bluuebunny/crossref_metadata_2025 huggingface dataset:
Recrystallization in different sunscreen formulations after cutaneous application
Authors: Toskić‐Radojiči´ M D , Pavlović M D , Kovačević A , Milosavljević I
Published: December 2004

Background  Data on the structure of sunscreens prior to and after application to the skin and the possible impact of these factors on their efficacy are still scant.

Aims  The microscopic structure of several commercial sunscreen products containing benzophenone‐3 (BP‐3) was analysed under a light microscope, prior to and 2 h after application of the products to the skin, and compared with various control preparations with or without BP‐3.

Methods  All tested formulations were mounted on microscope slides, viewed under a light microscope and photographed. Samples were taken directly from original packages or from freshly prepared prescription formulations. Two hours after application to the skin, the samples were taken and processed for microscopy.

Results  In some commercial sunscreens numerous crystals were formed upon cutaneous application, whereas others contained crystals both prior to and after epicutaneous application. A single commercial product (a lamellar ambiphyl emulsion, SPF28) retained its regular structure throughout the study. Control preparations with or without BP‐3 and/or octyl methoxycinnamate contained crystals after cutaneous application.

Conclusions  Ingredients, most probably BP‐3, in many commercial sunscreens are prone to recrystallization while on the skin which might interfere with their UV light‐absorbing function.
Brittle nails
Authors: Iorizzo M , Pazzaglia M , M Piraccini B , Tullo S , Tosti A
Published: December 2004

Nail brittleness is a common complaint characterized by weak inelastic nails that split, flake and crumble. It may be a consequence of factors that alter nail plate production and/or factors that damage the already keratinised nail plate. It is often idiopathic. It can also be caused by many dermatological and systemic diseases, nutritional deficiencies, drugs and traumas. Environmental and occupational factors that produce progressive dehydration of the nail plate have an important role in nail brittleness.

Treatment of brittle nails is often difficult. Preventative measures, together with oral supplementation of vitamins (especially biotin), oligo‐elements and amino acids, can be useful in improving nail strength. Cosmetic treatment affords camouflage and a degree of protection.
Traumatic nail split
Authors: Aljabre Salih Hamad Mohamad , Hejazi Mohamad , Alamir Ali
Published: December 2004

In nail split, the nail plate is divided into two parts. Trauma involving the nail matrix, the generator of the nail plate, can result in nail plate splitting which may take some months to become apparent. Photographic documentation of this condition in the literature had hitherto been lacking.
Consumption, Wealth and Expected Stock Returns in Australia*
Authors: FISHER LANCE A. , VOSS GRAHAM M.
Published: December 2004

The present paper investigates the relationship between consumption, labour income and household wealth in Australia within the inter‐temporal consumption framework developed by Lettau and Ludvigson (2001). We first test for a long‐run relationship among these series and then investigate whether private dissaving, measured as the deviation from the estimated relationship, has information content for future stock returns. We find that private dissaving has predictive power for quarterly returns on the ASX200 and for returns over long holding periods. The recent substantial decline in private dissaving suggests that consumers view the recent surge in non‐financial wealth as transitory and expect a correction.
HIV Knowledge and Practices Among Rural South Africans
Authors: Mabunda Gladys
Published: December 2004

Purpose

: To explore the knowledge and practices related to HIV/AIDS by rural South Africans in Limpopo Province.

Design and Methods

: Qualitative research methods were used. Twenty‐eight key and general informants participated in individual interviews in summer 2001. The setting was a hospital‐based HIV clinic in rural Limpopo Province.

Findings

: All participants were members of a support group, and they had basic knowledge about HIV/AIDS; however, participants indicated that they lacked basic knowledge of HIV/AIDS until they joined the support group.

Conclusions

: Support groups were effective in educating people about HIV/AIDS.
Effect of a Low‐Cost Intervention on Recording Body Mass Index in Patients' Records
Authors: Lemay Celeste A. , Cashman Suzanne B. , Savageau Judith A. , Reidy Patricia A.
Published: December 2004

Purpose

: Evaluate the effectiveness of body mass index (BMI) tables placed in exam rooms as an intervention to encourage providers to calculate and record BMI scores in patients' medical records.

Design

: In a prospective cohort design, medical record data for 276 adult patients at a federally funded community health center in New England were examined from August 2000 to August 2002 following the intervention.

Methods

: Prominent, multicolored, laminated BMI tables were posted in the exam rooms of one of the study site's three primary health care teams. Medical record data collected included documentation of BMI calculation in medical records, documentation of an obesity diagnosis, and inclusion of heights and current weights. Frequency distributions were calculated; chi‐square tests were used to identify associations.

Findings

: In contrast to the comparison teams, patients on the intervention team were more likely to have BMI recorded in the medical record. A statistically significant increase in the diagnosis of obesity was observed throughout the health center after the intervention.

Conclusions

: Posting BMI tables in exam rooms contributed to increased BMI documentation in patients' medical records.
Loneliness, Depression, and Social Support of Turkish Patients With Chronic Obstructive Pulmonary Disease and Their Spouses
Authors: Kara Magfiret , Mirici Arzu
Published: December 2004

Purpose

: To identify the differences in loneliness, depression, and social support among Turkish patients with COPD and their spouses.

Design

: The convenience sample consisted of 30 patients with COPD and their spouses. Descriptive statistics, Student's t tests, and Pearson product moment correlations were used to analyse the data.

Methods

: Data were collected during structured interviews in an outpatient clinic in Turkey by using the UCLA Loneliness Scale, the Beck Depression Inventory and Perceived Social Support from Friends and Family scales.

Findings

: Levels of loneliness, depression, and perceived social support from family and friends were similar for patients and spouses. Loneliness and depression were positively related, but both loneliness and depression were greater with less perceived social support from family and friends for both patients and their spouses.

Conclusions

: Patients' and spouses' psychologic reactions to COPD might include feelings of loneliness and depression, which might be alleviated by social support.
Negative Thinking and the Mental Health of Low‐Income Single Mothers
Authors: Peden Ann R. , Rayens Mary Kay , Hall Lynne A. , Grant Elizabeth
Published: December 2004

Purpose:

To test a conceptual model of predictors of depressive symptoms in low‐income single mothers with children from 2 to 6 years of age.

Design:

Data were collected from September 2000 to October 2002 as part of the baseline data collection for a larger study in the eastern part of the United States. A volunteer sample of 205 women who were at risk for depression was recruited.

Methods:

Each woman completed a survey that included the Center for Epidemiologic Studies—Depression Scale, the Beck Depression Inventory, the Rosenberg Self‐Esteem Scale, the Crandall Cognitions Inventory, and the Everyday Stressors Index.

Findings:

More than 75% of the participants scored at least in the mild depressive range on the Beck Depression Inventory or in the high depressive range on the CES‐D. Negative thinking mediated the relationship between self‐esteem and depressive symptoms and partially mediated the relationship between chronic stressors and depressive symptoms.

Conclusions:

These findings are consistent with earlier research by this team. Negative thinking is an important factor in the development of depressive symptoms in at‐risk women. As a symptom, negative thinking might be more amenable to nursing intervention than to interventions focused on reducing chronic stress.
Sympathetic neural inhibition of conducted vasodilatation along hamster feed arteries: complementary effects of α1‐ and α2‐adrenoreceptor activation
Authors: Haug Sara J. , Segal Steven S.
Published: December 2004

Vasodilatation initiated on arterioles of skeletal muscle ascends into the proximal feed arteries through cell‐to‐cell conduction along the endothelium and into smooth muscle. Whereas perivascular sympathetic nerve activity (SNA) can inhibit conducted vasodilatation and restrict muscle blood flow, the signalling events mediating this interaction are poorly defined. Therefore, using isolated pressurized (75 mmHg) feed arteries (diameter (μm) at rest = 53 ± 3; maximum = 99 ± 2; n= 86) of the hamster retractor muscle, we tested the hypothesis that distinct yet complementary signalling pathways underlie the ability of SNA to inhibit conduction. Conducted vasodilatation was initiated using ACh microiontophoresis (1 μA; 250, 500 and 1000 ms) and SNA was initiated using local field stimulation (30–50 V; 1 ms at 2, 8 and 16 Hz). With vasodilatations of 5–20 μm, conduction increased with ACh pulse duration and was inhibited progressively as the frequency of SNA increased. During SNA, conduction was partially restored with inhibition of α1‐ (0.1 μm prazosin) or α2‐ (0.1 μm RX821002) adrenoreceptors and fully restored with both antagonists present. Activating α1‐ (50 nm phenylephrine) or α2‐ (1 μm UK 14,304) adrenoreceptors inhibited conduction partially and their simultaneous activation inhibited conduction cumulatively (P < 0.05). Elevated [K+]o (30 or 40 mm) or phorbol esters (0.5 μm) also inhibited conduction yet similar constriction with l‐NNA (50 μm) or Bay K 8644 (10 nm) did not. Thus, the activation of α1‐ and α2‐adrenoreceptors inhibits conducted vasodilatation through complementary signalling events. With robust coupling along the endothelium, our modelling predicts that the inhibition of conduction by SNA can be explained by reduced electrical coupling through myoendothelial gap junctions or greater current leak across smooth muscle cell membranes.
Functional properties and pharmacological inhibition of ASIC channels in the human SJ‐RH30 skeletal muscle cell line
Authors: Gitterman D. P. , Wilson J. , Randall A. D.
Published: December 2004

The rhabdomyosarcoma cell line (SJ‐RH30) exhibits both ultrastructural and electrophysiological hallmarks of mammalian skeletal muscle. We have used patch‐clamp electrophysiology to study acid‐gated currents in these cells. At a holding potential of −60 mV, rapid application of extracellular solutions of pH 6.5 produced inward current responses in ∼85% of cells. The amplitude of these responses exhibited a marked pH dependence. In addition, the kinetics of both activation and desensitization were faster at more acidic pH, whereas the deactivation rate was pH independent. Repeated applications of a pH 6.0 solution produced a tachyphalaxis that could be substantially attenuated by reducing the duration of the acid challenge and increasing the interstimulus interval. The current–voltage relationship of the acid‐induced currents was linear at positive potentials but an area of negative slope conductance was observed in the negative potential range. This was not eliminated by removal of extracellular Ca2+, a manoeuvre which did, however, substantially increase current amplitude. Changing the transmembrane Na+ gradient altered the current–voltage relationship in a fashion commensurate with an underlying conductance predominantly permeable to Na+. Pharmacologically, acid‐induced currents were blocked 84.4 ± 1.2% by 30 μm amiloride and 91.8 ± 3.0% by a 1 : 1000 dilution of Psalmopoeuscambridgei venom. Inhibition by both agents could be reversed by a short period of compound washout. By contrast, APETx2 had no significant effect on acid‐evoked currents. These observations strongly suggest the acid‐induced current is mediated by ASIC1 channels. In agreement with this, current responses of SJ‐RH30 cells to a pH 6.0 challenge were greatly enhanced by extracellular lactate. These data demonstrate the presence of ASIC1 channels in a cell line with skeletal muscle characteristics. In addition, significant levels of ASIC1 and ASIC3 mRNA were found in skeletal muscle tissue samples. These findings are discussed with regard to the role such a conductance might play if present in skeletal muscle in vivo.
Impaired synaptic scaling in mouse hippocampal neurones expressing NMDA receptors with reduced calcium permeability
Authors: Pawlak Verena , Schupp Bettina J. , Single Frank N. , Seeburg Peter H. , Köhr Georg
Published: December 2004

NMDA receptors (NMDARs) play a crucial role for the acquisition of functional AMPARs during Hebbian synaptic plasticity at cortical and hippocampal synapses over a short timescale of seconds to minutes. In contrast, homeostatic synaptic plasticity can occur over longer timescales of hours to days. The induction mechanisms of this activity‐dependent synaptic scaling are poorly understood but are assumed to be independent of NMDAR signalling in the cortex. Here we investigated in the hippocampus a potential role of NMDAR‐mediated Ca2+ influx for synaptic scaling of AMPA currents by genetic means. The Ca2+ permeability of NMDARs was reduced by selective postnatal expression in principal neurones of mouse forebrain half of the NR1 subunits with an amino acid substitution at the critical channel site (N598R). This genetic manipulation did not reduce the total charge transfer via NMDARs in nucleated patches (somatic) and at synaptic sites. In contrast, the current amplitude and the charge carried through AMPARs were substantially reduced at somatic and synaptic sites in juvenile and adult mutants, indicating persistent downscaling of AMPA responses. Smaller and less frequent AMPA miniature currents in the mutant demonstrated a postsynaptic locus of this down‐regulation. Afferent innervation and release probability were unchanged at CA3‐to‐CA1 synapses of mutants, as judged from input‐output and minimal stimulation experiments. Our results indicate that NMDAR‐mediated Ca2+ signalling is important for synaptic scaling of AMPA currents in the hippocampus in vivo.
Adaptive Air Charge Estimation for Turbocharged Diesel Engines Without Exhaust Gas Recirculation
Authors: Storset Ove F. , Stefanopoulou Anna G. , Smith Roy
Published: December 2004

The paper presents an adaptive observer for in-cylinder air charge estimation for turbocharged diesel engines without exhaust gas recirculation (EGR). We assess the observability of the mean value engine model when the intake manifold pressure and the compressor flow are measured, and the performance of the observer is compared to existing schemes analytically and with limited simulations. Specifically, it is shown that the designed observer performs better than the conventional schemes during fast step changes in engine fueling level, eventhough it uses a simple but time varying parameterization of the volumetric efficiency. Furthermore, the estimate is less sensitive to changes in engine parameters than the existing schemes.
Feedback Control of Thermal Systems Modeled via the Network Approach
Authors: Papalexandris Miltiadis V.
Published: December 2004

This article reports on feedback control algorithms for thermal systems modeled via the network approach. These networks belong to the class of descriptor systems. They are subject to nondecaying disturbances and, therefore, integral action is required for zero offset. The article includes the derivation of optimal integral controllers for general linear descriptor systems and a detailed study on decentralized control for thermal networks. Feasibility of decentralized control is established via two theorems regarding stability and decentralized integral controllability of thermal networks. Additionally, a particular strategy for the synthesis of decentralized controllers is proposed. This article concludes with a sample of the numerical tests that we performed to demonstrate the efficiency of the proposed algorithms.
Adaptive Control of Mechanical Systems With Time-Varying Parameters and Disturbances
Authors: Pagilla Prabhakar R. , Zhu Yongliang
Published: December 2004

A new adaptive control algorithm for mechanical systems with time-varying parameters and/or time-varying disturbances is proposed and investigated. The proposed method does not assume any structure to the time-varying parameter or disturbance. The method is based on the expansion of the time-varying parameter/disturbance using Taylor’s formula. This facilitates expanding a time-varying function as a finite length polynomial and a bounded residue. The coefficients of the finite-length polynomial are estimated in a small time interval so that they can be assumed to be constant within that interval. A gradient projection algorithm is used to estimate the parameters within each time interval. Stability of the proposed adaptive controller is shown and discussed. A novel experiment is designed using a two-link planar mechanical manipulator to investigate the proposed algorithm experimentally. Results of the proposed adaptive controller are compared with an ideal nonadaptive controller that assumes complete knowledge of the parameters and disturbances. A representative sample of the experimental results is shown and discussed.
Simulation of Longitudinal Impact Waves Using Time Delayed Systems
Authors: Hu and Bin , Eberhard Peter
Published: December 2004

In this paper, it is shown that some classic longitudinal impact problems can be solved satisfactorily with time delayed systems. As an example, a sphere colliding with a fixed rod with finite length is discussed in detail. Since it takes a finite time for a wave propagating from one position to another position, the longitudinal impact wave is naturally modeled by a time delay system. Numerical simulation shows some interesting phenomena and experimental results have validated the model with time delay. It is shown that for the computation of Poisson’s coefficient of restitution in multibody dynamics, the decomposition of the contact into the compression phase and the expansion phase must either be specified by whether the contact force increases or decrease or by whether the relative displacement increases or decreases. In the first case, the coefficient of restitution determined from the time history of the contact force could be greater than one. In the other case, the duration of contact determined from the relative displacement of the colliding bodies may be wrong as discussed in the paper.
Introducing Glory: A Novel Strategy for an Omnidirectional Spherical Rolling Robot
Authors: Javadi A. Amir Homayoun , Mojabi Puyan
Published: December 2004

This paper describes a prototype and analytical studies of a spherical rolling robot, a new design of an omnidirectional robot system. The robot can arbitrarily begin to move in any direction to the target, and autonomously roll and reach any desired position. Our design has considered a spherical robot with an internal mechanism for propulsion. The propulsion mechanism will distribute weights radially along spokes fixed inside the sphere and enables the robot to accelerate, decelerate, and move with constant velocity. A mathematical model of the robot’s dynamic and motion was instructed. An algorithmic motion planning is developed and, partly, pseudocode of that is presented. For a number of missions, it is shown experimentally that the model agrees well with the results.
Measurement of Whole-Field Surface Displacements and Strain Using a Genetic Algorithm Based Intelligent Image Correlation Method
Authors: Pilch Alan , Mahajan Ajay , Chu Tsuchin
Published: December 2004

This paper presents an intelligent digital image correlation technique that uses genetic algorithms to measure surface displacements and strains. Speckle patterns are spray painted on the surface of interest and pictures taken before and during loading. Subpixel resolution, required for measuring displacements and strains accurately, is obtained by using interpolation methods. An innovative procedure based on genetic algorithms (GA) is used that has the potential to give the two displacements and four deformation gradients directly for a subset being investigated. This paper presents the algorithm for the six variables, but uses only the displacements (two variables) to calculate the 2-D strain fields. The genetic algorithms can guarantee a solution based on a comprehensive calibration procedure. The focus of this paper is the description of the GA routine used for the search process as well as the calibration scheme. Measurement results are presented for rigid-body displacement, 1-D and 2-D strain as proof of concept. Some potential applications for this work are to extract surface displacements and strains on the surfaces of aircraft, spacecraft and reusable launch vehicles, submarine and ship hulls, civil infrastructures such as bridges, dams and buildings, and biomedical imaging applications.
Nonlinear Optimal Internal Forces Control and Application to Swing-Up and Stabilization of Pendulum
Authors: Suzuki Satoshi , Furuta Katsuhisa , Sugiki Akihiko , Hatakeyama Shoshiro
Published: December 2004

Internal forces are brought by the connection of a multilink mechanism as integrated effects of constraint forces at joints, centrifugal/Coriolis forces, and external forces. In this paper, in order to enhance a performance in the stabilization of the total system, the internal forces are considered to be reduced by the nonlinear regulation based on a State-Dependent Riccati Equation (SDRE), where the internal forces are derived by a projection method. The dynamics of individual components and the relations of the constraint motions yield the dynamic model of whole system. Considering a criterion function of which integrands consist of the conventional quadratic forms with the state-dependent weighting matrices, a nonlinear optimal control law for the criterion function, named nonlinear state-dependent controller, is determined by solving the SDRE in real time. As the results of the proposed control, system’s mechanical components would not receive large internal forces and the control performance has been improved. The proposed method is effectively demonstrated by an experiment of a global stabilization control of the 1-link Furuta pendulum at the upright position.
Discrete Fuzzy Controller Design for Achieving Common State Covariance Assignment
Authors: Chang Wen-Jer , Shing Chong-Cheng
Published: December 2004

In this paper, a method is developed to find the output feedback fuzzy controllers for assigning a common state covariance matrix of discrete Takagi–Sugeno (T–S) fuzzy systems. The fuzzy control approach developed in this paper is based on the concept of Parallel Distributed Compensation (PDC). For each rule of the discrete T–S fuzzy model, it shows how to parameterize the static linear output feedback control gains to achieve a common state covariance matrix for each subsystem. Finally, a numerical example is provided to verify the effects of the proposed method.
A Frequency-Adaptive Multi-Objective Suspension Control Strategy
Authors: Lu Jianbo
Published: December 2004

This paper studies a new FAMOS strategy for suspension control. FAMOS stands for frequency-adaptive multi-objective suspension. This strategy adjusts the control law based on certain frequency information and achieves a balanced ride and handling performance. It contains a road profile identifier, several multi-objective control laws which optimize a mixed H2/H∞ performance index based on different performance preferences, and an adaptive law based on the frequency contents estimated from the identified road profile. The strategy is applied to a quarter car suspension control and the simulation results show that the achieved performance is better than many existing results.
Deep vein thrombosis after total hip and knee arthroplasty in Indian patients
Authors: Jain V , Dhaon B K , Jaiswal A , Nigam V , Singla J
Published: December 2004

Background: Deep vein thrombosis (DVT) is one of the most common complications of total hip (THA) and total knee arthroplasty (TKA). Though the reported incidence of DVT is very high, that of proximal DVT is low and that of fatal thromboembolism is very low. Hence the issue of prophylaxis for DVT remains controversial.

The incidence of DVT is based on various studies in European and American populations. The Asian population is genetically and socially quite different from American and European populations, and the incidence of DVT can be quite different. Therefore a prospective study was initiated at our centre to determine incidence of DVT after THA and TKA in Indian patients.

Methods: A prospective study was conducted on 60 hips in 45 patients and 46 knees in 26 patients who underwent THA and TKA respectively, without any known risk factors for thromboembolic disease. DVT was studied by preoperative and postoperative serial colour Doppler ultrasonography. No prophylaxis was given to any of the patients.

Results: DVT was found in two patients who had undergone THA. No case of DVT was detected in any patient who had undergone TKA.

Conclusion: These results suggest that the incidence of DVT in Indian patients is very low and is not comparable with American and European populations. It is therefore not cost effective to advise prophylaxis in Indian patients undergoing THA/TKA who have no known risk factors for DVT.
Update on myasthenia gravis
Authors: Thanvi B R , Lo T C N
Published: December 2004

Myasthenia gravis is an autoimmune disorder caused by autoantibodies against the nicotinic acetylcholine receptor on the postsynaptic membrane at the neuromuscular junction and characterised by weakness and fatigability of the voluntary muscles. It has a bimodal peak of incidence with first peak in the third decade and the second peak in the sixth decade. It is probably underdiagnosed in the very old population. Our understanding of the pathogenesis, immunology, and molecular biology of myasthenia gravis has greatly improved in last three decades. It is almost always possible to establish the diagnosis of myasthenia gravis with the current tests. The modern treatment is highly successful and the mortality of treated myasthenia gravis is practically zero. However, there are still important gaps in our knowledge of the origin of myasthenia gravis, the factors that contribute to chronic disease, and the way to cure the disease. In this article the current knowledge of the various aspects of myasthenia gravis are outlined.
Gastro-oesophageal reflux and bronchial asthma: current status and future directions
Authors: Mathew J L , Singh M , Mittal S K
Published: December 2004

In recent years there have been several reports suggesting an association between bronchial asthma and gastro-oesophageal reflux; however a cause and effect relationship has not been proven yet. Confirmation of such a relationship is likely to have far reaching implications on the management of asthma. Reliable assessment of this issue is hampered by the presence of various lacunae in most of the published studies. Hence it is essential to carefully examine the strength of data suggesting a link between asthma and reflux. This article critically analyses currently available literature on the subject (including published reviews, meta-analyses, and randomised clinical trials in the English language) and summarises valid conclusions that can be drawn; it also proposes a framework for future studies to resolve the issue.
Communication skills training in postgraduate medicine: the development of a new course
Authors: Dacre J , Richardson J , Noble L , Stephens K , Parker N
Published: December 2004

It has long been accepted that communication is of central importance in healthcare, and a core aspect of clinical competence. Many educational institutions and Royal Colleges now reflect this and consider communication skills a priority in postgraduate examination. The new examination “Practical Assessment of Clinical and Examination Skills” has replaced the Royal College of Physicians MRCP part 2 clinical and oral examination. This examination now consists of five clinical stations, two of which focus on communication skills. A short course for postgraduate trainees has been designed to address the communication skills requirements of the part 2 clinical examination. The aims, development, and content of the course are described. Emphasis is placed on candidates practising skills with patients and receiving feedback during the course. Evidence suggests that practice with feedback is an essential ingredient of communication skills courses, and is more effective than other methods such as observing experts or video examples, or simply discussing issues in communication. Results of a preliminary evaluation indicate that the course was perceived as valuable by candidates and that the aims, format, and content were appropriate. Although the preliminary evaluation was largely positive, it could be argued that the acid test of the effectiveness of a course is an objective evaluation of skills, observed before and after the course, a development that is being considered for future evaluation of the course. Recommendations for applying this type of training to postgraduate trainees in any branch of medicine are given.
Left over bowels: an unique complication in a surviving twin
Authors: George A T , Varkey S , Kalam A , Surendran N
Published: December 2004

Conjoint twins have always been a surgical challenge. The authors report an unusual finding in a surviving epigastric heteropagus twin. A 17 year old boy who underwent laparotomy for acute intestinal obstruction revealed a blind ending but complete duplication of the large bowel and an accessory liver in the falciform ligament, along with a separate gall bladder but with fused bile ducts.

The findings suggest that the duplicated bowel loop and the accessory liver were remnants of the incomplete parasite twin, assimilated into the body of the autosite, which remained asymptomatic for 17 years. This case is being reported because of the uniqueness of the finding.
A Γ-CONVERGENCE APPROACH TO NON-PERIODIC HOMOGENIZATION OF STRONGLY ANISOTROPIC FUNCTIONALS
Authors: BALDI ANNALISA , TESI MARIA CARLA
Published: December 2004

In this work we present a homogenization result for a class of degenerate elliptic functionals mimicking strongly anisotropic media. We study the limit as ε→0 of the functionals [Formula: see text] where, for any ε>0, αε:ℝn×ℝn→ℝ, αε(x,ξ)≈p/2-1, Aε∈Mn×n(ℝ) being measurable non-negative matrices such that [Formula: see text] almost everywhere, p>1. To take into account the anisotropy of the media we consider two families of weight functions reasonably different, λε and Λε, possibly degenerate or singular, such that: [Formula: see text] The convergence to the homogenized problem is obtained by a classical approach of Γ-convergence.
FROM BLOCH MODEL TO THE RATE EQUATIONS II: THE CASE OF ALMOST DEGENERATE ENERGY LEVELS
Authors: BIDÉGARAY-FESQUET B. , CASTELLA F. , DUMAS E. , GISCLON M.
Published: December 2004

Bloch equations give a quantum description of the coupling between atoms and a driving electric force. It is commonly used in optics to describe the interaction of a laser beam with a sample of atoms. In this paper, we address the asymptotics of these equations for a high frequency electric field, in a weak coupling regime. The electric forcing is taken quasiperiodic in time.

We prove the convergence towards a rate equation, i.e. a linear Boltzmann equation, recovering in this way the physically relevant asymptotic model. It describes the transitions amongst the various energy levels of the atoms, governed by the resonances between the electric forcing and the atoms' eigenfrequencies. We also give the explicit value for the transition rates.

The present task has already been addressed in Ref. 5 in the case when the energy levels are fixed, and for different classes of electric fields. Here, we extend the study in two directions. First, we consider almost degenerate energy levels, a natural situation in practice. In this case, almost resonances might occur. Technically, this implies that the small divisor estimates needed in Ref. 5 are false, due to the fact that the Diophantine condition is unstable with respect to small perturbations. We use an appropriate ultraviolet cutoff to restore the analysis and to sort out the asymptotically relevant frequencies. Second, since the asymptotic rate equation may be singular in time, we completely analyze the initial time-layer, as well as the associated convergence towards an equilibrium state.
REGULARIZATION BY MONOTONE PERTURBATIONS OF THE HYDROSTATIC APPROXIMATION OF NAVIER–STOKES EQUATIONS
Authors: ORTEGÓN GALLEGO FRANCISCO
Published: December 2004

Due to the lack of regularity of the solutions to the hydrostatic approximation of Navier–Stokes equations, an energy identity cannot be deduced. By including certain nonlinear perturbations to the hydrostatic approximation equations, the solutions to the perturbed problem are smooth enough so that they satisfy the corresponding energy identity. The perturbations considered in this paper are of the monotone class. Three kinds of problems are then studied. To do that, we introduce a functional setting and show in every case that the set of smooth functions with compact support is dense in the space where we search for solutions. When the perturbations are small enough in a certain sense, the solutions of the perturbed problem are close to those of the original one. As a result, this gives a new proof of the existence of solutions to the hydrostatic approximation of Navier–Stokes equations. Finally, this regularization technique has been applied to the analysis of a one-equation hydrostatic turbulence model.
A CHARACTERIZATION OF SECOND-ORDER DIFFERENTIAL OPERATORS ON FINITE ELEMENT SPACES
Authors: CHRISTIANSEN SNORRE H.
Published: December 2004

We describe all operators on scalar finite element spaces which appear as the restriction of a second-order (linear) differential operator. More precisely we provide a family of isomorphisms between this space of discrete differential operators and products of some exotic finite element spaces. This provides a unified framework for the Regge calculus of numerical relativity and the Nédélec edge elements of computational electromagnetism.
PROPOSITIONS OF FIVE EQUILIBRIA EXAMPLES FOR 3×2 CES/LES PURE EXCHANGE ECONOMIES
Authors: HUANG HUI , ZHANG SHUNMING
Published: December 2004

This paper reports numerical examples for a 3 individual 2 good CES/LES pure exchange economy in which 5 equilibria exist. We explore the size of the regions of the parameter space for which 5 equilibria persist, and show these ranges to be very small in each parameter. Other features of the equilibrium manifolds are examined. The number of equilibria can jump from 5 to 3 to 1, or even from 5 to 1. We also find changes of (Kehoe) equilibrium indices from -1 to +1 or from +1 to -1. Then, we provide parameter changes simultaneously in a large range that preserve given 5 equilibria.
MODELING AND SIMULATION OF MOLECULAR BIOLOGY SYSTEMS USING PETRI NETS: MODELING GOALS OF VARIOUS APPROACHES
Authors: HARDY SIMON , ROBILLARD PIERRE N.
Published: December 2004

Petri nets are a discrete event simulation approach developed for system representation, in particular for their concurrency and synchronization properties. Various extensions to the original theory of Petri nets have been used for modeling molecular biology systems and metabolic networks. These extensions are stochastic, colored, hybrid and functional. This paper carries out an initial review of the various modeling approaches based on Petri net found in the literature, and of the biological systems that have been successfully modeled with these approaches. Moreover, the modeling goals and possibilities of qualitative analysis and system simulation of each approach are discussed.
IDENTIFYING UNIFORMLY MUTATED SEGMENTS WITHIN REPEATS
Authors: SAHINALP S. CENK , EICHLER EVAN , GOLDBERG PAUL , BERENBRINK PETRA , FRIEDETZKY TOM , ERGUN FUNDA
Published: December 2004

Given a long string of characters from a constant size alphabet we present an algorithm to determine whether its characters have been generated by a single i.i.d. random source. More specifically, consider all possible n-coin models for generating a binary string S, where each bit of S is generated via an independent toss of one of the n coins in the model. The choice of which coin to toss is decided by a random walk on the set of coins where the probability of a coin change is much lower than the probability of using the same coin repeatedly. We present a procedure to evaluate the likelihood of a n-coin model for given S, subject a uniform prior distribution over the parameters of the model (that represent mutation rates and probabilities of copying events). In the absence of detailed prior knowledge of these parameters, the algorithm can be used to determine whether the a posteriori probability for n=1 is higher than for any other n>1. Our algorithm runs in time O(ℓ4log ℓ), where ℓ is the length of S, through a dynamic programming approach which exploits the assumed convexity of the a posteriori probability for n.

Our test can be used in the analysis of long alignments between pairs of genomic sequences in a number of ways. For example, functional regions in genome sequences exhibit much lower mutation rates than non-functional regions. Because our test provides means for determining variations in the mutation rate, it may be used to distinguish functional regions from non-functional ones. Another application is in determining whether two highly similar, thus evolutionarily related, genome segments are the result of a single copy event or of a complex series of copy events. This is particularly an issue in evolutionary studies of genome regions rich with repeat segments (especially tandemly repeated segments).
ROBUSTNESS, STABILITY AND EFFICIENCY OF PHAGE λ GENETIC SWITCH: DYNAMICAL STRUCTURE ANALYSIS
Authors: ZHU X.-M. , YIN L. , HOOD L. , AO P.
Published: December 2004

Based on the dynamical structure theory for complex networks recently developed by one of us and on the physical-chemical models for gene regulation, developed by Shea and Ackers in the 1980's, we formulate a direct and concise mathematical framework for the genetic switch controlling phage λ life cycles, which naturally includes the stochastic effect. The dynamical structure theory states that the dynamics of a complex network is determined by its four elementary components: The dissipation (analogous to degradation), the stochastic force, the driving force determined by a potential, and the transverse force. The potential may be interpreted as a landscape for the phage development in terms of attractive basins, saddle points, peaks and valleys. The dissipation gives rise to the adaptivity of the phage in the landscape defined by the potential: The phage always has the tendency to approach the bottom of the nearby attractive basin. The transverse force tends to keep the network on the equal-potential contour of the landscape. The stochastic fluctuation gives the phage the ability to search around the potential landscape by passing through saddle points.

With molecular parameters in our model fixed primarily by the experimental data on wild-type phage and supplemented by data on one mutant, our calculated results on mutants agree quantitatively with the available experimental observations on other mutants for protein number, lysogenization frequency, and a lysis frequency in lysogen culture. The calculation reproduces the observed robustness of the phage λ genetic switch. This is the first mathematical description that successfully represents such a wide variety of major experimental phenomena. Specifically, we find: (1) The explanation for both the stability and the efficiency of phage λ genetic switch is the exponential dependence of saddle point crossing rate on potential barrier height, a result of the stochastic motion in a landscape; and (2) The positive feedback of cI repressor gene transcription, enhanced by the CI dimer cooperative binding, is the key to the robustness of the phage λ genetic switch against mutations and fluctuations in kinetic parameter values.
A TUTORIAL OF RECENT DEVELOPMENTS IN THE SEEDING OF LOCAL ALIGNMENT
Authors: BROWN DANIEL G. , LI MING , MA BIN
Published: December 2004

We review recent results on local alignment. We begin with a review of classical methods and early heuristic methods, and then focus on more recent work on the seeding of local alignment. We show that these techniques give a vast improvement in both sensitivity and specificity over previous methods, and can achieve sensitivity at the level of classical algorithms while requiring orders of magnitude less runtime.
REAL-TIME SEISMOLOGY AND EARTHQUAKE DAMAGE MITIGATION
Authors: Kanamori Hiroo
Published: December 2004

▪ Abstract  Real-time seismology refers to a practice in which seismic data are collected and analyzed quickly after a significant seismic event, so that the results can be effectively used for postearthquake emergency response and early warning. As the technology of seismic instrumentation, telemetry, computers, and data storage facility advances, the real-time seismology for rapid postearthquake notification is essentially established. Research for early warning is still underway. Two approaches are possible: (a) regional warning and (b) on-site (or site-specific) warning. In (a), the traditional seismological method is used to locate an earthquake, determine the magnitude, and estimate the ground motion at other sites. In (b), the beginning of the ground motion (mainly P wave) observed at a site is used to predict the ensuing ground motion at the same site. An effective approach to on-site warning is discussed in light of earthquake rupture physics.
Detection of early central circulatory transits in patients with cirrhosis by gamma variate fit of indicator dilution profiles
Authors: Henriksen Jens H. , Møller Søren , Fuglsang Stefan , Bendtsen Flemming
Published: December 2004

Patients with cirrhosis have hyperdynamic circulation with abnormally distributed blood volume and widespread arteriovenous communications. We aimed to detect possible very early (i.e., before 4 s) and early (i.e., after 4 s) central circulatory transits and their potential influence on determination of central and arterial blood volume (CBV). Thirty-six cirrhotic patients and nineteen controls without liver disease undergoing hemodynamic catheterization were given central bolus injections of albumin with different labels. Exponential and gamma variate fits were applied to the indicator dilution curves, and the relations between flow, circulation times, and volumes were established according to kinetic principles. No significant very early central circulatory transits were identified. In contrast, early (i.e., 4 s to maximal) transits corresponding to a mean of 5.1% (vs. 0.8% in controls; P < 0.005) of cardiac output (equivalent to 0.36 vs. 0.05 l/min; P < 0.01) were found in cirrhotic patients. These early transits averaged 7.7 vs. 12.7 and 17.2 s of ordinary central transits of cirrhotic patients and controls, respectively ( P < 0.001). Early transits were directly correlated to the alveolar-arterial oxygen difference in the cirrhotic patients ( r = 0.46, P < 0.01) but not in controls ( r = 0.04; not significant). There was good agreement between the CBV determined by the conventional indicator dilution method and that determined by separation of early and ordinary transits by the gamma variate fit method (1.51 vs. 1.53 liter; not significant). In conclusion, no very early central circulatory transits were identified in cirrhotic patients. A significant part of the cardiac output undergoes an early transit, probably through pulmonary shunts or areas with low ventilation-perfusion ratios in cirrhotic patients. Composite determination of CBV by the gamma variate fit method is in close agreement with established kinetic methods. The study provides further evidence of abnormal central circulation in cirrhosis.
Regulation of RELM/FIZZ isoform expression byCdx2in response to innate and adaptive immune stimulation in the intestine
Authors: Wang Mei-Lun , Shin Marcus E. , Knight Pamela A. , Artis David , Silberg Debra G. , Suh Eunran , Wu Gary D.
Published: December 2004

Host immune responses to commensal flora and enteric pathogens are known to influence gene expression in the intestinal epithelium. Although the Cdx family of caudal-related transcription factors represents critical regulators of gene expression in the intestinal epithelium, the effect of intestinal immune responses on Cdx expression and function has not been determined. We have shown that bacterial colonization and Th2 immune stimulation by intestinal nematode infection induce expression of the intestinal goblet cell-specific gene RELMβ. In this study, we investigated the transcriptional regulation of resistin-like molecule/found in inflammatory zone (RELM/FIZZ, RELMβ) and its isoforms RELMα and RELMγ to ascertain the role of Cdx in modifying intestinal gene expression associated with innate and adaptive immune responses. Analysis of the RELMβ promoter showed that Cdx2 plays a critical role in basal gene activation in vitro. This was confirmed in vivo using transgenic mice, where ectopic gastric and hepatic expression of Cdx2 induces expression of RELMβ, but not RELMα or RELMγ, exclusively in the stomach. Although there was no quantitative change in colonic Cdx2 mRNA expression, protein distribution, or phosphorylation of Cdx2, bacterial colonization induced expression of RELMβ, but not RELMα or RELMγ. In contrast, parasitic nematode infections activated colonic expression of all three RELM isoforms without alteration in Cdx2 expression. These results demonstrated that Cdx2 participates in directing intestine-specific expression of RELMβ in the presence of commensal bacteria and that adaptive Th2 immune responses to intestinal nematode infections can activate intestinal goblet cell-specific gene expression independent of Cdx2.