Search

Much of our basic understanding of cognitive and social processes in infancy relies on measures of looking time, and specifically on infants’ visual preference for a novel or familiar stimulus. However, despite being the foundation of many behavioral tasks in infant research, the determinants of infants’ visual preferences are poorly understood, and differences in the expression of preferences can be difficult to interpret. In this large-scale study, we test predictions from the Hunter and Ames model of infants' visual preferences. We investigate the effects of three factors predicted by this model to determine infants’ preference for novel versus familiar stimuli: age, stimulus familiarity, and stimulus complexity. Drawing from a large and diverse sample of infant participants (N = XX), this study will provide crucial empirical evidence for a robust and generalizable model of infant visual preferences, leading to a more solid theoretical foundation for understanding the mechanisms that underlie infants’ responses in common behavioral paradigms. Moreover, our findings will guide future studies that rely on infants' visual preferences to measure cognitive and social processes.

Este artículo contrasta los alcances de las políticas energéticas nacionales de algunos Estados América Latina, respecto a los objetivos de las políticas ambientales globales (Sustainable Developments Goals- SDG), esto considerando que la incompatibilidad entre las políticas energéticas y las políticas ambientales marcará la historia contemporánea de los llamados «países en vía de desarrollo». A nivel teórico conceptual esta comparación usa el enfoque de la gobernanza multilateral, específicamente a través del concepto de «innovación» se plantea que la innovación en gobernanza, constituye una clave para encontrar alternativas locales frente a la mencionada incompatibilidad. Desde la perspectiva de Geels y Voss este artículo propone como hipótesis central que la innovación en gobernanza permite identificar nodos o sinergías locales que, en un contexto multinivel de impacto local-global, pueden articular intereses entre los sectores estatal, empresarial y ambiental. La primera parte de este texto se concentra en comprender el desarrollo actual fenómeno del nacionalismo energético, mencionando algunas particularidades del mismo en América Latina. La segunda parte explica un marco conceptual sobre innovación en gobernanza para argumentar la importancia de ámbito local en este contexto. La última parte caracteriza la gobernanza ambiental, así como algunas de sus principales tensiones en países en vía de desarrollo.

This paper develops the structural budget balance methodology, adopted for use in the Chilean public sector. The structural balance methodology adjusts fiscal accounts so they reflect changes in net worth and makes it possible to isolate changes in fiscal policy resulting from the main exogenous factors determining fiscal revenues: GDP and copper price. This facilitates the analysis and evaluation of fiscal policy in Chile, which, since 2000, has focused on achieving a structural budget surplus, thus ensuring the existence of counter-cyclical fiscal policy in a framework of robust fiscal accounts.

La pre-eclampsia/eclampsia requiere tanto cuidado en el puerperio como antes del parto. El trabajo de parto, la anestesia y el sangrado son los factores que agravan la condición de este tipo de pacientes y por ello es necesario tener criterios muy claros para el manejo de esta situación. Presentamos una guía de manejo.

La composición química aproximada y la energía de las especies acompañantes del camarón utilizadas para consumo humano y animal se estudió en Alvarado, Vereacruz (Golfo de México). Cinco muestreos se realizaron entre septiembre de 1994 y marzo de 1995 en barcos camaroneros. Las muestras se congelaron a bordo para los análisis de laboratorio de la porción comestible. Los resultados indicaron 16 familias, 22 especies de peces y 1 molusco (calamar). Después de la humedad, la fracción química más abundante fue la proteína cruda con valores entre 14.3 y 19.6%. Los hidratos de carbono fueron desde 2.1 a 7.4%. El extracto etéreo (lípidos) fue menos abundante pero variable numéricamente (0.5 a 3.8%), las cenizas se cuantificaron entre 0.10 y 0.24%. La energía presentó la menor variación numérica (4.5 a 5.2 kcal/g). 12 especies son empleadas como alimento animal y solo Pristipomoides aquilonaris se reportó como de uso exclusivo para este propósito; la composición química fue similar a la de las especies de consumo humano. Anchoa hepsetus, Synodus foetens, Cynoscion arenarius, Upeneus parvus y Trichiurus lepturus, se recomiendan para alimentación humana, especialmento por su bajo costo en la costa del Golfo de México.Chemical composition and energy content of the shrimp by-catch used for human and livestock consumption were studied in Alvarado, Veracruz (Gulf of Mexico). Five on-board samplings were done between September 1994 and March 1995 on shrimp ships off Veracruz. The samples were frozen on board for laboratory analysis of the edible portion, they included 16 families and 22 species of fishes and 1 mollusc (squid). After moisture, the crude protein was the most abundant chemical fraction (14.3 and 19.6%); carbohydrates were numerically variable in all groups (2.1 to 7.4%); ether extract (lipids) was less abundant but variable (0.5 to 3.8%), ashes were 0.10 to 0.24%. Crude energy was less variable numerically (4.5 to 5.2 kcal/g); 12 species are used as animal feed and only Pristipomoides aquilonaris was reported as exclusively used for this purpose: chemical composition was similar in species used for human and for livestock consumption; Anchoa hepsetus, Synodus foetens, Cynoscion arenarius, Upeneus parvus and Trichiurus lepturus are recomended for human consumption, specially for low economic level areas of Gulf of Mexico.

Laser-driven plasma waves were proposed as compact electron accelerators [1] owing to their ability to produce longitudinal accelerating ¯elds several orders of magnitude higher than those attainable in conventional accelerators. A promising implementation relies on "broken" plasma waves driven by a laser pulse shorter than half the plasma period [2]. In the absence of intense laser pulses of the required duration, previous experiments [3] - [13] drew on longer (several-10-fs) driver pulses. Under these circumstances, monoenergetic electron acceleration is preceded by a nonlinear interaction of the laser pulse with the relativistic plasma [14], which shortens its duration into the required domain. Longer-than-optimal driver pulses compromise e±ciency as well as reproducibility, and result in copious amounts of low-energy electrons accompanying the monoenergetic emission with an exponentially-decaying spectrum, forming a "thermal" background. Here, we report the first electron accelerator based on high-density plasma waves driven with laser pulses ¯tting in one half of the plasma period. Direct excitation of a broken plasma wave permits monoenergetic electron acceleration virtually free of thermal background for the first time. In our experiments, 5-terawatt, 8-femtosecond laser pulses yield electron bunches up to energies of 25 MeV. The dramatically reduced °ux of low-energy electrons as compared to earlier experiments also manifests itself in a strongly-reduced secondary radiation emerging from the accelerator and o®ers the potential for enhancing e±ciency and stability with more intense driver pulses.

Particle pulses generated by laser-plasma interaction are characterized by ultrashort duration, high particle density, and sometimes a very strong accompanying electromagnetic pulse (EMP). Therefore, beam diagnostics different from those known from classical particle accelerators such as synchrotrons or linacs are required. Easy to use single-shot techniques are favored, which must be insensitive towards the EMP and associated stray light of all frequencies, taking into account the comparably low repetition rates and which, at the same time, allow for usage in very space-limited environments. Various measurement techniques are discussed here, and a space-saving method to determine several important properties of laser-generated electron bunches simultaneously is presented. The method is based on experimental results of electron-sensitive imaging plate stacks and combines these with Monte Carlo-type ray-tracing calculations, yielding a comprehensive picture of the properties of particle beams. The total charge, the energy spectrum, and the divergence can be derived simultaneously for a single bunch.

Ivan IV “The Terrible” was the first Tsar of all Russias and wascrowned in 1547. He extended Russian territories and opened the route to Siberia in successfulcampaigns against Tartars. He increased his personal power to the point of generating anautocracy that isolated him progressively from the council of Boyars. He had a complexpersonality and his acts were impregnated by a profound religiousness, episodes of rage, moodchanges and a sense of “personal fate”. All these traits configure the controversial “temporal lobepersonality”. The possible association between these personality traits and the eventual epilepsythat Ivan IV could suffer, is discussed. This association is called “temporal lobe syndrome”.Considering the mood changes, with severe irritability and episodes of control loss alternated withfeelings of guilt, sadness and isolation, another possibility is that the Tsar had an affective bipolardisorder or, less probably, a personality disorder (Rev Med Chile 2006; 134: 1465-69).(

Ivan IV "The Terrible" was the first Tsar of all Russias and was crowned in 1547. He extended Russian territories and opened the route to Siberia in successful campaigns against Tartars. He increased his personal power to the point of generating an autocracy that isolated him progressively from the council of Boyars. He had a complex personality and his acts were impregnated by a profound religiousness, episodes of rage, mood changes and a sense of "personal fate". All these traits configure the controversial "temporal lobe personality". The possible association between these personality traits and the eventual epilepsy that Ivan IV could suffer, is discussed. This association is called "temporal lobe syndrome". Considering the mood changes, with severe irritability and episodes of control loss alternated with feelings of guilt, sadness and isolation, another possibility is that the Tsar had an affective bipolar disorder or, less probably, a personality disorder