What Causes Partial F1 Hybrid Viability? Incomplete Penetrance versus Genetic Variation

Hernán López-Fernández is with Texas A&M University, Daniel I. Bolnick is with UT Austin.Background -- Interspecific hybrid crosses often produce offspring with reduced but non-zero survivorship. In this paper we ask why such partial inviability occurs. This partial inviability could arise from incomplete penetrance of lethal Dobzhansky-Muller incompatibilities (DMIs) shared by all members of a hybrid cross. Alternatively, siblings may differ with respect to the presence or number of DMIs, leading to genotype-dependent variation in viability and hence non-Mendelian segregation of parental alleles in surviving F1 hybrids. Methodology/Principal Findings -- We used amplified fragment length polymorphisms (AFLPs) to test for segregation distortion in one hybrid cross between green and longear sunfish (Lepomis cyanellus and L. megalotis). Hybrids showed partial viability, and twice as much segregation distortion (36.8%) of AFLPs as an intraspecific control cross (18.8%). Incomplete penetrance of DMIs, which should cause genotype-independent mortality, is insufficient to explain the observed segregation distortion. Conclusions/Significance -- We conclude that F1 hybrid sunfish are polymorphic for DMIs, either due to sex-linked DMI loci (causing Haldane's Rule), or polymorphic autosomal DMI loci. Because few AFLP markers were sex-linked (2%), the most parsimonious conclusion is that parents may have been heterozygous for loci causing hybrid inviability.The University of Texas at Austin funded DIB as assistant professor, HLF as a postdoctoral researcher at DIB's lab, and all experimental work. The National Science Foundation grant DEB 0516831 supported HLF as a postdoctoral researcher at Texas A&M University during the writing phase of this project.Biological Sciences, School o

Effect of an Er,Cr:YSGG Laser on the Debonding of Lithium Disilicate Veneers With Four Different Thicknesses

Introduction: The objective of this study was to compare in vitro the resistance and type of failure in the debonding of lithium disilicate veneers with four different thicknesses using an erbium chromium yttrium-scandium gallium-garnet (Er, Cr: YSGG) laser.Methods: Sixty-eight bovine teeth were used to bond round lithium disilicate veneers with a 6-millimeter diameter and four different thicknesses: group 1 (0.4 mm), group 2 (0.8 mm), group 3 (1.2 mm), and group 4 (1.6 mm). Each sample was irradiated with an Er, Cr: YSGG laser with 4 W of power and a frequency of 50 Hz, during 60 seconds, scanning concentrically. The energy density per pulse or fluency applied was 5.33 J/cm2 for the four groups. The samples were subjected to a force in a universal testing machine and then observed under a microscope to determine the type of failure. Data were statistically analyzed with the non-parametric Kruskal-Wallis test.Results: The tendency in the results revealed that the thicker veneers showed more resistance to the debonding process. The debonding strength for group 3 was the highest (5.62 MPa), followed by group 4 (5.20 MPa), then group 2 (0.85 MPa), and finally group 1 (0.0 MPa). The most frequent type of failure was a cohesive failure in cement (CC) for all groups, with 73.53% (P ≤ 0.083).Conclusion: Er, Cr: YSGG laser irradiation influences the debonding of lithium disilicate veneers with different thicknesses: the smaller thickness showed the greater debonding. The thickness of veneers was not associated with the type of failure

Diet-Morphology Correlations in the Radiation of South American Geophagine Cichlids (Perciformes: Cichlidae: Cichlinae)

Genera within the South American cichlid tribe Geophagini display specialized feeding and reproductive strategies, with some taxa specialized for both substrate-sifting and mouth brooding. Several lineages within the clade also possess an epibranchial lobe (EBL), a unique pharyngeal structure that has been proposed to have a function in feeding and/or mouth brooding. A recently published genus-level phylogeny of Neotropical cichlids was used as the evolutionary framework for investigating the evolution of morphological features presumably correlated with diet and mouth brooding in the tribe Geophagini. We tested for possible associations between the geophagine epibranchial lobe and benthic feeding and mouth brooding. We also addressed whether the EBL may be associated with unique patterns of diversification in certain geophagine clades. Tests of binary character correlations revealed the EBL was significantly associated with mouth brooding. We also tested for a relationship between diet and morphology. We analyzed stomach contents and morphometric variation among 21 species, with data for two additional species obtained from the literature. Principal Components Analysis revealed axes of morphological variation significantly correlated with piscivory and benthivory, and both morphology and diet were significantly associated with phylogeny. These results suggest that the EBL could be an adaptation for either feeding or mouth brooding. The EBL, however, was not associated with species richness or accelerated rates of phyletic diversification

Non-cooperative target identification based on singular value decomposition

Non-Cooperative Target Identification based on High Resolution Range Profiles is a key research domain in the Defense industry. In this paper a method based on the application of Singular Value Decomposition to a matrix of range profiles is defined. The decomposition is applied to reduce dimensionality and to accomplish recognition in the transformed domain. So as to confirm the feasibility of the methodology, identification experiments of profiles coming from electromagnetic simulations are conducted, revealing promising results

Fish biogeography in the â Lost Worldâ of the Guiana Shield: Phylogeography of the weakly electric knifefish Gymnotus carapo (Teleostei: Gymnotidae)

AimThe Guiana Shield region exhibits extraordinary topography that includes sheer, flatâ topped mountains (tepuis) atop an upland platform. Rivers of the eastern Pakaraima Mountains descend to Atlantic coastal lowlands, often traversing spectacular rapids and waterfalls. For fish species distributed in both uplands and lowlands, it is unclear whether these rapids and waterfalls present population or biogeographical boundaries. We sought to test this using the geographically widespread bandedâ electric knifefish (Gymnotus carapo) as a model.LocationThe Guiana Shield region of South America.MethodsWe sampled 60 Gymnotus carapo specimens from the Guiana Shield region, and 75 G. carapo and closely related species from other parts of South America. We sequenced the mitochondrial cytochrome b gene and an intron from the nuclear S7 ribosomal protein gene, and used maximum likelihood and Bayesian treeâ building approaches to generate phylogenetic trees of haplotypes.ResultsHaplotype sharing is minimal between populations separated by elevational barriers. We found evidence for two main haplotype clades in the Guiana Shield: one distributed in Atlantic coastal regions that includes most lowland samples, and one inland that includes most upland samples. Inland Guiana samples are more closely related to samples from the Amazon basin than to those of Atlantic coastal regions. A single sample from Tafelberg tepui in Suriname was most closely related to the Atlantic coastal lineages.Main conclusionsRiverine barriers that result from steep elevational gradients in the Guiana Shield inhibit gene flow between uplands and lowlands, even for a widely distributed species. Biogeographical relationships of Guiana Shield G. carapo are complex, with most upland lineages showing affinities to the Amazon basin, rather than to nearby lowland drainages of the Atlantic coast.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142908/1/jbi13177.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142908/2/jbi13177_am.pd

Una aproximación de análisis multivariante hacia los condicionantes de la complementariedad entre actividades innovativas. Aplicación al sector de software de Argentina

La innovación exitosa en las empresas depende del desarrollo e integración de nuevos conocimientos en el proceso innovativo, tanto internos como externos a la organización. El presente trabajo surge como continuación de estudios anteriores sobre cómo estos conocimientos se complementan (o sustituyen) en el proceso de innovación de las empresas de software (Morero, 2013, Morero et al., 2014, Morero et al., 2015). En el último de los estudios de esta línea (Morero, et al., 2015), se confirma la existencia de una relación de complementariedad entre actividades innovativas internas y externas, pero los resultados se vuelven más inconclusos al momento de analizar los determinantes de dicha complementariedad. Dado esto, el presente artículo persigue contribuir a abordar este aspecto. Esto es, principalmente importa saber en qué medida estas relaciones de complementariedad se ven influidas por aspectos ambientales y por aspectos estructurales de las empresas. Para ello proponemos una estrategia de abordaje empírico comparativamente poco reconocida en la disciplina, alternativa a los enfoques fuertemente econométricos, como el enfoque directo o de correlaciones (Mohnen y Röller, 2005). La propuesta es reconocer un cuerpo de literatura empírica que sigue una combinación de técnicas estadísticas, como por ejemplo métodos de análisis multivariante, que denominamos enfoque de asociación. Este enfoque tiene un potencial superador de las muchas limitaciones que los testeos y regresiones econométricas tienen para elucidar la cuestión que nos compete.www.redpymes.org.arFil: Morero, Hernán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; Argentina.Fil: Morero, Hernán Alejandro. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: López, Juan José. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Fernández, Valentina. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Sonnenberg Palmieri, Josefina. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Organización Industria

SOCS3 deregulation contributes to aberrant activation of the JAK/STAT pathway in precursor T-cell neoplasms

Despite the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway being frequently altered in T-ALL/LBL, no specific therapy has been approved for T-ALL/LBL patients with constitutive signalling by JAK/STAT, so there is an urgent need to identify pathway members that may be potential therapeutic targets. In the present study, we searched for JAK/STAT pathway members potentially modulated through aberrant methylation and identified SOCS3 hypermethylation as a recurrent event in T-ALL/LBL. Additionally, we explored the implications of SOCS3 deregulation in T-ALL/LBL and demonstrated that SOCS3 counteracts the constitutive activation of the JAK/STAT pathway through different molecular mechanisms. Therefore, SOCS3 emerges as a potential therapeutic target in T-ALL/LBLComunidad de Madrid, Grant/Award Number: B2017/BMD-3778; LINFOMAS-CM; Fundación Científica Asociación Española Contra el Cáncer, Grant/Award Number: PROYE18054PIRI; Fundación Ramón Areces, Grant/Award Number: CIVP19S7917; Instituto de Investigación Sanitaria Fundación Jiménez Díaz; Ministerio de Ciencia, Innovación y Universidades, Grant/ Award Number: RTI2018- 093330-B-I00 and MCIU/FEDER; Ministerio de Economía y Competitividad, Grant/Award Number: SAF2015-70561-R and MINECO/FEDE

Videopíldoras de Derecho Procesal en los estudios de grado: Derecho Procesal Civil I

El proyecto de innovación núm. 105 del año 2016 se ha desarrollado en el marco de la creación y el empleo de nuevas herramientas tecnológicas de aprendizaje mediante la técnica llamada videodcasting; esto es, la transmisión digital de audio y media mediante internet. En concreto, un grupo amplio y compacto de profesores de Derecho Procesal han generado múltiples videopodcasts de corta duración que cubren todos los temas de la asignatura “Derecho Procesal Civil I”, con la finalidad de ponerlos a disposición del resto de profesores del Departamento de Derecho Procesal de la UCM que haya de impartirla