bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Analysis of the Performance of a Solar Driven Micro-Inverter Using Single Ended Primary Inductance Converter Topology
Authors: Radhakrishnan G. , Rani Sheeba S. , Ramya K. C. , Jeylani Maideen Abdul Kadher A. , Gomathy V.
Published: April 2019

In typical solar power installations, multiple modules are connected to the grid through a single high-power inverter. However, an alternative approach is to connect each solar module directly to the grid through a micro-inverter. This approach makes the system robust to single module
failures and results in better power tracking. PV based cower conditioning system need a high-efficiency dc–dc converter capable of regulation over a wide input voltage range for Maximum Power Point Tracking (MPPT) and a high-efficiency micro-inverter. To diminish the ground leakage
currents, also to use a high-efficiency system, the proposed concept is required for this micro-inverter to provide galvanic isolation between the PV module and the inverter. This concept involves the design of a micro-inverter topology which includes design of Single Ended Primary Inductance
Converter (SEPIC) dc/dc converter, isolated resonant inverter and a cyclo-converter. The SEPIC converter topology yields high efficiency through constant voltage MPPT algorithm. The Resonant inverter topology produces efficient output through low circulating currents, Zero Voltage Switching
(ZVS), low-current switching of the primary side devices, and Zero Current Switching (ZCS) of the output diodes. This Resonant inverter topology is also able to provide voltage regulation through basic fixed-frequency Pulse Width Modulated (PWM) control. The features of proposed system can
able to achieve w the simple addition of a secondary-side bidirectional ac switch to the isolated series resonant converter.
DoDo Approach: An Automated Tool for Programming Evaluation and Progress Monitoring for Student Skills
Authors: Venkatesh S. , Thangaraj P.
Published: April 2019

Chalk and talk methods of teaching have been effective till the technological expansion has rooted up for student community. Finding some way to be distracted in a classroom, teaching and learning strategies needed an efficient approach for sharing/transfer of knowledge. An approach
reported to be dynamic in design and supportive for 24/7 discussions with measures to monitor the progress periodically is proposed in this paper. DoDo takes an innovative concept of brute force method to prevent the missing of important points during a session. Exhaustion by mentioning every
other standard in a concept of discussion enhances the level of learning. Accepting to the fact that not a 100 percent is prepared for sessions nor delivered in a classroom provides loopholes and justification for knowledge not to be shared. Assignments, tests and evaluations are supposed
to identify the progress of students' skills rather rank them accordingly and categorize them. DoDo ensures the deliverance of concepts to every student irrespective of his/understanding capability, tests them with easier methodologies, provides a ground for practices and monitor them every
now and then with a periodical report to explain the headway of indulgence.
Climate Changes Prediction Using Simple Linear Regression
Authors: Sreehari E. , Ghantasala Pradeep G. S.
Published: April 2019

The rise in global temperatures, frequent natural disasters and rising sea levels, reducing Polar Regions have made the problem of understanding and predicting these global climate phenomena. Prediction is a matter of prime importance and they are run as computer simulations to predict
climate variables such as temperature, precipitation, rainfall and etc. The agricultural country called India in which 60% of the people depending upon the agriculture. Rain fall prediction is the most important task for predicting early prediction of rainfall May helps to peasant's as well
as for the people because most of the people in India can be depends upon the agriculture. The paper represents simple linear regression technique for the early prediction of rainfall. It can helps to farmers for taking appropriate decisions on crop yielding. As usually at the same time there
may be a scope to analyze the occurrence of floods or droughts. The simple linear regression analysis methodology applied on the dataset collected over six years of Coonor in Nilagris district from Tamil Nadu state. The experiment and our simple linear regression methodology exploit the appropriate
results for the rain fall.
Automated Diagnosis System for Alzheimer Disease Using Features Selected by Artificial Bee Colony
Authors: Karpagam Shunmuga N. , Raghavan Srinivasa
Published: April 2019

Alzheimer's disease (AD) is perhaps the most common of the forms of dementia that affects the elderly all the world over. The feature selection techniques are often used in the domains in which various features and very few data samples are available. In this work, the image of the
brain is classified as either Alzheimer, the MCI or normal. The images features are extracted by the SPM12, and their best features will be chosen by using the techniques of feature selection like the Information Gain (IG), the Maximal Relevance and the Minimal Redundancy (MRMR), along with
the proposed Artificial Bee Colony (ABC). The ABC is one algorithm of optimization that has taken its inspiration from the search process of honey bees for the best sources of food. The features are classified using classifiers like Logit Boost and the cascaded classifier.
Compact Ultra-Wideband Slot Antenna with Dual Band Rejection by Using H-Shape Notch
Authors: Thivakaran T. K. , Sivabalan A.
Published: April 2019

The main objective is to design a dual band rejection micro strip patch antenna. In this antenna, H-shaped slots are made in the patch to achieve notched characteristics at two licensed band employed for Wimax and WLAN band. The above mentioned frequency ranges are licensed for WLAN
and satellite communication applications. These antennas maintain the Omni-directional radiation patterns and are mostly suited for ultra wide band applications. For wide band operation, the shape of patch has been altered to octagonal just by chamfering the corners of the rectangular patch.
The antenna parameters like radiation patterns, VSWR, reflection loss have been described clearly in this section. Radar applications, terrestrial networking and communication, space communications are some of the applications in this ultra wide band frequency range.
T Structured Semantic Weight Relationship Algorithm Combined with Decision Trees for Data Extraction
Authors: Kumar Saravana C. S. , Amudhavalli P. , Santhosh R. , Kalaiarasan C.
Published: April 2019

In Semantic Web Mining extracting the relevant data from web is the main objective. With the increase in the complexity of the data involved the focus is to achieve better accuracy by extracting the required information. In Semantic web mining the primary input is the user query but
the accuracy is based on the domain classification of the data extracted. To achieve accuracy higher a new approach has been proposed where the algorithm same name as article titled maintains a Semantic structure combined with the decision trees. From the training set each word has been tokenized
and the relationship between them has been established involving cosine similarity weight as well as to the possibility terms of the same word. Cosine Similarity is calculated not only between the words but also established between the group of the training sentences. The paper explains in
detail regarding grouping of training sentences and establishing the weight between them using our proposed approach.
A Noval Improved Variable Step-Size Incremental Resistance Maximum Power Point Tracking Controller for Photo Voltaic System Under Partial Shading Condition
Authors: Geethamani R. , Pavithra C. , Niranjana B. , Gomathy V. , Chitra P.
Published: April 2019

A Variable step size Incremental resistance algorithm for PV system was designed for maximum power point tracking. The outputs are generated with help of MATLAB/SIMLUNK. The performance of the PV system for partial shading condition was observed. The output for the system was found
to be more efficient and attains stability much faster than any other controller. The power output can be controlled by varying the scaling factor.
An Enhanced Peak to Average Power Ratio Reduction Scheme for Interleaved and Sub-Band Orthogonal Frequency-Division Multiple Access Frameworks with Low Complexity
Authors: Palani K. , Jagadeesan D. , Jothikumar R. , Susi S.
Published: April 2019

Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier transmission technique which has the major drawback namely Peak to Average Power Ratio (PAPR). The high PAPR influences the efficiency of the power amplifier. The Selected Level Mapping (SLM) gives reduced PAPR contrasted
with different strategies but the complexity is high due to the necessity of various Inverse Fast Fourier Transform (IFFTs). With the end goal to reduce the complexity, the proposed design requires only one IFFT, the candidate signals are produced by cyclic shifting the original time domain
signal then multiplying with the distinctive genuine positive numbers. At that point the candidate with most minimal PAPR is chosen for transmission.
Enhanced Biometric Based Automated Teller Machine Authenticate Security System Using Low Power Microcontroller
Authors: Thivakaran T. K. , Sasikumar D.
Published: April 2019

Information and communication technology achieved mass improvement on ATMs cyber-security but there is a strong need to strengthen all parts of operation. ATM skimmers are card readers that collect the data from magnetic card stripe that is attached to the real payment terminals; especially
criminals can create cloned cards to steal money from the bank account. After these also we think that ATM is the safest place. But, nowadays in ATM, robbery happens easily by damaging the system for money. In this paper we bring an idea about biometric based system to enhance security. There
is signal processing which alerts the police and gives information to bank.
Stability Assessment on Doubly Fed Induction Generator (DFIG) Wind Turbine Micro Grid Power System
Authors: Hannoon Naeem M. S. , Vijayakumar V. , Vengatesan K. , Hidayat Nabil
Published: April 2019

As of late, expanding interest of renewable energy and consumption of non-renewable energy source have prompted developing advancement of renewable energy technology, for example, wind energy. Wind energy has turned out to be one of the reliable sources of renewable energy, which requests
extra transmission capacity and better methods for sustaining system reliability. As of now, doubly fed induction generator wind turbine is the most well-known wind turbine. This paper focuses on DFIG wind farm design using MATLAB/SIMULINK and also investigates the issues of the system stability
of the DFIG wind turbine micro grid power system. This analysis includes the changes of voltage, current, real power and reactive power based on various conditions of the power system.
Automatic Prostate Lesions Detection on MR Images Based on the Ising Model
Authors: Reis Artur Bernardo Silva , Silva Aristófanes Corrêa , de Paiva Anselmo Cardoso , Gattass Marcelo
Published: April 2019

Prostate cancer is the second most prevalent type of cancer in the male population worldwide. Prostate imaging tests have adopted for the prevention, diagnosis, and treatment. It is known that early detection increases the chances of an effective treatment, improving the prognosis of
the disease. This paper proposes an automatic methodology for prostate lesions detection. It consists of the following steps: Extracting candidates for lesions with Wolff algorithm; feature extraction using the Ising model measures and finally the uses support vector machine in the classification
of a lesion or healthy tissue. The methodology was validated using a set of 28 exams containing the lesion markings and obtained a sensitivity of 95.92%, specificity of 93.89% and accuracy of 94.16%. These are promising since they were more significant than other methods compared.
Antimicrobial, Cytotoxic Activity of the Syzygium aromaticum Essential Oil, Molecular Docking and Dynamics Molecular Studies of Its Major Chemical Constituent
Authors: de Oliveira Mozaniel Santana , da Cruz Jorddy Neves , Mitre Geovanni Pereira , da Costa Wanessa Almeida , Kataoka Maria Sueli da Silva , Silva Sebastião Gomes , Alves Ana Cláudia Braga Amoras , Pinheiro João de Jesus Viana , Silva Silvia Elena Marques , de Menezes Sílvio Augusto Fernandes , Menezes Tatiany Oliveira de Alencar , Neto Antônio Maia de Jesus Chaves , Junior Raul Nunes de Carvalho
Published: April 2019

The objective of the present work was to analyze the cytotoxic, antimicrobial activity and the action mechanism of the major component in of the Syzygium aromaticum essential oil obtained by supercritical CO2. In this work, gingival fibroblasts were exposed to the
essential oil in different concentrations for one hour: 5 μL/ml, 7.5 μL/ml and 10 μL/ml. Culture medium was used as control. Cytotoxicity analysis was performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT®) method. The susceptibility
was evaluated on three microorganisms Candida albicans, Escherichia coli and Staphylococcus aureus. The statistical analyses showed significant difference in cell viability for the concentration of 10 μL/mL, as compared to the control group. As a result, the plant extract
had no cytotoxicity at concentrations below 10 μL/mL in human gingival fibroblasts. The interaction mode of eugenol, the major compound and main component responsible for the biological activity of the essential oil was evaluated. The molecular docking of eugenol with important proteins
of the metabolic pathway of the microorganisms C. albicans, E. coli and S. aureus were performed. The results demonstrated that the compound is capable of interacting with catalytic residues of the enzymes and forming an energetically favorable system with such proteins. The
results of binding free energy obtained demonstrate this capacity. For the eugenolN-myristoyltransferase (C. albicans) system, the value of ΔGbind was –19.01 kcal/mol, for Enoyl reductase (E. Coli) ΔGbind was equal to –11.31
kcal/mol and for SarA (S. aureus) ΔGbind was –13.58 kcal/mol.
Survey on Optimization Algorithms Used for Feature Selection Techniques in Web Page Classification
Authors: Ramanujam K. S. , David K.
Published: April 2019

Web page classification refers to one of the significant research are in the web mining domain. Enormous quantity of data existing in the web demands the essential development of various effective and robust techniques to undergo web mining task that involves the process to categorizing
the web page based on the data labels. It also includes various other tasks such as web crawling, analysis of web links and contextual advertising process. Existing machine learning and data mining techniques are being efficiently used for various web mining processes which include classification
of web pages. Using of multiple classifier techniques are most promising research area while considering machine learning that works on the base of merging various classifiers with difference in base classifier and/or dataset distribution. With this several classification models are constructed
that is highly robust in nature. This review paper, comparison has been done between FA, PSO, ACO, GA and IWT, to evaluate best fit algorithm for classifying web pages.
Auditory Brainstem Implantation after Unsuccessful Cochlear Implantation of Children with Clinical Diagnosis of Cochlear Nerve Deficiency
Authors: Colletti Liliana , Wilkinson Eric P. , Colletti Vittorio
Published: April 2019

Objectives

We compared the perceptual auditory abilities of 21 children with suspected cochlear nerve deficiency (CND) and a surgically verified absent cochlear nerve (CN) who first underwent cochlear implantation (CI) and subsequently underwent auditory brainstem implantation (ABI).

Methods

In this retrospective cohort study, from 2000 to 2011, 21 children initially underwent CI at an outside institution and failed to progress in their perceptual auditory abilities. Before CI, all of the children had severe to profound sensorineural hearing loss and a diagnosis of CND. Magnetic resonance imaging (MRI) documented an absent CN in 13 children and a small CN in 8 children. We performed explantation of the cochlear implant and simultaneous ABI on the same side. We performed MRI if no previous MRI results were available. All surgical videos were reviewed to determine the presence or absence of the CN. Measures of the patients’ perceptual auditory abilities obtained after CI and after ABI were converted to the Category of Auditory Performance (CAP) scale.

Results

At surgery, all patients demonstrated an absent CN. After CI, all patients had a CAP score of 2 or less (mean, 0.52 ± 0.68). After ABI, all patients had a CAP score of 2 or more (mean, 4.33 ± 1.68); the improvement was statistically significant (p < 0.001). The complication rates were similar for CI and ABI.

Conclusions

In this cohort of patients who had poor performance after CI, ABI achieved significantly improved performance as measured by the CAP and was shown to successfully rehabilitate hearing. Cases of a small CN may in reality represent an absent CN. Although this cohort was selected from patients with failed CI, the results have implications for the selection of device for patients with CND, in that ABI is a potential alternative to CI in select cases. In patients who fail to progress with intensive rehabilitation with CI or who have no progression in evoked auditory brainstem response, ABI must be considered early.
Analysis of heat transfer characteristics in textiles and factors affecting thermal properties by modeling
Authors: Shen Hua , Xie Kaifang , Shi Haoxuan , Yan Xiaofei , Tu Lexi , Xu Yanfang , Wang Jilong
Published: April 2019

The heat transmission through a fabric during the measurement of thermal resistance was simulated by a novel heterogeneous model that was constructed according to the structure of ThermolabII Tester KES-F7. In this model, the heat transmissions along the longitudinal and transverse directions of yarn were treated independently. The material constants of fabrics, such as mass density, specific heat, thermal conductivity and thickness, were used as parameters for simulation in this fabric model. The validity of this model was then confirmed by the high consistency between the heat flux obtained from experiment and simulation, with the average difference ratio lower than 5%. The simulation results suggested that the guard area could effectively reduce the horizontal heat leakage from the test plate when the experimental fabric was thin. Only less than 8% of heat leaked in the one-layer case, while the leakage was significantly aggravated when more layers of fabric were stacked, resulting in the considerably lower thermal insulation achieved in both experiment and simulation compared with that in real fabrics. The temperature distribution in the model also implied that the longitudinal and transverse thermal conductivity of yarn exerted great effect on the heat leakage during the measurement. Moreover, for multilayers consisting of different fabrics, the laying sequence could obviously influence the heat leakage and, consequently, change the obtained thermal resistance.
Fault tolerant control with disturbance estimator for a class of linear parameter varying systems subject to time-varying fault
Authors: Liu Chunsheng , Lu Ke , Sun Jingliang , Dai Jiao
Published: April 2019

This paper proposes a sliding-mode control (SMC) scheme for a class of linear parameter varying (LPV) systems subject to a loss of control effectiveness and external disturbance. The LPV model is transformed into the non-LPV model representation. The updating law for unknown time-varying fault and the disturbance estimator are designed. The novel sliding-mode fault tolerant control (FTC) law is presented by using estimated fault and estimated disturbance to compensate the effects of faults in both cases: the known and the partial known system matrices. The stability analysis of closed-loop system is performed on the Lyapunov theory. The main advantage of the proposed method is to circumvent solving on-line parameter-dependent nonlinear matrix inequalities, also to adapt to the changes of unknown parameter. The feasibility of the approach is illustrated by means of the simulation examples.
Further Analysis of the Immediate and Subsequent Effect of RIRD on Vocal Stereotypy
Authors: Sivaraman Maithri , Rapp John T.
Published: April 2019

Although numerous studies have shown that response interruption and redirection (RIRD) can decrease vocal stereotypy displayed by children with autism spectrum disorder, relatively few have evaluated the subsequent effects of RIRD. We evaluated the immediate (when a change agent implemented RIRD) and subsequent (after a change agent discontinued RIRD) effects of RIRD on two participants’ vocal stereotypy using a nonconcurrent multiple baseline design with an embedded reversal design combined with a multiple schedule. As a part of the analysis, we conducted the fourth component 25 min after the third component. In addition, we compared the effects of RIRD with 5-min and 20-min components on both participants’ vocal stereotypy. Results show that (a) RIRD during either 5-min or 20-min components decreased each participant’s immediate engagement in vocal stereotypy, (b) only RIRD during 20-min components decreased each participant’s subsequent engagement in vocal stereotypy relative to the no intervention component, and (c) the subsequent effects of RIRD did not extend into the fourth component for either participant.
Participation in Social Skills Therapy is Associated With Enhanced Recall Memory by Children With Down Syndrome: An Exploratory Study
Authors: Milojevich Helen M. , Slonecker Emily M. , Lukowski Angela F.
Published: April 2019

Participation in social skills therapy (SST) facilitates cognitive functioning in children with developmental disabilities. The present pilot study examined whether participation in SST was associated with enhanced encoding and 1-month delayed recall in children with Down syndrome (DS). Children were presented with novel three-step event sequences in an elicited imitation procedure. Immediate imitation was permitted as an index of encoding; long-term memory was assessed 1 month later. Parents completed questionnaires inquiring about children’s participation in SST. Participation in SST was associated with enhanced encoding of temporal order information and 1-month delayed recall of individual target actions. In addition, encoding mediated the relation between group and 1-month delayed recall. The conducted research indicates that involvement in SST may be beneficial for children with DS despite their noted strengths in imitation and social learning. As such, additional experimental work is warranted to determine causality.
The Clinical Reliability of Vestibular Evoked Myogenic Potentials
Authors: Bush Matthew L. , Jones Raleigh O. , Shinn Jennifer B.
Published: April 2019

Vestibular evoked myogenic potential (VEMP) testing has gained popularity as a diagnostic modality in otolaryngology and audiology. To maximize the utility of this test, examiners need the availability of ideal test settings and reliable norms. We conducted a prospective study of 8 subjects with no history of neurotologic symptoms to examine the test-retest consistency of VEMP testing and to analyze the impact of stimulus type and muscle tension monitoring. All subjects underwent VEMP testing with two stimuli: a 500-Hz tone and a click. With each stimulus, testing was completed with and without monitoring of sternocleidomastoid muscle tension. All subjects participated in an initial testing session and then returned for a repeat testing session 2 to 4 weeks later. We measured the amplitude of primary waveforms P13 (first positive peak) and N23 (first negative peak) and analyzed the reliability and reproducibility of the mean amplitude asymmetry of these VEMP peaks. The P13 component of the VEMP (specificity: 86.25%) demonstrated a more stable amplitude than did the N23 component (specificity: 70.50%). Therefore, our statistical analysis of the effect of stimulus type and muscle tension monitoring on test-retest reliability was limited to the P13 waveform. We found that neither the type of stimulus nor the presence or absence of muscle tension monitoring had any statistically significant effect on amplitude asymmetry. We concluded that in VEMP testing, the P13 component was more specific than the N23 component in identifying normal subjects and that the P13 component provided consistent results across test sessions, regardless of the type of stimulus or the presence or absence of muscle tension monitoring.
Perceptual, Aerodynamic, and Acoustic Characteristics of Voice Changes in Patients with Laryngopharyngeal Reflux Disease
Authors: Lechien Jérôme R. , Khalife Mohamad , Huet Kathy , Finck Camille , Bousard Laura , Delvaux Véronique , Piccaluga Myriam , Harmegnies Bernard , Saussez Sven
Published: April 2019

Laryngopharyngeal reflux (LPR) is an inflammatory condition suspected to be associated with dysphonia. In this study, we investigated multidimensional perceptual, aerodynamic, and acoustic voice changes in patients with clinically diagnosed LPR compared to healthy participants. We prospectively included 80 outpatients with Reflux Finding Score (RFS) >7 and Reflux Symptom Index (RSI) >13 from September 2013 to April 2016 and we compared clinical and voice quality assessments of these patients with 80 healthy participants. Statistically significant differences were found between groups with regard to Voice Handicap Index, perceptual voice quality (grades of dysphonia, roughness, strain, breathiness, asthenia, and instability), phonatory quotient, percentage jitter, percentage shimmer, peak-to-peak amplitude variation, standard deviation of fundamental frequency, and noise to harmonic ratio. Granulation score of RFS was found to affect the highest number of acoustic parameters. We did not identify significant correlation between vocal fold edema and objective voice quality measurements. This study supports that patients with LPR have significant deterioration of both subjective and objective voice quality compared to healthy participants.
Body Image Disturbance in Surgically Treated Head and Neck Cancer Patients: A Patient‐Centered Approach
Authors: Ellis Mark A. , Sterba Katherine R. , Day Terry A. , Marsh Courtney H. , Maurer Stacy , Hill Elizabeth G. , Graboyes Evan M.
Published: April 2019

Objective

To promote patient‐centered oncology care through an in‐depth analysis of the patient experience of body image disturbance (BID) following surgery for head and neck cancer (HNC).

Study Design

Qualitative methods approach using semistructured key informant interviews.

Setting

Academic medical center.

Subjects and Methods

Participants with surgically treated HNC underwent semistructured key informant interviews and completed a sociodemographic survey. Recorded interviews were transcribed, coded, and analyzed using template analysis to inform creation of a conceptual model.

Results

Twenty‐two participants with surgically treated HNC were included, of whom 16 had advanced stage disease and 15 underwent free tissue transfer. Five key themes emerged characterizing the participants’ lived experiences with BID following HNC treatment: personal dissatisfaction with appearance, other‐oriented appearance concerns, appearance concealment, distress with functional impairments, and social avoidance. The participant’s perceived BID severity was modified by preoperative patient expectations, social support, and positive rational acceptance. These 5 key themes and 3 experiential modifiers form the basis of a novel, patient‐centered conceptual model for understanding BID in HNC survivors.

Conclusion

A patient‐centered approach to HNC care reveals that dissatisfaction with appearance, other‐oriented appearance concerns, appearance concealment, distress with functional impairments, and social avoidance are key conceptual domains characterizing HNC‐related BID. Recognition of these psychosocial dimensions of BID in HNC patients can inform development of HNC‐specific BID patient‐reported outcome measures to facilitate quantitative assessment of BID as well as the development of novel preventative and therapeutic strategies for those at risk for, or suffering from, BID.
Growth and Management of Repaired Complete Tracheal Rings after Slide Tracheoplasty
Authors: Wilcox Lyndy J. , Schweiger Claudia , Hart Catherine K. , de Alarcon Alessandro , Peddireddy Nithin S. , Rutter Michael J.
Published: April 2019

Objective

This study documents the growth and course of repaired complete tracheal rings over time after slide tracheoplasty.

Study Design

Case series with review.

Setting

Tertiary pediatric academic medical center.

Subjects/Methods

Medical records of pediatric patients with confirmed tracheal rings on bronchoscopy who underwent slide tracheoplasty between January 2001 and December 2015 were reviewed. Patients who had operative notes documenting tracheal sizing over time were included. Exclusion criteria included tracheal stenosis not caused by complete tracheal rings, surgical repair prior to presentation at our institution, or lack of adequate sizing information. The postoperative follow‐up was examined and airway growth over time documented.

Results

Of 197 slide tracheoplasties performed during the study time period, 139 were for complete tracheal rings, and 40 of those children met inclusion criteria. The median age at time of surgery was 7 months, and the median initial airway size was 3.9 mm (n = 34). The median growth postoperatively was 1.9 mm over a median follow‐up period of 57 months (0.42 mm/year), which is similar to growth rates of unrepaired complete tracheal rings (P =. 53). Children underwent a median of 10 postoperative endoscopies, with time between endoscopies increasing further out from surgery. The most commonly performed adjunctive procedure was balloon dilation.

Conclusions

This is the first study documenting continued growth of repaired complete tracheal rings after slide tracheoplasty. Postoperative endoscopic surveillance ensures adequate growth. Intervals between airway endoscopies can be increased as the child gets older, as the airway increases in size, and as long as symptoms are minimal.
PART I: Religious Traditions and Migration: Movement, Asylum, Borders: Christian Perspectives
Authors: Christiansen S.J. Drew
Published: April 2019

This paper addresses from the point of view of Catholic social teaching and moral theology the questions posed by the intersection of universal human rights, especially the rights of movement, and the assertion of national sovereignty. It begins with a brief note on the theological foundations of Catholic understanding of exile and refuge, then examines the moral problems involved in the clash between rights of movement and the sovereign control of national borders.
Environmental Concerns and International Migration
Authors: Hugo Graeme
Published: April 2019

This article focuses on international migration occurring as a result of environmental changes and processes. It briefly reviews attempts to conceptualize environment-related migration and then considers the extent to which environmental factors have been and may be significant in initiating migration. Following is an examination of migration as an independent variable in the migration-environment relationship. Finally, ethical and policy dimensions are addressed.
Ethics, National Sovereignty and the Control of Immigration
Authors: Weiner Myron
Published: April 2019

This paper examines the debate as to whether migration is a basic human right or if the claims of outsiders are superseded by the principle of national sovereignty – the moral obligation of states to do the best for their own citizens. In evaluating migration and refugees it focuses on issues of open borders, migration selectivity, the capacity of sovereign states to control entry, the claims of refugees, the relationship between sovereignty and justifiable intervention, and the role of public opinion and morals throughout migration policies.
PART V: Ethical Dilemmas of Refugee Policy: The Right of Repatriation – Canadian Refugee Policy: The Case of Rwanda
Authors: Adelman Howard
Published: April 2019

This paper examines the principle of the right to repatriation and the Canadian dilemma in applying that principle in dealing with both refugees and the country from which they originally fled, Rwanda. It is particularly concerned with the right of individuals to be a member of a state and with the right to regain membership in a state from which they fled.
Comments on the European Community Strategy for Endocrine Disruptors
Authors: Phillips Barry
Published: April 2019

Public concern over the possible effects of chemicals that can interfere with the endocrine systems of humans and wild animals (endocrine disruptors [EDs]) has led to calls for immediate regulatory action in many parts of the world. In response, there has been an enormous increase in funding of research on this topic, and hurried attempts have been made to develop and validate methods for identifying EDs. Much of this activity involves experiments on live animals. In the haste to calm public concern over EDs, there is a great danger that animal welfare will be given too little consideration, and that research and testing involving animals will be greatly and unnecessarily increased. Recently, the European Commission published a Community Strategy for Endocrine Disruptors, which outlines actions to be taken to address concerns over EDs. In the short term, the strategy is to concentrate on specific chemicals of concern. Development of test methods is seen as a medium-term objective, linked to further research that will inform test selection and design. Adaptation and amendment of existing legislative instruments to cover endocrine-disrupting effects is envisaged as the long-term objective. The strategy makes no reference to the need to avoid unnecessary animal testing in ED research, test validation or chemical testing. It does, however, avoid the premature initiation of large-scale screening which, as is being promoted and planned in the USA, could involve the use of vast numbers of animals in tests of unproven validity or value.
A Battery of Cell Toxicity Assays as Predictors of Eye Irritation: A Feasibility Study
Authors: Rosenkranz Herbert S. , Cunningham Albert R.
Published: April 2019

The newly developed “chemical diversity approach” was used to determine whether or not it is likely that a panel of in vitro cell toxicity assays capable of predicting in vivo eye irritation could be assembled. The analyses, based upon available and validated structure–activity relationship models of toxicity in cultured human HeLa cells and murine Balb/c 3T3 cells, indicate that a battery of cytotoxicity tests could provide a viable alternative to the animal-based procedure.
The Isolated Perfused Bovine Udder as a Model of Dermal Eicosanoid Release
Authors: Bäumer Wolfgang , Kietzmann Manfred
Published: April 2019

The aim of this study was to examine whether the isolated perfused bovine udder could be used as a suitable in vitro inflammation model. A common in vivo inflammation model is arachidonic acid-induced inflammation in mouse ears. As an in vitro substitute for this model, arachidonic acid was administered topically to the skin of an isolated perfused bovine udder and the subsequent changes in eicosanoid synthesis were examined. As with the mouse-ear model, there was a significant increase in eicosanoid synthesis (prostaglandins E2 and F2α and leukotrienes B4 and C4/D4/E4) following topical irritation. This effect lasted for 3 hours. In addition, the changes in prostaglandin E2 synthesis in the skin following irritation with arachidonic acid were measured by the microdialysis technique. In conclusion, the in vitro model described seems suitable for studies of pharmacological effects on eicosanoid synthesis.
Replacement of Fetal Calf Serum in Cell Cultures by an Egg Yolk Factor with Cholecystokinin/Gastrin-like Immunoreactivity
Authors: Sasse Mirko , Lengwinat Thomas , Henklein Peter , Hlinak Andreas , Schade Rüdiger
Published: April 2019

The in vitro culture of various cell types is an important scientific tool and is becoming increasingly acceptable as a viable alternative to animal experiments. Fetal calf serum (FCS) is a supplement used in many cell culture media, and provides cells with growth factors and cytokines necessary for successful culture. In view of the animal welfare issues surrounding the production of FCS, an alternative agent allowing the replacement or reduction in the use of FCS is desirable. A yolk extract factor, egg yolk factor X (EYF-X), obtained from chicken eggs is described, which facilitates the in vitro culture of a variety of cell types. When the extract was added to a culture medium used for in vitro fertilisation, the number of successful fertilisations was significantly increased. In a further in vitro model (permanent neuronal cell line N2A), the yolk extract significantly stimulated cell proliferation, as well as the growth of cell processes. A set of specific antibodies against different parts of the prepro-cholecystokinin reacted with the extract. The intensity of the reaction depended on the age of the egg (time after the laying date). Analysis by gel chromatography recorded a main protein fraction with an apparent molecular mass of 20–30kDa. This fraction was labelled by Western blot with an antibody with specificity against CCK-octapeptide. These findings suggest that the yolk factor may be a CCK/gastrin-like molecule. Since CCK/gastrin-like molecules have also been detected in the spermatozoa of mammals, the influence on in vitro fertilisation could be explained by the yolk factor replacing the endogenous CCK/gastrin-like molecule destroyed in sperm freezing. The results of this study suggest that it might be possible to replace FCS with EYF-X. The application of the yolk factor to a broad spectrum of cell types remains to be investigated.
Effects of L-Proline on Phase I and Phase II Xenobiotic Biotransformation Capacities of Rat and Human Hepatocytes in Long-term Collagen Gel Cultures
Authors: Beken Sonja , De Smet Karen , Depreter Marianne , Roels Frank , Vercruysse Antoine , Rogiers Vera
Published: April 2019

L-Proline supplementation of the medium for collagen gel cultures of hepatocytes has been shown to improve albumin secretion. A study was made as to whether L-proline is also essential for the maintenance of xenobiotic biotransformation capacities in collagen gel sandwich and immobilisation cultures of rat and human hepatocytes. Key phase I (cytochrome P450-dependent monooxygenase [CYP] and microsomal epoxide hydrase [mEH]) and phase II (glutathione S-transferase [GST]) biotransformation enzyme activities and the secretion of albumin in the culture medium were assessed in the absence and presence of L-proline. CYP and mEH activities were not affected by the addition of L-proline, whereas phase II α-Class GST activity of rat hepatocytes in collagen cultures was decreased. Species differences were demonstrated, as human hepatocytes showed a better maintenance of GST activities than their rat counterparts in the presence of L-proline. Albumin secretion, often considered to be a marker for differentiated cell function, does not parallel the biotransformation capacities of the hepatocytes in culture. Additional results demonstrated an L-proline-mediated enhancement of the proliferation rate of contaminating stellate cells in conventional monolayer culture. Transdifferentiation of stellate cells to proliferating myofibroblasts, along with an increased albumin secretion and collagen synthesis, are characteristic of fibrotic liver. Since the last two phenomena have been observed in L-proline-supplemented collagen gel cultures, it can be concluded that when stable collagen gel cultures of rat hepatocytes are needed for long-term pharmacotoxicological studies, it is preferable to use an L-proline-free culture medium. Further studies on medium optimisation are required for hepatocytes from species other than rat.
The DRAG Test: An Assay for Detection of Genotoxic Damage
Authors: Helleday Thomas , Johansson Fredrik , Jenssen Dag
Published: April 2019

A high throughput assay (the DRAG test) is described, which could be a useful tool for the detection of repairable DNA adducts, and which is based on the inhibition of the growth of DNA repair-deficient Chinese hamster ovary (CHO) cells. The cytotoxicity of a test substance towards DNA repair-deficient CHO cell lines is compared with the corresponding cytotoxicity in the parental wild-type CHO cell line (AA8). A more pronounced toxicity toward a DNA repair-deficient cell line is interpreted as being the consequence of its inability to repair the DNA adduct induced by the compound. (+)-7β,8α-Dihydroxy-9α,10α-epoxy-7,8,9,10-tetrahydrobenzo[ a]pyrene, camptothecin, ethyl methanesulphonate and mitomycin C were used as reference substances, and the overall results indicate that the DRAG test could be useful in the screening of compounds for the production of repairable DNA adducts. The main advantages with the DRAG test are that it provides a relevant endpoint, it is rapid, it requires small amounts of the test item, and it permits a large number of compounds to be tested.
A Compartment Model to Calculate Time-dependent Concentration Profiles of Topically Applied Chemical Compounds in the Anterior Compartments of the Rabbit Eye
Authors: Pospisil Heike , Holzhütter Hermann-Georg
Published: April 2019

Hitherto, none of the existing in vitro methods has been convincingly demonstrated to be suitable as a replacement for the Draize rabbit eye irritation test. We examine the hypothesis that one reason for this is that insufficient consideration has been given to the differences in the effective concentrations at which chemicals operate in vitro and in vivo. When a chemical is applied topically to the eye, the strength of the observed irritation that it elicits depends both on its toxic potential toward cells or tissues, and its effective concentration in the tissues of the eye. Most of the existing in vitro methods are based on isolated cells or tissues, and thus may be useful in assessing the cytotoxic potentials of chemicals. However, a reliable approach to assessing the effective concentrations of chemicals within the various tissues of the eye is lacking. A simplified compartment model is presented for calculating the time-dependent, intra-ocular concentration profiles of topically applied chemicals. The model encompasses the outer surface of the eye, three distinct segments of the cornea (subdivided into the epithelium, stroma and endothelium) and the conjunctiva. Transport through the membranes of these compartments is described as passive diffusion. For the transport coefficients, rate equations are established that contain, as free parameters, the molecular size and the partition coefficient of the chemical, as well as some intrinsic membrane parameters, such as thickness, viscosity and pore density. Numerical values for the unknown membrane parameters were estimated by fitting the theoretical rate equations to measured permeability coefficients. The compartment model was applied to an independent set of 52 test chemicals compiled from the European Commission/UK Home Office validation study. The calculated passage times (required to let 95% of the chemical reach the posterior eye tissues) varied between 0.33 minutes and 50.6 minutes, and are generally much shorter than the typical duration of observed impairments in the cornea or conjunctiva. This finding suggests that short-term contacts of the eye tissues with a chemical are sufficient to elicit long-term eye irritation. An example is given, showing how the conventional approach of using in vitro endpoints as predictors of eye irritation can be improved significantly by incorporating into the prediction the calculated intra-ocular concentration of a chemical.
The Neutral Red Release Assay: A Review
Authors: Zuang Valérie
Published: April 2019

The neutral red release (NRR) assay is a cytotoxicity test that can be used to measure the immediate toxic effects of test substances on the cell membrane, resulting in the leaking of intracellular contents. The assay has already been used for several years to evaluate the cytotoxicities of various kinds of products, such as cosmetics, pharmaceuticals, industrial chemicals and household products. It has undergone in-house validation by many companies, and has been found to be particularly useful for identifying substances that are potentially capable of causing adverse reactions on coming into brief contact with the eye or the skin at relatively high concentrations, such as might occur in an adventitious splash into the eye or onto the skin, followed by a quick rinse. Because of the relatively long existence of the NRR assay, its practicality and its proven usefulness for particular purposes, ECVAM decided to review the status of the method, in order to decide whether prevalidation and formal validation studies on the test might be profitable. The review of the status of the test was carried out by performing a comprehensive review of the literature, and by conducting a survey involving companies and institutes with experience in using the test. Both the review and the survey revealed that the assay could provide extremely valuable information when it was used for particular purposes, such as for the evaluation and comparison of immediate toxic effects on the eye or the skin caused by certain products or chemicals such as surfactants. Most of those who responded in the survey favoured a prevalidation/validation study.
Electrical Stimulation of Transforming Growth Factor-β1 Secretion by Human Dermal Fibroblasts and the U937 Human Monocytic Cell Line
Authors: Todd Ian , Clothier Richard H. , Huggins Mary L. , Patel Nishma , Searle K. Clare , Jeyarajah Santhini , Pradel Lionel , Lacey Karen L.
Published: April 2019

The in vitro effects on human dermal fibroblasts and the U937 human monocytic cell line of three phases of electrical microcurrents generated by the ACE Stimulator were investigated. The growth and viability of growing and confluent dermal fibroblasts were not directly influenced by the separate microcurrent phases. One form of microcurrent (designated phase 1) stimulated both dermal fibroblasts and U937 cells to secrete transforming growth factor-β1 (TGF-β1), which is an important regulator of cell-mediated inflammation and tissue regeneration, but none of the three phases stimulated secretion of the pro-inflammatory cytokine interleukin-6 by U937 cells. The stimulation of TGF-β1 secretion in these experiments was not dramatic (a median increase over control levels of 20–30%), although it could be biologically significant.