The Parallelometer: a mechanical device to study curvature

A simple mechanical device is introduced, the parallelometer, that can be used to measure curvatures of surfaces. The device can be used as a practical illustration of parallel transport of a vector and to study Berry phase shift when it is carried along a loop on the surface. Its connection to the Foucault pendulum is discussed. The experimental results can be successfully compared with the theoretical expectations. The experiment is inexpensive and conceptually easy to perform and understand for a beginner

How portable is level-0 behavior? A test of level-k theory in game with non-neutral frames

We test the portability of level-0 assumptions in level-k theory in an experimental investigation of behavior in Coordination, Discoordination, and Hide and Seek games with common, non-neutral frames. Assuming that level-0 behavior depends only on the frame, we derive hypotheses that are independent of prior assumptions abou tsalience. Those hypotheses are not confirmed. Our findings contrast with previous research which has fitted parameterized level-k models to Hide and Seek data. We show that, as a criterion of successful explanation, the existence of a plausible model that replicates the main patterns in these data has a high probability of false positives

A Full Characterization of Best-Response Functions in the Lottery Colonel Blotto Game

We fully characterize best-response functions in Colonel Blotto games with lottery contest success functions

Heritage, tourism and development in rural territories of drylands : a case study in the Bermejo Valley region (La Rioja, Argentina)

Fil: Julio Rojo, David. Universidad Nacional de La RiojaFil: Torres, Laura. Instituto Argentino de Investigaciones de las Zonas Áridas Fil: Pastor, Gabriela. Instituto Argentino de Investigaciones de las Zonas Áridas <IADIZA

Choice Flexibility and Long-Run Cooperation

Understanding how incentives and institutions help scaling up cooperation is important, especially when strategic uncertainty is considerable. Evidence suggests that this is challenging even when full cooperation is theoretically sustainable thanks to indefinite repetition. In a controlled social dilemma experiment, we show that adding partial cooperation choices to the usual binary choice environment can raise cooperation and efficiency. Under suitable incentives, partial cooperation choices enable individuals to cheaply signal their desire to cooperate, reducing strategic uncertainty. The insight is that richer choice sets can form the basis of a language meaningful for coordinating on cooperation

Uso de la amilasa termoestable de Bacillus licheniformis en la digestibilidad in vitro del almidón de sorgo y maíz

Varias enzimas celulolíticas se han usado para incrementar la digestion ruminal de la fibra y mejorar la producción en rumiantes. Sin embargo, se ha dado poca atención a las enzimas amilolíticas como un tratamiento a los granos, a pesar de que la productividad del ganado puede mejorar con el uso de mezclas de enzimas externas, incluyendo amilasas y celulasas. Así, se incubó sorgo, sorgo rolado con vapor y maíz (500 mg de grano), con fluido ruminal para estudiar el efecto de la adición de alfa-amilasa de Bacillus licheniformis (400 mL) en la digestibilidad in vitro del almidón a las 12 h de fermentación. La incubación (bloque) fue repetida tres veces y los resultados se analizaron bajo un diseño de Bloques Completos al Azar Generalizado, utilizando la interacción bloque por tratamiento para estimar el error experimental. No se detectó interacción entre tipo de grano y enzima. La adición de la enzima termoestable incrementó (p<0.0001) la digestión in vitro del almidón (59.9 vs. 38.5%). La digestión in vitro promedio del almidón (p<0.0001) fue más baja en el sorgo (30.42%), intermedia en el sorgo rolado con vapor (50.72%), y más alta en el maíz (66.48%). La adición de la amilasa termoestable de Bacillus licheniformis incrementó la digestión in vitro del almidón del sorgo y maíz; por lo tanto, esta enzima podría mejorar la digestión in vivo del almidón y la eficiencia alimenticia de dietas basadas en granos con tasas bajas e intermedias de fermentación

Canine Trypanosoma cruzi infection in the Bolivian Chaco

A cross-sectional study on Trypanosoma cruzi was carried out in 2013 to evaluate the role of dogs as possible source of infection for humans in two rural communities of the highly endemic Bolivian Chaco (Bartolo, Chuquisaca Department, n = 57 dogs; and Ivamirapinta, Santa Cruz Department, n = 48 dogs). Giemsa-stained thick and thin smears, rapid immunochromatographic test (ICT) (Chagas Quick test, Cypress Diagnostic, Belgium) and polymerase chain reaction for T. cruzi on dried blood spots were performed. All smears proved negative by microscopic examination, whereas 23/103 (22%) were positive by ICT and 5/105 (5%) blood samples contained T. cruzi DNA, evidencing the potential role of dogs in the domestic transmission of the parasite