Coexistiendo con el riesgo: potenciando el desarrollo de la resiliencia urbana vinculando los métodos locales de la reducción del riesgo de desastres descendentes y ascendentes

El Perú se enfrenta a peligros naturales imprevisibles y repetitivos que se convierten en desastres cuando comunidades vulnerables están expuestas a ellos. El incontrolable crecimiento urbano incrementó los impactos del riesgo de desastres. En el distrito de Chosica, los asentamientos informales localizados en quebradas tienen que coexistir con recurrentes huaycos e inundaciones intensificadas por el fenómeno del Niño. El asentamiento Nicolás de Piérola, ubicado en la quebrada del Quirio, es la comunidad más poblada de Chosica expuesta a eventos repetitivos y extremos de huaycos. Sin embargo, las medidas descendentes y ascendentes implementadas no han producido un progreso sustancial durante los años, ya que se centran en las respuestas de emergencia. Con el apoyo de los datos cualitativos de informes anteriores, entrevistas semiestructuradas, encuestas, un taller y la observación del trabajo de campo, se identifican la amenaza, la exposición y las vulnerabilidades del asentamiento en una cadena de impacto del riesgo. Posteriormente, se analizan la gestión local del riesgo, acciones y percepciones del riesgo para identificar las brechas entre las vulnerabilidades y las medidas. Por último, se ofrecen recomendaciones basadas en las capacidades locales de adaptación, los conocimientos y los recursos para mejorar la Resiliencia Urbana.Peru is a country faced with unpredictable and repetitive natural hazards, which turns into disasters when vulnerable societies are exposed to them. The uncontrollable urban growth incremented the disaster risk impacts since families squatted hazard-prone areas. In Chosica district, informal settlements established in ravines have to coexist with recurrent debris flows and floods intensified by the ENSO phenomenon. Despite the several attempts to accomplish urban resilience, the actions that are being implemented are not achieving its full potential as the local community is not integrated or engaged enough along with the processes of disaster risk reduction. If the exposure of settlements is eliminated, then negative consequences after a hazard has stroked would not exist. However, in a high-density city where most of the affordable and safe land is occupied, or relocation measures are not feasible for all communities, there is a need for an alternative approach which allows informal settlements to coexist with the risks that they are inevitably prone to. Nicolas de Pierola human settlement located in Quirio ravine is the most populated community in Chosica, which has faced repetitive and extreme debris flow events. Nonetheless, the implemented top-down and bottom-up measures have not produced substantial progress during the years since they are focused on emergency responses. Supported by qualitative data from previous reports, semi-structured interviews, surveys, a workshop, and fieldwork observation, the hazard, exposure, and vulnerabilities of the settlement are framed under the impact chain of risk. Later, local risk management, actions, and risk perceptions are analyzed to identify the gaps between vulnerabilities and measures. Finally, recommendations are provided based on adaptive local capacities, knowledge, and resources to enhance urban resilience.Perú. Programa Nacional de Becas y Crédito Educativa (Pronabec). Beca Alepron

Search for gamma-ray bursts in the GeV energy range at Mt. Chacaltaya (5200 m)

Observations of gamma-ray bursts in the 1 GeV–1 TeV energy region are of great interest for the understanding of these mysterious events. The detection of GeV-TeV gamma-ray bursts is feasible using extensive air shower arrays monitoring the fluctuations of the single-particle counting rate. The sensitivity is strongly increased working at mountain altitudes, in particular above 5000 m. In this paper we discuss the possibility to exploit the existing BASJE EAS array operating at Mt. Chacaltaya (Bolivia) at 5200 m a.s.l. Simulations of electromagnetic showers in the atmosphere have been performed in order to evaluate the sensitivity of this experiment to detect gamma ray bursts of different time duration, spectrum slope and energy cut-off. The detector can observe events of energy fluence F(ED1 GeV )A few 1025 erg cm22, comparable to that measured by satellite instruments during the most intense gamma-ray bursts, provided they occurr at low zenith angles and assuming that the energy spectrum at least extends up to A1 TeV. In the case of events below the sensitivity of the experiment, upper limits on the high-energy tail of the spectrum can be obtained by measurements in coincidence with satellite observations

Correlación entre estadios de maduración carpal y estadios de desarrollo dental en Centro Médico “SuMédico”.

Introducción: Los seres humanos tienen cambios notables durante el crecimiento, debido a esto se han descrito diferentes métodos para analizar la maduración ósea y dental, que son necesarios para determinar un buen diagnóstico y un correcto plan de tratamiento durante los procedimientos de ortodoncia. Objetivo: Evaluar la correlación entre los estadios de maduración carpal y estadios de desarrollo dental. Materiales y métodos: Es un estudio descriptivo de tipo correlacional y transversal, en el que se usó una muestra de 81 pacientes que fueron atendidos en los últimos 4 meses en el centro médico “SuMédico”, respetando los criterios de inclusión y exclusión , respectivamente. Se utilizó el método de maduración carpal de Björk, Grave and Brown, el método de maduración cervical de Baccetti y para desarrollo dental se utilizó el de Demirjian. Resultados: Al analizar las radiografías de los 81 pacientes se encontró mediante el coeficiente de correlación de Pearson con un valor de 0.82 una alta correlación entre las variables. Conclusiones: Se concluyó que existe una alta correlación entre los estadios de maduración dental con los estadios de maduración carpal.Introduction: Human beings have remarkable changes during growth, because of this have described different methods to analyze bone and dental maturation, which are necessary to determine a good diagnosis and a correct treatment plan during orthodontic procedures. Objective: Evaluate the correlation between stages of carpal maturation and stages of dental development. Materials and Methods: A descriptive study of correlational and transverse type, in which a sample of 81 patients who were attended in the last 4 months in medical center "SuMédico” were used, respecting the inclusion and exclusion criteria. For carpal maturation was used the method of Björk, Grave and Brown, Baccetti's method for cervical maturation and the method of Demirjian was used for dental development. Results: Analyzing the radiographs of the 81 patients, was found a high correlation between the variables using the Pearson correlation coefficient with a value of 0.82. Conclusions: There is a high correlation between stages of dental maturation and stages of carpal maturation

Evaluación de Diferentes Concentraciones de Tricaína (MS-222) en el Transporte de Chitas (Anisotremus scapularis) Juveniles

The use of tricaine (MS-222) as sedative agent for transporting of Anisotremus scapularis juveniles was evaluated. A simulated transport of 24 hours was performed at two temperatures (15 and 19 °C) using the anaesthetic concentrations of 0, 15, 20 and 25 mg.L-1 in polyethylene bags (50% seawater - 50% pure oxygen). At the beginning and the end of the simulation temperature, dissolved oxygen saturation, pH and ammonia excretion rate were monitored. On fishes, the loss of balance (%) and survival (%) were monitored at the end of the simulation and after an additional recovery time of 24 hours. The results showed that use of tricaine favours the reduction of ammonia excretion, however, tricaine doses over 20 mg.L-1 significantly increase the loss of balance in fish. Furthermore, the sedating effect is magnified at lower temperature (15 °C). On the other hand, the water pH is affected showing an average decrease of 1.44 during the transport simulation in all treatments. Based on the results, transport of Peruvian grunt juveniles using tricaine in a dose of at 15 mg.L-1 at 19 °C is recommended.Se evaluó el uso de la tricaína (MS-222) como agente sedante para su uso en el transporte de juveniles Anisotremus scapularis. Para ello, se realizó un transporte simulado de 24 horas a dos temperaturas (15 y 19 °C) usando concentraciones del anestésico de 0, 15, 20 y 25 mg.L-1 en bolsas de polietileno (50% agua de mar - 50% oxígeno puro). Se monitoreó, tanto al inicio como al final de la simulación, la temperatura, saturación de oxígeno disuelto, pH y tasa de excreción individual de amonio. En los peces se evaluó la pérdida de equilibrio (%) y sobrevivencia (%) al término de la simulación y luego de un tiempo de recuperación de 24 horas adicionales. Los resultados muestran que el uso de tricaína favorece la disminución de la excreción de amonio; sin embargo, dosis superiores a 20 mg.L-1 de tricaína incrementan considerablemente la perdida de equilibrio. Además, el efecto de sedación es más intenso a temperaturas más bajas (15 °C). Por otro lado, el pH del agua se ve afectado mostrando una disminución promedio de 1.44 durante la simulación del transporte en todos los tratamientos. En base a los resultados se recomienda el transporte de juveniles de chita a 19 °C con uso de tricaína a 15 mg.L-1

Characteristics of the coastline in the Huacho Pilot Area (spring 2019)

Este estudio proporciona información sobre evaluaciones de variables oceanográficas y de invertebrados en las playas de la isla Don Martín (IDM) y al sur de Huacho. En la isla Don Martín, se obtuvieron altos valores de oxígeno disuelto en superficie, cuyos rangos estuvieron entre 3,67 y 7,95 mg/L, con promedio de 5,84 mg/L. El promedio de salinidad fue de 35,17 (est. IDM1) y 35,19 (est. IDM3). La concentración de clorofila en la IDM1 fue 0,237 ±0,064 μg/L y en la IDM3 fue 0,013 ±0,023 μg/L. En la zona sur de Huacho en las estaciones 16, 17 y 18, entre 3 y 5 metros de profundidad, la temperatura varió de 14,5 a 14,8 °C, pH de 7,86 a 7,94 y oxígeno disuelto entre 4,61 y 6,68 mg/L. En ambas zonas de estudio se identificaron invertebrados como caracolito (Tegula luctuosa), caracol negro (Thaisella chocolata), cangrejo jaiva (Cancer porteri), macroalgas como algas rojas (Rhodymenia howeana). Se concluye que los valores físico-químicos registrados guardan similitud con los determinados en estudios previos, en diferentes épocas del año en las costas de Huacho.ABSTRACT: Our study provides information on evaluations of oceanographic variables and invertebrates on the beaches of Don Martin Island (IDM) and south of Huacho. High levels of dissolved oxygen were recorded in the surface waters of IDM, with concentrations ranging from 3.67 to 7.95 mg/L and an average of 5.84 mg/L. The average salinity was 35.17 (station IDM1) and 35.19 (station IDM3). The chlorophyll concentration in IDM1 was 0.237 ±0.064 μg/L and in IDM3 it was 0.013 ±0.023 μg/L. The temperature in southern Huacho, measured at stations 16, 17, and 18 and depths of 3 to 5 m, ranged from 14.5 to 14.8°C, with pH levels ranging from 7.86 to 7.94, and dissolved oxygen concentrations ranging from 4.61 to 6.68 mg/L. In both study areas, various invertebrates such as Tegula luctuosa, Thaisella chocolata, Cancer porteri, were identified, along with macroalgae such as Rhodymenia howeana. The recorded physicochemical values were found to be consistent with those reported in previous studies conducted at different times of the year along the Huacho coast

Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory

Atmospheric parameters, such as pressure (P), temperature (T) and density, affect the development of extensive air showers initiated by energetic cosmic rays. We have studied the impact of atmospheric variations on extensive air showers by means of the surface detector of the Pierre Auger Observatory. The rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find that the observed behaviour is explained by a model including the effects associated with the variations of pressure and density. The former affects the longitudinal development of air showers while the latter influences the Moliere radius and hence the lateral distribution of the shower particles. The model is validated with full simulations of extensive air showers using atmospheric profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle Physic

Sutam y komonil: defensa territorial y existencia colectiva de comunidades poqomchi’-q’eqchi’ en Baja Verapaz, Guatemala

"En este artículo se ofrece una aproximación analítica a la dimensión cultural de la defensa territorial de comunidades poqomchi’-q’eqchi’ en Baja Verapaz, Guatemala, con base en una investigación cualitativa realizada desde la perspectiva de la investigación-acción participante. Se analizan dos nociones estructurales: sutam —territorio— y komonil —dimensión y organización colectiva de la existencia—, entendidas como parte de sus conocimientos culturales, su memoria y esperanzas colectivas en relación con el territorio y la política. Se trata de la defensa de los bienes necesarios para reproducir la vida en comunidad, así como sus modos particulares de ver y organizar la vida frente a experiencias de desplazamiento y amenazas de proyectos hidroeléctricos"

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{$6\times 10^{19}$eV}. The anisotropy was measured by the fraction of arrival directions that are less than $3.1^\circ$ from the position of an active galactic nucleus within 75 Mpc (using the V\'eron-Cetty and V\'eron $12^{\rm th}$ catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is $(38^{+7}_{-6})$, compared with $21$ expected for isotropic cosmic rays. This is down from the early estimate of $(69^{+11}_{-13})$. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201

Growth and physiological rates of Peruvian grunt Anisotremus scapularis (Tschudi, 1846): Technical bases for cultivation

El presente estudio proporciona información sobre el crecimiento y tasas fisiológicas (consumo de oxígeno, consumo de alimento y excreción de amonio) así como del tamaño óptimo de partícula de alimento para A. scapularis (chita) en condiciones de laboratorio a diferentes temperaturas de aclimatación. Los resultados obtenidos muestran que tiene un crecimiento similar cuando son cultivados a 17 y 22 °C, alcanzando tallas mínimas de captura (24 cm) en 24 y 22 meses de cultivo, respectivamente. Además, las tasas fisiológicas de A. scapularis a 22 °C fueron significativamente mayores (p <0,05), respecto a 17 y 14 °C. Estos resultados indican que probablemente los procesos metabólicos de la especie se encuentren en un rendimiento sub-óptimo en individuos acondicionados a 22 °C. En el estadio incipiente de las investigaciones acuícolas en A. scapularis, estos resultados servirán como línea base para el dimensionamiento o adaptación de la infraestructura experimental o piloto así como para su manejo en sistemas de cultivo. En este sentido, una mayor inversión energética en procesos de mantenimiento podría comprometer la energía disponible para el crecimiento. Este estudio permite identificar retos productivos para lograr un paquete acuícola que genere el impulso de una actividad de cultivo productiva.ABSTRACT: We worked with Anisotremus scapularis under laboratory conditions at different acclimatization temperatures (14, 17 and 22 °C). The results provide information on growth and physiological rates (oxygen and feed consumption, ammonia excretion) and optimal particle size of food. The species presented similar growth at 17 and 22 °C, reached the minimal catch size (24 cm) in 24 months at 17 °C and 22 months at 22 °C. Physiological rates at 22 °C were significantly higher (p <0.05) in comparison with 17 and 14 °C. These results indicate that probably the metabolic processes of the species are found with a sub-optimal performance in individuals conditioned at 22 °C. In that sense, greater energy investment in maintenance processes could compromise the energy available for growth. This study allow us to identify productive challenges in order to develop an aquaculture package that generates the impulse of the cultivation of this species

Optimización del tratamiento térmico para la inducción al desove de Argopecten purpuratus (Mollusca: Bivalvia)

Based on methodologies currently used in commercial hatcheries, four thermic treatments were compared to induce the gametes expulsion of Argopecten purpuratus. The treatments evaluated included: 1) gradual increase in temperature, 2) gradual decrease, 3) 5 °C thermal-shock, 4) 10 °C thermal-shock and 5) control at constant temperature 16 °C. After induction, the number of fertilized oocytes in each treatment was estimated. The results show that a gradual increase in temperature between 16 and 26 °C causes a significantly higher proportion of fertilized oocytes compared to other treatments