bluuebunny/crossref_metadata_2025 huggingface dataset:
A Hybrid Numerical Framework for Simulation of Ships Maneuvering in Waves
Authors: White Paul F. , Piro Dominic J. , Knight Bradford G. , Maki Kevin J.
Published: July 2021

The maneuvering characteristics of a surface ship play a critical role in the safety of navigation both in port and in an open seaway, and are vital to the overall operational ability of the ship. The vast majority of maneuvering analyses for ships have been performed under the assumption of calm water, yet ships mostly operate in waves. Understanding of maneuvering in waves is limited by the complexity of the problem and the challenges of performing physical experiments and numerical simulations. In this work, a new fast-running method that allows for the study of maneuvering in waves is formulated. The newly formulated approach is categorized as a “hybrid method,” taking its name from the multiple numerical methods and force models used to predict the total hydrodynamic force acting on the vessel maneuvering in waves. The framework presented here uses a combination of Computational Fluid Dynamics, a linear time-domain boundary element method, and a propeller-force model for efficient computation of the total hydrodynamic force.

Introduction

The maneuverability of a ship is directly related to its ability to safely perform the tasks for which it was designed and built. In addition to maneuvering at low speed in calm-water conditions, vessels are also required to execute challenging maneuvers such as taking evasive action or maintaining course in adverse weather. The performance of the vessel must be adequate in various water depths, in confined or open water, and in a multitude of environmental conditions. Consequently, predictive tools are necessary in ship design to evaluate the maneuvering response of vessels in both calm water and in waves.
The Effect of Air Lubrication on a Flat Plate at Varying Angles of Trim With Regard to Drag Reduction
Authors: Murphy Sean P. , Spillane Colin T.
Published: July 2021

One of the driving factors of technological development in ship design is the reduction of fuel consumption. One way to reduce fuel consumption is to reduce the total resistance experienced by a vessel. The methods of resistance reduction covered in this document are Air-layer-drag-reduction (ALDR) and Bubble Drag Reduction (BDR). This research, conducted in Webb Institute’s circulating flow channel, investigates the applications of ALDR and BDR to a flat plate. These tests measured frictional resistance at varying air flow volume and angles of trim over a range of flow speeds. Results from these tests offer compelling evidence that ALDR is an effective method of reducing frictional resistance.
Human Powered Submarine 2013
Authors: Thompson Mike
Published: July 2021

The design cycle began with a very new team with only few senior members with some experience from the year prior. It was decided early that our goals as a team were to apply our knowledge gained from the classroom into design exercises with a heavy focus on research. Much of the effort was spent early on developing a web site, www.uw-hps.com, and a sales brochure for use with fundraising and public awareness. At the same time other members were busy developing designs and formulating the research to be conducted.
A Comparative Cost Analysis of Floating Wind Turbine Platforms
Authors: Dwyer Daniel A. , Emmerik Justin C.
Published: July 2021

This thesis presents a cost-of-energy (COE) analysis comparing three types of floating wind turbine platforms—spar-buoy, semi-submersible, and tension-leg platform (TLP)— based on existing commercial designs. The analysis develops the COE of a 500-MW reference wind plant at a reference offshore location using a merit-based criterion that integrates both lifecycle cost and turbine energy production. A sensitivity study examines how fluctuations in site-dependent operating parameters and fabrication cost factors affect results. The analysis demonstrates that while the COE of a floating wind plant can vary across a wide range ($0.10 to $0.22/kWh), the relative COE performance of the three platforms does not change. The TLP consistently enables the lowest COE across a range of operating parameters as a result of its comparatively low steel weight and less expensive mooring and anchoring system. The percent differences between the COE enabled by the TLP and that of the spar-buoy and semi-submersible are 4% and 19%, respectively, at the baseline reference site.
La competencia creativa entre el alumnado de los grados en Publicidad y Relaciones Públicas en España y su adecuación a las demandas del sector profesional
Authors: Sanz-Marcos Paloma , González-Oñate Cristina , Jiménez-Marín Gloria
Published: July 2021

Este trabajo se propone realizar una investigación acerca del desarrollo de la competencia creativa por parte del alumnado durante su formación en el Grado en Publicidad y Relaciones Públicas. Concretamente, se persigue conocer si el estudio e impulso de la creatividad se adecua a las demandas del sector profesional publicitario. Para ello se ha llevado a cabo una metodología de triple enfoque basada en un análisis de contenido de los planes de estudio, un cuestionario dirigido a alumnos egresados y un panel de expertos formado por académicos pertenecientes al Grado en Publicidad y RR.PP. Los resultados indican que, si bien la formación de estos graduados parece adecuada en términos generales, la formación recibida en torno a la creatividad parece insuficiente para dar respuesta a las demandas del mercado laboral. Algunos de los factores que explican estas tendencias son el exceso de integración de competencias digitales como consecuencia de la renovación del grado o la incapacidad del profesorado para implementar metodologías creativas en el aula debido a las exigencias profesionales a las que se ven sometidos. Es por ello por lo que se recomienda una transformación de los planes de estudio universitarios del Grado en Publicidad y Relaciones Públicas para atender a las demandas laborales vinculadas al ejercicio de la creatividad publicitaria en España.
Evaluación de la transparencia en el periodismo de datos de referencia
Authors: Córdoba-Cabús Alba , García-Borrego Manuel
Published: July 2021

La aprobación de leyes que garantizan el acceso a la información y fomentan la transparencia de las instituciones propulsó el establecimiento del periodismo de datos como práctica periodística. Esta especialización surge en favor de la transparencia, por lo que incorporar indicadores que resten opacidad a la industria mediática se plantea como necesario para añadir credibilidad y calidad a la historia publicada. Esta investigación se propone examinar el nivel de transparencia en las mejores historias de periodismo de datos reconocidas a nivel mundial publicadas entre 2018 y 2019. Asimismo, se pretende comprobar si la tipología de las fuentes y de los datos inciden en la opacidad y clasificar las piezas en función del grado de transparencia. A través de un análisis descriptivo e inferencial de los proyectos candidatos a los Data Journalism Awards 2019 y a los Sigma Awards 2020 (n=80) se detecta un amplio margen de mejora en cuanto a la transparencia. Mientras que en la mayoría de las piezas se menciona directamente la fuente (91,4%), el acceso a la metodología (48,8%) y a los datos en sí (20%) resulta muy limitado. Del análisis de correspondencias múltiple se desprenden tres grupos de historias, buena parte de las cuales pertenecen al nivel más opaco. Entre otras constataciones, se concluye que el tipo de fuentes y de datos incorporados no influye en el nivel de transparencia.
La Isla Etaria. Tercera Edad y Medios de Comunicación.
Authors: Otero Sofía
Published: July 2021

La Isla Etaria. Tercera Edad y Medios de Comunicación (2021), coordinado por Virginia Guarinos, es un libro divulgativo sobre el tratamiento del colectivo de personas de más de 65 años en los medios audiovisuales. A través de capítulos independientes, el equipo de investigación AdMIRA construye un compendio de textos sobre la representación de este colectivo etario de edad avanzada, en ámbitos como la publicidad, el cine y la radio, entre otros. Además, se complementa la publicación con el recurso transmedia de podcasts radiofónicos homónimos publicados en RadiUS.
La creatividad en la enseñanza como factor de aproximación de la universidad a los desafíos sociales
Authors: Fernández Souto Ana Belén , Balonas Sara
Published: July 2021

Se reflexiona sobre  la creatividad como respuesta a los nuevos desafíos a las que las sociedades están haciendo frente:  se pretende repensar sobre las fórmulas que la enseñanza universitaria puede utilizar para estimular esta capacidad .

El trabajo se centra en la idea defendida por Wallas, que consideraba la creatividad como el resultado de un proceso evolutivo que permitía a los humanos adaptarse rápidamente a alteraciones de ambientes (1926).  Teniendo en cuenta  la pandemiao, parece necesario entender que los retos que afrontan las organizaciones deben ser asumidas también por las entidades académicas, por lo que las instituciones de enseñanza superior deben estar preparadas para formar profesionales aptos para tomar parte de la solución del problema. Así, ¿qué competencias se exigen al nivel de formación?, ¿las universidades presentan una oferta de estudios orientada al ejercicio de la creatividad ?, ¿qué características deben incluirse en la formación del profesional de comunicación dentro de su formación ?

Se propone una revisión del concepto de creatividad  y se presenta un mapeo de la oferta formativa universitaria en Portugal y España para entender si estas instituciones  están preparadas para formar profesionales alineados con los requerimientos del nuevo panorama social.

Se concluye que la presencia de la creatividad en los planes de estudio de las principales universidades estudiadas es residual y se limita a las especialidades de comunicación, lo que evidencia que el sistema de educación superior sigue viviendo de espaldas a las necesidades profesionales.
Canales de vídeo de doblaje paródico en YouTube en España. Los casos de Loulogio, Desahogada, Korah, Keunam y HDub
Authors: Trabadela-Robles Javier , Corral-Motino Diego Jesús
Published: July 2021

Las posibilidades creativas que ofrecen los medios sociales son ilimitadas. Entre ellas está el humor en clave de parodia. Los doblajes paródicos en YouTube han adquirido una relevancia considerable durante la última década, tanto a nivel internacional como en España. El objetivo de este trabajo es estudiar las creaciones paródicas de autores hechas en este medio social desde España. Para ello, se efectúa una selección de creadores, de modo que se realiza un análisis de contenido de los canales de: Loulogio, Desahogada, Korah, Keunam y HDub, quienes han revolucionado el panorama humorístico creando iconos únicos e irrepetibles y logrando grandes cantidades de seguidores y visitas. Entre los resultados destaca que los autores plasman toda su creatividad usando del doblaje de un modo cómico, espontáneo, marcado por la autenticidad y sus estilos claros e inconfundibles. También que en este tipo de vídeos predominan las referencias locales, aunque intentan ser lo más globales posibles para mantener su gran audiencia. Hay diferencias como el distinto nivel de profesionalidad de los autores (en función de sus perfiles reales) y de los primeros vídeos a los actuales, de mucha mayor calidad técnica. En definitiva, cinco comunicadores originales, creativos y con un sentido del humor único.
Personalización, transversalidad y capilaridad: la campaña digital del BNG para las elecciones gallegas de 2020
Authors: Rivas-de-Roca Rubén
Published: July 2021

La crisis del COVID-19 no solo modificó la fecha de los comicios previstos en País Vasco y Galicia, sino que transformó su marco comunicativo. En el caso de las elecciones gallegas de 2020, los resultados reflejan un importante cambio en la configuración de la oposición. El nacionalismo cosechó la mejor representación de su historia de la mano del Bloque Nacionalista Galego (BNG), a la vez que se produjo la desaparición parlamentaria de la izquierda rupturista.Teniendo esto en cuenta, el objetivo de esta investigación es analizar la campaña desarrollada en redes sociales (Facebook, Twitter e Instagram) por el BNG y su líder Ana Pontón, en el sentido de si expusieron estrategias innovadoras que conectaran con la juventud. Este público ha sido el principal votante del BNG de acuerdo con estudios postelectorales. Para lograr ese propósito se lleva a cabo un análisis de contenido que estudia los temas tratados en la campaña. También se valora el impacto cuantitativo en la fase de contienda electoral y los formatos empleados, en este caso a través de un enfoque cualitativo.Como resultado se aprecia una agenda temática plural. La campaña adopta rasgos de personalización política, en la figura de Ana Pontón; transversalidad, al dejar atrás postulados soberanistas; y capilaridad, con un notable peso de las agrupaciones locales. Todas esas estrategias han sido tradicionalmente propias del Partido Popular de Galicia (PPdeG), si bien el BNG semeja aplicarlas buscando nichos de votantes juveniles. El caso analizado demuestra cómo un partido clásico se apropia del espacio digital de la “nueva política”, consiguiendo erigirse en líder de la oposición en un contexto de desmovilización por la pandemia.
El discurso populista de VOX en las Elecciones Generales de 2019: análisis comparativo de las agendas temáticas en televisión y Twitter
Authors: Lava Santos David
Published: July 2021

Las redes sociales y en especial Twitter han configurado nuevas formas de consumir la información política en nuestro país. No obstante, la televisión es todavía una fuente de consumo vicaria en lo que a comunicación política se refiere. Ambos medios, redes y televisión, se consolidan en España como los canales preferidos por la ciudadanía para obtener información de carácter político. El presente artículo tiene como objetivo principal conocer cuáles han sido las causas mediáticas que han llevado al partido de ultraderecha populista, VOX, a establecerse como tercera fuerza política en el Congreso de los Diputados, situándose en número de escaños por delante de Unidas Podemos y justo por detrás del PP (Partido Popular). Para ello, se ha realizado un análisis de contenido con una muestra total de 51 noticias de los informativos nocturnos de TVE y Telecinco, y 264 tuits originales de la cuenta oficial de Twitter del partido, VOX_es. El periodo analizado comprende los días referidos a la campaña electoral del 28 de abril de 2019, y la del 10 de noviembre de ese mismo año. El análisis, entre otras cuestiones, ha permitido confirmar tendencias como la utilización de un discurso claramente populista por parte de VOX en la red social analizada, o la emisión de noticias en los informativos estudiados cuyos temas no se asemejan a los introducidos por VOX en las publicaciones de su cuenta oficial en Twitter.
Tristes por diseño: las redes sociales como ideología
Authors: Navarro Flores Iván Navarro
Published: July 2021

Reseña del libro: Lovink, G. (2019). Tristes por diseño: las redes sociales como ideología. Bilbao: Consonni.
Oculto a simple vista: análisis de las comunicaciones diarias de la Conselleria de Sanidad de la Comunitat Valenciana durante la primera oleada del coronavirus SARS-CoV-2
Authors: Aguar Torres Joaquín , López García Guillermo
Published: July 2021

Este artículo analiza la comunicación de la Conselleria de Sanidad de la Comunitat Valenciana a lo largo de la primera ola de la pandemia del coronavirus SARS-CoV-2. Se trata de un período en el que la población española estuvo sometida a un riguroso confinamiento domiciliario para mitigar la propagación del virus, y donde el interés por adquirir información al respecto de la pandemia era máximo. El objetivo de la investigación es determinar qué mensajes prevalecían en la estrategia de comunicación de la conselleria mediante el análisis de un centenar de notas de prensa, difundidas a lo largo de los meses de febrero a junio de 2020. Es decir, a lo largo de la primera ola de la pandemia en España y de la desescalada que derivó en la "nueva normalidad" que dio fin al confinamiento en el mes de junio. Nuestra hipótesis de partida establece que la Conselleria de Sanidad intentaría minimizar los datos más negativos (contagios, hospitalizados, fallecidos) en su comunicación hacia la ciudadanía y los medios de comunicación, resaltando otros aspectos positivos (como los pacientes recuperados).El análisis combina dos metodologías: un análisis de contenido cuantitativo, basado en palabras clave, de los titulares y subtítulos de las notas de prensa, para analizar los elementos que se buscaba destacar por parte de la conselleria; y un análisis del discurso de las notas de prensa en su conjunto, que permita analizar el relato elaborado por la conselleria a través del cual se aportaba la información. Dicho análisis permite validar nuestra hipótesis, pues muestra cómo tanto los titulares como las notas de prensa en su conjunto resaltaban casi sistemáticamente elementos positivos, mientras los datos adversos eran postergados en una posición subalterna en las noticias.
La Isla Etaria. Tercera edad y medios de comunicación
Authors: Granero Ramos Sara
Published: July 2021

La Isla Etaria, el cuarto volumen de la colección divulgativa de la editorial Readuck, repasa el tratamiento de la tercera edad en los productos audiovisuales actuales. El libro analiza el trato desfavorable que a menudo sufren los mayores de 65 años en su representación, ya sea por su tratamiento desde el paternalismo o directamente por su invisibilización.
ANALYSIS OF NUTRITIONAL STATUS OF PRIMARY SCHOOL CHILDREN IN MONTENEGRO
Authors: Gardašević Novica , Anđelić Milan , Joksimović Marko , Ahmedov Farruh
Published: July 2021

Nutritional analysis is a very important segment in monitoring the growth and development of school-age children. The aim of this study was to define the nutritional status based on the results of previous studies with samples taken from the population of primary school students in Montenegro. The analysis included 11 studies with a total of 8619 respondents of both sexes, which mainly dealt with the assessment of the nutritional status of respondents aged 6 to 15 years. Based on the analysis of the research results, it was determined that malnutrition and obesity are significantly present in children of primary school age of both sexes in Montenegro. Taking into account malnutrition and obesity together, the percentages range from 20-40%, which is typical for the Mediterranean countries of Europe, including Montenegro. Also, it was found that the application of different nutrition assessment standards gives different results that sometimes differ significantly on the same sample of respondents.
Research progress of 10B concentration and distribution measurement in boron neutron capture therapy
Authors: Gao Song , Cao Wen-Tian , Huang Xin-Rui , Bao Shang-Lian ,   Medical Technology Institute of Health Science Center, Peking University, Beijing 100191, China,   School of Physics, Peking University, Beijing 100875, China,   School of Basic Medical Sciences, Peking University, Beijing 100191, China
Published: July 2021

Boron neutron capture therapy (BNCT) is a dual tumor radiotherapy method combining boron-10 containing drugs and heavy ion therapy, which can kill cancer cells with almost no damage to normal cells, and achieve precise cell-scale treatment. However, the BNCT does not really enter into clinical application stage though it has been developed for nearly 70 years. The methods of measuring the concentration distribution of boron-10 containing drugs in vivo cannot meet the clinical needs, which is one of the core problems affecting the effect and safety of clinical application of BNCT. This article reviews the current methods of measuring the concentration distribution of boron-10 drugs, including the invasive estimation methods that have been used in clinical practice, the researching single photon emission tomography (SPECT) method, positron emission tomography (PET) method, nuclear magnetic resonance (NMR) method, etc., and analyzes the advantages and limitations of current methods. Based on the characteristics of the low gyromagnetic ratio of the boron-10 element and the extremely short magnetic resonance transverse relaxation time, the research ideas of ultra-short echo time magnetic resonance boron-10 quantitative imaging are proposed. The feasibility of quantitative measurement of boron-10 distribution in vivo based on ultrashort echo time magnetic resonance imaging is analyzed theoretically.
Genetic variant in 3’ untranslated region of the mouse pycard gene regulates inflammasome activity
Authors: Ritchey Brian , Hai Qimin , Han Juying , Barnard John , Smith Jonathan D
Published: July 2021

Quantitative trait locus mapping for interleukin-1β release after inflammasome priming and activation was performed on bone-marrow-derived macrophages (BMDM) from an AKRxDBA/2 mouse strain intercross. The strongest associated locus mapped very close to the Pycard gene on chromosome 7, which codes for the inflammasome adaptor protein apoptosis-associated speck-like protein containing a CARD (ASC). The DBA/2 and AKR Pycard genes only differ at a single-nucleotide polymorphism (SNP) in their 3’ untranslated region (UTR). DBA/2 vs. AKR BMDM had increased levels of Pycard mRNA expression and ASC protein, and increased inflammasome speck formation, which was associated with increased Pycard mRNA stability without an increased transcription rate. CRISPR/Cas9 gene editing was performed on DBA/2 embryonic stem cells to change the Pycard 3’UTR SNP from the DBA/2 to the AKR allele. This single base change significantly reduced Pycard expression and inflammasome activity after cells were differentiated into macrophages due to reduced Pycard mRNA stability.
Dinámica de cambios de uso de suelo y estimación de CO2 en manglares de la zona Marismas Nacionales, México
Authors: Quintero-Morales Alejandra , Plata-Rocha Wenseslao , Olimón-Andalon Vicente , Monjardín-Armenta Sergio , Nemiga-Antonio Xanath
Published: July 2021

En los últimos años, se ha deforestado el 20% de manglar a nivel mundial. México es de los países con mayor pérdida de superficie de mangle, algo que contribuye a las emisiones de CO2 e impulsa el cambio climático. Sin embargo, falta conocimiento sobre los factores que influyen en la pérdida y la ganancia del manglar, las emisiones de CO2, y la dinámica de usos de suelo y cobertura vegetal a escala local y regional. Por tanto, los objetivos de este estudio fueron analizar la dinámica de uso de suelo en la zona de Marismas Nacionales (México) durante el periodo 1981–2015, determinar la tasa de deforestación y degradación anual del manglar y estimar las emisiones de CO2 derivadas de estos procesos utilizando técnicas de información geográfica. Para determinar los cambios de uso de suelo, con la matriz de tabulación cruzada, se adquirieron diversos parámetros de cambio que permitieron generar una ecuación para estimar la tasa de deforestación y degradación. Con los datos del Inventario Nacional de Emisiones de Gases y Compuestos de Efecto Invernadero (México), se estimaron las emisiones y las absorciones de CO2 (equivalente, CO2e) promovidas por deforestación, degradación, reforestación y recuperación natural de manglares. Para el periodo 1981–2005, la emisión estimada fue de 432.50 Gg de CO2e debido a una tasa anual de deforestación del 0.77%, y la degradación fue de 27.16 Gg de CO2e a una tasa anual de1 7.64%. Para el periodo 2005–2015, la emisión fue de 145.21 Gg de CO2e debido a una tasa anual de deforestación del 0.44%, y la degradación fue de 24.80 Gg de CO2e a una tasa anual del 4.94%. La mayor pérdida de manglar se debió a la transformación a suelos con categorías de agrícola-pecuario y desarrollo antrópico. La degradación sucedió por fenómenos naturales y actividades antropogénicas.
Identification of a Mr 58 000 glycoprotein subunit of the opiate receptor
Authors: Klee Werner A. , Simonds William F. , Sweat Floyd W. , Burke Terrence R. , Jacobson Arthur E. , Rice Kenner C.
Published: July 2002

A M
r 58 000 subunit of the opiate receptor has been identified using tritiated fentanyl isothiocyanate, a potent opiate alkylating reagent with specificity for the δ‐opiate receptor subclass. The subunit is alkylated in the presence of dextrorphan but not levorphanol. The specifically labelled protein was retained on columns of immobilized wheat germ agglutinin and is therefore presumably a glycoprotein. Partial purification of the M
r 58 000 opiate receptor subunit from neuroblastoma × glioma NG108‐15 hybrid cell membranes is described.
Capacitance—voltage relationship in phospholipid bilayers containing gangliosides
Authors: Usai Cesare , Marchetti Carla , Gambale Franco , Robello Mauro , Gorio Alfredo
Published: July 2002

Changes in the position of the minimum of the parabolic capacitance—voltage curve allow the measurement of the amount of ganglioside present in artificial bilayers made with phosphatidylcholine—ganglioside mixtures and asymmetrically shielded with Ca2+. The screening effect of the ionic solution must be considered. With ganglioside/phospholipid molar ratios of up to 15%, all glycolipids can be found at the membrane surfaces.
Choline transport by synaptosomal membrane vesicles isolated from insect nervous tissue
Authors: Breer Heinz
Published: July 2002

Membrane vesicles derived from insect nervous tissue are capable of accumulating choline via a high affinity, carrier‐mediated process with ion gradients as the sole driving force. The transport is strictly dependent on the presence of Na+ and Cl− in the medium and is stimulated by a membrane potential.
A new role for thioredoxin in assimilatory sulphate reduction
Authors: Schwenn J.D. , Schriek U.
Published: July 2002

The activity of isolated APS‐kinase (EC 2.7.1.25) from the green alga Chlamydomonas reinhardii CW15 was stimulated by catalytic amounts of spinach thioredoxin f. The stimulation amounted to a factor of 3 in the presence of excess reducing thiols. A regulatory function of thioredoxin f was deduced from two observations: (a) the enzyme supported a low basal rate of PAPS formation in the absence of its effector, and (b) the saturation of the enzyme activity by thioredoxin f was sigmoidal. No evidence has been obtained of thioredoxin f serving as in the reduction of PAPS to sulphite in this alga. The slight increase in sulphite formation as observed with enriched spinach thioredoxin m is assumed to be due to a residual APS‐kinase contaminating the partially purified sulpho‐nucleotide unspecific sulphotransferase.
Evidence for a hetero‐oligomeric structure of the chloroplast cytochrome b‐559
Authors: Widger W.R. , Cramer W.A. , Hermodson M. , Herrmann R.G.
Published: July 2002

A second nonhomologous polypeptide in the thylakoid membrane cytochrome b‐559 has been suggested by the finding of a smaller reading frame just slightly downstream from that corresponding to the 9 kDa cytochrome polypeptide that is dominant on a Coomassie‐stained gel. This reading frame encoded a 39‐residue polypeptide that was similar in having a central hydrophobic domain of 25–26 residues and a single His residue at the same position in the hydrophobic domain. The smallest polypeptide seen on SDS gels of the cytochrome was isolated by high‐performance liquid chromatography (HPLC). The NH2‐terminal sequence matched that of the downstream gene. The stoichiometry of the 2 gene products separated by HPLC was approx. 1:1, based on the molecular masses of 9.16 and 4.27 kDa calculated from the nucleotide sequence. It is concluded that the cytochrome contains both the 9.16 kDa (α) and 4.27 kDa (β) polypeptides. These data, the single His residue on each polypeptide, and the previous finding of a bis‐histidine coordination, imply that the unit heme binding structure of the cytochrome is a heme cross‐linked dimer. If the cytochrome contains a single heme, the dimer structure would be (αβ). If there are 2 hemes/cytochrome, the more likely structure would be (αβ)2, a tetramer consisting of 2 heme cross‐linked hetero‐dimers.
Construction of a representative cDNA library from mRNA isolated from mouse oocytes
Authors: McConnell Josie , Watson Christine J.
Published: July 2002

A representative cDNA library has been constructed from the small quantities of poly(A)+ RNA present in unfertilised mouse oocytes. The construction of this library has been achieved by use of cow pea mosaic virus RNA as a carrier during isolation of polyadenylated message and during subsequent cloning procedures. This approach may be applicable to any system in which amounts of mRNA are limiting.
Heparin and the solubilization of asymmetric acetylcholinesterase
Authors: Barat Ana , Escudero Elena , Ramírez Galo
Published: July 2002

Heparin solubilizes asymmetric acetylcholinesterase, from chick skeletal muscle and retina, as a 24 S complex which is quantitatively converted to conventional asymmetric molecular forms of the enzyme (A12 and A8, either class I or class II) upon exposure to high salt. The simultaneous presence of salt and heparin in the homogenization medium selectively prevents, however, the release of class II A‐forms in both muscle and retina. Heparin may generally act by displacing native proteoglycans involved in the attachment of the enzyme tail to the extracellular matrix, or its neural equivalent, being in turn removed by salt to yield typical asymmetric enzyme forms. Heparin would also appear to displace some other molecules specifically involved in the EDTA‐sensitive attachment of class II tailed forms, this effect being antagonized by salt.
The amino acid sequence of the blue copper protein of Alcaligenes faecalis
Authors: Hormel Scott , Adman Elinor , Walsh Kenneth A. , Beppu Teruhiko , Titani Koiti
Published: July 2002

The complete amino acid sequence of a blue copper protein from Alcaligenes faecalis S‐6 has been determined. This protein is clearly homologous to pseudoazurins in Achromobacter cycloclastes and Pseudomonas AM1, more distantly related to plant plastocyanins, and markedly different from the azurin of Pseudomonas
aeruginosa. Yet all of these proteins bind copper, and analogous ligands appear to be involved.
The nucleotide sequences of the heterologous region between the genomes of Bacillus phages M2 and Nf that indicate the two phages are originally identical
Authors: Mizukami Yukiko , Sekiya Takao , Hirokawa Hideo
Published: July 2002

It has been suggested that the heterologous population of Bacillus phage M2 is derived from an original clone, which is identical with phage Nf, by the deletion on a particular region of the genome. We have determined the nucleotide sequence of this region of M2 subclones and Nf genomes. The results clearly indicate that the homologous recombination through the short direct repeated sequence is the main cause of the varied deletions found in the genomes of M2 subclones.
Detection of the major pertussis toxin substrate of human leukocytes with antisera raised against synthetic peptides
Authors: Falloon Judith , Malech Harry , Milligan Graeme , Unson Cecilia , Kahn Richard , Goldsmith Paul , Spiegel Allen
Published: July 2002

Antisera raised against the carboxy‐terminal decapeptide (KENLKDCGLF) of transducin‐α detected the 40 kDa, major pertussis toxin substrate of human neutrophils. The antisera also detected this protein in undifferentiated HL‐60 and U937 cells, and revealed an approx. 2‐fold increase in protein/mg membrane protein with differentiation into mature phagocytic cells. The results provide direct immunochemical evidence for the presence of a novel, pertussis toxin‐sensitive guanine nucleotide‐binding protein in human leukocytes.
Cell attachment and fibrinogen binding properties of platelet and endothelial cell thrombospondin are not affected by structural differences in the 70 and 18 kDa protease‐resistant domains
Authors: Clezardin Philippe , Bourdillon Marie-Claude , Hunter Nikolas R. , McGregor John L.
Published: July 2002

Structural differences between platelet and endothelial cell thrombospondin (TBSP) were found in two protease‐resistant domains (70 and 18 kDa). The 70 kDa fragment is involved in the binding of TBSP to fibrinogen and the 18 kDa fragment in the attachment to various cultured cells. Despite these structural differences, platelet and endothelial cell TBSP bound with the same affinity to fibrinogen and mediated the attachment of smooth muscle cells but not of endothelial cells.
Six myosin heavy chain isoforms are expressed during chick breast muscle development
Authors: Hofmann Sabine , Düsterhöft Sabine , Pette Dirk
Published: July 2002

Two major embryonic myosin heavy chains are expressed in embryonic chick breast muscle until the first week after hatching. Of these, one is already detected in the 8‐day‐old embryo. The other appears on day 12. Two putative slow embryonic isoforms represent minor components transiently expressed between days 8 and 12. A neonatal heavy chain is expressed at low concentrations on day 8 and increases with development. It is the only isoform two weeks after hatching, and is ultimately replaced by the fast myosin heavy chain in the adult muscle.
Muscarinic receptor‐mediated intracellular Ca2+ mobilization in embryonic chick heart cells
Authors: Schmidt Heinrich , Oettling Günter , Drews Ulrich
Published: July 2002

Activation of muscarinic receptors of heart cells elevates the intracellular Ca2+ concentration. The increase is considered to be due to influx of extracellular Ca2+. We show that intracellular Ca2+ mobilization is involved. Cell suspensions prepared from hearts of 6‐day‐old chick embryos were loaded with the fluorescent Ca2+ chelator chlortetracycline. Muscarinic stimulation induces a dose‐dependent fluorescence decrease (ED50=2.6 × 10−6 M) indicating intracellular Ca2+ mobilization.
Megalomycin C, a macrolide antibiotic that blocks protein glycosylation and shows antiviral activity
Authors: Alarcón Balbino , González M.Eugenia , Carrasco Luis
Published: July 2002

Megalomycin C, a natural macrolide antibiotic showed a potent antiherpetic activity. At concentrations that efficiently prevented HSV‐1 multiplication, the compound had no cytotoxic or antiproliferative effects. Viral DNA and protein synthesis took place at normal levels in the presence of the antibiotic, suggesting that neither the translation of viral mRNA, nor the synthesis of viral nucleic acids was affected. The incorporation of mannose and galactosamine into viral proteins was blocked and precursor, but not mature, HSV‐1 glycoproteins were detected in the presence of megalomycin C. Noninfectious HSV‐1 viral particles were formed when the compound was present, but their glycoproteins were not properly glycosylated.
Isolation of two cDNA sequences which encode cytotoxic cell proteases
Authors: Bleackley R.Chris , Duggan Brenda , Ehrman Nancy , Lobe Corrinne G.
Published: July 2002

Two cDNAs which cross‐hybridized with cytotoxic cell protease genes were identified in a library generated from a cytotoxic T cell line. Sequence analysis revealed that the two new members of the family contained the three catalytic triad residues which characterize the active sites of serine proteases. A comparison of the protein sequences revealed not only a high degree of homology but also the conservation of some unusual structural features. These include the lack of a disulphide bond which spans the active site serine, the presence of a signal sequence and the inference of a dipeptide activation sequence.
Primary charge separation in photosystem II involves two electrogenic steps
Authors: Trissl H.-W. , Leibl W.
Published: July 2002

Similarities in the piginent and subunit composition and sequence homologies suggest a common evolutionary origin for the reaction centers (RCs) of photosynthetic purple bacteria and photosystem II (PS II) of green plants [1]. Besides these similarities, significant functional differences exist that make comparative studies between both types of RCs interesting. We report here (i) on the electric detection of two kinetically distinct phases of the primary charge separation in PS II with 100 and 500 ps reflecting trapping and charge stabilization, and (ii) the determination of the dielectrically weighted transmembrane distances between the primary donor (P), the pheophytin intermediary acceptor (I), and the first quinoic acceptor (QA). These data are compared with those for purple bacteria. In PS II the reduction of QA is 2–3‐times slower, although the dielectric distance between I and QA appears to be significantly shorter than in purple bacteria.
Na+, K+‐specific inhibition of protein and peptide hydrolyses by proteasomes from human hepatoma tissues
Authors: Seol Jae Hong , Park Sang Chul , Ha Doo Bong , Chung Chin Ha , Tanaka Keiji , Ichihara Akira
Published: July 2002

Proteasomes were purified from human hepatoma tissues, and their sensitivities to Na+ and K+ were examined. At concentrations of 10 mM or more, these cations were found to inhibit completely polylysine‐activated casein degradation by the purified proteasomes. They also strongly inhibited the hydrolyses of peptides, although to a lesser extent. On the other hand, they reversed the inhibitory and stimulatory effects of polylysine on the hydrolyses of Suc‐Leu‐Tyr‐AMC and Cbz‐Ala‐Arg‐Arg‐MNA, respectively. These results suggest that Na+ and/or K+ may be involved in the regulation of intracellular protein breakdown by controlling the multicatalytic activity of proteasomes.
Rapid actions of 1α,25‐dihydroxyvitamin D3 on Ca2+ and phospholipids in isolated rat liver nuclei
Authors: Baran Daniel T. , Sorensen Ann M. , Honeymano Thomas W. , Ray Rahul , Holick Michael F.
Published: July 2002

The effects of 1α,25‐dihydroxyvitamin D3 (1α,25‐(OH)2D3) on Ca2+ levels and phospholipid metabolism were studied in isolated nuclei prepared from rat liver. Nuclear Ca2+ concentration was estimated with the fluorescent indicator Fura 2. In agreement with previous reports, ATP (1 mM) produced a rapid increase in nuclear Ca2+ from 188 ±25 to 593 ±121 nM. Exposure to 1α,25‐(OH)2D3 (20 nM) also produced a rapid increase in nuclear Ca2+ to 402±71 nM. The 1β epimer of lα,25‐(OH)2D3 had no effect. Nuclear phosphatidylinositol was labeled by incubation with [γ‐32p]ATP for 3 h. 1α,25‐(OH)2D3 produced a two‐fold increase in [32P]lysophosphatidylinositol (LPI) within 5 min from 44 ± 11 to 87 ± 19 cpm/2.5 × 107 nuclei. 1β,25‐(OH)2D3 had no effect on [su32P]LPI production. Exposure of nuclei to exogenous LPI (15μM) produced an instantaneous increase in nuclear Ca2+ to 372±81 nM, comparable to ATP and lα,25‐(OH)2D3. The rapid effects of 1α,25‐(OH)2D3 on phospholipid metabolism and Ca2+ in isolated nuclei suggest that the steroid may exert effects distinct from the well‐characterized receptor‐mediated changes in gene expression.
Biosynthesis of bisbenzylisoquinoline alkaloids in cultured roots of Stephania cepharantha
Authors: Sugimoto Yukihiro , Sugimura Yukio , Yamada Yasuyuki
Published: July 2002

Cultured roots of Stephania cepharantha, which are rich sources of bisbenzylisoquinoline alkaloids, were fed 14C‐labelled tyrosine, tyramine or dopamine. While tyrosine was well incorporated into the bisbenzylisoquinolines, tyramine and dopamine were poorly incorporated. Incorporated tyrosine was shown to be decarboxylated and stored as tyramine in the roots, then gradually converted to the bisbenzylisoquinolines. Tracer experiments using [3‐13C]tyrosine demonstrated that tyrosine was specifically incorporated into the corresponding sites of aromoline, which verified that aromoline was composed of four molecules of tyrosine. The ratio of 13C‐enrichments of C‐4 and C‐α in (R) and (S) halves of aromoline was the same within experimental limits. This indicated that the two coclaurine units must have one and the same biogenetic origin.
G‐proteins in etiolated Avena seedlings Possible phytochrome regulation
Authors: Romero Luis C. , Sommer Debbie , Gotor Cecilia , Song Pill-Soon
Published: July 2002

The molecular mechanism of light signal transduction in plants mediated by the photosensor phytochrome is not well understood. The possibility that phytochrome initiates the signal transduction chain by modulating a G‐protein‐like receptor is examined in the present work. Etiolated Avena seedlings contain G‐proteins as examined in terms of the binding of GTP as well as by cross‐reaction with mammalian G‐protein antibodies. The binding of GTP was regulated in vivo by red/far‐red light. The possible involvement of G‐proteins in the phytochrome‐mediated signal transduction in etiolated Avena seedlings has been implicated from the study of the light regulated expression of the Cab and phy genes.
Time‐resolved tryptophan fluorescence in photosynthetic reaction centers from Rhodobacter sphaeroides
Authors: Godik Valentina I. , Blankenship Robert E. , Causgrove Timothy P. , Woodbury Niel
Published: July 2002

Tryptophan fluorescence of reaction centers isolated from Rhodobacter sphaeroides, both stationary and time‐resolved, was studied. Fluorescence kinetics were found to fit best a sum of four discrete exponential components. Half of the initial amplitude was due to a component with a lifetime of ≅ 60 ps, belonging to Trp residues, capable of efficient transfer of excitation energy to bacteriochlorophyll molecules of the reaction center. The three other components seem to be emitted by Trp ground‐state conformers, unable to participate in such a transfer. Under the influence of intense actinic light, photooxidizing the reaction centers, the yield of stationary fluorescence diminished by ⋍1.5 times, while the number of the kinetic components and their life times remained practically unchanged. Possible implications of the observed effects for the primary photosynthesis events are considered.
Evidence for a distinct H7‐resistant form of protein kinase C in rat anterior pituitary gland
Authors: Ison Angela J. , MacEwan David J. , Johnson Melanie S. , Clegg Roger A. , Connor Kevin , Mitchell Rory
Published: July 2002

Inhibition of phorbol 12,13‐dibutyrate‐induced protein kinase C (PKC) activity from rat midbrain, anterior pituitary and a number of other tissues, as well as COS 7 cells, was studied in vitro. In anterior pituitary, Ca2+‐independent activity was notably resistant to H7 but sensitive to staurosporine and Ro 31‐8220. All Ca2+‐dependent activity was sensitive to these three inhibitors. Mezerein and 1,2‐dioctanoyl‐sn‐glycerol also activated this H7‐insensitive PKC from anterior pituitary. The distribution of this activity, prominently expressed in pituitary and perhaps also lung, and its characteristic resistance to H7 but not other inhibitors, does not obviously correlate with that of any of the well‐characterised PKCs, and may reflect either a novel or a modified isoform.
Widespread distribution of free d‐aspartate in rat periphery
Authors: Hashimoto Atsushi , Nishikawa Toru , Oka Takae , Hayashi Tokishi , Takahashi Kiyohisa
Published: July 2002

We have identified and quantified free d‐aspartate in adult rat peripheral organs using gas chromatographic‐mass spectrometric and high‐performance liquid Chromatographic techniques. The level of free d‐aspartate was highest in the adrenal, testis, spleen and pituitary, followed by the thymus, lung, ovary, placenta, pancreas and heart, and below the detection limit in the kidney, liver, brain, muscle and serum. These data provide the first evidence that a high level of free d‐aspartate widely occurs in the adult rat periphery and suggest that the d‐amino acid may be an endogenous substrate for d‐aspartate oxidase.
Increased expression of nucleoside diphosphate kinases/nm23 in human diploid fibroblasts transformed by SV40 large T antigen or 60Co irradiation
Authors: Ohneda Kinuko , Fukuda Mitsugu , Shimada Nobuko , Ishikawa Naoshi , Ichou Tateo , Kaji Kazuhiko , Toyota Takayoshi , Kimura Narimichi
Published: July 2002

When the expression levels of nucleoside diphosphate (NDP) kinase/nm23 were examined in four human normal diploid fibroblast cell lines in comparison with their corresponding immortalized cells transformed by SV40 large T antigen or 60Co irradiation, mRNA levels of the two isoforms (NDP kinase A/nm23‐H1, NDP kinase B/nm23‐H2) were increased in the immortalized cell lines. The increase was found to be associated with increased translation products. Furthermore, the cell extracts prepared from these immortalized cell lines demonstrated slightly higher enzyme activity than those from their normal counterparts. Neither the growth state nor the in vitro aging largely affected their expression in a normal cell line (TIG‐3) examined. The results suggest possible involvement of NDP kinases/nm23 in acquiring an infinite growth property of these cells.
PrP‐dependent cell adhesion in N2a neuroblastoma cells
Authors: Mangé Alain , Milhavet Ollivier , Umlauf David , Harris David , Lehmann Sylvain
Published: July 2002

The cellular isoform of prion protein (PrPC) is a ubiquitous glycoprotein expressed by most tissues and with a biological function yet to be determined. Here, we have used a neuroblastoma cell model to investigate the involvement of PrP in cell adhesion. Incubation of single cell suspension induced cell–cell adhesion and formation of cell aggregates. Interestingly, cells overexpressing PrP exhibit increased cation‐independent aggregation. Aggregation was reduced after phosphatidylinositol‐specific phospholipase C release of the protein and by pre‐incubation of cells with an antibody raised against the N‐terminal part of PrPC. Our paradigm allows the study of the function of PrP as an intercellular adhesion molecule and a cell surface ligand or receptor.
Sodium butyrate inhibits the expression of the human lecithin:cholesterol acyltransferase gene in HepG2 cells by a post‐transcriptional mechanism
Authors: Skretting Grethe , Gjernes Elisabet , Prydz Hans
Published: July 2002

© 1997 Federation of European Biochemical Societies.
Selective peroxisome degradation in Yarrowia lipolytica after a shift of cells from acetate/oleate/ethylamine into glucose/ammonium sulfate‐containing media
Authors: Gunkel Katja , van der Klei Ida J. , Barth Gerold , Veenhuis Marten
Published: July 2002

We have shown that peroxisomes of the yeast Yarrowia lipolytica are subject to specific degradation after exposure of acetate/oleate‐grown cells to glucose excess conditions. Electron microscopic analysis has revealed that the peroxisomes were degraded by uptake in the vacuole. Our results suggest that peroxisomes are taken up by macroautophagic processes, because sequestration of individual peroxisomes, which occurs typically at the beginning of microautophagy, was never observed. The observation that a peroxisomal amine oxidase activity is specifically induced by ethylamine was used for the development of a plate assay screening procedure to isolate peroxisome degradation‐defective mutants.
Dimerization of Arabidopsis 14‐3‐3 proteins: structural requirements within the N‐terminal domain and effect of calcium
Authors: Abarca Dolores , Madueño Francisco , Martı́nez-Zapater José Miguel , Salinas Julio
Published: July 2002

The structural requirements for dimerization of RCI14A and RCI14B, two 14‐3‐3 isoforms from Arabidopsis thaliana, have been analyzed by testing truncated forms of RCI14A for dimerization with full‐length RCI14A and RCI14B. The results show that only the fourth helix of the truncated partner is essential for dimerization, which represents a difference from what is known for animal isoforms. On the other hand, the effect of calcium has been tested in RCI14A homodimerization. Millimolar concentrations of calcium exert a negative, dose‐dependent effect that involves the C‐terminal domain of RCI14A and might modulate interactions with other cellular components or among Arabidopsis 14‐3‐3 isoforms.