bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on intrinsic expansion coefficients in Rydberg atomic heterodyne receiving link
Authors: Wu Feng-Chuan , An Qiang , Yao Jia-Wei , Fu Yun-Qi ,   College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China
Published: December 2022

Rydberg atom can respond to weak microwave electric field signal in real-time by using its electromagnetically induced transparency effect to realize down conversion of space microwave electric field signal, which can be used as a superheterodyne receiver. The Rydberg atom superheterodyne receiver is a new receiving system composed of Rydberg atoms, photodetectors, and electronic information processing modules. Presently, the physical response mechanism of Rydberg atomic superheterodyne receiving technology is studied in depth. However, no complete receiving link analysis model has been established, which is not conducive to optimizing its system performance. Based on the physical mechanism of the Rydberg atom responding to the microwave electric field, this paper introduces the concept of intrinsic expansion coefficient, establishes and experimentally verifies the receiving link model of the Rydberg atom superheterodyne receiver, and briefly discusses the influence of the intrinsic expansion coefficient on the system sensitivity and response characteristics, thereby providing the theoretical guidance for optimizing the performance of the Rydberg atom superheterodyne receiving system. In the end, the Rydberg atomic and the electronic receiving links' sensitivity performance is discussed and compared.
Standing on the shoulders of Scandinavian giants?
Authors: Aspaas Per Pippin
Published: December 2022

Das Werk „Demonstratio“ („Beweis, dass die Sprache der Ungarn und Lappen dieselbe ist“) des ungarischen Jesuiten Joannes (János) Sajnovics ist ein Klassiker der finno-ugrischen Sprachwissenschaft. Sajnovics war ein Astronom ohne Erfahrung in vergleichenden Sprachstudien, als er in den Jahren 1768–69 an einer astronomischen Expedition in der Finnmark teilnahm. Erst als er in Nordnorwegen ankam, begann er scheinbar unvorbereitet mit seiner Untersuchung. Im Winter 1769/70 war er in Kopenhagen. Während dieses Aufenthalts hatte Sajnovics Kontakt zu Mitgliedern der Königlich Dänischen Gesellschaft der Wissenschaften, wo er seine Theorie vorstellte. Seine bahnbrechende „Demonstratio“ wurde in zwei Ausgaben gedruckt, die erste 1770 in Kopenhagen und die nächste im folgenden Jahr in Trnava. Eine genaue Lektüre der ersten Ausgabe zeigt, dass die innovative Methodik von Sajnovics fast ausschließlich auf skandinavischer Forschungsliteratur basierte. Hinweise auf mitteleuropäische Gelehrte und ihre Theorien durchziehen die zweite überarbeitete Auflage der Demonstratio, die jedoch erst nach der Rückkehr von Sajnovics und seinem Mentor Maximilian Hell in das Habsburgerreich gemacht wurde.
Kulturwissenschaft: Intellektuelle intervention zwischen analyse, widersprüchlichkeit und kritik
Authors: Ehalt Hubert Christian
Published: December 2022

abstrakt
Vennskap i stedet for brorskap
Authors: Janss Christian
Published: December 2022

I 1959 holdt filosofen Hannah Arendt pristalen „Gedanken zu Lessing. Von der Menschlichkeit in finsteren Zeiten.“ I tidsrommet 1960–1966 holdt poeten Nelly Sachs taler ved mottagelsen av ulike priser. I sine taler er de opptatt av forholdet mellom den enkelte og verden, hver fra sitt ståsted, men begge betoner hvor viktig det er å være åpen for og delta i verden. Arendt utvikler begreper for å beskrive verden som offentlig rom, som „Weltzugewandtheit“ og „Zwischenraum“ –  i kontrast til brorskapets lukkethet. Disse begrepene viser seg anvendelige for å beskrive hva Nelly Sachs omtaler som „Weltverbundenheit“. Artikkelen prøver å vise at Nelly Sachs‘ verk, som kan virke lukket og tilbaketrukket, inneholder en bevegelse fra det broderlige og lukkede mot et stort fellesskap av mennesker.
A Survey of Contemporary and Emerging Research Methods in Information Systems Research
Authors: Nyale Duncan , Mwangi Salome , Karume Simon
Published: December 2022

This paper's major goals are to present an overview of the current research trends in information systems (IS), investigate the causes of those trends, evaluate the relevance and effectiveness of those trends, and then suggest strategies to enhance IS research. The study builds a foundation for understanding information systems research. The concepts of positivism, interpretivism, qualitative, and quantitative research are discussed in this paper along with current trends in information system research methodologies. It also highlights the distinctions between qualitative and quantitative approaches and provides justification for the use of case studies in information systems. The study's methodology involved online desk research, with a primary focus on studies between 2018 and 2022.
Agricultura familiar e a cadeia do mel: uma análise bibliométrica
Authors: de Brito Isabel Bruna Correia , Siqueira Elisabete Stradiotto , Siqueira Filho Valdemar , De Oliveira Talita Paloma
Published: December 2022

Este artigo objetiva explorar o acervo das bases de dados Web of Science e Scopus (Elsevier), buscando as publicações científicas que relacionem os termos agricultura familiar e a cadeia do mel, visando entender como esses temas estão sendo tratados. A pesquisa se classifica como qualitativa, bibliográfica e descritiva, utilizando técnicas de bibliometria. Por meio da busca por palavras-chaves “Beekeeping chain; Family farming; bee; Family agriculture” de forma singular e, também, simultânea. Após leitura dos resumos foram encontrados 32 trabalhos compuseram o material para pesquisa. A pesquisa contribuiu na compreensão dos nexos que articulam a agricultura familiar e a apicultura, evidenciando que a lógica produtiva, subsistência e a sustentabilidade são fatores de aproximação dessas duas formas de produção, reforçando a compreensão que a apicultura é uma alternativa de renda de forma sustentável para os agricultores familiares. A análise dos artigos permitiu identificar um fbaixo volume nas produções que relacionem as temáticas de agricultura familiar e cadeia do mel. Através do software VOSviewer gerou-se um mapa das redes de palavras-chave dos artigos e foram analisados os clusters formados nessa ferramenta. Os achados indicam um aumento da produção na temática de cadeia de valor do mel, com foco na lógica produtiva, na subsistência/sobrevivência e na sustentabilidade. Foram encontradas duas produções com foco no trabalho familiar e cadeia do mel simultaneamente. O estudo realizado incidiu no encontro de informações pertinentes para o conhecimento acerca da relevância da agricultura familiar e sua relação com a cadeia do mel.
Orientações de melhores práticas de governança corporativa emitidas pelos países do BRICS ao Setor Público
Authors: Charão Felipe Pereira , De Oliveira Oderlene Vieira , Maia Laíse Luciene Costa de Lima
Published: December 2022

Objetivo da pesquisa: consistiu em averiguar os órgãos de controle, além dos instrumentos e códigos de melhores práticas de governança que são empreendidos pelos países membros do BRICS.Enquadramento teórico: governança corporativa pública e controle externo foram os temas que fundamentaram teoricamente a pesquisa.Metodologia: trata-se de pesquisa de natureza descritiva, fazendo uso de abordagem qualitativa, viabilizada por meio de análise de documentos disponíveis nos sítios governamentais do Brasil, Rússia, Índia, China e África do Sul. Resultados: os resultados demonstram que apenas o Brasil e a China possuem um órgão externo, que, entre as suas funções, metrifica e fiscaliza as decisões do Executivo e empreende as boas práticas de governança corporativa pública.Originalidade: o estudo buscou abordar o papel dos órgãos de controle externo  como protagonista da discussão da boa governança na administração pública. Contribuições teóricas e práticas: academicamente os achados da pesquisa contribuem para a temática da governança corporativa pública, tendo em vista ser esta pouco explorada. E como contribuição prática, os achados da presente pesquisa podem estimular as nações, não apenas dos cinco países analisados, a dispor cada vez mais de órgãos externos capazes de avaliar e auxiliar nas decisões do Executivo.
Analysis of innovation in individual public transportation usability: Uber case
Authors: Silveira Júnior Aldery , Rodrigues Evaldo César Cavalcante , Cancian Marco Rogério Soranzo , Da Silva Roberto Bernardo
Published: December 2022

This study aims to analyze the users´ perception regarding the innovations of the individual public transportation in Federal District, focused on Uber company. Throughout Brazil, the individual public transportation was known as monopolized by taxi service. The lack of competition led to low service of service. However, with the technological development, private companies started to develop competitive and innovative forms for entering the market. Through the tool for multi-criterion analysis was verified the user perception in regard to the service provided by Uber. The survey of data was carried out in two ways. First, through group discussion with experts in transport of UnB and subsequently through the implementation of forms with the service users, through targeted dissemination carried out by social networks and via email. For analysis of the data the Multi-criteria Methodology for Supporting the Constructivist Decision (MCDA-C) was used, so that the qualitative data could be quantified. This methodology allows the consideration from the experts´ view of the experts for, from them, understand the users´. The survey results showed how the innovative processes that aim to raise the quality of care and implementation of individual transportation services in the Federal District are relevant to users.
Análise representativa da arrecadação do imposto predial e territorial urbano (IPTU) frete as receitas totais das cidades do Vale do Mamanguape no período de 2016-2020
Authors: Batista Aline Dayanne Diniz Figueiredo , Macêdo João Marcelo Alves , Cabral Luiz Marcelo Martins do Amaral Carneiro , Pessoa Luiz Gustavo de Sena Brandão
Published: December 2022

Os municípios têm responsabilidades administrativas decorrentes de sua competência constitucional. Para que sejam desenvolvidas políticas públicas condizentes com a necessidade da população é necessária a arrecadação de receitas, dentre as quais o Imposto Predial e Territorial Urbano (IPTU). Assim, pela competência administrativa e tributária ser dos municípios e do distrito federal, estes podem atuar diligentemente dosando o esforço e as ações. Nesse aspecto cabe as municipalidades, por menor que sejam, estruturar-se para tanto, a fim de melhor geri-lo. Assim o objetivo foi analisar o volume do IPTU arrecadado em relação ao total das receitas arrecadadas nas cidades da Região Geoadministrativa do Vale do Mamanguape nos anos de 2016-2020. Objetiva-se entender a dinâmica da arrecadação, avaliando-a pela flutuação anual, pelos indicadores de PIB e PIB per capta e pelo Índice de Gestão Fiscal (IGF), bem como pelo Índice de Desenvolvimento Municipal (IDM), ambos desenvolvidos pela Federação das Indústrias do Estado do Rio de Janeiro (FIRJAN) para os municípios do Brasil. Esses índices propõem-se a auxiliar no entendimento da gestão e do desenvolvimento dos municípios. A metodologia desse estudo teve uma construção teórico empírica, com o uso do método dedutivo, emprego de estatística descritiva e base teórica em pesquisas, artigos e outros. Os dados foram coletados no Sistema SAGRES do Tribunal de Contas do Estado da Paraíba (TCEPB), por meio dos lançamentos oficiais da arrecadação do IPTU dessas cidades e demais registros da receita. Junto à FIRJAN obteve-se os dados do IGF e do IDM. Já o PIB e o PIB Per capta por município foi coletado junto ao Instituto Brasileiro de Geografia e Estatística – IBGE. Como resultados se verificou que a arrecadação do IPTU cresceu na mesma proporção que os demais tributos municipais de cada uma das cidades integrantes do Vale do Mamanguape. No entanto, se verificam o descontrole arrecadatório e falta de planejamento como marcas das gestões municipais. Por fim, a pesquisa identificou quanto aos dados referentes a arrecadação de IPTU estão relacionadas às condições socioeconômicas dos municípios e que neste tal momento, período avaliado nos últimos 5 anos, as cidades encontram-se em um bom crescimento socioeconômico, porém ainda vivenciam ausência de esforços para melhoria da estrutura da administração fiscal.
Seasonal Rearing Performance of Multivoltine Pure Mysore Silkworm in Southern dry Zone of Karnataka, India
Authors: Hosamani Vinayak , Chandrashekar R. H. , Hosamani Venkatesh , Manjunath G. R.
Published: December 2022

The differences in the seasons and environmental components considerably affect the quality of the multivoltine silk worm seed crop such as cocoon weight, shell weight, and cocoon shell ratio. Frequent fluctuations in the environmental conditions day to day and season to season point up the importance of management of temperature and relative humidity for sustainable seed cocoon production in the basic seed farms. Hence to know the role of seasonal temperature and humidity on growth and development of Multivoltine silkworm, present study conducted at P2 Basic Seed Farm Nagenahalli, Central Silk Board, Karnataka to assess the seasonal performance of the multivoltine silkworm using various parameters. In the study all the data were recoreded were subjected to the correlation and the correlation results revealed significantly higher hatching per cent yield (number and weight)/ 100 dfls (Kg),single cocoon weight(gm) and single cell weight (gm) were 95.67, 43414.45 ( by number) and 57.70 kg (by weight), 1.233 and 0.180, respectively) during the winter season,  whereas significantly higher weight of 10 matured larvae (28.01g) and shell weight (0.180) were recorded during rainy season. Further, significantly lower fecundity (480), hatching% (94.98), larval duration (28 days), weight of 10 matured larvae (25.80g), cocoon yield/100dfl (43.29 kg), single cocoon weight (1.146g), single cell weight (0.169g), pupation (95.22%) and cocoon leaf ratio (21.95) were recorded during summer.among the seasons. In all, winter season was more ideal for the rearing of multivoltine silkworm in the southern dry zone seed area of Karnataka with superior cocoon and egg characters due to lower temperature and humidity fluctuations.
Effect of Soil Test Crop Response (STCR) and STCR –Integrated Plant Nutrition System (IPNS) Based Fertilizer Prescription Equations on Maize Productivity, Economics and Soil Fertility Status in Vertisols of Northern Karnataka
Authors: Reddy K. Jaisimha , Chandrashekara C. P. , Biradar D. P. , Rajakumar G. R. , Kanannavar P. S.
Published: December 2022

A study on Soil Test Crop Response based Integrated Plant Nutrition System (STCR - IPNS) was conducted adopting an Inductive cum Targeted yield model in vertisols of Northern Karnataka at Main Agricultural Research Station (MARS), UAS, Dharwad, Karnataka during kharif 2020-21 in order to develop STCR and STCR-IPNS fertilizer prescription equations (FPEs) for achieving desired yield targets of maize. Fertilizer doses at varying soil test values, for attaining 60, 80 and 100 q ha-1 target grain yield of maize have been worked out based on the initial soil test values of available N, P and K and the quantities of N, P and K added through farm yard manure (FYM). Using these equations, validation trials were conducted during kharif 2021-22 at MARS, Dharwad and Irrigation Water Management Research Centre (IWMRC), Belavatgi. The results of the experiment indicated that at both the locations, the per cent achievement of the targeted yield was within ± 10 % variation proving the validity of the equations for prescribing integrated fertilizer doses for maize. The highest grain yield was recorded in STCR-IPNS equation with 100 q ha-1 target yield (Dharwad -104.8 q ha-1, Belavatgi – 102.3 q ha-1) recording an increase of 67 and 69 per cent over recommended package of practices at Dharwad and Belavatgi, respectively. However, it was found to be on par with Jabalpur STCR equation with 100 q ha-1 target yield and STCR-NPK alone equation with 100 q ha-1 target yield. Higher gross returns were recorded under STCR-IPNS equation with 100 q ha-1 target yield owing to higher grain and stover yields. While STCR equation developed at Jabalpur with 100 q ha-1 target yield recorded higher net returns. The post-harvest soil available NPK indicated better build-up and maintenance of soil fertility by the soil test based fertilizer recommendation under IPNS. Targeting 100 q ha-1 grain yield for maize under STCR approach was found to be ideal in terms of yield, economics and soil fertility maintenance in vertisols of Karnataka. The fertilizer prescription equations developed for maize under IPNS can be recommended for vertisols of Northern Karnataka for achieving target yield of 100 q ha-1 with sustained soil fertility and it can be extrapolated to other agro-climatic zones of Karnataka on similar and allied soil types.
Effect of Indole-3-Butyric Acid on Growth of V-1 Mulberry Cuttings with Varying Number of Buds in Bangalore
Authors: Pooja H. S. , Sadatulla Fatima
Published: December 2022

The present study was conducted in Bangalore. It aims at studying the effect of different concentrations of indole-3-butyric acid (IBA) (1000, 2000 and 3000 ppm) on V-1 mulberry cuttings with varying number of buds (one, two, three and four) consist of twelve treatments which were replicated thrice in Factorial CRD. The results on interaction effect of various concentration of  IBA on mulberry cuttings with varying number of buds recorded best results in three budded cuttings treated with 3000 ppm of IBA regarding number of sprouted cuttings (14.67) and survival percentage (96.66%) of the saplings. Number of leaves (10.60) and length of shoot (26.63 cm) was maximum in two budded cuttings treated with 3000 ppm of IBA and the results of this interaction were on par with three budded cuttings treated with 3000 ppm of IBA. Whereas, one budded cutting without IBA treatment recorded minimum number of sprouted cuttings (9.67), survival percentage (43.33%), number of leaves (5.67) and length of shoot (21.43 cm). From the present experiment, we can recommend to use two budded cuttings treated with 3000 ppm of IBA instead of three budded cuttings treated with 3000 ppm of IBA.
Morphological Characterization and Germination-Based Screening for Cold Stress Response of Vigna radiata L.
Authors: Manasa S. Lekshmi , Panigrahy M. , Panigrahi Kishore C. , Rout Gyana Ranjan
Published: December 2022

Aims: Morphological characterization and germination based screening for cold stress response of  Vigna radiata, was performed to identify the cold resistant genotypes.

Methodology: Augmented design experiment was performed to characterize 204 mungbean genotypes under field condition based on 24 DUS characterization. A germination-based screening at 10°C was performed in a total of 204 germplasms in a plant growth chamber to identify the cold responsive genotypes. Seeds were soaked in water for 6h in the dark under normal temperature and imposed cold stress (100C) for 2, 4, 6, 8 days and further transferred to control temperature  (220C) for  recovery.

Results: On the basis of the 24 DUS characterizations of 204 mungbean genotypes are classified into three major clusters.  Highest number of genotypes in cluster I (113 genotypes), followed by 81 genotypes in cluster II and least number (10) of genotypes in cluster III. Based on cold stress study  and biplot analysis showed that germination percentage, germination rate index, Timson’s index, mean germination time and coefficient of velocity of germination to be more influential and  categorized into three groups having 11 genotypes are resistant, 135 genotypes are susceptible, and 58 genotypes are intermediate.  Biochemical analysis showed that the tolerant genotype having increased chlorophyll, carotenoid and MDA content and oxidative enzyme activity as compared with susceptible and intermediate genotypes under cold stress. 

Conclusion: The present study identified 11 genotypes having cold resistant and may be used for breeding program.
Bioferlizing and Nematodes Control Potentials of Four Native Isolates of Arbuscular Mycorrhizal Fungi on Sweet Pepper (Capsicum annuum) in Togo
Authors: Atti Tchabi , Blaise M'boumba Etienne , Nicolas Olowotche , Pana Kadanga
Published: December 2022

Aims: The aim of the study was to investigate the effectiveness of four isolates of the native Arbuscular Mycorrhizal Fungus (AMF) in improving pepper plant yield as well as to assess their potential for the control of nematodes.

Study Design: The experimental set up consisted of a Completely Randomized Block Design with 5 treatments corresponding to the four isolates of AMF– BEN10, GM142, 472, and WA330 – tested in comparison with the untreated plants as a control treatment.

Place and Duration of Study: The study was conducted in 2020 from June to September « at the Research Station of the Faculty of Agronomy, University of Lomé, Togo».

Methodology: The seeds of pepper were inoculated with the four AMF isolates in the nursery. Six weeks after, the seedlings were transplanted on 3mx6m beds. Several growth parameters such as the number of leaves and branches, plant height, number of flower buds and fruit weight were recorded each three weeks after transplantation. Nematode density was assessed four times (before transplanting, at the flowering, during fruiting, and after the last harvest of pepper fruits).

Results: The AMF increased significantly the marketable pepper fruit weight by 39%, and reduced significantly the root nematode density by 20-34%. A positive correlation (P<0.0001; r = 0.816) was observed between the mycorrhization frequency and mycorrhization intensity, the former was varied from 70% to 91% and the latter from 60% to 85%. The plant height, the number of leaves, the branches and the number of flower buds were not affected by AMF inoculation.

Conclusion: The present study showed the potential of AMF to be considered alternative candidate to chemical fertilizers and pesticides for sustainable production of sweet pepper in Togo.
Modeling and Simulation of Carbon Dioxide Gas Reactive Desorption Process with Piperazine Promoted Diethanolamine Solvent in Sieve Tray Column
Authors: Nisa Nur Ihda Farikhatin , Balqis Nabila Farras , Mukhlish Muhammad Anshorulloh , Altway Ali , Mahfud Mahfud
Published: December 2022

Carbon dioxide (CO2) is an acidic and corrosive gas, and the presence of this gas in the piping system can cause various problems in the industrial sector. Therefore, the CO2 must be separated from the gas stream. One of the CO2 gas separation processes from the gas stream is carried out in a CO2 removal unit, where a desorption unit serves as a solvent regeneration step. Therefore, this study aims to develop a rate-based model and simulation of the reactive desorption process of CO2 gas in a sieve tray column. The rate-based model in the reactive desorption process of CO2 gas is based on film theory, the liquid in the tray is assumed completely agitated due to gas bubbling, the flow pattern of gas is plug flow, and the effect of the reaction on the mass transfer follows the enhancement factor concept. The number of trays used in this study was 20. In addition, the effect of several variables, such as: desorber pressure, rich amine temperature, rich amine flow rate, and reboiler load, was also assessed on the CO2 stripping efficiency. The accuracy of our prediction model is 1.34% compared with industrial plant data. Compared with the chemical engineering simulator simulation results, the average deviation is 4%. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Conformational changes in C1q upon binding to IgG oligomers
Authors: Vandenberg Robert J. , Easterbrook-Smith Simon B.
Published: July 2002

The interaction between C1q and immune complexes is inhibited by 1‐anilino‐8‐naphthalenesulfonate (ANS) in the concentration range of 2–4 mM. ANS binds to C1q with a 20‐fold higher affinity than to IgG [(1986) Mol. Immunol. 23, 39–44] and therefore it is possible to label only C1q with ANS in the presence of IgG. Under such conditions no inhibition is observed. Addition of monomer IgG to a solution of C1q‐bound ANS did not significantly after the fluorescence of the ANS. However when oligomeric IgG was added there was a 2‐fold increase in fluorescence over the same IgG concentration range. When C1q was pretreated with diethylpyrocarbonate there was little change in the fluorescence when IgG oligomers were added to C1q:ANS solutions. These results suggest that C1q undergoes conformational changes upon binding to IgG oligomers.
Tamoxifen inhibits uptake and metabolism of ethanolamine and choline in multidrug‐resistant, but not in drug‐sensitive, MCF‐7 human breast carcinoma cells
Authors: Kiss Zoltan , Crilly Karan S
Published: July 2002

Tamoxifen (TAM), a widely used agent in the hormonal therapy of breast cancer, is also an antagonist of P‐glycoprotein (P‐gp), a cell surface protein which confers drug resistance to cells. Here we report that in an estrogen receptor‐deficient multidrug‐resistant subline of MCF‐7 human breast carcinoma cells (MCF‐7/MDR), but not in the parent drug‐sensitive cells (MCF‐7/WT), clinically relevant concentrations (1–5 μM) of TAM inhibited the uptake and phosphorylation of ethanolamine and choline. These inhibitory effects resulted in decreased synthesis of the corresponding phospholipids. In view of the known dependence of P‐gp function of phosphatidylethanolamine (PtdEtn), inhibition of PtdEtn synthesis may represent an additional mechanism by which TAM inhibits P‐gp‐mediated drug efflux.
Molecular evolution of receptors for eicosanoids
Authors: Toh Hiroyuki , Ichikawa Atsushi , Narumiya Shuh
Published: July 2002

The amino acid sequences of the receptors for various prostaglandins, thromboxane and lipoxin, which belong to the rhodopsin family, were aligned, and a phylogenetic tree was constructed to infer the evolutionary history of the arachidonic acid cascade. The obtained tree suggested that the origin of the cyclooxygenase pathway was different from that of the lipoxygenase pathway. The receptors involved in the cyclooxygenase pathway constructed an independent cluster, but the lipoxin A4 receptor, which is involved in the lipoxygenase pathway, belonged to the cluster of peptide receptors. The primitive form of the cyclooxygenase pathway had been a signal transduction system composed of prostaglandin E2 and its receptor associated with cAMP metabolism.
Arachidonic acid binds to apolipoprotein D: implications for the protein's function
Authors: Morais Cabral João H. , Atkins Gordon L. , Sánchez Luis M. , López-Boado Yolanda S. , López-Otin Carlos , Sawyer Lindsay
Published: July 2002

The lipocalin apolipoprotein D (ApoD) is associated in human plasma with lecithin‐cholesterol acyl transferase. It has also been found in high concentration in the fluid of gross cystic disease of the mammary gland. Using protein fluorescence quenching, it is shown that ApoD binds arachidonic acid (K
aof 1.6 × 108M−1) and as previously known progesterone (K
aof 2.5 × 106M−1), but neither cholesterol nor any of the other prostanoid molecules examined had measurable affinity. This specific binding of arachidonate, also observable directly, suggests a role for ApoD in the mobilisation of Arachidonic acid, and hence prostaglandin synthesis.
Alternative splicing of the human Shaker K+ channel β1 gene and functional expression of the β2 gene product
Authors: McCormack Ken , McCormack Tom , Tanouye Mark , Rudy Bernardo , Stühmer Walter
Published: July 2002

Mammalian voltage‐activated Shaker K+ channels associate with at least three cytoplasmic proteins: Kvβ1, Kvβ2 and Kvβ3. These β subnunits contain variable N‐termini, which can modulate the inactivation of Shaker α subunits, but are homologous throughout an aldo‐keto reductase core. Human and ferret β3 proteins are identical with rat β1 throughout the core while β2 proteins are not; β2 also contains a shorter N‐terminus and has no reported physiological role. We report that human β1 and β3 are derived from the same gene and that β2 modulates the inactivation properties of Kv1.4 α subunits.
A novel covalent modification of nitrogenase in a cyanobacterium
Authors: Gallon John R. , Cheng Jiujun , Dougherty Lisa J. , Gallon Victoria A. , Hilz Helmuth , Pederson Dennis M. , Richards Helen M. , Rüggeberg Sabrina , Smith Christopher J.
Published: July 2002

In extracts of the unicellular cyanobacterium Gloeothece, the Fe‐protein of nitrogenase can be separated by SDS–PAGE into two antigenically identifiable components. Unlike the situation in photosynthetic bacteria such as Rhodospirillum rubrum, these two forms do not arise from covalent modification of the protein by ADP‐ribosylation. Rather, the Fe‐protein of Gloeothece nitrogenase is subjected to modification by palmitoylation.
PAI‐1 stability: the role of histidine residues
Authors: Mångs Helena , Sui Guang-Chao , Wiman Björn
Published: July 2002

The role of the 13 histidine residues in plasminogen activator inhibitor 1 (PAI‐1) for the stability of the molecule was studied by replacing these residues by threonine, using site‐directed mutagenesis. The generated mutants were expressed in Escherichia coli, purified and characterized. All variants had a normal activity and formed stable complexes with tissue‐type plasminogen activator. Most of these PAI‐1 variants displayed a similar pH‐dependency in stability as wild‐type PAI‐1, with increased half‐lives at lower pH. However, the variant His364Thr had a half‐life of about 50 min at 37°C and had almost completely lost its pH‐dependency. Therefore, our data suggest that His364, in the COOH‐terminal end of the molecule might be responsible for the pH‐dependent stability of PAI‐1.
A fat body derived protein is selectively sulfated in the stick insect ovary by transcytosis through the follicular epithelium
Authors: Giorgi Franco , Falleni Alessandra , Cecchettini Antonella , Gremigni Vittorio
Published: July 2002

With the onset of vitellogenesis, the follicular epithelium overlying the oocyte in stick insect ovarioles becomes highly polarized and patent by formation of wide intercellular spaces. The aim of the present study was to provide experimental support to the notion that the follicular epithelium in this insect species may be involved in transcytosis. Data demonstrate that the follicular epithelium carries out sulfo‐conjugation of a 85 kDa fat body derived protein by allowing it to transit from one cell pole to another. Along the basal end, follicle cells branch into a number of cytoplasmic finger‐like projections. At the opposite end facing the oocyte they taper off into lance‐head shapes. Different vesicular elements are evident at both these extremities. In vivo exposure to horseradish peroxidase shows that the vesicular elements present along the apical end provide an endocytic entry. In contrast, those present along the basal end are labeled with sodium [35S]‐sulfate, suggesting that they may be exocytic vesicles containing a sulfo‐conjugated secretory product. In vivo exposure to sodium [35S]‐sulfate caused radioactivity to appear over the Golgi apparatus and some nearby vesicles of the follicle cell cytoplasm, including the exocytic vesicles. The intracellular pathway of the follicle cells was also examined by immunogold labeling using a monoclonal antibody raised against a 85 kDa fat body derived protein. Under these conditions, gold particles were consistently detected over the Golgi apparatus and the vesicular elements lying along both poles of the follicle cell membrane. Based on this evidence, it is concluded that follicular cells in stick insect ovarioles are endowed with the ability to undergo transcytosis by providing an endocytic entry along the apical end and by releasing exocytically a sulfo‐conjugated 85 kDa protein along the baso‐lateral domain of the follicle cell membrane.
Internal and External Mass Transfer in Biofilms Grown at Various Flow Velocities
Authors: Beyenal Haluk , Lewandowski Zbigniew
Published: July 2002

It appears that biofilms arrange their internal structure according to the flow velocity at which they are grown, which affects the internal mass transfer rate and microbial activity. In biofilms grown at various flow velocities we determined the vertical profiles of the local relative effective diffusivity (termed Dl) at several locations within each biofilm. From these profiles we calculated the surface‐averaged relative effective diffusivity (termed Dsa) at various distances from the bottom and plotted it against these distances. The Dsa decreased linearly toward the bottom, forming well‐defined profiles that were different for each biofilm. The gradients of these profiles were multiplied by the diffusivity of oxygen, ζ = Dw d Dsa/d z, and plotted versus the flow velocity at which each biofilm was grown. The gradients were low at flow velocities below 10 cm/s, reached a maximum at a flow velocity of 10 cm/s, and decreased again at flow velocities exceeding 10 cm/s. The existence of a maximum indicates a possibility that two opposing forces were affecting the slope of the profiles. To explain these observations we hypothesized that biofilms, depending on the flow velocity at which they are grown, arrange their internal architecture to control (1) the nutrient transport rate and (2) the mechanical pliability needed to resist the shear stress of the water flowing past them. It appears that biofilms attempt to satisfy the second goal first, to increase their mechanical strength, and that they do so at the expense of the nutrient transfer rate to deeper layers. This strength increase is associated with an increase in biofilm density, which slows down the internal mass transport rate. Biofilms grown at low flow velocities exhibit low density and high effective diffusivity but cannot resist higher shear stress, whereas biofilms grown at higher flow velocities are denser and can resist higher shear stress but have a lower effective diffusivity.
Non‐enzymatic Browning in Single‐Strength Reconstituted Citrus Juice in TetraBrik Cartons
Authors: Roig M. G. , Bello J. F. , Rivera Z. S. , Lloyd L. L. , Kennedy J. F.
Published: July 2002

In freshly produced commercial citrus juice, aseptically filled in a TetraBrik carton, it has been demonstrated that non‐enzymatic browning was mainly due to carbonyl compounds formed from l‐ascorbic acid degradation. At different storage temperatures (4−37 °C), this, browning showed first‐order kinetics with higher rate constants as temperature was increased. An assessment of the degree of browning as a function of time in the presence of additives (sodium metabisulfite, sodium tripolyphosphate, (carboxymethyl)cellulose and sorbitol) showed that the addition of sodium metabisulfite substantially reduced browning, particularly at the higher storage temperatures of 76 and 105 °C where a greater accumulation of 5‐(hydroxymethyl)furfuraldehyde was observed.
β‐Lactamase Recovery from E. coli Cell Lysate via Two‐Phase Electrophoresis
Authors: Oehler Ryan D. , Clark William M.
Published: July 2002

β‐Lactamase was recovered from Escherichia coli cell lysate by a novel cell debris removal method using two‐phase electrophoresis. The cells were harvested by centrifugation after fermentation, resuspended in a low ionic strength electrophoresis buffer, lysed, and combined with a poly(ethylene glycol)/dextran aqueous two‐phase system in the same buffer. The cell lysate was subjected to a 40 V/cm electric field oriented perpendicular to the phase interface for 90 min. Experiments were conducted both with and without a nucleic acid precipitation step using poly(ethylene imine) (PEI). For PEI‐treated lysate at pH 5, the positively charged β‐lactamase was directed to the upper phase, while negatively charged contaminants (including cell debris, nucleic acid/PEI precipitates, and negatively charged proteins) were directed to the lower phase with the applied field. β‐Lactamase yield in the upper phase was 81%, while cell debris and nucleic acids partitioned almost exclusively to the lower phase. For untreated lysate, β‐lactamase did not move in the electric field due to strong interaction with nucleic acids in solution.
Production of Retroviral Vectors for Gene Therapy with the Human Packaging Cell Line FLYRD18
Authors: Gerin Patrick A. , Searle Peter F. , Al‐Rubeai Mohamed
Published: July 2002

The development of gene therapy is hampered by the difficulty of producing large stocks of retroviral vectors at high titer. This study aimed to improve culture conditions and to intensify the production of retroviruses by FLYRD18, a packaging cell line derived from the HT1080 human fibrosarcoma line. Batch virus production proved to be feasible in unsupplemented basal medium and provided significantly higher titers and productivities than medium supplemented with 10% serum. For longer‐term production, however, AIM‐V complete serum‐free medium and basal medium supplemented with 2% serum gave superior results. Serum supplementation should nevertheless be optimized to take into account the presence of inhibitors of viral production. In monolayer cultures with 0.2 mL/cm2, the cell concentration was increased up to 2 × 106 cells/mL without loss of cell productivity. A semicontinuous production process, which enables the collection of larger amounts of viruses from the same culture, has also been successfully used. Suspension culture processes were prevented by the anchorage dependency of the FLYRD18 cell line. Microcarrier cultures were able to produce viruses but will require further investigation and optimization for their performance to become competitive with monolayer cultures. In the course of this study, more than a 10‐fold increase of titer has been achieved.
Tritiated photoactivatable analogs of the native human thrombin receptor (PAR‐1) agonist peptide, SFLLRN‐NH2
Authors: Elliott J.T. , Hoekstra W.J. , Derian C.K. , Addo M.F. , Maryanoff Bruce E. , Ahern D.G. , Prestwich G.D.
Published: July 2002

Abstract: Six photoactivatable analogs of the human thrombin receptor activating peptide (TRAP), SFLLRN‐NH2, were synthesized by substituting the photoactive amino acid, p‐benzoylphenylalanine (Bpa), into each position of the peptide sequence. Platelet aggregation assays indicated that the peptides with Bpa substitutions at positions 3 to 6 retained agonist activity. These peptides were prepared in tritiated form as potential thrombin receptor photoaffinity labels. The [3H]Bpa‐containing analogs were constructed by resynthesizing the peptides with the amino acid, 4‐benzoyl‐2′,5′‐dibromophenylalanine (Br2Bpa), and subjecting the purified peptides to Pd‐catalyzed tritiodebromination. The radiochemical yields for the reductive tritiation were < 2% for peptides with [3H]Bpa in the third and fourth positions, and between 7 and 16% for the peptides with substitutions at the fifth and sixth positions. The low yields were due to over‐reduction of the Bpa carbonyl group and nonspecific degradation during reductive tritiation. This report describes the first use of Br2Bpa for the preparation of tritiated photoactivatable peptides.
Purine and pyrimidine metabolism in cultured white spruce (Picea glauca) cells: Metabolic fate of 14C‐labeled precursors and activity of key enzymes
Authors: Ashihara Hiroshi , Stasolla Claudio , Loukanina Natalia , Thorpe Trevor A.
Published: July 2002

In order to examine the biosynthesis, interconversion, and degradation of purine and pyrimidine nucleotides in white spruce cells, radiolabeled adenine, adenosine, inosine, uracil, uridine, and orotic acid were supplied exogenously to the cells and the overall metabolism of these compounds was monitored. [8‐14C]adenine and [8‐14C]adenosine were metabolized to adenylates and part of the adenylates were converted to guanylates and incorporated into both adenine and guanine bases of nucleic acids. A small amount of [8‐14C]inosine was converted into nucleotides and incorporated into both adenine and guanine bases of nucleic acids. High adenosine kinase and adenine phosphoribosyltransferase activities in the extract suggested that adenosine and adenine were converted to AMP by these enzymes. No adenosine nucleosidase activity was detected. Inosine was apparently converted to AMP by inosine kinase and/or a non‐specific nucleoside phosphotransferase. The radioactivity of [8‐14C]adenosine, [8‐14C]adenine, and [8‐14C]inosine was also detected in ureide, especially allantoic acid, and CO2. Among these 3 precursors, the radioactivity from [8‐14C]inosine was predominantly incorporated into CO2. These results suggest the operation of a conventional degradation pathway. Both [2‐14C]uracil and [2‐14C]uridine were converted to uridine nucleotides and incorporated into uracil and cytosine bases of nucleic acids. The salvage enzymes, uridine kinase and uracil phosphoribosyltransferase, were detected in white spruce extracts. [6‐14C]orotic acid, an intermediate of the de novo pyrimidine biosynthesis, was efficiently converted into uridine nucleotides and also incorporated into uracil and cytosine bases of nucleic acids. High activity of orotate phosphoribosyltransferase was observed in the extracts. A large proportion of radioactivity from [2‐14C]uracil was recovered as CO2 and β‐ureidopropionate. Thus, a reductive pathway of uracil degradation is functional in these cells. Therefore, white spruce cells in culture demonstrate both the de novo and salvage pathways of purine and pyrimidine metabolism, as well as some degradation of the substrates into CO2.
Pepper gene encoding a basic pathogenesis‐related 1 protein is pathogen and ethylene inducible
Authors: Jin Kim Young , Kook Hwang Byung
Published: July 2002

A new basic pathogenesis‐related (PR)‐1 cDNA (CABPR1) was isolated from a cDNA library of pepper leaves infected with Xanthomonas campestris pv. vesicatoria. The full‐length clone contains an open reading frame of 531 nucleotides encoding 177 amino acid residues with a predicted molecular mass of 20241 and pI of 8.1. The deduced amino acid sequence of CABPR1 has a high level of identity with PR‐1 proteins from tobacco and tomato. Expression of the CABPR1 mRNA was greatly induced in an incompatible interaction of pepper leaves with X. campestris pv. vesicatoria. Accumulation of the basic PR‐1 mRNA in the bacteria‐infected leaves was intrinsically associated with the induction of ethylene biosynthesis. Treatment with 1‐aminoethoxyvinylglycine, an inhibitor of ethylene biosynthesis, strongly suppressed the induction of PR‐1 mRNA expression in the bacteria‐infected leaves. These data suggest that ethylene may function as a strong signal elicitor in the activation of PR‐1 genes, eventually mediating the plant defence response. Phytophthora capsici infection also distinctly stimulated ethylene biosynthesis, together with accumulation of PR‐1 mRNA. Expression of the basic PR‐1 mRNA was also induced in the pepper leaves by treatment with dl‐β‐amino‐n‐butyric acid or salicylic acid, but not by wounding. Treatment with methyl jasmonate, in combination with salicylic acid, strongly induced the PR‐1 transcripts. The basic PR‐1 gene expression occurred in untreated roots, flowers and green fruit of pepper but not in leaf, stem or red fruit.
Functional site of endogenous phospholipase A2 inhibitor from python serum
Authors: Thwin Maung‐Maung , Satish Ramapatna L. , Chan Steven T. F. , Gopalakrishnakone Ponnampalam
Published: July 2002

The functional site of ‘phospholipase A2 inhibitor from python’ (PIP) was predicted based on the hypothesis of proline brackets. Using different sources of secretory phospholipase A2 (sPLA2s) as enzyme, and [3H]arachidonate‐labelled Escherichia coli as substrate, short synthetic peptides representing the proposed site were examined for their secretory phospholipase A2 (sPLA2) inhibitory␣activity. A decapeptide P‐PB.III proved to be the most potent of the tested peptides in inhibiting sPLA2 enzymatic activity in vitro, and exhibited striking anti‐inflammatory effects in␣vivo in a mouse paw oedema model. P‐PB.III inhibited the enzymatic activity of class I, II and III PLA2s, including that of human synovial fluid from arthritis patients. When tested by ELISA, biotinylated P‐PB.III interacted positively with various PLA2s, suggesting that the specific region of PIP corresponding to P‐PB.III, is likely to be involved in the PLA2–PLI interaction. The effect of P‐PB.III on the peritoneal inflammatory response after surgical trauma in rats was also examined. P‐PB.III effectively reduced the extent of postsurgical peritoneal adhesions as compared to controls. sPLA2 levels at seventh postoperative day in the peritoneal tissue of P‐PB.III‐treated rats were also significantly reduced (P < 0.05) in comparison to those of the untreated controls. The present results shed additional insight on the essential structural elements for PLA2 binding, and may be useful as a basis for the design of novel therapeutic agents.
Hepatitis B vaccinees may be mistaken for confirmed hepatitis B surface antigen‐positive blood donors
Authors: Dow B. C. , Yates P. , Galea G. , Munro H. , Buchanan I. , Ferguson K.
Published: July 2002

Background and Objectives Hepatitis B surface antigen (HBsAg) test sensitivities have gradually increased, and neutralizable weak HBsAg‐positive donations, with no other hepatitis B virus (HBV) markers, have occasionally been found in our donor population. On investigation, these donors have admitted to receiving hepatitis B vaccine up to 5 days previously. A study was therefore initiated to monitor HBsAg reactivity amongst volunteers after receiving their first dose of hepatitis B vaccine.

Materials and Methods Eight volunteers were tested using three HBsAg assays (Abbott Auszyme, Ortho HBsAg‐3 and Abbott/Murex GE34/36) on days 0, 3, 5, 7 and 10 after administration of hepatitis B vaccine.

Results Two HBsAg tests (Abbott Auszyme and Ortho HBsAg‐3) did not detect HBsAg reactivity amongst the volunteers, although the Abbott Auszyme test results reached 70–80% of the manufacturer’s cut‐off at day 3 in two volunteers. The most recently launched assay (Abbott/Murex GE 34/36) detected seven (87%) of the eight volunteers as HBsAg reactive on day 3, and two (25%) volunteers were still reactive on day 5.

Conclusion The Abbott/Murex GE 34/36 assay demonstrated HBsAg reactivity in most volunteers on day 3 and in some on day 5 after vaccination. It is therefore recommended that individuals who have recently been vaccinated with hepatitis B be deferred from blood donation for at least 7 days.