bluuebunny/crossref_metadata_2025 huggingface dataset:
Energieversorgung von energieautarken Sensoren (Autonomous Energy Supply for Wireless Sensors)
Authors: Hahn Robert
Published: September 2007

Für die Energieversorgung autarker Sensoren und Messsysteme werden in Zukunft Mikrobrennstoffzellen an Bedeutung gewinnen, die durch einen ausreichend großen Speichervorrat einen wartungsfreien Langzeitbetrieb gewährleisten. Mit der am Fraunhofer IZM entwickelten PEM-Mikrobrennstoffzellentechnologie wird das bereits bei sehr kleinen Systemen möglich sein. Dieser Artikel geht insbesondere auf die bedarfsgerechte Erzeugung von Wasserstoff im Mikrosystem ein. Für Systeme, die ihren Energiebedarf aus dem Tageslicht mittels Solarmodulen decken können, wurde eine miniaturisierte Modultechnologie entwickelt, die es erlaubt, hocheffiziente Solarzellen zu Modulen von nur wenigen Quadratzentimeter Fläche zu verschalten. Als Zwischenspeicher für die aus der Umwelt gewonnenen Energie sind vor allem Li-Polymer-Batterien geeignet. Mithilfe der Wafer-Level-Battery-Technologie können diese Batterien direkt auf dem Substrat oder Wafer mit minimalem Volumenbedarf integriert werden.
Markierungsfreie DNA-Detektion mit Silizium-Feldeffekt-Sensoren – Messeffekte oder Artefakte? (Label-free DNA Detection with Silicon Field-Effect Sensors – Real Effects or Artefacts?)
Authors: Schöning Michael J. , Abouzar Maryam H. , Poghossian Arshak , Han Yinhua , Offenhäusser Andreas , Ingebrandt Sven
Published: September 2007

Die Entwicklung von diagnostischen Methoden auf der Basis von DNA-Mikroarrays, bekannt als DNA- oder Gen-Chips, wird in Zukunft in vielen Bereichen neue Möglichkeiten eröffnen. Zurzeit basieren die meisten DNA-Chips auf Fluoreszenzmarkierung oder radioaktiver Markierung der zu analysierenden DNA in Verbindung mit entsprechenden Nachweismethoden für die jeweiligen Marker. In diesem Artikel stellen wir eine markerfreie und voll-elektronische Messmethode vor, die auf der Detektion der DNA mittels Feldeffekt-Sensoren beruht.
Dealing With Troubled Writers: A Literacy Teacher's Dilemma
Authors: Simmons John
Published: September 2007

A movement in late 20th‐century rhetorical theory asked teachers to encourage writing on personal topics as well as formal, impersonal ones. Thus, to traditional writing goals (pleasing, persuading, and instructing) the exorcism of often deep emotions was added.

This movement forced teachers to read and evaluate student writing in a more involved, intimate, and sympathetic manner. An almost inevitable result is the demand for teachers to witness writing that expresses anger, rebellion, the desire for retribution, and so on. Given the legal and professional limits on what teachers can do in dealing with such writing, the dilemma they face is the disturbing consequence. The author offers practical suggestions for teachers who see distressing and sometimes alarming patterns in a student's writing.
Real Writers as Aware Readers: Writing Creatively as a Means to Develop Reading Skills
Authors: Glenn Wendy J.
Published: September 2007

Increased attention on written response to literature has tended to eliminate other forms of student writing in literature classrooms. However, when we allow students to write fiction unrelated to a particular text, their commitment to and understanding of texts are enhanced. This can serve as a means of engaging students with reading.

Eight preservice teachers volunteered to participate in a writing workshop, meeting to share their fiction and provide written and oral feedback to others in the group. Each week, participants drafted reflections about the works read for class in relation to their own work as authors. These were analyzed using the constant comparative method. Two case studies provide representative examples of how participants demonstrated behaviors associated with good readers as a direct result of their commitment to their writing. They were motivated to improve their stories, and this motivation translated into their use of effective reading strategies.
The Leisure Reading Habits of Urban Adolescents
Authors: Hughes‐Hassell Sandra , Rodge Pradnya
Published: September 2007

Research indicates that there is a strong relationship between leisure reading and school achievement, but the leisure reading habits of urban adolescents have rarely been studied. From their investigation of the leisure reading habits of 584 urban minority middle school students, the authors identify these key findings:

More than two‐thirds of the students indicated that they read for fun and relaxation, to learn new things, or because they were bored.

Magazines were the preferred reading material for both males and females, followed by comics and the Internet.

Celebrities, “people or characters like me,” sports figures, and musicians were among the most popular subjects pursued in respondents' leisure reading.

Reading during summer vacation was not popular with either sex.

Based on these findings, the authors provide eight recommendations for teachers and librarians to keep in mind as they strive to support the literacy development of urban adolescents.
Constructing Anne Frank: Critical Literacy and the Holocaust in Eighth‐Grade English
Authors: Spector Karen , Jones Stephanie
Published: September 2007

Using the assumption that texts actively work to position readers and readers actively work to position texts, the authors argue that moral lessons emerge from the interactions between texts, readers, and the ideological narratives that inspire both.

After differentiating versions of Anne Frank's diary and explicating motives behind their construction, we explore ways that students' perspectives of Anne Frank impede robust understandings of the Holocaust, including enabling readers to preserve assumptions about Anne Frank as only optimistic and triumphant. Through critical literacy practices, the authors demonstrate how narrow perspectives of texts and readers can be interrupted through questioning about readers, authors, texts, and different versions of Anne Frank's diary. Teaching tips are provided, and the article concludes by discussing the importance of equipping students with critical literacy tools for reading the Holocaust in particular and for reading all texts more generally.
Portals Into Poetry: Using Generative Writing Groups to Facilitate Student Engagement With Word Art
Authors: Young Linda
Published: September 2007

The Poetry Generating Loop is a new kind of generative writing circle that offers concrete, creative ways to get students involved in and excited about poetry. By writing poems in groups, students are able to learn poetic terms and experiment with techniques through their writing—a process that can shed new light on the world of poetry.
Guy Debord's The Society of the Spectacle
Authors: Trier James
Published: September 2007

This column discusses the 40th anniversary of Guy Debord's The Society of the Spectacle and the Situationist International group. The author juxtaposes a few brief historical snapshots with definitions of key terms and paraphrases some important ideas and events. The author also refers to selected texts and Internet sources by and about Debord and the situationists. Readers who subsequently engage with these texts and Internet sources should be able to discover the relevance of Debord and the SI to current discourses of critical media literacy.
Responding When Students Don't Get It
Authors: Fisher Douglas , Frey Nancy , Lapp Diane
Published: September 2007

When students make mistakes, have misconceptions, or are simply wrong, how their teachers respond either builds new skills and understanding or reinforces errors. An intentional approach to responding when students don't get it includes questions to check for understanding, prompts for cognitive and metacognitive work, cues to divert attention, and direct explanations.
Shape effects on the capacity of rectangular footings under general loading
Authors: Gourvenec S.
Published: September 2007

Ultimate limit states under vertical (V), moment (M) and horizontal (H) loading of rectangular footings with varying breadth-to-length aspect ratios (B/L) are compared with predictions for plane-strain conditions. Footing/soil interfaces unable to sustain tension and with unlimited tensile resistance are considered. Finite element and analytical predictions are reported, and results are presented as failure envelopes in VH, VM and VMH load space. Vertical and moment capacity of rectangular footings, with either zero or unlimited tension interfaces, is shown to increase with reducing footing length, for foundations of a given bearing area. For footings unable to sustain tension, footing aspect ratio does not affect the shape of the failure envelope: therefore ultimate limit states of a footing of any aspect ratio can be derived from a unique envelope scaled by the appropriate ultimate limit loads defining its apex points. A closed-form expression is proposed to describe the shape of the normalised VMH envelope. The shape of failure envelopes for footings able to sustain tension is dependent on footing geometry.
Monitoring and analysis of the bending behaviour of discrete piles used to stabilise a railway embankment
Authors: Smethurst J. A. , Powrie W.
Published: September 2007

Discrete piles are used to stabilise infrastructure slopes, especially where there is insufficient additional land to allow construction of large toe berms or regrading of the slope. Compared with more conventional structures such as retaining walls, there are few field data on how discrete piles typically bend and displace under slope loading. This paper presents the results from monitoring a number of discrete piles used to stabilise a railway embankment at Hildenborough, Kent, UK. Bending deflections deduced from strain gauges are compared with the displacements and rotations measured by inclinometer tubes cast into the piles. Four years after pile installation, the piles were bending downslope over their lower halves, with little bending measured in the upper sections. Regrading of the rockfill piling platform shortly after pile construction caused some of the pile loading, with further loading caused by the continued tendency for slope movement. Analysis of the piles using a simple elastic analysis gives bending moments and displacements close to those measured.
Mechanical effects of aqueous solutions of inorganic acids and bases on a natural active clay
Authors: Gajo A. , Maines M.
Published: September 2007

The mechanical properties of clays are strongly affected by the pore fluid's chemical composition. Experimental and theoretical analyses have investigated the mechanical effects of exposing clays to aqueous solutions with different salt concentrations and to organic solvents, highlighting the different role of the various cations. With the exception of clay suspensions, no attention has been paid to the effects of pore fluid pH variations on the mechanical behaviour of clays, although clay may be exposed to inorganic acids or bases in many environmental conditions and man-induced situations. The aim of this paper is to investigate how the mechanical behaviour of active clays is affected by pore fluid acidity and alkalinity. Only aqueous solutions of inorganic acids and bases are considered in this study; the rheology of clay suspensions is not investigated. The tests were performed on a natural Na-bentonite, and focused on the influence of pore fluid acidity/alkalinity on the liquid limit, one-dimensional compressibility, permeability and residual strength. Any clay lattice dissolution was found to have negligible mechanical effects. All mechanical effects were reversible, provided the clay was subsequently exposed to an appropriate cycle of acid or alkaline solutions. H+ protons revealed a strong aptitude for adsorption even at low concentrations, causing the desorption of previously adsorbed cations, large volume compression, greater stiffness and residual shear strength. In contrast, exposure to NaOH produced swelling at low concentrations and compression at high concentrations. As a result, the mechanical properties of active clay are strongly affected by even relatively small variations in pore fluid pH. The experimental results are consistent with the concepts of cation exchange on permanently charged surface sites and acid–base reactions on variably charged sites (mainly located at clay edges), and with the assumption of a variable diffuse double layer thickness depending on pore fluid ionic strength. Appropriate sequences of chemical exposures highlight the significant effects of acid–base reactions at particle edges with respect to cation exchange.
Environmental Justice Research and Action: A Case Study in Political Economy and Community-Academic Collaboration
Authors: Tajik Mansoureh , Minkler Meredith
Published: September 2007

Community-university partnerships increasingly are being created to study and address environmental injustices. This article describes a case study of one such effort and its contributions to a decade-long community struggle to curb the growth of industrial hog operations and their adverse health effects in the United States' rural south. Worldwide transformation of livestock production from family farms to large-scale industrial agricultural complexes has resulted in the degradation of local environments, with negative impacts on public health. In the rural south, the concentration of industrial livestock operations has been most pronounced in low income African-American communities. Using political economy and community-based participatory research (CBPR) as a conceptual framework, this article explores the partnership between a strong community-based organization, Concerned Citizens of Tillery, and researchers at the University of North Carolina, Chapel Hill, School of Public Health to study and address this problem. The political, economic, and historical context of the partnership is examined, as are the challenges faced, and the partnership's contributions to maintaining grassroots community organizing and activism and affecting local policy change. Implications for other CBPR partnerships are discussed.
Predictors of Sexual Behavior among out-of-School Adolescents in Nigeria
Authors: Akinwande Oluyemisi , Brieger William R.
Published: September 2007

Purpose:

To examine the influence of specific demographic and socio-cognitive variables on reported condom use among out-of-school adolescents in Nigeria.

Methods:

A cross-sectional study on a community-based sample of 1698 sexually active out-of school adolescents in Oyo state, Nigeria. Data were collected using a non-validated questionnaire administered by an interviewer.

Results:

Nine percent of the sexually-active adolescents reported condom use during sexual intercourse in the past year. Findings of logistic regression showed that adolescents with adequate self-efficacy were seven times more likely to use condom. A two-fold increase in condom use was found in adolescents who value parents' opinion on condom use.

Conclusion:

Results suggest self-efficacy and parents' influence affect condom use among Nigerian adolescents.
The Effect of Iyengar Yoga and Strengthening Exercises for People Living with Osteoarthritis of the Knee: A Case Series
Authors: Bukowski Elaine L. , Conway Allison , Glentz Laura A. , Kurland Kristy , Galantino Mary Lou
Published: September 2007

This case series describes the impact of various forms of exercise on symptoms associated with osteoarthritis of the knee. A group of 15 women and men performed one of the following: traditional stretching and strengthening exercises, Iyengar yoga, or no structured group exercise. Low back and hamstring flexibility and quadriceps strength and function were monitored before and after the program. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used to assess subjective change after the six-week intervention period. A global assessment questionnaire was also completed by each participant and each instructor at the exit sessions to measure perceived changes in improvements since the initiation of the intervention. This study found functional changes and improvement in quality of life in traditional exercise and a yoga based approach that should encourage further comprehensive and carefully designed studies of yoga in osteoarthritis.
Eco-Epidemiology as Anti-Terrorism
Authors: Miller Richard E.
Published: September 2007

Eco-epidemiology is a promising model for cross-disciplinary anti-terrorism. Derived from epidemiology's dominance of agents to illness and injury, the eco-epidemiological paradigm considers natural systems that generate causal pathways to disease and dynamic morbidity. Within this model is a hierarchy of systems interconnecting at biological, human, and social levels. Eco-epidemiology capitalizes on interacting components within and between system levels to identify contact patterns and apply mechanisms of control. Considering the complex and paradoxical nature of the threat-fear dynamic, a systematic, ecological approach would be more adaptive to terrorism's changing rules of engagement. To counter terrorism and nullify threat-fear, eco-epidemiology must be shared by public health researchers with threat assessment and harm reduction disciplines.
The Fundamental Paradox in the Grief Literature: A Critical Reflection
Authors: Breen Lauren J. , O'Connor Moira
Published: September 2007

A key theme in the bereavement literature is the recognition that every grief experience is unique and dependent on many variables, such as the circumstances of the death, characteristics of the bereaved individual, their relationship with the deceased, the provision and availability of support, and a myriad of sociocultural factors. Concurrently, there are corresponding efforts to define “normal” grief and delineate it from “complicated” grief experiences. The discord between these two potentially opposing statements remains a paradox evident within the three major tensions within the thanatological literature—the dominance of grief theories, the medicalization of grief, and the efficacy of grief interventions. Three recommendations for moving beyond the paradox are discussed—the provision of improved grief education for service providers, the bereaved, and the wider community; the conduct of research that emphasizes the context of grief and is relevant to service provision; and the examination of current grief interventions.
Telecommunication and Suicide Prevention: Hopes and Challenges for the New Century
Authors: Krysinska Karolina E. , De Leo Diego
Published: September 2007

Development of information technology has created new opportunities and challenges in suicide prevention, research, and clinical practice. This article presents an overview of the wide range of telecommunication-based suicide prevention approaches. Interventions using the Internet, telephone, and videoconferencing are discussed, including crisis intervention, referral, and support, suicide risk assessment, psychotherapy for individuals at risk, and online-based suicide prevention training and education. Research regarding effectiveness of telecommunication-based suicide prevention in various demographic and clinical populations is reviewed, as well as concerns regarding this type of intervention. Future areas of research and development in the use of telecommunication media in prevention of suicide are discussed.
Childcare Market Management: How the United Kingdom Government Has Reshaped its Role in Developing Early Childhood Education and Care
Authors: Penn Helen
Published: September 2007

This article reviews early education and care policies in the United Kingdom since 1997, when a Labour Government came to power, and sets them in the wider context of international changes. It argues that the Labour Government has, by intention and by default, supported the development of private sector, and especially corporate sector childcare. Corporate childcare has increased sevenfold in the period. The rapid scale of these changes has been ignored, or uncritically accepted, by most commentators. However, the Government's childcare policies have not had the anticipated result of increasing the numbers of mothers in the workforce, with the result that there is considerable oversupply of childcare provision. As a result, the private sector has experienced turmoil, as occupancy rates have fallen to an average of 77%, and the sector has become unprofitable. Within 2005–06 many nurseries closed, and there has been a consolidation of the remainder of the market. The private sector is now actively lobbying for more subsidies and a relaxation of regulations. The article concludes that, despite recent difficulties, trends towards private sector growth will continue and that research is urgently needed to investigate and document the changes.
Pedagogical Silences in Australian Early Childhood Social Policy
Authors: Cheeseman Sandra
Published: September 2007

Growing international interest in the early childhood years has been accompanied by an expansion of public programs in Australia targeting young children and their families. This article explores some of the influences and rhetoric that frame these initiatives. It encourages critical examination of the discourses that shape the nature of early childhood programs in Australia and identifies a range of barriers that inhibit the involvement of early childhood teachers in the design and delivery of social policy initiatives for young children. As the imperatives of programs seeking to overcome social disadvantage take prominence in Australian early childhood policy initiatives, pedagogical perspectives that promote universal rights to more comprehensive early childhood experiences can easily be silenced. The article calls for pedagogical leadership to overcome these barriers and promote the democratic rights of all children to high-quality and publicly supported early childhood education and care programs.
Early Childhood in Ethiopia: Initiatives in Education
Authors: Szente Judit , Hoot James , Tadesse Selamawit
Published: September 2007

This article informs readers about early childhood in one of the poorest nations in the world — Ethiopia. Within the context of ecological systems theory, it emphasizes the characteristics of early education programs such as pre-school and basic (primary) education, and creates connections with families' views about education. The article concludes with recommendations for further research.
Cover Picture: Influence of Plasma Stimulation on Si Nanowire Nucleation and Orientation Dependence (Adv. Mater. 18/2007)
Authors: Aella P. , Ingole S. , Petuskey W. T. , Picraux S. T.
Published: September 2007

On p. 2603, Tom Picraux and co‐workers report on the use of plasma excitation to strongly enhance the nucleation of Si nanowires by the vapor–liquid–solid growth method. This control allows the preferential formation of very small diameter [110] oriented nanowires, as well as significant enhancements in low temperature nanowire growth.
Gold(III) Chloride/Silver Triflate: A Highly Efficient Catalyst for Ring‐Opening Reaction of Aziridines with Electron‐Rich Arenes
Authors: Sun Xiaoyu , Sun Wei , Fan Renhua , Wu Jie
Published: September 2007

Gold(III) chloride/silver triflate was found to a highly efficient catalyst in the ring‐opening of aziridines with electron‐rich arenes and the desired β‐arylamines were afforded in good to excellent yields under mild reaction conditions.
Cross‐Linked Amorphous Nitrilase Aggregates for Enantioselective Nitrile Hydrolysis
Authors: Kaul Praveen , Stolz Andreas , Banerjee U. C.
Published: September 2007

A recombinant Escherichia coli strain was constructed which efficiently expressed the enantioselective nitrilase from Alcaligenes faecalis DSMZ 30030 as a hisitidine‐tagged enzyme variant under the control of a rhamnose inducible promoter. The enzyme was purified from cell extracts and used for the preparation of cross‐linked enzyme aggregates (CLEAs). The conditions for the preparation of the CLEAs were optimized using various organic solvents and cross‐linking agents and a procedure was developed which combined a precipitation with 85 % (v/v) isopropyl alcohol and a cross‐linking with 30 mM glutaraldehyde. Thus, about 80 % of the initial nitrilase activity could be incorporated into the CLEAs. The hydrolysis of racemic mandelonitrile to (R)‐mandelic acid was compared between the soluble nitrilase preparations and their CLEAs (nit‐CLEAs). The nitrilase activity in the CLEAs was at 30 °C and 60 °C about 5 times more stable than in the soluble preparations. The CLEAs could be reused 5 times with only about 10 % reduction in activity. The enantioselectivity of the nitrilase for the formation of (R)‐mandelic acid from racemic mandelonitrile decreased for both preparations with increasing temperatures (10 °C to 50 °C), but this effect was significantly less pronounced for the CLEAs. A detailed analysis of solvent effects on nitrilase enantioselectivity allowed thermodynamic insights into contributions from free energy component (activation enthalpy and entropy) to chiral preference of nitrilase in such non conventional media.
Social facilitation of fur rubbing behavior in white‐faced capuchins
Authors: Meunier H. , Petit O. , Deneubourg J.‐l.
Published: September 2007

In their natural environment, capuchins select certain plants, containing secondary compounds with bactericide, insecticide or fungicide properties, to rub their pelage energetically (i.e. fur rubbing). Fur rubbing can be performed in solitary, or collectively in subgroups of variable size and composition, and most of the time fur rubbing happens in synchrony with other group members. The aim of this study is to understand the underlying mechanisms of this phenomenon, and, more particularly, to determine the processes involved in its synchronization. For this purpose, we designed a set of experiments where white‐faced capuchins (Cebus capucinus) were presented with onions (Allium cepa) that they use to fur rub. We conducted a detailed kinetic study of fur rubbing behavior to determine if its synchronization is the consequence of simultaneous responses of different individuals to the same stimulus or if, on the contrary, there is a real collective phenomenon where individuals respond to conspecific behavior. Our results reveal that fur rubbing is a collective behavior with a mimetic underlying mechanism. If fur rubbing with onions (a plant with antifungal and repellent properties) allows capuchins to treat their fur against parasites or pathogens, its synchronization would optimize the treatment by acting as a group barrier to ectoparasite propagation. Am. J. Primatol. 70:161–168, 2008. © 2007 Wiley‐Liss, Inc.
Oligopotent Mesenchymal Stem Cell‐Like Clone Becomes Multinucleated Following Phorbol Ester, TPA Stimulation
Authors: Yoshida Keiichiro , Ono Michio , Maejima Tatsuo , Esaki Michiyo , Sawada Hajime
Published: September 2007

We established a mesenchymal stem cell clone, 5F9A, from rat bone marrow substrate adherent cells by repeated limiting dilutions. The cells have a fibroblastic shape and form intimate contacts with adjacent cells with interdigitations and junctions similar to adherence and tight junctions in a semi‐confluent culture. Analysis of the phenotypes of these cells by RT‐PCR and FACS demonstrated that they resembled mesenchymal stem cells, and the cells could differentiate into adiopocytes and osteoblasts under appropriate conditions in vitro showing their oligopotency. Furthermore, the cells were induced to become multinuclear cells by TPA (12‐o‐tetradecanoylphorbol 13‐acetate) stimulation. Anat Rec, 290:1256–1267, 2007. © 2007 Wiley‐Liss, Inc.
Cellular Motors for Molecular Manufacturing
Authors: Dinu C.Z. , Chrisey D.B. , Diez S. , Howard J.
Published: September 2007

Cells are composed of macromolecular structures of various sizes that act individually or collectively to maintain their viability and perform their function within the organism. This review focuses on one structure, the microtubule, and one of the motor proteins that move along it, conventional kinesin (kinesin 1). Recent work on the cellular functions of kinesins, such as the organization of microtubules during cellular division and the movement of the organelles and vesicles, offers insights into how biological motors might prove useful for organizing structures in engineered environments. Anat Rec, 290:1203–1212, 2007. © 2007 Wiley‐Liss, Inc.
Improving search engines by query clustering
Authors: Baeza‐Yates Ricardo , Hurtado Carlos , Mendoza Marcelo
Published: September 2007

In this paper, we present a framework for clustering Web search engine queries whose aim is to identify groups of queries used to search for similar information on the Web. The framework is based on a novel term vector model of queries that integrates user selections and the content of selected documents extracted from the logs of a search engine. The query representation obtained allows us to treat query clustering similarly to standard document clustering. We study the application of the clustering framework to two problems: relevance ranking boosting and query recommendation. Finally, we evaluate with experiments the effectiveness of our approach.
Mining Web functional dependencies for flexible information access
Authors: Perugini Saverio , Ramakrishnan Naren
Published: September 2007

We present an approach to enhancing information access through Web structure mining in contrast to traditional approaches involving usage mining. Specifically, we mine the hardwired hierarchical hyperlink structure of Web sites to identify patterns of term‐term co‐occurrences we call Web functional dependencies (FDs). Intuitively, a Web FD ‘x → y’ declares that all paths through a site involving a hyperlink labeled x also contain a hyperlink labeled y. The complete set of FDs satisfied by a site help characterize (flexible and expressive) interaction paradigms supported by a site, where a paradigm is the set of explorable sequences therein. We describe algorithms for mining FDs and results from mining several hierarchical Web sites and present several interface designs that can exploit such FDs to provide compelling user experiences.
Development and validation of a gas chromatography‐mass spectrometry method for the determination of phenazopyridine in rat plasma: application to the pharmacokinetic study
Authors: Chen Qinhua , Li Kaijun , Zhang Zhuo , Li Peng , Liu Jia , Li Qiang
Published: September 2007

Phenazopyridine hydrochloride is a strong analgesic used in the treatment of urinary tract infections. The aim of the present study was to develop a procedure based on gas chromatography‐mass spectrometry (GC‐MS) for the analysis of phenazopyridine in rat plasma. The method was set up and adapted for the analysis of small biological samples taken from rats. Biological samples were extracted by liquid–liquid extraction. The extraction agent was ethyl acetate. The samples were separated by GC on a DB‐5MS analytical column and determined by a quadrupole mass spectrometer detector operated under selected ion monitoring mode. Excellent linearity was found between 0.01 and 1.00 µg/ml (r = 0.9991, n = 9) for plasma samples. The limit of detection (LOD) was 0.3 ng/ml. Within‐day and between‐day precisions expressed as the relative standard deviation (RSD) for the method were 1.83–4.91% and 2.12–4.76%, respectively. The recoveries for all samples were >90%. The main pharmacokinetic parameters obtained were Tmax = (0.35±0.01) h, Cmax = (0.396±0.079) µg/ml, AUC = (0.373±0.065) h µg/ml and CL = (94.2±5.9) ml/g/h. The results presented here clearly indicate that this proposed method could be applicable to investigate the pharmacokinetic of phenazopyridine in rats after administration. Copyright © 2007 John Wiley & Sons, Ltd.
Finding Y‐relevant part of X by use of PCR and PLSR model reduction methods
Authors: Ergon Rolf
Published: September 2007

The paper is considering the following question: using principal component regression (PCR) or partial least squares regression (PLSR), how much data can be removed from X while retaining the original ability to predict Y? Two model reduction methods using similarity transformations are discussed, one giving projections of original loadings onto the column space of the fitted response matrix $\hat {\bf Y}$ (essentially the orthogonal signal correction (OSC) methods), and one giving projections of original scores onto the column space of the coefficient matrix $\hat {\bf B}$ (essentially the net analyte signal (NAS) methods). The loading projection method gives model residuals that are orthogonal to Y and $\hat {\bf Y}$, which is valuable in certain applications. The score projection method, on the other hand, gives model residuals that are orthogonal to $\hat {\bf B}$, which is essential in other applications. It is shown that the reduced matrix X from the score projection method is a subset of the reduced matrix X from the loading projection method. It therefore has the smallest Frobenius norm, and thus the smallest total column variance, assuming centered data. Copyright © 2007 John Wiley & Sons, Ltd.
Long‐term results of a prospective study on the treatment of medulloblastoma in adults
Authors: Brandes Alba A. , Franceschi Enrico , Tosoni Alicia , Blatt Valeria , Ermani Mario
Published: September 2007

BACKGROUND.

Because medulloblastoma (MB) is rare in adults, the few studies on this condition have been retrospective, and the follow‐up has tended to be short. Furthermore, the different therapeutic strategies used in these patients has made it difficult to assess survival rates and prognostic factors.

METHODS.

In 1989, a prospective Phase II trial was initiated to evaluate the efficacy of treatment for adults with MB. Patients were staged completely with a neuroradiologic examination of the brain and neuroaxis and by cerebrospinal fluid cytology, according to Chang's staging system. Low‐risk patients received radiotherapy alone, whereas high‐risk patients received 2 cycles of upfront chemotherapy followed by radiotherapy and adjuvant chemotherapy. The current article reports on the long‐term results from that trial.

RESULTS.

After a median follow up of 7.6 years, among a total of 36 adults with MB, the overall progression‐free survival (PFS) and overall survival (OS) rates at 5 years were 72% and 75%, respectively. In low‐risk patients, the 5‐year PFS rate was 80%, and the 5‐year OS rate was 80%; in high‐risk patients, the 5‐year PFS rate was 69%, and the 5‐year OS rate was 73%.

CONCLUSIONS.

In adult patients with MB, long‐term follow‐up was essential for evaluating the real impact of treatments. Low‐risk and high‐risk patients did not differ significantly in terms of PFS or OS. Cancer 2007. © 2007 American Cancer Society.
Percentage of Gleason pattern 4 and 5 predicts survival after radical prostatectomy
Authors: Cheng Liang , Davidson Darrell D. , Lin Haiqun , Koch Michael O.
Published: September 2007

BACKGROUND.

Morphologic and clinical heterogeneity within tumor grades is well recognized in prostate cancer. The objective of the current study was to determine whether the combined percentage of Gleason patterns 4 and 5 in radical prostatectomy specimens is an independent predictor of cancer‐specific survival in prostate cancer patients.

METHODS.

The radical prostatectomy specimens were analyzed from 504 consecutive prostate cancer patients who were treated at Indiana University Medical Center between 1990 and 1998. Various clinical and pathologic characteristics were analyzed.

RESULTS.

A higher combined percentage of Gleason patterns 4 and 5 was associated with older age, higher preoperative serum prostate‐specific antigen level, higher pathologic stage, positive surgical margins, extraprostatic extension of tumor, higher Gleason score, perineural invasion, and lymph node metastasis. In the multivariate Cox regression model, the combined percentage of Gleason patterns 4 and 5 was found to be an independent predictor of cancer‐specific survival (P = .04).

CONCLUSIONS.

The combined percentage of Gleason patterns 4 and 5 is a powerful predictor of prostate cancer‐specific survival. Assessment of high‐grade cancer amounts may allow for better stratification of patients into appropriate prognostic groups and treatment protocols. Cancer 2007. © 2007 American Cancer Society.
Plasma‐Enhanced CVD for Particle Synthesis Using Circulating Fluidized Bed Technology
Authors: von Rohr P. R. , Borer B.
Published: September 2007

Circulating fluidized beds (CFB) are widely used for gas‐solid reactions. This presentation summarizes specific design and operational features for a CFB system with a non‐thermal plasma. The results of coating a glass‐like material using salt particles as a model substrate are shown. The potential of the new technology is broad, due to the fact that plasma‐enhanced (PE)CVD can be used to combine and treat virtually any two different materials at low temperatures.
Aromatase expression and cell proliferation following injury of the adult zebra finch hippocampus
Authors: Peterson R. Scott , Fernando Gowry , Day Lainy , Allen Timothy A. , Chapleau Jeanette D. , Menjivar Jenny , Schlinger Barney A. , Lee Diane W.
Published: September 2007

Estrogens can be neuroprotective following traumatic brain injury. Immediately after trauma to the zebra finch hippocampus, the estrogen‐synthetic enzyme aromatase is rapidly upregulated in astrocytes and radial glia around the lesion site. Brain injury also induces high levels of cell proliferation. Estrogens promote neuronal differentiation, migration, and survival naturally in the avian brain. We suspect that glia are a source of estrogens promoting cell proliferation after neural injury. To explore this hypothesis, we examined the spatial and temporal relationship between glial aromatase expression and cell proliferation after neural injury in adult female zebra finches. Birds were ovariectomized and given a blank implant or one filled with estradiol; some birds were also administered an aromatase inhibitor or vehicle. All birds received penetrating injuries to the right hippocampus. Twenty‐four hours after lesioning, birds were injected once with BrdU to label mitotically active cells and euthanized 2 h, 24 h, or 7 days later. The brains were processed for double‐label BrdU and aromatase immunocytochemistry. Injury‐induced glial aromatase expression was unaffected by survival time and aromatase inhibition. BrdU labeling was significantly reduced at 24 h by ovariectomy and by aromatase inhibition; effects were partially reversed by E2 replacement. Irrespective of ovariectomy, the densities of aromatase immunoreactive astrocytes and BrdU‐labeled cells at known distances from the lesion site were highly correlated. These data suggest that injury‐induced glial aromatization may influence the reorganization of injured tissue by providing a rich estrogenic environment available to influence cellular incorporation. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007.
XSUMO‐1 is required for normal mesoderm induction and axis elongation during early Xenopus development
Authors: Yukita Akira , Michiue Tatsuo , Danno Hiroki , Asashima Makoto
Published: September 2007

The small ubiquitin‐related modifier (SUMO) is a member of the ubiquitin‐like protein family, and SUMO conjugation (SUMOylation) resembles ubiquitination. Despite many SUMOylation target proteins being reported, the role of this system in vertebrate development remains unclear. We inhibited the function of Xenopus SUMO‐1 (XSUMO‐1) using a morpholino antisense oligo against XSUMO‐1 (XSUMO‐1‐MO) to clarify the role of SUMOylation. XSUMO‐1‐MO inhibited normal axis formation in embryos and elongation of activin‐treated animal caps. The expression of several mesoderm markers was reduced by XSUMO‐1‐MO. We measured activin‐like activity by using a reporter construct containing a multimer of activin‐responsive elements from the Goosecoid promoter, [DE(6x)Luc]. This assay showed that XSUMO‐1‐MO directly inhibited activin/nodal signaling. Furthermore, XSUMO‐1‐MO inhibited ectopic axis formation induced by XSmad2, and XSmad2/4 mRNA could not rescue the axis elongation defect induced by XSUMO‐1‐MO. These results suggested that XSUMO‐1 is required for normal axis elongation, at least partly mediating activin/nodal signaling. Developmental Dynamics 236:2757–2766, 2007. © 2007 Wiley‐Liss, Inc.
Neural MMP‐28 expression precedes myelination during development and peripheral nerve repair
Authors: Werner Sean R. , Mescher Anthony L. , Neff Anton W. , King Michael W. , Chaturvedi Shalini , Duffin Kevin L. , Harty Mark W. , Smith Rosamund C.
Published: September 2007

Mammalian matrix metalloproteinase 28 (MMP‐28) is expressed in several normal adult tissues, and during cutaneous wound healing. We show that, in frog and mouse embryos, MMP‐28 is expressed predominantly throughout the nervous system. Xenopus expression increases during neurulation and remains elevated through early limb development where it is expressed in nerves. In the mouse, neural expression peaks at embryonic day (E) 14 but remains detectable through E17. During frog hindlimb regeneration XMMP‐28 is not initially expressed in the regenerating nerves but is detectable before myelination. Following hindlimb denervation, XMMP‐28 expression is detectable along regenerating nerves before myelination. In embryonic rat neuron–glial co‐cultures, MMP‐28 decreases after the initiation of myelination. Incubation of embryonic brain tissue with purified MMP‐28 leads to the degradation of multiple myelin proteins. These results suggest that MMP‐28 plays an evolutionarily conserved role in neural development and is likely to modulate the axonal–glial extracellular microenvironment. Developmental Dynamics 236:2852–2864, 2007. © 2007 Wiley‐Liss, Inc.
Regulated expression of the ubiquitin protein ligase, E3Histone/LASU1/Mule/ARF‐BP1/HUWE1, during spermatogenesis
Authors: Liu Zhiqian , Miao Dengsheng , Xia Qingwen , Hermo Louis , Wing Simon S.
Published: September 2007

A ubiquitin protein ligase (E3), E3Histone/LASU1 (Mule/ARF‐BP1/HUWE1), was recently identified that mediates ubiquitination of core histones, the Mcl‐1 anti‐apoptotic protein, and the p53 tumor suppressor protein. However, the expression of E3Histone/LASU1 remains poorly studied. Because we identified E3Histone/LASU1 from the testis, we explored its regulation during spermatogenesis. In the first wave of rat spermatogenesis, E3Histone/LASU1 mRNA and protein had peak expression at days 10 and 20, respectively, and decreased with age. Consistent with these findings, immunohistochemistry revealed that E3Histone/LASU1 was highly expressed in nuclei from spermatogonia to mid‐pachytene spermatocytes. There was no obvious staining in spermatids, when histones are ubiquitinated and degraded. E3Histone/LASU1 was also expressed in other tissues. However, except in neuronal cells of the brain, expression was cytoplasmic. Thus, E3Histone/LASU1 may play a role in chromatin modification in early germ cells of the testis, but also has functions in other tissues. Developmental Dynamics 236:2889–2898, 2007. © 2007 Wiley‐Liss, Inc.
Directing the differentiation of embryonic stem cells to neural stem cells
Authors: Cai Chunyu , Grabel Laura
Published: September 2007

Embryonic stem cells (ESCs) are a potential source of neural derivatives that can be used in stem cell‐based therapies designed to treat neurological disorders. The derivation of specific neuronal or glial cell types from ESCs invariably includes the production of neural stem cells (NSCs). We describe the basic mechanisms of neural induction during vertebrate embryogenesis and how this information helped formulate several protocols used to generate NSCs from ESCs. We highlight the advantages and disadvantages of each approach and review what has been learned about the intermediate stages in the transition from ESC to NSC. Recent data describing how specific growth factors and signaling molecules regulate production of NSCs are described and a model synthesizing this information is presented. Developmental Dynamics 236:3255–3266, 2007. © 2007 Wiley‐Liss, Inc.
The proliferating field of neural crest stem cells
Authors: Delfino‐Machín Mariana , Chipperfield Thomas R. , Rodrigues Frederico S.L.M. , Kelsh Robert N.
Published: September 2007

Neural crest stem cells were first isolated from early embryonic neural crest in the early 1990s, but in the past 5 years, there has been a burst of discoveries of neural crest‐derived stem cells from diverse locations. Here, we summarize these data, highlighting the characteristics of each stem cell type. These cells vary widely in the markers they express and the variety of cell types they appear to generate. They occupy diverse locations, but in some cases multiple stem cell types apparently occupy physically proximate niches. To date, few molecular similarities can be identified between these stem cells, although a systematic comparison is required. We note other issues worthy of attention, including aspects of the in vivo behavior of these stem cells, their niches, and their lineage relationships. Together, analysis of these issues will clarify this expanding, but still young, field and contribute to exploration of the important therapeutic potential of these cells. Developmental Dynamics 236:3242–3254, 2007. © 2007 Wiley‐Liss, Inc.
Determination of copper(I) and copper(II) ions after complexation with bicinchoninic acid by CE
Authors: Basheer Chanbasha , Lee Hian Kee
Published: September 2007

A facile, sensitive, and selective method was developed for the simultaneous separation and determination of copper(I) [Cu+] and copper(II) [Cu2+] ions using CE with direct UV detection. The copper ions were complexed with a 1.5 mM bicinchoninic acid disodium salt solution at pH 8.7 prior to analysis. Acetate buffer (2 mM) was used as the CE running buffer. Parameters affecting CE separation such as sample pH, applied voltage, concentration of complexing agent, nature of the buffer solution, and interferences by other metal ions, were evaluated. The LODs for Cu+ and Cu2+ were 3.0 and 2.5 μg/mL (S/N = 3), respectively. The developed method allows the simultaneous determination of Cu+ and Cu2+ in less than 5 min with RSDs of between 5.3 and 9.5% for migration time and between 3.4 and 9.7% for peak areas, respectively. At optimum conditions, the percentage recoveries of Cu+ and Cu2+ were found to be 99.4 and 99.5%.
Desorption of methy‐ethyl‐ketone from granular activated carbon with microwave radiation
Authors: Tai Hua‐Shan , Lee Chien‐li
Published: September 2007

Granular‐activated carbon (GAC) is an excellent microwave (MW) absorbing material to absorb and convert MW energy into thermal energy. The removal of adsorbed methyl ethyl ketone (MEK) on GAC for regenerating the saturated GAC using MW energy was presented in this article. The result shows that the treatment time for achieving 80% desorption efficiency using 200‐W MW power output is 4 min for 5 g MEK adsorbed on 5 g GAC and 6 min for 3 g MEK adsorbed on 5 g GAC. The MW treatment recovers the adsorbed MEK from the inner pores of the carbon granules to restore the original adsorption capacity and surface area of the activated carbon. The MW‐induced regeneration allows the saturated GAC to be regenerated on site and provides an economic method to remove and destroy solvents emitted from small sources by using the GAC‐bed treatment. © 2007 American Institute of Chemical Engineers Environ Prog, 2007