Identity as Liminality in Post-Colonial Fiction: Nadine Gordimer.’s The Pickup and Bessie Head.’s A Question of Power

This paper sets out to analyze the interstitial/liminal aspect of postcolonial literature as ciphered in the narratives of Nadine Gordimer and Bessie Head. A Question of Power and The Pickup both voice hybrid subjects in terms of race and gender, and thus represent the new epistemological space that this literature opens up. Focusing on the shifting identities of the female characters in these novels, we will establish a connection between the praxis of post-colonial writing as a continuous refocusing of cultural certainties and the relocation of the familiar in the uncanny. Este artículo pretende analizar el aspecto liminal de la literatura postcolonial tal y como se refleja en la narrativa de Nadine Gordimer y Bessie Head. A Question of Power y The Pickup articulan la voz de individuos híbridos en cuanto a raza y género, y, de este modo, representan el nuevo espacio epistemológico que esta literatura abre. Al centrarnos en las identidades variables de los personajes femeninos de estas novelas, trataremos de establecer una conexion entre la praxis de la literatura postcolonial como un continuo reajuste de certezas culturales y la reubicación de lo familiar en lo extraño

Visual Detection of Speckles in the Fish Xenotoca variata by the Predatory Snake Thamnophis melanogaster in Water of Different Turbidity

The results of this study suggest that speckles on male X. variata are visual signals to potential predators such as the snake T. melanogaster. However, speckles are not a determining factor; snakes display a higher frequency of predatory behavior toward the fish, but their predatory behavior is influenced by water turbidity. Turbidity is considered a constraint that affects foraging in aquatic predators such as the snake T. melanogaster because it is involved in the visual identification of potential prey and capture success. Further experiments are needed to test the direct influence of snake predation on variation in sexual traits, such as the number of speckles on the flanks of male X. variata. Therefore, natural selection caused by predation may constrain the development of sexually dimorphic traits in X. variata, as suggested by other studies showing that male secondary sexual traits often increase the risk of predationSemi-aquatic snakes integrate visual and chemical stimuli, and prey detection and capture success are therefore linked to the display of visual predatory behavior. The snake Thamnophis melanogaster responds preferentially to individuals of the fish Xenotoca variata with a greater number of bright, colorful spots (lateral speckles) compared with those with a smaller number; however, water turbidity can reduce underwater visibility and effect the vulnerability of fish. In this study, we tested whether the presence of iridescent speckles on the flanks of male X. variata interacted with water turbidity to modify the predatory behavior displayed by the snake T. melanogaster.We predicted that in an experimental laboratory test, the snakes would increase the frequency of their predatory behavior to the extent that the water turbidity decreases. The snakes were tested at six different levels of water turbidity, in combination with three categories of male fish (with few, a median number of, or many speckles). The results showed that in a pool with high or zero turbidity, the number of speckles is not a determining factor in the deployment of the predatory behavior of the snake T. melanogaster toward X. variata. Our findings suggest that snakes can view the fish at intermediate percentages of turbidity, but the number of speckles in male X. variata is irrelevant as an interspecific visual signal in environments with insufficient luminosity. The successful capture of aquatic prey is influenced by integration between chemical and visual signals, according to environmental factors that may influence the recognition of individual traits.Universidad Autónoma del Estado de México (2865/2010, 2663/2013, 3589/2013S

Temporal stability of an endemic Mexican treefrog

Changes in abundance and distribution of the three H. eximia age-sex categories, are related to seasonal variations in temperature and precipitation during the year. The ability of H. eximia to persist is constrained by human-induced habitat alterations of the temperate forest habitat in the CentralMexican Plateau. Small frog species, such as H. eximia, may be strongly disadvantaged by habitat fragmentation. The CentralMexican Plateau contains a major metropolitan area and 44.7% of this area is used for agriculture (CONAPO, 2010). This presents the possibility of a reduction in the suitability of existing habitat patches (i.e., fragments) which may affect both local and landscape-level pond-breeding amphibian population dynamics. Only temperate forest habitat seems to be suitable for H. eximia, therefore, conservation efforts should be directed to areas where suitable ecological variables are present and especially where human encroachment affects tree microhabitat. Most of what we know about this endemic treefrog comes from occasional captures of active animals. New studies are needed to better understand how the stability of a population of frogs relates to areas that are degraded by human land-use. For example, mark–recapture studies can elucidate terrestrial habitat requirements for local populations, genetic approaches may be used to infer gene flow, and to estimate dispersal and immigration. These types of studies will provide crucial information about the relative impact of land use on effective population size and reproductive success of local populationsThe demographic characteristics of an amphibian population fluctuate independently over time, mainly in response to the temporal variation of environmental factors, especially precipitation and temperature. These temporal fluctuations may contribute to the size of an amphibian population and could be used to determine the current conservation status of a species. During a five year (2004–2008) period, we studied the relative abundance, sex ratio, and age-sex structure of a population of metamorphosed individuals of the endemic treefrog Hyla eximia in CentralMexico. We also studied the species’ relationship with climatic variables such as temperature and precipitation.We found an interannual constant abundance during the study period. However, interannual differences were observed in the population structure by age-sex category (males, females, or juveniles), with decreased abundance of males and juveniles during the rainy months (August–November). The annual abundance of H. eximia was positively correlated with rainfall, but negatively with monthly temperature.We found the sex ratio was male-biased (2:1), except for year 2008. Also, differences in snout-vent length (SVL) were found between years, suggesting changes in recruitment of new individuals.We conclude that variations in abundance, and frequencies by age-sex category, of H. eximia are related to seasonal variations in temperature and precipitation characteristics of temperate zones. However, this temporal stability may suggest that anurans have an unusual capacity to persist even in the face of human-induced habitat change.Universidad Aut ´onoma del Estado de Mexico (2663/2013, 3589/2013SF)

Towards Conserving Crop Wild Relatives along the Texas–Mexico Border: The Case of Manihot walkerae

Walker’s Manihot, Manihot walkerae, is an endangered species endemic to south Texas and northeastern Mexico and is a Crop Wild Relative (CWR) of the international and economically important crop cassava (M. esculenta). Manihot walkerae is globally endangered (IUCN’s Redlist, Texas list, USA); however, it is not recognized on the Mexican list of endangered species (NOM-059-SEMARNAT). We assessed the status of M. walkerae in Mexico and re-evaluated its global status. According to our analysis, M. walkerae should be considered an endangered species based on the IUCN’s assessment method and a threatened species in Mexico based on the Mexican criteria. Our findings encourage the establishment of sound conservation plans for M. walkerae along the Texas–Mexico border. View Full-Tex

Noves cites i nous hostes d'Andricus sphaericus Pujade-Villar, 2016 (Hymenoptera: Cynipidae)

Andricus sphaericus Pujade-Villar, 2016 és una espècie que va ser coŀlectada per primer cop en 2011 i posteriorment en 2014 sobre Quercus rugosa Née i Q. obtusata Humb. & Bonpl. (secció Quercus, Fagaceae) a l'Estat de México i al DF, i que ha estat recentment descrita (Pujade-Villar et al., 2016). Coŀlectes realitzades pels coautors mexicans en 2015 (entregades al primer autor el juliol d'aquest any) i coŀlectes realitzades aquesta anualitat pel primer autor aporten noves dades d'aquesta espècie, amplien l'ària de distribució i es citen per primer cop gèneres d'inquilins i parasitoids

Potential Effects of Climate Change on the Geographic Distribution of the Endangered Plant Species Manihot walkerae

Walker’s Manihot, Manihot walkerae, is an endangered plant that is endemic to the Tamaulipan thornscrub ecoregion of extreme southern Texas and northeastern Mexico. M. walkerae populations are highly fragmented and are found on both protected public lands and private property. Habitat loss and competition by invasive species are the most detrimental threats for M. walkerae; however, the effect of climate change on M. walkerae’s geographic distribution remains unexplored and could result in further range restrictions. Our objectives are to evaluate the potential effects of climate change on the distribution of M. walkerae and assess the usefulness of natural protected areas in future conservation. We predict current and future geographic distribution for M. walkerae (years 2050 and 2070) using three different general circulation models (CM3, CMIP5, and HADGEM) and two climate change scenarios (RCP 4.5 and 8.5). A total of nineteen spatially rarefied occurrences for M. walkerae and ten non-highly correlated bioclimatic variables were inputted to the maximum entropy algorithm (MaxEnt) to produce twenty replicates per scenario. The area under the curve (AUC) value for the consensus model was higher than 0.90 and the partial ROC value was higher than 1.80, indicating a high predictive ability. The potential reduction in geographic distribution for M. walkerae by the effect of climate change was variable throughout the models, but collectively they predict a restriction in distribution. The most severe reductions were 9% for the year 2050 with the CM3 model at an 8.5 RCP, and 14% for the year 2070 with the CMIP5 model at the 4.5 RCP. The future geographic distribution of M. walkerae was overlapped with protected lands in the U.S. and Mexico in order to identify areas that could be suitable for future conservation efforts. In the U.S. there are several protected areas that are potentially suitable for M. walkerae, whereas in Mexico no protected areas exist within M. walkerae suitable habitat

Predicting the Impact of Climate Change on the Distribution of Rhipicephalus sanguineus in the Americas

Climate change may influence the incidence of infectious diseases including those transmitted by ticks. Rhipicephalus sanguineus complex has a worldwide distribution and transmits Rickettsial infections that could cause high mortality rates if untreated. We assessed the potential effects of climate change on the distribution of R. sanguineus in the Americas in 2050 and 2070 using the general circulation model CanESM5 and two shared socioeconomic pathways (SSPs), SSP2-4.5 (moderate emissions) and SSP2-8.5 (high emissions). A total of 355 occurrence points of R. sanguineus and eight uncorrelated bioclimatic variables were entered into a maximum entropy algorithm (MaxEnt) to produce 50 replicates per scenario. The area under the curve (AUC) value for the consensus model (\u3e0.90) and the partial ROC value (\u3e1.28) indicated a high predictive capacity. The models showed that the geographic regions currently suitable for R. sanguineus will remain stable in the future, but also predicted increases in habitat suitability in the Western U.S., Venezuela, Brazil and Bolivia. Scenario 4.5 showed an increase in habitat suitability for R. sanguineus in tropical and subtropical regions in both 2050 and 2070. Habitat suitability is predicted to remain constant in moist broadleaf forests and deserts but is predicted to decrease in flooded grasslands and savannas. Using the high emissions SSP5-8.5 scenario, habitat suitability in tropical and subtropical coniferous forests and temperate grasslands, savannas, and shrublands was predicted to be constant in 2050. In 2070, however, habitat suitability was predicted to decrease in tropical and subtropical moist broadleaf forests and increase in tropical and subtropical dry broadleaf forests. Our findings suggest that the current and potential future geographic distributions can be used in evidence-based strategies in the design of control plans aimed at reducing the risk of exposure to zoonotic diseases transmitted by R. sanguineus

Ants of Mexico: Distribution and species richness in environments with varying levels of human impact

Anthropogenic disturbance, primarily driven by land-use changes, has caused alterations in ecosystems and biodiversity, including the ant community. Therefore, the aim of this study was to analyse the current landscape of ant species richness and distribution in environments with varying degrees of disturbance in Mexico. Additionally, we sought to identify ant species of ecological, economic and health significance within the country.The present study shows that Mexico has a total of 33,286 records of 1,104 ant species belonging to 10 subfamilies. These species were recorded in a wide variety of environments with different levels of human impact. It was observed that both highly-disturbed environments and undisturbed environments had the highest number of ant records. In undisturbed environments, greater species richness was recorded, with a total of 704 species. Furthermore, the most representative ant species for the country were identified in ecological, economic and human health contexts. Within these species, a group composed of four exotic species (Tapinoma melanocephalum, Paratrechina longicornis, Wasmannia auropunctata and Linepithema humile) deserves special attention, as they have achieved extensive dispersion throughout the country and have been associated with negative impacts in ecological, economic and human health realms

A new genus of oak gall wasp, Striatoandricus Pujade-Villar (Hyenoptera: Cynipidae: Cynipini) from Americ with descriptions of two new Mexican species

A new genus of cynipid oak gall wasp, Striatoandricus Pujade-Villar (Hymenoptera: Cynipidae: Cynipini), is described. Striatoandricus gen. nov. includes four previously described species, Andricus nievesaldreyi n. comb., A. georgei n. comb., A. maesi n. comb., and A. barriosi n. comb., which induce pubescent leaves or twig galls on Quercus belonging to Quercus section. Two new species from México are also described: S. cuixarti Pujade-Villar n. sp. and S. sanchezi Pujade-Villar n. sp. in Quercus section. Descriptions of the genus and diagnostic characters, including DNA sequence data, are presented. This new genus is supported by both morphological and molecular data

Diversidad y zoogeografía de los moluscos terrestres de la sierra de Tamaulipas, México

Diversity and biogeography of Mexican terrestrial gastropods is poorly known. The terrestrial mollusks of the Sierra of Tamaulipas were surveyed from October 1988 to November 2005. A total of 482 samples were obtained from 30 localities, characterized with different vegetation types. Thirty-one genera and 46 species belonging to 18 families are recorded. The primary zoogeographical relationships are characterized by the presence of neotropical and neartic affinities (17 species: 37%) and the endemic taxa (11 species: 24%). The family Spiraxidae has the largest number of endemic species (6). The biogeographical value in this area is 3.78.La diversidad y biogeografía de los moluscos terrestres mexicanos es pobremente conocida. Entre octubre de 1988 y noviembre de 2005 fueron estudiados los gastrópodos terrestres de la Sierra de Tamaulipas, obteniéndose 482 muestras de 30 localidades en diferentes tipos de vegetación. Se registraron 31 géneros y 46 especies pertenecientes a 18 familias. La diversidad malacológica es mayor a la de otras áreas naturales de importancia para la conservación en México. Las principales afinidades zoogeográficas son la neotropical principalmente y neártica de 17 especies (37% de la malacofauna) y el endemismo de 11 especies (24%). La familia con mayor número de especies endémicas es Spiraxidae con seis. El valor biogeográfico promedio es de 3.78