Adaptive evolution via a major gene effect: Paedomorphosis in the Mexican axolotl

Although adaptive evolution is thought to depend primarily on mutations of small effect, major gene effects may underlie many of the important differences observed among species in nature. The Mexican axolotl (Ambystoma mexicanum) has a derived mode of development that is characterized by metamorphic failure (paedomorphosis), an adaptation for an entirely aquatic life cycle. By using an interspecific crossing design and genetic linkage analysis, a major quantitative trait locus for expression of metamorphosis was identified in a local map of amplified fragment length polymorphisms. These data are consistent with a major gene hypothesis for the evolution of paedomorphosis in A. mexicanum.

Mexican papita viroid: putative ancestor of crop viroids.

The potato spindle tuber disease was first observed early in the 20th century in the northeastern United States and shown, in 1971, to be incited by a viroid, potato spindle tuber viroid (PSTVd). No wild-plant PSTVd reservoirs have been identified; thus, the initial source of PSTVd infecting potatoes has remained a mystery. Several variants of a novel viroid, designated Mexican papita viroid (MPVd), have now been isolated from Solanum cardiophyllum Lindl. (papita güera, cimantli) plants growing wild in the Mexican state of Aguascalientes. MPVd's nucleotide sequence is most closely related to those of the tomato planta macho viroid (TPMVd) and PSTVd. From TPMVd, MPVd may be distinguished on the basis of biological properties, such as replication and symptom formation in certain differential hosts. Phylogenetic and ecological data indicate that MPVd and certain viroids now affecting crop plants, such as TPMVd, PSTVd, and possibly others, have a common ancestor. We hypothesize that commercial potatoes grown in the United States have become viroid-infected by chance transfer of MPVd or a similar viroid from endemically infected wild solanaceous plants imported from Mexico as germplasm, conceivably from plants known to have been introduced from Mexico to the United States late in the 19th century in efforts to identify genetic resistance to the potato late blight fungus, Phytophthora infestans.

Manifest of the cargo on board the Brig William, 1791 October

Handwritten manifest listing ship cargo for a voyage of Brig William.

The pragmatics of computer-mediated communication between South African and Mexican drug traffickers

South Africa and Mexico are ripe with drug trafficking. The gangs and syndicates running the drug businesses in these two countries collaborate occasionally. Communication between these international drug business partners takes place on social media. Their main language of communication is English, mixed with some limited use of Spanish and Afrikaans. The key purpose of the interactions between the South African and Mexican parties is the organisation of their business activities. This study aims at examining how the drug traffickers position each other and themselves regarding their common business interest and how their relationship evolves throughout their interactions. Moreover, it is of interest to look at how these people make use of different social media and their affordances. For this a qualitative analysis of the interaction between two drug traffickers (one South African and one Mexican) on Facebook, Threema and PlayStation 4 was performed. Computer-mediated communication between these two main informants was studied at various stages of their relationship. Results show that at first the interaction between the South African and Mexican drug traffickers consists of interpersonal negotiations of power. The high risk of the drug business and gang/syndicate membership paired with intercultural frictions causes the two interlocutors to be extremely cautious and at the same time to mark their position. As their relationship develops and they gain trust in each other a shift to interpersonal negotiations of solidarity takes place. In these discursive practices diverse linguistic strategies are employed for creating relational effects and for positioning the other and the self. The discursive activities of the interactants are also identity practices. Thus, the two drug traffickers construct identities through these social practices, positioning and their interpersonal relationship.

Viva la Raza : Mexican American education, a search for identity.

"Reprints from American Education."

Opals from a Mexican mine.

The greatest of the Gods is Quetzalcoati.--The water lady.--The mysterious disappearance of Mrs T. Tompkins Smith.--The vision of Don Juan on the Piedra de los Angeles.--Cosmopolitana mexicana.

Alegatos que presentan ante la Suprema Corte de Justicia de la Nación las siguentes compañías y personas, Compañía Transcontinental de Petróleo S.A., International Petroleum Company, Huasteca Petroleum Company, Tuxpan Petroleum Company, Compañía Mexicana de Petróleo S.A., Tamiahua Petroleum Company, Señores Doheny & Bridge, The Texas Company of México, La Atlántica, New England Fuel Oil Company, Pánuco-Boston Oil Company, Mexican Gulf Oil Company, Continental Mexican Petroleum Company, Gompañía [sic] de Petróleo "La Corona", Compañía Petrolera Tal Vez, Compañía Terminal de Productores, Scotish [sic] Mexican Oil Company, Charles F. de Ganahl, El Azadón Company, Soledad Oil Company, Piedras Development Company, Tancochin Oil Company, Lot Seventeen, Malcon Anderson Company, George L. Christie, Seabord Fuel Company, Tamalin Oil Company, Juanedo Oil Company, Compañía Indiana y El Tigre, Compañía Agrícola Pretrolera [sic] Mexicana, Compañía

Mode of access: Internet.