A sensorimotor area (NIf) is required for the production of learned vocalizations

Sensory feedback is essential for the acquisition of complex motor behaviors, including birdsong. In zebra finches, auditory feedback is relayed to the descending motor pathway primarily through the nucleus interfacialis nidopalii (NIf). NIf projects to HVC - a premotor region essential for song, which projects to RA, a motor cortex analogue brain area that drives muscle activity required for vocalizations. NIf is also essential for ‘sleep replay’, a recapitulation of song-related neural dynamics in the motor pathway during sleep. Despite being one of the major inputs to the song control pathway, there is no known role for NIf in the production of zebra finch song. To address this, we reversibly inactivated NIf using TTX or Muscimol in 13 birds. We compared songs before and during inactivation and found large effects of NIf inactivation on song structure. Vocalizations after NIf inactivation resembled subsong, highly variable utterances typical of the very early phases of song learning. Subsong is driven by LMAN, the output nucleus of an avian basal ganglia circuit that projects to RA. To verify that NIf inactivations indeed switched song control from HVC to LMAN, we inactivated LMAN in conjunction with NIf in four birds. As with LMAN inactivations after HVC lesions, this manipulation led to a complete cessation of singing. We also lesioned NIf using ibotenic acid and saw the song recover within a day, consistent with previous studies. Our results show that NIf input to HVC is acutely necessary for generating learned vocal behavior in songbirds, and that in its absence vocal production reverts to subsong driven by LMAN. Absent NIf input, the song circuit reorganizes and recovers its ability to produce pre-lesion song over the course of 1-2 days, suggesting a redundant role for NIf that can be assumed by other parts of the song circuit

Distortion of Gravitational-Wave Packets Due to their Self-Gravity

When a source emits a gravity-wave (GW) pulse over a short period of time, the leading edge of the GW signal is redshifted more than the inner boundary of the pulse. The GW pulse is distorted by the gravitational effect of the self-energy residing in between these shells. We illustrate this distortion for GW pulses from the final plunge of black hole (BH) binaries, leading to the evolution of the GW profile as a function of the radial distance from the source. The distortion depends on the total GW energy released and the duration of the emission, scaled by the total binary mass, M. The effect should be relevant in finite box simulations where the waveforms are extracted within a radius of <~ 100M. For characteristic emission parameters at the final plunge between binary BHs of arbitrary spins, this effect could distort the simulated GW templates for LIGO and LISA by a fraction of 0.001. Accounting for the wave distortion would significantly decrease the waveform extraction errors in numerical simulations.Comment: accepted for publication in Physical Review

Can Virialization Shocks be Detected Around Galaxy Clusters Through the Sunyaev-Zel'dovich Effect?

In cosmological structure formation models, massive non-linear objects in the process of formation, such as galaxy clusters, are surrounded by large-scale shocks at or around the expected virial radius. Direct observational evidence for such virial shocks is currently lacking, but we show here that their presence can be inferred from future, high resolution, high-sensitivity observations of the Sunyaev-Zel'dovich (SZ) effect in galaxy clusters. We study the detectability of virial shocks in mock SZ maps, using simple models of cluster structure (gas density and temperature distributions) and noise (background and foreground galaxy clusters projected along the line of sight, as well as the cosmic microwave background anisotropies). We find that at an angular resolution of 2'' and sensitivity of 10 micro K, expected to be reached at ~ 100 GHz frequencies in a ~ 20 hr integration with the forthcoming ALMA instrument, virial shocks associated with massive M ~ 10^15 M_Sun clusters will stand out from the noise, and can be detected at high significance. More generally, our results imply that the projected SZ surface brightness profile in future, high-resolution experiments will provide sensitive constraints on the density profile of cluster gas.Comment: 15 pages, submitted to Ap

Submillimeter CO emission from shock-heated gas in the L1157 outflow

We present the CO J=6-5, 4-3, and 3-2 spectra from the blueshifted gas of the outflow driven by the low-mass class 0 protostar in the L1157 dark cloud. Strong submillimeter CO emission lines with T_mb > 30 K have been detected at 63" (~0.13 pc) south from the protostar. It is remarkable that the blue wings in the submillimeter lines are stronger by a factor of 3-4 than that of the CO J=1-0 emission line. The CO line ratios suggest that the blueshifted lobe of this outflow consists of moderately dense gas of n(H_2) = (1-3)x10^4 cm^-3 heated to T_kin = 50-170 K.It is also suggested that the kinetic temperature of the outflowing gas increases from ~80 K near the protostar to ~170 K at the shocked region in the lobe center, toward which the largest velocity dispersion of the CO emission is observed. A remarkable correlation between the kinetic temperature and velocity dispersion of the CO emission along the lobe provides us with direct evidence that the molecular gas at the head of the jet-driven bow shock is indeed heated kinematically. The lower temperature of ~80 K measured at the other shocked region near the end of the lobe is explained if this shock is in a later evolutionary stage, in which the gas has been cooled mainly through radiation of the CO rotational lines.Comment: 10 pages, 4 PDF figures, APJL in pres

Identification of epidermal Pdx1 expression discloses different roles of Notch1 and Notch2 in murine KrasG12D-induced skin carcinogenesis in vivo

Background The Ras and Notch signaling pathways are frequently activated during development to control many diverse cellular processes and are often dysregulated during tumorigenesis. To study the role of Notch and oncogenic Kras signaling in a progenitor cell population, Pdx1-Cre mice were utilized to generate conditional oncogenic KrasG12D mice with ablation of Notch1 and/or Notch2. Methodology/Principal Findings Surprisingly, mice with activated KrasG12D and Notch1 but not Notch2 ablation developed skin papillomas progressing to squamous cell carcinoma providing evidence for Pdx1 expression in the skin. Immunostaining and lineage tracing experiments indicate that PDX1 is present predominantly in the suprabasal layers of the epidermis and rarely in the basal layer. Further analysis of keratinocytes in vitro revealed differentiation-dependent expression of PDX1 in terminally differentiated keratinocytes. PDX1 expression was also increased during wound healing. Further analysis revealed that loss of Notch1 but not Notch2 is critical for skin tumor development. Reasons for this include distinct Notch expression with Notch1 in all layers and Notch2 in the suprabasal layer as well as distinctive p21 and β-catenin signaling inhibition capabilities. Conclusions/Significance Our results provide strong evidence for epidermal expression of Pdx1 as of yet not identified function. In addition, this finding may be relevant for research using Pdx1-Cre transgenic strains. Additionally, our study confirms distinctive expression and functions of Notch1 and Notch2 in the skin supporting the importance of careful dissection of the contribution of individual Notch receptors

Push-out tests on embedded shear connections for hybrid girders with trapezoidal web

[EN] Hybrid girders with corrugated web are increasingly used in bridge engineering due to its numerous favorable properties. For the web-to-slab connection different layouts have been developed in the past, however, just a few design proposals can be found in the international literature for the determination of the connection’s resistance, especially for the embedded types. In case of these connections the corrugated web is simply embedded into the concrete slab strengthened by transverse rebars through concrete dowels or horizontal headed studs welded to the web. The aim of the current research program is to investigate the structural behavior and the shear capacity of embedded connections by full scale push-out tests. In the current paper the results of 5 push-out tests are introduced having different embedded connection types investigating (i) the effect of the embedding depth, (ii) the existence of the concrete dowels (through cut-outs in the steel web) with transverse rebars and (iii) the influence of the steel flange. These parameters may have significant influence on the behavior and capacity of embedded type connections, which are studied in the research program. During the tests the applied load and the slip between the steel web and concrete slabs are measured in order to study the initial stiffness, the ductility and the shear capacity of the connections.The presented research program is part of the “BridgeBeam” R&D project No. GINOP-2.1.1-15-2015-00659; the financial support is gratefully acknowledged. Through the first, second and fourth authors the paper was also supported by the ÚNKP-17-3-IV., ÚNKP-17-2- I. and ÚNKP-17-4 New National Excellence Program of the Ministry of Human Capacities, respectively; the financial supports are gratefully acknowledged.Jáger, B.; Németh, G.; Kovács, N.; Kövesdi, B.; Kachichian, M. (2018). Push-out tests on embedded shear connections for hybrid girders with trapezoidal web. En Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures. ASCCS 2018. Editorial Universitat Politècnica de València. 581-586. https://doi.org/10.4995/ASCCS2018.2018.7158OCS58158

The extent and cost of corruption in transport infrastructure. New evidence from Europe

Transport infrastructure provision from roads to waterways involves large amounts of public funds in very complex projects. It is hardly a surprise that all across Europe, but especially in high corruption risk countries, it is a primary target of corrupt elites. This article provides a state-of-the-art review of the literature on the cost of corruption and estimates the level of corruption risks and associated costs in European infrastructure development and maintenance in 2009-2014 using novel data on over 40,000 government contracts. Two forms of corruption costs are investigated in the empirical section: 1) distorting spending structure and project design, and 2) inflating prices. Findings indicate that corruption steers infrastructure spending towards high value as opposed to small value investment projects. It also inflates prices by 30-35% on average with largest excesses in high corruption risk regions. Contrary to perceptions, corruption risks in infrastructure are decoupled to a considerable extent from the national corruption environment. Source data and risk scores are made downloadable at digiwhist.eu/resources/data

Comparación del test directo de anticuerpos fluorescentes y el cultivo bacteriológico para detección de Brucella suis

Methods available for detection of Brucella sp from different specimens include bacteriological culture or detection of specific DNA fragments by polymerase chain reaction. The use of fluorescein-labeled anti-Brucella globulin for demonstrating this antigen in animal tissues is a simple, easy, reproducible, cheap and fast technique. The aim of this work was to evaluate the gamma globulin fraction of polyclonal anti-Brucella abortus serum labeled with fluorescein iso-tio-cyanate (FITC-labeled antibody): 1) against different smooth and rough Brucella sp, 2) against bacterium of other genus, and 3) to compare direct fluorescent antibody test results with bacteriological culture for the detection of B. suis in different tissues from infected animals. This conjugate stained all Brucella sp with different intensities but it did not stain any heterologous bacterium tested. Background fluorescence associated with its use on smears from infected sources of different specimens was particularly low. Most of the infected tissues showed the presence of yellowish-green fluorescent organisms with brucella morphology. The tested FITC-labeled antibody allows a quick, effective and inexpensive diagnosis of brucellosis.El diagnóstico de brucelosis se apoya en el cultivo bacteriológico o en la detección de fragmentos de ADN de la bacteria mediante la reacción en cadena de la polimerasa. El empleo de una inmunoglobulina anti-Brucella conjugada a fluoresceína para la detección de este antígeno en tejidos constituye una técnica simple, fácil, reproducible, económica y rápida. El objetivo de este trabajo fue evaluar la fracción gammaglobulínica de un suero policlonal anti-Brucella abortus marcada con isotiocianato de fluoresceína (FITC), 1) contra distintas especies lisas y rugosas de Brucella sp, 2) contra bacterias de otros géneros, y 3) comparar los resultados obtenidos con la inmunofluorescencia directa y el cultivo bacteriológico para la detección de B. suis en distintos tejidos de porcinos infectados. Este conjugado detectó todas las brucelas con distinta intensidad de fluorescencia, pero no hubo fluorescencia inespecífica cuando se ensayaron las bacterias de otros géneros. La fluorescencia de fondo en muestras de los distintos tejidos infectados fue baja. La mayoría de los tejidos infectados mostraron la presencia de microorganismos verde-fluorescentes con la morfología de las brucelas. El anticuerpo conjugado a FITC permitió un diagnóstico de brucelosis rápido, efectivo y económico