Reproduction and structure of the population of the Chaetognath Parasagitta friderici in Guanabara Bay (Brazil) based on short term sampling

The aim of this study was to describe the total density, densities of developmental stages and the reproduction period of Parasagitta friderici. Weekly samples were collected at one station in the channel of Guanabara Bay, Rio de Janeiro, during one year. Three vertical hauls were made for each sample, and P. friderici was separated, the developmental stages were identified, and body length (BL), ovary length (OL) and seminal vesicle width (SVW) were measured. Throughout the year P. friderici was the most abundant chaetognath species occurring in all four developmental stages, the densities of which varied from week to week. Higher densities of adults occurred in the spring, followed by peaks of juveniles in the summer. Although P. friderici seems to reproduce continuously in Guanabara Bay, a reproductive peak was apparent during the spring. The intensification of reproduction during the spring, with juveniles occurring in the summer, seems to be related to the period of higher food supply during the rainy season and intrusions of the South Atlantic Central Water.O objetivo deste estudo foi descrever a densidade total, densidades dos estágios de desenvolvimento e o período reprodutivo de Parasagitta friderici. As coletas foram realizadas semanalmente durante um ano em uma estação no canal da Baía de Guanabara, Rio de Janeiro. Foram realizados três arrastos verticais em cada amostragem e, P. friderici foi separada, os estágios de desenvolvimento identificados e o comprimento do corpo, comprimento dos ovários e a largura da vesícula seminal foram medidos. Ao longo do ano, P. friderici foi a espécie de Chaetognatha mais abundante, ocorrendo em todos os quatro estágios de desenvolvimento, dos quais as densidades variaram entre as semanas. As densidades mais altas de adultos ocorreram na primavera seguidas de picos de juvenis no verão. Embora, P. friderici se reproduza continuamente na baía de Guanabara, um pico reprodutivo foi aparente durante a primavera. A intensificação da reprodução durante a primavera com a ocorrência de juvenis no verão, parece estar relacionada ao aumento da oferta de alimento durante a estação chuvosa e intrusões da Água Central do Atlântico Sul

O microfitoplâncton das águas costeiras do litoral Fluminense (estado do Rio de Janeiro): lista de especies e aspectos ecológicos

O microfitoplâncton das águas costeiras entre Cabo Frio e Rio de Janeiro foi coletado durante as operações PLATAFORMA IV, V e VI do AvPqOc SO OLIVEIRA (DGN) nos meses de outubro de 1984 e janeiro e março de 1985, As variações qualitativas e quantitativas foram analisadas em função das condições hidrológicas por meio de um tratamento estatístico multivariado dos dados. O fenômeno de ressurgência, responsável seja pelo afloramento da Água Central do Atlântico Sul, seja pela formação de uma termo-clina na camada eufótica, é o fator de terminante do crescimento algal que começa com especies de pequeno porte (Skeletonema costatum, Nitzschia spp) e evolui para uma maior diversidade com especies dos gêneros Guinardia, Rhizosolenia, Chaetoceros, Thalassiothrix. Em condição de estratificação da coluna d'agua notou-se a influência das aguas da Baía de Guanabara, com forte crescimento de Skeletonema costatum, e uma grande quantidade de detritos associados a algas cianofíceas e formas nanoplanctônicas.Phytoplankton of the coastal water between Cabo Frio and Rio de Janeiro were studied at the upwelling season (October, January and Maroh). Qualitative and quantitative variations are analized in function of the hydrological conditions by means of a multivariate statistical treatment of data. Cabo Frio upwelling is responsible for occurrence of a thermocline in the euphotic layer which induces phytoplankton growth, beginning by small-sized species (Nitzschia spp, Skeletonema costatum) and evoluting to highest diversity and quantity of different microphytoplanktonic forms (Guinardia, Rhizosolenia, Chaetoceros, Thalassiothrix). When water column is sharply stratified, we observe Guanabara Bay influence, with high growth of Skeletonema costatum and high quantity of detritus together with blue-green algae and nanoplanktonic forms

A diversidade específica para a análise das sucessões fitoplanctônicas. Aplicação ao ecossistema da ressurgência de Cabo Frio (RJ).

Extensive qualitative and quantitative data on phytoplankton collected in the Cabo Frio (Brazil) upwelling zone and analysed by Utermohl method were used for calculating Gleason-Margalef, Menhinick, Shannon, Margalef, Simpson inverse and Mac Intosh absolute diversity indices, and the relative indices of Redundancy and Evenness. The relationships between Margalef index and the other indices were studied. Shannon index, mathematically similar to the Margalef index showed the best agreement (r = 0,959); Gleason index is simpler to calculate and is quite satisfactory for a superficial analysis (r = 0,880). The Redundancy calculation is recommended for the interpretation of a single sample. In general, at Cabo Frio, phytoplankton diversity index is rarely less than 1.00 bit.cel“1 even after the enrichment by deep water. The planktonic ecosystem in Cabo Frio maintains a certain level of maturity which may explain the relatively mild nature of the blooms which follow upwelling.A partir de dados quantitativos e qualitativos sobre o fitoplâncton da ressurgência de Cabo Frio (RJ) foram calculados os índices absolutos de diversidade específica de Gleason-Margalef, Menhinick, Shannon, Margalef, inverso de Simpson, Mac Intosh e os índices relativos de Redundância e Uniformidade. Foi realizado um estudo de correlações entre o índice de Margalef e os demais. O índice de Shannon apresentou a melhor correlação (r = 0,959) e o de Gleason, de cálculo bem simples, pode ser considerado satisfatório para uma análise superficial (r = 0,880). O cálculo da Redundância é aconselhado para a análise de uma amostra isolada. Nas águas costeiras de Cabo Frio, o índice de diversidade específica do fitoplâncton é raramente inferior a 1,00 bit.cel'1, mesmo após a fertilização pelas águas profundas. O ecossistema planctônico de Cabo Frio mantém um certo nível de maturidade que pode explicar a fraca intensidade dos florescimentos fitoplanctônicos consecutivos aos efeitos da ressurgência

Scaling of Crack Surfaces and Implications on Fracture Mechanics

The scaling laws describing the roughness development of crack surfaces are incorporated into the Griffith criterion. We show that, in the case of a Family-Vicsek scaling, the energy balance leads to a purely elastic brittle behavior. On the contrary, it appears that an anomalous scaling reflects a R-curve behavior associated to a size effect of the critical resistance to crack growth in agreement with the fracture process of heterogeneous brittle materials exhibiting a microcracking damage.Comment: Revtex, 4 pages, 3 figures, accepted for publication in Physical Review Letter

Microbeam Radiation Therapy controls local growth of radioresistant melanoma and treats out-of-field locoregional metastasis.

PURPOSE Synchrotron-generated microbeam radiotherapy (MRT) represents an innovative preclinical type of cancer radiotherapy with an excellent therapeutic ratio. Beyond local control, metastatic spread is another important endpoint to assess the effectiveness of radiotherapy treatment. Currently, no data exists on an association between MRT and metastasis. Here, we evaluated the ability of MRT to delay B16F10 murine melanoma progression and locoregional metastatic spread. METHODS AND MATERIALS We assessed the primary tumor response and the extent of metastasis in sentinel lymph nodes in two cohorts of C57BL/6J mice, one receiving a single MRT and another receiving two MRT delivered with a 10-day interval. We compared these two cohorts with synchrotron broad beam-irradiated and non-irradiated mice. In addition, using multi-plex quantitative platforms, we measured plasma concentrations of 34 pro- and anti-inflammatory cytokines and frequencies of immune cell subsets infiltrating primary tumors that received either one or two MRT treatments. RESULTS Two MRT treatments were significantly more effective for local control than single MRT. Remarkably, the second MRT also triggered a pronounced regression of out-of-radiation field locoregional metastasis. Augmentation of CXCL5, CXCL12 and CCL22 levels after the second MRT indicated that inhibition of melanoma progression could be associated with increased activity of anti-tumor neutrophils and T-cells. Indeed, we demonstrated elevated infiltration of neutrophils and activated T-cells in the tumors following the second MRT. CONCLUSIONS Our study highlights the importance of monitoring metastasis following MRT and provides the first MRT fractionation schedule that promotes local and locoregional control with the potential to manage distant metastasis

Accurate quantification of atherosclerotic plaque volume by 3D vascular ultrasound using the volumetric linear array method.

Direct quantification of atherosclerotic plaque volume by three-dimensional vascular ultrasound (3DVUS) is more reproducible than 2DUS-based three-dimensional (2D/3D) techniques that generate pseudo-3D volumes from summed 2D plaque areas; however, its accuracy has not been reported. We aimed to determine 3DVUS accuracy for plaque volume measurement with special emphasis on small plaques (a hallmark of early atherosclerosis). The in vitro study consisted of nine phantoms of different volumes (small and medium-large) embedded at variable distances from the surface (superficial vs. >5 cm-depth) and comparison of 3DVUS data generated using a novel volumetric-linear array method with the real phantom volumes. The in vivo study was undertaken in a rabbit model of atherosclerosis in which 3DVUS and 2D/3D volume measurements were correlated against gold-standard histological measurements. In the in vitro setting, there was a strong correlation between 3DVUS measures and real phantom volume both for small (3.0-64.5 mm(3) size) and medium-large (91.1-965.5 mm(3) size) phantoms embedded superficially, with intraclass correlation coefficients (ICC) of 0.99 and 0.98, respectively; conversely, when phantoms were placed at >5 cm, the correlation was only moderate (ICC = 0.67). In the in vivo setting there was strong correlation between 3DVUS-measured plaque volumes and the histological gold-standard (ICC = 0.99 [4.02-92.5 mm(3) size]). Conversely, the correlation between 2D/3D values and the histological gold standard (sum of plaque areas) was weaker (ICC = 0.87 [49-520 mm(2) size]), with large dispersion of the differences between measurements in Bland-Altman plots (mean error, 79.2 mm(2)). 3DVUS using the volumetric-linear array method accurately measures plaque volumes, including those of small plaques. Measurements are more accurate for superficial arterial territories than for deep territories.S

LEMUR: Large European Module for solar Ultraviolet Research. European contribution to JAXA's Solar-C mission

Understanding the solar outer atmosphere requires concerted, simultaneous solar observations from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at high spatial resolution (between 0.1" and 0.3"), at high temporal resolution (on the order of 10 s, i.e., the time scale of chromospheric dynamics), with a wide temperature coverage (0.01 MK to 20 MK, from the chromosphere to the flaring corona), and the capability of measuring magnetic fields through spectropolarimetry at visible and near-infrared wavelengths. Simultaneous spectroscopic measurements sampling the entire temperature range are particularly important. These requirements are fulfilled by the Japanese Solar-C mission (Plan B), composed of a spacecraft in a geosynchronous orbit with a payload providing a significant improvement of imaging and spectropolarimetric capabilities in the UV, visible, and near-infrared with respect to what is available today and foreseen in the near future. The Large European Module for solar Ultraviolet Research (LEMUR), described in this paper, is a large VUV telescope feeding a scientific payload of high-resolution imaging spectrographs and cameras. LEMUR consists of two major components: a VUV solar telescope with a 30 cm diameter mirror and a focal length of 3.6 m, and a focal-plane package composed of VUV spectrometers covering six carefully chosen wavelength ranges between 17 and 127 nm. The LEMUR slit covers 280" on the Sun with 0.14" per pixel sampling. In addition, LEMUR is capable of measuring mass flows velocities (line shifts) down to 2 km/s or better. LEMUR has been proposed to ESA as the European contribution to the Solar C mission.Comment: 35 pages, 14 figures. To appear on Experimental Astronom

Environmental and sanitary conditions of guanabara bay, Rio de Janeiro

Guanabara Bay is the second largest bay in the coast of Brazil, with an area of 384 km2. In its surroundings live circa 16 million inhabitants, out of which 6 million live in Rio de Janeiro city, one of the largest cities of the country, and the host of the 2016 Olympic Games. Anthropogenic interference in Guanabara Bay area started early in the XVI century, but environmental impacts escalated from 1930, when this region underwent an industrialization process. Herein we present an overview of the current environmental and sanitary conditions of Guanabara Bay, a consequence of all these decades of impacts. We will focus on microbial communities, how they may affect higher trophic levels of the aquatic community and also human health. The anthropogenic impacts in the bay are flagged by heavy eutrophication and by the emergence of pathogenic microorganisms that are either carried by domestic and/or hospital waste (e.g., virus, KPC-producing bacteria, and fecal coliforms), or that proliferate in such conditions (e.g., vibrios). Antibiotic resistance genes are commonly found in metagenomes of Guanabara Bay planktonic microorganisms. Furthermore, eutrophication results in recurrent algal blooms, with signs of a shift toward flagellated, mixotrophic groups, including several potentially harmful species. A recent large-scale fish kill episode, and a long trend decrease in fish stocks also reflects the bay’s degraded water quality. Although pollution of Guanabara Bay is not a recent problem, the hosting of the 2016 Olympic Games propelled the government to launch a series of plans to restore the bay’s water quality. If all plans are fully implemented, the restoration of Guanabara Bay and its shores may be one of the best legacies of the Olympic Games in Rio de Janeiro