bluuebunny/crossref_metadata_2025 huggingface dataset:
INDIVIDUALLY COMPUTED FINITE ELEMENT ANALYSIS OF THE NON-STEMMED ANATOMICAL TOTAL HIP PROSTHESIS
Authors: Chieng Poon-Ung , Chen Ching-I , Lin Chi-Chang , Tsai Ching-Lin , Chen Po-Quang
Published: July 2005

Background: Current total hip prosthesis lack an accurate individualized finite element model to assure an accurate fit, and further require amputation of a possibly healthy femoral neck.

Methods: This research presents a new methodology for performing an automated three-dimensional finite element meshing for a new type of total hip prosthesis. The stress analysis for this new design, known as Non-stemmed Anatomical Total Hip Prosthesis, is based on the methodology proposed here. The merit of this method is that the automated meshing process can be produced by using ANSYS software alone, without the need for a complicated, self-developed meshing interface program.

Results: This new methodology provides a smooth boundary around the contour of the femur and the interface between the femur and the Non-stemmed Anatomical Total Hip Prosthesis, as well as avoiding additional complications. This newly designed prosthesis involves minimal modification of the intact femoral neck alignment after total hip replacement, provided that the femoral neck is still healthy. The main body of this new prosthesis is a conical-shaped mask that tightly embraces the femoral neck. The bottom skirt of this mask contacts the greater and lesser trochanter in such a way that maintains the mask in the desired position using a screw through the axis of the femoral neck. Finite element stress analysis is performed to compare the stress distribution of the intact femur and the femur after implantation of the Non-stemmed Anatomical Total Hip Prosthesis.

Conclusions: Hopefully, this new prosthesis will be the method of choice for patients who have healthy femoral necks, but sick femoral heads. Further research can focus on applying this new methodology to other bone structures.

Level of Evidence: Therapeutic study, Level IV.
CHARACTERISTICS OF SOFT TISSUE MASS IN THE HAND BY ULTRASONOGRAPHIC EXAMINATION
Authors: Blankstein Alexander , Chechick Aharon , Adunski Abraham , Givon Uri , Mirovski Yigal , Ganel Avraham
Published: July 2005

Soft tissue masses are amongst the commonest complaints encountered in orthopedic practice. Of these, masses found in the hand and the wrist are presented at higher frequency. They are often painful and may cause limitation of movement.

This work describes the prevalence and the nature of soft tissue masses in the hand and wrist encountered in routine practice. This work was performed to assess the characteristics of soft tissue mass in the hand and the effectiveness of ultrasonography in the diagnosis of soft tissue masses and their differentiation from other lesions in the hand and wrist. Orthopedic surgical conditions that involve soft tissue in the hand and wrist may remain a diagnostic challenge when clinical diagnosis is uncertain and standard X-rays are non-diagnostic. High resolution ultrasound is widely available, non-invasive, without damage of radiation, imaging modality that can help the diagnosis.

We reviewed retrospectively 25 patients with soft tissue masses. We compared the ultrasound findings with the histological findings in seven operated patients.

A substantial majority of these lesions occurred in the right hand: 79% of the lesions were in the dorsal aspect of the hand, of which 37% were distal to the wrist joint, among them 42% at wrist either radial or ulnar; and 21% of the lesions were found in the volar aspect, among them 17% at wrist aspect, either radial or ulnar side. No predisposing factors could be found.

The findings of this study reaffirm the utility of ultrasonography as primary diagnostic tool in routine orthopedic practice.
EARLY MUSCLE AFFECTION IN CHURG–STRAUSS SYNDROME
Authors: Finsterer Josef , Haberler Christine
Published: July 2005

Purpose: Skeletal muscle affection already in the eosinophilic stage of Churg–Strauss syndrome (CSS) is unusual.

Case report: In a 36-year-old woman with a history of recurrent bronchial infections since childhood, recurrent poly-sinusitis and nasal polyps, and bronchial asthma, easy fatigability, weakness of the lower arms and lower legs, generalized myalgias with predominance of the lower arms, recurrent vertigo and falls developed. There was recurrently elevated creatine-kinase, glutamate-oxalate-transaminase, aldolase, lactate-dehydrogenase, eosinophilic granulocyte-count, thrombocyte-count, cholesterol, and blood sedimentation rate. Histologically polyps showed diffuse infiltrations of eosinophils exclusively. Muscle biopsy revealed grouped atrophic fibers, necrotic fibers, rarely regenerating fibers, epitheloid cells and rarely perimysial eosinophilic granulozytes. According to established criteria, CSS was diagnosed.

Conclusions: This case shows that affection of the skeletal muscle in CSS, may manifest as easy fatigability, myalgias, and recurrently elevated CK, and that skeletal muscle involvement may be a dominant feature not only of the vasculitic but also of the eosinophilic stage of CSS.
STOCHASTIC DYNAMICS OF ACTIVE AGENTS IN EXTERNAL FIELDS
Authors: EBELING WERNER , SCHIMANSKY-GEIER LUTZ , NEIMAN ALEXANDER , SCHARNHORST ANDREA
Published: July 2005

We study dynamics of active Brownian particles in two dimensions under the influence of external fields of forces. Several generic fields are considered, including symmetric linear attraction to a center, asymmetric linear attraction and a field described by a double well potential. We show the formation of limit cycles, which reflect collective rotational motion of the particles and study the influence of asymmetry on collective motion. In the case of the double well potential we study the transition rates between potential wells and show their crucial dependence on a parameter which determines activeness of the particles.
LOCATING CRITICAL LINES IN HIGH-VOLTAGE ELECTRICAL POWER GRIDS
Authors: CRUCITTI PAOLO , LATORA VITO , MARCHIORI MASSIMO
Published: July 2005

Electrical power grids are among the infrastructures that are attracting a great deal of attention because of their intrinsic criticality. Here we analyze the topological vulnerability and improvability of the spanish 400 kV, the french 400 kV and the italian 380 kV power transmission grids. For each network we detect the most critical lines and suggest how to improve the connectivity.
ROTATION OF F1-ATPASE: THE STOCHASTIC MODEL
Authors: POGREBNAYA ALEXANDRA , ROMANOVSKY YURY , TIKHONOV ALEXANDER
Published: July 2005

In this work, we consider a stochastic model describing the unidirectional rotation of the rotor (subunit γ) of F1-ATPase. For appropriate choice of the model parameters, we used literature data on dynamic parameters of F1-ATPase and results of our calculations of electrostatic interactions in enzyme-substrate complex of the catalytic cycle. The model takes into account thermal fluctuations of the bath and stochastic processes of substrate binding and product dissociation from the catalytic centers. The model provides an adequate description of ATP-driven rotations of subunit in F1-ATPase.
BROADBAND BACKGROUND IN RAMAN SPECTRA OF PROTEINS: DETERMINISTIC SIGNAL OR NOISE?
Authors: ARUTYUNYAN NATAL'YA R. , BRANDT NIKOLAI N. , CHIKISHEV ANDREY YU. , LEBEDENKO STEPAN I. , PARASHCHUK OLGA D. , RAZZHIVIN ANDREY P.
Published: July 2005

The broadband background inherent in the Raman spectra of proteins is analyzed using a dual approach. Mathematical methods are used to eliminate the background signal that determines the noise contribution to the Raman spectra. Regularities in the time dependence of the background intensity and their relation to the protein structure are experimentally studied.
GA BASED SENSOR PLACEMENT AND CONTROL DESIGN FOR REACTIVE NAVIGATION OF MOBILE ROBOTS
Authors: WANG XIAOCHUAN , YANG SIMON X. , MENG MAX Q.-H.
Published: July 2005

In this paper, a novel genetic algorithm based approach is proposed for optimal sensor placement and controller design of a mobile robot to facilitate its reactive navigation and obstacle avoidance in unknown environments. The mobile robots considered in this paper have flexible sensor and control structure. A genetic algorithm is developed to evolve the parameters of optimal sensor placement and controller design simultaneously. The effectiveness of the proposed GA based co-evolution approach to robot sensor placement and control design is demonstrated by simulation studies.
A DETECTIVE STUDY ON PARAXIAL DIGITAL HOLOGRAPHY IN ACQUIRING THE AMPLITUDE AND PHASE SIMULTANEOUSLY
Authors: LI JUN-CHANG , GUO RONG-XIN , WANG MIN
Published: July 2005

A theoretical model to actualize digital holographic detection with the help of paraxial optical system based on the inverse calculation of diffraction is introduced briefly. In addition, we proposed a method to actualize the measurement when the measured object modulates the amplitude and the phase of object light simultaneously. The simulated experimental example will be illustrated with the help of numerical computation and computer-aided image processing techniques.
A MODIFIED WIENER FILTER FOR MULTI-FRAME RESTORATION OF BLURRED AND NOISY IMAGES
Authors: EL-KHAMY S. E. , SAAD E. M. , HADHOUD M. M. , DESSOUKY M. I. , ABBAS A. M. , ABD EL-SAMIE F. E.
Published: July 2005

This paper proposes the use of a modified Wiener digital restoration technique for multi-frame image sequences that are degraded by both blur and noise. The proposed multi-channel Wiener restoration filter accounts for both intra-frame (spatial) and inter-frame (temporal) correlation. A modified cross-correlation formula between consecutive frames, which directly utilizes the motion vectors in the calculation of correlation among frames is derived and implemented in a multi-frame Wiener filter. Our modification estimates the motion vectors (horizontal and vertical) between consecutive frames using the three-step method, and then uses the estimated motion vectors to modify the cross-correlation terms in the formula for restoration. The performed simulations verified that the multi-frame restoration algorithm, that uses the motion information among different frames in restoration, gives improved results than both of the single frame independent restoration and the multi-channel restoration without considering the motion vectors.
DATA FUSION OF ROBOT WRIST FORCES BASED ON FINGER FORCE SENSORS AND MLF NEURAL NETWORK
Authors: TONG LI-BIAO , LU WEN-JUN , HONG XIN , MEI TAO , XU KE-JUN
Published: July 2005

Quantitative analysis of wrist forces for robot grippers is an important issue for robot control and operation safety. An approach is proposed to deduce the wrist forces from distributed force sensors in the robot fingers. A multi-layer forward (MLF) neural network is designed to fuse the data from finger force sensors. The experimental results demonstrate that the maximum deducing error of the wrist forces is decreased to 4.8% from 18.7% comparing with previous sensor fusion methods.
TRINOCULAR STEREO-BASED 3D REPRESENTATION OF DRIVING ENVIRONMENT USING U-V-DISPARITY
Authors: HU ZHENCHENG , UCHIMURA KEIICHI
Published: July 2005

Laser or millimeter wave radars have shown good performance in measuring relative speed and distance in a highway driving environment. However the accuracy of these systems decreases in an urban traffic environment as more confusion occurs due to factors such as parked vehicles, guardrails, poles and motorcycles. A trinocular stereo-based sensing system provides an effective supplement to radar-based road scene analysis with its much wider field of view and more accurate lateral information. This paper presents an efficient solution using a trinocular stereo based 3D representation method of driving environment which employs the "U-V-disparity" concept. It is used to classify a 3D road scene into relative surface planes and characterize the features of road pavement surfaces, roadside structures and obstacles. Real-time implementation of the trinocular stereo disparity calculation and the "U-V-disparity" classification algorithm is also presented in this paper.
A COMPOSITE PROBABILISTIC NEURAL NETWORK SYSTEM FOR PD PATTERN RECOGNITION
Authors: KARTHIKEYAN B. , GOPAL S. , VIMALA M.
Published: July 2005

Partial discharge patterns are an important tool for diagnosis of HV insulation systems. Skilled humans can identify the possible insulation defects in various representations of partial discharge (PD) data. One of the most widely used representation is phase resolved PD (PRPD) patterns. This paper describes a method for the automated recognition of PRPD patterns using a novel composite neural network system for the actual classification task. This paper elucidates the possible methods of extracting relevant features from the PRPD data in a knowledge based way i.e. according to physical properties of PD gained from PD modeling. This allows the novel complex neural network (NN) system for classification. The efficacy of composite neural network developed using original probabilistic neural network is examined. This innovative methodology of giving inputs to the composite neural network compares favorably with the traditional network architecture used previously for PD pattern recognition.
CONCENTRATION PREDICTION FROM OSCILLOPOLAROGRAPHIC SIGNALS VIA HIDDEN INFORMATION DETECTOR
Authors: LI JINPING , HAN YANBIN , YIN JIANQIN , ZHONG HONGBO
Published: July 2005

A practical and systematic scheme of concentration prediction of chemical substance from oscillopolarographic signals is presented, and a hidden information detector (HID) — put forward in our previous work — is employed. The HID consists of two connected neural networks called cascade neural networks, in which the first one extracts main features of signals by employing a modified DOG (difference of Gaussian) wavelet basis, and the second one predicts concentration from the extracted features by using a simple back-propagation neural networks in which a dipole sigmoid basis function is utilized instead of the traditional one. The application in predicting concentration of two kinds of chemical substance indicates the good quality of our scheme, which can be easily generalized to deal with solution containing three or more kinds of chemical substance.
STUDY OF A POSITION AND ORIENTATION TRACKING METHOD FOR WIRELESS CAPSULE ENDOSCOPE
Authors: WANG XIAONA , MENG MAX Q.-H.
Published: July 2005

This paper introduces a position and orientation tracking method, which has the potential to be used in capsule endoscope localization. This tracking method is based on the strength of the magnetic field generated by a magnetic marker in the space. Levenberg–Marquardt optimization algorithm is used for calculation of the parameters of the magnetic marker. The experiment results showed that when the axes of all sensors are all in one direction, the tracking results rely much on the orientation of the dipole. When the magnetic dipole is in sensor's axial direction, the tracking error is within 4 mm in a space of 60×60×100 mm enclosed by 8 hall sensors; the system is real time and quite robust. But the trackable scope becomes much smaller when the dipole has an arbitrary orientation. The reason is analyzed theoretically.
The Evolutionary Enigma of Mixed Mating Systems in Plants: Occurrence, Theoretical Explanations, and Empirical Evidence
Authors: Goodwillie Carol , Kalisz Susan , Eckert Christopher G.
Published: July 2005

▪ Abstract  Mixed mating, in which hermaphrodite plant species reproduce by both self- and cross-fertilization, presents a challenging problem for evolutionary biologists. Theory suggests that inbreeding depression, the main selective factor opposing the evolution of selfing, can be purged with self-fertilization, a process that is expected to yield pure strategies of either outcrossing or selfing. Here we present updated evidence suggesting that mixed mating systems are frequent in seed plants. We outline the floral and pollination mechanisms that can lead to intermediate outcrossing, review the theoretical models that address the stability of intermediate outcrossing, and examine relevant empirical evidence. A comparative analysis of estimated inbreeding coefficients and outcrossing rates suggests that mixed mating often evolves despite strong inbreeding depression. The adaptive significance of mixed mating has yet to be fully explained for any species. Recent theoretical and empirical work suggests that future progress will come from a better integration of studies of floral mechanisms, genetics, and ecology, and recognition of how selective pressures vary in space and time.
Life-History Evolution in Reptiles
Authors: Shine Richard
Published: July 2005

▪ Abstract  Two consequences of terrestrial ectothermy (low energy needs and behavioral control of body temperatures) have had major consequences for the evolution of reptile life-history traits. For example, reproducing females can manipulate incubation temperatures and thus phenotypic traits of their offspring by retaining developing eggs in utero. This ability has resulted in multiple evolutionary transitions from oviparity to viviparity in cool-climate reptile populations. The spatial and temporal heterogeneity of operative temperatures in terrestrial habitats also has favored careful nest-site selection and a matching of embryonic reaction norms to thermal regimes during incubation (e.g., via temperature-dependent sex determination). Many of the life-history features in which reptiles differ from endothermic vertebrates—such as their small offspring sizes, large litter sizes, and infrequent reproduction—are direct consequences of ectothermy, reflecting freedom from heat-conserving constraints on body size and energy storage. Ectothermy confers immense flexibility, enabling a dynamic matching of life-history traits to local circumstances. This flexibility has generated massive spatial and temporal variation in life-history traits via phenotypic plasticity as well as adaptation. The diversity of life histories in reptiles can best be interpreted within a conceptual framework that views reptiles as low-energy, variable-temperature systems.
FEEDBACK IN THE PLANT-SOIL SYSTEM
Authors: Ehrenfeld Joan G. , Ravit Beth , Elgersma Kenneth
Published: July 2005

▪ Abstract  Feedback between plants and the soil is frequently invoked on the basis of evidence of mutual effects. Feedback can operate through pathways involving soil physical properties, chemical and biogeochemical properties and processes, and biological properties, including the community composition of the microbiota and soil fauna. For each pathway, we review the mechanistic basis and assess the evidence that feedback occurs. We suggest that several properties of feedback systems (for example, their complexity, specificity, and strength relative to other ecological factors, as well as the temporal and spatial scales over which they operate) be considered. We find that the evidence of feedback is strongest for plants growing in extreme environments and for plant-mutualist or plant-enemy interactions. We conclude with recommendations for a more critical appraisal of feedback and for new directions of research.

Let us not make arbitrary conjectures about the greatest matters.

Heraclitus ( 1 )
ENVIRONMENTAL VALUES
Authors: Dietz Thomas , Fitzgerald Amy , Shwom Rachael
Published: July 2005

▪ Abstract  Values are often invoked in discussions of how to develop a more sustainable relationship with the environment. There is a substantial literature on values that spans several disciplines. In philosophy, values are relatively stable principles that help us make decisions when our preferences are in conflict and thus convey some sense of what we consider good. In economics, the term values is usually used in discussions of social choice, where an assessment of the social value of various alternatives serves as a guide to the best choice under a utilitarian ethic (the greatest good for the greatest number). In sociology, social psychology, and political science, two major lines of research have addressed environmental values. One has focused on four value clusters: self-interest, altruism, traditionalism, and openness to change and found relatively consistent theoretical and empirical support for the relationship of values to environmentalism. The other line of research suggests that environmentalism emerges when basic material needs are met and that individuals and societies that are postmaterialist in their values are more likely to exhibit pro-environmental behaviors. The evidence in support of this argument is more equivocal. Overall, the idea that values, especially altruism, are related to environmentalism, seems well established, but little can be said about the causes of value change and of the overall effects of value change on changes in behavior.
RIGHTEOUS OIL? HUMAN RIGHTS, THE OIL COMPLEX, AND CORPORATE SOCIAL RESPONSIBILITY
Authors: Watts Michael J.
Published: July 2005

▪ Abstract  One of the most important aspects of the rise of post-1945 global capitalism has been the call for transnational corporations to conform to basic human rights principles. This chapter reviews the efforts within the oil industry (with a particular focus on their operations in the less-developed countries) to develop corporate social responsibility and the related development of voluntary, legal, and statutory programs by governments, nongovernmental organizations (NGOs), civic groups, and multilateral agencies to ensure that the oil industry is compliant with important human, social, political, and environmental rights. In reviewing these developments, I outline the current political economy of the oil industry, new bodies of research on the relations between oil, violence, and human rights violations, which include case studies of the human rights records of transnational and joint-venture oil operations.
ECONOMICS OF POLLUTION TRADING FOR SO2AND NOX
Authors: Burtraw Dallas , Evans David A. , Krupnick Alan , Palmer Karen , Toth Russell
Published: July 2005

▪ Abstract  For years economists have urged policy makers to use market-based approaches such as cap-and-trade programs or emission taxes to control pollution. The sulfur dioxide (SO2) allowance market created by Title IV of the 1990 U.S. Clean Air Act Amendments represents the first real test of the wisdom of economists’ advice. Subsequent urban and regional applications of nitrogen oxides (NOx) emission allowance trading took shape in the 1990s in the United States, culminating in a second large experiment in emissions trading in the eastern United States that began in 2003. This review provides an overview of the economic rationale for emissions trading and a description of the major U.S. programs to reduce SO2and NOxpollution. We evaluate these programs along measures of performance, which include cost savings, environmental integrity, and incentives for technological innovation. We offer lessons for the design of future programs including, most importantly, those to reduce carbon dioxide.
STRUCTURE OF THE MUSHROOM BODIES OF THE INSECT BRAIN
Authors: Fahrbach Susan E.
Published: July 2005

▪ Abstract  The past decade has produced an explosion of new information on the development, neuroanatomy, and possible functions of the mushroom bodies. This review provides a concise, contemporary overview of the structure of the mushroom bodies. Two topics are highlighted: the volume plasticity of mushroom body neuropils evident in the brains of some adult insects and a possible essential role for the γ lobe in olfactory memory.
INSECT BIODIVERSITY OF BOREAL PEAT BOGS
Authors: Spitzer Karel , Danks Hugh V.
Published: July 2005

▪ Abstract  Boreal peat bogs contain distinctive insects in addition to widely distributed generalists, including species restricted to bogs (tyrphobionts) and species characteristic of bogs but not confined to them (tyrphophiles). Bogs raised above the water table form characteristic habitat islands in southern boreal and temperate forest zones. Many bogs have persisted for hundreds and even thousands of years, preserving relict ecosystems related to subarctic biomes. The historical development and nature of individual bogs are reflected by differences among their insects, which are of great biogeographical and ecological interest. The environmental sensitivity of bogs also makes insects valuable as bioindicators. Moreover, few readily accessible bogs remain in a natural state. Given the scientific interest of bog insects and the fact that each relict bog habitat island is unique, further studies of the diversity of bog faunas are merited, and the conservation of these habitats should be strongly supported by entomologists.
PLANT CHEMISTRY AND NATURAL ENEMY FITNESS: Effects on Herbivore and Natural Enemy Interactions
Authors: Ode Paul J.
Published: July 2005

▪ Abstract  Tremendous strides have been made regarding our understanding of how host plant chemistry influences the interactions between herbivores and their natural enemies. While most work has focused on plant chemistry effects on host location and acceptance by natural enemies, an increasing number of studies examine negative effects. The tritrophic role of plant chemistry is central to several aspects of trophic phenomena including top-down versus bottom-up control of herbivores, enemy-free space and host choice, and theories of plant defense. Furthermore, tritrophic effects of plant chemistry are important in assessing the degree of compatibility between biological control and plant resistance approaches to pest control. Additional research is needed to understand the physiological effects of plant chemistry on parasitoids. Explicit tests are required to determine whether natural enemies can act as selective forces on plant defense. Finally, further studies of natural systems are crucial to understanding the evolution of multitrophic relationships.
APPARENT COMPETITION, QUANTITATIVE FOOD WEBS, AND THE STRUCTURE OF PHYTOPHAGOUS INSECT COMMUNITIES
Authors: Frank van Veen F.J. , Morris Rebecca J. , Godfray H. Charles J.
Published: July 2005

▪ Abstract  Phytophagous insects and their natural enemies make up one of the largest and most diverse groups of organisms on earth. Ecological processes, in particular negative indirect effects mediated by shared natural enemies (apparent competition), may be important in structuring phytophagous insect communities. The potential for indirect interactions can be assessed by analyzing the trophic structure of insect communities, and we claim that quantitative food webs are particularly well suited for this task. We review the experimental evidence for both short-term and long-term apparent competition in phytophagous insect communities and discuss the possible interactions between apparent competition and intraguild predation or shared mutualists. There is increasing evidence for the importance of trait-mediated as well as density-mediated indirect effects. We conclude that there is a need for large-scale experiments manipulating communities in their entirety and a greater integration of community and chemical ecology.
FEMINISM, FAIRNESS, AND WELFARE: An Invitation to Feminist Law and Economics
Authors: Hadfield Gillian K.
Published: July 2005

▪ Abstract  In recent years there has been a renewed effort to ground conventional law and economics methodology, with its exclusive focus on efficiency and income redistribution through the tax system, in modern welfare economics ( Kaplow & Shavell 1994 , 2001 ). This effort raises a challenge to the possibility of a feminist law and economics: Is it possible to be a good (welfare) economist and still maintain the ethical and political commitments necessary to address feminist concerns with, for example, rights, inequality, and caring labor? In this review, I argue that modern welfare economics, rather than supporting the ethical minimalism of conventional methodology advocated by Kaplow and Shavell, ratifies the need for an ethically and politically informed economic analysis. Feminists can, and should, use the tools of both positive and normative economics to analyze feminist issues in law.
BIOGENESIS OF INNER MEMBRANE PROTEINS IN ESCHERICHIA COLI
Authors: Luirink Joen , Heijne Gunnar von , Houben Edith , Gier Jan-Willem de
Published: July 2005

Gram-negative bacteria such as Escherichia coli are surrounded by two membranes, the inner membrane and the outer membrane. The biogenesis of most inner membrane proteins (IMPs), typical α-helical proteins, appears to follow a partly conserved cotranslational pathway. Targeting involves a relatively simple signal recognition particle (SRP) and SRP-receptor. Insertion of most IMPs into the membrane occurs via the Sec-translocon, which is also used for the vectorial transport of secretory proteins. Similar to eukaryotic systems, little is known about the later stages of biogenesis of IMPs, the folding and assembly in the lipid bilayer. Recently, YidC has been identified as a factor that assists in the integration, folding, and assembly of IMPs both in association with the Sec-translocon and separately. This review deals mainly with recent structural and biochemical data from various experimental systems that offer new insight into the different stages of biogenesis of E. coli IMPs.
Minmax strongly connected subgraphs with node penalties
Authors: Punnen Abraham P.
Published: July 2005

We propose an O(min{m+n log n,m log∗n}) to find a minmax strongly connected spanning subgraph of a digraph with n nodes and m arcs. A generalization of this problem called the minmax strongly connected subgraph problem with node penalties is also considered. An O(m log n) algorithm is proposed to solve this general problem. We also discuss ways to improve the average complexity of this algorithm.
A new modeling and solution approach for the number partitioning problem
Authors: Alidaee Bahram , Glover Fred , Kochenberger Gary A. , Rego Cesar
Published: July 2005

The number partitioning problem has proven to be a challenging problem for both exact and heuristic solution methods. We present a new modeling and solution approach that consists of recasting the problem as an unconstrained quadratic binary program that can be solved by efficient metaheuristic methods. Our approach readily accommodates both the common two-subset partition case as well as the more general case of multiple subsets. Preliminary computational experience is presented illustrating the attractiveness of the method.
On the orthogonalization of arbitrary Boolean formulae
Authors: Bruni Renato
Published: July 2005

The orthogonal conjunctive normal form of a Boolean function is a conjunctive normal form in which any two clauses contain at least a pair of complementary literals. Orthogonal disjunctive normal form is defined similarly. Orthogonalization is the process of transforming the normal form of a Boolean function to orthogonal normal form. The problem is of great relevance in several applications, for example, in the reliability theory. Moreover, such problem is strongly connected with the well-known propositional satisfiability problem. Therefore, important complexity issues are involved. A general procedure for transforming an arbitrary CNF or DNF to an orthogonal one is proposed. Such procedure is tested on randomly generated Boolean formulae.
A problem of finding an acceptable variant in generalized project networks
Authors: Blokh David , Gutin Gregory , Yeo Anders
Published: July 2005

A project network often has some activities or groups of activities which can be performed at different stages of the project. Then, the problem of finding an optimal/acceptable time or/and optimal/acceptable order of such an activity or a group of activities arises. Such a problem emerges, in particular, in house-building management when the beginnings of some activities may vary in time or/and order. We consider a mathematical formulation of the problem, show its computational complexity, and describe an algorithm for solving the problem.
A combinatorial arc tolerance analysis for network flow problems
Authors: Sokkalingam P. T. , Sharma Prabha
Published: July 2005

For the separable convex cost flow problem, we consider the problem of determining tolerance set for each arc cost function. For a given optimal flow x, a valid perturbation of cij(x) is a convex function that can be substituted for cij(x) in the total cost function without violating the optimality of x. Tolerance set for an arc(i,j) is the collection of all valid perturbations of cij(x). We characterize the tolerance set for each arc(i,j) in terms of nonsingleton shortest distances between nodes i and j. We also give an efficient algorithm to compute the nonsingleton shortest distances between all pairs of nodes in O(n3) time where n denotes the number of nodes in the given graph.
Δ-matroid and jump system
Authors: Kabadi Santosh N. , Sridhar R.
Published: July 2005

The concept of Δ-matroid is a nontrivial, proper generalization of the concept of matroid and has been further generalized to the concept of jump system. In this paper, we show that jump systems are, in some sense, equivalent to Δ-matroids. Using this equivalence and the Δ-matroid theory, we give simple proofs and extensions of many of the results on jump systems.
Inhibition of Atherogenesis in BLT1-Deficient Mice Reveals a Role for LTB4 and BLT1 in Smooth Muscle Cell Recruitment
Authors: Heller Eric A. , Liu Emerson , Tager Andrew M. , Sinha Sumita , Roberts Jesse D. , Koehn Stephanie L. , Libby Peter , Aikawa Elena Rabkin , Chen Ji Qiu , Huang Paul , Freeman Mason W. , Moore Kathryn J. , Luster Andrew D. , Gerszten Robert E.
Published: July 2005

Background—

It is known that 5-lipoxygenase and its product, leukotriene B4 (LTB
4
), are highly expressed in several human pathologies, including atherosclerotic plaque. LTB
4
signals primarily through its high-affinity G protein-coupled receptor BLT1, which is expressed on specific leukocyte subsets. BLT1 receptor expression and function on other atheroma-associated cell types is unknown.

Methods and Results—

To directly assess the role of the LTB
4
-BLT1 pathway in atherogenesis, we bred BLT1
−/−
mice into the atherosclerosis-susceptible apoE
−/−
strain. Compound-deficient apoE
−/−
/Blt1
−/−
mice fed a Western-type diet had a marked reduction in plaque formation compared with apoE
−/−
controls. Immunohistochemical analysis of atherosclerotic lesions in compound-deficient mice revealed a striking decrease in smooth muscle cells (SMCs) and significant decreases in macrophages and T cells. We report here novel evidence of the expression and function of BLT1 on vascular SMCs. LTB
4
triggered SMC chemotaxis, which was pertussis toxin sensitive in Blt1
+/+
SMCs and absent in Blt1
−/−
cells, suggesting that BLT1 was the dominant receptor mediating effector functions through a G protein-coupled signaling pathway. Furthermore, BLT1 colocalized with SMCs in human atherosclerotic lesions.

Conclusions—

These new findings extend the role of inducible BLT1 to nonleukocyte populations and suggest an important target for intervention to modulate the response to vascular injury.
Ensemble Kalman Filter Assimilation of Doppler Radar Data with a Compressible Nonhydrostatic Model: OSS Experiments
Authors: Tong Mingjing , Xue Ming
Published: July 2005

A Doppler radar data assimilation system is developed based on an ensemble Kalman filter (EnKF) method and tested with simulated radar data from a supercell storm. As a first implementation, it is assumed that the forward models are perfect and that the radar data are sampled at the analysis grid points. A general purpose nonhydrostatic compressible model is used with the inclusion of complex multiclass ice microphysics. New aspects of this study compared to previous work include the demonstration of the ability of the EnKF method to retrieve multiple microphysical species associated with a multiclass ice microphysics scheme, and to accurately retrieve the wind and thermodynamic variables. Also new are the inclusion of reflectivity observations and the determination of the relative role of the radial velocity and reflectivity data as well as their spatial coverage in recovering the full-flow and cloud fields. In general, the system is able to reestablish the model storm extremely well after a number of assimilation cycles, and best results are obtained when both radial velocity and reflectivity data, including reflectivity information outside of the precipitation regions, are used. Significant positive impact of the reflectivity assimilation is found even though the observation operator involved is nonlinear. The results also show that a compressible model that contains acoustic modes, hence the associated error growth, performs at least as well as an anelastic model used in previous EnKF studies at the cloud scale.

Flow-dependent and dynamically consistent background error covariances estimated from the forecast ensemble play a critical role in successful assimilation and retrieval. When the assimilation cycles start from random initial perturbations, better results are obtained when the updating of the fields that are not directly related to radar reflectivity is withheld during the first few cycles. In fact, during the first few cycles, the updating of the variables indirectly related to reflectivity hurts the analysis. This is so because the estimated background covariances are unreliable at this stage of the data assimilation process, which is related to the way the forecast ensemble is initialized. Forecasts of supercell storms starting from the best-assimilated initial conditions are shown to remain very good for at least 2 h.
Test of a Poor Man’s Ensemble Prediction System for Short-Range Probability Forecasting
Authors: Arribas A. , Robertson K. B. , Mylne K. R.
Published: July 2005

Current operational ensemble prediction systems (EPSs) are designed specifically for medium-range forecasting, but there is also considerable interest in predictability in the short range, particularly for potential severe-weather developments. A possible option is to use a poor man’s ensemble prediction system (PEPS) comprising output from different numerical weather prediction (NWP) centers. By making use of a range of different models and independent analyses, a PEPS provides essentially a random sampling of both the initial condition and model evolution errors. In this paper the authors investigate the ability of a PEPS using up to 14 models from nine operational NWP centers. The ensemble forecasts are verified for a 101-day period and five variables: mean sea level pressure, 500-hPa geopotential height, temperature at 850 hPa, 2-m temperature, and 10-m wind speed. Results are compared with the operational ECMWF EPS, using the ECMWF analysis as the verifying “truth.” It is shown that, despite its smaller size, PEPS is an efficient way of producing ensemble forecasts and can provide competitive performance in the short range. The best relative performance is found to come from hybrid configurations combining output from a small subset of the ECMWF EPS with other different NWP models.
High-Resolution Observations of Mammatus in Tropical Anvils
Authors: Kollias Pavlos , Jo Ieng , Albrecht Bruce A.
Published: July 2005

Unprecedented high-resolution observations of mammatus from a profiling 94-GHz Doppler radar during the NASA Cirrus Regional Study of Tropical Anvils and Cirrus Layers–Florida Area Cirrus Experiment (CRYSTAL–FACE) are presented. Because of its high sensitivity and temporal and spatial resolution, the cloud radar used was able to resolve the fine structure of individual mammatus clouds and record significant vertical Doppler velocity perturbations (−6 to +1 m s−1). Strong perturbations of the Doppler velocity within the mammatus as it extends below the main cirrus cloud base are captured by the radar observations. Upward motions in the periphery of descending mammatus cores are documented. Areas of intense, small-scale turbulent mixing near the cirrus cloud base are identified using the Doppler spectrum width. Power spectra analysis of the mean Doppler velocity field supports the presence of gravity waves and the development of higher-frequency structures near the cirrus anvil base, where the mammatus clouds are observed. The observations provide strong evidence for dynamical forcing from coherent vertical motions 500 m above the cloud base contributing to the mammatus formation. The results are discussed in the context of suggested theories for mamma formation and morphology.
Roots of Ensemble Forecasting
Authors: Lewis John M.
Published: July 2005

The generation of a probabilistic view of dynamical weather prediction is traced back to the early 1950s, to that point in time when deterministic short-range numerical weather prediction (NWP) achieved its earliest success. Eric Eady was the first meteorologist to voice concern over strict determinism—that is, a future determined by the initial state without account for uncertainties in that state. By the end of the decade, Philip Thompson and Edward Lorenz explored the predictability limits of deterministic forecasting and set the stage for an alternate view—a stochastic–dynamic view that was enunciated by Edward Epstein.

The steps in both operational short-range NWP and extended-range forecasting that justified a coupling between probability and dynamical law are followed. A discussion of the bridge from theory to practice follows, and the study ends with a genealogy of ensemble forecasting as an outgrowth of traditions in the history of science.
Probabilistic Prediction of Tropical Cyclones. Part II: Intensity
Authors: Weber Harry C.
Published: July 2005

A new objective aid for operational probabilistic intensity (defined as maximum wind speed) prediction of tropical cyclones is presented. Based on statistical analyses of the performance of all operationally available numerical models (using datasets of the U.S. Navy’s Automated Tropical Cyclone Forecasting System) during training periods defined by the years 2000 and 2001, probabilistic and, as a by-product, deterministic intensity predictions were carried out for all global tropical-cyclone events during subsequent forecast periods defined by the years 2001 and 2002, respectively.

The annual mean deterministic intensity errors of the years 2001 (2002) at 24-, 48-, 72-, 96-, and 120-h prediction time were found to be 6.2 (6.5), 9.6 (10.6), 11.7 (12.4), 15.4 (15.3), and 17.2 (17.1) m s−1, respectively. On average, the deterministic forecasts were of approximately the same quality as those of all current consensus approaches and of superior quality than those of the majority of all operational dynamical models. The quality of the probabilistic forecasts, provided in the form of intensity probability intervals at given prediction times, was assessed by the annual mean sizes of given probability intervals. For example, in the years 2001 (2002) the annual mean sizes of the 66% confidence intervals at 24-, 48-, 72-, 96-, and 120-h prediction times were found to be 12.6 (13.3), 19.7 (21.5), 24.4 (24.8), 39.6 (27.8), and 40.4 (29.0) m s−1, respectively. Postanalyses showed that the sizes of all intensity probability intervals represented conservative and reliable estimates of future storm intensities in that the observed percentages of storm intensities inside given intervals were larger than the corresponding expected percentages.
Probabilistic Prediction of Tropical Cyclones. Part I: Position
Authors: Weber Harry C.
Published: July 2005

A new objective aid for operational prediction of the positions of tropical cyclones is presented. Its method is based on a simple analysis of the performance of all operationally available numerical models during a training period. In a subsequent forecast period, the results of this analysis are used to produce both high-quality deterministic (as by-product) and probabilistic storm position forecasts in the form of geographical maps of strike probability for all prediction times out to 120 h from a given base date and time.

The model was developed using operationally available position predictions of all global tropical-cyclone events of the years 2000, 2001, and 2002 as provided in the U.S. Navy’s Automated Tropical Cyclone Forecasting System (ATCF). Forecasts have been carried out for the years 2001 and 2002, with corresponding training periods 2000 and 2001. The global annual mean deterministic position errors for the years 2001 (2002) were 148 (136), 266 (235), 393 (329), 541 (435), and 733 (554) km at 24-, 48-, 72-, 96-, and 120-h prediction times, respectively. The deterministic mean errors and their corresponding standard deviations were found to be lower than those of most statistical and dynamical operational models and approximately equal to those of all consensus approaches currently in operational use.

The main feature of the new method is the automatic production of geographical strike probability maps. For all tropical-cyclone events during the year 2001 (2002), the mean annual diameters of, for example, the 66% strike probability regions (i.e., the regions inside which future storm positions can be expected with a probability of 66%) at 24-, 48-, 72-, 96-, and 120-h prediction time were found to be 290 (280), 490 (480), 710 (660), 1020 (780), and 1310 (1020) km, respectively. At all prediction times, the predicted sizes of areas of given strike probability represent conservative estimates in that the observed percentages of storm positions inside these areas are larger than the corresponding expected percentages.
Spurious Convective Organization in Simulated Squall Lines Owing to Moist Absolutely Unstable Layers
Authors: Bryan George H.
Published: July 2005

A spurious updraft pattern has been documented in some numerical simulations of squall lines. The pattern is notable because of a regular, repeating pattern of updrafts and downdrafts that are three–six grid lengths wide. This study examines the environmental and numerical conditions that lead to this problem. The spurious pattern is found only in simulations of upshear-tilted convective systems. Furthermore, the pattern coincides with deep (2–3 km) and wide (5–20 km) moist absolutely unstable layers (MAULs)—saturated layers of air that are statically unstable. In this physical environment, small-scale perturbations grow rapidly. The necessarily imperfect numerical schemes of the model introduce spurious small-scale perturbations into the MAULs, and these perturbations amplify owing to the unstable stratification. Some techniques are investigated that diffuse the perturbations or minimize their introduction in the statically unstable flow.