bluuebunny/crossref_metadata_2025 huggingface dataset:
Glutamate Levels in Cerebrospinal Fluid and Triptans Overuse in Chronic Migraine
Authors: Vieira Domingos Sávio deSouza , Naffah‐Mazzacoratti Maria da Graça , Zukerman Eliova , Soares Carlos Augusto Senne , Cavalheiro Esper Abräo , Peres Mario Fernando Prieto
Published: May 2007

Objective.—Chronic migraine (CM) is a common disorder, affecting 2% to 3% of the general population. Glutamate is implicated in cortical spreading depression, trigeminovascular activation, central sensitization, and may be linked to migraine chronification. Triptans brought a novel option for the acute migraine treatment. As the development of central sensitization impacts upon the effectiveness of triptan therapy, we hypothesized that glutamate might be related to triptan response mechanisms.

Methods.—We studied 19 patients diagnosed with CM according to the International Headache Society (2004) criteria. Patients were divided in those overusing analgesics (NSAIDs); those without overuse, and those overusing triptans.

Results.—Cerebrospinal fluid (CSF) glutamate levels were similar in patients overusing acute medications (0.335 ± 0.225 μmol) compared to those without overuse (0.354 ± 0.141 μmol), P= NS). In contrast, patients overusing triptans had CSF glutamate levels significantly lower than that observed in nonoverusers (0.175 ± 0.057 vs 0.354 ± 0.141 μmol, P= 0.015), and significantly higher than controls (0.175 ± 0.057 vs 0.109 ± 0.066 μmol, P= 0.039). In triptan overusers, CSF glutamate levels, although lower, were not significantly different from patients overusing other types of analgesics.

Conclusions.—Our study showed lower glutamate levels in CSF of CM patients overusing triptans. Glutamate may be implicated in triptan response mechanisms, triptans may work in part by reducing extracellular glutamate levels in the brain.
On the Ethical Justification for the Use of Risk Acceptance Criteria
Authors: Aven Terje
Published: May 2007

To protect people from hazards, the common safety regulation regime in many industries is based on the use of minimum standards formulated as risk acceptance or tolerability limits. The limits are seen as absolute, and in principle these should be met regardless of costs. The justification is ethical—people should not be exposed to a risk level exceeding certain limits. In this article, we discuss this approach to safety regulation and its justification. We argue that the use of such limits is based on some critical assumptions; that low accident risk has a value in itself, that risk can be accurately measured and the authorities specify the limits. However, these assumptions are not in general valid, and hence the justification of the approach can be questioned. In the article, we look closer into these issues, and we conclude that there is a need for rethinking this regulation approach—its ethical justification is not stronger than for alternative approaches. Essential for the analysis is the distinction between ethics of the mind and ethics of the consequences, which has several implications that are discussed.
Selection Bias and Auditing Policies for Insurance Claims
Authors: Pinquet Jean , Ayuso Mercedes , Guillén Montserrat
Published: May 2007

Abstract

Selection bias results from a discrepancy between the range of estimation of a statistical model and its range of application. This is the case for fraud risk models, which are estimated on audited claims but applied on incoming claims in the design of auditing strategies. Now audited claims are a minority within the parent sample since they are chosen after a severe selection performed by claims adjusters. This article presents a statistical approach that counteracts selection bias without using a random auditing strategy. A two‐equation model on audit and fraud (a bivariate probit model with censoring) is estimated on a sample of claims where the experts are left free to take the audit decision. The expected overestimation of fraud risk derived from a single‐equation model is corrected. Results are close to those obtained with a random auditing strategy, at the expense of some instability with respect to the regression components set. Then we compare auditing policies derived from the different approaches.
Genetic characterization of wild and captive rhesus macaques in China*
Authors: Satkoski J. , George D. , Smith D.G. , Kanthaswamy S.
Published: May 2007

The genetic structures of wild and captive rhesus macaque populations within China were compared by analyzing the mtDNA sequences of 203 captive‐bred Chinese rhesus macaques with 77 GenBank sequences from wild‐caught animals trapped throughout China. The genotypes of 22 microsatellites of captive Chinese rhesus macaques were also compared with those of captive Indian animals. The Chinese population is significantly differentiated from the Indian population and is more heterogeneous. Thus, compared with Indian rhesus macaques the phenotypic variance of traits with high heritability will be inflated in Chinese animals. Our data suggest that the western Chinese provinces have more subdivided populations than the eastern and southern Chinese provinces. The southern Chinese populations are the least structured and might have been more recently established. Human‐mediated interbreeding among captive Chinese populations has occurred, implying that Chinese breeding strategies can influence the interpretation of biomedical research in the USA.
Myosins in melanocytes: to move or not to move?
Authors: Coudrier Evelyne
Published: May 2007

The actin network has been implicated in the intracellular transport and positioning of the melanosomes, organelles that are specialized in the biosynthesis and the storage of melanin. It contributes also to molecular mechanisms that underlie the intracellular membrane dynamics and thereby can control the biogenesis of melanosomes. Two mechanisms for actin‐based movements have been identified: one is dependent on the motors associated to actin namely the myosins; the other is dependent on actin polymerization. This review will focus on to the role of the actin cytoskeleton and myosins in the transport and in the biogenesis of melanosomes. Myosins involved in membrane traffic are largely seen as transporters of organelles or membrane vesicles containing cargos along the actin networks. Yet increasing evidence suggests that some of the myosins contribute to the dynamics of internal membrane by using other mechanisms. The role of the myosins and the different molecular mechanisms by which they contribute or may contribute to the distribution, the movement and the biogenesis of the melanosomes in epidermal melanocytes and retinal pigmented epithelial (RPE) cells will be discussed.
Molecular Basis for Autoregulatory Interaction Between GAE Domain and Hinge Region of GGA1
Authors: Inoue Michio , Shiba Tomoo , Ihara Kentaro , Yamada Yusuke , Hirano Satoshi , Kamikubo Hironari , Kataoka Mikio , Kawasaki Masato , Kato Ryuichi , Nakayama Kazuhisa , Wakatsuki Soichi
Published: May 2007

Golgi‐localizing, γ‐adaptin ear domain homology, ADP ribosylation factor‐binding (GGA) proteins and the adaptor protein (AP) complex, AP‐1, are involved in membrane traffic between the trans Golgi network and the endosomes. The γ‐adaptin ear (GAE) domain of GGAs and the γ1 ear domain of AP‐1 interact with an acidic phenylalanine motif found in accessory proteins. The GAE domain of GGA1 (GGA1‐GAE) interacts with a WNSF‐containing peptide derived from its own hinge region, although the peptide sequence deviates from the standard acidic phenylalanine motif. We report here the structure of GGA1‐GAE in complex with the GGA1 hinge peptide, which revealed that the two aromatic side chains of the WNSF sequence fit into a hydrophobic groove formed by aliphatic portions of the side chains of conserved arginine and lysine residues of GGA1‐GAE, in a similar manner to the interaction between GGA‐GAEs and acidic phenylalanine sequences from the accessory proteins. Fluorescence quenching experiments indicate that the GGA1 hinge region binds to GGA1‐GAE and competes with accessory proteins for binding. Taken together with the previous observation that γ1 ear binds to the GGA1 hinge region, the interaction between the hinge region and the GAE domain underlies the autoregulation of GGA function in clathrin‐mediated trafficking through competing with the accessory proteins and the AP‐1 complex.
Developing a corpus of the nursing literature: A pilot study
Authors: BUDGELL Brian , MIYAZAKI Michiko , O’BRIEN Myles , PERKINS Robert , TANAKA Yoshiko
Published: May 2007

Aim:  The purpose of this project was to develop and analyze a pilot corpus of the nursing literature.

Methods:  The first issues for 2005 of six representative nursing journals were used to create a corpus of ≈ 250,000 words. This corpus was analyzed for word frequency using a concordance software package.

Results:  The process of developing and analyzing the corpus took the equivalent of ≈ 2 weeks’ work for a single person. Approximately 7000 unique words were identified and sorted according to frequency.

Conclusions:  In terms of time and cost, the development and analysis of a corpus is an efficient way of identifying the vocabulary which the nursing profession uses in its research publications. Even this brief pilot exercise was able to identify previously unexpected patterns of usage.
Autoimmune hepatitis complicated by late‐onset systemic lupus erythematosus
Authors: Takahashi Atsushi , Rai Tsuyoshi , Onizawa Michio , Monoe Kyoko , Kanno Yukiko , Saito Hironobu , Abe Kazumichi , Yokokawa Junko , Irisawa Atsushi , Ohira Hiromasa
Published: May 2007

A 69‐year‐old man with autoimmune hepatitis (AIH) was admitted to hospital with high fever and cough. Chest roentgenogram and computed tomography showed pleural and pericardial effusion. Serological tests showed a high titer of antinuclear antibodies and positive anti‐DNA antibody and lymphocytopenia. He fulfilled the American College of Rheumatology criteria for systemic lupus erythematosus (SLE). After administration of corticosteroids, his symptoms and liver dysfunction improved. To the authors’ knowledge, this is the first male case of overlap between AIH and late‐onset SLE.
Hall Potential Profiles in Quantum Hall Samples Measured by a Low-Temperature Scanning Force Microscope
Authors: WEIS JÜRGEN
Published: May 2007

Our measurements of the Hall potential distribution in GaAs/AlGaAs quantum Hall samples using a scanning force microscope at a temperature of 1.4 K are reviewed. The results emphasize the important role of compressible and incompressible strips, running along the edges of the two-dimensional electron system (2DES), for the quantum Hall effect. At the interface line between the 2DES and its alloyed metal contact with good ohmic behavior, a partial depletion of the electron concentration in the 2DES in front of contact is identified, causing for certain magnetic field regimes an incompressible strip lying in parallel to the interface line and therefore isolating the compressible 2DES bulk from the 2DES edge with the contact.
INFLUENCE OF NEARBY QD LAYER ON 2DES IN QUANTUM HALL REGIME
Authors: TAKEHANA K. , IMANAKA Y. , TAKAMASU T. , HENINI M.
Published: May 2007

We have investigated transport properties in high magnetic field of a gated two-dimensional electron system (2DES) separated by a thin barrier from a layer of self-assembled InAs quantum dots (QDs) in the quantum Hall regime. The quality of 2DES was found to be high enough to observe both integer and fractional quantum Hall effect (QHE), despite the proximity of the QD layer to the 2DES. However, significant suppression of the magnetoresistance (ρ xx ) and Hall resistance (ρ xy ) were observed in higher magnetic field range of filling factor ν < 1 when a positive voltage was applied to the front gate. The gate voltage dependence of ρ xx and ρ xy shows a well-defined hysteresis loop at the narrow gate voltage range between -0.2 and +0.2 V at ν < 1, while no anomaly was observed at ν > 1. We deduce that charging and discharging of QDs occurs when the gate voltage is varied around Vg ~ 0 V, which indicates that the electron charge states of the QDs affect the transport properties of the nearby 2DES only at ν < 1. We infer that the spin-flip process induces a non-equilibrium state in the 2DEG, which causes the suppression of ρ xx and ρ xy .
RESPONSE OF A 2DEG TO MICROWAVE IRRADIATION
Authors: Moreau S. , Fedorych O. M. , Sadowski M. L. , Potemski M. , Studenikin S. , Austing G. , Sachrajda A. S. , Saku T. , Hirayama Y.
Published: May 2007

In this paper, we study the behavior of a high mobility two dimensional electron gas under microwave irradiation by means of magneto-photoluminescence (PL) and absorption measurements. The high mobility sample investigated is a 15nm wide GaAs/AlGaAs quantum well with an electron concentration between 1-2×1011 cm -2, tunable by visible-light illumination. Structures in the microwave absorption at 40-60GHz are identified as geometrically confined magneto-plasmons.
MAGNETOPHONON RESONANCE IN MnxCdyHg1-x-yTe
Authors: PLOCH D. , CEBULSKI J. , SHEREGII E. M.
Published: May 2007

The aim of this work is to analyze the band-structure parameters of Mn x Cd y Hg 1- x - y Te (MMCT) alloys by means of Magnetophonon Resonance (MPR) and to compare that obtained for Zn x Cd y Hg 1- x - y Te (ZMCT). MPR was observed for two samples of Mn x Cd y Hg 1- x - y Te (MMCT) (I- x =0.095 and y =0.09, II-0.04 and y =0.19). The measurements of MPR were performed in pulsed magnetic fields at different temperatures ranging from 77 K to 200 K. The several wide maxima are clearly visible on the experimental curves corresponding to four series of peaks. These series are related to three kinds of phonons analogous to ZMCT.

The system of MPR peaks in MMCT is shifted significantly to the higher magnetic fields in comparison with the ZMCT resonance curves of approximately the same content of Zn . The value of effective mass obtained by MPR experiment is of 66% greater than those calculated in the framework of three-band Kane model, in which the value of Eg, was extracted from the photoconductivity data.
USER PROFILING IN THE CHRONOBOT/VIRTUAL CLASSROOM SYSTEM
Authors: LI XIN , CHANG SHI-KUO
Published: May 2007

The Chronobot/Virtual Classroom (CVC) system is a novel time knowledge exchange platform where any pair of users can exchange their time and knowledge. User profile that contains user attributes, preferences, and learning patterns serves as a primary basis to identify exchange partners and determine exchange rates. In this paper, we described the methodology to acquire knowledge about users i.e. user profile from their activities. The association between user profile and user behaviors (e.g. online reading, chatting and time/knowledge exchanging) is identified by several feedback indicators extracted from browsing history, chatting session and exchange transaction. A linear learning model is constructed to fuse multiple feedback indicators to infer user preference. The methods utilizing user profile to identify the exchange partners and determine the exchange rate are also described in detail.
FROM HIPPOCRATIC DATABASES TO SECURE TROPOS: A COMPUTER-AIDED RE-ENGINEERING APPROACH
Authors: MASSACCI FABIO , MYLOPOULOS JOHN , ZANNONE NICOLA
Published: May 2007

Privacy protection is a growing concern in the marketplace. Yet, privacy requirements and mechanisms are usually retro-fitted into a pre-existing design which may not be able to accommodate them due to potential conflicts with functional requirements.

We propose a procedure for automatically extracting privacy requirements from databases supporting access control mechanisms for personal data (hereafter Hippocratic databases) and representing them in the Secure Tropos framework where tools are available for checking the correctness and consistency of privacy requirements. The procedure is illustrated with a case study.
Hair Relaxers Not Associated with Breast Cancer Risk: Evidence from the Black Women's Health Study
Authors: Rosenberg Lynn , Boggs Deborah A. , Adams-Campbell Lucile L. , Palmer Julie R.
Published: May 2007

Hair relaxers (straighteners) have been used by millions of African American women, often for many years. Relaxer ingredients can enter the body through scalp lesions and burns. Because manufacturers are not required to list all ingredients, these products may contain unknown harmful substances. We assessed hair relaxer use in relation to breast cancer incidence in the Black Women's Health Study, a nationwide follow-up study of African American women. Information on hair relaxer use was collected in 1997; 48,167 women were followed subsequently through 2003 for incident breast cancer. Incidence rate ratios of breast cancer were estimated with Cox regression. During 266,298 person-years of follow-up, 574 incident cases of breast cancer were ascertained. There were no increases in breast cancer risk associated with any categories of duration of hair relaxer use, frequency of use, age at first use, number of burns experienced during use, or type of relaxer used. The incidence rate ratio for use at least seven times a year for 20 or more years relative to use for less than a year was 0.98 (95% confidence interval, 0.78-1.39). These results suggest that hair relaxer use does not increase the incidence of breast cancer in African American women. (Cancer Epidemiol Biomarkers Prev 2007;16(5):1035–7)
Pulmonary Hypertension in Sickle-Cell Disease: Comorbidities and Echocardiographic Findings
Authors: Akgül Ferit , Yalçın Fatih , Seyfeli Ergün , Uçar Edip , Karazincir Sinem , Balci Ali , Gali Edip
Published: May 2007

Background: Our aim is to determine comorbidities associated with pulmonary hypertension (PHT) in clinically stable sickle-cell disease (SCD) patients and to evaluate left ventricular (LV) and right ventricular (RV) function in those patients. Methods: Echocardiography was performed in 87 SCD patients that were divided into group I (without PHT) and group II (with PHT). Both groups were compared with healthy controls. Results: A history of retinopathy and leg ulcer was more frequent in group II than group I (p < 0.01). Haemoglobin levels were lower (p < 0.05), whereas blood urea nitrogen, lactate dehydrogenase and total bilirubin levels were higher in group II (p < 0.01). Although group II patients had larger LV end-diastolic, LV end-systolic and RV diastolic diameters compared with group I patients and controls (p < 0.05), LV ejection fraction was similar in the three groups. The mitral peak early diastolic inflow velocity to peak late diastolic inflow velocity (E/A) ratio was similar in group I, group II and the control group. The tricuspid E/A ratio was lower in group II than group I and controls (p < 0.05). Conclusion: End organ damage occurs more often and haemolysis is severer in SCD patients with PHT than SCD patients without PHT. Although LV systolic and diastolic function is well preserved, RV diastolic function is disturbed in those patients with PHT.
A Proteomic Study to Identify Soya Allergens – The Human Response to Transgenic versus Non-Transgenic Soya Samples
Authors: Batista Rita , Martins Isabel , Jenö Paul , Ricardo Cândido Pinto , Oliveira Maria Margarida
Published: May 2007

Background: In spite of being among the main foods responsible for allergic reactions worldwide, soybean (Glycine max)-derived products continue to be increasingly widespread in a variety of food products due to their well-documented health benefits. Soybean also continues to be one of the elected target crops for genetic modification. The aim of this study was to characterize the soya proteome and, specifically, IgE-reactive proteins as well as to compare the IgE response in soya-allergic individuals to genetically modified Roundup Ready soya® versus its non-transgenic control. Methods: We performed two-dimensional gel electrophoresis of protein extracts from a 5% genetically modified Roundup Ready flour sample and its non-transgenic control followed by Western blotting with plasma from 5 soya-sensitive individuals. We used peptide tandem mass spectrometry to identify soya proteins (55 protein matches), specifically IgE-binding ones, and to evaluate differences between transgenic and non-transgenic samples. Results: We identified 2 new potential soybean allergens – one is maturation associated and seems to be part of the late embryogenesis abundant proteins group and the other is a cysteine proteinase inhibitor. None of the individuals tested reacted differentially to the transgenic versus non-transgenic samples under study. Conclusion: Soybean endogenous allergen expression does not seem to be altered after genetic modification. Proteomics should be considered a powerful tool for functional characterization of plants and for food safety assessment.
Inductions of Histidine Decarboxylase in Mouse Tissues following Systemic Antigen Challenge: Contributions Made by Mast Cells, Non-Mast Cells and IL-1
Authors: Deng Xue , Wu Xia , Yu Zhiqian , Arai Iwao , Sasano Takashi , Sugawara Shunji , Endo Yasuo
Published: May 2007

Background: Previous findings suggest that antigen challenge (AC) may induce histidine decarboxylase (HDC) in cells other than mast cells (MCs) via MC-derived IL-1. We examined this hypothesis. Methods: Mice were sensitized to ovalbumin. After the sensitization, an AC was delivered intravenously. Results: In control mice, AC markedly induced HDC at a postanaphylactic time in the liver, lung, spleen, and ears. In MC-deficient W/Wv mice, AC also induced HDC, although the effect was weaker than in control mice. AC increased IL-1 in the tissues, the pattern being similar in W/Wv and control mice. AC induced HDC similarly in IL-1-deficient and control mice. In control mice, AC decreased histamine in the tissues (except the liver) for several hours. Conclusion: (1) AC induces HDC in both MC-dependent and MC-independent ways. (2) AC induces IL-1 mostly in non-MCs, but this IL-1 is not a prerequisite for the induction of HDC by AC. (3) HDC induction may contribute to the replenishment of the reduced pool of MC histamine in the anaphylactic period. (4) In the case of MC-dependent HDC induction, AC may stimulate MCs in such a way as to induce HDC within the MCs themselves, and/or AC-stimulated MCs may stimulate HDC induction in other cells, which will need to be directly identified in future studies.
Chronic Intracortical EEG Recordings in the Diagnosis and Treatment of ‘Partial’ Epilepsies
Authors: Crandall P. , Walter R. , Walsh G.
Published: May 2007

Experience has been gained with stereotactically implanted, bipolar electrodes and direct brain recordings for periods of up to 1 month in 50 patients with suspected psychomotor epilepsy and 10 patients with other forms of ''partial epilepsy'' uncontrolled by medical treatment. Identification of the seizure foci had not been achieved by previous EEG, neurological, or radiological studies. Localization of a single seizure focus shown to initiate three of more spontaneous clinical seizures was possible in three fourths of this group and led to definitive surgical treatment. Placement of stereotactic electrodes varied according to the patient''s symptoms, and the approaches were limited to regions involved with the pathological substrate. In psychomotor epilepsy these were confined to limbic system sites. In other ''partial'' epilepsies several sites in suspected regions were utilized. These criteria will be further detailed. Methods included the stereotactic coordinates of Talairach et al., the Todd-Wells stereotactic apparatus, the hollow screw technique for chronically implanted electrodes, continuous radio-telemetry during varying states – waking, sleeping, during daily activities, during stimulations (photic, auditory, somatosensory, under influence of various drugs) and with videotape recordings of simultaneous behavior and EEG data. The interictal and ictal EEG correlates with various clinical patterns of the ''partial epilepsies'' will be illustrated. Complications of the stereotactic procedure included one intracranial hematoma, two scalp infections requiring early removal of the electrodes and no instances of intracranial infection.
Role of Mesohepatectomy with or without Transcatheter Arterial Chemoembolization for Large Centrally Located Hepatocellular Carcinoma
Authors: Chen Xiao-ping , Hu Dao-yu , Zhang Zhi-wei , Zhang Bi-xiang , Chen Yi-fa , Zhang Wan-guang , Qiu Fa-zu
Published: May 2007

Background: The role of preoperative transcatheter arterial chemoembolization (TACE) for resectable hepatocellular carcinoma (HCC) was controversial. Methods: 246 patients with large centrally located HCC underwent mesohepatectomy (MH) and were divided into two groups: group A, 89 patients with preoperative TACE; group B, 157 patients without preoperative TACE. The aim was to evaluate the influence of preoperative TACE on postoperative complications and long-term results of patients with large centrally located HCC. Results: In the 89 patients of the TACE-MH group, a total of 123 (mean 1.4 per patient) preoperative TACEs were performed. The differences in postoperative complications (34.8 vs. 24.2%;p = 0.075) and overall hospital mortality (3.4 vs. 0.6%; p = 0.103) between the two groups were not significant. The postoperative recurrence rate in the remnant liver was higher in the MH group than in the TACE-MH group (79.6 vs. 73.0%), while the extrahepatic metastasis rate in the TACE-MH group was higher than that in the MH group (11.1 vs. 7.0%). Overall 1-, 3-, and 5-year survival rates were 87.1, 62.9, and 46.2%, respectively, for the TACE-MH group, and 82.2, 54.4, and 31.7%, respectively, for the MH group (p = 0.001); 1-, 3-, and 5-year disease-free survival rates were 75.0, 46.2, and 31.8%, respectively, for the TACE-MH group, and 69.6, 38.0, and 16.5%, respectively, for the MH group (p = 0.002). Conclusions: Long-term outcomes of patients with preoperative TACE were improved and the pattern of the recurrences after surgery was altered. The patients with large centrally located HCC could benefit more from this neoadjuvant treatment, although there was some influence of preoperative TACE on postoperative complications.
Stereotaxis of the Spinal Cord
Authors: Hitchcock E.R.
Published: May 2007

A method of stereotaxis of the spinal cord is described and the historical development of spinal stereotaxy is reviewed briefly. The importance of secure head and neck fixation and neck flexion is emphasised as important points in restricting cord mobility. The advantages of posterior and lateral approaches to the cord are mentioned. The results of stimulation and recording from the upper cervical cord have been used to construct a functional map of the cord at high cervical level.
Bmp and Fgf signaling are essential for liver specification in zebrafish
Authors: Shin Donghun , Shin Chong Hyun , Tucker Jennifer , Ober Elke A. , Rentzsch Fabian , Poss Kenneth D. , Hammerschmidt Matthias , Mullins Mary C. , Stainier Didier Y. R.
Published: May 2007

Based on data from in vitro tissue explant and ex vivo cell/bead implantation experiments, Bmp and Fgf signaling have been proposed to regulate hepatic specification. However, genetic evidence for this hypothesis has been lacking. Here, we provide in vivo genetic evidence that Bmp and Fgf signaling are essential for hepatic specification. We utilized transgenic zebrafish that overexpress dominant-negative forms of Bmp or Fgf receptors following heat-shock induction. These transgenes allow one to bypass the early embryonic requirements for Bmp and Fgf signaling, and also to completely block Bmp or Fgf signaling. We found that the expression of hhex and prox1, the earliest liver markers in zebrafish, was severely reduced in the liver region when Bmp or Fgf signaling was blocked just before hepatic specification. However, hhex and prox1 expression in adjacent endodermal and mesodermal tissues appeared unaffected by these manipulations. Additional genetic studies indicate that the endoderm maintains competence for Bmp-mediated hepatogenesis over an extended window of embryonic development. Altogether, these data provide the first genetic evidence that Bmp and Fgf signaling are essential for hepatic specification, and suggest that endodermal cells remain competent to differentiate into hepatocytes for longer than anticipated.
Different Wnt signals act through the Frizzled and RYK receptors duringDrosophilasalivary gland migration
Authors: Harris Katherine E. , Beckendorf Steven K.
Published: May 2007

Guided cell migration is necessary for the proper function and development of many tissues, one of which is the Drosophila embryonic salivary gland. Here we show that two distinct Wnt signaling pathways regulate salivary gland migration. Early in migration, the salivary gland responds to a WNT4-Frizzled signal for proper positioning within the embryo. Disruption of this signal, through mutations in Wnt4, frizzled or frizzled 2, results in misguided salivary glands that curve ventrally. Furthermore, disruption of downstream components of the canonical Wnt pathway,such as dishevelled or Tcf, also results in ventrally curved salivary glands. Analysis of a second Wnt signal, which acts through the atypical Wnt receptor Derailed, indicates a requirement for Wnt5signaling late in salivary gland migration. WNT5 is expressed in the central nervous system and acts as a repulsive signal, needed to keep the migrating salivary gland on course. The receptor for WNT5, Derailed, is expressed in the actively migrating tip of the salivary glands. In embryos mutant for derailed or Wnt5, salivary gland migration is disrupted; the tip of the gland migrates abnormally toward the central nervous system. Our results suggest that both the Wnt4-frizzled pathway and a separate Wnt5-derailed pathway are needed for proper salivary gland migration.
Repression of the hindbrain developmental program by Cdx factors is required for the specification of the vertebrate spinal cord
Authors: Skromne Isaac , Thorsen Dean , Hale Melina , Prince Victoria E. , Ho Robert K.
Published: May 2007

The spinal cord is a unique vertebrate feature that originates, together with the hindbrain, from the caudal neural plate. Whereas the hindbrain subdivides into rhombomeres, the spinal cord remains unsegmented. We have identified Cdx transcription factors as key determinants of the spinal cord region in zebrafish. Loss of Cdx1a and Cdx4 functions causes posterior expansion of the hindbrain at the expense of the unsegmented spinal cord. By contrast, cdx4 overexpression in the hindbrain impairs rhombomere segmentation and patterning and induces the expression of spinal cord-specific genes. Using cell transplantation, we demonstrate that Cdx factors function directly within the neural ectoderm to specify spinal cord. Overexpression of 5′ Hox genes fails to rescue hindbrain and spinal cord defects associated with cdx1a/cdx4 loss-of-function, suggesting a Hox-independent mechanism of spinal cord specification. In the absence of Cdx function, the caudal neural plate retains hindbrain characteristics and remains responsive to surrounding signals, particularly retinoic acid, in a manner similar to the native hindbrain. We propose that by preventing the posterior-most region of the neural plate from following a hindbrain developmental program, Cdx factors help determine the size of the prospective hindbrain and spinal cord territories.
Protein Kinase Cδ Negatively Regulates Tyrosine Hydroxylase Activity and Dopamine Synthesis by Enhancing Protein Phosphatase-2A Activity in Dopaminergic Neurons
Authors: Zhang Danhui , Kanthasamy Arthi , Yang Yongjie , Anantharam Vellareddy , Kanthasamy Anumantha
Published: May 2007

Tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine synthesis, can be regulated by phosphorylation at multiple serine residues, including serine-40. In the present study, we report a novel interaction between a key member of the novel PKC family, protein kinase Cδ (PKCδ), and TH, in which the kinase modulates dopamine synthesis by negatively regulating TH activity via protein phosphatase 2A (PP2A). We observed that PKCδ is highly expressed in nigral dopaminergic neurons and colocalizes with TH. Interestingly, suppression of PKCδ activity with the kinase inhibitor rottlerin, PKCδ-small interfering RNA, or with PKCδ dominant-negative mutant effectively increased a number of key biochemical events in the dopamine pathway, including TH-ser40 phosphorylation, TH enzymatic activity, and dopamine synthesis in neuronal cell culture models. Additionally, we found that PKCδ not only physically associates with the PP2A catalytic subunit (PP2Ac) but also phosphorylates the phosphatase to increase its activity. Notably, inhibition of PKCδ reduced the dephosphorylation activity of PP2A and thereby increased TH-ser40 phosphorylation, TH activity, and dopamine synthesis. To further validate our findings, we used the PKCδ knock-out (PKCδ −/−) mouse model. Consistent with other results, we found greater TH-ser40 phosphorylation and reduced PP2A activity in the substantia nigra of PKCδ −/− mice than in wild-type mice. Importantly, this was accompanied by an increased dopamine level in the striatum of PKCδ−/− mice. Collectively, these results suggest that PKCδ phosphorylates PP2Ac to enhance its activity and thereby reduces TH-ser40 phosphorylation and TH activity and ultimately dopamine synthesis.
Phosphatidylinositol-4,5-Bisphosphate Regulates NMDA Receptor Activity through α-Actinin
Authors: Michailidis Ioannis E. , Helton Thomas D. , Petrou Vasileios I. , Mirshahi Tooraj , Ehlers Michael D. , Logothetis Diomedes E.
Published: May 2007

Phosphatidylinositol-4,5-bisphosphate (PIP2) has been shown to regulate many ion channels, transporters, and other signaling proteins, but it is not known whether it also regulates neurotransmitter-gated channels. The NMDA receptors (NMDARs) are gated by glutamate and serve as a critical control point in synaptic function. Here we demonstrate that PIP2supports NMDAR activity. InXenopusoocytes, overexpression of phospholipase Cγ (PLCγ) or preincubation with 10 μmwortmannin markedly reduced NMDA currents. Stimulation of the epidermal growth factor receptor (EGFR) promoted the formation of an immunocomplex between PLCγ and NMDAR subunits. Stimulation of EGFR or the PLCβ-coupled M1acetylcholine receptor produced a robust transient inhibition of NMDA currents. Wortmannin application blocked the recovery of NMDA currents from the inhibition. Using mutagenesis, we identified the structural elements on NMDAR intracellular tails that transduce the receptor-mediated inhibition, which pinpoint to the binding site for the cytoskeletal protein α-actinin. Mutation of the PIP2-binding residues of α-actinin dramatically reduced NMDA currents and occluded the effect of EGF. Interestingly, EGF or wortmannin affected the interaction between NMDAR subunits and α-actinin, suggesting that this protein mediates the effect of PIP2on NMDARs. In mature hippocampal neurons, expression of the mutant α-actinin reduced NMDA currents and accelerated inactivation. We propose a model in which α-actinin supports NMDAR activity via tethering their intracellular tails to plasma membrane PIP2. Thus, our results extend the influence of PIP2to the NMDA ionotropic glutamate receptors and introduce a novel mechanism of “indirect” regulation of transmembrane protein activity by PIP2.
Lebensformen und epistemische Fähigkeiten
Authors: Kern Andrea
Published: May 2007

In der zeitgenössischen Erkenntnistheorie ist die Idee verbreitet, dass der Erwerb von Wissen davon abhängig ist, dass das Subjekt des Wissens an einer bestimmten Lebensform teilhat, die grundlegender als sein Wissen ist. Das ist eine Lesart der Position Wittgensteins, deren exemplarischer Vertreter etwa Stanley Cavell ist. Meine These dagegen lautet, dass die Lebensformtheorie einem erkenntnistheoretischen Dogma aufruht, dessen Überwindung Wittgensteins eigentliches Anliegen war: Es ist das Dogma, dass die grundlegende Bedeutung des Wissensbegriffs in der Beschreibung eines einzelnen Aktes besteht, und nicht in der Beschreibung von etwas, das auf einer logisch anderen Ebene steht: nämlich einer Fähigkeit. Damit soll nicht bestritten werden, dass die Idee einer bestimmten Lebensform wesentlich ist für die Beschreibung erkenntnisfähiger Subjekte. Doch diese ist nicht grundlegender als die Idee des Wissens selbst.
Critical Teacher Education, New Labour, and the Global Project of Neoliberal Capital
Authors: Hill Dave
Published: May 2007

The first part of this article contextualises ‘education reform’ – the restructuring of education and teacher education – within the global and national requirements and demands of Capital in the current epoch of global neoliberalism and neoconservatism. The second part analyses developments in teacher education in England and Wales under both Conservatives (1979–97) and New Labour (1997–2006) and the extent of continuities between the two. These developments have resulted in the detheorised, non-egalitarian and technicist state of teacher education in England and Wales, with its marginalisation of issues of the social contexts of education, and issues of equality/inequality. These silences work to produce teachers more fit to develop children and young adults fit for the purposes of Capital. The third part sets out a series of progressive egalitarian policy principles and proposals that constitute an egalitarian manifesto for education and for critical teacher education and critical pedagogy, very distinct from both the Conservative and New Labour policies, and calls for critical transformative egalitarian education.
Palestinian Universities and the Israeli Occupation
Authors: Hammond Keith
Published: May 2007

This article details the emergence of Palestinian universities in the 1970s in the conditions of Israeli occupation. Palestinian universities grew during the first intifada in 1986. An outline of the present controls on and around these universities is given – controls that are contrary to academic freedom and the basic right to education. Israeli actions involve arrests, violence, detention and death. In these conditions, however, academic culture still flourishes. Universities have become centres of resistance. The article details the arrest and imprisonment of several academics. Reports of routine violence only emerge when European and American academics visit Palestinian universities. This article thus urges more and more exchange visits with a view to the full details of Israel's occupation being brought out in the international community of academics.
Validity and Reliability of the Movement Ability Measure: A Self-Report Instrument Proposed for Assessing Movement Across Diagnoses and Ability Levels
Authors: Allen Diane D
Published: May 2007

Background and Purpose

Physical therapists lack instruments that assess movement across diagnoses and ability levels while focusing on physical therapy–specific outcomes. This article describes the creation of a Movement Ability Measure (MAM) and initial evidence of validity and reliability.

Subjects

More than 300 adult volunteers with various movement levels completed the 24-item questionnaire.

Methods

Item response theory methods were used to create the MAM and gather evidence of content and construct validity, test-retest and other types of reliability, and concurrent validity with the California Functional Evaluation instrument and self-acknowledgement of movement problems.

Results

The intraclass correlation coefficient for test-retest reliability was .92. Person separation reliability was .98. Correlation (r) with the California Functional Evaluation instrument was .76. Respondents who denied having movement problems perceived a significantly higher level of movement ability than those who claimed to have a little, some, or a lot of movement problems in the preceding week.

Discussion and Conclusion

The MAM shows promise for documenting perceived movement ability across ability levels and diagnoses.
Public Confidence in Criminal Justice in Canada: A Comparative and Contextual Analysis
Authors: Roberts Julian V
Published: May 2007

Public confidence in criminal justice has emerged as an important issue in most western nations. Several jurisdictions have made promoting public confidence a policy priority, and governments in many countries have recently conducted public opinion surveys to gauge levels of confidence in criminal justice. However, little is known about levels of public confidence in criminal justice in Canada. This article reviews the empirical research on this issue and attempts to explain current trends. Although a significant plurality of the public expresses little confidence in the justice system, more people are positive than are negative. In comparison to other countries, confidence levels in criminal justice are generally higher in Canada. This said, the public has less confidence in the justice system than in other public institutions such as the health care system. Consistent with findings elsewhere, the police attract most, and the prison system the least amount of public confidence. The article places these findings in context, and discusses their implications for research and policy.
Associations of osseous abnormalities in Neurofibromatosis 1
Authors: Alwan S. , Armstrong L. , Joe H. , Birch P.H. , Szudek J. , Friedman J.M.
Published: May 2007

The characteristic sites of Neurofibromatosis 1‐associated osseous manifestations are the long bones (usually the tibia and fibula), vertebrae and sphenoid wing. Although these focal bony lesions may cause profound clinical consequences, a minority of people with NF1 are affected. However, most people with NF1 are shorter than expected for their age, gender and family. The pathogenesis of NF1 focal osteopathy and its relationship, if any, to short stature are unknown. We examined associations between the occurrence of various osseous lesions in 3377 NF1 probands from the Children's Tumor Foundation NF International Database. Using logistic regression analysis among 260 NF1 probands who had undergone radiological examination of both the spine and skull, we found associations between the occurrence of sphenoid wing and long bone osteopathy (conditional odds ratio [OR] = 6.1; 95% confidence interval [CI] = 1.7–22.3; P = 0.006) and between sphenoid wing and vertebral osteopathy (OR = 16.9; 95% CI = 5.3–53.3; P < 0.001) after adjusting for age and gender. Similar findings were observed from all 3377 NF1 probands using a multivariate probit regression model. In a separate analysis, we found lower age‐ and gender‐standardized height in patients who had characteristic vertebral or sphenoid wing lesions than in people who did not (P < 0.05). We found no relationship between height and tibial osteopathy. We conclude that some people with NF1 are more likely to develop osseous manifestations than others and speculate that there may be a common pathogenetic mechanism responsible for the development of osseous abnormalities and that of the vertebrae and long bones. © 2007 Wiley‐Liss, Inc.
Morphology and properties of nanocomposites from organoclays with reduced cation exchange capacity
Authors: Chavarria F. , Nairn K. , White P. , Hill A. J. , Hunter D. L. , Paul D. R.
Published: May 2007

Organoclays with different levels of reduction in the original cation exchange capacity (CEC) were prepared to characterize the morphology and Young's modulus of their melt‐processed nanocomposites made from nylon 6 (PA‐6) and polypropylene/polypropylene grafted with maleic anhydride (PP/PP‐g‐MA). Wide‐angle X‐ray scattering (WAXS), transmission electron microscopy (TEM), and Young's modulus data are reported. Three different levels of CEC reduction were obtained; WAXS analysis and percentage loss on ignition (LOI) calculations for these organoclays showed a reduction in both the intergallery spacing and in the amount of organic modifier contained in the clay with CEC reduction. The morphology and modulus results show that these reduced‐CEC organoclays led to lower exfoliation and modulus enhancement for both PA‐6 and PP/PP‐g‐MA nanocomposites. The results may be influenced by differences in layer charge and charge distribution that could have been produced during the charge reduction process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Emission spectroscopic analysis of poly(3‐octyl thiophene) exposed to plasmas
Authors: Rodríguez‐Lazcano Y. , Martínez H.
Published: May 2007

Emission spectroscopy was employed to study reaction process of poly(3‐octyl thiophene) (P3OT) exposed to helium, nitrogen, air and hydrogen plasmas. The plasma was generated by an AC discharge at a pressure of 2 × 10−2 Pa. The discharge power was maintained at an output of 220 V and a current of 0.2 A. The light emitted was monitored in the case of each plasma. Measurements at various discharge times were made of several emission peaks. The dominant emission bands were assigned to CH2 at 589.32 nm, S2 (B3Σu−–X3Σg−) at 413.35 nm, CH+ (A1Π–X1Σ) at 422.51 nm and C3H3 at 344.02 nm. These dominant emission bands indicate that the poly(3‐octyl thiophene) was decomposed by plasma interaction. Nevertheless, the reaction between the polymer and nitrogen, hydrogen and air plasmas is more intense than that in the helium plasma. The possible reaction channels and formation mechanisms of some species produced are discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Surface‐modifiers of clay on mechanical properties of rigid polyurethane foams/organoclay nanocomposites
Authors: Xu Zhongbin , Tang Xiling , Gu Aijuan , Fang Zhengping , Tong Lifang
Published: May 2007

Three different surface modifiers, octadecyl trimethyl ammonium (ODTMA), octadecyl primary ammonium (ODPA), and decanediamine (DDA) were used to modify Na+ montmorillonite (MMT), and the resultant organoclays were coded as ODTMA‐MMT, ODPA‐MMT, DDA‐MMT, respectively. Rigid PU foams/organoclay composites were prepared by directly using organoclay as the blowing agent without the addition of water. Investigation shows that the morphology of the nanocomposites is greatly dependent on the surface modifiers of clay used in the composites. In detail, DDA‐MMT is partially exfoliated in the PU matrix with the smallest cell size, while two others are intercalated in the PU matrices with smaller cell sizes. The sequence of their cell sizes is pristine PU foams > rigid PU foams/ODTMA‐MMT > rigid PU foams/ODPA‐MMT > rigid PU foams/DDA‐MMT, and the average cell size of rigid PU foams/DDA‐MMT composites decreases evidently from 0.30 to 0.07 mm. Moreover, all rigid PU foams/organoclay composites show remarkable enhanced compressive and tensile strengths as well as dynamic properties than those of PU foams, and the enhancement degree coincides well with the relative extent of internal hydrogen bonding of materials and gallery spacing of organoclay. For example, in the case of rigid PU foams/DDA‐MMT composite, 214% increase in compressive strength and 148% increase in tensile strength compared with those of pure PU foams were observed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Mutational activation of ErbB family receptor tyrosine kinases: insights into mechanisms of signal transduction and tumorigenesis
Authors: Riese David J. , Gallo Richard M. , Settleman Jeffrey
Published: May 2007

Signaling by the Epidermal Growth Factor Receptor (EGFR) and related ErbB family receptor tyrosine kinases can be deregulated in human malignancies as the result of mutations in the genes that encode these receptors. The recent identification of EGFR mutations that correlate with sensitivity and resistance to EGFR tyrosine kinase inhibitors in lung and colon tumors has renewed interest in such activating mutations. Here we review current models for ligand stimulation of receptor dimerization and for activation of receptor signaling by receptor dimerization. In the context of these models, we discuss ErbB receptor mutations that affect ligand binding and those that cause constitutive receptor phosphorylation and signaling as a result of constitutive receptor dimerization. We discuss mutations in the cytoplasmic regions that affect enzymatic activity, substrate specificity and coupling to effectors and downstream signaling pathways. Finally, we discuss how emergent mechanisms of ErbB receptor mutational activation could impact the search for clinically relevant ErbB receptor mutations. BioEssays 29:558–565, 2007. © 2007 Wiley Periodicals, Inc.