scholarly journals Photometric Variability of the mCP Star CS Vir: Evolution of the Rotation Period

2018 ◽  
Vol 35 ◽  
Author(s):  
D. Ozuyar ◽  
H. T. Sener ◽  
I. R. Stevens
Keyword(s):  
Time Scale ◽  
Rotation Period ◽  
Period Variation ◽  
Time Interval ◽  
Data Sets ◽  
Data Set ◽  
Photometric Variability ◽  
Minimization Methods ◽  
First Time ◽  
Combined Data

AbstractThe aim of this study is to accurately calculate the rotational period of CS Vir by using STEREO observations and investigate a possible period variation of the star with the help of all accessible data. The STEREO data that cover 5-yr time interval between 2007 and 2011 are analysed by means of the Lomb–Scargle and Phase Dispersion Minimization methods. In order to obtain a reliable rotation period and its error value, computational algorithms such as the Levenberg–Marquardt and Monte Carlo simulation algorithms are applied to the data sets. Thus, the rotation period of CS Vir is improved to be 9.29572(12) d by using the 5-yr of combined data set. Also, the light elements are calculated as HJDmax = 2454715.975(11) + 9d· 29572(12) × E + 9d· 78(1.13) × 10 − 8 × E2 by means of the extremum times derived from the STEREO light curves and archives. Moreover, with this study, a period variation is revealed for the first time, and it is found that the period has lengthened by 0.66(8) s y−1, equivalent to 66 s per century. Additionally, a time-scale for a possible spin-down is calculated around τSD ~ 106 yr. The differential rotation and magnetic braking are thought to be responsible of the mentioned rotational deceleration. It is deduced that the spin-down time-scale of the star is nearly three orders of magnitude shorter than its main-sequence lifetime (τMS ~ 109 yr). It is, in return, suggested that the process of increase in the period might be reversible.

scholarly journals Continuous cardiac output monitoring in humans by invasive and noninvasive peripheral blood pressure waveform analysis

2006 ◽  
Vol 101 (2) ◽  
pp. 598-608 ◽  
Author(s):  
Zhenwei Lu ◽  
Ramakrishna Mukkamala
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Peripheral Resistance ◽  
Waveform Analysis ◽  
Cardiac Output Monitoring ◽  
Time Interval ◽  
Data Sets ◽  
Data Set ◽  
Arterial Blood ◽  
Output Monitoring

We present an evaluation of a novel technique for continuous (i.e., automatic) monitoring of relative cardiac output (CO) changes by long time interval analysis of a peripheral arterial blood pressure (ABP) waveform in humans. We specifically tested the mathematical analysis technique based on existing invasive and noninvasive hemodynamic data sets. With the former data set, we compared the application of the technique to peripheral ABP waveforms obtained via radial artery catheterization with simultaneous thermodilution CO measurements in 15 intensive care unit patients in which CO was changing because of disease progression and therapy. With the latter data set, we compared the application of the technique to noninvasive peripheral ABP waveforms obtained via a finger-cuff photoplethysmography system with simultaneous Doppler ultrasound CO measurements made by an expert in 10 healthy subjects during pharmacological and postural interventions. We report an overall CO root-mean-squared normalized error of 15.3% with respect to the invasive hemodynamic data set and 15.1% with respect to the noninvasive hemodynamic data set. Moreover, the CO errors from the invasive and noninvasive hemodynamic data sets were only mildly correlated with mean ABP (ρ = 0.41, 0.37) and even less correlated with CO (ρ = −0.14, −0.17), heart rate (ρ = 0.04, 0.19), total peripheral resistance (ρ = 0.38, 0.10), CO changes (ρ = −0.26, −0.20), and absolute CO changes (ρ = 0.03, 0.38). With further development and successful prospective testing, the technique may potentially be employed for continuous hemodynamic monitoring in the acute setting such as critical care and emergency care.

Combining cross-crystal averaging and MRSAD to phase a 4354-amino-acid structure

2016 ◽  
Vol 72 (2) ◽  
pp. 182-191
Author(s):  
Jason Nicholas Busby ◽  
J. Shaun Lott ◽  
Santosh Panjikar
Keyword(s):  
Radiation Damage ◽  
Model Building ◽  
Data Sets ◽  
Low Resolution ◽  
Data Set ◽  
C Protein ◽  
Large Size ◽  
Anomalous Signal ◽  
Difference Fourier ◽  
Combined Data

The B and C proteins from the ABC toxin complex ofYersinia entomophagaform a large heterodimer that cleaves and encapsulates the C-terminal toxin domain of the C protein. Determining the structure of the complex formed by B and the N-terminal region of C was challenging owing to its large size, the non-isomorphism of different crystals and their sensitivity to radiation damage. A native data set was collected to 2.5 Å resolution and a non-isomorphous Ta6Br12-derivative data set was collected that showed strong anomalous signal at low resolution. The tantalum-cluster sites could be found, but the anomalous signal did not extend to a high enough resolution to allow model building. Selenomethionine (SeMet)-derivatized protein crystals were produced, but the high number (60) of SeMet sites and the sensitivity of the crystals to radiation damage made phasing using the SAD or MAD methods difficult. Multiple SeMet data sets were combined to provide 30-fold multiplicity, and the low-resolution phase information from the Ta6Br12data set was transferred to this combined data set by cross-crystal averaging. This allowed the Se atoms to be located in an anomalous difference Fourier map; they were then used inAuto-Rickshawfor multiple rounds of autobuilding and MRSAD.

scholarly journals THE INFLUENCE OF MAGNITUDES TYPES IN THE NONEXTENSIVITY APPLIED AT THE CIRCUM-PACIFIC SUBDUCTION ZONES

2018 ◽  
Vol 36 (4) ◽  
pp. 1
Author(s):  
Thaís Machado Scherrer ◽  
George Sand França ◽  
Raimundo Silva ◽  
Daniel Brito de Freitas ◽  
Carlos da Silva Vilar
Keyword(s):  
Solid Earth ◽  
Subduction Zone ◽  
Subduction Zones ◽  
Time Interval ◽  
Data Sets ◽  
Data Set ◽  
Different Types ◽  
Data Source ◽  
The Impact

ABSTRACT. Following our own previous work, we reanalyze the nonextensive behavior over the circum-Pacific subduction zones evaluating the impact of using different types of magnitudes in the results. We used the same data source and time interval of our previous work, the NEIC catalog in the years between 2001 and 2010. Even considering different data sets, the correlation between q and the subduction zone asperity is perceptible, but the values found for the nonextensive parameter in the considered data sets presents an expressive variation. The data set with surface magnitude exhibits the best adjustments.Keywords: Nonextensivity, Seismicity, Solid Earth, Earthquake.RESUMO. No mesmo caminho do nosso trabalho anterior, reanalisamos o comportamento não extensivo sobre as zonas de subducção do círcuo de fogo do Pacífico, avaliando o impacto do uso de diferentes tipos de magnitude nos resultados. Utilizamos o mesmo intervalo de dados e fonte de nosso trabalho anterior, do catálogo NEIC entre os anos 2001 e 2010. Mesmo considerando diferentes conjuntos de dados, a correlação entre q e a aspereza das zonas de subducção é perceptível, mas os valores encontrados para o parâmetro não extensivo no conjuntos de dados considerados apresentam uma variação expressiva. O conjunto de dados com magnitude de superfície exibe os melhores ajustes.Palavras-chave: Não extensividade, Sismicidade, Terra Sólida, Terremotos.

scholarly journals Two years of Ozone radio soundings over Cotonou as part of AMMA: overview

2009 ◽  
Vol 9 (3) ◽  
pp. 11221-11268 ◽  
Author(s):  
V. Thouret ◽  
M. Saunois ◽  
A. Minga ◽  
A. Mariscal ◽  
B. Sauvage ◽  
...  
Keyword(s):  
West Africa ◽  
Biomass Burning ◽  
Lower Stratosphere ◽  
Lower Troposphere ◽  
Data Sets ◽  
Wet Season ◽  
Data Set ◽  
In Situ Data ◽  
Multidisciplinary Analysis ◽  
First Time

Abstract. As part of the African Monsoon Multidisciplinary Analysis (AMMA) program, a total of 98 ozone vertical profiles over Cotonou, Benin, have been measured during a 26 month period (December 2004–January 2007). These regular measurements broadly document the seasonal and inter annual variability of ozone in both the troposphere and the lower stratosphere over West Africa for the first time. This data set is complementary to the MOZAIC observations made from Lagos between 0 and 12 km during the period 1998–2004. Both data sets highlight the unique way in which West Africa is impacted by two biomass burning seasons: in December–February (dry season) due to burning in the Sahelian band and in June–August (wet season) due to burning in southern Africa. High inter annual variabilities between Cotonou and Lagos data sets and within each data set are observed and are found to be a major characteristic of this region. In particular, the dry and wet seasons are discussed in order to set the data of the Special Observing Periods (SOPs) into a climatological context. Compared to other dry and wet seasons, the dry and wet season campaigns took place in rather high ozoneenvironments. During the sampled wet seasons, southern intrusions of biomass burning were particularly frequent with concentrations up to 120 ppbv of ozone in the lower troposphere. An insight into the ozone distribution in the upper troposphere and the lower stratosphere (up to 26 km) is given. The first tropospheric columns of ozone based on in-situ data in this region are assessed. They compare well with satellite products on seasonal and inter annual time-scales, provided that the layer below 850 Pa where the remote instrument is less sensitive to ozone, is removed.

scholarly journals Finding flares in Kepler data using machine-learning tools

2018 ◽  
Vol 616 ◽  
pp. A163 ◽  
Author(s):  
Krisztián Vida ◽  
Rachael M. Roettenbacher
Keyword(s):  
Machine Learning ◽  
Rotation Period ◽  
Light Curves ◽  
Consensus Algorithm ◽  
Data Sets ◽  
Learning Tools ◽  
Stellar Rotation ◽  
Data Set ◽  
Single Target ◽  
Long Time

Context. Archives of long photometric surveys, such as the Kepler database, are a great basis for studying flares. However, identifying the flares is a complex task; it is easily done in the case of single-target observations by visual inspection, but is nearly impossible for several year-long time series for several thousand targets. Although automated methods for this task exist, several problems are difficult (or impossible) to overcome with traditional fitting and analysis approaches. Aims. We introduce a code for identifying and analyzing flares based on machine-learning methods, which are intrinsically adept at handling such data sets. Methods. We used the RANSAC (RANdom SAmple Consensus) algorithm to model light curves, as it yields robust fits even in the case of several outliers, such as flares. The light curves were divided into search windows, approximately on the order of the stellar rotation period. This search window was shifted over the data set, and a voting system was used to keep false positives to a minimum: only those flare candidate points were kept that were identified as a flare in several windows. Results. The code was tested on short-cadence K2 observations of TRAPPIST-1 and on long-cadence Kepler data of KIC 1722506. The detected flare events and flare energies are consistent with earlier results from manual inspections.

Evolution and phylogenetic significance of cardioidean shell microstructure (Mollusca, Bivalvia)

2001 ◽  
Vol 75 (3) ◽  
pp. 607-643 ◽  
Author(s):  
Jay A. Schneider ◽  
Joseph G. Carter
Keyword(s):  
Phylogenetic Relationships ◽  
Outer Shell ◽  
Data Sets ◽  
Shell Layer ◽  
Shell Microstructure ◽  
Data Set ◽  
Fracture Control ◽  
Selection For ◽  
Morphologic Data ◽  
Combined Data

The shell microstructure of Carboniferous and Triassic permophorids; Triassic and Recent carditids; Devonian, Carboniferous, and Triassic crassatelloideans; and Jurassic through Recent cardioideans is examined in a phylogenetic context, using separate microstructural and morphologic data sets, as well as a combined data set. The microstructural and morphologic data sets are significantly incongruent, but the combined data set suggests that modiomorphoideans (modiomorphids and permophorids) are basal to crassatelloideans; crassatelloideans are basal to carditids (includingSeptocardia), and carditids are basal to cardiids. On the other hand, the possibility of direct permophorid ancestry for the carditid-cardiid clade cannot be excluded, as suggested by the retention of permophorid-like matted (transitional nacreous-porcelaneous) structure in some early carditids and cardiids. In the absence of stratigraphic data and other evidence for phylogenetic relationships, shell microstructure offers limited potential for assessing subfamily-level phylogenetic relationships within the Cardioidea. This is because of microstructural convergences reflecting biomechanical adaptations for fracture control and abrasion resistance, and possibly also selection for metabolic economy of secretion in tropical, oligotrophic habitats. General evolutionary trends in cardiid shell microstructure are nevertheless apparent: Cretaceous cardiids completely replaced an ancestral laminar, matted structure in their inner shell layer with non-laminar porcelaneous structures; evolved better defined CL structure, stronger reflection of the shell margins, and increased thickness or secondary loss of the ancestral prismatic outer shell layer; and, inProtocardia(Pachycardium)stantoni, added inductural deposition. Some Cenozoic cardiids then evolved wider first-order crossed lamellae, non-denticular composite prisms, composite fibrous prisms, ontogenetic submergence of a juvenile non-denticular composite prismatic outer shell layer into the CL middle shell layer, or ontogenetic submergence of the inner part of a juvenile fibrous prismatic outer shell layer into the CL middle shell layer.The shell microstructure ofHemidonax donaciformisis unusual for a cardioidean, and suggests closer affinities with the superfamily Tellinoidea than with the superfamily Cardioidea.Extensive inductural deposits inProtocardia(Pachycardium)stantoniraise the possibility that photosymbiosis evolved among some Mesozoic members of the Protocardiinae, thereby increasing the likelihood that this feature has evolved several times independently in the Cardiidae.Cemented, calcareous periostracal granules or spines are known to occur in modiolopsoideans, mytiloideans, modiomorphids, permophorids, trigonioids, astartids, cardiids, myoids, pholadomyoids, and septibranchoids. Consequently, the presence of these structures is not necessarily indicative of close anomalodesmatan affinities.

Queries related to COVID-19: a more effective retrieval through finetuned ALBERT with BM25L question answering system

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Deepthi Godavarthi ◽  
Mary Sowjanya A.
Keyword(s):  
Question Answering ◽  
Relevant Information ◽  
Medical Community ◽  
Data Sets ◽  
Data Set ◽  
Content Type ◽  
Benchmark Data ◽  
Open Research ◽  
First Time ◽  
Scientific Questions

Purpose The purpose of this paper is to build a better question answering (QA) system that can furnish more improved retrieval of answers related to COVID-19 queries from the COVID-19 open research data set (CORD-19). As CORD-19 has an up-to-date collection of coronavirus literature, text mining approaches can be successfully used to retrieve answers pertaining to all coronavirus-related questions. The existing a lite BERT for self-supervised learning of language representations (ALBERT) model is finetuned for retrieving all COVID relevant information to scientific questions posed by the medical community and to highlight the context related to the COVID-19 query. Design/methodology/approach This study presents a finetuned ALBERT-based QA system in association with Best Match25 (Okapi BM25) ranking function and its variant BM25L for context retrieval and provided high scores in benchmark data sets such as SQuAD for answers related to COVID-19 questions. In this context, this paper has built a QA system, pre-trained on SQuAD and finetuned it on CORD-19 data to retrieve answers related to COVID-19 questions by extracting semantically relevant information related to the question. Findings BM25L is found to be more effective in retrieval compared to Okapi BM25. Hence, finetuned ALBERT when extended to the CORD-19 data set provided accurate results. Originality/value The finetuned ALBERT QA system was developed and tested for the first time on the CORD-19 data set to extract context and highlight the span of the answer for more clarity to the user.

Assessing the usefulness of histone H3, U2 snRNA and 28S rDNA in analyses of polychaete relationships

1999 ◽  
Vol 47 (5) ◽  
pp. 499 ◽  
Author(s):  
S. Brown ◽  
G. Rouse ◽  
P. Hutchings ◽  
D. Colgan
Keyword(s):  
Maximum Parsimony ◽  
Sequence Data ◽  
Histone H3 ◽  
28S Rdna ◽  
Maximum Parsimony Analysis ◽  
Data Sets ◽  
Data Set ◽  
U2 Snrna ◽  
Dna Sequence Data ◽  
Combined Data

DNA sequence data from for histone H3 (34 species), U2 snRNA (34 species) and two segments (D1 and D9–10 expansion regions) of 28S rDNA (28 and 26 species, respectively) have been collected to investigate the relationships of polychaetes. Representatives of all of the major morphologically identified clades were used, as well as members of the Sipuncula, Echiura, Turbellaria, Clitellata and Siboglinidae (formerly the phyla Pogonophora and Vestimentifera). Maximum parsimony analyses of the separate data sets gave conflicting results and none conformed closely to previous results based on morphology. Instead each data set provided corroboration of a few of the morphological groupings, usually pairing, though inconsistently, members of the same family. Higher groupings proposed on morphological grounds were rarely recovered. Maximum parsimony analysis of the combined data, excluding areas of uncertain alignment, recovered some morphological groupings such as Cirratulidae, Terebellidae, scale worms and eunicimorphs, and did not significantly contradict others. However, some expected groupings were not recovered. Surprisingly, the fanworms (Sabellidae and Serpulidae) were not shown as sister taxa, and monophyly of Phyllodocida, a morphologically well corroborated clade, required four more steps than most parsimonious trees. Aciculata was not seen in our analyses, although it was the most strongly supported large clade in Rouse and Fauchald (1997, Cladistics and polychaetes. Zoologica Scripta 26, 138–204). Trees constrained to show Aciculata as monophyletic were 18 steps longer than the most parsimonious trees. If trees are rooted on sipunculans rather than the nematode, Aciculata is nearly recovered, being rendered paraphyletic by the inclusion of the sister-pair of Oweniidae and Chaetopteridae. As suggested by some recent morphological and molecular analyses, Siboglinidae and Clitellata may well have sister groups among polychaetes. The morphologically aberrant Sternaspidae are closest to members of Terebellida in the present analyses, supporting the placement of Rouse and Fauchald. Interesting results deserving further assessment concern the placement of Chaetopteridae, Oweniidae and Sipuncula.

scholarly journals An overview of two years of ozone radio soundings over Cotonou as part of AMMA

2009 ◽  
Vol 9 (16) ◽  
pp. 6157-6174 ◽  
Author(s):  
V. Thouret ◽  
M. Saunois ◽  
A. Minga ◽  
A. Mariscal ◽  
B. Sauvage ◽  
...  
Keyword(s):  
West Africa ◽  
Biomass Burning ◽  
Lower Stratosphere ◽  
Lower Troposphere ◽  
Data Sets ◽  
Wet Season ◽  
Data Set ◽  
In Situ Data ◽  
Multidisciplinary Analysis ◽  
First Time

Abstract. As part of the African Monsoon Multidisciplinary Analysis (AMMA) program, a total of 98 ozone vertical profiles over Cotonou, Benin, have been measured during a 26 month period (December 2004–January 2007). These regular measurements broadly document the seasonal and interannual variability of ozone in both the troposphere and the lower stratosphere over West Africa for the first time. This data set is complementary to the MOZAIC observations made from Lagos between 0 and 12 km during the period 1998–2004. Both data sets highlight the unique way in which West Africa is impacted by two biomass burning seasons: in December–February (dry season) due to burning in the Sahelian band and in June-August (wet season) due to burning in southern Africa. High interannual variabilities between Cotonou and Lagos data sets and within each data set are observed and are found to be a major characteristic of this region. In particular, the dry and wet seasons are discussed in order to set the data of the Special Observing Periods (SOPs) into a climatological context. Compared to other dry and wet seasons, the 2006 dry and wet season campaigns took place in rather high ozone environments. During the sampled wet seasons, southern intrusions of biomass burning were particularly frequent with concentrations up to 120 ppbv of ozone in the lower troposphere. An insight into the ozone distribution in the upper troposphere and the lower stratosphere (up to 26 km) is given. The first tropospheric columns of ozone based on in-situ data over West Africa are assessed. They compare well with satellite products on seasonal and interannual time-scales, provided that the layer below 850 hPa where the remote instrument is less sensitive to ozone, is removed.

scholarly journals Shared Data Set for Free-Text Keystroke Dynamics Authentication Algorithms

2021 ◽  
Author(s):  
Augustin-Catalin Iapa ◽  
Vladimir-Ioan Cretu
Keyword(s):  
Relevant Information ◽  
Future Research ◽  
Time Interval ◽  
Free Text ◽  
Data Sets ◽  
Keystroke Dynamics ◽  
Data Set ◽  
Continuous Growth ◽  
Public Data ◽  
Depth Analysis

Identifying or authenticating a computer user are necessary steps to keep systems secure on the network and to prevent fraudulent users from accessing accounts. Keystroke dynamics authentication can be used as an additional authentication method. Keystroke dynamics involves in-depth analysis of how you type on the keyboard, analysis of how long a key is pressed or the time between two consecutive keys. This field has seen a continuous growth in scientific research. In the last five years alone, about 10,000 scientific researches in this field have been published. One of the main problems facing researchers is the small number of public data sets that include how users type on the keyboard. This paper aims to provide researchers with a data set that includes how to type free text on the keyboard by 80 users. The data were collected in a single session via a web platform. The dataset contains 410,633 key-events collected in a total time interval of almost 24 hours. In similar research, most datasets are with texts written by users in English. The language in which the users wrote for this research is Romanian. This paper also provides an extensive analysis of the data set collected and presents relevant information for the analysis of the data set in future research.

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