The Brown-York mass of black holes in Warped Anti-de Sitter space

We give a direct computation of the mass of black holes in Warped Anti-de Sitter space (WAdS) in terms of the Brown-York stress-tensor at the boundary. This permits to explore to what extent the holographic renormalization techniques can be applied to such type of deformation of AdS. We show that, despite some components of the boundary stress-tensor diverge and resist to be regularized by the introduction of local counterterms, the precise combination that gives the quasilocal energy density yields a finite integral. The result turns out to be in agreement with previous computations of the black hole mass obtained with different approaches. This is seen to happen both in the case of Topologically Massive Gravity and of the so-called New Massive Gravity. Here, we focus our attention on the latter. We observe that, despite other conserved charges diverge in the near boundary limit, the finite part in the large radius expansion captures the physically relevant contribution. We compute the black hole angular momentum in this way and we obtain a result that is in perfect agreement with previous calculations.Comment: 8 pages. v2 discussion and appendix added, references added. To appear in JHE

"Productivity and innovation spillovers: Micro evidence from Spain"

This article analyses the impact that innovation expenditure and intrasectoral and intersectoral externalities have on productivity in Spanish firms. While there is an extensive literature analysing the relationship between innovation and productivity, in this particular area there are far fewer studies that examine the importance of sectoral externalities, especially with the focus on Spain. One novelty of the study, which covers the industrial and service sectors, is that we also consider jointly the technology level of the sector in which the firm operates and the firm size. The database used is the Technological Innovation Panel (PITEC), which includes 12,813 firms for the year 2008 and has been little used in this type of study. The estimation method used is Iteratively Reweighted Least Squares method (IRLS), which is very useful for obtaining robust estimations in the presence of outliers. The results confirm that innovation has a positive effect on productivity, especially in high-tech and large firms. The impact of externalities is more heterogeneous because, while intrasectoral externalities have a positive and significant effect, especially in low-tech firms independently of size, intersectoral externalities have a more ambiguous effect, being clearly significant for advanced industries in which size has a positive effect..Productivity, innovation, sectoral externalities, firm size. JEL classification:D24, O33

Public Participation, Teacher Accountability, and School Outcomes:Findings from Baseline Surveys in Three Indian States

This paper presents findings from baseline surveys on student learning achievement, teacher effort and community participation in three Indian states, Karnataka, Madhya Pradesh and Uttar Pradesh. Results indicate low teacher attendance and poor student learning. Parents and school committees are neither aware of their oversight roles nor participating in school management. However, there is substantial heterogeneity in outcomes across states. Karnataka has better student and teacher outcomes as well as higher levels of community awareness and participation than the other two states. We find substantial variation in teacher effort within schools, but most observable teacher characteristics are not associated with teacher effort. One reason for low teacher effort may be lack of accountability. Regression analysis suggests low rates of teacher attendance are only part of the problem of low student achievement. The gains in test scores associated with higher rates of attendance and engagement in teaching are small in the states of Madhya Pradesh and Uttar Pradesh, suggesting teachers themselves may not be effective. Ineffective teaching may result from lack of accountability as well as poor professional development of teachers. Further research is needed to examine not only issues of accountability but also professional development of teachers.Academic Achievement; annual grants; average class size; basic competencies; basic education; basic services; blackboards; call; civil service; civil service teachers; class size; class sizes

Mode Selection Rules for Two-Delay Systems: Dynamical Explanation for the Function of the Register Hole on the Clarinet

Generally, time-delay systems are regarded as multi-attractor systems. We investigate mode selection rules for two-delay systems considering which oscillation mode is first excited by the Hopf bifurcation with increasing a bifurcation parameter. In particular, we focus on the case that the strength of the short time delay α1 is lower than that of the long time delay α2. In a certain range of α1/α2 in which it is sufficiently small but still not negligible, the third-harmonic mode occupies a particular range of the ratio of the two delay times such that 2 < tR2/tR1 < 4, where tR1 and tR2 denote the short and long delay times, respectively. This is the key for understanding the function of the register hole on the clarinet, which is smaller in radius than the other tone holes, but works well to raise the pitch of first register notes in a wide range more than an octave by a twelfth (19 semitones), i.e., generating third harmonics, when opened. This is confirmed using a simple model of the clarinet with two delays: short and long time delays are regarded as delayed reflections caused by the register hole and the open end of the pipe, respectively. The working range of the register hole roughly corresponds to the particular range of the third-harmonic mode for two-delay systems (2 < tR2/tR1 < 4)

Anisotropic scale invariant spacetimes and black holes in Zwei-Dreibein Gravity

We show that Zwei-Dreibein Gravity (ZDG), a bigravity theory recently proposed by Bergshoeff, de Haan, Hohm, Merbis, and Townsend in ref. [1], admits exact solutions with anisotropic scale invariance. These type of geometries are the three-dimensional analogues of the spacetimes which were proposed as gravity duals for condensed matter systems. In particular, we find Schrödinger invariant spaces as well as Lifshitz spaces with arbitrary dynamical exponent z. We also find black holes that are asymptotically Lifshitz with z = 3, showing that these (non-constant curvature) solutions of New Massive Gravity (NMG) are persistent after the introduction of the infinite tower of higher-curvature terms of ZDG, provided a renormalization of the parameters. Black holes in asymptotically warped Anti-de Sitter spaces are also found. Interestingly, in almost all the geometries studied in this work, the metric associated with the second dreibein turns out to be equivalent, up to a constant global factor, to the first one. This phenomenon has been previously observed in other bigravity theories in asymptotically flat and asymptotically Anti-de Sitter backgrounds. However, for the particular case of the z = 3 Lifshitz black hole, here we found that the second metric corresponds to a different black hole that coincides with the former only in the asymptotic region. In fact, we find a new family of z = 3 black holes that corresponds to a one-parameter deformation of the NMG solution.Fil: Goya, Andrés Fabio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin

An exploratory study of co-authorships among Iranian scientists in experimental sciences

This paper investigates the factors that made international co-authorship between scientists in Iran and elsewhere possible. A questionnaire was sent out to Iranian scientists in fields of physics, chemistry, and biology who had co-authored an internationally published journal article during 2003. The main foreign co-author in each of the articles was identified and questions regarding this co-author and the collaborative event were asked. The results show that not all co-authored articles were the results of collaborative projects. Also, the main collaborative motives behind the co-authorships were identified and described. Among these, we could mention sharing laboratory devices, accessing knowledge, and increase the efficiency of the study at hand. It is clear that emigrated Iranian scientists play an important role as collaborators and probably also as links to the international scientific community as a whole. Cultural factors mix with scientific and work related one

PENGARUH NILAI TUKAR, INFLASI, MODAL DAN TENAGA KERJA TERHADAP PERTUMBUHAN EKONOMI DI INDONESIA

Penelitian ini bertujuan untuk menganalisis pengaruh nilai tukar, inflasi, modal dan tenaga kerja terhadap pertumbuhan ekonomi di Indonesia selama kurun waktu tahun 1990 sampai dengan tahun 2015. Data pada penelitian ini adalah data sekunder yang bersumber dari Badan Pusat Statistik dan Bank Indonesia yang meliputi data nilai tukar rupiah terhadap dolar, inflasi, pembentukan modal tetap domestik bruto, dan jumlah tenaga kerja. Analisis pada penelitian ini berdasarkan kepada Fungsi Produksi Cobb-Douglas dengan menggunakan metode ordinary least square (OLS) secara rekursif. Hasil penelitian menunjukkan bahwa modal berpengaruh positif terhadap pertumbuhan ekonomi. Secara metode rekursif, inflasi dan nilai tukar berpengaruh signifikan terhadap pertumbuhan ekonomi. Khususnya Inflasi berpengaruh signifikan negatif terhadap pertumbuhan ekonomi melalui suku bunga dan modal. Namun, jumlah tenaga kerja tidak berpengaruh signifikan terhadap pertumbuhan ekonomi. Artinya pemerintah perlu untuk menurunkan angka inflasi untuk dapat menurunkan angka suku bunga sehingga meningkatkan jumlah modal dan pada akhirnya meningkatkan pertumbuhan ekonomi di Indonesia.Kata Kunci: Nilai tukar. Inflasi. Modal. Tenaga kerja. Pertumbuhan Ekonomi. Fungsi Produksi Cobb-Douglas. Ordinary least square. Rekursi

Outbreak of a neurotoxic side-gilled sea slug (Pleurobranchaea sp.) in Argentinian coasts

Since 2009 we have been registering the outbreak of an unknown side-gilled sea slug of the genus Pleurobranchaea in coastal waters of Argentina, southwestern Atlantic Ocean. Examination of both external macroscopic features and internal structures via electron microscopy did not allow us to conclusively identify the species. Nevertheless, since Argentinian specimens closely resemble Pleurobranchaea maculata (a species native from Australia and New Zealand known to contain a potent neurotoxin) we performed a bioassay in our specimens, which was positive for neurotoxins. The presence of this pleurobranch in Argentinian waters is of concern beyond the ecological effects of the outbreak of a marine predator and requires urgent attention. This work provides a guide to distinguish between this unidentified species and the sympatric cryptogenic Pleurobranchaea inconspicua, based on features that are readily observable in fresh and preserved specimens. We discuss the potential effects of this outbreak on local communities.Fil: Farias, Nahuel Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología. Laboratorio de Invertebrados; ArgentinaFil: Obenat, Sandra Mabel. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología. Laboratorio de Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Goya, Alejandra Beatriz. Ministerio de Agricultura, Ganaderia, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria. Laboratorio Regional Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin