bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactions between zinc chloride and surfactant solutions
Authors: Vold Robert D. , Singh Hakam 
Published: May 2007

AbstractFormation of precipitates or soluble complexes between solutions of zinc chloride and surfactants was investigated by means of pH and conductivity titrations. Precipitates were characterized by chemical analysis and X‐ray diffraction.Triton X‐102 and zinc chloride appear not to react. Sodium dodecyl sulfate likewise appears non‐reactive, but on addition of alkali a basic salt is formed at a pH between 7.9 and 8.5 which, however, does not precipitate if the concentration of sodium dodecyl sulfate is above the critical micelle concentration. The precipitate has a marked destabilizing action on oil‐in‐water emulsions. With the sodium salt of Empol 1022 the normal zinc salt precipitates on addition of the stoichiometric amount of zinc chloride.Tamol 731 is neutralized in two steps by hydrochloric acid, the pH at the two endpoints being 7.0 and 3.3. It apparently forms a soluble complex with zinc ion which is not precipitated even in alkaline solutions.
Herbicide 2,4‐dichlorophenoxyacetic acid (2,4‐D)‐induced cytogenetic damage in human lymphocytes in vitro in presence of erythrocytes
Authors: Soloneski Sonia , González Norma V. , Reigosa Miguel A. , Larramendy Marcelo L. 
Published: May 2007

AbstractThe genotoxic effects of 2,4‐D and its commercial derivative 2,4‐D DMA were studied by measuring sister chromatid exchange (SCE), cell‐cycle progression and mitotic index in human whole blood (WBC) and plasma leukocyte cultures (PLC). Concentrations of 10, 25, 50 and 100 μg herbicide/ml were used during 72 h. In WBC, a significant increase in SCE frequency was observed within the 10–50 μg 2,4‐D/ml and 25–100 μg 2,4‐D DMA/ml dose range. Contrarily, in PLC, none of the concentrations employed affected the SCEs frequency. A significant delay in cell proliferation was observed in WBC after treatments with 25 and 50 μg 2,4‐D/ml and 50 and 100 μg 2,4‐D DMA/ml. In PLC, only 100.0 μg 2,4‐D/ml altered cell‐cycle progression. For both chemicals, a progressive dose‐related inhibition of mitotic activity was observed. The results demonstrated that the presence of erythrocytes in the culture system modulated the DNA and cellular damage inflicted by 2,4‐D and 2,4‐D DMA into human lymphocytes in vitro as well as both 2,4‐D and 2,4‐D DMA were more potent genotoxic agents in the presence of human red cells.
Epigallocatechin gallate‐induced apoptosis does not affect adipocyte conversion of preadipocytes
Authors: Morikawa Keiko , Ikeda Chiharu , Nonaka Mitsuko , Pei Sumi , Mochizuki Misa , Mori Asuka , Yamada Sonoko 
Published: May 2007

AbstractIn the present study, we examined the effect of epigallocatechin gallate (EGCG) on the growth and differentiation of human preadipocyte cells, AML‐I. EGCG exhibited cytotoxic activity on AML‐I cells, accompanied by the appearance of characteristics of apoptosis by Annexin V—FITC staining method. Among apoptosis‐related proteins examined, loss of NF‐κB and p‐Akt, and accumulation of Bad were displayed in EGCG‐treated cells by Western blot analysis. Among 6 structure‐related catechins including catechin (C), epicatechin (EC), catechin gallate (CG), epigallocatechin (EGC), epicatechin gallate (ECG) and EGCG, the catechins containing galloyl moiety exhibited apoptotic capacity. Interestingly, exposure of AML‐I to EGCG increased the amounts of cytoplasmic lipid droplets as well as the expression of fatty acid synthase and peroxisome proliferator activated receptor‐γ proteins. Our results suggest that EGCG induces growth arrest and apoptosis, but does not affect adipocyte conversion of preadipocytes.
Prediction of GPCR-G Protein Coupling Specificity Using Features of Sequences and Biological Functions
Authors: Ono Toshihide , Hishigaki Haretsugu 
Published: May 2007

Abstract
Understanding the coupling specificity between G protein-coupled receptors (GPCRs) and specific classes of G proteins is important for further elucidation of receptor functions within a cell. Increasing information on GPCR sequences and the G protein family would facilitate prediction of the coupling properties of GPCRs. In this study, we describe a novel approach for predicting the coupling specificity between GPCRs and G proteins. This method uses not only GPCR sequences but also the functional knowledge generated by natural language processing, and can achieve 92.2% prediction accuracy by using the C4.5 algorithm. Furthermore, rules related to GPCR-G protein coupling are generated. The combination of sequence analysis and text mining improves the prediction accuracy for GPCR-G protein coupling specificity, and also provides clues for understanding GPCR signaling.
VGIchan: Prediction and Classification of Voltage-Gated Ion Channels
Authors: Saha Sudipto , Zack Jyoti , Singh Balvinder , Raghava G.P.S. 
Published: May 2007

Abstract
This study describes methods for predicting and classifying voltage-gated ion channels. Firstly, a standard support vector machine (SVM) method was developed for predicting ion channels by using amino acid composition and dipeptide composition, with an accuracy of 82.89% and 85.56%, respectively. The accuracy of this SVM method was improved from 85.56% to 89.11% when combined with PSI-BLAST similarity search. Then we developed an SVM method for classifying ion channels (potassium, sodium, calcium, and chloride) by using dipeptide composition and achieved an overall accuracy of 96.89%. We further achieved a classification accuracy of 97.78% by using a hybrid method that combines dipeptide-based SVM and hidden Markov model methods. A web server VGIchan has been developed for predicting and classifying voltage-gated ion channels using the above approaches. VGIchan is freely available at www.imtech.res.in/raghava/vgichan/.
Associations between postprandial insulin and blood glucose responses, appetite sensations and energy intake in normal weight and overweight individuals: a meta-analysis of test meal studies
Authors: Flint Anne , Gregersen Nikolaj T. , Gluud Lise L. , Møller Bente K. , Raben Anne , Tetens Inge , Verdich Camilla , Astrup Arne 
Published: May 2007

It is unclear whether postprandial blood glucose or insulin exerts a regulatory function in short-term appetite regulation in humans. The aim of this study was to investigate, by use of meta-analysis, the role of blood glucose and insulin in short-term appetite sensation and energy intake (EI) in normal weight and overweight participants. Data from seven test meal studies were used, including 136 healthy participants (ALL) (92 normal weight (NW) and 44 overweight or obese (OW)). All meals were served as breakfasts after an overnight fast, and appetite sensations and blood samples were obtained frequently in the postprandial period. Finally, an ad libitum lunch was served. Data were analysed by fixed effects study level (SL) meta-regression analysis and individual participant data (IPD) regression analysis, using STATA software. In SL analysis, postprandial insulin response was associated with decreased hunger in ALL, NW and OW (P < 0·019), and with increased satiety in NW (P = 0·004) and lower subsequent EI in OW (P = 0·022). Multivariate IPD analysis showed similar associations, but only in NW for hunger, satiety and EI (P < 0·028), and in ALL for EI (P = 0·016). The only association involving blood glucose was the multivariate IPD analysis showing an inverse association between blood glucose and EI in ALL (P = 0·032). Our results suggest that insulin, but not glucose, is associated with short-term appetite regulation in healthy participants, but the relationship is disrupted in the overweight and obese. We conclude that the postprandial insulin response may be an important satiety signal, and that central nervous system insulin resistance in overweight might explain the blunted effect on appetite.
Dead Bodies in Nigerian Jurisprudence
Authors: Nwabueze Remigius N 
Published: May 2007

AbstractRecent events and a few judicial decisions in Nigeria show the need for a serious analytical engagement with the law relating to dead bodies. Topical issues from these cases focus on jurisdiction, the right to control the disposition of remains, and remedies available for the infringement of a burial right. While the meaning and content of sepulchral rights remain the same in Nigeria as in many industrialized nations, its prioritization is markedly different. In contrast to the highly individualized nature of burial rights in many Western legal systems, the control of sepulchral right in Nigeria is familial in character. In some circumstances, however, recourse may be had to statutory provisions that import English priority rules. While a range of remedies is available for an interference with a burial right, injunctions and declarations are the most sought after by Nigerian litigants. An expedited hearing is preferable to an interlocutory order of injunction.
The Precarious Place of Labour Rights and Movements in Nigeria's Dual Economic and Political Transition, 1999–2005
Authors: Chinedu Okafor Obiora 
Published: May 2007

AbstractCaught between pressure from dominant global economic actors (such as the International Monetary Fund (IMF), the World Bank (WB), and certain states) to implement painful socio-economic reform measures, and pressure from significant numbers of their own peoples to reject these IMF/WB-style prescriptions, formally democratic “third world” governments often yield to the demands of the former to push through such reforms, sometimes at great social cost. This article utilizes a contemporary Nigerian case study to illustrate this point and to show how the curtailment of labour rights and the weakening of labour movements have formed an important part of the economic strategy of many such governments. This anti-labour rights/movements strategy is an attempt by governments to deal with the human rights contradictions that are often generated when third world countries attempt dual political and economic transitions. The article argues that the deployment of an anti-labour strategy is grounded in a new kind of “full belly thesis” that prioritizes a particular IMF/WB-friendly vision of economic development over certain kinds of political (especially labour) rights. The powerful global economic actors, who would otherwise advocate the observance of all human rights, have nevertheless found this thesis more acceptable than its earlier iteration, which was grounded in a far less IMF/WB-friendly economic vision.
The Use of Exclusions for Corruption in Developing Country Procurement: The Case of South Africa
Authors: Williams Sope 
Published: May 2007

AbstractThe South African public procurement system is regulated by a constitutional framework and legislation applicable to all tiers of government. An interesting feature of the system is that suppliers may be excluded from government contracts for breaches of procurement or anti-corruption legislation. This article critically examines corruption-related exclusions. It is suggested that there is likely to be a number of problems with the implementation of these exclusions. First, it is not clear how effective they will be in meeting the government's anti-corruption policy. Secondly, in respect of the exclusions imposed through a non-judicial process, there are no guidelines to ensure procedural safeguards, and furthermore, these exclusions may lead to delays and costs in the procurement process – especially when it comes to deciding whether persons or firms related to an excluded firm ought to be excluded. Thirdly, there are issues regarding proportionality of the measures. Fourthly, it may be difficult to maintain a consistent approach in deciding whether to exclude under the non-judicial exclusions. In view of these, for the regime to be effective, the South African government must be prepared to bear the attendant financial and procedural burden.
What proportion of patients referred to an otolaryngology vertigo clinic have an otological cause for their symptoms?
Authors: Arya A K , Nunez D A 
Published: May 2007

AbstractBackground:Dizziness is a common and often complex complaint. Between nine and 13 per cent of patients seen in general practice are referred to a variety of specialist clinics. The diagnoses and outcomes of these referrals are seldom reported.Aims:To determine the proportion of patients referred to an otology led vertigo clinic in whom an otological cause for vertigo could be identified.Design of study:Prospective cohort study of consecutive new clinic attendees over one year.Setting and methods:Otology led vertigo clinic in an urban teaching hospital in England. Patients' details including age, sex, referring clinician, investigations, diagnoses, treatment and final outcome were recorded in an anonymised database.Results:91 new patients, 31 men and 60 women with a mean age of 52.6 years (range 16–81) were seen. General practitioners referred 87 per cent of the patients. Twenty-seven patients underwent further investigations including imaging, electronystagmography and other audiological tests. A labyrinthine disorder accounted for 50 per cent of the diagnoses. Ménière's disease or a variant was diagnosed in 20 patients (21 per cent). Fifty-six patients (61 per cent) reported resolution of or improvement in their symptoms. Thirty-one patients (34 per cent) were asymptomatic and free of abnormal findings on initial attendance and were discharged from hospital care.Conclusions:Forty-six patients (50.6 per cent, 95 per cent confidence interval, 40.4–60.6 per cent) had vertigo due to an otological disorder. The selection of an otolaryngology based vertigo clinic by the general practitioner for initial referral seems appropriate.
A Commissioner calls: Alexander Paterson and colonial Burma's prisons
Authors: Brown Ian 
Published: May 2007

AbstractIn 1925, Alexander Paterson, a Commissioner for Prisons in England and Wales, arrived in Rangoon to advise the local government on gaol conditions in Burma. This paper explores why the Burma prison administration invited Paterson, examines his findings and proposals – that included the suggestion that no convict should spend more than two years in gaol – and considers the fate of his recommendations. Paterson's visit and views are set in the social and political contexts of British rule in Burma at that time.
Sawtooth-like oscillations of black hole accretion disks
Authors: Matsumoto Ryoji , Machida Mami 
Published: May 2007

AbstractWe studied the origin of quasi-periodic oscillations (QPOs) of X-rays in black hole candidates by three-dimensional global resistive magnetohydrodynamic simulations of accretion disks. Initial state is a rotating disk threaded by weak toroidal magnetic fields. General relativistic effects are simulated by using the pseudo-Newtonian potential. When the temperature of the outer disk decreases, the accreting matter accumulates into an inner torus.We found that the inner torus is deformed into a crescent shape and that it shows sawtooth-like oscillations of magnetic energy with frequency 3-5Hz when the mass of the black hole is 10M⊙. The magnetic energy inside the torus is amplified until magnetic reconnection suddenly releases the accumulated magnetic energy. A new cycle of the oscillation starts when magnetic energy is amplified again. We found that high frequency QPOs with frequency around 100Hz in stellar mass black holes are excited when sawtooth-like oscillation appears in the inner torus.
Constraints on a strong X-ray flare in the Seyfert galaxy MCG–6-30-15
Authors: Goosmann R. W. , Czerny B. , Karas V. , Dovčiak M. , Ponti G. , Mouchet M. 
Published: May 2007

AbstractWe discuss implications of a strong flare event observed in the Seyfert galaxy MCG–6-30-15 assuming that the emission is due to localized magnetic reconnection. We conduct detailed radiative transfer modeling of the reprocessed radiation for a primary source that is elevated above the disk. The model includes relativistic effects and Keplerian motion around the black hole. We show that for such a model setup the observed time-modulation must be intrinsic to the primary source. Using a simple analytical model we then investigate time delays between hard and soft X-rays during the flare. The model considers an intrinsic delay between primary and reprocessed radiation, which measures the geometrical distance of the flare source to the reprocessing sites. The observed time delays are well reproduced if one assumes that the reprocessing happens in magnetically confined, cold clouds.
Dynamics of radiatively inefficient flows accreting onto radiatively efficient black hole objects
Authors: Proga Daniel 
Published: May 2007

AbstractI present results from numerical simulations of gas dynamics outside luminous accretion disks in active galactic nuclei. The gas, gravitationally captured by a super massive black hole, can be driven away by the energy and momentum of the radiation emitted during black hole accretion. Assuming axisymmetry, I study how the mass accretion and outflow rates, and the flow dynamics respond to changes in radiation heating relative to radiation pressure.I find that for a 108M⊙ black hole with the accretion luminosity of 0.6 of the Eddington luminosity the flow settles into a steady state and has two components: (1) an equatorial inflow and (2) a bipolar inflow/outflow with the outflow leaving the system along the disk rotational axis. The inflow is a realization of a Bondi–like accretion flow. The second component is an example of a non-radial accretion flow which becomes an outflow once it is pushed close to the rotational axis where thermal expansion and radiation pressure accelerate it outward.The main result of this preliminary work is that although the above two-component solution is robust, its properties are sensitive to the geometry and spectral energy distribution of the radiation field.
The Galactic Center
Authors: Genzel Reinhard , Karas Vladimír 
Published: May 2007

AbstractIn the past decade high resolution measurements in the infrared employing adaptive optics imaging on 10m telescopes have allowed determining the three dimensional orbits stars within ten light hours of the compact radio source at the center of the Milky Way. These observations show the presence of a three million solar mass black hole in Sagittarius A* beyond any reasonable doubt. The Galactic Center thus constitutes the best astrophysical evidence for the existence of black holes which have long been postulated, and is also an ideal ‘lab’ for studying the physics in the vicinity of such an object. Remarkably, young massive stars are present there and probably have formed in the innermost stellar cusp. Variable infrared and X-ray emission from Sagittarius A* are a new probe of the physical processes and space-time curvature just outside the event horizon.
The structure of the nuclear stellar cluster of the Milky Way
Authors: Schödel Rainer , Eckart Andreas 
Published: May 2007

AbstractHigh-resolution adaptive optics observations of the inner 0.5 pc of the Milky Way with multiple intermediate band filters are presented. From the images, stellar number counts and a detailed map of the interstellar extinction were extracted. The extinction map is consistent with a putative southwest-northeast aligned outflow from the central arcseconds.An azimuthally averaged, crowding and extinction corrected stellar density profile presents clear evidence for the existence of a stellar cusp around Sgr A*. Several density peaks are found in the cluster that may indicate clumping of stars, possibly related to the last epoch of star formation in the Galactic Center. An analysis of stars in the brightness range 14.25 < magK < 15.75 shows possible signs of mass segregation.
Kozai resonance model for Sagittarius A* stellar orbits
Authors: Šubr Ladislav , Karas Vladimír , Haas Jaroslav 
Published: May 2007

AbstractWe study a possibility of tidal disruptions of stars orbiting a supermassive black hole due to eccentricity oscillations driven by Kozai's mechanism. We apply the model to conditions relevant for the Galactic Centre where we consider two different sources of the perturbation to the central potential, which trigger the resonance mechanism. Firstly, it is a disc of young massive stars orbiting Sgr A* atr≳ 0.08 pc, and, secondly, a molecular circumnuclear disc. Each of the two possibilities appears to be capable of exciting eccentricities to values sufficient for the tidal disruption of ∼100 stars from the nuclear stellar cluster on a time-scale of 0.1–10 Myrs. Tidally disrupted stars may cause periods of increased accretion activity of Sgr A*.
On the nature of ultra-luminous X-ray sources from optical/IR measurements
Authors: Cropper Mark , Copperwheat Chris , Soria Roberto , Wu Kinwah 
Published: May 2007

AbstractWe present a model for the prediction of the optical/infra-red emission from ULXs. In the model, ULXs are binary systems with accretion taking place through Roche lobe overflow. We show that irradiation effects and presence of an accretion disk significantly modify the optical/infrared flux compared to single stars, and also that the system orientation is important. We include additional constraints from the mass transfer rate to constrain the parameters of the donor star, and to a lesser extent the mass of the BH. We apply the model to fit photometric data for several ULX counterparts. We find that most donor stars are of spectral type B and are older and less massive than reported elsewhere, but that no late-type donors are admissible. The degeneracy of the acceptable parameter space will be significantly reduced with observations over a wider spectral range, and if time-resolved data become available.
Variability of ultraluminous X-ray sources in the Cartwheel Ring
Authors: Wolter Anna , Trinchieri Ginevra , Colpi Monica 
Published: May 2007

AbstractThe Cartwheel is one of the most outstanding examples of a dynamically perturbed galaxy where star formation is occurring inside the ring–like structure. In previous studies with Chandra, we detected 16 Ultra Luminous X-ray sources lying along the southern portion of the ring. Their Luminosity Function is consistent with them being in the high luminosity tail of the High Mass X-ray Binaries distribution, but with one exception: source N.10. This source, detected with Chandra at LX = 1 × 1041 erg s−1, is among the brightest non–nuclear sources ever seen in external galaxies. Recently, we have observed the Cartwheel with XMM-Newton in two epochs, six months apart. After having been at its brightest for at least 4 years, the source has dimmed by at least a factor of two between the two observations. This fact implies that the source is compact in nature. Given its extreme isotropic luminosity, there is the possibility that the source hosts an accreting intermediate–mass black hole. Other sources in the ring vary in flux between the different datasets. We discuss our findings in the context of ULX models.
Radiation hydrodynamic simulations of super-Eddington accretion flows
Authors: Ohsuga Ken 
Published: May 2007

AbstractWe perform the two-dimensional radiation-hydrodynamic simulations to study the radiation pressure-dominated accretion flows around a black hole (BH). Our simulations show that the highly supercritical accretion flow (mass accretion rate is much larger than the critical value) is composed of the disk region and the outflow region above the disk.The radiation force supports the thick disk and drives the outflow. The photon trapping plays an important role within the disk, reducing the disk luminosity. On the other hand, in the case that mass accretion rate moderately exceeds the critical value, we find that the disk is unstable and exhibits the limit-cycle oscillations. The disk oscillations in our simulations nicely fit to the variation amplitude and duration of quasi-periodic luminosity variations observed in the GRS 1915+105 microquasar.