bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coupling of TiO2‐mediated enrichment and on‐bead guanidinoethanethiol labeling for effective phosphopeptide analysis by matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Ahn Yeong Hee , Ji Eun Sun , Lee Ji Yeon , Cho Kun , Yoo Jong Shin 
Published: November 2007

AbstractTitanium dioxide (TiO2)‐mediated phosphopeptide enrichment has been introduced as an effective method for extracting phosphopeptides from highly complex peptide mixtures. Chemical labeling by β‐elimination/Michael addition is also useful for increasing mass intensity in phosphopeptide analysis. Both of these methods were coupled in order to simultaneously enrich phosphopeptides and allow for detection and sequencing of the enriched peptides with high mass sensitivity. Phosphopeptides were successfully enriched on TiO2 beads without the use of any hydroxy acid additives like 2,5‐dihydroxybenzoic acid. Labeling was accomplished on‐bead with a guanidinoethanethiol (GET) tag containing a guanidine moiety. These GET‐labeled derivatives were detected by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS). GET labeling converted phosphoserine into guanidinoethylcysteine, a structural arginine‐mimic. In particular, GET‐labeled lysine‐terminated phosphopeptides showed dramatically increased peak intensities compared to those of the corresponding intact phosphopeptides. Additionally, the on‐bead labeling minimized manipulation steps and sample loss. The coupled technique was also further validated by applying to the analysis of phosphopeptides from complex tryptic digests of phosphoprotein mixtures. Copyright © 2007 John Wiley & Sons, Ltd.
Determination of dithiocarbamate fungicide residues by liquid chromatography/mass spectrometry and stable isotope dilution assay
Authors: Crnogorac Goranka , Schwack Wolfgang 
Published: November 2007

AbstractA rapid and very sensitive high‐performance liquid chromatography/electrospray ionization mass spectrometry (LC/ESI‐MS) method for the simultaneous determination of dithiocarbamate (DTC) fungicide residues in fruits and vegetables was developed. The surface extraction of samples used an alkaline buffer consisting of sodium hydrogen carbonate and DL‐penicillamine. The three DTC subclasses, i.e. dimethyldithiocarbamates (DMDs), ethylenebis(dithiocarbamates) (EBDs), and propylenebis(dithiocarbamates) (PBDs), were separated on a Sequant ZIC‐pHILIC column using an acetonitrile/10 mM ammonia gradient. Because of the instability of DTC residues extracted from plant samples, a stable isotope dilution assay was applied. For each DTC subclass, the limits of detection and quantification were approximately 0.03 mg kg−1 and 0.05 mg kg−1, respectively. Recoveries from grapes, cucumbers, tomatoes, and rucola, spiked in the range of 0.01–0.9 mg kg−1, averaged between 90 and 100%. Copyright © 2007 John Wiley & Sons, Ltd.
Simple and sensitive quantification of bioactive peptides in biological matrices using liquid chromatography/selected reaction monitoring mass spectrometry coupled with trichloroacetic acid clean‐up
Authors: Murao Naoaki , Ishigai Masaki , Yasuno Hideyuki , Shimonaka Yasushi , Aso Yoshinori 
Published: November 2007

AbstractA simple and sensitive liquid chromatography/electrospray ionization tandem mass spectrometric (LC/ESI‐MS/MS) method has been developed for the quantification of bioactive peptides in biological fluids. The method employs protein precipitation with 4% trichloroacetic acid (TCA) and selected reaction monitoring (SRM) using an immonium ion as the product ion. This method was applied to determine the synthetic parathyroid hormone (PTH) analog (MW 1721) in rat plasma and human hepcidin‐25 (MW 2789) in human serum. TCA clean‐up showed a sufficient recovery for peptides with a MW of less than 3000, and would be useful as a simple and rapid method because of direct injection of the supernatant without evaporation or dilution. In addition, TCA clean‐up allowed us not only to reduce sample preparation time, but also to select an immonium ion as a product ion of SRM, which led to detection more sensitive than SRM using other types of product ions. The lower limits of quantitation (LLOQs) of the PTH analog and the human hepcidin‐25 were 0.2 ng/mL and 5 ng/mL, respectively. This method was fully validated with acceptable linearity, intra‐ and inter‐assay precisions, and accuracy. Furthermore, this simple and rapid method is applicable to pharmacokinetic studies. Copyright © 2007 John Wiley & Sons, Ltd.
Learning‐goals‐driven design model: Developing curriculum materials that align with national standards and incorporate project‐based pedagogy
Authors: Krajcik Joseph , McNeill Katherine L. , Reiser Brian J. 
Published: November 2007

AbstractReform efforts in science education emphasize the importance of rigorous treatment of science standards and use of innovative pedagogical approaches to make science more meaningful and successful. In this paper, we present a learning‐goals‐driven design model for developing curriculum materials, which combines national standards and a project‐based pedagogical approach. We describe our design model in the context of the Investigating and Questioning our World through Science and Technology (IQWST) project, which is developing a three‐year coordinated series of middle grades science curriculum materials. From using this model in the development and enactment of the curriculum, we identified three important characteristics: unpacking national science standards, developing a learning performances approach to specifying learning goals, and aligning learning goals, instructional activities, and assessments. Using a case study of an IQWST unit from initial development through two cycles of enactment, we describe how these three characteristics help guide curriculum design, identify design issues in curriculum enactments, and guide the development of design solutions. The iterative use of the learning‐goals‐driven design model coupled with the analysis of multiple data sources informed our revision of the curriculum materials, resulting in substantial student learning gains for the targeted science content and scientific inquiry learning goals. © 2007 Wiley Periodicals, Inc. Sci Ed 92:1–32, 2008
Powerful learners and critical agents: The goals of five urban Caribbean youth in a conceptual physics classroom
Authors: Basu Sreyashi Jhumki 
Published: November 2007

AbstractYouth from low‐income, minority backgrounds have often been marginalized from introductory courses, advanced study and careers in physics. Cultivating student agency may have the potential to improve access for diverse groups of learners. However, the implications of this lens for student learning have been minimally examined in the physics education literature. In this ethnographic study situated in a ninth‐grade conceptual physics classroom, I discuss students' critical goals—the intentions, motivations, and desires for change that youth held. These critical goals were related to learning, voice, and participation in relationships and the world. I also describe how student goals demonstrate the idea of “critical subject‐matter agency” in physics: students positioning themselves as powerful learners envisioning subject knowledge as a tool for change in their own lives and world. © 2007 Wiley Periodicals, Inc. Sci Ed 92:252–277, 2008
Determination of toxicity of subacute treatment of some plant growth regulators on rats
Authors: Celik Ismail , Tuluce Yasin 
Published: November 2007

AbstractThe effects of some plant growth regulators (PGRs), 2,3,5‐triiodobenzoic acid (TIBA), Naphthaleneacetic acid (NAA) and 2,4‐Dichlorofenoxyacetic acid (2,4‐D), at sublethal concentrations on antioxidant defense system [glutathione peroxidases (GPx), reduced glutathione (GSH), glutathione reductase (GR), glutathione‐S‐transferase (GST) and catalase (CAT)], immune potential enzymes [adenosine deaminase (ADA) and myeloperoxidase (MPO)], and lipid peroxidation content [Malondialdehyde, (MDA)] were investigated in lung and speen tissues of rats. Sprague‐Dawley albino rats were exposed to 0, 50, or 100 ppm (parts per million) TIBA, NAA, or 2,4‐D in drinking waterad libitumfor 25 days continuously. According to the results, MDA concentration significantly increased in the tissues treated with 100 ppm dosage of NAA or 2,4‐D without any change in the tissues of rats treated with both dosage of TIBA. The GSH depletion in the spleen tissue of rats treated with both the dosage of NAA and 2,4‐D were found to be significant. Also, GSH level in the spleen was significantly reduced with 100 ppm of 2,4‐D and NAA. The activity of antioxidant enzymes were also seriously affected by PGRs; GPx significantly decreased in the lung of rats treated with both dosages of the PGRs, whereas GPx activity in the spleen were significantly increased with 100 ppm dosage of 2,4‐D and NAA. On the other hand, CAT activity significantly decreased in the lung of rats treated with both dosages of NAA, 100 ppm of 2,4‐D and 50 ppm of TIBA, and also in the spleen treated with 50 ppm NAA and 2,4‐D. The ancillary enzyme GR activity significantly decreased in the spleen with both doses of the PGRs, also in the lung treated with both dosages of 2,4‐D, 50 ppm of NAA and 100 ppm of TIBA. The drug metabolizing enzyme GST activity significantly reduced in the lung of rats treated with both dosages of the PGRs and also in the spleen treated with 100 ppm dosage of 2,4‐D and TIBA and 50 ppm of NAA. Meanwhile, immune potential enzyme MPO activity significantly increased in the spleen of rats treated with both doses of NAA and TIBA whereas ADA activity significantly decreased in the spleen of rats treated with 100 ppm dose of NAA and TIBA. The observations presented led us to conclude that the administrations of subacute NAA, 2,4‐D, and TIBA promote MDA content, inhibit the antioxidative defense system and activate or inhibit immune potential enzymes in the rat's spleen and lung tissues. These data suggest that PGRs produced substantial organ toxicity in the lung and spleen during the period of a 25‐day subacute exposure. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 613–619, 2007.
Toxic effect of arsenate and cadmium alone and in combination on giant duckweed (Spirodela polyrrhiza L.) in response to its accumulation
Authors: Seth Chandra Shekhar , Chaturvedi Pranav Kumar , Misra Virendra 
Published: November 2007

AbstractTo evaluate the biological effects of wastewater samples containing heavy metals, the effects of metal Cd (II) and As (V) were studied on Spirodela polyrrhiza L. The plants were exposed at metal concentrations 0.1, 0.5, 1, 2 μM of Cd (II) and 1, 5, 10, 20 μM of As (V) for a period of 1, 4, 7 d (day) alone and in combination of both. Plants accumulated 1855 mg kg−1 dw (dry weight) Cd and 1230 mg kg−1 dw As after 7 d in alone, whereas it was 885 mg kg−1 dw Cd and 865 mg kg−1 dw As in combination. The toxicological parameters such as fresh biomass, photosynthetic pigments, and total protein contents increased up to 2 μM of Cd (II) after 1 d and 10 μM of As (V) after 4 d with respect to control (Hormesis effect), followed by gradual decline at higher concentrations and duration. In case of Cd (II) a maximum decrease of 58% in protein content, 62% in fresh biomass, and 78% in total chlorophyll was observed at 2 μM, whereas, with As (V) 38% decrease in protein content, 34% in fresh biomass, and 52% in total chlorophyll was shown at 20 μM after 7 d. The metal tolerance strategy against metal induced reactive oxygen species adopted by the plants was investigated with reference to nonprotein thiols (NP‐SH), cysteine, and ascorbic acid. The results of combined treatment revealed reduced toxicity at the level of fresh biomass, protein content, and chlorophyll; however, the amount of nonenzymatic antioxidant did not significantly (P = 0.172) increase as compared to alone treatment. Finally, it was concluded that due to high metal accumulation coupled with defense potential, the plant appears to have a potential for its use as phytoremediator species of aquatic environments. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 539–549, 2007.
Ecological relevance and sensitivity depending on the exposure time for two biomarkers
Authors: Campero Melina , Ollevier Frans , Stoks Robby 
Published: November 2007

AbstractBiomarkers are widely used to assess pesticide stress, but their ecological relevance and exposure time dependent sensitivity is still heavily debated. We studied both aspects in larvae of the damselfly Coenagrion puella, comparing the impact of low doses of atrazine, carbaryl, and endosulfan on two key biomarkers (acetylcholinesterase [AChE] activity and fluctuating asymmetry [FA]) and their relationship with life history traits (mortality, development time, growth rate, and body size). Larvae exposed to the pesticides had, in general, longer development times. Size, growth rate, and mortality were not affected by any of the pesticides. In the long‐term exposure, AChE activity was diminished by atrazine treatments and stimulated by carbaryl treatments, and was not affected in the endosulfan treatments. FA decreased with increasing endosulfan concentrations and showed no reaction to atrazine or carbaryl. Overall, short‐term exposure tended to overestimate the results of long‐term exposure decreasing growth rates and enhancing inhibition of AChE activity in atrazine and carbaryl treatments. In line with its ecological relevance, relationship between biomarkers and life history traits showed that AChE inhibition was positively correlated with mortality, while FA was traded off with size. These results show that caution should be exerted when using these biomarkers to assess pesticide pollution in field situations. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 572–581, 2007.
A New Image Analysis Based Method for Measuring Electrospun Nanofiber Diameter
Authors: Ziabari Mohammad , Mottaghitalab Vahid , McGovern Scott T , Haghi AK 
Published: November 2007

Abstract
In this paper, a new image analysis based method for electrospun nanofiber diameter measurement has been presented. The method was tested by a simulated image with known characteristics and a real web. Mean (M) and standard deviation (STD) of fiber diameter obtained using this method for the simulated image were 15.02 and 4.80 pixels respectively, compared to the true values of 15.35 and 4.47 pixels. For the real web, applying the method resulted in M and STD of 324 and 50.4 nm which are extremely close to the values of 319 and 42 nm obtained using manual method. The results show that this approach is successful in making fast, accurate automated measurements of electrospun fiber diameters.
Melting Points and Viscosities of Fatty Acid Esters that are Potential Targets for Engineered Oilseed
Authors: Yao Linxing , Hammond Earl , Wang Tong 
Published: November 2007

AbstractOur previous isolation of branched‐chain fatty acid (BCFA) methyl esters from lanolin was improved and scaled up. Also, oleate esters of isopropanol, oleyl alcohol and normal alcohols of 1–12 carbons chain lengths were prepared. Esters were made by interesterification with sodium alcoholates and by esterification with Candida antarctica lipase. It proved easier to obtain pure esters by the enzymatic synthesis. Melting points and viscosities over the range of 0–70 °C were determined in order to better identify potential lubricant targets that might be produced by genetically modified oilseed crops. Isopropyl and butyl oleate have melting points of −33 and −32 °C, respectively and viscosities that range from ~17 cp (0 °C) to ~2.5 cp (70 °C). They should have suitable stability for lubricants. BCFA esters had viscosities similar to their straight chain analogs. Viscosities increased with alcohol chain length and decreased with temperature. The dependence of viscosity on temperature was fit with an equation based on Erying’s rate equation. Some esters with branched acid or branched alcohol moieties, and some oleate esters might be utilized as biolubricants or biofuels on the basis of their melting points and viscosities.
Reproductive biology of the Brazilian sharpnose shark (Rhizoprionodon lalandii) from southeastern Brazil
Authors: Motta Fabio S. , Namora Rafael C. , Gadig Otto B. F. , Braga F. M. S. 
Published: November 2007

Abstract
Motta, F. S., Namora, R. C., Gadig, O. B. F., and Braga, F. M. S. 2007. Reproductive biology of the Brazilian sharpnose shark (Rhizoprionodon lalandii) from southeastern Brazil. – ICES Journal of Marine Science, 64: 1829–1835. The reproductive biology of the Brazilian sharpnose shark, Rhizoprionodon lalandii, off southeastern Brazil was investigated using data from gillnet landings. The size-at-maturity for males and females was estimated to be 59 and 62 cm total length (LT), respectively. Ovarian fecundity ranged from 3 to 7 follicles (mean = 4.54), and uterine fecundity from 1 to 5 embryos (mean = 3.3). There was a slight positive relationship between female LT and the number of ovarian follicles, but uterine fecundity was not related to female LT. Embryonic growth is fast following fertilization during summer and autumn. Gestation requires 11–12 months, and peak parturition is between August and September. A comparison of size-at-maturity between animals from northeastern and southeastern Brazil suggests the existence of at least two stocks of R. lalandii along the Brazilian coast.
Time trends in suicide mortality J in Lithuania
Authors: Kalediene R. 
Published: November 2007

Objective: The aim of this study was to analyse the time trends of suicides during the period 1970–1995 in Lithuania, and to assess the importance of the effects of age, period and birth cohort as risk factors.Method: Trends in suicides and average annual changes were based on logarithmic regression analysis. For assessment of the effects of age, period and birth cohort on suicide mortality, a log‐linear regression model with parameters representing age, period and cohort effects was fitted.Results: Between 1970 and 1995 age‐standardized suicide rates almost doubled. There was an increase in suicides in birth cohorts of males from 1910 to 1950, and in cohorts born after 1965. In females, an increase was observed in all successive birth years from 1905 to 1925 and after 1970. The period effect in males and the cohort effect in females were dominant. Conclusion: It is unlikely that suicide rates will decrease in the near future.
Prelingually profoundly deaf schizophrenic patients who hear voices: a phenomenological analysis
Authors: DuFeu M. , McKenna P. J. 
Published: November 2007

Objective: The aims of the study were to examine claims that profoundly deaf schizophrenic patients report auditory hallucinations, and to evaluate proposed explanations that such patients arc really describing other symptoms, or that the phenomenon is restricted to those who had heard and understood language prior to becoming deaf.Method: A total of 17 schizophrenic/schizoaffective patients with onset of profound deafness prior to the age of 2 years underwent structured psychiatric interview.Results: Ten patients (59%) gave accounts of verbal auditory hallucinations with description of content. These did not appear to be attributable to other psychotic experiences and showed typical characteristics of schizophrenic hallucinations. The symptom was present in six patients who had been deaf from birth or early infancy.Conclusion: These findings suggest that auditory hallucinations are a common phenomenon in profoundly prelingually deaf schizophrenic patients, which cannot be accounted for by the above explanations.
Early visual information processing and the Defence Mechanism Test in schizophrenia
Authors: Bogren L. Y. , Bogren I.‐B. H. 
Published: November 2007

Objective: The aim of this study was to determine whether impairment in visual information processing measured by backward masking was related to high threshold values in the Defence Mechanism Test (DMT) in patients with schizophrenia.Method A total of 20 patients with schizophrenia according to DSM‐IV, most of whom were out‐patients, were studied with backward masking and a modified version of the DMT (DMTm).Results: Nine of the patients showed an impairment in backward masking. There was a relationship between impairment in backward masking and the DMTm with either no or a late C‐phase (correct perception in DMTm) in the first series, and a late perception of the peripheral person in the second series. There was no relationship for the other 14 threshold values. The patients did not have high threshold values in the DMTm as was expected. Conclusion: In this sample consisting mainly of out‐patients, there were few relationships between impairment in backward masking and high threshold values in DMTm. Their visual information processing was not as disturbed as expected. Most previous studies on both backward masking and the DMT in patients with schizophrenia have been conducted among in‐patients, who could be expected to be more disturbed than the out‐patients in the present study. The results of studies on in‐patients with schizophrenia must not be generalized to include out‐patients, and vice versa.
The World Health Organization International Consorthm in Psychiatric Epidemiology (ICPE): initial work and future directions ‐ the NAPE Lecture 1998a
Authors: Kessler R. C. 
Published: November 2007

Objective: To provide an overview of the World Health Organization (WHO) International Consortium in Psychiatric Epidemiology (ICPE), to introduce the World Mental Health 2000 (WMH 2000) Initiative and to discuss methodological issues that the ICPE is grappling with in planning the WMH2000 Initiative.Method: We review the history, mission and organization of the ICPE and the rationale behind the WMH2000 Initiative. We review methodological research underlying major design and implementation decisions regarding the WMH2000 surveys.Results: The ICPE is an international consortium created to facilitate cross‐national comparative epidemiological research using the WHO Composite International Diagnostic Interview (CIDI). The first‐phase core TCPE surveys, which we are currently analysing, include over 33 000 interviews in seven countries, with an additional set of over 30000 interviews in seven countries ready to be added to the master file within the next year. The WMH2000 Initiative will include a third series of CIDI surveys that include an anticipated 100000 additional interviews in 10 countries. A series of complex methodological challenges confront us in designing and implementing the WMH2000 surveys. These include issues in the conceptualization and measurement of impairment and disablement, the implementation of standardized quality control procedures across countries, and the blending of epidemiological and clinical interviewing methods to obtain a valid cross‐national characterization of disorder prevalences. Our current plans regarding these issues are discussed.Conclusion: Valid and representative general population epidemiological data on patterns, predictors and adverse consequences of psychiatric disorders are needed as a foundation for public health initiatives. The efforts of the ICPE promise to provide data of this sort for many regions in the world. Formidable methodological and logistical challenges arise in implementing this agenda, but we are confident that these challenges can be met by building on the firm foundation already established in the ongoing ICPE collaboration.