bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Budgeting: The Perspective of State Agencies
Authors: LU YI
Published: November 2007

Although performance‐based budgeting requirements are pervasive, what remains a challenge is how to gain the support from all stakeholders in the budget process that are essential to the integration of performance information with budgeting. This study examines the perspective and role of state agencies on performance budgeting. The finding indicates that for agencies to conduct performance‐informed budgeting, the focus needs to be on elevating managerial capacity to use performance information, and improving measurement quality. Moreover, it is crucial to recognize that performance budgeting is a collaborative process in which each participant plays a valuable role.
Appraising Commitments and Guarantees with Option Prices1
Authors: HANSEN SØREN LOENTOFT , DOTHAN MICHAEL U. , THOMPSON FRED
Published: November 2007

Budgetary decision‐making is prone to myopia and to tunnel vision. Pension commitments suffer from both of these pathologies. In this case, we look closely at the State of Oregon's Public Employee Retirement System to show how the disclosure standards adopted by the Government Accounting Standards Board (GASB) help correct the fiscal vision of state and local governments and further conclude that postemployment commitments ought to be comprehensively examined in GASB's review of its accounting and reporting standards scheduled for 2008, ideally from the standpoint of present‐value budgeting.
While the Cat's Away, Do the Mice Play? Maternal Employment and the After‐School Activities of Adolescents*
Authors: Lopoo Leonard M.
Published: November 2007

Objective. This study determines if a relationship exists between a mother's employment and the activities in which her adolescent children participate after school.

Methods. The author uses panel data from the 1996 Survey of Income and Program Participation with logit and fixed‐effects logit models to estimate this relationship.

Results. Fixed‐effects models suggest a positive relationship between maternal employment and participation in lessons after school for the adolescent children of married women and also for those with at least a high school education. Maternal employment is also positively related to sports participation for the adolescent children of unmarried mothers.

Conclusions. First, this article shows the importance of accounting for unobserved heterogeneity in inquiries into the links between maternal employment and adolescent outcomes. Second, it suggests that high‐socioeconomic‐status mothers may use after‐school activities, particularly lessons, as a form of after‐school care, while unmarried mothers may use sports.
Living Arrangements and School Dropout Among Minor Mothers Following Welfare Reform*
Authors: Koball Heather
Published: November 2007

Objectives. The 1996 welfare reform laws required that parents under the age of 18 live with their parents or an adult relative and enroll in school to be eligible for welfare benefits. This study examines whether minor mothers were less likely to drop out of school and more likely to live with parents following welfare reform.

Methods. Data from the National Education Longitudinal Survey 1988 and the National Longitudinal Survey of Youth 1997 were used in difference‐in‐difference analyses.

Results. Following welfare reform, minor mothers' co‐residence with parents increased and their drop‐out rates decreased.

Conclusions. Welfare reform requirements are associated with changes in living arrangements and drop‐out rates of minor mothers.
Evaluating the effect of the new alignment algorithm for longitudinal series of Heidelberg retina tomography images
Authors: Bergin Ciara , Garway‐Heath David F. , Crabb David P.
Published: November 2007

Purpose:  To evaluate the impact of a new image‐alignment algorithm on the repeatability of longitudinal measurements obtained from Heidelberg retina tomograph (HRT) images.

Methods:  HRTI and HRTII image series from 124 patients with glaucoma or ocular hypertension were made available from previously reported studies and were reprocessed with the old and new image‐alignment algorithms. Improvements afforded by the new alignment algorithm were examined by considering statistically significant improvement in repeatability of specific stereometric parameters (SP), namely rim area (RA), rim volume (RV), cup volume (CV) and cup shape measure (CSM). A further comparison was made by examining reduction in the variability of pixel‐by‐pixel height measures within image series.

Results:  In some HRT image series, the new algorithm automatically corrected obvious misalignment events that occurred with the previous algorithm. However, average improvement in repeatability of the SP in HRTI image series was not statistically significant (P = 0.13) and there was no statistically significant reduction in pixel‐by‐pixel height measurement variability (P =0.73). In HRTII image series, there was evidence of improvement, on average, in the repeatability of some parameters (RA, P = 0.01; RV, P = 0.02; CSM, P = 0.05), but not in CV (P = 0.22). There was a large reduction in pixel‐by‐pixel variability in HRTII image series (P < 0.001).

Conclusion:  There was no evidence to show that the new algorithm improved repeatability, on average, in HRTI images. However, the application of the new algorithm to HRTII image series marginally improved repeatability in stereometric measures and yielded a significant reduction in pixel‐by‐pixel variability.
Turned away?
Authors: Cooley Laurence , Rutter Jill
Published: November 2007

Laurence Cooley and Jill Rutter examine whether government reaction to the hysteria that has surrounded asylum seekers in the UK has had negative impacts on those who genuinely deserve our protection
Prescription Practices and Empirical Efficacy of Psychopharmacologic Treatments for Pediatric Major Depressive Disorder
Authors: Hirsch Amanda J. , Carlson John S.
Published: November 2007

PROBLEM:  Limited research on pharmacologic treatments for pediatric major depressive disorder (MDD) exists.

METHODS:  Prescription practices data for MDD from 1,209 American Academy of Child and Adolescent Psychiatry members collected in 1998 are compared to the current empirical support for this treatment approach.

FINDINGS:  Results indicated that psychiatrists have willingly used medication as a first‐line treatment for MDD in children under age 7, despite a paucity of research support for this practice.

CONCLUSIONS:  Recent warnings regarding the use of selective serotonin reuptake inhibitors warrant the need to reexamine current prescription practices of psychiatric care providers for children diagnosed with MDD.
The nature of hypervelocity stars as inferred from their Galactic trajectories
Authors: Svensson Karl M. , Church Ross P. , Davies Melvyn B.
Published: November 2007

We have computed the Galactic trajectories of 12 hypervelocity stars (HVSs) under the assumption that they originated in the Galactic Centre. We show that eight of these 12 stars are bound to the Galaxy. We consider the subsequent trajectories of the bound stars to compute their characteristic orbital period, which is 2 Gyr. All eight bound stars are moving away from the centre of the Galaxy, which implies that the stars' lifetimes are less than 2 Gyr. We thus infer that the observed HVSs are massive main-sequence stars, rather than blue horizontal branch stars. The observations suggest that blue HVSs are ejected from the Galactic Centre roughly every 15 Myr. This is consistent with the observed population of blue stars in extremely tight orbits round the central supermassive black hole (SMBH), the so-called S-stars, if we assume that the HVSs are produced by the breakup of binaries. One of the stars in such a binary is ejected at high velocities to form a HVS; the other remains bound to the SMBH as an S-star.

We further show that the one high-velocity system observed to be moving towards the Galactic Centre, SDSS J172226.55+594155.9, could not have originated in the Galactic Centre; rather, we identify it as a halo object.
Research Letter: New Potent Indole Derivatives as Hyaluronidase Inhibitors
Authors: Ölgen Süreyya , Kaeßler Andre , Nebioğlu Doğu , Jose Joachim
Published: November 2007

Because of the physiologic importance of hyaluronidases, the identification of potent and selective inhibitors of hyaluronidases has become increasingly important. A variety of assay methods have been used for such a purpose, i.e. classical turbidimetric, viscometric and colorimetric. In this study, a modified enzymatic assay has been used to obtain a microtiter plate‐based sensitive activity screening. All inhibitors were tested in a stains‐all assay at pH 7 and in a Morgan‐Elson assay at pH 3.5. Among the tested compounds, 1, 2, 3, 6, 7, 8, 16, 17 and 18 showed good inhibition of more than 50%, so the IC50 values of these derivatives were determined in the range of 25–41 μm. The IC50 value of the most active hyaluronidase inhibitor Vcpal (6‐palmitoyl‐l‐ascorbic acid) was measured as 8.36 μm. All inhibitors including Vcpal showed twofold less activity at pH 3.5 in a Morgan‐Elson assay. Examination of substituent effects on the activity showed that para‐positions of benzamide needs to be chlorinated or fluorinated to obtain good inhibitory effect. It was found that the introduction of a p‐fluoro benzyl ring in the indole nitrogen has a positive effect for the inhibitory effects of both indole‐2‐ and 3‐carboxamide derivatives.
The globalisation of General Principle 7: transforming the market for corporate control in Australia and Europe?
Authors: Dignam Alan
Published: November 2007

The integration of national financial markets over the past 30 years has resulted in a globalised market for corporate control which has increased both the opportunities for companies to fund acquisitions and the possibility of being acquired. Takeovers and mergers have, as a result, become a matter of some concern for governments, as they try to encourage the development of financial markets but also deal with the consequences of a globalised market for corporate control, where even companies regarded as national champions are within the reach of a foreign takeover. In the course of the last decade General Principle No 7 of the UK Takeover Code, that shareholders should decide the outcome of a takeover bid, has been adopted in many jurisdictions around the world and has formed the heart of the EU Directive on Takeovers. The Principle is however a controversial one, as its adoption is often viewed in civil law jurisdictions as an attack on a core part of a social market system. This has been particularly evident in the debate on the EU Directive on Takeovers. A number of common law heritage countries have also based their takeover regime around General Principle No 7 and many of these common law heritage counties have similarities with social market systems, in that they have less significant stock exchanges than the UK, the make up of their shareholding base is more concentrated and employment protections are more extensive. A central jurisdiction in that overlap is Australia, with exactly this combination. The purpose of this paper is to examine the historical effect of introducing UK takeover principles into the Australian system, by creating an empirical data set of takeovers of Australian listed companies covering the period before and after those UK-based principles were introduced. In doing so the paper found that factors such as concentrated ownership, capital controls and protective labour law have significant effects on the market for corporate control. There was no transforming effect evident in adopting an anti-managerial pro-shareholder takeover regime. As such, the fear that the adoption of a standardised EU-wide takeover Directive, along the lines of the UK Panel on Takeovers and Mergers' shareholder-oriented General Principle 7, would have a negative transforming effect on social market systems appears, on the Australian evidence, to be overblown, while other key features of such systems, particularly concentrated ownership and protective labour laws, remain in place.
Duodenal bicarbonate secretion in rats: stimulation by intra‐arterial and luminal guanylin and uroguanylin
Authors: Bengtsson M. W. , Jedstedt G. , Flemström G.
Published: November 2007

Aim:  Uroguanylin and guanylin are endogenous ligands for guanylate cyclase C, an upstream regulator of the cystic fibrosis transmembrane resistance (CFTR) anion channel, and both peptides increase intestinal anion export in vitro. We have compared the effects of close intra‐arterial and luminal administration of uroguanylin and guanylin on duodenal bicarbonate secretion in vivo and studied the interactions with melatonin and cholinergic stimulation.

Methods:  Lewis × Dark Agouti rats were anaesthetized and a segment of the proximal duodenum with intact blood supply was cannulated in situ. Mucosal bicarbonate secretion (pH stat) was continuously recorded and peptides were infused intra‐arterially or added to the luminal perfusate.

Results:  Intra‐arterial (50–1000 pmol kg−1 h−1) as well as luminal administration (50–500 nmol L−1) of guanylin or uroguanylin caused dose‐dependent increases in the duodenal secretion. Luminal administration induced more rapidly appearing rises in secretion and the two peptides induced secretory responses of similar shape and magnitude. The melatonin MT2‐selective antagonist luzindole (600 nmol kg−1) significantly depressed the response to intra‐arterial guanylins but did not affect secretion induced by luminal guanylins. Similarly, the muscarinic antagonist atropine (0.75 μmol kg−1 followed by 0.15 μmol kg−1 h−1) abolished the response to intra‐arterial uroguanylin but caused only slight suppression of the response to luminal uroguanylin.

Conclusions:  Intra‐arterial as well as luminal uroguanylin and guanylin are potent stimuli of duodenal mucosal bicarbonate secretion in vivo. The response to luminal guanylins reflects an action at apical receptors. Stimulation by parenteral guanylins, in contrast, is under cholinergic influence and interacts with melatonin produced by mucosal enteroendocrine cells.
UV Protective Effects of DNA Repair Enzymes and RNA Lotion
Authors: Ke Malcolm S. , Camouse Melissa M. , Swain Freddie R. , Oshtory Shaheen , Matsui Mary , Mammone Thomas , Maes Daniel , Cooper Kevin D. , Stevens Seth R. , Baron Elma D.
Published: November 2007

Solar UV radiation is known to cause immune suppression, believed to be a critical factor in cutaneous carcinogenesis. Although the mechanism is not entirely understood, DNA damage is clearly involved. Sunscreens function by attenuating the UV radiation that reaches the epidermis. However, once DNA damage ensues, repair mechanisms become essential for prevention of malignant transformation. DNA repair enzymes have shown efficacy in reducing cutaneous neoplasms among xeroderma pigmentosum patients. In vitro studies suggest that RNA fragments increase the resistance of human keratinocytes to UVB damage and enhance DNA repair but in vivo data are lacking. This study aimed to determine the effect of topical formulations containing either DNA repair enzymes (Micrococcus luteus) or RNA fragments (UVC‐irradiated rabbit globin mRNA) on UV‐induced local contact hypersensitivity (CHS) suppression in humans as measured in vivo using the contact allergen dinitrochlorobenzene. Immunohistochemistry was also employed in skin biopsies to evaluate the level of thymine dimers after UV. Eighty volunteers completed the CHS portion. A single 0.75 minimum erythema dose (MED) simulated solar radiation exposure resulted in 64% CHS suppression in unprotected subjects compared with unirradiated sensitized controls. In contrast, UV‐induced CHS suppression was reduced to 19% with DNA repair enzymes, and 7% with RNA fragments. Sun protection factor (SPF) testing revealed an SPF of 1 for both formulations, indicating that the observed immune protection cannot be attributed to sunscreen effects. Biopsies from an additional nine volunteers showed an 18% decrease in thymine dimers by both DNA repair enzymes and RNA fragments, relative to unprotected UV‐irradiated skin. These results suggest that RNA fragments may be useful as a photoprotective agent with in vivo effects comparable to DNA repair enzymes.
Collagen Cross Linking Agents: Design and Development of a Multifunctional Cross Linker
Authors: Givens Richard S. , Yousef Abraham L. , Yang Shaorong , Timberlake George T.
Published: November 2007

A new cross linking reagent based on the first‐generation polyamidoamine dendrimer (G.1 PAMAM) has been synthesized by reaction of the PAMAM with eight equivalents of p‐nitrophenyl diazopyruvate. The resulting water‐soluble octadiazopyruvoyl PAMAM (8G.1 DAP, 1.3) was shown to undergo Wolff rearrangements upon photolysis in methanol at λ > 300 nm to yield the methyl esters of the ketenes formed from the loss of nitrogen. 8G.1 DAP also forms strong bonds with dehydrated collagen with glass as high as 36 N cm−2. Collagen to collagen bonds with tensile strengths as high as 92 N cm−2 were observed with fully dehydrated tissues. The bonding decreased rapidly with increasingly hydrated tissue possibly due to the increased distance between the collagen fibrils and the competition of H2O for the free ketene functions.
Cessation in the use of tobacco – pharmacologic and non‐pharmacologic routines in patients
Authors: Quist‐Paulsen Petter
Published: November 2007

Introduction:  Approximately one‐third of the adult population in industrial countries and 70% in several Asian countries are daily smokers. Tobacco is now regarded as the world's leading cause of death. Approximately two‐thirds of lifelong smokers eventually die because of smoking. Smoking cessation is the most effective action to reduce mortality in patients with chronic obstructive pulmonary disease (COPD) and coronary heart disease.

Objective:  The aim of this study was to determine the effectiveness of smoking cessation programmes in patients with smoking‐related disorders.

Methods:  Medline was searched for studies of interventions for smoking cessation in patients.

Results:  In patients with cardiovascular diseases and COPD, smoking cessation programmes with behavioural support over several months significantly increase quit rates. The intensity of the programmes seems to be proportional to the effect. A long follow‐up period is probably the most important element in the programmes. Even the most intensive programmes are very cost‐effective in terms of cost per life‐year gained. Effective programmes can be delivered by personnel without special education in smoking cessation using simple intervention principles.

Conclusions:  In patients with smoking‐related disorders, smoking cessation interventions with several months of follow‐up are effective and easily applicable in clinical practice. Wider implementation of such programmes would be a cost‐effective way of saving lives.

Please cite this paper as: Quist‐Paulsen P. Cessation in the use of tobacco – pharmacologic and non‐pharmacologic routines in patients. The Clinical Respiratory Journal 2008; 2: 4–10.
Assessing the Viability of the Independent Practice of Dental Hygiene – A Brief Communication
Authors: Beach M. Miles , Shulman Jay D. , Johns Glenna , Paas Jeffrey C.
Published: November 2007

Background: This paper deals with the economics of the independent dental hygiene practice.

Methods: Using historical data from dental practices in Cincinnati, Ohio, we developed a business model for an independent hygiene practice. We tested the sensitivity of the model to variations in key assumptions (initial capitalization, interest, employee salary, and owner’s draw). We described the profitability on the basis of the breakeven point.

Results: Under the most permissive regulatory and financial environment, the practice would breakeven after 26 months. However, the owner would not equal the earnings of a salaried hygienist until the initial loan is paid off after 7 years. The model was not sensitive to 20 percent changes in the key assumptions.

Conclusions: Under ideal circumstances, an independent hygiene practice could be profitable.
DYNAMICAL NOISE FILTERING IN CHAOS SYNCHRONIZATION
Authors: LAI C. H. , WANG J.
Published: November 2007

In this talk, we argue that in a chaotic synchronization system whose driving signal is exposed to channel noise, the estimation of the drive system state can be greatly improved by applying the dynamical noise filtering to the response system states. We show that if the noise is bounded, the estimation errors can be made arbitrarily small. This property can be exploited in the design of an alternative scheme for digital communications. Further details can be found in Ref. [1].
CHARACTERISTICS OF DISCONTINUOUS AND NONINVERTIBLE 2-D MAPS
Authors: HE DA-REN
Published: November 2007

This paper presents a review on recent investigations about the classic dynamics general features of the noninvertible and discontinuous two-dimensional maps. For concreteness we consider a system with phase space divided into two distinct but complementary regions R1 and R2. They are the domains of the map functions f1(x) and f2(x), respectively. The common features of the systems include: the stochastic web formed by image set of discontinuous borderline; phase collapse caused by the irreversibility (quasi-dissipation); fat fractal forbidden web; riddled-like attraction basin and the induced unpredictability of attractors. Several different cases where f1(x) and f2(x) are both area preserving; one is area preserving and another is dissipative; or both are dissipative have been studied. In all the cases the dynamics features can be displayed, however with different characteristics. The features are interesting and can be verified experimentally.
A POSSIBLE NEW ROUTE TO CHAOS VIA SEMICONDUCTOR SUPERLATTICES
Authors: WANG X. R. , SUN Z. Z. , ZHANG ZHENYU
Published: November 2007

Our current understanding of routes to chaos is mainly based on torus bifurcation where new periods are generated, the period-doubling mechanism revealed in the logistic map, and intermittency where periodic and burst motion appear alternatively. We present a possible new route to chaos based on our geometric picture of the frequency-locking of limit-cycles in semiconductor superlattices. In the period-double route and/or its variations, the period increases exponentially with bifurcation order, whereas the period in the new route increases linearly with the order of bifurcations.
INTERFACE THERMAL RESISTANCE BETWEEN FRENKEL-KONTOROVA AND FERMI-PASTA-ULAM LATTICES
Authors: LAN JINGHUA , WANG LEI , LI BAOWEN
Published: November 2007

By connecting two dissimilar anharmonic lattices exemplified by Fermi-Pasta-Ulam (FPU) model and Frenkel-kontorova (FK) model, we successfully build up one dimensional thermal diode. We find the rectifying effect is closely related to asymmetric interface thermal resistance (Kapitza resistance). And the asymmetric thermal resistance depends on how the temperature gradient is applied. Moreover, a qualitative relationship between the thermal rectification and the phonon spectra is proposed.
SIZE-DEPENDENT MELTING TEMPERATURE AND THERMAL CONDUCTIVITY OF NANOSCALE SEMICONDUCTORS
Authors: LIANG L. H. , LI BAOWEN
Published: November 2007

A model describing size-dependent melting temperature and thermal conductivity of nanosemiconductors is proposed based on Lindermann's melting criterion and Debye model. By the atomic thermal vibration consideration and by introducing intrinsic size effect of phonon velocity and mean free path combined with surface scattering effect, the model predicts that the melting temperature and thermal conductivity of nanosemiconductors decrease as the size reduces. The size effect depends on such material parameters as the vibration entropy, mean free path, the characteristic crystal size and surface roughness. The predictions are in agreement with experimental results of Si nanoparticles, nanowires and thin films.
DYNAMICS AND STRUCTURE OF GAS-LIQUID INTERFACE
Authors: OGUSHI FUMIKO , YUKAWA SATOSHI , ITO NOBUYASU
Published: November 2007

The structure and the dynamics of the gas-liquid phase interface of the three-dimensional Lennard-Jones (12-6) particle system are studied using nonequilibrium molecular dynamics simulation. Heat flux maintains the system into a gas-liquid coexisting state with a steady interface. In the steady state, the interface shows an asymmetric structure and this is well described by a free energy density model with an asymmetric double-well form. When the system approaches to the steady state, a gas of the temperature profile appears between each phase and the gap value is relaxed to that in the steady state following [Formula: see text] for large t . It is observed that heat resistance exists in gas-liquid interface in this scale.
WEIGHTED ACCELERATED GROWTH MODEL OF COMPLEX NETWORKS
Authors: LEUNG C. C. , CHAU H. F.
Published: November 2007

We introduce and study a toy model which mimics the structure formation of a typical weighted network in the real world. In particular, the organizational structures of our networks are found to be consistent with real-world networks.
FACTORIZABLE LANGUAGE REVISITED FROM DYNAMICS TO BIOLOGY
Authors: HAO BAILIN , XIE HUIMIN
Published: November 2007

A formal language is called factorizable if any substring of a word in it also belongs to the language. Symbolic sequences from symbolic dynamics make factorizable languages by definition. In studying avoided and under-represented strings in bacterial genomes we have defined a factorizable language for each complete genome. Recently, in studying the problem of uniqueness of reconstruction of a protein sequence from its constituent K -peptides we encounter again factorizable language which helps to build a finite state automaton to recognize the uniqueness of reconstruction. We present a brief review of these applications of factorizable languages from dynamics to biology.
NEURONAL NETWORK GROWTH: MODEL AND EXPERIMENT
Authors: JIA L. C. , LAI PIK-YIN , CHAN C. K.
Published: November 2007

The growth of connections in a quasi two-dimensional neuronal network in vitro is probed by the synchronized bursting frequency of the system. A model of an early stage of active search growth followed by a later stage of diffusive search mode is proposed. Our model can explain quantitatively the variation of the critical age(for synchronized firing) of the culture as a function of cell density. The later stage of growth implies a probability of connection that is exponentially decay in the mean connectivity. The biological significance of the model is discussed in the light of homeostatic feedback and plasticity.
HYDRODYNAMIC BOUNDARY CONDITION AT THE FLUID-SOLID INTERFACE
Authors: SHENG PING , QIAN TIEZHENG , WANG XIAOPING
Published: November 2007

While the no-slip boundary condition (no relative motion at the fluid-solid interface) has been universally accepted as a cornerstone of hydrodynamics, it was known for some time that it is incompatible with the moving contact line, defined as the motion of the line of intersection of the immiscible (two phase) fluid-fluid interface with the solid wall. By employing Onsager's principle of minimum energy dissipation, we show in this work that a continuum hydrodynamics, comprising the equations of motion as well as the relevant boundary conditions, can be obtained which resolves the moving contact line problem. Our derivation reveals that just as other dissipative system dynamics, the fluid-solid interfacial boundary condition should be consistent with the framework of linear response theory. Implications of our results are discussed.
MULTISCALE THEORY OF FLUCTUATING INTERFACES: RENORMALIZATION AND SELF-ORGANIZATION
Authors: HASELWANDTER CHRISTOPH A. , VVEDENSKY DIMITRI D.
Published: November 2007

A general procedure is presented for the multiscale analysis of atomistic models of fluctuating interfaces driven by the deposition of new material. Beginning with a lattice Langevin formulation of kinetic Monte Carlo simulations, we derive stochastic partial differential equations by regularizing the atomistic transition rules. Subsequent coarse-graining is accomplished by calculating renormalization-group trajectories from initial conditions determined by the regularized equations. We apply this methodology to the Wolf–Villain model of relaxation upon deposition and to a model for the self-organization of heteroepitaxial nanostructures.
TRANSPORT IN LUTTINGER LIQUIDS WITH STRONG IMPURITIES
Authors: MALININ SERGEY , NATTERMANN THOMAS
Published: November 2007

The tunnel current of a Luttinger liquid with a finite density of strong impurities is calculated using an instanton approach. For very low temperatures T or electric fields E the (nonlinear) conductivity is of variable range hopping (VRH) type as for weak pinning. For higher temperatures or fields the conductivity shows power law behavior corresponding to a crossover from multi- to single-impurity tunneling. For even higher T and not too strong pinning there is a second crossover to weak pinning. The determination of the position of the various crossover lines both for strong and weak pinning allows the construction of the global regime diagram.
VIBRATIONAL EXCITATIONS IN GRADED ELASTIC CHAINS
Authors: XIAO J. J. , YAKUBO K. , YU K. W.
Published: November 2007

We study vibrational excitations in linearly graded materials and/or systems. Graded systems demonstrate a unique spectrum and mode profiles, resulting in a new type of localization-delocalization transition. The nature of gradients can confine certain vibrational excitations, and redistribute them spatially. These features are contrasted to the two extreme cases of inhomogeneous system, i.e., periodically modulated system and randomly disordered system, We show in detail vibrational normal modes sustained by one dimensional graded force constant and graded mass networks, in particular, a unusual kind of modes called gradons. We propose an approach to study vibrational modes in a grades elastic system with the help of a series of homogeneous systems. Using this approach, we elaborate the features of the elastic gradons and the phonon-gradon transition.
LEE-YANG ZEROS AND QUANTUM PHASE TRANSITIONS OF NONUNIFORM ANISOTROPIC CHAINS IN A TRANSVERSE FIELD
Authors: ZHONG MING , LIU XIAOXIAN , TONG PEIQING
Published: November 2007

The quantum phase transitions of four kinds of nonuniform anisotropic XY quantum spin chains in a transverse field are studied by the Lee-Yang zeros method. It is found that the closed curves of the partition function zeros cut the positive real axis at the quantum phase transition points. The results are checked by the explicit calculations of the magnetization.
STOCHASTIC GROSS-PITAEVSKY EQUATION FOR BEC VIA COARSE-GRAINED EFFECTIVE ACTION
Authors: CALZETTA ESTEBAN , HU B. L. , VERDAGUER ENRIC
Published: November 2007

We sketch the major steps in a functional integral derivation of a new set of stochastic Gross-Pitaevsky equations (GPE) for a Bose-Einstein condensate (BEC) confined to a trap at zero temperature with the averaged effects of non-condensate modes incorporated as stochastic sources. The closed-time-path (CTP) coarse-grained effective action (CGEA) or the equivalent influence functional method is particularly suitable because it can account for the full back-reaction of the noncondensate modes on the condensate dynamics self-consistently. The Langevin equations derived here containing nonlocal dissipation together with colored and multiplicative noises are useful for a stochastic (as distinguished from a kinetic) description of the nonequilibrium dynamics of a BEC. This short paper contains original research results not yet published anywhere.
STABILIZING QUANTUM METASTABLE STATES IN A TIME-PERIODIC POTENTIAL
Authors: HO CHOON-LIN , LEE CHUNG-CHIEH
Published: November 2007

In this talk we present a model to demonstrate how time-periodic potential can be used to manipulate quantum metastability of a system. We study metastability of a particle trapped in a well with a time-periodically oscillating barrier in the Floquet formalism. It is shown that the oscillating barrier causes the system to decay faster in general. However, avoided crossings of metastable states can occur with the less stable states crossing over to the more stable ones. If in the static well there exists a bound state, then it is possible to stabilize a metastable state by adiabatically increasing the oscillating frequency of the barrier so that the unstable state eventually cross-over to the stable bound state. It is also found that increasing the amplitude of the oscillating field may change a direct crossing of states into an avoided one. Hence, one can manipulate the stability of different states in a quantum potential by a combination of adiabatic changes of the frequency and the amplitude of the oscillating barrier.
PUMPING CURRENT IN A QUANTUM DOT BY AN OSCILLATING MAGNETIC FIELD
Authors: ZENG ZHAO YANG , LI HONG , LI BAOWEN
Published: November 2007

We investigate spin and charge current through a quantum dot pumped by a time-varying magnetic field. Using the density matrix method, quantum rate equations for the electronic occupation numbers in the quantum dot are obtained and solved in the stationary state limit for a wide set of parameters. Both charge and spin currents are expressed explicitly in terms of several relevant parameters and analyzed in detail. The results suggest a way of optimizing experimental parameters to obtain an maximal spin current without the charge current flow.
How Autonomous Is Law?
Authors: Tomlins Christopher
Published: November 2007

Socio-legal scholars forever debate whether law is the product of internally constructed rules, procedures, and rationales or an effect of external social forces and interests. Traditionally, the debate pitted formalists who defended law's actual autonomy against instrumentalists who claimed law was a creature of exogenous circumstance. The debate was transformed in the later twentieth century, first by fundamental refinements in Marxist theory that produced structuralist accounts of law's relative autonomy, then by poststructural innovations in critical theory which held that all discourses (including law) were epistemically autonomous. Parallel formulations claimed not only that law was autonomous but also that law was in fact constitutive of the very social circumstances once held to determine its development. This article reviews the highlights of the debate while adopting a perspective outside it. It treats the autonomy question as relational—if law is autonomous it must still be autonomous in relation to something—and asks in relation to what? All sides in the debate assume the answer is society, so the article asks how the social became law's relational other and what other relationalities might be brought into play.
Mitochondrial adaptations to steatohepatitis induced by a methionine- and choline-deficient diet
Authors: Romestaing Caroline , Piquet Marie-Astrid , Letexier Dominique , Rey Benjamin , Mourier Arnaud , Servais Stéphane , Belouze Maud , Rouleau Vincent , Dautresme Marianne , Ollivier Isabelle , Favier Roland , Rigoulet Michel , Duchamp Claude , Sibille Brigitte
Published: November 2007

Nonalcoholic fatty liver disease (NAFLD) has become common liver disease in Western countries. There is accumulating evidence that mitochondria play a key role in NAFLD. Nevertheless, the mitochondrial consequences of steatohepatitis are still unknown. The bioenergetic changes induced in a methionine- and choline-deficient diet (MCDD) model of steatohepatitis were studied in rats. Liver mitochondria from MCDD rats exhibited a higher rate of oxidative phosphorylation with various substrates, a rise in cytochrome oxidase (COX) activity, and an increased content in cytochrome aa3. This higher oxidative activity was associated with a low efficiency of the oxidative phosphorylation (ATP/O, i.e., number of ATP synthesized/natom O consumed). Addition of a low concentration of cyanide, a specific COX inhibitor, restored the efficiency of mitochondria from MCDD rats back to the control level. Furthermore, the relation between respiratory rate and protonmotive force (in the nonphosphorylating state) was shifted to the left in mitochondria from MCDD rats, with or without cyanide. These results indicated that, in MCDD rats, mitochondrial ATP synthesis efficiency was decreased in relation to both proton pump slipping at the COX level and increased proton leak although the relative contribution of each phenomenon could not be discriminated. MCDD mitochondria also showed a low reactive oxygen species production and a high lipid oxidation potential. We conclude that, in MCDD-fed rats, liver mitochondria exhibit an energy wastage that may contribute to limit steatosis and oxidative stress in this model of steatohepatitis.
Mechanisms of Homocysteine-Induced Glomerular Injury and Sclerosis
Authors: Yi Fan , Li Pin-Lan
Published: November 2007

Hyperhomocysteinemia (hHcys) has been recognized as a critical risk or pathogenic factor in the progression of end-stage renal disease (ESRD) and in the development of cardiovascular complications related to ESRD. Recently, evidence is accumulating that hHcys may directly act on glomerular cells to induce glomerular dysfunction and consequent glomerular sclerosis, leading to ESRD. In this review, we summarize recent findings that reveal the contribution of homocysteine as a pathogenic factor to the development of glomerular sclerosis or ESRD. In addition, we discuss several important mechanisms mediating the pathogenic action of homocysteine in the glomeruli or in the kidney, such as lo- cal oxidative stress, endoplasmic reticulum stress, homocysteinylation, and hypomethylation. Understanding these mechanisms may help design new approaches to develop therapeutic strategies for treatment of hHcys-associated end-organ damage and for prevention of deterioration of kidney function and ultimate ESRD in patients with hypertension and diabetes mellitus or even in aged people with hHcys.
Induction of regulatory T cell–resistant helper CD4+ T cells by bacterial vector
Authors: Nishikawa Hiroyoshi , Tsuji Takemasa , Jäger Elke , Briones Gabriel , Ritter Gerd , Old Lloyd J. , Galán Jorge E. , Shiku Hiroshi , Gnjatic Sacha
Published: November 2007

Salmonella typhimurium engineered to deliver cancer/testis antigen NY-ESO-1 through type III secretion (S typhimurium–NY-ESO-1) was shown to be an efficient cancer vaccine construct in mice and to stimulate NY-ESO-1–specific CD8+/CD4+ T cells in vitro in patients with cancer with NY-ESO-1 spontaneous immunity. We also showed that individuals without spontaneous immunity to NY-ESO-1 had specific CD4+ T-cell precursors with high avidity to NY-ESO-1 under tight control by CD4+CD25+ regulatory T (Treg) cells. We now found that in healthy donors and patients with melanoma without NY-ESO-1 spontaneous immunity, S typhimurium–NY-ESO-1 elicits CD4+ T helper 1 (Th1) cells in vitro recognizing naturally processed antigen from these high-avidity NY-ESO-1–specific naive precursors. In contrast to peptide stimulation, induction of specific Th1 cells with S typhimurium–NY-ESO-1 did not require in vitro depletion of CD4+CD25+ Treg cells, and this prevailing effect was partially blocked by disruption of interleukin-6 or glucocorticoid-induced TNF receptor (GITR) signals. Furthermore, S typhimurium–induced Th1 cells had higher GITR expression than peptide-induced Th1 cells and were resistant to suppression by CD4+CD25+ Treg cells in a GITR-dependent fashion. We propose that S typhimurium–NY-ESO-1 induces antigen-specific T-cell responses that are resistant to suppression by CD4+CD25+ Treg cells.
Differential regulation of abundance and deadenylation of maternal transcripts during bovine oocyte maturation in vitro and in vivo
Authors: Thélie Aurore , Papillier Pascal , Pennetier Sophie , Perreau Christine , Traverso Juan Martin , Uzbekova Svetlana , Mermillod Pascal , Joly Catherine , Humblot Patrice , Dalbiès-Tran Rozenn
Published: November 2007

Background

In bovine maturing oocytes and cleavage stage embryos, gene expression is mostly controlled at the post-transcriptional level, through degradation and deadenylation/polyadenylation. We have investigated how post transcriptional control of maternal transcripts was affected during in vitro and in vivo maturation, as a model of differential developmental competence.

Results

Using real time PCR, we have analyzed variation of maternal transcripts, in terms of abundance and polyadenylation, during in vitro or in vivo oocyte maturation and in vitro embryo development. Four genes are characterized here for the first time in bovine: ring finger protein 18 (RNF18) and breast cancer anti-estrogen resistance 4 (BCAR4), whose oocyte preferential expression was not previously reported in any species, as well as Maternal embryonic leucine zipper kinase (MELK) and STELLA. We included three known oocyte marker genes (Maternal antigen that embryos require (MATER), Zygote arrest 1 (ZAR1), NACHT, leucine rich repeat and PYD containing 9 (NALP9)). In addition, we selected transcripts previously identified as differentially regulated during maturation, peroxiredoxin 1 and 2 (PRDX1, PRDX2), inhibitor of DNA binding 2 and 3 (ID2, ID3), cyclin B1 (CCNB1), cell division cycle 2 (CDC2), as well as Aurora A (AURKA). Most transcripts underwent a moderate degradation during maturation. But they displayed sharply contrasted deadenylation patterns that account for variations observed previously by DNA array and correlated with the presence of a putative cytoplasmic polyadenylation element in their 3' untranslated region. Similar variations in abundance and polyadenylation status were observed during in vitro maturation or in vivo maturation, except for PRDX1, that appears as a marker of in vivo maturation. Throughout in vitro development, oocyte restricted transcripts were progressively degraded until the morula stage, except for MELK ; and the corresponding genes remained silent after major embryonic genome activation.

Conclusion

Altogether, our data emphasize the extent of post-transcriptional regulation during oocyte maturation. They do not evidence a general alteration of this phenomenon after in vitro maturation as compared to in vivo maturation, but indicate that some individual messenger RNA can be affected.
Role of insulin-like growth factor binding protein-4 in prevention of colon cancer
Authors: Durai Rajaraman , Yang Shi Y , Seifalian Alexander M , Goldspink Geoffrey , Winslet Marc C
Published: November 2007

Background

Insulin-like growth factors (IGFs) are important for the proliferation of cancer cells. One of their binding proteins, known as insulin-like growth factor binding protein -4 (IGFBP-4) is well known for its inhibitory action on IGFs in vitro. We assessed the effect of IGFBP-4 in prevention of development of colon cancer in vivo.

Methods

Nude mice were subcutaneously inoculated with HT-29 colon cancer cells and they were also simultaneously injected either gene construct containing mammalian expression vector pcDNA3 with or without IGFBP-4 gene or phosphate buffered saline. The effect was assessed 4 weeks later by evaluating the tumours for mitosis, necrosis, apoptosis, and expressions of IGFBP-4, Bcl-2 and Bax proteins.

Results

The results showed that the IGFBP-4 gene therapy did not prevent the tumour establishment but it increased the tumour apoptosis which was associated with an increase in Bcl-2 and Bax expressions. The IGFBP-4 protein was low in tumours which received IGFBP-4 gene construct which may be due to a feed back mechanism of IGFBP-4 upon its own cells.

Conclusion

IGFBP-4 gene therapy in the form localised gene transfer did not prevent colon cancer initiation and establishment but it resulted in increased apoptosis and Bax protein expression and a decrease in tumour cellular mitosis
Direct observation of hematopoietic progenitor chimerism in fetal freemartin cattle
Authors: Niku Mikael , Pessa-Morikawa Tiina , Taponen Juhani , Iivanainen Antti
Published: November 2007

Background

Cattle twins are well known as blood chimeras. However, chimerism in the actual hematopoietic progenitor compartment has not been directly investigated. Here, we analyzed fetal liver of chimeric freemartin cattle by combining a new anti-bovine CD34 antibody and Y-chromosome specific in situ hybridization.

Results

Bull-derived CD34+ cells were detected in the liver of the female sibling (freemartin) at 60 days gestation. The level of bull-derived CD34+ cells was lower in the freemartin than in its male siblings. Bull (Y+) and cow hematopoietic cells often occurred in separate clusters. Around clusters of Y+CD34+ cells, Y+CD34- cells were typically observed. The thymi were also strongly chimeric at 60 days of gestation.

Conclusion

The fetal freemartin liver contains clusters of bull-derived hematopoietic progenitors, suggesting clonal expansion and differentiation. Even the roots of the hematopoietic system in cattle twins are thus strongly chimeric from the early stages of fetal development. However, the hematopoietic seeding of fetal liver apparently started already before the onset of functional vascular anastomosis.
Decursin and decursinol angelate inhibit estrogen-stimulated and estrogen-independent growth and survival of breast cancer cells
Authors: Jiang Cheng , Guo Junming , Wang Zhe , Xiao Bingxiu , Lee Hyo-Jung , Lee Eun-Ok , Kim Sung-Hoon , Lu Junxuan
Published: November 2007

Introduction

Estrogen and estrogen receptor (ER)-mediated signaling are crucial for the etiology and progression of human breast cancer. Attenuating ER activities by natural products is a promising strategy to decrease breast cancer risk. We recently discovered that the pyranocoumarin compound decursin and its isomer decursinol angelate (DA) have potent novel antiandrogen receptor signaling activities. Because the ER and the androgen receptor belong to the steroid receptor superfamily, we examined whether these compounds affected ER expression and signaling in breast cancer cells.

Methods

We treated estrogen-dependent MCF-7 and estrogen-independent MDA MB-231 human breast cancer cells with decursin and DA, and examined cell growth, apoptosis, and ERα and ERβ expression in both cell lines – and, in particular, estrogen-stimulated signaling in the MCF-7 cells. We compared these compounds with decursinol to determine their structure-activity relationship.

Results

Decursin and DA exerted growth inhibitory effects on MCF-7 cells through G1 arrest and caspase-mediated apoptosis. These compounds decreased ERα in MCF-7 cells at both mRNA and protein levels, and suppressed estrogen-stimulated genes. Decursin and the pure antiestrogen Faslodex™ exerted an additive growth inhibitory effect on MCF-7 cells. In MDA MB-231 cells, these compounds induced cell-cycle arrests in the G1 and G2 phases as well as inducing apoptosis, accompanied by an increased expression of ERβ. In contrast, decursinol, which lacks the side chain of decursin and DA, did not have these cellular and molecular activities at comparable concentrations.

Conclusion

The side chain of decursin and DA is crucial for their anti-ER signaling and breast cancer growth inhibitory activities. These data provide mechanistic rationales for validating the chemopreventive and therapeutic efficacy of decursin and its derivatives in preclinical animal models of breast cancer.