Mentoring the Mentors: Implementation and Evaluation of Four Fogarty-Sponsored Mentoring Training Workshops in Low-and Middle-Income Countries.

A growing body of evidence highlights the importance of competent mentoring in academic research. We describe the development, implementation, and evaluation of four regional 2-day intensive workshops to train mid- and senior-level investigators conducting public health, clinical, and basic science research across multiple academic institutions in low- and middle-income countries (LMICs) on tools and techniques of effective mentoring. Sponsored by the Fogarty International Center, workshops included didactic presentations, interactive discussions, and small-group problem-based learning and were conducted in Lima, Peru; Mombasa, Kenya; Bangalore, India; and Johannesburg, South Africa, from 2013 to 2016. Mid- or senior-level faculty from multiple academic institutions within each region applied and were selected. Thirty faculty from 12 South America-based institutions, 29 faculty from eight East Africa-based institutions, 37 faculty from 14 South Asia-based institutions, and 36 faculty from 13 Africa-based institutions participated, with diverse representation across disciplines, gender, and academic rank. Discussions and evaluations revealed important comparisons and contrasts in the practice of mentoring, and specific barriers and facilitators to mentoring within each cultural and regional context. Specific regional issues related to hierarchy, the post-colonial legacy, and diversity arose as challenges to mentoring in different parts of the world. Common barriers included a lack of a culture of mentoring, time constraints, lack of formal training, and a lack of recognition for mentoring. These workshops provided valuable training, were among the first of their kind, were well-attended, rated highly, and provided concepts and a structure for the development and strengthening of formal mentoring programs across LMIC institutions

Tennis play intensity distribution and relation with aerobic fitness in competitive players

15 p.Los objetivos de este estudio fueron (1) describir la intensidad relativa del juego de tenis simulado en función del tiempo acumulado en tres zonas de intensidad metabólica y (2) determinar las relaciones entre esta distribución de intensidad de juego y la aptitud aeróbica de un grupo de jugadores competitivos. 20 jugadores masculinos de nivel avanzado a élite (ITN) realizaron una prueba de tenis de resistencia específica en el campo incremental hasta el agotamiento para determinar el consumo máximo de oxígeno (VO2max) y los umbrales de ventilación primero y segundo (VT1, VT2). Los parámetros de ventilación y de intercambio de gases se monitorizaron utilizando un analizador de gas portátil telemétrico (K4 b2, Cosmed, Roma, Italia). Dos semanas después, los participantes jugaron un juego de tenis simulado contra un oponente de nivel similar. Las zonas de intensidad (1: baja, 2: moderada y 3: alta) fueron delimitadas por los valores individuales de VO2 correspondientes a VT1 y VT2, y se expresaron como porcentaje del VO2 máximo y la frecuencia cardíaca. Cuando se expresó en relación con el VO 2 máx. El porcentaje de tiempo de juego en la zona 1 (77 ± 25%) fue significativamente mayor (p <0,001) que en la zona 2 (20 ± 21%) y la zona 3 (3 ± 5%). Se encontraron correlaciones positivas de moderadas a altas entre VT1, VT2 y VO2max, y el porcentaje del tiempo de juego transcurrido en la zona 1 (r = 0,68-0,75), así como las correlaciones inversas de bajas a altas entre las variables metabólicas y el porcentaje de tiempo empleado en las zonas 2 y 3 (r = -0.49–0.75). Los jugadores con mejor aptitud aeróbica juegan a intensidades relativamente más bajas. Concluimos que los jugadores pasaron más del 75% del tiempo en su zona de baja intensidad, con menos del 25% del tiempo dedicado a intensidades moderadas a altas. La aptitud aeróbica parece determinar la intensidad metabólica que los jugadores pueden mantener durante todo el juegoS

Model Independent Higgs Boson Mass Limits at LEP

We derive model-independent constraints on Higgs mass and couplings from associated signals for higher masses, accessible at LEP2. This work is motivated by the fact that, in many extensions of the standard model, the Higgs boson can have substantial "invisible" decay modes, for example, into light or massless weakly interacting Goldstone bosons associated to the spontaneous violation of lepton number below the weak scale.Comment: FTUV/93-19, 13 pag + 2 figures(not included but available upon request), Late

The stellar content of the young open cluster Trumpler 37

With an apparent cluster diameter of 1.5{\deg} and an age of ~4 Myr, Trumpler 37 is an ideal target for photometric monitoring of young stars as well as for the search of planetary transits, eclipsing binaries and other sources of variability. The YETI consortium has monitored Trumpler 37 throughout 2010 and 2011 to obtain a comprehensive view of variable phenomena in this region. In this first paper we present the cluster properties and membership determination as derived from an extensive investigation of the literature. We also compared the coordinate list to some YETI images. For 1872 stars we found literature data. Among them 774 have high probability of being member and 125 a medium probability. Based on infrared data we re-calculate a cluster extinction of 0.9-1.2 mag. We can confirm the age and distance to be 3-5 Myr and ~870 pc. Stellar masses are determined from theoretical models and the mass function is fitted with a power-law index of alpha=1.90 (0.1-0.4 M_sun) and alpha=1.12 (1-10 M_sun).Comment: 9 pages, 10 figures, 2 long tables, accepte

Efficient Behavior of Small-World Networks

We introduce the concept of efficiency of a network, measuring how efficiently it exchanges information. By using this simple measure small-world networks are seen as systems that are both globally and locally efficient. This allows to give a clear physical meaning to the concept of small-world, and also to perform a precise quantitative a nalysis of both weighted and unweighted networks. We study neural networks and man-made communication and transportation systems and we show that the underlying general principle of their construction is in fact a small-world principle of high efficiency.Comment: 1 figure, 2 tables. Revised version. Accepted for publication in Phys. Rev. Let

Transit Timing Analysis in the HAT-P-32 System

We present the results of 45 transit observations obtained for the transiting exoplanet HATP- 32b. The transits have been observed using several telescopes mainly throughout the YETI (Young Exoplanet Transit Initiative) network. In 25 cases, complete transit light curves with a timing precision better than 1.4 min have been obtained. These light curves have been used to refine the system properties, namely inclination i, planet-to-star radius ratio Rp/Rs, and the ratio between the semimajor axis and the stellar radius a/Rs. First analyses by Hartman et al. suggests the existence of a second planet in the system, thus we tried to find an additional body using the transit timing variation (TTV) technique. Taking also the literature data points into account, we can explain all mid-transit times by refining the linear ephemeris by 21 ms. Thus, we can exclude TTV amplitudes of more than ∼1.5min

Transit Timing Analysis in the HAT-P-32 system

We present the results of 45 transit observations obtained for the transiting exoplanet HAT-P-32b. The transits have been observed using several telescopes mainly throughout the YETI network. In 25 cases, complete transit light curves with a timing precision better than $1.4\:$min have been obtained. These light curves have been used to refine the system properties, namely inclination $i$, planet-to-star radius ratio $R_\textrm{p}/R_\textrm{s}$, and the ratio between the semimajor axis and the stellar radius $a/R_\textrm{s}$. First analyses by Hartman et al. (2011) suggest the existence of a second planet in the system, thus we tried to find an additional body using the transit timing variation (TTV) technique. Taking also literature data points into account, we can explain all mid-transit times by refining the linear ephemeris by 21ms. Thus we can exclude TTV amplitudes of more than $\sim1.5$min.Comment: MNRAS accepted; 13 pages, 10 figure

Dealing with the Inventory Risk. A solution to the market making problem

Market makers continuously set bid and ask quotes for the stocks they have under consideration. Hence they face a complex optimization problem in which their return, based on the bid-ask spread they quote and the frequency at which they indeed provide liquidity, is challenged by the price risk they bear due to their inventory. In this paper, we consider a stochastic control problem similar to the one introduced by Ho and Stoll and formalized mathematically by Avellaneda and Stoikov. The market is modeled using a reference price $S_t$ following a Brownian motion with standard deviation $\sigma$, arrival rates of buy or sell liquidity-consuming orders depend on the distance to the reference price $S_t$ and a market maker maximizes the expected utility of its P&L over a finite time horizon. We show that the Hamilton-Jacobi-Bellman equations associated to the stochastic optimal control problem can be transformed into a system of linear ordinary differential equations and we solve the market making problem under inventory constraints. We also shed light on the asymptotic behavior of the optimal quotes and propose closed-form approximations based on a spectral characterization of the optimal quotes