We examined the food habits of coyotes (Canis latrans) from the Pico de Orizaba National Park by analyzing 136 scat samples that were collected for 11 months in a 7 km transect. Coyote diet consisted mainly of mammals (48.96%), plants (20.28%), birds (6.76%) and insects (0.68%). Our results indicate that annual coyote diet consisted of 15 prey-species. Their diet is based mainly on the rodent Peromyscus melanotis (25.68%), followed by the tomato plant Lycopersium esculentum (11.48%), and the jack rabbit Lepus callotis (9.46%). In the dry season, P. melanotis was the main prey item (29.16%), followed by L. callotis (8.33%). The most important items in the diet of coyotes in the rainy season were P. melanotis (22.36%) and L. esculentum (14.47%). There was no significant variation in prey consumption between seasons.

Updated information on the geographic and taxonomic representativeness of mammal specimens deposited in 28 Mexican mammal collections, the Mammal Networked Information System (MaNIS), and the Unidad de Informática para la Biodiversidad (UNIBIO) data bases were compiled in order to analyze and compare the overall current status of the specimens of Mexican mammals deposited in collections in North America. A total of 421,466 specimens deposited in 120 collections were documented, of which 233,116 were deposited in collections in the United States of America and Canada, and 188,350 in collections in Mexico. The collections with the greatest number of specimens from Mexico are the Colección Nacional de Mamíferos (CNMA 46,000), the University of Kansas (KU 44,301), and the Escuela Nacional de Ciencias Biológicas (ENCB 43,985). In Mexican collections, the states of northern Mexico are improperly represented in number of specimens (< 3,000), whereas in foreign collections, the states of central Mexico are poorly represented. The Mexican states better represented by number of specimens (> 10,000) are Baja California Sur, Chiapas, Oaxaca, Puebla and Veracruz. The orders better represented in terms of number of specimens are Rodentia and Chiroptera (234,978 and 120,956, respectively). The Mexican states with the smallest area have the greatest density of specimens collected (specimens/km 2 ), such as Distrito Federal (3.2), Tlaxcala (1.4), Colima (1.06), and Morelos (0.9). The aim of this analysis is to provide a baseline to establish appropriate strategies to complete the Nota del editor. Por considrar extensas las direcciones postales se decidio mandarlas al final de este articulo

The present paper analyzes the effect of low aluminum additions and the hot forging process on the microstructure and non-metallic inclusions of high manganese steels. Four high-manganese steels (HMnS) were obtained by adding low aluminum contents of 1.1 and 1.5 wt. % in four medium carbon austenitic steels (0.3 - 0.4 wt% C) with manganese contents of 17 and 22 wt. Samples of the as-cast steels were hot forged to 1100 ?C to obtain a whole reduction of 70 %. The microstructural evolution was studied by microscopy techniques (OM, and SEM-EDS) and X-Ray diffraction measurements for the as-cast and hot forged steels. A typical grain columnar zone obtained during solidification of an ingot casting was obtained in the as-cast condition where the microstructure was constituted by non-metallic inclusions in a fully austenitic matrix. The non-metallic inclusions were identified as Al2O3 and MnS particles. The thermomechanical treatment allows the formation of an austenitic microstructure characterized by twins in high manganese steels while a duplex austenitic-martensitic microstructure was obtained for HMnS which contained the lowest manganese contents. The highest tensile properties were obtained for the steel 17Mn-1Al which showed the lowest grain size and higher non-metallic inclusions content. The hardness values were similar to those obtained in the as-cast condition.

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In this research, aerodynamic tests were carried out using Solidworks Flow Simulation software on a Sedan-type car, implementing different sizes of lip-type spoilers at the rear to obtain the results of the drag and lift coefficients produced by movement. of the air regardless of the design at the rear of the car and analyze if there was improvement in aerodynamics. Analyzing the results, it is obtained that the aerodynamics of the car is improved when a lip-type spoiler is fitted, the lift forces were reduced, whereas the drag forces remained constant for all the different designs.