bluuebunny/crossref_metadata_2025_split huggingface dataset:
A phase‐model of the cross‐cultural learning process of LIS international doctoral students: Characteristics and interventions
Authors: Mehra Bharat 
Published: October 2006

AbstractThis paper develops a phase‐model of the cross‐cultural learning process of LIS international doctoral students and provides a consolidated, in‐depth, and comprehensive look at their experiences that extends prior anecdotal and survey‐based efforts. Semi‐structured interviews along with informal discussions, analysis of electronic interactions, and observations as a participant researcher identify cross‐cultural learning experiences of all the twenty‐two international doctoral students from a representative LIS program in the United States. The phases in the model of the cross‐cultural learning process represent significant cognitive (thoughts), affective (feelings), and physical (actions) aspects of the experiences of LIS international doctoral students. Mapping participants' concerns and challenges during each phase is used to highlight interventions at the level of discipline, program, faculty, doctoral student community, and individual student that together provide a practical application to the research. Proposed interventions need to be holistically applied in conjunction with each other to promote mutual “two‐way” learning where international students learn from the discipline and the discipline learns from the international students. Such an approach suggests symbiotic connections between improvements in effectiveness of student learning and efforts to tap into the cultural knowledge of international students to further growth in internationalization of LIS education in the United States.
Automated analysis of database usage logs in a metasearch environment: The library of Texas experience
Authors: Oguz Fatih , Moen William E. 
Published: October 2006

AbstractThe poster presents an overview of a research and development effort for a mechanism to produce reliable usage reports for the Library of Texas (LOT) Resource Discovery Service (RDS) metasearch application. The RDS Log Analyzer was designed and implemented by the Texas Center for Digital Knowledge project team as part of a contract with the Texas State Library and Archives Commission to support the LOT RDS. Developers of the RDS application had requirements to implement a mechanism for capturing RDS user transactions in custom log files.
Inter‐database annotation linkages in model organism databases
Authors: MacMullen W. John 
Published: October 2006

AbstractInter‐database linkage via annotations is one approach to the integration of knowledge in the biomedical domain, which is often fragmented by specialization. This pilot study examined annotations in ten model organism databases and the Gene Ontology (GO) to assess explicit and implicit linkages between organisms. The databases had similar annotation processes, content, and knowledge, with some variation due to organizational objectives and technology infrastructure. While all databases had the potential to be linked to all others via GO, only some databases had non‐GO links to others. This may be due in part to a lack of biologically significant relationships among some of the organisms, or that putative relationships between them that exist in GO have not yet been explored.
Information science practice in a historical perspective: Preliminary findings of an oral history project
Authors: Pozzi Ellen , Dalbello Marija 
Published: October 2006

AbstractOral history is a phenomenological method of historical inquiry. It is applied to the study of the organizational field of information science through interviews with members of the New Jersey chapter of the national information science organization )ASIST). Their views on the identity of the chapter and their own professional identity in that context, and on the development and maturation of information science field over the past thirty years are considered in the sociology of culture framework. This approach can open new directions for historical inquiry of information science in the national context, understanding the research / practice dynamics, and the institutionalization of information science field.
MARTT: Using induced knowledge base to automatically mark up plant taxonomic descriptions with XML
Authors: Cui Hong 
Published: October 2006

AbstractDespite the sub‐language nature of taxonomic descriptions of plants, researchers warned about the large variations among different collections of descriptions in terms of information contents and presentations. These variations impose a serious challenge to the development of automatic tools for the semantic markup of large volumes of free‐text descriptions. This paper presents a new approach to automatic markup of multiple collections of taxonomic descriptions with XML. The effectiveness of the approach was demonstrated with markup experiments using three contemporary floras. The markup system, MARTT, was based on supervised machine learning algorithms and enhanced by machine learned association rules representing certain types of domain knowledge and conventions. Experiments showed that our simple and efficient markup algorithm outperformed popular general‐purpose algorithms (including SVMs) across different floras. More importantly, the results demonstrated that the domain knowledge learned from one flora was useful for improving the markup performance on a second flora, especially on elements with sparse training examples. The system design and the evaluation of markup algorithms are reported in this paper. The study on the effectiveness of the induced knowledge base will be reported in a later paper. In this paper, common practices of flora authors and the potentials of MARTT system for improving the efficiency and effectiveness of the creation, organization, and utilization of plant descriptions are also discussed.
Concentrations and magnetization transfer ratios of metabolites in gray and white matter
Authors: McLean Mary A. , Barker Gareth J. 
Published: October 2006

AbstractThe concentrations and magnetization transfer ratios (MTRs) in gray matter (GM) and white matter (WM) of N‐acetyl aspartate (NAA), creatine (Cr), choline (Cho), myo‐inositol (Ins), and glutamate plus glutamine (Glx) were investigated using magnetic resonance spectroscopic imaging (MRSI). The macromolecule (MM) baseline was studied separately using a metabolite‐nulling inversion. Three data sets were collected from a point‐resolved spectroscopy (PRESS)‐selected volume (TE/TR = 30/3000 ms) of human frontal lobe in vivo: one with MT pulses applied, one with an inversion pulse to null small metabolites, and one with no inversion or MT pulses. The MM signal, which was analyzed by integrating the metabolite‐nulled spectrum between 0 and 3 ppm, was estimated to be 38% higher in GM than in WM. MM subtraction decreased the signal‐to‐noise ratio (SNR) and also decreased the reliability of LCModel quantification of most metabolites, but may have improved the accuracy of quantification of Glx. Glx and Cr were both found to correlate strongly with the GM volume fraction of the voxels. Cr showed the highest MTR, but the other metabolites also showed some attenuation of signal when the MT pulses were applied. The MTRs did not correlate with the GM volume fraction, which implies that the local environment of metabolites does not differ markedly between GM and WM. Magn Reson Med 2006. © 2006 Wiley‐Liss, Inc.
Sources of functional apparent diffusion coefficient changes investigated by diffusion‐weighted spin‐echo fMRI
Authors: Jin Tao , Zhao Fuqiang , Kim Seong‐Gi 
Published: October 2006

AbstractThe mechanism behind previously observed changes in the apparent diffusion coefficient (ADC) during brain activation is not well understood. Therefore, we investigated the signal source and spatial specificity of functional magnetic resonance imaging (fMRI) ADC changes systematically in the visual cortex of cats using diffusion‐weighted (DW) spin‐echo (SE) fMRI with b‐values of 2, 200, and 800 s/mm2, and echo times (TE) of 16, 28, and 60 ms at 9.4 T. For b ≥ 200 s/mm2, no ADC changes were detected in brain parenchyma, suggesting a minimal tissue contribution to the ADC change. For b ≤ 200 s/mm2, TE‐dependent ADC increases were observed. When the venous blood contribution was minimized, the ADC change was higher at the middle cortical layer than at the cortical surface, which is mainly attributed to a functional elevation in arterial blood volume. At TE = 16 ms, the highest ADC changes occurred at the cortical surface with its large draining veins, which can mainly be explained by an additional contribution from the venous blood oxygenation changes. Our TE‐dependent ADC results agree with computer simulations based on a three‐compartment model. The contribution of arterial blood volume changes in ADC fMRI offers an improvement in spatial localization for SE‐BOLD fMRI studies. Magn Reson Med 2006. © 2006 Wiley‐Liss, Inc.
Pyrrolizidine alkaloids from Senecio leucanthemifolius and Senecio rodriguezii
Authors: Roeder Erhard , Bourauel Thomas 
Published: October 2006

AbstractTwo toxic pyrrolizidine alkaloids were isolated from Senecio leucanthemifolius and six from Senecio rodriguezii. Their structures were determined by spectroscopic methods. © 1992 Wiley‐Liss, Inc.
Cytolysins increase intracellular calcium and induce eicosanoids release by pheochromocytoma PC12 cell cultures
Authors: Raya Saleh Abu , Trembovler Victoria , Shohami Esther , Lazarovici Philip 
Published: October 2006

AbstractCytolysins are the most commonly occurring toxins among bacteria, plants, and animals. By disturbing cell membrane, they impair ionic permeability, leading to cell death. In an attempt to investigate cytolysin action on catecholaminergic neurons, we have treated pheochromocytoma cell cultures with Strep‐tolysin S, Staphylococcus aureus α and δ, Stoichatus, Parcelsin, and cobra direct lytic factor. To measure neurotoxicity, PC12 cultures were loaded with 51Cr and exposed for 1 hr at 37°C to different concentrations of cytolysins. Cytotoxic dose‐response curves have been generated resulting in CD50 (cytotoxic dose 50%) in the range of 1–50 μg toxin/culture. Using subcytotoxic concentrations of cytolysins (which are of clinical relevance), changes on intracellular calcium were measured by Fura‐2 fluorescence technique. Addition of either Stoichatus toxin and tetanolysin or streptococcus and staphylococcus cytolysins to PC12 cells caused rapidly or gradually a progressive increase in [Ca2+]i, respectively. Under similar conditions, samples of PC12 culture medium were assayed for 3H‐arachidonic acid released and by radioimmunoassay for the content of PGE2 (prostaglandin), TXB2 (stable metabolite of thromboxane), and 5‐HETE (hydroxy acid lipoxygenase product). PLA2 was activated 4.5–6.0‐fold and the levels of all three eicosanoids were increased by 2.5–9‐fold (PGE2), 4–6‐fold (TXB2), and over 100‐fold (5‐HETE) by Stoichatus and Parcelsin cytolysins. Upon treatment with Streptolysin S and staphylococcus α toxins PLA2 (phospholipase A2) was slightly activated (1.5‐fold) and the levels of PGE2 and TXB2 increased 1.3–2.0‐fold and that of 5‐HETE up to 30‐fold. These results indicate that the increased intracellular calcium followed by PLA2 activation and eicosanoid production and release might be involved in neurotoxic action of cytolysins. © 1992 Wiley‐Liss, Inc.
Isolation and sequence analysis of peptides from the venom of Protonectarina sylveirae (hymenoptera‐vespidae)
Authors: Dohtsu Kunihiko , Okumura Kaoru , Hagiwara Ken'Ichi , Palma Mario Sergio , Nakajima Terumi 
Published: October 2006

AbstractThree new venom peptides were isolated from the Brazilian wasp; Protonectarina sylveirae and their complete amino acid sequences were determined by Edman degradation as well as by FAB‐mass spectrometry. One (P‐8) of them was a new analog of mastoparan family; therefore, we named it Protonectarina mastoparan. Another peptide (P‐10) had an amino acid sequence homolosy with Ves‐CP‐T, a chemotactic peptide of wasp venom, and bombolitin‐V, the venom peptide from bumblebee. The third peptide (P‐6) was structurally unique, possessing an intramolecular disulfide bond. Not only Protonectarina mastoparan (P‐8) but also P‐6 and P‐10 caused histamine release from rat peritoneal mast cells as potently as mastoparan (EC50 s were about 1 × 10−6 M for P‐6 and 2 × 10−6 M for P‐10). In addition, P‐10 in a concentration higher than 1 × 10−5 M induced hemolysis though whose hemolytic activity was about a half potency of that of mastoparan. However, P‐6 did not cause hemolysis up to the concentration of 10μM. We have named them sylverin for the peptide P‐6 and protonectin for the peptide P‐10. © 1992 Wiley‐Liss, Inc.
Toxicity of cotton phytoalexins to zoopathogenic fungi
Authors: Mace Marshall E. , Stipanovic Robert D. , Bell Alois A. 
Published: October 2006

AbstractThe sesquiterpenoid phytoalexins desoxyhemigossypol, desoxymethoxyhemigossypol, and hemigossypolone formed in cotton (Gossypium hirsutum and G. barbadense) stem xylem infected with Verticillium dahliae were shown to be highly toxic to zoopathogenic fungi. This appears to be the first study of the toxicity of terpenoid phytoalexins to zoopathogenic fungi. The toxicities of the phytoalexins expressed as MIC (μg ml−1) values were 8 to 128 against four isolates of Candida albicans and one isolate of Cryptococcus neoformans. These highly toxic compounds or their derivatives may prove useful for the treatment of animal mycoses. © 1992 Wiley‐Liss, Inc.
Occurrence of nivalenol, deoxynivalenol, and zearalenone in imported cereals in Papua, New Guinea
Authors: Yuwai Kuri E. , Rao Koyyalamudi Sundar , Singh Kirpal , Tanaka Toshitugi , Ueno Yoshio 
Published: October 2006

AbstractA preliminary survey for the natural occurrence of Fusarium mycotoxins—nivalenol (NIV), deoxynivalenol (DON) and zearalenone (ZEN)—in cereals imported mostly from Australia to Papua, New Guinea (PNG) in 1991 was carried out by TLC, GLC, and HPLC analysis. The data have revealed various kinds of cereals and cereal flours, such as wholemeal flour, millet meal, corn flour, brown trukai rice, and others, were significantly contaminated with these mycotoxins in various concentrations. Among these Fusarium mycotoxins, the level of ZEN was surprisingly high. This is the first report on the natural occurrence of Fusarium mycotoxins in PNG cereals. © 1994 wiley‐Liss, Inc.
Interaction of dimethylsulfoxide and arachidonic acid with the teratogenic effects of caffeine in mice
Authors: Reedy Rajasekhar V. , Reedy Chada S. , Fraipier Brian L. , Brimer Gary E. 
Published: October 2006

AbstractDose‐response of the teratogenic effect of caffeine (CA) and the potential role of facial hematomas in the pathogenesis of caffeine‐induced cleft palate were investigated using CD1 mice treated with 150, 200, or 250 mg CA/kg i.p. on gestational day (GD) 12. Dimethylsulfoxide (DMSO; 20%) and arachidonic acid (AA, 200 mg/kg) were administered along with CA (200 mg/kg) to study their interaction with CA‐induced teratogenesis and elevation in maternal glucocorticoids (MGC, measured by RIA) on GD 13 and 14. Dose‐dependent increase in the incidence of cleft palate (CP) was noted in CA‐exposed mice. High maternal deaths, an increased number of resorptions, gross facial hematomas (GFH), and club foot (CF) were produced only by the highest (250 mg/kg) dose of CA. Palates from all offspring with GFH were clefted at this dose level. None of the control or CA‐treated nonclefted offspring had GFH or microscopic hematomas (MH). At 200 mg/kg of CA, DMSO in combination with CA actually increased CA‐induced CP from 30% to 100% and also produced 100% GFH as compared to 0% by CA alone at this dose. Greater than 50% of clefted offspring without GFH, given either dose (200 or 250 mg/kg) of CA, had MH. Very high levels of MGC were present in CA‐treated mice on GD 13 and 14. Although simultaneous administration of DMSO reduced the magnitude of CA‐induced MGC elevations on GD 14, the MGC levels remained high for greater than 24 hours following CA exposure. Increase in maternal mortality and fetal resorptions, a decrease in the number of live pups and their body weights, and no change in the incidence of CP were seen when CA‐treated mice were simultaneously exposed to AA. These results suggest a correlation between caffeine‐induced FH and CP; a role for increased hematomagenic effects of DMSO in its potentiation of the cleft‐palatogenic effect of caffeine; and absence of a role for AA‐mediated effects of MGC in the causation of CA‐induced CP and other malformations. © 1994 Wiley‐Liss, Inc.
Genetic relatedness of toxic and nontoxic isolates of the marine pennate diatom Pseudonitzschia (bacillariophyceae): Phylogenetic analysis of 18S rRNA sequences
Authors: Douglas Donald J. , Landry Denise , Douglas Susan E. 
Published: October 2006

AbstractThe nuclear small subunit (SSU) rRNA genes from several marine diatoms, including 2 species that have been responsible for toxic blooms, were amplified from total DNA by the polymerase chain reaction (PCR), and the sequences analyses to determine their genetic relatedness. The isolates investigated include 2 morphologically similar forms of the pennate diatom Pseudonitzschia pungens: (1) P. pungens f. multiseries, a known producer of the toxin domoic acid, and (2) P. pungens f. pungens, which is not toxic. Strains of a second toxin‐producing species, P. australis, and a nontoxic Thalassiosira species were also included in this study. Phylogenetic analyses of sequences by both distance and parsimony methods clearly distinguished the 2 forms of P. pungens and the 2 Pseudonitzschia species from other diatoms for which sequence data are available. Differences in the nucleotide sequences of the 2 forms of P. pungens permitted the design of PCR primers that allowed discrimination between them. This may prove a valuable tool in identifying toxic and nontoxic forms of closely related and morphologically similar diatom species. Published 1994 Wiley‐Liss, Inc.
Salt clean‐up procedure for the determination of domoic acid by HPLC
Authors: Hatfield Christine L. , Wekell John C. , Gauglitz Erich J. , Bamett Harold J. 
Published: October 2006

AbstractDomoic acid (DA) was first reported in mussels from Prince Edward Island, Canada, in 1987. It reappeared in anchovies and pelicans from Monterey Bay, California, in 1991. Later that year, domoic acid was found in razor clams and Dungeness crabs along the Washington and Oregon coasts. Since the initial outbreak, a variety of analytical methods for the detection of this neurotoxin have been developed. Here, we describe a modification to the solid phase extraction (SPE) clean‐up step in Quilliam's HPLC‐UV method (1991: NRCC No. 33001). The standard 10% acetonitrile (MeCN) wash and 0.5M ammonium citrate buffer (ACB) in 10% MeCN (pH = 4.5) eluting solution have been replaced with a 0.1 M sodium chloride (NaCI) in 10% MeCN wash and a 0.5M NaCI in 10% MeCN eluting solution. This modification allows the analysis to work equally well on both clam and crab viscera and meat. Chromatograms of visceral samples no longer contain interfering or late eluting peaks; and all Chromatograms are free of the large solvent peak tailing associated with the ACB eluent. The newly modified method allows for an improved and more versatile domoic acid analysis. © 1994 Wiley‐liss, Inc.
Growth and toxin production of the toxic dinoflagellate Pyrodinium bahamense var. compressum in laboratory cultures
Authors: Usup Gires , Kulis David M. , Anderson Donald M. 
Published: October 2006

AbstractToxin production of a Malaysian isolate of the toxic red tide dinoflagellate Pyrodinium bahamense var. compressum was investigated at various stages of the batch culture growth cycle and under growth conditions affected by temperature, salinity, and light intensity variations. In all the experiments conducted, only 5 toxins were ever detected. Neosaxitoxin (NEO) and gonyautoxin V (GTX5) made up 80 mole percent or more of the cellular toxin content and saxitoxin (STX), GTX6 and decarbamoylsaxitoxin (dcSTX) made up the remainder. No gonyautoxins I‐IV or C toxins were ever detected. In nutrient‐replete batch cultures, toxin content rapidly peaked during early exponential phase and just as rapidly declined prior to the onset of plateau phase. Temperature had a marked effect on toxin content, which increased 3‐fold as the temperature decreased from the optimum of 28°C to 22°C. Toxin content was constant at salinities of 24%° or higher, but increased 3‐fold at 20%°. Toxin content decreased 2‐fold and chlorophyll content increased 3‐fold when light intensity was reduced from 90 to 15 μE m‐2 s‐1. This accompanied a 30% decrease in growth rate. Toxin composition (mole % individual toxin cell‐1) remained constant throughout the course of the nutrient‐replete culture and during growth at various salinities, but varied significantly with temperature and light intensity changes. At 22°C, GTX5 was 25 mole % and NEO was 65 mole %, while at 34°C, GTX5 increased to 55 mole % and NEO decreased proportionally to 40 mole %. When light intensity was reduced from 90 to 15 μE m‐2 s‐1, NEO decreased from 55 to 38 mole %, while GTX5 increased from 40 to 58 mole %. These data suggest that low light and high temperature both somehow enhance sulfo‐transferase activity. In general, toxin content and composition in P. bahamense were both influenced by factors that alter the growth rate of the species. The data show, however, that toxin content was not determined solely by growth rate but, more likely, by the manner in which the cells allocate their nitrogen and carbon to various cellular components and processes under various growth conditions. Several of the toxin production patterns observed in this P. bahamense isolate were similar to those of PSP toxin‐producing Alexandrium and Gyrnnodinium species, but there were also significant differences. © 1994 wiley‐Liss, Inc.
Highly sensitive assay of okadaic acid using protein phosphatase and paranitrophenyl phosphate
Authors: Simon Jean François , Vemoux Jean‐Paul 
Published: October 2006

AbstractA colorimetric phosphatase‐inhibition bioassay was developed for the quantitative measurement of okadaic acid (OA) the main diarrhetic toxin responsible for diarrhetic shellfish poisoning. The assay used an artificial substrate, paranitrophenylphosphate, and a semi‐purified protein phosphatase PP2Ac containing extract prepared from rabbit muscle. Calibration dose‐inhibition curves were constructed using standard OA and they permitted easy determination of the enzyme concentration Et in their linear portion. In the range of linearity, the slope increased when Et decreased, thus giving a detecting limit of 0.04 pmol in the reaction mixture (1 ml). The lowest assayable concentration of OA was 4 ng/ml in aqueous solutions and 40 ng/ml (i.e., 100 ng of OA per g of mussel tissue) in crude methanol mussels extracts. The infra and interassay coefficients of variation in the measurement of OA for the toxin spiked aqueous samples averaged, respectively, 7.7% and 3.7%, and interexperiments coefficients of variation for the toxin spiked mussel extracts averaged 4.6%. The presence of OA was ascertained by a method in which one assay was performed at two or three different levels of enzyme concentration. The rapidity, accuracy, reproducibility, specificity, and simplicity of the procedure provides a simple way to assay okadaic acid in buffered or complex solutions. © 1994 wiley‐Liss, Inc.