bluuebunny/crossref_metadata_2025 huggingface dataset:
Difference Gel Electrophoresis (
DIGE
)
Authors: Granlund Irene , Hall Michael , Schröder Wolfgang P
Published: December 2009

One of the largest challenges in proteomics today is to be able to quantify the composition and amount of proteins found in a specific cell or tissue at a defined time point. Difference gel electrophoresis (DIGE) is a gel electrophoresis‐based technique for protein quantification in complex mixtures. In DIGE the high resolution of two‐dimensional gel electrophoresis is combined with the excellent dynamic range obtained by fluorescent tag labelling of protein samples. The output of DIGE experiments provides information about how many proteins display changed expression levels on a specific treatment. In addition, proteins of interest can be excised and identified with conventional mass spectrometry techniques and further analysed by other biochemical methods.

Key concepts:

DIGE is a gel‐based technique for relative protein quantification in complex protein samples.

Experimental design, sample preparation and data analysis are all critical steps of a DIGE experiment.

Labelling of protein samples is performed by either a minimal or saturation labelling procedure.

Use of an internal standard minimizes gel to gel variation and provides increased power to the experiment.

For protein identification poststaining of gels is necessary when a minimal labelling procedure has been used.

DIGE can also be used for other applications such as native gel electrophoresis of protein complexes.

The DIGE technique is constantly being improved and continues to be an important method in functional proteomics.
Metapopulation Ecology
Authors: van Nouhuys Saskya
Published: December 2009

A metapopulation is a spatially structured population that persists over time as a set of local populations in balance between local extinction and colonization. Starting in 1969, and accelerating since the early 1990s, mathematical models of metapopulations have shown the importance of landscape connectivity and dispersal for persistence of a species or of interacting species. Some metapopulation models have been fit to empirical data. Although pure metapopulations may be rare, there are many empirical studies in which metapopulation processes, primarily local colonization and extinction, have been useful in explaining dynamics of natural and experimental systems. Metapopulation ecology is used in conservation biology and in population genetics where it influences genetic structure, the rate and trajectory of evolution and even what traits are under selection. Finally, communities of species that are distributed in a landscape potentially form metacommunity, which is a concept that shares important characteristics with metapopulations.

Key concepts:

A metapopulation is made up of semiindependent local populations.

In a metapopulation there is interplay between local and regional population dynamics.

While few species may live as metapopulations in the strict sense, many species depend on metapopulation processes. That is, a species regional persistence depends on asynchronous local dynamics and dispersal.

Predator–prey and competitive interactions may persist on a landscape scale due to metapopulation processes.
Plant Communication
Authors: Heil Martin
Published: December 2009

Plants can use volatile organic compounds released from herbivore‐infested neighbours to anticipate future enemy pressure and adjust their defensive phenotype accordingly. The most likely explanation for the evolution of this phenomenon is that plants use volatile signals for within‐plant signalling, that is, to mount a systemic response to local damage in as yet undamaged parts. The benefits of this within‐plant signalling are obvious and the same remains true for the receivers of cues that allow them to anticipate upcoming enemy attack. By contrast, no study has demonstrated that the emitting plant benefits from warning its neighbours. The question remains open whether this signalling phenomenon represents communication or, rather, eavesdropping.

Key concepts:

Plants are sessile organisms and require phenotypic plasticity to cope with a rapidly changing and in part unpredictable environment.

Plants express induced systemic resistance to herbivores and pathogens.

Plants can anticipate future enemy attack by perceiving cues that are released from damaged neighbours.

Volatile organic compounds play multiple roles in the resistance of plants to pathogens and herbivores.

Communication is defined differently, making it difficult to clearly apply the term ‘plant communication’ to signalling between plants.

Volatile organic compounds serve as signals exchanged among plants and carnivores and likely also serve as plant hormones.
Immunity, Granzymes and Cell Killing
Authors: Waterhouse Nigel J , Susanto Olivia , Sedelies Karin A , Trapani Joseph A
Published: December 2009

Cytotoxic lymphocytes protect us from viral infection and cancer by directly killing tumour cells, or cells harbouring a virus. One crucial mechanism they use to kill their targets is known as the ‘granule exocytosis’ pathway. This involves secretion of a potent mix of toxins, resulting in transfer of granule proteases (granzymes) from the killer cell into the target cell, where they cleave various intracellular substrates to activate diverse signalling pathways to cell death. Access to the target cell cytosol depends on a pore‐forming protein toxin, perforin. Because granule exocytosis is a crucial part of the body's natural defence against such dangerous cells, understanding how granzymes kill their targets may yield novel strategies and identify new molecular targets for anticancer or antiviral therapies.

Key Concepts:

The critical role of cytotoxic T lymphocytes and natural killer cells is to eliminate abnormal cells, thereby defending higher organisms against intracellular infection.

An important additional function of cytotoxic lymphocytes also encompasses their role in surveillance against transformed cells.

Perforin and granzymes synergize to kill target cells. Perforin is critical to this process and its role is to enable granzyme proteases to access key substrates in the target cell.

Granzyme B is the most potent pro‐apoptotic granzyme, as it shares with caspases the capacity to cleave its substrates after key aspartate residues.

Cytotoxic lymphocytes have developed a plethora of different signalling pathways to bring about target cell death. This is critically important as viruses are adept at blocking cell death to maximize their opportunity for viral replication and spread to uninfected cells.

Apart from inflicting cell death, granzymes have additional functions such as directly interfering with viral replication and in cytokine processing, leading to amplification of the inflammatory response to pathogens.

Dysregulation of cytotoxic T cell function can sometimes lead to adverse effect such as autoimmune tissue damage.
Platypus Genome Provides Unique Insights into Early Mammalian Evolution and Monotreme Biology
Authors: Grützner Frank
Published: December 2009

Whole‐genome sequence has been available from species of two mammalian subclasses (marsupials and eutherian mammals) but not monotreme mammals. Monotremes (platypus and echidna) are the most distant living mammalian relatives to humans, which diverged more than 160 million years ago. In addition to the key phylogenetic position they also feature fascinating biology (e.g. egg‐laying, venom, electroreception and multiple sex chromosomes). The recently completed draft genome of the duck‐billed platypus fills this gap in comparative genomics, and provides unique insights into the evolution of mammalian genes, regulatory mechanisms and nonprotein‐coding sequences. The platypus genome project also revealed first insights into the gene sets underlying the unique biology of monotremes.

Key concepts:

Monotremes are the most basal mammalian group of egg‐laying mammals (including platypuses and echidnas) that provide unique insights into the evolution of mammals.

Mammals are a group of animals, which share fur, mammary glands and a placenta. This group includes eutheria (e.g. humans and mice), metatheria (e.g. kangaroos) and prototheria (egg‐laying platypus and echidna).

Genomics describes the analysis of sequences of whole genomes.

In Comparative Genomics information on genomes of various species is compared to provide insights into the evolutionary change of different aspects of genomes (e.g. chromosomes, genes, regulatory regions and repeats).

Rapid progress in large‐scale DNA sequencing technology allows Genome Projects to determine the sequence of entire genomes of a rapidly growing number of organisms.

Genome composition describes basic characteristics of whole genomes including size, estimated gene number, repeat content and base pair composition.

Genome analysis provides a prediction of most of the genes in a genome, which reveals presence or absence of genes and gives insights into function and evolution of typical characteristics of the species.

All genetic information generated by publicly funded genome projects or published by individual researchers are deposited in Genome databases (also called genome browsers like UCSC or ENSEMBL) which allow searches and comparisons of billions of sequences of hundreds of species.
Processing of Bulk Metallic Glass
Authors: Schroers Jan
Published: December 2009

Bulk metallic glass (BMG) formers are multicomponent alloys that vitrify with remarkable ease during solidification. Technological interest in these materials has been generated by their unique properties, which often surpass those of conventional structural materials. The metastable nature of BMGs, however, has imposed a barrier to broad commercial adoption, particularly where the processing requirements of these alloys conflict with conventional metal processing methods. Research on the crystallization of BMG formers has uncovered novel thermoplastic forming (TPF)‐based processing opportunities. Unique among metal processing methods, TPF utilizes the dramatic softening exhibited by a BMG as it approaches its glass‐transition temperature and decouples the rapid cooling required to form a glass from the forming step. This article reviews crystallization processes in BMG former and summarizes and compares TPF‐based processing methods. Finally, an assessment of scientific and technological advancements required for broader commercial utilization of BMGs will be made.
Synthesis, characterization, electrochemical, catalytic and antimicrobial activity studies of hydrazone Schiff base ruthenium(II) complexes
Authors: Thilagavathi N. , Manimaran A. , Padma Priya N. , Sathya N. , Jayabalakrishnan C.
Published: December 2009

Four tridentate O, N, O donor Schiff base ligands were prepared by the reaction of substituted benzhydrazide and appropriate salicylaldehyde. The complexes of these ligands were synthesized by refluxing the ligands with ruthenium(II) starting complexes of the formula [RuHCl(CO)(EPh3)2B] in benzene, where E = P or As; B = PPh3 or AsPh3 or pyridine. The newly synthesized complexes were characterized by elemental, spectral (FT‐IR, UV and NMR) and electrochemical data. On the basis of the above studies, an octahedral structure has been proposed for all the complexes. The catalytic efficiency of the complexes in aryl–aryl couplings and oxidation of alcohols was examined and their inhibition activity against the growth of the micro‐organisms was also examined. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of nanoclay on the morphology and properties of poly(methyl methacrylate)/high‐density polyethylene blends
Authors: Mallick Sumana , Dhibar Anup K. , Khatua B. B.
Published: December 2009

The effect of nanoclay on the morphology and properties of poly(methyl methacrylate) (PMMA)/high‐density polyethylene (HDPE) blends was studied. A scanning electron microscopy study of the PMMA/HDPE (70/30 w/w) blends with nanoclay indicated a reduction in the average domain sizes of the dispersed HDPE phase and, hence, a better extent of mixing compared to that of the blends without any nanoclay. An X‐ray diffraction study and transmission electron microscopy revealed the localization of intercalated nanoclay in the PMMA matrix of the PMMA/HDPE (70/30 w/w) blend. However, the same effect of clay was not observed in the PMMA/HDPE (30/70 w/w) blend when HDPE became the matrix. In the PMMA/HDPE (30/70 w/w) blend, the addition of nanoclay increased the domain size of the dispersed PMMA domains by preferential location of the clays inside the PMMA domains. The addition of polyethylene‐grafted maleic anhydride in both compositions of the PMMA/HDPE blend effectively reduced the domain size of the disperse phases in the blend. However, the presence of clay increased the tensile strength and storage modulus of the PMMA/HDPE blends in both blend compositions. Thus, in the PMMA/HDPE blend, the clay platelets acted as a effective compatibilizer as long as they were dispersed mainly in the matrix phase. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Morphologies and electrical properties of electrospun poly[(R)‐3‐hydroxybutyrate‐co‐(R)‐3‐hydroxyvalerate]/ multiwalled carbon nanotubes fibers
Authors: Chan Kok Ho Kent , Wong Siew Yee , Tiju Wuiwui Chauhari , Li Xu , Kotaki Masaya , He Chao Bin
Published: December 2009

Electrospinning process was used to fabricate fine fibers from poly[(R)‐3‐hydroxybutyrate‐co‐(R)‐3‐hydroxyvalerate] embedded with multiwalled carbon nanotubes (MWCNTs). Rotating disc collector was used to provide additional drawing force to stretch and align both the embedded MWCNTs and electrospun fibers themselves. Morphological observation revealed MWCNTs aligned to the fiber axis and protruding from the surface. To understand the electrical properties of the fiber, a single‐composite fiber has been deposited on a substrate, across multiple electrodes. Electrical conductivity of the single‐electrospun fiber with low MWCNT content of 0.2 wt % was calculated to be in a remarkable magnitude of about 2.07 Sm−1. Electrical current flow spanning the fiber length of 1400 μm indicates that the presence of an interconnected network of MWCNTs exists within the fiber. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation of functionalized Kraft lignin beads
Authors: Saidane Dorra , Barbe Jean‐Christophe , Birot Marc , Deleuze Hervé
Published: December 2009

Kraft lignin from black liquor wastes have been converted into epichlorohydrin‐crosslinked beads by inverse suspension polymerization. A careful control of the different parameters allowed the preparation of spherical beads with a relatively narrow diameter size distribution. The obtained beads, without permanent porosity, swell well in hydroalcoholic media. Grafting of the sulfonylhydrazine moiety using a two‐step route was further performed to apply them to carbonyl compounds scavenging. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Thermal properties of acrylonitrile/itaconic acid polymers in oxidative and nonoxidative atmospheres
Authors: Yu Meijie , Wang Chengguo , Zhao Yaqi , Zhang Min , Wang Weiqiang
Published: December 2009

Thermal stabilization of polyacrylonitrile (PAN) fibers is an indispensable process in the manufacture of carbon fibers. The effects of acidic comonomers on the thermal properties of PAN have attracted much attention because of their importance in the fibers spinning and heat treatment process. In this study, oxidative and nonoxidative atmospheres are adopted in differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) test to disclose the key effects of oxygen on the thermal properties of PAN/itaconic acid (IA) polymers. The DSC results under oxidative atmosphere are consistence to the reports by previous researchers: the exothermic curves of copolymers containing 0.6 wt % and 1.0 wt % IA exhibit lower initiation temperature and more broaden shapes than that of PAN homopolymer, indicating that IA facilitates both cyclization and oxidation reactions. However, copolymers containing the same content of IA shows no apparent improving effect on the thermal properties under inert atmosphere, which has not been mentioned in the published literature. TGA indicates that oxygen remarkably increases the thermal stability of AN/IA copolymers structure, and will bring high carbon yield in the eventual carbon fibers. The influential mechanisms of oxidative and nonoxidative atmospheres on thermal stabilization reactions of PAN were discussed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Prepared for challenges: The importance of a professional and institutional ethical identity
Authors: Anderson Sharon K. , Lujan Linda , Hegeman Diane L.
Published: December 2009

Anderson, Harbour, and Davies (2007) have proposed a framework of professional identity development for community college leaders. We further this discussion by introducing the idea of “institutional ethical identity” and offer suggestions for how leaders and constituents can work together to build a shared ethical identity on the community college campus.
Diversity‐affirming ethics and critical epistemology: Institutional decision making in community colleges
Authors: Aragon Antonette , Brantmeier Edward J.
Published: December 2009

This chapter raises awareness about potential approaches to institutional decision making in community colleges that embody diversity‐affirming ethics and a critical epistemological orientation that promotes social justice.
An inquiry process for individual and institutional ethics
Authors: Farrell Patricia L.
Published: December 2009

This chapter introduces a process for inquiry that institutions can use to dialogue about institutional ethics. Double‐loop learning involves questioning, reflecting on, and coming to a common understanding of institutional norms, values, policies, and ethical codes.
Tuning the Functional Properties of Metal Complexes Containing Polytopic Heteroaromatic Nitrogen Ligands
Authors: Pettinari Claudio , Masciocchi Norberto , Pandolfo Luciano , Pucci Daniela
Published: December 2009

The preparation, characterization, and optimization of the functional properties of mono‐ and polynuclear coordination complexes containing heteroaromatic nitrogen ligands are discussed here, taking the advantage of numerous studies performed in our laboratories on exploring a variety of different metal ions and polytopic ligands. We highlight how very minor changes in connectivity, composition, and polarity of the molecular entities employed in the self‐assembly steps may significantly affect the structural, thermal, sorptive, magnetic, and mesomorphic behavior of the resulting materials. Examples from three different classes are included: 1) pyrazolate‐based polynuclear coordination compounds, 2) homoleptic and heteroleptic coordination polymers, and 3) 2,2′‐bipyridine metal‐based liquid crystals.
Diverse interneuron populations have highly specific interconnectivity in the rat piriform cortex
Authors: Gavrilovici Cezar , D'Alfonso Sabrina , Poulter Michael O.
Published: December 2009

Previous studies have suggested that the patterns of innervation and high interconnectivity of the piriform cortex (PC) provide for strong olfactory hippocampal memory; however, these same attributes may create high seizurogenic tendencies. Thus, understanding this wiring is important from a physiological and pathophysiological perspective. Distinct interneurons expressing differing calcium binding proteins (CBPs), parvalbumin (PV), calbindin (CB), and calretinin (CR), have been shown to exist in PC. However, a comprehensive examination of the distribution and innervation patterns of these neurons has not been done. Thus the purpose of this study was to combine the analysis of the CBP cell localization with analysis of their innervation patterns. Each type was differentially localized in the three layers of the PC. Only CR‐positive neurons were found in layer 1. PV and CB are coexpressed in layers 2–3, most expressing both PV and CB. A morphological estimate of the dendritic extent for each subtype showed that PV and PV/CB cells demonstrated equally wide, horizontal and vertical arborizations, whereas CB cells had wide horizontal and restricted vertical arborizations. CR cells had restricted horizontal and very long vertical arborizations. Postsynaptic morphological targeting was also found to be specific, namely, PV+ and PV/CB+ nerve terminals (NTs) innervate perisomatic regions of principal cells. CR+ NTs innervate only dendrites of principal cells, and CB+ NTs innervate both somata and dendrites of principal cells. These data show highly complex innervation patterns for all of the CBP interneurons of the PC and form a basis for further studies in the plasticity of this region. J. Comp. Neurol. 518:1570–1588, 2010. © 2009 Wiley‐Liss, Inc.
Organization of the marmoset cerebellum in three‐dimensional space: Lobulation, aldolase C compartmentalization and axonal projection
Authors: Fujita Hirofumi , Oh‐Nishi Arata , Obayashi Shigeru , Sugihara Izumi
Published: December 2009

The cerebellar cortex is organized by transverse foliation and longitudinal compartmentalization. Although the latter, which is recognized through the molecular expression in subsets of Purkinje cells (PCs), is closely related to topographic axonal projection and represents functional divisions, the details have not been fully clarified in mammals other than rodents. Therefore, we examined folial and compartmental organization of the marmoset cerebellum, which resembles the macaque cerebellum, and compared it with that of the rodent cerebellum by aldolase C immunostaining, three‐dimensional reconstruction of the PC layer, and labeling of olivocerebellar and corticonuclear projections. Longitudinal stripes of different aldolase C expression intensities separated the entire cerebellar cortex into multiple compartments. Lobule VIIAb–d was equivalent to rodent lobule VIc in that it contained a transverse gap in the cortical layers and served as the rostrocaudal boundary for compartments and axonal branching. Olivocortical and corticonuclear projection patterns in major compartments indicated that the compartmental organization in the marmoset cerebellum was generally equivalent to that in the rodent cerebellum, although two compartments were missing in the pars intermedia and several compartments that have not been seen in rodents were recognized in the flocculus, nodulus, and the most lateral hemisphere. Reconstruction showed that the paraflocculus and flocculus were formed by a single longitudinal sheet, the axis of which was parallel to the aldolase C compartments, PC dendrites, and olivocerebellar climbing fiber distribution. The results indicate that molecular compartmentalization in the marmoset cerebellum reflected both the common fundamental organization of the mammalian cerebellum and species‐dependent differentiation. J. Comp. Neurol. 518:1764–1791, 2010. © 2009 Wiley‐Liss, Inc.
Heat shock protein 25 expression and preferential Purkinje cell survival in the lurcher mutant mouse cerebellum
Authors: Duffin C.A. , McFarland R. , Sarna J.R. , Vogel M.W. , Armstrong C.L.
Published: December 2009

The spatial organization of the mouse cerebellum into transverse zones and parasagittal stripes is reflected during the temporal progression of Purkinje cell death in the Lurcher mutant mouse (+/Lc). Neurodegeneration in the +/Lc mutant is apparent by the second postnatal week and is initially seen in all four transverse zones: the anterior (lobules I–V), central (lobules VI, VII), posterior (lobules VIII, dorsal IX), and nodular (ventral lobule IX and lobule X) zone. However, from postnatal day (P)25–P36, Purkinje cell loss proceeds more rapidly in the anterior zone, followed by the posterior and central zones, and is significantly delayed in the nodular zone. Coronal sections through the +/Lc cerebellum reveal that surviving Purkinje cells are restricted to the paraflocculus/flocculus and the nodular zone and could be detected as late as P146 (∼5 months). Within this region, the pattern of preferentially surviving calbindin‐immunoreactive Purkinje cells reflects the expression of the constitutively expressed small heat shock protein HSP25 in the wild‐type cerebellum. Although the role of constitutively expressed HSP25 in the wild‐type cerebellum is not clear, it appears to play a neuroprotective role in the flocculonodular region of the +/Lc mutant cerebellum as the percentage of surviving Purkinje cells that are HSP25‐immunopositive significantly increases over time. J. Comp. Neurol. 518:1892–1907, 2010. © 2009 Wiley‐Liss, Inc.
Preparation and Reactivity of Mono‐ and Dinuclear Derivatives of Niobium and Tantalum Pentahalides with Alkyl Aryl Ethers
Authors: Marchetti Fabio , Pampaloni Guido , Zacchini Stefano
Published: December 2009

The niobium and tantalum pentahalides MX5 (X = F, Cl) react with a series of bifunctional alkyl aryl ethers in a 2:1 ratio, resulting in formation of the dinuclear species (MX5)2[μ‐κ2‐(O–O)] [2a–h, 3a–d; O–O = 1,4‐(OMe)2C6H4, 1,4‐(OMe)2‐2,5‐C6H2F2, 1,3‐(OMe)2C6H4, PhO(CH2)2OPh]. The mononuclear complexes MX5(L) [L = κ1‐1,4‐(OMe)2C6H4, X = F, M = Nb, 4a; L = κ2‐1,3‐(OMe)2C6H4, X = Cl, M = Ta, 4c; L = MeOC6H5, X = F, M = Nb, 4d; L = MeOC6H5, X = Cl, M = Nb, 4e] have been prepared by 1:1 molar reactions of MX5 with the appropriate reactant. Alternatively, NbCl5[κ1‐1,4‐(OMe)2C6H4] (4b) has been obtained upon addition of acetone to (NbCl5)2[μ‐κ2‐1,4‐(OMe)2C6H4] (2b). The aryloxide complexes TaBr4[κ1‐OC6H4(4‐OMe)] (5a), NbCl4[κ1‐OC6H3(Me)(4‐OEt)] (5b) and TaX4[κ2‐OC6H4(2‐OMe)] (X = Cl, 7a; X = Br, 7b) form an admixture with equimolar amounts of alkyl halide by addition of dialkoxyarenes to MX5 (X = Cl, Br), as result of room‐temperature C–O bond cleavage. Differently, the ionic species [MF4(κ2‐O–O)2][M2F11] [O–O = 1,2‐(OMe)2C6H4, M = Nb, 6a; O–O = 1,2‐(OMe)2C6H4, M = Ta, 6b; O–O = 1,2,4‐(OMe)3C6H3, M = Nb, 6c] are produced cleanly by treating ortho‐dimethoxyarenes with MF5 in the opportune stoichiometry. All the products described herein were obtained selectively in good to excellent yields and were characterized by spectroscopic and analytical techniques. Moreover, the molecular structure of 2b was elucidated by an X‐ray diffraction study.
Effect of antioxidant‐enriched foods on plasma: Phospholipid molecular species composition
Authors: Pacetti Deborah , Lucci Paolo , Boselli Emanuele , Frega Natale G.
Published: December 2009

The dietary supplementation with antioxidant‐enriched foods was evaluated for the phospholipid (PL) class and molecular species composition of human plasma. Twenty healthy subjects were supplied with α‐tocopherol (13.7 mg/day) and coenzyme Q10 (19.4 mg/day) by enriched milk, a dessert, fruit juice and yogurt for 21 days. Phosphatidylcholine (85.2%) and sphingomyelin (10.9%) were the main PL in all samples. Differences among the contents of PL classes were not found. However, principal component analysis showed differences in the PL molecular species 2 h after the mid‐morning snack. An increase of phosphatidylinositol (PI) containing stearic/arachidonic (on average from 42.5 to 47.0%), stearic/docosahexaenoic (3.2 vs. 4.9%), oleic/arachidonic and palmitic/docosapentaenoic acid (2.4 vs. 3.7%) was observed. The decreasing species of PI were palmitic/linoleic (5.7 vs. 4.3%), palmitic/oleic (8.1 vs. 6.9%) and stearic/linoleic acid (17.4 vs. 13.8%) after the mid‐morning snack. Phosphatidylethanolamine (PE) species showed an opposite trend with respect to PI: A decrease was registered for stearic/arachidonic (17.0 vs. 15.8%), stearic/docosahexaenoic (7.2 vs. 4.9%), oleic/arachidonic and palmitic/docosapentaenoic acid (5.8 vs. 4.8%); an increase was observed for the PE species containing oleic/linoleic (5.5 vs. 7.5% on average after the mid‐morning snack), stearic/linoleic (19.7 vs. 23.4%) and stearic/oleic acid (11.4 vs. 13.9%).
Synthesis and Screening of C1‐Substituted Tetrahydroisoquinoline Derivatives for Asymmetric Transfer Hydrogenation Reactions
Authors: Chakka Sai Kumar , Andersson Pher G. , Maguire Glenn E. M. , Kruger Hendrik G. , Govender Thavendran
Published: December 2009

Tetrahydroisoquinoline (TIQ) derivatives exhibit good biological activity. However, utilization of TIQ compounds in asymmetric catalysis is limited. This paper presents a series of TIQ derivatives in asymmetric transfer hydrogenation (ATH) reactions. Chiral TIQ amino alcohol ligands were synthesized and screened for the ATH reaction of aromatic ketones. The effect of a cis‐ and trans‐phenyl substitution at the C1 position on the ligand backbone was investigated both experimentally and computationally. The results showed that the trans orientation on the TIQ scaffold yields higher turnover rates with a selectivity of 94 % ee obtained at room temperature with an Ru complex. The cis isomer results in a high turnover rate with no selectivity. The trans isomer gave 99 % ee at lower temperatures. Furthermore, it was observed that substitution at the C3‐α position results in a drop of the enantioselectivity and the reactivity of the catalyst.
Reinterpretation of an archaeological pebble culture from the Middle Mekong River valley, Cambodia
Authors: Demeter Fabrice , Patole‐Edoumba Elise , Duringer Philippe , Bacon Anne‐Marie , Sytha Pheng , Bano Maxim , Laychour Vin , Cheangleng Mao , Sari Vân
Published: December 2009

In 1963, E. Saurin and J.‐P. Carbonnel discovered the Sre Sbov site on an alluvial terrace of the Mekong River in central Cambodia. Saurin described a lithic typology dating to the Lower/Middle Pleistocene from this site. Although the original lithic assemblage has been lost, this typology has been used continuously as a reference by Southeast Asian prehistorians. In 2007, a Khmer–French team conducted excavations at Sre Sbov that yielded numerous pebbles and cobbles showing apparently convincing handmade removals, as Saurin had previously described. However, an in‐depth study of this assemblage, combined with a geological survey of the area, led to the conclusion that the stones were, in fact, of natural origin, and that for this reason their typology should be disregarded. Using satellite imagery and geological surveys, we explain how such a misinterpretation may have occurred and define a “buffer zone,” corresponding to the maximal extent of the proto‐Mekong River, where fluvially reworked pebbles and cobbles resembling artifacts may be recovered. © 2009 Wiley Periodicals, Inc.
The accumulation of Stone Age lithic artifacts in rock fragment mulches in northern Ethiopia
Authors: Aerts Raf , Finneran Niall , Haile Mitiku , Poesen Jean
Published: December 2009

Lithic artifacts buried in the soil profile may be transported to the surface during tillage‐induced kinetic sieving, differential erosion, or swell–shrink cycles of clays and become part of a rock fragment mulch. Archaeologically, these manifestations are recognized as surface scatters. Although artifacts at the soil surface are difficult to relate to the local stratigraphic context, surface assemblages may provide information on lithic industries and the archaeological significance of sparsely explored regions. Through in situ investigation of surface material in 60 1 × 1 m2 plots in the Tembien district in the northern Ethiopian highlands, we show that rock fragment mulches can contain a significant number of lithic artifacts and we provide evidence for mid‐Pleistocene occupation of a site. Considering that severe rill and gully erosion may be a threat to the archaeological heritage and that well‐dated African Middle Stone Age sites are rare, we conclude that the region deserves more attention for archaeological research. © 2009 Wiley Periodicals, Inc.
First Example of Diterpenoids from 14,15‐Cyclopimarane in the Roots of Linum usitatissimum
Authors: Sun Jian‐Long , Deng An‐Jun , Li Yan , Li Zhi‐Hong , Chen Hui , Qin Hai‐Lin
Published: December 2009

Chemical investigation of the roots of Linum usitatissimum led to the isolation and characterization of a new diterpenoid, named usitatissimin A (1), together with four known compounds. The structure of the new compound was established by spectroscopic methods, including X‐ray crystallographic diffraction analysis that confirmed the relative configuration of 1. This is the first example of a diterpenoid with a novel 6/6/6/3‐membered ring system of 14,15‐cyclopimarane. In addition, usitatissimin A showed pronounced hepatoprotective activity against D‐galactosamine‐induced toxicity in WB‐F344 rat hepatic epithelial stem‐like cells.
A Novel Construction of 2‐Benzazepine Scaffold Based on TiCl4‐Mediated Tandem Mannich Reaction–Aromatic Electrophilic Substitution
Authors: Li Liangxi , Li Zhiming , Wang Quanrui
Published: December 2009

A novel construction of 2‐benzazepine derivatives based on TiCl4‐mediated tandem Mannich reaction of electron‐rich benzyl iminium ions with alkenyl ethers and Friedel–Crafts‐type alkylation is described. The protocol is amenable to provide the tricyclic furo[3,2‐d][2]benzazepine and pyrano[3,2‐d][2]benzazepine derivatives, respectively, with 2,3‐dihydrofuran or 3,4‐dihydro‐2H‐pyran as the substrates.
SWAT‐simulated hydrological impact of land‐use change in the Zanjanrood basin, Northwest Iran
Authors: Ghaffari Golaleh , Keesstra Saskia , Ghodousi Jamal , Ahmadi Hassan
Published: December 2009

Understanding the impacts of land‐use changes on hydrology at the watershed scale can facilitate development of sustainable water resource strategies. This paper investigates the hydrological effects of land‐use change in Zanjanrood basin, Iran. The water balance was simulated using the Soil and Water Assessment Tool (AVSWAT2000). Model calibration and uncertainty analysis were performed with sequential uncertainty fitting (SUFI‐2). Simulation results from January 1998 to December 2002 were used for parameter calibration, and then the model was validated for the period of January 2003 to December 2004. The predicted monthly streamflow matched the observed values: during calibration the correlation coefficient was 0·86 and the Nash–Sutcliffe coefficient 0·79, compared with 0·80 and 0·79, respectively, during validation. The model was used to simulate the main components of the hydrological cycle, in order to study the effects of land‐use changes in 1967, 1994 and 2007. The study reveals that during 1967 a 34·5% decrease of grassland with concurrent increases of shrubland (13·9%), rain‐fed agriculture (12·1%), bare ground (5·5%) irrigated agriculture (2·2%), and urban area (0·7%) led to a 33% increase in the amount of surface runoff and a 22% decrease in the groundwater recharge. Furthermore, the area of sub‐basins that was influenced by high runoff (14–28 mm) increased. The results indicate that the hydrological response to overgrazing and the replacing of rangelands (grassland and shrubland) with rain‐fed agriculture and bare ground (badlands) is nonlinear and exhibits a threshold effect. The runoff rises dramatically when more than 60% of the rangeland is removed. For groundwater this threshold lies at an 80% decrease in rangeland. Copyright © 2009 John Wiley & Sons, Ltd.
Northern Hemisphere geography of ice‐covered rivers
Authors: Bennett K. E. , Prowse T. D.
Published: December 2009

Although river ice is a major component of the cryosphere and is particularly important to many river processes, including extreme events, its full geographical coverage has never been documented. Recognizing that the freeze‐up and break‐up of river ice is closely linked to the timing of 0 °C air temperatures, this study analyses the spatial extent of river networks relative to the location of three 0 °C isotherm periods. These were defined to represent a suite of ice‐affected conditions that would be experienced for 6, 3 or 0·5 month periods, the briefest interval possibly leading only to a very thin and transient ice cover or simply border/frazil ice formation. Four different GIS databases were used to represent the river networks. The percentages of the total Northern Hemisphere land mass (average river network) influenced by cold temperatures conducive to ice formation were 52, 45 and 25 (56, 47 and 28), respectively. The related southern position of the isotherms ranged from 33°N, 35°N and 50°N in central North America to a nearly consistent 27°N for Eurasia, reflecting the influence of the high‐elevation central plateau region. Also identified are the lengths of major rivers that fall within the three 0 °C isotherm boundaries. Included are some of the world's largest rivers including the Lena, Mackenzie, Ob, Yellow, Yukon and Yenisey rivers, although their percentage of ice‐affected coverage varied for the three isotherm periods from a consistent 100% for the Lena and Yukon rivers to as little as 23% at the 6‐month interval for the Yellow River. Copyright © 2009 Her Majesty the Queen in right of Canada. Published by John Wiley & Sons, Ltd.
Pattern of declining hemoglobin concentration before cancer diagnosis
Authors: Edgren Gustaf , Bagnardi Vincenzo , Bellocco Rino , Hjalgrim Henrik , Rostgaard Klaus , Melbye Mads , Reilly Marie , Adami Hans‐Olov , Hall Per , Nyrén Olof
Published: December 2009

Although anemia is widely considered an early sign of malignant disease, little is known about the pattern of hemoglobin decline before diagnosis. As an approach to understanding the duration of the preclinical phase of different types of malignant diseases, we investigated prediagnostic hemoglobin concentration changes in a large cohort of blood donors. Using a nested case‐control design, we analyzed a population‐based cohort comprising 1.1 million Scandinavian blood donors with complete follow‐up through record linkage to population and cancer registers. A total of 16,375 cancer cases were identified, for whom we selected 161,995 controls. We used conditional logistic regression to estimate the risk of cancer in relation to hemoglobin concentration during the 5 years preceding the cancer diagnosis. Hemoglobin concentration decline began already 3 years before diagnosis of stomach cancer, multiple myeloma, and lymphatic leukemia; 2 years before diagnosis of small intestinal and colon cancer as well as of Hodgkin lymphoma. A decline was evident during the last year for non‐Hodgkin lymphoma and myeloid/monocytic leukemia, whereas no change was found for cancer of the esophagus, breast or prostate. In conclusion, in this study, we have demonstrated that the pattern of declining hemoglobin concentration before cancer diagnosis varies considerably between malignancies without being a suitable screening tool for any of them. For some malignancies, however, the long duration of hemoglobin decline before clinical diagnosis suggests a substantial lead‐time with systemic effects, during which earlier diagnosis should be achievable by emerging diagnostic tools.
HIF‐1α is an unfavorable determinant of relapse in gastric cancer patients who underwent curative surgery followed by adjuvant 5‐FU chemotherapy
Authors: Nakamura Jun , Kitajima Yoshihiko , Kai Keita , Hashiguchi Kazuyoshi , Hiraki Masatsugu , Noshiro Hirokazu , Miyazaki Kohji
Published: December 2009

Among several chemotherapeutic agents, 5‐fluorouracil (5‐FU) has been widely used as a key drug in adjuvant chemotherapy for gastric cancer. However, no reliable marker, which predicts the response to 5‐FU in an adjuvant setting, has been identified. Hypoxia‐induced drug resistance, via upregulation of HIF‐1α, is a major obstacle in the development of effective cancer therapy. However, few clinical studies have so far assessed the relationship between the HIF‐1α expression and the chemo‐resistance of gastric cancer patients in an adjuvant setting. We established 2 HIF‐1α knockdown gastric cancer cell lines in order to clarify the role of HIF‐1α in chemo‐resistance against 5‐FU. Furthermore, expression of HIF‐1α was immunohistochemically assessed in 91 resected specimens. Sixty‐four of 91 patients received 5‐FU adjuvant chemotherapy after surgery. HIF‐1α expression was associated with the significantly shorter relapse‐free survival and disease‐specific survival in the 64 patients of adjuvant group (p = 0.026, 0.014, respectively), but not in the 27 of surgery group. Multivariate analysis showed that HIF‐1α was an independent risk factor for relapse in 64 patients in the adjuvant group (p = 0.029). In conclusion, the current study confirmed, for the first time that HIF‐1α expression is an independent risk factor for relapse in high‐risk gastric cancer patients who underwent curative surgery followed by adjuvant 5‐FU chemotherapy. A favorable effect of 5‐FU might therefore be expected in patients that do not express HIF‐1α, whereas, other types of chemotherapy or additional treatments, such as HIF‐1α inhibitors, should be considered in patients that do express HIF‐1α.
Coarse‐grained model of nucleic acid bases
Authors: Maciejczyk Maciej , Spasic Aleksandar , Liwo Adam , Scheraga Harold A.
Published: December 2009

Atomistic simulations of nucleic acids are prohibitively expensive and, consequently, reduced models of these compounds are of great interest in the field. In this work, we propose a physics‐based coarse‐grained model of nucleic‐acid bases in which each base is represented by several (3–5) interaction centers. van der Waals interactions are modeled by Lennard‐Jones spheres with a 12–6 potential energy function. The charge distribution is modeled by a set of electric dipole moments located at the centers of the Lennard‐Jones spheres. The method for computing the Lennard‐Jones parameters, electric dipole moments (their magnitude and orientation) and positions of the interaction centers is described. Several models with different numbers of interaction centers were tested. The model with three‐center cytosine, four‐center guanine, four‐center thymine, and five‐center adenine satisfactorily reproduces the canonical Watson–Crick hydrogen bonding and stacking interaction energies of the all‐atom AMBER model. The computation time with the coarse‐grained model is reduced seven times compared with that of the all‐atom model. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Parameterization of the torsional potential for calix[4]arene‐substituted poly(thiophene)s
Authors: Preat Julien , Rodríguez‐Ropero Francisco , Torras Juan , Bertran Oscar , Zanuy David , Alemán Carlos
Published: December 2009

Three different strategies have been followed to develop the torsional force‐field parameters of the inter‐ring dihedral angles for calix[4]arene‐substituted poly(thiophene)s, a family of highly sensitive ion receptors. These procedures, which are based on the rotational profiles calculated using quantum mechanical methods, differ in the complexity of the model compounds and the processing applied to the quantum mechanical energies before the fitting. The performance of the three sets of developed parameters, which are essentially compatible with the General Amber Force Field, has been evaluated by computing the potential of mean forces for the inter‐ring rotation of 2,2′‐bithiophene, and its substituted analog bearing a calix[4]arene group in different environments. Finally, the ability of the new sets of torsional parameters to describe a calix[4]arene‐substituted poly(thiophene) in tetrahydrofuran solution has been checked using Molecular Dynamics simulations. Specifically, the molecular shape, the polymer conformation, and the effects of the Na+ions trapped in the cavity of the receptor have been examined. Although the potential derived from unsubstituted 2,2′‐bithiophene is able to reproduce the experimental free energies of the minima, the overall results indicate that the parameters derived from the analog bearing a calix[4]arene group provide the best description of the systems under study. This should be attributed to the strong constraints found in complex substituted poly(thiophene)s, which require parameterization strategies able to capture all the interactions and phenomena involved in their inter‐ring rotations. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Youth exposed to violence: the role of protective factors
Authors: Howard Kimberly A.S. , Budge Stephanie L. , McKay Kevin M.
Published: December 2009

Using a sample of 174 inner‐city urban high school students, this study examined the degree to which family and peer support would moderate the negative impact of exposure to violence on academic performance, symptoms of distress, and persistence intentions. Over 94% of the students reported having been exposed to at least one form of community violence at some point in their lives. Using hierarchical linear regression, the results indicated that family support provided a protective‐stabilizing moderating effect between exposure to violence and symptoms of distress. Peer support was found to have a protective‐stabilizing moderating effect between exposure to violence and persistence intentions. Although exposure to violence and persistence intentions were both related to grade point average, family and peer support were not found to moderate the impact of violence exposure and grades. © 2009 Wiley Periodicals, Inc.
Thrombospondin type I domain containing 7A (THSD7A) mediates endothelial cell migration and tube formation
Authors: Wang Chieh‐Huei , Su Pei‐Tsu , Du Xiao‐Yan , Kuo Meng‐Wei , Lin Chia‐Yi , Yang Chung‐Chi , Chan Hau‐Shien , Chang Shing‐Jyh , Kuo Calvin , Seo Kyunga , Leung Lawrence L. , Chuang Yung‐Jen
Published: December 2009

Angiogenesis is a highly organized process controlled by a series of molecular events. While much effort has been devoted to identifying angiogenic factors and their reciprocal receptors, far less information is available on the molecular mechanisms underlying directed endothelial cell migration. To search for novel proteins that participate in this process, we used the serial analysis of gene expression (SAGE) transcript profiling approach to identify genes that are selectively expressed in endothelial cells (ECs). Two EC SAGE libraries were constructed from human umbilical vein and artery ECs to enable data‐mining against other non‐ECs. A novel endothelial protein, Thrombospondin Type I Domain Containing 7A (THSD7A), with preferential expression in placenta vasculature and in human umbilical vein endothelial cells (HUVECs) was identified and targeted for further characterization. Overexpression of a THSD7A carboxyl‐terminal fragment in HUVECs inhibited cell migration and disrupted tube formation, while suppression of THSD7A expression enhanced HUVEC migration and tube formation. Immunohistological analysis revealed that THSD7A was expressed at the leading edge of migrating HUVECs, and it co‐localized with αVβ3 integrin and paxillin. This distribution was dispersed from focal adhesions after disruption of the actin cytoskeleton, suggesting the involvement of THSD7A in cytoskeletal organization. Our results show that THSD7A is a novel placenta endothelial protein that mediates EC migration and tube formation, and they highlight its potential as a new target for anti‐angiogenic therapy. J. Cell. Physiol. 222: 685–694, 2010. © 2009 Wiley‐Liss, Inc.