Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Las reseñas bibliográficas no contempla resumen.

Las reseñas bibliográficas no contempla resumen.

In 1849 the U.S. Naval Astronomical Expedition, headed by Lieutenant James Melville Gilliss, arrived in Chile with the mission to register observations that, triangulated with those carried out in the northern hemisphere, would allow the measurement of the solar parallax. For three years, the members of this expedition studied the stars, but also the geography, geology, weather, flora, fauna, society, history and the economy of Chile, all of which was registered in the six volumes of the expedition’s report. In this article we consider this expedition as a case study of the dynamics of scientific practice that were put forward during the middle of the nineteenth century. We are particularly interested in observing the expedition as an example of the configuration of a local scientific platform that responded to transnational interests, and also as a transition from an enlightened comprehension of natural history to a modern understanding of the disciplined sciences.

The perspective from which the anarchists of the Mexican Liberal Party (PLM) have been analyzed has placed them only within the context of the Mexican Revolution resulting in their classification as socialists, reformers, patriots and even as a base for syndicalism. This article shows that the intentions of the PLM do not coincide with the nationalist image where official and hagiographic historiography have placed them. Based on statements published in Regeneración, we show that they did not intend to fight for socialism, were not patriots or struggled for the reforms attributed to them in the following years. Their struggle to achieve anarchy was marginalized from official speeches or was diluted in the claim to “clean” the image, especially of Ricardo Flores Magón, who was planned to be erected as a patriot.

Euphausiids migrate vertically in the water column as part of their diel cycle. These migrations make them a key element in the biological pump of the pelagic environment. We took stratified zooplankton samples (0-50, 50-100, and 100-150 m) during the Pacífico-ERFEN campaign in September 2012 to evaluate the vertical distribution of euphausiids around Malpelo Island (3.8 - 4.2 N, 81.4 - 81.8 W). A total of 10 species belonging to four genera were identified. Euphausia diomedeae was the most abundant species in the 0-50 and 100-150 m layers, whereas E. distinguenda was the most abundant species in the 50-100 m layer. Based on quasi-Poisson generalized linear distribution models we found that abundance in the 50-100 m layer was significantly higher than in the 100-150 m layer (t = 3.05, p < 0.05). There were no significant differences associated with sampling hour (diurnal/nocturnal) (t = 0.07, p = 0.94). We calculated a vertical distribution index (VDI) based on abundance, which showed that euphausiid species were concentrated in the 50-100 m layer during day and night. Calyptopis larvae dominated in abundance at all depth layers, followed by furcilia larvae, juveniles and adults. The abundance of the latter increased gradually from the most superficial layer to the deepest layer, whereas juveniles showed the opposite pattern. This is the first study to describe the taxonomic composition, and vertical and spatial distribution of euphausiids associated with Malpelo Island, Colombian Pacific.

Socio-ecological and conservation aspects of a small community of bottlenose dolphins Tursiops truncatus (Odontoceti: Delphinidae) in Santa Elena, Ecuador. A resident community of bottlenose dolphins (Tursiops truncatus) has been studied irregularly between 2005 and 2018 around the tip of the Santa Elena Peninsula, Ecuador (2°11'S, 81°0.7'W). Opportunistic sightings and systematic surveys from the beach and at sea from a boat were carried out along 40 km of coast, accounting for 917.2 km of tracking by car from land and 707.4 km of boat tracking by sea. Average group size was 5.31 dolphins/group (SD= 1.97, range 1-10), with no significant changes throughout the study period. From land, however, the group size was underestimated 32% on the average. This small dolphin community currently has only nine individuals, including six adults, one immature and two calves. The relative abundance ranged between 0.03 dolphins/km in the northwestern part and 0.32 dolphins/km in the south, where dolphins concentrate their activities, possibly because human activities are less intense. Dolphins were generally distributed in the first 200 m from the shore, reaching up to 1,200 in the northern shallower part and where port and tourist activities concentrate. The dolphins’ speed was significantly higher when they were followed from a boat at close range (5.87 km/h) than when they were monitored from the beach (2.9 km/h) (P < 0.01), which suggests that boat tracking had an effect on dolphin´s movements. Pairwise cluster analysis showed that animals from this community show high rates of association among each other (average 0.67, range 0.01-1.0), indicating this is highly cohesive population unit. Dolphins also showed high level of residence (average occurrence index = 0.62). During the study, two main threats were identified, a gillnet fishery in the southwestern part and an intense fishing boat traffic in the northwestern. This coastal bottlenose dolphin community is the smallest of this species ever reported in the Gulf of Guayaquil, probably is a remnant of a larger population that would be in process of extinction. Most of the study area is currently part of a coastal-marine protected area created in 2008, which offers an opportunity for the recovery and conservation of this dolphin community. Given the fragility of this population unit, we recommend to environment authorities addressing potential threats by eliminating gillnets, implementing an exclusion zone for fishing gear and fishing boat traffic of 1 km width from the shore and limit the speed of any type of vessel to 10 knots within the reserve.

Land-use change from native forests to agriculture, livestock and exotic forest plantations is a main factor affecting riparian vegetation and aquatic communities. The aim of this study was to assess responses of aquatic macroinvertebrate assemblages to riparian cover change in Murocomba protective forest, Valencia, Ecuador. Aquatic macroinvertebrates were collected and physicochemical variables were measured during dry (June-October 2014) and rainy (December-April 2015) seasons along three creeks with different riparian cover: native forests Q1-CBN, pasture for agricultural and livestock activities Q2-CAG, and exotic forest plantations Q3-CPF. According to the Macroinvertebrate Family Biotic Index (FBI) and the Biological Monitoring Working Party Index (BMWP/Col) the best conditions existed in the creek Q1-CBN, while the Ephemeroptera, Plecoptera and Trichoptera Index (EPT) decreased in the creek Q2-CAG during the rainy season. The Shannon-Weaver index showed higher values in Q1-CBN and Q3-CPF in the dry period, and the dominance increased in the Q3-CPF in rainy season. A total of 6 583 macroinvertebrates were collected. Trichoptera was the most abundant order and Hidropsychidae the most abundant family. The Coleoptera order showed greater abundance in Q1-CBN and Diptera in Q2-CAG, while Hemiptera showed the lowest abundance in Q3-CPF. Psephenidae, Chironomidae, Leptophlebiidae, Veliidae, Simuliidae, Baetidae and Leptohyphidae were associated with the highest values of total dissolved solids and pH, as well as higher values of IBF and lower values of EPT, BMWP, and depth of the channel in Q2-CAG, whereas Leptoceridae, Elmidae, Ptilodactylidae and Philopotamidae were associated with higher values of EPT, BMWP and depth of the channel in Q1-CBN and Q3-CPF. A negative influence of anthropic activities on the physicochemical variables and structure of the macroinvertebrate assemblages was evidenced. This indicates that the riparian vegetation is a factor that determines the establishment and structure of aquatic communities.

Toxoplasma gondii is a protozoan parasite recognized as the causative agent of toxoplasmosis, a zoonotic disease that affects humans and domestic or wild animals. In Mexico, it represents a public and animal health problem, especially in regions with tropical and subtropical climates. Bats have been reported as accidental hosts in the transmission cycle; however, there is no preceding information in Mexico. Therefore, the aim of the present study is to report the T. gondii infection in bats captured in sites of Campeche and Yucatan states, Mexico. Bats were captured in two sites in Yucatan (X’matkuil and Panaba) and one in Campeche (Hampolol), located in the Yucatan Peninsula. Kidneys, spleen, and liver were collected and used in the total DNA extraction. Toxoplasma gondii infection was detected through the amplification of a B1 gene fragment, using nested PCR. The positive PCR products were purified and sent to sequencing for a posterior sequence identity analysis. Additionally, a phylogenetic tree was made. A total of 69 bats belonging to eight different species were processed: 41 (59.4 %, 41/69) Artibeus jamaicensis; six (8.7 %, 6/69) Pteronotus parnellii; six (8.7 %, 6/69) Noctilio leporinus; six (8.7 %, 6/69) Chiroderma villosum; four (5.8 %, 4/69) Glossophaga soricina; two (2.9 %, 2/69) Carollia sowelli; two (2.89 %, 2/69) Artibeus lituratus; and two (2.9 %, 2/69) Rhogeessa aeneus. The nested PCR identified eight (11.6 %, 8/69) infected bats: six (75 %, 6/8) A. jamaicensis, captured in X'matkuil and Panaba, one (12.5 %, 1/8) G. soricina, and one (12.5 %, 1/8) C. villosum, both captured in Panaba. The alignment analysis yielded 99-100 % for cover and 97-99 % for identity to T. gondii sequences. Our results contribute to the understanding of the T. gondii transmission cycle in the region; however, future research is needed to determine circulating genotypes, as previous studies have demonstrated that these animals might be infected with identified genotypes in other domestic or wild animals and even in humans.

Sperm kinematics and morphometric subpopulations analysis with CASA systems: a review. The subjective evaluation of seminal quality has given way to the use of objective assessment techniques by CASA technology (computer-assisted semen analysis). The application of principal components (PC) and clustering methods to reveal subpopulations of spermatozoa is a powerful tool to evaluate raw semen and processed cell suspensions, but not many researchers are aware of the technique. PC analysis is a multivariate statistical method that reduces the number of variables used in subsequent calculations used to describe the data. By integrating the original variables according to their coherence in a database into a new complex mathematical variable, clearly defined homogenous subpopulations of spermatozoa can be defined. Kinematic, morphometric, morphological or DNA integrity tests may apply to characterize it and understand the reproductive biology of the spermatozoon. In recent years there has been a substantive change in the conceptual paradigm regarding what an ejaculate is. It should be said that until recently it was considered that the representative population (billions) of sperm was made up of "equivalent" cells with a common goal: to be the one that could finally fertilize the oocyte. The verification that the set of spermatozoa is grouped in distinct subpopulations, according to their kinematic and morphometric characteristics, opens the way towards a more cooperative vision. Besides, we have seen that the subpopulation distribution is different among males, which seems to indicate different strategies that can be understood within another paradigm, that of sperm competition between different ejaculates. The existence of heterogeneous subpopulations of spermatozoa in the ejaculate that show kinematics and morphometric patterns is widely known but the biological meaning of these different sperm subpopulations is still not clear. Although the role of the different subpopulations remains unknown, the work should continue in that direction.

This article is a bibliographic review on the ecological functions that distinguish bamboos, for which they deserve greater recognition and inclusion in ecological restoration programs. Bamboos are a highly diverse, geographically widespread and economically important plant group. Although they are more recognized by commercial uses, their potential for use in ecological restoration programs is promising, as they can be effective in delivery of several environmental services related to soil, water and carbon sequestration. Their rapid growth, along with their abilities to control erosion and maintain water at soil level, as well as provide nutrients by litterfall decomposition, make them a valuable group for recovery of degraded areas and in productive restoration of ecosystems, in particular via agroforestry systems. Agroforestry approaches can combine different bamboo species with other crops, to meet human needs while generating benefits for ecosystems. Similarly, bamboo forests or plantations together with mixed agroforestry systems can act as stepping-stones and biological corridors, in very fragmented landscapes by providing shelter and food for a wide diversity of organisms. Despite perceptions that bamboos can be invasive, evidence to support this is limited. We recommend careful evaluation of the biological characteristics of bamboo species selected, prior to deployment in productive restoration projects and for the recovery of environmental services.