bluuebunny/crossref_metadata_2025 huggingface dataset:
Stem cell and kinase activity‐independent pathway in resistance of leukaemia to BCR‐ABL kinase inhibitors
Authors: Li Shaoguang , Li Dongguang
Published: March 2009

Introduction

Ph+ leukaemia

Leukaemic stem cells

Identification of CML stem cells in mice

BCR‐ABL kinase inhibitors do not completely eradicate CML stem cells

B‐ALL stem cells and their sensitivity to kinase inhibitors

SRC kinase may impact B‐ALL stem cell functions through activation of the downstream signalling molecule β‐catenin

Activation of SRC kinases by BCR‐ABL is independent of its kinase activity

Role of SRC kinases in the development of B‐ALL

Inhibition BCR‐ABL kinase activity and SRC kinase leads to long‐term survival of B‐ALL mice

Role of SRC kinases in progression of CML to lymphoid blast crisis

Comments and conclusions

BCR‐ABL tyrosine kinase inhibitors, such as imatinib (Gleevec) are highly effective in treating human Philadelphia chromosome‐positive (Ph+) chronic myeloid leukaemia (CML) in chronic phase but not in terminal acute phase; acquired drug resistance caused mainly by the development of BCR‐ABL kinase domain mutations prevents cure of the leukaemia. In addition, imatinib is ineffective in treating Ph+ B‐cell acute lymphoblastic leukaemia (B‐ALL) and CML blast crisis, even in the absence of the kinase domain mutations. This type of drug resistance that is unrelated to BCR‐ABL kinase domain mutations is caused by the insensitivity of leukaemic stem cells to kinase inhibitors such as imatinib and dasatinib, and by activation of a newly‐identified signalling pathway involving SRC kinases that are independent of BCR‐ABL kinase activity for activation. This SRC pathway is essential for leukaemic cells to survive imatinib treatment and for CML transition to lymphoid blast crisis. Apart from BCR‐ABL and SRC kinases, stem cell pathways must also be targeted for curative therapy of Ph+ leukaemia.
Prevalence and extent of dental caries, dental fluorosis, and developmental enamel defects in Lithuanian teenage populations with different fluoride exposures
Authors: Machiulskiene Vita , Baelum Vibeke , Fejerskov Ole , Nyvad Bente
Published: March 2009

The aim of this study was to describe the pattern of dental caries, dental fluorosis, and developmental defects of non‐fluoride origin in Lithuanian children born and raised in regions with 1.1 ppm (1.1 mg/l F) and 0.3 ppm (0.3 mg/l F) water fluoride levels, respectively. All permanent surfaces/teeth of 300 teenagers were examined for dental caries, dental fluorosis, and non‐fluoride developmental defects. The caries prevalence of the study population was 100%. The mean number of decayed surfaces (DS) differed only slightly and statistically insignificantly between the ‘1.1 ppm fluoride’ and ‘0.3 ppm fluoride’ groups (19.6 and 18.1, respectively). However, a greater number of inactive lesions and fewer fillings were found in the ‘1.1 ppm fluoride’ group than in the ‘0.3 ppm fluoride’ group (mean difference 1.18 and −2.80, respectively). The prevalence of dental fluorosis was 45% and 21%, respectively; the prevalence of non‐fluoride opacities was 8% and 19%, respectively; and the prevalence of hypoplasia was 12% and 16%, respectively, in the ‘1.1 ppm fluoride’ and ‘0.3 ppm fluoride’ groups. Higher caries levels were noted in children with no fluorosis compared to those with fluorosis recorded (mean DS difference, 3.43). The results lend support to the hypothesis that the presence of fluoride in the oral environment promotes lesion arrest rather than inhibiting the initiation of new lesions.
The location and characteristics of two populations of dental pulp cells affect tooth development
Authors: Sumita Yoshinori , Tsuchiya Shuhei , Asahina Izumi , Kagami Hideaki , Honda Masaki J.
Published: March 2009

This study investigated the characteristics of two dental pulp cell populations during the early stages of crown formation in porcine teeth. A transplantation method was developed to reproduce epithelial cell–mesenchymal cell interactions during odontogenesis (tooth development). The technique allowed two types of cells/tissue to be combined in vivo. Populations of cells localized in the cervical loop epithelium region, dental pulp horn, and dental pulp core chambers were isolated and dissociated into single cells. Each population was examined for its gene‐expression pattern using both semiquantitative and quantitative reverse transcription–polymerase chain reaction (RT‐PCR) analyses, and for its tissue‐formation capability by combining the cervical loop epithelial cells with either pulp horn cells or pulp core cells on biodegradable collagen scaffolds that were subsequently examined using histology and immunohistology. Gene‐expression patterns showed that pulp horn cells were more mature than pulp core cells. Cervical loop epithelial cells combined with pulp horn cells mainly reconstituted dentin–cementum structures. By contrast, cervical loop epithelial cells combined with pulp core cells reconstituted enamel–dentin structures. These results suggest that mesenchymal cells residing in a specific location of the pulp possess a specific tissue‐formation potential when combined with epithelial cells.
Differential gene expression profiling of the molar tooth germ in peroxisome proliferator‐activated receptor‐α (PPAR‐α) knockout mouse and in wild‐type mouse: molar tooth phenotype of PPAR‐α knockout mouse
Authors: Sehic Amer , Khuu Cuong , Risnes Steinar , Osmundsen Harald
Published: March 2009

Gene expression profiling of the first molar tooth germ at embryonic days (E)17.5 and 18.5, and at postnatal days (P)0, 2, and 6 from peroxisome proliferator‐activated receptor‐α (PPAR‐α) knockout mouse and from wild‐type mouse was carried out using microarrays and validated using real‐time reverse transcription–polymerase chain reaction (RT‐PCR) and western blotting. When comparing expression profiles at each time‐point, a total of 1,235 genes showed significantly different expression, 772 of which exhibited significantly decreased expression in tooth germ from knockout mouse. With genes exhibiting significantly decreased levels of expression in tooth germ from PPAR‐α knockout mouse, bioinformatic analysis using ingenuity pathway analysis yielded significant associations to cellular functions related to cellular growth/proliferation and to networks related to regulation of calcium homeostasis. Using scanning electron microscopy to investigate molars from adult PPAR‐α knockout mouse, the molar size was found to be slightly reduced, the enamel structure was found to be normal, but cervical molar enamel exhibited evidence suggesting hypomineralization. Although the PPAR‐α knockout had no significant effect on molar morphology, the results suggest that active PPAR‐α signaling is required to achieve normal mineralization of molar enamel, most probably through regulation of calcium homeostasis and metabolism of vitamin D. Cyp27b1 was expressed in tooth germ, suggesting that tooth germ can synthesize active vitamin D. Expression of Cyp27b1 was significantly enhanced in postnatal PPAR‐α knockout tooth germ.
Prevalence of oral pathologic findings in an ancient pre‐Columbian archeologic site in the Atacama Desert
Authors: Meller C , Urzua I , Moncada G , Von Ohle C
Published: March 2009

Objective:  To determine the prevalence of oral pathologic findings in an ancient culture that inhabited the Atacama Desert.

Materials and methods:  A systematic examination was performed on the remains of 83 individuals unearthed from a prehistoric burial ground. A total of 57 skeletal remains achieved appropriate inclusion criteria, from which estimated age at death, gender, ante‐ and postmortem tooth loss, prevalence and location of caries, apical periodontitis sequela, alveolar bone resorption and attrition were recorded.

Results:  From the analyzed skeletal remains (13 male, 22 female and 22 not identifiable), the mean age estimated was 29.9 ± 13.8 years. A total of 89.4% of them presented permanent dentition with a mean ante‐mortem tooth loss of 9.0 teeth and a postmortem mean tooth loss of 14.4 teeth per subject. In all, 46.4% of the postmortem remaining permanent teeth (n = 237) showed caries lesions. Interproximal caries was most frequently observed (31.5%), followed by occlusal (25.9%) and cervical caries (19.4%). Root remnants were found in 23.1% of the cases. In addition, 58.0% of the adults presented attrition, 26.0% signs of apical periodontitis and 44.0% loss of alveolar bone support >5 mm.

Conclusion:  The remains of jaws and teeth of the individuals examined in this study presented sequelae of severe oral health damage due to caries and periodontal disease.
Influence of land‐use types and climatic variables on seasonal patterns of NDVI in Mediterranean Iberian ecosystems
Authors: Durante P. , Oyonarte C. , Valladares F.
Published: March 2009

Question: What is the influence of management on the functioning of vegetation over time in Mediterranean ecosystems under different climate conditions?

Location: Mediterranean shrublands and forests in SE Iberia (Andalusia).

Methods: We evaluated the Normalized Difference Vegetation Index (NDVI) for the 1997‐2002 time series to determine phenological vegetation patterns under different historical management regimes. Three altitudinal ranges were considered within each area to explore climate × management interactions. Each phenological pattern was analysed using time series statistics, together with precipitation (monthly and cumulative) and temperature.

Results: NDVI time series were significantly different under different management regimes, particularly in highly transformed areas, which showed the lowest NDVI, weakest annual seasonality and a more immediate phenological response to precipitation. The NDVI relationship with precipitation was strongest in the summer‐autumn period, when precipitation is the main plant growth‐limiting factor.

Conclusions: NDVI time series analyses elucidated complex influences of land use and climate on ecosystem functioning in these Mediterranean ecosystems. We demonstrated that NDVI time series analyses are a useful tool for monitoring programmes because of their sensitivity to changes, ease of use and applicability to large‐scale studies.
Recovery of sandy beach and maritime forest vegetation on Phuket Island (Thailand) after the major Indian Ocean tsunami of 2004
Authors: Hayasaka D. , Fujiwara K. , Box E.O.
Published: March 2009

Question: How rapidly has the sandy beach and maritime forest vegetation on Phuket recovered and regenerated after the impact of the major Indian Ocean tsunami of 2004? What are the characteristics of sandy beach species for regenerating their populations and the invasion patterns of originally non‐sandy beach species or other newcomers after the tsunami?

Location: Phuket Island, southern Thailand.

Methods: Species composition of beaches was studied on the same research plots 6 months before and 9 months after the tsunami. The changes in individual species cover before and after the tsunami were determined by χ2 tests. Change in community composition was analysed by detrended correspondence analysis. The relationship between species and environmental factors was analysed by canonical correspondence analysis.

Results: The sites disturbed by the tsunami were often invaded by annuals, especially grasses and asteraceous plants, rather than by perennials. In contrast, species with clonal growth by stolons decreased significantly. Factors determining the species habitat differences were soil hardness (penetration resistance of sandy soil), per cent silt content, soil water content and beach management. Habitat differences among originally non‐sandy beach herbaceous species that expanded their population or moved to the coast after the disaster were defined by sand accretion or erosion caused by the tsunami. Many sandy beach herbaceous communities changed into Dactyloctenium aegyptium communities because of the tsunami were originally constituted by non‐sandy beach D. aegyptium with Cenchrus echinatus. Although the forest floors of most maritime forests were invaded by originally non‐sandy beach Tridax procumbens, Eleusine indica or D. aegyptium because of the tsunami, this did not result in a change in the vegetation unit, because species' loss was restricted to the understorey. In time, these forests will recover their previous community composition.

Conclusions: Our results suggest that originally non‐sandy beach native species invaded the disturbed beaches rapidly after the tsunami but their habitats differ. Sites where sand accumulated on a beach because of the tsunami were invaded by D. aegyptium and E. indica, whereas soil erosion permitted invasion by Digitania adscendens. Tridax procumbens establishes rapidly on wet sites with hard soil, high per cent silt content and low beach management pressure. Sandy beach species with subterranean long rhizomes are strongly tolerant of such disasters. We concluded that the species composition of the beaches disturbed by a temporary large disaster is determined by dormancy and growth forms, with radicoid form being influential.
Reaction mechanisms of thiamin diphosphate enzymes: new insights into the role of a conserved glutamate residue
Authors: Shaanan Boaz , Chipman David M.
Published: March 2009

Subsequent to the demonstration in the late 1950s of the catalytic power of the C2 anion/ylid of thiamin diphosphate, further convincing evidence was provided demonstrating that the 4′‐aminopyrimidine group plays a vital role in activation of this cofactor. Structural evidence from several crystal structures of thiamin diphosphate‐dependent enzymes emphasized the presence of a glutamate residue in hydrogen‐bonding distance from N1′ as a conserved element in these enzymes. The important role of this conserved glutamate in promoting C2‐H ionization and activation of thiamin diphosphate was emphasized by site‐directed mutagenesis studies. This role was further elaborated by spectroscopic studies of the 4′‐aminopyrimidine–iminopyrimidine tautomerization. The low polarity of the environment of the protein‐bound thiazolium is an additional factor in the stabilization of the C2 anion/ylid. The recently determined crystal structure and mutagenesis studies of glyoxylate carboligase, in which the position of the conserved glutamate is occupied by valine, now show that, for the multi‐step reaction catalyzed by this enzyme, the advantages of accelerating the ionization of C2‐H by re‐introducing a carboxylate are outweighed by the apparent overstabilization of intermediates.
Reaction mechanisms of thiamin diphosphate enzymes: redox reactions
Authors: Tittmann Kai
Published: March 2009

Amongst a wide variety of different biochemical reactions in cellular carbon metabolism, thiamin diphosphate‐dependent enzymes catalyze the oxidative decarboxylation of 2‐keto acids. This type of reaction typically involves redox coupled acyl transfer to CoA or phosphate and is mediated by additional cofactors, such as flavins, iron‐sulfur clusters or lipoamide swinging arms, which transmit the reducing equivalents that arise during keto acid oxidation to a final electron acceptor. EPR spectroscopic and kinetic studies have implicated the intermediacy of radical cofactor intermediates in pyruvate:ferredoxin oxidoreductase and an acetyl phosphate‐producing pyruvate oxidase, whereas the occurrence of transient on‐pathway radicals in other enzymes is less clear. The structures of pyruvate:ferredoxin oxidoreductase and pyruvate oxidase with different enzymic reaction intermediates along the pathway including a radical intermediate were determined by cryo‐crystallography and used to infer electron tunneling pathways and the potential roles of CoA and phosphate for an intimate coupling of electron and acyl group transfer. Viable mechanisms of reductive acetylation in pyruvate dehydrogenase multi‐enzyme complex, and of electron transfer in the peripheral membrane enzyme pyruvate oxidase from Escherichia coli, are also discussed.
The chitinolytic system of Lactococcus lactis ssp. lactis comprises a nonprocessive chitinase and a chitin‐binding protein that promotes the degradation of α‐ and β‐chitin
Authors: Vaaje‐Kolstad Gustav , Bunæs Anne C. , Mathiesen Geir , Eijsink Vincent G. H.
Published: March 2009

It has recently been shown that the Gram‐negative bacterium Serratia marcescens produces an accessory nonhydrolytic chitin‐binding protein that acts in synergy with chitinases. This provided the first example of the production of dedicated helper proteins for the turnover of recalcitrant polysaccharides. Chitin‐binding proteins belong to family 33 of the carbohydrate‐binding modules, and genes putatively encoding these proteins occur in many microorganisms. To obtain an impression of the functional conservation of these proteins, we studied the chitinolytic system of the Gram‐positive Lactococcus lactis ssp. lactis IL1403. The genome of this lactic acid bacterium harbours a simple chitinolytic machinery, consisting of one family 18 chitinase (named LlChi18A), one family 33 chitin‐binding protein (named LlCBP33A) and one family 20 N‐acetylhexosaminidase. We cloned, overexpressed and characterized LlChi18A and LlCBP33A. Sequence alignments and structural modelling indicated that LlChi18A has a shallow substrate‐binding groove characteristic of nonprocessive endochitinases. Enzymology showed that LlChi18A was able to hydrolyse both chitin oligomers and artificial substrates, with no sign of processivity. Although the chitin‐binding protein from S. marcescens only bound to β‐chitin, LlCBP33A was found to bind to both α‐ and β‐chitin. LlCBP33A increased the hydrolytic efficiency of LlChi18A to both α‐ and β‐chitin. These results show the general importance of chitin‐binding proteins in chitin turnover, and provide the first example of a family 33 chitin‐binding protein that increases chitinase efficiency towards α‐chitin.
Prediction of Indoor Air Quality from Soil‐Gas Data at Industrial Buildings
Authors: Eklund Bart , Burrows Don
Published: March 2009

Subslab or shallow soil‐gas data are often compared with indoor air concentration data in vapor intrusion (VI) evaluations. If no indoor air data are available or confounding sources are present, or if future scenarios are considered, the soil‐gas data may be used to estimate the indoor air concentrations due to VI. The typical approach in risk assessments is to use the 95th percentile values from a set of concentration data. For VI studies, however, this rarely is an option because the data sets tend to be quite small. Therefore, various guidance documents urge the use of maximum soil‐gas values. This may be reasonable for small residential buildings, but can lead to very conservatively biased estimates if applied to large industrial buildings with localized areas of contamination, especially given that the sampling locations may not be randomly selected and instead are biased toward worst‐case locations. By this approach, VI guidance implicitly tolerates a large percentage of false positive decision errors to minimize the number of false negative decision errors. In this paper, implications of using maximum values are discussed and illustrated with data sets from a number of large industrial buildings at various sites. An alternative approach to using maximum soil‐gas values is proposed that serves to reduce the number of false positive results while controlling the number of false negatives to an acceptable level.
Taxonomic review of the tribes Trachyscelini and Phaleriini (Coleoptera: Tenebrionidae) from Korean coastal dunes
Authors: JUNG Boo Hee , PARK Hae Chul , KIM Jin Ill
Published: March 2009

A taxonomic review of the sabulous tenebrionid species belonging to the tribes Trachyscelini and Phaleriini from Korean coastal dunes is presented. Six species in five genera were recognized: Phaleromela subhumeralis (Marseul, 1876), Micropedinus algae Lewis, 1894, Micropedinus pallidipennis Lewis, 1894, Emypsara riederi (Faldermann, 1833) and Trachyscelis sabuleti Lewis, 1894, as well as one new record, Phaleria atriceps (Lewis, 1894), in Korea. A key, description, habitus photographs of adults and line drawings of the aedeagus are provided with biological notes.
Beauveria bassiana infection of eggs of stored‐product beetles
Authors: LORD Jeffrey C.
Published: March 2009

Beauveria bassiana (Balsamo) Vuillemin was tested under maximum challenge conditions with an estimated dose of 1.1 × 105 conidia/mm2 for its effects on eggs of four of the major beetle pests of stored grain and grain products. When ambient relative humidity (RH) was 92%, hatch of fungus‐treated Rhyzopertha dominica (Fabricius) eggs was 13% versus 58% for control eggs, and hatch of treated Tribolium castaneum (Herbst) was 17% versus 51% for controls. There was no fungus effect at RH of 48 and 73%. Fungus treatment of Cryptolestes ferrugineus (Stephens) and Oryzaephilus surinamensis (Linnaeus) eggs had no effect. Sectioned T. castaneum eggs demonstrated that the fungus penetrates and infects them.
The Use of Midodrine in Patients With Advanced Heart Failure
Authors: Zakir Ramzan M. , Folefack Alain , Saric Muhamed , Berkowitz Robert L.
Published: March 2009

In many patients, the treatment of heart failure (HF) cannot be optimized because of pre‐existing or treatment‐induced hypotension. Midodrine, a peripheral α1‐adrenergic agonist may allow for up‐titration of neurohormonal antagonist therapy leading to improved outcomes. Ten consecutive patients with HF due to systolic dysfunction and symptomatic hypotension interfering with optimal medical therapy were started on midodrine. After a 6‐month follow‐up, a higher percentage of patients were on optimal HF therapy (angiotensin‐converting enzyme inhibitor/angiotensin receptor blocker mg % of optimal dose 20% vs 57.5%; P<.001) (β‐blockers mg % optimal dose 37.5% vs 75%; P<.001) (spironolactone/eplerenone mg % 43.7% vs 95%; P<.001). This led to an improvement in left ventricular ejection fraction (baseline 24±9.4 vs 32.2±9.9; P<.001) and clinical outcomes, with a significant reduction in total hospital admissions (32 vs 12; P=.02) and total hospital days (150 vs 58; P=.02).
Association of TBX21 T‐1993C polymorphism with viral persistence but not disease progression in hepatitis B virus carriers
Authors: Chen Song , Zhao Wenli , Tan Wenting , Xu Baoyan , Dan Yunjie , Mao Qing , Kuang Xuemei , Wang Yuming , Deng Guohong
Published: March 2009

Aim:  Transcription factor T‐bet is responsible for the differentiation of naive T lymphocytes, and its expression level is linked with different responses to some viral infections, including hepatitis B virus (HBV) infection. In this report we examine whether promoter polymorphisms of the TBX21 gene (encoding T‐bet) are associated with susceptibility to HBV persistence or disease progression in chronic HBV carriers.

Methods:  Three previously reported promoter polymorphisms, T‐1993C, T‐1514C and G‐1499A, were analyzed by polymerase chain reaction restriction fragment length polymorphism analysis. Two common polymorphisms, T‐1993C and T‐1514C, were selected for genotyping in 1074 chronic HBV carriers, 310 spontaneously recovered controls and 374 HBV naive controls. Of 1074 HBV carriers, 234 were considered to be asymptomatic carriers and 840 were found to have chronic progressive liver disease including cirrhosis and hepatocellular carcinoma. Haplotypes were constructed for each subject and associations with the susceptibility to persistent HBV infection were estimated by logistic regression.

Results:  The –1993C allele in the TBX21 promoter was significantly more common among chronic HBV carriers compared with recovered controls (χ2 = 6.65, P = 0.01). In contrast, the frequency of TT haplotype at positions –1993/–1514, was significantly higher in recovered controls than chronic HBV carriers (P = 0.0027, odds ratio = 1.57; 95% confidence interval, 1.16–2.12). In HBV carriers, the TBX21 promoter polymorphisms were not linked to disease progression.

Conclusion:  The TBX21 promoter polymorphisms do not appear to be determinant of disease progression in Chinese HBV carriers. The T‐1993C polymorphism in the TBX21 promoter influences susceptibility to persistent HBV infection.
The principle of relativity and inertial dragging
Authors: Grøn Øyvind G.
Published: March 2009

Mach’s principle and the principle of relativity have been discussed by Hartman and Nissim-Sabat. Several phenomena were said to violate the principle of relativity as applied to rotating motion. These claims have recently been contested by Bhadra and Das. However, neither set of authors allowed for the general relativistic phenomenon of inertial dragging, and no calculation was offered to substantiate their claims. I discuss the possible validity of the principle of relativity for rotating motion within the context of the general theory of relativity and discuss the significance of inertial dragging in this connection. Although my main points are of a qualitative nature, I also provide the necessary calculations to demonstrate how these points arise as consequences of the general theory of relativity.
Resource Letter BH-2: Black Holes
Authors: Gallo Elena , Marolf Donald
Published: March 2009

This Resource Letter is designed to guide students, educators, and researchers through (some of) the literature on black holes. We discuss both the physics and astrophysics of black holes. We emphasize breadth over depth, and review articles over primary sources. We include resources ranging from nontechnical discussions appropriate for broad audiences to technical reviews of current research. Topics addressed include classification of stationary solutions, perturbations and stability of black holes, numerical simulations, collisions, the production of gravity waves, black-hole thermodynamics and Hawking radiation, quantum treatments of black holes, black holes in both higher and lower dimensions, and connections to nuclear and condensed-matter physics. On the astronomical end, we also cover the physics of gas accretion onto black holes, relativistic jets, gravitationally redshifted emission lines, evidence for stellar-mass black holes in binary systems and supermassive black holes at the centers of galaxies, the quest for intermediate-mass black holes, the assembly and merging history of supermassive black holes through cosmic time, and their affects on the evolution of galaxies.
A national study assessing the teaching and learning of introductory astronomy. Part I. The effect of interactive instruction
Authors: Prather Edward E. , Rudolph Alexander L. , Brissenden Gina , Schlingman Wayne M.
Published: March 2009

We present the results of a national study on the teaching and learning of astronomy as taught in general education, non-science-major, introductory astronomy courses. Nearly 4000 students enrolled in 69 sections of courses taught by 36 different instructors at 31 institutions completed (pre- and post-instruction) the Light and Spectroscopy Concept Inventory (LSCI) from Fall 2006 to Fall 2007. The classes varied in size and were from all types of institutions, including 2- and 4-year colleges and universities. Normalized gain scores for each class were calculated. Pre-instruction LSCI scores were clustered around ∼25%, independent of class size and institution type, and normalized gain scores varied from about −0.07 to 0.50. To estimate the fraction of classroom time spent on learner-centered, active-engagement instruction we developed and administered an Interactivity Assessment Instrument (IAI). Our results suggest that the differences in gains were due to instruction in the classroom, not the type of class or institution. We also found that higher interactivity classes had the highest gains, confirming that interactive learning strategies are capable of increasing student conceptual understanding. However, the wide range of gain scores seen for both lower and higher interactivity classes suggests that the use of interactive learning strategies is not sufficient by itself to achieve high student gain.
Making a Simple Self-Starting Electric Motor
Authors: Hong Seok-In , Choi Jung-In , Hong Seok-Cheol
Published: March 2009

A simple electric motor1 has a problem in that the current applied to the motor per se can rarely trigger its rotation. Usually such motors begin to rotate after the rotor is slightly turned by hand (i.e., manual starting). In a self-starting motor, the rotor starts to rotate spontaneously as soon as the current is applied. This paper describes the initial condition of the rotor required for self-starting.
Using a Classroom Response System to Improve Multiple-Choice Performance in AP® Physics
Authors: Bertrand Peggy
Published: March 2009

Participation in rigorous high school courses such as Advanced Placement (AP®) Physics increases the likelihood of college success, especially for students who are traditionally underserved.1 Tackling difficult multiple-choice exams should be part of any AP program because well-constructed multiple-choice questions, such as those on AP exams and on the Force Concept Inventory,2 are particularly good at rooting out common and persisting student misconceptions. Additionally, there are barriers to multiple-choice performance that have little to do with content mastery. For example, a student might fail to read the question thoroughly, forget to apply a reasonableness test to the answer, or simply work too slowly.
An MBL Experiment to Analyze the Torque on a Rigid Body
Authors: Gianino Concetto
Published: March 2009

Torque is a physical quantity defined as the cross product: τ = r × F, where F is the applied force to a rigid body at a point a distance r from the rotation axis. The torque is a vector having direction given by the usual right-hand rule and a magnitude τ = rF sin θ, θ being the angle between r and F.1
Teaching Special Relativity Without Calculus
Authors: Ruby Lawrence
Published: March 2009

I 2007 many AAPT members received a booklet that is the first chapter of a physics textbook1 available on a CD. This book espouses the new educational philosophy of teaching special relativity as the first item in the topic of mechanics. Traditionally, special relativity is part of one or more modern physics chapters at the end of the text,2 and very often this material is never utilized due to time constraints. From a logical standpoint, special relativity is important in satellite communications and in cosmology, as well as in modern physics applications such as atomic theory and high-energy physics. The purpose of this paper is to show that the new philosophy can be carried out in a noncalculus physics course, by demonstrating that all of the principal results of special relativity theory can be obtained by simple algebra. To accomplish this, we shall propose alternate derivations for two results that are usually obtained with calculus. Textbooks2 typically obtain the equations for time dilation and for length contraction from simple considerations based on Einstein's second postulate.3 We shall start from this point.
EXACT KNOWLEDGE HIDING IN TRANSACTIONAL DATABASES
Authors: GKOULALAS-DIVANIS ARIS , VERYKIOS VASSILIOS S.
Published: March 2009

The hiding of sensitive knowledge in the form of frequent itemsets, has gained increasing attention over the past years. This paper highlights the process of border revision, which is essential for the identification of hiding solutions bearing no side-effects, and provides efficient algorithms for the computation of the revised positive and the revised negative borders. By utilizing border revision, we unify the theory behind two exact hiding algorithms that guarantee optimal solutions both in terms of database distortion and side-effects introduced by the hiding process. Following that, we propose a novel extension to one of the hiding algorithms that allows it to identify exact hiding solutions to a much wider range of problems (than its original counterpart). Through experimentation, we compare the exact hiding schemes against two state-of-the-art heuristic algorithms and demonstrate their ability to consistently provide solutions of higher quality to a wide variety of hiding problems.
A Solution Approach from an Analytic Model to Heuristic Algorithm for Special Case of Vehicle Routing Problem with Stochastic Demands
Authors: İşleyen Selçuk K. , Baykoç Ö. Faruk
Published: March 2009

We define a special case for the vehicle routing problem with stochastic
demands (SC‐VRPSD) where customer demands are normally distributed. We propose a new
linear model for computing the expected length of a tour in SC‐VRPSD. The proposed model
is based on the integration of the “Traveling Salesman Problem” (TSP) and the Assignment Problem. For large‐scale problems, we also use an Iterated Local Search (ILS) algorithm in order to reach an effective solution.
Advanced Secure Information Retrieval Technology for Multilayer Information Extraction
Authors: Chang Shoude , Yu Kui , Liu Jiaren
Published: March 2009

Secure information retrieval technology aims at status identification and documentation authentication. Ideally, materials or devices used in these technologies should be hard to find, difficult to counterfeit, and as simple as possible. This manuscript addresses a novel information retrieval technology, with photoluminescent (PL) semiconductor quantum dots (QDs) synthesized via wet chemistry approaches used as its coding materials. Conceptually, these QDs are designed to exhibit emission at Fraunhofer line positions, namely, black lines in the solar spectrum; thus, the retrieval system can extract useful information under sunshine covering areas. Furthermore, multiphoton excitation (MPE) technology enables the retrieval system to be multilayer information extraction, with thin films consisting of QDs applied to various substrates, such as military helmets and vehicle and fingernails. Anticipated applications include security, military, and law enforcement. QD‐based security information can be easily destroyed by preset expiration in the presence of timing agents.
EMMPRIN (CD147) is a novel receptor for platelet GPVI and mediates platelet rolling via GPVI-EMMPRIN interaction
Authors: Seizer Peter , Borst Oliver , Langer Harald , Bültmann Andreas , Münch Götz , Herouy Yared , Stellos Konstantinos , Krämer Björn , Bigalke Boris , Büchele Berthold , Bachem Max , Vestweber Dietmar , Simmet Thomas , Gawaz Meinrad , May Andreas
Published: March 2009

The Extracellular Matrix Metalloproteinase Inducer (EMMPRIN, CD147, basigin) is an immunoglobulin-like receptor expressed in various cell types. During cellular interactions homotypic EMMPRIN-EMMPRIN interactions are known to induce the synthesis of matrix metalloproteinases. Recently, we have identified EMMPRIN as a novel receptor on platelets. To our knowledge EMMPRIN has not been shown to serve as adhesion receptor, yet. Here we characterise platelet glycoprotein VI (GPVI) as a novel adhesion receptor for EMMPRIN. Human platelets were prestimulated with ADP and perfused over immobilised recombinant EMMPRIN-Fc or Fc-fragments under arterial shear conditions. ADP-stimulated platelets showed significantly enhanced rolling (but not enhanced firm adhesion) on immobilised EMMPRIN-Fc compared to Fc. Pretreatment of platelets with blocking mAbs anti-EMMPRIN or anti-GPVI leads to a significant reduction of rolling platelets on immobilised EMMPRIN-Fc, whereas pretreatment with blocking mAbs anti-p-selectin, anti-α4-integrin or anti-GPIIb/IIIa complex (20 μg/ml each) had no effect. Consistently, chinese hamster ovary (CHO) cells stably transfected with GPVI showed enhanced rolling (but not adhesion) on immobilised EMMPRIN-Fc in comparison to nontransfected CHO cells. Similarly, CHO cells stably transfected with EMMPRIN showed enhanced rolling on immobilised GPVIFc (or EMMPRIN-Fc) compared to non transfected CHO-cells. Finally, specific binding of EMMPRIN to GPVI was demonstrated by a modified ELISA and surface plasmon resonance technology with a dissociation constant of 88 nM. Platelet GPVI is a novel receptor for EMMPRIN and can mediate platelet rolling via GPVIEMMPRIN interaction.
Procoagulant activity and phosphatidylserine of amniotic fluid cells
Authors: Liu Shuchuan , Ma Ming , Hou Jinxiao , Yu Hongjuan , Lu Chengfang , Gilbert Gary , Zhou Jin , Shi Jialan
Published: March 2009

Amniotic fluid (AF) may induce disseminated intravascular coagulation (DIC) when it enters maternal circulation by breaching the placental-maternal circulation barrier. The precise mechanism of the procoagulant activity of AF is unclear, but tissue factor (TF) has been proposed to be the main cause. As one constituent of AF, AF cells accumulate and undergo apoptosis continuously. Therefore, we speculate that AF cells have procoagulant activity due to the externalisation of phosphatidylserine (PS). The present study aims to demonstrate that, in addition to TF, the PS that is externalised on AF cells is important for the procoagulant activity of AF. Ten AF samples from parturient women were analysed using lactadherin as the probe for PS. Anti-TF antibody also was used to identify TF and its associated coagulation functions in AF cells. Normal platelets, neutrophils, and lymphocytes were harvested as controls. Confocal microscopy and flow cytometry was used to assess PS expression on AF cells. The procoagulant activity of AF cells was demonstrated by a plasma coagulation assay and further confirmed by factor Xase/prothrombinase assays. PS and TF were present on most AF cells, providing substantial procoagulant activity. Furthermore, factor Xase and prothrombinase assays showed that AF cells substantially enforced the activation of factor X and prothrombin. PS on AF cells is an important procoagulant source for AF. Lactadherin is an ideal anticoagulant for inhibiting the procoagulant activity of AF cells.
Impact of proton pump inhibitors on the antiplatelet effects of clopidogrel
Authors: Morath Tanja , Stegherr Julia , Braun Siegmund , Vogt Wolfgang , Hadamitzky Martin , Schömig Albert , Kastrati Adnan , Beckerath Nicolas von , Sibbing Dirk
Published: March 2009

Patients receiving dual antiplatelet treatment with aspirin and clopidogrel are commonly treated with proton pump inhibitors (PPIs). Attenuating effects on platelet response to clopidogrel have been reported solely for the PPI omeprazole. PPIs differ in their metabolisation properties as well as their potential for drug-drug interactions. The aim of this study was to investigate the impact of different PPIs (pantoprazole, omeprazole, esomeprazole) on platelet response to clopidogrel in patients with previous coronary stent placement under chronic clopidogrel treatment. In a cross-sectional observational study, consecutive patients under clopidogrel maintenance treatment (n=1,000) scheduled for a control coronary angiography were enrolled. Adenosine diphosphate (ADP)-induced platelet aggregation (in AU*min) was measured with multiple electrode platelet aggregometry (MEA). From the entire study population, 268 (26.8%) patients were under PPI treatment at the time point of platelet function testing (pantoprazole, n=162; omeprazole, n=64; esomeprazole, n=42). Platelet aggregation (median [interquar-tile range]) was significantly higher in patients with omeprazole treatment (295.5 [193.5–571.2] AU*min) compared to patients without PPI treatment (220.0 [143.8–388.8] AU*min; p=0.001). Platelet aggregation was similar in patients with pantoprazole (226.0 [150.0–401.5] AU*min) or esomeprazole (209.0 [134.8–384.8] AU*min) treatment compared to patients without PPI treatment (p=0.69 and p=0.88, respectively). Attenuating effects of concomitant PPI treatment on platelet response to clopidogrel were restricted to the use of omeprazole. No attenuating effects on platelet response to clopidogrel were observed for pantoprazole or esomeprazole. Specifically designed and randomized clinical studies are needed to define the impact of concomitant PPI treatment on adverse events after percutaneous coronary intervention.
Cocoa and Cardiovascular Health
Authors: Corti Roberto , Flammer Andreas J. , Hollenberg Norman K. , Lüscher Thomas F.
Published: March 2009

Epidemiological data demonstrate that regular dietary intake of plant-derived foods and beverages reduces the risk of coronary heart disease and stroke. Among many ingredients, cocoa might be an important mediator. Indeed, recent research demonstrates a beneficial effect of cocoa on blood pressure, insulin resistance, and vascular and platelet function. Although still debated, a range of potential mechanisms through which cocoa might exert its benefits on cardiovascular health have been proposed, including activation of nitric oxide and antioxidant and antiinflammatory effects. This review summarizes the available data on the cardiovascular effects of cocoa, outlines potential mechanisms involved in the response to cocoa, and highlights the potential clinical implications associated with its consumption.
Sensitivity Studies of Aerosol–Cloud Interactions in Mixed-Phase Orographic Precipitation
Authors: Muhlbauer Andreas , Lohmann Ulrike
Published: March 2009

Anthropogenic aerosols serve as a source of both cloud condensation nuclei (CCN) and ice nuclei (IN) and affect microphysical properties of clouds. Increasing aerosol number concentration is assumed to retard the cloud droplet coalescence and the riming process in mixed-phase orographic clouds, thereby decreasing orographic precipitation.

In this study, idealized 3D simulations are conducted to investigate aerosol–cloud interactions in mixed-phase orographic clouds and the possible impact of anthropogenic and natural aerosols on orographic precipitation. Two different types of aerosol anomalies are considered: naturally occurring mineral dust and anthropogenic black carbon.

In the simulations with a dust aerosol anomaly, the dust aerosols serve as efficient ice nuclei in the contact mode, leading to an early initiation of the ice phase in the orographic cloud. As a consequence, the riming rates in the cloud are increased, leading to increased precipitation efficiency and enhancement of orographic precipitation.

The simulations with an anthropogenic aerosol anomaly suggest that the mixing state of the aerosols plays a crucial role because coating and mixing may cause the aerosols to initiate freezing in the less efficient immersion mode rather than by contact nucleation. It is found that externally mixed black carbon aerosols increase riming in orographic clouds and enhance orographic precipitation. In contrast, internally mixed black carbon aerosols decrease the riming rates, leading in turn to a decrease in orographic precipitation.
Structure and Detectability of Trends in Hydrological Measures over the Western United States
Authors: Das T. , Hidalgo H. G. , Pierce D. W. , Barnett T. P. , Dettinger M. D. , Cayan D. R. , Bonfils C. , Bala G. , Mirin A.
Published: March 2009

This study examines the geographic structure of observed trends in key hydrologically relevant variables across the western United States at ⅛° spatial resolution during the period 1950–99. Geographical regions, latitude bands, and elevation classes where these trends are statistically significantly different from trends associated with natural climate variations are identified. Variables analyzed include late-winter and spring temperature, winter-total snowy days as a fraction of winter-total wet days, 1 April snow water equivalent (SWE) as a fraction of October–March (ONDJFM) precipitation total [precip(ONDJFM)], and seasonal [JFM] accumulated runoff as a fraction of water-year accumulated runoff. Observed changes were compared to natural internal climate variability simulated by an 850-yr control run of the finite volume version of the Community Climate System Model, version 3 (CCSM3-FV), statistically downscaled to a ⅛° grid using the method of constructed analogs. Both observed and downscaled model temperature and precipitation data were then used to drive the Variable Infiltration Capacity (VIC) hydrological model to obtain the hydrological variables analyzed in this study. Large trends (magnitudes found less than 5% of the time in the long control run) are common in the observations and occupy a substantial part (37%–42%) of the mountainous western United States. These trends are strongly related to the large-scale warming that appears over 89% of the domain. The strongest changes in the hydrologic variables, unlikely to be associated with natural variability alone, have occurred at medium elevations [750–2500 m for JFM runoff fractions and 500–3000 m for SWE/Precip(ONDJFM)] where warming has pushed temperatures from slightly below to slightly above freezing. Further analysis using the data on selected catchments indicates that hydroclimatic variables must have changed significantly (at 95% confidence level) over at least 45% of the total catchment area to achieve a detectable trend in measures accumulated to the catchment scale.
The Moral Crisis in Post-Mao China: Prolegomenon to a Philosophical Analysis
Authors: Jiwei Ci
Published: March 2009

For quite some time there has been a collective perception of a moral crisis in post-Mao China. This perception is informed by standards held by members of Chinese society rather than by standards outside of it. In this article, the author attempts to lay the groundwork for a philosophical analysis of this moral crisis. He first explains why it is appropriate to speak of a moral crisis and then examines the structure of the crisis. This examination is partly conceptual and partly causal. The conceptual section of the article discusses terms frequently used in connection with the crisis and introduces some terms and distinctions of the author's own for further clarity. The causal section traces the moral crisis to a crisis of identification with moral authority or exemplars, the latter crisis in turn containing important clues to the structure of self and agency in Chinese moral culture.
On Micro-political Philosophy
Authors: Junqing Yi
Published: March 2009

Around the turn of the century, political philosophy became one of the most lively areas of philosophical study in China. An important trend of development is represented by the shift from macro-political philosophy to micro-political philosophy. A careful analysis of this trend is the object of this paper. It shows how, in the Chinese context, micro-political philosophy, micro-history, critique of everyday life, and other theories much debated in the West, are relatively new. As such, a solid foundation for micro-political philosophy must be found within the theoretical resources established in the 20th century western culture, then integrated to the Chinese context and absorbed by this latter to get inspiration.
Political Slogans and Logic
Authors: Nianxi Xia
Published: March 2009

Slogans have always been highly popular in China. They are extensively used in politics, as a typical form of public behavior. They are the most convenient and practical means of mobilizing people. Many political slogans or posters are still fresh in the memories of those who experienced the years of war or revolution in China. The most familiar slogans for people these days are those of the Communist Party of China, which exerted an enormous influence on people's lives.

The English word ‘slogan’ has two corresponding meanings in Chinese: ‘slogan’ and ‘poster’. Slogans are designed to be chanted, exclaimed or shouted by people in public, thus appealing to people's sense of hearing. Posters are designed to be written, and hence appeal to people's sense of vision. This paper explores political slogans from the viewpoint of logics. It analyzes their stipulative structure and the implicit presuppositions they contain. It argues that, from a formal point of view, effective slogans should be free from logical fallacy, easy to remember, and rationally demonstrable.