Traveling with an invader: ectoparasitic mites of Hemidactylus frenatus (Squamata: Gekkonidae) in Colombia

Information about natural history of invasive species (such as parasitism) is a relevant issue in order to consider potential threats to native fauna. In this work we report two pterygosomatid mites for the first time in Colombia, Geckobia bataviensis and G. keegani, parasites of the invasive house gecko Hemidactylus frenatus. Although it has not been demonstrated that these mites may infest native gecko lizards, our study highlights the need to explore the prevalence of internal and external parasites in native and invasive geckos, to better evaluate the potential impact of invasive Hemidactylus lizards in Colombia.Asociación Herpetológica Argentin

Traveling with an invader: ectoparasitic mites of Hemidactylus frenatus (Squamata: Gekkonidae) in Colombia

Information about natural history of invasive species (such as parasitism) is a relevant issue in order to consider potential threats to native fauna. In this work we report two pterygosomatid mites for the first time in Colombia, Geckobia bataviensis and G. keegani, parasites of the invasive house gecko Hemidactylus frenatus. Although it has not been demonstrated that these mites may infest native gecko lizards, our study highlights the need to explore the prevalence of internal and external parasites in native and invasive geckos, to better evaluate the potential impact of invasive Hemidactylus lizards in Colombia.Asociación Herpetológica Argentin

Traveling with an invader: ectoparasitic mites of Hemidactylus frenatus (Squamata: Gekkonidae) in Colombia

Information about natural history of invasive species (such as parasitism) is a relevant issue in order to consider potential threats to native fauna. In this work we report two pterygosomatid mites for the first time in Colombia, Geckobia bataviensis and G. keegani, parasites of the invasive house gecko Hemidactylus frenatus. Although it has not been demonstrated that these mites may infest native gecko lizards, our study highlights the need to explore the prevalence of internal and external parasites in native and invasive geckos, to better evaluate the potential impact of invasive Hemidactylus lizards in Colombia.Asociación Herpetológica Argentin

Improving Pump Characteristics through Double Curvature Impellers: Experimental Measurements and 3D CFD Analysis

The outlet angle and shape of impeller blades are important parameters in centrifugal pump design. There is a lack of detailed studies related to double curvature impellers in centrifugal pumps in the current literature; therefore, an experimental and numerical analysis of double curvature impellers was performed. Six impellers were made and then assessed in a centrifugal pump test bed and simulated via 3D CFD simulation. The original impeller was also tested and simulated. One of the manufactured impellers had the same design as the original, and the other five impellers had a double curvature. Laboratory tests and simulations were conducted with three rotation speeds: 1400, 1700, and 1900 RPM. Head and performance curve equations were obtained for the pump–engine unit based on the flow of each impeller for the three rotation speeds. The results showed that a double curvature impeller improved pump head by approximately 1 m for the range of the study and performance by about 2% when compared to basic impeller. On the other hand, it was observed that turbulence models such as k-e and SST k-w reproduced similar physical and numerical results

Determinantes de los ingresos laborales de los economistas en Colombia : un análisis de modelación micro econométrica.

This research analyzes the determinants of labor income of economists in Colombia for the third quarter of 2010 and 2016, within the framework of a theoretical perspective of human capital. With information from the Large Integrated Household Survey of the National Administrative Department of Statistics (DANE), a classical mincerian equation is estimated to measure the effect of schooling and potential experience on the incomes of graduates in economics. After applying the Ordinary Least Squares method, the results suggest that an additional year of school education and on-the-job job training has a positive effect on the probability of earning higher job earnings. Additionally, applying the Mincer model for related professions, it was evident that the human capital variables have significantly different impacts for each group of professionals, therefore the hypothesis of a homogeneous labor market is not fulfilled for the study period.En la presente investigación se analizan los factores determinantes de los ingresos laborales de los economistas en Colombia para el tercer trimestre de los años 2010 y 2016, en el marco de una perspectiva teórica de capital humano. Con información de la Gran Encuesta Integrada de Hogares del Departamento Administrativo Nacional de Estadística (DANE), se estima una ecuación minceriana clásica para medir el efecto de la escolaridad y la experiencia potencial en los ingresos de los titulados en economía. Después de aplicar el método de Mínimos Cuadrados Ordinarios, los resultados sugieren que un año adicional de formación escolar y entrenamiento laboral en el puesto de trabajo genera un efecto positivo sobre la probabilidad de devengar ingresos laborales más altos. Adicionalmente, aplicando el modelo de Mincer para las profesiones afines se pudo evidenciar que las variables de capital humano tienen impactos significativamente diferentes para cada grupo de profesionales, por lo cual la hipótesis planteada de un mercado laboral homogéneo no se cumple para el periodo de estudio

Assessment and ranking of the severity of disturbances in the Mexican Interconnected System

This paper adopts a methodology to assess and rank the severity of the most frequent disturbances, 3 types in particular, that occur in the Mexican Interconnected System (MIS) when wind power plants (WPPs) are integrated. This is done by combining three stability indices from which an overall performance measure can be derived. In this way, it is possible to assess the severity of the disturbances such as generation tripping, line tripping and disconnection of loads. The indices under consideration include measures such as maximum amplitude, speed variation, and the Lyapunov exponent. For ranking the severity, a general index value is used. To confirm the effectiveness and performance of the proposed methodology, this paper investigates the 190-bus and 46-generator MIS equipped with an 8% of wind generation to quantitatively evaluate the severity of disturbances, resulting in 66% of unstable disturbances which are associated with the disconnection of loads

Trend analysis to determine hazards related to climate change in the andean agricultural areas of cundinamarca and boyacá

Recognizing the threat from climate change that is facing and will face agro ecosystems is the first step in determining adaptation to climate change. One way is through Global Climate Models (GCMs), but their spatial resolution is not best suited for making decisions locally, further reducing scale, seen as a way to resolve the resolution problem, has not yielded the expected results. This study puts forth an exercise in which we study the climatic time series of precipitation and temperature to determine if there are effects of climate change on one of the most important national agricultural areas, using the Mann-Kendall analysis to determine the existence of statistically significant trends, i.e. signs of change in the variables analyzed. It was found that the variable that presents the most significant trends is the average maximum temperature, while precipitation and average minimum temperature do not

Quantifying the years of life lost due to COVID-19 in Colombia: preliminary estimates

To estimate the years of life lost (YLLs) due to COVID-19 in Colombia and assess its economic impact by valuing the potential years of productive life lost (PYLLs). We conducted an ecological study to estimate the number of premature deaths associated with COVID-19 and calculate the present value of their expected future earnings using a discount rate of 3%. We considered deaths occurred from March to November 9, 2020. We used the modified criteria in the 2010 Global Burden of Disease (GBD) Study to estimate YLLs, adding the deaths for each age group and multiplied by the life expectancy of the respective age group up to the age limit considered. From the human capital approach, we estimated PYLLs to show the number of years of premature deaths caused by COVID-19, when fatalities occurred between 15-64 years old, the timeframe of economically active life for all estimates. We present results in 2020 U.S. dollars. The 32,974 deaths from COVID-19 have produced 697,512 YLLs, of which 66.0% are in men. Around 76.2% of these YLLs occur in people >50 years. On average, each death from COVID-19 contributed 21.2 YLL. The YLLs rate is 1,385 (women: 963; men: 1,787) per 100,000 inhabitants. The mean rate of YLLs in people aged ≥50 years is about ten times that of those <50 years (5,059 vs. 561 per 100,000). Premature deaths in the Colombian economically active population accounted for 89,667 PYLLs (74.6% in men). 58.8% of the PYLLs occurred in the population aged 40-64 years. The economic burden associated with this goes from US$168 to US$306 million (0.05-0.10% of the 2019 gross domestic product). At the end of 2020, COVID-19 would be the leading cause of death in Colombia and the most critical disease burden factor, above cardiovascular diseases, and neonatal disorders

Familial hypercholesterolaemia: A study of 36 cases with a phenotype of homozygous familiar hypercholesterolaemia

La hipercolesterolemia familiar homocigótica (HFHo) se caracteriza por niveles muy elevados de cLDL y por enfermedad aterosclerótica temprana. Aunque la frecuencia es baja (1/300.000), las complicaciones son muy severas y pueden ser evitadas. Encontrar y tratar esta población de manera temprana podría reducir la mortalidad. Se describen 36 casos en Colombia, en donde se calcula que haya entre 160 y 200 casos. Resultados Un total de 36 pacientes con fenotipo sugestivo de HFHo fueron identificados y tratados en un período de observación de cuatro años. La media de edad fue 27 años (24 mujeres). 34 pacientes tuvieron un puntaje según la Red de Clínicas de Lípidos de Holanda (RCLH) mayor de 8 (diagnóstico definitivo) y los restantes 2 tenían puntaje equivalente a diagnóstico probable. Un cuarto de los casos procedían de la costa norte colombiana. En las pruebas genéticas, 14 fueron homocigóticos verdaderos para mutación del gen que codifica para el receptor de LDL (LDLR), 12 heterocigóticos compuestos, 2 heterocigóticos dobles y uno autosómico recesivo (LDLRAP1); 5 pacientes fueron heterocigóticos simples (LDLR) y 2 pacientes no autorizaron la prueba. En los homocigóticos verdaderos, la variante más frecuente encontrada fue la c.11G>A. 14 pacientes cursaron con enfermedad coronaria, 9 con estenosis carotídea, 8 con estenosis aórtica y 2 tuvieron ataques cerebrovasculares (ACV). 34 pacientes recibían estatinas (24 rosuvastatina), 30 recibían ezetimibe, 2 recibían evolocumab y 20 recibían lomitapide (dosis promedio 12,7mg). Ninguno recibió aféresis de cLDL. Los medicamentos, en general, fueron bien tolerados y la reducción promedio de cLDL con la terapia fue de 533,7mg/dl a 245,1mg/dl (54%). Conclusiones Todos los pacientes recibieron tratamiento hipolipemiante y se encontraron alteraciones genéticas diagnósticas en todos aquellos que autorizaron el examen. Los niveles elevados de cLDL conllevan tanto riesgo que el tratamiento debe establecerse aún sin conocer el diagnóstico genético.Homozygous familial hypercholesterolemia (HoFH) is characterized for very high levels of cLDL and early cardiovascular disease. Although incidence is low (1/300 000), complications are very severe and can be avoided. Finding and treating this population promptly could reduce mortality. We describe 36 cases in Colombia, where 160 to 200 cases are expected. Results 36 patients with phenotype of HoHF were identified and treated in a follow-up of 4 years. The mean age was 27 years (24 women). 34 of them had at least 8 points in the FH Dutch Lipid Clinic Criteria (definitive diagnosis) and two had probable diagnosis. A quarter of the cases came from the Colombian North Coast. In molecular tests, 14 were true homozygous for LDLR, 12 were compound heterozygous for LDLR, 2 double heterozygous and one was autosomal recessive; 5 were heterozygous and 2 patients did not authorized genetic test. In true homozygous subjects, the most frequent variant was c.11G>A. 14 patients had coronary disease, 9 carotid stenosis, 8 aortic stenosis and 2 had stroke. 34 patients were on statins (25 rosuvastatin), 30 were receiving ezetimibe, 2 were receiving a PSCK9 inhibitor (evolocumab) and 20 were on lomitapide with mean doses of 12.7mg. None received lipoprotein apheresis. Medications were very well tolerated. Changes in cLDL after therapy was from 533.7 mg/dL to 245 mg/dL, (54%). Conclusions Treatment was started in all patients. We found genetic mutations in all patients with genetic tests. The high levels of cLDL mean such a high risk that treatment must be started promptly, even without a genetic test

Eco-epidemiological analysis of rickettsial seropositivity in rural areas of Colombia: A multilevel approach

ABSTARCT: Rickettsiosis is a re-emergent infectious disease without epidemiological surveillance in Colombia. This disease is generally undiagnosed and several deadly outbreaks have been reported in the country in the last decade. The aim of this study is to analyze the eco-epidemiological aspects of rickettsial seropositivity in rural areas of Colombia where outbreaks of the disease were previously reported. A cross-sectional study, which included 597 people living in 246 households from nine hamlets in two municipalities of Colombia, was conducted from November 2015 to January 2016. The survey was conducted to collect sociodemographic and household characteristics (exposure) data. Blood samples were collected to determine the rickettsial seropositivity in humans, horses and dogs (IFA, cut-off = 1/128). In addition, infections by rickettsiae were detected in ticks from humans and animals by real-time PCR targeting gltA and ompA genes. Data was analyzed by weighted multilevel clog-log regression model using three levels (person, household and hamlets) and rickettsial seropositivity in humans was the main outcome. Overall prevalence of rickettsial seropositivity in humans was 25.62% (95%CI 22.11-29.12). Age in years (PR = 1.01 95%CI 1.01-1.02) and male sex (PR = 1.65 95%CI 1.43-1.90) were risk markers for rickettsial seropositivity. Working outdoors (PR = 1.20 95%CI 1.02-1.41), deforestation and forest fragmentation for agriculture use (PR = 1.75 95%CI 1.51-2.02), opossum in peridomiciliary area (PR = 1.56 95%CI 1.37-1.79) and a high proportion of seropositive domestic animals in the home (PR20-40% vs 40% vs <20% = 3.14 95%CI 2.43-4.04) were associated with rickettsial seropositivity in humans. This study showed the presence of Rickettsia antibodies in human populations and domestic animals. In addition, different species of rickettsiae were detected in ticks collected from humans and animals. Our results highlighted the role of domestic animals as sentinels of rickettsial infection to identify areas at risk of transmission, and the importance of preventive measures aimed at curtailing deforestation and the fragmentation of forests as a way of reducing the risk of transmission of emergent and re-emergent pathogens