Does beak size affect acoustic frequencies in woodcreepers?

We assessed the effect of beak morphology on the acoustic structure of woodcreeper (subfamily Dendrocolaptinae) songs using a comparative analysis of independent contrasts. For the song of each species, we measured the maximum and minimum frequencies, the bandwidth, and the emphasized frequency. Residuals of variationin beak length and acoustic frequencies after controlling for body size and phylogeny were calculated for each species and compared. We found a negative relationship between the residuals of acoustic frequencies and the residuals of beak length. This relationship was significant for emphasized frequency when we excluded two open-habitat species, Scimitar-billed Woodcreeper (Drymornis bridgesii) and Narrow-billed Woodcreeper (Lepidocolaptes angustirostris).This result is consistent with the hypothesis that the suprasyringeal vocal tract has resonating properties that affect the frequency spectrum of the song.Fil: Palacios, María Gabriela. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Tubaro, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentin

Edición de genes mediante crispr-cas9: más que Cortar y pegar

En esta revisión se exponen las características y aplicaciones de CRISPR-Cas9, un sistema inmune adaptativo propio de algunas especies de bacterias y arqueas que lo utilizan para defenderse de bacteriófagos. Fue descubierto por el doctor español Francisco Mojica cuando se encontraba investigando sobre un tipo de arquea en las salinas de Santa Pola (Alicante). El mecanismo inmune de estos sistemas consta de tres fases donde un ARN guía forma un complejo proteico con una proteína nucleasa llamada Cas9 para así poder escindir el ADN del organismo exógeno y evitar su infección. Debido a la simpleza de su mecanismo, CRISPR-Cas9 lleva siendo utilizado por diversos grupos de investigadores desde 2013 con el objetivo de convertirse en una nueva herramienta de terapia génica que permita modificar el genoma de personas que sufran enfermedades con componente genético. El propósito es introducir los componentes en un vector, viral o no viral, que sea capaz de alcanzar la célula diana y cortar selectivamente una secuencia del ADN que posteriormente será reparada por los métodos de recombinación HDR Y NHEJ. Los sistemas CRISPR-Cas9 presentan numerosas ventajas frente a otros tipos de terapia génica como ZFN o TALEN como son su bajo coste y su fácil diseño. Sin embargo, la reparación del gen anómalo y los cambios no deseados en el genoma son aspectos que los investigadores deberán de solventar para conseguir una herramienta biológica segura y eficaz. Por último, se recoge información sobre los últimos avances hasta la fecha y sobre los ensayos preclínicos basados en este sistema, profundizando en las enfermedades hereditarias retinianas debido a las características particulares del ojo que lo convierten en un órgano ideal para ser tratado con sistemas CRISPR-Cas9.Universidad de Sevilla. Doble Grado en Farmacia y Óptica y Optometrí

First principles study of Bi dopen CdTe thin film solar cells: electronic and optical properties

Nowadays, efficiency improvement of solar cells is one of the most important issues in photovoltaic systems and CdTe is one of the most promising thin film photovoltaic materials we can found. CdTe reported efficiencies in solar energy conversion have been as good as that found in polycrystalline Si thin film cell [1], besides CdTe can be easily produced at industrial scale

Enhancement of optical absorption in Ga-chalcopirite-based intermediate-band materials for high efficiency solar cells

We present absorption properties enhancement for two CuGaS2-based intermediate-band materials, as promising compounds for high efficiency, lower-cost photovoltaic devices. Previous band diagrams calculations predicted that these materials present a partially filled localized band within the band gap of the host semiconductor, which would increase the absorption of low-energy photons, creating additional electron–hole pairs respect to a conventional semiconductor. This could ideally result in an increase of the photocurrent of the cell without the fall of the open-circuit voltage. In this paper we show, using density functional methods, the effect of this intermediate band on the optical properties of the derived alloys. We highlight the significant enhancement of the absorption coefficient observed in the most intense range of the solar emission and we study the reflectance and transmittance properties of the materials in order to understand the effect of the thickness of the sample on the optical properties. We compare two different substituents of the Ga atoms in CuGaS2, namely, Ti and Cr atoms, able to form the intermediate-band material, and their interest for photovoltaic applications

First language acquisition corpora in English and their influence on other languages

Traballo Fin de Grao en Lingua e Literatura Inglesas. Curso 2015-2016This Traballo de Fin de Grao was initially conceived as an exploration on how corpora of language acquisition in English influenced (or not) corpora in other languages, namely in Spanish. The paper can be seen as having two differentiated parts. The first one provides the background for the topics that we wan to address, which can be grouped in two disciplines of the linguistic studies: Corpus Linguistics and Psycholinguistics (more specifically, first language acquisition). The second part presents an analysis of language acquisition corpora in English. The corpora are firstanalyzed and then confronted with one in Spanish. Chapter 3 functions as a pivot for the two parts. It brings together Corpus Linguistics and first language acquisition in Brian MacWhinney and Catherine Snow’s CHILDES projec

Simulation of the formation of clusters of bioconjugated FeO nanoparticles after their specific interaction with a biomarker

Trabajo Fin de Máster en Física de la Materia Condensada y de los Sistemas Biológicos (especialización en biofísica)In this work, we have built a computational model to perform a comprehensive study of the formation of clusters of nanoparticles functionalized with a ligand which interacts specifically with a biomarker. In our model the interaction between the nanoparticles and the biomarkers is always mediated by the ligands and the only interaction between the nanoparticles is a Lennard-Jonnes force that prevents them from overlapping. The influence of the concentration of nanoparticles and biomarkers and the number of ligands per nanoparticle in the mean size, compactness, and dispersion of sizes of the clusters has been studied using several combinations of parameters. The results have been compared with experimental measures to check the validity of our model and we have found out in which ranges of parameters our model is valid and in which ranges there are non-negligible interactions that we are not considerin

La dignidad humana en la jurisprudencia constitucional colombiana: un estudio sobre su evolución conceptual

Artículo de investigaciónEl presente estudio hace una reflexión sobre los fundamentos teóricos y filosóficos en los que se ha apoyado la jurisprudencia constitucional Colombiana para atribuirle valor al concepto de Dignidad Humana, dentro de una línea jurisprudencial propuesta. Así mismo, se determinará el grado en que el concepto ha sido modificado a lo largo de la historia de la Honorable Corte, basado en las sentencias hito.PregradoAbogad

Photonic Pulse Shaping Techniques for Arbitrary Waveform Generation

The motivation of this thesis is to explore the generation of arbitrary microwave waveforms through photonic means, showing the advantages they may offer. Some techniques will be presented for this purpose, as well as their applications. Firstly, the technique known as Direct Space To Time Mapping (DST) will be presen-+ted, which as the name properly says, turns the spatial profile into the time profile of the beam. Then, we will present the main technique of the thesis, which shows a great analogywith the DST. This technique is known as Frequency to Time Mapping (FTM) orDirect Fourier Transformation (DFT). In order to derive the expressions needed for the understanding of the DFT, dispersion theory in media will be explained starting from the macroscopic Maxwell equations derived in the appendix. It will be seen how combining spectrum shaping techniques along with the DFT we are able to generate an arbitrary radio-frequency waveform. After being mathematically derived, simulations will be performed to put numbers and further prove of the theory. The achievable time bandwidth product (TBWP) will also be derived and later compared to the one obtained by Matlab simulation. Furthermore, the DFT will then be applied for time reversal by photonic means. A microwave signal up to 10 nanoseconds long can be time-reversed using fibers, as it will be proved in theory and simulation. Applications related to these microwave generation techniques will also be explored, showing the research interest of this cutting-edge discipline

Methods for steady state thermal-hydraulic analysis of pressurized water reactor cores

A one-pass simplified analysis method for steady state PWR core has been developed. The advantages over the other multistage approaches have been discussed and compared- Recommended nodal patterns for modelling the reactor core have been proposed. Also the effect due to the lumped channel technique utilized in both the simplified method and existing multistage methods has been investigated for both D and 3D problems. For the nodal pattern recommended with the proposed one-pass analysis method, use of the lumped channel technique introduces negligible errors.New England Electric System, Northeast Utilities Service Co. under the MIT Energy Laboratory Electric Power Progra