291 research outputs found
Fractional order calculus on the estimation of short-circuit impedance of power transformers
This paper reports investigation on the use of fractional order calculus to analytically estimate the inlfuence of skin and proximity effects in the short circuit impedance of power transformers. The aim is to better characterize the medium frequency range behavior of leakage inductances of power transformer models, which include terms to represent the magnetic field diffusion process in the windigns. Comparisons between calculated and measured values are shown and discussed.N/
On the Estimation of the Short-Circuit Impedance of Power Transformers Using Fractional Order Calculus
This paper reports investigation on the estimation of the short circuit
impedance of power transformers, using fractional order calculus to analytically
study the influence of the diffusion phenomena in the windings. The aim is to better
characterize the medium frequency range behavior of leakage inductances of power
transformer models, which include terms to represent the magnetic field diffusion
process in the windings. Comparisons between calculated and measured values are
shown and discussed
Short-Circuit Impedance of Power Transformers: the Fractional Order Calculus Approach
First IFAC Workshop on Fractional Differentiation and Its Application - 19-21 July 2004, Enseirb, Bordeaux, France - FDA'04This paper reports investigation on the modeling of the short circuit
impedance of power transformers, using fractional order calculus, analyzing the
influence of the diffusion phenomena in the windings. This aims to better
characterize the medium frequency range behavior of leakage inductances of power
transformer models, which include terms to represent the magnetic field diffusion in
the windings. Calculated and measured values are shown and compared
Evaluation of autofocus functions in molecular cytogenetic analysis
This work describes a systematic evaluation of several
autofocus functions used for analytical fluorescent image
cytometry studies of counterstained nuclei. Focusing is the
first step in the automatic fluorescence in situ hybridization
analysis of cells. Thirteen functions have been evaluated
using qualitative and quantitative procedures. For the last
of these procedures a figure-of-merit (FOM) is defined and
proposed. This new FOM takes into account five important
features of the focusing function. Our results show that
functions based on correlation measures have the best
performance for this type of image.Publicad
Diversity and inclusion in conservation: A proposal for a marine diversity network
Low diversity among scientists and practitioners is rampant in conservation. Currently,
conservation professionals do not reflect the same diversity of perspectives and
experiences of the world as the communities who bear the largest burden for
implementing—or adverse consequences for failing to implement—conservation action.
Acknowledging and describing the problem is important. But policies and programmes
must also be put in place to correct it. Here, we highlight some measurable benefits
of workforce diversity, and give an overview of some of the barriers to inclusion
in marine conservation that help perpetuate low workforce diversity. Importantly, we
underscore actions that both individuals and groups can take to alleviate such barriers.
In particular, we describe the establishment of an online Marine Diversity Network,
which conference participants proposed during a focus group meeting at the 4th
International Marine Conservation Congress. The network will serve to bring together
people from across the globe, from a variety of backgrounds, and from all career stages,
to share knowledge, experiences and ideas, to provide and receive mentorship in marine
conservation, and to forge new collaborations. Removing barriers to diverse participation
requires coordinated, mindful actions by individuals and organizations. We hope that the
proposed network and other actions presented in this paper find widespread support,
and that they might serve both as inspiration and guide to other groups concerned with
increasing diversity and inclusivity
Efficacy of ImageJ in the assessment of apoptosis
<p>Abstract</p> <p>Objective</p> <p>To verify the efficacy of ImageJ 1.43 n in determining the extent of apoptosis which is a complex and multistep process.</p> <p>Study Design</p> <p>Cisplatin in different concentrations was used to induce apoptosis in cultured Hep2 cells. Cell viability assay and nuclear image analysis of stained Hep2 cells were used to discriminate apoptotic cells and cells suspected to be undergoing apoptosis from control cells based on parameters such as nuclear area, circularity, perimeter and nuclear area factor (NAF), in association with visual morphology.</p> <p>Results</p> <p>Image analysis revealed a progressive and highly significant decrease in nuclear area factor detected in apoptotic cells and in cells suspected of undergoing apoptosis compared to the control cells (P-values < 0.01). Some of the other studied parameters showed also the same trend. This decrease was assumed to indicate DNA loss. Image analysis results correlated positively and significantly with the results obtained by cell viability assay (R = 0.958, P-value = 0.042). NAF was the most reliable parameter in assessment of apoptosis.</p> <p>Conclusion</p> <p>Nuclear area factor can be calculated using powerful free and open-source software. Consequently, a quantitative measure of apoptosis can be obtained that is linked to morphological changes. ImageJ 1.43 n may therefore provide a useful tool for the assessment and discrimination of apoptotic cells.</p> <p>Virtual slides</p> <p>The virtual slide(s) for this article can be found here:</p> <p><url>http://www.diagnosticpathology.diagnomx.eu/vs/5929043086367338</url></p
Entrepreneurial Orientation and the Family Firm: Mapping the Field and Tracing a Path for Future Research
ABSTRACT: Despite several calls for the further study of entrepreneurial orientation in family firms, we still have a fragmented understanding of this topic, whose full potential has yet to be reached. To shed new light on this issue, this article first maps the family business field by carrying out a systematic review and content analysis of the 78 articles identified at the confluence of entrepreneurial orientation and family firms. Our study describes and critically assesses previous research as well as the conclusions reached. Second, this article identifies the main research gaps and provides a path for future investigations
Issues in the Differential Diagnosis of Uterine Low-grade Endometrioid Carcinoma, Including Mixed Endometrial Carcinomas: Recommendations from the International Society of Gynecological Pathologists
This article provides practical recommendations developed from the International Society of Gynecological Pathologists Endometrial Carcinoma Project to address 4 issues that may arise in the diagnosis of uterine corpus low-grade endometrioid carcinoma: (1) The distinction between atypical hyperplasia and low-grade endometrioid carcinoma. (2) The distinction between low-grade endometrioid carcinoma and serous carcinoma. (3) The distinction between corded and hyalinized or spindle cell variants of low-grade endometrioid carcinoma and carcinosarcoma. (4) The diagnostic criteria for mixed endometrial carcinomas, a rare entity that should be diagnosed only after exclusion of a spectrum of tumors including morphologic variants of endometrioid carcinoma, dedifferentiated endometrial carcinoma, carcinosarcoma, and endometrial carcinomas with ambiguous morphology
In Vivo Quantification of Placental Insufficiency by BOLD MRI: A Human Study
Fetal health is critically dependent on placental function, especially placental transport of oxygen from mother to fetus. When fetal growth is compromised, placental insufficiency must be distinguished from modest genetic growth potential. If placental insufficiency is present, the physician must trade off the risk of prolonged fetal exposure to placental insufficiency against the risks of preterm delivery. Current ultrasound methods to evaluate the placenta are indirect and insensitive. We propose to use Blood-Oxygenation-Level-Dependent (BOLD) MRI with maternal hyperoxia to quantitatively assess mismatch in placental function in seven monozygotic twin pairs naturally matched for genetic growth potential. In-utero BOLD MRI time series were acquired at 29 to 34 weeks gestational age. Maps of oxygen Time-To-Plateau (TTP) were obtained in the placentas by voxel-wise fitting of the time series. Fetal brain and liver volumes were measured based on structural MR images. After delivery, birth weights were obtained and placental pathological evaluations were performed. Mean placental TTP negatively correlated with fetal liver and brain volumes at the time of MRI as well as with birth weights. Mean placental TTP positively correlated with placental pathology. This study demonstrates the potential of BOLD MRI with maternal hyperoxia to quantify regional placental function in vivo.National Institutes of Health (U.S.) (Grant U01 HD087211)National Institutes of Health (U.S.) (Grant R01 EB017337
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