Early specification of sensory neuron fate revealed by expression and function of neurogenins in the chick embryo

The generation of sensory and autonomic neurons from the neural crest requires the functions of two classes of basic helix-loop-helix (bHLH) transcription factors, the Neurogenins (NGNs) and MASH-1, respectively (Fode, C., Gradwohl, G., Morin, X., Dierich, A., LeMeur, M., Goridis, C. and Guillemot, F. (1998) Neuron 20, 483-494; Guillemot, F., Lo, L.-C., Johnson, J. E., Auerbach, A., Anderson, D. J. and Joyner, A. L. (1993) Cell 75, 463-476; Ma, Q., Chen, Z. F., Barrantes, I. B., de la Pompa, J. L. and Anderson, D. J. (1998 Neuron 20, 469-482). We have cloned two chick NGNs and found that they are expressed in a subset of neural crest cells early in their migration. Ectopic expression of the NGNs in vivo biases migrating neural crest cells to localize in the sensory ganglia, and induces the expression of sensory neuron-appropriate markers in non-sensory crest derivatives. Surprisingly, the NGNs can also induce the expression of multiple pan-neuronal and sensory-specific markers in the dermomyotome, a mesodermal derivative. Taken together, these data suggest that a subset of neural crest cells may already be specified for a sensory neuron fate early in migration, as a consequence of NGN expression

Matrix Product States, Random Matrix Theory and the Principle of Maximum Entropy

Using random matrix techniques and the theory of Matrix Product States we show that reduced density matrices of quantum spin chains have generically maximum entropy.Comment: 11 pages, 4 figure

Production values as program quality signals in Spanish linear TV: A comparison of two periods

Technology disruption, digitalization and media convergence have triggered a profound crisis in the television industry. In this context, quality is an essential strategic element for success, especially when consumers have learned through their experience with VOD, becoming more demanding and less loyal customers. Then, has the importance of quality signals changed with the emergence of new online alternatives? And the quality perception among viewers? Our research explores four production values (the host, content, the set, and technical quality) as TV program quality signals and their effect on the quality perception of entertainment programs of Spanish broadcasters. We compare two years: 2012 and 2016, a period during which the Spanish television market changed due to appearance of OTT services. Using t-tests and regression models, we establish that the importance of quality signals varied over this period, with content proving more important and the set less so in 2016 as compared with 2012. Additionally, in 2016, the results show that the quality perception of linear TV entertainment programs depended more on subjective elements such as liking and satisfaction than on objective elements, as it was in 2012. Finally, our findings are discussed, and some managerial implications and future research are suggested

Development and Survivorship of Immature Angoumois Grain Moth (Lepidoptera: Gelechiidae) on Stored Corn

Life history of immature Angoumois grain moths, Sitotroga cerealella (Olivier), was studied on dent corn (Pioneer 3320) at 10, 15, 20, 25, 30, 35, and 40°C and at 43, 53-61, 75-76, and 82-87% RH under laboratory conditions. At 10 and 40°C, none of the stages survived at any relative humidity. Temperature was the main factor affecting egg incubation period, larval-pupal development time, and egg and larval-pupal survivorship. The shortest egg development times occurred at temperatures of 30°C and higher, but they increased sharply as temperature decreased. Larval-pupal development time was shortest at 30°C. Survivorship was optimal at 20-30°C for eggs and larvae-pupae, but larval-pupal survivorship decreased sharply at 15 and 35°C. Duration of larval-pupal development did not vary with sex. Newly emerged females were twofold heavier than males, and temperature and relative humidity did not affect weight. Sex ratio of emerging adults did not differ from 1:1 at any temperature or relative humidity. The optimum conditions for development of Angoumois grain moth on corn were 30°C and 75% RH. The data will be useful for determining safe storage conditions for corn and for developing a computer model for simulating population dynamics of immature S. cerealella

Responsible I(m)ovation in Asia Pacific regions

Over the past 20 years, a debate has developed on the differences between innovation and imitation strategies as mechanisms by which businesses operating in the Asia Pacific region may gain a competitive advantage. The current research contributes to this debate from a different perspective by exploring some of the challenges and opportunities associated with the combination of both strategies into what has been defined as imovation. Imovators and imovations do not stand alone in business ecosystems. Rather, they should be embraced in the context of sustainability-related virtues and emerging capabilities, such as ethical behaviour, co-responsibility and positive social impact. Taking dynamic capabilities as a theoretical lens, this paper conducts an empirical investigation of responsible imovation in a sample of 180 enterprises operating in the Asia Pacific market. In particular, this research evaluates the relationship between dynamic capabilities and imovation capabilities using a logistic regression analysis whereby we correlate the three main features of imovation strategies: strategic alliances, strategic decision-making and product innovations. To the best of our knowledge, ours is the first study to focus on responsible imovation in the Asia Pacific market from an empirical perspective. The research highlights the key organisational and individual actions with the potential both to preserve existing capabilities and to create and integrate new ones. Our findings highlight the importance of technology adoption for responsible imovation to become more effective and accessible to imovators in the Asia Pacific business ecosystem. We conclude that responsible imovations combined with product-level innovations and core dynamic capabilities pave the way towards more rapid growth and a more sustainable competitive advantage.publishedVersio

Nuclear spirals as feeding channels to the Supermassive Black Hole: the case of the galaxy NGC 6951

We report the discovery of gas streaming motions along nuclear spiral arms towards the LINER nucleus of the galaxy NGC 6951. The observations, obtained using the GMOS integral field spectrograph on the Gemini North telescope, yielded maps of the flux distributions and gas kinematics in the Halpha, [NII]6584 and [SII]6717,31 emission lines of the inner 7x5 arcsec^2 of the galaxy. This region includes a circumnuclear star-forming ring with radius 500pc, a nuclear spiral inside the ring and the LINER nucleus. The kinematics of the ionized gas is dominated by rotation, but subtraction of a kinematic model of a rotating exponential disk reveals deviations from circular rotation within the nuclear ring which can be attributed to (1) streaming motions along the nuclear spiral arms and (2) a bipolar outflow which seems to be associated to a nuclear jet. On the basis of the observed streaming velocities and geometry of the spiral arms we estimate a mass inflow rate of ionized gas of 3x10^(-4) Msun/yr, which is of the order of the accretion rate necessary to power the LINER nucleus of NGC 6951. Similar streaming motions towards the nucleus of another galaxy with LINER nucleus -- NGC 1097 -- have been reported by our group in a previous paper. Taken together, these results support a scenario in which nuclear spirals are channels through which matter is transferred from galactic scales to the nuclear region to feed the supermassive black hole.Comment: 25 pages, 6 eps figures, accepted for publication in Ap

Caso edificio Space

The Space building was a residential complex located in the city of Medellín (Colombia), which was divided into six stages or towers. In the last stage of the project, tower six suffered a structural failure that caused its collapse, which led to the demolition of the other towers. The main issues discussed are related to the design of structures, columns, beams, and loads that a structure can withstand given the terrain and the materials used for construction. In addition, the study carried out by the Universidad de Los Andes, which was the main source of information in the investigation of the collapse and its aftermath, will be presented. This article will collect and show information on this case in the areas directly related to civil engineering and what happened to those involved in the project.El edificio Space fue un conjunto residencial ubicado en la ciudad de Medellín (Colombia), el cual se dividía en seis etapas o torres. En la última etapa del proyecto, la torres seis, sufrió una falla estructural que produjo el colapso de esta, y esto llevó a la demolición de las demás torres. Los problemas principales que se trataron están relacionados con el diseño de estructuras, columnas, vigas y cargas que puede soportar una estructura dadas las situaciones del terreno y los materiales utilizados para la construcción. Además, se dará a conocer el estudio realizado por la Universidad de Los Andes la cual fue la principal fuente de información en la investigación del colapso y posteriormente a este. El presente artículo recolectará y mostrará información de este caso en los ámbitos ligados directamente a la ingeniería civil y lo ocurrido con los implicados en el proyecto

Relationship between stream velocity & depth and snail size distribution & density of the balcones elimia, elimia comalensis (pilsbry, 1890) (gastropoda: pleuroceridae) in comal springs, texas

Pleurocerid snails are important components of aquatic ecosystems and the majority of species are threatened or endangered. This study describes aspects of the life-history of Elimia comalensis, specifically population density in relationship to water velocity and depth, and seasonal change. Also examined are spatial segregation of different E. comalensis age groups and the relationship of snail size (proxy for age) to flow, depth, and seasonal change. The study was carried out in the lotic portion of spring run 3, Comal Springs, New Braunfels, Texas, by quadrat sampling at 10 m intervals from the spring head to Landa Lake in Fall, Winter, and Spring 2005-2006. The length of snails was strongly influenced by physical characteristics of the stream with stream depth, water velocity, and distance from the spring head accounting for -43% of the individual variability for shell length (

CHANGES IN SHELL MORPHOLOGY OF ELIMIA COMALENSIS (GASTROPODA: PLEUROCERIDAE) FROM THE EDWARDS PLATEAU, TEXAS

Species in the pleurocerid genus Elimia are important components of freshwater systems in the eastern United States, but little is known about their natural history. Using dual-simultaneous linear regression and principal components analyses, we show patterns of morphological change in two populations of E. comalensis from the Edwards Plateau, Texas. Both populations had similar rates of change for all shell measurements analyzed, and both showed similar decreases in growth as total length of shell increased. However, the size at which growth slowed was different between populations, and small shells tended to have a consistent shape, while larger shells were more variable. - Aunque las especies del ge´nero Elimia son componentes importantes de los sistemas de agua dulce del este de los Estados Unidos, se sabe poco de su historia natural. Usando dos ana´lisis, uno de regresio´n linear dual simulta´nea y otro de componentes principales, mostramos patrones de cambio morfolo´gico en dos poblaciones de E. comalensis del Edwards Plateau, Texas. Las dos tuvieron tazas de cambios similares para todas las medidas de conchas analizadas y las dos tuvieron disminuciones similares en el crecimiento mientras la longitud total de concha aumentaba. Sin embargo, el taman˜o al que el crecimiento disminuyo´ fue diferente entre las poblaciones y las conchas pequen˜as tendieron a tener una forma consistente y las conchas ma´s grandes fueron ma´s variables

Detection of Stored-Grain Insect Infestation in Wheat Transported in Railroad Hopper-Cars

Levels of insect infestation, insect spatial distribution, and the relationship between the number of insect-damaged kernels (IDK) and the number of insects present in grain samples in three-hopper railcars transporting wheat from country elevators to a mill were studied. Six of eight sampled railcars were infested with more than two species of insects. The most abundant species collected were the lesser grain borer, Rhyzopertha dominica (F.), and rusty grain beetle, Cryptolestes ferrugineus (Stephens), with the larval stage of the two species being the most prevalent (\u3e90%). The spatial distributions of these two species within the grain mass were typically clumped in railcar compartments containing\u3e0.4 insect/2.75-kg sample of wheat, and these foci of high-infestation levels varied in compartments within the railcars and among the sampled railcars. There were no significant correlations between IDK and insect density for any of the different stage-specific insect populations that were collected in the grain samples. Mean numbers of immatures and IDK differed among railcars and compartments within railcars, but not among grain depths. Number of insects in the first discharge sample was not correlated with mean numbers of insects in the entire compartment. This indicates that each compartment of a railcar should be sampled to determine level of insect infestation but that sampling at different depths within a compartment is less important