bluuebunny/crossref_metadata_2025 huggingface dataset:
Remodeling of Outward K+ Currents in Pressure‐Overload Heart Failure
Authors: WANG YANGGAN , CHENG JUN , CHEN GUOHUA , ROB FARHANA , HARIS NASEEM R. , NGUYEN LAN , JOHNSTONE JANET L. , HILL JOSEPH A.
Published: May 2007

Objectives: Outward K+ currents are critical determinants of action potential repolarization and the site of action of a number of electrophysiologically active drugs. Further, expression and processing of the channels underlying these currents is altered in heart disease. Here, we investigated the native transmural gradient of outward K+ currents in murine left ventricle (LV) and delineated disease‐related remodeling of these currents in heart failure (HF).

Methods: Pressure‐overload heart failure was induced in mice by thoracic aortic constriction. Outward K+ currents were recorded using the whole‐cell patch clamp technique in acutely dissociated ventricular myocytes.

Results: Unambiguous gradients of outward K+ current density and Kv4.2 protein abundance were observed across the wall of the LV, with significantly larger current density and protein levels in subepicardial (SEP) myocytes, compared with subendocardial (SEN) myocytes. Voltage dependences of current activation and inactivation were similar in SEP and SEN myocytes. In failing LV, however, outward K+ current density was significantly decreased in SEP but not in SEN cells leading to elimination of the native transmural gradient. In failing LV, the voltage dependences of K+ current activation and inactivation were not altered. However, current inactivation (decay) was significantly accelerated and recovery from inactivation was significantly slowed. Consistent with this, Western blot analysis revealed a decrease in KChIP2 protein abundance in failing LV.

Conclusions: This is the first report of HF‐related remodeling of outward K+ currents in murine LV. Similar to humans, disease‐related remodeling occurs differentially across the murine ventricular wall, leading to loss of the native gradient of repolarization. Together with slowed recovery from inactivation, these alterations likely promote abnormal impulse conduction, a major proarrhythmic mechanism.
Self‐Efficacy and Quality of Life of Professionals Caring for Individuals With Intellectual Disabilities
Authors: Nota Laura , Ferrari Lea , Soresi Salvatore
Published: May 2007

Abstract  The quality of life experienced by social and healthcare professionals is among the factors that contribute to the definition of quality of service. Other factors seemingly in relation with experienced quality of life concern one’s own efficacy, beliefs, and burnout. The present study intended to verify the relations that existed between these variables and the relation between professionals’ characteristics and those of the users who benefited from their professional interventions. Involved were 146 social and healthcare professionals and 68 adults with intellectual disabilities. Concerning the influence of length of service, the analyses determined that significant increments exist in emotional exhaustion and depersonalization. There were increments, albeit not generalized, also with respect to self‐efficacy. Satisfaction did not actually increase over time. Results from a discriminant functional analysis showed that only confidence in one’s own ability to work in a team and establish productive and collaborative relationships with colleagues and superiors was a significant predictor of quality‐of‐life status. Further, the social and healthcare professionals who had higher levels of confidence in their own professional abilities cared for the individuals who showed greater self‐determination, higher quality of life, and social skills.
Informational Digest Bulletin from San Raffaele Foundation and Tosinvest Sanità (No. 12). “My Name Is Alex”
Authors: Vitali Lynda A. Johnson
Published: May 2007

Abstract  A personal reflection on the experiences of a family that lived through the drama of a baby born with Down syndrome.
Contamination: Nursing Diagnoses with Outcome and Intervention Linkages
Authors: Polk Laura V. , Green Pauline M.
Published: May 2007

PURPOSE.  To relate the collaborative processes involved in the evolution of environmental nursing diagnoses and the linkages between two new nursing diagnoses and their associated interventions and outcomes; to describe the environmental health implications of contamination.

DATA SOURCES.  Published research articles, official reports, textbooks, and collaborative discussion with experts in community and global health.

DATA SYNTHESIS.  Reflection following review of the literature and collaboration with experts led to the development of a new schema for environmental diagnoses and development of two new diagnoses, allowing for greater clarity and distinction between the contamination diagnoses and risk for poisoning diagnosis.

CONCLUSIONS.  An environmental nursing diagnosis schema, with its emphasis on contamination, infection, and violence, provides nurses with a holistic framework for making judgments about environmental influences related to individual, family, community, and global health. The diagnoses of Contamination and Risk for Contamination provide necessary language to describe human responses and risk states that may arise following exposure to environmental contaminants.

PRACTICE IMPLICATIONS.  Development of environmental diagnostic labels and delineation of the linkages to nursing outcomes and interventions will allow nurses to take active roles in identifying environmental components that affect health and planning care that responds to environmental health needs. Greater clarity in the use of language will allow nurses to incorporate environmental concepts appropriately in nursing assessments and improve the accuracy of the diagnostic process and selection of distinct interventions and outcomes. This will result in better outcomes for patients and communities and permit greater accountability of nursing's contribution to environmental health.
Developing Conservation Priorities Based on Forest Type, Condition, and Threats in a Poorly Known Ecoregion: Sulawesi, Indonesia
Authors: Cannon Charles H. , Summers Marcy , Harting John R. , Kessler Paul J.A.
Published: May 2007

The island of Sulawesi is the largest in Indonesian Wallacea, one of the most important ecoregions in SE Asia and globally. Here, we generate a comprehensive and detailed map of forest type, its condition, and some of its threats, which highlights key forest conservation areas, pinpoints frontlines within them, and provides the basis for the development of more specific objectives. We relied upon a variety of techniques to generate five main descriptors of forest quality: condition, its level of endangerment, its landscape setting, its simulated fate given a simple model of forest change, and its overall size. Using the results of this analysis, we assessed the existing protected areas (PA), recognized by the Indonesian government, and a conservation portfolio (CP) generated by a recently completed Ecoregional Conservation Assessment (ECA). Our map of conservation priorities is congruent with previous conservation activities, although several priority areas were identified outside of the current PA system and should be the focus of strategic protected area development. Our ranking system is simple, transparent, and flexible. Its modular construction will allow local managers to choose among available proxy measures and to add their own conservation values according to specific priorities and desired outcomes. We envision this analysis as the foundation upon which more specific conservation strategies, based upon detailed biotic information as it becomes available, can be developed.
The Old and Young Amazon: Dung Beetle Biomass, Abundance, and Species Diversity
Authors: Radtke M. G. , Da Fonseca C. R. V. , Williamson G. B.
Published: May 2007

The Amazon Basin can be divided into two geomorphological regions based on the age of its soils: young (< 30 mya) and old (> 300 mya). We tested the effects of soil age on dung beetle communities by comparing biomass, abundance, and species between reserves in Ecuador on young soils and reserves in Brazil on old soils. Beetle biomass in the old Amazon was one‐third that in the young Amazon, and beetle abundance in the old Amazon was one‐fourth that in the young Amazon. Species richness, rarefied to equal sample sizes, was not significantly different between old and young soils. These data suggest young soils of the Amazon support a significantly greater biomass and abundance of dung beetles than old soils, but that species richness across the Basin is similar. As dung beetles are bio‐indicators of mammals, our data support previous studies indicating a greater biomass of mammals on young versus old Amazon soils.
Influence of Immersion Freezing in NaCl Solutions and of Frozen Storage on the Viscoelastic Behavior of Mozzarella Cheese
Authors: Ribero G.G. , Rubiolo A.C. , Zorrilla S.E.
Published: May 2007

ABSTRACT: The freezing of Mozzarella cheese by immersion in NaCl solutions may be an innovative procedure for the dairy industry because it combines conveniently salting and freezing processes. In this work, the influence of this type of freezing method and of the frozen storage of samples on the viscoelastic behavior of Mozzarella cheese was studied. Slabs (2 × 10 × 10 cm3) were immersed in 23% w/w NaCl solutions (control samples: 4 °C, 90 min; frozen samples: −15 °C, 180 min). Half of the frozen samples were immediately thawed at 4 °C . The other half was stored at −20 °C for 2 mo and then was thawed at 4 °C (frozen‐stored samples). Samples were stored at 4 °C and assayed at 1, 7, 14, 20, 27, 34, and 41 d. Rheological tests were carried out in oscillatory mode (parallel‐plate geometry, diameter: 20 mm, gap: 1 mm, frequency: 1 Hz). Strain sweeps were run (0.001 ≤γ0≤ 0.1) at 20, 40, and 60 °C, and temperature sweeps were run from 20 to 65 °C (1.33 °C/min, γ0= 0.005). Similar crossover temperatures were observed after 20 d of ripening. The influence of temperature on complex viscosity was studied by an Arrhenius‐type equation. Activation energy values of 15.9 ± 0.4, 14.1 ± 0.5, and 13.8 ± 0.6 kcal/mol were obtained at 41 d for control, frozen, and frozen‐stored samples, respectively. Although the immersion freezing of Mozzarella cheese affects some of the studied parameters, the differences observed between frozen and frozen‐stored samples with control samples were small. Therefore, it was considered that the immersion freezing might be useful for the manufacture and commercialization of Mozzarella cheese.
Cirrhosis and endotoxin decrease urea synthesis in rats
Authors: Nielsen Susanne Schouw , Grøfte Thorbjørn , Tygstrup Niels , Vilstrup Hendrik
Published: May 2007

Aim:  In patients with cirrhosis, endotoxemia is frequent and the vitally important capacity for urea synthesis is impaired. The patients’ mortality of infection is markedly increased, which could be related to adverse metabolic effects of endotoxins. The effects of endotoxins on in vivo urea synthesis and on urea cycle genes during cirrhosis are unknown.

Methods:  We examined the effects of a low dose of 0.5 mg/kg ip lipopolysaccharide (LPS) on the basal urea nitrogen synthesis rate (UNSR), the capacity of urea nitrogen synthesis (CUNS), liver tissue mRNA levels of urea cycle enzyme genes, and on the metabolic liver function measured by the galactose elimination capacity (GEC) in rats with cirrhosis induced by bile duct ligation and in control animals.

Results:  LPS and cirrhosis + LPS decreased UNSR by 40% (P < 0.05). Cirrhosis and LPS each tended to decrease CUNS and cirrhosis + LPS decreased CUNS by 40% (P < 0.05). Cirrhosis and LPS each decreased the mRNA level of the gene for the flux‐generating urea cycle enzyme carbamoyl phosphate synthetase (CPS) and the mRNA for the rate‐limiting urea cycle enzyme arginine succinate synthetase (ASS) (P < 0.05). Cirrhosis + LPS left the mRNA level of CPS unchanged and decreased that of ASS (P < 0.05). The GEC did not differ among the study groups.

Conclusion:  Endotoxemia in rats with experimental cirrhosis markedly impaired the ability of the animals’ livers to synthesize urea, suggesting a pathophysiological mechanism underlying the severe consequences of endotoxemia in human cirrhosis.
The effect of supplementation with branched‐chain amino acids in patients with liver cirrhosis
Authors: Urata Yohei , Okita Kosuke , Korenaga Keiko , Uchida Koichi , Yamasaki Takahiro , Sakaida Isao
Published: May 2007

Aim:  We investigated the effect of supplementation with branched‐chain amino acids (BCAA) in patients with liver cirrhosis on the change of energy metabolism as well as glucose tolerance.

Methods:  Thirty liver cirrhosis patients underwent nutrient supervision by a dietician for one week. They were then prescribed oral supplementation with three packs of a BCAA nutrient (Livact 4.15 g/pack; Ajinomoto Pharma, Tokyo, Japan), taken three times a day: after breakfast, dinner and before sleep. The change in energy metabolism and glucose tolerance was examined using an indirect calorimeter and 75 g oral glucose tolerance test (75 g OGTT).

Results:  Non‐protein respiratory quotient (npRQ) as well as branched‐chain amino acid/tyrosine ratio (BTR) showed significant improvement, especially in patients with a creatinine height index (CHI) greater than 80. There was also a significant correlation between npRQ after one week of BCAA supplementation and the CHI. The patients with CHI greater than 80 and those with borderline pattern assessed by 75 g OGTT showed significant improvement in impaired glucose tolerance.

Conclusion:  Liver cirrhosis patients with CHI greater than 80 are the first candidates for BCAA supplementation. These patients showed improvement not only in energy metabolism and BTR, but also glucose tolerance.
Null-Field Approach for the Multi-inclusion Problem Under Antiplane Shears
Authors: Chen Jeng-Tzong , Wu An-Chien
Published: May 2007

In this paper, we derive the null-field integral equation for an infinite medium containing circular holes and/or inclusions with arbitrary radii and positions under the remote antiplane shear. To fully capture the circular geometries, separable expressions of fundamental solutions in the polar coordinate for field and source points and Fourier series for boundary densities are adopted to ensure the exponential convergence. By moving the null-field point to the boundary, singular and hypersingular integrals are transformed to series sums after introducing the concept of degenerate kernels. Not only the singularity but also the sense of principle values are novelly avoided. For the calculation of boundary stress, the Hadamard principal value for hypersingularity is not required and can be easily calculated by using series sums. Besides, the boundary-layer effect is eliminated owing to the introduction of degenerate kernels. The solution is formulated in a manner of semi-analytical form since error purely attributes to the truncation of Fourier series. The method is basically a numerical method, and because of its semi-analytical nature, it possesses certain advantages over the conventional boundary element method. The exact solution for a single inclusion is derived using the present formulation and matches well with the Honein et al.’s solution by using the complex-variable formulation (Honein, E., Honein, T., and Hermann, G., 1992, Appl. Math., 50, pp. 479–499). Several problems of two holes, two inclusions, one cavity surrounded by two inclusions and three inclusions are revisited to demonstrate the validity of our method. The convergence test and boundary-layer effect are also addressed. The proposed formulation can be generalized to multiple circular inclusions and cavities in a straightforward way without any difficulty.
Combined Torsional-Bending-Axial Dynamics of a Twisted Rotating Cantilever Timoshenko Beam With Contact-Impact Loads at the Free End
Authors: Sinha Sunil K.
Published: May 2007

In this paper, consideration is given to the dynamic response of a rotating cantilever twisted and inclined airfoil blade subjected to contact loads at the free end. Starting with the basic geometrical relations and energy formulation for a rotating Timoshenko beam constrained at the hub in a centrifugal force field, a system of coupled partial differential equations are derived for the combined axial, lateral and twisting motions which includes the transverse shear, rotary inertia, and Coriolis effects, as well. In the mathematical formulation, the torsion of the thin airfoil also considers a very general case of shear center not being coincident with the CG (center of gravity) of the cross section, which allows the equations to be used also for analyzing eccentric tip-rub loading of the blade. Equations are presented in terms of axial load along the longitudinal direction of the beam which enables us to solve the dynamic pulse buckling due to the tip being loaded in the longitudinal as well as transverse directions of the beam column. The Rayleigh–Ritz method is used to convert the set of four coupled-partial differential equations into equivalent classical mass, stiffness, damping, and gyroscopic matrices. Natural frequencies are computed for beams with varying “slenderness ratio” and “aspect ratio” as well as “twist angles.” Dynamical equations account for the full coupling effect of the transverse flexural motion of the beam with the torsional and axial motions due to pretwist in the airfoil. Some transient dynamic responses of a rotating beam repeatedly rubbing against the outer casing is shown for a typical airfoil with and without a pretwist.
Development of a mathematical model of frazil ice evolution based on laboratory tests using a counter-rotating flume
Authors: Wang Shuang Ming , Doering J C
Published: May 2007

A mathematical model to simulate the supercooling process and frazil ice evolution in a counter-rotating flume was developed. It considers the effect of frazil ice thermal growth while neglecting several complicated physical processes such as secondary nucleation, flocculation, and (or) break up. The supercooling process, vertical distribution of flow turbulence parameters, and frazil ice number concentration were simulated, as well the variation of the mean size of frazil ice during the supercooling process was modeled. The simulation results from this model show good agreement with experimental data.Key words: frazil ice, turbulence, numerical models, counter-rotating flume, supercooling.
An optimal downsampling procedure for microscopic simulation modeling of transportation networks: a proof-of-concept study
Authors: Alecsandru Ciprian , Ishak Sherif , Zhang Yan
Published: May 2007

This paper investigates and demonstrates the concept of scalability of microscopic traffic simulation systems as a means of reducing the associated computational requirements and maximizing their potential support for real-time traffic control and management functions. The primary goal of this research is to examine the feasibility of transforming the original simulation environment into a downsampled simulation environment, where fewer representative entities are simulated. This must be achieved, however, while retaining maximum fidelity to microscopic simulation properties and preserving most of the macroscopic characteristics. The methodology is presented as an optimization problem whose objective is to minimize the errors resulting from the transformation process and to seek optimal values of the behavioral parameters in the downsampled environment. In this proof-of-concept stage, experimental analysis was conducted on a homogeneous freeway segment using one of the well-known, and arguably sufficiently calibrated, car-following models developed by General Motors Laboratories (GM3). The results were promising and showed that optimal relationships between the behavioral parameters in both environments can be established to minimize the information loss associated with the transformation process.Key words: microscopic simulation, scalability, computational efficiency, downsampling, car-following models.
Rapid assessment of the tracking resistance of bituminous crack sealants
Authors: Masson J-F , Collins P , Perraton D , Al-Qadi I
Published: May 2007

The bituminous sealants used in the preventive maintenance of pavements sometimes deform (track) under the action of passing vehicles. In summer, this is the prevalent mode of sealant failure. To assess the propensity of a sealant to deform in summer, a standard flow test is used, but the imprecision in the results has prevented any correlation with field performance. Two methods were evaluated in an attempt to find an alternative means of assessing deformation. The first method relied on the use of the French rut tester, and the second method relied on the use of a Taber abraser. The first method was found to be inappropriate to test sealants because of its severity, but the second method proved promising. The Taber abraser allowed for the measurement of sealant displacement at various temperatures and for distinguishing the deformation propensity of sealants.Key words: pavements, roadways, maintenance, sealants, sealing, specification, testing, performance.
Improvement of flammability resistance of epoxy adhesives used in infrastructure applications
Authors: Wu Lixin , Hoa Suong V , Wang Heng
Published: May 2007

Fire endurance of fibre-reinforced-polymer (FRP) concrete systems is crucial for safe use of FRPs in the construction industry. Nanoclay was introduced into epoxy resin to retard flame spread and improve the fire endurance of bonds between FRP and concrete. Test results show that the addition of nanoclay can greatly improve the flame retardancy of epoxy. With only 2% nanoclay, the limit oxygen index number of epoxy increases by 5 and 10 using two types of mixing methods developed at the Concordia Centre for Composites. The epoxy with the addition of nanoclay possesses self-extinguishing properties, whereas the epoxy without the addition of nanoclay burned completely. After exposure to 260 °C for 2 h, the FRP-concrete system using epoxy and 2% nanoclay adhesive showed 23% greater average residual bonding strength than that using control epoxy adhesive. The nanoclay used in this study is a nontoxic and inexpensive material that may fulfill the requirements for civil engineering applications.Key words: fire resistance, fibre-reinforced polymer, concrete, bond, adhesive, nanoclay, epoxy.
New Canadian Highway Bridge Design Code design provisions for fibre-reinforced structures
Authors: Mufti A A , Bakht B , Banthia N , Benmokrane B , Desgagné G , Eden R , Erki M -A , Karbhari V , Kroman J , Lai D , Machida A , Neale K , Tadros G , Täljsten B
Published: May 2007

This paper presents a synthesis of the design provisions of the second edition of the Canadian Highway Bridge Design Code (CHBDC) for fibre-reinforced structures. New design provisions for applications not covered by the first edition of the CHBDC and the rationale for those that remain unchanged from the first edition are given. Among the new design provisions are those for glass-fibre-reinforced polymer as both primary reinforcement and tendons in concrete; and for the rehabilitation of concrete and timber structures with externally bonded fibre-reinforced-polymer (FRP) systems or near-surface-mounted reinforcement. The provisions for fibre-reinforced concrete deck slabs in the first edition have been reorganized in the second edition to explicitly include deck slabs of both cast-in-place and precast construction and are now referred to as externally restrained deck slabs, whereas deck slabs containing internal FRP reinforcement are referred to as internally restrained deck slabs. Resistance factors in the second edition have been recast from those in the first edition and depend on the condition of use, with a further distinction made between factory- and field-produced FRP. In the second edition, the deformability requirements for FRP-reinforced and FRP-prestressed concrete beams and slabs of the first edition have been split into three subclauses covering the design for deformability, minimum flexural resistance, and crack-control reinforcement. The effect of sustained loads on the strength of FRPs is accounted for in the second edition by limits on stresses in FRP at the serviceability limit state.Key words: beams, bridges, concrete, decks, fibre-reinforced-polymer reinforcement, fibre-reinforced-polymer sheets, prestressing, repair, strengthening, wood.
Developing a structural-health-monitoring model to monitor cracking in steel-free concrete deck slabs
Authors: Yang Chaochao , Newhook John
Published: May 2007

The ISIS Canada Networks of Centres of Excellence (NCE) program has focused on two main themes to improve civil engineering infrastructure, namely innovative construction technologies, and structural health monitoring (SHM). The former began with the construction of the first field application of the innovative steel-free concrete bridge deck slab technology at the Salmon River bridge, Nova Scotia, in 1995. Although this bridge has continued to function safely under heavy traffic loads, it has developed characteristic longitudinal cracking of the concrete between adjacent girders due to fatigue. This paper describes the recent research to develop an SHM model for monitoring the impact and stability of this cracking. Theoretical and experimental models were used to examine the change in response as cracking develops. A global load distribution matrix was proposed, and the variation in load distribution values with cracking was used to develop a cracking index that can be employed in monitoring the field structure.Key words: structural health monitoring, bridges, concrete, deck slabs, cracking, load distribution.
First ISIS Canada pedestrian bridge: student design perspective
Authors: El-Hacha R , Bisby L , Williams B , Tung D , Ford J
Published: May 2007

In January 2002, the Intelligent Sensing for Innovative Structures (ISIS) Canada Networks of Centres of Excellence announced its first pedestrian bridge design competition for ISIS students. The bridge is located on the campus of the Université de Sherbrooke to provide a new access to the new east entrance of the Faculty of Engineering Building. The proposed design was required to convey the innovation and ingenuity of the ISIS Canada Research Network through the use of fibre-reinforced-polymer (FRP) materials. Based on these requirements, five graduate students from the Department of Civil Engineering at Queen's University joined forces to produce the winning conceptual design, demonstrating cost-effectiveness, visual stimulation, and innovation. This application paper presents details of the competition and the winning design for the pedestrian bridge as told by the winning design team. The bridge was built during the summer of 2002 at the Université de Sherbrooke. The objective of the paper is to present the student experience from this highly successful competition, and thus to promote similar design competitions for engineering students.Key words: short span, pedestrian bridge, fibre-reinforced polymers, reinforced concrete, conceptual design, innovation, ingenuity.
Civionics for structural health monitoring
Authors: Rivera E , Mufti A A , Thomson D J
Published: May 2007

As the design and construction of civil structures continue to evolve, it is becoming imperative that these structures be monitored for their health. To meet this need, the discipline of civionics has emerged. It involves the application of electronics to civil structures and aims to assist engineers in realizing the full benefits of structural health monitoring (SHM). Therefore, the goal of the civionics specifications outlined in this work is to ensure that the installation and operation of fibre optic sensors are successful. This paper will discuss several lessons learned during the implementation of health monitoring systems for civil structures. The monitoring of these structures primarily motivated the writing of these specifications. Creating a standard procedure for SHM eliminated several ambiguities, such as fibre sensor specifications and the types of cables required. As a result, it is expected that these specifications will help ensure that the sensors will survive the installation process and eventually prove their value over years of structural health monitoring. The civionics fibre optic sensor specifications include the requirements for fibre sensors and their corresponding readout units. They also include specifications for the cables, conduits, junction boxes, termination, and environmental protection.Key words: civionics, structural health monitoring, fibre optic sensors, specifications.
Comparison of transformation protocols in Streptococcus gordonii and evaluation of native promoter strength using a multiple-copy plasmid
Authors: Warren Travis K. , Lund S.  Amanda , Jones Kevin F. , Hruby Dennis E.
Published: May 2007

An active area of research in the development of Streptococcus gordonii for use as a bacterial commensal vector involves the identification and utilization of strong promoters for high-level expression of heterologous products. Escherichia coli plasmid vectors containing different streptococcal promoters often fail to become established in E. coli for unknown reasons. Therefore, it is desirable at times to transform S. gordonii, which is naturally competent, with small quantities of nascently ligated DNA without using E. coli first to amplify or screen the product. By comparing the efficiency of two methods used to induce competence in S. gordonii, it was shown that the use of a synthetic competence stimulating peptide substantially enhanced plasmid uptake by S. gordonii. We amplified the amylase-binding protein (abpA) promoter from the S. gordonii genome and, using a synthetic peptide to induce competence, directly introduced plasmid DNA containing this promoter into S. gordonii as an unamplified product of ligation. This plasmid facilitated abundant secretion of a heterologous product by S. gordonii. By assessing the levels of heterologous product secreted by two plasmid constructs, it was possible to evaluate the relative strength of two native promoters.
A FAMILY OF MARKED CUBIC SURFACES AND THE ROOT SYSTEM D5
Authors: COLOMBO ELISABETTA , VAN GEEMEN BERT
Published: May 2007

We define and study a family of cubic surfaces in the projectivized tangent bundle over a four-dimensional projective space associated to the root system D5. The 27 lines are rational over the base and we determine the classifying map to the moduli space of marked cubic surfaces. This map has degree two and we use it to get short proofs for some results on the Chow group of the moduli space of marked cubic surfaces.
A FAMILY OF SURFACES CONSTRUCTED FROM GENUS 2 CURVES
Authors: SCHOEN CHAD
Published: May 2007

We consider the deformations of the two-dimensional complex analytic variety constructed from a genus 2 Riemann surface by attaching its self-product to its Jacobian in an elementary way. The deformations are shown to be unobstructed, the variety smooths to give complex projective manifolds whose invariants are computed and whose images under Albanese maps (re)verify an instance of the Hodge conjecture for certain abelian fourfolds.
WREATH PRODUCTS, NILPOTENT ORBITS AND SYMPLECTIC DEFORMATIONS
Authors: FU BAOHUA
Published: May 2007

We recover the wreath product X ≔ Sym 2(ℂ2/± 1) as a transversal slice to a nilpotent orbit in 𝔰𝔭6. By using deformations of Springer resolutions, we construct a symplectic deformation of symplectic resolutions of X.
VECTOR BUNDLES, DUALITIES AND CLASSICAL GEOMETRY ON A CURVE OF GENUS TWO
Authors: NGUYEN QUANG MINH
Published: May 2007

Let C be a curve of genus two. We denote by [Formula: see text] the moduli space of semi-stable vector bundles of rank 3 and trivial determinant over C, and by Jd the variety of line bundles of degree d on C. In particular, J1 has a canonical theta divisor Θ. The space [Formula: see text] is a double cover of ℙ8 = |3Θ| branched along a sextic hypersurface, the Coble sextic. In the dual [Formula: see text], where J1 is embedded, there is a unique cubic hypersurface singular along J1, the Coble cubic. We prove that these two hypersurfaces are dual, inducing a non-abelian Torelli result. Moreover, by looking at some special linear sections of these hypersurfaces, we can observe and reinterpret some classical results of algebraic geometry in a context of vector bundles: the duality of the Segre–Igusa quartic with the Segre cubic, the symmetric configuration of 15 lines and 15 points, the Weddle quartic surface and the Kummer surface.
A DISCRETE MODEL OF EVOLUTION OF SMALL PARALOG FAMILIES
Authors: TIURYN JERZY , WÓJTOWICZ DAMIAN , RUDNICKI RYSZARD
Published: May 2007

We introduce and analyze a simple probabilistic model of genome evolution. It is based on three fundamental evolutionary events: gene loss, duplication and accumulated change. We are mainly interested in asymptotic size distribution of small paralogous gene families in a genome. This is motivated by previous works which consisted in fitting the available genomic data into, what is called, paralog distributions. This formalism is described as a discrete-time Markov chain. The formulas for equilibrium paralog family sizes are derived. Moreover, we show that when probabilities of gene removal and duplication are small and close to each other, then the resulting distribution is close to logarithmic distribution. Some empirical results for microbial genomes are presented.
Measurement of human mixed muscle protein fractional synthesis rate depends on the choice of amino acid tracer
Authors: Smith Gordon I. , Villareal Dennis T. , Mittendorfer Bettina
Published: May 2007

The goal of this study was to discover whether using different tracers affects the measured rate of muscle protein synthesis in human muscle. We therefore measured the mixed muscle protein fractional synthesis rate (FSR) in the quadriceps of older adults during basal, postabsorptive conditions and mixed meal feeding (70 mg protein·kg fat-free mass−1·h−1× 2.5 h) by simultaneous intravenous infusions of [5,5,5-2H3]leucine and either [ring-13C6]phenylalanine or [ring-2H5]phenylalanine and analysis of muscle tissue samples by gas chromatography-mass spectrometry. Both the basal FSR and the FSR during feeding were ∼20% greater ( P < 0.001) when calculated from the leucine labeling in muscle tissue fluid and proteins (fasted: 0.063 ± 0.005%/h; fed: 0.080 ± 0.007%/h) than when calculated from the phenylalanine enrichment data (0.051 ± 0.004 and 0.066 ± 0.005%/h, respectively). The feeding-induced increase in the FSR (∼20%; P = 0.011) was not different with leucine and phenylalanine tracers ( P = 0.69). Furthermore, the difference between the leucine- and phenylalanine-derived FSRs was independent of the phenylalanine isotopomer used ( P = 0.92). We conclude that when using stable isotope-labeled tracers and the classic precursor product model to measure the rate of muscle protein synthesis, absolute rates of muscle protein FSR differ significantly depending on the tracer amino acid used; however, the anabolic response to feeding is independent of the tracer used. Thus different precursor amino acid tracers cannot be used interchangeably for the evaluation of muscle protein synthesis, and data from studies using different tracer amino acids can be compared qualitatively but not quantitatively.
Hyperglycemia impairs glucose and insulin regulation of nitric oxide production in glucose-inhibited neurons in the ventromedial hypothalamus
Authors: Canabal Debra D. , Potian Joseph G. , Duran Ricardo G. , McArdle Joseph J. , Routh Vanessa H.
Published: May 2007

Physiological changes in extracellular glucose, insulin, and leptin regulate glucose-excited (GE) and glucose-inhibited (GI) neurons in the ventromedial hypothalamus (VMH). Nitric oxide (NO) signaling, which is involved in the regulation of food intake and insulin signaling, is altered in obesity and diabetes. We previously showed that glucose and leptin inhibit NO production via the AMP-activated protein kinase (AMPK) pathway, while insulin stimulates NO production via the phosphatidylinositol-3-OH kinase (PI3K) pathway in VMH GI neurons. Hyperglycemia-induced inhibition of AMPK reduces PI3K signaling by activating the mammalian target of rapamycin (mTOR). We hypothesize that hyperglycemia impairs glucose and insulin-regulated NO production in VMH GI neurons. This hypothesis was tested in VMH neurons cultured in hyperglycemic conditions or from streptozotocin-induced type 1 diabetic rats using NO- and membrane potential-sensitive dyes. Neither decreased extracellular glucose from 2.5 to 0.5 mM, nor 5 nM insulin increased NO production in VMH neurons in either experimental condition. Glucose- and insulin-regulated NO production was restored in the presence of the AMPK activator, 5-aminoimidazole-4-carboxamide-1-b-4-ribofuranoside or the mTOR inhibitor rapamycin. Finally, decreased glucose and insulin did not alter membrane potential in VMH neurons cultured in hyperglycemic conditions or from streptozotocin-induced rats. These data suggest that hyperglycemia impairs glucose and insulin regulation of NO production through AMPK inhibition. Furthermore, glucose and insulin signaling pathways interact via the mTOR pathway.
Fasting-induced changes in ECL cell gene expression
Authors: Lambrecht Nils W. G. , Yakubov Iskandar , Sachs George
Published: May 2007

Gastric enterochromaffin-like (ECL) cells release histamine in response to food because of elevation of gastrin and neural release of pituitary adenylate cyclase-activating peptide (PACAP). Acid secretion is at a basal level in the absence of food but is rapidly stimulated with feeding. Rats fasted for 24 h showed a significant decrease of mucosal histamine despite steady-state expression of the histamine-synthesizing enzyme histamine decarboxylase (HDC). Comparative transcriptomal analysis using gene expression oligonucleotide microarrays of 95% pure ECL cells from fed and 24-h fasted rats, thereby eliminating mRNA contamination from other gastric mucosal cell types, identified significantly increased gene expression of the enzymes histidase and urocanase catabolizing the HDC substrate l-histidine but significantly decreased expression of the cellular l-histidine uptake transporter SN2 and of the vesicular monoamine transporter 2 (VMAT-2) responsible for histamine uptake into secretory vesicles. This was confirmed by reverse transcriptase-quantitative polymerase chain reaction of gastric fundic mucosal samples from fed and 24-h fasted rats. The decrease of VMAT-2 gene expression was also shown by a decrease in VMAT-2 protein content in protein extracts from fed and 24-h fasted rats compared with equal amounts of HDC protein and Na-K-ATPase α1-subunit protein content. These results indicate that rat gastric ECL cells regulate their histamine content during 24-h fasting not by a change in HDC gene or protein expression but by regulation of substrate concentration for HDC and a decreased histamine secretory pool.
Functional Interactions during the Retrieval of Conceptual Action Knowledge: An fMRI Study
Authors: Assmus Ann , Giessing Carsten , Weiss Peter H. , Fink Gereon R.
Published: May 2007

Impaired retrieval of conceptual knowledge for actions has been associated with lesions of left premotor, left parietal, and left middle temporal areas [Tranel, D., Kemmerer, D., Adolphs, R., Damasio, H., & Damasio, A. R. Neural correlates of conceptual knowledge for actions. Cognitive Neuropsychology, 409–432, 2003]. Here we aimed at characterizing the differential contribution of these areas to the retrieval of conceptual knowledge about actions. During functional magnetic resonance imaging (fMRI), different categories of pictograms (whole-body actions, manipulable and nonmanipulable objects) were presented to healthy subjects. fMRI data were analyzed using SPM2. A conjunction analysis of the neural activations elicited by all pictograms revealed ( p < .05, corrected) a bilateral inferior occipito-temporal neural network with strong activations in the right and left fusiform gyri. Action pictograms contrasted to object pictograms showed differential activation of area MT+, the inferior and superior parietal cortex, and the premotor cortex bilaterally. An analysis of psychophysiological interactions identified contribution-dependent changes in the neural responses when pictograms triggered the retrieval of conceptual action knowledge: Processing of action pictograms specifically enhanced the neural interaction between the right and left fusiform gyri, the right and left middle temporal cortices (MT+), and the left superior and inferior parietal cortex. These results complement and extend previous neuropsychological and neuroimaging studies by showing that knowledge about action concepts results from an increased coupling between areas concerned with semantic processing (fusiform gyrus), movement perception (MT+), and temporospatial movement control (left parietal cortex).
Distinct Regions of the Medial Prefrontal Cortex Are Associated with Self-referential Processing and Perspective Taking
Authors: D'Argembeau Arnaud , Ruby Perrine , Collette Fabienne , Degueldre Christian , Balteau Evelyne , Luxen André , Maquet Pierre , Salmon Eric
Published: May 2007

The medial prefrontal cortex (MPFC) appears to play a prominent role in two fundamental aspects of social cognition, that is, self-referential processing and perspective taking. However, it is currently unclear whether the same or different regions of the MPFC mediate these two interdependent processes. This functional magnetic resonance imaging study sought to clarify the issue by manipulating both dimensions in a factorial design. Participants judged the extent to which trait adjectives described their own personality (e.g., “Are you sociable?”) or the personality of a close friend (e.g., “Is Caroline sociable?”) and were also asked to put themselves in the place of their friend (i.e., to take a third-person perspective) and estimate how this person would judge the adjectives, with the target of the judgments again being either the self (e.g., “According to Caroline, are you sociable?”) or the other person (e.g., “According to Caroline, is she sociable?”). We found that self-referential processing (i.e., judgments targeting the self vs. the other person) yielded activation in the ventral and dorsal anterior MPFC, whereas perspective taking (i.e., adopting the other person's perspective, rather than one's own, when making judgments) resulted in activation in the posterior dorsal MPFC; the interaction between the two dimensions yielded activation in the left dorsal MPFC. These findings show that self-referential processing and perspective taking recruit distinct regions of the MPFC and suggest that the left dorsal MPFC may be involved in decoupling one's own from other people's perspectives on the self.
Nasserism Revitalized. A Critical Reading of Hasan Hanafī's Projects "The Islamic Left" and "occidentalism" (and their Uncritical Reading)
Authors: Riexinger Martin
Published: May 2007

Hasan Hanafī is often described as leading and original reformer of Arab thought, renovator of the Islamic cultural heritage (turāth) and advocate of political freedom. But these categorizations are based on insufficient analyses of his writings on both the Islamic and the Western intellectual heritage as well as his statements on current political issues. A critical reading of the first unveils that Hanafī misrepresents religious and philosophical doctrines and that he systematically passes over the fact that the relations between intellectual currents which he claims as role models for the "Islamic left" were marked by deep enmity. His writings on Marxism reveal that he merely condemns capitalism on moral terms without deeper analysis of the way it works. He himself proposes the idea of historical cycles determining the course of Eastern and Western civilization. This allows him to predict the imminent decline of the latter. The contradicting elements in Hanafī's thought do, however, gain coherence when analyzed in the context of his writings on the modern history of Egypt and the Middle East at large. Here he juxtaposes activist and progressive Nasserism to the religious quietism used by Sadat to legitimize his rule. From 1978 onwards he became an advocate of the Islamic revolution in Iran which he saw as rebirth of Nasserim and Tiermondism in general.
Temperature Anomalies in the Northeastern North Atlantic: Subpolar and Subtropical Precursors on Multiannual Time Scales
Authors: Junge Martina M. , Fraedrich Klaus
Published: May 2007

An adjoint ocean general circulation model of the North Atlantic is employed to calculate sensitivities of temperature in the northeastern North Atlantic with respect to atmospheric nonlocal fluxes and ocean state variables at prior times, up to 7 yr.

Maximum sensitivities cross the Atlantic from east to west within 3 to 4 yr. On this interannual time scale, advection of temperature perturbations by the climatological flow is suggested as the prime mechanism responsible for SST perturbations in the northeastern North Atlantic. The pathway of sensitivities lies preferentially beneath the surface and can be understood in terms of the reemergence mechanism. This provides the link between local forcing, mainly by heat flux in winter, and resurfacing of perturbations at remote locations.

On the multiannual to decadal time scale, the western subpolar gyre plays a key role: negative temperature sensitivities that evolve in parallel with positive salinity sensitivities in the Labrador and Irminger Seas give rise to pressure gradients and velocity perturbations that have effects on SST by modifying the oceanic heat transport into the northeastern North Atlantic. Together with additional influence from the Tropics and the subtropical gyre on time scales of 5 yr and beyond, these sensitivities combine to make a plethora of time scales that play a role in shaping SST perturbations in the North Atlantic.
El Niño in a Coupled Climate Model: Sensitivity to Changes in Mean State Induced by Heat Flux and Wind Stress Corrections
Authors: Spencer Hilary , Sutton Rowan , Slingo Julia M.
Published: May 2007

Here the factors affecting the mean state and El Niño variability in the Third Hadley Centre Coupled Ocean–Atmosphere General Circulation Model (HadCM3) are examined with and without heat flux or wind stress corrections. There is currently little confidence in the prediction of El Niño for seasonal forecasts or climate change due to the inaccuracies in coupled models. If heat flux or wind stress corrections could reduce these biases then forecasts might be improved.

Heat flux corrections have unexpected effects on both the mean state and variability of HadCM3. HadCM3 is found to be very sensitive to the corrections imposed. If heat flux corrections are imposed Tropics wide then easterlies in the eastern equatorial Pacific are increased leading to localized steep east–west gradients in the thermocline or “thermocline jumps,” which appear to suppress propagation of heat from the west to the east and hence suppress strong El Niños so that ENSO variability is weak. In contrast, if heat flux corrections are imposed only within 10° of the equator, an atmospheric teleconnection from the cold subtropical SST biases intensifies the ITCZ and weakens the equatorial easterlies. As a result, the thermocline jumps are flattened and strong El Niños occur very frequently. Neither heat flux correction procedure improves the representation of El Niño.

Wind stress corrections alone have a small impact on the coupled model. Some of the SST warm biases are reduced, but the variability is not altered significantly.