Cent Purity Research Articles

SPT-SZ MCMF: an extension of the SPT-SZ catalogue over the DES region

ABSTRACT We present an extension to a Sunyaev–Zel’dovich Effect (SZE) selected cluster catalogue based on observations from the South Pole Telescope (SPT); this catalogue extends to lower signal to noise than the previous SPT–SZ catalogue and therefore includes lower mass clusters. Optically derived redshifts, centres, richnesses, and morphological parameters together with catalogue contamination and completeness statistics are extracted using the multicomponent matched filter (MCMF) algorithm applied to the S/N > 4 SPT–SZ candidate list and the Dark Energy Survey (DES) photometric galaxy catalogue. The main catalogue contains 811 sources above S/N = 4, has 91 per cent purity, and is 95 per cent complete with respect to the original SZE selection. It contains in total 50 per cent more clusters and twice as many clusters above z = 0.8 in comparison to the original SPT-SZ sample. The MCMF algorithm allows us to define subsamples of the desired purity with traceable impact on catalogue completeness. As an example, we provide two subsamples with S/N > 4.25 and S/N > 4.5 for which the sample contamination and cleaning-induced incompleteness are both as low as the expected Poisson noise for samples of their size. The subsample with S/N > 4.5 has 98 per cent purity and 96 per cent completeness and is part of our new combined SPT cluster and DES weak-lensing cosmological analysis. We measure the number of false detections in the SPT-SZ candidate list as function of S/N, finding that it follows that expected from assuming Gaussian noise, but with a lower amplitude compared to previous estimates from simulations.

Detection, instance segmentation, and classification for astronomical surveys with deep learning (deepdisc): detectron2 implementation and demonstration with Hyper Suprime-Cam data

ABSTRACT The next generation of wide-field deep astronomical surveys will deliver unprecedented amounts of images through the 2020s and beyond. As both the sensitivity and depth of observations increase, more blended sources will be detected. This reality can lead to measurement biases that contaminate key astronomical inferences. We implement new deep learning models available through Facebook AI Research’s detectron2 repository to perform the simultaneous tasks of object identification, deblending, and classification on large multiband co-adds from the Hyper Suprime-Cam (HSC). We use existing detection/deblending codes and classification methods to train a suite of deep neural networks, including state-of-the-art transformers. Once trained, we find that transformers outperform traditional convolutional neural networks and are more robust to different contrast scalings. Transformers are able to detect and deblend objects closely matching the ground truth, achieving a median bounding box Intersection over Union of 0.99. Using high-quality class labels from the Hubble Space Telescope, we find that when classifying objects as either stars or galaxies, the best-performing networks can classify galaxies with near 100 per cent completeness and purity across the whole test sample and classify stars above 60 per cent completeness and 80 per cent purity out to HSC i-band magnitudes of 25 mag. This framework can be extended to other upcoming deep surveys such as the Legacy Survey of Space and Time and those with the Roman Space Telescope to enable fast source detection and measurement. Our code, deepdisc, is publicly available at https://github.com/grantmerz/deepdisc.

RASS-MCMF: a full-sky X-ray selected galaxy cluster catalogue

ABSTRACT We present the RASS-MCMF catalogue of 8449 X-ray selected galaxy clusters over 25 000 deg2 of extragalactic sky. The accumulation of deep multiband optical imaging data, the development of the Multi-Component Matched Filter (MCMF) cluster confirmation algorithm, and the release of the DESI Legacy Survey DR10 catalogue makes it possible – for the first time, more than 30 yr after the launch of the ROSAT X-ray satellite – to identify the majority of the galaxy clusters detected in the second ROSAT All-Sky-Survey (RASS) source catalogue (2RXS). The resulting 90 per cent pure RASS-MCMF catalogue is the largest intracluster medium (ICM)-selected cluster sample to date. RASS-MCMF probes a large dynamic range in cluster mass spanning from galaxy groups to the most massive clusters. The cluster redshift distribution peaks at $z$ ∼ 0.1 and extends to redshifts $z$ ∼ 1. Out to $z$ ∼ 0.4, the RASS-MCMF sample contains more clusters per redshift interval (dN/dz) than any other ICM-selected sample. In addition to the main sample, we present two subsamples with 6912 and 5506 clusters, exhibiting 95 per cent and 99 per cent purity, respectively. We forecast the utility of the sample for a cluster cosmological study, using realistic mock catalogues that incorporate most observational effects, including the X-ray exposure time and background variations, the existence likelihood selection and the impact of the optical cleaning with the algorithm MCMF. Using realistic priors on the observable–mass relation parameters from a DES-based weak lensing analysis, we estimate the constraining power of the RASS-MCMF×DES sample to be of 0.026, 0.033, and 0.15 (1σ) on the parameters Ωm, σ8, and $w$, respectively.

The VVV near-IR galaxy catalogue in a Northern part of the Galactic disc

ABSTRACT The automated identification of extragalactic objects in large surveys provides reliable and reproducible samples of galaxies in less time than procedures involving human interaction. However, regions near the Galactic disc are more challenging due to the dust extinction. We present the methodology for the automatic classification of galaxies and non-galaxies at low Galactic latitude regions using both images and photometric and morphological near-IR data from the VISTA Variables in the Vía Láctea eXtended (VVVX) survey. Using the VVV NIR Galaxy Catalogue (VVV NIRGC), we analyse by statistical methods the most relevant features for galaxy identification. This catalogue was used to train a convolutional neural network with image data and an XGBoost model with both photometric and morphological data and then to generate a data set of extragalactic candidates. This allows us to derive probability catalogues used to analyse the completeness and purity as a function of the configuration parameters and to explore the best combinations of the models. As a test case, we apply this methodology to the Northern disc region of the VVVX survey, obtaining 172 396 extragalactic candidates with probabilities of being galaxies. We analyse the performance of our methodology in the VVV disc, reaching an F1-score of 0.67, a 65 per cent purity, and a 69 per cent completeness. We present the VVV NIRGC: Northern part of the Galactic disc comprising 1003 new galaxies, with probabilities greater than 0.6 for either model, with visual inspection and with only two previously identified galaxies. In the future, we intend to apply this methodology to other areas of the VVVX survey.

Finding protoclusters to trace galaxy evolution – I. The finder and its performance

ABSTRACT We develop a method to identify protoclusters based on dark matter haloes represented by galaxy groups selected from surveys of galaxies at high redshift. We test the performance of this method on haloes in N-body simulations, and find that it can correctly identify more than 85 per cent of the true protoclusters with $\gtrsim 95$ per cent purity and with mass estimates typically within 0.25 dex from their true values. We show how the information provided by the protoclusters can be used to link galaxies in present-day clusters of galaxies with their high-redshift progenitors. Our tests show that the protoclusters identified by our method can recover reliably the progenitor stellar mass distribution of galaxies, thereby providing an avenue to investigate the formation and evolution of present-day galaxy clusters and their member galaxies.

Classifying stars, galaxies, and AGNs in CLAUDS + HSC-SSP using gradient boosted decision trees

ABSTRACT Classifying catalogue objects as stars, galaxies, or active galactic nuclei (AGNs) is a crucial part of any statistical study of galaxies. We describe our pipeline for binary (star/galaxy) and multiclass (star/galaxy/Type I AGN/Type II AGN) classification developed for the very deep CLAUDS + HSC-SSP u*grizy data set. Our method uses the XGBoost implementation of gradient boosted trees (GBTs) to train ensembles of models that take photometry, colours, maximum surface brightnesses, and effective radii from all available bands as input, and output the probability that an object belongs to each of the classes under consideration. At iAB < 25 our binary star/galaxy model has AUC = 0.9974 and at the threshold that maximizes our sample’s weighted F1 score, selects a sample of galaxies with 99.7 per cent purity and 99.8 per cent completeness. We test the model’s ability to generalize to objects fainter than those seen during training and find that extrapolation of ∼1−2 mag is reasonable for most applications provided that the galaxies in the training sample are representative of the range of redshifts and colours of the galaxies in the target sample. We also perform an exploratory analysis of the method’s ability to identify AGNs using a small X-ray-selected sample and find that it holds promise for classifying Type I AGN, although it performs less well for Type II AGN. Our results demonstrate that GBTs provide a flexible, robust, and efficient method for performing classification of catalogue objects in large astronomical imaging surveys.

INCREASE IN PERCENT PURITY OF β CAROTENE CONTENT IN ORGANICALLY CULTIVATED TOMATOES ESTIMATED BY SPE AND HPLC

ABSTRACT Nutrition and health are the two most important related areas which always need to be refreshed. Tomato has become an important vegetable of the world in view of the increasing demand for the fresh consumption as well as for processing industries. As a fresh commodity and as a processed product, tomato represents a major source of essential nutrients. The present studies were carried out to evaluate the beta-carotene content of organic and conventionally grown tomatoes by combining SPE and HPLC techniques. The analysis of the sample revealed that β-carotene percentage recorded in organic samples were higher than that the control. Sample T₃ organic was recorded with 13.41 per cent purity, followed by T₄ (8.3%). Minimum percentage purity (4.81%) was recorded in the conventional treatment (control). The results clearly indicated a higher percentage of β-carotene in organic treatments, as compared to farmer’s practice (control).

Department of Biotechnology, Shoolini University, Bhajol, Solan -(HP), India.

ABSTRACT Nutrition and health are the two most important related areas which always need to be refreshed. Tomato has become an important vegetable of the world in view of the increasing demand for the fresh consumption as well as for processing industries. As a fresh commodity and as a processed product, tomato represents a major source of essential nutrients. The present studies were carried out to evaluate the beta-carotene content of organic and conventionally grown tomatoes by combining SPE and HPLC techniques. The analysis of the sample revealed that β-carotene percentage recorded in organic samples were higher than that the control. Sample T₃ organic was recorded with 13.41 per cent purity, followed by T₄ (8.3%). Minimum percentage purity (4.81%) was recorded in the conventional treatment (control). The results clearly indicated a higher percentage of β-carotene in organic treatments, as compared to farmer’s practice (control).

Propellant Grade Hydrazine in Mono/Bi-propellant Thrusters: Preparation and Performance Evaluation

Propellant grade hydrazine was prepared with 64 per cent yield and 95.5 per cent purity. Purity of the propellant grade hydrazine was determined using wet chemical, gas chromatographic (GC) and eudiometric methods. It was observed that the compositions containing blends of hydrazine-methyl alcohol-ammonium nitrate and hydrazine-methyl alcohol-ammonium perchlorate were not found to be frozen even after cooling to -65 °C for 30 minutes. Mono and bi-propellant thrusters were designed and developed to demonstrate the performance of prepared propellant grade hydrazine as a promising rocket fuel. Five static tests with 22 N thruster and one static test with 1 N thruster were performed successfully in mono-propellant mode. The hurdles of chamber pressure oscillations were overcome by compact packing of the catalyst. The desired decomposition and chamber pressure were achieved. One static test was performed successfully with 60 N bi-propellant thruster. The desired chamber pressure and thrust were achieved. The combustion was smooth and C* achieved was higher than that of UH-25, N2O4 combination. The performance of prepared propellant grade hydrazine shows it as a promising rocket fuels.Defence Science Journal, Vol. 65, No. 1, January 2015, pp.31-38, DOI:http://dx.doi.org/10.14429/dsj.65.7986

Data mining for gravitationally lensed quasars

Gravitationally lensed quasars are brighter than their unlensed counterparts and produce images with distinctive morphological signatures. Past searches and target-selection algorithms, in particular the Sloan Quasar Lens Search (SQLS), have relied on basic morphological criteria, which were applied to samples of bright, spectroscopically confirmed quasars. The SQLS techniques are not sufficient for searching into new surveys (e.g. DES, PS1, LSST), because spectroscopic information is not readily available and the large data volume requires higher purity in target/candidate selection. We carry out a systematic exploration of machine-learning techniques and demonstrate that a two-step strategy can be highly effective. In the first step, we use catalogue-level information (griz+WISE magnitudes, second moments) to pre-select targets, using artificial neural networks. The accepted targets are then inspected with pixel-by-pixel pattern recognition algorithms (gradient-boosted trees), to form a final set of candidates. The results from this procedure can be used to further refine the simpler SQLS algorithms, with a twofold (or threefold) gain in purity and the same (or 80 per cent) completeness at target-selection stage, or a purity of 70 per cent and a completeness of 60 per cent after the candidate-selection step. Simpler photometric searches in griz+WISE based on colour cuts would provide samples with 7 per cent purity or less. Our technique is extremely fast, as a list of candidates can be obtained from a Stage III experiment (e.g. DES catalogue/data base) in a few CPU hours. The techniques are easily extendable to Stage IV experiments like LSST with the addition of time domain information.

Isolation and Characterization of Biologically Active Venom Protein from Sea Snake Enhydrina schistosa

The present study is designed to investigate the isolation and characterization of biological and biochemical active venom protein from sea snake, Enhydrina schistosa. The highest purification peaks in ion-exchange chromatography on DEAE-cellulose column were obtained for fraction numbers 39-49 when eluted with 0.35-0.45 M NaCl. Eighty per cent purity was obtained in the final stage of purification, and a single protein band of about 44 kDa was visualized in SDS-polyacrylamide gel under reducing condition. Purified venom protein expressed as haemolytic, cytotoxicity and proteolytic activities with lethal concentration (LC50 ) at 2.0 μg/mL. Venom protein exhibits enzymatic activity and hydrolyzed casein and gelatin. Gelatinolytic activity was optimal at pH 5-9. In conclusion, the present results suggested that the sea snake venom might be feasible sources for biologically active substances. Thus, this low molecular weight component of the venom protein could be used in potentially serve biological and pharmaceutical aspects.

A method for the tin pest presence testing in SnCu solder alloys

Purpose – The purpose of this study is to develop a testing method for tin pest in tin – copper (SnCu) alloys. Tin pest is the allotropic transformation of white β-tin (body-centered tetragonal structure) into gray α-tin (diamond cubic structure) at temperatures < 13.2°C. Design/methodology/approach – Bulk samples of Sn99Cu1 weight per cent (purity, 99.9 weight per cent) were cast in the form of roller-shaped ingots with a diameter of 1.0 cm and a height of 0.7 cm. The samples were then divided into four groups. The first group included samples artificially inoculated with α-tin powder. The second group was inoculated in the same way as the samples from the first group but additionally subjected to mechanical pressing. The third group of ingots was only subjected to mechanical pressing. The fourth group of samples consisted of as-received roller-shaped ingots.All samples were divided into two groups and kept either at −18°C or at −30°C for the low-temperature storage test. For tin pest identification, a visual inspection was made, using a Hirox digital microscope over 156 days at intervals not longer than 14 days. The plot of the transformation rate, presented as the average increase in the area of α-tin warts in time, was also determined. To demonstrate the differences between regions of β- and α-tin, scanning ion microscopy observations using the focused ion beam technique was performed. Findings – The first symptoms of tin pest were observed for the inoculated, mechanically pressed samples stored at −18°C, as well as those at −30°C, after less than 14 days. In the first stage of transformation, the rate was higher at −30°C for some time but, after about 75 days of storage at sub-zero temperatures, the rate at −30°C became lower compared to the rate at −18°C. Inoculation via the application of substances which are structurally similar to α-tin was efficient for the proposed new approach of rapid testing only when applied with simultaneous mechanical pressing. Infection from pressed-in seeds, leading to conventional seeded growth, was more rapid than infection in contact with seeds (without mechanical pressing), where the transition mechanism was induced by the epitaxial growth of metastable ice. Originality/value – The new rapid method for the diagnostic testing of the susceptibility of different SnCu alloys to tin pest in a period much shorter than 14 days (within single days for storage at −30°C) is proposed and described. The test procedure described in this paper produced results several times quicker than conventional procedures, which may take years. In effect, the behavior of tin alloys in the face of tin pest may be predicted much more easily and much earlier. The same procedure can be applied to other SnCu alloys used in electronics (and in other areas), if the test samples are prepared in a similar manner.

Culture of Fetal Erythroid Progenitor Cells From Maternal Blood for Non-Invasive Prenatal Genetic Diagnosis

Fetal committed erythroid progenitors CFU-E and M-BFU-E released into the maternal circulation during pregnancy are ideal candidates for in vitro proliferation since their lifespan is short and they can form colonies of 100-1000 cells in a semi-solid medium. In order to propagate these cells with a high rate of purity, a strategy was devised based on their prior enrichment with biotin-labelled human erythropoietin ligand and magnetic sorting before culturing in a suitable medium. Eight euploid pregnancies investigated in order to address this issue produced fetal clones in cultures with 18 per cent purity as assessed by polymerase chain reaction (PCR) analysis for Y-specific sequences, immunocytochemical staining for fetal gamma-globin, and fluorescence in situ hybridization (FISH) study. The CFU-E-type colony was the most represented progenitor, followed by M-BFU-E, and only occasionally was the detection of CFU-GEMM recorded. The retrospective diagnosis of two cases of fetal Down's syndrome by culturing fetal cells from maternal blood was accomplished for the first time. FISH analysis disclosed a strong presence of fetal trisomic cells (70 per cent and 40 per cent in the two cases). This strong presence would suggest a preferential leakage into maternal blood. The overall results of this study demonstrate that fetal cells can be cultured in vitro with reliable reproducibility, thus making the prospect of a non-invasive prenatal genetic diagnosis realistic.

Thermodynamic properties of 1-trimethylsilyl-1-propyne fromT=8 K toT=330 K

In an adiabatic vacuum calorimeter the temperature dependence of the standard molar heat capacityCp,m° of 1-trimethylsilyl-1-propyne (total mole fraction of impuritiesx=0.0315) has been studied at temperatures between 8 K and 330 K, to within 0.2 per cent. The temperature and enthalpy of melting of the compound have been measured. The experimental data were used to calculate the thermodynamic characteristics of melting of 1-trimethylsilyl-1-propyne of 100 per cent purity:Tfus°=204.42 K, ΔfusHm°/R=1318±6, ΔfusSm°/R=6.45±0.03 (whereRis the universal gas constant) and the thermodynamic functions in the range 0 K to 330 K, forT=298.15 K andp=101.325 kPa,Cp,m°/R=26.76, Δ0THm°/R·K=6023, Δ0TSm°/R=37.04, and Φm°/R=16.84. The isochoric heat capacityCV,mand its components, latticeCV,lat,mand atomicCV,at,m, have been estimated in the rangeT→0 toTfus°. The first (A) and the second (B) cryoscopic constants have been determined.

Culture of fetal erythroid progenitor cells from maternal blood for non-invasive prenatal genetic diagnosis.

Fetal committed erythroid progenitors CFU-E and M-BFU-E released into the maternal circulation during pregnancy are ideal candidates for in vitro proliferation since their lifespan is short and they can form colonies of 100-1000 cells in a semi-solid medium. In order to propagate these cells with a high rate of purity, a strategy was devised based on their prior enrichment with biotin-labelled human erythropoietin ligand and magnetic sorting before culturing in a suitable medium. Eight euploid pregnancies investigated in order to address this issue produced fetal clones in cultures with 18 per cent purity as assessed by polymerase chain reaction (PCR) analysis for Y-specific sequences, immunocytochemical staining for fetal gamma-globin, and fluorescence in situ hybridization (FISH) study. The CFU-E-type colony was the most represented progenitor, followed by M-BFU-E, and only occasionally was the detection of CFU-GEMM recorded. The retrospective diagnosis of two cases of fetal Down's syndrome by culturing fetal cells from maternal blood was accomplished for the first time. FISH analysis disclosed a strong presence of fetal trisomic cells (70 per cent and 40 per cent in the two cases). This strong presence would suggest a preferential leakage into maternal blood. The overall results of this study demonstrate that fetal cells can be cultured in vitro with reliable reproducibility, thus making the prospect of a non-invasive prenatal genetic diagnosis realistic.

Ultrastructural changes and immunocytochemical analysis of human placental trophoblast during short-term culture.

Trophoblastic cells, of at least 95 per cent purity by immunofluorescence and morphological criteria, were obtained from human term placenta by a simple trypsinisation method without the additional purification steps or complex culture conditions used by others. The differentiation of these cells was followed over four days in culture by fluorescence immunocytochemistry, by scanning and transmission electron microscopy and by light microscopy. The results support the idea that the isolated cells are cytotrophoblast and that these differentiate during this time into cells with characteristics of villous syncytiotrophoblast. This process involved first the formation of a multicellular layer of mononucleated cells, then the development of a syncytium of multinucleated cells and, not necessarily concurrently, functional differentiation. This may be a useful model for the study of syncytiotrophoblast function.

Rapid, single-step isolation of equine neutrophils on a discontinuous Percoll density gradient

A rapid single-step procedure for isolation of equine neutrophils (PMNS) from peripheral blood is described. A discontinuous gradient of two Percoll solutions (densities of 1.087 kg litre-1 and 1.108 kg litre-1 was used. The PMNS were isolated to more than 95 per cent purity with a viability of more than 99 per cent and a cell recovery of more than 83 per cent. The method used was rapid and reproducible and the equipment required is relatively simple. The function of the recovered cells was assessed in a chemotactic assay using a modified Boyden chamber technique.

Enthalpy of combustion of purine

The enthalpy of combustion of a commercial purine sample of 99.8 moles per cent purity was measured in an aneroid adiabatic bomb calorimeter. The molar enthalpy of combustion at 298.15 K for the reaction: C 5H 4N 4(cr)+6O 2(g)=5CO 2(g)+2H 2O(1)+2N 2(g) is Δ c H m o = −(2708.62±2.31) kJ·mol −1 ( p o = 101.325 kPa). The corresponding molar enthalpy of formation of purine, C 5H 4N 4, is Δ f H m o = (169.41±2.65) kJ·mol −1. The estimation of Δ f H m o for purine by three calculated paths yielded 180.15 kJ·mol −1. Some reasons for the difference are proposed.

Enthalpy of combustion of adenine

The enthalpy of combustion for a commercial adenine sample of 99.9 moles per cent purity was measured in an aneroid adiabatic bomb calorimeter. The molar enthalpy of combustion at 298.15 K for the reaction: C 5 H 5 N 5( c)+6.25 O 2( g) = 5 CO 2(g)+2.5 H 2 O(1)+2.5 N 2( g), was Δ c H m o = −(2779.02 ± 1.26) kJ · mol −1. The corresponding molar enthalpy of formation for adenine, C 5H 5N 5, was calculated to be Δ f H m o = (96.90 ± 1.29) kJ · mol −1. The present results were found to be in good agreement with those of the earlier work of Stiehler and Huffman.

Xenobiotic metabolism by alveolar type II cells isolated from rabbit lung

A procedure for the isolation of alveolar type II cells from rabbit lung was developed. Following pulmonary lavage to minimize macrophage contamination, viable cells (30% type II cells) were released by digestion with 0.1% Protease type I (Sigma) in 4-(2-hydroxyethyl)-1-piperazine-ethanesulphonic acid (HEPES)-buffered balanced salt solution containing 0.5 mM ethyleneglycolbis (amino-ethylether) tetra-acetate (EGTA) instilled via the trachea. Type II cells were enriched to 50–60 per cent purity by centrifugal elutriation. Density gradient centrifugation in metrizamide was used to increase the purity of the type II cells from the elutriator fraction to 80 per cent. Whole, freshly isolated alveolar type II cells metabolized 7-ethoxycoumarin at a rate of 30 pmoles umbelliferone formed per mg protein/min. However, only traces of coumarin hydroxylase activity were detected which could be accounted for by 1–2% Clara cell contamination in the type II cell fraction. NADPH-cytochrome c (cyt c) reductase activity in the sonicated type II cell fraction was 44 nmoles cyt c reduced per mg protein/min compared to 25 for lung homogenate. Benzo[ a]pyrene hydroxylase and N, N-dimethylaniline N-oxidase activities were also demonstrated in the type II cell fraction to be 13 pmoles 3-OH benzo[ a]pyrene · (mg protein) −1 · min −1 and 0.8 nmole DMA N-oxide · (mg protein) −1 · min −1 respectively. Microsomes prepared from the isolated type II cell fraction contained 74 pmoles cytochrome P-450/mg protein and 90 pmoles cytochrome b 5/mg protein.