Density-Temperature-Softness Scaling of the Dynamics of Glass-forming Soft-sphere Liquids

The principle of dynamic equivalence between soft-sphere and hard-sphere fluids [Phys. Rev. E \textbf{68}, 011405 (2003)] is employed to describe the interplay of the effects of varying the density n, the temperature T, and the softness (characterized by a softness parameter {\nu}^{-1}) on the dynamics of glass-forming soft-sphere liquids in terms of simple scaling rules. The main prediction is that the dynamic parameters of these systems, such as the {\alpha}-relaxation time and the long-time self-diffusion coefficient, depend on n, T, and {\nu} only through the reduced density n^\ast \equiv n{\sigma}^{3}_{HS}(T, {\nu}),where the effective hard-sphere diameter {\sigma}_{HS}(T, {\nu}) is determined, for example, by the Andersen-Weeks-Chandler condition for soft-sphere-hard-sphere structural equivalence. A number of scaling properties observed in recent simulations involving glass-forming fluids with repulsive short range interactions are found to be a direct manifestation of this general dynamic equivalence principle. The self-consistent generalized Langevin equation (SCGLE) theory of colloid dynamics is shown to accurately capture these scaling rule

General Non-equilibrium Theory of Colloid Dynamics

A non-equilibrium extension of Onsager's canonical theory of thermal fluctuations is employed to derive a self-consistent theory for the description of the statistical properties of the instantaneous local concentration profile n(r,t) of a colloidal liquid in terms of the coupled time evolution equations of its mean value n(r,t) and of the covariance {\sigma}(r,r';t) \equiv of its fluctuations {\delta}n(r, t) = n(r, t) - n(r, t). These two coarse-grained equations involve a local mobility function b(r, t) which, in its turn, is written in terms of the memory function of the two-time correlation function C(r, r' ; t, t') \equiv <{\delta}n(r, t){\delta}n(r',t')>. For given effective interactions between colloidal particles and applied external fields, the resulting self-consistent theory is aimed at describing the evolution of a strongly correlated colloidal liquid from an initial state with arbitrary mean and covariance n^0(r) and {\sigma}^0(r,r') towards its equilibrium state characterized by the equilibrium local concentration profile n^(eq)(r) and equilibrium covariance {\sigma}^(eq)(r,r'). This theory also provides a general theoretical framework to describe irreversible processes associated with dynamic arrest transitions, such as aging, and the effects of spatial heterogeneities

OBTAINING THE BUDGET CONTINGENCY RESERVE THROUGH THE MONTE CARLO METHOD: STUDY OF A FERRY CONSTRUCTION PROJECT

The naval sector of new construction is characterised by high cost programmes and a low degree of definition in the stages of tendering. With these requirements, an initial, highly-competitive budget should be developed with acceptable risk. For this reason, it is usual in this field for a budget Contingency Reserve to be defined, in order to cover probable range increments, as well as probable deviations that could trigger economic losses. The budget Contingency Reserve estimate is usually carried out based on shipyard experience. However, problems arise when the shipyard does not have enough experience in the concrete type of vessel to be built. In this research, the use of an extension of the triangular Monte Carlo distribution model is proposed, with the aim of calculating the likelihood of complying with the calculated budget. From this result, a Contingency Reserve that provides enough security to execute the project within the limits of the economic risk defined by the organization can be calculated. The proposal introduced in this study allows managers to obtain a more optimal estimate of the Contingency Reserve, therefore reducing economic risks

Projections of Heat Waves Events in the Intra-Americas Region Using Multimodel Ensemble

Significant accelerated warming of the Sea Surface Temperature of 0.15°C per decade (1982–2012) was recently detected, which motivated the research for the present consequences and future projections on the heat index and heat waves in the intra-Americas region. Present records every six hours are retrieved from NCEP reanalysis (1948–2015) to calculate heat waves changes. Heat index intensification has been detected in the region since 1998 and driven by surface pressure changes, sinking air enhancement, and warm/weaker cold advection. This regional warmer atmosphere leads to heat waves intensification with changes in both frequency and maximum amplitude distribution. Future projections using a multimodel ensemble mean for five global circulation models were used to project heat waves in the future under two scenarios: RCP4.5 and RCP8.5. Massive heat waves events were projected at the end of the 21st century, particularly in the RCP8.5 scenario. Consequently, the regional climate change in the current time and in the future will require special attention to mitigate the more intense and frequent heat waves impacts on human health, countries’ economies, and energy demands in the IAR

Características morfológicas de huella vacunal del BCG en estudiantes de medicina

Con el objetivo de conocer la caracterización cuali-cuantitativa de la huella de la vacunación con el BCG administrada al nacimiento, como indicador de potencialidades inmunológicas de forma temporal o permanente, hemos realizado un trabajo en estudiantes de Medicina, de edades entre 18 y 20 años, Se identificó presencia o no de huella y se midieron los diámetros transversales y longitudinales de las lesiones residuales, y se informó el promedio de ambas lecturas. A un subgrupo, se le realizó cuantificación de anticuerpos anti HBs mediante método inmunoenzimático, después de dosis de refuerzo de 20 μgvacuna de hepatitis B. En 103 de 123 (83,7%) de los estudiantes que habían recibido el BCG, se logró identificar huella de la vacuna, con un diámetro promedio de7.74mm, DS de3.85 y CV de49.7 % Los factores inmunológicos que justifican la huella de la vacuna aplicada en condiciones standard y de buenas prácticas, tienen una base genética que es totalmente individual, que demuestra la gran desviación standard observada. En elgrupo al que se cuantificó, anti HBs, todos tenían respuesta al BCG, y tuvieron también, una magnífica respuesta de memoria inmunológica al HBsAg (987±240 UI/L promedio). Nos proponemos, como parte de un proyecto de investigación de nuestro Centro, realizar estudios prospectivos a niños de diferentes edades; y donde no aparezca huella del BCG, estudiar respuesta inmune para otras vacunas del PAI. Palabras clave: BCG, respuesta inmune, memoria inmunológica, anti-HBs, huella de BCG

Cultivo y crecimiento de dos especies de diatomeas bentónicas aisladas del Salar del Huasco (Norte de Chile, 20° S) a diferentes condiciones de temperatura, luz y nutrientes

Benthic diatoms are cultured usually under laboratory conditions to be used as a food source for other organisms, ofaquaculture interest or for biotechnological applications. Laboratory experiments demonstrate the incidence of the physicaland chemical variables on abundance and growth rates of diatoms. While macronutrients are usually selected and dosed intocommon culture mediums to meet the general requirements of a wide range of diatoms, the availability and optimizationof micronutrients are more susceptible to each organism’s particular physiological conditions. The aim of this study was tocharacterize the growth of two species of benthic diatoms isolated from the Salar de Huasco in batch cultures at differentconditions of temperature (10, 15 and 20 °C), light intensity (40, 80 and 120 ?mol m-2 s-1) and concentrations of silica (1.06x 10-4 M Na2SiO3 x 9H2O and 2.12 x 10-4 M Na2SiO3 x 9H2O) and selenium (10-8 M H2SeO3) in f/2 medium, on a lightdarkcycle of 18:6 h. Both Nitzschia epithemioides Grunow in Cleve &amp; Grunow (1880) as Nitzschia sp. showed highermaximum cell densities (692800 ± 107704 and 649600 ± 68942 cells ml-1, respectively) and exponential growth rates(1.80±0.56 and 0.97±0.32 div. d-1, respectively) at the highest temperature (20°C). The light intensity to which the cultureswere exposed had no effect on cell density and exponential growth rate in both taxa. Regarding to nutrients, an increasein silicates concentrations on the culture medium could promote the growth of N. epithemioides and Nitzschia sp. since atendency was observed to higher cell densities (1.08 x 106 ± 84,639 and 1.32 x 106 ± 109,038 cells ml-1, respectively) andexponential growth rates (1.98 ± 0.44 and 0.95 ± 0.18 div. d-1, respectively) with respect at the normal f/2 medium and f/2medium plus selenium. Simultaneous addition of silicate and selenium to the culture medium increased the maximum celldensity of the two strains under study, but this increase was significant (p = 0.05) only for N. epithemioides and amongthe normal f/2 medium (719200 ± 116895 cells ml-1) and the f/2 medium with double the amount of silicate and selenium(1498800 ± 209599 cells ml-1). However, the exponential growth rates were not significantly different when comparedto those of the control (without the addition of silicate and selenium). In conclusion both N. epithemioides and Nitzschiasp shown an increased cell density and exponential growth rate at 20 °C. The different light intensities not significantlyinfluenced the growth of both taxa. An increase in the concentration of silicates or simultaneous increase in silicatesand selenium in the culture medium can be considered as possible strategy to increase cell density of benthic diatom N.epithemioides in batch cultures.de alimento de otros organismos de interés acuícola o para aplicaciones biotecnológicas. Experimentos de laboratoriodemuestran la incidencia de las variables físicas y químicas sobre la abundancia y tasas de crecimiento de las diatomeas.Mientras los macronutrientes están generalmente seleccionados y dosificados en los medios de cultivo más comunespara satisfacer los requerimientos generales de un amplio rango de diatomeas, la disponibilidad y optimización demicronutrientes son más susceptibles a las condiciones fisiológicas particulares de cada organismo. El objetivo de esteestudio fue caracterizar el crecimiento de dos especies de diatomeas bentónicas aisladas del Salar de Huasco en cultivostipo batch, a diferentes condiciones de temperatura (10, 15 y 20 °C), intensidad de la luz (40, 80 y 120 ?mol m-2 s-1), y concentraciones de sílice (1.06 x 10-4 M Na2SiO3 x 9H2O y 2.12 x 10-4 M Na2SiO3 x 9H2O) y selenio (10-8 M H2SeO3)en medio f/2, a un ciclo 18:6 h luz-oscuridad. Tanto Nitzschia epithemioides Grunow in Cleve &amp; Grunow (1880) comoNitzschia sp, exhibieron las mayores densidades celulares máximas (692800 ± 107704 y 649600 ± 68942 células mL-1,respectivamente) y tasas de crecimiento exponencial (1,80 ± 0,56 y 0,97 ± 0,32 div. d-1, respectivamente) a la temperaturamás elevada (20 °C). La intensidad de luz a la cual los cultivos fueron expuestos no afectó la densidad celular y tasa decrecimiento exponencial en ambos taxa. En cuanto a los nutrientes, un incremento en la concentración de silicatos en elmedio de cultivo, podría favorecer el crecimiento de N. epithemioides y Nitzschia sp. ya que se observó una tendenciaal aumento en la densidad celular (1,08 x 106 ± 84.639 y 1,32 x 106 ± 109.038 células mL-1, respectivamente) y tasa decrecimiento exponencial (1,98 ± 0,44 y 0,95 ± 0,18 div. d-1, respectivamente) con respecto a los medios f/2 normal y f/2más selenio. La adición simultanea de silicato y selenio al medio de cultivo aumentó las densidades celulares máximas delas dos cepas bajo estudio, pero este aumento fue significativo (p = 0,05) sólo para N. epithemioides y entre los medios decultivo f/2 normal (719200 ± 116895 células mL?1) y medio f/2 con el doble de silicato y selenio (1498800 ± 209599 célulasmL-1). Sin embargo, las tasas de crecimiento exponencial no tuvieron diferencias significativas con el control (sin adiciónde silicato y selenio). En conclusión tanto N. epithemioides y Nitzschia sp. muestran un aumento en la densidad celular yla tasa de crecimiento exponencial a 20 °C. Las diferentes intensidades de luz evaluadas no influyeron significativamenteen el crecimiento de ambos taxa. Un aumento en la concentración de silicatos o aumento simultáneo de silicatos y selenioen el medio de cultivo puede ser considerado como posible estrategia para incrementar la densidad celular de la diatomeabentónica N. epithemioides en cultivos discontinuos

Fisiopatología del paciente quemado

RESUMEN Las quemaduras extensas son uno de los traumas más severos al cual puede verse expuesto un individuo, este tipo de trauma tiene efectos locales y sistémicos bien establecidos pero no muy bien comprendidos por la mayoría del personal de salud. Pueden comprometer directa o indirectamente a casi todos los sistemas del organismo. El objetivo de éste artículo es ofrecer una explicación sencilla y sistemática, que permita al lector entender mejor como responde el cuerpo humano ante un trauma extenso por quemadura, se espera que esta lectura mejore la comprensión de la fsiopatología de este tipo de trauma y por lo tanto se manifeste en el actuar diario del personal de salud. Palabras clave: Quemaduras, fsiopatología, cirugía plástica ABSTRACT An extensive burn wound is among the most severe trauma a patient can be exposed to, it has well defned local and systemic effects; however, these effects are little understood by most of the health care personal. This injury can compromise directly or indirectly every system in the body. The objective of this article is to offer a simple and systematic review that allows the reader a better understanding of the response of the human body after an extensive burn injury, it is expected that this paper contributes to the better understanding of the physiology of this type of trauma and therefore be expressed in the daily work of the health care personal. Keywords: Burns, physiopathology, plastic surger

Simplified Self-Consistent Theory of Colloid Dynamics

One of the main elements of the self-consistent generalized Langevin equation (SCGLE) theory of colloid dynamics [Phys. Rev. E {\bf 62}, 3382 (2000); ibid {\bf 72}, 031107 (2005)] is the introduction of exact short-time moment conditions in its formulation. The need to previously calculate these exact short-time properties constitutes a practical barrier for its application. In this note we report that a simplified version of this theory, in which this short-time information is eliminated, leads to the same results in the intermediate and long-time regimes. Deviations are only observed at short times, and are not qualitatively or quantitatively important. This is illustrated by comparing the two versions of the theory for representative model systems.Comment: 1 text archive, 3 figure

Fisiopatología del paciente quemado

RESUMEN Las quemaduras extensas son uno de los traumas más severos al cual puede verse expuesto un individuo, este tipo de trauma tiene efectos locales y sistémicos bien establecidos pero no muy bien comprendidos por la mayoría del personal de salud. Pueden comprometer directa o indirectamente a casi todos los sistemas del organismo. El objetivo de éste artículo es ofrecer una explicación sencilla y sistemática, que permita al lector entender mejor como responde el cuerpo humano ante un trauma extenso por quemadura, se espera que esta lectura mejore la comprensión de la fsiopatología de este tipo de trauma y por lo tanto se manifeste en el actuar diario del personal de salud. Palabras clave: Quemaduras, fsiopatología, cirugía plástica ABSTRACT An extensive burn wound is among the most severe trauma a patient can be exposed to, it has well defned local and systemic effects; however, these effects are little understood by most of the health care personal. This injury can compromise directly or indirectly every system in the body. The objective of this article is to offer a simple and systematic review that allows the reader a better understanding of the response of the human body after an extensive burn injury, it is expected that this paper contributes to the better understanding of the physiology of this type of trauma and therefore be expressed in the daily work of the health care personal. Keywords: Burns, physiopathology, plastic surger