Radio Sources in Galaxy Clusters at 28.5 GHz

We present serendipitous detections of radio sources at 28.5 GHz (1 cm), which resulted from our program to image thermal Sunyaev-Zeldovich (SZ) effect in 56 galaxy clusters. We find 64 radio sources with fluxes down to 0.4 mJy, and within 250 arcseconds from the pointing centers. The spectral indices (S ~ \nu^-\alpha) of 54 sources with published low frequency flux densities range from -0.6 to 2 with a mean of 0.77, and a median of 0.84. Extending low frequency surveys of radio sources towards galaxy clusters CL 0016+16, Abell 665, and Abell 2218 to 28.5 GHz, and selecting sources with 1.4 GHz flux density greater than 7 mJy to form an unbiased sample, we find a mean spectral index of 0.71 and a median of 0.71. We find 4 to 7 times more sources predicted from a low frequency survey in areas without galaxy clusters. This excess cannot be accounted for by gravitational lensing of a background radio population by cluster potentials, indicating most of the detected sources are associated with galaxy clusters. For the cluster Abell 2218, the presence of unsubtracted radio sources with 28.5 GHz flux densities less than 0.5 mJy, can only contribute to temperature fluctuations at a level of 10 to 25 \muK. The corresponding error due to radio point source contamination in the Hubble constant derived through a combined analysis of 28.5 GHz SZ images and X-ray emission observations ranges from 1% to 6%.Comment: 18 pages, 8 figures, to appear in April 1998 issue of A

Índices agrometeorológicos aplicados com imagens MODIS e dados climáticos no Estado e Minas Gerais.

Minas Gerais state, Brazil, has experienced severe water scarcity in some areas, demanding largescale water balance studies to subsidize water policies. The reflectance bands from the MOD13Q1 MODIS product were used together with agrometeorological data to acquire water balance indices in the state, during the years from 2012 to 2015, later extracting the main agricultural growing regions, North, Northwest and Minas Triangle. Precipitation (Prec) and reference evapotranspiration (ET0) data from 36 weather stations were interpolated, while for the actual evapotranspiration (ET), the SAFER algorithm was used. A climatic water balance indicator was applied, the Water Balance Difference (WBd = Prec - ET) and, for the surface moisture, the evapotranspiration ratio (ETr = ET/ET0) was used. Higher WBd happened from the middle of October to the end of December, while the largest ETr values were between March and May.. According to the ETr values, the soil moisture storage showed a gap in relation to the WBd index, because the lapse time the soil to recover its retention capacity. Considering all studied years, ET attended the atmospheric demand by 50, 53 and 61% in the agricultural growing regions of North, Northwest and Minas Triangle. It was demonstrated the potential to monitor the water conditions for the 16-day periods on a large scale by combining weather measurements and MODIS products

Interpolação de dados agrometeorológicos em duas densidades amostrais no norte de Minas Gerais.

As obtenções de dados meteorológicos de estações agrometeorológicas muitas vezes são em número reduzido e dificultam o estudo de variabilidade espacial. O objetivo deste trabalho foi verificar a variabilidade espacial utilizando duas densidades de pontos amostrais, uma com cinco pontos relativos às estações do INMET (Instituto Nacional de Meteorologia) e outra quando acrescidos 11 pontos das estações instaladas pela Embrapa totalizando 16 estações na região norte do Estado de Minas Gerais. Os dados meteorológicos mensais utilizados, para a interpolação nas duas densidades amostrais de cinco pontos (estações do INMET) e de 16 pontos (esta- ções do INMET e da Embrapa) para os anos de 2013 e 2014, foram: a radiação solar global incidente (RG), a temperatura do ar (Ta ) e a evapotranspiração de referência (ET0 ). Foram realizadas a estatística descritiva e análise geoestatística. A densidade amostral com cinco pontos das estações do INMET foi insuficiente para análise de variabilidade espacial e o incremento na densidade amostral decorrente das 11 estações da Embrapa permitiu um ganho na representação espacial dos dados meteorológicos usados para obtenção da evapotranspiração, gerando mapas de krigagem com contornos melhor definidos e em maior número, contribuindo, portanto, com o monitoramento dos agros-ecossistemas nos municípios do norte de Minas Gerais

Evapotranspiração em áreas irrigadas utilizando imagens Rapid Eye.

Com a finalidade de analisar a dinâmica da evapotranspiração (ET) nas áreas de pivôs centrais no município de Unaí/MG, na Bacia do Rio Paracatu, foi aplicado o modelo SAFER (Simple Algorithm For Evapotranspiration Retrieving). Parâmetros biofísicos como albedo da superfície, NDVI (Normalized Difference Vegetation Index), saldo de radiação, temperatura da superfície e produtividade da água, são obtidos através de imagens de satélite e com dados meteorológicos é obtida a evapotranspiração de referência (ET0). Foram obtidas imagens do satélite RapidEye (resolução de 5m) de 2011 e 2012 (setembro) e 2013 e 2014 (maio) e a máscara de pivôs centrais disponibilizada pela Embrapa Milho e Sorgo. A evapotranspiração (ET) média diária de toda em setembro de 2011 foi 0,39 ± 1,04 mm e valor máximo de 7,5 mm. Nas áreas com pivôs centrais, a ET média foi de 0,69 ± 1,44 mm. Na imagem de 2012, a ET foi de 0,33 ±0,91, alcançando 7,44 mm e nas áreas irrigadas 0,37 ± 1,01 mm. Nas imagens de maio de 2013 e 2014, a ET média em áreas de pivôs centrais foi de 2,43 ± 2,27 e 2,63 ± 2,11, respectivamente. Em 2010, constatou-se que vários pivôs estavam fora de operação. Ressalta-se que a dinâmica da ET depende do calendário agrícola, ficando somente solo exposto em períodos de colheita e preparo do solo, diminuindo a transferência de água para a atmosfera. Com os resultados obtidos através de imagens de alta resolução espacial, sem a banda termal, foi possível obter a evapotranspiração em nível de pivô central, auxiliando o uso racional da água em tempos de deficiência hídrica

Measuring and Understanding the Universe

Revolutionary advances in both theory and technology have launched cosmology into its most exciting period of discovery yet. Unanticipated components of the universe have been identified, promising ideas for understanding the basic features of the universe are being tested, and deep connections between physics on the smallest scales and on the largest scales are being revealed.Comment: 39 pages, 11 figures, 1 table, accepted for publication in Reviews of Modern Physics Colloqui

Sunyaev-Zel'dovich Effect Observations of the Bullet Cluster (1E 0657-56) with APEX-SZ

We present observations of the Sunyaev-Zel'dovich effect (SZE) in the Bullet cluster (1E 0657--56) using the APEX-SZ instrument at 150 GHz with a resolution of 1 arcmin. The main results are maps of the SZE in this massive, merging galaxy cluster. The cluster is detected with 23 sigma significance within the central 1 arcmin radius of the source position. The SZE map has a broadly similar morphology to that in existing X-ray maps of this system, and we find no evidence for significant contamination of the SZE emission by radio or IR sources. In order to make simple quantitative comparisons with cluster gas models derived from X-ray observations, we fit our data to an isothermal elliptical beta model, despite the inadequacy of such a model for this complex merging system. With an X-ray derived prior on the power-law index, beta = 1.04 +0.16 -0.10, we find a core radius r_c =142 +/- 18 arcsec, an axial ratio of 0.889 +/- 0.072, and a central temperature decrement of -771 +/- 71 micro-K_CMB, including a +/-5.5% flux calibration uncertainty. Combining the APEX-SZ map with a map of projected electron surface density from Chandra X-ray observations, we determine the mass-weighted temperature of the cluster gas to be T_mg=10.8 +/- 0.9 keV, significantly lower than some previously reported X-ray spectroscopic temperatures. Under the assumption of an isothermal cluster gas distribution in hydrostatic equilibrium, we compute the gas mass fraction for prolate and oblate spheroidal geometries and find it to be consistent with previous results from X-ray and weak lensing observations. This work is the first result from the APEX-SZ experiment, and represents the first reported scientific result from observations with a large array of multiplexed superconducting transition-edge sensor bolometers.Comment: 17 pages, 5 figures, accepted for publication in the Astrophysical Journal. Changes in v2: Modified in response to referee comments. Also, improvements in the analysis pipeline and flux calibration result in modification of the maps and model fit parameters. Calibration section and X-ray comparison sections are significantly modifie

Palaeogenomic analysis of black rat (Rattus rattus) reveals multiple European introductions associated with human economic history

The distribution of the black rat (Rattus rattus) has been heavily influenced by its association with humans. The dispersal history of this non-native commensal rodent across Europe, however, remains poorly understood, and different introductions may have occurred during the Roman and medieval periods. Here, in order to reconstruct the population history of European black rats, we generated a de novo genome assembly of the black rat, 67 ancient black rat mitogenomes and 36 ancient nuclear genomes from sites spanning the 1st-17th centuries CE in Europe and North Africa. Analyses of mitochondrial DNA confirm that black rats were introduced into the Mediterranean and Europe from Southwest Asia. Genomic analyses of the ancient rats reveal a population turnover in temperate Europe between the 6th and 10th centuries CE, coincident with an archaeologically attested decline in the black rat population. The near disappearance and re-emergence of black rats in Europe may have been the result of the breakdown of the Roman Empire, the First Plague Pandemic, and/or post-Roman climatic cooling.Competing Interest StatementThe authors have declared no competing interest.- Results and Discussion -- The demographic history of Rattus rattus and its closely related species -- A global phylogeography of the black rat based on mitochondrial DNA -- Ancient genomes reveal the relationships of European black rats over space and time - Discussion - Method

Nematodes as indicators of shrimp farm impact on an amazonian estuary (Curuçá, Pará, Brazil)

Abstract Shrimp farming reduces demand on wild fishery stocks and avoids environmental damage resulting from fishing practices, however, it has the potential to affect the water quality if not properly managed. In this study the impacts of a shrimp farm in an Amazonian estuary were evaluated, focusing on changes in nematodes regarding taxonomic composition, richness, density and diversity. Sampling was conducted in August 2004 (dry season) and January 2005 (rainy season) in the river at stations situated upstream and downstream at different distances from the main source of farm effluent discharge. Thirty-eight genera were recorded with Terschellingia dominating in the dry season and Terschellingia, Daptonema, Ptycholaimellus and Gomphionema in the rainy season. Abundances were within the range recorded in other estuaries and together with genera richness and diversity showed a strong temporal pattern with significantly higher values in the rainy season. No clear patterns of changes were observed at the stations. Some signs of organic enrichment were detected but they were not yet intense, probably a consequence of the strong local hydrodynamics and the age of the shrimp farm, which was just starting its operation. We recommend that in future studies on farming impacts a combination of factors, beyond the physical and chemical parameters of the water and sediments or taxonomic refinement, should be taken into account - such as the duration of the operation of the farm, the area occupied by ponds and the farm's production. Furthermore, we also believe that nematodes are a useful tool for evaluating aquaculture impacts due to the ease of sampling and because they are organisms at the base of marine food chain

Semantic Similarity for Automatic Classification of Chemical Compounds

With the increasing amount of data made available in the chemical field, there is a strong need for systems capable of comparing and classifying chemical compounds in an efficient and effective way. The best approaches existing today are based on the structure-activity relationship premise, which states that biological activity of a molecule is strongly related to its structural or physicochemical properties. This work presents a novel approach to the automatic classification of chemical compounds by integrating semantic similarity with existing structural comparison methods. Our approach was assessed based on the Matthews Correlation Coefficient for the prediction, and achieved values of 0.810 when used as a prediction of blood-brain barrier permeability, 0.694 for P-glycoprotein substrate, and 0.673 for estrogen receptor binding activity. These results expose a significant improvement over the currently existing methods, whose best performances were 0.628, 0.591, and 0.647 respectively. It was demonstrated that the integration of semantic similarity is a feasible and effective way to improve existing chemical compound classification systems. Among other possible uses, this tool helps the study of the evolution of metabolic pathways, the study of the correlation of metabolic networks with properties of those networks, or the improvement of ontologies that represent chemical information