bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Colistin on Phospholipid‐Based Activated Partial Thromboplastin Time Clotting Assay Results in Patients Receiving Concomitant Heparin Therapy
Authors: Brown Jack , Aitken Samuel L. , Mackey Melissa , Sawkar Sonia , Ashley Elizabeth Dodds
Published: March 2011

Study Objective. To determine whether intravenous colistin therapy has an effect on the results of the phospholipid‐based activated partial thromboplastin time (aPTT) clotting assays containing cephalin in patients receiving concomitant heparin therapy.

Design. Retrospective medical record review.

Setting. University‐affiliated teaching institution.

Patients. Thirty‐six patients treated with intravenous colistin for at least 48 hours between January 1, 2005, and January 1, 2010, who were receiving heparin for at least 48 hours before colistin was started, and had aPTT tests performed at least 2 days before, during, and at least 2 days after treatment with colistin.

Measurements and Main Results. Repeated‐measures analysis of variance testing was performed to determine if significant differences in aPTT results before, during, and after colistin therapy existed. Of a total of 120 courses of colistin therapy, only 36 met the inclusion criteria. The mean ± SD aPTT was 52.3 ± 20.4 seconds before administration of colistin, 51.1 ± 16.6 seconds during colistin therapy, and 51.3 ± 13.6 seconds after administration of colistin (p=0.9). Heparin infusion rates were adjusted 12 times and heparin withheld twice at least 2 days before colistin therapy was started, infusion rates were changed 8 times and heparin withheld once during colistin therapy, and infusion rates were changed 10 times and heparin withheld once at least 2 days after colistin therapy.

Conclusion. Colistin therapy had no significant effect on the cephalin‐based aPTT testing results in patients receiving concomitant heparin therapy. Further analyses are required to confirm these findings.
Clinical Perspectives on the Role of the Human Papillomavirus Vaccine in the Prevention of Cancer
Authors: Julius Justin M. , Ramondeta Lois , Tipton Katherine A. , Lal Lincy S. , Schneider Karen , Smith Judith A.
Published: March 2011

The role of human papillomavirus (HPV) in the genesis of cervical cancer has been well documented, and an increasing body of literature exists with regard to the role of HPV in other cancers, including cancers of the head and neck. With the recent expansion of the United States Food and Drug Administration's approval of the quadrivalent HPV virus‐like particle vaccine to include men and boys and approval of the bivalent vaccine this year, the controversies regarding who should be vaccinated, at what age is vaccination most appropriate, and the limitations of the available HPV vaccines are increasing. Health care providers are challenged with evaluating the current, but continually changing, clinical evidence when making critical decisions for their patients. A literature search of MEDLINE and SciVerse Scopus was conducted for articles published from 1998–April 2010 regarding HPV, HPV‐related cancers, and HPV vaccines. Although both HPV vaccines were greater than 90% effective in the prevention of cervical cancer precursors in an according‐to‐protocol cohort, both vaccines were significantly less effective in the intent‐to‐treat population. In patients who achieved seroconversion, the geometric mean titers decrease dramatically within the first 2 years after vaccination, and then continue to decline at a slower rate. No effective antibody titer has been defined for either vaccine, and no studies have been conducted with documented HPV exposure after vaccination. With low efficacy rates in an intent‐to‐treat population and the potential for waning immunity, it is imperative for women to continue to receive regular Pap tests and gynecologic examinations. Although vaccine administration was shown to be cost‐effective when administered to adolescent girls, many of these simulations overestimated the durability of protection, efficacy rates in sexually active women, impact of incomplete vaccination, or necessity of boosters in the future. Whereas the introduction of the HPV vaccine was an enormous advancement in the cancer prevention research arena, optimization of its clinical use is still needed.
Vigabatrin for Infantile Spasms
Authors: Pesaturo Kimberly A. , Spooner Linda M. , Belliveau Paul
Published: March 2011

Infantile spasms describe a pediatric epilepsy syndrome characterized by frequent clusters of brief symmetric muscle contractions; the condition is often associated with developmental delay. When infantile spasms are accompanied by hypsarrhythmia on electroencephalogram, the condition is labeled West syndrome. The mainstay of treatment for infantile spasms is adrenocorticotropic hormone; however, vigabatrin, a vinyl derivative of 7‐aminobutyric acid, has been used for the treatment of infantile spasms in Europe since 1989. In 2009, vigabatrin was approved by the United States Food and Drug Adminstration (FDA) for use as monotherapy in the treatment of infantile spasms in patients aged 1 month‐2 years when the benefits of treatment outweigh the risks. Results from numerous trials examining the role of vigabatrin in infantile spasms have been published; many of these trials were small, open‐label, or noncontrolled. Although clinical trials have provided some insight into the utility of vigabatrin for the treatment of infantile spasms, these studies have notable limitations. In addition, vigabatrin is associated with a black‐box warning that describes the potential for permanent bilateral concentric visual field defects. Currently, vigabatrin is available through a manufacturer‐sponsored program in accordance with its FDA‐approved Risk Evaluation and Mitigation Strategy. Although several guidelines recommend vigabatrin as a first‐line therapy for infantile spasms, specifically infantile spasms related to tuberous sclerosis, it is still unclear whether vigabatrin should supersede hormone therapy as first‐line therapy. Further research comparing the two therapies is needed.
Successful Treatment with Drotrecogin alfa (activated) in a Pregnant Patient with Severe Sepsis
Authors: Eppert Heather D. , Goddard Kara B. , King Crystal L.
Published: March 2011

Sepsis remains one of the leading causes of mortality during pregnancy. Because of the inherent limitations of conducting scientific investigations during pregnancy, a great deal of clinical decision making is based on observational reports, an understanding of the physiologic changes of pregnancy, and consideration for risk to the fetus. We describe a 20‐year‐old pregnant woman at 20 weeks' gestation who was admitted to an obstetric ward for dehydration and a urinary tract infection. Approximately 36 hours later, the patient's clinical status deteriorated, with the development of mental status changes, acute respiratory failure, and renal failure. Drotrecogin alfa (activated) was started, as the patient's Acute Physiology and Chronic Health Evaluation II score was 27 (> 25 is the typical score required for drotrecogin alfa [activated] therapy); within 48 hours the patient's clinical status dramatically improved. The patient completed 96 uninterrupted hours of therapy and was subsequently discharged after a 15‐day hospitalization, with no apparent sequelae. Approximately 17 weeks later, the patient gave birth to a 3.42‐kg female infant with no congenital abnormalities. To our knowledge, this represents the second case report to describe the use of drotrecogin alfa (activated) along with the status of the mother and fetus both after completion of therapy and after subsequent delivery. Because of the threat of mortality from sepsis during pregnancy, combined with the inherent limitations associated with clinical research during pregnancy further reports and investigation into the treatment of sepsis in the pregnant patient are warranted.
Topical Testosterone for Breast Cancer Patients with Vaginal Atrophy Related to Aromatase Inhibitors: A Phase I/II Study
Authors: Witherby Sabrina , Johnson Julia , Demers Laurence , Mount Sharon , Littenberg Benjamin , Maclean Charles D. , Wood Marie , Muss Hyman
Published: March 2011

Learning Objectives

After completing this course, the reader will be able to: Evaluate early data regarding the impact of daily vaginal testosterone on estradiol and testosterone levels in breast cancer patients receiving treatment with aromatase inhibitors.Explain the potential clinical benefits of vaginal testosterone therapy to treat vaginal atrophy in women with breast cancer receiving long-term aromatase inhibitor therapy.

This article is available for continuing medical education credit at CME.TheOncologist.com

Purpose.

Controversy exists about whether vaginal estrogens interfere with the efficacy of aromatase inhibitors (AIs) in breast cancer patients. With the greater incidence of vaginal atrophy in patients on AIs, a safe and effective nonestrogen therapy is necessary. We hypothesized that vaginal testosterone cream could safely treat vaginal atrophy in women on AIs.

Methods.

Twenty-one postmenopausal breast cancer patients on AIs with symptoms of vaginal atrophy were treated with testosterone cream applied to the vaginal epithelium daily for 28 days. Ten women received a dose of 300 μg, 10 received 150 μg, and one was not evaluable. Estradiol levels, testosterone levels, symptoms of vaginal atrophy, and gynecologic examinations with pH and vaginal cytology were compared before and after therapy.

Results.

Estradiol levels remained suppressed after treatment to <8 pg/mL. Mean total symptom scores improved from 2.0 to 0.7 after treatment (p < .001) and remained improved 1 month thereafter (p = .003). Dyspareunia (p = .0014) and vaginal dryness (p <.001) improved. The median vaginal pH decreased from 5.5 to 5.0 (p = .028). The median maturation index rose from 20% to 40% (p < .001). Although improvement in total symptom score was similar for both doses (−1.3 for 300 μg, −0.8 for 150 μg; p = .37), only the 300-μg dose was associated with improved pH and maturation values.

Conclusions.

A 4-week course of vaginal testosterone was associated with improved signs and symptoms of vaginal atrophy related to AI therapy without increasing estradiol or testosterone levels. Longer-term trials are warranted.
Excess Black Mortality in the United States and in Selected Black and White High-Poverty Areas, 1980–2000
Authors: Geronimus Arline T. , Bound John , Colen Cynthia G.
Published: March 2011

Objectives. Black working-aged residents of urban high-poverty areas suffered severe excess mortality in 1980 and 1990. Our goal in this study was to determine whether this trend persisted in 2000.

Methods. We analyzed death certificate and census data to estimate age-standardized all-cause and cause-specific mortality among 16- to 64-year-old Blacks and Whites nationwide and in selected urban and rural high-poverty areas.

Results. Urban men's mortality rate estimates peaked in 1990 and declined between 1990 and 2000 back to or below 1980 levels. Evidence of excess mortality declines among urban or rural women and among rural men was modest, with some increases. Between 1980 and 2000, there was little decline in chronic disease mortality among men and women in most areas, and in some instances there were increases.

Conclusions. In 2000, despite improved economic conditions, working-age residents of the study areas still died disproportionately of early onset of chronic disease, suggesting an entrenched burden of disease and unmet health care needs. The lack of consistent improvement in death rates among working-age residents of high-poverty areas since 1980 necessitates reflection and concerted action given that sustainable progress has been elusive for this age group.
Trauma in the Neighborhood: A Geospatial Analysis and Assessment of Social Determinants of Major Injury in North America
Authors: Newgard Craig D. , Schmicker Robert H. , Sopko George , Andrusiek Dug , Bialkowski Walter , Minei Joseph P. , Brasel Karen , Bulger Eileen , Fleischman Ross J. , Kerby Jeffrey D. , Bigham Blair L. , Warden Craig R. ,   the Resuscitation Outcomes Consortium Investigators
Published: March 2011

Objectives. We sought to identify and characterize areas with high rates of major trauma events in 9 diverse cities and counties in the United States and Canada.

Methods. We analyzed a prospective, population-based cohort of injured individuals evaluated by 163 emergency medical service agencies transporting patients to 177 hospitals across the study sites between December 2005 and April 2007. Locations of injuries were geocoded, aggregated by census tract, assessed for geospatial clustering, and matched to sociodemographic measures. Negative binomial models were used to evaluate population measures.

Results. Emergency personnel evaluated 8786 major trauma patients, and data on 7326 of these patients were available for analysis. We identified 529 (13.7%) census tracts with a higher than expected incidence of major trauma events. In multivariable models, trauma events were associated with higher unemployment rates, larger percentages of non-White residents, smaller percentages of foreign-born residents, lower educational levels, smaller household sizes, younger age, and lower income levels.

Conclusions. Major trauma events tend to cluster in census tracts with distinct population characteristics, suggesting that social and contextual factors may play a role in the occurrence of significant injury events.
Private Regulation in the Global Economy: A (P)Review
Authors: Büthe Tim
Published: March 2011

This introduction to the special issue combines a review of the existing literature about the causes and consequences of private regulation in the global economy with a preview of the articles in this issue. To organize this (p)review, I introduce a conceptual model “beyond supply and demand,” which distinguishes three major subsets of stakeholders of global private regulation, which may (but need not) overlap: the political actors who call for private regulation, the rule-makers who provide such governance for the global economy, and what I call the “targets” of the private regulations, who are supposed to behave according to these private rules. I then highlight the three core questions addressed by the contributions to the special issue: (1) How do private bodies attain regulatory authority; why do private regulators provide governance; and why do the targets of the rules comply? (2) Who governs the global economy through private regulations? And (3) what are the effects of private regulation, and how does the rise of private regulation affect public regulatory authority and capacity?
Global Private Politics: A Research Agenda
Authors: Büthe Tim
Published: March 2011

In this concluding essay to the special issue on Private Regulation in the Global Economy, I review the main findings, focused on the answers that the papers in this issue jointly suggest to the three sets of core questions noted in the introductory essay: (1) How do private bodies attain regulatory authority? Why do private regulators provide governance and why do the targets of these rules comply? (2) Who governs? Who are the key actors in private regulation and what are their motivations? (3) What is the effect of the rise of private regulation on public regulatory authority and capacity? I then identify and discuss several key issues to develop a research agenda for what I call “global private politics.”
Ship waste quantities prediction model for the port of Belgrade
Authors: Presburger-Ulnikovic Vladanka , Vukic Marija , Jancic-Heinemann Radmila , Antonovic Dusan
Published: March 2011

This study focuses on the issues related to the waste management in river
ports in general and especially in the port of Belgrade. Data on solid waste,
waste oils, oily waters, gray water and black water have been collected for a
period of five years. The methodology of data collection is presented. Trends
of data were analyzed and the regression model was used to predict the waste
quantities in the Belgrade port. This data could be utilized as a basis for
the calculation of the equipment capacity for waste selective collection,
treatment and storage. The results presented in this study establish the need
for an organized management system for this type of waste which can be
achieved either by constructing and providing new specialized terminal or by
providing mobile floating facilities and other plants in the Port of Belgrade
for these kinds of services. In addition to the above, the legislative and
organizational strategy of waste management has been explored to complete the
study because the impact of good waste management on environment and
prevention of environmental accidents would be highly beneficial. This study
demonstrated that addressing these issues should be considered at
international as well as national level.
Flexible Grouping as a Means for Classroom Management in a Heterogeneous Classroom
Authors: Rytivaara Anna
Published: March 2011

This article concerns issues of classroom management in heterogeneous classrooms. Although research in the field of learning styles has yielded mixed results, there is a call for information about how they could be used to individualize instruction, especially in primary schools. This article is part of an ethnographic study aiming to examine teacher collaboration in a primary school and it draws strongly on field notes and on interviews with teachers. The intention was to discover how the two teachers in the classroom studied categorized pupils according to the learning styles model they had invented, and how the resulting groups were used for the purposes of classroom management. The study revealed that, first, learning styles seem to work as a grouping method and, second, that flexible grouping can diminish problematic situations traditionally related to heterogeneous classrooms.
Convening a Network within the European Conference on Educational Research: A History of the Social Justice and Intercultural Education Network
Authors: Bhatti Ghazala , Leeman Yvonne
Published: March 2011

The experience of initiating and sustaining a research-based dialogue on social justice and intercultural education in Europe requires both flexibility and focus. This article highlights the challenges facing convenors of one network, who wish to include researchers from diverse backgrounds, while at the same time enhancing the academic quality of the papers presented at the European Conference on Educational Research (ECER). This article presents a brief history of 15 years of networking with a view to discussing some of the main issues which have emerged over the years. The work of Network 7, Social Justice and Intercultural Education, raises significant questions. Is it necessary or desirable to develop a common theoretical language and/or a body of knowledge? And, if so, how can this be done in a scientific world governed by the English language and Anglo-Saxon research traditions? How should differences in research interests and traditions from different parts of Europe be included taking asymmetric power relations into account? Other issues include the incorporation within social justice of discourses on gender, ethnicity, disability and religion. The article defines the interlinked key concepts of social justice and intercultural education which guide the work of the network. A brief history follows, describing the challenges facing the network. These include the issue of language, the discussions during the ECER, the image of the network and the choice of network descriptors. As research is influenced by scientific traditions and cultural, political and financial contexts, it is difficult for the network convenors to influence or direct the research agenda. The article is based on network archives, including documents such as conference programmes; memos; letters; network descriptors and reports; discussions about the selection and acceptance of proposals as recorded in emails and letters; convenors' reflections; and analysis of participants' formal and informal evaluations of network sessions. The issues raised in this article will continue to be debated at the ECER.
The Central Sirtuin 1/p53 Pathway Is Essential for the Orexigenic Action of Ghrelin
Authors: Velásquez Douglas A. , Martínez Gloria , Romero Amparo , Vázquez María J. , Boit Katia D. , Dopeso-Reyes Iria G. , López Miguel , Vidal Anxo , Nogueiras Ruben , Diéguez Carlos
Published: March 2011

OBJECTIVE

Ghrelin is a stomach-derived peptide that increases food intake through the activation of hypothalamic AMP-activated protein kinase (AMPK). However, the molecular mechanisms initiated by the activation of the ghrelin receptor, which in turn lead to AMPK activation, remain unclear. Sirtuin 1 (SIRT1) is a deacetylase activated in response to calorie restriction that acts through the tumor suppressor gene p53. We tested the hypothesis that the central SIRT1/p53 pathway might be mediating the orexigenic action of ghrelin.

RESEARCH DESIGN AND METHODS

SIRT1 inhibitors, such as Ex527 and sirtinol, and AMPK activators, such as AICAR, were administered alongside ghrelin in the brain of rats and mice (wild-type versus p53 knockout [KO]). Their hypothalamic effects on lipid metabolism and changes in transcription factors and neuropeptides were assessed by Western blot and in situ hybridization.

RESULTS

The central pretreatment with Ex527, a potent SIRT1 inhibitor, blunted the ghrelin-induced food intake in rats. Mice lacking p53, a target of SIRT1 action, failed to respond to ghrelin in feeding behavior. Ghrelin failed to phosphorylate hypothalamic AMPK when rats were pretreated with Ex527, as it did in p53 KO mice. It is noteworthy that the hypothalamic SIRT1/p53 pathway seems to be specific for mediating the orexigenic action of ghrelin, because central administration of AICAR, a potent AMPK activator, increased food intake in p53 KO mice. Finally, blockade of the central SIRT1 pathway did not modify ghrelin-induced growth hormone secretion.

CONCLUSIONS

Ghrelin specifically triggers a central SIRT1/p53 pathway that is essential for its orexigenic action, but not for the release of growth hormone.
A Bivariate Genome-Wide Approach to Metabolic Syndrome
Authors: Kraja Aldi T. , Vaidya Dhananjay , Pankow James S. , Goodarzi Mark O. , Assimes Themistocles L. , Kullo Iftikhar J. , Sovio Ulla , Mathias Rasika A. , Sun Yan V. , Franceschini Nora , Absher Devin , Li Guo , Zhang Qunyuan , Feitosa Mary F. , Glazer Nicole L. , Haritunians Talin , Hartikainen Anna-Liisa , Knowles Joshua W. , North Kari E. , Iribarren Carlos , Kral Brian , Yanek Lisa , O’Reilly Paul F. , McCarthy Mark I. , Jaquish Cashell , Couper David J. , Chakravarti Aravinda , Psaty Bruce M. , Becker Lewis C. , Province Michael A. , Boerwinkle Eric , Quertermous Thomas , Palotie Leena , Jarvelin Marjo-Riitta , Becker Diane M. , Kardia Sharon L.R. , Rotter Jerome I. , Chen Yii-Der Ida , Borecki Ingrid B.
Published: March 2011

OBJECTIVE

The metabolic syndrome (MetS) is defined as concomitant disorders of lipid and glucose metabolism, central obesity, and high blood pressure, with an increased risk of type 2 diabetes and cardiovascular disease. This study tests whether common genetic variants with pleiotropic effects account for some of the correlated architecture among five metabolic phenotypes that define MetS.

RESEARCH DESIGN AND METHODS

Seven studies of the STAMPEED consortium, comprising 22,161 participants of European ancestry, underwent genome-wide association analyses of metabolic traits using a panel of ∼2.5 million imputed single nucleotide polymorphisms (SNPs). Phenotypes were defined by the National Cholesterol Education Program (NCEP) criteria for MetS in pairwise combinations. Individuals exceeding the NCEP thresholds for both traits of a pair were considered affected.

RESULTS

Twenty-nine common variants were associated with MetS or a pair of traits. Variants in the genes LPL, CETP, APOA5 (and its cluster), GCKR (and its cluster), LIPC, TRIB1, LOC100128354/MTNR1B, ABCB11, and LOC100129150 were further tested for their association with individual qualitative and quantitative traits. None of the 16 top SNPs (one per gene) associated simultaneously with more than two individual traits. Of them 11 variants showed nominal associations with MetS per se. The effects of 16 top SNPs on the quantitative traits were relatively small, together explaining from ∼9% of the variance in triglycerides, 5.8% of high-density lipoprotein cholesterol, 3.6% of fasting glucose, and 1.4% of systolic blood pressure.

CONCLUSIONS

Qualitative and quantitative pleiotropic tests on pairs of traits indicate that a small portion of the covariation in these traits can be explained by the reported common genetic variants.
Mediastinal lymphangioma and generalized lymphangiomatosis a case report
Authors: Jusufovic Edin , Keser Dragan , Zukic Edin
Published: March 2011

Lymphangioma is a malformation composed of a mass of dilated lymph vessels typically found in the cervical region in children. Mediastinal lymphangioma is a rare condition and accounts for 0.01% to 4.5% of all mediastinal tumors. Only 4 cases of mediastinal lymphangioma involving the heart and great vessels in adults have been described in the available literature. Extremely rarely, lymphangiomas occur as a generalized lymphangiomatosis. We present a case of a woman who coughed up small amounts of fresh blood during 6 months and showed signs of cardiac failure. Several years previously, the patient underwent surgical removal of cystic lymphangiomas from the left ovary, both fallopian tubes and small intestine. A chest radiograph showed an 8-cm round shadow located in the middle lobe. A computerized tomography (CT) scan of the chest with contrast verified the existence of a cyst in the anterior mediastinum. The radiologist suggested that the cyst could have originated in the pericardium. One small cyst also appeared in the projection of the left cardiophrenic sinus. A CT scan with contrast of the patient’s abdomen showed multiple cystic formations in the liver, spleen, kidneys, and left parapelvic region. A fine-needle biopsy of the mediastinal tumor verified the cystic lymphangioma, which was then completely removed surgically. A pathohistological examination confirmed the existence of cystic lymphangioma. The patient was discharged after a period of recovery.
A novel method for detecting light source for digital images forensic
Authors: Roy A. , Mitra S. , Agrawal R.
Published: March 2011

Manipulation in image has been in practice since centuries. These manipulated images are intended to alter facts — facts of ethics, morality, politics, sex, celebrity or chaos. Image forensic science is used to detect these manipulations in a digital image. There are several standard ways to analyze an image for manipulation. Each one has some limitation. Also very rarely any method tried to capitalize on the way image was taken by the camera. We propose a new method that is based on light and its shade as light and shade are the fundamental input resources that may carry all the information of the image. The proposed method measures the direction of light source and uses the light based technique for identification of any intentional partial manipulation in the said digital image. The method is tested for known manipulated images to correctly identify the light sources. The light source of an image is measured in terms of angle. The experimental results show the robustness of the methodology.
A coupled field-circuit model of a 5-phase permanent magnet tubular linear motor
Authors: Tomczuk Bronisław , Waindok Andrzej
Published: March 2011

A coupled field-circuit model of a 5-phase permanent magnet tubular linear motor

A method for modeling of the dynamics characteristics for a 5-phase permanent magnet tubular linear motor (PMTLM) is presented. Its electromagnetic nonlinear field analysis with finite element method (FEM) has been coupled with the circuit model. The calculation model includes the equations for electrical circuits and mechanical quantities as well. They have been obtained using Lagrange's method. The calculated and measured waves of the mover position have been compared for several values of the excitation current. This comparison yields a good agreement. Presented calculation model is very useful in designing and optimization of the PMTLM and in the calculation of the parameters for the control algorithms intended for such a type of actuators.
Transients of electrical and mechanical quantities of a brushless DC motor - computations, measurements
Authors: Ciurys Marek , Dudzikowski Ignacy
Published: March 2011

Transients of electrical and mechanical quantities of a brushless DC motor - computations, measurements

The paper presents a method of computing electrical and mechanical variables of BLDC motors. It takes into account electrical, magnetic and mechanical phenomena in the power supply-converter-BLDC motor-load machine system. The solution to the problem is the so-called circuit-field method. The results determined with the use of time stepping finite element method were used as the parameters of equations of the developed mathematical model. Losses in the motor, losses in transistors and diodes of the converter as well as the actual back EMF waveforms, variable moment of inertia and variable load torque are accounted for. The designed laboratory stand and the test results are presented in the paper. The experimental verification shows the correctness of the developed method, algorithm and program. The developed computational method is universal with respect to different electromechanical systems with cylindrical BLDC motors. It can be applied to electromechanical systems with BLDC motors operating at constant but also variable load torque and moment of inertia.
Investigation of GIC effects on core losses in single phase power transformers
Authors: Mousavi Seyed , Engdahl Göran , Agheb Edris
Published: March 2011

Investigation of GIC effects on core losses in single phase power transformers

This paper presents a method for estimation of core losses in banks of single phase power transformers that are subjected to an injected DC current such as geomagnetically induced currents (GIC). The main procedure of the core loss calculation is to obtain a magnetic flux density waveform in both time and location by using a novel algorithm based on 3D FEM inside the core and then to calculate the loss distribution based on loss separation theory. Also, a simple and effective method is proposed for estimation of losses of asymmetric minor loops by using combination of symmetric loops. The effect of DC biasing on core losses in single phase power transformers is investigated and the sensitivity of core type and material is evaluated. the results shows that DC current biasing could increase core losses up to 40 percent or even more.
The effect of anisotropy in the modified Jiles-Atherton model of static hysteresis
Authors: Chwastek Krzysztof , Szczygłowski Jan
Published: March 2011

The effect of anisotropy in the modified Jiles-Atherton model of static hysteresis

An extension of the modified Jiles-Atherton description to include the effect of anisotropy is presented. Anisotropy is related to the value of the angular momentum quantum numberJ, which affects the form of the Brillouin function used to describe the anhysteretic magnetization. Moreover the shape of magnetization dependentR(m)function is influenced by the choice of theJvalue.
The accuracy of loss prediction in magnetic materials
Authors: Szczygłowski Jan , Kopciuszewski Paweł , Chwastek Krzysztof , Najgebauer Mariusz , Wilczyński Wiesław
Published: March 2011

The accuracy of loss prediction in magnetic materials

The paper presents a formula useful for prediction of loss density in soft magnetic materials, which takes into account multi-scale energy dissipation. A universal phenomenologicalP(Bm, f) relationship is used for loss prediction in chosen soft magnetic materials. A bootstrap method is used to generate additional data points, what makes it possible to increase the prediction accuracy. A substantial accuracy improvement for estimated model parameters is obtained in the case, when additional data points are taken into account. The proposed description could be useful both for device designers and researchers involved in computational electromagnetism.
Application of higher order forms for the description of electromechanical energy converters
Authors: Sobczyk Tadeusz
Published: March 2011

Application of higher order forms for the description of electromechanical energy converters

The purpose of that paper is to develop of unified equations of electromechanical energy converters accounting for the magnetic non-linearity of the main magnetic circuit of a converter. The concept of applying higher order forms of winding currents for the description of the co-energy function is introduced in order to derive the structure of converter equations via mathematical analysis. Also, another concept of equivalent magnetizing currents is applied to determine the higher order forms for selected converters designs. The structure of circuital equations for converters with multiple windings has been unified by means of the introduction of matrices of dynamic and nonlinear inductances following the higher order forms of the co-energy function.
Influence of commutation conditions on steady states in matrix converter
Authors: Borkowski Dariusz , Sobczyk Tadeusz
Published: March 2011

Influence of commutation conditions on steady states in matrix converter

The paper investigates a significant influence of transients on steady states in a matrix converter with the one-periodic control strategy. Proposed controller can be used as an interconnection device within a power system for a power flow control. However, the presence of inductances in external systems has the significant influence on steady state of a matrix converter operation. The special current injection method has been developed to ensure a proper operation of a matrix converter. Presented analysis of steady states is carried out in a frequency domain using the harmonic balance method. Obtained numerical results, which are confirmed by a time domain analysis, prove the effectiveness of the proposed method.
Simplified isoperibol calorimetry for thermal testing of dielectric and conducting materials
Authors: Moroń Leszek , Żyłka Paweł
Published: March 2011

Simplified isoperibol calorimetry for thermal testing of dielectric and conducting materials

A simplified isoperibol calorimetry method for measuring specific heat in solids is described. Taking advantage of the classical Nernst dependency the specific heat is calculated from time-domain temperature curves registered for a sample forced heating and natural cooling phase. In order to improve accuracy of the measurements a correction factor, taking into account the heat transferred to the surrounding, is introduced along with a procedure of statistical elimination of unavoidable measurement deviations. The method is implemented in a simple and straightforward measuring system involving no vacuum calorimeter. The method is applicable for quick and routine specific heat measurements performed on small solid dielectric or metallic specimens at near-room temperature. Test results of various materials used commonly in electrical engineering are demonstrated and discussed as well as comparison to drop calorimetry and differential scanning calorimetry reference measurements is included. The overall repeatability of the test method and the simplified apparatus is estimated as not worse than 2.6%.
Morphometric analysis of some populations of lymnocardiid species (Mollusca: Bivalvia) from Razelm Lake Complex (Romania)
Authors: Popa Oana , Iorgu Elena , Kelemen Beatrice , Murariu Dumitru , Popa Luis
Published: March 2011

Morphometric analysis of some populations of lymnocardiid species (Mollusca: Bivalvia) from Razelm Lake Complex (Romania)

In this paper we report the morphometric analysis of some populations of Lymnocardiid species from the lakes Razelm and Goloviţa. We used three measurements ratios to perform a discriminant analysis and a multivariate analysis of variance (MANOVA), in order to compare the species Hypanis colorata vs. Hypanis angusticostata in the two lakes, H. colorata in Razelm vs. Goloviţa, and H. angusticostata in Razelm vs. Goloviţa. From this analysis we concluded that the multivariate means of the morphological variables used in this study were highly significantly different (p=3.2e-05) between the two species. Concerning the geographical variability, in both species, the analysis showed no significant difference between the populations in the two investigated lakes. We also determined from a fitting curve analysis, that the growth pattern of both species shows length-height isometry and width-length and width-height negative allometry.
The freshwater Mollusca fauna from Banat (Romania)
Authors: Sîrbu Ioan , Sîrbu Monica , Benedek Ana
Published: March 2011

The freshwater Mollusca fauna from Banat (Romania)

The freshwater molluscs fauna from Banat comprises 61 species (41 of gastropods and 20 of bivalves). 10 species were newly identified in this area by the authors. This paper's aim is to establish the systematical and chorological catalogue of this fauna, to highlight the most characteristic and significant elements, the threats represented by human impact on the area's waters and their molluscs communities.
Some remarks on the family Tanzanapseudidae, with the description of three new species and the validation of the genus Acanthapseudes Roman, 1976 (Crustacea: Tanaidacea: Apseudomorpha)
Authors: Guţu Modest
Published: March 2011

Some remarks on the family Tanzanapseudidae, with the description of three new species and the validation of the genus Acanthapseudes Roman, 1976 (Crustacea: Tanaidacea: Apseudomorpha)

Two new species of the genus Tanzanapseudes Băcescu, 1975 (T. bacescui n. sp. and T. mirificus n. sp.) and one belonging to the genus Acanthapseudes Roman, 1976 (A. hansgeorgmuelleri n. sp.) from the islands Sri Lanka and Mauritius (Indian Ocean) are described and illustrated, as a result of the synonymization invalidation of the genus Acanthapseudes with Tanzanapseudes. At the same time, some morphological data on a doubtful species of the genus Tanzanapseudes (from Mozambique Channel) are presented, and manca I and II stages in T. mirificus n. sp. and manca I in A. hansgeorgmuelleri n. sp. are described, unknown in tanzanapseudids up to now. Also, new diagnoses (of the family Tanzanapseudidae and of the two genera), as well as the identification key of the genera and species of the above-mentioned family are presented.
Checklist of springtails (Collembola) from the Republic of Moldova
Authors: Buşmachiu Galina
Published: March 2011

Checklist of springtails (Collembola) from the Republic of Moldova

The checklist of Collembola from the Republic of Moldova including 223 species is presented. The list is based on literature sources and personal collecting.
Faunistic data on some true bugs species (Insecta: Heteroptera) from West Turkey [Results of the "Taurus" - 2005 and "Focida" - 2006 expeditions]
Authors: Şerban Cecilia
Published: March 2011

Faunistic data on some true bugs species (Insecta: Heteroptera) from West Turkey [Results of the "Taurus" - 2005 and "Focida" - 2006 expeditions]

The paper presents a list of Heteroptera species (except Miroidea) collected during the scientific expeditions carried out in Western Turkey between 2005-2006 by "Grigore Antipa" National Museum of Natural History (Bucharest) and NGO - "Oceanic Club" Society of Oceanographical Exploration and Protection of the Marine Environment of Constanţa. Out of 516 true bug specimens, I identified 73 species grouped in 56 genera, belonging to 4 infraorders and 12 families. Tarisa flavescens is new record for Turkey.
Şura Mare cave (Romania) - the most important known hibernating roost for Pipistrellus pygmaeus Leach, 1825 (Chiroptera: Vespertilionidae)
Authors: Murariu Dumitru , Gheorghiu Victor
Published: March 2011

Şura Mare cave (Romania) - the most important known hibernating roost for Pipistrellus pygmaeus Leach, 1825 (Chiroptera: Vespertilionidae)

The Sura Mare cave from Romania is one of the largest roost for hibernating colonies of bats with more than 40,000 individuals. Pipistrellus pipistrellus and P. pygmaeus are prevalent species with more than 34,000 individuals in mixed colonies. Other 6 bat species are less represented (e.g. Rhinolophus ferrumequinum only 500 individuals) but Miniopterus schreibersii's colony counts 3,500 individuals. From the total of 8 identified bat species, 5 are a priority according to the European Union legislation: Rhinolophus ferrumequinum, Myotis myotis, M. oxygnathus, Barbastella barbastellus and Miniopterus schreibersii.
Bat geographic distribution North of the Carpathians
Authors: Wołoszyn Bronisław , Pereswiet-Soltan Andrea
Published: March 2011

Bat geographic distribution North of the Carpathians

Recent bat fauna in the area North of the Carpathians (Poland) consist of 25 species (2 Rhinolophidae and 23 Vespertilionidae). 25 bat species recorded so far from Poland can be divided into three groups: 1. Species limited to the southern Poland, occurred in the Polish Segment of the Carpathians (Beskidy Mts.), the Sudety Mts., and the Kraków-Częstochowa Upland; 2. Species with North-eastern limit of the distribution in the West and Central Poland, for example Myotis myotis; 3. Species with unlimited distribution on Polish territory, occurred also in the North-eastern Poland.
Terrestrial vertebrates of Dobrogea - Romania and Bulgaria
Authors: Murariu Dumitru , Chişamera Gabriel , Petrescu Angela , Atanasova Ivanka , Raykov Ivaylo
Published: March 2011

Terrestrial vertebrates of Dobrogea - Romania and Bulgaria

The authors report the state of the terrestrial vertebrates of Romanian and Bulgarian Dobrogea. Five amphibian species, eight of reptiles, 159 of birds and 39 mammals species were inventoried. Some of them are characteristic to the steppe areas, in which Dobrogea is included, and others (as amphibians) have a limited distribution, around water flows, pools and lakes. Some of the observed or collected species have populations which can be compared in the two parts of Dobrogea, while the others (e.g. Crocidura suaveolens, Mesocricetus newtoni, Microtus arvalis) have populations more numerous in the Bulgarian Dobrogea, this thing indicating that there are several undamaged habitats and a low anthropic pressure than in the Romanian one.
Alien invasive species at the Romanian Black Sea coast - Present and perspectives
Authors: Skolka Marius , Preda Cristina
Published: March 2011

Alien invasive species at the Romanian Black Sea coast - Present and perspectives

Using literature data and personal field observations we present an overview of aquatic animal alien invasive species at the Romanian Black Sea coast, including freshwater species encountered in this area. We discuss records, pathways of introduction, origin and impact on native communities for some of these alien invasive species. In perspective, we draw attention on the potential of other alien species to become invasive in the study area.
Dynamics of Asio otus L., 1758 (Aves: Strigiformes) winter-spring trophic regime in Western Plain (Romania)
Authors: Benedek Ana , Sîrbu Ioan
Published: March 2011

Dynamics of Asio otus L., 1758 (Aves: Strigiformes) winter-spring trophic regime in Western Plain (Romania)

The trophic regime of Asio otus is dominated by Microtus arvalis. In both areas the proportion of this species in the long-eared owl's food presents an important seasonal variation. In winter it moves usually through tunnels under the snow, thus being less frequently hunted. When the main prey is scarce, alternative food resources are exploited, in these areas mice, which become dominant as a group. A significant variation is recorded also by the mean biomass of preys of Asio otus from Satu Mare. The average body mass increases with one third from January to March, when the efficiency of hunt is maximum.
Ecological aspects of bat hibernacula in temperate climate zone of Central Europe
Authors: Kłys Grzegorz , Wołoszyn Bronisław
Published: March 2011

Ecological aspects of bat hibernacula in temperate climate zone of Central Europe

In temperate climate zone, undergrounds (caves) are the main place for bat hibernation. It is possible to distinguish three kinds of usage of caves by bats: caves used as a hibernaculum, where bats spend the winter period, caves used as shelters for reproductive colonies during the summer period, and caves used as temporary shelters during transitional period (spring and fall) and also as places for food. Caves used as hibernaculum must offer a suitable microclimate for bats. Several important physical factors decide on the selection by bats of a refugee for a period of hibernation. The hibernaculum should have a zone of total darkness. During hibernation bats pay special attention to air circulation, humidity and temperature. These factors are also of significance in forming the microclimate condition inside cave system. Throughout the influence above mentioned factors, a connection between microclimatic condition and topoclimate appears in the cave system and, as a consequence, a refugioclimate forms.
Floristic diversity and conservation strategies in cold desert of western Himalaya, India
Authors: Srivastava Sunil Kumar
Published: March 2011

The rich flora of cold desert constitutes an incredible store house of plant genetic resources that contribute not only to the livelihoods of enormous number of forest dwelling but also to the various pharmaceuticals industry. The plant wealth of Ladakh in Jammu and Kashmir, Lahaul-Spiti in Himachal Pradesh and Nelang valley in Uttarakhand falls in cold desert region of North-West Himalaya. The floristic documentation of this area represents ca 1405 species, 490 genera under 98 families of flowering plants. A large number of species growing in this area are of medicinal and economic value and used by local inhabitants for curing their ailments. Floristic analysis, brief account of physiography, vegetation types and adaptations in the plants for their survival, endemism, threatened taxa, medicinal and economic plants have been discussed along with the threats and conservation strategies. Key-words: Floristic; Diversity; Conservation; Cold Desert; India DOI: 10.3126/botor.v7i0.4369Botanica Orientalis – Journal of Plant Science (2010) 7: 18-25
Variation in the active constituent contents in Centella asiatica grown in different habitats in Nepal
Authors: Devkota Anjana , Acqua Stefano Dall' , Jha Pramod Kumar , Innocenti Gabbriel
Published: March 2011

Centella asiatica is an important medicinal plant of subtropical to tropical region. It grows widely, in different habitats. In Nepal, it is distributed at an altitudinal range of 96-2200 m above sea level. A comparative quantitative analysis of chemical constituents in Centella asiatica samples collected from three different habitats in Nepal was carried out by HPLC to evaluate the variability in the important constituents. There was marked variability in asiaticoside, asiatic acid and quercetin 3-O-glucuronide content among the samples collected from different habitats. Samples collected from open agricultural land showed the highest asiaticoside (1.91%), asiatic acid (0.13%) and quercetin 3-O-glucuronide (0.35%) content. Therefore, open land is preferable for plantation of this species for high yield of secondary metabolites. Key-words: Asiaticoside; asiatic acid; Centella asiatica; HPLC; medicinal plants; quercetin 3-O-glucuronide. DOI: 10.3126/botor.v7i0.4372Botanica Orientalis – Journal of Plant Science (2010) 7: 43-47