bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysing the Digital Divide Factors: Evidence of a Rural-urban Comparison from an Indian District
Authors: Chaudhuri Adrija
Published: March 2024

Aims: The digital divide is the difference in access to technology between areas. The study district is characterised by plain and hilly topography, forest and tea garden areas, much of which are backward in terms of geographical location, industrial and infrastructure development.  Under this backdrop, this study tries to identify the different factors leading to Digital Divide in the rural and urban areas of Alipurduar district, India
Study Design: The study has been carried out on the basis of quantitative technique. For the purpose of the study, a total of 120 samples have been collected both from rural and urban areas of the study district
Place and Duration of Study: This has been conducted from February, 2023 to July, 2023 rural and urban areas of Alipurduar district.
Methodology: Stratified Random sampling has been performed for selecting the samples to be surveyed. Questions related to the access and usage of Internet, computer and android phones have been included in the Questionnaire.
Results: The study results show that the network connectivity has a significant relation with Digital divide (p=0.00), followed by English language deficiency (p=0.00) and Gender (p=0.00) respectively. Such results are the cause of lesser awareness about the importance of English language and socio-economically and educationally backwardness of people, particularly women. The study also reveals that there is a significant relationship between area of residence and digital divide (p=0.003). The digital divide increases away from the urban area towards the rural area and majority of the rural parts of the study area is located either in hilly or in forest areas.  The network connectivity issue, techno-scepticism, English language deficiency, gender and place of residence are revealed as leading factors of digital divide in the area under study.
Conclusion: The paper proposes to enhance network connectivity and suggests a special drive for capacity building in terms of digital literacy and usage of ICT devices, particularly in the rural area. Simultaneously, there is an urgent need to aware people of the remote and rural areas about the importance of English language in general, and women in particular to reduce the spatial and gendered gap in digital literacy in the study district.
Uzaktan Eğitimle Uygulanan Oyun Etkinliklerinin Down Sendromlu Çocukların Motor Becerilerine Etkisi
Authors: UYGUR Ezgi Hazal , ASLAN Şehmus
Published: March 2024

Bu araştırmanın amacı, Down Sendromlu (DS) çocuklara uzaktan eğitim yoluyla uygulanan uyarlanmış oyun etkinlikleri modülünün motor beceriler üzerine etkisini incelemektir. Bu araştırmaya 20 (10 erkek, 10 kız) DS’li çocuk katıldı. Araştırmaya Denizli’de yaşayan 4-7 yaş aralığındaki DS’lu çocuklar katıldı. DS’li çocukların yaş ortalaması 5,25±1,02 yıldır. Araştırmada MEB Oyun Etkinlikler Modülünden uyarlanarak oyun ve egzersizlerden oluşturulan etkinlik programı 2 farklı çalışma grubu oluşturularak, uzaktan eğitim yoluyla 12 hafta süresince haftada 2 gün, 60 dakika süreyle uygulandı. Uyarlanmış egzersiz programından önce ve programdan sonra çocukların ön test ve son test motor beceri ölçümleri Bruininks-Oseretsky Motor Yeterlilik Testi Kısa Formu (BOT-2 KF) ile değerlendirildi. Araştırmaya katılan kız ve erkek DS’li çocukların BOT-2 KF tüm alt testleri ve toplam puan ortalamaları arasında anlamlı bir fark bulunmamıştır (p>0.05). Yaşa göre farklılık incelendiğinde BOT-2 KF toplam puanları ve ince motor doğruluk, el becerisi ve kuvvet alt testlerinde 6-7 yaş grubundaki DS’li çocuklar lehine anlamlı fark tespit edilmiştir (p
Efficient White‐Electrophosphorescent Devices Based on a Single Polyfluorene Copolymer
Authors: Wu F.‐I. , Yang X.‐H. , Neher D. , Dodda R. , Tseng Y.‐H. , Shu C.‐F.
Published: March 2007

An efficient white‐light‐emitting polymer (W3) is realized by covalently attaching a green fluorophore and a red phosphor into the backbone and the side chains, respectively, of polyfluorene at a concentration of 0.04 mol %. In addition, charge‐transporting pendant units are included to improve carrier injection and transport. White‐electrophosphorescent devices with the structure ITO/PEDOT:PSS/W3/CsF/Al (ITO: indium tin oxide; PEDOT:PSS: poly(styrenesulfonate)‐doped poly(3,4‐ethylenedioxythiophene)) exhibit a low turn‐on voltage of 2.8 V and a luminance of ca. 103 cd m–2 at below 6 V. The peak luminance and power‐conversion efficiencies are 8.2 cd A–1 and 7.2 lm W–1, respectively. Furthermore, the device shows relatively stable white emission: the Commission Internationale d'Éclairage (CIE) chromaticity coordinates of the devices change only slightly from (0.35,0.38) at 10 mA cm–2 to (0.33,0.36) at 100 mA cm–2, with an almost constant color render index (CRI) value of 82 at all measured current densities.
High strength nylon micro‐ and nanofiber based nonwovens via spunbonding
Authors: Fedorova Nataliya , Pourdeyhimi Behnam
Published: March 2007

In this study we explore the feasibility of using of islands‐in‐the‐sea (I/S) fibers in the spunbond process to produce relatively high strength micro‐ and nanofiber webs. The relationships between the number of islands, percent polymer composition, and the fiber and fabric properties are reported. Nylon 6 (N6) and poly (lactic) acid (PLA) were used as the islands and sea polymers, respectively. Micro‐ and nanofibers were obtained by dissolving PLA polymer from the final spunbond nonwovens. The fibers with 25% N6 showed a decrease in fiber diameter from 1.3 to 0.36 μm (micron) when the number of islands was increased from 36 to 360. The diameter of fibers with 75% N6 showed a decline from 2.3 to 0.5 μm for the same range. Hydroentangling was found to be the preferred method of bonding of the I/S structures; the bonded structures were able to withstand postprocessing steps required for dissolving of the sea from the resulting nonwovens. Hydroentanged micro‐ and nanofiber based nonwovens demonstrated high tensile and tear properties, which were insensitive to the N6 fiber size and its mechanical properties. Bonding efficiency and web uniformity were found to be dominant factors influencing the fabric performance. Overall, our study demonstrated that the I/S configuration is a promising technique for high speed and high throughput production of strong and light weight nonwovens comprised of micro‐ and nanofibers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Synthesis and characterization of novel water‐soluble polyesters for electrical insulation
Authors: Jejurkar U. , Shrinet V. , Murthy C. N. , Jain R. C. , Singh A. K. , Ramamoorty M.
Published: March 2007

Polyesters based on poly(alkyl anhydride), aromatic anhydrides, and polyglycols were synthesized by thermal and catalytic condensation polymerization techniques. The polymerization conditions were optimized by the variation of the monomer concentration, reaction temperature, and so on to achieve the desired properties. The reaction was monitored by the measurement of the acid values at different stages of the polymerization reaction. The water solubility of these polyesters was achieved by the termination of the reaction with the addition of ammonia. These polyester resins were characterized with IR and viscosity measurements. The electrical properties of polyester resins coated and cured on glass cloth were measured with the idea of using them as impregnating varnishes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Thermal conductivity of homogeneous alignment networks formed with mono‐ and bi‐functional polymerizable liquid crystals
Authors: Kato Takashi , Nakamura Takashi , Agari Yasuyuki , Ochi Mitsukazu
Published: March 2007

Mixtures consisting of mono‐functional polymerizable liquid crystals (PLC) having a polymerizable moiety on the molecular short axis terminal and a bi‐functional PLC having the polymerizable moieties on the molecular long axis terminals were prepared. These mixtures had a wide liquid crystal range. Uniaxially aligned films were prepared from the PLC mixtures by photo polymerization after aligning the molecular directions by the rubbing method. The thermal conductivity of the films increased from 0.45 to 0.68 W/m · K with the increase ofthe content of the bi‐functional PLC. The relation between the thermal conductivity and the PLC network styles was investigated from the aspect of the molecular order. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Influence of silica loading on the mechanical properties and resistance to oil and thermal aging of CR/NR blends
Authors: Sae‐oui Pongdhorn , Sirisinha Chakrit , Wantana Thanandon , Hatthapanit Kannika
Published: March 2007

Blends of 75/25 chloroprene rubber(CR)/natural rubber (NR) filled with various loadings of precipitated silica were prepared and their processability and mechanical properties as well as their resistance to thermal aging and oil were determined. The blend morphology was also studied using the atomic force microscopy technique. The results reveal that the mixing energy and the Mooney viscosity of the compound are increased continuously with increasing silica loading. It is also found that both scorch and optimum curing times are shortened while the total crosslink density is increased with increasing silica loading. The positive effect on cure could be explained by the chemical reaction between the allylic chlorine atom of CR and the silanol group on silica surface. The tensile strength, modulus, and hardness of the blend vulcanizate are noticeably improved while the compression set at elevated temperature is impaired with increasing silica loading. The results also reveal that both thermal aging resistance and oil resistance of the blend vulcanizates, as represented by the relative properties, are enhanced with the addition of silica. The resistance enhancement is believed to arise from the combination of the dilution effect, the increased crosslink density and also the reduction of NR dispersed phase size. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
The american college of rheumatology 1991 revised criteria for the classification of global functional status in rheumatoid arthritis
Authors: Hochberg Marc C. , Chang Rowland W. , Dwosh Isaac , Lindsey Stephen , Pincus Theodore , Wolfe Frederick
Published: March 2007

Objective. To develop and validate revised criteria for global functional status in rheumatoid arthritis (RA(.

Methods. Revised criteria were formulated and tested for criterion and discriminant validity in 325 patients with RA.

Results. The revised criteria developed are as follows: class I = able to perform usual activities of daily living (self‐care, vocational, and avocational); class II = able to perform usual self‐care and vocational activities, but limited in avocational activities; class III = able to perform usual self‐care activities but limited in vocational and avocational activities; class IV = limited in ability to perform usual self‐care, vocational, and avocational activities. Usual self‐care activities include dressing, feeding, bathing, grooming, and toileting; vocational and avocational activities are both patient‐desired and age‐, and sex‐specific. The distribution properties of this classification schema were superior to those of the original Steinbrocker criteria. Mean Health Assessment Questionnaire scores were significantly (P < 0.0001) different between, and increased across, the 4 classes.

Conclusion. Although there are limitations inherent in the use of global ordinal scales, the American College of Rheumatology revised criteria will be useful in describing the functional consequences of RA. A more detailed quantitative measure of physical disability should be used, however, for optimal monitoring of patients' clinical status in office practice and clinical research.
HLA antigens in north american patients with takayasu arteritis
Authors: Khraishi Majed M. , Gladman Dafna D. , Dagenais Pierre , Fam Adel G. , Keystone Edward C.
Published: March 2007

Objective. To determine the frequency of HLA class I and II antigens in Caucasian North American patients with Takayasu arteritis (TA).

Methods. Seventy‐three class I antigens and 13 class II antigens were examined in 21 Caucasian North American patients with TA, and their frequencies were compared with findings in 243 healthy, untreated controls. HLA typing was performed by microlymphocytotoxicity assay.

Results. We found no statistically significant positive association of TA with DR2, DR4, DQw3, or any of the other class I or class II antigens studied. A negative association between TA and DR1 was noted. There was no significant association between any of the HLA antigens and the severity of the disease or the presence of complications.

Conclusion. The negative association between TA and the DR1 antigen suggests that this antigen may be protective against the development of the disease.
Hereditary dysfunction of the third component of complement associated with a systemic lupus erythematosus‐like syndrome and meningococcal meningitis
Authors: Nilsson Ulf R. , Nilsson Bo , Storm Karl‐Erik , Sjölin‐Forsberg Gunilla , Hällgren Roger
Published: March 2007

Objective. We describe a dysfunction of C3 in a patient with a systemic lupus erythematosus (SLE)‐like syndrome. Alternative pathway complement function was absent, but classical pathway complement function was partially intact.

Methods. We used functional, preparative, and immunochemical techniques in the study.

Results. The patient's C3 proved normally susceptible to trypsin proteolysis and partially resistant to classical pathway, but completely resistant to alternative pathway, convertase‐dependent cleavage.

Conclusion. The dysfunction, thus, was caused by a failure of C3 to interact with the C3 convertases, rather than by a lack of a proteinase‐sensitive cleavage site in the deficient protein.
Random‐coefficients hidden‐Markov Poisson regression models for inferring a competitor's promotion strategy
Authors: Ledolter Johannes
Published: March 2007

In this paper we consider the case of a drug manufacturer who has physician‐level information on the prescription volume for its own brand and its competitor, has complete physician‐level data on its own free‐sampling plan, but has only sparse data on the competitor's promotion strategy. We investigate whether one is able to predict the competitor's promotion strategy from such limited data. We treat the competitor's promotion as a latent (unobservable) event, and propose a hidden Markov model (HMM) to describe its progression over time. Analysis of actual and simulated data shows that the HMM improves our ability to infer the missing promotion event if promotions are serially correlated. A simpler model assuming that the probability of transition from one sampling state to the other is independent of the current state is adequate if the serial correlation among promotions is weak. Copyright © 2007 John Wiley & Sons, Ltd.
Western blot analysis to illustrate relative control levels of the lac and ara promoters in Escherichia coli
Authors: Nielsen Brent L. , Willis Van C. , Lin Chin‐Yo
Published: March 2007

The lactose operon and its control is a fundamental transcriptional regulatory concept presented in introductory and many advanced molecular biology courses. Much is known about the positive and negative control mechanisms that govern levels of expression of this operon. One basic principle that is taught about the lac operon is that it is “leaky,” meaning that the transcriptional control of the operon is not 100% efficient and that in wild‐type cells, transcription from the promoter is never completely “off,” but there is always some basal transcription. In contrast, the arabinose operon is often used as an example of a tightly controlled operon, and transcription from the ara promoter is very low in the absence of inducer. The relative levels of control of these two operons can be illustrated using Western blots of proteins expressed in the presence and absence of the appropriate inducers and antibodies against the gene products. Different times of growth and the addition of inducer can also be examined. The results are very dramatic and help to reinforce the principles of promoter control.
Coupled reactions versus connected reactions: Coupling concepts with terms
Authors: Aledo Juan Carlos
Published: March 2007

A hallmark of living matter is its ability to extract and transform energy from the environment. Not surprisingly, biology students are required to take thermodynamics. The necessity of coupling exergonic reactions to endergonic processes is easily grasped by most undergraduate students. However, when addressing the thermodynamic concept of coupled reactions, both students and textbook authors often make claims that clash with the Second Law of Thermodynamics. Herein, I point out the most common flaws, analyze the causes leading to these mistakes, and suggest a few rules to avoid them.
Developmental origin and identity of song system neurons born during vocal learning in songbirds
Authors: Scott Benjamin B. , Lois Carlos
Published: March 2007

New neurons are added to the forebrain song control regions high vocal center (HVC) and Area X of juvenile songbirds but the identity and site of origin of these cells have not been fully characterized. We used oncoretroviral vectors to genetically label neuronal progenitors in different regions of the zebra finch lateral ventricle. A region corresponding to the mammalian medial and lateral ganglionic eminences generated medium spiny neurons found in Area X and in the striatum surrounding Area X, and at least two classes of interneurons found in HVC. In addition, our experiments indicate that the HVC projection neurons that project into nucleus robust nucleus of the arcopallium (RA) are born locally from the ventricular region immediately dorsal to HVC. The ability to genetically target neuron subpopulations that give rise to different song system cell types provides a tool for specific genetic manipulations of these cell types. In addition, our results suggest striking similarities between neurogenesis in the embryonic mammalian brain and in the brain of the juvenile songbird and provide further evidence for the existence of conserved cell types in the forebrain for birds and mammals. J. Comp. Neurol. 502:202–214, 2007. © 2007 Wiley‐Liss, Inc.
Modification of classical neurochemical markers in identified primary afferent neurons with Aβ‐, Aδ‐, and C‐fibers after chronic constriction injury in mice
Authors: Ruscheweyh Ruth , Forsthuber Liesbeth , Schoffnegger Doris , Sandkühler Jürgen
Published: March 2007

It is functionally important to differentiate between primary afferent neurons with A‐fibers, which are nociceptive or nonnociceptive, and C‐fibers, which are mainly nociceptive. Neurochemical markers such as neurofilament 200 (NF200), substance P (SP), and isolectin B4 (IB4) have been useful to distinguish between A‐ and C‐fiber neurons. However, the expression patterns of these markers change after peripheral nerve injury, so that it is not clear whether they still distinguish between fiber types in models of neuropathic pain. We identified neurons with Aβ‐, Aδ‐, and C‐fibers by their conduction velocity (corrected for utilization time) in dorsal root ganglia taken from mice after a chronic constriction injury (CCI) of the sciatic nerve and control mice, and later stained them for IB4, SP, calcitonin gene‐related peptide (CGRP), NF200, and neuropeptide Y (NPY). NF200 remained a good marker for A‐fiber neurons, and IB4 and SP remained good markers for C‐fiber neurons after CCI. NPY was absent in controls but was expressed in A‐fiber neurons after CCI. After CCI, a group of C‐fiber neurons emerged that expressed none of the tested markers. The size distribution of the markers was investigated in larger samples of unidentified dorsal root ganglion neurons and, together with the results from the identified neurons, provided only limited evidence for the expression of SP in Aβ‐fiber neurons after CCI. The extent of up‐regulation of NPY showed a strong inverse correlation with the degree of heat hyperalgesia. J. Comp. Neurol. 502:325–336, 2007. © 2007 Wiley‐Liss, Inc.
Reactive plasticity in the dentate gyrus following bilateral entorhinal cortex lesions in cynomolgus monkeys
Authors: Shamy Jul Lea , Buckmaster Cindy A. , Amaral David G. , Calhoun Michael E. , Rapp Peter R.
Published: March 2007

Hippocampal structural plasticity induced by entorhinal cortex (EC) lesions has been studied extensively in the rat, but little comparable research has been conducted in primates. In the current study we assessed the long‐term effects of bilateral aspiration lesions of the EC on multiple markers of circuit organization in the hippocampal dentate gyrus of young adult monkeys (Macaca fascicularis). Alternate histological sections were processed for the visualization of somatostatin and vesicular acetylcholine transporter (VAChT) immunoreactivity and acetylcholinesterase histochemistry (AChE). The markers revealed the distinct laminar organization of dentate gyrus circuitry for stereology‐based morphometric quantification. Consistent with findings in rats, the volume of the somatostatin‐immunopositive outer molecular layer (OML), innervated by projections from the EC, was decreased by 42% relative to control values. The inner molecular layer (IML) displayed a corresponding volumetric expansion in response to denervation of the OML as measured by AChE staining, but not when visualized for quantification by VAChT immunoreactivity. Nonetheless, stereological estimation revealed a 36% increase in the total length of VAChT‐positive cholinergic fibers in the IML after EC damage, along with no change in the OML. Together, these findings suggest that despite substantial species differences in the organization of hippocampal circuitry, the capacity for reactive plasticity following EC damage, previously documented in rats, is at least partly conserved in the primate dentate gyrus. J. Comp. Neurol. 500:192–201, 2007. © 2007 Wiley‐Liss, Inc.
Compositional variation in 0.65 PbMg2/3Nb1/3O3 ‐0.35 PbTiO3 single crystals grown by high temperature solution growth technique
Authors: Bhaumik I. , Singh G. , Ganesamoorthy S. , Karnal A. K. , Tiwari M. K. , Tiwari V. S.
Published: March 2007

Single crystals of lead magnesium niobate titanate, 0.65 PbMg2/3Nb1/3O3 (PMN) ‐0.35PbTiO3 (PT) were grown using flux method near morphotropic phase boundary (MPB) composition. The crystals grown at the centre of the platinum crucible were found to PT deficient compared to those grown near the walls of the crucibles. A variation of ∼3.8 mol% in PT concentration was found in the crystals grown at the wall and at the centre of the crucible. The difference in the chemical composition of crystals grown at the centre and the near the wall of the crucible was observed by X‐ray diffraction, EDXRF, dielectric and thermal measurements. The presence of PT rich and deficient crystals is explained in terms of the segregation coefficient of PT in PMN. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On a trie partitioning algorithm for power‐efficient TCAMs
Authors: Lu Haibin
Published: March 2007

Internet routers conduct routing table (RT) lookup based on the destination IP address of the incoming packet to decide which output port to forward the packet. Ternary content‐addressible memories (TCAM) uses parallelism to achieve lookup in a single cycle. One of the major drawbacks of TCAM is its high‐power consumption. Trie‐based architecture has been proposed to reduce TCAM power consumption. The idea is to use an index TCAM to select one of many data TCAM blocks for lookup. However, power reduction is limited by the size of the index TCAM, which is always enabled for search. In this paper we develop a simple but effective trie‐partitioning algorithm to reduce the index TCAM size, which achieves better reduction in power consumption, and at the same time guarantees full TCAM space utilization. We compared our algorithm (LogSplit) with PostOrderSplit (IEEE INFOCOM, 2003). For two real‐world RTs (AADS and PAIX), the size of the index TCAM generated by LogSplit is 55–70% of that generated by PostOrderSplit; the largest power reduction factor of LogSplit is 41 for AADS and 68 for PAIX, while the largest power reduction factor of PostOrderSplit is 33 for AADS and 52 for PAIX. The improvement is even more significant in the worst case: the size of the index TCAM generated by LogSplit is 18–30% of that generated by PostOrderSplit for IPv4, and less than 1% of that generated by PostOrderSplit for IPv6; the largest power reduction factor of LogSplit is 173 for both IPv4 and IPv6, while the largest power reduction factor of PostOrderSplit is only 82 for IPv4 and 41 for IPv6. Copyright © 2007 John Wiley & Sons, Ltd.
Multifold node authentication in mobilead hocnetworks
Authors: Komninos Nikos , Vergados Dimitrios D. , Douligeris Christos
Published: March 2007

Anad hocnetwork is a collection of nodes that do not need to rely on a predefined infrastructure to keep the network connected. Nodes communicate amongst each other using wireless radios and operate by following a peer‐to‐peer network model. In this article, we propose a multifold node authentication approach for protecting mobilead hocnetworks. The security requirements for protecting data link and network layers are identified and the design criteria for creating securead hocnetworks using multiple authentication protocols are analysed. Such protocols, which are based on zero‐knowledge and challenge‐response techniques, are presented through proofs and simulation results. Copyright © 2007 John Wiley & Sons, Ltd.
Mice with GFAP‐targeted loss of neurofibromin demonstrate increased axonal MET expression with aging
Authors: Su Weiping , Xing Rubing , Guha Abhijit , Gutmann David H. , Sherman Larry S.
Published: March 2007

Neurofibromatosis 1 (NF1) is a common genetic disease that predisposes patients to peripheral nerve tumors and central nervous system (CNS) abnormalities including low‐grade astrocytomas and cognitive disabilities. Using mice with glial fibrillary acidic protein (GFAP)‐targeted Nf1 loss (Nf1GFAPCKO mice), we found that Nf1−/− astrocytes proliferate faster and are more invasive than wild‐type astrocytes. In light of our previous finding that aberrant expression of the MET receptor tyrosine kinase contributes to the invasiveness of human NF1‐associated malignant peripheral nerve sheath tumors, we sought to determine whether MET expression is aberrant in the brains of Nf1 mutant mice. We found that Nf1−/− astrocytes express slightly more MET than wild‐type cells in vitro, but do not express elevated MET in situ. However, fiber tracts containing myelinated axons in the hippocampus, midbrain, cerebral cortex, and cerebellum express higher than normal levels of MET in older (≥6 months) Nf1GFAPCKO mice. Both Nf1GFAPCKO and wild‐type astrocytes induced MET expression in neurites of wild‐type hippocampal neurons in vitro, suggesting that astrocyte‐derived signals may induce MET in Nf1 mutant mice. Because the Nf1 gene product functions as a RAS GTPase, we examined MET expression in the brains of mice with GFAP‐targeted constitutively active forms of RAS. MET was elevated in axonal fiber tracts in mice with active K‐RAS but not H‐RAS. Collectively, these data suggest that loss of Nf1 in either astrocytes or GFAP+ neural progenitor cells results in increased axonal MET expression, which may contribute to the CNS abnormalities in children and adults with NF1. © 2007 Wiley‐Liss, Inc.
Adenosine receptors in colon carcinoma tissues and colon tumoral cell lines: Focus on the A3adenosine subtype
Authors: Gessi Stefania , Merighi Stefania , Varani Katia , Cattabriga Elena , Benini Annalisa , Mirandola Prisco , Leung Edward , Mac Lennan Stephen , Feo Carlo , Baraldi Stefania , Borea Pier Andrea
Published: March 2007

Adenosine may affect several pathophysiological processes, including cellular proliferation, through interaction with A1, A2A, A2B, and A3receptors. In this study we characterized adenosine receptors in human colon cancer tissues and in colon cancer cell lines Caco2, DLD1, HT29. mRNA of all adenosine subtypes was detected in cancer tissues and cell lines. At a protein levels low amount of A1, A2A, and A2Breceptors were detected, whilst the A3was the most abundant subtype in both cancer tissues and cells, with a pharmacological profile typical of the A3subtype. All the receptors were coupled to stimulation/inhibition of adenylyl‐cyclase in cancer cells, with the exception of A1subtype. Adenosine increased cell proliferation with an EC50of 3–12 µM in cancer cells. This effect was not essentially reduced by adenosine receptor antagonists. However dypiridamol, an adenosine transport inhibitor, increased the stimulatory effect induced by adenosine, suggesting an action at the cell surface. Addition of adenosine deaminase makes the A3agonist 2‐chloro‐N6‐(3‐iodobenzyl)‐N‐methyl‐5′‐carbamoyladenosine (Cl‐IB‐MECA) able to stimulate cell proliferation with an EC50of 0.5–0.9 nM in cancer cells, suggesting a tonic proliferative effect induced by endogenous adenosine. This effect was antagonized by 5‐N‐(4‐methoxyphenyl‐carbamoyl)amino‐8‐propyl‐2(2furyl)‐pyrazolo‐[4,3e]‐1,2,4‐triazolo [1,5‐c] pyrimidine (MRE 3008F20) 10 nM. Cl‐IB‐MECA‐stimulated cell proliferation involved extracellular‐signal‐regulated‐kinases (ERK1/2) pathway, as demonstrated by reduction of proliferation with 1,4‐diamino‐2,3‐dicyano‐1,4‐bis‐[2‐amino‐phenylthio]‐butadiene (U0126) and by ERK1/2 phosphorylation. In conclusion this study indicates for the first time that in colon cancer cell lines endogenous adenosine, through the interaction with A3receptors, mediates a tonic proliferative effect. J. Cell. Physiol. 211: 826–836, 2007. © 2007 Wiley‐Liss, Inc.
Stretch and interleukin 1 beta: Pro‐labour factors with similar mitogen‐activated protein kinase effects but differential patterns of transcription factor activation and gene expression
Authors: Sooranna S.R. , Engineer N. , Liang Z. , Bennett P.R. , Johnson M.R. ,   Imperial College Parturition Research Group
Published: March 2007

IL‐1beta and stretch increase uterine smooth muscle cell (USMC) prostaglandin H synthase 2 (PGHS‐2) and interleukin (IL)‐8 mRNA expression in a mitogen‐activated protein kinase (MAPK) dependent mechanism. We have tested our hypothesis that stretch and IL‐1beta activate different components of the MAPK cascade in USMC and investigated the effects of specific MAPK inhibitors on these components. Further, we have used a Jun N‐terminal kinase (JNK) and p38 activator, anisomycin, to compare the effect of differential MAPK activation on the expression of PGHS‐2, IL‐8 and oxytocin receptor (OTR) mRNA with that seen in response to stretch and IL‐1beta. Stretch, IL‐1beta and anisomycin activated similar components of the MAPK cascade and specific inhibitors of MAPK altered phosphorylation of MAPK and downstream cascade components as expected. Expression of OTR mRNA was increased by stretch and anisomycin in a MAPK‐independent manner. All three stimuli increased PGHS‐2 and IL‐8 mRNA expression in a MAPK‐dependent manner, but while the MAPK inhibitors reduced the IL‐1beta‐induced activation of activating transcription factor (ATF)‐2, liver activating protein (LAP) and c‐jun, the stretch‐induced increase in LAP was unaffected by MAPK‐inhibition and only JNK inhibition appeared to reduce c‐jun activation. These observations show that stretch, IL‐1beta and anisomycin activate the same components of the MAPK cascade, but differentially activate LAP and liver inhibitory protein (LIP) perhaps accounting for the increase in OTR by stretch and anisomycin but not IL‐1beta observed in this study. J. Cell. Physiol. 212: 195–206, 2007. © 2007 Wiley‐Liss, Inc.
EGF‐R regulates MMP function in fibroblasts through MAPK and AP‐1 pathways
Authors: Kajanne Risto , Miettinen Päivi , Mehlem Annika , Leivonen Suvi‐Katri , Birrer Michael , Foschi Marco , Kähäri Veli‐Matti , Leppä Sirpa
Published: March 2007

EGF‐R regulates cell proliferation, migration, and invasion in fibroblasts. However, the connection of EGF‐R with downstream signaling pathways mediating these responses has remained elusive. Here we provide genetic and biochemical evidence that EGF‐R‐ and AP‐1‐mediated signals are required for MMP expression and collagen contraction in fibroblasts. In EGF‐R (−/−) mouse embryonal fibroblasts, basal and inducible expression of several MMPs, including MMP‐2, ‐3, and ‐14 is impaired in comparison to wild‐type counterparts. The loss of MMP expression is associated with a suppression of EGF‐induced Erk and Jnk activities, and AP‐1 DNA‐binding and transactivation capacities. While inhibition of Jnk mainly prevents EGF‐induced phosphorylation of c‐Jun, inhibition of Erk pathway suppresses both the expression and phosphorylation of c‐Jun and c‐Fos proteins. Moreover, the expression of MMP‐3 and ‐14, and collagen contraction is partially prevented by Mek/Erk and Jnk inhibitors. However, Jnk inhibitor also suppresses cell growth independently of EGF‐R activity. The central role of AP‐1 as a mediator of EGF‐R signaling in fibroblasts is emphasized by the finding that expression of a dominant negative c‐Jun downregulates the expression of MMP‐3. Conversely, expression of a constitutively active Mek1 can induce MMP‐3 expression independently of upstream signals. The results indicate that ERK pathway and AP‐1 are downstream effectors of the EGF‐R‐mediated MMP‐3 expression and collagen contraction in fibroblasts. J. Cell. Physiol. 212: 489–497, 2007. © 2007 Wiley‐Liss, Inc.
Acute L‐glutamine deprivation compromises VEGF‐a upregulation in A549/8 human carcinoma cells
Authors: Drogat Benjamin , Bouchecareilh Marion , North Sophie , Petibois Cyril , Déléris Gérard , Chevet Eric , Bikfalvi Andréas , Moenner Michel
Published: March 2007

Tumor ischemia participates in angiogenesis and cancer progression through cellular responses to hypoxia and nutrient deprivation. However, the contribution of amino acids limitation to this process remains poorly understood. Using serum‐free cell culture conditions, we tested the impact of L‐glutamine deprivation on metabolic and angiogenic responses in A549/8 carcinoma cells. In these cells, lowering glutamine concentration modified the cell cycle distribution and significantly induced apoptosis/necrosis. Although glutamine deprivation led to a HIF‐independent increase in VEGF‐A mRNA, the corresponding protein level remained low and correlated with the inhibition of protein synthesis and activation of the GCN2/eIF2α pathway. Limitation of glutamine availability also hampers hypoxia‐ and hypoglycemia‐induced VEGF‐A protein upregulation. Thus, glutamine deprivation may have no direct effect on VEGF‐dependent angiogenesis, compared to hypoxia or to glucose deprivation, and may instead be detrimental to cancer progression by antagonizing ischemia‐induced stresses. J. Cell. Physiol. 212: 463–472, 2007. © 2007 Wiley‐Liss, Inc.
Dynamic MRI for imaging tumor microvasculature: Comparison of susceptibility and relaxivity techniques in pelvic tumors
Authors: Lankester Katharine J. , Taylor Jane N. , Stirling James J. , Boxall Jane , d'Arcy James A. , Collins David J. , Walker‐Samuel Simon , Leach Martin O. , Rustin Gordon J.S. , Padhani Anwar R.
Published: March 2007

Purpose

To assess the reproducibility of intrinsic relaxivity and both relaxivity‐ and susceptibility‐based dynamic contrast enhanced (DCE) MRI in pelvic tumors; to correlate kinetic parameters obtained and to assess whether acute antivascular effects are seen in response to cisplatin‐ or taxane‐based chemotherapy.

Materials and Methods

T1‐weighted and T2*‐weighted DCE‐MRI and basal R2* measurements were performed on three consecutive days in women with gynecological tumors. The third scan was 21.0 (range 17.3–23.5) hours after the first cycle of chemotherapy. Kinetic parameter estimates were obtained and correlated between techniques. Test‐retest reproducibility and response to treatment were assessed.

Results

Relative blood volume (rBV) and relative blood flow (rBF) correlated strongly with transfer constant (Ktrans), kep, and the initial area under the gadopentetate dimeglumine (Gd‐DTPA) concentration‐time curve (IAUGC) (all P < 0.01). The group 95% confidence interval (CI) for change was –10.8 to +12.1%; ±5.1%; –9.5 to +10.5%; ±7.5%; for Ktrans, ve, kep, and IAUGC, respectively, and ±13.6%, ±2.4%, ±11.6%, and ±11.0%, for rBV, mean transit time (MTT), rBF, and R2*, respectively. There were no significant acute changes in kinetic parameter estimates in response to treatment on group analysis, apart from a small decrease in ve.

Conclusion

The results confirm the dominant influence of flow on Ktrans in untreated gynecological tumors. There is no evidence of an acute, large magnitude antivascular effect caused by cisplatin‐ or taxane‐based chemotherapy. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Electrothermal compact model of CoolSET voltage regulators for SPICE
Authors: Górecki Krzysztof
Published: March 2007

This paper concerns the problem of modelling CoolSET voltage regulators with self‐heating taken into account. The limits of the model of this class of regulators developed by Infineon Technologies AG were analysed. A new electrothermal model of CoolSET regulators designed to analyse transient in the SPICE software was proposed. The correctness of the elaborated model was verified on the example of boost and flyback converters. A good agreement of the measurement and calculation results carried out with the use of a new model was achieved. Copyright © 2007 John Wiley & Sons, Ltd.
A decoy oligonucleotide inhibiting nuclear factor‐κB binding to the IgGκB consensus site reduces cerebral injury and apoptosis in neonatal hypoxic‐ischemic encephalopathy
Authors: Fabian Roderic H. , Perez‐Polo J. Regino , Kent Thomas A.
Published: March 2007

We examined the effect of treatment with intraventricular injection of a decoy oligonucleotide that binds and inhibits nuclear factor‐κB on cytokine expression, ICAM‐1 expression, neutrophil recruitment, apoptosis, and tissue injury in a model of neonatal hypoxic‐ischemic cerebral injury with varying degrees of hypoxia. We found a reduction of interleukin‐1β, tumor necrosis factor‐α, soluble ICAM‐1, neutrophil counts, and activity after 2 hr of hypoxia, but not with 90 min of hypoxia. By contrast, a significant reduction of apoptosis was seen in animals treated after 90 min of hypoxia but not in those treated after 2 hr of hypoxia. Overall evidence of an inflammatory response was sparse, with low levels of ICAM‐1 expression and neutrophil recruitment even in the more severe hypoxic ischemic injury. It is likely that the decoy oligonucleotide affects cerebral injury and apoptosis not through suppression of downstream elements of the inflammatory response but through other mechanisms, one of which is the reduction of transcription and synthesis of cytokines, which are known to affect other responses to cellular injury. © 2007 Wiley‐Liss, Inc.
Multiple mechanisms that prevent excessive brain inflammation
Authors: Yang Myung‐Soon , Min Kyoung‐Jin , Joe Eunhye
Published: March 2007

Inflammation of the injured brain has a double‐edged effect. Inflammation protects the brain from infection, but it aggravates injury. Furthermore, brain inflammation is considered a risk factor for neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases. Emerging evidence supports the activation of negative regulatory mechanisms during this process to prevent prolonged and extensive inflammation. The inflammatory stimulators themselves or products of inflammatory cells may induce the expression of negative feedback regulators, such as suppressor of cytokine signaling (SOCS)‐family proteins, antioxidant enzymes, and antiinflammatory cytokines. Furthermore, death of activated microglia (major inflammatory cells in the brain) may regulate brain inflammation. Astrocytes, the most abundant cells in the brain, may also act in preventing microglial overactivation. Therefore, we propose that the extent and duration of brain inflammation is tightly regulated through the cooperation of multiple mechanisms to maximize antipathogenic effects and minimize tissue damage. © 2007 Wiley‐Liss, Inc.
Luminescence chronology of late Holocene extreme hydrological events in the upper Penner River basin, South India
Authors: Thomas Puthusserry J. , Juyal Navin , Kale Vishwas S. , Singhvi Ashok K.
Published: March 2007

Field stratigraphy, sedimentology and optically stimulated luminescence (OSL) dating have been used to reconstruct the southwest monsoon variability in the semi‐arid region of southern India during the late Holocene. Facies architecture and OSL dating of the water‐lain sediment suggest prevalence of a weak hydrological regime around 3 ka. Following this, a progressive strengthening of monsoon occurred till 2 ka. After 2 ka and until 1 ka fluvial activity was nearly dormant, indicating weakening of the monsoon. Presence of high‐magnitude flood deposits, overbank sedimentation and pedogenesis during 1–0.6 ka indicate intensification of the southwest monsoon in the basin. The onset of aridity was associated with episodic storm surge events that are manifested in the pond sedimentation and localised aeolian accretion. This phase is bracketed between 0.5 ka and 0.2 ka. A renewed phase of monsoonal activity was observed in the form of floodplain aggradation between 180 and 90 years ago. In the past 70 years no significant change in the monsoon performance has been observed. Copyright © 2007 John Wiley & Sons, Ltd.
High performance liquid chromatography and capillary electrophoresis in the analysis of soybean proteins and peptides in foodstuffs
Authors: Saz José María , Marina María Luisa
Published: March 2007

The increasing interest in functional and healthy food products has promoted the use of soybean in the manufacture of foods for human consumption. Soybean basic products (soybeans, textured soybean, soybean flour, soybean protein concentrate and soybean protein isolate) as well as soybean derivatives (soybean dairy‐like products, soybean drinks with fruits, meat analogues, etc.) are commercially available. In addition, due to the interesting nutritional and functional properties of soybean proteins, they are usually employed as ingredient in the elaboration of a large number of food products such as bakery or meat products among others. In spite of the good characteristics of soybean proteins, their addition to some products is forbidden or allowed up to a certain limit. Therefore, analytical methodologies to achieve the determination of soybean proteins in foods are necessary in order to make possible adequate quality control and to prove that legal regulations controlling their addition are accomplished. However, this is not an easy task due to the diversity and complexity of the food matrices and the technological treatments to which some of these foods are submitted during their elaboration. This article presents for the first time a comprehensive review on the analytical methodologies developed using HPLC and CE to characterize soybeans and to analyse soybean proteins in meals. Moreover, the use of HPLC and CE in the characterization of soybean protein fractions and their hydrolyzates, and a study of their relationships to nutritional, functional and biomedical properties are included. Finally, the application of proteomic methodologies in soybean food technology is also reviewed.
Survival theory: tourist consumption as a beneficial experiential process in a limited risk setting
Authors: McIntyre Charles
Published: March 2007

This body of research developed over a number of individual but linked studies, predominantly carried out in the Bournemouth environs in the South Coast of England as well as on the islands of the Isle of Wight and Guernsey. The focus of these studies has been to examine the process, meaning and sought outcomes of the consumption process of individuals while on holiday. The relationship of non‐everyday setting and increased desire for interpersonal and intrapersonal significance within holiday consumption experiences are shown to be pivotal in generating a perceived developmental event for the consumer away from the routine of everyday living. An explanation for this is considered within risk‐based consumer models as well as within humanist developmental and post‐modern identity/experience choice orientations. Within holiday consumption there was found to be a high proclivity to discover, learn and reflect on the developing self, and close social unit (as well as social interactions in general) while on holiday within a non‐everyday cultural experience; with inherent alteration of consumer behaviour when in the holiday ‘state of mind’. The generally more affective, rather than cognitive, basis of tourist retail consumption is considered relating to the ‘risky’ nature of individual learning and socialisation processes and consumption behaviour within the limited risk environment of a holiday setting. In further considering risk‐based models of adventure holiday consumption, the herein proposed Survival Theory of tourist consumption offers a more general beneficial human development role (individual and social) for most tourist interactions which contrasts with much tourist literature (and popular cultural beliefs) which assumes tourism to be a selfish, destructive or harmful process within the sphere of human behaviour. Differentially across the sample, a tentative typology of tourist consumers is also proposed, with some reference to potential life‐stage association and applications to experiential‐based marketing of holidays to various consumer groups. Copyright © 2007 John Wiley & Sons, Ltd.
Preparation of Nylon 6 Nanoparticles and Nanocapsules by Two Novel Miniemulsion/Solvent Displacement Hybrid Techniques
Authors: Crespy Daniel , Landfester Katharina
Published: March 2007

Nylon 6 (polyamide 6) nanoparticles dispersed in an aqueous phase and nylon 6 nanocapsules dispersed in cyclohexane were successfully prepared via two rapid and facile techniques. These techniques combine some characteristics of the miniemulsion and the solvent displacement techniques. The principle of the first technique consists of adding nylon 6 dissolved in formic acid to an aqueous phase containing poly(vinyl alcohol) as stabilizer, while ultrasonicating the aqueous phase in order to obtain stable nanoparticles. The stability of these particles was studied over a wide range of reaction parameters, such as the temperature, the nature and concentration of the chemicals, the time and amplitude of ultrasonication. TEM micrographs of the unmodified particles revealed a morphology where the nylon 6 particles are completely wrapped by the poly(vinyl alcohol). After removal of the poly(vinyl alcohol), the nylon 6 particles were found to have a bumpy or rough morphology. The second technique allows the preparation of particles by miniemulsifying the disperse phase, a solution of nylon 6 in formic acid, in cyclohexane. Then methanol is added to the miniemulsion which immediately reacts with the formic acid. The product of the reaction, methyl formate, is evaporated and the water replaces the formic acid in the droplets, thus allowing the precipitation of the nylon 6 at the interface of the droplets resulting in the formation of nanocapsules.

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Quantitative determination of podophyllotoxin and related compounds in podophyllum species by reverse phase high performance liquid chromatography
Authors: Bastos Jairo K. , Kopycki Wlodzimierz J. , Burandt Charles L. , Nanayakkara N. P. Dhammika , McChesney James D.
Published: March 2007

A rapid sensitive and reliable reverse phase high performance liquid chromatography method was developed using a Taxsilr̀ column and gradient elution for the routine determination of podophyllotoxin and six related compounds, epipodophyllotoxin, α‐peltatin, β‐peltatin, 4′‐demethylpodophyllotoxin, podophyllotoxin‐4‐O‐glycoside, and 1,2,3,4‐dehydrodesoxypodophyllotoxin in Podophyllum extracts. The elaborated method gave well resolved peaks for these compounds with good detection response and linearity in the range 25–450 ng.