bluuebunny/crossref_metadata_2025 huggingface dataset:
Why Did UK Manufacturing Productivity Growth Slow Down in the 1970s and Speed Up in the 1980s?
Authors: Cameron Gavin
Published: November 2003

After a dramatic slowdown in the 1970s, productivity growth in UK manufacturing in the 1980s returned to something like its pre‐slowdown trend. This paper constructs a quarterly dynamic model of total factor productivity growth in UK manufacturing using cointegration techniques, correcting for a variety of measurement biases. The elasticity of output with respect to R&D capital is estimated at between 0.2 and 0.3, with human capital playing a positive and significant role. The paper also determines how much of the UK productivity slowdown in the 1970s was due to the mis‐measurement of output and the business cycle and how much was due to structural changes. The answer appears to be about half and half.
Inequality Aversion versus Risk Aversion
Authors: Kroll Yoram , Davidovitz Liema
Published: November 2003

Inequality aversion and risk‐aversion are widely assumed in economic models; however existing economic literature fails to distinguish between the two. This paper presents methodology and a laboratory experiment, which separates inequality aversion from risk aversion. In a set of laboratory experiments, subjects had to choose between two risky alternatives which pay meaningful prizes with the same individual risk but different levels of egalitarianism. Thus, the choice of the more egalitarian alternative implies a higher level of inequality aversion. The experiment was conducted among children, some of whom live on a communal system (kibbutz) and some in the city.
Inequality in the Early Cognitive Development of British Children in the 1970 Cohort
Authors: Feinstein Leon
Published: November 2003

This paper develops an index of development for British children in the 1970 cohort, assessed at 22 months, 42 months, 5 years and 10 years. The score at 22 months predicts educational qualifications at age 26 and is related to family background. The children of educated or wealthy parents who scored poorly in the early tests had a tendency to catch up, whereas children of worse‐off parents who scored poorly were extremely unlikely to catch up and are shown to be an at‐risk group. There is no evidence that entry into schooling reverses this pattern.
The Ricardo Effect: Its Meaning and Validity
Authors: Gehrke Christian
Published: November 2003

This paper is concerned with the meaning and validity of the ‘Ricardo effect’. It is shown that the machinery substitution effect contemplated by David Ricardo (a) is not caused by a rise in the real wage rate, (b) is independent of the so‐called ‘price effect’, and (c) presupposes very special assumptions about the available set of production methods. The paper also investigates whether Ricardo's machinery substitution argument anticipates the principle of factor substitution with regard to capital and labour in marginalist theory.
A Simple Apparatus for Optical Polarization Experiments
Authors: Krieble Kelly , Powlette Joseph L.
Published: November 2003

The phenomenon of polarization is usually covered, although very briefly, in most introductory college and high school physics classes. Experiments such as Malus's law are often performed with inexpensive linear polarization filters or lenses from polarized sunglasses. Investigations of more complex forms of polarization, using retarders such as quarter-wave plates (QWPs) and half-wave plates (HWPs), are often omitted because the acquisition of equipment necessary for multiple setups can be cost-prohibitive. We present here a simple rotational apparatus for accurate polarization measurements and applications using inexpensive substitutes of QWP and HWP for use with common laser wavelengths.
HYPERFINE INTERACTION STUDIES OF Co2+ SUBSTITUTED Li-Sb FERRITE SYSTEM
Authors: RADHAPIYARI LAISHRAM , PRAKASH CHANDRA , PHANJOUBAM SUMITRA , SARMA H. N. K.
Published: November 2003

Mössbauer investigations have been carried out for the system Li 0.6-0.5x Co x Sb 0.1- Fe 2.3-0.5x O 4 with 0.0≤x≤1.0, x in steps of 0.2. The observed variation of the various Mössbauer parameters like isomershift, quadrupole splitting, nuclear magnetic field and linewidth are explained in terms of cation distribution and superexchange interaction.
CORRECTION-TO-SCALING OF RANDOM WALKS IN DISORDERED MEDIA
Authors: LEE SANG B.
Published: November 2003

We study the correction to scaling of the rms displacements of random walks in disordered media consisted of connected networks of the lattice percolation in two, three, and four dimensions. The two types of ensemble averages, i.e. an infinite-network average of random walks starting from an infinite network and an all-cluster average starting from any occupied site, are investigated using both the myoptic ants and the blind ants models. We find that the rms displacements exhibit strong nonanalytic corrections in all dimensions. The correction exponent δ defined by the rms displacement of t-step random walks via Rt=At1/d w (1+Bt-δ+Ct-1+⋯) was found as δ≃0.39, 0.27, and 0.27 for, respectively, two, three, and four dimensions for an infinite-network average, and δ≃0.37, 0.28, and 0.24 for an all-cluster average.
MOMENTUM DISTRIBUTION OF ITINERANT ELECTRONS IN THE ONE-DIMENSIONAL FALICOV–KIMBALL MODEL
Authors: FARKAŠOVSKÝ PAVOL
Published: November 2003

The momentum distribution nk of itinerant electrons in the one-dimensional Falicov–Kimball model is calculated for various ground-state phases. In particular, we examine the periodic phases with period two, three and four (that are ground-states for all Coulomb interactions) as well as the phase separated states (that are ground states for small Coulomb interactions). For all periodic phases examined the momentum distribution is a smooth function of k with no sign of any discontinuity or singular behavior at the Fermi surface k=kF. An unusual behavior of nk (a local maximum) is found at k=3kF for electron concentrations outside half-filling. For the phase separated ground states the momentum distribution nk exhibits discontinuity at k=k0<kF. This behavior is interpreted in terms of a Fermi liquid.
FINITE-SIZE SPIN-WAVE THEORY OF A COLLINEAR ANTIFERROMAGNET
Authors: CAPRIOTTI LUCA
Published: November 2003

The ground-state and low-energy properties of the two-dimensional J1-J2 Heisenberg model in the collinear phase are investigated using finite-size spin-wave theory [Q. F. Zhong and S. Sorella, Europhys. Lett.21, 629 (1993)], and Lanczos exact diagonalizations. For spin one-half — where the effects of quantization are the strongest — the spin-wave expansion turns out to be quantitatively accurate for J2/J1≳0.8. In this regime, both the magnetic structure factor and the spin susceptibility are very close to the spin-wave predictions. The spin-wave estimate of the order parameter in the collinear phase, m†≃0.3, is in remarkable agreement with recent neutron scattering measurements on Li 2 VOSiO 4.
THE PRICING OF EXOTIC OPTIONS BY MONTE–CARLO SIMULATIONS IN A LÉVY MARKET WITH STOCHASTIC VOLATILITY
Authors: SCHOUTENS WIM , SYMENS STIJN
Published: November 2003

Recently, stock price models based on Lévy processes with stochastic volatility were introduced. The resulting vanilla option prices can be calibrated almost perfectly to empirical prices. Under this model, we will price exotic options, like barrier, lookback and cliquet options, by Monte–Carlo simulation. The sampling of paths is based on a compound Poisson approximation of the Lévy process involved. The precise choice of the terms in the approximation is crucial and investigated in detail. In order to reduce the standard error of the Monte–Carlo simulation, we make use of the technique of control variates. It turns out that there are significant differences with the classical Black–Scholes prices.
Treatment of Chronic Heart Failure by Biventricular Pacing: Is It Here to Stay?
Authors: Piepoli Massimo F. , Villani Giovanni Q. , Capucci Alessandro
Published: November 2003

In patients with advanced chronic heart failure, characterised by prolonged QRS duration and impaired cardiac contractility, decreasing dyssynchrony by biventricular pacing seems to improve exercise tolerance (6-min walk distance), symptoms (New York Health Association class) and quality-of-life scores. Although the results of several reports have been consistent, the numbers of patients studied were small, and many of the changes were trends that did not reach statistical significance. The availability of a non-pharmacological treatment that improves exercise capacity and quality of life would be a major advance. However, further studies will need to address the question of mortality and morbidity benefits of such intervention.
Atrial Fibrillation: Rhythm or Rate Control?
Authors: Landolina Maurizio , De Ferrari Gaetano M. , Cantù Francesco , Petracci Barbara , Tavazzi Luigi
Published: November 2003

Atrial fibrillation is the most common sustained cardiac arrhythmia. Its prevalence increases with age, reaching 5% among subjects over 65 years of age. Recently, evaluation of the best therapeutic approach to patients with atrial fibrillation has been the object of two multicenter clinical trials that have compared a strategy of rhythm control and one of rate control. The Atrial Fibrillation Follow-up Investigation of Rhythm Management trial enrolled a total of 4,060 patients with a mean age of 69.7 years. After a mean follow-up of 5 years, total mortality was 24% in the rhythm control group and 21% in the rate control group, leading to a hazard ratio of 1.15 (p = 0.08). Similar results were found in the smaller Rate Control versus Electrical Cardioversion for Persistent Atrial Fibrillation study. The two studies clearly indicate that rate control is not inferior to rhythm control in the general population of patients with atrial fibrillation and that the restoration of sinus rhythm should not be pursued aggressively. The data also suggest the opportunity for adequate anticoagulation among patients assigned to the rhythm control strategy. The characteristics of the patients enrolled as well as the analysis of subgroups suggest that the preference toward a rate control strategy may not apply to young patients who are moderately or highly symptomatic for atrial fibrillation, nor to patients with heart failure, in whom the arrhythmia may contribute to the progression of the disease. For these two classes of patients, rhythm control may still be an attractive option.
Symbole als Ausdruck der therapeutischen Beziehung
Authors: Kleeberg Alexandra , Schreiber Sieglinde , Schwinger Thomas
Published: November 2003

Von Patientinnen und Therapeutinnen wurden Beurteilungen von jungianisch orientierten Psychotherapiestunden und ausserdem Symbole für einen Aspekt des Schattens erhoben. Zwischen der Zufriedenheit mit der Therapie und Merkmalen einer offenen therapeutischen Beziehung bestehen enge Zusammenhänge. In zwei weiteren Untersuchungen wurden die Schattensymbole der Patientinnen und Therapeutinnen mit Methoden und Begriffen anderer als jungianischer Theorien untersucht: Aussenstehende hatten die Symbole nach Ähnlichkeit und interpersonalem Stil im Sinne der Sullivanschule einzuschätzen. Die resultierenden Ähnlichkeitsgruppierungen zeigen den interpersonalen Stil als Urteilsdimensionen und entsprechen Unterschieden im Erleben der Beteiligten. Die Gruppierungen der Therapeutinnensymbole stimmen z.T. mit dem Modell der therapeutischen Beziehung von Müller überein. Vermeidung von Dominanz seitens Therapeutinnen scheint mit Vermeidung von Schwäche seitens Patientinnen einherzugehen.
Illusionsbildung als Abwehr und Bewältigung von Ohnmachtserfahrung1
Authors: Metzner Elke , Lesmeister Roman
Published: November 2003

Leider besteht für diesen Artikel keine Zusammenfassung. Als Einstieg stellen wir den Textanfang zur Verfügung. Was verstehen wir unter «Illusion»? Etymologisch bedeutet es «eingebildete Wirklichkeit, Wunschbild, Selbsttäuschung. Es wird aus dem Lateinischen «illusio»: die Verspottung, Täuschung, eitle Vorstellung, entlehnt; il-ludere meint assimiliert in-ludere: hineinspielen, sein Spiel treiben, verspotten, täuschen. Das Stammwort ludus verweist auf Kurzweil, Scherz, Spass Spiel, Schauspiel, Schule, auf etwas nicht Notwendiges, vielmehr auf Möglichkeiten, Freiräume und Freizeiten im realen und übertragenen Sinne.
Mother-Infant Interactions in Slow Lorises (Nycticebus bengalensis) and Pygmy Lorises (Nycticebus pygmaeus)
Authors: Fitch-Snyder H. , Ehrlich A.
Published: November 2003

The study had three purposes: (1) to obtain information about mother-infant interactions in a rarely studied nocturnal prosimian, the pygmy loris (Nycticebus pygmaeus); (2) to compare pygmy lorises with a closely related and better-studied nocturnal prosimian, the Bengal slow loris (Nycticebus bengalensis); and (3) to determine how the presence of a second offspring affected mother-infant interactions in pygmy lorises. Three Bengal slow loris mothers and 3 pygmy loris mothers served as subjects, along with their 10 offspring (4 Bengal slow loris singletons, 2 pygmy loris singletons and 2 sets of pygmy loris twins). Observations were carried out in a zoo research facility for the first 24 weeks of the infants’ lives. Although the two species differ in size and reproductive patterns, mother-infant interactions were similar. The primary modes of infant and adult contact were ventral and passive contact, respectively. Mothers parked their infants from the first week, and infants followed from the second week. Mothers displayed little protection or rejection, and there was little aggression. Infants solicited play and social grooming from their mothers. Pygmy loris mothers engaged in social grooming and play with their infants more frequently and for longer periods if the infant was a singleton rather than a twin.
Species-Typical Patterns of Infant Contact, Sleeping Site Use and Social Cohesion among Nocturnal Primates in Africa
Authors: Bearder Simon K. , Ambrose Lesley , Harcourt Caroline , Honess Paul , Perkin Andrew , Pimley Elizabeth , Pullen Samantha , Svoboda Nadine
Published: November 2003

This paper provides a checklist and summary of what is currently known of the variation in infant contact, sleeping site preference and aspects of social cohesion in the nocturnal primates of Africa. Genera and species are compared, based on previously unpublished field observations and a review of the literature. There is a clear pattern of similarity between the species within each genus and distinct differences between genera. Species in the same genus tend to be ecologically equivalent and replace each other allopatrically, whereas species in different genera are more likely to be sympatric, with up to 6 species living together. Maximum sympatry within genera is found in Otolemur and Galagoİdes, where species are ecologically divergent. This may reflect an ancient origin of species within these genera or suggest that further taxonomic revision is required at the generic level. Some data are recorded for the first time for species that have only recently been separated (cryptic species), but some taxa remain very poorly known. It is concluded that field studies are still at an elementary stage and further research with radio tracking is urgently needed in the face of rapidly declining habitats.
Glutamate Receptors Coupled to Nitric Oxide Synthesis in Embryonic Retina
Authors: López-Colomé Ana María , López Edith
Published: November 2003

Existing evidence suggests a role for nitric oxide (NO) in the establishment of stable synaptic connections during the embryonic development of the central nervous system. In the visual system, the participation of NO in programmed cell death, the natural elimination of photoreceptors and the modulation of photoreceptor ion channels has been documented. In the present work, the effect of ionotropic and metabotropic glutamate receptor (GluR) agonists on NO synthesis in the chick retina was studied at embryonic day (ED) 14, in which active synaptogenesis takes place, and compared with that in the mature tissue. We showed that at ED 14, N-methyl-D-aspartate, kainate and trans-(1S,3R)-1-amino-1,3-cyclopentanedicarboxylate stimulate NO formation at low concentrations, whereas high concentrations of the drugs inhibit NO synthesis. The results suggest the participation of GluR-induced NO synthesis in differentiation and synaptogenesis, and demonstrate a negative feedback of GluR stimulation on NO synthesis by nonphysiological glutamate concentrations, which could be relevant to neuronal protection from glutamate-induced toxicity in the retina during a critical period of embryonic development.
Expression of Glutamate Transporters in the Medial and Lateral Vestibular Nuclei during Rat Postnatal Development
Authors: Devau Gina , Plachez Céline , Puyal Julien , Pierrot Nathalie , Ventéo Stéphanie , Raymond Jacqueline
Published: November 2003

The postnatal developmental expression and the distribution of the glutamate transporters (GLAST, GLT-1 and EAAC1) were analyzed in rat vestibular nuclei (VN), at birth and during the following 4 weeks. Analyses were performed using reverse transcriptase-polymerase chain reaction and immunoblotting of GLAST, GLT-1 and EAAC1 mRNA and protein during the postnatal development of the VN neurons and their afferent connections. We also studied the distribution of each glutamate transporter in the medial and lateral VN by use of immunocytochemistry and confocal microscopy. GLAST, GLT-1 and EAAC1 mRNA and protein were present in the VN at each developmental stage. GLAST was highly expressed mainly in glia from birth to the adult stage, its distribution pattern was heterogeneous depending on the region of the medial and lateral VN. GLT-1 expression increased dramatically during the second and third postnatal weeks. At least during the first postnatal week, GLT-1 was expressed in the soma of neurons. EAAC1 was detected in neurons and decreased from the third week. These temporal and regional patterns of GLAST, GLT-1 and EAAC1 suggest that they play different roles in the maturation of glutamatergic synaptic transmission in the medial and lateral VN during postnatal development.
Modulatory Effect of Cyclooxygenase Inhibitors on Sildenafil-Induced Antinociception
Authors: Patil Chandrashekhar S. , Jain Naveen K. , Singh Amarjit , Kulkarni Shrinivas K.
Published: November 2003

Peripheral activation of the NO-cGMP pathway has been implicated in various nociceptive conditions. The antinociceptive effect of the PDE-5 inhibitor, sildenafil, alone or in combination with cyclooxygenase inhibitor diclofenac and nimesulide, was assessed in the different animal models of peripheral nociception. In the present study we investigated the possible interaction between cyclooxygenase and NO-cGMP pathway in writhing assay and carrageenan-induced hyperalgesia in mice and rats, respectively. Sildenafil [1–2 mg/kg, i.p. or 50–100 µg/paw, intraplantar (i.pl.)], nimesulide (1–2 mg/kg, i.p. or 25–50 µg/paw, i.pl.) and diclofenac (1–2 mg/kg, i.p. or 25–50 µg/paw, i.pl.) exhibited an antinociceptive effect in both the models. When ineffective doses of sildenafil (0.5 mg/kg, i.p and 25 µg/paw, i.pl.) were co-administered with ineffective doses of nimesulide (0.5 mg/kg, i.p. and 10 µg/paw, i.pl.) and diclofenac (0.5 mg/kg, i.p. and 10 µg/paw, i.pl.), there was a significant increase in the antinociceptive effect in both the models of peripheral nociception. Further, the potentiation of the effect was blocked by L-NAME (20 mg/kg, i.p., 100 µg/paw, i.pl.), a non-selective NOS inhibitor and methylene blue (1 mg/kg, i.p.), a guanylate cyclase inhibitor. L-NAME or methylene blue itself had little or no effect on both the models of hyperalgesia. These results suggest that cyclooxygenase, NO and cGMP are relevant in the combination-induced antinociception. In conclusion, sildenafil induced antinociception, and its potentiation of the effect of the cyclooxygenase inhibitors nimesulide and diclofenac was probably mediated through the activation of the NO-cGMP pathway and inhibition of cyclic GMP degradation.
Chronic Nephropathies: Individual Risk for Progression to End-Stage Renal Failure as Predicted by an Integrated Probabilistic Model
Authors: Dimitrov Borislav D. , Ruggenenti Piero , Stefanov Rumen , Perna Annalisa , Remuzzi Giuseppe
Published: November 2003

Background/Aims: To predict risk of end-stage renal disease (ESRD) in individual patients with chronic nephropathy. Methods: Sequential use of univariate analyses and Cox regression to identify risk factors, artificial neural network to quantify their relative importance and Bayesian analysis to address uncertainty of relationships and incorporate ESRD prevalence information in 344 patients with chronic nephropathy enrolled in the Ramipril Efficacy In Nephropathy study. Results: Serum creatinine (SC), 24-hour urinary protein excretion (UPE) and calcium-phosphorus (Ca*P) product were, in this order, the strongest time-adjusted ESRD predictors. Individual risk of ESRD ranged from near zero when SC and UPE were <1.66 mg/dl and <3 g/24 h, to 69% when SC, UPE and Ca*P were ≧2.41 mg/dl, ≧3 g/24 h and ≧32.64 mg2/dl2, respectively. Receiver operating characteristic curves showed that within lowest, middle and highest tertiles of basal SC (0.90–1.65, 1.66–2.40 and 2.41–6.30 mg/dl, respectively) the model accurately predicted ESRD (AUC = 0.80, 0.72 and 0.65; p = 0.0003, 0.0001 and 0.0022, respectively), quality of life or treatment costs. Conclusion: Integrated use of regression analysis and probabilistic models allows computation of individual risk of progression to ESRD and related utilities. This may help in optimizing care and costs in nephrology and other medical areas and designing trials in high-risk patients.
Plasma Levels of Proadrenomedullin N-Terminal 20 Peptide and Adrenomedullin in Patients Undergoing Hemodialysis
Authors: Tokura Takeshi , Kinoshita Hiroshi , Fujimoto Shouichi , Kitamura Kazuo , Eto Tanenao
Published: November 2003

Background: Proadrenomedullin N-terminal 20 peptide (PAMP) is a novel hypotensive peptide present in the precursor of adrenomedullin (AM), a vasodilative and natriuretic peptide. However, the profile of PAMP in hemodialyzed (HD) patients has not been determined. Methods: We measured plasma levels of PAMP, total AM (tAM) and a mature form of AM (mAM, the biologically active form) in HD patients (n = 31) and in normal controls (n = 21). Results: Plasma concentrations of PAMP before HD were significantly higher than those in controls (4.02 ± 0.24 vs. 1.64 ± 0.12 fmol/ml, p < 0.001) and decreased to the control level after HD (2.17 ± 0.18 vs. 1.64 ± 0.12 fmol/ml; NS). The plasma PAMP level before HD significantly correlated with weight gain during HD sessions (r = 0.41, p < 0.05), but not with predialysis blood pressure. The concentrations of mAM before and after HD were significantly higher than those in controls. The plasma mAM level before HD significantly correlated with weight gain during HD sessions, but not with predialysis blood pressure. The plasma level of PAMP did not correlate with that of mAM in HD patients. Conclusion: PAMP and AM may be involved in the regulation of blood volume in patients undergoing HD.
Detection of Prepro-ET-1 mRNA in Normal Rat Kidney by in situ RT-PCR
Authors: Moridaira Kazuaki , Nodera Makoto , Sato Gen , Yanagisawa Hiroyuki
Published: November 2003

Background: Available evidence has shown that endothelin-1 (ET-1) acts in an autocrine/paracrine fashion rather than as a hormone or cytokine. Therefore, the analysis of local ET-1 production is a crucial step toward understanding its physiological and pathophysiological importance. In this study, in situ RT-PCR was utilized to detect tubular expression of prepro-ET-1 mRNA in normal rat kidney. Methods: Kidneys were taken from normal Sprague-Dawley rats weighing approximately 200 g. In situ RT-PCR was carried out using the preparations embedded in paraffin and cut at a thickness of 8 µm. Furthermore, we tried semiquantitation of the prepro-ET-1 mRNA expression along different nephron segments by densitometric analysis. Results: Prepro-ET-1 mRNA expression was detected in all tubular segments of the kidney from normal rats. Densitometric analysis demonstrated its highest expression in cortical collecting duct (CCD) and outer medullary collecting duct (OMCD). The expression was the lowest in thin descending limb of Henle’s loop (TDL). Conclusion: This study showed that all tubular segments have the ability to synthesize ET-1 in rat kidney. It would be worth evaluating the levels prepro-ET-1 mRNA expression in various diseases by in situ RT-PCR to understand its pathophysiological role in such settings.
Proteomic Identification of a Large Complement of Rat Urinary Proteins
Authors: Thongboonkerd Visith , Klein Jon B. , Arthur John M.
Published: November 2003

The characterization of urinary proteins is an important tool to identify disease-related biomarkers and to better understand renal physiology. Expression of urinary proteins has been previously studied by Western blotting and other immunological methods. The scope of such studies, however, is limited to previously identified proteins for which specific antibodies are existed. We used proteomic analysis to identify proteins and to construct a proteome map for Sprague-Dawley (SD) rat urine isolated by ultracentrifugation. Urinary proteins were separated by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and visualized by silver staining. Proteins were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), followed by peptide mass fingerprinting using the NCBI protein database. A total of 350 protein spots were visualized. From 250 excised spots, 111 protein components were identified including transporters, transport regulators, chaperones, enzymes, signaling proteins, cytoskeletal proteins, pheromone-binding proteins, receptors, and novel gene products. The presence of a number of these identified proteins was unexpected and had not previously been identified in the urine. 2-D Western blot analyses for randomly selected proteins (ezrin, HSP70, β- and γ-actin, Rho-GDI, and l-myc) clearly confirmed the proteomic identification. Several potential posttranslational modifications were predicted by bioinformatic analyses. These data indicate that a large complement of expected and unexpected urinary proteins can be simultaneously studied by proteomic analysis. This approach may lead to better understanding of renal physiology and pathophysiology, and to biomarker discovery.
Transforming Growth Factor-β1 Induces Vascular Endothelial Growth Factor Expression in Murine Proximal Tubular Epithelial Cells
Authors: Kitamura Shinji , Maeshima Yohei , Sugaya Takeshi , Sugiyama Hitoshi , Yamasaki Yasushi , Makino Hirofumi
Published: November 2003

Vascular endothelial growth factor (VEGF) is a potent endothelial cell mitogen that promotes angiogenesis, vasculogenesis, and increases vascular permeability. VEGF is expressed in renal tubular epithelial cells and urinary VEGF excretion is increased in various glomerular disorders. However, the mechanisms underlying expression of VEGF in renal tubular epithelial cells have not been fully elucidated. In the present study, we attempted to define a predominant regulator of VEGF expression using a cultured murine renal proximal tubular epithelial cell line (mProx24). VEGF protein concentration in the culture supernatant was measured by sandwich enzyme-linked immunosorbent assay. mProx24 constitutively produced VEGF at low level. Major isoforms expressed in this cell line were VEGF164 and VEGF120 determined by reverse transcription-polymerase chain reaction method. Among various stimuli including angiotensin II, transforming growth factor-β1 (TGF-β1), lipopolysaccharides, interleukin-1β, interleukin-10 and interferon-γ, only TGF-β1 significantly increased the level of VEGF protein at 24 h in a dose-dependent manner. The steady-state mRNA level of VEGF was dose dependently increased by TGF-β1 detected by Northern blotting. Treatment with neutralizing anti-TGF-β1 antibody abolished TGF-β1-induced VEGF expression by 70%. Inhibitors of protein kinase C (PKC), Ro-31-8220 and staurosporin, significantly suppressed TGF-β1-induced VEGF protein expression. These results demonstrate the role of TGF-β1 on the expression of VEGF in proximal tubular epithelial cells mediated potentially via PKC pathway. This regulatory mechanism may be associated with the progression of tubulointerstitial lesions in renal disorders.
Acute Bile Duct Ligation Ameliorates Ischemic Renal Failure
Authors: Jeyarajah D. Rohan , Kielar Mariusz L. , Zhou Xin J. , Zhang Ying , Lu Christopher Y.
Published: November 2003

Background: Biliary obstruction affects the renal response to ischemia and also elicits a hepatic cytokine response. Using a murine model, we now test the hypothesis that these hepatic cytokines help determine the outcome of ischemic acute renal failure. Methods: C3H/HEN mice were subjected to bile duct ligation 24 h (ABDL) or 7 days (CBDL) prior to induction of acute ischemic renal failure (ARF). Serum creatinine (Scr), cytokine mRNA abundance, and renal histology were studied 24 h after renal ischemia. Results: ABDL prior to ARF resulted in amelioration of renal injury (Scr 0.7 ± 0.1 mg/dl compared to 2.5 ± 0.1 mg/dl in sham/ARF group, (mean ± SE, n = 11/group). CBDL exacerbated renal injury. Increased hepatic mRNA for interleukin-10 (IL10) and interleukin-1 receptor antagonist (IL1RA) was detected in the ABDL/ARF group but not in the CBDL/ARF group. These data suggest that hepatic production of IL10 and IL1RA in response to ABDL ameliorates ischemic ARF, an effect that is lost after several days of BDL. Conclusion: Our data support the concept that hepatic cytokines modulate renal injury. This adds a new dimension in our understanding of renal injury in the setting of hepatic disease.
Haplotype Tagging Single Nucleotide Polymorphisms and Association Studies
Authors: Thompson Deborah , Stram Dan , Goldgar David , Witte John S.
Published: November 2003

Objectives: Discrete blocks of low haplotype diversity exist within the human genome. The non-redundant subset of ‘haplotype tagging’ single nucleotide polymorphisms (htSNPs) in such blocks can distinguish a majority of the haplotypes. Several approaches have been proposed to determine htSNPs, ranging from visual inspection to formal analytic procedures. Optimal htSNPs can be estimated using a small subgroup of an association study population that have been genotyped for a dense SNP map, and it is just these htSNPs that are genotyped in the remainder of the samples. We investigated by simulation how the size of the subsample affects the power of association studies, and what type of subjects it should include. Methods: We used the program tagSNPs [Stram et al., Hum Hered 2003;55:27–36], which selects htSNPs to minimize the uncertainty in predicting common haplotypes for individuals with unphased genotype data. Results: On average, 27% of the SNPs were designated as htSNPs. Genotyping as few as 25 unphased individuals to select the htSNPs did not appear to reduce the power of an association study, as compared with using all SNPs. For the disease models considered, selecting htSNPs based on cases, controls, or a mixture of both gave similar results. Conclusions: These results suggest that the genotyping effort in an association study can be substantially reduced with little loss of power by identifying htSNPs in a small subsample of individuals.
Reactivation of the Mitosis-Promoting Factor in Postmitotic Cardiomyocytes
Authors: Dätwyler Daniel A. , Magyar Josef P. , Weikert Christian , Wightman Lionel , Wagner Ernst , Eppenberger Hans M.
Published: November 2003

Cardiomyocytes cease to divide shortly after birth and an irreversible cell cycle arrest is evident accompanied by the downregulation of cyclin-dependent kinase activities. To get a better understanding of the cardiac cell cycle and its regulation, the effect of functional recovery of the mitosis-promoting factor (MPF) consisting of cyclin B1 and the cyclin-dependent kinase Cdc2 was assessed in primary cultures of postmitotic ventricular adult rat cardiomyocytes (ARC). Gene transfer into ARC was achieved using the adenovirus-enhanced transferrinfection system that was characterized by the absence of cytotoxic events. Simultaneous ectopic expression of wild-type versions of cyclin B1 and Cdc2 was sufficient to induce MPF activity. Reestablished MPF resulted in a mitotic phenotype, marked by an abnormal condensation of the nuclei, histone H3 phosphorylation and variable degree of decay of the contractile apparatus. Although a complete cell division was not observed, the results provided conclusive evidence that cell cycle-related events in postmitotic cardiomyocytes could be triggered by genetic intervention downstream of the G1/S checkpoint. This will be of importance to design novel strategies to overcome the proliferation arrest in adult cardiomyocytes.
The Salt Paradox of the Early Diabetic Kidney Is Independent of Renal Innervation
Authors: Birk C. , Richter K. , Huang D.Y. , Piesch C. , Luippold G. , Vallon V.
Published: November 2003

Glomerular filtration rate (GFR) is inversely and thus paradoxically related to dietary NaCl intake in rats and patients with early type 1 diabetes mellitus (DM). Enhanced sensitivity of proximal reabsorption to NaCl diet inducing secondary adaptations in GFR through actions of tubuloglomerular feedback causes this salt paradox. We studied the role of renal nerves for the salt paradox in rats with streptozotocin (STZ)-induced DM since a regulatory influence of renal nerves on proximal reabsorption is well established. The left kidney (LK) was denervated before induction of STZ-DM. Subsequently, the normal diet was continued or a low NaCl diet was initiated and 1 week later animals were prepared for clearance experiments under anesthesia including ureter catheterization to measure GFR for each kidney. In diabetic rats, the right innervated as well as the left denervated kidney showed higher values for GFR and kidney weight in animals on a low versus a normal NaCl diet indicating that the salt paradox occurs independent of renal innervation. In addition, evidence is provided that the renal nerves of non-diabetic rats do not contribute to renal Na+ retention during dietary NaCl restriction but modulate renal hemodynamics and kidney weight under these conditions.
Muscle activation and strain patterns of the m. hyohyoideus of carp (Cyprinus carpio L.) during opercular movements
Authors: Spierts Igor , Niessen Martijn , van Leeuwen Johan
Published: November 2003

We investigated the function of the m. hyohyoideus superior (MHS) and inferior (MHI) in the head of three carp (Cyprinus carpio L., 29.7 ± 2.1 cm FL ) during three movements (normal breathing, stressed movements and food uptake). Both muscle parts are located ventrally at the inner side of the operculum and branchiostegal rays and consist of red (mainly in MHI) and white (mainly in MHS) fibres. Contrasting views exist about the functional role of these muscles during ventilation and food uptake. Therefore, we analysed muscle activities of the MHS and MHI using electromyography (EMG) and measured the strain pattern of the MHS using sonomicrometry. Carp were also filmed from a ventral viewpoint using high-speed video at 250 frames s-1. EMG and sonomicrometry data showed an increase in muscle strain amplitudes, cycle frequency and (relative) stimulus duration while stimulus on- and off-times occurred earlier in the strain cycle from normal breathing to stressed movements to food uptake. The MHS and MHI were always simultaneously active. We concluded that: 1) the MHI is not responsible for high frequency movements (i.e. stressed movements and food uptake); 2) both muscle parts assist in the onset of opercular closing, and 3) the MHS and MHI do not act as antagonists in carp.
Oxygen profile in zebra fish embryo (Danio rerio) elucidated by theory and experiment
Authors: Kranenbarg Sander , van den Boogaart Jos , van Leeuwen Johan
Published: November 2003

We present a numerical-experimental diffusion study in which we elucidate the spatial oxygen profile around and inside a zebra fish embryo in the pre-circulation stage (24-28 hpf). Lowest oxygen partial pressures are found in the head with a gradient of posteriorly increasing pressure along the midline of the embryo. Furthermore, this study shows the yolk mass to have a relatively high oxygen permeability as compared to the surrounding medium and the respiring tissue. The oxygen permeability of the respiring tissue in this stage is close to that of water. Knowledge of the details of the oxygen distribution are important for an understanding of vasculogenesis and angiogenesis, since oxygen levels influence the expression of endothelial growth factors.
Reproductive characteristics of a lowland population of an alpine lizard: Lacerta monticola (Squamata, Lacertidae) in north-west Spain
Authors: Rúa Marta , Galán Pedro
Published: November 2003

We studied the reproductive ecology of a population of the lacertid lizard Lacerta monticola at a lowland location in A Coruña (NW Spain) from 1997 to 2002. The timing of the reproductive cycle was examined based on mark-recapture records of individual lizards in the field. The characteristics of the eggs and hatchlings were obtained from clutches laid in the laboratory by pregnant females that were temporarily removed from the study area. Our results indicate that mating took place between late March and July. The smallest female with signs of sexual maturity had a snout-vent length (SVL) of 52.4 mm and the smallest male was 50.7 mm. Sexual maturity was attained at the age of 2 years by 41% of the individuals, while the remaining 59% of the lizards matured at the age of 3 years. The laying period occurred between June and the beginning of August considering all years. About 61% of the reproductive females produced a single clutch annually, while 39% of the females produced two clutches per year. Females that produced two clutches were generally larger (average SVL = 70.9 mm) than those that laid a single annual clutch (average SVL = 62.6 mm). The mean clutch size was 6.4 eggs (range 4-9). Both clutch size and clutch mass increased significantly with female SVL. The mean egg mass in a clutch decreased significantly with clutch size. Hatching occurred between August and September. Hatching success in the laboratory was 71.7%. The mean SVL was higher in female hatchlings than in males.
Microgeographical distribution of ants (Hymenoptera: Formicidae) in coastal dune grassland and their relation to the soil structure and vegetation
Authors: Bonte  , Dekoninck  , Provoost  , Cosijns  , Hoffmann
Published: November 2003

In this paper, we investigate the microgeographical distribution of ants nests in an intensively grazed dune pasture. A total of seven species were recorded. By the application of a forward multiple logistic regression we were able to determine nesting choice for the three common species Lasius niger, L. psammophilus and Myrmica specioides. The first could be identified as a pioneer species, while the two latter species, which are typical of dry, sandy dune grounds, differ slightly in their nesting preference. The effect of nest building on soil structure was investigated for a mound-building species (Formica cunicularia) and for a non-mound-building species (Lasius psammophilus). Both species significantly decrease the thickness of the organic and water-capturing soil layer, while the mound-building species additionally affects the soil lime content (an increase) and the soil hardness (a decrease). Mound building in dense Calamagrostis vegetation also stimulates the germination of a characteristic and rare plant species, Thymus pulegioides.
Regulated secretion of glycosylated human ferritin from hepatocytes
Authors: Ghosh Sharmistha , Hevi Sarah , Chuck Steven L.
Published: November 2003

Serum ferritin has been used widely in clinical medicine chiefly as an indicator of iron stores and inflammation. Circulating ferritin also can have paracrine effects. Despite the clinical significance of serum ferritin, its secretion remains an enigma. The consensus view is that serum ferritin arises from tissue ferritins— principally ferritin light—which can be glycosylated. Ferritin heavy and light chains are cytosolic proteins that form cages of 24 subunits to store intracellular iron. We show that ferritin light is secreted when its expression is increased in stable, transfected HepG2 cells or adenovirus-infected HepG2 cells. Export occurs through the classical secretory pathway and some chains are N-glycosylated. Ferritins do not need to form cages prior to secretion. Secretion is blocked specifically, effectively, and rapidly by a factor in serum. The timing of this inhibition of ferritin secretion suggests that normally cytosolic ferritin L is targeted to the secretory pathway during translation despite the absence of a conventional signal sequence. Thus, secretion of glycosylated and unglycosylated ferritin is a regulated and not a stochastic process.
Binding of Sodium Dodecyl Sulfate to a Cationic Polymer of High Charge Density
Authors: Lee Jungno , Moroi Yoshikiyo
Published: November 2003

An investigation was made into the binding of sodium dodecyl sulfate (SDS) to a cationic polymer of high charge density, the homopolymer of diallyldimethylammonium chloride (PDADMAC), in 1 mM (1 M = 1 mol dm−3) NaCl solution using a potentiometric titration method utilizing a surfactant-selective electrode at 15, 20, 25, 30, 35, and 45 °C. The concentrations of PDADMAC examined were 100, 200, and 400 ppm. SDS ions bound very cooperatively to the PDADMAC polymer. Variation of the polymer concentration had almost no effect on the binding parameters at the same temperature, while increasing the temperature had a large effect on the binding system at the same polymer concentration. The intrinsic binding constant (K) and the critical aggregation concentration (cac) decreased and then increased with increasing temperature, having minimum values of 17.9 × 10−2 mM−1 and 0.19 × 10−2 mM at 25 °C, respectively. However, the cooperativity parameter (u) and the binding affinity (uK) had a maximum value of 20.0 × 102 and 357 at the same temperature, respectively. The polymer-concentration-independence of the binding parameters for the anionic surfactant (SDS) to the cationic polymer (PDADMAC) corresponds to the binding of a cationic surfactant to an anionic polymer, and the maximum in the binding affinity at 25 °C is quite similar to the binding of a cationic surfactant to an anionic polymer, and also to the micellization of ionic surfactants having a minimum cmc value at 25 °C.
The Potentiometric Effect of As(III) Ion on a Belousov–Zhabotinskii Oscillating Chemical Reaction. Application to the Determination of As(III)
Authors: Ojani Reza , Raoof Jahanbakhsh , Mahdavi Fathemeh
Published: November 2003

A novel analytical method that builds on specific features of non-linear chemical systems far from thermodynamic equilibrium is described. The used oscillating chemical system is the BZ (Belousove–Zhabotinskii) reaction in a non-equilibrium stationary state close to a bifurcation point. The method uses a Pt electrode for monitoring the potential response to a perturbation caused by As(III) ion. A linear response, in which the oscillating amplitude varies versus the logarithm of the As(III) concentration, was found in the range of 1.99 × 10−6–1.27 × 10−4 M. Under optimum conditions, a detection limit of 2 × 10−6 M for As(III) was obtained. The relative standard deviation (%RSD) for As(III) 1.59 × 10−5 M is 7.1 (n = 6).
Hydrogen Generation by Wet Grinding of Quartz Powders and Its Dependence on the pH and Ionic Strength of Liquid Media
Authors: Kameda Jun , Saruwatari Kazuko , Tanaka Hidemi
Published: November 2003

Hydrogen generation was investigated by grinding quartz powder in pH- and ionic strength-controlled liquid media. The effect of ionic strength on hydrogen generation was negligible, while the decrease of generated hydrogen in the acidic pH region (>5.0) was observed. The mechanism of these mechanochemical reactions was discussed.
Role of Hydrogen Bonding in Azobenzene–Urea Assemblies. Structural Evaluations of Multilayers on Solid Substrates
Authors: Seki Takahiro , Fukuchi Takashi , Kobayashi Toru , Ichimura Kunihiro
Published: November 2003

The multilayers of three homologous azobenzene (Az)-containing urea derivatives, having two, one and no hydrogen atom(s) at the terminal nitrogen atom in the urea moiety, and a simple long chain urea (hexadecylurea) were prepared by the Langmuir–Schaefer method. X-ray reflectometry, contact angle measurements of water, and Fourier transform infrared (FTIR) spectroscopy were undertaken to evaluate the layer structure and properties of these multilayered films. Of the four compounds, only the Az amphiphile, having no hydrogen atom at the terminus nitrogen atom, provided a different type of multilayers in terms of the molecular orientation, flexibility of the packing state, and characteristics of the intermolecular hydrogen bonding. The obtained data strongly support the formation of bifurcated hydrogen bonds for compounds having one or two hydrogen atom(s) at the terminus nitrogen of urea. The aspects obtained in this structural study can be exactly correlated with the properties of the Langmuir monolayers floating on water (Seki et al., Langmuir, 18, 5462 (2002).). Based on the X-ray and IR spectroscopic data, plausible models of the packed structure of the urea compounds in the multilayers are proposed.
Selective Reduction of α-Chloroketone to α-Chloroalcohol Using Hydrogen Transfer from Alcohol over Metal Oxide Catalysts
Authors: Gotoh Kunihiro , Kubo Jun , Ueda Wataru , Mori Tohru , Morikawa Yutaka
Published: November 2003

The carbonyl group of 1,3-dichloro-2-propanone was reduced selectively through hydrogen transfer from 2-butanol over MgO, SiO2·Al2O3, Al2O3, and ZrO2. It is suggested that the reaction is promoted by either base or acid site of the catalysts.
Effective Shortening in Length of Glycolipid Nanotubes with High Axial Ratios
Authors: Yang Bo , Kamiya Shoko , Yui Hiroharu , Masuda Mitsutoshi , Shimizu Toshimi
Published: November 2003

A novel glycolipid, N-(11-cis-octadecenoyl)-β-d-glucopyranosylamine self-assembles in water to provide monodispersed and well-defined glycolipid nanotubes (LNTs) with a high-axial-ratio structure. Mechanical stirring of the LNT suspension proved to convert the obtained long LNTs into short ones (<10 μm) in length, depending on the feature of hydrogen bond network in the LNTs.
Facile Chemical Modification of the Poly(l-histidine) for a New pH-Sensitive Polypeptide
Authors: Asayama Shoichiro , Kawakami Hiroyoshi , Nagaoka Shoji
Published: November 2003

We have synthesized the poly(l-histidine) (PLH) with aliphatic primary amino groups for conjugation as a new pH-sensitive polypeptide. The resulting aminated PLH suddenly precipitated out of the aqueous medium above pH 6.0 owing to the deprotonation of imidazole groups. The aminated PLH was successfully conjugated with maltopentaose by reductive amination. The resulting PLH-maltopentaose conjugate improved its water solubility at physiological pH.
Photocatalytic Decomposition of Acetaldehyde under Visible Light Irradiation over La3+ and N Co-doped TiO2
Authors: Sakatani Yoshiaki , Nunoshige Jun , Ando Hiroyuki , Okusako Kensen , Koike Hironobu , Takata Tsuyoshi , Kondo Junko N , Hara Michikazu , Domen Kazunari
Published: November 2003

La3+ and N co-doped TiO2, which contained paramagnetic N species, decomposed acetaldehyde under visible light irradiation. The number of the paramagnetic N species seemed to control the absorption of visible light and the activity.
“Syn-Effect” in the Desilylation Reaction of γ-Silylated Allylic and Vinylic Sulfones
Authors: Guha Samar Kumar , Ukaji Yutaka , Inomata Katsuhiko
Published: November 2003

The desilylation reaction of γ-silylated allylic sulfones was found to proceed through γ-silylated (E)-vinylic sulfones to afford the corresponding allylic sulfones by treatment with DBU and H2O. The Z/E ratio of the resulting allylic sulfones varied according to the γ-substituents of the γ-silylated sulfones. This stereochemical outcome was rationalized by “syn-effect.”