Fractional Integration Versus Structural Change: Testing the Convergence of CO2 Emissions

This paper assesses the stochastic convergence of relative CO₂ emissions within 28 OECD countries over the period 1950–2013. Using the local Whittle estimator and some of its variants we assess whether relative per capita CO₂ emissions are long memory processes which, although highly persistent, may revert to their mean/trend in the long run thereby indicating evidence of stochastic convergence. Furthermore, we test whether (possibly) slow convergence or the complete lack of it may be the result of structural changes to the deterministics of each of the relative per-capita emissions series by means of the tests of Berkes et al. (Ann Stat 1140–1165, 2006) and Mayoral (Oxford Bull Econ Stat 74(2):278–305, 2012). Our results show relatively weak support for stochastic convergence of CO₂ emissions, indicating that only between 30 and 40% of the countries converge to the OECD average in a stochastic sense. This weak evidence disappears if we enlarge the sample to include 4 out of the 5 BRICS, indicating that our results are not robust to the inclusion of countries which are experiencing rates of growth which are far larger than those of the OECD members. Our results also decisively indicate that a slow or lack of convergence is not the results of a structural break in the relative CO₂ emissions series

La renovación de la palabra en el bicentenario de la Argentina : los colores de la mirada lingüística

El libro reúne trabajos en los que se exponen resultados de investigaciones presentadas por investigadores de Argentina, Chile, Brasil, España, Italia y Alemania en el XII Congreso de la Sociedad Argentina de Lingüística (SAL), Bicentenario: la renovación de la palabra, realizado en Mendoza, Argentina, entre el 6 y el 9 de abril de 2010. Las temáticas abordadas en los 167 capítulos muestran las grandes líneas de investigación que se desarrollan fundamentalmente en nuestro país, pero también en los otros países mencionados arriba, y señalan además las áreas que recién se inician, con poca tradición en nuestro país y que deberían fomentarse. Los trabajos aquí publicados se enmarcan dentro de las siguientes disciplinas y/o campos de investigación: Fonología, Sintaxis, Semántica y Pragmática, Lingüística Cognitiva, Análisis del Discurso, Psicolingüística, Adquisición de la Lengua, Sociolingüística y Dialectología, Didáctica de la lengua, Lingüística Aplicada, Lingüística Computacional, Historia de la Lengua y la Lingüística, Lenguas Aborígenes, Filosofía del Lenguaje, Lexicología y Terminología

Non-Linear Model to Describe Growth Curves of Commercial Turkey in the Tropics of Mexico

ABSTRACT The objective of this study was to select the best non-linear model that fits the growth curve of turkeys managed under the tropical conditions of Southern Mexico. Data from 481 Hybrid converter turkeys (236 females and 245 males) reared under commercial conditions typical of that region were used. Turkeys were given ad libitum access to feed and water. Body weight was weekly recorded from 1 day to 23 weeks of age. Five non-linear mathematical models (Brody, Gompertz, Logistic, von Bertalanffy and Richards) were chosen to describe the age-weight relationship. The Brody and Richards' models fail to converge. The best fitting model was chosen based on the average prediction error (APE); the multiple determination coefficient R2 and the Akaike information criterion (AIC). In both sexes, von Bertalanffy and Gompertz were the best models. The highest estimates of parameter A (mature weight) for both females and males were obtained with the von Bertalanffy model followed by the Gompertz and Logistic. The estimates of A were higher for males than for females. The highest estimates of parameter k (rate of maturity) for both females and males were, in decreasing order for the Logistic, Gompertz, and von Bertalanffy models. k values for female turkeys was higher than for males. The age at the point of inflection and body weight at the age of point of inflection varied with the model used. The largest values of TI and WI corresponded to the Logistic model. Between sexes, the largest TI and WI values corresponded to males. The best models to describe turkey growth were the von Bertalanffy and Gompertz models, because it presented the highest APE, R2 and AIC values

Non-Linear Model to Describe Growth Curves of Commercial Turkey in the Tropics of Mexico

<div><p>ABSTRACT The objective of this study was to select the best non-linear model that fits the growth curve of turkeys managed under the tropical conditions of Southern Mexico. Data from 481 Hybrid converter turkeys (236 females and 245 males) reared under commercial conditions typical of that region were used. Turkeys were given ad libitum access to feed and water. Body weight was weekly recorded from 1 day to 23 weeks of age. Five non-linear mathematical models (Brody, Gompertz, Logistic, von Bertalanffy and Richards) were chosen to describe the age-weight relationship. The Brody and Richards' models fail to converge. The best fitting model was chosen based on the average prediction error (APE); the multiple determination coefficient R2 and the Akaike information criterion (AIC). In both sexes, von Bertalanffy and Gompertz were the best models. The highest estimates of parameter A (mature weight) for both females and males were obtained with the von Bertalanffy model followed by the Gompertz and Logistic. The estimates of A were higher for males than for females. The highest estimates of parameter k (rate of maturity) for both females and males were, in decreasing order for the Logistic, Gompertz, and von Bertalanffy models. k values for female turkeys was higher than for males. The age at the point of inflection and body weight at the age of point of inflection varied with the model used. The largest values of TI and WI corresponded to the Logistic model. Between sexes, the largest TI and WI values corresponded to males. The best models to describe turkey growth were the von Bertalanffy and Gompertz models, because it presented the highest APE, R2 and AIC values.</p></div

Additions of host associations and new records of bat ectoparasites of the families Spinturnicidae, Nycteribiidae and Streblidae from Honduras

We captured mormoopids, phyllostomids, and vespertilionids in Honduras to collect bat ectoparasites. Two species of Spinturnicidae (Acari) are the first reports of this family in Honduras. One species of Basilia Miranda Ribeiro, 1903, and four of Streblidae are recorded for the first time in Honduras. With these results, the current species number of each family for Honduras are two species of Spinturnicidae, three of Nycteribiidae, and 48 of Streblidae. We compared the number of species of Streblidae and bats in Honduras to highly sampled countries in Central and South America. Clearly, more effort is still needed in Honduras, although this is the third attempt to study the bat ectoparasites in Honduras

Comparing body condition score and FAMACHA© to identify hair-sheep ewes with high faecal egg counts of gastrointestinal nematodes in farms under hot tropical conditions

Data from a targeted selective treatment (TST) survey in three sheep farms was used to compare body condition scores (BCS) ≤ 2 and FAMACHA© scores ≥4 or ≥3 as criteria to identify ewes with ≥ 750 eggs per gram of faeces (EPG), and to confirm whether that EPG threshold allowed maintaining a large proportion of animals with no anthelmintic (AH) treatment. The survey included monthly data from all grazing adult ewes in three commercial farms. Farms 1 and 3 were surveyed for 11 months, and Farm 2 for 6 months, with a total of 7342 events recorded. Mean monthly population consisted of 330 ewes (Farm 1), 129 ewes (Farm 2) and 265 ewes (Farm 3). The FAMACHA© scores and BCS of adult ewes were recorded monthly. Ewes with FAMACHA© ≥ 4 or BCS ≤ 2 were faecal sampled to determine faecal egg counts (FEC) (2788 events). Ewes with ≥ 750 EPG were treated with an AH (658 events). The TST survey showed that BCS ≤ 2 was the best criteria to find ewes with FEC ≥ 750 EPG, with 1.1% false negatives. Meanwhile, FAMACHA© ≥4 or ≥3 failed to identify half of the events with ≥ 750 EPG (50–55% false negatives). Thus, the TST scheme could focus on screening ewes with BCS ≤ 2, and the FEC of those animals can avoid unnecessary AH treatments. The TST scheme was easier to implement at the farm with largest ratio of ewes with BCS > 2, as fewer ewes were sampled and treated, compared to farms where many ewes had BCS ≤ 2. In the surveyed farms a threshold of ≥ 750 EPG resulted in 63.5% of all ewes maintained with no AH treatment for the duration of the survey.Los datos de una encuesta de tratamiento selectivo dirigido (TST) en tres granjas de ovejas se usaron para comparar puntajes de condición corporal (BCS) ≤ 2 y puntajes de FAMACHA © ≥4 o ≥3 como criterios para identificar ovejas con ≥ 750 huevos por gramo de heces (EPG) ), y para confirmar si ese umbral de EPG permitió mantener una gran proporción de animales sin tratamiento antihelmíntico (AH). La encuesta incluyó datos mensuales de todas las ovejas adultas que pastan en tres granjas comerciales. Las granjas 1 y 3 fueron encuestadas durante 11 meses, y la granja 2 durante 6 meses, con un total de 7342 eventos registrados. La población mensual promedio consistió en 330 ovejas (Granja 1), 129 ovejas (Granja 2) y 265 ovejas (Granja 3). Los puntajes FAMACHA © y BCS de ovejas adultas se registraron mensualmente. Las ovejas con FAMACHA © ≥ 4 o BCS ≤ 2 se tomaron muestras fecales para determinar el recuento de huevos fecales (FEC) (2788 eventos). Las ovejas con ≥ 750 EPG fueron tratadas con un AH (658 eventos). La encuesta TST mostró que BCS ≤ 2 fue el mejor criterio para encontrar ovejas con FEC ≥ 750 EPG, con 1.1% de falsos negativos. Mientras tanto, FAMACHA © ≥4 o ≥3 no pudieron identificar la mitad de los eventos con ≥ 750 EPG (50-55% de falsos negativos). Por lo tanto, el esquema TST podría centrarse en la detección de ovejas con BCS ≤ 2, y la FEC de esos animales puede evitar tratamientos innecesarios de AH. El esquema TST fue más fácil de implementar en la granja con la mayor proporción de ovejas con BCS> 2, ya que se muestrearon y trataron menos ovejas, en comparación con las granjas donde muchas ovejas tenían BCS ≤ 2. En las granjas encuestadas resultó un umbral de ≥ 750 EPG en el 63.5% de todas las ovejas mantenidas sin tratamiento AH durante la duración de la encuesta