YSOVAR: Mid-infrared Variability in NGC 1333

As part of the Young Stellar Object VARiability (YSOVAR) program, wemonitored NGC 1333 for ∼35 days at 3.6 and 4.5 μm using theSpitzer Space Telescope. We report here on the mid-infrared variabilityof the point sources in the ∼10‧ × ∼20‧ areacentered on 03:29:06, +31:19:30 (J2000). Out of 701 light curves ineither channel, we find 78 variables over the YSOVAR campaign. Abouthalf of the members are variable. The variable fraction for the mostembedded spectral energy distributions (SEDs) (Class I, flat) is higherthan that for less embedded SEDs (Class II), which is in turn higherthan the star-like SEDs (Class III). A few objects have amplitudes(10–90th percentile brightness) in [3.6] or [4.5] > 0.2 mag; amore typical amplitude is 0.1–0.15 mag. The largest color changeis >0.2 mag. There are 24 periodic objects, with 40% of them beingflat SED class. This may mean that the periodic signal is primarily fromthe disk, not the photosphere, in those cases. We find 9 variableslikely to be “dippers,” where texture in the disk occultsthe central star, and 11 likely to be “bursters,” whereaccretion instabilities create brightness bursts. There are 39 objectsthat have significant trends in [3.6]–[4.5] color over thecampaign, about evenly divided between redder-when-fainter (consistentwith extinction variations) and bluer-when-fainter. About a third of the17 Class 0 and/or jet-driving sources from the literature are variableover the YSOVAR campaign, and a larger fraction (∼half) are variablebetween the YSOVAR campaign and the cryogenic-era Spitzer observations(6–7 years), perhaps because it takes time for the envelope torespond to changes in the central source. The NGC 1333 brown dwarfs donot stand out from the stellar light curves in any way except there is amuch larger fraction of periodic objects (∼60% of variable browndwarfs are periodic, compared to ∼30% of the variables overall).

Costumes e foros de Riba-Côa : normativa e sociedade

Tese de doutoramento, História (História Medieval), Universidade de Lisboa, Faculdade de Letras, 2014

Activities of an aqueous plant extract against Herpes simplex virus type 2 (HSV 2): role in virus replication and progeny yield

Tese de mestrado, Biologia Molecular e Genética, Universidade de Lisboa, Faculdade de Ciências, 2015

Development of novel antibacterial active, HaCaT biocompatible and biodegradable CA-g-P(3HB)-EC biocomposites with caffeic acid as a functional entity

We have developed novel composites by grafting caffeic acid (CA) onto the P(3HB)-EC based material and laccase from Trametes versicolor was used for grafting purposes. The resulting composites were designated as CA-g-P(3HB)-EC i.e., P(3HB)-EC (control), 5CA-g-P(3HB)-EC, 10CA-g-P(3HB)-EC, 15CA-g-P(3HB)-EC and 20CA-g-P(3HB)-EC. An FT-IR (Fourier-transform infrared spectroscopy) was used to examine the functional and elemental groups of the control and laccase-assisted graft composites. Evidently, 15CA-g-P(3HB)-EC composite exhibited resilient antibacterial activity against Gram-positive and Gram-negative bacterial strains, respectively. Moreover, a significant level of biocompatibility and biodegradability of the CA-g-P(3HB)-EC composites was also achieved with the human keratinocytes-like HaCaT cells and soil burial evaluation, respectively. In conclusion, the newly developed novel composites with multi characteristics could well represent the new wave of biomaterials for medical applications, and more specifically have promising future in the infection free would dressings, burn and/or skin regeneration field due to their sophisticated characteristics.

A comprehensive simulation study of slotted CSMA/CA for IEEE 802.15.4 wireless sensor networks

In this paper, we analyze the performance limits of the slotted CSMA/CA mechanism of IEEE 802.15.4 in the beacon-enabled mode for broadcast transmissions in WSNs. The motivation for evaluating the beacon-enabled mode is due to its flexibility for WSN applications as compared to the non-beacon enabled mode. Our analysis is based on an accurate simulation model of the slotted CSMA/CA mechanism on top of a realistic physical layer, with respect to the IEEE 802.15.4 standard specification. The performance of the slotted CSMA/CA is evaluated and analyzed for different network settings to understand the impact of the protocol attributes (superframe order, beacon order and backoff exponent) on the network performance, namely in terms of throughput (S), average delay (D) and probability of success (Ps). We introduce the concept of utility (U) as a combination of two or more metrics, to determine the best offered load range for an optimal behavior of the network. We show that the optimal network performance using slotted CSMA/CA occurs in the range of 35% to 60% with respect to an utility function proportional to the network throughput (S) divided by the average delay (D).

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in Portugal:

Methicillin-resistant Staphylococcus aureus (MRSA), a human pathogen confined to hospitals (HAMRSA) for over 30 years have been emerging worldwide in the last two decades as a leading cause of severe infections in healthy individuals in the community (CA-MRSA). Despite its clinical significance, in the beginning of our studies no information existed on the prevalence, and population structure of CA-MRSA in Portugal. Moreover, it remained to be clarified how CA-MRSA emerged in our country. In particular, it was not known if CA-MRSA emerged locally by acquisition of the staphylococcal cassette chromosome mec (SCCmec) by established methicillin-susceptible S. aureus (MSSA) in the community, if they were imported from abroad or have escaped from the hospital.(...)

Improving TCP Performance on CSMA/CA Connections

In IP networks, most of packets, that have been dropped, are recovered after the expiration of retransmission timeouts. These can result in unnecessary retransmissions and needless reduction of congestion window. An inappropriate retransmission timeout has a huge impact on TCP performance. In this paper we have proved that CSMA/CA mechanism can cause TCP retransmissions due to CSMA/CA effects. For this we have observed three wireless connections that use CSMA/CA: with good link quality, poor link quality and in presence of cross traffic. The measurements have been performed using real devices. Through tracking of each transmitted packet it is possible to analyze the relation between one-way delay and packet loss probability and the cumulative distribution of distances between peaks of OWDs. The distribution of OWDs and the distances between peaks of OWDs are the most important parameters of tuning TCP retransmission timeout on CSMA/CA networks. A new perspective through investigating the dynamical relation between one-way delay and packet loss ratio depending on the link quality to enhance the TCP performance has been provided.

Red de arrastre pelágica 124/1800 y resultados del filtrado de los paneles de malla 150 y 75 mm en la prspección de la vinciguerria Crucero BIC Jose Olaya Balandra 9910, del Callao a Chancay

Se presentaron los resultados de la modificación y adaptaciones de la red pelágica 124/1800 para la captura del recurso Vinciguerria.

Biología y pesquería del perico o dorado Coryphaena hippurus, febrero 2010

La prospección para evaluar la biología y pesquería de Coryphaena hippurus perico o dorado, se efectuó del 10 de febrero al 1 de marzo 2010, a bordo del BIC Imarpe V. El área de extracción fue de 4°59’32,8’’ a 10°15’20,1’’S y de 79°55’16,2’’ a 84°35’04,2’’W; la captura total fue 1.500,5 kg. La CPUE varió de 0,9 a 18,2 kg/Nº Anzuelos/1000*hora efectiva de pesca. Se encontró alta selección interespecífi ca del espinel superfi cial, al capturar 87,8% de perico y 8 especies de peces, tortugas y cefalópodos. El rango de tallas para hembras fue 79 - 141 cm de LT, en machos fue 100 - 157 cm LT. El factor de condición de Fulton en machos varió de 0,30 a 0,46 y en hembras de 0,32 a 0,40. Se determinó para hembras: L∞=148,92 cm, tasa de crecimiento anual (K) 1,081, se estimó t0 = -0,076 años, el Índice de performance Ǿ= 4,38; para machos, estos parámetros fueron L∞=169,75 cm, tasa de crecimiento anual (K) de 0,893, t0 = -0,115, índice de performance Ǿ= 4,40. La curva de crecimiento en talla para hembras, indica que a un año de edad la LT es 102,4 cm y en machos 107 cm. El máximo crecimiento en peso para hembras y machos fue a 1,5 años de vida. El Índice gonadosomático (IGS) fl uctuó de 3,2 a 4,6 mostrando comportamiento heterogéneo. La proporción sexual fue de 2:1 favorable a las hembras. La fecundidad parcial fue de 324.416 ovocitos por tanda de desove. La fecundidad relativa fue 56 ovocitos/ gramo de peso corporal. El tipo de alimento fue peces, cefalópodos y crustáceos con dominancia de Exocoetus volitans (%IRI = 31,6), Argonauta spp. (%IRI = 26,4) mostrando variaciones según zonas y tallas. El consumo de alimento fue 472,7 g/ind./día correspondiente a 7,4% de su peso corporal, presentando fl uctuaciones con respecto a la talla; alimentándose en horas de la mañana, con un máximo entre las 8:00 y 9:59 horas. Se encontraron 5.762 parásitos, identifi cándose 8 especies en cuatro taxas. La prevalencia parasitaria indica que Tentacularia coryphaenae y Bathycotyle coryphaenae alcanzan el 100%, seguido por Hysterothylacium sp. 62% y Caligus coryphaenae 46%. El mayor número de parásitos se encontró en el estómago. Los peces entre 96–100 cm de LT son los más parasitados. La mayor incidencia parasitaria se encontró en la zona norte, en el tramo Paita-Salaverry. Los registros de temperatura en la columna de agua fueron de 12,7 a 27,3 °C y las ATSM de 0,2 a 4,1 °C. Por el frente oceánico se observaron comportamientos térmicos cálidos asociados a las masas de Aguas Ecuatoriales Superfi ciales y Aguas Subtropicales Superfi ciales y por la zona costera se localizaron Aguas Costeras Frías tanto en Chimbote como en Chicama con temperaturas próximas a 22,0 °C. La concentración de oxígeno disuelto superfi cial se presentó favorable para el perico.

Karta öfver Helsingfors omgifningar upptagande delar af Helsinge, Sibbo, Esbo och Kyrkslätt m. fl. socknar

Mittakaava laskettu janamittakaavasta

La prière des naufragés : drame en 5 actes. [suivi de] Un mari en 150 : comédie-vaudeville en 1 acte. Livr. 157 / par MM. d'Ennery et Ferdinand Dugué ; par M. Émile de Najac

Collection : Théâtre contemporain illustré ; 156e et 157e livraisons

La prière des naufragés : drame en 5 actes. [suivi de] Un mari en 150 : comédie-vaudeville en 1 acte. Livr. 156 / par MM. d'Ennery et Ferdinand Dugué ; par M. Émile de Najac

Collection : Théâtre contemporain illustré ; 156e et 157e livraisons