Are foreigners the vectors of Contagion? A study of six emerging markets

We investigate for the role of Foreigners, Local Institutions and Local individuals in days of Contagion in a set of six emerging markets from 2007 to 2016. We propose a new and intuitive continuous measure of Contagion based on the probability of a coincidence of daily negative returns in both the S&P500 and the local index, in excess of what can be explained by fundamentals. Using a VAR setting, we find that Foreigners sells induce Contagion, and that they keep selling in the following days. We also find evidence of Foreigners acting as the transmitters of large drops in the US stock market to emerging ones. Institutions also contribute to Contagion days with net sales, but they become net buyers from the day after. Finally, individuals are net buyers in Contagion days

Experimental antibiotic treatment identifies potential pathogens of white band disease in the endangered Caribbean coral Acropora cervicornis

Coral diseases have been increasingly reported over the past few decades and are a major contributor to coral decline worldwide. The Caribbean, in particular, has been noted as a hotspot for coral disease, and the aptly named white syndromes have caused the decline of the dominant reef building corals throughout their range. White band disease (WBD) has been implicated in the dramatic loss of Acropora cervicornis and Acropora palmata since the 1970s, resulting in both species being listed as critically endangered on the International Union for Conservation of Nature Red list. The causal agent of WBD remains unknown, although recent studies based on challenge experiments with filtrate from infected hosts concluded that the disease is probably caused by bacteria. Here, we report an experiment using four different antibiotic treatments, targeting different members of the disease-associated microbial community. Two antibiotics, ampicillin and paromomycin, arrested the disease completely, and by comparing with community shifts brought about by treatments that did not arrest the disease, we have identified the likely candidate causal agent or agents of WBD. Our interpretation of the experimental treatments is that one or a combination of up to three specific bacterial types, detected consistently in diseased corals but not detectable in healthy corals, are likely causal agents of WBD. In addition, a histophagous ciliate (Philaster lucinda) identical to that found consistently in association with white syndrome in Indo-Pacific acroporas was also consistently detected in allWBDsamples and absent in healthy coral. Treatment with metronidazole reduced it to below detection limits, but did not arrest the disease. However, the microscopic disease signs changed, suggesting a secondary role in disease causation for this ciliate. In future studies to identify a causal agent ofWBDvia tests of Henle–Koch’s postulates, it will be vital to experimentally control for populations of the other potential pathogens identified in this study

New records of hunting ants (Poneroids and Ectatomminoids) in the northern part of the Colombian Orinoquia region

Nous registres de formigues caçadores (Poneroides i Ectatomminoides) al nord de l’Orinòquia Colombiana. Es van revisar 466 espècimens de formigues caçadores recol·lectades en ambients de sabana inundable i boscos a la zona rural del municipi d’Arauca (Arauca, Colòmbia). En vuit zones de bosc amb grandàries de 0,25 a 220 ha es va situar un transsecte lineal amb set punts de mostreig separats per 20 m amb una superfície de 10 m2 cadascun. En cada punt de mostreig es van utilitzar tres tipus de tècniques: una trampa de caiguda per 24 hores, una mostra d’1 m2 de fullaraca processada en sac mini Winkler i la captura directa. Es van registrar 15 espècies, entre les quals el gènere més divers va ser Neoponera, amb sis espècies, seguit d’Odontomachus, amb dues espècies i Ectatomma, Anochetus, Gnamptogenys,Prionopelta, Pseudoponera, Pachycondyla i Thaumatomyrmex, amb una sola espècie cadascun. En aquest estudi s’amplia la distribució geogràfica de 15 espècies per al nord de l’Orinòquia colombiana i es registra per primera vegada la presència de Thaumatomyrmex cf. mutilatus a Colòmbia. Dades publicades a GBIF i a SiB Colombia (doi: 10.15472/vp8v42).Nuevos registros de hormigas cazadoras (Poneroides y Ectatomminoides) en el norte de la Orinoquia Colombiana. Se revisaron 466 especímenes de hormigas cazadoras recolectadas en ambientes de sabana inundable y bosques en la zona rural del municipio de Arauca (Arauca, Colombia). En ocho zonas de bosque con tamaños de entre 0,25 y 220 ha se ubicó un transecto lineal con siete puntos de muestreo separados por 20 m con una superficie de 10 m2 cada uno. En cada punto de muestreo se utilizaron tres tipos de técnicas: una trampa de caída por 24 horas, una muestra de 1 m2 de hojarasca procesada en saco mini Winkler y la captura directa. Se registraron 15 especies siendo el género más diverso Neoponera, con seis especies, seguido de Odontomachus, con dos especies, y Ectatomma, Anochetus, Gnamptogenys, Prionopelta, Pseudoponera, Pachycondyla y Thaumatomyrmex, con una sola especie cada uno. En este estudio se amplía la distribución geográfica de 15 especies para el norte de la Orinoquia colombiana y se registra por primera vez la presencia de Thaumatomyrmex cf. mutilatus en  Colombia. Datos publicados en GBIF y en SiB Colombia (doi: 10.15472/vp8v42).We reviewed 466 specimens of hunting ant species collected in flooded savanna environments and their adjacent forest fragments in the rural area of Arauca municipality (Arauca, Colombia). Samples were taken from eight forest fragments with sizes between 0.25 and 220 ha. In each location we set linear transects with seven sampling points separated by 20 m. In each sampling point we used three capture methods: a pitfall trap (left 24 hours), a sample of 1m2 of soil and litter to be processed with a mini Winkler extractor, and direct capture. Fifteen species were recorded; the most diverse genus was Neoponera with six species, followed by Odontomachus with two species and Ectatomma, Anochetus, Gnamptogenys, Prionopelta Pseudoponera, Pachycondyla and Thaumatomyrmex each with one species. This study extends the geographical distribution of 15 hunting ant species to the northern part of the Colombian Orinoquia region and documents for the first time the presence of Thaumatomyrmex cf. mutilatus in Colombia. Data published through GBIF and SiB Colombia (doi: 10.15472/vp8v42)

Effects of Mergers and Acquisitions on Shareholder Wealth: Event Study for Latin American Airlines

This study analyzes the effectof changes in corporate controlon the way shareholdersbenefit from the announcements of selling and buying airlines, thus contributing to the literature on mergers and acquisitions (M&As) in emerging markets. Using a methodologyof event study, including GARCH and OLS models, we find evidence that some selling companies obtain abnormal returns that are statisticallysignificant after the announcement of the M&A. However, when the merger is not strategic, the companies present statisticallysignificant negative abnormal returns. The resultsare not conclusive when analyzing the effecton the valueof the buying companies

Calidad de mercado y reformas al sistema transaccional. El Caso de X-Stream en el Mercado accionario colombiano

Se estima el efecto de la implementación de la plataforma transaccional X-Stream en la calidad de mercado accionario colombiano en Febrero de 2009. En particular se estudia el efecto en medidas de liquidez, (margen oferta-demanda e impacto en el precio), volatilidad diaria e intradiaria, y actividad bursátil, empleando modelos econométricos de prueba de medias, panel datos y varianza condicional. Para este fin se usa una base de datos de órdenes y transacciones provistas por BVC. La evidencia muestra que X-Stream mejoró la calidad del mercado accionario colombiano, otorgándole mayor liquidez, y menor volatilidad al mercado en general y a la mayoría de acciones de alta liquidez. Esta evidencia se constituye en un argumento a favor de las inversiones en modernización de los sistemas transaccionales en los mercados emergentes.We estimate the effect of the new trading system, X-Stream, on the market quality of the Colombian Stock Exchange on February 2009. We test the effect on liquidity measures (bid-ask margin and price impact), daily and intraday volatility and trading activity, using mean tests, panel data and conditional variance models. We use a proprietary database of transactional and order data from the exchange. The evidence is consistent with X-Stream improving liquidity and reducing volatility in the overall market and on most of the most liquid stocks. These results support the investment on more sophisticated trading systems in Emerging Markets