39 research outputs found
Bird faunas of the humid montane forests of Mesoamerica: biogeographic patterns and priorities for conservation
The distribution of 335 species of birds in 33 islands of humid montane forest in
Mesoamerica is summarized, and patterns of distribution, diversity and endemism are
analysed. The montane forests of Costa Rica and western Panama far exceed other habitat
islands considered for species-richness, richness of species endemic to Mesoamerica,
and richness of species ecologically restricted to humid montane forests. Other regions,
such as the Sierra Madre del Sur of Guerrero and Oaxaca, the Los Tuxtlas region of
southern Veracruz and the mountains of Chiapas and Guatemala, also hold rich and
endemic avifaunas. Based on patterns of similarity of avifaunas, the region can be divided
into seven regions holding distinctive avifaunas (Costa Rica and western Panama;
northern Central America and northern Chiapas; southern Chiapas; eastern Mexico north
of the Isthmus of Tehuantepec; Sierra Madre del Sur; interior Oaxaca; and Transvolcanic
Belt and Sierra Madre Occidental), which serve as useful guides for the setting of
priorities for conservation action.
Se resumen las distribuciones de 335 especies de aves en 33 islas de bosque humedo de
montana en Mesoamerica, y se analizan patrones de distribution, diversidad y
endemismo. Los bosques montanos de Costa Rica y del oeste de Panama tienen la mas
alta riqueza de especies, riqueza de especies endemicas a Mesoamerica, y riqueza de
especies ecologicamente restringidas a bosque humedo de montana. Otras regiones, tales
como la Sierra Madre del Sur de Guerrero y Oaxaca, la region de Los Tuxtlas y las
montanas de Chiapas y Guatemala, tambien tienen avifaunas ricas en especies y en
endemicas. Basado en patrones de similitud de avifaunas, se puede dividir Mesoamerica
en siete regiones que tienen avifaunas distintas (Costa Rica y el oeste de Panama; el
norte de Centroamerica y el norte de Chiapas; el sur de Chiapas; el este de Mexico; la
Sierra Madre del Sur; el interior de Oaxaca; y el Eje Neovolcanico y la Sierra Madre
Occidental), las cuales pueden servir como guias en el establecimiento de prioridades
para la conservation
Evaluation of chromosome organization and microtubule arrangement in goat (capra aegragrus) oocytes after vitrification, in vitro maturation and fertilization, and early embryo development
Objective: Evaluate the use of Ethylene Glycol (EG), Dimethyl Sulfoxide (DMSO), Sucrose and Fetal Bovine Serum (FBS) as cryoprotectants and their effect on the organization of chromosomes and the arrangement of microtubules, during the vitrification process in goat oocytes matured in vitro and in the development of preimplantation embryos produced in vitro.
Design/methodology/approach: In vitro matured oocytes were divided into 3 groups (control group, cryoprotectant exposed group, vitrified group). A mixture of 15% EG, 15% DMSO, 0.4 M sucrose and 20% FBS was used for the vitrification using the Cryotop device. In vitro matured oocytes were warmed and afterwards each group was divided into two more groups. Both groups were subjected to immunofluorescence, the first group to observe the damage produced to the chromosomes and microtubules and the second group to observe the effect on the in vitro embryo development.
Results: The combined use of 15% EG, 15% DMSO, 0.4 M Sucrose and 20% FBS during vitrification did not prevent cryoinjuries in goat oocytes and in vitro produced embryos, since embryo development was disrupted before the blastocyst stage by stopping cleavage at the morula stage. This disruption was associated with chromosome decondensation and the absence of a microtubule network, thereby hindering chromosomal segregation.
Limitations on study/implications: The effect of conventional cryoprotectants on chromosomes and microtubules arrangement on vitrified goat oocytes and in vitro embryo production.
Findings/conclusions: The combined use of 15% EG, 15% DMSO, 0.4 M sucrose and 20% FBS as vitrification cryoprotectants did not prevent cryoinjuries in caprine oocytes and did not improve caprine embryo development in vitro
The role of historical and contemporary processes on phylogeographic structure and genetic diversity in the Northern Cardinal, Cardinalis cardinalis
Background
Earth history events such as climate change are believed to have played a major role in shaping patterns of genetic structure and diversity in species. However, there is a lag between the time of historical events and the collection of present-day samples that are used to infer contemporary population structure. During this lag phase contemporary processes such as dispersal or non-random mating can erase or reinforce population differences generated by historical events. In this study we evaluate the role of both historical and contemporary processes on the phylogeography of a widespread North American songbird, the Northern Cardinal, Cardinalis cardinalis. Results
Phylogenetic analysis revealed deep mtDNA structure with six lineages across the species\u27 range. Ecological niche models supported the same geographic breaks revealed by the mtDNA. A paleoecological niche model for the Last Glacial Maximum indicated that cardinals underwent a dramatic range reduction in eastern North America, whereas their ranges were more stable in MĂ©xico. In eastern North America cardinals expanded out of glacial refugia, but we found no signature of decreased genetic diversity in areas colonized after the Last Glacial Maximum. Present-day demographic data suggested that population growth across the expansion cline is positively correlated with latitude. We propose that there was no loss of genetic diversity in areas colonized after the Last Glacial Maximum because recent high-levels of gene flow across the region have homogenized genetic diversity in eastern North America. Conclusion
We show that both deep historical events as well as demographic processes that occurred following these events are critical in shaping genetic pattern and diversity in C. cardinalis. The general implication of our results is that patterns of genetic diversity are best understood when information on species history, ecology, and demography are considered simultaneously
The role of historical and contemporary processes on phylogeographic structure and genetic diversity in the Northern Cardinal, Cardinalis cardinalis
<p>Abstract</p> <p>Background</p> <p>Earth history events such as climate change are believed to have played a major role in shaping patterns of genetic structure and diversity in species. However, there is a lag between the time of historical events and the collection of present-day samples that are used to infer contemporary population structure. During this lag phase contemporary processes such as dispersal or non-random mating can erase or reinforce population differences generated by historical events. In this study we evaluate the role of both historical and contemporary processes on the phylogeography of a widespread North American songbird, the Northern Cardinal, <it>Cardinalis cardinalis</it>.</p> <p>Results</p> <p>Phylogenetic analysis revealed deep mtDNA structure with six lineages across the species' range. Ecological niche models supported the same geographic breaks revealed by the mtDNA. A paleoecological niche model for the Last Glacial Maximum indicated that cardinals underwent a dramatic range reduction in eastern North America, whereas their ranges were more stable in MĂ©xico. In eastern North America cardinals expanded out of glacial refugia, but we found no signature of decreased genetic diversity in areas colonized after the Last Glacial Maximum. Present-day demographic data suggested that population growth across the expansion cline is positively correlated with latitude. We propose that there was no loss of genetic diversity in areas colonized after the Last Glacial Maximum because recent high-levels of gene flow across the region have homogenized genetic diversity in eastern North America.</p> <p>Conclusion</p> <p>We show that both deep historical events as well as demographic processes that occurred following these events are critical in shaping genetic pattern and diversity in <it>C. cardinalis</it>. The general implication of our results is that patterns of genetic diversity are best understood when information on species history, ecology, and demography are considered simultaneously.</p
The Evolution of a Female Genital Trait Widely Distributed in the Lepidoptera: Comparative Evidence for an Effect of Sexual Coevolution
Sexual coevolution is considered responsible for the evolution of many male genital traits, but its effect on female genital morphology is poorly understood. In many lepidopterans, females become temporarily unreceptive after mating and the length of this refractory period is inversely related to the amount of spermatophore remaining in their genital tracts. Sperm competition can select for males that delay female remating by transferring spermatophores with thick spermatophore envelopes that take more time to be broken. These envelopes could select for signa, sclerotized sharp structures located within the female genital tract, that are used for breaking spermatophores. Thus, this hypothesis predicts that thick spermatophore envelopes and signa evolve in polyandrous species, and that these adaptations are lost when monandry evolves subsequently. Here we test the expected associations between female mating pattern and presence/absence of signa, and review the scant information available on the thickness of spermatophore envelopes.We made a literature review and found information on female mating pattern (monandry/polyandry), presence/absence of signa and phylogenetic position for 37 taxa. We built a phylogenetic supertree for these taxa, mapped both traits on it, and tested for the predicted association by using Pagel's test for correlated evolution. We found that, as predicted by our hypothesis, monandry evolved eight times and in five of them signa were lost; preliminary evidence suggests that at least in two of the three exceptions males imposed monandry on females by means of specially thick spermatophore envelopes. Previously published data on six genera of Papilionidae is in agreement with the predicted associations between mating pattern and the characteristics of spermatophore envelopes and signa.Our results support the hypothesis that signa are a product of sexually antagonistic coevolution with spermatophore envelopes
Trends and outcome of neoadjuvant treatment for rectal cancer: A retrospective analysis and critical assessment of a 10-year prospective national registry on behalf of the Spanish Rectal Cancer Project
Introduction: Preoperative treatment and adequate surgery increase local control in rectal cancer. However, modalities and indications for neoadjuvant treatment may be controversial. Aim of this study was to assess the trends of preoperative treatment and outcomes in patients with rectal cancer included in the Rectal Cancer Registry of the Spanish Associations of Surgeons.
Method: This is a STROBE-compliant retrospective analysis of a prospective database. All patients operated on with curative intention included in the Rectal Cancer Registry were included. Analyses were performed to compare the use of neoadjuvant/adjuvant treatment in three timeframes: I)2006â2009; II)2010â2013; III)2014â2017. Survival analyses were run for 3-year survival in timeframes I-II.
Results: Out of 14, 391 patients, 8871 (61.6%) received neoadjuvant treatment. Long-course chemo/radiotherapy was the most used approach (79.9%), followed by short-course radiotherapy ± chemotherapy (7.6%). The use of neoadjuvant treatment for cancer of the upper third (15-11 cm) increased over time (31.5%vs 34.5%vs 38.6%, p = 0.0018). The complete regression rate slightly increased over time (15.6% vs 16% vs 18.5%; p = 0.0093); the proportion of patients with involved circumferential resection margins (CRM) went down from 8.2% to 7.3%and 5.5% (p = 0.0004). Neoadjuvant treatment significantly decreased positive CRM in lower third tumors (OR 0.71, 0.59â0.87, Cochrane-Mantel-Haenszel P = 0.0008). Most ypN0 patients also received adjuvant therapy. In MR-defined stage III patients, preoperative treatment was associated with significantly longer local-recurrence-free survival (p < 0.0001), and cancer-specific survival (p < 0.0001). The survival benefit was smaller in upper third cancers.
Conclusion: There was an increasing trend and a potential overuse of neoadjuvant treatment in cancer of the upper rectum. Most ypN0 patients received postoperative treatment. Involvement of CRM in lower third tumors was reduced after neoadjuvant treatment. Stage III and MRcN + benefited the most
SUPLEMENTO DEL XV CONGRESO INTERNACIONAL DE ACTIVIDAD FĂSICA Y DEPORTE. 17,18 y 19 DE OCTUBRE DEL 2018. ENSENADA, BAJA CALIFORNIA, MĂXICO
Compendio, en formato artĂculo, de los mejores trabajos presentados en el XV CONGRESO INTERNACIONAL DE ACTIVIDAD FĂSICA Y DEPORTE celebrado los dĂas 17,18 y 19 de octubre del 2018 en la Universidad AutĂłnoma de Baja California en la ciudad de Ensenada, Baja California, MĂ©xico:La nutriciĂłn en la actividad fĂsica y deportiva: alimentos funcionales con nanotecnologĂa, aplicaciones potenciales. GonzĂĄlez GonzĂĄlez, K.Y.; Huerta Plaza, B.A.; Amaya Parra, G. (118-130)Perfil antropomĂ©trico, fĂsico y hĂĄbitos alimentarios en escolares indĂgenas de Tijuana MĂ©xico. Avendaño Cano, D.L.; GĂłmez Miranda, L.M.; Aburto Corona, J.A. (131-142)RelaciĂłn entre el clima de aprendizaje en EducaciĂłn FĂsica y la percepciĂłn de los estudiantes en las competencias del profesorado. Baños, R; Ortiz-Camacho, M.M.; Baena-Extremera, A.; Granero-Gallegos, A.; Machado-Parra, J.P.; RenterĂa, I.; Acosta, I.; RamĂrez, L. (143-153)ValoraciĂłn de capacidades fĂsicas, composiciĂłn corporal y consumo de vitaminas en una competencia de Crossfit. Cervantes-HernĂĄndez, N.; HernĂĄndez NĂĄjera, N.; Carrasco Legleu, C.E.; Candia Lujan, R.; EnrĂquez Del Castillo, L.A. (154-164)RelaciĂłn de la actividad fĂsica, caracterĂsticas antropomĂ©tricas y VO2mĂĄx en jĂłvenes universitarios: caracterĂsticas por gĂ©nero. EnrĂquez-del Castillo, L.A.; Cervantes-HernĂĄndez, N.; Carrasco-Legleu, C.E.; Candia LujĂĄn, R. (165-174)Entrenamiento vibratorio de cuerpo completo y sus efectos sobre la composiciĂłn corporal en jĂłvenes universitarios. Flores-Chico, B.; Bañuelos-Teres, L.E.; BuendĂa Lozada, E.R.P. (175-183)ActualizaciĂłn curricular, plan 2016 de la Licenciatura en Cultura FĂsica de la BUAP. Flores-Chico, B.; Flores-Flores, A.; LĂłpez de La Rosa, LE.; Aguilar-EnrĂquez, R.I.; Caballero GĂłmez, JM; Villanueva-Huerta, JA. (184-192)EvaluaciĂłn psicolĂłgica y de la musculatura isquiosural de basquetbolistas universitarias en distintas etapas deportivas. Moranchel-Charros, R.; MartĂnez-VelĂĄzquez, E.S. (193-203)Efecto del ejercicio fĂsico sobre la fuerza, resistencia y riesgo de caĂda en mujeres adultas. Ortiz Ortiz, M; Espinoza GutiĂ©rrez, R; GĂłmez Miranda, LM.; GuzmĂĄn GutiĂ©rrez, EC.; Calleja NĂșñez, JJ. (204-212)Desigualdad vs igualdad numĂ©rica y su efecto en la tĂ©cnica de jugadores de fĂștbol infantil. Vega-Orozco, SI; Gavotto Nogales, OI; Bernal Reyes, F; Horta Gim, MA; Sarabia Sainz, HM. (213-224
Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic
This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
Proposición de un método experimental para probar la potencia para vacunas antirråbicas de virus vivo modificado producidas en cultivos celulares
Se compararon inmunolĂłgicamente cuatro cepas vacunales de origen de cultivos celulares: dos comerciales y dos experimentales, incluyĂ©ndose en la prueba una vacuna de referencia para propĂłsitos de comparaciĂłn. Se inocularon por vĂÂa intraperitoneal cuatro lotes de seis ratones de 21 dĂÂas por cada diluciĂłn de las vacunas. Se efectuaron diluciones decimales de cada una de las vacunas y se inoculĂł con diluciones de 10-1, a 10-4, dejando cuatro lotes de ratones testigos sin vacunar; se procediĂł a sangrar un ratĂłn de cada lote y los cinco restantes se desafiaron a los 8, 12, 15 y 21 dĂÂas posvacunaciĂłn. Los desafĂÂos se efectuaron por vĂÂa intramuscular con virus CVS previamente titulado y con una dosis capaz de matar al 80-100% de los testigos. Los ĂÂndices mĂĄximos de protecciĂłn observado"Âą con cada cepa vacuna! fueron: 103.2 con cepa ERA, 106.2 con ERA, alto pasaje, 104-9 con cepa V-319 y 103.6 con cepa MazatĂĄn. El tĂÂtulo mĂĄs bajo indica una mayor antigenicidad de la cepa. La cepa ERA original, MazatĂĄn y V-319 fueron mĂĄs antigĂ©nicas que la ERA, alto pasaje. La tĂ©cnica aparenta ser apropiada como prueba de constataciĂłn para vacunas antirrĂĄbicas elaboradas en cultivos celulares. Se encontraron diferencias inmunogĂ©nicas entre las cuatro cepas estudiadas. Dado el bajo nĂÂșmero de ratones sangrados en este experimento, uno de cada lote, los tĂÂtulos de anticuerpos circulantes no constituyeron una valoraciĂłn de la protecciĂłn al desafĂÂo de los animales vacunados