bluuebunny/crossref_metadata_2025 huggingface dataset:
Research and development of algorithms for the formation of an effective ensemble of convolutional neural networks for image classification
Authors: Bondarenko Valerii Aleksandrovich , Popov Dmitrii Ivanovich
Published: April 2024

The object of the research is artificial neural networks (ANN) with convolutional architecture for image classification. The subject of the research is the study and development of algorithms for constructing ensembles of convolutional neural networks (SNS) in conditions of limited training sample. The aim of the study is to develop an algorithm for the formation of an effective model based on an ensemble of convolutional SNS using methods of averaging the results of each model, capable of avoiding overfitting in the process of improving the accuracy of the forecast and trained on a small amount of data, less than 10 thousand examples. As a basic network, an effective SNA architecture was developed as part of the ensemble, which showed good results as a single model. The article also examines methods for combining the results of ensemble models and provides recommendations for the formation of the SNA architecture.  The research methods used are the theory of neural networks, the theory of machine learning, artificial intelligence, methods of algorithmization and programming of machine learning models, a comparative analysis of models based on different algorithms using classical ensembling with simple averaging and combining the results of basic algorithms in conditions of limited sampling, taking into account weighted average. The field of application of the obtained algorithm and model is medical diagnostics in medical institutions, sanatoriums during primary diagnostic admission, using the example of a research task, the model is trained to classify dermatological diseases according to input photographs. The novelty of the study lies in the development of an effective algorithm and image classification model based on an ensemble of convolutional NS that exceed the prediction accuracy of basic classifiers, the process of retraining an ensemble of classifiers with deep architecture on a small sample volume is investigated, from which conclusions are drawn on the design of an optimal network architecture and the choice of methods for combining the results of several basic classifiers. As a result of the research, an algorithm has been developed for the formation of an ensemble of SNS based on an effective basic architecture and weighted average averaging of the results of each model for the classification task of image recognition in conditions of limited sampling.
A importância da auditoria interna na gestão das empresas
Authors: Collins Diogo William Braga
Published: April 2024

Na era da globalização, o mercado é competitivo e exige das empresas um patamar cada vez mais avançado de tecnologia e tomada de decisões muito mais rápidas para se manterem no auge e na competitividade que vivemos, e assim conseguirem alcançar e prosperar novos objetivos. Decisões importantes são tomadas na gestão de grandes empresas devido a sua organização e, a Auditoria Interna, vem com a função de dar apoio a gestão visando a melhoria dos negócios, e identificando as áreas problemáticas podendo sugerir mudanças para obter mais desenvolvimento nas organizações, sendo uma forte e ágil ferramenta de trabalho para o sucesso.
Evaluation of Failure Rate for Cortical Dental Implants Placed in the Mandibular Anterior Region: A Systematic Review
Authors: Goyal Srishty , Singh Dhirendra Kumar , Bhola Kumari Lucy , Mohammad Jalaluddin
Published: April 2024

Introduction: To enhance the success of dental implants, it is crucial to understand the factors contributing to implant failure. Practitioners should carefully evaluate the relevance and impact of critical risk factors associated with the mandibular anterior region to gauge the potential for implant failure. Aim: To assess the rates of implant failure for implants placed in the mandibular anterior region. Materials and Methods: For this systematic review, the eligibility criteria for present study included randomised and non randomised clinical trials, prospective cohort studies, and retrospective studies published in the English language between 2000 and 2022. These studies specifically documented dental implant failure rates in the anterior mandible, excluding reviews, in-vitro, cadaveric, and animal studies, as well as case series studies. The participants considered were systemically and mentally healthy individuals aged 18-90 years who had undergone oral restoration using dental implants in the anterior mandibular area. Exclusion criteria involved patients who did not undergo oral restoration with dental implants in the anterior mandibular region, those with systemic diseases affecting implant success, serious cardiac diseases, deficient homeostasis, blood dyscrasias, and psychological diseases. The intervention focused on patients rehabilitated with cortical dental implants in the mandibular anterior region, without a specific comparator or control. Based on the mentioned criteria, nine studies were included. The main outcome of interest was the dental implant failure rate. Results: The review's included studies indicated the placement of 3,718 implants in the mandibular anterior region, with 86 failures, resulting in a 2.31% failure rate, suggesting an approximate 3% failure rate for implants in this area. Conclusion: Given the multifactorial nature of implant failure, the available literature does not support the designation of the mandibular anterior region as a specific risk factor for such failures.
Gastric Tuberculosis Accompanied by Cutaneous Fistula: A Case Report
Authors: Ganapathy Thulasikumar , Thulasikumar Rathnaganpathi
Published: April 2024

Gastric Tuberculosis (TB) is a rare presentation. Posterior gastric perforation with tuberculosis complications is extremely unusual. The authors herewith present a case of a 32-year-old male, with complaints of fever for two months and discharge from the left-side of the back for 15 days, through which ingested food particles were drained. The patient was a known case of Type 2 Diabetes Mellitus (T2DM) and was recently diagnosed with pulmonary TB. He was evaluated with an upper Gastrointestinal (GI) endoscopic biopsy, Contrast-enhanced Computed Tomography (CECT), and Gastrografin (GGF) studies to confirm the diagnosis. He presumably developed gastric ulceration with posterior perforation, tracking through the retroperitoneum and presenting as a subcostal abscess that was inadvertently incised and converted into a fistula. He was treated both medically and surgically. He recovered completely and discharged with full course of Antitubercular Treatment (ATT) drugs and didactic medications. The presence of a cutaneous fistula in association with gastric TB underscores the diverse clinical presentations of this infectious disease, emphasising the importance of early detection and tailored management approaches.
Implementation of Ayurvedic Treatment Section Principles in Hepatocellular Jaundice: A Case Report
Authors: Yadav Pankaj , Kuchewar Vaishali , Yadav Tanika , Gautam Annya
Published: April 2024

Jaundice is a yellow colouring of the skin, mucous membranes, and the conjunctival membrane surrounding the sclera. It is a clinical indication of underlying hepatocellular dysfunction, biliary obstruction, or anomalies in bilirubin metabolism. Kamala might be linked to jaundice based on shared traits. Ayurveda has been well known for treating liver disorders for centuries. In this case report, a 29-year-old male patient, visited the Kayachikitsa outpatient department with primary complaints of pricking pain in the abdomen, loss of appetite, yellow discolouration of urine, nausea, vomiting, generalised weakness, and constipation for 10 days. Based on clinical examination and Liver Function Tests (LFT), he was diagnosed with jaundice. The patient was effectively treated with Shodhan (bio-purification) with sadya virechan (purgation therapy) followed by medicinal treatment for 45 days. Within 7-8 days, there was a significant improvement in abdominal pain with mild tenderness, frequency of vomiting, complaints of anorexia, nausea, constipation, and yellow discolouration of urine, along with substantial improvement in liver function. After 45 days of Ayurvedic treatment, all symptoms and liver functions showed highly significant results. The treatment was given by considering the vitiation of Pitta and Rakta. It can be concluded that by implementing Ayurvedic treatment principles, liver function can be improved in cases of jaundice in a short duration without causing any adverse effects.
Efficacy of Advanced Allied Interventions for Dyspnoea, Exercise Capacity, and Quality of Life among the Geriatric Population: A Literature Review
Authors: Bhattacharya Urvashi , Dutta Abhijit
Published: April 2024

Ageing is a gradual and irreversible pathophysiological process that results in the decline of function in all the body's systems, including the respiratory system. With age, the respiratory muscles lose their strength and become tight, thus affecting lung function. Exercise has been seen to have a positive influence on delaying the ageing process, reducing its ill effects on all systems. Apart from conventional physiotherapy, studies show that other allied therapies, such as the Buteyko breathing technique, respiratory muscle stretch gymnastics, fan therapy, Tai Chi exercise, and many others, have an influence on the cardiorespiratory system. These allied therapies help improve breath control, increase the strength and flexibility of respiratory muscles, stimulate the trigeminal nerve, and contribute differently to reducing symptoms of dyspnoea and fatigue, increasing exercise capacity, and improving Quality of Life (QoL). The purpose of present literature review is to identify various allied therapies that decrease dyspnoea associated with ageing and increase exercise capacity and QoL in the elderly population. A literature search was conducted to find relevant guidelines on interventions for dyspnoea, exercise capacity, and improving QoL in the geriatric population. Total 13 studies related to treatments for dyspnoea and exercise capacity among the geriatric population, aimed at decreasing symptoms and improving QoL, were included in present review article. The number of new and advanced allied methods developed was limited, so more articles could not be added as they did not serve the purpose. The search keywords used were geriatric, dyspnoea, exercise capacity, QoL, and allied therapies. Electronic databases such as PubMed, Google Scholar, Medline, and ResearchGate were used to complete the study. The findings reveal that advanced allied therapies, including fan therapy, Tai Chi exercise, respiratory muscle stretch exercises, pranayama, and video-assisted exercises, are easier and more entertaining ways to engage in regular physical activity, increase exercise capacity, decrease dyspnoea, and improve QoL among the geriatric population.
Efficiency of Shell Waste as a Source of Calcium Carbonate to Produce Calcium Oxide through Calcination Process
Authors: Malau Nya Daniaty , Sianturi Manogari
Published: April 2024

Aims: The aim of this research is to examine the efficiency of batik shellfish shells as a source of calcium carbonate to produce calcium oxide compounds.
Study Design:  The type of research is Experimental.
Place and Duration of Study: Sample: Department of Physics Education, Kristen Indonesia University, Jakarta, between June 2023 and December 2023.
Methodology: There are two stages in the research process, namely the first stage is the preparation and sterilization of batik shellfish shells. The second stage is the calcination of batik shellfish shells to produce CaO Clean the batik shellfish shells using distilled water. Then crush them using a hammer until they become small fragments. Next, dry the small fragments of batik shellfish shells by air-drying them in a closed room. Then, the sample inside the container will undergo calcination process using a furnace/heating furnace with temperature variations of 800°C and 900°C for 8 hours.
Results: The results obtained show the formation of CaO compounds with the characteristic white color of CaO powder and small or fine particle size. The average efficiency of CaO compounds resulting from the calcination of batik shellfish shells at a temperature of 800°C is 61.85%. Meanwhile, the average efficiency of CaO compounds resulting from the calcination of batik shellfish shells at a temperature of 900°C is 55.64%.
Conclusion: The average efficiency of CaO compounds resulting from the calcination of batik shellfish shells at 800°C is greater than the average efficiency of CaO compounds obtained at a calcination temperature of 900°C. This is because the higher the temperature, the purer the CaO compounds produced will be. Therefore, the CaO compound produced from calcination at a temperature of 900°C can be utilized as a source of calcium in various fields.
Antiplasmodial Activity and Phytochemical Evaluation of the Stems of Albizia coriaria and Ficus sur
Authors: Baah Kennedy Ameyaw , Acheampong Akwasi , Amponsah Isaac Kingsley , Nketia Reinhard Isaac
Published: April 2024

Background: Malaria continues to cause havoc on various populations because of the high mortality and economic burden associated with the disease. Progress made in the therapeutics of the disease is threatened by the emerging parasite resistance to currently used first line treatment drugs. This has prompted the search for new, effective, and safe antimalarial agents. The use of traditional medicine in the treatment of various types of diseases including malaria is a regular practice seen with many cultures in Ghana. The stems of Albizia coriaria Welw ex. Oliver and Ficus sur Forssk are such plants used with little evidence about their in vivo efficacy.
Aim: This study therefore aimed to assess the in vivo antiplasmodial potential, and the acute toxicity of the hydroethanolic stem extract of Albizia coriaria and Ficus sur.
Method: Qualitative phytochemical screening was done on the powdered plant material using standard methods. Acute toxicity was carried out according to OECD guidelines using the Limit test. In vivo antiplasmodial activity of the hydroethanolic extract was assessed using the Peter’s 4-day suppressive and Rane’s curative test.
Results: The 70% ethanol extract was safe with the lethal dose above 3000 mg/kg. All the extracts significantly (P < 0.05) suppressed parasitaemia in the Peter’s suppressive and Rane’s curative test with Albizia coriaria producing the highest chemotherapeutic activity of 68.89 and 61.46% in the suppressive and curative test respectively. That of F. sur was less than 50% in both assays. Artesunate reference drug recorded over 80% suppression in the curative test but lesser activity in the suppression assay compared to A. coriaria. Several plant metabolites including terpenoids, flavonoids and coumarins were found in both plant samples.
Conclusion: Albizia coriaria and Ficus sur 70% ethanol extract showed considerable antiplasmoidal activity and were found to be non-toxic in acute toxicity study, thus justifying their safe use in the treatment of malaria as suggested by folklore medicine.
Effects of Zero Tillage Technology in Wheat under Humid Subtropical Climate of Begusarai, Bihar, India
Authors: Kashyap Vinita , Pal Ram , Tiwari R K , Kumari Nidhi , Kundu M S
Published: April 2024

The study was conducted in Rabi of 2019-20, 2020-21 and 2021-22 in Begusarai district of Bihar under Frontline Demonstration programme on “Zero Tillage (ZT)” technology in wheat cultivation by KVK (Krishi Vigyan Kendra) Begusarai. The data on Productivity, Economics, Extension gap and Water saving were calculated and compared with the farmer’s practice (FP). In ZT wheat cultivation, saving in cost of crop establishment, water saving and net return were observed more than FP. The average productivity was recorded 50.37 q/ha and 43.13 q/ha in case of ZT and FP respectively, correspondingly crop establishment cost in case of ZT was found 30.55 per cent lower than FP. Similarly, overall average net return in case of ZT wheat cultivation was recorded as Rs 70813/ha per hectare which is 61 % higher than FP. The average calculated B:C ratio for ZT and FP was 3.47 and 2.06 respectively. The average extension gap, Technology gap and Technology index for three consecutive years were perceived 7.24 q/ha, 7.55 q/ha and 18.66 % respectively. It has been observed that there was decreasing trend of extension gap and technology gap in the selected area which reflects the satisfactory adoption rate of the demonstrated technology for the cultivation of wheat. It was recorded that ZT is significantly superior over the FP in terms of several parameters under the study.
Incidence of Insect Pests and Its Natural Enemies of Cabbage (Brassica oleracea var. capitata) in Relation to Weather Parameters under Field Conditions
Authors: Kishore S. M. , Jemimah N. , Sridevi G. , Reddy M. Venkateswara
Published: April 2024

The study was carried out in the field at the Horticultural Polyhouse, College of Agriculture, Rajendranagar, during the rabi season of 2022–2023. In the field, aphid infestation peaked in the last week of November (48th SMW), while lepidopteran pests (tobacco caterpillar, DBM, and leaf webber) peaked in January (3rd, 2nd, and 1st SMW, respectively). Coccinellids, syrphids, and spiders had average populations of 0.80, 0.21, and 0.03 correspondingly. Aphids were shown to have a non-significant link with weather factors, showing negative correlations with maximum temperature, sunshine, wind, and rainfall and positive correlations with minimum temperature and RH I & II. While leaf webber and DBM showed a non-significant negative connection with sunshine and wind speed, they displayed a non-significant positive correlation with maximum temperature, RH I & II, and rainfall.
Additionally, they showed a strong inverse relationship with evaporation. The maximum and minimum temperatures were shown to have a non-significantly positive connection with tobacco caterpillar and semilooper.
Termite Diversity and its Extent of Crop Damage in Vayalogam Soil Series of Tamil Nadu, India
Authors: Kanna S. Suganya , Premalatha K. , Senguttuvan T. , Suganya S.
Published: April 2024

A survey was conducted to study the distribution of termites in Vayalogam soil series, red sandy loam soil in Tamil Nadu, India. Among the termites collected from eleven places in Pudukottai district, Tamil Nadu all under one genera and three species, the predominant species was Odontotermus wallonensis (Wasmann) which was noticed in seven locations followed by O. assmuthi in three locations and O.obesus in one location. Further, an abundance of O. wallonensis was high (64.64%) followed by O. assmuthi (27.27%.) and O. obesus (9.90%.). The termite, O. wallonensis was recorded more in moundscompared to O. assmuthi and O. obesus, whereas in tree wood logs, three termite species were found. Among the avenue trees, pungam recorded less damage (7.25%) followed by jack trees (10.25%), Polyalthia (15.50%), tamarind (23.50%) and neem and eucalyptus (32.55 and 37.50%). In field crops termite damage was less in maize (5.75%), groundnut (10.25 %), and sugarcane (10.25%). The highest damage was recorded in jack fruit at seedling stage (46.50%) cultivated in Vayalogam soil series. The termite attack was not observed in field crops viz., pulses, castor, brinjal and chilli.
termite species
The Riemann Hypothesis: A Fresh and Experimental Exploration
Authors: Silva Sergio Da
Published: April 2024

This research proposes a new approach to the Riemann Hypothesis, focusing on the interplay between prime gaps and the non-trivial zeros of the Riemann Zeta function. Utilizing various statistical models and experimental analysis techniques, three important insights are uncovered: 1) Granger causality tests reveal a predictive relationship in which past non-trivial zeros may predict future prime gaps; 2) Complex, nonlinear interactions between prime gaps and non-trivial zeros are identified, challenging simple linear correlations; and 3) Causal network analysis reveals intricate feedback-loop relationships. These findings contribute to a better understanding of prime number distribution and the Zeta function, opening up novel possibilities for further mathematical research. The study aims to motivate mathematicians towards a proof or disproof of the Riemann Hypothesis.
Development and Performance Evaluation of Garlic Planter
Authors: Sonwani Suryakant , Victor V.M. , Naik R.K.
Published: April 2024

The study focuses on the development and performance assessment of a garlic planter, conducted at the Swami Vivekanand College of Agricultural Engineering and Technology & Research Station, Indira Gandhi Krishi Vishwavidyalaya, Raipur, Chhattisgarh. The evaluation considered various parameters, including miss index, multiple index, quality of feed index, field capacity, emergence rate index, percentage emergence, and yield attributing characteristics etc. The findings contribute to enhancing garlic cultivation practices, potentially boosting productivity and efficiency in the field.
Enhancing Vascular Adaptations: A Comprehensive Review on the Impact of Theraband Training with Blood Flow Restriction in Women
Authors: Bhardwaj Ritika , Kashyap Richa , Sharma Puja
Published: April 2024

Objective: This comprehensive review delves into the multifaceted impact of Theraband training with blood flow restriction (BFR) on vascular adaptations in women. With a focus on synthesizing current knowledge, the objective is to elucidate the physiological mechanisms, explore clinical applications, and outline potential benefits of this innovative exercise paradigm within the female demographic.
Methods: Employing a systematic approach, a thorough review of pertinent literature was conducted using databases such as PubMed, MEDLINE, and Cochrane Library. Inclusion criteria centered on studies investigating the effects of Theraband training with BFR on vascular outcomes in women. Extracted data encompassed study design, participant demographics, intervention specifics, and key findings.
Results: The review reveals intricate physiological mechanisms underlying vascular adaptations induced by Theraband training with BFR in women, emphasizing notable changes in blood flow dynamics, nitric oxide production, and endothelial function. Clinical applications are discussed, showcasing the potential of this approach in rehabilitation settings and its efficacy in managing cardiovascular and metabolic conditions unique to the female population.
Conclusion: Synthesizing existing evidence, this review underscores the promising role of Theraband training with blood flow restriction in enhancing vascular health in women. By providing comprehensive insights into the physiological intricacies, clinical applications, and potential benefits, this review serves as a pivotal resource for researchers, clinicians, and fitness professionals. It offers guidance for future investigations and practical applications of this innovative exercise strategy, aiming to optimize cardiovascular outcomes specifically for women.
Androgenic Properties and Subchronic Toxicity of the Aqueous Extract of Pycnanthus angolensis (Welw.) Warb. Wood (Myristicaceae)
Authors: Koularambaye Rodolphe , Béboy Sara Nathalie Edjenguèlè , Jignoua Yannick Sani , Feudjio Alfloditte Flore , Choupo Arnaud , Massah Fabiola Jenny , Pieme Constant Anatole , Moundipa Paul Fewou
Published: April 2024

Aims: Pycnanthus angolensis (Welw.) Warb. also known as “Etengué” in the Baka language, is a medicinal plant used by the Baka Pygmies of Cameroon to treat erectile dysfunction. This study aimed to evaluate the androgenic activity and subchronic toxicity of the aqueous extract of Pycnanthus angolensis wood.

Study Design:  Experimental design.

Place and Duration of Study: Laboratory of Biochemistry, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, between November 2022 and October 2023.

Methodology: Twenty-five male Wistar strain rats were divided into 5 groups of 5 rats each including a positive control group that received testosterone enanthate (5 mg/kg) intramuscularly once a week; a normal control group that received distilled water (10 ml/kg) and three test groups which received 134 and 267 and 533 mg/kg of the aqueous extract of Pycnanthus angolensis daily per os. On the 29th day, the animals were killed, and several biochemical parameters were assessed for androgenic properties.

Results: At a dose of 134 mg/kg, the extract significantly increased (p<0.05) the levels of testicular cholesterol, testosterone and serum prostatic acid phosphatase activity compared to those of the normal control. A toxicity study showed that at doses of 134 and 267 mg/kg, the extract did not induce any significant variation (p>0.05) in the creatinine level, but a significant reduction (p<0.05) in of aspartate and alanine aminotransferase activities was recorded. Histopathology revealed destruction of testicular spermatozoa at a dose of 533 mg/kg compared to that of the controls.

Conclusion: These results showed that at a dose of 134 mg/kg, the aqueous extract of Pycnanthus angolensis (Welw.) Warb. wood is capable of stimulating the production of androgens and is tolerated by the rat's body. Our results justified the traditional use of this plant for the treatment of male infertility and erectile dysfunction.
Assessing Marketing Efficiency in the Coconut Value Chain: A Case Study of Western Tamil Nadu's Coconut Landscape
Authors: Kalidas K. , Ravikumar R.
Published: April 2024

India, the world's leading producer of coconuts, also faces challenges in optimizing farmer returns within its coconut value chain. This study investigates the marketing efficiency of Coconut value chain in Western Tamil Nadu, a significant contributor to national production. A multi-stage random sampling technique was employed to collect data from 300 coconut farmers, intermediaries (commission agents, harvest contractors), processors, wholesalers, retailers, and consumers across four districts (Coimbatore, Tirupur, Erode, and Namakkal). Marketing efficiency was assessed using Shepherd's method, Acharya's modified approach (incorporating post-harvest losses), and Calkin's index. Three marketing channels were identified: (i) Through Harvest Contractors (CVC I), (ii) Through Commission Agents (CVC II), and (iii) Through Farmer Producer Companies (FPCs) (CVC III). This article delves into the factors contributing to these results, explores the existing literature on coconut marketing efficiency, and proposes FPCs as a key strategy for enhancing farmer livelihoods in the region. The findings highlight the dominance of FPCs (CVC III) as the most efficient marketing channel across all districts, followed by CVC I (through harvest contractors) in most cases.
Finding the right case: the role of predictive features in memory for aviation accidents
Authors: O'Hare David , Mullen Nadia , Wiggins Mark , Molesworth Brett
Published: January 2008

Three experiments examined the role of story structure in memory for written aviation accident reports by both pilots and nonpilots. Accident reports follow a standard format providing setting, complication, decision and outcome information. Following the ‘predictive features’ model, it was hypothesized that expertise would facilitate recall, and that pilots would recall most effectively with the complication feature. Pilot and nonpilot participants read and recalled 4 (Experiment 1) or 8 (Experiment 2) accident reports. With four cases, pilots recalled more than nonpilots, but no difference was found with eight cases. A primacy effect for pattern of recall was found in Experiment 1 with the setting and complication features most effective in triggering case recall. When task difficulty was increased (Experiment 2), the complication feature alone was the most effective. In Experiment 3, we manipulated text structure and found that complication and decision features were better recognized than setting or outcome features by nonpilots. The finding across three studies that the complication feature was consistently the most effective for retrieving aviation accident reports supports the ‘predictive features’ model. Copyright © 2007 John Wiley & Sons, Ltd.
Children's knowledge acquisition through film: influence of programme characteristics
Authors: Michel Eva , Roebers Claudia M.
Published: January 2008

Several characteristics of educational programmes for children are discussed to influence learning of content. In the present study, positive effects of a preview and inserted summaries in educational films for learning are examined. A total of 127 6‐and 8‐year‐old participating children watched one of the four educational film versions: The original film (without preview and summaries), a version with a preview, with inserted summaries or with a verbal ‘preview’. One week later, children's recollection of facts was tested in a memory interview. Results show that previews and summaries in educational films can enhance learning, and that visual scene repetition appears to further boost knowledge acquisition. Formal and content characteristics of educational programmes are discussed in terms of the underlying mechanisms influencing children's cognitive processing and learning. Copyright © 2008 John Wiley & Sons, Ltd.
Predictive adaptive control of plants with online structural changes based on multiple models
Authors: Lourenço J. M. , Lemos J. M.
Published: January 2008

The objective of this paper is to present a new algorithm to improve the adaptation rate of a predictive adaptive controller. For that sake, the possible plant dynamic outcomes are covered by a bank of models. Each model is used to re‐initialize the adaptive controller every time there is a large change in dynamics. The contribution of the paper consists in the development of a procedure that includes additional models in the bank when found suitable according to defined criteria. The algorithm is demonstrated in a benchmark problem consisting of the position control of two masses coupled by a spring of varying stiffness. Copyright © 2008 John Wiley & Sons, Ltd.
Characterization and astrocytic modulation of system L transporters in brain microvasculature endothelial cells
Authors: Omidi Yadollah , Barar Jaleh , Ahmadian Somaieh , Heidari Hamid Reza , Gumbleton Mark
Published: January 2008

Brain trafficking of amino acids is mainly mediated by amino acids transport machineries of the blood–brain barrier (BBB), where astrocytes play a key maintenance role. However, little is known about astrocytes impacts on such transport systems, in particular system L that consists of large and small neutral amino acids (NAAs) transporters, that is, LAT1/4F2hc and LAT2/4F2hc, respectively. In the current investigation, functionality and expression of system L were studied in the immortalized mouse brain microvascular endothelial b.End3 cells cocultured with astrocytes or treated with astrocyte‐conditioned media (ACM). LAT2/4F2hc mediated luminal uptake of L‐phenylalanine and L‐leucine resulted in significantly decreased affinity of system L in b.End3 cells treated with ACM, while LAT2/4F2hc mediated luminal uptake of L‐alanine remained unchanged. Gene expression analysis revealed marked upregulation of LAT1 and 4F2hc, but downregulation of LAT2 in b.End3 cells cultured with ACM. The basal to apical transport of L‐phenylalanine and L‐alanine appeared to be significantly greater than that of the apical to basal direction in b.End3 cells indicating an efflux functionality of system L. No marked influence was observed for transport of L‐phenylalanine in b.End3 cells cocultured with astrocytes, while a slight decrease was seen for L‐alanine in the basal to apical direction. Based on our findings, we propose that system L functions as influx and/or efflux transport machinery displaying a greater propensity for the outward transport of large and small NAAs. Astrocytes appeared to modulate the transcriptic expression and uptake functionalities of system L, but not the transport activities. Copyright © 2008 John Wiley & Sons, Ltd.
Application of different training methodologies for the development of a back propagation artificial neural network retention model in ion chromatography
Authors: Bolanča Tomislav , Cerjan‐Stefanović Štefica , Ukić Šime , Rogošić Marko , Luša Melita
Published: January 2008

The reliability of predicted separations in ion chromatography depends mainly on the accuracy of retention predictions. Any model able to improve this accuracy will yield predicted optimal separations closer to the reality. In this work artificial neural networks were used for retention modeling of void peak, fluoride, chlorite, chloride, chlorate, nitrate and sulfate. In order to increase performance characteristics of the developed model, different training methodologies were applied and discussed. Furthermore, the number of neurons in hidden layer, activation function and number of experimental data used for building the model were optimized in terms of decreasing the experimental effort without disruption of performance characteristics. This resulted in the superior predictive ability of developed retention model (average of relative error is 0.4533%). Copyright © 2008 John Wiley & Sons, Ltd.
Two‐dimensional LC‐MS/MS in detection of peptides in hypothalamus of the rat subjected to hypoxic stress
Authors: Mihailova Albena , Karaszewski Bartosz , Faergestad Ellen Mosleth , Hauser Roman , Nyka Walenty M. , Lundanes Elsa , Greibrokk Tyge
Published: January 2008

A capillary 2‐D LC method coupled with IT MS has been used for separation and identification of peptides in rat hypothalamus. Animals of two different age groups (8 and 50 wk) were exposed to two different rates of CO2 in inhaled air to investigate the influence of different hypoxia/hypercapnia levels and their stress‐related factor on the peptide excretion. Peptide compounds were fractionated (strong cation exchange chromatography), trapped, and separated (RP chromatography), and MS/MS mass spectra were used for identification. About 107 peptide compounds were identified and 88 of them were semiquantified. Among the characterized peptides, there were fragments from proteins such as proenkephalin A, proSAAS, prosomatostatin, prooxytocin, vasopressin, etc. Explorative principal component analysis (PCA) combined with hypothesis testing was applied to the obtained data to investigate the impact of age and hypoxic stress factors on the peptide pattern. Twenty‐six peptides revealed significant differences in concentrations between the animal groups influenced by age and influx rate.
Reversible Chain Transfer Catalyzed Polymerizations (RTCPs) of Styrene and Methyl Methacrylate with Phosphorus Catalysts
Authors: Goto Atsushi , Hirai Norihiro , Tsujii Yoshinobu , Fukuda Takeshi
Published: January 2008

Summary: Phosphorus compounds were employed as catalysts in Reversible Chain Transfer Catalyzed Polymerization (RTCP), a novel class of living radical polymerization (LRP) which we had recently developed. Low‐polydispersity polystyrene and poly(methyl methacrylate) with predicted molecular weights were obtained with a fairly high conversion in a fairly short time. These catalysts are particularly featured by their high reactivity hence small amounts being required, low toxicity, and low cost. Some phosphorus catalysts used in this work are among the least expensive catalysts/mediators of LRP developed so far.
Kinetics of Controlled/Living Radical Polymerization in Emulsified Systems
Authors: Tobita Hidetaka
Published: January 2008

Summary: For the controlled/living radical polymerization (CLRP) in which the active period during the chain formation is extremely small, ϕA < 1, such as the cases of usual SFRP and ATRP, the polymerization rate can be made larger by increasing the average number of monomeric units added during a single active period, $\bar P_{n,SA}$. The $\bar P_{n,SA}$‐value is inversely proportional to the trapping agent concentration [X], and the polymerization rate is controlled by [X]. For small particles, even with a single trapping agent, [X] in the particle could be larger than that in corresponding bulk polymerization, and the polymerization rate decreases with D, where Dp is the particle diameter. On the other hand, for CLRPs whose ϕA‐value is not very much smaller than unity, say ϕA>0.01, such as some of RAFT polymerization systems, the polymerization rate can be made larger by increasing the kinetic chain length for a given initiation frequency. For such reaction systems, the polymerization rate can be enhanced significantly by employing the emulsified polymerization systems.
A Novel GPPS/cis‐SB Blend with High Performance
Authors: Zhu Han , Wu Yi‐Xian , Zhao Jiang‐Wei , Xu Ri‐Wei , Huang Qi‐Gu , Wu Guan‐Ying
Published: January 2008

Summary:GPPS/cis‐SB blends with high performance were prepared by adding 3–5 wt.‐% stereoregular butadiene‐styrene block copolymers (cis‐SB) with a highcis‐1,4 configuration of around 97% into general purpose polystyrene (GPPS). The micromorphology of the GPPS/cis‐SB blends was characterized by transmission electron microscopy (TEM). Mechanical properties including tensile and impact properties were studied and the fracture surfaces of tensile and impact test specimens were characterized by scanning electron microscopy (SEM). PB domains of 10–30 nm with a blurry interface were tethered by continuous PS domains. The fracture surface of the tensile test piece of GPPS was relatively smooth while the fractography of patch patterns separated by river patterns was formed when the tensile specimens of GPPS/cis‐SB blends were broken, which may be due to the nanometer‐scale rubber phases with highcis‐1,4 configuration and some partially crystalline PS segments in thecis‐SB block copolymer. It is found that GPPS could be greatly toughened by introduction of a small amount ofcis‐SB and the tensile strength and elongation at break could also be increased.
Landau Mean‐Field Approximation of Percolation in Conductive Polymer Composites
Authors: Song Yihu , Zheng Qiang
Published: January 2008

Summary: A novel approach of the percolation behavior in conductive composites was proposed on the basis of Landau mean‐field theory. The percolation transition is treated as a concentration‐derived phase transition of conductive particles from dispersion to flocculation so as to form a dissipative percolating network. A formulation of conductivity as a function of filler volume fraction in the percolation transition region was established, which was validated in high‐density polyethylene/carbon black (HDPE/CB) composites from two different laboratories and also in cured epoxy/CB composites of Fournier et al. At high CB concentrations above the percolation threshold, the conductive behavior in HDPE/CB composites follows the statistical percolation theory.
Novel Amphiphilic Poly(N‐vinylpyrrolidone) Block Copolymer: Aggregative Behavior and Interaction with DNA
Authors: Zhang Lifen , Meng Lingzhi , Lu Xiaoju , Liu Yunhai
Published: January 2008

Summary: Novel block copolymers poly(N‐vinylpyrrolidone)‐block‐poly[(tert‐butoxy) carbonyl] tryptophanamido‐N′‐methacryl thiourea (PVP‐b‐PTAM‐I, II and III) were synthesized by atom transfer radical polymerization (ATRP) in DMF using PVP‐Cl as macroinitiator. The structures of the copolymers were characterized by UV‐vis and GPC‐MALLS. The results revealed that the copolymers with controlled molecular weight and relatively low polydispersity (PDI < 1.34) were obtained through ATRP. By means of dynamic light scattering (DLS) and transmission electron microscopy (TEM), we demonstrated that copolymer PVP‐b‐PTAM self‐aggregated to form spherical micelles in aqueous solution and the size of the micelles increased with increasing hydrophobic contents. The interaction of PVP‐b‐PTAM with DNA was explored using ethidium bromide (EB) quenching experiments. The interaction between PVP‐b‐PTAM and DNA markedly depended on both the copolymer concentration and composition. The PVP‐b‐PTAM‐II and III with higher hydrophobic contents exhibited highly complexed DNA ability at low copolymer concentration, such as 0.017 mg/mL, relative to PVP‐b‐PTAM‐I. As the copolymer concentration further increased for PVP‐b‐PTAM‐II and III, they first exhibited a sharply decreased affinity for DNA and then kept steady. The interaction mechanism between the amphiphilic copolymers and the EB‐DNA complex was discussed in detail.
Interaction of elementary waves on a boundary for a hyperbolic system of conservation laws
Authors: Yao Aidi , Sheng Wancheng
Published: January 2008

In this paper, we study the interaction of elementary waves including delta‐shock waves on a boundary for a hyperbolic system of conservation laws. A boundary entropy condition is derived, thanks to the results of Dubois and Le Floch (J. Differ. Equations 1988; 71:93–122) by taking a suitable entropy–flux pair. We obtain the solutions of the initial‐boundary value problem for the system constructively, in which initial‐boundary data are piecewise constant states. Copyright © 2008 John Wiley & Sons, Ltd.
Error estimates of mixed methods for optimal control problems governed by parabolic equations
Authors: Xing Xiaoqing , Chen Yanping
Published: January 2008

In this paper, we investigate the error estimates for the solutions of parabolic optimal control problem by mixed finite element methods. The state and co‐state are approximated by the lowest‐order Raviart–Thomas mixed finite element spaces, and the control is approximated by piecewise constant functions. The convergence for the states, co‐states and the control is demonstrated. Copyright © 2008 John Wiley & Sons, Ltd.
Treatment with inhaled corticosteroids in asthma is too often discontinued
Authors: Breekveldt‐Postma Nancy S. , Koerselman Jeroen , Erkens Joëlle A. , van der Molen Thys , Lammers Jan‐Willem J. , Herings Ron M. C. ,   for the CAMERA Study Group
Published: January 2008

Purpose

To study persistence with inhaled corticosteroids (ICS) and its determinants in asthma‐patients.

Methods

From the PHARMO database, asthma‐patients (age < 35 years) with a first dispensing for ICS in 1999–2002 and ≥ 2 dispensings in the first year were included. Persistence during the first year was defined as the number of days from start to time of first failure to continue renewal of the initial ICS. Potential determinants of persistence were assessed at ICS‐start and 1 year before.

Results

The study‐cohort included 5563 new users of single ICS and 297 of fixed‐combined ICS. Less than 10% of patients using single ICS and 15% of patients using fixed‐combined ICS were persistent at 1 year. Similar persistence‐rates were observed when stratified for age (children/adolescents: 0–18 years and adults: 19–34 years). Increased persistence with single ICS was observed with the type of ICS (budesonide), prescriber (specialist), prior use of long‐acting beta‐agonists, previous hospitalization for asthma, metered‐dose inhaler, low starting‐dose and once‐daily dosing regimen at start. Persistence with fixed combined ICS‐treatment increased with younger age and was decreased in patients having high starting‐dose of ICS and prior use of antibiotics.

Conclusion

New users of both single and fixed combined ICS have alarming low persistence rates with ICS‐treatment in the first year of follow‐up. Persistence was mainly related to patient factors, such as severity of disease, and to treatment‐related factors, such as once‐daily dosing frequency. Copyright © 2008 John Wiley & Sons, Ltd.
Technologies and methods for sample pretreatment in efficient proteome and peptidome analysis
Authors: Jiang Xiaogang , Ye Mingliang , Zou Hanfa
Published: January 2008

Although great progresses have been made in proteomics during the last decade, proteomics is still in its infancy. Extreme complexity of proteome sample and large dynamic range of protein abundance overwhelm the capability of all currently available analytical platforms. Sample pretreatment is a good approach to reduce the complexity of proteome sample and decrease the dynamic range. In this article, we present an overview of different technologies and methods for sample pretreatment in efficient proteome and peptidome analysis. Methods for isolation of rare amino acid‐containing peptides, terminal peptides, PTM peptides and endogenous peptides are reviewed. In addition, two automated sample pretreatment technologies, i.e. automated sample injection and on‐line digestion, are also covered.
Target coatings and desorption surfaces in biomolecular MALDI‐MS
Authors: König Simone
Published: January 2008

MALDI‐MS is an extremely flexible technique and can be synergistically used in conjunction with established bioanalytical methods such as PAGE or SPR. To that end, slight modifications on the sample target plate may be necessary. Those can involve the use of hydrophobic coatings for improved sample deposition and desalting or that of sensor surfaces for on‐target bioaffinity experiments. In particular the latter have evolved considerably over the past years. Surface coatings using polysaccharide or polycarboxylate hydrogels were adopted from unrelated techniques and they proved very suitable for bioaffinity MS. The developments concerning target modification and derivatization are reviewed.
Matrix‐assisted laser desorption/ionization signal enhancement of peptides by picolinamidination of amino groups
Authors: Kim Jong‐Seo , Kim Ji‐Hyun , Kim Hie‐Joon
Published: January 2008

Picolinamidination of amino groups in peptides was carried out using ethyl picolinimidate tetrafluoroborate synthesized from picolinamide and triethyloxonium tetrafluoroborate. The N‐terminal amino group as well as the ε‐amino group of lysine were derivatized. The matrix‐assisted laser desorption/ionization (MALDI) signal of a peptide was enhanced 20–35‐fold upon picolinamidination depending on the number of amino groups derivatized. The signal enhancement effect is much higher than that of acetamidination or guanidination previously reported. Improved protein identification by mass mapping of the derivatized peptides was demonstrated. Copyright © 2008 John Wiley & Sons, Ltd.
Tribologically activated surface layers in lubricated DLC contacts
Authors: Podgornik B. , Vižintin J.
Published: January 2008

In the past, adequate functionality of high‐performance components would have been impossible without advanced lubricant additive chemistry and proper lubricant formulation. Especially anti‐wear (AW) and extreme‐pressure (EP) additives are crucial in minimising friction and wear and protecting contact surfaces under severe contact conditions. Introduction of diamond‐like carbon (DLC) coatings, on the other hand, opens further possibilities in improving performance of highly loaded components, which can no longer be achieved only by lubricant design.

The aim of the present research was to determine the mechanism responsible for the low‐friction behaviour of boundary lubricated DLC coatings when lubricated with lubricants containing EP or AW additives and to investigate the influence of contact conditions. Tests were performed under reciprocating sliding motion using ball on flat test configuration, with ball‐bearing steel ball being loaded against undoped and W‐doped DLC‐coated discs, respectively. Results of the investigation clearly show that in the case of W‐doped DLC coatings, low‐friction behaviour under boundary lubrication is governed by formation of WS2‐containing tribolayers, which are contact conditions dependent and can reduce friction by more than 50%. Copyright © 2008 John Wiley & Sons, Ltd.