the intermediate laboratories using an external quality assessment program. The results were compared against the reference standards of the supranational laboratory in Perú. Results: We evaluated the competencies of 191 microscopists in 11 workshops and 153 (80.1%) of them were approved. The medians of the indicators were the following: concordance for parasite detection, 100% (Q1- Q3: 96-100), concordance for species identification, 100% (Q1- Q3: 93-100), and concordances for stage identification, 93.0% (Q1- Q3: 86-95) and parasite counting, 77.0% (Q1- Q3: 71-82). In the external quality assessment, the three intermediate laboratories obtained 100% in parasite detection concordance and 96% for species detection concordance. Conclusions: The results for the primary network and the performance indicators for the intermediate laboratories showed the high-quality standards of the training program implemented in the country.


Assuntos
Feminino , Humanos , Masculino , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Malária Vivax/diagnóstico , Malária Falciparum/diagnóstico , Pessoal de Laboratório Médico/estatística & dados numéricos , Parasitemia/diagnóstico , Eritrócitos/parasitologia , Ensaio de Proficiência Laboratorial , Microscopia/métodos , Prática Profissional/estatística & dados numéricos , Garantia da Qualidade dos Cuidados de Saúde , Fatores Socioeconômicos , Estudos Transversais , Malária Vivax/sangue , Malária Vivax/prevenção & controle , Malária Falciparum/sangue , Malária Falciparum/prevenção & controle , Pessoal de Laboratório Médico/educação , Parasitemia/sangue , Parasitemia/prevenção & controle , Equador , Eritrócitos/ultraestrutura , Laboratórios/classificação , Laboratórios/normas , Microscopia/normas
9.
Biosensors (Basel) ; 7(4)2017 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-28972568

RESUMO

Tuberculosis (TB) remains one of the main causes of human death around the globe. The mortality rate for patients infected with active TB goes beyond 50% when not diagnosed. Rapid and accurate diagnostics coupled with further prompt treatment of the disease is the cornerstone for controlling TB outbreaks. To reduce this burden, the existing gap between detection and treatment must be addressed, and dedicated diagnostic tools such as biosensors should be developed. A biosensor is a sensing micro-device that consists of a biological sensing element and a transducer part to produce signals in proportion to quantitative information about the binding event. The micro-biosensor cell considered in this investigation is designed to operate based on aptamers as recognition elements against Mycobacterium tuberculosis secreted protein MPT64, combined in a microfluidic-chamber with inlet and outlet connections. The microfluidic cell is a miniaturized platform with valuable advantages such as low cost of analysis with low reagent consumption, reduced sample volume, and shortened processing time with enhanced analytical capability. The main purpose of this study is to assess the flooding characteristics of the encapsulated microfluidic cell of an existing micro-biosensor using Computational Fluid Dynamics (CFD) techniques. The main challenge in the design of the microfluidic cell lies in the extraction of entrained air bubbles, which may remain after the filling process is completed, dramatically affecting the performance of the sensing element. In this work, a CFD model was developed on the platform ANSYS-CFX using the finite volume method to discretize the domain and solving the Navier-Stokes equations for both air and water in a Eulerian framework. Second-order space discretization scheme and second-order Euler Backward time discretization were used in the numerical treatment of the equations. For a given inlet-outlet diameter and dimensions of an in-house built cell chamber, different inlet liquid flow rates were explored to determine an appropriate flow condition to guarantee an effective venting of the air while filling the chamber. The numerical model depicted free surface waves as promoters of air entrainment that ultimately may explain the significant amount of air content in the chamber observed in preliminary tests after the filling process is completed. Results demonstrated that for the present design, against the intuition, the chamber must be filled with liquid at a modest flow rate to minimize free surface waviness during the flooding stage of the chamber.


Assuntos
Técnicas Biossensoriais , Biologia Computacional/métodos , Humanos
10.
Infect Genet Evol ; 41: 207-212, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27079265

RESUMO

Chagas disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. In Ecuador, Triatoma dimidiata and Rhodnius ecuadoriensis are the main vector species, responsible for over half of the cases of T. cruzi infection in the country. T. dimidiata is believed to have been introduced in Ecuador during colonial times, and its elimination from the country is thus believed to be feasible. We investigated here the molecular ecology of T. dimidiata and T. cruzi in costal Ecuador to further guide control efforts. Analysis of the Internal Transcribed Spacer 2 (ITS-2) of 23 specimens from Progreso, Guayas, unambiguously supported the likely importation of T. dimidiata from Central America to Ecuador. The observation of a very high parasite infection rate (54%) and frequent feeding on humans (3/5) confirmed a continued risk of transmission to humans. All genotyped parasites corresponded to TcI DTU and Trypanosoma rangeli was not detected in T. dimidiata. TcI subgroups corresponded to TcIa (25%), and mixed infections with TcIa and TcId (75%). Further studies should help clarify T. cruzi genetic structure in the country, and the possible impact of the introduction of T. dimidiata on the circulating parasite strains. The elevated risk posed by this species warrants continuing efforts for its control, but its apparent mobility between peridomestic and domestic habitats may favor reinfestation following insecticide spraying.


Assuntos
Doença de Chagas/transmissão , DNA Intergênico/genética , Espécies Introduzidas , Estágios do Ciclo de Vida/genética , Filogenia , Triatoma/genética , Animais , Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia , Ecossistema , Equador/epidemiologia , Comportamento Alimentar/fisiologia , Feminino , Genótipo , Humanos , Controle de Insetos , Insetos Vetores , Masculino , Epidemiologia Molecular , Rhodnius/parasitologia , Triatoma/classificação , Triatoma/crescimento & desenvolvimento , Triatoma/parasitologia , Trypanosoma cruzi/patogenicidade , Trypanosoma cruzi/fisiologia
11.
Trop Med Int Health ; 21(1): 84-92, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26458237

RESUMO

OBJECTIVE: To describe the current situation of Chagas disease in Ecuador and to evaluate the impact of vector control for the period 2004-2014. METHODS: Since 2004, the Ministry of Public Health has formalized activities for the surveillance and control of Chagas disease and we analyzed here available records. RESULTS: More than 200 000 houses were surveyed, and 2.6% were found to be infested (95% CI: 2.6-2.7), and more than 51 000 houses were sprayed with residual insecticide, with important yearly variations. A total of 915 cases of T. cruzi infection were registered. The Amazon region is emerging as a high priority area, where nearly half of T. cruzi infection cases originate. The costal region and the southern highland valleys remain important high-risk area. Vector control efforts over the past 10 years have been effective in the coastal region, where T. dimidiata predominates, and resulted in important reductions in house infestation indices in many areas, even reaching negligible levels in some parishes. CONCLUSION: Vector efforts need to be sustained and expanded for the elimination of T. dimidiata to be feasible. Novel vector control interventions need to be designed to reduce intrusion by several triatomine species present in the Amazon region and southern Ecuador. Strong political commitment is needed to sustain current achievements and improve the national coverage of these programmes.

12.
Chem Eng Trans ; 49: 73-78, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28458778

RESUMO

Abdominal aortic aneurysm (AAA) is a dilation of the abdominal aorta (above 50 % of its original diameter), which can cause death upon rupturing. It usually grows asymptomatically leading to late clinical intervention. The medical criteria to indicate surgery are based on measuring the diameter and growth rate, but in many cases aneurysms fail at uncharacterized critical values. In search of a more efficient technique in predicting AAA failure, there is consensus on the importance of studying its geometric characteristics and estimation of the wall stress, but no fully successful correlation has been found between the two yet. This work examines the relationship between a parameterized geometry (18 input variables and 10 dependent indices) and 1 output variable: the maximum wall stress. Design of Experiments (DOE) techniques are used to generate 183 geometric configurations, for which Finite Element Analyses are performed using ANSYS™ state-of-the-art solver with a hyperelastic, isotropic and homogeneous arterial model for the wall, considering systolic internal pressure (steady state) and the restriction of longitudinal movement at the blood vessel end-sections. Due to the large number of independent parameters to consider, a preliminary Parameters Correlation analysis was performed to determine if a correlation between all input parameters and the maximum stress existed. The correlations between input parameters and the output variable were determined using the Spearman Rank correlation. Correlations with the maximum wall stress for: maximum diameter (ρ = 0.46), wall thickness (ρ = 0.35), dc parameter (ρ = 0.21) and tortuosity (ρ = 0.55) were found. The response surface function between geometry and maximum wall stress was estimated by three models: Universal Kriging geostatistical regression (18 parameters), multiple linear regression (4 parameters) and multiple exponential regression (4 parameters). The models accounted for the stress variance by 99 %, 61 % and 66 %, respectively, with average percentage errors of 0.12 %, 16 % and 17 %, respectively. The solution spaces obtained from this study might provide physicians with a better estimation of the AAA rupture potential and thus, facilitate safer and anticipated treatments of the condition.

13.
Waste Manag Res ; 33(5): 486-94, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25819927

RESUMO

The city of Astana, the capital of Kazakhstan, which has a population of 804,474, and has been experiencing rapid growth over the last 15 years, generates approximately 1.39 kg capita(-1) day(-1) of municipal solid waste (MSW). Nearly 700 tonnes of MSW are collected daily, of which 97% is disposed of at landfills. The newest landfill was built using modern technologies, including a landfill gas (LFG) collection system.The rapid growth of Astana demands more energy on its path to development, and the viability analysis of MSW to generate electricity is imperative. This paper presents a technical-economic pre-feasibility study comparing landfill including LFG utilization and waste incineration (WI) to produce electricity. The performance of LFG with a reciprocating engine and WI with steam turbine power technologies were compared through corresponding greenhouse gases (GHG) reduction, cost of energy production (CEP), benefit-cost ratio (BCR), net present value (NPV) and internal rate of return (IRR) from the analyses. Results demonstrate that in the city of Astana, WI has the potential to reduce more than 200,000 tonnes of GHG per year, while LFG could reduce slightly less than 40,000 tonnes. LFG offers a CEP 5.7% larger than WI, while the latter presents a BCR two times higher than LFG. WI technology analysis depicts a NPV exceeding 280% of the equity, while for LFG, the NPV is less than the equity, which indicates an expected remarkable financial return for the WI technology and a marginal and risky scenario for the LFG technology. Only existing landfill facilities with a LFG collection system in place may turn LFG into a viable project.


Assuntos
Conservação de Recursos Energéticos/métodos , Gases/análise , Incineração , Cidades , Fontes Geradoras de Energia , Cazaquistão , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos
14.
Philos Trans R Soc Lond B Biol Sci ; 368(1619): 20120155, 2013 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-23610166

RESUMO

A mosaic of protected areas, including indigenous lands, sustainable-use production forests and reserves and strictly protected forests is the cornerstone of conservation in the Amazon, with almost 50 per cent of the region now protected. However, recent research indicates that isolation from direct deforestation or degradation may not be sufficient to maintain the ecological integrity of Amazon forests over the next several decades. Large-scale changes in fire and drought regimes occurring as a result of deforestation and greenhouse gas increases may result in forest degradation, regardless of protected status. How severe or widespread these feedbacks will be is uncertain, but the arc of deforestation in south-southeastern Amazonia appears to be particularly vulnerable owing to high current deforestation rates and ecological sensitivity to climate change. Maintaining forest ecosystem integrity may require significant strengthening of forest conservation on private property, which can in part be accomplished by leveraging existing policy mechanisms.


Assuntos
Conservação dos Recursos Naturais/métodos , Ecossistema , Clima Tropical , Brasil , Dióxido de Carbono/análise , Secas , Política Ambiental , Incêndios , Efeito Estufa , Chuva , Árvores
15.
Philos Trans R Soc Lond B Biol Sci ; 363(1498): 1881-8, 2008 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-18267917

RESUMO

Protected area systems and conservation corridors can help mitigate the impacts of climate change on Amazonian biodiversity. We propose conservation design criteria that will help species survive in situ or adjust range distributions in response to increased drought. The first priority is to protect the western Amazon, identified as the 'Core Amazon', due to stable rainfall regimes and macro-ecological phenomena that have led to the evolution of high levels of biodiversity. Ecotones can buffer the impact from climate change because populations are genetically adapted to climate extremes, particularly seasonality, because high levels of habitat diversity are associated with edaphic variability. Future climatic tension zones should be surveyed for geomorphological features that capture rain or conserve soil moisture to identify potential refugia for humid forest species. Conservation corridors should span environmental gradients to ensure that species can shift range distributions. Riparian corridors provide protection to both terrestrial and aquatic ecosystems. Multiple potential altitudinal corridors exist in the Andes, but natural and anthropogenic bottlenecks will constrain the ability of species to shift their ranges and adapt to climate change. Planned infrastructure investments are a serious threat to the potential to consolidate corridors over the short and medium term.


Assuntos
Conservação dos Recursos Naturais/métodos , Efeito Estufa , Altitude , Ecossistema , Chuva , Rios , Meios de Transporte
16.
Ambio ; 36(7): 600-6, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18074899

RESUMO

Land-cover change in eastern lowland Bolivia was documented using Landsat images from five epochs for all landscapes situated below the montane tree line at approximately 3000 m, including humid forest, inundated forest, seasonally dry forest, and cloud forest, as well as scrublands and grasslands. Deforestation in eastern Bolivia in 2004 covered 45,411 km2, representing approximately 9% of the original forest cover, with an additional conversion of 9042 km2 of scrub and savanna habitats representing 17% of total historical land-cover change. Annual rates of land-cover change increased from approximately 400 km2 y(-1) in the 1960s to approximately 2900 km2 y(-1) in the last epoch spanning 2001 to 2004. This study provides Bolivia with a spatially explicit information resource to monitor future land-cover change, a prerequisite for proposed mechanisms to compensate countries for reducing carbon emissions as a result of deforestation. A comparison of the most recent epoch with previous periods shows that policies enacted in the late 1990s to promote forest conservation had no observable impact on reducing deforestation and that deforestation actually increased in some protected areas. The rate of land-cover change continues to increase linearly nationwide, but is growing faster in the Santa Cruz department because of the expansion of mechanized agriculture and cattle farms.


Assuntos
Conservação dos Recursos Naturais/métodos , Agricultura Florestal/métodos , Bolívia , Conservação dos Recursos Naturais/tendências , Ecossistema , Monitoramento Ambiental/métodos , Agricultura Florestal/tendências , Geografia , Humanos
17.
Accid Anal Prev ; 36(1): 37-42, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14572825

RESUMO

The objective of this study was to do an epidemiological and costs analysis of the impact of road traffic injuries on the demand for emergency room services at hospitals located in the city of Cuernavaca, Mexico. The studied population included injured people who demanded medical attention at the emergency room for injuries due to events in public places, occurring between February and April 2001. Trained interviewers collected the data at the emergency room, 24h a day. The statistical analysis included simple and bivariate analysis using chi(2) odds ratio (OR), and a confidence interval of 95%. The costs analysis included the expenses during the process of searching for and finding care for injuries. There were 433 injured people, 233 (54%) were victims of road traffic accidents, 72% of crashes, and 28% were injured pedestrian and cyclists. Variables associated with the demand of emergency care due to road traffic injuries in comparison with other accidents, were: severity of injuries (OR 2.60, CI 1.44-4.71), and thorax injury (OR 4.64, CI 1.03-20.89). Pedestrians had higher costs for health care and 80% of them had to pay out-of-pocket (P<0.05). Differences between patients injured by crashes or as a pedestrian, were: age under 14 years (OR 5.9, CI 2.5-13.9), being unemployed (OR 2.1, CI 1.20-3.96), and being an elementary school student (OR 13.9, CI 3.08-63.13). The present study is, so far, the only one in Mexico to include an epidemiological and costs analysis in approaching the problem of road traffic injuries. Similar methods must be used, especially in developing countries, to reduce this important public health problem.


Assuntos
Acidentes de Trânsito/estatística & dados numéricos , Serviço Hospitalar de Emergência/economia , Custos de Cuidados de Saúde , Serviços Urbanos de Saúde/economia , Ferimentos e Lesões/epidemiologia , Acidentes de Trânsito/economia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Custos e Análise de Custo , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Humanos , Lactente , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Serviços Urbanos de Saúde/estatística & dados numéricos , Ferimentos e Lesões/economia , Ferimentos e Lesões/terapia
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