bluuebunny/crossref_metadata_2025_split huggingface dataset:
Current Opinions on the Functions of Tocopherol Based on the Genetic Manipulation of Tocopherol Biosynthesis in Plants
Authors: Li Yin , Wang Zinan , Sun Xiaofen , Tang Kexuan 
Published: September 2008

Abstract As a member of an important group of lipid soluble antioxidants, tocopherols play a paramount role in the daily diet of humans and animals. Recently, genes required for tocochromanol biosynthesis pathway have been identified and cloned with the help of genomics‐based approaches and molecular manipulation in the model organisms: Arabidopsis thaliana and Synechocystis sp. PCC 6803. At the basis of these foundations, genetic manipulation of tocochromanol biosynthesis pathway can give rise to strategies that enhance the level of tocochromanol content or convert the constitution of tocochromanol. In addition, genetic manipulations of the tocochromanol biosynthesis pathway provide help for the study of the function of tocopherol in plant systems. The present article summarizes recent advances and pays special attention to the functions of tocopherol in plants. The roles of tocopherol in the network of reactive oxygen species, antioxidants and phytohormones to maintain redox homeostasis and the functions of tocopherol as a signal molecule in chloroplast‐to‐nucleus signaling to regulate carbohydrate metabolism are also discussed.
Spatial Patterns and Interspecific Associations of Three Canopy Species at Different Life Stages in a Subtropical Forest, China
Authors: Li Lin , Wei Shi‐Guang , Huang Zhong‐Liang , Ye Wan‐Hui , Cao Hong‐Lin 
Published: September 2008

AbstractSpatial patterns of species at different life stages are an important aspect for understanding causal mechanisms that facilitate species co‐existence. Using Ripley's univariateL(t) and bivariateL12(t) functions, we analyzed the spatial patterns and interspecific associations of three canopy species at different life history stages in a 20‐ha subtropical forest plot in Dinghushan Nature Reserve. Based on diameter at breast height (DBH), four life stages were distinguished.Castanopsis chinensisandSchima superbashowed a unimodal DBH distribution.Engelhardtia roxburghianashowed a bimodal curve.L(t) function analysis showed significantly aggregated distributions of all three species at later life stages and random distribution at early life stages at some scales. From the analysis ofL12(t) function, the results showed the positive association was a dominant pattern for most species pairs at most scales but the intensity of association decreases with the increase of life stages. Juveniles of the three species had no negative intra‐ and interspecific associations with the older life stages. Only premature trees were suppressed by overmature trees at some scales. Considering these results, we found three canopy‐dominant species that lacked regeneration. There was no direct competition occurring between understorey individuals. Young trees can grow well under conspecific species with two other species. Longevity and lack of regeneration led to a large number of trees stored in mature and overmature stages, therefore, intra‐ and inter‐competition can be strong at later life stages.
QTL and QTL × Environment Effects on Agronomic and Nitrogen Acquisition Traits in Rice
Authors: Senthilvel Senapathy , Vinod Kunnummal Kurungara , Malarvizhi Palaniappan , Maheswaran Marappa 
Published: September 2008

Abstract Agricultural environments deteriorate due to excess nitrogen application. Breeding for low nitrogen responsive genotypes can reduce soil nitrogen input. Rice genotypes respond variably to soil available nitrogen. The present study attempted quantification of genotype × nitrogen level interaction and mapping of quantitative trait loci (QTLs) associated with nitrogen use efficiency (NUE) and other associated agronomic traits. Twelve parameters were observed across a set of 82 double haploid (DH) lines derived from IR64/Azucena. Three nitrogen regimes namely, native (0 kg/ha; no nitrogen applied), optimum (100 kg/ha) and high (200 kg/ha) replicated thrice were the environments. The parents and DH lines were significantly varying for all traits under different nitrogen regimes. All traits except plant height recorded significant genotype × environment interaction. Individual plant yield was positively correlated with nitrogen use efficiency and nitrogen uptake. Sixteen QTLs were detected by composite interval mapping. Eleven QTLs showed significant QTL × environment interactions. On chromosome 3, seven QTLs were detected associated with nitrogen use, plant yield and associated traits. A QTL region between markers RZ678, RZ574 and RZ284 was associated with nitrogen use and yield. This chromosomal region was enriched with expressed gene sequences of known key nitrogen assimilation genes.
Global Identification of Significantly Expressed Genes in Developing Endosperm of Rice by Expression Sequence Tags and cDNA Array Approaches
Authors: Tu Qichao , Dong Haitao , Yao Haigen , Fang Yongqi , Dai Cheng'en , Luo Hongmei , Yao Jian , Zhao Dong , Li Debao 
Published: September 2008

Abstract Rice endosperm plays a very important role in seedling germination and determines the qualities of rice grain. Although studies on specific gene categories in endosperm have been carried out, global view of gene expression at a transcription level in rice endosperm is still limited. To gain a better understanding of the global and tissue‐specific gene expression profiles in rice endosperm, a cDNA library from rice endosperm of immature seeds was sequenced. A cDNA array was constructed based on the tentative unique transcripts derived from expression sequence tag (EST) assembling results and then hybridized with cDNAs from five different tissues or organs including endosperm, embryo, leaf, stem and root of rice. Significant redundancy was found for genes encoding prolamin, glutelin, allergen, and starch synthesis proteins, accounting for ∼34% of the total ESTs obtained. The cDNA array revealed 87 significantly expressed genes in endosperm compared with the other four organs or tissues. These genes included 13 prolamin family proteins, 17 glutelin family proteins, 12 binding proteins, nine catalytic proteins and four ribosomal proteins, indicating a complicated biological processing in rice endosperm. In addition, Northern verification of 1,4‐alpha‐glucan branching enzyme detected two isoforms in rice endosperm, the larger one of which only existed in endosperm.
Genome‐wide Characterization of Long Terminal Repeat ‐retrotransposons in Apple Reveals the Differences in Heterogeneity and Copy Number between Ty1‐copiaand Ty3‐gypsyRetrotransposons
Authors: Sun Hai‐Yue , Dai Hong‐Yan , Zhao Gui‐Ling , Ma Yue , Ou Chun‐Qing , Li He , Li Lin‐Guang , Zhang Zhi‐Hong 
Published: September 2008

AbstractThe conserved domains of reverse transcriptase (RT) genes of Ty1‐copiaand Ty3‐gypsygroups of long terminal repeat (LTR) retrotransposons were isolated from theMalus domesticagenome using degenerate oligonucleotide primers. Sequence analysis showed that 45% of Ty1‐copiaand 63% of Ty3‐gypsyRT sequences contained premature stop codons and/or indels disrupting the reading frame. High heterogeneity among RT sequences of both Ty1‐copiaand Ty3‐gypsygroup retrotransposons was observed, but Ty3‐gypsygroup retrotransposons in the apple genome are less heterogeneous than Ty1‐copiaelements. Retrotransposon copy number was estimated by dot blot hybridizations for Ty1‐copia(∼5 000) and Ty3‐gypsy(∼26 000). All elements of the two types of LTR retrotransposons comprise approximately 38% of theM. domesticagenome, with the Ty3‐gypsygroup contribution being higher (33.5%) than the Ty1‐copiaone (4.6%). Transcription was not detected by reverse transcription‐polymerase chain reaction for either Ty1‐copiaor Ty3‐gypsyretrotransposons in the leaves of plantsin vitroor in leaf explants cultured on medium supplemented with high concentration benzylaminopurine. This research reveals the differences in heterogeneity and copy number between Ty1‐copiaand Ty3‐gypsyretrotransposons in the apple genome. Ty1‐copiaretrotransposon has higher heterogeneity than Ty3‐gypsyretrotransposon, but the latter has a higher copy number, which implies that Ty3‐gypsyretrotransposons may play a more important role in the apple genome evolution.
Pretreatment with insulin before ischaemia reduces infarct size in Langendorff‐perfused rat hearts
Authors: Fuglesteg B. N. , Tiron C. , Jonassen A. K. , Mjøs O. D. , Ytrehus K. 
Published: September 2008

AbstractAim:  To compare the possible role of Akt and mammalian target of rapamycin (mTOR) in mediating cardioprotection against ischaemia under three different conditions: (1) During ischaemic preconditioning (IPC), (2) when insulin was given as a pretreatment agent (InsPC) and (3) when insulin was given as a reperfusion cell survival agent (InsR).Methods:  Isolated perfused rat hearts were subjected to IPC (3 × 5 min) or InsPC (50 mU mL−1; 3 × 5 min), before 30 min of regional ischaemia followed by 120 min of reperfusion ± 1L‐6‐hydroxymethyl‐chiro‐inositol‐2‐[(R)‐2‐O‐methyl‐3‐O‐octadecylcarbonate] (HIMO) (20 μm; Akt inhibitor) or rapamycin (1 nm; mTOR inhibitor). In addition, insulin (3 mU mL−1) was given at the onset of reperfusion, ±HIMO or rapamycin. Risk zone (R) and infarct size (I) were determined with Evans blue and tetrazolium staining respectively. Western blot analysis was performed on tissue from Langendorff‐perfused rat hearts and cell lysates from cultured HL1 cells.Results:  IPC, InsPC and InsR treatment resulted in a significant reduction in infarct size compared to controls (all P < 0.05). This protective effect of IPC and insulin was abolished by the inhibitors. However, the putative Akt inhibitor, although capable of abolishing cardioprotection induced by insulin, was not able to inhibit insulin‐induced phosphorylation of Akt in Langendorff‐perfused rat hearts and cultured HL1 cells. The target for this compound therefore remains to be determined.Conclusion:  IPC and insulin (either as InsPC or InsR) appear to activate mTOR, and this kinase seems to play an essential role in cardioprotection against ischaemia and reperfusion injury as rapamycin blocked the protection.
The role of the α‐adrenergic receptor in the leg vasoconstrictor response to orthostatic stress
Authors: Kooijman M. , Rongen G. A. , Smits P. , Van Kuppevelt H. J. M. , Hopman M. T. E. 
Published: September 2008

AbstractAim: The prompt increase in peripheral vascular resistance, mediated by sympathetic α‐adrenergic stimulation, is believed to be the key event in blood pressure control during postural stress. However, despite the absence of central sympathetic control of the leg vasculature, postural leg vasoconstriction is preserved in spinal cord‐injured individuals (SCI). This study aimed at assessing the contribution of bothcentralandlocalsympathetically induced α‐adrenergic leg vasoconstriction to head‐up tilt (HUT) by including healthy individuals and SCI, who lackcentralsympathetic baroreflex control over the leg vascular bed.Methods: In 10 controls and nine SCI the femoral artery was cannulated for drug infusion. Upper leg blood flow (LBF) was measured bilaterally using venous occlusion strain gauge plethysmography before and during 30° HUT throughout intra‐arterial infusion of saline or the non‐selective α‐adrenergic receptor antagonist phentolamine respectively. Additionally, in six controls the leg vascular response to the cold pressor test was assessed during continued infusion of phentolamine, in order to confirm complete α‐adrenergic blockade by phentolamine.Results: During infusion of phentolamine HUT still caused vasoconstriction in both groups: leg vascular resistance (mean arterial pressure/LBF) increased by 10 ± 2 AU (compared with 12 ± 2 AU during saline infusion), and 13 ± 3 AU (compared with 7 ± 3 AU during saline infusion) in controls and SCI respectively.Conclusion: Effective α‐adrenergic blockade did not reduce HUT‐induced vasoconstriction, regardless of intact baroreflex control of the leg vasculature. Apparently, redundant mechanisms compensate for the absence of sympathetic α‐adrenoceptor leg vasoconstriction in response to postural stress.
The Talk of Tamils in Multilingual Montreal: A Study of Intersecting Language Ideologies in Nationalist Quebec
Authors: Das Sonia 
Published: September 2008

AbstractIn Montreal, racial, caste, socioeconomic, and gender inequalities are often masked as neutral‐seeming linguistic differences of dialect, register, and accent. These sociolinguistic hierarchies are upheld by intersecting language ideologies, or essentialised beliefs about language use and ethnic identity. Quebec nationalist and multicultural policies endorse language ideologies of linguistic purity and sociolinguistic compartmentalisation to depict a cohesive nation while maintaining its racial and ethnic distinctions. Similarly, Montreal Tamil diaspora leaders encourage different Tamil‐speaking groups to participate in sociolinguistically segregated domains to preserve purist linguistic standards and maintain socioeconomic, caste, and gender distinctions. Heritage language programmes reproduce these language‐based distinctions for differentiating between types of Québécois citizens, while Montreal Tamil youth selectively challenge or endorse such prescriptions to produce a range of social identities and linguistic practices that correspond to their experiences as ethnic and racial minorities.
Religion, Ethnicity and Immigrant Integration: ‘Latino’ Lutherans versus ‘Mexican’ Catholics in a Midwestern City
Authors: Freier Luisa Feline 
Published: September 2008

AbstractAlthough the majority of Latin American immigrants to the United States are Roman Catholics, increasing numbers of Latinos are converting to Protestantism. To understand the incentives for, and any possible integration effects of, immigrants' religious conversion, it is crucial to examine not only the religious but also the social boundaries of new immigrant congregations. This article examines the class‐based but ethnically labeled boundary construction of a Latino Lutheran towards a Latino Roman Catholic congregation in Madison, Wisconsin. The de facto ethnicised class differentiation via denominational choice shows that first: for ethnic discrimination to occur, no exclusive and imperative categories are needed, second: socioeconomic identification can superimpose religious and ethno‐cultural feelings of belonging, and third: the formation of a more liberal and higher educated ‘Latino’ Lutheran community facilitates the civic integration of its worshippers into the broader community based on the political mobilisation of panethnic identification.
The Shifting Landscapes of ‘Nationalism’
Authors: Smith Anthony D. 
Published: September 2008

AbstractThe field of study that comprises nations and nationalism is often seen as riven by a conflict between ‘modernists’ and their opponents. In fact, the field is far more fragmented than such a characterisation suggests. From the very first normative critical essays 150 years ago, it has been composed of shifting landscapes in which different approaches and perspectives overlap and cross‐cut each other like intersecting monologues. While there was a short period of engagement in the 1980s, a ‘classic debate’ between modernists, perennialists and ethno‐symbolists who embraced a macro‐analytic framework and a causal‐historical methodology, the familiar landscape has radically shifted to reveal a series of deconstructionist strategies and techniques; and while rational choice theories, among others, continue to embrace causal‐historical analysis, there has been a rejection in many quarters of both macro‐analytic narratives and causal‐historical analysis. The new anti‐essentialist strategies include feminist critiques, the study of everyday nationhood, the hybridisation of national identities, and debates about the ‘ethics of nationalism’ which echo earlier critiques. Above all, there is a new concern with the application of globalising trends to nations and nationalism, and especially with the role of nations without states, and the impact of supranationalism, large‐scale migration and ‘religious nationalisms’.
The Role of Ukrainian Museums in the United States Diaspora in Nationalising Ukrainian Identity
Authors: Kochman Adrienne 
Published: September 2008

AbstractUkrainian museums in the United States diaspora have attempted to construct a culturally authentic history outside Ukraine itself where, for the better part of the twentieth century, Ukrainian artistic endeavors were defined within a russified Soviet framework. Established largely by third wave post‐World War II Ukrainian immigrants interested in seeing an independent Ukraine, these museums have been a symbolic testament to democratic self‐definition. A separate Ukraine pavilion at the Century of Progress Exposition in Chicago of 1933 set an earlier precedent in its representation of Ukraine as an autonomous nation. This affirmed later permanent museums which collected indigenous Ukrainian folk art and artifacts as well as modern art – created by native Ukrainians and those of the diaspora – in opposition to the official Soviet Socialist Realist canon. Ukrainian independence in 1991 and increased national awareness after 2004 elections realigned these museums' mission from a cultural refuge to active participants in the new nation‐building process.
Assessment of hepatic steatosis and hepatic tissue blood flow by xenon computed tomography in nonalcoholic steatohepatitis
Authors: Kobayashi Minoru , Suzuki Michihiro , Ikeda Hiroki , Takahashi Hideaki , Matsumoto Nobuyuki , Maeyama Shiro , Sase Shigeru , Iino Shiro , Itoh Fumio 
Published: September 2008

Aim: The diagnosis of non‐alcoholic steatohepatitis (NASH) can be difficult using blood tests and imaging studies. Histological diagnosis by liver biopsy remains the gold standard of NASH diagnosis. There is an urgent need to develop and validate simple, reproducible, noninvasive tests to accurately assess NASH stage and grade. We assess the usefulness of xenon computed tomography (Xe‐CT), as a non‐invasive method of quantitatively and visually determining hepatic tissue blood flows (TBFs), and xenon solubility (λ value) simultaneously with TBF, in the evaluation of NASH pathophysiology.Methods: Histological severity of fatty changes and severity of fibrosis based on Brunt's classification were determined in 38 NASH patients. We evaluated correlations between the grade of fatty changes and λ value, and correlations between the stage of fibrosis and TBFs.Results: The λ value showed significant positive correlations with both grade of steatosis (r = 0.813,P < 0.001) and each 10% range of histological fatty infiltration (r = 0.926,P < 0.001). A significant negative correlation was seen between λ value and the liver : spleen ratio (r = −0.835,P < 0.001). Portal venous tissue blood flow and total hepatic tissue blood flow showed significant negative correlations with the progression of fibrosis (r = −0.465,P < 0.01;r = −0.433,P < 0.01, respectively). Total hepatic tissue blood flow tended to decrease with progressing grade of steatosis.Conclusion: Xe‐CT offers a convenient and objective method for evaluating fatty infiltration and changes in blood flow in the entire liver, and appears useful for detailed evaluation of patients with NASH.
The Stabilization Energy of the GLU-LYS Salt Bridge in the Protein/Water Environment: Correlated Quantum Chemical ab initio, DFT and Empirical Potential Studies
Authors: Řezáč Jan , Berka Karel , Horinek Dominik , Hobza Pavel , Vondrášek Jiří 
Published: September 2008

The stabilization energies of Glu-Lys salt bridges are calculated at the CCSD(T) complete basis set limit to provide a reasonable description of the strength of the ion-pair bond in the gas phase. The effect of the environment (protein with ε = 4 and water with ε = 80) on the stabilization energy was introduced via a modification of the quantum chemical DFT energy, for which the COSMO methodology was adopted. The other (standard) approach was based on incorporating a dielectric constant into the Coulomb electrostatic term of the Amber empirical potential function and utilizing the generalized Born model implemented in the Amber program. The environment affects the stabilization energy of the salt bridge dramatically: The protein reduces the energy to less than one half of the original value, whereas water sometimes changes stabilization to destabilization. Both theoretical procedures, based on completely different theoretical backgrounds, yield very similar results, which strongly support their validity. An ion pair is converted to an ion-neutral pair when its pH is changed. This transformation is connected with a strong reduction of the stabilization energy regardless of the environment. The substantial differences in the stabilization energies of ion pairs and ion-neutral pairs contradict the negligible changes of free energy detected experimentally. Evidently, the contribution of formation and hydration entropy is significant and compensates for the large stabilization energies.
The origins ofErigeron trifidus(Asteraceae), an agamospermous rare species in AlbertaThis paper is one of a selection of papers published in the Special Issue on Systematics Research.
Authors: Burke J. L. , Bain J. F. 
Published: September 2008

Erigeron trifidus Hook. (Asteraceae) is a rare species in Alberta thought to have originated via hybridization between Erigeron compositus Pursh and Erigeron lanatus Hook., and is disjunct in three alpine regions of Alberta. An analysis of uni- and bi-parentally inherited molecular markers from E. trifidus and its putative parents yielded data that support the hybridization hypothesis for some of the populations. In most cases, cpDNA haplotypes in E. trifidus were the same as in E. lanatus, suggesting that E. lanatus is the maternal parent. Sequencing and cloning the nuclear ETS region revealed multiple repeat types in most individuals. Erigeron trifidus contained only the repeat types also present in the putative parents. In addition, E. trifidus displayed the highest percentage of intra-individual repeat type polymorphism, consistent with a hybrid origin. All northern populations of E. trifidus exhibited a particular pattern of repeat type variation that was absent in central and southern populations. Since E. lanatus is absent from Ram Mountain (in central Alberta), it is likely that populations from this locality, previously identified as E. trifidus, are instead a different agamospermous variant of E. compositus. In southern Alberta (Waterton Lakes), populations of E. trifidus are thought to be the product of local hybridization, and are therefore of different origin from the northern populations. The identity of the putative parents in the southern region remains uncertain.