The early stages of heart development: insights from chicken embryos

The heart is the first functioning organ in the developing embryo and the detailed understanding of the molecular and cellular mechanisms involved in its formation provides insights into congenital malformations affecting its function and therefore the survival of the organism. Because many developmental mechanisms are highly conserved, it is possible to extrapolate from observations made in invertebrate and vertebrate model organisms to human. This review will highlight the contributions made through studying heart development in avian embryos, particularly the chicken. The major advantage of chick embryos is their accessibility for surgical manipulations and functional interference approaches, both gain- and loss-of-function. In addition to experiments performed in ovo, the dissection of tissues for ex vivo culture, genomic or biochemical approaches, is straightforward. Furthermore, embryos can be cultured for time-lapse imaging, which enables tracking of fluorescently labeled cells and detailed analyses of tissue morphogenesis. Owing to these features, investigations in chick embryos have led to important discoveries, often complementing genetic studies in mouse and zebrafish. As well as including some historical aspects, we cover here some of the crucial advances made in understanding of early heart development using the chicken model

Innovative monitoring methods in the context of adaptive management of hunting in the amazon, Colombia

Managing complex hunting socio-ecological systems within a context of uncertainty requires setting up efficient ways to monitor changes in the system and inform decision making in an adaptive management process. In such context, building trust through collaboration, institutional development, and social learning enhances efforts to foster ecosystem co-management. This approach draws explicit attention to the learning and collaboration functions necessary to improve our understanding of, and ability to respond to, complex social–ecological systems. Monitoring methods can generate observations over long time periods, incorporate large sample sizes, are relatively inexpensive and invite the participation of harvesters as researchers. We tested a combination of role playing games, traditional knowledge, technological innovations (camera traps and KoBoCollect) to co-develop a monitoring system for wildlife resources and hunting efforts in an indigenous hunting territory in the Amazon Colombia where hunters have organized themselves to develop an adaptive management approach to their hunting activities. The methods involve the active participation of hunters in data collection and an automatic tool for data analysis that allows users to visualize outputs instantaneously (e.g. map of offtakes per species, graph with number of prey per species per month). The information generated is directly usable by hunters for management decisions. We demonstrate the importance of such participatory monitoring models for building institutional trust between stakeholders (indigenous communities, governmental institutions in charge of wildlife management and civil society) as well as provide tools that are directly usable by local decision makers

Effective Potential and Thermodynamics for a Coupled Two-Field Bose Gas Model

We study the thermodynamics of a two-species homogeneous and dilute Bose gas that is self-interacting and quadratically coupled to each other. We make use of field theoretical functional integral techniques and evaluate the one-loop finite temperature effective potential for this system considering the resummation of the leading order temperature dependent as well as infrared contributions. The symmetry breaking pattern associated to the model is then studied by considering different values of self and inter-species couplings. We pay special attention to the eventual appearance of reentrant phases and/or shifts in the observed critical temperatures as compared to the monoatomic (one-field Bose) case.Comment: 21 pages, 4 eps figure

La educaci?n musical como estrategia pedag?gica para fortalecer actividades motoras en los ni?os de 4 a 5 a?os de edad.

92 Recurso Electr?nicoNuestro proyecto de investigaci?n llamado la educaci?n musical como estrategia pedag?gica para favorecer las actividades que estimulan la motricidad gruesa en los ni?os y ni?as de 4 a?os del centro desarrollo infantil (CDI) galan. Fue estructurado pensando en las necesidades de los ni?os y ni?as como tambi?n concienciar a los docentes sobre la importancia de crear estrategias que estimulen y fomenten el desarrollo de dimensiones motrices por medio de la m?sica, creando situaciones, momentos , espacios adecuados , los cuales los ni?os y las ni?as hayan afianzado sus habilidades motoras y falencias encontradas , trabajando actividades de coordinando, rondas interpretaci?n de cuentos y juegos de roles en nuestra practica pedag?gica. De acuerdo a lo anterior y relacion?ndolo con en el desarrollo integral del ni?o y ni?a podemos decir que las consecuencias por la falta de estimulaci?n musical y la danza en los ni?os, originan la preferencia por la m?sica y baile de los adultos, poco desarrollo auditivo, problemas de aprendizaje, falta de atenci?n y concentraci?n, problemas de tipo emocional. Y el buen desarrollo corporal, Respecto a este tema, se le atribuye a que la familia no posee un conocimiento b?sico acerca de la importancia de ofrecer a sus hijos un est?mulo a su desarrollo musical, como tampoco la comunidad y el entorno que lo rodea ayudan al ni?o en este proceso; para consolidar el concepto de familia la funci?n y su rol dentro del desarrollo del menor, citamos a Echeverri ligia, quien expone: ?la funci?n de la familia con el individuo es hist?rica y culturalmente variable porque el n?mero de elementos que la conforman varia as? como el grado de parentesco entre ellos y modela al individuo hasta que este madura o se convierte en adulto. Palabras Claves: m?sica, educaci?n, desarrollo, espacios, integral, motricidad, necesidades, estrategias, ni?os, ni?as, dimensiones, rondas, juegos, actividades, familias, emociones, falencias.Our research project called musical education as a pedagogical strategy to favor the activities that stimulate the gross motor skills in the children of 4 years of the child development center (CDI) galan. It was structured taking into account the needs of children and also to make teachers aware of the importance of creating strategies that stimulate and encourage the development of motor dimensions through music, creating situations, moments, adequate spaces, which children And the girls have strengthened their motor skills and found shortcomings, working coordinating activities, story interpretation rounds and role plays in our pedagogical practice. According to the above and relating it with the integral development of the boy and girl we can say that the consequences due to the lack of musical stimulation and dance in the children, originate the preference for the music and dance of the adults, little auditory development, Problems of learning, lack of attention and concentration, emotional problems. And the good body development. With regard to this issue, it is attributed to the family does not have a basic knowledge about the importance of offering their children a stimulus to their musical development, as neither the community and the surrounding environment help The child in this process; To consolidate the concept of family function and its role in the development of the child, we quote Echeverri Ligia, who states: "The family's role with the individual is historically and culturally variable because the number of elements that make up it varies as well The degree of kinship between them and models the individual until it matures or becomes adult. Keyworks: m?sica, educaci?n, desarrollo, espacios, integral, motricidad, necesidades, estrategias, ni?os, ni?as, dimensiones, rondas, juegos, actividades, familias, emociones, falencias

Branching processes, the max-plus algebra and network calculus

Branching processes can describe the dynamics of various queueing systems, peer-to-peer systems, delay tolerant networks, etc. In this paper we study the basic stochastic recursion of multitype branching processes, but in two non-standard contexts. First, we consider this recursion in the max-plus algebra where branching corresponds to finding the maximal offspring of the current generation. Secondly, we consider network-calculus-type deterministic bounds as introduced by Cruz, which we extend to handle branching-type processes. The paper provides both qualitative and quantitative results and introduces various applications of (max-plus) branching processes in queueing theory

Convergence in variable Lebesgue spaces

We consider the relationship in the variable Lebesgue space Lp(·)(Ω) between convergence in norm, convergence in modular, and convergence in measure, for both bounded and unbounded exponent functions

Twists and turns

Computational modelling of the heart tube during development reveals the interplay between tissue asymmetry and growth that helps our hearts take shape

Radiogalaxies in the Sloan Digital Sky Survey: spectral index-environment correlations

We analyze optical and radio properties of radiogalaxies detected in the Sloan Digital Sky Survey (SDSS). The sample of radio sources are selected from the catalogue of Kimball & Ivezi\'c (2008) with flux densities at 325, 1400 and 4850 MHz, using WENSS, NVSS and GB6 radio surveys and from flux measurements at 74 MHz taken from VLA Low-frequency Sky Survey \citep{cohen}. We study radiogalaxy spectral properties using radio colour-colour diagrams and find that our sample follows a single power law from 74 to 4850 MHz. The spectral index vs. spectroscopic redshift relation ($\alpha-z$) is not significant for our sample of radio sources. We analyze a subsample of radio sources associated with clusters of galaxies identified from the maxBCG catalogue and find that about 40% of radio sources with ultra steep spectra (USS, $\alpha<-1$, where $S_\nu \propto \nu^{\alpha}$) are associated with galaxy clusters or groups of galaxies. We construct a Hubble diagram of USS radio sources in the optical $r$ band up to $z\sim0$.8 and compare our results with those for normal galaxies selected from different optical surveys and find that USS radio sources are around as luminous as the central galaxies in the maxBCG cluster sample and typically more than 4 magnitudes brighter than normal galaxies at $z\sim0$.3. We study correlations between spectral index, richness and luminosity of clusters associated with radio sources. We find that USS at low redshift are rare, most of them reside in regions of unusually high ambient density, such of those found in rich cluster of galaxies. Our results also suggest that clusters of galaxies associated with steeper than the average spectra have higher richness counts and are populated by luminous galaxies in comparison with those environments associated to radio sources with flatter than the average spectra. A plausible explanation for our results is that radio emission is more pressure confined in higher gas density environments such as those found in rich clusters of galaxies and as a consequence radio lobes in rich galaxy clusters will expand adiabatically and lose energy via synchrotron and inverse Compton losses, resulting in a steeper radio spectra.Comment: 13 pages, 14 figures; accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journal

The IR Luminosity Functions of Rich Clusters

We present MIPS observations of the cluster A3266. About 100 spectroscopic cluster members have been detected at 24 micron. The IR luminosity function in A3266 is very similar to that in the Coma cluster down to the detection limit L_IR~10^43 ergs/s, suggesting a universal form of the bright end IR LF for local rich clusters with M~10^15 M_sun. The shape of the bright end of the A3266-Coma composite IR LF is not significantly different from that of nearby field galaxies, but the fraction of IR-bright galaxies (SFR > 0.2M_sun/yr) in both clusters increases with cluster-centric radius. The decrease of the blue galaxy fraction toward the high density cores only accounts for part of the trend; the fraction of red galaxies with moderate SFRs (0.2 < SFR < 1 M_sun/yr) also decreases with increasing galaxy density. These results suggest that for the IR bright galaxies, nearby rich clusters are distinguished from the field by a lower star-forming galaxy fraction, but not by a change in L*_IR. The composite IR LF of Coma and A3266 shows strong evolution when compared with the composite IR LF of two z~0.8 clusters, MS 1054 and RX J0152, with L*_IR \propto (1+z)^{3.2+/-0.7},Phi*_IR \propto (1+z)^{1.7+/-1.0}. This L*_IR evolution is indistinguishable from that in the field, and the Phi*_IR evolution is stronger, but still consistent with that in the field. The similarity of the evolution of bright-end IR LF in very different cluster and field environments suggests either this evolution is driven by the mechanism that works in both environments, or clusters continually replenish their star-forming galaxies from the field, yielding an evolution in the IR LF that is similar to the field. The mass-normalized integrated star formation rates (SFRs) of clusters within 0.5R_200 also evolve strongly with redshift, as (1+z)^5.3.Comment: 15 pages, 8 figures, 1 table, accepted by Ap