287 research outputs found

    Osteología craneal del subgénero Catemaco género Bramocharax (Teleostei: Characidae): relaciones Filogenéticas y Biogeografía

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    Tesis (Doctor en Ciencias BiolĂłgicas con Especialidad en ZoologĂ­a) U.A.N.L.UANLhttp://www.uanl.mx

    A new cryptic species of Leberis Smirnov, 1989 (Crustacea, Cladocera, Chydoridae) from the Mexican semi-desert region, highlighted by DNA barcoding

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    DNA barcoding, based in the sequence of a gene from the mitochondria, the Citochrome C oxidase (CO1), has been proved to be an excellent tool to identify many animal groups from invertebrates to vertebrates. After barcode several Cladocera, we gathered evidence about the existence of two Leberis species in the north of Mexico. Minimal CO1 divergence between both taxa was 14.3%, due to the GC% in the third codon position. A detailed morphological analyses uncovered one of the species as L. davidi, dwelling from South America to Mexico and the other as Leberis chihuahuensis new species, apparently restricted to semi-desert temporary pools. The parthenogenetic female of the latter is characterized by a small size, blunt rostrum, long and curved spine in the first exopodal segment of the second antenna, absence of accessory seta and sensilla in the first thoracic limb, and a brush-shaped seta in the fourth limb, among other characters. Males have a long and narrow postabdomen and a series of similar sized spinules in the posterior margin of the valves. By the first time a cladoceran is described from both views, the morphology and CO1 sequence

    Descripción del cráneo de Bramocharax caballeroi Contreras & Rivera 1985 (Pisces, Characidae), pez endémico del Lago de Catemaco, Veracruz, México.

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    The Bramocharax genus is distributed from Central America to Mexico. Until now the species known are Bramocharax bransfordi collected in Nicaragua and Costa Rica, B. dorioni and B. baileyi from Guatemala and B. caballeroi from Catemaco Lake, Veracruz, Mexico. The aim of this work is to realize a detailed description of the skull for Bramocharax caballeroi from the analysis of 37 different topotypes. The skull of this species has 58 osteological elements, 49 of them coupled. Shape is oval in lateral view, because the bones of the snout (ethmoid, vomer, lateral ethmoid, dentary, maxillae, premaxillae, ecto and mesopterygoids) and the frontal and circunorbitals are elongated. The dorsal margin is slightly concave and the anterior part is elongated. In specimens less than 80 mm, all the bones are smoother, with more regular edges. With the age increase, they become more robust with more irregular edges. A comparison of the skull between B. caballeroi and Astyanax mexicanus resulted in 25 bones with differences, while with Astyanax fasciatus, main contrasts were the supraoccipital length, the shape of the opercles and the infraorbital 3. In addition there are important differences in the dentition, gill rackers, as well as suspensory pharingeals and pharyngeal plates with respect to Astyanax.El género Bramocharax se distribuye del centro-norte de Centro América a México. Hasta este momento se conoce a Bramocharax bransfordi de Nicaragua y Costa Rica, a B. dorioni y B. baileyi de Guatemala y a B. caballeroi del lago de Catemaco, Veracruz, México. El trabajo tuvo por objetivo estudiar detalladamente el cráneo de Bramocharax caballeroi a partir del análisis de 37 topotipos de diferentes tallas y compararlo con otras especies relacionadas. B. caballeroi presenta 58 huesos en su cráneo, de los cuales 49 son elementos pareados. En vista lateral su perfil es ovalado, debido a los huesos que conforman el hocico (etmoides, vómer, etmoides lateral, mandíbula, maxila, premaxila, ecto y mesopterigoides), así como el frontal y los circunorbitales, son alargados. El margen dorsal es ligeramente cóncavo y la parte anterior alargada. En los ejemplares menores a 80 mm todos los huesos son más lisos y conforme los organismos tienen una talla mayor, se hacen más robustos y los bordes de cada hueso se hacen más irregulares. Al comparar el cráneo de B. caballeroi con el de Astyanax mexicanus se encontraron diferencias en 25 huesos, mientras que al hacerlo con A. fasciatus, los principales contrastes fueron la longitud del supraoccipital, la forma del opérculo y del infraorbital 3. Adicionalmente, se encontraron diferencias importantes en la dentición y en las branquiespinas así, como en las placas y suspensores faríngeos con respecto a los Astyanax

    Beyond the Colours: Discovering Hidden Diversity in the Nymphalidae of the Yucatan Peninsula in Mexico through DNA Barcoding

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    BACKGROUND: Recent studies have demonstrated the utility of DNA barcoding in the discovery of overlooked species and in the connection of immature and adult stages. In this study, we use DNA barcoding to examine diversity patterns in 121 species of Nymphalidae from the Yucatan Peninsula in Mexico. Our results suggest the presence of cryptic species in 8 of these 121 taxa. As well, the reference database derived from the analysis of adult specimens allowed the identification of nymphalid caterpillars providing new details on host plant use. METHODOLOGY/PRINCIPAL FINDINGS: We gathered DNA barcode sequences from 857 adult Nymphalidae representing 121 different species. This total includes four species (Adelpha iphiclus, Adelpha malea, Hamadryas iphtime and Taygetis laches) that were initially overlooked because of their close morphological similarity to other species. The barcode results showed that each of the 121 species possessed a diagnostic array of barcode sequences. In addition, there was evidence of cryptic taxa; seven species included two barcode clusters showing more than 2% sequence divergence while one species included three clusters. All 71 nymphalid caterpillars were identified to a species level by their sequence congruence to adult sequences. These caterpillars represented 16 species, and included Hamadryas julitta, an endemic species from the Yucatan Peninsula whose larval stages and host plant (Dalechampia schottii, also endemic to the Yucatan Peninsula) were previously unknown. CONCLUSIONS/SIGNIFICANCE: This investigation has revealed overlooked species in a well-studied museum collection of nymphalid butterflies and suggests that there is a substantial incidence of cryptic species that await full characterization. The utility of barcoding in the rapid identification of caterpillars also promises to accelerate the assembly of information on life histories, a particularly important advance for hyperdiverse tropical insect assemblages

    Vegetation Changes Ten Years after Catclaw Mimosa ( \u3cem\u3e Mimosa laxiflora \u3c/em\u3e ) Control with Tebuthiuron in a Short Grass Prairie at Northern Sonora, Mexico

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    Catclaw mimosa (Mimosa laxiflora) is a native, perennial half-size brush, which invades short grass prairie and competes with desirable species for water, nutrients and light interferes with cattle grazing and reduces range productivity. Tebuthiuron [1-(5-tert-Butyl-1,3,4-thiadiazol-2-yl)-1,3-dimethylurea; chemical formula C9H16N4OS] is a granular herbicide used to control invasive shrubby species on rangelands with sustainable forage responses (McGinty et al., 2009). Research trials conducted in the Chihuahuan and Sonoran deserts show that tebuthiuron at rates of 0.5 to 1.5 kg a.i./ha effectively controlled most shrubby species and significant increase forage in the Matorral area in Mexico and USA. Local information regarding catclaw mimosa control and forage production increases sustain after bush control in the short grass prairies does not exist. This study was conducted to evaluate vegetation changes after the application of tebuthiuron at rates of 0 and 1.5 kg a.i./ha to control high infestations of catclaw mimosa in the short grass prairies

    \u3cem\u3eAcacia cochliacantha\u3c/em\u3e Control in Buffel Grass Pastures at Alamos, Sonora, Mexico

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    Chirahui (Acacia cochliacantha) is an aggressive tall-shrub which invades buffelgrass (Cenchrus ciliaris L.) in the short jungle area of Southern Sonora, Mexico. As brush invasion takes over the pastures buffelgrass forage production declines and spiny brush species interferes with cattle grazing (Martin et al., 1995). Manual brush control practices are common in the area but are normally ineffective because plants re-sprout back and reinvade pastures. Tordon 101 herbicide (64.0 g a.i./l Picloram + 240.0 g a.i/l 2,4-D) has been widely used for brush control in northern Mexico but it is expensive and is planned to go out of the market soon. Prado herbicide (621.3 g a.i./kg. Amynopyralid + 94.5 g a.i./kg. Metsulfuron metil) is a new and economic product released from Dow Agrosciences in Mexico but no local data is available for its use. This study was conducted in summer of 2011 to evaluate the efficiency of Prado herbicide and manual control by machete to reduce chirahui populations

    Leaf Blast \u3cem\u3e Pyricularia grisea \u3c/em\u3e Effects on Buffelgrass Forage and Seed Production in Northwestern Mexico

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    Common buffelgrass Cenchrus ciliaris (T-4464) is an introduced species intensively planted in Mexico to increase productivity on rangelands. Studies have shown that the species produces 5 to 10 times more forage as compared to native species on rangelands (Martin et al., 1995). Previous studies in the Gulf of Mexico have shown that the fungus Pyricularia grisea causes a disease in buffelgrass known as leaf blight and induce serious damage to the plant affecting forage production and nutritive quality (Ocumpaugh and Rodríguez, 1998; González, 2002). Injuries begin in the inferior leafs as small dark stains that later are converted in injuries bronze color of round and elliptic form, necrotic, with dark red margins and with a chlorotic yellow halo (Rodriguez et al., 1999). A high humidity and temperature condition in the Pacific Northwest during the last years is believed to be creating ideal conditions for Pyricularia which is suspected to affect buffelgrass. Currently, no data are available in this region to confirm fungus presence and its impact on forage and seed productivity on buffelgrass pastures. The study was conducted at north central Sonora, Mexico to: a) evaluate the incidence and damage intensity of Pyricularia grisea in buffelgrass pastures and b) to determine its impact on forage and seed production

    Mammography Services Quality Assurance: Baseline Standards for Latin America and the Caribbean

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    Fil: Barr, Helen. No especifíca;Fil: Blanco, Susana Alicia Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Salud. Instituto Nacional del Cáncer; ArgentinaFil: Butler, Priscilla. No especifíca;Fil: da Paz, María Angela. No especifíca;Fil: Fleitas, Ileana. No especifíca;Fil: Craig, George. No especifíca;Fil: Jimenez, Pablo. No especifíca;Fil: Luciani, Silvana. No especifíca;Fil: Manrique, Javier. No especifíca;Fil: Mazal, Jonathan. No especifíca;Fil: Medlen, Kayiba. No especifíca;Fil: MIller, Colie. No especifíca;Fil: Mora, Patricia. No especifíca;Fil: Valdez Moreno, Martha Elena. No especifíca;Fil: Mosodeen, Murrie. No especifíca;Fil: Mysler, Gustavo. No especifíca;Fil: Nuche-Berenguer, Bernardo. No especifíca;Fil: Pastel, Mary. No especifíca;Fil: Pinochet, Miguel. No especifíca;Fil: Sisney, Gale. No especifíca;Fil: Ruiz Trejo, Cesar. No especifíca;Fil: Saraiya, Mona. No especifíca;Fil: Solis, Esteban. No especifíca;Fil: Swann, Phillip. No especifíca

    Monitoring an Alien Invasion: DNA Barcoding and the Identification of Lionfish and Their Prey on Coral Reefs of the Mexican Caribbean

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    BACKGROUND: In the Mexican Caribbean, the exotic lionfish Pterois volitans has become a species of great concern because of their predatory habits and rapid expansion onto the Mesoamerican coral reef, the second largest continuous reef system in the world. This is the first report of DNA identification of stomach contents of lionfish using the barcode of life reference database (BOLD). METHODOLOGY/PRINCIPAL FINDINGS: We confirm with barcoding that only Pterois volitans is apparently present in the Mexican Caribbean. We analyzed the stomach contents of 157 specimens of P. volitans from various locations in the region. Based on DNA matches in the Barcode of Life Database (BOLD) and GenBank, we identified fishes from five orders, 14 families, 22 genera and 34 species in the stomach contents. The families with the most species represented were Gobiidae and Apogonidae. Some prey taxa are commercially important species. Seven species were new records for the Mexican Caribbean: Apogon mosavi, Coryphopterus venezuelae, C. thrix, C. tortugae, Lythrypnus minimus, Starksia langi and S. ocellata. DNA matches, as well as the presence of intact lionfish in the stomach contents, indicate some degree of cannibalism, a behavior confirmed in this species by the first time. We obtained 45 distinct crustacean prey sequences, from which only 20 taxa could be identified from the BOLD and GenBank databases. The matches were primarily to Decapoda but only a single taxon could be identified to the species level, Euphausia americana. CONCLUSIONS/SIGNIFICANCE: This technique proved to be an efficient and useful method, especially since prey species could be identified from partially-digested remains. The primary limitation is the lack of comprehensive coverage of potential prey species in the region in the BOLD and GenBank databases, especially among invertebrates

    Compartiendo saberes de educaciĂłn y humanidades

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    Los capítulos referentes a este libro tratan diversos temas tales como: 1) la construcción de los estudiantes de la licenciatura en químico farmacéutico biólogo el juicio valorativo y personaI deI significado en su desarroIIo profesionaI desde eI punto de vista axiológico, 2) se realiza un estudio en el Plantel Cuauhtémoc con Ia finaIidad de orientar a Ia comunidad estudiantiI aI tratamiento deI probIema de los residuos sólidos desde su etapa de diagnóstico hasta una propuesta de solución de la problemática, 3) se analiza como a nivel básico se construye el conocimiento y la participación del género en los estudiantes, en donde se observa que el papel del docente es un promotor importante, 4) es un tema que actualmente está causando mucho interés tanto en la educación como el la población en general, las redes sociales que actuaImente ese consideran un medio de comunicación con mucha influencia dentro de la sociedad, 5) se adentra al campo de la psicología y la tanatología ante los recursos resilientes que presentan las familias ante la muerte de un hijo, 6) es una investigación dedicada a identificar Ias diferentes percepciones que tienen las mujeres y los hombres en relación a la felicidad y la desdicha dentro del matrimonio, 7) es un análisis Transgeneracional para aportar las referencias familiares que permiten la permanencia del abuso sexual infantil en tres generaciones, de las cuales en la última generación se rompe ese secreto avallazador al romper el silencio, 8) es un ensayo acerca del juego terapéutico desde el punto de vista psicoanalítico, en el que se advierte ese juego en el que entra el paciente con el psicoanalista, 9) la metodología de la observación para la integración de la pericial en psicología, en donde se denotan desde la parte jurídica como se fundamente esta pericial y fortalece el logro del dictamen para tener un buen dictamen, 10) es una propuesta de construcción y validez del instrumento BP-22 Bienestar Psicológico en el ámbito de la educación superior, 11) se identifica a Ios procesos eIectoraIes como complicados, de tal manera que abre un panorama al marketing de los partidos políticos para conducir la voluntad ciudadana, y además ayuda al posicionamiento de los partidos, 12) aporta una base sobre Ios procesos identificatorios en eI movimiento estudiantiI de Ia UNAM deI año de I999, pIanteándoIo desde dos ejes de análisis: las identidades universitarias y el apartado del texto, que permiten configurar eI movimiento estudiantiI como un acontecimiento capaz de generar articulaciones nuevas de solidaridad. AI finaI deI Iibro se encuentran Ias síntesis curricuIares de cada uno de los autores, que aportaron sus investigaciones para la integración y generación de nuevos aportes científicos.Como su nombre lo indica COMPARTIENDO SABERES DE EDUCACIÓN Y HUMANIDADES, es un Iibro que denota eI deseo de integrar conocimiento para la comunidad estudiantil, llevarlos al interés de la investigación a través de la participación de los investigadores de diferentes áreas como: la educación, las ciencias sociales y las humanidades. Que les permite tener no solo un espacio en la difusión de los avances de sus estudios, sino que además permite el generar el interés de quién lo lee en diferentes formas de investigación, se encuentran estudios tanto cualitativos como cuantitativos, desde descriptivos hasta un nivel de intervención en la práctica de estas áreas.Universidad Autónoma del Estado de méxic
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