bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of loop and β-turn residues as structural and functional determinants for the lipoyl domain from the Escherichia coli 2-oxoglutarate dehydrogenase complex
Authors: Jones D. Dafydd , Perham Richard N. 
Published: January 2008

The lipoyl domain of the dihydrolipoyl succinyltransferase (E2o) component of the 2OGDH (2-oxoglutarate dehydrogenase) multienzyme complex houses the lipoic acid cofactor through covalent attachment to a specific lysine side chain residing at the tip of a β-turn. Residues within the lipoyl-lysine β-turn and a nearby prominent loop have been implicated as determinants of lipoyl domain structure and function. Protein engineering of the Escherichia coli E2o lipoyl domain (E2olip) revealed that removal of residues from the loop caused a major structural change in the protein, which rendered the domain incapable of reductive succinylation by 2-oxoglutarate decarboxylase (E1o) and reduced the lipoylation efficiency. Insertion of a new loop corresponding to that of the E. coli pyruvate dehydrogenase lipoyl domain (E2plip) restored lipoylation efficiency and the capacity to undergo reductive succinylation returned, albeit at a lower rate. Exchange of the E2olip loop sequence significantly improved the ability of the domain to be reductively acetylated by pyruvate decarboxylase (E1p), retaining approx. 10-fold more acetyl groups after 25 min than wild-type E2olip. Exchange of the β-turn residue on the N-terminal side of the E2o lipoyl-lysine DKA/V motif to the equivalent residue in E2plip (T42G), both singly and in conjunction with the loop exchange, reduced the ability of the domain to be reductively succinylated, but led to an increased capacity to be reductively acetylated by the non-cognate E1p. The T42G mutation also slightly enhanced the lipoylation rate of the domain. The surface loop is important to the structural integrity of the protein and together with Thr42 plays an important role in specifying the interaction of the lipoyl domain with its partner E1o in the E. coli 2OGDH complex.
High rates of superoxide production in skeletal-muscle mitochondria respiring on both complex I- and complex II-linked substrates
Authors: Muller Florian L. , Liu Yuhong , Abdul-Ghani Muhammad A. , Lustgarten Michael S. , Bhattacharya Arunabh , Jang Youngmok C. , Van Remmen Holly 
Published: January 2008

Despite the considerable interest in superoxide as a potential cause of pathology, the mechanisms of its deleterious production by mitochondria remain poorly understood. Previous studies in purified mitochondria have found that the highest rates of superoxide production are observed with succinate-driven reverse-electron transfer through complex I, although the physiological importance of this pathway is disputed because it necessitates high concentrations of succinate and is thought not to occur when NAD is in the reduced state. However, very few studies have examined the rates of superoxide production with mitochondria respiring on both NADH-linked (e.g. glutamate) and complex II-linked substrates. In the present study, we find that the rates of superoxide production (measured indirectly as H2O2) with glutamate+succinate (∼1100 pmol of H2O2·min−1·mg−1) were unexpectedly much higher than with succinate (∼400 pmol of H2O2·min−1·mg−1) or glutamate (∼80 pmol of H2O2·min−1·mg−1) alone. Superoxide production with glutamate+succinate remained high even at low substrate concentrations (&lt;1 mM), was decreased by rotenone and was completely eliminated by FCCP (carbonyl cyanide p-trifluoromethoxyphenylhydrazone), indicating that it must in large part originate from reverse-electron transfer through complex I. Similar results were obtained when glutamate was replaced with pyruvate, α-ketoglutarate or palmitoyl carnitine. In contrast, superoxide production was consistently lowered by the addition of malate (malate+succinate ∼30 pmol of H2O2·min−1·mg−1). We propose that the inhibitory action of malate on superoxide production can be explained by oxaloacetate inhibition of complex II. In summary, the present results indicate that reverse-electron transfer-mediated superoxide production can occur under physiologically realistic substrate conditions and suggest that oxaloacetate inhibition of complex II may be an adaptive mechanism to minimize this.
‘Communication is everything I think.’ Parenting a child who needs Augmentative and Alternative Communication (AAC)
Authors: Marshall Julie , Goldbart Juliet 
Published: January 2008

Background: Anecdotal and research evidence suggests that professionals may not fully understand the perspectives of families of children who need or use Augmentative and Alternative Communication (AAC). This may impact on the provision of appropriate services.Aims: The aim was to explore the lived experience of parents of children in Britain who used AAC, with particular emphasis on the ways in which children's need for and use of AAC impacts on family life and communication.Methods & Procedures: The parents/carers of 11 children aged 3–10 years, who lived in Britain and who were in the early stages of using AAC, were recruited to take part in the study. Individual semi‐structured interviews were carried out in order to access rich descriptions of parents' experiences and views about having children who need to use AAC. The interviews were recorded, transcribed verbatim and analysed thematically to generate thematic networks.Outcomes & Results: Analysis revealed three thematic networks. The three Global Themes represented by the networks were concerned with the following areas: the child's communication and interaction; wider societal issues; and parents' views and experiences. Each Global Theme contained lower order Organizational Themes and these in turn were comprised of Basic Themes. Parents shared many common concerns, but the data also revealed some diversity of views. The themes and sub‐themes are described with illustrative and representative quotes.Conclusions: These parents are experts on their children and may also be experts on AAC. Many factors impact on parents and the level and type of involvement they have with their children and their upbringing. Speech and language therapists need to acknowledge parents' knowledge and expertise regarding their children. They need to recognize that there are parent, child, family and external factors which impact on parents' ability and willingness to be involved in speech and language therapist provision, and that these factors are not static over time. The use of ethnographic interviewing techniques should be considered a valuable aspect of speech and language therapist intervention.
Publisher's Announcement
Authors: McGlashan Yasmin 
Published: January 2008

Article numbering

Nuclear Fusion has moved from sequential page numbering to an article numbering system, offering important advantages and flexibility by speeding up the publication process. Papers in different issues or sections can be published online as soon as they are ready, without having to wait for a whole issue or section to be allocated page numbers.
The bibliographic citation will change slightly. Articles should be referenced using the six-digit article number in place of a page number, and this number must include any leading zeros. For instance, from this issue:
Li G.Q. et al 2008 Nucl. Fusion
48 015001
Articles will continue to be published on the web in advance of the print edition.
The interaction between plasma rotation, stochastic fields and tearing mode excitation by external perturbation fields
Authors: De Bock M.F.M. , Classen I.G.J. , Busch C. , Jaspers R.J.E. , Koslowski H.R. , Unterberg B. 
Published: January 2008

For fusion reactors, based on the principle of magnetic confinement, it is important to avoid so-called magnetic islands or tearing modes. They reduce confinement and can be the cause of major disruptions. One class of magnetic islands is that of the perturbation field driven modes. This perturbation field can, for example, be the intrinsic error field. Theoretical work predicts a strong relationship between plasma rotation and the excitation of perturbation field modes.Experimentally, the theory on mode excitation and plasma rotation has been confirmed on several tokamaks. In those experiments, however, the control over the plasma rotation velocity and direction, and over the externally applied perturbation field was limited. In this paper experiments are presented that were carried out at the TEXTOR tokamak. Two tangential neutral beam injectors and a set of helical perturbation coils, called the dynamic ergodic divertor (DED), provide control over both the plasma rotation and the external perturbation field in TEXTOR. This made it possible to set up a series of experiments to test the theory on mode excitation and plasma rotation in detail.The perturbation field induced by the DED not only excites magnetic islands, it also sets up a layer near the plasma boundary where the magnetic field is stochastic. It will be shown that this stochastic field alters both the rotational response of the plasma on the perturbation field and the threshold for mode excitation. It therefore has to be included in an extended theory on mode excitation.
Characterization of a Conserved Rhoptry-Associated Leucine Zipper-Like Protein in the Malaria Parasite
Plasmodium falciparum
Authors: Haase Silvia , Cabrera Ana , Langer Christine , Treeck Moritz , Struck Nicole , Herrmann Susann , Jansen Pascal W. , Bruchhaus Iris , Bachmann Anna , Dias Suzana , Cowman Alan F. , Stunnenberg Hendrik G. , Spielmann Tobias , Gilberger Tim-Wolf 
Published: January 2008

ABSTRACT

One of the key processes in the pathobiology of the malaria parasite is the invasion and subsequent modification of the human erythrocyte. In this complex process, an unknown number of parasite proteins are involved, some of which are leading vaccine candidates. The majority of the proteins that play pivotal roles in invasion are either stored in the apical secretory organelles or located on the surface of the merozoite, the invasive stage of the parasite. Using transcriptional and structural features of these known proteins, we performed a genomewide search that identified 49 hypothetical proteins with a high probability of being located on the surface of the merozoite or in the secretory organelles. Of these candidates, we characterized a novel leucine zipper-like protein in
Plasmodium falciparum
that is conserved in
Plasmodium
spp. This protein is expressed in late blood stages and localizes to the rhoptries of the parasite. We demonstrate that this
Plasmodium
sp.-specific protein has a high degree of conservation within field isolates and that it is refractory to gene knockout attempts and thus might play an important role in invasion.
Reactive Nitrogen Species Contribute to Innate Host Defense againstCampylobacter jejuni
Authors: Iovine Nicole M. , Pursnani Seema , Voldman Alex , Wasserman Gregory , Blaser Martin J. , Weinrauch Yvette 
Published: January 2008

ABSTRACTCampylobacter jejuni, a gram-negative, invasive organism, is a common cause of food-borne bacterial diarrheal disease. However, the relationship betweenC. jejuniand the innate immune system is not well described. To better characterize host defense againstC. jejuni, we investigated the ability of nitric oxide/reactive nitrogen species to kill two strains ofC. jejuni. C. jejuniviability was measured after exposure to reactive nitrogen species produced biochemically as acidified nitrite and by bone marrow-derived macrophages. We report that acidified nitrite caused a 3-log-increased kill ofC. jejuni(P< 0.05) at doses that did not affect the viability ofSalmonella entericaserovar Typhimurium. Expression ofNOS2, the gene responsible for the production of inducible nitric oxide, was increased >100-fold in murine macrophages after incubation withC. jejuni(P< 0.001). These macrophages effected a 2-log-increased kill ofC. jejuniover 24 h compared to that by NOS2−/−macrophages unable to produce nitric oxide (P< 0.05). These findings suggest that the mammalian host upregulates the production of nitric oxide in response to exposure toC. jejuniand that nitric oxide and reactive nitrogen species comprise part of the innate defense mechanisms that contribute to the resolution ofC. jejuniinfection.
Genotyping of
Chlamydia trachomatis
by Microsphere Suspension Array
Authors: Huang Chung-Ter , Wong Wing-Wai , Li Lan-Hui , Chiang Chien-Chou , Chen Bor-Dong , Li Shu-Ying 
Published: January 2008

ABSTRACT

The identification of
Chlamydia trachomatis
genotypes is important for both the study of molecular epidemiology and infection control. We have developed a microsphere suspension array assay that can identify
C. trachomatis
genotypes rapidly and accurately and also discriminate among multiple genotypes in one clinical specimen.
Protein Modification by O-Linked GlcNAc Reduces Angiogenesis by Inhibiting Akt Activity in Endothelial Cells
Authors: Luo Bai , Soesanto Yudi , McClain Donald A. 
Published: January 2008

Objective—Glucose flux through the hexosamine biosynthesis pathway (HBP) has been implicated in the development of diabetic vascular complications. O-linked N-acetylglucosamine (O-GlcNAc) modification on protein is the major mechanism mediating the actions of the HBP. Impaired angiogenesis is well-recognized in diabetes; however, the mechanisms are not completely defined. Here, we investigated the role of protein O-GlcNAc modification in angiogenesis.Methods and Results—In a mouse aortic ring assay, elevated O-GlcNAc levels induced by high-fat diet, streptozotocin-induced diabetes, or in vitro glucosamine treatment were associated with impaired angiogenesis. In cultured human umbilical vein endothelial cells and EA.hy926 endothelial cells, glucosamine increased protein O-GlcNAc modification and inhibited cell migration and capillary-like structure formation. Conversely, removal of O-GlcNAc by adenoviral-mediated overexpression of O-GlcNAcase improved these steps of angiogenesis. Also, high concentrations of glucose reduced capillary-like structure formation of human umbilical vein endothelial cells. Akt was recognized by an O-GlcNAc specific lectin, and glucosamine increased the amounts of Akt protein in these lectin precipitates. Increased glycosylation paralleled reduced Akt activity in endothelial cells.Conclusion—These results suggest that elevated protein O-GlcNAc modification through the HBP impairs angiogenesis in endothelial cells, possibly by inhibiting Akt signaling.
An Ivory Plaque from Mele Hairam, Turkmenistan
Authors: Kornacka Maja 
Published: December 2007

AbstractThe exploration works at the Partho-Sassanian fire temple at Mele Hairam, southern Turkmenistan, have yielded a fragmentarily preserved double-faced ivory plaque in relief. Although the secular character of scenes depicted excludes the possibility of the plaque playing any role in the fire cult, it might have served as a valuable donation to the temple. The alien nature of the scenes indicates a foreign provenience of the plaque and may be linked to the ivory and bone items belonging to the so-called Begram Treasure or Hoard, and, more specifically, to local Bactrian workshops. Neither the exact dating of the plaque nor the date of its depositing at the temple can be precisely established. The piece could, however, have easily arrived to the temple due to the latter's unique location in the immediate vicinity of the Silk Road.
Stress above Wind-Plus-Paddle Waves: Modeling of a Laboratory Experiment
Authors: Makin V. K. , Branger H. , Peirson W. L. , Giovanangeli J. P. 
Published: January 2008

Abstract
A model based on wind-over-waves coupling (WOWC) theory is used to simulate a laboratory experiment and to explain the observed peculiarities of the surface stress distribution above a combined wave field: wind-generated-plus-monochromatic-paddle waves. Observations show the systematic and significant decrease in the stress as the paddle wave is introduced into the pure wind-wave field. As the paddle-wave steepness is further increased, the stress level returns to the stress level characteristic of the pure wind waves. Further increase in the paddle-wave steepness augments the stress further. The WOWC model explains this peculiarity of the stress distribution by the fact that the paddle waves significantly damp the wind waves in the spectral peak. The stress supported by these dominant waves rapidly falls when the paddle wave is introduced, and this decrease is not compensated by the stress induced by the paddle wave. With further increase in the steepness of the paddle wave, the stress supported by dominant wind waves stays at a low level while the stress supported by the paddle waves continues to grow proportional to the square of the steepness, finally exceeding the stress level characteristic of the pure wind-wave field.
Buoyant Eddies Entering the Labrador Sea Observed with Gliders and Altimetry
Authors: Hátún Hjálmar , Eriksen Charles C. , Rhines Peter B. 
Published: January 2008

Abstract
Intense, buoyant anticyclonic eddies spawned from the west Greenland boundary current were observed with high-resolution autonomous Seaglider hydrography and satellite altimetry as they entered the Labrador Sea interior. Surveys of their internal structure establish the transport of both low-salinity water in the upper ocean and warm, saline Irminger water at depth. The observed eddies can contribute significantly to the rapid restratification of the Labrador Sea interior following wintertime deep convection. These eddies have saline cores between 200 and 1000 m, low-salinity cores above 200 m, and a velocity field that penetrates to at least 1000 m, with 0–1000-m average speeds exceeding 40 cm s−1. Their trajectory, together with earlier estimates of the gyre circulation, suggests why the observed region of deep convection is so small and does not occur where wintertime cooling by the atmosphere is most intense. The cyclostrophic surface velocity field of the anticylones from satellite altimetry matched well with in situ dynamic height baroclinic velocity calculations.
Interannual Sea Level Variations in the South Pacific from 5° to 28°S
Authors: Li Jianke , Clarke Allan J. 
Published: January 2008

Abstract
Ocean Topography Experiment (TOPEX)/Poseidon/Jason-1 satellite altimeter observations for the 11-yr period from January 1993 to December 2003 show that in the South Pacific Ocean most of the interannual sea level variability in the region 5°–28°S is west of 160°W. This interannual variability is largest from about 5° to 15°S and from 155°E to 160°W, reaching a root-mean-square value of over 11 cm. Calculations show that this interannual sea level signal can be described by first and second baroclinic vertical mode Rossby waves forced by the curl of the interannual Ekman transport. This curl, which tends to be positive during El Niño and negative during La Niña, generates positive (negative) sea level anomalies during El Niño (La Niña) that increase westward in amplitude in accordance with Rossby wave dynamics. The sea level anomalies are not exactly in phase with the curl forcing because Sverdrup balance does not hold—vortex stretching also contributes to the response. East of 160°W is a large “quiet” region of low interannual sea level variability, especially south of about 15°S. This is surprising because there is no flow into the coast, so the interannual sea level amplitude of equatorial origin should be constant along the coast, resulting in a source of westward-propagating Rossby waves of considerable amplitude. The large low-variability region results because coastal sea level amplitude falls between 5° and 15°S, so the Rossby wave source south of 15°S is weak. During El Niño the sea level is higher than normal at the coast, so the southward fall in anomalous sea level implies, by geostrophy, that there is an anomalous onshore flow. This flow feeds an anomalous southward El Niño current of up to 20 cm s−1 above the 30–50-km-wide shelf edge. During La Niña the sea level is lower than normal at the coast and the flows reverse: a narrow anomalously northward shelf-edge flow feeding a broad offshore flow between 5° and 15°S. South of 16°S the coastal flow is much weaker.
Prevalence and Correlates of Suicidal Behaviour Among Adolescents in Southwest Nigeria
Authors: Omigbodun Olayinka , Dogra Nisha , Esan Oluyomi , Adedokun Babatunde 
Published: January 2008

Background: Despite being recognized by the World Health Organization as a significant social and health concern, information on suicidal behaviours in Nigerian adolescents is unknown. Aims: To establish the prevalence and associated psychosocial correlates of suicidal ideation and attempts in Nigerian youth. Methods: Stratified sampling was used to identify youth aged 10—17 years who completed the Nigeria version of the Global School Health Questionnaire (GSHQ) and the Diagnostic Predictive Scale (DPS) for youths (suicidal behaviour questions) in a classroom setting. Results: A total of 1429 youth completed the instruments. Over 20% reported suicidal ideation and approximately 12% reported that they had attempted suicide in the last year. Adolescents living in urban areas, from polygamous or disrupted families, had higher rates of suicidal behaviour. Multiple psychosocial factors such as sexual abuse, physical attack and involvement in physical fights were significant predictors of suicidal behaviour. Conclusion: Factors associated with suicidal ideation and behaviours are similar to those found in other studies but the rates of both suicidal ideation and attempts are towards the upper limit of rates for youth. This study suggests that there is an urgent need for Nigerian policymakers and health providers to review and address this issue.
The Relationship Between Past Traumatic Experience and Sickness Absence
Authors: Izutsu Takashi , Shibuya Mihoko , Tsutsumi Atsuro , Konishi Takako , Kawamura Noriyuki 
Published: January 2008

Background: Past traumatic experiences have been reported to lower stress tolerance, thereby increasing job strain. However, the relationship between past traumatic experiences and employee sickness absence is poorly understood. Aims: This study explores the relationship between sickness absence and past traumatic experience with regard to the amount of time lapsed after the experience, job strain and other mental health states such as depression and anxiety. Methods: A total of 3238 workers were assessed for levels of traumatic stress, depressive status, anxiety and job stress. Results: Odds ratios of the presence of traumatic experiences to sickness absence, adjusted for sex, age and depressive and anxiety states, were presented according to the length of time that had passed since the traumatic events. The odds ratio in the 0—1 Years Group was 1.75 ( p < 0.05), and the odds ratio for the 19+ Years Group was 1.46 ( p < 0.1). Conclusions: Past traumatic events are related to sickness absence. Sickness absence resulting from a past traumatic experience is important with respect to industrial health.