bluuebunny/crossref_metadata_2025 huggingface dataset:
Cosmic strings: Gravitation without local curvature
Authors: Helliwell T. M. , Konkowski D. A.
Published: March 2005

Cosmic strings are very long, thin structures which might stretch over vast reaches of the universe. If they exist, they would have been formed during phase transitions in the very early universe. The space-time surrounding a straight cosmic string is flat but nontrivial: A two-dimensional spatial section is a cone rather than a plane. This feature leads to unique gravitational effects. The flatness of the cone means that many of the gravitational effects can be understood with no mathematics beyond trigonometry. This includes the observational predictions of the double imaging of quasars and the truncation of the images of galaxies.
Lorentz invariant radiation
Authors: Eriksen E. , Gro/n O/.
Published: March 2005

The energy spectrum of Lorentz invariant radiation is deduced by taking explicit account of the Doppler effect and aberration. A general formula, valid for n spatial dimensions is found.
An accurate determination of the acceleration of gravity for lecture hall demonstration
Authors: Rueckner Wolfgang , Titcomb Paul
Published: March 2005

A new suspension/release mechanism for a free-fall experiment is described. Its design makes it possible to measure time intervals to ±10 μs in free-fall-from-rest experiments. With an overall accuracy of ±0.022%, the different accelerations (in air) of various falling bodies can be determined. Agreement with theory is shown to be very good for the case of spheres. Questions concerning the appropriate drag coefficients applicable are discussed.
The use of quasars in teaching introductory special relativity
Authors: Gabuzda Denise C.
Published: March 2005

One subject in introductory physics which has in the past necessarily been taught using comparatively few examples taken from the natural world is special relativity. If currently prominent theories concerning the physics of quasars are correct, these astronomical objects offer an exciting and illustrative demonstration of naturally occurring large-scale relativistic motion.
The Casimir effect revisited
Authors: Belinfante Frederik J.
Published: March 2005

Using Wick’s normal-ordered expression for the quantum-mechanical energy of a radiation field, so that in absence of matter the zeropoint energy of a radiation field would vanish, the Casimir effect of attraction between uncharged condenser plates in absence of photons will still follow, due to a nonvanishing but finite zeropoint radiation energy in the presence of these plates. If we assume the plates to be transparent for electromagnetic waves of sufficiently high frequency, the remaining zeropoint energy density itself will be finite (and not merely its variation under a change of the distance between the plates). These results are obtained by a more careful consideration of where in sums over modes of vibration one should use sums over running waves with a periodicity condition, where one should sum over standing waves with nodes at conducting boundaries, and where these sums may be replaced by integrals.
Numerical methods in optics: A course about learning physics through computing
Authors: Lock James A.
Published: March 2005

Many advanced undergraduates find it difficult to connect abstract mathematical formalisms with the concrete physical phenomena that they describe. A course in optics from a numerical methods point of view is described. Its purpose is to exploit the students’ familiarity with computng in order to more effectively learn the physics involved in a number of realistic phenomena. The combination of demonstrations, computer calculations, and computer graphics display of the results can prove to be a useful tool in developing physical intuition in students.
Mixing and assimilation in systems of interaction particles
Authors: Ben-Naim A.
Published: March 2005

The concepts of ‘‘mixing’’ and ‘‘assimilation,’’ as previously discussed for ideal gases, are applied to systems of interacting particles. Some common misconceptions frequently found in the literature on solution thermodynamics are noted. These are traced to originate from a faulty interpretation of the thermodynamics of mixing processes.
The vibrating string controversy
Authors: Wheeler Gerald F. , Crummett William P.
Published: March 2005

In the mid-1700s a debate raged between Jean d’Alembert, Leonhard Euler, and Daniel Bernoulli concerning the proper solution to the classical wave equation. This controversy was partially solved by Lagrange and, more conclusively, by Fourier (50 years later) and it provides an interesting case study for the role of mathematics in the modeling of physical phenomena. Of particular note in this debate, was the meaning of boundary conditions. The controversy is summarized from the point of view of this mathematical physics perspective.
The value of studying gene-environment interactions in culturally diverse populations
Authors: Anand Sonia S
Published: March 2005

Cardiovascular disease (CVD) is the leading cause of death and disability in the world. It is anticipated that CVD will reach pandemic proportions by the year 2020. Although the major causes of CVD are well documented and explain the majority of cardiovascular deaths, the prevalence of conventional cardiovascular risk factors vary substantially across diverse cultural groups. These differences are attributed to cultural or genetic differences or to interactions between genes and environmental factors. Substantial efforts have been invested in determining the genetic influences on CVD development, and it is unlikely that a single gene is responsible for the development of atherosclerotic CVD or its classical risk factors such as blood pressure or plasma lipids. It is more plausible that multiple genes, acting either alone or in concert with one another, which display effect modification in the presence of certain environmental factors, are modestly associated with CVD or its main risk factors. Following this hypothesis, studying populations with diversity in environmental factors may increase the discovery potential of gene-environmental interactions. In this brief review, the advantage of studying gene-environment interactions across heterogeneous groups with diverse lifestyles is discussed.Key words: ethnicity, cardiovascular, genes, environment.
Modafinil Elicits Sympathomedullary Activation
Authors: Taneja Indu , Diedrich Andre , Black Bonnie K. , Byrne Daniel W. , Paranjape Sachin Y. , Robertson David
Published: March 2005

The autonomic effects of modafinil (Provigil), a psychostimulant widely used to attenuate fatigue and promote wakefulness, are currently unexplored. We assessed the effect of modafinil on autonomic nervous system. We compared oral modafinil (400 mg×1) versus placebo in 12 healthy hospitalized normal subjects in a randomized double-blind, placebo-controlled cross-over study for 3 days each with subjects in 150 mEq sodium, 70 mEq potassium balance at the Vanderbilt General Clinical Research Center. Modafinil increased resting heart rate (9.2±2.0 bpm; mean [±SE]; 95% confidence interval [CI], 4.7 to 13.6;
P
=0.001), resting systolic blood pressure (7.3±3.2 mm Hg; 95% CI, 0.2 to 14.4;
P
=0.044), and resting diastolic blood pressure (5.3±1.7 mm Hg; 95% CI, 1.4 to 9.1 mm Hg;
P
<0.012). Modafinil elicited a 42% higher orthostatic increase in plasma norepinephrine (0.8±0.3 nmol/L; 95% CI, 0.2 to 1.3;
P
=0.01), and caused a 33% increase in urine norepinephrine (5.1±1.1 nmol/L creatinine per day; 95% CI, 2.7 to 7.4,
P
=0.001), and an 81% increase in urine epinephrine (1.3±0.2 nmol/L creatinine per day; 95% CI, 1 to 2;
P
<0.001). The peroneal microneurographic sympathetic activity was attenuated by modafinil during orthostatic tilt (
P
<0.001). α1-Adrenoreceptor function was maintained. Modafinil substantially perturbs autonomic cardiovascular regulation by increase in heart rate and blood pressure. Autonomic changes of this magnitude encourage caution in use of modafinil in patients with cardiovascular disease.
Phylogenomic approaches to common problems encountered in the analysis of low copy repeats: The sulfotransferase 1A gene family example
Authors: Bradley Michael E , Benner Steven A
Published: March 2005

Background

Blocks of duplicated genomic DNA sequence longer than 1000 base pairs are known as low copy repeats (LCRs). Identified by their sequence similarity, LCRs are abundant in the human genome, and are interesting because they may represent recent adaptive events, or potential future adaptive opportunities within the human lineage. Sequence analysis tools are needed, however, to decide whether these interpretations are likely, whether a particular set of LCRs represents nearly neutral drift creating junk DNA, or whether the appearance of LCRs reflects assembly error. Here we investigate an LCR family containing the sulfotransferase (SULT) 1A genes involved in drug metabolism, cancer, hormone regulation, and neurotransmitter biology as a first step for defining the problems that those tools must manage.

Results

Sequence analysis here identified a fourth sulfotransferase gene, which may be transcriptionally active, located on human chromosome 16. Four regions of genomic sequence containing the four human SULT1A paralogs defined a new LCR family. The stem hominoid SULT1A progenitor locus was identified by comparative genomics involving complete human and rodent genomes, and a draft chimpanzee genome. SULT1A expansion in hominoid genomes was followed by positive selection acting on specific protein sites. This episode of adaptive evolution appears to be responsible for the dopamine sulfonation function of some SULT enzymes. Each of the conclusions that this bioinformatic analysis generated using data that has uncertain reliability (such as that from the chimpanzee genome sequencing project) has been confirmed experimentally or by a "finished" chromosome 16 assembly, both of which were published after the submission of this manuscript.

Conclusion

SULT1A genes expanded from one to four copies in hominoids during intra-chromosomal LCR duplications, including (apparently) one after the divergence of chimpanzees and humans. Thus, LCRs may provide a means for amplifying genes (and other genetic elements) that are adaptively useful. Being located on and among LCRs, however, could make the human SULT1A genes susceptible to further duplications or deletions resulting in 'genomic diseases' for some individuals. Pharmacogenomic studies of SULT1Asingle nucleotide polymorphisms, therefore, should also consider examining SULT1A copy number variability when searching for genotype-phenotype associations. The latest duplication is, however, only a substantiated hypothesis; an alternative explanation, disfavored by the majority of evidence, is that the duplication is an artifact of incorrect genome assembly.
Molecular Changes in Tamoxifen-Resistant Breast Cancer: Relationship Between Estrogen Receptor, HER-2, and p38 Mitogen-Activated Protein Kinase
Authors: Gutierrez M. Carolina , Detre Simone , Johnston Stephen , Mohsin Syed K. , Shou Jiang , Allred D. Craig , Schiff Rachel , Osborne C. Kent , Dowsett Mitch
Published: March 2005

Purpose

To evaluate growth factor receptor cross talk with the estrogen receptor (ER) in paired clinical breast cancer specimens and in a xenograft model before tamoxifen and at tumor progression as a possible mechanism for tamoxifen resistance.

Methods

Specimen pairs from 39 patients were tissue arrayed and stained for ER, progesterone receptor (PgR), Bcl-2, c-ErbB2 (HER-2), and phosphorylated (p) p38 mitogen-activated protein kinase (MAPK), p-ERK1/2 MAPK, and p-Akt. Xenograft MCF-7 tumors before and after tamoxifen resistance were assessed for levels of p-p38.

Results

Pretreatment, there were strong correlations between ER, PgR, and Bcl-2, and an inverse correlation between ER and HER-2. These correlations were lost in the tamoxifen- resistant tumors and replaced by strong correlations between ER and p-p38 and p-ERK. ER expression was lost in 17% of resistant tumors. Three (11%) of the 26 tumors originally negative for HER-2 became amplified and/or overexpressed at resistance. All ER-positive tumors that overexpressed HER-2 originally or at resistance expressed high levels of p-p38. In the pretreatment and tamoxifen-resistant specimens, there were strong correlations between p-p38 and p-ERK. In the tamoxifen-resistant xenograft tumors, like the clinical samples, there was a striking increase in p-p38.

Conclusion

The molecular pathways driving tumor growth can change as the tumor progresses. Crosstalk between ER, HER-2, p38, and ERK may contribute to tamoxifen resistance and may provide molecular targets to overcome this resistance.
Deleterious effects of repeated cold exposure in a freeze-tolerant sub-Antarctic caterpillar
Authors: Sinclair Brent J. , Chown Steven L.
Published: March 2005

Multiple freeze–thaw cycles are common in alpine, polar and temperate habitats. We investigated the effects of five consecutive cycles of approx.–5°C on the freeze-tolerant larvae of Pringleophaga marioniViette (Lepidoptera: Tineidae) on sub-Antarctic Marion Island. The likelihood of freezing was positively correlated with body mass, and decreased from 70%of caterpillars that froze on initial exposure to 55% of caterpillars that froze on subsequent exposures; however, caterpillars retained their freeze tolerance and did not appear to switch to a freeze-avoiding strategy. Apart from an increase in gut water, there was no difference in body composition of caterpillars frozen 0 to 5 times, suggesting that the observed effects were not due to freezing, but rather to exposure to cold per se. Repeated cold exposure did not result in mortality, but led to decreased mass, largely accounted for by a decreased gut mass caused by cessation of feeding by caterpillars. Treatment caterpillars had fragile guts with increased lipid content, suggesting damage to the gut epithelium. These effects persisted for 5 days after the final exposure to cold, and after 30 days, treatment caterpillars had regained their pre-exposure mass, whereas their control counterparts had significantly gained mass. We show that repeated cold exposure does occur in the field, and suggest that this may be responsible for the long life cycle in P. marioni. Although mean temperatures are increasing on Marion Island, several climate change scenarios predict an increase in exposures to sub-zero temperatures, which would result in an increased generation time for P. marioni. Coupled with increased predation from introduced house mice on Marion Island, this could have severe consequences for the P. marioni population.
Comparison of ZrB2‐ZrC‐SiC Composites Fabricated by Spark Plasma Sintering and Hot‐Pressing
Authors: Medri V. , Monteverde F. , Balbo A. , Bellosi A.
Published: March 2005

Ultra‐high temperature ceramics (UHTCs) exhibit a number of properties (thermal and chemical stability, high strength and hardness, ablation/oxidation and thermal shock resistance) for sustained use in the extreme environments experienced by re‐entry space vehicles. The spark plasma sintering (SPS) was considered as a new processible fast approach to develop structural ceramics with improved ultra‐high temperature capabilities.
Estimation of the hindered settling function R(ϕ) from batch‐settling tests
Authors: Lester Daniel R. , Usher Shane P. , Scales Peter J.
Published: March 2005

The hindered settling function R(ϕ) is a material function that quantifies the interphase drag of colloidal suspensions for all solids volume fractions ϕ. A method is presented to estimate R(ϕ) from batch‐settling tests for solids volume fractions between the initial solids volume fraction, ϕ0, and the solids volume fraction at which the suspension forms a continuously networked structure, ϕg, known as the gel point. The method is based on an analytic solution of the associated inverse problem. Techniques are presented to address initialization mechanics observed in such tests as well as experimental noise and discrete data. Analysis of synthetic and experimental data suggests that accurate estimates of R(ϕ) are possible in most cases. These results provide scope for characterization of suspension dewaterability from batch‐settling tests alone. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Experimentally measured shear stress in the standpipe of a circulating fluidized bed
Authors: Sarra Angela , Miller Aubrey L. , Shadle Lawrence J.
Published: March 2005

Shear stress measurements were obtained in the standpipe of a circulating fluidized bed (CFB) for 230‐μm coke breeze particles under a variety of flow conditions. These data were combined with incremental gas‐phase pressure drop readings, and an estimate of the bed weight to predict the solids‐phase pressure drop. It was determined that the wall shear stress and solids‐phase pressure drop are significant portions of the momentum balance and cannot be neglected when modeling frictional flow behavior of Geldart type B powders in a standpipe using the conservation of linear momentum. The combined magnitude of the axial solids‐phase pressure drop and wall shear stress exceeded 48% of the total forces in the mixture momentum balance for a standpipe. However, tests indicated that the influence of the wall shear stress and axial solids pressure in the mixture momentum balance may be assumed to be negligible once minimum fluidization has been exceeded. Under packed standpipe flow conditions most literature applications treat the wall shear stress as being directly proportional to the axial solids pressure divided by a proportionality factor that does not change with solids flow rate. This assumed constant is the product of the Janssen coefficient and coefficient of friction or the stress ratio. However, shear stress measurements indicated that this proportionality factor experienced a large monotonic decrease from conditions of incipient flow, where it was at its maximum, to conditions of high volumetric fluxes, where it approached a much smaller constant value. Two packed‐bed flow regimes were identified. They are the smooth flow regime, characterized as spanning from moderate to large solid volumetric flow rates, and a stick‐slip regime characterized as spanning from incipient to moderate solid volumetric fluxes. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Syntheses of novel silylsubstituted distannanes
Authors: Fischer Roland , Schollmeier Thorsten , Schürmann Markus , Uhlig Frank
Published: March 2005

Starting from diorganodichlorostannanes, a series of novel bis(triorganosilyl)‐stannanes and ‐distannanes has been prepared either by one‐pot reactions via Wurtz‐type coupling reactions with magnesium or lithium and triorganochlorostannanes, or by salt elimination reactions from triorganosilyllithium and diorganodichlorostannanes. A convenient and remarkably straightforward method is the oxidative coupling of potassium stannides with 1,2‐dibromoethane. Isolable intermediates and products were characterized by multinuclear magnetic resonance spectroscopy. In order to prove the constitution of a distannane, an X‐ray crystal structure analysis was performed. Copyright © 2005 John Wiley & Sons, Ltd.
Adsorption characteristics of tributyltin on municipal solid waste compost
Authors: Said‐Pullicino Daniel , Vella Alfred J.
Published: March 2005

The sorption behaviour of tributyltin (TBT) from reconstituted seawater onto municipal solid waste (MSW) compost was investigated to give first insights into the equilibrium and kinetic behaviour of this process. The rate of adsorption, the influence of pH, and the adsorbate hydrophobicity on the partitioning process were investigated. Adsorption kinetics indicated an initial fast rate of adsorption of TBT followed by a slower rate. The similarity of Freundlich sorption and desorption coefficients for TBT showed that the sorption process is also reversible, similar to that for the adsorption of TBT onto marine sediments. It was found that the adsorption capacity for TBT onto compost was highest at pH 6.7, and for other organotins it increased with increasing adsorbate hydrophobicity, following the trend tripropyltin < TBT < tripentyltin. The use of washed MSW compost as a sorbent for the purification of TBT‐contaminated wash waters as generated in large quantities during hull cleaning in dry docks is suggested as a mitigatory measure against pollution of the marine environment by TBT. Calculations suggest that modest amounts of compost will likely be required to treat the contaminated wastewaters generated from the Malta dry docks if a multiple batch system is adopted. Copyright © 2005 John Wiley & Sons, Ltd.
Pyridalyl, a novel insecticide: Potency and insecticidal selectivity
Authors: Isayama S. , Saito S. , Kuroda K. , Umeda K. , Kasamatsu K.
Published: March 2005

Pyridalyl is an insecticide of a novel chemical class (unclassified insecticides). Toxicity of pyridalyl to two insect pest species, Spodoptera litura and Frankliniella occidentalis, an insect predator, Orius stringicollis, and a pollinator, Bombus terrestris, was evaluated in the laboratory. The insecticidal activity of pyridalyl against S. litura was evaluated using the leaf‐dipping method. The potency of pyridalyl was highly effective against all development stages (2nd to 6th instar larvae) of S. litura. This compound was also evaluated against F. occidentalis using the direct spray method. For F. occidentalis, toxicity of pyridalyl was almost similar to that of acrinathrin, but greater than acrinathrin for adults. Then the toxicity of this product to the natural enemies, Orius stringicollis and the pollinating insect Bombus terrestris, was evaluated using the body‐dipping method or direct spray method. No acute toxicity of this product was observed on these non‐target insects. Moreover, the influence of pyridalyl to the nest of Bombus terrestris was evaluated using the direct spray to the inside of the nest. No apparent influence of this compound was observed by 21 days after treatment. The cytotoxicity of pyridalyl to the Sf9 insect cell line and the CHO‐K1 mammalian cell line was evaluated using the trypan‐blue exclusion method. High toxicity to the insect cell line, but almost no toxicity to the mammalian cell line, was observed. Thus, pyridalyl exhibited high selectivity in cytotoxicity between the insect and mammalian cell line as well as in insecticidal activity among insect species. We infer pyridalyl may be useful for IPM programs of greenhouse cultivation system. Arch. Insect Biochem. Physiol. 58:226–233, 2005. © 2005 Wiley‐Liss, Inc.
The role of vegetable and fruit consumption in the aetiology of squamous cell carcinoma of the oesophagus: A case‐control study in Uruguay
Authors: De Stefani Eduardo , Boffetta Paolo , Deneo‐Pellegrini Hugo , Ronco Alvaro L. , Correa Pelayo , Mendilaharsu María
Published: March 2005

There is strong evidence of a protection of high consumption of plant foods against squamous cell carcinoma of the oesophagus, but the respective role of fruits and vegetables is not well elucidated. In the time period 1996–2003, a case‐control study designed in order to address this question was conducted in Uruguay. The study included 200 cases and 400 age‐ and sex‐matched controls. High total vegetable and total fruit consumption was the strongest protective food group for this malignancy (OR 0.31, 95% CI 0.18–0.51). When this food group was dissected in total vegetables and total fruits, the latter item was more protective than the former one (OR for total fruits 0.48, 95% CI 0.35–0.66) (p‐value for difference between both variables 0.04). Finally, when total fruits were dissected in citrus fruits and other fruits, citrus fruits were strongly associated with a reduction in risk (OR 0.47, 95% CI 0.34–0.67). The results of our study point towards an important role of fruits in the prevention of squamous cell carcinoma of the oesophagus. © 2005 Wiley‐Liss, Inc.
Low level, long‐term inorganic arsenite exposure causes generalized resistance to apoptosis in cultured human keratinocytes: Potential role in skin co‐carcinogenesis
Authors: Pi Jingbo , He Yuying , Bortner Carl , Huang Jianli , Liu Jie , Zhou Tong , Qu Wei , North Susan L. , Kasprzak Kazimierz S. , Diwan Bhalchandra A. , Chignell Colin F. , Waalkes Michael P.
Published: March 2005

Inorganic arsenic is a human carcinogen that targets the skin. Carcinogenesis is a multistep process in which acquired apoptotic resistance is a common event and prior work in non‐skin cells shows acquired resistance to apoptosis occurs with chronic arsenite exposure. In the present study, when HaCaT cells, an immortalized, non‐tumorigenic human keratinocyte cell line, were continuously exposed to low‐level inorganic arsenite (as sodium arsenite; 100 nM) for 28 weeks, the cells acquired a generalized resistance to apoptosis. This included resistance to apoptosis induced by acute high concentrations of arsenite, ultraviolet A (UVA) irradiation, and several chemotherapeutic compounds (cisplatin, etoposide and doxorubicin). These arsenite‐tolerant (As‐TL) cells showed similar levels of UVA‐induced reactive oxygen species (ROS) and oxidative DNA damage when compared to passage match control cells. Because cellular apoptosis is dependent on the balance between proapoptotic and survival pathways, the roles of protein kinase B (PKB), a key antiapoptotic molecule, in this acquired apoptotic resistance were investigated. Stimulation of apoptosis markedly decreased nuclear phosphorylated PKB (P‐PKB) levels in control cells, but As‐TL cells showed greatly increased stability of nuclear P‐PKB. Pretreatment of the As‐TL cells with LY294002 or Wortmannin, which specifically inhibit PKB phosphorylation, completely blocked apoptotic resistance in As‐TL cells, indicating acquired apoptotic resistance is associated with increased stability of nuclear P‐PKB. Because arsenic and UV irradiation are co‐carcinogenic in mouse skin, resistance to UV‐induced apoptosis in As‐TL cells may allow UV‐damaged cells to escape normal cell population controls and initiate the carcinogenic cascade. The observation that As‐TL cells show no lessening of UV‐induced genotoxicity supports this possibility. © 2005 Wiley‐Liss, Inc.
Vascular and nonvascular complications of renal transplants: Sonographic evaluation and correlation with other imaging modalities, surgery, and pathology
Authors: Friedewald Sarah M. , Molmenti Ernesto P. , Friedewald John J. , DeJong Marius R. , Hamper Ulrike M.
Published: March 2005

Cadaveric or living donor renal transplantation is commonly performed in individuals with end‐stage renal disease. In recent years, gray‐scale sonography, coupled with color Doppler sonography (CDUS), power Doppler sonography (PDUS), or spectral Doppler sonography, has become the primary imaging modality for these patients. Postoperative serial sonography is performed to detect complications and aid in posttransplant management. In addition, sonography is used to guide percutaneous aspiration of fluid or biopsy to diagnose rejection or renal and perirenal masses.

In this article we discuss the spectrum of sonographic findings, both vascular and nonvascular, of renal transplant complications, including but not limited to renal arterial and venous stenosis and thrombosis, peritransplant collections (lymphoceles, hematomas, urinomas, and seromas), posttransplant lymphoproliferative disorder, and postbiopsy complications (hematomas, pseudoaneurysms, and arteriovenous fistulas). We correlate sonographic findings with those from other imaging modalities (such as angiography, CT, and MRI) and findings at surgery and pathology when possible.
Enhanced efficacy of conditionally replicating herpes simplex virus (G207) combined with 5‐fluorouracil and surgical resection in peritoneal cancer dissemination models
Authors: Nakano Kenji , Todo Tomoki , Zhao Gang , Yamaguchi Koji , Kuroki Syoji , Cohen Justus B. , Glorioso Joseph C. , Tanaka Masao
Published: March 2005

Background

The therapeutic efficacy of G207, a replication‐competent herpes simplex virus, for malignancies is increased when combined with certain chemotherapies, but the mechanism is unclear and the interaction between G207 and surgical resection has not been extensively studied. The goals of the current study were to examine the performance of combination treatments for peritoneal disseminated cancers and to explore the mechanism of effective combinations.

Methods

Hamsters and SCID and BALB/c mice harboring peritoneal dissemination of gallbladder, gastric or colon cancer cells were treated with G207, 5‐fluorouracil (5FU), or surgical resection alone, or G207 combined with 5FU or surgery. Animal survival, antiviral immunity, intratumoral ribonucleotide reductase activity, and viral spread were compared between the groups.

Results

The combination of G207 and 5FU prolonged the survival of hamsters bearing peritoneal dissemination of gallbladder cancer compared with the controls, G207 alone and 5FU alone. 5FU did not suppress the production of neutralizing antibodies against G207, but increased ribonucleotide reductase activity and viral spread in subcutaneous gallbladder tumors. The enhanced efficacy of the combination treatment was also observed in immunodeficient mice with disseminated gastric cancer. Although surgical resection did not significantly prolong animal survival or increase the intratumoral activity of ribonucleotide reductase, long‐term survivors emerged from groups of animals treated with surgical resection and G207 for gallbladder and colon disseminated cancers.

Conclusions

These results indicate that the increased activity of ribonucleotide reductase in tumors mediated by 5FU and the decreased tumor burden resulting from surgical resection may enhance the therapeutic efficacy of oncolytic herpes virus for peritoneal disseminated cancer. Copyright © 2005 John Wiley & Sons, Ltd.
Association of polymorphisms in the cyclin D1 and XPD genes and susceptibility to cancers of the upper aero‐digestive tract
Authors: Buch Shama , Zhu Bing , Gaither Davis Autumn , Odom Dominic , Siegfried Jill M. , Grandis Jennifer R. , Romkes Marjorie
Published: March 2005

DNA repair enzyme genetic polymorphisms have been postulated to increase the risk of certain cancers in the presence of tobacco carcinogen exposures. The XPD protein is an important component of the TFIIH transcription factor complex. XPD genetic polymorphisms resulting in amino acids substitutions may lead to alterations in TFIIH helicase activity, resulting in repair and transcription defects. Cyclin D1 is a key regulatory protein for the transition of cells from the G1‐S cell cycle phase. The CCND1 G870A polymorphism has been reported to enhance alternate splicing of a stable mRNA variant, which may result in the bypass of the G1/S cell cycle checkpoint. In this study, XPD G23591A (Asp312Asn) and A35931C (Lys751Gln) polymorphisms and the CCND1 G870A splice variant frequencies were determined in 273 upper aero‐digestive tract cancer cases and 269 controls. The XPD Asp312Asn variant frequency was significantly different among cases and controls and conferred an odds ratio (OR) of 1.3 (95% CI 1.0–1.8). However, individuals with the CCND1 G870A and XPD Lys751Gln variants had higher age adjusted ORs of 3.2 (95% CI 2.2–4.6) and 2.2 (95% CI 1.5–3.2), respectively. Furthermore, a significant gene–gene interaction was observed among cases with at least two variant alleles for both CCND1 and XPD genes [OR 7.09 (95% CI 4.03–12.5)]. Smokers with a combination of at least one variant allele of both CCND1 and XPD genes also had an elevated risk as compared to nonsmokers. This is the first study to suggest an associative interaction between XPD and CCND1 genetic polymorphisms, tobacco exposure, and cancer risk. © 2005 Wiley‐Liss, Inc.
Localization of the human hedgehog‐interacting protein (Hip) in the normal and diseased pancreas
Authors: Kayed Hany , Kleeff Jörg , Esposito Irene , Giese Thomas , Keleg Shereen , Giese Nathalia , Büchler Markus W. , Friess Helmut
Published: March 2005

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a poor prognosis. Previously, it has been shown that Indian hedgehog (Ihh) and its two signaling receptors patched (Ptc) and smoothened (Smo) are involved in the pathogenesis of chronic pancreatitis (CP) and PDAC. In the current study we analyzed the expression, distribution, and function of another component of this signaling pathway, the human hedgehog‐interacting protein (Hip), in the normal pancreas, CP and PDAC utilizing real‐time quantitative reverse transcription‐polymerase chain reaction (QRT‐PCR), immunohistochemistry, immunofluorescence, Hip siRNA transfection, cell growth assays, and cell cycle analysis. By QRT‐PCR, Hip mRNA levels were fifteenfold and fourteenfold increased in CP (n = 22) and PDAC (n = 31) tissues, respectively, compared to normal pancreatic tissues (n=20) and correlated with glioma associated antigen (Gli1) but not Ptc or Protein kinase A (PKA) mRNA levels. Only SU‐8686 and BxPC‐3 pancreatic cancer cells expressed Hip mRNA, whereas expression was below the level of detection in the other six pancreatic cancer cell lines tested. As shown by immunohistochemistry, Hip was expressed in normal pancreatic tissues mainly in the cytoplasm of islet cells and in smooth muscle cells of blood vessels. In contrast, in CP and PDAC there was a different distribution and staining intensity within the islets. Moreover, Hip immunoreactivity was observed in the tubular complexes, PanIN 1–3 lesions, as well as in pancreatic cancer cells. Incubation of pancreatic cancer cell lines with recombinant Hip revealed a growth inhibitory effect in SU‐8686 and Capan‐1 pancreatic cancer cells and no effect on cell growth in the other tested cell lines. In addition, silencing of Hip expression using specific siRNA molecules increased the growth of SU‐8686 cells. In conclusion, Hip is expressed in the normal pancreas, CP and PDAC tissues. The different pattern of Hip expression and abnormal localization in the diseased pancreas suggest that the enhanced activation of hedgehog signaling in CP and PDAC is—at least in part—due to the aberrant responsiveness and expression of Hip in these diseases. © 2005 Wiley‐Liss, Inc.
Unusual cationic copolymerization behavior of a six‐membered ring spiro‐orthocarbonate bearing adamantane backbones with a monofunctional epoxide
Authors: Hino Tetsuo , Ito Yoshinori , Endo Takeshi
Published: March 2005

Copolymerizations of a six‐membered ring spiro‐orthocarbonate bearing adamantane backbones (AD‐SOC, 1) and a monofunctional epoxide, PGE, in the presence of cationic initiators such as Sc(OTf)3 were carried out under various reaction conditions. As a result, instead of the anticipated poly(ether‐ether‐carbonate) 11, two types of copolyethers (12 and 18) consisting of two or three types of ether components having different substituent groups were unusually formed along with the evolution of carbon dioxide gas, in which AD‐SOC efficiently acted as the corresponding oxetane equivalent monomers 3 and 4. Furthermore, the copolymerization behavior, including the formation of copolyethers 12 and 18, unexpectedly and significantly depended on the reaction conditions, such as the concentration of the initiator. For example, the copolymerizations with 5 mol % of Sc(OTf)3 mainly afforded copolyether 18, while those with 1 mol % mainly gave copolyether 12. In addition, treatments with 5 mol % of Sc(OTf)3 also yielded CH2Cl2, THF, and DMF‐insoluble networked products, indicating relatively higher thermal stability compared with a common polyether. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1729–1740, 2005
Synthesis of three‐armed poly(trans‐4‐hydroxy‐N‐benzyloxycarbonyl‐L‐proline)‐block‐poly(ε‐caprolactone) copolymers
Authors: Lee Ren‐Shen , Yang Jen‐Ming
Published: March 2005

A series of novel types of three‐armed poly(trans‐4‐hydroxy‐N‐benzyloxycarbonyl‐L‐proline)‐block‐poly(ε‐caprolactone) (PHpr‐b‐PCL) copolymers were successfully synthesized via melt block copolymerization of trans‐4‐hydroxy‐N‐benzyloxycarbonyl‐L‐proline (N‐CBz‐Hpr) and ε‐caprolactone (ε‐CL) with a trifunctional initiator trimethylolpropane (TMP) and stannous octoate (SnOct2) as a catalyst. For the homopolycondensation of N‐CBz‐Hpr with TMP initiator and SnOct2 catalyst, the number‐average molecular weight (Mn) of prepolymer increases from 530 to 3540 g mol−1 with the molar ratio of monomer to initiator (3–30), and the molecular weight distribution (Mw/Mn) is between 1.25 to 1.32. These three‐armed prepolymer PHpr were subsequently block copolymerized with ε‐caprolactone (ε‐CL) in the presence of SnOct2 as a catalyst. The Mn of the copolymer increased from 2240 to 18,840 g mol−1 with the molar ratio (0–60) of ε‐CL to PHpr. These products were characterized by differential scanning calorimetry (DSC), 1H NMR, and gel permeation chromatography. According to DSC, the glass‐transition temperature (Tg) of the three‐armed polymers depended on the molar ratio of monomer/initiator that were added. In vitro degradation of these copolymers was evaluated from weight‐loss measurements and the change of Mn and Mw/Mn. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1708–1717, 2005
Reversible gel formation of triblock copolymers studied by molecular dynamics simulation
Authors: Guo Lei , Luijten Erik
Published: March 2005

Molecular dynamics simulations have been employed to study the formation of a physical (thermoreversible) gel by amphiphilic A‐B‐A triblock copolymers in aqueous solution. To mimic the structure of the hydrogel‐forming polypeptides employed in experiments [W.A. Petkaet al., Science281, 389 (1998)], the end blocks of the polymer chains are modeled as hydrophobic rods representing the α‐helical part of the polypeptides, whereas the central B block is hydrophilic and semiflexible. We have determined structural properties, such as the hydrophobic cluster‐size distribution function, the geometric percolation point, and pair correlation functions, and related them to the dynamic properties of the system. Upon a decrease in the temperature, a network structure is formed in which bundles of end blocks act as network junctions. Both at short and medium distances, increased ordering is observed, as characterized by the pair correlation function. Micelle formation and the corresponding onset of geometric percolation induce a strong change in dynamic quantities (e.g., in the diffusion constant and the viscosity) and cause the system to deviate from the Stokes–Einstein relation. The dynamic properties show a temperature dependence that is strongly reminiscent of the behavior of glass‐forming liquids. The appearance of a plateau in the stress autocorrelation function suggests that the system starts to exhibit a solid‐like response to applied stress once the network structure has been formed, although the actual sol–gel transition occurs only at a considerably lower temperature. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 959‐969, 2005
High‐current AlInN/GaN field effect transistors
Authors: Dadgar A. , Neuburger M. , Schulze F. , Bläsing J. , Krtschil A. , Daumiller I. , Kunze M. , Günther K.‐M. , Witte H. , Diez A. , Kohn E. , Krost A.
Published: March 2005

We present a study on AlInN/GaN field effect transistors (FETs) grown by metalorganic chemical vapor phase epitaxy. AlInN can be grown lattice‐matched to GaN with an In concentration of 18%. In this study samples with In concentrations ranging from 9.5 to 24%, covering a range from tensely to compressively strained AlInN layers, were grown on GaN layers on Si(111). From Hall effect and capacitance‐voltage measurements we find high sheet carrier densities for most of the samples indicating a high electron density at the AlInN/GaN heterointerface. This is also reflected in the behavior of processed FETs. Nearly lattice‐matched structures show sheet carrier densities of 3.2 × 1013 cm–2 and mobilities up to ∼406 cm2/Vs. Such Al0.84In0.16N FETs have maximum DC currents of 1.33 A/mm for devices with 1 µm gate length and 100 µm gate width and an output power of 2.5 W/mm at 2 GHz. The best devices with In concentrations of 19% show maximum output powers of 4.1 W/mm at 2 GHz. In contrast to that a compressively strained AlInN layer with an In concentration of 24% leads to a decreased polarization charge at the heterointerface and a low DC current of ∼70 mA/mm. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Local coexistence of tree species and the dynamics of global distribution pattern along an environmental gradient: a simulation study
Authors: Takenaka Akio
Published: March 2005

A spatially explicit tree‐based model was used to demonstrate the effects of a mechanism promoting multiple‐species coexistence on the development of vegetation zonation and its response to climate change. Temporal fluctuation in reproduction was incorporated as the mechanism, which facilitates the persistence of less competitive species. Four hypothetical tree species with different temperature dependencies of seed production were randomly located over a landscape represented by 2,000×40 cells. Each cell can sustain a single tree at most. A zonal distribution pattern emerged corresponding to the temperature gradient along the long axis of the landscape. When there was a temporal variation in seed production, species became distributed over a wider range than that when seed production was constant. When the whole landscape was warmed, the distribution range of each species shifted towards the cool end of the landscape. However, the migration was retarded due to competition for vacant spaces with the remnant species which had dominated the location before the warming. Temporal fluctuation in reproduction facilitated the migration because it enhanced the persistence of minority species and, thus, the invasion and establishment of new species in the area dominated by other species.
Adolescent gender differences in mattering and wellness
Authors: Rayle Andrea Dixon
Published: March 2005

Mattering to others has been associated with psychosocial well‐being and overall wellness. The relationship of perceived interpersonal and general mattering to overall wellness was studied with a sample of 462 high school students (229 males and 233 females). The two measures of perceived mattering (the Mattering to Others Questionnaire and the General Mattering Scale) were significantly but modestly interrelated (r=.29). Both scales were significantly correlated with overall scores on the Wellness Evaluation of Life Style—Teenage form. Females perceived they matter to their families, and in general, more than do males, and mattering significantly predicted wellness for females.
Market priorities, manufacturing configuration, and business performance: an empirical analysis of the order‐winners framework
Authors: da Silveira Giovani J.C.
Published: March 2005

This study carries out an empirical test of the order‐winners framework in manufacturing organizations. Hill [Hill, T., 1985. Manufacturing Strategy: The Strategic Management of the Manufacturing Function, first ed. Macmillan, Basingstoke; Hill, T., 2000. Manufacturing Strategy: Text and Cases, second ed. Palgrave, Basingstoke] proposed the order‐winners framework to help managers to improve understanding about markets and to develop a consistent manufacturing strategy. The framework defines ideal profiles of products and markets, and manufacturing and investment decisions that relate to alternative process choices. The study tests the hypothesis of a negative relationship between misfit to an ideal profile defined in the framework and business performance in domestic market share, return on sales, and return on investment in a survey of 183 manufacturers from 17 countries. Results found a significant negative relationship between misfit and domestic market share. The study contributes to operations management research by developing a methodology to measure fit as profile deviation in the context of manufacturing, and applying this methodology to the order‐winners framework.
Immature secretory granules are not acidic in Paramecium: Implications for sorting to the regulated pathway
Authors: de Loubresse Nicole Garreau , Gautier Marie‐Christine , Sperling Linda
Published: March 2005

Summary— Paramecium, like other ciliates, has a system of regulated secretion. The secretory storage granules, known as trichocysts, are of large size and elaborate architecture and occupy in wild type cells a significant fraction of the cellular volume. They thus provide an excellent model system for studies of secretory granule biogenesis. Previous analysis of secretory mutants unable to produce functional trichocysts (Gautier et al (1994). J Cell Biol 124, 893–902) suggested that one of the mutants studied, trichless, might have defective organelle acidification. We have therefore applied a technique (Anderson et al (1984) Proc Natl Acad Sci USA 81, 4838–4842) for the postembedding characterization of acidic compartments using the weak base 3‐(2,4‐dinitroanilino)‐3′‐amino‐N‐methyldipropylamine (DAMP) to Paramecium. Quantitative immunolocalization experiments using double label (antibodies against DAMP and against regulated secretory proteins) show that secretory granules are not significantly acidic at any stage of their development in Paramecium. Analysis of trichless mutant cells shows that organelle acidification is not defective and allows us to follow the regulated secretory proteins from apparently normal immature secretory granules to a probable degradative compartment. Consideration of the ensemble of the results leads us to discuss the possibility that immature secretory granules are a sorting compartment in Paramecium, as originally proposed by Kuliawat and Arvan ((1994) J Cell Biol 126, 77–86) for the insulin producing β‐cells of pancreatic islets.
A WEATHER-BASED SCHEME TO ADVISE ON LIMITED CHEMICAL CONTROL OF GROUNDNUT LEAF SPOT DISEASES IN INDIA
Authors: BUTLER D. R. , WADIA K. D. R. , REDDY R. K. , DAS N. D. , JOHNSON B. , KUMARI MEENA , KRISHNA MURTY K. , SREENIVAS B. , SRIVASTAVA N. N.
Published: March 2005

Infection of groundnut by pathogens causing early and late leaf spot diseases is strongly affected by accumulated daily leaf wetness periods and, in the rainy season, temperature is unlikely to severely limit infection. Earlier work relating patterns of leaf wetness to infection, was used to define a daily Wetness Index (WI) which was compared with infection on inoculated plants exposed in the crop for periods of 7 d. Infection was only severe when the 7-d WI total exceeded a value of 2.3. The proportion of leaves with one or more lesions on the main stem was used to assess the amount of inoculum in the crop. When the proportion of diseased leaves exceeded 10% and the WI total exceeded the threshold, application of a fungicide was advised. Successive sprays were separated by at least 14 d and a maximum of three sprays were applied in the growing season. Field trials showed that three sprays gave limited benefit where the disease pressure was severe, but substantial increases in pod and haulm yield were possible with only one or two fungicide applications in locations with less disease pressure.