bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gravitons, induced geometry and expectation value formalism at finite temperature
Authors: Manoukian E.B. , Sukkhasena S. 
Published: May 2008

AbstractAfter establishing the positivity constraint and spin content of the theory for gravitons interacting with a necessarily, and a priori, non‐conserved external energy‐momentum tensor, the expectation value formalism of the theory is developed at finite temperature in the functional differential treatment of quantum field theory. The necessity of having, a priori, a non‐conserved external energy‐momentum tensor is an obvious technical requirement so that its respective ten components may be varied independently in order to generate expectation values and non‐linearities in the theory. The covariance of the induced Riemann curvature tensor, in the initial vacuum, is established even for the quantization in a gauge corresponding only to two physical states of the gravitons as established above. As an application, the induced correction to the metric and the underlying geometry is investigated due to a closed string arising from the Nambu action as a solution of a circularly oscillating string as, perhaps, the simplest generalization of a limiting point‐like object. Finally it is discussed on why the geometry of spacetime may, in general, depend on temperature due to radiative corrections and its physical significance is emphasized.
Expression and sub‐cellular localization of the CCAAT/enhancer binding protein α in relation to postnatal development and malignancy of the prostate
Authors: Zhang Juan , Wilkinson John Erby , Gonit Mesfin , Keck Rick , Selman Steven , Ratnam Manohar 
Published: May 2008

AbstractBackgroundC/EBPα is a critical mediator of terminal differentiation and a tumor suppressor through its strong antiproliferative actions on cell cycle regulatory proteins. C/EBPα also appears to regulate androgen receptor (AR) AR signaling. There, is a paucity of information on the expression and sub‐cellular localization of C/EBPα in normal mouse and human prostate and in prostate cancer.MethodsImmunohistochemistry of tissues including tissue arrays, quantitative polymerase chain reaction and mRNA expression database mining.ResultsIn the mouse prostate epithelium, C/EBPα was present at 1 week postnatal localized in the cytosol, began to show nuclear localization at 8 weeks and continued to show prominent nuclear expression at 10 weeks and beyond; C/EBPα mRNA was expressed at all ages. In humans, C/EBPα showed prominent nuclear localization from peripubescence up to middle age but was sequestered in the cytosol in older individuals; the mRNA level for C/EBPα remained essentially unchanged. Most prostate adenocarcinomas expressed a range of levels of C/EBPα mRNA and protein that were relatively high in metastatic tumors in a manner that correlated with AR expression; however, most cells showed C/EBPα sequestered in the cytosol.ConclusionsTemporal changes in sub‐cellular localization of C/EBPα are consistent with a role in prostate differentiation and as a prostate tumor suppressor; the cytoplasmic sequestration of C/EBPα, unique to older human prostates, is arguably a permissive condition for the greater frequency of proliferative disorders of the prostate. In malignant prostate C/EBPα may be available to regulate AR signaling through transient changes in its sub‐cellular localization. Prostate 68: 1206–1214, 2008. © 2008 Wiley‐Liss, Inc.
Study of photodynamic and sonodynamic effect on A549 cell line by AFM and measurement of ROS production
Authors: Tomankova K. , Kolarova H. , Bajgar R. 
Published: May 2008

AbstractAtomic Force Microscopy (AFM) has been used to image the morphology of developing tumour cells and their processes. It is frequently reported that prior fixation is required for reliable imaging of cells with lower adhesive properties. In our work we used a dry scanner in non‐contact mode to image cell line A549 (human lung cancer cells). Scanning of this object is limited by construction of AFM, therefore we replenished the apparatus with an inverse optical microscope. We imaged the cancer cells before and after photodynamic effect (PDE) and sonodynamic effect (SDE) of photosensitizer ClAlPcS2. PDE was induced by an efficient light emitting diode (LED) source with total light dose of 15 J cm–2. The treatment of the cells with the photosensitizer leads to the loss of surface rigidity and eventually to dramatic changes of the cell shape. Moreover, PDE increases reactive oxygen species (ROS) at higher concentration of the sensitizer, and ultrasound exposition enhances that ROS production. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Plasmon dispersion in quantum wires at finite temperature
Authors: Vazifehshenas T. 
Published: May 2008

AbstractWe have investigated the effect of temperature on plasmon dispersion in a GaAs‐based quasi one‐dimensional electron gas (Q1DEG) by finding the roots of the temperature‐dependent dielectric function of the system in which the local field correction has been included through a generalized definition of the Hubbard approximation at low temperatures. We have compared temperature‐dependent plasmon frequencies with zero‐temperature Hubbard results and obtained an increase in plasmon energy with increasing temperature. For comparison, we have also considered the plasmon dispersion previously obtained from random phase approximation (RPA) calculations at both zero and finite temperatures. Our results show that the RPA plasma oscillations have higher energy than Hubbard approximation plasmons, not only at zero temperature but also at finite temperature. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time‐dependent density functional calculation of the energy loss of antiprotons colliding with metallic nanoshells
Authors: Quijada M. , Borisov A. G. , Muiño R. Díez 
Published: May 2008

AbstractTime‐dependent density functional theory is used to study the interaction between antiprotons and metallic nanoshells. The ground state electronic properties of the nanoshell are obtained in the jellium approximation. The energy lost by the antiproton during the collision is calculated and compared to that suffered by antiprotons traveling in metal clusters. The resulting energy loss per unit path length of material in thin nanoshells is larger than the corresponding quantity for clusters. It is shown that the collision process can be interpreted as the antiproton crossing of two nearly bi‐dimensional independent metallic systems. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The influence of radiation on ice crystal spectrum in the upper troposphere
Authors: Zeng Xiping 
Published: May 2008

AbstractThis theoretical study is carried out to investigate the effect of radiation on ice crystal spectrum in the upper troposphere. First, an explicit expression is obtained for the ice crystal growth rate that takes account of radiative and kinetic effects. Second, the expression is used to quantitatively analyse how radiation broadens the ice crystal spectrum and then to reveal a new precipitation mechanism in the upper troposphere and the stratosphere. Third, the radiative effect is used to explain the subvisual clouds near the tropopause. Copyright © 2008 Royal Meteorological Society
Some dynamical aspects of tropical cyclone concentric eyewalls
Authors: Rozoff Christopher M. , Schubert Wayne H. , Kossin James P. 
Published: May 2008

AbstractThe intensification of tropical cyclones is often interrupted by an eyewall replacement cycle, a process in which an outer eyewall forms, contracts, and replaces an inner eyewall. The radial distributions of inertial stability and diabatic heating change during such events, impacting the transverse circulation. To examine the effects of such changes, an analytical solution of the transverse circulation equation associated with a balanced vortex model is derived using a parameterization that distinguishes five radial regions subdividing the domain by each region's values of inertial stability and diabatic heating. These regions define the eye, inner eyewall, moat, outer eyewall, and far‐field. In mature concentric eyewall situations, the solutions do not support the hypothesis that the inner eyewall collapses as a direct result of subsidence from the outer eyewall. However, the results suggest subsidence and warming temperatures in the moat are governed by enhanced inertial stability associated with a strengthening outer eyewall. The model solutions also illustrate how the diabatic heating in the inner eyewall, imbedded in a region of high inertial stability, induces larger temperature tendencies than the diabatic heating in the outer eyewall, which borders the far‐field region of low inertial stability. Thus, as the inner eyewall dies, the storm temporarily loses its ability to produce an intense, localized warm region. This ability is restored during the contraction and intensification of the outer eyewall. These results provide a partial dynamical explanation of how an eyewall replacement cycle can act as a temporary brake on tropical cyclone intensification. Copyright © 2008 Royal Meteorological Society
Analysis of convectively‐generated gravity waves in mesoscale model simulations and wind‐profiler observations
Authors: Chagnon Jeffrey M. , Gray Suzanne L. 
Published: May 2008

AbstractThe characteristics of convectively‐generated gravity waves during an episode of deep convection near the coast of Wales are examined, in high‐resolution mesoscale simulations with the Met Office Unified Model and in observations from a mesosphere–stratosphere–troposphere wind‐profiling Doppler radar. In this episode, deep convection reached the tropopause and generated vertically‐propagating high‐frequency waves in the lower stratosphere that produced vertical‐velocity perturbations of order of 1 ms−1. Wavelet analysis is applied in order to determine the characteristic periods and wavelengths of the waves. Both in the simulations and in the observations, the wavelet spectra contain several distinct preferred scales, indicated by multiple spectral peaks. The peaks are most pronounced in the horizontal spectra at several wavelengths less than 50 km. Although these peaks are most clear, and of largest amplitude, in the highest‐resolution simulations (with 1 km horizontal grid length), they are also evident in coarser simulations (with 4 km horizontal grid length). Peaks also exist in the vertical and temporal spectra (at approximately 2.5–4.5 km and 10–30 min respectively), with good agreement between simulation and observation. Two‐dimensional (wave‐number–frequency) spectra demonstrate that each of the selected horizontal scales contains peaks at each of the preferred temporal scales revealed by the one‐dimensional spectra alone. Copyright © 2008 Royal Meteorological Society
A critique of Emanuel's hurricane model and potential intensity theory
Authors: Smith Roger K. , Montgomery Michael T. , Vogl Stefanie 
Published: May 2008

AbstractWe present a critique of Emanuel's steady‐state hurricane model, which is a precursor to his theory for hurricane potential intensity (PI). We show that a major deficiency of the theory is the tacit assumption of gradient wind balance in the boundary layer, a layer that owes its existence to gradient wind imbalance in the radial momentum equation. If a more complete boundary‐layer formulation is included using the gradient wind profiles obtained from Emanuel's theory, the tangential wind speed in the boundary layer becomes supergradient, invalidating the assumption of gradient wind balance. We show that the degree to which the tangential wind is supergradient depends on the assumed boundary‐layer depth. The full boundary‐layer solutions require a knowledge of the tangential wind profile above the boundary layer in the outer region where there is subsidence into the layer and they depend on the breadth of this profile. This effect is not considered in Emanuel's theory. We argue that a more complete theory for the steady‐state hurricane would require the radial pressure gradient above the boundary layer to be prescribed or determined independently of the boundary layer.The issues raised herein highlight a fundamental problem with Emanuel's theory for PI, since that theory makes the same assumptions as in the steady‐state hurricane model. Our current findings together with recent studies examining intense hurricanes suggest a way forward towards a more consistent theory for hurricane PI. Copyright © 2008 Royal Meteorological Society
Fair inter‐TAP routing and backhaul assignment for wireless mesh networks
Authors: Lin Frank Y. S. , Wen Y. F. 
Published: May 2008

AbstractAlthough limiting the number of backhauls, specifically chosen transit access points (TAPs) that forward traffic from other TAPs, reduces the overall costs of a wireless mesh network (WMN), an egress bottleneck is induced, which aggregates traffic and limits the bandwidth. To avoid such problems while working to minimize budgetary expenses, we balanced traffic flow on ‘to‐be‐determined’ backhauls and adjacent links, a mixed nonlinear‐and integer‐programming problem that minimizes the aggregated flow subject to budget, backhaul assignment, top‐level load‐balanced routing, and link capacity constraints. Two algorithms are proposed, weighted backhaul assignment (WBA) and greedy load‐balanced routing (GLBR), that operate in conjunction with Lagrangean relaxation (LR), used for constructing LR‐based heuristics and also as a means of quantification and evaluation of the proposed algorithms. Experiment results show that the proposed algorithms achieve near‐optimization, outperforming related solutions. Copyright © 2008 John Wiley & Sons, Ltd.
Reference‐free x‐ray fluorescence analysis of an ancient Chinese ceramic
Authors: Beckhoff B. , Kolbe M. , Hahn O. , Karydas A. G. , Zarkadas Ch. , Sokaras D. , Mantler M. 
Published: May 2008

AbstractThe investigation of an ancient Chinese ceramic served to further develop and validate fundamental parameter‐based quantitation procedures in reference‐free x‐ray fluorescence (XRF) analysis. The XRF measurements of this sample were performed at the four‐crystal monochromator beamline of the Physikalisch‐Technische Bundesanstalt (PTB) at the BESSY II synchrotron radiation facility employing different excitation energies. The parallel processing of the XRF spectra recorded at different excitation energies provides a means to simultaneously evaluate relevant fundamental parameters and secondary enhancement processes such as those induced by photoelectrons. Employing well‐characterized and absolutely calibrated instrumentation, all experimental parameters involved in XRF are known for small relative uncertainties allowing for a completely reference‐free quantitation. Apart from traces of rare earth elements, the analytical results of the Chinese ceramic achieved by reference‐free XRF are in line with target values given within a proficiency test of the International Atomic Energy Agency (IAEA) involving atomic and nuclear methods. Copyright © 2008 John Wiley & Sons, Ltd.
Tongue twisters: feeding enrichment to reduce oral stereotypy in giraffe
Authors: Fernandez Loraine Tarou , Bashaw Meredith J. , Sartor Richard L. , Bouwens Nichole R. , Maki Todd S. 
Published: May 2008

AbstractStereotypic behavior has been well‐studied and documented in a variety of animals including primates, carnivores, and domesticated ungulates. However, very little information is known about stereotypic behavior of captive exotic ungulates. Giraffe have been found to perform a wide range of stereotypic behaviors. According to a survey of zoological institutions, oral stereotypies, specifically the licking of nonfood objects are the most prevalent stereotypic behaviors observed in giraffe. Their performance appears to be related to feeding and rumination and may be a result of the inability of a highly motivated feeding behavior pattern, tongue manipulation, to be successfully completed. To test this hypothesis, the indoor and outdoor feeders for three giraffe housed at Zoo Atlanta were modified to require the giraffe to perform more naturalistic and complex foraging behaviors. Data were collected using instantaneous scan sampling in both exhibit and holding areas. Our results showed that, for the giraffe that engaged in the highest rates of oral stereotypic behavior in the baseline, more complex feeders that required tongue use to access grain or alfalfa had the greatest effect on behavior. For the giraffe that performed low baseline rates of oral stereotypic behavior, adding slatted tops to the alfalfa feeders indoors virtually eliminated the behavior. Although some changes in ruminating and feeding behavior were observed, the decreases in stereotypic behavior were not associated with the changes in ruminating or feeding behavior. These results provide evidence for the hypothesis that oral stereotypy in herbivores can be reduced by encouraging giraffe to engage in more naturalistic foraging behavior. Zoo Biol 27:200–212, 2008. © 2008 Wiley‐Liss, Inc.
Physical and chemical properties of alumina bleached cottonseed oil
Authors: Kuck J. C. , Pons W. A. , Frampton V. L. 
Published: May 2008

AbstractNo detectable amount of polymerization or triene conjugation occurred on bleaching refined cottonseed oil with either activated alumina or with sulfurous acid‐treated alumina, although insignificant amounts of diene conjugation andtrans‐ isomerization occurred. AOM stability, tocopherol content, and fatty acid composition, as determined by gas‐liquid chromatography (GLC), were comparable with values obtained with oil bleached with natural earth. Hydrogenation of the oils proceeded normally. Taste panel evaluations of the deodorized oils revealed their flavor stability to be equal to that of the same oil bleached with AOCS official earth.
Long Chain Fatty Acid Uptake In Vivo: Comparison of [125I]‐BMIPP and [3H]‐Bromopalmitate
Authors: Shearer Jane , Coenen Kimberly R. , Pencek R. Richard , Swift Larry L. , Wasserman David H. , Rottman Jeffrey N. 
Published: May 2008

AbstractInsulin resistance is characterized by increased metabolic uptake of fatty acids. Accordingly, techniques to examine in vivo shifts in fatty acid metabolism are of value in both clinical and experimental settings. Partially metabolizable long chain fatty acid (LCFA) tracers have been recently developed and employed for this purpose: [9,10‐3H]‐(R)‐2‐bromopalmitate ([3H]‐BROMO) and [125I]‐15‐(ρ‐iodophenyl)‐3‐R,S‐methylpentadecanoic acid ([125I]‐BMIPP). These analogues are taken up like native fatty acids, but once inside the cell do not directly enter β‐oxidation. Rather, they become trapped in the slower processes of ω and α‐oxidation. Study aims were to (1) simultaneously assess and compare [3H]‐BROMO and [125I]‐BMIPP and (2) determine if tracer breakdown is affected by elevated metabolic demands. Catheters were implanted in a carotid artery and jugular vein of Sprague–Dawley rats. Following 5 days recovery, fasted animals (5 h) underwent a rest (n = 8) or exercise (n = 8) (0.6 mi/h) protocol. An instantaneous bolus containing both [3H]‐BROMO and [125I]‐BMIPP was administered to determine LCFA uptake. No significant difference between [125I]‐BMIPP and [3H]‐BROMO uptake was found in cardiac or skeletal muscle during rest or exercise. In liver, rates of uptake were more than doubled with [3H]‐BROMO compared to [125I]‐BMIPP. Analysis of tracer conversion by TLC demonstrated no difference at rest. Exercise resulted in greater metabolism and excretion of tracers with ∼37% and ∼53% of [125I]‐BMIPP and [3H]‐BROMO present in conversion products at 40 min. In conclusion, [3H]‐BROMO and [125I]‐BMIPP are indistinguishable for the determination of tissue kinetics at rest in skeletal and cardiac muscle. Exercise preferentially exacerbates the breakdown of [3H]‐BROMO, making [125I]‐BMIPP the analogue of choice for prolonged (>30 min) experimental protocols with elevated metabolic demands.
Uniqueness of Moore's higher reciprocity law at the prime 2 for real number fields
Authors: Guo Xuejun , Qin Hourong 
Published: May 2008

AbstractLet F be a real number field with r1 real embeddings. In this paper, we prove that the sequenceis a complex, where are the Tate cohomology groups. Moreover if i ≡ 0, 1, or 2 (mod 4), then it is exact; if i ≡ 3 (mod 4), then the homology group at the second term of this complex is isomorphic to .
WARPED PRODUCT SEMI-SLANT SUBMANIFOLDS IN LOCALLY RIEMANNIAN PRODUCT MANIFOLDS
Authors: ATÇEKEN MEHMET 
Published: May 2008

AbstractIn this paper, we prove that there are no warped product proper semi-slant submanifolds such that the spheric submanifold of a warped product is a proper slant. But we show by means of examples the existence of warped product semi-slant submanifolds such that the totally geodesic submanifold of a warped product is a proper slant submanifold in locally Riemannian product manifolds.
MULTIDIMENSIONAL HARDY-TYPE INEQUALITIES VIA CONVEXITY
Authors: OGUNTUASE JAMES A. , PERSSON LARS-ERIK , ČIŽMEŠIJA ALEKSANDRA 
Published: May 2008

AbstractLet an almost everywhere positive function Φ be convex forp>1 andp<0, concave forp∈(0,1), and such thatAxp≤Φ(x)≤Bxpholds on$\mathbb {R}_{+}$for some positive constantsA≤B. In this paper we derive a class of general integral multidimensional Hardy-type inequalities with power weights, whose left-hand sides involve$\Phi ( \int _0^{x_1} \cdots \int _0^{x_n} f(\t )\,d\t )$instead of$[ \int _0^{x_1} \cdots \int _0^{x_n} f(\t ) \, d\t ]^p$, while the corresponding right-hand sides remain as in the classical Hardy’s inequality and have explicit constants in front of integrals. We also prove the related dual inequalities. The relations obtained are new even for the one-dimensional case and they unify and extend several inequalities of Hardy type known in the literature.
Digestion of invertebrate neuropeptides by preparations from the free-living nematodePanagrellus redivivus
Authors: Masler E.P. 
Published: May 2008

AbstractProteases in the soluble fraction of homogenates prepared from the free-living nematodePanagrellus redivivushydrolysed the amidated invertebrate neuropeptides FMRFa and FLRFa, and nematode FMRFa-like peptides (FLPs) KPNFLRFa (FLP-1-H), APKPKFIRFa (FLP-5-A), KNEFIRFa (FLP-8), KPSFVRFa (FLP-9), RNKFEFIRFa (FLP-12) and KHEYLRFa (FLP-14)in vitro. Results were assessed by analysing reaction components with RP-HPLC, UV detection at 210 nm and peak integration. Based upon substrate peak size, more than 90% of most of the peptide substrates was consumed after 1 h at 27°C, but digestion was not complete even with a crude protease mixture. Two peptides, FLP-12 and FLP-14, were significantly less susceptible to digestion than the others. FLP-12 was the least susceptible of all sequences (71% loss;P < 0.0001), while FLP-14 was digested less (84% loss;P < 0.0004) than all but FLP-12. Product peak digestion patterns of FLP-12, a second nonapeptide (FLP-5-A), and FMRFa, incubated with aminopeptidase (amastatin) and serine endoprotease (AEBSF) inhibitors, demonstrated highly specific behaviours of each sequence to protease cleavage. Amastatin significantly (P < 0.03) reduced digestion of FLP-12 (54% loss) and FMRFa (61% loss;P < 0.0005), but had no effect on FLP-5-A. AEBSF had no protective effect on FMRFa but significantly decreased hydrolysis of FLP-5-A (77% loss;P < 0.0001) and FLP-12 (59% loss;P < 0.03). The combination of both inhibitors had additive effects only for FMRFa (34% loss;P < 0.0005). Further analysis of FMRFa digestion using peptides withd-amino acid substitutions demonstrated nearly complete protection of FdMRFa (2% loss;P < 0.0001) from all proteolytic digestion, whereas digestion of FMRdFa was complete. Results suggest that in addition to aminopeptidase and serine proteases, both deamidase and aminopeptidase P participate in neuropeptide metabolism inP. redivivus.