bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-Cost 3D Depth Sensors for Mobile Applications and Control Systems – Accuracy Assessments Using Surveying Techniques
Authors: Janos Daniel , Ortyl Łukasz , Kuras Przemysław
Published: February 2025

This article focuses on low-cost LiDAR (light detection and ranging) sensors and 3D depth cameras. Particular attention was paid to their accuracy and compliance with the technical specifications that were provided by their respective manufacturers. The following devices were tested: Stereolabs ZED 2i, Stereolabs ZED, and Intel RealSense D435i depth cameras, and the Intel RealSense L515 LiDAR sensor. An experiment was carried out to measure a geometrically diverse environment (which is typical for in-motion imaging) where both the measurement range and the distortion that is generated by each device’s algorithms on edges, folds, planes, and 3D objects could be evaluated. Depth sensors are often used with excessive confidence as to their geometric reliability. The aim of this work is to assess the actual accuracy of such sensors, which may constitute the ground truth for accuracy losses that could result from the operations of autonomous vehicles. Based on the results, the accuracy information that was provided by the respective manufacturers was difficult to obtain under real conditions. It was found that the low-cost devices could be used in industrial projects, but their operations must take place under certain conditions and settings. It was also necessary to know their capabilities and limitations in order to take full advantage of what they offer.
Robust variability of grid cell properties within individual grid modules enhances encoding of local space
Authors: Redman William T , Acosta-Mendoza Santiago , Wei Xue-Xin , Goard Michael J
Published: February 2025

Although grid cells are one of the most well-studied functional classes of neurons in the mammalian brain, whether there is a single orientation and spacing value per grid module has not been carefully tested. We analyze a recent large-scale recording of medial entorhinal cortex to characterize the presence and degree of heterogeneity of grid properties within individual modules. We find evidence for small, but robust, variability and hypothesize that this property of the grid code could enhance the encoding of local spatial information. Performing analysis on synthetic populations of grid cells, where we have complete control over the amount heterogeneity in grid properties, we demonstrate that grid property variability of a similar magnitude to the analyzed data leads to significantly decreased decoding error. This holds even when restricted to activity from a single module. Our results highlight how the heterogeneity of the neural response properties may benefit coding and opens new directions for theoretical and experimental analysis of grid cells.
Stochastic cell-intrinsic stem cell decisions control colony growth in planarians
Authors: Frankovits Tamar , Cherian Prakash Varkey , Yesharim Yarden , Dobler Simon , Wurtzel Omri
Published: February 2025

Stem cells contribute to organismal homeostasis by balancing division, self-renewal and differentiation. Elucidating the strategies by which stem cells achieve this balance is critical for understanding homeostasis, and for addressing pathogenesis associated with the disruption of this balance (e.g., cancer). Planarians, highly regenerative flatworms, use pluripotent stem cells called neoblasts to maintain and regrow organs. A single neoblast can rescue an entire animal depleted from stem cells and regenerate all cell lineages. How neoblast differentiation and clonal expansion are governed to produce all the required cell types is unclear. Here, we integrated experimental and computational approaches to develop a quantitative model revealing basic principles of clonal growth of individual neoblasts. By experimentally suppressing differentiation to major lineages, we elucidated the interplay between colony growth and lineage decisions. Our findings suggest that neoblasts select their progenitor lineage based on a cell-intrinsic fate distribution. Arresting differentiation into specific lineages disrupts neoblast proliferative capacity without inducing compensatory expression of other lineages. Our analysis of neoblast colonies is consistent with a cell-intrinsic decision model that can operate without memory or communication between neoblasts. This simple cell fate decision process breaks down in homeostasis, likely because of the activity of feedback mechanisms. Our findings uncover essential principles of stem cell regulation in planarians, which are distinct from those observed in many vertebrate models. These mechanisms enable robust production of diverse cell types and facilitate regeneration of missing tissues.
Multi-Omics Single-Cell Analysis Reveals Key Regulators of HIV-1 Persistence and Aberrant Host Immune Responses in Early Infection
Authors: Lee Dayeon , Choi Sin Young , Shin So-I , An Hyunsu , Choi Byeong-Sun , Park Jihwan
Published: February 2025

The clearance of human immunodeficiency virus-1 (HIV-1) remains a significant public health challenge due to impaired cellular immune responses and HIV-1 maintenance during acute infection. However, the genetic and epigenetic changes influencing the immune response on host infected cells remain unclear. Here, this study analyzes HIV-1 infected CD4+ T cells from peripheral blood mononuclear cells from people living with HIV-1 (PLWH) during early infection (<6 months) using single-cell RNA and ATAC sequencing. It is observed that HIV-1 hinders the antiviral response, particularly by interfering with the interferon signalling pathway. Multimodal analysis identifies KLF2 as a key transcription factor in infected CD4+ T cells. Moreover, cells harbouring HIV-1 provirus are predominantly identified as Th17 cells, which exhibit elevated KLF2 activity. This suggests an increased susceptibility to HIV-1 infection and a constrained immune response due to the quiescent characteristics of these cells. The finding provides insights into the immune mechanisms and key regulators of HIV-1 maintenance in CD4+ T cells during the early stages of infection.
Unravelling approaches to study macrophages: from classical to novel biophysical methodologies
Authors: Vishnyakova Polina , Elchaninov Andrey , Fatkhudinov Timur , Kolesov Dmitry
Published: February 2025

Macrophages play crucial roles in immune responses and tissue homeostasis. Despite the fact that macrophages were described more than a century ago, they continue to be the cells of intensive interest. Advanced understanding of phenotypic diversity in macrophages holds great promise for development of cell-based therapeutic strategies. The introduction of innovative approaches in cell biology greatly enhances our ability to investigate the unique characteristics of macrophages. The review considers both classical methods to study macrophages and high-tech approaches, including single-cell sequencing, single-cell mass spectrometry, droplet microfluidics, scanning probe microscopy and atomic force spectroscopy. This review will be valuable both to specialists beginning their study of macrophages and to experienced scientists seeking to deepen their understanding of methods at the intersection of biological and physical sciences.
Leituras amorosas com as escolhas na natureza: singularidades do processo de alfabetização
Authors: Dias Cristiane Barroso , Costa Alessandra Canela do Rosario
Published: February 2025

O texto apresenta um diálogo entre duas pesquisas em desenvolvimento pela Universidade do Estado do Rio de Janeiro, Faculdade de Formação de Professores/as, Programa de Pós-Graduação em Educação - Processos Formativos e Desigualdades Sociais, com a metodologia de pesquisa narrativa (auto)biográfica (Bragança, Prado, Araújo, 2021), onde uma professorapesquisadora[1], outrora estudante, viveu o processo de reconhecer quem se é, atravessada às falas libertadoras de sua então professora da classe de alfabetização, numa escola envolta à natureza. A mesma busca reconhecer se as recordações-referências de docentes em épocas de estudantes reverberam em suas práticas atuais. Esta pesquisa vai de encontro às narrativas da segunda professorapequisadora atuante na Orientação Educacional, porque esta última traz as narrativas dos/as meninos/as da rede municipal  de Maricá, no distrito de Itaipuaçu, no Campus de Educação Pública Transformadora Leonel de Moura Brizola, estado do Rio de Janeiro, no ano de 2023, local este de belezas naturais. E tem como questionamento: Por que crianças do 5º ano escolar estão em processo inicial de apropriação do código alfabético? Será que esses estudantes leem o mundo, como fez a menina Canela? As pesquisas dialogam, pois os/as menino/as, estudantes do processo de alfabetização, tem também no território ao redor de sua escola um espaço de natureza e o diálogo com uma professora, como outrora a menina Canela, e buscam a partir da relação dialógica, inspiradas pelos estudos freirianos, a educação como libertação coletiva.
El camino hacia un diagnóstico temprano de la amiloidosis cardíaca por transtiretina en Argentina
Authors: Decotto Santiago , Pérez de Arenaza Diego
Published: February 2025

La amiloidosis cardíaca por transtiretina es una causa significativa, aunque subdiagnosticada, de insuficiencia cardíaca en adultos mayores. En los últimos años, su incidencia diagnóstica ha mostrado un aumento considerable. Los autores del manuscrito Amiloidosis cardíaca por transtiretina: desarrollo de un modelo de predicción y escala de puntuación para el diagnóstico presentan el score deteCTTAR, un modelo de predicción desarrollado íntegramente a partir de datos locales, lo cual garantiza que las herramientas diagnósticas sean realmente útiles en nuestro entorno. Herramientas como el score deteCTTAR no solo representan una oportunidad de mejorar el diagnóstico de la amiloidosis cardíaca, sino también de optimizar el pronóstico a través de un tratamiento precoz.
Response of Foliar Spray of Nutrients on Yield and Nutrient Uptake by Black Gram (Vigna mungo L.)
Authors: Baggad Jitendra , Mishra Deepak , Regar Champa Lal , Mehta Promod , Gurjar Om Prakash , Yadav Indra Raj
Published: February 2025

A field experiment was conducted at experimental farm, Department of Agronomy, A field experiment was conducted at experimental farm, Department of Agronomy, Faculty of Agriculture and Veterinary Sciences, Mewar University Gangrar, Chittorgarh (Rajasthan) during Rabi season of 2023-24 to Response of foliar spray of nutrients on yield and nutrient uptake by black gram variety “Pratap Urd-1‟ was used in this study. The result revealed that the maximum yield parameter such as number of pods per plant (15.20), number of seed per pod (6.44), grain yield (11.52 q/ha), straw yield (5.62 q/ha) with application of T9-100% RDF + T7 + Foliar application of ZnSO4 @ 0.2%. The maximum nitrogen content in grain and straw (3.58 and 1.64%), phosphorus (0.39 and 0.48%), potassium content (1.73 and 1.62%) and nitrogen uptake in grain and straw (27.37 and 25.62 kg/ha), phosphorus (4.49 and 7.50 kg/ha) and potassium uptake (19.93 and 25.30 kg/ha) were recorded with T9-100% RDF + T7 + Foliar application of ZnSO4 @ 0.2%. It was concluded that the treatment T9-100% RDF + T7 + Foliar application of ZnSO4 @ 0.2% found significantly higher yield and nutrient uptake by black gram.
Bacterial and Heavy Metals Contaminations of Some Vegetables in Mali
Authors: Traoré Sanata , Samaké Salimatou , Diabaté Daouda , Fané Rokiatou , Dao Sognan , Kassogué Adounigna , Traoré Diakaridia , Samaké Fassé , Babana Amadou Hamadoun
Published: February 2025

Fresh vegetables eaten raw can be agents of transmission of microbes and heavy metals. The frequency and variability of microbes and heavy metals on 96 vegetables from some large production sites in Mali were evaluated. These sites were Bamako, Kati, Baguineda, Samanko, Sikasso and Niono. Among all sites, lettuce, tomato and cucumber from Sikasso were the least contaminated, and the concentrations of total microflora, total and faecal coliforms and Staphylococcus aureus on lettuce were respectively 19.88 × 104 CFU/g; 0.85 × 104 CFU/g; 0.73 × 104 CFU/g and 0.48 × 104 CFU/g. The concentrations of microorganisms on tomato following the order of the previous line were respectively 12.48 × 104 CFU/g; 0.24 × 104 CFU/g; 0.00 CFU/g and 0.97 × 104 CFU/g. The contamination of cucumber, still following the same order were 51.15 × 104 CFU/g; 13.33 × 104 CFU/g; 4.24 × 104 CFU/g and 11.03 × 104 CFU/g.. Vegetables from Kati were the most contaminated and the concentrations of lettuce were 145.58.104 CFU/g for the total microflora; 56.36 ×104 CFU/g for total coliforms; 23.03 × 104 CFU/g for faecal coliforms, 27.88 × 104 CFU/g for Staphylococcus aureus, 0.87 × 104 for Clostridium perfringens and 31.15 × 104 for Listeria monocytogenes. The concentrations of tomato were respectively 85.33 × 104 CFU/g; 12.48 × 104 CFU/g; 9.58 × 104 CFU/g; 17.94 ×104 CFU/g; 0.24 × 104 and 18.67 × 104 CFU/g. And the concentrations of cucumber were 67.64 × 104 CFU/g; 13.70 × 104 CFU/g; 9.82 × 104 CFU/g; 0.61 × 104 CFU/g; 1.28 × 104 and 14.42 × 104 CFU/g, respectively. Among vegetables, lettuce was the most contaminated at all sites except Sikasso and Baguineda where cucumber was the most contaminated.
Developing a Spatially Explicit Forest Database for Planning and Carbon Stock Estimation: A GIS-based Approach in Rajgarh Forest Division of Sirmaur District, Himachal Pradesh, India
Authors: Attri Varun , Sharma D P
Published: February 2025

The conventional method of forest plan preparation cannot provide real-time forest inventory data, making planning inefficient. It struggles with data synthesis, retrieval, and reliability due to scattered sources. GIS addresses these challenges by efficiently storing, retrieving, and analyzing spatial and non-spatial data, enhancing precision, objectivity, and cost-effectiveness in forest management. This study aimed to develop a comprehensive forest resource database and spatial analysis of growing stock and carbon stock for Rajgarh Forest Division in Sirmaur district, Himachal Pradesh located between 30° 38’40” to 31° 01’14” N latitude and 77°01’5” to 77°26’13”E longitude, at an elevation ranging from 500 m to 3500 ma.s.l. Maps and toposheets from the Rajgarh Forest Division were scanned, georeferenced and digitized in ArcMap. Key features such as forest boundaries, roads, rivers, compartments, and land uses were digitized, and a GIS database was created. Forest attributes, including area, vegetation types, working circles, and growing stock, biomass and carbon stock were entered into the database. Thematic maps were prepared, and growing stock and carbon stock distribution were analyzed across different forest units using GIS-based extrapolation of enumerated sampling data. The Rajgarh Forest Division consists of six working circles, four ranges, 879 compartments, and 41 beats. A small to very small variation in the area of management units, forest vegetation, and land uses was observed compared to the reported Working Plan. The total growing stock and carbon stock were estimated at 7.05×10⁶ m³ and 3.29×10⁶ t, respectively. The contribution of different forest ranges to total growing stock and carbon stock was: Habban (71.98% and 67.85%), Rajgarh (19.72% and 22.59%), Narag (4.03% and 5.06%), and Sarahan (4.27% and 4.50%). Among the working circles, Chil Shelterwood, Deodar-Kail, Rehabilitation, Plantation, Protection, and Selection contributed 8.98% & 9.15%, 31.37% & 28.44%, 6.45% & 7.73%, 2.47% & 2.57%, 15.13% & 21.66%, and 35.59% & 30.45% to the total growing stock and carbon stock, respectively. Among the forest vegetation types in Rajgarh Forest Division, the highest growing stock was recorded in Oaks (1.79×10⁶ m³), followed by Deodar (1.79×10⁶ m³), Spruce (1.43×10⁶ m³), and Chil (8.53×10⁵ m³), with the lowest in Bamboo (9.26×10² m³). Carbon stock was highest in Oaks (1.41×10⁶ t), followed by Deodar (6.32×10⁵ t) and Spruce (4.08×10⁵ t), while Bamboo had the lowest (4.14×10² t). The study highlights the utility of GIS in forest management, emphasizing its role in database development and forest inventory analysis. The results provide a critical foundation for sustainable forest planning, resource allocation, and conservation strategies in the Rajgarh Forest Division.
Spatio-temporal distribution of mortality among motorcyclists: an ecological study / Distribuição espaço-temporal da mortalidade entre motociclistas: um estudo ecológico
Authors: Morais Andreza Moita , Araujo Thalis Kennedy Azevedo de , Filho Adriano Flavio Santos Gonçalves
Published: February 2025

Objetivo: analisar a distribuição espacial e temporal da mortalidade por acidentes motociclísticos no Piauí de 2011 a 2021. Método: trata-se de um estudo ecológico, em que foram analisados os óbitos por acidentes motociclísticos ocorridos no estado do Piauí. A análise de regressão temporal foi realizada por meio do software Joinpoint e a análise espacial utilizou-se o programa QGIS. Resultados: no período estudado foram registrados 7.250 óbitos por acidentes motociclísticos no Piauí. A taxa de mortalidade média foi de 23,81 óbitos por 100 mil habitantes. A análise espacial mostrou elevadas taxas de mortalidade na macrorregião de saúde do Meio Norte. Conclusão: embora haja uma tendência de queda nas taxas de mortalidade no estado piauiense, ainda é um agravo preocupante, pois atinge a população jovem e economicamente ativa. Este estudo fornece evidências que contribuem para implementação e reformulação de políticas públicas de saúde de monitorização, fiscalização e educação no trânsito.
Knowledge, perceptions and experiences of women users of the family health strategy regarding the cytopathological examination / Conhecimento, percepções e vivências de mulheres usuárias da Estratégia Saúde da Família frente ao exame citopatológico
Authors: Amthauer Camila , Ulrich Jaíne
Published: February 2025

Objetivo: compreender a percepção de mulheres usuárias da Estratégia Saúde da Família frente ao exame citopatológico. Método: pesquisa qualitativa, descritiva-exploratória, desenvolvida com treze mulheres em um município do extremo oeste de Santa Catarina. A coleta de dados aconteceu por meio de entrevista semiestruturada, de caráter individual. Para análise dos dados, utilizou-se a Análise de Conteúdo do Tipo Temática. Resultados: da análise, emergiram três categorias temáticas: Conhecimento de mulheres sobre o exame citopatológico; Percepções e vivências acerca do exame citopatológico; e, Assistência dos profissionais de saúde frente ao exame citopatológico. Considerações finais: apreende-se que a adesão ao exame citopatológico envolve diversos fatores comportamentais, sociais, culturais e assistenciais, que podem interferir diretamente nas práticas de rastreamento do câncer de colo do útero. Assim, o acolhimento, a empatia, o vínculo e a comunicação efetiva entre profissional e usuária são essenciais para a ampliação da cobertura do exame.
Importância Dos Vínculos Familiares Para O Tratamento Terapêutico No Caps: Um Olhar Dos Profissionais Do Caps Ii De Pedreiras Maranhão
Authors: Neto Francisco De Souza Cavalcante , Sousa Ronny Batista De , Santo Ilana Maria Brasil Do Espírito , Da Silva Redycson Rodrigues Alves , Teixeira Talita Maciel , Filho Antonio Cézar Sobreira Marques
Published: February 2025

O presente estudo visa analisar os fatores que influenciam a relação entre familiares e usuários do CAPS,
compreendendo como a saúde mental impacta a dinâmica familiar e a participação dos envolvidos na
sociedade. O método utilizado foi o descritivo, com abordagem qualitativa através de pesquisa campo e
bibliográfica. Para a coleta de dados utilizou-se um questionário de pesquisa construído pelo pesquisador,
tendo como sujeitos pesquisados alguns profissionais do CAPS II da cidade de Pedreiras- Ma. Após a análise
dos dados coletados pode-se compreender que participação dos familiares nas atividades e ações desenvolvidas
acontece direta e indiretamente, por meio de atividades complexas como festividades, grupos de família,
consultas etc. Outra questão é sobre a importância dos vínculos familiares no contexto do tratamento
terapêutico nos CAPS, e viu-se que os vínculos familiares devem sempre fazer parte do processo terapêutico, na
verdade estes são de extrema necessidade, justamente por saber que os familiares são coparticipação na
evolução da melhoria do quadro clínico dos pacientes. Percebeu-se que acontece por parte dos Centros de
Atenção Psicossocial uma grande tentativa de resgate também desses familiares. Assim, concluiu-se que o
CAPS que fez parte desse estudo construiu efetivamente para as famílias um ambiente de acolhimento e escuta,
não somente de tratamento, na busca de estar sempre interagindo com dinâmica familiar no processo de
reabilitação dos indivíduos com distúrbios mentais propiciando uma maior atenção e integração, seja
individualizada ao usuário, seja no apoio e auxilio às famílias, baseada na formação de vínculos familiares,
dada através da tríade (profissionais, usuários e familiares). Ainda foi possível através do estudo ver que são muitos os desafios enfrentados por usuários e família, que vai mais além do que se pode entender
Mental Suffering In Women With Breast Cancer During The Covid-19 Pandemic: Integrative Review
Authors: Santo Ilana Maria Brasil Do Espírito , Sousa Ronny Batista De , Beserra Patrick Sabóia , Da Silva Hildamar Nepomuceno , Mendes Tiago De Campos , Da Silva Nedson Lechner
Published: February 2025

Breast cancer poses a significant challenge to public health, being the most common form of cancer among
women globally. It is also one of the leading causes of disease-related mortality. Objective: To analyze the
mental distress in women with breast cancer during the COVID-19 pandemic. An integrative literature review
was conducted using the following databases: Medical Literature Analysis and Retrieval System Online
(MEDLINE), via PubMed; Web Of Science (WOS); Literatura Latino-Americana e do Caribe em Ciências da
Saúde (LILACS), via Biblioteca Virtual em Saúde (BVS); and Index To Nursing And Allied Health Literature
(CINAHL), using the descriptors: women with breast cancer AND mental distress AND COVID-19. In the initial
selection, according to exclusion criteria, 88 studies were eliminated. After applying both exclusion and
inclusion criteria, 12 studies were eligible for analysis. As a result, there is a correlation between the diagnosis
of breast cancer, the pandemic, and the significant increase in symptoms of anxiety, depression, and emotional
stress. The discussed studies emphasize the importance of an approach in caring for these women that takes into
account not only the medical aspects of treatment but also the psychosocial and emotional aspects. It is
concluded that there is a need for future studies that include longitudinal assessment of the psychological
impact on women with breast cancer during the pandemic, investigation of the effectiveness of psychosocial interventions, and exploration of protective factors associated with psychological well-being
Group II phospholipase A2 activates mitogen‐activated protein kinase in cultured rat mesangial cells
Authors: Sugiura Toshihiro , Wada Akira , Itoh Takahito , Tojo Hiromasa , Okamoto Mitsuhiro , Imai Enyu , Kamada Takenobu , Ueda Naohiko
Published: July 2002

Group II phospholipase A2 (PLA2) is a mediator of inflammation in various disease including glomerulonephritis. We recently found that urinary excretion of PLA2 was increased in patients with mesangial proliferative glomerulonephritis and that interleukin‐1 (IL‐1) enhanced platelet derived growth factor‐stimulated mesangial cell proliferation through the action of group II PLA2 secreted in response to IL‐1 stimuli. Here we report signal transducing mechanism through group II PLA2 in mesangial cells. Group II PLA2 (1–15 U/ml) rapidly activated mitogen‐activated protein (MAP) kinase. IL‐1β activated MAP kinase in two phases and the slow activation in the late phase, proceeding in parallel with increased group II PLA2 secretion elicited by IL‐1 treatment, was inhibited by the specific antibody raised against group II PLA2. This suggests that the late phase activation of IL‐1‐induced MAP kinase was mediated, at least in part, by secreted group II PLA2.
Molecular flexibility in wheat gluten proteins submitted to heating
Authors: Hargreaves Jeremy , Popineau Yves , Le Meste Martine , Hemminga Marcus A.
Published: July 2002

Prolamin proteins are responsible for the network that gives wheat dough its viscoelastic properties. Non‐prolamin depleted gluten was prepared under conditions that preserve its functionality. Electron Spin Resonance (ESR) was used to provide information about the dynamics of the protein at temperatures between 5 and 90°C by specific spin labelling of its cysteine residues. The spectra were of a composite type, resulting from at least two populations of spin labels largely differing in molecular mobility. The correlation time of the less mobile nitroxide radicals was determined by saturation transfer ESR. Upon heating there was a transfer from the slow to the fast moving population of radicals, and an increase of mobility of this last catagory that followed the Arrhenius law. The effect of temperature on molecular flexibility was reversible. This was not the case for purified, polymerised glutenin subunits extracted from gluten. Urea created similar modifications on gluten as heat.
Concomitant expression of hepatocyte growth factor (HGF), HGF activator and c‐met genes in human glioma cells in vitro
Authors: Moriyama Takuzou , Kataoka Hiroaki , Tsubouchi Hirohito , Koono Masashi
Published: July 2002

Three new cell lines of human glioblastoma have been established. These cells co‐expressed hepatocyte growth factor (HGF) and its receptor, c‐Met, genes in vitro. Reverse‐transcriptase/polymerase‐chain reaction study revealed that the cells also expressed gene for HGF activator, a recently cloned serine proteinase, suggesting that HGF might have a role in glioma cells in vitro as an autocrine factor. The activator mRNA was also detected in other well‐established glioma cell lines, glioma tissues and normal brain. The concomitant expression of HGF, HGF activator and c‐met was also detected in one glioblastoma case in vivo out of five tested.
Most immunoglobulin heavy chain switch mu rearrangements in B‐cell chronic lymphocytic leukemia are internal deletions
Authors: Nardini Elena , Rizzi Simona , Capello Daniela , Vitolo Umberto , Gaidano Gianluca , Menard Sylvie , Balsari Andrea
Published: July 2002

We investigated 38 cases of B‐cell chronic lymphocytic leukemia (B‐CLL) for the presence of non‐productive rearrangements in the Sμ regions and defined for the first time the molecular nature of these rearrangements. Southern blot analysis revealed Sμ region rearrangements in 13 cases (34%) and polymerase chain reactions (PCRs) indicated that these rearrangements consisted of internal deletions of the Sμ region. Long‐distance PCRs localized the Sμ deletions in the VHDJH rearranged allele in most cases. We investigated if Sμ deletions were related to VH somatic mutations that, together with isotype switch recombination, are indicative of the B‐cell maturation stage. No significant correlation between the presence of Sμ deletions and VH somatic mutations was found, indicating that the two processes are independent in B‐CLL. Moreover no significant correlation between Sμ deletions and prognosis was observed. Having shown that Sμ internal deletions are not chromosome translocations rules out their involvement in the onset of malignancy, while their localization in the VHDJH rearranged alleles suggests a possible role in the stabilization of the isotype of the expressed immunoglobulin.
cDNA cloning and characterization of tobacco ABC transporter:NtPDR1is a novel elicitor‐responsive gene1
Authors: Sasabe Michiko , Toyoda Kazuhiro , Shiraishi Tomonori , Inagaki Yoshishige , Ichinose Yuki
Published: July 2002

We isolated an INF1 elicitin‐inducible cDNA encoding a pleiotropic drug resistance (PDR)‐type ATP‐binding cassette (ABC) transporter homolog (NtPDR1) in suspension‐cultured tobacco Bright Yellow‐2 (BY‐2) cells by application of differential display PCR. TheNtPDR1(Nicotiana tabacumPDR protein 1) gene also encodes a 162 kDa protein that includes two putative hydrophilic domains containing the ABC signature motif and two putative hydrophobic domains. Expression of theNtPDR1gene was rapidly and strongly activated by treatment of BY‐2 cells with INF1 elicitin. Further, treatment of BY‐2 cells with flagellin, a bacterial proteinaceous hypersensitive reaction elicitor, or yeast extract, a general elicitor, also inducedNtPDR1gene expression. These results indicate that NtPDR1 may be involved in the general defense response in tobacco. This is the first report that microbial elicitors induce the expression of a plant ABC transporter gene.
Frequency and significance of preterm delivery in twin pregnancies
Authors: Büscher U. , Horstkamp B. , Wessel J. , Chen F.C.K. , Dudenhausen J.W.
Published: July 2002

Objective: We investigated the frequency of preterm delivery and its influence on the neonatal outcome in twin pregnancies at a perinatal center. Are there differences in the course of twin pregnancies with preterm or term delivery? Method: A retrospective investigation was carried out at the Department of Obstetrics on 502 twin pregnancies and deliveries between 1978 and 1993. Pregnancy history and clinical parameters were compared among preterm (<37+0 weeks) and term deliveries. Result: Median duration of all twin pregnancies was 36+3 weeks of gestation. In the preterm group, preterm labor was more frequent, both, the first and the second neonate had lower birth weight and were more often admitted to the neonatal intensive care unit (NICU) where they stayed longer than full‐term neonates needing intensive care. Perinatal deaths occurred only in the preterm group. Conclusions: The incidence of preterm delivery is significantly elevated in twin pregnancies and consequently the incidence of low‐ and very‐low‐birth‐weight‐infants and perinatal mortality. Preterm delivery is the main reason why twin pregnancies are at a higher risk for an adverse neonatal outcome and thereby cause considerable costs.
Presidential Power and Democratic Development in Post-Communist Politics1
Authors: Ishiyama John T. , Velten Matthew
Published: July 2002

Recently, scholars have debated the effects of presidentialism on the development of new democracies. We seek to add to this debate by: (1) extending the investigation to the post-communist countries of Eastern Europe and the former Soviet Union; (2) employing an interval measure of presidential power as opposed to previously used categorical measures of presidentialism; (3) testing the relationships between institutions and democratic consolidation using multivariate rather than bivariate analytical techniques. In sum, the evidence suggested that the electoral system had a greater effect than either the power of the constitutional president or socio–cultural or economic factors on various measures of democracy and consolidation.
Elections and democracy in Russia
Authors: Pammett Jon H.
Published: July 2002

The word ‘democracy’ has predominantly negative connotations when referring to its practical implementation in Russia. However, Russians are favourable to the idea of democracy in principle, and support the establishment of genuine democracy in the country. Beliefs that elections ensure accountability of elected officials, allow public input on the policy direction of government, and give personal benefits to individuals would help to increase acceptance of the value of Russian democracy. A combination of factors, however, makes it doubtful that the current negative attitudes can be overcome quickly.
Cell Segregation and Lysis Have Profound Effects on the Growth of Escherichia coli in High Cell Density Fed Batch Cultures
Authors: Andersson Lena , Strandberg Lars , Enfors Sven‐Olof
Published: July 2002

Cell segregation into nondividing states and lysis was found to dominate the growth behavior of high cell density fed batch cultures of Escherichia coli. When the specific growth rate declined below a critical value, the biomass production, oxygen consumption, and carbon dioxide formation rates declined sharply. Concomitantly, an extensive loss of colony‐forming ability (cfu) and accumulation of extracellular proteins was observed. A segregated model that considered different physiological states, including dividing, nondividing, and lysed cells, was developed and applied to experimental data from high cell density cultures of E. coli.
Influence of Polymer Structure on Protein Partitioning in Two‐Phase Aqueous Systems
Authors: Hamad Esam Z. , Ijaz Waseem , Ali Shaik A. , Hastaoglu Mehmet A.
Published: July 2002

Copolymers of acrylamide and styrene with two distinct structures were synthesized to study the effect of polymer structure on protein partitioning in two‐phase aqueous systems. Micellar copolymerization was used to prepare a multiblock copolymer, while homogeneous copolymerization was used to prepare a random copolymer, both with the same composition and molecular weight. Phase behavior studies of the copolymers with poly(ethylene glycol) in water showed little difference in the phase boundaries. However, the partitioning of bovine serum albumin between the two aqueous phases was sensitive to the polymer structure. A molecular picture is proposed for the interactions between the protein and block copolymers. The effect of pH on the protein partition is analyzed in terms of the hydrophobic interactions, and the polymer and protein partitioning was correlated using a model based on the Flory−Huggins theory.
HLA class II antigens in South African Blacks with type I diabetes
Authors: Pirie F.J. , Hammond M.G. , Motala A.A. , Omar M.A.K.
Published: July 2002

Abstract: Type 1 diabetes mellitus is poorly characterised in many African communities, including South Africa, where little is known of the disease epidemiology. This study aimed to identify the HLA class II alleles associated with type 1 diabetes in a group of Zulu subjects in Durban, KwaZulu‐Natal by PCR‐SSP. The HLA alleles associated with type 1 diabetes included HLA‐DQB*0302 (P<0.0001), DRB1*O9 (P<0.0001), DRB1*04 (P=0.002), DRB1*0301 (P=0.003), DQB*02 (P=0.004) and DQA*03 (P=0.035). Estimated haplotypes positively associated with type 1 diabetes included HLA‐DRB1 *0301‐DQA*0501, DRB1*04‐DQA*03, DRB1*04‐DQB*0302, DRB1*0301‐DQB*0201, DQA*0501‐DQB*0201 and DQA*03‐DQB*0302. These findings are similar to those reported from Zimbabwe and other populations with type 1 diabetes.
Excimer laser etching of transparent conducting oxides
Authors: Lunney James G. , O’Neill Richard R. , Schulmeister Karl
Published: July 2002

Laser etching of transparent conducting films of fluorine-doped tin oxide and indium-tin oxide has been investigated using an excimer laser at 248 nm. The etch depth per pulse as a function of laser fluence was measured and compared with the predictions of an explicit finite difference thermal model. Direct laser patterning of these films was demonstrated. The sheet resistance of a 50-μm-wide conducting channel formed by laser ablation was measured and compared with the value for the original film.
Magnetic circular dichroism at the M2,3 edges in three-dimensional transition metals and their compounds
Authors: Koide T. , Shidara T. , Fukutani H. , Yamaguchi K. , Fujimori A. , Kimura S. , Sugimoto T. , Katayama T. , Suzuki Y.
Published: July 2002

The combined utilization of directly characterized off-plane circularly polarized synchrotron radiation and an ultrahigh-vacuum compatible superconducting magnet has enabled magnetic-circular-dichroism (MCD) experiments, mainly at the M2,3 core absorption edges. Details concerning the experimental technique, which allowed quantitative MCD measurements, are described. The results are presented and discussed for single crystals of Ni, Fe, and Fe3O4, and an Fe/Pt multilayer.
A noncontact measurement technique for the density and thermal expansion coefficient of solid and liquid materials
Authors: Chung Sang K. , Thiessen David B. , Rhim Won-Kyu
Published: July 2002

A noncontact measurement technique for the density and the thermal expansion coefficient of refractory materials in their molten as well as solid phases is presented. This technique is based on the video image processing of a levitated sample. Experiments were performed using the high-temperature electrostatic levitator (HTESL) at the Jet Propulsion Laboratory in which 2–3 mm diam samples can be levitated, melted, and radiatively cooled in vacuum. Due to the axisymmetric nature of the molten samples when levitated in the HTESL, a rather simple digital image analysis can be employed to accurately measure the volumetric change as a function of temperature. Density and the thermal expansion coefficient measurements were made on a pure nickel sample to test the accuracy of the technique in the temperature range of 1045–1565 °C. The result for the liquid phase density can be expressed by ρ=8.848+(6.730×10−4)×T (°C) g/cm3 within 0.8% accuracy, and the corresponding thermal expansion coefficient can be expressed by β=(9.419×10−5) −(7.165×10−9)×T (°C) K−1 within 0.2% accuracy.
Nanoscale silicon wires synthesized using simple physical evaporation
Authors: Yu D. P. , Bai Z. G. , Ding Y. , Hang Q. L. , Zhang H. Z. , Wang J. J. , Zou Y. H. , Qian W. , Xiong G. C. , Zhou H. T. , Feng S. Q.
Published: July 2002

We report the large-scale synthesis of silicon nanowires (SiNWs) using a simple but effective approach. High purity SiNWs of uniform diameters around 15 nm were obtained by sublimating a hot-pressed silicon powder target at 1200 °C in a flowing carrier gas environment. The SiNWs emit stable blue light which seems unrelated to quantum confinement, but related to an amorphous overcoating layer of silicon oxide. Our approach can be used, in principle, as a general method for synthesis of other one-dimensional semiconducting, or conducting nanowires.
Local structures of free-standing AlxGa1−xN thin films studied by extended x-ray absorption fine structure
Authors: Yu Kin Man , Shan W. , Glover C. J. , Ridgway M. C. , Wong William S. , Yang W.
Published: July 2002

Local structural information for the first two atomic shells surrounding Ga atoms in free standing AlxGa1−xN alloy films has been obtained by extended x-ray absorption fine structure spectroscopy. For an AlN mole fraction ranging from 0 to 0.6, we found that the first shell Ga–N bond length had only a weak composition dependence, roughly one quarter of that predicted by Vegard’s Law. In the second shell, the Ga–Ga bond length was significantly longer than that of Ga–Al (Δ∼0.04–0.065 Å). A bond-type specific composition dependence was observed for the second shell cation–cation distances. While the composition dependence of the Ga–Ga bond length is ∼70% of that predicted by Vegard’s Law, the Ga–Al bond length was essentially composition independent. These results suggested that local strain in AlxGa1−xN was also accommodated by lattice distortion in the Al cation sublattice.
Exciton spectra of ZnO epitaxial layers on lattice-matched substrates grown with laser-molecular-beam epitaxy
Authors: Makino T. , Chia C. H. , Tuan N. T. , Segawa Y. , Kawasaki M. , Ohtomo A. , Tamura K. , Koinuma H.
Published: July 2002

Optical properties in undoped-ZnO epilayers grown by the laser-molecular-beam epitaxy method on lattice-matched ScAlMgO4 substrates were investigated. The absorption spectrum at 5 K has two sharp peaks, both of which are attributed to resonances of A and B excitons, which reflect a small nonradiative damping constant of excitons as well as high film crystallinity accomplished by the virtue of lattice matching. The coupling strengths of exciton-acoustic phonon and of exciton–longitudinal-optical phonon were directly determined from the temperature dependence of exciton absorption spectra independently for A and B excitons, which are close in energy and obey the same selection rule for each other.
Atomically resolved structure of InAs quantum dots
Authors: Márquez J. , Geelhaar L. , Jacobi K.
Published: July 2002

InAs was grown by molecular-beam epitaxy onto GaAs(001) until quantum dots (QDs) formed. At this point, the growth was interrupted and the uncovered QDs were investigated in situ by scanning tunneling microscopy (STM). Atomically resolved STM images of the QDs revealed that four dominating bounding facets occur, whose Miller indices were identified to be {137}. The assignment of the facet orientation was based on experiments on planar high Miller index GaAs surfaces. In addition, the latter experiments indicated that {137} facets are thermodynamically stable only up to a certain size. This conclusion is assumed to explain the sharp size distribution of InAs QDs.
Dielectric response of concentrated NaCl aqueous solutions: Molecular dynamics simulations
Authors: Zasetsky Alexander Yu. , Svishchev Igor M.
Published: July 2002

Molecular dynamics simulations are performed to study the dielectric response of concentrated NaCl aqueous solutions. The extended simple point charge interaction potential for water molecules and the Higgis–Mayer potential for ion–ion interactions are used. The ion–ion and ion–water distributions are examined for 1 M solution at 298, 373 and 473 K. The solvate-separated ion pairs with the Na+–Cl− separation of about 5.0 Å are found to form preferentially at ambient temperature. The close contact pairs with the ion–ion separation of 2.9 Å tend to form in high temperature solution. The 3D water–ion arrangements are revealed with the aid of the spatial distribution function. The Na+–O–Cl− angle in the solvate-separated ion pairs is found to be close to 106°. The correlation times of translations, τT, and rotations, τR, for water molecules in the solvation shells of the cation and anion are determined. The frequency-dependent dielectric permittivity and absorption coefficient for the concentrated NaCl solution are calculated over wide temperature range. The origin of the complex dielectric spectra for concentrated NaCl solution is analyzed.
Analysis of growing mechanism for MnSb epitaxial films fabricated on a Si substrate by dc sputtering
Authors: Ashizawa Yoshito , Saito Shin , Takahashi Migaku
Published: July 2002

The epitaxial growth and the formation of an interface layer for MnSb sputtered films fabricated on Si (111) single crystal substrates was investigated. It was found that (1) at Tsub=200 °C, MnSb grains grew epitaxially with (101) orientation as the dominant crystal orientation on a Si (111) substrate and (2) at Tsub=250 °C (a) in the thickness region from 0 to 70 nm, a MnSi reacted layer was formed and grown epitaxially with (111) orientation, (b) in the thickness region over 70 nm, MnSb grains were formed and grown epitaxially with c-plane orientation on the MnSi interface layer.
Distribution of nitrogen and defects in SiOxNy/Si structures formed by the thermal nitridation of SiO2/Si
Authors: Vasquez R. P. , Madhukar A. , Grunthaner F. J. , Naiman M. L.
Published: July 2002

Previously reported nitrogen distributions in SiO2 films on Si which have been thermally nitrided at 1000 °C have been explained by a kinetic model of the nitridation process which rests upon the effects of interfacial strain. A critical test of this kinetic model is the validity of the predictions regarding nitrogen distributions obtained at other nitridation temperatures. In this work, nitrogen distributions determined via x-ray photoelectron spectroscopy are reported for samples nitrided at 800 and 1150 °C, and are shown to be consistent with the kinetic model. In addition, the intensity of a fluorine marker is found to correlate with the nitrogen distribution, and is postulated to be related to kinetically generated defects in the dielectric film, consistent with the strain-dependent energy of formation of defects proposed recently to explain electrical data.
Multi-ion crystal field analysis: Methodology and application to (ErxPr1−x)2Fe14B (invited)
Authors: Boltich E. B.
Published: July 2002

The advent of Nd2Fe14B has spawned considerable interest in multi-ion crystal field calculations, since it is the rare-earth crystal field interaction which, in the main, gives rise to the high magnetocrystalline anisotropy necessary for a permanent magnet material. To properly analyze this system, multi-ion calculations are required, due to the fact that the rare-earth ions occupy two crystallographically inequivalent sites, each of which is fourfold degenerate. In the first part of this paper, we describe a procedure for performing multi-ion crystal field calculations which is based on the use of space group transformation matrices to generate both the positions and local axes of the crystallographically equivalent ions. The principal advantage of this method is that all symmetry information can be imported from data files, rather than being coded into the computer program, allowing for a program which is completely structure independent. Another advantage is the ease with which mixed rare-earth systems [such as (ErxPr1−x)2Fe14B ] can be analyzed. In the second part of the paper, we present results obtained by the above described method for the system (ErxPr1−x)2Fe14B, including predictions of both the low-temperature magnetic structure and the magnetic phase diagram.
A novel superlattice infrared source
Authors: Liu H. C.
Published: July 2002

A novel superlattice infrared source is proposed. The device utilizes radiative intersubband transitions and resonant tunneling phenomena in a finite superlattice. Theoretical estimates of the radiative transition lifetime and resonant tunneling time are given, which show the possibility of obtaining an infrared light-emitting diode, or even a laser. The device has a narrow emission spectrum, and the wavelength can be adjusted by varying device parameters. The device design has no long wavelength limitation. A specific design of an AlGaAs-GaAs 10-μm superlattice infrared source is discussed.
Infrared (Er)BaY2F8 laser pumped through di- and tri-ionic upconversion processes
Authors: Pollack S. A. , Chang D. B. , McFarlane R. A. , Jenssen H.
Published: July 2002

Emission and absorption spectra of (5% Er) BaY2F8 were studied at 300, 77, and 4.2 °K. Stark-level positions were determined from the liquid-helium absorption spectra. Emission spectra were excited with a UV flash lamp and 1.53-μm radiation from an Er:glass laser; in the latter case, the visible and near-IR fluorescence of the Er3+ ions was excited through a multiphoton upconversion process. The lifetimes of Er3+-ion-excited states were measured at 300 and 77 °K. Laser action was stimulated at 0.85, 1.73, and 2.796 μm in a (5% Er) BaY2F8 laser rod using the transitions 4S3/2→4IJ, where J=13/2, 9/2, and 4I11/2→4I13/2, respectively. A Xe flash lamp was used for optical pumping. The latter two laser transitions were also pumped through upconversion of 1.53-μm radiation of the Er:glass laser. The cross-relaxation ion-pair conversion coefficient for the 4I13/2 levels of the Er3+ ions in BaY2F8 was calculated to be α=3.7×10−17 cm−3 s−1.
Pseudo moiré dislocations appearing in x-ray diffraction topography
Authors: Yoshimura J.
Published: July 2002

In recent x-ray moiré topographic experiments a dislocationlike discontinuity of moiré fringes has been found despite the fact that specimens (Si bicrystal) were dislocation free. This discontinuity, although similar in appearance to the fringe discontinuity known as moiré dislocation, should be essentially distinguished from it. Preliminary considerations suggest that the outbreak of such pseudo-moiré dislocations is related not only to the wave-field phase due to the moiré effect, but to the phase of extinction fringes. Pseudo-moiré dislocations commonly occur in plane-wave x-ray moiré topography of slightly strained specimens.