bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of the mouse retinal taurine transporter (TAUT) by protein kinases inXenopusoocytes
Authors: Loo Donald D.F. , Hirsch Jochen R. , Sarkar Hemanta K. , Wright Ernest M.
Published: April 2003

The goal was to investigate the role of protein kinases in modulating taurine transporter activity inXenopus laevisoocytes expressing the mouse retinal Na+/C−/taurine transporter. The currents generated by the taurine transporter were studied with a two‐electrode voltage clamp and we recorded the maximal current (Imax), presteady‐state charge transferQ, and membrane capacitanceCm. 8‐BR‐cAMP, a membrane‐permeable activator of the cAMP‐dependent protein kinase (PKA), decreasedImax(41%),Q(41%) andCm(10%). Similarly, 1 μMsn‐1,2‐dioctanoylglycerol (DOG), an activator of the Ca2+Idiacylglycerol‐dependent protein kinase (PKC), decreasedImax(56%),Q(37%), andCm(9%). Calyculin A, a specific inhibitor of protein phosphatases 1 and 2A, also produced effects similar to those of 8‐Br‐cAMP and DOG, and decreasedImax(64%),Q(38%), andCm(10%). We conclude that the taurine transporter is regulated by activators of PKA and PKC, and regulation occurs largely by changes in the number of transporters in the plasma membrane.
Interaction of human cathepsin C with chicken cystatin
Authors: Dolenc Iztok , Turk Boris , Kos Janko , Turk Vito
Published: April 2003

Cathepsin C was purified from human spleen by a rapid procedure, which included homogenization, ammonium sulfate precipitation, gel filtration on Sephacryl S‐200 and finally affinity chromatography on chicken cystatin‐Sepharose. The interaction between cathepsin C and chicken cystatin was further characterized. It was found to be accompanied by a maximum decrease in fluorescence emission intensity at 330 nm. Fluorescence titration showed that human cathepsin C can bind four chicken cystatin molecules. The 4:1 binding stoichiometry was confirmed by titration monitored by the loss of enzyme activity. A non‐competitive‐competitive type of inhibition was determined from a double‐reciprocal Lineweaver‐Burk plot with a K
i value of 0.22 nM for the non‐competitive inhibition.
Localization of reactive tyrosine residues of baker's yeast transketolase
Authors: Kovina Marina , Viryasov Mikhail , Baratova Ljudmila , Kochetov German
Published: April 2003

Baker's yeast transketolase inactivated by tetranitromethane was digested with Staphylococcus aureus V8 protease. Four peptides absorbing at 360 nm were isolated by reverse‐phase HPLC and sequenced. The modified tyrosines were identified as Tyr‐184, Tyr‐210 and Tyr‐370.
IgG immunoglobulins induce activation of the sphingomyelin cycle in HL‐60 cells
Authors: Glick Dvorah , Barenholz Yechezkel
Published: April 2003

In HL‐60 cells signal transduction via sphingomyelin hydrolysis (sphingomyelin cycle) is induced by binding of tumor necrosis factor α (TNFα) to cell surface TNFα receptor. We found that IgG immunoglobulins activate sphingomyelin hydrolysis in plasma membrane of HL‐60 cells, with kinetics similar to that of activation by TNFα. Activation was induced by different IgG isotypes (most of which are irrelevant to known inducers of the sphingomyelin cycle) and also by Fcγ fragments of IgG. The facts that inhibiting the binding of the antibodies to the cell surface by protein A prevents activation of sphingomyelin hydrolysis and that soluble TNF receptor of 55‐kDa subtype (TBP55) inhibits activation, suggest that the mechanism of IgG‐induced sphingomyelin hydrolysis involves binding of IgGs through their Fcγ domain to Fcγ surface receptors which mediate autocrine secretion of TNFα. The latter is responsible for inducing sphingomyelin hydrolysis. This study suggests that TBP55 may be an effective inhibitor of the sphingomyelin cycle.
Interleukin‐1β expression is induced by adherence and is enhanced by Fc‐receptor binding to immune complex in THP‐1 cells
Authors: Cobb Ronald R. , Leslie Molony J.
Published: April 2003

Adherence of monocytes to endothelial cells and subsequently to basement membrane represents the initial steps in monocyte migration from the vasculature to the interstitium. We investigated the role of adhesion to endothelial cells and basement membrane in the induction of the cytokine IL‐1β. We demonstrated that mRNA for IL‐1β is induced in adherent THP‐1 cells, but not in a matrix‐specific manner. Adherence to fibrinogen, however, causes an increase in mRNA for IL‐1β. A background level of IL‐1β mRNA induction was observed in cells adherent to all matrices, including the non‐specific human serum albumin substrate, as compared to non‐adherent cells cultured in teflon troughs. In addition, antibodies to CD11a, CD11b, β1 integrin, VLA4, αvβ3 (VNR), and ICAM‐1 did not induce significant IL‐1β mRNA when THP‐1 cells were adherent to those immunoglobulins. THP‐1 cells adherent to immune complexes of anti‐CD11a, anti‐CD11b, anti‐VLA4, anti‐VNR, and anti‐ICAM‐1 showed greater mRNA induction than cells adherent to primary antibodies alone. THP‐1 cells adherent to non‐specific immune complexes gave the highest level of mRNA induction. Secretion of IL‐1β protein, measured by ELISA at 24 h, was greatest when cells were adherent to immobilized immune complexes or to fibrinogen. Our results demonstrate that a general adherence‐induced increase in IL‐1β gene expression is greatly enhanced by the presence of immune complex.
Quaternary structure of human nucleoside diphosphate kinase isoforms HA and HB in solution
Authors: Schaertl Sabine
Published: April 2003

Human isoforms of nucleoside diphosphate kinase, NDPK‐HA and NDPK‐HB, have been expressed in E. coli and purified. Their apparent molecular masses have been determined by FPLC gel filtration. Absolute molecular masses were measured by equilibrium ultracentrifugation and sedimentation coefficients determined from the sedimentation velocity. Under near‐physiological conditions, NDPK‐HA has a mass of 101 ± 3 kDa, close to that calculated for a hexamer (102.11 kDa), whilst NDPK‐HB has a mass of 71 ± 3 kDa, close to a tetramer (68.67 kDa). The sedimentation coefficients, 5.15 ± 0.2 and 3.41 ± 0.1 × 10−13 s, for HA and HB also indicate a hexamer and a tetramer respectively. This suggests, although the crystal structure shows a hexameric quaternary arrangement [Webb et al. (1995) J. Mol. Biol. 251, 574–587], that NDPK‐HB forms tetramers in solution like bacterial NDPK [Williams et al. (1993) J. Mol. Biol. 234, 1230–1247].
Sequence analysis and distribution of two new human cathepsin L splice variants
Authors: Rescheleit Dietmar K. , Rommerskirch Winfried J. , Wiederanders Bernd
Published: April 2003

Despite elevated cathepsin L mRNA levels in kidney tumors, cathepsin L protein/activity was scarcely detectable in these tumors. As a possible reason, we detected two new splice variants of human cathepsin L mRNAs not identical to those previously reported. Besides the normal ‘full‐length’ mRNA (hCATL‐A) there is one form lacking 27 nucleotides (hCATL‐A I) and another form lacking 90 nucleotides (hCATL‐A II) in exon I. The splice variants do not influence the amino acid sequence of the translational product. hCATL‐A and hCATL‐A I probably form a secondary structure at the 5′ non‐coding sequence not present in hCATL‐A II.
Limulus factor D, a 43‐kDa protein isolated from horseshoe crab hemocytes, is a serine protease homologue with antimicrobial activity
Authors: Kawabata Shun-ichiro , Tokunaga Fuminori , Kugi Yoshie , Motoyama Shiho , Miura Yoshiki , Hirata Michimasa , Iwanaga Sadaaki
Published: April 2003

A glycoprotein (M
r = 43 000) from horseshoe crab hemocytes with antimicrobial activity against Gram‐negative bacteria was purified. The internal peptide sequences coincided exactly with the deduced amino acid sequence of a cDNA clone, designated limulus factor D, which was isolated by screening a hemocyte cDNA library with an anti‐human plasminogen antibody. The open reading frame codes for a precursor of factor D of 394 amino acid residues, including an NH2‐terminal signal sequence. The COOH‐terminal domain of factor D has significant sequence homology with the catalytic domain of mammalian serine proteases, in particular with human tissue plasminogen activator (32% identity), except for the substitution of Ser of the active site triad to Gly. Factor D has a unique NH2‐terminal domain with weak sequence homology with part of the mammalian interleukin‐6 receptor α‐chain. Factor D is likely to have an important role in host defense mechanisms.
Presence of nitric oxide synthase activity in roots and nodules of Lupinus albus
Authors: Cueto Mercedes , Hernández-Perera Octavio , Martín Raquel , Bentura Maria Luisa , Rodrigo José , Lamas Santiago , Golvano Maria Pilar
Published: April 2003

NO is a widespread messenger molecule in physiology. We were interested in investigating whether an NO‐generating system could be present in plants. NO and l‐[14C]citrulline were synthesized by roots and nodules of Lupinus albus in an l‐arginine‐dependent manner. l‐[14C]Citrulline production was inhibited by NG‐monomethyl‐l‐arginine, a nitric oxide synthase antagonist, in a competitive way. NADPH‐diaphorase activity was localized in the vascular bundles in root and nodules, and also in the nodule infected zone. This staining was significantly reduced in the presence of NG‐monomethyl‐l‐arginine. These results indicate the presence of a putative nitric oxide synthase in plants.
The catalytic domain of the cGMP‐dependent protein kinase Iα modulates the cGMP‐binding characteristics of its regulatory domain
Authors: Dostmann Wolfgang R.G. , Koep Nicole , Endres Robert
Published: April 2003

The cGMP‐dependent protein kinase Iα (PKG Iα) possesses two functional moieties, the regulatory and catalytic domains, which reside on a single polypeptide chain. Here we report on the influence of the catalytic domain on the binding of cGMP to the regulatory domain. A deletion mutant, Δ352–670 of PKG Iα, lacking the catalytic domain, was constructed and expressed in E. coli. The purified 38 kDa mutant protein showed strong reactivity toward tryptic proteolysis at residue Arg77. Thus, a double deletion fragment Δ1–77/352–670 PKG Iα, lacking the N‐terminus, was also purified. Both proteins had functional cGMP binding, but differed kinetically from the wild‐type protein. First the affinity constants for cGMP were modulated, second the constructs showed no signs of cooperative cGMP binding and third dimerization of the Δ352–670 mutant was abolished. Our results provide evidence that the catalytic domain forms an intimate interaction with the regulatory domain and modulates the kinetics of cGMP binding.
The light intensity dependence of protochlorophyllide photoconversion and its significance to the catalytic mechanism of protochlorophyllide reductase
Authors: Griffiths W.Trevor , McHugh Thomas , Blankenship Robert E.
Published: April 2003

The light‐dependent step in chlorophyll synthesis by higher plants involves hydrogen transfer from NADPH+to the porphyrin protochlorophyllide catalysed by the photoenzyme protochlorophyllide reductase. The light intensity dependence of the process has been studied in vitro using wheat etioplast membranes. The results suggest that a single photochemical event is involved in the photoconversion. In support of this conclusion we also demonstrate that illumination of these membranes with a train of ultrashort (150 fs) flashes resulted in chlorophyll accumulation. The significance of the findings in terms of possible mechanisms for the reductase are discussed.
Mitral valve surgery and maternal and fetal outcome in valvular heart disease
Authors: Malhotra M. , Sharma J.B. , Arora P. , Batra S. , Sharma S. , Arora R.
Published: April 2003

Objectives: To compare maternal and fetal outcomes in patients with non‐operated valvular heart disease and patients who had surgery before or during pregnancy. Methods: The 308 women with valvular heart disease who delivered in this hospital in the last 8 years were divided into three groups. The 218 (70.7%) women in group 1 had no surgical intervention; the 42 (13.6%) women in group 2 underwent balloon mitral valvotomy during pregnancy; and the 48 (15.5%) women in group 3 had surgical intervention before pregnancy (35 had balloon mitral valvotomy, eight had mitral valve replacement, and five had mitral valve repair). Maternal and fetal outcomes were compared for these three groups. Results: The antenatal events differed significantly: 175 (80.3%), 40 (94.2%), and 46 (95.8%) patients in groups 1, 2 and 3, respectively, had uneventful pregnancies. In group 1, 14 (6.4%) patients had congestive heart failure (P>0.05) and 24 (11%) patients had cardiac arrhythmias, which was statistically significant. The rate of preterm deliveries did not differ significantly among the three groups. The groups did not differ in mean birth weight, mode of delivery, low birth weight, Apgar scores less than 8, stillbirths, neonatal death, or congenital anomalies. Conclusions: Mitral valve surgery before or during pregnancy did not significantly improve maternal and fetal outcomes but decreased adverse events such as congestive heart failure and cardiac arrhythmias. It should be therefore performed only in selected cases.
Prophylactic transcervical amnioinfusion in laboring women with oligohydramnios
Authors: Amin A.F. , Mohammed M.S. , Sayed G.H. , Abdel‐Razik S.
Published: April 2003

Objectives: Evaluation of prophylactic intrapartum amnioinfusion in women with oligohydramnios. Methods: Assiut University Hospital during the period from February 2000 to September 2001, 160 laboring women with oligohydramnios [amniotic fluid index (AFI) ≤5 cm] were randomized into: amnioinfusion and control groups. Inclusion criteria were: term singleton gestation, vertex presentation, cervical dilatation <4 cm, and assuring fetal heart rate (FHR). Trans‐cervical amnioinfusion was done with warmed normal saline. Results: there was a significant increase in AFI after amnioinfusion (P<0.001). The amnioinfusion group showed lower cesarean section rate for fetal distress (P=0.003), lower incidence of abnormal FHR (P=0.006), fewer neonates with Apgar score <7 at 1 min (P<0.001), and 5 min (P=0.009), meconium below vocal cords (P<0.001), umbilical arterial pH<7.1 (P=0.003), and significantly shorter hospital stay (P=0.02). Conclusion: Prophylactic trans‐cervical amnioinfusion is a simple, safe and effective procedure.
Intrauterine development and MNSs blood groups in repeated spontaneous abortion
Authors: Borgiani P. , Nicotra M. , Amante A. , Lucarini N. , Cosmi E. , Bottini E.
Published: April 2003

Objectives: To determine whether the maternal MNSs genotype has an effect on the birth weight and gestation duration of the live offspring of women with repeated primary spontaneous abortion (RSA). Methods: The study sample consisted of 239 healthy white women who had been delivered of a live infant, and 137 women with a history of primary RSA—54 of whom had recently been delivered of a live infant and 83 who had had a spontaneous abortion. Maternal MNSs phenotypes were determined by standard serological methods, and the results were analyzed for relationships between these phenotypes and the mothers’ reproductive status and the infants’ birth weight and gestational age. Analysis of variance, the χ2‐test of independence, and the Mantel–Haenszel test for linear association were performed for data analysis. Results: Infants born to mothers with the Ss genotype showed significantly lower birth weight and gestational duration compared with the infants of mothers with other genotypes. Additionally, the MNSs haplotype was found to be associated with birth weight. Conclusions: Previous studies have shown that the MNSs system influences the gestational age of aborted fetuses in cases of RSA. The present study supports the hypothesis that this genetic factor influences intrauterine growth and development in women experiencing RSA.
Biochemical markers of bone turnover during hormone replacement therapy
Authors: Masahashi T , Negoro Y , Kuroki T , Asai M , Noguchi M , Nakanishi M
Published: April 2003

Objective: To assess the clinical usefulness of bone turnover markers, including serum osteocalcin (OC), urinary pyridinoline (Pyr) and deoxypyridinoline (D‐Pyr), in monitoring and predicting bone response to hormone replacement therapy (HRT). Method: The relationships between baseline levels or changes in markers and change in lumbar bone mineral density were examined in 21 surgically‐induced postmenopausal women. Results: Levels of OC, Pyr and D‐Pyr in the estrogen effective group (responders) significantly decreased during HRT and baseline levels of Pyr and D‐Pyr in responders were significantly higher than those in premenopausal women. Conclusion: Bone turnover markers were useful in monitoring the bone effect of HRT and baseline levels of markers reflect subsequent bone response to HRT.
A 10,000-year high-resolution diatom record from Pilkington Bay, Lake Victoria, East Africa
Authors: Stager J. Curt , Cumming Brian F. , Meeker L. David
Published: April 2003

A new diatom record from Lake Victoria’s Pilkington Bay, subsampled at 21- to 25-year intervals and supported by 20 AMS dates, reveals a ∼10,000 calendar year environmental history that is supported by published diatom and pollen data from two nearby sites. With their chronologies adjusted here to account for newly documented ancient carbon effects in the lake, these three records provide a coherent, finely resolved reconstruction of Holocene climate change in equatorial East Africa. After an insolation-induced rainfall maximum ca. 8800–8300 cal yr B.P., precipitation became more seasonal and decreased abruptly ca. 8200 and 5700 yr B.P. in apparent association with northern deglaciation events. Century-scale rainfall increases occurred ca. 8500, 7000, 5800, and 4000 yr B.P. Conditions after 2700 yr B.P. were generally similar to those of today, but major droughts occurred ca. 1200–600 yr B.P. during Europe’s Medieval Warm Period.
Gamma interferon as an antifibrosis agent in skeletal muscle
Authors: Foster William , Li Yong , Usas Arvydas , Somogyi George , Huard Johnny
Published: April 2003

Muscle injuries are a common problem in sports medicine. Skeletal muscle can regenerate itself, but the process is both slow and incomplete. Previously we and others have used growth factors to improve the regeneration of muscle, but the muscle healing was impeded by scar tissue formation. However, when we blocked the fibrosis process with decorin, an antifibrosis agent, we improved the muscle healing. Here we show that γinterferon (γINF)—a cytokine that inhibits the signaling of transforming growth factor β1 (TGFβ1), a fibrotic stimulator—reduces fibrosis formation and improves the healing of lacerated skeletal muscle. With γINF treatment, the growth rate of muscle‐derived fibroblasts was reduced and the level of fibrotic protein expression induced by TGFβ1 (including TGFβ1, vimentin, and α‐smooth muscle actin) was down‐regulated in vitro. In a mouse laceration model, the area of fibrosis decreased when γINF was injected at either 1 or 2 weeks after injury. More importantly, the injection of γINF at either 1 or 2 weeks post‐injury was found to improve muscle function in terms of both fast‐twitch and tetanic strength. This study demonstrates that γINF is a potent antifibrosis agent that can improve muscle healing after laceration injury. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
In Pursuit of the Russian Presidency: Why and How Yeltsin Won the 1996 Presidential Election
Authors: Brudny Yitzhak M.
Published: April 2003

This article seeks to explain why Boris Yeltsin was able to win I996 Russian presidential election despite prolonged economic crisis and the war in Chechnya. The paper advances the argument which emphasizes Yeltsin's ability to recreate political and social alliances which were crucial to his previous electoral successes, on the one hand, and poor electoral strategy and political beliefs of Yeltsin's main challenger, the head of the Communist Party of the Russian Federation Gennady Zyuganov, on the other. In particular, the paper highlights Yeltsin's campaign strategy of turning the election into a referendum on communism rather on his own record and the success of his two candidates only strategy. The paper also argues that Zyuganov communist-nationalist, rather than social-democratic, world view determined his electoral strategy and played a major role in his electoral defeat.
Centralization in the Marxist and in the Leninist tradition
Authors: Kautsky John H.
Published: April 2003

The very different positions of Marxists and Leninists on the issue of centralization of political and economic institutions show that, though using the same terminology, they were committed to different ideologies. Leninists were modernizing revolutionaries in underdeveloped countries seeking their rapid industrialization. They relied on centralized revolutionary movements, which, in power, formed centralized bureaucracies that advanced industrialization through mass persuasion, regimentation and terror as well as central planning.

Marxists, associated with multifarious labor movements in industrialized countries, hoped to advance and empower the working class. Marx and Engels were vague on the subject of centralization, but condemned bureaucracy and came to favor the decentralization identified with the Paris Commune. Karl Kautsky and Otto Bauer advocated the operation of industry by local governments, cooperatives and trade unions and only minimal state ownership and sharply attacked bureaucracy. Policies of centralization were appropriate to the character and goals of Leninist movements but inappropriate to those of Marxist ones.
‘No‐load’ dividend reinvestment plans
Authors: Steinbart Paul John , Swanson Zane
Published: April 2003

This article examines firms' motivations for offering investors the opportunity to purchase initial shares of stock directly from the company by joining the firm's dividend reinvestment plan (DRP). The results of both a telephone survey of Investor Relations Departments and analysis of plan prospectuses indicate that firms offer such no‐load DRPs with the objective of broadening their shareholder base. Moreover, additional analysis shows that firms which implement no‐load DRPs subsequently experience a significant decrease in the number of shares held per shareholder. Thus, no‐load DRPs do appear to be successful in broadening a firm's shareholder base.
Obstetric Triage Revisited: Update on Non‐Obstetric Surgical Conditions in Pregnancy
Authors: Angelini Diane J.
Published: April 2003

New findings and diagnostic advances warrant revisiting key features of acute non‐obstetric abdominal pain in pregnancy. Four of the most frequently seen conditions warranting surgical intervention are: appendicitis, cholecystitis, pancreatitis, and bowel obstruction. Because pregnancy often masks abdominal complaints, effectively assessing and triaging abdominal pain in pregnant women can be difficult. Working in obstetric triage settings and triaging obstetric phone calls demand continual updating of abdominal assessment knowledge and clinical skills.
Berufliche Interessenkongruenz und das Erleben im Studium
Authors: Rolfs Henning , Schuler Heinz
Published: April 2003

Zusammenfassung. Nach der Kongruenzhypothese aus John Hollands Theorie beruflicher Interessen soll sich die Passung zwischen den Interessen einer Person und den Merkmalen ihrer beruflichen Umwelt auf die individuelle Arbeits- und Studienzufriedenheit auswirken. Empirische Untersuchungen zu diesem Zusammenhang kommen allerdings zu uneinheitlichen und insgesamt weniger optimistischen Ergebnissen, werden aber auch aufgrund methodischer und theoretischer Beschränkungen kritisiert. In zwei Studien wird die Kongruenzhypothese für unterschiedliche Konzeptionen von Interessenkongruenz getestet. Diese Konzeptionen unterscheiden sich besonders darin, ob die Kongruenz intraindividuell und typologisch oder interindividuell und dimensional hergeleitet wird. In Studie 1 zeigen sich in einem Längsschnittdesign an einer studentischen Stichprobe (Nt1 = 119, Nt2 = 98) substanzielle Zusammenhänge zwischen der Interessenkongruenz und dem Erleben im Studium. Diese Zusammenhänge fallen besonders für die dimensional und interindividuell hergeleitete Kongruenz hoch aus. In Studie 2 wird die Betrachtung der Beziehung zwischen der Interessenkongruenz und dem Erleben erweitert um individuelle Dispositionen. Dazu werden an der Studentenstichprobe die eigenständigen Validitäten der Kongruenz gegenüber den Merkmalen emotionale Stabilität, Extraversion, Verträglichkeit und Gewissenhaftigkeit in der Vorhersage des Erlebens überprüft. Es ergeben sich für die typologischen Kongruenzen keine bis niedrige inkrementelle Validitäten, für die dimensionale Kongruenz hingegen hohe inkrementelle Validität.
Konzeption und Evaluation eines Trainings zum Umgang mit unfairem Argumentieren in Organisationen
Authors: Mischo Christoph , Groeben Norbert , Christmann Ursula , Flender Jürgen
Published: April 2003

Zusammenfassung. In diesem Beitrag werden die Konzeption und Evaluation eines Trainings vorgestellt, das zu einer Verbesserung der Argumentationskultur - gerade auch in organisationalen Kontexten - beitragen soll. Die Trainingskonzeption baut praktisch vollständig auf grundlagenwissenschaftlichen Befunden auf und verfolgt das Ziel, für verschiedene Formen argumentativer Unintegrität zu sensibilisieren und situativ angemessene Reaktionsweisen zu vermitteln. Die modulartig aufgebaute Konzeption behandelt das Phänomen unintegren Argumentierens in sechs Trainingsdimensionen, deren zugrunde liegende theoretischen und empirischen Befunde kurz umrissen werden. Bei der didaktischen Umsetzung der Konzeption werden induktive vs. deduktive und entdeckende vs. rezeptive Lernformen unterschieden. Die Durchführung des Trainings erfolgte mit 89 Personen (überwiegend Mitarbeiter/innen von Verwaltungsinstitutionen). Im Rahmen eines Kontrollgruppendesigns sprechen die Ergebnisse der Produktevaluation für die Wirksamkeit des Trainings. Die Resultate der Prozessevaluation geben Aufschluss über den Beitrag der einzelnen Trainingsdimensionen an der Gesamteffektivität.
Estimating the Valence of Single Stimuli: A New Variant of the Affective Simon Task
Authors: Voß Andreas , Rothermund Klaus , Wentura Dirk
Published: April 2003

Abstract. In this article, a modified variant of the Affective Simon Task (AST; De Houwer & Eelen, 1998 ) is presented as a measure of implicit evaluations of single stimuli. In the AST, the words “good” or “bad” have to be given as responses depending on the color of the stimuli. The AST was combined with an evaluation task to increase the salience of the valence of the presented stimuli. Experiment 1 investigated evaluations of schematic faces showing emotional expressions. In Experiment 2 we measured the valence of artificial stimuli that acquired valence in a game context during the experiment. Both experiments confirm the validity of the modified AST. The results also revealed a dissociation between explicit and implicit evaluations.
Endothelium dysfunction in LDL receptor knockout mice: a role for H2O2
Authors: Rabelo Luíza A , Cortes Steyner F , Alvarez‐Leite Jacqueline I , Lemos Virgínia S
Published: April 2003

In this study, the role of endogenous H2O2 as an endothelium‐dependent relaxant factor was characterised in aortas from C57BL/6J and LDL receptor‐deficient mice (LDLR−/−).

Aortic rings from LDLR−/− mice showed impaired endothelium‐dependent relaxation to acetylcholine (ACh; 0.001–100 μM) and to the Ca2+ ionophore A23187 (0.001–3 μM) compared with aortic rings from control mice. Endothelium‐independent relaxation produced by the NO donor, 3‐morpholino‐sydnonimine (SIN‐1) was not different between strains.

Pretreatment of vessels with L‐NNA (100 μM) or L‐NNA (100 μM) plus L‐NAME (300 μM) plus haemoglobin (10 μM) markedly decreased, but did not abolish the relaxation to ACh in control mice. In the aortas from LDLR−/− mice treated with L‐NNA (100 μM), ACh induced a contractile effect. Catalase (800 and 2400 U ml−1) shifted to the right the endothelium‐dependent relaxation to ACh in aortas from control but not from LDLR−/− mice. Aminotriazole (50 mM), which inhibits catalase, abolished its effect on control mice. Treatment of vessels with L‐NNA and catalase abolished vasorelaxation induced by ACh. Indomethacin (10 μM) did not modify the concentration–response curve to ACh. Superoxide dismutase (300 U ml−1) did not change ACh‐induced relaxation in both strains.

Exogenous H2O2 produced a concentration‐dependent relaxation in endothelium‐denuded aortic rings, which was not different between strains.

It is concluded that H2O2 greatly contributes to relaxation to ACh in aorta from control mice. Endothelial‐dependent relaxation to ACh is impaired in LDLR−/− mice. Reduced biosynthesis or increased inactivation of H2O2 is the possible mechanism responsible for endothelial dysfunction in aortas of atherosclerosis‐susceptible LDLR−/− mice.

British Journal of Pharmacology (2003) 138, 1215–1220. doi:10.1038/sj.bjp.0705164
5‐HT7 receptors mediate the inhibitory effect of 5‐HT on peristalsis in the isolated guinea‐pig ileum
Authors: Tuladhar Bishwa R , Ge Lanbo , Naylor Robert J
Published: April 2003

The study was undertaken to investigate the 5‐HT receptor mediating the inhibitory effect of 5‐HT on peristalsis in the guinea‐pig isolated ileum. The facilitatory and inhibitory effects were measured as the decrease and increase, respectively, in the intraluminal pressure required to trigger peristalsis. In the presence of 5‐HT2/3&4 receptor antagonists ketanserin (0.1 μM), granisetron (1 μM) and SB‐204070 (1 μM), a cumulative addition (0.1–100 μM) of 5‐HT or 5‐carboxamidotryptamine, but not 2‐methyl‐5‐HT produced a concentration‐dependent increase in the threshold required to trigger peristalsis. The 5‐HT7 receptor selective antagonist SB‐269970‐A (0.01–1 μM) or methiothepin (0.01–0.1 μM) concentration‐dependently antagonised this response to 5‐HT. SB‐269970‐A (1 μM) and methiothepin (1 μM) were also able to restore peristalsis in tissues in which peristalsis was inhibited by a prior addition of 30 μM of 5‐HT. The results indicate an involvement of 5‐HT7 receptors in the inhibitory effect of 5‐HT on peristalsis in the guinea‐pig ileum.

British Journal of Pharmacology (2003) 138, 1210–1214. doi:10.1038/sj.bjp.0705184
Comparison at a Distance
Authors: Danilova Marina V , Mollon John D
Published: April 2003

The visual system is known to contain hard-wired mechanisms that compare the values of a given stimulus attribute at adjacent positions in the visual field; but how are comparisons performed when the stimuli are not adjacent? We ask empirically how well a human observer can compare two stimuli that are separated in the visual field. For the stimulus attributes of spatial frequency, contrast, and orientation, we have measured discrimination thresholds as a function of the spatial separation of the discriminanda. The three attributes were studied in separate experiments, but in all cases the target stimuli were briefly presented Gabor patches. The Gabor patches lay on an imaginary circle, which was centred on the fixation point and had a radius of 5 deg of visual angle. Our psychophysical procedures were designed to ensure that the subject actively compared the two stimuli on each presentation, rather than referring just one stimulus to a stored template or criterion. For the cases of spatial frequency and contrast, there was no systematic effect of spatial separation up to 10 deg. We conclude that the subject's judgment does not depend on discontinuity detectors in the early visual system but on more central codes that represent the two stimuli individually. In the case of orientation discrimination, two naïve subjects performed as in the cases of spatial frequency and contrast; but two highly trained subjects showed a systematic increase of threshold with spatial separation, suggesting that they were exploiting a distal mechanism designed to detect the parallelism or non-parallelism of contours.
Saccadic Suppression of Displacement: Effects of Illumination and Background Manipulation
Authors: MacAskill Michael R , Jones Richard D , Anderson Tim J
Published: April 2003

In contrast to other functions which are suppressed during saccades, saccadic suppression of displacement (SSD—a decrease in sensitivity to visual displacements during saccades) has often been considered to be due to efferent processes rather than to visual masking. The aim of this study was to explicitly assess the importance of visual conditions in SSD. In two experiments, a small computer-generated target made random horizontal jumps. An infrared eye tracker was used to detect the saccade toward the new position, triggering a smaller centripetal displacement of the target. Subjects reported awareness of these intrasaccadic displacements by pressing a key. In the first experiment, the task was performed in both a well-lit environment and in darkness. In the second experiment these conditions were replicated and additional factors such as the contrast of the background and the effect of moving the target spot alone or the target plus the entire background were investigated. Unlike other forms of saccadic suppression, SSD was stronger in the dark, although subjects also had a greater bias to report detections in that condition. Other background manipulations had no effect. The effect of ambient lighting on SSD is small and subtle. Effects of other background manipulations may be overridden by the focusing of attention on a small moving target.
Attentional Modulation of Self-Motion Perception
Authors: Kitazaki Michiteru , Sato Takao
Published: April 2003

Attentional effects on self-motion perception (vection) were examined by using a large display in which vertical stripes containing upward or downward moving dots were interleaved to balance the total motion energy for the two directions. The dots moving in the same direction had the same colour, and subjects were asked to attend to one of the two colours. Vection was perceived in the direction opposite to that of non-attended motion. This indicates that non-attended visual motion dominates vection. The attentional effect was then compared with effects of relative depth. Clear attentional effects were again found when there was no relative depth between dots moving in opposite directions, but the effect of depth was much stronger for stimuli with a relative depth. Vection was mainly determined by motion in the far depth plane, although some attentional effects were evident even in this case. These results indicate that attentional modulation for vection exists, but that it is overridden when there is a relative depth between the two motion components.
Yearly measurements of blood lead in Swedish children since 1978: an update focusing on the petrol lead free period 1995–2001: Figure 1
Authors: Strömberg U , Lundh T , Schütz A , Skerfving S
Published: April 2003

Background and Aims:To assess blood lead concentrations (B-Pb) in children not exposed to petrol lead. In a previous paper we reported the results for the period 1978–94 (2441 children measured). A substantial decrease of B-Pb was found, which reflected a beneficial effect of gradual banning of petrol lead. Since 1994, petrol sold in Sweden has not contained lead.

Methods:In the south of Sweden, each year from 1995 to 2001, B-Pb was measured in 329 boys and 345 girls, aged 7–11 years.

Results:The geometric mean (GM) of B-Pb was 21 (range 6–80) μg/l. There was no consistent change of B-Pb from 1995 to 2001. Children living near a lead smelter had raised B-Pb (GM 24 μg/l, range 11–80). Passive smoking, but not age and sex, influenced B-Pb significantly.

Conclusions:B-Pb in Swedish children, no longer exposed to petrol lead, seems to have stabilised at an average level close to 20 μg/l (provided there is no nearby industrial lead emission).
FINALLY NEUTRINO HAS MASS
Authors: BILENKY S. M. , GIUNTI C. , KIM C. W.
Published: April 2003

The present status of the problem of neutrino mass, mixing and neutrino oscillations is briefly summarized. The evidence for oscillations of atmospheric neutrinos found recently in the Super-Kamiokande experiment is discussed. Indications in favor of neutrino oscillations obtained in solar neutrino experiments and in the accelerator LSND experiment are also considered. Implications of existing neutrino oscillation data for neutrino masses and mixing are discussed.
A PATH-INTEGRAL APPROACH FOR BOSONIC EFFECTIVE THEORIES FOR FERMION FIELDS IN FOUR AND THREE DIMENSIONS
Authors: BOTELHO LUIZ C. L.
Published: April 2003

We study four-dimensional effective bosonic field theories for (A) massive fermion field in the infrared region and (B) massive fermion in the ultraviolet region by using an appropriate fermion path integral chiral variable change and (C) Polyakov's Fermi–Bose transmutation in the 3D-Abelian Thirring model and its triviality as a quantum field theory.
FINITE T MESON CORRELATIONS AND QUARK DECONFINEMENT
Authors: BLASCHKE D. , BURAU G. , KALINOVSKY YU. L. , MARIS P. , TANDY P. C.
Published: April 2003

The finite temperature spatial [Formula: see text] correlation modes in the π and ρ channels are studied with the rainbow-ladder truncated quark Dyson–Schwinger equation and Bethe–Salpeter equation in the Matsubara formalism. To retain the finite range of the effective interaction while facilitating summation over fermion Matsubara modes necessary to ensure continuity at T=0, a separable kernel is used. The model is fixed by T=0 properties and it implements dynamical chiral symmetry breaking and quark confinement. Transition temperatures for deconfinement (Td) and chiral restoration (Tc) are identified. Above and below these transitions we study Mπ(T), fπ(T) and the three-space transverse and longitudinal masses [Formula: see text] and [Formula: see text]. We also study the intrinsic T-dependence of the electromagnetic coupling constant gρ(T) and the strong coupling constant gρππ(T). For both this model and a related semi-analyticinfrared dominant model, we analyze the high T behavior of the obtained masses in comparison to the M(T)→2πT behavior found in lattice QCD simulations.
AN ANALYTICAL SOLUTION OF THE COSMIC RAYS TRANSPORT EQUATION IN THE PRESENCE OF THE GEOMAGNETIC FIELD
Authors: GIBILISCO MARINA
Published: April 2003

In this work, I study the propagation of cosmic rays inside the magnetic field of the earth, at distances d≤500 km from its surface; at these distances, the geomagnetic field deeply influences the diffusion motion of the particles.

I compare the different effects of the interplanetary and of the geomagnetic fields, by also discussing their role in the cosmic rays transport equation; then, I present an analytical method to solve such an equation through a factorization technique. In this way, it is possible to reduce the initial second-order, partial derivatives differential equation into a more simple, Riccati-like equation, which, finally, can be solved by using standard Runge–Kutta–Merson routines.

The results here obtained may have some interest in view of the future AMS (Alpha Magnetic Spectrometer) data, which will be collected at an altitude of about 400 km above the earth surface. Moreover, the study of the propagation of particles having different charges and masses may also help in testing the presence of antimatter and antinuclei in cosmic rays; some theoretical implications of this possibility will also be discussed in the light of the perspectives opened by the AMS Experiment.
PHASE TRANSITION IN THE HIGGS MODEL OF SCALAR FIELDS WITH ELECTRIC AND MAGNETIC CHARGES
Authors: LAPERASHVILI L. V. , NIELSEN H. B.
Published: April 2003

Using a one-loop renormalization group improvement for the effective potential in the Higgs model of electrodynamics with electrically and magnetically charged scalar fields, we argue for the existence of a triple (critical) point in the phase diagram ([Formula: see text]), where λ run is the renormalized running self-interaction constant of the Higgs scalar monopoles and g run is their running magnetic charge. This triple point is a boundary point of three first-order phase transitions in the dual sector of the Higgs scalar electrodynamics: The "Coulomb" and two confinement phases meet together at this critical point. Considering the arguments for the one-loop approximation validity in the region of parameters around the triple point A we have obtained the following triple point values of the running couplings: [Formula: see text], which are independent of the electric charge influence and two-loop corrections to [Formula: see text] with high accuracy of deviations. At the triple point the mass of monopoles is equal to zero. The corresponding critical value of the electric fine structure constant turns out to be [Formula: see text] by the Dirac relation. This value is close to the [Formula: see text], which in a U(1) lattice gauge theory corresponds to the phase transition between the "Coulomb" and confinement phases. In our theory for α ≥ α crit there are two phases for the confinement of the electrically charged particles. The results of the present paper are very encouraging for the antigrand unification theory which was developed previously as a realistic alternative to SUSY GUT's. The paper is also devoted to the discussion of this problem.
STATUS OF STANDARD MODEL PARAMETERS
Authors: BARKER ANTHONY R.
Published: April 2003

Recent experimental progress in determining the parameters of the electroweak sector of the Standard Model is summarized. The principal topics addressed include the precision determination of electroweak parameters using LEP and SLD data at the Z0 pole, measurements of the W mass by LEP-II, CDF, and D0, and determination of the elements of the CKM matrix using a variety of experimental methods.
Physics Beyond The Standard Model: Experimental
Authors: Culbertson R. L.
Published: April 2003

The search for physics beyond the Standard Model includes Technicolor particles, Higgs Bosons, compositeness, many variations of Supersymmetry, large extra dimensions, model-independent searches for anomalies, and other topics. This article reports a subset of these ongoing searches at the high-energy colliders, Tevatron, HERA and LEP.
NEUTRINO PHYSICS: AN EXPERIMENTAL OVERVIEW
Authors: SCHOLBERG KATE
Published: April 2003

The field of neutrino physics is currently very exciting, with several recent results pointing to new physics. I will give an overview of the current experimental situation, focusing primarily on neutrino oscillation results. The data are not entirely consistent however, and puzzles remain. I will then review the new experiments which are poised to solve the outstanding puzzles.
FUTURE SUMMARY
Authors: WILCZEK FRANK
Published: April 2003

We are emerging from a period of consolidation in particle physics. Its great, historic achievement was to establish the Theory of Matter. This Theory will serve as our description of ordinary matter under ordinary conditions — allowing for an extremely liberal definition of "ordinary" — for the foreseeable future. Yet there are may indications, ranging from the numerical to the semimystical, that a new fertile period lies before us. We will discover compelling evidence for the unification of fundamental forces and for new quantum dimensions (low-energy supersymmetry). We will identify new forms of matter, which dominate the mass density of the Universe. We will achieve much better fundamental understanding of the behaviour of matter in extreme astrophysical and cosmological enviroments. Lying beyond these expectations, we can identify deep questions that seemto call for ideas outside our present grasp. And there is still plenty of room for surprises.
Measurements of Diffractive Vector-Meson Photoproduction at High Momentum Transfer from the ZEUS Experiment at HERA
Authors: Crittendenr James A.
Published: April 2003

We discuss recent preliminary results on the diffractive photoproduction of ρ0, ϕ, and J/ψ mesons at high momentum transfer reported by the ZEUS collaboration at HERA. A special-purpose calorimeter served to tag the quasi-real photons (Q2<0.01 GeV 2) in the process γ+p→ VM +Y, where Y represents a dissociated state of the proton. The resulting range in photon-proton center-of-mass energy extends from 80 to 120 GeV. The differential cross sections [Formula: see text] were obtained in the region |t| > 1.2 GeV 2, where t denotes the squared momentum transfer to the proton. The measurements provide good sensitivity to the observed power-law dependence [Formula: see text]. Over the region in momentum transfer covered by the data, the power is found to be approximately n ≃ 3 for ρ0 and ϕ photoproduction, and approximately n ≃ 2 for J/ψ photoproduction.
QCD MEASUREMENTS IN PHOTON-PHOTON COLLISIONS AT LEP
Authors: CSILLING ÁKOS
Published: April 2003

An overview of the latest results of the LEP collaborations on QCD measurements in photon-photon collisions is presented, including measurements of the total hadronic cross-section, the production of heavy quarks and dijets and the structure functions of real and virtual photons.
NEXT-TO-LEADING ORDER CALCULATION OF THE COLOR-OCTET 3S1 GLUON FRAGMENTATION FUNCTION FOR HEAVY QUARKONIUM
Authors: LEE JUNGIL
Published: April 2003

Next-to-leading order corrections to fragmentation functions in a light-cone gauge are discussed. This gauge simplifies the calculation by eliminating many Feynman diagrams at the expense of introducing spurious poles in loop integrals. As an application, the short-distance coefficients for the color-octet 3S1 term in the fragmentation function for a gluon to split into polarized heavy quarkonium states are re-calculated to order [Formula: see text]. We show that the ill-defined spurious poles cancel and the appropriate prescriptions for the remaining spurious poles can be determined by calculating a subset of the diagrams in the Feynman gauge. Our answer agrees with the recent calculation of Braaten and Lee in the Feynman gauge, but disagrees with another previous calculation.
MEASUREMENT OF THE FORWARD-BACKWARD ASYMMETRY OF B AND C QUARK AT THE Z PEAK
Authors: Paganoni Marco
Published: April 2003

The forward-backward asymmetries of the processes [Formula: see text] and [Formula: see text] were measured from a sample of hadronic Z decays collected by the DELPHI experiment between 1993 and 1995. Enriched samples of [Formula: see text] and [Formula: see text] events were obtained using lifetime information. The tagging of b and c quarks in these samples was based on the semileptonic decay channels b/c → X + μ and b/c → X + e combined with the charge flow information in the hemisphere opposite to the lepton. Averaging the results presented in this paper with those already published with 1991 and 1992 DELPHI data sample, the following pole asymmetries were obtained: [Formula: see text]
ELECTROWEAK RADIATIVE CORRECTIONS TO W AND Z BOSON PRODUCTION AT HADRON COLLIDERS
Authors: BAUR ULRICH , WACKEROTH DOREEN
Published: April 2003

For the envisioned high precision measurement of the W boson mass at the Tevatron and LHC it is crucial that the theoretical predictions for the W and Z production processes are under control. We briefly summarize the status of the electroweak radiative corrections to [Formula: see text] and [Formula: see text], γ → l+l- (l = e, μ), and present some numerical results.
TOP MASS MEASUREMENT AND BOTTOM FRAGMENTATION AT THE LHC
Authors: CORCELLA GENNARO
Published: April 2003

We show some recent HERWIG results related to the top quark mass reconstruction at the LHC and discuss possible improvements for studies of the bootom quark fragmentation function in the top decay.
Hölder Inequalities and QCD Sum-Rule Bounds on the Masses of Light Quarks
Authors: Steele T. G.
Published: April 2003

QCD Laplace Sum-Rules must satisfy a fundamental Hölder inequality if they are to consistently represent an integrated hadronic spectral function. The Laplace sum-rules of pion currents is shown to violate this inequality unless the u and d quark masses are sufficiently large, placing a lower bound on mu+md, the SU(2)-invariant combination of the light-quark masses.