bluuebunny/crossref_metadata_2025_split huggingface dataset:
A revised Canadian perspective: progress in glacier hydrology
Authors: Scott Munro D. 
Published: January 2005

AbstractCurrent research into glacier hydrology is occurring at a time when glaciers around the world, particularly those whose hydrological regimes affect populated areas, are shrinking as they go through a state of perpetual negative annual mass balance. Small glaciers alone are likely to contribute 0·5 to 1 mm year−1 to global sea‐level rise, with associated reductions in local freshwater resources, impacts upon freshwater ecosystems and increased risk of hazard due to outburst floods. Changes to the accumulation regimes of glaciers and ice sheets may be partly responsible, so the measurement and distribution of snowfall in glacierized basins, a topic long represented in non‐glacierized basin research, is now beginning to receive more attention than it did before, aided by the advent of reliable automatic weather stations that provide data throughout the year. Satellite data continue to be an important information source for summer meltwater estimation, as distributed models, and their need for albedo maps, continue to develop. This further entails the need for simplifications to energy balance components, sacrificing point detail so that spatial calculation may proceed more quickly. The understanding of surface meltwater routing through the glacier to produce stream outflow continues to be a stimulating area of research, as demonstrated by activity at the Trapridge Glacier, Canada, and Canadian involvement in the Haut Glacier d'Arolla, Switzerland. As Canadian glacier monitoring continues to evolve, effort must be directed toward developing situations where mass balance, meltwater generation and flow routing studies can be done together at selected sites. Copyright © 2005 John Wiley & Sons, Ltd.
Evolution of microRNAs located within Hox gene clusters
Authors: Tanzer Andrea , Amemiya Chris T. , Kim Chang‐Bae , Stadler Peter F. 
Published: January 2005

AbstractMicroRNAs (miRNAs) form an abundant class of non‐coding RNA genes that have an important function in post‐transcriptional gene regulation and in particular modulate the expression of developmentally important transcription factors including Hox genes. Two families of microRNAs are genomically located in intergenic regions in the Hox clusters of vertebrates. Here we describe their evolution in detail. We show that the micro RNAs closely follow the patterns of protein evolution in the Hox clusters, which is characterized by cluster duplications followed by differential gene loss. J. Exp. Zool. (Mol. Dev. Evol.) 304B: 1–10, 2005. © 2005 Wiley‐Liss, Inc.
El Niño–southern oscillation events and associated European winter precipitation anomalies
Authors: Pozo‐Vázquez D. , Gámiz‐Fortis S. R. , Tovar‐Pescador J. , Esteban‐Parra M. J. , Castro‐Díez Y. 
Published: January 2005

AbstractThe winter precipitation anomalies in the European area have been analysed over the period 1900–98 based on the El Niño–Southern oscillation (ENSO) state. A set of winter and autumn ENSO events is first selected using the Sea‐Surface temperature (SST) data of the Niño 3 region, with the constraint that the ENSO event is well developed during the winter and autumn of study, and that it is an extreme event. Cold and warm ENSO events and periods that can be regarded as normal are selected. For the selected winter ENSO events and for the winter following the selected autumn ENSO events, composites of European winter precipitation anomalies have been obtained and compared with each other. A study of the consistency among events of the relationship between ENSO and precipitation anomalies was also carried out. The analysis of the winter precipitation anomalies based on the selected winter ENSO events shows the existence, for the European area and during La Niña events, of a statistically significant precipitation anomaly pattern with positive precipitation anomalies north of the British Isles and in the Scandinavian area and negative anomalies in southern Europe, resembling the precipitation pattern associated with the positive phase of the North Atlantic oscillation (NAO). Particularly, for the southwestern area of the Iberian Peninsula, the negative anomaly reaches 20% of the winter average precipitation. The consistency analysis shows that this precipitation pattern is not the result of a few major events, but rather that it is stable and qualitatively similar to that found during the positive phase of the NAO. A non‐linear response to ENSO is found in the eastern Mediterranean area: negative precipitation anomalies are found, having similar amplitude anomalies, both during El Niño and La Niña events. The analysis of the precipitation anomalies for the winter following the selected autumn ENSO events shows very similar results to those found for the previous analysis, thus suggesting the existence of a potential source of seasonal forecasting of European precipitation. An analysis of the sensitivity of the precipitation anomalies to the strength of the ENSO events shows that, when the strength of the ENSO increases, the magnitude of the rainfall anomalies does not change, but the area influenced and the coherence between events do increase slightly. Copyright © 2005 Royal Meteorological Society
Cover Picture: Macromol. Biosci. 1/2005
Authors: Fukushima Kazuki , Furuhashi Yukiko , Sogo Kazuaki , Miura Shigenobu , Kimura Yoshiharu 
Published: January 2005

Cover: The cover depicts the novel synthetic scheme for the stereoblock poly(lactic acid) (sb‐PLA) by solid‐state polycondensation of a stereocomplexed mixture of poly(L‐lactic acid) (PLLA), and poly(D‐lactic acid) (PDLA), having medium molecular weight. First, melt‐polycondensation of L‐ and D‐lactic acids is conducted to obtain the PLLA and PDLA, respectively. In the second step, these polymers are melt‐blended to form the stereocomplex. Then, the solid‐state polycondensation of the melt‐blend affords the sb‐PLA with high molecular weight and high melting temperature without formation of single polymer crystals of PLLA or PDLA.Further details can be found in the Full Paper by K. Fukushima, Y. Furuhashi, K. Sogo, S. Miura, and Y. Kimura* on page 21.
Preparation and Characterization of Conducting Systems based on EPDM/PE/PS‐co‐DVB/HSb
Authors: Linares Amelia , Acosta Jose L. 
Published: January 2005

AbstractSummary: Blends of different compositions were prepared from: a thermoplastic elastomer (EPDM), a low density polyethylene (PE), a polystyrene crosslinked with a small amount of divinylbenzene (PS‐co‐DVB) and an inorganic proton conductor: antimonic acid (HSb). The blends obtained were sulfonated heterogeneously with chlorosulfonic acid and were then structurally and electrically characterized by means of the following techniques: differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), crystallization kinetics under non‐isothermal conditions and complex impedance spectroscopy.Dynamic mechanical analysis for EPDM and EP‐3 blends series.magnified imageDynamic mechanical analysis for EPDM and EP‐3 blends series.
Flexural Behaviour of Fibre‐Reinforced Syntactic Foams
Authors: Karthikeyan Chedarampet S. , Sankaran Sundaram , Kishore  
Published: January 2005

AbstractSummary: Syntactic foams containing 0.9, 1.76, 2.54, 3.54 and 4.5 vol.‐% of E‐glass fibres in the form of chopped strands were processed and subjected to three‐point bending tests. The results showed that introduction of chopped strand fibres into the syntactic foam system increased the flexural strength. The values increased with the amount of fibres in the foam system except for the one containing 3.5 vol.‐% of fibres, which showed a lower value than other fibre‐reinforced systems, thereby deviating from the trend. This exception was attributed to the difference in processing route adopted for this particular fibre‐bearing foam. However, in general, the incorporation of chopped strand fibres improved the flexural behaviour of the syntactic foam system without much variation in density, thus making reinforced syntactic foams to act as better and improved core materials for sandwich applications.Fibre‐debonding and protuberance, and river pattern in a failed sample.magnified imageFibre‐debonding and protuberance, and river pattern in a failed sample.
Preparation of Nano‐Polyethylene Fibers and Floccules by Extrusion Polymerization Under Atmospheric Pressure Using the SBA‐15‐Supported Cp2ZrCl2 Catalytic System
Authors: Dong Xiaochen , Wang Li , Wang Wenqin , Jiang Guohua , Chen Ying , Zhao Zhenrong , Wang Jianjun 
Published: January 2005

AbstractSummary: Nano‐polyethylene fibers and floccules were prepared under atmospheric pressure via ethylene extrusion polymerization in suit, using the SBA‐15‐supported Cp2ZrCl2 catalytic system. The major morphology units in the samples were fibers and floccules. The diameter of the single nano‐fibers was 120–200 nm. The single nano‐fibers could aggregate to form fiber aggregates and bundles. The number of PE floccules increased with extension of polymerization time, while the melting point of PE with nano‐fibers was little higher than that of common polyethylene.SEM micrograph of the nano‐polyethylene fibers produced at a polymerization time of 60 min: micro‐fibers and floccule surface morphologies.magnified imageSEM micrograph of the nano‐polyethylene fibers produced at a polymerization time of 60 min: micro‐fibers and floccule surface morphologies.
Assembly of Clathrin Baskets
Authors: Nossal Ralph 
Published: January 2005

AbstractThe creation and internalization of small, protein‐coated vesicles is a central factor in the uptake of materials from the surfaces of eucaryotic cells through a process known as receptor mediated endocytosis. Under appropriate in vitro conditions, the principal coat component, viz., clathrin, which is found in the cell as a trimer joined at a common hub, assembles into polyhedral ‘baskets’ (‘cages’) containing pentagonal and hexagonal facets. These reconstituted cages have the appearance of miniscule soccer‐ball like structures. Their sizes vary over a finite range whose limits depend on the presence or absence of ancillary proteins (‘assembly proteins’) that are known to increase the tendency for the baskets to form. By fitting data on basket size distributions to simple energetic (thermodynamic) models, one is able to estimate mechanical properties of the clathrin constituents of the baskets and infer the role of assembly proteins in strengthening interactions between the clathrin components of the struts that constitute the edges of the baskets.
Stimulus Dependent Redistribution of Membrane Raft Cholesterol in Human Platelets
Authors: Boesze‐Battaglia Kathleen , Schimmel Richard J. , Gretzula Cheryl 
Published: January 2005

AbstractCell membranes provide a requisite dynamic interface to facilitate communication between the extracellular environment and the intracellular milieu. These membranes contain proteins that span and/or are loosely associated with the lipid bilayer. The organization of lipids and proteins components into membrane micro‐domains provides a temporal and spatial signaling platform for communication. Recently, cholesterol and sphingomyelin enriched membrane micro‐domains known as lipid rafts have been implicated in cell signaling events. In these studies we have advanced our hypothesis that stimulus dependent rearrangement of cholesterol into and out of membrane rafts provides a unique lipid–mediated regulatory mechanism. Using fluorescent derivatives of cholesterol, we have shown that membrane raft associated cholesterol was altered in response to collagen‐induced platelet aggregatory stimulation. Collagen stimulation resulted in a rapid redistribution of cholesterol from the outer to the inner membrane monolayer. The reorganization of the outer membrane monolayer resulted in a concomitant increase in outer monolayer fluidity. These studies are the first to show that membrane cholesterol was released from the exchangeable membrane raft pool in response to physiological stimuli.
Interaction of Polyunsaturated Fatty Acids with Cholesterol: A Role in Lipid Raft Phase Separation
Authors: Wassall Stephen R. , Shaikh Saame Raza , Brzustowicz Michael R. , Cherezov Vadim , Siddiqui Rafat A. , Caffrey Martin , Stillwell William 
Published: January 2005

AbstractUnequal affinity between lipids has been hypothesized to be a mechanism for the formation of microdomains/rafts in membranes. Our studies focus upon the interaction of cholesterol with polyunsaturated fatty acid (PUFA)‐containing phospholipids. They support the proposal that steric incompatibility of the rigid steroid moiety for highly disordered PUFA chains, in particular docosahexaenoic acid (DHA), provides a sensitive trigger for lateral segregation of lipids into PUFA‐rich/sterol‐poor and PUFA‐poor/sterol‐rich regions. Solid state 2H NMR and x‐ray diffraction (XRD) demonstrate that the solubility of cholesterol is reduced in 1‐palmitoyl‐2‐docosahexaenoyl‐phosphatidylethanolamine (16‐0:22:6PE) bilayers. In mixed membranes of phosphatidylethanolamine (PE) with the lipid raft forming molecules egg sphingomyelin (SM) and cholesterol, diminished affinity of the sterol for 16:0‐22:6PE relative to 1‐palmitoyl‐2‐oleoylphosphatidylethanolamine (16:0‐18:1PE) is identified by 2H NMR order parameters and detergent extraction. Phase separation of the PUFA‐containing phospholipid from SM/cholesterol rafts is the implication, which may be associated with the myriad of health benefits of dietary DHA.
Probing the Interdigitated Phase of a DPPC Lipid Bilayer by Micropipette Aspiration
Authors: Ly Hung V. , Longo Marjorie L. 
Published: January 2005

AbstractWe used micropipette aspiration of giant unilamellar vesicles to directly measure the areal expansion of gel (Lβ′) phase 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine (DPPC) lipid bilayers induced by exposure to ethanol/water mixtures. Areal expansion began in 7 vol% ethanol and increased monotonically as the concentration of ethanol was increased to 15 vol% at which point areal expansion reached a plateau of 50%. This ethanol concentration range is in good agreement with that of the interdigitated phase (LβI) of DPPC, therefore, we believe that this is the first direct measurement of the areal expansion accompanying interdigitation of gel‐phase lipids. Our observations are consistent with the presence of coexisting LβI and Lβ′ phases in ethanol concentrations between 7% and 15 vol% and 100% LβI phase in 15 vol% ethanol and higher. We observed a bimodal distribution of areal expansion (0% and 20%) induced by 7 vol% ethanol indicating that at the threshold concentration, interdigitation is induced in only a portion of DPPC vesicles. Areal expansion could not be easily reversed, consistent with kinetic trapping of the LβI phase. DPPC vesicles exposed to butanol at the known threshold and plateau concentrations for the LβI phase displayed areal expansion behavior consistent with our ethanol observations. However, the area expanded significantly faster for DPPC bilayers exposed to butanol vs. ethanol, which we attribute to enhanced partitioning of the longer‐chained butanol into the lipid headgroups. Ethanol‐induced areal expansion of DPPC bilayers was inhibited by inclusion of 10 mol% and 25 mol% cholesterol in the bilayer. However, areal expansion could be induced by application of tensions (∼8 mN/m) similar to the phenomena of interdigitation induced by high pressure. The presence of 20 vol% ethanol significantly decreased surface cohesion of DPPC bilayers containing 25 mol% cholesterol as evidenced by a decreased area compressibility modulus and lysis tension.
Calcium‐Alginate Nanoparticles Formed by Reverse Microemulsion as Gene Carriers
Authors: You Jin‐Oh , Peng Ching‐An 
Published: January 2005

AbstractNatural biopolymers are widely used in the field of drug and gene delivery. In this study, alginate nanoparticles were prepared using water‐in‐oil microemulsion as a template followed by calcium crosslinking of guluronic acid units of alginate polymer. After collected by ultracentrifugation, alginate nanoparticles were analyzed by electron microscopy to obtain the size and morphology which were varied with the ratio of water, oil, and surfactant used. To examine the potency of Ca‐alginate nanoparticles as carriers for gene delivery, GFP‐encoding plasmids were encapsulated in these nanoparticles to investigate the degree of endocytosis by NIH 3T3 cells and ensuing transfection rate. Our results showed that Ca‐alginate nanoparticles with an average size around 80 nm in diameter are very efficient gene carriers, in comparison with plasmid DNA condensed by polyethyleneimine (PEI).
Wnt signalling and the mechanistic basis of tumour development
Authors: Ilyas Mohammad 
Published: January 2005

AbstractAbnormalities in the Wnt signalling pathway are found in a wide range of cancers. The diverse origin of these malignancies implies that the contribution that disrupted Wnt signalling makes to tumourigenesis is not limited to specific tissue types and thus can be regarded as a step which is ‘generic’ to the process of carcinogenesis. In recent years, rapid progress has been made in the understanding of the Wnt signalling pathway, giving an insight into how inappropriate activation of this pathway may facilitate the neoplastic conversion of a normal cell. Furthermore, elucidation of the mechanisms that regulate Wnt signalling has led to the possibility of manipulating these mechanisms in order to down‐regulate Wnt signalling in established tumours. In this review, the Wnt signalling pathway is described. The role of aberrant Wnt signalling in tumour development is discussed together with its clinical implications for anti‐tumour therapy. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
New approaches for modelling cancer mechanisms in the mouse
Authors: Maddison Kathryn , Clarke Alan R 
Published: January 2005

AbstractMouse models of human cancer are vital to our understanding of the neoplastic process, and to advances in both basic and clinical research. Indeed, models of many of the major human tumours are now available and are subject to constant revision to more faithfully recapitulate human disease. Despite these advances, it is important to recognize that limitations do exist to the current range of models. The principal approach to modelling has relied upon the use of constitutive gene knockouts, which can often result in embryonic lethality, can potentially be affected by developmental compensation, and which do not mimic the sporadic development of a tumour expanding from a single cell in an otherwise normal environment. Furthermore, simple knockouts are usually designed to lead to loss of protein function, whereas a subset of cancer‐causing mutations clearly results in gain of function. These drawbacks are well recognized and this review describes some of the approaches used to address these issues. Key amongst these is the development of conditional alleles that precisely mimic the mutations found in vivo, and which can be spatially and tissue‐specifically controlled using ‘smart’ systems such as the tetracycline system and Cre‐Lox technology. Examples of genes being manipulated in this way include Ki‐Ras, Myc, and p53. These new developments in modelling mean that any mutant allele can potentially be turned on or off, or over‐ or under‐expressed, in any tissue at any stage of the life‐cycle of the mouse. This will no doubt lead to ever more accurate and powerful mouse models to dissect the genetic pathways that lead to cancer. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Molecular mechanisms of drug resistance
Authors: Longley DB , Johnston PG 
Published: January 2005

AbstractResistance to chemotherapy limits the effectiveness of anti‐cancer drug treatment. Tumours may be intrinsically drug‐resistant or develop resistance to chemotherapy during treatment. Acquired resistance is a particular problem, as tumours not only become resistant to the drugs originally used to treat them, but may also become cross‐resistant to other drugs with different mechanisms of action. Resistance to chemotherapy is believed to cause treatment failure in over 90% of patients with metastatic cancer, and resistant micrometastic tumour cells may also reduce the effectiveness of chemotherapy in the adjuvant setting. Clearly, if drug resistance could be overcome, the impact on survival would be highly significant. This review focuses on molecular mechanisms of drug resistance that operate to reduce drug sensitivity in cancer cells. Drug resistance can occur at many levels, including increased drug efflux, drug inactivation, alterations in drug target, processing of drug‐induced damage, and evasion of apoptosis. Advances in DNA microarray and proteomic technology, and the ongoing development of new targeted therapies have opened up new opportunities to combat drug resistance. We are now able to characterize the signalling pathways involved in regulating tumour cell response to chemotherapy more completely than ever before. This will facilitate the future development of rational combined chemotherapy regimens, in which the newer targeted therapies are used in combination with cytotoxic drugs to enhance chemotherapy activity. The ability to predict response to chemotherapy and to modulate this response with targeted therapies will permit selection of the best treatment for individual patients. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Insulin‐like growth factor ligands, receptors, and binding proteins in cancer
Authors: Foulstone E , Prince S , Zaccheo O , Burns JL , Harper J , Jacobs C , Church D , Hassan AB 
Published: January 2005

AbstractThis review aims to summarize experimental evidence supporting the role of the insulin‐like growth factor (IGF) signalling system in the progression, maintenance, and treatment of cancer. These data implicate the IGF system as an important modifier of cancer cell proliferation, survival, growth, and treatment sensitivity. The role of the IGF system in cancer should be examined in the context of the extra‐cellular and intra‐cellular signalling networks, in particular: phosphatidylinositol 3‐kinase (PI3K), protein kinase B (Akt/PKB), mammalian target of rapamycin (mTOR), and forkhead transcription factors (FOXO). This review highlights evidence derived from molecular structure and functional genetics with respect to how the extra‐cellular components of the IGF system function normally, and their subsequent modifications in cancer. The therapeutic relevance of the research evidence described is also addressed, as the challenge is to apply this knowledge to human health. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.