bluuebunny/crossref_metadata_2025 huggingface dataset:
Limits of the Local: Expanding Perspectives on Literacy as a Social Practice
Authors: Brandt Deborah , Clinton Katie
Published: December 2006

This essay reflects on how the social practice model of literacy, an approach that defines reading and writing as situated, social practices, under-theorizes certain aspects of literacy, making it hard to account fully for its workings in local contexts. We trace this theoretical blind spot to the ways that the social practice model was formulated as a challenge to the “Great Divide” or “autonomous” models of literacy. We suggest that in rejecting a conception of literacy as a deterministic force, the revisionists critique veers too far in a reactive direction. By exaggerating the power of local contexts to define the meaning and forms that literacy takes and by under-theorizing the potentials of the technology of literacy, methodological bias and conceptual impasses are created. To open new directions for literacy research we suggest more attention be paid to the material dimensions of literacy. Drawing on the work of Bruno LaTour (1993, 1996), we seek to theorize the transcontextualized and transcontextualizing potentials of literacy = particularly its ability to travel, integrate, and endure. Finally, we propose a set of analytical constructs that treat literacy not solely as an outcome or accomplishment of local practices, but also as a participant in them. By restoring a “thing status” to literacy, we can attend to the role of literacy in human action. The logic of such a perspective suggests that understanding what literacy is doing with people in a setting is as important as understanding what people are doing with literacy in a setting.
“When Can We Make Paper Cranes?”: Examining Pre-Service Teachers' Resistance to Critical Readings of Historical Fiction
Authors: Apol Laura , Sakuma Aki , Reynolds Tracy M. , Rop Sheri K.
Published: December 2006

There has been much recent scholarship on the importance of engaging students of all ages in the critical readings of texts. This study explores a group of pre-service teachers' responses to a set of experiences designed to encourage them to respond critically to several picture book versions of the American-Japanese conflict in World War II, focusing particular attention on Sadako by Eleanor Coerr (1993). Although a presentation by a visiting scholar from Japan highlighted the “constructedness” of the Sadako myth and outlined the historical and cultural inaccuracies of Coerr's telling of the story, the pre-service teachers in the study chose to believe the truth of the story and based their choices about teaching this literature to children on their pre-existing assumptions. The study examines reasons the pre-service teachers may have responded as they did and challenges teacher educators to develop more effective methods to support pre-service teachers as they select literature and develop their own pedagogical strategies to promote thoughtful critical conversations.
Profiling Teaching and Learning Needs in Beginning Literacy Instruction: The Case of Children in “Low Decile” Schools in New Zealand
Authors: McNaughton Stuart , Phillips Gwenneth , MacDonald Shelley
Published: December 2006

Children in low decile schools in New Zealand, most of whom are from Maori and Pacific Islands families achieve significantly lower levels in school reading and writing than other children. Claims have been made about their learning needs. This paper argues that, among other sources of information, decisions about effective teaching should be based on knowledge of children's development under particular instructional conditions. This paper examines the rates and levels of learning particular components of reading and writing over the first year of literacy instruction. A cross sectional design was used to establish profiles from 346 children (5.0-year-olds, n =111; 5.6-year-olds, n = 135; 6.0-year-olds, n =100) in 12 schools in South Auckland, New Zealand. Despite low entry levels in conventional literacy knowledge and receptive and expressive English language skills, children made nationally expected progress in letter and phonological knowledge. Markedly lower than expected progress occurred for word recognition, writing words, and text reading. The profiles indicate that effective literacy instruction needs to enhance the understanding of and production of texts through early and focussed instruction.
Decoding Strategies Used by Chinese Primary School Children
Authors: Pine Nancy , Ping'an Huang , Ren Song Huang
Published: December 2006

This study explored the ways Chinese children remember and decode characters. Thirty primary school children in two cities in China reported how they recognized and remembered individual characters. Of the ten strategy categories identified from the children's responses, three that analyzed character structure dominated. These three categories, as well as several others, emphasized visual processing rather than phonetic processing and suggest emphasis on visual perception. The first-, second-, and third-grade children readily divided characters into structural components and individual strokes. The study concludes that learning written Chinese engaged these children in using semiotic systems unique to their written code and distinct from those usually emphasized in English literacy learning.

Interviewer: Is [the character] right or not?

Child: No.

Interviewer: How do you know that?

Child: Because the end part of it shouldn't be this horizontal bar, but four dots.

First Grade Student, China
“It's a Program That Looks Great on Paper”: The Challenge of America Reads
Authors: Worthy Jo , Prater Kathryn , Pennington Julie
Published: December 2006

This study investigated former President Clinton's America Reads Challenge (1996), a political initiative aimed at improving reading achievement through nonprofessional tutoring. We examined two America Reads programs in light of components that researchers have highlighted as critical for effective tutoring programs. One program reflected Clinton's original proposal, in which he suggested that an “army of volunteer tutors” was the answer to improving children's reading achievement. The other program was tied to a national service organization, Americorps, in keeping with a revised proposal for America Reads (Clinton, 1998). The coordinators and supervisors of the two programs suggested that organizing and implementing a tutoring program using volunteers and work-study students is extremely difficult. Although America Reads provided the salaries of work study tutors, no funds were provided for supervision, materials, or tutor training. The volunteer program dissolved after its first year, while the Americorps program continues on a year-to-year basis, struggling to raise enough money to cover costs that go far beyond the funds provided by America Reads.
Teaching for Literacy Engagement
Authors: Guthrie John T.
Published: December 2006

In our theoretical framework, reading engagement entails multiple perspectives on reading that consist of motivational dispositions, cognitive strategies, conceptual understanding, and social discourse. Possessing these attributes, engaged readers are typically higher achievers than less engaged readers, who show fewer of these qualities or less integration among them. Because engaged readers spend 500% more time reading than disengaged students, educators should attempt to increase engaged reading time by 200%-500%. This may require substantial reconfigurations of curriculum. However, engaged reading is unique because it is both an effective means to achievement (engaged students improve in reading more than disengaged students) and a valued end or educational outcome. A research gap today is the lack of refined, empirical understanding about classroom practices that promote engagement. We designed Concept-Oriented Reading Instruction (CORI) to foster engagement through conceptual themes, hands-on experiences, self-directed learning, interesting texts, classroom discourse, and time for extended reading. For professional development, we attempt to convey the experiences, theory, beliefs, performances, and texts that will enable teachers to implement and generate instruction for engaged reading and learning.
Phonics: A Large Phoneme - Grapheme Frequency Count Revised
Authors: Fry Edward
Published: December 2006

This study is a summary and simplification of a very large phoneme-grapheme frequency count done by Hanna et al. (1966). Although the results and data from the original study have implications for teaching phonics and spelling, they were presented in a complicated and unwieldy manner. Moreover, the original study is out of print. This study, then, presents a succinct and simplified summary of the Hanna et al. results for researchers and teachers of reading and spelling.
Thinking like a Historian: College Students' Reading of Multiple Historical Documents
Authors: Hynd Cynthia , Holschuh Jodi Patrick , Hubbard Betty P.
Published: December 2006

This study examines the thinking of college students who read conflicting accounts of the Tonkin Gulf Incident during the Vietnam Conflict as part of their class assignments, in addition to receiving instruction in disciplinary strategies and the ways in which historians read. Thirteen students responded to questionnaires and participated in two interviews, one before and one after a history unit focusing on the Vietnam Conflict as part of a Learning to Learn class. These interviews were analyzed to discover the changes in students' thinking about history and strategy use. We found that 12 of the 13 students went through epistemological shifts towards viewing historians as constructivists and history texts as arguments rather than truth. We also found that students were more likely to believe, after the unit was completed, that they were capable of and responsible for engaging in the same kind of thinking and strategy employed by historians. Students' learning strategies changed from task completion and memorization to those that elicited critical thinking.
Seeing and Then Seeing Again
Authors: Alvermann Donna E.
Published: December 2006

Old paint on canvas, as it ages, sometimes becomes transparent. When that happens it is possible, in some pictures, to see the original lines: a tree will show through a woman's dress, a child makes way for a dog, a large boat is no longer on an open sea. That is called pentimento because the painter “repented,” changed his mind. Perhaps it would be as well to say that the old conception, replaced by a later choice, is a way of seeing and then seeing again. (Hellman, 1973, p. 3)
The Effective Elementary Classroom Literacy Environment: Examining the Validity of the TEX-IN3 Observation System
Authors: Hoffman James V. , Sailors Misty , Duffy Gerald R. , Beretvas S. Natasha
Published: December 2006

We report on the development and validation of the TEX-IN3, a research tool and protocol designed to assess the quality of the classroom literacy environment. The TEX-IN3 is described in terms of its theoretical base as well as its practical applications. The TEX-IN3 includes three basic components: a text inventory, a text “in-use” observation, and a series of text interviews. The validation of the TEX-IN3 is first reported in terms of its content, development, and focus. Next, a validation study examining the relationship between the TEX-IN3 and student growth in reading comprehension is described. The findings from this study offer support for all three components of the instrument as associated with student achievement growth.
Intervention after Grade 1: Serving Increased Numbers of Struggling Readers Effectively
Authors: Brown Kathleen J. , Morris Darrell , Fields Matthew
Published: December 2006

The present study replicated the original evaluation of the Howard Street tutoring model (Morris, Shaw, & Perney, 1990), an intervention for struggling readers in second and third grade. It also evaluated the effectiveness of supervised paraprofessionals (Title I aides) in delivering that tutorial.

For an entire school year, teachers or paraprofessionals, working under the supervision of a reading specialist, tutored 40 struggling readers twice per week for 45 minutes per session. The tutored group's instruction included guided reading in leveled texts with controlled vocabulary, word study, and reading for fluency. The control group's instruction, which was provided daily in a small-group context, featured guided reading and phonics work in the classroom basal reader. Analysis of covariance was used to compare the performance of the two groups on several end-of-year reading measures. Results showed that, overall, the tutored group outperformed the control group on each of the posttest reading measures (standardized and informal). In addition, the subset of students tutored by paraprofessionals outperformed the control students. In fact, results indicated that in the structured tutoring context, paraprofessional tutors were almost as effective as certified teachers.
The Effects of Comprehensive Vocabulary Instruction on Title I Students' Metacognitive Word-Learning Skills and Reading Comprehension
Authors: Lubliner Shira , Smetana Linda
Published: December 2006

This study examined the effects of a multifaceted, metacognitive vocabulary intervention on the reading comprehension and vocabulary achievement of fifth-grade children in one of California's lowest performing Title I schools. Instruction was comprehensive, designed to facilitate encoding of student-selected words, mastery of clarifying strategies, and executive control of strategies that maximize word-learning proficiency. Strong gains in reading comprehension and vocabulary achievement and increased metacognitive skills were documented following the 12-week vocabulary intervention. Comparisons of Title I students' scores and those of students in an above-average-performing school revealed large, significant differences before the intervention and small, nonsignificant differences following the intervention, suggesting a narrowing of the achievement gap.
Do Children Who Read More Books Know “What is Good Writing” Better than Children Who Read Less? A Comparison between Grade Levels and SES Groups
Authors: Korat Ofra , Schiff Rachel
Published: December 2006

We investigated how SES, grade level, and book reading experiences are related to children's writing self-efficacy as well as to their knowledge of “good writing” and “writing difficulties.” The sample included 199 middle- high (HSES) and low (LSES) SES children (63 second graders, 67 fourth graders, and 69 sixth graders). Gender and SES (low and high) were approximately equally represented. Children were recruited from two elementary schools, one in a low SES neighborhood and the other in a middle-high SES neighborhood. Writing knowledge was elicited by two open-ended questions and self-efficacy by a 10-item questionnaire. Children's book reading experiences were measured using the Title Recognition Test (TRT). Results showed that, across both SES groups, children's grade level was the most important predictor of their knowledge of “good writing” and “writing difficulties” and also of their writing self-efficacy, followed by the children's book reading experiences. HSES school children gained more writing knowledge as a function of grade level than did the LSES school children. An important and surprising finding was that children's knowledge of “good writing” and “writing difficulties” was explained by their book reading experiences only in the LSES group and not in the HSES group. The implications of these findings for theory and practice are discussed.
Novel Mutations in the Parathyroid Hormone (PTH)/PTH-Related Peptide Receptor Type 1 Causing Blomstrand Osteochondrodysplasia Types I and II
Authors: Hoogendam J. , Farih-Sips H. , Wÿnaendts L. C. , Löwik C. W. G. M. , Wit J. M. , Karperien M.
Published: December 2006

Context: The PTH/PTHrP receptor type 1 (PTHR1) has a key role in endochondral ossification, which is emphasized by diseases resulting from mutations in the PTHR1 gene. Among these diseases is Blomstrand osteochondrodysplasia (BOCD).

Objective: BOCD can be divided into two types, depending on the severity of the skeletal abnormalities. The molecular basis for this heterogenic presentation is unknown.

Design and Patients: We performed mutation analysis in two families with type I and in three families with the less severe form of BOCD type II.

Results: In one of the type I BOCD cases, a homozygous nonsense mutation (R104X) was found, resulting in a truncated PTHR1. In the second type I BOCD case, no mutation was found. A homozygous nucleotide change (intron M4+27C>T) was demonstrated in one of the type II BOCD cases creating a novel splice site. In dermal fibroblasts of the patient, this novel splice site was preferentially used, resulting in an aberrant transcript. The wild-type transcript remained, however, present, albeit at low levels. In the other two families with type II BOCD, a previously identified homozygous missense mutation (P132L) was found. Functional analysis demonstrated that the P132L mutant had low residual activity.

Conclusions: In combination with data presented in literature, we conclude that type I BOCD is caused by a complete inactivation of the PTHR1, whereas low levels of residual activity due to a near complete inactivation of the PTHR1 result in the relatively milder presentation of type II BOCD.
A broad spectrum of actin paralogs inParamecium tetraureliacells display differential localization and function
Authors: Sehring Ivonne M. , Reiner Christoph , Mansfeld Jörg , Plattner Helmut , Kissmehl Roland
Published: December 2006

To localize the different actin paralogs found in Paramecium and to disclose functional implications, we used overexpression of GFP-fusion proteins and antibody labeling, as well as gene silencing. Several isoforms are associated with food vacuoles of different stages. GFP-actin either forms a tail at the lee side of the organelle, or it is vesicle bound in a homogenous or in a speckled arrangement, thus reflecting an actin-based mosaic of the phagosome surface appropriate for association and/or dissociation of other vesicles upon travel through the cell. Several paralogs occur in cilia. A set of actins is found in the cell cortex where actin outlines the regular surface pattern. Labeling of defined structures of the oral cavity is due to other types of actin, whereas yet more types are distributed in a pattern suggesting association with the numerous Golgi fields. A substantial fraction of actins is associated with cytoskeletal elements that are known to be composed of other proteins. Silencing of the respective actin genes or gene subfamilies entails inhibitory effects on organelles compatible with localization studies. Knock down of the actin found in the cleavage furrow abolishes cell division, whereas silencing of other actin genes alters vitality, cell shape and swimming behavior.
A new method for collecting vehicle behaviour in daily use for energy and environmental analysis
Authors: Alessandrini A , Filippi F , Orecchini F , Ortenzi F
Published: December 2006

The power supply, fuel consumption, and noxious emissions of a vehicle depend on the use that is made of it. Usually [1] only the driving cycle is considered to be a sufficient way to gauge a vehicle's usage. It is not, however, enough. Experimental tests have proved that, while similar driving cycles entail similar power demand, fuel consumption and emissions differ. In addition, a driving cycle, usually a synthesis [1-7] of several cycles collected experimentally, represents neither a specific link of the road network nor a specific user. Vehicle use must, accordingly, be described by something more comprehensive than the driving cycle, and this might be called the ‘use cycle’, for which a definition needed to be found. For a definition of the use cycle, all possible factors influencing vehicle emissions had to be examined. It was thus necessary to develop a tool both for gathering data that might reveal a different use of the vehicle and for identifying factors that might have an influence on emissions. The easiest, cheapest, and most versatile way to collect real data on the use of a vehicle is to use the vehicle's own sensors connected to the on-board diagnostic (OBD-2) port. Readings from a GPS can provide some characteristics related to the vehicle's position. This paper describes the development of a tool for collecting real-time OBD and GPS information. The acquisition tool was validated by a number of tests on a dynamometer chassis and differences are never higher than 3 per cent (e.g. on speed max 2 km/h). The first result obtained on vehicle usage is that driver behaviour influences throttle position independently of the driving cycle. Even with similar driving cycles, the accelerator pedal position and its variations turned out to be heavily different, suggesting a new definition of driver behaviour linked to the way the driver uses the pedals. Such pedal movement does have an influence on the air-fuel ratio, which remains stable around the stoichiometric value with ‘calm’ use of the accelerator, while it changes continuously, never becoming stoichiometric, with ‘aggressive’ accelerator behaviour. The continuous use of the developed tool on large fleets of vehicles will allow progress along this path and help define use cycles that may then be used by car manufacturers to design vehicles more efficient in their different uses and by the authorities to force more stringent homologation rules.
Study on vehicle chassis control integration based on a main-loop-inner-loop design approach
Authors: Shen Xiaoming , Yu Fan
Published: December 2006

In this paper, vehicle chassis control integration has been investigated on the basis of a separated main-loop control and an optimal force distribution inner-loop design structure, as the tyre is conceptually treated as a special kind of actuator. In order to study the characteristics of the particular subsystems, i.e. longitudinal slip control of the tyres and active wheel steering during control integration, as well as the effects on vehicle-handling performance when the above two subsystems are integrated, a standard H∞ control technique is used for the main-loop design, which focuses on vehicle motion control only and a linear quadratic minimization approach is applied for achieving the optimal distribution of vehicle motion forces and moments between the wheels. Furthermore, the rotational dynamics of the wheels are considered when the resultant slip ratio control is being transformed to the actual wheel control torque that can be handled by braking and engine management systems. Simulation results and analysis indicate that both the above two subsystems have indispensable roles in the framework of integration; meanwhile a remarkable improvement in the handling performance and a large stability margin can be expected from chassis control integration and the above control structure.
Use of a small low-noise wind tunnel for determining the aeroacoustic noise produced by components on a vehicle
Authors: Kingan M J , Pearse J R , Hubbard P D
Published: December 2006

This paper describes an experimental method used to determine the aeroacoustic noise produced by a ‘roof rack’ placed on the roof of a vehicle. Testing was done on a vehicle roof positioned at the outlet jet of a small low-noise wind tunnel. A ‘simulated vehicle cabin’ was constructed beneath the vehicle roof that had similar absorption characteristics to an actual vehicle cabin. Sound pressure level measurements were made within the simulated vehicle cabin. The sound pressure level measurements were consistent with measurements made within the cabin of an actual vehicle in a large anechoic wind tunnel. The method could also be used to determine the in-cabin aeroacoustic noise produced by other vehicle accessories.
Development of a new methodology for vehicle steering system inspection
Authors: Muñoz B , Ramírez M , Díaz V
Published: December 2006

A vehicles steering system, which plays a fundamental role in road safety, is nowadays one of the items that are checked during the Periodic Motor Vehicle Inspection (PMVI) in all developed countries, such as the European Union or the United States of America. This kind of inspection is usually done by means of a device called a sideslip tester, along with an operator's visual inspection. Nevertheless, this method shows some serious problems, and clearly seems to need improvement. It does not take into account important parameters such as the steering geometry or vehicle weight and, moreover, it does not provide a clear rejection criteria for inspectors.

The main aim of this research is to set up a new inspection methodology for a vehicle steering system in a PMVI, taking all variables that are now ignored into account, in order to avoid dangerous situations during driving and to provide the inspectors with clear and objective rejection criteria. This paper presents the implementation and design issues related to the development of the new device. Also, some experimental data will be shown in order to validate the developed procedure.
Regenerative braking algorithm for a hybrid electric vehicle with CVT ratio control
Authors: Yeo Hoon , Hwang Sungho , Kim Hyunsoo
Published: December 2006

A regenerative braking algorithm is proposed for a hybrid electric vehicle with a continuously variable transmission (CVT) to make the maximum use of the regenerative braking energy. In the regenerative braking algorithm, the regenerative torque is determined by considering the motor capacity, battery state of charge (SOC), and vehicle velocity. The regenerative braking force is calculated from the brake control unit by comparing the demanded brake torque and the motor torque available. The wheel pressure is reduced by the amount of the regenerative braking force and is supplied from the hydraulic brake module. In addition, the CVT speed ratio control algorithm is suggested during braking for optimal motor operation. The optimal operation line is proposed to operate the motor in the most efficient region while keeping the motor speed as low as possible by considering engine noise and friction. It is found from the experiments that the regenerative braking algorithm with CVT ratio control offers an improved battery SOC, which provides increased recuperation energy by 8 per cent for the federal urban driving schedule compared with that of the conventional CVT ratio control.
Iterative identification of stiffness parameters in a car suspension elastokinematic model
Authors: Meissonnier J , Metz P , Fauroux J-C , Gogu G , Montezin C
Published: December 2006

A new method for identifying the bushing stiffness parameters in car suspension mechanisms is presented. This method is based on the observation of part motions in a suspension on a kinematic and compliance test bench. This observation is used to compute bushing deflections for various load cases applied on the suspension. An iterative identification method has been set up and interfaced with commercial multi-body simulation software (ADAMS) in order to find a set of stiffness parameters that achieve the correlation between model and reality. This identification method is tested on a pseudo-McPherson suspension and on a complex multilink rear suspension. In each case, the behaviour of the identified model converges towards the reference behaviour.
Zero-dimensional modelling of a producer gas-based reciprocating engine
Authors: Sridhar G , Paul P. J. , Mukunda H. S.
Published: December 2006

A zero-dimensional modelling study has been conducted using wrinkled flame theory for flame propagation to understand the in-cylinder pressure behaviour with time in a reciprocating internal combustion engine. These are compared with experiments conducted on the engine operated on biomass derived from producer gas and air mixture. The required inputs on the laminar burning velocity and turbulence parameters are obtained from separate studies. The data related to laminar burning velocity for producer gas and air mixture at thermodynamic conditions typical of unburned mixture in an engine cylinder were obtained from one-dimensional flame calculations. The turbulence parameters were obtained by conducting a three-dimensional computational fluid dynamics study on a bowl-in-piston geometry to simulate motored or non-firing conditions. The above mentioned data were used in the zero-dimensional model to make pressure-time (p-θ) computation over the complete engine cycle, for a range of test cases at varying compression ratio (CR) and ignition timing. The computational results matched reasonably well with experimental p-θ curves at advanced ignition timing at all CRs. The error in computed indicated power (IP) at advanced ignition setting (18°-27° CA) is around 3–4 per cent for CR = 17.0 and 11.5, and between 6 and 9 per cent for CR = 13.5. However, at less advanced ignition setting, the error in computed IP is larger and this is attributed to enhanced fluid dynamic effect due to reverse squish effect. And, whenever major part of the combustion occurred during this period, the deviation in the computed result appeared to be larger. This model has also been used to predict output of a commercially available producer gas engine of 60 kW. The optimum ignition timing on this particular engine was experimentally found to be 22°-24° before top centre. The zero-dimensional model has been used in a predictive mode and results compared with brake power under wide throttle open condition.
A time-domain model of axial wave propagation in liquid-filled flexible hoses
Authors: Johnston D. N.
Published: December 2006

The dynamic behaviour of liquid in a flexible hose is difficult to model because of complex interactions between the liquid and the hose wall. This results in two sets of coupled axial waves in the liquid and in the wall, travelling at two different wavespeeds. A method for time-domain modelling is described which represents wave propagation at the two different wavespeeds, including viscoelastic damping. Good agreement between the model and measurement is obtained. Simple corrections are included for low-frequency and static effects, including viscoelastic relaxation and non-linearities.
Experimental and Computational Study on the Thermochemistry of Bromoanilines
Authors: Ribeiro da Silva Manuel A V , Ferreira Ana I M C L , Gomes José R B
Published: December 2006

The standard (p° = 0.1 MPa) molar enthalpies of formation of 2-, 3-, and 4-bromoaniline, 2,4-, 2,5-, and 2,6-dibromoaniline, and 2,4,6-tribromoaniline were derived from the standard molar enthalpies of combustion, in oxygen, which yields CO2(g), N2(g), and HBr·600H2O(l), at T = 298.15 K, measured by using rotating-bomb calorimetry. The standard molar enthalpies of sublimation, or vaporization, of these compounds at T = 298.15 K were measured by using Calvet microcalorimetry, and so their standard molar enthalpies of formation in the gaseous state were derived. The enthalpies of fusion of the solid compounds were determined by DSC. The gas-phase enthalpies of formation were also estimated by density functional theory calculations performed at the BP86/6-31+G* level. As a result it is confirmed that thermodynamic data is consistent with intramolecular N–H···Br hydrogen bonding.
Millimeter-Wave Rotational Spectrum of CF3CCD in the Ground and Excited Vibrational States v10 = 1
Authors: Motamedi Masoud , Haseli Aliakbar
Published: December 2006

Millimeter-wave rotational spectra of the symmetric top molecule CF3CCD have been measured in its ground and excited vibrational states, v10 = 1. Analysis of the ground-state spectra gave the following rotational parameters: B0 = 2696.06753 MHz, DJ = 0.22759 kHz, DJk = 6.1748 kHz. HJk (16.1 mHz) and HkJ (−0.243 mHz) were determined for the first time. In the v10 = 1 state, l = ±1 series have been assigned and spectroscopic parameters were obtained accurately: B1 = 2701.26211 MHz, qt+(2,2) = 3.30887 MHz, Aζ = 3263.93 MHz. The off diagonal parameter rt (0.152 MHz) was determined for the first time.
Preparations, Structures, and Properties of Sulfato-Bridged Dinuclear and Tetranuclear Vanadium(III) Complexes with a Dinucleating Ligand, 2-Oxo-N,N′-bis(2-pyridylmethyl)-1,3-propanediamine-N,N′-diacetate
Authors: Kanamori Kan , Matsui Naoto , Takagi Kentaro , Miyashita Yoshitaro , Okamoto Ken-ichi
Published: December 2006

New dinuclear and tetranuclear vanadium(III) complexes with sulfato bridge(s), [{VIII(H2O)}2(μ-hpnbpda)(μ-OH)(μ-SO4)]·5.25H2O (1) and [VIII4(μ-hpnbpda)2(μ-OH)2(μ-SO4)2]·12H2O (2), where hpnbpda is an alkoxo-bridging dinucleating ligand, 2-oxo-N,N′-bis(2-pyridylmethyl)-1,3-propanediamine-N,N′-diacetate, were prepared, and their structures were determined by X-ray crystallography. The vanadium(III) center in 1 adopts heptacoordinate structure while that in 2 has a hexacoordinate structure. In 2, the two dinuclear vanadium(III) units bridged by the alkoxo group of hpnbpda are further linked by two hydroxo and two sulfato bridging groups, resulting in a dimer-of-dimers structure. Measurement of the temperature dependence of the magnetic susceptibility of 1 revealed that the two vanadium(III) ions are antiferromagnetically coupled with J = −5.9 cm−1 and g = 1.90.
Sulfur-Bonded 2-Methylthiopyridine (2-MeSpy) Complex of Iridium(III). Crystal Structure of [Cp*IrI2(2-MeSpy-κS)] (Cp* = η5-C5Me5)
Authors: Sekioka Yusuke , Suzuki Takayoshi
Published: December 2006

A reaction of [Cp*Ir(2-Spy)(N3)] (Cp* = pentamethylcyclopentadienyl; 2-Spy = 2-pyridinethiolate) with two equivalents of methyl iodide afforded the diiodo complex bearing 2-MeSpy, [Cp*IrI2(2-MeSpy)] (3). From X-ray crystallography and IR spectroscopy, the S atom of 2-MeSpy is coordinated to the metal ion in the solid state. In CD2Cl2, complex 3 exhibited a dissociation equilibrium of 2-MeSpy similar to the corresponding thioanisole complex of [Cp*IrI2(MeSPh)].
Synthesis and Oxidative Ring Contraction of 1,5,3,7-Dichalcogenadiazocanes. Novel Formation of 1,2,4-Diselenazolidines, 1,2,4-Ditellurazolidines, and 1,2,3,4,5,7-Pentathiazocanes
Authors: Takikawa Yuji , Koyama Yutaka , Yoshida Takamasa , Makino Kenshiro , Shibuya Hiroki , Sato Kazuto , Otsuka Tatsuya , Shibata Yuko , Onuma Yuki , Aoyagi Shigenobu , Shimada Kazuaki , Kabuto Chizuko
Published: December 2006

1,5,3,7-Dithiadiazocanes, 1,5,3,7-diselenadiazocanes, and 1,5,3,7-ditelluradiazocanes were prepared from a primary amine, formalin, and H2S, NaSeH, or NaTeH, respectively. Oxidation of 1,5,3,7-diselenadiazocanes and 1,5,3,7-ditelluradiazocanes using NBS efficiently afforded 1,2,4-diselenazolidines or 1,2,4-ditellurazolidines, respectively. In contrast, treatment of 1,5,3,7-dithiadiazocanes with bromine-elemental sulfur or disulfur dichloride (S2Cl2) afforded 1,2,3,4,5,7-pentathiazocanes. An unusual oxidative conversion of 1,5,3,7-dichalcogenadiazocanes into these products was assumed to proceed through in situ formation of 1,5,3,7-dichalcogenadiazabicyclo[3.3.0]octane-type dications.
Functionalized Calix[4]resorcinarene Cavitands. Versatile Platforms for the Modular Construction of Extended Molecular Switches
Authors: Azov Vladimir A , Schlegel Anna , Diederich François
Published: December 2006

We report the synthesis and investigation of the vase–kite conformational switching of bridged calix[4]resorcinarene-based cavitands bearing iodo or ethynyl substituents on the upper rim of the cavity. These reactive centers make the cavitands versatile platforms for further modular extension by means of Sonogashira cross-couplings, thereby enabling the construction of diverse functional architectures that are switchable between two highly restricted conformations and that undergo geometrically defined expansions/contractions on the multi-nanometer scale. This is illustrated by attachment of oligo(phenyleneethynyl) fragments, bearing terminal donor and acceptor BODIPY (dipyrrometheneboron difluoride) dyes, to a diiodo-substituted cavitand. The multi-nanometer-sized switching motion between the expanded kite and the contracted vase states, induced by temperature or pH changes, was proven by 1H NMR spectroscopy and FRET (fluorescence resonance energy transfer) measurements. The cavitand system, with its modular construction scheme, holds promise to become a general tool for controlled on/off switching of excimer and exciplex formation, PET (photoinduced electron-transfer), or other processes and for investigating the distance dependence of the underlying intermolecular interactions.
Fabrication and Photocatalytic Activity of Fullerodendron/CaCO3 Composites
Authors: Talukdar Bandana , Takaguchi Yutaka , Yanagimoto Yasushi , Tsuboi Sadao , Ichihara Masahiro , Ohta Kazuchika
Published: December 2006

Novel composite materials consisting of fullerodendrons and CaCO3 particles were fabricated to have better efficiency as photosensitizers in singlet photooxygenation reactions compared to pristine fullerodendrons. Moreover, fullerodendrons in composites demonstrate the ability to control CaCO3 polymorphism through formation of thermodynamically least stable form of CaCO3: vaterite.
A Theory of Volatility Spreads
Authors: Bakshi Gurdip , Madan Dilip
Published: December 2006

This study formalizes the departure between risk-neutral and physical index return volatilities, termed volatility spreads. Theoretically, the departure between risk-neutral and physical index volatility is connected to the higher-order physical return moments and the parameters of the pricing kernel process. This theory predicts positive volatility spreads when investors are risk averse, and when the physical index distribution is negatively skewed and leptokurtic. Our empirical evidence is supportive of the theoretical implications of risk aversion, exposure to tail events, and fatter left-tails of the physical index distribution in markets where volatility is traded.
Information System Success: Individual and Organizational Determinants
Authors: Sabherwal Rajiv , Jeyaraj Anand , Chowa Charles
Published: December 2006

Despite considerable empirical research, results on the relationships among constructs related to information system (IS) success, as well as the determinants of IS success, are often inconsistent. A comprehensive understanding of IS success thus remains elusive. In an attempt to address this situation, which may partly be due to the exclusion of potentially important constructs from prior parsimonious models of IS success, we present and test a comprehensive theoretical model. This model explains interrelationships among four constructs representing the success of a specific IS (user satisfaction, system use, perceived usefulness, and system quality), and the relationships of these IS success constructs with four user-related constructs (user experience with ISs, user training in ISs, user attitude toward ISs, and user participation in the development of the specific IS) and two constructs representing the context (top-management support for ISs and facilitating conditions for ISs). To test the model, we first used meta-analysis to compute a correlation matrix for the constructs in the model based on 612 findings from 121 studies published between 1980 and 2004, and then used this correlation matrix as input for a LISREL analysis of the model. Overall, we found excellent support for the theoretical model. The results underline the importance of user-related and contextual attributes in IS success and raise questions about some commonly believed relationships.
Clay-Sized Minerals in Permafrost-Affected Soils (Cryosols) From King George Island, Antarctica
Authors: Simas Felipe N. B. , Schaefer Carlos Ernesto G. R. , Melo Vander F. , Guerra Marcelo B. B. , Saunders Martin , Gilkes Robert J.
Published: December 2006

Cryosols from Maritime Antarctica have been less studied than soils from continental areas of Antarctica. In this work X-ray diffraction, difference X-ray diffraction, differential thermal analysis, thermogravimetry, transmission electron microscopy/energy dispersive spectroscopy and selective chemical dissolution were used to characterize the clay fraction of basaltic, acid sulfate and ornithogenic Cryosols from ice-free areas of Admiralty Bay, King George Island. Non-crystalline phases are important soil components and reach >75% of the clay fraction for some ornithogenic soils. Randomly interstratified smectite-hydroxy-Al-interlayered smectite is the main clay mineral of basaltic soils. Kaolinite, chlorite and regularly interstratified illite-smectite predominate in acid sulfate soils. Jarosite is also an important component of the clay fraction in these soils. Crystalline Al and Fe phosphates occur in the clay at sites directly affected by penguin activity and the chemical characteristics of these ornithogenic sites are controlled by highly reactive, non-crystalline Al, Si, Fe and P phases. Chemical weathering is an active process in Cryosols in Maritime Antarctica and is enhanced by the presence of sulfides for some parent materials, and faunal activity.
Some Successful Approaches to Quantitative Mineral Analysis as Revealed by the 3rd Reynolds Cup Contest
Authors: Omotoso Oladipo , McCarty Douglas K. , Hillier Stephen , Kleeberg Reinhard
Published: December 2006

Details of the quantitative techniques successfully applied to artificial rock mixtures distributed for the third Clay Minerals Society Reynolds Cup (RC) contest are presented. Participants each received three samples, two containing 17 minerals each and a third containing ten minerals. The true composition of the samples was unknown to all participants during the contest period. The results submitted were ranked by summing the deviations from the actual compositions (bias). The top three finishers used mainly X-ray diffraction (XRD) for identification and quantification. The winner obtained an average bias of 11.3% per sample by using an internal standard and modified single-line reference intensity ratio (RIR) method based on pure mineral standards. Full-pattern fitting by genetic algorithm was used to measure the integrated intensity of the diagnostic single-line reflections chosen for quantification. Elemental-composition optimization was used separately to constrain phase concentrations that were uncertain because the reference mineral standards were lacking or not ideal. Cation exchange capacity, oriented-sample XRD analysis, and thermogravimetric analysis were also used as supplementary techniques. The second-place finisher obtained an average bias of 13.9%, also by using an RIR method, but without an added internal standard and with intensity measured by whole-pattern fitting. The third-place finisher, who obtained an average bias of 15.3%, used the Rietveld method for quantification and identification of minor phases (using difference plots). This participant also used scanning electron microscopy (with X-ray microanalysis) to identify minor components and verify the composition of structures used in Rietveld analysis. As in the previous contests, successful quantification appears to be more dependent on analyst experience than on the analytical technique or software used.
Tissue Distribution of Ca2+-dependent Activator Protein for Secretion Family Members CAPS1 and CAPS2 in Mice
Authors: Sadakata Tetsushi , Washida Miwa , Morita Noriyuki , Furuichi Teiichi
Published: December 2006

The family of Ca2+-dependent activator proteins for secretion (CAPS) is involved in dense-core vesicle exocytosis. CAPS1/CADPS1 and CAPS2/CADPS2 have been identified in mammals. CAPS1 regulates catecholamine release from neuroendocrine cells, whereas CAPS2 is involved in the release of brain-derived neurotrophic factor and neurotrophin-3 from cerebellar granule cells. CAPS1 and CAPS2 are predominantly expressed in brain. Here we show the immunohistochemical localization of the CAPS family proteins in various mouse tissues. In the pituitary gland, CAPS1 and CAPS2 were localized to the pars nervosa and the pars intermedia, respectively. In non-neural tissues, CAPS1 was observed in the islets of Langerhans, minor cell types of the spleen and stomach, and medullary cells of the adrenal gland, whereas CAPS2 was present in bronchial epithelial cells, thyroid parafollicular cells, chief cells of the stomach, ductal epithelium of the salivary gland, kidney proximal tubules, and minor cell types of the thymus, spleen, and colon. These results suggest that secretion from distinct cell types in various tissues involves either or both members of the CAPS family.
Mast Cell-specific Gangliosides and Fc∊RI Follow the Same Endocytic Pathway From Lipid Rafts in RBL-2H3 Cells
Authors: Oliver Constance , Fujimura Akira , e Souza Adriana Maria Mariano Silveira , de Castro Rodrigo Orlandini , Siraganian Reuben P. , Jamur Maria Celia
Published: December 2006

Recent studies have shown that, in mast cells, membrane microdomains rich in cholesterol and glycosphingolipids called lipid rafts play an important role in Fc∊RI signaling. The present study demonstrates that, in RBL-2H3 cells following stimulation, the mast cell-specific gangliosides associated with Fc∊RI are internalized from lipid rafts along with the receptor. When the cells are labeled with iodinated antibodies against the gangliosides or against Fc∊RI and the cell components are then fractionated on Percoll density gradients, in stimulated cells the gangliosides are internalized with the same kinetics as Fc∊RI and at 3 hr are present in the dense lysosome fraction. Using transmission electron microscopy, with antibody against the gangliosides conjugated to horseradish peroxidase and antibody against Fc∊RI conjugated to colloidal gold, it was possible to demonstrate that the gangliosides and Fc∊RI are internalized in the same coated vesicles. At 5 min, the gangliosides and Fc∊RI can be identified in early endosomes and at 3 hr are found together in acid phosphatase-positive lysosomes. This study demonstrates that the mast cell-specific gangliosides are internalized from lipid rafts in the same vesicles and traffic intracellularly with the same kinetics as Fc∊RI. This study contains online supplemental material at http://www.jhc.org . Please visit this article online to view these materials.
Activation of the IGF1 System Characterizes Cholangiocyte Survival During Progression of Primary Biliary Cirrhosis
Authors: Onori Paolo , Alvaro Domenico , Floreani AnnaRosa , Mancino MariaGrazia , Franchitto Antonio , Guido Maria , Carpino Guido , Santis Adriano De , Angelico Mario , Attili Adolfo F. , Gaudio Eugenio
Published: December 2006

We evaluated the IGF1 system in cholangiocytes of primay biliary cirrhosis (PBC) patients and investigated the relationships with apoptosis. Biopsies of PBC patients ( n=32) and normal subjects ( n=5) were investigated by immunohistochemistry for expression in cholangiocytes of IGF1, IGF1-R, pAKT, terminal deoxynucleotide transferase end labeling (TUNEL), Bax (proapoptotic protein), and Bcl2 (antiapoptotic protein). Whereas normal cholangiocytes were almost negative, cholangiocytes of PBC patients showed strong IHC staining for IGF1, IGF1-R, and pAKT, which increases from stage I to stage IV, where >70% of cholangiocytes were positive. Bax/Bcl2 ratio reached the highest value (4.6) in PBC stage III when apoptosis is maximal (24% TUNEL positivity), whereas it declines in stage IV (1.4) when only 7.8% cholangiocytes were TUNEL positive. In PBC stages III and IV, expression of IGF1, IGF1-R, and pAKT in cholangiocytes was directly correlated with the antiapoptotic Bcl2 and inversely correlated with proapoptotic Bax, Bax/Bcl2 ratio, and TUNEL positivity. In conclusion, cholangiocytes of PBC patients showed a marked increase in IGF1, IGF1-R, and pAKT expression involving most cholangiocytes surviving in the terminal ductopenic stage. This was associated and correlated with a balance of pro- and antiapoptotic proteins favoring survival rather than apoptosis, suggesting a major role of IGF1 system in promoting cholangiocyte survival.