Development of an Ultrasensitive Dual-Channel Flow Cytometer for the Individual Analysis of Nanosized Particles and Biomolecules

2009 ◽  
Vol 81 (7) ◽  
pp. 2555-2563 ◽  
Author(s):  
Lingling Yang ◽  
Shaobin Zhu ◽  
Wei Hang ◽  
Lina Wu ◽  
Xiaomei Yan
Keyword(s):  
Channel Flow ◽  
Flow Cytometer ◽  
Nanosized Particles ◽  
Individual Analysis ◽  
Dual Channel ◽  
The Individual

scholarly journals Statistical Uncertainty of DNS in Geometries without Homogeneous Directions

2021 ◽  
Vol 11 (4) ◽  
pp. 1399
Author(s):  
Jure Oder ◽  
Cédric Flageul ◽  
Iztok Tiselj
Keyword(s):  
Channel Flow ◽  
A Priori ◽  
Time Integration ◽  
Navier Stokes ◽  
Statistical Uncertainty ◽  
Time Step ◽  
Order Of Magnitude ◽  
Averaging Time ◽  
The Individual ◽  
Time Required

In this paper, we present uncertainties of statistical quantities of direct numerical simulations (DNS) with small numerical errors. The uncertainties are analysed for channel flow and a flow separation case in a confined backward facing step (BFS) geometry. The infinite channel flow case has two homogeneous directions and this is usually exploited to speed-up the convergence of the results. As we show, such a procedure reduces statistical uncertainties of the results by up to an order of magnitude. This effect is strongest in the near wall regions. In the case of flow over a confined BFS, there are no such directions and thus very long integration times are required. The individual statistical quantities converge with the square root of time integration so, in order to improve the uncertainty by a factor of two, the simulation has to be prolonged by a factor of four. We provide an estimator that can be used to evaluate a priori the DNS relative statistical uncertainties from results obtained with a Reynolds Averaged Navier Stokes simulation. In the DNS, the estimator can be used to predict the averaging time and with it the simulation time required to achieve a certain relative statistical uncertainty of results. For accurate evaluation of averages and their uncertainties, it is not required to use every time step of the DNS. We observe that statistical uncertainty of the results is uninfluenced by reducing the number of samples to the point where the period between two consecutive samples measured in Courant–Friedrichss–Levy (CFL) condition units is below one. Nevertheless, crossing this limit, the estimates of uncertainties start to exhibit significant growth.

scholarly journals Splenomegaly in relation to Schistosoma mansoni egg counts: a population based study

1986 ◽  
Vol 28 (6) ◽  
pp. 389-394 ◽  
Author(s):  
Maria Fernanda Furtado de Lima e Costa ◽  
R. S. Bocha ◽  
Naftale Katz
Keyword(s):  
Geometric Mean ◽  
Age Groups ◽  
Individual Case ◽  
Population Based ◽  
Control Analysis ◽  
Ecological Data ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Individual Analysis ◽  
The Individual

A cross: sectional survey on schistosomiasis was done in Comercinho (Minas Gerais State, Brazil), a town with 1474 inhabitants. Stool (Kato-Katz method) and physical examinations were done on 90% of the population and on 84% of the individuals over 2 years of age, respectively. The ecological and individual (case-control) analysis were used to investigate the relation between splenomegaly and S. mansoni egg counts in different age groups. In the ecological analysis there was a clearly correspondence between higher geometric mean of eggs and higher percentage of splenomegaly in the age groups 5-9 and 10-12 years. In the individual analysis it was found that only in the youngest individuals (5-8 or 5-9 years old) the splenomegaly was related with higher mean egg counts in the feces, having been a tendency to the decrease of excretion of eggs in patients with splenomegaly as the age increased. These results strongly suggest that the ecological data are' better indicator of the severity of schistosomiasis in endemic areas, as the decrease of the egg excretion in patients with splenomegaly may be a confounding variable for the individual analysis.

Determinants of corporate effective tax rates: evidence from the euro area

2020 ◽  
Vol 33 (3/4) ◽  
pp. 427-444
Author(s):  
Antonio Barbera ◽  
Paloma Merello ◽  
Rafael Molina
Keyword(s):  
Euro Area ◽  
Listed Companies ◽  
Tax Rates ◽  
Effective Tax Rates ◽  
Content Type ◽  
Individual Analysis ◽  
The Individual ◽  
The Impact ◽  
Generalized Moments ◽  
Positive Effect

PurposeThe purpose of this paper is to investigate the effect of the determinants of corporate effective tax rates (ETR) of listed companies in euro area.Design/methodology/approachWith a large and recent panel of 2,870 listed companies for the period 2005–2016, the authors use the generalized moments method (GMM) to estimate global models for three groups of countries and specific models for six selected countries: Germany, Spain, France, Italy, Belgium and Greece.FindingsThe results confirm that ETR have different determinants depending on the countries analyzed. There is a significantly positive relationship with leverage and negative with size and financial profitability. However, economic profitability shows a statistically positive effect in the new members, but negative effect on old ones. In the individual analysis, Germany and Spain maintain this negative association with return on assets (ROA), but Belgium and Greece show a positive effect. The effect of the economic cycle shows statistically relevant, negatively in Germany but positively in Belgium and Greece.Originality/valueThis paper makes a novel contribution to the current debate on the need for harmonization of corporate income tax in the European Union (EU). For the first time, the group of countries whose common currency is the euro is considered with a great level of detail. In addition, the impact derived from the enlargement of the euro area and the individual analysis of the main countries is included. The European authorities must take into account the specific differences found in the ETR determinants because it hinders to take measures that limit tax competition.

COMPUTERIZED PLATELET AGGREGOMETRY

1987 ◽  
Author(s):  
T Szabados ◽  
F Hermán ◽  
G Kollányi ◽  
P Hadházy ◽  
K Magyar
Keyword(s):  
Dose Response ◽  
In Vitro Tests ◽  
Response Curves ◽  
Dual Channel ◽  
Large Numbers ◽  
Platelet Aggregometry ◽  
Enormous Amount ◽  
Dose Response Curves ◽  
The Individual

One of the commonly used in vitro tests for assessing platelet function is a photodensitometric assay first established by Born. However the collection and analysis of aggregation data are tedious and time consuming. The single- and dual-channel aggregometers have limited utility for the analysis of large numbers of plasma samples in clinical laboratories or in studies on the mode of action of drugs.We now report on a multichannel platelet aggregome-ter system consisting of an IBM XT personal computer and three microprocessor-controlled 4 channel aggregometers. The system collects, displays and analyzes 12 different aggregation curves simultaneously, and - like other computerized systems - (1) significantly increa ses the efficiency and ease in performing the experiment, analyzing and presenting the data; (2) provides systematic storage and rapid retrieval of the data;(3) saves an enormous amount of time; (4) because of multichannel capability eliminates the effects of time-related changes in PRP on the dose-response curves.However our system has some advantages over the computerized aggregometer systems used so far: (1) since the aggregometers contain built in microprocessors they can be utilized to measure and analyse platelet aggregation without being coupled to a computer; (2) a special program helps to check the validity of the calculated parameters under visual control; (3) the individual points of the dose-response curves can be checked at any time during the experiment.

Pooling samples within microarray studies: a comparative analysis of rat liver transcription response to prototypical toxicants

2005 ◽  
Vol 22 (3) ◽  
pp. 346-355 ◽  
Author(s):  
Robert A. Jolly ◽  
Keith M. Goldstein ◽  
Tao Wei ◽  
Hong Gao ◽  
Peining Chen ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Time Course ◽  
Molecular Mechanisms ◽  
Pooled Analysis ◽  
Transcript Expression ◽  
Individual Animal ◽  
Clustering Methods ◽  
Individual Analysis ◽  
Transcript Profiles ◽  
The Individual

Combining or pooling individual samples when carrying out transcript profiling using microarrays is a fairly common means to reduce both the cost and complexity of data analysis. However, pooling does not allow for statistical comparison of changes between samples and can result in a loss of information. Because a rigorous comparison of the identified expression changes from the two approaches has not been reported, we compared the results for hepatic transcript profiles from pooled vs. individual samples. Hepatic transcript profiles from a single-dose time-course rat study in response to the prototypical toxicants clofibrate, diethylhexylphthalate, and valproic acid were evaluated. Approximately 50% more transcript expression changes were observed in the individual (statistical) analysis compared with the pooled analysis. While the majority of these changes were less than twofold in magnitude (∼80%), a substantial number were greater than twofold (∼20%). Transcript changes unique to the individual analysis were confirmed by quantitative RT-PCR, while all the changes unique to the pooled analysis did not confirm. The individual analysis identified more hits per biological pathway than the pooled approach. Many of the transcripts identified by the individual analysis were novel findings and may contribute to a better understanding of molecular mechanisms of these compounds. Furthermore, having individual animal data provided the opportunity to correlate changes in transcript expression to phenotypes (i.e., histology) observed in toxicology studies. The two approaches were similar when clustering methods were used despite the large difference in the absolute number of transcripts changed. In summary, pooling reduced resource requirements substantially, but the individual approach enabled statistical analysis that identified more gene expression changes to evaluate mechanisms of toxicity. An individual animal approach becomes more valuable when the overall expression response is subtle and/or when associating expression data to variable phenotypic responses.

scholarly journals The Fault-Tolerant Quad-Channel Brushless Direct Current Motor

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3667
Author(s):  
Mariusz Korkosz ◽  
Piotr Bogusz ◽  
Jan Prokop
Keyword(s):  
Permanent Magnet ◽  
Direct Current ◽  
Single Channel ◽  
Fault Tolerant ◽  
Electrical Energy ◽  
Dual Channel ◽  
Energy Processing ◽  
Active Channels ◽  
Drive Systems ◽  
The Individual

In this study, a permanent magnet brushless direct current machine with multi-phase windings is proposed for critical drive systems. We have named the solution, which has four-stator winding, a quad-channel permanent magnet brushless direct current (QCBLDC) motor. The stator windings are supplied by four independent power converters under quad-channel operation (QCO) mode. After a fault in either one, two, or three channels, further operation of the machine can be continued in triple-channel operation (TCO) mode, dual-channel operation (DCO) mode, or single-channel operation (SCO) mode. In this paper, a novel mathematical model is proposed for a QCBLDC machine. This model takes into account the nonlinearity of a magnetic circuit and all of the couplings between the phases within a given channel, as well as between channels. Based on numerical calculations, the static electromagnetic moment and the coupled fluxes were determined for the individual windings of the variants and work modes being analyzed. A normal work condition can be achieved in the QCO or DCO modes. For the DCO mode, an acceptable case uses a balanced magnetic pull (A and C channels supplied). The DCO A and B type work mode is comparable to the DCO A and C mode with regard to its efficiency in processing electrical energy. The vibroacoustic parameters of this mode, however, are much worse. In fault states, TCO, DCO, and SCO work modes are possible. As the number of active channels decreases, the efficiency of energy processing also decreases. In a critical situation, the motor works in overload mode (SCO mode). Laboratory tests conducted for one of the variants demonstrated that the TCO work mode is characterized by worse vibroacoustic parameters than the DCO A and C mode.

Emerging 4th Generation Analytical Technology for the Individual Analysis of Multiple Families of Co-mingled Scale Inhibitors in Deepwater Wells

2012 ◽  
Author(s):  
Alan K. Thompson ◽  
Stephen Mark Heath ◽  
Bjorn Juliussen ◽  
Thomas Gundersen ◽  
Alf Terje Andresen ◽  
...  
Keyword(s):  
Individual Analysis ◽  
The Individual ◽  
Analytical Technology

scholarly journals Análisis de la política de motivación desde una perspectiva de género

2021 ◽  
Vol 12 (1) ◽  
pp. 51
Author(s):  
Ana Paula Moreno Cervera ◽  
Lourdes Canós Darós ◽  
Ester Guijarro
Keyword(s):  
Ad Hoc ◽  
Business Management ◽  
Motivational Factors ◽  
Measurement Tool ◽  
Motivating Factors ◽  
Gender Perspective ◽  
Individual Analysis ◽  
The Individual ◽  
Selection Of ◽  
The Ideal

The main objective of this paper is to present a method to analyze the motivational policy based on a gender perspective. To do this, we carry out the study of the motivating factors with the greatest presence in the company and the individual analysis of each one of them. We continue with their assessment based on the importance they have for each worker in their job position, using an adequacy coefficient as a measurement tool, comparing this assessment with the ideal of the company. We continue to show different results depending on the level of assessment of the motivational factors and comparing the answers according to the age, gender, etc., of the employees. From the analysis we observe that there are differences in the selection of factors and in the valuation of some of the choosen factors according to the gender of the employees.We conclude by presenting the implications that these results have for business management, highlighting the applicability of the method to any organization by using ad hoc designs.

scholarly journals Characterization of a thermal decomposition chemical ionization mass spectrometer for the measurement of peroxy acyl nitrates (PANs) in the atmosphere

2011 ◽  
Vol 11 (3) ◽  
pp. 8461-8513 ◽  
Author(s):  
W. Zheng ◽  
F. M. Flocke ◽  
G. S. Tyndall ◽  
A. Swanson ◽  
J. J. Orlando ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Mass Spectrometer ◽  
Thermal Dissociation ◽  
Ionization Mass ◽  
Operation Conditions ◽  
Dual Channel ◽  
Acyl Radicals ◽  
Secondary Reactions ◽  
The Individual

Abstract. This paper presents a detailed laboratory characterization of a thermal dissociation ionization mass spectrometer (TD-CIMS) for the atmospheric measurement of Peroxyacetyl nitrate (PAN) and its homologues. PANs are efficiently dissociated in a heated inlet tube and the resulting peroxy acyl radicals are reacted with I– ions in a flow tube. The CIMS detects the corresponding carboxylate ions to give a specific and quantitative measurement of each PAN species. PAN, peroxypropionyl nitrate (PPN), peroxyisobutyryl nitrate (PiBN), peroxy-n-butyryl nitrate (PnBN), peroxyacryloyl nitrate (APAN), peroxycrotonyl nitrates (CPAN) and peroxymethacryloyl nitrate (MPAN) were cross-calibrated with both a dual channel GC/ECD and a total odd-nitrogen (NOy) instrument for the NCAR TD-CIMS' typical aircraft operation conditions. In addition, the instrument sensitivity to a number of more exotic PAN homologues (peroxyhydroxyacetyl nitrate, methoxyformyl peroxynitrate, and peroxybenzoyl nitrate) was evaluated qualitatively by comparisons with a long-path FTIR instrument. The sensitivity for PPN is slightly higher than that of PAN. Larger aliphatic and olefinic PAN compounds generally showed lower sensitivities. These differences are owing to secondary reactions in the thermal decomposition region, which either reduce the yield of peroxy acyl radicals or cause losses of these radicals through intramolecular decomposition. The relative importance of these secondary reactions varies considerably between different PAN species. Results also indicate that the reaction of the peroxy acyl radicals with the ion-water cluster, I–(H2O)n proceeds about an order of magnitude faster than with I– alone. Variations among the individual PAN species at very low water vapor were observed. The results call for careful evaluation of each PAN species to be measured and for each desired operating condition of a TD-CIMS instrument.

scholarly journals Circadian rhythms and locomotor activity of smolts of the european river lamprey lampetra fluviatilis (l.)

2019 ◽  
Vol 484 (2) ◽  
pp. 243-246
Author(s):  
A. O. Zvezdin ◽  
D. S. Pavlov ◽  
A. V. Kucheryavyy ◽  
I. A. Tsimbalov
Keyword(s):  
Circadian Rhythm ◽  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Channel Flow ◽  
Downstream Migration ◽  
Nocturnal Activity ◽  
Lampetra Fluviatilis ◽  
River Lamprey ◽  
The Individual ◽  
Short Time

Locomotor activity was investigated in smolts of the European river lamprey at alternation of light and darkness (12/12 h) and in the dark. Two groups of smolts were discerned differing in the level of locomotor activity. The presence of the circadian rhythm in smolts has been revealed, and its role in downstream migration has been shown. The locomotor activity leading smolts to channel flow increases with decreasing illumination at evening twilight. The period of high nocturnal activity is completed a short time before morning twilight, under the action of the individual circadian rhythm. This decreases the probability of impact of predators on migrating smolts.

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